WO2012081569A1 - Light emitting element, light adjusting element, display device, and lighting device - Google Patents

Light emitting element, light adjusting element, display device, and lighting device Download PDF

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Publication number
WO2012081569A1
WO2012081569A1 PCT/JP2011/078765 JP2011078765W WO2012081569A1 WO 2012081569 A1 WO2012081569 A1 WO 2012081569A1 JP 2011078765 W JP2011078765 W JP 2011078765W WO 2012081569 A1 WO2012081569 A1 WO 2012081569A1
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WIPO (PCT)
Prior art keywords
light
emitting element
light emitting
concave mirror
emitted
Prior art date
Application number
PCT/JP2011/078765
Other languages
French (fr)
Japanese (ja)
Inventor
梅中　靖之
豪 鎌田
柴田　諭
昇平 勝田
大祐 篠崎
Original Assignee
シャープ株式会社
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Publication of WO2012081569A1 publication Critical patent/WO2012081569A1/en

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    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/0001—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems
    • G02B6/0011—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems the light guides being planar or of plate-like form
    • G02B6/0033—Means for improving the coupling-out of light from the light guide
    • G02B6/0058—Means for improving the coupling-out of light from the light guide varying in density, size, shape or depth along the light guide
    • G02B6/006—Means for improving the coupling-out of light from the light guide varying in density, size, shape or depth along the light guide to produce indicia, symbols, texts or the like
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/0001—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems
    • G02B6/0011—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems the light guides being planar or of plate-like form
    • G02B6/0013—Means for improving the coupling-in of light from the light source into the light guide
    • G02B6/0023—Means for improving the coupling-in of light from the light source into the light guide provided by one optical element, or plurality thereof, placed between the light guide and the light source, or around the light source
    • G02B6/0031—Reflecting element, sheet or layer
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/0001—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems
    • G02B6/0011—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems the light guides being planar or of plate-like form
    • G02B6/0033—Means for improving the coupling-out of light from the light guide
    • G02B6/0035—Means for improving the coupling-out of light from the light guide provided on the surface of the light guide or in the bulk of it
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L33/00—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L33/48—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the semiconductor body packages
    • H01L33/58—Optical field-shaping elements

Definitions

  • the present invention relates to a light emitting element, a light control element, a display device, and a lighting device.
  • This application claims priority based on Japanese Patent Application No. 2010-280263 filed in Japan on December 16, 2010, the contents of which are incorporated herein by reference.
  • a light emitting element having a light source such as a light emitting diode (hereinafter abbreviated as LED) is known.
  • a light-emitting element having a configuration of a reflective light-emitting diode that includes a light source mounted on a substrate and has a reflective surface that reflects light emitted from the light source and reflects it to the outside is disclosed. (See Patent Document 1 below). This light emitting element extracts light from the normal direction of the LED mounting substrate.
  • a light emitting element having a light source mounted on a substrate and an orientation control member having a plurality of incident surfaces and reflecting surfaces is disclosed (the following patent document) 2). This light emitting element extracts light from a direction different from the normal direction of the LED mounting substrate.
  • Patent Document 1 can extract light having directivity, it cannot extract light obliquely with respect to the normal line of the LED mounting substrate.
  • a light emitting element is attached to one surface of an object (for example, a surface to which the light emitting element is attached, such as an end face of a light guide plate)
  • light cannot be extracted in an oblique direction with respect to the normal of the one surface of the object.
  • the technique of Patent Document 2 cannot extract light having directivity. Therefore, the light-emitting element can be applied to an application such as a lighting device that hardly requires light having high directivity, but cannot be applied to a device that requires light having high directivity.
  • An aspect of the present invention is made to solve the above-described problem, and provides a light-emitting element capable of extracting light with high directivity in an oblique direction with respect to a normal line of one surface of an object.
  • Another object is to provide a light control element that can obtain a sufficient amount of light by using the light emitting element.
  • Another object is to provide a display device that can display brightly and with high contrast by using the above light control element.
  • a light-emitting element includes a mounting surface for mounting on a light guide, and the light-emitting element includes a package in which a recess is formed, and the recess in the package. And a light source disposed at the focal point of the concave mirror, and a straight line connecting the central point of the concave mirror and the focal point obliquely intersects the normal of the mounting surface Yes.
  • the straight line may coincide with a normal line of a light emission surface of the light source.
  • the concave mirror may be a parabolic mirror, and the straight line may coincide with a rotational symmetry axis of the parabolic mirror.
  • the light-emitting element further includes a reflection mirror, and the reflection mirror is disposed such that the light source is disposed between the concave mirror and the reflection mirror, and the reflection mirror is the concave surface. Light from the light source emitted in a direction different from the mirror may be reflected toward the concave mirror.
  • the light-emitting element further includes a light transmissive member that transmits light emitted from the light source, and the light source is embedded in the concave portion of the package by the light transmissive member,
  • the light transmission member may form the mounting surface.
  • the light-emitting element according to one embodiment of the present invention may further include a lid member, the lid member may form the attachment surface, and the lid member may be disposed so as to close the recess.
  • the light source may be attached to the back surface of the lid member.
  • the light control device includes an illumination unit capable of controlling the amount of emitted light, and a light guide that receives the light emitted from the illumination unit and propagates the light while totally reflecting the light inside.
  • the light guide has a plurality of light extraction regions for extracting the light to the outside while the light emitted from the illumination unit is propagated while being totally reflected inside the light guide, At least two light extraction regions of the plurality of light extraction regions have different incident angle ranges in which light emitted from the illumination unit can be extracted to the outside, and the light guide is emitted from the illumination unit
  • the light is configured to propagate inside the light guide at a plurality of different propagation angles
  • the illumination unit includes a light emitting element having an attachment surface for attaching to the light guide, and the light emitting element includes a recess.
  • a package formed with the package A concave mirror provided in the concave portion and a light source disposed at the focal point of the concave mirror, and a straight line connecting the center point of the concave mirror and the focal point obliquely intersects with the normal of the mounting surface is doing.
  • the end surface of the light guide is orthogonal to the surface on which the light extraction region is provided, and the light emitting device is disposed on the end surface of the light guide.
  • a plurality of light emitting elements are arranged, and each of the plurality of light emitting elements has the straight line in a different direction with respect to the light extraction region so that the emitted light is incident on the light extraction region at different incident angles. It may be arranged so that.
  • a display device includes the above-described dimming element and a display element that performs display using light emitted from the dimming element.
  • a lighting device includes the above-described dimming element.
  • a light emitting element capable of extracting light with high directivity in an oblique direction with respect to the normal line of one surface of an object.
  • a light control element that can obtain a sufficient amount of light by using the light emitting element.
  • a bright display device with high contrast can be realized by using the dimmer element.
  • FIG. 13B is a cross-sectional view taken along the line A-A ′ of FIG. 13A showing an example of a lighting device.
  • FIG. 1 is a perspective view showing a liquid crystal display device and a backlight according to the present embodiment.
  • 2A to 2C are diagrams for explaining the principle of light emitted from each light extraction region in the backlight according to the present embodiment.
  • FIG. 2A shows a case where light is emitted from the first light extraction area RA.
  • FIG. 2B shows a case where light is emitted from the second light extraction region RB.
  • FIG. 2C shows a case where light is emitted from the third light extraction region RC.
  • FIG 3 is a cross-sectional view showing the light emitting device of this embodiment.
  • 4A to 4C are cross-sectional views showing the light-emitting elements of this embodiment.
  • FIGS. 5A to 5C are simulation results showing the relationship between the angle and the amount of emitted light in each light-emitting element of this embodiment.
  • the scale of the size may be varied depending on the component.
  • the liquid crystal display device 1 (display device) of the present embodiment includes a liquid crystal panel 2 (display element), a backlight 3 (light control element) disposed on the back side of the liquid crystal panel 2, have.
  • the liquid crystal panel 2 is a transmissive liquid crystal panel that performs display using light emitted from the backlight 3. The user can view the display from the opposite side of the backlight 3, that is, from the upper side of the liquid crystal panel 2 in FIG.
  • the configuration of the liquid crystal panel 2 is not particularly limited, and may be an active matrix liquid crystal panel including a switching thin film transistor (hereinafter abbreviated as TFT) for each pixel.
  • TFT switching thin film transistor
  • a simple matrix type liquid crystal panel that does not include a TFT may be used.
  • the liquid crystal panel is not limited to a transmissive liquid crystal panel, and may be a transflective liquid crystal panel.
  • the display mode is not particularly limited, and there are various display modes such as VA (Vertical Alignment) mode, TN (Twisted Nematic) mode, STN (Super Twisted Nematic) mode, IPS (In-Plane Switching) mode, etc.
  • VA Vertical Alignment
  • TN Transmission Nematic
  • STN Super Twisted Nematic
  • IPS In-Plane Switching
  • the backlight 3 of the present embodiment does not emit light uniformly from the entire surface of the light guide, which will be described later, but emits light for each light extraction region in which the entire surface is divided into a plurality (9 in this embodiment).
  • the amount of light emitted can be controlled. That is, in the backlight 3 of the present embodiment, each of the plurality of light extraction regions has a dimming function. As a whole of the backlight 3, it is possible to emit light only in a specific light extraction region or not. Alternatively, the amount of light emitted from a specific light extraction region can be changed with respect to the amount of light emitted from another light extraction region.
  • the backlight 3 includes light emitting elements 7a, 7b, and 7c.
  • light emitting elements 7a, 7b, and 7c are light emitting elements 7a, 7b, and 7c.
  • FIG. 3 is a cross-sectional view showing the light emitting element.
  • FIG. 3 shows a basic configuration (light emitting element 7) of three light emitting elements 7a, 7b, 7c provided on the first end face 5c.
  • the light emitting element 7 includes a package 71, a concave mirror 72, a light source 73, a reflection mirror 74, and a light transmission member 75, as shown in FIG.
  • the concave mirror 72 is provided in the concave portion 71 a of the package 71.
  • the shape of the concave mirror 72 is a curved shape that follows the shape of the concave portion 71 a of the package 71.
  • the concave mirror 72 is a parabolic mirror that reflects the light emitted from the light source 73.
  • the light source 73 is embedded in the recess 71 a of the package 71 by a light transmitting member 75 that transmits light emitted from the light source 73.
  • symbol Pf is the focal point of the concave mirror 72
  • symbol Pc is the central point of the concave mirror 72
  • symbol CL1 is the central axis of the concave mirror 72 (the central point Pc of the concave mirror 72 and the focal point Pf of the concave mirror 72).
  • the line CL) is a normal line of the mounting surface 71 b
  • the sign ⁇ is an inclination angle of the concave mirror 72.
  • the inclination angle of the concave mirror 72 is an angle formed by the central axis of the concave mirror 72 and the normal line of the mounting surface 71b.
  • a recess 71 a is formed in the package 71.
  • the package 71 has a rectangular parallelepiped shape, and has a mounting surface 71b on the side from which light is emitted (at the end of the portion where the recess 71a is formed).
  • the attachment surface 71 b is a flat surface that serves as an attachment surface when the light emitting element 7 is attached to the first end surface 5 c of the light guide 5.
  • the shape of the concave portion 71a of the package 71 is a curved shape that is concave with respect to the light source 73 when viewed from the normal surface of the virtual surface including the central axis CL1 of the concave mirror 72 and the normal line CL2 of the mounting surface 71b. Yes. That is, the slope of the tangent line of the curve gradually becomes gentler as it approaches the center point of the recess 71a.
  • the shape of the recess 71a of the package 71 is formed by a method such as resin injection molding using a mold having a convex shape obtained by inverting the shape of the recess 71a. Or you may form the shape of the recessed part 71a of the package 71 by cutting the surface of the originally flat resin member, for example.
  • the central axis CL1 of the concave mirror 72 obliquely intersects the normal line CL2 of the mounting surface 71b with a predetermined angle (inclination angle) ⁇ . Further, the central axis CL1 of the concave mirror 72 coincides with the rotation target axis of the parabolic mirror.
  • the size of the parabolic mirror (the diameter of a circle viewed from a direction parallel to the central axis CL1) is set to a diameter of 8 mm.
  • the radius of curvature of the parabolic mirror is set to 5.4 mm.
  • the concave mirror 72 is a parabolic mirror
  • it is not limited to this, and may be a spherical mirror, for example.
  • the concave mirror 72 is not limited to a circular rotationally symmetric shape as viewed from a direction parallel to the central axis CL1 of the concave mirror 72, and is parallel to the central axis CL1 of the concave mirror 72 such as an elliptical mirror. It is also possible to select a non-rotationally symmetric shape that is non-circular when viewed from the direction.
  • the light source 73 is a substantially rectangular parallelepiped chip LED (surface mounting LED).
  • the central axis CL1 of the concave mirror 72 coincides with the normal line of the light emission surface of the light source 73 (the normal line of the upper surface of the chip LED).
  • a reflection mirror 74 is provided on the side of the light source 73 opposite to the side where the concave mirror 72 is disposed. That is, the light source 73 is disposed between the concave mirror 72 and the reflection mirror 74.
  • the reflection mirror 74 can be formed on the mounting substrate of the light source 73 by, for example, forming a metal film such as aluminum by sputtering or vapor deposition.
  • the reflection mirror 74 reflects light from the light source 73 emitted in a different direction from the concave mirror 72 toward the concave mirror 72.
  • the size of the chip LED one side of a square viewed from a direction parallel to the central axis CL1
  • the size of the reflecting mirror is set to 1 mm.
  • a part of the reflection mirror 74 is provided with a printed wiring board on which the light source 73 is mounted.
  • a portion corresponding to the back surface of the light source 73 can be a mounting region, and the other portion (a peripheral portion of the mounting region) can be a reflection region.
  • Various wirings formed in the mounting region of the reflection mirror 74 include a printed wiring board on which the light emitting elements 7a, 7b, and 7c described above are mounted, and a control including a driving IC that is responsible for driving and controlling the light emitting elements 7a, 7b, and 7c. It is electrically connected to the part.
  • the light source 73 is embedded in the recess 71 a of the package 71 with a light transmitting member 75.
  • the light transmissive member 75 can be formed by the following method.
  • a concave mirror 72 is disposed in the recess 71 a of the package 71, and a light source 73 and a reflection mirror 74 are disposed inside the package 71.
  • a resin having optical transparency such as an acrylic resin is injected into the package 71 and cured.
  • the refractive index of the light transmitting member 75 is set to 1.5, which is the same value as the refractive index nWG (1.5) of the light guide 5.
  • the transmittance can be set to a value different from the refractive index nWG (1.5) of the light guide 5.
  • the transmittance of the light transmissive member 75 can be changed by selecting a material having a different refractive index when the light transmissive member 75 is formed, or by adding a low refractive index material to the resin material. This can be done by changing the concentration of the low refractive index material.
  • the backlight 3 is composed of three backlight units 4 having substantially the same dimensions, shape, and configuration.
  • the three backlight units 4 are in a direction orthogonal to the longitudinal direction of the light guide 5 described later, that is, a direction orthogonal to the direction in which the three light extraction regions RA, RB, RC of the light guide 5 are arranged (FIG. 1). In the y-axis direction). Therefore, the backlight 3 has a total of nine light extraction regions RA, RB, RC, three in each of the horizontal and vertical directions on the screen of the liquid crystal display device 1.
  • Each backlight unit 4 includes an illumination unit 6 and a light guide 5.
  • the illumination unit 6 includes a plurality (three in the present embodiment) of light emitting elements 7a, 7b, and 7c.
  • the light guide 5 is composed of a parallel plate made of a resin having optical transparency such as acrylic resin.
  • the backlight 3 shows the example comprised from the three backlight units 4 by which the light guide was made into the different body here, it has a total of nine light extraction area
  • the light guide may have an integral structure. Even with this structure, it is possible to select the light extraction regions RA, RB, and RC for emitting light by using a light emitting element with high directivity.
  • Three light emitting elements 7a, 7b, 7c are installed on one end face of the light guide 5 with the light emission side facing the light guide 5 side.
  • the light guide 5 receives light emitted from the light emitting elements 7a, 7b, and 7c.
  • the light guide 5 reflects the incident light from the inside to the opposite end surface (from the ⁇ x direction to the + x direction in FIG. 1) from the end surface side where the light emitting elements 7a, 7b, 7c are installed. It has the function of propagating and taking it out to the outside space.
  • the three light emitting elements 7a, 7b, and 7c can be individually controlled to be turned on / off, and the amount of emitted light can be controlled.
  • the backlight 3 includes a printed wiring board on which the light emitting elements 7a, 7b, and 7c are mounted, and a driving IC that is responsible for driving and controlling the light emitting elements 7a, 7b, and 7c.
  • a control unit and the like are provided.
  • the light emitting elements 7a, 7b, and 7c light emitting elements having a half value width of about 5 ° with respect to the spread angle of the emitted light while the light is guided through the light guide 5 can be used.
  • each light extraction region RA, RB, RC low refractive index bodies 8a, 8b, a refractive index body 9, and a light scattering body 10 are stacked in this order.
  • the low refractive index bodies 8 a and 8 b have a refractive index lower than that of the light guide 5.
  • the refractive index body 9 has a refractive index equal to the refractive index of the light guide 5.
  • the light scatterer 10 scatters the light emitted from the low refractive index bodies 8 a and 8 b and the refractive index body 9.
  • the respective light extraction regions are directed from the side closer to the light emitting elements 7a, 7b, 7c to the side farther from the first light extraction region RA, the second light extraction region RB, and the third light extraction. This is referred to as region RC.
  • the main surface of the light guide 5 provided with the light extraction regions RA, RB, RC is the first main surface 5a
  • the main surface opposite to the first main surface 5a is the second main surface 5b
  • the light emitting element 7a is the first end surface 5c
  • the end surface of the light guide 5 provided with 7b and 7c is referred to as a first end surface 5c
  • the end surface opposite to the first end surface 5c is referred to as a second end surface 5d.
  • the low refractive index bodies 8 a and 8 b both have a refractive index lower than that of the light guide 5, and the refractive index body 9 has a refractive index equal to the refractive index of the light guide 5.
  • the low refractive index bodies 8a and 8b and the refractive index body 9 have different refractive indexes.
  • the low refractive index bodies 8a and 8b and the refractive index body 9 are arranged along the propagation direction of light emitted from the light emitting elements 7a, 7b and 7c and incident on the light extraction regions RA, RB and RC (FIG.
  • the refractive index is relatively low, and the refractive index is relatively high.
  • the refractive index nWG of the light guide 5 is 1.5
  • the refractive index nA of the first low refractive index body 8a provided in the first light extraction region RA is 1.3
  • the refractive index nB of the second low refractive index body 8b provided in the second light extraction region RB is 1.4
  • the refractive index nC of the refractive index body 9 provided in the third light extraction region RC is 1.5. Is set.
  • the first method is to form the low refractive index bodies 8a and 8b and the refractive index body 9 using different materials.
  • an acrylic resin is used as the material of the light guide 5
  • Kuraray Co., Ltd. the material of the refractive index body 9.
  • the light scatterer 10 may be merely disposed on the light guide 5.
  • the second technique is to use a material containing a low refractive index material in a predetermined substrate and adjust the refractive index by varying the concentration of the low refractive index material.
  • Low refractive index materials such as powder (registered trademark, refractive index: 1.27) or airgel (registered trademark, refractive index: 1.27) manufactured by Jason Wells are included, and the concentration of these low refractive index materials is different.
  • Two types of liquids are prepared. Each liquid material can be selectively applied on the light guide 5 and cured.
  • a light scatterer 10 is laminated on the low refractive index bodies 8 a and 8 b and the refractive index body 9.
  • the light scatterer 10 has a function of scattering the light incident from the low refractive index bodies 8 a and 8 b and the refractive index body 9 and extracting the light to the external space of the backlight 3.
  • the light scatterer 10 a commercially available light scattering film in which scattering beads or the like are coated on a base film can be used.
  • the light scattering body 10 can be formed by sticking a light scattering film on the low refractive index bodies 8 a and 8 b and the refractive index body 9.
  • the first end surface 5 c of the light guide 5 is a right-angle surface having the same angle with respect to the first main surface 5 a.
  • Light emitting elements 7a, 7b, 7c are fixed to the first end surface 5c of the light guide 5 via an optical adhesive. Therefore, three light emitting elements 7 a, 7 b, 7 c are arranged in the short direction of the light guide 5 over the entire first end face 5 c.
  • the concave mirror 72 With such a configuration, most of the light emitted from the light source 73 is directly incident on the concave mirror 72.
  • light from the light source 73 emitted in a different direction from the remaining concave mirror 72 is reflected by the reflection mirror 74 and enters the concave mirror 72.
  • the light incident on the concave mirror 72 is reflected by the concave mirror 72 toward the mounting surface 71b. Since the light source 73 is disposed at the focal point Pc of the concave mirror 72, the light reflected by the concave mirror 72 is collimated.
  • the light collimated by the concave mirror 72 propagates through the light transmitting member 75 and is extracted from the mounting surface 71b.
  • the light emission surface of the light transmitting member 75 is the mounting surface.
  • the angle formed by the central axis CL1 of the concave mirror 72 and the normal line CL2 of the mounting surface 71b is the largest.
  • FIG. 2A is a sectional view taken along the line A-A ′ of FIG.
  • FIG. 2B shows a cross-sectional view along the line B-B ′ of FIG. 1.
  • FIG. 2C shows a cross-sectional view taken along the line C-C 'of FIG.
  • Each light emitting element 7a, 7b, 7c is fixed so that the light La, Lb, Lc is incident on the first end face 5c obliquely.
  • the light La, Lb, Lc emitted from each light emitting element 7a, 7b, 7c repeats total reflection between the first main surface 5a and the second main surface 5b of the light guide 5, and the first end surface 5c. Is propagated from the side toward the second end face 5d.
  • an angle formed by the optical axis with respect to a virtual horizontal plane passing through the center in the thickness direction of the light guide plate is defined as a propagation angle ⁇ .
  • the refractive index of the light transmission member 75 is set to 1.5, which is the same value as the refractive index nWG (1.5) of the light guide 5, the propagation angle ⁇ is equal to the inclination angle ⁇ . Therefore, as shown in FIG. 2A, the propagation angle phi A of the light La from the first light emitting element 7a becomes 37 °. As shown in Figure 2B, propagation angle phi B light Lb from the second light emitting element 7b becomes 26 °. As shown in FIG.
  • propagation angle phi C of the light Lc from the third light-emitting element 7c becomes 15 °. Therefore, while each light La, Lb, Lc is propagated from the first end face 5c side toward the second end face 5d side, the first light extraction area RA, the second light extraction area RB, and the third light extraction area RC. In this order, the light enters the light extraction areas RA, RB, RC.
  • the thickness (dimension in the z-axis direction) is drawn sufficiently larger than the longitudinal dimension (dimension in the x-axis direction) of the light guide 5 for easy viewing. Further, only the central axis of the light emitted from each light emitting element 7a, 7b, 7c is drawn. For this reason, it may seem that the light does not necessarily enter each of the light extraction regions RA, RB, RC, but actually the thickness is sufficiently small with respect to the longitudinal dimension of the light guide 5 and each light emitting element 7a. , 7b, 7c have a finite beam diameter, so that the light La, Lb, Lc is reliably incident on each of the light extraction areas RA, RB, RC.
  • the illuminating unit 6 of the present embodiment includes three light emitting elements 7a, 7b, and 7c.
  • Lights La, Lb, and Lc from the light emitting elements 7a, 7b, and 7c are converted into the light extraction regions RA,
  • Lights La, Lb, and Lc are extracted from RB and RC and are incident on the light extraction regions RA, RB, and RC at an incident angle including an incident angle at which the light can be extracted.
  • C 15 °).
  • the light La, Lb, and Lc from each light emitting element 7a, 7b, and 7c are the light guide 5 in each light extraction area
  • region RA, RB, RC, each low refractive index body 8a, 8b, and the refractive index body 9 Consider the critical angle when entering the interface.
  • the incident angle range in which light can be extracted outside in the first light extraction area RA is 60. Less than 1 °, the incident angle range in which light can be extracted outside in the second light extraction region RB is less than 69.0 °, and the incident angle range in which light can be extracted outside in the third light extraction region RC is all angles. It becomes a range.
  • the two low refractive index bodies 8a and 8b and the refractive index body 9 provided in the three light extraction regions RA, RB, and RC of the present embodiment are incident on the light extraction regions RA, RB, and RC.
  • the light is arranged in the order of relatively low refractive index to relatively high refractive index.
  • the three light extraction regions RA, RB, and RC have different incident angle ranges in which light can be extracted to the outside.
  • the three light extraction areas RA, RB, and RC have a relatively narrow incident angle range that can be extracted from a light extraction area that has a relatively narrow incident angle range along the propagation direction of incident light.
  • the incident angle range that can be extracted in the first light extraction region RA is less than 60.1 °
  • the incident angle range that can be extracted in the second light extraction region RB is less than 69.0 °
  • the incident angle range that can be extracted in the third light extraction region RC is the entire angle range.
  • the incident angle ⁇ A of the light La from the first light emitting element 7a with respect to the first major surface 5a is 53 °.
  • the incident angle ⁇ A with respect to the first major surface 5a is no matter how many times the light La from the first light emitting element 7a repeats total reflection. Always 53 °.
  • the critical angle ⁇ A 60.1 °
  • the light Lb cannot be transmitted through the interface between the light guide 5 and the first low refractive index body 8a, and is totally reflected.
  • the critical angle ⁇ B here is 69.0 °
  • the light Lb passes through the interface between the light guide 5 and the second low refractive index body 8b and is incident on the second low refractive index body 8b. , Extracted from the light scatterer 10 to the outside. In this way, substantially the entire amount of the light Lb emitted from the second light emitting element 7b can be extracted from the second light extraction region RB.
  • the backlight 3 of the present embodiment can extract light emitted from a predetermined LED only from a predetermined light extraction area.
  • the light Lc from the third light emitting element 7c is the first light Lc.
  • the light Lc from the third light emitting element 7c reaches the first light extraction region RA or the second light extraction region RB, and the interface between the light guide 5 and the first low refractive index body 8a or the second low refractive index body 8b.
  • incident angle ⁇ C 75 °
  • the incident angle ⁇ C is larger than the critical angle ⁇ A and the critical angle ⁇ B , so that the light Lc cannot be transmitted through each interface and is totally reflected.
  • the light Lc from the third light emitting element 7c reaches the third light extraction region RC, the light Lc passes through the interface between the light guide 5 and the refractive index body 9 and is incident on the refractive index body 9, and thereafter , Extracted from the light scatterer 10 to the outside. In this way, substantially the entire amount of the light Lc emitted from the third light emitting element 7c can be extracted from the third light extraction region RC.
  • the three light extraction areas RA are determined depending on which of the three light emitting elements 7a, 7b, and 7c of the backlight unit 4 is lit. , RB, and RC, the light extraction area from which light is extracted, that is, which light extraction area RA, RB, RC is allowed to emit light can be appropriately selected. Further, by controlling the amount of light emitted from each light emitting element 7a, 7b, 7c, the amount of light extracted from the selected light extraction regions RA, RB, RC, that is, the brightness of the selected light extraction region. Can be adjusted.
  • the light emitting element 7a of the present embodiment since the light source 73 is disposed at the focal point Pf of the concave mirror 72, the light emitted from the light source 73 and reflected by the concave mirror 72 is collimated. The light collimated by the concave mirror 72 is emitted from the mounting surface 71 b of the package 71. Therefore, light with high directivity can be extracted from the mounting surface 71 b of the package 71.
  • the light cannot be extracted in an oblique direction with respect to the normal line of the LED mounting substrate.
  • a light-emitting element is attached to one surface of an object (for example, a surface on which a light-emitting element is attached, such as an end face of a light guide plate)
  • light cannot be extracted in an oblique direction with respect to the normal of the one surface of the object .
  • the light emitting element 7a of the present embodiment since the central axis CL1 of the concave mirror 72 obliquely intersects the normal line CL2 of the mounting surface 71b of the package 71, the light is normal to one surface of the object.
  • the light emitting element 7a of the present embodiment can be taken out obliquely. Therefore, according to the light emitting element 7a of the present embodiment, light with high directivity can be extracted in an oblique direction with respect to the normal line of one surface of the object. In addition, in order to extract light in an oblique direction with respect to the normal of one surface of the object, it is not necessary to cut one surface of the object obliquely. Therefore, the shape of the object becomes simple, and processing is not time-consuming.
  • the central axis CL1 of the concave mirror 72 coincides with the normal line of the light exit surface of the light source 73. Therefore, the light emitted from the light source 73 can be extracted more efficiently than when the central axis CL1 of the concave mirror 72 is deviated from the normal line of the light emission surface of the light source 73.
  • the concave mirror 72 is a parabolic mirror and the light source 73 is disposed at the focal point Pf of the concave mirror 72, the light emitted from the light source 73 can be sufficiently collimated and extracted. Therefore, it becomes easy to extract light with high directivity.
  • a reflection mirror 74 is provided on the side opposite to the side where the concave mirror 72 of the light source 73 is disposed. Therefore, light reflected from the side opposite to the side where the concave mirror 72 of the light source 73 is disposed (light from the light source 73 not directly incident on the concave mirror 72) is reflected toward the concave mirror 72 by the reflection mirror 74.
  • the reflection mirror 74 is not provided, the light emitted from the side opposite to the side where the concave mirror 72 of the light source 73 is disposed is not reflected by the concave mirror 72, and the package 71 The light that has not been collimated is extracted as it is from the mounting surface 71b. Therefore, by providing the reflecting mirror 74, light with high directivity can be reliably extracted.
  • the position and posture of the light source 73 can be stably held. For example, when the light emitting element 7a receives an impact from the outside, the position of the light source 73 is shifted or the posture of the light source 73 is inclined (the light source 73 is shifted from the focal point Pf, or the normal line of the light emission surface of the light source 73). Can be prevented from deviating from the central axis CL1 of the concave mirror 72).
  • the configuration in which the reflection mirror 74 is provided on the side opposite to the side where the concave mirror 72 of the light source 73 is disposed is described as an example.
  • the configuration is not limited thereto.
  • the light from the light source emitted in a direction different from the concave mirror is directed in the same direction as the traveling direction of the light collimated by the concave mirror.
  • a collimating lens may be provided.
  • the light emitted from the side opposite to the side where the concave mirror of the light source is disposed (the light from the light source not directly incident on the concave mirror) is collimated by the collimating lens, and the mounting surface of the package
  • the collimated light is extracted from. Therefore, by providing a collimating lens instead of the reflecting mirror, light with high directivity can be reliably extracted.
  • FIGS. 4A to 5C are cross-sectional views showing the light-emitting elements of this embodiment.
  • FIG. 4A is a cross-sectional view showing the first light emitting element 7a.
  • FIG. 4B is a cross-sectional view showing the second light emitting element 7b.
  • FIG. 4C is a cross-sectional view showing the third light emitting element 7c.
  • FIGS. 4A to 4C are cross-sectional views showing the light-emitting elements of this embodiment.
  • FIG. 4A is a cross-sectional view showing the first light emitting element 7a.
  • FIG. 4B is a cross-sectional view showing the second light emitting element 7b.
  • FIG. 4C is a cross-sectional view showing the third light emitting element 7c.
  • FIGS. 5A to 5C are simulation results showing the relationship between the angle and the amount of emitted light in each light-emitting element of this embodiment.
  • FIG. 5A is a graph showing how light is extracted in the first light emitting element 7a with an inclination angle.
  • FIG. 5B is a graph showing a state of light extraction in the second light emitting element 7b.
  • FIG. 5C is a graph showing a state of light extraction in the third light emitting element 7c.
  • 5A to 5C is an angle (inclination angle) ⁇ [°] formed by the central axis of the concave mirror and the normal of the mounting surface.
  • the vertical axis of the graphs in FIGS. 5A to 5C represents the amount of luminous flux [lumen].
  • the basic configuration is the same as that of the light emitting device of the present embodiment, and the light source and the reflection mirror are embedded in the concave portion of the package with resin (light transmitting member).
  • the simulation conditions were as follows: in each light emitting element 7a, 7b, 7c, the size of the parabolic mirror (diameter of the circle viewed from the direction parallel to the central axis CL1) was 8 mm in diameter, and the size of the reflecting mirror (parallel to the central axis CL1).
  • the side of the square viewed from one direction) is 1 mm
  • the size of the chip LED one side of the square viewed from the direction parallel to the central axis CL1
  • the radius of curvature of the parabolic mirror is 5.4 mm
  • the embedded resin The refractive index was 1.5.
  • emitted toward the light guide 5 was calculated
  • the maximum amount of light flux emitted from the first light emitting element 7a was obtained at an inclination angle of 36.898 °. Further, the full width at half maximum (FWHM) of the intensity distribution of light emitted from the first light emitting element 7a was 3.2 °.
  • the maximum amount of light flux emitted from the second light emitting element 7b was obtained at an inclination angle of 25.928 °.
  • the half width (FWHM) of the intensity distribution of the light emitted from the second light emitting element 7b was 3.2 °.
  • the maximum amount of emitted light flux in the third light emitting element 7c was obtained at an inclination angle of 14.958 °. Further, the full width at half maximum (FWHM) of the intensity distribution of the light emitted from the third light emitting element 7c was 3.2 °.
  • FIG. 6 is a cross-sectional view showing the light emitting device of this embodiment.
  • the same components as those in FIG. 3 used in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.
  • the light source 73 and the reflection mirror 74 are embedded in the recess 71 a of the package 71 by the light transmission member 75, and the light emission surface of the light transmission member 75 is attached to the first end surface 5 c of the light guide 5. It was a surface.
  • the light emitting element 107 of the present embodiment as shown in FIG. 6, the light source 73 and the reflection mirror 74 are attached to the back surface 76 a of the lid member 76, and the lid member 76 is partly provided on the recess 71 a of the package 71. Is fitted, and the light emission surface (front surface) 76b of the lid member 76 is an attachment surface.
  • the lid member 76 is a member for closing the recess 71 a of the package 71.
  • the light emission surface 76b of the lid member 76 is a flat surface parallel to the mounting surface 71b of the package 71 described above.
  • the back surface 76a of the lid member 76 is a flat surface with the central axis CL1 of the concave mirror 72 as a normal line.
  • the shape of the lid member 76 is formed by a method such as injection molding of resin using a mold having a predetermined shape. Alternatively, the shape of the lid member 76 may be formed, for example, by cutting the surface of an originally flat resin member.
  • the recess 71a of the package 71 closed by the lid member 76 has a so-called hollow structure in which an air layer 175 is enclosed.
  • the concave portion 71a of the package 71 can be a hollow structure, and a light transmitting member can be arranged in the same manner as in the configuration of the first embodiment.
  • the light transmissive member is formed by disposing a concave mirror 72 in the concave portion 71a of the package 71, and injecting and curing a light transmissive resin such as an acrylic resin into the package 71, for example. can do.
  • a light transmissive resin such as an acrylic resin
  • the transmittance of the light transmitting member can be a value different from the refractive index nWG (1.5) of the light guide 5.
  • the liquid material can be taken in and out of the package 71 only by removing the lid member 76 by making the light transmitting member a liquid material. It becomes easy to change the transmittance of the transmissive member.
  • the lid member 76 is provided, it is possible to prevent impurities from entering the package 71 from the outside.
  • FIGS. 7, 8A and 8B a third embodiment of the present invention will be described with reference to FIGS. 7, 8A and 8B.
  • the basic configuration of the light emitting device of this embodiment is the same as that of the first embodiment, and only the shape of the concave portion of the package and the shape of the concave mirror are different from those of the first embodiment. Therefore, in this embodiment, description of the basic structure of a light emitting element is abbreviate
  • FIG. 7 is a perspective view showing the light emitting device of this embodiment.
  • 8A and 8B are schematic views showing the light emitting device of this embodiment.
  • FIG. 8A is a cross-sectional view of the light-emitting element.
  • FIG. 8B is a plan view of the light emitting element. 7, 8 ⁇ / b> A, and 8 ⁇ / b> B, the same components as those in FIG. 3 used in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.
  • the shape of the recess 71 a of the package 71 is concave with respect to the light source 73 as viewed from the normal of the virtual plane including the central axis CL 1 of the concave mirror 72 and the normal CL 2 of the mounting surface 71 b. It was like a curve.
  • the concave mirror 72 is a parabolic mirror, and the shape viewed from a direction parallel to the central axis CL1 of the concave mirror 72 is a circular rotationally symmetric shape.
  • the concave portion 271a of the package 271 has a curved shape that is concave with respect to the light source 73.
  • the shape when the concave portion 271a is cut by a virtual plane including the central axis CL1 of the concave mirror 272 and the normal line CL2 of the mounting surface 271b is the same. Further, the shape viewed from the direction parallel to the central axis CL1 of the concave mirror 272 is rectangular.
  • the reflected light from the concave mirror 272 has directivity on the virtual plane (XZ plane) as shown in FIG. 8A, and a plane (XY) orthogonal to the virtual plane as shown in FIG. 8B. In the plane). Therefore, it is possible to extract light having directivity in the vertical direction and spreading in the horizontal direction.
  • FIG. 9 is an exploded perspective view showing a schematic configuration of a liquid crystal display device which is a configuration example of the display device.
  • FIG. 10A, FIG. 10B, FIG. 11A, and FIG. 11B are diagrams showing examples of backlight arrangement in a liquid crystal display device.
  • the liquid crystal display device 121 of this configuration example includes a lower case 122, a reflecting plate 123, a backlight 3 (light control element), a diffusion plate 124, and a liquid crystal panel 2 (display element). And an upper case 125. That is, a laminated body of the reflecting plate 123, the backlight 3, the diffusion plate 124, and the liquid crystal panel 2 is accommodated in the lower case 122 and the upper case 125.
  • the reflector 123 on the opposite side of the backlight 3 from the liquid crystal panel 2
  • light leaking from the backlight 3 to the opposite side of the liquid crystal panel 2 can be reflected and contributed to display.
  • the diffusion plate 124 between the backlight 3 and the liquid crystal panel 2
  • luminance unevenness of the backlight 3 can be reduced.
  • the reflecting plate 123 and the diffusing plate 124 are not necessarily used.
  • FIG. 10A a configuration in which a plurality of backlights 3 are arranged in the screen of the liquid crystal display device 121 so that the light extraction areas RA, RB, RC are arranged in the vertical direction of the screen can be employed.
  • FIG. 10B a configuration in which a plurality of backlights 3 are arranged so that the light extraction areas RA, RB, RC are arranged in the horizontal direction of the screen in the screen of the liquid crystal display device 127 is adopted. Can do.
  • the light extraction regions RA, RB, RC are provided only in a part in the longitudinal direction, and the other portions are elongated rod-shaped light guides 135 that are regions where light is guided.
  • a backlight 137 that combines a plurality of (three in this example) may be used.
  • regions where the light extraction regions RA, RB, RC are provided are shifted in the longitudinal direction. Therefore, when a plurality of light guides 135 are combined, the light extraction regions RA, RB, and RC are arranged along the longitudinal direction of the light guide 135.
  • a plurality of backlights 137 may be arranged in the screen of the liquid crystal display device 131 so that the light extraction areas RA, RB, RC are arranged in the vertical direction of the screen.
  • a plurality of backlights 137 may be arranged in the screen of the liquid crystal display device 133 so that the light extraction areas RA, RB, RC are arranged in the horizontal direction of the screen.
  • FIG. 12 is a cross-sectional view of the lighting device as the first configuration example.
  • 13A and 13B are diagrams showing a lighting apparatus as a second configuration example.
  • FIG. 13A is a plan view of the lighting apparatus as a second configuration example, and
  • FIG. 13B is a line AA ′ in FIG. 13A. It is sectional drawing of the illuminating device which is the 2nd structural example which follows.
  • the first low refractive index body 8a having a refractive index of 1.3 is formed on the first main surface 5a side of the light guide 5 and the refractive index is on the second main surface 5b side.
  • a second low refractive index body 8b of 1.4 is formed.
  • a light scatterer 10 is stacked on the first low refractive index body 8a and the second low refractive index body 8b.
  • Other configurations are the same as those of the first embodiment.
  • only one first end face 5c is shown, but actually, another one first end face having a different angle with respect to the first main face 5a is formed in the depth direction of the paper.
  • the light emitting element only one light emitting element 7a is shown, but actually another one LED is installed in the depth direction of the drawing.
  • the light emitting element 201 emits light from the first main surface 5a side depending on which one of the two light emitting elements provided on the first end surface 5c of the light guide 5 is lit. It is possible to switch whether light is emitted from the two principal surfaces 5b side. Therefore, it is possible to realize an illumination device that can switch the light emitting surface.
  • a character portion 204 written “SHARP” is formed on one surface of the light guide 5.
  • a first low refractive index body 8a having a refractive index of 1.3 is formed on the first main surface 5a side of the light guide 5, and the character portion 204 is formed.
  • the first low refractive index body 8a is not formed in any other part.
  • a light scatterer 10 is stacked on the first low refractive index body 8a. That is, the character part 204 is a light extraction area in the above embodiment. Other configurations are the same as those of the first embodiment. Although only one first end face 5c is shown in FIG.
  • the lighting device 203 light is emitted from the character part 204 depending on which of the two light emitting elements provided on the first end surface 5 c of the light guide 5 is lit, or other than the character part 204. It is possible to switch whether light is emitted from Therefore, according to this structure, the illuminating device which can be utilized as digital signage which can blink the character part 204, for example is realizable.
  • the technical scope in the aspect of the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the aspect of the present invention.
  • three light emitting elements are arranged side by side in the short direction of the light guide (y-axis direction in FIG. 1).
  • a plurality of light emitting elements are arranged in the light guide. May be arranged side by side in the thickness direction (z-axis direction in FIG. 1).
  • the configuration in which the light emitting element is disposed on the end face of the light guide has been described as an example.
  • the present invention is not limited thereto, and the light emitting element can be used alone.
  • refraction of light on the mounting surface of the light emitting element is considered.
  • the mounting surface of the light emitting element is an interface between a light transmitting member having a refractive index of 1.5 and an air layer having a refractive index of 1.0.
  • the inclination angle of the concave mirror is set to about 10 °.
  • an optical member such as a light diffusion film or a prism sheet may be appropriately disposed between the liquid crystal panel and the backlight.
  • a light diffusion film or a prism sheet may be appropriately disposed between the liquid crystal panel and the backlight.
  • these optical members it is possible to further reduce luminance unevenness and adjust the light diffusion angle and direction.
  • the shape, size, number, arrangement, constituent material, manufacturing method, and the like of various components in the above embodiment are not limited to those illustrated in the above embodiment, and can be changed as appropriate.
  • the aspect of the present invention can be used for a liquid crystal display device and other various display devices capable of performing display using a light control element including a light emitting element.

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Abstract

This light emitting element has a mounting surface. The light emitting element is provided with a package in which a recessed part is formed, a concave mirror provided in that recessed part of the package, and a light source disposed at a focal point of the concave mirror. A straight line connecting the center point of the concave mirror and the focal point crosses the normal line of the mounting surface obliquely.

Description

発光素子、調光素子、表示装置および照明装置LIGHT EMITTING ELEMENT, LIGHT ADJUSTING ELEMENT, DISPLAY DEVICE, AND LIGHTING DEVICE
　本発明は、発光素子、調光素子、表示装置および照明装置に関するものである。
　本願は、２０１０年１２月１６日に、日本に出願された特願２０１０－２８０２６３号に基づき優先権を主張し、その内容をここに援用する。 The present invention relates to a light emitting element, a light control element, a display device, and a lighting device.
This application claims priority based on Japanese Patent Application No. 2010-280263 filed in Japan on December 16, 2010, the contents of which are incorporated herein by reference.
　発光素子の一例として、発光ダイオード（Ｌｉｇｈｔ　Ｅｍｉｔｔｉｎｇ　Ｄｉｏｄｅ，以下、ＬＥＤと略記する）等の光源を備えた発光素子が知られている。 As an example of a light emitting element, a light emitting element having a light source such as a light emitting diode (hereinafter abbreviated as LED) is known.
　例えば、発光素子の一例として、基板に実装された光源を備え、光源から射出された光を反射して外部に反射する反射面を有する反射型発光ダイオードの構成を有する発光素子が開示されている（下記の特許文献１参照）。この発光素子は、ＬＥＤ実装基板の法線方向から光の取り出しを行っている。 For example, as an example of a light-emitting element, a light-emitting element having a configuration of a reflective light-emitting diode that includes a light source mounted on a substrate and has a reflective surface that reflects light emitted from the light source and reflects it to the outside is disclosed. (See Patent Document 1 below). This light emitting element extracts light from the normal direction of the LED mounting substrate.
　また、発光素子の他の例として、基板に実装された光源と、入射面と反射面が複数形成された配向制御部材と、を備えた形態の発光素子が開示されている（下記の特許文献２参照）。この発光素子は、ＬＥＤ実装基板の法線方向とは異なる方向から光の取り出しを行っている。 Further, as another example of the light emitting element, a light emitting element having a light source mounted on a substrate and an orientation control member having a plurality of incident surfaces and reflecting surfaces is disclosed (the following patent document) 2). This light emitting element extracts light from a direction different from the normal direction of the LED mounting substrate.
特許第３９８２６３５号公報Japanese Patent No. 3968235 特開２００７－２８７６８６号公報JP 2007-287686 A
　しかしながら、特許文献１の技術では、指向性を持った光を取り出すことはできるものの、光をＬＥＤ実装基板の法線に対して斜め方向に取り出すことはできない。例えば、発光素子を対象物の一面（例えば導光板の端面など、発光素子が取り付けられる面）に取り付けた場合、光を対象物の一面の法線に対して斜め方向に取り出すことはできない。 However, although the technique of Patent Document 1 can extract light having directivity, it cannot extract light obliquely with respect to the normal line of the LED mounting substrate. For example, when a light emitting element is attached to one surface of an object (for example, a surface to which the light emitting element is attached, such as an end face of a light guide plate), light cannot be extracted in an oblique direction with respect to the normal of the one surface of the object.
　一方、光を対象物の一面の法線に対して斜め方向に取り出すために、対象物の一面を斜めにカットすることも考えられるが、対象物の形状が複雑となり、加工に手間がかかる。 On the other hand, in order to extract light in an oblique direction with respect to the normal of one surface of the object, it is conceivable to cut one surface of the object obliquely, but the shape of the object is complicated, and processing is troublesome.
　また、特許文献２の技術では、指向性を持った光を取り出すことはできない。そのため、発光素子の適用として、指向性の高い光がほとんど要求されない照明装置等の用途には適用できるものの、指向性の高い光が要求される装置には適用することができない。 In addition, the technique of Patent Document 2 cannot extract light having directivity. Therefore, the light-emitting element can be applied to an application such as a lighting device that hardly requires light having high directivity, but cannot be applied to a device that requires light having high directivity.
　本発明の態様は、上記の課題を解決するためになされたものであって、指向性の高い光を対象物の一面の法線に対して斜め方向に取り出すことが可能な発光素子の提供を目的の一つとする。
　また、上記の発光素子を用いることで光量が十分に得られる調光素子の提供を目的の一つとする。また、上記の調光素子を用いることで明るく、コントラストの高い表示が可能な表示装置の提供を目的の一つとする。 An aspect of the present invention is made to solve the above-described problem, and provides a light-emitting element capable of extracting light with high directivity in an oblique direction with respect to a normal line of one surface of an object. One of the purposes.
Another object is to provide a light control element that can obtain a sufficient amount of light by using the light emitting element. Another object is to provide a display device that can display brightly and with high contrast by using the above light control element.
　上記の目的を達成するために、本発明の一態様における発光素子は、導光体に取り付けるための取付面を有し、前記発光素子は、凹部が形成されたパッケージと、前記パッケージの前記凹部に設けられた凹面ミラーと、前記凹面ミラーの焦点に配置された光源と、を備え、前記凹面ミラーの中心点と前記焦点とを結ぶ直線は、前記取付面の法線と斜めに交差している。 In order to achieve the above object, a light-emitting element according to one embodiment of the present invention includes a mounting surface for mounting on a light guide, and the light-emitting element includes a package in which a recess is formed, and the recess in the package. And a light source disposed at the focal point of the concave mirror, and a straight line connecting the central point of the concave mirror and the focal point obliquely intersects the normal of the mounting surface Yes.
　本発明の一態様における発光素子は、前記直線は、前記光源の光射出面の法線と一致していてもよい。 In the light-emitting element according to one embodiment of the present invention, the straight line may coincide with a normal line of a light emission surface of the light source.
　本発明の一態様における発光素子は、前記凹面ミラーは、放物面ミラーであり、前記直線は、前記放物面ミラーの回転対称軸と一致していてもよい。 In the light-emitting element according to one embodiment of the present invention, the concave mirror may be a parabolic mirror, and the straight line may coincide with a rotational symmetry axis of the parabolic mirror.
　本発明の一態様における発光素子は、さらに反射ミラーを備え、前記反射ミラーは、前記光源が前記凹面ミラーと前記反射ミラーとの間に配置されるように配置され、前記反射ミラーは、前記凹面ミラーと異なる方向に射出された前記光源からの光を、前記凹面ミラーに向けて反射してもよい。 The light-emitting element according to one embodiment of the present invention further includes a reflection mirror, and the reflection mirror is disposed such that the light source is disposed between the concave mirror and the reflection mirror, and the reflection mirror is the concave surface. Light from the light source emitted in a direction different from the mirror may be reflected toward the concave mirror.
　本発明の一態様における発光素子は、さらに、前記光源から射出された光を透過する光透過部材を備え、前記光源は、前記パッケージの前記凹部に、前記光透過部材によって埋設されており、前記光透過部材は、前記取付面を形成していてもよい。 The light-emitting element according to one embodiment of the present invention further includes a light transmissive member that transmits light emitted from the light source, and the light source is embedded in the concave portion of the package by the light transmissive member, The light transmission member may form the mounting surface.
　本発明の一態様における発光素子は、さらに蓋部材を備え、前記蓋部材は、前記取付面を形成し、前記蓋部材は、前記凹部を閉塞するよう配置されていてもよい。 The light-emitting element according to one embodiment of the present invention may further include a lid member, the lid member may form the attachment surface, and the lid member may be disposed so as to close the recess.
　本発明の一態様における発光素子は、前記蓋部材の裏面に、前記光源が取り付けられていてもよい。 In the light-emitting element according to one embodiment of the present invention, the light source may be attached to the back surface of the lid member.
　本発明の他の態様における調光素子は、射出する光の量を制御可能な照明部と、前記照明部から射出された光が入射され、前記光を内部で全反射させつつ伝播させる導光体とを備え、前記導光体は、前記照明部から射出された光が導光体内部で全反射しつつ伝播される間に前記光を外部に取り出す複数の光取出領域を有し、前記複数の光取出領域のうちの少なくとも２つの光取出領域は、前記照明部から射出された光を外部に取り出し可能な入射角範囲が互いに異なり、前記導光体は、前記照明部から射出された光を、前記導光体の内部を複数の異なる伝播角度で伝播させるよう構成され、前記照明部は、前記導光体に取り付けるための取付面を有する発光素子を備え、前記発光素子は、凹部が形成されたパッケージと、前記パッケージの前記凹部に設けられた凹面ミラーと、前記凹面ミラーの焦点に配置された光源と、を備え、前記凹面ミラーの中心点と前記焦点とを結ぶ直線は、前記取付面の法線と斜めに交差している。 The light control device according to another aspect of the present invention includes an illumination unit capable of controlling the amount of emitted light, and a light guide that receives the light emitted from the illumination unit and propagates the light while totally reflecting the light inside. And the light guide has a plurality of light extraction regions for extracting the light to the outside while the light emitted from the illumination unit is propagated while being totally reflected inside the light guide, At least two light extraction regions of the plurality of light extraction regions have different incident angle ranges in which light emitted from the illumination unit can be extracted to the outside, and the light guide is emitted from the illumination unit The light is configured to propagate inside the light guide at a plurality of different propagation angles, the illumination unit includes a light emitting element having an attachment surface for attaching to the light guide, and the light emitting element includes a recess. A package formed with the package A concave mirror provided in the concave portion and a light source disposed at the focal point of the concave mirror, and a straight line connecting the center point of the concave mirror and the focal point obliquely intersects with the normal of the mounting surface is doing.
　本発明の他の態様における調光素子は、前記導光体の端面は、前記光取出領域が設けられた面に対して直交しており、前記導光体の端面には、前記発光素子が複数配置されており、前記複数の発光素子の各々は、射出された光が前記光取出領域に対して互いに異なる入射角で入射するように、前記直線が前記光取出領域に対して異なる向きになるよう配置されていてもよい。 In the light control device according to another aspect of the present invention, the end surface of the light guide is orthogonal to the surface on which the light extraction region is provided, and the light emitting device is disposed on the end surface of the light guide. A plurality of light emitting elements are arranged, and each of the plurality of light emitting elements has the straight line in a different direction with respect to the light extraction region so that the emitted light is incident on the light extraction region at different incident angles. It may be arranged so that.
　本発明のさらに他の態様における表示装置は、前述の調光素子と、前記調光素子から射出される光を用いて表示を行う表示素子と、を備える。 A display device according to still another aspect of the present invention includes the above-described dimming element and a display element that performs display using light emitted from the dimming element.
　本発明のさらに他の態様における照明装置は、前述の調光素子を備える。 A lighting device according to still another aspect of the present invention includes the above-described dimming element.
　本発明の態様によれば、指向性の高い光を対象物の一面の法線に対して斜め方向に取り出すことが可能な発光素子を実現することができる。また、上記の発光素子を用いることで光量が十分に得られる調光素子を実現することができる。また、上記の調光素子を用いることで明るく、コントラストの高い表示が可能な表示装置を実現することができる。 According to the aspect of the present invention, it is possible to realize a light emitting element capable of extracting light with high directivity in an oblique direction with respect to the normal line of one surface of an object. In addition, it is possible to realize a light control element that can obtain a sufficient amount of light by using the light emitting element. In addition, a bright display device with high contrast can be realized by using the dimmer element.
第１の実施形態の液晶表示装置およびバックライトを示す斜視図である。It is a perspective view which shows the liquid crystal display device and backlight of 1st Embodiment. 第１の実施形態のバックライトにおいて各光取出領域から光が射出する原理を説明するための図である。It is a figure for demonstrating the principle in which light inject | emits from each light extraction area | region in the backlight of 1st Embodiment. 第１の実施形態のバックライトにおいて各光取出領域から光が射出する原理を説明するための図である。It is a figure for demonstrating the principle in which light inject | emits from each light extraction area | region in the backlight of 1st Embodiment. 第１の実施形態のバックライトにおいて各光取出領域から光が射出する原理を説明するための図である。It is a figure for demonstrating the principle in which light inject | emits from each light extraction area | region in the backlight of 1st Embodiment. 第１の実施形態の発光素子を示す断面図である。It is sectional drawing which shows the light emitting element of 1st Embodiment. 第１の実施形態の第１発光素子を示す断面図である。It is sectional drawing which shows the 1st light emitting element of 1st Embodiment. 第１の実施形態の第２発光素子を示す断面図である。It is sectional drawing which shows the 2nd light emitting element of 1st Embodiment. 第１の実施形態の第３発光素子を示す断面図である。It is sectional drawing which shows the 3rd light emitting element of 1st Embodiment. 第１の実施形態の第１発光素子における角度と射出光束量の関係を示すシミュレーション結果である。It is a simulation result which shows the relationship between the angle in the 1st light emitting element of 1st Embodiment, and an emitted light beam quantity. 第１の実施形態の第２発光素子における角度と射出光束量の関係を示すシミュレーション結果である。It is a simulation result which shows the relationship between the angle in the 2nd light emitting element of 1st Embodiment, and an emitted light beam quantity. 第１の実施形態の第３発光素子における角度と射出光束量の関係を示すシミュレーション結果である。It is a simulation result which shows the relationship between the angle in the 3rd light emitting element of 1st Embodiment, and an emitted light beam quantity. 第２の実施形態の発光素子を示す断面図である。It is sectional drawing which shows the light emitting element of 2nd Embodiment. 第３の実施形態の発光素子を示す斜視図である。It is a perspective view which shows the light emitting element of 3rd Embodiment. 第３の実施形態の発光素子を示す模式図である。It is a schematic diagram which shows the light emitting element of 3rd Embodiment. 第３の実施形態の発光素子を示す模式図である。It is a schematic diagram which shows the light emitting element of 3rd Embodiment. 液晶表示装置の一構成例を示す概略構成図である。It is a schematic block diagram which shows the example of 1 structure of a liquid crystal display device. 液晶表示装置におけるバックライトの配置例を示す図である。It is a figure which shows the example of arrangement | positioning of the backlight in a liquid crystal display device. 液晶表示装置におけるバックライトの配置例を示す図である。It is a figure which shows the example of arrangement | positioning of the backlight in a liquid crystal display device. 液晶表示装置におけるバックライトの配置例を示す図である。It is a figure which shows the example of arrangement | positioning of the backlight in a liquid crystal display device. 液晶表示装置におけるバックライトの配置例を示す図である。It is a figure which shows the example of arrangement | positioning of the backlight in a liquid crystal display device. 照明装置の一例を示す断面図である。It is sectional drawing which shows an example of an illuminating device. 照明装置の一例を示す平面図である。It is a top view which shows an example of an illuminating device. 照明装置の一例を示す図１３ＡのＡ－Ａ’線に沿う断面図である。FIG. 13B is a cross-sectional view taken along the line A-A ′ of FIG. 13A showing an example of a lighting device.
[第１の実施形態]
　以下、本発明の第１の実施形態について、図１～図５Ｃを用いて説明する。
　本実施形態では、表示素子に液晶パネルを用いた液晶表示装置を例示する。
　図１は、本実施形態の液晶表示装置およびバックライトを示す斜視図である。図２Ａ～２Ｃは、本実施形態のバックライトにおいて各光取出領域から光が射出する原理を説明するための図である。図２Ａは、第１光取出領域ＲＡから光が射出する場合を示している。図２Ｂは、第２光取出領域ＲＢから光が射出する場合を示している。図２Ｃは、第３光取出領域ＲＣから光が射出する場合を示している。図３は、本実施形態の発光素子を示す断面図である。図４Ａ～４Ｃは、本実施形態の各発光素子を示す断面図である。図５Ａ～５Ｃは、本実施形態の各発光素子における角度と射出光束量の関係を示すシミュレーション結果である。
　なお、以下の各図面においては各構成要素を見やすくするため、構成要素によって寸法の縮尺を異ならせて示すことがある。 [First embodiment]
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. 1 to 5C.
In the present embodiment, a liquid crystal display device using a liquid crystal panel as a display element is illustrated.
FIG. 1 is a perspective view showing a liquid crystal display device and a backlight according to the present embodiment. 2A to 2C are diagrams for explaining the principle of light emitted from each light extraction region in the backlight according to the present embodiment. FIG. 2A shows a case where light is emitted from the first light extraction area RA. FIG. 2B shows a case where light is emitted from the second light extraction region RB. FIG. 2C shows a case where light is emitted from the third light extraction region RC. FIG. 3 is a cross-sectional view showing the light emitting device of this embodiment. 4A to 4C are cross-sectional views showing the light-emitting elements of this embodiment. FIGS. 5A to 5C are simulation results showing the relationship between the angle and the amount of emitted light in each light-emitting element of this embodiment.
In the following drawings, in order to make each component easy to see, the scale of the size may be varied depending on the component.
　本実施形態の液晶表示装置１（表示装置）は、図１に示すように、液晶パネル２（表示素子）と、液晶パネル２の背面側に配置されたバックライト３（調光素子）と、を有している。液晶パネル２は、バックライト３から射出された光を利用して表示を行う透過型の液晶パネルである。使用者は、バックライト３の反対側、すなわち、図１における液晶パネル２の上側から表示を視認することができる。本実施形態において、液晶パネル２の構成は特に限定されるものではなく、スイッチング用薄膜トランジスタ（Ｔｈｉｎ　Ｆｉｌｍ　Ｔｒａｎｓｉｓｔｏｒ，以下、ＴＦＴと略記する）を画素毎に備えたアクティブマトリクス型液晶パネルであっても良いし、ＴＦＴを備えていない単純マトリクス方式の液晶パネルであっても良い。また、透過型の液晶パネルに限らず、半透過型（透過・反射兼用型）液晶パネルであっても良い。表示モードについても、特に限定されることはなく、ＶＡ（Ｖｅｒｔｉｃａｌ　Ａｌｉｇｎｍｅｎｔ）モード、ＴＮ（Ｔｗｉｓｔｅｄ　Ｎｅｍａｔｉｃ）モード、ＳＴＮ（Ｓｕｐｅｒ　Ｔｗｉｓｔｅｄ　Ｎｅｍａｔｉｃ）モード、ＩＰＳ（Ｉｎ－Ｐｌａｎｅ　Ｓｗｉｔｃｈｉｎｇ）モード等、種々の表示モードの液晶パネルを用いることができる。 As shown in FIG. 1, the liquid crystal display device 1 (display device) of the present embodiment includes a liquid crystal panel 2 (display element), a backlight 3 (light control element) disposed on the back side of the liquid crystal panel 2, have. The liquid crystal panel 2 is a transmissive liquid crystal panel that performs display using light emitted from the backlight 3. The user can view the display from the opposite side of the backlight 3, that is, from the upper side of the liquid crystal panel 2 in FIG. In the present embodiment, the configuration of the liquid crystal panel 2 is not particularly limited, and may be an active matrix liquid crystal panel including a switching thin film transistor (hereinafter abbreviated as TFT) for each pixel. A simple matrix type liquid crystal panel that does not include a TFT may be used. In addition, the liquid crystal panel is not limited to a transmissive liquid crystal panel, and may be a transflective liquid crystal panel. The display mode is not particularly limited, and there are various display modes such as VA (Vertical Alignment) mode, TN (Twisted Nematic) mode, STN (Super Twisted Nematic) mode, IPS (In-Plane Switching) mode, etc. A liquid crystal panel can be used.
　本実施形態のバックライト３は、後述する導光体の全面から光が均一に射出される訳ではなく、全面を複数個（本実施形態では９個）に分割した光取出領域毎に、射出される光の量を制御できるようになっている。すなわち、本実施形態のバックライト３は、複数の光取出領域の各々が調光機能を有している。バックライト３全体として、特定の光取出領域だけ光を射出させたり、射出させなかったりすることができる。あるいは、特定の光取出領域から射出される光の量を他の光取出領域から射出される光の量に対して変化させることができる。 The backlight 3 of the present embodiment does not emit light uniformly from the entire surface of the light guide, which will be described later, but emits light for each light extraction region in which the entire surface is divided into a plurality (9 in this embodiment). The amount of light emitted can be controlled. That is, in the backlight 3 of the present embodiment, each of the plurality of light extraction regions has a dimming function. As a whole of the backlight 3, it is possible to emit light only in a specific light extraction region or not. Alternatively, the amount of light emitted from a specific light extraction region can be changed with respect to the amount of light emitted from another light extraction region.
　バックライト３は、発光素子７ａ，７ｂ，７ｃを備えている。以下、発光素子の基本構成について図３を用いて説明する。 The backlight 3 includes light emitting elements 7a, 7b, and 7c. Hereinafter, a basic configuration of the light-emitting element will be described with reference to FIG.
　図３は、発光素子を示す断面図である。図３は、第１端面５ｃに設けられた３つの発光素子７ａ，７ｂ，７ｃの基本構成（発光素子７）を示している。 FIG. 3 is a cross-sectional view showing the light emitting element. FIG. 3 shows a basic configuration (light emitting element 7) of three light emitting elements 7a, 7b, 7c provided on the first end face 5c.
　発光素子７は、図３に示すように、パッケージ７１と、凹面ミラー７２と、光源７３と、反射ミラー７４と、光透過部材７５と、を備えている。凹面ミラー７２は、パッケージ７１の凹部７１ａに設けられている。凹面ミラー７２の形状は、パッケージ７１の凹部７１ａの形状に倣った曲線状となっている。凹面ミラー７２は、光源７３から射出された光を反射する放物面ミラーである。光源７３は、パッケージ７１の凹部７１ａに、光源７３から射出された光を透過する光透過部材７５によって埋設されている。 The light emitting element 7 includes a package 71, a concave mirror 72, a light source 73, a reflection mirror 74, and a light transmission member 75, as shown in FIG. The concave mirror 72 is provided in the concave portion 71 a of the package 71. The shape of the concave mirror 72 is a curved shape that follows the shape of the concave portion 71 a of the package 71. The concave mirror 72 is a parabolic mirror that reflects the light emitted from the light source 73. The light source 73 is embedded in the recess 71 a of the package 71 by a light transmitting member 75 that transmits light emitted from the light source 73.
　なお、図３において、符号Ｐｆは凹面ミラー７２の焦点、符号Ｐｃは凹面ミラー７２の中心点、符号ＣＬ１は凹面ミラー７２の中心軸（凹面ミラー７２の中心点Ｐｃと凹面ミラー７２の焦点Ｐｆを結ぶ線）、符号ＣＬ２は取付面７１ｂの法線、符号θは凹面ミラー７２の傾斜角度である。ここで、凹面ミラー７２の傾斜角度とは、凹面ミラー７２の中心軸と取付面７１ｂの法線とのなす角度である。 In FIG. 3, symbol Pf is the focal point of the concave mirror 72, symbol Pc is the central point of the concave mirror 72, symbol CL1 is the central axis of the concave mirror 72 (the central point Pc of the concave mirror 72 and the focal point Pf of the concave mirror 72). The line CL) is a normal line of the mounting surface 71 b, and the sign θ is an inclination angle of the concave mirror 72. Here, the inclination angle of the concave mirror 72 is an angle formed by the central axis of the concave mirror 72 and the normal line of the mounting surface 71b.
　パッケージ７１の内部には、凹部７１ａが形成されている。パッケージ７１は、直方体状となっており、光が射出される側に（凹部７１ａが形成された部分の端部に）、取付面７１ｂを有している。この取付面７１ｂは、発光素子７を導光体５の第１端面５ｃに取り付ける際の取付面となる平坦面である。パッケージ７１の凹部７１ａの形状は、凹面ミラー７２の中心軸ＣＬ１と取付面７１ｂの法線ＣＬ２を含む仮想面の法線から見て、光源７３に対して凹となるような曲線状となっている。すなわち、曲線の接線の傾きは凹部７１ａの中心点に近づくに従って徐々に緩やかとなっている。 A recess 71 a is formed in the package 71. The package 71 has a rectangular parallelepiped shape, and has a mounting surface 71b on the side from which light is emitted (at the end of the portion where the recess 71a is formed). The attachment surface 71 b is a flat surface that serves as an attachment surface when the light emitting element 7 is attached to the first end surface 5 c of the light guide 5. The shape of the concave portion 71a of the package 71 is a curved shape that is concave with respect to the light source 73 when viewed from the normal surface of the virtual surface including the central axis CL1 of the concave mirror 72 and the normal line CL2 of the mounting surface 71b. Yes. That is, the slope of the tangent line of the curve gradually becomes gentler as it approaches the center point of the recess 71a.
　本実施形態の場合、パッケージ７１の凹部７１ａの形状は、凹部７１ａの形状を反転させた凸形状を有する金型を用いて樹脂の射出成形を行うなどの方法によって形成されている。あるいは、パッケージ７１の凹部７１ａの形状は、例えば元々平坦な樹脂部材の表面を切削加工することによって形成しても良い。 In the case of the present embodiment, the shape of the recess 71a of the package 71 is formed by a method such as resin injection molding using a mold having a convex shape obtained by inverting the shape of the recess 71a. Or you may form the shape of the recessed part 71a of the package 71 by cutting the surface of the originally flat resin member, for example.
　凹面ミラー７２の中心軸ＣＬ１は、取付面７１ｂの法線ＣＬ２と所定の角度（傾斜角度）θをなして斜めに交差している。また、凹面ミラー７２の中心軸ＣＬ１は、放物面ミラーの回転対象軸と一致している。本実施形態の一例として、放物面ミラーのサイズ（中心軸ＣＬ１と平行な方向から視た円の直径）は、直径８ｍｍに設定されている。放物面ミラーの曲率半径は、５．４ｍｍに設定されている。 The central axis CL1 of the concave mirror 72 obliquely intersects the normal line CL2 of the mounting surface 71b with a predetermined angle (inclination angle) θ. Further, the central axis CL1 of the concave mirror 72 coincides with the rotation target axis of the parabolic mirror. As an example of the present embodiment, the size of the parabolic mirror (the diameter of a circle viewed from a direction parallel to the central axis CL1) is set to a diameter of 8 mm. The radius of curvature of the parabolic mirror is set to 5.4 mm.
　なお、ここでは、凹面ミラー７２が放物面ミラーである例を示すが、これに限らず、例えば球面ミラーであってもよい。また、凹面ミラー７２としては、凹面ミラー７２の中心軸ＣＬ１と平行な方向から視た形状が円形の回転対称形状のものに限らず、楕円球ミラーなど、凹面ミラー７２の中心軸ＣＬ１と平行な方向から視た形状が非円形の非回転対称形状のものを選択することも可能である。 In addition, although the example in which the concave mirror 72 is a parabolic mirror is shown here, it is not limited to this, and may be a spherical mirror, for example. Further, the concave mirror 72 is not limited to a circular rotationally symmetric shape as viewed from a direction parallel to the central axis CL1 of the concave mirror 72, and is parallel to the central axis CL1 of the concave mirror 72 such as an elliptical mirror. It is also possible to select a non-rotationally symmetric shape that is non-circular when viewed from the direction.
　光源７３は、略直方体状のチップＬＥＤ（表面実装用ＬＥＤ）である。凹面ミラー７２の中心軸ＣＬ１は、光源７３の光射出面の法線（チップＬＥＤの上面の法線）と一致している。 The light source 73 is a substantially rectangular parallelepiped chip LED (surface mounting LED). The central axis CL1 of the concave mirror 72 coincides with the normal line of the light emission surface of the light source 73 (the normal line of the upper surface of the chip LED).
　光源７３の凹面ミラー７２が配置された側と反対の側には、反射ミラー７４が設けられている。すなわち、光源７３は、凹面ミラー７２と反射ミラー７４の間に配置されている。反射ミラー７４は、光源７３の実装基板に、例えばアルミニウム等の金属膜をスパッタ法もしくは蒸着法で形成するなどして形成することができる。反射ミラー７４は、凹面ミラー７２と異なる方向に射出された光源７３からの光を凹面ミラー７２に向けて反射する。本実施形態の一例として、チップＬＥＤのサイズ（中心軸ＣＬ１と平行な方向から視た正方形の一辺）は、２５０μｍに設定されている。反射ミラーのサイズ（中心軸ＣＬ１と平行な方向から視た正方形の一辺）は、１ｍｍに設定されている。 A reflection mirror 74 is provided on the side of the light source 73 opposite to the side where the concave mirror 72 is disposed. That is, the light source 73 is disposed between the concave mirror 72 and the reflection mirror 74. The reflection mirror 74 can be formed on the mounting substrate of the light source 73 by, for example, forming a metal film such as aluminum by sputtering or vapor deposition. The reflection mirror 74 reflects light from the light source 73 emitted in a different direction from the concave mirror 72 toward the concave mirror 72. As an example of the present embodiment, the size of the chip LED (one side of a square viewed from a direction parallel to the central axis CL1) is set to 250 μm. The size of the reflecting mirror (one side of the square viewed from the direction parallel to the central axis CL1) is set to 1 mm.
　なお、図３では図示を省略したが、反射ミラー７４の一部には、光源７３が実装されるプリント配線板などが設けられている。例えば、反射ミラー７４において、光源７３の裏面に対応する部分を実装領域とし、その他の部分（実装領域の周辺部分）を反射領域とすることができる。反射ミラー７４の実装領域に形成された各種配線は、上述した発光素子７ａ，７ｂ，７ｃが実装されるプリント配線板、発光素子７ａ，７ｂ，７ｃの駆動および制御を担う駆動用ＩＣを含む制御部などに電気的に接続される。 Although not shown in FIG. 3, a part of the reflection mirror 74 is provided with a printed wiring board on which the light source 73 is mounted. For example, in the reflection mirror 74, a portion corresponding to the back surface of the light source 73 can be a mounting region, and the other portion (a peripheral portion of the mounting region) can be a reflection region. Various wirings formed in the mounting region of the reflection mirror 74 include a printed wiring board on which the light emitting elements 7a, 7b, and 7c described above are mounted, and a control including a driving IC that is responsible for driving and controlling the light emitting elements 7a, 7b, and 7c. It is electrically connected to the part.
　光源７３は、パッケージ７１の凹部７１ａに光透過部材７５によって埋設されている。
　光透過部材７５は、以下の方法により形成することができる。パッケージ７１の凹部７１ａに凹面ミラー７２を配置し、パッケージ７１の内部に光源７３および反射ミラー７４を配置する。その後、このパッケージ７１の内部に、例えばアクリル樹脂等の光透過性を有する樹脂を注入して硬化させる。本実施形態の一例として、光透過部材７５の屈折率は、導光体５の屈折率ｎＷＧ（１．５）と同じ値の１．５に設定されている。 The light source 73 is embedded in the recess 71 a of the package 71 with a light transmitting member 75.
The light transmissive member 75 can be formed by the following method. A concave mirror 72 is disposed in the recess 71 a of the package 71, and a light source 73 and a reflection mirror 74 are disposed inside the package 71. Thereafter, a resin having optical transparency such as an acrylic resin is injected into the package 71 and cured. As an example of this embodiment, the refractive index of the light transmitting member 75 is set to 1.5, which is the same value as the refractive index nWG (1.5) of the light guide 5.
　なお、発光素子から射出される光の射出角度（導光体５を伝播する伝播角度）を補正したり、射出角度を凹面ミラー７２の傾斜角度と異ならせたりするために、光透過部材７５の透過率を導光体５の屈折率ｎＷＧ（１．５）と異なる値にすることもできる。例えば、光透過部材７５の透過率の変更は、上述したように、光透過部材７５を形成する際に、屈折率の異なる材料を選択したり、樹脂材料に低屈折率材料を含有させ、これら低屈折率材料の濃度を異ならせたりすることによって行うことができる。 In order to correct the emission angle of light emitted from the light emitting element (propagation angle propagating through the light guide 5) or to make the emission angle different from the inclination angle of the concave mirror 72, The transmittance can be set to a value different from the refractive index nWG (1.5) of the light guide 5. For example, as described above, the transmittance of the light transmissive member 75 can be changed by selecting a material having a different refractive index when the light transmissive member 75 is formed, or by adding a low refractive index material to the resin material. This can be done by changing the concentration of the low refractive index material.
　次に、本実施形態のバックライト３の構成について説明する。
　本実施形態のバックライト３は、図１に示すように、寸法、形状、構成が全て概略同一の３個のバックライトユニット４から構成されている。３個のバックライトユニット４は、後述する導光体５の長手方向と直交する方向、すなわち、導光体５の３つの光取出領域ＲＡ，ＲＢ，ＲＣが並ぶ方向と直交する方向（図１のｙ軸方向）に互いに隣接して配置されている。したがって、バックライト３は、液晶表示装置１の画面における水平方向および垂直方向に沿って３個ずつ、合計９個の光取出領域ＲＡ，ＲＢ，ＲＣを有している。各バックライトユニット４は照明部６と導光体５とから構成されている。また、照明部６は複数（本実施形態では３個）の発光素子７ａ，７ｂ，７ｃから構成されている。導光体５は、例えばアクリル樹脂等の光透過性を有する樹脂からなる平行平板で構成されている。なお、ここでは、バックライト３が、導光体が別体とされた３個のバックライトユニット４から構成されている例を示すが、合計９個の光取出領域ＲＡ，ＲＢ，ＲＣを有する導光体が一体の構造であっても良い。この構造であっても、指向性の高い発光素子を用いることで光を射出させる光取出領域ＲＡ，ＲＢ，ＲＣを選択することが可能である。 Next, the configuration of the backlight 3 of the present embodiment will be described.
As shown in FIG. 1, the backlight 3 according to the present embodiment is composed of three backlight units 4 having substantially the same dimensions, shape, and configuration. The three backlight units 4 are in a direction orthogonal to the longitudinal direction of the light guide 5 described later, that is, a direction orthogonal to the direction in which the three light extraction regions RA, RB, RC of the light guide 5 are arranged (FIG. 1). In the y-axis direction). Therefore, the backlight 3 has a total of nine light extraction regions RA, RB, RC, three in each of the horizontal and vertical directions on the screen of the liquid crystal display device 1. Each backlight unit 4 includes an illumination unit 6 and a light guide 5. The illumination unit 6 includes a plurality (three in the present embodiment) of light emitting elements 7a, 7b, and 7c. The light guide 5 is composed of a parallel plate made of a resin having optical transparency such as acrylic resin. In addition, although the backlight 3 shows the example comprised from the three backlight units 4 by which the light guide was made into the different body here, it has a total of nine light extraction area | region RA, RB, RC. The light guide may have an integral structure. Even with this structure, it is possible to select the light extraction regions RA, RB, and RC for emitting light by using a light emitting element with high directivity.
　導光体５の１つの端面に、３個の発光素子７ａ，７ｂ，７ｃが光射出側を導光体５側に向けて設置されている。導光体５は、各発光素子７ａ，７ｂ，７ｃから射出された光が入射される。導光体５は、入射された光を内部で全反射させつつ、発光素子７ａ，７ｂ，７ｃが設置された端面側から反対側の端面（図１の－ｘ方向から＋ｘ方向）に向けて伝播させ、その間に外部空間に取り出す機能を有している。また、３個の発光素子７ａ，７ｂ，７ｃは、個々に独立して点灯、消灯が制御でき、さらに射出光量が制御できる構成となっている。なお、図１では図示を省略したが、バックライト３には、発光素子７ａ，７ｂ，７ｃが実装されるプリント配線板、発光素子７ａ，７ｂ，７ｃの駆動および制御を担う駆動用ＩＣを含む制御部などが備えられている。本実施形態には、高い指向性を有する発光素子７ａ，７ｂ，７ｃを用いることが好ましい。例えば、発光素子７ａ，７ｂ，７ｃとして、導光体５内部を光が導光する間の射出光の広がり角に対する強度分布の半値幅が５°程度の発光素子を用いることができる。 Three light emitting elements 7a, 7b, 7c are installed on one end face of the light guide 5 with the light emission side facing the light guide 5 side. The light guide 5 receives light emitted from the light emitting elements 7a, 7b, and 7c. The light guide 5 reflects the incident light from the inside to the opposite end surface (from the −x direction to the + x direction in FIG. 1) from the end surface side where the light emitting elements 7a, 7b, 7c are installed. It has the function of propagating and taking it out to the outside space. Further, the three light emitting elements 7a, 7b, and 7c can be individually controlled to be turned on / off, and the amount of emitted light can be controlled. Although not shown in FIG. 1, the backlight 3 includes a printed wiring board on which the light emitting elements 7a, 7b, and 7c are mounted, and a driving IC that is responsible for driving and controlling the light emitting elements 7a, 7b, and 7c. A control unit and the like are provided. In the present embodiment, it is preferable to use light emitting elements 7a, 7b, and 7c having high directivity. For example, as the light emitting elements 7a, 7b, and 7c, light emitting elements having a half value width of about 5 ° with respect to the spread angle of the emitted light while the light is guided through the light guide 5 can be used.
　導光体５の２つの主面のうち、液晶パネル２に対向する側の主面５ａには、複数（本実施形態では３つ）の光取出領域ＲＡ，ＲＢ，ＲＣが導光体５の長手方向（図１のｘ軸方向）に沿って設けられている。各光取出領域ＲＡ，ＲＢ，ＲＣには、低屈折率体８ａ，８ｂおよび屈折率体９と、光散乱体１０と、がこの順に積層されている。低屈折率体８ａ，８ｂは、導光体５の屈折率よりも低い屈折率を有する。屈折率体９は、導光体５の屈折率と等しい屈折率を有する。光散乱体１０は、各低屈折率体８ａ，８ｂおよび屈折率体９から射出された光を散乱させる。なお、以下の説明では、便宜上、各光取出領域を、発光素子７ａ，７ｂ，７ｃに近い側から遠い側に向けて、第１光取出領域ＲＡ、第２光取出領域ＲＢ、第３光取出領域ＲＣ、と称する。また、光取出領域ＲＡ，ＲＢ，ＲＣが設けられた導光体５の主面を第１主面５ａ、第１主面５ａの反対側の主面を第２主面５ｂ、発光素子７ａ，７ｂ，７ｃが設けられた導光体５の端面を第１端面５ｃ、第１端面５ｃの反対側の端面を第２端面５ｄ、と称する。 Of the two main surfaces of the light guide 5, a plurality of (three in this embodiment) light extraction regions RA, RB, RC are provided on the main surface 5 a facing the liquid crystal panel 2. It is provided along the longitudinal direction (x-axis direction in FIG. 1). In each light extraction region RA, RB, RC, low refractive index bodies 8a, 8b, a refractive index body 9, and a light scattering body 10 are stacked in this order. The low refractive index bodies 8 a and 8 b have a refractive index lower than that of the light guide 5. The refractive index body 9 has a refractive index equal to the refractive index of the light guide 5. The light scatterer 10 scatters the light emitted from the low refractive index bodies 8 a and 8 b and the refractive index body 9. In the following description, for the sake of convenience, the respective light extraction regions are directed from the side closer to the light emitting elements 7a, 7b, 7c to the side farther from the first light extraction region RA, the second light extraction region RB, and the third light extraction. This is referred to as region RC. In addition, the main surface of the light guide 5 provided with the light extraction regions RA, RB, RC is the first main surface 5a, the main surface opposite to the first main surface 5a is the second main surface 5b, and the light emitting element 7a, The end surface of the light guide 5 provided with 7b and 7c is referred to as a first end surface 5c, and the end surface opposite to the first end surface 5c is referred to as a second end surface 5d.
　上述したように、低屈折率体８ａ，８ｂは、いずれも導光体５の屈折率よりも低い屈折率を有し、屈折率体９は、導光体５の屈折率と等しい屈折率を有している。低屈折率体８ａ，８ｂおよび屈折率体９はそれぞれ異なる屈折率を有している。また、低屈折率体８ａ，８ｂおよび屈折率体９は、各発光素子７ａ，７ｂ，７ｃから射出されて各光取出領域ＲＡ，ＲＢ，ＲＣに入射される光の伝播方向に沿って（図１の－ｘ方向から＋ｘ方向に向けて）、屈折率が相対的に低いものから屈折率が相対的に高いものの順に配列されている。
　本実施形態の一例として、導光体５の屈折率ｎＷＧが１．５であるのに対し、第１光取出領域ＲＡに設けられた第１低屈折率体８ａの屈折率ｎＡが１．３、第２光取出領域ＲＢに設けられた第２低屈折率体８ｂの屈折率ｎＢが１．４、第３光取出領域ＲＣに設けられた屈折率体９の屈折率ｎＣが１．５に設定されている。 As described above, the low refractive index bodies 8 a and 8 b both have a refractive index lower than that of the light guide 5, and the refractive index body 9 has a refractive index equal to the refractive index of the light guide 5. Have. The low refractive index bodies 8a and 8b and the refractive index body 9 have different refractive indexes. Further, the low refractive index bodies 8a and 8b and the refractive index body 9 are arranged along the propagation direction of light emitted from the light emitting elements 7a, 7b and 7c and incident on the light extraction regions RA, RB and RC (FIG. 1 from the −x direction to the + x direction), the refractive index is relatively low, and the refractive index is relatively high.
As an example of this embodiment, the refractive index nWG of the light guide 5 is 1.5, whereas the refractive index nA of the first low refractive index body 8a provided in the first light extraction region RA is 1.3. The refractive index nB of the second low refractive index body 8b provided in the second light extraction region RB is 1.4, and the refractive index nC of the refractive index body 9 provided in the third light extraction region RC is 1.5. Is set.
　屈折率が異なる低屈折率体８ａ，８ｂおよび屈折率体９を形成する手法としては、例えば以下の２つの手法を挙げることができる。
　第１の手法は、異なる材料を用いて低屈折率体８ａ，８ｂおよび屈折率体９を形成することである。例えば導光体５の材料としてアクリル樹脂を用い、第１低屈折率体８ａの材料としてデュポン社製の非晶性フッ素樹脂「ＡＦ１６００」（登録商標、屈折率：ｎＡ＝１．２９～１．３１）、第２低屈折率体８ｂの材料としてＤＩＣ社製の紫外線硬化樹脂「ＯＰ４０」（登録商標、屈折率：ｎＢ＝１．４０３）、屈折率体９の材料としてクラレ社製のメタクリル樹脂「パラペット（光学グレード）」（登録商標、屈折率：ｎＣ＝１．４９）の各液状体を導光体５上に選択的に塗布し、硬化させることで実現できる。
　なお、屈折率体９は導光体５と等しい屈折率を有しているため、導光体５上に必ずしも屈折率体９を形成する必要はない。例えば、導光体５上に光散乱体１０が配置されているだけでも良い。 As a method of forming the low refractive index bodies 8a and 8b and the refractive index body 9 having different refractive indexes, for example, the following two methods can be cited.
The first method is to form the low refractive index bodies 8a and 8b and the refractive index body 9 using different materials. For example, an acrylic resin is used as the material of the light guide 5, and an amorphous fluororesin “AF1600” (registered trademark, refractive index: n A = 1.29 to 1) manufactured by DuPont is used as the material of the first low refractive index body 8 a. .31), UV curing resin “OP40” (registered trademark, refractive index: n B = 1.403) manufactured by DIC as the material of the second low refractive index body 8b, and Kuraray Co., Ltd. as the material of the refractive index body 9. Each liquid material of methacrylic resin “parapet (optical grade)” (registered trademark, refractive index: n C = 1.49) is selectively applied onto the light guide 5 and cured.
Since the refractive index body 9 has the same refractive index as that of the light guide 5, it is not always necessary to form the refractive index body 9 on the light guide 5. For example, the light scatterer 10 may be merely disposed on the light guide 5.
　第２の手法は、所定の基材中に低屈折率材料を含有させた材料を用い、低屈折率材料の濃度を異ならせて屈折率を調整することである。例えば、上記の屈折率体９の材料として用いたクラレ社製のメタクリル樹脂「パラペット（光学グレード）」（登録商標、屈折率：ｎＣ＝１．４９）中に、Ａｒｄｒｉｃｈ社製のメゾポーラスシリカナノパウダー（登録商標、屈折率：１．２７）、もしくはＪａｓｏｎ　Ｗｅｌｌｓ社製のエアロゲル（登録商標、屈折率：１．２７）等の低屈折率材料を含有させ、これら低屈折率材料の濃度を異ならせた２種類の液状体を作製する。そして、各液状体を導光体５上に選択的に塗布し、硬化させることで実現できる。 The second technique is to use a material containing a low refractive index material in a predetermined substrate and adjust the refractive index by varying the concentration of the low refractive index material. For example, in the methacrylic resin “Parapet (Optical Grade)” (registered trademark, refractive index: n C = 1.49) manufactured by Kuraray Co., Ltd. used as the material of the refractive index body 9, the mesoporous silica nanometer manufactured by Ardrich is used. Low refractive index materials such as powder (registered trademark, refractive index: 1.27) or airgel (registered trademark, refractive index: 1.27) manufactured by Jason Wells are included, and the concentration of these low refractive index materials is different. Two types of liquids are prepared. Each liquid material can be selectively applied on the light guide 5 and cured.
　低屈折率体８ａ，８ｂおよび屈折率体９上には光散乱体１０が積層されている。光散乱体１０は、低屈折率体８ａ，８ｂおよび屈折率体９から入射された光を散乱させてバックライト３の外部空間に取り出す機能を有している。具体的には、光散乱体１０としては、ベースフィルム上に散乱ビーズ等がコーティングされた市販の光散乱フィルムを使用することができる。低屈折率体８ａ，８ｂおよび屈折率体９上に光散乱フィルムを貼付することで光散乱体１０を形成することができる。本実施形態の光散乱体１０としては、光散乱能の高い光散乱フィルムを用いることが望ましい。 A light scatterer 10 is laminated on the low refractive index bodies 8 a and 8 b and the refractive index body 9. The light scatterer 10 has a function of scattering the light incident from the low refractive index bodies 8 a and 8 b and the refractive index body 9 and extracting the light to the external space of the backlight 3. Specifically, as the light scatterer 10, a commercially available light scattering film in which scattering beads or the like are coated on a base film can be used. The light scattering body 10 can be formed by sticking a light scattering film on the low refractive index bodies 8 a and 8 b and the refractive index body 9. As the light scatterer 10 of this embodiment, it is desirable to use a light scattering film with high light scattering ability.
　図１に示すように、各バックライトユニット４において、導光体５の第１端面５ｃは第１主面５ａに対する角度が互いに等しい直角面となっている。導光体５の第１端面５ｃには、発光素子７ａ，７ｂ，７ｃが光学接着剤を介して固定されている。したがって、第１端面５ｃの全体では、３個の発光素子７ａ，７ｂ，７ｃが導光体５の短手方向に並べられている。 As shown in FIG. 1, in each backlight unit 4, the first end surface 5 c of the light guide 5 is a right-angle surface having the same angle with respect to the first main surface 5 a. Light emitting elements 7a, 7b, 7c are fixed to the first end surface 5c of the light guide 5 via an optical adhesive. Therefore, three light emitting elements 7 a, 7 b, 7 c are arranged in the short direction of the light guide 5 over the entire first end face 5 c.
　このような構成により、光源７３から射出された光の大部分は、凹面ミラー７２に直接入射する。一方、残りの凹面ミラー７２と異なる方向に射出された光源７３からの光は、反射ミラー７４で反射されて凹面ミラー７２に入射する。凹面ミラー７２に入射した光は、凹面ミラー７２によって取付面７１ｂに向けて反射される。なお、光源７３は凹面ミラー７２の焦点Ｐｃに配置されているため、凹面ミラー７２で反射された光は平行化される。そして、凹面ミラー７２で平行化された光は、光透過部材７５を伝播して、取付面７１ｂから取り出される。本実施形態では、光透過部材７５の光射出面が取付面となる。 With such a configuration, most of the light emitted from the light source 73 is directly incident on the concave mirror 72. On the other hand, light from the light source 73 emitted in a different direction from the remaining concave mirror 72 is reflected by the reflection mirror 74 and enters the concave mirror 72. The light incident on the concave mirror 72 is reflected by the concave mirror 72 toward the mounting surface 71b. Since the light source 73 is disposed at the focal point Pc of the concave mirror 72, the light reflected by the concave mirror 72 is collimated. The light collimated by the concave mirror 72 propagates through the light transmitting member 75 and is extracted from the mounting surface 71b. In the present embodiment, the light emission surface of the light transmitting member 75 is the mounting surface.
　なお、以下の説明では、便宜上、第１端面５ｃに設けられた３つの発光素子７ａ，７ｂ，７ｃのうち、凹面ミラー７２の中心軸ＣＬ１と取付面７１ｂの法線ＣＬ２とのなす角度が最も大きい発光素子（図１の右側）を第１発光素子７ａ（θ１＝３７°）と称する。また、凹面ミラー７２の中心軸ＣＬ１と取付面７１ｂの法線ＣＬ２とのなす角度が次に大きい発光素子（図１の中央）を第２発光素子７ｂ（θ２＝２６°）と称する。凹面ミラー７２の中心軸ＣＬ１と取付面７１ｂの法線ＣＬ２とのなす角度が最も小さい発光素子（図１の左側）を第３発光素子７ｃ（θ３＝１５°）、と称する。 In the following description, for the sake of convenience, of the three light emitting elements 7a, 7b, 7c provided on the first end surface 5c, the angle formed by the central axis CL1 of the concave mirror 72 and the normal line CL2 of the mounting surface 71b is the largest. A large light emitting element (right side in FIG. 1) is referred to as a first light emitting element 7a (θ1 = 37 °). The light emitting element (center in FIG. 1) having the next largest angle between the central axis CL1 of the concave mirror 72 and the normal line CL2 of the mounting surface 71b is referred to as a second light emitting element 7b (θ2 = 26 °). The light emitting element (left side in FIG. 1) having the smallest angle formed by the central axis CL1 of the concave mirror 72 and the normal line CL2 of the mounting surface 71b is referred to as a third light emitting element 7c (θ3 = 15 °).
　図２Ａは図１のＡ－Ａ’線に沿う断面図を示している。図２Ｂは図１のＢ－Ｂ’線に沿う断面図を示している。図２Ｃは図１のＣ－Ｃ’線に沿う断面図を示している。各発光素子７ａ，７ｂ，７ｃは第１端面５ｃに対して斜めに光Ｌａ，Ｌｂ，Ｌｃが入射するように固定されている。各発光素子７ａ，７ｂ，７ｃから射出された光Ｌａ，Ｌｂ，Ｌｃは、導光体５の第１主面５ａと第２主面５ｂとの間で全反射を繰り返しつつ、第１端面５ｃ側から第２端面５ｄ側に向けて伝播される。 FIG. 2A is a sectional view taken along the line A-A ′ of FIG. FIG. 2B shows a cross-sectional view along the line B-B ′ of FIG. 1. FIG. 2C shows a cross-sectional view taken along the line C-C 'of FIG. Each light emitting element 7a, 7b, 7c is fixed so that the light La, Lb, Lc is incident on the first end face 5c obliquely. The light La, Lb, Lc emitted from each light emitting element 7a, 7b, 7c repeats total reflection between the first main surface 5a and the second main surface 5b of the light guide 5, and the first end surface 5c. Is propagated from the side toward the second end face 5d.
　ここで、導光板の厚さ方向の中心を通る仮想水平面に対する光軸のなす角度を伝播角度φと定義する。すると、光透過部材７５の屈折率は、導光体５の屈折率ｎＷＧ（１．５）と同じ値の１．５に設定されていることから、伝播角度φは傾斜角度θと等しくなる。そのため、図２Ａに示すように、第１発光素子７ａからの光Ｌａの伝播角度φＡは３７°となる。図２Ｂに示すように、第２発光素子７ｂからの光Ｌｂの伝播角度φＢは２６°となる。図２Ｃに示すように、第３発光素子７ｃからの光Ｌｃの伝播角度φＣは１５°となる。よって、各光Ｌａ，Ｌｂ，Ｌｃは、第１端面５ｃ側から第２端面５ｄ側に向けて伝播される間、第１光取出領域ＲＡ、第２光取出領域ＲＢ、第３光取出領域ＲＣの順に、各光取出領域ＲＡ，ＲＢ，ＲＣに入射する。 Here, an angle formed by the optical axis with respect to a virtual horizontal plane passing through the center in the thickness direction of the light guide plate is defined as a propagation angle φ. Then, since the refractive index of the light transmission member 75 is set to 1.5, which is the same value as the refractive index nWG (1.5) of the light guide 5, the propagation angle φ is equal to the inclination angle θ. Therefore, as shown in FIG. 2A, the propagation angle phi A of the light La from the first light emitting element 7a becomes 37 °. As shown in Figure 2B, propagation angle phi B light Lb from the second light emitting element 7b becomes 26 °. As shown in FIG. 2C, propagation angle phi C of the light Lc from the third light-emitting element 7c becomes 15 °. Therefore, while each light La, Lb, Lc is propagated from the first end face 5c side toward the second end face 5d side, the first light extraction area RA, the second light extraction area RB, and the third light extraction area RC. In this order, the light enters the light extraction areas RA, RB, RC.
　なお、図２Ａ～２Ｃでは、図面を見やすくするため、導光体５の長手方向の寸法（ｘ軸方向の寸法）に対して厚み（ｚ軸方向の寸法）を十分大きく描いている。また、各発光素子７ａ，７ｂ，７ｃから射出される光の中心軸のみを描いている。そのため、光が各光取出領域ＲＡ，ＲＢ，ＲＣに必ずしも入射しない場合もあるように思えるが、実際には導光体５の長手方向の寸法に対して厚みが十分に小さく、各発光素子７ａ，７ｂ，７ｃからの光Ｌａ，Ｌｂ，Ｌｃは有限の光束径を有しているため、光Ｌａ，Ｌｂ，Ｌｃは各光取出領域ＲＡ，ＲＢ，ＲＣに確実に入射する。 2A to 2C, the thickness (dimension in the z-axis direction) is drawn sufficiently larger than the longitudinal dimension (dimension in the x-axis direction) of the light guide 5 for easy viewing. Further, only the central axis of the light emitted from each light emitting element 7a, 7b, 7c is drawn. For this reason, it may seem that the light does not necessarily enter each of the light extraction regions RA, RB, RC, but actually the thickness is sufficiently small with respect to the longitudinal dimension of the light guide 5 and each light emitting element 7a. , 7b, 7c have a finite beam diameter, so that the light La, Lb, Lc is reliably incident on each of the light extraction areas RA, RB, RC.
　すなわち、本実施形態の照明部６は、３個の発光素子７ａ，７ｂ，７ｃを備えており、各発光素子７ａ，７ｂ，７ｃからの光Ｌａ，Ｌｂ，Ｌｃを、各光取出領域ＲＡ，ＲＢ，ＲＣから光Ｌａ，Ｌｂ，Ｌｃを取り出し可能な入射角を含む入射角で各光取出領域ＲＡ，ＲＢ，ＲＣに入射させる。また、後述するが、照明部６は、１つの光取出領域ＲＡ，ＲＢ，ＲＣに対して３種類の異なる入射角θ（θＡ＝５３°、θＢ＝６４°、θＣ＝７５°）で入射させるように、いずれの発光素子７ａ，７ｂ，７ｃを点灯させるかを切り換えることにより、導光体５の内部における光の伝播角度φ（φＡ＝３７°、φＢ＝２６°、φＣ＝１５°）を切り換える機能を有している。 That is, the illuminating unit 6 of the present embodiment includes three light emitting elements 7a, 7b, and 7c. Lights La, Lb, and Lc from the light emitting elements 7a, 7b, and 7c are converted into the light extraction regions RA, Lights La, Lb, and Lc are extracted from RB and RC and are incident on the light extraction regions RA, RB, and RC at an incident angle including an incident angle at which the light can be extracted. As will be described later, the illumination unit 6 has three different incident angles θ (θ A = 53 °, θ B = 64 °, θ C = 75 °) with respect to one light extraction region RA, RB, RC. The light propagation angle φ (φ A = 37 °, φ B = 26 °, φ inside the light guide 5 is switched by switching which light emitting element 7a, 7b, 7c is lit. C = 15 °).
　ここで、各発光素子７ａ，７ｂ，７ｃからの光Ｌａ，Ｌｂ，Ｌｃが、各光取出領域ＲＡ，ＲＢ，ＲＣにおける導光体５と各低屈折率体８ａ，８ｂおよび屈折率体９との界面に入射する際の臨界角を考慮する。
　第１光取出領域ＲＡでの導光体５と第１低屈折率体との界面は、屈折率ｎＷＧ＝１．５の導光体と屈折率ｎＡ＝１．３の第１低屈折率体８ａとの界面となるので、Ｓｎｅｌｌの法則より、臨界角γＡは６０．１°となる。したがって、第１光取出領域ＲＡでは、入射角が６０．１°未満で入射した光は界面を透過し、入射角が６０．１°以上で入射した光は界面で全反射する。同様に、第２光取出領域ＲＢでの導光体５と第２低屈折率体８ｂとの界面は、屈折率ｎＷＧ＝１．５の導光体５と屈折率ｎＢ＝１．４の第２低屈折率体８ｂとの界面となるので、臨界角γＢは６９．０°となる。したがって、第２光取出領域ＲＢでは、入射角が６９．０°未満で入射した光は界面を透過し、入射角が６９．０°以上で入射した光は界面で全反射する。これに対して、第３光取出領域ＲＣでの導光体５と屈折率体９との界面は、屈折率ｎＷＧ＝１．５の導光体と屈折率ｎＣ＝１．５の屈折率体９との界面となるので、全ての入射角において光は界面を透過する。 Here, the light La, Lb, and Lc from each light emitting element 7a, 7b, and 7c are the light guide 5 in each light extraction area | region RA, RB, RC, each low refractive index body 8a, 8b, and the refractive index body 9, Consider the critical angle when entering the interface.
The interface between the light guide 5 and the first low refractive index body in the first light extraction region RA is the first low refraction with the refractive index n WG = 1.5 and the refractive index n A = 1.3. Since it becomes an interface with the rate body 8a, the critical angle γ A is 60.1 ° according to Snell's law. Therefore, in the first light extraction region RA, light incident at an incident angle of less than 60.1 ° is transmitted through the interface, and light incident at an incident angle of 60.1 ° or more is totally reflected at the interface. Similarly, the interface between the light guide 5 and the second low refractive index body 8b in the second light extraction region RB is the light guide 5 having a refractive index n WG = 1.5 and a refractive index n B = 1.4. Therefore, the critical angle γ B is 69.0 °. Therefore, in the second light extraction region RB, light incident at an incident angle of less than 69.0 ° is transmitted through the interface, and light incident at an incident angle of 69.0 ° or greater is totally reflected at the interface. On the other hand, the interface between the light guide 5 and the refractive index body 9 in the third light extraction region RC is a refraction having a refractive index n WG = 1.5 and a refractive index n C = 1.5. Since it becomes an interface with the index body 9, light passes through the interface at all incident angles.
　すなわち、第１光取出領域ＲＡ、第２光取出領域ＲＢ、第３光取出領域ＲＣを単独で見た場合には、第１光取出領域ＲＡで光を外部に取り出し可能な入射角範囲は６０．１°未満、第２光取出領域ＲＢで光を外部に取り出し可能な入射角範囲は６９．０°未満、第３光取出領域ＲＣで光を外部に取り出し可能な入射角範囲は全ての角度範囲となる。 That is, when the first light extraction area RA, the second light extraction area RB, and the third light extraction area RC are viewed independently, the incident angle range in which light can be extracted outside in the first light extraction area RA is 60. Less than 1 °, the incident angle range in which light can be extracted outside in the second light extraction region RB is less than 69.0 °, and the incident angle range in which light can be extracted outside in the third light extraction region RC is all angles. It becomes a range.
　このように、本実施形態の３つの光取出領域ＲＡ，ＲＢ，ＲＣに設けられた２つの低屈折率体８ａ，８ｂおよび屈折率体９は、光取出領域ＲＡ，ＲＢ，ＲＣに入射される光の伝播方向に沿って、屈折率が相対的に低いものから屈折率が相対的に高いものの順に配列されている。このような屈折率の違いに基づき、３つの光取出領域ＲＡ，ＲＢ，ＲＣは、光を外部に取り出し可能な入射角範囲が異なっている。さらに、３つの光取出領域ＲＡ，ＲＢ，ＲＣは、入射される光の伝播方向に沿って、取り出し可能な入射角範囲が相対的に狭い光取出領域から取り出し可能な入射角範囲が相対的に広い光取出領域の順に配列されている。本実施形態においては、第１光取出領域ＲＡでの取出可能な入射角範囲は６０．１°未満であり、第２光取出領域ＲＢでの取出可能な入射角範囲は６９．０°未満であり、第３光取出領域ＲＣでの取出可能な入射角範囲は全角度範囲である。 As described above, the two low refractive index bodies 8a and 8b and the refractive index body 9 provided in the three light extraction regions RA, RB, and RC of the present embodiment are incident on the light extraction regions RA, RB, and RC. Along the light propagation direction, the light is arranged in the order of relatively low refractive index to relatively high refractive index. Based on such a difference in refractive index, the three light extraction regions RA, RB, and RC have different incident angle ranges in which light can be extracted to the outside. Further, the three light extraction areas RA, RB, and RC have a relatively narrow incident angle range that can be extracted from a light extraction area that has a relatively narrow incident angle range along the propagation direction of incident light. They are arranged in the order of wide light extraction areas. In the present embodiment, the incident angle range that can be extracted in the first light extraction region RA is less than 60.1 °, and the incident angle range that can be extracted in the second light extraction region RB is less than 69.0 °. The incident angle range that can be extracted in the third light extraction region RC is the entire angle range.
　このとき、図２Ａに示すように、第１端面５ｃに固定された第１発光素子７ａを点灯させたとすると、第１発光素子７ａからの光Ｌａは第１端面５ｃに対して斜めに入射し伝播角度φＡ＝３７°で導光体５を伝播するため、第１発光素子７ａからの光Ｌａの第１主面５ａに対する入射角θＡは５３°となる。また、本実施形態の導光体５は平行平板で構成されているため、第１発光素子７ａからの光Ｌａが何回全反射を繰り返しても、第１主面５ａに対する入射角θＡは常に５３°である。第１発光素子７ａからの光Ｌａが第１光取出領域ＲＡに到達し、導光体５と第１低屈折率体８ａとの界面に対して入射角θＡ＝５３°で入射すると、ここでの臨界角γＡは６０．１°であるから、光Ｌａは導光体５と第１低屈折率体８ａとの界面を透過して第１低屈折率体８ａに入射される。その後、光散乱体１０で散乱して外部に取り出される。このようにして、第１発光素子７ａから射出された光Ｌａの略全量を第１光取出領域ＲＡから取り出すことができる。 At this time, as shown in FIG. 2A, if the first light emitting element 7a fixed to the first end face 5c is turned on, the light La from the first light emitting element 7a is obliquely incident on the first end face 5c. Since the light propagates through the light guide 5 at the propagation angle φ A = 37 °, the incident angle θ A of the light La from the first light emitting element 7a with respect to the first major surface 5a is 53 °. In addition, since the light guide 5 of the present embodiment is configured by parallel plates, the incident angle θ A with respect to the first major surface 5a is no matter how many times the light La from the first light emitting element 7a repeats total reflection. Always 53 °. When the light La from the first light emitting element 7a reaches the first light extraction region RA and enters the interface between the light guide 5 and the first low refractive index body 8a at an incident angle θ A = 53 °, Since the critical angle γ A at 6 is 60.1 °, the light La passes through the interface between the light guide 5 and the first low refractive index body 8a and enters the first low refractive index body 8a. Thereafter, the light is scattered by the light scatterer 10 and taken out to the outside. In this way, substantially the entire amount of the light La emitted from the first light emitting element 7a can be extracted from the first light extraction region RA.
　次に、図２Ｂに示すように、第１発光素子７ａを消灯させ、第１端面５ｃに固定された第２発光素子７ｂを点灯させたとすると、第２発光素子７ｂからの光Ｌｂは第１端面５ｃに対して斜めに入射し伝播角度φＢ＝２６°で導光体５を伝播するため、第２発光素子７ｂからの光Ｌｂの第１主面５ａに対する入射角θＢは６４°となる。第２発光素子７ｂからの光Ｌｂが第１光取出領域ＲＡに到達し、導光体５と第１低屈折率体８ａとの界面に対して入射角θＢ＝６４°で入射する。ここでの臨界角γＡは６０．１°であるから、光Ｌｂは導光体５と第１低屈折率体８ａとの界面を透過できず、全反射する。次に、第２発光素子７ｂからの光Ｌｂが第２光取出領域ＲＢに到達し、導光体５と第２低屈折率体８ｂとの界面に対して入射角θＢ＝６４°で入射する。ここでの臨界角γＢは６９．０°であるから、光Ｌｂは導光体５と第２低屈折率体８ｂとの界面を透過して第２低屈折率体８ｂに入射され、その後、光散乱体１０から外部に取り出される。このようにして、第２発光素子７ｂから射出された光Ｌｂの略全量を第２光取出領域ＲＢから取り出すことができる。 Next, as shown in FIG. 2B, when the first light emitting element 7a is turned off and the second light emitting element 7b fixed to the first end face 5c is turned on, the light Lb from the second light emitting element 7b is the first light Lb. Since the light is incident on the end surface 5c obliquely and propagates through the light guide 5 at the propagation angle φ B = 26 °, the incident angle θ B of the light Lb from the second light emitting element 7b to the first main surface 5a is 64 °. Become. The light Lb from the second light emitting element 7b reaches the first light extraction region RA, and enters the interface between the light guide 5 and the first low refractive index body 8a at an incident angle θ B = 64 °. Since the critical angle γ A here is 60.1 °, the light Lb cannot be transmitted through the interface between the light guide 5 and the first low refractive index body 8a, and is totally reflected. Next, the light Lb from the second light emitting element 7b reaches the second light extraction region RB and is incident at an incident angle θ B = 64 ° with respect to the interface between the light guide 5 and the second low refractive index body 8b. To do. Since the critical angle γ B here is 69.0 °, the light Lb passes through the interface between the light guide 5 and the second low refractive index body 8b and is incident on the second low refractive index body 8b. , Extracted from the light scatterer 10 to the outside. In this way, substantially the entire amount of the light Lb emitted from the second light emitting element 7b can be extracted from the second light extraction region RB.
　仮に第１発光素子７ａから射出された光Ｌａが第２光取出領域ＲＢに入射したとすると、この場合も入射角が臨界角よりも小さいという条件を満たすため、この光Ｌａを第２光取出領域ＲＢから取り出すことができる。しかしながら、第１発光素子７ａから射出された光Ｌａは第２光取出領域ＲＢに到達する前に第１光取出領域ＲＡで略全量が取り出されてしまうため、ほとんど第２光取出領域ＲＢに到達することがない。したがって、実際には第１発光素子７ａから射出された光Ｌａが第２光取出領域ＲＢから取り出されることはなく、第２発光素子７ｂから射出された光Ｌｂが第２光取出領域ＲＢから取り出されることになる。本実施形態のバックライト３は、このような原理に基づいて所定のＬＥＤから射出された光を所定の光取出領域のみから取り出すことができる。 If the light La emitted from the first light emitting element 7a is incident on the second light extraction region RB, this condition also satisfies the condition that the incident angle is smaller than the critical angle. It can be taken out from the region RB. However, almost all of the light La emitted from the first light emitting element 7a is extracted in the first light extraction area RA before reaching the second light extraction area RB, and thus almost reaches the second light extraction area RB. There is nothing to do. Therefore, actually, the light La emitted from the first light emitting element 7a is not extracted from the second light extraction region RB, and the light Lb emitted from the second light emitting element 7b is extracted from the second light extraction region RB. Will be. Based on such a principle, the backlight 3 of the present embodiment can extract light emitted from a predetermined LED only from a predetermined light extraction area.
　次に、図２Ｃに示すように、第２発光素子７ｂを消灯させ、第１端面５ｃに固定された第３発光素子７ｃを点灯させたとすると、第３発光素子７ｃからの光Ｌｃは第１端面５ｃに対して斜めに入射し伝播角度φＣ＝１５°で導光体５を伝播する。そのため、第３発光素子７ｃからの光Ｌｃの第１主面５ａに対する入射角θＣは７５°となる。第３発光素子７ｃからの光Ｌｃが第１光取出領域ＲＡもしくは第２光取出領域ＲＢに到達し、導光体５と第１低屈折率体８ａもしくは第２低屈折率体８ｂとの界面に対して入射角θＣ＝７５°で入射すると、この入射角θＣは臨界角γＡおよび臨界角γＢよりも大きいため、光Ｌｃは各界面を透過できず、全反射する。その後、第３発光素子７ｃからの光Ｌｃが第３光取出領域ＲＣに到達すると、光Ｌｃは導光体５と屈折率体９との界面を透過して屈折率体９に入射され、その後、光散乱体１０から外部に取り出される。
　このようにして、第３発光素子７ｃから射出された光Ｌｃの略全量を第３光取出領域ＲＣから取り出すことができる。 Next, as shown in FIG. 2C, when the second light emitting element 7b is turned off and the third light emitting element 7c fixed to the first end face 5c is turned on, the light Lc from the third light emitting element 7c is the first light Lc. The light is incident on the end face 5c obliquely and propagates through the light guide 5 at a propagation angle φ C = 15 °. Therefore, the incident angle θ C of the light Lc from the third light emitting element 7c with respect to the first major surface 5a is 75 °. The light Lc from the third light emitting element 7c reaches the first light extraction region RA or the second light extraction region RB, and the interface between the light guide 5 and the first low refractive index body 8a or the second low refractive index body 8b. Is incident at an incident angle θ C = 75 °, the incident angle θ C is larger than the critical angle γ A and the critical angle γ B , so that the light Lc cannot be transmitted through each interface and is totally reflected. Thereafter, when the light Lc from the third light emitting element 7c reaches the third light extraction region RC, the light Lc passes through the interface between the light guide 5 and the refractive index body 9 and is incident on the refractive index body 9, and thereafter , Extracted from the light scatterer 10 to the outside.
In this way, substantially the entire amount of the light Lc emitted from the third light emitting element 7c can be extracted from the third light extraction region RC.
　上述したように、本実施形態のバックライト３によれば、各バックライトユニット４の３個の発光素子７ａ，７ｂ，７ｃのうちのいずれのＬＥＤを点灯させるかによって、３つの光取出領域ＲＡ，ＲＢ，ＲＣのうちのいずれの光取出領域から光を取り出すか、すなわち、いずれの光取出領域ＲＡ，ＲＢ，ＲＣを発光させるかを適宜選択することができる。
　また、各発光素子７ａ，７ｂ，７ｃから射出される光の量を制御することにより、選択された光取出領域ＲＡ，ＲＢ，ＲＣから取り出す光の量、すなわち、選択された光取出領域の明るさを調整することができる。 As described above, according to the backlight 3 of the present embodiment, the three light extraction areas RA are determined depending on which of the three light emitting elements 7a, 7b, and 7c of the backlight unit 4 is lit. , RB, and RC, the light extraction area from which light is extracted, that is, which light extraction area RA, RB, RC is allowed to emit light can be appropriately selected.
Further, by controlling the amount of light emitted from each light emitting element 7a, 7b, 7c, the amount of light extracted from the selected light extraction regions RA, RB, RC, that is, the brightness of the selected light extraction region. Can be adjusted.
　本実施形態の発光素子７ａにおいては、光源７３が凹面ミラー７２の焦点Ｐｆに配置されているため、光源７３から射出されて凹面ミラー７２で反射された光は平行化される。
　凹面ミラー７２によって平行化された光は、パッケージ７１の取付面７１ｂから射出される。よって、パッケージ７１の取付面７１ｂから指向性の高い光を取り出すことができる。 In the light emitting element 7a of the present embodiment, since the light source 73 is disposed at the focal point Pf of the concave mirror 72, the light emitted from the light source 73 and reflected by the concave mirror 72 is collimated.
The light collimated by the concave mirror 72 is emitted from the mounting surface 71 b of the package 71. Therefore, light with high directivity can be extracted from the mounting surface 71 b of the package 71.
　従来の発光素子では、指向性を持った光を取り出すことはできるものの、光をＬＥＤ実装基板の法線に対して斜め方向に取り出すことはできなかった。例えば、発光素子を対象物の一面（例えば導光板の端面など、発光素子が取り付けられる面）に取り付けた場合、光を対象物の一面の法線に対して斜め方向に取り出すことはできなかった。これに対して、本実施形態の発光素子７ａは、凹面ミラー７２の中心軸ＣＬ１がパッケージ７１の取付面７１ｂの法線ＣＬ２と斜めに交差しているので、光を対象物の一面の法線に対して斜め方向に取り出すことができる。
　したがって、本実施形態の発光素子７ａによれば、指向性の高い光を対象物の一面の法線に対して斜め方向に取り出すことが可能となる。
　また、光を対象物の一面の法線に対して斜め方向に取り出すために、対象物の一面を斜めにカットする必要がない。したがって、対象物の形状がシンプルとなり、加工に手間がかからなくなる。 In the conventional light emitting device, although light having directivity can be extracted, the light cannot be extracted in an oblique direction with respect to the normal line of the LED mounting substrate. For example, when a light-emitting element is attached to one surface of an object (for example, a surface on which a light-emitting element is attached, such as an end face of a light guide plate), light cannot be extracted in an oblique direction with respect to the normal of the one surface of the object . On the other hand, in the light emitting element 7a of the present embodiment, since the central axis CL1 of the concave mirror 72 obliquely intersects the normal line CL2 of the mounting surface 71b of the package 71, the light is normal to one surface of the object. Can be taken out obliquely.
Therefore, according to the light emitting element 7a of the present embodiment, light with high directivity can be extracted in an oblique direction with respect to the normal line of one surface of the object.
In addition, in order to extract light in an oblique direction with respect to the normal of one surface of the object, it is not necessary to cut one surface of the object obliquely. Therefore, the shape of the object becomes simple, and processing is not time-consuming.
　また、凹面ミラー７２の中心軸ＣＬ１が光源７３の光射出面の法線と一致している。そのため、凹面ミラー７２の中心軸ＣＬ１が光源７３の光射出面の法線とずれている場合に比べて、光源７３から射出された光を効率良く取り出すことができる。 Also, the central axis CL1 of the concave mirror 72 coincides with the normal line of the light exit surface of the light source 73. Therefore, the light emitted from the light source 73 can be extracted more efficiently than when the central axis CL1 of the concave mirror 72 is deviated from the normal line of the light emission surface of the light source 73.
　また、凹面ミラー７２が放物面ミラーであり、光源７３が凹面ミラー７２の焦点Ｐｆに配置されているので、光源７３から射出された光を十分に平行化して取り出すことができる。したがって、指向性の高い光を取り出すことが容易となる。 Further, since the concave mirror 72 is a parabolic mirror and the light source 73 is disposed at the focal point Pf of the concave mirror 72, the light emitted from the light source 73 can be sufficiently collimated and extracted. Therefore, it becomes easy to extract light with high directivity.
　また、光源７３の凹面ミラー７２が配置された側と反対の側に反射ミラー７４が設けられている。そのため、反射ミラー７４によって、光源７３の凹面ミラー７２が配置された側と反対の側から射出された光（凹面ミラー７２に直接入射されない光源７３からの光）は凹面ミラー７２に向けて反射される。仮に、反射ミラー７４が設けられていない構成であると、光源７３の凹面ミラー７２が配置された側と反対の側から射出された光は、凹面ミラー７２で反射されることなく、パッケージ７１の取付面７１ｂから平行化されていない光がそのまま取り出されることとなる。したがって、反射ミラー７４を設けることによって、指向性の高い光を確実に取り出すことができる。 Further, a reflection mirror 74 is provided on the side opposite to the side where the concave mirror 72 of the light source 73 is disposed. Therefore, light reflected from the side opposite to the side where the concave mirror 72 of the light source 73 is disposed (light from the light source 73 not directly incident on the concave mirror 72) is reflected toward the concave mirror 72 by the reflection mirror 74. The If the configuration is such that the reflection mirror 74 is not provided, the light emitted from the side opposite to the side where the concave mirror 72 of the light source 73 is disposed is not reflected by the concave mirror 72, and the package 71 The light that has not been collimated is extracted as it is from the mounting surface 71b. Therefore, by providing the reflecting mirror 74, light with high directivity can be reliably extracted.
　また、光源７３がパッケージ７１の凹部７１ａに光透過部材７５によって埋設されているので、光源７３の位置および姿勢を安定して保持することができる。例えば、発光素子７ａが外部から衝撃を受けた場合に、光源７３の位置がずれたり光源７３の姿勢が傾いたりすること（光源７３が焦点Ｐｆからずれたり、光源７３の光射出面の法線が凹面ミラー７２の中心軸ＣＬ１とずれたりすること）を抑制することができる。 Further, since the light source 73 is embedded in the recess 71a of the package 71 by the light transmitting member 75, the position and posture of the light source 73 can be stably held. For example, when the light emitting element 7a receives an impact from the outside, the position of the light source 73 is shifted or the posture of the light source 73 is inclined (the light source 73 is shifted from the focal point Pf, or the normal line of the light emission surface of the light source 73). Can be prevented from deviating from the central axis CL1 of the concave mirror 72).
　なお、本実施形態の発光素子７ａでは、光源７３の凹面ミラー７２が配置された側と反対の側に反射ミラー７４が設けられている構成を例示して説明したが、これに限らない。
　例えば、光源の凹面ミラーが配置された側と反対の側には、凹面ミラーと異なる方向に射出された光源からの光を凹面ミラーによって平行化された光の進行方向と同じ方向に向けて平行化する平行化レンズが設けられていても良い。この構成によれば、光源の凹面ミラーが配置された側と反対の側から射出された光（凹面ミラーに直接入射されない光源からの光）が平行化レンズによって平行化されて、パッケージの取付面から平行化された光が取り出される。したがって、反射ミラーに替えて平行化レンズを設けることによっても、指向性の高い光を確実に取り出すことができる。 In the light emitting element 7a of the present embodiment, the configuration in which the reflection mirror 74 is provided on the side opposite to the side where the concave mirror 72 of the light source 73 is disposed is described as an example. However, the configuration is not limited thereto.
For example, on the side opposite to the side where the concave mirror of the light source is arranged, the light from the light source emitted in a direction different from the concave mirror is directed in the same direction as the traveling direction of the light collimated by the concave mirror. A collimating lens may be provided. According to this configuration, the light emitted from the side opposite to the side where the concave mirror of the light source is disposed (the light from the light source not directly incident on the concave mirror) is collimated by the collimating lens, and the mounting surface of the package The collimated light is extracted from. Therefore, by providing a collimating lens instead of the reflecting mirror, light with high directivity can be reliably extracted.
　ここで、本発明者らは、本実施形態の各発光素子の効果を実証するために、凹面ミラーの傾斜角度を変えたときの導光体５に向けて射出される光の射出光束量を求めるシミュレーションを行った。
　以下、シミュレーション結果について図４Ａ～図５Ｃを用いて説明する。
　図４Ａ～４Ｃは、本実施形態の各発光素子を示す断面図である。図４Ａは、第１発光素子７ａを示す断面図である。図４Ｂは、第２発光素子７ｂを示す断面図である。図４Ｃは、第３発光素子７ｃを示す断面図である。
　図５Ａ～５Ｃは、本実施形態の各発光素子における角度と射出光束量の関係を示すシミュレーション結果である。図５Ａは、傾斜角度が第１発光素子７ａにおける光取り出しの様子を示すグラフである。図５Ｂは、第２発光素子７ｂにおける光取り出しの様子を示すグラフである。図５Ｃは、第３発光素子７ｃにおける光取り出しの様子を示すグラフである。図５Ａ～５Ｃのグラフの横軸は、凹面ミラーの中心軸と取付面の法線とのなす角度（傾斜角度）θ［°］である。図５Ａ～５Ｃのグラフの縦軸は、射出光束量［lumen］である。 Here, in order to verify the effect of each light emitting element of the present embodiment, the inventors set the amount of emitted light flux of light emitted toward the light guide 5 when the inclination angle of the concave mirror is changed. The required simulation was performed.
Hereinafter, simulation results will be described with reference to FIGS. 4A to 5C.
4A to 4C are cross-sectional views showing the light-emitting elements of this embodiment. FIG. 4A is a cross-sectional view showing the first light emitting element 7a. FIG. 4B is a cross-sectional view showing the second light emitting element 7b. FIG. 4C is a cross-sectional view showing the third light emitting element 7c.
FIGS. 5A to 5C are simulation results showing the relationship between the angle and the amount of emitted light in each light-emitting element of this embodiment. FIG. 5A is a graph showing how light is extracted in the first light emitting element 7a with an inclination angle. FIG. 5B is a graph showing a state of light extraction in the second light emitting element 7b. FIG. 5C is a graph showing a state of light extraction in the third light emitting element 7c. 5A to 5C is an angle (inclination angle) θ [°] formed by the central axis of the concave mirror and the normal of the mounting surface. The vertical axis of the graphs in FIGS. 5A to 5C represents the amount of luminous flux [lumen].
　基本構成は本実施形態の発光素子と同様であり、光源および反射ミラーがパッケージの凹部に樹脂（光透過部材）によって埋設されているものとした。シミュレーションの条件は、各発光素子７ａ，７ｂ，７ｃにおいて、放物面ミラーのサイズ（中心軸ＣＬ１と平行な方向から視た円の直径）を直径８ｍｍ、反射ミラーのサイズ（中心軸ＣＬ１と平行な方向から視た正方形の一辺）を１ｍｍ、チップＬＥＤのサイズ（中心軸ＣＬ１と平行な方向から視た正方形の一辺）を２５０μｍ、放物面ミラーの曲率半径を５．４ｍｍ、埋設した樹脂の屈折率を１．５、とした。そして、各発光素子７ａ，７ｂ，７ｃにおいて、導光体５に向けて射出される光の射出光束量を求めた。 The basic configuration is the same as that of the light emitting device of the present embodiment, and the light source and the reflection mirror are embedded in the concave portion of the package with resin (light transmitting member). The simulation conditions were as follows: in each light emitting element 7a, 7b, 7c, the size of the parabolic mirror (diameter of the circle viewed from the direction parallel to the central axis CL1) was 8 mm in diameter, and the size of the reflecting mirror (parallel to the central axis CL1). The side of the square viewed from one direction) is 1 mm, the size of the chip LED (one side of the square viewed from the direction parallel to the central axis CL1) is 250 μm, the radius of curvature of the parabolic mirror is 5.4 mm, and the embedded resin The refractive index was 1.5. And in each light emitting element 7a, 7b, 7c, the emitted light beam amount of the light inject | emitted toward the light guide 5 was calculated | required.
　図５Ａに示すように、第１発光素子７ａにおける射出光束量は傾斜角度３６．８９８°において最大値が得られた。また、第１発光素子７ａから射出される光の強度分布の半値幅（ＦＷＨＭ；ｆｕｌｌｗｉｄｔｈａｔｈａｌｆｍａｘｉｍｕｍ）は３．２°であった。 As shown in FIG. 5A, the maximum amount of light flux emitted from the first light emitting element 7a was obtained at an inclination angle of 36.898 °. Further, the full width at half maximum (FWHM) of the intensity distribution of light emitted from the first light emitting element 7a was 3.2 °.
　図５Ｂに示すように、第２発光素子７ｂにおける射出光束量は傾斜角度２５．９２８°において最大値が得られた。また、第２発光素子７ｂから射出される光の強度分布の半値幅（ＦＷＨＭ）は３．２°であった。 As shown in FIG. 5B, the maximum amount of light flux emitted from the second light emitting element 7b was obtained at an inclination angle of 25.928 °. In addition, the half width (FWHM) of the intensity distribution of the light emitted from the second light emitting element 7b was 3.2 °.
　図５Ｃに示すように、第３発光素子７ｃにおける射出光束量は傾斜角度１４．９５８°において最大値が得られた。また、第３発光素子７ｃから射出される光の強度分布の半値幅（ＦＷＨＭ）は３．２°であった。 As shown in FIG. 5C, the maximum amount of emitted light flux in the third light emitting element 7c was obtained at an inclination angle of 14.958 °. Further, the full width at half maximum (FWHM) of the intensity distribution of the light emitted from the third light emitting element 7c was 3.2 °.
　このシミュレーション結果から、凹面ミラーの傾斜角度をいずれの角度に変えた場合でも、発光素子から指向性の高い光を取り出すことができることが判った。 From this simulation result, it was found that even when the inclination angle of the concave mirror was changed to any angle, light with high directivity could be extracted from the light emitting element.
[第２の実施形態]
　以下、本発明の第２の実施形態について、図６を用いて説明する。
　本実施形態の発光素子の基本構成は第１の実施形態と同様であり、蓋部材が設けられている点が第１の実施形態と異なるのみである。よって、本実施形態では、発光素子の基本構成の説明は省略し、蓋部材の構造についてのみ説明する。
　図６は、本実施形態の発光素子を示す断面図である。
　なお、図６において、第１の実施形態で用いた図３と共通の構成要素には同一の符号を付し、その説明は省略する。 [Second Embodiment]
Hereinafter, a second embodiment of the present invention will be described with reference to FIG.
The basic configuration of the light emitting device of this embodiment is the same as that of the first embodiment, and only the point that a lid member is provided is different from that of the first embodiment. Therefore, in this embodiment, description of the basic structure of a light emitting element is abbreviate | omitted, and only the structure of a cover member is demonstrated.
FIG. 6 is a cross-sectional view showing the light emitting device of this embodiment.
In FIG. 6, the same components as those in FIG. 3 used in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.
　第１の実施形態では、光源７３および反射ミラー７４がパッケージ７１の凹部７１ａに光透過部材７５によって埋設され、光透過部材７５の光射出面が導光体５の第１端面５ｃに取り付けられる取付面となっていた。これに対して、本実施形態の発光素子１０７では、図６に示すように、光源７３および反射ミラー７４が蓋部材７６の裏面７６ａに取り付けられ、パッケージ７１の凹部７１ａの一部に蓋部材７６が嵌め込まれており、蓋部材７６の光射出面（表面）７６ｂが取付面となっている。 In the first embodiment, the light source 73 and the reflection mirror 74 are embedded in the recess 71 a of the package 71 by the light transmission member 75, and the light emission surface of the light transmission member 75 is attached to the first end surface 5 c of the light guide 5. It was a surface. On the other hand, in the light emitting element 107 of the present embodiment, as shown in FIG. 6, the light source 73 and the reflection mirror 74 are attached to the back surface 76 a of the lid member 76, and the lid member 76 is partly provided on the recess 71 a of the package 71. Is fitted, and the light emission surface (front surface) 76b of the lid member 76 is an attachment surface.
　蓋部材７６は、パッケージ７１の凹部７１ａを閉塞するための部材である。蓋部材７６の光射出面７６ｂは上述したパッケージ７１の取付面７１ｂと平行かつ平坦な面となっている。蓋部材７６の裏面７６ａは、凹面ミラー７２の中心軸ＣＬ１を法線とする平坦面となっている。 The lid member 76 is a member for closing the recess 71 a of the package 71. The light emission surface 76b of the lid member 76 is a flat surface parallel to the mounting surface 71b of the package 71 described above. The back surface 76a of the lid member 76 is a flat surface with the central axis CL1 of the concave mirror 72 as a normal line.
　蓋部材７６の形状は、所定の形状を有する金型を用いて樹脂の射出成形を行うなどの方法によって形成されている。あるいは、蓋部材７６の形状は、例えば元々平坦な樹脂部材の表面を切削加工することによって形成しても良い。 The shape of the lid member 76 is formed by a method such as injection molding of resin using a mold having a predetermined shape. Alternatively, the shape of the lid member 76 may be formed, for example, by cutting the surface of an originally flat resin member.
　本実施形態において、蓋部材７６によって閉塞されたパッケージ７１の凹部７１ａは、空気層１７５が封入されたいわゆる中空構造となっている。 In this embodiment, the recess 71a of the package 71 closed by the lid member 76 has a so-called hollow structure in which an air layer 175 is enclosed.
　このように、パッケージ７１の凹部７１ａを中空構造とすることもできるし、第１実施形態の構成と同様に光透過部材を配置することもできる。後者の場合、光透過部材は、パッケージ７１の凹部７１ａに凹面ミラー７２を配置し、このパッケージ７１の内部に、例えばアクリル樹脂等の光透過性を有する樹脂を注入して硬化させるなどして形成することができる。本実施形態においては、第１の実施形態と異なり、光源７３および反射ミラー７４が蓋部材７６の裏面７６ａに取り付けられているので、パッケージ７１の内部に光源７３および反射ミラー７４を配置することなしにパッケージ７１の内部に樹脂を注入させることができる。 As described above, the concave portion 71a of the package 71 can be a hollow structure, and a light transmitting member can be arranged in the same manner as in the configuration of the first embodiment. In the latter case, the light transmissive member is formed by disposing a concave mirror 72 in the concave portion 71a of the package 71, and injecting and curing a light transmissive resin such as an acrylic resin into the package 71, for example. can do. In the present embodiment, unlike the first embodiment, since the light source 73 and the reflection mirror 74 are attached to the back surface 76a of the lid member 76, the light source 73 and the reflection mirror 74 are not arranged inside the package 71. The resin can be injected into the package 71.
　なお、発光素子から射出される光の射出角度（導光体５を伝播する伝播角度）を補正したり射出角度を凹面ミラー７２の傾斜角度と異ならせたりするために、光透過部材の透過率を導光体５の屈折率ｎＷＧ（１．５）と異なる値にすることもできる。例えば、蓋部材７６をパッケージ７１から取り外し可能な構造とした場合、光透過部材を液状体とすることによって蓋部材７６の取り外しだけで液状体をパッケージ７１の内部に出し入れすることができるため、光透過部材の透過率の変更が容易となる。 In order to correct the emission angle of light emitted from the light emitting element (propagation angle propagating through the light guide 5) or to make the emission angle different from the inclination angle of the concave mirror 72, the transmittance of the light transmitting member. Can be a value different from the refractive index nWG (1.5) of the light guide 5. For example, when the lid member 76 is configured to be removable from the package 71, the liquid material can be taken in and out of the package 71 only by removing the lid member 76 by making the light transmitting member a liquid material. It becomes easy to change the transmittance of the transmissive member.
　本実施形態の発光素子１０７においては、蓋部材７６が設けられているので、外部からパッケージ７１の内部に不純物が侵入することを抑制することができる。 In the light emitting element 107 of the present embodiment, since the lid member 76 is provided, it is possible to prevent impurities from entering the package 71 from the outside.
[第３の実施形態]
　以下、本発明の第３の実施形態について、図７、図８Ａおよび図８Ｂを用いて説明する。
　本実施形態の発光素子の基本構成は第１の実施形態と同様であり、パッケージの凹部の形状および凹面ミラーの形状が第１の実施形態と異なるのみである。よって、本実施形態では、発光素子の基本構成の説明は省略し、パッケージの凹部の形状および凹面ミラーの形状についてのみ説明する。
　図７は、本実施形態の発光素子を示す斜視図である。
　図８Ａおよび８Ｂは、本実施形態の発光素子を示す模式図である。図８Ａは、発光素子の断面図である。図８Ｂは、発光素子の平面図である。
　なお、図７、図８Ａおよび図８Ｂにおいて、第１の実施形態で用いた図３と共通の構成要素には同一の符号を付し、その説明は省略する。 [Third embodiment]
Hereinafter, a third embodiment of the present invention will be described with reference to FIGS. 7, 8A and 8B.
The basic configuration of the light emitting device of this embodiment is the same as that of the first embodiment, and only the shape of the concave portion of the package and the shape of the concave mirror are different from those of the first embodiment. Therefore, in this embodiment, description of the basic structure of a light emitting element is abbreviate | omitted, and only the shape of the recessed part of a package and the shape of a concave mirror is demonstrated.
FIG. 7 is a perspective view showing the light emitting device of this embodiment.
8A and 8B are schematic views showing the light emitting device of this embodiment. FIG. 8A is a cross-sectional view of the light-emitting element. FIG. 8B is a plan view of the light emitting element.
7, 8 </ b> A, and 8 </ b> B, the same components as those in FIG. 3 used in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.
　第１の実施形態では、パッケージ７１の凹部７１ａの形状が、凹面ミラー７２の中心軸ＣＬ１と取付面７１ｂの法線ＣＬ２を含む仮想面の法線から視て、光源７３に対して凹となるような曲線状となっていた。また、凹面ミラー７２が放物面ミラーであり、凹面ミラー７２の中心軸ＣＬ１と平行な方向から視た形状が円形の回転対称形状のものであった。
　これに対して、本実施形態の発光素子２０７では、図７、図８Ａおよび図８Ｂに示すように、パッケージ２７１の凹部２７１ａの形状が光源７３に対して凹となるような曲線状となっており、さらに、当該凹部２７１ａを凹面ミラー２７２の中心軸ＣＬ１と取付面２７１ｂの法線ＣＬ２を含む仮想面で切断したときの形状が同じになっている。また、凹面ミラー２７２の中心軸ＣＬ１と平行な方向から視た形状が矩形となっている。 In the first embodiment, the shape of the recess 71 a of the package 71 is concave with respect to the light source 73 as viewed from the normal of the virtual plane including the central axis CL 1 of the concave mirror 72 and the normal CL 2 of the mounting surface 71 b. It was like a curve. The concave mirror 72 is a parabolic mirror, and the shape viewed from a direction parallel to the central axis CL1 of the concave mirror 72 is a circular rotationally symmetric shape.
On the other hand, in the light emitting element 207 of this embodiment, as shown in FIGS. 7, 8A and 8B, the concave portion 271a of the package 271 has a curved shape that is concave with respect to the light source 73. Furthermore, the shape when the concave portion 271a is cut by a virtual plane including the central axis CL1 of the concave mirror 272 and the normal line CL2 of the mounting surface 271b is the same. Further, the shape viewed from the direction parallel to the central axis CL1 of the concave mirror 272 is rectangular.
　本実施形態の発光素子２０７において、凹面ミラー２７２での反射光は、図８Ａに示すように仮想面（ＸＺ面）では指向性を持ち、図８Ｂに示すように仮想面と直交する面（ＸＹ面）では左右に広がる。よって、上下方向では指向性を持ち左右方向では広がりを持つ光を取り出すことが可能となる。 In the light emitting element 207 of the present embodiment, the reflected light from the concave mirror 272 has directivity on the virtual plane (XZ plane) as shown in FIG. 8A, and a plane (XY) orthogonal to the virtual plane as shown in FIG. 8B. In the plane). Therefore, it is possible to extract light having directivity in the vertical direction and spreading in the horizontal direction.
[表示装置の構成例]
　以下、表示装置の一構成例について、図９～図１１Ｂを用いて説明する。
　図９は、表示装置の一構成例である液晶表示装置の概略構成を示す分解斜視図である。
　図１０Ａ、図１０Ｂ、図１１Ａ、図１１Ｂは、液晶表示装置におけるバックライトの配置例を示す図である。 [Configuration example of display device]
Hereinafter, one configuration example of the display device will be described with reference to FIGS. 9 to 11B.
FIG. 9 is an exploded perspective view showing a schematic configuration of a liquid crystal display device which is a configuration example of the display device.
FIG. 10A, FIG. 10B, FIG. 11A, and FIG. 11B are diagrams showing examples of backlight arrangement in a liquid crystal display device.
　本構成例の液晶表示装置１２１は、図９に示すように、下側ケース１２２と、反射板１２３と、バックライト３（調光素子）と、拡散板１２４と、液晶パネル２（表示素子）と、上側ケース１２５と、を備えている。すなわち、反射板１２３とバックライト３と拡散板１２４と液晶パネル２との積層体が、下側ケース１２２および上側ケース１２５の内部に収容されている。バックライト３の液晶パネル２と反対側に反射板１２３を配置したことにより、バックライト３から液晶パネル２と反対側に漏れ出た光を反射させて表示に寄与させることができる。また、バックライト３と液晶パネル２との間に拡散板１２４を配置したことにより、バックライト３の輝度ムラを軽減することができる。ただし、反射板１２３や拡散板１２４は必ずしも用いなくても良い。 As shown in FIG. 9, the liquid crystal display device 121 of this configuration example includes a lower case 122, a reflecting plate 123, a backlight 3 (light control element), a diffusion plate 124, and a liquid crystal panel 2 (display element). And an upper case 125. That is, a laminated body of the reflecting plate 123, the backlight 3, the diffusion plate 124, and the liquid crystal panel 2 is accommodated in the lower case 122 and the upper case 125. By disposing the reflector 123 on the opposite side of the backlight 3 from the liquid crystal panel 2, light leaking from the backlight 3 to the opposite side of the liquid crystal panel 2 can be reflected and contributed to display. Further, by disposing the diffusion plate 124 between the backlight 3 and the liquid crystal panel 2, luminance unevenness of the backlight 3 can be reduced. However, the reflecting plate 123 and the diffusing plate 124 are not necessarily used.
　図１０Ａに示すように、液晶表示装置１２１の画面内において、各光取出領域ＲＡ，ＲＢ，ＲＣが画面の垂直方向に並ぶように、複数のバックライト３を配置する構成を採用することができる。もしくは、図１０Ｂに示すように、液晶表示装置１２７の画面内において、各光取出領域ＲＡ，ＲＢ，ＲＣが画面の水平方向に並ぶように、複数のバックライト３を配置する構成を採用することができる。 As shown in FIG. 10A, a configuration in which a plurality of backlights 3 are arranged in the screen of the liquid crystal display device 121 so that the light extraction areas RA, RB, RC are arranged in the vertical direction of the screen can be employed. . Alternatively, as shown in FIG. 10B, a configuration in which a plurality of backlights 3 are arranged so that the light extraction areas RA, RB, RC are arranged in the horizontal direction of the screen in the screen of the liquid crystal display device 127 is adopted. Can do.
　もしくは、図１１Ａおよび１１Ｂに示すように、長手方向の一部にのみ光取出領域ＲＡ，ＲＢ，ＲＣが設けられ、その他の部分は光が導光する領域となった細長い棒状の導光体１３５を複数本（本例では３本）組み合わせたバックライト１３７を用いても良い。複数本の導光体１３５は光取出領域ＲＡ，ＲＢ，ＲＣが設けられた領域が長手方向にずれている。そのため、複数本の導光体１３５を組み合わせたときに、導光体１３５の長手方向にわたって光取出領域ＲＡ，ＲＢ，ＲＣが並ぶような形態となる。 Alternatively, as shown in FIGS. 11A and 11B, the light extraction regions RA, RB, RC are provided only in a part in the longitudinal direction, and the other portions are elongated rod-shaped light guides 135 that are regions where light is guided. A backlight 137 that combines a plurality of (three in this example) may be used. In the plurality of light guides 135, regions where the light extraction regions RA, RB, RC are provided are shifted in the longitudinal direction. Therefore, when a plurality of light guides 135 are combined, the light extraction regions RA, RB, and RC are arranged along the longitudinal direction of the light guide 135.
　例えば、図１１Ａに示すように、液晶表示装置１３１の画面内において、各光取出領域ＲＡ，ＲＢ，ＲＣが画面の垂直方向に並ぶように、複数のバックライト１３７を配置する構成としても良い。もしくは、図１１Ｂに示すように、液晶表示装置１３３の画面内において、各光取出領域ＲＡ，ＲＢ，ＲＣが画面の水平方向に並ぶように、複数のバックライト１３７を配置する構成としても良い。 For example, as shown in FIG. 11A, a plurality of backlights 137 may be arranged in the screen of the liquid crystal display device 131 so that the light extraction areas RA, RB, RC are arranged in the vertical direction of the screen. Alternatively, as shown in FIG. 11B, a plurality of backlights 137 may be arranged in the screen of the liquid crystal display device 133 so that the light extraction areas RA, RB, RC are arranged in the horizontal direction of the screen.
[照明装置の構成例]
　以下、照明装置の２つの構成例について、図１２、図１３Ａおよび図１３Ｂを用いて説明する。
　図１２は、第１の構成例である照明装置の断面図である。図１３Ａおよび１３Ｂは、第２の構成例である照明装置を示す図であって、図１３Ａは第２の構成例である照明装置の平面図、図１３Ｂは図１３ＡのＡ－Ａ’線に沿う第２の構成例である照明装置の断面図である。 [Configuration example of lighting device]
Hereinafter, two configuration examples of the lighting device will be described with reference to FIGS. 12, 13A, and 13B.
FIG. 12 is a cross-sectional view of the lighting device as the first configuration example. 13A and 13B are diagrams showing a lighting apparatus as a second configuration example. FIG. 13A is a plan view of the lighting apparatus as a second configuration example, and FIG. 13B is a line AA ′ in FIG. 13A. It is sectional drawing of the illuminating device which is the 2nd structural example which follows.
　例えば図１２に示す照明装置２０１では、導光体５の第１主面５ａ側に屈折率が１．３の第１低屈折率体８ａが形成され、第２主面５ｂ側に屈折率が１．４の第２低屈折率体８ｂが形成されている。また、第１低屈折率体８ａ上、第２低屈折率体８ｂ上には光散乱体１０が積層されている。その他の構成は第１の実施形態と同様である。なお、図１２では一つの第１端面５ｃしか図示していないが、実際には紙面の奥行き方向に第１主面５ａに対する角度が異なる他の一つの第１端面が形成されている。発光素子についても、一つの発光素子７ａしか図示していないが、実際には紙面の奥行き方向に他の一つのＬＥＤが設置されている。 For example, in the illumination device 201 shown in FIG. 12, the first low refractive index body 8a having a refractive index of 1.3 is formed on the first main surface 5a side of the light guide 5 and the refractive index is on the second main surface 5b side. A second low refractive index body 8b of 1.4 is formed. A light scatterer 10 is stacked on the first low refractive index body 8a and the second low refractive index body 8b. Other configurations are the same as those of the first embodiment. In FIG. 12, only one first end face 5c is shown, but actually, another one first end face having a different angle with respect to the first main face 5a is formed in the depth direction of the paper. As for the light emitting element, only one light emitting element 7a is shown, but actually another one LED is installed in the depth direction of the drawing.
　この照明装置２０１において、導光体５の第１端面５ｃに設けられた２つの発光素子のうち、いずれの発光素子を点灯させるかによって、第１主面５ａ側から光を射出させるか、第２主面５ｂ側から光を射出させるかを切り換えることができる。したがって、発光面を切り換えることが可能な照明装置を実現することができる。 In the illumination device 201, the light emitting element 201 emits light from the first main surface 5a side depending on which one of the two light emitting elements provided on the first end surface 5c of the light guide 5 is lit. It is possible to switch whether light is emitted from the two principal surfaces 5b side. Therefore, it is possible to realize an illumination device that can switch the light emitting surface.
　また、図１３Ａに示す照明装置２０３では、導光体５の一面に「ＳＨＡＲＰ」と書かれた文字部２０４が形成されている。文字部２０４に対応して、図１３Ｂに示すように、導光体５の第１主面５ａ側に屈折率が１．３の第１低屈折率体８ａが形成されており、文字部２０４以外の部分には第１低屈折率体８ａが形成されていない。また、第１低屈折率体８ａ上には光散乱体１０が積層されている。すなわち、文字部２０４が上記実施形態における光取出領域となっている。その他の構成は第１の実施形態と同様である。なお、図１３Ｂでは一つの第１端面５ｃしか図示していないが、実際には紙面の奥行き方向に第１主面５ａに対する角度が異なる他の一つの第１端面が形成されている。発光素子についても、一つの発光素子７ａしか図示していないが、実際には紙面の奥行き方向に他の一つの発光素子が設置されている。 Further, in the lighting device 203 shown in FIG. 13A, a character portion 204 written “SHARP” is formed on one surface of the light guide 5. Corresponding to the character portion 204, as shown in FIG. 13B, a first low refractive index body 8a having a refractive index of 1.3 is formed on the first main surface 5a side of the light guide 5, and the character portion 204 is formed. The first low refractive index body 8a is not formed in any other part. A light scatterer 10 is stacked on the first low refractive index body 8a. That is, the character part 204 is a light extraction area in the above embodiment. Other configurations are the same as those of the first embodiment. Although only one first end face 5c is shown in FIG. 13B, in actuality, another first end face having a different angle with respect to the first main face 5a is formed in the depth direction of the paper. As for the light emitting element, only one light emitting element 7a is shown, but actually, another one light emitting element is installed in the depth direction of the drawing.
　この照明装置２０３において、導光体５の第１端面５ｃに設けられた２つの発光素子のうち、いずれの発光素子を点灯させるかによって、文字部２０４から光を射出させるか、文字部２０４以外から光を射出させるかを切り換えることができる。したがって、本構成によれば、例えば文字部２０４の点滅が可能なデジタルサイネージとして利用可能な照明装置を実現できる。 In the lighting device 203, light is emitted from the character part 204 depending on which of the two light emitting elements provided on the first end surface 5 c of the light guide 5 is lit, or other than the character part 204. It is possible to switch whether light is emitted from Therefore, according to this structure, the illuminating device which can be utilized as digital signage which can blink the character part 204, for example is realizable.
　なお、本発明の態様における技術範囲は上記実施形態に限定されるものではなく、本発明の態様における趣旨を逸脱しない範囲において種々の変更を加えることが可能である。
　例えば上記第１の実施形態では、３個の発光素子を導光体の短手方向（図１のｙ軸方向）に並べて配置したが、この配置に代えて、複数の発光素子を導光体の厚さ方向（図１のｚ軸方向）に並べて配置しても良い。 The technical scope in the aspect of the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the aspect of the present invention.
For example, in the first embodiment, three light emitting elements are arranged side by side in the short direction of the light guide (y-axis direction in FIG. 1). Instead of this arrangement, a plurality of light emitting elements are arranged in the light guide. May be arranged side by side in the thickness direction (z-axis direction in FIG. 1).
　また、上記実施形態においては、発光素子を導光体の端面に配置した構成を例に挙げて説明したが、これに限らず、発光素子を単品で使用することも可能である。ここで、発光素子の取付面での光の屈折を考える。発光素子の取付面が、屈折率１．５の光透過部材と屈折率１．０の空気層との界面となる場合を考える。例えば、外部の空気層に対して約１５°の射出角度で光を取り出したい場合は、凹面ミラーの傾斜角度を約１０°に設定する。 In the above embodiment, the configuration in which the light emitting element is disposed on the end face of the light guide has been described as an example. However, the present invention is not limited thereto, and the light emitting element can be used alone. Here, refraction of light on the mounting surface of the light emitting element is considered. Consider a case where the mounting surface of the light emitting element is an interface between a light transmitting member having a refractive index of 1.5 and an air layer having a refractive index of 1.0. For example, when it is desired to extract light at an emission angle of about 15 ° with respect to the external air layer, the inclination angle of the concave mirror is set to about 10 °.
　また、液晶表示装置の全体構成としては、液晶パネルとバックライトとの間に光拡散フィルム、プリズムシート等の光学部材を適宜配置しても良い。これらの光学部材を用いることで、輝度ムラの更なる低減、光の拡散角度や拡散方向の調整等を行うことができる。
　その他、上記実施形態における各種構成要素の形状、寸法、数、配置、構成材料、製造方法等については、上記実施形態で例示したものに限らず、適宜変更が可能である。 Further, as an overall configuration of the liquid crystal display device, an optical member such as a light diffusion film or a prism sheet may be appropriately disposed between the liquid crystal panel and the backlight. By using these optical members, it is possible to further reduce luminance unevenness and adjust the light diffusion angle and direction.
In addition, the shape, size, number, arrangement, constituent material, manufacturing method, and the like of various components in the above embodiment are not limited to those illustrated in the above embodiment, and can be changed as appropriate.
　本発明の態様は、液晶表示装置、その他、発光素子を備えた調光素子を用いて表示を行うことが可能な各種表示装置に利用可能である。 The aspect of the present invention can be used for a liquid crystal display device and other various display devices capable of performing display using a light control element including a light emitting element.
１，１２１，１２７，１３１，１３３…液晶表示装置（表示装置）、２…液晶パネル（表示素子）、３，１３７…バックライト（調光素子）、５，１３５…導光体、６…照明部、７，７ａ，７ｂ，７ｃ，１０７、２０７…発光素子、７１，２７１…パッケージ、７１ａ，２７１ａ…凹部、７１ｂ，２７１ｂ…取付面、７２，２７２…凹面ミラー、７３…光源、７４…反射ミラー、７５，２７５…光透過部材、７６…蓋部材、７６ａ…蓋部材の裏面、７６ｂ…蓋部材の表面、２０１，２０３…照明装置、ＣＬ１…凹面ミラーの中心軸（凹面ミラーの中心点と焦点とを結ぶ直線）、ＣＬ２…取付面の法線、Ｐｃ…凹面ミラーの中心点、Ｐｆ…焦点、ＲＡ…第１光取出領域、ＲＢ…第２光取出領域、ＲＣ…第３光取出領域、φ…伝播角度 DESCRIPTION OF SYMBOLS 1,121,127,131,133 ... Liquid crystal display device (display device), 2 ... Liquid crystal panel (display element), 3,137 ... Backlight (light control element), 5,135 ... Light guide, 6 ... Illumination 7, 7a, 7b, 7c, 107, 207 ... light emitting element, 71,271 ... package, 71a, 271a ... recess, 71b, 271b ... mounting surface, 72,272 ... concave mirror, 73 ... light source, 74 ... reflection Mirror, 75, 275 ... light transmitting member, 76 ... lid member, 76a ... back surface of the lid member, 76b ... surface of the lid member, 201,203 ... illuminating device, CL1 ... center axis of the concave mirror (the central point of the concave mirror and Straight line connecting the focal point), CL2 ... normal of the mounting surface, Pc ... center point of the concave mirror, Pf ... focal point, RA ... first light extraction region, RB ... second light extraction region, RC ... third light extraction region. , Φ ... Propagation angle

Claims (11)

  1. 　発光素子は、導光体に取り付けるための取付面を有し、
    　前記発光素子は、
    　凹部が形成されたパッケージと、
    　前記パッケージの前記凹部に設けられた凹面ミラーと、
    　前記凹面ミラーの焦点に配置された光源と、
    　を備え、
    　前記凹面ミラーの中心点と前記焦点とを結ぶ直線は、前記取付面の法線と斜めに交差している発光素子。     The light emitting element has an attachment surface for attaching to the light guide,
    The light emitting element is
    A package in which a recess is formed;
    A concave mirror provided in the recess of the package;
    A light source disposed at the focal point of the concave mirror;
    With
    A light-emitting element in which a straight line connecting the center point of the concave mirror and the focal point obliquely intersects the normal of the mounting surface.
  2. 　前記直線は、前記光源の光射出面の法線と一致している請求項１に記載の発光素子。 The light-emitting element according to claim 1, wherein the straight line coincides with a normal line of a light emission surface of the light source.
  3. 　前記凹面ミラーは、放物面ミラーであり、
    　前記直線は、前記放物面ミラーの回転対称軸と一致している請求項１に記載の発光素子。     The concave mirror is a parabolic mirror;
    The light emitting device according to claim 1, wherein the straight line coincides with a rotational symmetry axis of the parabolic mirror.
  4. 　さらに反射ミラーを備え、
    　前記反射ミラーは、前記光源が前記凹面ミラーと前記反射ミラーとの間に配置されるように配置され、前記反射ミラーは、前記凹面ミラーと異なる方向に射出された前記光源からの光を、前記凹面ミラーに向けて反射する請求項１に記載の発光素子。     In addition, with a reflection mirror,
    The reflection mirror is disposed so that the light source is disposed between the concave mirror and the reflection mirror, and the reflection mirror emits light from the light source emitted in a different direction from the concave mirror, The light-emitting element according to claim 1, which reflects toward the concave mirror.
  5. 　さらに、前記光源から射出された光を透過する光透過部材を備え、
    　前記光源は、前記パッケージの前記凹部に、前記光透過部材によって埋設されており、
    　前記光透過部材は、前記取付面を形成している請求項１に記載の発光素子。     Furthermore, a light transmission member that transmits the light emitted from the light source,
    The light source is embedded in the concave portion of the package by the light transmitting member,
    The light-emitting element according to claim 1, wherein the light transmission member forms the attachment surface.
  6. 　さらに蓋部材を備え、
    　前記蓋部材は、前記取付面を形成し、
    　前記蓋部材は、前記凹部を閉塞するよう配置されている請求項１に記載の発光素子。     Furthermore, a lid member is provided,
    The lid member forms the mounting surface;
    The light emitting device according to claim 1, wherein the lid member is disposed so as to close the concave portion.
  7. 　前記蓋部材の裏面に、前記光源が取り付けられている請求項６に記載の発光素子。 The light-emitting element according to claim 6, wherein the light source is attached to a back surface of the lid member.
  8. 　射出する光の量を制御可能な照明部と、
    　前記照明部から射出された光が入射され、前記光を内部で全反射させつつ伝播させる導光体とを備え、
    　前記導光体は、前記照明部から射出された光が導光体内部で全反射しつつ伝播される間に前記照明部から射出された光を外部に取り出す複数の光取出領域を有し、
    　前記複数の光取出領域のうちの少なくとも２つの光取出領域は、前記照明部から射出された光を外部に取り出し可能な入射角範囲が互いに異なり、
    　前記導光体は、前記照明部から射出された光を、前記導光体の内部を複数の異なる伝播角度で伝播させるよう構成され、
    　前記照明部は、前記導光体に取り付けるための取付面を有する発光素子を備え、
    　前記発光素子は、
    　凹部が形成されたパッケージと、
    　前記パッケージの前記凹部に設けられた凹面ミラーと、
    　前記凹面ミラーの焦点に配置された光源と、
    　を備え、
    　前記凹面ミラーの中心点と前記焦点とを結ぶ直線は、前記取付面の法線と斜めに交差している調光素子。     An illumination unit capable of controlling the amount of light emitted;
    The light emitted from the illumination unit is incident, and includes a light guide that propagates the light while totally reflecting the light inside,
    The light guide has a plurality of light extraction regions for extracting the light emitted from the illumination unit to the outside while the light emitted from the illumination unit is propagated while being totally reflected inside the light guide.
    At least two light extraction regions of the plurality of light extraction regions have different incident angle ranges in which the light emitted from the illumination unit can be extracted to the outside,
    The light guide is configured to propagate the light emitted from the illumination unit at a plurality of different propagation angles inside the light guide.
    The illumination unit includes a light emitting element having an attachment surface for attachment to the light guide,
    The light emitting element is
    A package in which a recess is formed;
    A concave mirror provided in the recess of the package;
    A light source disposed at the focal point of the concave mirror;
    With
    A dimming element in which a straight line connecting the center point of the concave mirror and the focal point obliquely intersects the normal of the mounting surface.
  9. 　前記導光体の端面は、前記光取出領域が設けられた面に対して直交しており、
    　前記導光体の端面には、前記発光素子が複数配置されており、
    　前記複数の発光素子の各々は、射出された光が前記光取出領域に対して互いに異なる入射角で入射するように、前記直線が前記光取出領域に対して異なる向きになるよう配置されている請求項８に記載の調光素子。     The end surface of the light guide is orthogonal to the surface on which the light extraction region is provided,
    A plurality of the light emitting elements are arranged on the end face of the light guide,
    Each of the plurality of light emitting elements is arranged so that the straight line is in a different direction with respect to the light extraction region so that the emitted light is incident on the light extraction region at different incident angles. The light control element according to claim 8.
  10. 　請求項８に記載の調光素子と、
    　前記調光素子から射出される光を用いて表示を行う表示素子と、
    　を備えている表示装置。     A light control device according to claim 8,
    A display element that performs display using light emitted from the light control element;
    A display device comprising:
  11. 　請求項８に記載の調光素子を備えている照明装置。 A lighting device comprising the light control element according to claim 8.
PCT/JP2011/078765 2010-12-16 2011-12-13 Light emitting element, light adjusting element, display device, and lighting device WO2012081569A1 (en)

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