KR20110062498A - Led type backlight unit - Google Patents

Led type backlight unit Download PDF

Info

Publication number
KR20110062498A
KR20110062498A KR1020090119240A KR20090119240A KR20110062498A KR 20110062498 A KR20110062498 A KR 20110062498A KR 1020090119240 A KR1020090119240 A KR 1020090119240A KR 20090119240 A KR20090119240 A KR 20090119240A KR 20110062498 A KR20110062498 A KR 20110062498A
Authority
KR
South Korea
Prior art keywords
light source
led
led light
backlight unit
printed circuit
Prior art date
Application number
KR1020090119240A
Other languages
Korean (ko)
Inventor
유종선
조남인
Original Assignee
선문대학교 산학협력단
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 선문대학교 산학협력단 filed Critical 선문대학교 산학협력단
Priority to KR1020090119240A priority Critical patent/KR20110062498A/en
Publication of KR20110062498A publication Critical patent/KR20110062498A/en

Links

Images

Classifications

    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333—Constructional arrangements; Manufacturing methods
    • G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
    • G02F1/1336—Illuminating devices
    • G02F1/133602—Direct backlight
    • G02F1/133603—Direct backlight with LEDs
    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333—Constructional arrangements; Manufacturing methods
    • G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
    • G02F1/1336—Illuminating devices
    • G02F1/133602—Direct backlight
    • G02F1/133608—Direct backlight including particular frames or supporting means
    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333—Constructional arrangements; Manufacturing methods
    • G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
    • G02F1/1336—Illuminating devices
    • G02F1/133602—Direct backlight
    • G02F1/133611—Direct backlight including means for improving the brightness uniformity

Landscapes

  • Physics & Mathematics (AREA)
  • Nonlinear Science (AREA)
  • Mathematical Physics (AREA)
  • Chemical & Material Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Planar Illumination Modules (AREA)

Abstract

In the LED type backlight unit (BLU) of the present invention, a plurality of LED light source mounting units are disposed on a surface of a printed circuit board (PCB), and the LED light source is mounted on the downward inclination side of the LED light source mounting unit. Since the light emitted from the light emitting plate may be obliquely incident on the incident surface of the diffuser plate or the light guide plate, the occurrence of luminance smear on the diffuser plate or the light guide plate may be suppressed, and uniform luminance may be provided to the LCD panel.

Description

LED type backlight unit {LED TYPE BACKLIGHT UNIT}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light emitting diode (LED) type backlight unit (BLU), and more particularly to an LED light source inclined with respect to a surface of a printed circuit board (PCB). An LED type backlight unit (BLU) is mounted so that light is obliquely incident on an incident surface of a diffusion plate or a light guide plate.

Cold cathode fluorescent lamp (CCFL) has been mainly used as a light emitting unit in the backlight unit (BLU), but LED (LED) is suitable for low power consumption by low voltage operation, and is a thin backlight unit (BLU). As it is environmentally friendly, it is being replaced by cold cathode fluorescent lamps (CCFL). LED type BLU, which adopts LED as a light source, has been mainly adopted in small and medium size LCD monitors and LCD TVs until recently. It is also being applied to large LCD TVs of 40 inches or larger. Such LED type backlight units are classified into a top-emitting type and a side-emitting type.

1 is an exploded perspective view showing a conventional direct-emitting LED type backlight unit. As shown in FIG. 1, in the direct emission type LED type backlight unit 10, a plurality of LED light sources 12 are arranged in a grid on the printed circuit board 11, and the LED light sources 12 are not disposed. A reflective sheet (not shown) may be disposed on the portion of the printed circuit board 11, and the diffusion plate 13 and the diffusion sheet 15 may cross each other at right angles on the LED light source 12. A light collecting sheet 17 composed of a pair of light collecting sheets 17a and 17b having a prism array, and a protective film 19 are sequentially arranged.

In the direct emission type LED backlight unit 10 having such a structure, the light emitted from the LED light source 12 is incident toward the incident surface which is the lower surface of the diffuser plate 13. In addition, when a reflective sheet (not shown) is disposed on the printed circuit board 11 in a portion where the LED light source 12 is not disposed, it is emitted from the LED light source 12 and then directly to the incident surface of the diffusion plate 13. The light which has not entered is reflected by the reflecting sheet and is incident on the incident surface of the diffusion plate 13. The light incident on the incidence surface of the diffusion plate 13 diffuses in various traveling directions while traveling toward the upper surface of the diffusion plate 13, so that the direction of travel of the light becomes relatively uniform. Thereafter, the light emitted from the upper surface of the diffusion plate 13 is diffused in various traveling directions while passing through the diffusion sheet 15, so that the direction of light travel becomes more uniform. The light emitted from the diffusion sheet 15 is collected while passing through the pair of light collecting sheets 17a and 17b, whereby the direction of light travel is further improved in the front direction, thereby increasing the luminance. Light emitted from the light collecting sheet 17 finally enters, for example, an LCD panel (not shown) via the protective film 19.

Figure 2 is an exploded perspective view showing a conventional side-emitting LED type backlight unit. As shown in FIG. 2, in the side-emitting type LED backlight unit 20, a plurality of LED light sources 22 are linearly arranged on the printed circuit board 21, and the LED light source 22 and the light guide plate 23 are disposed. The light guide plate 23 is disposed adjacent to the LED light source 22 in the lateral direction so that the incident surface (left side) of the light source 22 faces, and the diffusion sheet 25 on the light guide plate 23 has an array of prisms that cross at right angles to each other. The light collecting sheet 27 composed of a pair of light collecting sheets 27a and 27b, and the protective film 29 are sequentially arranged. Further, on the side portion of the printed circuit board 21, a reflecting plate 24 having a form surrounding the rear portion and both sides of the printed circuit board 21, for example, a depressed shape, is disposed. Reflectors 26 are disposed on the lower and right surfaces of the light guide plate 23.

In the side-emitting type LED backlight unit 20 having such a structure, the light emitted from the LED light source 22 is incident toward the left side surface of the incident surface 23a of the light guide plate 23. In addition, the light that does not directly enter the incident surface 23a of the light guide plate 23 is reflected by the reflecting plate 24 and enters the incident surface 23a of the light guide plate 23. The light incident on the incident surface 23a of the light guide plate 23 travels to the right side surface 23b of the light guide plate 23 while totally reflecting by the top and bottom surfaces of the light guide plate 23 while the light guide plate 23 runs in the lateral direction. Light exiting to the lower surface and the right surface 23b of the light guide plate 23 is reflected by the reflective sheet 26 to the light guide plate 23. The light is scattered by a plurality of scattering patterns (not shown) formed on a lower surface of the light guide plate 23 or reflected by the reflective sheet 26 in the process of traveling in the light guide plate 23. It is changed upwards toward the top surface of the. Through this process, the light exits from the upper surface of the light guide plate 23 toward the diffusion sheet 25. As the light emitted from the diffusion sheet 25 passes through the diffusion sheet 25 and diffuses in various travel directions, the direction of travel of the light becomes uniform. The light emitted from the diffusion sheet 25 is condensed while passing through the pair of light collecting sheets 27a and 27b, whereby the direction of travel of the light is further improved in the front direction and the luminance is increased. Light emitted from the light collecting sheet 27 finally enters, for example, an LCD panel (not shown) via the protective film 29.

FIG. 3 is a side view of the direct-emitting type LED backlight unit 10 illustrated in FIG. 1, and FIG. 3A illustrates a case where the distance between the LED light source and the diffuser plate is farther than the distance between adjacent LED light sources. Fig. 3B is a view showing an example in which the luminance spots do not occur in the diffuser plate. It is a figure which shows the example which generate | occur | produced. For convenience of explanation, in order to help the explanation, the diffusion sheet, the light collecting sheet, and the protective film which are disposed on the diffusion plate are not shown in FIGS. 3A and 3B.

As shown in FIG. 3A, when the distance D1 between the LED light source 12 and the diffuser plate 13 is farther than the distance W1 between the adjacent LED light sources 12, the diffuser plate 13 Since a uniform amount of light per unit area is incident on the incident surface of the light emitting diode, uniform luminance is formed on the surface of the backlight unit 10 together with the diffusion sheets 15 and the light collecting sheets 17a and 17b. Accordingly, the backlight unit 10 may provide uniform luminance to an LCD panel (not shown), for example.

On the other hand, as shown in FIG. 3B, when the distance D2 between the LED light source 12 and the diffuser plate 13 is shorter than the gap W1 between the adjacent LED light sources 12, the diffusion is performed. Since a uniform amount of light per unit area is not incident on the incident surface of the plate 13, hot spots 13a and dark zones 13b are formed in the diffusion plate 13, so that the diffusion plate 13 is formed. Luminance unevenness occurs. In this state, even if the diffusion sheet 15 and the light collecting sheets 17a and 17b are additionally disposed on the diffusion plate 13, the backlight unit 10 may provide uniform luminance to an LCD panel (not shown), for example. none.

FIG. 4 is a side view of the side-emitting LED type backlight unit 20 illustrated in FIG. 2, in which a luminance stain is generated on the light guide plate when the distance between the LED light source and the light guide plate is shorter than the distance between adjacent LED light sources. The figure shown. For convenience of description, in order to help the understanding of the description, FIG. 4 illustrates a diffusion sheet, a light collecting sheet, and a protective film disposed on the light guide plate.

As shown in FIG. 4, when the distance D3 between the LED light source 22 and the light guide plate 23 is larger than the distance W3 between the adjacent LED light sources 22, the incident surface 23a of the light guide plate 23 is shown. ), The light spot 23c and the dark zone 23d are formed near the incident surface 23a of the light guide plate 23 so that a uniform amount of light is not incident on the light guide plate 23. The luminance unevenness generating area 23e is generated. In this state, even if the diffusion sheet 25 and the light collecting sheets 27a and 27b are additionally disposed on the light guide plate 23, the backlight unit 20 may not provide uniform luminance to an LCD panel (not shown), for example. .

In order to solve this problem, the entire luminance unevenness generating area 23e of the light guide plate 23 is shielded by an opaque backlight chassis (not shown). As the luminance unevenness generating area 23e is wider, the LED type backlight unit 20 Since the effective area is reduced, it is necessary to reduce or eliminate the luminance unevenness generating area 23e.

As described above, the LED light source is disposed horizontally on a flat surface of the printed circuit board in the direct emission type or the side emission type LED backlight unit. At present, there is an urgent need for a new method to solve this problem.

Accordingly, it is an object of the present invention to provide an LED type backlight unit to make the luminance uniform.

Another object of the present invention is to provide an LED type backlight unit in which the luminance of the LED light source is inclined to the incident surface of the optical panel to be uniform.

In order to achieve the above object, the LED type backlight unit according to the present invention, a direct-emitting LED type including a printed circuit board, an LED light source arranged on the printed circuit board, a diffusion plate disposed on the LED light source A backlight unit, comprising: a plurality of LED light source mounting portions arranged to protrude upward on the printed circuit board, wherein the LED light source mounting portion has a plurality of downwardly inclined sides, and by mounting the LED light sources on the downwardly inclined sides The light emitted from the LED light source is characterized in that the inclined incident on the incident surface of the diffusion plate.

In addition, the LED type backlight unit according to the present invention for achieving the above object, the side-emitting including a printed circuit board, an LED light source arranged on the printed circuit board, a light guide plate disposed transversely to the LED light source An LED type backlight unit, comprising: a plurality of LED light source mounting portions arranged upwardly protruding on the printed circuit board, wherein the LED light source mounting portion has a plurality of downwardly inclined side surfaces and the LED light source on the downwardly inclined side surfaces. By attaching the light emitted from the LED light source is characterized in that the inclined incident on the incident surface of the light guide plate.

Preferably, the inclined downward side of the LED light source mounting portion can form an inclination angle of 30 degrees to 60 degrees with respect to the surface vertical line of the printed circuit board.

Preferably, the LED light source mounting portion, it may be any one formed integrally with the printed circuit board, or formed in combination with the printed circuit board.

According to the present invention, since the LED light source is mounted on the downward inclined side of the LED light source mounting portion arranged on the printed circuit board, the light emitted from the LED light source is obliquely incident on the incident surface of the diffuser plate or the light guide plate to improve the luminance uniformity of the LED type backlight. It is effective to improve.

Hereinafter, an LED type backlight unit according to the present invention will be described in detail with reference to the accompanying drawings.

5 is an exploded perspective view schematically showing a structure of a direct-emitting LED type backlight unit applied to the LED type backlight unit according to the present invention. The same reference numerals are given to parts having the same configuration and operation as those in FIG.

Referring to FIG. 5, the direct-emitting LED type backlight unit 50 applied to the LED type backlight unit according to the present invention includes a printed circuit board 51, an LED light source 52, and a diffusion plate 13. It is composed. In addition, an optical sheet, for example, a diffusion sheet 15, a light collecting sheet 17 composed of a pair of light collecting sheets 17a and 17b, a protective film 19, and the like are sequentially added on the diffusion plate 13. Can be arranged.

Here, the LED light source mounting unit 150 for mounting the LED light source 52 is arranged on the flat surface of the printed circuit board 51, a plurality of, for example, eight arranged in a grid. Of course, the number of the LED light source mounting portions 150 is not limited to eight, and may be two, three, four, five, six, seven, or a plurality of nine or more.

In addition, the side surface of the LED light source mounting portion 150 is composed of a plurality of, for example, four downward inclined side surfaces 151. The upper portion of the LED light source mounting portion 150 is, for example, a flat upper surface 152. Of course, the number of the downward inclined side surfaces 151 is not limited to four but may be three, or a plurality of five or more, and the upper portion of the LED light source mounting portion 150 is not limited to the flat upper surface 152, the inclined surface Or other shapes such as curved surfaces or horns.

In addition, the downwardly inclined side surface 151 forms an angle of inclination of less than 90 degrees, preferably 30 to 60 degrees, with respect to the surface vertical line of the printed circuit board 51, because the intermediate value of the horizontal direction and the vertical direction is typically Is 45 degrees, and it is preferable to provide a margin of about 15 degrees to this value.

Since the size of the LED light source 52 is in the range of 0.1 mm to 4 mm, the downward inclined side surface 151 of the LED light source mounting portion 150 is preferably larger than the size of the LED light source 52. That is, one side of the downward slope side 151 of the LED light source mounting unit 150 is in the range of 0.2 mm to 5 mm, and therefore, the height of the LED light source mounting unit 150 is preferably in the range of 0.2 mm to 2 mm.

 This is because the median in the horizontal and vertical directions is usually 45 degrees, and it is desirable to have a margin of about 15 degrees at this value.

In addition, the LED light source mounting unit 150 may be formed of the same material as the printed circuit board 51 integrally. Of course, the LED light source mounting portion 150 is not limited to the one formed integrally with the printed circuit board 51, and although not shown in the figure, after being manufactured separately from the printed circuit board 51 by a known method and then printed circuit The bottom surface of the LED light source mounting portion 150 may be coupled to a flat upper surface of the substrate 51 by a bonding agent or the like, or may be inserted into a groove portion (not shown) previously formed on the upper surface of the printed circuit board 51. have.

In addition, on the upper surface of the printed circuit board 51 where the LED light source mounting unit 150 is not mounted, the light emitted from the LED light source 52 does not immediately enter the incident surface of the diffuser plate 53 again. In order to enter the incident surface of the diffuser plate 53, a reflective film (not shown) may be disposed to reflect the light to the incident surface of the diffuser plate 53.

On the other hand, as shown in the figure, when the LED light source mounting portion 150 is disposed on a flat surface of the printed circuit board 51, the wiring on the printed circuit board 51 and the wiring on the downward inclined side surface 151 is led It is obvious that the light source 52 should be electrically connected to each other. In addition, although not shown in the drawings, when the LED light source mounting unit 150 is inserted and coupled to the groove (not shown) of the printed circuit board 51, the LED light source mounting unit 150 from the wiring on the bottom surface of the LED light source mounting unit 150 It is apparent that the wiring on the downside slope 151 and the wiring on the downside slope 151 must be electrically connected to the LED light source 52 when connected to the wiring on the downwardly inclined side 151 through the wiring in the interior. to be.

FIG. 6 is a side view of the direct-emitting LED type backlight unit 50 illustrated in FIG. 5 and illustrates intensity of emitted light according to an angle emitted from the LED light source, and FIG. As a side view showing the emission type LED backlight unit 10, it is a view showing the intensity of the emitted light according to the angle emitted from the LED light source. For convenience of explanation, in order to help the description, the diffusion sheet, the light collecting sheet, and the protective film which are disposed on the diffusion plate are not shown in FIGS. 6 and 7.

As shown in FIG. 6, the downwardly inclined side surface 151 of the LED light source mounting unit 150 has an angle of less than 90 degrees, preferably an inclination angle of 30 degrees to 60 degrees with respect to the surface vertical line of the printed circuit board 51. sloped downward at θ), and the LED light sources 52 are mounted on the downwardly inclined side surfaces 151, respectively. Therefore, the intensity of the light 52a emitted in a direction that is 90 degrees with respect to the downwardly inclined side surface 151 is largest, and the light 52b of the light 52b that is emitted in an angle that is less than 90 degrees with respect to the downward slope side 151. The intensity is smaller than the intensity of the light 52a.

Therefore, the light 52a having the greatest intensity is emitted in a direction 90 degrees with respect to the downwardly inclined side surface 151, that is, a direction inclined with respect to the surface of the printed circuit board 51, so that the incident surface of the diffuser plate 53 is provided. Inclination is incident on. As a result, alternating generation of light and dark areas in the diffusion plate 53 can be prevented.

Therefore, the LED type backlight unit 50 of the present invention can provide a uniform luminance, for example, to the LCD panel by suppressing the luminance smear phenomenon in which bright areas and dark areas are alternately formed on the diffusion plate. In addition, since the distance between the LED light source and the diffusion plate can be narrowed, it is possible to realize a thin direct-emitting LED type backlight unit. In addition, by increasing the luminance uniformity, the number of optical films required for the LED type backlight may be reduced.

In contrast, conventionally, as shown in FIG. 7, the LED light source 12 is mounted on a flat surface of the printed circuit board 11. Therefore, the intensity of the light 12a emitted in the direction of 90 degrees with respect to the surface of the printed circuit board 11 is the largest, and the light emitted in the direction of the angle less than 90 degrees with respect to the surface of the printed circuit board 50 The intensity of 12b is smaller than the intensity of light 12a.

Therefore, since the light 12a having the greatest intensity is emitted in a direction perpendicular to the surface of the printed circuit board 51, the light 12a is incident perpendicularly to the incident surface of the diffusion plate 53. As a result, the bright region 13a and the dark region 13b are alternately formed in the diffusion plate 13.

Therefore, in the conventional LED type backlight unit 10, it is difficult to suppress luminance smears in which bright areas and dark areas are alternately formed on the diffusion plate, and thus, for example, cannot provide uniform brightness to the LCD panel. In addition, since the distance between the LED light source and the diffusion plate can not be narrowed, it is impossible to realize a thin direct-emitting LED type backlight unit.

On the other hand, in the present invention has been described by applying the LED light source mounted on the down-tilt side of the LED light source mounting portion arranged on the printed circuit board to the LED type backlight unit, the screen of uniform brightness, such as display panel, display board, billboard, signage It can be applied to various required applications. In addition, the backlight with a composite sheet can be applied to indoor and outdoor lighting.

8 is a plan view schematically showing the structure of the side-emitting LED type backlight unit applied to the LED type backlight unit according to the present invention, showing the intensity of the emitted light according to the angle emitted from the LED light source. Parts having the same configuration and operation as those in Fig. 2 are given the same reference numerals. For convenience of explanation, in order to help the description, the diffusion sheet, the light collecting sheet, the protective film, the reflecting plate, and the reflecting sheet are not shown in FIG. 8.

Referring to FIG. 8, the side emitting type LED type backlight unit 60 applied to the LED type backlight unit according to the present invention includes a printed circuit board 61, an LED light source 62, an LED light source mounting unit 160, and a light guide plate ( 63). In addition, an optical sheet, for example, a diffusion sheet 25, a light collecting sheet 27 composed of a pair of light collecting sheets 27a and 27b, a protective film 29, and the like are sequentially disposed on the light guide plate 63. Can be.

The printed circuit board 61, the LED light source 62, and the LED light source mounting unit 160 may include the printed circuit board 51, the LED light source 52, and the LED light source illustrated in FIGS. 5 and 6 (a). Since the structure and action similar to the mounting portion 150 will be omitted for this structure and action.

In the side-emitting type LED backlight unit 60 having such a structure, as shown in FIG. 8, the downwardly inclined side surface 151 of the LED light source mounting unit 160 is perpendicular to the surface vertical line of the printed circuit board 61. Inclined downward at an angle smaller than 90 degrees, preferably 30 degrees to 60 degrees, the LED light sources 62 are mounted on the downwardly inclined side surfaces 161, respectively. Therefore, the intensity of the light 62a emitted in the direction that is 90 degrees with respect to the downwardly inclined side surface 161 is greatest, and the light 62b emitted in the direction that becomes an angle smaller than 90 degrees with respect to the downwardly inclined side surface 161. The intensity is smaller than the intensity of the light 62a.

Therefore, the light 62a having the greatest intensity is emitted in a direction 90 degrees with respect to the downwardly inclined side surface 161, that is, in a direction inclined with respect to the surface of the printed circuit board 61. Inclined incident. As a result, the occurrence of alternating bright and dark areas near the incident surface of the light guide plate 63 can be prevented.

Therefore, the LED type backlight unit 60 of the present invention can suppress the luminance stain caused by alternating light and dark areas in the light guide plate, thereby providing uniform brightness to the LCD panel, for example, There is an effect of increasing the effective area of the. In addition, by increasing the luminance uniformity, the number of optical films required for the LED type backlight unit may be reduced.

Meanwhile, the present invention has been described in connection with the above-mentioned preferred embodiments, but various substitutions, changes, or modifications are possible without departing from the spirit and scope of the present invention. Therefore, the claims of the present invention should not be limited to the description of the preferred embodiment and the drawings, but should include such substitutions, changes, or modifications belonging to the gist of the present invention.

1 is an exploded perspective view showing a direct-emitting LED type backlight unit applied to a conventional LED type backlight unit.

Figure 2 is an exploded perspective view showing a side emitting type LED type backlight unit applied to a conventional LED type backlight unit.

FIG. 3 is a side view of the direct-emitting LED type backlight unit illustrated in FIG. 1. FIG. 3A illustrates diffusion when the distance between the LED light source and the diffuser is farther than the distance between adjacent LED light sources. FIG. 3B illustrates an example in which luminance spots are generated in the diffuser plate when the distance between the LED light source and the diffuser plate is shorter than a distance between adjacent LED light sources. The figure shown.

FIG. 4 is a side view illustrating the side-emitting type LED backlight unit illustrated in FIG. 2, in which a luminance spot is generated on the light guide plate when the distance between the LED light source and the light guide plate is shorter than the distance between adjacent LED light sources. .

5 is an exploded perspective view schematically showing the structure of a direct-emitting LED type backlight unit of the LED type backlight unit according to the present invention.

FIG. 6 is a side view of the direct-emitting LED type backlight unit illustrated in FIG. 5 and illustrates intensity of emitted light according to an angle emitted from the LED light source.

FIG. 7 is a side view illustrating the direct-emitting LED type backlight unit illustrated in FIG. 1 and illustrates the intensity of emitted light according to the angle emitted from the LED light source.

8 is a plan view schematically showing the structure of the side-emitting LED type backlight unit applied to the LED type backlight unit according to the present invention, showing the intensity of the emitted light according to the angle emitted from the LED light source.

     *** Explanation of symbols for the main parts of the drawing ***

10,20,50,60: backlight unit (BLU) 11,21,51,61: printed circuit board

12,22,52,62: LED light source 13: diffuser plate

13a: hot spot 13b: dark zone

15,25: Diffusion sheet

17,17a, 17b, 27,27a, 27b: Condensing sheet

19,29: protective film 23: light guide plate

23a: incident surface 23b: right side

23c: hot spot 23b: dark zone

23e: luminance spot

24: Reflector 26: Reflective Sheet

150, 160: LED light source mounting portion

151, 161: downward slope side 153, 163: upper side

Claims (5)

In the direct-emitting type LED backlight unit comprising a printed circuit board, an LED light source arranged on the printed circuit board, a diffusion plate disposed on the LED light source, It includes a plurality of LED light source mounting portion arranged to protrude upward on the printed circuit board, The LED light source mounting portion has a plurality of downwardly inclined side surface, by mounting the LED light source on the downwardly inclined side LED light, characterized in that the incident light incident from the LED light source to the incident surface of the diffuser plate obliquely unit. In the side-emitting type LED backlight unit comprising a printed circuit board, an LED light source arranged on the printed circuit board, a light guide plate disposed transversely to the LED light source, It includes a plurality of LED light source mounting portion arranged to protrude upward on the printed circuit board, The LED light source mounting unit has a plurality of downwardly inclined side surface, by mounting the LED light source on the downward inclined side LED type backlight unit characterized in that obliquely incident light emitted from the LED light source to the incident surface of the light guide plate. . The LED type backlight unit of claim 1 or 2, wherein the downward inclination side of the LED light source mounting unit forms an inclination angle of 30 degrees to 60 degrees with respect to the vertical line of the surface. The LED type backlight unit of claim 3, wherein the height of the LED light source mounting unit is 0.2 mm to 2 mm. The LED type backlight unit of claim 1 or 2, wherein the LED light source mounting unit is one formed integrally with the printed circuit board or combined with the printed circuit board.
KR1020090119240A 2009-12-03 2009-12-03 Led type backlight unit KR20110062498A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
KR1020090119240A KR20110062498A (en) 2009-12-03 2009-12-03 Led type backlight unit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
KR1020090119240A KR20110062498A (en) 2009-12-03 2009-12-03 Led type backlight unit

Publications (1)

Publication Number Publication Date
KR20110062498A true KR20110062498A (en) 2011-06-10

Family

ID=44396669

Family Applications (1)

Application Number Title Priority Date Filing Date
KR1020090119240A KR20110062498A (en) 2009-12-03 2009-12-03 Led type backlight unit

Country Status (1)

Country Link
KR (1) KR20110062498A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20130142298A (en) * 2012-06-19 2013-12-30 희성전자 주식회사 Direct type back light unit

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20130142298A (en) * 2012-06-19 2013-12-30 희성전자 주식회사 Direct type back light unit

Similar Documents

Publication Publication Date Title
US8366308B2 (en) Backlight module
CN101097349B (en) Backlight assembly and liquid crystal display device having the same
US8684587B2 (en) Backlight unit
CN101975361B (en) Side lighting type backlight module
JP5509154B2 (en) Light emitting device and display device
CN102518988B (en) Backlight module
KR20080013739A (en) Liquid crystal display device
JP2007066634A (en) Backlight device, and liquid crystal display device
TWI420202B (en) Edge-type backlight module
CN102705744A (en) Light emitting diode (LED) lamp strip and lateral-entering type backlight module using same
KR20130014224A (en) Backlight unit and display system
KR20110064743A (en) Backlight unit and liquid crystal display device having the same
CN101832517B (en) Back light module
US8398286B2 (en) Backlight module for liquid crystal display
JP2012248769A (en) Light-emitting device and display device
WO2012141098A1 (en) Lighting device and display device
WO2012026164A1 (en) Illumination device and display device
US9405149B2 (en) Direct backlight module
KR101255282B1 (en) prism sheet and back light unit and liquid crystal display device using the same
JP5985364B2 (en) Light source unit and lighting device
US8646928B2 (en) Backlight module and liquid crystal display apparatus
JP2009099270A (en) Hollow surface lighting device
JP5203462B2 (en) Light source module and electronic device including the same
KR20110062498A (en) Led type backlight unit
US9823412B2 (en) Edge type backlight module and liquid crystal display device

Legal Events

Date Code Title Description
A201 Request for examination
E902 Notification of reason for refusal
E601 Decision to refuse application