WO2024004557A1 - Système d'affichage vidéo flottante spatiale - Google Patents

Système d'affichage vidéo flottante spatiale Download PDF

Info

Publication number
WO2024004557A1
WO2024004557A1 PCT/JP2023/021189 JP2023021189W WO2024004557A1 WO 2024004557 A1 WO2024004557 A1 WO 2024004557A1 JP 2023021189 W JP2023021189 W JP 2023021189W WO 2024004557 A1 WO2024004557 A1 WO 2024004557A1
Authority
WO
WIPO (PCT)
Prior art keywords
light
image
display system
floating
light source
Prior art date
Application number
PCT/JP2023/021189
Other languages
English (en)
Japanese (ja)
Inventor
浩二 平田
智貴 山本
寿紀 杉山
Original Assignee
マクセル株式会社
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 マクセル株式会社 filed Critical マクセル株式会社
Publication of WO2024004557A1 publication Critical patent/WO2024004557A1/fr

Links

Images

Classifications

    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B30/00—Optical systems or apparatus for producing three-dimensional [3D] effects, e.g. stereoscopic images
    • G02B30/50—Optical systems or apparatus for producing three-dimensional [3D] effects, e.g. stereoscopic images the image being built up from image elements distributed over a 3D volume, e.g. voxels
    • G02B30/56—Optical systems or apparatus for producing three-dimensional [3D] effects, e.g. stereoscopic images the image being built up from image elements distributed over a 3D volume, e.g. voxels by projecting aerial or floating images
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/12—Reflex reflectors
    • G02B5/122—Reflex reflectors cube corner, trihedral or triple reflector type
    • G02B5/124—Reflex reflectors cube corner, trihedral or triple reflector type plural reflecting elements forming part of a unitary plate or sheet

Definitions

  • the present invention relates to a spatial floating video display system.
  • Patent Document 1 As spatial floating image display systems, image display devices that display images directly to the outside and display methods that display images as a spatial screen are already known. Furthermore, a retroreflective member that displays an aerial image is disclosed in Patent Document 1, for example. Further, for example, it is disclosed in Patent Document 2.
  • An object of the present invention is to provide a technology capable of displaying a spatially floating image with high visibility (visual resolution and contrast) and high color reproducibility in a spatially floating image display system or a spatially floating image display device. .
  • a space floating video display system as an example of the present application includes a display panel for displaying a video, a light source device for the display panel, a space floating video that reflects video light from the display panel, and creates a real space floating video in the air using the reflected light.
  • the retroreflective member includes a retardation plate, the retardation plate has reverse wavelength dispersion, and is disposed on the image light incident surface side of the retroreflection member.
  • a high-quality video display with improved color reproducibility of the displayed spatial floating video can be achieved in a spatial floating video display system. It is possible to realize a spatially floating video display device that is capable of Problems, configurations, and effects other than those described above will be made clear by the description of the embodiments below.
  • FIG. 2 is a diagram showing the configuration of a retroreflective member and the generation position of a spatially floating image according to an embodiment of the present invention.
  • FIG. 2 is a diagram showing the configuration of a retroreflective member and the generation position of a spatially floating image according to an embodiment of the present invention.
  • FIG. 2 is a diagram showing the configuration of a retroreflective member and the generation position of a spatially floating image according to an embodiment of the present invention. It is an explanatory view for explaining the characteristic of the optical member which constitutes the retroreflection member concerning one example of the present invention.
  • 1 is a structural diagram showing an example of a specific configuration of a light source device according to an embodiment of the present invention.
  • FIG. 3 is a perspective view, a top view, and a cross-sectional view showing an example of a specific configuration of a light source device. It is a characteristic diagram showing the emission spectrum of a general white LED light source.
  • FIG. 3 is a characteristic diagram showing the reflection characteristics of a reflector according to an embodiment of the present invention.
  • FIG. 3 is a characteristic diagram showing the reflection characteristics of a light guide according to an embodiment of the present invention.
  • It is a characteristic diagram showing the spectral transmittance of a general polarizing plate.
  • FIG. 2 is a characteristic diagram showing the spectral transmittance of a polarizing plate used in a liquid crystal panel.
  • FIG. 3 is a cross-sectional view showing the configuration of a polarizing plate.
  • FIG. 2 is a chromaticity diagram showing chromaticity when displaying white in a floating image display device according to an embodiment of the present invention.
  • FIG. 2 is a chromaticity diagram in which a MacAdam color discrimination ellipse is superimposed on a chromaticity diagram showing chromaticity when displaying white in a floating image display device according to an embodiment of the present invention.
  • FIG. 7 is a structural diagram showing another example of a specific configuration of a light source device of another type.
  • FIG. 7 is a diagram illustrating a part of another example of a specific configuration of a light source device of another type.
  • FIG. 7 is a diagram illustrating a part of another example of a specific configuration of a light source device of another type.
  • FIG. 7 is a diagram illustrating a part of another example of a specific configuration of a light source device of another type.
  • FIG. 7 is a diagram illustrating a part of another example of a specific configuration of a light source device of another type.
  • FIG. 7 is a structural diagram showing another example of a specific configuration of a light source device of another type.
  • FIG. 7 is a diagram illustrating another example of a specific configuration of a light source device of another type. It is an enlarged view which shows the surface shape of the light guide diffuser part of another example of the specific structure of a light source device.
  • FIG. 2 is a cross-sectional view showing an example of a specific configuration of a light source device.
  • FIG. 2 is a structural diagram showing an example of a specific configuration of a light source device.
  • FIG. 2 is a perspective view and a top view showing an example of a specific configuration of a light source device.
  • FIG. 1 is a diagram illustrating a part of another example of a specific configuration of a light source device of another type.
  • FIG. 7 is a structural diagram showing another example of a specific configuration of a
  • FIG. 3 is an explanatory diagram for explaining the diffusion characteristics of the video display device.
  • FIG. 3 is an explanatory diagram for explaining the diffusion characteristics of the video display device.
  • FIG. 3 is an explanatory diagram for explaining light source diffusion characteristics of a video display device.
  • FIG. 3 is a diagram showing a coordinate system for measuring visual characteristics of a liquid crystal panel.
  • FIG. 2 is a diagram showing brightness angle characteristics (longitudinal direction) of a general liquid crystal panel.
  • FIG. 3 is a diagram showing the brightness angle characteristics (in the lateral direction) of a general liquid crystal panel.
  • FIG. 2 is a diagram showing contrast angle characteristics (longitudinal direction) of a general liquid crystal panel.
  • FIG. 3 is a diagram showing contrast angle characteristics (lateral direction) of a general liquid crystal panel.
  • the present disclosure transmits an image of image light from a large-area image light source through a transparent member that partitions a space, such as glass in a show window, and floats the image inside or outside of a store (space).
  • the present invention relates to a display system that can display images.
  • the present disclosure also relates to a large-scale digital signage system configured using a plurality of such display systems.
  • the following embodiments it is possible to display high-resolution images floating in space, for example, on the glass surface of a show window or on a light-transmitting board.
  • the divergence angle of the emitted image light small, that is, an acute angle, and aligning it with a specific polarization, it is possible to efficiently reflect only the normal reflected light to the retroreflection member.
  • the transmittance or reflectance of the light source device, the liquid crystal display panel for image display, and the retroreflective member are set within a predetermined range, and the divergence angle of the light flux incident on the liquid crystal display panel from the light source device is controlled.
  • the color reproducibility of the entire system is improved by adjusting the wavelength of the image light flux that is emitted from the lens and reflected by the retroreflective member. For this reason, the light utilization efficiency is high, and the color reproducibility of spatially floating images, which has become a new issue with conventional retroreflection methods, can be improved and clear spatially floating images can be obtained.
  • the device and optical system including the light source of the present disclosure it is possible to provide a novel and highly usable spatial floating image display system that can significantly reduce power consumption.
  • an organic EL panel or a liquid crystal display panel (liquid crystal panel or display panel) is combined with a retroreflective member as a high-resolution color display image source.
  • the surface of the first retroreflective member 2 used in a conventional space-floating video display device using a liquid crystal panel capable of using video light of a specific polarization as a video display element has a reflective surface made of a polyhedron as shown in FIG. 1B. A surface is formed.
  • the retroreflective member 2 includes a reflective layer 2a, a transparent base material 2b, a reflective surface 2c, and a ⁇ /4 plate 2d, which is a retardation plate having reverse wavelength dispersion characteristics.
  • the retroreflective member includes, in order from the image light incident surface side of the retroreflective member, a retardation plate 2d having reverse wavelength dispersion characteristics, a transparent base material 2b, a reflective layer 2a, a transparent base material 2b, and a reflective surface 2c. configured.
  • the retardation plate may be made of polycarbonate material.
  • the reflective layer 2a is filled with a material having a refractive index close to that of the reflective layer 2a, and is sandwiched between the transparent base materials 2b to obtain the necessary mechanical strength.
  • a ⁇ /4 plate 2d is arranged on the image light incident surface, and the image light is reflected by the reflecting surface 2c and twice by the retroreflective member, thereby forming retroreflected light. That is, the light incident on the retroreflective member 2 is incident on the retardation plate 2d having reverse wavelength dispersion characteristics, passes through the transparent base material 2b and the reflective layer 2a, is reflected on the reflective surface 2c, and is reflected by the transparent base material 2b. 2b, the light passes through the reflective layer 2a, and enters the retardation plate 2d again.
  • the ⁇ /4 plate used as a retardation plate is obtained by stretching a polycarbonate base material to a desired thickness.
  • the thickness of the stretched base material is determined based on 137.5 nm, which is 1/4 of 550 nm, which has a high relative luminous efficiency.
  • the inventors selected a ⁇ /4 plate using color reproducibility as a new evaluation index.
  • FIG. 2 is a characteristic diagram showing the characteristics of a typical commercially available ⁇ /4 plate.
  • the color reproducibility of spatially floating images was evaluated using samples with different partial dispersions based on 550 nm light.
  • a ⁇ /4 plate with positive wavelength dispersion which is made by stretching a normal polycarbonate base material with respect to the ideal line of partial dispersion, has insufficient phase correction amount for light in the blue region below 470 nm, and the efficiency of polarization conversion decreases significantly. .
  • the color becomes white with a yellowish tinge.
  • the light source used in the light source device of the present invention shown in FIGS. 3 and 4 has a configuration in which a surface-emitting white LED emits yellow phosphor using a blue LED as excitation light and synthesizes the light to emit white light.
  • Figure 5 shows the emission spectrum.
  • characteristics (a) and (a) having reverse wavelength dispersion characteristics in the blue-green and blue regions are required.
  • the characteristic that allows the chromaticity of the spatially floating image of white display to move toward a higher color temperature and a more vivid white display is possible is that the peak wavelength of the blue region of the light source light of the white LED is shorter than 450 nm.
  • the sample with smaller wavelength dispersion on the wavelength side was better, and the sample with characteristic (a) showed better performance.
  • the wavelength dispersion on the long wavelength side is close to the ideal curve, which improves the color development of red image light.
  • the priority order for selecting the ⁇ /4 plate 2d placed in front of the reflective retroreflective member used in the floating image display device whose cross-sectional structure is shown in Figure 1C is as follows: (1) wavelength dispersion is ideally linear; (2) The smaller the wavelength dispersion, especially in the blue region, than the ideal straight line, the more effective it is (3) Further improving the color reproducibility of the entire system. For this purpose, it is better to make the wavelength dispersion in the red region and the long wavelength region of 650 nm or more closer to an ideal straight line.
  • FIG. 1 is a diagram illustrating an example of the form of a reflexive optical system used to realize the spatially floating image display system of the present disclosure. Further, FIG. 1 is a diagram illustrating the overall configuration of a spatial floating video display system in this embodiment.
  • this system when the spatial floating video display system is placed on a desk for the viewer of the spatial floating video. You will be able to look down at the images floating in space.
  • the imaging position (angle) of the spatially floating image is determined between the display surface of the liquid crystal display panel 11, the reflective polarizing plate 101 that functions as a beam splitter that reflects image light of a specific polarization, and the retroreflective member 2. Determined by placement and angle.
  • the spatially floating image is formed at a plane-symmetrical position on the retroreflective member 2 with the reflective polarizing plate 101 as the plane of symmetry.
  • the light source device 13 of the liquid crystal display panel 11 performs retroreflection as a directional characteristic with a narrow divergence angle in order to reduce the occurrence of ghost images (indicated by g1 and g2 in the figure).
  • the generation of ghost images is suppressed by reducing diffused light other than normal light.
  • an image light control sheet 12 for controlling the diffusion characteristics of image light is provided on or loosely adjacent to the light exit surface of the liquid crystal display panel 11. As a result, the occurrence of ghost images can be significantly reduced.
  • Image light 5001 of a specific polarization from the image display device 1 is reflected by a reflective polarizing plate 101 that functions as a polarizing beam splitter provided on the light incident surface of the transparent plate 100, and the reflected light 5002 is reflected by a retroreflective member.
  • a ⁇ /4 plate 2d is provided as a retardation plate on the surface of the retroreflection member 2, and when the retroreflection light passes through it twice, it acts equivalently as a ⁇ /2 plate, so that the retroreflection light 5003 is polarized as described above.
  • a spatially floating image is formed at a position with the reflective polarizing plate 101 as the axis of symmetry.
  • an absorptive polarizing plate 102 is provided between the transparent plate 100 and the reflective polarizing plate 101 to transmit polarized image light that has undergone polarization conversion. It's okay.
  • FIG. 8 shows the spectral transmittance of a general absorptive polarizing plate provided in the transparent plate 100 described above. Since the transmittance in the blue-green wavelength region of 500 nm or less is lower than the transmittance in the long wavelength region of 550 nm or more, the absorption in the blue region of the white LED emission spectrum shown in FIG. 5 is large, resulting in the chromaticity diagram shown in FIG. 10. The color temperature of white shifts to the lower temperature side along the blackbody locus, and the color reproduction range becomes narrower.
  • FIG. 8 shows the spectral transmittance of a general absorptive polarizing plate provided in the transparent plate 100 described above. Since the transmittance in the blue-green wavelength region of 500 nm or less is lower than the transmittance in the long wavelength region of 550 nm or more, the absorption in the blue region of the white LED emission spectrum shown in FIG. 5 is large, resulting in the chromaticity diagram shown in FIG. 10. The color temperature of white shifts to
  • FIG. 9 shows the structure of a general absorption type polarizing plate, in which a PVA film is stretched in a specific direction and dyed with dye to control the polarization characteristics for specific polarized waves. Since PVA (polyvinyl alcohol) is highly hydrophilic, it is sandwiched between TAC (tri acetyl cellulose) films on both sides to suppress moisture absorption. When the degree of polarization (transmission axis transmittance/absorption axis transmittance) of a dye that controls polarization characteristics is improved, the absorption of short wavelengths of 500 nm or less increases.
  • image light of a specific polarization is provided on a transparent plate 100 provided in a window through which image light passes for forming a spatial floating image on the outside of the set.
  • the absorptive polarizing sheet 102 that selectively transmits has a property of transmitting image light of a specific polarization, so the image light of a specific polarization is transmitted through the absorptive polarizing sheet 102 .
  • a real spatially floating image 220 is formed at a symmetrical position with respect to the retroreflective member 2 by the transmitted image light.
  • the light forming the airborne image 220 obtained by the airborne image display device of the present disclosure is a collection of light rays that converge from the retroreflective member 2 to the optical image of the airborne image 220. After passing the optical image of the image 220, it continues straight ahead. Therefore, the floating image 220 is a highly directional image, unlike the diffused image light formed on a screen by a general projector.
  • FIG. 11 shows a chromaticity diagram showing the chromaticity when displaying white in a spatially floating image display device.
  • FIG. 12 shows a chromaticity diagram in which MacAdam's color discrimination ellipse is superimposed on a chromaticity diagram showing chromaticity when displaying white in a spatially floating image display device.
  • the sensitivity of each coordinate area to human visual chromaticity changes (CIE's XY chromaticity coordinate system) is the area recognized as the same color based on the amount of deviation from the center point of the ellipse on the XY chromaticity coordinates shown in Figures 11 and 12. It is represented by Mac Adam's isochromatic ellipse.
  • the higher the color temperature the higher the sensitivity for recognizing subtle changes in chromaticity, so great care will be needed when using bright white as the base color in order to expand the color reproduction range of spatial floating images in the future.
  • the reflective polarizing plate used, the transmissive polarizing plate, and the blue-green wavelength of 500 nm or less of the transmissive polarizing plate bonded to the liquid crystal display panel Since the spectral transmittance in the wavelength region is lower than that in the green-red region, the ⁇ /4 plate bonded to the surface of the reflective retroreflective member used in the examples of the present invention has reverse wavelength dispersion characteristics. This is essential to ensure white reproducibility.
  • the floating image 220 when the user views the image 220 floating in the air from the direction shown in the figure, the floating image 220 is viewed as a bright image; , the floating image 220 cannot be viewed as an image at all.
  • This characteristic is very suitable for use in a system that displays images that require high security or highly confidential images that should be kept secret from the person directly facing the user.
  • the polarization axes of the reflected image light may become uneven. In this case, some of the image light whose polarization axes are not aligned is absorbed by the above-mentioned absorptive polarizing sheet 102. Therefore, unnecessary reflected light is not generated in the retroreflective optical system, and deterioration in the image quality of the spatially floating image can be prevented or suppressed.
  • the display screen of the image display device 1 is shielded from light by the reflective surface of the retroreflective member 2. be done. Therefore, in this spatial floating image display device, compared to a case where the image display device 1 and the retroreflective member face each other directly, the displayed image is difficult to see directly because the image display device 1 is placed on the viewing side. Become.
  • a depolarization element 103 that optically converts a part of the image light of a specific polarization into the other polarization and converts it into pseudo natural light. It's okay. As a result, even if the viewer is wearing polarized sunglasses, a good spatial floating image can be viewed. When optically bonded to the transparent plate 100 using an adhesive, no light reflecting surface is generated and the quality of the spatial floating image is not impaired.
  • the video display device 1 includes a light source device 13 that generates light of a specific polarization having a diffusion characteristic that is narrow to the liquid crystal display panel 11.
  • a video light control sheet is provided on the video light output surface of the liquid crystal display panel 11.
  • the image light control sheet 12 adjusts the emission direction and divergence angle of the image light flux emitted from the liquid crystal display panel 11.
  • a viewing angle control film (VCF) manufactured by Shin-Etsu Polymer Co., Ltd. is suitable as this image light control sheet, and its structure is such that transparent silicon and black silicon are arranged alternately, and a synthetic resin is arranged on the light input/output surface. Since it has a sandwich structure, the same effects as the external light control film of this example can be expected.
  • the viewing angle control film (VCF) is composed of transparent silicon and black silicon that are arranged alternately in a predetermined direction, so that the viewing angle control film (VCF) controls the image light in the vertical direction of the pixel arrangement direction of the liquid crystal display panel 11. It is preferable to arrange the transparent silicon and the black silicon of the sheet 12 so that the stretching direction thereof is tilted to reduce moiré that occurs at the pitch between the pixels and the external light control film.
  • One pixel of the liquid crystal panel 11 is made up of pixels of three colors RGB arranged in parallel, and is generally square, so the occurrence of the above-mentioned moiré cannot be suppressed over the entire screen. For this reason, the tilted arrangement shown in (1) is optimized within a range of 5 degrees to 25 degrees so that the position where moiré occurs can be intentionally shifted to a place where the floating image is not displayed. We experimentally determined what we should do.
  • the moire that occurs between the retroreflective member 2 and the image light control sheet 12 is caused by the fact that they are striated structures, and the image light
  • the control sheet By optimally tilting the control sheet in relation to the pixel arrangement of the liquid crystal panel, it is possible to reduce large, low-frequency moiré that is visible to the naked eye.
  • the image light control sheet 12 is placed on the image light emitting surface of the liquid crystal panel 11 as shown in FIG. 1, and is adhesively fixed to the image light emitting surface of the liquid crystal panel 11 using an adhesive material. Furthermore, the diffusion angle and direction of the image light beam diffused from the spatially floating image are adjusted by the diffusion characteristics of the image light control sheet 12 and the diffusion characteristics of the light source device 13.
  • the diffusion property of the image light control sheet 12 is that transparent silicon and black silicon extending in a predetermined direction are arranged alternately. By tilting the stretching direction of the transparent silicone and black silicone No. 12, moiré that occurs at the pitch between the pixels and the external light control film is reduced.
  • the diffusion characteristics of the light source device 13 can be improved by configuring the reflective surface 307 provided on the reflective light guide 306 shown in FIG. 13B (2) so that one surface has multiple inclinations.
  • the goal is to adjust the reflected light with high precision.
  • the region used as the reflective surface may be a plurality of surfaces, a polysurface, or a curved surface.
  • the parallel light beam ⁇ 5 (R7 to R10) from the reflector 300 is reflected by a plurality of surfaces (P7 to P10) with different inclinations in the direction of travel, and a corresponding one is formed on each surface. Head to the LCD panel section.
  • the contrast performance in the transverse (vertical) direction of the panel is excellent in the range of -15 degrees to +15 degrees, as shown in Figure 26, and when combined with the brightness characteristics, the contrast performance is excellent in the range of -15 degrees to +15 degrees, with a range of ⁇ 10 degrees around 5 degrees. The best properties will be obtained if used within this range.
  • the characteristics of brightness and viewing angle in the longitudinal (left and right) direction of the panel are excellent at the emission angle perpendicular to the panel surface (emission angle of 0 degrees).
  • the reason for this is that the characteristic of twisting light in the longitudinal direction (horizontal direction) of the liquid crystal panel becomes 0 degrees when the applied voltage is maximum.
  • the contrast performance in the longitudinal (left and right) direction of the panel is excellent in the range of -5 degrees to -10 degrees, as shown in Figure 25, and when combined with the brightness characteristics, the contrast performance in the longitudinal (left and right) direction of the panel is excellent in the range of -5 degrees to -10 degrees.
  • the best properties will be obtained if used within this range.
  • the output angle of the image light emitted from the liquid crystal panel is determined by making the light enter the liquid crystal panel from the direction in which the most excellent characteristics can be obtained using the light beam direction conversion means provided in the light guide of the light source device 13 described above, and Light modulation using signals improves the image quality and performance of the video display device 1.
  • the light source After being incident on the liquid crystal panel 11 at an incident angle that maximizes the characteristics of the liquid crystal panel 11, the device 13 emits an image beam whose brightness is modulated in accordance with the image signal toward the retroreflective member.
  • the device 13 In order to reduce the set volume of the spatially floating video display system, it is desired to increase the degree of freedom in the arrangement of the liquid crystal panel 11 and the retroreflective member.
  • the following technical means are used.
  • a transparent sheet made of an optical component such as a linear Fresnel lens is provided on the image display surface of the liquid crystal panel 11 as a light direction conversion panel to control the exit direction of the incident light beam to the retroreflective optical member while providing high directivity. to determine the imaging position of the spatially floating image.
  • the image light from the image display device 1 efficiently reaches the viewer with high directivity (straightness) like laser light, and as a result, a high-quality floating image can be displayed with high quality. It is possible to display images with high resolution and to significantly reduce power consumption by the video display device 1 including the light source device 13.
  • FIG. 17 shows another example of a specific configuration of the video display device 1.
  • the light source device 13 in FIG. 17 is similar to the light source device in FIG. 17 and the like.
  • the light source device 13 is configured by housing an LED, a collimator, a synthetic diffusion block, a light guide, etc. in a case made of plastic, for example, and has a liquid crystal display panel 11 attached to its upper surface.
  • LED (Light Emitting Diode) elements 14a and 14b which are semiconductor light sources, and an LED board on which their control circuits are mounted are attached, and on the outer side of the LED board, A heat sink, which is a member for cooling the heat generated by the LED elements and the control circuit, is attached (not shown).
  • the liquid crystal display panel frame attached to the top surface of the case includes the liquid crystal display panel 11 attached to the frame and an FPC (Flexible Printed Circuits) electrically connected to the liquid crystal display panel 11. ) (not shown), etc. are attached. That is, the liquid crystal display panel 11 that is a liquid crystal display element, together with the LED elements 14a and 14b that are solid-state light sources, adjusts the intensity of transmitted light based on a control signal from a control circuit (not shown here) that constitutes an electronic device. A display image is generated by modulating the .
  • FPC Flexible Printed Circuits
  • each of the collimators 15 is made of a translucent resin such as acrylic.
  • this collimator 15 has an outer circumferential surface 156 with a conical convex shape obtained by rotating a parabolic cross section, and the center of the collimator 15 at its top (the side in contact with the LED board). It has a concave portion 153 in which a convex portion (that is, a convex lens surface) 157 is formed.
  • the collimator 15 has a convex lens surface (or a concave lens surface recessed inward) 154 that protrudes outward at the center of the plane portion (the side opposite to the above-mentioned top portion).
  • the paraboloid 156 forming the conical outer circumferential surface of the collimator 15 is set within an angular range that allows total internal reflection of the light emitted from the LEDs 14a and 14b in the peripheral direction, or A reflective surface is formed.
  • the LEDs 14a and 14b are each placed at a predetermined position on the surface of the board 102, which is the circuit board.
  • This substrate 102 is arranged and fixed to the collimator 15 so that the LEDs 14a or 14b on the surface thereof are located at the center of the recess 153, respectively.
  • the light emitted upward (to the right in the figure) from the central portion of the collimator 15 has an outer shape.
  • the two convex lens surfaces 157 and 154 converge the light into parallel light.
  • light emitted from other parts toward the periphery is reflected by the paraboloid that forms the conical outer peripheral surface of the collimator 15, and is similarly condensed into parallel light.
  • the collimator 15 having a convex lens in its center and a paraboloid in its periphery, it is possible to extract almost all of the light generated by the LED 14a or 14b as parallel light. , it becomes possible to improve the utilization efficiency of the generated light.
  • a polarization conversion element 21 is provided on the light output side of the collimator 15.
  • the polarization conversion element 21 may also be referred to as a polarization conversion member.
  • this polarization conversion element 21 consists of a columnar (hereinafter referred to as a parallelogram column) translucent member having a parallelogram cross section and a columnar member (hereinafter referred to as a parallelogram column) having a triangular cross section. , triangular prism), and are arranged in a plurality in an array parallel to a plane perpendicular to the optical axis of the parallel light from the collimator 15.
  • polarizing beam splitters (hereinafter abbreviated as "PBS films”) 211 and reflective films 212 are alternately provided at the interfaces between adjacent light-transmitting members arranged in an array. Further, a ⁇ /2 phase plate 213 is provided on the exit surface from which the light that has entered the polarization conversion element 21 and passed through the PBS film 211 exits.
  • the output surface of this polarization conversion element 21 is further provided with a rectangular synthetic diffusion block 16, which is also shown in FIG. 17(a). That is, the light emitted from the LED 14a or 14b becomes parallel light due to the action of the collimator 15, enters the composite diffusion block 16, is diffused by the texture 161 on the exit side, and then reaches the light guide 17.
  • the light guide 17 is a rod-shaped member with a substantially triangular cross section (see FIG. 17(b)) made of a translucent resin such as acrylic, and as is clear from FIG.
  • a light guide light emitting portion (surface) 173 is provided, which faces the liquid crystal display panel 11, which is a liquid crystal display element, through the plate 18b.
  • the light guide light reflecting portion (surface) 172 of the light guide 17 has a large number of reflecting surfaces 172a and connecting surfaces 172b arranged in an alternating sawtooth shape. It is formed.
  • the reflective surface 172a (line segment sloping upward to the right in the figure) forms ⁇ n (n: a natural number, for example, 1 to 130) with respect to the horizontal plane indicated by the dashed line in the figure.
  • ⁇ n is set to 43 degrees or less (however, 0 degrees or more).
  • the light guide entrance portion (surface) 171 is formed in a curved convex shape inclined toward the light source side. According to this, the parallel light from the output surface of the composite diffusion block 16 is diffused and incident through the first diffusion plate 18a, and as is clear from the figure, the light guide entrance part (surface) 171 As a result, the light is slightly bent (deflected) upward and reaches the light guide light reflecting portion (surface) 172, where it is reflected and reaches the liquid crystal display panel 11 provided on the emission surface in the upper part of the figure.
  • the video display device 1 it is possible to further improve the light utilization efficiency and its uniform illumination characteristics, and at the same time, it can be manufactured in a small size and at low cost, including a modular S-polarized light source device. It becomes possible.
  • the polarization conversion element 21 was explained as being attached after the collimator 15, but the present invention is not limited thereto, and the same effect can be obtained by providing it in the optical path leading to the liquid crystal display panel 11. ⁇ Effects can be obtained.
  • the light guide light reflecting portion (surface) 172 has a large number of reflecting surfaces 172a and connecting surfaces 172b alternately formed in a sawtooth shape, and the illumination light flux is totally reflected on each reflecting surface 172a. Furthermore, a narrow-angle diffuser plate is provided on the light guide light emitting part (surface) 173, and the light enters the light direction conversion panel 54 that adjusts the directivity as a substantially parallel diffused light flux, and from an oblique direction. The light enters the liquid crystal display panel 11. The direction of the light emitted from the video display device 1 is controlled by a light direction conversion panel 54 provided on the top surface of the light source device 13.
  • the light emitted from the liquid crystal display panel 11 is also controlled, and the light diffusion direction of the spatially floating image obtained by the spatially floating image display system using this image display device 1 is controlled.
  • the light direction conversion panel 54 is provided between the light guide output surface 173 and the liquid crystal display panel 11, but the same effect can be obtained even if it is provided on the output surface of the liquid crystal display panel 11.
  • the light emitted from the liquid crystal display panel 11 has, for example, the "conventional characteristic (X direction)" in FIG. 20(A) and the “conventional characteristic (Y direction)” in FIG. 20(B).
  • X direction the "conventional characteristic
  • Y direction the "conventional characteristic" in FIG. 20(B)
  • the screen horizontal direction the display direction corresponding to the X-axis of the graph in FIG. 20(A)
  • the screen vertical direction the display direction corresponding to the Y-axis of the graph in FIG. 20(B) and have similar diffusion characteristics.
  • the diffusion characteristics of the emitted light flux from the liquid crystal display panel of this example are, for example, "Example 1 (X direction)" in FIG. 20(A) and “Example 1 (Y direction)” in FIG. 20(B).
  • the diffusion characteristics are as shown in the plot curve of ⁇ direction)''.
  • the viewing angle is set to 13 degrees at which the brightness is 50% of the brightness when viewed from the front (angle of 0 degrees) (brightness reduced by about half), The angle is approximately 1/5 of the diffusion characteristic (angle of 62 degrees) of a device for TV use.
  • the upper viewing angle may be suppressed (narrowed) to about 1/3 of the lower viewing angle. , optimize the reflection angle of the reflective light guide, the area of the reflective surface, etc.
  • the amount of light directed toward the user's viewing direction is significantly increased (significantly improved in terms of image brightness).
  • the brightness of such an image is 50 times or more.
  • the viewing angle is such that the brightness is 50% of the brightness of the image obtained when viewed from the front (angle of 0 degrees) (brightness reduced to approximately half). If it is set to be 5 degrees, the angle will be about 1/12 (narrow viewing angle) of the diffusion characteristic (angle of 62 degrees) of a device for general home TV use.
  • reflective type Optimize the reflection angle of the light guide and the area of the reflection surface.
  • the brightness (amount of light) of images directed toward the viewing direction (direction of the user's line of sight) is significantly improved compared to conventional LCD TVs, and the brightness of such images is more than 100 times higher. .
  • the viewing angle a narrow angle
  • the amount of light directed toward the viewing direction can be concentrated, so the efficiency of light utilization is greatly improved.
  • the light diffusion characteristics of the light source device it is possible to achieve a significant increase in brightness with the same power consumption, making it possible to achieve brightness for bright outdoor displays. It can be a video display device compatible with the system.
  • FIG. 21 shows the long side of the liquid crystal display panel and the short side of the liquid crystal display panel when the distance L from the liquid crystal display panel to the viewer and the panel size of the video display device (screen ratio 16:10) are taken as parameters.
  • the convergence angle may be set in accordance with the short side of the liquid crystal display panel (as appropriate, refer to the direction of arrow V in FIG. 20).
  • the convergence angle is set to 10 degrees.
  • image light from each corner (four corners) of the screen can be effectively projected or output toward the viewer.
  • the basic configuration is such that a light source device causes a light beam with a narrow directional characteristic to enter the liquid crystal display panel 11, and the brightness is modulated in accordance with the video signal.
  • An image displayed on a screen is reflected by a retroreflective member, and a floating image obtained in space is displayed outdoors or indoors via a transparent member 100.
  • FIG. 21 shows the convergence of the long side of the liquid crystal display panel and the short side of the liquid crystal display panel when the distance L from the liquid crystal display panel to the viewer and the panel size of the video display device (screen ratio 16:10) are taken as parameters. The angle is determined based on the positions of the left and right eyes.
  • the convergence angle in binocular vision between the left and right eyes is an important requirement. It is designed so that the image light is directed to the optimum view of the system by giving it characteristics.
  • Example 1 of light source device Next, another example of the light source device will be described with reference to FIG. 3.
  • 3A and 3B are diagrams in which the liquid crystal display panel 11 and a portion of the diffusion plate 206 are omitted in order to explain the light guide 311.
  • FIG. 3 shows a state in which the LED 14 constituting the light source is attached to the substrate 102. These LEDs 14 and substrate 102 are attached to the reflector 300 at predetermined positions.
  • the LEDs 14 are arranged in a line in a direction parallel to the side (the short side in this example) of the liquid crystal display panel 11 on the side where the reflector 300 is arranged.
  • a reflector 300 is arranged corresponding to the arrangement of the LEDs. Note that a plurality of reflectors 300 may be arranged.
  • the reflectors 300 are each formed from a plastic material.
  • the reflector 300 may be formed of a metal material or a glass material, but since a plastic material is easier to mold, a plastic material is used in this embodiment.
  • the inner surface (the right side in the figure) of the reflector 300 is a reflecting surface in the shape of a paraboloid cut along the meridian plane (hereinafter sometimes referred to as a "paraboloid"). ) 305.
  • the reflector 300 converts the diverging light emitted from the LED 14 into approximately parallel light by reflecting it on the reflecting surface 305 (paraboloid), and the converted light enters the end surface of the light guide 311.
  • a plurality of metal films such as Ti and SiO are formed on the reflective surface of the reflector 300 as reflective films to increase the reflectance and reduce the dependence on the angle of incidence as shown in FIG. And so.
  • light guide 311 is a reflective light guide.
  • the reflective surface of the reflector 300 has an asymmetric shape with respect to the optical axis of the light emitted from the LED 14. Further, the reflective surface 321 of the reflector 300 is a paraboloid as described above, and by arranging the LED at the focal point of the paraboloid, the reflected light beam is converted into substantially parallel light.
  • the LED 14 is a surface light source, the diverging light from the LED cannot be converted into completely parallel light even if it is placed at the focal point of a paraboloid, but this does not affect the performance of the light source of the present invention.
  • the LED 14 and the reflector 300 are a pair.
  • the number of LEDs mounted on the board should be no more than 10 at most, and if mass production is considered, it should be kept to about 5. Good.
  • the LED 14 and the reflector 300 are partially located close to each other, heat can be radiated to the space on the opening side of the reflector 300, so the temperature rise of the LED can be reduced. Therefore, the reflector 300 made of plastic molding can be used. As a result, according to this reflector 300, the shape precision of the reflecting surface can be improved by more than 10 times compared to a reflector made of glass material, so that the light utilization efficiency can be improved.
  • a reflective surface is provided on the bottom surface 303 of the light guide 311, and the light from the LED 14 is converted into a parallel beam by the reflector 300, and then reflected on the reflective surface, The light is emitted toward the liquid crystal display panel 11 arranged opposite to the light guide 311 .
  • the reflective surface provided on the bottom surface 303 may have a plurality of surfaces having different inclinations in the traveling direction of the parallel light beam ⁇ 2 from the reflector 300. Each of the plurality of surfaces having different inclinations may have a shape extending in a direction perpendicular to the traveling direction of the parallel light beam from the reflector 300.
  • the shape of the reflective surface provided on the bottom surface 303 may be a planar shape.
  • a diffusion plate 206 may be provided to more precisely control the diffusion characteristics of the light reflected by the reflective surface provided on the bottom surface 303 of the light guide 311 facing the liquid crystal display panel 11.
  • this diffuser plate can once refract the above-mentioned reflected light and adjust with high precision the light amount and emission direction of the light beam directed toward the liquid crystal display panel 11, so that the incident light on the liquid crystal display panel 11 can be The amount and direction of light emitted from the liquid crystal display panel 11 can also be controlled with high precision. Therefore, in a spatial video display system using a video display device using this light source, the diffusion direction and diffusion angle of the video light of the spatially floating video can be set to desired values.
  • the reflective film provided on the reflective surface should be designed to have a high reflectance and reduce the dependence of the reflectance on the angle of incidence by adding a reflective film of Ti or SiO to the aluminum reflective film, as shown in Figure 7. .
  • the aluminum reflective film mentioned above has a lower reflectance in the blue-green wavelength region of 500 nm or less than that in the green-red region, so when designing a reflective film, it is necessary to reduce the dependence of the reflectance on the incident angle and improve color reproducibility. Therefore, improving the purity of white is also an important issue.
  • the LED 14 is soldered to a metal substrate 102. Therefore, the heat generated by the LED can be radiated into the air through the substrate.
  • the reflector 300 may be in contact with the substrate 102, a space may be left open. When opening a space, the reflector 300 is placed in a state where it is adhered to the casing. By leaving the space open, the heat generated by the LED can be dissipated into the air, increasing the cooling effect. As a result, the operating temperature of the LED can be reduced, making it possible to maintain luminous efficiency and extend the lifespan.
  • Example 2 of light source device Also in the light source device described above, by using the polarization conversion element 21, the light utilization efficiency can be improved by 1.8 times.
  • the configuration of the optical system related to this light source device will be described in detail below with reference to FIGS. 13A, 13B, 13C, and 13D. Note that the illustration of the sub-reflector 308 is omitted in FIG. 13A.
  • FIG. 13A, FIG. 13B, and FIG. 13C show a state in which the LED 14 constituting the light source is attached to the substrate 102, and these are configured by a unit 312 having a plurality of blocks, including a reflector 300 and the LED 14 as a pair of blocks. .
  • the base material 320 shown in FIG. 13A(2) is the base material of the substrate 102.
  • the metallic substrate 102 has heat, so in order to insulate (insulate) the heat of the substrate 102, the base material 320 may be made of a plastic material or the like, or a metallic material to improve heat dissipation. You can also use it as
  • the reflective surface of the reflector 300 may have an asymmetric shape with respect to the optical axis of the light emitted from the LED 14. The reason for this will be explained with reference to FIG. 13A(2).
  • the reflective surface of the reflector 300 is a paraboloid, and the center of the light emitting surface of the LED, which is a surface light source, is placed at the focal point of the paraboloid.
  • the light emitted from the four corners of the light emitting surface also becomes a substantially parallel light beam, and the only difference is the emission direction. Therefore, even if the light emitting section has a large area, the amount of light incident on the polarization conversion element 21 and the conversion efficiency are hardly affected as long as the distance between the polarization conversion element disposed at the subsequent stage and the reflector 300 is short.
  • an optical system can be realized that can reduce the decrease in light conversion efficiency for the above-mentioned reasons. Furthermore, even if the mounting position of the LED 14 varies in the Z-axis direction, the converted parallel light beam only moves within the ZX plane, and the mounting accuracy of the LED, which is a surface light source, can be significantly reduced.
  • a reflector 300 having a reflecting surface formed by cutting out a part of a paraboloid in a meridian direction has been described, but an LED may be placed in a part of the entire paraboloid which is cut out as a reflecting surface.
  • the subsequent polarization conversion is performed.
  • the characteristic configuration is that the light is made incident on the end face of the element 21 and aligned to a specific polarization by the polarization conversion element 21. Due to this characteristic configuration, in this embodiment, the light utilization efficiency is 1.8 times that of the example shown in FIG. 3 described above, and a highly efficient light source can be realized.
  • the substantially parallel light obtained by reflecting the diverging light from the LED 14 on the paraboloid 321 is not all uniform. Therefore, by adjusting the angular distribution of the reflected light using the reflective surfaces 307 having a plurality of inclinations, the reflected light can be directed toward the liquid crystal display panel 11 in a direction perpendicular to the liquid crystal display panel 11 .
  • the arrangement is such that the direction of light (principal ray) entering the reflector from the LED and the direction of light entering the liquid crystal display panel are approximately parallel.
  • This arrangement is easy to arrange in terms of design, and it is preferable to arrange the heat source under the light source device because air escapes upward and the temperature rise of the LED can be reduced.
  • the light flux that cannot be captured by the reflector 300 is reflected by the sub-reflector 308 provided on the light shielding plate 309 disposed above the reflector.
  • the light is reflected by the slope of the lower sub-reflector 310 and is incident on the effective area of the polarization conversion element 21 in the subsequent stage, further improving the light utilization efficiency. That is, in this embodiment, a part of the light reflected by the reflector 300 is reflected by the sub-reflector 308, and the light reflected by the sub-reflector 308 is reflected by the sub-reflector 310 in the direction toward the light guide 306.
  • a substantially parallel light beam aligned to a specific polarization by the polarization conversion element 21 is reflected by a reflection shape provided on the surface of the reflective light guide 306 toward the liquid crystal display panel 11 disposed opposite the light guide 306. Ru.
  • the light intensity distribution of the light beam incident on the liquid crystal display panel 11 is optimally designed based on the shape and arrangement of the reflector 300 described above, the shape (cross-sectional shape) of the reflective surface of the reflective light guide, the inclination of the reflective surface, and the surface roughness. be done.
  • the shape of the reflective surface provided on the surface of the light guide 306 a plurality of reflective surfaces are arranged facing the output surface of the polarization conversion element, and the inclination and area of the reflection surface are adjusted depending on the distance from the polarization conversion element 21. , height, and pitch, the light intensity distribution of the light flux incident on the liquid crystal display panel 11 can be set to a desired value, as described above.
  • the reflective surface 307 provided on the reflective light guide By configuring the reflective surface 307 provided on the reflective light guide to have multiple inclinations on one surface, as shown in FIG. 13B (2), it is possible to adjust the reflected light with higher precision. .
  • the region used as the reflective surface may be a plurality of surfaces, a polysurface, or a curved surface.
  • the parallel light beam ⁇ 5 (R7 to R10) from the reflector 300 is reflected by a plurality of surfaces (P7 to P10) with different inclinations in the direction of travel. Head to the corresponding LCD panel section.
  • Each of the plurality of surfaces having different inclinations may have a shape extending in a direction perpendicular to the traveling direction of the parallel light beam from the reflector 300.
  • the light source light reflecting surface 307 of the light guide 306 has a configuration in which a plurality of reflecting surfaces are arranged in a direction perpendicular to the optical axis through which the light source light propagates, and the inclination angle of each reflecting surface allows the liquid crystal display panel to be The emission direction and diffusion angle of the light source light incident on the light source 11 are adjusted.
  • the reflective surface 307 of the light guide 306 has a configuration in which a plurality of reflective surfaces are arranged in a direction perpendicular to the optical axis of the light reflected by the reflective surface of the reflector 300, and the inclination of each reflective surface is The exit direction and diffusion angle of the light incident on the liquid crystal display panel 11 are adjusted by the angle.
  • the diffusion effect of the diffusion plate 206 realizes a more uniform light amount distribution.
  • the light incident on the diffuser plate on the side closer to the LED achieves a uniform light intensity distribution by changing the inclination of the reflecting surface.
  • the amount of light and the direction of emission of the light beam directed toward the liquid crystal display panel 11 can be adjusted with high precision.
  • the amount and direction of light incident on the liquid crystal display panel 11 and light emitted from the liquid crystal display panel 11 can be controlled with high precision, so that a floating image can be displayed using a video display device using this light source.
  • the direction and angle of diffusion of the image light of the spatially floating image can be set to desired values.
  • the base material of the reflective surface 307 may be made of a plastic material such as heat-resistant polycarbonate. Further, the angle of the reflecting surface 307 immediately after the light is emitted from the ⁇ /2 plate 213 changes depending on the distance between the ⁇ /2 plate and the reflecting surface.
  • the LED 14 and the reflector 300 are partially located close to each other, heat can be radiated to the space on the opening side of the reflector 300, thereby reducing the temperature rise of the LED.
  • the substrate 102 and the reflector 300 may be arranged upside down as shown in FIGS. 13A, 13B, and 13C.
  • the substrate 102 if the substrate 102 is placed on top, the substrate 102 will be close to the liquid crystal display panel 11, which may make layout difficult. Therefore, as shown in the figure, if the substrate 102 is placed below the reflector 300 (on the side far from the liquid crystal display panel 11), the internal structure of the device will be simpler.
  • a light shielding plate 410 may be provided on the light incidence surface of the polarization conversion element 21 to prevent unnecessary light from entering the optical system in the subsequent stage. With such a configuration, a light source device that suppresses temperature rise can be realized.
  • the polarizing plate provided on the light incident surface of the liquid crystal display panel 11 reduces the temperature rise by absorbing the uniformly polarized light beam of the present invention, but when it is reflected by the reflective light guide, the polarization direction rotates and some The light is absorbed by the polarizing plate on the incident side.
  • the temperature of the liquid crystal display panel 11 also rises due to absorption by the liquid crystal itself and temperature rise due to light incident on the electrode pattern, but if there is sufficient space between the reflective surface of the reflective light guide 306 and the liquid crystal display panel 11. Yes, natural cooling is possible.
  • FIG. 13D is a modification of the light source device in FIGS. 13B(1) and 13C.
  • FIG. 13D(1) shows a modified example of a part of the light source device of FIG. 13B(1).
  • the other configurations are the same as those of the light source device described above in FIG. 13B(1), so illustration and repeated description will be omitted.
  • the height of the recess 319 of the sub-reflector 310 is such that the principal ray of fluorescence output from the phosphor 114 in a horizontal direction (X-axis direction) (see a straight line extending in a direction parallel to the axis) is adjusted to be at a position lower than the phosphor 114 so that it passes through the recess 319 of the sub-reflector 310. Furthermore, in the Z-axis direction with respect to the position of the phosphor 114, so that the principal ray of fluorescence outputted laterally from the phosphor 114 enters the effective area of the polarization conversion element 21 without being blocked by the light shielding plate 410. The height of the light shielding plate 410 is adjusted to be low.
  • the reflective surface of the uneven convex portion on the top of the sub-reflector 310 reflects the light reflected by the sub-reflector 308 in order to guide the light reflected by the sub-reflector 308 to the light guide 306. Therefore, the height of the convex portion 318 of the sub-reflector 310 is adjusted so that the light reflected by the sub-reflector 308 is reflected and enters the effective area of the polarization conversion element 21 in the subsequent stage, thereby further improving the light utilization efficiency. can be improved.
  • the sub-reflector 310 is arranged to extend in one direction, and has an uneven shape. Further, on the top of the sub-reflector 310, irregularities having one or more recesses 319 and one or more projections 318 are periodically arranged in one direction. By forming such an uneven shape, it is possible to configure such that the chief ray of fluorescence outputted laterally from the phosphor 114 enters the effective area of the polarization conversion element 21.
  • the uneven shape of the sub-reflector 310 is arranged periodically at a pitch such that the recesses 319 are located at the positions where the LEDs 14 are located. That is, each of the phosphors 114 is arranged periodically along one direction corresponding to the pitch of the arrangement of the concave and convex portions of the sub-reflector 310. In addition, when the phosphor 114 is included in the LED 14, the phosphor 114 may be expressed as a light emitting part of a light source.
  • FIG. 13D(2) illustrates a modified example of a part of the light source device of FIG. 13C.
  • the other configurations are the same as those of the light source device in FIG. 13C, so illustration and repeated description will be omitted.
  • the sub-reflector 310 may not be provided, but as in FIG. 13D (1), the principal ray of fluorescence output sideways from the phosphor 114 is not blocked by the light shield 410.
  • the height of the light shielding plate 410 is adjusted to be lower in the Z-axis direction with respect to the position of the phosphor 114 so that the light enters the effective area of the polarization conversion element 21.
  • a side wall 400 may be provided to prevent stray light from entering the light source, to prevent stray light from occurring outside the light source device, and to prevent stray light from entering from outside the light source device.
  • the side wall 400 is arranged so as to sandwich the space between the light guide 306 and the diffusion plate 206.
  • the light exit surface of the polarization conversion element 21 that emits the light polarization-converted by the polarization conversion element 21 faces the space surrounded by the side wall 400, the light guide 306, the diffuser plate 206, and the polarization conversion element 21. Also, of the inner surface of the side wall 400, a portion that covers from the side the space where light is output from the output surface of the polarization conversion element 21 (the space on the right side from the output surface of the polarization conversion element 21 in FIG. 13B(1)). A reflective surface having a reflective film or the like is used as the surface. That is, the surface of the side wall 400 facing the space includes a reflective region having a reflective film.
  • the surface that covers the polarization conversion element 21 from the side is a surface with low light reflectance (such as a black surface without a reflective film). This is because when reflected light occurs on the side surface of the polarization conversion element 21, light with an unexpected polarization state is generated, causing stray light.
  • the cooling effect may be improved by opening a hole in a part of the side wall 400 for air to pass through.
  • the light source devices in FIGS. 13A, 13B, 13C, and 13D have been described on the assumption that the polarization conversion element 21 is used. However, the polarization conversion element 21 may be omitted from these light source devices. In this case, the light source device can be provided at a lower cost.
  • Example 3 of light source device the configuration of an optical system related to a light source device using a reflective light guide 304 based on the light source device shown in Example 1 of the light source device is shown in FIGS. This will be explained in detail with reference to 14B.
  • FIG. 14A shows a state in which the LED 14 constituting the light source is mounted on the substrate 102, and the collimator 18 and the LED 14 form a pair of blocks, and the unit 328 has a plurality of blocks. Since the collimator 18 of this embodiment is close to the LED 14, a glass material is used in consideration of heat resistance. The shape of the collimator 18 is similar to the shape described for the collimator 15 in FIG. Furthermore, by providing a light shielding plate 317 before entering the polarization conversion element 21, unnecessary light is prevented or suppressed from entering the optical system at the subsequent stage, and temperature rise due to the unnecessary light is reduced. .
  • FIG. 13A The other configurations and effects of the light source shown in FIG. 13A are the same as those in FIGS. 13A, 13B, 13C, and 13D, so repeated explanations will be omitted.
  • the light source device in FIG. 13A may be provided with side walls in the same manner as described in FIGS. 13A, 13B, and 13C. The configuration and effects of the side walls have already been explained, so repeated explanations will be omitted.
  • FIG. 14B is a cross-sectional view of FIG. 14A(2).
  • the configuration of the light source shown in FIG. 14B is common to a part of the structure of the light source in FIG. 17, and has already been explained in FIG. 17, so repeated explanation will be omitted.
  • the light source device of FIG. 4 is configured with a unit including a plurality of blocks, each of which includes the collimator 18 and the LED 14 used in the light source device shown in FIGS. 14A and 14B as a pair of blocks.
  • the configuration of an optical system related to a light source device using LEDs and reflective light guides 504 arranged at both ends of the back surface of the liquid crystal display panel 11 will be explained in detail with reference to FIGS. 4(a), (b), and (c). do.
  • FIG. 4 shows a state in which the LEDs 14 constituting the light source are mounted on a substrate 505, and these are constituted by a unit 503 having a plurality of blocks in which the collimator 18 and the LEDs 14 form a pair of blocks.
  • the units 503 are arranged at both ends of the back surface of the liquid crystal display panel 11 (in this embodiment, three units are arranged side by side in the short side direction).
  • the light output from the unit 503 is reflected by the reflective light guide 504 and is incident on the liquid crystal display panel 11 (not shown) placed opposite to it.
  • the reflective light guide 504 is divided into two blocks corresponding to the units arranged at each end, and arranged so that the central part is the highest. Since the collimator 18 is close to the LED 14, a glass material is used in consideration of heat resistance to the heat emitted from the LED 14. The shape of the collimator 18 is the shape described for the collimator 18 in FIG. 14A(3).
  • the light from the LED 14 enters the polarization conversion element 501 via the collimator 18.
  • the configuration is such that the shape of the optical element 81 adjusts the distribution of light incident on the reflective light guide 504 at the subsequent stage. That is, the light intensity distribution of the luminous flux incident on the liquid crystal display panel 11 is determined by the shape of the collimator 18, the arrangement, the shape of the optical element 81, the diffusion characteristics, and the shape (cross-sectional shape) of the reflective surface of the reflective light guide.
  • Optimal design is achieved by adjusting the inclination of the reflective surface and the surface roughness of the reflective surface.
  • the shape of the reflective surface provided on the surface of the reflective light guide 504 is as shown in FIG. Optimize the tilt, area, height, and pitch of the reflective surface according to the distance.
  • the light intensity distribution of the light beam incident on the liquid crystal display panel 11 can be set to a desired value (optimal can be converted into Therefore, the amount of light and the direction of emission of the light beam toward the liquid crystal display panel 11 can be adjusted with high precision.
  • the amount and direction of light incident on the liquid crystal display panel 11 and light emitted from the liquid crystal display panel 11 can be controlled with high precision, so that a floating image can be displayed using a video display device using this light source.
  • the direction and angle of diffusion of the image light of the spatially floating image can be set to desired values (see the four solid line arrows incident on the light guide in FIG. 13B(2)).
  • the reflective surface provided on the reflective light guide has a configuration in which one surface (the area where light is reflected) has a shape with multiple inclinations ( In the example of FIG. 4, by dividing the XY plane into 14 parts and configuring them with different inclined surfaces, it is possible to adjust the reflected light with higher precision.
  • a light shielding wall 507 is provided to prevent light from leaking in a direction other than the desired direction (direction toward the liquid crystal display panel 11). can be prevented from occurring.
  • the units 503 placed on the left and right sides of the reflective light guide 504 in FIG. 4 may be replaced with the light source device in FIG. 13A. That is, a plurality of light source devices (substrate 102, reflector 300, LED 14, etc.) shown in FIG. 13A are prepared, and the plurality of light source devices are connected to each other as shown in FIGS. It is also possible to have a configuration in which they are placed at opposing positions.
  • FIG. 18(B) shows a light source device configured by arranging six units 503 shown in FIG. 18(A) in the upper part and six units in the lower part.
  • the light source device shown in FIG. 18B has a configuration in which a unit 503 in which five LEDs are arranged side by side is arranged as described above, and a desired brightness is obtained by controlling the current with a single power supply. Therefore, as a light source device that illuminates the liquid crystal panel, the light source brightness can be controlled for each area illuminated by each unit 503.
  • the configuration shown in FIG. 18 includes a reflective surface 222 and a reflective surface 502 different from the reflective surface 222.
  • the reflective surface 222 has a horizontal lattice-like shape or a band shape with a predetermined width.
  • the reflective surface 502 has a shape like a vertical and horizontal lattice.
  • the amount and direction of light incident on the liquid crystal display panel 11 and the light emitted from the liquid crystal display panel 11 can be controlled with high precision.
  • the diffusion direction and diffusion angle of image light of a spatially floating video can be set to desired values.
  • FIG. 15 is a cross-sectional view showing an example of the shape of the diffusion plate 206.
  • the diverging light output from the LED is converted into substantially parallel light by the reflector 300 or the collimator 18, converted into a specific polarized light by the polarization conversion element 21, and then reflected by the light guide. Then, the light beam reflected by the light guide passes through the flat part of the incident surface of the diffuser plate 206 and enters the liquid crystal display panel 11 (two lines indicating "reflected light from the light guide" in FIG. 15). (see solid arrow).
  • a diverging luminous flux is totally reflected on the slope of a protrusion having an inclined surface provided on the incident surface of the diffuser plate 206 and enters the liquid crystal display panel 11 .
  • the angle of the slope of the projection is changed based on the distance from the polarization conversion element 21.
  • a lenticular lens is provided between the light source device 13 and the liquid crystal display panel 11, or on the surface of the liquid crystal display panel 11, and the shape of the lens is optimized.
  • One example is to become That is, by optimizing the shape of the lenticular lens, the emission characteristics of the image light (hereinafter also referred to as "image light flux") emitted from the liquid crystal display panel 11 in one direction can be adjusted.
  • the microlens array may be arranged in a matrix on the surface of the liquid crystal display panel 11 (or between the light source device 13 and the liquid crystal display panel 11), and the manner of the arrangement may be adjusted. That is, by adjusting the arrangement of the microlens array, the emission characteristics of the image light flux emitted from the image display device 1 in the X-axis and Y-axis directions can be adjusted, and as a result, desired diffusion characteristics can be obtained. It is possible to obtain a video display device having the following.
  • a combination of two lenticular lenses may be arranged at a position through which the image light emitted from the image display device 1 passes, or a microlens array may be arranged in a matrix to adjust the diffusion characteristics.
  • a sheet may also be provided.
  • the image light has a narrow diffusion angle (high straightness) and has only a specific polarization component, like image light from a surface-emitting laser image source, and the image display device according to the prior art It is possible to suppress the ghost image that would occur in the retroreflective member when using the retroreflection member, and to make adjustments so that the spatially floating image due to retroreflection can be efficiently delivered to the viewer's eyes.
  • the above-described light source device allows the X-axis It is possible to provide a directional characteristic with a significantly narrow angle in both the direction and the Y-axis direction. In this embodiment, by providing such a narrow-angle directivity characteristic, it is possible to realize an image display device that emits a nearly parallel image light beam in a specific direction and emits light of a specific polarization. .
  • FIG. 19 shows an example of the characteristics of the lenticular lens employed in this example.
  • This example particularly shows the characteristics in the X direction (vertical direction) with respect to the Z axis, and the characteristic O is that the peak of the light emission direction is at an angle of around 30 degrees upward from the vertical direction (0 degrees). , and exhibits vertically symmetrical brightness characteristics.
  • the plot curves of characteristic A and characteristic B shown in the graph of FIG. 19 further show an example of a characteristic in which the brightness (relative brightness) is increased by focusing the image light above the peak brightness around 30 degrees. There is.
  • the optical system including the above-mentioned lenticular lens when the image light flux from the image display device 1 is made to enter the retroreflective member, the output angle and viewing angle of the image light aligned at an included angle by the light source device 13 are adjusted. can be adjusted, greatly increasing the degree of freedom in installing retroreflective sheets. As a result, the degree of freedom regarding the image formation position of the spatially floating image that is reflected or transmitted through the window glass and formed at a desired position can be greatly improved. As a result, it becomes possible to efficiently reach the eyes of a viewer outdoors or indoors as light with a narrow diffusion angle (high straightness) and only a specific polarization component.
  • the viewer can accurately recognize the image light and obtain information.
  • the output of the video display device 1 it is possible to realize a display system with low power consumption.
  • the present invention is not limited to the embodiment (specific example) described above, and includes various modifications.
  • the entire system is explained in detail in order to explain the present invention in an easy-to-understand manner, and the system is not necessarily limited to having all the configurations described.
  • the light source device described above is not limited to a floating image display device, but can also be applied to display devices such as a HUD, a tablet, a digital signage, etc.
  • the user can, for example, operate the video without feeling anxious about contact transmission of an infectious disease. enable. If the technology according to this embodiment is used in a system used by an unspecified number of users, it will be possible to reduce the risk of contact transmission of infectious diseases and provide a contactless user interface that can be used without anxiety. . According to the present invention, which provides such a technology, it contributes to "3 health and welfare for all" of the Sustainable Development Goals (SDGs) advocated by the United Nations.
  • SDGs Sustainable Development Goals
  • the technology according to the embodiment described above makes it possible to form a spatially floating image using highly directional (straight-progressing) image light.
  • the technology according to the fifth embodiment even when displaying images that require high security such as at bank ATMs or ticket vending machines at stations, or when displaying highly confidential images that should be kept secret from the person directly facing the user, the directional By displaying a high image light, it is possible to provide a non-contact user interface in which there is little risk of a person other than the user looking into the floating image.
  • the present invention contributes to the Sustainable Development Goals (SDGs: Sustainable Development Goals 11) advocated by the United Nations.
  • SYMBOLS 1 Image display device, 2... First retroreflective member, 5... Second retroreflective member, 3... Spatial image (spatial floating image), 100... Transmissive plate, 13... Light source device, 54... Light direction conversion Panel, 105... Linear Fresnel sheet, 101... Absorption type polarizing sheet (absorption type polarizing plate), 200... Flat display, 201... Housing, 203... Sensing system, 226... Sensing area, 102... Substrate, 11, 335... Liquid crystal Display panel, 206... Diffusion plate, 21... Polarization conversion element, 300... Reflector, 213... ⁇ /2 plate, 306... Reflective light guide, 307... Reflective surface, 308, 310...

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Optical Elements Other Than Lenses (AREA)

Abstract

La présente invention affiche de manière appropriée une vidéo à l'extérieur d'un espace. La présente invention contribue aux objectifs de développement durables de « 3. Bonne santé et bien-être, " 9. L'industrie, l'innovation et l'infrastructure," et "11. Les villes et les communautés durables." Ce système d'affichage vidéo flottante spatiale comprend : un écran d'affichage qui affiche une vidéo ; un dispositif de source de lumière pour l'écran d'affichage ; et un élément de rétroréflexion qui réfléchit une lumière vidéo provenant de l'écran d'affichage, et amène une vidéo flottante spatiale d'une image réelle à être affichée dans l'air intermédiaire à l'aide de la lumière réfléchie, l'élément de rétroréflexion comprenant une plaque de différence de phase, et la plaque de différence de phase présentant une dispersion de longueur d'onde inverse et étant positionnée sur le côté de surface d'incidence de lumière vidéo de l'élément rétroréfléchissant.
PCT/JP2023/021189 2022-07-01 2023-06-07 Système d'affichage vidéo flottante spatiale WO2024004557A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2022107164 2022-07-01
JP2022-107164 2022-07-01

Publications (1)

Publication Number Publication Date
WO2024004557A1 true WO2024004557A1 (fr) 2024-01-04

Family

ID=89382801

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2023/021189 WO2024004557A1 (fr) 2022-07-01 2023-06-07 Système d'affichage vidéo flottante spatiale

Country Status (1)

Country Link
WO (1) WO2024004557A1 (fr)

Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2004021129A (ja) * 2002-06-20 2004-01-22 Sekisui Jushi Co Ltd 再帰反射体
JP2009534225A (ja) * 2006-04-18 2009-09-24 スリーエム イノベイティブ プロパティズ カンパニー オレフィン系封止フィルムを含む再帰反射物品
JP2011128512A (ja) * 2009-12-21 2011-06-30 Sony Corp 光学体およびその製造方法
WO2011136214A1 (fr) * 2010-04-28 2011-11-03 シャープ株式会社 Système optique
WO2016088683A1 (fr) * 2014-12-01 2016-06-09 合同会社Ｓｎパートナーズ Dispositif d'affichage d'image à flottement libre
JP2018092000A (ja) * 2016-12-02 2018-06-14 日本ゼオン株式会社 空間表示装置
US20180188548A1 (en) * 2017-01-05 2018-07-05 Looking Glass Factory, Inc. Advanced retroreflecting aerial displays
WO2018151220A1 (fr) * 2017-02-15 2018-08-23 富士フイルム株式会社 Dispositif optique
JP2021067875A (ja) * 2019-10-25 2021-04-30 昭和電工株式会社 光制御パネルの製造方法及び光学結像装置の製造方法
WO2022030538A1 (fr) * 2020-08-06 2022-02-10 マクセル株式会社 Système d'affichage d'informations d'image flottante spatiale et dispositif de source de lumière utilisé pour celui-ci
JP2022050365A (ja) * 2020-09-17 2022-03-30 神田工業株式会社 展示装置及び展示方法

Patent Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2004021129A (ja) * 2002-06-20 2004-01-22 Sekisui Jushi Co Ltd 再帰反射体
JP2009534225A (ja) * 2006-04-18 2009-09-24 スリーエム イノベイティブ プロパティズ カンパニー オレフィン系封止フィルムを含む再帰反射物品
JP2011128512A (ja) * 2009-12-21 2011-06-30 Sony Corp 光学体およびその製造方法
WO2011136214A1 (fr) * 2010-04-28 2011-11-03 シャープ株式会社 Système optique
WO2016088683A1 (fr) * 2014-12-01 2016-06-09 合同会社Ｓｎパートナーズ Dispositif d'affichage d'image à flottement libre
JP2018092000A (ja) * 2016-12-02 2018-06-14 日本ゼオン株式会社 空間表示装置
US20180188548A1 (en) * 2017-01-05 2018-07-05 Looking Glass Factory, Inc. Advanced retroreflecting aerial displays
WO2018151220A1 (fr) * 2017-02-15 2018-08-23 富士フイルム株式会社 Dispositif optique
JP2021067875A (ja) * 2019-10-25 2021-04-30 昭和電工株式会社 光制御パネルの製造方法及び光学結像装置の製造方法
WO2022030538A1 (fr) * 2020-08-06 2022-02-10 マクセル株式会社 Système d'affichage d'informations d'image flottante spatiale et dispositif de source de lumière utilisé pour celui-ci
JP2022050365A (ja) * 2020-09-17 2022-03-30 神田工業株式会社 展示装置及び展示方法

Similar Documents

Publication Publication Date Title
US11016341B2 (en) Directional illumination apparatus and privacy display
JP6403216B2 (ja) 指向性バックライトにおけるクロストークの抑制
US20140240828A1 (en) Directional Backlight
WO2010061699A1 (fr) Système mince de rétroéclairage et dispositif d'affichage à cristaux liquides l'utilisant
WO2022030538A1 (fr) Système d'affichage d'informations d'image flottante spatiale et dispositif de source de lumière utilisé pour celui-ci
WO2023112617A1 (fr) Système d'affichage d'image flottante aérienne
WO2024004557A1 (fr) Système d'affichage vidéo flottante spatiale
WO2022118752A1 (fr) Dispositif d'affichage d'image flottant dans l'espace et dispositif source de lumière
WO2022080117A1 (fr) Appareil d'affichage d'image vidéo à espace flottant et dispositif de source de lumière
US20110037923A1 (en) Light condensing film, backlight module and liquid crystal display
JP7367148B2 (ja) 空間浮遊映像表示装置
JP7370433B2 (ja) 空間浮遊映像情報表示システムに用いられる光源装置
WO2024024275A1 (fr) Système d'affichage d'image flottante spatiale portable
WO2023199685A1 (fr) Système d'affichage de vidéo flottante spatiale et système de traitement de vidéo flottante spatiale
WO2023228530A1 (fr) Système d'affichage d'informations d'image flottante spatiale
WO2023136077A1 (fr) Système d'affichage d'image flottante spatiale, dispositif de source de lumière utilisé à cet effet, élément rétroréfléchissant et système optique
JP2006179319A (ja) 光源装置および液晶表示装置
WO2023037813A1 (fr) Système d'affichage d'informations vidéo en espace flottant et dispositif de détection stéréo utilisé dans celui-ci
JP2023115747A (ja) 空間浮遊映像情報表示システムおよびそれに用いられる光源装置
JP2023102461A (ja) 空間浮遊映像情報表示システムおよびそれに用いられる光学系
CN114488538B (zh) Ar光机和头戴显示设备
JP2023117741A (ja) 空間浮遊映像情報表示システムおよびそれに用いられる光学系
JP2023113009A (ja) 空間浮遊映像情報表示システム及びそれに用いる再帰反射部材
JP2023122179A (ja) 空間浮遊映像表示システム
JP2023087963A (ja) 空間浮遊映像情報表示システムおよびそれに用いられる光学系

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 23831007

Country of ref document: EP

Kind code of ref document: A1