WO2024004557A1 - Spatial floating video display system - Google Patents

Spatial floating video display system Download PDF

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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
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WIPO (PCT)
Prior art keywords
light
image
display system
floating
light source
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PCT/JP2023/021189
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French (fr)
Japanese (ja)
Inventor
浩二 平田
智貴 山本
寿紀 杉山
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マクセル株式会社
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Publication of WO2024004557A1 publication Critical patent/WO2024004557A1/en

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    • 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...

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Abstract

The present invention appropriately displays a video to outside of a space. The present invention contributes to the Sustainable Development Goals of "3. Good health and well-being," "9. Industry, innovation and infrastructure," and "11. Sustainable cities and communities." This spatial floating video display system comprises: a display panel that displays a video; a light source device for the display panel; and a retroreflection member that reflects a video light from the display panel, and causes a spatial floating video of a real image to be displayed in midair using the reflected light, wherein the retroreflection member includes a phase difference plate, and the phase difference plate demonstrates reverse wavelength dispersion and is positioned on the video light incident surface side of the retroreflective member.

Description

空間浮遊映像表示システムSpace floating video display system
　本発明は、空間浮遊映像表示システムに関する。 The present invention relates to a spatial floating video display system.
　空間浮遊映像表示システムとして、直接外部に向かって映像を表示する映像表示装置と空間画面として表示される表示法は既に知られている。また、空間像を表示する再帰反射部材については、例えば、特許文献１に開示されている。更に、例えば、特許文献２に開示されている。 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.
特開２０１７－０６７９３３号公報JP2017-067933A 特開２０１９－１３３１０９号公報Japanese Patent Application Publication No. 2019-133109
　空間浮遊映像表示システムとして、直接外部に向かって映像を表示する映像表示装置と空間画面として表示される表示法は既に知られている。しかしながら、上述した従来技術の空間浮遊映像装置において空間浮遊映像の輝度、色度について光源を含めた設計の最適化については考慮されていない。 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. However, in the above-mentioned conventional space floating image device, no consideration is given to optimization of the design including the light source for the brightness and chromaticity of the space floating image.
　本発明の目的は、空間浮遊映像表示システムまたは空間浮遊映像表示装置において、視認性（見た目の解像度やコントラスト）が高く、色再現性の高い空間浮遊映像表示が可能な技術を提供することにある。 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. .
　上記課題を解決するために、例えば特許請求の範囲に記載の構成を採用する。本願は上記課題を解決する手段を複数含んでいるが、その一例としての空間浮遊映像表示装置を以下に挙げる。本願の一例としての空間浮遊映像表示システムは、映像を表示する表示パネルと、表示パネルのための光源装置と、表示パネルからの映像光を反射させ、反射した光により空中に実像の空間浮遊映像を表示せしめる再帰反射部材と、を備え、再帰反射部材は位相差板を含み、位相差板は逆波長分散を有し、再帰反射部材の映像光入射面側に配置される。 In order to solve the above problem, for example, the configuration described in the claims is adopted. The present application includes a plurality of means for solving the above-mentioned problems, and a spatial floating video display device as an example thereof will be listed below. 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.
　本発明によれば、空間浮遊映像表示システムにおいて、従来課題として認識されていた視認性（見た目の解像度やコントラスト）の他に、表示する空間浮遊映像の色再現性を高めた高品質な映像表示が可能な空間浮遊映像表示装置を実現することができる。
上記以外の課題、構成および効果は、以下の実施形態の説明により明らかにされる。 According to the present invention, in addition to visibility (visual resolution and contrast), which has been recognized as an issue in the past, 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.
本発明の一実施例に係る再帰反射部材の構成と空間浮遊像の発生位置を示す図である。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. 本発明の一実施例に係る再帰反射部材の構成と空間浮遊像の発生位置を示す図である。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. 本発明の一実施例に係る再帰反射部材の構成と空間浮遊像の発生位置を示す図である。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. 本発明の一実施例に係る再帰反射部材を構成する光学部材の特性を説明するための説明図である。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. 本発明の一実施例に係る光源装置の具体的な構成の例を示す構造図である。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. 光源装置の具体的な構成の例を示す斜視、上面および断面図である。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. 一般的な白色ＬＥＤ光源の発光スペクトルを示す特性図である。It is a characteristic diagram showing the emission spectrum of a general white LED light source. 本願発明の一実施例のリフレクタの反射特性を示す特性図である。FIG. 3 is a characteristic diagram showing the reflection characteristics of a reflector according to an embodiment of the present invention. 本願発明の一実施例の導光体の反射特性を示す特性図である。FIG. 3 is a characteristic diagram showing the reflection characteristics of a light guide according to an embodiment of the present invention. 一般的な偏光板の分光透過率を示す特性図である。It is a characteristic diagram showing the spectral transmittance of a general polarizing plate. 液晶パネルに使用する偏光板の分光透過率を示す特性図である。FIG. 2 is a characteristic diagram showing the spectral transmittance of a polarizing plate used in a liquid crystal panel. 偏光板の構成を示す断面図である。FIG. 3 is a cross-sectional view showing the configuration of a polarizing plate. 本発明の一実施例に係る空間浮遊映像表示装置の白色表示の際の色度を示す色度図である。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. 本発明の一実施例に係る空間浮遊映像表示装置の白色表示の際の色度を示す色度図にマクアダムの色弁別楕円を重ねた色度図である。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. 別方式の光源装置の具体的な構成の別の例を示す構造図である。FIG. 7 is a structural diagram showing another example of a specific configuration of a light source device of another type. 別方式の光源装置の具体的な構成の別の例の一部を抜粋した図である。FIG. 7 is a diagram illustrating a part of another example of a specific configuration of a light source device of another type. 別方式の光源装置の具体的な構成の別の例の一部を抜粋した図である。FIG. 7 is a diagram illustrating a part of another example of a specific configuration of a light source device of another type. 別方式の光源装置の具体的な構成の別の例の一部を抜粋した図である。FIG. 7 is a diagram illustrating a part of another example of a specific configuration of a light source device of another type. 別方式の光源装置の具体的な構成の別の例を示す構造図である。FIG. 7 is a structural diagram showing another example of a specific configuration of a light source device of another type. 別方式の光源装置の具体的な構成の別の例を示す図である。FIG. 7 is a diagram illustrating another example of a specific configuration of a light source device of another type. 光源装置の具体的な構成の別の例の導光体拡散部の表面形状を示す拡大図である。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. 光源装置の具体的な構成の例を示す断面図である。FIG. 2 is a cross-sectional view showing an example of a specific configuration of a light source device. 光源装置の具体的な構成の例を示す構造図である。FIG. 2 is a structural diagram showing an example of a specific configuration of a light source device. 光源装置の具体的な構成の例を示す斜視および上面図である。FIG. 2 is a perspective view and a top view showing an example of a specific configuration of a light source device. 映像表示装置の拡散特性を説明するための説明図である。FIG. 3 is an explanatory diagram for explaining the diffusion characteristics of the video display device. 映像表示装置の拡散特性を説明するための説明図である。FIG. 3 is an explanatory diagram for explaining the diffusion characteristics of the video display device. 映像表示装置の光源拡散特性を説明するための説明図である。FIG. 3 is an explanatory diagram for explaining light source diffusion characteristics of a video display device. 液晶パネルの視覚特性を測定する座標系を示す図である。FIG. 3 is a diagram showing a coordinate system for measuring visual characteristics of a liquid crystal panel. 一般的な液晶パネルの輝度角度特性（長手方向）を示す図である。FIG. 2 is a diagram showing brightness angle characteristics (longitudinal direction) of a general liquid crystal panel. 一般的な液晶パネルの輝度角度特性（短手方向）を示す図である。FIG. 3 is a diagram showing the brightness angle characteristics (in the lateral direction) of a general liquid crystal panel. 一般的な液晶パネルのコントラストの角度特性（長手方向）を示す図である。FIG. 2 is a diagram showing contrast angle characteristics (longitudinal direction) of a general liquid crystal panel. 一般的な液晶パネルのコントラストの角度特性（短手方向）を示す図である。FIG. 3 is a diagram showing contrast angle characteristics (lateral direction) of a general liquid crystal panel.
　以下、本発明の実施の形態を、図面を参照して詳細に説明する。なお、本発明は、以下に説明する実施形態（以下、「本開示」ともいう）の内容に限定されるものではない。本発明は、発明の精神ないし特許請求の範囲に記載された技術的思想の範囲またはその均等範囲物にも及ぶ。また、以下に説明する実施形態（実施例）の構成は、あくまで例示に過ぎないのであって、本明細書に開示される技術的思想の範囲において、当業者による様々な変更および修正が可能である。 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the content of the embodiments (hereinafter also referred to as "this disclosure") described below. The present invention extends to the spirit of the invention and the scope of the technical ideas described in the claims, or to equivalents thereof. Further, the configuration of the embodiment (example) described below is merely an example, and various changes and modifications can be made by those skilled in the art within the scope of the technical idea disclosed in this specification. be.
　また、本発明を説明するための図面において、同一または類似の機能を有するものには、同一の符号を付与し、適宜、異なる名称を使用する一方で、機能等の繰り返しの説明を省略する場合がある。なお、以下の実施形態の説明において、空間に浮遊する映像を「空間浮遊映像」という用語で表現している。この用語の代わりに、「空中像」、「空間像」、「空中浮遊映像」、「表示映像の空間浮遊光学像」、「表示映像の空中浮遊光学像」などと表現してもかまわない。実施形態の説明で主として用いる「空間浮遊映像」の用語は、これらの用語の代表例として用いている。 In addition, in the drawings for explaining the present invention, parts having the same or similar functions are given the same reference numerals, different names are used as appropriate, and repeated explanations of functions, etc. are omitted. There is. In the following description of the embodiment, an image floating in space is expressed using the term "space floating image." Instead of this terminology, expressions such as "aerial image", "aerial image", "aerial floating image", "aerial floating optical image of a display image", "aerial floating optical image of a display image", etc. may be used. The term "space floating image" mainly used in the description of the embodiments is used as a representative example of these terms.
　本開示は、例えば、大面積な映像発光源からの映像光による映像を、ショーウィンドのガラス等の空間を仕切る透明な部材を介して透過して、店舗（空間）の内部または外部に空間浮遊映像として表示することが可能な表示システムに関する。また、本開示は、かかる表示システムを複数用いて構成される大規模なデジタルサイネージシステムに関する。 The present disclosure, for example, 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.
　以下の実施形態によれば、例えば、ショーウィンドのガラス面や光透過性の板材上に高解像度な映像を空間浮遊した状態で表示可能となる。この時、出射する映像光の発散角を小さく、すなわち鋭角とし、更に特定の偏波に揃えることで、再帰反射部材に対して正規の反射光だけを効率良く反射させることができる。 According to 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. At this time, by making 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.
　また、光源装置と映像表示用の液晶表示パネルおよび再帰反射部材の透過率または反射率を所定の範囲に設定するとともに光源装置から液晶表示パネルに入射する光束の発散角を制御し、液晶表示パネルから出射し再帰反射部材で反射する映像光束の波長を調整することでシステム全体の色再現性を向上する。このため、光の利用効率が高く、従来の再帰反射方式で新たな課題となった空間浮遊像の色再現性を向上させ鮮明な空間浮遊映像を得ることができる。 In addition, 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.
　また、本開示の光源を含む装置と光学系により、消費電力を大幅に低減することが可能な、新規で利用性に優れた空間浮遊映像表示システムを提供することができる。 Further, by using 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.
　一方、従来の空間浮遊映像表示システムでは、高解像度なカラー表示映像源として有機ＥＬパネルや液晶表示パネル（液晶パネルまたは表示パネル）を、再帰反射部材と組み合わせる。特定偏波の映像光を使用できる液晶パネルを映像表示素子として用いた従来技術による空間浮遊映像表示装置において使用される第一の再帰反射部材２の表面には図１Ｂに示した多面体からなる反射面が形成されている。 On the other hand, in conventional spatial floating image display systems, 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.
　このため、広角で拡散する映像光では図１Ａに示すように正規に反射する反射光による浮遊像２２０（Ｒ１）の他にゴースト像が複数発生する。図１Ｂに示す反射部材２‘に用いられる形状は６面体であるために、斜めから入射する映像光によって、符号ｇ１、ｇ２に示すようなゴースト像を含む６個のゴースト像が発生し、空間浮遊映像の画質を損ねていた。また、観視者以外にもゴースト像である同一空間浮遊映像を観視されてしまい、セキュリティ上の観点からも、大きな課題があった。 Therefore, in the case of wide-angle and diffused image light, multiple ghost images are generated in addition to the floating image 220 (R1) caused by normally reflected reflected light, as shown in FIG. 1A. Since the shape used for the reflecting member 2' shown in FIG. 1B is a hexahedron, six ghost images including ghost images as shown by symbols g1 and g2 are generated by the image light incident obliquely, and the space The image quality of the floating video was impaired. Additionally, the ghost images floating in the same space could be viewed by people other than the viewers, which posed a major problem from a security perspective.
　＜色再現性の高い反射型再帰反射部材＞
　再帰反射部材２の断面構造を図１Ｃに示す。再帰反射部材２は、反射層２ａと透過性基材２ｂと反射面２ｃと逆波長分散特性を有する位相差板であるλ／４板２ｄとで構成される。再帰反射部材は、再帰反射部材の映像光入射面側から順に逆波長分散特性を有する位相差板２d、透過性基材２ｂ、反射層２a、透過性基材２b、反射面２cとなるように構成される。位相差板はポリカーボネート材料を用いてもよい。反射層２ａの屈折率に近い部材で充填し透過性基材２ｂで挟み込むことで必要な機械的強度を得る構成としている。映像光入射面にはλ／４板２ｄを配置し映像光が反射面２ｃで反射し再帰反射部材で２度反射することで再帰反射光が形成される。すなわち、再帰反射部材２に入射した光は、逆波長分散特性を有する位相差板２ｄに入射し、透過性基材２ｂ、反射層２aを透過し、反射面２ｃで反射され、透過性基材２ｂ、反射層２aを透過し、再度位相差板２ｄに入射する。このとき、反射層２aに入射した光のほとんどは透過するが、一部反射する光もある。よって、例えば再帰反射部材２に入射した光がS偏波の光の場合、再帰反射部材２から出射する光はP偏波の光となって出射する。この時、使用される位相差板であるλ／４板としてはポリカーボネート基材を所望の厚さに延伸して得る。この時、延伸した基材の厚さは比視感度が高い５５０nmの１／４の１３７.５nmを基準にして決定する。発明者らは色再現性を新たな評価指標としてλ／４板の選択を行った。 <Reflective retroreflective member with high color reproducibility>
A cross-sectional structure of the retroreflective member 2 is shown in FIG. 1C. The retroreflective member 2 includes a reflective layer 2a, a transparent base material 2b, a reflective surface 2c, and a λ/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 λ/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. At this time, most of the light incident on the reflective layer 2a is transmitted, but some light is partially reflected. Therefore, for example, when the light incident on the retroreflective member 2 is S-polarized light, the light exiting from the retroreflective member 2 becomes P-polarized light. At this time, the λ/4 plate used as a retardation plate is obtained by stretching a polycarbonate base material to a desired thickness. At this time, 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 λ/4 plate using color reproducibility as a new evaluation index.
　図２は市販されている代表的なλ／４板の特性を示した特性図である。５５０nmの光を基準にした部分分散の異なる試料を用いて空間浮遊映像の色再現性を評価した。部分分散の理想直線に対して通常のポリカーボネート基材を延伸した正波長分散のλ／４板は４７０nm以下の青色領域の光に対して位相補正量が不足し偏光変換の効率が大幅に低下する。この結果、図１に示す空間浮遊像２２０として白色の空間浮遊像を表示した場合に黄色味を帯び白色となった。 FIG. 2 is a characteristic diagram showing the characteristics of a typical commercially available λ/4 plate. The color reproducibility of spatially floating images was evaluated using samples with different partial dispersions based on 550 nm light. A λ/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. . As a result, when a white spatial floating image is displayed as the spatial floating image 220 shown in FIG. 1, the color becomes white with a yellowish tinge.
　この白色浮遊映像の色温度は、ＬＥＤ光源の色温度に対しても大幅に低下することが分かった。次に図２に示すフラットな波長分散を有するλ／４板を用いた場合においても４７０nm以下の青色領域の光に対して位相補正量が不足するため白色の空間浮遊像を表示した場合に黄色味を帯び白色となった。更に図２に示すように基準波長の５５０nmより短波長側の波長領域において波長分散特性の理想直線に近い特性を示す逆波長分散特性を有する２種類のλ／４板（特性（ａ）および特性（ｂ））についても同様の評価を行った。 It was found that the color temperature of this white floating image was significantly lower than that of the LED light source. Next, even when using a λ/4 plate with flat wavelength dispersion as shown in Figure 2, the amount of phase correction is insufficient for light in the blue region of 470 nm or less, so when displaying a white spatially floating image, the image becomes yellow. It became white with a taste. Furthermore, as shown in Figure 2, two types of λ/4 plates (characteristic (a) and characteristic Similar evaluations were made for (b)).
　図３および図４に示す本発明の光源装置で使用する光源は、面発光の白色ＬＥＤで青色ＬＥＤを励起光として黄色の蛍光体を発光させ合成して白色光を発光させる構成である。図５に発光スペクトルを示す。 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.
　面発光の白色ＬＥＤからの光源光のうち青色光のピーク波長４５０nm以下の白色光の色温度を高い領域に引き上げるには青緑および青色領域において逆波長分散特性を有する特性（ａ）および特性（ｂ）の試料のうち白表示の空間浮遊映像の色度を高色温度方向に移動させ、より鮮やかな白表示が可能な特性は、白色ＬＥＤの光源光のうち青色領域のピーク波長４５０nmより短波長側の波長分散が小さいものが良く特性（ａ）試料の方が優れた性能を示した。また長波長側の波長分散も理想曲線に近いため赤色映像光の発色が改善した。 In order to raise the color temperature of white light with a peak wavelength of 450 nm or less of blue light from a surface-emitting white LED to a high range, characteristics (a) and (a) having reverse wavelength dispersion characteristics in the blue-green and blue regions are required. Among the samples in b), 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. In addition, the wavelength dispersion on the long wavelength side is close to the ideal curve, which improves the color development of red image light.
　この結果から図１Ｃに断面構造を示した空間浮遊映像表示装置に使用する反射型再帰反射部材の前面に配置したλ／４板２dを選択する優先順位は、(1)波長分散が理想直線に近い(2)特に青色領域の波長分散が理想直線より小さいほど有効(3)更にシステム全体の色再現性を向上である。このためには赤色領域、６５０nm以上の長波長領域の波長分散は理想直線に近づけると更によい。 Based on this result, the priority order for selecting the λ/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.
　＜空間浮遊映像表示システムを形成する第１の再帰反射光学系の構成例＞
　再び図１に戻って、本開示の空間浮遊映像表示システムを実現するために使用する再帰光学系の形態の一例を示す図である。また、図１は、本実施形態における空間浮遊映像表示システムの全体構成を説明する図である。 <Example of configuration of first retroreflective optical system forming spatial floating image display system>
Returning to FIG. 1 again, it 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.
　図１を参照すると、例えば、本開示の空間浮遊表示システム（以下、「本システム」ともいう）によれば、空間浮遊映像の観視者に対して空間浮遊映像表示システムを机上に配置した場合には空間浮遊映像を観下げることになる。この時、空間浮遊像の結像位置（角度）は、液晶表示パネル１１の表示面と特定偏波の映像光を反射するビームスプリッタとしての機能を有する反射型偏光板１０１と再帰反射部材２の配置となす角度で決まる。空間浮遊像が形成される位置は反射型偏光板１０１を対称面として再帰反射部材２の面対称の位置に結像する。 Referring to FIG. 1, for example, according to the spatial floating display system of the present disclosure (hereinafter also referred to as "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. At this time, 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.
　上述した空間浮遊映像の画質はフォーカス性能、輝度、明るさの他に、色再現範囲の拡大が今後の他社差別化の大きな武器になる。発明者らは液晶パネルを映像源として反射型の再帰反射部材を用いて得られる空中浮遊像の色再現性を拡大する具体的な技術手段について構成部品の性能の見直しを行った。 In addition to focus performance, brightness, and brightness, the image quality of the above-mentioned floating images will be a major weapon for differentiating ourselves from other companies in the future. The inventors reviewed the performance of component parts regarding a specific technical means for expanding the color reproducibility of an airborne image obtained using a reflective retroreflective member using a liquid crystal panel as an image source.
　図１に示す本開示の空間浮遊映像表示システムではゴースト像（図中ｇ1、ｇ２で示す）の発生を軽減するために液晶表示パネル１１の光源装置１３は狭発散角な指向特性として再帰反射する正規光以外の拡散光を軽減してゴースト像の発生を抑えている。更に、液晶表示パネル１１の光出射面または疎に近傍に映像光の拡散特性を制御する映像光制御シート１２を設ける。この結果、ゴースト像の発生を大幅に軽減できる。 In the spatial floating image display system of the present disclosure shown in FIG. 1, 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. Furthermore, 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.
　映像表示装置１からの特定偏波の映像光５００１は、透明性プレート１００の光入射面に設けた偏光ビームスプリッタとしての作用する反射型偏光板１０１で反射し、反射した光５００２は再帰反射部材２に入射する。再帰反射部材２の表面には位相差板としてλ／４板２ｄを設け再帰反射光が２度通過することで等価的にλ／２板として作用するため偏光変換され、再帰反射光５００３は前述した反射型偏光板１０１を対称軸とした位置に空間浮遊映像が結像する。外光が入射して再帰反射部材に入射することを防止するために透明性プレート１００と反射型偏光板１０１の間に偏光変換された偏波の映像光を透過する吸収型偏光板１０２を設けてもよい。 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. 2. A λ/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 λ/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. In order to prevent external light from entering the retroreflective member, 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.
　＜吸収型偏光板＞
　上述した透明性プレート１００に設ける一般的な吸収型偏光板の分光透過率を図８に示す。５００nm以下の青緑波長領域の透過率が５５０nm以上の長波長領域の透過率に比べて低いため図５に示した白色ＬＥＤの発光スペクトルのうち青色領域の吸収が大きく図１０に示す色度図の黒体軌跡に沿って白の色温度が低温側にシフトし色再現範囲は狭くなる。また、液晶表示パネル１１の光源側と映像光出射面側に貼合する偏光板の分光透過率を図８に示すが透過軸透過率は上述した一般的な吸収型偏光板と同様に、５００nm以下の青緑波長領域の透過率が５５０nm以上の長波長領域の透過率に比べて低いため図５に示した白色ＬＥＤの発光スペクトルのうち青色領域の吸収が大きく図１０に示す色度図の黒体軌跡に沿って白の色温度が低温側にシフトさせる。 <Absorption type polarizing plate>
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. In addition, FIG. 8 shows the spectral transmittance of the polarizing plate bonded to the light source side and the image light output side of the liquid crystal display panel 11, and the transmission axis transmittance is 500 nm, similar to the above-mentioned general absorption type polarizing plate. Since the transmittance in the following blue-green wavelength region is lower than the transmittance in the long wavelength region of 550 nm or more, the absorption in the blue region of the emission spectrum of the white LED shown in FIG. 5 is large, and the chromaticity diagram shown in FIG. The color temperature of white is shifted to the lower temperature side along the blackbody locus.
　図９は一般的な吸収型偏光板の構造を示すものでＰＶＡフィルムを特定方向に延伸させ染料により染色することで特定偏波に対しての偏光特性を制御する。このＰＶＡ（Polyvinyl alcohol）は親水性が高いため両側をＴＡＣ（Tri acetyl cellulose）フィルムで挟み込むことで水分吸収を押さえる構成としている。偏光特性を制御する染料は偏光度（透過軸透過率／吸収軸透過率）を向上させると５００nm以下の短波長の吸収が大きくなる。 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.
　本発明の空間浮遊映像表示システムの光学系においてはセット外部に対して空間浮遊像を結像するための映像光が通過する窓に設けた透明性プレート１００に設けた特定偏波の映像光を選択的に透過する吸収型偏光シート１０２は、特定偏波の映像光を透過する性質を有するので、特定偏波の映像光は、吸収型偏光シート１０２を透過する。透過した映像光により再帰反射部材２に対して対称位置に実像の空間浮遊映像２２０を形成する。 In the optical system of the spatial floating image display system of the present invention, 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.
　本開示の空間浮遊映像表示装置により、得られる空中浮遊映像２２０を形成する光は、再帰反射部材２から空中浮遊映像２２０の光学像へ収束する光線の集合であり、これらの光線は、空中浮遊映像２２０の光学像を通過後も直進する。よって、空中浮遊映像２２０は、一般的なプロジェクタなどでスクリーン上に形成される拡散映像光とは異なり、高い指向性を有する映像である。 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.
　図１１には空間浮遊映像表示装置の白色表示の際の色度を示す色度図を示す。図１２には空間浮遊映像表示装置の白色表示の際の色度を示す色度図にマクアダムの色弁別楕円を重ねた色度図を示す。人間の目視による色度変化（ＣＩＥのＸＹ色度座標系）に対する座標領域ごとの感度は図１１、図１２に示すＸＹ色度座標上の楕円の中心点からのずれ量で同色と認識する領域を示したマクアダム（Mac Adam）の等色楕円で表される。色温度が高いほど微妙な色度変化を認識する感度が高くなるため今後空間浮遊映像の色再現範囲を広げるために鮮やかな白色を基調とする場合には十分な注意が必要となる。 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.
　上述したように液晶表示パネルと反射型再帰反射部材を使用した光学系においては使用する反射型偏光板、透過型偏光板、液晶表示パネルに貼合された透過型偏光板の５００nm以下の青緑波長領域における分光透過率が緑赤領域の波長に対するものに比べ低いため本発明の実施例で用いる反射型再帰反射部材の表面に貼合したλ／４板は逆波長分散特性を有するものを使用することが白色の再現性を確保するためには必須となる。 As mentioned above, in an optical system using a liquid crystal display panel and a reflective retroreflective member, 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 λ/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.
　また図１に示す本発明の実施例の構成では、図中に示す方向からユーザが視認する場合には空中浮遊映像２２０は明るい映像として視認されるが紙面の上下方向および前後方向から他の人物が視認する場合には、空中浮遊映像２２０は映像として一切視認することはできない。この特性は、高いセキュリティが求められる映像や、ユーザに正対する人物には秘匿したい秘匿性の高い映像を表示するシステムに採用する場合に、非常に好適である。 In addition, in the configuration of the embodiment of the present invention shown in FIG. 1, 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.
　なお、再帰反射部材２の性能によっては、反射後の映像光の偏光軸が不揃いになることがある。この場合、偏光軸が不揃いになった一部の映像光は、上述した吸収型偏光シート１０２で吸収される。このため再帰反射光学系で不要な反射光が発生せず、空間浮遊像の画質の低下を防止ないし抑制することができる。 Note that depending on the performance of the retroreflective member 2, 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.
　また、本開示の再帰反射光学システムを用いた空間浮遊映像表示装置では、観視者が空間浮遊映像を覗き込んだ場合にも映像表示装置１の表示画面が再帰反射部材２の反射面で遮光される。そのため、この空間浮遊映像表示装置では、映像表示装置１と再帰反射部材が正対した場合に比べて、映像表示装置１が観視側に配置しているため表示画像は直接的には観難くなる。 Furthermore, in the spatially floating image display device using the retroreflective optical system of the present disclosure, even when the viewer looks into the spatially floating image, 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.
更に、液晶表示パネル１１からの映像光は再帰反射部材等の反射部材での反射率を原理的に高くできるのでＳ偏波を使用するとよいが、観視者が偏光サングラスを使用した場合に空中浮遊像が偏光サングラスで反射または吸収されるため、この対策として特定偏波の映像光の一部を光学的に他方の偏波に変換して疑似的に自然光に変換する偏光解消素子１０３を設けてもよい。この結果、観視者が偏光サングラスを使用していても良好な空間浮遊映像を観視することができる。透明性プレート１００と粘着剤によって光学的に接合されると光の反射面が発生せず空間浮遊像の画質を損なわない。 Furthermore, it is preferable to use S-polarized light because the image light from the liquid crystal display panel 11 can theoretically increase the reflectance on reflective members such as retroreflective members. Since floating images are reflected or absorbed by polarized sunglasses, as a countermeasure, a depolarization element 103 is provided 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.
　偏光解消素子の市販品としては、コスモシャインＳＲＦ（東洋紡社製）、偏光解消粘着剤（長瀬産業社製） が挙げられる。コスモシャインＳＲＦ（東洋紡社製）の場合、画像表示装置上に粘着剤を貼合することにより、界面の反射を低減して輝度を向上させることができる。また、偏光解消粘着剤の場合、無色透明板と画像表示装置とを、偏光解消粘着剤を介して貼合することで使用される。本実施例では前述したように映像表示装置１は、液晶表示パネル１１と挟角な拡散特性を有する特定偏波の光を生成する光源装置１３を備えている。 Commercially available depolarization elements include Cosmoshine SRF (manufactured by Toyobo Co., Ltd.) and depolarization adhesive (manufactured by Nagase Sangyo Co., Ltd.). In the case of Cosmoshine SRF (manufactured by Toyobo Co., Ltd.), by laminating an adhesive onto the image display device, reflection at the interface can be reduced and brightness can be improved. Further, in the case of a depolarizing adhesive, it is used by bonding a colorless transparent plate and an image display device via the depolarizing adhesive. In this embodiment, as described above, 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.
　　＜映像光制御シート＞
　上述した映像表示装置１において画面垂直方向と画面水平方向の拡散特性を異なるものとするために、液晶表示パネル１１の映像光出射面に映像光制御シートを設ける。映像光制御シート１２は、液晶表示パネル１１から出射する映像光束の出射方向と発散角を調整する。この映像光制御シートとして、例えば、信越ポリマー（株）の視野角制御フィルム（ＶＣＦ）が適しており、その構造は透明シリコンと黒色シリコンを交互に配置し光入出射面に合成樹脂を配置してサンドウィッチ構造としているため、本実施例の外光制御フィルムと同様の効果が期待できる。この時、視野角制御フィルム（ＶＣＦ）は、所定の方向に延伸する透明シリコンと黒色シリコンが交互に配列されているため、液晶表示パネル１１の画素の配列方向の上下方向に対して映像光制御シート１２の透明シリコンと黒色シリコンの延伸方向を傾けることで、画素と外光制御フィルムのピッチで発生するモアレを軽減するように配置するとよい。 <Image light control sheet>
In order to have different diffusion characteristics in the screen vertical direction and the screen horizontal direction in the video display device 1 described above, 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. For example, 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. At this time, 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.
　（１）映像光制御シートの透過部と光吸収部により生じる縦縞と液晶パネル１１の画素の配列により生じるモアレを低減するためには前述の縦縞と画素配列を傾けて配置するとよい。更に、（２）液晶パネル１１の画素寸法をＡとし、映像光制御シート１２の縦縞のピッチをＢとした場合、この比率（Ｂ／Ａ）を整数倍から外して選択すると更にモアレ低減の効果がある。 (1) In order to reduce vertical stripes caused by the transmitting portions and light absorbing portions of the image light control sheet and moiré caused by the pixel arrangement of the liquid crystal panel 11, it is preferable to arrange the vertical stripes and the pixel arrangement at an angle. Furthermore, (2) If the pixel size of the liquid crystal panel 11 is A, and the pitch of the vertical stripes of the image light control sheet 12 is B, then if this ratio (B/A) is selected outside of an integral multiple, the moire reduction effect will be further improved. There is.
　液晶パネル１１の１画素はＲＧＢの３色の画素が並列してより成り、一般的には正方形であるため上述したモアレの発生を画面全体で抑えることはできない。このため、（１）に示した傾きを持たせた配置として、空間浮遊映像を表示させない場所にモアレの発生位置を意図的にずらして配置できるように、５度から２５度の範囲で最適化すればよいことを実験的に求めた。モアレを低減するために液晶パネルを題材に述べたが、再帰反射部材２と映像光制御シート１２の間に発生するモアレは両者が線条の構造体であるために発生するもので、映像光制御シートを液晶パネルの画素並びに対して最適に傾けることで、目視でも視認できる周波数の低い大柄なモアレを低減できる。 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. In order to reduce moire, 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 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.
　映像光制御シート１２は図１に示すように液晶パネル１１の映像光出射面に配置し粘着材により液晶パネル１１の映像光出射面に粘着固定される。また、空間浮遊映像から拡散される映像光束の拡散角と拡散方向は、映像光制御シート１２の拡散特性と光源装置１３の拡散特性により調整される。映像光制御シート１２の拡散特性とは、所定の方向に延伸する透明シリコンと黒色シリコンが交互に配列されているため、液晶表示パネル１１の画素の配列方向の上下方向に対して映像光制御シート１２の透明シリコンと黒色シリコンの延伸方向を傾けることで、画素と外光制御フィルムのピッチで発生するモアレを軽減することである。また、光源装置１３の拡散特性とは、図１３Ｂ（２）に示す反射型導光体３０６に設けた反射面３０７の構成を１面に複数の傾きを持つような構成とすることで、より高精度に反射光を調整することである。なお、反射面において、１面に複数の傾きを持つような構成としては、反射面として使用する領域が、複数面または多面または曲面でもよい。反射面３０７には、図１３Ｂに示したように、リフレクタ３００からの平行光束φ５（Ｒ７～Ｒ１０）はその進行方向において、傾きの異なる複数の面（Ｐ７～Ｐ１０）で反射され、それぞれに対応した液晶パネル部分に向かう。 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. Furthermore, 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. In addition, in the case of a configuration in which the reflective surface has a plurality of inclinations on one surface, the region used as the reflective surface may be a plurality of surfaces, a polysurface, or a curved surface. As shown in FIG. 13B, on the reflecting surface 307, the parallel light beam φ5 (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.
　＜液晶パネルの性能＞
　ところで、一般的なＴＦＴ（Thin Film Transister）液晶パネルは、光の出射方向によって液晶と偏光板相互の特性により輝度、コントラスト性能が異なる。図２２に示した測定環境での評価では、パネル短手（上下）方向での輝度と視野角の特性は図２４に示すようにパネル面に垂直（出射角度０度）な出射角より少しずれた角度での特性（本実施例では＋５度）が優れている。この理由は、液晶パネルの短手（上下）方向では、光をねじる特性が印加電圧最大の時に０度とならないためである。 <LCD panel performance>
By the way, in a typical TFT (Thin Film Transister) liquid crystal panel, the brightness and contrast performance differ depending on the mutual characteristics of the liquid crystal and the polarizing plate depending on the direction in which light is emitted. In the evaluation in the measurement environment shown in Figure 22, the brightness and viewing angle characteristics in the transverse (up and down) direction of the panel were slightly different from the emission angle perpendicular to the panel surface (output angle 0 degrees) as shown in Figure 24. The characteristics at a different angle (+5 degrees in this example) are excellent. The reason for this is that in the transverse (vertical) direction of the liquid crystal panel, the characteristic of twisting light does not become 0 degrees when the applied voltage is maximum.
　他方、パネル短手（上下）方向のコントラスト性能は、図２６に示すように、－１５度から＋１５度の範囲が優れており、輝度特性と合わせると、５度を中心にして±１０度の範囲での使用が最も優れた特性を得ることとなる。 On the other hand, 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.
　また、パネル長手（左右）方向での輝度と視野角の特性は、図２３に示すように、パネル面に垂直（出射角度０度）な出射角での特性が優れている。この理由は、液晶パネルの長手（左右方向）では光をねじる特性が印加電圧最大の時に０度となるためである。 Furthermore, as shown in FIG. 23, 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.
　同様に、パネル長手（左右）方向のコントラスト性能は図２５に示すように、－５度から－１０度の範囲が優れており、輝度特性と合わせると－５度を中心にして±５度の範囲での使用が最も優れた特性を得ることとなる。このため、液晶パネルから出射する映像光の出射角度は、前述した光源装置１３の導光体に設けた光束方向変換手段により最も優れた特性が得られる方向から液晶パネルに光を入射させ、映像信号により光変調することが、映像表示装置１の画質と性能を向上させることになる。 Similarly, 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. For this reason, 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.
　映像表示素子としての液晶パネルの輝度、コントラスト特性を最大限に生かすためには、光源からの液晶パネルへの入射光を上述した範囲に設定することで、空間浮遊映像の映像品位を向上することができる。 In order to make the most of the brightness and contrast characteristics of the liquid crystal panel as a video display element, it is necessary to set the incident light from the light source to the liquid crystal panel within the above-mentioned range to improve the image quality of the floating image. Can be done.
　＜光源光の制御方法＞
　本実施例では、光源装置１３からの出射光束の利用効率を向上させ、消費電力を大幅に低減するために、光源装置１３と液晶表示パネル１１を含んで構成される映像表示装置１において、光源装置１３からは液晶パネル１１の特性が最大となるような入射角度で液晶パネル１１に入射後、映像信号に合わせて輝度変調された映像光線を再帰反射部材に向けて出射させる。この時、空間浮遊映像表示システムのセット容積を小型化するために、液晶パネル１１と再帰反射部材の配置の自由度を高めることが要望される。更に、再帰反射後、浮遊映像を所望の位置に形成し最適な指向性を確保するため、以下の技術手段を用いる。 <How to control light source light>
In this embodiment, in order to improve the utilization efficiency of the luminous flux emitted from the light source device 13 and significantly reduce power consumption, 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. At this time, 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. Furthermore, in order to form a floating image at a desired position after retroreflection and ensure optimal directivity, the following technical means are used.
　液晶パネル１１の映像表示面には、光方向変換パネルとして、リニアフレネルレンズ等の光学部品からなる透明シートを設け、高い指向性を付与したまま再帰反射光学部材への入射光束の出射方向を制御して空間浮遊映像の結像位置を決定する。この構成によれば、映像表示装置１からの映像光は、レーザ光のように観察者に対して高い指向性（直進性）で効率良く届くこととなり、その結果、高品位な浮遊映像を高解像度で表示すると共に、光源装置１３を含む映像表示装置１による消費電力を大幅に低減することが可能となる。 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. According to this configuration, 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.
　＜映像表示装置の例１＞
　図１７には、映像表示装置１の具体的な構成の他の一例を示す。図１７の光源装置１３は、図１７等の光源装置と同様である。この光源装置１３は、例えばプラスチックなどのケース内にＬＥＤ、コリメータ、合成拡散ブロック、導光体等を収納して構成されており、その上面には液晶表示パネル１１が取り付けられている。また、光源装置１３のケースの１つの側面には、半導体光源であるＬＥＤ（Light Emitting Diode）素子１４ａ、１４ｂや、その制御回路を実装したＬＥＤ基板が取り付けられると共に、ＬＥＤ基板の外側面には、ＬＥＤ素子および制御回路で発生する熱を冷却するための部材であるヒートシンクが取り付けられる（図示せず）。 <Example 1 of video display device>
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. Further, on one side of the case of the light source device 13, 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).
　また、ケースの上面に取り付けられた液晶表示パネルフレームには、当該フレームに取り付けられた液晶表示パネル１１と、更に、液晶表示パネル１１に電気的に接続されたＦＰＣ（Flexible Printed Circuits:フレキシブル配線基板）（図示せず）などが取り付けられて構成されている。すなわち、液晶表示素子である液晶表示パネル１１は、固体光源であるＬＥＤ素子１４ａ，１４ｂと共に、電子装置を構成する制御回路（ここでは図示せず）からの制御信号に基づいて、透過光の強度を変調することによって、表示映像を生成する。 In addition, 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 .
　＜映像表示装置の例１の光源装置の例１＞
　続いて、ケース内に収納されている光源装置等の光学系の構成について、図１６と共に、図１７（ａ）および（ｂ）を参照しながら、詳細に説明する。図１６および図１７には、光源７構成するＬＥＤ１４ａ、１４ｂが示されており、これらはコリメータ１５に対して所定の位置に取り付けられている。なお、このコリメータ１５は、各々、例えばアクリル等の透光性の樹脂により形成されている。そして、このコリメータ１５は、図１７（ｂ）にも示すように、放物断面を回転して得られる円錐凸形状の外周面１５６を有すると共に、その頂部（ＬＥＤ基板に接する側）におけるその中央部に、凸部（すなわち、凸レンズ面）１５７を形成した凹部１５３を有する。 <Example 1 of light source device of Example 1 of video display device>
Next, the configuration of the optical system such as the light source device housed in the case will be described in detail with reference to FIGS. 17(a) and 17(b) as well as FIG. 16. 16 and 17 show LEDs 14a and 14b constituting the light source 7, which are attached to a predetermined position relative to the collimator 15. Note that each of the collimators 15 is made of a translucent resin such as acrylic. As shown in FIG. 17(b), 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.
　また、コリメータ１５の平面部（上記の頂部とは逆の側）の中央部には、外側に突出した凸レンズ面（あるいは、内側に凹んだ凹レンズ面でもよい）１５４を有している。なお、コリメータ１５の円錐形状の外周面を形成する放物面１５６は、ＬＥＤ１４ａ、１４ｂから周辺方向に出射する光をその内部で全反射することが可能な角度の範囲内において設定され、あるいは、反射面が形成されている。 In addition, 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). Note that 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.
　また、ＬＥＤ１４ａ、１４ｂは、その回路基板である、基板１０２の表面上の所定の位置にそれぞれ配置されている。この基板１０２は、コリメータ１５に対して、その表面上のＬＥＤ１４ａまたは１４ｂが、それぞれ、その凹部１５３の中央部に位置するように配置されて固定される。 Further, 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.
　かかる構成によれば、上述したコリメータ１５によって、ＬＥＤ１４ａまたは１４ｂから放射される光のうち、特に、その中央部分から上方（図の右方向）に向かって放射される光は、コリメータ１５の外形を形成する２つの凸レンズ面１５７、１５４により集光されて平行光となる。また、その他の部分から周辺方向に向かって出射される光は、コリメータ１５の円錐形状の外周面を形成する放物面によって反射され、同様に、集光されて平行光となる。換言すれば、その中央部に凸レンズを構成すると共に、その周辺部に放物面を形成したコリメータ１５によれば、ＬＥＤ１４ａまたは１４ｂにより発生された光のほぼ全てを平行光として取り出すことが可能となり、発生した光の利用効率を向上することが可能となる。 According to this configuration, among the light emitted from the LED 14a or 14b by the collimator 15 described above, 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. Further, 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. In other words, with 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.
　なお、コリメータ１５の光の出射側には、偏光変換素子２１が設けられている。偏光変換素子２１は、偏光変換部材と称してもよい。この偏光変換素子２１は、図１７（ａ）からも明らかなように、断面が平行四辺形である柱状（以下、平行四辺形柱）の透光性部材と、断面が三角形である柱状（以下、三角形柱）の透光性部材とを組み合わせ、コリメータ１５からの平行光の光軸に対して直交する面に平行に、複数、アレイ状に配列して構成されている。更に、これらアレイ状に配列された隣接する透光性部材間の界面には、交互に、偏光ビームスプリッタ（以下、「ＰＢＳ膜」と省略する）２１１と反射膜２１２とが設けられており、また、偏光変換素子２１へ入射してＰＢＳ膜２１１を透過した光が出射する出射面には、λ／２位相板２１３が備えられている。 Note that 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. As is clear from FIG. 17(a), 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. Furthermore, 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 λ/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.
　この偏光変換素子２１の出射面には、更に、図１７（ａ）にも示す、矩形状の合成拡散ブロック１６が設けられている。すなわち、ＬＥＤ１４ａまたは１４ｂから出射された光は、コリメータ１５の働きにより平行光となって合成拡散ブロック１６へ入射し、出射側のテクスチャー１６１により拡散された後、導光体１７に到る。 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.
　導光体１７は、例えばアクリル等の透光性の樹脂により断面が略三角形（図１７（ｂ）参照）の棒状に形成された部材であり、そして、図４からも明らかなように、合成拡散ブロック１６の出射面に第１の拡散板１８ａを介して対向する導光体光入射部（面）１７１と、斜面を形成する導光体光反射部（面）１７２と、第２の拡散板１８ｂを介して、液晶表示素子である液晶表示パネル１１と対向する導光体光出射部（面）１７３と、を備えている。 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 incident part (surface) 171 facing the output surface of the diffusion block 16 via the first diffuser plate 18a, a light guide light reflection part (surface) 172 forming a slope, and a second diffuser. 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.
　この導光体１７の導光体光反射部（面）１７２には、その一部拡大図である図１６にも示すように、多数の反射面１７２ａと連接面１７２ｂとが交互に鋸歯状に形成されている。そして、反射面１７２ａ（図では右上がりの線分）は、図において一点鎖線で示す水平面に対してαｎ（ｎ:自然数であり、本例では、例えば、１～１３０である）を形成しており、その一例として、ここでは、αｎを４３度以下（ただし、０度以上）に設定している。 As shown in FIG. 16, which is a partially enlarged view, 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 αn (n: a natural number, for example, 1 to 130) with respect to the horizontal plane indicated by the dashed line in the figure. As an example, here αn is set to 43 degrees or less (however, 0 degrees or more).
　導光体入射部（面）１７１は、光源側に傾斜した湾曲の凸形状に形成されている。これによれば、合成拡散ブロック１６の出射面からの平行光は、第１の拡散板１８ａを介して拡散されて入射し、図からも明らかなように、導光体入射部（面）１７１により上方に僅かに屈曲（偏向）しながら導光体光反射部（面）１７２に達し、ここで反射して図の上方の出射面に設けた液晶表示パネル１１に到る。 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.
　以上に詳述した映像表示装置１によれば、光利用効率やその均一な照明特性をより向上すると同時に、モジュール化されたＳ偏光波の光源装置を含め、小型かつ低コストで製造することが可能となる。なお、上記の説明では、偏光変換素子２１をコリメータ１５の後に取り付けるものとして説明したが、本発明はそれに限定されることなく、液晶表示パネル１１に到る光路中に設けることによっても同様の作用・効果が得られる。 According to the video display device 1 described in detail above, 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. In the above explanation, 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.
　なお、導光体光反射部（面）１７２には、多数の反射面１７２ａと連接面１７２ｂとが交互に鋸歯状に形成されており、照明光束は、各々の反射面１７２ａ上で全反射されて上方に向かい、更には、導光体光出射部（面）１７３には挟角拡散板を設けて略平行な拡散光束として指向特性を調整する光方向変換パネル５４に入射し、斜め方向から液晶表示パネル１１へ入射する。この映像表示装置１の出射光は光源装置１３の上面に設けた光方向変換パネル５４により出射方向を制御される。その結果、液晶表示パネル１１からの出射光も制御され、この映像表示装置１を用いた空間浮遊映像表示システムにより得られる空間浮遊映像の光拡散方向が制御される。本実施例では光方向変換パネル５４を導光体出射面１７３と液晶表示パネル１１の間に設けたが、液晶表示パネル１１の出射面に設けても、同様の効果が得られる。 Note that 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. As a result, 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. In this embodiment, 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.
　液晶表示パネル１１からの出射光は、一般的なＴＶ用途の装置では、例えば図２０（Ａ）中の「従来特性（Ｘ方向）」および図２０（Ｂ）中の「従来特性（Ｙ方向）」のプロット曲線に示すように、画面水平方向（図２０（Ａ）のグラフのＸ軸に対応した表示方向）と画面垂直方向（図２０（Ｂ）のグラフのＹ軸に対応した表示方向）とで、互いに同様な拡散特性を有する。 In a device for general TV use, 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). '', the screen horizontal direction (the display direction corresponding to the X-axis of the graph in FIG. 20(A)) and the screen vertical direction (the display direction corresponding to the Y-axis of the graph in FIG. 20(B)) and have similar diffusion characteristics.
　これに対して、本実施例の液晶表示パネルからの出射光束の拡散特性は、例えば図２０（Ａ）中の「例１（Ｘ方向）」および図２０（Ｂ）中の「例１（Ｙ方向）」のプロット曲線に示すような拡散特性となる。 On the other hand, 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)''.
　一具体例では、正面視（角度０度）の輝度に対して５０％の輝度（約半分に低下する輝度）になる視野角が１３度となるように設定した場合、一般的な家庭用のＴＶ用途の装置の拡散特性（角度６２度）に対して約１／５の角度となる。同様に、垂直方向の視野角を上側と下側とで不均等に設定する場合の一例では、上側の視野角を下側の視野角に対して１／３程度に抑える（狭くする）ように、反射型導光体の反射角度や反射面の面積等を最適化する。 In one specific example, if 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. Similarly, in an example where the vertical viewing angle is set unevenly between the upper and lower sides, 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.
　上記のような視野角等の設定が行われることにより、従来の液晶ＴＶに比べ、ユーザの観視方向に向かう映像の光量が格段に増加（映像の明るさの点で大幅に向上）し、かかる映像の輝度は５０倍以上となる。 By setting the viewing angle, etc. as described above, compared to conventional LCD TVs, 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.
　更に、図２０の「例２」に示す視野角特性とした場合、正面視（角度０度）で得られる映像の輝度に対して５０％の輝度（約半分に低下する輝度）になる視野角が５度となるように設定した場合、一般的な家庭用のＴＶ用途の装置の拡散特性（角度６２度）に対して約１／１２の角度（狭い視野角）となる。同様に、垂直方向の視野角を上側と下側とで均等に設定する場合の一例では、かかる垂直方向の視野角を従来に対して１／１２程度に抑える（狭くする）ように、反射型導光体の反射角度と反射面の面積等を最適化する。 Furthermore, in the case of the viewing angle characteristics shown in "Example 2" in FIG. 20, 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. Similarly, in an example where the vertical viewing angle is set equally on the upper and lower sides, reflective type Optimize the reflection angle of the light guide and the area of the reflection surface.
　このような設定が行われることにより、従来の液晶ＴＶに比べ、観視方向（ユーザの視線方向）に向かう映像の輝度（光量）が大幅に向上し、かかる映像の輝度は１００倍以上となる。 By making these settings, 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. .
　以上述べたように、視野角を挟角とすることで、観視方向に向かう光束量を集中できるので、光の利用効率が大幅に向上する。この結果、一般的なＴＶ用途の液晶表示パネルを使用しても、光源装置の光拡散特性を調整することで同様な消費電力で大幅な輝度向上が実現可能で、明るい屋外に向けての表示システムに対応した映像表示装置とすることができる。 As described above, by making 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. As a result, even if a liquid crystal display panel for general TV use is used, by adjusting 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.
　大型の液晶表示パネルを使用する場合には、画面周辺の光は画面中央を観視者が正対した場合に観視者の方向に向かうように内側に向けることで、画面明るさの全面性が向上する。図２１は、液晶表示パネルから観視者までの距離Ｌと、映像表示装置のパネルサイズ（画面比１６:１０）と、をパラメータとした時の液晶表示パネル長辺と液晶表示パネル短辺との収斂角度を求めたもので上側に示す図では、液晶表示パネルの画面を縦長（以下、「縦使い」とも称する）として映像を観視する場合を前提としている。この場合には、液晶表示パネルの短辺（適宜、図２０中の矢印Ｖ方向を参照）に合わせて収斂角度を設定すればよい。 When using a large LCD panel, the light around the screen is directed inward toward the viewer when the center of the screen is directly facing the viewer, thereby increasing the overall brightness of the screen. will improve. 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. In the diagram shown above, which shows the convergence angle of , it is assumed that the image is viewed with the screen of the liquid crystal display panel in portrait orientation (hereinafter also referred to as "portrait usage"). In this case, 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).
　より具体的な例としては、図２１中のプロットグラフに参照されるように、例えば、２２”パネルの縦使いで観視距離が０.８ｍの場合には、収斂角度を１０度に設定することにより、画面の各隅（４コーナ）からの映像光を、観視者に向けて効果的に投射ないし出力することができる。 As a more specific example, as shown in the plot graph in FIG. 21, for example, when a 22" panel is used vertically and the viewing distance is 0.8 m, the convergence angle is set to 10 degrees. As a result, image light from each corner (four corners) of the screen can be effectively projected or output toward the viewer.
　同様に、１５”パネルの縦使いで観視する場合には観視距離が０.８ｍの場合には収斂角度を７度とすれば画面４コーナからの映像光を有効に観視者に向けることができる。以上述べたように、液晶表示パネルのサイズおよび縦使いか横使いかによって画面周辺の映像光を、画面中央を観視するのに最適な位置にいる観視者に向けることで、画面明るさの全面性を向上できる。 Similarly, when viewing a 15" panel vertically and the viewing distance is 0.8m, setting the convergence angle to 7 degrees will effectively direct the image light from the four corners of the screen toward the viewer. As mentioned above, depending on the size of the LCD panel and whether it is used vertically or horizontally, the image light around the screen can be directed to the viewer who is in the optimal position to view the center of the screen. , the overall screen brightness can be improved.
　基本構成としては、上述の図２０などに示すように、光源装置により挟角な指向特性の光束を液晶表示パネル１１に入射させ、映像信号に合わせて輝度変調することで、液晶表示パネル１１の画面上に表示した映像を、再帰反射部材で反射させ得られた空間浮遊映像を、透明な部材１００を介して室外または室内に表示する。 As shown in FIG. 20, 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.
　以下、光源装置の別の例について複数の例を説明する。これらの光源装置の別の例は、いずれも上述した映像表示装置の例の光源装置に変えて採用してもよい。 Hereinafter, a plurality of other examples of the light source device will be described. Any of these other examples of the light source device may be adopted in place of the light source device of the example of the video display device described above.
　大型の液晶表示パネルを使用する場合には上述したように、画面周辺の光は画面中央を観視者が正対した場合に観視者の方向に向かうように内側に向けることで、画面明るさの全面性が向上するが、他方、観視者の左右の目のどちらで視認するかにより両眼視差が発生する。図２１は、液晶表示パネルから観視者までの距離Ｌと、映像表示装置のパネルサイズ（画面比１６:１０）をパラメータとした時の液晶表示パネル長辺と液晶表示パネル短辺との収斂角度を左右の目の位置を基準として求めたものである。 When using a large LCD panel, as mentioned above, the brightness of the screen can be increased by directing the light around the screen inward toward the viewer when the center of the screen is directly facing the viewer. However, on the other hand, binocular parallax occurs depending on whether the viewer uses the left or right eye to view the image. 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.
　パネルサイズが小型な程、観視距離が近いほど左右の目による両眼視での収斂角は大きくなる。特に7インチ以下の小型パネルを使用する場合には、両眼視差による収斂角度は重要な要件となるため、例えば７インチ以下の場合、図１９に示した光源の光拡散特性を拡大するか指向特性を持たせて、システムの最適観に映像光が向くように設計する。 The smaller the panel size and the closer the viewing distance, the larger the convergence angle in binocular vision between the left and right eyes. In particular, when using a small panel of 7 inches or less, the convergence angle due to binocular parallax 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.
　更に、システムの要求仕様によっては、水平と垂直の指向特性、拡散特性を得るために、前述した光源装置１３の導光体の反射面の形状、面粗さ、傾きなどを最適設計する必要がある。 Furthermore, depending on the required specifications of the system, it is necessary to optimally design the shape, surface roughness, inclination, etc. of the reflective surface of the light guide of the light source device 13 in order to obtain horizontal and vertical directivity characteristics and diffusion characteristics. be.
　＜光源装置の例１＞
　次に、図３を参照して、光源装置の別の例について説明する。図３（ａ）および（ｂ）は、導光体３１１を説明するために、液晶表示パネル１１と拡散板２０６の一部を省略した図である。 <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.
　図３は、光源を構成するＬＥＤ１４が基板１０２に備え付けられた状態を示している。これらＬＥＤ１４および基板１０２は、リフレクタ３００に対して所定の位置に取り付けられている。 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.
　図３（ａ）に示すように、ＬＥＤ１４は、リフレクタ３００が配置される側の液晶表示パネル１１の辺（この例では短辺）と平行な方向に、一列に配置される。図示の例では、かかるＬＥＤの配置と対応して、リフレクタ３００が配置されている。なお、リフレクタ３００は複数配置されてもよい。 As shown in FIG. 3(a), 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. In the illustrated example, a reflector 300 is arranged corresponding to the arrangement of the LEDs. Note that a plurality of reflectors 300 may be arranged.
　一具体例では、リフレクタ３００は、各々、プラスチック材料により形成されている。他の例として、リフレクタ３００は、金属材料やガラス材料で形成してもよいが、プラスチック材料の方が成型しやすいため、本実施例ではプラスチック材料のものを用いる。 In one embodiment, the reflectors 300 are each formed from a plastic material. As another example, 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.
　図３（ｂ）に示すように、リフレクタ３００の内側（同図中の右側）の面は、放物面を子午面で切り取った形状の反射面（以下は「放物面」と称する場合がある）３０５を備える。リフレクタ３００は、ＬＥＤ１４から出射される発散光を、上記の反射面３０５（放物面）で反射させることにより、略平行な光に変換し、変換された光を導光体３１１の端面に入射させる。リフレクタ３００の反射面にはアルミ反射膜の他に増反射膜としてＴｉ、ＳｉＯなどの金属膜を複数成膜して図６に示すように反射率を高めかつ入射角度の依存性も低減する設計とした。一具体例では、導光体３１１は、反射型導光体である。 As shown in FIG. 3(b), 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. let In addition to the aluminum reflective film, 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. In one specific example, light guide 311 is a reflective light guide.
　リフレクタ３００の反射面は、ＬＥＤ１４の出射光の光軸に対して非対称な形状である。また、リフレクタ３００の反射面３２１は、上述のように放物面であり、かかる放物面の焦点にＬＥＤを配置することで、反射後の光束を略平行光に変換する。 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.
　ＬＥＤ１４は面光源であるため放物面の焦点に配置してもＬＥＤからの発散光を完全な平行光に変換することはできないが、本願発明の光源の性能を左右することはない。ＬＥＤ１４とリフレクタ３００は一対のペアである。また、ＬＥＤ１４の基板１０２への取り付け精度±４０μｍにおいて所定の性能を確保するためには、ＬＥＤの基板の取り付けは最大１０個以下とすべきであり、量産性を考慮すれば５個程度に抑えるとよい。 Since 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. In addition, in order to ensure the specified performance with the mounting accuracy of the LED 14 on the board 102 of ±40 μm, 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.
　ＬＥＤ１４とリフレクタ３００は一部において近接されるがリフレクタ３００の開口側の空間へ放熱できるためＬＥＤの温度上昇が低減できる。このため、プラスチック成型品のリフレクタ３００が使用可能となる。その結果、このリフレクタ３００によれば、反射面の形状精度をガラス素材のリフレクタに比べ１０倍以上向上できるので、光利用効率を向上させることができる。 Although 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.
　一方、図３（ｂ）に示すように、導光体３１１の底面３０３には反射面が設けられ、ＬＥＤ１４からの光はリフレクタ３００により平行光束に変換された後、当該反射面で反射し、導光体３１１に対向して配置された液晶表示パネル１１に向け出射する。底面３０３に設けられた反射面には、図３に示したように、リフレクタ３００からの平行光束φ２の進行方向において、傾きの異なる複数の面があってもよい。傾きの異なる複数の面のそれぞれの面はリフレクタ３００からの平行光束の進行方向に垂直な方向に延伸する形状を有してもよい。 On the other hand, as shown in FIG. 3(b), 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 . As shown in FIG. 3, 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 φ2 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.
　また、図３に示すように底面３０３に設けられた反射面の形状は平面形状でもよい。更に、液晶表示パネル１１に対向した導光体３１１の底面３０３に設けた反射面で反射された光の拡散特性をより高精度に制御するため拡散板２０６を設けてもよい。 Further, as shown in FIG. 3, the shape of the reflective surface provided on the bottom surface 303 may be a planar shape. Further, 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.
　この拡散板は両面の面形状と面粗さにより、前述の反射光を一旦屈折させて液晶表示パネル１１に向かう光束の光量と出射方向を高精度に調整できるので液晶表示パネル１１への入射光および液晶表示パネル１１からの出射光の光量および出射方向も同様に高精度に制御できる。このため、この光源を用いた映像表示装置を用いた空間映像表示システムにおいては、空間浮遊映像の映像光の拡散方向と拡散角を所望の値に設定できる。この時反射面に設けた反射膜もアルミ反射膜にＴｉ、ＳｉＯの増反射膜を加えることで図７に示すような高い反射率と反射率の入射角度角度依存性を低減する設計とするとよい。 Due to the surface shape and surface roughness of both sides, 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. At this time, 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. .
　以上述べたアルミ反射膜は５００nm以下の青緑波長領域の反射率が緑赤領域の反射率に対して低いので増反射膜の設計においては反射率の入射角度依存性低減と色再現性の向上のために白の純度向上も重要な課題となる。 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.
　図３に示すようにＬＥＤ１４は、金属性の基板１０２に半田付けする。このためＬＥＤの発熱を、基板を介して空気中に放熱することができる。また、基板１０２にリフレクタ３００が接していてもよいが、空間を開けておいてもよい。空間を開ける場合、リフレクタ３００は筐体に接着させて配置される。空間を開けておくことで、ＬＥＤの発熱を空気中に放熱でき、冷却効果が上がる。この結果、ＬＥＤの動作温度が低減できるので、発光効率の維持と長寿命化を実現することができる。 As shown in FIG. 3, 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. Further, although 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.
　＜光源装置の例２＞
　以上説明した光源装置においても偏光変換素子２１を用いることで光利用効率を１.８倍向上することができる。以下にこの光源装置に関する光学系の構成について、図１３Ａおよび図１３Ｂおよび図１３Ｃおよび図１３Ｄを参照しながら詳細に説明する。なお、図１３Ａにおいてサブリフレクタ３０８の図示は省略している。 <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.
　図１３Ａ、図１３Ｂおよび図１３Ｃは、光源を構成するＬＥＤ１４が基板１０２に備え付けられた状態を示しており、これらはリフレクタ３００とＬＥＤ１４を一対のブロックとし、複数のブロックを有するユニット３１２で構成する。 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. .
　このうち、図１３Ａ（２）に示した基材３２０は、基板１０２の基材である。一般に、金属性の基板１０２は熱を持っているため、かかる基板１０２の熱を絶縁（断熱）するために、基材３２０は、プラスチック材料などを用いてもよく、放熱性を高めるため金属部材としてもよい。 Among these, the base material 320 shown in FIG. 13A(2) is the base material of the substrate 102. In general, 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
　また、リフレクタ３００の反射面は、ＬＥＤ１４の出射光の光軸に対して非対称な形状でもよい。この理由を、図１３Ａ（２）により説明する。本実施例では、リフレクタ３００の反射面は放物面であり、放物面の焦点位置に面光源であるＬＥＤの発光面の中心を配置する。 Furthermore, 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). In this embodiment, 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.
　また、放物面の特性上、発光面の４隅からの発光も略平行光束となり、出射方向が異なるだけである。そのため、発光部が面積を持っていても、後段に配置された偏光変換素子とリフレクタ３００の間隔が短ければ偏光変換素子２１へ入射する光量と変換効率は、ほとんど影響を受けない。 Further, due to the characteristics 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.
　また、ＬＥＤ１４の取り付け位置が、対応するリフレクタ３００の焦点に対してＸＹ平面内でずれても上述した理由により光変換効率の低下を軽減できる光学系が実現できる。更に、ＬＥＤ１４の取り付け位置がＺ軸方向にばらついた場合であっても、変換された平行光束がＺＸ平面内で移動するだけであり、面光源であるＬＥＤの取り付け精度を大幅に軽減できる。本実施例においても放物面の一部を子午的に切り欠いた反射面を有するリフレクタ３００について記載したが、放物面全面を反射面として切り欠いた一部分にＬＥＤを配置してもよい。 Moreover, even if the mounting position of the LED 14 is shifted in the XY plane with respect to the focal point of the corresponding reflector 300, 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. In this embodiment as well, 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.
　一方、本実施例では、図１３Ａ、図１３Ｂ（１）、図１３Ｃに示したように、ＬＥＤ１４からの発散光を放物面３２１で反射させ略平行な光に変換した後、後段の偏光変換素子２１の端面に入射させ、偏光変換素子２１により特定の偏波に揃えることを特徴的な構成としている。この特徴的な構成により、本実施例では、光の利用効率が前述した図３の例に対して１.８倍となり、高効率な光源が実現できる。 On the other hand, in this embodiment, as shown in FIGS. 13A, 13B (1), and 13C, after the diverging light from the LED 14 is reflected by the paraboloid 321 and converted into substantially parallel light, 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.
　なお、この時、ＬＥＤ１４からの発散光を放物面３２１で反射させた略平行な光は、全て均一というわけではない。よって、複数の傾きを持った反射面３０７により反射光の角度分布を調整することで液晶表示パネル１１に向けて、液晶表示パネル１１に対して垂直方向に入射可能としている。 Note that at this time, 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 .
　ここで、本図の例では、ＬＥＤからリフレクタに入る光(主光線)の向きと液晶表示パネルに入る光の向きが略平行になるように配置している。この配置は、設計上配置がしやすく、また、熱源を光源装置の下に配置する方が、空気が上に抜けるのでＬＥＤの温度上昇を低減できるので好適である。 In the example shown in this figure, 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.
　また、図１３Ｂ（１）に示したように、ＬＥＤ１４からの発散光の捕捉率を向上させるために、リフレクタ３００で捕捉できない光束をリフレクタ上部に配置した遮光板３０９に設けたサブリフレクタ３０８で反射させ、下部のサブリフレクタ３１０の斜面で反射させ後段の偏光変換素子２１の有効領域に入射させ光の利用効率を更に向上させる。すなわち、本実施例では、リフレクタ３００で反射した光の一部をサブリフレクタ３０８で反射し、サブリフレクタ３０８で反射された光をサブリフレクタ３１０で導光体３０６に向かう方向に反射させる。 In addition, as shown in FIG. 13B (1), in order to improve the capture rate of the diverging light from the LED 14, 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.
　偏光変換素子２１により特定の偏波に揃えた略平行光束を反射型導光体３０６の表面に設けた反射形状によって導光体３０６に対向して配置された液晶表示パネル１１に向けて反射される。この時、液晶表示パネル１１に入射する光束の光量分布は、前述したリフレクタ３００の形状と配置および反射型導光体の反射面形状（断面形状）と反射面の傾き、面粗さによって最適設計される。 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. At this time, 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.
　導光体３０６の表面に設けた反射面形状としては、偏光変換素子の出射面に対向して複数の反射面を配置し、偏光変換素子２１からの距離に応じて、反射面の傾き、面積、高さ、ピッチを最適化することで、前述したように、液晶表示パネル１１に入射する光束の光量分布を所望の値とする。 As for 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.
　反射型導光体に設けた反射面３０７は、図１３Ｂ（２）に示すように、１面に複数の傾きを持つような構成とすることで、より高精度に反射光の調整を実現できる。なお、反射面において、１面に複数の傾きを持つような構成としては、反射面として使用する領域が、複数面または多面または曲面でもよい。反射面３０７には、図１３Ｂ（２）に示したように、リフレクタ３００からの平行光束φ５（Ｒ７～Ｒ１０）はその進行方向において、傾きの異なる複数の面（Ｐ７～Ｐ１０）で反射され、それぞれに対応した液晶パネル部分に向かう。傾きの異なる複数の面のそれぞれの面はリフレクタ３００からの平行光束の進行方向に垂直な方向に延伸する形状を有してもよい。導光体３０６の光源光反射面３０７は、光源光が伝搬する光軸に対して垂直な方向に複数の反射面が配列された構成を成し、それぞれの反射面の傾斜角度により液晶表示パネル１１に入射する光源光の出射方向と拡散角を調整する。すなわち、導光体３０６の反射面３０７は、リフレクタ３００の反射面で反射された光の光軸に対して垂直な方向に複数の反射面が配列された構成であり、それぞれの反射面の傾斜角度により液晶表示パネル１１に入射する光の出射方向と拡散角を調整する。 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. . In addition, in the case of a configuration in which the reflective surface has a plurality of inclinations on one surface, the region used as the reflective surface may be a plurality of surfaces, a polysurface, or a curved surface. As shown in FIG. 13B (2), on the reflective surface 307, the parallel light beam φ5 (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. That is, 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.
　更に拡散板２０６の拡散作用により、より均一な光量分布を実現する。ＬＥＤに近い側の拡散板に入射する光は、反射面の傾きを変化させることで、均一な光量分布を実現する。この結果、液晶表示パネル１１に向かう光束の光量と出射方向を高精度に調整できる。この結果、液晶表示パネル１１への入射光および液晶表示パネル１１からの出射光の光量および出射方向も同様に高精度に制御できるため、この光源を用いた映像表示装置を用いた空間浮遊映像表示システムにおいては、空間浮遊映像の映像光の拡散方向と拡散角を所望の値に設定できる。 Furthermore, 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. As a result, 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. As a result, 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. In the system, the direction and angle of diffusion of the image light of the spatially floating image can be set to desired values.
　本実施例では、反射面３０７の基材は、耐熱性ポリカーボネートなどのプラスチック材料を用いてもよい。また、λ／２板２１３の出射直後の反射面３０７の角度は、λ／２板と反射面の距離によって変化する。 In this embodiment, 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 λ/2 plate 213 changes depending on the distance between the λ/2 plate and the reflecting surface.
　本実施例においても、ＬＥＤ１４とリフレクタ３００は、一部において近接されるが、リフレクタ３００の開口側の空間へ放熱できＬＥＤの温度上昇を低減できる。また、基板１０２とリフレクタ３００を図１３Ａ、図１３Ｂ、図１３Ｃと上下逆に配置してもよい。 In this embodiment as well, although 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. Further, the substrate 102 and the reflector 300 may be arranged upside down as shown in FIGS. 13A, 13B, and 13C.
　ただし、基板１０２を上に配置すると基板１０２が液晶表示パネル１１と近くなるので、レイアウトが困難になる場合がある。よって、図示した通り、基板１０２をリフレクタ３００の下側（液晶表示パネル１１から遠い側）に配置する方が、装置内の構成がより簡素になる。 However, 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.
　偏光変換素子２１の光入射面には、後段の光学系に不要な光が入射しないように、遮光板４１０を設けるとよい。このような構成とすることで、温度上昇を抑えた光源装置が実現できる。液晶表示パネル１１の光入射面に設けた偏光板では本願発明の偏光が揃った光束では吸収により温度上昇が低減させるが、反射型導光体で反射した際に偏光方向が回転し一部の光は入射側偏光板で吸収される。更に、液晶そのものでの吸収や電極パターンに入射した光による温度上昇で液晶表示パネル１１の温度も上昇するが、反射型導光体３０６の反射面と液晶表示パネル１１の間に十分な空間があり自然冷却が可能となる。 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. Furthermore, 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.
　図１３Ｄは、図１３Ｂ（１）および図１３Ｃの光源装置の変形例である。図１３Ｄ（１）は、図１３Ｂ（１）の光源装置の一部を抜粋してその変形例を図示している。その他の構成については、図１３Ｂ（１）で上述した光源装置と同じ構成であるため、図示および繰り返しの説明を省略する。 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.
　まず、図１３Ｄ（１）に示す例では、サブリフレクタ３１０の凹部３１９の高さは、蛍光体１１４から横向き（Ｘ軸方向）に出力される蛍光の主光線（図１３Ｄ（１）中、Ｘ軸と平行な方向に伸びる直線を参照）が、サブリフレクタ３１０の凹部３１９から抜けるように、蛍光体１１４よりも低い位置となるように調整されている。更に、蛍光体１１４から横向きに出力される蛍光の主光線が遮光板４１０により遮られずに偏光変換素子２１の有効領域に入射するように、蛍光体１１４の位置に対して、Ｚ軸方向において遮光板４１０の高さが低くなるように調整されている。 First, in the example shown in FIG. 13D (1), 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.
　また、サブリフレクタ３１０の頂部の凹凸の凸部が有する反射面は、サブリフレクタ３０８で反射した光を導光体３０６に導くために、サブリフレクタ３０８で反射した光を反射する。よって、サブリフレクタ３１０の凸部３１８の高さは、サブリフレクタ３０８で反射した光を反射させ後段の偏光変換素子２１の有効領域に入射するように調整されることで、光の利用効率を更に向上させることができる。 Further, 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.
　なお、サブリフレクタ３１０は図１３Ａ（２）に示すように一方方向に延伸して配置され、凹凸形状となっている。更に、サブリフレクタ３１０の頂部には、１つ以上の凹部３１９と凸部３１８を有する凹凸が周期的に一方向に沿って並んでいる。このような凹凸形状とすることにより、蛍光体１１４から横向きに出力される蛍光の主光線が偏光変換素子２１の有効領域に入射するように構成できる。 Note that, as shown in FIG. 13A(2), 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.
　また、サブリフレクタ３１０の凹凸形状は、ＬＥＤ１４がある位置に凹部３１９がくるピッチで周期的に配置されている。すなわち、蛍光体１１４のそれぞれは、サブリフレクタ３１０の凹凸の凹部の配置のピッチに対応して一方向に沿って周期的に配置される。なお、蛍光体１１４がＬＥＤ１４に備えられている場合は、蛍光体１１４を光源の発光部と表現してもよい。 Further, 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.
　また、図１３Ｄ（２）は、図１３Ｃの光源装置の一部を抜粋してその変形例を図示している。その他の構成については、図１３Ｃの光源装置と同じ構成であるため、図示および繰り返しの説明を省略する。図１３Ｄ（２）に示すように、サブリフレクタ３１０はなくてもよいが、図１３Ｄ（１）と同様に、蛍光体１１４から横向きに出力される蛍光の主光線が遮光体４１０により遮られずに偏光変換素子２１の有効領域に入射するように、蛍光体１１４の位置に対して、Ｚ軸方向において遮光板４１０の高さが低くなるように調整されている。 Further, 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. As shown in FIG. 13D (2), 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.
　なお、図１３Ａ、図１３Ｂ、図１３Ｃ、図１３Ｄの光源装置について、図１３Ａ（１）に示したように、反射型導光体３０６の反射面と液晶表示パネル１１の間の空間へのごみ入り込み防止、光源装置外部への迷光発生防止、および光源装置外部からの迷光侵入防止のために、側壁４００を設けてもよい。側壁４００を設ける場合は、導光体３０６と拡散板２０６との空間を挟むように配置される。 Regarding the light source devices in FIGS. 13A, 13B, 13C, and 13D, as shown in FIG. 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. When the side wall 400 is provided, it is arranged so as to sandwich the space between the light guide 306 and the diffusion plate 206.
　当該偏光変換素子２１によって偏光変換された光を出射する偏光変換素子２１の光出射面は、側壁４００と導光体３０６と拡散板２０６と偏光変換素子２１とで囲まれた空間に面する。また、側壁４００の内側の面のうち、偏光変換素子２１の出射面から光が出力される空間（図１３Ｂ（１）の偏光変換素子２１の出射面から右側の空間）を側面から覆う部分の面は、反射膜などを有する反射面を用いる。すなわち、上記空間に面する側壁４００の面は、反射膜を有する反射領域を備える。側壁４００の内側の面のうち当該部分を反射面とすることで、当該反射面で反射した光を光源光として再利用でき、光源装置の輝度を向上することができる。 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. By making the part of the inner surface of the side wall 400 a reflective surface, the light reflected by the reflective surface can be reused as light source light, and the brightness of the light source device can be improved.
　側壁４００の内側の面のうち、偏光変換素子２１を側面から覆う部分の面は、光反射率の低い面（反射膜のない黒色面など）とする。これは、偏光変換素子２１の側面で反射光が生じると、想定外の偏光状態の光が生じ、迷光の原因となるためである。言い換えると、上記の面を光反射率の低い面とすることにより、映像の迷光および想定外の偏光状態の光の発生を防止ないし抑制することができる。また、側壁４００の一部に空気が通る穴を開けておくことで冷却効果を向上させるように構成してもよい。 Of the inner surfaces of the side wall 400, 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. In other words, by making the above-mentioned surface a surface with low light reflectance, it is possible to prevent or suppress the generation of stray light in the image and light with an unexpected polarization state. Alternatively, the cooling effect may be improved by opening a hole in a part of the side wall 400 for air to pass through.
　なお、図１３Ａ、図１３Ｂ、図１３Ｃ、図１３Ｄの光源装置は、偏光変換素子２１を用いる構成を前提として説明した。しかしながら、これらの光源装置から偏光変換素子２１を省略して構成してもよい。この場合、より安価に光源装置を提供することができる。 Note that 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.
　＜光源装置の例３＞
　続いて、光源装置の例１に示した光源装置を基に反射型導光体３０４を用いた光源装置に関する光学系の構成について、図１４Ａ（１）、（２）、（３)、および図１４Ｂを参照しながら詳細に説明する。 <Example 3 of light source device>
Next, 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.
　図１４Ａは、光源を構成するＬＥＤ１４が基板１０２に備え付けられた状態を示しており、これらはコリメータ１８とＬＥＤ１４が一対のブロックとし、複数のブロックを有するユニット３２８で構成する。本実施例のコリメータ１８は、ＬＥＤ１４と近接しているため、耐熱性を考慮してガラス材料を採用している。コリメータ１８の形状は、図１６のコリメータ１５で説明した形状と同様である。また、偏光変換素子２１へ入射する前段に遮光板３１７を設けることにより、不要な光が後段の光学系に入射するのを防止ないし抑制し、当該不要な光による温度の上昇を軽減している。 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. .
　図１３Ａに示す光源のその他の構成および効果については、図１３Ａ、図１３Ｂ、図１３Ｃ、図１３Ｄと同様であるため、繰り返しの説明を省略する。図１３Ａの光源装置は、図１３Ａ、図１３Ｂ、図１３Ｃで説明したのと同様に、側壁を設けてもよい。側壁の構成および効果については、既に説明した通りであることから、繰り返しの説明を省略する。 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.
　図１４Ｂは、図１４Ａ（２）の断面図である。図１４Ｂに示す光源の構成については、図１７の光源の構造の一部と共通であり、図１７において既に説明済みであるため、繰り返しの説明を省略する。 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.
　＜光源装置の例４＞
　続いて、図４の光源装置は、図１４Ａ、図１４Ｂに示した光源装置に用いたコリメータ１８とＬＥＤ１４が一対のブロックとして複数のブロックを有するユニットで構成する。液晶表示パネル１１の背面の両端部に配置したＬＥＤと反射型導光体５０４を用いた光源装置に関する光学系の構成について、図４（ａ）（ｂ）（ｃ）を参照しながら詳細に説明する。 <Example 4 of light source device>
Subsequently, 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.
　図４は光源を構成するＬＥＤ１４が基板５０５に備え付けられた状態を示しており、これらはコリメータ１８とＬＥＤ１４が一対のブロックとした複数のブロックを有するユニット５０３で構成する。ユニット５０３は液晶表示パネル１１の背面の両端部に配置される（本実施例では短辺方向に３ユニットが並んで配置される）。ユニット５０３から出力された光は反射型導光体５０４で反射され、対向配置された液晶表示パネル１１（図示せず）に入射する構成としている。 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.
　反射型導光体５０４は、それぞれの端部に配置されたユニットに対応して２つのブロックに分割され中央部が最も高くなるように配置されている。コリメータ１８は、ＬＥＤ１４と近接しているため、ＬＥＤ１４から発せられる熱への耐熱性を考慮して、ガラス材料を採用している。コリメータ１８の形状は、図１４Ａ（３）のコリメータ１８で説明した形状である。 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).
　ＬＥＤ１４からの光はコリメータ１８を介して偏光変換素子５０１へ入射する。光学素子８１の形状により後段の反射型導光体５０４に入射する光の分布を調整する構成としている。すなわち、液晶表示パネル１１に入射する光束の光量分布は、前述したコリメータ１８の形状と、配置および光学素子８１の形状と、拡散特性および反射型導光体の反射面形状（断面形状）と、反射面の傾き、反射面の面粗さと、を調整することによって最適設計される。 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.
　反射型導光体５０４の表面に設けた反射面形状としては、図４（b）に示すように、偏光変換素子の出射面に対向して複数の反射面を配置し、偏光変換素子２１からの距離に応じて、反射面の傾き、面積、高さ、ピッチを最適化する。また、同一反射面となる領域（すなわち、偏光変換素子に対向する面）を多面体に分割することで、前述したように液晶表示パネル１１に入射する光束の光量分布を所望の値とする（最適化する）ことができる。このため、液晶表示パネル１１に向かう光束の光量と出射方向を高精度に調整できる。この結果、液晶表示パネル１１への入射光および液晶表示パネル１１からの出射光の光量および出射方向も同様に高精度に制御できるため、この光源を用いた映像表示装置を用いた空間浮遊映像表示システムにおいては、空間浮遊映像の映像光の拡散方向と拡散角を所望の値に設定できる（図１３Ｂ（２）中の導光体に入射する４本の実線矢印を参照）。 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. In addition, by dividing the area serving as the same reflective surface (that is, the surface facing the polarization conversion element) into polyhedrons, 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. As a result, 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. In the system, 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)).
　反射型導光体に設けた反射面は、図１３Ｂで説明した反射型導光体３０６と同様に、１面（光の反射させる領域）を、複数の傾きを持った形状を持たせる構成（図４の例ではＸＹ平面内で１４分割して異なった傾斜面で構成）とすることで、より高精度に反射光の調整を行うことができる。また、反射型導光体からの反射光が光源装置１３の側面から漏れないようにするため、遮光壁５０７を設けることにより、所望の方向（液晶表示パネル１１へ向かう方向）以外への漏れ光の発生を防止することができる。 Similar to the reflective light guide 306 described in FIG. 13B, 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. In addition, in order to prevent the reflected light from the reflective light guide from leaking from the side surface of the light source device 13, 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.
　また、図４の反射型導光体５０４の左右に配置されるユニット５０３を、図１３Ａの光源装置に置き換えてもよい。すなわち、図１３Ａの光源装置（基板１０２、リフレクタ３００、ＬＥＤ１４等）を複数用意し、かかる複数の光源装置を、図４（ａ）、（ｂ）、（ｃ）に参照されるように、互いに対向する位置に配置した構成としてもよい。 Furthermore, 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.
　図１８（Ｂ）は、図１８（Ａ）に示したユニット５０３を、上部に６個、下部に６個配置して構成した光源装置である。図１８（Ｂ）に示す光源装置は、５個のＬＥＤを横に並べたユニット５０３を上記のように配置した構成であり、単一電源で電流制御して所望の輝度を得る。このため、液晶パネルを照明する光源装置としては、それぞれのユニット５０３が照射する領域ごとに光源輝度を制御することができる。 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.
　図１８に示す構成では、反射面２２２と、かかる反射面２２２とは異なる反射面５０２と、を備える。このうち、反射面２２２は、横格子のような形状、あるいは所定の幅を有する帯状である。一方、反射面５０２は、縦横の格子のような形状である。これらの微細な格子の形状および分割面の傾きを最適設計することで、所望の出射光分布（出射光の出射方向と拡散特性）を得る。 The configuration shown in FIG. 18 includes a reflective surface 222 and a reflective surface 502 different from the reflective surface 222. Of these, the reflective surface 222 has a horizontal lattice-like shape or a band shape with a predetermined width. On the other hand, the reflective surface 502 has a shape like a vertical and horizontal lattice. By optimally designing the shape of these fine gratings and the inclination of the dividing plane, a desired output light distribution (the output direction and diffusion characteristics of the output light) is obtained.
　この結果、上述した２つの実施例と同様に、液晶表示パネル１１への入射光および液晶表示パネル１１からの出射光の光量および出射方向を同様に高精度に制御できるため、この光源を用いた映像表示装置を用いた空間浮遊映像表示システムにおいては、空間浮遊映像の映像光の拡散方向と拡散角を所望の値に設定できる。 As a result, similarly to the two embodiments described above, 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. In a spatially floating video display system using a video display device, the diffusion direction and diffusion angle of image light of a spatially floating video can be set to desired values.
　＜拡散板の構造＞
　図１５は、拡散板２０６の形状の一例を示す断面図である。上述のように、ＬＥＤから出力された発散光は、リフレクタ３００またはコリメータ１８で略平行光に変換され、偏光変換素子２１で特定偏波に変換された後に、導光体で反射させられる。そして、導光体で反射した光束は、拡散板２０６の入射面の平面部分を通過して、液晶表示パネル１１に入射する（図１５中の「導光体からの反射光」を示す２本の実線矢印を参照）。 <Structure of the diffuser plate>
FIG. 15 is a cross-sectional view showing an example of the shape of the diffusion plate 206. As described above, 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).
　また、偏光変換素子２１から出射した光のうち、発散光束は、拡散板２０６の入射面に設けた傾斜面を有する突起部の斜面で全反射して、液晶表示パネル１１に入射する。偏光変換素子２１から出射した光を拡散板２０６の突起部の斜面で全反射させるために、突起部の斜面の角度を、偏光変換素子２１からの距離に基づいて変化させる。偏光変換素子２１から遠い側またはＬＥＤから遠い側の突起部の斜面の角度をαとし、偏光変換素子２１から近い側またはＬＥＤから近い側の突起部の斜面の角度をα’とする場合、αはα’より小さい（α＜α’）。このような設定とすることにより、偏光変換された光束を有効利用することが可能となる。 Further, among the light emitted from the polarization conversion element 21 , 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 . In order to cause the light emitted from the polarization conversion element 21 to be totally reflected on the slope of the projection of the diffuser plate 206, the angle of the slope of the projection is changed based on the distance from the polarization conversion element 21. When the angle of the slope of the protrusion on the side far from the polarization conversion element 21 or the side far from the LED is α, and the angle of the slope of the protrusion on the side close to the polarization conversion element 21 or the side close to the LED is α', α is smaller than α' (α<α'). With such a setting, it becomes possible to effectively utilize the polarized light flux.
　＜映像表示装置の拡散特性制御技術＞
　液晶表示パネル１１からの映像光の拡散分布を調整する方法として、光源装置１３と液晶表示パネル１１との間、あるいは、液晶表示パネル１１の表面に、レンチキュラーレンズを設け、当該レンズの形状を最適化することが挙げられる。すなわち、レンチキュラーレンズ形状の最適化を行うことによって、液晶表示パネル１１から一方向に出射される映像光（以下、「映像光束」とも称する）の出射特性を調整することができる。 <Diffusion characteristic control technology for video display devices>
As a method of adjusting the diffusion distribution of image light from the liquid crystal display panel 11, 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.
　代替的または追加的に、液晶表示パネル１１の表面（または光源装置１３と液晶表示パネル１１との間）に、マイクロレンズアレイをマトリックス状に配置し、当該配置の態様を調整してもよい。すなわち、マイクロレンズアレイの配置を調整することによって、映像表示装置１から出射される映像光束についての、Ｘ軸およびＹ軸方向への出射特性を調整することができ、この結果、所望の拡散特性を有する映像表示装置を得ることができる。 Alternatively or additionally, 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.
　更なる構成例として、映像表示装置１から出射される映像光が通過する位置に、２枚のレンチキュラーレンズを組み合わせて配置する、または、マイクロレンズアレイをマトリックス状に配置して拡散特性を調整するシートを設けてもよい。このような光学系の構成とすることにより、Ｘ軸およびＹ軸方向において、映像光の輝度（相対輝度）を、映像光の反射角度（垂直方向に反射した場合を基準（０度）とした反射角度）に応じて調整することができる。 As a further configuration example, 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. By configuring the optical system like this, the brightness (relative brightness) of the image light in the X-axis and Y-axis directions can be adjusted to the reflection angle of the image light (with the case of reflection in the vertical direction as the standard (0 degrees)). reflection angle).
　本実施例では、このようなレンチキュラーレンズを使用することにより、図２０（Ｂ）中に「例１（Ｙ方向）」および「例２（Ｙ方向）」のグラフ（プロット曲線）に示すように、従来特性のグラフ（プロット曲線）とは明らかに異なった、優れた光学的特性を獲得することができる。具体的には、例１（Ｙ方向）および例２（Ｙ方向）のプロット曲線では、垂直方向の輝度特性を急峻にし、更に、上下方向（Ｙ軸の正負方向）の指向特性のバランスを変化させることで、反射や拡散による光の輝度（相対輝度）を高めることができる。 In this example, by using such a lenticular lens, as shown in the graphs (plot curves) of "Example 1 (Y direction)" and "Example 2 (Y direction)" in FIG. , it is possible to obtain excellent optical characteristics that are clearly different from conventional characteristic graphs (plot curves). Specifically, in the plot curves of Example 1 (Y direction) and Example 2 (Y direction), the brightness characteristics in the vertical direction are made steeper, and the balance of the directional characteristics in the vertical direction (positive and negative directions of the Y axis) is further changed. By doing so, the brightness (relative brightness) of light due to reflection and diffusion can be increased.
　このため、本実施例によれば、面発光レーザ映像源からの映像光のように、拡散角度が狭く（高い直進性）かつ特定の偏波成分のみの映像光とし、従来技術による映像表示装置を用いた場合に再帰反射部材で発生していたゴースト像を抑え、再帰反射による空間浮遊像を効率良く観視者の眼に届けるように、調整することができる。 Therefore, according to this embodiment, 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.
　また、上述した光源装置により、図２０の（Ａ）、（Ｂ）に示した一般的な液晶表示パネルからの出射光拡散特性（図中では「従来特性」と表記）に対して、Ｘ軸方向およびＹ軸方向ともに大幅に挟角な指向特性を持たせることができる。本実施例では、このような狭角な指向特性を持たせることで、特定方向に向けて平行に近い映像光束を出射する、特定偏波の光を出射する映像表示装置を実現することができる。 In addition, 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. .
　図１９には、本実施例で採用するレンチキュラーレンズの特性の一例を示している。この例では、特に、Ｚ軸を基準としたＸ方向（垂直方向）における特性を示しており、特性Ｏは、光の出射方向のピークが垂直方向（０度）から上方に３０度付近の角度であり上下に対称な輝度特性を示している。また、図１９のグラフに示す特性Ａや特性Ｂのプロット曲線は、更に、３０度付近においてピーク輝度の上方の映像光を集光して輝度（相対輝度）を高めた特性の例を示している。このため、これらの特性Ａや特性Ｂでは、特性Ｏのプロット曲線と比較して分かるように、Ｚ軸からＸ方向への傾き（角度θ）が３０度を超えた角度（θ＞３０°）の領域において、急激に光の輝度（相対輝度）が低減する。 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. Furthermore, 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. Therefore, in these characteristics A and B, as can be seen by comparing with the plot curve of characteristic O, the angle where the inclination (angle θ) from the Z axis to the X direction exceeds 30 degrees (θ > 30 degrees) In the region, the brightness (relative brightness) of light decreases rapidly.
　すなわち、上述したレンチキュラーレンズを含んだ光学系によれば、映像表示装置１からの映像光束を再帰反射部材に入射させる際、光源装置１３で挟角に揃えられた映像光の出射角度や視野角を調整でき、再帰反射シートの設置の自由度を大幅に向上できる。その結果、ウィンドガラスを反射または透過して所望の位置に結像する空間浮遊像の結像位置の関係の自由度を大幅に向上できる。この結果、拡散角度が狭く（高い直進性）かつ特定の偏波成分のみの光として効率良く室外または室内の観視者の眼に届くようにすることが可能となる。このことによれば、映像表示装置１からの映像光の強度（輝度）が低減しても、観視者は映像光を正確に認識して情報を得ることができる。換言すれば、映像表示装置１の出力を小さくすることにより、消費電力の低い表示システムを実現することが可能となる。 That is, according to 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. According to this, even if the intensity (luminance) of the image light from the image display device 1 is reduced, the viewer can accurately recognize the image light and obtain information. In other words, by reducing the output of the video display device 1, it is possible to realize a display system with low power consumption.
　以上、本発明を適用した種々の実施の形態ないし実施例（すなわち具体例）について詳述した。一方で、本発明は、上述した実施形態（具体例）のみに限定されるものではなく、様々な変形例が含まれる。例えば、上記した実施形態は、本発明を分かりやすく説明するためにシステム全体を詳細に説明したものであり、必ずしも説明した全ての構成を備えるものに限定されるものではない。また、ある実施形態の構成の一部を他の実施形態の構成に置き換えることが可能であり、また、ある実施形態の構成に他の実施形態の構成を加えることも可能である。また、各実施形態の構成の一部について、他の構成の追加・削除・置換をすることが可能である。 Various embodiments and examples (ie, specific examples) to which the present invention is applied have been described above in detail. On the other hand, the present invention is not limited to the embodiment (specific example) described above, and includes various modifications. For example, in the embodiments described above, 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. Furthermore, it is possible to replace a part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. Furthermore, it is possible to add, delete, or replace some of the configurations of each embodiment with other configurations.
　上記で説明した光源装置は、空間浮遊映像表示装置に限られず、ＨＵＤ、タブレット、デジタルサイネージ等のような表示装置に適用することも可能である。 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.
　本実施の形態に係る技術では、空間浮遊映像を高解像度かつ高輝度な映像を空間浮遊した状態で表示することにより、例えば、ユーザは感染症の接触感染に対する不安を感じることなく操作することを可能にする。不特定多数のユーザが使用するシステムに本実施例に係る技術を用いれば、感染症の接触感染のリスクを低減し、不安を感じることなく使用できる非接触ユーザインタフェースを提供することを可能にする。このような技術を提供する本発明によれば、国連の提唱する持続可能な開発目標（ＳＤＧｓ:Sustainable Development Goals）の「３全ての人に健康と福祉を」に貢献する。 In the technology according to the present embodiment, by displaying a high-resolution and high-brightness video floating in space, 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.
　また、上述した実施の形態に係る技術では、出射する映像光の発散角を小さくし、更に特定の偏波に揃えることで、再帰反射部材に対して正規の反射光だけを効率良く反射させるため、光の利用効率が高く、明るく鮮明な空間浮遊映像を得ることが可能になる。本実施の形態に係る技術によれば、消費電力を大幅に低減することが可能な、利用性に優れた非接触ユーザインタフェースを提供することができる。このような技術を提供する本発明によれば、国連の提唱する持続可能な開発目標（ＳＤＧｓ:Sustainable Development Goals）の「９産業と技術革新の基盤をつくろう」および「１１住み続けられるまちづくりを」に貢献する。 Further, in the technology according to the embodiment described above, by reducing the divergence angle of the emitted image light and aligning it with a specific polarization, only the regular reflected light can be efficiently reflected by the retroreflective member. , it is possible to obtain bright and clear spatial floating images with high light utilization efficiency. According to the technology according to the present embodiment, it is possible to provide a contactless user interface with excellent usability and which can significantly reduce power consumption. According to the present invention, which provides such technology, it is possible to meet the Sustainable Development Goals (SDGs) advocated by the United Nations, including ``Building a foundation for 9 industries and technological innovation'' and ``11 Creating sustainable cities.'' Contribute to
　更に、上述した実施の形態に係る技術では、指向性（直進性）の高い映像光による空間浮遊映像を形成することを可能にする。本実施例５に係る技術では、銀行のＡＴＭや駅の券売機等における高いセキュリティが求められる映像や、ユーザに正対する人物には秘匿したい秘匿性の高い映像を表示する場合でも、指向性の高い映像光を表示することで、ユーザ以外に空間浮遊映像を覗き込まれる危険性が少ない非接触ユーザインタフェースを提供することを可能にする。本発明は、以上のような技術を提供することにより、国連の提唱する持続可能な開発目標（ＳＤＧｓ:Sustainable Development Goals）の「１１住み続けられるまちづくりを」に貢献する。 Furthermore, the technology according to the embodiment described above makes it possible to form a spatially floating image using highly directional (straight-progressing) image light. With 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. By providing the above-mentioned technology, the present invention contributes to the Sustainable Development Goals (SDGs: Sustainable Development Goals 11) advocated by the United Nations.
１…映像表示装置、２…第一の再帰反射部材、５…第二の再帰反射部材、３…空間像（空間浮遊像）、１００…透過性プレート、１３…光源装置、５４…光方向変換パネル、１０５…リニアフレネルシート、１０１…吸収型偏光シート(吸収型偏光板)、２００…平面ディスプレイ、２０１…筐体、２０３…センシングシステム、２２６…センシングエリア、１０２…基板、１１、３３５…液晶表示パネル、２０６…拡散板、２１…偏光変換素子、３００…リフレクタ、２１３…λ／２板、３０６…反射型導光体、３０７…反射面、３０８、３１０…サブリフレクタ、２０４…空間浮遊映像、３３４…映像光制御シート、３３６…透過部、３３７…光吸収部、８１…光学素子、５０１…偏光変換素子、５０３…ユニット、５０７…遮光壁、４０１、４０２…遮光板、３２０…基材、５１１…筐体、５１２…サポートアーム、５１３…ヒンジ、５１４…バックカバー、５１５…筐体カバー、５１６…筐体ベース。 DESCRIPTION OF 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... λ/2 plate, 306... Reflective light guide, 307... Reflective surface, 308, 310... Sub-reflector, 204... Space floating image , 334... Image light control sheet, 336... Transmissive section, 337... Light absorbing section, 81... Optical element, 501... Polarization conversion element, 503... Unit, 507... Light blocking wall, 401, 402... Light blocking plate, 320... Base material , 511... Housing, 512... Support arm, 513... Hinge, 514... Back cover, 515... Housing cover, 516... Housing base.

Claims (13)

  1. 　空間浮遊映像表示システムであって、
    　映像を表示する表示パネルと、
    　　前記表示パネルに光を供給する光源装置と、
    　前記表示パネルからの映像光を反射させ、反射した光により空中に実像の空間浮遊映像を表示せしめる再帰反射部材と、
    　を備え、
    　前記再帰反射部材は位相差板を含み、前記位相差板は逆波長分散を有し、前記再帰反射部材の映像光入射面側に配置される、
    　空間浮遊映像表示システム。     A spatial floating image display system,
    a display panel that displays images;
    a light source device that supplies light to the display panel;
    a retroreflective member that reflects image light from the display panel and displays a real spatially floating image in the air using the reflected light;
    Equipped with
    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.
    Space floating video display system.
  2. 　請求項１に記載の空間浮遊映像表示システムにおいて、
    　前記再帰反射部材は、反射層と透過性基材と反射面とを含む、
    　空間浮遊映像表示システム。     The spatial floating image display system according to claim 1,
    The retroreflective member includes a reflective layer, a transparent base material, and a reflective surface.
    Space floating video display system.
  3. 　請求項２に記載の空間浮遊映像表示システムにおいて、
    　前記再帰反射部材は、前記再帰反射部材の映像光入射面側から順に、前記位相差板、前記透過性基材、前記反射層、前記透過性基材、前記反射面がある、
    　空間浮遊映像表示システム。     The spatial floating image display system according to claim 2,
    The retroreflective member includes, in order from the image light incident surface side of the retroreflective member, the retardation plate, the transparent base material, the reflective layer, the transparent base material, and the reflective surface.
    Space floating video display system.
  4. 　請求項１に記載の空間浮遊映像表示システムにおいて、
    　前記位相差板はポリカーボネート材料を用いる、
    　空間浮遊映像表示システム。     The spatial floating image display system according to claim 1,
    The retardation plate is made of polycarbonate material.
    Space floating video display system.
  5. 　請求項２に記載の空間浮遊映像表示システムにおいて、
    　前記表示パネルの映像光出射側に配置される映像光制御シートを備え、
    　前記映像光制御シートは、前記表示パネルから出射する映像光束の出射方向と発散角を調整する、
    　空間浮遊映像表示システム。     The spatial floating image display system according to claim 2,
    an image light control sheet disposed on the image light output side of the display panel,
    The image light control sheet adjusts the emission direction and divergence angle of the image light flux emitted from the display panel.
    Space floating video display system.
  6. 　請求項１に記載の空間浮遊映像表示システムにおいて、
    　前記映像光制御シートは、前記表示パネルの視野角制御フィルムである、
    　空間浮遊映像表示システム。     The spatial floating image display system according to claim 1,
    The image light control sheet is a viewing angle control film of the display panel,
    Space floating video display system.
  7. 　請求項１に記載の空間浮遊映像表示システムにおいて、
    　前記空間浮遊映像から拡散される映像光束の拡散角と拡散方向は、前記映像光制御シートと光源装置の拡散特性により調整される、
    　空間浮遊映像表示システム。     The spatial floating image display system according to claim 1,
    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 and the light source device.
    Space floating video display system.
  8. 　請求項１に記載の空間浮遊映像表示システムにおいて、
    　前記光源装置は、
    　点状または面状の光源と、
    　前記光源からの光を反射させるリフレクタと、
    　前記リフレクタからの光を前記表示パネルに向けて導光する導光体と、を備え、
    　前記リフレクタの反射面は、前記光源の出射光の光軸に対して非対称な形状である、
    　空間浮遊映像表示システム。     The spatial floating image display system according to claim 1,
    The light source device includes:
    A point or planar light source,
    a reflector that reflects light from the light source;
    a light guide that guides light from the reflector toward the display panel;
    The reflective surface of the reflector has an asymmetric shape with respect to the optical axis of the light emitted from the light source.
    Space floating video display system.
  9. 　請求項８に記載の空間浮遊映像表示システムにおいて、
    　前記導光体は、透過型導光体である、
    　空間浮遊映像表示システム。     The spatial floating image display system according to claim 8,
    The light guide is a transmission type light guide.
    Space floating video display system.
  10. 　請求項８に記載の空間浮遊映像表示システムにおいて、
    　前記導光体は、反射型導光体である、
    　空間浮遊映像表示システム。     The spatial floating image display system according to claim 8,
    The light guide is a reflective light guide.
    Space floating video display system.
  11. 　請求項８に記載の空間浮遊映像表示システムにおいて、
    　前記導光体からの光を拡散する拡散板と、
    　前記導光体と前記拡散板との空間を挟むように配置される側壁と、を備える、
    　空間浮遊映像表示システム。     The spatial floating image display system according to claim 8,
    a diffusion plate that diffuses the light from the light guide;
    comprising a side wall arranged to sandwich a space between the light guide and the diffuser plate;
    Space floating video display system.
  12. 　請求項８に記載の空間浮遊映像表示システムにおいて、
    　前記リフレクタは、プラスチック材料またはガラス材料または金属材料を用いる、
    　空間浮遊映像表示システム。     The spatial floating image display system according to claim 8,
    The reflector is made of plastic material, glass material or metal material,
    Space floating video display system.
  13. 　請求項８に記載の空間浮遊映像表示システムにおいて、
    　前記導光体の光源光反射面は、光源光が伝搬する光軸に対して垂直な方向に複数の反射面が配列された構成を成し、それぞれの前記反射面の傾斜角度により前記表示パネルに入射する光源光の出射方向と拡散角を調整する、
    　空間浮遊映像表示システム。     The spatial floating image display system according to claim 8,
    The light source light reflecting surface of the light guide 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 display panel to Adjust the emission direction and diffusion angle of the light source light incident on the
    Space floating video display system.
PCT/JP2023/021189 2022-07-01 2023-06-07 Spatial floating video display system WO2024004557A1 (en)

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