JP4928152B2 - Rear projection display device and screen - Google Patents

Description

  The present invention relates to a rear projection display device and a screen used therefor, and more particularly to a rear projection display device capable of dual view and 3D display and a screen used therefor.

  Conventionally, as a dual view display, for example, there are those disclosed in Patent Documents 1 and 2.

Patent Document 1 describes a liquid crystal display device having first and second pixels with asymmetric viewing angle characteristics. Patent Document 2 describes that a first pixel and a second pixel are provided, and a parallax barrier is provided so that either the first pixel or the second pixel can be seen in front of the first pixel and the second pixel (FIG. 5A). (2) etc.).
Japanese Patent Laying-Open No. 2005-078076 Japanese Patent Laying-Open No. 2005-078080

  However, the conventional dual view display has problems that it is difficult to increase the size of the liquid crystal display element, and that the alignment between the liquid crystal display element and the parallax barrier is not easy.

  An object of the present invention is to realize a dual view display or the like in a rear projection display device.

  The rear projection display device of the present invention includes a light source, image light generating means for outputting light emitted from the light source as first image light and second image light having different polarization directions, and the first Light projection means for projecting the first and second image light, and a screen for deflecting and emitting the first and second image light projected from the light projection means in different directions. It is a feature.

  In the rear projection display device of the present invention, the screen includes a first lens plate that emits the first and second image lights projected from the light projecting unit in a direction perpendicular to the plate surface. A second lens plate that inclines the first and second image lights emitted from the first lens plate by a certain angle from the vertical direction, and the first and second image lights emitted from the second lens plate. It is preferable to include a polarizing beam splitter plate that emits the two image lights in different directions.

  The screen of the present invention emits incident first image light and second image light having different polarization directions from each other in different directions.

  In the screen of the present invention, the first lens plate that emits the incident first and second image lights in a direction perpendicular to the plate surface, and the first lens plate that is emitted from the first lens plate. And a second lens plate that inclines the second image light at a certain angle from the vertical direction, and a polarization beam splitter that emits the first and second image light emitted from the second lens plate in different directions, respectively. And a plate.

  ADVANTAGE OF THE INVENTION According to this invention, a dual view display and a 3D display are realizable with a simple structure in a rear projection type display apparatus.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[First Embodiment]
FIG. 1 is a conceptual diagram for explaining a rear projection type display apparatus according to a first embodiment of the present invention. FIG. 1 is a view of a rear projection display device as viewed from above.

  In FIG. 1, the light emitted from the light source 10 is split by the polarization beam splitter 11 into S-polarized light and P-polarized light. The S-polarized light incident on the reflective liquid crystal element 12 controls the amount of retardation according to the video signal input to the reflective liquid crystal element 12 to increase the P-polarized component to become the first image light. The light passes through the polarization beam splitter 11 and enters the projection lens 14. The P-polarized light incident on the reflective liquid crystal element 13 controls the amount of retardation in accordance with the video signal input to the reflective liquid crystal element 13 to increase the S-polarized component to become the second image light. The image light is reflected in the polarization beam splitter 11 and enters the projection lens 14. The first and second image lights that have passed through the projection lens 14 are projected onto the screen 15. The light source 10, the polarization beam splitter 11, and the reflective liquid crystal elements 12 and 13 serve as image light generation means.

  The screen 15 includes a Fresnel lens 15-1, a prism plate 15-2, and a polarization beam splitter plate 15-3. The Fresnel lens 15-1 converts the first and second image light projected by the projection lens 14 into parallel light and emits the light in a direction perpendicular to the plate surface. The prism plate 15-2 changes the spectral path of the first and second image light from the Fresnel lens 15-1 by a certain angle (for example, 45 degrees). The polarization beam splitter plate 15-3 transmits the P-polarized first image light and reflects the S-polarized second image light among the first and second image lights from the prism plate 15-2. The first image light is image light formed by the reflective liquid crystal element 12, and the second image light is image light formed by the reflective liquid crystal element 13. In this way, as shown in FIG. 1, image lights having different images are emitted to the upper left side and the lower left side, respectively, thereby enabling a dual view.

  FIG. 2 is an explanatory diagram showing the optical paths of the first and second image lights that pass through the screen 15. In FIG. 2, the first and second image lights are incident from the left side by the projection lens 14. Then, through the Fresnel lens 15-1, the prism plate 15-2, and the polarization beam splitter plate 15-3, the S-polarized second image light is emitted on the upper right side and the P-polarized first image light is emitted on the lower right side. Is shown as being. FIG. 3 is a perspective view of the polarizing beam splitter plate 15-3.

[Second Embodiment]
FIG. 4 is a conceptual diagram for explaining a rear projection type display apparatus according to the second embodiment of the present invention. FIG. 4 is a view of the rear projection type display device as viewed from above. FIG. 5 is an explanatory diagram showing the optical paths of the first and second image lights that pass through the screen 15.

  In the first embodiment, the polarization separation film of the polarization beam splitter plate 15-3 that separates P-polarized light and S-polarized light is exposed on the surface, but in this embodiment, the polarization beam splitter plate 15 in which the polarization separation film is embedded. -4 is used. Such a polarizing beam splitter plate 15-4 can be manufactured by providing a polarizing separation film on the side surface of a prism and bonding a plurality of prisms together.

[Third Embodiment]
In the first and second embodiments described above, the case of monochromatic image display has been described. In this embodiment, the light source 10, the polarization beam splitter 11, the reflective liquid crystal elements 12, 13 and the projection lens 14 shown in FIGS. 1 and 2 are changed to the projection optical system shown in FIG. Made possible.

  FIG. 6 is a view showing a projection optical system for color display used in a rear projection type display device. 20 is a white light source, 21 is a dichroic mirror that reflects cyan, 22 is a mirror that reflects red, and 23 is a dichroic mirror that reflects green. Further, 24-1 and 24-2 are reflection type liquid crystal elements for forming first and second image light of green, and 25 is a polarization beam splitter. Reference numerals 26-1 and 26-2 denote reflective liquid crystal elements for forming blue first and second image lights, 27 denotes a polarization beam splitter, and 28-1 and 28-2 denote first and second red light beams. Reference numeral 29 denotes a reflection type liquid crystal element for forming image light 2, and a polarization beam splitter. Reference numeral 30 denotes a dichroic prism, which transmits the first and second image light of green, reflects the first and second image light of blue and red, and is projected by the projection lens 31 in FIGS. Is projected onto the screen 15.

  In addition, for color display, a method of putting an RBG color filter on each pixel of the liquid crystal display element, a method of switching RGB for each field using a color wheel, and an RBG LED, There is a method of switching and displaying RGB for each field.

[Fourth Embodiment]
FIG. 7 is a conceptual diagram for explaining a rear projection type display apparatus according to the fourth embodiment of the present invention. In this embodiment, the Fresnel lens 15-1 is separated from the prism plate 15-2 and the polarization beam splitter plate 15-3 as a reflecting mirror instead of a transmission type. In other words, the first and second image lights projected from the projection lens 14 are reflected by the Fresnel reflecting mirror 15-1 to become parallel light and radiated to the prism plate 15-2. With this configuration, the rear projection display device can be further reduced in size.

  In each of the embodiments described above, the Fresnel lens 15-1, the prism plate 15-2, and the polarization beam splitter plate 15-3 are provided separately, but at least two of these are integrated to form an optical plate. You can also. Integration can be realized by bonding the plates together or processing the front and back surfaces of one transparent plate. For example, when processing the front and back surfaces of one transparent plate, a lens plate is produced in which the irregularities of the Fresnel lens 15-1 are formed on one surface and the irregularities of the prism plate 15-2 are formed on the other surface. can do. Further, it is possible to produce a lens plate in which the unevenness of the prism plate 15-2 is formed on one surface and the unevenness of the polarization beam splitter plate 15-3 (the form in which the polarization separation film is exposed) is formed on the other surface. . The plates can be bonded using a transparent adhesive.

Here, when configuring a dual view display using a liquid crystal display element, two images are displayed on one panel, for each column in the case of dual left and right views, and for each row in the case of dual top and bottom views. In the case of alternate display, a new configuration must be provided in the peripheral circuit. However, in the configuration of the present embodiment, the optical system is simple even compared to the RGB three-plate specification.
In each of the embodiments described above, 3D is also possible if the viewing angle is adjusted. In this embodiment, the left and right two screens can be used to display different TVs on the two screens in the battle game and the living room.

  In addition, if the outermost PBS functional film (polarized light separation film) is arranged so as to be separated vertically, two screens can be formed vertically. If it does so, it will become possible to install in the place of the atrium of 1F and 2F, for example, and to display a respectively different image | video.

  It can also be used for advertising and publicity in public places. It can also be used as BGM (Back Ground Movie) at cafes and restaurants. In theaters, it is possible to show two movies at the same time.

  In this embodiment, it is also possible to use Qaud method, 1PBS method as the optical system other than 3PBS (polarization beam splitter) shown in FIG. It is also possible to replace the PBS function with a wire grid. If RGB color filters are formed on one liquid crystal panel, RGB color display is possible with two panels instead of six panels. Furthermore, if the RBG color LEDs are lit in time series, color display is possible with the configuration shown in FIGS.

  Further, the projection optical system is not limited to the reflective liquid crystal element, but a transmissive liquid crystal element or a device using a DMD (digital microdevice) can also be used.

  The present invention can be applied to a rear projection display device that performs dual view or 3D display.

It is a conceptual diagram for demonstrating the rear projection type display apparatus concerning the 1st Embodiment of this invention. FIG. 3 is an explanatory diagram showing optical paths of first and second image lights that pass through a screen 15 in the configuration shown in FIG. 1. It is a perspective view of polarization beam splitter plate 15-3. It is a conceptual diagram for demonstrating the rear projection type display apparatus concerning the 2nd Embodiment of this invention. FIG. 5 is an explanatory diagram showing optical paths of first and second image lights that pass through a screen 15 in the configuration shown in FIG. 4. It is a figure which shows the projection optical system for the color display used for the rear projection type display apparatus concerning the 3rd Embodiment of this invention. It is a conceptual diagram for demonstrating the rear projection type display apparatus concerning the 4th Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Light source 11 Polarization beam splitter 12, 13 Reflection type liquid crystal element 14 Projection lens 15 Screen 15-1 Fresnel lens 15-2 Prism plate 15-3 Polarization beam splitter plate

Claims (5)

Image light generation means for outputting light emitted from the light source as first image light and second image light having different polarization directions;
Light projection means for projecting the first and second image lights;
A screen for deflecting and emitting the first and second image lights projected from the light projecting means in different directions;
In a rear projection display device comprising:
The screen emits the first and second image light projected from the light projecting means in a direction perpendicular to the plate surface and the first lens plate. A second lens plate that inclines the first and second image light at a certain angle from the vertical direction, and the first and second image light emitted from the second lens plate are emitted in different directions, respectively. A rear projection display device comprising a polarizing beam splitter plate. 2. The rear projection display device according to claim 1 , wherein the image light generating means includes at least one set of a pair of two reflective liquid crystal elements and a polarizing beam splitter.   3. The rear projection display device according to claim 1, wherein at least two of the first lens plate, the second lens plate, and the polarization beam splitter plate are integrated into an optical plate. The rear projection type display device according to claim 1, wherein the rear projection type display device is provided. In the incident screen in which the first image light and the second image light having different polarization directions are deflected and emitted in different directions ,
A first lens plate that emits the incident first and second image light in a direction perpendicular to the plate surface, and the first and second image light emitted from the first lens plate. A second lens plate inclined at a certain angle from the vertical direction; and a polarization beam splitter plate that emits the first and second image lights emitted from the second lens plate in different directions. Feature screen. 5. The screen according to claim 4 , wherein at least two of the first lens plate, the second lens plate, and the polarization beam splitter plate are integrated into an optical plate. .

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