JP5122432B2 - Optical system and projection display device - Google Patents

Description

  The present invention relates to an optical system and a projection display device, and more particularly to an optical system and a projection display device that obtain a high-contrast image and a stereoscopic image in a projection display device (projector).

  Conventionally, a projection display apparatus (projector) is generally a three-plate projector using three modulation devices of R (red), G (green), and B (blue). There are LCD (Liquid Crystal Device) projectors, DLP (Digital Light Processing) projectors, LCOS (Liquid Crystal On Silicon) projectors, and the like.

  FIG. 5 shows a configuration diagram of an example of a conventional optical system. In the figure, illumination light that is white light emitted from a lamp house 11 (xenon lamp, ultra-high pressure mercury lamp, laser diode, light emitting diode, etc.) passes through a condenser lens 12, a cold mirror 13, an integrator 14, and a field lens 15. Then, the light enters the B / RG cross dichroic mirror (cross dichroic mirror) 16. The B / RG cross dichroic mirror 16 separates the red light and the green light in the wavelength band and the blue light in the incident illumination light, and the red light and the green light in the wavelength band are incident on the RG mirror 17. The blue light is incident on the B mirror 18. Light in the red and green wavelength bands reflected by the RG mirror 17 is separated into a green light component and a red light component by an R / G dichroic mirror (dichroic mirror) 19 and enters the field lenses 20 and 24. To do.

  The green light component transmitted through the field lens 20 and the red light component transmitted through the field lens 24 are reflected by the S-polarized components by the wire grids (WG) 21 and 25, which are polarization separation elements, respectively, and further, The light enters the G device 23 and the R device 27 through the four wavelength (λ / 4) plate 22 and the R quarter wavelength (λ / 4) plate 26, and is modulated by the green signal and red signal of the image to be displayed here. After that, the light-modulated P-polarized light passes through the G wave plate 22, the R wave plate 26, and the WGs 21 and 25, and enters the RGB combining dichroic prism 32.

  On the other hand, the blue light reflected by the B mirror 18 is transmitted through the B field lens 28, the S-polarized component is reflected by the WG 29, and further transmitted through the B quarter-wave (λ / 4) plate 30. After being incident on the device 31 and light-modulated with the blue signal of the image to be displayed here, the light-modulated P-polarized light passes through the B wavelength plate 30 and the WG 29 and enters the RGB composite dichroic prism 32. To do.

  The RGB combining dichroic prism 32 recombines the respective P-polarized components of the light-modulated green light, red light, and blue light, and transmits the combined light through the PJ lens 33 to a screen (not shown). ).

  In a projector using such an optical system, the contrast that determines the sharpness of the image is determined by the performance of the optical system and the device alone. Therefore, in recent years, a projector and a liquid crystal display in which contrast is dramatically improved by performing double modulation have been proposed (for example, see Patent Documents 1 and 2).

  FIG. 6 shows a configuration diagram of an example of a conventional optical system that performs double modulation. In the figure, the same components as those in FIG. The conventional optical system shown in FIG. 6 includes an aberration correction lens 34, a 1: 1 relay lens 35, a mirror 36, an aberration correction lens 37, between the RGB combining dichroic prism 32 and the PJ lens 33 of the optical system shown in FIG. A Y-modulating optical system portion including a Y WG 38, a Y wave plate 39, a Y device 40, and a WG analyzer 41 is provided. The aberration correction lenses 34 and 37 are cylindrical lenses for correcting aberrations caused by the optical axis entering the Y WG 38 at an angle of 45 degrees.

  In the conventional optical system shown in FIG. 6, the RGB combined light emitted from the RGB combining dichroic prism 32 passes through the aberration correction lens 34 and the 1: 1 relay lens 35, respectively, and the optical axis direction of the 1: 1 relay lens 35 Is reflected by the mirror 36 for aligning the optical axis direction of the PJ lens 33 and the optical path is changed, then transmitted through the aberration correction lens 37, and the P-polarized light passes through the Y WG 38 and the Y wavelength plate 39 to form the Y device. 40 is incident.

  The Y device 40 is composed of, for example, LCOS, and modulates incident light with the luminance signal of the same image signal as the R signal, G signal, and B signal respectively modulated by the R device 27, the G device 23, and the B device 31. Therefore, the image signal to be displayed is modulated once with the R, G, and B primary color signals, then once with the luminance signal, and modulated twice in total. The modulated light emitted from the Y device 40 is reflected by the Y WG 38 through the Y wave plate 39, and then the P polarization component mixed in the S polarized light is cut by the WG analyzer 41, resulting in high contrast. And then projected onto a screen (not shown) by the PJ lens 33.

  In the general optical system shown in FIG. 5, the contrast depends on the optical F number and the display device performance, and several thousand: 1 is the limit while taking the brightness. However, in the optical system shown in FIG. 6, an image of the first modulation optical system having the same configuration as in FIG. 5 is imaged and modulated on the Y device 40 of the second modulation optical system, and then projected. Therefore, since the contrast obtained by multiplying the contrasts of the first modulation optical system and the second modulation optical system is finally obtained, a contrast of several million: 1 or more can be obtained.

  However, in the projector using the optical system shown in FIG. 6, the resolution (number of pixels) of the Y device 40 finally determines the resolution to be projected. This resolution is the highest resolution of 4k × 2k pixels (horizontal direction 4096 pixels, vertical direction 2160 pixels) even in the highest resolution device currently produced in the market.

  Therefore, in recent years, a projection type display device (projector) having a configuration shown in FIG. 7 for obtaining higher resolution 8k × 4k pixels (horizontal direction 8192 pixels, vertical direction 4320 pixels) is known. The projector shown in FIG. 7 is a projector adapted to a video system called Super Hi-Vision (SHV) proposed by the Japan Broadcasting Corporation. In this conventional projector, for example, the G1G2 image signal output from the hard disk recorder 45 that records and reproduces 16 channels in parallel for HDTV images and the RB image signal are subjected to convergence correction by the convergence correction device 46, and then the RB projector 47. Then, the light modulated with the RB image is projected onto the screen 49, and the light modulated with the G1G2 image is projected onto the screen 49 from the G1G2 projector 48.

  Here, in order to obtain 8k × 4k pixels, the G1G2 projector 48 uses two G devices (G1 device and G2 device) each having 4k × 2k pixels, and each pixel of the G1 device and the G2 device is The pixel pitch Px in the horizontal direction and the pixel pitch Py in the vertical direction are both 4k × 2k pixels. Further, as shown in FIG. 8, the G1G2 projector 48 superimposes images by so-called 45-degree oblique half-pixel shifts that are shifted by Px / 2 in the horizontal direction and Py / 2 in the vertical direction, and the signal also has the G1G2 resolution. In other words, a resolution equivalent to 8 k pixels is obtained by inputting the received signal. On the other hand, the RB projector 47 uses 4k × 2k pixel R and B devices.

  Recently, a display device of 8k × 4k pixels (horizontal direction 8192 pixels, vertical direction 4320 pixels) has been developed, and a full-resolution 8k projector using three of these for R, G, and B is also considered. However, in this method, since the same three-plate system as the conventional optical system shown in FIG. 5 is used, the contrast cannot be dramatically increased. In addition, using three high-resolution devices makes the optical system expensive.

  Therefore, a double modulation projector using a 4k × 2k device for the first modulation optical system and an 8k × 2k device for the second modulation optical system in the optical system shown in FIG. Prototype is released at

JP 2005-181437 A JP 2005-241738 A

  However, although the conventional optical system shown in FIG. 6 can obtain a high-contrast image by double modulation, the physical liquid crystal response time of the display device is the same level as before (about 5 msec) and has high resolution. The moving image blur when the image moves and the afterimage when the screen disappears are conspicuous due to the high resolution of the still image.

  In order to solve this problem with a single display device, particularly when the display device is an LCD or LCOS, the response time of the liquid crystal is determined by the physical properties of the liquid crystal itself, so the physical characteristics of the liquid crystal must be improved. However, if the thickness of the liquid crystal is reduced, the response time will be faster, but the voltage required for driving the liquid crystal will also need to be increased. The current cannot be increased due to the withstand voltage of the IC driver and the withstand voltage of the liquid crystal gap. Has a liquid crystal thickness of 2 to 3 μm and a response time of about 4 to 5 msec, and it is impossible to further reduce the liquid crystal response time.

  7 has a configuration in which light from the RB projector 47 and the G1G2 projector 48 is projected onto the screen 49 on the stack to synthesize an image. Since the projection positions of the G1G2 projector 48 and the G1G2 projector 48 are different from each other, the peripheral registration (or peripheral convergence) is largely shifted particularly on the screen 49. Therefore, a convergence correction device 46 that digitally shifts the RB image signal and superimposes it on the G1G2 image signal is essential.

  The present invention has been made in view of the above points. An optical system capable of obtaining a high-contrast image by performing double modulation, at the same time, drastically shortening the response time required for the light modulation device, and further enabling stereoscopic display. An object is to provide a system and a projection display device.

  In order to achieve the above object, the optical system according to the present invention is a 1 / (2T) second 1 / (2T) second (T is a predetermined value) unit obtained from two consecutive frames of three primary color signals related to a frame image. A modulation optical system for synthesizing the wavelengths of the modulated primary color lights obtained by separately modulating the illumination light for each of the three primary color signals in units of T seconds and outputting the first synthesized light as the first modulated light; The polarization plane of the first modulated light is alternately rotated 90 degrees every 1 / (2T) seconds and stopped rotating, and the first modulated light is alternately S-polarized every 1 / (2T) seconds. 90 degree phase control means for outputting as P-polarized light and a first luminance signal generated from each color signal of the first three primary colors in units of 1 / (2T) seconds of one of the two consecutive frames, The S-polarized light output from the phase control means is optically modulated and output as the second modulated light. A second luminance signal generated from each of the first three primary color signals in units of 1 / (2T) seconds of the other frame out of the two consecutive frames, and 90 degrees phase A second luminance signal modulation optical system that optically modulates the P-polarized light output from the control means and outputs it as a third modulated light, and a second combined light by PS combining the second and third modulated lights. It has the light composition means to produce | generate and the projection means for projecting the 2nd synthetic light, It is characterized by the above-mentioned.

  In order to achieve the above object, the optical system of the present invention includes a first device that optically modulates S-polarized light in the first luminance signal modulation optical system with the first luminance signal, and a second luminance signal. The device response time Rt2 of the second device that optically modulates the P-polarized light in the modulation optical system with the second luminance signal is optically modulated separately for each color signal of the three primary colors in the modulation optical system. It is characterized by being set shorter than each device response time Rt1.

  In order to achieve the above object, an optical system of the present invention includes a pixel of a first device that optically modulates S-polarized light in a first luminance signal modulation optical system with a first luminance signal, and a second device The pixel of the second device that optically modulates the P-polarized light in the luminance signal modulation optical system with the second luminance signal is shifted by 45 degrees oblique half-pixels shifted by a half-pixel pitch in the horizontal and vertical directions. You may arrange | position in the space position.

  In order to achieve the above object, the optical system of the present invention uses each color signal of the first three primary colors and the first luminance signal as a signal related to one of the image for the right eye and the image for the left eye, and the second three primary colors. These color signals and the second luminance signal may be signals relating to the other of the right-eye image and the left-eye image.

  In order to achieve the above object, the projection display apparatus according to the present invention has two consecutive frames of three primary color signals related to a frame image composed in units of 1 / (2T) seconds (T is a predetermined value). Of the two frames, a first luminance signal that is not band-limited is generated based on the color signal of the first three primary colors of one frame, and based on the color signal of the second three primary colors of the other frame of the two frames The first signal generating means for generating the second luminance signal that is not band-limited and the first and second three primary color signals are band-limited, and the band-limited first and second band signals are respectively limited. A maximum value for each pixel is obtained for each of the three primary color signals, and band-limited third and fourth luminance signals are generated based on the band-limited first and second primary color signals. 2 signal generation means and each pixel A color signal correction coefficient is generated based on the maximum value, a first display luminance signal is generated based on the maximum value for each pixel and the third luminance signal, and the maximum value for each pixel is A third signal generating means for generating a second display luminance signal by shifting the luminance signal generated based on the luminance signal of 4 with respect to the first display luminance signal by 1 / (2T) seconds; The signal correction coefficient is multiplied by the band-limited color signals of the first and second three primary colors, and obtained from two consecutive frames of the three primary color signals related to the frame image composed in units of 1 / (2T) seconds. 4th signal generation means for generating color signals of the three primary colors for display in units of 1 / T seconds, and each modulated primary color light obtained by separately modulating the illumination light for each color signal of the three primary colors for display A modulation optical system that performs wavelength synthesis and outputs the first synthesized light as first modulated light; The polarization plane of the first modulated light is alternately rotated 90 degrees and stopped every 1 / (2T) seconds, and the first modulated light is alternately S-polarized and 1 / (2T) seconds. 90 degree phase control means for outputting as P polarized light, and first luminance signal for optically modulating the S polarized light outputted from the 90 degree phase control means with the first display luminance signal and outputting it as second modulated light A second luminance signal modulation optical system that modulates the P-polarized light output from the 90-degree phase control means with a second display luminance signal and outputs it as a third modulated light; And a light combining means for generating a second combined light by PS combining the third modulated light, and a projecting means for projecting the second combined light.

  In order to achieve the above object, a projection display apparatus according to the present invention includes a first device that optically modulates S-polarized light in the first luminance signal modulation optical system with a first luminance signal for display, The device response time Rt2 of the second device that optically modulates the P-polarized light in the luminance signal modulation optical system 2 with the second display luminance signal is optically modulated separately for each of the three primary color signals in the modulation optical system. The third device is characterized in that it is set shorter than each device response time Rt1.

  In order to achieve the above object, a projection display apparatus according to the present invention includes a pixel of a first device that optically modulates S-polarized light in a first luminance signal modulation optical system with a first luminance signal for display, and The pixel of the second device that optically modulates the P-polarized light in the second luminance signal modulation optical system with the second luminance signal for display is shifted by a half-pixel pitch in the horizontal direction and in the vertical direction. It is characterized in that it is arranged at a spatial position shifted by half an angle.

  In order to achieve the above object, the projection display device of the present invention uses the first three primary color signals and the first display luminance signal as signals relating to one of the right-eye image and the left-eye image. The color signals of the second three primary colors and the second display luminance signal may be signals relating to the other image of the right-eye image and the left-eye image.

  According to the present invention, while maintaining the physical characteristics of the liquid crystal itself of the display device, the device response time (liquid crystal response time) associated with the modulation drive is greatly increased by devising the optical system drive method by devising the optical system drive method. This makes it possible to shorten the image and solve the moving image blur caused by the liquid crystal response at the time of moving image playback, which is a drawback of the liquid crystal drive, and to make the displayed image have a very high contrast and high resolution compared to the conventional one. it can. Furthermore, according to the present invention, stereoscopic display using polarized glasses can be performed.

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

  FIG. 1 shows a configuration diagram of an embodiment of an optical system according to the present invention. In the figure, the same components as those in FIG. 6 are denoted by the same reference numerals, and the description thereof is omitted. As shown in FIG. 1, the optical system 100 of the present embodiment includes an optical illumination system part 101, an RGB separation / combination projection system system 102, a 1: 1 relay lens 35, a Y1Y2 image composition part 103, a Y1Y2 projection lens 70, and The switching signal generating circuit 71 is configured. Among these components, the components including the optical illumination system portion 101, the RGB separation configuration projection system system 102, and the 1: 1 relay lens 35 are the same as the components up to the 1: 1 relay lens 35 in FIG. However, the configurations of the R signal, the G signal, and the B signal input to the R device 27, the G device 23, and the B device 31 are different from the conventional ones as described later.

  The optical system 100 of the present embodiment has a high resolution and a high resolution by disposing the 90-degree phase control plate 51, the Y1Y2 image composition portion 103, and the Y1Y2 projection lens 70 on the light exit side of the 1: 1 relay lens 35 described above. In addition to obtaining a contrast image, as described later, half of the light modulation signal frame time is P-polarized light and the other half is S-polarized light. By distributing S-polarized light to the Y1 device 58 side which is a light modulation element, controlling the operation of the 90-degree phase control plate 51 according to each, and driving the Y2 device 64 and the Y1 device 58 alternately in a time-sharing manner, A very fast response time of about ¼, which is impossible with normal liquid crystal response, is achieved.

  The Y1Y2 image composition portion 103 includes a PS separation WG (for example, trade name “Moxtek”) 52 that is a wire grid (WG) type polarization separation element that separates incident light into P-polarized light and S-polarized light, a Y1 field lens 53, A half-wave plate 54, an analyzer 55 for cutting P-polarized light, a Y1WG 56 that reflects S-polarized light and transmits P-polarized light, a Y1 wavelength plate 57 that is a retarder tailored to device characteristics, and Y1 that modulates incident light with a Y1 signal Device 58, Y2 field lens 59, Y2 aberration correction lens 60, analyzer 61, Y2WG62 that reflects S-polarized light and transmits P-polarized light, Y2 wave plate 63 that is a retarder matched to device characteristics, and modulates incident light with Y2 signal Y2 device 64, Y1 aberration correction lens 65, half-wave plate 66, Y1 analyzer 67, PS synthesis WG68, and Y2 Consisting of analyzer 69.

  Here, each of the Y1 device 58 and the Y2 device 64 is composed of, for example, 4 k × 2 k pixels (horizontal direction 4096 pixels, vertical direction 2160 pixels) LCOS (reflection type liquid crystal panel), and they are shown in FIG. The described spatial arrangement is shifted by 45 degrees diagonal half pixels. In the conventional optical system and the projection display apparatus shown in FIGS. 6 and 7, the G1 device and the G2 device are shifted by 45 degrees oblique half pixels. However, in this embodiment, the Y1 device 58 that modulates with the luminance signal is used. Since the Y2 device 64 has a 45-degree oblique half-pixel shift configuration, 8k × 4k (7680 pixels in the horizontal direction and 4320 pixels in the vertical direction) with higher resolution than the conventional one is expected.

  The G device 23, the R device 27, and the B device 31 are composed of, for example, 4 k × 2 k pixels (horizontal direction 4096 pixels, vertical direction 2160 pixels) LCOS (reflection type liquid crystal panel). It is not a pixel shifting configuration. The G device 23, the R device 27, and the B device 31, and the Y1 device 58 and the Y2 device 64 are all driven by a 60 Hz signal.

  The Y1 analyzer 67 is tilted by about 10 degrees so that the reflected light does not return to the Y1 device 58. Similarly, the Y2 analyzer 69 is tilted by about 10 degrees so that the reflected light does not return to the Y2 device 64. Further, the half-wave plate 54 is provided to rotate the polarization plane of the S-polarized light reflected by the PS separation WG 52 by 1/2 wavelength so as to make the P-polarized light in order to make the P-polarized light transmitted by the Y1WG 56. . Further, the half-wave plate 66 is provided to transmit the PS composite WG 68 as a P-polarized light by rotating the polarization plane of the S-polarized light from the Y1 device 58 reflected by the Y1WG 56 by 1/2 wavelength (90 degrees). It has been.

  Furthermore, the 90-degree phase control plate 51 performs either an operation of rotating the polarization plane of the incident polarized light by 90 degrees to output, or an operation stop of outputting the incident polarized light as it is without rotating the polarization plane by 90 degrees. Thus, it is controlled by a switching signal from the outside. The switching signal generation circuit 71 is phase-locked with the luminance signal (Y1 video signal and Y2 video signal), R signal, G signal, and G signal to be displayed, every 90 periods (1/120 seconds). A switching signal for controlling the phase control plate 51 so as to alternately repeat the operation of rotating the polarization plane by 90 degrees and stopping the operation is generated.

  Next, the operation of the present embodiment will be described.

  As will be described later, the R device 27, the G device 23, and the B device 31 are each 1/60 obtained from two consecutive frames of the R signal, the G signal, and the B signal that are configured in units of 1/120 seconds. The R light, G light, and B light modulated (first modulation) by the R signal, G signal, and B signal per second are reflected. These RGB three primary color lights are synthesized by the RGB synthesis dichroic prism 32 and emitted as synthesized light. The combined light passes through the 1: 1 relay lens 35 for forming an RGB image on the Y1 device 58 and the Y2 device 64, and enters the 90-degree phase control plate 51.

  The 90-degree phase control plate 51 is controlled by the switching signal supplied from the switching signal generating circuit 71 and is synchronized with the luminance signal (Y1 video signal and Y2 video signal), R signal, G signal, and G signal to be displayed. The 90-degree rotation operation of the incident polarization plane and the stop of the rotation operation of the polarization plane are alternately repeated every half period (1/120 seconds) of one frame.

  The operation of the 90-degree phase control plate 51 by the switching signal generation circuit 71 will be described in more detail with reference to the timing chart of FIG.

FIG. 2A schematically shows an R signal, a G signal, and a B signal, which are input video signals of this optical system, in units of 1/120 seconds. However, the drive frequency of the G device 23, the R device 27, the B device 31, the Y1 device 58, and the Y2 device 64 is 60 Hz. FIG. 2B schematically shows a G signal G _HDR60 , an R signal R _HDR60 , and a B signal B _HDR60 having a frequency of 60 Hz input to the G device 23, the R device 27, and the B device 31 in FIG. 1. . 2C is a Y1 video signal having a frame frequency of 60 Hz input to the Y1 device 58 in FIG. 1, and FIG. 2D is a frame frequency of 60 Hz input to the Y2 device 64 in FIG. A Y2 video signal is shown typically. Further, FIG. 2E shows a switching signal supplied from the switching signal generation circuit 71 to the 90-degree phase control plate 51. This switching signal is a rectangular wave having a period of 1/60 seconds and inverted every 1/120 seconds synchronized with the input video signal.

  When the switching signal shown in FIG. 2 (E) is “0” (low level), the 90-degree phase control plate 51 is a polarization of composite light composed of RGB three primary colors transmitted through the 1: 1 relay lens 35 that is S-polarized light. An operation of rotating the surface by 90 degrees is performed to transmit P-polarized light. Further, the 90-degree phase control plate 51 is a composite light composed of RGB three primary color lights that have passed through the 1: 1 relay lens 35 that is S-polarized light when the switching signal shown in FIG. 2E is “1” (high level). The operation of rotating the polarization plane is stopped and transmitted as S-polarized light as it is. Therefore, the 90-degree phase control plate 51 alternately outputs combined light that is P-polarized light and combined light that is S-polarized light every 1/120 second.

  Returning again to FIG. The Y1Y2 image synthesizing part 103 is output from the 1: 1 relay lens 35, and further, the synthesized light whose polarization plane is controlled to be rotated or non-rotated 90 degrees by the 90-degree phase control plate 51 is once transmitted to the Y1 device 58 and the Y2 device 64. An image is formed and modulated, and the modulated light is again subjected to PS composition by the PS composition WG 68 and is incident on the Y1Y2 projection lens 70.

  That is, the details of the Y1Y2 image composition portion 103 will be described. In the period in which the synthesized light output from the 90-degree phase control plate 51 is P-polarized light (period in which the switching signal is “0”), the P-polarized light is After passing through the PS separation WG52, which is a wire grid (WG) type polarization separation element, and further through the Y2 field lens 59 and the Y2 aberration correction lens 60 for collecting the light from the 1: 1 relay lens 35 on the element The S-polarized light component is cut by the analyzer 61. The Y2 aberration correction lens 60 corrects focus deterioration, particularly astigmatism, that occurs when P-polarized light passes through the PS separation WG52 and Y2WG62 that are arranged with a half-pixel offset by 45 degrees with respect to the optical axis of incident light. For cylindrical lenses and wedge glass.

  The analyzer 61 may disturb the polarization when the P-polarized light passes through the Y2 field lens 59 and the Y2 aberration correction lens 60. Even if the polarization is disturbed, the analyzer 61 cuts the S-polarized component and increases the extinction ratio of the P-polarized light. For example, it is composed of WG. However, if there is no influence of the contrast of the Y2 device 64, the analyzer 61 can be deleted. The P-polarized light that has passed through the analyzer 61 passes through the Y2WG 62, is incident on the Y2 device 64 through the Y2 wavelength plate (retarder) 63 for phase adjustment of the light, and is modulated by the Y2 video signal.

  The P-polarized light that has been incident on the Y2 device 64 and modulated is light that is a mixture of S-polarized light and P-polarized light, and is reflected by the Y2 device 64. The S2 component is reflected by the Y2WG 62 through the Y2 wave plate (retarder) 63. The remaining P polarization component returns to the 1: 1 relay lens 35. The S-polarized light reflected by the Y2WG 62 is transmitted through the Y2 analyzer 69 to increase the extinction ratio of the S-polarized light, reflected by the PS composite WG 68, and then projected onto a screen (not shown) by the Y1Y2 projection lens 70. The Y2 analyzer 69 cuts the leaked P-polarized light from the back-surface reflection when the P-polarized light is transmitted through the Y2WG 62. Further, the Y2 analyzer 69 is inclined about 10 degrees with respect to the lens optical axis, and is provided so that the reflected light of the Y2 analyzer 69 does not return to the Y2 device 64.

  On the other hand, during the period in which the combined light output from the 90-degree phase control plate 51 is S-polarized light (the period in which the switching signal is “1”), the S-polarized light has an image size and position that are imaged on the Y1 device 58. The light passes through the fine-adjusting Y1 field lens 53 and is further shifted by ½ wavelength by the ½ wavelength plate 54 to be once P-polarized light. For the P-polarized light from the half-wave plate 54, an unnecessary S-polarized component mixed to increase the extinction ratio is removed by the analyzer 55, transmitted through the Y1WG 56, and further, a Y1 wavelength plate for adjusting the phase of light ( Retarder) 57 is incident on Y1 device 58 and modulated with a Y1 video signal. Similar to the Y2 aberration correction lens 60, an aberration correction lens for correcting the transmitted light of the Y1WG 56 may be provided on the incident side of the Y1WG 56.

  The P-polarized light that has been incident on the Y1 device 58 and modulated is a mixture of S-polarized light and P-polarized light, and is reflected by the Y1 device 58. The S-polarized light component is reflected by the Y1WG 56 through the Y1 wave plate (retarder) 57. The remaining P-polarized component returns to the PS separation WG52. The S-polarized light reflected by the Y1WG 56 is corrected by the Y1 aberration correction lens 65 for astigmatism when passing through the PS composite WG68 because the optical axis is obliquely inclined by 45 degrees in the subsequent PS composite WG68. The Y1 aberration correction lens 65 is made of, for example, a cylindrical lens or wedge glass.

  The S-polarized light transmitted through the Y1 aberration correction lens 65 is returned to the P-polarized light by the half-wave plate 66 and then reflected by the Y1WG 56 by the Y1 analyzer (P-polarized light transmission, S-polarized light cut) 67 in order to maintain high contrast. The P-polarized component mixed with the S-polarized light (in fact, unnecessary light is the S-polarized component because it passes through the half-wave plate 66) is cut, and then enters the PS composite WG 68. Here, the Y1 analyzer 67 is inclined about 10 degrees with respect to the lens optical axis, and is provided so that the reflected light of the Y1 analyzer 67 does not return to the Y1 device 58.

  The PS combining WG 68 combines the P-polarized light from the Y1 analyzer 67 modulated by the Y1 device 58 and the S-polarized light from the Y2 analyzer 69 modulated by the Y2 device 64, and passes the combined light through the Y1Y2 projection lens 70. Project onto a screen (not shown). Note that the Y1 device 58 and the Y2 device 64 have a structure in which their positions can be mechanically moved by a micromotor and matched at the pixel level.

Next, the relationship between the display timing of each device of this embodiment and the projection image output obtained by multiplying the first light modulation and the second light modulation will be described with reference to the timing chart of FIG. In this embodiment, 120 Hz double speed display is targeted. In this case, assuming that the number of frames at 120 Hz is n and the number of frames at 60 Hz is m, the relationship between them is n = 2 · m, 2 · m + 1, 2.・ M + 2, ...
It can be expressed as.

  The target input video signal at 120 Hz shown in FIG. 2A is expressed by the following (1). Further, the RGB video signal and the luminance signal at 120 Hz are represented by the following (2) and (3), respectively. Here, in order to simplify the explanation, the γ value of the γ characteristic is “1.0”, and the G device 23, the R device 27, the B device 31, the Y1 device 58, and the Y2 device 64 have the same number of pixels. The following i and j are assumed to be pixel positions on the screen.

Rin (n, i, j), Gin (n, i, j), Bin (n, i, j) (1)
R _HDR120 (n, i, j), G _{HDR 120} (n, i, j), B _{HDR 120} (n, i, j) (2)
Yin (n, i, j) (3)
At this time, the relationship between the luminance signal Y, the R signal, the G signal, and the B signal is defined as shown in Equation (4).

_{Y = C R · R + C} G · G + C B · B (4)
However, shows a constant (4) wherein, _{C R} is a constant of the R signal, _{C G} is a constant of the G signal, _{C B} is the B signal.

Also, the values at the pixel positions i and j of the m frame of the R signal R _HDR60 , G signal G _HDR60 , and B signal B _HDR60 having a frame frequency of 60 Hz shown in FIG.

R _HDR60 (m, i, j) = MAX {R _HDR120 (2m-1, i, j), R _HDR120 (2m, i, j)} (5a)
G _HDR60 (m, i, j) = MAX {G _HDR120 (2m-1, i, j), G _HDR120 (2m, i, j)} (5b)
B _HDR60 (m, i, j) = MAX {B _HDR120 (2m-1, i, j), B _HDR120 (2m, i, j)} (5c)
That, R signal R _HDR60, G signal G _HDR60, B signal pixel position i of m frames of B _HDR60, value at j, the successive frame frequency 120Hz of the R signal R _HDR120, G signal G _HDR120, B signal B _HDR120 The larger value of the values at the pixel positions i and j of 2 frames (2m-1 frame and 2m frame) is shown. The R signal R _HDR60 , the G signal G _HDR60 , and the B signal B _HDR60 may be an average value of two consecutive frames of the R signal R _HDR120 , the G signal G _HDR120 , and the B signal B _HDR120 .

  Further, the values at the pixel positions i and j of the m frame of the Y1 video signal and the Y2 video signal with the frame frequency of 60 Hz shown in FIGS. 2C and 2D are defined by the following equations.

Y1 (m, i, j) = Y in (2m, i, j) / {C R · R HDR60 (m, i, j) + C G · G HDR60 (m, i, j)
+ C _B · B _HDR60 (m, i, j)} (6a)
Y2 (m, i, j) = Y in (2m-1, i, j) / {C R · R HDR60 (m, i, j) + C G · G HDR60 (m, i, j)
+ C _B · B _HDR60 (m, i, j)} (6b)
That, Y1 video signal and Y2 video signals m frames, the luminance signal _{Y in} the frame frequency 120Hz of 2m frame, R signal m frame R _HDR60, G signal G _HDR60, from B signal B _HDR60 (4) equation It is a signal divided by a value generated by matrix conversion.

  As described above, in the period when the switching signal shown in FIG. 2E is “0”, the combined light output from the 90-degree phase control plate 51 is P-polarized light, and the RGB video signal is transmitted to the Y2 device 64. Since it is irradiated and modulated by the Y2 video signal (hereinafter also referred to as luminance signal Y2) shown in FIG. 2D, the Y1Y2 projection lens 70, as schematically shown in FIG. The video signal and the RGB video signal are projected on the screen.

  On the other hand, in the period in which the switching signal shown in FIG. 2E is “1”, the combined light output from the 90-degree phase control plate 51 is S-polarized light, and the RGB video signal is applied to the Y1 device 58. Since it is modulated by the Y1 video signal (hereinafter also referred to as the luminance signal Y1) shown in FIG. 2C, the Y1Y2 projection lens 70 is connected to the Y1 video signal as schematically shown in FIG. The RGB video signal is projected on the screen.

  The double modulation optical system 100 of the present embodiment, in which the modulated light output from the first modulation optical system by the RGB separation / combination projection system system 102 is modulated again by the second modulation optical system by the Y1Y2 image synthesis unit 103. The apparent resolution is determined by the resolution of the Y1 device 58 and the Y2 device 64 of the second modulation optical system. Therefore, in this embodiment, the Y1 device 58 and the Y2 device 68 each composed of, for example, 4 k × 2 k pixels (horizontal direction 4096 pixels, vertical direction 2160 pixels) LCOS are shifted by 45 degrees oblique half-pixels as described above. Therefore, 8k × 4k (7680 pixels in the horizontal direction and 4320 pixels in the vertical direction) with higher resolution than the conventional one is expected.

  Furthermore, according to the present embodiment, the Y1 device 58 and the Y2 device 64 driven at 60 Hz are alternately driven in a time-sharing manner in units of 1/120 seconds, so that it is used for an FPD (flat panel liquid crystal display). It is expected to improve the video response, similar to the double speed drive technology.

  As described above, according to the present embodiment, the light modulated by the Y1 video signal and the Y2 video signal, which are alternately switched every 1/120 seconds with a shift of 1/2 frame, is projected. Although it is 60 Hz drive, the same effect as 120 Hz drive is equivalently obtained, and the response speed of the moving image can be increased by about 4 times. As a result, according to the present embodiment, a high-speed response can be obtained, and moving image blur due to the liquid crystal response at the time of moving image reproduction, which is a drawback of liquid crystal driving, can be solved.

  Further, according to the present embodiment, the contrast of the image obtained by the first modulation optical system by the RGB separation / combination projection system system 102 is 1000: 1, and the second modulation optical system by the Y1Y2 image synthesis portion 103 can obtain. When the contrast of the image is 1000: 1, the total contrast is multiplied by 1000 × 1000, and a very high-contrast image of 1 million: 1, which is much higher than the conventional two-unit stack, is obtained. Furthermore, according to the present embodiment, compared with the case where the G signal is duplicated, the luminance signal is duplicated, so that a higher resolution image can be obtained.

  In addition, the optical system 100 according to the present embodiment includes the response time Rt1 of the G device 23, the R device 27, and the B device 31 used for the light modulation of the RGB separation / synthesis projection system system 102, and the light of the Y1Y2 image composition portion 103. The total response time (Rt1∩Rt2) with the response time Rt2 of the Y1 device 58 and the Y2 device 64 used for modulation can be shorter than only Rt1 or only RT2. Here, “∩” in the total response time (Rt1∩Rt2) is a symbol representing the time (AND) in which both Rt1 and Rt2 overlap.

  For example, when the above response times Rt1 and Rt2 are set to the same 5 msec, the response time is multiplied in the same manner as the contrast, and the total response time is 2.5 msec, which is about half of the response time. Basically, the RGB separation / combination projection system system 102 that performs the first light modulation functions as a backlight of the RGB image. On the other hand, in the Y1 device 58 and the Y2 device 64 used for the second light modulation, the moving image blur is greatly improved when the response time is increased (because the response of the human eye is more sensitive to the change in luminance than the color). .) Ideally, if the response time of a liquid crystal display is 1 msec or less, the response time of a display using a CRT (cathode ray tube) will be much closer, and there will be an effect of improving motion blur such as black insertion technology and overshoot of the liquid crystal flat panel. Works effectively.

  Next, an embodiment of a projection display device according to the present invention will be described.

  FIG. 3 shows a system block diagram of an embodiment of a projection display apparatus according to the present invention. In the figure, a projection display device 80 is reproduced and output from a super high-definition camera 81 that picks up a desired subject, a super high-definition recorder 82 that records / reproduces an image pickup signal of the super high-definition camera 81, and the super high-definition recorder 82. Green signals G1 and G2, red signals R1 and R2, and blue signals B1 and B2 are received as inputs, and the input signals are subjected to matrix conversion to output two types of luminance signals Y1 and Y2 and color signals r, g, and b. It comprises a matrix conversion decoder 83 and an optical system 100 that projects an optical image onto a screen (not shown).

  Note that primary color light generated from a computer image, a film image, or the like can be used instead of the super high-definition camera 81 shown in FIG.

  The super high-definition camera 81 has a total of three solid-state image sensors each having a horizontal direction of 7680 pixels and a vertical direction of 4320 pixels, one for green light, one for red light, and one for blue light. Further, 12-bit primary color signals composed of R1, B1, and G1 and tri-primary color signals composed of R2, B2, and B2 are output at a frame rate of 60p (vertical frequency of 60 Hz).

  When the super high-definition camera 81 is compatible with the double speed, the super high-definition camera 81 inputs the three primary color signals composed of R1, B1, and G1 and the three primary color signals composed of R2, B2, and B2 every 1/120 second. It is input alternately. In addition, when the super high-definition camera 81 does not support double speed, the super high-definition recorder 82 generates a frame signal of three primary color signals composed of R2G2B2 from the next frame correlation inside the super high-definition recorder 82. The super high-definition recorder 82 takes in and reproduces the three primary color signals of real 8k × 4k pixels and a frame rate of 60p in 12 bits. Transmission is performed by optical multiplexing of a signal such as HDMI capable of 12-bit transmission.

  The matrix conversion decoder 83 has a configuration described later, and two luminance signals (Y1 video signal and Y2 video signal) having a quantization bit number of 12 bits from the input three primary color signals (R1G1B1 / R2G2B2) having a quantization bit number of 12 bits. Then, signals for a total of five channels of three primary color signals (r signal, g signal, b signal) having a quantization bit number of 10 bits are generated and output to the optical system 100.

  The optical system 100 is the above-described optical system (projector in a narrow sense) having the configuration shown in FIG. 1, and receives signals Y1, Y2, r, g, and b from the matrix conversion decoder 83 and displays these signals on a screen (not shown). Project to.

  FIG. 4 shows a block diagram of an embodiment of the matrix conversion decoder 83 together with a part of FIG. FIG. 4 shows the switching signal generation circuit 71 and the 90-degree phase control plate 51 shown in FIG. 1, and other circuit portions constitute one embodiment of the matrix conversion decoder 83.

In FIG. 4, a matrix conversion decoder 83 outputs a 120 Hz primary color signal (a first three primary color signal composed of a red signal R1, a green signal G1, and a blue signal B1) output from the Super Hi-Vision recorder 82 and switched every 1/120 second. , A red signal R 2, a green signal G 2, and a blue signal B 2) as an input, and the input three primary color signal is once subjected to inverse γ correction by the inverse γ correction unit 91 and returned to a gamma 1 linear signal. The Y1Y2 creation unit 92 creates a first luminance signal Y1 _FULL in a frequency band that is not band-limited from the first three primary color signals (R1, G1, B1) by a known matrix computation. create together, the second luminance signal Y2 _FULL frequency band that is not band-limited from the second three primary color signals (R2, G2, B2) to To.

Further, the matrix conversion decoder 83 attenuates the high frequency components of the three primary color signals from the inverse γ correction unit 91 by the low frequency filter (LPF) 93 so that the primary color signals R1 _LPF , G1 _LPF , B1 _{LPF of the} low frequency components R2 _LPF , G2 _LPF , and B2 _LPF are taken out and supplied to the maximum value, Y1Y2 calculation unit 94 and multiplier 96, respectively. The maximum value, Y1Y2 calculation unit 94 calculates the maximum value MAX of the band-limited primary color signals R1 _LPF , G1 _LPF , B1 _LPF, R2 _LPF , G2 _LPF , B2 _LPF for each pixel and band-limited. The low frequency component Y1 _LPF of the first luminance signal is obtained from the first three primary color signals (R1 _LPF , G1 _LPF , B1 _LPF ) by a known matrix operation, and the band-limited second three primary color signals (R2 _LPF). , G2 _LPF , B2 _LPF ), the low frequency component Y2 _LPF of the second luminance signal is obtained by a known matrix operation.

The coefficient and luminance signal generation unit 95 includes luminance signals Y1 _FULL and Y2 _FULL from the Y1Y2 creation unit 92, a maximum value, a maximum value MAX from the Y1Y2 calculation unit 94, and low frequency components Y1 _LPF and Y2 _{LPF of the} luminance signal. And the coefficient C and the luminance signals Y1 and Y2 are obtained by the following calculation formula.

C = (α / β) ^1/2 · (MAX) ^-1/2 (7)
Y1 = Y1 _FULL・ (β / α) ^1/2・ (MAX) ^1/2 / Y1 _LPF (8)
Y2 = Y2 _FULL・ (β / α) ^1/2・ (MAX) ^1/2 / Y2 _LPF (9)
Here, the calculation formula of the coefficient C and the luminance signals Y1 and Y2 will be described in more detail. The input video signal supplied to the matrix conversion decoder 83 is a primary color signal (R1, G1 and B1, or R2, G2 and B2) output from the super high vision recorder 82. The input three primary color signals R1, G1 and B1 and R2, G2 and B2 are the three primary color signals input every 1/120 seconds. The three light outputs F _1R , F _1G , and F _1B output in 1/60 second units corresponding to these three primary color signals can be expressed by the following equations, respectively.

F _1R = F ₁ (r) = A · (r1 + r2) + α (10a)
F _1G = F ₁ (g) = A · (g1 + g2) + α (10b)
F _1B = F ₁ (b) = A · (b1 + b2) + α (10c)
In the equations (10a) to (10c), α is a flare component of light output from the RGB separation / combination projection system system 102. A is a proportionality constant. R1, g1, b1, r2, g2, and b2 represent signals when the γ values of the input primary color signals R1, G1, B1, R2, G2, and B2 are set to “1.0”.

Further, since the light outputs F _1R , F _1G , and F _1B are further modulated by the Y1Y2 image composition portion 103 shown in FIG. 1, the RGB components F _2R , F _2G , and F _2B of the final light output are These can be expressed by the following formulas.

F _2R = F ₁ (r) ・ (A ・ Y + β)
＝ A ²・ Y ・ (r1 + r2) + A ・ Y ・ α + A ・ (r1 + r2) ・ β + α ・ β
= Y · (r1 + r2) + Y · α + (r1 + r2) · β + α · β (11a)
F _2G = F ₁ (g) ・ (A ・ Y + β)
= A ² · Y · (g1 + g2) + A · Y · α + A · (g1 + g2) · β + α · β
= Y · (g1 + g2) + Y · α + (g1 + g2) · β + α · β (11b)
F _2B = F ₁ (b) ・ (A ・ Y + β)
＝ A ²・ Y ・ (b1 + b2) + A ・ Y ・ α + A ・ (b1 + b2) ・ β + α ・ β
= Y · (b1 + b2) + Y · α + (b1 + b2) · β + α · β (11c)
However, in the equations (11a) to (11c), β is a flare component of light output from the Y1Y2 image composition portion 103. Y is a luminance signal when the γ values of the luminance signals Y1 and Y2 supplied to the Y1 device 58 and Y2 device 64 are “1.0” (in the following description, for convenience, the luminance signals Y1 and Y2 Are collectively shown as a luminance signal Y). Furthermore, the proportionality constant A is “1” for simplicity.

By the way, in the case of a normal three-plate projector, the final outputs F _2R , F _2G , and F _2B are proportional to the input video signal, but there is a flare or each device of the RGB separation / synthesis projection system system 102. This is not the case when the number of pixels and the number of pixels of each device in the Y1Y2 image composition portion 103 are different. Therefore, to simplify the description, it is assumed that the number of pixels of each device of the RGB separation / combination projection system system 102 is smaller than the number of pixels of each device of the Y1Y2 image composition portion 103. In this case, the video signals r1, g1, b1, r2, g2, and b2 do not have a higher frequency component than the input video signals R1, G1, B1, R2, G2, and B2.

Therefore, the input video signals R1, G1, B1, R2, G2, and B2 are passed through the LPF 93, and the low frequency component R1 _{LPF of} the primary color signal having the same frequency characteristics as the video signals r1, g1, b1, r2, g2, and b2. , G1 _LPF , B1 _LPF, R2 _LPF, G2 _LPF , B2 _LPF, and the maximum value among them is MAX (this is a different value for each pixel). R1 _LPF , G1 _LPF , B1 _LPF, R2 _LPF, G2 _LPF , B2 _LPF can be expressed by the following equations using the maximum values. Here, rx, gx, and bx are values that satisfy 0 ≦ rx, gx, and bx <1.0.

R _LPF = R1 _LPF + R2 _LPF = MAX · r _x (12a)
G _LPF = G1 _LPF + G2 _LPF = MAX · g _x (12b)
B _LPF = B1 _LPF + B2 _LPF = MAX · b _x (12c)
For the convenience of explanation, assuming that R _LPF is MAX, F _2R in the equation (11a) is expressed by the following equation if it is ignored because the value of the α · β component is small.

F _2R ≒ Y (r1 + r2) + Y ・ α + (r1 + r2) ・ β (13)
From this, Y and (r1 + r2) that minimize the flare component are calculated. When there is no flare component (α = β = 0), since F _2R = R _LPF , the following equation is obtained from equation (12a) and equation (13) substituting α = β = 0.

F _2R ≒ Y · (r1 + r2) = R _LPF = r _x · MAX (14)
In the equation (13), the condition for minimizing the influence of flare is the following equation.

Y · α = (r1 + r2) · β (15)
Therefore, Expressions (16) and (17) are obtained by Expressions (14) and (15).

(r1 + r2) = r _x · (α / β) ^1/2 · (MAX) ^1/2 (16)
Y = (β / α) ^1/2 · (MAX) ^1/2 (17)
Next, the green signal g will be described. Since Y has already been obtained, assuming that F _2G is equal to G _{LPF in} equation (11b) and ignoring flare components α and β, the following equation is obtained from equations (11b) and (12b).

F _2G ≒ Y · (g1 + g2) = G _LPF = g _x · MAX (18)
Therefore, the green signal g is expressed by the following equation from the equations (18) and (17).

(g1 + g2) = g _x · MAX / Y = g _x · (α / β) ^1/2 · (MAX) ^1/2 (19)
Similarly, the blue signal b can be obtained.

In the above calculation, the low frequency component R _LPF of the red signal is described as MAX. However, if expressed as follows, any of R _LPF , G _LPF , and B _LPF is MAX. To establish.

(r1 + r2) = r _x · (α / β) ^1/2 · (MAX) ^1/2 (20a)
(g1 + g2) = g _x · (α / β) ^1/2 · (MAX) ^1/2 (20b)
(b1 + b2) = b _x · (α / β) ^1/2 · (MAX) ^1/2 (20c)
Y = (β / α) ^1/2 · (MAX) ^1/2 (20d)
The multiplier 96 of FIG. 4 outputs the low-frequency component primary color signals R1 _LPF , G1 _LPF , B1 _LPF, R2 _LPF, G2 _LPF , B2 _LPF output from the _LPF 93, and the coefficient and luminance signal generation unit 95. By multiplying the coefficient C by the following equation, a 10-bit red signal r, a green signal g, and a blue signal b are generated.

r = r1 + r2 = C. (R1 _LPF + R2 _LPF ) = _{C.R LPF} (21a)
g = g1 + g2 = C. (G1 _LPF + G2 _LPF ) = _{C.G LPF} (21b)
b = b1 + b2 = C. (B1 _LPF + B2 _LPF ) = _{C.B LPF} (21c)
As a result, the coefficient C is expressed by the above-described equation (7) from the equations (14), (18), (20a) to (20d), (21a) to (21c), and the like.

  The red signal r, green signal g, and blue signal b are supplied to the rgb γ correction unit 97 and γ corrected, respectively, and then the R device 27 shown in FIG. 1 in the optical system 100 in FIG. The G device 23 and the B device 31 are supplied.

By the way, although it calculated as a thing without a high frequency component from (20a) type | formula to (20d) type | formula, actually a high frequency component exists. For this reason, when the luminance signal Y is generated using the signals r, g, and b in the equations (20a) to (20c), the high frequency component is lost. For the luminance signal Y, it is necessary to generate the luminance signal Y1 and the luminance signal Y2 supplied to the Y1 device 58 and the Y2 device 64 shown in FIG. In view of these, the Y1Y2 creation unit 92 in FIG. 4 generates the first luminance signal Y1 _FULL and the second luminance signal Y2 _FULL in the frequency bands that are not band-limited, as described above. These luminance signals Y1 _FULL and Y2 _FULL are expressed by the following equations.

_{Y1 FULL = C 1 · R1 +} C 2 · G1 + C 3 · B1 (22a)
_{Y2 FULL = C 1 · R2 +} C 2 · G2 + C 3 · B2 (22b)
Here, C ₁ , C ₂ , and C ₃ are contribution coefficients to luminance components by the input video signals R 1 (R 2), G 1 (G 2), and B 1 (B 2). In the case of a high-definition signal, 0.2126, 0.7152, and 0.0722, respectively. It is.

4 generates a first luminance signal Y1 _LPF and a second luminance signal Y2 _{LPF in} a frequency band that is band-limited by the maximum value Y1Y2 calculation unit 94 shown in FIG. These luminance signals Y1 _LPF and Y2 _LPF are expressed by the following equations.

_{Y1 LPF = C 1 · R1 LPF} + C 2 · G1 LPF + C 3 · B1 LPF (23a)
_{Y2 LPF = C 1 · R2 LPF} + C 2 · G2 LPF + C 3 · B2 LPF (23b)
Here, Y in the equations (17) and (20d) is band-limited, and there is no high frequency component. Therefore, in order to reproduce the high frequency component, the luminance signal of the equations (17) and (20d) is used. It is necessary to multiply Y (Y _LPF ) by the correction term D to output a luminance signal Y _Full that is not band-limited. That is, Y _Full = D · Y _LPF .

Therefore, the coefficient and luminance signal generation unit 95 generates the luminance signals Y1 and Y2 represented by the above-described equations (8) and (9). In the equation (8), Y1 _FULL / Y1 _LPF is the correction term D, and in the equation (9), Y2 _FULL / Y2 _LPF is the correction term D.

  The Y1 γ correction unit 98 in FIG. 4 γ-corrects the luminance signal Y1 calculated by the equation (8) from the coefficient and luminance signal generation unit 95 and converts it into a Y1 video signal having a quantization bit number of 12 bits. The signal is supplied to the delay unit 110, and is supplied to the Y1 device 58 in the optical system 100 shown in FIG. At the same time, the Y2 γ correction unit 99 in FIG. 4 γ-corrects the luminance signal Y2 calculated by the equation (9) from the coefficient and luminance signal generation unit 95, and converts it to Y2 having a quantization bit number of 12 bits. The video signal is supplied to the Y2 device 64 in the optical system 100 shown in FIGS. Therefore, as shown in FIG. 2C, the Y1 video signal is delayed from the Y2 video signal shown in FIG.

  The γ value (= γ1) in the rgb γ correction unit 97 and the γ values (= γ2) in the Y1 γ correction unit 98 and the Y2 γ correction unit 99 are the first modulated light and the second modulated light. Are multiplied so that the total γ value becomes “2.2” and γ1 and γ2 are as close as possible. For example, γ1 = 1.0 and γ2 = 1.2 are selected. In this case, since the exponent is a multiplication, the total γ value is 2.2 (= 1.0 + 1.2).

  A color image is projected onto a screen (not shown) from the optical system 100 to which the luminance signal Y1, Y2 and the five color signals r, g, and b are supplied from the matrix conversion decoder 83 having such a configuration.

  As described above, the projection type display device 80 of the present embodiment shown in FIG. 3 can eliminate the convergence correction by configuring the SHV with one unit, and also performs the double modulation, so that two units are stacked. Thus, a much higher contrast of 1 million: 1 or more can be obtained, and moreover, a higher resolution image can be obtained because the luminance signal is duplicated as compared with a device that duplicates the G signal.

  In addition, this invention is not limited to the above embodiment, A various other modification can be considered. For example, in the optical system 100 of the embodiment of FIG. 1, the Y1 video signal supplied to the Y1 device 58 and the Y2 video signal supplied to the Y2 device 64 are shifted by 1/120 seconds (1/2 frame), The Y1 device 58 and the Y2 device 64 are alternately driven by incident P-polarized light and S-polarized light every 1/120 second. Therefore, the optical system 100 uses, for example, the Y1 video signal and the first three primary color signals (R1, G1, B1) of the generation element as signals related to one of the right-eye image and the left-eye image, and the Y2 video signal. And the second three primary color signals (R2, G2, B2) of the generation element thereof are signals related to the other image, so that it can be applied to a stereoscopic display system in which a viewer watches with polarized glasses.

  Further, in the optical system 100, when the input video signal corresponds to 120 Hz, the same effect as the double speed drive is obtained with 60 Hz. However, if the input RGB video signal is 60 Hz, it is shown in FIG. This can be dealt with by doubling the image reading speed in the super high-definition decoder 82 before the input of the matrix conversion decoder 83.

  Further, the present invention remodulates the modulated light output from the first modulation optical system by the RGB separation / synthesis projection system system 102 as shown in FIG. 1 by the second modulation optical system by the Y1Y2 image synthesis unit 103. In the dual modulation optical system 100, the response time Rt2 of the Y1 device 58 and the Y2 device 64 used for the light modulation of the Y1Y2 image composition portion 103 is used as the G device used for the light modulation of the RGB separation / synthesis projection system system 102. 23, the total response time (Rt1∩Rt2) is also shortened by making it shorter than the response time Rt1 of the R device 27 and the B device 31.

  This modification will be described in detail below. In the case of the same liquid crystal thickness (cell gap), a liquid crystal panel used as a display device quickly reaches saturation with a lower driving voltage as the wavelength of incident light is shorter. For this reason, when the same liquid crystal panel is used as the G device 23, the R device 27, and the B device 31, the B device 31 to which the primary color light B having the shortest wavelength is incident is saturated at the lowest drive voltage. To reach. Further, the G device 23 and the R device 27 do not reach saturation in the same time as the B device 31 unless the drive voltage is increased higher than that of the B device 31. On the other hand, the Y1 device 58 and the Y2 device 64 are driven by the same drive voltage because the same RGB composite light is incident thereon, but the drive voltage is matched to the B light component having the shortest wavelength in the incident RGB composite light. Is determined.

  For this reason, for example, in the case of a signal of 100% white, the driving voltages of the R light component and the G light component are matched to the light that can be modulated by the driving voltage of the incident B light component with respect to the Y1 device 58 and the Y2 device 64 To adjust the white balance. Accordingly, the drive voltage of the Y1 device 58 and the Y2 device 64 is inevitably not higher than that at the time of 100% drive of the B light component, so that the drive voltage is low (about half of the saturation voltage of R is the saturation of B). Voltage).

  In general, the maximum driving voltage is determined by the LSI exposure rule of the display device. However, the driving voltages of the Y1 device 58 and the Y2 device 64 are lower than the maximum voltage. It is possible to reduce the cell gap. Therefore, in this modification, by shortening the cell gap of the Y1 device 58 and the Y2 device 64, the response time Rt2 is made shorter than the response time Rt1 of the G device 23, the R device 27, and the B device 31. Further, the total response time (Rt1ｔRt2) can be shortened. The total response time in this case is about 30% faster than Rt1 and Rt2, compared to about 50% of Rt1 and Rt2 when the above response times RT1 and RT2 are the same. Can be expected.

  Since the total response time is represented by (Rt1∩Rt2), even if the cell gaps of the G device 23, the R device 27, and the B device 31 are shortened to shorten the response time Rt1, Shorter. However, in this case, the saturation drive voltage of the R device 27 increases too much to saturate, and the brightness of the R signal becomes insufficient.

  Thus, the total response time (Rt1∩Rt2) is further shortened by making the response time Rt2 of the Y1 device 58 and the Y2 device 64 shorter than the response time Rt1 of the G device 23, the R device 27, and the B device 31. can do.

  The present invention can realize a projection display device capable of obtaining a more natural ultra-high-definition moving image and capable of reproducing an image with a very realistic presence. Further, the present invention can be applied to an integral (IP) 3D television as an application.

It is a block diagram of one embodiment of the optical system of the present invention. 2 is a timing chart showing a relationship between a display timing of each device of the embodiment of FIG. 1 and a projection image output obtained by multiplying a first light modulation and a second light modulation, and a switching signal. It is a block diagram of one embodiment of a projection type display device of the present invention. It is a block diagram which shows one Embodiment of the matrix conversion decoder in FIG. It is a block diagram of an example of the conventional optical system. It is a block diagram of an example of the conventional optical system which performs double modulation. It is a block diagram of an example of the conventional projection type display apparatus. It is explanatory drawing of 45 degree diagonal half pixel shifting.

Explanation of symbols

11 Lamp house 16 B / RG cross dichroic mirror 17 RG mirror 18 B mirror 19 R / G dichroic mirror 23 G device 27 R device 31 B device 32 RGB composite dichroic prism 35 1: 1 relay lens 51 90 degree phase control plate 52 PS Separate WG (wire grid)
53 Y1 field lens 54, 66 1/2 wavelength plate 55, 61 Analyzer 56 Y1WG (wire grid)
57 Y1 wave plate 58 Y1 device 59 Y2 field lens 60 Y2 aberration correction lens 62 Y2WG (wire grid)
63 Y2 wavelength plate 64 Y2 device 65 Y1 aberration correction lens 67 Y1 analyzer 68 PS composite WG (wire grid)
69 Y2 Analyzer 70 Y1Y2 Projection Lens 71 Switching Signal Generation Circuit 80 Projection Display Device 81 Super Hi-Vision Camera 82 Super Hi-Vision Recorder 83 Matrix Conversion Decoder 91 Inverse γ Correction Unit 92 Y1Y2 Creation Unit 93 Low-Pass Filter (LPF)
94 Maximum Value, Y1Y2 Calculation Unit 95 Coefficient and Luminance Signal Generation Unit 96 Multiplier 97 rgb Gamma Correction Unit 98 Y1 Gamma Correction Unit 99 Y2 Gamma Correction Unit 100 Optical System 101 Optical Illumination System Part 102 RGB Separation / Composite Projection System System 103 Y1Y2 image composition part 110 Y1 delay part

Claims (8)

Illumination light is separately supplied for each color signal of the three primary colors in units of 1 / T seconds obtained from two consecutive frames of the color signals of the three primary colors related to the frame image configured in units of 1 / (2T) seconds (T is a predetermined value). A modulation optical system that synthesizes each modulated primary color light obtained by light modulation, and outputs the first synthesized light as first modulated light;
The polarization plane of the first modulated light is alternately rotated 90 degrees and stopped every 1 / (2T) seconds, and the first modulated light is alternated every 1 / (2T) seconds. 90-degree phase control means for outputting as S-polarized light and P-polarized light,
Of the two consecutive frames, the S-polarized light output from the 90-degree phase control means with a first luminance signal generated from each of the first three primary colors in units of 1 / (2T) seconds of one frame A first luminance signal modulation optical system that optically modulates and outputs as a second modulated light;
Of the two consecutive frames, the P-polarized light output from the 90-degree phase control means with a second luminance signal generated from the color signals of the second three primary colors in the 1 / (2T) second unit of the other frame A second luminance signal modulation optical system that optically modulates and outputs as a third modulated light;
Light combining means for generating a second combined light by PS combining the second and third modulated light;
An optical system comprising: projection means for projecting the second combined light.   A first device for optically modulating the S-polarized light in the first luminance signal modulation optical system with the first luminance signal; and the P-polarized light in the second luminance signal modulation optical system as the second device. Each device response time Rt2 of the second device that optically modulates with the luminance signal is set shorter than each device response time Rt1 of the third device that performs optical modulation separately for each color signal of the three primary colors in the modulation optical system. The optical system according to claim 1.   The pixel of the first device that optically modulates the S-polarized light in the first luminance signal modulation optical system with the first luminance signal, and the P-polarized light in the second luminance signal modulation optical system. The pixel of the second device that modulates light with the luminance signal of 2 is arranged at a spatial position shifted by 45 degrees oblique half-pixels shifted by a half-pixel pitch in the horizontal and vertical directions. The optical system according to claim 1 or 2.   The color signals of the first three primary colors and the first luminance signal are signals relating to one image of the right eye image and the left eye image, and the color signals of the second three primary colors and the second luminance signal are used for the right eye. 4. The optical system according to claim 1, wherein the optical system is a signal related to the other of the image and the left-eye image. Based on the color signal of the first three primary colors of one frame out of two consecutive frames of the color signals of the three primary colors related to a frame image configured in units of 1 / (2T) seconds (T is a predetermined value), the band is limited. A first luminance signal that is not band-limited and generates a second luminance signal that is not band-limited based on the color signals of the second three primary colors of the other frame of the two frames. Signal generating means;
The band signals of the first and second three primary color signals are band-limited, and the maximum value for each pixel is obtained for each of the band-limited color signals of the first and second three primary colors, and the band-limited band is limited. Second signal generating means for generating band-limited third and fourth luminance signals based on the color signals of the first and second three primary colors;
Generating a color signal correction coefficient based on the maximum value for each pixel, generating a first display luminance signal based on the maximum value for each pixel and the third luminance signal, and The second display luminance signal is generated by shifting the luminance signal generated based on the maximum value for each pixel and the fourth luminance signal by 1 / (2T) seconds from the first display luminance signal. Third signal generating means for
By multiplying the color signal correction coefficient by the band-limited color signals of the first and second three primary colors, two consecutive primary color signals of the three primary colors related to the frame image formed in units of 1 / (2T) seconds are obtained. Fourth signal generating means for generating color signals of the three primary colors for display in units of 1 / T seconds obtained from the frame;
A modulation optical system that synthesizes the wavelengths of the modulated primary color lights obtained by separately modulating the illumination light for each of the three primary color signals for display and outputs the first synthesized light as the first modulated light; ,
The polarization plane of the first modulated light is alternately rotated 90 degrees and stopped every 1 / (2T) seconds, and the first modulated light is alternated every 1 / (2T) seconds. 90-degree phase control means for outputting as S-polarized light and P-polarized light,
A first luminance signal modulation optical system that optically modulates the S-polarized light output from the 90-degree phase control means with the first display luminance signal and outputs it as second modulated light;
A second luminance signal modulation optical system that optically modulates the P-polarized light output from the 90-degree phase control means with the second display luminance signal and outputs it as third modulated light;
Light combining means for generating a second combined light by PS combining the second and third modulated light;
And a projection means for projecting the second combined light.   A first device that optically modulates the S-polarized light in the first luminance signal modulation optical system with the first display luminance signal; and the P-polarized light in the second luminance signal modulation optical system. Each device response time Rt1 of the third device that optically modulates each device response time Rt2 of the second device that optically modulates with the display luminance signal of 2 for each color signal of the three primary colors in the modulation optical system. 6. The projection type display device according to claim 5, wherein the projection type display device is set to be shorter.   The pixel of the first device that optically modulates the S-polarized light in the first luminance signal modulation optical system with the first display luminance signal, and the P-polarized light in the second luminance signal modulation optical system. The pixels of the second device that are optically modulated with the second display luminance signal are arranged at a spatial position shifted by 45 degrees oblique half-pixels shifted by a half-pixel pitch from each other in the horizontal and vertical directions. The projection display device according to claim 5 or 6,   The first three primary color signals and the first display luminance signal are signals related to one of the right-eye image and the left-eye image, and the second three primary color signals and the second display luminance signal. 8. The projection display device according to claim 5, wherein a signal relating to the other image of the right-eye image and the left-eye image is used.

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