JP6601192B2 - Display device - Google Patents

Description

  The present invention relates to a display device.

  In recent years, there has been a demand for a display device that displays a high dynamic range (HDR) image. The dynamic range is the ratio between the brightest part and the darkest part. In relation to such a display device, for example, Patent Document 1 discloses a video display device that displays a high-contrast video.

  The video display device described in Patent Literature 1 includes an RGB projection display device that outputs light based on three primary color signals, and a Y projection display device that modulates light from an RGB projection display device based on a luminance signal. High contrast is realized using a display device.

JP 2007-310045 A

  In the technique described in Patent Literature 1, as described above, the Y projection display device modulates the luminance of light including RGB components. For this reason, in the projection display apparatus for RGB, since it is affected by the leakage light of the R modulation element, the G modulation element, or the B modulation element, the dynamic range is reduced. In order to facilitate understanding of this point, a case where only the R color is displayed will be described as an example. For example, when displaying only the R color, leakage light from the G modulation element and the B modulation element enters the Y projection display device in addition to the R light from the R modulation element. As a result, the dynamic range is narrowed.

  The present invention has been made in view of the above points, and an object thereof is to provide a display device capable of realizing display with a high dynamic range.

  A display device according to an aspect of the present invention includes a projection unit that emits light modulated according to a first video signal including three primary color signals, a screen, and an incident according to a second video signal including three primary color signals. From a liquid crystal panel that modulates and emits light; a panel unit that includes a polarizing plate that emits light in a predetermined polarization direction among the light emitted from the transmissive liquid crystal panel; and an input video signal composed of three primary color signals The first video signal for driving the projection unit and the second video signal for driving the transmissive liquid crystal panel are generated, and the first video signal and the second video signal are generated. A display control unit that generates a synchronization signal for synchronizing the screen, and the screen and the panel unit are arranged in the order of the screen and the panel unit in the order of travel of light emitted from the projection unit. Consists of Are, the light emitted from the projection unit is focused at a position farther than the liquid crystal panel as viewed from the projection unit.

  ADVANTAGE OF THE INVENTION According to this invention, the display apparatus which can implement | achieve the display in a high dynamic range can be provided.

1 is a perspective view illustrating an appearance of a display device according to a first embodiment. 1 is a configuration diagram illustrating an example of an internal configuration of a display device according to a first exemplary embodiment; FIG. 3 is a schematic diagram for explaining display by the display device according to the first embodiment; FIG. 3 is a diagram schematically illustrating a polarization state in the display device according to the first exemplary embodiment, where (a) illustrates a polarization state of light incident on the phase difference plate, and (b) illustrates a state of light emitted from the phase difference plate. A polarization state is shown, (c) shows the polarization state of the light inject | emitted from the panel part. It is a figure which shows typically the polarization state in the structure of a comparative example, (a) shows the polarization state of the light which injects into a phase difference plate, (b) shows the polarization state of the light inject | emitted from the phase difference plate. (C) shows the polarization state of the light emitted from the panel section. 1 is a block diagram showing a configuration of a display device according to a first exemplary embodiment. FIG. 2 is a block diagram showing a configuration of a signal processing unit according to the first exemplary embodiment; FIG. 3 is a block diagram illustrating an example of a configuration of a filter processing unit according to the first embodiment. 3 is a graph showing an example of gamma characteristics in the display device according to the first embodiment, where (a) shows the gamma characteristics of the input video signal, (b) shows the gamma characteristics of the transmissive liquid crystal panel, and (c) shows. The gamma characteristic of a projection part is shown. 3 is a graph showing an example of gamma characteristics in the display device according to the first embodiment, where (a) shows the gamma characteristics of the input video signal, (b) shows the gamma characteristics of the transmissive liquid crystal panel, and (c) shows. The gamma characteristic of a projection part is shown. 3 is a graph showing an example of gamma characteristics in the display device according to the first embodiment, where (a) shows the gamma characteristics of the input video signal, (b) shows the gamma characteristics of the transmissive liquid crystal panel, and (c) shows. The gamma characteristic of a projection part is shown. FIG. 4 is a schematic diagram illustrating an example of a configuration of a display device according to a second embodiment. FIG. 6 is a schematic diagram illustrating an example of a configuration of a display device according to a third embodiment. It is the table | surface which put together the characteristic of each liquid crystal panel of TN system, VA system, and IPS system. It is the table | surface summarized about the structural example in the case of comprising a display apparatus with the projection part which inject | emits a linearly polarized light. It is the table | surface summarized about the structural example in the case of comprising a display apparatus with the projection part which inject | emits circularly polarized light. It is the table | surface summarized about the structural example in the case of comprising a display apparatus with the projection part which inject | emits non-polarized light.

Embodiment 1
Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a perspective view showing the appearance of the display device 1. The display device 1 is a rear projection type projector (rear projector), and a panel unit 30 is provided on the front surface of the housing 10. More specifically, the display device 1 is a rear projector configured using LCOS (Liquid Crystal on Silicon) which is a reflective liquid crystal display element. FIG. 2 is a configuration diagram illustrating an example of the internal configuration of the housing 10 of the display device 1.

  As illustrated in FIG. 2, the display device 1 includes a projection unit 20, a panel unit 30, a screen 31, a mirror 40, and a display control unit 50. Here, in this Embodiment, the panel part 30 and the screen 31 are comprised integrally. The mirror 40 reflects the light emitted from the projection unit 20 toward the screen 31.

  The projection unit 20 generates projection light based on the video signal in order to project an image on the panel unit 30. More specifically, the projection unit 20 emits linearly polarized light corresponding to a first video signal, which will be described later, composed of three primary color signals. Here, the projection unit 20 emits focused light at a predetermined position farther from the projection unit 20 than the panel unit 30 on the optical axis. Hereinafter, the configuration of the projection unit 20 will be described.

  The projection unit 20 has a light source 201. The light source 201 is, for example, a lamp. The light emitted from the light source 201 is incident on the dichroic mirror 203 via an integrator 202 that emits the light emitted from the light source 201 with a uniform illuminance distribution in a plane perpendicular to the optical axis. The dichroic mirror 203 separates the incident light into R light having a red band component, G light having a green band component, and B light having a blue band component. The R light and G light separated by the dichroic mirror 203 enter the mirror 204. Further, the B light separated by the dichroic mirror 203 is incident on the mirror 205.

  The R light and G light separated by the dichroic mirror 203 are reflected by the mirror 204 and enter the dichroic mirror 206. The dichroic mirror 206 separates the incident R light and G light. The R light separated by the dichroic mirror 206 passes through the R field lens 207R and enters the R polarization control element 208R inclined at 45 °.

  The R polarization control element 208R is, for example, a wire grid type polarization beam splitter, and transmits P-polarized light and reflects S-polarized light. The P-polarized R light transmitted through the R polarization control element 208R is incident on the R display element 209R. The R display element 209 </ b> R is configured by LCOS, and modulates R light based on a video signal output from the display control unit 50 described later. The R light incident on the R display element 209R is reflected by the R display element 209R and returns to the R polarization control element 208R. At this time, the component modulated into S-polarized light by the R display element 209R is reflected toward the dichroic prism 210 by the R polarization control element 208R. The R light reflected in the direction of the dichroic prism 210 is incident on the first surface of the dichroic prism 210. On the other hand, the component not modulated by the R display element 209R is transmitted through the R polarization control element 208R and returns to the R field lens 207R.

  The G light separated by the dichroic mirror 206 passes through the G field lens 207G and enters the G polarization control element 208G inclined at 45 °. The G polarization control element 208G is, for example, a wire grid type polarization beam splitter, and transmits P-polarized light and reflects S-polarized light. The P-polarized G light transmitted through the G polarization control element 208G enters the G display element 209G. The G display element 209 </ b> G is configured by LCOS, and modulates the G light based on the video signal output from the display control unit 50. The G light incident on the G display element 209G is reflected by the G display element 209G and returns to the G polarization control element 208G. At this time, the component modulated into S-polarized light by the G display element 209G is reflected in the direction of the dichroic prism 210 by the G polarization control element 208G. The G light reflected in the direction of the dichroic prism 210 is incident on the second surface of the dichroic prism 210. On the other hand, the component not modulated by the G display element 209G is transmitted through the G polarization control element 208G and returns to the direction of the G field lens 207G.

  The B light separated by the dichroic mirror 203 is reflected by the mirror 205, passes through the B field lens 207B, and enters the B polarization control element 208B inclined at 45 °. The B polarization control element 208B is, for example, a wire grid type polarization beam splitter, and transmits P-polarized light and reflects S-polarized light. The P-polarized B light transmitted through the B polarization control element 208B is incident on the B display element 209B. The B display element 209 </ b> B is configured by LCOS, and modulates the B light based on the video signal output from the display control unit 50. The B light incident on the B display element 209B is reflected by the B display element 209B and returns to the B polarization control element 208B. At this time, the component modulated to S-polarized light by the B display element 209B is reflected by the B polarization control element 208B in the direction of the dichroic prism 210. The B light reflected toward the dichroic prism 210 is incident on the third surface of the dichroic prism 210. On the other hand, the component not modulated by the B display element 209B is transmitted through the B polarization control element 208B and returns to the B field lens 207B. In the following description, the R display element 209R, the G display element 209G, and the B display element 209B may be collectively referred to as a display element 209.

  The dichroic prism 210 emits S-polarized components of R light, G light, and B light incident from three directions toward the projection lens 212. Accordingly, linearly polarized light is emitted to the projection lens 212. The light emitted from the dichroic prism 210 enters the projection lens 212 via the phase difference plate 211. The phase difference plate 211 matches the polarization direction of the light emitted from the projection unit 20 with the polarization direction required as the incident light of the panel unit 30. In addition, the polarization direction requested | required as incident light of the panel part 30 is the direction which rotated the polarization direction which permeate | transmits the polarizing plate 302 mentioned later of the panel part 30 90 degrees, for example. The projection lens 212 projects the incident light onto the screen 31 via the mirror 40. Thus, the light emitted from the projection unit 20 is linearly polarized light. As described above, in the present embodiment, the linearly polarized light emitted from the projection unit 20 enters the screen 31 via the phase difference plate 211. However, even if the retardation plate 211 is not used, the retardation plate 211 is provided when the polarization direction of the light emitted from the projection unit 20 is already the polarization direction required as the incident light of the panel unit 30. It does not have to be. For example, the phase difference plate 211 is omitted, and the light emitted from the projection unit 20 is arbitrarily adjusted by rotating the projection unit 20 around the traveling direction of the light emitted from the projection unit 20 as an axis. The polarization direction may be the polarization direction required as the incident light of the panel unit 30.

Next, the screen 31 and the panel unit 30 will be described. The screen 31 is a screen having a characteristic of maintaining the polarization of incident light. As a screen having the property of maintaining polarized light, for example, a blue ocean screen manufactured by Nitto Resin Co., Ltd. can be used.
As shown in FIG. 2, the panel unit 30 includes a transmissive liquid crystal panel 301 having a predetermined resolution and a polarizing plate 302 having a size corresponding to the size of the display surface of the transmissive liquid crystal panel 301.

The screen 31, the transmissive liquid crystal panel 301, and the polarizing plate 302 are arranged in the order of the screen 31, the transmissive liquid crystal panel 301, and the polarizing plate 302 in the order of the traveling direction of the light emitted from the projection unit 20. . Moreover, as above-mentioned, in this Embodiment, these are comprised integrally. In the embodiment, the size of the screen 31 is a size corresponding to the size of the transmissive liquid crystal panel 301.
Here, as shown in FIG. 2, the polarizing plate is not necessarily provided on the light incident side from the projection unit 20 in the transmissive liquid crystal panel 301. This is because, as described above, since the light emitted from the projection unit 20 is linearly polarized light, it is not necessary to align the plane of polarization on one plane before the light enters the transmissive liquid crystal panel 301. .

  The transmissive liquid crystal panel 301 has a liquid crystal layer and a glass substrate (not shown), and modulates each light of the three primary colors emitted from the projection unit 20 and transmitted through the screen 31 according to a second video signal, which will be described later. Then change the polarization direction. Light that has passed through the transmissive liquid crystal panel 301 enters the polarizing plate 302. The polarizing plate 302 transmits light polarized in a predetermined direction. With such a configuration, the panel unit 30 controls the transmission amount of each of the R light, G light, and B light incident from the projection unit 20 for each pixel based on the second video signal, thereby performing display. Do. With such a configuration, each of the R light modulated by the R display element 209R, the G light modulated by the G display element 209G, and the B light modulated by the B display element 209B is displayed in the second image. Each is modulated in the panel unit 30 in accordance with the signal.

  FIG. 3 is a schematic diagram for explaining display by the display device 1. In FIG. 3, the reflection of the projection light by the mirror 40 is not shown for easy understanding. As shown by the broken line in FIG. 3, the projection unit 20 expands as the distance from the projection unit 20 increases, and on the optical axis is a predetermined position farther from the projection unit 20 than the panel unit 30 (on the focus plane shown in the figure). Projection light that is in focus at the position is emitted. That is, the focus plane of the light emitted from the projection unit 20 is at a position shifted from the panel unit 30 toward the viewpoint side. As shown in FIG. 3, an image is displayed on the screen 31 by the light emitted from the projection unit 20, but the focus surface of the light emitted from the projection unit 20 does not coincide with the screen 31. Then, a blurred image will be displayed. Here, as will be described later, the panel unit 30 is based on the second video signal subjected to the filter processing for canceling the influence of the blurred image on the screen 31 on the transmissive liquid crystal panel 301. In 301, the light incident through the screen 31 is modulated. With such a configuration, the panel unit 30 can display an image in which the influence of display blur on the screen 31 is eliminated. Note that the transmissive liquid crystal panel 301 only needs to have a resolution that can display an image in which a luminance change due to display blur on the screen 31 is eliminated. That is, the resolution may be any resolution that realizes display based on a video signal that has been subjected to filter processing described later. In the display device 1 having such a configuration, the user views an image by the pixels of the transmissive liquid crystal panel 301.

  Here, the polarization state in the display device 1 will be described. FIG. 4 is a diagram schematically illustrating a polarization state in the display device 1. FIG. 5 is a diagram schematically showing the polarization state in the configuration of the comparative example. Here, as a comparative example, a configuration in which the configuration of the projection unit 20 is replaced with DLP (Digital Light Processing) is assumed. That is, in the configuration according to the comparative example, it is assumed that the configuration upstream of the phase difference plate 211 in the projection unit 20 is realized by DLP. 4 and 5, (a) shows the polarization state of the light incident on the phase difference plate 211, (b) shows the polarization state of the light emitted from the phase difference plate 211, and (c) shows the polarization state. The polarization state of the light emitted from the panel unit 30 is shown. However, more specifically, FIG. 5B shows a polarization state after the light emitted from the phase difference plate 211 passes through the added polarizing plate.

  As described above, in the present embodiment, the light incident on the phase difference plate 211 is linearly polarized light (see FIG. 4A). In the present embodiment, the polarization direction is adjusted by the phase difference plate 211 (FIG. 4B). On the other hand, in the case of the configuration according to the comparative example, the light incident on the phase difference plate 211 is in a non-polarized state (see FIG. 5A). For this reason, in the case of the configuration according to the comparative example, it is necessary to provide a polarizing plate in front of the transmissive liquid crystal panel 301. By providing the polarizing plate in the previous stage of the transmissive liquid crystal panel 301 in this way, polarization required for incident light of the transmissive liquid crystal panel 301 is realized (see FIG. 5B). However, when the polarizing plate is provided in the front stage of the transmissive liquid crystal panel 301 in this way, the light amount is lost due to the polarizing plate. In addition, an increase in cost is caused by providing a polarizing plate corresponding to the size of the transmissive liquid crystal panel 301. The polarization state of the light emitted from the panel unit 30 is linearly polarized light in the polarization direction of the light transmitted by the polarizing plate 302. In the configuration shown in the comparative example, the phase difference plate 211 may be omitted.

  FIG. 6 is a block diagram illustrating a configuration of the display device 1. As illustrated in FIG. 6, the display control unit 50 includes a signal processing unit 500, a first synchronization unit 511, and a second synchronization unit 512. Each configuration of the display control unit 50 may be realized by software based on a program, or may be realized by any combination of hardware, firmware, and software. When realized by a program, for example, it is realized by executing a program stored in a memory (not shown) of the display control unit 50 by a CPU (Central Processing Unit) (not shown) of the display control unit 50.

  An input video signal and a synchronization signal are input to the signal processing unit 500. The input video signal input to the signal processing unit 500 may be transmitted to the display device 1 from another device, for example, or may be stored in a storage device (not shown) of the display device 1. Good. As the synchronization signal, for example, a synchronization signal generated by a synchronization signal generation circuit (not shown) is input to the signal processing unit 500.

  The input video signal is a video signal composed of RGB three primary color signals. The input video signal is, for example, a video signal having a higher bit than an 8-bit video signal that is generally used as a video signal. That is, for example, the input video signal is composed of an R-color 16-bit input video signal, a G-color 16-bit input video signal, and a B-color 16-bit input video signal. The input video signal is a video signal that has been subjected to gamma correction of a predetermined gamma value. As an example, the gamma value of the gamma characteristic of the input video signal is 2.2.

  The signal processing unit 500 generates a first video signal for performing display control by the projection unit 20 and a second video signal for performing display control by the panel unit 30 from the input video signal. That is, the signal processing unit 500 generates a first video signal and a second video signal from the input video signal, controls the projection unit 20 based on the first video signal, and based on the second video signal. Thus, the transmissive liquid crystal panel 301 is controlled. The generation of the first video signal and the second video signal by the signal processing unit 500 will be described later. The signal processing unit 500 performs processing in synchronization with the input synchronization signal.

  The signal processing unit 500 outputs the generated first video signal to the first synchronization unit 511. Further, the signal processing unit 500 outputs the generated second video signal to the second synchronization unit 512. A synchronization signal is also output to the first synchronization unit 511 and the second synchronization unit 512.

  The first video signal is supplied to the device driving unit 250 of the projection unit 20 via the first synchronization unit 511. Further, the second video signal is supplied to the panel drive unit 350 of the panel unit 30 via the second synchronization unit 512.

  Various signal processing (driving, etc.) is performed from when the video signal is input to the projection unit 20 and the transmissive liquid crystal panel 301 until the image is output. For this reason, a certain amount of time is required until the image is output. Here, since the time required for image output in the projection unit 20 and the time required for image output in the transmissive liquid crystal panel 301 are different, it is necessary to synchronize in order to align the image output timing of both. For this reason, the first synchronization unit 511 and the second synchronization unit 512 perform delay processing for adding optimal delays to the first video signal and the second video signal, respectively. Note that delay processing may be performed in either the first synchronization unit 511 or the second synchronization unit 512. The first synchronization unit 511 and the second synchronization unit 512 perform delay processing based on the synchronization signal. Then, the first synchronization unit 511 outputs the first video signal to the device driving unit 250 of the projection unit 20. Further, the second synchronization unit 512 outputs the second video signal to the panel drive unit 350 of the panel unit 30.

  The device driving unit 250 generates a drive signal for driving the display element 209 according to the first video signal, and drives the display element 209 with the drive signal. In addition, the panel driving unit 350 generates a drive signal for driving the transmissive liquid crystal panel 301 according to the second video signal, and drives the transmissive liquid crystal panel 301 by the drive signal.

  FIG. 7 is a block diagram illustrating a configuration of the signal processing unit 500. As illustrated in FIG. 7, the signal processing unit 500 includes a first LUT (Lookup Table) unit 501, a second LUT unit 502, and a filter processing unit 503. The first LUT unit 501 and the second LUT unit 502 are realized by a storage device such as a memory (not shown) of the display control unit 50, for example.

  The first LUT unit 501 generates a first video signal that adjusts the projection unit 20 to the first output characteristic from the input video signal that has been input, using a lookup table. In addition, the second LUT unit 502 generates a signal for adjusting the transmissive liquid crystal panel 301 to the second output characteristic from the input video signal that has been input, using a lookup table. However, the sum of the gamma value in the first output characteristic and the gamma value in the second output characteristic is equal to the gamma value of the input video signal. Here, a description will be given assuming that the gamma value of the input video signal is 2.2. In this case, the input video signal is correctly displayed when the gamma value of the output characteristic is 2.2. Therefore, it is necessary to realize a display device having a gamma value of 2.2 as an output characteristic for the output from the projection unit 20 and the output from the panel unit 30 as a whole. Therefore, for example, the first LUT unit 501 is configured as a table adjusted so that the output characteristic of the projection unit 20 is gamma 1.1. The second LUT unit 502 is configured as a table adjusted so that the output characteristic of the panel unit 30 is gamma 1.1. Such a table can be created, for example, by actually outputting in the projection unit 20 or the panel unit 30 and measuring the illuminance at that time with an illuminometer. As a result, the display device 1 can have output characteristics with a gamma value of 2.2 (= 1.1 + 1.1).

  The filter processing unit 503 performs a two-dimensional filter process for adjusting an image displayed on the transmissive liquid crystal panel 301 in accordance with an image that is not focused by the light emitted from the projection unit 20 irradiated on the screen 31. The second video signal is generated from the signal input from the second LUT unit 502. Note that the image formed by the light emitted from the projection unit 20 at the position of the screen 31 is not focused, and thus the image is blurred. The degree of blur is determined according to the MTF (Modulation Transfer Function) characteristic of the projection unit 20 and the distance of the screen 31 from the focus surface of the projection unit 20. More specifically, the MTF characteristic for the projection unit 20 refers to the MTF characteristic determined by the lens configuration of the projection unit 20 and the like. As described above, the focus plane of the light emitted from the projection unit 20 is at a position shifted to the viewpoint side from the panel unit 30. For this reason, the image on the screen 31 is blurred, and light corresponding to one pixel affects adjacent pixels. Here, the transmissive liquid crystal panel 301 is illuminated by an image formed on the screen 31. However, in the display device 1 according to the present embodiment, the image on the screen 31 is blurred because it is not focused on the screen 31 as described above. Images do not match. Therefore, the drive signal of the transmissive crystal panel 301 is adjusted so that the blurred state of the image formed on the screen 31 does not affect the transmissive liquid crystal panel 301. As a result, a second video signal that reduces the influence of the blurred image formed on the screen 31 is generated by the second LUT unit 502 and the filter processing unit 503, and a clear video is displayed on the panel unit 30.

  FIG. 8 is a block diagram illustrating an example of the configuration of the filter processing unit 503. As shown in FIG. 8, the filter processing unit 503 includes a first gamma correction unit 550, a line memory 551, a pixel buffer 552, a two-dimensional filter 553, a gain adjustment unit 554, a coefficient storage unit 555, A synthesis unit 556 and a second gamma correction unit 557 are included.

  When the video signal is input to the filter processing unit 503, it is supplied to the first gamma correction unit 550. Specifically, the output signal of the second LUT unit 502 is supplied to the first gamma correction unit 550. The video signal is sequentially input to the filter processing unit 503 in units of pixels from the upper end line to the lower end line of the image frame and from the left end to the right end of the image frame for each line.

  Note that the filter processing unit 503 performs each processing described later on the video signal independently for each of the RGB signals. In the following, unless otherwise specified, the video signal is assumed to be a video signal for each color of RGB.

  The first gamma correction unit 550 performs gamma correction processing on the supplied video signal, and converts the gradation characteristics of the video signal into linear characteristics. Thereby, image processing in the subsequent stage can be facilitated.

  The video signal output from the first gamma correction unit 550 is stored in the line memory 551. The line memory 551 includes N (N is a natural number) line memories each capable of storing pixel signals for one line, and reading and writing are performed by FIFO (First In, First Out) in the entire N line memories. In addition, for example, the line memory 551 has a write port and a read port, and a dual port type that can execute writing and reading in parallel is used.

  As an example, a video signal is stored line by line in each of the N line memories included in the line memory 551, and the first pixel of the next line is supplied to the line memory 551 when the line memory 551 is full. Think about the case. In this case, the position of each pixel stored in each of the N line memories is shifted by one pixel, the pixel is stored at the beginning of the first line memory, and the last pixel of each line memory is Stored at the beginning of the line memory. The last pixel of the last line memory is pushed out of the line memory and discarded, for example.

  The filter processing unit 503 reads out the pixels stored in the line memory 551 in units of predetermined blocks and stores them in the pixel buffer 552. For example, the pixel buffer 552 can store at least N × M pixels of N pixels in the vertical direction of the image and M (M is a natural number) pixels in the horizontal direction. The filter processing unit 503 reads out pixels from the line memory 551 in a block of N lines (pixels) × M pixels and stores the pixels in the pixel buffer 552.

  Pixels stored in a block of N lines × M pixels in the pixel buffer 552 are read out to the two-dimensional filter 553 and the gain adjustment unit 554. Although the details will be described later, the two-dimensional filter 553 and the gain adjustment unit 554 perform an operation on the pixel stored in the pixel buffer 552 using the coefficient stored in advance in the coefficient storage unit 555, and the pixel of one pixel Calculate the value.

  For example, when the pixel value for one pixel is output from the two-dimensional filter 553 and the gain adjustment unit 554, the filter processing unit 503 shifts the block of N lines × M pixels by one pixel in the line direction from the line memory 551. Are read out and stored in the pixel buffer 552. When the pixel value is output for the pixels for one line, the filter processing unit 503 performs the same processing for the next line and calculates the pixel value of each pixel.

  Next, processing in the above-described two-dimensional filter 553 and gain adjustment unit 554 will be described. A block of N lines × M pixels is supplied to the two-dimensional filter 553 and the gain adjustment unit 554 as described above.

  In the following, it is assumed that the MTF value at the position of the screen 31 is low, that is, the dispersion of light from the target pixel due to blur occurs concentrically around the target pixel, and the center of the block of N lines × M pixels The description will be made assuming that the pixel is selected as the target pixel. That is, in the following, it is assumed that the dispersed light for the target pixel is generated concentrically around the light of the target pixel.

The gain adjusting unit 554 estimates the first sum of the light intensities of the dispersed light from the target pixel around the target pixel. Then, the gain adjusting unit 554 adds the estimated first sum to the light intensity based on the pixel value of the target pixel to obtain the corrected light intensity P _c of the target pixel.

  That is, since the light intensity of the original light is attenuated by the amount of the dispersed light from the target pixel, the gain adjusting unit 554 obtains the first sum of the dispersed light from the target pixel to obtain the light of the original light. By adding to the intensity, the attenuation of the light intensity of the original light is compensated.

  Here, it is considered that the light intensity based on a pixel, that is, the light intensity of the light modulated from the light emitted from the light source 201 based on the pixel by the display element 209 corresponds to the pixel value of the pixel. Therefore, the gain adjustment unit 554 performs processing by regarding the pixel value of the target pixel as the light intensity of light based on the target pixel.

  Based on the result of the MTF calculation, the light intensity F at each position in the surface of the dispersed light from the target pixel is calculated.

The gain adjustment unit 554 obtains a first total sum B _{s of} each calculated light intensity F.

The light intensity P ₀ of the target pixel is a value obtained by subtracting the first total sum B _s of each light intensity F of the dispersed light from the ideal light intensity P _p . Therefore, the gain adjustment unit 554 _{calculates the} corrected light intensity P _c according to the following equation (1).
P _c = P ₀ + B _s (1)

In the above description, the first total sum B _s is obtained based on the light intensity F obtained using the inter-pixel distance between the target pixel and each pixel, but this is not limited to this example. For example, the first total sum B _s can be obtained as an integral value of the light intensity F when the distance from the target pixel is continuously taken.

  Next, processing in the two-dimensional filter 553 will be described. The two-dimensional filter 553 estimates the light intensity at the position of the target pixel of the dispersed light from each peripheral pixel located around the target pixel, and obtains the second total of the estimated light intensity. By subtracting the second sum from the light intensity based on the pixel value of the target pixel, the light intensity of the target pixel excluding the influence of the surrounding pixels can be obtained.

  In other words, dispersed light is generated by peripheral pixels around the target pixel as well as the target pixel, and the dispersed light from the peripheral pixel is superimposed on the light from the target pixel.

  Therefore, the two-dimensional filter 553 obtains a second total sum of the light intensity at the position of the target pixel of the dispersed light from the surrounding pixels. Then, the obtained second sum is subtracted from the light intensity of the pixel of interest in the subsequent synthesis unit 556, thereby eliminating the influence of the surrounding pixel on the pixel of interest.

  The light intensity of the dispersed light of the peripheral pixels at the position of the target pixel can be obtained using a light intensity distribution obtained with the position of the target pixel as the center. The data indicating the light intensity distribution is calculated in advance and stored in the coefficient storage unit 555 as described above.

More specifically, the two-dimensional filter 553 uses the coefficients stored in the coefficient storage unit 555, and for all the pixels i in the block other than the target pixel, at the position of the target pixel of the dispersed light of the pixel. The light intensity P _i is obtained. Then, the two-dimensional filter 553 obtains a second sum B _x of the light intensity P _i obtained for each pixel i.

The gain adjustment unit 554 inputs the corrected light intensity P _c calculated by the above-described equation (1) to the addition input terminal of the synthesis unit 556. Further, the two-dimensional filter 553 inputs the calculated second total sum B _x to the subtraction input terminal of the synthesis unit 556. The synthesizing unit 556 subtracts the sum B _x from the corrected light intensity P _c to calculate an ideal light intensity P _p of light from the target pixel.

That is, the light intensity P ₀ of the light by the target pixel is expressed by the following equation using the ideal light intensity P _p of the light by the target pixel and the above-described first sum B _s and second sum B _x. It can be represented by (2).
_{P 0 = P p -B s +} B x ... (2)

Therefore, the ideal light intensity P _p by the light of the pixel of interest is expressed by the following equation (3).
P _p = P ₀ + B _s −B _x (3)

Here, P ₀ + B _s = P _{c according} to the above equation (1). Therefore, by subtracting the sum B _x output from the two-dimensional filter 553 from the corrected light intensity P _c output from the gain adjustment unit 554 in the combining unit 556, the ideal light intensity P due to the light of the pixel of interest. _p can be obtained.

The combining unit 556 outputs a pixel having a pixel value corresponding to the light having the light intensity P _p obtained as described above. The pixels output from the combining unit 556 are supplied to the second gamma correction unit 557. The second gamma correction unit 557 performs reverse correction of the correction in the first gamma correction unit 550 on the supplied pixel, and outputs the gradation characteristic as a non-linear characteristic. The pixel output from the second gamma correction unit 557 is output from the filter processing unit 503 as a second video signal.

  With the above configuration, the signal processing unit 500 generates the following first video signal and second video signal from the input video signal. That is, the first video signal is an output signal of the first LUT unit 501 for the input video signal. The second video signal is an output signal of the second LUT unit 502 for the input video signal, and is a signal that has been subjected to two-dimensional filter processing by the filter processing unit 503. More specifically, as shown in FIG. 7, the input video signal input to the signal processing unit 500 is sent to the first LUT unit 501 and the second LUT unit 502. Then, the first LUT unit 501 generates a first video signal. The second LUT unit 502 outputs the output video signal to the filter processing unit 503. The filter processing unit 503 generates a second video signal by filter processing. At this time, a first video signal or a second video signal is generated for each of RGB signals in the input video signal. That is, an R first video signal and an R second video signal are generated from the R input video signal. A G first video signal and a G second video signal are generated from the G input video signal. Further, a B first video signal and a B second video signal are generated from the B input video signal. Here, in the generation of the first video signal and the second video signal, as described above, RGB may be processed independently by the LUT, and the bits of the first video signal and the second video signal may be processed. The number can be any number of bits. For example, when the input video signal is 16 bits, the first video signal and the second video signal may be 16-bit video signals, or the upper 8-bit signal on the MSB (most significant bit) side It may be supplied as a first video signal, and a lower 8-bit signal on the least significant bit (LSB) side may be supplied as a second video signal.

  Here, the gamma value realized by the LUT will be further described. In the present embodiment, as described above, since the gamma characteristic of the input video signal is divided into two, the first output characteristic and the second output characteristic are close to linear. For this reason, the reproducibility of dark part gradation is improved. For example, when the gamma value of the gamma characteristic of the input video signal is defined by 2.2, the first output characteristic and the second output characteristic are 1.1 when simply divided as described above. When the gamma value is 2.2, the value of 1 in 8-bit input is about 0.000005 for white (value of 255 in 8-bit input) in terms of brightness. Therefore, unless the contrast on the display surface can be displayed at 2,000,000: 1, the brightness indicated by the value of 1 (8 bits) in the theoretical gamma curve cannot be reproduced. On the other hand, when the gamma value is 1.1, the value of 1 in 8-bit input is about 0.0023 with respect to white (255 value in 8-bit input), and the contrast on the display surface is 440. : 1 can be displayed. Therefore, the contrast performance required for the transmissive liquid crystal panel 301 can be suppressed. That is, an ideal gamma characteristic can be obtained by combining the transmissive liquid crystal panel 301 and the projection unit 20 that are relatively easily available.

  Further, as described above, when the first video signal and the second video signal are generated from the input video signal, since RGB is independent, it is easy to realize gamma adjustment. For example, as described in Japanese Patent Application Laid-Open No. 2007-310045, when the luminance is modulated, a Y (luminance) signal is generated from the RGB of the input video signal. Not easy to keep. This is because one dimension is added to generate the Y signal, and conversion from the three-dimensional RGB to the four-dimensional RGBY is required. In contrast, in the present embodiment, the RGB signal of the input video signal is divided into the RGB signal of the first video signal and the RGB signal of the second video signal, so that each color is processed independently. It is easy to maintain gradation. Further, since the conversion is from RGB three-dimensional to RGB three-dimensional, the generation of the first video signal and the second video signal can be realized relatively easily.

  Furthermore, according to the display device 1 according to the present embodiment, it is possible to display an input video signal having a large gamma value of 2.2 or more as the gamma characteristic. This is due to the following reason. For example, when the gamma characteristic is 2.2, a value obtained by raising the input video signal to the power of 2.2 has a specified luminance (brightness). For example, the value of 1 of the 8-bit signal is 1/255 = 0.39221... But the luminance (brightness) is (1/255) ^ 2.2 = 0.00000000077. Therefore, when the gamma characteristic is set to a value larger than 2.2, the luminance is smaller (that is, darker) than that when the input video signal is the same as that of the second power. For this reason, as the gamma characteristic of the input video signal becomes larger than the power of 2.2, it becomes a region where it is difficult to display the specified luminance on the conventional display. On the other hand, in the present embodiment, since the multiplication of the output values of the projection unit 20 and the transmissive liquid crystal panel 301 is the final output value, it can be realized relatively easily. Thus, according to the display device 1, it is possible to display an input video signal having a large gamma value of 2.2 or more as the gamma characteristic. As the gamma value of the gamma characteristic of the input video signal is larger, the dark portion gradation is maintained, so according to the display device 1 according to the present embodiment, the error when quantizing the image data is expressed in the floating-point format. By making it image data, it also contributes to reducing the quantization error of dark part gradation.

  In the above description, as an example, the gamma value of the first output characteristic (that is, the gamma value of the output characteristic of the projection unit 20) is 1.1, and the gamma value of the second output characteristic (that is, the output of the panel unit 30). The characteristic gamma value) is 1.1, but is not limited thereto. That is, the sum of the gamma value in the first output characteristic and the gamma value in the second output characteristic may be equal to the gamma value of the input video signal. 9 to 11 are graphs showing an example of the relationship (gamma characteristic) between an input value that is an input video signal or a video signal and an optical output in the display device 1 according to the present embodiment. 9 to 11, (a) shows the gamma characteristic of the input video signal, (b) shows the gamma characteristic of the transmissive liquid crystal panel 301, and (c) shows the gamma characteristic of the projection unit 20. 9 to 11, the horizontal axis represents an input video signal or an input value that is a video signal, and the vertical axis represents an optical output value. That is, in (b) of FIGS. 9 to 11, the horizontal axis indicates the input value that is the second video signal output from the second LUT unit 502, and the vertical axis indicates the light output value of the transmissive liquid crystal panel 301. Show. 9C, the horizontal axis indicates the input value that is the first video signal output from the first LUT unit 501, and the vertical axis indicates the light output value of the projection unit 20.

  FIG. 9 shows the first output characteristic (output characteristic of the projection unit 20) and the second output characteristic when the gamma value of the gamma characteristic of the input video signal described in the above description is defined by 2.2. In this example, the gamma value of (output characteristics of the transmissive liquid crystal panel 301) is 1.1.

  FIG. 10 shows that when the gamma value of the gamma characteristic of the input video signal is defined by 3.2, the gamma value of the first output characteristic (output characteristic of the projection unit 20) is 2.2, This is an example in which the gamma value of the output characteristic (the output characteristic of the transmissive liquid crystal panel 301) is 1. Here, it is assumed that the projection unit 20 has a higher contrast than the transmissive liquid crystal panel 301. Thus, the gamma value in the higher contrast output characteristics of the projection unit 20 and the transmissive liquid crystal panel 301 is the gamma value in the lower contrast output characteristics of the projection unit 20 and the transmissive liquid crystal panel 301. Larger adjustments may be made. Thereby, the contrast of the entire display device 1 can be improved.

  FIG. 11 shows an example in which the modulation of the transmissive liquid crystal panel 301 is limited to a predetermined range on the dark side. In the example shown in FIG. 11, when the gamma value of the gamma characteristic of the input video signal is defined by 2.2, the gamma value of the first output characteristic (output characteristic of the projection unit 20) is 2.2 ( However, the gamma value is 1.2) when the input is 0.25 or less, and the gamma value of the second output characteristic (the output characteristic of the transmissive liquid crystal panel 301) is 1. In the second output characteristic, when the input value is 0.25 or more, the light output amount is uniformly maximized. As described above, the output characteristics of the transmissive liquid crystal panel 301 may be fixed to the maximum value when the input value is equal to or greater than a predetermined value. As a result, all the gradations of the transmissive liquid crystal panel 301 can be assigned to a gamma region having an input value of 0.25 or less, and there is an advantage that gradations on the dark side can be expressed with finer gradations. .

  The display device 1 according to the present embodiment has been described above. In the display device 1, as described above, light that is modulated for each of RGB by the projection unit 20 is output, and each of the RGB light that is emitted from the projection unit 20 is further modulated by the transmissive liquid crystal panel 301. Thereby, the influence of leaking light can be suppressed and the contrast can be improved. Here, a case where only the R color is displayed will be described as an example with a comparative example. For example, as a comparative example, assuming a liquid crystal display in which the first modulation is performed by control of the backlight and the second modulation is performed on the light of the backlight, G in the second modulation device is assumed. The leakage of light and B light causes a decrease in contrast. Further, due to the influence of leakage light of G light and B light, a color shifted from the original color, that is, a color shifted to a point in the white direction in the chromaticity diagram is displayed. Further, for example, as described in Japanese Patent Application Laid-Open No. 2007-310045 as a comparative example, even when the luminance is modulated by the second modulation device, it is improved as compared with the comparative example of the liquid crystal display. A similar situation occurs. On the other hand, in the display device 1 according to the present embodiment, the R light, the G light, and the B light are each modulated in a double manner, so that leakage light can be suppressed. For this reason, it is possible to suppress a decrease in contrast and color misregistration, and in particular, it is possible to expand the dynamic range even for chromatic colors.

Embodiment 2
Next, a second embodiment of the present invention will be described. In the first embodiment, the display device in which the screen 31 and the panel unit 30 are integrally formed has been described. However, the screen 31 and the panel unit 30 may not necessarily be integrally formed. In the second embodiment, the screen 31 and the panel unit 30 are arranged apart from each other. FIG. 12 is a schematic diagram illustrating an example of the configuration of the display device 2 according to the second embodiment. In FIG. 12, the reflection of the projection light by the mirror 40 is not shown for easy understanding.

The display device 2 is different only in the positional relationship between the screen 31 and the panel unit 30, and the other configurations are the same as those of the display device 1 according to the first embodiment. Therefore, the screen 31, the transmissive liquid crystal panel 301, and the polarizing plate 302 are configured in the order of the screen 31, the transmissive liquid crystal panel 301, and the polarizing plate 302 in the order in which the light emitted from the projection unit 20 travels. ing. As shown in FIG. 12, in the display device 2 according to the present embodiment, the screen 31 has a predetermined distance from the panel unit 30 in the direction opposite to the traveling direction of the light emitted from the projection unit 20. Just placed apart. In the display device 2, the panel unit 30 may be configured to be movable in the optical axis direction.
Also in the display device 2 having such a configuration, the dynamic range can be improved as in the first embodiment.

Embodiment 3
Next, a third embodiment of the present invention will be described. When the screen 31 and the panel unit 30 are separated from each other as in the display device 2 according to the second embodiment, the display area of the screen 31 and the display area of the panel unit 30 depend on the position of the user's viewpoint. There is a risk of misalignment and the appearance of a double image. Therefore, in the present embodiment, the projection unit 20 emits light within a projection range corresponding to the position of the viewpoint. FIG. 13 is a schematic diagram illustrating an example of the configuration of the display device 3 according to the third embodiment. In FIG. 13, the reflection of the projection light by the mirror 40 is not shown for easy understanding.

  As shown in FIG. 13, in the display device 3 according to the present embodiment, the screen 31 is opposite to the traveling direction of the light emitted from the projection unit 20, as in the display device 2 according to the second embodiment. In the direction, the panel unit 30 is arranged away from the panel unit 30 by a predetermined distance. Here, the projection unit 20 acquires viewpoint position information, and realizes a projection range corresponding to the viewpoint position (a position where the user views the panel unit 30). Note that the viewpoint position information may be acquired by an arbitrary method. For example, it may be input to the display device 3 according to an operation instruction from the user, or may be received from another device. Specifically, the projection unit 20 determines the range of the field of view on the screen 31 when the user views the screen 31 through the panel unit 30 from the viewpoint position indicated by the viewpoint position information according to the first video signal. Set as the projection range of modulated linearly polarized light. For this reason, the size of the screen 31 covers a projection range corresponding to each of the viewpoint positions that can be set. Although the projection range of the projection unit 20 of the display device 3 varies depending on the viewpoint position, the projection ranges are in the same magnification relationship. Moreover, in order to project the light of the set projection range, the projection unit 20 adjusts the projection range by driving, for example, the projection lens 212 or an optical mechanism (not shown). In the example illustrated in FIG. 13, the projection unit 20 projects light in the projection range 60 when the viewpoint position is the viewpoint position A, and projects light in the projection range 61 when the viewpoint position is the viewpoint position B. Project. Note that the projection ranges 60 and 61 shown in FIG. 13 indicate the projection ranges on the screen 31 by the projection unit 20.

  Although the third embodiment has been described above, the other configuration of the display device 3 according to the third embodiment is the same as that of the other embodiments described above. Therefore, the screen 31, the transmissive liquid crystal panel 301, and the polarizing plate 302 are configured in the order of the screen 31, the transmissive liquid crystal panel 301, and the polarizing plate 302 in the order in which the light emitted from the projection unit 20 travels. ing. According to the display device 3 according to the present embodiment, it is possible to suppress the appearance of a double image when the panel unit 30 and the screen 31 are arranged apart from each other.

  Note that the present invention is not limited to the above-described embodiment, and can be changed as appropriate without departing from the spirit of the present invention. For example, in the above embodiment, the input video signal, the first video signal, and the second video signal have been described as RGB signals, but may be signals expressed in other color spaces. For example, a signal represented by a luminance signal and two color difference signals such as a YPbPr signal may be used.

  In the above embodiment, the projection unit 20 emits linearly polarized light. However, the projection unit 20 emits light other than the linearly polarized light that is modulated according to the first video signal. It may be replaced with a part. That is, for example, a projection unit that emits circularly polarized light modulated according to the first video signal described above, or a projection unit that emits non-polarized light modulated according to the first video signal described above is used. May be. Further, the driving method of the transmissive liquid crystal panel 301 can be any method. For example, the transmissive liquid crystal panel 301 may be a TN (Twisted Nematic) type liquid crystal panel, a VA (Virtical Alignment) type liquid crystal panel, or an IPS (In-Place-Switching) type. It may be a liquid crystal panel.

  Here, TN, VA, and IPS liquid crystal panels that control the polarization direction of incident light by the voltage applied to the liquid crystal will be described. FIG. 14 is a table summarizing the characteristics of each of the TN, VA, and IPS liquid crystal panels. Here, as an example of the TN method, when the voltage applied to the liquid crystal panel is maximum, the light is blocked and the screen is displayed in black, and when the voltage is not applied to the liquid crystal panel, the screen is displayed in white. Show. On the other hand, in the VA method and the IPS method, when no voltage is applied to the liquid crystal panel, the light is blocked and the screen is displayed in black, and when the voltage applied to the liquid crystal panel is maximum, the screen is displayed in white. The type is shown as an example.

  Further, comparing the contrast of each method, the VA method has the largest contrast, and the TN method has the next highest contrast. For this reason, the IPS system is the most inferior in contrast performance among these three systems. Further, when comparing the viewing angle of each method, the IPS method has the largest viewing angle, and the VA method has the next largest viewing angle. For this reason, the TN system is the most inferior in viewing angle performance among these three systems. In FIG. 14, the numbers in the columns for contrast and viewing angle indicate that the smaller the value, the better.

  Hereinafter, a configuration example of a display device when the above-described transmission type liquid crystal panel is used as the transmission type liquid crystal panel 301 will be specifically described.

  Here, the polarization direction of the polarizing plate 302 on the light emission side of the liquid crystal panel, that is, the transmission axis of the polarizing plate 302 is used as a reference. Here, when a TN type liquid crystal panel in which the phase of light changes by 1 / 2λ without using a voltage is applied to the liquid crystal panel, the polarization direction of light transmitted through the liquid crystal panel is incident on the liquid crystal panel. It is orthogonal to the polarization direction of the light. Therefore, when this type of TN liquid crystal panel is used, the polarization direction of light incident on the liquid crystal panel is required to be rotated by 90 ° with respect to the reference.

  In the case of the VA method and IPS method in which the phase of light changes by 1 / 2λ with the maximum voltage applied to the liquid crystal panel, the polarization direction of the light incident on the liquid crystal panel is rotated by 90 ° with respect to the reference. It is required to do. On the other hand, there is no change in the polarization state when no voltage is applied to the liquid crystal panel.

  Therefore, even if a liquid crystal panel of any of TN, VA, and IPS as described above is used, the polarization direction of the light emitted from the projection unit 20 may be a direction orthogonal to the reference.

  FIG. 15 is a table summarizing a configuration example in the case where the display device is configured by the projection unit 20 that emits linearly polarized light as shown in the embodiment. As described above, the polarization direction of light incident on the liquid crystal panel is required to be rotated by 90 ° with respect to the reference. Therefore, as shown in configuration examples 1 and 4 in FIG. 15, when the polarization direction of the light emitted from the projection unit 20 is the same as the reference, the slow axis or the fast axis is relative to the polarization plane of the incident light. A 1 / 2λ plate, which is a retardation plate arranged at an azimuth angle of 90 °, is inserted between the projection unit 20 and the transmissive liquid crystal panel 301 so that the polarization direction is orthogonal to the reference. The retardation plate 211 corresponds to such a retardation plate. As shown in configuration examples 2 and 3 in FIG. 15, when the polarization direction of the emitted light from the projection unit 20 is orthogonal to the reference, it is necessary to change the polarization direction of the emitted light from the projection unit 20. Therefore, it is not necessary to insert a retardation plate.

  FIG. 16 is a table summarizing configuration examples in the case where the display device is configured by a projection unit that emits circularly polarized light. In the case where the above-described display device is configured using a projection unit in which the emitted light is circularly polarized light instead of the projection unit 20 that emits linearly polarized light, as shown in the configuration examples 5 and 6 in FIG. A quarter-wave plate, which is a retardation plate whose slow axis or fast axis is arranged at an azimuth angle of 45 degrees, is inserted between the projection unit 20 and the transmissive liquid crystal panel 301, and based on the polarization direction. Make them orthogonal. In FIG. 16, Configuration Example 5 shows a configuration example when the projection unit emits counterclockwise or clockwise circularly polarized light when the transmission axis of the polarizing plate is in the vertical direction. Configuration example 6 illustrates a configuration example when the projection unit emits counterclockwise or clockwise circularly polarized light when the transmission axis of the polarizing plate is in the horizontal direction. In any configuration example, the polarization direction of the light incident on the liquid crystal panel can be made orthogonal to the reference by rotating and adjusting the optical axis of the phase difference plate according to the rotation direction of the circularly polarized light.

  FIG. 17 is a table summarizing a configuration example in the case where the display device is configured by a projection unit that emits non-polarized light. When the above-described display device is configured using a projection unit that emits non-polarized light instead of the projection unit 20 that emits linearly polarized light, as shown in Configuration Examples 7 and 8 in FIG. A display device is configured. That is, in this display device, a polarizing plate having a transmission axis perpendicular to the transmission axis of the polarizing plate 302 on the light emission side of the liquid crystal panel is inserted between the projection unit 20 and the transmissive liquid crystal panel 301, and The polarization direction of light incident on the transmissive liquid crystal panel 301 is orthogonal to the reference. In this display device, the retardation plate is not always necessary.

  As described above, various types of projection units can be employed. FIGS. 15 to 17 show, as an example, only the case where the polarization direction of the polarizing plate 302 on the light emission side of the liquid crystal panel is the horizontal direction or the vertical direction, but it rotates in other directions. However, it goes without saying that the display device can be appropriately configured.

  As described above, various types of panels including the TN mode, the VA mode, and the IPS mode can be adopted as the mode of the transmissive liquid crystal panel. In addition, when the person who watches the image on the display device, that is, the user, sees the liquid crystal panel, it is preferable to use the IPS method in which the viewing angle is superior to the TN method and the VA method. Therefore, in the above embodiment, a VA liquid crystal panel is preferably used as the transmissive liquid crystal panel 301.

  In addition, the liquid crystal panel having a configuration that transmits light when the polarization direction is rotated by 90 ° by the liquid crystal has been described as an example. However, for example, a configuration that blocks light when the polarization direction is rotated by 90 ° by the liquid crystal is provided. When a liquid crystal panel is used, the polarization direction of the light emitted from the projection unit may coincide with the reference. Thus, the display device may be configured so that light having a polarization direction required as incident light of the liquid crystal panel is incident on the liquid crystal panel.

1, 2, 3 Display device 10 Housing 20 Projection unit 30 Panel unit 31 Screens 40, 204, 205 Mirror 50 Display control unit 201 Light source 202 Integrator 203, 206 Dichroic mirror 207B B field lens 207G G field lens 207RR Field lens 208B B polarization control element 208G G polarization control element 208R R polarization control element 209B B display element 209G G display element 209R R display element 210 Dichroic prism 211 Phase difference plate 212 Projection lens 250 Device driver 301 Transmission type liquid crystal panel 302 Polarizing plate 350 Panel drive unit 500 Signal processing unit 501 First LUT unit 502 Second LUT unit 503 Filter processing unit 511 First synchronization unit 512 Second synchronization unit 550 First gamma correction 551 a line memory 552 pixel buffer 553 the two-dimensional filter 554 gain adjuster 555 coefficient storage unit 556 combining unit 557 the second gamma correction unit

Claims (9)

A projection unit for emitting light modulated in accordance with a first video signal composed of three primary color signals;
Screen,
A transmissive liquid crystal panel that modulates and emits incident light according to a second video signal composed of three primary color signals, and a polarizing plate that emits light having a predetermined polarization direction out of the light emitted from the transmissive liquid crystal panel. A panel section comprising:
The first video signal for driving the projection unit and the second video signal for driving the transmissive liquid crystal panel are generated from an input video signal consisting of three primary color signals, and the first video A display control unit for generating a synchronization signal for synchronizing the signal and the second video signal,
The screen and the panel unit are arranged in the order of the screen and the panel unit in the order of the traveling direction of light emitted from the projection unit,
The light emitted from the projection unit is focused at a position farther from the panel unit when viewed from the projection unit. The display device according to claim 1, wherein the screen and the panel unit are integrally formed. The display device according to claim 1, wherein the screen is disposed at a predetermined distance from the panel unit. The display device according to claim 1, wherein light emitted from the projection unit is linearly polarized light. A retardation plate;
The light emitted from the projection unit is linearly polarized light or circularly polarized light, and the light emitted from the projection unit is incident on the transmissive liquid crystal panel through the retardation plate. The display device according to claim 1. On the incident side of the transmissive liquid crystal panel, there is an incident side polarizing plate that is a polarizing plate different from the polarizing plate,
The light emitted from the projection unit is non-polarized light, and the light emitted from the projection unit is incident on the transmissive liquid crystal panel via the incident-side polarizing plate. The display device according to claim 1. The display control unit includes a first look-up table unit that adjusts an output characteristic of the projection unit to a first output characteristic, and a second that adjusts an output characteristic of the transmissive liquid crystal panel to a second output characteristic. A lookup table section and a filter processing section;
The first look-up table unit converts the inputted input video signal to the first video signal and outputs the first video signal,
The second look-up table unit converts the input video signal input to the second video signal and outputs the second video signal,
The filter processing unit performs two-dimensional filter processing on the signal input from the second look-up table unit, and reduces the influence of light projected on the screen from the projection unit on the transmissive liquid crystal panel. Converting and outputting the second video signal;
7. The display device according to claim 1, wherein a sum of a gamma value in the first output characteristic and a gamma value in the second output characteristic is equal to the gamma value of the input video signal. When comparing the output characteristics of the projection unit and the transmissive liquid crystal panel, the gamma value in one output characteristic showing a higher contrast is compared when comparing the output characteristics of the projection unit and the transmissive liquid crystal panel. The display device according to claim 7, wherein the display device is adjusted to be larger than a gamma value in the other output characteristic exhibiting a lower contrast. The display device according to claim 7, wherein the output characteristics of the transmissive liquid crystal panel are such that when the input value of the second video signal is equal to or greater than a predetermined value, the light output is a maximum value.

Images