JP2008032800A - Projector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a projector capable of achieving improvement in the blur of a moving picture with comparatively simpler constitution than the conventional one. <P>SOLUTION: The projector which projects an image is equipped with: a device for display which emits image light expressing the image; a projection optical system which projects the image light emitted from the device for display; an image light restricting device which is arranged in front of the surface of the projection optical system on which the image light is made incident, and restricts the emission of a part of the image light made incident from the device for display to the projection optical system; and a device driving part which drives the device for display and the image light restricting device. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a technique for improving blurring of a moving image that occurs when a moving image is displayed by a projector.

  Projectors using a liquid crystal panel as a display device (also referred to as “liquid crystal projector”) are becoming popular. However, when displaying a moving image with a liquid crystal projector, there is a problem that blurring or ghosting of the outline of the object occurs according to the moving speed of the object in the moving image. Hereinafter, the blur and ghost of the outline of these objects are collectively referred to as “moving image blur”.

  The occurrence of the moving image blur as described above is considered to be mainly caused by the following problems.

  First, a voltage (electric field) corresponding to image data (gradation data) applied to each pixel (hereinafter referred to as “liquid crystal pixel”) of the liquid crystal panel is applied to the pixel. The response speed until the desired light transmittance is reached is low. For example, since the response time of a twisted nematic liquid crystal (hereinafter referred to as “TN type”), which is one of typical liquid crystals, is usually several ms or more for a frame period of about 16.7 ms. In some cases, the change in light transmittance in each liquid crystal pixel cannot sufficiently follow the change in the applied voltage, resulting in motion blur.

  Second, even if the response speed of the liquid crystal is improved, each liquid crystal pixel is a hold-type electro-optical element. For this reason, the characteristic of the signal frequency represented by the image data given to each liquid crystal pixel has a low-pass type time-frequency characteristic in which the response characteristic in the high frequency is reduced, and accordingly, the displayed display image is visually recognized. As a result, there is a case where moving image blur occurs.

  Thus, for example, an example described in Patent Document 1 is disclosed as a liquid crystal panel that solves the above problem.

  This liquid crystal panel scans liquid crystal cells arranged in a matrix in the column direction (horizontal direction) and row direction (vertical direction), writes and displays video signals, and scans in the row direction for writing video signals. On the other hand, the scanning in the row direction is delayed for a predetermined time, and a predetermined fixed level signal is written to all the liquid crystal cells in the row specified by the scanning in the row direction at a predetermined time within the horizontal blanking period. To display.

JP 2006-106689 A

  However, in the liquid crystal panel of Patent Document 1 above, in order to improve blurring of moving images, vertical scanning is delayed by a predetermined time, and specified by vertical scanning at a predetermined time within a horizontal blanking period. There is a problem that a complicated control circuit for writing a predetermined fixed level signal to all liquid crystal cells in a row needs to be provided in the liquid crystal panel, and the manufacturing cost of the liquid crystal panel is low. As a result, the manufacturing cost of a projector using the projector increases as a result.

  Note that the moving image blur caused by the second problem occurs not only in the liquid crystal panel but also in the case where a display device in which each pixel is configured by a hold type electro-optical element is used. Although the improvement can be achieved by the same control as in FIG. 1, it is necessary to provide a complicated control circuit in the display device, and there is a problem that the manufacturing cost of the projector using the same increases. In common.

  The present invention has been made to solve the above-described problems in the prior art, and an object of the present invention is to provide a projector capable of improving motion blur with a relatively simple configuration compared to the conventional art.

In order to solve at least a part of the above-described problems, a projector according to the present invention includes:
A projector for projecting an image,
A display device for emitting image light representing the image;
A projection optical system that projects image light emitted from the display device;
An image light limiting device that is disposed in front of the surface on which the image light of the projection optical system is incident, and that restricts emission of the part of the image light incident from the display device to the projection optical system;
A device driver for driving the display device and the image light limiting device;
It is characterized by providing.

  In the projector described above, the image light limiting device can restrict the emission of a part of the image light emitted from the display device and incident on the projection optical system. It is possible to provide a projector capable of improving the above.

In the above projector,
The display device has a plurality of pixels configured by arranging hold-type electro-optical elements in a matrix, and each pixel is scanned in the column direction and the row direction in order to represent the image. Emit light,
The image light limiting device is an image corresponding to a scan row including at least pixels that are scanned along the column direction in the display device, out of the image light emitted and incident from the display device. It is preferable to limit the emission of light to the projection optical system.

  In this case, at least before the scanning is executed, the image light corresponding to the scanning row including the pixel that is scanned along the column direction is limited to the emission to the projection optical system. After effectively eliminating the visual influence of the image represented by the emitted image light, the image represented by the image light emitted after scanning can be displayed, so it is easy to improve motion blur. It is possible to plan.

  Here, the image light limiting device corresponds to at least one row of image light out of the incident image light emitted from the display device, and the plurality of image light limiting devices arranged along the row direction. It is preferable that the image light restriction region corresponding to the image light corresponding to the scanning row has a region and restricts the emission of the corresponding image light.

  In this way, an image light limiting device can be easily configured.

  Further, the plurality of restricted areas including the image light restricted area corresponding to the scanning row may restrict the emission of the corresponding image light.

  In this way, the effect of improving the motion blur can be further enhanced.

  The image light restriction region of the image light restriction device can be configured by an electro-optic element.

  In this way, it is possible to easily configure the image light limited area.

Hereinafter, embodiments of the present invention will be described in the following order based on examples.
A. Projector configuration:
B. Image light limiting device configuration:
C. Driving operation of image light limiting device:
D. Variation:

A. Projector configuration:
FIG. 1 is an explanatory diagram showing a schematic configuration of a projector as an embodiment of the present invention. The projector 1000 includes an optical system block 100 for projecting an image and a control system block 200 for controlling image projection.

  The optical system block 100 includes an illumination optical system 110, a color light separation optical system 120, three light valves 130R, 130G, and 130B, a cross dichroic prism 140, an image light limiting device 150, and a projection lens (projection optical system). 160.

  The illumination optical system 110 includes a light source device 111, light used to emit light representing an image (hereinafter referred to as “image light”) from three light valves 130R, 130G, and 130B, so-called illumination light. Inject.

  The color light separation optical system 120 separates the light emitted from the illumination optical system 110 into three color lights of red (R), green (G), and blue (B), and a light valve 130R assigned for each color. , 130G and 130B.

  Each color light valve 130R, 130G, 130B converts the color light incident thereon into image light of the corresponding color and emits it toward the cross dichroic prism 140. These light valves 130R, 130G, and 130B can be configured by, for example, a transmissive liquid crystal panel, an incident-side polarizing plate, and an emission-side polarizing plate. This liquid crystal panel has a plurality of liquid crystal cells arranged in a matrix and constituting a plurality of pixels, and each liquid crystal cell is sequentially scanned in the column direction and the row direction, and image data corresponding to each is written. Thus, the incident light is modulated to emit image light. The light valves 130R, 130G, and 130B correspond to the display device of the present invention.

  The cross dichroic 140 combines the image light of each color emitted from the light valves 130R, 130G, and 130B for each color, and emits the combined light as image light representing a color image.

  The image light restricting device 150 restricts the emission to the projection lens 160 by restricting the transmission of a part of the combined light (image light) emitted from the cross dichroic prism 140 and incident thereon. As a device that realizes such an image light emission restriction function, for example, a transmissive liquid crystal panel can be used.

  The projection lens 160 projects the image light emitted from the image light limiting device 150 onto the screen SC.

  The configuration and functions of the optical system as shown in FIG. 1 are described in detail in, for example, Japanese Patent Application Laid-Open No. 2003-270636 disclosed by the applicant of the present application, except for the image light limiting device. Detailed description is omitted in this specification. The configuration and function of the image light limiting device 150 will be described in detail later.

  FIG. 2 is an explanatory diagram showing a schematic configuration of the control system block. The control system block 200 includes an input signal processing unit 210, an image signal processing unit 220, a frame memory 230, a light valve driving unit 240 and an image light limiting device driving unit 250 as a device driving unit of the present invention, and a control unit. 260.

  The control unit 260 includes a CPU and a memory (not shown), and reads and executes a control program and processing conditions stored in the memory, whereby an input signal processing unit 210, an image signal processing unit 220, a light valve driving unit 240, and The operation of the image light limiting device driving unit 250 is controlled.

  The input signal processing unit 210 is a processing circuit for converting an input video signal into a signal that can be processed by the image signal processing unit 220. For example, in the case of an analog video signal, the analog image signal included in the video signal is converted into a digital image signal in synchronization with the synchronization signal included in the video signal. In the case of a digital video signal, the digital image signal included in the video signal is converted into a signal in a format that can be processed by the image signal processing unit 220 according to the type of the signal.

  The image signal processing unit 220 sequentially synchronizes the image data of each frame included in the digital image data signal WVDS output from the input signal processing unit 210 with the corresponding synchronization signal WSYNC for writing in the frame memory. 230 is written. Note that the writing synchronization signal WSYNC includes a vertical synchronization signal, a horizontal synchronization signal, and a clock signal.

  Further, the image signal processing unit 220 generates a readout synchronization signal RSYNC based on the control conditions given from the control unit 260, and the image stored in the frame memory 230 in synchronization with the readout synchronization signal RSYNC. By reading the data, the read image data signal RVDS is output to the luminance modulation driving unit 240. Further, a synchronization signal RSYNC for reading is output to the luminance modulation driving unit 240 and the luminance limiting driving unit 250. Note that the readout synchronization signal RSYNC includes a vertical synchronization signal, a horizontal synchronization signal, and a clock signal. Further, the frequency of the vertical synchronizing signal for reading is set to be the same as the frequency (frame rate) of the vertical synchronizing signal for writing the video signal written in the frame memory 230.

  Based on the read image data signal RVDS and the read synchronization signal RSYNC supplied from the image signal processing unit 220, the light valve drive unit 240 generates a drive signal for driving the light valves 130R, 130G, and 130B for each color. . This drive signal includes a drive image data signal including drive image data of each pixel and a drive control signal including a horizontal synchronization signal, a vertical synchronization signal, a clock signal, an enable signal, and the like.

  The image light limiting device driving unit 250 generates a drive signal for driving the image light limiting device 150 based on the readout synchronization signal RSYNC. This drive signal includes an image light restriction data signal and an image light restriction control signal described later.

B. Image light limiting device configuration:
FIG. 3 is an explanatory diagram showing the configuration of the image light limiting device. As shown in FIG. 3, the image light limiting device 150 includes a liquid crystal panel 151, an incident side polarizing plate 152 i provided on the light incident surface side thereof, and an emission side polarizing plate 152 o provided on the light emission surface side thereof. It is equipped with. The incident-side polarizing plate 152i and the emission-side polarizing plate 152o are disposed at a position spaced from the liquid crystal panel 151. Of course, it may be arranged at a position in contact with the liquid crystal panel 151.

  The incident-side polarizing plate 152 i transmits only the light having the same polarization direction as the set polarization axis among the image light incident on the image light limiting device 150. Accordingly, only the linearly polarized light transmitted through the incident side polarizing plate 152i is incident on the liquid crystal panel 151. In order to increase the light use efficiency, the polarization axis of the incident-side polarizing plate 152i is usually in the polarization direction of the image light emitted from the light valves 130R, 130G, and 130B for each color and synthesized by the cross dichroic prism 140. It is set to be equal. The polarization direction of the image light incident on the liquid crystal panel 151 is modulated in accordance with the input drive signal. Then, the modulated light emitted from the liquid crystal panel 151 enters the emission-side polarizing plate 152o. The exit side polarizing plate 152o emits only linearly polarized light having the same polarization direction as the set polarization axis as image light.

  FIG. 4 is an explanatory diagram showing a functional configuration of a liquid crystal panel included in the image light limiting device.

  The liquid crystal panel 151 includes a cell array 340 and a row drive circuit 350 and a column drive circuit 360 that control the operation of the cell array.

  The cell array 340 is wired along n (n is an integer of 2 or more) scanning lines RV1 to RVn wired in parallel along the horizontal direction (horizontal direction) of the paper, and along the vertical direction (vertical direction) of the paper. In addition, n liquid crystal cells 342 (V1 to Vn) are arranged in the row direction at each intersection of each scanning line and data line. . Each liquid crystal cell 342 has a scanning line and data forming each intersection via a thin film transistor (hereinafter referred to as “TFT”) 343, as shown in an enlarged circle in a dot-dash line. Connected to the wire. Specifically, the gate electrode of the TFT 343 is connected to the scanning line, the source electrode is connected to the data line, and the drain electrode is connected to the electrode of the liquid crystal cell 342.

  Here, as described above, the light valves 130R, 130G, and 130B for each color include a liquid crystal panel having n rows and m columns of liquid crystal cells arranged in a matrix, and an incident light. Each of the pixels is sequentially scanned in the column direction and the row direction based on drive control signals such as a horizontal synchronization signal and a vertical synchronization signal, respectively. It is assumed that image light representing an image is emitted by writing data. The size of each liquid crystal cell 342 is set to a size corresponding to the image light for one row of the image represented by the image light. Each liquid crystal cell 342 corresponds to an image light restriction region of the present invention.

  Here, when a scanning signal is applied to a scanning line connected to a certain TFT 343, the TFT 343 is turned on, and the liquid crystal cell 342 connected to the TFT 343 should be written to the liquid crystal cell from the data line. A voltage corresponding to the limit data (hereinafter also referred to as “limit voltage”) is applied. The liquid crystal cell 342 to which the limiting voltage is applied changes to the light transmittance corresponding to the voltage depending on the combination of the incident side polarizing plate and the emission side polarizing plate. As a result, the image light restriction device 150 can restrict the emission of incident image light in accordance with the restriction data written in each liquid crystal cell 342.

  The row driving circuit 350 is a period during which the light valve drives m columns of pixels arranged in the column direction for each row (a horizontal scanning period based on a horizontal synchronization signal which is one of the drive control signals included in the drive signal of the light valve). ) Based on the vertical synchronization signal RBVs and the horizontal synchronization signal RBHs as the image light restriction control signals supplied from the image light restriction device driving unit 250, the scanning signals are sequentially applied to the n scanning lines RV1 to RVn. By applying and activating, n rows of liquid crystal cells 342 arranged in the row direction are sequentially driven.

  The column drive circuit 360 uses, as a drive signal supplied from the image light restriction device drive unit 250, a restriction voltage corresponding to the image light restriction data represented by the image light restriction data signal RBDdata supplied from the image light restriction device drive unit 250. Are applied sequentially to the liquid crystal cell 342, which is an image light restriction region, via the data line RH1 based on the horizontal synchronization signal RBHs and the horizontal drive enable signal RBHEEnb, thereby writing the corresponding image light restriction data. .

  Since the image light limiting device 150 has the above-described configuration, the light valve sequentially scans m columns of pixels in each row in the column direction, and each driving image data is written for each period, that is, In each horizontal scanning period based on the horizontal synchronizing signal, the n rows of liquid crystal cells 342 arranged in the row direction of the liquid crystal panel 151 are sequentially scanned, and the corresponding image light restriction data is written. Thereby, the image light restriction device 150 realizes a function of restricting the emission of image light according to the written image light restriction data. As described above, the image light limiting device 150 sequentially shifts the n columns of liquid crystal cells 342 arranged in the row direction while sequentially scanning the m columns of pixels in each row in the column direction. Since it is necessary to scan, write image light restriction data, and execute image light emission restriction according to this, it is preferable to use a liquid crystal with relatively high response characteristics. However, as will be described later, it is not necessary to control the emission of the image light in multiple stages, and any liquid crystal that can control whether or not to shut off may be used.

C. Driving operation of image light limiting device:
FIG. 5 is an explanatory diagram showing the driving operation of the image light limiting device. FIG. 5A shows a display target image to be read from the frame memory 230 and displayed in the N-th frame (N is an integer of 1 or more). FIG. 5B shows drive image data written to the light valves 130R, 130G, and 130B for each color and emitted as image light in the period of the Nth frame. The light valves 130R, 130G, and 130B for each color have different colors of incident light, and the drive image data signal included in the drive signal supplied from the light valve drive unit 240 corresponds to each color. 5B is the same except that it is an image signal to be transmitted. Therefore, in order to facilitate the explanation, FIG. 5B shows the image light to one light valve 130 without distinguishing R, G, and B. As shown, the drive image data to be ejected is written. FIG. 5C shows image light restriction data that is written in the cell array 340 of the liquid crystal panel 151 constituting the image light restriction device 150 and restricts the emission of the image light in the period of the Nth frame. FIG. 5D shows an image (display image) represented by the image light emitted from the image light limiting device 150 and projected by the projection lens 160 in the period of the Nth frame. For ease of explanation, the number of rows n of the light valve pixels and the image light restriction region of the image light restriction device is “6”.

  In the light valve 130, for each pixel from the first row to the sixth row within each frame period, as shown in FIG. 5B, each row in the vertical direction (row direction) is horizontal. Corresponding drive image data is sequentially written to the pixels in each column arranged in the direction (column direction), and six levels of drive image data PM [N (1)] and PM [N (2) changing in units of rows. ),... PM [N (6)] corresponding to the image light is emitted.

  In the image light limiting device 150, the liquid crystal cells (images) in the first to sixth rows are displayed every time the drive image data of each row is written in the light valve 130 (horizontal scanning period based on the horizontal synchronization signal). As shown in FIG. 5 (c), brightness restriction data BM (1), BM (2),... BM (6) that change in six steps are written in the light restriction region 342, respectively. Correspondingly limited image light is emitted. The image light restriction data at each stage blocks the transmission of light in the row where the drive image data is written by the light valve 130 (this row corresponds to the scanning row of the present invention), and the other row's image light restriction data. The limit data is such that light is transmitted without being limited. For example, when the drive valve data is being written to the liquid crystal cell in the first row by the light valve 130, the transmission of the light in the first row is blocked and the light in the second to sixth rows is blocked. Image light restriction data that does not restrict transmission is written. Note that the rows where light transmission is blocked are indicated by cross hatching. Next, when driving image data is being written in the second row, image light that blocks light transmission in the second row and does not restrict light transmission in the first to third rows during that time. Limit data is written. Then, in the image light limiting device 150, the writing of the image light limiting data is repeated in the same manner, and when the driving image data is written in the last 6th row, the 6th row Image light restriction data that blocks light transmission and does not restrict light transmission in the first to fifth rows is written.

  When the image light limiting device 150 operates as described above, an image represented by the image light emitted from the image light limiting device 150 and projected by the projection lens 160 is a driving image as shown in FIG. It is possible to block the emission of the image light from the line in which data is being rewritten and to display the black line as the display for that line. Note that the row where the emission of the image light is blocked is indicated by cross hatching. As a result, it is possible to display a new rewritten image after effectively erasing the visual influence of the image displayed before the rewriting, so that each pixel as described in the prior art can be displayed. However, it is possible to suppress the moving image blur caused by the hold type electro-optic element such as liquid crystal.

  In addition, the image light limiting device can be configured easily and inexpensively by a low-resolution liquid crystal panel in which liquid crystal cells are arranged in the row direction, so that a conventional special liquid crystal panel having a complicated control circuit is used. Compared to the case where a projector is configured, a projector with improved moving image blur can be realized with a simple and inexpensive configuration.

D. Variation:
In addition, this invention is not restricted to said Example and embodiment, In the range which does not deviate from the summary, it is possible to implement in various aspects.

D1. Modification 1:
FIG. 6 is an explanatory diagram showing a driving operation of the image light limiting device as a modified example. In the driving operation of the image light limiting device in the embodiment shown in FIG. 5, driving image data is rewritten in the light valve as an image (display image) represented by the image light emitted from the image light limiting device 150. The image light restriction device 150 writes image light restriction data so as to block the emission of the image light in the row and display a black image. However, as shown in FIG. 6, the black image may be displayed by blocking the emission of the image light in the row in which the drive image data is rewritten in the light valve and the previous row. Specifically, in FIG. 6, at the time of rewriting the driving image data on the first row in the light valve, the image light limiting device blocks the transmission of light on the first row and the second row on the second row. The image light restriction data that does not restrict the transmission of light in the fifth row is written, and a black image may be displayed in the first and sixth rows. Next, at the time of rewriting the driving image data in the second row, the image light limiting device blocks the transmission of light in the second row and the first row, and limits the transmission of light in the third to sixth rows. The image light restriction data that is not to be written is written, and the black image may be displayed in the second row and the first row. In the image light limiting device, the writing of the image light limiting data is repeated every time the driving image data of each row is rewritten in the same manner, and the image light is rewritten when the driving image data of the last six rows is rewritten. In the limiting device, image light limiting data that blocks the transmission of light in the second row of the sixth row and the fifth row and does not block the transmission of light in the first to fourth rows is written. A black image may be displayed on two lines.

  Further, in the modification shown in FIG. 6, the light valve is configured to display the black image by blocking the emission of the image light in the two rows of the row in which the drive image data is rewritten and the previous row. Although described as an example, a configuration may be adopted in which a black image is displayed by blocking the emission of image light of three or more lines including at least a line that has been rewritten.

  It should be noted that such image light restriction data for blocking a plurality of rows of image light can be easily changed by changing the control conditions given to the image light restriction device driving unit 250 from the control unit 260 shown in FIG. Is possible. Thereby, image light restriction data capable of appropriately suppressing the occurrence of moving image blur can be written in the image light restriction device 150, and the emission restriction of the image light in the image light restriction device can be appropriately executed. Further, such a change in the image light restriction data may be performed according to the detected amount of motion by detecting the amount of motion of the image. In this way, it is possible to suppress the occurrence of blurring of moving images by changing the number of rows that block image light to an optimal value according to the amount of motion.

D2. Modification 2:
FIG. 7 is an explanatory diagram showing a driving operation of the image light limiting device as another modified example. In the driving operation of this modification, the period of one frame is divided into two subframe periods, and the operation performed in the period of one frame of the embodiment in the period of the first subframe 1 and the period of the second subframe 2 is performed. The operation | movement repeated twice is shown. In this case, since the same image can be displayed twice in one frame period, there is an effect of suppressing the occurrence of flicker compared to the case where the image is displayed once in one frame period. When the video signal input from the outside is an interlace video signal, the first field can be operated as subframe 1 and the second field can be operated as subframe 2.

  Further, one frame period may be divided into three or more subframe periods. Increasing the number of subframes is more effective in suppressing the occurrence of flicker.

D3. Modification 3:
In the image light limiting device of the above-described embodiment, a configuration in which image light limiting data for one screen is written while driving image data for one row is written in the light valve (horizontal scanning period based on the horizontal synchronization signal) is an example. However, the present invention is not limited to this, and the image light limiting device is configured by using a liquid crystal panel having a complicated control circuit for improving motion blur, which has been raised in the prior art. You may do it.

  Here, as described in the above embodiment, the size in the column direction (horizontal direction) of the liquid crystal cells as the image light limiting region is the size of the entire plurality of liquid crystal cells arranged along the column direction of the light valves. What is necessary is just to have the above, and a liquid crystal panel with a low resolution compared with the liquid crystal panel contained in a light valve can be used. For this reason, even if a liquid crystal panel having a complicated control structure is used, it can be configured relatively easily and inexpensively.

D4. Modification 4:
Since the image light limiting device only needs to be able to block the emission of image light in the row that is being rewritten by the light valve, at least the number of liquid crystal cells (the image light limiting device) is the same as the number of pixels of the light valve. It is possible to use a low-resolution liquid crystal panel having liquid crystal cells corresponding to rows in which a plurality of rows of light valves are combined into one row.

D5. Modification 5:
In the above-described embodiment, it is described that the emission of the image light in the row being rewritten by the light valve is cut off. However, it is not necessary to cut off the light completely, and it was emitted before the scan was executed. It is sufficient that the visual influence of the image represented by the image light can be limited to such an extent that it can be effectively erased.

D6. Modification 6:
In the projector 1000 of the above embodiment, the case where the transmissive image light limiting device 150 using the transmissive liquid crystal panel is used is described as an example. However, like the projector 1000B shown in FIG. The restriction device 150B may be used. As the reflective image composition limiting device 150B, a reflective liquid crystal panel, a digital micromirror device (trademark of Texas Instruments Incorporated), or the like can be used.

D7. Modification 7:
In the above embodiment, a projector using a transmissive liquid crystal panel, which is a display device, as a light valve has been described as an example. However, the present invention is not limited to this. It can also be applied to projectors using display devices using various hold-type electro-optical elements such as non-light-emitting display devices such as mirror devices and light-emitting display devices such as PDP, EL, and LED. is there.

It is explanatory drawing which shows schematic structure of the projector as one Example of this invention. It is explanatory drawing which shows schematic structure of a control system block. It is explanatory drawing shown about the structure of an image light limiting device. It is explanatory drawing which shows the functional structure of the liquid crystal panel contained in an image light limiting device. It is explanatory drawing shown about the drive operation | movement of an image light limiting device. It is explanatory drawing shown about the drive operation | movement of the image light limiting device as a modification. It is explanatory drawing shown about the drive operation | movement of the image light restriction | limiting device as another modification. It is explanatory drawing which shows schematic structure of the projector as a modification.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Optical system block 100B ... Optical system block 110 ... Illumination optical system 111 ... Light source device 120 ... Color light separation optical system 130 ... Light valve 130R, 130G, 130B ... Light valve 140 ... Cross dichroic prism 150 ... Image light limiting device 150B ... Image light limiting device 151... Liquid crystal panel 152 i .. incident side polarizing plate 152 o... Exit side polarizing plate 160... Projection lens (projection optical system)
DESCRIPTION OF SYMBOLS 200 ... Control system block 210 ... Input signal processing part 220 ... Image signal processing part 230 ... Frame memory 240 ... Light valve drive part 250 ... Image light restriction device drive part 260 ... Control part 340 ... Cell array 342 ... Liquid crystal cell 350 ... Row drive Circuit 360 ... Column drive circuit 1000 ... Projector 1000B ... Projector SC ... Screen

Claims (5)

A projector for projecting an image,
A display device for emitting image light representing the image;
A projection optical system that projects image light emitted from the display device;
An image light limiting device that is disposed in front of the surface on which the image light of the projection optical system is incident, and that restricts emission of the part of the image light incident from the display device to the projection optical system;
A device driver for driving the display device and the image light limiting device;
A projector comprising: The projector according to claim 1, wherein
The display device has a plurality of pixels configured by arranging hold-type electro-optical elements in a matrix, and each pixel is scanned in the column direction and the row direction in order to represent the image. Emit light,
The image light limiting device is an image corresponding to a scan row including at least pixels that are scanned along the column direction in the display device, out of the image light emitted and incident from the display device. Limiting the emission of light into the projection optical system;
A projector characterized by that. The projector according to claim 2, wherein
The image light limiting device has a plurality of image light limiting regions arranged along the row direction corresponding to at least one row of image light emitted from and incident on the display device. And at least the image light restriction region corresponding to the image light corresponding to the scanning row restricts the emission of the corresponding image light.
A projector characterized by that. The projector according to claim 3, wherein
A plurality of restriction regions including an image light restriction region corresponding to the scanning row, respectively, restrict emission of the corresponding image light;
A projector characterized by that. The projector according to claim 3 or claim 4, wherein
The image light restriction region of the image light restriction device is configured by an electro-optic element.

Images