JP2008116871A - Image display system and image display method - Google Patents

Abstract

Motion blur is suppressed with a relatively simple configuration.
An image display system for displaying an image. A target image display image display device for displaying a display target image on a display screen, and a moving image blur generated when a display image representing the display target image displayed on the display screen is visually recognized by a user A moving image blur suppression image display projector for projecting and displaying a moving image blur suppression image for suppression on the display screen so as to overlap the display image.
[Selection] Figure 1

Description

  The present invention relates to a technique for improving blurring of a moving image that occurs when a moving image is displayed on an image display apparatus using a display device having hold-type electro-optical characteristics.

  An image display apparatus using a liquid crystal panel as a display device has been widely used. However, when a moving image is displayed on the image display device using the liquid crystal panel, there is a problem that a blur or ghost of an outline of a moving object occurs. Hereinafter, the blur and ghost of the outline of these objects are collectively referred to as “moving image blur”.

  The reason for the occurrence of the moving image blur as described above is mainly that each pixel of the liquid crystal panel is a hold-type display device composed of elements having hold-type electro-optical characteristics. For this reason, the characteristics of the signal frequency represented by the image data given to each liquid crystal pixel have a low-pass time-frequency characteristic in which the response characteristic in the high frequency is lowered, and the luminance of each displayed pixel is the image It is held for one frame period (or one field period) of the signal. As a result, even if the next frame is reached, the memory of the previous frame remains due to human visual characteristics, so that both the images of the previous and subsequent frames are recognized in a superimposed manner, resulting in motion blur.

  As a technique for suppressing such moving image blur, an impulse-type display such as a CRT is provided for each pixel by providing a period in which image display is limited within one frame period, erasing the image stored in the previous frame. Various methods have been conceived for realizing the same operation as that of a device (see, for example, Patent Documents 1 to 6).

JP-A-4-302289 JP 2005-43829 A JP 2005-10579 A JP 2003-186456 A JP 2001-42282 A JP 2004-271719 A

  However, the techniques described in any of the above patent documents have an effect of suppressing moving image blur, but a complex circuit that executes various processes for providing a period in which no image is displayed within one frame period is an image processing circuit. And a mechanism realized by a drive circuit of a liquid crystal panel or the like. Therefore, an image display device that does not have a mechanism for suppressing the above-mentioned various moving image blurs cannot realize an image display that suppresses the moving image blurs.

  In addition, the problem of moving image blur is not only a liquid crystal panel (LCD), but also various plasma display panels (PDP), electroluminescence display panels (EL), digital micromirror devices (DMD, a trademark of Texas Instruments Incorporated), etc. This also occurs in an image display apparatus using a hold-type display device, and can be improved by the method of the above-mentioned patent document, but for that purpose, it is necessary to provide a complicated mechanism in the image display apparatus. It is common in having.

  The present invention has been made to solve the above-described problems in the prior art, and can suppress moving image blur with a relatively simple configuration, and does not have a moving image blur suppressing function. An object is to provide an effective technique for an image display device.

In order to solve at least a part of the problems described above, an image display system of the present invention includes:
An image display system for displaying an image,
An image display device for displaying a display target image for displaying the display target image on the display screen;
The display screen so that a moving image blur suppression image for suppressing a moving image blur generated when a display image representing the display target image displayed on the display screen is visually recognized by a user overlaps the display image. A projector for displaying a moving image with reduced blur for projection display on the screen;
It is characterized by providing.

  In the image display system, a display image representing a display target image displayed on the display screen by the display target image display device is generated when the display image is visually recognized by the user by the moving image blur suppression image display projector. By projecting a moving image blur suppression image for suppressing moving image blur so as to overlap the display image, it is possible to suppress moving image blur. This eliminates the need for providing a complicated mechanism in the image display device as in the prior art, and it is possible to suppress motion blur with a relatively simple configuration. In addition, even an image display device that does not have a moving image blur suppression function can display an image in which moving image blur is suppressed.

  The moving image blur suppression image is an image in which the position of a long strip-shaped dark image region along the horizontal direction of the display screen sequentially changes along the vertical direction of the display screen in a period of one frame or one field. It is preferable.

  Alternatively, the moving image blur suppression image may be an image in which the entire image changes to a dark image region in a part of one frame or one field period, and the entire image changes to a bright image region in another period. preferable.

  Moving image blur can be suppressed by projecting and displaying the moving image blur suppression image on the display image.

  The dark level of the dark image area is preferably determined according to the brightness of the display target image.

  If the dark level of the dark image area is determined according to the brightness of the display target image, it is possible to suppress the moving image blur while suppressing the decrease in the brightness of the display image that occurs due to the suppression of the moving image blur. It becomes.

  The present invention can also be realized in a mode as a projector for suppressing moving image blur in addition to the mode as the image display system. Further, the present invention is not limited to the aspect of the device invention, and can be realized by an aspect of a method invention such as an image display method. Note that the various additional elements described above can also be applied to the method invention.

Hereinafter, embodiments of the present invention will be described in the following order based on examples.
A. Overview of image display system:
B. Movie blur suppression projector configuration and movie blur suppression image display operation:
C. effect:
D. Variation:

A. Overview of image display system:
FIG. 1 is an explanatory diagram showing the configuration of an image display system 1000A as an embodiment of the present invention. In this image display system 1000A, a display target image display projector 100 that projects and displays an image to be displayed (hereinafter referred to as a “display target image”) on the projection plane SC and the projection display SC. The moving image blur suppression image display projector 200 that projects and displays the moving image blur suppression image DB superimposed on the display image DP that represents the display target image, and an image supply that supplies a display target image signal that represents the display target image to these two projectors. And a device PS. These two projectors are so-called liquid crystal projectors using a liquid crystal light valve by a liquid crystal panel as a light valve.

  The image display system 1000A projects and displays the moving image blur suppression image DB by the moving image blur suppression image display projector 200 on the display image DP projected and displayed by the display target image display projector 100, thereby displaying the display image. Suppresses moving image blur that occurs when only DP is projected and displayed.

  FIG. 2 is an explanatory diagram showing an image display operation by the image display system 1000A, and displays the period of the Nth frame (N is an integer of 1 or more) among the display target image signals supplied from the image supply device PS. The case where the display target image FPT represented by the target image signal is displayed by the display target image display projector 100 is shown as an example. 2A shows the display target image FPT, FIG. 2B shows the display image DP representing the display target image projected and displayed by the display target image display projector 100, and FIG. FIG. 2D illustrates a combined display image MDP in which the display image DP and the moving image blur suppression image DB are overlapped with each other. FIG. 2D illustrates the moving image blur suppression image DB projected and displayed by the moving image blur suppression image display projector 200. For ease of explanation, the number of lines (number of rows) of pixels of the liquid crystal light valve of the display target image display projector 100 is set to “6”, and the number of pixels of the liquid crystal light valve of the projector 200 for displaying moving image blur suppression images is displayed. The number of lines (number of lines) will be described as “3”.

  In the display target image display projector 100, corresponding image data is sequentially written for each row in the vertical direction (row direction) of a liquid crystal light valve (not shown) within a period of one frame, as shown in FIG. In this way, the display images DP [N (1)], DP [N (2)],... DP [N (6)] corresponding to the six-stage image data changing in units of rows are projected and displayed.

  In the moving image blur suppression image display projector 200, the liquid crystal light valve (not shown) corresponding to the pixel superimposed on the pixel in which the image data is rewritten in the liquid crystal light valve of the display target image display projector 100 is displayed. Dark image data is written and bright image data is written to another row, and as shown in FIG. 2C, a strip-shaped (belt-shaped) dark image area (area shown by cross-hatching in the figure) ) Is projected and displayed as a moving image blur suppression image DB (1), DB (2),... DB (6) that sequentially changes along the vertical direction in accordance with the change in the display image DP in six stages. . In this example, for ease of explanation, the number of liquid crystal light valves of the display target image display projector 100 is “6 lines”, and the number of liquid crystal light valves of the moving image blur suppression image display projector 200 is Is “3 lines”, and one line of the liquid crystal light valve of the projector 200 for moving image blur suppression image display corresponds to two lines of the liquid crystal light valve of the projector 100 for displaying image to be displayed. Out of the blur suppression images DB (1) to DB (6), the moving image blur suppression images DB (2), DB (4), and DB (6) in the second, fourth, and sixth stages are in the first, third, and fifth stages. This is the same as the moving image blur suppression image DB (1), DB (3), DB (5).

  As shown in FIG. 2D, a display image DP that changes in six steps and a moving image blur suppression image DB that changes in six steps (actually, in this example, three steps) in accordance with this change. The composite display image MDP is displayed by being superimposed on the projection screen SC. At this time, in the composite display image MDP at each stage, the image corresponding to the belt-shaped dark image region (region indicated by cross-hatching in FIG. 2C) of the moving image blur suppression image DB is the moving image of the other region. Compared to the image corresponding to the bright image area portion of the blur suppression image DB, the image becomes relatively dark. This cancels the visual memory of the image displayed before rewriting for the line in the display image DP that has been rewritten, and suppresses the motion blur described in the prior art. Is possible.

B. Movie blur suppression projector configuration and movie blur suppression image display operation:
FIG. 3 is an explanatory diagram showing the configuration of the display target image display projector 100 and the moving image blur suppression image display projector 200.

  The display target image display projector 100 is a normal projector, and includes an image processing unit 110, a projection display unit 120, a control unit 130 that controls the operations of the image processing unit 110 and the projection display unit 120 as a whole, It consists of

  In the display target image display projector 100, a display target image signal representing a display target image of each frame input at a frame period is converted into an image signal (display image signal) that can be used by the image processing unit 110 in the projection display unit 120. After being converted and supplied to the projection display unit 120, the projection display unit 120 projects and displays an image (display image DP) represented by the display image signal on the projection screen SC.

  On the other hand, the moving image blur suppression image display projector 200 includes a display timing generation unit 210, a dark level determination unit 220, a moving image blur suppression image generation unit 230, a projection display unit 240, the display timing generation unit 210, and a dark level. A determination unit 220, a moving image blur suppression image generation unit 230, and a control unit 250 that generally controls operations of the projection display unit 240.

  The display timing generation unit 210 controls the synchronization signal included in the display target image signal input in the same manner as the display target image display projector 100 in order to control the operation of the moving image blur suppression image generation unit 230 and the projection display unit 240. Based on this, a display timing signal such as a horizontal synchronization signal, a vertical synchronization signal, a clock signal, and an image generation start timing is generated.

  As will be described later, the dark level determination unit 220 determines the brightness level (dark level) of dark image data representing a dark image region included in the moving image blur suppression image.

  The moving image blur suppression image generation unit 230 generates a moving image blur suppression image as described with reference to FIG. 2 according to the display timing signal supplied from the display timing generation unit 210, and an image signal (moving image blur) that represents the generated moving image blur suppression image. A blur suppression image signal) is supplied to the projection display unit 240.

  The projection display unit 240 sequentially projects and displays an image (moving image blur suppression image) represented by the moving image blur suppression image signal supplied from the moving image blur suppression image generation unit 230 on the projection screen SC.

  FIG. 4 is an explanatory diagram showing a procedure for displaying a moving image blur suppression image executed by the moving image blur suppression image display projector 200.

  The moving image blur suppression image display projector 200 executes the display of the motion blur suppression image by repeatedly executing the processes of steps S10 to S40 until the display operation is ended (step S50: YES). As a premise of this display operation, the moving image blur suppression image screen projected and displayed on the projection screen SC by the moving image blur suppression image display projector 200 has no image distortion due to tilt projection, and the display target image display is performed. The projector 100 is adjusted so as to overlap at least the screen of the display image projected and displayed on the projection screen SC. Further, as described with reference to FIG. 2, it is necessary to match the display timing of the display image DP and the display of the moving image blur suppression image DB. By changing the shift amount of the display target image signal with respect to the synchronization timing of the synchronization signal by the control unit 250, the timing can be adjusted to an appropriate timing. Note that this screen adjustment is realized by a screen size and distortion adjustment function that is conventionally installed in a normal projector.

  First, in step S10, the display timing generation unit 210 detects the switching timing of each frame based on the synchronization signal (vertical synchronization signal and horizontal synchronization signal) included in the display target image signal, and sends it to the dark level determination unit 220. In response to the determination of the dark level, the display timing signal is generated.

  In step S20, the dark level determination unit 220, based on the image (display target image) represented by the display target image signal input during the period of one frame from the frame switching timing to the next frame switching timing, The dark level of the dark image area of the moving image blur suppression image is determined.

  In step S30, the moving image blur suppression image generation unit 230 generates a moving image blur suppression image using the dark level determined by the dark level determination unit 220 as the luminance level of the dark image data in the dark image region.

  In the description of the process, the dark level determination process in step S20 and the moving image blur suppression image generation process in step S30 are shown as processes that are executed in order, but each process is performed by the display timing generation unit 210. This process is executed in parallel with the display timing signal generated in the above.

  In step S40, the projection display unit 240 projects and displays an image (moving image blur suppression image) represented by the display image signal (moving image blur suppression image signal) supplied from the moving image blur suppression image generation unit 230 on the projection screen SC. To do.

  FIG. 5 is an explanatory diagram showing a dark level determination procedure executed by the dark level determination unit 220.

  First, in step S22, the brightness WL (N) of the display target image of the frame (referred to as the current input frame, referred to as N frame) represented by the input display target image signal is obtained. Various brightnesses can be used as the brightness WL. For example, the average luminance of each pixel can be used. In addition, since an image of interest in a moving image is generally concentrated near the center of the screen, the average luminance of pixels near the center of the screen can also be used. Furthermore, it is also possible to detect a moving area compared to the previous frame and use the average luminance of the area. Further, not only the average luminance but also the maximum luminance and the minimum luminance can be used. Furthermore, two or more average luminance, maximum luminance, and minimum luminance can be used in combination.

  In step S24, the dark image BL indicating the dark image region of the moving image blur suppression image corresponding to the display target image of the next input frame (N + 1 frame) is obtained by obtaining the dark level BL corresponding to the brightness WL (N). Determine the dark level of the data.

  FIG. 6 is an explanatory diagram showing the dark level BL corresponding to the brightness WL of the display target image. When the display target image is an image of a dark scene, the moving image blur can be sufficiently suppressed without setting the dark level to a very dark level. Further, it is preferable to set the dark level as bright as possible because the brightness of the entire screen can be secured. On the other hand, when the display target image is an image of a bright scene, the effect of suppressing moving image blur cannot be obtained unless the dark level is set as dark as possible. Therefore, by changing the dark level according to the brightness of the display target image, it is possible to suppress moving image blur without making the brightness of the screen darker than necessary.

  In the example of FIG. 6, the area from the lowest average luminance Ymin to the maximum average luminance Ymax is divided into three areas of A (bright) area, B (intermediate) area, and C (dark) area, and the brightness of the display target image. The case where the dark level BL is determined according to which region WL is divided into is shown. Specifically, since the brightness WL of the display target image is bright in the A region, the dark level BL is set to the minimum luminance level PYmin, and in the B region, the brightness WL of the display target image is an intermediate brightness. If the dark level BL is PY1 (= 0.1 · PYmax) that is slightly brighter than the minimum luminance level PYmin, and the brightness of the display target image is dark in the C region, the dark level BL is brighter than PY2 (PY2). = 0.3 · PYmax). As the levels of PY1 and PY2, an appropriate value may be obtained and set in advance through experiments or the like within the range from PYmin to PYmax.

  Here, as described above, the dark level used as the luminance level of the dark image data by the moving image blur suppression image generation unit 230 depends on the brightness WL (N) of the display target image of the current frame that is actually displayed. It is not a dark level but a dark level corresponding to the brightness WL (N−1) of the display target image of the previous frame. Therefore, when the display target image of the current frame is projected and displayed by the display target image display projector 100, the moving image blur suppression image DB projected and displayed on the display image DP by the moving image blur suppression image display projector 200 is displayed. Strictly speaking, a dark level suitable for the display target image of the previous frame is used. However, it is unlikely that the brightness of the moving image will change suddenly between the previous frame and the current frame, and there is virtually no problem.

  In addition, when the display target image of the current frame is projected and displayed, the moving image blur suppression image projected and displayed superimposed on the display image DP using the dark level obtained based on the brightness of the display target image of the current frame Can be realized, for example, by providing a mechanism for delaying the display timing by one frame in the display target image display projector 100. For example, the image processing unit 110 included in the display target image display projector 100 shown in FIG. 3 can be easily realized by providing a delay buffer circuit for delaying display for a period of one frame.

C. effect:
In the image display system 1000A, when the display target image is projected and displayed as the display image DP by the display target image display projector 100, the moving image blur suppression image display projector 200 causes a belt-like dark image region that is long in the horizontal direction. The moving image blur suppression image DB whose position sequentially changes along the vertical direction during the period of one frame is projected and displayed superimposed on the display screen DP projected and displayed on the projection surface SC. In the display image DP, it is possible to cancel the visual blurring of the image that was displayed before the rewriting is performed on the line that has been rewritten, and to suppress the moving image blur described in the related art. Become.

  In particular, in the image display system 1000A, a projector that projects and displays a display target image can use a conventional projector as it is, and even if it is a projector that does not have a special mechanism for suppressing moving image blur, It is possible to display an image with reduced moving image blur.

  Further, unlike the display target image display projector 100, the moving image blur suppression image display projector 200 projects an image in which a belt-like dark image region that is long in the horizontal direction changes in the vertical direction in order during one frame period. The display target image display projector 100 does not need to display an image with a high resolution like the display target image projected and displayed. For this reason, the moving image blur suppression image display projector 200 can use a liquid crystal panel having a relatively low resolution as a light valve, and can have a simple and inexpensive configuration. Therefore, it is possible to realize a mechanism for suppressing moving image blur 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:
In the above embodiment, for ease of explanation, the liquid crystal light valve of the display target image display projector 100 is a six-line liquid crystal panel, and the liquid crystal light valve of the moving image blur suppression image display projector 200 is a three-line liquid crystal panel. The belt-like dark image region having a height of one row has been described as an example of a moving image blur suppression image in which the vertical direction changes in order in the vertical direction. The dark image area may be used. The height of the dark image area is set in advance from the control unit 250 to the moving image blur suppression image generation unit 230, and the adjustment function provided in the control unit 250 is operated to check the image displayed by the user. However, it is possible to adjust and determine the height of the dark image region so that the moving image blur suppression effect can be appropriately obtained.

D2. Modification 2:
In the above embodiment, as described with reference to FIG. 2, the moving image blur suppression image display projector 200 causes the display screen DP corresponding to the display target image projected and displayed on the projection screen SC to be horizontally aligned. The case where the moving image blur suppression image DB in which the position of the long belt-like dark image region sequentially changes in the vertical direction during one frame is superimposed and displayed is shown as an example.

  However, the moving image blur suppression image is not limited to the embodiment. For example, as shown in FIG. 7, a one-frame period is divided into a normal display period and a dark display period. A dark image having a dark level luminance determined from the brightness of the target image is displayed, and in a normal display period, a bright image having a luminance level higher than the dark level luminance, for example, a maximum level luminance is displayed. You may make it display.

D3. Modification 3:
In the above embodiment, the case where the image signal is input in units of frames has been described as an example, but the same applies to the case where the image signal is input in units of fields.

D4. Modification 4:
The display target image display projector 100 of the above embodiment has been described by taking a projector using a liquid crystal light valve as an example, but it may be a projector using a digital micromirror device (DMD).

D5. Modification 5:
In the image display system 1000A of the above-described embodiment, an example in which the moving image blur suppression image display projector 200 superimposes the moving image blur suppression image DB on the display image DP projected and displayed by the display target image display projector 100 and displays the projected image. However, the present invention is not limited to this. For example, as in the image display system 1000B shown in FIG. 8, the moving image blur suppression image display projector 200 is displayed on the display screen DD of the direct view type image display apparatus 100B using a hold type display device such as an LCD, PDP, EL or the like. However, the moving image blur suppression image DB may be superimposed and projected.

It is explanatory drawing which shows the structure of 1000 A of image display systems as one Example of this invention. It is explanatory drawing shown about the image display operation | movement by the image display system 1000A. It is explanatory drawing which shows the structure of the display object image display projector 100 and the moving image blurring suppression image display projector 200. FIG. It is explanatory drawing shown about the display procedure of the motion blur suppression image performed with the projector 200 for motion blur suppression image display. It is explanatory drawing shown about the determination procedure of the dark level performed in the dark level determination part 220. FIG. It is explanatory drawing shown about the dark level BL corresponding to the brightness WL. It is explanatory drawing shown about the modification of a moving image blur suppression image. It is explanatory drawing shown about the modification of an image display system.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1000A ... Image display system 1000B ... Image display system 100 ... Target image display projector 100B ... Image display device 110 ... Image processing part 120 ... Projection display part 130 ... Control part 200 ... Projector for moving image blur suppression image display 210 ... Display timing generation Unit 220 ... dark level determination unit 230 ... moving image blur suppression image generation unit 240 ... projection display unit 250 ... control unit PS ... image supply device SC ... projection plane

Claims (6)

An image display system for displaying an image,
A target image display image display device for displaying a display target image on a display screen;
The display screen so that a moving image blur suppression image for suppressing a moving image blur generated when a display image representing the display target image displayed on the display screen is visually recognized by a user overlaps the display image. A projector for displaying a moving image with reduced blur for projection display on the screen;
An image display system comprising: The image display system according to claim 1,
The moving image blur suppression image is an image in which the position of a long strip-shaped dark image region along the horizontal direction of the display screen sequentially changes along the vertical direction of the display screen in a period of one frame or one field. An image display system characterized by that. The image display system according to claim 1,
The moving image blur suppression image is an image in which the entire image changes to a dark image region in a part of one frame or one field period, and the entire image changes to a bright image region in another period. Image display system. The image display system according to claim 2 or 3,
The dark level of the dark image area is determined according to the brightness of the display target image. An image display method for displaying an image,
Display the display target image on the display screen,
The display screen so that a moving image blur suppression image for suppressing a moving image blur generated when a display image representing the display target image displayed on the display screen is visually recognized by a user overlaps the display image. Project and display on top,
An image display method characterized by the above. A projector for suppressing a moving image blur that is used in an image display system that displays an image on a display screen and that occurs when a display image representing a display target image displayed on the display screen is visually recognized,
A projector, wherein a moving image blur suppression image for suppressing the moving image blur is projected on the display screen so as to overlap the display image.

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