JP2009217136A - Display device, display method, and computer program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress a blurred moving image caused by black insertion, while suppressing the reduction in brightness. <P>SOLUTION: In the first half of one frame period of a video signal AV, an image is displayed on the basis of frame image data FLr, FLg and FLb being a raw image for each of color components of R, G and B. In the second half of one frame period of the video signal AV, the image is displayed on the basis of black sub-frame image data with respect to two of the components of R, G and B and is displayed on the basis of intermediate image data with respect to one other component. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a technique for displaying a color image.

  Some display devices that display color images include a liquid crystal panel. The liquid crystal panel performs display by blocking or transmitting external light or light emitted by a light source such as a front light or a backlight.

  Since the liquid crystal panel is a hold-type display device, moving image blur due to an afterimage occurs. As a technique for suppressing this moving image blur, a technique for displaying a black image between a frame image and a frame image included in a video signal is well known (for example, Patent Document 1 below). Displaying this black image is called “black insertion”.

  As one of display devices including the liquid crystal panel, a three-plate liquid crystal projector including three liquid crystal light valves corresponding to red (R), green (G), and blue (B) has been proposed.

JP-A-11-202285

  However, in a display device including a liquid crystal panel, there is a problem that the luminance of an image to be displayed is reduced by inserting black. In particular, in a three-plate type liquid crystal projector, black insertion is performed in three liquid crystal light valves, and a decrease in luminance of the image cannot be overlooked.

  The present invention has been made in order to solve at least a part of the above-described conventional problems, and an object thereof is to suppress motion blur due to black insertion while suppressing a decrease in luminance.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

[Application Example 1]
A display device for displaying a color image,
A plurality of display panels corresponding to each color component of the color;
A plurality of frame memories for storing image data for one frame for each color component as frame image data of each color based on an input video signal;
A driving image data generating unit that generates driving image data for each color component based on frame image data of each color stored in each frame memory;
A display panel driving unit that drives each of the plurality of display panels based on the driving image data for each color component;
The drive image data generation unit includes:
One frame period of the video signal is divided into a plurality of subframe periods, and at least one subframe period of the plurality of subframe periods includes black level image data indicated by a low luminance value as a black level. Display of sub-frame image data of at least one specific color component and sub-frame image data of other color components excluding the specific color component including image data based on the frame image data stored in the frame memory As described above, the display device is configured to determine drive image data for each of the color components.

  According to the display device of the application example 1, driving image data for each color component is generated based on the frame image data of each color stored in the frame memory, and in particular, within one frame period of the video signal. In at least one subframe period, black subframe image data of a specific color component including black level image data and subframe image data of other color components including image data based on the frame image data are displayed. For this reason, the ratio of black insertion can be reduced as compared with the case where black insertion is performed for all the sub-frame image data of each color component. Decreasing the ratio of black insertion can suppress a decrease in luminance, and nevertheless can suppress motion blur due to black insertion.

[Application Example 2]
In the display device according to the application example 1, the frame image data of each color stored in each frame memory in the first subframe period in one frame period of the video signal In the first output unit that outputs the image data for driving and the second sub-frame period in one frame period of the video signal, the entire display image is indicated by the low luminance value. The black subframe image data as the subframe image data and the image data based on the frame image data stored in the frame memory on the entire display surface, the predetermined subframe image data of the other color components And a second output unit that outputs sub-frame image data as drive image data for each color component.

  According to the display device of Application Example 2, the frame image data of each color stored in each frame memory is output as drive image data for each color component in the first subframe period of one frame period of the video signal. Is done. In the second period of one frame period of the video signal, black subframe image data is output as drive image data in a specific color component, and predetermined subframe image data is output as a drive image in other color components. Output as data. For this reason, black insertion can be performed with a simple configuration.

[Application Example 3]
In the display device according to application example 2, in the period obtained by adding one frame period of the video signal by the number of the color components, the number of times the black subframe image data is displayed is uniform for each color component. A display device configured as described above.

  According to the display device of application example 3, it is possible to make the ratio of black insertion the same for each color component.

[Application Example 4]
4. The display device according to application example 2 or 3, wherein the predetermined sub-frame image data represents an intermediate image between frames predicted from the frame image data stored in the frame memory. .

  According to the display device of application example 4, it is possible to make the display image smoother.

[Application Example 5]
The display device according to any one of Application Examples 2 to 4, wherein the second output unit is a black device that sequentially switches a combination of selecting the specific color component from the plurality of color components as time elapses. A display device comprising an insertion pattern changing unit.

  According to the display device of Application Example 5, it is possible to suppress moving image blurring for each color component.

[Application Example 6]
The display device according to Application Example 5, wherein the black insertion pattern changing unit stores in advance a map data storage unit that stores a plurality of map data that defines the switching mode, and one map data from the map data storage unit. A display device comprising: an acquisition unit that acquires based on the video signal; and a switching execution unit that performs the switching according to the acquired map data.

  According to the display device of the application example 6, it is possible to select an insertion pattern for black insertion corresponding to a video signal, and thus it is possible to improve a video quality.

[Application Example 7]
The display device according to application example 1, wherein the drive image data generation unit includes a display portion and a non-display portion in one display surface of each color component, and the display portion is stored in the frame memory. The display device is configured to determine drive image data for each color component so that the non-display portion is configured by the black level image data, and the non-display portion is configured by a part of the frame image data.

  According to the display device of Application Example 7, it is possible to insert black into a part of one screen of each color component. Therefore, it is easy to meet the demand for changing the black insertion pattern in various ways.

The display method as another application example is
A display method for displaying a color image on a display device including a plurality of display panels corresponding to each color component of color,
(A) storing one frame of image data for each color component as frame image data of each color based on the input video signal;
(B) generating drive image data for each color component based on the frame image data of each color;
(C) driving each of the plurality of display panels based on the driving image data for each color component, and
The step (b)
One frame period of the video signal is divided into a plurality of subframe periods, and at least one subframe period of the plurality of subframe periods includes black level image data indicated by a low luminance value as a black level. Display of sub-frame image data of at least one specific color component and sub-frame image data of other color components excluding the specific color component including image data based on the frame image data stored in the frame memory As described above, the display method is configured to determine drive image data for each of the color components.

Another example of a computer program is
In a computer program for displaying a color image in a computer that controls a plurality of display panels corresponding to each color component,
A function of storing image data for one frame for each color component as frame image data of each color based on an input video signal;
A function of generating driving image data for each color component based on the frame image data of each color;
A function of driving each of the plurality of display panels based on the driving image data for each color component; and
The function of generating the driving image data is as follows:
One frame period of the video signal is divided into a plurality of subframe periods, and at least one subframe period of the plurality of subframe periods includes black level image data indicated by a low luminance value as a black level. Display of sub-frame image data of at least one specific color component and sub-frame image data of other color components excluding the specific color component including image data based on the frame image data stored in the frame memory As described above, a computer program having a configuration for determining driving image data for each color component.

  According to the display method and the computer program, similarly to the display device according to Application Example 1, it is possible to suppress moving image blur due to black insertion while suppressing a decrease in luminance.

  The present invention can be realized in various application examples or forms other than those described above. For example, the present invention can be implemented as various types of apparatuses (for example, projectors) including the form of a system including a display device as an application example and the display apparatus as an application example. It can be realized in a form or the like.

Next, embodiments of the present invention will be described in the following order based on examples.
A. First embodiment:
A-1. Projector configuration:
A-2. Configuration of control unit:
A-3. Control processing procedure:
A-4. effect:
B. Second embodiment:
C. Modifications of the first and second embodiments:
D. Third embodiment:
E. Other variations:

A. First embodiment:
A-1. Projector configuration:
FIG. 1 is an explanatory diagram showing a schematic configuration of a projector PJ in the first embodiment. The projector PJ includes a projection optical system OP for projecting an image on a screen (not shown) and a control unit CT that controls the projection light.

  The projection optical system OP is called a three-plate transmissive liquid crystal (3LCD) system, and includes three transmissive liquid crystal light valves 10r, 10g, and 10b. The liquid crystal light valves 10r, 10g, and 10b are of an active matrix type in which pixels are arranged in a matrix on a quartz substrate and thin film transistors (TFTs) formed of high-temperature polysilicon are provided on the pixels. The liquid crystal light valves 10r, 10g, and 10b correspond to the “display panel” of the present invention.

  The projection optical system OP homogenizes the white light beam from the light source lamp 20 by the illumination optical system 30 including the integrator and the polarization conversion optical system and aligns the polarization direction, and then performs R (red), G by the dichroic mirrors 40 and 50. (Green) and B (Blue) are separated into light beams Lr, Lg, and Lb of three colors, and the light beams Lr, Lg, and Lb are irradiated to the liquid crystal light valves 10r, 10g, and 10b corresponding to the respective colors.

  The three liquid crystal light valves 10r, 10g, and 10b modulate the light beams Lr, Lg, and Lb of the three colors that have been irradiated using the driving signals Sr, Sg, and Sb of the respective colors sent from the control unit CT. To do. Thereby, light (image light) representing an image of each color is formed on the emission surface of each liquid crystal light valve 10r, 10g, 10b.

  The projection optical system OP further synthesizes the image light of each color by the dichroic prism 60 and projects it on a screen (not shown) by the projection lens 70. As a result, a color image having three colors R, G, and B as components is displayed on the screen.

  The projector PJ receives an input of the video signal AV from an external device such as a player, a video deck, or a personal computer. The control unit CT takes in the input video signal AV, and based on the video signal AV, the color of each of the above-described colors. Drive signals Sr, Sg, Sb are generated, and the drive signals Sr, Sg, Sb are output to the three liquid crystal light valves 10r, 10g, 10b. In this embodiment, the input video signal AV is an analog video signal indicating 60 frame images per second, and includes three components of R, G, and B.

A-2. Configuration of control unit:
FIG. 2 is a block diagram illustrating a configuration of the control unit CT. The captured video signal AV is input to the signal conversion circuit 102 and converted from an analog signal to a digital signal. The digital signal is written into the frame memories 110r, 110g, and 110b for each of R, G, and B components by the memory write control unit 104. Note that the frames are sequentially written into the frame memories 110r, 110g, and 110b in synchronization with the synchronization signal included in the video signal AV.

  The memory read control unit 112 stores image data for one frame of each color stored in the frame memories 110r, 110g, and 110b, that is, frame image data (R) FLr, frame image data (G) FLg, and frame image data ( B) FLb is read out at a double speed of a period (frame period) determined from the synchronization signal included in the video signal AV (that is, read out twice during one frame period). The read frame image data FLr, FLg, FLb is hereinafter referred to as “subframe image data SFr, SFg, SFb”. The sub-frame image data SFr, SFg, SFb of each color is sent to the intermediate image data generation unit 120 and the signal switching unit 130.

  The control unit CT also includes a CPU 140 and a memory 142. The CPU 140 reads and executes the control program and various data (processing conditions, etc.) stored in the memory 142, thereby performing the operation of each block including the intermediate image data generation unit 120 and the signal switching unit 130. Control.

  The intermediate image data generation unit 120 detects the second half ((61 to 120) / 120 seconds) of one frame period (1/60 seconds) of the video signal AV based on a control command from the CPU 140. Intermediate image data is generated in the second half subframe period (hereinafter referred to as “second subframe period”). The “intermediate image” is a predicted image (complementary image) between frames of the video signal AV. The intermediate image data generation unit 120 stores the subframe image data SFr, SFg, and SFb sent from the memory read control unit 112 in the second subframe period, and the previous processing (1/60 seconds before). The subframe image data SFr (-1), SFg (-1), and SFb (-1) are compared, the image data at the intermediate time between them is predicted, and the obtained predicted image data is used as the intermediate frame image. Data.

  FIG. 3 is an explanatory diagram illustrating an example of predicted image data. In the figure, the R component sub-frame image data SFr (−1) at the time of the previous processing when the ball is moving in the lower left direction and the current R component sub-frame image data SFr are shown together. . The ball B1 at the upper right is for the sub-frame image data SFr (-1) at the time of the previous processing, and the ball B2 at the lower left in the drawing is for the current sub-frame image data SFr. In the figure, the broken line B3 is the position of the ball indicated by the predicted image data.

  The intermediate image data generation unit 120 uses the motion compensation technique to generate an image (ball B1) based on the subframe image data SFr (-1)) at the previous processing and the subframe image data SFr sent this time. The movement direction and the movement amount are estimated, and an image (ball B3) at the intermediate time (the time between the previous processing and the current time) is generated. Similarly, the G component and the B component are separately performed.

  Returning to FIG. 2, the intermediate image data generation unit 120 writes the intermediate frame image data Mr, Mg, Mb for each of the R, G, and B components thus obtained in the frame memories 150r, 150g, 150b. Hereinafter, the frame memories 150r, 150g, and 150b are referred to as second frame memories 150r, 150g, and 150b, and the previous frame memories 110r, 110g, and 110b are referred to as first frame memories 110r, 110g, and 110b.

  The memory read control unit 152 reads the intermediate frame image data Mr, Mg, Mb stored in each of the second frame memories 150r, 150g, 150b, and sends it to the insertion image data generation unit 170.

  In addition to the intermediate frame image data Mr, Mg, Mb, the inserted image data generation unit 170 receives black subframe image data Kr, Kg, Kb for each of R, G, B color components from the black level generation unit 160. receive.

  The black level generation unit 160 generates black subframe image data Kr, Kg, Kb whose entire display surface (that is, all pixels) is indicated by the minimum luminance value for each of R, G, B color components. is there. The “minimum luminance value” here means that the gradation value is zero. Note that any gradation value can be used as long as it is a low luminance value sufficient as a black level instead of the minimum luminance value. For example, it is possible to generate black subframe image data for each of R, G, and B constituting all pixels with a low gradation value such as a value of 10 or a value of 20.

  The inserted image data generation unit 170 selects R from the intermediate frame image data Mr, Mg, Mb received from the memory read control unit 152 and the black subframe image data Kr, Kg, Kb received from the black level generation unit 160. , G, and B are selected one by one to generate insertion image data Ir, Ig, and Ib for each of the R, G, and B components. The selection is determined based on a control command indicating an insertion pattern from the CPU 140.

  FIG. 4 is an explanatory diagram showing an example of an insertion pattern that defines the insertion image data Ir, Ig, and Ib. As shown in the figure, when the insertion pattern is “pattern 0”, R intermediate frame image data Mr, G black subframe image data Kg, and B black subframe image data Kb, R, G, B Inserted image data Ir, Ig, and Ib are generated. When the insertion pattern is “pattern 1”, the R, G, and B insertion image data Ir is obtained from the R black subframe image data Kr, the G intermediate frame image data Mg, and the B black subframe image data Kb. , Ig, Ib are generated. When the insertion pattern is “pattern 2”, R, G, and B insertion image data Ir is obtained from the R black subframe image data Kr, the G black subframe image data Kg, and the B intermediate frame image data Mb. , Ig, Ib are generated.

  Specifically, the insertion image data generation unit 170 stores map data for storing the relationship between the insertion pattern shown in FIG. 4 and each of the insertion image data Ir, Ig, and Ib in advance. By comparing the control command indicating the map data with the map data, it is determined which image data is to be adopted as the R, G, B color components.

  Returning to FIG. By the operations of the intermediate image data generation unit 120, the second frame memories 150r, 150g, and 150b, the memory read control unit 152, the black level generation unit 160, and the inserted image data generation unit 170 described above, one frame period of the video signal AV is obtained. The inserted image data Ir, Ig, or Ib of any of the above pattern 0, pattern 1, or pattern 2, which is determined based on a control command indicating the insertion pattern from the CPU 140, is generated in the second subframe period. become. The generated insertion image data Ir, Ig, Ib is sent from the insertion image data generation unit 170 to the signal switching unit 130.

  The signal switching unit 130 converts the subframe image data SFr, SFg, SFb sent from the memory read control unit 112 and the insertion image data Ir, Ig, Ib sent from the insertion image data generation unit 170 to the CPU 140. Select based on control command from. Specifically, the subframe image data SFr, sent from the memory read control unit 112 in the first half ((1-60) / 120 seconds) of one frame period (1/60 seconds) of the video signal AV. SFg and SFb are selectively output, and the inserted image data Ir, Ig, and Ib are selectively output in the second half ((61 to 120) / 120 seconds) of one frame period (1/60 seconds) of the video signal AV. . The signal switching unit 130 outputs the selected image data to the liquid crystal driving unit 180 as driving image data Dr, Dg, Db. The first half of the one frame period is hereinafter referred to as “first subframe period”.

  The liquid crystal driving unit 180 supplies the driving signals Sr, Sg, Sb according to the driving image data Dr, Dg, Db sent from the signal switching unit 130 to the liquid crystal light valves 10r, r provided in the projection optical system OP (FIG. 1). Output to 10g and 10b, respectively.

A-3. Control processing procedure:
The CPU 140 controls each block in the control unit CT by executing a control process according to a predetermined computer program stored in the memory 142. As a result, the control unit CT can insert the black level data individually for each of the R, G, and B color components by combining the sub-frame image data SFr, SFg, SFb and the inserted image data Ir, Ig, Ib. . The control process executed by the CPU 140 will be described in detail below.

  FIG. 5 is a flowchart showing a control process executed by the CPU 140. This control process is repeatedly executed in a half time (1/120 seconds) of one frame period of the video signal AV determined from the synchronization signal included in the video signal AV. As shown in the figure, when the process is started, the CPU 140 increments the counter C1 by a value 1 (step S10). The counter C1 is for counting the number of frames of the video signal AV, and a value 0 is set as an initial value.

  Next, the CPU 140 is the first half ((1 to 60) / 120 seconds) of one frame period of the video signal AV (hereinafter, one frame period of the video signal AV is simply referred to as “one frame period”). Or the second half (61-120) / 120 seconds) (step S20). Here, when it is determined that it is the first half, that is, the first subframe period, the signal switching unit 130 selects the subframe image data SFr, SFg, SFb sent from the memory read control unit 112. (Step S30). As a result, in the first subframe period within one frame period, the drive signals Sr, Sg, Sb indicating the subframe image data SFr, SFg, SFb which are raw images are supplied to the liquid crystal light valves 10r, 10g, 10b. Is output. After the execution of step S30, the process returns to “Return” to end the control process once.

  On the other hand, if it is determined in step S20 that the second half of one frame period, that is, the second subframe period is reached, the CPU 140 proceeds to step S40 to the intermediate image data generation unit 120. Instruct to generate intermediate image data.

  Thereafter, the CPU 140 obtains a remainder when the numerical value obtained by subtracting the value 1 from the counter C1 is divided by 3, and stores the remainder as a variable C2 (step S50). When the counter C1 is 1, the value 0, which is the remainder when 0 (that is, 1-1 = 0) is divided by 3, is C2. When the counter C1 has the value 2, the value 1 that is the remainder when 1 (that is, 2-1 = 1) is divided by 3 is C2. When the counter C1 has the value 3, the value 2 that is the remainder when 2 (that is, 3-1 = 2) is divided by 3 is C2. When the counter C1 has a value of 4, the value 0, which is the remainder when 3 (that is, 4-1 = 3) is divided by 3, is C2. That is, as the frame progresses, the value of the variable C2 repeats 0, 1, and 2.

  In subsequent step S60, CPU 140 outputs the value of variable C2 to inserted image data generation unit 170 as a control command indicating an insertion pattern. Subsequently, the CPU 140 switches the signal switching unit 130 to the side for selecting the insertion image data Ir, Ig, and Ib sent from the insertion image data generation unit 170 (step S70). As a result, in the second subframe period within one frame period, the insertion image data Ir, Ig, and the insertion pattern data that are sequentially switched to “pattern 0”, “pattern 1”, and “pattern 2” according to the value of the variable C2. Ib is output to the liquid crystal light valves 10r, 10g, 10b as drive signals Sr, Sg, Sb. After the execution of step S70, the process returns to “Return” to end this control process once.

  FIG. 6 is a timing chart showing the time change of the image light of each color formed on the liquid crystal light valves 10r, 10g, and 10b according to the control process, together with the time change of various signals. FIG. 6A shows image lights of the liquid crystal light valves 10r, 10g, and 10b. FIG. 6B shows drive signals Sr, Sg, and Sb output from the liquid crystal drive unit 180. FIG. 6C shows R, G, and B signal components of the video signal AV. FIG. 6D shows black subframe image data Kr, Kg, Kb output from the black level generator 160. FIG. 6E shows the value of the counter C1 that determines the insertion pattern by the CPU 140. FIG.

  In the figure, T1 is the first frame period of the video signal. As shown in FIG. 6C, in the frame period T1, signal components (frame image data) R1, G1, B1 of each color for the first frame included in the video signal AV are input. As shown in FIG. 6B, in the first subframe period T1a of the frame period T1, the signal components R1, G1, and B1 are shortened to one half of the one frame period. And output as drive signals Sr, Sg, Sb. As a result, as shown in FIG. 6A, image light of each color of the first frame included in the video signal AV is formed in each liquid crystal light valve 10r, 10g, 10b.

  As shown in FIG. 6D, in the second subframe period T1b in the frame period T1, the black level frame 160 receives the black subframe image data Kr, Kg, Kb of each color as the minimum luminance value. At this time, as shown in FIG. 6D, the CPU 140 instructs “pattern 0” as the insertion pattern. As can be seen from the map data in FIG. 4, “pattern 0” is intermediate frame image data for the red component and black subframe image data for the green and blue components. As shown, the red drive signal Sr becomes R intermediate frame image data Mr, the green drive signal Sg becomes G black subframe image data Kg, and the blue drive signal Sb becomes B black subframe image data Kb. As a result, as shown in FIG. 6A, image light of intermediate image data between frames is formed on the R liquid crystal light valve 10r (indicated by the letters “middle” in the figure), and the G liquid crystal Image light of G black subframe image data Kg is formed on the light valve 10g (shown by hatching in the drawing), and image light of B black subframe image data Kb is formed on the B liquid crystal light valve 10b. (Indicated by hatching in the figure).

  In the figure, T2 is the second frame period of the video signal, and is the third frame period of the video signal of T3. In each frame period T2, T3,..., Similarly to the frame period T1, the R, G, B color components included in the video signal AV, that is, the raw frame image, in the first subframe period. The image light of the data is formed as it is in each of the liquid crystal light valves 10r, 10g, and 10b, and in the second subframe period, the image light of the intermediate image data or black subframe image data corresponding to the insertion pattern is supplied to each of the liquid crystal light valves. 10r, 10g, 10b. The insertion pattern is “pattern 1” in the frame period T2 and “pattern 2” in the frame period T3. Thereafter, although not shown, “pattern 0”, “pattern 1”, and “pattern 2” are repeatedly executed in this order as the cycle progresses.

  In the embodiment configured as described above, the first frame memories 110r, 110g, and 110b correspond to the “frame memory” of the present invention, and the memory read control unit 112, the intermediate image data generation unit 120, and the signal switching unit 130. , CPU 140, second frame memories 150r, 150g, 150b, memory read control unit 152, black level generation unit 160, and inserted image data generation unit 170 correspond to the “driving image data generation unit” of the present invention, and are driven by liquid crystal. The unit 180 corresponds to the “display panel driving unit” of the present invention.

A-4. effect:
As described above, according to the projector PJ of the present embodiment, image data for one frame of each color is displayed in the first subframe period within one frame period of the video signal AV, and the one frame period is displayed. In the second subframe period, black subframe image data is displayed for two components of R, G, and B, and intermediate frame data is displayed for the remaining one component. . For this reason, the ratio of black insertion can be reduced as compared with the case where black insertion is performed on all the R, G, and B subframe image data. Therefore, it is possible to suppress a decrease in luminance, and nevertheless, it is possible to suppress motion blur due to black insertion. Further, by displaying the intermediate image data as described above, the display image can be made smoother.

  In this embodiment, the repetition cycle of the insertion pattern is set to three frame periods of the video signal, and the number of times the black subframe image data is displayed is uniform for each color component in the three frame periods. ing. The “3 frame period” here is a period obtained by adding one frame period of the video signal by the number of color components. With this configuration, the black insertion ratio can be the same for each color component.

B. Second embodiment:
FIG. 7 is a block diagram showing a part of a control unit provided in the projector in the second embodiment. In the figure, the insertion image data generation unit 270 and its periphery are shown. Although omitted in the drawing, the second embodiment similarly includes components other than the insertion image data generation unit 170 in the first embodiment.

  In the first embodiment, as described above, the inserted image data generation unit 170 stores in advance one map data for storing the relationship between the inserted pattern and each inserted image data Ir, Ig, Ib (see FIG. 4). However, instead of this, in the second embodiment, a plurality of map data are stored in advance in the library unit 272, and the inserted image data generation unit 170 stores the desired map data from the library unit 272 in the map. The data acquisition unit 270a acquires the data. For example, “map data A” and “map data B” are stored in the library unit 272. Here, “map data A” is assumed to be the same map data as in the first embodiment.

  FIG. 8 is an explanatory diagram showing the relationship between the insertion pattern for map data B and each of the insertion image data Ir, Ig, and Ib. As shown in the figure, when the insertion pattern is “pattern 0”, R, G, and B of the R intermediate frame image data Mr, the G intermediate frame image data Mg, and the B black subframe image data Kb are used. Inserted image data Ir, Ig, Ib is generated. When the insertion pattern is “pattern 1”, R, G, B insertion image data Ir, R, G, B intermediate frame image data Mg, B intermediate frame image data Mg, B Ig and Ib are generated. When the insertion pattern is “pattern 2”, R, G, and B insertion image data Ir, R, G, B, B subframe image data Kg, and B, intermediate frame image data Mb, Ig and Ib are generated.

  As a result, according to the map data A, the image display based on the black subframe image data is performed for the two components R, G, and B, and the image display based on the intermediate image data is performed for the other component. Is done. According to the map data B, image display based on black subframe image data is performed for one of R, G, and B, and image display based on intermediate image data is performed for the other two components. .

  The map data acquisition unit 270a receives the digital signal of the video signal AV from the signal conversion circuit 102, determines whether the video to be displayed is dark or bright, and based on the determination result, the map data A The map data B to be selected is determined. Specifically, the map data B is selected to reduce the black insertion ratio when it is determined to be dark, and the black insertion ratio is relatively increased when it is determined to be bright. Map data A is selected accordingly.

  Note that the determination based on the brightness of the video signal is an example, and instead, for example, other conditions such as the type of the video signal, that is, the type of personal computer input or video signal input, etc. It is good also as a structure which performs said determination by. Furthermore, it may be configured to determine which of the map data A and the map data B is selected based on information other than the video signal. Furthermore, it is good also as a structure which determines whether map data A or map data B is selected based on operation, such as a switch by an operator. In addition, although two map data are stored in the library unit 272, the number of map data is not limited to two, and more map data may be stored in advance.

  According to the second embodiment having such a configuration, similarly to the first embodiment, it is possible to suppress moving image blur due to black insertion while suppressing a decrease in luminance. Furthermore, in this embodiment, the black insertion pattern can be selected from two types based on the brightness of the video, so that the video can be of high quality.

C. Modifications of the first and second embodiments:
(I) In the first embodiment, as an insertion pattern for black insertion, black insertion is performed for two of the three components R, G, and B in the period of one frame of the video signal. The combination of components is sequentially switched as time passes. In the second embodiment, black insertion is performed for one of the three components R, G, and B in the period of one frame as an insertion pattern for black insertion. It was assumed that one component was sequentially switched over time. Instead of these, black insertion may be performed for one component or two components in two or more frame periods, and the components for performing black insertion may be sequentially switched over time.

(Ii) In the first and second embodiments, the raw frame image data is displayed in the first subframe period in one frame period of the video signal AV, and the one frame period is displayed. In the second sub-frame period, the intermediate image data or the black sub-frame image data corresponding to the insertion pattern is displayed. Instead, in the first sub-frame period, the intermediate image data or black sub-frame image data is displayed. Image data or black subframe image data may be displayed, and raw frame image data may be displayed in the second subframe period. Furthermore, a configuration may be adopted in which one frame period is divided into three (1/180 seconds) or four (1/240 seconds), and black subframe image data is displayed in the divided one subframe period.

D. Third embodiment:
In the first and second embodiments, the entire display surface has the lowest luminance in two or one of the three components R, G, and B in the second subframe period of one frame period. The black subframe image data as a value is displayed, and the image data based on the subframe image data (here, the intermediate frame image data) is displayed in the other color components. Instead, each color component The display portion (raw image data) and the non-display portion (black insertion portion) may be included in one display surface. In other words, in the first and second embodiments, black subframe image data in which black level image data indicated by a low luminance value as a black level is configured on the entire display surface is inserted. Instead, the black level data may be inserted into a part of the entire display surface. Details will be described below.

  FIG. 9 is a timing chart showing temporal changes in image light of each color in the third embodiment. In the third embodiment, as in the first and second embodiments, R, G, and B image lights are formed on the three liquid crystal light valves corresponding to the R, G, and B components, respectively. . The time change of the image light is shown in the figure.

  In the figure, T1 is the first frame period of the video signal. Also in this embodiment, with the same configuration as in the first embodiment, reading from the frame memory is performed at a double speed (1/120 seconds) of the frame period determined from the synchronization signal included in the video signal AV. Black is inserted into image data for one frame of each color obtained by this reading, that is, sub-frame image data (hereinafter also simply referred to as “raw image data”).

  As shown in FIG. 9, in the first half (first subframe period) T1a of the frame period T1, the R component has the lowest luminance value in the upper half of the first frame included in the video signal. In this figure, black is inserted (indicated by hatching in the figure. This corresponds to the non-display portion. The same applies hereinafter), and the lower half is raw image data. In the G component, the entire first frame is raw image data (corresponding to the display portion described above, and so on). In the B component, the upper half of the first frame is raw image data, and the lower half is the lowest luminance value and black is inserted. This display mode of R, G, and B components is referred to as “pattern A”.

  The video display is performed by displaying each scanning line constituting the video in order from the top to the bottom. The pixels constituting each scanning line are displayed in order from the left pixel to the right pixel. Therefore, when black is inserted in the upper half of one frame, it is converted to the lowest luminance value when each scanning line corresponding to the upper half is displayed, and black is inserted in the lower half of one frame. In the case of performing the above, when displaying each scanning line corresponding to the lower half, it is converted into the minimum luminance value and displayed. As in the first embodiment, a low luminance value as a black level may be used instead of the minimum luminance value. The portion where the black insertion is made is “black level image data” in the present invention.

  In the figure, in the latter half part (second subframe period) T1b of the frame period T1, the R half of the first frame included in the video signal is raw image data, and the lower half is Black is inserted at the lowest luminance value. In the G component, the upper half of the first frame included in the video signal has the lowest luminance value and black insertion is performed, and the lower half is raw image data. In the B component, the entire first frame is raw image data. This display mode of the R, G, and B components is referred to as “pattern B”.

  In the figure, T2 is the second frame period of the video signal. In the first sub-frame period T2a in the frame period T2, the R component includes all the second frame included in the video signal as raw image data. In the G component, the upper half of the second frame is raw image data, and the lower half is the minimum luminance value and black is inserted. In the B component, the upper half of the second frame has the lowest luminance value and black insertion is made, and the lower half is raw image data. This display mode of the R, G, and B components is referred to as “pattern C”.

  In the drawing, the display mode of the R, G, and B components in the second subframe period T2b in the frame period T2 is the “pattern A” described above. In the figure, T3 is the third frame period of the video signal. The display mode of the R, G, and B components in the first subframe period T3a in the frame period T3 is the “pattern B” described above. The display mode of the R, G, and B components in the second subframe period T3b in the frame period T3 is the above-described “pattern C”. Thereafter, “pattern A”, “pattern B”, and “pattern C” are repeatedly executed in this order as the cycle progresses.

  According to the display pattern described above, image data for one frame of each color is always displayed for all three components of R, G, and B within one frame period of the video signal. For example, in the first frame period T1, the R component and the B component display image data for one frame of each color in total in the first subframe period T1a and the second subframe period T1b. Even when the G component is reached, the image data for one frame is displayed. That is, image data for one frame of each color is displayed in total for a plurality of subframe periods included in one frame period of the video signal.

  In addition, in each sub-frame period of one frame period of the video signal, black level data is included in a part of the frame in a specific color component (for example, R component and B component in the first frame period T1). In other color components (G component in the first frame period T1) excluding a specific color component, subframe image data is displayed.

  According to the third embodiment configured as described above, the ratio of black insertion can be reduced as compared with the case where black insertion is performed on the entire screen of each color. Therefore, it is possible to suppress a decrease in luminance, and nevertheless, it is possible to suppress motion blur due to black insertion. In the present embodiment, since the black insertion is performed on a part of one screen, it is easy to meet the demand for various changes in the black insertion pattern.

  In this embodiment, one screen is divided into two equal parts and black is inserted into the upper half or the lower half, but instead, one screen is divided into three or more equal parts. It is good also as a structure which inserts black in a division part. Further, one frame period is divided into three or more subframe periods, and in each subframe period, subframe image data of a specific color component in which black insertion is applied to a part of the frame, and raw image data The displayed sub-frame image data of other color components may be displayed. Note that, as described above, instead of the configuration in which the display is performed in each of the plurality of divided subframe periods, the display may be performed in at least one of the plurality of subframe periods. Further, the sub-frame image data of the other color components is not limited to the configuration for displaying the raw image data (sub-frame image data), and image data processed based on the sub-frame image data, for example, first The intermediate image data used in the embodiment may be displayed.

E. Other variations:
(1) In the first to third embodiments, the liquid crystal light valve as the display panel is a so-called transmissive light valve. However, instead of this, a reflective light valve may be configured. Further, the display panel is not limited to a liquid crystal panel such as a liquid crystal light valve, and a micromirror type light modulation device such as DMD (digital mirror device, registered trademark of TI) may be used.

(2) In each of the above embodiments, the image signal is represented by a video signal of the three primary colors R, G, and B. However, the image signal is not necessarily limited to the three primary colors, and the video signal is represented by other color components. However, the present invention can be applied. A monochrome image may also be used. Furthermore, the present invention can also be applied to still image images instead of video signals that are moving images.

(3) The present invention is applicable to various color image display devices other than a projector. For example, the present invention can also be applied to a direct-view color image display device in which a supervisor directly views a display device, and a spatial image-type color image display device to observe an image formed in a space. Examples of the direct-view color image display device include a display for a computer, an in-vehicle small monitor, a viewfinder for a digital camera, and a display for a mobile phone. Further, as a spatial image type color image display device, there is a head mounted display.

  As mentioned above, although this invention was demonstrated based on the Example and the modification, Embodiment mentioned above is for making an understanding of this invention easy, and does not limit this invention. The present invention can be changed and improved without departing from the spirit and scope of the claims, and equivalents thereof are included in the present invention.

It is explanatory drawing which shows schematic structure of the projector PJ in 1st Example. It is a block diagram which shows the structure of control part CT. It is explanatory drawing which shows an example of prediction image data. It is explanatory drawing which shows an example of the insertion pattern which defines insertion image data Ir, Ig, and Ib. It is a flowchart which shows the control processing performed by CPU140. It is a timing chart which shows the time change of the image light of each color formed in liquid crystal light valve 10r, 10g, 10b according to control processing with the time change of various signals. It is a block diagram which shows a part of control part with which the projector in 2nd Example is equipped. It is explanatory drawing which shows an example of the insertion pattern about the map data. It is a timing chart which shows the time change of the image light of each color in the 3rd example.

Explanation of symbols

    10b ... Liquid crystal light valve, 10g ... Liquid crystal light valve, 10r ... Liquid crystal light valve, 20 ... Light source lamp, 30 ... Illumination optical system, 40 ... Dichroic mirror, 60 ... Dichroic prism, 70 ... projection lens, 102 ... signal conversion circuit, 104 ... memory write control unit, 110r ... first frame memory, 110g ... first frame memory, 110b ... ... First frame memory, 112... Memory read control unit, 120... Intermediate image data generation unit, 130... Signal switching unit, 140... CPU, 142. Frame memory, 150r ... second frame memory, 150g ... second frame memory, 150b ... second frame memory, 152 ... memory read control unit, 160 ... black level data generation , 170 ... Inserted image data generator, 180 ... Liquid Drive unit, 270 ... inserted image data generation unit, 270a ... map data acquisition unit, 272 ... library unit, PJ ... projector, OP ... projection optical system, CT ... control unit, AV ... Video signal, FLr ... Frame image data, FLg ... Frame image data, FLb ... Frame image data, SFr ... Subframe image data, SFg ... Subframe image data, SFb ... subframe image data, Kr ... black subframe image data, Kg ... black subframe image data, Kb ... black subframe image data, Mr ... intermediate frame image data, Mg .. Intermediate frame image data, Mb ... Intermediate frame image data, Sr ... Control signal, Sg ... Control signal, Sb ... Control signal

Claims (11)

A display device for displaying a color image,
A plurality of display panels corresponding to each color component of the color;
A plurality of frame memories for storing image data for one frame for each color component as frame image data of each color based on an input video signal;
A driving image data generating unit that generates driving image data for each color component based on frame image data of each color stored in each frame memory;
A display panel driving unit that drives each of the plurality of display panels based on the driving image data for each color component;
The drive image data generation unit includes:
One frame period of the video signal is divided into a plurality of subframe periods, and at least one subframe period of the plurality of subframe periods includes black level image data indicated by a low luminance value as a black level. Display of sub-frame image data of at least one specific color component and sub-frame image data of other color components excluding the specific color component including image data based on the frame image data stored in the frame memory As described above, the display device is configured to determine drive image data for each of the color components. The display device according to claim 1,
The drive image data generation unit includes:
A first output unit that outputs frame image data of each color stored in each frame memory as drive image data for each color component in a first subframe period within one frame period of the video signal When,
Black subframe image data as subframe image data of the specific color component, in which the entire display image is indicated by the low luminance value in a second subframe period within one frame period of the video signal, and display A predetermined sub-frame image data as sub-frame image data of the other color component, the entire surface of which is constituted by image data based on the frame image data stored in the frame memory, for driving each color component And a second output unit that outputs the image data. The display device according to claim 2,
A display device configured so that the number of times the black sub-frame image data is displayed is uniform for each color component in a period obtained by adding one frame period of the video signal by the number of the color components. The display device according to claim 2 or 3,
The display device, wherein the predetermined subframe image data represents an intermediate image between frames predicted from the frame image data stored in the frame memory. A display device according to any one of claims 2 to 4,
The second output unit includes:
A display device comprising: a black insertion pattern changing unit that sequentially switches a combination for selecting the specific color component from the plurality of color components as time elapses. The display device according to claim 5,
The black insertion pattern changing unit is
A map data storage unit for storing in advance a plurality of map data defining the mode of switching;
An acquisition unit that acquires one map data from the map data storage unit based on the video signal;
A switching execution unit that performs the switching according to the acquired map data. The display device according to claim 1,
The drive image data generation unit includes:
One display surface of each color component includes a display portion and a non-display portion, and the display portion is configured by a part of frame image data stored in the frame memory, and the non-display portion is the black level image. A display device configured to determine drive image data for each color component so as to be configured by data. A display method for displaying a color image on a display device including a plurality of display panels corresponding to each color component of color,
(A) storing one frame of image data for each color component as frame image data of each color based on the input video signal;
(B) generating drive image data for each color component based on the frame image data of each color;
(C) driving each of the plurality of display panels based on the driving image data for each color component, and
The step (b)
One frame period of the video signal is divided into a plurality of subframe periods, and at least one subframe period of the plurality of subframe periods includes black level image data indicated by a low luminance value as a black level. Display of sub-frame image data of at least one specific color component and sub-frame image data of other color components excluding the specific color component including image data based on the frame image data stored in the frame memory As described above, the display method is configured to determine drive image data for each of the color components. In a computer program for displaying a color image in a computer that controls a plurality of display panels corresponding to each color component,
A function of storing image data for one frame for each color component as frame image data of each color based on an input video signal;
A function of generating driving image data for each color component based on the frame image data of each color;
A function of driving each of the plurality of display panels based on the driving image data for each color component; and
The function of generating the driving image data is as follows:
One frame period of the video signal is divided into a plurality of subframe periods, and at least one subframe period of the plurality of subframe periods includes black level image data indicated by a low luminance value as a black level. Display of sub-frame image data of at least one specific color component and sub-frame image data of other color components excluding the specific color component including image data based on the frame image data stored in the frame memory As described above, a computer program having a configuration for determining driving image data for each color component. A computer program according to claim 9,
The function of generating the driving image data is as follows:
A function of outputting frame image data of each color stored in each frame memory as drive image data for each color component in a first sub-frame period of one frame period of the video signal;
Black subframe image data as subframe image data of the specific color component, in which the entire display image is indicated by the low luminance value in a second subframe period within one frame period of the video signal, and display A predetermined sub-frame image data as sub-frame image data of the other color component, the entire surface of which is constituted by image data based on the frame image data stored in the frame memory, for driving each color component A computer program having a function of outputting as image data. A computer program according to claim 9,
The function of generating the driving image data is as follows:
One display surface of each color component includes a display portion and a non-display portion, and the display portion is configured by a part of frame image data stored in the frame memory, and the non-display portion is the black level image. A computer program having a configuration for determining driving image data for each color component so as to be configured by data.

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