JP2012068282A - Image display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image display device capable of improving the luminance of a display image.SOLUTION: The image display device includes a display part displaying an image and a display control part controlling the operation of the display part and updating the image displayed on the display part in the order of a first image, a black image, a second image, and the black image. The display control part makes the respective display periods TL and TR of the first image and the second image longer than the display period TB of the black image.

Description

  The present invention relates to an image display device.

2. Description of the Related Art Conventionally, there has been known an image display system that includes an image display device that displays an image and shutter glasses worn by an observer, and stereoscopically displays a display image displayed on the image display device through the shutter glasses ( For example, see Patent Document 1).
The image display device described in Patent Document 1 is configured by a liquid crystal display that displays an image by line sequential driving. The liquid crystal display updates the image to be displayed in the order of the left-eye image, the black image, the right-eye image, and the black image for each vertical scanning period specified by the vertical synchronization signal.
That is, in the image display device described in Patent Literature 1, the time for the frames of the left-eye image and the right-eye image to overlap each other is eliminated by inserting the black-image frame between the left-eye image and right-eye image frames ( (Crosstalk is prevented) and the displayed image is stereoscopically viewed.

JP 2009-232249 A

  However, in the image display device described in Patent Document 1, by inserting the black image frame between the left-eye image and the right-eye image, the time for visually recognizing the left-eye image and the right-eye image is reduced. There is a problem that the brightness of the display image is reduced.

  The objective of this invention is providing the image display apparatus which can improve the brightness | luminance of a display image.

The image display device of the present invention includes a display unit that displays an image, and a display control unit that updates an image to be displayed on the display unit in the order of the first image, the black image, the second image, and the black image, The display control unit makes each display period of the first image and the second image longer than a display period of the black image.
Here, the display period of the black image means a period from the update start timing of the black image to the update start timing of the next first image or second image.
The display period of the first image means a period from the update start timing of the first image to the update start timing of the next black image. The same applies to the display period of the second image.
According to the present invention, since the display control unit makes each display period of the first image and the second image longer than the display period of the black image, the black image is inserted between the first image and the second image. It is possible to lengthen the time during which the first image and the second image can be visually recognized while eliminating the time when the first image and the second image overlap.
Therefore, the brightness of the display image can be improved.

In the image display device of the present invention, the display control unit drives the display unit line-sequentially, updates an image to be displayed on the display unit every vertical scanning period, and starts the black image from the start point of the vertical scanning period. It is preferable that the period until the update start timing is longer than the period from the start point of the vertical scanning period to the update start timings of the first image and the second image.
In the present invention, by appropriately setting a period called a so-called front porch (a period from the start time of the vertical scanning period to the update start timing of the image), the display control unit displays each of the first image and the second image. The period is set longer than the black image display period.
Accordingly, the display periods of the black image, the first image, and the second image can be adjusted with simple processing, and the processing load on the display control unit can be reduced.

In the image display device according to the aspect of the invention, the display control unit starts updating the first image and the second image at an update start timing substantially coincident with a start time of the vertical scanning period, and the update of the black image is completed. It is preferable to start updating the black image at an update start timing whose timing substantially coincides with the start time of the next vertical scanning period.
According to the present invention, the display control unit starts updating the black image, the first image, and the second image at the timing described above.
This makes it possible to maximize each display period of the first image and the second image while updating the first image, the black image, the second image, and the black image in this order in each vertical scanning period. The period can be minimized.
Therefore, the time during which the first image and the second image can be viewed can be maximized, and the brightness of the display image can be effectively improved.

The perspective view which shows the usage type of the image display system in this embodiment. The block diagram which shows typically the structure of the image display system in this embodiment. FIG. 5 is a diagram for explaining a method of driving a liquid crystal panel in the present embodiment. The figure for demonstrating operation | movement of the image display system in this embodiment.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
[1. Configuration of image display system)
FIG. 1 is a perspective view showing a usage pattern of the image display system 1.
FIG. 2 is a block diagram schematically showing the configuration of the image display system 1.
The image display system 1 displays a projected image on a reflective screen Sc (FIG. 1) and causes an observer to stereoscopically view the projected image. As shown in FIG. 1 or 2, the image display system 1 includes a projector 2 as an image display device and shutter glasses 3.

[2. Projector configuration)
The projector 2 forms an image based on the image information (image data) and projects it on the screen Sc. As shown in FIG. 1 or FIG. 2, the projector 2 includes an exterior housing 2A (FIG. 1) constituting an exterior, an optical unit 2B (FIG. 2) and a control device 2C (FIG. 2) housed in the exterior housing 2A. 2).
Although not specifically shown, the optical unit 2B projects a light source unit, a liquid crystal panel 21 (FIG. 2) as a display unit that forms an image by modulating light emitted from the light source unit, and an image. It has a projection lens 22 (FIG. 1).

The control device 2C includes a CPU (Central Processing Unit) and the like, and controls operations of the liquid crystal panel 21 and the shutter glasses 3. As shown in FIG. 2, the control device 2 </ b> C includes an image ROM (Read Only Memory) 23, a timing controller 24, a display control unit 25, a memory 26, and a transmission unit 27.
The image ROM 23 stores image data to be formed on the liquid crystal panel 21.
Here, the image data includes left-eye image data related to the left-eye image as the first image, right-eye image data related to the right-eye image as the second image, and black image data related to the black image. Each of these image data is constituted by a collection of data for each frame.
The timing controller 24 reads a synchronization signal (vertical synchronization signal, horizontal synchronization signal) included in the image data stored in the image ROM 23 and synchronizes the display control unit 25 and the transmission unit 27.

FIG. 3 is a schematic diagram for explaining a driving method of the liquid crystal panel 21.
The display control unit 25 appropriately reads out the image data stored in the image ROM 23, performs predetermined processing on the image data, and then drives the liquid crystal panel 21 line-sequentially to display an image based on the image data. .
Specifically, the display control unit 25 is based on the synchronization signal output from the timing controller 24 and the information stored in the memory 26, as shown in FIG. The image data is sequentially written to each pixel from the scanning line L (L1) to the lowest scanning line L (Ln) (a voltage corresponding to the gradation is applied), and the image displayed on the liquid crystal panel 21 is updated. Then, the display control unit 25 performs the same processing as described above within the next vertical scanning period, and updates the next image.

The memory 26 stores first timing information and second timing information related to the writing start timing (update start timing) to the uppermost scanning line L1 by the display control unit 25.
The first timing information corresponds to a period called a so-called front porch, and the writing start timing of image data relating to the “left-eye image or right-eye image” to the scanning line L1 from the output timing of the vertical synchronization signal from the timing controller 24. It is the information regarding the period (henceforth a 1st period) until.
Similarly, the second timing information corresponds to a period called a so-called front porch, and is a period from the output timing of the vertical synchronization signal to the writing start timing of image data relating to the “black image” to the scanning line L1 (hereinafter referred to as the second timing information). Period).

The transmission unit 27 transmits a control signal for switching a later-described left-eye selection unit 31 and right-eye selection unit 32 constituting the shutter glasses 3 to a transmission state or a cutoff state, and a signal related to the switching timing.
Here, the transmission unit 27 generates a signal related to the switching timing based on the synchronization signal output from the timing controller 24 and the first timing information stored in the memory 26. That is, the signal related to the switching timing corresponds to a signal related to the writing start timing of the image data related to the “left-eye image or right-eye image” from the output timing of the vertical synchronization signal to the scanning line L1.
In the present embodiment, the transmitter 27 is not specifically shown, but includes an infrared light emitting LED (Light Emitting Diode), a drive circuit for causing the infrared light emitting LED to emit light, and the like. Send by changing the time and light emission pattern.

[3. (Configuration of shutter glasses)
The shutter glasses 3 are worn by an observer. As shown in FIG. 1 or FIG. 2, the left eye selection unit 31, the right eye selection unit 32, the reception unit 33 (FIG. 2), and a shutter drive unit. 34 (FIG. 2).

The left-eye selection unit 31 and the right-eye selection unit 32 are configured by so-called liquid crystal shutters, and are in a blocking state in which light is blocked by an ON signal input (voltage application state) and an OFF signal input (voltage non-application state). , And switched to a transmission state that transmits light.
In the present embodiment, as described above, the left-eye selection unit 31 and the right-eye selection unit 32 use a TN (Twisted Nematic) liquid crystal that switches to a blocking state when an ON signal is input and to a transmission state when an OFF signal is input. ing.
The receiving unit 33 receives the signal transmitted from the transmitting unit 27.
In the present embodiment, the receiving unit 33 is not specifically illustrated, but includes an infrared light receiving element and the like, receives the infrared light emitted from the transmitting unit 27 and converts it into a signal, and the shutter driving unit 34. Output to.
The shutter drive unit 34 outputs an ON signal and an OFF signal to the left eye selection unit 31 and the right eye selection unit 32 based on the signal from the reception unit 33, and is transmitted through the left eye selection unit 31 and the right eye selection unit 32. Switch between state and block state.

[4. Operation of image display system)
FIG. 4 is a diagram for explaining the operation of the image display system 1.
Specifically, FIG. 4A is a timing chart showing the writing timing of image data to the scanning lines L1 to Ln of the liquid crystal panel 21, and the vertical direction of the liquid crystal panel 21 (the scanning lines L1 to Ln). Position) is the vertical axis. FIG. 4B is a timing diagram illustrating the switching timing of the transmission state and the blocking state in the left-eye selection unit 31 (lower stage in FIG. 4B) and the right-eye selection unit 32 (upper stage in FIG. 4B). It is a chart.
In FIG. 4A, in order to schematically show the writing timing of the image data to each of the scanning lines L1 to Ln, the writing start timing (update start timing) for starting the writing of the image data to the scanning line L1. ) Ws and a write completion timing (update completion timing) We for completing the writing of the image data to the scanning line Ln are connected by a straight line. In FIG. 4A, for convenience of explanation, symbols “L” and “R” are added to the left-eye image and the right-eye image, respectively, and the black image is displayed as the image displayed on the liquid crystal panel 21. It is indicated by diagonal lines (each of the left eye image, the right eye image, and the black image is a parallelogram area).

Next, the operation of the above-described image display system 1 will be described with reference to FIG.
In the following, for convenience of explanation, as the operation of the image display system 1, the operation of the projector 2 and the operation of the shutter glasses 3 will be described in order.

[4-1. Projector operation)
The control device 2C controls the operation of the liquid crystal panel 21 as described below.
That is, the display control unit 25 reads the left-eye image data from the image ROM 23 and updates the image to be displayed on the liquid crystal panel 21 to the left-eye image within the vertical scanning period Tv1 (FIG. 4A).
Specifically, as shown in FIG. 4A, the display control unit 25 performs the first stored in the memory 26 from the output timing V of the vertical synchronization signal from the timing controller 24 (starting point of the vertical scanning period Tv1). Writing of the image data for the left eye to the scanning line L1 is started at the writing start timing Ws (WsL) when the first period based on the timing information has elapsed.
In the present embodiment, the first period is set to a minimum value (substantially 0). For this reason, the write start timing WsL substantially matches the output timing V of the vertical synchronization signal.

Further, in the next vertical scanning period Tv2 (FIG. 4A), the display control unit 25 reads black image data from the image ROM 23 and updates the image to be displayed on the liquid crystal panel 21 to a black image.
Specifically, the display control unit 25 writes the write start timing Ws when the second period based on the second timing information stored in the memory 26 has elapsed from the output timing V of the vertical synchronization signal (the start time of the vertical scanning period Tv2). Writing of black image data to the scanning line L1 is started at (WsB).
In the present embodiment, the second period is set to a maximum value that is longer than the first period. That is, as the second period, the writing completion timing We (WeB) for completing the writing of the black image data to the lowermost scanning line Ln is the start point of the next vertical scanning period Tv3 (FIG. 4A) ( It is set so that it substantially coincides with the output timing V of the vertical synchronizing signal (a period called a so-called back porch has a minimum value (substantially 0)).

Further, in the next vertical scanning period Tv3 (FIG. 4A), the display control unit 25 reads the right-eye image data from the image ROM 23 and updates the image displayed on the liquid crystal panel 21 to the right-eye image.
Specifically, the display control unit 25, like the above-described update of the left-eye image, has passed the first period (substantially the output timing V) from the output timing V of the vertical synchronization signal (the start time of the vertical scanning period Tv3). Writing of the image data for the right eye to the scanning line L1 is started at the writing start timing Ws (WsR) that coincides).
In the next vertical scanning period Tv4 (FIG. 4A), the display control unit 25 updates the image to be displayed on the liquid crystal panel 21 to a black image in the same manner as the black image update described above.
That is, as shown in FIG. 4A, the display control unit 25 displays each display period TL, TR (write start timings WsL, WsR to write start timing WsB from the left eye image and the right eye image). ) Is longer than the black image display period TB (period from the write start timing WsB to the write start timing WsL (WsR)).
As described above, the display control unit 25 displays the image to be displayed on the liquid crystal panel 21 for each of the vertical scanning periods Tv1 to Tv4 (1/240 (seconds in the present embodiment)) for the left-eye image, the black image, and the right-eye image. Update in order of image, black image.

  In addition, the transmission unit 27 includes a control signal for controlling the shutter glasses 3 and a signal related to the switching timing (writing) based on the synchronization signal output from the timing controller 24 and the first timing information stored in the memory 26. Start signals WsL and WsR).

[4-2. Operation of shutter glasses)
The shutter driving unit 34 recognizes the switching timing of the transmission state and the blocking state of the left-eye selection unit 31 and the right-eye selection unit 32 based on the signal from the reception unit 33.
Then, as shown in the lower part of FIG. 4B, the shutter drive unit 34 has a switching timing S1 that substantially matches the writing start timing WsL (the start time of the vertical scanning period Tv1 (the output timing V of the vertical synchronization signal)). An OFF signal is output to the left-eye selection unit 31, and the left-eye selection unit 31 is switched from the blocking state CL to the transmission state OP.
On the other hand, as shown in the upper part of FIG. 4B, the shutter drive unit 34 outputs an ON signal to the right eye selection unit 32 at the switching timing S1, and switches the right eye selection unit 32 from the transmission state OP to the cutoff state CL. .

Further, as shown in the lower part of FIG. 4B, the shutter drive unit 34 has a switching timing S2 that substantially matches the writing start timing WsR (the start time of the vertical scanning period Tv3 (the output timing V of the vertical synchronization signal)). An ON signal is output to the left-eye selector 31 to switch the left-eye selector 31 from the transmission state OP to the cutoff state CL.
On the other hand, as shown in the upper part of FIG. 4B, the shutter drive unit 34 outputs an OFF signal to the right-eye selection unit 32 at the switching timing S2, and switches the right-eye selection unit 32 from the blocking state CL to the transmission state OP. .

With the above operation, in the vertical scanning periods Tv1 and Tv2, the left-eye selection unit 31 is in the transmission state OP and the right-eye selection unit 32 is in the blocking state CL. The black image) is visually recognized only by the left eye of the observer.
In the vertical scanning periods Tv3 and Tv4, the right-eye selection unit 32 is in the transmission state OP and the left-eye selection unit 31 is in the blocking state CL, so that the projected image (right-eye image and black image) on the screen Sc. Is visually recognized only by the right eye of the observer.
For this reason, the observer stereoscopically views the projection image on the screen Sc by parallax.

According to this embodiment described above, the following effects are obtained.
In the present embodiment, the display control unit 25 makes the display periods TL and TR of the image for the left eye and the image for the right eye longer than the display period TB of the black image.
This makes it possible to lengthen the time during which the image for the left eye and the image for the right eye can be visually recognized while inserting the black image between the image for the left eye and the image for the right eye to eliminate the overlap time of the image for the left eye and the image for the right eye, It is possible to improve the brightness of the projected image that is viewed stereoscopically by the observer.

In addition, by appropriately setting the so-called front porch periods (first period and second period), the display control unit 25 displays the display periods TL and TR of the left-eye image and the right-eye image as black images. It is longer than the period TB.
Thus, the display periods TB, TL, TR of the black image, the left eye image, and the right eye image can be adjusted with simple processing, and the processing load on the display control unit 25 can be reduced.

Furthermore, the first period is set to the minimum value, and the second period is set to the maximum value.
As a result, the display periods TL and TR for the left-eye image and the right-eye image are maximized while updating the left-eye image, the black image, the right-eye image, and the black image in this order for each of the vertical scanning periods Tv1 to Tv4. And the black image display period TB can be minimized.
Accordingly, it is possible to maximize the time during which the left-eye image and the right-eye image can be viewed, and to effectively improve the brightness of the projected image that is stereoscopically viewed by the observer.

It should be noted that the present invention is not limited to the above-described embodiments, and modifications, improvements, and the like within the scope that can achieve the object of the present invention are included in the present invention.
In the embodiment described above, the image display system 1 is configured to cause the viewer to stereoscopically display the display image using the first image and the second image as the left-eye image and the right-eye image, respectively, but is not limited thereto. For example, the image display system may employ a configuration in which the first image and the second image are images having different contents and the two display images (first image and second image) are visually recognized by different observers. .
In the case of such a configuration, the shutter glasses 3 may be provided with two types of glasses, that is, glasses with left-eye selection unit 31 provided on the left and right and glasses with right-eye selection unit 32 provided on the left and right.

  In the embodiment, the first period is set to the minimum value and the second period is set to the maximum value. However, if the second period is longer than the first period, the first period and the second period are set as in the embodiment. The second period may not be set.

In the above-described embodiment, only the example in which the front projection type projector 2 is employed as the image display device has been described. However, the present invention employs a rear type projector that includes a screen and performs projection from the back side of the screen. It does not matter as a configuration.
In the embodiment, the projector 2 is employed as the image display device. However, the present invention is not limited thereto, and a liquid crystal display, a plasma television, an organic EL (Electro-Luminescence) display, or the like may be employed.

  The present invention can be used for an image display system that stereoscopically displays an image using an image display device such as a projector or shutter glasses.

  2 ... projector (image display device), 21 ... liquid crystal panel (display unit), 25 ... display control unit, TB, TL, TR ... display period, Tv1-Tv4 ... vertical scanning period , Ws... Write start timing (update start timing).

Claims (3)

A display for displaying an image;
A display control unit that controls the operation of the display unit and updates an image to be displayed on the display unit in the order of the first image, the black image, the second image, and the black image;
The display control unit
Each display period of the said 1st image and said 2nd image is made longer than the display period of the said black image. The image display apparatus characterized by the above-mentioned. The image display device according to claim 1,
The display control unit
The display unit is line-sequentially driven, an image displayed on the display unit is updated every vertical scanning period, and a period from the start of the vertical scanning period to the update start timing of the black image is started. An image display device characterized in that it is longer than a period from the time point to the update start timing of each of the first image and the second image. The image display device according to claim 2,
The display control unit
Start updating the first image and the second image at an update start timing substantially coincident with the start time of the vertical scanning period;
The black image update start timing is started at an update start timing at which the update completion timing of the black image substantially coincides with the start time of the next vertical scanning period.

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