JP2001157229A - Video display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a video display device by which a user can view an image with apparently higher resolution than the resolution of a display element by applying an optical pixel shift to a video signal that is standardized such as a video signal of the NTSC system and a specific video signal for a game machine or the like. SOLUTION: The video display device is configured with a wobbling unit 6 consisting of a 1st liquid crystal shutter 11 that alternately provides either of polarized lights in two orthogonal directions from a light from an LCD 4 in response to an ON/OFF state, of 1st and 2nd double refraction plates 12, 13 that deviate an optical path of the light from the shutter, a 2nd liquid crystal shutter 14 and of a 3rd double refraction plate 15, and with a pixel shift method selection switch section 5 that generates a liquid crystal shutter drive control signal for a mode where the 1st and 2nd liquid crystal shutters are switched at different frequencies and generates a liquid crystal shutter drive control signal for a mode where the 1st and 2nd liquid crystal shutters are switched at the same frequency.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention performs an optical pixel shifting operation in response to a standard TV video signal such as an NTSC system, a special video signal such as a game machine video signal, and a three-dimensional (stereo) video signal. Accordingly, the present invention relates to a video display device capable of observing an image having a resolution apparently higher than the resolution of a display element.

[0002]

2. Description of the Related Art Conventionally, in an image display device using a liquid crystal display device or the like, a pixel shift operation called wobbling for oscillating the optical axis of light from the liquid crystal display device in a predetermined direction is performed to obtain the resolution of the liquid crystal display device. It is known to improve apparently.

For example, Japanese Patent Application Laid-Open No. 4-63332 discloses that a liquid crystal panel for display uses two sets of a combination of a liquid crystal panel for controlling the polarization direction and a quartz plate and one set using four frame memories. The image is shifted by 1/2 pixel pitch in the horizontal direction by the polarization direction control liquid crystal panel and the crystal plate, and the image is shifted by 1/2 pixel pitch in the vertical direction by another set of polarization direction control liquid crystal panel and the crystal plate. In this case, a method of shifting the pixel by four points to improve the resolution is shown. That is, one frame is composed of four fields, an image signal is divided into four images, and each divided image is stored in the frame memory. Then, in the first field, the display is made to go straight through the two sets of liquid crystal panels,
In the second field, the display is shifted in the horizontal direction by a half pixel pitch, in the third field, the display is shifted in the vertical direction by a half pixel pitch, and in the fourth field, the display is shifted in the horizontal and vertical directions. Both images are displayed at positions shifted by a half pixel pitch, and by combining them, a high-definition image is displayed by shifting four pixels.

In Japanese Patent Application Laid-Open No. Hei 7-36054, two sets of one-dimensional two-point pixel shift elements each composed of a liquid crystal phase modulation element and a birefringent medium are prepared, and one element is used for the other element. Rotate 90 degrees about the incident optical axis and combine and stack them to perform four pixel shifts in the vertical and horizontal directions within one frame or one field, and perform two-dimensional pixel shift.
An optical device that obtains a high-resolution image by shifting a point pixel is disclosed.

In each of the above prior arts, the pixels of a liquid crystal display element having a square arrangement with a horizontal pixel pitch P _X and a vertical pixel pitch P _Y are reduced by half in the horizontal, vertical and oblique directions.
The present invention relates to a device in which the resolution is increased four times by shifting the pixel pitch by four pixels.

By the way, when the above four-point pixel shift method is simply applied to a commonly used liquid crystal display element in which pixels are arranged in a delta arrangement and four-point pixel shift is performed,
The frequency band increases in the vertical and diagonal directions,
There is a problem that the horizontal frequency band does not increase at all even if the four-point pixel shift is performed, and the horizontal resolution does not improve.

To solve this problem, the applicant of the present application
First, in JP-A-10-336482, a pixel is
Display elements arranged in a data array, and each pixel position of the display elements
Pixel position change which repeatedly shifts each of the four points
Shifting means and the pixel position in synchronization with the pixel position shifting means.
Image signal for displaying an image corresponding to the position on the display element.
Image shifting means for shifting the pixel positions of the four pixels.
The position is a standard first pixel position and the standard first pixel position
The horizontal pixel pitch P in the horizontal direction_XAbout 1/2 of
The displaced second pixel position and the standard first pixel position
, The horizontal pixel pitch P in the horizontal direction_XAbout 3/4 or
About 1/4, vertical pixel pitch P in the vertical direction _YAbout 1/2 of
A displaced third pixel position and the standard first pixel position
, The horizontal pixel pitch P in the horizontal direction_XAbout 1/4 of
About 3/4, vertical pixel pitch P in the vertical direction_YAbout 1/2 of
Image display configured as four points at shifted fourth pixel positions
The device was proposed.

According to the proposed image display device, the frequency band increases both in the vertical and horizontal directions, and the resolution can be doubled not only in the vertical direction but also in the horizontal direction.

[0009]

By the way, any of those disclosed in the above-mentioned publications or those previously proposed are NT
It is intended to display images based on standardized standard TV video signals such as the SC system and the PAL system, and to display these images as high-resolution images by a wobbling system, such as the NTSC signal and the PAL signal. Applying a high-definition method by wobbling to an image based on a special video signal such as a game machine video signal or a three-dimensional video signal other than a standardized standard TV video signal, for example, a PlayStation (product name). There is no disclosure of any such method, and no proposal has yet been made for a high-definition system which can commonly cope with the standardized standard TV video signal and special video signal. Absent.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem in the conventional video display apparatus. The invention according to claim 1 is a method of using a wobbling mode for shifting four pixels having different shift orders in the same optical system. It is another object of the present invention to provide a video display device capable of achieving high resolution of a different input video signal by a wobbling operation. Another object of the present invention is to provide a video display device capable of achieving high resolution by wobbling operation of a four-point pixel shift method and a two-point pixel shift method with the same optical system. And A third object of the present invention is to provide a video display device which can simplify the configuration of the optical block control means and can make the response characteristics of the modulation elements of each optical block uniform. Another object of the present invention is to make a black matrix inconspicuous in a video display device capable of observing an image having a high apparent resolution only in the horizontal direction. It is another object of the present invention to provide a video display device capable of observing a stereo image from which a stronger stereoscopic effect can be obtained. It is another object of the present invention to provide a video display device capable of efficiently observing a stereo image. Another object of the present invention is to provide an image display device capable of accurately performing high definition by shifting pixels in a horizontal direction with respect to a stereo image.

[0011]

In order to solve the above-mentioned problems, the invention according to claim 1 provides an optical shift for a light beam emitted from each pixel of a display element corresponding to an input video signal. A video display device capable of performing pixel shift by performing the image display and observing an image having a resolution apparently higher than the resolution of the display element, wherein the polarization emitted from the display element is polarized on two polarization planes orthogonal to each other. And an optical block including at least one birefringent medium having a crystal axis substantially parallel to one of the two polarization planes of the polarized light emitted from the modulation element. A mode in which each modulation element of the optical block is switched at a different frequency according to the type of the input video signal; and a mode in which each modulation element of the optical block is the same. And it is characterized in that it comprises a means for switching to a mode for switching at a frequency of.

As described above, by providing the means for switching between the mode of switching each modulation element of the optical block at a different frequency and the mode of switching at the same frequency according to the type of the input video signal, two sets of optical blocks are provided. Can be provided with a four-point pixel shift wobbling mode having a different shift order in the same optical system, and therefore, it is possible to increase the resolution of different types of input video signals by a wobbling operation.

According to a second aspect of the present invention, a light beam emitted from each pixel of the display element is optically shifted to perform pixel shift, and an image having a resolution apparently higher than the resolution of the display element is observed. A modulating element for switching polarized light emitted from the display element to polarized light of two polarization planes orthogonal to each other and emitting the polarized light, and two polarized lights related to polarized light emitted from the modulating element. Two sets of optical blocks each including at least one birefringent medium having a crystal axis substantially parallel to one of the polarization planes of the plane, and light rays emitted from each pixel of the display element are shifted by four pixels. In some cases, the light beam is
One optical block selects whether to optically shift or to pass the light as it is, and shifts the four pixels by a combination of the selections, and shifts the light rays emitted from each pixel of the display element to two positions. In this case, one of the two optical blocks passes the light beam as it is, and the other optical block selects whether to perform an optical shift or pass the light beam as it is. And an optical block control means for effecting pixel shift.

By providing such an optical block control means, it is possible to achieve a high resolution by wobbling operation of the four-point pixel shift method and the two-point pixel shift method in the same optical system composed of two sets of optical blocks. .

According to a third aspect of the present invention, in the video display device according to the second aspect, the optical block control means controls each of the modulation elements in each of the optical blocks with two drive signals having the same period, Each of the optical blocks is configured such that the light emitted from each pixel of the display element when the drive signal is supplied to each of the modulation elements can be shifted to four or two points by a pixel. The birefringent medium is arranged and configured. As described above, since each modulation element in each optical block is controlled by two drive signals having the same period, the electric circuit configuration of the optical block control means can be simplified, and the response characteristic of the modulation element can be improved. Can also be aligned between the two optical blocks.

According to a fourth aspect of the present invention, a light beam emitted from each pixel of the display element is optically shifted to shift the pixel to four points corresponding to the vertices of the quadrangle, thereby providing a resolution of the display element. A video display device capable of observing an image whose resolution is apparently higher only in the horizontal direction than in the information of each pixel at the four point positions after the pixel shift, the two point positions being substantially adjacent in the vertical direction. And the pixel shift order to the two substantially vertically adjacent pixel positions in the four-point pixel shift operation is configured to be continuous with each other. Things.

With such a configuration, in a video display device capable of observing an image having an apparent high resolution only in the horizontal direction, a black line portion which is usually seen every other line is almost vertically adjacent. Since the pixel information of the pixel can be displayed, it is possible to observe an image in which a black matrix without a black line is inconspicuous.

According to a fifth aspect of the present invention, there is provided a receiving means for receiving a stereo video signal transmitted in a video signal period of one frame in which a left-eye video signal and a right-eye video signal are successively transmitted at a temporally forward and backward position. Sampling means for sampling the received stereo video signal at different sampling timings for each frame, and displaying a left-eye video on a left-eye display element among stereo video signals sampled by the sampling means, Display means for displaying the image for the eye on the display element for the right eye, and the display means for the display element for the left eye and the display element for the right eye, respectively, and emitted from the pixels of the display element for the left eye and the display element for the right eye An optical unit for optically shifting the reflected light, the optical unit switching the polarization to two planes of polarization orthogonal to each other. An optical block set comprising a modulation element to be emitted and at least one birefringent medium having a crystal axis substantially parallel to one of two polarization planes of polarized light emitted from the modulation element. The image display device is configured so as to perform pixel shift at least in the horizontal direction of the display means.

With this configuration, the horizontal resolution of the display element for the left eye and the display element for the right eye can be increased, whereby the resolution of parallax is improved, and an image with a stronger stereoscopic effect can be obtained. Can be observed.

According to a sixth aspect of the present invention, in the video display device according to the fifth aspect, the display means is configured such that, during a period of the one frame, during a period in which a left-eye video signal is transmitted,
The display element for the left eye and the optical block for the left eye act so that the transmitted video signal for the left eye can be observed, and the display element for the right eye and the optical block for the right eye are transmitted immediately before. The right-eye video signal acts to hold the right-eye video signal of the frame so as to be observable, and during the one-frame period, the right-eye display element and the right-eye optical block are transmitted during the period in which the right-eye video signal is transmitted. Is configured so that the transmitted right-eye video signal is observable, and the left-eye display element and the left-eye optical block are configured to operate such that the left-eye video signal of this frame is observable. It is characterized by having been done. This embodiment corresponds to the embodiment shown in FIGS.

By configuring the display means in this manner, it is possible to efficiently observe a stereo image without requiring separate control means for the left-eye and right-eye video signals.

According to a seventh aspect of the present invention, in the video display apparatus according to the fifth aspect, the sampling means performs sampling of two frames adjacent on the time axis by setting a phase of a sampling point to a half cycle. It is characterized in that it is configured to be shifted.
This embodiment corresponds to the embodiment shown in FIGS. By shifting the position of the sampling point by 周期 cycle in this manner, a video signal for horizontal pixel shift obtained by sampling at a different sampling timing for each frame can be obtained with high accuracy, and the accuracy of the stereo video signal can be improved. Good high definition can be achieved.

[0023]

Next, an embodiment will be described. FIG. 1 is a schematic block diagram showing an embodiment of a video display device according to the present invention. In FIG. 1, 1 is N
A decoder for receiving an input video signal such as a TSC video signal or a video signal of a game machine and separating and converting the video signal into an RGB signal; 2, a memory, an arithmetic unit, an A / D converter,
A signal processing unit comprising a D / A converter or the like for performing sampling processing, image processing, etc., 3 is an LCD driver for sending out a drive signal for driving an LCD as a display element, and 4 is for displaying an image based on an input video signal. The LCD 5 is a pixel shifter for selectively generating a liquid crystal shutter control signal for ON / OFF-controlling a liquid crystal shutter of a wobbling unit described later for selecting a pixel shift method based on a timing signal from the signal processing circuit 2. A method selection switch unit 6 is a wobbling unit arranged on the display surface of the LCD 4 for performing a two-point pixel shift or a four-point pixel shift operation on the display image of the LCD 4.

The LCD 4 in the above embodiment is
As shown in FIG. 2, for example, in a two-dimensional shape such as a delta array
It is configured to have a plurality of pixels 4a arranged regularly.
You. This delta arrangement allows the horizontal pitch between pixels to be
P_X, Vertical pitch is P _YThen, the odd pixel array
In the horizontal direction, P_XNot only / 2
It is an array that has been made. A backlight (not shown)
The light emitted from the LCD 4 and emitted from the LCD 4
Is polarized in one direction.
In the embodiment, the angle is 45 ° from the upper left to the lower right.
The polarized light is emitted.

Next, a configuration example of the wobbling unit 6 in the above embodiment will be described with reference to FIG. As shown in FIG. 3, the configuration example of the wobbling unit is such that light emitted from the LCD 4 is changed according to the ON / OFF state of the LCD 4 configured to emit light polarized in an oblique direction of 45 °. A first liquid crystal shutter 11 as a modulating element composed of a TN liquid crystal cell for switching to polarization in two directions orthogonal to each other, and an optical path of light polarized in one direction among the light passing through the first liquid crystal shutter 11 A first birefringent plate 12, which is a birefringent medium, and a birefringent plate, which shifts the optical path of light polarized in the other direction of the light passing through the first liquid crystal shutter 11 to different positions on the same horizontal plane. Modulation comprising a second birefringent plate 13 as a refracting medium, and a TN liquid crystal cell for switching light passing through the second birefringent plate 13 into two orthogonal polarizations according to the ON / OFF state. The second liquid crystal shutter as an element And a third birefringent plate 15 that is a birefringent medium that shifts the optical path of light polarized in one direction out of the light that has passed through the second liquid crystal shutter 14.

In the wobbling unit 6, the first liquid crystal shutter 11, the first birefringent plate 12, and the second birefringent plate 13 constitute a horizontal pixel shift unit as a first optical block. The second liquid crystal shutter 14 and the third birefringent plate 15 constitute an oblique pixel shift unit which is a second optical block.

Further, as shown in FIG. 3, the crystal axis of each of the birefringent plates is formed so as to form an angle of 45 ° with respect to the thickness direction (z-axis direction). X axis
The direction when projected on the y-plane is such that the first birefringent plate 12 has a crystal axis direction obliquely downward to the right, the second birefringent plate 13 has a crystal axis direction obliquely downward to the left, and a third birefringent plate. Reference numeral 15 indicates the crystal axis direction obliquely upward to the right.

Next, how the apparent position of the pixel on the LCD 4 is changed by the wobbling unit 6 configured as described above will be described. LCD4
For example, it is assumed that light having a 45 ° oblique polarization direction from the upper left to the lower right as shown in FIG. 3 is emitted. When such light enters the first liquid crystal shutter 11, the first liquid crystal shutter 11
The liquid crystal shutter 11 switches the polarization direction of the light in accordance with the ON / OFF state. Specifically, when the liquid crystal shutter 11 is turned on, the light is polarized at an oblique angle of 45 ° from the upper left to the lower right (hereinafter referred to as the first polarization). When the light is turned off, the light is converted into oblique 45 ° polarized light (hereinafter, referred to as second polarized light) from the upper right to the lower left (hereinafter, referred to as second polarized light) and passed.

Subsequently, the light is incident on the first birefringent plate 12. The first birefringent plate 12 has a crystal axis direction from the upper left to the lower right, and shifts the optical path of the first polarized light of the incident light in a diagonally lower right direction as shown in FIG. The second polarized light is passed almost as it is.

Next, light enters the second birefringent plate 13.
The second birefringent plate 13 has a crystal axis direction from the upper right to the lower left as shown in FIG. 3, and the optical path of the second polarized light of the incident light is shown in FIG. As shown, the light is shifted diagonally downward to the left, and the first polarized light is passed almost as it is.

Further, light enters the second liquid crystal shutter 14. This second liquid crystal shutter 14 is also a first liquid crystal shutter.
As in the case of 11, the polarization direction of the light is switched in accordance with the ON / OFF state. Specifically, when the light is turned on, the light is passed without changing the polarization, and when the light is turned off, the light is polarized. The polarized light is converted in the orthogonal direction and passed.

As a result, as shown in FIG. 3, the polarization direction and the shift position of the light at the time when the light passes through the second liquid crystal shutter 14 are turned on / off of the first liquid crystal shutter 11 and the second liquid crystal shutter 14. When the combination of OFF is OFF / OFF, there is a shift to the left diagonally downward with the first polarized light. When it is OFF / ON, there is a shift to the diagonally downward left with the second polarized light. Is shifted diagonally right downward with the second polarized light. If ON / ON, there is a shift diagonally right downward with the first polarized light.

After that, the light enters the third birefringent plate 15. The third birefringent plate 15 has a crystal axis direction extending from the lower left to the upper right, and shifts the optical path of the second polarized light in the incident light obliquely upward to the right as shown in FIG. The first polarized light is passed almost as it is.

As described above, the combination of ON / OFF of the first liquid crystal shutter 11 and the second liquid crystal shutter 14 is repeatedly performed in the order shown in FIG. Symbol A → B → C → D shown in FIG. 4 (B)
→ Each position corresponding to the four vertices of the parallelogram is cyclically moved as indicated by A, and the number of pixels is increased and observed due to the effect of the afterimage of the human eye. In FIG. 4B, P indicates the position of the original pixel.

When displaying a high-definition image using the wobbling unit 6 configured as described above, NT
When an SC video signal is input, as shown in FIG. 4A, the first liquid crystal shutter 11 is turned on / off so that the polarization is switched at 30 Hz, and the second liquid crystal shutter 14 is turned on. By turning ON / OFF such that the polarization is switched at 60 Hz, the pixel positions are switched to four points in the order of A, B, C, and D within 30 Hz per frame. And
By displaying the video signal sampled at positions corresponding to the four points on the LCD 4 in synchronization with the switching of the four points, the resolution can be effectively quadrupled.
The shift amount between the pixel positions A and B in FIG. 4B is the horizontal direction P _X / 2, and the shift amount between the pixel positions A and D is the vertical direction P _Y / 2 and the horizontal direction P _X / 4. The shift amount between A and C is the vertical direction P _Y /
2, horizontal direction P _X · 3/4.

At this time, the first and second liquid crystals determine which pixel positions of the wobbling pixel shift positions A, B, C, and D are shifted on the LCD and in which order. It can be controlled by a combination of ON / OFF of the voltage applied to the shutters 11, 14.

The configuration example of the wobbling unit shown in FIG. 3 has a configuration in which the pixel arrangement generated by the wobbling is shifted in a horizontal direction and an obliquely upward direction such that the pixel arrangement becomes substantially a delta arrangement. Can be similarly used in a wobbling unit configured to shift in the horizontal and vertical directions.

In order to shift the pixels in the horizontal direction and the vertical direction, for example, light from an LCD that emits light in an oblique polarization direction is horizontally polarized before the wobbling unit having the structure shown in FIG. What is necessary is just to comprise using the birefringent plate which shifts a polarization to a horizontal and a vertical direction while using the polarizing plate which converts into light.

Next, the operation when the video signal of the game machine is used as the input video signal will be described. As shown in FIG. 5, the video signal of the game machine is different from the format of the video signal of the NTSC system, and does not have a field signal for interlaced scanning in the video signal of the NTSC system, and is composed of only a frame signal. The number of lines in the horizontal direction is half that of the video signal of the NTSC system, and a frame signal is formed. Therefore, the vertical resolution is NTS
It is の of the video of the C system. The frame rate is 60 Hz in the illustrated example, and each frame period is 1/60 sec.

As described above, since the video signal of the game machine is composed of the frame signal of ラ イ ン line number without the field signal and the vertical resolution is １ ／,
Even if the wobbling method of four-point pixel shift is adopted, the resolution in the vertical direction cannot be improved. For this reason,
The wobbling method is applied to the video signal of the game machine by performing the following processing.

First, the signal processing section 2 performs image processing to generate an LCD input video signal for wobbling in a format as shown in FIG. That is, this LC
The D input video signal divides each frame signal F1, F2, F3,... Of the input video signal of the game machine into two in the horizontal direction, and divides the divided field signals F1a, F1b, F2a,
F2b,... The field period of each divided field signal is 1/120 sec, and is generated and processed by double-speed image processing.

As shown in FIG. 7, the a-field signal and the b-field signal generated by dividing into two are generated by thinning out every other horizontal pixel signal of the video signal of the game machine. That is, in FIG. 7, A indicates the sampling position in one frame of the game machine video signal extracted to generate the a-field signal, and B indicates the sampling position of the signal extracted to generate the b-field signal. Is shown. in this way,
The sampling position is shifted in the horizontal direction between the a-field signal and the b-field signal, and the shift amount is P _X /
Equivalent to 2.

As the actual electrical signal processing in the signal processing unit 2 when generating such divided field signals a and b, first, all the input video signals are sampled, A / D converted, and stored in a memory. When taking in and generating an a-field signal, only the signal corresponding to the position A is read from the memory to generate the a-field signal, and only the signal corresponding to the position B is read from the memory to generate the b-field signal. Like that.

Next, the operation of the wobbling unit 6 for the wobbling LCD input video signal of the game machine video signal thus converted and generated will be described. Since the wobbling LCD input video signal of the game machine is obtained by dividing the frame signal into two and converting it into an a-field signal and a b-field signal as described above, the wobbling unit 6 performs a pixel shift correspondingly. Will be driven. That is, the sampling positions A and b of the a-field signal and the b-field signal shown in FIG.
120 Hz alternately in the order of B,,, ...
, The pixel shift may be performed horizontally.

In order to shift the pixel position only in the horizontal direction in the wobbling unit 6 as described above, the first wobbling unit 6 having the same configuration as shown in FIG.
(A) of FIG. 9 with respect to the second liquid crystal shutters 11 and 14.
A voltage may be applied as shown in FIG. 9, which can cause a pixel shift as shown in pixel positions A and B in FIG. 9B. Note that in FIG. 9B, P is the original pixel position. FIG. 10 shows a horizontal pixel shift mode when the above-described voltage application is performed in the wobbling unit 6.

FIG. 11 shows divided field signals F1a, F1b, F2a, F2b,...
.. Are timing charts showing a manner in which pixel positions at the time of horizontal two-point pixel shift driving of the wobbling unit correspond to each other, and a field signals F1a, F2a,.
.. Are shifted from the pixel position A when the LCD is outputting from the LCD, and emitted from the pixel position B when the b-field signals F1b, F2b,. This indicates that the pixel shift is performed as follows.

By applying the above-described video signal conversion processing of the game machine and the corresponding two-point pixel shifting method of the wobbling unit, the horizontal resolution of the game machine video can be doubled. . As described above, since the number of lines in the vertical direction in the video of the game machine is の of that in the NTSC video, the resolution cannot be improved even if the pixel is shifted in the vertical direction. In terms of points, the four-point pixel shift mode is meaningless, and it is sufficient to use the horizontal two-point pixel shift method.

By applying the above-described two-point pixel shifting method in the horizontal direction of the wobbling unit, the resolution in the horizontal direction is doubled, but black lines (black matrix portions) which appear every other line in the LCD are displayed. It is preferable that there is no black line as an image display device because it is conspicuous. Therefore, it is not necessary to improve the resolution in the vertical direction, but in order to remove black lines on the screen,
A four-point pixel shifting method is adopted for the wobbling unit.

When the wobbling unit employs a four-point pixel shifting method, voltages to the first and second liquid crystal shutters are applied as shown in FIG. 12, and the pixel position is changed as shown in FIG. ,, In order of pixel position A,
The wobbling unit is driven at 240 Hz to shift to D, B, and C. In this case, as can be seen from FIG. 12, the drive control pulses to the first and second liquid crystal shutters have different phases but the same period.

In the case of the four-point pixel shift method in which the pixel position is shifted in the order of A, B, C, and D, which is applied to the NTSC video signal described above, the first and second liquid crystal shutters are used. Drive control signals have different periods, but the pixel positions are shifted in the order of A, D, B, and C in order to make the black matrix portion in the video of the game machine inconspicuous as described above. When the four-point pixel shift method is adopted, the cycle of the drive control signal to the liquid crystal shutter may be the same, and therefore, the configuration of the electric circuit of the pixel shift method selection switch unit 5 for generating this control signal is simplified. It can be. Further, the response characteristics of each liquid crystal shutter can be made uniform.

In the four-point pixel shifting method of the wobbling unit by driving as shown in FIGS.
In FIG. 13, the same information is displayed at (pixel positions A and D) and (pixel positions B and C). That is, the information of the a-field signal is displayed at the pixel positions A and D, and the information of the b-field signal is displayed at the pixel positions B and C, and the resolution is improved in the direction substantially perpendicular to or. Instead, an action like a low-pass filter is performed. That is, when the four-point pixel shift method is employed, the wobbling drive operation becomes more complicated than the two-point pixel horizontal shift method, but the number of horizontal lines (vertical resolution) of the video image of the game machine is lower than that of the NTSC video. Since it is half, the display pixels can be shifted even in a black line portion which is normally seen every other line in the horizontal direction, so that an image with good image quality without black lines can be provided.

FIG. 14 shows each of the divided field signals F1a, F1b,
FIG. 9 is a timing chart showing the correspondence between F2a, F2b,. With respect to the two divided a and b field signals every 1/120 sec, the a field signal is shifted to pixel positions A and D every 1/240 sec, and the b field signal is shifted to pixel positions B and C every 1/240 sec. The mode of shifting is shown.

As shown in FIG. 12, the wobbling unit shifts the four pixels by ON / OFF control such that the first and second liquid crystal shutters 11 and 14 each switch the polarization direction at 120 Hz. As shown in FIG. 15, the second liquid crystal shutter is 1/24 of the first liquid crystal shutter.
This is performed by controlling the drive with a delay of 0 sec. However, the ON / OFF cycle is the same.

The same effect can be obtained by shifting the pixel positions D, A, C, and B in the order of 240 Hz in the four-point pixel shift method. In this case, the phase of the second liquid crystal shutter is advanced by 1/240 sec with respect to the first liquid crystal shutter.
The pixel positions are in the order of D, A, B, C, or A, D, C,
The effect is the same in the order of B, but this shift method requires the liquid crystal shutter to be driven at 240 Hz.
Since the response of the liquid crystal shutter is required, the order of the pixel positions A, D, B, and C or the order of the pixel positions D, A, C, and B is preferable.

Next, a second embodiment will be described. FIG. 16 is a schematic block diagram showing the second embodiment, in which the same or corresponding components as those of the first embodiment shown in FIG. 1 are denoted by the same reference numerals. In this embodiment, a wobbling process is particularly performed on a three-dimensional (stereo, hereinafter abbreviated as 3D) video signal to provide a viewer with a 3D video with a stronger stereoscopic effect. is there. However, as in the case of the first embodiment, the present invention can of course also be used when obtaining a high-resolution video by wobbling processing of a two-dimensional NTSC video signal or a video signal of a game machine.

This embodiment is different from the first embodiment in that the left LCD 4-1 and the right L LCD are used as LCDs.
The CD4-2 is provided, and the wobbling unit for the left eye 6-1 and the wobbling unit for the right eye 6-2 are provided as the corresponding wobbling units. Is the first
This is the same as the embodiment. Therefore, by using one or both of the left-eye LCD and the right-eye LCD and the corresponding wobbling unit, as in the first embodiment, the NTSC video and the video of the game machine can be displayed. Can correspond.

In general, observation of a 3D image is to combine two-dimensionally displayed left-eye images and right-eye images, which are displayed separately, using stereoscopic image glasses and observe them as one stereoscopic image. FIG. 17 is a diagram showing a 3D video signal, in which a left-eye video signal F1L, F2L,...
R, F2R,..., And a left-eye video signal and a right-eye video signal continuously form one frame signal at front and rear positions in time, and the frame rate is an example. As 60Hz.

When the format of the 3D video signal having such a configuration is schematically shown as a 3D video screen such as an output video of a PC monitor in an easy-to-understand manner, as shown in FIG. Area is a 3D left-eye video signal, and the lower half area is a 3D right-eye video signal. The total number of lines for the upper and lower left and right eye video signals is 480 lines (1/1 /
60Hz).

In the present embodiment, the wobbling operation is performed on the input 3D video signal having such a configuration. Even in the wobbling operation on the 3D video signal, the pixel shift in the vertical direction is performed. Since the resolution cannot be increased even if the operation is performed, a two-point pixel shift method in the horizontal direction is applied. FIG. 19 shows sampling positions when the horizontal two-point pixel shifting method is applied. This is the same as the sampling position when the horizontal two-point pixel shift method is applied to the video signal of the game machine shown in FIG. 7, and the pixel position of the LCD of the same color (for example, only G) in monochrome or color is represented by A. , When the intermediate position of the horizontal pitch of the pixel position A of the LCD is B,
And B are the sampling positions in the wobbling operation of the 3D video signal.

In order to correspond to the wobbling sampling position set as described above, 3D transmitted to the LCD
The video signal needs to be converted for wobbling operation. Next, the LCD drive video signal converted for wobbling operation will be described with reference to FIG. First, for the first frame signals F1L and F1R of the 3D video signal, the signal processing circuit 2 generates signals F1L-A and F1R-A sampled only at the sampling position A, and outputs the first converted driving video signal. Frame signal. Next, 3
A signal F sampled only at the sampling position B with respect to the second frame signals F2L and F2R of the D video signal
2L-B and F2R-B are generated and used as the second frame signal of the conversion drive video signal. In the same manner, the conversion drive video signal is obtained by changing the sampling position in the order of A, B, A, B,... For each frame. This is a 3D LCD
The driver 3 outputs a driving video signal.

Next, the 3D LCD drive video signal is input to the left-eye and right-eye LCDs 4-1 and 4-2.
The CDs 4-1 and 4-2 are driven. As shown in FIG. 21A, in the left-eye LCD 4-1, in the first frame, in the first half, the left-eye driving video signal F1 is displayed.
The video of the left-eye LCD 4-1 is written by the LA, and the right-eye driving video signal F1R-A is transmitted from the driver in the latter half of the first frame. Holds the image of the driving image signal F1L-A input in the first half while inhibiting the rewriting of the image. Next, in the second frame, rewriting of the left-eye LCD 4-1 is performed by the driving video signal F2L-B in the first half, and rewriting is similarly inhibited in the second half, and the first half of the driving video signal F2L-B To hold the video. Hereinafter, the LCD 4-1 for the left eye is driven in the same manner.

On the other hand, the LCD 4-2 for the right eye
As shown in FIG. 21B, in the first half of the first frame, the right-eye driving video signal F1R-A delays the driving video signal for the left eye by 1/120 sec.
In the latter half, the left-eye drive video signal F2L-B is sent.
In the CD 4-2, the rewriting of the video is prohibited, and the video of the first half of the driving video signal F1R-A is held. In the second frame, the driving video signal F2R
The rewriting of the right-eye LCD 4-2 is performed by -B, and the rewriting is similarly inhibited in the second half, and the video of the first half driving video signal F2R-B is held. Hereinafter, the LCD 4-2 for the right eye is driven in the same manner.

In the present embodiment, the display timing of the left eye LCD 4-1 and the right eye LCD 4-2 is 1/12.
Although the time is shifted by 0 sec, the left-eye LCD 4-1 is written and rewritten and displayed earlier in time, but even if the right-eye LCD 4-2 is faster,
The same result is obtained.

Next, the left-eye and right-eye wobbling units 6-1 and 6 for the left-eye and right-eye LCD drive video signals in the 3D video signal thus converted and generated.
The operation of -2 will be described. Each of the LCD drive video signals for wobbling of the 3D video signal is converted and generated by switching the sampling position to A and B for each frame as shown in FIGS. ,
The driving of each of the wobbling units 6-1 and 6-2 is controlled so as to perform a pixel shift in response thereto. That is, each frame signal F of the left-eye LCD drive video signal
1LA, F2LB, F3LA,..., And each frame signal F1RA of the right-eye LCD driving video signal,
For the F2R-B, F3R-A,..., As shown in FIG.
,... May be alternately horizontally shifted at 60 Hz.

As described above, the wobbling units 6-1 and 6-1
To shift the pixel position only in the horizontal direction in 6-2, the first and second liquid crystal shutters 11-1, 11-2, 14-1, and 14-2 in each wobbling unit are respectively shown in FIG. A voltage similar to that shown in FIG.

23A and 23B show frame signals F1L-A, F2LB, F3L-A,... Of the left-eye and right-eye LCD drive video signals in the 3D video signal.
...., F1R-A, F2R-B, F3R-A, ...
Is a timing chart showing the relationship between pixel positions when wobbling horizontal two-point pixel shift is performed on an odd frame F1L- generated by sampling at a pixel position A;
A, F3L-A, ..., F1R-A, F3R-
A,... Are shifted by a pixel corresponding to the pixel position A, and the even frames F2LB, F4LB,.
Pixel position B for RB, F4R-B, ...
Is performed. In the case of a 3D video signal, the frame rate of the LCD drive video signal for the left eye and the LCD drive video signal for the right eye is 60 Hz, but is 1/120 sec.
Of each wobbling unit 6
It is necessary to send a separate liquid crystal shutter control signal to -1 and 6-2 to drive and control each of the wobbling units 6-1 and 6-2.

As described above, the conversion processing of the 3D video signal,
By applying the corresponding horizontal two-point pixel shifting method of each wobbling unit, the horizontal resolution of the 3D video signal can be doubled. As a result, the resolution of parallax can be increased, and an image from which a stronger stereoscopic effect can be obtained can be observed. As mentioned earlier,
In a 3D video signal, the number of lines in the vertical direction is one half that of the NTSC video in the left-eye video and the right-eye video, and therefore, even if the pixel is shifted in the vertical direction, the resolution cannot be improved. In terms of improving the resolution, the four-point pixel shift method is meaningless as in the case of the game machine video signal, and it is sufficient to use the horizontal two-point pixel shift method.

However, L used in 3D video
Even in CDs, the black lines visible every other line are conspicuous, so there is no need to improve the resolution in the vertical direction. Similarly, a four-point pixel shifting method may be adopted.

When the four-point pixel shifting method is employed in the wobbling unit of this embodiment, each wobbling unit 6-6 is used as in the case of the first embodiment.
A voltage is applied to the first and second liquid crystal shutters 1 and 6-2 as shown in FIG. 12, and the pixel positions are changed in the order of pixel positions A, D and B as shown in FIG. , C, each wobbling unit 6-1 at 120 Hz.
6-2 is driven.

In the four-point pixel shifting method of each of the wobbling units 6-1 and 6-2 by such driving,
In FIG. 24, the same information is displayed at (pixel positions A and D) and (pixel positions B and C). That is, the information of the odd-numbered frame signal is displayed at the pixel positions A and D, and the information of the even-numbered frame signal is displayed at the pixel positions B and C, and the resolution is not improved in this direction. Function is performed. In other words, when the four-point pixel shift method is employed, the wobbling drive operation becomes more complicated than in the two-point pixel shift method, but the display pixels are also shifted in the black line portion that appears every other line in the horizontal direction. Therefore, even in the case of a 3D image, a 3D image of good image quality without black lines can be observed.

FIGS. 25A and 25B show a case where a four-point pixel shift method by wobbling is applied to a 3D video image.
Left eye frame signals F1LA, F2LB, F3L-
A,... And right-eye frame signal F1R-A, F
FIG. 9 is a timing chart showing a correspondence relationship between 2R-B, F3R-A,... And shift pixel positions. The frame rates of the left eye frame signal and the right eye frame signal are
At 60 Hz, both frame signals have a time lag of 1/120 sec. In the case of an odd-numbered frame, the pixel positions A and D are displayed at 1/120 seconds, and in the case of an even-numbered frame, the pixel positions B and C are displayed at 1/120 seconds.

Note that the same effect can be obtained by shifting the pixel position in the order of D, A, C, and B at 120 Hz in the four-point pixel shift method in the 3D video signal.

[0073]

As described above with reference to the embodiment, according to the first aspect of the present invention, the same optical system composed of two sets of optical blocks is provided with a wobbling mode for shifting four pixels having different shift orders. So you can
It is possible to realize a video display device that achieves high resolution for different kinds of input video signals by a wobbling operation. According to the invention of claim 2, the optical block 2
Higher resolution can be achieved by the wobbling operation of the four-point pixel shift method and the two-point pixel shift method with the same optical system composed of sets. According to the third aspect of the invention,
In a video display device in which the wobbling operation of the four-point pixel shift method and the two-point pixel shift method can be performed with the same optical system, the electric circuit configuration of the optical block control means can be simplified, and the response characteristics of the modulation element Can be aligned between the two optical blocks. According to the fourth aspect of the present invention, in a video display device capable of observing an image having a high apparent resolution only in the horizontal direction, the black matrix can be made inconspicuous. According to the fifth aspect of the present invention, it is possible to increase the horizontal resolution of the left-eye and right-eye display elements in the 3D video, improve the parallax resolution, and obtain a stronger stereoscopic image. Can be observed. According to the invention of claim 6, it is possible to efficiently observe a high-definition stereo image without requiring separate control means for the left-eye video signal and the right-eye video signal. According to the seventh aspect of the present invention, a video signal for shifting pixels in the horizontal direction of a stereo video signal obtained by sampling at a different sampling timing for each frame can be obtained with high accuracy. Fine definition is possible.

[Brief description of the drawings]

FIG. 1 is a schematic block diagram showing a first embodiment of a video display device according to the present invention.

FIG. 2 is a diagram showing a pixel array mode of the LCD in the embodiment shown in FIG.

FIG. 3 is an exploded perspective view showing a configuration of a wobbling unit in the embodiment shown in FIG.

FIG. 4 is a diagram illustrating a mode of a voltage applied to a liquid crystal shutter and a pixel shift in a wobbling unit when performing four-point pixel shift.

FIG. 5 is a diagram showing a video signal of the game machine.

FIG. 6 is a diagram showing an LCD drive video signal of a game machine video signal electrically processed for wobbling.

FIG. 7 is a diagram showing sampling positions of game machine video signals for generating the LCD drive video signals shown in FIG. 6, represented by LCD pixel positions.

FIG. 8 is a diagram showing a pixel shift mode by a wobbling unit with respect to a game machine video signal.

FIG. 9 is a diagram illustrating an applied voltage to the wobbling unit and a mode of pixel shift when the horizontal two-point pixel shift illustrated in FIG. 8 is performed.

FIG. 10 is a diagram illustrating a horizontal two-point pixel shift mode in the wobbling unit.

FIG. 11 is a timing chart showing a relationship between pixel shift positions in a horizontal two-point pixel shift method with respect to a field signal obtained by electrically converting a game machine video signal.

FIG. 12 is a diagram showing an aspect of an applied voltage in a four-point pixel shifting method by a wobbling unit applied to a game machine video signal.

FIG. 13 is a diagram illustrating a pixel shift mode in a four-point pixel shift method applied to a game machine video signal.

FIG. 14 is a timing chart showing a relationship between pixel shift positions in a four-point pixel shift method with respect to a converted field signal of a game machine video signal.

FIG. 15 illustrates control signals for the first and second liquid crystal shutters in the wobbling unit when the four-point pixel shift illustrated in FIG. 13 is performed.

FIG. 16 is a schematic block diagram illustrating a second embodiment of the present invention.

FIG. 17 is a diagram illustrating a 3D video signal.

FIG. 18 is a diagram schematically illustrating a 3D video signal in an output image of a PC monitor.

FIG. 19 is a diagram illustrating a sampling position of a 3D video signal for generating an LCD drive video signal when the horizontal two-point pixel shift method is applied to the 3D video signal, by using an LCD pixel position.

FIG. 20 is a diagram illustrating an LCD drive video signal of a 3D video signal that is electrically processed for wobbling.

FIG. 21 is a timing chart illustrating a mode of writing and holding of left-eye and right-eye LCD drive video signals to the left-eye and right-eye LCDs.

[Fig. 22] Fig. 22 is a diagram illustrating a pixel shift mode by a wobbling unit for a 3D video signal.

FIG. 23 is a timing chart showing a relationship between pixel shift positions in a horizontal two-point pixel shift method for each frame signal of a left-eye and right-eye LCD drive video signal of a 3D video signal.

FIG. 24 is a diagram illustrating a pixel shift mode in a four-point pixel shift method applied to a 3D video signal.

FIG. 25 is a timing chart showing a relationship between pixel shift positions in a four-point pixel shift method for each frame signal of a left-eye and right-eye LCD drive video signal of a 3D video signal.

[Explanation of symbols]

 Reference Signs List 1 decoder 2 signal processing unit 3 LCD driver 4 LCD 4-1 left eye LCD 4-2 right eye LCD 5 pixel shifting method selection switch unit 6 wobbling unit 6-1 left eye wobbling unit 6-2 right eye wobbling Unit 11-1, 11-2 First liquid crystal shutter 12 First birefringent plate 13 Second birefringent plate 14, 14-1, 14-2 Second liquid crystal shutter 15 Third birefringent plate

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G09G 3/36 G09G 3/36 5C080 H04N 5/66 102 H04N 5/66 102B F-term (Reference) 2C001 BC10 CC01 2H088 EA08 HA15 HA18 MA20 5C006 AC25 BA00 BB08 BB11 EC12 5C058 AA06 AB00 BA25 BA35 BB04 BB05 BB11 BB25 5C061 AA03 AA11 AB12 AB14 5C080 AA10 BB05 DD07 EE29 FF10 JJ02 JJ04 JJ05 JJ06 JJ06

Claims (7)

[Claims] An image having a resolution apparently higher than the resolution of the display element is obtained by performing an optical shift on a light beam emitted from each pixel of the display element in accordance with an input video signal. A modulation element that switches the polarized light emitted from the display element to polarized light of two polarization planes orthogonal to each other and emits the polarized light, and 2 related to the polarized light emitted from the modulating element. Two sets of optical blocks each including at least one birefringent medium having a crystal axis substantially parallel to one of the polarization planes, and each modulation element of the optical block depending on the type of the input video signal Means for switching between a mode for switching at different frequencies and a mode for switching each modulation element of the optical block at the same frequency. A video display device, characterized in that 2. A video display device capable of performing pixel shift by optically shifting a light beam emitted from each pixel of a display element to observe an image having a resolution apparently higher than the resolution of the display element. And a modulation element that switches the polarized light emitted from the display element to two polarized planes orthogonal to each other and emits the polarized light, and one of the two polarized planes related to the polarized light emitted from the modulator. When two sets of optical blocks each including at least one birefringent medium having a crystal axis substantially parallel to the plane are set, the light rays emitted from each pixel of the display element are shifted to four positions by the pixels. Is selectively shifted by the two optical blocks or passed as it is, and a four-point pixel shift is performed by a combination of the selections. When shifting a light ray emitted from a pixel to two points, the light ray is allowed to pass through one of the two optical blocks as it is,
An image display device comprising: an optical block control means for selecting whether to perform an optical shift or to pass the light as it is in the other optical block, and to act so as to shift two pixels by a combination of the selection. . 3. The optical block control means controls each of the modulation elements in each of the optical blocks with two drive signals having the same period, and each of the optical blocks supplies the drive signal to each of the modulation elements. The light modulating element and the birefringent medium are arranged so that a light ray emitted from each pixel of the display element can be shifted by four or two points when the image is displayed. 3. The video display device according to claim 2, wherein: 4. A pixel is shifted to four points corresponding to the vertices of a rectangle by optically shifting light rays emitted from each pixel of the display element, and apparently in the horizontal direction rather than the resolution of the display element. A video display device capable of observing an image having only a high resolution, wherein information of pixels at two substantially adjacent positions in the four-point position after the pixel shift is the same. A video display device comprising information and a sequence of shifting pixels to two substantially vertically adjacent pixel positions in the four-point pixel shifting operation is continuous with each other. 5. A receiving means for receiving a stereo video signal transmitted in a video signal period of one frame in which a video signal for the left eye and a video signal for the right eye are successively transmitted in a temporally forward and backward position; Sampling means for sampling the video signal at different sampling timings for each frame, displaying a left-eye image on the left-eye display element of the stereo image signal sampled by the sampling means, and displaying a right-eye image on the right eye Display means for displaying with the display element for left and right, and the light emitted from the pixels of the display element for left eye and the display element for right eye are arranged respectively on the display element for left eye and the display element for right eye, and optically shift the light An optical unit for switching the polarized light into polarized light of two polarization planes orthogonal to each other and emitting the same. And an optical block set comprising at least one birefringent medium having a crystal axis substantially parallel to one of the two polarization planes of polarized light emitted from the modulation element, wherein at least the display An image display device characterized in that it is configured to shift pixels in the horizontal direction of the means. 6. The display means for a left-eye display element and a left-eye optical block for transmitting a left-eye video signal during a period in which a left-eye video signal is transmitted during the one frame period. It works so that the video signal can be observed,
The display element for the right eye and the optical block for the right eye act to hold the right-eye video signal of the previous frame transmitted immediately before so as to be observable. During the period in which the video signal is transmitted, the right-eye display element and the right-eye optical block act so that the transmitted right-eye video signal can be observed,
6. The image display device according to claim 5, wherein the left-eye display element and the left-eye optical block are configured to act so as to hold the left-eye image signal of this frame so as to be observable. 7. The apparatus according to claim 1, wherein the sampling means is configured to sample two adjacent frames on the time axis while shifting the phase of the sampling point by 周期 cycle. 5. The video display device according to 5.