JPH09325321A - Driving method for video display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the driving method for the video display device which has a ferroelectric liquid crystal display element which provides a high-definition and high-luminance video display. SOLUTION: A video memory write timing signal generator 14 outputs a video memory write control signal F synchronized with an input video signal A to a video memory 11 and outputs a video data complement timing signal H to a memory read timing signal generator 15. The memory read timing signal generator 15 outputs a video memory read control signal G synchronized with a horizontal scanning device horizontal synchronizing signal K outputted from a horizontal scanning device 17 making a horizontal scan at a natural frequency to the video memory 11. In this case, the memory read timing signal generator 15 complements the video signal by including the video data complement timing signal H in the video memory read control signal G.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a driving method of an image display device having a ferroelectric liquid crystal display element capable of displaying an image with high definition and high brightness.

[0002]

2. Description of the Related Art In recent years, there has been a demand for a high-definition and high-luminance video display for a video display device having a liquid crystal display element.

In a conventional image display device having a liquid crystal display element, as the liquid crystal display element, one in which a pixel electrode for image display and a peripheral scanning circuit are combined and mounted on the same semiconductor chip is mainly used. As a driving method of such an image display device, mainly,
A method of inputting a drive signal of appropriate timing from the outside of the liquid crystal display element to the peripheral scanning circuit is adopted.

[0004]

However, in the conventional driving method of the image display device, the liquid crystal display element is
Since the configuration is such that the pixel electrode for video display and the peripheral drive circuit are combined, there is a limit in the design of the liquid crystal display element to meet the demand for high definition and high brightness of the video display of the video display device. Has occurred. Hereinafter, the design limitation of the conventional liquid crystal display device will be described with reference to the drawings.

FIG. 5 shows the internal structure of a liquid crystal display element in the conventional image display device.
An image display unit 3 including a pixel electrode 1 and an analog switch 2, a horizontal scanning circuit 4, and a vertical scanning circuit 5.

As shown in FIG. 5, since the analog switch 2 is provided so as to be paired with the pixel electrode 1, the analog switch 2 causes a reduction in the aperture ratio of the pixel electrode 1 and in order to achieve high brightness. Is a problem with.

Further, as the pixel definition is increased, the aperture ratio of the pixel electrode 1 is further reduced. Therefore, there is a problem that the increase in brightness is suppressed when the pixel definition is increased.

As described above, in a liquid crystal display device having a liquid crystal display element in which a pixel electrode for video display and a peripheral drive circuit are combined, in terms of high definition and high brightness of video display. There are limits.

In view of the above, it is an object of the present invention to provide a driving method of an image display device having a ferroelectric liquid crystal display element capable of achieving high definition and high brightness of the image display device. .

[0010]

In order to achieve the above object, the present invention receives a write video signal, stores the input write video signal as video data, and stores the stored video data. To output as a read video signal, a laser generator that emits laser light based on the read video signal output from the video memory, and laser light emitted from the laser generator to a ferroelectric liquid crystal display element. In a method of driving a video display device including a movable mirror for irradiating, time axis conversion is performed between a write video signal input to a video memory and a read video signal output from the video memory to a laser generator. By doing so, it is possible to display an image on the ferroelectric liquid crystal display element by the write image signal, that is, the input image signal.

Specifically, the means for solving the problems according to the invention of claim 1 is to receive a write video signal at a first horizontal sync frequency and a first vertical sync frequency, and to use the input write video signal as video data. A video memory for storing and outputting the stored video data as a read video signal at a second horizontal synchronizing frequency and a second vertical synchronizing frequency, and a laser based on the read video signal output from the video memory. Driving method of video display device including laser generator for emitting light and movable mirror for horizontally scanning at natural frequency when irradiating the ferroelectric liquid crystal display device with laser light emitted from the laser generator And setting the second horizontal synchronizing frequency to a frequency that matches the natural frequency, and setting the second vertical synchronizing frequency to the read image. A frequency setting step of setting the period of the signal to be shorter than the period of the write video signal; and a shortage of video data in which the read video signal is insufficient with respect to the write video signal in frame units, field units or horizontal scanning units. And a video signal output step of complementing and outputting the read video signal.

According to the first aspect of the present invention, the second horizontal synchronizing frequency of the read video signal output from the video memory is matched with the natural frequency of the movable mirror and the second horizontal sync frequency of the read video memory output from the video memory. Since the cycle of the vertical synchronizing frequency of is set shorter than the cycle of the first vertical synchronizing frequency of the write video signal input to the video memory, the read video data is insufficient for the write video data. Data in frame units,
Since the read video signal is complemented and output in the field unit or the horizontal scanning unit, the time axis conversion from the write video signal to the read video signal is realized.

According to a second aspect of the present invention, in the configuration of the first aspect, a first system memory, a second system memory and a second system which sequentially store the input write video signal in the video memory as the video data. The method further comprises the step of providing three systems of memory in parallel, and the video signal output step includes the step of outputting the video data among the video data stored in the first system memory, the second system memory and the third system memory. Is configured to include a step of complementing a part of the above as the insufficient video data to the read video signal.

Specifically, the means for solving the problems according to the third aspect of the invention is to receive a writing video signal at the first horizontal synchronizing frequency and the first vertical synchronizing frequency, and to use the inputted writing video signal as video data. A video memory for storing and outputting the stored video data as a read video signal at a second horizontal synchronizing frequency and a second vertical synchronizing frequency, and a laser based on the read video signal output from the video memory. Driving method of video display device including laser generator for emitting light and movable mirror for horizontally scanning at natural frequency when irradiating the ferroelectric liquid crystal display device with laser light emitted from the laser generator And setting the second horizontal synchronizing frequency to a frequency that matches the natural frequency, and setting the second vertical synchronizing frequency to the read image. A frequency setting step of setting the period of the signal to be longer than the period of the write video signal, and excess video data that is left over from the read video signal by the write video signal in frame units, field units or horizontal scanning units. And a video signal output step of thinning out the written video signal and outputting the thinned video signal.

According to the third aspect of the present invention, the second horizontal synchronizing frequency of the read video signal output from the video memory is matched with the natural frequency of the movable mirror and the second horizontal sync frequency of the read video memory output from the video memory. Since the cycle of the vertical synchronizing frequency of is set to be longer than the cycle of the first vertical synchronizing frequency of the write video signal input to the video memory, the write video data is redundant with respect to the read video data. Since the writing video signal is thinned out and output in frame units, field units, or horizontal scanning units, time-axis conversion from the writing video signal to the reading video signal is realized.

According to a fourth aspect of the present invention, in the configuration of the third aspect, the first system memory, the second system memory, and the second system memory which sequentially store the input write video signal in the video memory as the video data. The method further comprises the step of providing three systems of memory in parallel, and the video signal output step includes the step of outputting the video data among the video data stored in the first system memory, the second system memory and the third system memory. A configuration including a step of thinning out a part of the above as the surplus image data is added.

According to a fifth aspect of the present invention, in the structure according to the first to fourth aspects, the movable mirror is reciprocated in one direction and another direction opposite to the one direction, and the movable mirror moves in the one direction. And a configuration further including the step of making the period during which the movable mirror performs one horizontal scanning coincide with the period during which the movable mirror operates in the other direction.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION First, an image display device which is a target of a method for driving an image display device according to each embodiment of the present invention will be described with reference to FIG.

FIG. 1 shows the overall structure of the video display device. The video display device includes an analog-digital converter 10, a video memory 11, a digital-analog converter 12, a laser generator 13, and an analog-digital converter 10. The video memory write timing signal generator 14, the video memory read timing signal generator 15, a vertical scanning device 16, a horizontal scanning device 17, a scanning mirror 18, and a ferroelectric liquid crystal display element 19 are provided for vertical scanning. Device 16, horizontal scanning device 17
The scanning mirror 18 and the scanning mirror 18 constitute a movable mirror scanning device 20.

The above-mentioned video display device emits the modulated laser light L ₁ modulated based on the input video signal A input to the analog-digital converter 10 from the laser generator 13, and the emitted modulated laser light L ₁ Is reflected by the scanning mirror 18 of the movable mirror scanning device 20, and the scanning laser light L ₂
By irradiating the ferroelectric liquid crystal display element 19 as described above, a high-definition and high-luminance image display, which is a feature of the ferroelectric liquid crystal display element 19, is realized. The horizontal scanning device 17 operates the scanning mirror 18 by utilizing the resonance motion to perform horizontal scanning, but performs horizontal scanning at a natural frequency which is different from the horizontal synchronizing frequency of the input video signal A and is a nearby frequency.

(First Embodiment) Hereinafter, a driving method of an image display device according to a first embodiment of the present invention will be described with reference to the drawings.

The feature of the first embodiment is that the input video signal A is
Is converted into a time axis to output a laser light modulation video signal I synchronized with the natural frequency of the horizontal scanning device 17, and a modulated laser light L ₁ is emitted from the laser generator 13 based on the laser light modulation video signal I. It is a thing.

The process of converting the input video signal A on the time axis and outputting the laser light modulation video signal I will be described below.

When the input synchronizing signal D synchronized with the input video signal A is input, the video memory write timing signal generator 14 sends the analog-digital converter control signal E to the analog-digital converter 10 and the video memory write control signal. F is output to the video memory 11 and the video data complement timing signal H is output to the video memory read timing signal generator 15. Further, the horizontal scanning device 17 outputs a horizontal scanning device horizontal synchronization signal K synchronized with the natural frequency to the memory read timing signal generator 15.

Memory read timing signal generator 1
When the horizontal scanning device horizontal synchronization signal K is input from the horizontal scanning device 17, the reference numeral 5 outputs a video memory read control signal G synchronized with the horizontal scanning device horizontal synchronization signal K to the video memory 11 and also the vertical scanning device. A vertical scanning device control signal J for driving the vertical scanning device 16
Output. In this case, the memory read timing signal generator 15 includes the video data complement timing signal H input from the video memory write timing signal generator 14 in the video memory read control signal G to complement the video data described later. To do.

Further, the analog-digital converter 10 is
When the input video signal A is input, the video memory write digital video signal B is output to the video memory 11 at the timing synchronized with the input video signal A, and the output video memory write digital video signal B is output to the video memory 11. Written. The video memory 11 is a video memory read control signal G synchronized with the horizontal scanning device horizontal sync signal K.
Is input, the video memory read digital video signal C is output to the digital-analog converter 12, and the digital-analog converter 12 converts the input video memory read digital video signal C into an analog signal for laser light modulation. It is converted to I and output to the laser generator 13.

The process of complementing the video data performed by the memory read timing signal generator 15 will be described below with reference to FIG.

The input video signal A is an interline system video signal, S indicates an odd field period of the input video signal A, and T indicates an even field period of the input video signal A. Vertical sync signal M and frame sync signal N
Is a signal synchronized with the input video signal A and controls the timing of writing the video memory write digital video signal B to the video memory 11. The vertical synchronizing signal Q and the frame synchronizing signal R are synchronized with the scanning frequency (the above-mentioned natural frequency) of the vertical scanning device 16, and the video memory 1
The read timing of the video memory read digital video signal C from 1 is controlled. In FIG. 2, “write” means that the video memory 11 is in the writing operation, and “read” means that the video memory 11 is in the reading operation, and D1A and D1 surrounded by rectangular frames are shown.
1B, D2A ... Are symbols for dividing video data in field units.

As shown in FIG. 2, in the first embodiment, the cycle of the frame sync signal N synchronized with the input video signal A is longer than the cycle of the frame sync signal R synchronized with the scanning frequency of the vertical scanning device 16. The ratio of the scanning frequency of the horizontal scanning device 17 to the scanning frequency of the vertical scanning device 16 is set so as to be longer. Therefore, for the video memory write digital video signal B synchronized with the input video signal A, the video memory read digital video signal C for scanning display output from the video memory 11 has a shortage of video data. Become.

Therefore, in the first embodiment, in order to correct the shortage of the video data of the video memory read digital video signal C and obtain the video memory read digital video signal C which is continuous in terms of content and time, The shortage of the video data of the memory read digital video signal C is steadily supplemented in frame units. That is, the timing at which the video frame of the frame synchronization signal R is completely included in the video frame of the frame synchronization signal N is detected, and one frame of video data is also detected at the timing at the next one frame of the frame synchronization signal R. Video data is complemented by repeatedly outputting it as complementary video data U. In this case, the video memory read timing signal generator 14 outputs the video complement timing signal H including the complement timing information to the video memory read timing signal generator 15, so that the video memory read timing signal generator 15 complements. The video memory read control signal G including the timing is output to the video memory 11.

Further, in the first embodiment, the video memory 11 is a parallel video memory of three systems in order to surely perform the time base conversion so that the video memory read digital video signal C having continuous contents is obtained. Have That is, in FIG. 2, as shown by the operation timing and operation content P of the three systems of parallel video memories, the video memory 11
Has three systems of parallel video memories for writing and reading frame-by-frame video data in a time-sharing manner. Further, since the three systems of parallel video memory complement video data in units of frames, the same video data as the video data one frame before is synchronized with the video data complement timing in synchronization with the frame synchronization signal R. The video data read out from 11 is used as complementary video data U.

A horizontal scanning process of performing horizontal scanning by utilizing the reciprocating motion of the horizontal scanning device 17 in order to effectively use the operating frequency of the horizontal scanning device 17 will be described below with reference to FIG.

As shown in FIG. 3A, the scanning mirror 18
The horizontal scanning device 17 is arranged so that the axis direction of the scanning mirror 1 is parallel to the display screen of the ferroelectric liquid crystal display element 19, and the scanning mirror 1
8 is resonated at a deflection angle W from −φ to + φ, and the emission angle of the scanning laser light L ₂ is changed according to the resonance operation. Further, in the first embodiment, as shown in FIG. 3B, the operation period in one direction of the resonance operation is made to coincide with the horizontal image scanning period Y which is the period of the horizontal synchronizing signal X for image scanning. ing. That is, the scanning mirror 15 in one direction
By scanning one horizontal scanning line during the operation period of 1 and the scanning of one horizontal scanning line during the operation period in the other direction opposite to the one direction, the scanning mirror 18 is reciprocated during one reciprocating operation period. The horizontal scanning line is being scanned.

By this horizontal scanning step, as can be seen from FIG. 3B, the scanning direction in the horizontal direction of the screen is reversed every horizontal period Y of the video scanning, so that the digital video signal C for reading the video memory is scanned. It is necessary to read from the video memory 11 at a timing matching with. Therefore, the first
In the embodiment, the video data is read from the video data Z _L on the left side of the screen to the video data Z _R on the right side of the screen in accordance with the horizontal scanning from the left side to the right side of the display screen in the embodiment. In accordance with the horizontal scanning from the right side to the left side of the display screen, the video data Z _R on the right side of the screen is read out to the video data Z _L on the right side of the screen.
In this way, horizontal scanning is realized by utilizing the reciprocating motion of the horizontal scanning device 17.

(Second Embodiment) A method of driving an image display device according to a second embodiment of the present invention will be described below with reference to the drawings.

Also in the second embodiment, the input video signal A is time-axis converted to produce the laser light modulation video signal I synchronized with the natural frequency of the horizontal scanning device 17, and the laser light modulation video signal I is used. The modulated laser light L ₁ is emitted from the laser generator 13.

The process of converting the input video signal A on the time axis and outputting the laser light modulation video signal I will be described below.

Similar to the first embodiment, when the input synchronizing signal D synchronized with the input video signal A is input, the video memory write timing signal generator 14 converts the analog-digital converter control signal E into an analog-digital converter. 10, the video memory write control signal F is output to the video memory 11, and the video data thinning timing signal H is output to the video read timing signal generator 15. Further, the horizontal scanning device 17 outputs a horizontal scanning device horizontal synchronizing signal K synchronized with the natural frequency to the memory reading timing signal generator 15.

Memory read timing signal generator 1
When the horizontal scanning device horizontal synchronization signal K is input from the horizontal scanning device 17, the reference numeral 5 outputs the video memory read control signal G synchronized with the horizontal scanning device horizontal synchronization signal K to the video memory and the vertical scanning device 16 And outputs a vertical scanning device control signal J for driving the vertical scanning device 16 to the vertical scanning device 16. In this case, the memory read timing signal generator 15 outputs the video data thinning timing signal H output from the video memory write timing signal generator 14.
Is input, and the video data thinning-out timing signal H is included in the video memory read control signal G to thin out video data described later.

Further, the analog-digital converter 10 is
When the input video signal A is input, the video memory write digital video signal B is output to the video memory 11 at a timing synchronized with the input video signal A, and the output video memory write digital video signal B is written to the video memory 11. Be done. When the video memory read control signal G synchronized with the horizontal scanning device horizontal synchronization signal K is input to the video memory 11, the video memory read digital video signal C is output to the digital-analog converter 12, and the digital-analog converter 12 is input. The digital video signal C read out from the video memory is converted into a video signal I for laser light modulation, which is an analog signal, and is output to the laser generator 13.

The process of thinning out the video data performed by the memory read timing signal generator 15 will be described below with reference to FIG.

Similar to the first embodiment, the input video signal A is an interline system video signal, S is an odd field period of the input video signal A, and T is the input video signal A.
Shows the even field period of. The vertical synchronizing signal M and the frame synchronizing signal N are signals synchronized with the input video signal A, and are digital video signals written in the video memory B.
Controls the timing of writing to the video memory 11. The vertical synchronizing signal Q and the frame synchronizing signal R are synchronized with the scanning frequency (the above-mentioned natural frequency) of the vertical scanning device 16, and control the read timing of the video memory reading digital video signal C from the video memory 11. Incidentally, in FIG. 4, the light means the video memory 11
Indicates that a write operation is being performed, read means that the video memory 11 is performing a read operation, and D1A, D1B, D2A ... Enclosed by a rectangular frame are symbols for dividing video data in field units. Is.

As shown in FIG. 4, in the second embodiment, the cycle of the frame sync signal N synchronized with the input video signal A is longer than the cycle of the frame sync signal R synchronized with the scanning frequency of the vertical scanning device 16. The ratio of the scanning frequency of the horizontal scanning device 17 to the scanning frequency of the vertical scanning device 16 is set so as to be short. Therefore, in the video memory write digital video signal B synchronized with the input video signal A, a surplus of video data is generated with respect to the video memory read digital video signal C for scanning display output from the video memory 11. Become.

Therefore, in the second embodiment, in order to correct the surplus of the image data with respect to the image memory read digital image signal C, the image memory write digital image signal output at the timing synchronized with the input image signal A. The image data of B is constantly thinned out in frame units. That is, the timing at which the video frame of the frame synchronization signal N is completely included in the video frame of the frame synchronization signal R is detected, and the video data for one frame is thinned out and output at the timing. Specifically, at the timing when the video frame of the frame synchronization signal N is completely included in the video frame of the frame synchronization signal R, the video memory 1
The thinned-out video data V written in 1 is overwritten by the video data of the next frame of the frame synchronization signal N without being read out, so that the thinned-out video data V is thinned out. In this case, the video memory write timing signal generator 14 outputs the video thinning timing signal H including the thinning timing information to the video memory read timing signal generator 15 so that the video memory read timing signal generator 1
Reference numeral 5 outputs the video memory read control signal G including the thinning timing to the video memory 11.

Further, in the second embodiment, in order to perform the time axis conversion including the thinning-out operation of the video data described above, as in the first embodiment, the parallel video memories of three systems as shown in FIG. 4 are used. have. That is, as shown in FIG. 4 by the operation timings and operation contents P of the parallel video memories of the three systems, the video memory 11 performs three systems in order to write and read the video data in frame units in a timely manner. It has a parallel video memory.

In the first and second embodiments, three lines of parallel video memory are used as the video memory 11, but four or more lines of parallel video memory may be used instead. Good.

In the first and second embodiments, the method of obtaining the laser light modulating video signal I by performing the time-axis conversion of the video data of the input video signal A on a frame-by-frame basis has been described. Alternatively, the video signal I for laser light modulation may be obtained by time-axis conversion of the video data of the input video signal A in field units or in units of one horizontal scanning line.

In the first and second embodiments, the interline system video signal is used as the input video signal A, but the non-interline system input video signal A is used.
The driving method according to the present invention can also be applied to the above.

[0049]

According to the driving method of the video display device of the first aspect of the present invention, the lacking video data, which is insufficient for the read video signal with respect to the write video signal, is read out by the frame unit, the field unit or the horizontal scanning unit. Since it is complemented with the output and the time axis conversion from the write video signal to the read video signal is realized, it is possible to display the video on the ferroelectric liquid crystal display element based on the write video signal, that is, the input video signal. Become. As a result, a driving method of a video display device for displaying a video with high definition and high brightness, which is a feature of the ferroelectric liquid crystal display element, is realized.

According to the driving method of the image display device of the second aspect, the first system memory, the second system memory and the third system which sequentially store the input write video signal as video data in the video memory. In order to complement the read video signal, a part of the video data stored in the memory of the first system, the memory of the second system and the memory of the third system is provided as insufficient video data as read-out video signals.
It is possible to reliably realize that the read video signal is complemented by the read video signal in frame units, field units, or horizontal scanning units.

According to the driving method of the video display device of the third aspect of the invention, the surplus video data generated in the write video signal with respect to the read video signal is displayed in frame units.
Since the write video signal is thinned out and output in units of fields or horizontal scans, the time axis conversion from the write video signal to the read video signal is realized. Therefore, the ferroelectric liquid crystal display device is based on the write video signal, that is, the input video signal. It becomes possible to display images on. As a result, a driving method of a video display device for displaying a video with high definition and high brightness, which is a feature of the ferroelectric liquid crystal display element, is realized.

According to the driving method of the image display device of the fourth aspect, the first system memory, the second system memory and the second system which sequentially store the input write video signal as video data in the video memory. Since three systems of memories are provided in parallel and a part of the video data stored in the first system memory, the second system memory, and the third system memory is thinned out as the surplus video data, a write video signal. In the above, it is possible to surely thin out the surplus video data generated with respect to the read video signal from the write video signal in frame units, field units or horizontal scanning units.

According to the driving method of the image display device of the fifth aspect of the invention, the movable mirror is reciprocated in one direction and the other direction, and the movable mirror operates in one direction and the other direction, respectively. And the period during which the movable mirror performs one horizontal scanning match, it is possible to perform horizontal scanning twice during one reciprocating period of the movable mirror, and efficiently use the operating frequency of the movable mirror. Horizontal scanning can be performed.

[Brief description of drawings]

FIG. 1 is a diagram showing an overall configuration of a video display device used in a method of driving a video display device according to each embodiment of the present invention.

FIG. 2 is a diagram illustrating a process of complementing video data in the driving method of the video display device according to the first embodiment of the present invention.

3A and 3B are diagrams for explaining the operation of the scanning mirror in the driving method of the image display device according to the first and second embodiments of the present invention.

FIG. 4 is a diagram illustrating a thinning process of video data in a driving method of a video display device according to a second embodiment of the present invention.

FIG. 5 is a plan view of a liquid crystal display element in a conventional image display device.

[Explanation of symbols]

10 analog-digital converter 11 video memory 12 digital-analog converter 13 laser generator 14 video memory write timing signal generator 15 video memory read timing signal generator 16 vertical scanning device 17 horizontal scanning device 18 scanning mirror 19 ferroelectric liquid crystal display Element 20 Scanning mirror scanning device A Input video signal B Video memory writing digital video signal C Video memory reading digital video signal D Input synchronizing signal synchronized with input video signal A E Analog-digital converter control signal F Video memory writing control signal G video Memory read control signal H Video complementary timing signal in the first embodiment and video thinning timing signal in the second embodiment I Video signal for laser light modulation J Vertical scanning device Control signal K horizontal scanning device horizontal synchronizing signals L ₁ parallel memory of the modulated laser beam L ₂ scanned frame synchronization signals P 3 lines in synchronization with the modulated laser beam M vertical synchronizing signal synchronized with the input video signal A N input video signal A Operation timing and content of Q Vertical sync signal for video scanning R Frame sync signal for video scanning S Odd field period of input video signal A T Even field period of input video signal A U Complementary video data V Thinned video data W Horizontal scanning Deflection angle of the mirror X Horizontal sync signal for video scanning Y Horizontal video scanning cycle Z _L Video data on the left edge of the display screen Z _R Video data on the right edge of the display screen

Claims (5)

[Claims] 1. A writing video signal is input at a first horizontal synchronizing frequency and a first vertical synchronizing frequency, the input writing video signal is stored as video data, and the stored video data is stored as a first video data. 2 horizontal sync frequencies and 2
A video memory that outputs a read video signal at the vertical synchronization frequency of, and a laser generator that emits laser light based on the read video signal output from the video memory,
A method of driving an image display device, comprising: a movable mirror that horizontally scans at a natural frequency when irradiating a ferroelectric liquid crystal display element with laser light emitted from the laser generator, wherein the second horizontal A frequency setting step of setting a synchronization frequency to a frequency that matches the natural frequency, and setting the second vertical synchronization frequency such that the cycle of the read video signal is shorter than the cycle of the write video signal; And a video signal output step of outputting the video data, which is insufficient for the read video signal with respect to the write video signal, by complementing the read video signal in frame units, field units, or horizontal scanning units. Driving method for video display device. 2. A first memory for sequentially storing the input write video signal as the video data in the video memory.
A system memory, a second system memory, and a third system memory are provided in parallel, and the video signal output step includes the first system memory, the second system memory, and the second system memory.
The video according to claim 1, further comprising a step of complementing a part of the video data stored in the system memory and the third system memory as the lacking video data with the read video signal. Driving method of display device. 3. A writing video signal is input at a first horizontal synchronizing frequency and a first vertical synchronizing frequency, the input writing video signal is stored as video data, and the stored video data is stored as a first video data. 2 horizontal sync frequencies and 2
A video memory that outputs a read video signal at the vertical synchronization frequency of, and a laser generator that emits laser light based on the read video signal output from the video memory,
A method of driving an image display device, comprising: a movable mirror that horizontally scans at a natural frequency when irradiating a ferroelectric liquid crystal display element with laser light emitted from the laser generator, wherein the second horizontal A frequency setting step of setting a synchronizing frequency to a frequency that matches the natural frequency, and setting the second vertical synchronizing frequency such that a cycle of the read video signal is longer than a cycle of the write video signal; A video signal output step of thinning out excess video data from a write video signal with respect to the read video signal in a frame unit, a field unit or a horizontal scanning unit and outputting the video signal. Driving method of display device. 4. A first memory for sequentially storing the input write video signal as the video data in the video memory.
A system memory, a second system memory, and a third system memory are provided in parallel, and the video signal output step includes the first system memory, the second system memory, and the second system memory.
The method for driving an image display device according to claim 3, further comprising a step of thinning out a part of the image data stored in the system memory and the third system memory as the surplus image data. 5. The movable mirror is reciprocated in one direction and in another direction opposite to the one direction, and each of the period during which the movable mirror operates in the one direction and the period during which the movable mirror operates in the other direction and the movable mirror. 5. The method for driving a video display device according to claim 1, further comprising the step of matching the period during which one horizontal scanning is performed.