JPH08137439A - Liquid crystal display device and liquid crystal display method - Google Patents

Abstract

PURPOSE: To provide a liquid crystal display device ameliorated in the degradation in vertical resolution of a two-line driving system of a liquid crystal projector, the addition of a hardware of a double speed driving system and the degradation in the luminance of a single plate system and a liquid crystal display method. CONSTITUTION: This liquid crystal display device is composed of a light source 10, a first half mirror 11, a first liquid crystal panel 13 to be made incident with the transmitted light thereof, a second liquid crystal panel 14, mirrors 12, 15, a second half mirror 16 and a projecting lens 17. The optical system thereof is arrayed in such a manner that the pixel groups of the panels attain the pixel arrangement shifted by a half pixel in a longitudinal direction. Since synthesized images are formed by using two sheets of the liquid crystal panels of the prior technique of 240 pieces in the vertical resolution, the liquid crystal projector of the high resolution of about 350 to 400TV pieces in the vertical resolution is realized without worry about the generation of flicker.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device and a liquid crystal display method which are effectively applied to various liquid crystal display devices such as a liquid crystal projector, and more specifically, a liquid crystal display device having improved resolution and brightness. The present invention relates to a display device and a liquid crystal display method.

[0002]

2. Description of the Related Art In recent years, along with the widespread use of devices with a liquid crystal display device represented by a VTR with a built-in camera and a liquid crystal projector, there is an increasing demand for higher performance of the liquid crystal display device. Among them, liquid crystal projectors are rapidly becoming popular because they can easily realize a large screen, and there is an increasing demand for higher resolution and higher brightness of the liquid crystal projectors, and the efforts are being made. The liquid crystal display device and the liquid crystal display method of the present invention are suitable for application to liquid crystal display devices in general,
Here, a transmissive liquid crystal projector will be described as an example of the liquid crystal display device.

A conventional liquid crystal display device and liquid crystal display method will be described with reference to FIGS.

First, the structure and operation of a conventional liquid crystal display device will be described with reference to FIG. In the figure, reference numeral 1
Indicates a conventional liquid crystal display device. The liquid crystal display device 1 of the prior art is generally composed of an external signal generator 2 and a liquid crystal panel 3. Although not shown, the external signal generator 2 receives a video signal and is a BL suitable for driving the liquid crystal panel 3.
The signals are converted into separate AC, UE, RED, and GREEN signals and output. At the same time, a necessary timing signal is generated and output to the liquid crystal panel 3. To explain the main ones of the timing signals, HST is a start pulse of a horizontal scanning circuit, which will be described later, and HCK is a timing pulse also used for controlling the horizontal scanning circuit.
VST is a start pulse of the vertical scanning circuit,
VCK is a timing pulse also used for controlling the vertical scanning circuit.

The liquid crystal panel 3 is constructed by integrally mounting, for example, a vertical scanning circuit 4 for controlling the scanning direction and a horizontal scanning circuit. The horizontal scanning circuit 4 includes a switch circuit that supplies R, G, and B video signals to each pixel. Further, each pixel is arranged in a matrix in the vertical scanning circuit 4 and the horizontal scanning circuit 5. The pixel arrangement example schematically shown in the figure is a Δdelta arrangement example in which the pixel pitch in the horizontal direction is shifted by half for each scanning line. Besides this, although not shown, it is mainly used for information equipment. Stripe arrangement,
There are methods such as diagonal stripe arrangement. Also, V
com is a common electrode of each pixel, and the broken line connected to the vertical scanning circuit 4 is a scanning line (line).

The vertical scanning circuit 4 and the horizontal scanning circuit 5 receive the R, G, B video signals and timing signals input from the external signal generator 2. The vertical scanning circuit 4
In the horizontal scanning circuit 5, the start pulse VST or H
The operation is started with ST as a start reference, and a video signal is taken in response to a timing pulse VCK or HCK and is supplied to each pixel through a signal line. In this way, the liquid crystal molecules (not shown) are twisted in the direction of the applied voltage so as to be inverted by the signal level supplied according to the video signal of each pixel, and an image is displayed on the liquid crystal panel 3 by utilizing the optical rotatory power of the liquid crystal molecules. Done.

The operation of the conventional liquid crystal display device and liquid crystal display method will be described with reference to FIG.

Generally, the driving method of the liquid crystal panel is AC driving in principle, and it is basically required not to apply a DC (direct current) voltage component. The reason for this is that the application of a DC voltage deteriorates the specific resistance of the liquid crystal molecules, which causes operational inconvenience. Due to the necessity of this AC drive, the conventional liquid crystal panel is generally a half-line drive in which the number of scanning lines is 240, which is half the number of effective scanning lines.

FIG. 8 shows a so-called 1H inversion driving method in which a video signal is inverted and applied for each line and the inversion direction is inverted for each field as an example of a conventional liquid crystal panel driving method. . In the figure, the + direction video signal is applied to the n lines of the m field, and the − direction video signal is applied to the n + 1 line. Similarly, n
The + direction video signal is applied at +2, and the-direction video signal is applied at n + 3 to drive the liquid crystal panel.

Next, in the (m + 1) th field, a video signal having a phase opposite to that of the above-mentioned m field is applied. That is, m +
The image signal in the-direction is applied to the n lines of one field, and the image signal in the + direction is applied to the n + 1 lines. A video signal is applied in the same manner thereafter. In the liquid crystal panel requiring the AC drive, the AC drive is performed by inverting the polarity of the video signal during the period of scanning all the lines in the vertical direction of the liquid crystal panel as described above. Therefore, the change in the visual brightness is 60 Hz, and no flicker is felt. Such an AC driving method shows that the driving frequency of the liquid crystal becomes 1/2 of the whole line scanning frequency. That is, when a liquid crystal panel is used for television display, when the number of scanning lines of the liquid crystal panel is less than the number of effective scanning lines for one field of the television video signal (about 240), the odd field signal of the television video signal is used. That is, the even field signals are overlapped (overwritten on the same line) to drive the liquid crystal panel.

Next, a timing chart of a conventional liquid crystal display device will be described with reference to FIG. In FIG. 9, after the application of the vertical synchronizing signal VD pulse generated for each field, the operation is started with the start pulse VST as the start reference. Vertical timing pulse VCK1
And VCK2 having a phase opposite to that of VCK1 sequentially outputs one selection pulse for each horizontal scanning period (1H). It indicates that the VCK1 is from 1 to the vertical display period, and then 2, 3, 4, ... Are sequentially scanned in the direction from the top to the bottom to form one screen. The polarity inversion signal shown in the figure is used for the purpose of polarity inversion of the video signal for each horizontal scanning period. It can be seen that the polarity inversion signal has the polarity inverted every VST as shown in FIGS.

[0012]

However, in the liquid crystal display device and the liquid crystal display method of the prior art, the number of effective scanning lines in the vertical direction is overwritten on 240 lines as described above, so that one frame worth of data is overwritten. It is not possible to completely reproduce the TV image. This display system was satisfied with a relatively small liquid crystal panel with a diagonal dimension of about 4 inches and a viewfinder of a VTR with a built-in camera, but a large liquid crystal panel and a liquid crystal for displaying an image enlarged several tens of times. Higher definition is required for projectors and the like. That is,
There has been a demand for the number of scanning lines of the liquid crystal panel to be about 480, which is the number of effective scanning lines that enables display of one frame of a television video signal. However, in order to suppress the occurrence of flicker and realize full line display, a special driving method is required, and some driving methods therefor have been proposed.

One of them is a driving method in which two scanning lines are simultaneously selected, the same video signal is applied, and the combination is changed for each field. However, this driving method is
Since the scanning lines of the book are driven at the same time, the vertical resolution is lowered, and the full line display of the current television broadcasting system cannot be completely reproduced. Further, since the two-line simultaneous driving method writes the video signals to two lines at the same time, it is limited to the liquid crystal panel of the stripe arrangement in which the signal lines are at the same position. Moreover, since the horizontal resolution of the stripe array is reduced to about 1/2 of that of the delta array, in order to realize the same horizontal resolution with the same number of pixels in the horizontal direction, the number of pixels in the horizontal direction is doubled. It becomes necessary and the liquid crystal panel cannot be downsized.

On the other hand, there is a double-speed driving system in which a frame memory circuit or other means generates a double-speed video signal and operates a time axis to convert the frame frequency into a frequency range where flicker does not occur. However, this driving method requires significant addition of hardware.
With such a typical driving method, a vertical resolution of 350
Although there is a liquid crystal panel that realizes about 400 TV lines, both types still have the above-mentioned basic problems.

A single-panel type liquid crystal projector using one liquid crystal panel capable of full line driving has also appeared, but in order to improve the resolution in this single-panel type liquid crystal projector, the pixel arrangement is changed. A Δdelta arrangement method as shown in FIG. 7 is required, and therefore, the above-mentioned double speed driving method must be adopted. For this reason, there is a problem that the drive system becomes complicated due to the double speed drive processing, the power consumption increases, the cost increases, and the liquid crystal projector becomes large in size. Further, there is a trade-off relationship between higher resolution and improvement in brightness, and if the number of pixels is increased for full line display, the pixel aperture area cannot be sufficiently secured and brightness decreases. The single-plate type liquid crystal projector using one liquid crystal panel as described above has a problem that sufficient brightness cannot be ensured for the above-mentioned reason.

The present invention has been made in consideration of the above points, and the vertical resolution is lowered in the two-line driving method which is a driving method of the liquid crystal projector, the necessity of adding hardware in the double speed driving method, and An object of the present invention is to provide a liquid crystal display device and a liquid crystal display method in which problems such as insufficient brightness in the plate system are improved.

[0017]

A liquid crystal display device according to claim 1, wherein a display image of the first liquid crystal display device based on the first image data and a second image different from the first image data. A display image of the second liquid crystal display device based on the data,
An image synthesizing unit that superimposes each other to generate one display image is provided.

According to a second aspect of the present invention, there is provided a liquid crystal display device comprising: a first liquid crystal display device for displaying an image with first image data; and a second liquid crystal display device.
A second liquid crystal display device for displaying an image with the image data of 1., the first image data is image data for one field, the second image data is another field, and the first liquid crystal While writing image data to the display device,
The second liquid crystal display device is a liquid crystal display device which holds the image data written in the immediately preceding field and repeats this operation alternately for each field.

In the liquid crystal display device according to the third aspect, the first image data and the second image data have a phase difference of 90 degrees.

A liquid crystal display device according to a fourth aspect of the present invention comprises a vertical scanning circuit means for stopping the vertical scanning and holding the first image data and the second image data.

The liquid crystal display device according to claims 5 and 6 is
It is applied to at least a liquid crystal projector, and this liquid crystal projector is separated by a light source, a P / S separation unit that separates the light emitted from the light source into P / S polarized components, and the P / S separation unit. The P → S conversion means for converting the P polarization component into the S polarization component, the first S polarization component is transmitted through the first liquid crystal display device, and the S polarization component converted by the P → S conversion means is converted into the second polarization component. And a synthesizing means for synthesizing S-polarized light components which are transmitted through the liquid crystal display device and synthesize and illuminate these transmitted lights.

According to a seventh aspect of the liquid crystal display method, a display image of the first liquid crystal display device based on the first image data,
It is a liquid crystal display method in which a first image data and a display image of a second liquid crystal display device based on second image data different from each other are superimposed on each other to display one image.

The liquid crystal display method according to claim 8 includes a first liquid crystal display device for displaying an image with the first image data and a second liquid crystal display device for displaying an image with the second image data. The first image data is image data for one field, the second image data is another field, and the second liquid crystal display is displayed while the image data is being written in the first liquid crystal display device. The device is a liquid crystal display method in which the image data written in the immediately preceding field is held and this operation is alternately repeated for each field.

The liquid crystal display method according to a ninth aspect is a liquid crystal display method in which the first image data and the second image data have a phase difference of 90 degrees.

A liquid crystal display method according to a tenth aspect of the present invention is a liquid crystal display method in which the first image data and the second image data are held by stopping the vertical scanning.

The liquid crystal display device according to the eleventh and twelfth aspects is applied to at least a liquid crystal projector, and this liquid crystal projector separates a light source and light emitted from the light source into P and S polarized components. P / S separation means, P → S conversion means for converting the P polarization component separated by the P / S separation means into S polarization component, and the first S polarization component is transmitted through the first liquid crystal display device, This is a liquid crystal display method in which the S-polarized component converted by the P → S conversion means is transmitted through the second liquid crystal display device, and these transmitted lights are combined and irradiated.

[0027]

In the liquid crystal display device of the present invention, since the first liquid crystal display device and the second liquid crystal display device are combined with a phase difference of 90 degrees, the display image of each liquid crystal display device is Overlapping, high-definition images can be reproduced. Further, since the image data is written in the liquid crystal display device for each field, it is possible to stably synthesize one image into one image.

Further, the liquid crystal display device is applied to at least a liquid crystal projector, and this liquid crystal projector separates the light emitted from the light source into P and S polarization components, and the first S polarization component is the first liquid crystal. The S-polarized light component, which was originally discarded as the P-polarized light component, is transmitted through the display device, and then P → S
Since the conversion means is used most to transmit the light through the second liquid crystal display device, the light utilization efficiency of the light source is improved, and a high brightness liquid crystal projector can be realized.

Further, in the liquid crystal display method of the present invention, the first liquid crystal display device and the second liquid crystal display device are combined with a phase difference of 90 degrees. Display images can be superimposed on each other to reproduce a high-definition image. Further, since the image data is written in each liquid crystal display device for each field, a stable composite image can be displayed.

This liquid crystal display method is effective when applied to at least a liquid crystal projector, and this liquid crystal projector separates the light emitted from the light source into P and S polarization components, and the first S polarization component is the first. Since the P-polarized light component that was originally discarded is converted into the S-polarized light component by the P → S conversion means and transmitted to the second liquid crystal display device, a brighter liquid crystal projector can be realized. .

[0031]

Embodiments of the liquid crystal display device and the liquid crystal display method according to the present invention will be described below with reference to FIGS. The same parts as those of the conventional liquid crystal display device are designated by the same reference numerals, and the description of their structures and operations will be omitted.

First Embodiment First, a first embodiment in which the liquid crystal display device and the liquid crystal display method of the present invention are applied to a liquid crystal projector will be described with reference to FIG. FIG. 1A is a diagram showing an example of an optical system of a liquid crystal projector of the present invention, and FIG. 1B is a diagram showing a pixel array of a liquid crystal panel used in the liquid crystal projector of the present invention.

In FIG. 1A, a light source 10 composed of, for example, a metal halide lamp or a reflector (reflecting mirror).
, The first half mirror 11, the mirror 12, the first liquid crystal panel 13 on which the transmitted light of the first half mirror 11 is incident, the second liquid crystal panel 14, the mirror 15,
The second half mirror 16 and a projection lens 17 for enlarging and projecting an image on a screen are provided.
In the optical system of this embodiment, an example in which one light source is used has been shown, but it is a matter of course that two light sources may be used and the half mirror may be a prism or the like. Absent. Further, the half-line driving liquid crystal panel used in the liquid crystal projector has a pixel arrangement as shown in FIG. That is, for example, the pixel group in the white part in FIG. 2B is that of the first liquid crystal panel 13, and the pixel group in the shaded part is that of the second liquid crystal panel 14. The optical system of the liquid crystal projector has a pixel arrangement in which the pixel group of the first liquid crystal panel 13 and the pixel group of the second liquid crystal panel 14 are shifted by half a pixel in the vertical direction as shown in FIG. It is arranged as follows.

The light emitted from the light source 10 is separated by the first half mirror 11, half of the light is incident on the first liquid crystal panel 13 as transmitted light, and half of the light is reflected light via the mirror 12 to the second. Is incident on the liquid crystal panel 14.
Pixel group of first liquid crystal panel 13 and second liquid crystal panel 14
The pixel groups of are arranged so as to be displaced by half a pixel in the vertical direction as described above. For example, an image of the first field is written on the first liquid crystal panel 13, and an image of the second field is written on the second liquid crystal panel 14, which are alternately applied for each field to be fully interlaced. Frame display is possible. Furthermore,
The light transmitted through the first liquid crystal panel 13 is reflected by the mirror 15 and is incident on the second half mirror 16. Similarly, the light transmitted through the second liquid crystal panel 14 is incident on the second half mirror 16, and the images of the first liquid crystal panel 13 and the second liquid crystal panel 14 are as shown in FIG. An image projected on a pixel is enlarged by the projection lens 17 and projected on the screen. In this way, if two liquid crystal panels with 240 vertical pixels are used,
A total of 480 vertical displays can be realized (NTSC
Frame display). Also, by using two liquid crystal panels having 480 vertical pixels, it is possible to easily realize 960 vertical pixels.

An embodiment of the liquid crystal display device and the liquid crystal display method of the present invention will be described with reference to FIG.

The shaded portion in FIG. 2 shows the image of the first liquid crystal panel, and the white portion shows the image of the second liquid crystal panel.
The mark with a circle indicates that the data is held data, and the mark without a circle indicates that the data is write data. In the figure,
Assuming that writing is started from the l field, a + direction image signal is applied to the n line which is an image of the first liquid crystal panel, and a − direction image signal is applied to the n + 1 line. Then, in the l + 1 field, the write data of the video signals n and n + 1 lines of the l field described above is stored as holding data, and a new line is newly added to the m and m + 1 lines of the video of the second liquid crystal panel. The negative-direction and + -direction video signals of opposite phases are respectively applied. In the l + 2 field, the video signal written in the above-mentioned l + 1 field is held as holding data, while the video signals in the negative and negative directions, which are in opposite phase to the previous time, are stored in the n and n + 1 lines of the first liquid crystal panel. Each is applied.
Further, in the l + 3 field, while the video signal written in the above-mentioned l + 2 field is held as holding data, the video signals in the + direction and − direction of the opposite phase to the previous time are stored in the m and m + 1 lines of the second liquid crystal panel. Each is applied. Thereafter, similarly, the liquid crystal panels are driven while the opposite-phase video signals are applied to the first liquid crystal panel and the second liquid crystal panel for each field while being held for each field.

A timing chart of the liquid crystal display device and the liquid crystal display method of the present invention will be described with reference to FIGS. 3 and 4.

In FIG. 3, the start pulse VST of the first liquid crystal panel and the second pulse alternately generated for each field.
The operation is started with the start pulse VST of the liquid crystal panel as the reference. It can be seen that the polarity inversion signal of the first liquid crystal panel shown in the same figure has its polarity inverted every VST generated every two fields as shown in FIGS. Similarly, the polarity inversion signal of the second liquid crystal panel is inverted every VST generated every two fields with a shift of one field from VST of the first liquid crystal panel as shown in FIGS. I understand.

FIG. 4 shows, as an example, visual characteristics of a liquid crystal panel driven by the liquid crystal display method of the present invention, which is converted into an electric signal by a photomultiplier (photoelectron amplifier tube), and the electric signal is converted by an oscilloscope or a spectrum analyzer. It is the observed waveform diagram, the figure (a) is a video signal applied to the n, n + 1 line of the first liquid crystal panel, the figure (b) is applied to the m, m + 1 line of the second liquid crystal panel (C) is the total transmissivity visually recognized by combining.

In FIG. 4A, the video signal applied to the n-line shows the transmittance as shown in the second stage of FIG. 4A because the video signal for two fields is held. Similarly, an image signal having a phase opposite to that of the n line is applied to the n + 1 line, and its transmittance shows the same transmittance. The combined transmittance of the first liquid crystal panel in which these n and n + 1 lines are combined has a waveform having a cycle of 30 Hz as shown in the figure, and flicker is visually observed as it is.

On the other hand, in FIG. 6B, the video signal applied to the m line shows the transmittance as shown in the second stage of FIG. 6B because the video signal for two fields is held.
Similarly, an image signal having a phase opposite to that of the m line is applied to the m + 1 line, and its transmittance shows the same transmittance. The combined transmittance of the second liquid crystal panel in which the m and m + 1 lines are combined has a waveform having a cycle of 30 Hz as shown in the figure, and flicker is visually observed as it is. However, as shown in the figure, the combined transmittance of the first liquid crystal panel and the combined transmittance of the second liquid crystal panel are deviated from each other by one field. Therefore, the combined transmittance of FIG. , A waveform having a cycle of 60 Hz. For this reason, the change in the visual luminance becomes a 60 Hz cycle and no flicker is felt.

Embodiment 2 This embodiment is an example in which the optical system of the liquid crystal projector in Embodiment 1 is left as it is and another arrangement method is adopted instead of the pixel arrangement method of the liquid crystal panel in Embodiment 1. This will be described with reference to FIG.

In FIG. 5, a half-line-driving liquid crystal panel used in the liquid crystal projector of the present embodiment is shown in FIG.
3, the pixel group in the shaded area is the second liquid crystal panel 1
4 of them. In the optical system of the liquid crystal projector, the pixel groups of the first liquid crystal panel 13 and the pixel groups of the second liquid crystal panel 14 are, as shown in FIG. They are arranged in an array. By arranging the pixels in this way, not only the vertical resolution can be improved, but also the horizontal resolution can be simultaneously improved.

Example 3 This example is an example in which another optical system is adopted in place of the optical system of the liquid crystal projector in Examples 1 and 2, and this will be described with reference to FIG.

In FIG. 6, the light source 10 including, for example, a metal halide lamp, the P / S separator 21, and the P → S are shown.
It comprises a converter 22, a first liquid crystal panel 13, a second liquid crystal panel 14, a mirror 23, a synthesizer 24, a projection lens 17 for enlarging and projecting an image on a screen, and the like.

The light emitted from the light source 10 is P · S.
The separator 21 separates the P-polarized light and the S-polarized light.
The S-polarized light separated by the P / S separator 21 travels straight and is incident on the first liquid crystal panel 13, and the P-polarized light is P
→ The light enters the S converter 22. The P → S converter 22 is an optical element that converts the incident P-polarized light into S-polarized light, which is converted into S′-polarized light and then as S′-polarized light on the second liquid crystal panel 14. It is incident. The first
The S-polarized light transmitted through the liquid crystal panel 13 is incident on the combiner 24, and similarly S ′ transmitted through the second liquid crystal panel 14.
The polarized light is incident on the combiner 24 via the mirror 23. In this manner, the image displayed on the first liquid crystal panel 13 and the image displayed on the second liquid crystal panel 14 are combined by the synthesizer 24.
After being combined as S-polarized light in, it is enlarged by the projection lens 17 and projected on the screen. The characteristic part of the present invention is to use two high aperture ratio liquid crystal panels and use the first separated S-polarized light for the first liquid crystal panel 13,
→ The new S′-polarized light that has been S converted is used for the second liquid crystal panel 1
By using it for 4, the high resolution and high definition (full line display) by the two-panel color liquid crystal panel, low cost,
It aims to realize a liquid crystal projector that enables low power consumption and miniaturization.

The present invention is not limited to the above embodiments, and various embodiments can be adopted. For example, in the above-described embodiment, the case where the invention is applied to a transmissive liquid crystal projector is described as an example, but it is needless to say that it is also effective for a reflective liquid crystal projector using a reflective liquid crystal panel and a rear projector in which an optical system is arranged behind a screen. . Further, the present invention is not limited to the liquid crystal projector, and is also effective for other liquid crystal display devices that are expected to have higher definition and higher brightness. Further, it is needless to say that the liquid crystal mode method is not particularly limited and can be applied to ferroelectric liquid crystal and other display devices.

[0048]

As described above, according to the liquid crystal display device and the liquid crystal display method of the present invention, a composite image is formed using two conventional liquid crystal panels having a vertical resolution of 240 in the vertical direction. Therefore, it is possible to realize a high-resolution liquid crystal projector with a vertical resolution of approximately 350 to 400 TV lines without worrying about flicker. Also,
Since the liquid crystal display device used in the present invention is an existing half-line drive liquid crystal display device, a special driving method such as a two-line simultaneous driving method or a double speed driving method is unnecessary, and power consumption can be reduced. Further, since the liquid crystal display device is an existing liquid crystal display device, no special manufacturing device or manufacturing method such as fine process is required, so that the manufacturing process can be simplified and the cost of the liquid crystal display device can be reduced.

Further, since the liquid crystal display method of the present invention does not require a special driving method, the liquid crystal panel is not limited to the pixel arrangement such as the stripe arrangement or the delta arrangement, and any liquid crystal panel can be used. is there.

Further, since the liquid crystal projector of the present invention uses a half line driven liquid crystal display device, it has a pixel aperture larger than that of a single plate type liquid crystal projector using one full line driven liquid crystal panel. The rate can be increased. Therefore, it is possible to increase the brightness by about four times that of the single-plate type liquid crystal projector. Furthermore, by reusing the P / S polarized light as the light input to the two liquid crystal panels, it is possible to realize the brightness of about 8 times that of the single-panel liquid crystal projector.

[Brief description of drawings]

FIG. 1 is a diagram showing a first embodiment in which a liquid crystal display device and a liquid crystal display method of the present invention are applied to a liquid crystal projector, FIG. 1A is a diagram showing an example of an optical system of the liquid crystal projector, and FIG. 8] is a diagram showing a pixel array of a liquid crystal panel used in a liquid crystal projector.

FIG. 2 is a diagram for explaining an operation of writing a video signal for each field in the liquid crystal projector of the present invention.

FIG. 3 is a timing chart diagram for explaining the operation of the liquid crystal projector of the present invention.

FIG. 4 is a diagram showing a driving method of a liquid crystal projector of the present invention, in which (a) is a video signal applied to lines n and n + 1 of the first liquid crystal panel, and (b) is a second liquid crystal panel. Is a video signal applied to the m and m + 1 lines of
(C) is the total transmittance that is visually recognized by combining.

FIG. 5 is a diagram showing a pixel array of a liquid crystal panel used in a second embodiment of the liquid crystal projector of the present invention.

FIG. 6 is a diagram showing an optical system used in a third embodiment of the liquid crystal projector of the present invention.

FIG. 7 is a block diagram showing a conventional liquid crystal display device and liquid crystal display method, and a diagram schematically showing a pixel portion.

FIG. 8 is a diagram for explaining an operation of writing a video signal for each field into a liquid crystal projector of the related art.

FIG. 9 is a timing chart diagram for explaining the operation of the conventional liquid crystal projector.

[Explanation of symbols]

 DESCRIPTION OF REFERENCE NUMERALS 1 conventional liquid crystal display device 2 external signal generator 3 liquid crystal panel 4 vertical scanning circuit 5 horizontal scanning circuit 10 light source 11 first half mirrors 12, 15, 23 mirror 13 first liquid crystal panel 14 second liquid crystal panel 16 Second half mirror 17 Projection lens 21 P / S separator 22 P → S converter 24 Combiner

Claims (12)

[Claims] 1. A first for displaying an image with first image data
And a second liquid crystal display device that displays an image with the second image data, and displays the display image of the first liquid crystal display device and the display image of the second liquid crystal display device. A liquid crystal display device comprising a combining means for superimposing and displaying one image. 2. A first for displaying an image with the first image data
And a second liquid crystal display device for displaying an image with the second image data, wherein the first image data is one field and the second image data is another one. This is a field, and while the image data is being written in the first liquid crystal display device, the second liquid crystal display device holds the image data written in the immediately preceding field, and the above-described operation is alternately repeated for each field. A liquid crystal display device characterized by the above. 3. The liquid crystal display device according to claim 1, wherein the first image data and the second image data have a phase difference of 90 degrees. 4. The first image data and the second image data are held by stopping vertical scanning in the vertical scanning circuit means. Liquid crystal display device. 5. The liquid crystal display device according to claim 1, wherein the liquid crystal display device is applied to at least a liquid crystal projector. 6. The liquid crystal projector according to claim 5, wherein the light source, the P / S separation means for separating the light emitted from the light source into the P / S polarization components, and the P / S separation means are used. P → S to convert P polarization component to S polarization component
A conversion means and a combining means for combining the S-polarized components,
The first S-polarized component is transmitted through the first liquid crystal display device, and the S-polarized component converted by the P → S converter is the second S-polarized component.
2. The liquid crystal display device, wherein the liquid crystal display device is transmitted through the liquid crystal display device, combined by the combining means, and irradiated. 7. A first for displaying an image with the first image data
Liquid crystal display device, a second liquid crystal display device for displaying an image with the second image data, and a synthesizing unit for synthesizing the image, and the display image of the first liquid crystal display device and the second liquid crystal display A liquid crystal display method characterized by displaying a single image by superimposing a display image of the device. 8. A first for displaying an image with the first image data
Liquid crystal display device and a second liquid crystal display device for displaying an image with the second image data, wherein the first image data is one field and the second image data is another field. Therefore, while the image data is being written in the first liquid crystal display device, the second liquid crystal display device holds the image data written in the immediately preceding field, and repeats the above operation alternately for each field. Characteristic liquid crystal display method. 9. The liquid crystal display method according to claim 7, wherein the first image data and the second image data have a phase difference of 90 degrees. 10. The method according to claim 7, wherein the first image data and the second image data are held by stopping vertical scanning in the vertical scanning circuit means. LCD display method. 11. The liquid crystal display method according to claim 7, wherein the liquid crystal display device is applied to at least a liquid crystal projector. 12. The liquid crystal projector according to claim 11, wherein a light source, a P / S separation means for separating the light emitted from the light source into P / S polarization components, and a P / S separation means are used. P to convert P polarization component to S polarization component →
An S conversion means and a combining means for combining the S polarization components are provided. The first S polarization component is transmitted through the first liquid crystal display device, and the S polarization component converted by the P → S conversion means is converted into the second polarization component. 2. A liquid crystal display method, wherein the liquid crystal display device is transmitted through the liquid crystal display device, combined by the combining means and irradiated.