JP2002175061A - Display device and its drive method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a display method having enhanced vertical resolution. SOLUTION: At a stage when a first field is ended, a second field is started, while maintaining information written in the first field. At a stage when the second field is ended, a first field of a next frame is started, while maintaining information written in the second field. Furthermore, two fields are constituted by different image forming devices and then are composited and are projected. Thereby vertical resolution can be enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display method in an active matrix type display device represented by an active matrix type liquid crystal display device.

[0002]

2. Description of the Related Art Conventionally, an active matrix type liquid crystal display device has been known. This has a configuration in which a switching thin film transistor and a non-linear element are arranged in each of the pixels arranged in a matrix to control the charge flowing into and out of the pixel electrode.

Generally, as a display method in an active matrix type liquid crystal display device, a display method in which one frame is divided into a first field and a second field is used. In this method, as shown in the timing chart of FIG. 1, information is first written to odd-numbered rows for pixels arranged in a matrix of m rows and n columns as shown in FIG. Is displayed, and this is set as a first field. Then, information is written to the even-numbered rows, and this is set as a second field. Thus, one frame is composed of the first field and the second field.

Specifically, in the matrix area shown in FIG. 4, information is not sequentially written to the rows (1, 1), (2, 1), (3, 1),. 1,3), (2,3)... The information is not sequentially written to the rows, the first field, and then (1,2), (2,2), (3,2) .. Are not sequentially written, and furthermore, the information is not sequentially written to the (1,4), (2,4). Then, when writing of information to all the pixels is completed, one frame ends. The display is performed by repeating this frame 30 times per second.

The above method is employed to suppress the flickering that occurs when a bright screen is displayed. This flicker is felt when the vertical scanning time is long. Therefore, by constituting one frame with two fields as described above, the apparent vertical scanning time is reduced to half and the flicker is suppressed.

There is another reason that the above-described method is employed to reduce the amount of information required for one frame.

However, in the display by the above-described method, the number of scanning lines is substantially 2 / n, so that there is a problem that the vertical resolution is reduced.

In particular, in a method of performing display by projecting a large screen like a projector, other fields that are not displayed are displayed.
There is a problem that the non-display part is observed. This is a major factor in lowering the vertical resolution.

[0009]

SUMMARY OF THE INVENTION An object of the invention disclosed in this specification is to provide a configuration in which the vertical resolution does not decrease even when the above-described scanning method is adopted.

[0010]

Means for Solving the Problems One of the inventions disclosed in the present specification has means for projecting images divided into two groups on a projection plane so that the projected images are arranged in a matrix. , N is an odd number represented by 1, 3, 5,..., And the Nth row is formed on one group of images on the projection plane, and the N + 1th row is formed on the other side. In the group of images.

FIG. 3 shows a specific example of the above configuration. FIG.
3 has a configuration in which six images formed by the six active matrix regions shown in FIG. 2 are divided into two groups, and the two groups are projected from the optical system 508 onto the screen 510.

The display device shown in FIG. 3 includes an integrated liquid crystal panel 507 whose outline is shown in FIG. 50
In the integrated liquid crystal panel shown by reference numeral 7, 20 in FIG.
For example, the N-th row image is formed in the active matrix areas indicated by 1 to 203. And 204
N + 1 in the active matrix area
An image on the line is formed.

According to another aspect of the present invention, there is provided an apparatus for performing a display in which one frame is composed of a first field and a second field, wherein the image forming means for forming the first field; Image forming means for forming two fields.

FIG. 2 shows a specific example of the above configuration. In the configuration shown in FIG. 2, the first field is formed in the active matrix areas 201 to 203, and the fields 204 to 206 are formed.
The second field is formed in the active matrix region indicated by.

In particular, as shown in FIG. 1, information writing (image display) is performed by one image forming means in a period indicated by the first field, and when the writing is completed, the other image forming means performs the writing of information. An image of the second field is formed. At this time, while the display of the second field is being performed, the image of the first field is kept as it is. Then, the apparent vertical resolution can be increased.

Another aspect of the invention is a method of writing information to each pixel of a display screen arranged in a matrix,
The images divided into two groups are combined and projected, and N is set to 1, 3,
It is characterized in that the formation of the N-th row on the projection plane is performed by the image of one group and the formation of the (N + 1) -th row is performed by the image of the other group as odd numbers indicated by 5.

According to another aspect of the present invention, in a display method in which one frame is composed of a first field and a second field, the first field and the second field are composed of different image forming apparatuses. It is characterized by.

[0018]

Embodiment 1 FIG. 2 shows an outline of an integrated liquid crystal panel used in this embodiment. The configuration shown in FIG. 2 forms the first image of RGB in the active matrix areas 201 to 203, and
A function of forming a second image of RGB in the active matrix area indicated by reference numeral 06 is provided.

The active matrix regions 201 and 2
The horizontal scanning of 03 is controlled by a horizontal scanning control circuit 207 disposed in common. The horizontal scanning of the active matrix areas 204 to 206 is controlled by a horizontal scanning control circuit 208 which is arranged in common.

The horizontal scan control circuits 207 and 208 have their operation timing controlled by the vertical scan timing, and operate so as to form images of the first field and the second field. That is, the image formed by the active matrix areas 201 to 203 forms the first field of FIG.
The image formed at 206 forms the second field of FIG. Then, one frame is formed by the first field and the second field.

The active matrix areas 201 and 2
04 is commonly controlled by the vertical scanning control circuit 209. Also, active matrix areas 202 and 205
Are commonly controlled by the vertical scanning control circuit 210. The active matrix areas 203 and 206
Commonly controlled by the vertical scanning control circuit 211.

Such a configuration can simplify the configuration of the liquid crystal panel, and can increase its production cost and reliability.

In the configuration shown in FIG. 2, a circuit indicated by 102 is a flip-flop circuit. This circuit has a function of stably maintaining one of the two states.

For example, when the rising edge of the operation clock signal is input while the input level is H, the output level becomes H. When the rising edge of the operation clock signal is input while the input level is L, the output level becomes L
Becomes Then, these states are maintained unless a rising edge of the next operation clock signal is input.

In the configuration shown in FIG.
An H-level signal (vertical scanning timing enable signal) is applied to the input of the flip-flop circuit. In this state, the rising edge of CLKV (operating clock of the vertical scanning control circuit) is input to the flip-flop circuit 102.

Then, in the flip-flop circuit 102, VSTA is punched out by CLKV, and the signal level of the gate line 103 becomes H level. That is, when the input of the flip-flop circuit 102 is at the H level and the rising edge of CLKV is input, the output of the flip-flop circuit 102 is at the H level.

When the gate signal line 103 becomes H level, the gate signal line 103 is arranged at a pixel at each address indicated by (0,0), (1.0), (2,0)... (M, 0). Thin film transistor is ON
Operation.

In this state, HSTA (horizontal scanning timing enable signal) is punched out by the rising edge of CLKH (operation clock of the horizontal scanning control circuit) in the flip-flop circuit 104. As a result, the signal level of the image sampling signal line 105 becomes H.

Then, the sampling hold circuit 106 captures the image data, and the image data flows into the image signal line 107. In this state, (0,0),
Since the thin film transistors in the rows indicated by (1,0), (m, 0)... Are all ON, the image data is written at the address indicated by (0,0).

Next, at the next rising edge of CLKH, the output of flip-flop circuit 108 goes high,
The output of the flip-flop circuit 104 goes low.
That is, when the input portion of the flip-flop circuit 108 (the output portion of the flip-flop circuit 104) is at H level, C
When the next rising edge of LKH is input, the output of the flip-flop circuit 108 changes to H level. At this time, the output of the flip-flop circuit 104 changes to L level.

As a result, the image sampling signal line 109
Becomes H level. Further, the image data is captured by the sampling and holding circuit 110, and the image data is supplied to the image signal line 111.

As a result, information is written at the address (1,0). In this manner, information is sequentially written up to the pixel at the address (m, 0). Thus, the writing of information to the first row is performed.

Next, the output of the next flip-flop circuit of the vertical scanning control circuit becomes H level, and (0, 1), (1, 1).
Writing of information to the address (m, 0) is performed. Then, when the writing of the information up to the address (m, n) is completed, 1
Writing of the field information is completed.

During the above operation, the HSTA is not input to the horizontal scanning control circuit indicated by 208, and the operation is not performed. Therefore, the above operations are performed at 201 to 203
This is performed similarly in the active matrix region indicated by.

When the writing of information to all the pixels in the active matrix areas 201 to 203 is completed, the horizontal scanning control circuit 208 is controlled by the timing of VSTA (vertical scanning timing enable signal).
To the state where the HSTA signal is added. Then, information is written to the first rows of the active matrix areas 204 to 206.

The writing of this information is sequentially performed on all the pixels in the active matrix areas 204 to 206. As a result, the information of the second fold is written.

In this manner, the information of the RGB fields is written alternately. When writing the information of one field, the information written in the other fields is maintained. Therefore, the display is performed at the operation timing as shown in FIG.

In this way, the number of scanning lines in the vertical direction is not reduced, so that the vertical resolution can be improved.

FIG. 2 shows an example in which six active matrix areas are integrated. However, it is not possible to integrate active matrix areas such as 2 × 1, 3 × 3, and 4 × 2. It is possible.

In general, the number of active matrices is M × N
In the case of the number, the required number of horizontal scanning control circuits and vertical scanning control circuits may be M + N in total. Such a structure, in combination with a structure integrated over the same substrate, can provide significance such as reduction in manufacturing cost and improvement in reliability.

[Embodiment 2] This embodiment is an example of a projection type display device using an integrated liquid crystal panel shown in FIG. FIG. 3 shows an outline of the present embodiment. In FIG. 3, 5
Reference numeral 00 denotes a housing of the apparatus, and an image enlarged and projected from the inside is displayed on a screen 510 disposed in the housing 500.

Here, a configuration in which an image is viewed from the side opposite to the surface projected on the screen (generally called rear projection) is shown, but a configuration in which the image is viewed from the surface projected on the screen (generally a projection type). Projection), the basic configuration is the same except that the image is inverted. However, in the case of the projection type projection, the difference is that the case and the screen are not integrated.

In the housing 500, an appropriate control circuit 5 is provided.
For example, control of image display and selection of a two-dimensional image and a three-dimensional image are performed.

In FIG. 5, a light source 501 for emitting white light is shown.
Is reflected by the half mirror 502 first,
GBR with dichroic mirrors 504, 505, 506
Is split into light having a wavelength region corresponding to

The light reflected by the mirror 503 is also converted to B (blue) G by a dichroic mirror (not shown).
(Green) The light is separated into R (red) wavelength regions. That is, two sets of RGB dichroic mirrors make two sets of R dichroic mirrors.
GB rays (6 rays in total) are generated.

These light beams are incident on an integrated liquid crystal panel 507 whose outline is shown in FIG. Then, two sets of RGB images formed by optical modulation by the integrated liquid crystal panel 507 are projected from the optical system 508 via a mirror 509 to a screen (projection plane) 510, where they are combined as a color image. Is done.

The optical system 508 incorporates a lens system for magnifying projection and a polarizing means (usually a polarizing plate is used) used for stereoscopic display (three-dimensional display). In the case of ordinary two-dimensional display, this polarization imparting means only functions as a simple dimming means. Therefore, there is no particular problem other than lowering the display luminance. But,
If it is desired to increase the luminance during two-dimensional display, this polarization imparting means may be mechanically removed from the optical path.

When a display device as shown in this embodiment is used, a bright image can be displayed with a high resolution.

[0049]

By adopting the method disclosed in the present specification, it is possible to obtain a structure with an improved vertical resolution.

[Brief description of the drawings]

FIG. 1 is a chart showing display timing.

FIG. 2 is a schematic view illustrating a configuration of an integrated liquid crystal panel.

FIG. 3 is a diagram schematically illustrating a projection display device.

FIG. 4 is a schematic diagram showing a pixel arrangement in a matrix region.

[Explanation of symbols]

 201, 202, 203 Active matrix area 204, 205, 206 Active matrix area 207, 208 Horizontal scanning control circuit 209, 210, 211 Vertical scanning control circuit 104, 108, 102 Flip-flop circuit 501 Light source 502 Half mirror 503 Mirror 504, 505 , 506 Dichroic mirror 507 Integrated liquid crystal panel 508 Optical system 509 Mirror 510 Screen 511 Control circuit

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) H04N 5/74 H04N 5/74 A K (72) Inventor Shunpei Yamazaki 398 Hase, Atsugi-shi, Kanagawa Pref. F-term in the laboratory (reference) 2H088 EA12 HA13 MA20 2H093 NA16 NA41 NC23 ND20 NE06 5C006 AF44 BB14 BB16 BC20 BF11 EC11 5C058 AA08 BA02 BA24 BA25 BA35 EA11 EA26 5C080 AA10 BB06 DD07 FF11 JJ03 JJ04 JJ04 JJ04 JJ04 JJ06

Claims (11)

[Claims] A first group of active matrix regions and a second group of active matrix regions;
A liquid crystal panel including a group of active matrix regions, wherein one frame image is composed of a first field image and a second field image, wherein the first group active matrix region and the second group active matrix One of the regions is a display device that forms an image of the first field, and the other is a display device that forms an image of the second field. The image of the first field is a video signal input to a first group of active matrix regions. The image of the second field is formed by inputting the video signal to a second group of active matrix areas, and the image of the first field and the image of the second field are projected. Forming a single image by being projected onto a surface, wherein the first group of active matrix regions and the second group of active matrix regions are formed. At the same time as the end of one frame period, the next frame period is started in the risk region, and the period during which the video signal is written in the first group of active matrix regions and the second group of active matrix regions is 1 / In a two-frame period, the writing of the video signal is started in the active matrix area of the second group after a half frame period in which the writing of the video signal is started in the active matrix area of the first group. The image displayed in the first group of active matrix areas is maintained until the end of the writing of the video signal in the second group of active matrix areas, and is displayed in the second group of active matrix areas. The video signal is written in the first group of active matrix areas. Display device characterized in that it is maintained up to the point where only terminates. 2. The display according to claim 1, further comprising a first group of optical systems for projecting the image of the first field, and a second group of optical systems for projecting the image of the second field. apparatus. 3. An image according to claim 1, wherein one of the image of the first field and the image of the second field is an image of an odd-numbered row on the display screen, and the other is an image of an even-numbered row on the display screen. A display device, comprising: 4. The display device according to claim 1, wherein the first group of active matrix regions and the second group of active matrix regions have a plurality of pixels provided in a matrix. 5. The display device according to claim 4, wherein each of the plurality of pixels has a liquid crystal element. 6. A projector comprising the display device according to claim 1. 6. A projector comprising the display device according to claim 1. Description: 7. A first group of active matrix regions and a second group of active matrix regions.
A liquid crystal panel including a group of active matrix regions, wherein one frame image is composed of a first field image and a second field image, wherein the first group active matrix region and the second group active matrix One of the regions forms the image of the first field, and the other forms the image of the second field. The method for driving a display device, wherein the image of the first field is displayed on a first group of active matrix regions. The image of the second field is formed by inputting a signal, and the image of the second field is formed by inputting the video signal to a second group of active matrix areas. The image of the first field and the image of the second field are formed. Are projected onto the projection surface to form one image, and the first group of active matrix areas and the second group of In the active matrix area, one frame period ends, and at the same time, the next frame period starts. The period in which the video signal is written to the first group of active matrix areas and the second group of active matrix areas is one. / 2 frame period, and the writing of the video signal to the second group of active matrix areas starts 1/2 frame period after the writing of the video signal to the first group of active matrix areas has started. The image displayed in the first group of active matrix areas is maintained until the writing of the video signal is completed in the second group of active matrix areas, and is displayed in the second group of active matrix areas. The image being displayed is the image in the first group of active matrix areas. The driving method of a display device characterized by writing issue is maintained until the time of termination. 8. The display according to claim 7, wherein the image of the first field is projected by a first group of optical systems, and the image of the second field is projected by a second group of optical systems. How to drive the device. 9. The image according to claim 7, wherein one of the image of the first field and the image of the second field is an image of an odd line on the display screen, and the other is an image of an even line on the display screen. A method for driving a display device, the method comprising: 10. The display device according to claim 7, wherein the first active matrix region and the second active matrix region are provided with a plurality of pixels provided in a matrix. Method. 11. The method according to claim 10, wherein each of the plurality of pixels is provided with a liquid crystal element.