JP2003186454A - Planar display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a planar display device which can eliminate motion blur by suppressing the frequency of a multiple-speed scanning method low and without generating an image to be inserted between fields. <P>SOLUTION: In an odd-numbered field, an image signal of image data DATA is written to pixels corresponding to odd-numbered scanning lines 18 and an image signal for displaying black lines is written to pixels corresponding to even-numbered scanning lines 18. In an even-numbered field, an image signal of the image data DATA is written to the pixels corresponding to the even- numbered scanning lines 18 and an image signal for displaying black lines is written to the pixels corresponding to the odd-numbered scanning lines 18. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flat panel display device such as a liquid crystal display device, and more particularly to a flat panel display device suitable for displaying a moving image.

[0002]

2. Description of the Related Art When a moving image is displayed on a liquid crystal display device, there is a problem that a display defect such as an afterimage phenomenon occurs.

The first cause of this problem is that the response speed of the liquid crystal material used in the liquid crystal display device is slow, and the second is the display method of the liquid crystal display device.

Regarding the second cause, the following report has been made (1999 IEICE General Conference, SC-1, pp.207-208).

The second cause will be described in comparison with the display method of a liquid crystal display device and the display method of a cathode ray tube display device (hereinafter, CRT).

The CRT is an impulse type display device which emits light for a few milliseconds from the time when the electron beam hits the phosphor on the tube surface, whereas the liquid crystal display device has finished writing data to pixels. This is a hold-type display device that holds display light for one field period from the time to the next writing.

Therefore, the impulse-type display device C is used.
In RT, a display object is momentarily displayed at a position corresponding to time, whereas in a liquid crystal display device which is a hold type display device, an image of one field before is displayed until just before new writing. become. Therefore, when the moving image is displayed on the CRT, it is not visually recognized that the image displayed at a certain time point is overlapped with the previous image. However, when a moving image is displayed on the liquid crystal display device, the currently displayed image and the previously displayed image are visually recognized in an overlapping manner due to a visual time integration effect, which causes a problem of motion blur.

Therefore, in order to solve this problem, conventionally, by scanning the scanning line at a speed several times higher than the conventional scanning speed, a new image is written between each field to reduce motion blur. A multiple speed scanning method has been proposed.

However, this multi-speed scanning method has a problem that the frequency becomes high and a circuit scale increases because it is necessary to newly create an image to be inserted between fields.

In view of the above, the present invention provides a flat display device capable of eliminating a motion blur without requiring a large-scale image processing circuit while suppressing the frequency as low as possible in this multiple speed scanning method. Is.

[0011]

According to a first aspect of the present invention, a plurality of signal lines and scanning lines which are arranged orthogonally to each other and a switching element are arranged near an intersection of the signal lines and the scanning lines. An array substrate having a pixel electrode to be formed, a signal line drive circuit that supplies an image signal corresponding to input image data to the signal line, and the switching element to an ON state so that the image signal is supplied to the pixel electrode. In a flat display device having a scanning line driving circuit for supplying a writing gate signal to the scanning line, one frame is divided into a first field and a second field and alternately displayed. The image signal of the image data is written to the pixels corresponding to the odd-numbered scanning lines, and the image signal for displaying the specific pattern image is written to the pixels corresponding to the even-numbered scanning lines. In the second field, the image signal of the image data is written to the pixels corresponding to the even-numbered scanning lines, and the image signal for displaying the specific pattern image is written to the pixels corresponding to the odd-numbered scanning lines. It is a flat panel display device.

According to a second aspect of the present invention, a plurality of signal lines and scanning lines which are arranged orthogonally to each other and a pixel electrode which is arranged in the vicinity of an intersection of the signal lines and the scanning lines via a switch element are provided. The array substrate provided, a signal line driving circuit for supplying an image signal corresponding to the input image data to the signal line, a gate signal for writing the image signal in the pixel electrode by turning on the switching element, and the scanning In a flat panel display device having a scanning line driving circuit for supplying lines to the lines, the signal lines are arranged in n sets of three signal lines of R, G, and B, and one frame is set as a first field. An image signal of the image data is written to pixels corresponding to a predetermined number of signal lines in the first field and displayed alternately in the second field, and to the signal lines of other groups. Corresponding picture An image signal to display a specific pattern image writing, when the second field,
An image signal of the image data is written in a pixel in which an image signal for displaying a specific pattern image is written in the first field, and a specific pattern image is written in a pixel in which an image signal of the image data is written in the first field. It is a flat panel display device characterized by writing an image signal to be displayed.

According to a third aspect of the present invention, the image of the first field and the image of the second field are supplied to each of the pixels by a clock signal having a frequency twice that of the clock signal corresponding to the input image data. 3. The flat panel display device according to claim 1, wherein the flat display device according to claim 1 or 2.

According to a fourth aspect of the present invention, there is provided the flat display device according to the first or second aspect, wherein the specific pattern image is a black or white perfect raster.

In the flat panel display device of the present invention, the image signal of the image data is written to the pixels corresponding to the odd-numbered scanning lines in the first field, and the specific pattern is written to the pixels corresponding to the even-numbered scanning lines. An image signal for displaying an image is written, an image signal of image data is written to pixels corresponding to even-numbered scanning lines in the second field, and a specific pattern image is displayed at pixels corresponding to odd-numbered scanning lines. Write the image signal. By displaying the first field and the second field alternately to display one frame, it is possible to prevent motion blur and double the frequency.

The specific pattern image means a complete raster image of black, gray, white, or the like, or an image that looks like a single color image to human eyes.

Further, in the flat panel display device of the present invention, the image signal of the image data is written to the pixels corresponding to the signal lines for each predetermined number of sets in the first field, and the signal lines of the other sets are written. An image signal for displaying a specific pattern image is written in the pixel corresponding to, and in the second field,
An image in which an image signal of image data is written in a pixel in which an image signal for displaying a specific pattern image is written in the first field, and a specific pattern image is displayed in a pixel in which an image signal of image data is written in the first field It is for writing signals. Then, the first field and the second field are alternately displayed to display one frame, whereby motion blur can be prevented and the frequency can be doubled.

[0018]

DETAILED DESCRIPTION OF THE INVENTION An active matrix type liquid crystal display device 10 according to an embodiment of the present invention will be described below with reference to FIGS.

(1) Structure of Liquid Crystal Display Device 10 This liquid crystal display device 10 is provided with a liquid crystal panel 12 in which an effective display area is provided with color display pixels of UXGA specifications having a diagonal size of 15 inches, for example.

As shown in FIG. 1, the liquid crystal panel 12 includes (1600 × 3 (R, G, B)) signal lines 16 and 1200 scanning lines arranged orthogonal to the signal lines 16. 18 and a pixel electrode 2 arranged via a TFT 20 arranged in the vicinity of the intersection of each signal line 16 and scanning line 18.
2 is provided with the array substrate 14. Further, a counter electrode substrate (not shown) provided with a color filter arranged above the facing surface of the array substrate 14 with a predetermined gap, and a light modulation layer arranged between the array substrate 14 and the counter electrode substrate. And liquid crystal (not shown).

The liquid crystal display mode used here is as follows.
A fast response speed is preferable, such as a display mode using ferroelectricity or antiferroelectricity, or OCB (optically compensated).
d birefringence) is preferred.

Each of the scanning lines 18 is a gate of the TFT 20, each of the signal lines 16 is a drain of the TFT 20, and each of the pixel electrodes 22 is a source of the TFT 20.
They are electrically connected to each other, so that the scan line 1
The image signal Vs from the signal line 16 corresponding to the gate signal Vg supplied to 8 is written in the pixel electrode 22, and is displayed based on the potential difference between the pixel electrode 22 and the counter electrode.

The signal line 16 is connected to a source driver 24, and the source driver 24 D / A converts the digital image data signal DATA to obtain an analog image signal Vs.
Is supplied to the signal line 16.

The scanning line 18 is connected to the gate driver 28 and supplied with the gate signal Vg.

A liquid crystal controller 30 for controlling the source driver 24 and the gate driver 28 is provided.

From the liquid crystal controller 30 to the source driver 24, a horizontal clock signal XCLK, a horizontal start signal STH, and the above-mentioned image data signal DAT are sent.
A, the polarity inversion signal POL is supplied. Further, the vertical clock signal YCLK, the vertical start signal STV, and the output inhibition signal OE are supplied to the gate driver 28.

Further, the liquid crystal controller 30 is provided with a frame memory for storing one frame of image data. Then, the image data of one frame stored in this frame memory is converted into the horizontal clock signal X.
Reading is performed by the following method with a frame frequency having twice the frequency of CLK.

A detailed description will be given below.

The liquid crystal controller 30 divides one frame into two fields of odd-numbered scanning and even-numbered scanning, and reads them out alternately at a frame frequency twice the horizontal clock signal XCLK.

When reading an odd-numbered scan field (hereinafter referred to as an odd-numbered field), a black image signal is output so as to be written in a pixel corresponding to an even-numbered scan.

When an even-numbered scan field (hereinafter referred to as an even-numbered field) is read, a black image signal is output so as to be written in a pixel corresponding to an odd-numbered scan.

In this case, when the horizontal clock signal XCLK in the liquid crystal controller 30 is 60 MHz,
The frame frequency for reading these two fields is 12
0 MHz.

That is, in the conventional liquid crystal display device, the non-interlaced driving method is used, but in the driving method of this embodiment, the non-interlaced image data is stored in the frame memory and the interlaced driving is performed at the double frame frequency. It is a thing. In this case, the jumping line is displayed in black.

(2) Display Method of Moving Image A display method when the image data signal DATA of the moving image is input to the liquid crystal controller 30 will be described.

The liquid crystal controller 30 uses the image data DA
60M as horizontal clock signal XCLK corresponding to TA
Although the Hz signal is made to correspond, the frame frequency of the frame clock signal output to the source driver 24 is 120 MHz, which is twice the frequency as described above. Correspondingly, the frequencies of the horizontal start signal STH, the polarity inversion signal POL, the vertical clock signal YCLK, the vertical start signal STV, and the output inhibit signal OE are also doubled.

It is assumed that image data DATA which forms one frame of a moving image as shown in FIG. 2 is input to the liquid crystal controller 30. In this case, this image data DATA
The horizontal clock signal for displaying is 60 MHz.

The liquid crystal controller 30 stores the input image data DATA in a frame memory, divides it into even fields and odd fields, and outputs them at a frame frequency of 120 MHz. As a result, even fields and odd fields can be displayed alternately in one frame.

As shown in FIG. 3A, when an even field is displayed, a black image signal is written in the pixel corresponding to the odd scan line 18. In addition, image data DATA is stored in the pixels corresponding to the even-numbered scanning lines 18.
The image signal corresponding to is written.

As shown in FIG. 3B, an odd field is written in the next period. In this case, the image data D is written in the pixel corresponding to the odd scan line 18.
The image signal corresponding to ATA is written, and the image signal for displaying black is written to the pixels corresponding to the even-numbered scanning lines 18.

As a result, the image data DATA as shown in FIG. 2 is displayed during the period of one frame.

When a person views this image, the image shown in FIG. 2 is visually recognized without visually recognizing the black scanning line portion 18. Also, black lines will be displayed alternately in the two fields, and the human eyes will be in a state of being reset with respect to the previous image, so that even if a moving image is displayed, no motion blur can be seen. .

Furthermore, when this image is displayed, it can be displayed with a frame signal twice as large as the conventional horizontal clock signal, so that the circuit configuration is not complicated.

(Modification 1) In the above embodiment, the colors written in the pixels corresponding to the odd-numbered scanning lines 18 in the even field and the colors written in the pixels corresponding to the even-numbered scanning lines 18 in the odd field are Although it was black, the effect of resetting the image for the human eye can be obtained by using a gray color such as white instead.

(Modification 2) In the above embodiment, the scanning line 18
Is divided into even-numbered and odd-numbered, and black lines are alternately displayed, but instead of this, the following display method may be used.

As shown in FIG. 4, three signal lines for displaying R, G, B are set as one set, and an image corresponding to black and image data DATA in the first field is set for each set of scanning lines 18. The signals are written alternately, and in the second field, the image signal corresponding to the image data DATA and black are written in the opposite manner.

Even with this method, motion blur cannot be seen when a moving image is displayed.

(Modification 3) In Modification 2, the image signals of black and image data DATA are displayed for each set of signal lines, but black and image data DATA are displayed for each of a plurality of sets of signal lines. May be

In particular, as shown in FIG. 5, in the first field, the left screen is black and the right screen is the image data DAT.
In the second field, the left screen is image data DAT.
A may be set to A and the right screen may be displayed in black.

Even with this method, motion blur cannot be seen when a moving image is displayed.

(Modification 4) In the above embodiment, the liquid crystal controller 30 stores the input image data DATA in the frame memory, divides it into even fields and odd fields, and outputs them at a frame frequency of 120 MHz to obtain even numbers. When a field is displayed, processing such as writing a black image signal into pixels corresponding to odd-numbered scanning lines 18 is performed. Instead, the source driver 24 performs this processing. Good.

(Modification 5) Although the liquid crystal display device having a slow response speed has been described in the above embodiment, the organic E having a fast response speed is described.
Since the L display device is a hold type display device, it has the same problem as the liquid crystal display device. Therefore, the present invention can be applied to any hold-type flat display device such as an organic EL display device.

[0052]

According to the flat panel display device of the present invention, one frame is divided into the first field and the second field and displayed alternately, and a specific pattern image is displayed in a part of the first field, and the second field is displayed. In the first field, the image blurring DATA can be prevented by displaying the image data DATA in the part where black is displayed and displaying the black in the other part.

[Brief description of drawings]

FIG. 1 is a block diagram of a liquid crystal display device showing an embodiment of the present invention.

FIG. 2 is image data DATA input to a source driver.
FIG.

FIG. 3 (a) is a diagram showing even fields,
(B) is a figure which displayed the odd field.

FIG. 4 is a diagram in a second modification example, in which (a) is a diagram showing even fields and (b) is a diagram showing odd fields.

5A and 5B are diagrams in a modification example 3, where FIG. 5A is a diagram showing a first field, and FIG. 5B is a diagram showing a second field.

[Explanation of symbols]

10 Liquid crystal display device 12 LCD panel 14 Array substrate 16 signal lines 18 scan lines 20 TFT 22 Pixel electrode 24 Source Driver 28 Gate driver 30 LCD controller

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 2H093 NA16 NA44 NA64 NB07 NB11                       NC13 NC15 NC24 NC29 NC34                       NC41 NC49 ND01 ND60 NF04                       NF09 NF17 NF20 NH06 NH14                       NH15 NH16                 5C006 AA22 AF24 AF44 BB16 BC16                       FA34                 5C080 AA10 BB05 CC03 DD30 EE02                       EE26 FF11 JJ01 JJ02

Claims (4)

[Claims] 1. An array substrate comprising a plurality of signal lines and scanning lines arranged orthogonally to each other, and a pixel electrode arranged via a switch element in the vicinity of an intersection of the signal lines and the scanning lines. A signal line drive circuit for supplying an image signal corresponding to the input image data to the signal line, and a scan for supplying a gate signal for writing the image signal to the pixel electrode to the scanning line by turning on the switching element. A flat panel display device having a line driving circuit, wherein one frame is divided into a first field and a second field and alternately displayed, and a pixel corresponding to an odd-numbered scanning line is displayed in the first field. The image signal of the image data is written, the image signal for displaying a single color is written in the pixels corresponding to the even-numbered scanning lines, and the even-numbered scanning lines are written in the second field. The pixels respond write an image signal of the image data, flat panel display features to write an image signal to display a specific pattern image pixels corresponding to odd-numbered scanning lines. 2. An array substrate having a plurality of signal lines and scanning lines arranged orthogonally to each other, and a pixel electrode arranged via a switch element in the vicinity of an intersection of the signal lines and the scanning lines. A signal line drive circuit for supplying an image signal corresponding to the input image data to the signal line, and a scan for supplying a gate signal for writing the image signal to the pixel electrode to the scanning line by turning on the switching element. In a flat display device having a line driving circuit, the signal lines are arranged in n sets with three signal lines of R, G, and B as one set, and one frame is divided into a first field and a second field. Divided and displayed alternately, writing the image signal of the image data to the pixels corresponding to a predetermined number of signal lines in the first field,
An image signal for displaying a specific pattern image is written in the pixels corresponding to the signal lines of the other sets, and an image signal for displaying the specific pattern image in the first field is written in the second field. The image signal of the image data is written to the first pixel,
2. A flat display device characterized by writing an image signal for displaying a specific pattern image to a pixel to which an image signal of image data has been written in the field of. 3. A clock signal having a frequency twice that of the clock signal corresponding to the input image data,
3. The flat panel display device according to claim 1, wherein the image of the first field and the image of the second field are written in each of the pixels. 4. The specific pattern image is a complete raster of black or white.
The flat display device described.