JPS59160186A - Display - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a display panel such as a liquid crystal that can be used as a display device for character/graphic or image information.

Conventional configurations and their problems In recent years, flat display panels have been put into practical use as display devices for text, graphics, and image information, and the display quality has improved.
Developments such as higher resolution are also progressing in various places. A conventional display panel of this type will be explained with reference to FIG. 1, taking a liquid crystal display panel as an example.
), (3) are scanning electrodes (XI, X2, , , ,
, Xrr*-1, Xm), (4) is an image signal shift register, (5) is a line memory, (6) is a line driver, (7) is a scanning signal shift register, (8) is a scanning electrode driver, (9) is a signal input terminal, GO is a signal shift pulse input terminal, and 0]) is a scanning signal shift pulse input terminal.

The operation of the Marx liquid crystal display device having such a configuration will be explained next. The display panel part (1) has a signal electrode (2) (
7) Yl, Y211. , , Yn-1, Yn
On electrodes and scanning electrode (3) Xl, X2, ,
m electrodes of Xm-1, h are arranged in a matrix and a signal is supplied to control the pixel liquid crystal portion corresponding to each intersection of the signal electrode (2) and the scanning electrode (3). . First, the signal (image signal) that controls the amount of transmission of each pixel liquid crystal part of the display panel section (1) is connected to the signal input terminal (
9) is supplied to the image signal shift register (4), and by the clock pulse inputted to the signal shift pulse input terminal 00I, the information is shifted rightward for each pixel to correspond to n signal electrodes (2). Information on the number of pixels is separated. When the shift for one row in the horizontal direction is completed in the image signal shift register (4) in this way, these n stages of image signals are simultaneously transferred to the line memory (5) and temporarily stored. On the other hand, a clock pulse is input to the scanning signal shift register (7) from the scanning signal shift pulse input terminal 01), and the scanning electrodes (3) Xi, X2, , , X
rn-1, generates pulses for line selection of each electrode in sequence from above, and supplies them to a scanning electrode driver (8).

Here, at the same time as one electrode, Xl, of the scanning electrode (3) is selected, a shift pulse signal from the scanning signal shift pulse input terminal αυ is supplied to the line memory (5), and this pulse signal is used as a trigger. Yl, Y2, . . . of the signal electrodes (2) by transferring the image signal from the line memory (5) to the line driver (6).

An image signal (pixel drive signal) is supplied to Yn-1 and Yn, and display for one row of the electrode XI of the scanning electrode (2) is achieved. While this one line of Xl is being displayed, the image signal shift register (4) is supplied with an image signal corresponding to the scanning of the next line, and when the shift of the image signal for - cargo is completed, this signal is sent to the image signal shift register (4). is transferred to the line memory (5). Then, at the same time that X2 of the scanning electrode (2) is selected, the image signal is supplied from the line memory (5) to the line driver (6), and display for the next line of cutting is achieved. . When one screen of image display is completed by sequential scanning from .degree. C. to Xm in this manner, the next image display from Xl is repeated again. In display using this method,
Normally, 60 screens are displayed per second (same as the field frequency of the NTSC television system), but from now on, 60 screens are displayed per second.
The screen will be completed in 15.7m5ec. Further, in FIG. 1, when the number of signal electrodes is n and the number of scanning electrodes is m, first, the shift period (Tx) of the scanning signal shift register (7) is TyL: (16,7/fn) m5ec
Shift period (Ty) of image signal shift register (4)
becomes Ty2(16,7/nXm) m5ec.

By the way, in the display device shown in FIG.
, line memory (5), line driver (6), scanning signal shift register (7), scanning electrode driver (8))
Since the display panel section (1) and the peripheral circuit section require at least m + n wires, this poses an extremely serious problem in mounting. For example, if there are 250 In-N wires, more than 500 wires are required between the panel and the surrounding area.

-1. As a solution to this problem, a display device as shown in FIG. 2 has also been proposed.

The one shown in Fig. 2 is constructed by configuring the peripheral circuitry in Fig. 1 on the display panel 02 to minimize external wiring, and each component is functionally the same as that shown in Fig. 1. Note that α East is the ground or common terminal.

Figure 2 The operation of the display device in Figure 1 is exactly the same as that in Figure 1, but the number of electrodes in the wiring between the liquid crystal display panel and the outside is 1.
The feature is that it can be processed with 4 wires per wire without the need for rows.

However, as explained earlier, the scanning signal shift register (
7) and the shift period of the image signal shift register (4) 1"x, Ty is the number of gold electrodes m-n-250,
Tx257. /asec,”'!:0.27,as
It becomes ec. These shift periods are extremely short for Ty, apart from Tx, and have a high cut-off frequency of 5M.
A device with a frequency of Hz or higher is required. Therefore, in order to realize this with the configuration shown in FIG. 2, a semiconductor process using a single crystal Si semiconductor is required. Such a process has disadvantages in that the cost of the Si wafer is high and it is difficult to obtain a panel that is that large.

On the other hand, there is a method of constructing a thin film transistor (TPT) on a glass substrate or the like by a method such as vapor deposition, and amorphous Si has been attracting attention as a semiconductor thereof. However, the current situation is that the response speed of amorphous Si is one order of magnitude slower than that of single crystal St. Therefore, constructing a display panel such as a liquid crystal using amorphous Si TPT has advantages in terms of cost and size, but there is a problem in performance such as response speed, and this makes it possible to create a display panel like the one shown in Figure 2. It's difficult to do.

OBJECTS OF THE INVENTION An object of the present invention is to provide a display device that can reduce the number of wires between a display panel and the outside by using thin film transistors or the like.

Structure of the Invention In order to achieve this object, the present invention comprises signal electrodes and scanning electrodes arranged in a matrix on a display panel, an image signal shift register for supplying signals to the signal electrodes, a line memory, and a line drive. be at least 2
the image signal processing section, the scanning signal shift register and the scanning electrode driver for supplying signals to the scanning electrode; and the image signal processing section, the scanning signal shift register and the scanning electrode driver are connected to the display panel. A thin film transistor is used in the upper peripheral part, and the image signal and shift pulse to be supplied to the image signal shift register are processed and supplied to an external peripheral circuit outside the display panel, and the image signal is To provide a display device which lightens the load on a circuit by increasing the period of each processing part by providing a plurality of processing parts.

DESCRIPTION OF THE EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 3 and 5. Figure 3 shows the schematic configuration of the display panel of the display device, where 04) is the display panel, αυ is the display section, and O
Q is the signal electrode (Yl, Y2, Y3, Y4, 9.
, , Yn-3, Yn-2, Yn-1, Yn Ten is 4
), the α force is a multiple of the scanning electrodes (XI , X2 , ,
,,.

xm-1,,Xm), (to)? υ■ (A) is the image signal shift register, 0s @ (C) (C) is the line memory,
(A) □□□ (E) (4) is a line driver, (7) is a scanning signal shift register, 0η is a scanning electrode driver, ■
① (g) 弼 is an image signal input terminal, ② (to)) is a signal shift pulse input terminal, (d) is a scanning signal shift pulse input terminal, and button) is a ground or common terminal.

Figure 4 shows the schematic configuration of the peripheral circuits, where (6) is a signal shift pulse downgrader, (to) is an image signal sample, pull-hold circuit, and ←7) h = fi signal shift. Pulse input terminal, 轡 is the original image signal input terminal, ←9) He (
5]) e52) are signal shift pulse output terminals, 'H4' and 'H4' are respectively image signal output terminals, and 'E' is a ground or common terminal.

Next, the operation will be explained. Note that before explaining the overall operation, the functions of the display panel and the external circuit will be explained. Third
The display panel (14) shown in the figure includes four image signal processing sections. That is, image signal shift register 08J1
The image signal processed by the line memory (IO, line driver (a)
The image signal supplied to and processed by the image signal shift register Qυ, line memory @, and line driver @ is of signal type eiii HノX2, Xs, , , , , Xn
-24 supply terminals, image signal shift register (c), line memory (b), and the image signal processed by the line driver are sent to signal electrodes OQ X3, X70. ,0. Xn-
The image signal processed by the image signal shift register (c), line memory (product), and line driver (2) is supplied to X4°Xe, . . . , Xn of the signal electrode α6. Therefore, the period (Ty) of each image signal processing section is allowed to be four times as long.

In the peripheral circuit outside the display panel for driving the display panel shown in FIG. The shift pulse (clock pulse) is counted down to 1/4 and shifted by one period of the original signal shift pulse.
3;) t44) (4ω0Q and also supplied to the signal shift pulse output terminal (to) as a signal shift pulse.These signal shift pulse output terminals Ω
9)■βυ5 are each connected to the signal shift pulse input terminals shown in Fig. 3, and are connected to the image signal shift register (support) C21) C! 41@i (supplies the i shift pulse. On the other hand, to the original image signal input terminal), the original image signal of FIG. 5(f) is supplied, and this original image signal is sent to the sample hold circuit 'li3 − is input. Sample and hold circuit 04) (c) In (c), the signal shift pulse from the step down converter (b) (Fig. 5 (b)
(c) (d) (e) ) positive rising edge fA 782 &? (61), the original image signal is sampled and held, and as shown in FIG. , these image signals are outputted to the image signal output terminals Q (goods) (g) so, respectively.The decompressed image signal output terminals QIIMM are respectively connected to the image signal input terminals 64 and 64 in FIG. Image signal shift register (18) 021>(c)@
The image signal is supplied to the

Next, to explain the overall operation, the image signal shift register (18J'AI) (c) and (b) in Fig. 3 has the following:
The image signal (gl (hl) (il (jl) shown in FIG. 5 is supplied from the image signal output terminal 53 M 53 (to) of the peripheral circuit in FIG. The signal shift pulse output terminal H'l of the peripheral circuit in FIG. 4 is passed through the shift pulse input terminal Cθ (to).
l M 6υ6 from the signal shift pulse shown in Figure 5 (
bl (C) (di (el) is supplied, respectively, and shifts the image signals to the right. However, in this case, each image signal shift register is shifted 74 times, which is the number of electrodes in one horizontal line. - When the horizontal line shift is completed, the image signal is transferred to (E) and (C) of the line memory, respectively, and from the scan signal shift register (7) and the scan electrode dry pari η to the scan electrode α
When one of the drivers is selected and driven (this operation is the same as the conventional method), the image signal of the line memo IJ C1l@Zeng is transferred to the line drivers 4 (C), (E) and 4, respectively, and the signal Image signals are supplied to XI to Xn of electrodes QfG,
- Horizontal line image display is achieved. Then, by repeating these actions one line from top to bottom, 1
It is now up to the image display on the screen to be achieved.

As is clear from the above description of the display panel and peripheral circuits, the original image signal of FIG. F
Since the image signal of FIG. 5 (glfhHil(jl) is obtained by sample-holding with the shift pulse of di (e) and is supplied to the display panel C1 (a) of FIG. 3, the individual image signals of the display panel circle are Shift register o8eυ (c) (a), line memory 09 @ (c) (c), line driver (7) (a) (e) (2) are the conventional image signal shift register (4), line memory ( 5), line driver (6)
), the response speed is four times worse than that of , each period of line memory and line driver Ty = 4><Ty = 1. l %seC
becomes.

Therefore, these circuits can be constructed on a thin film (displayed by a TFT made of amorphous Si).

In addition, the response speed required for the scanning signal shift register (e) and the scanning electrode driver 6υ is that even if the number of scanning electrodes is approximately 250, the period Tx is approximately 67 μsec, and T' F T made of amorphous Si is sufficient. There is plenty of room, and this part is easy to configure on the display panel.

In addition, in the explanation of the above embodiment, four sets of image processing signal units each consisting of an image signal shift register, a line memory, a memory, and a line driver are configured on the display panel, but it is also possible to increase the number of sets beyond this. Yes, and the cycle will be longer. Conversely, it is also possible to reduce the number of sets. However, in this case, performance requirements for semiconductor elements become stricter, and the number of wiring between the display panel and the outside becomes correspondingly smaller.Also, although we have explained using liquid crystal as an example of a display element, other devices such as EL etc. The method of the present invention can be carried out even when the display panel is constructed using display elements of 1 to 1, and there is no difference in effect.

Effects of the Invention According to the display device of the present invention, as is clear from the above description, an image signal processing section consisting of a plurality of sets of image signal shift registers, line memories, and line drivers is configured on the display panel. Therefore, even if the response speed and other performance of these circuits is somewhat poor, it is possible to realize a display device with a reduced number of wiring, and TPT using amorphous Si material in the circuit configuration can be realized.
etc. can be used. This means that single crystal Si
This means that it is possible to make the display panel larger by using a glass substrate, etc., and to create a display device with around 10 fewer wires between the inside and outside of the display panel, which is extremely effective. It's large.

1 and 2 are schematic configuration diagrams of a conventional matrix type display device, FIGS. 3 and 5 show an embodiment of the present invention, and FIG. 3 is a schematic configuration diagram of a display panel. 5 is a schematic configuration diagram of a peripheral circuit, and FIG. 5 is a signal waveform diagram for explaining the operations of FIGS. 3 and 4.

Gf9 is the signal electrode, Q force is the scanning electrode, O sudden (IQ Q4
@ is an image signal shift register, 4 I221□□□ (4
) is the line memory, head ■ (to) @ is the line driver, gloss is the scanning signal shift register, 6 is the fixed electrode dry cap, (6) is the stepper, (g) (goods) (c) 0Q is Sample and hold circuit.

Patent applicant agent Figure 1 9, 2 figures of 4 spears 2 Figure 3 74 Figure 4

Claims (2)

[Claims] (1) At least two or more sets of image signals consisting of signal electrodes and scanning electrodes arranged in a matrix on the display panel, an image signal shift register for supplying the signal electrode number signal, a line memory, and a line trino. The image signal processing section, the scanning signal shift register, and the scanning electrode driver are provided in a peripheral area on the display panel. A display device configured using thin film transistors, and configured such that image signals and shift pulses to be supplied to the image signal shift register are processed and supplied by an external peripheral circuit outside the display panel. . (2) The external peripheral circuit includes a stepper that counts down clock pulses corresponding to the number of signal electrodes on the display panel to generate shift pulses, and a display panel that samples and holds the original image signal using the shift pulse and converts it into an image signal. 2. A display device according to claim 1, comprising a sample and hold circuit for supplying an image signal to an image signal shift register.