JPH0762789B2 - Driver-Built-in active matrix panel - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an active matrix panel with a built-in driver, which is formed by a thin film transistor (hereinafter, abbreviated as TFT).

[Prior art]

Successful trial production of active matrix panels in which a TFT matrix for switching was formed on a transparent substrate by a thin film layer of polycrystalline silicon or amorphous silicon, and LCD TVs using active matrix panels were mass-produced and commercialized. Is being done. Attempts have been made to form a scan line or data line driver on the same transparent substrate on which the above-mentioned switching TFT matrix is formed, and the results have already been announced. (Y.Oana SID84 DIGEST, P.312, S.Morozumi, etal SI
D84 DIGEST, P316) The conventional driver built into the active matrix panel, especially the data line driver, is configured as shown in Fig. 1. The analog switches 106, 107, ... Are connected to the data lines 111, 112 ,. Opening / closing of the analog switch is controlled by the output signals of the shift registers 101, 102, .... In the figure, 121 is a video signal line and 122 is a scanning line. When the data line driver is configured as described above, the shift register must operate at the same frequency as the sampling frequency of the video signal, and high speed is required. However, the on-resistance of TFT is generally high, and high-speed operation like single crystal silicon MOSFET cannot be expected. Therefore, according to the conventional active matrix panel with a built-in driver, the sampling frequency of the video signal is limited due to the characteristics of the TFT, and the high definition is also limited.

〔Purpose〕

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned drawbacks of the prior art and to realize an active matrix panel with a built-in driver, which is capable of sampling a video signal at a high frequency and has a high display quality.

〔Overview〕

The present invention, in an active matrix panel having N data lines, is generated from output signals of a built-in N / K stage shift register and K output signals of a delay circuit connected to each output of the shift register. The data lines are driven by using N sampling pulses.

〔Example〕

 Hereinafter, the present invention will be described in detail based on examples.

FIG. 2 is a block diagram for explaining the gist of the present invention. In the figure, 201, 202 and 203 are shift registers composed of TFTs, 204, 205 and 206 are sampling pulse generation circuits composed of delay circuits and TFT logic circuits, and 207 to 215 are
The analog switch 216 by TFT is a video signal line, and the data line driver is constituted by the above. on the other hand,
Reference numerals 237 to 243 are shift registers forming a scanning line driver. Further, 218 to 226 are data lines, 227 to 233 are gate lines, and 234, 235, 236 and the like are pixels, and the pixel portion 217 is constituted by the above. In the data line driver of FIG. 2, the above-mentioned value of K is K = 3, and three sampling pulses are generated from the shift register of one stage and the integrating circuit connected to the output of the shift register.
The sampling pulse controls the opening and closing of the analog switches 207 to 215.

FIG. 3 shows a specific embodiment of the data line driver of the present invention. In the figure, 301 is a shift register, 302, 303,
304 and 306 are buffers composed of two stages of TFT inverters, 305 and 307 are TFT inverters, 308 and 310 are TFT AND gates, 309 is a NOR gate by TFTs, and 311 to 313 are TFs.
Analog switches by T, 314 to 316 are thin film resistors, 317 to 319 are thin film capacitors, and 320 is a video signal line. FIG. 4 is a diagram for explaining the operation of the embodiment shown in FIG. The transfer data indicated by 401 is output to the output terminal 322 of the shift register 301, and a signal having a waveform equal to 401 indicated by 402 is obtained at 323. Further, as shown by 403, an integrated waveform of the signal 402 is obtained at the output terminal 324 of the integrating circuit including the thin film resistor 314 and the thin film capacitor 317. The waveforms 403 and 40
4,408 appears. Therefore, at the output terminal of the AND gate 308, the sampling pulse having the pulse width T shown at 409 is obtained. On the other hand, similarly, at the node 326, the integrated waveform shown at 405,
Waveform in which waveform 405 is shaped, such as 406, at node 327,
The integrated waveform shown at 407 is generated at the node 328, which results in NOR
The output terminals of the gate 309 and the AND gate 310 are 410 and 410, respectively.
A sampling pulse having a pulse width T shown by 411 is obtained.

The above-mentioned pulse width T is determined in proportion to the time constant of the integrating circuit composed of the thin film resistor and the thin film capacitor.

FIG. 5 shows an example of a sectional structure of the driver integrated circuit shown in FIG. In FIG. 5, 501 is an insulating substrate, 50
2, 503 is a first silicon thin film layer (however, 502 is a portion not doped with impurities, 503 is a portion doped with impurities), 504 is a gate oxide film, 505 is a second silicon thin film layer, 506 Is an interlayer insulating film, and 507 is a transparent conductive film layer. A TFT is formed in 508, a portion 503 forms a source and a drain, and a portion 505 forms a gate. Also, 50
9 has a resistance due to the first silicon thin film layer, 510 has
A capacitor is formed by the second silicon thin film layer, the interlayer insulating film, and the transparent conductive film layer. In addition, the thin film resistor is
The present invention can be realized even if it is replaced with and is configured as a MOS resistor.

〔effect〕

As described in the section of the prior art, a TFT composed of polycrystalline silicon, amorphous silicon, etc. has inferior characteristics to a single crystal silicon FET, and particularly has a high ON resistance. Therefore, the shift register incorporated in the thin film active matrix panel has a limited operating speed. As in the present invention,
By providing a means for driving N data lines by a shift register of N / K stages and an integration circuit and a TFT logic circuit connected to the output of the shift register, the operating speed required for the shift register is conventionally reduced. Can be reduced to 1 / K.

Further, according to the present invention, the number of stages of the shift register is
1 / K is sufficient, and since the integrating circuit and the simple logic circuit as shown in FIG. 3 are used instead, the number of TFTs constituting the driver is reduced as a whole. Therefore, the manufacturing yield is improved and the power consumption of the driver is reduced.

According to the present invention, the function and the manufacturing yield of the driver-equipped active matrix panel are significantly improved as described above.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram for explaining a conventional technique. FIG. 2 is a block diagram of the embodiment of the present invention. FIG. 3 is a diagram showing an embodiment of the present invention. FIG. 4 is a diagram for explaining the operation of the present invention. FIG. 5: is the figure which showed the cross-sectional area structure of the Example of this invention.

Claims (1)

[Claims] 1. N data lines and M scan lines orthogonal to each other, pixel electrodes and thin film transistors arranged at intersections of the data lines and the scan lines, and a data line driver for driving the data lines. In the active matrix panel with a built-in driver, the data line driver includes an N / K stage shift register and an N / K stage shift register.
/ K sampling pulse generating means, each of the sampling pulse generating means generates K sampling pulses with different sampling timings from the shift register output of each stage by an integration circuit of K stages. Active matrix panel with built-in driver.