JPS6255697A - Liquid crystal display unit - 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 Application of the Invention] The present invention relates to a liquid crystal display device, particularly a large screen (large capacity) display device.
The present invention relates to a liquid crystal drive circuit suitable for display.

[Background of the invention]

In general, large-sized liquid crystal display systems differ between the 1-bit serial transfer method and the n-bit parallel transfer method due to the difference in data input method ("Nikkei Electronics J.
(August 18, 1980 issue), the latter is better in simplifying the system, but the former is more abundant in terms of widespread use of controllers. In recent years, there has been a shift towards the latter. Furthermore, as the system becomes larger, the data transfer speed becomes limited.
Even if a bit parallel transfer method is adopted, there is a problem in that the liquid crystal driver cannot be used within the speed specifications.

FIG. 2 is a block diagram for explaining a conventional liquid crystal display device. In the same figure, when a 400 x 600 dot liquid crystal panel 1t is driven, an upper drive circuit 1h and a lower drive circuit 2b of the signal electrode side drive circuit 2 are constituted by a 4-bit system liquid crystal drive driver 2, and are driven. Data transfer speed of driver 4 (standard 3 MB2
), the screen of the liquid crystal panel 1 had to be divided into two parts, an upper part 1a and a lower part 1b. Therefore, the upper drive circuit 2a and the lower drive circuit 2 on the signal electrode side
The number of drivers 4 configuring b will increase ◇In addition, Do=D3+D4~D? is 4-bit input data, and FLM is a frame frequency signal. In addition, 3
is a scanning side drive circuit consisting of an IC drive circuit 14 connected to the scanning line 12.

[Purpose of the invention]

Therefore, the present invention has been made in view of the above-mentioned problem, and its purpose is to provide 2n-bit parallel transfer that enables large-screen display without being constrained by data transfer speed limitations. An object of the present invention is to provide a liquid crystal display device of the type.

[Summary of the invention]

In order to achieve such an object, the present invention forms a plurality of groups by grouping approximately the same number of adjacent signal electrodes, and the signal electrode terminals drawn out from the signal electrodes of different adjacent groups are connected to each other on a liquid crystal panel. Each group is alternately drawn out to two different sides of the liquid crystal panel so that they are not adjacent to each other on the same side, and the signal electrodes drawn out on the same side of the liquid crystal panel are driven by the same n-bit system driver to achieve 2n-bit parallel input. It is possible.

[Embodiments of the invention]

Next, embodiments of the present invention will be described in detail using the drawings. In FIG. 1, the same or corresponding parts as in FIG. 2 are given the same numbers. In FIG. 1, signal electrode terminals 11a, 11 from the signal electrode 10 of the liquid crystal panel 1 are shown.
Four pieces b are alternately drawn out to the upper and lower sides of the liquid crystal panel 1.

Upper drive circuit 2a receives 4-bit input data Do%D3 and 4-bit input data D4-D? Each of the lower drive circuits 2b, which inputs
The other side is connected to the signal electrode terminal 11b. There are 320 signal electrode terminals (11m).

There are 320 signal electrode terminals 11b, 640 in total.

In such a configuration, to display one screen,
When driving with the frame frequency set to 70Hz,
Data transfer speed CP is: cp = 400 (number of signal electrodes) x 70 (frame 47 seconds) = 2.24MH
z, and the upper limit of the driver speed can be set within 3 MHz.

According to such a configuration, the number of data in the upper drive circuit 2a and the lower drive circuit 2b can be halved, so there is no need to divide the liquid crystal panel 1 into two in terms of data transfer speed. Therefore, the number of drivers 4 can be reduced to about half.

〔Effect of the invention〕

As explained above, according to the present invention, the number of drivers in the signal side drive circuit can be reduced, so the number of components mounted on a printed circuit board can also be reduced, resulting in extremely excellent effects such as lower costs. can get.

[Brief explanation of the drawing]

FIG. 1 is a block diagram for explaining an embodiment of a liquid crystal display device according to the present invention, and FIG. 2 is a block diagram showing a conventional liquid crystal display device. 1...Liquid crystal panel, 1a...upper part, 1b...
・Lower, 2...Signal electrode side drive circuit, 2a...
Upper gJX7#J circuit, 2b...lower drive circuit, 3...scan 1lIl drive circuit, 4...drive driver, 10...signal electrode, lla, llb...
・Signal electrode terminal. Figure 1') L-1 Figure 2 4 Sky

Claims (1)

[Claims] In a liquid crystal display device equipped with a signal electrode side drive circuit and a scanning side drive circuit that output drive signals to the signal electrodes and scanning electrodes of a liquid crystal panel in which liquid crystal pixels are arranged in a matrix, signals extracted from the signal electrodes of the liquid crystal panel. The n electrode terminals are arranged alternately on two different edges of the liquid crystal panel, and the signal electrodes connected to the signal electrode terminals arranged on the same side are driven by the same n-bit drive driver system, and 2n-bit parallel data is generated. A liquid crystal display device characterized by being used as an input system.