JPS59160187A - Liquid crystal 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] [Technical Field] The present invention relates to liquid crystal display technology, and for example, to a technology that is particularly effective as a display device for displaying display signals formed by a microprocessor. .

[Background technology]

Conventionally, liquid crystal display devices with a dot matrix configuration have been
For example, "Electronic Materials 1 Magazine, October 1980 issue, page 1, 21
~ page 43, is publicly known.

In a display device using a conventional liquid crystal display panel with a dot matrix configuration, pixel data is formed using a microprocessor, written into a RAM (random access memory), and read out to drive signal electrodes. It is something.

Therefore, in the microphone and processor, when displaying alphabento characters and numbers, the encoded information must be converted into display data corresponding to the tonma matrix, and the information must be processed such as being transferred to the RAM. The disadvantage is that there are many.

[Purpose of the invention]

An object of the present invention is to provide a liquid crystal display device with simplified display control.

The above and other objects and novel features of this invention include:
It will become clear from the description of this specification and the accompanying drawings.

A brief overview of typical inventions disclosed in this application is as follows.

In other words, by incorporating a pixel generation circuit into the signal electrode drive circuit of a liquid crystal display panel with a don't-matrix configuration, display can be performed in accordance with coded display information, thereby simplifying display control. It is something to do.

Hereinafter, this invention will be explained in detail together with examples.

〔Example〕

A block diagram of an embodiment of the invention is shown in the drawings.

In the figure, the liquid crystal display panel LCD has scanning electrodes running in the horizontal direction and signal electrodes running in the vertical direction, and display dots are formed at the intersections of the two, and a predetermined display is performed depending on the brightness and darkness of the dots. be exposed. Since such a dot matrix liquid crystal display panel LCD is well known, a detailed explanation of its structure and operating principle will be omitted.

A selection drive signal is sequentially supplied to the scan electrodes of the liquid crystal display panel and the CD by a scan electrode drive circuit R-DRV. This scan electrode drive circuit R-DRV may be a one-chip monolithic semiconductor integrated circuit device T, although it is not particularly limited.
It is composed of CI and forms a multi-value pulse drive signal for AC driving the liquid crystal. For example, such a scanning electrode drive circuit R-DRV can use a semiconductor integrated circuit device such as the product name 'HD44103J sold by Hitachi, Ltd.

In this embodiment, the signal electrodes of the liquid crystal display panel LCD are supplied with display signals formed by a signal electrode driving circuit IC2 constructed from a one-chip monolithic semiconductor integrated circuit device. The signal electrode drive circuit IC2 of this embodiment includes, but is not particularly limited to, a signal electrode drive circuit C-DRV and a ROM constituting a pixel generation circuit.
(read-only memory) and RAM (as refresh memory) for holding coded display data.

The pixel generation circuit is a so-called character generator that receives an 8-bit ASCII code and converts it into character and numeric pixel data composed of 5×7 dots, although it is not particularly limited. Although not particularly limited,
The ROM is configured by a mask type ROM.

Although not particularly limited, the RAM has a storage capacity for storing a code signal corresponding to the number of characters displayed on the liquid crystal display panel, and its address corresponds to a character address displayed on the liquid crystal display panel.

Although not particularly limited, the timing generation circuit TG is based on a reference frequency pulse formed by a crystal oscillation circuit or the like.
A scan timing signal for the scan electrode and a selection timing signal for the signal electrode are formed in relation to each other, and the scan electrode drive circuit R-DRV and the signal electrode drive circuit I
Send to C2.

The drive surface for the signal electrode v! ! A character code to be displayed is written into the RAM of the rIC2 from the microprocessor MPU or a keyboard (not shown).

The display operation is performed as follows. Although not particularly limited, the RAM reads out the code signal and sends it to the ROM in synchronization with the display timing of one character in the horizontal direction. The ROM uses this code signal and
Upon receiving the scan timing signal, pixel data at one character display timing (5 dots) corresponding to the scan electrode is sent out to the signal electrode and drive circuit C-DRV. The signal electrode drive circuit C-DRV forms a multivalued pulse according to the above pixel data to drive the signal electrode. By repeating the same operation as above each time the display timing and scanning timing change, the character information stored in the RAM is displayed as a bright dot on the liquid crystal display panel.
It will be displayed as dark.

〔effect〕

(1) In this embodiment, by incorporating the pixel generator circuit into the signal electrode driving circuit, the display can be performed simply by inputting a character code etc. from a microprocessor, etc. This has the effect of simplifying control. That is, the microprocessor sensor MPU
For example, you only need to transfer data for one instruction per character,
Moreover, it is time to change the display contents and perform a nodek transfer.

(2) Pixel data consisting of a large number of dots is formed in a ROM with a high collection rate, and the RA is used as a refresh memory.
Since M stores coded display data of a small number of bits, when both are built into the signal electrode drive circuit as in this embodiment, the chip size can be reduced. play.

(3) Since the above fil~(2) simplifies the control and simplifies the sliding, there is a synergistic effect that improves the substantial functions of the information processing system using the liquid crystal display device of this embodiment. Effects can be obtained.

Although the invention made by the present inventor has been specifically explained above based on Examples, it goes without saying that this invention is not limited to the above Examples and can be modified in various ways without departing from the gist thereof. Nor. For example, the RAM serving as the refresh memory may be provided as an external circuit of the signal-electrode driving circuit. In addition, in order to add the function of displaying arbitrary characters or symbols, R
Alternatively, the signal may be selectively sent directly to the signal electrode drive circuits C and -DRV without passing through the signal electrode drive circuit C and -DRV.

[Application field]

In the above explanation, the invention made by the present inventor was mainly explained in the case where it was applied to a liquid crystal display device using a microprocessor, which is the field of application that formed the background of the invention, but it is not limited to this. It is applicable to at least a display device using a liquid crystal display panel having a dot matrix structure.

[Brief explanation of the drawing]

The drawing is a block diagram showing an embodiment of the present invention. LCD...Liquid crystal display panel, R-DRV...Scanning electrode drive circuit, IC2...Signal electrode drive circuit, C-DRV...
・Signal electrode drive circuit, ROM...Read-only memory, RAM...Random access memory, TG...
・Timing generation circuit /'-/PU

Claims (1)

[Claims] 1. A liquid crystal display panel having a dot matrix configuration consisting of a scanning electrode and a signal electrode, a scanning electrode drive circuit that supplies a constant scanning pulse to the scanning electrode, and a liquid crystal display panel comprising a scanning electrode and a signal electrode. The signal electrode driving circuit supplies a driving signal in accordance with the information to be displayed, and the signal electrode driving circuit has a built-in cross-bank generation circuit that receives coated display information and converts it into pixel data. A liquid crystal display device characterized by: 2. Claims characterized in that the signal electrode driving circuit is constituted by a 1-chip semiconductor integrated circuit, and the pixel data generation circuit is constituted by a mask type ROM. The liquid crystal display device according to item 1.