JPH08179265A - Liquid crystal display device and interface method therefor - Google Patents

Abstract

PURPOSE: To increase resolution and display colors without increasing signal lines by transmitting display data while encoding the data with a prescribed algorithm and reducing transferred data amount while decoding the encoded data. CONSTITUTION: This device is constituted of a decoding device 15, a liquid crystal display panel 11, a scanning electrode driving device 12 and a signal electrode driving device 13. An interface of the display data is constituted of an encoding device and the decoding device 15 of a liquid crystal display device 10. In this case, the correlation value of the display data, for example, the continuity of the same data in the horizontal and vertical directions is checked in the encoding device 30, which performs the time compression of the display data without losing the display data and generates a compressed data signal 32 and a compression control signal 31. On the other hand, in the liquid crystal display device 10, the decoding device 15 reproduces the display data and also adds synchronizing signals by the compression control signal 31 and the compressed data signal 32 from the encoding device 30 to control the scanning electrode driving device 12 and the signal electrode driving device 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dot matrix type liquid crystal display device.

[0002]

2. Description of the Related Art In recent years, a dot matrix type display device such as a liquid crystal display device has been applied to a display device such as a portable computer due to its features of thinness and power saving. Due to the improvement of the processing performance of computers and the spread of graphic user interfaces, the display device is required to increase the amount of display information (resolution and display color).

FIG. 3 is a block diagram of a conventional liquid crystal display device. In FIG. 3, reference numeral 10 denotes a liquid crystal display device, which includes a liquid crystal display panel 11, a scanning electrode driving device 12, and a signal electrode driving device 13. Scan electrode driving device 12
Thus, the scanning electrodes of the liquid crystal display panel are sequentially selected, and the display data corresponding to the selected scanning electrodes is applied from the signal electrode driving device 13. A display controller 20 supplies display data and synchronization signals to the liquid crystal display device 10 to the scan electrode driving device 12 and the signal electrode driving device 13. Here, the specification of the display data signal supplied from the display controller 20 to the liquid crystal display device 10 is generally expressed by the following equation. fsclk = fv × N × M p = log2G where fsclk: sampling clock frequency fv: driving frame frequency N: vertical line number M: horizontal line number p: data width G: display gradation number / pixel For example, 640 (H) * 480 When displaying a liquid crystal panel with (V) dots at a frame frequency of 60 Hz and 256 gradations fsclk = 18.43 MHz p = 8

[0004]

However, in the above configuration, in order to increase the display capacity, it is necessary to improve the data transfer rate of the signal electrode driving device 12 and the display controller 20, but a semiconductor process or the like. It is not easy due to the restrictions of. Therefore, set the amount of data transfer per clock to 2 dots or 4 dots,
It was necessary to devise the circuit configuration of the signal electrode driving device 12 or divide the signal electrode driving device 12 into two blocks as shown in FIG. 4 and operate them simultaneously. Therefore, there is a problem that the number of signal lines is increased and the cost of cables, connectors, etc. is increased.

In view of the above points, the present invention has been made possible without increasing the data transfer rate from the display controller.
An object is to provide a liquid crystal display device having a small number of signal lines.

[0006]

In order to achieve the above object, the present invention encodes display data by a predetermined algorithm and sends it out from a display controller, and the liquid crystal display device decodes the encoded data. By converting
To reduce the amount of transfer data.

[0007]

According to the present invention, since the amount of data transferred between the display controller and the liquid crystal display device can be reduced by the above-mentioned structure, the resolution and the display color can be increased without increasing the number of signal lines.

[0008]

FIG. 1 shows the structure of a liquid crystal display device according to an embodiment of the present invention. In FIG. 1, reference numeral 10 denotes a liquid crystal display device, which includes a decoding device 15, a liquid crystal display panel 11,
It is composed of a scanning electrode driving device 12 and a signal electrode driving device 13. The encoding device 30 and the decoding device 15 of the liquid crystal display device 10 constitute an interface for display data.

First, the encoder 30 of FIG. 1 checks the correlation of display data, for example, the continuity of the same data in the horizontal and vertical directions, and time-compresses the display data without any loss. The signal 31 is generated. on the other hand,
In the liquid crystal display device 10, the decoding device 15 reproduces the display data by the compression control signal 31 and the compression data signal 32 from the encoding device and adds the synchronization signal to the scan electrode driving device 12 and the signal electrode driving device. Control 32.

In the display for computer use, since there are many areas of the same brightness and repeated areas of the same pattern, it is possible to sufficiently compress the data. Can be significantly reduced. Especially in color panels and high-definition panels, the effect is great.

FIG. 2 shows the structure of a liquid crystal display device according to another embodiment of the present invention. In FIG. 2, reference numeral 10 denotes a liquid crystal display device, which includes a liquid crystal display panel 11, a scanning electrode driving device 12, and a signal electrode driving device 1 having a decoding function.
It is composed of 4.

First, the encoder 30 of FIG. 2 checks the correlation of display data, for example, the continuity of the same data in the horizontal and vertical directions, and time-compresses the display data without any loss. The signal 31 is generated. on the other hand,
In the liquid crystal display device 10, the signal electrode driving device 14 reproduces display data by the compression control signal 31 and the compressed data signal 32 from the encoding device, and drives the signal electrode of the liquid crystal display panel 11.

By providing the signal electrode driving device 14 with a decoding function, it is possible to reduce the number of input terminals of the signal electrode driving device 14, and it is possible to reduce the size and cost of the package and the peripheral printed circuit board. Reduction is possible. Especially in color panels and high-definition panels, the effect is great.

Although the coding is lossless time compression in the above embodiment, it is not limited to this.
Depending on the configuration of the liquid crystal display device and the contents of the display data, it is possible to allow some loss and further improve the compression effect.

[0015]

As described above, according to the present invention,
By equipping the signal electrode driving device or the liquid crystal display device with the decoding device and inputting the encoded display data from the display controller, the amount of transfer data between the display controller and the liquid crystal display device can be reduced, so that the number of signal lines can be reduced. It is possible to increase the resolution and the display color without increasing the number. Therefore, it is possible to reduce the cost of the connector, the cable, etc. and the EMI (electromagnetic interference), and the practical effect thereof is great.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a liquid crystal display device according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of a liquid crystal display device according to an embodiment of the present invention.

FIG. 3 is a configuration diagram of a liquid crystal display device in a conventional example.

FIG. 4 is a configuration diagram of a liquid crystal display device in a conventional example.

[Explanation of symbols]

 10 liquid crystal display device 11 liquid crystal display panel 12 scanning electrode drive device 13 signal electrode drive device 14 signal electrode drive device with decoding function 15 decoding device 20 display controller 30 encoding device 31 compression control signal 32 compressed data signal

Claims (5)

[Claims] 1. An interface method for a liquid crystal display device, wherein display data is transferred digitally by means of data encoding by a predetermined algorithm and means of decoding the encoded data. 2. An interface method for a liquid crystal display device according to claim 1, wherein compression / decompression without loss is performed on the same continuous data in the vertical or horizontal direction. 3. The liquid crystal display device according to claim 2, wherein the data width is halved or ⅓ by time-division of encoded data. 4. A liquid crystal display device comprising a device for decoding display data encoded by a predetermined algorithm. 5. The liquid crystal display device according to claim 4, wherein the decoding device and the liquid crystal driving device are integrated.