JPH04330489A - Liquid crystal display device - Google Patents

Abstract

PURPOSE:To reduce the total power consumption and heat generation regarding the transmission of display data when there are the same data present in one picture of display data. CONSTITUTION:For a liquid crystal display based upon data obtained by converting serial data from a display data generation part 10 into parallel data by a serial/parallel converter and passing the data through a frame memory, a display data compressing circuit 11 which compresses the display data from a display data generating circuit is provided between a display data generating circuit 1a and the parallel/serial converter 13 and a display data expanding circuit 22 which expands the compressed display data is provided between a serial/parallel converter 21 and frame memory 2b; and power strobe circuits 12 and 23 are used to supply electric power to the parallel serial converter and serial/parallel converter with the power strobe control signal from the display data compressing circuit in the absence of the display data generated by the display data compression.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a liquid crystal display device used as a variety of displays, and more particularly to a liquid crystal display device equipped with a power strobe circuit that enables serial transmission of digital video data. This invention relates to display devices.

0002

[Prior Art] As shown in FIG. 3 (block diagram showing the configuration of a liquid crystal display device), the conventional technology is to transfer data necessary for display from a display data generating section 1 to a liquid crystal display section 2. A predetermined liquid crystal display is performed on the LCD (liquid crystal panel) 2f. At this time, the display data generation section 1 converts display data (parallel data) generated from a display data generation circuit 1a comprising, for example, a graphic processor into a P/S (parallel/serial converter) 1b. It is configured to convert to serial data and output it. The liquid crystal display section 2 receives serial data from the display data generating section 1 via a high-speed serial transmission line with an S/P (serial/parallel converter) 2a, converts it into parallel data, and then converts the serial data into parallel data. FM (frame memory) 2b→
A driver circuit 2e is driven via an LT (look-up table) 2c and a D/A (digital-to-analog converter) 2d, and the LCD 2f is driven by the driver circuit 2e.

0003

[Problem to be Solved by the Invention] In such conventional technology, since it is necessary to transmit a large amount of display data for one screen through a serial transmission line in a short time of 60 ms, it is extremely difficult to use. This required high-speed serial transmission, which caused problems in terms of heat generation and power consumption.

The present invention has been made in view of the above-mentioned problems of the conventional technology, and its purpose is to prevent the same data from appearing continuously on one screen of display data. The present invention provides a liquid crystal display device that can reduce the total power consumption and heat generation associated with the transmission of display data in some cases. Another object of the present invention is to use the present invention in cases where reduction of heat generation is an important factor, such as when used as a display device that requires high airtightness and sealing performance, such as in aircraft equipment. The object of the present invention is to provide a liquid crystal display device that can achieve sufficient effects by using the same technology.

[0005]

[Means for Solving the Problems] In order to achieve the above object, the present invention converts display data generated from a display data generation circuit into serial data using a parallel/serial converter and outputs the serial data. A liquid crystal display device that performs liquid crystal display based on a display data generation section and the data after converting the serial data from the display data generation section into parallel data using a serial/parallel converter and passing through a frame memory. A display data compression circuit for compressing display data from the display data generation circuit between the display data generation circuit and the parallel/serial converter of the display data generation section. A display data decompression circuit for decompressing compressed display data is provided between the serial/parallel converter of the liquid crystal display section and the frame memory, and the display data compression circuit is provided. Display data generated due to display data compression due to
During the data-free period, the power strobe control signal input from the display data compression circuit is used to power strobe the power supplied to the parallel/serial converter and the serial/parallel converter. It is characterized by the provision of a strobe circuit.

[0006]

[Operation] When the same data is transmitted continuously within one screen worth of data transmitted as display data, the display data
The total number of data can be reduced by compressing data into data and its repetition rate, and the serial driver/receiver can be power-strobed when there is no more data to be transmitted during serial transmission. By reducing (stopping) the power supply, total power consumption (heat generation) is reduced. For this purpose, in the display data generation section, a display data compression circuit is provided in series between the display data generation circuit and the P/S. On the other hand, in a liquid crystal display section corresponding to this, a display data expansion circuit is provided in series between the S/P and FM. Furthermore, there is a time when no serially transmitted data is available due to the "reduction" in the number of data due to display data compression by the display data compression circuit. During this period, a power strobe circuit is further installed in the display data generator and the liquid crystal display to control the P/S and S/P power.
Do down. This reduces total power consumption. At this time, the serial transmission rate is fixed at a rate at which full screen data can be transmitted.

[0007]

[Example] An example will be described with reference to the drawings. In the following drawings, parts that overlap with those in FIG. 3 are given the same numbers and their explanations will be omitted. FIG. 1 is a block system diagram showing a specific embodiment of the liquid crystal display device of the present invention. FIG. 2 is a schematic time chart regarding the power strobe circuit for explaining FIG.

In FIG. 1, reference numeral 10 is a display data generating section. In this display data generation section 10, reference numeral 11 is a display data compression circuit for compressing display data, which is provided in series between the display data generation circuit 1a and the P/S 13. Reference numeral 12 is used to utilize the period in which the display data is compressed by providing the display data compression circuit 11, resulting in a reduction in the number of data and a period in which there is no serially transmitted data. The power strobe control signal is input from the display data compression circuit 11 provided in This is a power strobe circuit. Reference numeral 20 is a liquid crystal display section. In this liquid crystal display section 20, the reference numeral 22 is a display data expansion circuit provided in series between the S/P 21 and the FM 2b, and the reference numeral 23 is a display data expansion circuit having the same configuration as the power strobe circuit 12. BF by inputting the power strobe control signal from the data compression circuit 11
23a→This is a power strobe circuit that power strobes the power supplied to the serial driver of the S/P 21 via the transistor circuit 23b.

[0009] Such a configuration will be explained below using FIG. 2. Display data as shown in FIG. 2(a) is sent from the display data generation circuit 1a (all data is sent out without any gaps.
(the interval between the frame data is always constant) is led to the display data compression circuit 11. In the display data generation circuit 11, among the data for one screen transmitted as display data, the same data (“C” for frame 1 data) is continuously transmitted. When transmitted continuously, compressed data is generated by reducing the total number of data by compressing the display data and repetition number data into two words ( See FIG. 2(b). In the figure, n and m in the compressed data of the frame represent the number of repetitions of the same data).

Therefore, in the compressed data that has passed through the display data generation circuit 11, there is a time period in which no data is present between the compressed data and the next frame of data. In other words, if the serial data transmission rate is set to a rate that allows all display data to be transmitted, the transmission data will naturally be compressed and the time will be reduced by the time the data is reduced. There will be no such thing. And during this time when there is no data to be transmitted during serial transmission,
A power strobe control signal is applied from display data compression circuit 11 to power strobe circuits 12 and 23. Therefore, in the power strobe circuits 12 and 23, when receiving the power strobe control signal, the signal is transferred to the BF.
By turning off the transistor circuits on the power supply line through the power supply, the power supply to the P/S 13 and S/P 21 is power-strobed. As a result, the relevant P/S13, S/P
In other words, reduce power consumption of 21 and suppress heat generation.
Power strobe the serial driver/receiver to reduce the power supply when no data is available (Figure 2 (C)
) Power strobe control signal serial transmission driver,
The total power consumption (heat generation) can be reduced during the receiver power-down period (see D). However, with such a configuration, if data is compressed over the entire screen with little compression effect, no reduction in power consumption or heat generation can be expected.

Note that the present invention is not limited to the above-described configuration; for example, the power strobe circuit is provided separately in the display data generation section and the liquid crystal display section; It goes without saying that it may be provided, or it may be provided in either one (for example, within the display data generation section). In short, in order to make effective use of the period in which no display data occurs due to display data compression caused by providing a display data compression circuit, P/S and S Power the power supplied to /P.
It suffices if the configuration is such that it strobes.

0012

[Effects of the Invention] Since the present invention is constructed as described above, it produces the following effects. (b) During the period when there is no serial transmission data, P/S, S/
Since power supply to P is stopped, total power consumption and heat generation can be reduced. This means that sufficient practical effects cannot be obtained especially when used in display devices that require high airtightness and sealing properties, and where reduction of heat generation is an important element. can. (b) When the display contents are displayed on a black or white background, a considerable data compression effect can be expected, and accordingly, a significant reduction in power consumption and heat generation can be expected.

[Brief explanation of drawings]

FIG. 1 is a block system diagram showing a specific embodiment of a liquid crystal display device of the present invention.

FIG. 2 is a schematic time chart regarding a power strobe circuit for explaining FIG. 1;

FIG. 3 is a block diagram showing the configuration of a liquid crystal display device.

[Explanation of symbols]

1, 10 Display data generation section 11 Display data compression circuit 1a Display data generation circuit 12, 23 Power strobe circuit 2, 20 Liquid crystal display section

Claims (1)

[Claims] [Claim 1] A display data generation section that converts display data generated from a display data generation circuit into serial data using a parallel/serial converter and outputs the serial data; In a liquid crystal display device that performs liquid crystal display based on the data after serial data is converted into parallel data by a serial/parallel converter and passed through a frame memory, the display data generation section of the display data generation section A display data compression circuit for compressing display data from the display data generation circuit is provided between the circuit and the parallel/serial converter,
A display data decompression circuit for decompressing compressed display data is provided between the serial/parallel converter of the liquid crystal display section and the frame memory, and the display data compression circuit is provided. A power strobe control signal inputted from the display data compression circuit is supplied to the parallel/serial converter and the serial/parallel converter during a period in which there is no display data caused by display data compression. A liquid crystal display device characterized by being equipped with a power strobe circuit that strobes a power source.