JPS62294223A - Liquid crystal display control system - Google Patents

Abstract

PURPOSE:To extend the life of back illumination and to reduce the power consumption by optionally controlling the back illumination of a liquid crystal display part in accordance with turning-on/off of the output signal of a time monitor part. CONSTITUTION:The controller of a liquid crystal display device with back illumination is provided with a time monitor part 3 which monitors the access signal to a display video memory 1, a mechanism which initializes the monitor part 3 from the external, and an output inhibiting gate 4 which suppresses the output signal of the monitor part 3. The power source of a back illumination part 6 is turned on/off by the output signal of the monitor part 3 to automatically extinguish the back illumination unless it is necessary, and thus, the life of lighting of the back illumination is extended and the power consumption is reduced.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention [Summary] A control device for a backlit liquid crystal display includes a time monitoring unit that monitors an access signal to a display video memory, and an external input to the time monitoring unit. By providing an initialization mechanism and a control mechanism that suppresses the output signal of the time monitoring section, the back illumination of the back-illuminated liquid crystal display section can be arbitrarily controlled by turning the output signal of the time monitoring section on and off. It was designed to control the

[Field of Industrial Application] The present invention relates to a relatively small-scale computer system such as a personal computer, and particularly to a control method for a backlit liquid crystal display of the computer system.

Conventionally, liquid crystal display devices used in relatively small computer systems such as personal computers have a small size (
For example, one (640 x 200 dots) was put into practical use.

Recently, large-sized ones (for example, 640 x 400
dots) have been put into practical use and are now being used as a display device to replace cathode ray tube (CRT) display devices.

Since small-sized devices are usually used in a horizontal position, they are easily exposed to light from ceiling lights, etc., and even reflective LCD devices
The environmental conditions were relatively easy to see.

However, as larger display devices become available, they must be used vertically, creating an environment that is difficult to view for reflective liquid crystal display devices. There is also a demand for use in dark rooms, etc., and it is required to be able to be used in places with relatively little light.

On the other hand, with the advancement of electroluminescence (EL) technology, highly efficient electroluminescence (EL) has been put into practical use.
There is a so-called back-lit liquid crystal display device as a liquid crystal display device that uses a transmission type liquid crystal and can be used in a place with a small amount of light.

In such a liquid crystal display device with back illumination using electroluminescence (EL), there is a problem of the life span of the back illuminator, and an effective display control method is required.

[Prior Art and Problems to be Solved by the Invention] FIG. 2 is a diagram showing an example of the configuration of a conventional back-illuminated display device.

Conventionally, back lighting of display devices with back lighting was turned on/smoke removed! 1) Since the back lighting section 6 was not often controlled and replaced when its lifespan reached the end of its life, there were problems in that it was not only uneconomical but also difficult to operate.

Furthermore, when controlling the lighting/extinguishing of the backlight, it is performed by monitoring key signals from the keyboard (KB) device 8, for example.

In this case, when the display device shown in this figure is used as a monitor in a data processing system, the keys from the keyboard (KB) W8 are not pressed much, so the display device is not in use. There was a problem with the backlight turning off.

In addition, when electroluminescence (EL) or the like is used for such back lighting, a commercial AC power supply is often used without a fan as the power source for lighting, which can lead to the problem of overheating. was there.

SUMMARY OF THE INVENTION In view of the above-mentioned conventional drawbacks, it is an object of the present invention to provide a display control method that extends the lighting life of backlighting and reduces power consumption.

[Means for solving problems]

FIG. 1 is a diagram showing an example of the configuration of a display control method according to the present invention.

In the present invention, (1) a control method for a backlit liquid crystal display, in which a time monitoring unit 3 for monitoring access to the display video memory 1 is provided for a certain period of time;
If there is no access to , the control signal outputted from the time monitoring section 3 controls the backlighting power source of the backlighting section 6 and performs a control to erase the backlighting of the liquid crystal display section 5 . Configure.

Even when the backlight is turned off, the above video memory 1
When there is access to, the backlight is configured to turn on.

(3) The time monitoring unit 3 is configured to receive a tree conversion signal from the outside.

(4) A circuit 4 for inhibiting the output of the time monitoring section 3 is provided.

[Effect]

That is, according to the present invention, in a control device for a backlit liquid crystal display, a time monitoring section that monitors an access signal to a display video memory, an external initialization mechanism for the time monitoring section, and a time monitoring section are provided. By providing a control mechanism for suppressing the output signal of the time monitoring section, the back illumination of the back-illuminated liquid crystal display section can be arbitrarily controlled by turning the output signal of the time monitoring section on and off. Therefore, the lighting life of the backlight can be extended, and the power consumption in the backlight can be suppressed.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

The above-mentioned FIG. 1 is a diagram showing an example of the configuration of the display control method of the present invention, in which the time monitoring section 3. The input signal (video memory access signal, external signal) and the output inhibit gate 4 are necessary means to implement the present invention. Note that the same reference numerals indicate the same objects throughout the figures.

First, video information (not shown) such as characters and graphs to be displayed on the display device sent from the outside (for example, an image processing device) is transferred to the video memory 1 by a video memory access signal sent at the same time. The video memory control section 2 sends the data to the liquid crystal display section 5 for display.

At this time, since this display device is a liquid crystal display device with back lighting, the displayed characters, graphs, etc. are displayed on the back lighting section 6.
It can be seen by the illumination light from.

The time monitoring section 3 is constituted by a counter, which is counted and amplified at regular time intervals, and when a certain time period is counted, it outputs an overflow signal and turns on the output signal of the time monitoring section 3.

As shown in the figure, this counter is initialized every time the video memory access signal or an external initialization signal is input, and functions to repeat the counting again.

Furthermore, even when the output signal is on, that is, the counter is overflowing, if the video memory access signal or external initialization signal is input,
The output signal is turned off and the count is started from the initial state.

When the output signal of the time monitoring section 3 becomes, for example, in the "on" state, it controls the backlighting control section 7 and functions to turn off the power to the backlighting section 6, so that the video is not displayed for more than the above-mentioned certain period of time. If there is no memory access signal or initialization signal from the outside, the output signal of the time monitoring section will turn on due to the overflow signal of the counter.
The power to the back illumination section 6 is turned off, and the back illumination of the liquid crystal display section 5 functions to be turned off.

Next, the output signal of the time monitoring section 3 is input to the prohibition gate 4, and the prohibition gate receives an external prohibition signal, and when the prohibition signal is turned on, the time monitoring section 3 outputs The gate output signal is “on” even if the signal is “on”.
Then, the backlight control section 7 is set to a mode in which backlighting is performed at all times. When the prohibition signal is "OFF", the output of the time monitoring section is gated, and the back lighting section 6 is controlled by the output signal of the time monitoring section.

Based on the output signal of the prohibition gate 4, the backlight control unit 7 turns off the power to the backlight unit 6 and turns off the backlight when the signal is ``on''.
When the output signal is off, the power to the backlight section 6 is turned on to turn on the backlight.

As described above, the present invention provides a time monitoring section that is initialized by a video memory access signal or an external signal, counts a certain period of time, and turns on its output signal when an overflow occurs. The feature is that the power to the backlighting section of a liquid crystal display device with backlighting is turned on and off based on the output signal of the backlighting section, and the backlighting is automatically turned off when it is not necessary. .

Note that, although the external device in the above embodiment is, for example, an image processing device, it goes without saying that the external device is not limited to this.

〔Effect of the invention〕

As described above in detail, the liquid crystal display control method of the present invention is provided in a control device for a backlit liquid crystal display, which includes a time monitoring unit that monitors an access signal to a display video memory, and an external connection to the time monitoring unit. initialization mechanism,
By providing a 28m system for suppressing the output signal of the time monitoring section, the backlighting of the backlit liquid crystal display section can be arbitrarily turned on or off by turning the output signal of the time monitoring section on or off. Since it is controlled, it not only extends the lighting life of the back lighting section but also has the effect of suppressing power consumption in the back lighting section.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an example of the configuration of a display control method according to the present invention. FIG. 2 is a diagram showing an example of the configuration of a conventional backlit display device. It is. In the drawings, 1 is a video memory, and 2 is a video memory control unit. 3 is the time monitoring department, 4 is the prohibition gate. 5 is a liquid crystal display section, and 6 is a back lighting section. 7 is a back lighting control unit, and 8 is a keyboard (KB) device. are shown respectively. [Tsumemitsu] Monument example of the cape method on the left, Shokekuchifu 1
1st territory 1st territory 1st end of the blue vassal)
KO λ Indication 1 2 Yo 2 [F]

Claims (4)

[Claims] (1) A control method for a backlit liquid crystal display, in which a time monitoring unit (3) is provided to monitor access to the display video memory (1), and access to the display video memory (1) is restricted for a certain period of time. If not, the control signal output from the time monitoring section (3) controls the back lighting power source of the back lighting section (6), and performs control to erase the back lighting of the liquid crystal display section (5). LCD display control method. (2) The time monitoring unit (3) is initialized for each access signal to the video memory (1), and even when the backlight is off, the time monitoring unit (3) is initialized when the video memory (1) is accessed. 2. The liquid crystal display control method according to claim 1, wherein the backlight is controlled to be turned on. (3) The liquid crystal display control method according to claim 1, characterized in that an initialization signal for the time monitoring section (3) is externally applied. (4) Claim 1 characterized in that a gate circuit (4) for inhibiting the output of the time monitoring section (3) is provided.
Liquid crystal display control method described in section.