JPH10312174A - Lcd back light control system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce power consumption in a display having resolution lower than the maximum displayable resolution of an LCD panel by performing the control of the back light of an area except an effective display area being the area of low resolution being in the area of the maximum displayable resolution in a software manner at the time of performing a display on the LCD panel with resolution lower than the maximum displayable resolution of the LCD. SOLUTION: Controls of the lighting area and the putting off light area of the back light are performed together with the control of the display of the LCD by magaging n[0], [0], n[1], [0],...n[x], [y] which are divided in a several dot unit by softwares by using the LCD panel in which the back light can be controlled in the several dot unit. Now, the controls are performed by resolution information and the maximum display resolution information of the LCD. These control perform controls by building codes in softwares (a driver, a BIOS, an AS or the like) operating by being annexed to a display starting instruction and a resolution changeover.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an LCD backlight control system, and more particularly, to an LCD for reducing power consumption of a television, a computer device, etc. having an LCD panel.
The present invention relates to a D backlight control method.

[0002]

2. Description of the Related Art As a conventional example, Japanese Patent Application No. 4-34591 discloses a system in which a drive for a CRT display device and a drive for an LCD display device are used in common. In the LCD display control system for controlling the display drive, the CRT
A circuit that generates a timing signal for driving the LCD by using a signal indicating an effective display period set according to a back porch following the vertical synchronization signal output from the controller, and controls the LCD by the timing signal generated by the circuit. It is disclosed that display drive control is performed.

[0003] When the display resolution is lower than the physical resolution of the LCD panel, the display resolution is recognized from the polarities of the vertical synchronizing signal and the horizontal synchronizing signal, and a display timing signal according to the display resolution is generated. It is disclosed that the driving of the electrodes of the LCD panel is controlled. .

Further, the vertical resolution of the screen to be displayed is L
Means for determining an effective display area when the resolution is lower than the physical vertical resolution of the CD panel; and means for generating a plurality of line scan signals in a period corresponding to one line scan of the effective display area for an area other than the effective display area. It is disclosed that the electrodes of the LCD panel are driven and controlled by the line scanning signal obtained by the means. However, in the above conventional example, the display drive timing of the CRT display is mainly used.
In particular, there is no description regarding the backlight.

Conventionally, in controlling the LCD panel, when displaying a displayable resolution on the LCD panel,
If it is lower than the maximum displayable resolution of the LCD panel (for example, 640 × 4 dots for an LCD panel with 800 × 600 dots as the maximum displayable resolution)
80 dots, 512 x 384 dots, 400 x 300 dots, 320 x 240 dots, 320 x 200 dots, etc.), the backlight is applied to the entire LCD panel (maximum displayable resolution area). Lighting requires a lot of power.

The above-mentioned prior art will be described with reference to FIG. FIG. 4A shows an example in which the maximum displayable resolution of the LCD panel is set to 800 × 600 dots, and FIG. In this way, the display is performed at a resolution of 640 × 480 dots within the display of 800 × 600 dots.
When FIG. 4B is displayed, 640 × in FIG.
The backlight is turned on also for the area other than the 480 dot display (invalid display area).

[0007]

As described above, since the backlight is turned on even for the invalid display area,
The power consumption in displaying a resolution lower than the maximum displayable resolution of the LCD panel is large, and wasteful power consumption is required.

Accordingly, an object of the present invention is to reduce power consumption in displaying a resolution lower than the maximum displayable resolution of an LCD panel.

[0009]

In order to reduce the power consumption of this system, when displaying a resolution lower than the maximum displayable resolution of the LCD panel, the backlight for the invalid display area is turned off. Specifically, the LCD panel has a means for judging and controlling an invalid display area portion at the time of a display start command, for controlling the backlight of the LCD panel in units of several dots.

Since the backlight is turned off for portions other than the effective display area of the LCD panel, it can be easily understood that the power consumption is reduced.

Specifically, this is a backlight control method for an LCD display, and when displaying on the LCD panel at a resolution lower than the maximum displayable resolution of the LCD panel, the display within the maximum displayable resolution area is performed. The backlight control of an area other than the effective display area which is a low resolution area is performed by software.

In a backlight control method for an LCD display, a backlight for illuminating the LCD panel from behind can display a backlight in dot units, and the maximum display resolution with respect to the maximum displayable resolution of the LCD panel. When displaying on the LCD panel at a resolution lower than the possible resolution, the backlight of a region other than the effective display region, which is the region of the lower resolution, of the maximum displayable resolution region is turned off. Further, in the above LCD backlight control method, the backlight illuminates the LCD panel in units of 10 dots, and the resolution is indicated by the number of the LCD display elements.

[0013]

Next, an embodiment of the present LCD backlight control system will be described with reference to the drawings.

As shown in FIG. 1, as a display for a television or a computer, software (driver, BIOS, AP (Application Program)) is used by using an LCD panel capable of controlling a backlight in units of several dots.
m), etc., which means a program incorporated in a CPU that controls a backlight that can be turned on / off in dot units) by 1n [0],
[0], n [1], [0]... N [x], [y] are managed, and the display area of the LCD and the control of the light-on and light-off areas of the backlight are controlled. At this time, control is performed based on the resolution information and the maximum displayable resolution information of the LCD panel. In this control, the code based on the flowchart of FIG. 2 is incorporated into software (driver, BIOS, AS, or the like described above) that operates in accordance with a display start instruction, resolution switching, and the like.

Next, the operation of the embodiment of the present system will be described with reference to FIG. In step A-1, the control is shifted by a display start instruction and a command such as resolution switching. At step A-2, the entire LCD panel (n in FIG. 1)
The backlights of [0], [0] to n [[x], [y]) are turned off. In step A-3, the resolution to be displayed is obtained, and in step A-4, the maximum display resolution is obtained, and necessary information is read in for the next processing. Step A-5
At step A- based on the information read at step A-3
If it is smaller than the information read in step 4, it is determined that an invalid display area exists, and the process proceeds to step A-8, and otherwise to step A-6. In step A-6, LC
The entire D panel (n [0], [0] to n [[x],
[Y]) is to determine whether to turn on the backlight. If the resolution is such that it can be displayed on the LCD panel, the process proceeds to step A-7 and the entire LCD panel (n in FIG. 1)
The backlight is turned on at [0], [0] to n [[x], [y]). Otherwise, the process proceeds to step A-9, and the process ends. In step A-8, the start position and the end position of the effective display area are calculated, and the backlight of only the effective display area is turned on.

The backlight used in this embodiment is as follows.
Like the LCD display, it is necessary to be able to control blinking in dot units. The blinking of the dot unit is provided with a point light source in a matrix form.
(Field Emission) and a white fluorescent film are combined to develop a backlight light source. An LCD display is provided by providing an LCD display surface on the surface of the backlight. Then, the FE electron-emitting device is arranged at each light spot in the matrix, and an electrode coated with a phosphor is provided at the opposing point, and electrons are always emitted from the effective display area to thereby emit the electrons. The phosphor in the region emits light. At this time, no current is supplied to the FE in the invalid area which is an unused area. In this way, the present embodiment can be implemented by causing the backlight to emit light only in the effective area that is the use area. In addition, as a device capable of controlling a backlight for each pixel, a white or LCD pixel is provided on a transparent electrode side to which a high voltage is applied on a surface on which MIM (Metal-Insulator-Metal) type electron-emitting devices are arranged in a matrix. RGB corresponding to
Is applied to achieve a backlight corresponding to the resolution. Such a backlight mechanism may be of another type.

[0017]

Next, the configuration of an embodiment of the present LCD backlight system will be described. 800 x 600 maximum displayable resolution
In a panel having dots, when the management dots of n [0], [0] to n [[x], [y] are 10 × 10 dots in dot units shown in FIG. 1, 800 × 600 dots or less When displaying a resolution of 800 × 600 dots, and when displaying a resolution of 800 × 600 dots or more, there are three possibilities. The operation of these three points will be described below.

The operation of the configuration of the embodiment will be described with reference to FIG. In the process of step A-3 in FIG.
When the information for displaying the resolution of 0 × 480 dots has been obtained, the process of step A-5 is performed, and the process proceeds to step A-8. In step A-8, the display position is calculated, and as a result, n [8], [6] / n [71],
The area surrounded by [6] / n [8], [53] / n [71], and [53] is the effective display area. The backlight of only this part is turned on.

Next, the operation of the embodiment will be described with reference to FIG. In the process of step A-3 in FIG.
When the information for displaying the resolution of 00 × 600 dots is obtained, the entire LCD panel (n [0], [0] / n in FIG. 3) is processed through the processing of step A-5 and the processing of step A-6.
[79], [0] / n [0], [59] / n [79],
The backlight of the area enclosed by [59] is turned on.

Finally, the operation for explaining the configuration of the embodiment will be described with reference to FIG. In the process of step A-3, 10
When the information for displaying the resolution of 24 × 768 dots is acquired, the process proceeds to step A-9 via step A-5 and step A-6, and the process ends.

[0021]

According to the present invention, since the backlight other than the effective display area is turned off, it is possible to reduce power consumption at a resolution lower than the maximum displayable resolution of the LCD panel.

Also, since only the used area is displayed on the LCD display screen and the unused area is not displayed, power is not supplied in the unused area, and the deterioration of the LCD display device and the backlight can be prevented. .

[Brief description of the drawings]

FIG. 1 is a management chart in dot units in an LCD panel of the present invention.

FIG. 2 is a backlight control flowchart of the present invention.

FIG. 3 shows 640 × 4 on an 800 × 600 dot screen.
It is an 80 dot display figure.

FIG. 4 shows 640 × 4 on an 800 × 600 dot screen
It is an 80 dot display figure.

[Explanation of symbols]

A-1 START step A-8 Calculation of effective display area and backlight lighting step A-9 END step

Claims (3)

[Claims] 1. A backlight control method for an LCD display, wherein a display is performed on the LCD panel at a resolution lower than a maximum displayable resolution of the LCD panel.
An LCD backlight control system, wherein the backlight of an area other than the effective display area which is the lower resolution area in the maximum displayable resolution area is controlled by software. 2. A backlight control method for an LCD display, wherein a backlight for illuminating the LCD panel from behind enables a backlight display in dot units, and the maximum display resolution with respect to the maximum displayable resolution of the LCD panel. When displaying on the LCD panel at a resolution lower than the possible resolution, the backlight of the area excluding the effective display area, which is the area of the lower resolution, of the maximum displayable resolution area is turned off. Backlight control method. 3. The LCD backlight control system according to claim 1, wherein the backlight illuminates the LCD panel in units of 10 dots, and the resolution is equal to the resolution of the LCD panel.
LC characterized by the number of CD display elements
D backlight control system.