JPH0695069A - Power-saving type flat panel display device - Google Patents

Abstract

PURPOSE:To extend the usable time of a battery-driven type personal computer, a word processor, etc., by saving the electric power of a display device in a normal use state while securing its display quality. CONSTITUTION:The flat panel display device which is equipped with a back light 5 emitting light and a flat panel 11 controlling the transmission of light from the back light 5 and performs display control over data is provided with a display component decision part 3 which acquires a light shield rate as the rate of dots cutting the light from the back light 5 to the entire display screen of the flat panel 11 and a back light dimming/increasing control part 4 which adjusts the brightness of the back light 5 by comparing the light shield rate obtained by the display component decision part 3 with a specific value.

Description

Detailed Description of the Invention

[0001]

The present invention relates to an LCD (Liquid).
The present invention relates to a flat panel display device such as a crystal display (liquid crystal display), and more particularly, to a power saving flat panel display device suitable for use in a small computer device such as a portable personal computer or a warp that requires power saving. It is a thing.

[0002]

2. Description of the Related Art In recent years, computers have been miniaturized, and the major contribution to the miniaturization of computers has been flat panel displays such as LCDs and plasmas that replace CRTs (Cathode Ray Tubes). It is a device. Among them, the LCD has low power consumption, and in particular, is often used in a battery-powered portable small computer. However, LCDs do not self-luminece like CRTs and plasmas. Therefore, there are many problems in display quality such as low contrast.

In order to solve such a problem of the LCD, it is effective to make a backlight emit light behind the transmissive LCD. As a result, sufficient brightness can be secured and display quality can be improved. However, since the power consumption of the backlight is increased, the life of the battery is greatly reduced.

As a conventional technique for solving such a problem, for example, there is one described in Japanese Patent Laid-Open No. 1-237810. In this technique, the backlight is turned off in a situation where display is considered unnecessary, for example, when the user is not actually performing an operation, and is turned on when the user starts the operation. In addition, JP-A-2-
As described in Japanese Patent No. 216514, there is a technique in which, when the battery life becomes short, the brightness of the backlight is lowered to reduce the power consumption to prolong the battery life.

However, in these conventional techniques for saving power, the display quality is not ensured, and the operability is deteriorated in exchange for extending the battery life. For example, JP-A 1-2
In the technique described in Japanese Patent No. 37810, the backlight can be turned on by key input. However, since the actual turning off of the backlight is performed when the user keeps the unused state for a long time, in the normal use state. , Power saving effect cannot be expected. Further, in the technique described in JP-A-2-216514, since it is forcibly performed when the life of the battery is short, the battery must be charged in order to ensure display quality, and power saving is required. Cannot be effectively converted.

[0006]

The problem to be solved by the prior art is that in the conventional technique, the backlight is turned off or dimmed only in an emergency state such as a long unused state or a state where the battery life is short. That is, it is impossible to save power while ensuring display quality. An object of the present invention is to solve the problems of these conventional techniques, provide power saving in a normal use state, and provide a power saving type flat panel display device capable of power saving while ensuring display quality. It is to be.

[0007]

In order to achieve the above object, a power-saving flat panel display device of the present invention comprises:
(1) In a flat panel display device that includes a backlight that emits light and a flat panel that controls transmission of light from the backlight, and that controls display of data, a flat panel display device that controls the entire display screen of the flat panel from the backlight. A display component determination unit that acquires a light blocking ratio that is a ratio of dots that block light, and a backlight that adjusts the brightness of the backlight based on a comparison between a light blocking ratio acquired by this display component determination unit and a predetermined value. A dimming / increasing control unit is provided. (2) In the power-saving flat panel display device described in (1) above, a flat panel inversion / normal rotation control unit for switching inversion / normal rotation of the entire display screen of the flat panel is provided, and backlight dimming is performed. The / brightness control section is characterized in that the brightness of the backlight is adjusted in accordance with the operation of the flat panel inversion / normal rotation control section for inversion / normal rotation switching. (3) In the power-saving flat panel display device according to (1) or (2) above, a data counting unit that counts the number of pieces of data constituting one screen to be displayed is provided, and The light dimming / increasing control unit is characterized in that the brightness of the backlight is adjusted based on the shading ratio each time the number of data counted by the data counting unit reaches a predetermined value.
(4) In the power-saving flat panel display device according to any one of (1) to (3), the backlight dimming / increasing control unit has a predetermined value used for comparison with a light blocking ratio, and a backlight. The degree of change in the brightness of the backlight adjusted by the light dimming / brightening control unit, the selection information on whether or not to perform the adjustment operation of the backlight dimming / brightening control unit, and the predetermined number of data counted by the data counting unit And a backlight brightness reduction / brightening control section for selectively adjusting the brightness of the backlight on the basis of a condition arbitrarily set and registered in the operation condition storage unit. Is characterized by.

[0008]

In the present invention, when the screen to be displayed has many parts that block the backlight, the brightness of the backlight is not required so much, so that the brightness of the backlight is reduced and the power consumption is reduced. Further, when there are few parts that block the backlight, the normal backlight brightness is set to ensure display quality. As described above, by adjusting the brightness of the backlight according to the display state of the screen, it is possible to save power without deteriorating the display quality. The brightness of the backlight is adjusted, for example, on a black-and-white flat panel or the like when switching between inversion / normal rotation of the screen used for improving display quality. Also,
In the screen to be displayed, the ratio of the part that blocks the backlight in the entire screen is used as a criterion for determining whether there are many parts that block the backlight.
Also, by making it possible to select the degree of adjustment of the backlight brightness, it is possible to deal with screens having various characteristics.

[0009]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of the configuration of the power-saving flat panel display device of the present invention according to the present invention. In the figure, reference numeral 1 is related to the present invention, the degree of the brightness of the backlight to be changed, a predetermined value of the light shielding ratio used for the determination of the screen to be adjusted in brightness, and selection information on whether or not to perform brightness adjustment. The operation condition storage unit 2 for registering, etc. controls the power value supplied to the backlight,
The backlight brightness control unit 3 that adjusts the brightness of the backlight is related to the present invention, and the display component determination unit 4 that acquires the light blocking ratio, which is the ratio of the dots blocking the light from the backlight with respect to the entire screen to be displayed, is 4. , Related to the present invention,
A backlight dimming / brightening control unit that controls the backlight brightness control unit 2 to adjust the brightness of the backlight based on a comparison between the light blocking ratio acquired by the display component determination unit 3 and a predetermined value. Reference numeral 5 denotes a backlight device that emits light by electric power supplied via the backlight brightness control unit 2.
Reference numeral 6 is a display frame buffer for storing data to be displayed, 7 is a display control unit for converting the data stored in the display frame buffer 6 into display data corresponding to the display device, and 8 is an inversion / correction of the display screen. A display inversion / normal rotation switching request input unit for performing input control of a rotation switching request, 9 is a display screen inversion / normal rotation switching request from an operator or an application program, and 10 is a brightness-adjusted display image,
Reference numeral 11 is a flat panel that controls light shielding of the backlight device 5 based on display data, and 12 is a flat panel drive that controls light shielding / transmissivity of each element (dot) of the flat panel 11 based on display data. The control unit 13 is the light-shielding property of the flat panel drive control unit 12.
The flat panel inversion / normal rotation control unit 14 for inverting the switching of the transparency is a data counting unit for counting the number of input display data according to the present invention.

The operation of the power-saving flat panel display device of this embodiment having the above structure will be described below. First, the display data is input to the display frame buffer 6 via the display data counting unit 14. Next, when the operator or the utility program or the like makes a request to reverse all the display screens or to switch the normal rotation, the display is reversed / displayed.
The forward rotation switching request input unit 8 sends this request to the backlight dimming / increasing control unit 4 and the flat panel inversion / normal rotation control unit 1.
Notify 3 at the same time.

The flat panel inversion / normal rotation control unit 13 is
The display control unit 7 reads from the display frame buffer 6,
The flat panel drive control unit receives the converted image information signal for the flat panel drive control unit 12 and logically inverts / normally rotates the image information signal according to the notification from the display inversion / normal rotation switching request input unit 8. Send to 12. Normally, when the screen is reversed, the logic is reversed, and when the screen is rotated normally, no processing is performed. The flat panel drive control unit 12 drives the flat panel 11 using the image information signal received from the flat panel inversion / normal rotation control unit 13. In this state, an image is displayed on the flat panel 11.

On the other hand, the inversion / inversion notified to the backlight dimming / increasing control unit 4 from the display inversion / normal rotation switching request input unit 8.
In response to the forward rotation request, the backlight is controlled as follows. First, the backlight dimming / increasing control unit 4 causes the display component determining unit 3 to read out the display frame buffer 6 from the display frame buffer 6 and calculate the ratio of the color components that shield the backlight on the screen to be displayed (shading). Ratio). The color component that blocks the backlight is usually “black” in many cases. In addition, various techniques can be considered for the technique of acquiring the light shielding ratio in the display component determination unit 3. For example, in the case of monochrome two-color display, the number of dots indicating “on” may be simply divided by the total number of dots in the display frame buffer 6, and in the case where gradation is added, each dot is displayed. Therefore, it is possible to weight the gradation. Since these techniques are not the main subject of the present invention, the details are omitted, but the point is that the display component determination unit 3 uses the display frame buffer 6 to determine how much the screen to be displayed blocks the backlight. By reading out, the backlight dimming / increasing control unit 4 is quantitatively notified.

The backlight dimming / increasing control unit 4 judges the notification from the display component judging unit 3 based on the operating condition of the operating condition storage unit 1. If it can be determined that there are many color components that block the backlight, the backlight brightness control unit 2 is requested to reduce the light intensity, and when the color components are less, the backlight brightness control unit 2 is increased. Ask to do. The backlight brightness control unit 2 adjusts the brightness of the backlight by increasing or decreasing the power supplied to the backlight device 5 based on the request from the backlight dimming / increasing control unit 4. Then, finally, the display image 10 by the backlight device 5 and the flat panel 11 reaches the eyes of the user.

As described above, since the backlight device 5 is optimized according to the display contents of the flat panel 11,
The power consumption of the backlight can be reduced without deteriorating the display quality. The display data counting unit 1
In 4, the received display data is sent to the display frame buffer 6 and the number of display data is counted to obtain a predetermined value,
For example, when the number of characters reaches 500, the counted value is reset to zero (0) and the backlight dimming / luminance control unit 4 is adjusted to adjust the brightness of the backlight according to the present invention, that is, dimming the backlight. / Issue a request to start the brightness control operation.

FIG. 2 is an explanatory diagram showing an embodiment of each operating condition registered in the operating condition storage section in FIG. In the figure, "backlight automatic dimming / brightening control processing valid / invalid information" 21 indicates whether or not the backlight dimming / brightening control unit 4 of FIG. The selection information, “the ratio of the display“ black ”component that is automatically dimmed” 22 ”is the backlight dimming /
The predetermined value used by the brightness increase control unit 4 for comparison with the light blocking ratio obtained from the display component determination unit 3 in FIG. 1, particularly, the predetermined value used for dimming, “automatic dimming brightness change degree” 23
Is the degree of change in the brightness of the backlight that is adjusted by the backlight dimming / brightening control unit 4 of FIG. 1 when the light is dimmed, and the “proportion of the display“ black ”component that automatically dims” 24 is the backlight of FIG. A predetermined value used by the light dimming / brightening control unit 4 for comparison with the light-shielding ratio obtained from the display component determination unit 3 in FIG. “25” is the degree of change in the brightness of the backlight adjusted by the backlight dimming / increasing control unit 4 in FIG. 1 when the light is increased.

Since such operating conditions are arbitrarily set, it is possible to selectively operate the brightness adjustment of the backlight by the backlight dimming / increasing control section 4 of FIG.

FIG. 3 is an explanatory view showing the concept of setting the operating conditions registered in the operating condition storage section in FIG. In this figure, 31 is "black" of the screen to be displayed.
The ratio of components "is indicated by" 0% to 100% ".
In the present embodiment, A% in the drawing is a value of the ratio corresponding to “the ratio of the display“ black ”component that is automatically dimmed” 22 in FIG. 2, and the determination result of the display component determination unit 3 in FIG. This A% ~
If it is between 100%, the backlight dimming / brightening control unit 4 in FIG. 1 uses the “automatic dimming luminance change degree” 23 in FIG.
Dimming control is performed with a value corresponding to.

Further, B% in the drawing is a value of the ratio corresponding to "the ratio of the display" black "component which is automatically brightened" in FIG. 2, and the judgment result of the display component judging unit 3 in FIG. B
If it is between 0% and 0%, the backlight dimming / brightening control unit 4 of FIG.
Intensity control is performed with a value corresponding to. If the determination result of the display component determination unit 3 in FIG. 1 is between A% and B%,
The backlight dimming / increasing control unit 4 of FIG. 1 performs control at normal brightness. Based on such a concept, the backlight dimming / increasing control unit 4 of FIG. 1 is different from the backlight brightness control unit 2 of FIG. 1 in the backlight device 5 of FIG. 1 as shown in FIG. Request the power supply control to.

FIG. 4 shows the backlight dimming /
6 is a flowchart showing an embodiment of a processing operation according to the present invention of a brightness control section. If there is a switching request from the display inversion / normal rotation switching request input unit 8 in FIG. 1 (step 401),
Alternatively, if the number of data from the display data counter 14 of FIG. 1 reaches a predetermined value (step 402),
Each operation condition is acquired from the operation condition storage unit 1 (step 403). Of the operating conditions, "backlight automatic dimming / brightening control processing valid / invalid information" 21 in FIG. 2 is valid,
If it is necessary to adjust the brightness (step 404), the light shielding ratio of the display screen obtained by the display component determination unit 3 in FIG. 1 is acquired (step 405).

It is determined whether or not this light-shielding ratio is larger than a predetermined value for dimming, which is indicated by "the ratio of the display" black "component to be automatically dimmed" 22 in FIG.
06). If it is larger, the backlight brightness control unit 2 of FIG. 1 is requested to reduce the brightness by a predetermined degree indicated by the “automatic brightness reduction degree of brightness change” 23 of FIG. 2 (step 407), and If it is smaller, then it is determined whether or not it is smaller than a predetermined value for light increase indicated by "the ratio of the display" black "component for automatic light increase" 24 in the operating condition of FIG. 2 (step 4).
08). If it is smaller, the backlight brightness control unit 2 of FIG. 1 is requested to increase the brightness by a predetermined degree indicated by the “automatic brightness increase degree of brightness” 25 of the operating condition of FIG. 2 (step 409). Then, the backlight brightness control unit 2 of FIG. 1 is requested to set the normal brightness (step 410).

As described above with reference to FIGS. 1 to 4, in the flat panel ideographic device of this embodiment, the brightness of the backlight is adjusted based on the ratio of the portion of the screen to be displayed that blocks the backlight. . For example, if the entire display screen is reversed to display the character "white", the backlight is almost blocked and only the character portion is passed.
In such a case, the backlight is automatically dimmed.
In this way, the brightness of the backlight is adjusted by determining the amount of the part that blocks the backlight of the display screen, so whatever the screen is displayed, it is the most suitable and low power consumption backlight at that time. The light brightness can be automatically selected, and the power consumption of the display device can be efficiently reduced even during normal use. Further, when the inversion or the normal rotation switching of the entire display screen in which the display state changes greatly occurs, the backlight is dimmed or brightened. As a result, the power consumption of the backlight can be reduced with almost no notice to the user.

Further, when the backlight is dimmed or brightened, the ratio of the "black" display component that blocks the backlight on the current display when dimming or brightening, the invalidation of this control itself, etc. Since each of them is selectable, it can be adapted to various conditions such as the display method of the program to be used and the state around the device. For example, when an AC power source is used, it is not necessary to worry about power consumption, and therefore it is possible to always use the image with high brightness again. still,
The present invention is not limited to the embodiments described with reference to FIGS. 1 to 4, and various modifications can be made without departing from the scope of the invention.

[0023]

According to the present invention, the power consumption of the display device can be saved in the normal use state while ensuring the display quality, and the display device can be driven by a battery such as a portable word processor or a personal computer. It is possible to extend the usable time of the computer equipment and improve its performance.

[0024]

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a configuration according to the present invention of a power-saving flat panel display device of the present invention.

FIG. 2 is an explanatory diagram showing an example of each operating condition registered in an operating condition storage unit in FIG.

FIG. 3 is an explanatory diagram showing the concept of setting operation conditions registered in an operation condition storage unit in FIG.

FIG. 4 is a flowchart showing an embodiment of a processing operation according to the present invention of the backlight dimming / increasing control unit in FIG.

[Explanation of symbols]

1 Operation Condition Storage Unit 2 Backlight Brightness Control Unit 3 Display Component Judgment Unit 4 Backlight Dimming / Brightening Control Unit 5 Backlight Device 6 Display Frame Buffer 7 Display Control Unit 8 Display Inversion / Normal Rotation Switching Request Input Unit 9 Switching Request 10 Display Image 11 Flat Panel 12 Flat Panel Drive Control Section 13 Flat Panel Inversion / Normal Rotation Control Section 14 Data Counting Section 21 “Backlight Automatic Dimming / Brightening Control Processing Effective / Invalid Information” 22 “Automatic Dimming Display“ Black "Component ratio" 23 "Automatic dimming luminance change degree" 24 "Automatic brightening display" black "component proportion" 25 "Automatic brightening luminance change degree" 31 "Display screen" black "component proportion"

Claims (4)

[Claims] 1. A flat panel display device, comprising: a backlight that emits light; and a flat panel that controls transmission of light from the backlight, wherein the flat panel display device controls display of data. A display component determination unit that acquires a light blocking ratio that is a ratio of dots that block light from the backlight, and a light blocking ratio acquired by the display component determination unit, based on a comparison with a predetermined value,
A power-saving flat panel display device comprising a backlight dimming / increasing control means for adjusting the brightness of the backlight. 2. The power-saving flat panel display device according to claim 1, further comprising flat panel inversion / normal rotation control means for performing inversion / normal rotation switching of the entire display screen of the flat panel. A power-saving flat panel display device characterized in that the light / brightening control means adjusts the brightness of the backlight in accordance with the reversal / normal rotation switching operation of the flat panel reversal / normal rotation control means. 3. The power-saving flat panel display device according to claim 1 or 2,
A data counting means for counting the number of data constituting one screen to be displayed is provided, and the backlight dimming / increasing control means is arranged so that the light shielding is carried out each time the number of data counted by the data counting means reaches a predetermined value. A power-saving flat panel display device, characterized in that the brightness of the backlight is adjusted based on a ratio. 4. The power-saving flat panel display device according to claim 1, wherein the backlight dimming / increasing control means uses the predetermined value used for comparison with the light shielding ratio. , The degree of change in the brightness of the backlight adjusted by the backlight dimming / increasing control means, selection information on whether or not to perform the adjustment operation of the backlight dimming / increasing control means, and the data counting means. An operating condition storage means for registering the predetermined value of the number of data to be counted is provided, and the backlight by the backlight dimming / brightening control means is based on the condition arbitrarily set and registered in the operating condition storage means. Power-saving flat panel display device characterized in that the brightness of the display is selectively adjusted.