JP3202007B2 - Image display device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image display device such as a plasma display device, an electroluminescence display device, and a light emitting diode display device.

[0002]

2. Description of the Related Art Conventionally, light-emitting image display devices such as a plasma display device, an electroluminescence display device and a light-emitting diode display device generally emit light when there is an amount of information to be displayed. When the amount is large, the power consumption naturally increases. Therefore, studies have been made to limit the power consumption when the amount of display data becomes large. In JP-A-8-65607,
Automatic power control (AP
A technique is disclosed in which the light emission amount (luminance) per unit area of the display unit is adjusted in part C) according to a change in the average luminance signal level, so that power consumption is not excessively increased.

[0003]

FIG. 11 is a block diagram showing the configuration of the image display device disclosed in the above publication. R, G, and B signals are input from respective terminals as video signals. R, G, B input from each terminal
Is input to the Y encoding circuit 61, where R,
The G and B signals are encoded and output as luminance signals (hereinafter, referred to as Y signals). The output Y signal is integrated by the digital luminance integration circuit 62 to output an average luminance.

The memory control unit 63 uses the average luminance output from the digital luminance integration circuit 62 as a parameter, receives data corresponding to the average luminance from the memory 64, and outputs the data to the automatic power control unit 66 of the plasma display device 68.
The automatic power control unit 66 outputs to the PDP 67 a control signal for adjusting the light emission amount (luminance) per unit area of the PDP (plasma display panel) display unit 67 according to the data output from the memory control unit 63, and Controlling power.

However, the power consumption of the PDP display is not proportional to the luminance signal. For example, in a Y encoding circuit, Y = 0.3R + 0.
Assuming that the conversion formula of 59G + 0.11B is used, each luminance signal (YR) when displaying a single color of red (hereinafter, referred to as R), green (hereinafter, referred to as G), and blue (hereinafter, referred to as B) is displayed. : Luminance signal when monochromatic red is displayed, YG:
The ratio of the luminance signal when displaying a single green color and the luminance signal when YB: the luminance signal when displaying a single blue color is YR: YG: YB = 0.
3: 0.59: 0.11, the luminance signal YG when G is displayed is the largest, and the luminance signal YB signal when B is displayed is the smallest. , Another control is performed.
The coefficients (0.3, 0.59, 0.11) for obtaining the luminance signal in the above conversion equation are the three primary colors (R,
G, B) is the ratio at which the human eye perceives the brightness, and does not indicate the power consumption ratio, so inappropriate control is performed.

As described above, in the technique shown in the conventional example,
If the average luminance is used as a parameter for controlling the power consumption of the image display device, the light emission amount (luminance) of the display unit is perceived as being unnecessarily low when the image has more green components than other colors, and the blue component is also recognized. In the case of an image having more colors than other colors, it is recognized that the power consumption is greater than the capability of the power supply unit, so that there has been a problem that the automatic control of the power consumption and the light emission amount (brightness) cannot be performed accurately.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide an image display device with improved accuracy in power consumption control.

[0008]

In order to solve the above-mentioned problems, an image display device according to the present invention is provided with a power consumption for displaying data when three primary colors of red, green and blue are displayed in a single color. Using the ratio or a coefficient representing the area ratio of each color phosphor,
It is characterized in that the light emission amount (brightness) and the power consumption are controlled based on a power consumption prediction signal obtained by weighting each color average level and obtaining the sum.

According to the present invention, the power consumption and the light emission amount (brightness) are controlled based on the power consumption prediction signal calculated using the coefficient indicating the power consumption ratio or the area ratio of the phosphor. It is possible to control the power consumption and the amount of emitted light (luminance) independent of the hue of the signal.

More specifically, the image display device according to the present invention has the following configuration. In the first image display device according to the present invention, when the same image is displayed in a single color for the R, G, and B signals of the input image, the ratio of power consumed for each display is KR: KG: A panel which is KB and the input video signals R, G, and B for a predetermined period are integrated to obtain R
An integrating circuit that outputs each of the average level, the G average level, and the B average level;
First, second, and third multiplication circuits for multiplying each of the average levels by KR, KG, and KB;
A power consumption prediction signal indicating the predicted power consumption based on the output signal of the third multiplier circuit is obtained and output, and a power consumption prediction signal is input, and the power consumption is determined based on the value of the power consumption prediction signal. And a control circuit for controlling the amount of light emission per unit area so as to be limited to within the range.

[0011]

A second image display device according to the present invention is characterized in that, when the same image is displayed in a single color in R, G, and B signals of an input image, the ratio of the power consumed for each display is displayed. , KR: KG: KB, an integrating circuit for integrating the input video signals R, G, and B for a predetermined period and outputting each of an R average level, a G average level, and a B average level, and an R average level. , G, and B average levels respectively multiplied by KR, KG, and KB, and consumption based on output signals of the first, second, and third multiplier circuits. A circuit for obtaining and outputting a power prediction signal; a controller for receiving the power consumption prediction signal and outputting a multiplication coefficient for limiting power consumption within a predetermined range based on a value of the power consumption prediction signal; and an input video signal Delay R, G, B respectively Comprising a delay circuit for outputting video signals DR, DG, and DB, the delayed video signal DR, DG, fourth multiplying respectively DB and multiplication coefficient, a fifth and a multiplication circuit of the sixth.

A third image display apparatus according to the present invention divides one field of a video signal into a plurality of weighted subfields, and superimposes the images of the subfields temporally to display the gradation. An image display device for performing display, wherein when the same image is displayed in a single color with R, G, and B signals of an input image displayed in a single color, a ratio of power consumed for each display is KR: KG: A panel which is a KB and an input video signal R for at least one field,
An R integrating circuit for integrating each of G and B and outputting each of an R average level, a G average level, and a B average level;
An integration circuit, a B integration circuit, a first multiplication circuit, a second multiplication circuit, and a third multiplication circuit for multiplying each of the R average level, the G average level, and the B average level by KR, KG, and KB, respectively; A power consumption prediction signal is obtained from the outputs of the first, second, and third multiplication circuits, and the power consumption prediction circuit to be output and the power consumption prediction signal are input, and the value of the power consumption prediction signal is input. A controller that outputs a light emission pulse control signal for selecting a light emission format whose power consumption is limited to a predetermined range based on the input video signals R, G,
B, each of which delays B and outputs a delayed video signal DR, DG, DB, and a subfield of a light emitting format corresponding to the light emitting pulse control signal, which receives the light emitting pulse control signal and the delayed video signals DR, DG, DB. A video signal-subfield associator for associating the output signal of the delay circuit with the configuration, and a light emission pulse control signal are input, and scanning, maintenance, erasure, etc. are performed in a light emission type subfield configuration based on the light emission pulse control signal. Subfield pulse generating means for generating a pulse.

A fourth image display apparatus according to the present invention divides one field of a video signal into a plurality of weighted subfields, and superimposes and displays the images of the subfields temporally to thereby achieve gradation. An image display device for performing display, wherein when the same image is displayed in a single color with R, G, and B signals of an input image displayed in a single color, a ratio of power consumed for each display is KR: KG: A panel which is a KB, an R integrating circuit which integrates the input video signals R, G, and B for at least one field and outputs an R average level, a G average level, and a B average level;
An integration circuit, a B integration circuit, a first multiplication circuit, a second multiplication circuit, and a third multiplication circuit for multiplying each of the R average level, the G average level, and the B average level by KR, KG, and KB, respectively; A power consumption prediction signal is obtained from the outputs of the first, second, and third multiplication circuits, and the power consumption prediction circuit to be output and the power consumption prediction signal are input, and the value of the power consumption prediction signal is input. A light emission pulse control signal for selecting a light emission format in which power consumption is limited within a predetermined range based on the multiplication factor, and a multiplication coefficient for correcting a gradation so that luminance becomes equal at a light emission format switching point. A controller, a delay circuit for delaying the input video signals R, G, and B, and outputting the delayed video signals DR, DG, and DB; and a fourth circuit for multiplying the delayed video signals DR, DG, and DB by the multiplication coefficient, respectively. , Fifth, 6, a light emitting pulse control signal and output signals of the fourth, fifth, and sixth multiplying circuits are input, and the fourth, fifth, and fifth light emitting subfield configurations corresponding to the light emitting pulse control signal are input. , A video signal-subfield associator for associating the output signal of the sixth multiplier circuit,
A subfield pulse generating means for receiving a light emission pulse control signal and generating a pulse for scanning, sustaining, erasing, etc. in a light emission type subfield configuration based on the light emission pulse control signal;

In the above-described image display device, the parameters KR, KG, and KB may be values corresponding to the ratio of the areas of the red phosphor, the green phosphor, and the blue phosphor that emit light during display. Since the area of the phosphor is substantially proportional to the power consumption, the power consumption prediction signal can be easily estimated by weighting each color average level using a coefficient representing the area ratio of the phosphor and then taking the sum. .

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the image display device according to the present invention will be described in detail with reference to the accompanying drawings.

(Embodiment 1) FIG. 1 is a block diagram showing an embodiment of the image display device of the present invention. The display device includes three integration circuits 11, 12, and 13, and first to third integration circuits.
Multiplication circuits 14, 15, 16, an addition circuit 17, a controller 18, a delay circuit 19, fourth to sixth multiplication circuits 20, 21, 22, a video signal-subfield correspondence unit 23, Subfield pulse generation circuit 24
Scanning side driver 25, data side driver 26,
And a PDP panel 27.

An R integration circuit 11, a G integration circuit 12, and a B integration circuit 13 receive an R signal, a G signal, and a B signal as input video signals, respectively, for a specific period, for example, at least one signal.
Signals for the fields are integrated, and values obtained by dividing by the number of integrated pixels are output as an R average level, a G average level, and a B average level.

The R average level, the G average level, and the B average level are input to a first multiplier 14, a second multiplier 15, and a third multiplier 16, respectively. KG and KB are multiplied, and the result is output to the addition circuit 17. Here, coefficients KR, KG,
KB is set to a value such that the ratio of these coefficients becomes equal to the power ratio of each color consumed when displaying an image under the same condition in each color of RGB in a single color. That is, image signals under the same conditions are sequentially input as R, G, and B signals in a state where power control by the controller 18 described later is not operated, and consumed for data display when each of R, G, and B is displayed in a single color. The measured power is measured in advance so that the measured power ratio of each color is equal to the ratio of the coefficients KR, KG, and KB. For example, if the power consumption when a certain image is displayed in red is PR, the power consumption when the same image as that image is displayed in green is PG, and the power consumption when the same image is displayed in blue is PB, PR: PG: PB = KR : KG:
The coefficient is determined so that KB is satisfied.

The first multiplier 14 multiplies the coefficient KR to the R average level, the second multiplier 15 multiplies the coefficient KG to the G average level, and the third multiplier 16 multiplies the coefficient KB to the B average level. . The adder circuit 17 includes the first multiplying circuit 1
4. A power consumption prediction signal is obtained by adding the output signals from the second multiplication circuit 15 and the output signal from the third multiplication circuit 16 and output. The controller 18 inputs the power consumption prediction signal, adjusts the light emission amount (luminance) per unit area of the display device, selects a light emission format that does not cause excessive power consumption, and emits light corresponding to the light emission format. Outputs the pulse control signal. At the same time, the controller 18 calculates and outputs a multiplication coefficient so that there is no difference in the light emission amount (luminance) of the video between different light emission formats. Details of these operations of the controller 18 will be described later.

The delay circuit 19 receives input video signals R, G, B
, And integrating circuits 11, 12, 13, a multiplying circuit 14,
15, 16, and outputs delayed video signals DR, DG, and DB delayed by the sum of the time required for the processing of each unit of the adding circuit 17 and the controller 18. Delayed video signal D
R, DG, and DB are input to the fourth, fifth, and sixth multiplication circuits 20, 21, and 22, respectively, multiplied by the multiplication coefficient output from the controller 18, and output.

Video signal-subfield correlator 23
Input the output signals of the fourth, fifth, and sixth multiplication circuits 20, 21, and 22 and the light emission pulse control signal from the controller 18, and output the fourth, fifth, and sixth powers expressed as powers of two. The output signals of the multiplication circuits 20, 21, and 22 are converted into a light emission pattern of a subfield configuration of a light emission format corresponding to the light emission pulse control signal, and the first sub-field of each pixel is generated at a predetermined timing during one field period. The data of the field, the data of the second subfield,..., The data of the nth subfield are sequentially transmitted (where n is the number of subfields). Note that the video signal-subfield correlator 2
In 3, a predetermined process such as conversion of the number of subfields for suppressing generation of a pseudo contour may be performed.

The subfield pulse generation circuit 24 receives a light emission pulse control signal and supplies a scanning, sustaining and erasing signal to the scanning driver 25 in a light emission type subfield configuration according to the light emission pulse control signal. The scanning driver 25 scans, maintains, and erases signals at a predetermined voltage level to P
It is supplied to each row electrode of the DP panel 27.

The data driver 26 receives an output signal from the video signal-subfield correlator 23, generates an image data pulse having a voltage value corresponding to each pixel data, and divides the image data pulse for each column. Are supplied to the column electrodes of the PDP panel 27 in synchronization with the signal output from the scanning driver 25. The PDP panel 27 is driven in this way, and an image corresponding to the input video signal is displayed.

In the display device of this embodiment, even when the input video signal changes and the amount of information to be displayed becomes large and the power consumption naturally increases, the display is performed so as to limit the power consumption within a certain range. Controls the amount and brightness of light emitted by the device. That is, the light emission format (light emission time and the number of times of light emission) and the gradation of the displayed image are controlled so that the power consumption during image display does not become larger than a certain reference value P. For this reason, the display device predicts power consumption based on the input video signal, and emits light (emission time or number of times of emission) such that the power consumption is limited within a predetermined range based on the predicted power consumption.
And to control the gradation.

More specifically, the controller 18 selects a light emission format (emission time or number of times of emission) according to the value of the power consumption prediction signal, and outputs a light emission pulse control signal for controlling this light emission format and a different light emission format. And a multiplication coefficient for adjusting the gradation level of the input video signal so that the light emission amount / luminance of the display device changes smoothly between the two.

Hereinafter, a method of determining the light emission format and the multiplication coefficient in the controller 18 will be described.

First, the light emission format will be described. In this display device, as shown in FIG. 2, as the value of the power consumption prediction signal increases, the total number of times of light emission becomes 1275, 102
There are five light emission modes A, B, C, D, and E, which are as small as 0, 765, 510, and 255.

For the 8-bit gradation levels from 0 to 255, the light emission format A is 5 times the gradation level, the light emission format B is 4 times the gradation level, and so on. D and the light emission format E are three times the gradation level,
The number of light emission pulses is set so as to emit light twice or one times.

These light emission types are switched based on a power consumption prediction signal. A description will be given of a power consumption prediction signal value (hereinafter referred to as a “switching point”) at which the light emission format is switched. FIG. 3 is a diagram for explaining the determination of the switching point of the light emission format, and is a diagram illustrating a relationship between the power consumption prediction signal and the power consumed for display. As shown in this figure, the light emission format A and the light emission format B have a predetermined value TB, the light emission format B and the light emission format C have a predetermined value TC, the light emission format C and the light emission format D have a predetermined value TD, and the light emission format D The light emission format E is switched at a predetermined value TE. The predetermined value TE is obtained, for example, as follows. That is, the input video signal is changed so that the power consumption prediction signal gradually decreases from the maximum, and the power consumption at that time is measured. At this time, the power consumption prediction signal is obtained by setting the multiplication coefficient to 1. The actual power consumption also decreases as the power consumption prediction signal decreases, and the value of the power consumption prediction signal when the power consumption reaches the reference value P is set as the switching point TE.

Since the total number of times of light emission of the light emission format D is twice the total number of times of light emission of the light emission format E, when the power consumption prediction signal is TE and displayed in the light emission format D, the power consumption is 2P.
Becomes With this point as a starting point, the power consumption prediction signal is gradually reduced in the same manner as described above, and the power consumption prediction signal value TD at which the power consumption becomes P is obtained. Hereinafter, similarly, the switching point T
C and TB can be obtained.

FIG. 4 is a flowchart showing the operation of the controller 18 when determining the light emission format based on the power consumption prediction signal. As shown in the figure, first, the power consumption prediction signal is compared with a predetermined value TB (S1), and when the value of the power consumption prediction signal is smaller than the predetermined value TB, the light emission format A is selected (S6). When the value of the power consumption prediction signal is equal to or larger than the predetermined value TB, the power consumption prediction signal is compared with the predetermined value TC (S2). If the value of the power consumption prediction signal is smaller than the predetermined value TC, the light emission format B is selected (S7). When the value of the power consumption prediction signal is equal to or larger than the predetermined value TC, the power consumption prediction signal is compared with the predetermined value TD (S3). If the value of the power consumption prediction signal is smaller than the predetermined value TD, the light emission format C is selected (S8). When the value of the power consumption prediction signal is equal to or greater than the predetermined value TD, the power consumption prediction signal is compared with the predetermined value TE (S
4). When the value of the power consumption prediction signal is smaller than the predetermined value TE, the light emission format D is selected (S9). When the value of the power consumption prediction signal is equal to or larger than the predetermined value TE, the light emission format E is selected (S5).

By the way, if only a light emission format having a different number of times of light emission is switched for a signal of the same gradation level, a difference in the number of times of light emission is detected as a luminance difference in the display device when the light emission format is switched. Therefore, it is necessary to adjust the gradation level of the input video signal. Further, as shown in FIG. 3, the power consumed for data display also greatly exceeds the reference value P. Therefore, the controller 18 outputs a multiplication coefficient that changes according to the power consumption prediction signal, and corrects the gradation to be actually displayed by multiplying the input video signal by the multiplication coefficient.

For example, when the power consumption prediction signal changes and the light emission format changes from the light emission format A to the light emission format B,
For signals of the same gradation level, (luminance in light emission format A): (luminance in light emission format B) =
(Number of light emission of light emission type A): (Number of light emission of light emission type B)
= 5: 4, the multiplication coefficient in the light emission format A is set to 1 when the power consumption prediction signal has a small value, and is set to decrease monotonically as the power consumption prediction signal increases. Is set to 4/5 = 0.8.
For example, when the gradation of the input video signal is 200, the gradation level is (200 × 0.8) in the light emission format A in which the power consumption prediction signal is in contact with the light emission format B region.
0.8) × 5 = 800 times, 200 × 4 = 80 in the light emission format B where the power consumption prediction signal is in contact with the light emission format A
0, so that the luminance on the display unit 22 can be made equal between the two light emission types.

The setting of the multiplication coefficient is the same for other changes in the light emission format, and the light emission format B becomes 1 to 0.75 (3/3) as the power consumption prediction signal increases.
4) In the light emission format C, it is set to 1 to 0.67 (2/3). By calculating the multiplication coefficient in this manner, it is possible to perform control so that a luminance difference is not detected in the display device even when the light emission format is switched.

Here, for simplicity of description, TB = 0.
2, TC = 0.4, TD = 0.6, TE = 0.8, the value of the power consumption prediction signal is x, and the multiplication coefficient is y, the relationship is as follows. Light-emitting format A: y = -x + 1 (x <0.2) (1) Light-emitting format B: y = -5 / 4.x + 5/4 (0.2 ≦ x <0.4) (2) Light-emitting format C: y = −5 / 3 · x + 5/3 (0.4 ≦ x <0.6) (3) Emission format D ... y = −5 / 2 · x + 5/2 (0.6 ≦ x <0.8) ( 4) Light emission format E ... y = ax + (1−0.8a) (0.8 ≦ x) (5) x ≧ 0.8 That is, the multiplication coefficient y in the light emission format E is x =
Since 0.8 is set to 1.0 and becomes smaller as x increases, a ≦ 0 and 0.8 ≦ x ≦ 1.
It is set appropriately so that the power consumption is limited to the reference value P at 0. For example, when x = 0.15, the light emission format A is selected, and the multiplication coefficient is calculated as y = −x + 1 = −0.15 + 1 = 0.85. FIG. 5 shows a change in the multiplication coefficient with respect to the power consumption prediction signal when the multiplication coefficient is determined as described above.

As described above, the controller 18 obtains the multiplication coefficient according to the power consumption prediction signal, so that the change of the power consumption with respect to the power consumption prediction signal changes from the characteristic shown in FIG. 3 to the characteristic shown in FIG. Become. Thus, power consumed for data display does not greatly exceed the reference value P regardless of the input video signal.

Although the multiplication coefficient is changed linearly in a certain section in FIG. 5, it may be changed in a curve as shown in FIG. Thereby, as shown in FIG. 8, the power consumption characteristic can be further restricted to the vicinity of the reference value P, which is more preferable.

As described above, the controller 18 determines these data (the light emission pulse control signal and the multiplication coefficient) in accordance with the value of the power consumption prediction signal. Reduce time,
The amount of light emission (luminance) per unit area of the display device is reduced by reducing the multiplication coefficient by which the delayed video signal is multiplied to make the gradation level of the signal displayed on the display device smaller than the gradation level of the input video signal. Is adjusted to control the power consumed by the display device.

Depending on the magnitude of the power consumption prediction signal, it is of course possible to control the light emission amount (brightness) and power control by adjusting only one of the switching of the light emission format or the multiplication coefficient.

As described above, in the present invention, a power consumption prediction signal is calculated using a coefficient representing a power consumption ratio necessary for displaying data of each color, and the power consumption prediction signal obtained in this manner is used as a parameter. Automatic power control can be performed more correctly than the conventional method.

FIG. 9 is a control characteristic showing the relationship between the power consumption prediction signal and the light emission amount (luminance) per unit area of the display device. The horizontal axis indicates the magnitude of the power consumption prediction signal, and the vertical axis indicates the light emission amount (luminance) per unit area. The controller 18 adjusts the light emission format and the multiplication coefficient in accordance with the power consumption prediction signal output from the addition circuit 17 to reduce the light emission amount (luminance) per unit area as the power consumption prediction signal increases. The control is performed so that the power consumed by the display device does not become too large.

(Embodiment 2) A second embodiment of the present invention will be described. In the present embodiment, another example of a method for determining coefficients KR, KG, and KB in (Embodiment 1) will be described. That is, in the first embodiment,
Coefficients KR, K based on the power ratio when each color is displayed in a single color
Although the values of G and KB are determined, in the present embodiment, the values are determined based on the area ratio of the phosphor of each color to emit light.

FIG. 10 is an example of a phosphor configuration diagram of a plasma display panel. In FIG. 10A, the width of each color phosphor having a stripe structure is WR: WG: WB =
Since 1.0: 1.0: 1.0, the discharge areas of R, G, and B are the same, and the power PR, PG consumed for displaying data when each single color is displayed on this panel. , PB
The ratio is generally PR: PG: PB = 1.0: 1.0:
1.0. In such a case, when obtaining the power consumption prediction signal, the ratio of KR, KG, and KB, by which the R average level, the G average level, and the B average level are respectively multiplied, is KR: KG:
Assuming that KB = 1.0: 1.0: 1.0, a power consumption prediction signal can be output.

Consider a case where the width of each color phosphor is unbalanced for the purpose of improving the color temperature as shown in FIG. 10B. In FIG. 10B, WR: WG: W
B = 1.0: 1.0: 1.4, and the color temperature of the panel is increased by making the width of the blue phosphor wider than the other two colors. At this time, the difference in the phosphor width becomes the difference in the discharge area of R, G, and B, which is reflected in the power consumed for data display, and is generally PR: PG: PB = 1.0:
1.0: 1.4. In such a case, KR, K
When the ratio of G and KB is KR: KG: KB = 1.0: 1.0:
With 1.4, the power consumption prediction signal can be correctly calculated.

As described above, since the area of the phosphor is substantially proportional to the power consumed for displaying data, the ratio of the area of the phosphor is KR, KG, and KB, and the first multiplying circuit 14 of FIG. It is also possible to easily calculate the power consumption prediction signal by inputting the respective signals to the second multiplier circuit 15 and the third multiplier circuit 16.

[0047]

As described above, according to the present invention, the power consumption prediction signal obtained by weighting each color average level using the coefficient representing the power consumption ratio or the phosphor area ratio and then obtaining the sum is obtained. By controlling the light emission amount (luminance) of the display unit of the display device based on the above, more accurate control of the power consumption is possible as compared with the conventional method of controlling the power consumption of the display device using the average luminance. Display device can be provided.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an image display device according to an embodiment of the present invention.

FIG. 2 is a diagram showing a light emission format of the image display device.

FIG. 3 is a diagram showing a correspondence between a power consumption prediction signal and power consumption of the same image display device when there is no gradation correction by a multiplication coefficient.

FIG. 4 is a flowchart showing a light emission format selection operation of the controller.

FIG. 5 is a diagram showing a correspondence between a power consumption prediction signal of the image display device and a multiplication coefficient.

FIG. 6 is a diagram illustrating a correspondence between a power consumption prediction signal of the same image display device after gradation correction using a multiplication coefficient and power consumption.

FIG. 7 is a diagram showing a correspondence between a power consumption prediction signal of the image display device and a multiplication coefficient (a second multiplication coefficient) of a different example.

FIG. 8 is a diagram showing a correspondence between a power consumption prediction signal and power consumption of the same image display device after gradation correction using a second multiplication coefficient.

FIG. 9 is a diagram showing control characteristics of a power consumption prediction signal of the image display device and a light emission amount (luminance) per unit area of the display device.

FIG. 10 is a diagram showing a configuration of a phosphor of a plasma display panel according to an embodiment of the present invention.

FIG. 11 is a block diagram showing a configuration of a conventional image display device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 R integration circuit 12 G integration circuit 13 B integration circuit 14 1st multiplication circuit 15 2nd multiplication circuit 16 3rd multiplication circuit 17 addition circuit 18 controller 19 delay circuit 20 4th multiplication circuit 21 5th multiplication circuit 22 Sixth Multiplying Circuit 23 Video Signal-Subfield Associator 24 Subfield Pulse Generating Circuit 25 Scanning Driver 26 Data Driver 27 PDP Panel

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-8-65607 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G09G 3/20 642 G09G 3/20 611 G09G 3/20 612 G09G 3/28

Claims (4)

(57) [Claims] 1. The R, G, and B signals of an input image are the same for each color.
And a panel in which the ratio of power consumed for each display when displaying the image in monochrome is KR: KG: KB, and the input video signals R, G, and B for a predetermined period are integrated. An integration circuit that outputs each of the R average level, the G average level, and the B average level; and a first circuit that multiplies each of the KR, KG, and KB by each of the R average level, the G average level, and the B average level. A second and a third multiplying circuit; a circuit for obtaining and outputting a power consumption prediction signal indicating a predicted power consumption based on an output signal of the first, the second and the third multiplying circuits; A prediction signal is input, and power consumption is limited to a predetermined range based on a value of the power consumption prediction signal.
And a control circuit for controlling the amount of light emission per unit area . 2. The R, G, and B signals of an input image are the same for each color.
And a panel in which the ratio of power consumed for each display when displaying the image in monochrome is KR: KG: KB, and the input video signals R, G, and B for a predetermined period are integrated. An integration circuit that outputs each of an R average level, a G average level, and a B average level; and a first circuit that multiplies each of the R average level, the G average level, and the B average level by the KR, KG, and KB, respectively. A second and third multiplying circuit; a circuit for obtaining and outputting a power consumption prediction signal based on an output signal of the first, second and third multiplication circuits; A controller that outputs a multiplication coefficient whose power consumption is limited within a predetermined range based on a value of the power consumption prediction signal; and a delay unit that delays the input video signals R, G, and B, and outputs the delayed video signals DR, DG, and DB. Output delay Fourth, fifth, image display device and a multiplier circuit of the sixth to each multiplies the road, the delayed video signal DR, DG, and DB and the multiplication factor. 3. An image display device which divides one field of a video signal into a plurality of weighted sub-fields, and displays a video of the sub-field in a temporally superimposed manner to perform gradation display, R, G, and B signals of the input video are the same for each color.
A panel in which the ratio of power consumed for each display when displaying is KR: KG: KB, and input video signals R, G, and B for at least one field are respectively integrated to obtain an R average level; An R integration circuit, a G integration circuit that outputs each of the G average level and the B average level,
A B integrator circuit, a first multiplier circuit, a second multiplier circuit, and a third multiplier circuit for multiplying the R average level, the G average level, and the B average level by KR, KG, and KB, respectively. A power consumption prediction circuit for obtaining and outputting a power consumption prediction signal from outputs of the first multiplication circuit, the second multiplication circuit, and the third multiplication circuit; A controller that outputs a light emission pulse control signal for selecting a light emission format in which power consumption is limited within a predetermined range based on the value of the power prediction signal, and delays the input video signals R, G, and B, respectively. A delay circuit that outputs delayed video signals DR, DG, and DB; the light emission pulse control signal and the delayed video signals DR and D
A video signal-subfield associator for inputting G and DB and associating an output signal of a delay circuit with a subfield configuration of a light emission format corresponding to the light emission pulse control signal; And scan, maintain, and maintain a subfield configuration of the light emission format based on the light emission pulse control signal.
An image display device comprising: a subfield pulse generating unit that generates a pulse for erasing or the like. 4. An image display device which divides one field of a video signal into a plurality of weighted sub-fields and displays a video of the sub-field in a temporally superimposed manner to perform gradation display, R, G, and B signals of the input video are the same for each color.
A panel in which the ratio of power consumed for each display when displayed is KR: KG: KB, and at least one field of the input video signals R, G,
B is integrated and R average level, G average level, B
An R integration circuit, a G integration circuit, and a B integration circuit that respectively output an average level; and a first multiplication that multiplies each of the R average level, the G average level, and the B average level by KR, KG, and KB, respectively. Circuit, a second multiplication circuit, a third multiplication circuit, and a power consumption prediction signal which is obtained from an output of the first multiplication circuit, the second multiplication circuit, and the third multiplication circuit, and is output. A circuit for inputting the power consumption prediction signal, and a light emission pulse control signal for selecting a light emission format in which power consumption is limited within a predetermined range based on a value of the power consumption prediction signal; A controller that outputs a multiplication coefficient that corrects a gradation so that the luminance becomes equal at each point; and a delay circuit that delays the input video signals R, G, and B and outputs delayed video signals DR, DG, and DB, respectively. A fourth, a fifth, and a sixth multiplying circuit for multiplying the delayed video signals DR, DG, and DB by the multiplying coefficients, respectively; and the light-emitting pulse control signal and the fourth, fifth, and sixth multiplying circuits. And an output signal of the circuit, and outputs the light emission pulse control signal.
The subfield configuration of the corresponding light emission format includes the fourth,
A video signal-subfield associator for associating output signals of the fifth and sixth multiplier circuits; and a scanning / maintenance in a subfield configuration of a light emission format based on the light emission pulse control signal, which receives the light emission pulse control signal.・
An image display device comprising: a subfield pulse generating unit that generates a pulse for erasing or the like.