JP5262896B2 - Display method of plasma display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To maintain white balance irrespective of the frequency and intensity of light emission. <P>SOLUTION: A display device for displaying colors by controlling the frequency or intensity of light emission correspondingly to a plurality of input primary color image signals (R, G and B) includes a means 3 for detecting the frequency or intensity of light emission and means 2, 11, 12 and 13 for correcting white balance by adjusting amplitudes of the plurality of primary color image signals in accordance with the detected frequency or intensity of light emission. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to a display device that performs color display by controlling the number or intensity of light emission corresponding to a plurality of input primary color video signals, and in particular, controls the number of light emission of phosphors of three primary colors of red, green, and blue. The present invention relates to a white balance correction technique in a plasma display device that performs color display.

  In recent years, various display devices have been researched and developed, and plasma display devices (PDPs (Plasma Display Panels)) have been developed as flat display devices with large screens that can clearly display characters and images. ) Is attracting attention. This plasma display device performs display with phosphors of the three primary colors of red, green and blue. For example, in order to limit power consumption, the display rate of images (average luminance level: APL (Average Picture Level)) is used. Accordingly, the number of times of light emission (number of times of sustain light emission) is controlled. By the way, each phosphor does not have a constant luminance ratio with respect to the number of times of light emission. Therefore, for example, even if white balance is adjusted at a predetermined number of times of light emission, the white balance is also shifted when the number of times of light emission is changed. It was. The problem of this white balance shift is not only a plasma display device, but also a display device using an EL element (electroluminescence element), an FED (Field Emission Display), an LED (Light Emitting Diode) display, and a CRT (CRT). In various display devices such as Cathode Ray Tube), it is caused by the change in the number of times of light emission or intensity. Therefore, in a display device that performs color display by controlling the number of times or intensity of light emission corresponding to a plurality of input primary color video signals, it is desired to maintain white balance regardless of the number of times of light emission or intensity.

  As described above, the present invention can be applied not only to a plasma display device but also to various display devices such as a display device using an EL element and FED and CRT. In the following description, red, green and A plasma display device will be mainly described as an example of a display device having different afterglow characteristics among the phosphors of the three primary colors of blue.

  FIG. 1 is a block diagram schematically showing an example of a surface discharge AC drive type plasma display device. In FIG. 1, reference numeral 10 is a display panel, 11 is an address electrode, 12 is a scan / sustain electrode, 13 is a sustain electrode, 14 is an address drive circuit, 15 is a scan / sustain pulse output circuit, 16 is a sustain pulse output circuit, Reference numeral 17 denotes a drive control circuit, 18 denotes a signal processing circuit, and 19 denotes a partition wall.

  As shown in FIG. 1, the plasma display device includes a display panel 10 having address electrodes 11, scan / sustain electrodes 12, sustain electrodes 13, and barrier ribs 19, an address driving circuit 14 for driving the address electrodes 11, Scan / sustain pulse output circuit 15 for driving scan / sustain electrode 12, sustain pulse output circuit 16 for driving sustain electrode, drive control circuit 17 for controlling these output circuits, and processing of input signals And a signal processing circuit 18 for performing the above.

  Here, the display panel 10 is provided with an address electrode 11 on one of two opposing glass plates and a scan / sustain electrode 12 and a sustain electrode 13 on the other. And the space between these glass plates is partitioned by the partition walls 19, and each partitioned space constitutes a discharge cell.

  For example, a rare gas such as He—Xe or Ne—Xe is sealed in the discharge cell. When a voltage is applied to the scan / sustain electrode 12 and the sustain electrode 13, discharge occurs and ultraviolet rays are generated. In addition, each discharge cell is coated with a phosphor that emits red, green, or blue light, and the phosphor is excited by the ultraviolet rays generated as described above, depending on the phosphor. Emits colored light. A color image can be displayed by using this light emission and selecting a discharge cell of a desired color according to the video signal.

  Note that the drive control circuit 17 displays video through the scan / sustain pulse output circuit 15 and the sustain pulse output circuit 16 in accordance with the image display rate (or display current) based on the video signals (three primary color video signals R, G, and B). The number of times of signal emission is controlled so that the power consumption does not exceed a predetermined value.

  FIG. 2 is a diagram for explaining an example of a driving sequence in the plasma display device of FIG. 1, for explaining a time-division driving method (hereinafter referred to as a subfield method) using the light emission principle described above. is there.

  In the subfield method, one frame is divided into a plurality of subfields (SF1 to SF4) weighted according to the difference in the number of times of light emission, and gradation is determined by selecting a subfield corresponding to the amplitude of the signal there for each pixel. Is a way of expressing.

  The driving sequence by the subfield method shown in FIG. 2 shows an example in which one frame is divided into four subfields SF1 to SF4 and 16 gradations are displayed. The scanning period T1 of each subfield is a period for selecting a discharge cell (hereinafter referred to as a light emitting cell) that emits light in the subfield, and the discharge sustaining period T2 is a period for selecting the selected light emitting cell. This is the period during which light is emitted.

  The discharge sustain period T2 of the subfields SF1 to SF4 represents the time during which the selected cell emits light, and each is weighted to the number of times of light emission at a ratio of 8: 4: 2: 1. Then, by arbitrarily selecting any one of these subfields SF1 to SF4 according to the video signal level, it is possible to display 2 4 = 16 gradations. In order to increase the number of gradations, the number of subfields may be increased. For example, when the number of subfields is 8, display of 2 8 = 256 gradations is possible. Note that the luminance level of each subfield is controlled by the number of times of sustain light emission (number of light emission times).

  FIG. 3 is a diagram for explaining the relationship between the display rate (APL), the number of times of light emission, and the power consumption in the plasma display device of FIG. 1, and FIG. 3 (a) shows the relationship between the number of times of light emission of the light emitting cell and the power consumption. 3 (b) shows the relationship between the display rate (APL) of the image (display panel) and the number of times of light emission, and FIG. 3 (c) shows the relationship between the display rate of the image by the video signal and the power consumption. Yes.

  As shown in FIG. 3A, the power consumption of the plasma display device increases as the number of light emission times of the display cell increases. Therefore, in an actual plasma display device, as shown in FIG. 3B, in order to keep the power consumption below a predetermined value, the image display rate (APL) is high, that is, the entire screen. When an image (video signal) that emits light is displayed, the number of times of light emission as a whole frame is limited while maintaining the weighting ratio of the number of times of light emission of each subfield described above. .

  That is, in FIG. 3B, when the number of display gradations is 256 gradations, for example, the number of times of light emission at point A is a weight of 512: 256: 128: 64: 32: 16: 8: 4. If it is, it is 1020 times, and if the number of times of light emission at point B is weighted 128: 64: 32: 16: 8: 4: 2: 1, the number of times of light emission is limited to 255 times. That is, as shown in FIG. 3C, the power consumption of the plasma display device is suppressed even when the APL increases by limiting the number of times of light emission according to the APL.

  FIG. 4 is a block diagram showing an example of a conventional white balance adjustment circuit. In FIG. 4, reference numerals 11 to 13 are multipliers, 2 is a microcomputer, and 41 to 43 are γ correction circuits.

  As shown in FIG. 4, the conventional white balance adjustment circuit performs gamma correction on input video signals R, G and B by gamma correction circuits 41 to 43, respectively, and then microcomputers 13 to 13 respectively. 2 is multiplied by multiplication coefficients (amplitude coefficients) Kr, Kg, and Kb. That is, the microcomputer 2 supplies the multipliers 11 to 13 with coefficients Kr, Kg, and Kb for the video signals R, G, and B of the respective colors in order to adjust the white balance by changing the luminance ratio of red, green, and blue. Here, the coefficients Kr, Kg, and Kb may be the same or different depending on the video signals R, G, and B of the respective colors. That is, the conventional white balance adjustment circuit gives the coefficients Kr, Kg, and Kb from the microcomputer 2 to the multipliers 11 to 13 and controls the signal amplitude of the video signals R, G, and B of the respective colors, thereby controlling the white balance. Make adjustments.

  Here, in the conventional white balance adjustment circuit, in order to adjust the white balance, for example, a predetermined adjustment pattern (for example, a window pattern) is displayed at a predetermined number of times of light emission to obtain a desired white balance. As shown, the signal amplitudes of the video signals R, G, and B of the respective colors are adjusted. That is, for example, before factory shipment, the white balance is adjusted for each set (plasma display device), but a fixed adjustment pattern is displayed at a predetermined number of times of light emission, and in that state, the coefficient Kr, Kg and Kb are set.

  As described above, in the conventional white balance adjustment circuit, the white balance is adjusted by displaying a certain adjustment pattern at a predetermined APL (that is, a predetermined number of times of light emission). Balance may be off.

  FIG. 5 is a diagram showing the relationship between the number of times of light emission and the luminance of the phosphors of the three primary colors of red, green and blue. FIG. 5 (a) shows the relationship between the number of times of light emission and the luminance, and FIG. Indicates unit luminance characteristics due to a decrease in energy conversion efficiency.

  As shown in FIG. 5A, the luminances of the three primary colors of red, green and blue become saturated as the number of times of light emission increases. This is because the afterglow characteristics of the phosphors of red, green and blue, in other words, the energy conversion efficiency of the phosphor with respect to excitation by ultraviolet rays decreases as the number of times of light emission increases as shown in FIG. It happens. In FIG. 5B, the vertical axis indicates the value obtained by normalizing the luminance per unit light emission with the light emission luminance per unit when the energy conversion efficiency is the highest, and the horizontal axis indicates the number of times of light emission. ing.

  Here, in FIG. 5A and FIG. 5B, for example, if the white balance is adjusted at point A where the number of times of light emission is large, the white balance value at that time is red, green and blue at point A. Determined by luminance ratio. However, when displaying a video signal with a high APL, as described above, the number of times of light emission is reduced in order to keep power consumption within a predetermined value.

  Therefore, in the case of point B where the number of times of light emission is small, as shown in FIG. 5 (b), the energy conversion efficiency of the phosphor with respect to excitation by ultraviolet light increases, so the rate of decrease in energy conversion efficiency is green> red> blue. If this is the case, the brightness is relatively higher in the order of green> red> blue than the point A. That is, since the luminance ratio of red, green, and blue at point B is different from the adjustment value at point A, there is a difference in white balance between point A and point B.

  Conversely, when displaying a video signal whose APL is lower than that at the time of white balance adjustment, the number of times of light emission may be increased. Therefore, the energy conversion efficiency is further reduced, and red is emitted as in the case where the number of times of light emission is small. The brightness ratio of green and blue is different and the white balance value is different.

  The present invention has been made in view of the above-described problems in the conventional white balance adjustment technology, and provides a white balance correction circuit, a correction method, and a display device capable of maintaining white balance regardless of the number of times of light emission and the intensity. .

In one embodiment of the present invention , for example, the technical idea described in the claims may be used.

  According to the present invention, white balance can be maintained regardless of the number of times of light emission and intensity.

It is a block diagram which shows roughly an example of a surface discharge alternating current drive type plasma display apparatus. It is a figure for demonstrating an example of the drive sequence in the plasma display apparatus of FIG. It is a figure for demonstrating the relationship between the display rate (APL) in the plasma display apparatus of FIG. 1, the frequency | count of light emission, and power consumption. It is a block diagram which shows an example of the conventional white balance adjustment circuit. It is a figure which shows the relationship between the frequency | count of light emission and the brightness | luminance of each phosphor of the three primary colors of red, green, and blue. 1 is a block diagram showing a first embodiment of a white balance correction circuit according to the present invention. FIG. It is a figure which shows the luminance ratio in each frequency | count of light emission of the phosphor of three primary colors on the basis of blue. It is a figure for demonstrating each multiplication coefficient of the three primary colors of red, green, and blue in the white balance correction circuit of FIG. It is a figure which shows the luminance ratio in each frequency | count of light emission of the phosphor of the three primary colors corrected by the white balance correction circuit of FIG. It is a block diagram which shows an example of the APL detection circuit in the white balance correction circuit of FIG. It is a block diagram which shows 2nd Example of the white balance correction circuit based on this invention. It is a block diagram which shows 3rd Example of the white balance correction circuit based on this invention. It is a block diagram which shows the 4th Example of the white balance correction circuit based on this invention. It is a block diagram which shows the 5th Example of the white balance correction circuit based on this invention. FIG. 6 is a diagram (part 1) illustrating a relationship between a gradation level and the number of light emissions. FIG. 6 is a diagram (part 2) illustrating a relationship between a gradation level and the number of light emissions. It is a figure which shows the relationship between the gradation level and luminance ratio of each phosphor of the three primary colors of red, green, and blue. It is a block diagram which shows the 6th Example of the white balance correction circuit which concerns on this invention. It is a figure for demonstrating each multiplication coefficient of the three primary colors of red, green, and blue in the white balance correction circuit of FIG. It is a figure which shows the luminance ratio in each gradation level of the phosphor of the three primary colors correct | amended by the white balance correction circuit of FIG. It is a figure which shows the luminance characteristic of the phosphor of the three primary colors by the presence or absence of application of the 6th Example of the white balance correction circuit which concerns on this invention.

  Embodiments of a white balance correction circuit, a correction method, and a display device according to the present invention will be described below in detail with reference to the drawings. In the following description of the present embodiment, a plasma display device is taken as an example. However, the present invention is not limited to a plasma display device, but various displays such as a display device using an EL element, an FED, an LED display, and a CRT. It can be applied to the device.

  FIG. 6 is a block diagram showing a first embodiment of the white balance correction circuit according to the present invention, and FIG. 7 is a diagram showing the luminance ratio of each of the three primary color phosphors with respect to the number of times of light emission with reference to blue.

  In FIG. 6, reference numerals 11 to 13 are multipliers, 2 is a microcomputer (microcomputer), and 3 is an APL detection circuit (average luminance level (display rate) detection circuit). Reference symbols Kr, Kg, and Kb are multiplication coefficients (amplitude coefficients) for input video signals (digital three primary color video signals) R, G, and B, respectively.

  As shown in FIG. 6, the white balance adjustment circuit of the first embodiment includes multipliers 11 to 13 that input video signals R, G, and B according to multiplication coefficients Kr, Kg, and Kb given from the microcomputer 2. Adjust the white balance by adjusting the amplitude using. The microcomputer 2 sets the number of times of light emission according to the APL (average luminance level: display rate) obtained from the APL detection circuit 3. Further, the microcomputer 2 calculates the increase / decrease rate of the luminance ratio of R, G, B (red, green and blue) due to the increase / decrease of the energy conversion efficiency from the number of times of light emission, and reversely corrects the increase / decrease rate to red, green and blue In the meantime, multiplication coefficients Kr, Kg, and Kb are calculated and supplied to the multipliers 11 to 13 so that the luminance ratio is constant.

  For example, white balance adjustment is performed at the maximum number of times of light emission, and correction is performed for each number of times of light emission, and blue phosphor has the shortest afterglow characteristics (that is, energy conversion efficiency does not decrease). 7 is assumed to be a characteristic as shown in FIG. 7 with respect to the luminance ratio of red, green, and blue at each light emission number. At this time, assuming that the luminance ratio based on blue is α, the luminance ratio at the time of zero light emission is α0, the light emission number is N, the maximum light emission number is Nm, and the change of the green luminance ratio is approximated by a linear expression, α = The equation ((1−α0) / Nm) · N + α0 is obtained.

  In order to make the white balance constant at each number of times of light emission, it is only necessary to reversely correct the increase / decrease rate of the luminance ratio, so the multiplication coefficient Kg can be calculated as the reciprocal Kg = 1 / α of the luminance ratio α. Further, the same calculation can be made for red (R). Of course, the same applies even if the reference color is changed. If the multiplication coefficients Kr, Kg, and Kb are calculated by the microcomputer 2 in this way and set in the multiplier 1 to adjust the signal amplitude, the luminance ratio can be kept constant at each light emission number, and the white balance Can be kept constant. Here, the approximation is performed using the linear expression, but more accurate correction can be performed by performing the approximation using a higher-order expression.

  In this embodiment, first, in order to grasp the characteristics of the phosphor, the relationship between the number of times of light emission and the luminance is measured in advance, and for example, the relationship between the number of times of light emission and the luminance as shown in FIG. Further, each phosphor (red, green and blue) is normalized from the measured data on the basis of the phosphor having the most linear characteristics (for example, blue), and the luminance ratio at each light emission number is calculated.

  That is, for example, as shown in FIG. 7, the luminance ratio of each phosphor with respect to blue is calculated using blue as a reference. Here, the red, green, and blue luminances at point A are normalized as Lar, Lag, and Lab, and the luminances at each light emission count are normalized as Lr, Lg, and Lb, respectively. Note that FIG. 7 (solid line: red, green, blue) depicts values calculated based on the following equations.

Luminance ratio of red to blue = (Lr / Lar) / (Lb / Lab)
Luminance ratio of green to blue = (Lg / Lag) / (Lb / Lab)

  By the way, in order to suppress the fluctuation of the white balance due to the number of times of light emission, it is sufficient that the luminance ratio is always constant. Therefore, the change of the luminance ratio is approximated by a linear expression as shown in FIG. White balance is corrected by multiplying the video signal by the reciprocal (multiplication coefficient K). That is, the multiplication coefficient K is calculated by the equation: K = 1 / α = Nm / (N + α0 (Nm−N)).

  FIG. 8 is a diagram for explaining the multiplication coefficients of the three primary colors of red, green, and blue in the white balance correction circuit of FIG. 6, and from the equation K = 1 / α = Nm / (N + α0 (Nm−N)). It is drawn by calculating red, green and blue multiplication coefficients Kr, Kg and Kb. Reference symbol N indicates the number of times of light emission, Nm indicates the maximum number of times of light emission, and α0 indicates the luminance ratio at the time of the minimum number of times of light emission.

  Here, the linear expression shown in FIG. 7 is determined by the phosphor, and is determined when the phosphor is determined. Accordingly, an arithmetic expression (see FIG. 8) for calculating the reciprocal number is programmed in the microcomputer 2 in advance, and the multiplication coefficient for each number of times of light emission is calculated using the program.

  FIG. 9 is a diagram showing the result of multiplication according to the multiplication coefficient calculated by the microcomputer 2, that is, the luminance ratio at each light emission number of the three primary color phosphors corrected by the white balance correction circuit of FIG. As is clear from FIG. 9, the phosphors of red, green, and blue (the three primary colors) can maintain a constant luminance ratio regardless of the number of times of light emission, and thus maintain a white balance regardless of the number of times of light emission. You can see that

Specifically, for example, the luminance of green and blue at the maximum number of emissions are the 200 cd / m ² and 80 cd / m ^2, it is assumed the luminance of the minimum number of emissions and, respectively 60 cd / m ² and 20 cd / m ^2.

At this time, the luminance ratio of blue and green at the maximum number of flashes is
Blue: Green = 80: 200 = 1: 2.5
It becomes.

The luminance ratio of blue and green at the minimum number of flashes is
Blue: Green = 20: 60 = 1: 3
It becomes.

  Therefore, the luminance ratio of green to blue is. Since it is 1.2 times (3 / 2.5 times) and this is α0, the multiplication coefficient K which is the reciprocal thereof is

K = 1 / α0 = 1 / 1.2 = 0.83
It becomes. In other words, the green video signal (G) is corrected by multiplying its signal amplitude by 0.83. The same applies to the red video signal (R). Therefore, it is possible to maintain the white balance regardless of the number of times of light emission by calculating a multiplication coefficient for each number of times of light emission using the above approximate expression and multiplying it by the video signal.

  FIG. 10 is a block diagram showing an example of the APL detection circuit 3 in the white balance correction circuit of FIG. In FIG. 10, reference numerals 31 and 33 indicate adders, and 32 and 34 indicate registers.

  As shown in FIG. 10, for example, the input 8-bit video signal is added by the adder 31, and the video output (luminance) for each line corresponding to the horizontal synchronization signal H is stored in the register 32. Further, the output for each line from the register 32 is added by the adder 33, and the video output for each screen corresponding to the vertical synchronization signal V is stored in the register 34. Then, the average luminance level (display rate) of the image to be displayed is calculated. In addition, this APL detection circuit 3 applies what is used in order to control the frequency | count of light emission according to APL (display rate), for example, in order to make the power consumption of a display apparatus smaller than a predetermined value. Various other configurations are possible.

  FIG. 11 is a block diagram showing a second embodiment of the white balance correction circuit according to the present invention. In FIG. 11, reference numeral 5 denotes a current detection circuit, 6 denotes a panel drive circuit, and 7 denotes a light emission number control circuit.

  As shown in FIG. 11, in the second embodiment of the present invention, a current detection circuit 5 is provided in place of the APL detection circuit 3 in the first embodiment shown in FIG. The consumption current (display current) of the panel drive circuit 6 is detected, that is, the display current corresponding to the display rate of the first embodiment is detected, and the microcomputer 2 calculates the multiplication coefficient accordingly. In the second embodiment, the microcomputer 2 receives the output from the current detection circuit 5 and controls the number of times of light emission of each phosphor. For example, the power consumption of the display device becomes smaller than a predetermined value. As described above, the number of times of light emission is controlled via the light emission number control circuit 7.

  That is, the current detection circuit 5 detects the current consumed by the panel drive circuit 6, converts it into a voltage value, and feeds it back to the microcomputer 2. The microcomputer 2 determines the number of times of light emission from the light emission number control circuit 7 according to the voltage value. Reading and setting of the number of times of light emission are performed. Then, the microcomputer 2 calculates the change in the luminance ratio according to the increase / decrease rate of the energy conversion efficiency according to the set number of times of light emission, and the multiplication coefficient K (Kr, Kr, so as to keep the luminance ratio of red, green and blue constant. Kg, Kb) is calculated. The coefficients Kr, Kg, and Kb are multiplied by the video signals R, G, and B by the multipliers 11, 12, and 13, and the signal amplitude is adjusted to keep the white balance constant.

  According to the second embodiment, for example, the present invention can be widely applied to display devices that do not have an APL detection circuit. Specifically, the present invention can be applied to a CRT or the like.

  FIG. 12 is a block diagram showing a third embodiment of the white balance correction circuit according to the present invention. In FIG. 12, reference numeral 8 indicates an address decoder, and 9 indicates a storage device (ROM: Read Only Memory).

  As shown in FIG. 12, the third embodiment is provided with an address decoder 8 and a ROM 9 instead of the microcomputer 2 in the first embodiment of FIG. Here, the ROM 9 stores multiplication coefficients Kr, Kg, Kb for each video signal corresponding to each APL (display ratio), and outputs a multiplication coefficient corresponding to the APL detected by the APL detection circuit 3. It is supposed to be.

  That is, the APL detection circuit 3 detects the APL of the input video signal and supplies it to the address decoder 8, and the address decoder 8 generates the address of the ROM 9 in which the multiplication coefficient corresponding to the detected APL is stored. . Here, the ROM 9 stores in advance each APL, that is, multiplication coefficients Kr, Kg, Kb for correcting a change in luminance ratio due to increase / decrease in energy conversion efficiency corresponding to each number of times of light emission. The corresponding multiplication coefficient is output in accordance with the address of, and set in each multiplier 11, 12, 13.

  According to the third embodiment, for example, when the number of times of light emission and each multiplication coefficient Kr, Kg, Kb cannot be approximated by a simple equation (for example, the energy conversion efficiency of each phosphor changes in a complex manner depending on the number of times of light emission. However, the white balance can be sufficiently corrected.

  Also in the third embodiment, as in the second embodiment described above, a current detection circuit 5 is provided instead of the APL detection circuit 3, and a display current (consumption current of the panel drive circuit 6) is used instead of the display rate. It is also possible to perform the same control by detecting.

  FIG. 13 is a block diagram showing a fourth embodiment of the white balance correction circuit according to the present invention. In FIG. 13, reference numeral 80 is an address decoder, and 91, 92, and 93 are ROMs (storage devices).

  As shown in FIG. 13, in the fourth embodiment, the ROM 9 and the multipliers 11 to 13 in the third embodiment described above are replaced with ROMs 91 to 93, and the APL of the input video signal is converted into an APL detection circuit. 3, and the detected value is converted into an address for each of the ROMs 91 to 93 by the address decoder 80. In each ROM 91, 92, 93, in order to correct the luminance ratio change due to the increase / decrease in energy conversion efficiency corresponding to each APL, that is, the number of times of light emission, coefficients in the video signals (R, G, B) are respectively stored. Stores the multiplied data. Then, for example, data stored in each ROM 91, 92, 93 is read out using the address supplied from the address decoder 80 as the upper bit address and the video signal as the lower bit address, thereby adjusting the video amplitude. Thus, the luminance ratio between red, green and blue is kept constant.

  According to the fourth embodiment, as in the third embodiment described above, even when the number of times of light emission and each multiplication coefficient Kr, Kg, Kb cannot be approximated by a simple expression, the white balance is sufficiently corrected. It becomes possible to do. In the fourth embodiment, the current detection circuit 5 is provided in place of the APL detection circuit 3, and the same control can be performed by detecting the display current instead of the display rate.

  FIG. 14 is a block diagram showing a fifth embodiment of the white balance correction circuit according to the present invention.

  As shown in FIG. 14, a luminance adjustment input from the outside (for example, a user) is given to the microcomputer 2, and the luminance of the display image is changed via the light emission control circuit 7 and the panel drive circuit 6 in accordance with the luminance adjustment input. It is set up. At this time, in the fifth embodiment, the microcomputer 2 calculates the change in the luminance ratio according to the increase / decrease rate of the energy conversion efficiency according to the number of times of light emission from the number of times of light emission according to the given luminance adjustment input, The multiplication coefficient K (Kr, Kg, Kb) is calculated so as to keep the green and blue luminance ratio constant. The coefficients Kr, Kg, and Kb are multiplied by the video signals R, G, and B by the multipliers 11, 12, and 13, and the signal amplitude is adjusted to keep the white balance constant.

  The white balance correction by external luminance adjustment input in the fifth embodiment is independent of the white balance correction in the first to fourth embodiments performed by detecting the display rate or the display current, for example. The white balance correction circuit can be configured by arbitrarily combining them. That is, for example, when the fifth embodiment and the second embodiment shown in FIG. 11 are applied in combination, the coefficients Kr, Kg, Kb output from the microcomputer 2 are detected by the current detection circuit 5. A value that keeps the luminance ratio of red, green, and blue constant with respect to the sum of the current consumption (display current) of the panel drive circuit 6 and the change of the luminance ratio due to the luminance adjustment input from the outside. It will be said.

15 and 16 are diagrams showing the relationship between the gradation level and the number of times of light emission.
As shown in FIGS. 15 and 16, each gradation level A to F of a plurality of input primary color video signals (for example, three primary color video signals R, G, and B) is set to different sets of light emission times (processing P1 to P5). A method of displaying by (...) is known. As in the above-described embodiments, the display rate or display current of an image by an input video signal is detected, and, for example, the power consumption of the entire display device is predetermined by the detected display rate or display current. In order not to exceed the value, drive control is performed to reduce the number of times of light emission while maintaining the gradation levels A to F.

  That is, when the reference symbol F in FIGS. 15 and 16 is set to the 300 gradation level and C is set to the 150 gradation level, for example, the image display rate by the input video signal is high and the power consumption is sufficiently reduced to reduce the power consumption. When it is necessary to keep the gradation levels F and C below, the Ff (for example, sustaining light emission pulse: 150 times) and Cf in the driving process P1 with a small driving current (the total number of times of light emission) is reduced. (For example, sustain light emission pulse: 75 times). On the other hand, for example, when the display rate of the image by the input video signal is extremely low, each gradation level F and C is set to Ff × 5 (in the driving process P5 with a large driving current (a large number of overall light emission times). For example, display is performed by sustain light emission pulse: 750 times and Cf × 5 (for example, sustain light emission pulse: 375 times). The same processing is performed for other gradations (A, B,...). Accordingly, the display rate (or display current) of an image by a plurality of primary color video signals is detected, and the number of times or the intensity of the emission of the plurality of primary color video signals is controlled according to the detected display rate (or display current). become.

  By the way, as described above, in the conventional white balance adjustment circuit, in order to adjust the white balance, for example, a certain adjustment pattern (for example, a window pattern) is displayed at a predetermined gradation level. The signal amplitude of each color video signal R, G, B is adjusted so that the white balance can be obtained. However, when a certain adjustment pattern is displayed at a predetermined gradation level to adjust the white balance (for example, adjustment once before factory shipment), different gradation levels (input gradation levels) are used. Was out of balance.

  FIG. 17 is a diagram showing the relationship between the gradation level and the luminance ratio of the phosphors of the three primary colors of red, green and blue. The luminance ratio of each color at the maximum gradation level is shown with reference to blue. FIG. 18 is a block diagram showing a sixth embodiment of the white balance correction circuit according to the present invention. FIG. 19 is a diagram for explaining the multiplication factors of the three primary colors red, green and blue in the white balance correction circuit of FIG. FIG. 20 and FIG. 20 are diagrams showing luminance ratios at the respective gradation levels of the phosphors of the three primary colors corrected by the white balance correction circuit of FIG.

  As is clear from comparison between FIGS. 7 to 9 and FIGS. 17, 19 and 20, the respective gradation levels (input gradation levels) and luminance ratios of the phosphors of the three primary colors in the sixth embodiment. The relationship with α can be considered, for example, corresponding to the number of times of light emission and the luminance ratio in the first embodiment.

  In FIG. 18, reference numerals 11 to 13 are multipliers, 2 is a microcomputer, 41 to 43 are γ correction circuits, 101 is an input gradation level detector, 102 is an address decoder, 103 is a storage device (ROM), and 141 Reference numerals ˜143 denote multipliers (output gradation level correction units). The multipliers 11 to 13, the microcomputer 2, and the γ correction circuits 41 to 43 are the same as those in the conventional example of FIG. 4 described above, and a description thereof will be omitted.

  As shown in FIG. 18, the white balance adjustment circuit of the sixth embodiment detects (recognizes) each input gradation level in the input video signals R, G, and B by the input gradation level detection unit 101. Accordingly, correction coefficients Lr, Lg, and Lb are output via the address decoder 102 and the storage device 103. Here, each correction coefficient L has a relationship of L = 1 / α, that is, a relationship of Lr = 1 / αr, Lg = 1 / αg, and Lb = 1 / αb.

  Each of the multipliers 141 and 142 (143) calculates an output gradation level by performing correction according to the following arithmetic expression using the input correction coefficients Lr and Lg (Lb). Here, X is an input gradation level, Y is an output gradation level, and β is a maximum input gradation level.

Y (X) = L + (1-L) · (X / β)
When the blue video signal is used as a standard (standardization), Lb = 1 / αb = 1/1 = 1, so that correction of the input gradation level in the blue video signal is unnecessary. It is not necessary to provide the multiplier 143 for the blue video signal.

  In the sixth embodiment shown in FIG. 18, the correction coefficient L corresponding to the detected input gradation level is output from the storage device 103. For example, the input gradation level is adjusted using a microcomputer. A corresponding correction coefficient L may be calculated and supplied to the multipliers (output gradation level correction units) 141 to 143. Furthermore, a white balance correction circuit can be configured by using a microcomputer or the like that is also used for white balance correction performed by adjusting the amplitude of each video signal according to the number or intensity of light emission.

  FIG. 21 is a diagram showing luminance characteristics of phosphors of three primary colors depending on whether or not the sixth embodiment of the white balance correction circuit according to the present invention is applied.

  As is apparent from FIG. 21, by applying the white balance correction circuit of the sixth embodiment, for example, the change in white balance due to the respective gradation levels of the phosphors of red, green and blue can be made constant in the luminance ratio. By adjusting so as to maintain the white balance, the white balance can be maintained regardless of the gradation level.

  In the above, each embodiment of the present invention has been described by taking a plasma display device as an example. For example, a color display device (for example, CRT, LED, etc.) using a light emitter having different afterglow characteristics among red, green, and blue. Also in a display or the like, if the number of times of light emission is replaced with light emission luminance (intensity), it is possible to correct the white balance by applying the present invention as it is.

[Appendix] The present invention has the following features.
(Supplementary Note 1) A display device that performs color display by controlling the number of times or intensity of light emission corresponding to a plurality of primary color video signals input,
Means for detecting the number or intensity of light emission;
A display device comprising: means for adjusting white balance by adjusting amplitudes of the plurality of primary color video signals according to the detected number of times of light emission or intensity.

  (Supplementary note 2) In the display device according to supplementary note 1, the means for detecting the number of times of light emission or the intensity detects the number of times of light emission or the intensity from a display rate of an image by the plurality of primary color video signals. apparatus.

  (Supplementary note 3) The display device according to supplementary note 2, wherein the display device further includes means for controlling the number of times of emission or intensity of the plurality of primary color video signals according to the display rate of the image. apparatus.

  (Supplementary note 4) In the display device according to supplementary note 3, the means for correcting the white balance includes a calculation unit and a plurality of multiplication units, and the calculation unit calculates the amplitude coefficient of the plurality of primary color video signals as a display rate of the image. The display device is characterized in that each of the multiplication means multiplies each of the primary color video signals by the calculated amplitude coefficient.

  (Supplementary note 5) In the display device according to supplementary note 3, the means for correcting the white balance includes storage means and a plurality of multiplication means, and the storage means uses the amplitude coefficient of the plurality of primary color video signals as the display rate of the image. Each of the multiplying means multiplies each primary color video signal by the amplitude coefficient output from the storage means.

  (Supplementary note 6) In the display device according to supplementary note 3, the means for correcting the white balance includes a storage unit, and the storage unit converts the primary color video signals having the adjusted amplitudes to the plurality of primary color video signals and the image. A display device that outputs in accordance with the display rate.

  (Supplementary note 7) In the display device according to supplementary note 1, the means for detecting the number of times of light emission or intensity detects the number of times of light emission or intensity from a display current at the time of image display by the plurality of primary color video signals. Display device.

  (Supplementary note 8) In the display device according to supplementary note 7, the display device further includes means for controlling the number of light emission times or the intensity of the plurality of primary color video signals according to the display current at the time of the image display. Display device.

  (Supplementary note 9) In the display device according to supplementary note 8, the means for correcting the white balance includes a calculation unit and a plurality of multiplication units, and the calculation unit calculates amplitude coefficients of the plurality of primary color video signals when the image is displayed. A display device that calculates in accordance with a display current, and wherein each of the multiplying means multiplies each of the primary color video signals by the calculated amplitude coefficient.

  (Supplementary Note 10) In the display device according to supplementary note 8, the means for correcting the white balance includes a storage unit and a plurality of multiplication units, and the storage unit calculates amplitude coefficients of the plurality of primary color video signals at the time of image display. A display device that outputs in accordance with a display current, and wherein each multiplication means multiplies each primary color video signal by the amplitude coefficient outputted from the storage means.

  (Supplementary Note 11) In the display device according to supplementary note 8, the means for correcting the white balance includes a storage unit, and the storage unit converts the primary color video signals having the adjusted amplitudes to the plurality of primary color video signals and the image. A display device that outputs in accordance with a display current at the time of display.

  (Additional remark 12) The display apparatus of Additional remark 1 WHEREIN: The means to detect the said light emission frequency or intensity | strength detects the said light emission frequency or intensity from the brightness | luminance adjustment input from the outside.

  (Supplementary note 13) In the display device according to supplementary note 12, the display device further includes means for controlling the number of emission times or the intensity of the plurality of primary color video signals in accordance with the external luminance adjustment input. Display device.

  (Supplementary note 14) In the display device according to supplementary note 13, the means for correcting the white balance includes a calculation unit and a plurality of multiplication units, and the calculation unit calculates the amplitude coefficient of the plurality of primary color video signals from the external luminance. A display device characterized in that the calculation is performed in accordance with an adjustment input, and each multiplication means multiplies each of the primary color video signals by the calculated amplitude coefficient.

  (Supplementary note 15) In the display device according to supplementary note 13, the means for correcting the white balance includes storage means and a plurality of multiplication means, and the storage means uses the amplitude coefficients of the plurality of primary color video signals as the luminance from the outside. The display device according to claim 1, wherein each of the multiplication means multiplies the primary color video signal by the amplitude coefficient outputted from the storage means.

  (Supplementary Note 16) In the display device according to supplementary note 13, the means for correcting the white balance includes a storage unit, and the storage unit converts the primary color video signals having the adjusted amplitudes to the plurality of primary color video signals and the external signals. A display device that outputs in accordance with a luminance adjustment input from.

(Supplementary Note 17) A display device that performs color display by controlling the number of times or intensity of light emission corresponding to a plurality of input primary color video signals,
The output gradation level of the image by the plurality of primary color video signals is adjusted according to the input gradation level of the image by the plurality of primary color video signals, and the white balance that varies depending on the number of times of emission or the intensity of the plurality of primary color video signals is adjusted. A display device characterized by correcting.

(Supplementary note 18) In the display device according to supplementary note 17, the display device includes:
Means for detecting an input gradation level of an image by the plurality of primary color video signals;
And a means for adjusting white balance by adjusting output gradation levels of the plurality of primary color video signals in accordance with the detected input gradation level.

  (Supplementary note 19) In the display device according to supplementary note 18, the means for correcting the white balance includes a calculation unit and a plurality of correction units, and the calculation unit sets a correction coefficient of a gradation level to the detected input gradation level. The display device is characterized in that each correction means corrects the input gradation level using the calculated correction coefficient.

  (Supplementary note 20) In the display device according to supplementary note 18, the means for correcting the white balance includes a storage means and a plurality of correction means, and the storage means supplies a correction coefficient of a gradation level to the detected input gradation level. And the correction means corrects the input gradation level using the output correction coefficient.

(Appendix 21) In the display device according to any one of appendices 18 to 20, the display device further includes:
Means for detecting a display rate or display current of an image by the plurality of primary color video signals;
And a means for controlling the number of times or the intensity of light emission of the plurality of primary color video signals according to the detected display rate or display current.

  (Supplementary note 22) The display device according to any one of supplementary notes 1 to 21, wherein light emitted by the plurality of primary color video signals is a red, green, and blue primary color phosphor.

  (Supplementary note 23) The display device according to any one of supplementary notes 1 to 21, wherein the display device is a plasma display device.

(Supplementary Note 24) A white balance correction circuit in a display device provided with means for performing color display by controlling the number of times of light emission or intensity corresponding to a plurality of input primary color video signals and detecting the number of times of light emission or intensity. And
A white balance correction circuit, wherein the white balance is corrected by adjusting amplitudes of the plurality of primary color video signals according to the detected number of times of light emission or intensity.

(Supplementary Note 25) In the white balance correction circuit according to Supplementary Note 24, the white balance correction circuit includes:
A calculation means for calculating an amplitude coefficient of the plurality of primary color video signals according to the number of emission times or the intensity;
A plurality of multiplication means for multiplying each primary color video signal by the calculated amplitude coefficient, and adjusting the amplitudes of the plurality of primary color video signals according to the controlled number of times of light emission or intensity; A white balance correction circuit which corrects a white balance which fluctuates according to the number of times or intensity of signal emission.

(Supplementary Note 26) In the white balance correction circuit according to Supplementary Note 24, the white balance correction circuit includes:
Storage means for storing amplitude coefficients of the plurality of primary color video signals, and outputting according to the number of times of light emission or intensity;
A plurality of multiplication means for multiplying each primary color video signal by the calculated amplitude coefficient, and adjusting the amplitudes of the plurality of primary color video signals according to the controlled number of times of light emission or intensity; A white balance correction circuit which corrects a white balance which fluctuates according to the number of times or intensity of signal emission.

(Supplementary note 27) In the white balance correction circuit according to supplementary note 24, the white balance correction circuit includes:
Means for storing the adjusted primary color video signals according to the plurality of primary color video signals and the number of times or intensity of light emission, and controlling the amplitude of the plurality of primary color video signals as the controlled number of times of light emission or intensity. A white balance correction circuit that adjusts according to the above and corrects the white balance that fluctuates depending on the light emission frequency or intensity of the plurality of primary color video signals.

(Supplementary note 28) In the white balance correction circuit according to supplementary note 24, the white balance correction circuit includes:
Means for storing the adjusted primary color video signals according to the plurality of primary color video signals and the number of times or intensity of light emission, and controlling the amplitude of the plurality of primary color video signals as the controlled number of times of light emission or intensity. A white balance correction circuit that adjusts according to the above and corrects the white balance that fluctuates depending on the light emission frequency or intensity of the plurality of primary color video signals.

  (Supplementary note 29) In the white balance correction circuit according to any one of supplementary notes 24 to 28, the means for detecting the number of times of light emission or the intensity may include the number of times of light emission or the intensity based on an image display rate of the plurality of primary color video signals. A white balance correction circuit characterized by detecting an error.

  (Supplementary Note 30) In the white balance correction circuit according to any one of Supplementary Notes 24 to 28, the means for detecting the number of times of light emission or the intensity is based on a display current at the time of image display by the plurality of primary color video signals. Alternatively, a white balance correction circuit that detects intensity.

  (Supplementary Note 31) In the white balance correction circuit according to any one of Supplementary Notes 24 to 28, the means for detecting the number of times of light emission or the intensity may detect the number of times of light emission or the intensity from an external luminance adjustment input. Characteristic white balance correction circuit.

(Supplementary Note 32) In the white balance correction circuit according to any one of Supplementary Notes 24 to 28, the white balance correction circuit includes:
A calculation means for calculating an amplitude coefficient of the plurality of primary color video signals according to the number of emission times or the intensity;
A plurality of multiplication means for multiplying each primary color video signal by the calculated amplitude coefficient, and adjusting the amplitudes of the plurality of primary color video signals according to the controlled number of times of light emission or intensity; A white balance correction circuit which corrects a white balance which fluctuates according to the number of times or intensity of signal emission.

(Supplementary Note 33) A white balance correction circuit in a display device having means for controlling the number of times or intensity of light emission corresponding to a plurality of input primary color video signals to perform color display and detecting the number of times or intensity of light emission. And
The output gradation level of the image by the plurality of primary color video signals is adjusted according to the input gradation level of the image by the plurality of primary color video signals, and the white balance that varies depending on the number of times of emission or the intensity of the plurality of primary color video signals is adjusted. A white balance correction circuit characterized by correcting.

(Supplementary Note 34) In the white balance correction circuit according to Supplementary Note 33, the white balance correction circuit includes:
Means for detecting an input gradation level of an image by the plurality of primary color video signals;
Means for adjusting white balance by adjusting output gradation levels of the plurality of primary color video signals in accordance with the detected input gradation level.

(Supplementary Note 35) In the white balance correction circuit according to Supplementary Note 34, the white balance correction circuit includes:
A calculation means for calculating a correction coefficient of a gradation level according to the detected input gradation level;
A white balance correction circuit comprising a plurality of correction means for correcting an input gradation level using the calculated correction coefficient.

(Supplementary Note 36) In the white balance correction circuit according to Supplementary Note 34, the white balance correction circuit includes:
Storage means for outputting a gradation level correction coefficient in accordance with the detected input gradation level;
A white balance correction circuit comprising a plurality of correction means for correcting an input gradation level using the output correction coefficient.

(Supplementary note 37) In the white balance correction circuit according to any one of supplementary notes 34 to 36, the white balance correction circuit further includes:
Means for detecting a display rate or display current of an image by the plurality of primary color video signals;
A white balance correction circuit comprising: means for controlling the number of times of emission or intensity of the plurality of primary color video signals according to the detected display rate or display current.

  (Supplementary note 38) In the white balance correction circuit according to any one of supplementary notes 24 to 37, light emission by the plurality of primary color video signals is a red, green, and blue primary color phosphor. Correction circuit.

  (Supplementary note 39) The white balance correction circuit according to any one of supplementary notes 24 to 37, wherein the display device is a plasma display device.

(Supplementary Note 40) A white balance correction method in a display device for performing color display by controlling luminance in response to a plurality of primary color video signals input,
A white balance correction method, wherein an amplitude ratio of the plurality of primary color video signals is set in accordance with a luminance of the primary color video signal, and a change in white balance due to the luminance is suppressed.

(Supplementary note 41) A white balance correction method in a display device for performing color display by controlling the number of times of light emission or intensity corresponding to a plurality of input primary color video signals,
Detecting the number of times or intensity of light emission;
A white balance correction method, wherein the white balance is corrected by adjusting the amplitudes of the plurality of primary color video signals according to the detected number of times of light emission or intensity.

  (Additional remark 42) The white balance correction method of Additional remark 41 WHEREIN: The detection of the said light emission frequency or intensity | strength is calculated | required from the display rate of the image by these several primary color video signals, The white balance correction method characterized by the above-mentioned.

  (Supplementary note 43) In the white balance correction method according to supplementary note 42, the white balance correction method further controls the number of emission times or the intensity of the plurality of primary color video signals according to the display rate of the image. White balance correction method.

  (Additional remark 44) The white balance correction method of Additional remark 41 WHEREIN: The detection of the said light emission frequency or intensity | strength is calculated | required from the display current at the time of the image display by these several primary color video signals, The white balance correction characterized by the above-mentioned. Method.

  (Supplementary Note 45) In the white balance correction method of Supplementary Note 44, the white balance correction method further controls the number of times of emission or intensity of the plurality of primary color video signals according to the display current at the time of the image display. White balance correction method characterized by

  (Additional remark 46) The white balance correction method of Additional remark 41 WHEREIN: The detection of the said light emission frequency or intensity | strength is calculated | required from the brightness | luminance adjustment input from the outside, The white balance correction method characterized by the above-mentioned.

  (Supplementary note 47) In the white balance correction method according to supplementary note 46, the white balance correction method further controls the number of times of emission or intensity of the plurality of primary color video signals in accordance with an external luminance adjustment input. White balance correction method characterized by

(Supplementary Note 48) A white balance correction method in a display device for performing color display by controlling the number of times or intensity of light emission corresponding to a plurality of primary color video signals input,
The output gradation level of the image by the plurality of primary color video signals is adjusted according to the input gradation level of the image by the plurality of primary color video signals, and the white balance that varies depending on the number of times of emission or the intensity of the plurality of primary color video signals is adjusted. A white balance correction method characterized by correcting.

(Supplementary Note 49) In the white balance correction method of Supplementary Note 48, the white balance correction method includes:
Detecting an input gradation level of an image by the plurality of primary color video signals;
2. A white balance correction method, wherein output gradation levels of the plurality of primary color video signals are adjusted according to the detected input gradation level.

  (Additional remark 50) In the white balance correction method according to additional remark 48, the white balance correction method further controls the number of times of emission or intensity of the plurality of primary color video signals according to the display rate or display current of the image. A white balance correction method characterized by the above.

(Supplementary Note 51) A white balance correction method in a display device that performs color display by controlling luminance corresponding to a plurality of input primary color video signals,
A white balance correction method, wherein an amplitude ratio of the plurality of primary color video signals is set in accordance with a luminance of the primary color video signal, and a change in white balance due to the luminance is suppressed.

  (Supplementary note 52) The white balance correction method according to supplementary note 51, wherein the luminance of the primary color video signal is defined by the number of times of emission or intensity of the primary color video signal.

  (Additional remark 53) The white balance correction method which applied the white balance correction method of Additional remark 51 or 52, and made it color-display the said several primary color video signal with a light-emitting body.

(Supplementary Note 54) A white balance correction circuit in a display device that performs color display using a plurality of primary color video signals,
Adjusting means for adjusting the amplitude of each primary color video signal;
Storage means for storing a signal amplitude ratio for correcting the amplitude of the plurality of primary color video signals;
Setting means for setting the signal amplitude ratio stored in the storage means in the adjustment means, and setting the amplitude ratio of the plurality of primary color video signals according to the number of times of emission or intensity of the primary color video signal, A white balance correction circuit which corrects white balance which fluctuates depending on the number of times or intensity of light emission of a plurality of primary color video signals.

(Supplementary Note 55) A white balance correction circuit in a display device that performs color display using a plurality of primary color video signals,
Adjusting means for adjusting the amplitude of each primary color video signal;
A computing means for computing an amplitude ratio of each primary color video signal from the number of times of emission or intensity of the plurality of primary color video signals;
Setting means for setting the amplitude ratio calculated from the calculation means in the adjustment means, and setting the amplitude ratio of the plurality of primary color video signals according to the number of times of emission or intensity of the primary color video signal, A white balance correction circuit which corrects a white balance which varies depending on the number of times or intensity of light emitted from a primary color video signal.

1:11, 12, 13 Multiplier 2 Microcomputer 3 APL detection circuit 31, 33 Adder 32, 34 Register 4: 41, 42, 43 Gamma correction circuit 5 Current detection circuit 6 Panel drive circuit 7 Light emission count control circuit 8; 80; 102 Address decoder 9; 91, 92, 93; 103 Storage device (ROM)
DESCRIPTION OF SYMBOLS 10 Display panel 11 Address electrode 12 Scan / sustain electrode 13 Sustain electrode 14 Address drive circuit 15 Scan / sustain pulse output circuit 16 Sustain pulse output circuit 17 Drive control circuit 18 Signal processing circuit 101 Input gradation level detection part 141-143 Output floor Key level correction unit

Claims (3)

The gradation of the primary color video signal that is output according to the gradation level of the input primary color video signal in a plasma display device that receives a plurality of primary color video signals and performs color display by emitting phosphors of the primary colors A display method for changing the level and displaying the primary color video signal,
Detecting the display rate of the input primary color video signals;
Control the number of times of light emission per frame according to the detected display rate,
When the number of times of light emission is changed from a first value to a second value larger than the first value by controlling the number of times of light emission according to the display rate, the influence of luminance saturation characteristics among a plurality of phosphors is affected. The rate of change of the ratio of the output gradation level to the input gradation level of the primary color video signal corresponding to the smallest phosphor is determined by the ratio of the output gradation level to the input gradation level of the primary color video signal corresponding to the other phosphor. Adjust the output gradation level to be relatively smaller than the rate of change,
A display method for a plasma display device, wherein display is performed by a subfield method in accordance with the adjusted output gradation levels of the plurality of primary color video signals.   2. The plasma display according to claim 1, wherein the plurality of primary color phosphors are red, green and blue phosphors, and the phosphor having the smallest influence of the luminance saturation characteristic is a blue phosphor. Device display method.   2. The plasma display according to claim 1, wherein the phosphor having the smallest influence of the luminance saturation characteristic is a phosphor whose luminance is relatively increased as the number of times of light emission is increased as compared with other phosphors. Device display method.

Images