JP5247654B2 - Display characteristic calibration apparatus quantity for calibrating display characteristics, computer program, storage medium, and display characteristic calibration method - Google Patents

Description

The present invention relates to correction of non-linear characteristics with respect to color and luminance displayed on a display surface of a display device, and more specifically, lookup is performed with a correction amount obtained by comparing a measured value obtained from a sensor with a preset target value. The present invention relates to a technique for setting a table.

Conventionally, when an image signal is input to a display device using a display device such as a CRT, LCD, PDP, or electronic paper and the image is displayed, the level of the input image signal and the output level of the display image of the display device, for example, luminance If the input / output relationship (hereinafter referred to as gradation characteristics) is linear as shown in FIG. 10A, the luminance of the display image also changes relative to the level change of the input image signal. However, since the display device or the like has a distorted nonlinear gradation characteristic as shown in FIG. 10- (b) due to various conditions, the brightness of the display image as opposed to the level change of the input image signal is high. I can't get it. In addition, since this non-linear gradation characteristic is different for each color such as red, green, and blue, the same problem occurs in color reproduction. In color management systems that emphasize color reproducibility, etc. A calibration operation (hereinafter referred to as calibration) is performed to make the tone characteristics the target gradation characteristics.

There are two types of calibration: software calibration in which work is completed only with dedicated software, and hardware calibration in which the dedicated software and the display device work together or work alone. Further, some hardware calibrations have two types of modes, a simple mode and a high accuracy mode. In the high-accuracy mode, both the gradation characteristics and color reproducibility are calibrated while measuring the brightness and chromaticity with a sensor installed on the front of the display device. Although measured by a sensor, actual calibration is only set using predetermined setting information. FIG. 11 shows a block diagram of a display device that realizes hardware calibration having such a high accuracy mode and a simple mode. The pre-stage LUTs 17a, 17b, and 17c and the post-stage LUTs 12a, 12b, and 12c indicate LUTs (look-up tables) for converting gradation characteristics. The LUT is a conversion unit having a memory function that, when a signal of a certain level is input, outputs a level previously associated with the level. A matrix 13 indicates a color conversion unit that adjusts each color distribution of the input image signal by arithmetic processing to obtain a target chromaticity.

The processing in the high accuracy mode will be described in detail. In this mode, the rear-stage LUTs 12a, 12b, and 12c are always in the through state. The through state refers to a state in which the level of the input signal to the subsequent LUTs 12a, 12b, and 12c is associated with the level of the output signal at 1: 1. Or you may make it output by bypassing back | latter stage LUT12a, 12b, 12c. The upstream LUTs 17a, 17b, 17c and the matrix 13 are also set to the through state, and the luminance and chromaticity output from the display panel 11 of the display device 10 in this state are measured by the sensor 30. The brightness with respect to the actually measured input level, that is, the gradation characteristic, is compared with a preset target gradation characteristic, and the preceding LUTs 17a, 17b, and 17c are set so as to eliminate the difference. FIG. 12 shows a schematic diagram of the settings of the pre-stage LUTs 17a, 17b, and 17c. The horizontal axis indicates the level of the input image signals Ri, Gi, Bi to the display device 10, and the vertical axis indicates the luminance value from the display panel 11. The dotted curve in FIG. 12 indicates the target gradation characteristic, and the solid curve indicates the actually measured gradation characteristic, that is, the gradation characteristic unique to the display device 10. The input levels stored on the input side of the previous LUTs 17a, 17b, and 17c are indicated by white circles. For convenience, only nine points are shown in FIG. 12, but the values actually stored on the input side of the previous LUTs 17a, 17b, and 17c are finer. As shown in the figure, when the input level is 110, the target output level is 170 [cd / m 2]. However, since the gradation characteristic inherent to the display device is distorted, it is actually indicated by a black square in FIG. Only 55 [cd / m 2] is output from the display panel 11. Since 170 [cd / m2] can be output with the actually measured gradation characteristics when the input level is 220, 133 [cd] is obtained by associating the output level 220 with the input level 85 in the preceding LUTs 17a, 17b, and 17c. / M2] can be ensured. Similarly, for other input levels, target gradation characteristics can be obtained by associating output levels as indicated by arrows in FIG.

After the setting of the front-stage LUTs 17a, 17b, and 17c, the display chromaticity of the display panel 11 is measured by the sensor 30 in a state where the correction processes of the front-stage LUTs 17a, 17b, and 17c are performed. If the measurement result deviates from the preset target chromaticity, the matrix 13 is set so as to eliminate the difference. The correction process in the matrix 13 is performed by a matrix operation as shown below.
In the formula, Rio, Gio, and Bio are input levels to the matrix 13, and Rm, Gm, and Bm are output levels that the matrix 13 outputs. The difference between the measured chromaticity and the target chromaticity is eliminated while changing Rgain, Ggain, and Bgain in the matrix. Note that the denominator 255 of Rgain, Ggain, and Bgain is the maximum input level. As described above, the matrix is not limited to a value containing only the diagonal component, but may include a value in the non-diagonal component. The calibration work in the high-accuracy mode ends when the settings of the pre-stage LUTs 17a, 17b, and 17c and the matrix 13 are completed. Since the pre-stage LUTs 17a, 17b, and 17c and the matrix 13 are set while being measured by the sensor 30, some work time is required, but it is possible to accurately approximate the target gradation characteristics and chromaticity.

On the other hand, in the simple mode calibration, as in the high accuracy mode, first, the front-stage LUTs 17a, 17b, 17c, the matrix 13, and the rear-stage LUTs 12a, 12b, 12c are set to the through state, and the gradation characteristics of the display panel 11 are measured by the sensor 30. The actually measured gradation characteristics are compared with preset gradation characteristics, and the subsequent LUTs 12a, 12b, and 12c are set so as to eliminate the difference. In the simple mode, the measurement by the sensor 30 is only this process. Normally, the gradation characteristic set here is a gradation characteristic having a linear characteristic that facilitates calculation, such as a straight line or an exponential curve. Since the combination of the rear-stage LUTs 12a, 12b, and 12c and the display panel 11 provides linear gradation characteristics, the setting of the gradation characteristics in the previous-stage LUTs 17a, 17b, and 17c and the setting of color components in the matrix 13 are linear. It is possible to freely set by calculation taking gradation characteristics into consideration. For example, when an exponential curve with a gamma coefficient of 2.2 is set as a gradation characteristic in the rear stage LUTs 12a, 12b, and 12c and the display panel 11, and an exponential curve with a gamma coefficient of 1.8 is set as the gradation characteristic, the former stage LUT 17a , 17b, 17c are input levels Ri, Gi, Bi, and output levels associated with the input levels are Ri ^{1.8 / 2.2} , Gi ^{1.8 / 2.2} , and Bi ^{1.8 / 2.2} . It can be easily set by calculation. As for the matrix 13, since the latter stage from the matrix 13 has a linear gradation characteristic by setting the latter stage LUTs 12 a, 12 b, and 12 c, simply giving predetermined Rgain, Ggain, and Bgain to the matrix 13, It is possible to correct the target chromaticity. FIG. 13 shows an example of Rgain, Ggain, and Bgain determined in advance. Since the measurement is not performed by the sensor 30, the calibration process becomes faster. However, since the previous LUTs 17a, 17b, and 17c and the matrix 13 are not set by actual measurement, the calibration is less accurate than the above-described high-accuracy mode.

JP 2004-096698 A

However, in order to realize calibration in both the high accuracy mode and the simple mode, it is necessary to provide LUTs at the front and rear stages of the matrix, increasing the cost of the display device. In the system of Patent Document 1, calibration is realized using one LUT for each color. However, since there is no means corresponding to the matrix, the LUT is responsible not only for correcting tone characteristics but also for correcting color components. In the above-described high-accuracy mode in the prior art, the matrix is set while measuring the chromaticity of the display panel with a sensor. When calibration such as the high-accuracy mode is executed in Patent Document 1, writing, chromaticity, and luminance measurement are repeated for each input level and for each color. The matrix is an arithmetic means as described above, and the color components are converted for all input levels simply by changing the matrix, so that the processing is fast. On the other hand, the writing speed to the LUT is generally low, and in Patent Document 1 in which writing is performed for each color of each input level, it takes a long time to complete the processing.

The present invention has been made in order to solve the above-mentioned problems. The display characteristics of the display device can be calibrated with only one LUT and one matrix for each color without requiring a long time. It is an object to provide a calibration method, a display characteristic calibration apparatus, and a computer program.

The display characteristic calibration apparatus according to the first aspect of the present invention is provided with a first correction unit that corrects the color distribution of the image signals of a plurality of colors by a predetermined calculation, and is provided for each of the plurality of colors at the subsequent stage of the first correction unit. And a second correction means for correcting the input / output relationship of the image signal by referring to and outputting the output level associated with the input level, and a subsequent stage of the second correction means. In the display characteristic calibration apparatus that calibrates the display characteristics of the display section, comprising: a display section that displays an image according to an output level for each of a plurality of colors; and a measuring section that measures the display characteristics of the display section. A first step of setting the first correction means so that a color distribution obtained from the display characteristics measured in step 1 becomes a target color distribution, and an image signal obtained from the display characteristics measured by the measurement means Input / output relationship and the first Based on the set value set to the first correction means in the process, characterized in that it is constituted to control the processing of the second process of setting the set value of the second correction means.

The display characteristic calibration apparatus according to a second aspect of the present invention is the display characteristic calibration apparatus according to the first aspect, wherein the second process is obtained from the display characteristic measured by the measuring means in a state where the correction of the first process is performed. A set value acquisition process for acquiring a set value to be set in the second correction means so that the input / output relation of the image signal to be a target input / output relation, and the first set in the first process Re-calculating the setting value acquired in the setting value acquisition process based on the setting value of the correction means, setting the recalculated setting value in the second correction means, and correction of the first correction means And a process for stopping the processing.

The display characteristic calibration apparatus according to a third aspect of the present invention is the display characteristic calibration device according to the first aspect, wherein the second step is a step of stopping the correction process of the first correction means and the first step set in the first step. A setting process for setting the setting value of the second correction means based on the setting value of the first correction means, and a state in which the correction of the first process is stopped and the second correction means is set in the setting process The second correction means is reset so that the input / output relationship of the image signal obtained from the display characteristics measured by the measurement means becomes the target input / output relationship. And

According to a fourth aspect of the present invention, in the first to third aspects of the invention, the display characteristic calibration apparatus acquires a specific set value from the set value for correcting the input / output relationship of the image signal stored in advance, and the set value Specific setting value is acquired from the third process of setting the second correction means to the second correction means and the setting value for correcting the color distribution of the image signal stored in advance, and the setting value is obtained as the first correction value. A fourth process set in the correction means and a configuration for controlling the process are further provided, and the process from the first process to the second process and the process from the third process to the fourth process are performed. It is characterized by being configured to be selectively executed.

A computer program according to a fifth aspect of the present invention is a computer program for causing a computer to calibrate display characteristics of a display unit that displays an image corresponding to an image signal of a plurality of colors, and is obtained from the display characteristics of the display unit. Based on the first process of correcting the color distribution to the target color distribution, the input / output relationship of the image signal obtained from the display characteristics of the display unit, and the correction information of the first process, The second process for correcting the output relation is performed.

A computer-readable recording medium according to the sixth invention is characterized by recording the computer program according to the fifth invention.

A display characteristic calibration method according to a seventh aspect of the present invention is the display characteristic calibration method for a display unit that displays an image according to an image signal of a plurality of colors, wherein the color distribution obtained by measuring the display characteristic of the display unit is a target. A first process for correcting the color distribution of the image signal by a predetermined calculation so as to achieve a color distribution to be performed, an input / output relationship of the image signal obtained by measuring display characteristics of the display unit, and a first process And a second step of correcting the input / output relationship of the image signal based on the set value set for correcting the image signal .

According to the present invention, since the LUT in the first stage of the matrix is not necessary, highly accurate calibration can be performed without increasing the cost of the display device.

In addition, since chromaticity calibration is performed by a high-speed matrix, high-accuracy calibration is possible without increasing the calibration processing time.

Further, since the LUT is provided in the front stage of the display panel, it is possible to perform a simple calibration in which the processing is completed in a short time by correcting only with the preset value stored without actually measuring.

It is a block diagram which shows the structure of the calibration system of the display apparatus which concerns on this Embodiment. It is a graph which shows the problem of the gradation characteristic set by LUT which concerns on this Embodiment. It is a flowchart which performs the high precision mode calibration which concerns on this Embodiment. It is a graph which shows the gradation characteristic set by LUT which concerns on this Embodiment. It is a graph which shows the gradation characteristic set to LUT which concerns on this Embodiment. It is a flowchart which performs the simple mode calibration which concerns on this Embodiment. It is a flowchart which performs the simple mode calibration which concerns on this Embodiment. It is a flowchart which performs the high precision mode calibration which concerns on this Embodiment 2. FIG. 14 is a graph showing gradation characteristics set in the LUT according to the second embodiment. It is a graph explaining the gradation characteristic of a display apparatus. It is a block diagram which shows the structure of the calibration system of the conventional display apparatus. It is a graph explaining the correction | amendment of the gradation characteristic by LUT. It is an example of the setting value set to a matrix.

Embodiment 1
FIG. 1 is a schematic block diagram of a display device calibration system according to the present invention, which will be described below with reference to the drawings.

The computer 20 inputs a red image signal Ri, a green image signal Gi, and a blue image signal Bi to a matrix 13 that is a color conversion circuit in the display device 10. The color image signals Rm, Gm, and Bm output from the matrix 13 are input to an R LUT 12a, a G LUT 12b, and a B LUT 12c that are gradation correction circuits provided for the respective colors. The color image signals Ro, Go, Bo output from the R LUT 12a, the G LUT 12b, and the B LUT 12c are output to the display panel 11, and an image having a density corresponding to the image signal level is displayed on the display panel 11. The chromaticity and luminance data Si obtained by measuring the displayed display image with the sensor 30 are input to the computer 20 and compared with the target gradation characteristic and the target chromaticity stored in the computer 20 in advance. The computer 20 outputs a control signal Co to the microcomputer MPU 14 in the display device 10 so as to eliminate the difference generated by the comparison. In accordance with the control signal Co, the MPU 14 changes the setting values of the matrix 13 to correct the color characteristics, and changes the setting values of the R LUT 12a, the G LUT 12b, and the B LUT 12c to correct the gradation characteristics. The MPU 14 is further connected to a memory 15 that stores various setting information and an input means 16 that can be operated by the user.

As shown in FIG. 1, in the present invention, the LUTs for correcting the gradation characteristics are only the color LUTs 12a, 12b, and 12c provided in the subsequent stage of the matrix 13. Thereby, an increase in cost of the display device 10 can be avoided, but there arises a problem that the circuit capability of each color LUT 12a, 12b, 12c cannot be fully utilized. A graph of this problem is shown in FIG. The horizontal axis indicates the levels of the image signals Rm, Gm, and Bm input to the respective color LUTs 12a, 12b, and 12c, and the vertical axis indicates the luminance value output from the display panel 11. The matrix 13 and the respective color LUTs 12a, 12b, and 12c are in a through state, and the gradation characteristics measured by the sensor 30 in that state are indicated by solid lines and black circles, and the target gradation characteristics are indicated by dotted lines and white circles. As in the past, at a specific luminance value, the input level (white circle) on the target gradation characteristic that emits the specific luminance value is associated with the input level (black circle) on the actually measured gradation characteristic, and each color LUT 12a, 12b, 12c is associated with it. Remember. The matrix 13 is adapted to the target chromaticity by changing the distribution ratio of each color input image signal Ri, Gi, Bi. That is, if the maximum level of each color input image signal Ri, Gi, Bi is 255, the maximum level of each color Rm, Gm, Bm output from the matrix 13 may be lower than 255. FIG. 2 shows a case where the maximum level of the input image signal is corrected from 255 to 110 by the matrix 13. In this case, although the image signal in the range of the input level 0 to 255 is output from the computer 20, the portions exceeding the input level 110 (shaded portions) are not used in each color LUT 12a, 12b, 12c. This problem lowers the resolution of correction by the LUT and obstructs faithful gradation expression, and is a problem that could not occur in the prior art in which gradation conversion was performed in the preceding LUT.

In order to avoid the above problem, in the present invention, calibration in the high accuracy mode is executed according to the procedure shown in FIG. The display device 10 starts calibration by an instruction from the outside or spontaneously, and the MPU 14 in the display device 10 puts the color LUTs 12a, 12b, 12c and the matrix 13 in the through state (S11). Next, the chromaticity displayed on the display panel 11 is measured by the sensor 30 (S12). The computer 20 compares the chromaticity specific to the display panel obtained in S12 with a predetermined target chromaticity, and sets the matrix 13 to eliminate the difference (S13). As described above, the matrix corrects the color distribution by matrix calculation, and approaches the target chromaticity while repeating rewriting of the matrix and measurement by the sensor 30. After the setting of the matrix 13 is completed, the gradation characteristics of the display panel 11 are measured by the sensor 30 with the chromaticity at the target value (S14). Specifically, the luminance value of the display panel 11 is measured for each input level while gradually changing the input level of each color image signal Ri, Gi, Bi output from the computer 20. Each color image signal Ri, Gi, Bi may be changed simultaneously, or may be changed for each color and measured. When changing each color image signal Ri, Gi, Bi simultaneously, it is necessary to make the sensor 30 or the computer 20 have a function of separating measured values for each color. The computer 20 compares the gradation characteristic specific to the display panel obtained in S14 with a predetermined target gradation characteristic, and calculates setting values of the color LUTs 12a, 12b, and 12c that eliminate the difference (S15). As described above, the LUT corrects gradation characteristics by associating an input level with an output level.

The calculation method in S15 will be described in detail with reference to FIG. FIG. 4 is a diagram showing the input level and the output level associated with each other in the LUT. The horizontal axis represents the input level to the LUT, and the vertical axis represents the output level associated with the input level in the LUT. As the maximum value set in the LUT, the assumed maximum value of the input image signal is generally assigned. In FIG. 4, 255 is the maximum value. The black circles in FIG. 4 are setting values that should be set in the LUT to correct the target gradation characteristics when the maximum input level is 255. For convenience, only nine black circles are shown, but in actuality, the correspondence to the input / output levels is set more finely. As described above, since the color LUTs 12a, 12b, and 12c are installed at the subsequent stage of the matrix 13, the LUT can be used only within the range corrected by the matrix 13. For example, when the maximum level is suppressed from 255 to 110 by the matrix 13, the range indicated by the hatched line in FIG. 4 is not used. As a result, the set values calculated in S15 are indicated by black squares and solid lines in FIG. 4 in which black circles and dotted lines in the input / output level 110 are expanded so that the maximum value of the input / output levels is 110.

In S16, the color LUTs 12a, 12b, and 12c are set based on the setting values obtained in S13 and S15. The set value obtained in S13 is a matrix set in the matrix 13. For example, when the maximum level is corrected to 255 in the matrix 13, Ri is 200, Gi is 200, and Bi is 110, the set determinant is as follows.
When the above matrix is calculated for the blue image signal Bi, for example, the matrix output Bm is calculated as follows.
The set value obtained in S15 is converted according to this arithmetic expression. A schematic representation of this is shown in FIG. There is no change in the output level range, and the input level range is expanded from 0 to 110 to 0 to 255 based on the determinant of S13. As a result, since the LUT can be used up to the shaded area, gradation correction with high resolution is possible. The same processing is performed for other color LUTs. For convenience, the determinant set in the matrix is assumed to have a value only in the diagonal component, but the present invention is not limited to this, and a color may be corrected by setting a value in the non-diagonal component.

After each color LUT 12a, 12b, 12c is completed, the matrix 13 is set to the through state (S17). Since the LUT is set in consideration of the color distribution in S16, the correction in the matrix 13 is not necessary. In the present invention, the matrix 13 is used only for quickly obtaining the optimum color distribution, and the actual color correction is performed by each of the color LUTs 12a, 12b, and 12c. The above is the processing procedure of the high accuracy mode calibration in the present invention.

The processing procedure of the simple mode calibration in the present invention will be described with reference to FIGS. 6 shows a processing procedure in the manufacturing process of the display device 10, and FIG. 7 shows a processing procedure when the user instructs calibration in the simple mode. First, the matrix 13 and the LUTs 12a, 12b, and 12c are set to the through state as in the high accuracy mode (S21). Next, the gradation characteristics of the display panel 11 are measured by the sensor 30 (S22). Each color LUT 12a, 12b, 12c is set so that the actually measured gradation characteristic is an arbitrary gradation characteristic (S23). The LUT setting method is the same as the conventional method. The set information of the set color LUTs 12a, 12b, and 12c is stored in the memory 15 in the display device 10 (S24). In the manufacturing process, each color LUT 12a, 12b, 12c is set for a plurality of gradation characteristics such as gamma coefficients 1, 1.8, 2.2. It is determined whether all the gradation characteristics to be set have been set (S25). If there are other gradation characteristics to be set, the process returns to S23, and if not, the process proceeds to S26. The chromaticity of the display panel 11 is measured by the sensor 30 (S26), and the matrix 13 is set so that the actually measured chromaticity becomes an arbitrary chromaticity (S28). Regarding the chromaticity, in the manufacturing process, the matrix 13 is set for a plurality of chromaticities such as 4500 [K], 5000 [K], 5500 [K], and 6000 [K]. It is determined whether or not all the chromaticities to be set have been set (S29). If there are other chromaticities to be set, the process returns to S27, and if not, the process ends. The above process may be performed not only by the manufacturing process but also by the user periodically.

The processing procedure of the simple mode calibration by the user will be described with reference to FIG. The MPU 14 receives a simple mode calibration execution instruction from the user via the input means 16 (S31). Specifically, an OSD (on-screen display) in which a plurality of gradation characteristics and chromaticities are made into a menu is displayed on the display device 10 so that the user operates the input means 16 provided on the display device 10 to select it. To. Alternatively, the user may operate the computer 20 and instruct the MPU 14 from the computer 20. The execution instruction includes information on tone characteristics and chromaticity desired by the user, and the MPU 14 acquires them (S32). The setting values of the color LUTs 12a, 12b, and 12c that realize the user-desired gradation characteristics are read from the setting information stored in the memory 15 in the manufacturing process (S33), and the read setting values are written to the LUTs 12a, 12b, and 12c. (S34). At this time, the gradation characteristics at the subsequent stage from the matrix 13 are not the distorted gradation characteristics unique to the display panel 11 but linear gradation characteristics represented by a gamma coefficient or the like. Next, the setting values of the matrix 13 for realizing the user-desired chromaticity are read from the setting information stored in the memory 15 in the manufacturing process (S35), and the read setting values are written to the matrix 13 (S36). Since the gradation characteristics at the subsequent stage from the matrix 13 are linear gradation characteristics at the time of S34, the color shift that occurs when color conversion is performed on the distorted gradation characteristics is avoided. In the series of processing, no measurement is performed by the sensor 30, and adjustment is performed only with preset information, so that arbitrary gradation characteristics and arbitrary chromaticity can be obtained at high speed.

Embodiment 2
FIG. 8 is a processing flow of calibration in the high accuracy mode according to the second embodiment. The configuration of the calibration system is the same as that of the first embodiment shown in FIG. Further, steps S11, S12, and S13 in FIG. 8 that are assigned the same reference numerals as those in FIG. 3 showing the calibration processing flow in the high-accuracy mode according to the first embodiment are the same as those in the first embodiment, and thus will be described. Is omitted.

In the second embodiment, after the matrix 13 is set in S13, the matrix 13 is set to the through state (S14b). Next, the input levels of the LUTs 12a, 12b, and 12c are set based on the setting information set in S13 (S15b). The process in S15b will be described with reference to FIG. Since the LUTs 12a, 12b, and 12c are in the through state in S11, the set values of the LUTs 12a, 12b, and 12c before S15b are those indicated by the black squares and dotted lines in FIG. In S14b, the level of the input signal is corrected by the matrix 13. For example, when the maximum input level is corrected to 110, the input levels of the LUTs 12a, 12b, and 12c are used only in the range of 0 to 110, and the hatched area in FIG. 9 is not used as in the first embodiment. . Therefore, in S15b, the input level reduced to the range of 0 to 110 in S14b is expanded to 0 to 255 while the output level remains unchanged. As a result, the setting values of the LUTs 12a, 12b, and 12c set in S11 indicated by black squares and dotted lines in FIG. 9 are converted to the setting values indicated by black diamonds and solid lines. The gradation characteristics of the display panel 11 are measured by the sensor 30 in a state where the set values of the LUTs 12a, 12b, and 12c are converted in S15b (S16b) and compared with a predetermined target gradation characteristic, the difference is eliminated. Each color LUT 12a, 12b, 12c is set so as to be performed (S17b). Since S16b and S17b are the same processing as S14 and S15 of the first embodiment, description thereof is omitted.

In the second embodiment, since the input level of the LUT is expanded to 255 in S15b, the LUT can be used up to the hatched area shown in FIG. 9, and gradation correction with high resolution is possible. Although the step of setting the matrix 13 in the through state (S14b) is set immediately after the matrix 13 is set, the present invention is not limited to this, and may be before the gradation characteristics of the display image are measured by the sensor 30 (S16b).

In the above-described embodiment, the computer and the display device execute the calibration process in conjunction with each other. However, the present invention is not limited to this, and the MPU in the display device is responsible for the processing in the computer to display the display device. You may make it perform a calibration process independently. Alternatively, a part of the processing in the computer, for example, the comparison between the measured value and the target value may be performed by the MPU in the display device. Conversely, the processing in the display device may be performed by a computer.

In the above-described embodiment, the matrix that performs the matrix operation is used as the color correction unit. However, the present invention is not limited to this, and an amplification circuit that relatively expands and contracts the image signal may be used.

In the above-described embodiment, RGB three-color image signals are input. However, the present invention is not limited to this, and two or more color image signals may be input.

10: Display device 11: Display panel 12a: Red image signal LUT
12b: Green image signal LUT
12c: Blue image signal LUT
13: Matrix 14: MPU
15: Memory 16: Input means 20: Computer 30: Sensor

Claims (7)

First correction means for correcting the color distribution of the image signals of a plurality of colors by a predetermined calculation;
The first correction means is provided for each of a plurality of colors, stores the input level and the output level in association with each other, and refers to the output level corresponding to the input level to output the image signal so that the input / output relationship is established. Second correcting means for correcting;
A display unit for displaying an image according to an output level for each of a plurality of colors output from the second stage of the second correction unit;
In a display characteristic calibration apparatus that calibrates the display characteristic of the display unit, comprising measurement means for measuring the display characteristic of the display unit,
A first step of setting the first correction means so that the color distribution obtained from the display characteristics measured by the measurement means becomes a target color distribution;
Based on the input / output relationship of the image signal obtained from the display characteristics measured by the measuring unit and the set value set in the first correcting unit in the first step, the set value of the second correcting unit A display characteristic calibration device characterized by having a configuration for controlling the processing with the second step of setting. The second process includes:
In a state in which the correction of the first process is performed, the second correction unit is set so that the input / output relationship of the image signal obtained from the display characteristic measured by the measurement unit becomes the target input / output relationship. A setting value acquisition process for acquiring a setting value to be set;
Based on the setting value of the first correction means set in the first process, the setting value acquired in the setting value acquisition process is recalculated, and the recalculated setting value is set in the second correction means. The process of
The display characteristic calibration apparatus according to claim 1, further comprising a step of stopping the correction processing of the first correction unit. The second process includes:
Stopping the correction process of the first correction means;
A setting step of setting a setting value of the second correction unit based on the setting value of the first correction unit set in the first step;
The input / output relationship of the image signal obtained from the display characteristics measured by the measurement unit in a state where the correction in the first step is stopped and the second correction unit is set in the setting step is a target and The display characteristic calibration apparatus according to claim 1, further comprising a step of resetting the second correction means so as to obtain an input / output relationship. A third step of acquiring a specific set value from the set value for correcting the input / output relationship of the image signal stored in advance, and setting the set value in the second correction unit;
A configuration in which a specific setting value is acquired from the setting value for correcting the color distribution of the image signal stored in advance, and the fourth process and processing for setting the setting value in the first correction unit are controlled. In addition,
The process from the first process to the second process and the process from the third process to the fourth process are selectively executed. The display characteristic calibration device described. In a computer program for causing a computer to calibrate display characteristics of a display unit that displays images according to image signals of a plurality of colors,
On the computer,
A first process of correcting the color distribution obtained from the display characteristics of the display unit to a target color distribution;
Based on the input / output relationship of the image signal obtained from the display characteristics of the display unit and the correction information of the first step, the second step of correcting to the target input / output relationship is performed. A computer program. A computer-readable recording medium on which the computer program according to claim 5 is recorded. In the display characteristic calibration method of the display unit that displays an image according to the image signals of a plurality of colors,
A first step of correcting the color distribution of the image signal by a predetermined calculation so that the color distribution obtained by measuring the display characteristics of the display unit becomes a target color distribution;
Based on the input / output relationship of the image signal obtained by measuring the display characteristics of the display unit and the setting value set for correcting the image signal in the first process, the target input / output relationship is obtained. And a second process of correcting the input / output relationship of the image signal .