WO2015174125A1

WO2015174125A1 - Video signal processing device and video signal processing method

Info

Publication number: WO2015174125A1
Application number: PCT/JP2015/056782
Authority: WO
Inventors: 雅人赤尾; 西堀　一彦
Original assignee: ソニー株式会社
Priority date: 2014-05-15
Filing date: 2015-03-09
Publication date: 2015-11-19

Abstract

Cumulative degree of risk of degradation is calculated for each area by calculating and accumulating the degrees of risk of degradation for each area into which a displayed image is divided from the amount of light emitted by each pixel based on a video signal by a light emission calculation unit (302), a block degree of risk calculation unit (303), a block degree of risk updating unit (304), an area degree of risk calculation unit (305), and an area degree of risk updating unit (306). A gain calculation unit (307) calculates the degree of risk of degradation for each pixel from the cumulative degree of risk of degradation that has been calculated for each area and calculates correction gain for each pixel on the basis of the degree of risk of degradation for each pixel and brightness for each pixel. A multiplier (390) corrects the signal level of the video signal using a correction gain calculated by the gain calculation unit (307). The signal level for the video signal is adjusted such that the brightness for areas for which the degree of risk of degradation is high is lower than that for areas for which the degree of risk of degradation is low. Thus, increased life for light emitting elements and high visibility of the display can be achieved.

Description

Video signal processing apparatus and video signal processing method

This technology relates to a video signal processing device and a video signal processing method, and realizes a long life of the light emitting element and high visibility of display.

As a flat and thin display device, a liquid crystal display device using liquid crystal has been put into practical use. A liquid crystal display device is a display device that displays an image by providing a backlight and changing the arrangement of liquid crystal molecules by applying a voltage, thereby allowing light from the backlight to pass or block.

In recent years, self-luminous display devices using organic EL (electroluminescence) elements that emit light when a voltage is applied have been put into practical use. When the organic EL element receives energy by an electric field, the organic EL element changes from a ground state to an excited state, and emits differential energy as light when returning from the excited state to the ground state. The organic EL display device is a display device that displays an image using light emitted from the organic EL element.

The self-luminous display device does not require a backlight because the element emits light by itself, and the device can be configured thinner than a liquid crystal display device. In addition, the organic EL display device is superior in moving image characteristics, viewing angle characteristics, color reproducibility, and the like as compared with a liquid crystal display device.

However, the organic EL element deteriorates in light emission characteristics when voltage is continuously applied, and the luminance decreases even when the same current is input. As a result, a pixel having a high light emission frequency is in a state in which the light emission characteristic is deteriorated as compared with other pixels, and a so-called “burn-in” phenomenon may occur. Therefore, in the self-luminous display device, for example, as disclosed in Patent Document 1, the amount of current is controlled to correct the burn-in.

International Publication No. 2008/149842

However, in the method described in Patent Document 1, luminance control corresponding to pixels with a high degree of deterioration is uniformly performed on the entire screen. For this reason, for example, if the luminance is lowered to suppress deterioration of a portion that is always brightly displayed on the display screen, the luminance of other portions may be lowered uniformly and the visibility of the display may be impaired. .

Therefore, it is an object of the present technology to provide a video signal processing apparatus and a video signal processing method capable of realizing a long lifetime of a light emitting element and high visibility of display.

The first aspect of this technology is
Accumulated degradation risk that calculates the degradation risk for each area obtained by dividing the display screen from the light emission amount for each pixel based on the video signal, and accumulates the calculated degradation risk for each area. A degree calculator,
A gain calculation unit that calculates a deterioration risk for each pixel from the cumulative deterioration risk for each region, and calculates a correction gain for each pixel based on the deterioration risk for each pixel and the luminance for each pixel;
And a correction unit that corrects a signal level of the video signal using the correction gain.

In this technique, the cumulative deterioration risk calculation unit calculates, for example, a deterioration risk for each area obtained by dividing the entire display screen from the light emission amount for each pixel based on the video signal, and calculates the calculated deterioration risk for each area. The cumulative deterioration risk is calculated by accumulating. For example, in the cumulative deterioration risk calculation unit, the cumulative block deterioration risk is calculated by accumulating the maximum deterioration risk of the pixels in the block for each region composed of one or a plurality of blocks. The cumulative block deterioration risk is accumulated to calculate the cumulative deterioration risk for each region.

The gain calculation unit calculates the deterioration risk for each pixel from the cumulative deterioration risk for each region, and calculates a correction gain for each pixel based on the deterioration risk for each pixel and the luminance for each pixel. For example, the gain calculation unit calculates the pixel degradation risk using the cumulative degradation risk of the region including the pixel for which the degradation risk is calculated and the cumulative degradation risk of the region adjacent to the region. Further, for example, the gain calculation unit calculates a gain adjustment amount for each pixel according to the degree of deterioration risk for each pixel, and calculates a correction gain based on the gain adjustment amount for each pixel and the luminance of the pixel. Further, a target gain map storage unit that stores a target gain map in which a target gain, which is an allowable luminance reduction amount of a light emitting element that emits light based on a video signal, is shown for each pixel position is provided. A gain adjustment amount is calculated for each pixel in accordance with the deterioration risk, the luminance for each pixel, and the target gain. The target gain map in the target gain map storage unit can be updated with a target gain map acquired from the outside. The gain adjustment amount is calculated so that, for example, the degree of deterioration of the light emitting element that lowers the luminance of the pixel based on the target gain becomes a desired degree of deterioration. In addition, the luminance is calculated so as to decrease at a desired speed in the pixels in the region where the light emitting element is likely to deteriorate based on the target gain.

In addition, a target gain map creating unit for creating a target gain map is provided, and in the target gain map creating unit, a cumulative light emission amount calculated for each pixel using a sample image according to a ratio of display time for each application, A target gain map is created based on the deterioration characteristics of the light emitting elements that emit light based on the video signal. The sample image or deterioration characteristic can be updated to a sample image or deterioration characteristic acquired from the outside. The target gain map creation unit calculates a target gain map for each application based on the accumulated light emission amount calculated for each pixel based on the application image and the deterioration characteristics of the light emitting element that emits light based on the video signal. Then, the gain calculation unit calculates the correction gain using the target gain map of the application that matches the application of the video signal. The target gain map creation unit creates a target gain map based on the accumulated light emission amount calculated for each pixel using the video signal corrected by the correction unit and the deterioration characteristics of the light emitting elements that emit light based on the video signal. Is done.

The second aspect of this technology is
The cumulative deterioration risk calculation unit calculates the deterioration risk for each area obtained by dividing the display screen from the light emission amount for each pixel based on the video signal, and accumulates the calculated deterioration risk for each area. A process of calculating the risk,
A gain calculation unit calculating a deterioration risk for each pixel from the cumulative deterioration risk for each region, and calculating a correction gain for each pixel based on the deterioration risk for each pixel and the luminance for each pixel;
And a step of correcting the signal level of the video signal using the correction gain in a correction unit.

According to this technology, the cumulative deterioration risk calculation unit calculates the deterioration risk for each area obtained by dividing the display screen from the light emission amount for each pixel based on the video signal, and accumulates it for each area. The degree is calculated. Further, the gain calculation unit calculates the deterioration risk for each pixel from the cumulative deterioration risk for each region, and calculates a correction gain for each pixel based on the deterioration risk for each pixel and the luminance for each pixel. Further, the correction unit corrects the signal level of the video signal using the correction gain. For this reason, the signal level of the video signal is adjusted so that the luminance is lower in the high degradation risk region than in the low degradation risk region, so that the lifetime of the light emitting element and the high visibility of the display can be realized. . Note that the effects described in the present specification are merely examples and are not limited, and may have additional effects.

It is the figure which illustrated the structure of the display apparatus. It is the figure which illustrated the composition of a 1st embodiment. It is the figure which illustrated the block division. It is the figure which showed the relationship between the light-emission quantity and a degradation risk. It is a figure for demonstrating the process performed in a block risk update part. It is the figure which illustrated area division. It is a figure for demonstrating the process performed in an area risk update part. It is a figure for demonstrating the calculation method of the degradation risk degree for every pixel in an area. It is the figure which illustrated the relationship between the distance from the boundary with an adjacent area, and a blend ratio. It is the figure which showed the relationship between a degradation risk and a gain adjustment amount. It is the figure which showed the relationship between input luminance and correction | amendment gain. It is the figure which illustrated the relationship between input luminance and output luminance. It is the flowchart which showed operation | movement of 1st Embodiment. It is the flowchart which showed the calculation process of block deterioration risk. It is the flowchart which showed the update process of accumulation block deterioration risk. It is the flowchart which showed the calculation process of area degradation risk. It is a flowchart which shows the calculation process of correction | amendment gain. It is the figure which illustrated screen composition. It is the figure which illustrated the composition of a 2nd embodiment. It is the figure which illustrated the composition of the target gain map creation part. It is the figure which illustrated the user profile. It is the figure which illustrated the relationship between the accumulated light emission amount and the luminance reduction amount. It is the figure which showed the relationship between a degradation risk and a gain adjustment amount. It is a flowchart which shows the preparation operation of a target gain map. It is the figure which showed the relationship between a degradation risk and a gain adjustment amount. It is the figure which illustrated the composition of a 4th embodiment. The structure of the target gain map preparation part classified by application is shown. It is a flowchart which shows the selection process of the target gain map classified by application. It is the figure which illustrated the structure of 5th Embodiment. It is the figure which illustrated the structure in case the target gain map preparation part is mounted in the display apparatus. It is the figure which illustrated the composition of the target gain map creation part. The structure of the target gain map preparation part in 6th Embodiment is illustrated.

Hereinafter, embodiments for carrying out the present technology will be described. The description will be given in the following order.
1. 1. About display device 1. First embodiment 2. Second embodiment 3. Third embodiment 4. Fourth embodiment Fifth embodiment 6. Sixth embodiment Other embodiments

<1. About display device>
FIG. 1 illustrates the configuration of the display device. The display device 10 includes a control unit 11, a recording unit 12, a signal processing unit 20, an overcurrent detection unit 61, a data driver 62, a gamma circuit 63, and a panel 65.

The signal processing unit 20 includes an edge blurring unit 21, an I / F (interface) unit 22, a linear conversion unit 23, a pattern generation unit 24, a color temperature adjustment unit 25, a still image detection unit 26, a long-term color temperature correction unit 27, and light emission. A time control unit 28 is included. The signal processing unit 20 includes a signal level correction unit 30, a storage unit 40, an unevenness correction unit 51, a gamma conversion unit 52, a dither processing unit 53, a signal output unit 54, a long-term color temperature correction detection unit 55, and a gate pulse output unit. 56 and a gamma circuit control unit 57.

When the display device 10 receives the supply of the video signal, the display device 10 analyzes the video signal, and displays an image through the panel 65 by lighting pixels arranged in the panel 65 to be described later according to the analyzed content. To do.

The control unit 11 controls the signal processing unit 20 and exchanges signals with the I / F unit 22. In addition, the control unit 11 performs various signal processing on the signal received from the I / F unit 22.

The recording unit 12 stores information for controlling the signal processing unit 20 in the control unit 11. As the recording unit 12, it is preferable to use a memory that can store information without being erased even when the display device 10 is powered off. As the memory employed as the recording unit 12, it is desirable to use, for example, an EEPROM (Electronically-Erasable-and Programmable-Read-Only-Memory) that can be electrically rewritten. The EEPROM is a non-volatile memory in which data can be written and erased while being mounted on a substrate, and is suitable for storing information of the display device 10 that changes every moment.

The signal processing unit 20 inputs a video signal and performs signal processing on the input video signal. The signal processing unit 20 performs signal processing on the input video signal in each unit inside the signal processing unit 20.

The edge blurring unit 21 performs signal processing for blurring edges on the input video signal. Specifically, in order to prevent the image burn-in phenomenon on the panel 65, the edge blurring unit 21 suppresses the image burn-in phenomenon by performing a process of intentionally shifting the image to blur the edge.

The linear conversion unit 23 performs signal processing for converting a video signal whose output with respect to input has gamma characteristics so as to have linear characteristics from gamma characteristics. By performing signal processing so that the output with respect to the input has a linear characteristic in the linear conversion unit 23, various processes for the image displayed on the panel 65 are facilitated.

The pattern generation unit 24 generates a test pattern used in image processing inside the display device 10. As a test pattern used for image processing inside the display device 10, for example, there is a test pattern used for display inspection of the panel 65.

The color temperature adjustment unit 25 adjusts the color temperature of the image displayed on the panel 65 of the display device 10. Although not shown in FIG. 1, the display device 10 includes a color temperature adjusting unit for adjusting the color temperature, and an image displayed on the screen when the user operates the color temperature adjusting unit. The color temperature of can be adjusted manually.

The long-term color temperature correction unit 27 corrects a secular change due to a difference in luminance-time characteristics (LT characteristics) of each color of R (red), G (green), and B (blue) of the organic EL element. Since the organic EL element has different LT characteristics for R, G, and B colors, the color balance is lost as the light emission time elapses. The color balance is corrected.

The light emission time control unit 28 calculates the duty ratio of a pulse when displaying an image on the panel 65, and controls the light emission time of the organic EL element. The display device 10 displays an image by causing the organic EL element to emit light by applying a current to the organic EL element inside the panel 65 while the pulse indicates the light emission period.

The signal level correction unit 30 adjusts the luminance of the video displayed on the panel 65 by correcting the signal level of the video signal in order to realize a long life of the light emitting element and high visibility of the display. The signal level correction unit 30 calculates the cumulative risk of deterioration by calculating the risk of deterioration for each region obtained by dividing the display screen from the light emission amount for each pixel based on the video signal, and accumulating it for each region. Further, the signal level correction unit 30 calculates the deterioration risk for each pixel from the cumulative deterioration risk for each region, and calculates a correction gain for each pixel based on the deterioration risk for each pixel and the luminance for each pixel. Further, the signal level correction unit 30 corrects the signal level of the video signal using the correction gain so that the luminance of the video signal is lower in the high degradation risk region than in the low degradation risk region. Adjust the level. The configuration and operation of the signal level correction unit 30 will be described in detail later.

The long-term color temperature correction detection unit 55 detects information for correction by the long-term color temperature correction unit 27. Information detected by the long-term color temperature correction detection unit 55 is sent to the control unit 11 through the I / F unit 22 and recorded in the recording unit 12 through the control unit 11.

The unevenness correction unit 51 corrects unevenness of images and videos displayed on the panel 65. The unevenness correction unit 51 corrects the horizontal stripes, vertical stripes, and spots on the entire screen of the panel 65 based on the level of the input signal and the coordinate position.

The gamma conversion unit 52 performs signal processing for converting the video signal converted to have linear characteristics by the linear conversion unit 23 so as to have gamma characteristics. The signal processing performed in the gamma conversion unit 52 cancels the gamma characteristic of the panel 65 and converts the signal into a signal having linear characteristics so that the organic EL element in the panel 65 emits light according to the signal current. It is processing.

The dither processing unit 53 performs dithering on the signal converted by the gamma conversion unit 52. Dithering is to display a combination of displayable colors in order to express intermediate colors in an environment where the number of usable colors is small. By performing dithering in the dither processing unit 53, colors that cannot be originally displayed on the panel can be apparently created and expressed.
To do.

The signal output unit 54 outputs the signal after the dithering is performed by the dither processing unit 53 to the data driver 62. A signal passed from the signal output unit 54 to the data driver 62 is a signal including information on the light emission amounts of the R, G, and B colors, and a signal including light emission time information is transmitted from the gate pulse output unit 56 as a pulse signal. Output in the format.

The gate pulse output unit 56 outputs a pulse for controlling the light emission time of the panel 65. The pulse output from the gate pulse output unit 56 is a pulse with a duty ratio calculated by the light emission time control unit 28. The light emission time of each pixel on the panel 65 is determined by the pulse from the gate pulse output unit 56.

The gamma circuit control unit 57 gives a set value to the gamma circuit 63. The setting value given by the gamma circuit control unit 57 is a reference voltage to be given to the ladder resistance of the D / A converter included in the data driver 62.

The storage unit 40 stores information used when the signal level correction unit 30 corrects the luminance. The storage unit 40 stores, for example, information used at the end of the previous operation when the operation of the display device 10 is started or predetermined information used in the processing of the signal level correction unit 30. In this case, it is desirable to use an EEPROM (Electronically と Erasable and Programmable Read Only Memory) that can be electrically rewritten, for example, as in the recording unit 12, similarly to the recording unit 12. The storage unit 40 uses, for example, a memory whose contents are erased when the power is turned off, for example, SDRAM (Synchronous Dynamic Random Access Memory) when storing only information generated after the operation of the display device 10 is started. Is desirable. Moreover, the memory | storage part 40 may be comprised using EEPROM and SDRAM, and may use a memory properly according to the information to memorize | store.

The overcurrent detection unit 61 detects the overcurrent and notifies the gate pulse output unit 56 when the overcurrent occurs due to a short circuit of the substrate or the like. The overcurrent occurrence notification from the overcurrent detection unit 61 can prevent the overcurrent from being applied to the panel 65 when an overcurrent occurs.

The data driver 62 performs signal processing on the signal received from the signal output unit 54, and outputs a signal for displaying an image on the panel 65 to the panel 65. Although not shown, the data driver 62 includes a D / A converter. The D / A converter converts a digital signal into an analog signal and outputs the analog signal.

The gamma circuit 63 gives a reference voltage to the ladder resistance of the D / A converter included in the data driver 62. The reference voltage to be applied to the ladder resistor is generated by the gamma circuit control unit 57 as described above.

The panel 65 receives an output signal from the data driver 62 and an output pulse from the gate pulse output unit 56, and causes an organic EL element, which is an example of a self-light-emitting element, to emit light according to the input signal and pulse. And still images. The panel 65 has a flat surface for displaying an image. An organic EL element is a self-luminous element that emits light when a voltage is applied, and the light emission amount is proportional to the voltage. Therefore, the IL characteristic (current emission amount characteristic) of the organic EL element also has a proportional relationship.

Although not shown, the panel 65 has a scanning line for selecting a pixel in a scanning cycle, a data line for supplying luminance information for driving the pixel, and a current amount controlled based on the luminance information to emit light according to the current amount. Pixel circuits that emit light from the organic EL element, which is an element, are arranged in a matrix. Since the scanning lines, the data lines, and the pixel circuits are configured in this way, the display device 10 can display an image according to the video signal.

In the display device 10, the linear conversion unit 23 converts the video signal to have linear characteristics, and then inputs the converted video signal to the pattern generation unit 24. However, the pattern generation unit 24 and the linear conversion unit 23 It may be a configuration in which and are replaced. In addition, the signal processing unit 20 of the display device 10 is not limited to the configuration illustrated in FIG. 1, and may have a configuration in which some functional blocks are omitted, and a configuration in which functional blocks having new functions are added. It may be.

<2. First Embodiment>
Next, a first embodiment of the present technology will be described. FIG. 2 illustrates the configuration of the first embodiment, and the video signal processing device of the present technology is applied to the signal processing unit.

In the first embodiment, the signal level correction unit 30 in the signal processing unit 20 includes a luminance calculation unit 301, a light emission amount calculation unit 302, a block risk level calculation unit 303, a block risk level update unit 304, and an area risk level calculation unit. 305, an area risk update unit 306, a gain calculation unit 307, and a multiplier 390. The storage unit 40 includes a block risk storage unit 401 and an area risk storage unit 402. Note that the luminance calculation unit 301 to the area risk level update unit 306 in the first embodiment and the later-described embodiments correspond to a cumulative deterioration risk level calculation unit, and the multiplier 390 corresponds to a correction unit.

The luminance calculation unit 301 calculates the luminance from the video signal having the linear characteristic converted by the linear conversion unit 23. The luminance calculation unit 301 outputs the calculated luminance to the light emission amount calculation unit 302 and the gain calculation unit 307. For example, the video signal is a three primary color signal (R, G, B), and ITU-R BT. When the rule of 601 is used, the luminance Y can be calculated based on the formula (1).

The light emission amount calculation unit 302 calculates the light emission amount of each pixel of the panel 65 per frame based on the luminance calculated by the luminance calculation unit 301 and the duty ratio of the pulse calculated by the light emission time control unit 28. The organic EL element in the panel 65 has a linear (linear) relationship between the current and the light emission amount. Therefore, the light emission amount calculation unit 302 obtains a value obtained by multiplying the luminance Y calculated by the luminance calculation unit 301 by the duty ratio DR of the pulse calculated by the light emission time control unit 28 (obtained by luminance × duty ratio) for each pixel. Is the amount of light emission E per frame. The light emission amount calculation unit 302 outputs the calculated light emission amount to the block risk degree calculation unit 303.

The block risk calculation unit 303 calculates the block deterioration risk based on the light emission amount calculated by the light emission amount calculation unit 302. The block risk degree calculation unit 303 divides the entire display screen of the panel 65 into a plurality of blocks. FIG. 3 shows an example of block division. For example, each block is divided into 4 × 8 blocks with the same block size. Note that the size of each block and the number of blocks are not limited to those shown in the figure. Thereafter, the block risk calculation unit 303 calculates the deterioration risk dgr from the light emission amount E of each pixel constituting the block for each block. FIG. 4 and Expression (2) show the relationship between the light emission amount and the degradation risk level, and the degradation risk level dgr is a value corresponding to the light emission amount E of the pixel, that is, a parameter related to the degradation of the light emission characteristic of the pixel. In FIG. 4 and equation (2), the deterioration risk upper limit value dgr_max, the deterioration risk lower limit value dgr_min, the light emission amount E0 when the deterioration risk degree dgr = 0, the coefficients Kd0 (> 0), Kd1 (> 0) Are preset according to the characteristics of the panel 65 and the like.

The block risk degree calculation unit 303 selects the maximum value in the block from the deterioration risk degree dgr calculated for each pixel constituting the block, and sets the selected deterioration risk degree dgr as the block deterioration risk degree dgr_bf. The block risk degree calculation unit 303 outputs the block deterioration risk degree dgr_bf calculated for each block to the block risk degree update unit 304.

The block risk update unit 304 updates the cumulative block deterioration risk using the block deterioration risk calculated by the block risk calculation unit 303 for each block. The cumulative block deterioration risk is, for example, a cumulative value for each block of the block deterioration risk calculated for each frame. The cumulative block deterioration risk is a cumulative value of the block deterioration risk from a predetermined timing, for example, the operation start of the display device 10, the first operation start every day, the first operation start after the display device 10 is obtained, and the like.

FIG. 5 is a diagram for explaining processing performed by the block risk update unit. The block risk update unit 304 adds the block deterioration risk dgr_bf of the current frame calculated by the block risk calculation unit 303 to the already calculated cumulative block deterioration risk dgr_b, and adds the cumulative block deterioration risk dgr_b. Update. That is, the block risk update unit 304 updates the cumulative block deterioration risk dgr_b by performing the calculation of Expression (3). Note that dgr_b_max is a preset maximum cumulative block deterioration risk. Further, CLIP () in Expression (3) and Expressions described later is processing shown in Expression (4).

The block risk update unit 304 adds, for example, the cumulative block deterioration risk dgr_b stored in the block risk storage unit 401 of the storage unit 40 and the block deterioration risk dgr_bf of the current frame in units of blocks. The block risk update unit 304 sets the addition result as a new cumulative block deterioration risk dgr_b. Also, the block risk update unit 304 adds the updated cumulative block deterioration risk dgr_b and the block deterioration risk dgr_bf of the next frame to obtain a new cumulative block deterioration risk dgr_b. Such update of the accumulated block deterioration risk is performed in units of blocks, for example, every frame or every predetermined frame interval, and the updated accumulated block deterioration risk dgr_b is updated to the area risk calculation unit 305 and the block risk update unit 304. And output to the block risk storage unit 401. The block risk update unit 304 stores the accumulated block deterioration risk in the block risk storage unit 401 at the end of the operation so that the cumulative block deterioration risk can be continuously updated from the end of the previous operation at the start of the next operation. The accumulated block deterioration risk degree may be updated.

Here, the coefficients Kd0 and Kd1 in the block risk calculation unit 303 are parameters that affect the increase or decrease in the cumulative block deterioration risk. That is, when the coefficient Kd0 is large, the cumulative block deterioration risk is reduced more quickly than when the coefficient Kd0 is small. When the coefficient Kd1 is small, the cumulative block deterioration risk increases gradually as compared with the case where the coefficient Kd1 is large. Therefore, it is possible to adjust the change in the cumulative block deterioration risk by the coefficients Kd0 and Kd1.

The area risk level calculation unit 305 divides the entire display screen into a plurality of areas. Each area is composed of one or a plurality of blocks. FIG. 6 exemplifies area division, and shows, for example, a case where a 4 × 8 block is divided into 3 × 3 areas. The area risk level calculation unit 305 performs area classification in consideration of the content displayed on the panel 65 and the like. For example, area division is performed so that a region where a predetermined image is displayed at a predetermined position, such as a menu display, and a region where a captured image, a content image, various information, and the like are displayed are divided.

The area risk level calculation unit 305 selects the maximum value in the area from the cumulative block deterioration risk level dgr_b calculated for the blocks constituting the area, and sets the selected cumulative block deterioration risk level as the area deterioration risk level dgr_af. . The area risk level calculation unit 305 outputs the area deterioration risk level dgr_af calculated for each area to the area risk level update unit 306.

The area risk update unit 306 updates the accumulated area deterioration risk for each area using the area deterioration risk calculated by the area risk calculation unit 305. The cumulative area deterioration risk is, for example, a cumulative value for each area of the area deterioration risk calculated for each frame. The cumulative area deterioration risk is a cumulative value from a predetermined timing equal to the block deterioration risk.

In addition, in the update of the cumulative area deterioration risk, in order to stabilize the time for the update of the cumulative area deterioration risk, the ratio between the area deterioration risk dgr_af of the current frame and the already calculated cumulative area deterioration risk dgr_a is adjusted. And add. FIG. 7 is a diagram for explaining processing performed in the area risk update unit. The coefficient Kt (0 ≦ Kt <1) is a coefficient for stabilizing the time, and is set in advance to be changeable to or from a predetermined value. The area risk update unit 306 multiplies the area deterioration risk dgr_af of the current frame calculated by the area risk calculation unit 305 by a coefficient (1-Kt) and the already calculated cumulative area deterioration risk dgr_a by a coefficient Kt. To do. Further, the area risk update unit 306 adds the area deterioration risk dgr_af multiplied by the coefficient (1−Kt) to the cumulative area deterioration risk dgr_a multiplied by the coefficient Kt, and has already calculated the accumulated area deterioration. The risk level dgr_a is updated. That is, the area risk update unit 306 performs the calculation of Expression (5) and updates the accumulated area deterioration risk dgr_a. Note that the calculation of Expression (5) corresponds to an IIR filter. Note that when the coefficient Kt increases, the change in the cumulative area deterioration risk between frames decreases, and the time stability increases.

The area risk update unit 306 uses the cumulative area deterioration risk dgr_a, the area deterioration risk dgr_af of the current frame, and the coefficient Kt, for example, for each area, for example, stored in the area risk storage unit 402 of the storage unit 40. A cumulative area deterioration risk dgr_a is calculated. The area risk update unit 306 calculates a new accumulated area deterioration risk dgr_a using the updated accumulated area deterioration risk dgr_a, the area deterioration risk dgr_af of the next frame, and the coefficient Kt. Such update of the accumulated area degradation risk is performed in units of areas, for example, every frame or every predetermined frame interval, and the updated accumulated area degradation risk dgr_a is output to the gain calculation unit 307 and the area risk storage unit 402. To do. The area risk level update unit 306 stores the accumulated area deterioration risk level in the area risk level storage unit 402 at the end of the operation so that the cumulative area deterioration risk level can be continuously updated from the end of the previous operation at the start of the next operation. The accumulated area deterioration risk may be updated. In addition, the time stability is improved by increasing the frame interval for updating the cumulative deterioration risk.

The gain calculation unit 307 corrects the signal level of the video signal by the multiplier 390 based on the luminance output from the luminance calculation unit 301 and the accumulated area deterioration risk dgr_a output from the area risk update unit 306. Calculate the correction gain. Further, the gain calculation unit 307 performs blending of the cumulative area deterioration risk so that the boundary of the area becomes inconspicuous when brightness control is performed with the calculated correction gain, and the correction gain is based on the deterioration risk after blending. Is calculated for each pixel.

FIG. 8 is a diagram for explaining a method of calculating the deterioration risk for each pixel in the area. FIG. 8 shows a case where the deterioration risk dgr_p of the pixel p in the area AR0 is calculated.

The gain calculation unit 307 determines the blend ratio Kr according to the distance from the boundary with the adjacent area. FIG. 9 illustrates the relationship between the distance from the boundary with the adjacent area and the blend ratio. FIG. 9 illustrates the relationship between the distance from the boundary with the area AR1 adjacent in the x direction and the blend ratio.

As shown in FIG. 9, the gain calculation unit 307 sets the blend ratio to “0.5” when the distance from the boundary with the area AR1 adjacent in the F1 direction is “0”. Further, the blend ratio is set to “1” at the distance “ThD_f1”. The distance “ThD_f1” is set in advance based on the display size of the panel 65, the number of display pixels, and the like so that the blend processing range is not conspicuous.

Here, when the pixel P is a distance Lf1 from the boundary with the area AR1 adjacent in the F1 direction, the blend ratio Krf1 is obtained. Similarly to the F1 direction, the gain calculation unit 307 blends based on the blend ratio Krf2 based on the distance Lf2 from the boundary with the area AR2 adjacent in the F2 direction and based on the distance Lf3 from the boundary with the area AR3 adjacent in the F3 direction. The ratio Krf3 is determined. Note that the change in the blend ratio from the boundary to the distance “ThD_f1” is not limited to a linear function as shown in FIG. 9, but may be changed with other characteristics.

Next, the gain calculation unit 307 calculates the deterioration risk corresponding to the pixel P based on the cumulative area deterioration risk of the adjacent area, the cumulative area deterioration risk of the area including the pixel P, and the determined blend ratio. Equation (6) calculates the degradation risk corresponding to the pixel P based on the cumulative area degradation risk dgr_a1 of the area AR1 adjacent in the F1 direction, the cumulative area degradation risk dgr_a0 of the area AR0 including the pixel P, and the blend ratio Krf1. It is an expression to do. Expression (7) calculates the degradation risk corresponding to the pixel P based on the cumulative area degradation risk dgr_a2 of the area AR2 adjacent in the F2 direction, the cumulative area degradation risk dgr_a0 of the area AR0 including the pixel P, and the blend ratio Krf2. It is an expression to do. Equation (8) calculates the degradation risk corresponding to the pixel P based on the cumulative area degradation risk dgr_a3 of the area AR3 adjacent in the F3 direction, the cumulative area degradation risk dgr_a0 of the area AR0 including the pixel P, and the blend ratio Krf3. It is an expression to do.

Further, the gain calculation unit 307 has the highest risk of deterioration of the pixel P in the deterioration risks dgr_p1, dgr_p2, and dgr_p3 calculated based on the positional relationship with the adjacent areas, as shown in Expression (9). Let dgr_p. Since the degradation risk dgr_b is “0” or more as apparent from the equation (3), the degradation risk dgr_a is also “0” or more, so the degradation risk dgr_p of the pixel P is also “0” or more. Become.

The gain calculation unit 307 calculates the gain adjustment amount gainC based on the equation (10) in accordance with the degradation risk dgr_p calculated for each pixel. FIG. 10 is a diagram showing the relationship between the deterioration risk and the gain adjustment amount. The maximum gain value gain_max and the threshold values ThDgr0 and ThDgr1 are set in advance according to the characteristics of the panel 65 and the like.

Next, the gain calculation unit 307 calculates a correction gain gain_p based on the equation (11) according to the calculated gain adjustment amount gainC. FIG. 11 is a diagram illustrating the relationship between the input luminance and the correction gain. The threshold value ThY is preset according to the characteristics of the panel 65 and the like.

The gain calculation unit 307 outputs a correction gain gain_p corresponding to the luminance of the pixel p to the multiplier 390. The gain calculation unit 307 performs the same process for other pixels, and outputs a correction gain corresponding to the luminance of each pixel to the multiplier 390.

The multiplier 390 multiplies the video signal by the correction gain calculated by the gain calculation unit 307, corrects the signal level of the video signal, and outputs the corrected signal level. Here, the gain adjustment amount is calculated as shown in FIG. 10 based on the degree of deterioration risk calculated according to the input luminance, and the correction gain is calculated as shown in FIG. 11 according to the input luminance. Therefore, as shown in FIG. 12 illustrating the relationship between the input luminance and the output luminance, when the input luminance Yin exceeds the threshold value ThY, the output luminance Yout is lower than the input luminance Yin according to the level of the input luminance Yin.

FIG. 13 is a flowchart showing the operation of the first embodiment. In step ST1, the signal level correction unit 30 calculates the light emission amount. The signal level correction unit 30 calculates the light emission amount by multiplying the luminance of the input video signal and the duty ratio, and proceeds to step ST2.

In step ST2, the signal level correction unit 30 calculates the risk of block deterioration. The signal level correction unit 30 divides the entire display screen of the panel 65 into a plurality of blocks, and performs a process of calculating the pixel burn-in deterioration risk based on the light emission amount in units of blocks. FIG. 14 is a flowchart showing a block deterioration risk degree calculation process.

In step ST11, the signal level correction unit 30 selects a pixel. The signal level correction unit 30 selects a pixel to calculate the block deterioration risk and proceeds to step ST12.

In step ST12, the signal level correction unit 30 calculates the block number to which the pixel belongs. Based on the pixel position of the pixel selected in step ST11, the signal level correction unit 30 calculates the block number to which the pixel belongs, and proceeds to step ST13.

In step ST13, the signal level correction unit 30 calculates the deterioration risk from the light emission amount of the pixel. The signal level correction unit 30 performs the calculation of the above equation (2), calculates the deterioration risk of the selected pixel based on the light emission amount, and proceeds to step ST14.

In step ST14, the signal level correction unit 30 determines whether or not the maximum deterioration risk level of the block. The signal level correction unit 30 determines whether the deterioration risk calculated in step ST13 is the maximum deterioration risk in the block having the block number to which the selected pixel belongs. The signal level correction unit 30 proceeds to step ST15 when the degradation risk calculated in step ST13 is the maximum degradation risk, and proceeds to step ST16 when it is not the maximum degradation risk, that is, when it is smaller than the maximum degradation risk.

In step ST15, the signal level correction unit 30 updates the maximum deterioration risk of the block. The signal level correction unit 30 proceeds to step ST16 with the maximum risk of deterioration of the block as the risk of deterioration calculated in step ST13.

In step ST16, the signal level correction unit 30 determines whether all the pixels have been selected. If the selection of all the pixels in the screen has not been completed, the signal level correction unit 30 returns to step ST11, selects a new pixel from the unselected pixels, and performs the above-described processing. Moreover, the signal level correction | amendment part 30 complete | finishes a degradation risk degree calculation process, when selection of all the pixels in a screen is completed.

Returning to FIG. 13, when the block deterioration risk is calculated in step ST2 and the process proceeds to step ST3, the signal level correction unit 30 updates the accumulated block deterioration risk. FIG. 15 is a flowchart showing the cumulative block deterioration risk update process.

In step ST21, the signal level correction unit 30 selects a block. The signal level correction unit 30 selects a block whose degradation risk is to be updated, and proceeds to step ST22.

In step ST22, the signal level correction unit 30 acquires the cumulative block deterioration risk. For example, the signal level correction unit 30 reads the cumulative block deterioration risk corresponding to the block selected in step ST21 from the block risk storage unit 401 of the storage unit 40, and proceeds to step ST23.

In step ST23, the signal level correction unit 30 acquires the block deterioration risk level of the current frame. The signal level correction unit 30 acquires the block deterioration risk calculated in the current frame for the block selected in step ST21, and proceeds to step ST24.

In step ST24, the signal level correction unit 30 updates the cumulative block deterioration risk. The signal level correction unit 30 adds the block deterioration risk of the current frame acquired in step ST23 to the cumulative block deterioration risk acquired in step ST22, thereby updating the cumulative block deterioration risk and proceeds to step ST25.

In step ST25, the signal level correction unit 30 stores the updated cumulative block deterioration risk. The signal level correction unit 30 stores the updated cumulative block deterioration risk obtained in step ST24 in the block risk storage unit 401 of the storage unit 40, for example, so that the stored cumulative block deterioration risk is stored. Update and proceed to step ST26.

In step ST26, the signal level correction unit 30 determines whether all blocks have been selected. If the selection of all the blocks in the screen has not been completed, the signal level correction unit 30 returns to step ST21, selects a new block from the unselected blocks, and performs the above-described processing. In addition, when the selection of all the blocks in the screen is completed, the signal level correcting unit 30 ends the cumulative block deterioration risk update process.

Returning to FIG. 13, when the cumulative block deterioration risk is updated in step ST3 and the process proceeds to step ST4, the signal level correction unit 30 calculates the area deterioration risk. The signal level correction unit 30 performs a process of dividing the entire display screen of the panel 65 into areas composed of one or a plurality of blocks and calculating the area deterioration risk based on the block deterioration risk for each area. FIG. 16 is a flowchart showing the area deterioration risk calculation processing.

In step ST31, the signal level correction unit 30 selects a block. The signal level correction unit 30 selects a block to calculate the area deterioration risk and proceeds to step ST32.

In step ST32, the signal level correction unit 30 calculates the area number to which the block belongs. Based on the block position of the block selected in step ST31, the signal level correction unit 30 calculates the number of the area to which the block belongs, and proceeds to step ST33.

In step ST33, the signal level correction unit 30 acquires the cumulative block deterioration risk. The signal level correction unit 30 acquires the updated cumulative block deterioration risk for the block selected in step ST31, and proceeds to step ST34.

In step ST34, the signal level correction unit 30 determines whether or not the maximum degradation risk level of the area. The signal level correction unit 30 determines whether or not the cumulative block deterioration risk acquired in step ST33 is the maximum deterioration risk in the area of the area number to which the selected block belongs. The signal level correction unit 30 proceeds to step ST35 when the cumulative block deterioration risk acquired in step ST33 is the maximum deterioration risk, and proceeds to step ST36 when it is not the maximum deterioration risk, that is, when it is smaller than the maximum deterioration risk. move on.

In step ST35, the signal level correction unit 30 updates the maximum deterioration risk of the area. The signal level correction unit 30 proceeds to step ST36 with the maximum risk of deterioration of the area as the cumulative block deterioration risk acquired in step ST33.

In step ST36, the signal level correction unit 30 determines whether all blocks have been selected. If the selection of all blocks in the screen has not been completed, the signal level correction unit 30 returns to step ST31, selects a new block from the unselected blocks, and performs the above-described processing. Moreover, the signal level correction | amendment part 30 complete | finishes an area degradation risk degree calculation process, when selection of all the blocks in a screen is completed.

Returning to FIG. 13, when the area deterioration risk is calculated in step ST4 and the process proceeds to step ST5, the signal level correction unit 30 updates the accumulated area deterioration risk. The signal level correction unit 30 performs a process similar to the process for updating the cumulative block deterioration risk in FIG. 15 for each area, updates the cumulative area deterioration risk, and proceeds to step ST6.

In step ST6, the signal level correction unit 30 calculates the deterioration risk for each pixel. The signal level correction unit 30 performs the calculations of Expressions (5) to (8), calculates the deterioration risk for each pixel from the updated area deterioration risk for each area, and proceeds to step ST7.

In step ST7, the signal level correction unit 30 calculates a correction gain for each pixel. The signal level correction unit 30 calculates a correction gain for each pixel according to the deterioration risk calculated for each pixel. FIG. 17 is a flowchart showing a correction gain calculation process.

In step ST41, the signal level correction unit 30 selects a pixel. The signal level correction unit 30 selects a pixel for calculating the correction gain, and proceeds to step ST42.

In step ST42, the signal level correction unit 30 acquires the pixel deterioration risk level. The signal level correction unit 30 acquires the deterioration risk for the pixel selected in step ST41 from the deterioration risk for each pixel calculated in step ST6, and proceeds to step ST43.

In step ST43, the signal level correction unit 30 calculates a gain adjustment amount. The signal level correction unit 30 calculates the above-described equation (9), calculates the gain adjustment amount according to the pixel deterioration risk level, and proceeds to step ST44.

In step ST44, the signal level correction unit 30 calculates a correction gain. The signal level correction unit 30 calculates the above-described equation (11), calculates a correction gain according to the luminance of the pixel selected in step ST41, and proceeds to step ST45.

In step ST45, the signal level correction unit 30 determines whether all the pixels have been selected. If the selection of all the pixels in the screen has not been completed, the signal level correction unit 30 returns to step ST41 and performs a process of newly selecting a pixel from the unselected pixels and determining the gain. Moreover, the signal level correction | amendment part 30 complete | finishes a correction gain calculation process, when selection of all the pixels in a screen is completed.

Returning to FIG. 13, when the correction gain is calculated in step ST7 and the process proceeds to step ST8, the signal level correction unit 30 corrects the signal level of the video signal. The signal level correction unit 30 corrects the signal level of the video signal for each pixel with the calculated correction gain.

According to the first embodiment, the degradation risk for each region calculated from the light emission amount of the pixels in the region is accumulated for each region, and based on the accumulated degradation risk for each region. A correction gain is calculated according to the calculated deterioration risk of each pixel and the luminance for each pixel. For this reason, a region not including a pixel having a high degree of deterioration has a lower risk of deterioration than a region including a pixel having a high degree of deterioration, and a pixel in a region not including a pixel having a high degree of deterioration includes a pixel having a high degree of deterioration. As in the case of the pixels in the area, the luminance is not lowered. Therefore, high visibility can be realized. In addition, luminance control is performed according to the degree of deterioration risk, and for example, for a pixel with a large degree of deterioration, the amount of light emission is reduced to suppress deterioration, so that the life of the light emitting element can be extended.

The area is composed of one or a plurality of blocks, and the area deterioration risk is calculated using the cumulative block deterioration risk calculated for the blocks in the area. Therefore, for example, even when the area is large, the area deterioration risk can be calculated according to the deterioration risk for each display range of the block size.

<3. Second Embodiment>
Next, a second embodiment of the present technology will be described. In recent years, mobile communication terminals such as smartphones and tablets that have been widely used have similar screen configurations according to usage. For example, in a mobile communication terminal, as shown in FIG. 18, a display area in which a status state is displayed and a display area in which various information and contents are displayed are divided. Therefore, in the second embodiment, the luminance control is performed in accordance with the proportion of usage of the display screen used by the user on the display device 10, thereby extending the lifetime of the light emitting element. A case where high visibility of display is realized will be described.

FIG. 19 illustrates the configuration of the second embodiment of the present technology. In the second embodiment, the signal level correction unit 30 in the signal processing unit 20 includes a luminance calculation unit 301, a light emission amount calculation unit 302, a block risk level calculation unit 303, a block risk level update unit 304, and an area risk level calculation unit. 305, an area risk update unit 306, a gain calculation unit 308, and a multiplier 390. The storage unit 40 includes a block risk storage unit 401, an area risk storage unit 402, and a target gain map storage unit 403.

The luminance calculation unit 301 calculates the luminance Y from the video signal having the linear characteristic converted by the linear conversion unit 23, and outputs the calculated luminance Y to the light emission amount calculation unit 302 and the gain calculation unit 308.

The light emission amount calculation unit 302 calculates the light emission amount E of each pixel of the panel 65 per frame based on the luminance Y calculated by the luminance calculation unit 301 and the duty ratio DR of the pulse calculated by the light emission time control unit 28. . The light emission amount calculation unit 302 outputs the calculated light emission amount E to the block risk degree calculation unit 303.

The block risk degree calculation unit 303 divides the entire display screen into a plurality of blocks, and calculates a deterioration risk degree for each pixel constituting the block based on the light emission amount calculated by the light emission amount calculation unit 302. In addition, the block risk level calculation unit 303 selects the maximum value from the deterioration risk level of each pixel in the block, and outputs the selected deterioration risk level to the block risk level update unit 304 as the block deterioration risk level.

The block risk update unit 304 updates the accumulated block deterioration risk by using the block deterioration risk calculated by the block risk calculation unit 303 for each block, and sets the updated cumulative block risk to the area risk level. It outputs to the calculation part 305. The block risk update unit 304 stores the updated cumulative block deterioration risk in the block risk storage unit 401 of the storage unit 40, and updates the cumulative block risk each time the block deterioration risk is calculated. It can be so.

The area risk level calculation unit 305 divides the entire display screen into areas composed of one or a plurality of blocks, and selects the maximum value in the area from the accumulated block deterioration risk level dgr_b calculated for the blocks constituting the area. . The area risk level calculation unit 305 sets the selected cumulative block deterioration risk level as the area deterioration risk level dgr_af. The area risk level calculation unit 305 outputs the area deterioration risk level dgr_af calculated for each area to the area risk level update unit 306.

The area risk update unit 306 updates the accumulated area deterioration risk using the area deterioration risk calculated by the area risk calculation unit 305 for each area, and the updated accumulated area risk is calculated as a gain calculation unit. Output to 308. Also, the area risk update unit 306 stores the updated accumulated area deterioration risk in the area risk degree storage unit 402 of the storage unit 40 and updates the accumulated area risk every time the area deterioration risk is calculated. It can be so.

The gain calculation unit 308 calculates a correction gain for correcting the signal level of the video signal by the multiplier 390. The gain calculation unit 308 includes the luminance output from the luminance calculation unit 301, the cumulative area deterioration risk dgr_a output from the area risk update unit 306, and the target gain stored in the target gain map storage unit 403 of the storage unit 40. A correction gain is calculated based on the map.

The multiplier 390 corrects and outputs the signal level of the video signal by multiplying the video signal by the correction gain calculated by the gain calculation unit 308.

The target gain map stored in the target gain map storage unit 403 of the storage unit 40 is created by the target gain map creation unit 70. The target gain map creating unit 70 creates a target gain map in advance by offline processing. The target gain map creation unit 70 may be provided in, for example, the signal processing unit 20 of the display device 10 or may be configured separately from the display device 10.

FIG. 20 illustrates the configuration of the target gain map creation unit. The target gain map creation unit 70 includes a user profile storage unit 701, a sample image DB (database) 702, a calculation image DB (database) creation unit 703, and a calculation image DB (database) 704. The target gain map creation unit 70 includes an image selection unit 761, a luminance calculation unit 762, a light emission amount calculation unit 764, a cumulative light emission amount update unit 765, a cumulative light emission amount storage unit 766, a light emitting element deterioration characteristic storage unit 767, a target gain. A calculation unit 768 and a target gain integration unit 769 are provided. Note that the user profile storage unit 701 to the target gain calculation unit 768 correspond to a target gain calculation processing unit in the claims.

The user profile storage unit 701 stores information indicating what kind of application image display is being performed at what rate on the display device. FIG. 21 illustrates a user profile when the display device is used in a smartphone. In FIG. 21, in a predetermined period (for example, a period of one day), the ratio of telephone display (Call) is 20%, the ratio of e-mail display (Email) is 20 modes, and the ratio of browser display (Browsing) is 20%. The ratio of the music playback display (Music) is 10% or the like.

The sample image DB 702 stores a large number of various sample images classified by use, such as user profile uses such as telephone display, e-mail display, browser display, and music playback display. In the display device, since the signal level correction unit corrects the video signal converted into the linear characteristic by the linear conversion unit 23 as described above, the linear characteristic sample image is stored in the sample image DB 702. Is done.

Based on the user profile stored in the user profile storage unit 701, the calculation image DB creation unit 703 selects a sample image for each usage indicated by the user profile from the sample image DB 702 at a usage ratio in the user profile. .

The calculation image DB 704 stores sample images selected based on the user profile.

The image selection unit 761 randomly selects an image stored in the calculation image DB 704 and outputs the image to the luminance calculation unit 762.

The luminance calculation unit 762 calculates the luminance Y from the video signal of the image selected by the image selection unit 761 in the same manner as the luminance calculation unit 301, and outputs the calculated luminance Y to the light emission amount calculation unit 764.

The light emission amount calculation unit 764 calculates the light emission amount Emit_f of each pixel of the panel 65 per frame based on the luminance Y calculated by the luminance calculation unit 762 and the panel drive duty ratio DR. The light emission amount calculation unit 764 outputs the calculated light emission amount Emit_f to the cumulative light emission amount update unit 765.

The cumulative light emission amount update unit 765 adds the multiplication result of the coefficient Ktm and the light emission amount Emit_f calculated by the light emission amount calculation unit 764 to the cumulative light emission amount Emit stored in the cumulative light emission amount storage unit 766 for each pixel. And output to the target gain calculator 768. Further, the cumulative light emission amount update unit 765 updates the cumulative light emission amount Emit of the cumulative light emission amount storage unit 766 with the addition result. Expression (12) indicates processing performed by the cumulative light emission amount update unit 765. In Equation (12), the coefficient Ktm (> 0) is a unit time parameter. For example, the coefficient Ktm is a parameter for setting a simulation result using fewer sample images than a predetermined frame as a simulation result for a predetermined frame when it is difficult to prepare a sample image for a predetermined frame when performing a simulation for a predetermined frame. It is.

Further, the cumulative light emission amount update unit 765 stores the light emission amount after addition in the cumulative light emission amount storage unit 766 as the updated cumulative light emission amount Emit.

In the light emitting element deterioration characteristic storage unit 767, information regarding the deterioration characteristic of the panel 65 is stored. FIG. 22 illustrates the relationship between the accumulated light emission amount and the luminance decrease amount, and the luminance decrease amount increases as the cumulative light emission amount increases. In addition, the cumulative light emission amount that becomes the maximum allowable luminance decrease amount (allowable maximum luminance decrease amount) in the panel 65 is set as a target cumulative light emission amount Emit_target.

The target gain calculation unit 768 calculates the target gain gain_t0 based on Expression (13) so that the cumulative light emission amount Emit updated by the cumulative light emission amount update unit 765 does not exceed the target cumulative light emission amount Emit_target for each pixel. Here, when the cumulative light emission amount Emit is equal to or less than the target cumulative light emission amount Emit_target, the target gain gain_t0 is “1”. When the cumulative light emission amount Emit exceeds the target cumulative light emission amount Emit_target, the target gain gain_t0 becomes a smaller value as the cumulative light emission amount Emit becomes larger than the target cumulative light emission amount Emit_target. In other words, the target gain gain_t0 is small for pixels where the luminance is frequently increased in the usage state of the user, and the target gain gain_t0 is “1” for pixels where the frequency is often low.

The target gain integration unit 769 integrates the target gain obtained for each pixel. For example, the target gain integration unit 769 integrates the target gains for each area for which the cumulative area deterioration risk is calculated by the area risk update unit 306 described above, and sets the minimum target gain in the area as the target gain gain_ta for this area. And Further, the target gain integration unit 769 calculates a target gain gain_ta for each area, and creates a target gain map indicating the target gain gain_ta of each area of the entire display screen. In addition, the target gain integration unit 769 integrates the target gain in units of blocks for which the risk of deterioration has been calculated by the block risk update unit 304 described above, and creates a target gain map indicating the target gain of each block on the entire display screen. May be. Thus, if the target gains are integrated, the data amount of the target gain map can be reduced. The target gain integration unit 769 may create a target gain map indicating the target gain of each pixel for each pixel of the entire display screen. The target gain integration unit 769 stores the created target gain map in the target gain map storage unit 403 of the storage unit 40.

The gain calculation unit 308 shown in FIG. 19 calculates a gain adjustment amount gainC for correcting the signal level of the video signal by the multiplier 390. The gain calculation unit 308 stores, for each pixel, the luminance output from the luminance calculation unit 301, the accumulated area deterioration risk dgr_a output from the area risk update unit 306, and the target gain map storage unit 403 of the storage unit 40. A gain adjustment amount gainC is calculated based on the target gain map.

The gain calculation unit 308 replaces the maximum gain gain_max of the gain calculation unit 307 in the first embodiment with the maximum gain (1-gain_t) calculated using the target gain gain_t of the corresponding pixel position in the target gain map. Also, the gain calculation unit 308 calculates the gain adjustment amount gainC using the maximum gain gain_max = (1−gain_t) calculated using the target gain gain_t. That is, the gain calculation unit 308 calculates the gain adjustment amount based on the target gain gain_t so that the decrease in luminance is large in the pixels in the region where the light emitting element is likely to deteriorate. FIG. 23 is a diagram showing the relationship between the deterioration risk and the gain adjustment amount.

Also, the gain calculation unit 308 calculates a correction gain characteristic based on the calculated gain adjustment amount gainC, similarly to the gain calculation unit 307. Furthermore, the gain calculation unit 308 outputs the correction gain gain_p obtained according to the luminance of the pixel p based on the correction gain characteristic to the multiplier 390. The gain calculation unit 308 performs the same process on other pixels and outputs a correction gain corresponding to the luminance of each pixel to the multiplier 390. Multiplier 390 multiplies the video signal by the correction gain calculated by gain calculation section 308 and outputs the result.

Here, when the cumulative light emission amount Emit exceeds the target cumulative light emission amount Emit_target, the target gain gain_t becomes a smaller value as the cumulative light emission amount Emit becomes larger than the target cumulative light emission amount Emit_target. Accordingly, as the cumulative light emission amount Emit becomes larger than the target cumulative light emission amount Emit_target, the maximum gain (1-gain_t) approaches “1”, so that the cumulative light emission amount Emit is less than or equal to the target cumulative light emission amount Emit_target. Also, the minimum value of the correction gain can be reduced. That is, since it is possible to increase the decrease in luminance and reduce the accumulated light emission amount, it is possible to perform luminance control so that the accumulated light emission amount is equal to or less than the target accumulated light emission amount. Further, when the cumulative light emission amount Emit is equal to or less than the target cumulative light emission amount Emit_target, the target gain gain_t is “1”, and thus the gain adjustment amount gainC is “0”. That is, it is possible to prevent the luminance from being reduced for pixels whose cumulative light emission amount Emit has not reached the target cumulative light emission amount Emit_target.

In the second embodiment, the operation of the flowchart shown in FIG. 13 is performed in the same manner as in the first embodiment. In the second embodiment, in the calculation of the correction gain for each pixel in step ST5, the correction gain is calculated using the target gain map.

FIG. 24 is a flowchart showing a target gain map creation operation. In step ST51, the target gain map creation unit 70 creates a calculation image DB (database). The target gain map creation unit 70 sets the usage ratio for each usage indicated by the user profile based on the user profile indicating what usage the image display is performed by the user on the display device. Select a sample image accordingly. The target gain map creation unit 70 creates a calculation image DB made up of the selected sample images, and proceeds to step ST52.

In step ST52, the target gain map creation unit 70 selects an image. The target gain map creation unit 70 selects an image at random from the calculation image DB, and proceeds to step ST53.

In step ST53, the target gain map creation unit 70 calculates the light emission amount. The target gain map creation unit 70 calculates the light emission amount for each pixel based on the luminance and duty ratio of the selected image, and proceeds to step ST54.

In step ST54, the target gain map creating unit 70 calculates the accumulated light emission amount. The target gain map creation unit 70 accumulates the light emission amount calculated from the selected image every time the image is selected, calculates the accumulated light emission amount, and proceeds to step ST55.

In step ST55, the target gain map creation unit 70 determines whether or not the accumulation for a predetermined number of images has been completed. The target gain map creation unit 70 returns to step ST52 when the accumulated amount of light emission has not reached the predetermined number of images, and proceeds to step ST56 when the predetermined number of images has been reached.

In step ST56, the target gain map creating unit 70 calculates target gains for all pixels. The target gain map creating unit 70 calculates the target gain so that the cumulative light emission amount does not exceed the target cumulative light emission amount for each pixel, and the process proceeds to step ST57.

In step ST57, the target gain map creating unit 70 creates a target gain map. The target gain map creating unit 70 creates a target gain map indicating the target gain for each pixel position using the target gain calculated for each pixel, and ends the process.

According to the second embodiment as described above, the degradation risk for each region calculated from the light emission amount of the pixels in the region is accumulated for each region, and based on the accumulated degradation risk for each region. A deterioration risk for each pixel is calculated. In addition, a target gain map is created according to what percentage of the display screen the user uses on the display device 10, and the degree of degradation risk for each pixel, the luminance for each pixel, and the target gain. A correction gain is calculated according to the gain of the map. For this reason, as in the first embodiment, it is possible to realize a long life of the light emitting element and high visibility of display. Furthermore, in the second embodiment, since the correction gain is calculated according to the usage situation of the user, the extension of the life of the light emitting element and the realization of the high visibility of the display are optimized according to the usage situation of the user. It can be carried out.

<4. Third Embodiment>
Next, a third embodiment of the present technology will be described. In the third embodiment, the signal processing unit is configured similarly to the second embodiment shown in FIG. Further, in the third embodiment, a case will be described in which the luminance reduction speed adjustment is performed according to what ratio the display screen of the user uses on the display device 10 at what rate.

The gain calculation unit 308 of the signal processing unit 20 calculates a gain adjustment amount gainC for correcting the signal level of the video signal by the multiplier 390. The gain calculation unit 308 is, for each pixel, based on the luminance output from the luminance calculation unit 301, the cumulative area deterioration risk dgr_a output from the area risk level update unit 306, and the target gain map in the target gain map storage unit 403. The gain adjustment amount gainC is calculated.

FIG. 25 shows the relationship between the risk of deterioration and the amount of gain adjustment. The gain calculation unit 308 sets thresholds ThDgr0c and ThDrg1c based on equations (14) and (15). The coefficient gm0 is a parameter that adjusts the value of the deterioration risk at which gain adjustment is started, and the coefficient gm1 is a parameter that adjusts the value of the deterioration risk that maximizes the gain adjustment amount. Further, the coefficients gm0 and gm1 are set in the relationship of Expression (16) so that the threshold ThDgr0c does not become larger than ThDrg1c.

Here, when the cumulative light emission amount Emit exceeds the target cumulative light emission amount Emit_target, the target gain gain_t becomes a smaller value as the cumulative light emission amount Emit becomes larger than the target cumulative light emission amount Emit_target. Therefore, since the threshold values ThDgr0c and ThDrg1c are smaller than the threshold values ThDgr0 and ThDrg1, the luminance control is performed even if the deterioration risk is small. Further, by adjusting the coefficients gm0 and gm1, the relationship between the degree of risk of deterioration and the amount of adjustment of luminance can be set to a desired characteristic. For example, the gain calculation unit 308 adjusts the coefficients gm0 and gm1 and the threshold values ThDgr0 and ThDrg1, and calculates the gain adjustment amount gainC so as to reduce the luminance of the pixel from the region where the deterioration of the light emitting element is small based on the target gain. Alternatively, the gain adjustment amount gainC can be calculated so that the luminance is quickly reduced in a pixel in a region where the light emitting element is likely to deteriorate based on the target gain.

According to the third embodiment, the degradation risk for each region calculated from the light emission amount of the pixels in the region is accumulated for each region, and based on the accumulated degradation risk for each region. A deterioration risk for each pixel is calculated. In addition, a target gain map is created according to what percentage of the display screen the user uses on the display device 10, and the degree of degradation risk for each pixel, the luminance for each pixel, and the target gain. A correction gain is calculated according to the gain of the map. Furthermore, a gain adjustment amount corresponding to the degree of deterioration risk is calculated according to the usage status of the user. For this reason, as in the first embodiment, it is possible to realize a long life of the light emitting element and high visibility of display. Further, as in the second embodiment, since the correction gain is calculated according to the usage situation of the user, the lifetime of the light emitting element and the realization of the high visibility of the display are realized according to the usage situation of the user. Can be done optimally. Furthermore, in the third embodiment, since the gain adjustment amount according to the degree of deterioration risk can be calculated according to the usage situation of the user and the like, the life of the light emitting element and the realization of high visibility of the display can be realized by the user. It can be performed more optimally depending on the situation.

<5. Fourth Embodiment>
Next, a fourth embodiment of the present technology will be described. In the fourth embodiment, a case where a correction gain is calculated according to an application that displays an image on a display device will be described. FIG. 26 illustrates the configuration of the fourth embodiment of the present technology.

In the fourth embodiment, the signal level correction unit 30 in the signal processing unit 20 includes a luminance calculation unit 301, a light emission amount calculation unit 302, a block risk level calculation unit 303, a block risk level update unit 304, and an area risk level calculation unit. 305, an area risk update unit 306, a gain calculation unit 309, and a multiplier 390. The storage unit 40 includes a block risk storage unit 401, an area risk storage unit 402, and an application target gain map storage unit 404.

The gain calculation unit 308 calculates a correction gain for correcting the signal level of the video signal by the multiplier 390. The gain calculation unit 308 performs correction based on the luminance output from the luminance calculation unit 301, the cumulative area deterioration risk dgr_a output from the area risk update unit 306, and the application target gain map in the application target gain map storage unit 404. Calculate the gain.

Multiplier 390 multiplies the video signal by the correction gain calculated by gain calculation section 308 and outputs the result.

The application target gain map storage unit 404 of the storage unit 40 stores a target gain map selected according to an application that displays an image on the display device. The target gain map is created by the application-specific target gain map creation unit 71. The application-specific target gain map creation unit 71 creates a target gain map for each application in advance by offline processing and stores it in the application-specific target gain map storage unit 72. The target gain map selection unit 73 acquires a target gain map corresponding to an application for displaying an image on the display device from the application-specific target gain map storage unit 72 and stores it in the application target gain map storage unit 404 of the storage unit 40. . The application-specific target gain map creation unit 71 may be provided, for example, in the signal processing unit 20 of the display device 10 or may be configured separately from the display device 10.

FIG. 27 shows the configuration of the application-specific target gain map creation unit. The application-specific target gain map creation unit 71 includes an application-specific image DB (database) 705, an image selection unit 761, a luminance calculation unit 762, a light emission amount calculation unit 764, a cumulative light emission amount update unit 765, a cumulative light emission amount storage unit 766, and a light emission. An element deterioration characteristic storage unit 767, a target gain calculation unit 768, and a target gain integration unit 769 are provided. The application-specific image DB 705 to the target gain calculation unit 768 correspond to a target gain calculation processing unit in claims.

The application-specific image DB 705 stores many sample images for each application. In the display device, since the signal level correction unit corrects the video signal converted into the linear characteristic by the linear conversion unit 23 as described above, the linear characteristic sample image is stored in the application-specific image DB 705. Remembered.

The image selection unit 761 randomly selects an image stored in the application-specific image DB 705 and outputs the image to the luminance calculation unit 762 for each application.

The cumulative light emission amount updating unit 765 adds the cumulative light emission amount Emit stored in the cumulative light emission amount storage unit 766 to the light emission amount Emit_f calculated by the light emission amount calculation unit 764 for each pixel, and thereby the target gain calculation unit 768. Output to. In addition, the accumulated light amount update unit 765 stores the added light amount in the accumulated light amount storage unit 766 as the updated accumulated light amount Emit.

In the light emitting element deterioration characteristic storage unit 767, information related to the deterioration characteristic of the panel 65 is stored. The target gain calculation unit 768 calculates a target gain for each pixel based on the accumulated light emission amount and the target accumulated light emission amount. The target accumulated light emission amount is set based on the target luminance decrease amount and the deterioration characteristic stored in the light emitting element deterioration characteristic storage unit 767.

The target gain calculation unit 768 calculates the target gain gain_t0 based on the above equation (13) so that the cumulative light emission amount Emit updated by the cumulative light emission amount update unit 765 does not exceed the target cumulative light emission amount Emit_target for each pixel. To do. The target gain calculation unit 768 outputs the calculated target gain gain_t0 to the target gain integration unit 769.

The target gain integration unit 769 integrates the target gain obtained for each pixel. For example, the target gain integration unit 769 integrates target gains in units of areas for which the risk of deterioration has been calculated by the area risk update unit 306 described above, and sets the minimum target gain in the area as the target gain gain_ta of this area. . Further, the target gain integration unit 769 calculates a target gain gain_ta for each area, and creates a target gain map indicating the target gain gain_ta of each area of the entire display screen. In addition, the target gain integration unit 769 integrates target gains in units of blocks for which the risk of deterioration has been calculated by the block risk update unit 304 described above, and generates a target gain map indicating the target gain gain_ta of each block on the entire display screen. You may create it. Thus, if the target gains are integrated, the data amount of the target gain map can be reduced. In addition, the target gain integration unit 769 may create a target gain map indicating the target gain gain_t0 of each pixel for each pixel of the entire display screen.

The luminance calculation unit 762 through the target gain integration unit 769 create the target gain map for each application by performing the above-described processing for each application, and store the target gain map in the application-specific target gain map storage unit 72 illustrated in FIG. .

The target gain map selection unit 73 acquires a target gain map corresponding to the application that is operating using the display device from the application-specific target gain map storage unit 72, and the application target gain map storage unit of the storage unit 40 Store in 404.

A gain calculation unit 309 shown in FIG. 26 calculates a correction gain for correcting the signal level of the video signal by the multiplier 390. The gain calculation unit 309 is, for each pixel, based on the luminance output from the luminance calculation unit 301, the cumulative area deterioration risk output from the area risk level update unit 306, and the target gain map in the application target gain map storage unit 404. The correction gain is calculated in the same manner as in the second or third embodiment described above.

In the fourth embodiment, the operation of the flowchart shown in FIG. 13 is performed in the same manner as in the first embodiment. Further, in the fourth embodiment, a target gain map corresponding to an application that is operated using the display device is used in the calculation of the correction gain for each pixel in step ST5.

FIG. 28 is a flowchart showing target gain map selection processing. In step ST61, the target gain map selection unit 73 receives an application switching command. The target gain map selection unit 73 receives the application switching command output from the control unit 11, and proceeds to step ST62.

In step ST62, the target gain map selection unit 73 acquires the application name. The target gain map selection unit 73 acquires the switched application name indicated by the received application switching command, and proceeds to step ST63.

In step ST63, the target gain map selection unit 73 acquires a target gain map corresponding to the application name. The target gain map selection unit 73 acquires the target gain map corresponding to the acquired application name from the application-specific target gain map storage unit 72, and proceeds to step ST64.

In step ST64, the target gain map selection unit 73 outputs the target gain map. The target gain map selection unit 73 stores the target gain map acquired from the application-specific target gain map storage unit 72 in the application target gain map storage unit 404 and ends the process.

According to the fourth embodiment, the deterioration risk for each area calculated from the light emission amount of the pixels in the area is accumulated for each area, and based on the accumulated deterioration risk for each area. A deterioration risk for each pixel is calculated. Further, the correction gain is calculated according to the deterioration risk for each pixel, the luminance for each pixel, and the gain of the target gain map corresponding to the application used by the user. For this reason, as in the first embodiment, it is possible to realize a long life of the light emitting element and high visibility of display. Furthermore, in the fourth embodiment, since the correction gain is calculated according to the application being used, it is possible to optimally achieve a long life of the light emitting element and high visibility of the display.

<6. Fifth embodiment>
Next, a fifth embodiment of the present technology will be described. In the fifth embodiment, a case where a target gain map is acquired via a network or the like will be described. When the panel 65 that has not been used for a long time is used, the signal level is adjusted according to the deterioration characteristics estimated by the deterioration acceleration test or the like. For this reason, if the estimated deterioration characteristic is different from the actual deterioration characteristic, the luminance control of the video signal cannot be accurately performed according to the deterioration characteristic of the panel 65. In addition, when time elapses since the sale of the device using the display device, detailed deterioration characteristics become clear from the measured values of the characteristics of the panel 65 and the like. Therefore, in the fifth embodiment, a case will be described in which the display device acquires a target gain map via a network or the like so that the signal level can be corrected according to the clarified deterioration characteristic.

FIG. 29 illustrates the configuration of the fifth embodiment. In the fifth embodiment, the signal level correction unit 30 in the signal processing unit 20 includes a luminance calculation unit 301, a light emission amount calculation unit 302, a block risk level calculation unit 303, a block risk level update unit 304, and an area risk level calculation unit. 305, an area risk update unit 306, a gain calculation unit 310, and a multiplier 390. The storage unit 40 includes a block risk storage unit 401, an area risk storage unit 402, and a target gain map storage unit 405.

The gain calculation unit 310 calculates a correction gain for correcting the signal level of the video signal by the multiplier 390. For each pixel, the gain calculation unit 310 is based on the luminance output from the luminance calculation unit 301, the cumulative area deterioration risk output from the area risk level update unit 306, and the target gain map in the target gain map storage unit 405. Calculate the correction gain.

Multiplier 390 multiplies the video signal by the correction gain calculated by gain calculation section 310 and outputs the result.

The target gain map storage unit 405 of the storage unit 40 is connected to the network, acquires the target gain map created by the external target gain map creation unit via the network, and stores the target gain map. Update. Note that the target gain map acquired via the network may be a target gain map for each application as in the fourth embodiment. The target gain map storage unit 405 notifies the user profile to the target gain map creation unit via the network, and the target gain created corresponding to the user profile as in the second and third embodiments. A map may be acquired.

FIG. 30 illustrates a configuration when the target gain map creation unit is mounted on the display device. For example, as shown in FIG. 22, the target gain map creation unit 74 acquires an actual deterioration characteristic indicating the relationship between the accumulated light emission amount and the luminance reduction amount due to deterioration, and the target gain map is based on the acquired deterioration characteristic. And is stored in the target gain map storage unit 405. Further, the target gain map creation unit 74 acquires, for example, a sample image corresponding to the application via the network, and displays an image at a ratio of the use of the user profile for each application indicated by the user profile from the acquired sample image. The accumulated light emission amount may be calculated by selection. Furthermore, the target gain map creation unit 74 may acquire, for example, a user profile via a network.

FIG. 31 illustrates the configuration of the target gain map creation unit. The target gain map creation unit 74 includes a user profile storage unit 701, a sample image DB 712, a calculation image DB (database) creation unit 703, and a calculation image DB (database) 704. The target gain map creation unit 74 includes an image selection unit 761, a luminance calculation unit 762, a light emission amount calculation unit 764, a cumulative light emission amount update unit 765, a cumulative light emission amount storage unit 766, a target gain calculation unit 768, and a light emitting element deterioration characteristic. A storage unit 777 and a target gain integration unit 769 are provided.

The user profile storage unit 701 stores information indicating what kind of application image display is being performed at what rate on the display device as a user profile. The user profile storage unit 701 can be supplied with a user profile and updated from the external device via a network.

The sample image DB 712 stores sample images for each use of the user profile. In addition, for the sample image DB 712, it is possible to supply a sample image and update the sample image from an external device via a network. In the display device, since the signal level correction unit corrects the video signal converted into the linear characteristic by the linear conversion unit 23 as described above, the sample image having the linear characteristic is stored in the sample image DB 712. Is done.

Based on the user profile stored in the user profile storage unit 701, the calculation image DB creation unit 703 selects a sample image for each usage indicated by the user profile from the sample image DB 712 at a usage ratio in the user profile. .

The cumulative light emission amount update unit 765 multiplies the light emission amount Emit_f calculated by the light emission amount calculation unit 764 for each pixel by the above-described coefficient Ktm and the cumulative light emission amount Emit stored in the cumulative light emission amount storage unit 766. Are output to the target gain calculator 768. Further, the cumulative light emission amount update unit 765 updates the cumulative light emission amount Emit of the cumulative light emission amount storage unit 766 with the addition result.

In the light emitting element deterioration characteristic storage unit 777, information related to the deterioration characteristic of the panel 65 is stored. In addition, the deterioration characteristic stored in the light emitting element deterioration characteristic storage unit 777 can be updated to a deterioration characteristic acquired from an external device via a network.

The target gain calculation unit 768 calculates a target gain for each pixel based on the accumulated light emission amount and the target accumulated light emission amount. The target cumulative light emission amount is set based on the target luminance decrease amount and the deterioration characteristics stored in the light emitting element deterioration characteristic storage unit 777.

For each pixel, the target gain calculation unit 768 calculates the target gain gain_t0 so that the cumulative light emission amount Emit updated by the cumulative light emission amount update unit 765 does not exceed the target cumulative light emission amount Emit_target, and outputs the target gain gain_t0 to the target gain integration unit 769. To do.

The target gain integration unit 769 integrates the target gain obtained for each pixel. For example, the target gain integration unit 769 integrates the target gains for each area for which the cumulative area deterioration risk is calculated by the area risk update unit 306 described above, and sets the minimum target gain in the area as the target gain gain_ta for this area. And Further, the target gain integration unit 769 calculates a target gain gain_ta for each area, and creates a target gain map indicating the target gain gain_ta of each area of the entire screen.

In the fifth embodiment, the operation of the flowchart shown in FIG. 13 is performed in the same manner as in the first embodiment. In the fifth embodiment, in the calculation of the correction gain for each pixel in step ST7, the correction gain is obtained by using the target gain map created based on the sample image, the user profile, and the deterioration characteristic acquired via the network or the like. Is calculated. Note that the target gain map, the sample image, the user profile, and the deterioration characteristics are not limited to being acquired via a network, but may be acquired via a recording medium or the like.

As described above, according to the fifth embodiment, the risk of deterioration for each region calculated from the light emission amount of the pixels in the region is accumulated for each region, and based on the accumulated risk of deterioration for each region. A deterioration risk for each pixel is calculated. In addition, a target gain map is created according to what percentage of the display screen the user uses on the display device 10, and the degree of degradation risk for each pixel, the luminance for each pixel, and the target gain. A correction gain is calculated according to the gain of the map. Furthermore, the sample image, user profile, and deterioration characteristics used to create the target gain map can be easily updated to the optimum sample image, user profile, and highly accurate deterioration characteristics. For this reason, as in the first embodiment, it is possible to realize a long life of the light emitting element and high visibility of display. Furthermore, in the fifth embodiment, since the correction gain can be calculated according to the use situation of the user, the actual deterioration characteristics of the panel, etc., it is possible to extend the life of the light emitting element and realize high visibility of the display by the user. It can be performed more optimally depending on the situation.

<7. Sixth Embodiment>
Next, a sixth embodiment of the present technology will be described. In the sixth embodiment, a case will be described in which a target gain map creating unit is provided in the signal processing unit 20 and a target gain map is created by online processing in accordance with the driving state of the panel 65.

FIG. 32 illustrates the configuration of the target gain map creation unit in the sixth embodiment. The target gain map creation unit 76 includes a luminance calculation unit 763, a light emission amount calculation unit 764, a cumulative light emission amount update unit 765, a cumulative light emission amount storage unit 766, a light emitting element deterioration characteristic storage unit 767, a target gain calculation unit 768, and a target gain integration. Part 769.

The luminance calculation unit 763 calculates the luminance Y from the video signal corrected by the signal level correction unit 30 in the same manner as the luminance calculation unit 762, and outputs the calculated luminance Y to the light emission amount calculation unit 764.

The light emission amount calculation unit 764 calculates the light emission amount Emit_f of each pixel of the panel 65 per frame based on the luminance Y calculated by the luminance calculation unit 763 and the panel drive duty ratio DR. The light emission amount calculation unit 764 outputs the calculated light emission amount Emit_f to the cumulative light emission amount update unit 765.

In the light emitting element deterioration characteristic storage unit 767, information related to the deterioration characteristic of the panel 65 is stored.

The target gain calculation unit 768 calculates a target gain for each pixel based on the accumulated light emission amount and the target accumulated light emission amount. The target accumulated light emission amount is set based on the target luminance decrease amount and the deterioration characteristic stored in the light emitting element deterioration characteristic storage unit 767.

In the sixth embodiment, the operation of the flowchart shown in FIG. 13 is performed in the same manner as in the first embodiment. In the sixth embodiment, in the calculation of the correction gain for each pixel in step ST7, the correction gain is calculated using the target gain map created based on the video signal corrected by the signal level correction unit 30.

Thus, in the sixth embodiment, a target gain map is created according to the driving state of the panel 65. Therefore, the progress of the deterioration can be suppressed by further reducing the target gain for the pixel in which the panel 65 emits a large amount of light and the panel has been deteriorated. In addition, the visibility of the pixels in which the light emission amount of the panel 65 is small and the panel deterioration is small can be improved by increasing the target gain. Furthermore, in the sixth embodiment, for example, the light emission amount per day in the panel 65 may be controlled by performing the control on a daily basis. If a target gain map is created according to the driving state of the panel 65 from the first use of the display device, the correction gain can be calculated more accurately according to the deterioration state of the panel.

Thus, according to the sixth embodiment, the degradation risk for each region calculated from the light emission amount of the pixels in the region is accumulated for each region, and based on the accumulated degradation risk for each region. A deterioration risk for each pixel is calculated. Further, a target gain map is created according to the driving state of the panel, and a correction gain is calculated according to the degree of deterioration risk for each pixel, the luminance for each pixel, and the gain of the target gain map. For this reason, as in the first embodiment, it is possible to realize a long life of the light emitting element and high visibility of display. Furthermore, in the sixth embodiment, since the correction gain can be calculated according to the panel usage status, the life of the light emitting element and the high visibility of the display can be optimally performed according to the panel usage status. .

<8. Other embodiments>
The embodiments described above are not limited to being performed independently, and may be performed in combination. For example, the fourth embodiment may be performed in combination with at least one of the second to third embodiments. Further, the fifth embodiment may be performed in combination with at least one of the second to fourth embodiments. Alternatively, the sixth embodiment may be performed by combining at least one of the second to fourth embodiments with the sixth embodiment. As described above, by combining a plurality of embodiments, it is possible to more reliably achieve a longer lifetime of the light-emitting element and a higher display visibility than before the combination.

Further, the series of processes described in the specification can be executed by hardware, software, or a combined configuration of both. When processing by software is executed, a program in which a processing sequence is recorded is installed and executed in a memory in a computer incorporated in dedicated hardware. Alternatively, the program can be installed and executed on a general-purpose computer capable of executing various processes.

For example, the program can be recorded in advance on a hard disk, SSD (Solid State Drive), or ROM (Read Only Memory) as a recording medium. Alternatively, the program is a flexible disk, a CD-ROM (Compact Disc Read Only Memory), an MO (Magneto optical disc), a DVD (Digital Versatile Disc), a BD (Blu-Ray Disc (registered trademark)), a magnetic disk, or a semiconductor memory card. It can be stored (recorded) in a removable recording medium such as temporarily or permanently. Such a removable recording medium can be provided as so-called package software.

In addition to installing the program from the removable recording medium to the computer, the program may be transferred from the download site to the computer wirelessly or by wire via a network such as a LAN (Local Area Network) or the Internet. The computer can receive the program transferred in this way and install it on a recording medium such as a built-in hard disk.

It should be noted that the effects described in this specification are merely examples and are not limited, and there may be additional effects that are not described. Further, the present technology should not be construed as being limited to the embodiments of the technology described above. The embodiments of this technology disclose the present technology in the form of examples, and it is obvious that those skilled in the art can make modifications and substitutions of the embodiments without departing from the gist of the present technology. In other words, the scope of the claims should be considered in order to determine the gist of the present technology.

In addition, the video signal processing apparatus according to the present technology may have the following configuration.
(1) Cumulative degradation risk for calculating the degradation risk level by calculating the degradation risk level for each area of the display screen from the light emission amount for each pixel based on the video signal, and accumulating the calculated degradation risk level for each area. A degree calculator,
A gain calculation unit that calculates a deterioration risk for each pixel from the cumulative deterioration risk for each region, and calculates a correction gain for each pixel based on the deterioration risk for each pixel and the luminance for each pixel;
A video signal processing apparatus comprising: a correction unit that corrects a signal level of the video signal using the correction gain.
(2) The cumulative deterioration risk calculating unit calculates a cumulative block deterioration risk by accumulating the maximum deterioration risk of the pixels in the block for each of the regions including one or a plurality of blocks. (1). The video signal processing device according to (1), wherein the maximum accumulated block deterioration risk is accumulated to obtain a cumulative deterioration risk for each region.
(3) The gain calculation unit calculates the deterioration risk level of the pixel by using the cumulative deterioration risk level of the area including the pixel for calculating the deterioration risk level and the cumulative deterioration risk level of the area adjacent to the area. The video signal processing device according to (1) or (2) to be calculated.
(4) The gain calculation unit is configured so that each of the regions has a ratio according to a distance from a boundary between a region including the pixel for calculating the deterioration risk and an adjacent region to a pixel for calculating the deterioration risk. The video signal processing apparatus according to (3), wherein the deterioration risk level of the pixel is calculated using the cumulative deterioration risk level.
(5) The gain calculation unit calculates a gain adjustment amount for each pixel according to the degree of deterioration risk for each pixel, and calculates a correction gain based on the gain adjustment amount for each pixel and the luminance of the pixel ( The video signal processing device according to any one of 1) to (4).
(6) A target gain map storage unit that stores a target gain map in which a target gain that sets a light emitting element that emits light based on the video signal as an allowable luminance reduction amount is indicated for each pixel position;
The video signal processing device according to any one of (1) to (5), wherein the gain calculation unit calculates a correction gain for each pixel based on the degradation risk for each pixel, the luminance for each pixel, and the target gain.
(7) The target gain is set to the pixel position based on the cumulative light emission amount calculated for each pixel using the sample image according to the ratio of the display time for each application and the deterioration characteristics of the light emitting element that emits light based on the video signal. The video signal processing device according to (6), further comprising a target gain map creation unit configured to create a target gain map for each setting.
(8) The target gain map creation unit
A cumulative light emission amount for each pixel is calculated in accordance with the display time ratio for each application, and based on the cumulative light emission amount that is an allowable luminance reduction amount for the light emitting element and the cumulative light emission amount calculated for each pixel. A target gain calculation processing unit for calculating a target gain for each pixel;
The video signal processing device according to (7), further including a target gain integration unit that integrates the target gain calculated for each pixel for each region and calculates the target gain for each region.
(9) The video signal processing device according to (7), wherein the target gain map creation unit updates the sample image or the degradation characteristic to a sample image or degradation characteristic acquired from the outside.
(10) The gain calculation unit calculates a gain adjustment amount for each pixel according to the degree of deterioration risk for each pixel and the target gain, and a correction gain based on the gain adjustment amount for each pixel and the luminance of the pixel. The video signal processing device according to any one of (6) to (9).
(11) The video signal processing according to (10), wherein the gain calculation unit calculates a gain adjustment amount so that a deterioration degree of the light emitting element that lowers luminance of a pixel based on the target gain becomes a desired deterioration degree. apparatus.
(12) The gain calculation unit calculates a gain adjustment amount based on the target gain so that a decrease in luminance becomes a desired speed in a pixel in a region where the light emitting element is likely to deteriorate (10) or (11) 2. A video signal processing apparatus according to 1.
(13) The target gain map is set by setting the target gain for each pixel position based on the cumulative light emission amount calculated for each pixel based on the application image and the deterioration characteristics of the light emitting element that emits light based on the video signal. The video signal processing device according to any one of (6) to (12), further including a target gain map creation unit to create.
(14) The target gain map creation unit creates the target gain map for each application,
The video signal processing apparatus according to (13), wherein the gain calculation unit calculates the correction gain for each pixel using a target gain map of an application that matches the application of the video signal.
(15) The target gain map creation unit
For each application, a cumulative light emission amount for each pixel is calculated based on the image of the application, and based on a cumulative light emission amount that is an allowable luminance reduction amount for the light emitting element and a cumulative light emission amount calculated for each pixel. A target gain calculation processing unit for calculating a target gain for each pixel;
The video signal processing apparatus according to (13) or (14), further including a target gain integration unit that integrates the target gain calculated for each pixel for each region and calculates a target gain for each region.
(16) The video signal processing device according to any one of (7) and (13), wherein the target gain map storage unit updates the target gain map to a target gain map acquired from the outside.
(17) A target gain for creating the target gain map based on a cumulative light emission amount calculated for each pixel using the video signal corrected by the correction unit and a deterioration characteristic of a light emitting element that emits light based on the video signal. The video signal processing device according to (6), further including a map creation unit.

In the video signal processing apparatus and the video signal processing method of this technology, the risk of cumulative degradation is calculated by calculating the degradation risk for each area obtained by dividing the display screen from the light emission amount for each pixel based on the video signal, and accumulating it for each area. The degree is calculated by the cumulative deterioration risk calculation unit. Also, the deterioration risk for each pixel is calculated from the cumulative deterioration risk for each region, and a correction gain is calculated for each pixel by the gain calculation unit based on the deterioration risk for each pixel and the luminance for each pixel. Further, the signal level of the video signal is corrected by the correction unit using the correction gain. For this reason, the signal level of the video signal is adjusted so that the luminance is lower in the high degradation risk region than in the low degradation risk region, so that the lifetime of the light emitting element and the high visibility of the display can be realized. . Therefore, it is suitable for portable communication terminals, information processing devices, video display devices, and the like using organic EL elements that are self-luminous elements.

DESCRIPTION OF SYMBOLS 10 ... Display apparatus 20 ... Signal processing part 30 ... Signal level correction | amendment part 40 ... Memory | storage part 65 ...

Panel

70, 74, 76 ... Target gain map preparation part 71 ... Application Separate target gain map creation unit 72 ... Application specific target gain map storage unit 73 ... Target gain map selection unit 301 ... Luminance calculation unit 302 ... Light emission amount calculation unit 303 ... Block risk calculation unit 304 ... Block risk update unit 305 ... Area risk level calculation unit 306 ... Area risk

level update unit

307, 308, 309, 310 ... Gain calculation unit 390 ... Multiplier 401 ... Block risk storage unit 402 ... Area

risk storage unit

403, 405 ... Target gain map storage unit 404 ... Application target gain map storage unit 701 ... The

profile storage unit

702, 712 ... sample image DB
703: Calculation image DB creation unit 704: Calculation image DB
705 ... Application-specific image DB
761...

Image selection unit

762, 763 .. Luminance calculation unit 764... Light emission amount calculation unit 765... Cumulative light emission amount update unit 766... Cumulative light emission amount storage unit 767,777. Deterioration characteristic storage unit 768... Target gain calculation unit 769... Target gain integration unit

Claims

Accumulated degradation risk that calculates the degradation risk for each area obtained by dividing the display screen from the light emission amount for each pixel based on the video signal, and accumulates the calculated degradation risk for each area. A degree calculator,
A gain calculation unit that calculates a deterioration risk for each pixel from the cumulative deterioration risk for each region, and calculates a correction gain for each pixel based on the deterioration risk for each pixel and the luminance for each pixel;
A video signal processing apparatus comprising: a correction unit that corrects a signal level of the video signal using the correction gain.
The cumulative deterioration risk calculating unit calculates a cumulative block deterioration risk by accumulating the maximum deterioration risk of the pixels in the block for each of the regions including one or a plurality of blocks, and calculating the maximum deterioration risk in the region. 2. The video signal processing apparatus according to claim 1, wherein the cumulative block deterioration risk is accumulated to obtain a cumulative deterioration risk for each region.
The gain calculation unit calculates the deterioration risk of the pixel by using a cumulative deterioration risk of an area including a pixel for calculating the deterioration risk and a cumulative deterioration risk of an area adjacent to the area. Item 2. The video signal processing device according to Item 1.
The gain calculating unit is configured to reduce the cumulative deterioration of each of the regions at a ratio according to a distance from a boundary between a region including the pixel for calculating the deterioration risk and an adjacent region to a pixel for calculating the deterioration risk. The video signal processing apparatus according to claim 3, wherein a risk of deterioration of the pixel is calculated using a risk.
The gain calculation unit calculates a gain adjustment amount for each pixel in accordance with a risk of deterioration for each pixel, and calculates a correction gain based on the gain adjustment amount for each pixel and the luminance of the pixel. Video signal processing device.
A target gain map storage unit that stores a target gain map in which a target gain, which is an allowable luminance reduction amount of a light emitting element that emits light based on the video signal, is indicated for each pixel position;
The video signal processing apparatus according to claim 1, wherein the gain calculation unit calculates a correction gain for each pixel based on the deterioration risk for each pixel, the luminance for each pixel, and the target gain.
The target gain is set for each pixel position based on the cumulative light emission amount calculated for each pixel using the sample image according to the display time ratio for each application and the deterioration characteristics of the light emitting element that emits light based on the video signal. The video signal processing apparatus according to claim 6, further comprising a target gain map creating unit that creates a target gain map.
The target gain map creation unit
A cumulative light emission amount for each pixel is calculated in accordance with the display time ratio for each application, and based on the cumulative light emission amount that is an allowable luminance reduction amount for the light emitting element and the cumulative light emission amount calculated for each pixel. A target gain calculation processing unit for calculating a target gain for each pixel;
The video signal processing apparatus according to claim 7, further comprising a target gain integration unit that integrates the target gain calculated for each pixel for each region and calculates the target gain for each region.
The video signal processing device according to claim 7, wherein the target gain map creation unit updates the sample image or the deterioration characteristic to a sample image or deterioration characteristic acquired from the outside.
The gain calculation unit calculates a gain adjustment amount for each pixel according to the degree of deterioration risk for each pixel and the target gain, and calculates a correction gain based on the gain adjustment amount for each pixel and the luminance of the pixel. The video signal processing apparatus according to claim 6.
The video signal processing apparatus according to claim 10, wherein the gain calculation unit calculates a gain adjustment amount so that a deterioration degree of the light emitting element that lowers a luminance of a pixel based on the target gain becomes a desired deterioration degree.
The video signal processing apparatus according to claim 10, wherein the gain calculation unit calculates a gain adjustment amount based on the target gain so that a decrease in luminance becomes a desired speed in a pixel in a region where the light emitting element is likely to deteriorate.
A target gain map is created by setting the target gain for each pixel position based on the accumulated light emission amount calculated for each pixel based on the image of the application and the deterioration characteristics of the light emitting element that emits light based on the video signal. The video signal processing apparatus according to claim 6, further comprising a gain map creation unit.
The target gain map creating unit creates the target gain map for each application,
The video signal processing apparatus according to claim 13, wherein the gain calculation unit calculates the correction gain for each pixel using a target gain map of an application that matches the application of the video signal.
The target gain map creation unit
For each application, a cumulative light emission amount for each pixel is calculated based on the image of the application, and based on a cumulative light emission amount that is an allowable luminance reduction amount for the light emitting element and a cumulative light emission amount calculated for each pixel. A target gain calculation processing unit for calculating a target gain for each pixel;
The video signal processing apparatus according to claim 13, further comprising a target gain integration unit that integrates the target gain calculated for each pixel for each region and calculates a target gain for each region.
The video signal processing apparatus according to claim 6, wherein the target gain map storage unit updates the target gain map to a target gain map acquired from the outside.
A target gain map creation unit that creates the target gain map based on the accumulated light emission amount calculated for each pixel using the video signal corrected by the correction unit and the deterioration characteristics of the light emitting element that emits light based on the video signal. The video signal processing apparatus according to claim 6, further comprising:
The cumulative deterioration risk calculation unit calculates the deterioration risk for each area obtained by dividing the display screen from the light emission amount for each pixel based on the video signal, and accumulates the calculated deterioration risk for each area. A process of calculating the risk,
A gain calculation unit calculating a deterioration risk for each pixel from the cumulative deterioration risk for each region, and calculating a correction gain for each pixel based on the deterioration risk for each pixel and the luminance for each pixel;
Correcting a signal level of the video signal using the correction gain in a correction unit.