Display processing circuit and compensation method

Abstract

A display processing circuit and a compensation method are provided. The display processing circuit is used to compensate an electroluminescent display device. The display compensation circuit includes a detection circuit and a compensation circuit. The detection circuit is used to determine the degree of change of the display data within a first time length. The compensation circuit is used to increase the compensation brightness level applied to the display data when the degree of change is less than a predetermined degree.

Description

[Technical Field]

[0001] This disclosure generally relates to a circuit and a method, and more specifically, to a display processing circuit and a compensation method. [Previous Technology]

[0002] In modern technology, electroluminescence (EL) display devices play an important role in the display field. Therefore, improving various brightness degradations to enhance the user experience is crucial. [Summary of the Invention]

[0003] Therefore, this disclosure relates to a display processing circuit and compensation method capable of compensating for brightness degradation in electroluminescent display devices.

[0004] The display processing circuit disclosed herein is used to compensate an electroluminescent display device. The display compensation circuit includes a detection circuit and a compensation circuit. The detection circuit is used to determine the degree of change in display data within a first time period. The compensation circuit is used to increase the compensation brightness level applied to the display data when the degree of change is less than a predetermined level.

[0005] The compensation method disclosed herein is used to compensate an electroluminescent display device. The compensation method includes: determining the degree of change of display data within a first time length; and increasing the compensation brightness level applied to the display data when the degree of change is less than a predetermined degree.

[0006] The display processing circuit disclosed herein is used to compensate an electroluminescent display device. The display compensation circuit includes a detection circuit and a compensation circuit. The detection circuit compares an average brightness level corresponding to the display data with a brightness threshold to generate a detection signal accordingly. The compensation circuit adjusts the compensation brightness level applied to the display data when the average brightness level is greater than the brightness threshold.

[0007] To make the above content easier to understand, several embodiments will be described in detail below with reference to the accompanying drawings.

Implementation Method

[0009] Figure 1 illustrates a display processing circuit 1 according to some embodiments of the present disclosure. The display processing circuit 1 can be used in an electroluminescent display device to compensate for its display quality. Specifically, the display processing circuit 1 can be coupled to a display panel. The display processing circuit 1 can be used to receive input display data DDin and compensate the input display data DDin with a compensation brightness level when necessary.

[0010] In some embodiments, the electroluminescent display device may be a light-emitting diode (LED) based display device. The electroluminescent display device may include LEDs, organic light-emitting diodes, micro LEDs, or similar elements in its display panel for display. In certain display scenarios, when one or more degradation conditions are met, the electroluminescent display device may suffer temporary brightness degradation, but once the degradation conditions no longer exist, the electroluminescent display device can quickly recover to its desired display brightness level. Thus, the display processing circuit 1 applied to the electroluminescent display device can be used to increase the brightness level of the input display data when degradation conditions occur. Since the brightness degradation is temporary, unlike burn-in, the display processing circuit 1 can be used to cancel the compensation applied to the brightness level once the degradation conditions disappear.

[0011] The display processing circuit 1 includes a detection circuit 10 and a compensation circuit 11. The detection circuit 10 is used to receive input display data DDin and determine the degree of change of the input display data DDin within a first time period. The compensation circuit 11 is used to increase the compensation brightness level applied to the input display data DDin when the degree of change is less than a predetermined level, so as to generate output display data DDout.

[0012] The detection circuit 10 includes a preprocessing circuit 100 and a judgment circuit 101. The preprocessing circuit 100 performs preliminary processing on the received input display data DDin to generate one or more display data parameters. The judgment circuit 101 determines the degree of change based on the display data parameters and determines whether the degree of change exceeds a predetermined level, and generates a detection signal DS to indicate the degree of change.

[0013] Furthermore, the compensation circuit 11 includes an accumulator circuit 110, a counter circuit 111, and a brightness compensation circuit 112. The counter circuit 111 generates a counter signal at a first frequency or a second frequency according to the degree of change. The accumulator circuit 110 is coupled to the judgment circuit 101 and the counter circuit 111, and records the compensated brightness level according to the degree of change. The brightness compensation circuit 112 is coupled to the accumulator circuit 110, and adds the brightness level corresponding to the input display data DDin to the compensated brightness level to generate output display data DDout.

[0014] In some embodiments, the display processing circuit 1 may include, but is not limited to, a central processing unit, a microprocessor, an application-specific integrated circuit, a timing controller, a graphics processing unit, a field-programmable gate array, an advanced reduced instruction set machine, or a combination thereof. Furthermore, the programmable controller 106 may also be implemented using a hardware description language (HDL), such as High-Speed ​​Hardware Description Language (VHDL), Verilog, or a similar language. In some embodiments, the processing circuit 1 may be implemented by fully custom circuitry, or designed and implemented by synthesis using a hardware description language (HDL) such as Verilog or VHDL.

[0015] FIG2A illustrates a detection circuit 10a according to some embodiments of the present disclosure. The detection circuit 10a in FIG2A is similar to the detection circuit 10 in FIG1, and therefore the detection circuit 10a can be used in the display processing circuit 1 to replace the detection circuit 1.

[0016] In this embodiment, the detection circuit 10a is used to receive and compare the first input display data DDin1 and the second input display data DDin2 received at a first time point T1 and a second time point T2, respectively. The first time point T1 and the second time point T2 are separated by a first time length. In other words, the detection circuit 10a is used to continuously monitor the input display data, and the input display data is periodically input to the detection circuit 10a at time intervals of the first time length. The detection circuit 10a is used to determine the degree of change by comparing the first input display data DDin1 and the second input display data DDin2. More specifically, the detection circuit 10a is used to determine that the degree of change between the first input display data DDin1 and the second input display data DDin2 is less than a predetermined degree when the first input display data DDin1 and the second input display data DDin2 are the same. The detection circuit 10a is used to determine that the degree of change between the first input display data DDin1 and the second input display data DDin2 is greater than or equal to a predetermined degree when the first input display data DDin1 and the second input display data DDin2 are not the same.

[0017] Specifically, the preprocessing circuit 100a is used to extract first and second feature values ​​from the first and second input display data DDin1 and DDin2, respectively. The judgment circuit 101a is used to compare the first and second feature values ​​to determine the degree of change. In some embodiments, the preprocessing circuit 100a may be a cyclic redundancy check (CRC) circuit and may be used to perform CRC operations on the first and second input display data DDin1 and DDin2 to generate corresponding first and second CRC values ​​CRC1 and CRC2 as the first and second feature values, respectively. The CRC operation may be used to generate a unique CRC value based on the content of the input display data, such that when the content carried by the input display data changes, the generated CRC value changes accordingly. Thus, the judgment circuit 101a may be used to determine whether the first and second input display data DDin1 and DDin2 are the same by comparing the first and second CRC values ​​CRC1 and CRC2, and accordingly generate a detection signal DS indicating the degree of change between the first and second input display data DDin1 and DDin2.

[0018] FIG2B illustrates a detection circuit 10b according to some embodiments of the present disclosure. The detection circuit 10b in FIG2B is similar to the detection circuit 10 in FIG1, and therefore the detection circuit 10b can be used in the display processing circuit 1 to replace the detection circuit 1.

[0019] In this embodiment, the detection circuit 10b is used to receive and compare the first input display data DDin1 and the second input display data DDin2 separated by a first time length. The detection circuit 10b is used to determine the degree of change between the first input display data DDin1 and the second input display data DDin2 by comparing the first brightness setting value and the second brightness setting value corresponding to the first input display data DDin1 and the second input display data DDin2, respectively, so as to generate a degree of change. Specifically, the first and second brightness setting values ​​extracted by the detection circuit 10b from the first and second input display data DDin1 and DDin2 can be two display brightness values ​​(dBV). In some embodiments, the DBV parameter can correspond to the brightness setting value displayed by the electroluminescent display device, and in some applications it can also be called backlight brightness. The DBV parameter can be set to a value between 0 and 99 or 0 and 4095, and each DBV parameter can correspond to a corresponding display gamma curve.

[0020] The preprocessing circuit 100b can be used to extract first and second dbv values ​​dbv1 and dbv2 from the first and second input display data DDin1 and DDin2, respectively. The judgment circuit 101b can be used to receive and compare the first and second dbv values ​​dbv1 and dbv2 to generate a degree of change. Thus, the detection circuit 10b can be used to determine that the degree of change between the first input display data DDin1 and the second input display data DDin2 is less than a predetermined degree when the first and second dbv values ​​are the same or when the difference is within a predetermined dbv range. Furthermore, the detection circuit 10b can be used to determine that the degree of change between the first input display data DDin1 and the second input display data DDin2 is greater than or equal to a predetermined degree when the first and second dbv values ​​dbv1 and dbv2 are different or when the difference exceeds a predetermined dbv range.

[0021] In some embodiments, the determination circuit 101b may be used to further receive a dbv threshold dbvth, enabling the determination circuit 101b to compare the first and second dbv values ​​dbv1, dbv2 with the dbv threshold dbvth. The determination circuit 101b may be used to generate a detection signal DS indicating that the degree of change between the first and second input display data DDin1, DDin2 is greater than or equal to a predetermined degree only when the first and second dbv values ​​dbv1, dbv2 are greater than or equal to the dbv threshold dbvth.

[0022] FIG2C illustrates a detection circuit 10c according to some embodiments of the present disclosure. The detection circuit 10a in FIG2C is similar to the detection circuit 10 in FIG1, and therefore the detection circuit 10c can be used in the display processing circuit 1 to replace the detection circuit 1.

[0023] In some embodiments, the detection circuit 10c can be used to compare the average brightness level corresponding to the input display data DDin with the brightness threshold aplth, so as to generate a detection signal DS to the compensation circuit 11.

[0024] In some embodiments, the input display data DDin carries display information for different colors (such as red, green, blue or cyan, yellow, magenta) displayed on each pixel of the display panel. The preprocessing circuit 100c can be used to calculate the average brightness level of each color in the input display data DDin, so that the determination circuit 101c can generate a degree of change for each display color in the input display data DDin. Specifically, the preprocessing circuit 100c can be used to average the brightness levels of the first to third colors corresponding to all pixels of the input display data DDin respectively, to calculate the first to third average brightness levels aplr, aplg, and aplb. For example, the preprocessing circuit 100c can be used to average the brightness levels of the red, green, and blue colors of all pixels according to the input display data DDin, to generate the first to third average brightness levels aplr, aplg, and aplb respectively. The determination circuit 101c can be used to compare the first to third average brightness levels aplr, aplg, and aplb with the brightness threshold aplth to generate the first to third detection signals DSR / DSg / DSb.

[0025] In some embodiments, the luminance threshold aplth may include multiple thresholds. For example, the luminance threshold aplth may include luminance thresholds aplthhr, aplthg, and aplthb corresponding to red, green, and blue colors, respectively. The determination circuit 101c may generate each of the detection signals DSR, DSg, and DSb based on the comparison result for each color.

[0026] In some embodiments, the detection circuit 10 applied in the display processing circuit 1 can be adaptively designed to implement any one or more functions of the detection circuits 10a-10c in FIG. 2A-2C to generate a corresponding detection signal DS. For example, the detection circuit 10 can be used to compare the first and second CRC values ​​CRC1, CRC2 of the first and second input display data DDin1, DDin2, and the first and second dbv parameters dbv1, dbv2 to generate the degree of change between the first and second input display data DDin1, DDin2. In some embodiments, when the comparison results between the first and second CRC values ​​CRC1, CRC2 and the comparison results between the first and second dbv parameters dbv1, dbv2 both show that the degree of change between the first and second input display data DDin1, DDin2 exceeds a predetermined degree, the determination circuit 101 can set the detection signal DS to a value of 0. Otherwise, when either comparison result shows that the degree of change between the first and second input display data DDin1, DDin2 is within a predetermined degree, the determination circuit 101 can set the detection signal to a value of 1 accordingly.

[0027] FIG2D illustrates a detection circuit 10d according to some embodiments of the present disclosure. The detection circuit 10d in FIG2D may be a combination of the detection circuits 10a-10c in FIG2A-2C.

[0028] In this embodiment, the detection circuit 10d can be used to sense whether the first and second input display data DDin1 and DDin2 are the same, or whether the dbv parameters dbv1 and dbv2 corresponding to the first and second input display data DDin1 and DDin2 are the same, or whether the average brightness level corresponding to the input display data DDin2 is greater than the brightness threshold aplth. Specifically, the detection circuit 10d can be used to set the detection signals DSR, DSg, and DSb together to the value 1 when the degradation condition is met, and to set the detection signals DSR, DSg, and DSb together to the value 0 when no degradation condition is detected. In addition, the detection circuit 10d can be used to set the detection signals DSR, DSg, and DSb respectively corresponding to the average brightness level of each color of the second input display data DDin2.

[0029] In this way, the detection circuit 10d can be used to adaptively provide detection signals DSR, DSg, DSb based on whether the degradation conditions are met or based on the average brightness level corresponding to the input display data DDin1 / DDin2.

[0030] FIG3A illustrates a compensation circuit 11a according to some embodiments of the present disclosure. The compensation circuit 11a in FIG3A is similar to the compensation circuit 11 in FIG1, and therefore the compensation circuit 11a can be used in the display processing circuit 1 to replace the compensation circuit 11.

[0031] In some embodiments, the compensation circuit 11a is used to increase the compensation brightness level Ofs applied to the input display data DDin when the degree of change is less than a predetermined degree, and to decrease the compensation brightness level Ofs applied to the input display data DDin when the degree of change is greater than or equal to the predetermined degree. More specifically, since the brightness degradation is temporary, the compensation circuit 11a can use an assessment of the degree of change in the input display data DDin to reduce the compensation brightness level Ofs when the degradation condition is not met.

[0032] In some embodiments, the compensation circuit 11a includes an accumulation circuit 110a, a counter circuit 111a and a brightness compensation circuit 112a.

[0033] The counter circuit 111a is coupled to the detection circuit 10 and the accumulator circuit 110a. The counter circuit 111a provides a counter signal CS to the accumulator circuit 110a according to the degree of change. The accumulator circuit 110a adjusts the compensation brightness level Ofs according to the frequency of the counter signal.

[0034] The accumulator circuit 110a is coupled to the detection circuit 10 and used to adjust the compensation brightness level Ofs. Specifically, the accumulator circuit 110a increases the compensation brightness level Ofs when the change is less than a predetermined level, and decreases the compensation brightness level Ofs when the change is greater than or equal to the predetermined level. The brightness compensation circuit 112a is coupled to the accumulator circuit 110a and used to add the brightness level corresponding to the input display data DDin to the compensation brightness level Ofs to generate the compensated output display data DDout. Specifically, the accumulator circuit 110a updates the compensation brightness level Ofs according to the detection signal DS and the counter signal CS. The brightness compensation circuit 112a extracts the brightness level from the input display data DDin, adds the extracted brightness level to the compensation brightness level Ofs, and generates the output display data DDout.

[0035] More specifically, the accumulator circuit 110a can be used to count up or down according to the degree of change to update the compensation brightness level Ofs. In some embodiments, when the value of the detection signal DS is 1, meaning that the degree of change is less than a predetermined degree, the accumulator circuit 110a can increase the compensation brightness level Ofs. Conversely, when the value of the detection signal DS is 0, meaning that the degree of change is greater than or equal to the predetermined degree, the accumulator circuit 110a can decrease the compensation brightness level Ofs.

[0036] In addition to the detection signal DS used to determine whether to increase or decrease the compensation brightness level Ofs, the accumulator circuit 110a can further be used to update the compensation brightness level Ofs according to the frequency of the counter signal CS. Specifically, each time the accumulator circuit 110a receives the rising edge of the counter signal CS, the accumulator circuit 110a can be used to increase or decrease the compensation brightness level Ofs according to the detection signal DS. In this way, the compensation brightness level Ofs can be adjusted at different frequencies. In some embodiments, the first frequency used to increase the compensation brightness level Ofs may be lower than the second frequency used to decrease the compensation brightness level Ofs.

[0037] To provide counter signals CS at different frequencies, counter circuit 111a receives an up-counting clock signal oscillating at a first frequency fu and a down-counting clock signal oscillating at a second frequency fd. When the value of the detection signal DS is 1, indicating that the degree of change is less than a predetermined degree, counter circuit 111a can provide an up-counting clock signal Clku oscillating at the first frequency fu as the counter signal CS. Conversely, when the value of the detection signal DS is 0, indicating that the degree of change is greater than or equal to a predetermined degree, counter circuit 111a can provide a down-counting clock signal Clkd oscillating at the second frequency fd as the counter signal CS.

[0038] In some embodiments, the accumulator circuit 111a can be used to update the compensated brightness level Ofs with an equal or different brightness offset. For example, the accumulator circuit 111a can be used to adjust the compensated brightness level Ofs by adding or subtracting the same brightness offset each time the counter signal CS is triggered. In another example, the accumulator circuit 111a can be used to receive the brightness ratio Ofsr and adjust the compensated brightness level Ofs by multiplying or dividing by the brightness ratio Ofsr. Specifically, the brightness ratio Ofsr may be greater than 1, so the accumulator circuit 110a can be used to increase the compensated brightness level Ofs by multiplying the compensated brightness level Ofs by the brightness ratio Ofsr, or the accumulator circuit 110a can be used to decrease the compensated brightness level Ofs by dividing the compensated brightness level Ofs by the brightness ratio Ofsr.

[0039] In some embodiments, the accumulator circuit 111a can be used to adjust the compensation brightness level Ofs within a specific range. For example, the accumulator circuit 111a can be used to receive the maximum compensation brightness level Ofsmax, and the accumulator circuit 111a can be used to increase the compensation brightness level Ofs until the compensation brightness level Ofs reaches the maximum compensation brightness level Ofsmax.

[0040] FIG3B illustrates a compensation circuit 11b according to some embodiments of the present disclosure. The compensation circuit 11b in FIG3B is similar to the compensation circuit 11a in FIG3A, therefore, detailed operation is provided in the above paragraphs and is omitted here.

[0041] In this embodiment, the compensation circuit 11b is used to receive first to third detection signals DSR, DSg, and DSb, respectively, corresponding to different colors of the input display data DDin. The compensation circuit 11b can be used to generate first to third compensation brightness levels Ofsr, Ofsg, and Ofsb and update them at different frequencies.

[0042] Specifically, the counter circuit 111b can be coupled to the detection circuit 10. The counter circuit 111b can be used to provide first to third counter signals CSR, CSg, CSb according to the first to third detection signals DSR, DSg, DSb respectively. The accumulator circuit 110b can be coupled to the detection circuit 10 and the counter circuit 111b. The accumulator circuit 110b can be used to adjust the first to third compensation brightness levels Ofsr, Ofsg, Ofsb according to the first to third detection signals DSR, DSg, DSb respectively. The brightness compensation circuit 112b can be coupled to the accumulator circuit 110b and is used to generate compensated output display data DDout by adding the brightness level corresponding to the first color of the input display data DDin to the first compensation brightness level Ofsr, adding the brightness level corresponding to the second color of the input display data DDin to the second compensation brightness level Ofsg, and adding the brightness level corresponding to the third color of the input display data DDin to the third compensation brightness level Ofsb.

[0043] In some embodiments, the compensation circuit 11b can independently adjust each of the first to third compensation brightness levels Ofsr, Ofsg, and Ofsb, meaning that the first to third compensation brightness levels can be increased or decreased at different frequencies. In this way, the counter circuit 111b is used to receive the first to third up-counting frequencies and the first to third down-counting frequencies. The first up-counting and down-counting frequencies are used to adjust the first compensation brightness level Ofsr, the second up-counting and down-counting frequencies are used to adjust the second compensation brightness level Ofsg, and the third up-counting and down-counting frequencies are used to adjust the third compensation brightness level Ofsb. Specifically, the counter circuit 111b can be used to provide a first counter signal CSg oscillating at the first up-counting frequency fur or the first down-counting frequency fdr according to the first detection signal DSR. The counter circuit 111b can be used to provide a second counter signal CSg oscillating at the second up-counting frequency fug or the second down-counting frequency fdg according to the second detection signal DSR. The counter circuit 111b can be used to provide a third counter signal CSb that oscillates at a third upper counting frequency fub or a third lower counting frequency fdb, based on the third detection signal DSb. The first upper counting frequency fur, the second upper counting frequency fug, and the third upper counting frequency fvb are lower than the first lower counting frequency fdr, the second lower counting frequency fdg, and the third lower counting frequency fdb, respectively.

[0044] In some embodiments, the accumulator circuit 110b can be used to increase the first compensation brightness level Ofsr at a first upper counting frequency fur or decrease the first compensation brightness level Ofsr at a first lower counting frequency fdr. The accumulator circuit 110b can be used to increase the second compensation brightness level Ofsg at a second upper counting frequency fug or decrease the second compensation brightness level Ofsg at a second lower counting frequency fdg. The accumulator circuit 110b can be used to increase the third compensation brightness level Ofsb at a third upper counting frequency fub or decrease the third compensation brightness level Ofsb at a third lower counting frequency fdb.

[0045] FIG4 illustrates a display processing circuit 4 according to some embodiments of the present disclosure. The display processing circuit 4 in FIG4 is similar to the display processing circuit 1 in FIG1, and therefore the same or similar circuit blocks are labeled with the same reference numerals.

[0046] In this embodiment, the operating frequencies of certain circuit blocks are described. Specifically, the preprocessing circuit 100 and the judgment circuit 101 operate according to a clock signal with a detection frequency f1. At the same time, the counter circuit 111 in the compensation circuit 11 provides an oscillating counter signal to the accumulator circuit 110 at a counting frequency above fc or a counting frequency below fd.

[0047] Specifically, the preprocessing circuit 100 and the judgment circuit 101 can operate at the detection frequency f1, allowing the detection circuit 10 to generate a detection signal DS at the detection frequency f1. Furthermore, the compensation circuit 11, which receives the detection signal, can adjust the compensation brightness level Ofs at either the upper counting frequency fu or the lower counting frequency fd. In this way, the display processing circuit 4 can better compensate for or cancel display brightness to improve image display quality. For example, since brightness degradation may occur after prolonged application of degradation conditions, but will quickly recover to the desired brightness level once the degradation conditions disappear, the upper counting frequency fu can be selected from a frequency lower than the lower counting frequency fd, meaning that the compensation brightness level Ofs can increase at a relatively low rate but release at a faster rate.

[0048] Figure 5A illustrates multiple images IM11-IM18, showing how the display images of an electroluminescent display device change according to some embodiments of the present disclosure.

[0049] Specifically, the electroluminescent display device displaying the image in FIG5A may include the display processing circuit 1 in FIG1, such that a compensation brightness level can be applied to the display image when the degradation condition is met. In this embodiment, the degradation condition includes three sub-conditions: the characteristic values ​​between two display input data are the same or differ within a predetermined range, the brightness set values ​​between two display input data are the same or differ within a predetermined range, and the average brightness level of the display input data is greater than or equal to a brightness threshold. Thus, as long as one of the three sub-conditions of the above degradation condition is met, the detection circuit 10 can be used to set the detection signal to a value of 1, instructing the compensation circuit 11 to start counting and increase the compensation brightness level. On the other hand, only when none of the three sub-conditions of the degradation condition are met, the detection circuit 10 can be used to set the detection signal to a value of 0, instructing the compensation circuit 11 to start counting down to decrease the compensation brightness level.

[0050] As shown in Figure 5A, when the electroluminescent display device displays image IM11, the dbv parameter of the electroluminescent display device is set to 4095, corresponding to the maximum display brightness. After the dbv parameter is maintained at 4095 for 180 seconds, which is one cycle of the counting frequency fu, the display processing circuit 1 can be used to increase the compensation brightness level from 0 to the first compensation brightness level ofs1. For example, the brightness level W250 corresponding to the input display data DDin and displayed as image IM1 can be compensated to the brightness level W250+ofs1 corresponding to the output display data DDout and displayed as image IM2.

[0051] As the dbv parameter remains at 4095, the display processing circuit 1 can continuously increase the compensation brightness level every 180 seconds, so that the compensation brightness level of image IM13 becomes W250+ofs2, and continues to become W250+ofs3 in image IM14.

[0052] One second later, the dbv parameter in image IM15 decreases to 2048, making the dbv parameter less than the dbv threshold and the degradation condition no longer met. Thus, after one frame corresponding to the lower counting frequency, the display processing circuit 1 can reduce the compensation brightness level, making the compensation brightness level W0+ofs2 in image IM16. Subsequently, the compensation brightness level continues to decrease to W0+ofs1 and W0 in images IM17 and IM18, respectively. Specifically, this series of images demonstrates how the display processing circuit 1 configures the brightness level of the compensation input display data DDin based on the detection frequency f1, the upper counting frequency fu, and the lower counting frequency fd.

[0053] In some embodiments, when the brightness level corresponding to the input display data DDin is W0, the display processing circuit 1 can cancel the compensation brightness level to 0. In this embodiment, the brightness level W0 can be the lowest brightness level for displaying black. Since there is no need to increase the brightness of black, the brightness compensation circuit 112 of the display processing circuit 1 can cancel the compensation brightness level and directly output the brightness level W0 as the output display data DDout.

[0054] Figure 5B illustrates multiple images IM21-IM28, showing how the display images of an electroluminescent display device change according to some embodiments of the present disclosure.

[0055] Specifically, the electroluminescent display device displaying the image in FIG. 5B may include the display processing circuit 1 in FIG. 1, such that a compensation brightness level can be applied to the display image when the degradation condition is met. In this embodiment, the degradation condition includes three sub-conditions: the characteristic values ​​between two display input data are the same or differ within a predetermined range, the brightness set values ​​between two display input data are the same or differ within a predetermined range, and the average brightness level of the display input data is greater than or equal to a brightness threshold. Thus, as long as one of the three sub-conditions of the above degradation condition is met, the detection circuit 10 can be used to set the detection signal to a value of 1, instructing the compensation circuit 11 to start counting and increase the compensation brightness level. On the other hand, only when all three sub-conditions of the degradation condition are not met, the detection circuit 10 can be used to set the detection signal to a value of 0, instructing the compensation circuit 11 to start counting down to decrease the compensation brightness level.

[0056] In this embodiment, the display image of the electroluminescent display device can be divided into three regions A1-A3. For example, the electroluminescent display device can be used to display a video, region A1 is used to display a video illustration, region A2 is used to display video content, and region A3 is used to display video information, such as video title, subtitles, etc. In this way, the content in region A2 may be dynamic and constantly changing, while the content in regions A1 and A3 may be static and updated at a relatively low frequency. The display processing circuit 1 can be used to individually compensate for the brightness level of each display region.

[0057] As shown in images IM21-IM24, areas A1 and A3 are statically displayed at brightness levels WA and WC1, respectively. Therefore, display processing circuit 1 can increase the compensation brightness level once every 180 seconds. Meanwhile, area A2 displays a constantly changing image, so no compensation is performed on area A2.

[0058] One second after displaying image IM24, in the displayed image IM25, area A3 changes from display brightness level WC2 to another brightness level WC3, so that the content in area A3 is no longer static, and display processing circuit 1 starts to release or reduce the compensation brightness level applied to area A3.

[0059] After displaying one frame of image IM25, the display processing circuit 1 reduces the compensation brightness level applied to area A3 in image IM26 from ofs3 to ofs2. Furthermore, since the brightness level of area A3 displayed in images IM27 and IM28 continues to change, the compensation brightness level applied to area A3 continues to decrease in images IM27 and IM28.

[0060] In images IM26-IM28, although the compensation brightness level applied to region A3 decreases, the compensation brightness level applied to region A1 remains unchanged at ofs3. Specifically, since the upward counting frequency fu is lower than the downward counting frequency fd, the compensation brightness level applied to region A1 increases once every 180 seconds and remains at ofs3 in images IM24-IM28.

[0061] FIG6 illustrates a flowchart of a compensation method according to some embodiments of the present disclosure. This compensation method can be applied to an image processing apparatus in an electroluminescent display device to compensate for the brightness level displayed by the electroluminescent display device. This compensation method can be applied to the image processing apparatus 1 in FIG1.

[0062] The compensation method includes steps S60 and S61. In step S60, the detection circuit 10 can be used to determine the degree of change of the displayed data within a first time length. In step S61, when the degree of change is less than a predetermined degree, the compensation circuit 11 can be used to increase the compensation brightness level applied to the displayed data. For more details about the display processing circuit 10, please refer to the above paragraph, which will not be repeated here.

[0063] Figures 7A-7C illustrate comparative brightness of electroluminescent display devices according to some embodiments of the present disclosure. Specifically, Figures 7A-7C illustrate the brightness measured when the electroluminescent display device displays an initial brightness of 247 nits, 454 nits, and 901 nits, respectively. Each of Figures 7A-7C illustrates two measurement curves, one curve showing the brightness displayed by the electroluminescent device having the display processing circuit 1 in Figure 1, and the other curve showing the brightness without brightness level compensation.

[0064] Figure 7A shows two curves, L70 and L71. Curve L70 corresponds to the measured brightness displayed by the electroluminescent display device with the built-in display processing circuit 1 (i.e., after brightness level compensation), while curve L71 corresponds to the measured brightness displayed by the electroluminescent display device without brightness level compensation. It can be seen from curves L70 and L71 that the two electroluminescent display devices are controlled to display the same brightness and maintain that brightness for a certain period of time. However, as the processing time increases, both electroluminescent display devices deteriorate. Compared to curve L71, the brightness degradation of curve L70 is relatively small, indicating that the display processing circuit 1 can effectively compensate for the brightness degradation.

[0065] Similarly, in Figures 7B and 7C, curves L72 and L74 show the brightness curves displayed by an electroluminescent display device with a built-in display processing circuit 1, while curves L73 and L75 show the brightness curves displayed by an electroluminescent display device without the display processing circuit 1. Curves L72 and L74 also show that the electroluminescent display device exhibits a smaller degree of brightness degradation when displaying higher brightness.

[0066] In some embodiments, the display processing circuit 1 can effectively control the degree of brightness degradation within a small range, such as between 1 au (any unit) and 0.99 au, effectively improving the display quality of the electroluminescent display device and providing a better user experience.

[0067] In summary, the image processing apparatus and compensation method can be used in various situations to compensate for temporary brightness degradation, maintaining the brightness level of the electroluminescent display device within a predetermined brightness range. Furthermore, for user comfort, the display processing circuitry increases the compensation brightness level at a frequency lower than that of reducing the compensation brightness level. In this way, the image processing apparatus and compensation method can effectively maintain approximately the same brightness of the electroluminescent display device, preventing brightness degradation from being observed, thereby improving display quality and user satisfaction.

[0068] To those skilled in the art, various modifications and variations can be made to the disclosed embodiments without departing from the scope or spirit of this disclosure. In view of the foregoing, this disclosure is intended to cover modifications and variations falling within the scope of the following claims and their equivalents. [Simplified Explanation of the Diagram]

[0008] The accompanying drawings are included to provide a further understanding of the present disclosure and form part of this specification. These drawings illustrate exemplary embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure. FIG1 illustrates a display processing circuit according to some embodiments of the present disclosure. FIG2A illustrates a detection circuit according to some embodiments of the present disclosure. FIG2B illustrates a detection circuit according to some embodiments of the present disclosure. FIG2C illustrates a detection circuit according to some embodiments of the present disclosure. FIG2D illustrates a detection circuit according to some embodiments of the present disclosure. FIG3A illustrates a compensation circuit according to some embodiments of the present disclosure. FIG3B illustrates a compensation circuit according to some embodiments of the present disclosure. FIG4 illustrates a display processing circuit according to some embodiments of the present disclosure. FIG5A illustrates multiple images showing how the display image of an electroluminescent display device changes, according to some embodiments of the present disclosure. FIG5B illustrates multiple images showing how the display image of an electroluminescent display device changes, according to some embodiments of the present disclosure. FIG6 illustrates a flowchart of a compensation method according to some embodiments of the present disclosure. FIG7A-7C illustrate a brightness comparison of an electroluminescent display device according to some embodiments of the present disclosure.

Claims

1. A display processing circuit for compensating an electroluminescence (EL) display device, the display processing circuit comprising: a detection circuit for determining a degree of change of display data within a first time period; and a compensation circuit for increasing a compensation brightness level applied to the display data when the degree of change is less than a predetermined degree.

2. The display processing circuit as claimed in claim 1, wherein the compensation circuit is used to reduce the compensation brightness level applied to the display data when the degree of change is greater than or equal to the predetermined degree.

3. The display processing circuit as claimed in claim 1, wherein the detection circuit is configured to receive and compare a first display data and a second display data received at a first time point and a second time point, the first time point and the second time point being separated by the first time length, wherein the detection circuit is configured to determine that the degree of change is less than the predetermined degree when the first display data and the second display data are the same, and wherein the detection circuit is configured to determine that the degree of change is greater than or equal to the predetermined degree when the first display data and the second display data are not the same.

4. The display processing circuit as claimed in claim 3, wherein the detection circuit comprises: a preprocessing circuit for extracting a first feature value and a second feature value from the first display data and the second display data, respectively; and a judgment circuit for comparing the first feature value and the second feature value to generate the degree of change.

5. The display processing circuit as claimed in claim 4, wherein the preprocessing circuit is configured to perform a cyclic redundancy check (CRC) on the first display data and the second display data to generate the first feature value and the second feature value.

6. The display processing circuit as claimed in claim 1, wherein the detection circuit is configured to receive and compare a first display data and a second display data separated by the first time length, and the detection circuit is configured to determine the degree of change between the first display data and the second display data by comparing a first brightness setting value and a second brightness setting value corresponding to the first display data and the second display data respectively, so as to generate the degree of change.

7. The display processing circuit as claimed in claim 6, wherein the first brightness setting value and the second brightness setting value are a first display brightness value and a second display brightness value, the detection circuit comprising: a judgment circuit for receiving and comparing the first display brightness value and the second display brightness value to generate the degree of change.

8. The display processing circuit of claim 1, wherein the compensation circuit comprises: an accumulation circuit coupled to the detection circuit and used to increase the compensated brightness level when the degree of change is less than the predetermined degree; and a brightness compensation circuit coupled to the accumulation circuit and used to add the brightness level corresponding to the display data to the compensated brightness level to generate compensated display data.

9. The display processing circuit of claim 8, wherein the compensation circuit comprises: a counter circuit coupled to the detection circuit and the accumulation circuit, the counter circuit being configured to provide a counter signal to the accumulation circuit according to the degree of change, wherein the accumulation circuit being configured to adjust the compensated brightness level according to the frequency of the counter signal.

10. The display processing circuit of claim 9, wherein the counter circuit is configured to provide a counter signal oscillating at a first frequency when the degree of change is less than the predetermined degree, and to provide a counter signal oscillating at a second frequency faster than the first frequency when the degree of change is greater than or equal to the predetermined degree.

11. The display processing circuit of claim 8, wherein the accumulator circuit is configured to increase the compensated brightness level by multiplying the compensated brightness level by a brightness ratio, or the accumulator circuit is configured to increase the compensated brightness level by adding a brightness offset to the compensated brightness level.

12. The display processing circuit as claimed in claim 2, wherein the compensation circuit is used to increase the compensated brightness level until a maximum compensated brightness level is reached.

13. The display processing circuit of claim 1, wherein the detection circuit is configured to compare an average brightness level corresponding to the display data with a brightness threshold to generate a detection signal to the compensation circuit accordingly.

14. The display processing circuit of claim 13, wherein the detection circuit comprises: a preprocessing circuit for calculating a first average brightness level, a second average brightness level, and a third average brightness level by averaging the brightness levels of a first color to a third color corresponding to all pixels in the display data; and a judging circuit for comparing the first average brightness level to the third average brightness level with a first brightness threshold to a third brightness threshold to generate a first detection signal to a third detection signal.

15. The display processing circuit of claim 14, wherein the compensation circuit comprises: a counter circuit coupled to the detection circuit, the counter circuit being configured to provide a first counter signal to a third counter signal according to the first detection signal to the third detection signal, respectively; an accumulation circuit coupled to the detection circuit and the counter circuit, the accumulation circuit being configured to adjust a first compensation brightness level, a second compensation brightness level, and a third compensation brightness level according to the first detection signal to the third detection signal and the first counter signal to the third counter signal, respectively; and a brightness compensation circuit coupled to the accumulation circuit, and configured to generate compensated display data by adding a first brightness level corresponding to a first color of the display data to the first compensation brightness level, adding a second brightness level corresponding to a second color of the display data to the second compensation brightness level, and adding a third brightness level corresponding to a third color of the display data to the third compensation brightness level.

16. The display processing circuit of claim 15, wherein the counter circuit is configured to provide a first counter signal oscillating at a first up-counting frequency or a first down-counting frequency according to the first detection signal, the counter circuit is configured to provide a second counter signal oscillating at a second up-counting frequency or a second down-counting frequency according to the second detection signal, and the counter circuit is configured to provide a third counter signal oscillating at a third up-counting frequency or a third down-counting frequency according to the third detection signal, wherein the first up-counting frequency, the second up-counting frequency, and the third up-counting frequency are respectively lower than the first down-counting frequency, the second down-counting frequency, and the third down-counting frequency.

17. The display processing circuit of claim 16, wherein the accumulator circuit is configured to increase the first compensated brightness level at the first up-counting frequency or decrease the first compensated brightness level at the first down-counting frequency, the accumulator circuit is configured to increase the second compensated brightness level at the second up-counting frequency or decrease the second compensated brightness level at the second down-counting frequency, and the accumulator circuit is configured to increase the third compensated brightness level at the third up-counting frequency or decrease the third compensated brightness level at the third down-counting frequency.

18. The display processing circuit of claim 1, wherein the detection circuit is further configured to generate a first degree of variation and a second degree of variation corresponding to a first display area and a second display area on an electroluminescent display device, respectively, based on the display data, and the compensation circuit is further configured to adjust a first area compensation brightness level and a second area compensation brightness level according to the first degree of variation and the second degree of variation, respectively.

19. A compensation method for compensating an electroluminescence (EL) display device, the compensation method comprising: determining the degree of change of a display data within a first time length; and when the degree of change is less than a predetermined degree, increasing a compensation brightness level applied to the display data.

20. The compensation method as described in claim 19, comprising: reducing the compensation brightness level applied to the display data when the degree of change is greater than or equal to the predetermined degree.

21. The compensation method as described in claim 19, comprising: receiving and comparing a first display data and a second display data at a first time point and a second time point, the first time point and the second time point being separated by the first time length; determining that the degree of change is less than a predetermined degree when the first display data and the second display data are the same; and determining that the degree of change is greater than or equal to the predetermined degree when the first display data and the second display data are different.

22. The compensation method as claimed in claim 21, comprising: extracting a first feature value and a second feature value from the first display data and the second display data, respectively; and comparing the first feature value and the second feature value to generate the degree of change.

23. The compensation method as described in claim 22, comprising: performing a cyclic redundancy check (CRC) on the first display data and the second display data to generate the first feature value and the second feature value.

24. The compensation method as claimed in claim 20, comprising: receiving and comparing a first display data and a second display data separated by the first time length; determining a degree of change between the first display data and the second display data by comparing a first brightness setting value and a second brightness setting value corresponding to the first display data and the second display data, respectively, to generate the degree of change.

25. The compensation method as described in claim 24, wherein the first brightness setting value and the second brightness setting value are a first display brightness value and a second display brightness value, the compensation method comprising: receiving and comparing the first display brightness value and the second display brightness value to generate the degree of change.

26. The compensation method as described in claim 19, comprising: adding the brightness level corresponding to the display data to the compensated brightness level to generate a compensated display data.

27. The compensation method as described in claim 26 further comprises: providing a counter signal according to the degree of change, wherein the compensated brightness level is adjusted according to the frequency of the counter signal.

28. The compensation method as claimed in claim 27, wherein when the degree of change is less than the predetermined degree, a counter signal oscillating at a first frequency is provided, and when the degree of change is greater than or equal to the predetermined degree, a counter signal oscillating at a second frequency faster than the first frequency is provided.

29. The compensation method as described in claim 28, wherein the compensated brightness level is increased by multiplying the compensated brightness level by a brightness ratio, or the compensated brightness level is increased by adding a brightness offset to the compensated brightness level.

30. The compensation method as described in claim 20, wherein the compensation brightness level increases until a maximum compensation brightness level is reached.

31. The compensation method as described in claim 19, comprising: comparing an average brightness level corresponding to the display data with a brightness threshold to generate a detection signal accordingly.

32. The compensation method as claimed in claim 31, comprising: averaging the brightness levels of a first color to a third color corresponding to all pixels of the display data to calculate a first average brightness level, a second average brightness level, and a third average brightness level; and comparing the first average brightness level to the third average brightness level with a first brightness threshold to a third brightness threshold to generate a first detection signal to a third detection signal.

33. The compensation method as described in claim 32, comprising: providing a first counter signal to a third counter signal according to the first detection signal to the third detection signal respectively; adjusting a first compensation brightness level, a second compensation brightness level, and a third compensation brightness level according to the first detection signal to the third detection signal and the first counter signal to the third counter signal respectively; and generating compensated display data by adding a first brightness level corresponding to a first color of the display data to the first compensation brightness level, adding a second brightness level corresponding to a second color of the display data to the second compensation brightness level, and adding a third brightness level corresponding to a third color of the display data to the third compensation brightness level.

34. The compensation method as claimed in claim 33, comprising: providing a first counter signal oscillating at a first up-counting frequency or a first down-counting frequency based on the first detection signal; providing a second counter signal oscillating at a second up-counting frequency or a second down-counting frequency based on the second detection signal; and providing a third counter signal oscillating at a third up-counting frequency or a third down-counting frequency based on the third detection signal, wherein, The first up-counting frequency, the second up-counting frequency, and the third up-counting frequency are respectively lower than the first down-counting frequency, the second down-counting frequency, and the third down-counting frequency.

35. The compensation method as claimed in claim 34, comprising: increasing the first compensation brightness level at the first up-counting frequency or decreasing the first compensation brightness level at the first down-counting frequency; increasing the second compensation brightness level at the second up-counting frequency or decreasing the second compensation brightness level at the second down-counting frequency; and increasing the third compensation brightness level at the third up-counting frequency or decreasing the third compensation brightness level at the third down-counting frequency.

36. The compensation method as claimed in claim 19, comprising: generating a first degree of variation and a second degree of variation corresponding to a first display area and a second display area on the electroluminescent display device, respectively, based on the display data; and adjusting a first area compensation brightness level and a second area compensation brightness level, respectively, based on the first degree of variation and the second degree of variation.

37. A display processing circuit for compensating an electroluminescence (EL) display device, the display processing circuit comprising: a detection circuit for comparing an average brightness level corresponding to a display data with a brightness threshold to generate a detection signal thereon; and a compensation circuit for adjusting a compensation brightness level applied to the display data when the average brightness level is greater than the brightness threshold.

38. The display processing circuit of claim 37, wherein the detection circuit comprises: a preprocessing circuit for calculating a first average brightness level, a second average brightness level, and a third average brightness level by averaging the brightness levels of a first color to a third color corresponding to all pixels of the display data; and a judging circuit for comparing the first average brightness level to the third average brightness level with a first brightness threshold to a third brightness threshold to generate a first detection signal to a third detection signal.

39. The display processing circuit of claim 38, wherein the compensation circuit comprises: a counter circuit coupled to the detection circuit, the counter circuit being configured to provide a first counter signal to a third counter signal respectively based on the first detection signal to the third detection signal; an accumulation circuit coupled to the detection circuit and the counter circuit, the accumulation circuit being configured to adjust a first compensation brightness level, a second compensation brightness level, and a third compensation brightness level respectively based on the first detection signal to the third detection signal and the first counter signal to the third counter signal; and a brightness compensation circuit coupled to the accumulation circuit, and configured to generate compensated display data by adding a first brightness level corresponding to a first color of the display data to the first compensation brightness level, adding a second brightness level corresponding to a second color of the display data to the second compensation brightness level, and adding a third brightness level corresponding to a third color of the display data to the third compensation brightness level.

40. The display processing circuit of claim 39, wherein the counter circuit is configured to provide a first counter signal oscillating at a first up-counting frequency or a first down-counting frequency, the counter circuit is configured to provide a second counter signal oscillating at a second up-counting frequency or a second down-counting frequency, and the counter circuit is configured to provide a third counter signal oscillating at a third up-counting frequency or a third down-counting frequency, wherein the first up-counting frequency, the second up-counting frequency, and the third up-counting frequency are respectively lower than the first down-counting frequency, the second down-counting frequency, and the third down-counting frequency.

41. The display processing circuit of claim 40, wherein the accumulator circuit is configured to increase the first compensated brightness level at the first up-counting frequency or decrease the first compensated brightness level at the first down-counting frequency, the accumulator circuit is configured to increase the second compensated brightness level at the second up-counting frequency or decrease the second compensated brightness level at the second down-counting frequency, and the accumulator circuit is configured to increase the third compensated brightness level at the third up-counting frequency or decrease the third compensated brightness level at the third down-counting frequency.

Images