Driving method for display device and display device

Abstract

To provide a driving method for a display device and the like capable of extending the service life of a plurality of pixels while suppressing unnecessary reduction in the luminance of the plurality of pixels.SOLUTION: A driving method for a display device comprises: a conversion step S10 for converting a plurality of first luminance signals corresponding to a plurality of pixels P into a plurality of second luminance signals; and a driving step S30 for driving a display unit 10 on the basis of the plurality of second luminance signals. The conversion step S10 includes: a weight calculation step S11 for calculating weight with respect to the lighting time of the display unit 10 determined on the basis of the plurality of first luminance signals or the plurality of second luminance signals; an accumulated value calculation step S12 for calculating an accumulated value by accumulating the values related to the weight; a reduction ratio calculation step S13 for calculating a reduction ratio for reducing each of the plurality of first luminance signals on the basis of the accumulated value; and a second luminance signal calculation step S14 for calculating the plurality of second luminance signals on the basis of the reduction ratio and the plurality of first luminance signals.SELECTED DRAWING: Figure 8

Description

[Technical field]

[0001] The present disclosure relates to a display device driving method and a display device. [Background technology]

[0002] Conventionally, display devices have been developed in which each pixel includes a self-luminous element, such as an organic EL (Electro-Luminescence) display device. In such display devices, it is known that the self-luminous elements, such as the organic EL elements, deteriorate.

[0003] In the invention described in Patent Document 1, peak luminance control is performed according to the lighting time based on a preset luminance decay curve. Here, the luminance decay curve refers to a graph showing the change in the decay rate (luminance maintenance rate) of the organic EL element versus the lighting time. In the invention described in Patent Document 1, an optimal luminance decay curve is used according to the load expected on the organic EL element, thereby preventing deterioration of the image quality of the display device and extending the life of the organic EL element.

[0004] In the invention described in Patent Document 2, the peak luminance of all pixels included in a display device is lowered to the luminance at which the most deteriorated pixel can display. This is intended to prevent only a specific pixel from becoming lower in luminance, thereby preventing the image quality of the display device from being impaired. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2015 / 174077 [Patent Document 2] U.S. Patent No. 10,867,551 Summary of the Invention [Problem to be solved by the invention]

[0006] However, in the display device described in Patent Document 1, since a preset brightness decay curve is used, if the actual brightness decay of each organic EL element is smaller than the expected brightness decay, the peak brightness is set lower than necessary, which unnecessarily reduces the appeal of the image displayed by the display device.

[0007] Furthermore, in the display device described in Patent Document 2, if there is even one pixel among multiple pixels that is severely deteriorated, the luminance of the other pixels is significantly reduced to match that pixel, thereby reducing the attractiveness of the image displayed by the display device.

[0008] The present disclosure has been made in consideration of the above-mentioned problems, and aims to provide a method for driving a display device that can extend the life of multiple pixels while preventing the luminance of multiple pixels in the display device from decreasing more than necessary. [Means for solving the problem]

[0009] In order to achieve the above-mentioned object, a driving method of a display device according to one embodiment of the present disclosure is a driving method of a display device having a display unit having a plurality of pixels, and includes a conversion step of converting a plurality of first luminance signals corresponding to the plurality of pixels into a plurality of second luminance signals, and a driving step of driving the display unit based on the plurality of second luminance signals, wherein the conversion step includes a weight calculation step of calculating a weight for a lighting time of the display unit, which is determined based on the plurality of first luminance signals or the plurality of second luminance signals, an accumulation value calculation step of calculating an accumulation value obtained by accumulating values ​​related to the weight, a reduction rate calculation step of calculating a reduction rate for reducing each of the plurality of first luminance signals based on the accumulation value, and a second luminance signal calculation step of calculating the plurality of second luminance signals based on the reduction rate and the plurality of first luminance signals.

[0010] In addition, in order to achieve the above-mentioned object, a display device according to one embodiment of the present disclosure is a display device including a display unit having a plurality of pixels, and a conversion unit that converts a plurality of first luminance signals corresponding to the plurality of pixels into a plurality of second luminance signals, the conversion unit including a weight calculation unit that calculates a weight for a lighting time of the display unit, which is determined based on the plurality of first luminance signals or the plurality of second luminance signals, a cumulative value calculation unit that calculates a cumulative value by accumulating values ​​related to the weight, a reduction rate calculation unit that calculates a reduction rate for reducing each of the plurality of first luminance signals based on the cumulative value, and a second luminance signal calculation unit that calculates the plurality of second luminance signals based on the reduction rate and the plurality of first luminance signals, and the display unit is driven based on the plurality of second luminance signals.

[0011] These comprehensive or specific aspects may be realized by a system, a method, an integrated circuit, a computer program, or a computer-readable recording medium such as a CD-ROM, or may be realized by any combination of the system, the method, the integrated circuit, the computer program, and the recording medium. The recording medium may be a non-transitory recording medium. Effect of the Invention

[0012] According to the present disclosure, it is possible to provide a method for driving a display device that can extend the lifespan of a plurality of pixels included in the display device while preventing the luminance of the plurality of pixels from decreasing more than necessary. [Brief description of the drawings]

[0013] [Figure 1] 1 is a block diagram showing a configuration example of a display device according to a first embodiment. [Diagram 2] FIG. 2 is a diagram showing an example of a configuration of a pixel set according to the first embodiment. [Diagram 3] 1 is a circuit diagram showing an example of a configuration of a pixel according to a first embodiment. [Figure 4] 2 is a block diagram showing an example of a configuration of a control circuit according to the first embodiment. FIG. [Diagram 5]2 is a block diagram showing a configuration of a conversion unit according to the first embodiment. FIG. [Figure 6] 4 is a graph showing an example of a relationship between normalized luminance and weight according to the first embodiment. [Figure 7] 4 is a graph showing an example of the relationship between an accumulated value and a reduction rate according to the first embodiment. [Figure 8] 5 is a flowchart showing the flow of a method of driving the display device according to the first embodiment. [Figure 9] FIG. 11 is a block diagram showing a configuration of a conversion unit according to the second embodiment. [Figure 10] 13 is a graph showing an example of a relationship between an environmental temperature and a second weight according to the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. Note that each of the embodiments described below shows a specific example of the present disclosure. Therefore, the numerical values, shapes, materials, components, arrangement and connection of the components, steps, and order of steps shown in the following embodiments are merely examples and are not intended to limit the present disclosure.

[0015] In addition, each drawing is a schematic diagram and is not necessarily a precise illustration. In each drawing, the same reference numerals are used for substantially the same configurations, and duplicated explanations are omitted or simplified.

[0016] (Embodiment 1) A display device and a driving method thereof according to a first embodiment will be described with reference to Fig. 1. Fig. 1 is a block diagram showing an example of the configuration of a display device 1 according to the present embodiment.

[0017] In the present embodiment, the display device 1 will be described as an organic EL display.

[0018] The display device 1 is a display including a display unit 10 having a plurality of pixels P. In this embodiment, the actual display luminance of the plurality of pixels P deteriorates over time. Hereinafter, definitions of terms used in this embodiment will be described.

[0019] In this embodiment, the "amount of physical deterioration" refers to the amount of deterioration of the actual display luminance (amount of light emission) over time when a current corresponding to the luminance data obtained from the video signal, i.e., the uncorrected luminance data, is applied to the pixel. The amount of physical deterioration differs between individual pixels.

[0020] In this embodiment, the "decay characteristic of the amount of light emitted" refers to the amount of decay of the actual display luminance over time, which is determined by design. The amount of physical deterioration cannot be controlled by design (it varies depending on the image being displayed), but the decay characteristic of the amount of light emitted can be controlled by design. The decay characteristic of the amount of light emitted is the same for all display pixels.

[0021] [1. Display device configuration] As shown in FIG. 1, the display device 1 includes a display unit 10 and a control circuit 20.

[0022] The display unit 10 includes a display panel 110, a data line driving circuit 120, and a scanning line driving circuit 130. The display unit 10 is driven based on a plurality of correction signals output by a control circuit 20.

[0023] The display panel 110 includes a plurality of pixel sets PS arranged in a matrix, and a plurality of scanning lines GL and a plurality of data lines SL connected to the pixel sets PS.

[0024] The configuration of the pixel set PS will be described with reference to FIG. 2 and FIG. 3. FIG. 2 is a diagram showing an example of the configuration of the pixel set PS according to the present embodiment. FIG. 3 is a circuit diagram showing an example of the configuration of the pixel P according to the present embodiment. The pixel set PS according to the present embodiment has a plurality of pixels P. In the present embodiment, as shown in FIG. 2, the pixel set PS has a red pixel PR, a green pixel PG, and a blue pixel PB. Each of the red pixel PR, the green pixel PG, and the blue pixel PB of the pixel set PS is an example of the pixel P according to the present embodiment. In other words, the display panel 110 has a plurality of pixels P, and the plurality of pixels P include pixels corresponding to a plurality of emission colors. For example, the plurality of pixels P include a plurality of red pixels PR, a plurality of green pixels PG, and a plurality of blue pixels PB.

[0025] In this embodiment, each of the plurality of pixels P includes an organic EL element OEL, a selection transistor T1, a driving transistor T2, and a capacitance element C1, as shown in FIG.

[0026] The selection transistor T1 switches between selected and unselected states of the pixel P in response to a drive signal output from the control circuit 20. The selection transistor T1 is a thin film transistor (TFT) with a gate terminal connected to a scanning line GL, a source terminal connected to a data line SL, and a drain terminal connected to a node N1.

[0027] The driving transistor T2 supplies a driving current to the organic EL element OEL according to the voltage value of the data line SL. The driving transistor T2 is a thin-film transistor, with a gate terminal connected to the node N1, a source terminal connected to the anode electrode of the organic EL element OEL, and a drain terminal supplied with a voltage VTFT from a power supply (not shown).

[0028] The organic EL element OEL is a light-emitting element that emits light in response to a driving current. The driving current is supplied from the driving transistor T2. The organic EL element OEL has an anode electrode connected to the source terminal of the driving transistor T2 and a cathode electrode grounded.

[0029] The capacitive element C1 has one end connected to the node N1 and the other end connected to the source terminal of the driving transistor T2.

[0030] The data line driving circuit 120 supplies voltages corresponding to the multiple correction signals output from the control circuit 20 to the data lines SL.

[0031] The scanning line driving circuit 130 supplies a voltage corresponding to a driving signal output from the control circuit 20 to the scanning lines GL.

[0032] In the present embodiment, the selection transistor T1 and the driving transistor T2 are N-type TFTs, but they may be P-type TFTs. Even in this case, the capacitance element C1 is connected between the gate and source of the driving transistor T2.

[0033] The control circuit 20 is a circuit that controls the display of an image on the display panel 110, and is configured using, for example, a TCON (timing controller) or the like. The control circuit 20 sequentially acquires luminance signals (hereinafter also referred to as first luminance signals) of the plurality of pixels P that constitute the display panel 110 from, for example, a video signal. Furthermore, the control circuit 20 performs correction on each of the first luminance signals. The correction of the first luminance signal is performed, for example, according to the physical deterioration amount of the organic EL element OEL of the pixel P corresponding to the first luminance signal to be corrected and the attenuation characteristic of the amount of light emitted. Hereinafter, the plurality of first luminance signals corrected by the control circuit 20 are referred to as a plurality of correction signals. The control circuit 20 outputs the plurality of correction signals to the data line driving circuit 120. In the following description, the pixel P corresponding to the first luminance signal to be corrected currently processed in the control circuit 20 is referred to as the pixel P to be corrected.

[0034] The control circuit 20 will be described with reference to FIG. 4. FIG. 4 is a block diagram showing an example of the configuration of the control circuit 20 according to the present embodiment. FIG. 4 also shows the display unit 10. As shown in FIG. 4, the control circuit 20 includes a conversion unit 220 and a correction value calculation unit 230.

[0035] The conversion unit 220 is a processing unit that converts a plurality of first luminance signals corresponding to a plurality of pixels P into a plurality of second luminance signals. The conversion unit 220 reduces the first luminance signals at the same reduction rate for all pixels P of the display panel 110. The display unit 10 according to the present embodiment is driven based on a plurality of second luminance signals. Here, the display unit 10 being driven based on a plurality of second luminance signals is not limited to the case where the display unit 10 is driven based on the plurality of second luminance signals themselves, but also includes the case where the display unit 10 is driven based on a plurality of corrected signals obtained by further correcting the plurality of second luminance signals.

[0036] The configuration of conversion unit 220 will be described with reference to Fig. 5. Fig. 5 is a block diagram showing the configuration of conversion unit 220 according to this embodiment. As shown in Fig. 5, conversion unit 220 includes weight calculation unit 221, time counter 222, multiplier 223, cumulative value calculation unit 224, reduction rate calculation unit 225, and multiplier 226.

[0037] More specifically, the conversion unit 220 obtains a first luminance signal from a video signal for causing the display unit 10 to display an image.

[0038] The weight calculation unit 221 is a processing unit that calculates a weight for the lighting time of the display unit 10, which is determined based on a plurality of first luminance signals or a plurality of second luminance signals. In the present embodiment, the weight calculation unit 221 calculates the weight based on the plurality of first luminance signals. More specifically, the weight calculation unit 221 calculates the weight based on an APL (Average Picture Level) of the plurality of first luminance signals. The APL corresponds to an average value of the plurality of first luminance signals. The average value of the APL at a predetermined time may be used as the APL. The weight calculation unit 221 outputs a signal corresponding to the calculated weight to the multiplier 223.

[0039] A method of calculating the weight in the weight calculation unit 221 will be described with reference to FIG. 6. FIG. 6 is a graph showing an example of the relationship between the normalized luminance and the weight according to the present embodiment. In the present embodiment, the normalized luminance is a normalized APL. As shown in FIG. 6, the weight is, for example, a value between 0 and 1, and increases as the normalized luminance increases. The weight calculation unit 221 calculates the weight using, for example, a graph as shown in FIG. 6, a function of the APL and the weight, a lookup table, or the like.

[0040] When the display device 1 is a color display, the weight calculation section 221 may calculate a weight for each emitted color, such as red, green, and blue.

[0041] In the present embodiment, the weight calculation unit 221 calculates the weight based on the APL of the multiple first luminance signals, but the method of calculating the weight in the weight calculation unit 221 is not limited to this. For example, the weight calculation unit 221 may calculate the weight based on the maximum luminance of the multiple first luminance signals. That is, the weight calculation unit 221 may calculate the weight based on the first luminance signal indicating the maximum luminance among the multiple first luminance signals corresponding to one frame. Furthermore, the weight calculation unit 221 may calculate the weight based on the average value of the maximum luminance of the multiple first luminance signals over a predetermined time period.

[0042] Furthermore, the weight calculation unit 221 may calculate the weight based on a plurality of second luminance signals which are output signals of the conversion unit 220. In this case, the plurality of second luminance signals which are output signals of the conversion unit 220 are input to the weight calculation unit 221. For example, the weight calculation unit 221 may calculate the weight based on the APL, maximum luminance, an average value of the maximum luminance in a predetermined time period, etc. of the plurality of second luminance signals.

[0043] Furthermore, the weight calculation unit 221 may calculate the weight based on a signal obtained by further correcting a plurality of second luminance signals. For example, the weight calculation unit 221 may calculate the weight based on a plurality of correction signals that are output signals of the control circuit 20. In this case, the plurality of correction signals that are output signals of the control circuit 20 are input to the weight calculation unit 221. For example, the weight calculation unit 221 may calculate the weight based on the APL, maximum luminance, an average value of the maximum luminance in a predetermined time, and the like of the plurality of correction signals.

[0044] Alternatively, the weight calculation unit 221 may calculate the weight based on both the first luminance signals and the second luminance signals. For example, the weight calculation unit 221 may calculate the weight based on the product of the first luminance signal and the second luminance signal corresponding to each pixel.

[0045] 5 outputs a signal corresponding to an elapsed time. In this embodiment, the time counter 222 outputs a signal to the multiplier 223 every time a predetermined time elapses.

[0046] The multiplier 223 is a processing unit that multiplies a signal corresponding to the weight by a signal corresponding to a predetermined time. The multiplier 223 outputs a signal corresponding to a multiplication result of the signal corresponding to the weight by the signal corresponding to the predetermined time to the cumulative value calculation unit 224. If the display device 1 is a color display, the multiplier 223 may multiply a signal corresponding to the weight for each emitted color, such as red, green, and blue, by a signal corresponding to the predetermined time.

[0047] The cumulative value calculation unit 224 is a processing unit that calculates a cumulative value by accumulating values ​​related to the weights. In this embodiment, the cumulative value calculation unit 224 calculates a value corresponding to the time obtained by multiplying the weight by time, as the cumulative value, and accumulates the value from the time when the display device 1 starts to be driven, and outputs the calculated cumulative value to the reduction rate calculation unit 225. The cumulative value calculated here corresponds to the effective lighting time (driving time) when the pixel P is kept lit at a predetermined luminance. This makes it possible to obtain the effective lighting time according to the actual usage situation of the display device 1. Therefore, it is possible to more accurately predict the degree of deterioration of the pixel P.

[0048] The accumulated value calculated by the accumulated value calculation unit 224 is maintained without being reset even when the driving of the display device 1 is stopped (for example, when the main power supply of the display device 1 is switched from the on state to the off state). If the display device 1 is a color display, the accumulated value calculation unit 224 may calculate the accumulated value for each emitted color, such as red, green, and blue.

[0049] The reduction rate calculation unit 225 calculates a reduction rate for reducing each of the plurality of first luminance signals based on the accumulated value calculated by the accumulated value calculation unit 224. If the display device 1 is a color display, the reduction rate calculation unit 225 may calculate a reduction rate (color-specific reduction rate) for each emitted color, such as red, green, and blue, and output the minimum value among them as the reduction rate. In other words, the reduction rate calculation unit 225 may calculate a plurality of color-specific reduction rates corresponding to the plurality of emitted colors, respectively, and select the minimum color-specific reduction rate among the plurality of color-specific reduction rates as the reduction rate. This makes it possible to determine the reduction rate according to the pixel P of the emitted color that has deteriorated the most, thereby minimizing the progress of deterioration of the pixel P.

[0050] Here, the relationship between the cumulative value and the reduction rate will be described with reference to FIG. 7. FIG. 7 is a graph showing an example of the relationship between the cumulative value and the reduction rate according to the present embodiment. As shown in FIG. 7, the reduction rate calculated by the reduction rate calculation unit 225 becomes smaller as the cumulative value increases. The reduction rate is determined based on the deterioration characteristics of the multiple pixels P, that is, the attenuation characteristics of the amount of light emitted. For example, the reduction rate may be determined based on the deterioration characteristics of a pixel P having intermediate deterioration characteristics between the most deteriorated pixel P and the least deteriorated pixel P among the multiple pixels P. In other words, the relationship between the cumulative value and the reduction rate may be determined based on the relationship between the lighting time when the pixel P is continuously lit at an assumed luminance and the actual display luminance. Thereby, by reducing the luminance, it is possible to suppress the deterioration of the multiple pixels P while suppressing the luminance of the display unit 10 from being reduced more than necessary. In addition, in determining the reduction rate, the reduction rate corresponding to the effective lighting time can be determined by using the cumulative value of the value related to the weight, not the lighting time of the multiple pixels P. Therefore, the reduction rate can be determined based on the degree of deterioration of the multiple pixels P that is more accurately estimated. This makes it possible to prevent the attractiveness of the display device 1 from being reduced by unnecessarily lowering the luminance of multiple pixels P, and to prevent the lifespan of the display device 1 from being shortened by unnecessarily increasing the luminance compared to the degree of deterioration of the multiple pixels P.

[0051] The multiplier 226 is an example of a second luminance signal calculation unit that calculates a plurality of second luminance signals based on the reduction rate and a plurality of first luminance signals. The multiplier 226 calculates a plurality of second luminance signals by multiplying a signal corresponding to the reduction rate output by the reduction rate calculation unit 225 by the plurality of first luminance signals.

[0052] 4 calculates a correction signal by correcting the second luminance signal according to the amount of deterioration for each pixel P. The correction value calculation unit 230 includes multipliers 231, 232, and 234, a deterioration amount calculation unit 233, and a corrected gradation calculation unit 235. The operation of each component of the correction value calculation unit 230 will be described later.

[0053] [2. Driving method] A method for driving the display device 1 in this embodiment will be described with reference to Fig. 8. Fig. 8 is a flowchart showing the flow of the method for driving the display device 1 according to this embodiment.

[0054] As shown in FIG. 8, first, the conversion unit 220 of the control circuit 20 converts a plurality of first luminance signals corresponding to a plurality of pixels P into a plurality of second luminance signals (conversion step S10).

[0055] In the conversion step S10, the weight calculation section 221 of the conversion section 220 calculates a weight for the lighting time of the display section, which is determined based on a plurality of first luminance signals or a plurality of second luminance signals (weight calculation step S11).

[0056] Next, the cumulative value calculation unit 224 calculates a cumulative value by accumulating values ​​related to the weights (accumulation value calculation step S12). In this embodiment, the cumulative value calculation unit 224 calculates, as the cumulative value, a value corresponding to a time obtained by multiplying the weights by time, and accumulating the value from the time when the display device 1 starts to be driven.

[0057] Next, the reduction rate calculation unit 225 calculates a reduction rate for reducing each of the plurality of first luminance signals based on the accumulated value (reduction rate calculation step S13).

[0058] Next, the multiplier 226, which is an example of a second luminance signal calculation section, calculates a plurality of second luminance signals based on the reduction rate and the plurality of first luminance signals (second luminance signal calculation step S14).

[0059] Next, the correction value calculation unit 230 calculates a plurality of correction signals by correcting the plurality of second luminance signals (correction value calculation step S20). Hereinafter, an example of the operation of the correction value calculation unit 230 in the correction value calculation step S20 will be described with reference to FIG.

[0060] The correction value calculation section 230 calculates a correction signal to be given to the pixel P to be corrected so that the actual display luminance of the pixel P to be corrected becomes the same as the actual display luminance of the reference pixel to which the second luminance signal is given.

[0061] 4, the multiplier 231 multiplies the second luminance signal by (1 / η0). Here, the actual display luminance of the undegraded pixel P (i.e., the actual display luminance L at the initial stage (i.e., when the display device 1 starts to be driven)) is expressed as η0×I, where I is a current value (corresponding to the luminance signal).

[0062] Multiplier 232 multiplies the output signal (L / η0) from multiplier 231 by (1 / Δη) calculated by degradation amount calculation unit 233, which will be described later. The remaining rate Δη is the ratio of the current actual display luminance to the initial actual display luminance in pixel P to be corrected. Note that the multiplication result L / (η0×Δη) of multiplier 232 is equivalent to the current value that needs to be passed through pixel P in order to obtain the actual display luminance in the initial state in display panel 110.

[0063] The deterioration amount calculation unit 233 calculates a remaining rate (=1-deterioration rate) using the multiplication result in the multiplier 232. The remaining rate is an example of the deterioration amount, and is defined, for example, using a ratio of a remaining actual display luminance, which is a current actual display luminance of the pixel P, to an initial actual display luminance of the pixel P, (remaining actual display luminance / initial actual display luminance).

[0064] The deterioration amount is calculated from the amount of current that actually flows through the pixel P, but since it is difficult to measure the amount of current directly, in this embodiment, the deterioration amount is calculated by calculation. Specifically, for example, the deterioration amount is calculated from the multiplication result L / (η0×Δη) in the multiplier 232.

[0065] The multiplier 234 multiplies the second luminance signal by (1 / Δη) calculated by the degradation amount calculation unit 233.

[0066] The corrected gray scale calculation unit 235 converts the luminance signal L / Δη, which has been adjusted so that the initial actual display luminance L is generated in the deteriorated organic EL element OEL, into a gray scale to be specifically set in the display unit 10. The relationship between the gray scale and the luminance is set in advance, and the corrected gray scale calculation unit 235 selects a gray scale corresponding to the luminance signal L / Δη. The corrected gray scale calculation unit 235 outputs a plurality of correction signals corresponding to the selected gray scale to the display unit 10.

[0067] Next, the control circuit 20 inputs the plurality of correction signals to the display unit 10, thereby driving the display unit 10 based on the plurality of correction signals (driving step S30).

[0068] By repeating the same operation thereafter, it is possible to cause a plurality of pixels P of the display unit 10 to emit light at luminances corresponding to a plurality of second luminance signals.

[0069] [3. Effects, etc.] The driving method of the display device 1 of the present embodiment is a driving method of the display device 1 including a display unit 10 having a plurality of pixels P, and includes a conversion step S10 of converting a plurality of first luminance signals corresponding to the plurality of pixels P into a plurality of second luminance signals, and a drive step S30 of driving the display unit 10 based on the plurality of second luminance signals. The conversion step S10 includes a weight calculation step S11 of calculating a weight for a lighting time of the display unit 10 determined based on the plurality of first luminance signals or the plurality of second luminance signals, an accumulation value calculation step S12 of calculating an accumulation value obtained by accumulating values ​​related to the weight, a reduction rate calculation step S13 of calculating a reduction rate for reducing each of the plurality of first luminance signals based on the accumulation value, and a second luminance signal calculation step S14 of calculating a plurality of second luminance signals based on the reduction rate and the plurality of first luminance signals.

[0070] As a result, in determining the reduction rate, a reduction rate corresponding to an effective lighting time can be determined by using an accumulated value of the weighting value instead of the lighting time of the multiple pixels P. Therefore, the reduction rate can be determined based on a more accurately estimated degree of deterioration of the multiple pixels P. As a result, it is possible to prevent the attractiveness of the display device 1 from being reduced by unnecessarily reducing the luminance of the multiple pixels P, and the lifespan of the display device 1 from being shortened by unnecessarily increasing the luminance compared to the degree of deterioration of the multiple pixels P.

[0071] In addition, in the weight calculation step S11, the weight may be calculated based on the APL of a plurality of first luminance signals or a plurality of second luminance signals.

[0072] This makes it possible to accurately calculate the weights corresponding to the effective lighting times of all of the pixels P.

[0073] In addition, in the weight calculation step S11, the weight may be calculated based on the maximum luminance of the plurality of first luminance signals or the plurality of second luminance signals.

[0074] This makes it possible to accurately calculate the weight corresponding to the effective lighting time of the pixel P that has the greatest load (that is, is most susceptible to deterioration) among all the multiple pixels P.

[0075] In addition, in the weight calculation step S11, the weight may be calculated based on an average value of maximum luminance of a plurality of first luminance signals or a plurality of second luminance signals in a predetermined time period.

[0076] This makes it possible to accurately calculate a weight corresponding to the effective lighting time of the pixel P with the greatest load (i.e., the pixel P most susceptible to deterioration) among all the pixels P. Furthermore, by calculating the weight based on the average value of the maximum luminance for a predetermined time, it is possible to prevent the weight from failing to represent the effective lighting time of the pixel P due to a large temporary fluctuation in luminance.

[0077] Furthermore, in the reduction rate calculation step S13, a plurality of color reduction rates respectively corresponding to a plurality of emitted colors may be calculated, and the smallest color reduction rate among the plurality of color reduction rates may be selected as the reduction rate.

[0078] This makes it possible to determine the reduction rate in accordance with the pixel P of the luminescent color that has deteriorated the most, thereby minimizing the progression of pixel deterioration.

[0079] The display device 1 of the present embodiment includes a display unit 10 having a plurality of pixels P. The display unit 10 includes a conversion unit 220 that converts a plurality of first luminance signals corresponding to the plurality of pixels P into a plurality of second luminance signals. The conversion unit 220 includes a weight calculation unit 221 that calculates a weight for a lighting time of the display unit 10, which is determined based on the plurality of first luminance signals or the plurality of second luminance signals, an accumulation value calculation unit 224 that calculates an accumulation value obtained by accumulating values ​​related to the weight, a reduction rate calculation unit 225 that calculates a reduction rate for reducing each of the plurality of first luminance signals based on the accumulation value, and a second luminance signal calculation unit (multiplier 226) that calculates a plurality of second luminance signals based on the reduction rate and the plurality of first luminance signals. The display unit 10 is driven based on the plurality of second luminance signals.

[0080] This provides the same effects as the method for driving the display device 1 according to the present embodiment.

[0081] (Embodiment 2) A method for driving the display device according to the second embodiment will be described. The method for driving the display device according to the present embodiment differs from the method for driving the display device 1 according to the first embodiment in that the weight calculation takes into account not only the luminance signal but also the environmental temperature. The method for driving the display device according to the present embodiment will be described below, focusing on the differences from the method for driving the display device 1 according to the first embodiment.

[0082] A display device according to the present embodiment will be described. The display device according to the present embodiment differs from the display device 1 according to the first embodiment in the configuration of the conversion unit. The conversion unit according to the present embodiment will be described with reference to Fig. 9. Fig. 9 is a block diagram showing the configuration of a conversion unit 1220 according to the present embodiment.

[0083] As shown in FIG. 9, conversion section 1220 according to this embodiment includes weight calculation section 1221, time counter 222, multiplier 223, cumulative value calculation section 224, reduction rate calculation section 225, and multiplier 226.

[0084] The weight calculation unit 1221 according to the present embodiment calculates the weight based on a plurality of first luminance signals or a plurality of second luminance signals and the environmental temperature of the display device. The environmental temperature means the temperature of the environment in which the display device is placed. In other words, in the driving method for the display device according to the present embodiment, in the weight calculation step, the weight is calculated based on a plurality of first luminance signals or a plurality of second luminance signals and the environmental temperature of the display device.

[0085] The weight calculation unit 1221 acquires information corresponding to the environmental temperature. The information corresponding to the environmental temperature may be acquired by the display device, or may be acquired by the weight calculation unit 1221 from outside the display device. For example, the conversion unit 1220 may include a temperature detector that acquires information corresponding to the environmental temperature.

[0086] The weight calculation unit 1221 calculates the weight in the same manner as the weight calculation unit 221 according to the first embodiment, for example, based on a plurality of first luminance signals or a plurality of second luminance signals. In this embodiment, the weight calculated based on a plurality of first luminance signals or a plurality of second luminance signals is referred to as a first weight. In addition, the weight calculation unit 1221 calculates the second weight based on the environmental temperature. Here, a method of calculating the weight in the weight calculation unit 221 will be described with reference to FIG. 10. FIG. 10 is a graph showing an example of the relationship between the environmental temperature and the second weight according to this embodiment. As shown in FIG. 10, the second weight is, for example, a value of about 0 to 10, and increases as the environmental temperature increases. The weight calculation unit 1221 calculates the second weight using, for example, a graph as shown in FIG. 10, a function of the environmental temperature and the second weight, a lookup table, or the like. The weight calculation unit 1221 outputs, for example, the product of the first weight and the second weight as the weight.

[0087] As described above, in the method for driving a display device according to the present embodiment, in the weight calculation step, the weight is calculated based on the environmental temperature of the display device.

[0088] In pixels using organic EL elements, the higher the environmental temperature, the more likely the deterioration will progress. Therefore, by calculating weights based on the environmental temperature as in the present embodiment, the deterioration of multiple pixels can be estimated with greater accuracy. Therefore, it becomes possible to calculate a more appropriate reduction rate.

[0089] In this embodiment, the weight calculation unit 1221 calculates the weight based on the multiple first luminance signals and the environmental temperature, but the weight may be calculated based only on the environmental temperature. That is, the weight calculation unit 1221 may output the above-mentioned second weight as the weight. Even with such a configuration, the deterioration of multiple pixels can be accurately estimated. Such a configuration is particularly effective when the multiple first luminance signals are close to an expected value and have small fluctuations.

[0090] (Modifications of the embodiment, etc.) Although the display device and the driving method thereof according to the above-mentioned aspect have been described based on the embodiment, the present disclosure is not limited to this embodiment. As long as it does not deviate from the gist of the present disclosure, various modifications conceived by a person skilled in the art to the present embodiment and forms constructed by combining the components in the embodiment and the modifications may also be included within the scope of one or more aspects.

[0091] For example, the weight calculation method by the weight calculation unit 1221 according to the second embodiment may be combined with each of the configurations described in the first embodiment.

[0092] Furthermore, the circuit configuration of the pixels P is not limited to the example shown in Fig. 3. As the circuit configuration of the pixels P, other known circuit configurations may be applied.

[0093] In the above embodiment, the video signal is an RGB signal, but the video signal may include signals other than the RGB signal. In other words, the video signal may include an RGB signal.

[0094] Furthermore, the video signal is not limited to a signal including an RGB signal, and may be, for example, a color difference signal including a luminance signal.

[0095] In the above embodiment, the organic EL elements are used as the self-luminous elements, but the self-luminous elements are not limited to this. For example, quantum dots, inorganic EL elements, etc. may be used as the self-luminous elements.

[0096] Furthermore, some of the components constituting the display device (particularly the control circuit) according to each of the above embodiments may be a computer system composed of a microprocessor, a ROM, a RAM, a hard disk unit, etc. A computer program is stored in the RAM or the hard disk unit. The microprocessor operates according to the computer program to achieve its function. Here, the computer program is composed of a combination of multiple instruction codes indicating commands to a computer to achieve a predetermined function.

[0097] Furthermore, some of the components constituting the display device according to each of the above-mentioned embodiments may be composed of one system LSI (Large Scale Integration). The system LSI is a super multi-function LSI manufactured by integrating a plurality of components on one chip, and specifically, is a computer system including a microprocessor, a ROM, a RAM, etc. A computer program is stored in the RAM. The microprocessor operates according to the computer program, and the system LSI achieves its functions.

[0098] Further, some of the components constituting the display device according to each of the above embodiments may be composed of an IC card or a standalone module that is detachable from each device. The IC card or the module is a computer system composed of a microprocessor, ROM, RAM, etc. The IC card or the module may include the ultra-multifunction LSI. The microprocessor operates according to a computer program, causing the IC card or the module to achieve its functions. The IC card or the module may be tamper-resistant.

[0099] Furthermore, some of the components constituting the display device according to each of the above-mentioned embodiments may be the above-mentioned computer program or the above-mentioned digital signal recorded on a computer-readable recording medium, such as a flexible disk, a hard disk, a CD-ROM, an MO, a DVD, a DVD-ROM, a DVD-RAM, a BD (Blu-ray (registered trademark) Disc), a semiconductor memory, etc. Also, they may be the above-mentioned digital signal recorded on such a recording medium.

[0100] In addition, some of the components constituting the display device in each of the above embodiments may transmit the computer program or the digital signal via a telecommunications line, a wireless or wired communication line, a network such as the Internet, data broadcasting, etc.

[0101] The present disclosure may also be realized as the above-described methods. The present disclosure may also be realized as a computer program for implementing these methods by a computer, or as a digital signal comprising the above-described computer program. Furthermore, the present disclosure may also be realized as a non-transitory computer-readable recording medium, such as a CD-ROM, on which the computer program is recorded.

[0102] The present disclosure may also provide a computer system having a microprocessor and a memory, the memory storing the computer program, and the microprocessor operating in accordance with the computer program.

[0103] In addition, the program or the digital signal may be implemented by another independent computer system by recording it on the recording medium and transferring it, or by transferring the program or the digital signal via the network or the like.

[0104] The above-described embodiments and modifications may be combined with each other. [Industrial Applicability]

[0105] The display device driving method and the display device of the present disclosure are useful in technical fields such as flat-screen televisions and personal computer displays. [Explanation of symbols]

[0106] 1 Display device 10 Display 20 Control circuit 110 Display Panel 120 Data line driver circuit 130 Scanning line driving circuit 220, 1220 conversion unit 221, 1221 Weight calculation unit 222 Hour Counter 223, 226, 231, 232, 234 multipliers 224 Accumulative value calculation unit 225 Reduction rate calculation section 230 Correction value calculation unit 233 Deterioration amount calculation section 235 Correction tone calculation unit C1 Capacitive element GL scanline N1 Node OEL Organic EL element P pixels PB Blue pixel PG Green pixel PR Red pixel PS Pixel Set SL Data Line T1 Select Transistor T2 drive transistor

Claims

1. A method for driving a display device including a display unit having a plurality of pixels, comprising the steps of: a conversion step of converting a plurality of first luminance signals corresponding to the plurality of pixels into a plurality of second luminance signals; a driving step of driving the display unit based on the plurality of second luminance signals; The conversion step includes: a weight calculation step of calculating a weight for a lighting time of the display unit, the weight being determined based on the plurality of first luminance signals or the plurality of second luminance signals; an accumulation value calculation step of calculating an accumulation value by accumulating the values ​​related to the weights; a reduction rate calculation step of calculating a reduction rate for reducing each of the plurality of first luminance signals based on the cumulative value; and calculating the plurality of second luminance signals based on the reduction rate and the plurality of first luminance signals. A method for driving a display device.

2. In the weight calculation step, the weight is calculated based on an average picture level (APL) of the first luminance signals or the second luminance signals. The method for driving the display device according to claim 1 .

3. In the weight calculation step, based on the maximum luminance of the plurality of first luminance signals or the plurality of second luminance signals, The method for driving the display device according to claim 1 .

4. In the weight calculation step, the weight is calculated based on an average value of the maximum luminance over a predetermined time period. The method for driving the display device according to claim 3 .

5. In the weight calculation step, the weight is calculated based on an environmental temperature of the display device. A method for driving a display device according to any one of claims 1 to 4.

6. the plurality of pixels include pixels corresponding to a plurality of emission colors, In the reduction rate calculation step, a plurality of color reduction rates corresponding to the plurality of emission colors are calculated, and the smallest color reduction rate among the plurality of color reduction rates is selected as the reduction rate. A method for driving a display device according to any one of claims 1 to 4.

7. A display device including a display unit having a plurality of pixels, a conversion unit that converts a plurality of first luminance signals corresponding to the plurality of pixels into a plurality of second luminance signals; The conversion unit is a weight calculation unit that calculates a weight for a lighting time of the display unit, the weight being determined based on the plurality of first luminance signals or the plurality of second luminance signals; an accumulation value calculation unit that calculates an accumulation value by accumulating values ​​related to the weights; a reduction rate calculation unit that calculates a reduction rate for reducing each of the plurality of first luminance signals based on the cumulative value; a second luminance signal calculation unit that calculates the second luminance signals based on the reduction rate and the first luminance signals, The display unit is driven based on the plurality of second luminance signals. Display device.

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