Source driver and display device including the same

Abstract

Disclosed is a source driver and a display device including the source driver, the source driver sensing the degradation degree of pixels in some areas of a display panel by considering the characteristic that pixels included in each display panel are similarly degraded, and compensating the degradation in the display panel based on the sensed degradation degree. The display device may include: a display panel including pixels; a sensing circuit configured to provide sensing data by sensing the degradation degree of pixels in at least one first area of ​​the display panel; and a compensation circuit configured to calculate a compensation amount for each pixel in the first area using the sensing data, and compensate for the degradation of the pixels in the first area and the degradation of the pixels in the second area where the degradation degree is not sensed based on the compensation amount.

Description

Technical Field

[0001] The present disclosure relates to a display device, and more particularly, to a source driver for sensing degradation levels of some pixels in a display panel and compensating for degradation of the display panel based on the sensed degradation levels, and a display device including the source driver. Background Art

[0002] Typically, a display device includes a display panel, a source driver, a timing controller, and the like.

[0003] The source driver converts the digital video data provided by the timing controller into a data voltage and provides the data voltage to the display panel. The source driver can be integrated in a chip form, and a plurality of source drivers can be configured by considering the size and resolution of the display panel.

[0004] Furthermore, in order to compensate for degradation in the display panel, the source driver senses a signal of each pixel, converts the signal into digital data, and provides the digital data to the timing controller.

[0005] The display device according to the conventional technology senses the degradation degree of the pixels of all channels in order to sense the degradation degree of the display panel. However, the problem of the conventional technology is that since a sensing circuit must be included for each of all channels in order to sense the degradation degree of the pixels of the channel, the chip area of ​​the source driver is increased.

[0006] In addition, in some cases, conventional techniques measure the time that a display panel has been used and compensate for degradation in the display panel based on the measured time. In this case, since only the measured time is used to compensate for degradation of the pixel without sensing the degradation of the pixel, there is a problem that degradation of the pixel in the display panel is not accurately compensated. Summary of the invention

[0007] Various embodiments are directed to providing a source driver and a display device including the same, wherein the source driver is used to sense degradation levels of some pixels in a display panel and compensate for degradation of the display panel based on the sensed degradation levels.

[0008] In an embodiment, a display device may include: a display panel including pixels; a sensing circuit configured to provide sensing data by sensing a degree of degradation of pixels in at least one first region of the display panel; and a compensation circuit configured to calculate a compensation amount for each pixel in the first region using the sensing data, and compensate for degradation of the pixels in the first region and degradation of the pixels in a second region where the degree of degradation is not sensed based on the compensation amount. The compensation circuit may compensate for degradation of the pixels in the first region and the second region using at least one of a minimum value of the compensation amount, an average value of the compensation amount, and a maximum value of the compensation amount according to a difference between a minimum value of the compensation amount and a maximum value of the compensation amount.

[0009] In an embodiment, a display device may include: a display panel including pixels; a source driver configured to provide a data voltage to the display panel based on image data, and provide sensing data by sensing a degree of degradation of pixels in at least one first region of the display panel; and a controller configured to calculate a compensation amount for each pixel in the first region using the sensing data, generate compensation data for compensating for degradation of pixels in the first region and degradation of pixels in a second region where the degree of degradation is not sensed based on the compensation amount, and correct the image data using the compensation data. The controller may compensate for degradation of pixels in the first region and the second region using at least one of a minimum value of the compensation amount, an average value of the compensation amount, and a maximum value of the compensation amount according to a difference between a minimum value of the compensation amount and a maximum value of the compensation amount.

[0010] In an embodiment, a source driver may include: a data driver configured to provide a data voltage to a display panel based on image data; a sensing circuit configured to provide sensing data by sensing a degree of degradation of a pixel in at least one first region of the display panel; and a compensation circuit configured to calculate a compensation amount for each pixel in the first region using the sensing data, generate compensation data for compensating for degradation of the pixel in the first region and degradation of the pixel in the second region where the degree of degradation is not sensed based on the compensation amount, and correct an input image signal using the compensation data. The compensation circuit may compensate for degradation of the pixels in the first region and the second region using at least one of a minimum value of the compensation amount, an average value of the compensation amount, and a maximum value of the compensation amount according to a difference between a minimum value of the compensation amount and a maximum value of the compensation amount. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 is a diagram schematically describing a method of compensating for degradation in a display device according to an embodiment.

[0012] Figure 2 is a block diagram of a display device according to an embodiment.

[0013] Figure 3is a flow chart describing operating a display device to compensate for degradation according to an embodiment.

[0014] Figure 4 is a schematic diagram showing selection of a region in a display panel where a degree of degradation is to be preferentially sensed. DETAILED DESCRIPTION

[0015] Exemplary embodiments will be described in more detail below with reference to the accompanying drawings. However, the present disclosure can be implemented in different forms and should not be construed as being limited to the embodiments set forth herein. On the contrary, these embodiments are provided so that the present disclosure will be thorough and complete, and the scope of the present disclosure will be fully conveyed to those skilled in the art. Throughout the disclosure, in each of the drawings and embodiments of the present disclosure, the same reference numerals refer to the same parts.

[0016] An embodiment discloses a source driver and a display device including the source driver, which senses the degree of degradation of pixels in some areas of a display panel by considering characteristics that pixels included in each display panel are similarly degraded, and compensates for the degradation in the display panel based on the sensed degree.

[0017] In an embodiment, the first region may be defined as a region where the degree of degradation is sensed. The second region may be defined as a region where the degree of degradation is not sensed. In this case, the first region may be divided into a plurality of regions.

[0018] In an embodiment, the accumulated data is the accumulated data of the image data, and can be defined as the accumulated data of the image data from the previous frame to the current frame. In this case, if the amount of accumulated data is large, it may mean that the amount of light emitted by the organic light emitting diode (OLED) of each pixel is large and the OLED has been severely degraded.

[0019] Embodiments may use the accumulated data as a criterion for selecting a first region in which the degree of degradation is to be sensed among regions of the display panel.

[0020] Figure 1 is a diagram schematically describing a method of compensating for degradation in a display device according to an embodiment.

[0021] Reference Figure 1 , an embodiment discloses a display device for sensing the degree of degradation of pixels in at least one first region R1 of a display panel 110, and compensating for the degradation of the pixels in the first region R1 and the degradation of the pixels in the second region R2 where the degree of degradation is not sensed based on the degree of degradation of the pixels in the first region R1.

[0022] According to an embodiment, since the degree of degradation of the pixels in the first region R1 of the display panel 110 is sensed, it is not necessary to include a sensing circuit for each of all channels. Therefore, the chip area of ​​the source driver can be reduced. For example, the display panel 110 may include N vertical pixels and M horizontal pixels. According to an embodiment, if the first region R1 is divided into three regions and the degree of degradation of the pixels in the three regions is sensed, since only sensing circuits for three channels connected to the three regions are required, the chip area of ​​the source driver can be reduced.

[0023] Figure 2 is a block diagram of a display apparatus 100 according to an embodiment.

[0024] Reference Figure 2 , the display device 100 may include a display panel 110 , a source driver 120 , and a controller 130 .

[0025] The display panel 110 may be a region where an image is displayed. The display panel 110 may include gate lines (not shown), data lines DL1 to DLn intersecting the gate lines, and pixels defined by the gate lines and the data lines DL1 to DLn.

[0026] Each pixel may include a driving transistor and an OLED. Each pixel may emit light having a brightness corresponding to a data voltage provided by each data line in response to a scan signal provided by each gate line. In addition, the degree of degradation of the driving transistor and the OLED of each pixel may be sensed by a transistor turned on by a sensing control line (not shown).

[0027] The display panel 110 may be divided into a first region R1 where the degradation degree is sensed and a second region R2 where the degradation degree is not sensed. In addition, the first region R1 may be divided into a plurality of regions. For example, the first region R1 may be selected based on accumulated data of image data accumulated in units of frames.

[0028] The source driver 120 provides a data voltage to the display panel 110 based on the image data DATA, and provides sensing data SD to the controller 130 by sensing a degree of degradation of pixels in at least one first region R1 of the display panel 110 .

[0029] The source driver 120 may be coupled to the data lines of the display panel 110. The source driver 120 may change the image data DATA into a data voltage in response to the driving control signal CON. The source driver 120 may provide the data voltage to the display panel 110 through the data lines DL1 to DLn.

[0030] The source driver 120 may include a sensing circuit 10 for sensing the degree of degradation of the pixels in the first region R1. The sensing circuit 10 may provide the controller 130 with sensing data SD corresponding to the degree of degradation of each pixel in the first region R1.

[0031] The sensing circuit 10 may include a sample-and-hold circuit (not shown) coupled to the data lines DL1 to DLn, and may sample the amount of current flowing into the OLED of each pixel through each data line DL1 to DLn. The sensing circuit 10 may convert the amount of current flowing into the OLED of each pixel into sensing data SD (ie, a digital value).

[0032] The controller 130 may calculate a compensation amount for each pixel in the first region R1 using the sensing data SD, and may generate compensation data for compensating for degradation of pixels in the first region R1 and degradation of pixels in the second region R2 where the degree of degradation is not sensed based on the calculated compensation amount.

[0033] In addition, the controller 130 may correct the image data DATA using the compensation data, and may provide the corrected data to the source driver 120 .

[0034] The controller 130 may receive a control signal CS and an image signal RGB from a host system. In this case, the image signal RGB may include brightness and color information of a pixel. The control signal CS may include a vertical synchronization signal, a horizontal synchronization signal, an enable signal, and a clock signal.

[0035] The controller 130 may generate a driving control signal CON and image data DATA in response to the control signal CS and the image signal RGB. The controller 130 may classify the image signal RGB in units of frames in response to the vertical synchronization signal, may classify the image signal RGB in units of scan lines in response to the horizontal synchronization signal, and may generate the image data DATA based on the classification result.

[0036] The controller 130 may generate compensation data for correcting the image data DATA using the sensing data SD, and may provide the corrected image data DATA to the source driver 120 .

[0037] The controller 130 may include a compensation circuit 20. The compensation circuit 20 may calculate a compensation amount corresponding to a degree of degradation in each pixel using the sensing data SD, may generate compensation data using the compensation amount, and may correct the image data DATA using the compensation data.

[0038] When the difference between the minimum and maximum values ​​of the compensation amount of the pixels in the first region R1 is less than the reference value, the compensation circuit 20 may compensate for the degradation of the pixels in the first region R1 and the second region R2 using at least one of the minimum, average and maximum values ​​of the compensation amount of the pixels in the first region R1.

[0039] When the difference between the minimum and maximum values ​​of the compensation amount of the pixels in the first region R1 is a reference value or greater, the compensation circuit 20 may compensate for the degradation of the pixels in the first region R1 based on a compensation amount in which a gradient weight is applied to surrounding pixels based on a pixel having a maximum value of the compensation amount, and may compensate for the degradation of the pixels in the second region using at least one of the minimum, average and maximum values ​​of the compensation amount of the pixels in the first region R1.

[0040] The compensation circuit 20 may accumulate image data in units of frames, and may select the first region R1 based on the accumulated data. The compensation circuit 20 may control to periodically sense the degree of degradation of the pixels in the selected first region R1.

[0041] The compensation circuit 20 may include: a region selection module for accumulating image data DATA and selecting a first region R1 based on the accumulated data; a compensation amount calculation module for calculating a compensation amount for each pixel in the first region using sensing data of the first region R1; and a compensation module for generating compensation data based on the compensation amount and correcting the image data using the compensation data.

[0042] The compensation circuit 20 may control the image data DATA from the previous frame to the current frame to be accumulated for each pixel, select the first region R1 based on the accumulated data, and sense the degree of degradation of the pixels in the first region R1. In this case, if the amount of accumulated data is large, this may mean that the OLED of each pixel emits a large amount of light and the OLED or driving transistor of each pixel has been severely degraded. The accumulated data accumulated in the pixel may be different for each pixel.

[0043] The compensation circuit 20 may select the first region R1 by analyzing the accumulated data of each pixel.

[0044] In addition, the compensation circuit 20 may prevent the occurrence of brightness deviation by sensing the degree of degradation of surrounding pixels based on the pixel that has been severely degraded and by correcting the image data DATA.

[0045] Figure 3 is a flow chart describing operating a display device to compensate for degradation according to an embodiment.

[0046] Reference Figure 3, the controller 130 may control the source driver 120 to sense the degradation degree of the pixels in the first region R1 of the display panel 110 (S10). For example, the controller 130 may select a region with a predicted degradation degree greater than that of other regions as the first region R1 based on the accumulated data of the image data from the previous frame to the current frame.

[0047] Next, the controller 130 may receive sensing data SD corresponding to the degradation degree of the pixels in the first region R1 from the source driver 120 (S20). For example, the source driver 120 may sense the degradation degree of the pixels in the first region R1 through the data line coupled to the first region R1 in response to the driving control signal CON from the controller 130, may convert the sensed degradation degree into sensing data SD (i.e., a digital value), and may provide the sensing data SD to the controller 130.

[0048] Next, the controller 130 may calculate the compensation amount of each pixel in the first region R1 based on the sensing data SD (S30). For example, the controller 130 may calculate the compensation amount using a lookup table consisting of the sensing data SD relative to the compensation amount, or may calculate the compensation amount using a relational expression with the sensing data SD as a variable.

[0049] Next, the controller 130 may compare a difference between the minimum value and the maximum value of the compensation amount with a reference value to check whether the difference is the reference value or more ( S40 ).

[0050] This comparison can be used to distinguish between a case where the pixels of the display panel 110 are similarly degraded and a case where the pixels of the display panel 110 are differently degraded. For example, if the pixels of the display panel 110 are similarly degraded, the controller 130 can sense the degree of degradation of the pixels in some areas of the display panel and compensate for the degradation in the display panel based on the sensed degree of degradation. For another example, if the pixels of the display panel 110 are differently degraded, the controller 130 can compensate for the degradation in the display panel by applying gradient weights to surrounding pixels based on pixels that are expected to have been severely degraded.

[0051] When the difference between the minimum and maximum values ​​of the compensation amount is less than the reference value, the controller 130 may compensate for degradation of pixels in the first and second regions R1 and R2 using at least one of the minimum, average, and maximum values ​​of the compensation amount of the pixels in the first region R1 (S50).

[0052] On the contrary, when the difference between the minimum value and the maximum value of the compensation amount is the reference value or greater, the controller 130 may compensate for the degradation of the pixels in the first region R1 based on such a compensation amount, which is a compensation amount based on the pixel having the maximum value of the compensation amount applying the gradient weight to the surrounding pixels, and may compensate for the degradation of the pixels in the second region R2 using at least one of the minimum value, the average value and the maximum value of the compensation amount of the pixels in the first region R1 (S60).

[0053] Figure 4 is a schematic diagram showing selection of a region in a display panel where a degree of degradation is to be preferentially sensed.

[0054] For example, according to an embodiment, image data to be provided to the source driver may be accumulated in units of frames. A region whose degradation degree is expected to be greater than that of other regions may be selected based on the accumulated data from the previous frame to the current frame.

[0055] In addition, according to an embodiment, brightness and color with high usage frequency may be analyzed based on accumulated data. The degree of degradation of pixels may be periodically sensed in an area where degradation often occurs.

[0056] In addition, according to the implementation mode, Figure 4 As shown, when the difference between the degradation degrees of region A and region B is a reference value or more, the degradation of the surrounding pixels may be compensated according to a compensation amount in which a gradient weight is applied to the surrounding pixels based on region A having the maximum value of the compensation amount. In such an embodiment, if pixels degrade differently, the degradation in the display panel may be compensated by applying a gradient weight to the surrounding pixels based on pixels predicted to be severely degraded.

[0057] As described above, since the sensing circuit only requires a channel for coupling to a region where the degree of degradation of pixels in the display panel is to be sensed, embodiments can reduce the chip area of ​​the source driver.

[0058] Since the degree of pixel degradation in some areas of the display panel is sensed, the embodiments can reduce the sensing time and improve the compensation accuracy of degradation compared to the conventional technology that compensates for degradation based only on the usage time.

[0059] Although various embodiments have been described above, those skilled in the art will appreciate that the described embodiments are only exemplary. Therefore, the disclosure described herein should not be limited based on the described embodiments.

Claims

1. A display device, comprising: a display panel including pixels and divided into at least one first region where degradation is sensed and at least one second region where degradation is not sensed, wherein a region where degradation is expected to be greater than degradation of other regions is selected as the at least one first region based on accumulated image data from a previous frame to a current frame, wherein each of the at least one first region and the at least one second region includes at least one entire column of pixels arranged along a vertical direction of the display panel; a sensing circuit configured to provide sensing data by sensing a degree of degradation of pixels in at least one first region of the display panel and not sensing a degree of degradation of pixels in the at least one second region of the display panel; as well as a compensation circuit configured to calculate a compensation amount for each of the pixels in the first region using the sensing data, and to compensate for degradation of the pixels in the first region and degradation of the pixels in the second region based on the compensation amount, wherein, when a difference between a minimum value of the compensation amount and a maximum value of the compensation amount is less than a reference value, the compensation circuit compensates for degradation of the pixels in the first area and the second area using at least one of the minimum value of the compensation amount, the average value of the compensation amount, and the maximum value of the compensation amount, Wherein, when the difference is equal to or greater than a reference value, the compensation circuit compensates for the degradation of the pixels in the first area by applying a compensation amount of a gradient weight to surrounding pixels based on a pixel having the maximum value of the compensation amount, and compensates for the degradation of the pixels in the second area using at least one of the minimum value of the compensation amount, the average value of the compensation amount and the maximum value of the compensation amount.

2. The display device according to claim 1, wherein: The compensation circuit accumulates image data in units of frames and selects the first area based on the accumulated data.

3. The display device according to claim 2, wherein: The compensation circuit controls to periodically sense a degree of degradation of the pixel in the selected first area.

4. A display device, comprising: a display panel including pixels and divided into at least one first region where degradation is sensed and at least one second region where degradation is not sensed, wherein a region where degradation is expected to be greater than degradation of other regions is selected as the at least one first region based on accumulated image data from a previous frame to a current frame, wherein each of the at least one first region and the at least one second region includes at least one entire column of pixels arranged along a vertical direction of the display panel; a source driver configured to provide a data voltage to the display panel based on image data and provide sensing data by sensing a degradation degree of pixels in at least one first region of the display panel and not sensing a degradation degree of pixels in the at least one second region of the display panel; as well as a controller configured to calculate a compensation amount for each of the pixels in the first area using the sensing data, generate compensation data for compensating for degradation of the pixels in the first area and degradation of the pixels in the second area based on the compensation amount, and correct the image data using the compensation data, wherein, when a difference between a minimum value of the compensation amount and a maximum value of the compensation amount is less than a reference value, the controller generates the compensation data for compensating for degradation of the pixels in the first area and the second area using at least one of the minimum value of the compensation amount, the average value of the compensation amount, and the maximum value of the compensation amount, Wherein, when the difference is equal to or greater than a reference value, the controller generates the compensation data for compensating for the degradation of the pixels in the first area based on the compensation amount of the gradient weight applied to the surrounding pixels by the pixel having the maximum value of the compensation amount, and generates the compensation data for compensating for the degradation of the pixels in the second area using at least one of the minimum value of the compensation amount, the average value of the compensation amount and the maximum value of the compensation amount.

5. The display device according to claim 4, wherein: The source driver includes a sensing circuit configured to provide the sensing data by sensing a degree of degradation of the pixels in the first region.

6. The display device according to claim 4, wherein: The controller accumulates image data in units of frames and selects the first area based on the accumulated data.

7. The display device according to claim 4, wherein: The controller includes a compensation circuit configured to generate the compensation data using the sensing data and correct the image data using the compensation data.

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