Display device including LED driving circuit and method of operating same

Abstract

A display device is disclosed. The display apparatus includes: a plurality of light emitting devices (LEDs) constituting a plurality of sub-pixels of a display panel; an LED driving circuit receiving an input of a PWM signal and driving a plurality of light emitting devices based on the input PWM signal; at least one memory storing gray scale information of a previous frame; and at least one processor configured to, when the gradation information of the current frame is input, generate a PWM signal based on the gradation information of the current frame and the stored gradation information of the previous frame, and provide the generated PWM signal to the LED driving circuit.

Description

Technical Field

[0001] The present disclosure relates to a display device including an LED driving circuit and an operating method thereof, and more particularly, to a display device controlling the LED driving circuit by generating a pulse width modulation (PWM) signal based on previous grayscale information and current grayscale information and an operating method thereof. Background Art

[0002] Methods for adjusting the grayscale of a light emitting device within a display panel have been used. For example, a pulse amplitude modulation (PAM) method that uses a voltage difference applied to a light emitting device to represent grayscale and / or a pulse width modulation (PWM) method that uses a time difference in applying a voltage to a light emitting device to represent grayscale have been used.

[0003] When a plurality of light emitting devices formed of a plurality of rows are driven in a PWM method, PWM data may be input to a plurality of LED driving circuits respectively corresponding to the plurality of light emitting devices, and the plurality of light emitting devices may be driven based on the input PWM data. Summary of the invention

[0004] Technical issues

[0005] Technical Solution

[0006] According to an embodiment, a display device includes: a plurality of light emitting devices forming a plurality of sub-pixels of a display panel; an LED driving circuit receiving a pulse width modulation (PWM) signal and driving the plurality of light emitting devices based on the input PWM signal; at least one memory configured to store grayscale information of a previous frame; and at least one processor configured to generate a PWM signal and provide the generated PWM signal to the LED driving circuit.

[0007] The at least one processor may be configured to generate a PWM signal based on the grayscale information of the current frame and the stored grayscale information of the previous frame, based on the grayscale information of the current frame being input.

[0008] According to an embodiment, a method for operating a display device is disclosed, the display device including a plurality of light-emitting devices forming a plurality of sub-pixels, the method including: storing grayscale information of a previous frame, generating a pulse width modulation (PWM) signal, and driving the plurality of light-emitting devices based on the PWM signal. Generating the PWM signal includes: based on the grayscale information of a current frame being input, generating the PWM signal based on the grayscale information of the current frame and the stored grayscale information of the previous frame. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The above and other aspects, features and advantages of certain embodiments of the present disclosure will become more apparent through the following description in conjunction with the accompanying drawings, in which:

[0010] Figure 1 is a block diagram illustrating functions of a display device according to one or more embodiments;

[0011] Figure 2 is a block diagram illustrating the functions of a display panel according to one or more embodiments;

[0012] Figure 3 is a diagram illustrating the functionality of a driver according to one or more embodiments;

[0013] Figure 4 is a circuit diagram showing a connection relationship between an LED driving circuit and a light emitting device included in a display panel according to one or more embodiments;

[0014] Figure 5 is an example showing a block drive according to one or more embodiments;

[0015] Figure 6 is an example illustrating the operation of a plurality of light emitting devices according to one or more embodiments;

[0016] Figure 7 is an example showing an output waveform for each grayscale output to a light emitting device according to one or more embodiments;

[0017] Figure 8 is an example showing an output waveform before compensation and an output waveform after compensation according to one or more embodiments;

[0018] Fig. 9 is an example of a lookup table according to one or more embodiments; and

[0019] Fig.10 is a flowchart illustrating an operating method of a display device according to one or more embodiments. DETAILED DESCRIPTION

[0020] When describing the embodiments, if a detailed description of a related known technology may cause unnecessary confusion, its detailed description may be omitted. In addition, redundant descriptions of the same configuration may be omitted.

[0021] The terms used in the present disclosure are used to describe one or more embodiments, but are not intended to limit the present disclosure. Unless otherwise specified, a singular expression includes a plural expression.

[0022] In the present disclosure, it should be understood that the terms "having" or "including" used herein indicate the existence of features, numbers, steps, operations, elements, components or a combination thereof, but do not exclude the existence or possibility of adding one or more other features, numbers, steps, operations, elements, components or a combination thereof.

[0023] Expressions such as “first”, “second”, etc. used herein may be used to refer to various elements regardless of order and / or importance. It should be noted that these expressions are only used to distinguish one element from another element, but do not limit the relevant elements.

[0024] Expressions such as “at least one of” when following a list of elements modify the entire list of elements and do not modify the individual elements of the list. For example, the expression “at least one of a, b, and c” or “at least one of a, b, or c” should be read to include only a, only b, only c, including a and b, including a and c, including b and c, or including all of a, b, and c.

[0025] When a certain element (for example, a first element) is expressed as being "coupled (operably or communicatively) to" or "connected to" another element (for example, a second element), it can be understood that the element is directly coupled to the other element or coupled through other elements (for example, a third element). On the other hand, when a certain element (for example, a first element) is expressed as being "directly coupled to" or "directly connected to" another element (for example, a second element), it can be understood that there is no other element (for example, a third element) between the element and the other element.

[0026] Unless otherwise specified, terms used in one or more embodiments of the present disclosure may be interpreted according to the meanings generally understood by those skilled in the art.

[0027] Various embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings.

[0028] Figure 1 is a block diagram illustrating functions of a display device according to one or more embodiments.

[0029] The display device 1000 may be a terminal device, such as but not limited to a television (TV), a monitor, a smart phone, a notebook personal computer (PC), a tablet PC, a desktop PC, etc., a wearable device (such as a smart watch, etc.), but not limited thereto, and may be a display device according to the present disclosure as long as it is a device that displays images using multiple light-emitting devices.

[0030] refer to Figure 1 , the display device 1000 may include a display panel 100 and a driver 200 .

[0031] The display panel 100 may include a plurality of light emitting devices 111-1, 111-2, 111-3, ... 112-1, 112-2, 112-3, ... forming a plurality of sub-pixels and a plurality of LED driving circuits 121, 122, 123, .... This will be referred to below. Figure 2 A detailed configuration and operation of the display panel 100 are described.

[0032] The driver 200 may input various signals to the plurality of LED driving circuits 121 , 122 , 123 , . . . included in the display panel 100 . The driver 200 may include a memory 210 and a processor 220 .

[0033] The memory 210 may store grayscale information of a previous frame. The grayscale information may be PWM pulse width information for driving a plurality of pixels included in the display panel, or may be brightness information of each pixel (or sub-pixel) included in the display panel. In the present disclosure, although it has been described that only the grayscale information of the previous frame is stored, in implementation, not only the grayscale information of the previous frame but also the grayscale information of the previous two frames may be stored.

[0034] In addition, the memory 210 may store a lookup table. The lookup table may be a table having information about the degree of compensation of the current grayscale information according to the relationship between the previous grayscale information and the current grayscale information. For example, it may be a table as follows: if the previous grayscale value is a high grayscale value, and the current grayscale value is a grayscale value lower than the high grayscale value, the compensation grayscale value includes a grayscale value lower than the current grayscale value; and if the previous grayscale value is a low grayscale value, and the current grayscale value is a high grayscale value higher than the previous grayscale value, the compensation grayscale value includes a value higher than the current grayscale value. Further, the grayscale information may be information corresponding to the brightness of the light-emitting device, and may be a pulse width (or duty cycle) corresponding to a PWM signal, or may be a brightness value of a pixel.

[0035] The memory 210 may store a plurality of lookup tables divided for each image mode, and the processor 220 to be described below may use the lookup table corresponding to the image mode. In addition, the memory 210 may store a plurality of lookup tables according to the position of the light emitting device within the block.

[0036] The memory 210 as described above may be implemented in various forms, such as but not limited to a random access memory (RAM) or a flash memory, a hard disk drive (HDD), an external memory, a memory card, etc., and is not limited to any one.

[0037] When grayscale information of the current frame is input, the processor 220 may generate a PWM signal based on grayscale information of the previous frame and the current frame stored in the memory 210. Specifically, the processor 220 may compensate grayscale information corresponding to the current frame based on the grayscale information stored in the memory 210.

[0038] For example, if the memory 210 stores pulse width information corresponding to a PWM signal and receives image data of R / G / B components, the processor 220 can check the PWM pulse width of the current frame and a specific light-emitting device, and determine whether the pulse width information of the current frame needs to be compensated by comparing the pulse width information of the corresponding light-emitting device pre-stored in the memory 210 with the pulse width information of the current frame.

[0039] In addition, based on the need for compensation, the processor 220 can compensate the pulse width of the current frame by referring to the pulse width of the previous frame. Whether compensation is needed and performing compensation as described above can be determined by using a lookup table or equation. In addition, the above determination and compensation can be performed in one step. For example, compensation can be performed without performing an operation to determine whether compensation is needed.

[0040] The following will refer to Figures 4 to 9 The determination of whether specific compensation is required and the compensation operation in processor 220 are described.

[0041] Further, the processor 220 may provide the generated PWM signal to the LED driving circuit.

[0042] Furthermore, the driver 200 may include not only the memory 210 and the processor 220 described above, but may also include a timing controller, a data driving unit, a gate driving unit, and the like.

[0043] The timing controller can generate image data signals, scan control signals, data control signals, emission control signals, etc. by receiving input signals such as an input signal (IS), a horizontal synchronization signal (Hsync), a vertical synchronization signal (Vsync), a main clock signal (MCLK), etc. from the outside, and provide them to the display panel 100, a data driving unit, a gate driving unit, etc.

[0044] Specifically, the timing controller may apply at least one of the various signals (Emi, Vsweep, Vini, VST, test / discharge) to the plurality of LED driving circuits 121, 122, 123, ... In addition, the timing controller may apply a control signal (MUX Sel R, G, B) for selecting one sub-pixel from among the R, G, B sub-pixels to the plurality of LED driving circuits 121, 122, 123, ...

[0045] As a means of generating a data signal, the data driving part (or source driver, data driver) may receive image data of R / G / B components and generate a data voltage (eg, PWM data voltage, PAM data voltage).

[0046] The processor 220 may be implemented as a data driving unit and / or as a configuration separate from the data driving unit to perform a function of directly compensating a data voltage generated from the data driving unit based on grayscale information.

[0047] For example, in order to perform the functions according to the present disclosure, the data driving part of the related art and the processor according to the present disclosure may be combined and implemented, or the processor may be implemented to perform the functions of the data driving part of the related art together with it. If implemented in the first form, the processor 220 may compensate the PWM signal generated from the data driving part through the above operation and provide the compensated PWM signal to the LED driving circuit.

[0048] If implemented in the second form, the processor 220 can receive image data of R / G / B components, etc., generate a PWM signal based on the grayscale information of the previous frame and the grayscale information corresponding to the current frame, and provide the generated PWM signal to the LED driving circuit.

[0049] The gate driving part (or gate driver) may be a device that generates various control signals such as SPWM (n) and SPAM. The gate driving part may input the generated various control signals to the LED driving circuit corresponding to a specific row (or a specific horizontal line) among a plurality of pixels on the display panel 100, but is not limited thereto.

[0050] According to one or more embodiments, the gate driving part may apply a driving voltage (VDD) to a driving voltage terminal of the LED driving circuit.

[0051] The data driving part and the gate driving part may be implemented such that all or part thereof are included in a thin film transistor (TFT) layer formed at one surface of the glass of the display panel 100 , or implemented as separate semiconductor ICs and disposed on opposite surfaces of the glass.

[0052] According to one or more embodiments, a display wall including a plurality of the above-mentioned display panels may also be realized. On the display wall, the light-emitting period of each group of LED driving circuits included in one display panel may be designed not to overlap with the light-emitting period of each group of LED driving circuits included in another display panel.

[0053] In one example, it may be assumed that the first display panel drives the light emitting devices of the first and second groups in each group, and the second display panel drives the light emitting devices of the third and fourth groups in each group.

[0054] In this case, the light emission period of the third group included in the second display panel may be started after the time point at which the light emission period of the first group included in the first display panel ends. In addition, the light emission period of the second group included in the first display panel may be started after the time point at which the light emission period of the third group included in the second display panel ends. In addition, the light emission period of the fourth group included in the second display panel may be started after the time point at which the light emission period of the second group included in the first display panel ends.

[0055] The display device 1000 according to the present disclosure as described above can compensate for the change in image brightness according to the distortion of the PWM signal generated by the RC component in the LED driving circuit for LED driving.

[0056] exist Figure 1 In the embodiment, for the convenience of description, although it has been described that the grayscale information of the current frame is compensated using the relationship between the grayscale information of the previous frame and the grayscale information of the current frame, the grayscale information of the current frame may also be used to compensate the grayscale information of the current frame when it is implemented. For example, when a plurality of light-emitting devices of a pixel are driven in sequence, that is, when the brightness value of the pixel is represented by performing a light-emitting operation in the order of an R device, a G device, and a B device, when the G device is implemented, the grayscale information of the G device may be compensated by using the grayscale information of the R device, and when the B device is implemented, the grayscale information of the B device may be compensated by using the grayscale information of the G device.

[0057] Figure 2 is a block diagram illustrating functions of a display panel according to one or more embodiments.

[0058] refer to Figure 1 According to an embodiment, the light emitting device based display panel 100 may include a plurality of light emitting devices 111-1, 111-2, 111-3, ..., 112-1, 112-2, 112-3, ... which form a plurality of sub-pixels and a plurality of LED driving circuits 121, 122, 123, ...

[0059] The plurality of LED driving circuits may be circuits for driving one or more light emitting devices, respectively. The plurality of LED driving circuits may be included in a circuit layer (eg, a thin film transistor (TFT)) formed on a substrate of the display panel. In this case, the substrate may be implemented as, for example, glass.

[0060] Each light emitting device may be an inorganic light emitting device forming one sub-pixel.

[0061] In one example, when the light emitting device is implemented as a micro LED, the light emitting device may form a sub-pixel that outputs any one of red, green, or blue light. In this case, a light emitting device corresponding to each of red, green, and blue may form one pixel. That is, one pixel may be formed by a red micro LED that outputs red light, a green micro LED that outputs green light, and a blue micro LED that outputs blue light.

[0062] The display panel 100 may be formed of a plurality of pixels, and the plurality of pixels may be arranged in a matrix form in the display panel 100. At this time, the number of pixels may be determined according to the resolution. For example, a display panel of a display device displaying 8K resolution at a ratio of 16:9 may be formed of 7680×4320 pixels, and since one pixel is formed of three LEDs in the case of an inorganic light emitting device, three 7680×4320 (7680×4320×3) LEDs may be required.

[0063] refer to Figure 2 , the plurality of light emitting devices may be divided into a plurality of groups 111, 112, ... At this time, the light emitting devices forming pixels located in the same row among the plurality of pixels arranged in a matrix form may be divided into the same group. Alternatively, the light emitting devices forming pixels positioned in a chessboard form among the plurality of pixels arranged in a matrix form may be divided into the same group.

[0064] The plurality of LED driving circuits 121 , 122 , 123 , . . . may receive a PWM data voltage according to a scanning period.

[0065] Further, the plurality of LED driving circuits 121, 122, 123, . . . may drive the plurality of light emitting devices by supplying driving current to the plurality of light emitting devices for a time corresponding to the input PWM data voltage in the light emitting period.

[0066] refer to Figure 2 , the plurality of LED driving circuits may be respectively connected to the light emitting devices included in the groups different from each other among the plurality of groups. Further, each LED driving circuit may drive the connected light emitting devices on a group basis.

[0067] Specifically, the plurality of LED driving circuits may divide and drive the plurality of groups by driving the light emitting devices included in each group during the scanning period and the light emitting period of each group.

[0068] At this time, the plurality of LED driving circuits can drive the plurality of groups in a time-division manner, that is, the light-emitting periods of the driving respective groups can be divided respectively.

[0069] The LED driving circuit 121 may be connected to the light emitting device 111-1 belonging to group 1 (111) and the light emitting device 112-1 belonging to group 2 (112), respectively. The LED driving circuit 121 may be connected to the light emitting devices belonging to group 3, group 4, etc., respectively. The LED driving circuit 121 may sequentially (time-divisionally) drive the light emitting device 111-1 and the light emitting device 112-1, respectively.

[0070] The LED driving circuit 122 may also be connected to the light emitting device 111-2 belonging to the group 1 (111) and the light emitting device 112-2 belonging to the group 2 (112), respectively. Then, the LED driving circuit 122 may divide and drive the light emitting device 111-2 and the light emitting device 112-2, respectively.

[0071] At this time, when the LED driving circuit 121 drives the light emitting device 111 - 1 included in the group 1 ( 111 ), the LED driving circuit 122 may also drive the light emitting device 111 - 2 included in the group 1 ( 111 ).

[0072] Furthermore, when the LED driving circuit 121 drives the light emitting device 112 - 1 included in the group 2 ( 112 ), the LED driving circuit 122 may also drive the light emitting device 112 - 2 included in the group 2 ( 112 ).

[0073] Figure 3 is a diagram showing a method according to an embodiment Figure 1 Schematic diagram of the functions of the drive.

[0074] refer to Figure 3 , the driver 200 may include a memory 210 and a processor 220 .

[0075] According to an embodiment, the memory 210 may store information about an input image corresponding to a previous frame. The information about the input image may be brightness information, or pulse width information corresponding to a PWM signal.

[0076] The processor 220 may generate a PWM signal by comparing an input image corresponding to a current frame with an input image corresponding to a previous frame. At this time, the processor 220 may determine a corresponding compensation method from various compensation methods (or multiple lookup tables) based on the image mode or the complexity of the input image, and perform compensation based thereon.

[0077] The processor 220 may be compensated using a calculation method or a method utilizing a lookup table. For example, in the case where the brightness variation of the panel (or display device) is linearly deformed, a compensation operation may be performed by using a calculation method. In one example, by using an equation such as (N-2)×C+(N-1)×A+(N)×B (N represents the frame number, wherein N represents the current frame, N-1 represents the previous frame, N-2 represents the frame that is 1 frame ahead of the N-1 frame, and C, A, and B represent constants (or weight values)), the pulse width or brightness value to be provided to the corresponding light-emitting device may be calculated. The constants or weight values ​​mentioned here may be calculated by experiments of the corresponding panel, and may be variably set according to the position within a block formed by the panel or a plurality of light-emitting devices or the characteristics (moving / standard / dynamic) of the image.

[0078] Alternatively, when the brightness variation includes nonlinear (eg, logarithmic or exponential) variation characteristics with respect to the PWM pulse width variation, the compensation value may be calculated by using a lookup table. Fig. 9 An example of a lookup table is described.

[0079] Figure 4 1 is a circuit diagram showing a connection relationship between an LED driving circuit and a light emitting device included in a display panel according to one or more embodiments. Specifically, Figure 4 is an example showing an LED driving circuit 121 connected to respective light emitting devices 111 - 1 and 112 - 1 forming red sub-pixels, which are respectively included in two different pixels.

[0080] refer to Figure 4 The LED driving circuit 121 can be connected to a first transistor 411, a second transistor 412, etc. The first transistor 411 is included in group 1 (111) and is connected to a light-emitting device 111-1 driven by the LED driving circuit 121. The second transistor 412 is included in group 2 (112) and is connected to a light-emitting device 112-1 driven by the LED driving circuit 121.

[0081] The LED driving circuit 121 may apply current to the first transistor 411 or the second transistor 412 according to the common control signal (Emi ( 450 )).

[0082] Specifically, during the light emission period in which the common control signal (Emi ( 450 )) is applied, the LED driving circuit 121 may apply current to the first transistor 411 or the second transistor 412 .

[0083] At this time, the first transistor 411 can be switched according to the first control signal (Emi (1) (451)), and the second transistor 412 can be switched according to the second control signal (Emi (2) (452)). The first control signal (Emi (1) (451)) can turn on the first transistor 411 during the light-emitting period 461 of the group 1 (111), so as to apply the current from the LED driving circuit 121 to the light-emitting device 111-1. In addition, the second control signal (Emi (2) (452)) can turn on the second transistor 412 during the light-emitting period 462 of the group 2 (112), so as to apply the current from the LED driving circuit 121 to the light-emitting device 112-1.

[0084] Then, the LED driving circuit 121 may provide a driving current to the light emitting device 111-1 included in the group 1 (111) through the first transistor 411 turned on according to the first control signal (Emi(1)) during the light emitting period 461 of the group 1 (111) based on the first PWM data voltage input from the scanning period of the group 1 (111).

[0085] In addition, the LED driving circuit 121 can provide current to the light emitting device 112-1 included in the group 2 (112) through the second transistor 412 turned on according to the second control signal (Emi(2)) during the light emitting period 462 of the group 2 (112) based on the second PWM data voltage input according to the scanning period of the group 2 (112).

[0086] The connection relationship between the LED driving circuit and the light emitting device as described above can be generally applied to Figure 1 or Figure 2 The plurality of light emitting devices shown in the figure can be driven on a group basis when implemented. Figure 5 The operation during block driving is described in detail.

[0087] Figure 5 is an example showing a block driver according to one or more embodiments, Figure 6 is an example illustrating operations of a plurality of light emitting devices according to one or more embodiments.

[0088] refer to Figure 5 and Figure 6 A display panel that displays an image using a plurality of light emitting devices may be configured such that the plurality of light emitting devices emit light corresponding to one pixel for one pixel. Each light emitting device forming the above-mentioned pixel may be referred to as a sub-pixel.

[0089] Since LED driving circuits corresponding to the number of light emitting devices may be required to simultaneously drive a plurality of light emitting devices in the display panel, one LED driving circuit may be controlled to sequentially emit the plurality of light emitting devices according to a scanning driving method.

[0090] With the recent increase in image resolution, the number of pixels forming an image increases, and it takes a lot of time to drive all pixels in sequence. Therefore, a plurality of light emitting devices may be divided into a plurality of rows and blocks of column units, and the operation in the above-mentioned scanning driving method may be performed on the basis of the divided blocks. The following describes the compensation operation based on the assumption that the driving is performed on a block basis, but the compensation operation may be performed even if the operation is not performed on a block basis in implementation.

[0091] refer to Figure 5 , describes the image display operation within a block unit formed by a plurality of light emitting devices, but for convenience, only the light emitting devices forming one block are shown in the figure. Therefore, when implemented, the panel may include Figure 5 Multiple blocks shown.

[0092] When a block is formed of multiple columns and multiple rows, operations can be performed sequentially starting from the first column according to the VST signal. When a common control signal (Emi) is input for each column, a PWM signal corresponding to a grayscale value in a corresponding light emitting device can be input for each light emitting device to which the corresponding common control signal is input.

[0093] As described above, since a plurality of light emitting devices simultaneously perform operations when a plurality of LED devices are block driven, even if the same low gray value is input, the waveform type input to each light emitting device in actual operation may be different between the first light emitting device of the block drive and the light emitting device located in the last row. Due to the slow conversion of RC, the waveform of the last row signal may be a square wave instead of a square wave compared to the waveform corresponding to the first row signal of the first block. This will be referred to below. Figure 7 Describe the above types.

[0094] Figure 7 is an example showing an output waveform for each gray level output to a light emitting device.

[0095] Figure 7 Examples of waveforms output to the light emitting device for a plurality of grayscale values ​​and for each time axis are shown.

[0096] refer to Figure 7, even if a square wave is generated and input to the light-emitting circuit, it can be verified that the waveform input to the light-emitting device as shown in the figure has a significantly distorted shape rather than a square wave. Specifically, the distortion of the above waveform may be affected by the time axis (N-1 frame or subframe) and may also be affected by the space axis (the waveform of the previous color when RGB is continuously input).

[0097] As described above, if the grayscale value of the previous frame (or the grayscale value of another sub-pixel forming the same pixel in the current frame) is a high grayscale value or a low grayscale value, the grayscale value of the subsequent frame may include a higher or lower brightness than the grayscale value of the corresponding pixel actually input. Figure 8 Describe these two situations.

[0098] Figure 8 is an example showing an output waveform before compensation and an output waveform after compensation according to one or more embodiments.

[0099] A distortion phenomenon when a previous frame includes a high gray value and a subsequent frame includes a low gray value, and an operation of the present disclosure to solve the above problem will be described.

[0100] Figure 8 The second pulse and the third pulse of the first waveform 810 are shown. The straight line of the waveform shown may be a PWM signal generated by a driving circuit, and the dotted line may be a signal form input to an actual lighting circuit affected by RC or the like.

[0101] If the pulse of the previous frame includes a high grayscale value, the light emitting device can perform a turn-on operation faster than typical cases because the PWM signal rises before turning to 0. That is, the light emitting device can be driven in a turn-on state longer than the duty time corresponding to the original grayscale value.

[0102] Therefore, based on the previous frame including high grayscale values ​​and the subsequent frame including low grayscale values, the duty cycle value can be compensated to include a duty cycle value smaller than the duty cycle value corresponding to the current frame (821). The degree of duty cycle compensated at this time can be based on actual measurement values ​​or experimental values.

[0103] A distortion phenomenon when a previous frame includes a low gray value and a subsequent frame includes a high gray value, and an operation of the present disclosure to solve the above problem will be described.

[0104] Specifically, Figure 8 A third pulse and a fourth pulse of the first waveform 810 are shown.

[0105] If the pulse of the previous frame includes a low gray value, the light emitting device can be turned on more slowly than in the typical case where the PWM signal fully converges to a value of 0. That is, the light emitting device can be driven in an on state shorter than the duty time corresponding to the original gray value.

[0106] Therefore, the present disclosure may compensate the duty cycle value based on the previous frame including a low grayscale value and the subsequent frame including a high grayscale value to include a duty cycle value longer than the duty cycle value corresponding to the current frame (823). The compensated duty cycle at this time may be based on an actual measured value or an experimental value.

[0107] Fig. 9 is an example showing a lookup table in accordance with one or more embodiments.

[0108] refer to Fig. 9 The lookup table may store the PWM information of the previous frame and the current frame respectively. For example, when the brightness value of the previous frame is 128 and the current brightness value is 128, no separate compensation may be performed.

[0109] Alternatively, when the brightness value of the previous frame is 128 and the brightness value of the current frame is 512, compensation may be performed to include a pulse width wider than the original period.

[0110] Fig. 9 The numbers of the lookup tables shown may include numerical values ​​that describe the operation of the lookup tables, and in actual implementation may be divided more than the above ranges, and other values ​​different from the corresponding values ​​may be used.

[0111] Fig.10 is a flowchart illustrating an operating method of a display device according to one or more embodiments.

[0112] refer to Fig.10 , grayscale information of a previous frame may be stored ( S1010 ).

[0113] A PWM signal may be generated (S1020). If grayscale information of a current frame is input, a PWM signal may be generated based on the grayscale information of the current frame and the stored grayscale information of a previous frame.

[0114] For example, based on the grayscale information being pulse width information corresponding to the PWM signal, when the pulse width information of the current frame is input, the input pulse width information of the current frame can be compensated based on the pulse width information of the stored previous frame. In a more specific example, when a lookup table including a plurality of compensated pulse width values ​​corresponding to a plurality of previous pulse width values ​​and a plurality of current pulse width values ​​is used, the pulse width information can be compensated by checking the compensated pulse width corresponding to the pulse width information of the current frame and the pulse width information of the stored previous frame. Then, a PWM signal can be generated based on the compensated pulse width information.

[0115] If the grayscale information is the brightness information of the sub-pixel, the input brightness information of the current frame can be compensated based on the brightness information of the previous frame stored. Then, the PWM signal can be generated based on the compensated brightness information. In a more specific example, when a lookup table including a plurality of compensated brightness values ​​corresponding to a plurality of previous brightness values ​​and a plurality of current brightness values ​​is used, the brightness information can be compensated by checking the compensated brightness values ​​corresponding to the brightness information of the current frame and the stored brightness information of the previous frame.

[0116] The plurality of light emitting devices may be driven based on the PWM signal ( S1030 ).

[0117] Can be Figure 1 The display device is executed by Fig.10 Describes how to operate.

[0118] The various elements according to the various embodiments described above may be formed by a single entity or multiple entities, and in various embodiments, some of the sub-elements described above may be omitted, or other sub-elements may also be included. Alternatively or additionally, some elements may be integrated into one entity to perform the same or similar functions performed by the respective elements before integration.

[0119] According to the various embodiments described above, computer instructions for performing processing operations in a device may be stored in a non-transitory computer-readable medium. When executed by a processor of a specific device, the computer instructions stored in the non-transitory computer-readable medium may cause the specific device to perform the processing operations of the device according to the various embodiments described above. A non-transitory computer-readable medium may refer to a medium that stores data semi-permanently rather than for a very short period of time, such as a register, a cache, a memory, etc., and can be read by a device. Examples of non-transitory computer-readable media may include, for example, but not limited to, a compact disc (CD), a digital versatile disc (DVD), a hard disk, a Blu-ray disc, a USB, a memory card, a ROM, etc.

[0120] According to the various embodiments described above, operations performed by a module, program or other element may be performed sequentially, in parallel, repeatedly or heuristically, or at least some operations may be performed in a different order, omitted, or different operations may be added.

[0121] Although one or more embodiments have been illustrated and described with reference to various examples, it should be understood that the various exemplary embodiments are intended to be illustrative rather than restrictive. It should be understood that various changes in form and details may be made by those skilled in the art without departing from the true spirit and full scope of the present disclosure, including the appended claims and their equivalents.

Claims

1. A display device, comprising: A plurality of light emitting devices LED, forming a plurality of sub-pixels of a display panel; LED drive circuit; at least one memory configured to store previous grayscale information of a previous frame; as well as At least one processor configured to: Based on the grayscale information of the current frame received, a pulse width modulation (PWM) signal is generated based on the grayscale information of the current frame and the stored previous grayscale information of the previous frame; as well as providing the generated PWM signal to the LED driving circuit, The LED driving circuit is configured to receive the PWM signal and drive the plurality of LEDs based on the received PWM signal.

2. The display device according to claim 1, wherein: The grayscale information is pulse width information corresponding to the PWM signal, and Wherein, the at least one processor is further configured to: Based on the received pulse width information of the current frame, compensating the received pulse width information of the current frame based on the stored pulse width information of the previous frame; and The PWM signal is generated based on the compensated pulse width information.

3. The display device according to claim 1, wherein: The grayscale information is the brightness information of the sub-pixel, and Wherein, the at least one processor is further configured to: Based on the received brightness information of the current frame, compensating the received brightness information of the current frame based on the stored brightness information of the previous frame; and The PWM signal is generated based on the compensated brightness information.

4. The display device according to claim 1, wherein: The at least one processor is further configured to: accessing a lookup table including a plurality of compensated grayscale values ​​corresponding to a plurality of previous grayscale values ​​and a plurality of current grayscale values; and A compensated grayscale value corresponding to the grayscale information of the current frame and the stored grayscale information of the previous frame is identified, and the PWM signal is generated based on the identified grayscale value.

5. The display device according to claim 4, wherein: The at least one memory is further configured to store a plurality of lookup tables for each image mode, and Wherein, the at least one processor is further configured to obtain the compensated grayscale value using a lookup table corresponding to the current image mode.

6. The display device according to claim 4, wherein: The lookup table is a table in which the compensation gray value includes a low compensation gray value lower than the current gray value based on the previous gray value being a high gray value and the lower current gray value being a low gray value lower than the high gray value.

7. The display device according to claim 4, wherein: The lookup table is a table in which the compensation gray value includes a high compensation gray value higher than the current gray value based on the previous gray value being a low gray value and the higher current gray value being a high gray value higher than the low gray value.

8. The display device according to claim 1, wherein: The at least one processor is further configured to: Obtaining a compensated grayscale value by providing grayscale information of the current frame and stored grayscale information of the previous frame to a preset equation, wherein the preset equation uses a previous grayscale value and a current grayscale value as variables; and The PWM signal is generated based on the compensated grayscale value.

9. A method for operating a display device, the display device comprising a plurality of light emitting devices LED forming a plurality of sub-pixels, the method comprising: Storing previous grayscale information of previous frames; Based on the grayscale information of the current frame received, a pulse width modulation (PWM) signal is generated based on the grayscale information of the current frame and the stored previous grayscale information of the previous frame; as well as The plurality of LEDs are driven based on the PWM signal.

10. The operating method according to claim 9, wherein: The grayscale information is pulse width information corresponding to the PWM signal, and Wherein, generating the PWM signal includes: based on the received pulse width information of the current frame, compensating the received pulse width information of the current frame based on the stored pulse width information of the previous frame, and generating the PWM signal based on the compensated pulse width information.

11. The operating method according to claim 9, wherein: The grayscale information is the brightness information of the sub-pixel, and The generating of the PWM signal comprises: based on the received brightness information of the current frame, compensating the received brightness information of the current frame based on the stored brightness information of the previous frame, and generating the PWM signal based on the compensated brightness information.

12. The operating method according to claim 9, wherein: Generating the PWM signal includes: accessing a lookup table, the lookup table including a plurality of compensated grayscale values ​​corresponding to a plurality of previous grayscale values ​​and a plurality of current grayscale values; identifying the compensated grayscale values ​​corresponding to the grayscale information of the current frame and the stored grayscale information of the previous frame; and generating the PWM signal based on the identified grayscale values.

13. The operating method according to claim 12, wherein: Generating the PWM signal includes accessing a lookup table corresponding to a current image mode from among a plurality of lookup tables for each image mode and identifying the compensated grayscale value.

14. The operating method according to claim 12, wherein: The lookup table is a table in which the compensation gray value includes a low compensation gray value lower than the current gray value based on the previous gray value being a high gray value and the lower current gray value being a low gray value lower than the high gray value.

15. The operating method according to claim 12, wherein: The lookup table is a table in which the compensation gray value includes a high compensation gray value higher than the current gray value based on the previous gray value being a low gray value and the higher current gray value being a high gray value higher than the low gray value.

Images