Display device and display method thereof

Abstract

A display device and a display method thereof are provided. The display device includes a display panel, a data driver, and a timing controller. The data driver may apply a first data voltage set and subsequently a second data voltage set to the display panel during screen saver operation of the display device. The first data voltage set may cause the display panel to display a first illumination area. The second data voltage set may cause the display panel to display a second illumination area. The timing controller may supply image data for the second data voltage set to the data driver so that the second illumination area has a predetermined brightness level. The timing controller may determine a value for controlling the predetermined brightness level based on a distance between a position of the first illumination area and a position of the second illumination area.

Description

[0001] This application claims priority from Korean Patent Application No. 10-2020-0019813 filed on February 18, 2020, in the Korean Intellectual Property Office, which is incorporated herein by reference. Technical Field

[0002] TECHNICAL FIELD The present invention relates to a display device and a method of operating the display device. Background Art

[0003] Modern display devices include liquid crystal displays and organic light emitting diode displays.

[0004] The liquid crystal display generally includes a backlight unit and displays an image by partially and selectively transmitting light emitted from the backlight unit.

[0005] Organic light emitting diode displays are self-luminous and do not require a backlight unit.

[0006] Display devices may be included in electronic devices such as mobile phones, televisions, and monitors. Generally, it is desirable to minimize the power consumption of display devices.

[0007] The above information disclosed in this Background section is for enhancement of understanding of the background of the described technology. This Background section may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art. Summary of the Invention

[0008] Embodiments may relate to a display device with low power consumption.Embodiments may relate to an organic light emitting diode display with a long lifespan and delayed onset of aging.

[0009] Embodiments may relate to a display device in which brightness changes during screen saver operation are not noticeable.

[0010] An embodiment may relate to a display device comprising the following elements: a display panel configured to include a plurality of pixels; a data driver configured to apply data voltages to the pixels; and a timing controller configured to supply image data to the data driver, wherein, when a display area changes from a first display area to a second display area during a screen saver operation, the timing controller displays a brightness of the second display area differently according to a distance between the first display area and the second display area.

[0011] When the distance between the first display area and the second display area is small, the brightness of the second display area can be displayed as a first brightness with a low brightness value, and when the distance between the first display area and the second display area is large, the brightness of the second display area can be displayed as a second brightness with a high brightness value.

[0012] When the distance between the first display area and the second display area is small, it can be less than the first reference distance; when the distance between the first display area and the second display area is large, it can be greater than the second reference distance; and when the distance between the first display area and the second display area is between the first reference distance and the second reference distance, the second display area can be displayed as an intermediate brightness between the first brightness and the second brightness.

[0013] The display panel may be divided into a plurality of blocks arranged in a matrix form, and the distance may be expressed on a block basis.

[0014] When the same screen is displayed for a predetermined time or longer, the screen saver operation may gradually reduce the brightness of the display area to display the minimum brightness.

[0015] The timing controller may include: a first frame memory and a second frame memory; a first total load summing unit connected to the first frame memory; a second total load summing unit connected to the second frame memory; a total load comparison unit connected to the first total load summing unit and the second total load summing unit; a load comparison unit for each block connected to the first frame memory and the second frame memory; and a gain determination unit configured to receive outputs of the total load comparison unit and the load comparison unit for each block to determine a gain value.

[0016] The timing controller may further include a counter, and the counter may transmit a final count value to the gain determination unit.

[0017] The counter may output an enable signal to allow the load comparison unit and the gain determination unit for each block to operate.

[0018] The terminal count value may be compared to a counter threshold, and when it is greater than the counter threshold, an enable signal may be output.

[0019] The total load comparison unit may compare the threshold of the total load value with the difference between the total load value of the first total load summing unit and the total load value of the second total load summing unit, and when the difference is less than the threshold of the total load value, may not output an enable signal to the gain determination unit.

[0020] The first frame memory and the second frame memory may respectively include a plurality of frame memories for each of the first block and the second block, and the load comparison unit for each block may compare the difference between a load threshold for each block and a value stored in each of the first frame memory and the second frame memory, and when the difference for each block is less than the load threshold, the load value for each block may be processed as unchanged.

[0021] The gain determination unit may receive block coordinate information from the load comparison unit for each block to calculate a final gain.

[0022] The gain determination unit may include: a block coordinate information receiving unit configured to receive block coordinate information from a load comparison unit for each block; a first coordinate analysis unit and a second coordinate analysis unit configured to identify an x-axis distance and a y-axis distance, respectively, by using the block coordinate information; a first gain calculation unit configured to obtain an x-axis gain value based on the x-axis distance checked by the first coordinate analysis unit; a second gain calculation unit configured to obtain a gain value for the y-axis distance based on the y-axis distance checked by the second coordinate analysis unit; a synthesis unit configured to synthesize the x-axis gain value from the first gain calculation unit and the y-axis gain value from the second gain calculation unit to generate a gain value according to the total distance; and a final gain calculation unit configured to calculate a final gain value based on the gain value depending on the total distance.

[0023] The final gain calculation unit may receive a final count value from the counter to determine the final gain value based on the final count value.

[0024] Embodiments may relate to a display method for a display device. The display method may include the following steps: a first step of comparing total load values ​​of a previous frame and a current frame to check whether there is a change; a second step of comparing the load value of each block of the previous frame and the current frame to check whether there is a change; a third step of operating a screen saver when there is no change in the first step and the second step; and a fourth step of compensating display brightness based on the distance between blocks with the change when there is no change in the first step but there is a change in the second step.

[0025] Compensating for display brightness may include: analyzing position information between blocks with changes to identify distances; and compensating for display brightness based on the distance, and the compensation for display brightness may include: displaying a first brightness with low brightness when the distance is small, and displaying a second brightness with high brightness when the distance is large.

[0026] When the result of comparing the total load value is less than the threshold value of the total load value, a first step may be performed to see that there is no change.

[0027] When the result of comparing the load value of each block is less than the threshold value of the load value of each block, a second step may be performed to see that there is no change.

[0028] When the third step is performed for a predetermined time or longer, the fourth step may be performed.

[0029] When the same screen is displayed for a certain period of time or longer, the screen saver of the third step can display the minimum brightness by gradually reducing the display brightness.

[0030] Embodiments may relate to a display device. The display device may include a display panel, a data driver, and a timing controller. The data driver may be electrically connected to the display panel and may apply a first data voltage set and subsequently a second data voltage set to the display panel during screen saver operation of the display device. The first data voltage set may cause the display panel to display a first illuminated area adjacent to a first non-illuminated area. The second data voltage set may cause the display panel to display a second illuminated area adjacent to a second non-illuminated area. The timing controller may be electrically connected to the data driver and may supply image data to the data driver for the second data voltage set so that the second illuminated area has a predetermined brightness level. The timing controller may determine a brightness-related value for controlling the predetermined brightness level based on a distance-related value, the distance-related value being dependent on a distance between a position of the first illuminated area and a position of the second illuminated area.

[0031] When the distance-related value is the first value, the timing controller may determine the brightness-related value as the first value. When the distance-related value is the second value greater than the first value, the timing controller may determine the brightness-related value as the second value greater than the first value.

[0032] The first value may be smaller than a first reference value. The second value may be larger than a second reference value. When the distance-related value is larger than the first reference value and smaller than the second reference value, the timing controller may determine the brightness-related value to be larger than the first value and smaller than the second value.

[0033] The display panel may be divided into blocks arranged in a matrix form. The distance-related value may be the number of one or more of the blocks.

[0034] When the first illumination area has been illuminated for a predetermined time or longer, the timing controller may gradually reduce the brightness of the first illumination area to a predetermined brightness level.

[0035] The display panel may be divided into a plurality of blocks. The timing controller may include the following elements: a first frame memory; a second frame memory; a first total load summing unit connected to the first frame memory; a second total load summing unit connected to the second frame memory; a total load comparing unit connected to each of the first total load summing unit and the second total load summing unit; a block load comparing unit connected to each of the first frame memory and the second frame memory; and a gain determining unit configured to receive outputs of the total load comparing unit and the block load comparing unit to determine a brightness-related value.

[0036] The timing controller may further include a counter configured to transmit the count value to the gain determination unit.

[0037] The counter may output an enable signal to activate each of the block load comparison unit and the gain determination unit.

[0038] The counter may compare a count value with a counter threshold value, and when the count value is greater than the counter threshold value, the counter may output an enable signal.

[0039] The total load comparison unit may compare the threshold with the difference between the total load value of the first total load summing unit and the total load value of the second total load summing unit. When the difference is less than the threshold, the total load comparison unit may not output the enable signal to the gain determination unit.

[0040] The first frame memory may store first image data associated with a previous frame for all blocks. The second frame memory may store second image data associated with a current frame for all blocks. The block load comparison unit may compare, for each block, a load threshold value with a difference between values ​​stored in the first frame memory and the second frame memory. When the difference associated with a block is less than the load threshold value, the block load comparison unit may deem the load value of the block unchanged.

[0041] The gain determination unit may receive block coordinate information from the block load comparison unit to calculate the brightness-related value. The block coordinate information may be related to the position of the second illumination area.

[0042] The gain determination unit may include the following elements: a block coordinate information receiving unit configured to receive block coordinate information from the block load comparison unit; a first coordinate analysis unit and a second coordinate analysis unit configured to use the block coordinate information to respectively identify x-axis distance information and y-axis distance information; a first gain calculation unit configured to obtain an x-axis gain value based on the x-axis distance information; a second gain calculation unit configured to obtain a y-axis gain value based on the y-axis distance information; a synthesis unit configured to synthesize the x-axis gain value and the y-axis gain value to generate a synthesized gain value; and a gain calculation unit configured to calculate a brightness-related value based on the synthesized gain value.

[0043] The gain calculation unit receives the count value from the counter to determine a brightness-related value based on the count value.

[0044] Embodiments may relate to a display method for a display device, the display device including a display panel. The display method may include the following steps: a first step of comparing a total load value of a previous frame with a total load value of a current frame to check a first condition related to whether a total load change exceeds a total load change threshold; a second step of comparing the load value of the previous frame with the load value of the current frame for each block to check a second condition related to whether a block load change exceeds a block load change threshold; a third step of performing a screen saver operation when both the first and second conditions are false; and a fourth step of adjusting the brightness of a second illuminated area on the display panel based on a distance between a position of the second illuminated area and a position of the first illuminated area on the display panel when the first condition is false but the second condition is true. The first illuminated area may be adjacent to a first non-illuminated area on the display panel. The second illuminated area may be adjacent to a second non-illuminated area on the display panel.

[0045] The fourth step may also include the following steps: when the distance is represented by a first numerical value, setting the brightness of the second illumination area to a first brightness level; and when the distance is represented by a second numerical value greater than the first numerical value, setting the brightness of the second illumination area to a second brightness level higher than the first brightness level.

[0046] The total load change threshold may be greater than zero.

[0047] The block load change threshold may be greater than zero.

[0048] When the third step has been performed for a predetermined time or longer, the fourth step may be performed.

[0049] The third step may further include gradually reducing the brightness of the first illumination area to a predetermined brightness level when the first illumination area has been illuminated for a predetermined length of time or longer.

[0050] According to an embodiment, when a screen saver operation is executed and the same area of ​​the display device has been illuminated for a predetermined period of time or longer, the display device can reduce power consumption by gradually lowering the display brightness. This power consumption reduction is more significant as the display device becomes larger. In an organic light-emitting diode display, the lifespan of the organic light-emitting diode can be extended and / or aging can be slowed or delayed.

[0051] In an embodiment, when the illumination area changes and / or moves during screen saver operation, the brightness of the illumination area is adjusted based on the distance moved so that the user does not visually recognize the difference in brightness and does not unnecessarily mistakenly believe that the display device is defective. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 A schematic diagram showing a display device according to an embodiment is shown.

[0053] Figure 2 A flowchart illustrating a driving method (ie, an operating method) of a display device according to an embodiment is shown.

[0054] Figure 3 and Figure 4 Shown are changes depending on the screen saver operation in the display device according to the embodiment.

[0055] Figure 5 and Figure 6 Shown are a display area change (or illumination area change) and a brightness change in a screen saver operation in a display device according to a comparative example.

[0056] Figure 7 、 Figure 8 、 Figure 9 and Figure 10 Shown are a display area change (or illumination area change) and a brightness change in a screen saver operation in a display device according to an embodiment.

[0057] Figure 11 A block diagram illustrating a timing controller of a display device according to an embodiment is shown.

[0058] Figure 12 A block diagram of a gain determining unit in a timing controller of a display device according to an embodiment is shown. DETAILED DESCRIPTION

[0059] The exemplary embodiments are described with reference to the accompanying drawings. The described embodiments can be modified in various ways.

[0060] In the description, like reference numerals may denote like elements.

[0061] Although the terms "first", "second" etc. can be used to describe various elements, these elements should not be limited by these terms. These terms can be used to distinguish an element from another element. Without departing from the teaching of one or more embodiments, the first element can be named as the second element. Describing an element as a "first" element may not require or imply the existence of a second element or other elements. The terms "first", "second" etc. can be used to distinguish different classes or groups of elements. For simplicity, the terms "first", "second" etc. can represent "first type (or first group)", "second type (or second group)" etc. respectively.

[0062] In the drawings, dimensions may be exaggerated for clarity.

[0063] When a first element is referred to as being "on" a second element, the first element may be directly on the second element, or one or more intervening elements may be present between the first and second elements. When a first element is referred to as being "directly on" a second element, no intervening elements (other than ambient elements such as air) may be intended or required between the first and second elements. The terms "on" or "above" may refer to being positioned above or below an object portion, and do not necessarily refer to being positioned on the upper side of the object portion based on the direction of gravity.

[0064] Unless explicitly described to the contrary, the word "comprise" and its variations may imply the inclusion of stated elements, but may not require the exclusion of any other elements. The term "connect" may refer to "electrically connected." The term "drive" may refer to "operate" or "control."

[0065] Figure 1 A schematic diagram showing a display device according to an embodiment is shown.

[0066] The display device may include a display panel 100 ; flexible printed circuit boards 110 , 130 , and 150 ; printed circuit boards 120 and 140 ; ​​a data driver 115 ; and a timing controller 1000 .

[0067] The display panel 100 may include a plurality of pixels. The display panel 100 may be a liquid crystal display panel (including liquid crystals) or a light emitting display panel (including light emitting elements). The size of the display panel 100 may depend on the embodiment.

[0068] The pixels included in the display panel 100 are controlled according to various control signals including scan signals and data voltages. A power supply voltage having a constant voltage may also be applied to the pixels.

[0069] The display panel 100 may be a liquid crystal display panel. Data voltages and scan signals are applied to pixels. The data voltages applied to the pixels and the common voltage generate an electric field, which controls the orientation of liquid crystal molecules in the pixels, thereby controlling the transmission of light supplied from the light unit.

[0070] The display panel 100 may be a light-emitting display panel, such as an organic light-emitting display panel including an organic emission layer. In an organic light-emitting display panel, each pixel may receive a data voltage, a scan signal, a drive voltage (which is a power supply voltage), and a drive low voltage. In addition, an emission signal may be applied to each pixel. In the pixels of the organic light-emitting display panel, an output current of a drive transistor is determined based on the data voltage, and the output current flows through an organic light-emitting diode to emit light. The brightness of the light emitted by the organic light-emitting diode depends on the amount of current flowing through the organic light-emitting diode.

[0071] Although Figure 1Although not shown in the figure, the display panel 100 includes a scan driver for generating a scan signal. The scan driver may be mounted on a portion of the display panel 100. The scan driver may be formed in a process of forming pixels.

[0072] A driver that supplies an emission signal may also be formed in a process of forming pixels and may be included in the display panel 100 .

[0073] In an embodiment, the data driver 115 for applying a data voltage is disposed on the first flexible printed circuit board 110 , and the timing controller 1000 is formed on the second printed circuit board 140 .

[0074] The timing controller 1000 generates image data and control signals based on an image signal input from an external device. The data driver 115 receives the image data from the timing controller 1000 and changes the image data into a data voltage set to be applied to pixels.

[0075] The image data and data control signals output from the timing controller 1000 are transmitted to the data driver 115 on the first flexible printed circuit board 110 through the second printed circuit board 140, the second flexible printed circuit board 130, and the first printed circuit board 120. The scan control signals output from the timing controller 1000 are transmitted to the scan driver on the display panel 100 through the second printed circuit board 140, the second flexible printed circuit board 130, the first printed circuit board 120, and the first flexible printed circuit board 110.

[0076] Reference Figure 1 , the four first printed circuit boards 120 are arranged in two pairs. The two first printed circuit boards 120 constituting a pair are electrically connected to each other via the third flexible printed circuit board 150. When a signal output from the timing controller 1000 is first applied to a first printed circuit board 120 via the second printed circuit board 140 and the second flexible printed circuit board 130, it is transmitted to the other first printed circuit board 120 via the third flexible printed circuit board 150.

[0077] Reference Figure 1 , a total of 16 first flexible printed circuit boards 110 are included, and a total of 16 data drivers 115 are included. The data drivers 115 may be attached to the first printed circuit board 120 as IC chips.

[0078] The timing controller 1000 may be attached to the second printed circuit board 140 in the form of an IC chip.

[0079] The second printed circuit board 140 may further include a power voltage generator for generating a power voltage.

[0080] The display panel 100 , the flexible printed circuit boards 110 , 130 , and 150 , and the printed circuit boards 120 and 140 are attached through an anisotropic conductive film (ACF) and are electrically connected to each other.

[0081] According to an embodiment, the display device may include only one flexible printed circuit board and one printed circuit board (PCB). In this case, the timing controller 1000 may be provided on the PCB, and the data driver 115 may be provided on the flexible printed circuit board or attached to the display panel 100.

[0082] Reference Figure 1 , the display panel 100 includes a plurality of blocks. The display panel 100 is not physically divided into a plurality of blocks, but is conceptually divided when the data driver 115 and the timing controller 1000 drive the pixels. One column of blocks corresponds to one data driver 115, so that the display panel 100 has a total of 16 blocks in the row direction. Figure 1 , the number of blocks in the row direction is equal to each of the number of data drivers 115 and the number of first flexible printed circuit boards 110 .

[0083] Since the number of blocks in each column is 8, the display panel 100 includes a total of 128 blocks. When the size of the display panel 100 is 55 inches or larger, the display panel 100 can be divided into 128 blocks. Although the number of blocks can be configured according to the embodiment, the following description will be based on an example in which the display panel is divided into 128 blocks.

[0084] Figure 2 A flowchart illustrating a driving method of a display device according to an embodiment is shown.

[0085] Figure 2 The driving method shown in is related to a screen saver operation when a user does not provide an input to a display device for a predetermined time or longer.

[0086] Figure 2 The operations shown in FIG. 1 may be performed by the timing controller 1000 .

[0087] First, the timing controller 1000 may determine whether there is a change by comparing total load values ​​of the previous frame and the current frame based on the image signal of each frame provided to the timing controller 1000 (S10). The total load value of the image signal of one frame may be a simple sum of image data to be supplied to pixels.

[0088] When there is a change in the total load value between two adjacent frames, the displayed image may be a video, and the video signal input to the timing controller 1000 is processed to transmit the video data to the data driver 115 to display the video (S15). In step S15, the display panel 100 displays the image regardless of the operation of the screen saver.

[0089] In step S10, the difference between the total load values ​​can be compared with a threshold value (greater than zero). When the difference is less than or equal to the threshold value, the timing controller 1000 can ignore the difference / change as if there is no change. This is to ensure that the screen saver operates normally when applicable.

[0090] If the timing controller 1000 determines (in step S10) that the total load has not changed or the total load change is negligible, the timing controller 1000 further determines whether there is a change by comparing the load values ​​of each block in the previous frame and the current frame (S20). This is to check whether the image displayed at each block has changed.

[0091] In step S20, the load value change of each block may be compared with a threshold value, which may be less than or equal to the threshold value in step S10 and greater than 0. When the load value change of each block is less than or equal to the threshold value in step S20, the timing controller 1000 may ignore the load value change as if there is no change.

[0092] When the total load value does not change (or the total load value change is negligible) in step S10, and when the load value of each block does not change (or the load value change is negligible) in step S20, the screen saver may be operated (S25).

[0093] When the load values ​​(total load value and load value for each block) in steps S10 and S20 remain unchanged for a certain time period or longer, the screen saver operation may be started. The screen saver operation may be started only when the display device does not receive user input for a predetermined time period or longer. This time period may be counted by a counter.

[0094] Specifically, the load value of each block is compared to check whether it has changed by comparing the load value of each block in the current frame (Nth frame) and the previous frame (N-1th frame) (S20). Since the display panel has 128 blocks, the comparison is performed for each of the 128 blocks, and the load value of each block can be a simple sum of the image data to be applied to the pixels belonging to the block.

[0095] When all 128 blocks have the same load value in the previous frame and the next frame, the display panel can display a still image. When the still image continues for a certain period of time, the screen saver is operated to protect the display device (S25). Figure 3 and Figure 4 The operation of the screen saver in step S25 will be described.

[0096] When the total load value of a frame remains unchanged but the load values ​​of one or more blocks change, the change may be caused by a change in the image displayed for the screen saver, and step S30 may be performed.

[0097] In step S30, the timing controller 1000 may identify the changed blocks and may determine position information between the changed blocks to check the distance. Here, the distance value (distance-related numerical value) may be a value indicating how many blocks are set between two blocks instead of the length.

[0098] In step S40, the timing controller 1000 may determine a gain value based on the distance. For example, when the distance between blocks with varying load values ​​is short, the timing controller 1000 may determine a low gain value. When the distance between blocks with varying load values ​​is long, the timing controller 1000 may determine a high gain value. This is to prevent the user from easily detecting changes in brightness, as changes in brightness may be noticeable when the distance is short, and may be less noticeable when the distance is long.

[0099] The determined gain value may be multiplied by the image data, and accordingly, a data voltage group is provided to the pixels of the display panel 100 by the data driver 115 to display a compensated image ( S50 ).

[0100] Here, the brightness corresponding to the highest gain value may be substantially equivalent to the brightness corresponding to the input image data.

[0101] Reference Figures 7 to 10 Step S30 , step S40 , and step S50 are further described.

[0102] In the embodiment, the screen saver is turned on only when the operation (S25) of the screen saver is performed for a certain period of time or longer (see Figure 3 At t2 in step S30, step S30 may be performed to analyze the position information between the blocks. Compensating for the screen saver operation through steps S30, S40, and S50 is performed to eliminate the problem of the user recognizing the brightness change due to the rapid increase in brightness value during the screen saver operation; therefore, when there is not much difference in display brightness shortly after the screen saver operation has been executed, compensation may not be required.

[0103] Reference Figure 3 and Figure 4describe Figure 2 The operation of step S25.

[0104] Figure 3 and Figure 4 Shown are changes depending on the screen saver operation in the display device according to the embodiment.

[0105] like Figure 3 As shown in , when the total load value of consecutive frames and the load value of each block are substantially unchanged for a continuous predetermined time or longer, a screen saver operation for (gradually) reducing brightness can be performed.

[0106] exist Figure 3 In the graph, the x-axis represents time and the y-axis represents the gain value (Gain).

[0107] First, while the total load value and the load value for each block remain substantially constant for a predetermined time (t1) (period ①), the display brightness decreases during period ②, starting from the start of the display screen saver (DSS) operation, and the gain value decreases linearly. The gain value continues to decrease until it reaches a predetermined minimum gain value; starting from the DSS minimum gain hold time, the minimum brightness is continuously displayed during period ③.

[0108] Although the time when period ③ starts can be predetermined (corresponding to the minimum gain start time at the end of t2), according to embodiments, period ③ can start at a different time. For example, period ③ can start when the gain value decreases linearly to reach a predetermined minimum value. Even in this case, the average time of the start of period ③ can be used to set the minimum gain start time to guide Figure 2 The time point at which step S30 may begin.

[0109] The screen saver operation is used to reduce the display brightness to reduce power consumption, and the power consumption reduction is more effective as the size of the display device increases. In an embodiment, in an organic light emitting diode display, the life of the organic light emitting diode can be extended and / or the aging phenomenon can be delayed.

[0110] The screen saver operation is performed through the above-mentioned periods ①, ② and ③, and then, at the DSS reset time, when the user uses the display device again (i.e., the user provides input to the display device again), the display brightness can be increased to normal brightness to perform the display operation in period ④, which can be after the screen saver operation.

[0111] Figure 4 The illumination area in the display panel for each of the period ①, the period ②, the period ③, and the period ④ is shown.

[0112] In screen saver operation, the display device may show the display area (ie, illuminated area) at different positions.

[0113] Figure 5 and Figure 6 Shown are a display area (or illumination area) change and a brightness change in a screen saver operation in a display device according to a comparative example.

[0114] exist Figure 5 In the screen saver, an illuminated area (adjacent to or surrounded by a non-illuminated area) changes / moves from point A (or point A, an area including one or more blocks or block parts) to point B (or point B, an area including one or more blocks or block parts). Figure 6 The brightness change at point A and the brightness change at point B are shown.

[0115] Reference Figure 5 and Figure 6 , white (500 nits) is displayed at point A for period ①', the brightness is reduced by period ②' in the screen saver operation, and when white (500 nits) is displayed at point B, black (0 nit) is displayed at point A.

[0116] At point A, black (0 nit) is displayed in period ③' following period ①' (in which the display luminance at point A is 500 nits) and period ②' (in which the luminance at point A decreases).

[0117] At point B, the brightness suddenly increases to 500 nits at the start of period ③' following period ①' and period ②' (in period ①' and period ②', the display brightness at point B is 0 nit).

[0118] Since point A and point B are adjacent, when one suddenly turns black and the other suddenly turns white, the user can easily recognize the change. The screen saver operation of the display device may be recognized as strange and incomplete by such recognition, so that the user may think that the display device is defective or feel uncomfortable when using the display device.

[0119] In an embodiment, even when the position and / or brightness of the display area (or illumination area) changes during screen saver operation, different brightness levels may be provided based on the changed position so that the change is not noticeable.

[0120] Reference Figures 7 to 10 Further description Figure 2 Step S30 and step S40.

[0121] Figures 7 to 10Shown are a display area change (or illumination area change) and a brightness change in a screen saver operation in a display device according to an embodiment.

[0122] Figures 7 to 10 Shows that when Figure 2 When the total load value between two consecutive frames does not substantially change in step S10 and the load value of one or more blocks changes in step S20, the display apparatus proceeds to step S30.

[0123] Reference Figure 7 and Figure 9 In the screen saver operation, in step S30 (a step of checking the distance between blocks having different load values ​​for each block), white is displayed (or point A is illuminated) at point A. Subsequently, a video signal is input to allow white to be displayed at point B.

[0124] Will refer to Figure 7 and Figure 8 Describes the case where the display area (or illumination area) moves in the x-axis direction.

[0125] When the distance between the two blocks (or two irradiation areas) checked in the x-axis direction in step S30 is small, the brightness at point B does not increase to the brightness of white (500 nits), and the brightness at point B may show a grayscale lower than the intermediate grayscale. The small distance between the two blocks checked in step S30 may mean that the distance is less than the first reference distance. The first reference distance can be set based on one or more factors (such as the size of the display device and / or the number of blocks in the display panel).

[0126] When the distance between the two blocks (or two illumination areas) checked in step S30 is large, the brightness displayed at point B may be increased to the brightness of white (500 nits). The large distance between the two blocks checked in step S30 may mean that the distance is greater than the second reference distance. The second reference distance may be set based on one or more factors (such as the size of the display device and / or the number of blocks in the display panel).

[0127] When the distance between the two blocks checked in step S30 is between the first reference distance and the second reference distance, the brightness displayed at point B may be a brightness of an intermediate grayscale. According to an embodiment, the brightness displayed at point B may be an intermediate brightness between the brightness associated with the above small distance and the brightness associated with the above large distance.

[0128] According to an embodiment, a gain value is adjusted and multiplied by image data to determine a final data voltage to adjust displayed brightness according to a distance between blocks (or illumination areas) that changes according to a load value.

[0129] Figure 8 An example is shown in which the gain value is configured according to the distance value (distance-related numerical value). Figure 8 In , the x-axis represents the distance in the x-axis direction (represented by the number of blocks between two irradiation areas), and the y-axis represents the gain value. Figure 8 In the screen saver, the current gain indicates the gain value set before the screen saver operates.

[0130] Although Figure 8 The gain value is shown to vary nonlinearly according to the distance, but the gain value may be set to vary linearly, or may be set to have a constant gain value for a range of distance values.

[0131] Reference Figure 9 and Figure 10 Describes the case where the display area (or illumination area) moves in the y-axis direction.

[0132] When the distance between the two blocks (or two illumination areas) checked in step S30 is small, the brightness at point B may not increase to the brightness of white (500 nits), and the brightness at point B may show a grayscale lower than the intermediate grayscale. The small distance between the two blocks checked in step S30 may mean that the distance is less than the third reference distance. The third reference distance can be set based on one or more factors (such as the size of the display device and / or the number of blocks in the display panel).

[0133] When the distance between the two blocks (or two illumination areas) checked in step S30 is large, the brightness displayed at point B may be increased to the brightness of white (500 nits). The large distance between the two blocks checked in step S30 may mean that the distance is greater than the fourth reference distance. The fourth reference distance may be set based on one or more factors (such as the size of the display device and / or the number of blocks in the display panel).

[0134] When the distance between the two blocks checked in step S30 is between the third reference distance and the fourth reference distance, the brightness displayed at point B may be a brightness of an intermediate grayscale. According to an embodiment, the brightness displayed at point B may be an intermediate brightness between the brightness associated with the above small distance and the brightness associated with the above large distance.

[0135] According to an embodiment, a gain value is adjusted and multiplied by image data to determine a final data voltage to adjust brightness.

[0136] Figure 10 An example is shown in which the gain value is configured according to the distance value (distance-related numerical value). Figure 10 In , the x-axis represents the distance in the y-axis direction (represented by the number of blocks between two irradiation areas), and the y-axis represents the gain value. Figure 10 In the screen saver, the current gain indicates the gain value set before the screen saver operates.

[0137] Although Figure 10 The gain value is shown to vary nonlinearly according to the distance, but the gain value may be set to vary linearly, or may be set to have a constant gain value for a range of distance values.

[0138] Figures 7 to 10 The distance value (distance-related numerical value) between two blocks (or two irradiation areas) shown in FIG may not be an actual distance value (or length), but may be represented by the number of blocks disposed between the two blocks (or two irradiation areas). In an embodiment, when two adjacent blocks have a changed load value, the distance information / number may be 1 (or 0); when two blocks with a changed load value are spaced exactly one block apart from each other, the distance information / number may be 2 (or 1).

[0139] Only when the scheduled time is executed (see Figure 3 It can only be applied when t2) or longer Figures 7 to 10 The operations of steps S30 and S40 are shown in FIG. Compensating for the screen saver operation through steps S30, S40, and S50 is intended to prevent the user from recognizing a change in brightness value and feeling discomfort due to a rapid increase in brightness value during screen saver operation. Therefore, if the user does not visually recognize a change in display brightness that does not decrease quickly shortly after the screen saver operation has been executed, steps S30, S40, and S50 may not be performed.

[0140] Figures 7 to 10 Each of point A and point B in the image may be or correspond to one block or multiple blocks. Each of point A and point B may be or correspond to a portion of one block. When they correspond to multiple blocks, it may be necessary to compare position information between the blocks.

[0141] exist Figures 7 to 10 In the embodiment, the case where the display area (or illumination area) moves in one of the x-axis and y-axis directions has been described as an example. The display area (or illumination area) can move in both the x-axis and y-axis directions, and in this case, as shown in FIG. Figure 12 As shown in , two distance gain information sets / values ​​can be synthesized, and a final gain value can be calculated based on the synthesized information sets / values. There are various ways to synthesize the two information sets / values. For example, the larger of the two values, the average of the two values, the product of the two values, or the sum of the two values ​​can be used.

[0142] Figure 11 A block diagram illustrating a timing controller 1000 of a display device according to an embodiment is shown.

[0143] The timing controller 1000 includes frame memories 1100 and 1200 (which may include one or more hardware circuits), total load summing units 1300 and 1400 , a total load comparing unit 1500 , a block load comparing unit 1600 , a counter 1700 , and a gain determining unit 1800 .

[0144] A pair of frame memories 1100 and 1200 stores image data of one frame, and includes 128 frame memories 1101 and 1201 for each block.

[0145] exist Figure 11 , image data of a current frame (Nth frame) is stored in the right frame memory 1200, and image data of a previous frame (N-1th frame) is stored in the left frame memory 1100. According to an embodiment, when image data of odd-numbered frames is stored in the left frame memory 1100, image data of even-numbered frames may be stored in the right frame memory 1200.

[0146] In the frame memories 1101 and 1201 for each block, image data of one frame transferred to the corresponding block is stored.

[0147] The image data stored in the frame memories 1100 and 1200 are transferred to the total load summing units 1300 and 1400 and the block load comparing unit 1600 .

[0148] First, the path through which image data is transmitted to the total load summing units 1300 and 1400 is described.

[0149] Image data of one frame stored in each of the frame memories 1100 and 1200 are respectively transferred to the total load summing units 1300 and 1400 , and a total load value LS-Total of the image data is calculated.

[0150] The total load value LS-Total of the previous frame (N-1 frame) and the total load value LS-Total of the current frame (N frame) are transmitted to the total load comparison unit 1500. The total load comparison unit 1500 performs comparison to determine whether the total load values ​​LS-Total of the two input frames are not different to check whether there is a change. The comparison in the total load comparison unit 1500 corresponds to Figure 2Step S10. When there is no difference in the total load values ​​LS-Total of the two frames, the total load comparison unit 1500 does not output an enable signal (SS (screen saver) enable based on the total load) to the gain determination unit 1800. The total load comparison unit 1500 can be configured to not output an enable signal (SS enable based on the total load) when a threshold (SS threshold load value based on the total load, also referred to as the threshold of the total load value hereinafter) for not outputting the enable signal (SS enable based on the total load) completely matches the total load values ​​LS-Total of the two frames according to the setting, or when the difference is less than or equal to the threshold (SS threshold load value based on the total load). The threshold (SS threshold load value based on the total load) can be configured by the user.

[0151] A path through which image data stored in the frame memories 1100 and 1200 is transferred to the block load comparison unit 1600 is described.

[0152] The image data stored in the frame memories 1101 and 1201 for each block of the frame memories 1100 and 1200 are transferred to the block load comparison unit 1600 for each block, and the load value of each block is compared based on the same block to check whether there is any (significant) difference and whether there is a (significant) change. The comparison in the block load comparison unit 1600 corresponds to Figure 2 Step S20.

[0153] exist Figure 11 , the load value LS-1 of the first block of the previous frame (N-1 frame) is compared with the load value LS-1 of the first block of the current frame (N frame), and the load value LS-2 of the second block of the previous frame (N-1 frame) is compared with the load value LS-2 of the second block of the current frame (N frame). The load value of each block is compared in sequence, and the operation ends after comparing the load value LS-128 of the 128th block of the previous frame (N-1 frame) with the load value LS-128 of the 128th block of the current frame (N frame).

[0154] As a result, the block load comparison unit 1600 can identify the blocks having a difference and output the position information (block coordinate information) of the blocks having a difference to the gain determination unit 1800. When receiving an enable signal (SS enable based on block load) from the counter 1700, the block load comparison unit 1600 can output the position information (block coordinate information) of the blocks.

[0155] When the load values ​​of the blocks are completely unchanged, or when the difference is less than or equal to a threshold (SS threshold load value based on block load; also referred to as the threshold of the load value of each block below), each block can be considered to have no difference in load value. The threshold (SS threshold load value based on block load) can be predetermined. The threshold (SS threshold load value based on block load) can be configured by the user.

[0156] The counter 1700 receives a signal (SS enable counter) from the block load comparison unit 1600 and counts the number of blocks, and outputs a final count value (SS counter value) to the gain determination unit 1800 .

[0157] The number of blocks counted in the counter 1700 is information for checking how much time has passed. It is possible to check the total elapsed time by continuously counting the number of blocks of all frames, and the total elapsed time is used as the time information in the example. Figure 3 、 Figure 7 and Figure 9 The time information required to show the brightness or gain value changes over time. Figure 11 In an embodiment, the number of counted blocks is used instead of time information. According to an embodiment, the counter 1700 can obtain time information by counting only the number of frames.

[0158] The counter 1700 compares a threshold value (SS threshold counter value; also referred to as counter threshold value hereinafter) with a final count value (SS counter value), and when the final count value (SS counter value) exceeds the threshold value (SS threshold counter value), generates an enable signal (block load-based SS enable) to output it to the block load comparison unit 1600 and the gain determination unit 1800.

[0159] The threshold value of counter 1700 (SS threshold counter value) can be Figure 3 In this case, the block load comparison unit 1600 and the gain determination unit 1800 can perform the screen saver operation by the enable signal (SS enable based on the block load) output from the counter 1700.

[0160] The threshold value (SS threshold counter value) of the counter 1700 may also include Figure 3 The value corresponding to the time point at which the period ③ shown in FIG2 starts corresponds to the minimum gain start time at the end of period t2. In this case, the block load comparison unit 1600 and the gain determination unit 1800 can be executed by the enable signal (SS enable based on the block load) output from the counter 1700. Figure 2 Step S30, step S40 and step S50.

[0161] The gain determination unit 1800 receives an enable signal (SS enable based on the total load), an enable signal (SS enable based on the block load), a final count value (SS counter value) of the counter 1700, and block position information (block coordinate information) of a block having a (significant) difference in the block load comparison unit 1600 to output a final gain value (SS gain).

[0162] Reference Figure 12 The operation of the gain determination unit 1800 is further described.

[0163] Figure 12 A block diagram of a gain determination unit 1800 according to an embodiment is shown.

[0164] The gain determination unit 1800 includes a block coordinate information receiving unit 1810 , coordinate analyzing units 1820 and 1840 , gain calculating units 1830 and 1850 , a synthesizing unit 1860 , and a final gain calculating unit 1870 .

[0165] The block coordinate information receiving unit 1810 receives position information (block coordinate information) of blocks having different load values ​​from the block load comparing unit 1600 and then transmits the position information to the coordinate analyzing units 1820 and 1840 .

[0166] The coordinate analysis units 1820 and 1840 include a ΔX coordinate analysis unit 1820 and a ΔY coordinate analysis unit 1840. The x-axis distance and / or y-axis distance between two blocks (or two irradiation areas) with changed load values ​​are calculated based on the block coordinate information. The x-axis distance and the y-axis distance may not be actual lengths, but may be represented by (a function of) the number of blocks disposed between the two blocks (or two irradiation areas). In an embodiment, when two adjacent blocks have changed load values, the distance information may be 1 (or 0); when two blocks with changed load values ​​are spaced exactly one block apart from each other, the distance information may be 2 (or 1).

[0167] The x-axis distance (ΔX) between blocks calculated by the ΔX coordinate analysis unit 1820 is input to the gain calculation unit (according to ΔX) 1830 to obtain the gain value of the x-axis distance. The x-axis gain value (gain according to ΔX) can be obtained by Figure 8 The curve (or function) shown in is used to determine.

[0168] The y-axis distance (ΔY) between the blocks calculated by the ΔY coordinate analysis unit 1840 is input to the gain calculation unit (according to ΔY) 1850 to obtain the gain value of the y-axis distance. The y-axis gain value (according to the gain of ΔY) can be obtained by Figure 10 The curve (or function) shown in is used to determine.

[0169] The x-axis gain value (gain according to ΔX) and the y-axis gain value (gain according to ΔY) are transmitted to the synthesis unit 1860 .

[0170] Synthesis unit 1860 synthesizes the x-axis gain value (gain according to ΔX) and the y-axis gain value (gain according to ΔY). Depending on the embodiment, a method for synthesizing the gain values ​​may be determined based on the total distance. For example, a method may be used in which the larger value is selected from the x-axis gain value (gain according to ΔX) and the y-axis gain value (gain according to ΔY). Depending on the embodiment, an average value, a product of the two values, or a sum of the two values ​​may be used.

[0171] The synthesized gain value is transmitted to the final gain calculation unit 1870 .

[0172] The final gain calculation unit 1870 calculates a final gain value (SS gain) by using the synthesized gain value and the final count value (SS counter value) input from the counter 1700. The final gain calculation unit 1870 may include a lookup table stored in a hardware memory unit, and the lookup table may store the final gain value (SS gain) for the synthesized gain value and the final count value (SS counter value) input from the counter 1700.

[0173] In an embodiment, the final count value (SS counter value) includes time information.

[0174] The final gain value (SS gain) achieves different brightness levels according to the distance that the display area (or the illuminated area adjacent to or surrounded by the non-illuminated area) moves during the screen saver operation. In an embodiment, when the distance is short, the brightness does not increase quickly or significantly, so that the user does not feel the difference in brightness. When the distance is long, the user is unlikely to recognize the difference in brightness, so that the display brightness can be set to high.

[0175] As a result, users will not feel discomfort while using the screensaver.

[0176] Although example embodiments have been described, actual embodiments are not limited to the described embodiments and are intended to cover various modifications and equivalent arrangements within the scope of the appended claims.

Claims

1. A display device, comprising: Display panel; a data driver electrically connected to the display panel and configured to apply a first set of data voltages and subsequently a second set of data voltages to the display panel during a screen saver operation of the display device, wherein the first set of data voltages causes the display panel to display a first illuminated area proximate to a first non-illuminated area, and wherein the second set of data voltages causes the display panel to display a second illuminated area proximate to a second non-illuminated area; and a timing controller electrically connected to the data driver and configured to supply image data to the data driver for the second data voltage group so that the second illumination area has a predetermined brightness level, wherein the timing controller determines a brightness-related value for controlling the predetermined brightness level based on a distance-related value, wherein the distance-related value depends on a distance between a position of the first illumination area and a position of the second illumination area, wherein the brightness of the first illumination area and the brightness of the second illumination area vary during operation of the screen saver, and Wherein, when the distance-related value is a first value, the timing controller determines the brightness-related value as a first value, and wherein, when the distance-related value is a second value greater than the first value, the timing controller determines the brightness-related value as a second value greater than the first value.

2. The display device according to claim 1, wherein The first value is less than a first reference value, wherein the second value is greater than a second reference value, and wherein, when the distance-related value is greater than the first reference value and less than the second reference value, the timing controller determines the brightness-related value to be greater than the first value and less than the second value.

3. The display device according to claim 1, wherein The display panel is divided into blocks arranged in a matrix, and wherein the distance-related value is a number of one or more of the blocks.

4. The display device according to claim 1, wherein When the first irradiation area has been irradiated for a predetermined time or longer, the timing controller gradually reduces the brightness of the first irradiation area to a predetermined brightness level.

5. The display device according to claim 1, wherein The display panel is divided into blocks, and wherein the timing controller includes: a first frame memory; a second frame memory; a first total load summing unit connected to the first frame memory; a second total load summing unit connected to the second frame memory; a total load comparison unit connected to each of the first total load summing unit and the second total load summing unit; a block load comparison unit connected to each of the first frame memory and the second frame memory; and The gain determination unit is configured to receive outputs of the total load comparison unit and the block load comparison unit to determine the brightness related value. The display device according to claim 5 , wherein: The timing controller further includes a counter configured to transmit a count value to the gain determination unit.

7. The display device according to claim 6, wherein: The counter outputs an enable signal to activate the block load comparison unit and the gain determination unit, and The counter compares the count value with a counter threshold, and when the count value is greater than the counter threshold, the counter outputs the enable signal.

8. The display device according to claim 5, wherein The total load comparison unit compares a threshold with a difference between the total load value of the first total load summing unit and the total load value of the second total load summing unit, and wherein, when the difference is smaller than the threshold, the total load comparison unit does not output an enable signal to the gain determination unit.

9. The display device according to claim 5, wherein: The first frame memory stores first image data associated with a previous frame for all the blocks, wherein the second frame memory stores second image data associated with a current frame for all the blocks, wherein the block load comparison unit compares a load threshold value with a difference between values ​​stored in the first frame memory and the second frame memory for each block, and wherein when the difference associated with a block is less than the load threshold value, the block load comparison unit regards the load value of the block as unchanged.

10. The display device according to claim 6, wherein The gain determination unit receives block coordinate information from the block load comparison unit to calculate the brightness related value, and wherein the block coordinate information is related to the position of the second illumination area, Wherein, the gain determination unit includes: a block coordinate information receiving unit, configured to receive the block coordinate information from the block load comparison unit; a first coordinate analysis unit and a second coordinate analysis unit configured to respectively identify x-axis distance information and y-axis distance information using the block coordinate information; a first gain calculation unit, configured to obtain an x-axis gain value based on the x-axis distance information; a second gain calculation unit, configured to obtain a y-axis gain value based on the y-axis distance information; a synthesis unit configured to synthesize the x-axis gain value and the y-axis gain value to generate a synthesized gain value; and a gain calculation unit configured to calculate the brightness related value based on the composite gain value, and The gain calculation unit receives the count value from the counter to determine the brightness-related value based on the count value.

11. A display method for a display device, the display device comprising a display panel, the display method comprising: In a first step, a total load value of a previous frame is compared with a total load value of a current frame to check a first condition related to whether a total load change exceeds a total load change threshold; a second step of comparing the load value of the previous frame and the load value of the current frame for each block to check a second condition related to whether a block load change exceeds a block load change threshold; Step three, when both the first condition and the second condition are false, executing a screen saver operation; as well as a fourth step of adjusting the brightness of the second illuminated area on the display panel based on a distance between a position of the second illuminated area and a position of the first illuminated area on the display panel when the first condition is false but the second condition is true, wherein the first illuminated area is immediately adjacent to a first non-illuminated area on the display panel, and wherein the second illuminated area is immediately adjacent to a second non-illuminated area on the display panel, wherein the brightness of the first illumination area and the brightness of the second illumination area vary during operation of the screen saver, and The fourth step further includes: When the distance is represented by a first numerical value, setting the brightness of the second illumination area to a first brightness level; and When the distance is represented by a second numerical value greater than the first numerical value, the brightness of the second illumination area is set to a second brightness level higher than the first brightness level.

12. The display method according to claim 11, wherein: The total load change threshold is greater than zero, wherein the block load change threshold is greater than zero, and Wherein, when the third step has been executed for a predetermined time or longer, the fourth step is executed.

13. The display method according to claim 11, wherein: The third step further includes gradually reducing the brightness of the first illumination area to a predetermined brightness level when the first illumination area has been illuminated for a predetermined length of time or longer.

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