Timing controller of display apparatus

Abstract

This disclosure discloses a timing controller for a display device with overdrive functionality. The timing controller includes: a data receiving circuit configured to receive display data; an overdrive circuit configured to overdrive the display data; and a data transmission circuit configured to transmit the overdriven display data.

Description

Technical Field

[0001] The various implementations generally relate to timing controllers for display devices, and more specifically, to timing controllers for display devices capable of actively responding to refresh rates that change according to frame frequency. Prior Technology

[0002] LCD panels and OLED panels are widely used as display panels. LCD panels use LCD elements to form pixels, while OLED panels use OLED elements to form pixels.

[0003] Each pixel has a unique response time required from the point in time when a source signal corresponding to the display data is applied to emit light with a brightness corresponding to the voltage level of the source signal.

[0004] In particular, when the difference between the display data of the previous frame and the current frame is large, the pixel needs more time to emit light at the desired level. That is, when the voltage level of the source signal of the previous frame is low and the voltage level of the source signal of the current frame is high, or when the voltage level of the source signal of the previous frame is high and the voltage level of the source signal of the current frame is low, the pixel element needs more time to display the desired brightness.

[0005] When a pixel does not display the desired level of brightness during the driving time of the current frame, a blurred and overlapping afterimage may be displayed on the screen.

[0006] The display device can employ overdrive to eliminate afterimages.

[0007] Overdriving is the process of providing a source signal to a pixel at a higher voltage level than the original display data. It can compensate for overdriving of the display data and provide a source signal to the pixel at a higher voltage level corresponding to the compensated display data. Therefore, pixel response time can be improved, and consequently, afterimages can be eliminated.

[0008] Typically, the frames used for displaying on a screen can be set to have a constant frequency. In other words, the display panel can have a fixed frame rate, and correspondingly, the refresh rate can be fixed. Therefore, an overdrive value for overdrive can be provided based on a fixed refresh rate.

[0009] However, the frame rate can be changed as needed. For example, the frame rate can be changed from 120Hz to 60Hz, or from 60Hz to 120Hz. Thus, if the frame rate changes, the refresh rate changes. A change in the refresh rate means a change in the timing of the source signal being applied to the pixel.

[0010] If the overdrive value is fixed and the refresh rate decreases, the source signal may be overdriven. As a result, a redundant image may form on the screen. Conversely, if the overdrive value is fixed and the refresh rate increases, the source signal may be underdriven. As a result, a redundant image may form.

[0011] Therefore, the overdrive value needs to be appropriately controlled in accordance with the change in refresh rate based on the change in frame frequency. Summary of the Invention

[0012] Various implementations are intended to provide a timing controller for an overdriven display device capable of controlling display data in accordance with a refresh rate that changes according to the frame frequency.

[0013] In one embodiment, the timing controller of the display device may include an overdrive circuit configured to receive display data for each frame and perform overdrive on the display data. The overdrive circuit stores a plurality of lookup tables, each of which has an overdrive value corresponding to the difference between display data of consecutive frames, and the lookup tables correspond to the refresh rate of the frames. The overdrive circuit selects the overdrive value from the lookup table corresponding to the current refresh rate of the frame as an overdrive control value. The overdrive circuit performs overdrive on the display data via the overdrive control value.

[0014] In one embodiment, the timing controller of the display device may include: an overdrive circuit configured to receive display data for each frame and perform overdrive on the display data, wherein the overdrive circuit stores a plurality of lookup tables, each of the lookup tables having an overdrive value corresponding to the difference between display data of consecutive frames, and the lookup tables correspond to the refresh rate of the frames, wherein the overdrive circuit uses an interpolated value of the overdrive value of the lookup table corresponding to the refresh rate adjacent to the current refresh rate as an overdrive control value, and wherein the overdrive circuit performs overdrive on the display data via the overdrive control value.

[0015] In one embodiment, the timing controller of the display device may include: an overdrive circuit configured to receive display data for each frame and perform overdrive on the display data, wherein the overdrive circuit stores a lookup table corresponding to a reference refresh rate, the lookup table having overdrive values ​​corresponding to the differences in display data of consecutive frames, wherein the overdrive circuit generates an overdrive control value by calculating a weight corresponding to the current refresh rate of the frame and an overdrive value corresponding to the difference, and wherein the overdrive circuit performs overdrive on the display data via the overdrive control value.

[0016] In an embodiment, the timing controller of the display device may include: a data receiving circuit configured to receive display data in which the refresh rate of a frame changes; an overdrive control unit configured to receive the display data received by the data receiving circuit, detect the current refresh rate of the frame, check the difference between the first display data of the current frame and the second display data of the previous frame, and provide an overdrive control value that changes according to the current refresh rate and the difference; an overdrive processing unit configured to perform overdrive on the display data received by the data receiving circuit and control the voltage level of the overdrive via the overdrive control value; and a data transmission circuit configured to transmit the overdrive display data in the overdrive processing unit.

[0017] The embodiments of this disclosure can detect refresh rates that change according to frame frequency, and can adjust the overdrive control value applied to the overdrive of the display data in accordance with the current refresh rate.

[0018] Therefore, even when the frame rate changes, the embodiments of this disclosure can compensate for overdrive of display data in a way that adapts to the current refresh rate.

[0019] In other words, according to the embodiments of this disclosure, even when the refresh rate increases or decreases, overdrive can be controlled by display data that is compensated in accordance with the current refresh rate, and as a result, the formation of inverted or redundant images on the screen can be prevented. Simple Explanation of the Diagram

[0020] Figure 1 is a block diagram illustrating a display device according to an embodiment of the present disclosure.

[0021] Figure 2 is a detailed block diagram illustrating an implementation of the timing controller shown in Figure 1.

[0022] Figure 3 is a detailed block diagram showing an example of the storage unit and the control value adjustment unit.

[0023] Figure 4 is a detailed block diagram showing another example of the storage unit and the control value adjustment unit.

[0024] Figure 5 is a graph illustrating the control of overdrive display data as the refresh rate increases.

[0025] Figure 6 is a graph showing how brightness changes as the refresh rate increases, controlled by the display data used for overdrive.

[0026] Figure 7 is a graph illustrating the control of overdrive display data when the refresh rate decreases.

[0027] Figure 8 is a graph showing how brightness changes as the refresh rate decreases, controlled by the display data used for overdrive. Implementation

[0028] Display panels, such as LCD panels or OLED panels, can be driven by the display device of this disclosure shown in FIG1.

[0029] The display device in Figure 1 is illustrated as including a timing controller 10, a data driver 20, and a display panel 30. The timing controller 10 is shown to include an overdrive circuit 100.

[0030] The timing controller 10 is configured to receive display data RXD from an external data source, overdrive the display data RXD through the drive circuit 100, and output display data TXD that has been overdriven and compensated.

[0031] External data sources can be understood as various devices or systems that provide data for display.

[0032] Overdriving means compensating for display data to drive the source signals provided from the data driver 20 to the pixels of the display panel 30 to a higher voltage level.

[0033] For overdrive, the overdrive circuit 100 can compensate the display data RXD via an overdrive control value and output display data TXD corresponding to the compensation result. It can be understood that the overdrive-after display data TXD is corrected to have a value that can drive a source signal with a higher voltage level compared to the display data RXD before overdrive.

[0034] The configuration of the drive circuit 100 will be described later with reference to Figure 2.

[0035] The timing controller 10 can configure the display data TXD output from the overdrive circuit 100 into a packet and can transmit the packet to the data driver 20. The timing controller 10 can transmit the information by including information necessary for the operation of the data driver 20 and the driving of the display panel 30 (e.g., vertical synchronization signal, etc.) in the packet.

[0036] The data driver 20 is configured to receive display data TXD output from the timing controller 10, generate a source signal SOUT corresponding to the display data TXD, and provide the source signal SOUT to the display panel 30.

[0037] The data driver 20 may include a portion for retrieving display data, a portion for performing digital processing by means of a process such as latching, and a portion for generating and outputting an analog source signal SOUT in response to the display data.

[0038] Data drive 20 can be understood as corresponding to a general source drive, and detailed configuration instructions and operation explanations for data drive 20 will be omitted.

[0039] The source signal SOUT can have a voltage level corresponding to a specific gray level voltage within a preset gray level range. It can be understood that the voltage level of the source signal SOUT is determined by the value of the displayed data.

[0040] The display panel 30 is configured to include a plurality of pixels for displaying a screen, and the pixels can be configured, for example, to have a plurality of rows and a plurality of columns. A source signal SOUT can be provided to the rows simultaneously. Column signals (not shown) can be provided to the columns sequentially. Therefore, the pixels can emit light sequentially through the units of the horizontal lines.

[0041] According to embodiments of this disclosure, due to overdrive, the voltage level of the source signal SOUT can be higher than the voltage level corresponding to the display data RXD. Embodiments of this disclosure are configured such that when the overdrive circuit 100 operates, it overdrives the display data RXD to a voltage level suitable for the current refresh rate corresponding to the change in frame frequency.

[0042] The overdrive circuit 100 can be described with reference to Figure 2. Figure 2 is a detailed block diagram of the timing controller 10 shown in Figure 1.

[0043] The timing controller 10 can be exemplified as including a data receiving circuit 12, an overdrive circuit 100, and a data transmission circuit 14.

[0044] The data receiving circuit 12 is configured to receive display data RXD from an external data source and output display data FDA in frames. The data receiving circuit 12 is configured to provide display data FDA to the overdrive processing unit 110, the difference checking unit 120, the frame buffer 130, and the refresh rate detection unit 140 of the overdrive circuit 100.

[0045] The data receiving circuit 12 can receive display data RXD in frames. A frame can be understood as the full-size screen of the display panel 30.

[0046] Considering the image quality of the screen, the frequency of the frames displayed on the display panel 30 can be changed. That is, the refresh rate of the display panel 30 can be changed.

[0047] In other words, increasing the frame rate means increasing the refresh rate, and decreasing the frame rate means decreasing the refresh rate. When the refresh rate increases, the number of frames displayed within a given time increases, and the time allocated to displaying one frame decreases. Conversely, when the refresh rate decreases, the number of frames displayed within a given time decreases, and the time allocated to displaying one frame increases.

[0048] The data receiving circuit 12 can receive display data RXD whose refresh rate changes as described above.

[0049] The overdrive circuit 100 is configured to overdrive the display data FDA of the frame units provided from the data receiving circuit 12, and to provide the data transmission circuit 14 with display data whose values ​​have been compensated by the overdrive.

[0050] The data transmission circuit 14 is configured to output display data TXD having values ​​compensated by the drive. The data transmission circuit 14 can configure the display data TXD as a packet, and the packet can be configured to include not only the display data TXD, but also information necessary for the operation of the data driver 20 and the driving of the display panel 30 (e.g., vertical sync signals, etc.).

[0051] In the above configuration, the overdrive circuit 100 can be exemplified as including an overdrive processing unit 110 and an overdrive control unit 112.

[0052] The overdrive processing unit 110 is configured to receive display data FDA of frame units via the data receiving circuit 12, and to receive overdrive control value ODV from the overdrive control unit 112.

[0053] The overdrive processing unit 110 can perform overdrive on the display data FDA by using the overdrive control value ODV, and can control the overdrive voltage level by using the overdrive control value ODV.

[0054] The overdrive processing unit 110 is configured to provide display data with values ​​corrected by overdrive to the data transmission circuit 14.

[0055] The overdrive control unit 112 is configured to receive display data FDA of frame units from the data receiving circuit 12, generate an overdrive control value ODV using the display data FDA, and provide the overdrive control value ODV to the overdrive processing unit 110.

[0056] More specifically, the overdrive control unit 112 is configured to detect the current refresh rate of the frame by means of the display data FDA, check the difference between the first display data of the current frame and the second display data of the previous frame, and provide an overdrive control value ODV that changes according to the current refresh rate and the difference. The first display data of the current frame can be understood as the display data FDA provided from the data receiving circuit 12, and the second display data of the previous frame can be understood as the display data FDA provided from the data receiving circuit 12 during the period of the previous frame. In the following description, the first display data of the current frame will be referred to as display data FDA, and the second display data of the previous frame will be referred to as display data FDA_P.

[0057] In order to check the difference DVC between the display data FDA of the current frame and the display data FDA_P of the previous frame, the overdrive control unit 112 may include a difference checking unit 120 and a frame buffer 130.

[0058] The frame buffer 130 is configured to update the display data FDA provided from the data receiving circuit 12 at frame intervals.

[0059] In other words, the frame buffer 130 stores the display data FDA_P of the previous frame, and when it receives the display data FDA of the current frame, it provides the display data FDA_P of the previous frame to the difference checking unit 120, and then stores the display data FDA of the current frame.

[0060] The difference checking unit 120 is configured to receive the display data FDA of the current frame and the display data FDA_P of the previous frame provided by the data receiving circuit 12 from the frame buffer 130, and output the difference value DVC. More specifically, the difference checking unit 120 can calculate the difference between the value of the display data FDA_P of the previous frame and the value of the display data FDA of the current frame, and can output the difference value DVC as the calculation result.

[0061] In order to detect the current refresh rate of the frame, the overdrive control unit 112 may include a refresh rate detection unit 140.

[0062] For example, the refresh rate detection unit 140 can detect the refresh rate by counting the display data FDA for each frame based on the frame rate.

[0063] That is, the refresh rate detection unit 140 can be configured to detect the current refresh rate and output a refresh rate value FRD corresponding to the current refresh rate.

[0064] The overdrive control unit 112 is configured to provide an overdrive control value ODV, which changes based on the difference between the current refresh rate detected by the refresh rate detection unit 140 and the difference check unit 120. For this purpose, the overdrive control unit 112 may include a storage unit 150 and a control value adjustment unit 160.

[0065] In this disclosure, the storage unit 150 and the control value adjustment unit 160 can be implemented differently.

[0066] Firstly, as a first embodiment, this disclosure can be configured such that the overdrive control unit 112 stores multiple lookup tables for corresponding refresh rates, selects a lookup table that matches the refresh rate, and provides an overdrive control value ODV.

[0067] Therefore, the storage unit 150 is configured to store multiple lookup tables, each having an overdrive value corresponding to the difference DVC and each corresponding to the refresh rate. This will be described with reference to Figure 3.

[0068] For example, the storage unit 150 may be configured to store a first lookup table TA1 corresponding to a refresh rate corresponding to a frame frequency of 40Hz, a second lookup table TA2 corresponding to a refresh rate corresponding to a frame frequency of 60Hz, and a third lookup table TAn corresponding to a refresh rate corresponding to a frame frequency of 120Hz.

[0069] Each of the tables TA1, TA2, and TAn can have overdrive values ​​corresponding to various difference DVC values. For example, each of the tables TA1, TA2, and TAn can store overdrive values ​​corresponding to difference DVC values ​​of 64, 96, 128, 192, and 256 gray levels, respectively.

[0070] The storage unit 150 is configured to respond to a request from the control value adjustment unit 160 by providing an overdrive value selected by the difference value DVC in a lookup table selected by the refresh rate value FRD of the control value adjustment unit 160.

[0071] The control value adjustment unit 160 is configured to select a lookup table in the storage unit 150 corresponding to the refresh rate value FRD and provide the overdrive control value ODV corresponding to the difference value DVC in the selected lookup table to the overdrive processing unit 110.

[0072] Therefore, the control value adjustment unit 160 can receive the refresh rate value FRD, provide the refresh rate value FRD to the storage unit 150, and thereby request the storage unit 150 to provide an overdrive value.

[0073] In response to this request, the storage unit 150 can provide an overdrive value corresponding to the difference DVC in a lookup table for the refresh rate corresponding to the refresh rate value FRD. For example, when the difference DVC corresponding to a 256-grayscale difference is provided to the storage unit 150 and the refresh rate value FRD corresponding to a frame frequency of 120Hz is provided to the control value adjustment unit 160, the storage unit 150 can provide an overdrive value corresponding to the difference DVC corresponding to a 256-grayscale difference in a third lookup table TAn corresponding to the refresh rate value FRD.

[0074] The control value adjustment unit 160 can provide the overdrive value received by providing the refresh rate value FRD to the storage unit 150 as the overdrive control value ODV.

[0075] As a result, the overdrive processing unit 110 can overdrive the display data FDA of the current frame by means of the overdrive control value ODV provided by the control value adjustment unit 160.

[0076] As a second embodiment, this disclosure can be configured such that the overdrive control unit 112 stores multiple lookup tables for the corresponding refresh rate, generates interpolated values ​​adapted to the refresh rate, and provides the interpolated values ​​as overdrive control values ​​ODV.

[0077] The second embodiment can be described with reference to Figure 3.

[0078] In the second embodiment, the overdrive control unit 112 is configured to select a lookup table adjacent to the current refresh rate by means of the refresh rate value FRD, select an overdrive value corresponding to the difference DVC in the selected lookup table, generate an interpolation value of the selected overdrive value and provide the interpolation value as the overdrive control value ODV.

[0079] Therefore, the storage unit 150 stores lookup tables for interpolation. These lookup tables for interpolation can be understood as the first lookup table TA1 corresponding to a refresh rate corresponding to a frame frequency of 40Hz, the second lookup table TA2 corresponding to a refresh rate corresponding to a frame frequency of 60Hz, and the third lookup table TAn corresponding to a refresh rate corresponding to a frame frequency of 120Hz, as described in the first embodiment. Based on the description of the first embodiment, the overdrive value stored in each of the lookup tables TA1, TA2, and TAn can be understood.

[0080] The storage unit 150 is configured to select a lookup table corresponding to the current refresh rate of the refresh rate value FRD adjacent to the control value adjustment unit 160 and provide the overdrive value corresponding to the difference DVC of the selected lookup table.

[0081] Therefore, the control value adjustment unit 160 can receive the refresh rate value FRD, provide the refresh rate value FRD to the storage unit 150, and thereby request the storage unit 150 to provide an overdrive value.

[0082] In response to the request, the storage unit 150 can provide the overdrive value corresponding to the difference DVC in the lookup table corresponding to the refresh rate adjacent to the current refresh rate corresponding to the refresh rate value FRD.

[0083] For example, when the current refresh rate corresponds to a frame frequency between 60Hz and 120Hz, the storage unit 150 can select the second lookup table TA2 and the third lookup table TAn adjacent to the current refresh rate by means of the refresh rate value FRD, and can provide the overdrive value corresponding to the difference value DVC of the selected second lookup table TA2 and the third lookup table TAn in response to the request of the control value adjustment unit 160.

[0084] The control value adjustment unit 160 receives the overdrive value received by providing the refresh rate value FRD to the storage unit 150. The overdrive value can be understood as the overdrive value corresponding to the difference DVC in the lookup table corresponding to the refresh rate adjacent to the current refresh rate.

[0085] The control value adjustment unit 160 is configured to generate an interpolated value of the overdrive value received as described above, and provide the interpolated value as the overdrive control value ODV.

[0086] As a result, the overdrive processing unit 110 can overdrive the display data FDA of the current frame by means of the overdrive control value ODV provided by the control value adjustment unit 160.

[0087] As a third embodiment, this disclosure can be configured such that the overdrive control unit 112 stores a reference lookup table for the refresh rate and provides an overdrive control value ODV by applying a weight corresponding to the current refresh rate to the overdrive value.

[0088] Therefore, the storage unit 150 is configured to store a reference lookup table TA containing overdrive values ​​corresponding to the difference DVC. This will be described with reference to Figure 4.

[0089] For example, the storage unit 150 can be configured to store a reference table TA corresponding to a refresh rate corresponding to a frame frequency of 60Hz.

[0090] The reference table TA can have overdrive values ​​corresponding to the difference DVC. For example, the reference table TA can store overdrive values ​​corresponding to the difference DVC of 64 grayscale difference, 96 grayscale difference, 128 grayscale difference, 192 grayscale difference, and 256 grayscale difference.

[0091] The storage unit 150 is configured to provide a reference to the overdrive value selected by the differential DVC in the data sheet TA in response to a request from the control value adjustment unit 160.

[0092] The control value adjustment unit 160 is configured to use the refresh rate value FRD as a weight and provide an overdrive control value ODV obtained by calculating the weight and the overdrive value corresponding to the difference DVC.

[0093] Therefore, the control value adjustment unit 160 can receive the refresh rate value FRD, provide the refresh rate value FRD to the storage unit 150, and thereby request the storage unit 150 to provide an overdrive value.

[0094] In response to the request, the storage unit 150 can provide the overdrive value corresponding to the difference DVC in the reference table TA.

[0095] The control value adjustment unit 160 can use the refresh rate value FRD as a weight, and can provide an overdrive control value ODV obtained by calculating the weight and the overdrive value corresponding to the difference DVC received from the storage unit 150.

[0096] Based on the above description, it can be seen that the refresh rate value FRD is used as a weight to transform the overdrive value of the reference lookup table TA in accordance with the current refresh rate.

[0097] As a result, the overdrive processing unit 110 can overdrive the display data FDA of the current frame by means of the overdrive control value ODV provided by the control value adjustment unit 160.

[0098] In the first to third embodiments of the present disclosure described above with reference to FIGS. 1 to 4, the overdrive control unit 112 can output an overdrive control value ODV to have hysteresis characteristics. For this purpose, the control value adjustment unit 160 may include a Schmitt trigger circuit 162 with hysteresis characteristics, and may be configured to output the overdrive control value ODV by means of the Schmitt trigger circuit 162.

[0099] When the source signal applied to a pixel changes continuously according to the refresh rate, abnormal phenomena may occur on the screen. It is understood that the hysteresis characteristic of the overdrive control unit 112 prevents screen abnormalities by mitigating changes in the source signal.

[0100] The above-described embodiments of this disclosure can appropriately control overdrive based on the current refresh rate corresponding to the change in frame frequency.

[0101] This will be described below with reference to Figures 5 through 8.

[0102] In Figures 5 to 8, the display data of the third and fourth frames have significantly higher values ​​than those of the first and second frames. Therefore, the brightness of the third and fourth frames is significantly higher than that of the first and second frames.

[0103] In Figures 5 and 7, DW indicates display data without overdrive, DN indicates display data overdrive by a fixed overdrive control value ODV independent of refresh rate changes, and DO indicates display data overdrive by an overdrive control value ODV that changes with the current refresh rate according to an embodiment of this disclosure. Additionally, in Figures 6 and 8, LW represents the brightness caused by display data DW, LN represents the brightness caused by display data DN, and LO represents the brightness caused by display data DO.

[0104] Figures 5 and 6 are graphs used to explain the changes in display data as the frame rate changes from a low frame rate (e.g., 60 Hz) to a high frame rate (e.g., 120 Hz) and the changes in brightness caused by overdrive in the embodiments of the present disclosure.

[0105] As shown in Figures 5 and 6, the large difference in display data between the second and third frames may make it difficult to express sufficient brightness even at a refresh rate corresponding to a frame rate of 60Hz.

[0106] In this design, the display data DW should be overdriven to express sufficient brightness at a refresh rate corresponding to a frame rate of 60Hz. In other words, the display data DW will be changed to the display data DN by an overdrive control value ODV corresponding to a refresh rate of 60Hz. It can be understood that the display data DN has a compensation value to drive the source signal to a higher voltage level, thereby expressing sufficient brightness.

[0107] However, if the frame rate increases to 120Hz and the refresh rate increases, the display data DN that is modified to adapt to the refresh rate of a 60Hz frame rate may have difficulty expressing the desired brightness in a shorter cycle.

[0108] As described above with reference to Figures 1 to 4, the embodiments of this disclosure generate an overdrive control value ODV suitable for the current refresh rate based on the change in refresh rate corresponding to the change in frame frequency.

[0109] In detail, the overdrive control value ODV corresponding to a frame frequency of 120Hz can have a greater value than the overdrive control value ODV corresponding to a frame frequency of 60Hz. That is, as shown in Figure 5, display data DO can be overdriven to have a value greater than that of display data DN overdriven at a frame frequency of 60Hz.

[0110] When the display data DO is overdriven to have a larger value as described above, as indicated by LO in Figure 6, the brightness can be fully expressed within the driving cycle of the source signal.

[0111] Therefore, in this disclosure, even when the refresh rate increases, the display data can be provided such that the source signal can be overdriven to a sufficient voltage level in a reduced driving time, and as a result, afterimages formed by insufficient brightness can be prevented.

[0112] Figures 7 and 8 are graphs used to explain the changes in display data as a result of changes from a high frame rate (e.g., 60 Hz) to a low frame rate (e.g., 40 Hz) and the changes in brightness caused by overdrive by embodiments of the present disclosure.

[0113] If the frame rate is reduced to 40Hz and the refresh rate is reduced accordingly, the display data DN that is overdriven to adapt to the 60Hz frame rate refresh rate may have difficulty achieving the desired brightness over a longer period.

[0114] When the display data remains at the display data DN and the overdrive control value ODV corresponding to the 60Hz frame rate, as indicated by LN in Figure 8, the brightness may be overexpressed through the overdrive display data DN.

[0115] As described above with reference to Figures 1 to 4, the embodiments of this disclosure generate an overdrive control value ODV suitable for the current refresh rate based on the change in refresh rate corresponding to the change in frame frequency.

[0116] Specifically, the overdrive control value ODV corresponding to a frame frequency of 40Hz can have a value less than the overdrive control value ODV corresponding to a frame frequency of 60Hz. That is, as shown in Figure 7, display data DO can be overdriven to have a value less than the display data DN overdriven to a frame frequency of 60Hz.

[0117] When the display data DO is overdriven to have a smaller value as described above, as indicated by LO in Figure 8, the brightness can be expressed appropriately and without excessiveness within the driving cycle of the source signal.

[0118] Therefore, in this disclosure, even when the refresh rate decreases, the display data can be provided such that the source signal can be overdriven to an appropriate voltage level without being excessively overdriven during the increased drive time, and as a result, redundant images formed by excessive brightness can be prevented.

[0119] It is evident from the above description that this disclosure can adjust the overdrive of display data in accordance with the current refresh rate, which changes according to the frame frequency.

[0120] Therefore, according to the embodiments of this disclosure, even when the refresh rate increases or decreases, overdrive can be controlled by display data that is compensated in accordance with the current refresh rate, and as a result, the formation of inverted or redundant images on the screen can be prevented.

[0121] 10: Timing Controller 12: Data receiving circuit 14: Data transmission circuit 20: Data Drive 30: Display panel 100: Overdrive circuit 110: Overdrive processing unit 112: Overdrive control unit 120: Difference Inspection Department 130: Frame Buffer 140: Refresh Rate Detection Department 150: Storage Department 160: Control value adjustment section 162: Schmitt trigger circuit DN: Display Data DO: Display data DVC: Difference DW: Display Data FDA: Showing information FDA_P: Showing information FRD: Refresh Rate Value LN: Brightness LO: Brightness LW: Brightness ODV: Overdrive control value RXD: Display data SOUT: Source signal, analogous to source signal TA: Reference and Consultation Form TA1: First, consult the reference table. TA2: Second reference table, reference table TAn: Third, consult the reference sheet. TXD: Display data

Claims

1. A timing controller for a display device, comprising: An overdrive circuit is configured to receive display data for each frame and perform overdrive on the display data. The overdrive circuit stores a plurality of lookup tables, each of which has an overdrive value corresponding to the difference between display data of consecutive frames, and the lookup tables correspond to the refresh rate of the frames. The overdrive circuit selects the overdrive value of the lookup table corresponding to the current refresh rate of the frame as an overdrive control value, and performs overdrive on the display data using the overdrive control value. The overdrive circuit includes an overdrive control unit, which includes: a storage unit configured to store the plurality of lookup tables; and a control value adjustment unit configured to select the lookup table corresponding to the current refresh rate and provide the overdrive value of the selected lookup table as the overdrive control value. A frame buffer is configured to store first display data of the previous frame; and a difference checking unit is configured to receive the first display data of the previous frame and the second display data of the current frame, and output the difference between the first display data and the second display data, wherein the storage unit provides the overdrive value corresponding to the difference in the lookup table corresponding to the current refresh rate to the control value adjustment unit.

2. The timing controller according to claim 1, wherein, The overdrive circuit further includes an overdrive processing unit configured to perform the overdrive on the display data using the overdrive control value.

3. The timing controller according to claim 2, wherein, The overdrive control unit further includes a refresh rate detection unit, configured to detect the current refresh rate using the display data of each frame, and provide a refresh rate value as the detection result.

4. The timing controller according to claim 3, wherein, The storage unit is configured to: store the plurality of lookup tables; store in each of the lookup tables a plurality of overdrive values ​​selectable based on the difference; and select the lookup table by means of the refresh rate value; And select the overdrive value corresponding to the difference in the selected reference table and provide the overdrive value to the control value adjustment unit.

5. The timing controller according to claim 2, wherein, The overdrive control unit outputs the overdrive control value via a Schmitt trigger circuit with hysteresis characteristics.

6. A timing controller for a display device, comprising: An overdrive circuit is configured to receive display data for each frame and perform overdrive on the display data. The overdrive circuit stores a plurality of lookup tables, each of which has an overdrive value corresponding to the difference between display data of consecutive frames, and the lookup tables correspond to the refresh rate of the frames. The overdrive circuit uses an interpolated value of the overdrive value of a lookup table corresponding to a refresh rate adjacent to the current refresh rate as an overdrive control value. The overdrive circuit performs overdrive on the display data using the overdrive control value. The overdrive circuit includes an overdrive control unit, which includes: a storage unit configured to store the plurality of lookup tables; and a control value adjustment unit configured to select a lookup table corresponding to a refresh rate adjacent to the current refresh rate and generate the interpolated value of the overdrive value of the selected lookup table as the overdrive control value. A frame buffer is configured to store first display data of the previous frame; and a difference checking unit is configured to receive the first display data of the previous frame and the second display data of the current frame, and output the difference between the first display data and the second display data, wherein the storage unit provides the overdrive value corresponding to the difference in the selected lookup table to the control value adjustment unit.

7. The timing controller according to claim 6, wherein, The overdrive circuit further includes an overdrive processing unit configured to perform the overdrive on the display data using the overdrive control value.

8. The timing controller according to claim 7, wherein, The overdrive control unit further includes a refresh rate detection unit, configured to detect the current refresh rate using the display data of each frame, and provide a refresh rate value as the detection result.

9. The timing controller according to claim 8, wherein, The storage unit is configured to: store a plurality of the lookup tables; store a plurality of overdrive values ​​selectable based on the difference in each of the lookup tables; and select the lookup table corresponding to the refresh rate adjacent to the current refresh rate by means of the refresh rate value; And select the overdrive value corresponding to the difference in the selected lookup table, and provide the overdrive value to the control value adjustment unit.

10. The timing controller according to claim 7, wherein, The overdrive control unit outputs the overdrive control value via a Schmitt trigger circuit with hysteresis characteristics.

11. A timing controller for a display device, comprising: An overdrive circuit is configured to receive display data for each frame and perform overdrive on the display data, wherein the overdrive circuit stores a lookup table corresponding to a reference refresh rate, the lookup table having overdrive values ​​corresponding to the differences in display data of consecutive frames, wherein the overdrive circuit generates an overdrive control value by calculating a weight corresponding to the current refresh rate of the frame and the overdrive value corresponding to the difference, and wherein the overdrive circuit performs the overdrive on the display data using the overdrive control value.

12. The timing controller according to claim 11, wherein, The overdrive circuit includes: an overdrive control unit configured to store the lookup table, detect the current refresh rate of the frame, and generate the overdrive control value by calculating the weight corresponding to the current refresh rate and the overdrive value corresponding to the difference; and an overdrive processing unit configured to perform the overdrive on the display data using the overdrive control value.

13. The timing controller according to claim 12, wherein, The overdrive control unit includes: a storage unit configured to store the lookup table; a refresh rate detection unit configured to detect the current refresh rate using the display data of each frame and provide a refresh rate value as a detection result; and a control value adjustment unit configured to use the refresh rate value as the weight and provide the overdrive control value by calculating the weight and the overdrive value corresponding to the difference.

14. The timing controller according to claim 13, wherein, The overdrive control unit further includes: a frame buffer configured to store first display data of the previous frame; and a difference checking unit configured to receive the first display data of the previous frame and the second display data of the current frame, and output the difference between the first display data and the second display data, wherein the storage unit provides the overdrive value corresponding to the difference to the control value adjustment unit.

15. A timing controller for a display device, comprising: The data receiving circuit is configured to receive display data in which the refresh rate of a frame changes; An overdrive control unit is configured to receive the display data received via the data receiving circuit, detect the current refresh rate of the frame, check the difference between the first display data of the current frame and the second display data of the previous frame, and provide an overdrive control value that changes according to the current refresh rate and the difference; an overdrive processing unit is configured to perform overdrive on the display data received via the data receiving circuit and control the overdrive voltage level by means of the overdrive control value; and a data transmission circuit is configured to transmit the overdrive display data in the overdrive processing unit.

16. The timing controller according to claim 15, wherein, The overdrive control unit is configured to: store a plurality of lookup tables, each of the plurality of lookup tables having an overdrive value corresponding to the difference, and the lookup tables corresponding to the refresh rate; The difference between the first display data and the second display data is generated; a refresh rate value is generated by detecting the current refresh rate via the display data; Select the lookup table corresponding to the refresh rate value; select the overdrive value corresponding to the difference in the selected lookup table; and provide the selected overdrive value as the overdrive control value.

17. The timing controller according to claim 15, wherein, The overdrive control unit is configured to: store a plurality of lookup tables, each of the plurality of lookup tables having an overdrive value corresponding to the difference, and the lookup tables corresponding to the refresh rate; The difference between the first display data and the second display data is generated; a refresh rate value is generated by detecting the current refresh rate via the display data; The system selects a lookup table adjacent to the current refresh rate based on the refresh rate value; selects an overdrive value corresponding to the difference in the selected lookup table; generates an interpolated value for the selected overdrive value; and provides the interpolated value as the overdrive control value.

18. The timing controller according to claim 15, wherein, The overdrive control unit is configured to: store a lookup table corresponding to a reference refresh rate, the lookup table having an overdrive value corresponding to the difference; generate the difference between the first display data and the second display data; generate a refresh rate value by detecting the current refresh rate via the display data; select an overdrive value corresponding to the difference; and use the refresh rate value as a weight, and provide the overdrive control value by calculating the weight and the overdrive value corresponding to the difference.

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