Gamma reference voltage generator and display device including the same

Abstract

A gamma reference voltage generator and a display apparatus including the same are provided. The gamma reference voltage generator includes a first resistor string, a black voltage setter, a selector, and a second resistor string. The first resistor string receives a first reference voltage and a second reference voltage. The black voltage setter extracts a plurality of black candidate voltages from the first resistor string. The selector selects one of the black candidate voltages as a black gamma voltage based on a selection signal. The second resistor string receives a first voltage corresponding to the one of the black candidate voltages and a second voltage extracted from the first resistor string. In addition, the gamma reference voltage generator includes a gamma voltage setter that extracts a plurality of gamma voltages from the second resistor string.

Description

Technical Field

[0001] One or more embodiments described herein relate to a gamma reference voltage generator and a display device including the gamma reference voltage generator. Background Technology

[0002] Some displays use gamma reference voltage generators to perform grayscale correction on moving image data. For example, when a pixel's grayscale value changes from black to white, the brightness corresponding to the white grayscale value cannot reach the desired brightness due to image overlap or color sticking. Furthermore, when outputting monochrome low-grayscale images, current leakage may occur between the channels of the color pixels. This can cause distortion in monochrome low-grayscale images, or may render the image unreadable altogether. Summary of the Invention

[0003] One or more embodiments described herein provide a gamma reference voltage generator that selectively generates black grayscale voltage, thereby improving the display quality of a display panel. These or other embodiments provide a display device including a gamma reference voltage generator that corresponds to the aforementioned gamma reference voltage generator.

[0004] According to one or more embodiments, a gamma reference voltage generator includes: a first resistor string configured to receive a first reference voltage and a second reference voltage; a plurality of black voltage setters configured to extract a plurality of black candidate voltages from the first resistor string; a selector configured to select one of the black candidate voltages as a black gamma voltage based on a selection signal generated based on a black level command signal applied from a host; a second resistor string configured to receive the first voltage and the second voltage, the first voltage corresponding to one of the black candidate voltages, and the second voltage extracted from the first resistor string; and a plurality of gamma voltage setters configured to extract a plurality of gamma voltages from the second resistor string.

[0005] According to one or more embodiments, a display device includes: a display panel configured to display an image; a drive controller configured to receive input image data and convert the input image data into a data signal; a gamma reference voltage generator configured to generate a gamma voltage corresponding to the data signal; and a data driver configured to output the gamma voltage to the display panel based on the data signal. The gamma reference voltage generator selects one of a plurality of black candidate voltages as the black gamma voltage to be output to the display panel based on a selection signal. The selection signal is based on a black level command signal from a host computer. Attached Figure Description

[0006] The above and other features of the present invention will become more apparent from a detailed description of its embodiments with reference to the accompanying drawings, in which:

[0007] Figure 1 The figure illustrates an embodiment of the display device;

[0008] Figure 2 The illustration shows an embodiment of displaying an image on a display panel;

[0009] Figure 3 The figure illustrates an embodiment of a gamma reference voltage generator;

[0010] Figure 4 The figure illustrates an embodiment of the first resistor string;

[0011] Figure 5 The figure illustrates an embodiment of selecting a signal generator;

[0012] Figure 6 The figure illustrates an embodiment of selecting a signal generator;

[0013] Figure 7 The illustration shows an embodiment of displaying an image on a display panel;

[0014] Figure 8 The figure illustrates an embodiment of a gamma reference voltage generator;

[0015] Figure 9 The illustration shows an embodiment of displaying an image on a display panel; and

[0016] Figure 10 The figure illustrates an embodiment of a gamma reference voltage generator. Detailed Implementation

[0017] The concept of the invention will be explained in detail below with reference to the accompanying drawings.

[0018] Figure 1 This is a block diagram illustrating an embodiment of a display device including a display panel 100 and a display panel driver. The display panel driver may include, for example, a drive controller 200, a gate driver 300, a gamma reference voltage generator 400, and a data driver 500. In one embodiment, the display device may further include a host 600, or the host 600 may be an external component coupled to the display device.

[0019] The display panel 100 has a display area for displaying images and a peripheral area adjacent to the display area. The display panel 100 includes multiple gate lines GL, multiple data lines DL, and multiple pixels P connected to the gate lines GL and the data lines DL. The gate lines GL extend in a first direction D1, and the data lines DL extend in a second direction D2 that intersects the first direction D1.

[0020] The drive controller 200 receives input image data IMG and input control signal CONT from the host 600. The input image data IMG may include color image data, such as red, green, and blue image data. In one embodiment, the input image data IMG may also include white image data. In another embodiment, the input image data IMG may include magenta, yellow, and cyan image data, or include image data containing another combination of these colors. The input control signal CONT may include a master clock signal and a data enable signal, and in some embodiments may further include a vertical synchronization signal and a horizontal synchronization signal. In this embodiment, the input control signal CONT output by the host 600 to the drive controller 200 may further include a black level command signal BLC (e.g., for setting the level of the black gamma voltage). Figure 2 (as shown in the image).

[0021] The drive controller 200 generates a first control signal CONT1, a second control signal CONT2, a third control signal CONT3, and a data signal DATA based on the input image data IMG and the input control signal CONT. The drive controller 200 can generate the first control signal CONT1 for controlling the operation of the gate driver 300 based on the input control signal CONT, and can output the first control signal CONT1 to the gate driver 300. The first control signal CONT1 may include a vertical start signal and a gate clock signal.

[0022] The drive controller 200 can generate a second control signal CONT2 for controlling the operation of the data driver 500 based on the input control signal CONT, and can output the second control signal CONT2 to the data driver 500. The second control signal CONT2 may include a horizontal start signal and a load signal.

[0023] The drive controller 200 can generate a data signal DATA based on the input image data IMG, and can output the data signal DATA to the data driver 500.

[0024] The drive controller 200 can generate a third control signal CONT3 based on the input control signal CONT for controlling the operation of the gamma reference voltage generator 400. The drive controller 200 can output the third control signal CONT3 to the gamma reference voltage generator 400.

[0025] The gate driver 300 can generate a gate signal for driving the gate line GL in response to a first control signal CONT1 from the drive controller 200. The gate driver 300 can output the gate signal to the gate line GL. For example, the gate driver 300 can sequentially output the gate signal to the gate line GL. In one embodiment, the gate driver 300 can be mounted in or coupled to the peripheral area of ​​the display panel 100. For example, the gate driver 300 can be integrated into the peripheral area of ​​the display panel 100.

[0026] The gamma reference voltage generator 400 can generate a gamma reference voltage VGREF in response to a third control signal CONT3 from the drive controller 200. The gamma reference voltage generator 400 can provide the gamma reference voltage VGREF to the data driver 500. The gamma reference voltage VGREF can have a value corresponding to the level of the data signal DATA. In embodiments, the gamma reference voltage generator 400 can be arranged in or coupled to the drive controller 200, or it can be arranged in or coupled to the data driver 500.

[0027] The data driver 500 can receive a second control signal CONT2 and a data signal DATA from the drive controller 200, as well as a gamma reference voltage VGREF from the gamma reference voltage generator 400. The data driver 500 uses the gamma reference voltage VGREF to convert the data signal DATA into an analog data voltage. The data driver 500 can output the analog data voltage to the data line DL.

[0028] Figure 2 It is shown in the diagram Figure 1 A block diagram illustrating an embodiment of displaying an image on a display panel 100. (Refer to...) Figure 1 and Figure 2 The display panel 100 displays an image under the control of the drive controller 200. For example, the drive controller 200 can receive input image data IMG and convert the input image data IMG into a data signal DATA. The gamma reference voltage generator 400 can generate a gamma voltage corresponding to the data signal DATA, and the data driver 500 can output the gamma voltage to the display panel 100 based on the data signal DATA.

[0029] The black gamma voltage output to the display panel 100 can be selected from a plurality of black candidate voltages based on a selection signal (e.g., a black level command signal BLC). In one embodiment, the host 600 can output input image data IMG and the black level command signal BLC to the drive controller 200. The input image data IMG can include grayscale values ​​within a predetermined range (e.g., between 0 and 255). In another embodiment, the grayscale values ​​can be within different ranges.

[0030] When there are four black candidate voltages, the black level command signal BLC can have four values: 0, 1, 2, and 3. According to one embodiment, these values ​​can be selected as follows: When the black level command signal BLC has a value of 0, the first black candidate voltage can be selected as the black gamma voltage. When the black level command signal BLC has a value of 1, the second black candidate voltage can be selected as the black gamma voltage. When the black level command signal BLC has a value of 2, the third black candidate voltage can be selected as the black gamma voltage. When the black level command signal BLC has a value of 3, the fourth black candidate voltage can be selected as the black gamma voltage.

[0031] The drive controller 200 may include a lookup table (LUT) storing output data OUTPUT corresponding to the input grayscale value INPUT of the input image data IMG. In this embodiment, the lookup table LUT may not store the output value for the grayscale value 0, but may store the output values ​​for all grayscale values ​​other than 0, other grayscale values, or predetermined grayscale values. The grayscale value of 0 in the input image data IMG may correspond to a black grayscale value. In this case, four black candidate voltage setting values ​​BL1, BL2, BL3, and BL4 may be input to the gamma reference voltage generator 400. (Refer to...) Figure 3 and Figure 4 Explain the embodiments corresponding to the structure and operation of the gamma reference voltage generator 400.

[0032] Figure 3 It is shown in the figure. Figure 1 Circuit diagram of an embodiment of the gamma reference voltage generator 400. Figure 4 It is shown in the figure. Figure 3 The circuit diagram of an embodiment of the first resistor string RS1.

[0033] Reference Figures 1 to 4The gamma reference voltage generator 400 includes a first resistor string RS1, multiple black voltage setters VSB1, VSB2, VSB3 and VSB4, a selector SL1, a second resistor string RS2, and multiple gamma voltage setters VS1, VS2, ..., VS255. A high reference voltage VRH and a low reference voltage VRL can be coupled to the first resistor string RS1. The first resistor string RS1 may include multiple resistors R1 to RN connected in series, and output terminals T0 to TN can be arranged at corresponding nodes of the first resistor string RS1.

[0034] The first output terminal T0 can be located at the input terminal of the high reference voltage VRH. The second output terminal T1 is coupled between the first resistor R1 and the second resistor R2. The third output terminal T2 is coupled between the second resistor R2 and the third resistor R3. The fourth output terminal T3 is coupled between the third resistor R3 and the fourth resistor R4. The Nth output terminal TN-1 can be coupled between the (N-1)th resistor RN-1 and the Nth resistor RN. The N+1th output terminal TN can be located at the input terminal of the low reference voltage VRL.

[0035] Black voltage setters VSB1, VSB2, VSB3, and VSB4 can extract a corresponding black candidate voltage from the first resistor string RS1. For example, a first black candidate voltage setting value BL1 can be applied to the first black voltage setter VSB1. A specific voltage between the high reference voltage VRH and the low reference voltage VRL can be extracted from the first resistor string RS1 as the first black candidate voltage based on the first black candidate voltage setting value BL1. The first black candidate voltage setting value BL1 can determine that the first black candidate voltage will be extracted from a specific output terminal from the first output terminal T0 to the (N+1)th output terminal TN of the first resistor string RS1.

[0036] The second black candidate voltage setting value BL2 can be applied to the second black voltage setter VSB2. The specific voltage between the high reference voltage VRH and the low reference voltage VRL can be extracted from the first resistor string RS1 based on the second black candidate voltage setting value BL2 as the second black candidate voltage.

[0037] The third black candidate voltage setting value BL3 can be applied to the third black voltage setter VSB3. The specific voltage between the high reference voltage VRH and the low reference voltage VRL can be extracted from the first resistor string RS1 based on the third black candidate voltage setting value BL3 as the third black candidate voltage.

[0038] The fourth black candidate voltage setting value BL4 can be applied to the fourth black voltage setter VSB4. The specific voltage between the high reference voltage VRH and the low reference voltage VRL can be extracted from the first resistor string RS1 based on the fourth black candidate voltage setting value BL4 as the fourth black candidate voltage.

[0039] In one embodiment, the first black candidate voltage may be greater than the second black candidate voltage, the second black candidate voltage may be greater than the third black candidate voltage, and the third black candidate voltage may be greater than the fourth black candidate voltage.

[0040] Selector SL1 can select one of the black candidate voltages as the black gamma voltage V0 based on the selection signal BS. The selection signal BS can be generated, for example, based on the black level command signal BLC.

[0041] In this embodiment, selector SL1 may include a decoder (not shown) that outputs one of the black candidate voltages in response to the selection signal BS. For example, when the selection signal BS represents a first black candidate voltage, selector SL1 outputs the first black candidate voltage as the black gamma voltage V0. When the selection signal BS represents a second black candidate voltage, selector SL1 outputs the second black candidate voltage as the black gamma voltage V0. When the selection signal BS represents a third black candidate voltage, selector SL1 outputs the third black candidate voltage as the black gamma voltage V0. When the selection signal BS represents a fourth black candidate voltage, selector SL1 outputs the fourth black candidate voltage as the black gamma voltage V0.

[0042] The gamma reference voltage generator 400 may further include a black gamma voltage output amplifier AMP0 connected to the decoder.

[0043] A first voltage and a second voltage can be applied to a second resistor string RS2. The first voltage can be one of the black candidate voltages (e.g., the voltages corresponding to the first black voltage setter VSB1 through the fourth black voltage setter VSB4). In one embodiment, the first voltage can be the minimum voltage among the black candidate voltages (e.g., the voltage corresponding to the fourth black voltage setter VSB4). The second voltage can be extracted from the first resistor string RS1.

[0044] The second voltage can be extracted from the first resistor string RS1 by the second voltage setter VSB.

[0045] The gamma reference voltage generator 400 may further include a first amplifier AMPA and a second amplifier AMPB. The first amplifier AMPA outputs a first voltage to a second resistor string RS2. The second amplifier AMPB outputs a second voltage to the second resistor string RS2. The first amplifier AMPA... Figure 3The first amplifier AMPA is connected to the fourth black voltage setter VSB4, but in another embodiment, the connection can be made in a different manner. For example, the first amplifier AMPA can be connected to any one of the first black voltage setters VSB1 through the fourth black voltage setter VSB4.

[0046] Gamma voltage setters VS1, VS2, ..., VS255 can extract gamma voltages V1, V2, ..., V255. Gamma reference voltage generator 400 may include gamma voltage setters VS1, VS2, ..., VS255 that can be respectively connected to gamma voltage output amplifiers AMP1, AMP2, ..., AMP255. In one embodiment, gamma reference voltage generator 400 includes gamma voltage setters VS1, VS2, ..., VS255 and gamma voltage output amplifiers AMP1, AMP2, ..., AMP255 corresponding to all of the grayscale values ​​0 to 255 of the input image data IMG. In another embodiment, gamma reference voltage generator 400 may include gamma voltage setters and gamma voltage output amplifiers corresponding to some (less than all) of the grayscale values ​​of the input image data IMG.

[0047] Furthermore, the gamma reference voltage generator 400 may include gamma reference voltage generators for different color image data. For example, the gamma reference voltage generator 400 may include a red gamma reference voltage generator corresponding to red input image data, a green gamma reference voltage generator corresponding to green input image data, and a blue gamma reference voltage generator corresponding to blue input image data.

[0048] The gamma reference voltage generator 400 may further include multiple output resistors RX, ..., RY connected between the gamma voltage output amplifiers AMP1, AMP2, ..., AMP255.

[0049] Similar to the first resistor string RS1, the second resistor string RS2 may include resistors connected in series and output terminals arranged between the resistors. For example, a specific voltage between a first voltage and a second voltage can be extracted from the second resistor string RS2 as a first gamma voltage V1 based on a first gamma voltage setting value applied to the first gamma voltage setter VS1. Similarly, a specific voltage between the first voltage and the second voltage can be extracted from the second resistor string RS2 as a second gamma voltage V2 based on a second gamma voltage setting value applied to the second gamma voltage setter VS2.

[0050] The first gamma voltage setting value could be, for example, in... Figure 2 The output value for the grayscale value of 1 in the lookup table (LUT) is 1100. The second gamma voltage setting value can be, for example, in... Figure 2 The output value for the grayscale value of 2 in the lookup table LUT is 1200.

[0051] Figure 5 The diagram illustrates the generation applied to Figure 3 A block diagram of an embodiment of the selection signal generator BS of the gamma reference voltage generator 400.

[0052] Reference Figures 1 to 5 The selection signal generator may include a first non-volatile memory (OTP) that stores the black selection enable signal (EN) from the host 600, the set black value (SET BLACK), and the module black value (MODULE BLACK) set by the drive controller 200. In this embodiment, the first non-volatile memory (OTP) may be a one-time programmable memory.

[0053] The selection signal BS can be determined as one of two values ​​output in response to the black selection enable signal EN: a set black value (SETBLACK) and a module black value (MODULE BLACK). For example, when the black selection enable signal EN has a first (e.g., invalid) value, the operation of selecting the black gamma voltage can be disabled. When the black selection enable signal EN has an invalid value, the selection signal BS can be determined as the module black value (MODULE BLACK). The module black value (MODULE BLACK) can be set by the manufacturer, for example, during the inspection operation of the display panel 100 and can be stored in the drive controller 200.

[0054] If the second black candidate voltage (among the first to fourth black candidate voltages) is determined by the module black value MODULEBLACK during the check operation to be, for example, the optimal black gamma voltage, then when the black selection enable signal EN has an invalid value, the selection signal BS can output a value for selecting the second black candidate voltage (from the first to fourth black candidate voltages) as the black gamma voltage V0 (e.g., outputting 1 among 0, 1, 2 and 3).

[0055] When, for example, the black selection enable signal EN has a second (e.g., active) value, the operation of selecting the black gamma voltage can be activated, and the black value SET BLACK can be output as the selection signal BS. When the black value SET BLACK indicates that the third black candidate voltage (from the first to the fourth black candidate voltages) is used as the black gamma voltage, the selection signal BS can output the value used to select the third black candidate voltage (from the first to the fourth black candidate voltages) as the black gamma voltage V0, for example, outputting 2 among 0, 1, 2, and 3. The black value SET BLACK can also be the black level command signal BLC.

[0056] According to this embodiment, the black grayscale voltage of the display device can be appropriately selected using the selector SL1 of the gamma reference voltage generator 400. In one embodiment, the black grayscale voltage of the display device can be appropriately selected such that first frame response (FFR) problems can be mitigated or prevented (e.g., where the brightness corresponding to the white grayscale value cannot reach the desired brightness in the first frame when the value changes from black to white). Furthermore, leakage current problems can be mitigated or prevented (e.g., where current leakage between the channels of color pixels (e.g., red, green, and blue pixels) causes the display panel to be unable to display monochrome low grayscale images). Therefore, the display quality of the display panel 100 can be improved.

[0057] Figure 6 This is a block diagram illustrating an embodiment of a selection signal generator for a display device. Besides the selection signal generator, this embodiment also includes a gamma reference voltage generator and a display device. Figures 1 to 5 The gamma reference voltage generator and display device in the embodiment are essentially the same. Therefore, the same reference numerals will be used to refer to the same components as those in the embodiment. Figures 1 to 5 The same or similar components described in the previous embodiments.

[0058] Reference Figures 1 to 4 as well as Figure 6 The display device includes a display panel 100 and a display panel driver. The display panel driver includes a drive controller 200, a gate driver 300, a gamma reference voltage generator 400, and a data driver 500. The display device may further include a host 600, or the host 600 may be an external component coupled to the display device.

[0059] The black gamma voltage output to the display panel 100 can be selected from multiple black candidate voltages based on a selection signal BS. The selection signal BS can be output from a selection signal generator, which may include a first non-volatile memory FL and a second non-volatile memory OTP. The first non-volatile memory FL can output a black selection enable signal EN and a setting black value SET BLACK. The second non-volatile memory OTP can store the module black value MODULE BLACK set by the drive controller 200. In this embodiment, the first non-volatile memory FL may be flash memory, and the second non-volatile memory OTP may be a one-time programmable memory.

[0060] The selection signal BS can be determined as either the set black value (SET BLACK) or the module black value (MODULE BLACK) in response to the black selection enable signal EN. For example, when the black selection enable signal EN has an invalid value, the operation of selecting the black gamma voltage can be disabled. When the black selection enable signal EN has an invalid value, the selection signal BS can be determined as the module black value (MODULE BLACK). For example, when the black selection enable signal EN has an valid value, the operation of selecting the black gamma voltage can be activated, and the set black value (SET BLACK) can be output as the selection signal BS.

[0061] According to this embodiment, the black grayscale voltage of the display device can be appropriately selected using the selector SL1 of the gamma reference voltage generator 400. The black grayscale voltage of the display device is appropriately selected such that first frame response (FFR) problems can be mitigated or prevented (e.g., where the brightness corresponding to the white grayscale value cannot reach the desired brightness in the first frame when the black grayscale value changes to a white grayscale value). Furthermore, leakage current problems can be mitigated or prevented (e.g., where current leakage between the channels of color pixels (e.g., red, green, and blue pixels) causes the display panel to be unable to display a monochrome low grayscale image). Therefore, the display quality of the display panel 100 can be improved.

[0062] Figure 7 This is a block diagram illustrating an embodiment of displaying an image on a display panel 100, and Figure 8 It is shown in the figure. Figure 7 A circuit diagram of an embodiment of the gamma reference voltage generator 400A. Apart from the structure and operation of the selector of the gamma reference voltage generator, the gamma reference voltage generator and display device according to this embodiment can be used with… Figures 1 to 5 The gamma reference voltage generator and display device in the embodiment are essentially the same. Therefore, the same reference numerals will be used to refer to the same components as those in the embodiment. Figures 1 to 5 The same or similar components described in the previous embodiments.

[0063] Reference Figure 1 , Figure 4 , Figure 5 , Figure 7 and Figure 8 The display device includes a display panel 100 and a display panel driver. The display panel driver includes a drive controller 200, a gate driver 300, a gamma reference voltage generator 400A, and a data driver 500. The display device may further include a host 600, or the host 600 may be an external component coupled to the display device.

[0064] Display panel 100 displays images based on image data. Drive controller 200 receives input image data IMG and converts it into a data signal DATA. Gamma reference voltage generator 400A generates a gamma voltage corresponding to the data signal DATA, and data driver 500 outputs the gamma voltage to display panel 100 based on the data signal DATA.

[0065] The black gamma voltage output to display panel 100 can be selected from multiple black candidate voltages based on a selection signal (e.g., black level command signal BLC). Host 600 can output input image data IMG and the black level command signal BLC to drive controller 200. For example, the input image data IMG can include grayscale values ​​within the grayscale range of display panel 100 (e.g., between 0 and 255). In another embodiment, the grayscale range can be different ranges.

[0066] In this embodiment, the number of black candidate reference voltages can be two, and the black candidate voltage can be determined as the level between the two black candidate reference voltages. Therefore, in this example, the number of black candidate voltages can be much larger than... Figure 2 and Figure 3 The number of black candidate voltages in the embodiments. For illustrative purposes, Figure 7 The diagram illustrates the case where there are 100 black candidate voltages. Therefore, the black level command signal BLC can have one hundred values ​​ranging from 0 to 99.

[0067] The drive controller 200 may include a lookup table (LUT) that stores output data OUTPUT corresponding to the input grayscale values ​​INPUT of the input image data IMG. In this embodiment, the lookup table LUT may not store output values ​​for grayscale values ​​of 0, but may store all or a portion of the output values ​​for grayscale values ​​other than 0. The grayscale value of 0 in the input image data IMG may correspond to a black grayscale value.

[0068] The Gamma Reference Voltage Generator 400A can receive two black candidate voltage settings, BL1 and BL2. The Gamma Reference Voltage Generator 400A may include a first resistor string RS1, multiple black voltage setters VSB1 and VSB2, selectors RSB and VSB3, a second resistor string RS2, and multiple gamma voltage setters VS1, VS2, ..., VS255.

[0069] In this embodiment, black voltage setters VSB1 and VSB2 can extract two black candidate reference voltages from the first resistor string RS1. For example, a first black candidate voltage setting value BL1 can be applied to the first black voltage setter VSB1. The specific voltage between the high reference voltage VRH and the low reference voltage VRL can be extracted from the first resistor string RS1 based on the first black candidate voltage setting value BL1 as the first black candidate reference voltage. A second black candidate voltage setting value BL2 can be applied to the second black voltage setter VSB2. The specific voltage between the high reference voltage VRH and the low reference voltage VRL can be extracted from the first resistor string RS1 based on the second black candidate voltage setting value BL2 as the second black candidate reference voltage.

[0070] Selectors RSB and VSB3 may include a third resistor string RSB for receiving a first black candidate reference voltage and a second black candidate reference voltage, and a final black voltage setter VSB3 for extracting the black gamma voltage from the third resistor string RSB. The final black voltage setter VSB3 can extract the final black gamma voltage V0.

[0071] The Gamma Reference Voltage Generator 400A may further include a Black Gamma Voltage Output Amplifier AMP0 connected to the final Black Voltage Setter VSB3.

[0072] A first voltage and a second voltage can be applied to a second resistor string RS2. The first voltage can be one of the black candidate reference voltages (e.g., the voltages corresponding to the first black voltage setter VSB1 and the second black voltage setter VSB2). For example, the first voltage can be the minimum voltage among the black candidate reference voltages (the voltage corresponding to the second black voltage setter VSB2). The second voltage can be extracted from the first resistor string RS1. The second voltage can be extracted from the first resistor string RS1 by the second voltage setter VSB.

[0073] The gamma reference voltage generator 400A may further include a first amplifier AMPA and a second amplifier AMPB. The first amplifier AMPA outputs a first voltage to a second resistor string RS2. The second amplifier AMPB outputs a second voltage to the second resistor string RS2. Figure 8 In one embodiment, the first amplifier AMPA is connected to the second black voltage setter VSB2, but in another embodiment, the first amplifier AMPA can be connected to the first black voltage setter VSB1.

[0074] According to this embodiment, the black grayscale voltage of the display device can be appropriately selected using selectors RSB and VSB3 of the gamma reference voltage generator 400A. In one embodiment, the black grayscale voltage of the display device can be appropriately selected to mitigate or prevent, for example, an FFR problem where the brightness corresponding to the white grayscale value cannot reach the desired brightness in the first frame where the grayscale value changes from black to white. Additionally or alternatively, leakage current problems can be mitigated or prevented (e.g., where current leakage between the channels of color pixels (e.g., red pixels, green pixels, blue pixels) causes the display panel to be unable to display a monochrome low grayscale image). Therefore, the display quality of the display panel 100 can be improved.

[0075] Figure 9 This is a block diagram illustrating an embodiment of displaying an image on a display panel 100, and Figure 10 It is shown in the figure. Figure 9 A circuit diagram of an embodiment of the gamma reference voltage generator 400B. Apart from the structure and operation of the selector of the gamma reference voltage generator, the gamma reference voltage generator and display device according to this embodiment can be used with… Figures 1 to 5 The gamma reference voltage generator and display device in the embodiment are essentially the same. Therefore, the same reference numerals will be used to refer to the same... Figures 1 to 5 The same or similar components described in the embodiments.

[0076] Reference Figure 1 , Figure 4 , Figure 5 , Figure 9 and Figure 10 The display device includes a display panel 100 and a display panel driver. The display panel driver includes a drive controller 200, a gate driver 300, a gamma reference voltage generator 400B, and a data driver 500. The display device may further include a host 600, or the host 600 may be an external component coupled to the display device. The display panel 100 displays an image.

[0077] The drive controller 200 receives input image data IMG and converts it into a data signal DATA. A gamma reference voltage generator 400B generates a gamma voltage corresponding to the data signal DATA. The data driver 500 outputs the gamma voltage to the display panel 100 based on the data signal DATA.

[0078] The black gamma voltage output to display panel 100 can be selected from multiple black candidate voltages based on a selection signal (e.g., black level command signal BLC). Host 600 can output input image data IMG and the black level command signal BLC to drive controller 200. For example, the input image data IMG may include grayscale values ​​within a predetermined grayscale range of display panel 100 (e.g., between 0 and 255). In another embodiment, this range may be different.

[0079] In one example, the number of black candidate voltages is four. In this case, the black level command signal BLC can have four values: 0, 1, 2, and 3. When the black level command signal BLC has a value of 0, the first black candidate voltage can be selected as the black gamma voltage V0. When the black level command signal BLC has a value of 1, the second black candidate voltage can be selected as the black gamma voltage V0. When the black level command signal BLC has a value of 2, the third black candidate voltage can be selected as the black gamma voltage V0. When the black level command signal BLC has a value of 3, the fourth black candidate voltage can be selected as the black gamma voltage V0. In another embodiment, the number of black candidate voltages may be different from four.

[0080] The drive controller 200 may include a lookup table (LUTB) storing output data (OUTPUT) corresponding to the input grayscale values ​​(INPUT) of the input image data (IMG). In this embodiment, the lookup table (LUTB) may store multiple candidate data (e.g., 800, 900, 1000, and 1050) corresponding to the grayscale value 0. The lookup table (LUTB) may output one of the candidate data (e.g., 800, 900, 1000, and 1050) as a black data signal to the gamma reference voltage generator 400B based on the selection signal (BS).

[0081] In this embodiment, the gamma reference voltage generator 400B may not include an additional selector and may output a black gamma voltage corresponding to a black data signal (e.g., one of 800, 900, 1000, and 1050).

[0082] The gamma reference voltage generator 400B may include a first resistor string RS1, a second resistor string RS2, a black gamma voltage generator VSA that sets the black gamma voltage V0, a ​​black gamma voltage output amplifier AMP0 that outputs the black gamma voltage V0, a ​​second voltage setter VSB that extracts the second voltage from the first resistor string RS1, and a second voltage amplifier AMPB that outputs the second voltage to the second resistor string RS2.

[0083] The gamma reference voltage generator 400B may further include multiple gamma voltage setters VS1, VS2, ..., VS255 that extract gamma voltages V1, V2, ..., V255 from the second resistor string RS2. The gamma reference voltage generator 400B may further include multiple gamma voltage output amplifiers AMP1, AMP2, ..., AMP255 that are respectively connected to the gamma voltage setters VS1, VS2, ..., VS255.

[0084] According to this embodiment, the black grayscale voltage of the display device can be appropriately selected using the lookup table (LUTB) of the drive controller 200. The black grayscale voltage of the display device can be appropriately selected to mitigate or prevent FFR problems (e.g., where the brightness corresponding to the white grayscale value cannot reach the desired brightness in the first frame when the grayscale value changes from black to white). Furthermore, leakage current problems can be mitigated or prevented (e.g., where the display panel cannot display a monochrome low grayscale image due to current leakage between the channels of color pixels (e.g., red, green, and blue pixels). Therefore, the display quality of the display panel 100 can be improved.

[0085] The methods, processes, and / or operations described herein may be implemented by code or instructions to be executed by a computer, processor, controller, or other signal processing device. The computer, processor, controller, or other signal processing device may be any of those described herein or any other element besides those described herein. Because the algorithms underlying the methods (or the operation of the computer, processor, controller, or other signal processing device) are described in detail, the code or instructions used to implement the operations of the method embodiments can transform a computer, processor, controller, or other signal processing device into a dedicated processor for executing the methods described herein.

[0086] In addition, another embodiment may include a computer-readable medium for storing the above-described code or instructions, such as a non-transitory computer-readable medium. The computer-readable medium may be volatile or non-volatile memory or other storage device that may be removably or permanently coupled to a computer, processor, controller, or other signal processing device that will execute the code or instructions for carrying out the operations of the method or apparatus embodiments described herein.

[0087] The controllers, processors, selectors, setters, devices, modules, units, multiplexers, generators, logic, interfaces, decoders, drivers, and other signal generation and signal processing features disclosed herein can be implemented, for example, with non-transitory logic that may include hardware, software, or both. When implemented at least partially in hardware, the controllers, processors, devices, modules, units, selectors, setters, multiplexers, generators, logic, interfaces, decoders, drivers, and other signal generation and signal processing features can be, for example, any of a variety of integrated circuits including, but not limited to, application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), combinations of logic gates, systems-on-a-chip (SoCs), microprocessors, or other types of processing or control circuitry.

[0088] When implemented at least partially in software, controllers, processors, devices, modules, units, multiplexers, generators, logic, interfaces, setters, selectors, decoders, drivers, and other signal generation and signal processing features may include, for example, memory or other storage devices for storing code or instructions to be executed by, for example, a computer, processor, microprocessor, controller, or other signal processing device. The computer, processor, microprocessor, controller, or other signal processing device may be any of those described herein or any other element besides those described herein. Because the algorithms underlying the formation of the method (or the operation of the computer, processor, microprocessor, controller, or other signal processing device) are described in detail, the code or instructions for implementing the operations of the method embodiments can transform a computer, processor, controller, or other signal processing device into a dedicated processor for carrying out the methods described herein.

[0089] The foregoing is a description of the inventive concept and should not be construed as limiting it. Although several embodiments of the inventive concept have been described, those skilled in the art will readily understand that many modifications are possible in the embodiments without substantially departing from the novel teachings and advantages of the inventive concept. Therefore, all such modifications are intended to be included within the scope of the inventive concept as defined in the claims. In the claims, the clause "means plus function" is intended to cover the structure described herein for implementing the said function, and includes not only structural equivalents but also equivalent structures. Therefore, it should be understood that the foregoing is a description of the inventive concept and should not be construed as limiting it to the specific embodiments disclosed, and modifications to the disclosed embodiments and other embodiments are intended to be included within the scope of the appended claims. The inventive concept is defined by the appended claims and their equivalents. Embodiments may be combined to form further embodiments.

Claims

1. A gamma reference voltage generator, comprising: The first resistor string is configured to receive a first reference voltage and a second reference voltage; Multiple black voltage setters are configured to extract multiple black candidate voltages from the first resistor string; The selector is configured to select one of the black candidate voltages as the black gamma voltage based on a selection signal generated based on a black level command signal applied from the host. The second resistor string is configured to receive a first voltage and a second voltage, the first voltage being extracted from the first resistor string, corresponding to one of the black candidate voltages, and transmitted from one of the black voltage setters to the second resistor string without being transmitted through the selector, and the second voltage being extracted from the first resistor string. as well as Multiple gamma voltage setters are configured to extract multiple gamma voltages from the second resistor string.

2. The gamma reference voltage generator according to claim 1, wherein, The selector includes a decoder configured to output one of the black candidate voltages in response to the selection signal.

3. The gamma reference voltage generator according to claim 2, further comprising: A black gamma voltage output amplifier is connected to the decoder.

4. The gamma reference voltage generator according to claim 1, wherein, The first voltage is the minimum voltage among the black candidate voltages.

5. The gamma reference voltage generator according to any one of claims 1 to 4, further comprising: A first amplifier is configured to output the first voltage to the second resistor string; as well as The second amplifier is configured to output the second voltage to the second resistor string.

6. The gamma reference voltage generator according to any one of claims 1 to 4, further comprising: Multiple gamma voltage output amplifiers are respectively connected to the multiple gamma voltage setters.

7. The gamma reference voltage generator according to claim 6, further comprising: Multiple output resistors are connected between the multiple gamma voltage output amplifiers.

8. The gamma reference voltage generator according to claim 1, wherein, The selector includes: The third resistor string is configured to receive the first black candidate voltage and the second black candidate voltage; and The final black voltage setter is configured to extract the black gamma voltage from the third resistor string.

9. The gamma reference voltage generator according to claim 8, further comprising: The black gamma voltage output amplifier is connected to the final black voltage setter.

10. A display device, comprising: The display panel is configured to display images; The drive controller is configured to receive input image data and convert the input image data into a data signal; The gamma reference voltage generator according to any one of claims 1 to 9 is configured to generate the black gamma voltage and the plurality of gamma voltages corresponding to the data signal; and A data driver is configured to output the black gamma voltage and the plurality of gamma voltages to the display panel based on the data signal.

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