Display device and method of driving display panel

Abstract

The invention provides a display device and a method of driving a display panel. The display device includes: a display panel including pixels and configured to display an image based on input image data; a gate driver configured to output a gate signal to the pixel; a data driver configured to output a data voltage to the pixels; and a gamma reference voltage generator including a gamma bias circuit configured to generate a bias current based on a gamma voltage range from a voltage level corresponding to the zero gray level to a voltage level corresponding to the set brightness, and a gamma amplification circuit configured to receive the bias current, the gamma reference voltage generator is configured to generate a gamma reference voltage and output the gamma reference voltage to the data driver.

Description

Technical Field

[0001] Aspects of some embodiments of the present disclosure relate to a display device and a method of driving a display panel using the display device. Background Art

[0002] Generally, a display device includes a display panel and a display panel driver. The display panel includes a plurality of gate lines, a plurality of data lines and a plurality of pixels. The display panel driver includes a gate driver for providing a gate signal to the gate line, a gamma reference voltage generator for providing a gamma reference voltage to the data driver, a data driver for providing a data voltage to the data line, and a drive controller for controlling the gate driver and the data driver.

[0003] The gamma reference voltage generator may include a plurality of gamma amplifiers. When the bias current of the gamma amplifier is set to be low, the display quality may be degraded due to insufficient pixel charge. On the contrary, when the bias current of the gamma amplifier is set to be high, the power consumption may increase.

[0004] The above information disclosed in this Background section is only for enhancement of understanding of the background technology, and therefore the information discussed in this Background section does not necessarily constitute prior art. Summary of the invention

[0005] Some aspects of the present disclosure relate to a display device and a method for driving a display panel using the display device. For example, some aspects of the present disclosure relate to a display device including a plurality of gamma amplifiers having different bias currents and a method for driving a display panel using the display device.

[0006] Aspects of some embodiments of the present disclosure include a display device capable of reducing power consumption by appropriately setting bias currents of a plurality of gamma amplifiers.

[0007] Aspects of some embodiments of the present disclosure also include a method of driving a display panel using a display device.

[0008] According to some embodiments of the present disclosure, a display device includes: a display panel, a gate driver, a data driver, and a gamma reference voltage generator. According to some embodiments, the display panel includes pixels and displays an image based on input image data. According to some embodiments, the gate driver outputs a gate signal to the pixel. According to some embodiments, the data driver outputs a data voltage to the pixel. According to some embodiments, the gamma reference voltage generator includes a gamma bias circuit and a gamma amplification circuit, the gamma bias circuit generates a bias current based on a gamma voltage range from a voltage level corresponding to a zero gray level to a voltage level corresponding to a set brightness, and the gamma amplification circuit receives the bias current. According to some embodiments, the gamma reference voltage generator generates a gamma reference voltage and outputs the gamma reference voltage to the data driver.

[0009] According to some embodiments, based on a voltage level corresponding to a set brightness of the gamma voltage range being higher than a voltage level of a reference brightness, a first bias current may be applied to the gamma amplification circuit.

[0010] According to some embodiments, based on a voltage level corresponding to a set brightness of a gamma voltage range being lower than a voltage level of a reference brightness, a second bias current lower than the first bias current may be applied to the gamma amplification circuit.

[0011] According to some embodiments, based on that a voltage level corresponding to a set brightness of the gamma voltage range is a voltage level of maximum brightness, a third bias current higher than the first bias current may be applied to the gamma amplification circuit.

[0012] According to some embodiments, the bias current may be updated on a frame-by-frame basis.

[0013] According to some embodiments, based on the gamma voltage range of the current frame being wider than the gamma voltage range of the previous frame, the bias current of the current frame may be higher than the bias current of the previous frame.

[0014] According to some embodiments, based on the gamma voltage range of the current frame being narrower than the gamma voltage range of the previous frame, the bias current of the current frame may be lower than the bias current of the previous frame.

[0015] According to some embodiments, the gamma reference voltage generator may further include a gamma voltage setting circuit, which outputs a high gamma reference voltage and a low gamma reference voltage based on input image data. According to some embodiments, the gamma bias circuit may include: a gamma bias setting circuit, which outputs a gamma bias code based on a gamma voltage range; a gamma bias control circuit, which receives the gamma bias code and outputs a gamma bias current code based on the gamma bias code; and a bias current output circuit, which receives the gamma bias current code and outputs a bias current based on the gamma bias current code.

[0016] According to some embodiments, a low gamma reference voltage may be generated based on a set brightness.

[0017] According to some embodiments, the gamma amplification circuit may include a first gamma amplifier and a second gamma amplifier. According to some embodiments, the gamma bias circuit may include a first gamma bias circuit and a second gamma bias circuit. According to some embodiments, a first amplifier bias current generated by the first gamma bias circuit may be applied to the first gamma amplifier. According to some embodiments, a second amplifier bias current generated by the second gamma bias circuit may be applied to the second gamma amplifier. According to some embodiments, the first amplifier bias current and the second amplifier bias current are different.

[0018] According to some embodiments, the gamma amplification circuit may include a first gamma amplifier and a second gamma amplifier. According to some embodiments, the gamma bias circuit may include a first gamma bias circuit and a second gamma bias circuit. According to some embodiments, a first amplifier bias current generated based on a set brightness and a gamma voltage range may be applied to the first gamma amplifier. According to some embodiments, a second amplifier bias current generated based on a set brightness and a gamma voltage range may be applied to the second gamma amplifier. According to some embodiments, the first amplifier bias current and the second amplifier bias current are different.

[0019] According to some embodiments, the gamma reference voltage generator may include: a first gamma amplifying circuit that generates a first gamma reference voltage corresponding to an image of a first color; a second gamma amplifying circuit that generates a second gamma reference voltage corresponding to an image of a second color; and a third gamma amplifying circuit that generates a third gamma reference voltage corresponding to an image of a third color. According to some embodiments, the first gamma amplifying circuit, the second gamma amplifying circuit, and the third gamma amplifying circuit may have different bias currents.

[0020] According to some embodiments, the data driver and the gamma reference voltage generator may be formed as an integrated data driver.

[0021] According to some embodiments, in a method for driving a display panel according to the present disclosure, the method includes: outputting a gate signal to the display panel; generating a gamma reference voltage, generating different gamma bias codes based on a gamma voltage range from a voltage level corresponding to a zero grayscale level to a voltage level corresponding to a set brightness, and using a gamma amplification circuit to receive a bias current based on the different gamma bias codes; and outputting a data voltage to the display panel based on input image data and the gamma reference voltage.

[0022] According to some embodiments, based on a voltage level corresponding to a set brightness of the gamma voltage range being higher than a voltage level of a reference brightness, a first bias current may be applied to the gamma amplification circuit.

[0023] According to some embodiments, based on a voltage level corresponding to a set brightness of a gamma voltage range being lower than a voltage level of a reference brightness, a second bias current lower than the first bias current may be applied to the gamma amplification circuit.

[0024] According to some embodiments, based on that a voltage level corresponding to a set brightness of the gamma voltage range is a voltage level of maximum brightness, a third bias current higher than the first bias current may be applied to the gamma amplification circuit.

[0025] According to some embodiments, the bias current may be updated on a frame-by-frame basis.

[0026] According to some embodiments, based on the gamma voltage range of the current frame being wider than the gamma voltage range of the previous frame, the bias current of the current frame may be higher than the bias current of the previous frame.

[0027] According to some embodiments, based on the gamma voltage range of the current frame being narrower than the gamma voltage range of the previous frame, the bias current of the current frame may be lower than the bias current of the previous frame.

[0028] In a display device and a method for driving a display panel using the display device, according to some embodiments, a bias current of a gamma amplifier can be changed according to data of an image displayed in the display panel, so that power consumption of the display device can be relatively reduced without reducing the display quality of the display panel. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The above and other features and characteristics according to embodiments of the present disclosure will become more apparent by describing aspects of some embodiments of the present disclosure in more detail with reference to the accompanying drawings, in which:

[0030] Figure 1 is a block diagram illustrating a display device according to some embodiments of the present disclosure;

[0031] Figure 2 It is shown that the Figure 1 A block diagram of an example of a gamma reference voltage generator in a display device;

[0032] Figure 3 It is shown that the Figure 1 A block diagram of an example of a gamma reference voltage generator in a display device;

[0033] Figure 4 Is Figure 3 A diagram of a gamma bias code generated by a gamma bias setting circuit;

[0034] Figure 5 Is Figure 3 A diagram of a gamma bias current code generated by a gamma bias control circuit;

[0035] Figure 6 Is Figure 3 A diagram of the bias current generated by the bias current output circuit;

[0036] Figure 7 is a diagram illustrating a gamma reference voltage generator according to some embodiments;

[0037] Figure 8 is a diagram illustrating a gamma reference voltage generator according to some embodiments;

[0038] Fig. 9 is a diagram illustrating a gamma reference voltage generator according to some embodiments;

[0039] Fig.10 is a block diagram illustrating a display device according to some embodiments of the present disclosure;

[0040] Fig.11 is a block diagram illustrating an electronic device according to some embodiments of the present disclosure; and

[0041] Fig.12 It is shown Fig.11 FIG. 5 is a diagram of an example in which the electronic device is implemented as a smart phone. DETAILED DESCRIPTION

[0042] Hereinafter, aspects of some embodiments of the present disclosure will be described in more detail with reference to the accompanying drawings.

[0043] Figure 1 is a block diagram illustrating a display device according to some embodiments of the present disclosure.

[0044] Reference Figure 1 The display device includes a display panel 10 and a display panel driver. The display panel driver may include a driving controller 200, a gate driver 300, a gamma reference voltage generator 400, and a data driver 500.

[0045] For example, the driving controller 200 and the data driver 500 may be integrally formed with each other. For example, the driving controller 200, the gamma reference voltage generator 400 and the data driver 500 may be integrally formed with each other. For example, the driving controller 200, the gate driver 300, the gamma reference voltage generator 400 and the data driver 500 may be integrally formed with each other.

[0046] The display panel 10 includes a display area configured to display an image and a peripheral area adjacent to the display area (eg, in the periphery of the display area or outside the footprint of the display area).

[0047] For example, the display panel 10 may be an organic light emitting diode display panel including organic light emitting diodes. Alternatively, the display panel 10 may be a liquid crystal display panel including liquid crystals.

[0048] The display panel 10 includes a plurality of gate lines GL, a plurality of data lines DL, and a plurality of pixels electrically connected to the gate lines GL and the data lines DL, respectively. The gate lines GL extend in a first direction D1, and the data lines DL extend in a second direction D2 crossing the first direction D1.

[0049] The driving controller 200 receives input image data IMG, input control signal CONT and brightness region data DBV from an external device. For example, the input image data IMG may include red image data, green image data and blue image data. The input image data IMG may include white image data. The input image data IMG may include magenta image data, yellow image data and cyan image data. The input control signal CONT may include a main clock signal and a data enable signal. The input control signal CONT may also include a vertical synchronization signal and a horizontal synchronization signal. The brightness region data DBV may include the brightness of the input image data IMG and a set brightness. For example, the set brightness may be directly set by a user of the display device. Alternatively, the set brightness may be automatically set by sensing the brightness around the display device.

[0050] The driving 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, the input control signal CONT, and the brightness area data DBV.

[0051] The driving controller 200 generates a first control signal CONT1 for controlling the operation of the gate driver 300 based on the input control signal CONT, and outputs the generated 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.

[0052] The driving controller 200 generates a second control signal CONT2 for controlling the operation of the data driver 500 based on the input control signal CONT, and outputs the generated second control signal CONT2 to the data driver 500. The second control signal CONT2 may include a horizontal start signal and a load signal.

[0053] The driving controller 200 generates a data signal DATA based on the input image data IMG. The driving controller 200 outputs the data signal DATA to the data driver 500.

[0054] The driving controller 200 generates a third control signal CONT3 for controlling the operation of the gamma reference voltage generator 400 based on the input control signal CONT, and outputs the generated third control signal CONT3 to the gamma reference voltage generator 400 .

[0055] The gate driver 300 generates a gate signal for driving the gate line GL in response to the first control signal CONT1 received from the driving controller 200. The gate driver 300 may output the gate signal to the gate line GL. For example, the gate driver 300 may sequentially output the gate signal to the gate line GL.

[0056] The gamma reference voltage generator 400 generates a gamma reference voltage VGREF in response to the third control signal CONT3 received from the driving controller 200. The gamma reference voltage generator 400 provides the gamma reference voltage VGREF to the data driver 500. The gamma reference voltage VGREF has a value corresponding to each of the data signals DATA.

[0057] For example, the gamma reference voltage generator 400 can generate a gamma reference voltage VGREF corresponding to a gray level of zero to a gray level of 255. However, the embodiments of the present disclosure are not limited to the gray level range. For example, the gamma reference voltage generator 400 can generate a gamma reference voltage VGREF corresponding to a gray level of zero to a gray level of 2047.

[0058] For example, the gamma reference voltage generator 400 may be located in the driving controller 200 or the data driver 500 .

[0059] The data driver 500 receives the second control signal CONT2 and the data signal DATA from the driving controller 200, and receives the gamma reference voltage VGREF from the gamma reference voltage generator 400. The data driver 500 converts the data signal DATA into a data voltage VDATA having an analog type by using the gamma reference voltage VGREF. The data driver 500 outputs the data voltage VDATA to the data line DL.

[0060] Figure 2 It is shown that the Figure 1 4 is a block diagram of an example of a gamma reference voltage generator 400 in a display device. Figure 3 It is shown that the Figure 1 4 is a block diagram of an example of a gamma reference voltage generator 400 in a display device. Figure 4 Is Figure 3 FIG. 4 is a diagram of a gamma offset code GBC generated by the gamma offset setting circuit 422 . Figure 5 Is Figure 3 The gamma bias control circuit 424 generates a gamma bias current code GBIC. Figure 6 Is Figure 3 FIG. 4 is a diagram of the bias current BI generated by the bias current output circuit 426.

[0061] Reference Figures 2 to 6 , the gamma reference voltage generator 400 may include a gamma voltage setting circuit 410 , a gamma bias circuit 420 , a gamma amplifying circuit 430 , and a gamma output circuit 440 . Figure 2 and Figure 3 The gamma reference voltage generator 400 can be used with Figure 1 The gamma reference voltage generator 400 corresponds to .

[0062] The gamma voltage setting circuit 410 receives a first reference voltage VREF1 and a second reference voltage VREF2, and can select a high gamma reference voltage VGH corresponding to a lowest grayscale gamma tap voltage between the first reference voltage VREF1 and the second reference voltage VREF2 and a low gamma reference voltage VGL corresponding to a highest grayscale gamma tap voltage between the first reference voltage VREF1 and the second reference voltage VREF2. The low gamma reference voltage VGL can be defined as a gamma voltage generated based on a maximum grayscale of input image data IMG in one frame and a set brightness.

[0063] According to some embodiments, the gamma voltage setting circuit 410 may include a first resistor string 412, a first reference selection circuit (also referred to as a first multiplexer or MUX1) 414, a second reference selection circuit (also referred to as a second multiplexer or MUX2) 416, and a third reference selection circuit (also referred to as a third multiplexer or MUX3) 418. The first resistor string 412 may distribute a first reference voltage VREF1 and a second reference voltage VREF2. The first resistor string 412 may include a plurality of resistors connected in series. The first reference voltage VREF1 and the second reference voltage VREF2 may be applied to both ends of the first resistor string 412. A plurality of voltages may be distributed and may be output at contact points between resistors included in the first resistor string 412.

[0064] The first reference selection circuit 414 may select one of the voltages distributed by the first resistor string 412 as the high gamma reference voltage VGH based on the third control signal CONT3. According to some embodiments, the first reference selection circuit 414 may select a gamma reference voltage corresponding to a zero gray level of the input image data IMG as the high gamma reference voltage VGH. The gamma reference voltage corresponding to the zero gray level may be referred to as a voltage level corresponding to the zero gray level.

[0065] The second reference selection circuit 416 receives a plurality of voltages relatively close to the first reference voltage VREF1 from the first resistor string 412, and may select one of the voltages distributed by the first resistor string 412 as a low grayscale gamma reference voltage based on the third control signal CONT3. According to some embodiments, the second reference selection circuit 416 may select a gamma reference voltage corresponding to a low grayscale of the input image data IMG as a low grayscale gamma reference voltage for each frame.

[0066] The third reference selection circuit 418 receives a plurality of voltages relatively close to the second reference voltage VREF2 from the first resistor string 412, can select a low gamma reference voltage VGL based on the set brightness, and can output the low gamma reference voltage VGL. For example, the low gamma reference voltage VGL can correspond to the voltage level of the set brightness. For example, the first reference selection circuit 414, the second reference selection circuit 416, and the third reference selection circuit 418 can be a multiplexer that selects and outputs one of the plurality of input voltages.

[0067] For example, the grayscale of the input image data IMG may have a grayscale of zero to a grayscale of 2047. However, the embodiment according to the present disclosure is not limited to the grayscale range of the input image data IMG. For example, the grayscale of the input image data IMG may have a grayscale of zero to a grayscale of 255.

[0068] The gamma bias circuit 420 may include a gamma bias setting circuit 422 , a gamma bias control circuit 424 , and a bias current output circuit 426 .

[0069] The gamma offset setting circuit 422 may generate a gamma offset code GBC based on a gamma voltage range VGRG from a voltage level corresponding to a zero gray scale to a voltage level corresponding to a set brightness.

[0070] Unlike conventional display devices, the gamma voltage range VGRG of the display device according to the present disclosure can determine the range from the voltage level corresponding to the zero gray level to the low gamma reference voltage VGL, while the voltage level corresponding to the zero gray level is fixed. For example, the voltage level corresponding to the zero gray level can be 7 volts (V) (or about 7V). For example, the low gamma reference voltage VGL can be changed to 1V (or about 1V) in the high brightness area, while the voltage level corresponding to the zero gray level is fixed. In this case, the gamma voltage range VGRG in the high brightness area can be 6V (or about 6V). For example, the low gamma reference voltage VGL can be changed to 5V (or about 5V) in the low brightness area (i.e., the brightness area lower than the high brightness area), while the voltage level corresponding to the zero gray level is fixed. In this case, the gamma voltage range VGRG in the low brightness area can be 2V (or about 2V). However, embodiments according to the present disclosure are not limited to the above voltage levels.

[0071] In the gamma voltage range VGRG of the display device according to the present disclosure, the low gamma reference voltage VGL can be changed, while the voltage level corresponding to the zero gray level is fixed. Therefore, the gamma voltage range VGRG can be determined by the changed low gamma reference voltage (e.g., setting the brightness voltage level). In addition, the gamma bias circuit 420 can easily control the bias current BI applied to the gamma amplification circuit 430 in the high brightness area and the low brightness area.

[0072] According to some embodiments, the maximum reference range RG1 may be determined to range from a voltage level corresponding to zero grayscale to a voltage level corresponding to maximum brightness. The reference range may be determined to range from a voltage level corresponding to zero grayscale to a voltage level corresponding to reference brightness.

[0073] For example, the range from the voltage level corresponding to the zero gray level to the voltage level corresponding to the first reference brightness may be referred to as the first reference range RG2. For example, the range from the voltage level corresponding to the zero gray level to the voltage level corresponding to the second reference brightness may be referred to as the second reference range RG3. For example, the range from the voltage level corresponding to the zero gray level to the voltage level corresponding to the third reference brightness may be referred to as the third reference range RG4. For example, the range from the voltage level corresponding to the zero gray level to the voltage level corresponding to the fourth reference brightness may be referred to as the fourth reference range RG5. For example, the range from the voltage level corresponding to the zero gray level to the voltage level corresponding to the fifth reference brightness may be referred to as the fifth reference range RG6. For example, the range from the voltage level corresponding to the zero gray level to the voltage level corresponding to the sixth reference brightness may be referred to as the sixth reference range RG7. For example, the range from the voltage level corresponding to the zero gray level to the voltage level corresponding to the seventh reference brightness may be referred to as the seventh reference range RG8.

[0074] According to some embodiments, when the gamma voltage range VGRG is a maximum reference range RG1 from a voltage level corresponding to a zero grayscale to a voltage level corresponding to a maximum brightness, a first gamma offset code GBC1 may be generated. When the gamma voltage range VGRG is wider than the first reference range RG2 and narrower than the maximum reference range RG1, a second gamma offset code GBC2 may be generated. When the gamma voltage range VGRG is wider than the second reference range RG3 narrower than the first reference range RG2 and narrower than the first reference range RG2, a third gamma offset code GBC3 may be generated. When the gamma voltage range VGRG is wider than the third reference range RG4 narrower than the second reference range RG3 and narrower than the second reference range RG3, a fourth gamma offset code GBC4 may be generated. When the gamma voltage range VGRG is wider than the fourth reference range RG5 narrower than the third reference range RG4 and narrower than the third reference range RG4, a fifth gamma offset code GBC5 may be generated. When the gamma voltage range VGRG is wider than the fifth reference range RG6 narrower than the fourth reference range RG5 and narrower than the fourth reference range RG5, the sixth gamma offset code GBC6 may be generated. When the gamma voltage range VGRG is wider than the sixth reference range RG7 narrower than the fifth reference range RG6 and narrower than the fifth reference range RG6, the seventh gamma offset code GBC7 may be generated. When the gamma voltage range VGRG is wider than the seventh reference range RG8 narrower than the sixth reference range RG7 and narrower than the sixth reference range RG7, the eighth gamma offset code GBC8 may be generated.

[0075] The first reference brightness to the seventh reference brightness can be set during the manufacturing process of the display device. For example, when the maximum brightness is 100%, the first reference brightness can be 93.75% (or approximately 93.75%). However, according to the embodiment of the present disclosure, it is not limited to the value of the reference brightness. For example, the setting brightness voltage level can be expressed as a 3-bit hexadecimal value. For example, when the setting brightness voltage level has a voltage level corresponding to the maximum brightness, the setting brightness voltage level can be expressed as an FFF code, and when the setting brightness voltage level has a voltage level corresponding to the first reference brightness (for example, 93.75% or approximately 93.75%), the setting brightness voltage level can be expressed as an F00 code. In addition, according to the embodiment of the present disclosure, it is not limited to the number of reference brightnesses. For example, the number of reference brightnesses can be set by the user.

[0076] The gamma bias control circuit 424 may receive the gamma bias code GBC from the gamma bias setting circuit 422. The gamma bias control circuit 424 may generate the gamma bias current code GBIC based on the gamma bias code GBC.

[0077] For example, the gamma bias control circuit 424 can generate a first gamma bias current code 111 based on the first gamma bias code GB1, can generate a second gamma bias current code 110 based on the second gamma bias code GB2, can generate a third gamma bias current code 101 based on the third gamma bias code GB3, can generate a fourth gamma bias current code 100 based on the fourth gamma bias code GB4, can generate a fifth gamma bias current code 011 based on the fifth gamma bias code GB5, can generate a sixth gamma bias current code 010 based on the sixth gamma bias code GB6, can generate a seventh gamma bias current code 001 based on the seventh gamma bias code GB7, and can generate an eighth gamma bias current code 000 based on the eighth gamma bias code GB8.

[0078] For example, the gamma bias current code GBIC may be a code of a binary number. The gamma bias current code GBIC may have a quantity corresponding to the gamma bias code GBC. However, the present disclosure is not limited to the quantity of the gamma bias current code GBIC. For example, the quantity of the gamma bias current code GBIC may be less than the quantity of the gamma bias code GBC. In addition, although the gamma bias current code GBIC is described as a 3-bit value, the gamma bias current code GBIC of the present disclosure is not limited to a bit value. For example, the gamma bias current code GBIC may have a 4-bit value.

[0079] The bias current output circuit 426 may receive the gamma bias current code GBIC from the gamma bias circuit 420. The bias current output circuit 426 may output the bias current BI based on the gamma bias current code GBIC.

[0080] For example, when the bias current output circuit 426 receives the fourth gamma bias code 100, the bias current output circuit 426 may output a reference bias current as the bias current BI. For example, the reference bias current may be 0.3 mA (or approximately 0.03 mA). However, embodiments according to the present disclosure are not limited to the value of the reference bias current.

[0081] When the bias current output circuit 426 receives the first gamma bias current code 111, the bias current output circuit 426 may output a current corresponding to 137.5% (or approximately 137.5%) of the reference bias current as the bias current BI. When the bias current output circuit 426 receives the second gamma bias current code 110, the bias current output circuit 426 may output a current corresponding to 125% (or approximately 125%) of the reference bias current as the bias current BI. When the bias current output circuit 426 receives the third gamma bias current code 101, the bias current output circuit 426 may output a current corresponding to 112.5% ​​(or approximately 112.5%) of the reference bias current as the bias current BI. When the bias current output circuit 426 receives the fifth gamma bias current code 011, the bias current output circuit 426 may output a current corresponding to 87.5% (or approximately 87.5%) of the reference bias current as the bias current BI. When the bias current output circuit 426 receives the sixth gamma bias current code 010, the bias current output circuit 426 may output a current corresponding to 75% (or approximately 75%) of the reference bias current as the bias current BI. When the bias current output circuit 426 receives the seventh gamma bias current code 001, the bias current output circuit 426 may output a current corresponding to 62.5% (or approximately 62.5%) of the reference bias current as the bias current BI. When the bias current output circuit 426 receives the eighth gamma bias current code 000, the bias current output circuit 426 may output a current corresponding to approximately 50% of the reference bias current as the bias current BI. However, the value of each of the bias currents BI corresponding to the gamma bias current code GBIC according to an embodiment of the present disclosure may be determined by a user, so that the embodiment according to the present disclosure is not limited to the ratio of the reference bias current.

[0082] According to some embodiments, the bias current output circuit 426 of the display device including the gamma reference voltage generator 400 generates and outputs different bias currents BI based on the gamma voltage range VGRG.

[0083] The gamma amplification circuit 430 may generate and output a plurality of gamma tap voltages (i.e., second gamma tap voltage VT2 to ninth gamma tap voltage VT9) between the lowest grayscale gamma tap voltage (i.e., first gamma tap voltage VT1) and the highest grayscale gamma tap voltage (i.e., tenth gamma tap voltage VT10) based on the high gamma reference voltage VGH and the low gamma reference voltage VGL. The gamma amplification circuit 430 may receive the high gamma reference voltage VGH output from the first reference selection circuit 414 and the low gamma reference voltage VGL output from the third reference selection circuit 418. The gamma amplification circuit 430 distributes the high gamma reference voltage VGH and the low gamma reference voltage VGL, selects an intermediate gamma voltage among the distributed voltages, generates gamma tap voltages VT1 to VT10, and outputs the gamma tap voltages VT1 to VT10.

[0084] According to some embodiments, the gamma amplification circuit 430 may include a second resistor string 432, a plurality of gamma tap selection circuits 434, and a gamma amplifier 436. The second resistor string 432 may include a plurality of resistor strings R-STRING. The second resistor string 432 may be connected in cascade form to allocate a high reference gamma voltage VGH and a low gamma reference voltage VGL. The gamma tap selection circuit 434 may include a plurality of multiplexers MUX. The gamma tap selection circuit 434 may select a portion of the voltage allocated by the second resistor string 432 based on a plurality of gamma tap selection signals CS1 to CS10. For example, each of the gamma tap selection circuits 434 may be a multiplexer that selects one of a plurality of input voltages. In this case, the gamma tap selection signals CS1 to CS10 may be selected by a user's input or an external input, or may be stored during the manufacturing process. The gamma amplifier 436 may output a voltage selected by the gamma tap selection circuit 434 as a gamma tap voltage VT1 to VT10 based on the gamma bias current code GBIC. The gamma amplifier 436 may have a bias current BI based on a gamma bias current code GBIC.

[0085] Generally, it takes a long charging time to generate a gamma reference voltage VGREF corresponding to a high brightness region from the gamma reference voltage generator 400. In addition, the values ​​of the gamma tap voltages VT1 to VT10 may be changed by outputting the gamma reference voltage VGREF in the high brightness region. A long recovery time is required to recover the changed values ​​of the gamma tap voltages VT1 to VT10. A current higher than the reference bias current may be applied to the gamma amplifier 436 of the present disclosure in the high brightness region to relatively reduce the long charging time and the recovery time.

[0086] Furthermore, a long charging time is not required to generate the gamma reference voltage VGREF corresponding to the low brightness region from the gamma reference voltage generator 400. Therefore, a current lower than the reference bias current can be applied to the gamma amplifier 436 of the present disclosure in the low brightness region to relatively reduce power consumption.

[0087] In addition, the gamma bias circuit 420 can output different bias currents BI for each gamma voltage range VGRG to the gamma amplification circuit 430 through the reference ranges RG1 to RG8 set by the user. Therefore, by relatively reducing power consumption, charging time and recovery time can be improved, and the display quality of the display panel 10 can be improved.

[0088] The gamma amplifier circuit 430 may have a cascade structure. The gamma amplifier circuit 430 may include a plurality of stages. For example, the gamma amplifier circuit 430 may include a first stage to a tenth stage that outputs a first gamma tap voltage VT1 to a tenth gamma tap voltage VT10. The first stage may output a high reference gamma voltage VGH as the first gamma tap voltage VT1. The first gamma tap voltage VT1 may correspond to a gamma voltage V0 of zero gray level. The Kth stage that outputs the Kth gamma tap voltage (wherein K is an integer between 2 and 9) may include a resistor string, a gamma tap selection circuit, and a gamma amplifier. The Kth stage may use a resistor string to allocate the first gamma tap voltage VT1 and the K+1th gamma tap voltage, may select one of the allocated voltages generated by the gamma tap selection circuit, and may use the gamma amplifier to output the selected voltage as the Kth gamma tap voltage. For example, the second stage can use a resistor string to allocate a first gamma tap voltage VT1 and a third gamma tap voltage VT3, can select one of the allocated voltages generated by the gamma tap selection circuit, and can use the gamma amplifier to output the selected voltage as the second gamma tap voltage VT2. The second gamma tap voltage VT2 can correspond to the gamma voltage V3 of the three gray levels. The tenth stage can output a low gamma reference voltage VGL as the tenth gamma tap voltage VT10. The tenth gamma tap voltage VT10 can correspond to the gamma voltage V2047 of the 2047 gray level. The bias current BI of the gamma amplifiers of the first to tenth stages can be controlled based on the gamma bias current code GBIC.

[0089] The gamma output circuit 440 can distribute the gamma tap voltages VT1 to VT10 to output the gamma voltages V0 to V2047. According to some embodiments, the gamma output circuit 440 can generate the gamma voltages V0 to V2047 by distributing the gamma tap voltages VT1 to VT10 using a third resistor string. However, the present disclosure is not limited to the number of gamma voltages that the gamma output circuit 440 can generate.

[0090] According to some embodiments, the bias current BI of the gamma amplification circuit may be updated frame by frame. For example, when the gamma voltage range VGRG of the current frame is wider than the gamma voltage range VGRG of the previous frame, the bias current BI of the current frame may be higher than the bias current BI of the previous frame. When the gamma voltage range VGRG of the current frame is narrower than the gamma voltage range VGRG of the previous frame, the bias current BI of the current frame may be lower than the bias current BI of the previous frame. In the display device, the bias current BI is updated frame by frame, so that the power consumption of the display device can be more easily controlled.

[0091] Figure 7 is a diagram illustrating a gamma reference voltage generator 400A according to some embodiments.

[0092] The display device and the method of driving a display panel using the display device according to the present embodiment are similar to those of the reference 100 except for the structure of the gamma reference voltage generator 400A. Figures 1 to 6 The described display device and the method of driving a display panel using the same are substantially the same, so that the same reference numerals will be used to refer to the same elements and some repeated explanations regarding the above elements may be omitted.

[0093] Reference Figure 7 , also refer to Figure 1 , Figure 2 and Figures 4 to 6 The gamma bias circuit 420A of the gamma reference voltage generator 400A according to the present embodiment may include first to tenth gamma bias circuits 420-1 to 420-10. The gamma amplification circuit 430A may include first to tenth gamma amplifiers AMM1 to AMM10 corresponding to the first to tenth gamma bias circuits 420-1 to 420-10, respectively.

[0094] For example, the first gamma bias circuit 420-1 may generate a first amplifier gamma bias code based on a gamma voltage range VGRG from a voltage level corresponding to zero grayscale to a voltage level corresponding to set brightness. The first gamma amplifier AMM1 may receive a first amplifier bias current based on the first amplifier gamma bias code.

[0095] For example, the second gamma bias circuit 420-2 may generate a second amplifier gamma bias code different from the first amplifier gamma bias code based on a gamma voltage range VGRG from a voltage level corresponding to a zero grayscale to a voltage level corresponding to a set brightness. The second gamma amplifier AMM2 may receive a second amplifier bias current different from the first amplifier bias current based on the second amplifier gamma bias code.

[0096] For example, the third gamma bias circuit 420-3 to the tenth gamma bias circuit 420-10 may generate third to tenth amplifier gamma bias codes different from the first and second amplifier gamma bias codes based on a gamma voltage range VGRG from a voltage level corresponding to a zero gray level to a voltage level corresponding to a set brightness. The third to tenth gamma amplifiers AMM3 to AMM10 may receive third to tenth amplifier bias currents different from the first and second amplifier bias currents based on the third to tenth amplifier gamma bias codes.

[0097] The bias currents BI applied to the first to tenth gamma amplifiers AMM1 to AMM10 are different, so that the power consumption of the display device of the present disclosure may be more easily controlled.

[0098] Figure 8 is a diagram illustrating a gamma reference voltage generator 400B according to some embodiments.

[0099] Except for the structure of the gamma reference voltage generator 400B, the display device and the method of driving a display panel using the display device according to the present embodiment are similar to those of the reference embodiment. Figures 1 to 6 The described display device and a method of driving a display panel using the same are substantially the same, so that the same reference numerals will be used to refer to the same elements and some repeated explanations regarding the above elements may be omitted.

[0100] Reference Figure 8 , also refer to Figure 1 , Figure 2 and Figures 4 to 6 According to some embodiments, the gamma amplifier circuit 430B of the gamma reference voltage generator 400B may further include a brightness setting circuit 438. The brightness setting circuit 438 may include brightness setting registers REG1 to REG10. The brightness setting registers REG1 to REG10 may apply current signals to the gamma amplifiers AMM1 to AMM10 based on the set brightness. The gamma amplifiers AMM1 to AMM10 may receive the current signals respectively. In addition, the bias currents BI of the gamma amplifiers AMM1 to AMM10 may be completely controlled based on the gamma voltage range VGRG.

[0101] That is, the gamma amplifiers AMM1 to AMM10 according to the present disclosure may have different bias currents BI, and further, the bias currents BI of the gamma amplifiers AMM1 to AMM10 may be fully controlled. Therefore, the power consumption of the display device according to the present disclosure may be more effectively controlled.

[0102] Fig. 9is a diagram illustrating a gamma reference voltage generator 400C according to some embodiments.

[0103] Except for the structure of the gamma reference voltage generator 400C, the display device and the method of driving a display panel using the display device according to the present embodiment are similar to those of the reference embodiment. Figures 1 to 6 The described display device and a method of driving a display panel using the same are substantially the same, so that the same reference numerals will be used to refer to the same elements and some repeated explanations regarding the above elements may be omitted.

[0104] Reference Figure 1 , Figure 2 , Figures 4 to 6 and Fig. 9 The display device includes a display panel 10 and a display panel driver. The display panel driver includes a driving controller 200, a gate driver 300, a gamma reference voltage generator 400 or 400C, and a data driver 500.

[0105] Reference Fig. 9 According to some embodiments, the gamma reference voltage generator 400C may include: a gamma output circuit 440; a master gamma reference voltage generator 460 including master gamma amplifiers AMM1 to AMM10 outputting master gamma reference voltages VG1 to VG10; and a slave gamma reference voltage generator 470 including slave gamma amplifiers AMS1 to AMS10 receiving the master gamma reference voltages VG1 to VG10 and outputting the master gamma reference voltages VG1 to VG10 to the data driver 500 and slave resistor strings RS1 to RS10 positioned between the slave gamma amplifiers AMS1 to AMS10. The slave resistor strings RS1 to RS10 of the slave gamma reference voltage generator 470 may output slave gamma reference voltages having levels between the master gamma reference voltages VG1 to VG10.

[0106] For example, the master gamma amplifiers AMM1 to AMM10 may correspond one-to-one to the slave gamma amplifiers AMS1 to AMS10.

[0107] The master gamma amplifier and the slave gamma amplifier corresponding to each other may have the same bias current BI. For example, Fig. 9 The bias current BI may be applied to the master gamma amplifier and the slave gamma amplifier.

[0108] According to some embodiments, the slave gamma reference voltage generator 470 may include a first gamma amplifier generating a first gamma reference voltage corresponding to an image of a first color, a second gamma amplifier generating a second gamma reference voltage corresponding to an image of a second color, and a third gamma amplifier generating a third gamma reference voltage corresponding to an image of a third color. A first color bias current of the first gamma amplifier may be generated based on a set brightness, a second color bias current of the second gamma amplifier may be generated based on a set brightness, and a third color bias current of the third gamma amplifier may be generated based on a set brightness. The first color bias current, the second color bias current, and the third color bias current may be the same or different.

[0109] According to some embodiments, the master gamma amplifiers AMM1 to AMM10 and the slave gamma amplifiers AMS1 to AMS10 of the display device including the gamma reference voltage generator 400C may receive different bias currents BI based on set brightness.

[0110] Generally, it takes a long charging time to generate the gamma reference voltage VGREF corresponding to the high brightness area from the gamma reference voltage generator 400C. In addition, the values ​​of the gamma tap voltages VT1 to VT10 may be changed by outputting the gamma reference voltage VGREF in the high brightness area. A long recovery time is required to recover the changed values ​​of the gamma tap voltages VT1 to VT10. Therefore, the master gamma amplifiers AMM1 to AMM10 and the slave gamma amplifiers AMS1 to AMS10 of the present disclosure may receive a current higher than the reference bias current in the high brightness area to relatively reduce the long charging time and the recovery time.

[0111] In addition, the gamma reference voltage VGREF corresponding to the low brightness area generated by the gamma reference voltage generator 400C does not require a long charging time. Therefore, the master gamma amplifiers AMM1 to AMM10 and the slave gamma amplifiers AMS1 to AMS10 of the present disclosure can receive a current lower than the reference bias current in the low brightness area to relatively reduce power consumption.

[0112] In addition, the master gamma reference voltage generator 460 and the slave gamma reference voltage generator 470 can generate the first color bias current, the second color bias current, and the third color bias current having different values ​​within the reference range RG1 to RG8 set by the user. Therefore, by relatively reducing power consumption, the charging time and the recovery time can be improved, and the display quality of the display panel 10 can be improved.

[0113] Fig.10 is a block diagram illustrating a display device according to some embodiments of the present disclosure.

[0114] The display device and the method of driving a display panel using the display device according to the present embodiment are similar to those of the reference 1 except for the structures of the data driver and the gamma reference voltage generator. Figures 1 to 6 The described display device and a method of driving a display panel using the same are substantially the same, so that the same reference numerals will be used to refer to the same elements and some repeated explanations regarding the above elements may be omitted.

[0115] Reference Figures 2 to 6 and Fig.10 The display device includes a display panel 10 and a display panel driver. The display panel driver includes a driving controller 200, a gate driver 300, a gamma reference voltage generator 620 and a data driver 640.

[0116] According to some embodiments, the gamma reference voltage generator 620 and the data driver 640 may form a single integrated data driver 600 .

[0117] According to some embodiments, the gamma amplifier 436 of the gamma reference voltage generator 620 may receive the bias current BI based on the set brightness.

[0118] According to some embodiments, the bias current BI of the gamma amplifier is controlled according to the brightness area data DBV displayed in the display panel 10 , so that the power consumption of the display device can be relatively reduced without reducing the display quality of the display panel 10 .

[0119] Fig.11 is a block diagram illustrating an electronic device according to some embodiments of the present disclosure. Fig.12 It is shown Fig.11 FIG. 5 is a diagram of an example in which the electronic device is implemented as a smart phone.

[0120] Reference Fig.11 and Fig.12 , the electronic device 1000 may include a processor 1010, a memory device 1020, a storage device 1030, an input / output (I / O) device 1040, a power supply 1050, and a display device 1060. In this document, the display device 1060 may be Figure 1 In addition, the electronic device 1000 may further include a plurality of ports for communicating with a video card, a sound card, a memory card, a universal serial bus (USB) device, other electronic devices, and the like.

[0121] According to some embodiments, Fig.12As shown in , the electronic device 1000 can be implemented as a smart phone. However, the electronic device 1000 is not limited thereto. For example, the electronic device 1000 can be implemented as a cellular phone, a video phone, a smart tablet, a smart watch, a tablet personal computer (PC), a car navigation system, a computer monitor, a laptop computer, and a head mounted display (HMD) device, etc.

[0122] The processor 1010 may perform various computing functions or various tasks. The processor 1010 may be a microprocessor, a central processing unit (CPU), an application processor (AP), etc. The processor 1010 may be coupled to other components via an address bus, a control bus, a data bus, etc. In addition, the processor 1010 may be coupled to an expansion bus, such as a peripheral component interconnect (PCI) bus.

[0123] The processor 1010 can output the input image data IMG and the input control signal CONT to Figure 1 A drive controller 200 is provided.

[0124] The memory device 1020 may store data used for the operation of the electronic device 1000. For example, the memory device 1020 may include at least one nonvolatile memory device such as an erasable programmable read-only memory (EPROM) device, an electrically erasable programmable read-only memory (EEPROM) device, a flash memory device, a phase change random access memory (PRAM) device, a resistive random access memory (RRAM) device, a nano floating gate memory (NFGM) device, a polymer random access memory (PoRAM) device, a magnetic random access memory (MRAM) device, and a ferroelectric random access memory (FRAM) device, and / or at least one volatile memory device such as a dynamic random access memory (DRAM) device, a static random access memory (SRAM) device, and a mobile DRAM device.

[0125] The storage device 1030 may include a solid state drive (SSD) device, a hard disk drive (HDD) device, a CD-ROM device, etc. The I / O device 1040 may include input devices such as a keyboard, a keypad, a mouse device, a touch pad, and a touch screen, and output devices such as a printer and a speaker. In some embodiments, the display device 1060 may be included in the I / O device 1040. The power supply 1050 may provide power for the operation of the electronic device 1000. The display device 1060 may be coupled to other components via a bus or other communication link.

[0126] In a display device and a method of driving a display panel using the same, according to some embodiments, a bias current of a gamma amplifier is changed according to data of an image displayed in the display panel, so that power consumption of the display device can be relatively reduced.

[0127] The foregoing is an illustration of the present disclosure and should not be construed as limiting the present disclosure. Although aspects of some embodiments of the present disclosure have been described, it will be readily appreciated by those skilled in the art that many modifications in the embodiments are possible without substantially departing from the novel teachings and features of the embodiments according to the present disclosure. Therefore, all such modifications are intended to be included within the scope of the present disclosure as defined in the claims. In the claims, means plus function clauses are intended to cover the structures described herein that perform the functions described, including not only structural equivalents but also equivalent structures. Therefore, it should be understood that the foregoing is an illustration of the present disclosure and should not be construed as being limited to the specific embodiments disclosed, and modifications to the disclosed embodiments as well as other embodiments are intended to be included within the scope of the appended claims. Embodiments according to the present disclosure are defined by the appended claims, and the equivalents of the claims are included therein.

Claims

1. A display device, wherein: The display device comprises: a display panel including pixels and configured to display an image based on input image data; a gate driver configured to output a gate signal to the pixel; a data driver configured to output a data voltage to the pixel; and A gamma reference voltage generator includes a gamma bias circuit and a gamma amplification circuit, wherein the gamma bias circuit is configured to generate a bias current based on a gamma voltage range from a voltage level corresponding to a zero grayscale to a voltage level corresponding to a set brightness, the gamma amplification circuit is configured to receive the bias current, and the gamma reference voltage generator is configured to generate a gamma reference voltage and output the gamma reference voltage to the data driver.

2. The display device according to claim 1, wherein: A first bias current is applied to the gamma amplifying circuit based on the voltage level corresponding to the set brightness of the gamma voltage range being higher than a voltage level of a reference brightness.

3. The display device according to claim 2, wherein: Based on the voltage level corresponding to the set brightness of the gamma voltage range being lower than the voltage level of the reference brightness, a second bias current lower than the first bias current is applied to the gamma amplification circuit.

4. The display device according to claim 2, wherein: Based on the voltage level corresponding to the set brightness of the gamma voltage range being a voltage level of maximum brightness, a third bias current higher than the first bias current is applied to the gamma amplification circuit.

5. The display device according to claim 1, wherein: The bias current is updated frame by frame.

6. The display device according to claim 5, wherein: Based on the gamma voltage range of the current frame being wider than the gamma voltage range of the previous frame, the bias current of the current frame is higher than the bias current of the previous frame.

7. The display device according to claim 5, wherein: Based on the gamma voltage range of the current frame being narrower than the gamma voltage range of the previous frame, the bias current of the current frame is lower than the bias current of the previous frame.

8. The display device according to claim 1, wherein: The gamma reference voltage generator further includes a gamma voltage setting circuit configured to output a high gamma reference voltage and a low gamma reference voltage based on the input image data, and Wherein, the gamma bias circuit comprises: a gamma bias setting circuit configured to output a gamma bias code based on the gamma voltage range; a gamma bias control circuit configured to receive the gamma bias code, and the gamma bias control circuit configured to output a gamma bias current code based on the gamma bias code; and The bias current output circuit is configured to receive the gamma bias current code, and the bias current output circuit is configured to output the bias current based on the gamma bias current code.

9. The display device according to claim 8, wherein: The low gamma reference voltage is generated based on the set brightness.

10. The display device according to claim 1, wherein: The gamma amplifier circuit includes a first gamma amplifier and a second gamma amplifier. Wherein, the gamma bias circuit includes a first gamma bias circuit and a second gamma bias circuit, wherein a first amplifier bias current generated by the first gamma bias circuit is applied to the first gamma amplifier, wherein a second amplifier bias current generated by the second gamma bias circuit is applied to the second gamma amplifier, and The first amplifier bias current and the second amplifier bias current are different.

11. The display device according to claim 1, wherein: The gamma amplifier circuit includes a first gamma amplifier and a second gamma amplifier. wherein a first amplifier bias current generated based on the set brightness and the gamma voltage range is applied to the first gamma amplifier, wherein a second amplifier bias current generated based on the set brightness and the gamma voltage range is applied to the second gamma amplifier, and The first amplifier bias current and the second amplifier bias current are different.

12. The display device according to claim 1, wherein: The gamma reference voltage generator includes: a first gamma amplifying circuit configured to generate a first gamma reference voltage corresponding to an image of a first color; a second gamma amplifying circuit configured to generate a second gamma reference voltage corresponding to an image of a second color; and a third gamma amplifying circuit configured to generate a third gamma reference voltage corresponding to an image of a third color, and The first gamma amplifying circuit, the second gamma amplifying circuit and the third gamma amplifying circuit have different bias currents.

13. The display device according to claim 1, wherein: The data driver and the gamma reference voltage generator are formed as an integrated data driver.

14. A method for driving a display panel, wherein: The method comprises: Outputting a gate signal to a display panel; generating a gamma reference voltage, generating different gamma offset codes based on a gamma voltage range from a voltage level corresponding to a zero grayscale to a voltage level corresponding to a set brightness, and receiving a bias current based on the different gamma offset codes using a gamma amplification circuit; and Data voltages are output to the display panel based on input image data and the gamma reference voltages.

15. The method according to claim 14, wherein: Based on that a voltage level corresponding to the set brightness of the gamma voltage range is higher than a voltage level of a reference brightness, a first bias current is applied to the gamma amplification circuit.

16. The method according to claim 15, wherein: Based on the voltage level corresponding to the set brightness of the gamma voltage range being lower than the voltage level of the reference brightness, a second bias current lower than the first bias current is applied to the gamma amplification circuit.

17. The method according to claim 15, wherein: Based on the voltage level corresponding to the set brightness of the gamma voltage range being a voltage level of maximum brightness, a third bias current higher than the first bias current is applied to the gamma amplification circuit.

18. The method according to claim 14, wherein: The method further includes updating the bias current frame by frame.

19. The method according to claim 18, wherein: Based on the gamma voltage range of the current frame being wider than the gamma voltage range of the previous frame, the bias current of the current frame is higher than the bias current of the previous frame.

20. The method according to claim 18, wherein: Based on the gamma voltage range of the current frame being narrower than the gamma voltage range of the previous frame, the bias current of the current frame is lower than the bias current of the previous frame.

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