# US 2022/0044616 A1 · Gamma reference voltage generator and display apparatus including the same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2022/0044616 A1 - Document ID: US20220044616A1 - Status: Published application - Kind: A1 - Application number: 17/355,446 - Filed: 2021-06-23 - Published: 2022-02-10 - Earliest claimed: 2020-08-10 - Assignees: Samsung Display Co., Ltd. - Applicants: Samsung Display Co., Ltd. - Inventors: Yunki Baek; Nam-Gon Choi; Hansin Lim - Web page: https://patentgrep.com/patent/US20220044616A1 ## CPC - G09G 3/2007: {Display of intermediate tones} - G09G 3/3696: {Generation of voltages supplied to electrode drivers} - G09G 3/3685: {Details of drivers for data electrodes} - G09G 2300/0842: forming a memory circuit, e.g. a dynamic memory with one capacitor - G09G 2310/0243: Details of the generation of driving signals - G09G 2310/027: Details of drivers for data electrodes, the drivers handling digital grey scale data, e.g. use of D/A converters - G09G 2310/0291: Details of output amplifiers or buffers arranged for use in a driving circuit - G09G 2320/0238: Improving the black level - G09G 2320/0276: for the purpose of adaptation to the characteristics of a display device, i.e. gamma correction - G09G 2330/028: Generation of voltages supplied to electrode drivers in a matrix display other than LCD - G09G: ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION (arrangements for transferring data between digital computers and displays G06F3/14; static indicating arrangements comprising an association of a number of separate sources or light control cells G09F9/00; static indicating arrangements comprising integral associations of a number of light sources H01J, H01K, H10H, H05B33/12; scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission, details thereof H04N1/00) ## Abstract A gamma reference voltage generator includes a first resistor string, black voltage setters, a selector, and a second resistor string. The first resistor string receives a first reference voltage and a second reference voltage. The black voltage setters extract 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 one of the black candidate voltages and a second voltage extracted from the first resistor string. In addition, the gamma reference voltage generator includes gamma voltage setters that extract a plurality of gamma voltages from the second resistor string. ## Claims ### Claim 1 A gamma reference voltage generator, comprising: 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, the selection signal generated based on a black level command signal applied from a host; a second resistor string configured to receive a first voltage and a 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. ### Claim 2 (depends on 1) The gamma reference voltage generator of claim 1, wherein the selector comprises a decoder configured to output one of the black candidate voltages in response to the selection signal. ### Claim 3 (depends on 2) The gamma reference voltage generator of claim 2, further comprising: a black gamma voltage output amplifier connected to the decoder. ### Claim 4 (depends on 1) The gamma reference voltage generator of claim 1, wherein the first voltage is a minimum voltage among the black candidate voltages. ### Claim 5 (depends on 1) The gamma reference voltage generator of claim 1, further comprising: a first amplifier configured to output the first voltage to the second resistor string; and a second amplifier configured to output the second voltage to the second resistor string. ### Claim 6 (depends on 1) The gamma reference voltage generator of claim 1, further comprising: a plurality of gamma voltage output amplifiers respectively connected to the plurality of the gamma voltage setters. ### Claim 7 (depends on 6) The gamma reference voltage generator of claim 6, further comprising: a plurality of output resistors connected between the plurality of gamma voltage output amplifiers. ### Claim 8 (depends on 1) The gamma reference voltage generator of claim 1, wherein the selector comprises: a third resistor string configured to receive a first black candidate voltage and a second black candidate voltage; and a final black voltage setter configured to extract the black gamma voltage from the third string. ### Claim 9 (depends on 8) The gamma reference voltage generator of claim 8, further comprising: a black gamma output amplifier connected to the final black voltage setter. ### Claim 10 A display apparatus, comprising: a display panel configured to display an image; a driving controller configured to receive input image data and to 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, wherein the gamma reference voltage generator is configured to select one of a plurality of black candidate voltages as a black gamma voltage to be output to the display panel based on a selection signal and wherein the selection signal is based on a black level command signal from a host. ### Claim 11 (depends on 10) The display apparatus of claim 10, wherein the gamma reference voltage generator comprises: 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 the black candidate voltages from the first resistor string; a selector configured to select the one of the black candidate voltages as the black gamma voltage based on the selection signal; a second resistor string configured to receive a first voltage which is one of the black candidate voltages and a 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. ### Claim 12 (depends on 11) The display apparatus of claim 11, wherein the selector comprises a decoder configured to output one of the black candidate voltages in response to the selection signal. ### Claim 13 (depends on 11) The display apparatus of claim 11, wherein the selector comprises: a third resistor string configured to receive a first black candidate voltage and a second black candidate voltage; and a final black voltage setter configured to extract the black gamma voltage from the third string. ### Claim 14 (depends on 11) The display apparatus of claim 11, wherein: the driving controller includes a lookup table, the lookup table is configured to store output values for a predetermined number of grayscale values of the input image data, except for an output value for a grayscale value of 0. ### Claim 15 (depends on 10) The display apparatus of claim 10, wherein: the driving controller includes a lookup table, and the lookup table is configured to store a plurality of candidate data corresponding to a grayscale value of 0 of the input image data, and is configured to output one of the candidate data as a black data signal based on the selection signal to the gamma reference voltage generator. ### Claim 16 (depends on 15) The display apparatus of claim 15, wherein the gamma reference voltage generator is configured to output the black gamma voltage corresponding to the black data signal. ### Claim 17 (depends on 10) The display apparatus of claim 10, further comprising: a first nonvolatile memory configured to storing a black selection enable signal input from the host and a set black value and a module black value set by the driving controller, wherein the selection signal is to select one of the set black value or the module black value in response to the black selection enable signal. ### Claim 18 (depends on 17) The display apparatus of claim 17, wherein the first nonvolatile memory includes an one time programmable memory. ### Claim 19 (depends on 10) The display apparatus of claim 10, further comprising: a first nonvolatile memory configured to store a black selection enable signal and a set black value input from the host; and a second nonvolatile memory configured to store a module black value set by the driving controller, wherein the selection signal is to select one of the set black value and the module black value in response to the black selection enable signal. ### Claim 20 (depends on 19) The display apparatus of claim 19, wherein: the first nonvolatile memory is a flash memory, and the second nonvolatile memory include an one time programmable memory.