# US 10,121,444 B2 · Display panel driving apparatus, display and method for correcting positive and negative polarity grayscale voltage > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,121,444 B2 - Document ID: US10121444B2 - Status: Granted - Kind: B2 - Application number: 15/082,650 - Filed: 2016-03-28 - Published: 2017-03-23 - Granted: 2018-11-06 - Earliest claimed: 2015-09-23 - Assignees: Samsung Display Co., Ltd. - Applicants: Samsung Display Co., LTD. - Inventors: Hyong-Do Choi; Yun-Nam Kim - Web page: https://patentgrep.com/patent/US10121444B2 ## CPC - G09G 3/3688: {suitable for active matrices only} - G09G 3/3611: {Control of matrices with row and column drivers} - G09G 3/3614: {Control of polarity reversal in general} - G09G 3/3696: {Generation of voltages supplied to electrode drivers} - G09G 2310/0243: Details of the generation of driving signals - G09G 2310/0291: Details of output amplifiers or buffers arranged for use in a driving circuit - G09G 2320/0247: Flicker reduction other than flicker reduction circuits used for single beam cathode-ray tubes - G09G 2320/04: Maintaining the quality of display appearance - 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 display panel driving apparatus includes a grayscale voltage outputting part which generates a first positive polarity grayscale voltage and a first polarity negative grayscale voltage, compares the first positive polarity with a first reference voltage to output a first comparison voltage, compares the first negative polarity grayscale voltage with a second reference voltage to output a second comparison voltage, compares the first comparison voltage with the second comparison voltage to output a voltage deviation value, and outputs a second positive polarity grayscale voltage and a second negative polarity grayscale voltage based on the voltage deviation value, and a data driving part which outputs a data signal based on image data to a data line of a display panel, using the second positive polarity grayscale voltage and the second negative polarity grayscale voltage. ## Claims ### Claim 1 A display apparatus comprising: a display panel which displays an image and comprising a gate line and a data line; and a display apparatus comprising a grayscale voltage outputting part which generates a first positive polarity grayscale voltage and a first negative polarity grayscale voltage, compares the first positive polarity with a first reference voltage to output a first comparison voltage, compares the first negative polarity grayscale voltage with a second reference voltage to output a second comparison voltage, compares the first comparison voltage with the second comparison voltage to output a voltage deviation value, and outputs a second positive polarity grayscale voltage and a second negative polarity grayscale voltage based on the voltage deviation value, a data driving part which outputs a data signal based on image data to the data line of the display panel, using the second positive polarity grayscale voltage and the second negative polarity grayscale voltage, and a gate driving part which outputs a gate signal to the gate line of the display panel. ### Claim 2 (depends on 1) The display apparatus of claim 1, further comprising: a timing controlling part which controls a timing of the data driving part and a timing of the gate driving part, receives a feedback signal based on the second positive polarity grayscale voltage and the second negative polarity grayscale voltage, and outputs a grayscale voltage control signal for controlling the first positive polarity grayscale voltage and the first negative polarity grayscale voltage to the grayscale voltage outputting part, wherein the grayscale voltage outputting part receives a vertical start signal from the timing controlling part and outputs the second positive polarity grayscale voltage and the second negative polarity grayscale voltage in a frame period. ### Claim 3 (depends on 1) The display apparatus of claim 1, wherein the grayscale voltage outputting part comprises: a grayscale voltage generating part which outputs the first positive polarity grayscale voltage and the first negative polarity grayscale voltage; and a grayscale voltage adjusting part which outputs the second positive polarity grayscale voltage and the second negative polarity grayscale voltage of which absolute values are the same, based on the first positive polarity grayscale voltage, the first negative polarity grayscale voltage, the first reference voltage, the second reference voltage, a positive polarity driving voltage and a negative polarity driving voltage. ### Claim 4 (depends on 3) The display apparatus of claim 3, wherein each of the first reference voltage and the second reference voltage is a ground voltage. ### Claim 5 (depends on 4) The display apparatus of claim 4, wherein the grayscale voltage adjusting part comprises: a first comparing part which compares the first positive polarity grayscale voltage with the ground voltage to output a positive polarity grayscale voltage absolute value; a second comparing part which compares the first negative polarity grayscale voltage with the ground voltage to output a negative polarity grayscale voltage absolute value; a third comparing part which compares the positive polarity grayscale voltage absolute value with the negative polarity grayscale voltage absolute value to output the voltage deviation value; and a resistor part which controls a resistance based on the voltage deviation value and outputs the second positive polarity grayscale voltage and the second negative polarity grayscale voltage. ### Claim 6 (depends on 5) The display apparatus of claim 5, wherein the first comparing part comprises an operational amplifier including a first terminal which receives the first positive polarity grayscale voltage, a second terminal which receives the ground voltage, a third terminal which receives the positive polarity driving voltage, a fourth terminal which receives the negative polarity driving voltage, and a fifth terminal which outputs the positive polarity grayscale voltage absolute value. ### Claim 7 (depends on 5) The display apparatus of claim 5, wherein the second comparing part comprises an operational amplifier including a first terminal which receives the ground voltage, a second terminal which receives the first negative polarity grayscale voltage, a third terminal which receives the positive polarity driving voltage, a fourth terminal which receives the negative polarity driving voltage, and a fifth terminal which outputs the negative polarity grayscale voltage absolute value. ### Claim 8 (depends on 5) The display apparatus of claim 5, wherein the third comparing part comprises an operational amplifier including a first terminal which receives the positive polarity grayscale voltage absolute value, a second terminal which receives the negative polarity grayscale voltage absolute value, a third terminal which receives the positive polarity driving voltage, a fourth terminal which receives the negative polarity driving voltage, and a fifth terminal which outputs the voltage deviation value. ### Claim 9 (depends on 5) The display apparatus of claim 5, wherein the resistor part comprises a variable resistor of which the resistance is controlled according to the voltage deviation value. ### Claim 10 (depends on 1) The display apparatus of claim 1, wherein the grayscale voltage outputting part comprises: a grayscale voltage generating part which outputs the first positive polarity grayscale voltage and the first negative polarity grayscale voltage; and a grayscale voltage adjusting part which outputs the second positive polarity grayscale voltage and the second negative polarity grayscale voltage of which absolute values are different, based on the first positive polarity grayscale voltage, the first negative polarity grayscale voltage, a positive polarity driving voltage and a negative polarity driving voltage. ### Claim 11 (depends on 10) The display apparatus of claim 10, wherein the first reference voltage is a first offset voltage and the second reference voltage is a second offset voltage, and wherein the grayscale voltage adjusting part comprises: a first comparing part which compares the first positive polarity grayscale voltage with the first offset voltage to output the first comparison voltage; a second comparing part which compares the first negative polarity grayscale voltage with the second offset voltage to output the second comparison voltage; a third comparing part which compares the first comparison voltage with the second comparison voltage to output the voltage deviation value; and a resistor part which controls a resistance based on the voltage deviation value and outputs the second positive polarity grayscale voltage and the second negative polarity grayscale voltage. ### Claim 12 (depends on 11) The display apparatus of claim 11, wherein the first comparing part comprises an operational amplifier including a first terminal which receives the first positive polarity grayscale voltage, a second terminal which receives the first offset voltage, a third terminal which receives the positive polarity driving voltage, a fourth terminal which receives the negative polarity driving voltage, and a fifth terminal which outputs the first comparison voltage. ### Claim 13 (depends on 11) The display apparatus of claim 11, wherein the second comparing part comprises an operational amplifier including a first terminal which receives the second offset voltage, a second terminal which receives the first negative polarity grayscale voltage, a third terminal which receives the positive polarity driving voltage, a fourth terminal which receives the negative polarity driving voltage, and a fifth terminal which outputs the second comparison voltage. ### Claim 14 (depends on 11) The display apparatus of claim 11, wherein the third comparing part comprises an operational amplifier including a first terminal which receives the first comparison voltage, a second terminal which receives the second comparison voltage, a third terminal which receives the positive polarity driving voltage, a fourth terminal which receives the negative polarity driving voltage, and a fifth terminal which outputs the voltage deviation value. ### Claim 15 (depends on 14) The display apparatus of claim 14, wherein the resistor part comprises a variable resistor of which the resistance is controlled according to the voltage deviation value. ### Claim 16 (depends on 11) The display apparatus of claim 11, wherein the grayscale voltage adjusting part further comprises: a first offset voltage part which outputs the first offset voltage; and a second offset voltage part which outputs the second offset voltage. ### Claim 17 (depends on 16) The display apparatus of claim 16, wherein the first offset voltage part comprises: a first resistor connected between the first comparing part and a terminal to which a ground voltage is applied; a first positive polarity resistor connected between the first resistor and a terminal to which the positive polarity driving voltage is applied; and a first negative polarity resistor connected between the first resistor and a terminal to which the negative polarity driving voltage is applied. ### Claim 18 (depends on 16) The display apparatus of claim 16, wherein the second offset voltage part comprises: a second resistor connected between the second comparing part and a terminal to which a ground voltage is applied; a second positive polarity resistor connected between the second resistor and a terminal to which the positive polarity driving voltage is applied; and a second negative polarity resistor connected between the second resistor and a terminal to which the negative polarity driving voltage is applied.