# US 2017/0287431 A1 · Electrooptical device, control method of electrooptical device and electronic device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2017/0287431 A1 - Document ID: US20170287431A1 - Status: Published application - Kind: A1 - Application number: 15/467,043 - Filed: 2017-03-23 - Published: 2017-10-05 - Earliest claimed: 2016-04-04 - Assignees: Seiko Epson Corporation - Applicants: Seiko Epson Corporation - Inventors: Shinta ENAMI - Web page: https://patentgrep.com/patent/US20170287431A1 ## CPC - G09G 3/3688: {suitable for active matrices only} - G09G 3/3648: {using an active matrix (G09G3/367 - G09G3/3696 take precedence)} - G09G 2310/0245: Clearing or presetting the whole screen independently of waveforms, e.g. on power-on (G09G2310/063 takes precedence) - G09G 2310/027: Details of drivers for data electrodes, the drivers handling digital grey scale data, e.g. use of D/A converters - G09G 2310/0297: Special arrangements with multiplexing or demultiplexing of display data in the drivers for data electrodes, in a pre-processing circuitry delivering display data to said drivers or in the matrix panel, e.g. multiplexing plural data signals to one D/A converter or demultiplexing the D/A converter output to multiple columns - 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 An image signal with a magnitude in accordance with a tone to be displayed is supplied to pixels via data lines in a tone display period, and a precharge voltage including a low-potential second voltage and a high-potential second voltage is supplied to the data lines in a precharge period before the tone display period. Control is made such that a first pattern in which the low-potential second voltage and the high-potential second voltage are sequentially output in the precharge period in one horizontal scanning period and a second pattern in which only the high-potential second voltage is output in the precharge period in one horizontal scanning period are switched in accordance with a selected scanning line. Also, control is made such that a supply period of the high-potential second voltage in the second pattern is shorter than a supply period of the high-potential second voltage in the first pattern. ## Claims ### Claim 1 An electrooptical device comprising: a plurality of scanning lines; a plurality of data lines; pixels that are provided so as to correspond to intersections between the plurality of scanning lines and the plurality of data lines; a scanning line drive unit that supplies a scanning signal to the scanning lines; a data line drive unit that supplies a first voltage with a magnitude in accordance with a tone to be displayed to the pixels via the data lines in a first period and supplies a second voltage including a low-potential second voltage and a high-potential second voltage to the data lines in a second period before the first period; and a control unit that controls the data line drive unit such that a first pattern in which the low-potential second voltage and the high-potential second voltage are sequentially output in the second period in one horizontal scanning period and a second pattern in which only the high-potential second voltage is output in the second period in one horizontal scanning period are switched in accordance with a selected scanning line, wherein the control unit controls the data line drive unit such that a supply period of the high-potential second voltage in the second pattern is shorter than a supply period of the high-potential second voltage in the first pattern. ### Claim 2 (depends on 1) The electrooptical device according to claim 1, wherein the data line drive unit includes a voltage amplification unit and a D/A conversion unit. ### Claim 3 (depends on 1) The electrooptical device according to claim 1, wherein the first period includes a tone display period, the second period includes a fly-back period, and the second voltage includes a precharge voltage. ### Claim 4 (depends on 1) The electrooptical device according to claim 1, further comprising: a data line selection unit that is provided between the data line drive unit and the data lines and selects the data lines in a time division manner. ### Claim 5 A control method of an electrooptical device that includes a plurality of scanning lines, a plurality of data lines, and pixels that are provided so as to correspond to the respective intersections between the plurality of scanning lines and the plurality of data lines, the method comprising: supplying a scanning signal to the scanning lines; supplying a first voltage with a magnitude in accordance with a tone to be displayed to the pixels via the data lines in a first period; supplying a second voltage including a low-potential second voltage and a high-potential second voltage to the data lines in a second period before the first period; and switching a first pattern in which the low-potential second voltage and the high-potential second voltage are sequentially output in the second period in one horizontal scanning period and a second pattern in which only the high-potential second voltage is output in the second period in one horizontal scanning period in accordance with a selected scanning line, wherein a supply period of the high-potential second voltage in the second pattern is shorter than a supply period of the high-potential second voltage in the first pattern. ### Claim 6 (depends on 5) The control method of an electrooptical device according to claim 5, wherein digital data that represents a tone is converted into the analog first voltage and is then supplied to the data lines in the first period, and digital data that represents the second voltage is converted into the analog second voltage and is then supplied to the data lines in the second period. ### Claim 7 (depends on 5) The control method of an electrooptical device according to claim 5, wherein the first period includes a tone display period, the second period includes a fly-back period, and the second voltage includes a precharge voltage. ### Claim 8 (depends on 1) An electronic device comprising: the electrooptical device according to claim 1.