# US 8,542,175 B2 · Flexible control of charge share in display panel > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,542,175 B2 - Document ID: US8542175B2 - Status: Granted - Kind: B2 - Application number: 13/051,238 - Filed: 2011-03-18 - Published: 2011-07-07 - Granted: 2013-09-24 - Earliest claimed: 2004-11-15 - Assignees: Samsung Electronics Co., Ltd. - Applicants: Kyung-Wol Kim; Yong-Weon Jeon; Jong-Hoon Hong - Inventors: Kyung-Wol Kim; Yong-Weon Jeon; Jong-Hoon Hong - Web page: https://patentgrep.com/patent/US8542175B2 ## CPC - G09G 3/3685: {Details of drivers for data electrodes} - G09G 2310/0248: Precharge or discharge of column electrodes before or after applying exact column voltages - G09G 2310/0251: Precharge or discharge of pixel before applying new pixel voltage - G09G 2310/027: Details of drivers for data electrodes, the drivers handling digital grey scale data, e.g. use of D/A converters - G09G 2320/0252: Improving the response speed - G09G 2330/021: Power management, e.g. power saving - 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 source driver of a display panel includes a channel state signal generator, first switches, and second switches. The channel state signal generator generates first and second channel state signals that are each activated for a respective time period depending on adjustable state length data. The first switches are opened for uncoupling channel output signals from source lines of the display panel when the first channel state signal is activated. The second switches are closed for coupling together the source lines of the display panel for charge sharing when the second channel state signal is activated. ## Claims ### Claim 1 A source driver of a display panel, comprising: a channel state signal generator for generating a first channel state signal that is at a first logic state for a time period depending on an adjustable state length data and for generating a second channel state signal that is at a second logic state within the time period when the first channel state signal is at the first logic state; a plurality of first switches that are opened for uncoupling channel output signals from source lines of the display panel when the first channel state signal is at the first logic state; and a plurality of second switches that are closed for coupling together the source lines of the display panel when the second channel state signal is at the second logic state; wherein the second switches are not closed simultaneously with the first switches being closed. ### Claim 2 (depends on 1) The source driver of claim 1, wherein the channel state signal generator includes: a register for storing the state length data; a counter for counting a number of cycles of a clock signal from when a load signal is activated; a comparator for activating a reset signal when the state length data and the counted number of cycles of the clock signal are substantially equal; and an output unit for generating the second channel state signal that is set to the second logic state after the counter begins counting the number of cycles of the clock signal and until an end of activating the reset signal. ### Claim 3 (depends on 2) The source driver of claim 2, wherein the output unit generates the first channel state signal that is set to the first logic state after the load signal is activated and until after the end of activating the reset signal. ### Claim 4 (depends on 2) The source driver of claim 2, wherein the state length data is provided to the source driver from an external device independent of the load signal. ### Claim 5 (depends on 1) The source driver of claim 1, further comprising: a plurality of driving circuits for generating the channel output signals from color image data for the display panel. ### Claim 6 (depends on 5) The source driver of claim 5, wherein the state length data is input as part of at least one color image data during a time when the color image data is not latched by the driving circuits. ### Claim 7 (depends on 1) The source driver of claim 1, wherein the display panel is for a TFT-LCD (Thin Film Transistor-Liquid Crystal Display). ### Claim 8 A source driver of a display panel, comprising: means for generating a first channel state signal that is at a first logic state for a time period depending on an adjustable state length data; means for uncoupling channel output signals from source lines of the display panel when the first channel state signal is at the first logic state; means for generating a second channel state signal that is at a second logic state within the time period when the first channel state signal is at the first logic state; and means for coupling together the source lines of the display panel when the second channel state signal is at the second logic state; wherein the first channel state signal is not at a same logic state with the second channel state signal. ### Claim 9 (depends on 8) The source driver of claim 8, further comprising: means for setting the first channel state signal to the first logic state for the time period after activation of a load signal for the display device. ### Claim 10 (depends on 9) The source driver of claim 9, further comprising: means for inputting the state length data from an external device independent of the load signal. ### Claim 11 (depends on 8) The source driver of claim 8, further comprising: means for generating the channel output signals from image data for the display panel. ### Claim 12 A method of driving a display panel, comprising: inputting an adjustable state length data; generating a first channel state signal that is at a first logic state for a time period depending on the state length data; uncoupling channel output signals from source lines of the display panel when the first channel state signal is at the first logic state; generating a second channel state signal that is at a second logic state within the time period when the first channel state signal is at the first logic state; and coupling together the source lines of the display panel when the second channel state signal is activated at the second logic state; wherein the second switches are not closed simultaneously with the first switches being closed. ### Claim 13 (depends on 12) The method of claim 12, further comprising: setting the first channel state signal to the first logic state after activation of a load signal; and inputting the state length data from an external device independent of the load signal. ### Claim 14 (depends on 12) The method of claim 12, further comprising: generating the channel output signals from color image data for the display panel; and inputting the state length data as part of at least one color image data during a time when the color image data is not being latched for generating gray voltages. ### Claim 15 (depends on 12) The method of claim 12, wherein the display panel is for a TFT-LCD (Thin Film Transistor-Liquid Crystal Display).