# US 8,542,257 B2 · Method of driving a light source, apparatus for performing the method and display apparatus having the apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,542,257 B2 - Document ID: US8542257B2 - Status: Granted - Kind: B2 - Application number: 12/639,844 - Filed: 2009-12-16 - Published: 2010-07-29 - Granted: 2013-09-24 - Earliest claimed: 2009-01-23 - Assignees: Samsung Display Co., Ltd. - Applicants: Bo-Young An; Joo-Hyung Lee; Se-Byung Chae; Ho-Suk Maeng; Seung-Bin Moon - Inventors: Bo-Young An; Joo-Hyung Lee; Se-Byung Chae; Ho-Suk Maeng; Seung-Bin Moon - Web page: https://patentgrep.com/patent/US8542257B2 ## CPC - G09G 3/342: {using several illumination sources separately controlled corresponding to different display panel areas, e.g. along one dimension such as lines} - G09G 3/3648: {using an active matrix (G09G3/367 - G09G3/3696 take precedence)} - G09G 2340/06: Colour space transformation - G09G 2360/144: the light being ambient light - 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 light source apparatus includes a light source module, a luminance determiner, an illuminance sensor and a light source driver. The light source module provides a display panel with light. The luminance determiner obtains luminance data of first image data including at least white image data that is converted from image data of a red color, a green color and a blue color. The illuminance sensor obtains sensing data based upon an external illuminance. The light source driver drives the light source module based upon the luminance data and the sensing data. ## Claims ### Claim 1 A method of driving a light source, the method comprising: converting primary image data of a red color, a green color and a blue color into first image data including at least white image data; obtaining luminance data of the first image data; mapping external illuminance data to obtain sensing data using a lookup table configured to overlap increased external illuminance data with decreased external illuminance data for preventing flicker; and driving a light source module that provides a display panel with light based upon the luminance data and the sensing data. ### Claim 2 (depends on 1) The method of claim 1, wherein driving a light source module comprises: obtaining driving data by multiplying the luminance data by the sensing data; and generating a driving signal having a pulse width based upon the driving data to provide the light source module with the driving signal having a pulse width. ### Claim 3 A method of driving a light source, the method comprising: converting primary image data of a red color, a green color and a blue color into first image data including at least white image data; obtaining luminance data of the first image data; obtaining sensing data based upon an external illuminance; and driving a light source module that provides a display panel with light based upon the luminance data and the sensing data, wherein driving a light source module comprises: obtaining driving data by multiplying the luminance data by the sensing data; and generating a driving signal having a pulse width based upon the driving data to provide the light source module with the driving signal having a pulse width, and wherein obtaining the driving data comprises: removing a least significant bit of the driving data such that the amplitude of the driving data is obtained from the luminance data and the sensing data. ### Claim 4 (depends on 2) The method of claim 2, wherein obtaining the driving data comprises: determining the driving data in accordance with an external input signal. ### Claim 5 (depends on 4) The method of claim 4, wherein determining the driving data further comprises: maintaining driving data of a minimum level when the external input signal is lower than driving data of the minimum level. ### Claim 6 (depends on 1) The method of claim 1, wherein obtaining the sensing data comprises: obtaining at least one illuminance signal by measuring an illuminance of an external environment; converting the at least one illuminance signal having analog value to illuminance data having digital value; selecting a representative value of the illuminance data; and obtaining the sensing data corresponding to the representative value of the illuminance data. ### Claim 7 A light source apparatus comprising: a light source module that provides a display panel with light; a luminance determiner that obtains luminance data of first image data that includes at least white image data that is converted from image data of a red color, a green color and a blue color; an illuminance sensor that obtains sensing data based upon an external illuminance; and a light source driver that drives the light source module based upon the luminance data and the sensing data, wherein the illuminance sensor comprises a lookup table configured to overlap increased external illuminance data with decreased external illuminance data for preventing flicker when mapping the sensing data based upon the external illuminance. ### Claim 8 (depends on 7) The light source apparatus of claim 7, wherein the light source driver comprises: a calculating unit that obtains driving data by multiplying the luminance data by the sensing data; and a pulse width generating unit that generates a driving signal having a pulse width based upon the driving data to provide the light source module with the driving signal having a pulse width. ### Claim 9 A light source apparatus comprising: a light source module that provides a display panel with light; a luminance determiner that obtains luminance data of first image data that includes at least white image data that is converted from image data of a red color, a green color and a blue color; an illuminance sensor that obtains sensing data based upon an external illuminance; and a light source driver that drives the light source module based upon the luminance data and the sensing data, wherein the light source driver comprises: a calculating unit that obtains driving data by multiplying the luminance data by the sensing data; and a pulse width generating unit that generates a driving signal having a pulse width based upon the driving data to provide the light source module with the driving signal having a pulse width, and wherein the calculating unit is configured to remove a least significant bit of the driving data to obtain the amplitude of the driving data from the luminance data and the sensing data. ### Claim 10 (depends on 8) The light source apparatus of claim 8, wherein the light source driver further comprises a user adjusting unit that determines the driving data in accordance with an external input signal. ### Claim 11 (depends on 10) The light source apparatus of claim 10, wherein the light source driver further comprises a minimum level maintenance unit that maintains driving data of a minimum level when the external input signal is no higher than driving data of the minimum level. ### Claim 12 (depends on 9) The light source apparatus of claim 9, wherein the light source driver further comprises a user adjusting unit that determines the driving data in accordance with an external input signal. ### Claim 13 (depends on 12) The light source apparatus of claim 12, wherein the light source driver further comprises a minimum level maintenance unit that maintains driving data of a minimum level when the external input signal is no higher than driving data of the minimum level. ### Claim 14 (depends on 7) The light source apparatus of claim 7, wherein the illuminance sensor comprises: a sensing unit that obtains a plurality of illuminance signals by measuring an illuminance of an external environment; an analog-to-digital converter that converts the illuminance signal having analog value into illuminance data having digital value; a selection unit that selects a representative value of the illuminance data; and a mapping unit that outputs to the light source driver sensing data corresponding to the representative value of the illuminance data. ### Claim 15 (depends on 14) The light source apparatus of claim 14, wherein the illuminance sensor further comprises: a filtering unit that removes a noise component of the illuminance data to provide the selection unit with the illuminance data in which a noise component is removed. ### Claim 16 A display apparatus comprising: a display panel comprising at least a white pixel; a panel driver that converts primary image data of a red color, a green color and a blue color into first image data including at least white image data to drive the display panel; and a light source apparatus comprising: a light source module that provides the display panel with light; a luminance determiner that obtains luminance data of the first image data; an illuminance sensor that obtains sensing data based upon an external illuminance; and a light source driver that drives the light source module based upon the luminance data and the sensing data, wherein the illuminance sensor comprises a lookup table configured to overlap increased external illuminance data with decreased external illuminance data for preventing flicker when mapping the sensing data based upon the external illuminance. ### Claim 17 (depends on 16) The display apparatus of claim 16, wherein the light source driver comprises: a calculating unit that obtains driving data by multiplying the luminance data by the sensing data; and a pulse width generating unit that generates a driving signal having a pulse width based upon the driving data to provide the light source module with the driving signal having a pulse width. ### Claim 18 A display apparatus comprising: a display panel comprising at least a white pixel; a panel driver that converts primary image data of a red color, a green color and a blue color into first image data including at least white image data to drive the display panel; and a light source apparatus comprising: a light source module that provides the display panel with light; a luminance determiner that obtains luminance data of the first image data; an illuminance sensor that obtains sensing data based upon an external illuminance; and a light source driver that drives the light source module based upon the luminance data and the sensing data, wherein the light source driver comprises: a calculating unit that obtains driving data by multiplying the luminance data by the sensing data and a pulse width generating unit that generates a driving signal having a pulse width based upon the driving data to provide the light source module with the driving signal having a pulse width, and wherein the calculating unit removes a least significant bit of the driving data to obtain the amplitude of the driving data from the luminance data and the sensing data. ### Claim 19 (depends on 17) The display apparatus of claim 17, wherein the illuminance sensor comprises: a sensing unit that obtains a plurality of illuminance signals by measuring an illuminance of an external environment; an analog-to-digital converter that converts the illuminance signal having into illuminance data having digital value; a selection unit that selects a representative value of the illuminance data; and a mapping unit that includes the lookup table and that outputs sensing data corresponding to the representative value of the illuminance data to the light source driver. ### Claim 20 (depends on 19) The display apparatus of claim 19, wherein the sensing unit comprises at least one illuminance sensor mounted on the display panel.