# US 8,570,246 B2 · Light source system for a color flat panel display > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,570,246 B2 - Document ID: US8570246B2 - Status: Granted - Kind: B2 - Application number: 13/342,494 - Filed: 2012-01-03 - Published: 2012-05-03 - Granted: 2013-10-29 - Earliest claimed: 2001-05-15 - Assignees: BlackBerry Limited - Applicants: Robert J. Lowles; James Alexander Robinson - Inventors: Robert J. Lowles; James Alexander Robinson - Web page: https://patentgrep.com/patent/US8570246B2 ## CPC - G09G 3/3607: {for displaying colours or for displaying grey scales with a specific pixel layout, e.g. using sub-pixels (display of colours in flat matrix panels other than liquid crystal displays G09G3/2003; grey scales specific for television H04N3/127)} - G09G 3/3406: {Control of illumination source (illumination devices structurally associated with liquid crystal cells G02F1/1336)} - G09G 2300/0456: with a reflective area and a transmissive area combined in one pixel, such as in transflectance pixels - G09G 2320/0271: Adjustment of the gradation levels within the range of the gradation scale, e.g. by redistribution or clipping - G09G 2320/0606: Manual adjustment - G09G 2320/0626: for control of overall brightness - G09G 2340/0428: Gradation resolution change - G09G 2340/14: Solving problems related to the presentation of information to be displayed - 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 system for operating a color flat panel display (FPD) is provided that includes a color FPD, a light source, and a display processing device. The color FPD has an adjustable color depth and is configured to reflect ambient light. The light source transmits light through the bottom surface of the color FPD. The display processing device is coupled to the color FPD and decreases the color depth of the color FPD when the light source is activated and increases the color depth of the color FPD when the light source is turned off. ## Claims ### Claim 1 A method of operating a color flat panel display that is configured to be illuminated by a light source and a reflector, comprising: controlling the light source of the color flat panel display to one of activate and deactivate; decreasing, by a controller, a color depth of the color flat panel display, from a larger set of colors to a smaller set of colors, in response to activating the light source; and increasing, by the controller, the color depth, from the smaller set of colors, in response to deactivating the light source. ### Claim 2 (depends on 1) The method of claim 1 wherein the automatically increasing includes increasing the color depth to a level that was previously selectively adjusted by a user. ### Claim 3 (depends on 1) The method of claim 1 wherein the controlling includes activating the light source in response to receiving a preselected input from a user interface. ### Claim 4 (depends on 1) The method of claim 1 wherein the controlling includes deactivating the light source in response to receiving an input from a user interface. ### Claim 5 (depends on 1) The method of claim 1 wherein the controlling includes deactivating the light source in response to not receiving an input from a user interface for a predetermined time period. ### Claim 6 (depends on 1) The method of claim 1 wherein the light source is an electroluminescent (EL) light source. ### Claim 7 A method of operating a color flat panel display that is configured to be illuminated by a light source and a reflector, comprising: controlling the light source of the color flat panel display to one of activate and deactivate; decreasing, by a controller, a color depth of the color flat panel display, from a larger set of colors to a smaller set of colors, in response to activating the light source; and increasing, by the controller, the color depth, from the smaller set of colors, in response to deactivating the light source; wherein the automatically decreasing includes decreasing the color depth to eight colors. ### Claim 8 A method of operating a color flat panel display that is configured to be illuminated by a light source and a reflector, comprising: controlling the light source of the color flat panel display to one of activate and deactivate; decreasing, by a controller, a color depth of the color flat panel display, from a larger set of colors to a smaller set of colors, in response to activating the light source; increasing, by the controller, the color depth, from the smaller set of colors, in response to deactivating the light source; and increasing, by the controller, displayed font size in response to activating the light source and decreasing, by the controller, the displayed font size in response to deactivating the light source. ### Claim 9 A method of operating a color flat panel display that is configured to be illuminated by a light source and a reflector, comprising: controlling the light source of the color flat panel display to one of activate and deactivate; increasing, by a controller, displayed font size in response to activating the light source; and decreasing, by the controller, the displayed font size in response to deactivating the light source. ### Claim 10 (depends on 9) The method of claim 9 wherein the controlling includes activating the light source in response to receiving a preselected input from a user interface. ### Claim 11 (depends on 10) The method of claim 10 further comprising increasing, by the controller, the displayed font size further in response to receiving the preselected input again from the user interface. ### Claim 12 (depends on 9) The method of claim 9 wherein the controlling includes deactivating the light source in response to receiving an input from a user interface. ### Claim 13 (depends on 9) The method of claim 9 wherein the controlling includes deactivating the light source in response to not receiving an input from a user interface for a predetermined period. ### Claim 14 (depends on 9) The method of claim 9 wherein the light source is an electroluminescent (EL) light source. ### Claim 15 A mobile device comprising: a color flat panel display; a light source for illuminating the display; a reflector for illuminating the display; and a display controller configured to control the light source to one of activate and deactivate; decrease a color depth of the display, from a larger set of colors to a smaller set of colors, in response to activating the light source; and increase the color depth, from the smaller set of colors, in response to deactivating the light source. ### Claim 16 (depends on 15) The mobile device of claim 15 further comprising a user interface, and wherein the display controller is configured to activate the light source in response to receiving a preselected input from a user interface. ### Claim 17 (depends on 15) The mobile device of claim 15 wherein the light source is an electroluminescent (EL) light source. ### Claim 18 A mobile device comprising: a color flat panel display; a light source for illuminating the display; a reflector for illuminating the display; and a display controller configured to control the light source to one of activate and deactivate; decrease a color depth of the display, from a larger set of colors to a smaller set of colors, in response to activating the light source; and increase the color depth, from the smaller set of colors, in response to deactivating the light source; wherein the display controller is further configured to increase displayed font size in response to activating the light source. ### Claim 19 A mobile device comprising: a color flat panel display; a light source for illuminating the display; a reflector for illuminating the display; and a display controller configured to control the light source to one of activate and deactivate; decrease a color depth of the display, from a larger set of colors to a smaller set of colors, in response to activating the light source; and increase the color depth, from the smaller set of colors, in response to deactivating the light source; wherein the display controller is further configured to decrease the displayed font size in response to deactivating the light source.