# US 2013/0278641 A1 · Method, system and apparatus for power saving backlight > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2013/0278641 A1 - Document ID: US20130278641A1 - Status: Published application - Kind: A1 - Application number: 13/785,935 - Filed: 2013-03-05 - Published: 2013-10-24 - Earliest claimed: 2009-09-11 - Inventors: Marc ALBRECHT; Chihao XU; Andreas KARRENBAUER - Web page: https://patentgrep.com/patent/US20130278641A1 ## 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 3/3426: {the different display panel areas being distributed in two dimensions, e.g. matrix} - G09G 3/3406: {Control of illumination source (illumination devices structurally associated with liquid crystal cells G02F1/1336)} - G09G 2320/0233: Improving the luminance or brightness uniformity across the screen - G09G 2320/0633: by amplitude modulation of the brightness of the illumination source - G09G 2330/021: Power management, e.g. power saving - G09G 2330/08: Fault-tolerant or redundant circuits, or circuits in which repair of defects is prepared - G09G 2360/16: Calculation or use of calculated indices related to luminance levels in display data - 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 method, apparatus, and system for displaying an image on a liquid crystal display (LCD). The method, apparatus, and system can include condensing a plurality of pixel gray values to a concentrated pixel, the concentrated pixel assigned to a geometric position on a display and described by at least one of a plurality of parameters and gray value; forming the concentrated pixels to a condensed image; resolving a light spread function of a first LED in substantially the same resolution as the condensed image; calculating a backlight needed based on the condensed image; and optimizing a value of a plurality of LEDs by considering the contribution of the plurality of LEDs on the concentrated pixel, wherein light spread functions of the LEDs are used. ## Claims ### Claim 1 A method of lighting a liquid crystal display, comprising: condensing a plurality of pixel gray values to a concentrated pixel, the concentrated pixel assigned to a geometric position on a display and described by at least one of a plurality of parameters and gray value; forming the concentrated pixels to a condensed image; resolving a light spread function of a first LED in substantially the same resolution as the condensed image; calculating a backlight needed based on the condensed image; and optimizing a value of a plurality of LEDs by considering the contribution of the plurality of LEDs on the concentrated pixel, wherein light spread functions of the LEDs are used. ### Claim 2 (depends on 1) The method of lighting a liquid crystal display of claim 1, wherein a segment to be condensed is a rectangle array containing a plurality of pixels. ### Claim 3 (depends on 1) The method of lighting a liquid crystal display of claim 1, wherein at least one dimension of a plurality of condensed segments on a display is a binary round number. ### Claim 4 (depends on 1) The method of lighting a liquid crystal display of claim 1, wherein a filter function is applied for condensing pixel gray values. ### Claim 5 (depends on 1) The method of lighting a liquid crystal display of claim 1, further comprising utilizing a plurality of condensing functions in one local dimming processing unit. ### Claim 6 (depends on 1) The method of lighting a liquid crystal display of claim 1, wherein a resolution of the condensed image is higher than the number of LEDs ### Claim 7 (depends on 1) The method of lighting a liquid crystal display of claim 1, further comprising assigning a plurality of concentrated pixels to an individual LED. ### Claim 8 (depends on 1) The method of lighting a liquid crystal display of claim 1, further comprising storing the condensed image in a memory of the local dimming processing unit ### Claim 9 (depends on 8) The method of lighting a liquid crystal display of claim 8, further comprising performing iterations for calculating LED values and reading the stored, condensed image stored at least one time within a frame period. ### Claim 10 (depends on 1) The method of lighting a liquid crystal display of claim 1, further designating a start value for the plurality of LEDs without consideration of contribution of other LEDs in the plurality of LEDs and using a decrease approach to determine final LED values of the plurality of LEDs by considering the contribution of a number of LEDs on the backlight behind concentrated pixels. ### Claim 11 (depends on 10) The method of lighting a liquid crystal display of claim 10, further comprising using further iteration approaches that vary LED values by one of an increase approach, a decrease approach or a combination of an increase approach and a decrease approach to substantially fill the backlight requirement given by the condensed image. ### Claim 12 (depends on 1) The method of lighting a liquid crystal display of claim 1, further comprising successively increasing a gray value of a concentrated pixel to a 100% value for the concentrated pixel during the iterations. ### Claim 13 (depends on 1) The method of lighting a liquid crystal display of claim 1, further comprising scanning the concentrated pixels in dependence on their positions. ### Claim 14 (depends on 1) The method of lighting a liquid crystal display of claim 1, wherein an arrangement of the LED backlight is edge-lit. ### Claim 15 (depends on 1) The method of lighting a liquid crystal display of claim 1, wherein the light spread function considers characteristics of at least one of a one-dimensional structure of an LED bar, reflection stripes on edges of a panel of the display and imperfect properties of light guide. ### Claim 16 (depends on 1) The method of lighting a liquid crystal display of claim 1, wherein the light spread functions are stored in a memory. ### Claim 17 A liquid crystal display module, comprising: a liquid crystal display with a plurality of pixels to display an image; a backlight with a plurality of LEDs; and a processor that condenses a plurality of pixel gray values to a concentrated pixel, assigns the concentrated pixel assigned to a geometric position on a display described by at least one of a plurality of parameters and gray value, forms the concentrated pixels to a condensed image, resolves a light spread function of a first LED in substantially the same resolution as the condensed image, calculates a backlight needed based on the condensed image, and optimizes a value of a plurality of LEDs by considering the contribution of the plurality of LEDs on the concentrated pixel, wherein light spread functions of the LEDs are used. ### Claim 18 (depends on 17) The lighting a liquid crystal display of claim 17, wherein the processor further designates a start value for the plurality of LEDs without consideration of contribution of other LEDs in the plurality of LEDs and uses a decrease approach to determine final LED values of the plurality of LEDs by considering the contribution of a number of LEDs on the backlight behind concentrated pixels. ### Claim 19 (depends on 17) The liquid crystal display of claim 17, wherein the processor uses further iteration approaches that vary LED values by one of an increase approach, a decrease approach or a combination of an increase approach and a decrease approach to substantially fill the backlight requirement given by the condensed image. ### Claim 20 A system for producing an image with a liquid crystal display, comprising: a plurality of pixels that display an image on a liquid crystal display; a backlight having a plurality of LEDs that light the liquid crystal pixels; a processing unit with an access to the image data to be displayed; and an LED driver circuit which receives LED control signals from the processing unit that condenses a plurality of pixel gray values to a concentrated pixel, assigns the concentrated pixel assigned to a geometric position on a display described by at least one of a plurality of parameters and gray value, forms the concentrated pixels to a condensed image, resolves a light spread function of a first LED in substantially the same resolution as the condensed image, calculates a backlight needed based on the condensed image, and optimizes a value of a plurality of LEDs by considering the contribution of the plurality of LEDs on the concentrated pixel, wherein light spread functions of the LEDs are used. ### Claim 21 (depends on 20) The lighting a liquid crystal display of claim 20, wherein the processor further designates a start value for the plurality of LEDs without consideration of contribution of other LEDs in the plurality of LEDs and uses a decrease approach to determine final LED values of the plurality of LEDs by considering the contribution of a number of LEDs on the backlight behind concentrated pixels.