# US 8,786,643 B2 · Edge-lit local dimming displays, display components and related methods > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,786,643 B2 - Document ID: US8786643B2 - Status: Granted - Kind: B2 - Application number: 13/378,759 - Filed: 2010-07-06 - Published: 2012-04-19 - Granted: 2014-07-22 - Earliest claimed: 2009-07-07 - Assignees: Dolby Laboratories Licensing Corporation - Applicants: Helge Seetzen - Inventors: Helge Seetzen - Web page: https://patentgrep.com/patent/US8786643B2 ## CPC - G09G 3/3426: {the different display panel areas being distributed in two dimensions, e.g. matrix} - G02B 6/0033: {Means for improving the coupling-out of light from the light guide} - G02F 1/133615: {Edge-illuminating devices, i.e. illuminating from the side} - G02F 1/167: by electrophoresis - G02F 1/1677: Structural association of cells with optical devices, e.g. reflectors or illuminating devices - G02B 6/3536: {involving evanescent coupling variation, e.g. by a moving element such as a membrane which changes the effective refractive index (mode converters G02B6/14; adjustable lateral coupling between waveguides G02B6/283; electro- optical refractive index variations G02F1/0118)} - G02B 6/357: {Electrostatic force (electrostatic forces controlling reflecting elements in general G02B26/0841)} - G02F 1/133545: {Dielectric stack polarisers} - G02F 1/133601: {for spatial active dimming} - G02F 2201/44: Arrangements combining different electro-active layers, e.g. electrochromic, liquid crystal or electroluminescent layers - G02F 2202/04: dye - G09G 3/3433: {using light modulating elements actuated by an electric field and being other than liquid crystal devices and electrochromic devices (using liquid crystal devices G09G3/36; using electrochromic devices G09G3/38)} - G09G 3/344: {based on particles moving in a fluid or in a gas, e.g. electrophoretic devices (electrophoretic devices per se G02F1/167)} - G09G 3/3611: {Control of matrices with row and column drivers} - G09G 2300/023: Display panel composed of stacked panels - G09G 2320/0646: Modulation of illumination source brightness and image signal correlated to each other - 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) - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS - G02F: OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS ## Abstract An edge-lit display having a front modulator in the top layer of an optical package and an extractor in at least one of the top and bottom layers. A control system is connected to control the extraction mechanism to project light which approximates a desired image onto the front modulator, estimate a pattern of light incident on the front modulator, and control the front modulator based on the estimated pattern. ## Claims ### Claim 1 A display comprising: an optical package having a top layer on a side, and a bottom layer on an opposite side, the top layer comprising a front modulator having a plurality of individually-controllable elements, each of the individually-controllable elements having a variable transmissivity; a plurality of light sources positioned along at least one edge of the optical package, the light sources configured to direct light into the optical package; an extractor in at least one of the top layer and the bottom layer, the extractor having a plurality of individually-controllable segments configured to direct varying levels of light toward the front modulator; and, a control system connected to control the front modulator and the extractor, the control system configured to receive image data specifying a desired image, control the extractor to project a low spatial resolution pattern of light which is defined by said received image data and approximates the desired image onto the front modulator, estimate a pattern of light incident on the front modulator, and control the front modulator based on the estimated pattern, wherein said extractor and said front modulator comprise a locally dimmable modulator, where said extractor substantially forms said low spatial resolution pattern and said front modulator substantially forms a high spatial resolution pattern of said desired image, wherein the control system is configured to control the light sources based on the image data, wherein the control system comprises a brightness controller configured to measure an accumulated luminance for each of a plurality of regions of the image data and provide separate driving levels to a plurality of groups of light sources, each group corresponding to a region of the image data. ### Claim 2 (depends on 1) A display according to claim 1 wherein the accumulated luminance is measured over all pixels of a region. ### Claim 3 (depends on 1) A display according to claim 1 wherein the driving level for each light group is determined based on the accumulated luminance of the region corresponding to the light group. ### Claim 4 (depends on 1) A display according to claim 1 wherein each region comprises a strip running in a direction parallel to a direction of light from the associated group of light sources. ### Claim 5 (depends on 4) A display according to claim 4 wherein the strips physically divide the optical package by reflective walls that are built into the optical package. ### Claim 6 (depends on 1) A display according to claim 1 wherein the optical package comprises a waveguide and the extractor comprises an electrophoretic layer adjacent to a top surface of the waveguide. ### Claim 7 (depends on 1) A display according to claim 1 wherein the optical package comprises a waveguide and the extractor comprises an electrophoretic layer adjacent to a bottom surface of the waveguide. ### Claim 8 (depends on 1) A display according to claim 1 wherein the optical package comprises a waveguide having structured top and bottom surfaces configured to produce a desired extraction profile. ### Claim 9 A display comprising: an optical package having a top layer on a side, and a bottom layer on an opposite side, the top layer comprising a front modulator having a plurality of individually-controllable elements, each of the individually-controllable elements having a variable transmissivity; a plurality of light sources positioned along at least one edge of the optical package, the light sources configured to direct light into the optical package; an extractor in at least one of the top layer and the bottom layer, the extractor having a plurality of individually-controllable segments configured to direct varying levels of light toward the front modulator; and, a control system connected to control the front modulator and the extractor, the control system configured to receive image data specifying a desired image, control the extractor to project a low spatial resolution pattern of light which is defined by said received image data and approximates the desired image onto the front modulator, estimate a pattern of light incident on the front modulator, and control the front modulator based on the estimated pattern, wherein said extractor and said front modulator comprise a locally dimmable modulator, where said extractor substantially forms said low spatial resolution pattern and said front modulator substantially forms a high spatial resolution pattern of said desired image, wherein the control system is configured to control the light sources based on the image data, wherein the control system comprises a brightness controller configured to measure an accumulated luminance or average luminance or weighted average luminance or maximum luminance of pixels of the image data and provide driving levels to the light sources based on the measured luminance, wherein the brightness controller is connected to provide a brightness control signal to an extraction controller and a pattern estimator, wherein the extraction controller is configured to control the extractor based on the image data and the brightness control signal, and connected to provide an extraction control signal to the pattern estimator, wherein the pattern estimator is configured to estimate the pattern of light incident on the front modulator based on the image data, the brightness control signal and the extraction control signal, wherein at least one of the extraction controller and the pattern estimator is configured to calculate the estimated pattern based on intensities and point spread functions of the light extracted from the optical package. ### Claim 10 (depends on 9) A display according to claim 9 wherein the estimated pattern is based at least on a model of the optical characteristics of the optical package stored in a memory accessible by the pattern estimator. ### Claim 11 (depends on 9) A display according to claim 9 wherein the pattern estimator is connected to provide the estimated pattern to a transmission controller configured to control the transmissivities of the individually-controllable elements of the front modulator. ### Claim 12 (depends on 1) A display according to claim 1 wherein the optical package comprises an open cavity between the top layer and the bottom layer, and the extractor comprises a modulatable reflective layer in the bottom layer of the optical package. ### Claim 13 (depends on 12) A display according to claim 12 wherein the modulatable reflective layer comprises a reflective-type LCD. ### Claim 14 (depends on 12) A display according to claim 12 wherein the modulatable reflective layer comprises an electrowetting display. ### Claim 15 (depends on 12) A display according to claim 12 wherein the modulatable reflective layer comprises an electrophoretic display. ### Claim 16 (depends on 12) A display according to claim 12 wherein the modulatable reflective layer comprises electronic paper. ### Claim 17 (depends on 12) A display according to claim 12 wherein the modulatable reflective layer is configured to provide a contrast ratio of at least 5:1. ### Claim 18 (depends on 12) A display according to claim 12 wherein the modulatable reflective layer is configured to produce a pattern of light which is smoothly varying between adjacent individually-controllable segments. ### Claim 19 A method of displaying an image, the method comprising: providing a display comprising: an optical package having a top layer on a side, and a bottom layer on an opposite side, the top layer comprising a front modulator having a plurality of individually-controllable elements, each of the individually-controllable elements having a variable transmissivity; a plurality of light sources positioned along at least one edge of the optical package, the light sources configured to direct light into the optical package; and, an extractor in at least one of the top layer and the bottom layer, the extractor having a plurality of individually-controllable segments configured to project a low spatial resolution pattern of light which is defined by said received image data and approximates the desired image onto the front modulator, estimate a pattern of light incident on the front modulator, and control the front modulator based on the estimated pattern, wherein said extractor and said front modulator comprise a locally dimmable modulator, where said extractor substantially forms said low spatial resolution pattern and said front modulator substantially forms a high spatial resolution pattern of said desired image; receiving image data specifying a desired image; controlling the extractor to project light which approximates the desired image onto the front modulator; estimating a pattern of light incident on the front modulator; controlling the front modulator based on the estimated pattern; controlling the light sources based on the image data; measuring an accumulated luminance for each of a plurality of regions of the image data; and, providing separate driving levels to a plurality of groups of light sources, each group associated with a region of the image data. ### Claim 20 (depends on 19) A method according to claim 19 wherein the accumulated luminance is measured over all pixels of a region. ### Claim 21 (depends on 19) A method according to claim 19 wherein the driving level for each light group is based on the accumulated luminance of the region corresponding to the light group.