# US 2009/0153749 A1 · Portable projector background color correction scheme > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2009/0153749 A1 - Document ID: US20090153749A1 - Status: Published application - Kind: A1 - Application number: 12/002,206 - Filed: 2007-12-14 - Published: 2009-06-18 - Earliest claimed: 2007-12-14 - Inventors: Stephen Randall Mixon - Web page: https://patentgrep.com/patent/US20090153749A1 ## CPC - H04N 9/3161: {using laser light sources (using laser beams scanning the display screen H04N9/3129)} - H04N 9/3129: {scanning a light beam on the display screen (scanning a light beam on a screen in displays other than projection devices G09G3/02; scanning systems in general G02B26/10; projectors using laser light sources in general H04N9/3161)} - H04N 9/3173: {wherein the projection device is specially adapted for enhanced portability} - H04N 9/3182: {Colour adjustment, e.g. white balance, shading or gamut (white balance per se H04N9/73; control of amplitude of colour signals H04N9/68; colour control circuits for displays in general G09G5/02, G09G3/2003, G09G3/3607)} - H04N 9/3194: {including sensor feedback} - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract According to one embodiment of the present invention, a method of controlling an image projector comprising a multi-color laser source, projection optics, an image sensor, and a movement detection device comprises the projection of an image onto a display surface with the image projector. During projection, a movement signal generated by movement detection device is monitored, the movement signal indicating positional displacement of the image projector. A test pattern image is projected onto the display surface using the image projector, wherein the test pattern image projection is initiated as a function of the monitored movement signal. Thereafter, the projected test pattern image is captured from the display surface using the image sensor. A comparison of projected test pattern image data and captured test pattern image data is used to modify the manner in which subsequent images are projected to correct color distortions represented in the captured test pattern image. ## Claims ### Claim 1 A method of controlling an image projector comprising a multi-color laser source, projection optics, an image sensor, and a movement detection device, the method comprising: projecting an image onto a display surface using the multi-color laser source and the projection optics of the image projector; monitoring a movement signal generated by the movement detection device, wherein the movement signal is indicative of positional displacement of the image projector; projecting a test pattern image onto the display surface using the multi-color laser source and the projection optics, wherein the test pattern image projection is initiated as a function of the monitored movement signal; capturing the projected test pattern image from the display surface using the image sensor; and utilizing a comparison of projected test pattern image data and captured test pattern image data to modify the manner in which subsequent images are projected using the multi-color laser source and the projection optics of the image projector to correct color distortions represented in the captured test pattern image. ### Claim 2 (depends on 1) The method of claim 1, wherein: the image is projected onto the display surface by scanning multiple beams of the multi-color laser source across an image frame, and the image is projected by generating a plurality of successive image frames. ### Claim 3 (depends on 1) The method of claim 1, wherein projection data used to project the image and the subsequent images is derived from a combination of image data particular to the image to be projected and correction data derived from the comparison of the projected test pattern image data and the captured test pattern image data. ### Claim 4 (depends on 1) The method of claim 1, wherein the positional displacement indicated by the movement signal comprises a range of values indicating a degree of positional displacement of the image projector. ### Claim 5 (depends on 1) The method of claim 1, wherein the positional displacement indicated by the movement signal comprises either a stationary value indicating a stationary image projector or a displaced value indicating a displaced image projector. ### Claim 6 (depends on 1) The method of claim 1, wherein the test pattern image is projected onto the display surface by scanning one or more beams of the multi-color laser source across a test pattern image frame. ### Claim 7 (depends on 1) The method of claim 1, wherein the test pattern image comprises a compilation of image elements that is substantially uniform in color or defines a varying color distribution. ### Claim 8 (depends on 1) The method of claim 1, wherein: the test pattern image is projected as a compilation of picture elements; and the projected test pattern image is captured as a compilation of picture elements. ### Claim 9 (depends on 8) The method of claim 8, wherein the projected test pattern image data and the captured test pattern image data are compared on an element-by-element basis. ### Claim 10 (depends on 9) The method of claim 9, wherein the manner in which the subsequent images are projected is modified on an element-by-element basis. ### Claim 11 (depends on 8) The method of claim 8, wherein the projected test pattern image data and the captured test pattern image data are compared by referring collectively to multiple adjacent picture elements in the test pattern image. ### Claim 12 (depends on 11) The method of claim 11, wherein the manner in which the subsequent images are projected is modified by modifying multiple adjacent picture elements collectively in the subsequent images. ### Claim 13 (depends on 8) The method of claim 8, wherein the projected test pattern image data and the captured test pattern image data are compared by referring to sub-divided picture elements in the test pattern image. ### Claim 14 (depends on 13) The method of claim 13, wherein the manner in which the subsequent images are projected is modified by modifying sub-divided picture elements in the subsequent images. ### Claim 15 (depends on 8) The method of claim 8, wherein the projected test pattern image data and the captured test pattern image data are compared by referring to an average color intensity value of the test pattern image. ### Claim 16 (depends on 15) The method of claim 15, wherein the manner in which the subsequent images are projected is modified by modifying an average color intensity value in the subsequent images. ### Claim 17 (depends on 1) The method of claim 1, wherein the manner in which the subsequent images are projected is modified by using the comparison of the projected test pattern image data and the captured test pattern image data to generate a table of offset color intensity values. ### Claim 18 (depends on 17) The method of claim 17, wherein the offset color intensity values are added to or subtracted from the color intensity values of corresponding picture elements so as to correct the color distortions represented in the captured test pattern image. ### Claim 19 (depends on 1) The method of claim 1, wherein the manner in which the subsequent images are projected is modified on an element-by-element basis. ### Claim 20 (depends on 1) The method of claim 1, wherein the manner in which the subsequent images are projected is modified by modifying sub-divided picture elements in the subsequent images. ### Claim 21 (depends on 1) The method of claim 1, wherein the manner in which the subsequent images are projected is modified by modifying an average color intensity value defined by a plurality of color intensity values of a plurality of picture elements. ### Claim 22 (depends on 1) The method of claim 1, wherein the manner in which the subsequent images are projected is modified by modifying an average color intensity value defined by substantially all of the color intensity values of substantially all of the picture elements. ### Claim 23 (depends on 1) The method of claim 1, wherein: the multi-color laser source, the projection optics, the image sensor, and the movement detection device of the image projector are mechanically coupled to a common portable platform, and the portable platform resides in a mobile telephone. ### Claim 24 An image projector comprising a multi-color laser source, projection optics, an image sensor, a movement detection device, and a programmable controller collectively configured to: project an image onto a display surface using the multi-color laser source and the projection optics of the image projector; monitor a movement signal generated by the movement detection device, wherein the movement signal is indicative of positional displacement of the image projector; project a test pattern image onto the display surface using the multi-color laser source and the projection optics, wherein the test pattern image projection is initiated as a function of the monitored movement signal; capture the projected test pattern image from the display surface using the image sensor; and utilize a comparison of projected test pattern image data and captured test pattern image data to modify the manner in which subsequent images are projected using the multi-color laser source and the projection optics of the image projector to correct color distortions represented in the captured test pattern image. ### Claim 25 (depends on 24) The image projector of claim 24, wherein: the image projector resides in a portable platform to which the multi-color laser source, the projection optics, the image sensor, and the movement detection device of the image projector are mechanically coupled, and the portable platform resides in a mobile telephone.