# US 8,541,856 B2 · Optical touch-screen imager > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,541,856 B2 - Document ID: US8541856B2 - Status: Granted - Kind: B2 - Application number: 12/963,446 - Filed: 2010-12-08 - Published: 2012-06-14 - Granted: 2013-09-24 - Earliest claimed: 2010-12-08 - Assignees: OmniVision Technologies, Inc. - Applicants: Dominic Massetti - Inventors: Dominic Massetti - Web page: https://patentgrep.com/patent/US8541856B2 ## CPC - G06F 3/0428: {by sensing at the edges of the touch surface the interruption of optical paths, e.g. an illumination plane, parallel to the touch surface which may be virtual (sensing beam interruptions in a planar beam grid of an optical touch-screen G06F3/0421)} - H10F 39/011: {Manufacture or treatment of image sensors covered by group H10F39/12} - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) - H10F: INORGANIC SEMICONDUCTOR DEVICES SENSITIVE TO INFRARED RADIATION, LIGHT, ELECTROMAGNETIC RADIATION OF SHORTER WAVELENGTH OR CORPUSCULAR RADIATION ## Abstract Embodiments of an apparatus comprising a CMOS image sensor including a pixel array formed in a substrate and a light guide formed on the substrate to receive light traveling in a plane parallel to a plane of the pixel array and incident on the edge of the image sensor and to re-direct the incident light into at least one pixel of the pixel array. Embodiments of an optical touch-screen imager comprising a substantially planar touch area and a detector positioned adjacent to the touch area, the detector comprising a CMOS image sensor as described above. ## Claims ### Claim 1 An apparatus comprising: a CMOS image sensor including a pixel array formed in a CMOS image sensor substrate; a light guide formed on the CMOS image sensor substrate to receive light traveling parallel to a plane of the pixel array and incident on the edge of the CMOS image sensor and to re-direct the incident light into at least one pixel of the pixel array. ### Claim 2 (depends on 1) The apparatus of claim 1 wherein the pixel array is formed on a front side of the CMOS image sensor substrate and the light guide is formed on the front side of the CMOS image sensor substrate over the pixel array. ### Claim 3 (depends on 1) The apparatus of claim 1 wherein the pixel array is formed on a front side of the CMOS image sensor substrate and the light guide is formed on a back side of the CMOS image sensor substrate. ### Claim 4 (depends on 1) The apparatus of claim 1 wherein the light guide includes an inclined reflective surface positioned at a selected angle relative to the plane of the pixel array. ### Claim 5 (depends on 4) The apparatus of claim 4 wherein the selected angle is 45 degrees. ### Claim 6 (depends on 4) The apparatus of claim 4 wherein the light guide further comprises: a first reflective surface abutting one edge of the inclined surface; and a second reflective surface spaced apart from the first reflective surface, the second reflective surface abutting another edge of the inclined surface. ### Claim 7 (depends on 6) The apparatus of claim 6 wherein the first reflective surface forms a mask to allow light to reach only selected pixels in the pixel array. ### Claim 8 (depends on 7) The apparatus of claim 7 wherein the selected pixels form one or more lines of pixels on the pixel array. ### Claim 9 (depends on 7) The apparatus of claim 7 wherein the mask includes two or more separate openings. ### Claim 10 (depends on 6) The apparatus of claim 6 wherein the light guide further comprises a transparent material disposed in the volume bounded by the first reflective surface, the second reflective surface, the inclined reflective surface and a radiation entry of the light guide. ### Claim 11 (depends on 1) The apparatus of claim 1, further comprising an anti-reflective coating formed between the pixel array and the light guide to block visible light from reaching selected pixels while allowing infra-red or near infra-red light to reach the selected pixels. ### Claim 12 An optical touch-screen imager comprising: a substantially planar touch area; a detector positioned adjacent to the touch area, the detector comprising: a CMOS image sensor including a pixel array formed in a CMOS image sensor substrate, the image sensor being positioned so that a plane of the pixel array is substantially parallel to the plane of the touch area, and a light guide formed on the CMOS image sensor substrate to receive light traveling parallel to a plane of the pixel array and incident on the edge of the CMOS image sensor and to re-direct the incident light into at least one pixel of the pixel array. ### Claim 13 (depends on 12) The optical touch-screen imager of claim 12 wherein the touch area is a quadrilateral and detector is positioned at a corner of the quadrilateral. ### Claim 14 (depends on 12) The optical touch-screen imager of claim 12, further comprising a radiation source to transmit radiation that travels in a plane substantially parallel to the plane of the imaging area. ### Claim 15 (depends on 12) The optical touch-screen imager of claim 12 wherein the source radiates infra-red or near infra-red radiation. ### Claim 16 (depends on 12) The optical touch-screen imager of claim 12 wherein the pixel array is formed on a front side of the CMOS image sensor substrate and the light guide is formed on the front side of the CMOS image sensor substrate over the pixel array. ### Claim 17 (depends on 12) The optical touch-screen imager of claim 12 wherein the pixel array is formed on a front side of the CMOS image sensor substrate and the light guide is formed on a back side of the CMOS image sensor substrate. ### Claim 18 (depends on 12) The optical touch-screen imager of claim 12 wherein the light guide further comprises: an inclined reflective surface positioned at a selected angle relative to the plane of the pixel array; a first reflective surface abutting one edge of the inclined surface; and a second reflective surface spaced apart from the first reflective surface, the second reflective surface abutting another edge of the inclined surface. ### Claim 19 (depends on 18) The optical touch-screen imager of claim 18 wherein the first reflective surface forms a mask to allow light to reach only selected pixels in the pixel array. ### Claim 20 (depends on 19) The optical touch-screen imager of claim 19 wherein the mask includes two or more separate openings. ### Claim 21 (depends on 18) The optical touch-screen imager of claim 18, further comprising an anti-reflective coating formed between the pixel array and the light guide to block visible light from reaching selected pixels while allowing infra-red or near infra-red light to reach the selected pixels. ### Claim 22 A process comprising: forming a pixel array in a CMOS image sensor substrate; forming a light guide on the CMOS image sensor substrate to receive light traveling parallel to a plane of the pixel array and incident on the edge of the CMOS image sensor, and to re-direct the incident light into at least one pixel of the pixel array. ### Claim 23 (depends on 22) The process of claim 22 wherein the pixel array is formed on a front side of the CMOS image sensor substrate and the light guide is formed on the front side of the CMOS image sensor substrate over the pixel array. ### Claim 24 (depends on 22) The process of claim 22 wherein the pixel array is formed on a front side of the CMOS image sensor substrate and the light guide is formed on a back side of the CMOS image sensor substrate. ### Claim 25 (depends on 22) The process of claim 22 wherein forming the light guide comprises: forming an inclined reflective surface positioned at a selected angle relative to the plane of the pixel array forming a first reflective surface abutting one edge of the inclined surface; and forming a second reflective surface spaced apart from the first reflective surface, the second reflective surface abutting another edge of the inclined surface. ### Claim 26 (depends on 25) The process of claim 25 wherein the first reflective surface forms a mask to allow light to reach only selected pixels in the pixel array. ### Claim 27 (depends on 26) The process of claim 26 wherein the mask includes two or more separate openings. ### Claim 28 (depends on 25) The process of claim 25, further comprising disposing a transparent material in the volume bounded by the first reflective surface, the second reflective surface, the inclined reflective surface and a radiation entry of the light guide. ### Claim 29 (depends on 28) The process of claim 28, further comprising a layer of planarizer or adhesive formed over the first reflective surface, the second reflective surface, and the inclined reflective surface. ### Claim 30 (depends on 29) The process of claim 29, further comprising a cover formed on the planarizer or adhesive. ### Claim 31 (depends on 30) The process of claim 30 wherein the cover is a glass plate or a silicon layer. ### Claim 32 (depends on 30) The process of claim 30 wherein the cover is spaced apart from the plane of the pixel array by a clear spacer. ### Claim 33 (depends on 22) The process of claim 22, further comprising forming an anti-reflective coating between the pixel array and the light guide to block visible light from reaching selected pixels while allowing infra-red or near infra-red light to reach the selected pixels.