# US 2013/0278563 A1 · Optical touch device and touch sensing method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2013/0278563 A1 - Document ID: US20130278563A1 - Status: Published application - Kind: A1 - Application number: 13/607,818 - Filed: 2012-09-10 - Published: 2013-10-24 - Earliest claimed: 2012-04-19 - Assignees: Wistron Corporation - Inventors: Hsun-Hao Chang; Yu-Yen Chen; Sheng-Hsien Hsieh; Shou-Te Wei - Web page: https://patentgrep.com/patent/US20130278563A1 ## 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)} - G06F 3/0416: {Control or interface arrangements specially adapted for digitisers} - G06F 2203/04104: Multi-touch detection in digitiser, i.e. details about the simultaneous detection of a plurality of touching locations, e.g. multiple fingers or pen and finger - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) ## Abstract An optical touch device includes an indication plane, two image sensing units and a processing unit. The two image sensing units are disposed at two corners of the indication plane diagonal to each other, respectively, and the two corners define a diagonal line connected therebetween. The processing unit is electrically connected to the two image sensing units. When two touch points are performed on the indication plane, the processing unit determines whether the two touch points are located at opposite sides of the diagonal line, respectively, according to images sensed by the two image sensing units. Once the two touch points are located at opposite sides of the diagonal line, respectively, the processing unit calculates and outputs coordinates of the two touch points immediately according to the images sensed by the two image sensing units. ## Claims ### Claim 1 An optical touch device comprising: an indication plane; two image sensing units disposed at two corners of the indication plane diagonal to each other, respectively, the two corners defining a diagonal line connected therebetween; and a processing unit electrically connected to the two image sensing units; wherein when two touch points are performed on the indication plane, the processing unit determines whether the two touch points are located at opposite sides of the diagonal line, respectively, according to images sensed by the two image sensing units; once the two touch points are located at opposite sides of the diagonal line, respectively, the processing unit calculates and outputs coordinates of the two touch points immediately according to the images sensed by the two image sensing units. ### Claim 2 (depends on 1) The optical touch device of claim 1, wherein once the two touch points both are located at one side of the diagonal line and are not performed on the indication plane simultaneously, the processing unit identifies the two touch points as real touch points and then calculates and outputs coordinates of the two touch points according to appearance sequence of the two touch points sensed by the two image sensing units. ### Claim 3 (depends on 1) The optical touch device of claim 1, wherein once the two touch points both are located at one side of the diagonal line and are performed on the indication plane simultaneously, the processing unit identifies the two touch points as real touch points and then calculates and outputs coordinates of the two touch points according to brightness of the two touch points sensed by the two image sensing units. ### Claim 4 (depends on 1) The optical touch device of claim 1, wherein once the two touch points both are located at one side of the diagonal line and are moving on the indication plane, the processing unit identifies the two touch points as real touch points and then calculates and outputs coordinates of the two touch points according to moving trajectories of the two touch points. ### Claim 5 A touch sensing method adapted to an optical touch device, the optical touch device comprising an indication plane and two image sensing units disposed at two corners of the indication plane diagonal to each other, respectively, the two corners defining a diagonal line connected therebetween, the touch sensing method comprising: when two touch points are performed on the indication plane, determining whether the two touch points are located at opposite sides of the diagonal line, respectively, according to images sensed by the two image sensing units; and once the two touch points are located at opposite sides of the diagonal line, respectively, calculating and outputting coordinates of the two touch points immediately according to the images sensed by the two image sensing units. ### Claim 6 (depends on 5) The touch sensing method of claim 5, further comprising: once the two touch points both are located at one side of the diagonal line and are not performed on the indication plane simultaneously, identifying the two touch points as real touch points and then calculating and outputting coordinates of the two touch points according to appearance sequence of the two touch points sensed by the two image sensing units. ### Claim 7 (depends on 5) The touch sensing method of claim 5, further comprising: once the two touch points both are located at one side of the diagonal line and are performed on the indication plane simultaneously, identifying the two touch points as real touch points and then calculating and outputting coordinates of the two touch points according to brightness of the two touch points sensed by the two image sensing units. ### Claim 8 (depends on 5) The touch sensing method of claim 5, further comprising: once the two touch points both are located at one side of the diagonal line and are moving on the indication plane, identifying the two touch points as real touch points and then calculating and outputting coordinates of the two touch points according to moving trajectories of the two touch points.