Stereo Optical Sensors for Resolving Multi-Touch in a Touch Detection System
First Claim
1. A touch detection system for resolving multitouch scenarios, the system comprising:
- a touch area;
one or more optical emitters for emitting energy across the touch area;
a first pair of optical sensors positioned along at least one edge of the touch area;
a second pair of optical sensors positioned along at least one edge of the touch area; and
a computing system interfaced with the first and second pairs of optical sensors, the computer system configured to;
receive data signals indicating a first plurality of shadows detected by the first pair of optical sensors and a second plurality of shadows detected by the second pair of optical sensors, the first and second plurality of shadows caused by multiple true touch points,triangulating the first plurality of shadows to determine a first set of potential points and triangulating the second plurality of shadows to determine a second set of potential points,determining potential point pairs comprising combinations of the first set of potential points and the second set of potential points,for each potential point pair, calculating the distance between its constituent potential points, anddetermining that a plurality of the potential point pairs having the shortest distances between their constituent potential points are the true touch points.
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Accused Products
Abstract
An optical touch detection system including at least two stereo pairs of optical sensors, which are identify a set of potential points, and methods for determining which of the potential points are true touch points. The first pair of optical sensors is used to identify a first set of potential points and the second set of optical sensors is used to identify a second set of potential points. Potential point pairs are then compared as between the first and second sets of potential points, i.e., each potential point pair includes a potential point from the first set and a potential point from the second set. Each potential point pair is evaluated to determine the distance between its constituent potential points. The true touch points are identified by selecting the potential point pairs having the shortest distances between their constituent potential points. Using at least two pairs of optical sensors reduces the total number of potential point pairs that must be evaluated to determine the true touch points necessary computational analysis.
145 Citations
24 Claims
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1. A touch detection system for resolving multitouch scenarios, the system comprising:
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a touch area; one or more optical emitters for emitting energy across the touch area; a first pair of optical sensors positioned along at least one edge of the touch area; a second pair of optical sensors positioned along at least one edge of the touch area; and a computing system interfaced with the first and second pairs of optical sensors, the computer system configured to; receive data signals indicating a first plurality of shadows detected by the first pair of optical sensors and a second plurality of shadows detected by the second pair of optical sensors, the first and second plurality of shadows caused by multiple true touch points, triangulating the first plurality of shadows to determine a first set of potential points and triangulating the second plurality of shadows to determine a second set of potential points, determining potential point pairs comprising combinations of the first set of potential points and the second set of potential points, for each potential point pair, calculating the distance between its constituent potential points, and determining that a plurality of the potential point pairs having the shortest distances between their constituent potential points are the true touch points. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A method for resolving multitouch scenarios, the method comprising:
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emitting energy across a touch area; detecting a first plurality of shadows with a first pair of optical sensors that are positioned along at least one edge of the touch area; detecting a second plurality of shadows with a second pair of optical sensors that are positioned along at least one edge of the touch area, wherein the first and second plurality of shadows are caused by multiple true touch points; triangulating the first plurality of shadows to determine a first set of potential points and triangulating the second plurality of shadows to determine a second set of potential points; determining potential point pairs comprising combinations of the first set of potential points and the second set of potential points; calculating the distance between the constituent potential points for each potential point pair; and determining that a plurality of the potential point pairs having the shortest distances between their constituent potential points are the true touch points. - View Dependent Claims (15, 16, 17)
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18. A computer-readable medium tangibly embodying program code operable for causing a processor to identify a true touch point from a plurality of potential points, the computer-readable medium comprising:
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program code for receiving data signals indicating a first plurality of shadows detected by a first pair of optical sensors, wherein the first pair of optical sensors are positioned along at least one edge of a touch area; program code for receiving data signals indicating a second plurality of shadows detected by a second pair of optical sensors, wherein the second pair of optical sensors are positioned along at least one edge of the touch area and the first and second plurality of shadows are caused by multiple true touch points; program code for triangulating the first plurality of shadows to determine a first set of potential points and triangulating the second plurality of shadows to determine a second set of potential points; program code for determining potential point pairs comprising combinations of the first set of potential points and the second set of potential points; program code for calculating the distance between constituent potential points for each potential point pair; and program code for determining that a plurality of the potential point pairs having the shortest distances between their constituent potential points are the true touch points.
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19. A touch detection system for resolving multitouch scenarios, the system comprising:
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a touch area; a first pair of optical sensors positioned along at least one edge of the touch area; a second pair of optical sensors positioned along at least one edge of the touch area; and a computing system interfaced with the first and second pairs of optical sensors, the computer system configured to; generating a first plurality of images of the touch area based on data signals received from the first pair of area optical sensors and generating a second plurality of images of the touch area based on data signals received from the second pair of optical sensors, for each of the first plurality of images and the second plurality of images, determining relative positions of touch objects used to effect multiple true touch points, triangulating the relative positions of the touch objects of the first plurality of images to determine a first set of potential points and triangulating the relative positions of the touch objects of the second plurality of images to determine a second set of potential points, determining potential point pairs comprising combinations of the first set of potential points and the second set of potential points, for each potential point pair, calculating the distance between its constituent potential points, and determining that a plurality of the potential point pairs having the shortest distances between their constituent potential points are the true touch points. - View Dependent Claims (20, 21, 22, 23, 24)
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Specification