Light-based touch screen with shift-aligned emitter and receiver lenses
First Claim
1. A touch screen comprising:
- a housing;
a display mounted in said housing;
a plurality of emitter lenses mounted in said housing along a common edge of said display;
a plurality of light pulse emitters mounted in said housing, each emitter emitting wide light pulses through a respective one of said emitter lenses over said display;
a plurality of receiver lenses mounted in said housing and arranged so as to be shift-aligned relative to said emitter lenses, such that wide light pulses transmitted through neighboring emitter lenses enter a common receiver lens, and wide light pulses transmitted through an emitter lens enter neighboring receiver lenses;
a plurality of light pulse receivers mounted in said housing, each receiver receiving portions of the transmitted wide light pulses through a respective one of said receiver lenses, and outputting received light intensities in accordance with the portions of the wide light pulses that they receive, each receiver R having an expected output, denoted EXPECTED OUTPUT(E, R), when emitter E is activated and no object blocks its wide light pulse, and an actual output, denoted ACTUAL OUTPUT(E, R); and
a calculating unit, mounted in said housing and connected to said receivers, that calculates a coordinate, along a first dimension, of a location of an object touching said display, by identifying sub-areas of the display in which the object is at least partially located, each sub-area, denoted Area(E, R), corresponding to the section of light emitted by an emitter E that arrives at a receiver R, assigning a respective coordinate to each thus-identified sub-area Area(E, R), and calculating a weighted average of the thus-assigned coordinates, wherein each coordinate'"'"'s weight in the average is determined from a known distribution of intensities of the light emitted by emitter E, based on the differenceEXPECTED OUTPUT(E, R)−
ACTUAL OUTPUT(E, R).
1 Assignment
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Accused Products
Abstract
A touch screen including a housing, a display mounted in the housing, a plurality of collimating lenses mounted in the housing along two opposite edges of the display and arranged along the two edges so as to be shift-aligned relative to one another, a plurality of light pulse emitters mounted in the housing that are spaced apart from and transmit light pulses through the collimating lenses of one of the two edges over the display, a plurality of light pulse receivers mounted in the housing that are spaced apart from and receive the light pulses through the collimating lenses of the opposite of the two edges, and a calculating unit, mounted in the housing and connected to the receivers, that determines a location of a pointer on the display that partially blocks the light pulses transmitted by the emitters, based on outputs of the receivers.
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Citations
26 Claims
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1. A touch screen comprising:
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a housing; a display mounted in said housing; a plurality of emitter lenses mounted in said housing along a common edge of said display; a plurality of light pulse emitters mounted in said housing, each emitter emitting wide light pulses through a respective one of said emitter lenses over said display; a plurality of receiver lenses mounted in said housing and arranged so as to be shift-aligned relative to said emitter lenses, such that wide light pulses transmitted through neighboring emitter lenses enter a common receiver lens, and wide light pulses transmitted through an emitter lens enter neighboring receiver lenses; a plurality of light pulse receivers mounted in said housing, each receiver receiving portions of the transmitted wide light pulses through a respective one of said receiver lenses, and outputting received light intensities in accordance with the portions of the wide light pulses that they receive, each receiver R having an expected output, denoted EXPECTED OUTPUT(E, R), when emitter E is activated and no object blocks its wide light pulse, and an actual output, denoted ACTUAL OUTPUT(E, R); and a calculating unit, mounted in said housing and connected to said receivers, that calculates a coordinate, along a first dimension, of a location of an object touching said display, by identifying sub-areas of the display in which the object is at least partially located, each sub-area, denoted Area(E, R), corresponding to the section of light emitted by an emitter E that arrives at a receiver R, assigning a respective coordinate to each thus-identified sub-area Area(E, R), and calculating a weighted average of the thus-assigned coordinates, wherein each coordinate'"'"'s weight in the average is determined from a known distribution of intensities of the light emitted by emitter E, based on the difference EXPECTED OUTPUT(E, R)−
ACTUAL OUTPUT(E, R). - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26)
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Specification