Patent US2174234A successfully refreshed from Google Patents.
Patent EP0450203A2 successfully refreshed from Google Patents.
EP0450203A2
Expired / Lapsed
EP
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Touch panel display
Assignee: International Business Machines Corp
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Filing: 1990-03-20
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Granted: —
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Expires: 2010-03-20
Abstract
Abstract A system which can control a plurality of opto-matrix input devices. Each opto-matrix device uses multiplexed scanning of emitter/detector pairs under control of a separate computer. The output of the opto-matrix input device is analog data which is provided to the computer for conversion to digital by the computer. The computer then determines if a stylus is located in the opto-matrix field, and if so, determines the stylus location by analysis of the received data.
Inventors
- 👤 John Howard Barker
- 👤 Ernesto Lefranc
- 👤 Donald Dorsey Williams
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-30 17:03
CPC Classifications
G; G06; G06F; G06F3/00; G06F3/01; G06F3/03; G06F3/041; G06F3/042; G06F3/0421
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
244 words
An opto-matrix input device for detecting and communicating to a computer the position of an opaque point within a predetermined field, said apparatus comprising: a frame, said frame having a first vertical side, a second vertical side, a first horizontal side, and a second horizontal side; a plurality of emitters, said emitters attached to said first horizontal side and said first vertical side such that energy beams from said emitters form a matrix; a plurality of detectors, each corresponding to one of said plurality of emitters, said detectors attached to said second horizontal side and said second vertical side such that energy beams from said corresponding emitters are detected; a first multiplexor, said first multiplexor having means to receive emitter selection control signals input to said first multiplexor by said computer, said first multiplexor electrically interconnected to said emitters for selective activation of energy emission from said emitters under control of said emitter selection control signals; a second multiplexor, said second multiplexor having means to receive detector selection control signals input to said second multiplexor by said computer, said second multiplexor electrically interconnected to said detectors for selective activation of energy detection under control of said detector selection control signals; said second multiplexor further having means to output analog signals produced by said selected detectors to said computer; said computer determining the location of said opaque point by detecting the absence of energy at said selected detector when said energy emission is selectively controlled.
Claim 2
Dependent Claim
76 words
An opto-matrix input device, as recited in claim 1, wherein: said first multiplexor is further comprised of a group emitter multiplexor to select a group of emitters and an individual emitter multiplexor to select an individual emitter from said selected group of emitters; said second multiplexor is further comprised of a group detector multiplexor to select a group of detectors and an individual detector multiplexor to select an individual detector from said selected group of detectors.
Claim 3
Dependent Claim
49 words
An opto-matrix input device, as recited in claim 1, further comprising: an amplifier connected to the output of said selected detector to amplify said analog signal prior to outputting said analog signal to said computer, said amplifier having a high impedance input with a low impedance, low noise output.
Claim 4
Independent Claim
248 words
A system for detecting the position of an opaque point in an opto-matrix input device, said system comprising: a computer; at least one opto-matrix input device, said opto-matrix input device further comprising; a frame, said frame having a first vertical side, a second vertical side, a first horizontal side, and a second horizontal side; a plurality of emitters, said emitters attached to said first horizontal side and said first vertical side such that energy beams from said emitters form a matrix; a plurality of detectors corresponding to said plurality of emitters, said detectors attached to said second horizontal side and said second vertical side such that energy beams from said corresponding emitters are detected; a first multiplexor, said first multiplexor having means to receive emitter selection control signals input to said first multiplexor by said computer, said first multiplexor electrically interconnected to said emitters for selective activation of energy emission from said emitters under control of said emitter selection control signals; a second multiplexor, said second multiplexor having means to receive detector selection control signals input to said second multiplexor by said computer, said second multiplexor electrically interconnected to said detectors for selective activation on energy detection under control of said detector selection control signals; said multiplexor further having means to output analog signals produced by said selected detectors to said computer; said computer determining the location of said opaque point by detecting the absence of energy at said selected detector when said energy emission is selectively controlled.
Claim 5
Dependent Claim
20 words
A system, as recited in claim 4, wherein a plurality of said opto-matrix input devices are connected to said computer.
Claim 6
Dependent Claim
74 words
A system, as recited in claim 4, wherein: said first multiplexor is further comprised of a group emitter multiplexor to select a group of emitters and an individual emitter multiplexor to select an individual emitter from said selected group of emitters; said second multiplexor is further comprised of a group detector multiplexor to select a group of detectors and an individual detector multiplexor to select an individual detector from said selected group of detectors.
Claim 7
Dependent Claim
47 words
A system, as recited in claim 4, further comprising: an amplifier connected to the output of said selected detector to amplify said analog signal prior to outputting said analog signal to said computer, said amplifier having a high impedance input with a low impedance, low noise output.
Claim 8
Independent Claim
81 words
A system, as recited in claims 4 or 7, further comprising: storage means for storing an ambient reference value, said ambient reference value generated by activating said selected detector and deactivating its corresponding emitter comparison means, for comparing said ambient reference value with a measured signal generated by activating said selected detector and activating its corresponding emitter whereby said computer can detect the presence of said opaque point by calculating the difference between said ambient reference value and said measured signal.
Claim 9
Independent Claim
159 words
A method of detecting the position of an opaque point in a predetermined field of at least one opto-matrix input device under control of a separate computer, including the steps of: emitting energy from a first horizontal side and a first vertical side with a plurality of emitters such that energy beams from said emitters form a matrix; detecting energy in said matrix with a plurality of detectors corresponding to said plurality of emitters, said detectors attached to said second horizontal side and said second vertical side such that energy beams from said corresponding emitters are detected; multiplexing said emitters under control of selection control signals input to said multiplexor by said computer; multiplexing said detectors under control of selection control signals input to said multiplexor by said computer; outputting signals produced by said detectors to said computer; computing the location of said opaque point by detecting the absence of energy at selected detectors when said detectors are selected.
Claim 10
Dependent Claim
45 words
A method, as recited in claim 9, further including the steps of: multiplexing said emitters first with a group emitter multiplexor to select a group of emitters and then with an individual emitter multiplexor to select an individual emitter from said selected group of emitters.
Claim 11
Dependent Claim
39 words
A method, as recited in claim 9, further including the steps of: amplifying signals output from said selected detector under control of said computer with an amplifier having a high impedance input with a low impedance, low noise output.
Claim 12
Dependent Claim
30 words
A method, as recited in claim 11, further including the steps of: converting signals output by said amplifier to digital values with a computer having an analog to digital converter.
Claim 13
Dependent Claim
31 words
A method, as recited in claim 9, further including the steps of: converting signals output by said selected detector to digital values with a computer having an analog to digital converter.
Claim 14
Independent Claim
70 words
A method, as recited in claims 12 or 13, further including the steps of: storing an ambient reference value generated by activating said selected detector and deactivating its corresponding emitter; comparing said ambient reference value with a measured signal generated by activating said selected detector and activating its corresponding emitter; detecting the presence of said opaque point by calculating the difference between said ambient reference value and said measured signal.
References Cited (Backward Citations)
No citation records indexed.
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