Photo-optical keyboards
First Claim
1. A photo-optical keyboard comprising:
- keying means having a plurality of individual keys, each moveable between a released position and a depressed position and having a means for yieldably encouraging each said key to said released position;
a plurality of light sources, said plurality of light sources being less in number than said plurality of individual keys;
a plurality of light sensors, said plurality of light sensors being less in number than said plurality of individual keys, at least some of said light sources being disposed to direct different portions of the light therefrom toward different ones of said light sensors, said last named light sources and light sensors being positioned with respect to specific ones of said keys so that for each key of said last named keys, that said key and only that said key may substantially block light between a specific one of said light sources and a specific one of said light sensors when in one of said released and depressed positions and not substantially block light when in the other of said released and depressed positions, whereby the depression of any of said last named keys may be detected by the turning on of the associated one of said light sources and the detecting of the state of the said light sensors associated therewith.
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Accused Products
Abstract
Photo-optical keyboards for providing electrical signals responsive to the keying of the keyboard. The keyboard structure consists of an arrangement of individual keys disposed and identified in accordance with the particular application and adapted for longitudinal motion on depression thereof. Located below the plurality of keys is a matrix of light sources and photo detectors disposed in such a manner that depression of any single key will interrupt the light path between one of the light sources and one of the detectors to provide a change in the electrical state of the associated circuitry. The light sources and detectors are arranged so that in general a single light source illuminates a plurality of detectors, and each detector may be illuminated by any of a plurality of light sources, so that the number of light sources and sensors required for the complete keyboard is substantially less than the number of keys to be sensed. A microprocessor based system for scanning the light sources and detectors is disclosed. In general individual light channels in the keyboard structure are not required as a scanning technique avoids undesired optical cross-talk. By making a portion of each key substantially transparent, light from the light sources may be directed upward through the keys to illuminate the keyboard.
114 Citations
32 Claims
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1. A photo-optical keyboard comprising:
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keying means having a plurality of individual keys, each moveable between a released position and a depressed position and having a means for yieldably encouraging each said key to said released position; a plurality of light sources, said plurality of light sources being less in number than said plurality of individual keys; a plurality of light sensors, said plurality of light sensors being less in number than said plurality of individual keys, at least some of said light sources being disposed to direct different portions of the light therefrom toward different ones of said light sensors, said last named light sources and light sensors being positioned with respect to specific ones of said keys so that for each key of said last named keys, that said key and only that said key may substantially block light between a specific one of said light sources and a specific one of said light sensors when in one of said released and depressed positions and not substantially block light when in the other of said released and depressed positions, whereby the depression of any of said last named keys may be detected by the turning on of the associated one of said light sources and the detecting of the state of the said light sensors associated therewith. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A photo-optical keyboard comprising;
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keying means having a first plurality of individual keys, each moveable between a released position and a depressed position and having a means for yieldably encouraging each said key to said released position; a plurality of light sources, said plurality of light sources being less in number than said plurality of individual keys; a plurality of light sensors, said plurality of light sensors being less in number than said plurality of individual keys, at least some of said light sensors being disposed to receive light directed thereto by different ones of said light sources, said last named light sources and light sensors being positioned with respect to specific ones of said keys so that for each one key of said last named keys, that said key and only that said key may substantially block light between a specific one of said light sources and a specific one of said light sensors when in one of said released and depressed positions and not substantially block light when in the other of said released and depressed positions, whereby the depression of any key may be detected by the turning on of the associated said light source and the detecting of the state of the said light sensors associated therewith. - View Dependent Claims (14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24)
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25. A keyboard comprising;
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a keyboard panel assembly having a plurality of keys each being yieldably encouraged to an upper released position and being depressible to a lower depressed position, each of said keys having a lower key member extending below the rest of said panel assembly when the respective said key is depressed; support means disposed below said panel assembly; a plurality of light sources, supported by said support means, said plurality of light sources being less in number than said plurality of keys; a plurality of light sensors supported by said support means, said plurality of light sensors being less in number than said plurality of keys, at least some of said light sources being disposed to direct different portions of the light therefrom toward different ones of said light sensors, at least some of said light sensors being disposed to receive light directed thereto by different ones of said light sources, said last named light sources and light sensors being positioned with respect to specific ones of said keys so that, for each key of said last named keys, said lower key member of said key may substantially block light between a specific one of said light sources and a specific one of said light sensors when in said depressed position and not substantially block light when in said released position, whereby the depression of any key may be detected by the turning on of the associated said light source and the detecting of the state of the said light sensors associated therewith. - View Dependent Claims (26, 27, 28, 29, 30, 31)
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32. Apparatus responsive to the position of a moveable element comprising;
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light sensor means for being electrically conductive in response to light incident thereto, said light sensor means being coupled in circuit to encourage an electrical line from a first electrical state to a second electrical state upon receipt of light. light source means for directing light to said light sensor means in a manner to be interrupted to an extent dependent on the position of the moveable element; means for sequentially charging said electrical line to said first state, for sequentially turning on said light source means, and for determining whether said electrical line goes to said second state within a predetermined time as a measure of the position of the moveable member.
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Specification