Touch-sensitive overlay
First Claim
1. A touch-sensitive overlay for placement on a visual display including a system for illuminating areas at a plurality of locations in said display and responsive to an electrical signal to provide an indication of an illuminated area location in said display, comprising:
- a substantially transparent sheet having a plurality of discrete photoreactive transducer means distributed thereon and placeable over said illuminated area location, the photoreactive transducer means having at least one photoelectric characteristic which varies as a function of incident light from said illuminated area location in said display impinging said transducer means, and circuit means for obtaining from said transducer means said electrical signal in response to a variation of said photoelectric characteristic due to incident light from said illuminated area in said display at said transducer means coincident with an external touch of said overlay to identify the location of said touch relative to said display.
3 Assignments
0 Petitions
Accused Products
Abstract
A touch-sensitive overlay (20) for cooperative, optically proximate engagement with a visual display (22) of luminous character information (38) latently occupying one or more of a plurality of character locations (26) defined with a position-multiplexed coordinate array one from another, is comprised of a mask (44) of a photoreactive transducer (52) having at least one photoelectric parameter which varies as a function of incident light from the display of character information striking the transducer, and a signal circuit element (92) responsive to a variation in the photoelectric parameter in communication with the mask for developing a characteristic logic pulse indicative of the position of one or more character locations within the array upon a touch thereof and the coincident presence of character information thereat (48). In a highly preferred implementation, the visual display is a CRT display where the raster scan (24) and associated driving circuitry (96) provides the position-multiplexing of character locations and selective illumination thereof, while the photoreactive transducer is an open photovoltaic cell for developing a localized electric potential at luminous character locations, completed upon a manual touch by the operator at a selected location to develop an output voltage pulse indicative of the position(s) touched, which pulse is then employed to interrogate registers (98) associated with the raster scan circuitry in order to provide spatial determination of the location(s) corresponding to the coincident presence of a touch and luminous character information thereat.
55 Citations
34 Claims
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1. A touch-sensitive overlay for placement on a visual display including a system for illuminating areas at a plurality of locations in said display and responsive to an electrical signal to provide an indication of an illuminated area location in said display, comprising:
- a substantially transparent sheet having a plurality of discrete photoreactive transducer means distributed thereon and placeable over said illuminated area location, the photoreactive transducer means having at least one photoelectric characteristic which varies as a function of incident light from said illuminated area location in said display impinging said transducer means, and circuit means for obtaining from said transducer means said electrical signal in response to a variation of said photoelectric characteristic due to incident light from said illuminated area in said display at said transducer means coincident with an external touch of said overlay to identify the location of said touch relative to said display.
- 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)
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26. A touch sensitive overlay for placement over a visible light emitting display, comprising:
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a transducer including a photoreactive member responsive to incident light from a raster source in said display to generate an electrical signal at a location on said transducer subject to said incident light, said transducer further including an ungrounded conductive member in conductive engagement with said photoreactive member for disposition between said display and said photoreactive member; timing circuit means connected to a ground for controlling said raster source to scan the light emitting display and for determining the instantaneous location of light on the transducer produced by the display; and signal means conductively connected to said ungrounded conductive member and said circuit means for establishing a signal path between said photoreactive member and said ground;
said signal means responsive to capacitive coupling to ground by an external touch at said location on said transducer subject to said incident light to complete an electrical connection to ground;said timing circuit means including means for determining a location of said light emission in said display coincident with said touch. - View Dependent Claims (27, 28, 29, 30, 31)
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32. A touch sensitive overlay for placement over a visible light emitting display, comprising:
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a transducer including a photoreactive member responsive to incident light from a raster source in said display to generate an electrical signal at a location on said transducer subject to said incident light, said transducer further including a grounded conductive member in conductive engagement with said photoreactive member for disposition between said display and said photoreactive member; timing circuit means connected to ground and responsive to the raster for determining the instantaneous location of the light incident on the photoreactive member; a flexible, ungrounded conductive member spaced from said photoreactive member of said transducer and disposed outwardly of said transducer whereby said transducer is disposed between said visible light emitting display and said ungrounded conductive member, said ungrounded conductive member responsive to an external touch at a location thereon to flex into conductive engagement with said photoreactive member; and signal means conductively connected to said conductive member and said timing circuit means, said signal means responsive to conductive engagement of said ungrounded conductive member and a location on said transducer coincident with said incident light on said transducer to complete an electrical connection and provide said electrical signal between said photoreactive member and said timing circuit means; said timing circuit means including means for determining a location of said light emission in said display coincident with said touch. - View Dependent Claims (33, 34)
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Specification