Electronic sketch pad
First Claim
1. A display device comprising:
- a transparent array of variable capacitance pixels supported by way of a first member, each variable capacitance pixel undergoing a change in capacitance in response to the coupling of a conductive medium at the surface of said first member;
an array of display element pixels supported by way of a second member positioned adjacent said first member, so that said array of variable capacitance pixels overlies said array of display element pixels, each of said display element pixels being selectively energized in response to control signals applied thereto; and
control means, coupled to said transparent array of variable capacitance pixels and said array of display element pixels, for scanning said transparent array of pixels and selectively causing a prescribed control signal to be coupled to a respective display element pixel corresponding to a respective variable capacitance pixel at which a change in capacitance has been detected.
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Accused Products
Abstract
A graphics input/output device contains a graphics input pad having an array of transparent capacitive pixels the capacitance characteristics of which are changed in response to the passing of a conductive-tipped stylus over the surface of the pad. This change in capacitance is sensed by sense buffers disposed along the columns of the matrix, as the rows are scanned at a prescribed scanning rate.
The sensed data is read out of the sense buffer and loaded into a RAM. An array of display pixels formed of an LCD matrix is addressed by a scan sequence control unit, and the energization of the display pixels is multiplexed with the read-out scanning of the sensed data, so as to present to the user a real time generated image of the graphics created by the stylus. As a result, it appears to the user that the stylus is actually "writing" on the display pad.
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Citations
30 Claims
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1. A display device comprising:
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a transparent array of variable capacitance pixels supported by way of a first member, each variable capacitance pixel undergoing a change in capacitance in response to the coupling of a conductive medium at the surface of said first member; an array of display element pixels supported by way of a second member positioned adjacent said first member, so that said array of variable capacitance pixels overlies said array of display element pixels, each of said display element pixels being selectively energized in response to control signals applied thereto; and control means, coupled to said transparent array of variable capacitance pixels and said array of display element pixels, for scanning said transparent array of pixels and selectively causing a prescribed control signal to be coupled to a respective display element pixel corresponding to a respective variable capacitance pixel at which a change in capacitance has been detected. - 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, 27, 28, 29)
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30. A variable capacitance transducer device comprising:
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a substrate upon which is provided a matrix of variable capacitance elements configured of a first and second layer of selectively formed conductive regions spaced apart from one another by a thin layer of dielectric material therebetween; means for selectively applying an electrical signal to rows of conductive regions of which one of said layers if formed; and means, coupled to each of the columns of conductive regions of which the other of said conductive layers is formed, for detecting a change in the capacitance between said first and second layers in response to the coupling of a conductive medium to said layers while said electrical signal is applied by said first means; and
whereineach of said layers is formed of transparent conductive material, thereby forming a matrix of capacitive pixels; and
whereina column of capacitance pixels is formed of a plurality of relatively large area conductive regions disposed successively adjacent to one another, and a plurality of relatively small area conductive regions successively interleaved with and joining together the relatively large area conductive regions; and
whereina row of capacitance pixels is formed of a plurality of relatively large area conductive regions disposed successively adjacent to one another, and a plurality of relatively small area conductive regions successively interleaved with and joining together the relatively large area conductive regions, and wherein the relatively large area rgions of the rows and columns are interleaved with one another, while the relatively small area conductive regions of the rows and columns overlap one another.
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Specification