Input device
First Claim
1. An input device for a visual display screen, the device comprising a first assembly including:
- a source of diverging light comprising rays directed substantially parallel to the surface of the screen, said rays substantially covering the screena shutter disposed to interrupt a portion of said light before it reaches the screen, said shutter comprising an array of shutter elements, each element having a unique address, further wherein each element has a transparent state in which light from said light source is transmitted and an opaque state in which light from said light source is blocked;
shutter drive circuit means coupled to said shutter elements for controlling the state of each of said shutter elements so as to provide a scanning light beam as an output of said shutter; and
a photodetector for detecting interruption of said light beam by an article positioned in the plane and for providing a first output signal upon detecting said interruption of said light beam.
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Accused Products
Abstract
An input device for a visual display comprising a light source and a scanner for angularly scanning a light beam from the light source across a plane. A photodetector detects interruption of the beam by an article positioned in the plane. The scanner comprises a shutter having a linear array of addressable, electrically actuable shutter elements. Each element is operable to transmit or block light from the light source under the control of a corresponding electrical signal. Because the light beam is scanned by a shutter rather than a mechanical scanner, the device is advantageously more reliable than conventional electromechanical optical input devices.
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Citations
27 Claims
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1. An input device for a visual display screen, the device comprising a first assembly including:
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a source of diverging light comprising rays directed substantially parallel to the surface of the screen, said rays substantially covering the screen a shutter disposed to interrupt a portion of said light before it reaches the screen, said shutter comprising an array of shutter elements, each element having a unique address, further wherein each element has a transparent state in which light from said light source is transmitted and an opaque state in which light from said light source is blocked; shutter drive circuit means coupled to said shutter elements for controlling the state of each of said shutter elements so as to provide a scanning light beam as an output of said shutter; and a photodetector for detecting interruption of said light beam by an article positioned in the plane and for providing a first output signal upon detecting said interruption of said light beam. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18)
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19. A scanner for angularly scanning a light beam, said scanner comprising:
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a source of diverging light a shutter disposed to interrupt a portion of said light, said shutter comprising an array of shutter elements, each element having a unique address, further wherein each element has a transparent state in which light from said light source is transmitted and an opaque state in which light from said light source is blocked; and shutter drive circuit means coupled to said shutter elements for controlling the state of each of said shutter elements so as to provide a scanning light beam as an output of said shutter. - View Dependent Claims (20, 21, 22, 23, 24, 25)
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26. A visual display comprising a visual display screen and an input device, said device comprising a first assembly including:
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a source of diverging light comprising rays directed substantially parallel to the surface of the screen, said rays substantially covering the screen a shutter disposed to interrupt a portion of said light before it reaches the screen, said shutter comprising an array of shutter elements, each element having a unique address, further wherein each element has a transparent state in which light from said light source is transmitted and an opaque state in which light from said light source is blocked; shutter drive circuit means coupled to said shutter elements for controlling the state of each of said shutter elements so as to provide a scanning light beam as an output of said shutter; and a photodetector for detecting interruption of said light beam by an article positioned in the plane and for providing a first output signal upon detecting said interruption of said light beam.
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27. A system comprising a processor and a visual display, said display comprising a visual display screen and an input device, said device comprising a first assembly including:
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a source of diverging light comprising rays directed substantially parallel to the surface of the screen, said rays substantially covering the screen a shutter disposed to interrupt a portion of said light before it reaches the screen, said shutter comprising an array of shutter elements, each element having a unique address, further wherein each element has a transparent state in which light from said light source is transmitted and an opaque state in which light from said light source is blocked; shutter drive circuit means coupled to said shutter elements for controlling the state of each of said shutter elements so as to provide a scanning light beam as an output of said shutter; and a photodetector for detecting interruption of said light beam by an article positioned in the plane and for providing a first output signal upon detecting said interruption of said light beam.
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Specification