Electro-optical mouse with improved resolution for compensation of optical distortion
First Claim
1. A position control system for a cursor, comprising:
- (a) a surface having a repetitive pattern of passive, optically contrasting indicia extending over said surface, said pattern being comprised of spaced regions of a first optical characteristic substantially surrounded by at least one region of a second optical characteristic;
(b) a housing means movable in a plane substantially parallel to said surface and having a base with an opening formed therein, said opening facing said surface during movement of said housing in said plane;
(c) light-emitting means mounted within said housing and directed at said opening;
(d) light-detecting means mounted within said housing and positioned for receiving light passing through said opening, said light-detecting means outputting a voltage signal substantially proportional to the amount of light impinging on said light-detecting means;
(e) means for generating a plurality of reference voltage signals, each of said reference voltage signals being substantially proportional to any one of a plurality of predetermined threshold voltage levels; and
(f) coding means electrically coupled to receive said voltage signals proportional to the amount of light received and said reference voltage signals, said coding means outputting a coded detector signal representing one of two binary digits in response to the amplitude of said voltage signal being greater than or equal to the amplitude of a generated reference voltage signal and outputting a coded detector signal representing the other of said two binary digits in response to the amplitude of said voltage signal being less than the amplitude of said generated reference voltage signal.
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Accused Products
Abstract
An electro-optical mouse has a four-quadrant photodetector, each quadrant producing a voltage proportional to the amount of light impinging thereon. The mouse slides over a surface having optically contrasting, i.e. reflecting and nonreflecting, indicia thereon. The position of the mouse relative to a coordinate system in the plane of the surface is determined by projecting light onto the surface and then detecting the amount of light reflected from the surface onto the respective quadrants. The mouse is able to detect within which of four ranges the amount of light impinging on each quadrant lies. A two-bit code indicating the range is generated for each quadrant, thereby forming an eight-bit detector code. In the case where the eight-bit detector code is the same, i.e., ambiguous, for two different positions of the mouse relative to an indicium being optically detected, the true position at a current instant in time is identified by interpolating between the position at a previous instant in time and the position at a subsequent instant in time. This look-ahead routine is performed after the predetermined ambiguous detector code has been recognized and after a determination has been made that the position at the previous instant in time was not at or in the vicinity of one of the two positions corresponding to the ambiguous detector code.
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Citations
35 Claims
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1. A position control system for a cursor, comprising:
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(a) a surface having a repetitive pattern of passive, optically contrasting indicia extending over said surface, said pattern being comprised of spaced regions of a first optical characteristic substantially surrounded by at least one region of a second optical characteristic; (b) a housing means movable in a plane substantially parallel to said surface and having a base with an opening formed therein, said opening facing said surface during movement of said housing in said plane; (c) light-emitting means mounted within said housing and directed at said opening; (d) light-detecting means mounted within said housing and positioned for receiving light passing through said opening, said light-detecting means outputting a voltage signal substantially proportional to the amount of light impinging on said light-detecting means; (e) means for generating a plurality of reference voltage signals, each of said reference voltage signals being substantially proportional to any one of a plurality of predetermined threshold voltage levels; and (f) coding means electrically coupled to receive said voltage signals proportional to the amount of light received and said reference voltage signals, said coding means outputting a coded detector signal representing one of two binary digits in response to the amplitude of said voltage signal being greater than or equal to the amplitude of a generated reference voltage signal and outputting a coded detector signal representing the other of said two binary digits in response to the amplitude of said voltage signal being less than the amplitude of said generated reference voltage signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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16. In a position control system for a cursor, comprising:
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(a) a surface having a repetitive pattern of passive, optically contrasting indicia extending over said surface, said pattern being comprised of spaced regions of a first optical characteristic substantially surrounded by at least one region of a second optical characteristic; (b) a housing means movable in a plane substantially parallel to said surface and having a base with an opening formed therein, said opening facing said surface during movement of said housing in said plane; (c) light-emitting means mounted within said housing and directed at said opening; (d) a plurality of light-detecting means mounted within said housing and arranged in an array for receiving light passing through said opening, each of said light-detecting means outputting a voltage signal substantially proportional to the amount of light impinging on said light-detecting means; (e) coding means electrically connected to said light-detecting means, said coding means outputting a plurality of binary-coded detector signals dependent on the corresponding magnitudes of said voltage signals; (f) sampling means for successively sampling said detector signals at a first sampling time, at a second sampling time subsequent to said first sampling time, and at a third sampling time subsequent to said second sampling time; (g) register means electrically connected to said sampling means for storing detector data representing said sampled detector signals; and (h) processing means electrically connected to said register means for retrieving said stored detector data from said register means and transforming said detector data into binary-coded step signals approximating the distance and direction traveled by said light-detecting array relative to said surface during the time intervals between said first and second sampling times, and between said second and third sampling times, said step signals being stored in said register means as incremental data, the improvement wherein after said third sampling time, said processing means derives step signals approximating distance and direction traveled by said array during the interval of time from said first sampling time to said second sampling time as a function of detector data sampled at said second sampling time. - View Dependent Claims (17, 18, 19, 20, 21, 22, 23, 24)
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25. A mouse for use in conjunction with a surface having a repetitive pattern of passive, optically contrasting indicia extending over said surface, said pattern being comprised of spaced regions of a first optical characteristic substantially surrounded by at least one region of a second optical characteristic;
- said mouse comprising;
(a) a housing means movable in a plane substantially parallel to said surface and having a base with an opening formed therein, said opening facing said surface during movement of said housing in said plane; (b) light-emitting means mounted within said housing and directed at said opening; (c) light-detecting means mounted within said housing and positioned for receiving light passing through said opening, said light-detecting means outputting a voltage signal substantially proportional to the amount of light impinging on said light-detecting means; (d) means for generating a plurality of reference voltage signals, each of said reference voltage signals being substantially proportional to any one of a plurality of predetermined threshold levels; and (e) coding means electrically coupled to receive said voltage signals proportional to the amount of light received and said reference voltage signals, said coding means outputting a coded detector signal representing one of two binary digits in response to the amplitude of said voltage signal being greater than or equal to the amplitude of a generated reference voltage signal and outputting a coded detector signal representing the other of said two binary digits in response to the amplitude of said voltage signal being less than the amplitude of said generated reference voltage signal. - View Dependent Claims (26)
- said mouse comprising;
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27. A mouse for use in conjunction with a surface having a repetitive pattern of passive, optically contrasting indicia extending over said surface, said pattern being comprised of spaced regions of a first optical characteristic substantially surrounded by at least one region of a second optical characteristic;
- said mouse comprising;
(a) a housing means movable in a plane substantially parallel to said surface and having a base with an opening formed therein, said opening facing said surface during movement of said housing in said plane; (b) light-emitting means mounted within said housing and directed at said opening; (c) a plurality of light-detecting means mounted within said housing and arranged in an array for receiving light passing through said opening, each of said light-detecting means outputting a voltage signal substantially proportional to the amount of light impinging on said light-detecting means; (d) coding means electrically connected to said light-detecting means, said coding means outputting a plurality of binary-coded detector signals dependent on the corresponding magnitudes of said voltage signals; (e) sampling means for sampling said detector signals at a first sampling time, at a second sampling time subsequent to said first sampling time, and at a third sampling time subsequent to said second sampling time; (f) register means electrically connected to said sampling means for storing detector data representing said sampled detector signals; and (g) processing means electrically connected to said register means for retrieving said stored detector data from said register means and transforming said detector data into binary-coded step signals approximating the distance and direction traveled by said light-detecting array relative to said surface during the time intervals between said first and second sampling times, and between said second and third sampling times, said step signals being stored in said register means as incremental data, the improvement wherein after said third sampling time said processing means derives step signals approximating the distance and direction traveled by said array during the interval of time from said first sampling time to said second sampling time as a function of detector data sampled at said second sampling time. - View Dependent Claims (28, 29, 30, 31, 32)
- said mouse comprising;
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33. An electro-optical mouse comprising means for generating a voltage substantially proportional to the amount of light impinging on a surface thereof, means for sequentially generating a first reference voltage and a second reference voltage greater than said first reference voltage, and means for producing a first code in response to said voltage being less than said first reference voltage, a second code different than said first code in response to said voltage being greater than said first reference voltage and less than said second reference voltage, and a third code different than said first and second codes in response to said voltage being greater than said second reference voltage
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34. An electro-optical mouse comprising means for approximating, at a given instant, the position that said mouse had relative to a surface at a first instant in time previous to said given instant wherein said means for approximating comprises means for interpolating between the position of said mouse at an instant in time previous to said first instant and the position of said mouse at an instant in time subsequent to said first instant but previous to said given instant to determine said approximated position.
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35. An electro-optical mouse comprising means for generating and storing first data approximating the position of said mouse relative to a surface at a first instant of time as a function of optical data acquired from said surface at said first instant of time and second data approximating the position of said mouse relative to said surface at a second instant of time subsequent to said first instant of time as a function of optical data acquired from said surface at said second instant in time, means for testing whether said first and second stored data have a predetermined forbidden relationship which is incompatible with a geometric pattern of optically contrasting indicia formed on said surface, and means for substituting said stored first data for said stored second data in response to said first and second stored data having said predetermined forbidden relationship.
Specification