Pointer detection apparatus and pointer detection method
First Claim
1. A pointer detection apparatus for detecting a pointer positioned on a conductor pattern, the conductor pattern including a plurality of first conductors disposed in a first direction and a plurality of second conductors disposed in a second direction which crosses the first direction, the pointer detection apparatus comprising:
- a code supplying circuit having a plurality of code strings, each code string having a n-code length and the code strings being constructed from a Hadamard matrix and mutually orthogonal to each other, the code supplying circuit being configured to supply predetermined ones of the code strings to the first conductors disposed in the first direction;
a correlation calculation code supplying circuit configured to supply correlation calculation codes respectively corresponding to the code strings; and
a correlation calculation circuit for carrying out correlation calculation between signals produced in the second conductors disposed in the second direction and the correlation calculation codes;
wherein the pointer positioned on said conductor pattern is detected based on results of the correlation calculation carried out by said correlation calculation circuit;
wherein one of the code strings constructed from the Hadamard matrix is not supplied to the first conductors, so as not to be subjected to a variation factor introduced by the first conductors and the second conductors, to be thereby used to produce a reference signal for the correlation calculation to detect the pointer positioned on the conductor pattern.
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Accused Products
Abstract
A pointer detection apparatus and a pointer detection method of the cross point electrostatic coupling type are disclosed, by which a pointer on a conductor pattern can be detected at a higher speed. The pointer detection apparatus includes a conductor pattern, a spread code supplying circuit, a reception conductor selection circuit, an amplification circuit, an analog to digital conversion circuit, and a correlation value calculation circuit. The spread code supplying circuit supplies a plurality of spread codes at the same time. The correlation value calculation circuit determines correlation values between signals output from the analog to digital conversion circuit and the correlation calculation codes respectively corresponding to the spread codes. A pointer is detected based on the determined correlation values.
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Citations
35 Claims
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1. A pointer detection apparatus for detecting a pointer positioned on a conductor pattern, the conductor pattern including a plurality of first conductors disposed in a first direction and a plurality of second conductors disposed in a second direction which crosses the first direction, the pointer detection apparatus comprising:
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a code supplying circuit having a plurality of code strings, each code string having a n-code length and the code strings being constructed from a Hadamard matrix and mutually orthogonal to each other, the code supplying circuit being configured to supply predetermined ones of the code strings to the first conductors disposed in the first direction; a correlation calculation code supplying circuit configured to supply correlation calculation codes respectively corresponding to the code strings; and a correlation calculation circuit for carrying out correlation calculation between signals produced in the second conductors disposed in the second direction and the correlation calculation codes; wherein the pointer positioned on said conductor pattern is detected based on results of the correlation calculation carried out by said correlation calculation circuit; wherein one of the code strings constructed from the Hadamard matrix is not supplied to the first conductors, so as not to be subjected to a variation factor introduced by the first conductors and the second conductors, to be thereby used to produce a reference signal for the correlation calculation to detect the pointer positioned on the conductor pattern. - 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, 29, 30, 33)
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27. A pointer detection apparatus for detecting a pointer positioned on a conductor pattern, the conductor pattern including a plurality of first conductors disposed in a first direction and a plurality of second conductors disposed in a second direction which crosses the first direction, the pointer detection apparatus comprising:
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a code supplying circuit having a plurality of code strings, each code string having a n-code length and the code strings being constructed from a Hadamard matrix and mutually orthogonal to each other, the code supplying circuit being configured to supply predetermined ones of the plurality of code strings to the first conductors disposed in the first direction; and a correlation calculation circuit configured to carry out correlation calculation between signals produced in the second conductors disposed in the second direction and correlation calculation codes respectively corresponding to the code strings; wherein the pointer positioned on said conductor pattern is detected based on correlation calculation values determined by said correlation calculation circuit; wherein one of the code strings constructed from the Hadamard matrix is not supplied to the first conductors, so as not to be subjected to a variation factor introduced by the first conductors and the second conductors to be thereby used to produce a reference signal for the correlation calculation to detect the pointer positioned on the conductor pattern. - View Dependent Claims (34, 35)
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28. A pointer detection method for detecting a pointer positioned on a conductor pattern, the conductor pattern including a plurality of first conductors disposed in a first direction and a plurality of second conductors disposed in a second direction which crosses the first direction, the method comprising:
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a code supplying step for supplying predetermined ones of a plurality of code strings to the first conductors disposed in the first direction, each code string having a n-code length and the code strings being constructed from a Hadamard matrix and mutually orthogonal to each other; a correlation calculation code supplying step for supplying correlation calculation codes respectively corresponding to the code strings; a correlation calculation processing step for carrying out correlation calculation between signals produced in the second conductors disposed in the second direction and the correlation calculation codes; a position detection step for detecting the pointer positioned on the conductor pattern based on results of the correlation calculation carried out at the correlation calculation processing step; wherein the code supplying step includes not supplying one of the code strings constructed from the Hadamard matrix to the first conductors, so as not to subject said one code string to a variation factor introduced by the first conductors and the second conductors to thereby use said one code string to produce a reference signal for the correlation calculation to detect the pointer positioned on the conductor pattern. - View Dependent Claims (31, 32)
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Specification