Patent ID: 8466890

Claim:
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.