Patent ID: 8587535

Claim:
A pointer position detection apparatus, comprising: (a) a 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; (b) a code string signal production circuit configured to produce a plurality of signals based on a plurality of code strings that are orthogonal to each other; (c) a transmission conductor selection circuit configured to selectively supply the plurality of signals produced by the code string signal production circuit to the plurality of first conductors, the transmission conductor selection circuit being further configured to divide the plurality of first conductors into a plurality of transmission blocks each including at least two first conductors, and to select one transmission block among the plurality of transmission blocks to supply the plurality of signals produced by the code string signal production circuit simultaneously to those first conductors in the selected transmission block; (d) a reception conductor selection circuit configured to selectively receive signals from the plurality of second conductors generated in response to the plurality of signals supplied to the plurality of first conductors, the reception conductor selection circuit is further configured to divide the plurality of second conductors into a plurality of detection blocks each including at least two second conductors, and to receive signals from the second conductors per each detection block as a unit; (e) a signal detection circuit configured to detect a signal corresponding to a variation of capacitance between the conductor pattern and a pointer, based on the signals received from the second conductors per each detection block via the reception conductor selection circuit, the signal detection circuit being configured to process the signals, which are received from the second conductors per each detection block, as a unit; (f) an analog to digital conversion circuit configured to convert the signal output from the signal detection circuit into a digital signal comprising a word string formed of a plurality of bits; (g) a correlation detection circuit configured to determine correlation values between code strings provided for correlation and the digital signal comprising a word string formed of a plurality of bits output from the analog to digital conversion circuit; (h) a memory circuit configured to store the correlation values output from the correlation detection circuit; and (i) a position calculation circuit configured to calculate a position on the conductor pattern pointed to by the pointer based on the correlation values.