Patent ID: 7336262
Filing Date: 2008-02-26
Classification: G06F

Abstract:
1. A coordinate-capturing apparatus comprising: (a) an input device that transmits a position-detecting signal and a timing signal; (b) a position detecting device comprising: first and second position-detecting signal receivers for receiving said position-detecting signal; a timing signal receiver for receiving said timing signal; a distance calculating device calculating distances between said input device and said first and second position-detecting signal receivers upon receiving said timing signal; said position detecting device calculating a first position of said input device on the basis of timing of reception of said position-detecting signal when said timing signal is received, and calculating a second position of said input device on the basis of information on periodicity of said position-detecting signal, information on a state of reception of said position-detecting signal, and said first position; a coordinate calculating device for calculating coordinates representing a position of said input device on the basis of said distances calculated by said distance calculating device; and a distance variation calculating device for calculating variations of said distances between said input device and said first and second position-detecting signal receivers on the basis of time periods between receptions of said position-detecting signal transmitted from said input device at a first time by said first and second position-detecting signal receivers respectively and receptions of said position-detecting signal transmitted from said input device at a second time by said first and second position-detecting signal receivers respectively; in which said information on periodicity is a first time interval at which said position-detecting signal is transmitted, and said information on a state of reception is a second time interval at which said position-detecting signal is received.