Patent ID: 7596466

Claim:
An inclination calculation apparatus for sequentially calculating an inclination of an input device operable in terms of a posture thereof, wherein the input device includes an acceleration detector for detecting an acceleration in at least two axial directions and an imaging element for taking an image of two imaging targets, the inclination calculation apparatus comprising: an image information processor for sequentially calculating first inclination information representing an inclination of the input device from positions of the two imaging targets in a taken image obtained by the imaging element; an acceleration information processor for sequentially calculating second inclination information representing an inclination of the input device from an acceleration detected by the acceleration detector; and an inclination calculator for calculating an inclination of the input device using the first inclination information and the second inclination information; wherein the inclination calculator selects one of a calculation method using the first inclination information and a calculation method using the second inclination information, and calculates the inclination of the input device by the selected calculation method.