Tilt derivation device and tilt derivation method

摘要

PROBLEM TO BE SOLVED: To provide a gradient derivation apparatus for accurately deriving gradient of a pointer with low computational complexity, and a gradient derivation method.SOLUTION: In a gradient derivation apparatus for detecting a position pointed by a pen-type pointer, the pointer includes a first electrode arranged at one axial end, a second electrode arranged around an axis, a planar sensor for detecting a position of the first electrode and a position of the second electrode, and a control unit 10. The control unit 10 includes: a lookup table 15 (15A, 15B, 15C) formed by registering correspondence between a value based on a difference between the positions of the first and second electrodes and a correction value which is a basis for a gradient of the axis of the pointer; an input value calculation unit 14 (14A, 14B) for calculating the value based on the difference to be input to the lookup table 15; and a gradient derivation unit 16 for deriving gradient from the correction value which is a basis for the gradient output from the lookup table 15.SELECTED DRAWING: Figure 3