Patent ID: 6140999
Filing Date: 2000-10-31
Classification: G06F

Abstract:
A coordinate input device, which detects a signal outputted from a coordinate input pen on the surface of a tablet and converts it into coordinate data, comprising:a setting device for allowing an operator to set and select a color among virtually limitless kinds of colors;a phase-conversion circuit for shifting the phase of an ac signal from a device main body based upon the setting and selection by the operator made via the setting device, and for outputting the resulting signal to the coordinate input pen;an amplification circuit for amplifying the phase-shifted ac signal;a phase-difference detection circuit for detecting the phase difference between the signal amplified by the amplification circuit and the ac signal from the device main body;a storage device for storing color information used for carrying out conversion to respective colors that have been preliminarily set in association with values of the phase difference; anda color conversion circuit for outputting, together with coordinate data, a specific piece of color information that corresponds to the phase difference that has been detected by the phase-difference detection circuit from pieces of color information that have been preliminarily stored in the storage in association with phase differences.