Patent attributes
A coordinate-capturing apparatus suitable for inputting handwritten characters or diagrams to a computer or a printer is disclosed. The apparatus includes an ultrasonic transmitter mounted on an input pen for transmitting ultrasonic waves, two ultrasonic receivers for receiving ultrasonic waves transmitted form the ultrasonic transmitter, and a distance calculating device for calculating distances between the input pen and the two ultrasonic receivers in order to determine coordinates representing a position of the input pen on the basis of the calculated distances. The apparatus of the invention can perform coordinate detection smoothly even when the input pen moves fast, and has reduced electric power consumption in the input pen to increase the life-span of a battery included in the input pen.
