Patent ID: 7760194
Filing Date: 2010-07-20
Classification: G06F

Abstract:
1. An ultrasonic coordinate input apparatus comprising: a transmitter capable of transmitting an ultrasonic wave; and a receiver detecting a position, based on the ultrasonic wave received from the transmitter, while synchronizing with the transmitter, the transmitter is connected to the receiver with a communication line via which the transmitter and the receiver bi-directionally communicate with each other, the receiver comprising a transmission time calculator that calculates a time required for ultrasonic wave transmission from the transmitter to the receiver, and the transmitter comprising a cycle adjuster that adjusts a cycle of transmitting the ultrasonic wave in accordance with a relation between a comparison of a first time difference and a second time difference and a predetermined coordinate movement value, a time difference being defined as a difference between a time of reception of a transmitted ultrasonic wave and a time of reception of a synchronization signal.