COORDINATE INPUT DEVICE FOR PEN INPUT

摘要

PURPOSE:To surely receive the signal from a pen through simple constitution by radiating an ultrasonic wave from the upper end of the pen downward equally to the whole circumference and detecting the ultrasonic wave by a receiving sensor which is provided at the peripheral part of the coordinate input device. CONSTITUTION:The cordless pen 11 detects and inputs the coordinates of a touched position on the coordinate input device 21 and inputs various instructions with its click button 12 depressed. An ultrasonic wave transmitter 13 sends the ultrasonic wave from the upper end of the pen 11 in response to the depression of the click button 12 and a reflecting plate 14 reflects the ultrasonic wave downward to the whole outer periphery of the pen 11. The receiving sensor 22 arranged at the outer peripheral part of the coordinate input device 21 detects the ultrasonic wave radiated from the upper end of the pen 11. Thus, the ultrasonic wave is radiated downward from the upper end of the pen 11 equally to the whole periphery and detected by the receiving sensor 22 provided at the outer peripheral part of the coordinate input device 21, so that the receiving sensor 22 can detect the ultrasonic wave without being disturbed by an obstacle.