Wireless Cursor-Control Device
Original Publication Date: 1984-Jul-01
Included in the Prior Art Database: 2005-Feb-04
A display cursor-control system includes a remote position sensing device which includes an ultrasonic wave transmitter, an ultrasonic wave receiver and a battery pack for powering the transmitter and receiver. A base station connected to a display workstation includes an ultrasonic transmitter and two ultrasonic receivers. Base station 10 includes controller 12, counter 1 (14) and counter 2 (16) as well as ultrasonic transmitter 18 and ultrasonic receiver 1 (20) and ultrasonic receiver 2 (22). Controller 12 generates a start signal which initiates counting in counter 1 and counter 2 and causes generation of an ultrasonic signal by transmitter 18. The ultrasonic signal transmitted by transmitter 18 is generally in the form of a pulse modulated to provide a unique polling signal to the position sensing device 30.