Pointing or indicating equipment with photodetector arrangement

摘要

The figure shows the general picture, the tracking ball unit (10), its upper housing (20), a printed circuit board (30), the ball holder (40), its lower housing (50), the ball or sphere itself (60), a number of keys on the upper housing and these activate the switches (80). The ball holder is usually mounted on the printed circuit board which contains circuits for processing the signals from the sensors and the logic units. A movement of the ball in its holder is converted into digital signals controlling the movement of the cursor of the screen of a pc. or work station. If the equipment has a serial post, there will be a microprocessor and a driving circuit for sending and receiving signals.