Cursor controller comparing voltages from intermittent optical signals

摘要

The cursor controller is built into a shell (20) with transmission of movement by a rolling ball (21). The direction of movement is detected using a microprocessor (232) to process the signal from a phototransistor (2312). It is exposed to light from an LED (22) through a grating wheel (231) with an anti-dispersion mask (24). The openings (23111-23113) in the grating have different areas. Hence the phototransistor produces a sequence of voltages dependent upon the direction in which the cursor is to be moved.