摘要 |
A joystick including two light gratings respectively and fixedly mounted on an X-axle and a Y-axle, which are arranged at right angles to each other are movable by an operating stick. Each light grating has a series of apertures equally spaced along the periphery thereof. A light emitter and receiver assembly is disposed about said apertures in each said light grating to detect movement of the light grating, and a control circuit receiving signals from the light emitter and receiver assemblies provides a variable delay output signal corresponding to the movement of the operating stick. <IMAGE> |