摘要 |
<p>Apparatus for detecting the position of an object, e.g. for interaction with a computer graphic display, has a number of light emitting diodes in an endless array, and a lesser number of light detecting devices for providing electrical signals in response to momentary and successive energization of the light emitting diodes. The signals are electronically processed to provide cartesian co-ordinates. This apparatus provides high resolution with a minimum number of light detecting devices and enables too large objects and malfunctions to be readily detected.</p> |