| 摘要 |
A light pen input system includes a light sensing device (10) having a row and column array of light sensing elements (14) over which a light pen (12) is moved to write in information, e.g. for display on a display screen, the light beam emitted by the pen producing a light spot (20) on the array which covers, and is sensed by, adjacent elements and which, with the beam directed perpendicularly to the array, is substantially non-circular in shape, having dimensions in two directions over the array which differ from one another. Rotation of the pen around its axis is then detectable, providing additional functionality. An elongated light spot, e.g. elliptical, rectangular or triangular, provides further capabilities in enabling the width of a written stroke to be varied by twisting the pen. |
