| 摘要 |
A touch sensitive device is provided having a laminar light guide 10, inside which light from source, such as the screen of a CRT 20 can become trapped by total internal reflection after reflection from a finger. The edges of the guide 10 are fitted with photodetectors 101 which respond to the entrapment of light between the surfaces. It is possible, by comparing the photodetector output with the CRT raster position, to determine the exact surface position of the touch. Alternatively a flexible transparent membrane over the light guide may be pressed in contact therewith by the finger. Other wave energy may replace light. <IMAGE> |
