초록 ▼

A touch sensitive device is arranged with substantially parallel surfaces inside which light from a synchronized source, such as a CRT, can become trapped by total internal reflection. The edges of the device are fitted with photodetectors which respond to the entrapment of light within the surfaces

A touch sensitive device is arranged with substantially parallel surfaces inside which light from a synchronized source, such as a CRT, can become trapped by total internal reflection. The edges of the device are fitted with photodetectors which respond to the entrapment of light within the surfaces. The top surface is arranged so that a touch of the device at a particular point will cause a medium change on the surface at that point. The medium change causes light to become entrapped within the surface by total internal reflection thus making it possible, by comparing the photodetector output with the CRT raster position, to determine the exact surface position of the touch. Using this arrangement, positional determination is uneffected by raster drift.

대표청구항 ▼

A touch sensitive device for use in conjunction with a signal source, said device comprising spaced apart surfaces arranged such that signals are introduced between said surfaces so as to become entrapped within said device by total internal reflection between said surfaces as a result of a touch of

A touch sensitive device for use in conjunction with a signal source, said device comprising spaced apart surfaces arranged such that signals are introduced between said surfaces so as to become entrapped within said device by total internal reflection between said surfaces as a result of a touch of one of said surfaces, and signal utilization means communicating with a region between said surfaces so as to provide a distinctive output when said signals are so introduced between said surfaces.