Abstract: An interactive visual communications system consists of a number of similar terminals linked together by narrow band communications links. Each terminal consists of visual display apparatus having a display and a display generator, an input interactive device for providing input instructions which are converted to graphic task instructions at the terminal, a processor for processing such graphic task instructions (GTI's) to control the display system and the input interactive device. The generated graphic task instructions are directed through an interaction handler which directs the GTI's to the processor as well as to a modem for transmission over the narrow band communications link to one or more similar terminals. In addition, the interaction handler receives GTI's from the other terminals which are also processed by the processor to control the display system. The display system may include a random vector display monitor or a raster graphic display monitor.

Abstract: 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.