Photo-stylus system for writing on TV screen - has microprocessor controlled TV sweep generator cooperating with stylus producing coordinate pulses which are stored in memory

摘要

The system enables a user to write on a t.v. screen (1) using a photostylus (2) and a microprocessor (3) which is coupled to a t.v. sweep generator (4) in turn coupled to the t.v. and a translator which increases the luminosity or colour level of the screen. The photostylus generator T and P pulses respectively when it touches the screen and when the t.v. electron beam sweeps past the photostylus. There signals are separated in the microprocessor and applied to a memory (23) for recorded and a function controller (30) which can be preset by the user to carry out functions such as erase, write and colour selection. The signals are applied to the generator (4) to display, where applicable, the information written onto the screen by the photostylus. The translator is controlled by the sweep generator and only increases the screen luminance or colour level during sweep of the t.v. electron beam in response to the signals from the microprocessor.