Light Emitting Diode Dot Matrix Display System With Audio Output

Abstract

A Dot Matrix Display System Made Up Of Light Emitting Diodes (Led's), N Which One Or More Leds Are Modulated And Encoded With Audio Information Or Messages Is Disclosed. The System Has A Led Dot Matrix Display Panel With An Interface Circuit To A Computer, An Audio Signal Transmitter, And A Receiver. An Executive Program Runs On The Computer For The Visual Display Control Of Characters, Decorative Pattern Or Messages On The Display Panel. The Receiver Combined With A Speaker Is Located At A Distance From The Display Panel. The Receiver Is Designed To Demodulate The Optically Transmitted Audio Information And Broadcast The Messages With The Speaker. The Modulation Of The Leds Includes A Voltage-Controlled Oscillator (Vco) For Varying The Frequency Of On/Off Periods Of Said Light Emitting Diodes. The Frequency Is High Enough Such That The Perceivable Light Appears To Be Constantly Illuminated To The Human Eye.