Patent ID: 6118496
Filing Date: 2000-09-12
Classification: G11B,H04N

Abstract:
An automatic switching audio/video output circuit for automatically selecting one of a plurality of audio/video equipment and comprising:a video input interface having a plurality of signal input terminals for receiving video signals from a plurality of audio/video equipment, and a plurality of signal output terminals;at least one audio input interface each having a plurality of signal input terminals for receiving audio signal from a plurality of audio/video equipment and a plurality of signal output terminals;at least one analog/digital converter respectively connected to the signal output terminals of said video input interface for converting video signals into corresponding digital signals;a central processing unit (CPU) having a plurality of signal input pins respectively connected to respective signal output terminals of said at least one analog/digital converter for receiving the digital signals from said analog/digital converter, the CPU determining a last digital signal received and generating a control signal through a control signal output pin;an analog electronic switch unit having a plurality of signal input terminals respectively connected to the signal output terminals of said video input interface and the signal output terminals of said at least one audio input interface, a plurality of signal output terminals, and a control terminal connected to the control signal output pin of said CPU to receive the control signal from said CPU for controlling the closing/opening of the plurality of signal output terminals of said electronic switch unit;a video output amplifier having a video signal input terminal respectively connected to the signal output terminals of said analog electronic switch unit to receive video signals from said analog electronic switch unit, and a video signal output terminal; andan audio output amplifier having a signal input terminal respectively connected to the signal output terminal of said analog electronic switch unit to receive audio signals from said analog electronic switch unit and a plurality of audio signal output terminals;whereby the analog electronic switch unit outputs video/audio signals from the video/audio equipment corresponding to the last digital signal determined by the CPU.