Auto-selecting circuit of an intermediate frequenc

专利名称：Auto-selecting circuit of an intermediate

frequency

发明人：Young Pyo Hong申请号：US08/352625申请日：19941209公开号：US05574997A公开日：19961112

摘要：A circuit for automatically selecting an intermediate frequency which includes asingle tuner having a plurality of local oscillators. The circuit amplifies a channelfrequency received by an antenna and mixes it with a local oscillating frequency outputfrom a designated local oscillator to output an intermediate frequency. The circuit alsohas a microprocessor which outputs a control signal to select a local oscillator for aparticular broadcasting system from among the plurality of local oscillators, a switchingcircuit which selects an oscillating frequency of the designated local oscillator accordingto the control signal output from the microprocessor and outputs it to the mixer of thetuner, and a detector of an intermediate frequency which amplifies the intermediatefrequency of the tuner to detect image signals and sound signals. The plurality of localoscillators for particular broadcasting systems are equipped in a single tuner, and anoscillating frequency output from a local oscillator suitable for a particular broadcastingsystem is selected. Cost of manufacture can be reduced, the circuit structure can besimplified, and the size of the receiving apparatus can be miniaturized because theintermediate frequency suitable for a particular broadcasting system is automaticallyoutput from a single tuner.

申请人：SAMSUNG ELECTRONICS CO., LTD.

代理机构：Sughrue, Mion, Zinn, Macpeak & Seas

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