Patent ID: 7388622
Filing Date: 2008-06-17
Classification: H03B,H03J

Abstract:
1. A television tuner comprising: a tuning circuit, which is tuned to a television signal to be received; a mixer for converting the television signal into an intermediate frequency signal; and an oscillator for supplying to the mixer a local oscillating signal, frequency of which is changed in accordance with tuning frequency of the tuning circuit, wherein a first varactor diode for changing the tuning frequency is provided at the tuning circuit, a second varactor diode for changing an oscillating frequency is provided at the oscillator, a tuning voltage between both ends of the first varactor diode becomes equal to the tuning voltage between both ends of the second varactor diode when the television tuner receives a television signal, and the tuning voltage between both ends of the first varactor diode becomes lower than the tuning voltage between both ends of the second varactor diode when the television tuner receives a FM broadcasting signal.