CHANNEL DETECTING DEVICE, AND TUNER TESTING DEVICE HAVING THE CHANNEL DETECTING DEVICE

摘要

An improved channel detecting apparatus is provided for detecting a channel. The channel detecting apparatus comprises a channel search circuit (3). When a certain frequency is detected through a search sweep using a frequency sweep signal for a channel, the channel search circuit determines whether or not the detected frequency falls within a frequency range associated with the channel. The channel search circuit (3) comprises a controller (32). The controller can comprise a sweep stop timing circuit (320) and a sweep resume timing circuit (322). The sweep stop timing circuit (320) stops the search sweep when the output of the channel is generated in response to the search sweep using a frequency sweep signal. The sweep resume timing circuit (322) resumes the search sweep by determining that the detected frequency does not fall within the frequency range associated with the channel when a level of the output of the channel generated in response to the frequency sweep signal fixed at the detected frequency is below a threshold.