Patent ID: 7525603
Filing Date: 2009-04-28
Classification: H01Q,H04N

Abstract:
1. A television tuner for receiving television signals using an antenna having directivity selected by an electrical signal, comprising: a directivity control section that outputs an electrical signal to select the directivity of the antenna, the directivity control section includes: plurality of directional antennas coupled with a plurality of phase shifter circuits, with a phase shifter circuit of the plurality of phase shifter circuits controlling a phase shift amount of a signal input from a directional antenna of the plurality of directional antennas and delaying a phase of the signal according to a bias voltage output from the television tuner to control the directivity of the directional antenna for any direction, including an axial direction of the directional antenna and for generating a directivity value; a tuner section that receives television signals in a given frequency band using the antenna and outputs an intermediate frequency (I/F) signal; a signal condition detector section that detects a signal condition of the I/F signal, with the signal condition based on a channel number of a channel and directivity value; if a frequency signal of the I/F signal is a digital frequency signal, the signal condition is determined by detecting a bit error rate; if the frequency signal of the I/F signal is an analog signal, the signal condition is determined by detecting an AGC voltage output; a channel storing section that stores the channel number of the channel and the directivity value of the directional antenna as a channel select data if the signal condition of the I/F signal is commensurate with a predetermined signal condition; if it is determined that the channel select data is stored, a video signal control processing is executed to display an image, after which, it is determined if a channel number change command is input; if it is determined that a channel number change command is input, a channel change processing is executed, otherwise, if it is determined that a channel number change command is not input, it is determined if auto-scan start command is input; if it is determined that the auto-scan start command is input, the auto scan processing is executed; the change channel processing includes: the tuner section receiving data corresponding to a newly selected channel number; the directivity value of the antenna is set to a first directivity value using phase shifter circuits; the signal condition detector section detects a new signal condition of a new I/F signal, with the new signal condition based on the newly selected channel number and the set directivity value; determining if the detected signal condition is commensurate with a predetermined signal condition; if the detected signal condition is not commensurate with the predetermined signal condition, determining if the set directivity value is less than a predetermined directivity value; if it is determined that the set directivity value is less than a predetermined directivity value, incrementing the directivity value and detecting the signal condition based on the incremented directivity value and the new channel number.