Television tuner

Abstract

Disclosed is a television tuner for receiving television broadcast signals with an antenna, which is equipped with an auto-scan unit that causes a channel storing section, which stores a receiving channel at the time when the signal condition from a tuner section matches the predetermined signal condition, to automatically store the receiving channel, wherein the auto scan unit detects switches among the receiving channel sequentially in the tuner section to detect the signal condition, and, after signal condition is detected for every channel, performs a variable directivity control for the antenna, resulting in an increased auto-scan execution speed.

1 . A television tuner that receives television broadcast signals with a smart antenna capable of statically selecting a directivity by means of an electric signal, comprising: 
 a directivity control section that outputs an electric signal to select the directivity of the smart antenna;    a tuner section that receives television broadcast signals in the predetermined band with the smart antenna;    a signal condition detector section that detects the signal condition of a signal from the tuner section by detecting the AGC voltage specifying the gain of a signal from the tuner and/or the bit error rate of a digital signal from the tuner section; and    a channel storing section that stores the receiving channel and the receiving direction of the smart antenna at the time when the signal condition of a signal detected by the signal condition detector section matches the predetermined signal condition, by making them corresponding to each other, wherein:    an auto-scan unit is provided that causes the channel storing section to automatically store a plurality of receiving channels; and    an auto-scan unit switches the receiving channels at the tuner section sequentially for the receiving channels except for the receiving channels stored in the channel storing section, causes the signal condition detector section to detect the signal condition for each receiving channel, and, after signal condition is detected for every receiving channel by the signal condition detector section, causes a directivity control section to perform a variable directivity control for the antenna.    
     
     
         2 . A television tuner that receives television broadcast signals with an antenna capable of selecting the directivity, comprising: 
 a directivity control section that outputs an electric signal to select the directivity of the antenna;    a tuner section that receives television broadcast signals in the predetermined band with the antenna;    a signal condition detector section that detects the signal condition of a signal output from the tuner section; and    a channel storing section that stores the receiving channel when the signal condition of a signal detected by the condition signal condition detector section matches the predetermined signal condition, wherein:    an auto-scan unit is provided that causes the channel storing section to automatically store a plurality of receiving channels; and    the auto-scan unit switches among the receiving channels sequentially for the plurality of receiving channels, causes the signal condition detector section to detect the signal condition for each receiving channel, and, after signal condition is detected for every receiving channel by the signal condition detector section, causes the directivity control section to perform a variable directivity control for the antenna.    
     
     
         3 . The television tuner according to  claim 2 , wherein the auto-scan unit, after a receiving channel is stored in the channel storing section, will not make a switch to the receiving channel thereafter.  
     
     
         4 . The television tuner according to  claim 2 , wherein the channel storing section stores the receiving channel and the receiving direction of the antenna at the time when the signal condition of a signal detected by the signal condition detector section matches the predetermined signal condition.  
     
     
         5 . The television tuner according to  claim 2 , wherein: 
 the antenna is a smart antenna capable of statically selecting the directivity by means of an electric signal; and    the antenna control section outputs an electric signal to statically select the directivity of the smart antenna.    
     
     
         6 . The television tuner according to  claim 2 , wherein the signal condition detector section is an AGC circuit that detects the AGC voltage specifying the gain of a signal from the tuner section.  
     
     
         7 . The television tuner according to  claim 2 , wherein the signal condition detector section is a demodulator circuit that detects the bit error rate of a digital signal from the tuner.