| 摘要 |
PURPOSE:To start of a station to be searched from a minimum tuning voltage, by changing a band to the VHF-LOW, after reaching a maximum tuning voltage of a UHF band, when an automatic station research operation is executed, while a TV station of the VHF-LOW band received at a minimum tuning voltage is under broadcasting. CONSTITUTION:When a TV signal possible for the reception with a minimum tuning voltage (m) at the VHF-LOW band is inputted to an antenna input, a changeover switch 28 is closed and a trigger switch 27 is further turned on with the state of j=+B, the state of i=+B is instantly obtained to bring an automatic station search processing circuit 32 into the station search state. Thus, a signal (l) and the tuning voltage (m) are increased and the system stops by catching the TV signal, but a pulse of i=+B is applied on each occasion to obtain the station search operation. When the tuning voltage (m) reaches the maximum UHF, the station search operation is stopped, and setting of l, m=minimum and band=VHF-LOW is made. Thus, the (i) changes to L. In this case, since the inputs (j) and (i) of the circuit Q go to H and L respectively, a transistor 41 turns on and the state of i=L is obtained, then AFT information (d) and (e) go to H. When a station search trigger is applied next, the station search is obtained from the turning voltage (m) from the minimum value. |
