公开(公告)号：US4594611A

公开(公告)日：1986-06-10

申请号：US594661

申请日：1984-03-29

申请人： Kiyoshi Sugibayashi ,  Tomihiro Oguchi ,  Hiroyuki Takahori

发明人： Kiyoshi Sugibayashi ,  Tomihiro Oguchi ,  Hiroyuki Takahori

IPC分类号： H03J7/20 ,  H03J1/00 ,  H03J7/02 ,  H03J7/18 ,  H04N5/50

CPC分类号： H03J1/0091

摘要： A method for tuning a television receiver in which an optimum local oscillator frequency is selected for offset stations. A local oscillator frequency of the receiver is incremented in steps of a first predetermined frequency interval beginning with a frequency at the bottom of an offset band around the center frequency of the local oscillator. As the local oscillator frequency is scanned, when both an up signal, indicative that the tuning frequency is above a predetermined range around the actual frequency of the received signal, and a down signal, indicative that the tuning frequency is below the predetermined range around the center frequency, the local oscillator is decremented by the first frequency interval and then incremented in a second, smaller frequency interval until the up and down signals are both lost. The local oscillator frequency is then increased and decreased by the first predetermined frequency interval, wherein, if both the up and down signals toggle states, the frequency at which both the up and down signals were lost when scanning with the second frequency interval is accepted as the best tuning frequency.

摘要翻译： 一种用于对电视接收机进行调谐的方法，其中为偏移站选择了最佳本地振荡器频率。 接收机的本地振荡器频率以从本地振荡器的中心频率附近的偏移频带的底部的频率开始的第一预定频率间隔的步长递增。 当本地振荡器频率被扫描时，当指示调谐频率高于接收信号的实际频率的预定范围的上升信号和下降信号时，指示调谐频率低于周围的预定范围 中心频率，本地振荡器减小第一个频率间隔，然后在第二个较小的频率间隔中递增，直到上下信号都丢失。 然后本地振荡器频率增加并减小第一预定频率间隔，其中，如果上下信号同时触发状态，则当以第二频率间隔进行扫描时上升和下降信号两者都丢失的频率被接受为 最佳调谐频率。