公开(公告)号：US20090237558A1

公开(公告)日：2009-09-24

申请号：US12307683

申请日：2008-05-14

申请人： Kazuya Miyashita ,  Keiichi Kuzumoto

发明人： Kazuya Miyashita ,  Keiichi Kuzumoto

IPC分类号： H04N7/00

CPC分类号： H04N7/035

摘要： A band-pass filter (131), which extracts a frequency component of a teletext reference signal from a digital input signal obtained by digitizing a composite signal, is provided in a frequency characteristic enhancement circuit (130). A determination circuit (145), which determines a state of the composite signal in accordance with maximum and minimum values of an output of the frequency characteristic enhancement circuit (130) during the period of the teletext reference signal and in accordance with maximum and minimum values of the output of the frequency characteristic enhancement circuit (130) during the period of time between a current horizontal synchronization interval and a next horizontal synchronization interval, is provided in a slicing circuit (140). A signal to be output to the slicing circuit (140) is generated by the frequency characteristic enhancement circuit (130) in accordance with either an output of the band-pass filter (131) or the digital input signal which is selected according to a determination result obtained by the determination circuit (145).

摘要翻译： 在频率特性增强电路（130）中提供了一种从通过数字化复合信号获得的数字输入信号中提取图文电视参考信号的频率分量的带通滤波器（131）。 一种确定电路（145），其根据图文电视参考信号期间的频率特性增强电路（130）的输出的最大值和最小值，并根据最大值和最小值确定复合信号的状态 在切片电路（140）中提供频率特性增强电路（130）在当前水平同步间隔和下一个水平同步间隔之间的时间段期间的输出。 根据频带特性增强电路（130）根据带通滤波器（131）的输出或根据确定的选择的数字输入信号产生要输出到限幅电路（140）的信号 由确定电路（145）获得的结果。