| 摘要 |
A television receiver having a video signal receiving circuit for receiving a video signal, a vertical synchronizing signal and a horizontal synchronizing signal, a signal processing circuit for supplying the video signal to a cathode ray tube, a vertical deflection circuit for supplying a vertical deflection signal to the cathode ray tube in response to the vertical synchronizing signal, a horizontal deflection circuit for supplying a horizontal deflection signal to the cathode ray tube in response to the horizontal synchronizing signal, a frequency detector circuit connected to the video signal receiving circuit for detecting the frequency of the horizontal synchronizing signal and deriving a control signal in response thereto and a control circuit connected between the frequency detector circuit and the horizontal deflection circuit for controlling the latter in response to the control signal from the former. In this case, the horizontal deflection circuit includes a circuit for changing the duty cycle of a horizontal drive pulse such that the duty cycle increases when the horizontal frequency becomes higher. |
