公开(公告)号：US06215258B1

公开(公告)日：2001-04-10

申请号：US09407923

申请日：1999-09-29

申请人： Tomohiro Sakata ,  Mitsuya Masuda ,  Yukio Uchida ,  Tomoaki Iwamoto

发明人： Tomohiro Sakata ,  Mitsuya Masuda ,  Yukio Uchida ,  Tomoaki Iwamoto

IPC分类号： G09G104

CPC分类号： H04N3/26 ,  H01J2229/4841

摘要： A dynamic focus circuit enables ideal focusing characteristics to be obtained across the entire screen of a wide-angled cathode ray tube, by generating a dynamic focus voltage having a flat-bottomed waveform through the addition of a simple circuit to a conventional analog circuit. If an S-shaping voltage method is used, the voltage of a signal induced in a secondary coil of a step-up transformer for raising the voltage of a parabolic waveform signal having a horizontal deflection period switches the gain for converting the parabolic waveform signal to a dynamic focus voltage, according to whether the induced voltage exceeds a specified reference value. If the induced voltage does not exceed the specified reference value, the parabolic waveform signal is converted to the dynamic focus voltage at a gain of less than one. If a DAF (Dynamic Focus) signal generating IC is used, a gain control voltage for controlling a gain of the parabolic waveform signal generated by the DAF signal generating IC is altered so that the gain is smaller than one at the approximate midpoint of a horizontal deflection period, and increases as it moves out to the edges of the screen.

摘要翻译： 动态聚焦电路通过通过向常规模拟电路添加简单电路而产生具有平底波形的动态聚焦电压，从而可以在广角阴极射线管的整个屏幕上获得理想的聚焦特性。 如果使用S整形电压方法，则升压变压器的次级线圈中感应的信号的电压用于提高具有水平偏转周期的抛物面波形信号的电压，将用于将抛物线波形信号转换的增益切换为 动态聚焦电压，根据感应电压是否超过规定的参考值。 如果感应电压不超过规定的参考值，则抛物线波形信号以小于1的增益转换为动态聚焦电压。 如果使用DAF（动态聚焦）信号发生IC，则改变用于控制由DAF信号产生IC产生的抛物线波形信号的增益的增益控制电压，使得增益小于在水平方向的大致中点处的增益 偏转周期，并且随着其移动到屏幕的边缘而增加。