| 摘要 |
<p>A CRT display unit comprises a line mode detecting circuit for determining a standard mode or a high-resolution mode dependent on the output of a counter counting a horizontal synchronizing signal. When the high-resolution mode is determined, a switching circuit enables a horizontal oscillator and a horizontal deflecting circuit to operate corresponding to the highresolution mode. In other words, the switching circuit selects time constants so as to increase a horizontal oscillating frequency of the horizontal oscillator. To a collector of a horizontal deflecting transistor, two capacitors are connected so that a horizontal flyback period may be shortened. An end of a horizontal deflecting coil is connected to a step-down transformer so as to increase a horizontal amplitude. Thus, the horizontal oscillating frequency, the horizontal amplitude and the horizontal flyback period can be automatically set according to each mode.</p> |
