| 摘要 |
<p>PURPOSE:To protect heating elements from breakdown, by constituting such that a drive transistor is controlled by means of an output signal from an AND gate which receives a strobe signal and an inverted signal of an output from a delay circuit which receives said strobe signal. CONSTITUTION:A signal inputted from a strobe signal terminal 9 is split into two, one of which is inputted to a NAND gate 10 and the other is inputted to a delay circuit 11. The strobe signal inputted to the delay circuit 11 is outputted with a delay (td) caused by a timing signal. The delayed strobe signal is inverted by an inverter 13 and provided as another input to the NAND gate 10 to produce an ANDed strobe signal. When the delay time (td) is set within an allowable range of heating elements, the power supply time of the heating elements does not exceed said delay time (td) even for a wider pulse width of inputted strobe signal. Consequently, the heating elements can be protected from burning.</p> |
