| 摘要 |
PURPOSE:To maintain a constantly fixed printing quality, by electrically connecting an oscillating circuit part capable of oscillating at a frequency according to the ambient temperature and a counter in a controlling circuit part to each other. CONSTITUTION:An oscillating circuit part 5 constitutes a multivibrator-type oscillator, and an oscillational output therefrom is inputted to a controlling circuit part 4 through terminals T55, T45. An edge detector 43a of a counter 43 is first set for detecting the leading edge of the input. Next, the leading edge is detected, and then the value in a free-running counter 43b at that moment is stored into a memory Ta. The trailing edge of the input is detected, and the value in the counter 43b at that moment is stored into a memory Tb. The content of the memory Tb is subtracted from the content of the memory Ta, whereby the period of time T0 from the leading edge to the trailing edge of the input signal can be obtained. Based on the period of time T0, an oscillating frequency f=1/T0 is determined, and the ambient temperature can be obtained. |
