| 摘要 |
<p>PURPOSE:To enable the amount of programs to be reduced and prevent a head from being broken even on a runaway, by controlling a thermal head part by an output from a monostable multivibrator circuit which outputs a rectangular wave in accordance with an output signal from a microcomputer. CONSTITUTION:By causing the output O from the microcomputer 1 to be high (H), a motor for a thermal printer 4 is turned ON, and a dot timing signal is inputted to an input I. Simultaneously, output signals according to the images to be printed are outputted to P0-P6. Then, P0 is immediately dropped to a low (L) level irrespectively of a DOT signal. However, since the monostable multivibrator 2 outputs a rectangular wave having a preset pulse width after P0 becomes high (H), the driving circuit 3 can be operated for a predetermined period of time even if P0 is immediately made to be low (L). Accordingly, since the dot signal can be monitored by simply attaching importance to the program in the case of the rise and since some time delay does not matter in the case of the fall, the amount of the program can be reduced, and the head is not broken even at the time runaway of the microcomputer.</p> |
