| 摘要 |
<p>PURPOSE:To secure reliability by suppressing a rise in the temps. of both of a substrate and a recording power supply, by reducing the driving number of heat generating resistors to one half of the number of the heat generating resistors in each group at the most when the temp. of the substrate and that of the recording power supply exceed a set value. CONSTITUTION:In a thermal recording system for successively performing printing at every group among many ones obtained by dividing a heat generating resistor 1 for thermal printing, temp. detection circuits 22, 23 detect the temp. of the substrate having the heat generating resistor 1 mounted thereon and the temp. of a recording power supply part 2. A black count circuit 16 counts the number of the black printing bits of the recording signal corresponding to one scanning to output the value thereof. A control means turns the recording signal 12 to white periodically when the temps. from the temp. detection circuits 22, 23 and the count value from the black count circuit 16 exceed preset values to drive each group of the heat generating resistor 1. Even when the recording high in a black ratio wherein a defect becoming max. in power consumption at the time of continuous black printing is removed is continued, a black printing ratio falls and the temps. of both of the substrate and the recording power supply part do not rise and the reliability of the resistor and recording power supply part is secured.</p> |
