| 摘要 |
<p>PROBLEM TO BE SOLVED: To reduce a thermal stress on heaters of a thermal head, to prolong thereby the life of the heaters, to form an intended stable state of perforation in a master and to reduce a power loss in heating of the heaters, by lowering a peak temperature of heating of the heaters to a necessary minimum on the occasion when the master is made into a plate by using the thermal head. SOLUTION: In a thermal plate making apparatus wherein a thermal head 1 having a plurality of heaters 2 is brought into contact with a master 3 having a film, the master 3 being moved in a sub-scanning direction F with a prescribed sub-scanning feed pitch pf and the film of the master 3 being perforated by melting by position-selective heating of the heaters 2 according to image data, a width tp of an energization pulse for making the heaters 2 heat, a printing period t1 of the thermal head 1 and the sub-scanning feed pitch pf satisfy the relation of [energization pulse width tp (μs)÷printing period t1 (μs/line)]×sub-scanning feed pitch pf (μm/line)<=25 (μm). Besides, a control device for varying the number of divisions of printing is provided.</p> |
