| 摘要 |
PURPOSE:To reserve a recording energy and prevent the occurence of nonuniformity in recording by a method wherein a preheating pulse sufficiently narrower in the width thereof than that of a recording pulse is utilized to keep respective heating elements in heated conditions at all times due to the preheating pulse. CONSTITUTION:An all data switch driving circuit 8 receiving the preheating pulse from a control circuit 1 makes transistors P1-Pn in a data switch circuit 4 conductive and feeds electricity simultaneously to the heating elements H11-H1n...Hm1- Hmm. of a recording head 7 corresponding to the transistors Q1-Qm of a block switch circuit 6 which is conductive at that time, thereby preheating these heating elements each one time for each block during each recording period while a number of times corresponding to the length of time during each resting period of the recording. According to the system above-described, the ratio of the pulse width of the preheating pulse to the recording pulse may be set to about 0.1-0.3, therefore, the recording head 7 may be preheated sufficiently within a range wherein the head is not developing color by the preheating pulse. |
