| 摘要 |
<p>PURPOSE:To reduce the number of connections of heating resistors and drive circuits by half by mounting a common earth line, a first current supply line connecting the respective one terminals of the even number-th heating resistors, a second current supply line connecting the respective one terminals of the odd number-th heating resistors and a switching element for applying DC voltage between the common earth line and the first or second current supply line. CONSTITUTION:When a drive signal is inputted to transistors T1-T512, the heating resistors corresponding to said transistors among the even number-th heating resistors R2-R1024 generate heat by a current Ia to reach predetermined temp. or higher and develop respective colors on recording paper. When a signal V2 is applied to a transistor Q2, the voltage 24V of a power supply 6 is supplied to the second current supply line and some of the odd number-th heating resistors R1-R1023 generate heat corresponding to transistors T1-T512 as mentioned above to develop colors on the recording paper. Therefore, it becomes possible to supply a color forming current only to the arbitrary heating resistors corresponding to drive signals S1-S512 and, since the heating resistors are connected to a drive IC 7 so as to constitute one set of two heating resistors, the number of connections of the heating resistors are reduced by half and a thermal head preparing process is simplified and the number of processes are reduced.</p> |
