| 摘要 |
PURPOSE:To prolong the life of each heating element and to improve a printing quality, by providing a resistance element for setting voltage which has the same resistance value as the heating element. CONSTITUTION:Heating elements 21-2N corresponding to the number of dots are embedded in a head substrate 1, and one end of each heating element 21-2N is connected to a common terminal CO of a connector 8 through the intermediary of a flexible member 7, while the other end thereof is connected to a driving circuit 4. Each signal input terminal of the driving circuit 4 corresponding to each heating element 21-2N is connected to each signal terminal 51-5N of the connector 8, while a common terminal of the driving circuit 4 is connected to a terminal CE of the connector 8. Moreover, a resistance element 9 for setting voltage, which is formed of the same material and has the same shape as each heating element, is embedded in the head substrate 1. The opposite ends of this resistance element 9 are connected to terminals CR and CS of the connector 8 through the flexible member 7, respectively. Accordingly, the resistance value of the resistance element 9 is equal to the resistance value of each heating element. When a thermal head thus constructed is connected to a head voltage supply circuit, the resistance element 9 for setting voltage is connected also to the head voltage supply circuit, and the head voltage supply circuit impresses on each heating element 21-2N a head voltage corresponding to an input resistance value. |
