| 摘要 |
PURPOSE:To permit multilevel recording of high accuracy by a method in which during the cooling period after application of recording signals, the heating elements of a thermal head are selected in order, current is supplied for a short period of time to obtain the resistance values of the heating elements, and on the basis of the resistance values, the recording signals are controlled. CONSTITUTION:By a controller 3, according to resistance information obtained in a resistance arithmetical unit 5 and also correspondingly to tonal data Dn, recording control signal PC is applied to a driver 2. Also, during the cooling period after application of recording signals to heating elements 1, the elements 1 are selected in order and control signal MC for supplying current for a short period of time is sent out. By the driver 2, according to the control signal MC, current is supplied to the selected elements 1 in such a short time that recording is impossible, and the current value is measured in a current measurer 4. Resistance value is calculated from the current value in a resistance arithmetic unit 5, and when the resistance value is out of a given range, alarm signal AL is sent out. Also, on the basis of the information of calculated resistance value given to the controller 3, the pulse width of recording signal corresponding to the following tonal data Dn can be corrected in the controller 3, permitting recording of high accuracy to be performed. |
