| 摘要 |
PURPOSE:To elevate the quality of picture significantly without increasing the power source capacity by applying a voltage to any heating resistor with the resistance value higher than the required value to lower the resistance value. CONSTITUTION:A group of heating resistors 4 are formed on an insulating substrate 1 as electrically connected to ridge electrodes 2a of a common electrode 2 and individual electrodes 31-3n. Portions between adjacent ridge electrodes 2a constitute heating resistors 4a of 1 bit respectively and the resistance value of heating resistors 4a are lowered by applying a pulse voltage when higher than the required value. This can hold back variations in the resistance values of the heating resistors at the level the same or less than that of the thin film type thermal head thereby improving the quality of picture without increasing the power source capacity. |
