| 摘要 |
PURPOSE:To eliminate variation of dot diameters by a method wherein binary printing is performed in a pulse width region where ink discharge quantity to an applied voltage to an electricity-heat transducer is drastically changed, and continuous-tone printing is performed in a pulse width region where the ink discharge quantity to the applied voltage to the an electricity-heat transducer is gradually changed. CONSTITUTION:Digital signals which are given to a picture signal input terminal 7 are converted to voltages in response to picture densities at an A-D converter 4, and given to a heater 1 to become driving voltage. In the meantime, to a picture, character selective signal input terminal 8, a selective signal which is selected by a user or a selective signals to be a picture or character is input. In the case of picture, a pulse generating circuit 5 is selected, and in the case of characters, a pulse generating circuit 6 is selected. The pulse generating circuit 5 or 6 sends out pulse signals while synchronizing with a clock. By doing this, in the case of printing characters, printing can be performed always by a uniform density without receiving variation of the voltage, and in the case of picture, tone expression in a wide range can be performed. |
