PURPOSE: To ensure easy selection of an ink and enable high-speed recording, by providing a liquid coloring agent having a volume resistivity not less than a specified value and making direct contact with heat generating resistors or lead electrodes.
CONSTITUTION: The volume resistivity of a liquid coloring agent disposed to make direct contact with heat generating resistors or lead electrodes is selected to be not less than 106Ω.cm. If the volume resistivity of the ink is not more than 105Ω.cm, the phenomenon in which flying of the ink is not achieved may often occur. This is because of leakage occurring between adjacent ones of the electrodes 18 due to the ink, which results in that the heat generating resistor 16 does not generate sufficient heat. When a liquid coloring agent having an electric resistance not less than a predetermined value is used, short-circuiting between the electrodes can be prevented from occurring, even when the coloring agent 13 makes direct contact with the heat generating resistors 16 arranged in an array or the lead electrodes 18. Accordingly, it is unnecessary to provide an insulating layer or the like on the lead electrodes, and the coloring agent 13 can be efficiently heated. In addition, since the speed of raising the temperature of the ink is enhanced, high-speed recording can be performed.
FUJIMURA YOSHIHIKO
INOUE NANAO
