Ink jet printing apparatus and ink jet printing method

An ink jet printing apparatus to form an image on a print medium by using a print head, wherein the print head has a plurality of print element columns, each composed of an array of print elements adapted to eject ink by applying a pulse to a heater, the ink jet printing apparatus comprising:

• first acquisition means for acquiring for each of the plurality of print element columns rank information representing the amount of heat transferred from the heater to the ink in unit time;
• second acquisition means for acquiring temperature information of the print head;
• a table to hold pulse information including width information and voltage information of the pulse corresponding to the temperature information and the rank information;
• selection means for selecting the pulse information from the table for each of the plurality of print element columns based on the rank information acquired by the first acquisition means and on the temperature information acquired by the second acquisition means;
• and
• drive means for driving the print elements based on the pulse information selected by the selection means;
• wherein the voltage information of the pulse is equal for particular temperature information regardless of the rank information and, in regions higher than a predetermined temperature, varies according to the temperature information.

An ink jet printing method to form an image on a print medium by using a print head, wherein the print head has a plurality of print element columns, each composed of an array of print elements adapted to eject ink by applying a pulse to a heater, the ink jet printing method comprising:

• a first acquisition step to acquire for each of the plurality of print element columns rank information representing the amount of heat transferred from the heater to the ink in unit time;
• a second acquisition step to acquire temperature information of the print head;
• a selection step to select a pulse information for each of the plurality of print element columns based on the rank information acquired by the first acquisition step and on the temperature information acquired by the second acquisition step;
• and
• a drive step to drive the print elements based on the pulse information selected by the selection step;
• wherein the pulse information includes width information and voltage information of the pulse;
• wherein the selection step selects the pulse information from a table that holds the pulse information by matching it with the temperature information and the rank information;
• wherein the voltage information of the pulse is equal for particular temperature information regardless of the rank information and, in regions higher than a predetermined temperature, varies according to the temperature information.