Abstract: The present invention uses a temperature sensor to sense the temperature of a print head configured to eject ink, and senses the environmental temperature of a printing apparatus. The temperature of the print head is corrected based on the environmental temperature only if information from the temperature sensor is different from the last information acquired.

Abstract: There are provided an inkjet printing apparatus and an inkjet printing method, whereby, the temperature of a print head is controlled and the ejection volume of ink to be ejected is stabilized to print a high-quality image, even at a high printing duty. Based on print data, an ejection number of ink to be ejected into a unit printing area is counted. The print head is heated to a target temperature that is raised in consonance with an increase in the count value.

Abstract: An ink jet printing apparatus and a print head recovery method are provided which effectively execute a preliminary ejection to eject ink not contributing to image printing from nozzle opening of the print head to maintain the ink ejection performance in good condition. The ink in the print head is heated to a first temperature, at which a first preliminary ejection is executed. Then, when the ink temperature falls to a second temperature, which is lower than the first temperature, a second preliminary ejection is executed.

Abstract: The present invention provides a liquid ejection head which includes a plurality of ejection ports 302 arranged so as to form an ejection port row and which, after a recovery process of expanding and transferring a bubble toward an ink supply port, allows the bubble to be smoothly removed from a nozzle 310. electrothermal transducing element A plurality of nozzle filters 306 are arranged between an ink supply port and the ink channel 304 so that ink supplied to the bubbling chamber 303 through the ink supply port is passed between the nozzle filters 306 to separate impurities contained in the ink, from the ink. When a distance between an ink channel inlet 311 and the nozzle filter 306 is defined as L1 and a distance between the adjacent nozzle filters 306 is defined as L2, a relationship between L1 and L2 satisfies L1?L2.

Abstract: When paper dirt that could not be removed completely by the wiping gets trapped in the recessed portions formed in the ejection port face, the paper dirt may interfere with ejection ports, giving rise to a possibility of image impairments. To deal with this problem, the ejection ports and the recessed portions in the print head are shifted from each other so that their positions are not aligned in the wiping direction.

Abstract: The order of the arrangement of ejection opening arrays of two types of ink overlapping in reciprocating scan is decided as follows. An ejection order is decided so that the case where the fixing areas of a main droplet and a satellite are different (dot area is increased) in the forward and backward scan first occurs. By this configuration, the area of the dot and the portion in which different colors are generated due to the difference in the overlapping order in the reciprocating scan can be reduced, compared with the case where the arrangement order is opposite to the above-described case. As a result, a difference in color between areas for which printing is completed by the reciprocating scanning is reduced and thus color unevenness of a printed image can be reduced.

Abstract: When completing an image in a predetermined area by an odd or even number of bidirectional printing scans, this invention makes it possible to suppress lines of image defects and density variations and thereby print a high-quality image at high speed. In completing an image by an odd number of bidirectional printing scans, the print data for small ink droplets and large ink droplets are thinned using the first and second thinning pattern. The first and second thinning pattern thin the print data for small ink droplets and large ink droplets so that a difference between the total print ratio of all forward printing scans of the odd number of scans and the total print ratio of all backward printing scans of the odd number of scans when the first thinning pattern is used differs from that when the second thinning pattern is used.