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AssigneeCanon Kabushiki Kaisha
InventorsMinoru Teshigawara, Naoji Otsuka, Kiichiro Takahashi, Osamu Iwasaki
Estimating the term…
A print apparatus that, without significantly reducing an overall printing speed, allows a reduction in uneven densities due to the discharge time difference between black ink and color inks, which occur particularly at both ends in a scanning range and which are caused by the printing by bidirectional scanning of print heads, and enables high image-quality printing to be realized. In this print apparatus, one band is divided into plural areas in a main scanning direction, the dot numbers of black ink and color ink imparted to respective areas are counted. If there are any areas where the dot numbers of both black and color exceed respective threshold values, the area number is counted, and if the number exceeds a predetermined number, the print mode is switched from bidirectional printing to a unidirectional one, upon determining that there is a high probability of occurrence of the above-described uneven densities.
An ink jet print apparatus capable of printing in a bidirectional printing mode wherein printing is performed on a print medium by both a main scan in an advance direction and a main scan in a return direction of print heads for discharging a plurality of different kinds of inks, and capable of printing in a unidirectional printing mode wherein printing is performed on the print medium by either the main scan in the advance direction or the main scan in the return direction of the print heads, the apparatus comprising:
An ink jet printing method wherein printing is performed in any one of a bidirectional printing mode in which printing is performed on a print medium by both a main scan in an advance direction and a main scan in a return direction of print heads for discharging a plurality of different kinds of inks, and a unidirectional printing mode in high printing is performed on the print medium by either the main scan in the advance direction or that in the return direction of the print heads, the method comprising the steps of:
A control program for controlling an ink jet print apparatus that performs printing on a print medium using print heads for discharging a plurality of different kinds of inks, the program comprising the steps of:
An ink jet printing method wherein printing is performed in any one of a bidirectional printing mode in which printing is performed on a print medium by both a main scan in an advance direction and a main scan in a return direction of print heads for discharging a plurality of different kinds of inks, and a unidirectional printing mode in which printing is performed on the print medium by one of the main scan in the advance direction and the main scan in the return direction of the print heads, the method comprising the steps of:
Dependencies are inferred from the claim text.
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From the US filing history. Foreign family members aren’t listed.
With means for effecting line or character spacing in either direction: with a reciprocating print head printing in both directions across the…
Typewriters
Term ended 24 Apr 2022 (estimated)
1. Field of the Invention
The present invention relates to an ink jet print apparatus, and an ink jet printing method. More particularly, the present invention relates to an ink jet print apparatus, an ink jet printing method, program controlling the apparatus, and a storage medium storing the program that allow a reduction in uneven colors due to the difference in recording time between recording black inks and color inks, the time difference being caused by performing printing by bidirectional scanning of recording heads.
2. Description of the Related Art
FIG. 1 is a schematic perspective view showing the configuration of the main section of an ink jet printer according to a first embodiment of the present invention.
FIG. 2 is a schematic block diagram showing the configuration of the control circuit of the ink jet printer in FIG. 1.
FIG. 3 is a schematic view illustrating, for each ink, the surface of a discharge port in the print head of the head cartridge used for the printer shown in FIG. 1.
In the embodiments according to the present invention, when attempting to perform a bidirectional printing using a recording head having a configuration where columns of nozzles that discharge black ink with a low permeability along, for example, a subsidiary scanning direction, and columns of nozzles that discharge color inks with a permeability different from that of black ink, i.e., super-permeability, are arranged in a longitudinal arrangement, printing is performed by dividing print data for each band into a plurality of regions, acquiring respective imparting amounts of a black ink and color inks for each region, determining whether the respective imparting amounts exceed respective predetermined values, and if so, switching printing from bidirectional printing to a unidirectional one.
With these arrangements, when uneven color due to a time difference is liable to occur, the uneven color can be reduced by unidirectional printing. Meanwhile, when the uneven color does not so occur, for example, when a text including color letters is to be printed, a reduction in the recording speed can be minimized since bidirectional printing is performed. Thus, the present invention is capable of suppressing a reduction in the recording speed to a necessary minimum while inhibiting an occurrence of uneven color caused by a time difference between black and colors.
Hereinafter, embodiments according to the present invention will be described with reference to the accompanying drawings.