Ink-jet image forming method and device

Abstract

An ink-jet image forming method forms an image by forming dots using a fast-drying ink and a slow-drying ink, in which, when forming an image, an ambient temperature of an area where the image is formed is detected, and dot density of a predetermined area of the image is recognized based on image data. A process used to form dots is selected based on the detected ambient temperature and the recognized dot density. Under the condition where the inks are easily dried, the slow-drying ink is used to form dots, and under the condition where it is difficult to dry the inks, the slow-drying ink is used suitably with the fast-drying ink to form dots. As a result, the inks can be dried efficiently while suppressing deterioration of image quality.

Description

technical field [0001] The present invention relates to an inkjet image forming method and an inkjet image forming apparatus using both quick-drying ink and slow-drying ink. In particular, it relates to an inkjet image forming method and an inkjet image forming apparatus which keep the drying time of slow-drying ink, such as black ink, constant and at the same time use the slow-drying ink to improve color reproducibility to improve image quality. It also relates to improvements to prevent contamination caused by contact between recording sheets after image formation when images are sequentially formed on continuously fed recording sheets. Background technique [0002] In order to improve the image quality and shorten the drying time, studies have been made to improve the method of forming dots in an inkjet image forming apparatus (hereinafter simply referred to as "inkjet printer"). [0003] For example, U.S. Patent No. 5,596,355 (published January 21, 1997) discloses a tec...

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Problems solved by technology

[0013] On the other hand, in the case of forming a completely black area with quick-drying black ink, the reproducibility of black is poor, thus resulting in a decrease in image quality.

[0014] In addition to the above-mentioned problems, the technology disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 7-149036 and Japanese Patent Laid-Open No. 8-197831 also has the following problem: In the border area in the black dot area, the colored dots, i.e. yellow (Y ), magenta (M), and cyan (C) monochromatic mixture of three monochromatic colors, black image quality deterioration

That is, the technology is not aggressively shortening the drying time of the ink

[0026] In addition, the technology disclosed in the above-mentioned JP-A-11-5664 not only complicates the structure of the paper discharge stacker, but also requires a driving force to sequentially replace the recording paper between the paper discharge support plates, which increases the overall cost of the image forming apparatus. Power consumption

[0027] As described above, each of the above-mentioned prior arts has not yet been able to achieve "accumulation of subsequent printing after the ink on the previously discharged recording paper is completely dried without increasing the time required to form an image and without complicating the structure of the paper discharge part of the device." recording paper

[0028] Although it has also been proposed to install drying components such as heaters to promote ink drying, this not only makes the structure of the device complicated, but also increases the power consumed by the drying components, which is poor in practicability.

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