Incremental printing of symbolic information – Ink jet – Ejector mechanism
Reexamination Certificate
1998-02-17
2001-10-09
Le, N. (Department: 2861)
Incremental printing of symbolic information
Ink jet
Ejector mechanism
C347S040000, C347S015000
Reexamination Certificate
active
06299285
ABSTRACT:
This application is based on Patent Application No. 31878/1997 filed Feb. 17, 1997 in Japan, the content of which is incorporated hereinto by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to an ink-jet printing apparatus and an ink-jet printing method performing printing by ejecting ink on a printing medium. More specifically, the invention relates to an ink-jet printing apparatus and an ink-jet printing method performing printing using ink, a liquid which can make a coloring agent in the ink insoluble or coagulated, or a plurality of inks having different densities. It should be noted that the present invention is applicable of all devices using printing media, such as paper, cloth, a non-woven fabric, an OHP sheet and so on, and more particularly to a business machine, such as a printer, a copy machine, a facsimile machine and the like, and manufacturing industrial machines, such as a textile printing apparatus and so on, as applicable apparatus.
2. Description of the Prior Art
Conventionally, an ink-jet printing apparatus performing printing for a printing medium, such as paper, cloth, a plastic sheet, an OHP sheet or the like (hereinafter simply referred to as printing paper) has various advantages, such as the capability of high-density and high-speed printing, and so on, and is widely employed as output means of an information processing system, such as a copy machine, a facsimile machine, an electronic typewriter, a wordprocessor, a printer as an output terminal of workstation and the like, or a handy printer or a portable printer to be provided in a personal computer, a host computer, an optical disk device, a video apparatus and so on.
In this case, an ink-jet printing apparatus has a construction adapted to a function, a mode of use and so on specific to each of these devices, respectively. Typically, the ink-jet printing apparatus includes a carriage mounting a printing head as printing means and an ink tank, transporting means for transporting the printing paper, and control means for controlling these components. The printing head which ejects ink droplets through a plurality of ejection openings, is scanned with respect to a printing paper in a direction (primary scanning direction) perpendicular to a transporting direction (auxiliary scanning direction) to perform ink ejection while scanning in the primary scanning direction. Also, the printing paper is intermittently transported in an amount corresponding to a printing width between each two scannings. This construction, in which printing is performed by ejecting ink on the printing paper, has been widely used as a printing system with a low running cost and low noise associating with printing. Further, by employing a printing head in which a large number of ejection openings for ejecting ink are arranged in alignment in the auxiliary scanning direction and by scanning the printing head on the printing paper, printing in a width corresponding to the number of ejection openings can be performed. By this arrangement, speeding up of the printing operation can be achieved.
In addition, in recent years, depending upon demand for full-color printing, there has been practiced an apparatus which mounts printing heads for three or four color inks, and is capable of forming a full color image. Such an apparatus mounts three or four kinds of printing heads and ink tanks for three primary colors of yellow (Y), magenta (M) and cyan (C) or four colors including black (hereinafter occasionally referred to as Bk) in addition to three primary colors.
In color printing by the conventional ink-jet printing system, it is generally known that the goals of preventing bleeding of the ink, and increasing the density of a black image and preventing feathering are inconsistent with each other. Therefore, in the conventional apparatus, it has been difficult to sufficiently satisfy the user's needs for quality of a color printing image. It has been known that this has been caused for following reasons.
Normally, in the case of performing color printing on a plane paper by an ink-jet printing method, bleeding of the ink in a boundary of respective color regions forming an image can be prevented by using an ink having a relatively high penetration speed, thus having high fixing ability. However, when using ink having high penetration speed, it is often the case that the density of the black image portion becomes low, and color development ability in color image portions other than black also becomes low. Furthermore, upon printing of a line image, typically represented by character or the like, it is possible to cause penetration of ink along fibers of the paper, thereby causing so-called feathering. In particular, in comparison with the image printed by a color other than black, feathering in the character printed by black ink is easily perceived to make the character vague for lack of sharpness. As set forth, as a result of the attempt to prevent bleeding between respective colors of inks, the quality of the overall printed image can be significantly lowered.
In contrast to this, it can be considered that the high density or the like of the image is realized while preventing feathering, by ejecting a large amount of the ink having relatively low penetration ability to the plane of the paper. However, in such case, for example, in the portions located adjacent the boundary of the black image and the color image, bleeding of the black ink and the color inks can be caused, to significantly lower the quality of the printed image.
As one system providing a solution for the foregoing problem, a system is known in which a heater is provided in a printing apparatus to promote evaporation of the ink and can obtain a color image having high-color-developing ability with no bleeding between the colors. However, such system may cause the apparatus to be bulky and have a high cost.
In Japanese Patent Application Laid-open No. 146,355/1991, there has been proposed a system in which printing is not performed for respective regions along the boundary between regions of the black and the color. However, this method requires varying the data for printing and thus it may happen that the quality of the image to be actually printed is degraded.
Also, in Japanese Patent Application Laid-open No. 158,049/1992, there is proposed a method of printing, in which printing heads corresponding to a plurality of colors for color printing and a printing head for character printing are provided, and printing is performed by switching use of the printing head for the color image and the printing head for character printing. In this method, when the black image printed by the color printing head and the black image printed by the character printing head are present in an admixing manner, an uncomfortable feeling may be caused due to a difference between the respective printing quality of the two modes.
Furthermore, there has been considered a method of preventing bleeding between the black ink and the color inks at the boundary between the black image and other color image by overlaying color inks in a black region along the boundary between the black and color images. As set forth above, the black can be obtained by overlaying three colors, Y, M, C (admixing of the colors). However, the black image obtained by overlaying the color inks tends to have a lower color-development ability in comparison with the normal black ink.
On the other hand, in Japanese Patent Application Laid-open No. 084,992/1981 and Japanese Patent Application Laid-open No. 063,185/1989, a technology employing a liquid which makes a dye in the ink insoluble is disclosed.
Japanese Patent Application Laid-open No. 084,992/1981, discloses a method, in which a material for fixing the dye is preliminarily applied on the printing paper. However, this method requires a special printing paper. Also, in order to preliminarily apply the material for fixing the dye, it is inherent to increase the size and a cost of the apparatus. Furthermore, it is
Canon Kabushiki Kaisha
Fitzpatrick ,Cella, Harper & Scinto
Le N.
Nguyen Lamson
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