Incremental printing of symbolic information – Ink jet – Controller
Reexamination Certificate
2001-10-01
2004-05-25
Meier, Stephen D. (Department: 2853)
Incremental printing of symbolic information
Ink jet
Controller
C400S055000, C400S059000
Reexamination Certificate
active
06739683
ABSTRACT:
The present patent application claims priority from Japanese patent applications Nos. 2000-306632 filed on Oct. 2, 2000, 2000-306638 filed on Oct. 2, 2000, 2000-327013 filed on Oct. 20, 2000, 2001-266045 filed on Sep. 3, 2001, 2001-266046 filed on Sep. 3, 2001, 2001-299469 filed on Sep. 28, 2001, the contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an ink jet recording apparatus that ejects ink droplets from a recording head toward a recording medium that is being fed by paper-feeding rollers and following rollers while being held between the rollers.
Further, the present invention relates to an ink jet recording apparatus, in particular, to an inkjet printer capable of performing both unidirectional printing and bidirectional printing.
2. Description of the Related Art
An ink jet printer, that is one of an ink jet recording apparatus, generally supplies a recording medium such as paper via an auto-sheet feeder (automatic successive sheet-feeding mechanism) or manually via a paper feed-in openings, and then feed the recording medium into a gap between a paper-feeding roller and a following roller. While the paper is transported by rotating the paper-feeding roller, a pressure is applied to ink in a pressure-generating chamber of a recording (printing) head so as to eject ink droplets toward the paper, thereby information is printed onto the paper.
The above ink jet printer can normally perform printing on both plain paper and thick paper. In order to keep a printing quality high and substantially constant, a distance defined between a paper surface and a plane on which nozzle openings are arranged, i.e., a paper gap, is required to be always kept approximately constant by moving and adjusting the print head by means of a moving means for the print head.
The plain paper has a thickness of about 0.6 mm or less, containing the variation, for example. In this case, the print head is controlled to move to adjust the paper gap to realize about 1.2 mm. On the other hand, the thick paper has a thickness of about 0.7 mm to 1.5 mm containing the thickness variation. Thus, a position of the print head for the thick paper is moved upward from the position for the plain paper by about 0.9 mm.
Moreover, a serial non-impact type ink jet printer, for example, can select either unidirectional printing or bidirectional printing in a case of printing black-and-white text data such as characters, numerical characters and pieces of ruled lines. In the unidirectional printing, printing is performed in a predetermined one of two directions contained in a main scanning direction (i.e., a horizontal direction). This printing may be called as a high-quality printing mode. On the other hand, in the bidirectional printing, printing is performed both in a direction from left to right and a direction from right to left that correspond to the two directions contained in the main scanning direction. Such a printing may be called as a high-speed printing mode.
In the unidirectional printing, the printing is always performed in a predetermined direction. Thus, a path of the printing, that is, the moving amount of the print head, increases, thereby increasing a time required for the printing. In the unidirectional printing, however, effects of shift of printing positions caused by a mechanical accuracy of the print head or the like are extremely small. Therefore, high-quality printing can be achieved. On the other hand, in the bidirectional printing, the printing is performed from both ends in the horizontal direction. Thus, the printing path is reduced to a half of that of the unidirectional printing, thereby shortening the printing time. The bidirectional printing, however, is largely influenced by the printing position shifts. Therefore, in a case of printing what is composed of printing dots connected in a vertical direction (sub-scanning direction), such as a character of a double height size and a ruled line running in the vertical direction, discontinuity of the printing dots may be visualized, thereby degrading the printing quality. Thus, the user can select one of the unidirectional printing and the bidirectional printing for each printing job, i.e., each document, considering a type of the document to be printed.
In addition, the document to be printed may include a part of full-size characters and the like for which the bidirectional printing can be performed, and another part of the double-height-size characters, the vertical ruled lines and the like, which is to be printed by the unidirectional printing. Thus, in the case of selecting one of the unidirectional printing and the bidirectional printing for each printing job, the increase of the unnecessary printing path increases the printing time, or the printing quality is degraded in some parts of the document. Therefore, printing manners have been proposed in which expanded image data is analyzed in order to determine, depending on the contents of the image data, which one of the unidirectional printing and the bidirectional printing is to be performed (Post-examined Japanese Patent Publication No. 4-9153 and Unexamined Japanese Patent Applications (OPI) Nos. 2-233275 and 8-11353, for example)
Moreover, an information recordable disk in which information can be personally recorded, such as a CD-R, CD-RW, DVD-RAM or the like, has been becoming popular in recent years. Also, demands for personally printing a label on the printed disk have been increased. In this case, the label on the information recordable disk can be printed by supplying the information recordable disk with a tray made of extra-thick paper to the ink jet printer. Further, the performances of the ink jet printers have been enhanced in recent years, so that some ink jet printers can perform a high accuracy full-color printing not only on plain paper and special-purpose paper but also on various types of thick paper.
The conventional ink jet printer is designed, based on the assumption that the maximum thickness of paper handled by the ink jet printer is that of the thick paper, in such a manner that the thick paper manually fed in is allowed to press up against the following roller by its leading end and to be sandwiched between the paper-feeding roller and the following roller even if the following roller is pressed against the paper-feeding roller.
The extra-thick paper used for the tray for fixing the information recordable disk, however, has the thickness of about 1.6 mm to 2.5 mm. Thus, if the extra-thick paper is manually fed in and presses up against the following roller by its leading end, the pressing force F at the end of the extra-thick paper PPP works in a direction to rotate the following roller
1
, as shown in
FIG. 21
, failing to push up the following roller
1
. Therefore, it is difficult to clamp the extra-thick paper PPP between the paper-feeding roller
2
and the following roller
1
.
The above problems can be solved by providing a release member for the following roller in the ink jet printer, which urges the following roller against the paper-feeding roller after the following roller has been released from the paper-feeding roller and then the extra-thick paper has been manually inserted into a space between the paper-feeding roller and the following roller. In a conventional ink jet printer having such a release member, however, an operation lever for the moving means for the print head and an operation lever for the release member for the following roller are provided separately from each other. Thus, the mechanism becomes complicated and cannot be determined uniquely, and therefore the design of the mechanism also becomes complicated and the design error tends to occur.
Moreover, the thick paper has the thickness of about 0.7 mm to 1.5 mm, as described above. This means the thickness of the thick paper has variation of about 0.8 mm. Moreover, in a case of extra-thick paper for printing CD-R or the like, the thickness is in the range of about 1.6 mm to 2.5 mm. Thu
Asawa Hiroshi
Hashiuchi Koji
Ishihara Kenjiro
Isono Masahiro
Kobayashi Yo-ichi
Edwards & Angell LLP
Meier Stephen D.
Penny, Jr. John J.
Seiko Epson Corporation
Tran Ly T
LandOfFree
Ink-jet recording apparatus does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Ink-jet recording apparatus, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Ink-jet recording apparatus will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3185479