Incremental printing of symbolic information – Ink jet – Ejector mechanism
Reexamination Certificate
1998-07-27
2001-11-06
Barlow, John (Department: 2853)
Incremental printing of symbolic information
Ink jet
Ejector mechanism
C347S033000, C347S022000
Reexamination Certificate
active
06312094
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to an ink-jet printer which prints an image onto a print medium held on a rotary drum with ink ejected from a print head, and more particularly, to an ink-jet printer whose print head is constituted by a plurality of ink-jet nozzles disposed in the axial direction of the rotary drum.
The popularity of serial-type ink-jet printers is spreading. In the serial-type ink-jet printer, a print head and an ink cassette of a relatively small capacity are integrally mounted on a carriage, and the carriage is movably attached to a guide bar extending across a paper sheet. The paper sheet is fed in a direction perpendicular to the guide bar at a constant pitch, and the carriage is moved along the-guide bar each time the paper sheet is fed for one pitch. The print head ejects ink during the movement of the carriage. In the case where the printer is used for color printing, the print head includes a plurality of ink-jet nozzles which are respectively supplied with inks of different colors from ink tanks. In the structure as described above, for example, a color image of A
4
size is printed out in about ten minutes. Thus, the serial-type ink-jet printer operates at a slow print speed of 0.1 sheet per minute.
In recent years, a drum rotation type ink-jet printer has been developed to perform color printing at a higher speed. In this ink-jet printer, a paper sheet is held on a rotary drum rotating in one direction, and a print head includes a plurality of nozzle units which are arranged along the peripheral surface of the rotary drum and eject inks of different colors onto a paper sheet rotating together with the rotary drum. Each nozzle unit includes a plurality of ink-jet nozzles disposed across the paper sheet in the axial direction of the rotary drum. The pitch of the ink-jet nozzles is set to a value equal to a desired resolution or a value two to four times greater than the resolution. The print head is positioned such that the end surfaces of the ink-jet nozzles are close to the paper sheet on the rotary drum. The print head is set to a predetermined position in the case where the pitch of the ink-jet nozzles is equal to the desired resolution. The print head is set to be movable in the axial direction of the rotary drum from the predetermined position in the case where the pitch of the ink-jet nozzles exceeds the desired resolution. When the print head is movable in the axial direction of the rotary drum, the print head is moved at a rate corresponding to the desired resolution, for each revolution of the rotary drum, and is returned to the predetermined position after the print head is moved for a distance equal to the pitch of the ink-jet nozzles. The rotation speed of the rotary drum is set to 120 rpm. In this structure, for example, a color image of A
4
size can be printed out in about two or three seconds. Also, since the print head is not moved by a distance exceeding the nozzle pitch in the axial direction of the rotary drum, the number of prints to be obtained for each ink charge can be increased by placing ink cassettes of a large-capacity at a position remote from the print head and supplying inks of different colors to the respective nozzle units of the print head.
In this ink-jet printer, maintenance is carried out to prevent clogging of the nozzles and to drive out bubbles by spitting ink from the ink-jet nozzles at the non-printing time. Further, if paper particles are scattered from a paper sheet rotating together with the rotary drum at a high speed and adhere to the end surfaces of the nozzles, the paper particles soak up ink supplied to the nozzles. In the case where several thousands of sheets are printed in one day, such paper particles containing ink will likely drop on a paper sheet and arise a serious problem of degrading the print quality. Therefore, ink is also used for cleaning which removes the paper particles from the end surfaces of the ink-jet nozzles at the non-printing time or at the time when printing is interrupted.
In the ink-jet printer, therefore, ink once used maintenance as described above must be collected as waste ink. When the ink-jet printer is made compact, it is, however, difficult securely collect waste ink without smudging the neighboring components equipped in the ink-jet printer.
BRIEF SUMMARY OF THE INVENTION
An object of the present invention is to provide an ink-jet printer capable of collecting waste ink easily and securely without smudging the neighboring components equipped therein.
According to the present invention, there is provided an ink-jet printer comprising: a rotary drum for holding a print medium; a print head for printing an image by ejecting ink onto the print medium held on the rotary drum; an ink receiving unit facing the print head at a non-printing time to receive ink ejected from the print head; and an ink collecting section for collecting ink from the ink receiving unit, wherein the ink collecting section includes a blade member for wiping out ink which is remaining on the ink receiving unit without being collected after ejection of ink.
In the ink-jet printer, the blade member is capable of efficiently remove ink ejected from the print head at the non-printing time and remaining on the ink receiving unit without being collected. Therefore, it is possible to prevent ink from splashing to neighboring components around the ink receiving unit when the ink receiving unit is moved aside in preparation for printing. That is, waste ink can be collected easily and securely without smudging the neighboring components.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.
REFERENCES:
patent: 5266975 (1993-11-01), Mochizuki et al.
patent: 5517222 (1996-05-01), Sugiyama et al.
patent: 5555461 (1996-09-01), Ackerman
patent: 5997128 (1999-12-01), Lou et al.
patent: 6000775 (1999-12-01), Muraki
patent: 6050683 (2000-04-01), Nuita et al.
patent: 6-270420 (1994-09-01), None
Fujii Shinichiro
Ito Takuro
Kouzu Norio
Suzuki Yasuhiro
Barlow John
Do An H.
Frishauf, Holtz Goodman, Langer & Chick, P.C.
Toshiba Tec Kabushiki Kaisha
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