Typewriting machines – Sheet or web – Including sheet guide
Reexamination Certificate
1998-01-06
2002-04-09
Hilten, John S. (Department: 2854)
Typewriting machines
Sheet or web
Including sheet guide
C400S625000
Reexamination Certificate
active
06367998
ABSTRACT:
CLAIM OF PRIORITY
This application makes reference to, incorporates the same herein, and claims all benefits accruing under 35 U.S.C. §119 from my application entitled Ink-Jet Printer With Function of Preventing Jamming Caused by Paper Warping filed with the Korean Industrial Property office on Jan. 6, 1997 and there duly assigned Ser. No. 97-00105 by that Office.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to printers and, more particularly, to a device for preventing the jamming of printed sheets of paper that become curled during conveyance.
2. Discussion of Related Art
A typical ink-jet printer is generally includes a paper feeding device for supplying paper in sheets, a conveying device for conveying the supplied paper from the paper feeding device, a printing device for performing a print operation on the conveyed paper, and a discharging device for discharging printed paper.
FIG. 1
shows the internal construction of such a printer.
In
FIG. 1
, sheets of paper
1
are seated on a paper feeding device
10
and individually fed through a conveying device
20
by a plurality of feed rollers
21
and friction rollers
22
. A printing device
30
is provided with a pulley
32
driven by a motor
31
via a timing belt
33
, which laterally transfers a carriage
34
that carries of print heads
35
. Line-by line printing is performed as the heads
35
move left and right across the paper that is gradually conveyed over a base frame
40
toward a discharging device
50
. The base frame
40
acts as a support plate for printing in opposition to the reciprocating print heads
35
. When the paper bearing formed images arrives at the discharging device
50
, it is discharged between a plurality of discharging rollers
52
, being rotated by force transmission rollers
51
that are in contact with the feed rollers
21
, and a plurality of star wheels
53
(shown in FIG.
2
). A cover door
60
is installed on the ink-jet printer.
Accordingly, the paper path consists of the paper feeding device, the conveying and printing device, and the discharging device. It should be appreciated that, in such an ink-jet printer, the leading edge of the paper being carried from the conveying device to the discharging device is not constrained and is thus free to curl or become distorted in shape (flatness). This is especially true of in dry environment conditions.
As shown in
FIG. 2
, as the curled sheet of paper
1
moves over the base frame
40
without means for constraint, the leading edge thereof cannot be smoothly inserted between the star wheel
53
and discharging roller
52
and thus escapes from the conveyance path, resulting in a paper jam. Though this problem is particularly exacerbating in a dry environment, any similar warping curling of the printing paper, either before or during printing, tends to cause similar paper jamming conditions.
SUMMARY OF THE INVENTION
Therefore, in order to overcome such drawbacks of the prior art, an objective of the present invention is to provide a device which prevents paper jamming, even if the leading edge of a conveyed sheet of paper printed is curled.
It is another objective of the present invention to provide an ink-jet printer whose structure provides for paper jamming prevention means without undue increases in product costs.
To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described, there is provided a paper jamming prevention device having: a conveying portion for conveying a sheet of paper from a paper feeding portion according to a feed command; a discharging portion for receiving the conveyed sheet of paper for discharge; and a base frame, installed between the conveying portion and the discharging portion, having a flat surface disposed toward the conveying portion. The conveying portion located toward the discharging portion, is curved and induces the paper to sag.
In the preferred embodiment of the present invention, the base frame over which printed paper is conveyed has a curved conveyance surface, excluding a printing surface of which must be flat, along which discharging means are disposed. As a printed sheet of paper passes through the curved conveyance surface of the base frame, it is inherently contoured such that the cross-section of the paper's middle region is depressed. Therefore, even with an upward warping force, the leading edge of the paper retains its directness of forward orientation and does not curl upward, due to the inherent rigidity maintained by the sagging of the middle region thereof.
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patent: 5725319 (1998-03-01), Saito et al.
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patent: 5888001 (1999-03-01), Sheng
Bushnell , Esq. Robert E.
Cone Darius N.
Hilten John S.
Samsung Electronics Co,. Ltd.
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