PLATEAU A PAPIER POUR IMPRIMANTE A REPETITION

TRAY OF DISCHARGED PAPER FOR RECORDING APPARATUS

Abrégé anglais

ABSTRACT
The tray for discharged paper is utilized in a recording apparatus for
carrying out repeat-printing while reciprocating a paper being printed. A pair
of guide bars are provided to support and guide the edges of a paper sheet
along its back surface so as to prevent the paper sheet being repeat-printed
from coming into face-to-face contact with an upper receiving face of the tray
or with a top surface of another printed paper sheet which has already been
printed and stacked on the upper receiving face of the tray, thereby avoiding
adhesion of the paper being printed to the stacked paper sheet due to static
electricity. This construction can effectively suppress concurrent rolling of
the already printed paper sheet to a discharge roller when returning a paper
sheet being repeat-printed, and suppress generation of paper jams.
PAT 15890-1

Revendications

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE PROPERTY OR PRIVILEGE
IS CLAIMED ARE DEFINED AS FOLLOWS:
1. In a recording apparatus for carrying out repeat-printing while
reciprocating a paper sheet being printed, the improvement comprising:
a tray for receiving a discharged paper sheet; and
a pair of guide bars disposed on the tray in spaced relation from one
another in a widthwise direction of the tray for guiding and supporting
opposite edges of the paper sheet during the course of reciprocating movement
of the paper sheet in repeat-printing.
2. A recording apparatus according to claim 1, wherein the tray has a
plurality of support holes which can be selected to support the pair of guide
bars a given distance apart corresponding to the width of a paper sheet to be
repeat-printed.
PAT 15890-1

Description

~2~t ~
The present invention relates to an improvement in a tray for paper
discharged from a recording apparatus or the type which carries out repeat-
printing while reciprocating 8 paper sheet on which printing is being
recorded.
Conventionally, there has been generally utilized a diQcharge paper
tray having only a receiving face without any guide bar. However, with a
conventional discharged paper tray, when a printed paper sheet is partly
- and temporarily discharged from the apparatus during the repeat-printing
operation, it comes into face-to-face contact with the previously printed
paper sheet which has been already discharged onto the tray. Therefore,
interfacial adhesion results due to static electricity to thereby
frequently generate a paper ~am such that, when returning into the
apparatus the printed p~per sheet during the course of the repeat-printing
operation, the precedingly printed paper sheet is concurrently rolled into
the discharge roller unit together with the returning paper sheet.
` SUMMARY OF THE INVENTION
''
- The present invention provides a pair of spaced apart guide bars on a
~ .
discharge paper tray and normally located along the edges of a printed
paper sheet so as to avoid having a printed paper sheet being subjected to
a printing operation from coming into full face-to-face contact with a
previously printed paper sheet stored on the tray. Consequently,
electrostatic adhesion can be prevented between the paper sheet being
printed on repeat-printing and the precedingly printed paper sheet to
eliminate rolling in of the precedingly printed paper sheet when returning
the recording paper sheet during the course of the printing operation,
thereby preventing generation of any paper jams. Namely, by avoiding face-
to-face contact between printed paper sheets, electrostatic adhesion can be
prevented between the paper sheets so as to suppress paper ~ams.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a perspective view of a discharge paper tray in accordance
with a preferred embodiment according to the present invention;
Fig. 2 is a front view of the embodiment of Fig. 1: and
PAT 15890-1
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~2~
Fig~ 3 is a side view of the embodiment of Fig. 1 showing the
discharge paper tray set in a recording apparatus.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENT
Hereinafter, an embodiment of the present invention will be described
in conjunction with the drawings. Fig. 3 shows the state in which a
discharge paper tray 1 is set in a recording apparatus 5. Referring to the
figureQ, a recording paper sheet 6 is sandwiched by a discharge roller 4
and a pinch roller 8 within the recording apparatus 5. The rotational
direction of the discharge roller 4 is switched to effect reciprocating
movement of the paper sheet being printed. The switching of rotational
direction of the discharge roller 4 is controlled by a sequence controller
(not shown) provided within the recording apparatus 5 according to the
operating stage of the repeat-printing process being applied to the paper
sheet being printed.
During the course of repeat printing, the back face of the paper sheet
6 being printed is supported at its opposite edges A by a pair of guide
bars 2, while a central part B of the sheet makes no contact or slight
contact with a pre~iously printed paper sheet 7. In this state, the paper
sheet 6 is fed in discharge direction C while a rear part of the sheet is
held in the recording apparatus 5. When returning the sheet into the
apparatus, the discharge roller 4 is switched to rotate in the clockwise
direction~ Since face-to-face contact is substantially suppressed between
the currently processed sheet 6 and the precedingly printed sheet 7,
electrostatic adhesion of the precedingly printed sheet 7 to the currently
processed sheet 6 is prevented so that only the sheet 6 is fed back in
returning direction D. After carrying out repeatedly the reciprocating
movement of the printing paper sheet in this manner, the printing paper
sheet 6 is entirely discharged by means of the discharge roller 4.
Immediately after the trailing end of the sheet 6 has left the discharge
roller, the paper sheet 6 is bent due to its weight and falls down between
the guide bars 2 in the direction indicated by tbe arrows E to rest on a
recei~ing face 3 of the discharge paper tray 1. For this, the pair of
guide bars 2 are fixed to the discharge paper tray 1 at their leg portions
ln spaced relation from one another a distance wider than the width of the
PAT 15890-1

2~2~
paper sheet 6, while respective upper supporting portions of the pair of
guide bars 2 are spaced apart a distance narrower than the width of the
paper sheet 6 so as to support the same. The length of the guide bars is
set to be longer than the length of the sheet. By such an arrangement, the
paper sheet 6 can be made to not contact the receiving face 3 of the trsy
or can be made to slightly contact the face 3 along the central portion B
of the sheet 6 when the sheet 6 is partly discharged during the course of
the reciprocating movement thereof. Consequently, after finishing
printing, the paper sheet 6 can fall onto the discharge paper tray.
Further, in order to ad~ust for different sizes of paper sheets, the tray l
is formed, on its end faces, with a plurality of support holes a, b for
supporting the guide bars 2 as shown in Figs. 1 and 2. When handling a
narrow sized paper sheet, the guide bars 2 are engaged in the holes a.
When treating a wider papar sheet, the other holes b are selected to fix or
support the guide bars 2.
As described above, according to the present invention, a pair of
guide bars are provided in spaced relation from one another in the
widthwise direction of a discharge paper tray so as to prevent reverse
rolling-in of discharged paper sheet such as OHP sheet to thereby prevent
paper jams. By such a simplified mechanism, there are achieved various
advantages such as product cost reduction, improved durability and improved
reliability with respect to repeated discharge performance.
PAT 15890-1
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