Electrophotography – Having particular structure – Modular or displaceable
Reexamination Certificate
2000-01-13
2001-04-10
Chen, Sophia S. (Department: 2852)
Electrophotography
Having particular structure
Modular or displaceable
C399S392000, C399S401000
Reexamination Certificate
active
06215970
ABSTRACT:
CROSS-REFERENCE TO RELATED APPLICATIONS
This document claims priority and contains subject matter related to Japanese Patent Application No. 11-006378 filed in the Japanese Patent Office on Jan. 13, 1999, and on Japanese Patent Application No. 11-049745 filed in the Japanese Patent Office on Feb. 26, 1999, and the entire contents of which are hereby incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a duplex unit that reverses a sheet to form images at both sides of the sheet, for use in an image forming apparatus such as a copying machine, a facsimile, a printer, or the like.
2. Discussion of the Background
As illustrated in
FIG. 12
, in a background image forming apparatus for forming images on both sides of a sheet, a reverse unit
101
for reversing a sheet is provided at a side (right side as viewed in
FIG. 12
) of a main body case
102
. The reverse unit
101
is rotatably provided around a first supporting shaft (not shown) which is provided at a lower part of the reverse unit
101
in the direction separating from the main body case
102
. Below the reverse unit
101
, a manual sheet feeding tray
103
that manually feeds a sheet is rotatably provided around a second supporting shaft
104
which is provided in a manual sheet feeding unit
117
in the direction separating from the main body case
102
.
The main body case
102
houses sheet feeding trays
105
, a sheet transfer path
109
, an image forming unit
107
, a fixing unit
108
, and a sheet stacker unit
106
. The sheet transfer path
109
is formed in the main body case
102
such that a sheet is conveyed from the sheet feeding tray
105
or the manual sheet feeding tray
103
to the sheet stacker unit
106
via the image forming unit
107
and the fixing unit
108
.
In a case
110
of the reverse unit
101
, a reverse path
111
and a refeed path
112
that is separated from the reverse path
111
are formed. At a separation point between the reverse path
111
and the refeed path
112
, a reverse roller
113
is provided. The reverse roller
113
is reversible and conveys the sheet that is guided in the reverse path
111
to the refeed path
112
in a switchback direction. A one end of the reverse path
111
connects to the sheet transfer path
109
in the main body case
102
and the other end connects to an opening
114
that is provided at the right-hand side of the case
110
in FIG.
12
and opens outward. The opening
114
is closed by a sheet reverse guide plate
115
. The sheet reverse guide plate
115
is rotatably supported around a supporting shaft
116
provided at the reverse unit
101
in the direction separating from the reverse unit
101
.
In the above-described image forming apparatus with the reverse unit
101
and the manual sheet feeding unit
117
, an image is formed on a sheet fed from the sheet feeding tray
105
or the manual sheet feeding tray
103
at the image forming unit
107
during the sheet passes through the sheet transfer path
109
. The sheet having the image is discharged to the sheet stacker unit
106
.
When images are formed on both sides of a sheet, the sheet having an image on one side is guided to the reverse path
111
. When the trailing edge of the sheet passes the separation point between the reverse
111
and the refeed path
112
, the reverse roller
113
is switched to rotate in the switchback direction (i.e., in the direction toward the refeed path
112
), and the sheet is conveyed to the refeed path
112
. The sheet is then conveyed to the sheet transfer path
109
again from the sheet refeed path
112
so as to have an image on the backside of the sheet in the image forming unit
107
, and is discharged to the sheet stacker unit
106
.
In the background image forming apparatus with the above-described configuration in
FIG. 12
, because the manual sheet feeding tray
103
is installed outside of the case
110
of the reverse unit
101
and is protruded from the case
110
, people passing by the image forming apparatus may accidentally contact and break the manual sheet feeding tray
103
. In addition, when an operator moves the image forming apparatus, the manual sheet feeding tray
103
may be opened due to vibration. As a result, the manual sheet feeding tray
103
may be broken by striking against surrounding items.
When a sheet is jammed in the sheet transfer path
109
, an operator makes an operation space for removing the jammed sheet by rotating the reverse unit
101
around the first supporting shaft in the direction separating from the main body case
102
. The operator reaches a hand into the space with the jammed sheet.
When the operator opens the reverse unit
101
for removing the jammed sheet in the sheet transfer path
109
, the manual sheet feeding tray
103
needs to be opened first, and then the reverse unit
101
can be opened. On the other hand, when the operator closes the reverse unit
101
after removing the jammed sheet, the reverse unit
101
is closed first, and then the manual sheet feeding tray
103
needs to be closed. In other words, the operator needs to open and close not only the reverse unit
101
but also the manual sheet feeding tray
103
to remove the jammed sheet (i.e., the operator needs to perform two steps). The operator is therefore unnecessarily inconvenienced by opening and closing the reverse unit
101
and the manual sheet feeding tray
103
when the operator removes a jammed sheet.
Further, when a sheet having a length in the sheet conveying direction longer than the length of the reverse path
111
between the reverse roller
113
and the opening
114
(hereinafter referred to as a large size sheet) is reversed in the reverse unit
101
, an operator needs to open the opening
114
by rotating the sheet reverse guide plate
115
around the supporting shaft
116
to protrude the leading edge of the large size sheet from the case
110
. The open condition of the sheet reverse guide plate
115
is indicated by a dotted line in FIG.
12
. In addition, when the manual sheet feeding tray
103
is closed, the operator needs to open the manual sheet feeding tray
103
first, and then rotate the sheet reverse guide plate
115
to protrude the leading edge of the large size sheet from the case
110
.
Furthermore, when the operator uses an image forming apparatus installed at a place apart from an operator by a remote operation and when a large size sheet is reversed in the reverse unit
101
, the operator needs to go to the image forming apparatus to rotate the sheet reverse guide plate
115
around the supporting shaft
116
and open the opening
114
. Opening the sheet reverse guide plate
115
every time a large sized sheet is reversed in the reverse unit
101
becomes a burden on the operator. If an additional device for opening the sheet reverse guide plate
115
by a remote operation is installed to the image forming apparatus, an installation space and a number of construction parts increase in the image forming apparatus.
SUMMARY OF THE INVENTION
The present invention has been made in view of the above-discussed and other problems, and an object of the present invention is to address these problems.
The preferred embodiments of the present invention provide a novel duplex unit and image forming apparatus, in which a breakdown of manual sheet feeding tray caused by a protruded manual sheet feeding tray is prevented.
The preferred embodiments of the present invention provide a novel duplex unit and image forming apparatus that improve operability in opening and closing a duplex unit.
The preferred embodiments of the present invention provide a novel duplex unit and image forming apparatus that reverse various sizes of sheets efficiently without additional operations.
In order to achieve the above and other objectives, the present invention provides a novel duplex unit including a case housing a sheet reverse path that connects to a sheet discharging outlet and a sheet refeed inlet provided on a side of a main body case housing an image forming unit an
Fukube Noriaki
Yoshikawa Masaaki
Chen Sophia S.
Oblon & Spivak, McClelland, Maier & Neustadt P.C.
Ricoh & Company, Ltd.
LandOfFree
Duplex unit with recess for retracting manual sheet feeding... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Duplex unit with recess for retracting manual sheet feeding..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Duplex unit with recess for retracting manual sheet feeding... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2483944