Sheet feeding or delivering – Feeding – Pack holders
Reexamination Certificate
1999-10-04
2001-06-12
Ellis, Christopher P. (Department: 3651)
Sheet feeding or delivering
Feeding
Pack holders
C271S162000, C399S393000
Reexamination Certificate
active
06244588
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an electrophotographic copying machine, an image forming apparatus such as a laser beam printer or a facsimile machine or the like, which is equipped with a sheet feeding device.
2. Related Background Art
A conventional image forming apparatus equipped with a sheet feeding device has, for instance, a structure shown in FIG.
7
.
A sheet feeding cassette
101
for supporting sheets on which images are formed is mounted on a main body of the apparatus. Reference numeral
102
designates a photosensor for detecting whether or not sheets supported by the sheet feeding cassette
101
are present. When there is no sheet in the cassette
101
, an actuator
102
a
drops to a hole part
101
a
provided on the bottom plate of the cassette
101
, so that the photosensor
102
is turned on. Thus, the detection of no sheets on the cassette can be carried out.
Further, a cassette sensor
106
is provided for detecting whether or not the cassette
101
is mounted on the main body of the apparatus and a protruding part
101
b
is also provided on the cassette side corresponding to the sensor
106
.
A rack
103
is formed on the lower part of the side surface of the cassette
101
and a pinion
105
driven to rotate by a motor
104
meshes with the rack
103
.
In the structure described above, when all the sheets supported by the cassette
101
are fed so that there is no sheet on the cassette
101
, the actuator
102
a
abutting on the sheets drops to the hole part
101
a
. Thus, the photosensor
102
interrupted by the actuator
102
a
is turned on, so that no sheet is detected. When the motor
104
is rotated counterclockwise for a prescribed time under this condition, the cassette
101
is automatically drawn out from the apparatus on which it is mounted because of the engagement of the rack
103
with the pinion
105
. Thus, it can be recognized at a glance that the sheets are used up, and hence a user near the apparatus can be notified of a supply of more sheets to the cassette.
However, there have been encountered problems mentioned below in the above described prior art.
Specifically, since the conventional apparatus is designed to drive the motor
104
to automatically draw out the cassette
101
after the detection of no sheets on the cassette
101
, the motor for drawing out the cassette
101
needs to be provided. Besides, as transfer members for transferring the driving force of the motor to the cassette
101
, members such as the pinion
103
or the rack
105
must be provided.
Further, since a mounting detection sensor for detecting whether or not the sheets are housed in the cassette
101
needs to be provided, it is necessary to provide two sensors including the former sensor and the cassette sensor
106
for detecting whether or not the cassette is mounted on the main body of the apparatus.
Still further, since the frequency of operations for drawing out the cassette
101
from the apparatus is not more than that of ordinary image forming operations and the cassette
101
on which a large quantity of sheets are stacked has been mainly employed on the latest image forming apparatus, the frequency of supply of sheets to the cassette
101
is further reduced as compared with that of the prior art.
Therefore, the provision of the motor for drawing out the cassette
101
as well as the driving motor of the apparatus and the two sensors disadvantageously causes the number of parts to be increased and the cost of assembly to be increased, which would constitute a major factor to increase the cost of a product.
The present invention is devised by taking the above described problems into account and it is an object of the present invention to provide a sheet feeding device with a more simplified structure in which a user can readily supply sheets when the sheets supported by a sheet supporting means are used up in the supporting means, and an image forming apparatus provided with the sheet feeding device.
SUMMARY OF THE INVENTION
According to one aspect of the present invention, the above described object can be attained by providing a sheet feeding device comprising: a sheet supporting means for supporting sheets which is provided so as to be drawn out from a main body of the device, a feeding means abutting on the sheets supported by the sheet supporting means to feed the sheets, and a driving means for applying driving force for feeding the sheets to the sheet feeding means, wherein the sheet support means is moved in a direction in which the sheet supporting means is drawn out from the main body of the device by the driving force of the driving means for driving the feeding means when the sheets supported by the supporting means are completely used up.
REFERENCES:
patent: 5005817 (1991-04-01), Ruch et al.
patent: 5157448 (1992-10-01), Lang
patent: 5161794 (1992-11-01), Adachi
patent: 5163670 (1992-11-01), Sellers et al.
Adachi Nobukazu
Matsuo Yoshihiro
Tsubakimoto Yasuhito
Bower Kenneth W
Canon Kabushiki Kaisha
Ellis Christopher P.
Fitzpatrick ,Cella, Harper & Scinto
LandOfFree
Sheet feeding device and image forming apparatus equipped... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Sheet feeding device and image forming apparatus equipped..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Sheet feeding device and image forming apparatus equipped... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2449988