Incremental printing of symbolic information – Light or beam marking apparatus or processes – With record receiver or handling means therefor
Reexamination Certificate
1998-09-14
2001-10-09
Le, N. (Department: 2861)
Incremental printing of symbolic information
Light or beam marking apparatus or processes
With record receiver or handling means therefor
C347S153000, C399S025000, C399S111000, C399S388000, C400S629000
Reexamination Certificate
active
06300970
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an image forming apparatus such as a laser beam printer, a copying machine, a facsimile and the like and an improvement in a sheet supply portion of such an apparatus.
2. Related Background Art
Recently, laser beam printers have been made more compact and inexpensive, with the result that the laser beam printers which were used under limited conditions such as office equipment and/or business purposes have been used in private offices and/or homes since personal computers have progressed. To this end, the laser beam printers themselves have been improved so that the performance thereof is enhanced and so that they can easily be used by any person. For example, by only opening an open/close cover, the user himself can easily exchange consumed parts such as a process cartridge and easily effect jam treatment.
Further, in the past, a large number of sheets having certain characteristics recommended by electrophotographic makers were used. However, recently, various kinds of paper sheets (for example, no-brand low cost sheets, ink jet printing sheets and the like) available from stationery shops or discount stores have frequently been used. Further, for an individual, a user may use various sheets such as a post card, a letter-paper, an envelope and sheets having various thicknesses.
Since such sheets may have features different from features of sheets to be used in the apparatuses recommended by the makers, various problems may occur. For example, some kinds of paper sheets may reduce a friction force of a sheet supply roller for supplying a sheet to the laser beam printer, thereby causing poor sheet supply. More particularly, a coating on the sheet, a pigment coated on the sheet and/or additives to the sheet (talc, calcium carbonate or Kaolin) can adhere to and accumulate on a surface of the sheet supply roller, and, a rubber surface of the sheet supply roller is worn by a rough surface of the sheet or fibers of the sheet, thereby causing such problems.
Such sheet supply roller must be cleaned by using a solvent such as alcohol, or the sheet supply roller itself must be exchanged. However, since the solvent such as alcohol may not easily be available and the sheet supply roller cannot easily be exchanged by the user (even when the improvement is made so that anyone can handle the apparatus easily), generally, the user leaves repair of the apparatus to the maker.
To avoid this, it is requested to provide an arrangement in which any user can easily exchange the sheet supply roller. However, the conventional arrangements have the following disadvantages.
(1) Since the sheet supply roller is disposed within the body of the apparatus, a space available to exchange the sheet supply roller is small.
(2) As shown in
FIG. 7A
, in general, in a sheet supply roller unit
100
, a sheet supply roller
101
, a sheet supply sub-roller
102
and cams
106
,
109
are fitted on a sheet supply shaft
104
and are secured to the sheet supply shaft by fixing members
103
,
105
,
108
and
110
. When parts are exchanged, the unit
100
integrally including the sheet supply shaft
104
is dismounted from a body of the apparatus, and, as shown in
FIG. 7B
, the sub-roller
102
and the fixing members (parallel pins)
103
,
105
provided on the shaft are slid along a longitudinal direction of the shaft to be removed. Accordingly, it is difficult for the user to exchange the sheet supply roller.
(3) A sheet supply roller unit
122
shown in
FIG. 8
includes a rubber portion
122
a
having a high coefficient of friction and a sheet supply roller metal core
122
b.
In this unit, the user can easily exchange the sheet supply roller only by disengaging a pawl
122
c
of a snap fit
122
d
provided on the metal core
122
b
from a recess
120
a
provided in a shaft
120
and sliding the roller laterally. However, as shown in
FIG. 8
, the exchange of the sheet supply roller can be effected only when the sheet supply roller is supported by a bearing portion
121
in a cantilever fashion and other parts are not provided on the shaft. Other arrangements cannot be used.
SUMMARY OF THE INVENTION
An object of the present invention is to permit easy exchanging by a user of a sheet supply roller in an image forming apparatus.
To achieve the above objects, according to the present invention, there is provided an image forming apparatus comprising a sheet supply means having a detachable sheet supply roller for feeding stacked sheets, an image forming means having a process cartridge for forming an image on the sheet fed out by the sheet supply means, a cartridge containing portion for detachably containing the process cartridge within a body of the image forming apparatus, and a sheet discharge means for discharging and stacking the sheets on which the images were formed by the image forming means. Wherein, the sheet supply roller and the process cartridge are disposed adjacent to each other, and, after the process cartridge is disengaged from the cartridge containing portion, the sheet supply roller is mounted and dismounted through the cartridge containing portion.
REFERENCES:
patent: 4806977 (1989-02-01), Mizutani et al.
patent: 4810115 (1989-03-01), Hori
patent: 5208626 (1993-05-01), Tanimoto et al.
patent: 5331374 (1994-07-01), Abe et al.
patent: 5884117 (1999-03-01), Tanoue et al.
patent: 5896206 (1999-04-01), Kellogg
patent: 0 487 041 (1992-05-01), None
patent: 0 621 515 (1994-10-01), None
patent: 0 679 958 (1995-11-01), None
patent: 61-178334 (1986-08-01), None
patent: 06-92489 (1994-04-01), None
Adachi Nobukazu
Hamada Tatsuo
Canon Kabushiki Kaisha
Fitzpatrick ,Cella, Harper & Scinto
Le N.
Pham Hai C.
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