U.S. patent application number 12/983845 was filed with the patent office on 2011-04-28 for paper feeding apparatus with paper size detectors.
This patent application is currently assigned to Kabushiki Kaisha Toshiba. Invention is credited to Tokihiko Ise, Toshihiro Matsushima, Masahiro OHNO, Tetsuo Shiba, Yousuke Ushiyama.
Application Number | 20110095473 12/983845 |
Document ID | / |
Family ID | 40431009 |
Filed Date | 2011-04-28 |
United States Patent
Application |
20110095473 |
Kind Code |
A1 |
OHNO; Masahiro ; et
al. |
April 28, 2011 |
PAPER FEEDING APPARATUS WITH PAPER SIZE DETECTORS
Abstract
A paper feeding apparatus includes a cassette main body that
stacks a paper therein, a sidewall that moves in a width direction
of the cassette main body, an end wall that moves in a longitudinal
direction of the cassette main body, a first movable member that is
connected at one end to the sidewall and rotates around a shaft
axially fixed to the cassette main body in connection with the
sidewall, a second movable member that is connected at one end to
the end wall and rotates around a shaft axially fixed to the
cassette main body in connection with the end wall, a first
detection unit that has a plurality of detection members and
detects the size of the paper in the width direction, and a second
detection unit that has a plurality of detection members and
detects the size of the paper in the longitudinal direction.
Inventors: |
OHNO; Masahiro;
(Yokohama-shi, JP) ; Ushiyama; Yousuke;
(Mishima-shi, JP) ; Ise; Tokihiko; (Tagata-gun,
JP) ; Matsushima; Toshihiro; (Mishima-shi, JP)
; Shiba; Tetsuo; (Yokohama-shi, JP) |
Assignee: |
Kabushiki Kaisha Toshiba
Tokyo
JP
Toshiba Tec Kabushiki Kaisha
Tokyo
JP
|
Family ID: |
40431009 |
Appl. No.: |
12/983845 |
Filed: |
January 3, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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12765632 |
Apr 22, 2010 |
7887048 |
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12983845 |
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12207468 |
Sep 9, 2008 |
7731183 |
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12765632 |
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60971237 |
Sep 10, 2007 |
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60971238 |
Sep 10, 2007 |
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60971246 |
Sep 10, 2007 |
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60972237 |
Sep 13, 2007 |
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60988733 |
Nov 16, 2007 |
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60988751 |
Nov 16, 2007 |
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Current U.S.
Class: |
271/171 |
Current CPC
Class: |
B65H 1/266 20130101;
B65H 2511/10 20130101; B65H 2403/41 20130101; B65H 2403/51
20130101; B65H 2403/5331 20130101; B65H 2405/31 20130101; B65H
2511/20 20130101; B65H 2551/20 20130101; B65H 2405/111 20130101;
B65H 2220/04 20130101; B65H 2220/01 20130101; B65H 2511/20
20130101; B65H 2511/10 20130101 |
Class at
Publication: |
271/171 |
International
Class: |
B65H 1/00 20060101
B65H001/00 |
Claims
1. A paper feeding apparatus comprising: a cassette main body that
stacks a paper therein; a sidewall that moves in a width direction
of the cassette main body; an end wall that moves in a longitudinal
direction of the cassette main body; a first movable member that
rotates around a shaft axially fixed to the cassette main body in
connection with the sidewall, has a first detection portion and is
connected to the sidewall; a second movable member that rotates
around a shaft axially fixed to the cassette main body in
connection with the end wall, has a second detection portion and is
connected to the end wall; a first detection unit that detects the
size of the paper in the width direction according to the first
detection portion; a second detection unit that detects the size of
the paper in the longitudinal direction according to the second
detection portion; a paper sensor that detects presence of the
paper when the sidewall and the end wall are moved to positions to
come into contact with the paper and is provided on wall surfaces
near at least one of the sidewall and the end wall; and a display
that, when the paper sensor determines paper absence, displays
information that at least one of the sidewall and the end wall is
not set in accordance with the paper size.
2. The apparatus of claim 1, wherein, when the paper sensor
determines paper presence, and the size of the paper detected by
the first detection unit and the second detection unit is not
consistent with a predetermined size, the display displays that the
size of the paper is to be inputted.
3. The apparatus of claim 2, further comprising: a storage unit
that, when the paper size is inputted, stores combination
information of a patterns detected by the first detection unit and
a patterns detected by the second detection unit for the paper size
in association with the paper size; and a control unit that detects
the paper size by comparing the patterns detected by the first
detection unit and the patterns detected by the second detection
unit with the combination information stored in the storage unit
and displays result of detecting the paper size.
4. The apparatus of claim 3, wherein the control unit controls to
convey the paper by paper feed rollers when the control unit
detects that the paper size is correct.
5. The apparatus of claim 4, wherein, when the paper sensor
determines paper absence and the control unit discriminates the
paper size, the display displays information that the size of the
paper stacked in the cassette main body is different from the paper
size based on the combination information.
6. The apparatus of claim 1, wherein the paper sensor has an
actuator.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation of U.S. patent
application Ser. No. 12/765,632, filed Apr. 22, 2010, which is a
continuation of U.S. patent application Ser. No. 12/207,468, filed
Sep. 9, 2008, now U.S. Pat. No. 7,731,183, issued Jun. 8, 2010.
This application claims the benefit of U.S. Provisional
Applications No. 60/971,237, filed Sep. 10, 2007; No. 60/971,238,
filed Sep. 10, 2007; No. 60/971,246, filed Sep. 10, 2007; No.
60/972,237, filed Sep. 13, 2007; No. 60/988,733, filed Nov. 16,
2007; and No. 60/988,751, filed Nov. 16, 2007. Each of these
applications is herein incorporated by reference.
TECHNICAL FIELD
[0002] The present invention relates a paper feeding apparatus that
is capable of detecting the size of a paper stacked in a paper
cassette.
BACKGROUND
[0003] In the related art, an image forming apparatus or a paper
feeding apparatus is provided with a mechanism for detecting the
size of a paper stacked in a paper cassette. With the enhancement
of functionality of the image forming apparatus, the image forming
apparatus becomes complicated and has a lot of members. In terms of
user's convenience, it is undesirable that the image forming
apparatus is increased in height in a height direction. Therefore,
it is necessary to reduce the height of the paper cassette in the
paper feeding apparatus disposed at a lower end of the image
forming apparatus.
[0004] With the enhancement of functionality of the image forming
apparatus, in order to suppress an error when printing, it is
necessary to accurately detect the size of the paper stacked in the
paper cassette.
[0005] The paper cassette has a sidewall and an end wall that are
movable along a width direction of the stacked paper and a
longitudinal direction of the paper cassette. Two paper size
sensors for detecting the size of the paper stacked in the paper
cassette when the paper cassette is inserted into the paper feeding
apparatus are provided at a position opposed to the paper cassette
on the depth side of the paper feeding apparatus. Each of the paper
size sensors detects the size in the paper width direction or the
longitudinal direction of the paper cassette by combinations of
presses. A control unit detects the paper size on the basis of a
combination of the sizes in the paper width direction and the
longitudinal direction of the paper cassette detected by the two
paper size sensors.
[0006] The paper cassette is provided with a movable member that is
movable in accordance with the movement of the sidewall, and a
movable member that is movable in accordance with the movement of
the end wall. The movable members correspondingly press the paper
size sensors. At this time, the movable member connected to the
sidewall and the movable member connected to the end wall are
disposed in the paper cassette with the same rotation fulcrum.
[0007] FIGS. 47 and 48 show a related art example of a first
movable member 205 and a second movable member 206 provided in a
cassette main body 201. FIG. 47 is a diagram of a paper cassette
201 when viewed from its rear surface in a state where the paper
cassette 201 is inserted into an image forming apparatus 1. FIG. 48
is a diagram of a first sensor 102 and a second sensor 103 when
viewed from the depth side of the image forming apparatus 1.
[0008] As shown in FIG. 47, the first movable member 205 and the
second movable member 206 are disposed on the rear surface of the
cassette main body 201 on the same axis. Therefore, as shown in
FIG. 48, the first sensor 102 and the second sensor 103 are
arranged in the height direction on the same axis of the paper
feeding apparatus 20 or the image forming apparatus 1. For this
reason, the paper cassette 201 cannot be decreased in height
(JP-A-2005-280994).
[0009] When the printing position of an image is misaligned with
respect to the paper width direction, it is necessary to shift the
paper position in the paper cassette so as to be aligned with the
image to be printed (hereinafter, referred to as lateral
misalignment correction). When a user executes lateral misalignment
correction of a paper, the sidewall is also moved. For this reason,
the paper size sensors may detect a size different from a paper
size desired to be actually detected or may not specify any size.
For this reason, when the user executes the lateral misalignment
correction of the paper in the paper cassette, it is also necessary
to move the paper size sensors, which leads to complexity.
[0010] Instead of the lateral misalignment correction of the paper,
a method of correcting the position of an image when printing may
be used. In this case, however, it is necessary to set a printable
region in the image forming apparatus by an amount corresponding to
the amount of lateral misalignment correction. For this reason, the
image forming apparatus is increased in size, and manufacturing
costs become high. In addition, according to this method, the
position of the paper in the paper cassette is not corrected, and
accordingly the paper is conveyed into the apparatus at a position
different from a normal position. Then, the paper may collide
against an unexpected place, and paper jam or bending may occur.
When a lateral misalignment adjustment mechanism for the lateral
misalignment correction is provided, it is necessary for the user
to adjust the paper size sensors.
[0011] Accordingly, aspects of the invention provide a paper
feeding apparatus that is capable of accurately detecting the size
of a paper stacked in a paper cassette without increasing the size
of the apparatus.
SUMMARY
[0012] According to one aspect of the present invention, there is
provided a paper feeding apparatus comprising; a cassette main body
that stacks a paper therein, a sidewall that moves in a width
direction of the cassette main body, an end wall that moves in a
longitudinal direction of the cassette main body, a first movable
member that is connected at one end thereof to the sidewall,
rotates around a shaft axially fixed to the cassette main body in
connection with the sidewall, and has a first detection portion at
the other end thereof, a second movable member that is connected at
one end thereof to the end wall, rotates around a shaft axially
fixed to the cassette main body in connection with the end wall,
and has a second detection portion at the other end thereof, a
first detection unit that has a plurality of detection members and
detects the size of the paper in the width direction according to
the first detection portion provided in the first movable member,
and a second detection unit that has a plurality of detection
members and detects the size of the paper in the longitudinal
direction according to the second detection portion provided in the
second movable member.
DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a schematic view showing the exterior of an image
forming apparatus according to a first embodiment;
[0014] FIG. 2 is a block diagram showing a control system of a
paper feeding apparatus according to the first embodiment;
[0015] FIG. 3 is a top perspective view of a paper cassette
detachably mounted in the paper feeding apparatus according to the
first embodiment;
[0016] FIG. 4 is a bottom perspective view of the paper cassette
detachable mounted in the paper feeding apparatus according to the
first embodiment;
[0017] FIGS. 5A and 5B are diagrams showing the shapes of a first
movable member and a second movable member according to the first
embodiment;
[0018] FIG. 6 is a top perspective view of the paper cassette
detachably mounted in the paper feeding apparatus according to the
first embodiment;
[0019] FIG. 7 is a bottom perspective view of the paper cassette
detachably mounted in the paper feeding apparatus according to the
first embodiment;
[0020] FIG. 8 is a diagram showing the rear surface of the paper
cassette inserted into the paper feeding apparatus according to the
first embodiment;
[0021] FIG. 9 is a diagram of a first sensor and a second sensor
according to the first embodiment when viewed from the depth side
of the paper feeding apparatus;
[0022] FIG. 10 is a diagram of the first sensor and the second
sensor according to the first embodiment when viewed from the near
side of the paper feeding apparatus;
[0023] FIG. 11 is a diagram showing a sensor board according to a
second embodiment;
[0024] FIG. 12 is a diagram showing the structure of the sensor
board according to the second embodiment;
[0025] FIG. 13 is a top view showing engagement of a first movable
member and a second movable member with the sensor board according
to the second embodiment;
[0026] FIG. 14 is a top view showing engagement of the first
movable member and the second movable member with the sensor board
according to the second embodiment;
[0027] FIG. 15 is a top view showing engagement of the first
movable member and the second movable member with the sensor board
according to the second embodiment;
[0028] FIG. 16 is a bottom view showing engagement of the first
movable member and the second movable member with the sensor board
according to the second embodiment;
[0029] FIG. 17 is a flowchart showing detachment of the sensor
board according to the second embodiment;
[0030] FIG. 18 is a diagram showing the structure of a sensor board
according to a third embodiment;
[0031] FIG. 19 is a diagram showing the structure of the sensor
board according to the third embodiment;
[0032] FIG. 20 is a diagram showing the structure of the sensor
board according to the third embodiment;
[0033] FIG. 21 is a diagram showing the structure of a paper
cassette to be coupled to the sensor board according to the third
embodiment;
[0034] FIG. 22 is a diagram showing a state where the sensor board
according to the third embodiment and the paper cassette are
coupled to each other;
[0035] FIG. 23 is a diagram showing a paper sensor provided at a
front-side sidewall according to a fourth embodiment;
[0036] FIG. 24 is a diagram showing the paper sensor provided at a
rear-side sidewall according to the fourth embodiment;
[0037] FIG. 25 is a diagram showing the paper sensor provided at an
end wall according to the fourth embodiment;
[0038] FIG. 26 is a flowchart showing paper size detection by the
paper sensor according to the fourth embodiment;
[0039] FIG. 27 is a top perspective view showing a part of a paper
cassette according to a fifth embodiment;
[0040] FIG. 28 is a diagram showing coupling of the rear-side
sidewall and the first movable member according to the fifth
embodiment;
[0041] FIG. 29 is a diagram showing coupling of the rear-side side
wall and the first movable member according to the fifth
embodiment;
[0042] FIG. 30 is a diagram showing the stretched state of a
front-side sidewall and the rear-side sidewall according to the
fifth embodiment;
[0043] FIG. 31 is a diagram showing the retracted state of the
front-side sidewall and the rear-side sidewall according to the
fifth embodiment;
[0044] FIG. 32 is a top perspective view showing the paper cassette
according to the fifth embodiment;
[0045] FIG. 33 is a diagram showing a pinion gear mounted on the
paper cassette according to the fifth embodiment;
[0046] FIG. 34 is a diagram showing the pinion gear before being
mounted on the paper cassette according to the fifth
embodiment;
[0047] FIG. 35 is a diagram showing the rear surface of a pinion
gear holding member according to the fifth embodiment;
[0048] FIG. 36 is a sectional view showing the pinion gear
according to the fifth embodiment;
[0049] FIG. 37 is a sectional view of the pinion gear according to
the fifth embodiment;
[0050] FIG. 38 is a diagram showing the pinion gear holding member
mounted on the paper cassette according to the fifth
embodiment;
[0051] FIG. 39 is a diagram showing the rear surface of the pinion
gear holding member according to the fifth embodiment;
[0052] FIG. 40 is a diagram showing lateral misalignment correction
of a paper by the pinion gear holding member according to the fifth
embodiment;
[0053] FIG. 41 is a diagram showing the first movable member and a
first connection member according to the fifth embodiment;
[0054] FIG. 42 is a diagram showing lateral misalignment correction
of a paper by the first connection member according to the fifth
embodiment;
[0055] FIG. 43 is a sectional view of the first connection member
according to the fifth embodiment;
[0056] FIG. 44 is a top view showing a paper cassette provided with
a first link member according to a sixth embodiment;
[0057] FIG. 45 is a top view showing the paper cassette provided
with a lateral misalignment detection unit according to the sixth
embodiment;
[0058] FIG. 46 is a diagram showing press of a first movable member
205 on a first sensor 102 according to the sixth embodiment;
[0059] FIG. 47 is a diagram showing the rear surface of a paper
cassette inserted into a known paper feeding apparatus; and
[0060] FIG. 48 is a diagram of known first sensor and second sensor
when viewed from the depth side of the image forming apparatus.
DETAILED DESCRIPTION
[0061] Hereinafter, embodiments will be described.
[0062] FIG. 1 is a perspective view showing the exterior of an
image forming apparatus 1 according to an embodiment. The image
forming apparatus 1 has an image forming unit 10 that outputs image
information as an output image, called hard copy or print out, a
paper feeding apparatus 20 that is capable of feeding a paper
(output medium) of an arbitrary size for image output to the image
forming unit 10, and a scanner 50 that acquires image information
to be formed in the image forming unit 10 from an object
(hereinafter, referred to as original document) including image
information as image data. The paper feeding apparatus 20 has a
paper cassette 201 (shown in FIG. 3) that accommodates papers of an
arbitrary size and is attached with respect to the paper feeding
apparatus 20. When the original document is sheet-like, the scanner
50 is provided with an automatic document feeder 30 that, after
image output is formed or image information is read, discharges the
read original document from a read position to a discharge
position, and guides a next original document to the read position.
In addition, an instruction input unit for instructing the image
forming unit 10 to start image formation or instructing the scanner
50 to read image information of the original document, that is, a
control panel 40 is provided at a predetermined position.
[0063] Here, a side on which the paper cassette 201 shown in FIG. 3
is attached to the paper feeding apparatus 20 is defined as the
near side of the image forming apparatus 1 or the paper feeding
apparatus 20. A side opposite to the side on which the paper
cassette 201 shown in FIG. 3 is attached to the paper feeding
apparatus 20 is defined as the depth side of the image forming
apparatus 1 or the paper feeding apparatus 20. A paper discharge
tray 60 for discharging a paper printed in the image forming unit
10 is provided on a side surface of the image forming apparatus 1.
A first opening and closing member 70 and a second opening and
closing member 80 are provided on a side surface opposite to the
side on which the paper discharge tray 60 is provided.
[0064] The first opening and closing member 70 is a paper convey
unit that is provided so as to be connected to the image forming
unit body 10. The second opening and closing member 80 is a manual
paper feed unit that is provided so as to abut to the first opening
and closing member 70.
[0065] FIG. 2 is a block diagram showing the control system of the
paper feeding apparatus 20 according to this embodiment.
[0066] A control device 2 has a CPU 3, a ROM 4, and a RAM 5. The
CPU 3 controls individual sensors and motors on the basis of
control information previously recorded in the ROM 4. The RAM 5
temporarily records necessary information.
[0067] FIG. 3 is a top perspective view of the paper cassette 201
detachably mounted in the paper feeding apparatus 20. An arrow x
denotes a mounting direction with respect to the paper feeding
apparatus 20.
[0068] The paper feeding apparatus 20 is provided with paper feed
rollers 101 that, when the paper cassette 201 is inserted, convey a
bundle of papers stacked in the paper cassette 201 one by one from
the top to the image forming unit 10. The paper feed rollers 101
convey the paper in a Y direction perpendicular to an X direction
in which the paper cassette 201 is inserted into the paper feeding
apparatus 20.
[0069] Near the positions in contact with the side surfaces on the
near and depth side of a bundle of papers stacked in the paper
cassette 201, a front-side sidewall 202F (near side) and a
rear-side sidewall 202R (depth side) are provided. The front-side
sidewall 202F (near side) and the rear-side sidewall 202R move in
the X direction (hereinafter, referred to as the width direction of
the paper cassette 201) perpendicular to the Y direction in which
the paper is conveyed.
[0070] The front-side sidewall 202F and the rear-side sidewall 202R
are formed to be movable, for example, in 1.0 mm pitch by two
pinion gears 213 and a pinion gear holding member 212. If one of
the front-side sidewall 202F and the rear-side sidewall 202R moves,
the other one moves (described with reference to FIG. 26). The
front-side sidewall 202F and the rear-side sidewall 202R are spaced
at a predetermined interval (allowance) in order to eliminate a
shift in parallelism with respect to the Y direction in which the
paper set in the paper cassette 201 is conveyed, and regulate the
position of the paper in the width direction.
[0071] The paper cassette 201 is provided with a pressing plate 203
that presses the entire paper against the paper feed rollers 101
from the bottom (bottom surface) of the paper cassette 201 in order
to make sure conveyance of the paper by the paper feed rollers
101.
[0072] At an end opposite to the paper feed rollers 101 in the Y
direction (the longitudinal direction of the paper cassette 201) in
which the paper stacked in the paper cassette 201 is conveyed, an
end wall 204 is provided. The end wall 204 moves back and forth
with respect to the longitudinal direction of the paper cassette
201, and regulates the position of the paper cassette 201 in the
longitudinal direction. An end of the paper in contact with the end
wall 204 is referred to as a paper rear end.
[0073] FIG. 4 is a bottom perspective view of the paper cassette
201 detachably mounted in the paper feeding apparatus 20. On the
rear surface of the paper cassette 201, a first movable member 205
and a second movable member 206 are provided. FIGS. 5A and 5B show
the shapes of the first movable member 205 and the second movable
member 206. The first movable member 205 (or the second movable
member 206) has a comb-teeth member 2051 (2061) which is arc-shaped
and having a plurality of protrusions and serving as a detection
portion. The first movable member 205 (or the second movable member
206) has a first joint groove 2052 (2062), a shaft hole 2053
(2063), and a second joint groove 2054 (2064).
[0074] The first movable member 205 and the second movable member
206 are axially supported on the rear surface of the paper cassette
201 through the shaft hole 2053 and the shaft hole 2063,
respectively, so as to rotate around a shaft. The rear-side
sidewall 202R on the depth side provided in the upper surface of
the paper cassette 201 and the second joint groove 2054 of the
first movable member 205 disposed on the rear surface of the paper
cassette 201 are connected by a first connection member 207. The
rear-side sidewall 202R is threadably mounted from the rear-side
sidewall 202R side by the first connection member 207. Similarly,
the end wall 204 provided in the upper surface of the paper
cassette 201 and the second joint groove 2064 of the second movable
member 206 disposed on the rear surface of the paper cassette 201
are connected by a second connection member 208. The end wall 204
is threadably mounted from the end wall 204 side by the second
connection member 208. As for the first movable member 205 and the
second movable member 206, the first joint groove 2052 and the
second joint groove 2062 are connected with each other by the
second connection member 208.
[0075] FIG. 6 is a top perspective view of the paper cassette 201
detachably mounted in the paper feeding apparatus 20. FIG. 7 is a
bottom perspective view of the paper cassette 201 detachably
mounted in the paper feeding apparatus 20.
[0076] The paper cassette 201 shown in FIGS. 6 and 7 is in a state
where, when a paper of a smaller size than the paper stacked in the
paper cassette 201 shown in FIGS. 3 and 4 is stacked, the
front-side sidewall 202F, the rear-side sidewall 202R, and the end
wall 204 are moved.
[0077] If the front-side sidewall 202F and the rear-side sidewall
202R move from the state shown in FIG. 3 and to the state shown in
FIG. 6 in a direction to narrow an interval of the paper cassette
201 in the width direction, the first connection member 207 rotates
the first movable member 205 around the shaft while moving in the
second joint groove 2054.
[0078] If the end wall 204 moves from the state shown in FIG. 3 to
the state shown in FIG. 6 in a direction to narrow an interval of
the paper cassette 201 in the longitudinal direction, the second
connection member 208 rotates the second movable member 206 around
the shaft while moving in the second joint groove 2064.
[0079] Next, a description will be provided for a first sensor 102
and a second sensor 103 serving as a detection unit provided on the
depth side of the paper feeding apparatus 20 when the paper
cassette 201 is inserted into the paper feeding apparatus 20. FIG.
8 is a diagram showing the rear surface of the paper cassette 201
when the paper cassette 201 is inserted into the paper feeding
apparatus 20. FIG. 9 is a diagram of the first sensor 102 and the
second sensor 103 when viewed from the depth side of the paper
feeding apparatus 20. FIG. 10 is a diagram of the first sensor 102
and the second sensor 103 when viewed from the near side of the
paper feeding apparatus 20.
[0080] In the paper feeding apparatus 20, the first sensor 102 is
provided at a position in contact with the comb-teeth member 2051
provided in the first movable member 205 on the depth side of the
paper feeding apparatus 20 when the paper cassette 201 is inserted
into the paper feeding apparatus 20. In addition, in the paper
feeding apparatus 20, the second sensor 103 is provided at a
position in contact with the comb-teeth member 2061 provided in the
second movable member 206 on the depth side of the paper feeding
apparatus 20 when the paper cassette 201 is inserted into the paper
feeding apparatus 20.
[0081] The first sensor 102 has four protrusion members 1021
serving as detection members that protrude from the depth side to
the near side. Similarly, the second sensor 103 has four protrusion
members 1031 that protrude from the depth side to the near side.
The CPU 3 discriminates the size of the paper cassette 201 in the
width direction by combinations of presses of the four protrusion
members 1021 provided in the first sensor 102. Similarly, the CPU 3
detects the size of the paper cassette 201 in the longitudinal
direction by combinations of presses of the four protrusion members
1031 provided in the second sensor 103. The CPU 3 discriminates the
size of the paper stacked in the paper cassette 201 on the basis of
the size of the paper cassette 201 in the width direction and the
size of the paper cassette 201 in the longitudinal direction.
[0082] The first movable member 205 is rotated in accordance with
the movements of the front-side sidewall 202F and the rear-side
sidewall 202R, and accordingly the comb-teeth member 2051 in
contact with the first sensor 102 is change in shape. Therefore,
the first sensor 102 detects the size of the paper cassette 201 in
the width direction by press patterns of the comb-teeth member 2051
on the four protrusion members 1021 provided in the first sensor
102.
[0083] Similarly, the second movable member 206 is rotated in
accordance with the movement of the end wall 204, and accordingly
the comb-teeth member 2061 in contact with the second sensor 103 is
changed in shape. Therefore, the second sensor 103 detects the size
of the paper cassette 201 in the longitudinal direction by press
patterns of the comb-teeth member 2061 on the four protrusion
members 1031 provided in the second sensor 103.
[0084] In this embodiment, as shown in FIG. 8, the first movable
member 205 and the second movable member 206 are disposed on the
rear surface of the paper cassette 201 on different axes, not on
the same axis. A connection shaft of the first movable member 205
to the paper cassette 201 and a connection shaft of the second
movable member 206 to the paper cassette 201 are provided to be
arranged along the width direction of the paper cassette 201, which
is the horizontal direction of the image forming apparatus 1.
[0085] As shown in FIG. 10, the first sensor 102 and the second
sensor 103 have the same shape. The first sensor 102 has four
protrusion members 1021 provided on a boxlike member 1022, in which
a board is incorporated, in the horizontal direction of the image
forming apparatus 1. The second sensor 103 has four protrusion
members 1031 provided on a boxlike member 1032, in which a board is
incorporated, in the horizontal direction of the image forming
apparatus 1.
[0086] The protrusion members 1021 have a columnar shape having a
diameter smaller than the height of the boxlike member 1022 of the
first sensor 102. The boxlike member 1022 of the first sensor 102
has a height equal to or larger than the thickness of the first
movable member 205. Similarly, the protrusion members 1031 have a
columnar shape having a diameter smaller than the height of the
boxlike member 1032 of the second sensor 103. The boxlike member
1032 of the second sensor 103 has a height equal to larger than the
thickness of the second movable member 206.
[0087] For this reason, if the first sensor 102 and the second
sensor 103 are arranged in the height direction on the same axis of
the paper feeding apparatus 20, the boxlike member 1022 of the
first sensor 102 and the boxlike member 1022 of the second sensor
103 are superimposed and increase in height. In this embodiment, as
shown in FIG. 10, the shaft of the first movable member 205 and the
shaft of the second movable member 206 are provided to be arranged
along the width direction of the paper cassette 201. A position
where the comb-teeth member 2051 of the first movable member 205 is
opposed to the first sensor 102 and a position where the comb-teeth
member 2061 of the second movable member 206 is opposed to the
second sensor 103 are shifted in the horizontal direction.
[0088] As shown in FIG. 10, the first sensor 102 and the second
sensor 103 are provided on the depth side of the paper feeding
apparatus 20 to be shifted in the horizontal direction at positions
not opposed to each other in the height direction. The first sensor
102 and the second sensor 103 are provided so as to at least
partially overlap each other in the horizontal direction.
[0089] An interval a between a center axis in the horizontal
direction of the protrusion members 1022 arranged in the first
sensor 102 and a center axis in the horizontal direction of the
protrusion members 1032 arranged in the second sensor 103 is
narrowed, as compared with a case where the first sensor 102 and
the second sensor 103 are disposed to overlap each other in the
height direction. Therefore, the paper cassette 201 is reduced in
height, as compared with the related art example.
[0090] The first movable member 205 and the second movable member
206 are disposed in the paper cassette 201 to be axially shifted in
the width direction of the paper cassette 201. However, since the
paper cassette 201 has a size corresponding to a paper of a
stackable maximum size, even if the first movable member 205 and
the second movable member 206 are axially shifted in the width
direction of the paper cassette 201, there is no case where the
structure is increased in size.
[0091] Next, a second embodiment will be described. FIG. 11 is a
diagram showing a sensor board 300 which is disposed on the depth
side of the paper feeding apparatus 20 and on which the first
sensor 102 and the second sensor 103 are provided.
[0092] The first sensor 102 and the second sensor 103 are arranged
on the same sensor board 300 in the horizontal direction. The
sensor board 300 is structurally detachably fixed and electrically
connected to a housing 11 of the paper feeding apparatus 20 so as
to be detachable from. The sensor board 300 is adapted to be
electrically connected to the paper feeding apparatus 20. FIG. 12
shows the sensor board 300 that is held by the housing 11 of the
paper feeding apparatus 20. The sensor board 300 is mounted with
respect to the housing 11 from the near side of the paper feeding
apparatus 20 to the depth side. The sensor board 300 has a first
claw member 313 and a second claw member 314. The first claw member
313 is a plate spring that has elasticity in a direction
perpendicular to the mounting direction of the sensor board 300.
The second claw member 314 has the same structure as the first claw
member 313. In addition, the first claw member 313 has an opening
3131 of a predetermined size. The second claw member 314 also has
an opening 3141 of a predetermined size.
[0093] As shown in FIG. 12, the first movable member 205 has a
first sensor board holding portion 2055 in a part of the comb-teeth
member 2051, and the second movable member 206 has a second sensor
board holding portion 2065 in a part of the comb-teeth member
2061.
[0094] A front end of the first sensor board holding portion 2055
is engaged with an opening 3131 provided in the first claw member
313 in a shape smaller than the opening 3131. In addition, the
front end of the first sensor board holding portion 2055 is moved
to a position opposed to the opening 3131 provided in the first
claw member 313 by rotation of the first movable member 205.
Similarly, a front end of the second sensor board holding portion
2065 is engaged with an opening 3141 provided in the second claw
member 314 in a shape smaller than the opening 3141. In addition,
the front end of the second sensor board holding portion 2065 is
moved to a position opposed to the opening 3141 provided in the
second claw member 314 by rotation of the second movable member
206.
[0095] FIG. 13 shows a state where the front-side sidewall 202F,
the rear-side sidewall 202R, and the end wall 204 are moved to
predetermined positions, and the second sensor board holding
portion 2065 is engaged with the opening 3141 provided in the
second claw member 314. If the front-side sidewall 202F and the
rear-side sidewall 202R are moved in the width direction of the
paper cassette 201, the first movable member 205 is rotated around
the shaft in accordance with the movement. For this reason, when
the front-side sidewall 202F and the rear-side sidewall 202R are
opened in the width direction of the paper cassette 201, as shown
in FIG. 12, the first sensor board holding portion 2055 is engaged
with the opening 3131 provided in the first claw member 313.
[0096] Similarly, if the end wall 204 is moved in the longitudinal
direction of the paper cassette 201, the second movable member 206
is rotated around the shaft in accordance with the movement. For
this reason, when the end wall 204 is opened in the longitudinal
direction of the paper cassette 201, as shown in FIG. 13, the
second sensor board holding portion 2065 is engaged with the
opening 3141 of the first claw member 314. In addition, if the end
wall 204 is opened full in the longitudinal direction of the paper
cassette 201, the second sensor board holding portion 2065 bends
the second claw member 314 in a direction away from the housing 11.
Similarly, if the front-side sidewall 202F and the rear-side
sidewall 202R are opened full in the width direction of the paper
cassette 201, the first sensor board holding portion 2055 bends the
second claw member 313 in a direction away from the housing 11.
[0097] FIG. 15 is a diagram showing coupling of the first movable
member 205 and the second movable member 206, and the sensor board
300 when viewed from the upper surface. FIG. 16 is a diagram
showing coupling of the first movable member 205 and the second
movable member 206, and the sensor board 300 when viewed from the
lower surface. If the front-side sidewall 202F, the rear-side
sidewall 202R, and the end wall 204 are moved to predetermined
positions, the first sensor board holding portion 2055 is engaged
with the first claw member 313, and the second sensor board holding
portion 2065 is engaged with the second claw member 314. As shown
in FIGS. 15 and 16, the sensor board 300 is held by the first
sensor board holding portion 2055 and the second sensor board
holding portion 2065. Then, as shown in FIG. 14, the sensor board
300 is spaced away from the housing 11 by the first sensor board
holding portion 2055 and the second sensor board holding portion
2065.
[0098] In this state, if a serviceman draws out the paper cassette
201 from the paper feeding apparatus 20, the sensor board 300 is
drawn out together with the first movable member 205 and the second
movable member 206 in a state where the sensor board 300 is held by
the first movable member 205 and the second movable member 206. To
the contrary, if the serviceman inserts the paper cassette 201 into
the image forming apparatus 1 in a state where the sensor board 300
is held by the first movable member 205 and the second movable
member 206, the sensor board 300 is placed at a predetermined
position in the paper feeding apparatus 20.
[0099] If the end wall 204 is in a state other than the full opened
state in the longitudinal direction of the paper cassette 201, as
shown in FIG. 13, the second claw member 314 returns to a hold
position with respect to the housing 11. Similarly, when the
front-side sidewall 202F and the rear-side sidewall 202R are in a
state other than the full opened state in the width direction of
the paper cassette 201, the first claw member 313 returns to a hold
position with respect to the housing 11. It is easy for the
serviceman to detach and attach the sensor board 300 with respect
to the paper feeding apparatus 20.
[0100] FIG. 17 is a flowchart showing the flow of detachment of the
sensor board 300.
[0101] First, the serviceman sets the end wall 204, the front-side
sidewall 202F, and the rear-side sidewall 202R of the paper
cassette 201 at predetermined positions (Act 101).
[0102] Next, the serviceman mounts the paper cassette 201 in the
paper feeding apparatus 20 (Act 102). The serviceman puts the end
wall 204 in the full opened state in the longitudinal direction of
the paper cassette 201, and puts the front-side sidewall 202F and
the rear-side sidewall 202R in the full opened state in the width
direction of the paper cassette 201. The first movable member 205
and the second movable member 206 rotate around the shaft (Act
103).
[0103] Since the first movable member 205 and the second movable
member 206 hold the sensor board 300, the serviceman can draw out
the sensor board 300 from the paper feeding apparatus 20 together
with the paper cassette 201 (Act 104).
[0104] Next, a third embodiment will be described.
[0105] FIG. 18 is a perspective view of the paper cassette 201 and
the sensor board 300 mounted in the paper feeding apparatus 20 when
viewed from the depth side of the paper feeding apparatus 20. In
the paper feeding apparatus 20, guide rail members 12 for holding
the paper cassette 201 mountable on the paper feeding apparatus 20
and enabling the paper cassette 201 to be drawn out from the paper
feeding apparatus 20 are provided in the housing 11. The sensor
board 300 is disposed on the depth side of the paper feeding
apparatus 20 opposed to the paper cassette 201. The paper cassette
201 is positioned with respect to the housing 11.
[0106] FIG. 19 shows the structure of the sensor board 300
according to this embodiment. The sensor board 300 has a holder
member 311 and a float member 304 in combination. The holder member
311 has a positioning member 303, a first holder boss 305, and a
second holder boss 306. The positioning member 303 is engaged with
the housing 11 of the paper feeding apparatus 20. For this reason,
the absolute position of the holder member 311 with respect to the
paper feeding apparatus 20 is fixed. The first holder boss 305 and
the second holder boas 306 are protrusions. The float member 304 is
provided with an opening 307, an opening 308, an opening 309, and
an opening 310. The opening 309 has a shape extending in the
horizontal direction. In the float member 304, the first sensor 102
and the second sensor 103 are provided as a single body.
[0107] The first holder boss 305 that is a protrusion provided in
the holder member 311 is fitted into the opening 307 of the float
member 304. The second holder boss 306 that is a protrusion
provided in the holder member 311 is fitted into the opening 308 of
the float member 304. The opening 307 and the opening 308 have a
diameter larger than those of the first holder boss 305 and the
second holder boss 306, respectively. Therefore, the float member
304 has a degree of freedom with respect to the holder member 311.
As shown in FIG. 20, the float member 304 is fixed by a plurality
of fixing portions 3111 provided in the holder member 311, and the
movement of the float member 304 in the front-back direction is
limited. Therefore, the float member 304 that is made of a plate
has a degree of freedom in the holder member 311 in a direction
indicated by an arrow in the drawing.
[0108] FIG. 21 is a diagram showing the rear surfaces of the sensor
board 300 and the paper cassette 201. On a surface of the paper
cassette 201 opposed to the sensor board 300, a first boss 209 and
a second boss 210 protrude in an extension direction. The float
member 304 has at least openings corresponding to or more than the
number of bosses provided in the paper cassette 201. The first boss
209 is fitted into the opening 310 provided in the float member
304. The second boss 210 is fitted into the opening 309 provided in
the float member 304. The first boss 209 and the second boss 210
have a slim shape along the extension direction so as to be easily
guided to the opening 310 and the opening 309, respectively. The
opening 310 and the opening 309 are purled such that the first boss
209 and the second boss 210 are easily fitted thereinto.
[0109] If the paper cassette 201 is inserted with the sensor board
300 fixed to the housing 11 of the paper feeding apparatus 20, the
first boss 209 and the second boss 210 are individually fitted into
the opening 310 and the opening 309 of the sensor board 300. The
opening 310 and the opening 309 are provided in the float member
304. In the float member 304, the first sensor 102 and the second
sensor 103 are provided as a single body.
[0110] Therefore, as shown in FIG. 22, the first movable member 205
and the second movable member 206 provided in the paper cassette
201 are constantly accurately opposed to the first sensor 102 and
the second sensor 103, respectively. That is, the relative
positional relationship between the first movable member 205 and
the first sensor 102 and the relative positional relationship
between the second movable member 206 and the second sensor 103 are
constantly uniform by the float member 304. The correlation of the
first movable member 205 and the first sensor 102, and the
correlation of the second movable member 206 and the second sensor
103 are secured. Therefore, there is no case where the first sensor
102 and the second sensor 103 perform erroneous detection.
[0111] The first boss 209 provided in the paper cassette 201 is
fitted into the opening 310 to position the float member 304. The
second boss 210 provided in the paper cassette 201 is fitted into
the opening 309 to position the float member 304 in the vertical
direction and to suppress rotation of the float member 304.
[0112] In the related art, the first sensor 102 and the second
sensor 103 are fixed to the housing 11. For this reason, the first
movable member 205 and the first sensor 102 and the second movable
member 206 and the second sensor 103 have a variation in the
relative positional relationship due to a cumulative tolerance,
assembling accuracy, and part accuracy caused by a lot of parts
between parts in contact with each other.
[0113] According to the sensor board 300 of this embodiment, the
relative positions of the first sensor 102 and the second sensor
103 are reliably determined with respect to the paper cassette 201
by an inexpensive and simple method. For this reason, it is
possible to avoid erroneous detection due to misalignment of the
first sensor 102 and the second sensor 103.
[0114] The first boss 209 and the second boss 210 are individually
fitted into the opening 310 and the opening 309 provided in the
float member 304. Therefore, with the degree of freedom of the
float member 304, the paper cassette 201 can be easily inserted and
drawn out. As a result, the user's operational load in inserting
and drawing out the paper cassette 201 is reduced.
[0115] Next, a fourth embodiment will be described.
[0116] FIG. 23 is an enlarged view of the front-side sidewall 202F
in the paper cassette 201 shown in FIG. 3. FIG. 24 is an enlarged
view of the rear-side sidewall 202R in the paper cassette 201 shown
in FIG. 3. FIG. 25 is an enlarged view of the end wall 204 in the
paper cassette 201 shown in FIG. 3.
[0117] As shown in FIGS. 23, 24, and 25, paper sensors 211 are
individually provided on the wall surfaces near at least one of the
front-side sidewall 202F, the rear-side sidewall 202R, and the end
wall 204. As the paper sensors 211, for example, an actuator is
used. If the front-side sidewall 202F and the rear-side sidewall
202R are moved in accordance with the size of the paper stacked in
the paper cassette 201, the paper sensors 211 are in contact with
the paper, and the CPU 3 determines that the front-side sidewall
202F and the rear-side sidewall 202R are moved to positions to come
into contact with the paper. The same is applied to the paper
sensor 211 provided on the end wall 204. The paper sensors 211 may
be a non-contact sensor, for example, a reflection-type sensor or a
distance measurement sensor.
[0118] Even though the CPU 3 determines the paper size from the
detection results of the first sensor 102 and the second sensor
103, when the paper sensors 211 determine paper absence, the CPU 3
determines that a paper of a different size (small size) from the
paper size detected from the combination of the detection results
of the first sensor 102 and the second sensor 103 is stacked. The
CPU 3 displays on the control panel 40 serving as a notification
unit a purport to urge the user to correctly set the front-side
sidewall 202F and the rear-side sidewall 202R or the end wall
204.
[0119] With the above configuration, the user can reliably set the
front-side sidewall 202F and the rear-side sidewall 202R or the end
wall 204 for the paper stacked in the paper cassette 201.
Therefore, the paper size detected by the CPU 3 from the
combination of the detection results of the first sensor 102 and
the second sensor 103 is consistent with the size of the paper
stacked in the paper cassette 201.
[0120] A description will now be provided for a case where the user
stacks a paper of an irregular size in the paper cassette 201, and
reliably sets the front-side sidewall 202F and the rear-side
sidewall 202R, and the end wall 204 for the paper. The RAM 5
records combinations of detection patterns of the first sensor 102
and the second sensor 103 in advance. Then, the CPU 3 discriminates
the paper size by comparing the combination of detection patterns
of the first sensor 102 and the second sensor 103 and size
associated information in which combinations of detection patterns
recorded in the RAM 5 are associated with paper sizes. The
irregular size refers to a paper size that the CPU 3 cannot
discriminate by comparison of the combination of the detection
patterns of the first sensor 102 and the second sensor 103 with
information recorded in the RAM 5.
[0121] Therefore, when the CPU 3 determines that the detection
results of the first sensor 102 and the second sensor 103 are not
associated with information recorded in the RAM 5 (not a regular
size), the CPU 3 displays on the control panel 40 a purport that
the paper size cannot be discriminated.
[0122] The user inputs the paper size in accordance with the
display on the control panel 40. The CPU 3 records the input paper
size in the RAM 5 in association with the combination of detection
patterns of the first sensor 102 and the second sensor 103.
Thereafter, if the user stacks a paper of a corresponding size in
the paper cassette 201, and reliably sets the front-side sidewall
202F and the rear-side sidewall 202R, and the end wall 204 for the
paper, the CPU 3 can reliably detect the paper size by comparing
the combination of detection patterns of the first sensor 102 and
the second sensor 103 with information recorded in the RAM 5.
Therefore, as described above, if the user inputs a paper size at
one time, when the user stacks a paper of an irregular size in the
paper cassette 201, it is not necessary for the control panel 40 to
set the paper size.
[0123] FIG. 26 is a flowchart collectively showing the flow of this
process.
[0124] First, the user stacks a paper in the paper cassette 201 and
moves the front-side sidewall 202F, the rear-side sidewall 202R,
and the end wall 204 in accordance with the paper size. The paper
sensors 211 attached at predetermined positions of the end wall
204, the front-side sidewall 202F, and the rear-side sidewall 202R
detect whether or not a paper is present therearound, and
determines whether or not the front-side sidewall 202F, the
rear-side sidewall 202R, and the end wall 204 are set in accordance
with the paper size (Act 201).
[0125] If the paper sensors 211 determine that the end wall 204 (or
the front-side sidewall 202F and the rear-side sidewall 202R) are
correctly set (Act 201, YES), the CPU 3 determines whether or not a
combination of detection patterns of the first sensor 102 and the
second sensor 103 is associated with information on paper size
recorded in the RAM 5 (Act 202).
[0126] When the CPU 3 can discriminate the paper size (Act 202,
YES), the CPU 3 conveys the paper by the paper feed rollers 101
driven by a paper feed roller motor 400 (Act 203).
[0127] If the paper sensor 211 determines that the end wall 204 (or
the front-side sidewall 202F and the rear-side sidewall 202R) are
not correctly set (Act 201, NO), the CPU 3 displays on the control
panel 40 a purport to urge the user to correctly set the end wall
204 (or the front-side sidewall 202F and the rear-side sidewall
202R) in accordance with the paper (Act 204).
[0128] After the paper cassette 201 is drawn out from the paper
feeding apparatus 20, if the CPU 3 determines that the paper
cassette 201 is inserted into the paper feeding apparatus 20 again
(Act 205), the process returns to Act 201.
[0129] When the paper size cannot be discriminated (Act 202, NO),
the CPU 3 displays on the control panel 40 a purport that a paper
of an irregular size is stacked (Act 206). That is, the user can
draw out the paper cassette 201 to confirm whether or not the size
of the paper stacked in the paper cassette 201 is an intended
size.
[0130] The user draws out the paper cassette 201, determines that
the end wall 204 (or the front-side sidewall 202F and the rear-side
sidewall 202R) are not correctly set in accordance with the paper,
selects NO (Act 207, NO), and correctly sets the end wall 204 (or
the front-side sidewall 202F and the rear-side sidewall 202R).
Then, if it is determined that the paper cassette 201 is inserted
into the paper feeding apparatus 20 again (Act 208), the process
returns to Act 201.
[0131] When the user draws out the paper cassette 201 and
determines that the end wall 204 (or the front-side sidewall 202F
and the rear-side sidewall 202R) are correctly set in accordance
with the paper (Act 207, YES), if the CPU 3 determines that the
paper size is not correct (Act 209, NO), the user inputs the paper
size in accordance with the display on the control panel 40 (Act
211). The CPU 3 records the input paper size in the RAM 5 in
association with a combination of detection patterns of the first
sensor 102 and the second sensor 103 (Act 211). If the CPU 3
determines that the paper size is correct (Act 209, YES), the CPU 3
conveys the paper by the paper feed rollers 101 driven by the paper
feed roller motor 400 (Act 210).
[0132] With this configuration, when a paper of a size different
from the paper size determined by the CPU 3 is stacked in the paper
cassette 201, an error is displayed on the control panel 40.
Therefore, a paper of a different size is not conveyed to the image
forming unit 10. As a result, in the image forming unit 10, it is
possible to prevent paper jam or deterioration in printing position
accuracy from occurring due to a difference in paper size.
[0133] Next, a fifth embodiment will be described. FIG. 27 is a top
perspective view of a part of the paper cassette 201 shown in FIG.
3. Here, the front-side sidewall 202F has a front-side rack portion
2021 that has a predetermined length in the width direction of the
paper cassette 201. The rear-side sidewall 202R has a rear-side
rack portion 2022 that has a predetermined length in the width
direction of the paper cassette 201. The front-side rack portion
2021 and the rear-side rack portion 2022 are arranged in parallel
to be spaced at a predetermined interval from each other. Two
pinion gears 213 are disposed between the front side rack portion
2021 and the rear-side rack portion 2022. In order to fix the
pinion gears 213, a pinion gear holding member 212 serving as a
position correction member is disposed on the upper surface of the
pinion gear 213 and fixed to the paper cassette 201.
[0134] FIGS. 28 and 29 show connection of the rear-side sidewall
202R and the first movable member 205 when viewed from the rear
surface of the paper cassette 201. To the rear-side sidewall 202R,
a first connection member 207 that protrudes toward the rear
surface of the paper cassette 201 is fixed by a screw 214. The
first connection member 207 is fitted into a second joint groove
2054 provided in the first movable member 205. Accordingly, the
first movable member 205 is rotated around the shaft in accordance
with the operation of the first connection member 207 by movement
of the rear-side sidewall 202R in the width direction of the paper
cassette 201.
[0135] FIG. 30 is a diagram showing a state the front-side sidewall
202F and the rear-side sidewall 202R are stretched in the width
direction of the paper cassette 201. FIG. 31 is a diagram showing a
case where the front-side sidewall 202F and the rear-side sidewall
202R are retracted in the width direction of the paper cassette
201. The two pinion gears 213 are disposed between the front-side
rack portion 2021 and the rear-side rack portion 2022. In the
front-side rack portion 2021 and the rear-side rack portion 2022,
grooves are provided at a regular interval on opposing sides along
the longitudinal direction. The pinion gears 213 are fitted between
the front-side rack portion 2021 and the rear-side rack portion
2022. Grooves that are provided in the outer peripheral surfaces of
the pinion gears 213 at a regular interval are meshed with the
groove in the front-side rack portion 2021 and the groove in the
rear-side rack portion 2022. The pinion gears 213 are fixed to the
paper cassette 201 by the pinion gear holding member 212.
Therefore, the positional relationship between the pinion gears 213
and the paper cassette 201 are fixed. As a result, if the
front-side sidewall 202F moves in the width direction, the
rear-side sidewall 202R also moves from the center axis of the
paper tray 20 in the longitudinal direction by the same interval as
the movement interval of the front-side sidewall 202F through the
pinion gears 213.
[0136] FIG. 32 is a top perspective view of the paper cassette 201.
FIG. 33 is a diagram showing the paper cassette 201 in a state
where the pinion gears 213 and the pinion gear holding member 212
are mounted in the paper cassette 201. FIG. 34 is a diagram of the
paper cassette 201 when the pinion gears 213 and the pinion gear
holding member 212 are disassembled from the paper cassette 201.
FIG. 35 is a diagram showing a state where the pinion gears 213 are
mounted in the paper cassette 201, and a surface (rear surface) of
the pinion gear holding member 212 opposed to the paper cassette
201.
[0137] In the paper cassette 201 sandwiched between the front-side
rack portion 2021 and the rear-side rack portion 2022, a first
fixing portion 215 and a second fixing portion 216 are provided to
be spaced at a predetermined interval from each other in the width
direction of the paper cassette 201. The first fixing portion 215
is provided at a position near the front-side sidewall 202F. The
second fixing portion 216 is provided at a position near the
rear-side sidewall 202R. In the first fixing portion 215 and the
second fixing portion 216, grooves are provided at a regular
interval (here, 1 mm) along the width direction of the paper
cassette 201.
[0138] On the rear surface of the pinion gear holding member 212,
as shown in FIG. 35, a first correction member 2121 is provided to
be opposed to the first fixing portion 215 provided in the paper
cassette 201. In addition, on the rear surface of the pinion gear
holding member 212, a second correction member 2122 is provided to
be opposed to the second fixing portion 216 provided in the paper
cassette 201. In the first correction member 2121 and the second
correction member 2122, grooves are formed at a regular interval
(here, 1 mm) along the width direction of the paper cassette 201
when being mounted in the paper cassette 201.
[0139] On the rear surface of the pinion gear holding member 212,
two holding protrusions 2123 are provided between the first
correction member 2121 and the second correction member 2122 along
the width direction of the paper cassette 201 when being mounted in
the paper cassette 201. The two holding protrusions 2123 provided
in the pinion gear holding member 212 hold the pinion gears 213,
respectively, when the pinion gear holding member 212 is mounted in
the paper cassette 201. In addition, on the rear surface of the
pinion gear holding member 212, a position fixing protrusion 2124
is provided at the center in the width direction of the paper
cassette 201 when being mounted in the paper cassette 201. The
position fixing protrusion 2124 provided in the pinion gear holding
member 212 is fitted into a fixing hole 219 when the pinion gear
holding member 212 is mounted in the paper cassette 201. The first
correction member 2121 of the pinion gear holding member 212 is
fastened to the opposing first fixing portion 215 by a screw 217.
Similarly, the second correction member 2122 of the pinion gear
holding member 212 is fastened to the opposing second fixing
portion 216 by a screw 218.
[0140] FIGS. 36 and 37 are sectional views taken along the line C-C
of FIG. 35 in the width direction of the paper cassette 201. In the
first fixing portion 215, a plurality of grooves are provided at
intervals of 1 mm along the width direction of the paper cassette
201. The serrated teeth at regular intervals provided in the first
fixing portion 215 and the second fixing portion 216 define a
movement pitch of lateral misalignment correction (described below)
by the pinion gear holding member 212.
[0141] The position fixing protrusion 2124 provided in the pinion
gear holding member 212 is fitted into the fixing hole 219 of the
paper cassette 201, and the pinion gear holding member 212 is fixed
to the paper cassette 201. This fixed state is defined as a normal
state. In the normal state, when the paper is stacked in the paper
cassette 201, the front-side sidewall 202F and the rear-side
sidewall 202R arrange the paper such that the just center of the
paper cassette 201 in the width direction becomes the center axis
of the paper in the longitudinal direction.
[0142] Next, lateral misalignment correction of the paper by the
pinion gear holding member 212 will be described. FIG. 38 is a
diagram showing the paper cassette 201 in a state where the pinion
gears 213 and the pinion gear holding member 212 are mounted in the
paper cassette 201. FIG. 39 is a diagram showing the rear surface
of the pinion gear holding member 212. FIG. 40 is a diagram showing
lateral misalignment correction by the pinion gear holding member
212.
[0143] Here, a description will be provided for a case where the
paper stacked in the paper cassette 201 is shifted by 1 mm to the
depth side (an arrow direction of FIG. 38) of the paper cassette
201. As shown in FIG. 35, the position fixing protrusion 2124 is
provided on the rear surface of the pinion gear holding member 212.
The pinion gear holding member 212 is fixed to the paper cassette
201 in a state where the position fixing protrusion 2124 is
provided on the rear surface of the pinion gear holding member 212
in the normal state. The position fixing protrusion 2124 is removed
from the pinion gear holding member 212 shown in FIG. 39.
Therefore, the user can fix the pinion gear holding member 212 with
the position fixing protrusion 2124 removed to be shifted in the
width direction of the paper cassette 201.
[0144] Here, the pinion gear holding member 212 is provided with a
movement distance measurement member 221 at an end near the
rear-side sidewall 202R in the width direction of the paper
cassette 201. A front end of the movement distance measurement
member 221 is shaped to be perpendicular to the width direction of
the paper cassette 201. As shown in FIG. 40, at a predetermined
position in the width direction of the paper cassette 201, a scale
unit 221 is provided between the second fixing portion 216 and the
rear-side sidewall 202R. The scale unit 221 has scale marks
provided at regular intervals (here, 1 mm) in the width direction
of the paper cassette 201, similarly to the first fixing portion
215 and the second fixing portion 216.
[0145] A left view in FIG. 40 shows a case where in the normal
state, the pinion gear holding member 212 is fixed to the paper
cassette 201. The front end of the movement distance measurement
member 221 of the pinion gear holding member 212 is located at a
reference scale mark as a predetermined reference position of the
scale unit 221.
[0146] A center view of FIG. 40 illustrates movement of the pinion
gear holding member 212 when lateral misalignment correction is
performed to shift the paper stacked in the paper cassette 201 by 1
mm toward the depth side of the paper cassette 201. Usually, the
rear-side sidewall 202R and the front-side sidewall 202F move in
the width direction of the paper cassette 201 with the pinion gear
holding member 212 and the pinion gears 213 fixed to the pinion
gear holding member 212 as a center. Therefore, if the positions of
the pinion gear holding member 212 and the pinion gears 213 fixed
to the pinion gear holding member 212 in the width direction of the
paper cassette 201 are shifted, the front-side sidewall 202F and
the rear-side sidewall 202R arrange the paper such that the
position shifted from the center in the width direction of the
paper cassette 201 becomes the center axis in the longitudinal
direction of the paper. This is lateral misalignment
correction.
[0147] The first fixing portion 215, which is opposed to the first
correction member 2121 provided in the pinion gear holding member
212, and the second fixing portion 216, which is opposed to the
second correction member 2122 provided in the pinion gear holding
member 212, are provided with grooves at an interval of 1 mm.
Therefore, the user can move the pinion gear holding member 212 and
the pinion gears 213 fixed to the pinion gear holding member 212 in
an interval of 1 mm.
[0148] If the user moves the pinion gear holding member 212 and the
pinion gears 213 fixed to the pinion gear holding member 212 by 1
mm toward the rear-side sidewall 202R, the front end of the
movement distance measurement member 221 of the pinion gear holding
member 212 is located at a scale mark ahead of the predetermined
reference scale mark of the scale unit 221 by 1 mm.
[0149] A right view of FIG. 40 illustrates movement of the pinion
gear holding member 212 when lateral misalignment correction is
performed to shift the paper stacked in the paper cassette 201 by 2
mm toward the depth side of the paper cassette 201. Similarly, if
the user moves the pinion gear holding member 212 and the pinion
gears 213 fixed to the pinion gear holding member 212 by 2 mm
toward the rear-side sidewall 202R, the front end of the movement
distance measurement member 221 of the pinion gear holding member
212 is located at a scale mark ahead of the predetermined reference
scale mark of the scale unit 221 by 2 mm.
[0150] Therefore, the user can read the value of the scale unit 221
indicated by the front end of the movement distance measurement
member 221, thereby easily viewing how much lateral misalignment
correction is made.
[0151] Here, when the user moves the pinion gear holding member 212
to perform lateral misalignment correction on the front-side
sidewall 202F and the rear-side sidewall 202R, the first movable
member 205 connected to the rear-side sidewall 202R by the first
connection member 207 rotates at a different rotation angle from
that in the normal state. Therefore, in a state where lateral
misalignment correction is made, a press pattern of the comb-teeth
member 2051 of the first movable member 205 against the four
protrusion members 1021 is different from a press pattern of the
comb-teeth member 2051 of the first movable member 205 against the
four protrusion members 1021 in the normal state. The first sensor
102 may erroneously detect the size of the paper cassette 201 in
the width direction in a state where lateral misalignment
correction is made.
[0152] In this embodiment, the first movable member 205 in a state
where lateral misalignment correction is made is moved to a
position different from the first movable member 205 in the normal
state.
[0153] FIG. 41 is a diagram of the first movable member 205 and the
first connection member 207 when viewed from the rear surface of
the paper cassette 201. FIG. 42 is a diagram showing lateral
misalignment correction of the first movable member 205 by the
first connection member 207. FIG. 42 is a sectional view taken
along the line E-E of FIG. 41.
[0154] As shown in FIG. 28, the first connection member 207 that
protrudes toward the rear surface of the paper cassette 201 is
fixed by the screw 214. Then, as shown in FIG. 41, the first
connection member 207 is fitted into the second joint groove 2054
provided in the first movable member 205.
[0155] Here, on the surface of the rear-side sidewall 202R which
the first connection member 207 is in contact with, a groove 222 is
provided at a regular interval (here, 1 mm) along the same
direction as the movement direction of the front-side sidewall 202F
and the rear-side sidewall 202R.
[0156] As shown in FIG. 42, on the surface of the first connection
member 207 which the rear-side sidewall 202R is in contact with, a
groove portion 2071 is also provided at a regular interval (here, 1
mm). That is, the groove 222 of the rear-side sidewall 202R and a
groove provided in the groove portion 2071 of the first connection
member 207 are the same interval as the grooves provided in the
first fixing portion 215 and the second fixing portion 216, and the
interval between the scale marks provided in the scale unit
221.
[0157] A left view of FIG. 43 shows a state where in the normal
state, the first connection member 207 is fitted into the groove
222 of the rear-side sidewall 202R. In the normal state, a
protrusion 2072 that is provided at a predetermined reference
position of the first connection member 207 is fitted into a cutout
2023 provided at a predetermined position of the rear-side sidewall
202R.
[0158] A center view of FIG. 43 illustrates movement of the first
connection member 207 when lateral misalignment correction is
performed to shift the paper stacked in the paper cassette 201 by 1
mm toward the depth side of the paper cassette 201. The user can
draw out the protrusion 2072 of the first connection member 207,
thereby moving the first connection member 207 in a direction in
which the groove 222 of the rear-side sidewall 202R is provided. In
this case, the user can move the first connection member 207 from
the reference position by 1 mm in a direction from the front-side
sidewall 202F toward the rear-side sidewall 202R.
[0159] When the pinion gear holding member 212 and the pinion gears
213 fixed to the pinion gear holding member 212 are moved from the
reference position by 1 mm, the first connection member 207 is also
moved from the reference position by 1 mm. Therefore, the first
sensor 102 acquires the same pattern as that when in the normal
state, the comb-teeth member 2051 of the first movable member 205
presses the four protrusion members 1021.
[0160] A right view of FIG. 43 illustrates movement of the first
connection member 207 when lateral misalignment correction is
performed to shift the paper stacked in the paper cassette 201 by 2
mm toward the depth side of the paper cassette 201. In this case,
the user can move the first connection member 207 by 2 mm from the
reference position in a direction from the front-side sidewall 202F
toward the rear-side sidewall 202R.
[0161] When the pinion gear holding member 212 and the pinion gears
213 fixed to the pinion gear holding member 212 are moved from the
reference position by 2 mm, the first connection member 207 is also
moved from the reference position by 2 mm. Therefore, the first
sensor 102 acquires the same pattern as that when in the normal
state, the comb-teeth member 2051 of the first movable member 205
presses the four protrusion members 1021.
[0162] As described above, the user moves the first connection
member 207 by the same distance according to the movement of the
pinion gear holding member 212 and the pinion gears 213 fixed to
the pinion gear holding member 212. Therefore, even if lateral
misalignment correction is made, there is no case where the first
sensor 102 erroneously detects the paper size. In addition, what is
necessary is that the user moves the pinion gear holding member 212
and the first connection member 207 by the same distance.
Therefore, it is possible to suppress the occurrence of erroneous
detection due to a variation in lateral misalignment
correction.
[0163] The protrusion 2072 provided in the first connection member
207 is used to hold the position of the first connection member 207
in the normal state. For this reason, there is no case where the
first connection member 207 is erroneously attached when
assembling. Therefore, there is no case where the first sensor 102
erroneously detects the paper size due to an error in assembling.
In addition, for lateral misalignment correction of the paper, it
is necessary for the user to bend (remove) the position fixing
protrusion 2124 of the pinion gear holding member 212 and the
protrusion 2072 of the first connection member 207. For this
reason, it is possible to prevent the user from executing the
lateral misalignment correction of the paper more than necessary,
and it is possible to make the user to recognize that both the
pinion gear holding member 212 and the first connection member 207
need to be moved in sets.
[0164] In this embodiment, the first connection member 207 is fixed
to the rear surface of the rear-side sidewall 202R, but it may be
fixed so as to movable with respect to the groove portion 2071
provided in the upper surface of the rear-side sidewall 202R.
[0165] Next, a sixth embodiment will be described. Here, a case
where lateral misalignment correction of the paper by the pinion
gear holding member 212 shown in FIG. 40 is made will be described.
In the fifth embodiment, the first movable member 205 in which
lateral misalignment correction is performed is moved to a
different position from the position of the first movable member
205 in the normal state, but in the sixth embodiment, as shown in
FIG. 44, the sensor board 300, that is, the first sensor 102 is
shifted by the first link member 220.
[0166] The link member 220 is, for example, a rod-shaped member
that is connected to the pinion gear holding member 212. The link
member 220 is provided in a direction from the front-side sidewall
202F toward the rear-side sidewall 202R, and extends to a position
beyond the paper tray 20. As shown in the center view of FIG. 40,
if the user moves the pinion gear holding member 212 toward the
rear-side sidewall 202R, the first link member 220 is moved by the
same distance in the same direction in connection with the pinion
gear holding member 212.
[0167] Here, the sensor board 300 is provided in the housing 11 of
the image forming apparatus 1. The sensor board 300 is provided in
the housing 11 such that the first sensor 102 and the second sensor
103 are moved in the movement direction of the first link member
220, that is, in a direction perpendicular to the rear-side
sidewall 202R and the end wall 204.
[0168] Since the first link member 220 is in contact at 45 degrees
with a second link member 312 at a predetermined place of the
sensor board 300, the sensor board 300 is moved by the same
distance in accordance with the movement of the first link member
220. Therefore, when the user executes lateral misalignment
correction by using the pinion gear holding member 212, the first
link member 220 is also move in the same direction. The first link
member 220 moves the sensor board 300, and thus it is possible to
prevent the first sensor 102 of the sensor board 300 from
erroneously detecting the size of the paper cassette 201 in the
width direction when lateral misalignment correction is made. The
first link member 220 moves the sensor board 300, thereby
correcting an error in size detection due to lateral misalignment
correction.
[0169] Next, other examples will be described. As shown in FIG. 45,
the pinion gear holding member 212 is provided with a lateral
misalignment detection unit 221. The lateral misalignment detection
unit 221 detects the amount of movement from the normal state if
the pinion gear holding member 212 is moved from the normal
state.
[0170] If the pinion gear holding member 212 is moved from the
normal state for lateral misalignment correction, a press pattern
of the comb-teeth member 2051 of the first movable member 205
against the four protrusion members 1021 is different from a press
pattern of the comb-teeth member 2051 of the first movable member
205 against the four protrusion members 1021 in the normal
state.
[0171] Here, when the pinion gear holding member 212 is in the
normal state, the RAM 5 records size associated information in
which press patterns of the four protrusion members 1021 provided
in the first sensor 102 are associated with the paper sizes in the
width direction of the paper cassette 201. In addition, when the
pinion gear holding member 212 undergoes lateral misalignment
correction in units of 1 mm from the normal state, the RAM 5
records size associated information in which press patterns of the
four protrusion members 1021, which vary depending on the amount of
movement due to lateral misalignment correction, are associated
with the paper sizes.
[0172] Hereinafter, a specific example will be described. FIG. 46
is a diagram showing a state where the four protrusion members 1021
provided in the first sensor 102 are pressed by the first movable
member 205. As shown in FIG. 10, for convenience of explanation,
the four protrusion members 1021 provided in the first sensor 102
are called a protrusion a, a protrusion b, a protrusion c, and a
protrusion d when viewed from the near side of the image forming
apparatus 1.
[0173] A description will be provided for a case where the user
moves the front-side sidewall 202F and rear-side sidewall 202R in
accordance with a paper size A in the normal state. The comb-teeth
member 2051 of the first movable member 205 presses the protrusion
a and the protrusion c, for example, from among the four
protrusions 1021. The CPU 3 compares a press pattern of the four
protrusion members 1021 of the first sensor 102 with size
associated information recorded in the RAM 5, in which the press
patterns are associated with the paper sizes. When the press
pattern is consistent with the size associated information, the CPU
3 determines that a paper of size A is stacked in the paper
cassette 201.
[0174] Similarly, the user moves the front-side sidewall 202F and
the rear-side sidewall 202R in accordance with a paper size B in
the normal state. The comb-teeth member 2051 of the first movable
member 205 presses the protrusion b and the protrusion d, for
example, from among the four protrusion members 1021. When the
press pattern is consistent with the size associated information
recorded in the RAM 5, the CPU 3 determines that a paper of size B
is stacked in the paper cassette 201.
[0175] Here, a description will be provided for a case where the
user moves the pinion gear holding member 212 by 1 mm from the
normal state by lateral misalignment correction. The user moves the
front-side sidewall 202F and the rear-side sidewall 202R in
accordance with the paper size A in a state where lateral
misalignment correction is made by 1 mm. At this time, unlike the
normal state, the comb-teeth member 2051 of the first movable
member 205 presses the protrusion b and the protrusion d from among
the four protrusion members 1021. When, the press pattern is
consistent with the size associated information recorded in the RAM
5, and thus the CPU 3 erroneously determines that a paper of size B
is stacked in the paper cassette 201.
[0176] In this embodiment, the RAM 5 records the size associated
information in which in the normal state, the press pattern of the
protrusions b and d from among the four protrusion members 1021 is
associated with the paper size B. In addition, the RAM 5 records
the size associated information in which, in a state where lateral
misalignment correction is made by 1 mm, the press pattern of the
protrusions b and d from among the four protrusion members 1021 is
associated with the paper size A.
[0177] If the movement distance measurement member 221 determines
that the pinion gear holding member 212 undergoes lateral
misalignment correction by 1 mm, when comparing the press pattern
by the first movable member 205 with the size associated
information, the CPU 3 acquires from the RAM 5 size associated
information when lateral misalignment correction is made by 1 mm
and executes the comparison.
[0178] Similarly, the RAM 5 records size associated information in
which, when the pinion gear holding member 212 undergoes lateral
misalignment correction by 2 mm from the normal state, press
patterns of the four protrusion members 1021 are associated with
the paper sizes. The same is applied to a case where the pinion
gear holding member 212 undergoes lateral misalignment correction
by 3 mm or more from the normal state.
[0179] Therefore, if the movement distance measurement member 221
serving as a correction sensor measures a movement distance of the
pinion gear holding member 212 for lateral misalignment correction,
when comparing the press pattern by the first movable member 205
with size associated information, the CPU 3 acquires size
associated information according to the movement distance subjected
to lateral misalignment correction from the RAM 5 and executes the
comparison.
[0180] As described above, since the RAM 5 has size associated
information according to the movement distance subjected to lateral
misalignment correction, the CPU 3 can reliably discriminate the
size of a paper actually stacked in the paper cassette 201. In this
example, the RAM 5 records size associated information, in which
press patterns of the first movable member 205 against the sensors
of the first sensor 102 are associated with the paper size,
according to the movement distance subjected to lateral
misalignment correction, but the same is applied to the press
patterns of the second movable member 206 against the sensors of
the second sensor 103.
[0181] With the above-described configuration, lateral misalignment
correction and accurate paper size detection by the first sensor
102 can be compatibly achieved.
[0182] In the foregoing example, a plurality of protrusion members
1021 are provided in the first sensor 102, and the comb-teeth
member 2051 of the first movable member 205 presses the protrusion
members 1021. Alternatively, instead of the protrusion members
1021, an optical sensor or a magnetic sensor may be provided. In
this case, instead of the comb-teeth member 2051, a plurality of
holes or metal pieces transmitting light may be provided to the
first movable member 205. The same is applied to the second sensor
103 or the second movable member 206.
* * * * *