U.S. patent application number 13/559848 was filed with the patent office on 2012-11-22 for paper conveying apparatus, image forming apparatus and ink-jet recording apparatus.
This patent application is currently assigned to RICOH COMPANY, LTD. Invention is credited to Shinji IMOTO.
Application Number | 20120292848 13/559848 |
Document ID | / |
Family ID | 38778564 |
Filed Date | 2012-11-22 |
United States Patent
Application |
20120292848 |
Kind Code |
A1 |
IMOTO; Shinji |
November 22, 2012 |
PAPER CONVEYING APPARATUS, IMAGE FORMING APPARATUS AND INK-JET
RECORDING APPARATUS
Abstract
A sheet of paper is conveyed by a convey roller to a print
receiving member and pushed forward thereon while being supported
by ribs and pressed downward by pressing members so as to keep a
predetermined distance between the paper and a recording head while
an image is printed on the paper. Since the pressing members press
respective side portions of the paper, the paper can be bent
downward outside the outmost ribs and prevented from rising at the
side portions.
Inventors: |
IMOTO; Shinji; (Tokyo,
JP) |
Assignee: |
RICOH COMPANY, LTD
Tokyo
JP
|
Family ID: |
38778564 |
Appl. No.: |
13/559848 |
Filed: |
July 27, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11996566 |
Jan 23, 2008 |
8256764 |
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PCT/JP2007/060753 |
May 22, 2007 |
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13559848 |
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Current U.S.
Class: |
271/188 |
Current CPC
Class: |
B41J 11/0005 20130101;
B65H 5/38 20130101; B65H 2801/12 20130101; B65H 2404/61 20130101;
B65H 2301/5122 20130101; B41J 13/10 20130101 |
Class at
Publication: |
271/188 |
International
Class: |
B65H 29/70 20060101
B65H029/70 |
Foreign Application Data
Date |
Code |
Application Number |
May 26, 2006 |
JP |
2006-146861 |
Mar 14, 2007 |
JP |
2007-065640 |
Claims
1-24. (canceled)
25. A paper conveying apparatus comprising: multiple paper pressing
members configured to include at least one paper pressing member
which presses a side of a sheet of paper in a direction orthogonal
to a paper conveying direction, and other paper pressing members
which press a portion of the sheet of paper other than the side,
wherein a pressing mount of the at least one paper pressing member
is greater than the pressing amounts of the other paper pressing
members in a perpendicular direction with respect to a surface of
the sheet of paper.
26. The paper conveying apparatus as claimed in claim 25, wherein
the other paper pressing member are arranged at location to press a
side of a sheet of paper having a small width when the sheet of
paper having the small width is conveyed.
27. The paper conveying apparatus as claimed in claim 25, further
comprising one or more support members configured to support the
sheet of paper from below.
28. The paper conveying apparatus as claimed in claim 25, further
comprising at least one pressing amount limiting member configured
to press the side of the sheet of paper and to limit the pressing
amounts of the multiple paper pressing members.
29. The paper conveying apparatus as claimed in claim 28, wherein
the at least one pressing amount limiting member, which pressed the
side of the sheet of paper, supports the sheet of paper from
below.
30. The paper conveying apparatus as claimed in claim 28, wherein
the at least one pressing amount limiting member, which presses the
side of the sheet of papers, is arranged in a vicinity of at least
one of the multiple paper pressing members.
31. The paper conveying apparatus as claimed in claim 30, wherein
the vicinity is within a range in which the sheet of paper is
supported and pressed up by the multiple paper pressing members for
pressing the side of the sheet of paper.
32. The paper conveying apparatus as claimed in claim 28, wherein
the at least one pressing amount limiting member limits the
pressing amount by adjusting height thereof.
33. The paper conveying apparatus as claimed in claim 28, wherein
the at least one pressing amount limiting member is arranged
outside the side of the sheet of paper in the direction orthogonal
at the paper conveying direction in which the multiple paper
pressing members press the sheet of paper,
34. The paper conveying apparatus as claimed in claim 28, wherein
the at least one pressing amount limiting member is arranged
outside the multiple paper pressing member, which the press of the
sheet of paper, in the direction orthogonal to the paper conveying
direction.
35. The paper conveying apparatus as claimed in claim 28, wherein
the at least one pressing amount limiting member includes a first
pressing amount limiting part which is arranged outside the
multiple paper pressing member, which press the side of the sheet
of paper, in the direction orthogonal to the paper conveying
direction; and a second pressing amount limiting part which is
arranged below.
36. The paper conveying apparatus as claimed in claim 25, further
including: a print receiving member disposed opposing a print head
that prints on the sheet of paper; a conveyor roller configured to
convey the sheet of paper to the print receiving member; and a
pressing roller configured to press the sheet of paper on the
conveyor roller, wherein the multiple paper pressing members press
the sheet of paper on the print receiving member.
37. The paper conveying apparatus as claimed in claim 36, further
including one or more supporting member disposed on the print
receiving member.
38. An image forming apparatus comprising at least the paper
conveying apparatus of claim 25.
Description
TECHNICAL FIELD
[0001] The present invention relates to a paper conveying
apparatus, an image forming apparatus and an ink-jet recording
apparatus; more particularly to a paper conveying apparatus, an
image forming apparatus and an ink-jet recording apparatus that
have a print receiving member arranged opposed to a print head.
BACKGROUND ART
[0002] Conventionally, an ink-jet recording apparatus used as an
image recording apparatus (image forming apparatus) such as a
printer, a facsimile, a copier or the like can form an image on a
sheet of paper (not necessarily limited to paper but whatever is
used to form an image thereon) by ejecting ink droplets from a
nozzle of an ink-jet head thereto. Since deviation of the
positional relationship between the sheet of paper and the ink-jet
head may degrade image quality, it is required to convey the sheet
of paper with accuracy.
[0003] Since the ink-jet recording apparatus allows ink droplets to
adhere on a sheet of paper, the paper tends to become corrugated.
Namely, within a few seconds after the ink droplets adhere on the
paper, the paper swells and then becomes corrugated, which is known
as so-called cackling. Typically, when an image is printed on a
sheet of paper, there are margins formed on the right, left, top,
and bottom of the paper. Therefore, tensile stress is caused
between the right (left) margin and a printed area adjacent to the
right (left) margin, which pulls both the margins inward, thereby
causing both side portions of the paper to rise. If this happens,
the paper cannot be flat in relation to the ink-jet head, and a gap
between the paper and the ink-jet head varies, thereby distorting
the image. Moreover, a large corrugation of the paper causes a
problem in that the image printed on the paper may be defective and
the ink-jet head may be damaged or broken since the paper can
contact the ink-jet head.
[0004] In order to eliminate such disadvantages, an image forming
apparatus such as an ink-jet printer has been proposed in recent
years, where a conveyor roller is disposed in both the upstream and
the downstream end of a paper conveying direction so as to maintain
the flatness of the paper in relation to the ink-jet head. Such an
image forming apparatus can prevent the paper from becoming
corrugated during printing (See, patent-related publications listed
below).
[0005] [Patent-related document 1] Japanese Patent Application
Laid-Open Publication No. H7-125364.
[0006] [Patent-related document 2] Japanese Patent Application
Laid-Open Publication No. H7-132659.
[0007] [Patent-related document 3] Japanese Patent Application
Laid-Open Publication No. H9-24650.
[0008] [Patent-related document 4] Japanese Patent Application
Laid-Open Publication No. 2001-261188.
[0009] However, in such an ink jet recording apparatus where the
conveyor rollers are provided in the upstream and the downstream
end of the paper along the conveying direction, an image is printed
on the paper while the conveyer rollers are holding the leading and
the rear ends of the paper. Therefore, a relatively larger
non-printed zone has to be allocated at the upper and lower
portions of the paper (i.e., the leading margin and the rear
margin), which leads to another problem in that the printable area
becomes smaller.
[0010] The present invention has been made in view of the above,
and may provide a paper conveying apparatus, an image forming
apparatus and an ink-jet recording apparatus that can press side
portions of paper downward so as to allow the paper to bend
downward.
DISCLOSURE OF THE INVENTION
[0011] An embodiment of the present invention provides a paper
conveying apparatus including a first paper pressing member
configured to press one side portion of a sheet of paper that may
be conveyed therethrough, the side portion extending along a paper
conveying direction.
[0012] Another embodiment of the present invention provides the
paper conveying apparatus, where the first paper pressing member is
disposed so that a downstream portion thereof along the paper
conveying direction lies outward in a direction transverse to the
paper conveying direction from an upstream portion thereof.
[0013] Another embodiment of the present invention provides the
paper conveying apparatus, where the first paper pressing member is
disposed so that a center of a downstream portion thereof along the
paper conveying direction lies outward in a direction transverse to
the paper conveying direction from a center of an upstream portion
thereof.
[0014] Another embodiment of the present invention provides the
paper conveying apparatus, where the first paper pressing member is
disposed so that a center of a downstream portion thereof along the
paper conveying direction lies outward in a direction transverse to
the paper conveying direction from a corresponding one edge of the
sheet of paper.
[0015] Another embodiment of the present invention provides the
paper conveying apparatus, where the first paper pressing member is
disposed so that a middle portion thereof between a downstream
portion thereof and an upstream portion thereof along the paper
conveying direction lies outward from a corresponding one edge of
the sheet of paper.
[0016] Another embodiment of the present invention provides the
paper conveying apparatus, where the first paper pressing member
becomes narrower toward a downstream end thereof along the paper
conveying direction.
[0017] Another embodiment of the present invention provides the
paper conveying apparatus further including one or more supporting
members configured to support the sheet of paper from below.
[0018] Another embodiment of the present invention provides the
paper conveying apparatus further including a second paper pressing
member configured to press the other side portion of the sheet of
paper.
[0019] Another embodiment of the present invention provides the
paper conveying apparatus, where the second paper pressing member
is symmetric in shape with the first paper pressing member in
relation to the paper conveying direction.
[0020] Another embodiment of the present invention provides the
paper conveying apparatus, further including one or more third
paper pressing members capable of pressing the sheet of paper
between the first and the second paper pressing members.
[0021] Another embodiment of the present invention provides the
paper conveying apparatus, where the first or the second paper
pressing member presses one side portion of the sheet of paper and
one of the one or more third paper pressing members presses the
other side portion of the sheet of paper, and where the one of the
one or more third paper pressing members is disposed symmetrically
with the first or the second paper pressing member in relation to
the paper conveying direction.
[0022] Another embodiment of the present invention provides the
paper conveying apparatus further including one or more paper
pressing amount limiting members disposed below the sheet of paper
and configured to be substantially vertically movable so as to
limit an amount of pressing on the sheet of paper caused by the
first paper pressing member, the second paper pressing member, the
third paper pressing member, or a combination thereof.
[0023] Another embodiment of the present invention provides the
paper conveying apparatus further including one or more supporting
members configured to support the sheet of paper from below, where
the one or more paper pressing amount limiting members push from
below the sheet of paper that is held from below by the supporting
member and pressed from above by the first paper pressing member,
the second paper pressing member, the third paper pressing member,
or a combination thereof, so as to limit the amount of pressing
from above.
[0024] Another embodiment of the present invention provides the
paper conveying apparatus, wherein each of the one or more third
paper pressing members is disposed between every adjacent two of
the supporting members, and wherein one of the one or more
supporting members, the corresponding one of the one or more paper
pressing amount limiting members, and the corresponding one of the
one or more third paper pressing members are disposed in this order
in a direction transverse to the paper conveying direction.
[0025] Another embodiment of the present invention provides the
paper conveying apparatus, wherein each of the one or more third
paper pressing members is disposed between every adjacent two of
the supporting members, and wherein one of the one or more third
paper pressing members, the corresponding one of the one or more
supporting members, and the corresponding one of the one or more
paper pressing amount limiting members are disposed in this order
in a direction transverse to the paper conveying direction.
[0026] Another embodiment of the present invention provides the
paper conveying apparatus, where each of the one or more paper
pressing amount limiting members is disposed below a corresponding
one of the one or more third paper pressing members.
[0027] Another embodiment of the present invention provides the
paper conveying apparatus, where one of the one or more paper
pressing amount limiting members is disposed between the first
paper pressing member and the third paper pressing member adjacent
to the first paper pressing member.
[0028] Another embodiment of the present invention provides the
paper conveying apparatus, where one of the one or more paper
pressing amount limiting members is disposed between the second
paper pressing member and the third paper pressing member adjacent
to the second paper pressing member.
[0029] Another embodiment of the present invention provides the
paper conveying apparatus, where at least one of the one or more
paper pressing amount limiting members is disposed outward in a
direction transverse to the paper conveying direction from a
corresponding edge of the sheet of paper.
[0030] Another embodiment of the present invention provides the
paper conveying apparatus, where a first set of the one or more
paper pressing amount limiting members is disposed below the
corresponding third paper pressing members and where a second set
of the one or more paper pressing amount limiting members is
disposed between every adjacent two of the third paper pressing
members.
[0031] Another embodiment of the present invention provides the
paper conveying apparatus further including: a print receiving
member disposed opposing a print head that prints on the sheet of
paper; a conveying roller configured to convey the sheet of paper
to the print receiving member; and a pressing roller configured to
press the sheet of paper on the conveying roller, where at least
one of the first, the second, and the third paper pressing members
is configured to press the sheet of paper on the print receiving
member.
[0032] Another embodiment of the present invention provides the
paper conveying apparatus further including one or more supporting
members disposed on the print receiving member so as to support the
sheet of paper from below.
[0033] Another embodiment of the present invention provides an
image forming apparatus comprising at least the paper conveying
apparatus.
[0034] Another embodiment of the present invention provides an
ink-jet recording apparatus comprising at least the paper conveying
apparatus.
[0035] According to the embodiments of the present invention, there
is provided a paper conveying apparatus, an image forming apparatus
and an ink-jet recording apparatus that can press side portions of
paper downward so as to allow the paper to bend downward.
BRIEF DESCRIPTION OF THE DRAWINGS
[0036] FIG. 1 is a schematic cross-sectional view of an ink-jet
recording apparatus according to an embodiment of the present
invention.
[0037] FIG. 2 is a schematic perspective view of a print receiving
member and the vicinity thereof in the ink-jet recording apparatus
according to the embodiment of the present invention.
[0038] FIG. 3 is a plan view of the print receiving member of the
ink-jet recording apparatus according to the embodiment of the
present invention.
[0039] FIG. 4 is a front view of pressing members and the vicinity
thereof in the ink-jet recording apparatus according to the
embodiment of the present invention.
[0040] FIGS. 5(a) and 5(b) show other examples of the pressing
members having different shapes.
[0041] FIGS. 6(a) through 6(f) show still other examples of the
pressing members having different shapes.
[0042] FIGS. 7(a) through 7(d) show still other examples of the
pressing members having different shapes.
[0043] FIG. 8 is a plan view of the print receiving member in which
the pressing members are disposed differently from the pressing
members in FIG. 3.
[0044] FIGS. 9(a) through 9(c) are front views of the pressing
amount limiting members disposed in three respective positions in
relation to the pressing members.
[0045] FIG. 10 is a front view of the pressing amount limiting
members disposed outside the corresponding one of the pressing
members.
[0046] FIG. 11 is a plan view of the print receiving member in
which each of the pressing amount limiting members is disposed
outside the corresponding one of the pressing members.
[0047] FIG. 12 is a front view of the pressing amount limiting
members disposed below the corresponding pressing members.
[0048] FIG. 13 is a plan view of the print receiving member in
which the pressing amount limiting members are disposed below the
corresponding pressing members.
[0049] FIG. 14 is a front view for depicting that a sheet of paper
which has the edge thereof extending beyond the pressing member is
dealt with by the pressing members and the pressing amount limiting
members.
[0050] FIG. 15 is another front view of the pressing amount
limiting members disposed below the corresponding pressing members
except for the outmost (leftmost) pressing member.
[0051] FIG. 16 is another plan view of the print receiving member
in which the pressing amount limiting members disposed below the
corresponding pressing members except for the outmost (leftmost)
pressing member.
[0052] FIG. 17 is a front view of the pressing amount limiting
members are disposed inside the corresponding one of the pressing
members.
[0053] FIG. 18 is a plan view of the print receiving member in
which the pressing amount limiting members are disposed inside the
corresponding one of the pressing members.
[0054] FIG. 19 is another front view of the pressing amount
limiting members disposed inside the corresponding one of the
pressing members except for the outmost (leftmost) pressing
member.
[0055] FIG. 20 is another plan view of the print receiving member
in which the pressing amount limiting members are disposed inside
the corresponding one of the pressing members except for the
outmost (leftmost) pressing member.
[0056] FIGS. 21(a) and 21(b) are schematic side views for
explaining how the pressing members and the pressing amount
limiting member may function differently depending on the size of
the paper.
[0057] FIGS. 22(a) and 22(b) are schematic side views illustrating
that two pressing amount limiting members are arranged between the
pressing members.
BEST MODE FOR CARRYING OUT THE INVENTION
[0058] Referring to the accompanying drawings, a paper conveying
apparatus, an image forming apparatus and an ink jet recording
apparatus according to embodiments of the present invention are
described hereinafter. Since the following embodiments are
illustrated only as preferred embodiments of the present invention,
technologically preferable limitations are added thereto. However,
the present invention is not limited to the embodiments disclosed
herein unless a particular limitation is recited in the following
description.
[Ink-Jet Recording Apparatus]
[0059] FIG. 1 is a schematic cross-sectional view of an ink-jet
recording apparatus according to one embodiment of the present
invention. The recording apparatus houses a printing mechanism
portion 2 configured to have a carriage 13 movable along the main
scanning direction (perpendicular to the paper surface of FIG. 1)
in a recording apparatus body 1, a recording head 14 composed of an
ink-jet head mounted on the carriage 13, and an ink cartridge 15
configured to supply ink to the recording head 14, or the like. The
details thereof are described hereinafter.
[0060] In the lower portion of the recording apparatus body 1, a
paper feed cassette 4 into which plural sheets of paper 3 can be
placed from the front portion thereof is removably loaded. By the
way, the paper 3 can be fed from a paper feed tray (not shown)
instead of the paper feed cassette 4.
[0061] The paper 3 that has once been placed in the paper feed
cassette 4 is conveyed through a path defined by a paper feed
roller 21 and a friction pad 22 which can cooperatively separate
one sheet of paper 3 from other sheets of paper 3 in the paper feed
cassette 4, a conveyance roller 24 which reverses the direction of
the paper 3 conveyed from the paper feed cassette 4 to feed the
paper 3 forward, and a conveyance roller 26 that defines an
ejection angle of the paper 3 that has been ejected from the
conveyance roller 24 and an associated conveyance roller 25 that is
disposed pressed toward the circumferential surface of the
conveyance roller 24. Having traveled through this path, the paper
3 finally reaches the printing mechanism portion 2.
[0062] The printing mechanism portion 2 is composed of the carriage
13, the recording head 14, and the ink tank 15, or the like, and
functions to print the paper 3.
[0063] The carriage 13 is held by a main guide rod 11 and a sub
guide rod 12 supported by right and left side plates (not shown) so
as to slidably move in the main scanning direction (perpendicular
to the paper surface of FIG. 1).
[0064] The recording head 14 is mounted on the undersurface of the
carriage 13 so as to eject ink droplets downward. The recording
head 14 is composed of the ink-jet head having nozzles for ejecting
ink droplets of yellow (Y), cyan (C), magenta (M), and black (Bk).
By the way, the recording head 14 may be composed of plural heads
that are disposed side-by-side in the main scanning direction and
eject ink droplets of respective colors. In addition, the recording
head 14 may be composed of one head having nozzles capable of
ejecting ink droplets of corresponding colors.
[0065] Below the recording head 14, a print receiving member 27 is
arranged as a guide configured to guide the paper 3.
[0066] The ink tank (ink cartridge) 15 is configured to supply ink
of each color to the corresponding recording head 14. The ink tank
15 is replaceably mounted on the carriage 13.
[0067] On the paper 3 conveyed to the printing mechanism portion 2
is printed an image by the recording head 14, and then the paper 3
with the image thereon is further conveyed to a paper ejection tray
6 by a configuration described below.
[0068] Downstream from the print receiving member 27 along the
paper conveying direction (or along the rightward direction in FIG.
1), a conveyor roller 31 and a spur 32 are arranged for conveying
forward (or rightward) the paper 3. Additionally, downstream from
the conveyor roller 31 and the spur 32, guide members 35, 36 are
arranged so as to define a paper ejection path. Furthermore,
downstream therefrom, a paper ejection roller 33 and a spur 34 are
arranged for conveying the paper 3 toward the paper ejection tray
6.
[Print Receiving Member 27]
[0069] Referring to FIG. 2, the print receiving member 27 is
detailed hereinafter. FIG. 2 is a schematic perspective view of the
print receiving member 27 and the vicinity thereof in the ink-jet
recording apparatus 1 according to this embodiment of the present
invention. FIG. 3 is a plan view of the print receiving member 27
of the ink-jet recording apparatus 1 according to this embodiment
of the present invention. FIG. 4 is a front view of pressing
members 101, 102 and the vicinity thereof in the ink-jet recording
apparatus 1 according to this embodiment of the present
invention.
[0070] Referring to FIG. 2, the print receiving member 27 is
provided with plural ribs (supporting members) 29. The ribs 29 are
arranged so as to define a predetermined gap between the paper 3
and the recording head 14. As shown in FIG. 2, the outermost ribs
of the plural ribs 29 are positioned slightly inside the side edge
of the paper 3. Preferably, the distance between each of the
outermost ribs 29 and the corresponding side edge of the paper 3 is
less than or equal to 10 mm. More preferably, the distance
therebetween is less than or equal to 5 mm. An attachment portion
28 is provided with the plural pressing members 101, 102, which are
discussed in detail below.
[0071] The paper 3 conveyed to the print receiving member 27 is
pressed downward by the pressing members 101, 102 and conveyed on
and along the ribs 29 disposed on the print receiving member 27. In
this manner, a predetermined gap between the paper 3 and the print
head 14 is defined. Onto the paper 3 are adhered ink droplets
ejected from the print head 14 and thus a predetermined image is
formed thereon.
[0072] Among the plural pressing members 101, 102, the outermost
pressing members 101 (first and second paper pressing members) on
both sides can press respective side portions of the paper 3
downward. This allows the side portions of the paper 3 to be bent
downwardly in areas outside the outermost ribs 29 (see FIG. 4),
thereby preventing the side portions from rising. By the way, a
"side portion" here should be understood as being an area near the
paper edge extending along the paper conveying direction.
[0073] In addition, due to such bending of the paper 3 in both side
portions, the paper 3 can be maintained flat even between two
adjacent ribs, therefore maintaining constant the gap between the
paper 3 and the recording head 14. Moreover, the paper 3 is
prevented from contacting the recording head 14 even if the paper
swells after absorbing ink droplets, thereby preventing the image
thereon from being degraded and the recording head 14 from being
damaged.
[0074] As stated above, due to a simple configuration of the plural
ribs 29 disposed on the print receiving member 27 so as to oppose
the recording head 14, the pressing members 101 disposed so as to
press the side portions of the paper 3 downward, and the pressing
members 102 arranged between every two adjacent ribs in this
non-limiting embodiment, the paper 3 is prevented from contacting
the recording head 14.
[Pressing Member]
[0075] Next, the pressing members 101, 102 attached to the
attachment portion 28 are described in detail. Each of pressing
members 101, 102 according to this embodiment is attached to the
attachment portion 28 at the upstream side (or "A" side in FIG. 3)
of the print receiving member 27 and extends toward the downstream
side (or "B" side in FIG. 3), as shown in FIG. 3. Particularly, the
pressing members 101 are arranged outside the outmost ribs 29,
thereby preventing the side portions of the paper 3 from rising, as
described above.
[0076] In addition, since the pressing members 101 are arranged in
a symmetric relationship with each other as shown in FIG. 3, the
paper 3 is prevented from rising to a substantially equal degree in
both side portions.
[0077] By the way, when a paper having a smaller width than the
paper 3 illustrated in FIG. 3 is conveyed, other pressing members
(i.e., pressing members 102) positioned inside the pressing members
101 can press the side portions of the paper downward. For example,
the pressing members 102 (a third paper pressing member) can press
downward on the side portions of the paper illustrated by a dotted
line in FIG. 3. Therefore, the narrower paper can also be prevented
from rising upward in both side portions.
[0078] By the way, the pressing members 101, 102 shown in FIG. 3
are arranged symmetrically in relation to a central point of the
print receiving member 27, since the paper rests on the print
receiving member 27 so that the center of the paper coincides with
the central point of the receiving member 27. In contrast, the
pressing members 101, 102 may be arranged asymmetrically as shown
in FIG. 8, which is suitable when the paper is left-aligned.
Specifically, when the paper 3 shown by a dotted line in FIG. 8,
which is narrower than the paper 3 shown by a solid line, is
conveyed therein, the right edge of the narrower paper can be
pressed downward by either one of the pressing members 102.
[0079] FIGS. 5(a) and 5(b) show additional examples of the pressing
member 101 according to this embodiment of the present invention.
As shown in FIG. 5(a), the pressing member 101 has a distal point B
which is a downward point in the paper conveying direction. The
distal point B lies outward (leftward in FIG. 5(a)) and downstream
from a center point A on the upstream side of the pressing member
101.
[0080] Additionally, the distal point B is disposed outside the
edge (dotted line) of the paper. Moreover, not only the distal
point B but at least a portion on the downstream side thereof is
also disposed outside the edge of the paper.
[0081] As shown in FIG. 5(b), the pressing member 101 as the other
example has a distal point C that lies outward (leftward in FIG.
5(b)) and downstream from a corner point D on the upstream side
thereof.
[0082] FIGS. 6(a) through 6(f) show still other examples of the
pressing member 101. All the pressing members 101 illustrated
therein are disposed so as to press the left side portion of the
paper downward.
[0083] The pressing members 101 having such shapes as illustrated
in FIGS. 5(a), 5(b), and 6(a) through 6(f) can apply a greater
pressing force to the side portion of the paper as the paper
proceeds downward, thereby assuredly preventing the side portion of
the paper from rising upward.
[0084] Moreover, even when the side portion of the paper shifts
slightly in the direction transverse to the paper conveying
direction, the edge of the paper can touch the pressing member 101
and be pressed downward. Therefore, the side portion of the paper 3
can be bent downward by a weaker pressing force.
[0085] Furthermore, since the side portion of the paper, which is
easily bent or warped upward, can be pressed downward, the paper is
prevented from being contaminated or jammed.
[0086] In addition, since the pressing member 101 is narrower in
the downstream portion thereof than in the upstream portion
thereof, the pressing member 101 can press the side portion of the
paper downward with a weaker force, thereby allowing the paper to
be kept flat as a whole and thus providing a better quality image.
If the pressing force becomes too strong, the paper cannot be
maintained flat, since the stronger force may cause the paper to
drop between the ribs, which in turn makes it difficult to maintain
the paper flat in relation to the recording head 14 (FIG. 1).
[0087] Additionally, the outmost ribs 29, which are disposed near
the side portions of the paper, can help keep the paper flat,
thereby providing a better quality image. Moreover, since the
pressing members 101 are disposed outside the outmost ribs 29, the
pressing members 101 can prevent the side portion of the paper from
rising upward.
[0088] FIGS. 7(a) through 7(d) show various other examples of the
pressing members 101. Specifically, FIGS. 7(a) through 7(c) show
pressing members having identical widths along the paper conveying
direction, which are different from the pressing members 101
illustrated in FIGS. 5(a), 5(b), and FIGS. 6(a) through 6(f).
[0089] More specifically, as shown in FIG. 7(a), the pressing
member 101 is disposed so that a center point B at the rear (or
downstream) end thereof lies outside the paper edge whereas a
center point A at the front (or upstream) end thereof lies
substantially above the paper edge shown by a dotted line.
[0090] In FIG. 7(b), the pressing member 101 is disposed so that
the center point B at the rear (or downstream) end thereof lies
outside the paper edge whereas the center point A at the front (or
upstream) end thereof lies inside the paper edge.
[0091] In FIG. 7(c), the pressing member 101 is disposed so that
the center points A and B lie inside the paper edge. Although not
only the point A but also the point B lies inside the paper edge in
this case, at least a portion of the pressing member 101 can extend
outward from the paper edge. Therefore, this pressing member 101
can also press the paper edge downward.
[0092] In FIG. 7(d), the pressing member 101 has a rectangular
shape and is disposed so that both the center point B at the rear
(or downstream) end thereof and the center point A at the front (or
upstream) end thereof lie substantially above the paper edge.
[0093] Even these pressing members 101 illustrated in FIGS. 7(a)
through 7(d) can prevent the paper from rising upward evenly in
both side portions of the paper when the pressing members 101 are
disposed on both sides of the print receiving member 27. In
addition, such pressing members 101 can prevent the side portions
of the narrower paper from rising upward.
[Pressing Amount Limiting Member]
[0094] Next, a pressing amount limiting member according to one
embodiment of the present invention is described. In the foregoing
embodiments, the pressing members 101 press the paper outside the
outmost ribs 29 downward. In addition, since plural pressing
members 102 are disposed on the inner side of the pressing members
101, even when narrower paper is used, the paper can be bent
downward on both side portions (see FIG. 3).
[0095] However, the plural pressing members 102 may press the paper
downward to a greater extent between all adjacent ribs 29, which
may cause the paper, which has to be kept flat in relation to the
recording head 14, to be unnecessarily bent. In order to prevent
such unnecessary bending, a pressing amount limiting member 30 is
provided in this embodiment. That is, an amount of pressing on the
paper caused by the pressing members 102 can be adjusted by
adjusting the elevation of the pressing amount limiting member
30.
[0096] The pressing amount limiting member 30 is disposed on the
print receiving member 27. Specifically, the pressing amount
limiting member 30 may be disposed in three positions in relation
to the pressing members 101, 102 as shown in FIGS. 9(a) through
9(c), although the position cannot be strictly limited to the three
positions as long as the pressing amount limiting member 30 can
restrict the amount of pressing the paper 3 caused by the pressing
members 102.
[0097] In FIG. 9(a), the pressing amount limiting member 30 is
disposed outside (or on the left-hand side of) the pressing member
102 between the ribs 29. In FIG. 9(a), the pressing amount limiting
member 30 is disposed below the pressing member 102. In other
words, the pressing amount limiting member 30 is disposed so that a
portion of the paper pressed downward by the pressing member 102 is
held by the pressing amount limiting member 30. In FIG. 9(c), the
pressing amount limiting member 30 is disposed inside (or on the
right-hand side of) the pressing member 102 between the ribs 29.
The pressing amount limiting members 30 disposed as shown in FIGS.
9(a) through 9(c) are discussed in detail hereinafter.
[0098] First, the pressing amount limiting member 30 disposed
outside the pressing member 102 is described with reference to
FIGS. 9(a), 10, and 11. FIG. 10 is an explanatory view showing that
each of additional pressing amount limiting members 30 is disposed
outside the corresponding one of the pressing members 102. FIG. 11
is a plan view of the print receiving member 27 in which each of
the additional pressing amount limiting members 30 is disposed
outside the corresponding one of the pressing members 102. It
should be understood from FIGS. 10 and 11 that a rib 29, a pressing
amount limiting member 30, and a third paper pressing member 102
are disposed in this order in a direction from the side edge to the
center of the paper 3. The amount of pressing the paper 3 caused by
the pressing members 102 can be adjusted by adjusting the elevation
of the pressing amount limiting members 30 so disposed.
[0099] As shown in FIG. 10, the pressing amount limiting members 30
have a lower height (vertical length) than the ribs 29. In other
words, the pressing amount limiting members 30 are not required to
have a height higher than or equal to the ribs 29 because the
pressing amount limiting members 30 are not configured to adjust
the gap between the paper 3 and the recording head 14, whereas the
ribs 29 disposed on the print receiving member 27 are configured to
define the gap. In addition, the height of the pressing amount
limiting members 30 is not limited to a particular value as long as
the pressing amount limiting members 30 can limit the amount of
pressing the paper 3 caused by the pressing members 102.
[0100] Next, the pressing amount limiting member 30 disposed below
the pressing member 102 is described with reference to FIGS. 9(b),
and 12 through 16. FIG. 12 is another explanatory view showing that
additional pressing amount limiting members 30 are disposed below
the respective pressing members 102. FIG. 13 is a plan view of the
print receiving member 27 in which the additional pressing amount
limiting members 30 are disposed below the respective pressing
members 102. Additionally, FIG. 14 shows a situation where the
paper 3 is wider and the paper edge thereof extends beyond the
pressing member 101. The amount of pressing the paper 3 caused by
the pressing members 102 can be adjusted by adjusting the elevation
of the pressing amount limiting members 30 so disposed.
[0101] Although FIGS. 12 through 14 each shows an additional
pressing amount limiting member 30 disposed below the pressing
member 101, such a pressing amount limiting member 30 is not always
necessary as shown in FIGS. 15 and 16. Even in these cases, the
side portion of the paper 3 can be pressed downward by the pressing
member 101, and the paper 3 can be kept flat in relation to the
recording head 14 (FIG. 1) since the amount of pressing the paper 3
caused by the pressing members 102 can be limited by the pressing
amount limiting members 30 below the pressing members 102.
[0102] Then, the pressing amount limiting member 30 disposed inside
(or on the right-hand side of) the pressing member 102 is described
with reference to FIGS. 17 through 20 as well as FIG. 9(c). FIG. 17
is an explanatory view showing that each of the additional pressing
amount limiting members 30 is disposed inside the corresponding one
of the pressing members 102. FIG. 17 is a plan view of the print
receiving member 27 in which each of the additional pressing amount
limiting members 30 is disposed inside the corresponding one of the
pressing members 102. It should be understood from FIGS. 17 and 18
that a rib 29, a third pressing member 102, and a pressing amount
limiting member 30 are disposed in this order in a direction from
the side edge to the center of the paper 3. The amount of pressing
the paper 3 caused by the pressing members 102 can be adjusted by
adjusting the elevation of the pressing amount limiting members 30
so disposed.
[0103] Although FIGS. 17 and 18 show a pressing amount limiting
member 30 disposed between the pressing member 101 and the
outermost rib 29, such a pressing amount limiting member 30 is not
always necessary as shown in FIGS. 19 and 20. In these cases, the
pressing member 101 can press the side portion of the paper 3
downward. Besides, the amount of pressing the paper 3 caused by the
pressing members 102 can be limited by the pressing amount limiting
members 30 disposed inside the pressing members 102, so that the
paper 3 is kept flat in relation to the recording head 14.
[0104] Referring to FIGS. 21(a) and 21(b), it is next described how
the pressing members 101, 102 and the pressing amount limiting
member 30 may function differently depending on the size of the
paper 3.
[0105] FIG. 21(a) is an explanatory view showing how the pressing
amount limiting member 30 functions to limit the amount of pressing
the paper 3 caused by the pressing member 102 when a sheet of paper
3 larger than the paper which the pressing member 102 is supposed
to press downward is conveyed therein. In this case, the side
portion of the larger paper 3 is pressed downward by not the
pressing member 102 but the pressing member 101 in order to prevent
the side portion from rising; and the print area of the larger
paper 3 is kept flat in relation to the recording head 14 (FIG. 1)
by the pressing member 102 and the pressing amount limiting member
30 that limits the amount of pressing on the larger paper 3 caused
by the pressing member 102, thereby providing a better quality
image thereon.
[0106] On the other hand, when a sheet of paper 3 that is narrower
than the paper 3 illustrated in FIG. 21(a) is conveyed to the print
receiving member 27 (FIG. 11) as shown in FIG. 21(b), the narrower
paper 3 can be pressed downward by the pressing member 102. In this
case, a relatively large area of the side portion of the paper 3
may be pressed downward by the pressing member 102, since no image
is printed on the side portion.
[0107] In addition, it can be contemplated as other embodiments
according to the present invention that plural pressing amount
limiting members X are disposed outside the corresponding pressing
members 102 and plural pressing amount limiting members Y below the
corresponding pressing members 101, 102.
[0108] The pressing amount limiting members X function to limit the
amount of pressing the paper 3 caused by the associated pressing
members 102 when the edge of the paper 3 reaches the pressing
member 101 (see FIG. 22(a)). Thus, the paper 3 can be kept flat in
relation to the recording head 14 (FIG. 1) in an area in which the
pressing amount limiting member X limits the pressing amount, for
better print quality. In addition to the pressing amount limiting
members X, the pressing amount limiting members Y can demonstrate a
pressing amount limiting effect by adjusting the elevation thereof.
Therefore, the paper 3 can be kept flat in relation to the
recording head 14 (FIG. 1).
[0109] On the other hand, when a narrower paper whose edge does not
reach the pressing member 101 is conveyed therein, the pressing
amount limiting member Y disposed below the associated pressing
member 102 that presses the side portion of the paper 3 downward
can limit the amount of pressing the paper 3 caused by the pressing
member 102. In addition, adjusting the elevation of the pressing
amount limiting members (i.e., 30, X, Y) can reduce or increase the
limiting amount caused by the pressing members 102.
[0110] As stated above, according to this embodiment in which the
plural pressing amount limiting members 30, X, Y are provided, the
pressing amount limiting effect can be appropriately exhibited
depending on user needs.
[0111] By the way, the present invention is not limited to the
embodiments specifically disclosed herein, but various alterations
and modifications may be applied without departing from the scope
of the invention set forth in accompanying claims.
[0112] The present application is based on Japanese Patent
Applications No. 2006-146861, filed on May 26, 2006, and No.
2007-065640, filed on Mar. 14, 2007 with the Japanese Patent
Office, the entire contents of which are hereby incorporated by
reference.
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