Title: Ink-jet recording apparatus and maintenance method of ink-jet head included in ink-jet recording apparatus
Abstract: An ink-jet printer includes a belt conveyor mechanism, an ink-jet head having at its lower face a nozzle face where many nozzles are formed, and a maintenance unit that maintains the ink-jet head. Within the maintenance unit arranged are a blade, a wiping roller, an ink receiving member, and a purge cap, in this order from the near side to the head. The maintenance unit is first moved to a purge position at which the purge cap confronts the nozzle face of the ink-jet head, where a purge operation is performed. After the purge operation, attendant upon movement of the maintenance unit to get apart from the head, the ink receiving member, the wiping roller, and the blade successively confront the nozzle face in this order. With the movement of the maintenance unit, receiving ink with the ink receiving member and wiping ink up with the wiping roller and the blade are performed in order.
Patent Number: 6,866,361 Issued on 03/15/2005 to Kuki, et al.
| Inventors:
|
Kuki; Masakazu (Ichinomiya, JP);
Okamoto; Tsugio (Kani, JP)
|
| Assignee:
|
Brother Kogyo Kabushiki Kaisha (Nagoya, JP)
|
| Appl. No.:
|
674470 |
| Filed:
|
October 1, 2003 |
Foreign Application Priority Data
| Oct 02, 2002[JP] | 2002-289512 |
| Current U.S. Class: |
347/22; 347/33 |
| Intern'l Class: |
B41J 002//16.5 |
| Field of Search: |
347/22,29,30,32,33
|
References Cited [Referenced By]
U.S. Patent Documents
| 4951066 | Aug., 1990 | Terasawa et al.
| |
| 5202702 | Apr., 1993 | Terasawa et al. | 347/32.
|
| 5432539 | Jul., 1995 | Anderson.
| |
| 5793390 | Aug., 1998 | Claflin et al.
| |
| 5815176 | Sep., 1998 | Rotering | 347/33.
|
| 6123409 | Sep., 2000 | Wolf | 347/33.
|
| 6158839 | Dec., 2000 | Fukushima et al.
| |
| 6467873 | Oct., 2002 | Toba et al. | 347/33.
|
| 6619783 | Sep., 2003 | Kanaya et al. | 347/35.
|
| 6641248 | Nov., 2003 | Mitsui et al. | 347/29.
|
| 6679578 | Jan., 2004 | Arakawa | 347/33.
|
| 6692101 | Feb., 2004 | Lodal et al. | 347/33.
|
| 6742863 | Jun., 2004 | Takahashi | 347/33.
|
| 2002/0044168 | Apr., 2002 | Hashi et al.
| |
| Foreign Patent Documents |
| 0 314 513 | May., 1989 | EP.
| |
| B2 2626805 | Apr., 1997 | JP.
| |
| 11-309871 | Nov., 1999 | JP.
| |
| 11-342632 | Dec., 1999 | JP.
| |
Primary Examiner: Eickholt; Eugene H.
Attorney, Agent or Firm: Oliff & Berridge, PLC
Claims
What is claimed is:
1. An ink-jet recording apparatus comprising:
a medium conveyance mechanism that conveys a record medium;
an ink-jet head that has a nozzle face where a plurality of nozzles are
arranged, for ejecting ink through the nozzles onto the record medium
conveyed by the medium conveyance mechanism; and
a maintenance unit,
the maintenance unit comprising:
an ink receiving member in which a plurality of protrusions are arranged,
the protrusions being able to be brought into contact with ink adhering to
the nozzle face, for receiving the ink in a space between the protrusions;
a first wiping member that is able to be brought into contact with the
nozzle face to wipe up ink adhering to the nozzle face; and
a driving mechanism that moves the maintenance unit so that the ink
receiving member receives ink adhering to the nozzle face and then the
first wiping member wipes up ink adhering to the nozzle face.
2. The ink-jet recording apparatus according to claim 1, wherein the
maintenance unit further comprises a purge cap that sucks ink out of each
of the nozzles; and
the driving mechanism moves the maintenance unit so that the purge cap
sucks ink out of the nozzles, and then the ink receiving member receives
ink adhering to the nozzle face.
3. The ink-jet recording apparatus according to claim 2, wherein the medium
conveyance mechanism can shift between a conveyance position and a
non-conveyance position spaced apart from the nozzle face, and
the driving mechanism moves the maintenance unit so that the purge cap
confronts the nozzle face when the medium conveyance mechanism is in the
non-conveyance position.
4. The ink-jet recording apparatus according to claim 1, wherein the
driving mechanism moves the maintenance unit along a longitudinal
direction of the ink-jet head.
5. The ink-jet recording apparatus according to claim 1, wherein the
protrusions of the ink receiving member are thin plates arranged parallel
to each other, each thin plate being along a direction perpendicular to a
movement path of the maintenance unit.
6. The ink-jet recording apparatus according to claim 1, wherein the first
wiping member is made of a porous material capable of receiving ink.
7. The ink-jet recording apparatus according to claim 1, wherein the first
wiping member has a rotational axis parallel to the nozzle face and the
first wiping member is rotated with being in contact with the nozzle face
attendant upon movement of the maintenance unit.
8. The ink-jet recording apparatus according to claim 1, wherein the
maintenance unit further comprises a purge cap that sucks ink out of each
of the nozzles; and
the first wiping member is arranged on a side of the ink receiving member
opposite to the purge cap.
9. The ink-jet recording apparatus according to claim 1, wherein the
maintenance unit further comprises a second wiping member that is able to
be brought into contact with the nozzle face to wipe up ink adhering to
the nozzle face, and
the driving mechanism moves the maintenance unit so that the ink receiving
member receives ink adhering to the nozzle face, the first wiping member
wipes up ink adhering to the nozzle face, and then the second wiping
member wipes up ink adhering to the nozzle face.
10. The ink-jet recording apparatus according to claim 9, wherein the
second wiping member is a blade that scrapes ink off.
11. The ink-jet recording apparatus according to claim 10, wherein the
blade is made of a flexible material.
12. The ink-jet recording apparatus according to claim 9, wherein the
maintenance unit further comprises a purge cap that sucks ink out of each
of the nozzles; and
the first wiping member is arranged on a side of the ink receiving member
opposite to the purge cap, and
the second wiping member is arranged on a side of the first wiping member
opposite to the ink receiving member.
13. A maintenance method of an ink-jet head, the method comprising:
an ink receiving step for bringing ink adhering to a nozzle face on the
ink-jet head where a plurality of nozzles are arranged into contact with
protrusions arranged on an ink receiving member so as to receive the ink
in a space between the protrusions; and
a first wiping step for bringing a first wiping member into contact with
the nozzle face so as to wipe up ink adhering to the nozzle face with the
first wiping member, after the ink receiving step.
14. The maintenance method according to claim 13, wherein the first wiping
member absorbs therein ink adhering to the nozzle face.
15. The maintenance method according to claim 13, further comprising a
second wiping step for bringing a second wiping member into contact with
the nozzle face so as to wipe up ink adhering to the nozzle face with the
second wiping member, the second wiping step being performed after the
first wiping step.
16. The maintenance method according to claim 15, wherein the second wiping
member scrapes off ink adhering to the nozzle face.
17. The maintenance method according to claim 13, further comprising:
a cap arrangement step for arranging a purge cap that sucks ink out of each
nozzle so that the purge cap confronts the nozzle face; and
a purge step for sucking ink out of the nozzles,
the cap arrangement step and the purge step being performed before the ink
receiving step.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an ink-jet recording apparatus for
ejecting ink onto a record medium to print, and also to a maintenance
method of an ink-jet head included in the ink-jet recording apparatus.
2. Description of Related Art
In an ink-jet recording apparatus, a nozzle of an ink-jet head may be
clogged with ink to deteriorate the ink ejection performance, resulted
from generation of bubbles within the nozzle, entrance of dust into the
nozzle, an increase in viscosity of ink due to evaporation of an ink
solvent, etc. In order to avoid the trouble, in general, an ink-jet
recording apparatus includes therein a maintenance unit for removing the
above causes of the trouble from nozzles of an ink-jet head. For example,
U.S. Pat. No. 4,951,066 discloses a maintenance unit including a purge cap
for covering the nozzle face of an ink-jet head where nozzles are
arranged, to prevent the nozzles from being dried. The purge cap is
connected to a suction pump or the like to forcibly discharge ink. The
maintenance unit further includes a blade for cleaning the nozzle face,
and a rotatable porous member.
However, if a wiping operation with the blade is performed in a state
wherein a relatively large amount of ink has adhered to the nozzle face of
the head, ink may fly within the apparatus or may be collected on an edge
of the head. In this case, ink may adhere to a print paper or various
components within the apparatus. This brings about deterioration of the
print quality or a trouble of the mechanical operation.
On the other hand, any porous member has its limit in ink absorption
capacity. If the limit is exceeded, the cleaning effect decreases. In a
sliding operation of the porous member of the above-described prior art,
however, the limit of the ink absorption capacity is easily exceeded
because the operation is performed in a state wherein a relatively large
amount of ink has adhered to the nozzle face. There is a problem that the
cleaning effect is easy to decrease.
SUMMARY OF THE INVENTION
An object of the present invention is to provide an ink-jet recording
apparatus in which ink can be prevented from adhering to a print medium
and internal parts of the apparatus and ink adhering to a nozzle face can
be efficiently removed Upon maintenance of an ink-jet head, and also to
provide a maintenance method of an ink-jet head included in the ink-jet
recording apparatus.
According to an aspect of the present invention, an ink-jet recording
apparatus comprises a medium conveyance mechanism that conveys a record
medium; an ink-jet head that has a nozzle face where a plurality of
nozzles are arranged, for ejecting ink through the nozzles onto the record
medium conveyed by the medium conveyance mechanism; and a maintenance
unit. The maintenance unit comprises an ink receiving member in which a
plurality of protrusions are arranged. The protrusions can be brought into
contact with ink adhering to the nozzle face, for receiving the ink in a
space between the protrusions. The maintenance unit further comprises a
first wiping member that is able to be brought into contact with the
nozzle face to wipe up ink adhering to the nozzle face; and a driving
mechanism that moves the maintenance unit so that the ink receiving member
receives ink adhering to the nozzle face and then the first wiping member
wipes up ink adhering to the nozzle face.
According to another aspect of the present invention, a maintenance method
of an ink-jet head comprises an ink receiving step for bringing ink
adhering to a nozzle face on the ink-jet head where a plurality of nozzles
are arranged into contact with protrusions arranged on an ink receiving
member so as to receive the ink in a space between the protrusions; and a
first wiping step for bringing a first wiping member into contact with the
nozzle face so as to wipe up ink adhering to the nozzle face with the
first wiping member, after the ink receiving step.
According to the invention, upon maintenance of the ink-jet head, before
the first wiping member wipes up ink adhering to the nozzle face, the ink
receiving member receives and removes some part of the ink in advance
Thereby, ink can be efficiently removed. In addition, troubles can be
avoided in which ink flies within the apparatus and ink is collected on an
end portion of the ink-jet head, which troubles may arise in case that a
wiping operation with a blade is performed in a state wherein ink has
adhered to the nozzle face of the ink-jet head. Therefore, ink can be
prevented from adhering to a print medium or internal parts of the
apparatus.
BRIEF DESCRIPTION OF THE DRAWINGS
Other and further objects, features and advantages of the invention will
appear more fully from the following description taken in connection with
the accompanying drawings in which:
FIG. 1 is a front view of an ink-jet printer according to an embodiment of
the present invention;
FIG. 2 is a view of an ink-jet head, a belt conveyor mechanism, and a
maintenance unit, viewed from the left of FIG. 1;
FIG. 3 is a view illustrating a state wherein the maintenance unit of FIG.
2 starts to move from a withdrawal position toward a purge position after
the belt conveyor mechanism moves from a conveyance position to a
non-conveyance position;
FIG. 4 is an enlarged view illustrating a state wherein a purge step is
performed;
FIG. 5 is a view illustrating a state wherein a large amount of ink has
adhered to the lower face of the ink-jet head after the purge step is
completed:
FIG. 6 is a view illustrating a state wherein an ink receiving step with an
ink receiving member is performed;
FIG. 7 is a view illustrating a state wherein a first wiping step with a
wiping roller is performed while the maintenance unit further moves from
the state of FIG. 6 toward the withdrawal position;
FIG. 8 is a view illustrating a state wherein a second wiping step with a
blade is performed while the maintenance unit further moves from the state
of FIG. 7 toward the withdrawal position;
FIG. 9 is an upper view of the maintenance unit and a driving mechanism
included in the maintenance unit;
FIG. 10A is a view illustrating operations of parts of the maintenance unit
within a frame, in a state wherein the maintenance unit is at the
withdrawal position; and
FIG. 10B is a view illustrating operations of the parts of the maintenance
unit within the frame, in a state wherein the maintenance unit is at the
purge position.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
First, a general construction of an ink-jet printer as an ink-jet recording
apparatus according to an embodiment of the present invention will be
described with reference to FIG. 1. The ink-jet printer 1 of this
embodiment is a color ink-jet printer having four ink-jet heads 2. The
ink-jet printer 1 includes therein a paper feed unit 11 and a paper
discharge unit 12 in left and right portions of FIG. 1, respectively. A
paper conveyance path is formed extending from the paper feed unit 11 to
the paper discharge unit 12 within the ink-jet printer 1.
A pair of paper feed rollers 5a and 5b are disposed immediately downstream
of the paper feed unit 11 for putting forward a paper as a record medium
from the left to the right in FIG. 1. In the middle of the paper
conveyance path, a belt conveyor mechanism 13 as a medium conveyance
mechanism is provided. The belt conveyor mechanism 13 includes two belt
rollers 6 and 7 and a looped conveyor belt 8. The conveyor belt 8 is
wrapped around the belt rollers 6 and 7 to be stretched between them.
The conveyor belt 8 has a two-layered structure made up of a polyester base
body impregnated with urethane and a silicone rubber. The silicone rubber
is disposed in the outer portion of the conveyor belt 8 to form a conveyor
face. A paper fed through the pair of paper feed rollers 5a and 5b is kept
on the conveyor face of the conveyor belt 8 by adhesion, In this state,
the paper is conveyed downstream, i.e., rightward in FIG. 1, by driving
one belt roller 6 to rotate clockwise in FIG. 1 as indicated by an arrow
50.
Pressing members 9a and 9b are provided at positions for feeding a paper
onto the conveyor belt 8 and discharging the paper from the conveyor belt
8, respectively. Either of the pressing members 9a and 9b is for pressing
the paper onto the conveyor face of the conveyor belt 8 so as to prevent
the paper from separating from the conveyor face. Thus, the paper is
surely kept on the conveyor face.
A peeling device 10 is provided in the paper conveyance path immediately
downstream of the conveyor belt 8, i.e., on the right in FIG. 1. The
peeling device 10 peels off the paper, which is kept on the conveyor face
of the conveyor belt 8 by adhesion, from the conveyor face so that the
paper can be transferred toward the rightward paper discharge unit 12.
Each of the four ink-jet heads 2 has, at its lower end, a head main body
2a. Each head main body 2a has a rectangular section. The head main bodies
2a are arranged close to each other with the longitudinal direction of
each head main body 2a being perpendicular to the paper conveyance
direction, i.e., perpendicular to FIG. 1. That is, this printer 1 is a
line type printer. The bottom of each of the four head main bodies 2a
faces the paper conveyance path. In the bottom of each head main body 2a,
a large number of small-diameter nozzles are arranged though the nozzles
are not illustrated in FIG. 1. Hereinafter, the bottom face of each
ink-jet head 2 will be referred to as a nozzle face 2b. The four head main
bodies 2a eject ink of magenta, yellow, cyan, and black, respectively.
The head main bodies 2a are disposed such that a narrow clearance is formed
between each nozzle face 2b and the conveyor face of the conveyor belt 8.
The paper conveyance path is formed within the clearance. In this
construction, while a paper, which is being conveyed by the conveyor belt
8, passes immediately below the four head main bodies 2a in order, the
respective color inks are ejected through the corresponding nozzles toward
the upper face, i.e., the print face, of the paper to form a desired color
image on the paper.
The belt rollers 6 and 7 and the conveyor belt 8 are supported by a lifting
mechanism including a chassis 52. When a maintenance unit 20 as will be
described later is transversely moved, the belt rollers 6 and 7 and the
conveyor belt 8 are moved up or down by the lifting mechanism.
The chassis 52 of the lifting mechanism is put on a cylindrical member 53
disposed under the chassis 52. The cylindrical member 53 is rotatable
around a shaft 54 provided at a position deviating from the center of the
cylindrical member 53. Thus, by rotating the shaft 54, the level of the
uppermost portion of the cylindrical member 53 can be changed to move up
or down the chassis 52 accordingly. When the maintenance unit 20 is
transversely moved as will be described later, the cylindrical member 53
must have been rotated at an adequate angle in advance so as to move down
the chassis 52, the conveyor belt 8, and the belt rollers 6 and 7 by a
pertinent distance from the position illustrated in FIG. 1. A space for
the movement of the maintenance unit 20 is thereby ensured as illustrated
in FIG. 3.
In the region surrounded by the conveyor belt 8, a nearly rectangular
parallelepiped guide 51 having its width substantially equal to that of
the conveyor belt. 8 is disposed at an opposite position to the ink-jet
heads 2. The guide 51 is in contact with the lower face of the upper part
of the conveyor belt 8 to support the upper part of the conveyor belt 8
from the inside.
Next, the construction of a maintenance unit 20 provided in the ink-jet
printer 1 for maintaining the ink-jet heads 2 will be described with
reference to FIG. 2. FIG. 2 is a view of an ink-jet head, the belt
conveyor mechanism, and the maintenance unit, viewed from the left of FIG.
1. The maintenance unit 20 is disposed behind the belt conveyor mechanism
13 in FIG. 1.
The maintenance unit 20 includes a frame 21 movable transversely as will be
described later. Within the frame 21, a blade 43 as a second wiping
member, a wiping roller 41 as a first wiping member, an ink receiving
member 30, and purge caps 22 are disposed in this order from the side near
the ink-jet heads 2.
FIG. 2 illustrates only one purge cap 22. In the ink-jet printer 1,
however, four purge caps 22 are arranged perpendicularly to FIG. 2 as
illustrated in FIG. 9 so that the four purge caps 22 can cover the
respective nozzle faces 2b of the four ink-jet heads 2. Each purge cap 22
is made of an elastic material such as rubber. The purge cap 22 can be in
close contact with the nozzle face 2b of the corresponding ink-jet head 2
so as to hermetically cover the nozzle face 2b. Each purge cap 22 is
connected to a non-illustrated purge pump. The purge cap 22 and the purge
pump constitute a purge mechanism 23. A purge operation as will be
described later in detail is performed with the purge mechanism 23. The
purge pump may be mounted within the frame 21, or may be provided at an
adequate position outside the frame 21 within the apparatus.
Each purge cap 22 has two ink discharge ports 23a. Ink with dust or the
like having sucked by a purge operation as will be described later in
detail flows out through the ink discharge ports 23a and then it is
absorbed in a non-illustrated absorber disposed under the purge cap 22.
The ink is further introduced through a tube 60 into a waste ink reservoir
61 and absorbed and kept in an absorber 62 in the waste ink reservoir 61.
The ink receiving member 30 includes therein a plurality of thin plates 44
as protrusions each having a length somewhat larger than the total width
of the arranged four ink-jet heads 2. The thin plates 44 are arranged
parallel to each other so that each thin plate 44 is along an arrangement
direction of the ink-jet heads 2, i.e., perpendicularly to FIG. 2, to
include therein the total width of the ink-jet heads 2. The thin plates 44
confront each other in a longitudinal direction of each ink-jet head 2,
i.e., transversely in FIG. 2.
The wiping roller 41 is cylindrical. The wiping roller 41 is rotatably
supported on a shaft 40 parallel to each nozzle face 2b, more
specifically, along an arrangement direction of the ink-jet heads 2, i.e.,
perpendicular to FIG. 2. The wiping roller 41 has an axial length somewhat
larger than the total width of the arranged four ink-jet heads 2, like the
above-described thin plates 44. The wiping roller 41 is made of a porous
material such as urethane capable of absorbing ink.
The blade 43 has a length somewhat larger than the total width of the
arranged four ink-jet heads 2, like the above-described thin plates 44 and
wiping roller 41. The blade 43 is disposed along an arrangement direction
of the ink-jet heads 2, i.e., perpendicularly to FIG. 2. The blade 43 is
made of a flexible material such as rubber.
While the ink-jet printer 1 is not in a maintenance operation as will be
described later, the maintenance unit 20 stays at a withdrawal position,
i.e., a non-purge position, spaced apart from each ink-jet head 2, as
illustrated in FIG. 2. At this time, the upper end of each of the
components 22, 41, and 43 in the frame 21 except the ink receiving member
30 is at a level somewhat lower than the nozzle face 2b of the
corresponding ink-jet head 2 so that it can not come into contact with the
nozzle face 2b when the four purge caps 22 are transversely moved from the
withdrawal position to a purge position where each purge cap 22 confronts
the nozzle face 2b of the corresponding ink-jet head 2. The ink receiving
member 30 is, on the other hand, biased upward with a small force by a
compression spring, etc., and at the same time, this biasing force brings
guide portions formed at both ends of each thin plate 44 into contact with
both sides of the nozzle face 2b in the head holder 15 (see FIG. 1). With
this construction, a narrow clearance (e.g., 0.5 mm) may always be formed
between the upper end of the thin plate 44 and the nozzle face 2b of the
head 2.
The frame 21 is movable only transversely in FIG. 2 and its vertical level
is fixed. However, any of the components 22, 41, and 43 in the frame 21
except the ink receiving member 30 is vertically movable relatively to the
frame 21. Thus, upon a maintenance operation as will be described later,
the distance between each of the components 22, 41, and 43 in the frame 21
and the nozzle face 2b of the corresponding ink-jet head 2 can be
adequately changed. The ink receiving member 30 is, on the other hand,
immovable relatively to the frame 21 and still kept in a state in the
above-mentioned withdrawal position (a state where the narrow clearance
(e.g., 0.5 mm) is formed between the upper end of the thin plate 44 and
the nozzle face 2b), during the horizontal movement of the frame 21.
Next, a driving mechanism 75 for transversely moving the maintenance unit
20 will be described with reference to FIG. 9. FIG. 9 is an upper view of
the maintenance unit and the driving mechanism included in the maintenance
unit.
The driving mechanism 75 included in the maintenance unit 20 has an
electric motor 70, a motor pulley 70a, an idle pulley 70b, a timing belt
71, and guide shafts 72a and 72b. The motor 70 is attached to a main frame
58a in the right of FIG. 9 with screws or the like. The motor pulley 70a
is connected to the motor 70 to rotate with the drive of the motor 70. The
idle pulley 70b is rotatably supported by a main frame 58c in the left of
FIG. 9. The timing belt 71 is wrapped around the motor pulley 70a and the
idle pulley 70b in a pair to be stretched between them. The timing belt 71
is connected to a bearing 21a protruding beyond both sides in the width of
the frame 21. Each of the guide shafts 72a and 72b is fixed to the left
and right main frames 58a and 58c with screws or the like to extend
between the frames 58a and 58c parallel to the timing belt 71. The guide
shafts 72a and 72b support both sides in the width of the maintenance unit
20 through the bearing 21a and so on.
In this construction, when the motor 70 is driven, the motor pulley 70a is
rotated clockwise or counterclockwise to run the timing belt 71. With the
run of the timing belt 71, the maintenance unit 20 connected to the timing
belt 71 through the bearing 21a is moved in the left or right direction in
FIG. 9, i.e., toward the purge or withdrawal position.
Next, a more detailed configuration of each member 22, 30, 41, and 43
included in the maintenance unit 20 and a vertical movement of each member
22, 41, and 43 in the frame 21 except the ink receiving member 30 will be
described with reference to FIGS. 10A and 10B. The below-described
vertical movement of each member 22, 41, and 43 in the frame 21 except the
ink receiving member 30 is also realized by the driving mechanism 75
illustrated in FIG. 9.
The frame 21 receiving therein the maintenance unit 20 includes a cap plate
25 disposed inside the frame 21 to correspond to the purge caps 22.
The four purge caps 22 are supported in the manner that shafts 22a are
inserted in cam holes 25b formed in the cap plate 25. The shafts 22a are
inserted also in grooves 21b formed in the frame 21.
The ink receiving member 30 is supported by the frame 21 through a shaft
30a. A plate 42 supporting the wiping roller 41 and the blade 43 is
attached to the frame 21 through a shaft 42a. Cam holes 42b are formed in
the plate 42. An operating shaft 45 moving vertically the wiping roller 41
and the blade 43 is inserted in the cam holes 42b and fan-shaped holes 21c
formed in the frame 21.
When the maintenance unit 20 is moved rightward in FIG. 10A, i.e., toward
the ink-jet heads 2 in FIG. 2, a protrusion. 25a provided on the cap plate
25 is brought into contact with a non-illustrated projection provided
below a head holder 15 (see FIG. 1) immediately before the maintenance
unit 20 reaches the purge position (see FIG. 4). The components of the
maintenance unit 20 other than the cap plate 25 are further moved
rightward in FIG. 10A in a state wherein the movement of the cap plate 25
is stopped by the projection. As the frame 21 is moved, the shaft 22a
inserted in the grooves 21b formed in the frame 21 is moved in an upper
direction along the cam holes 25b, as illustrated in FIG. 10B. The purge
caps 22 are elevated with the movement of the shaft 22a so that the upper
ends of the purge caps 22 is in close contact with the nozzle faces 2b of
the ink-jet heads 2 when the maintenance unit 20 is at the purge position.
The purge caps 22 are biased upward by a non-illustrated spring, and
therefore pushed against the nozzle faces 2b by the pressure from the
springs. When the maintenance unit 20 reaches the purge position, the
shaft 22a is stopped by the upper right ends of the cam holes 25b to stop
the movement of the whole of the maintenance unit 20 including the frame
21.
On the other hand, substantially at the same time when the protrusion 25a
provided on the cap plate 25 is brought into contact with the projection
provided below the head holder 15, the operating shaft 45 moving
vertically the wiping roller 41 and the blade 43 is brought into contact
with metallic parts 55 provided on the left main frame 58a of FIG. 9. The
frame 21, etc., is further moved rightward in FIG. 10A in a state wherein
the metallic parts 55 stop the movement of the operating shaft 45.
Thereby, the operating shaft 45 inserted in both of the cam holes 42b and
the fan-shaped holes 21c is moved leftward in FIG. 10A relatively to the
frame 21, as illustrated in FIG. 10B. With the movement of the operating
shaft 45, the plate 42 supporting the wiping roller 41 and the blade 43 is
rotated counterclockwise around the shaft 42a. At this time, the ink
receiving member 30 does not move. Accordingly, when the maintenance unit
20 is at the purge position, the thin plates 44 provided in the ink
receiving member 30 are set at positions with the narrow clearance (e.g.,
0.5 mm) being formed between the upper ends thereof and the nozzle faces
2b. The upper end of the wiping roller 41 is set substantially at the same
level as that of the nozzle faces 2b. The tip end of the blade 43 is set
at a level somewhat higher than that of the nozzle faces 2b so that the
blade 43 is bent when it is brought into contact with the nozzle faces 2b.
After a purge operation as will be described later is performed at the
purge position, the maintenance unit 20 starts to move leftward in FIG.
10B toward the withdrawal position, i.e., in the direction to get apart
from the ink-jet heads 2 in FIG. 2. Immediately after this, the engagement
between the protrusion 25a of the cap plate 25 and the non-illustrated
projection provided below the head holder 15 is relieved. The cap plate 25
including the cam holes 25b is biased leftward in FIG. 10B by a
non-illustrated spring. Therefore, the cap plate 25 moves leftward and the
shaft 22a moves along the cam holes 25b. Thereby, the purge cap 22 is
moved down to return to the same state as that when the maintenance unit
20 is at the withdrawal position as illustrated in FIG. 10A.
Contrastingly, even after the engagement between the protrusion 25a and the
projection provided below the head holder 15 is relieved, the wiping
roller 41 and the blade 43 are kept in the state of FIG. 10B. This is
because the operating shaft 45 supporting the wiping roller 41 and the
blade 43 is biased upward by a non-illustrated spring in a state wherein
the operating shaft 45 is pushed leftward in the cam holes 42b formed in
the plate 42. Afterward, the maintenance unit 20 is further moved toward
the withdrawal position. Immediately before the maintenance unit 20
reaches the withdrawal position, the operating shaft 45 is brought into
contact with metallic parts 56 provided on the central main frame 58b of
FIG. 9. The frame 21, etc., is further moved leftward in FIG. 10B in a
state wherein the metallic parts stop the movement of the operating shaft
45. Thereby, the operating shaft 45 inserted in the cam holes 42b and the
fan-shaped holes 21c is moved rightward in FIG. 10B. The state of FIG. 10A
where the wiping roller 41 and the blade 43 have been moved down is
obtained at the same time when the maintenance unit 20 reaches the
withdrawal position.
Next, a maintenance method of the ink-jet heads 2 with the maintenance unit
20 will be described. Maintenance with the maintenance unit 20 is
performed, for example, when ink is introduced into the ink-jet heads 2
from a ink supply source, i.e., a non-illustrated ink cartridge, upon the
first use of the printer 1, when the printer 1 is used after it is not
used for a predetermined time, or when printing on a predetermined number
of papers is completed.
In FIGS. 3 to 8 that will be referred to hereinafter, the tube 60, the
waste ink reservoir 61, and the absorber 62 of FIG. 2 are omitted.
When maintenance of the ink-jet heads 2 with the maintenance unit is
performed, the belt conveyor mechanism 13 has been beforehand moved, by
the above-described lifting mechanism, to a lower non-conveyance position
that is spaced apart from the nozzle faces 2b. In this state, the
maintenance unit 20 is transversely moved by the above-described driving
mechanism of FIG. 9 from the withdrawal position to the right in FIG. 3
toward the ink-jet heads 2 so as to enter the space between the ink-jet
heads 2 and the belt conveyor mechanism 13.
The maintenance unit 20 is then disposed at the purge position (a cap
disposition step). In this step, as described above, each purge cap 22 is
elevated so that its upper end is in close contact with the corresponding
nozzle face 2b, and simultaneously with this, each of the wiping roller 41
and the blade 43 is moved relatively to the frame 21 so that its upper end
is at a predetermined level relative to the nozzle faces 2b (see FIG. 4).
The maintenance unit 20 is once stopped at the purge position, where a
purge operation with the purge caps 22 is performed (a purge step). To
perform the purge operation, in a state wherein each purge cap 22 covers
the nozzle face 2b of the corresponding ink-jet head 2 as illustrated in
FIG. 4, the above-described non-illustrated purge pump is driven to apply
suction force to each nozzle. As a result, ink containing dust or bubbles
or ink having increased in viscosity is sucked out of the nozzle, and ink
passages provided within each ink-jet head 2 are filled up with ink from
an ink cartridge. The sucked-out ink is discharged into the waste ink
reservoir 61 of FIG. 2, as described above.
When the maintenance unit 20 starts to move to the left in FIG. 4 toward
the withdrawal position after the purge step is completed, each purge cap
22 is moved down so that its upper end is at a level somewhat lower than
that of the nozzle face 2b of the corresponding ink-jet head 2, as
illustrated in FIG. 5. As a result, the nozzle face 2b of each ink-jet
head 2 that was covered with the corresponding purge cap 22 is exposed. As
illustrated in FIG. 5, droplets of ink sucked out of nozzles may adhere to
the nozzle faces 2b of the ink-jet heads 2.
At this time, any of the ink receiving member 30, the wiping roller 41, and
the blade 43 is kept in the state of FIG. 4, as described above.
Afterward, the maintenance unit 20 is further moved toward the withdrawal
position. In this movement, the ink receiving member 30, the wiping roller
41, and the blade 43 confront the nozzle faces 2b of the ink-jet heads 2
in order. An ink receiving step, a first wiping step, and a second wiping
step are performed with the respective components.
FIG. 6 is a view illustrating a state wherein an receiving step with the
ink receiving member 30 is performed. In this step, the upper end of each
thin plate 44 in the ink receiving member 30 is not in contact with the
nozzle faces 2b of the ink-jet heads 2 but at a predetermined small
distance (e.g., 0.5 mm) from the nozzle faces 2b. In this state wherein
the thin plates 44 arranged adjacently in parallel with each other within
the ink receiving member 30 are not in contact with the nozzle faces 2b of
the ink-jet heads 2, relatively large droplets of ink adhering to the
nozzle faces 2b are brought into contact with the thin plates 44. Thereby,
those large droplets are transferred into spaces between the thin plates
44 (an ink receiving step).
FIG. 7 is a view illustrating a state wherein a first wiping step with the
wiping roller 41 is performed while the maintenance unit 20 is further
moved from the state of FIG. 6 toward the withdrawal position. As
described above, the wiping roller 41 is pushed against the nozzle faces
2b with a small force. Therefore, when the wiping roller 41 confronts the
nozzle faces 2b, the wiping roller 41 is brought into contact with the
nozzle faces 2b. Further, the wiping roller 41 is rotatably supported on
the shaft 41. Therefore, the wiping roller 42 in contact with the nozzle
faces 2b is rotated counterclockwise as shown with an arrow in FIG. 7,
attendant upon the movement of the maintenance unit 20. Thus, small
droplets of ink adhering to the nozzle faces 2b, which have not been
removed by the ink receiving member 30, are wiped off (a first wiping
step). Because the wiping roller 41 is made of a porous material capable
of absorbing ink, as described above, the wiped-off ink is absorbed from
the surface to the inside of the wiping roller 41.
FIG. 8 is a view illustrating a state wherein a second wiping step with the
blade 43 is performed while the maintenance unit 20 is further moved from
the state of FIG. 7 toward the withdrawal position. As described above,
the upper end of the blade 43 is at a level somewhat higher than that of
the nozzle faces 2b. Therefore, when the blade 43 confronts the nozzle
faces 2b, the blade 43 is brought into contact with the nozzle faces 2b
with being bent. Thus, the blade 43 scrapes off ink adhering to the nozzle
faces 2b. Thereby, smaller droplets of ink adhering to the nozzle faces
2b, which have not been removed even by the wiping roller 41, are wiped
off (a second wiping step).
As described above, in the ink-jet printer 1 of this embodiment, upon
maintenance of the ink-jet heads 2, before the wiping roller 41 wipes up
ink adhering to the nozzle faces 2b, the ink receiving member 30 receives
and removes some part of the ink in advance. Thereby, ink can be
efficiently removed. In addition, troubles can be avoided in which ink
flies within the apparatus and ink is collected on an end portion of each
ink-jet head 2, which troubles may arise in case that a wiping operation
with the blade 43 is performed in a state wherein ink has adhered to the
nozzle faces 2b of the ink-jet heads 2. Therefore, ink can be prevented
from adhering to a print paper or internal parts of the apparatus.
Since the maintenance unit of this embodiment includes the purge caps for
sucking ink out of the nozzles, an ink receiving operation with the ink
receiving member 30 is performed after a purge operation. Large droplets
of ink are apt to adhere to the nozzle faces in particular after the purge
operation. In this case, by receiving and removing some of ink with the
ink receiving member 30 in advance before wiping with the wiping roller 41
or blade 43, the above-described effect that ink is prevented from
adhering to a print paper or internal parts of the apparatus, can be
obtained more effectively.
The driving mechanism 75 of FIG. 9 dives the maintenance unit 20 to move
between the withdrawal and purge positions synchronously with the movement
of the belt conveyor mechanism 13 between the conveyance and
non-conveyance positions. This is a suitable construction for the line
type printer 1 of the above-described embodiment.
The maintenance unit 20 is moved along the longitudinal direction of each
ink-jet head 2, i.e., transversely in FIG. 2. This can avoid problems in
which inks of different colors are mixed with each other and ink is apt to
be collected on a side face in the width of each ink-jet head 2, which
problems may arise in case that the maintenance unit 20 is moved along the
width of each ink-jet head 2, i.e., transversely in FIG. 1.
The plural thin plates 44 included in the ink receiving member 30 are
arranged in parallel with each other perpendicularly to the movement path
of the maintenance unit 20. In this relatively simple structure, ink
adhering to the nozzle faces 2b can be received in the space between the
thin plates 44 and thereby the ink can be efficiently removed.
The wiping roller 41 is made of a porous material and absorbs ink adhering
to the nozzle faces 2b, in the first wiping step. Therefore, a large
amount of ink does not stay on the surface of the roller 41. Thus,
efficient ink removal can be performed.
The wiping roller 41 is rotatable around the shaft 40 parallel to the
nozzle faces 2b. In the first wiping step, the wiping roller 41 is rotated
with being in contact with the nozzle faces 2b, attendant upon the
movement of the maintenance unit 20. Further, this wiping roller 41 can
perform an efficient ink removal because the rotation brings relatively
less dirty part of the surface of the wiping roller 41 into contact with
the nozzle faces of the ink-jet heads 2.
The wiping roller 41 is disposed on the side of the ink receiving member 30
opposite to the purge caps 22. This makes it easy to move the maintenance
unit 20 so that the purge step with the purge caps 22, the ink receiving
step with the ink receiving member 30, and the first wiping step with the
wiping roller 41 are performed in this order. Further, the blade 43 is
disposed on the side of the wiping roller 41 opposite to the ink receiving
member 30. This makes it easy to move the maintenance unit 20 so that the
purge step, the ink receiving step, the first wiping step, and the second
wiping step with the blade 43 are performed in this order.
The maintenance unit 20 further includes the blade 43 and the second wiping
step with the blade 43 is performed after the first wiping step with the
wiping roller 41. Therefore, ink can be removed more efficiently and any
part of the ink can be prevented from remaining after wiping, and at the
same time, the ink meniscus can be maintained in a normal state. In
particular, if wiping with the blade 43 is performed in a state wherein a
large amount of ink has adhered to the nozzle faces 2b, ink may fly within
the apparatus or ink may be collected on end portions of the ink-jet
heads. In this embodiment, however, those problems can be relieved because
the wiping roller 41 already removed some part of ink when wiping with the
blade 43 is performed.
The blade 43 is for scraping off ink adhering to the nozzle faces 43.
Therefore, ink remaining even after wiping with the wiping roller 41 can
be effectively scraped off to be removed from the nozzle faces 2b.
The blade 43 is made of a flexible material. Therefore, it can come into
close contact with the nozzle faces 2b without any gap with being bent as
illustrated in FIG. 8. Thus, an ink wiping operation can be efficiently
performed and this prevents any part of ink from remaining,
The blade 43 may not be made of such a flexible material if it can wipe ink
up. Further, the means used in the second 6 wiping step is not limited to
a member capable of scraping ink off, such as the blade 43. The second
wiping step Can be performed using any adequate member capable of wiping
ink up.
Further, within the maintenance unit 20, the blade 43, the wiping roller
41, the ink receiving member 30, and the purge caps 22 may not always be
arranged in this order. That is, irrespective of the arrangement of the
components, the maintenance unit 20 may be moved so that the purge step,
the ink receiving step, the first wiping step, and the second wiping step
are performed in this order.
Further, the second wiping step with the blade 43 or the like may not be
performed, In this case, after the ink receiving step with the ink
receiving member 30, only the first wiping step with the wiping roller 41
is performed.
Further, the member used in the first wiping step is not limited to the
wiping roller 41 that has the shaft 40 and can be rotated with being in
contact with the nozzle faces 2b. Various other members are usable if it
can be in contact with the nozzle faces 2b to wipe up ink adhering to the
nozzle faces 2b. In addition, the member used in this step may not be made
of such a porous material capable of absorbing ink.
Further, the arrangement of the plural thin plates 44 within the ink
receiving member 30 is not limited to that perpendicular to the movement
path of the maintenance unit 20. In addition, the thin plates 44 may
confront each other in a direction not along the movement path of the
maintenance unit 20. Further, the ink receiving member 30 is not limited
to the above construction including the plural thin plates 44. For
example, the ink receiving member 30 may include a large number of
standing needles like a frog. Otherwise, the ink receiving member 30 may
include a large number of needlelike members each having its tip end
branching into a Y shape to improve the ink receiving performance.
Further, each gap between protrusions within the ink receiving member 30
can be connected to an adequate absorption means to increase the ink
receiving capacity of the ink receiving member 30. As this absorption
means, the above-described purge pump can be used. That is, the purge pump
may be connected also to the ink receiving member 30, This makes the
construction simple.
Further, the maintenance unit 20 may be moved not along the longitudinal
direction of each ink-jet head 2 but along the width of each ink-jet head
2, i.e., transversely in FIG. 1.
Further, the belt conveyor mechanism may not be movable between the
conveyance and non-conveyance positions. It may be fixed. Further, not the
maintenance unit 20 but the ink-jet heads 2 may be moved for maintenance.
This may be suitable for a serial-type printer in which printing is
performed with moving a print paper and reciprocating a head main body
perpendicularly to the movement of the print paper, different from a line
type printer as that of the above-described embodiment in which printing
is performed with moving a print paper relatively to the fixed ink-jet
heads 2. That is, the present invention is not limited to a line type
printer and it is applicable also to a serial-type printer.
Further, the present invention is not limited to an ink-jet printer and it
is applicable also to an ink-jet type facsimile or copying machine.
While this invention has been described in conjunction with the specific
embodiments outlined above, it is evident that many alternatives,
modifications and variations will be apparent to those skilled in the art.
Accordingly, the preferred embodiments of the invention as set forth above
are intended to be illustrative, not limiting. Various changes may be made
without departing from the spirit and scope of the invention as defined in
the following claims.
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