JPH09109403A - Ink jet recording apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To miniaturize an ink jet recording apparatus by contracting the retreat space of a cap to the utmpost. SOLUTION: A cap part 32 consists of caps 37Y, 37M, 37C, 37B and the endless wires 38, 38 arranged on both outsides of a head unit. Each of the caps is set so that the closing surface thereof is arranged in the direction crossing the nozzle surface of the head unit at a right angle and supported so as to be revolvable centering around the rotary shaft extending in the lateral direction of paper. One ends of the endless wires 38 are fixed to both side surfaces of each cap in the lateral direction of the paper by rivets and the other ends of these wires are respectively fixed to the endless wires 38. The endless wires 38, 38 are trained over a drive roller 42 and a follower roller 43 under tension.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording apparatus applied to a facsimile, a copying machine, a printer and the like.

[0002]

2. Description of the Related Art In recent years, an ink jet recording apparatus for printing on paper by ejecting ink droplets from a plurality of nozzles arranged in a recording head has been put to practical use. This device is
Fill the pressurized chamber communicating with the micro nozzle with ink,
The ink droplets are ejected outward from the nozzle by driving the pressurizing chamber under pressure during printing. Therefore, since the ink in the nozzle is exposed to the outside air, there is a possibility that the nozzle may be clogged due to the drying of the ink, especially during the pause period when the printing operation is not performed. Therefore, during the pause period, the nozzle surface of the recording head is covered with a cap to prevent the ink from drying.

[0003]

Since it is necessary to uniformly cap the nozzle surface of the recording head, the cap has at least the same area as the nozzle surface, and the printing operation is performed during the printing operation. In order to secure it, it is necessary to retreat from the nozzle surface. Therefore, the device body
A retractable space for the cap must be provided separately, which leads to an increase in the size of the device. In particular, it becomes more noticeable when the recording head is a line head or a large type such as an integrated type for a plurality of colors.

Further, since the nozzle surface of the recording head is arranged at a printing position with a minute distance from the recording medium during printing, when capping, the recording head extends from the printing position to the cap arranged in the retreat space. I had to move and the capping time was long.

An object of the present invention is to solve the above problems, and an object thereof is to provide an ink jet recording apparatus capable of reducing the size of the apparatus by reducing the retracting space of the cap as much as possible.

Another object of the present invention is to provide an ink jet recording apparatus which shortens the time required for capping.

[0007]

According to the present invention, there is provided a recording head in which nozzles for ejecting ink are formed in an array on a surface facing a recording sheet, and a cap which is in close contact with the recording head and closes the nozzle surface. A cap support means for movably supporting the cap between a closed position for closing the nozzle surface and a spaced position opposed to a side surface parallel to the nozzle arrangement direction of the recording head; and a closed surface of the cap for the nozzle. And a cap moving means for moving the cap to the separated position in a direction orthogonal to the surface (claim 1).

According to this structure, the cap is moved to the separated position facing the side surface parallel to the nozzle arrangement direction of the recording head in a direction in which the closed surface is orthogonal to the nozzle surface of the recording head, The space occupied by the cap does not increase as in the case where the surface and the closed surface are parallel.

Further, in the ink jet recording apparatus according to claim 1, the recording is performed between a print position where the nozzle surface of the recording head is separated from the paper surface of the recording paper by a minute distance and a retracted position retracted from the print position. A head supporting means for movably supporting the head and a head moving means for moving the recording head between the printing position and the retracted position are provided, and the cap moving means is the cap located at the separated position. Is moved to close the nozzle surface of the recording head located at the retracted position with the cap (claim 2).

According to this structure, when printing is performed,
The recording head is moved to a print position where the nozzle surface is separated from the surface of the recording paper by a minute distance, and the cap is moved to the separated position. On the other hand, when printing is not performed, the recording head is moved to the retracted position retracted from the printing position, the cap is moved from the separated position, and the nozzle surface of the recording head in the retracted position is blocked by the cap.

Further, the cap moving means rotates the cap about a rotation axis parallel to the nozzle arrangement direction (claim 3).

According to this structure, the cap rotates about the rotation axis parallel to the nozzle arrangement direction from the separated position,
The nozzle surface of the recording head in the retracted position is closed by the cap.

[0013]

FIG. 3 is a front view showing the internal construction of an embodiment of an ink jet recording apparatus according to the present invention.

As shown in FIG. 3, this apparatus has a sheet feeding cassette 11 arranged at the lower portion of the apparatus, an ink tank 12 arranged above the sheet feeding cassette 11, and an endless section arranged above the ink tank 12. A belt 13, a printing unit 14 disposed above the endless belt 13, and a sheet conveyance path 15 disposed at the right end of the apparatus are provided.

The paper feed cassette 11 is for accommodating recording paper on which printing is to be performed. In the paper feed cassette 11, a paper feed roller 21 for feeding paper is arranged at the end portion on the paper transport path 15 side. It is set up. The paper feed path 15 is composed of a guide plate that guides the recording paper fed from the paper feed cassette 11 to the endless belt 13. In this paper transport path 15, a transport roller pair 22 that transports the fed paper is disposed on the paper feed cassette 11 side, and a registration roller pair 23 that performs secondary paper feed is disposed on the endless belt 13 side. ing.

The endless belt 13 is stretched over a pair of conveying rollers 24 and conveying rollers 25 arranged on both the left and right outer sides of the printing unit 14, and the recording paper secondarily fed by the registration roller pair 23 is left. It is to be transported toward.
A discharge roller pair 26 is disposed on the left side of the endless belt 13, and a discharge port 27 is formed on the left side wall of the device on the left side of the discharge roller pair 26. A discharge tray 28 that projects to the front is provided.

The ink tank 12 is composed of ink tanks 12Y, 12M, 12C and 12B arranged side by side in the left and right direction, and stores yellow, magenta, cyan and black inks, respectively. The printing unit 14
Includes a recording head 31 and a cap portion 32.

FIG. 1 is a diagram showing the construction of the printing unit 14,
(A) is a plan view and (b) is a front view. FIG. 2 is a partial perspective view of the cap portion 32. The recording head 31
Is a unit holding portion 33 and head units 34Y and 3Y vertically arranged side by side in the unit holding portion 33.
It is composed of 4M, 34C and 34B.

Bearings 331 and 332 are provided at the left and right ends of the unit holding portion 33. Bearing part 332
A head raising / lowering motor 35 is supported by the apparatus main body above, and a male screw is formed on the motor shaft 351. The motor shaft 351 is screwed into a screw hole of the bearing portion 332.

A guide rod 36, the upper end of which is supported by the main body of the apparatus, is slidably fitted to the bearing portion 331, and guides the recording head 31 so as to move up and down while maintaining the horizontal state. .

The head units 34Y, 34M, 34
A large number of nozzles are arrayed in the width direction of the paper on the nozzle surface of the lower surface of C and 34B. Each of these nozzles communicates with an unillustrated pressurizing chamber formed in the head unit corresponding to each nozzle, and each pressurizing chamber further communicates with an unillustrated ink liquid chamber formed in each head unit. It is in communication. Then, each head unit 34Y, 34M,
The ink liquid chambers 34C and 34B are respectively supplied to the ink tanks 12Y, 12M, and
It communicates with 12C and 12B. Further, a piezoelectric element is disposed on one side wall of the pressure chamber, and the deformation of the piezoelectric element pressurizes the pressure chamber, whereby ink is ejected from each nozzle.

As shown in FIG. 1, the cap portion 32 is provided with caps 37Y, 37M, 3 disposed on the left side of the head units 34Y, 34M, 34C, 34B, respectively.
7C, 37B and head units 34Y, 34M, 34
C and 34B are provided on both outer sides in the paper width direction (upper and lower sides in FIG. 1A) and endless wires 38 and 38.

Caps 37Y, 37M, 37C, 37B
Are head units 34Y, 34M, 34C,
Each nozzle is closed (capped) by closely contacting the nozzle surface of 34B. When not capped, the closed surface is arranged in a direction orthogonal to the nozzle surface as shown in FIG. ing.

The caps 37Y, 37M, 37C, 3
7B is a rotation shaft 39Y, 39M, 3 extending in the paper width direction.
It is rotatably supported by each of 9C and 39B about each axis. These rotary shafts 39Y, 39
M, 39C and 39B are fixed to the apparatus main body.

Caps 37Y, 37M, 37C, 37B
As shown in FIG. 2, one end of each of the wires 40Y, 40M, 40C, and 40B is provided with a screw 4 on the side surface in the paper width direction.
They are fixed by 1Y, 41M, 41C, 41B, and the other ends of these wires 40Y, 40M, 40C, 40B are connected and fixed to the endless wire 38, respectively.

Similarly, the caps 37Y, 37M,
One end of a wire (not shown) is screwed to the side surfaces of the sheets 37C and 37B on the opposite side in the paper width direction, and the other end of each wire is connected and fixed to the endless wire 38.

The endless wires 38, 38 are, as shown in FIG. 1, the drive rollers 4 disposed on both outer sides of the head unit.
2 and the driven roller 43. Drive roller 4
2 is for rotating the endless wires 38, 38 by rotating.

Next, the operation will be described. When printing is performed, first, the recording head 31 is arranged at the printing position as shown in FIG. 3, and then the recording paper is conveyed from the paper feed cassette 11 by driving the paper feed roller 21 and the conveyance roller pair 22. The endless belt 1 is conveyed along the path 15 and is secondarily fed by the registration roller pair 23.
3 and is adsorbed to the endless belt 13 by electrostatic force or the like and conveyed.

On the other hand, the head units 34Y, 34 of the recording head 31 are synchronized with the timing of the secondary sheet feeding.
The pressure chambers in M, 34C, and 34B are pressurized, and the ink filled from the ink liquid chamber is ejected from each nozzle toward the recording paper conveyed by the endless belt 13 to perform color printing. . The printed recording paper is sent to the discharge roller pair 26 by the endless belt 13 and discharged from the discharge port 27 onto the discharge tray 28 by the discharge roller pair 26.

When printing is completed, the nozzle surface of each head unit of the recording head 31 is capped. This capping operation will be described with reference to FIG.

First, by rotating the head lifting motor 35 in the forward direction, the nozzle surfaces of the head units 34Y, 34M, 34C and 34B, as shown in FIG. 4, support the respective rotating shafts 39Y, 39M and 39C. 39B
Print head 3 so that it is slightly higher than the height position of
Increase 1

Next, the drive roller 42 is rotated counterclockwise to drive the endless wire 38 in a circular motion. As a result, the caps 37Y, 37M, 37C, 37B have their lower ends pulled in the upper right direction by the wires 40Y, 40M, 40C, 40B, respectively, and the rotation shafts 39Y, 39M, 3
It rotates counterclockwise around 9C and 39B (Fig. 4).
of). Then, the head units 34Y, 34M, 34
When the nozzle surfaces of C and 34B are capped by the caps 37Y, 37M, 37C and 37B, respectively, as shown in FIG. 4, the rotation of the drive roller 42 is stopped. The capping state is maintained during the standing without printing.

When printing is started from the state shown in FIG. 4, first, the driving roller 42 is rotated clockwise to orbit the endless wire 38. As a result, the caps 37Y, 37M, 37C, 37B are
It rotates clockwise about the rotation shafts 39Y, 39M, 39C and 39B, and goes through the state of FIG. 4 to the state shown in FIG.

Next, the recording head 31 is lowered by rotating the head lifting motor 35 in the reverse direction to move the head units 34Y, 34M, 34C, as shown in FIG.
The nozzle surface of 34B is arranged at a printing position separated from the paper surface of the recording paper conveyed by the endless belt 13 by a minute distance.

In this way, the head units 34Y, 34
When capping the nozzle surfaces of M, 34C and 34B is not performed, caps 37Y, 37M, 37C and 37B are used.
Since the closing surface is arranged in the direction orthogonal to the nozzle surface, the space occupied by the cap can be greatly reduced, and the device can be miniaturized.

The caps 37Y, 37M, 37C,
37B to the head units 34Y, 34M, 34C, 34
It is arranged in the vicinity of B, and the rotary shafts 39Y, 39M,
Since capping is performed by rotating around 39C and 39B, the time required for the capping operation can be shortened.

The present invention also includes the following modifications (1) to (1).
(7) can also be adopted. (1) Fix the caps 37Y, 37M, 37C, 37B to the rotating shafts 39Y, 39M, 39C, 39B, respectively,
Each of the rotating shafts may be rotatably supported by the device body by bearings or the like.

(2) As shown in FIG. 5, the endless wire 38
Immediately below the shafts 51Y, 51M,
You may make it arrange | position 51C and 51B. This axis 5
1Y, 51M, 51C and 51B are caps 37Y, 37M, 37C and 3 in the capping state, respectively.
7B is provided immediately on the upper right, and is fixedly or rotatably supported on the main body of the apparatus.

In the case of FIG. 5, when the drive roller 42 is rotated counterclockwise to drive the endless wire 38 in a circular manner,
As in the case of FIG. 4, the caps 37Y, 37M, 37
The lower ends of C and 37B are wires 40Y and 40M,
The head units 34Y and 34 are pulled in the upper right direction by 40C and 40B and rotate counterclockwise around the rotation shafts 39Y, 39M, 39C and 39B (in FIG. 5).
As shown in FIG. 5, the nozzle surfaces of M, 34C and 34B are caps 37Y, 37M, 37C and 37B, respectively.
When capped by, the rotation of the drive roller 42 is stopped.

During this capping, the shafts 51Y, 51
Wires 40Y, 40M, by M, 51C, 51B
40C and 40B are caps 37Y, 37M, 37C and 3
The direction of the force pulling 7B is the vertical direction, that is, the caps 37Y, 37M, 37C and 37B are the head unit 3
4Y, 34M, 34C, 34B can be brought close to the direction of close contact. Therefore, the adhesion of the cap to the head unit can be increased, and thereby capping can be performed more reliably.

(3) Caps 37Y, 37M, 37C,
37B may be connected by a plate member. The plate-shaped member is attached to the caps 37Y, 37M, 37C, 37B so as to be rotatable around the screws 41Y, 41M, 41C, 41B by screws 41Y, 41M, 41C, 41B. In this case, the caps 37Y, 37M, 37C, 37B can be pulled only by the wire 40Y, and the wires 40M, 40C, 40B can be eliminated.

(4) In the modification (1), gears may be fixed to the rotary shafts 39Y, 39M, 39C and 39B, and the gears may be connected to the motor shaft of the motor. In this case, the endless belts 38, 38, rollers 42, 43, wires 40Y, 40M, 40C, 40B
And each screw becomes unnecessary. Then, each cap is rotated by rotating each rotating shaft by the rotational driving of the motor, and the nozzle surface of each head unit is capped. A motor may be provided for each rotation shaft of each cap, or one motor may be connected to each rotation shaft by a gear.

(5) In the modified embodiment (1), a toothed belt is stretched instead of the endless belts 38, 38, and a belt wheel meshing with the toothed belt is used as a rotating shaft 39.
You may make it fix to Y, 39M, 39C, 39B. In this case, the wires 40Y, 40M, 40C, 4
0B and each screw are unnecessary.

(6) As shown in FIG. 6, the cap 37
A rotatable roller whose peripheral surface is in contact with the belt surface of the endless belt 13 may be attached to the side surfaces of the Y, 37M, 37C, and 37B in the paper width direction. Since the conveyed recording paper can be pressed outside the printing range by this roller, it is possible to prevent the recording paper from being bent, and thus the printing quality can be improved.

(7) In the above embodiment, the apparatus capable of color printing has been described, but the invention is not limited to this, and the ink tank 12B storing the black ink and the head unit 34.
A device capable of black-and-white printing provided with B may be used.

[0046]

As described above, according to the first aspect of the invention, the closed surface of the cap faces the side surface parallel to the nozzle arrangement direction of the recording head in the direction orthogonal to the nozzle surface of the recording head. Since the cap is moved to the separated position, the space occupied by the cap can be reduced as compared with the case where the closing surface and the nozzle surface are parallel to each other, whereby the device can be downsized.

According to the second aspect of the invention, since the cap located at the separated position is moved to close the nozzle surface of the recording head located at the retracted position, the nozzle surface of the recording head is covered by the cap. Can be occluded without hindrance. Further, the time required for this closing operation can be shortened.

According to the third aspect of the present invention, the cap is rotated from the separated position about the rotation axis parallel to the nozzle arrangement direction. Therefore, the cap can be easily moved to the retracted position in a short time. The nozzle surface of a certain recording head can be closed.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a printing unit 14 of an embodiment of an inkjet recording apparatus according to the present invention, in which (a) is a plan view,
(B) is a front view.

FIG. 2 is a partial perspective view of a cap portion 32.

FIG. 3 is a front view showing the internal configuration of the same embodiment.

FIG. 4 is an explanatory diagram of a capping operation.

FIG. 5 is an explanatory diagram of a capping operation according to another embodiment of the cap portion.

FIG. 6 is a front view showing a form in which a roller is attached to the cap.

[Explanation of symbols]

 14 printing section 31 recording head 32 cap section 33 unit holding section 34Y, 34M, 34C, 34B head unit 35 head lifting motor 37Y, 37M, 37C, 37B cap 38 endless wire 39Y, 39M, 39C, 39B rotating shaft 40Y, 40M , 40C, 40B wire 41Y, 41M, 41C, 41B screw

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Takatoshi Nishimura 1-22 Tamatsukuri, Chuo-ku, Osaka Mita Industrial Co., Ltd. (72) Motoyuki Fukuda 1-2-2 Tamatsukuri, Chuo-ku, Osaka Within Mita Engineering Co., Ltd.

Claims (3)

[Claims] 1. A recording head in which nozzles for ejecting ink are formed in an array on a surface facing a recording sheet, a cap that is in close contact with the recording head and closes the nozzle surface, and a closing position that closes the nozzle surface. And a cap supporting means for movably supporting the cap between a separation position facing a side surface parallel to the nozzle array direction of the recording head, and a closed surface of the cap in a direction orthogonal to the nozzle surface. An inkjet recording apparatus comprising: a cap moving unit that moves the cap to the separated position. 2. The ink jet recording apparatus according to claim 1, wherein the recording is performed between a print position at which a nozzle surface of the recording head is separated from the paper surface of the recording paper by a minute distance and a retracted position retracted from the print position. A head supporting means for movably supporting the head and a head moving means for moving the recording head between the printing position and the retracted position are provided, and the cap moving means is the cap located at the separated position. The inkjet recording apparatus is characterized in that the nozzle surface of the recording head located at the retracted position is closed by the cap. 3. The ink jet recording apparatus according to claim 2, wherein the cap moving means rotates the cap about a rotation axis parallel to the nozzle arrangement direction.