JPH10250086A - Wiper for ink jet printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To protect the nozzle surface of a recording head at the time of wiping off the nozzle surface with a wiper member by composing the wiper member principally of a rubber based wiper material and setting the volumetric ratio of carbon in the wiper material at a specified value or below. SOLUTION: A wiper member 32 movable relatively to a recording head 5 is disposed contiguously to a purge unit 31 on the recording area side in order to wipe off the nozzle surface of the recording head 5 and a protective cap 33 is disposed on the opposite side while covering the nozzle surface of the recording head 5 when printing is not performed in order to prevent evaporation of ink thus avoiding dry up of the nozzle surface. The wiper member 32 is composed of ethylene propylene rubber containing carbon by 10vol.% or less. According to the arrangement, the nozzle surface is protected against damage due to carbon contained in the wiper member 32 at the time of wiping.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a wiping device for an ink jet printer.

[0002]

2. Description of the Related Art Conventionally, an ink jet printer having a recording head having nozzles for discharging ink droplets onto a recording medium such as printing paper, and performing a recording operation on the recording medium by the recording head, has been proposed. There has been known a printer provided with a wiper member that can move relative to a recording head so as to wipe a nozzle surface.

As the wiper member 101, for example, as shown in FIG. 6, there is a wiper member 101 having a nozzle wiping portion 101a for wiping a nozzle surface of a recording head, and a wiper support portion 101b inserted into and supported by a wiper holder. Such a wiper member 101 is formed by cutting a sheet-like elastic material having flexibility into a predetermined width and length, and the thickness of the nozzle wiping portion 101a is uniform. And
The general composition of the elastic material forming the wiper member is as follows: rubber component 35-60%, carbon 20-40%, oil 10
-30%, and 1% of other vulcanizing chemicals.

[0004]

However, as described above, 20 to 20 carbon atoms are contained in the wiper material of the wiper member.
When the content is about 40%, when the nozzle surface of the recording head is wiped by the wiper member, there is a problem that the nozzle surface of the recording head is damaged by carbon contained in the wiper material.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and when the wiper member wipes the nozzle surface of the recording head, the nozzle surface of the recording head may be damaged by carbon contained in the wiper material. An object of the present invention is to provide a wiping device for an inkjet printer.

[0006]

According to a first aspect of the present invention, there is provided a recording head having a nozzle for discharging ink droplets on a recording medium and performing a recording operation on the recording medium, and wiping a nozzle surface of the recording head. In a wiping apparatus of an ink jet printer having a wiper member relatively movable with respect to a recording head, the wiper member is mainly composed of a rubber-based wiper material, and a ratio of carbon in the wiper material is about 10%. It is less than the capacity%.

Therefore, the wiper member has a carbon content of less than about 10% by volume in the wiper material. Therefore, when the wiper member wipes the nozzle surface of the recording head, the carbon contained in the wiper member reduces the amount of carbon contained in the wiper member. This eliminates the risk of damaging the nozzle surface of the recording head.

According to a second aspect of the present invention, in the wiping apparatus for an ink jet printer according to the first aspect, a main component of the rubber-based wiper material is ethylene propylene rubber.

Accordingly, since the main component of the rubber-based wiper material is ethylene propylene rubber, the wiper member can be manufactured at low cost.

According to a third aspect of the present invention, in the wiping apparatus for an ink jet printer according to the first or second aspect, a tip portion of the nozzle wiping portion of the wiper member is formed to be narrower than other portions.

Accordingly, the nozzle wiping portion of the wiper member has a tip portion for wiping the nozzle surface of the recording head thinner than the other portion. The amount of ink adhering (residual) to the leading end surface of the wiping portion is reduced as much as possible, and the adhesion of ink to the nozzle surface of the recording head during the wiping operation is reduced.

According to a fourth aspect of the present invention, in the wiping apparatus for an ink jet printer according to any one of the first to third aspects,
The wiper supporting portion is formed to be thicker than the nozzle wiping portion.

Therefore, the rigidity of the wiper supporting portion can be made higher than the rigidity of the nozzle wiping portion by a simple structure in which the wiper supporting portion is made thicker than the nozzle wiping portion. Since it has, it can be easily inserted into the wiper holder.

According to a fifth aspect of the present invention, in the wiping apparatus for an ink jet printer according to any one of the first to fourth aspects, the wiper member wipes a nozzle surface of a recording head, and a wiper supported by a wiper holder. And a force for wiping the nozzle surface by the nozzle wiping unit is set to about 0.36 g / mm to 2.14 g / mm.

Therefore, when the nozzle surface of the recording head is wiped by the wiper member, the force for wiping the nozzle surface by the nozzle wiping unit is set to about 0.36 g / mm to 2.14 g / mm. It comes into contact with the nozzle surface of the head with an appropriate pressure, and the nozzle surface (for example, a water-repellent film)
There is no risk of damage.

[0016]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic perspective view showing the overall configuration of an ink jet printer. In FIG. 1, an inkjet printer 1 has a rotating shaft (not shown) extending in the left-right direction.
And has a cylindrical platen roller 3 rotatably supported on the frame 2 by the roller. The platen roller 3 is provided with a printing paper 4 supplied from a paper cassette or a manual paper feeding unit.
The recording medium is conveyed while facing the recording head 5, and constitutes a part of a so-called paper feeder. The recording head 5 is an ink jet type having a nozzle for ejecting ink droplets on the printing paper 4 and performing a recording operation on the printing paper 4.
m of water-repellent film (non-wet coat).

The printing paper 4 is supplied in the direction of arrow A from a paper supply opening (not shown) behind the frame 2, is fed in the direction of arrow B by the rotation of the platen roller 3, and is supplied to the paper discharge opening (not shown). ) Is discharged in the direction of arrow C.

A carriage 6 is provided in front of the platen roller 3 so as to be movable in the direction of arrow D along the axis of the platen roller 3. The carriage 6 has a recording head 5 and an ink cartridge 7 containing ink supplied to the recording head 5 detachably mounted thereon. In this example, the recording head 5 and the ink cartridge 7 are mounted for each of the four colors of yellow, black, cyan, and magenta.

A carriage shaft 8 is provided in parallel with the axis of the platen roller 3. A carriage 6 is slidably fitted on the carriage shaft 8. Also,
The engaging portion 6a of the carriage 6 is guided by a guide rail 9 extending parallel to the carriage shaft 8. Thus, the recording head 5 mounted on the carriage 6 can reciprocate by sliding along the axis of the platen roller 3. The carriage 6
Is configured to reciprocate the carriage 6 by a carriage drive motor 10 via a belt drive mechanism 14 having a belt 11 and pulleys 12 and 13.
Incidentally, as the carriage drive motor 10, a step motor or a DC motor is used.

On the right side of the recording area corresponding to the platen roller 3, there is formed a recovery area in which a purge device 31 for recovering from non-ejection or ejection failure of the recording head 5 is provided. Such a purging device 31
Is provided by the ink jet recording head 5
The reason is that a discharge failure occurs due to a cause such as generation of bubbles inside the ink or drying of the ink during use, and this is to recover the discharge state to a favorable discharge state.

A wiper member 32 is provided adjacent to the purging device 31 and movable toward the recording area so as to wipe the nozzle surface of the recording head 5 relative to the recording head 5.
On the opposite side, protective cap devices 33 are provided to cover the nozzle surface of the recording head 5 when printing is not performed, to prevent ink evaporation and to prevent the nozzle surface from drying.

As shown in FIGS. 2 and 3, the wiper member 32 has a nozzle wiping portion 32a for wiping the nozzle surface of the recording head 5, and an insertion hole for the wiper holder 34 which is provided in continuation of the nozzle wiping portion 32a. And a wiper supporting portion 32b inserted into and supported by 34a.

The nozzle wiping portion 32a is cut so that the area of the front end surface is smaller than the cross-sectional area of the other portion, that is, the front end portion of the nozzle wiping portion 32a becomes closer to the printing paper 4 side. It is formed on an inclined surface 32c that reduces the area.

Therefore, the nozzle wiping portion 32a has a tip portion for wiping the nozzle surface of the recording head 5 which is thinner than the other portions.
2a), the amount of ink adhering (residual) to the leading end surface is reduced as much as possible, and the amount of ink adhering (residual) to the nozzle surface of the recording head 5 is reduced. In particular, since the inclined surface 32c is provided on the side of the printing paper 4 on the side of the printing paper 4 which has almost no influence on the wiping of the ink on the nozzle surface of the recording head 5, the nozzle wiping unit 32a does not impair the ink wiping function. Adhesion of ink to the leading end surface of the nozzle 32a is avoided.

The wiper holder 34 of the wiper member 32
Wiper support 32b to facilitate insertion into the
In order to increase the rigidity of the nozzle, the wiper supporting portion 32b is formed thicker than the nozzle wiping portion 32a. For example, while the thickness A of the nozzle wiping portion 32a is 0.85 mm, the thickness B of the wiper support portion 32b is 2.3 mm.

The wiper member 32 is made of ethylene propylene rubber (EP) having a carbon content of less than about 10% by volume.
DM) so that the nozzle surface is not likely to be damaged by the carbon contained in the wiper member 32 when wiping by the wiper member 32. Further, since the wiper member 32 is blackened by carbon, even if the ink is wiped off for a long time, the stain is not conspicuous.

The wiper member 32 has a hardness of 40.
The force of wiping the nozzle surface by the nozzle wiping unit 32a is set in a range of about 0.36 g / mm to 2.14 g / mm.

Here, the force for wiping the nozzle surface by the nozzle wiping portion 32a is about 0.36 g / mm to 2.14 g / m.
The setting in the range of m is based on the experimental results shown in Table 1 below. In this experiment, a wiper member (EPDM, hardness 40 degrees, thickness of the nozzle wiping part 0.85
mm, width 14 mm) and the nozzle surface of the recording head covered with a water-repellent film having a thickness of 0.7 μm (32 nozzles × 2 rows)
After the wiping operation was performed 3000 times, the degree of scratches was determined with a microscope (magnification: 200 times), a pin check pattern was printed after purging, and it was determined whether or not the ejection was performed. (Ch) The number (number of nozzles) was checked. The wiper load is
The wiper load is set using a tension gauge, and the wiper load divided by the wiper width of 14 mm is used as the wiper load per 1 mm.

[Table 1] Therefore, when the wiping by the wiper member 32 is performed when the force of wiping the nozzle surface 5a of the recording head 5 by the nozzle wiping unit 32a is in the range of about 0.36 g / mm to 2.14 g / mm,
It can be seen that there is no risk of damaging the nozzle surface (for example, the water-repellent film).

As shown in FIG. 4, the wiper support portion 32b has an engagement recess 32d, while the wiper holder 34 has an engagement projection 34b which is elastically engageable with the engagement recess 32d. The wiper member 32 is held by the wiper holder 34 by their elastic engagement. Then, the wiper holder 32b is connected to the wiper holder 3
As described above, since the wiper supporting portion 34b is thicker than the nozzle wiping portion 32a and is formed rigidly when inserted into the nozzle 4, the engaging convex portion 34b and the engaging concave portion 32d are easily elastically engaged. be able to.

The purging device 31 can move between a protruding position protruding into the moving path of the recording head 5 and a standby position retreating from the moving path of the recording head 5. A suction cap 41 that is in close contact with the nozzle surface, and a suction pump 42 that generates a negative pressure when the recording head 5 is covered with the suction cap 41 at the protruding position to suction and remove ink in the recording head 5. It has.

Then, the wiper holder 34 (therefore, the wiper member 32), the suction cap 41 and the suction pump 4
2 is associated with a driving means (wiper driving means) having a cam member 43 which is rotationally driven, and the wiper member 3
2, advance and retreat of the suction cap 41 and the suction pump 42
Is controlled by the common cam member 43.

The cam member 43 has a driving gear 46 provided integrally, and the driving gear 46 is driven to rotate by driving means such as a driving motor of a paper feeder.

The rear end (cam follower) of the wiper holder 34 that supports the wiper member 32 is movably engaged with the first cam groove 43a of the cam member 43, whereby the cam member 43 is rotated. At a certain timing, the wiper member 32 is orthogonal to the moving path of the recording head 5 at a certain timing between a projecting position where the wiper member 32 protrudes into the moving path of the recording head 5 and a standby position retracted from the moving path of the recording head 5. Is controlled to wipe the nozzle surface of the recording head 5 at the projecting position.

Further, as shown in FIG.
1 is supported by the cap holder 44, and the rear end portion (cam follower portion) of the cap holder 44 has the second cam groove 43b of the cam member 43 on the same plane as the first cam groove 43a.
Are movably engaged with. Thereby, the cam member 4
The rotation of the recording head 5 causes the suction cap 41 to move at a fixed timing between the projecting position where the suction cap 41 protrudes into the moving path of the recording head 5 and the standby position where the suction cap 41 is retracted from the moving path of the recording head 5. Is reciprocated in a direction orthogonal to the moving path of the recording head 5 and is controlled so as to cover the nozzle surface of the recording head 5 at the projecting position. 45 is the cam member 4
3 is the rotation axis.

The suction pump 42 includes a frame member 51.
The first and second piston members 53 and 54 are independently and movably fitted into a cylindrical pump casing 52 attached and fixed to the pump casing 52. The pump casing 52 is provided with a suction port 52a and a discharge port 52b (see FIG. 1) at predetermined intervals in the axial direction.
Is connected to a suction cap 41 via a suction pipe 55, and the outlet 52b is linked to a waste ink tank 58 in which an adsorbent 57 is stored (see FIG. 1). The first and second piston members 53 and 54 are respectively connected to the first and second piston members 53 and 54.
Are connected to one end portions of the drive shaft members 61 and 62, and are driven by the drive shaft members 61 and 62, so that the pump casing 5
A pump chamber is formed between the two piston members 53 and 54 in the pump chamber 2. The first drive shaft member 61
Are slidably fitted into the second drive shaft member 62, and the cam follower member 6 at the other end of each of the drive shaft members 61, 62.
3, 64 are movably engaged with the cam grooves 43c, 43d of the cam member 43 on the side opposite to the cam grooves 43a, 43b.

Therefore, by rotating the cam member 43 at a constant timing, capping of the suction cap 41, suction of ink by the suction pump 42, and wiping of the nozzle surface of the recording head 5 by the wiper member 32 are sequentially performed. Then, the ink sucked by the suction pump 42 is discharged to the waste ink tank 58 via the suction pump 42 and is adsorbed by the adsorbent 57 in the waste ink tank 58.

In addition, the storage cap device 33 is provided in FIG.
As shown in FIG. 7, a casing 72 having a storage cap 71 and supporting the storage cap 71 is supported by a guide rod member 73 extending parallel to the moving direction of the carriage 6 so as to be slidable and rotatable. I have. The casing 72 engages with the carriage 6 when the carriage 6 moves outside the recording area, and
An engagement projection 72a for sliding movement integrally with the projection is protruded forward. Then, when the carriage 6 moves from the recording area to the recovery area, the carriage 6 engages with the engaging projection 72a of the casing 72, so that the storage cap 71 slides following the movement of the carriage 6 (FIG. 1). At right). During this slide movement,
The casing 72 rotates around the guide rod 73 by the action of the not-shown inclined cam means. As a result, the storage cap 71 moves in the direction of the recording head 5, and the storage cap 71 contacts the nozzle surface of the recording head 5. Then, capping is performed. Thereafter, when the carriage 6 moves again in the recording area direction, the storage cap 71 moves away from the recording head 5 while moving to the recording area side, and returns to the initial state when the carriage 5 comes out of the recovery area.

Next, the operation of the wiper member 32 will be described. The wiping operation by the wiper member 32 removes ink adhering to the nozzle surface of the recording head 5 when the recording head 5 returns from the recovery area to the recording area after the purging operation by the purging device 31 is completed. Done to do so.

First, as shown in FIG. 6A, the remainder of the ink W sucked from the nozzles of the recording head 5 adheres to the nozzle surface 5a of the recording head 5 after the purging operation. The recording head 5 moves to the wiper member 32 adjacent to the purge device 31 to return to the recording area. At this time, the wiper member 32 is advanced by the control of the cam member 43 from a standby position retracted from the moving path of the recording head 5 to a projecting position protruding into the moving path of the recording head 5.

When the recording head 5 moves toward the wiper member 32 at the protruding position, as shown in FIG. 6B, the nozzle surface 5a of the recording head 5 is attached to the nozzle wiping portion 32a of the wiper member 32. The front end portion is pressed against, the nozzle wiping portion 32a is largely bent, and the ink W attached to the nozzle surface 5a is scraped off. In this case, the nozzle wiping unit 32a
At the tip end formed by a surface of the wiper member 32 opposite to the inclined surface 32c at the tip end portion of the nozzle wiping portion 32a, the nozzle surface 5a Since the upper ink W is scraped, the scraping of the ink W is effectively performed. In addition, since the tip portion of the nozzle wiping portion 32a is thinner than the other portion, the narrow space formed by the thickness of the tip surface and the nozzle surface 5a is significantly reduced, and is held there by capillary action. Less ink. As a result, the ink W is applied to the tip surface of the wiper member 32 and the nozzle surface 5.
a (see FIG. 6C), and the nozzle surface 5a of the print head 5 during the next wiping operation.
The ink does not remain on the side as much as before.

Therefore, by using the wiper member 32, the adhesion (residual) of the ink to the nozzle surface 5a of the recording head 5 during the wiping operation can be greatly reduced, and the adhesion of such ink ( Ink ejection failure of the recording head 5 due to (residual) can be avoided, and good printing performance can be secured.

[0043]

The present invention is embodied in the form described above, and has the following effects.

According to the first aspect of the present invention, as described above, the wiper member is formed by reducing the ratio of carbon in the wiper material to about 10% by volume.
Therefore, when the wiper member wipes the nozzle surface of the print head with the wiper member, there is no possibility that the nozzle surface of the print head is damaged by carbon contained in the wiper member. Further, since the wiper member is black with carbon, the stain is not noticeable by wiping the ink.

According to the second aspect of the present invention, since the main component of the wiper material is ethylene propylene rubber, the wiper member can be manufactured at low cost.

According to the second aspect of the present invention, the nozzle wiping portion of the wiper member is formed so that the tip end for wiping the nozzle surface of the recording head is thinner than the other portions, so that the nozzle surface is applied with an appropriate pressure. It is possible to minimize the amount of ink adhering (residual) to the tip end surface and the nozzle surface of the wiper member (nozzle wiping unit) while making contact with the wiper member. Adhesion (residual) can be greatly reduced, and ink ejection failure of the recording head due to such adhesion of ink can be avoided.

According to the third aspect of the present invention, since the wiper supporting portion is formed thicker than the nozzle wiping portion, the rigidity of the wiper supporting portion is increased, and the wiper supporting portion is inserted when the wiper supporting portion is inserted into the wiper holder. Can be prevented from being carelessly bent, and the wiper support can be easily inserted into the wiper holder.

According to a fifth aspect of the present invention, the force for wiping the nozzle surface by the nozzle wiping portion of the wiper member is about 0.36 g / mm to about 0.36 g / mm.
Since it is set to the range of 2.14 g / mm, there is no risk of damaging the nozzle surface (for example, a water-repellent film) when the wiper member wipes the nozzle surface of the recording head.

[Brief description of the drawings]

FIG. 1 is a perspective view illustrating a schematic configuration of an ink jet printer according to the present invention.

FIG. 2 is an explanatory diagram of a wiper member and a wiper holder according to the present invention.

FIG. 3 is an explanatory view of a state in which a wiper member according to the present invention is attached to a wiper holder.

FIG. 4 is a cross-sectional view illustrating a relationship between a wiper member, a suction cap, a suction pump, and a cam member according to the present invention.

FIG. 5 is an explanatory diagram of a wiping operation.

FIG. 6 is an explanatory view of a conventional wiper member.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ink jet printer 4 Printing paper 5 Recording head 32 Wiper member 32a Nozzle wiping part 32b Wiper support part 32c Inclined surface 34 Wiper holder 43 Cam member

Claims (5)

[Claims] A recording head having a nozzle for ejecting ink droplets on the recording medium and performing a recording operation on the recording medium; and a movable relative to the recording head so as to wipe a nozzle surface of the recording head. A wiper device for an ink jet printer having a wiper member, wherein the wiper member is mainly composed of a rubber-based wiper material, and a ratio of carbon in the wiper material is less than about 10% by volume. Wiping device for inkjet printers. 2. The wiping device of an ink jet printer according to claim 1, wherein a main component of said rubber-based wiper material is ethylene propylene rubber. 3. The nozzle wiping portion of the wiper member, wherein a tip portion is formed to be more tapered than another portion.
Or a wiping device for an ink jet printer according to item 2. 4. The wiping device for an ink jet printer according to claim 1, wherein said wiper supporting portion is formed thicker than a nozzle wiping portion. 5. The wiper member has a nozzle wiping portion for wiping a nozzle surface of a recording head, and a wiper supporting portion supported by a wiper holder, and a force for wiping the nozzle surface by the nozzle wiping portion is about 0. The wiping device for an ink jet printer according to any one of claims 1 to 4, wherein the wiping device is set at 36 g / mm to 2.14 g / mm.