JP2001353860A - Ink jet printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance not only the print quality but also the maintainability of an ink head. SOLUTION: A mechanism 100 for adjusting the interval between an ink head 21a and a sheet P can also adjust the interval between the ink head 21a and the cleaning head 31a of a maintenance unit 31. Consequently, the interval between the ink head 21a and the sheet P is set appropriately depending on the thickness of the sheet P and the interval between the ink head 21a and the cleaning head 31a is also set appropriately depending on the thickness of the sheet P.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet printer having an adjusting mechanism for adjusting the distance between an ink head and the surface of a sheet.

[0002]

2. Description of the Related Art In an ink jet printer which performs printing on paper by reciprocating an ink carriage equipped with an ink head in a main scanning direction, in order to ensure high print quality, the ink head and the paper to be printed are required to have a high quality. The spacing between them is important. In other words, by keeping the distance at which ink droplets ejected from the ink head land on the paper,
The printing result becomes stable.

For example, the quality of print dots (reduction of satellite dots), landing accuracy, and the like are better as the distance between the ink head and the paper is smaller. However, if the distance is too small, the gap between the ink head and the paper becomes smaller. During printing, the two come into contact with each other, resulting in poor printing. Also, if the gap is different between the forward movement and the double movement of the ink carriage during bidirectional printing, a difference occurs in the flight time of the ink dots, and the landing position in the double scanning direction orthogonal to the main scanning direction is shifted, The printing quality will be degraded. For this reason, the interval between the ink head and the paper is 1.0
It is necessary to maintain a stable value within the range of 1.5 mm.

However, there are various types of paper, and the thickness varies depending on the type of paper. Therefore, when the thickness of the paper changes due to a change in the type of paper to be printed, the distance between the ink head and the paper surface also changes.

Therefore, conventionally, the user changes the height level of the ink carriage by operating the lever in accordance with the change in the type (thickness) of the paper used, so that the distance between the ink head and the surface of the paper is kept constant. The structure which makes it do is adopted.

Japanese Patent Laid-Open Publication No. Sho 59-12887 discloses that the position of the ink carriage is set to gradually decrease as it approaches the end in the main scanning direction. , The ink carriage is inclined at that point, and even at the end where paper warpage or swelling is likely to occur, a configuration is disclosed in which printing is performed smoothly without contact between the ink head and the paper.

[0007]

A maintenance unit having a cleaning head for cleaning the ink head is provided at one end in the main scanning direction. However, in the above-described conventional configuration, although the distance between the ink head and the paper is kept constant, no consideration is given to the positional relationship between the ink head and the cleaning head.

The above-mentioned maintenance unit carries out the following operation as a maintenance step in order to surely discharge ink from the ink head.

(1) A head cap for preventing the ink in the head orifice from drying. (2) Cleaning for preventing a change in the ejection direction due to adhesion of dust or the like to the head ejection portion.

(3) Ink suction for recovering a discharge failure due to air mixing inside the ink nozzle.

(4) Receiving the purged ink in the ink purging step of replacing the dried ink in the orifice portion and the mixed ink with normal ink.

Here, in the above maintenance process,
In the above (1) and (3), the configuration is made in consideration of the adhesion between the maintenance unit and the ink head.
The air pressure is adjusted for the suction step and the discharge step. This air pressure adjustment is performed in the above (1), (3)
In, after the initial height is set in a state where the maintenance cap is pressed against the ink head, the pressure is adjusted. Therefore, even if the interval between the maintenance unit and the ink head varies, the influence on each process is negligible (the difference in height is 0.25 mm).
About 0.5 mm).

However, in the above (2), since the elastic blade standing upright on the maintenance unit is used, the contact pressure with the elastic blade ink head is designed to be constant. Therefore, when the height change as described above occurs, the contact pressure between the elastic blade and the ink head changes, and cleaning failure occurs. The occurrence of the cleaning failure causes not only the cleaning failure between the ink heads but also the color mixture development of the ink, particularly when a plurality of ink heads are arranged, and thus the print quality is deteriorated. .

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-described problem, and it is not only possible to reduce the distance between the ink head and the paper but also the distance between the maintenance unit, the ink head and the maintenance unit. It is an object of the present invention to provide an ink jet printer that can improve not only print quality but also maintainability of an ink head by keeping the print quality constant.

[0015]

The present invention has the following arrangement as means for solving the above-mentioned problems.

(1) An ink carriage mounted in the main scanning direction with an ink head facing the paper surface, an adjustment mechanism for adjusting the distance between the ink head and the paper surface by displacing the ink carriage, and main scanning. And a cleaning head disposed at a predetermined position in the direction, wherein the adjustment mechanism also serves as an adjustment mechanism for adjusting the distance between the ink head and the cleaning head.

In this configuration, the interval between the ink head and the paper is variably adjusted by the adjusting mechanism, while the interval between the ink head and the cleaning head is adjusted at a predetermined position in the scanning direction of the ink carriage. For this reason, the ink head is appropriately opposed to the cleaning head, the ink head is reliably cleaned, and the quality of an image printed on paper can be improved.

(2) The adjusting mechanism is characterized in that the distance between the ink head and the surface of the paper is adjusted to be constant according to the thickness of the paper.

In this configuration, first, the gap between the ink head and the paper, which is important for printing, is adjusted to be constant according to the thickness of the paper by the adjusting mechanism. Since the distance between the ink head and the cleaning head is adjusted correspondingly, the distance between the ink head and the cleaning head is more accurately maintained, and the cleaning effect of the ink head is further enhanced.

(3) The adjusting mechanism includes an eccentric shaft, which is a support for moving the ink carriage in the scanning direction, and adjusts the distance between the ink head and the surface of the paper by rotating the eccentric shaft. And

In this configuration, the position of the ink carriage in the direction in which the ink head and the paper surface are arranged is changed only by rotating the eccentric shaft, which is one of the support members for moving the ink carriage in the scanning direction, and the ink carriage is moved. The position of the carriage can be easily adjusted.

(4) The cleaning head is disposed at a maintenance position set at an end of the movable support, and the adjusting mechanism moves the ink head and the cleaning head when the ink carriage reaches the maintenance position. A guide member for displacing the ink carriage so as to face at a predetermined interval is provided.

In this configuration, when the ink carriage reaches the maintenance position, the position of the ink carriage is adjusted by the guide member, and the interval between the ink head and the cleaning head is set to a predetermined interval. This allows
The distance between the ink head and the paper surface and the distance between the ink head and the cleaning head are appropriately set. Therefore, the cleaning of the ink head by the cleaning head is reliably performed.

(5) The guide member is a projection that projects from the ink carriage in the sub-scanning direction and a guide groove in the main scanning direction into which the projection of the ink carriage is fitted. And a guide groove whose fitting position of the projection changes in the main scanning direction.

In this configuration, a guide groove is provided in which the fitting position of the protrusion in the arrangement direction of the ink head and the cleaning head changes in the main scanning direction, and the protrusion of the ink carriage fits in this guide groove. Therefore,
When the protrusion of the ink carriage fits into the guide groove-shaped portion of the guide member, according to the fitting position of the protrusion in the scanning direction,
The position of the ink carriage in the direction in which the ink head and the cleaning head are arranged changes, and the distance between the ink head and the cleaning head is more accurately adjusted.

(6) In the adjustment mechanism, the displacement amount of the ink carriage adjusted by the rotation of the movable support member;
The amount of change in the fitting position of the protrusion in the arrangement direction of the ink head and the cleaning head in the guide member is set to be substantially the same.

In this configuration, the amount of change in the fitting position of the protrusion on the guide member is determined by the change in the distance between the ink head and the cleaning head caused by the change in the position of the ink carriage for adjusting the distance between the ink head and the paper surface. It is made substantially equal to the amount of change. Therefore, the change in the distance between the ink head and the cleaning head caused by the adjustment of the distance between the ink head and the paper surface is offset by the fitting of the projection to the guide groove in the guide member, and the ink head and the cleaning head are moved regardless of the displacement of the ink carriage. The space between the ink head and the cleaning head becomes proper, and the ink head can be reliably cleaned.

(7) The adjusting mechanism includes an interlocking means for operating the guide member in conjunction with the rotation of the eccentric shaft.

In this configuration, the position of the guide member changes via the interlocking means with the rotation of the eccentric shaft. For this reason, the ink carriage whose position has been changed by the adjustment mechanism is returned to the original position by the interlocking means via the guide member at the maintenance position. As a result, the displacement of the facing position between the ink head and the cleaning head is corrected, and the cleaning is performed more accurately.

(8) The interlocking means includes a position adjusting section for making the position of the guide member in the arrangement direction of the ink head and the cleaning head correspond to the position of the ink carriage in the direction facing the ink head and the paper surface. It is characterized by.

In this configuration, since the guide member is for returning the ink carriage whose position has changed to the original height, the position of the guide member changed with the rotation of the eccentric shaft is adjusted by the position adjusting unit. Thus, the distance between the cleaning head and the ink head of the maintenance unit is adjusted more appropriately.

(9) The position adjusting section couples between the eccentric shaft side and the guide member to transmit a change in height position level due to the eccentric shaft to the guide member. Characterized by having a movable arm of

In this configuration, when the ink carriage is displaced due to the eccentricity of the eccentric shaft, the movable arm of the position adjusting section is changed, and the displacement of the ink carriage is transmitted to the guide member via the movable arm. Therefore, the position of the ink carriage is appropriately set with a relatively simple configuration.

(10) The interlocking means is provided with a scanning direction position adjusting section for displacing the guide member along the main scanning direction.

In this configuration, since the interlocking means includes the scanning direction position adjusting section, even if the position in the scanning direction is shifted even though the position of the ink head is adjusted by the guide member, The guide member is displaced in the scanning direction by the scanning direction position adjustment unit, and this displacement is canceled.

(11) The scanning direction position adjuster is mounted on a movable arm displaced in a direction opposite to the ink head and the paper surface, and a mounting plate for mounting the guide member so as to be displaceable in the main scanning direction. A fixed cam body having a slope whose distance from the upper surface of the mounting plate increases as the distance from the movable arm in the scanning direction increases, and an elasticity for urging the guide member on the mounting plate in a direction in which the guide member contacts the slope of the fixed cam. A position of the guide member in the main scanning direction is controlled by changing a contact position on a slope of the fixed cam according to the displacement of the movable arm.

In this configuration, when the movable arm is displaced downward due to the eccentric rotation of the eccentric shaft, the opposing distance between the upper surface of the mounting plate on which the guide member is mounted and the inclined surface of the fixed cam body is increased, and the guide member is elastic. It is returned to the movable arm side by the elastic force of the member. Conversely, when the movable arm is displaced upward, the guide member separates from the movable arm side against the elastic force of the elastic member. Thus, the position adjustment of the guide member in the scanning direction is reliably performed with a relatively simple configuration.

[0038]

FIG. 1 is a schematic sectional view of a composite type ink jet printer according to an embodiment of the present invention. The inkjet printer M includes a scanner unit 1 and a printing unit 2. The scanner unit 1 includes an optical unit 11,
An image of a document placed on the platen glass 13 is read by reciprocating the optical unit below the platen glass 13 with the document cover 12 and the platen glass 13.

The printing section 2 includes a paper feed cassette 3, a paper discharge tray 4, a paper transport roller 5, a paper guide 6, an ink carriage 21, a platen 22, a paper feed roller 23, and a paper discharge roller 24. The platen 22 faces the lower surface of the ink carriage 21 with a predetermined gap. The ink carriage 21 includes an ink head 21a and an ink tank 2
1b, and is reciprocally movable in a main scanning direction orthogonal to the paper surface. In the ink carriage 21, an ink tank 21b for supplying ink to the ink head 21a is detachably mounted on the upper surface of the ink head 21a so that the ink tank 21b can be replaced when the ink is exhausted.

The paper guide 6 is disposed between the paper transport roller 5 and the platen 22, and the paper fed from the paper feed cassette 3 via the paper feed roller 23 is fed by the paper transport roller 5 and the paper guide 6. Via the ink carriage 21
And the platen 22. Ink carriage 2
The sheet that has passed between the platen 1 and the platen 22 in the sub-scanning direction, which is a direction orthogonal to the main scanning direction, is discharged onto the discharge tray 4 via the discharge roller 24.

The ink jet printer M has a control unit (not shown) for controlling the scanner unit 1 and the printing unit 2 in an integrated manner. Upon receiving a print request in the copy mode by operating a key switch (not shown), the control unit first outputs control data to the scanner unit 1 and
1 to read the image of the original placed on the platen glass 13 and apply predetermined processing to the read signal output from the optical unit 11 to generate image data together with control data for the printing unit 2. Output. On the other hand, when a print request in the printer mode is received from an external terminal device, the image data output from the terminal device is output to the printing unit 2 together with the control data.

The control unit controls the paper feed roller 23 and the paper transport roller 5 in the printing unit 2 based on the output control data.
Is rotated to feed one sheet of paper P from the paper feed cassette 3 and to guide it between the ink carriage 21 and the platen 22. The control unit reciprocates the ink carriage 21 in the main scanning direction at a timing synchronized with the movement of the sheet P based on the output control data, and drives the ink head 21a based on the image data.

The ink head 21a discharges ink in accordance with image data and prints an image on the paper P. At the time of printing, the transport of the paper P is stopped each time the ink carriage 21 starts scanning one line in the main scanning direction, and the ink head 21a is stopped every time the scanning of one line is completed.
The paper P is transported in the sub-scanning direction by the nozzle arrangement range in the sub-scanning direction. In the printing unit 2, the conveyance stop of the paper P, the scanning of the ink carriage 21, and the conveyance of the paper P are repeated, and the printing of the image on the entire surface of the paper P is performed.

The ink jet printer M has a function of keeping the distance between the ink head 21a and the paper P constant, that is, a function of keeping the distance at which ink droplets ejected from the ink head 21a land on the paper P. ing. As a result, the size of the dots on the surface of the paper P is made constant, and the satellite of the ink particles is reduced.

Further, the member for guiding the ink carriage 21 to the maintenance unit 31 is improved, and the member can be moved up and down, and can be moved forward and backward, so that the ink head 21 can be moved.
This has a function of keeping the distance between the “a” and the maintenance unit 31 constant. Thereby, maintenance of the ink head 21a can be performed more reliably, and the print quality is improved. The specific configuration relating to these will be described below.

FIG. 2 is a front view of the ink carriage of the ink jet printer. FIG. 3 is a side view of the eccentric shaft supporting the ink carriage. The ink carriage 21 is supported by a guide rail 211 and an eccentric shaft 212 arranged in a longitudinal direction in the main scanning direction so as to be reciprocally movable in the main scanning direction. In addition, the adjustment mechanism 100 described below allows the distance between the ink head 21a and the paper P and the ink head 21a
The distance between the maintenance unit 31 and the cleaning head 31a of the maintenance unit 31 described later is set to be adjustable.

As shown in FIGS. 2 and 6, a cylindrical projection 21e is formed on one surface of the ink carriage 21 in the sub-scanning direction (the direction of arrow C), for example, on the downstream side surface (front surface). Further, a holding groove 21c for sliding the rail, which is open to the lower side, is formed in the upper projecting portion at the opposite upstream end (rear end).
1c is fitted to the guide rail 211 to support the ink carriage 21. In the lower part of the rear end of the ink carriage 21, an eccentric shaft insertion hole 2 is provided.
1d is formed, and this eccentric shaft insertion hole 21 is formed.
The ink carriage 21 is supported by inserting the eccentric shaft 212 through d.

As shown in FIG. 3, the eccentric shaft 212 has an eccentric shaft 212a connected to a rotary drive wheel, for example, a drive gear (or cam) 25. For example, the rotation of the gear 25 by manual operation is performed. Eccentric shaft 21
By changing the center position of the ink carriage 2,
The height position level 1 is changed. At the lower eccentric position within the 180 ° rotation range of the eccentric shaft 212, the height level position of the ink carriage 21 is lowered so that printing on the standard paper P such as plain paper is performed, while at the upper eccentric position, thick paper or The height level position of the ink carriage 21 is raised so that printing on an envelope or the like is performed. Accordingly, the distance X between the ink head 21a and the sheet P is determined according to the thickness of the sheet P.
(FIG. 4) can be adjusted.

Guide rail 211 and eccentric shaft 2
Below the right end of 12, the maintenance process (1)-
In order to perform (4), a cleaning maintenance unit 31 for the ink head 21a is provided.

When performing the maintenance steps (1) to (4), the maintenance unit 31 performs the cleaning operation with the ink head 21a substantially in contact with the cleaning head 31a of the maintenance unit 31, as shown in FIG. It is supposed to do. That is, when the cleaning operation is performed, the ink carriage 21a moves to the right while being guided by the guide rail 211 and the eccentric shaft 212, and reaches the cleaning position (a chain line position in FIG. 5). The ink head 21a is opposed to.

In this state, when the maintenance unit 31 moves up by a predetermined stroke, the ink carriage 21 is pushed up, and the guide rail 2 is moved from the holding groove 21c.
Since the ink cartridges 11 are slightly separated from each other, the ink carriage 21 is held by the projections 21 d and the eccentric shaft 212. Thereafter, as shown in FIG. 6, the cleaning operation is performed with the ink head 21a and the cleaning head 31a substantially in contact with each other.

The cleaning head 31a has the ink head 2 for use in the step (2).
An elastic blade 31b capable of cleaning the whole 1a is provided upright. The elastic blade 31b and the ink head 21a come into contact with each other at a constant pressure.

As shown in FIGS. 8 and 9, a guide member (guide member) 40 for positioning the ink head 21a with respect to the cleaning head 31a of the maintenance unit 31 is provided near the maintenance position. The guide member 40 is formed with a slit-shaped guide groove-shaped portion 41 that fits and guides the protrusion 21 e to regulate the height position level of the ink carriage 21. That is, when the ink carriage 21 moves in the scanning direction (the direction of arrow a) and reaches the vicinity of the maintenance unit 31, the slit-shaped guide groove 41 engages with the projection 21 e of the ink carriage 21. Is guided to be positioned at a predetermined site.

Guide groove-shaped portion 41 in guide member 30
As shown in FIGS. 8 and 9, a high-level area (also referred to as a portion corresponding to plain paper) 41 closer to the opening side in the scanning direction.
a, a low-level area (also referred to as a thick paper corresponding part) 41b near the far end in the scanning direction, and both areas 41a, 41
It is formed in the shape of a step having an inclined step 41c connecting the points b.

The guide member 40 is not limited to this embodiment, but has a guide groove 41.
It is sufficient if the protrusions 21e of the ink carriage 21 are fitted so that the height of the ink carriage 21 can be maintained.

As shown in FIGS. 10 and 11, the guide member 40 is mechanically connected to the eccentric shaft 212 via guide member movable arms 511 to 513 of the adjusting mechanism 100. The height level changes in conjunction with the change in the eccentric position.

The adjusting mechanism 100 will now be described with reference to FIG.
This will be described in detail with reference to FIG. Adjustment mechanism 10
0 is approximately the guide rail 211, the eccentric shaft 21
2. It comprises a guide member 40 and a guide member position adjusting means 50. The guide member position adjusting unit 50 is an interlocking unit of the present invention, and includes a height position adjusting unit 51 and a scanning direction position adjusting unit 52.

The height position adjusting section 51 has a fixed fulcrum 51c and a mounting plate 514 on which the guide member 40 is mounted.
First to third movable arms 511 to 51 forming a link
3 is provided.

The lower end of the first movable arm 511 is in contact with the peripheral surface of the eccentric shaft 212 from above. The third movable arm 513 holds the guide member 40 via a mounting plate 514 at the lower end. Second movable arm 512
Has a fixed fulcrum 51c, at one end of which the upper end of the first movable arm 511 is connected and pivoted by a pivot 51a, and at the other end, the third movable arm 5
The upper end of 13 is connected and pivoted by a pivot 51b. The fixed fulcrum 51c is connected to the ink head 21a.
Is set at a position corresponding to the approximate center of.

The scanning direction position adjusting section 52 is held by the third movable arm 513, and has a mounting plate 514 on which the guide member 40 is mounted so as to be displaceable in the scanning direction, and a slope facing the upper surface of the mounting plate 514. A fixed cam body 521 having a triangular body for controlling a guide member separate from the third arm 513 and a fixed cam body 52 for the guide member 40;
1 is a tension coil spring that always applies a return spring force to the slope 521a side (corresponding to an elastic member of the present invention).
522 and the like. Slope 521a of fixed cam body 521
Is inclined with respect to the upper surface of the mounting plate 514, in other words, the distance between the inclined surface 521a and the upper surface of the mounting plate 514 gradually increases as the distance from the third movable arm 513 increases. Is set to Guide member 4
The upper corner Q of the movable arm 513 at 0 is in contact with the slope 521a of the fixed cam body 521 with a return spring force.

Next, the operation of adjusting the height of the ink carriage 21 in the above configuration will be described. As mentioned above,
The ink carriage 21 is supported in a biaxial structure by the guide rail 211 and the eccentric shaft 212.
For this reason, as shown in FIG.
When the eccentric position 2 is in a prescribed state, the upper surface of the platen 22 and the ink head 21a are substantially parallel so as to maintain a predetermined interval. Thus, the surface of the plain paper P disposed on the upper surface of the platen 22 and the ink head 2
A predetermined distance X is maintained with respect to the nozzle tip surface 1a.

However, when the thick paper P is disposed between the ink head 21a and the platen 22, the distance between the nozzle tip surface of the ink head 21a and the surface of the thick paper P is increased by the thickness as compared with the plain paper. Is reduced, and rubbing between the ink head 21a and the paper P may occur.

Therefore, in such a case, the eccentric position of the eccentric shaft 212 is set to 180 ° as shown in FIG.
Rotate. As a result, the ink carriage 21 rises as it is, and the interval between the nozzle surface of the ink head 21a and the surface of the cardboard is adjusted to be the predetermined interval X.
That is, the height position level of the ink head 21a changes depending on the arrangement positions of the guide rail 211 and the eccentric shaft 212. That is, regarding the distance between the upper surface of the platen 22 and the nozzle surface of the ink head 21a, it is assumed that, in a normal state, the distance between the surface of the platen 22 and the ink head 21a is maintained at, for example, the width of Y1. On the other hand, if the position of the center of the eccentric shaft 212 is rotated and displaced by 180 ° with the thick paper placed, Y2 (where Y1 <Y2) is established between the upper surface of the platen 22 and the ink head 21a. Therefore, the variable width of the ink carriage 21 is Y2
−Y1, which corresponds to the difference in thickness between plain paper and thick paper. Usually, the variable width Y2-Y1 = 0.25 to 0.5 mm
It is within the range of about.

FIG. 4C shows the state of the ink carriage 21 during maintenance.

Here, the maintenance step (1),
In (3) and (4), even if the interval between the cleaning head 31a of the maintenance unit 31 and the ink head 21a varies, the influence is small and a sufficient cleaning operation can be performed. However, in the maintenance process (2), since the elastic blade (FIG. 7) 31b of a predetermined height provided in the maintenance unit 31 is used, the above-mentioned balance balance has a great effect on the cleaning operation.

Specifically, the contact state of the elastic blade 31b with the ink head 21a is adjusted in accordance with the height relationship between the ink carriage 21 and the maintenance unit 31 in the case of plain paper. Therefore, the elastic blade 31b comes into contact with the surface of the ink head 21a in an optimally bent state, so that the contact pressure is also constant at an optimal value,
As a result, dirt can be effectively cleaned from the surface of the ink head 21a.

However, in the case of the thick paper shown in FIG.
The ink carriage 21 itself is elevated by Y2-Y1 by the eccentric shaft 212, but at the maintenance position, the height of the ink carriage 21 is
e and the eccentric shaft 212, the interval Y2-Y1 increases between the cleaning head 31a and the ink head 21a even if the maintenance unit 31 is raised by a predetermined stroke. Therefore, the elastic blade 31b cannot contact the surface of the ink head 21a in a sufficiently bent state. For this reason, the contact pressure of the elastic blade 31a becomes smaller than the optimum value, so that it is not possible to reliably wipe dirt from the surface of the ink head 31a, and the cleaning performance is reduced.

This deterioration of the cleaning performance is caused not only by defective cleaning of the ink heads 21a but also by color mixing of the inks, especially in the case where a plurality of ink heads 21a are arranged. Will do.

Therefore, as shown in FIGS. 8 and 9, the guide groove-shaped portion 41 of the guide member 30 is provided with a high level area 41a near the opening side in the main scanning direction and a low level area 41a near the back end side in the main scanning direction. It is formed in a step shape having an inclined step 41c between itself and the level region 41b.

Thus, even if the distance between the paper P and the ink head 21a increases due to the eccentric shaft 212, only a small distance occurs between the nozzle surface of the ink head 21a and the maintenance unit 31 at the maintenance position. Therefore, the cleaning head 31a of the maintenance unit 31 and the ink head 21a of the ink carriage 21 can be reliably brought into opposing contact, and a more favorable cleaning operation can be performed.

The width of the guide groove 41 in the height direction is not particularly limited as long as the width is such that the protrusion 21e on the ink carriage 21 side can be fitted. Usually protrusion 2
Since the diameter of 1e is about 3 to 5 mm, if the diameter is about 0.1 to 0.2 mm larger than this, the protrusion 21e
Can be easily fitted, and the projection 21e in the fitted state can be reliably held by the guide member 41.

The step 40c in the guide groove 41 is
It is preferable that the height does not change so sharply. If the step 40c is sharp, it is difficult to smoothly move the projection 21e in the fitted state from the high-level area 41a to the low-level area 41b smoothly. There is a possibility that it will be distorted and be caught by the step 41c.

The step 41c has a specific inclination of 15 °.
It is preferred that: The height change of the step 41c is about Y2-Y1 = 0.25 to 0.5 mm, but if the inclination angle is 15 ° or less, the fitted projection 21e can easily change this height. , And can be cleared smoothly.

In the above configuration, the height position level of the ink carriage 21 changes with the displacement of the eccentric shaft of the eccentric shaft 212 and the first to third movable arms 511
513 are displaced, and the position of the guide member 40 changes.

As described above, when the height position of the guide member 40 changes in response to the change in the height position of the ink carriage 21, thick paper thicker than plain paper is used as the paper P. Will be.

Therefore, at the time of maintenance of the ink head 21a, as shown in FIG. 12, the ink carriage 2 fitted in the high-level area 41a of the guide groove 41 is formed.
The projection 21e on one side moves to the low-level region 41b in the guide groove 41. With the movement of the projection 21e, the height position level of the ink head 21 changes by E2.

On the other hand, when the eccentric shaft 212 is in the eccentric position state, the height position level of the ink carriage (ink head) 21 changes by E1, but the step amount (high) of the step 41c of the guide groove portion 41 is changed. E2 is the E
1 (E1 = E2). For this reason, even if the position level of the entire ink carriage 21 changes by E1, at the time of maintenance, the height by E1 = E2 is canceled by the guide member 40, so that the maintenance unit 31 only strokes at the predetermined height D. Even
As in the case of plain paper, the cleaning head 31a and the nozzle surface of the ink head 21a can come into contact with each other. As a result, a better cleaning operation can be performed.

Here, the guide groove portion 4 of the guide member 40
Since the ink carriage 21 is formed in the direction along the guide rail 211, as shown in FIG. 12, when the ink carriage 21 moves from the high level area 41a to the low level area 41b, the ink carriage 21 deviates from the maintenance unit 31 by the width F. Will be. Therefore, as shown in FIG.
1 and the tension coil spring 522 adjust the position of the guide member 40.

Specifically, when the position of the guide member 40 on the movable arm 521 side rises, the slope 5 of the fixed cam body 21
The distance between the upper surface of the mounting plate 514 and the upper surface of the mounting plate 514 is gradually reduced. Here, the upper corner portion Q of the guide member 40 is fixed to the fixed cam body 521 by the spring force of the tension coil spring 522 at all times.
The guide member 40 is pushed out in a direction away from the third movable arm 513 side as the distance between the opposing surfaces is reduced. As a result, the guide member 40 moves by the width F, so that the deviation between the maintenance unit 31 and the ink carriage 21 is offset.

On the other hand, when the third movable arm 513 descends and returns to the original position, the distance between the slope 521a of the triangular pyramid 521 and the upper surface of the mounting plate 514 gradually increases, and the guide member 40 is pulled. Due to the spring force of the coil spring 522,
It is drawn to the third movable arm 513 side. As a result, the guide member 40 moved by the width F returns to the original position.

The adjusting mechanism 100 is not limited to the configuration of the above embodiment. That is, the interval between the ink head 21a and the paper P is adjusted to stabilize print quality, and when the maintenance unit 31 cleans the ink head 21a, the ink head 2
It is sufficient that the distance between the cleaning head 31a of the maintenance unit 31 and the nozzle surface of the ink head 21 can be adjusted in accordance with the adjustment of the distance between the sheet 1a and the sheet P.

According to the above-described configuration, the adjusting mechanism 100 has a simple configuration with respect to the current ink-jet printer, and ensures that the adjusting head 100 is positioned between the ink head 21a and the paper P and between the ink head 21a and the cleaning head 31. Since the interval can be adjusted, a higher-quality image can be printed.

[0083]

According to the present invention, the following effects can be obtained.

(1) Since the adjusting mechanism for adjusting the interval between the ink head and the sheet also functions as the adjusting mechanism for adjusting the interval between the ink head and the cleaning head of the maintenance unit, the interval between the ink head and the sheet is adjusted. In addition, the distance between the ink head and the cleaning head of the maintenance unit is adjusted. Therefore, the ink head is appropriately opposed to the cleaning head, the ink head can be reliably cleaned, and the quality of an image printed on paper can be improved.

(2) Since the adjusting mechanism can adjust the interval between the ink head and the sheet to be constant according to the thickness of the sheet, the interval between the ink head and the sheet can be adjusted to be constant according to the thickness of the sheet. The distance between the ink head and the cleaning head is adjusted accordingly, so that the distance between the ink head and the cleaning head can be more accurately maintained, and the effect of cleaning the ink head is further enhanced. be able to.

(3) Since the position of the ink carriage in the direction in which the ink head and the paper surface are arranged is made variable by the rotation of the eccentric shaft in the adjusting mechanism, the ink can be obtained simply by rotating the eccentric shaft. The position of the carriage can be easily changed.

(4) The adjusting mechanism is a guide member for adjusting the position of the entire ink carriage so that the ink head and the cleaning head of the maintenance unit are substantially opposed to each other at a predetermined interval when the ink carriage reaches the maintenance position. When the ink carriage reaches the maintenance position, the distance between the ink head and the paper,
In addition, the distance between the ink head and the cleaning head is appropriately set, and therefore, the cleaning of the ink head by the cleaning head can be reliably performed.

(5) The ink carriage has a projection protruding in the sub-scanning direction, and the guide member is formed with a guide groove-shaped portion for fitting the projection of the ink carriage in the scanning direction. The guide groove-shaped portion is formed in a stepped shape in which the position of the ink carriage can be changed via the protrusion in accordance with the protrusion fitting position in the scanning direction, so that the protrusion of the ink carriage is formed in the guide groove-shaped portion of the guide member. When fitted, the position of the ink carriage in the arrangement direction of the ink head and the cleaning head changes via the protrusion according to the fitting position of the protrusion in the scanning direction. Therefore, the distance between the ink head and the cleaning head can be adjusted more accurately.

(6) Since the amount of change in the position of the ink carriage adjusted by the adjustment mechanism and the amount of step in the guide groove-shaped portion of the guide member are set to be substantially equal, the change in the position of the ink carriage can be offset. This makes it possible to reliably clean the ink head.

(7) The adjusting mechanism has an interlocking means for changing the position of the guide member in conjunction with the eccentric shaft for changing the position of the ink carriage. In the position, it is returned by the interlocking means via the guide member. As a result, the displacement of the facing position between the ink head and the maintenance head is corrected, and the cleaning can be performed more accurately.

(8) The interlocking means adjusts the position of the guide member in the direction in which the ink head and the cleaning head are arranged.
Since the position adjustment unit is provided to correspond to the change in the position of the ink carriage, the position of the guide member, which has been changed due to the eccentricity of the eccentric shaft, is adjusted by the position adjustment unit. The distance from the ink head can be adjusted more appropriately.

(9) The position adjusting section links the eccentric shaft side and the guide member with each other, and transmits a change in the height position level due to the eccentricity of the eccentric shaft to the guide member. , The position of the movable arm of the position adjustment unit varies when the position is changed due to the rotation of the eccentric shaft, and the change is transmitted to the guide member via the movable arm. Therefore, the position of the ink carriage can be appropriately set by the position adjustment unit having a relatively simple configuration.

(10) Since the interlocking means is provided with a scanning direction position adjuster for moving the guide member in the main scanning direction, the position of the ink head is adjusted by the guide member. Even if the position in the scanning direction is displaced, the guide member is displaced in the scanning direction by the scanning direction position adjusting action, so that the displacement can be offset.

(11) The scanning direction position adjustment unit displaceably mounts the guide member on the mounting plate held by the movable arm, and adjusts the fixed cam body in accordance with the displacement of the movable arm in the height direction. By controlling the displacement of the guide member in the scanning direction by the inclined surface, the position of the guide member in the scanning direction can be surely adjusted while having a simple configuration.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of an ink jet printer according to an embodiment of the present invention.

FIG. 2 is a side view of the ink carriage.

FIG. 3 is a side view of an eccentric shaft which is one of support members of the ink carriage.

FIG. 4 is an explanatory diagram of height adjustment of an ink carriage.

FIG. 5 is a side view of a positional relationship between the ink carriage and the maintenance unit.

FIG. 6 is a side view illustrating a state where the ink head of the ink carriage is in contact with the cleaning head of the maintenance unit.

FIG. 7 is an explanatory diagram of a facing distance between an ink head of an ink carriage and a cleaning head of a maintenance unit.

FIG. 8 is an external perspective view of a guide member.

FIG. 9 is a side view of an arrangement state of a guide member.

FIG. 10 is a side view of a scanning direction position adjustment unit in the adjustment mechanism.

FIG. 11 is a front view of an interlocking means in the adjustment mechanism.

FIG. 12 is an operation explanatory view of a main part of the adjustment mechanism.

[Explanation of symbols]

 Reference Signs List 21-Ink carriage 21a-Ink head 21e-Protrusion 31-Maintenance unit 31a-Cleaning head 40-Guide member 41-Guide groove 50-Interlocking means 51-Height position adjuster 52-Scan direction position adjuster 100-Adjustment Mechanism 211-Support (guide rail) 212-Support (eccentric shaft) 511, 512, 513-Movable arm 514-Placement plate 521-Fixed cam body 521a-Slope 522-Spring member A-Scanning direction C-Sub Scanning direction P-paper

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Yuhi Akakawa 22-22, Nagaikecho, Abeno-ku, Osaka-shi, Osaka Inside Sharp Corporation (72) Inventor Kazuya Koyama 22-22, Nagaikecho, Abeno-ku, Osaka-shi, Osaka Incorporated F term (reference) 2C056 EA16 EC08 EC13 EC23 EC33 FA10 HA12 JB04 JB08 JC20 2C064 CC04 CC05 CC11 DD13 EE17

Claims (11)

[Claims] An ink carriage mounted with an ink head facing a paper surface and moved in a main scanning direction; an adjusting mechanism for displacing the ink carriage to adjust an interval between the ink head and the paper surface; and a main scanning direction. And a cleaning head disposed at a predetermined position of the ink jet printer, wherein the adjustment mechanism also functions as an adjustment mechanism for adjusting a distance between the ink head and the cleaning head. 2. The ink jet printer according to claim 1, wherein the adjusting mechanism adjusts a distance between the ink head and the surface of the paper to be constant according to a thickness of the paper. 3. The adjusting mechanism includes an eccentric shaft, which is a support for moving the ink carriage in the scanning direction, and adjusts the distance between the ink head and the surface of the paper by rotation of the eccentric shaft. The inkjet printer according to claim 1 or 2, wherein 4. The cleaning mechanism according to claim 1, wherein the cleaning head is disposed at a maintenance position set at an end of the movable support, and the adjusting mechanism moves the ink head and the cleaning head to a predetermined position when the ink carriage reaches the maintenance position. 4. The ink jet printer according to claim 3, further comprising a guide member for displacing the ink carriage so as to be opposed at intervals. 5. The guide member includes a projection projecting from the ink carriage in the sub-scanning direction and a guide groove in the main scanning direction into which the projection of the ink carriage is fitted. The ink jet printer according to claim 4, further comprising: a guide groove whose fitting position changes in the main scanning direction. 6. The adjusting mechanism according to claim 1, wherein the amount of displacement of the ink carriage, which is adjusted by the rotation of the movable support, and the amount of change in the fitting position of the projection in the arrangement direction of the ink head and the cleaning head in the guide member. The ink jet printer according to claim 5, wherein the same amount is set. 7. The ink jet printer according to claim 4, wherein said adjusting mechanism includes an interlocking means for operating a guide member in conjunction with rotation of the eccentric shaft. 8. The apparatus according to claim 1, wherein the interlocking means adjusts a position of the guide member in a direction in which the ink head and the cleaning head are arranged.
The ink jet printer according to claim 7, further comprising a position adjustment unit that corresponds to a position of the ink carriage in a direction in which the ink head and the sheet surface face each other. 9. A plurality of position adjusters for coupling between the eccentric shaft side and the guide member to transmit a change in height position level due to eccentricity of the eccentric shaft to the guide member. The inkjet printer according to claim 8, further comprising a movable arm. 10. The ink jet printer according to claim 8, wherein said interlocking means includes a scanning direction position adjusting section for displacing the guide member along the main scanning direction. 11. A scanning plate, comprising: a mounting plate that is held by a movable arm that is displaced in a direction opposite to an ink head and a paper surface and that displaces a guide member in a main scanning direction; A fixed cam body having an inclined surface whose distance from the upper surface of the mounting plate increases with distance from the movable arm in the direction, and an elastic member for urging the guide member on the mounting plate in a direction of contacting the inclined surface of the fixed cam. The inkjet printer according to claim 10, wherein the position of the guide member in the main scanning direction is controlled by changing the contact position on the slope of the fixed cam according to the displacement of the movable arm.