JP3019037B2 - Printhead for inkjet printer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a print head for an ink jet printer, such as a color printer, in which a plurality of heads having nozzle holes for ejecting ink are mounted in parallel. Prevents ink from entering the gap between
The present invention relates to a print head of an ink jet printer for preventing ink from dripping on recording paper and becoming dirty.

[0002]

2. Description of the Related Art In general, in an ink jet printer, particularly in a color printer or the like, a plurality of heads having nozzle holes for discharging ink are mounted in parallel. Each of the plurality of heads ejects ink of each color to print on recording paper, and the tip of the ejected head is rubbed by a wiper to remove excess ink.

With reference to FIGS. 8 and 9, a print head of such a conventional ink jet printer will be specifically described. FIG. 8 is a perspective view of a print head of a conventional ink-jet printer of this type viewed from the head end side, and FIG. 9 is an enlarged plan view of the print head end portion shown in FIG.

As shown in these figures, a print head of a conventional ink jet printer has a first head 101 and a second head 10 having nozzle holes for discharging ink.
The second and third heads 103 are arranged in parallel and attached to the head fixing portion 107, and are movable in the printing direction by a carriage (not shown).

The first, second and third heads 101, 1
The nozzle plates 02 and 103 are fixed to the head fixing unit 107 at a predetermined interval as shown in FIGS. 8 and 9, and a nozzle plate provided with a nozzle hole for discharging ink at the tip of each head. 104, 105 and 106 are attached.

The first, second and third heads 1
A thin plate-shaped wiper 109 made of a flexible member is disposed on a movement line outside the print area of 01, 102, 103, and the tip of the wiper 109 is moved by the carriage to each head of the print head. It comes into sliding contact with the tip.

[0007] The print head of the conventional ink jet printer having the above-described structure is composed of print heads 101, 102,
103 discharges ink through each of the nozzle plates 104, 105, and 106 to perform printing on a recording paper (not shown).

After the printing, the print head moves to a position outside the printing area where the wiper 109 is provided, and the leading ends of the heads 101, 102, and 103 slide on the wiper 109 as shown in FIG. , Each nozzle plate 10
Excess ink adhering to 4, 105, 106 is wiped off. As a result, unnecessary ink is removed from the tip of the print head, and the tip of the head is always kept clean.

[0009]

However, the print head of such a conventional ink jet printer has a plurality of heads 10 as shown in FIGS.
Reference numerals 1, 102, and 103 are fixed to the head fixing portion 107 at fixed intervals, and a fixed gap exists between each head.

For this reason, the wiper 9 for wiping the ink is used.
Moves between the heads, the leading end of the wiper 9 instantaneously enters the gap between the heads (see FIG. 9), leaving ink on the side surface of the head. The ink drops on the recording paper, and the recording paper becomes dirty.

As described above, in the conventional ink jet printer, since there is a gap between the plurality of heads,
The ink adhering to the wiper enters this gap, and the ink drips on the recording paper to be printed later, causing a problem of causing printing stains.

Here, it is also considered to make the gap between the heads zero. However, from the viewpoint of printing accuracy, it is necessary to suppress the pitch between nozzles of each head to the order of microns.
For this reason, in order to mount a plurality of heads in close contact with each other without any gap, the dimensional accuracy of the nozzle position and the head outer shape must be suppressed to the order of microns. This is extremely difficult in terms of head manufacturing, and the manufacturing cost is extremely high. In practice, it is considered difficult to completely eliminate the gap between the heads.

Furthermore, in the conventional ink jet printer, since the nozzle plate attached to the tip of the head is in a bare state, there is a problem that the nozzle plate may be peeled off due to a recording paper jam or the like. there were.

Japanese Patent Application Laid-Open No. Hei 4-235054 discloses a nozzle protection plate in which a head surface around a nozzle of an ink head is formed in a concave shape and a slit hole is formed to surround the periphery of the concave head surface. In addition, a head holder for holding the outer peripheral edge of the nozzle protection plate is provided, and an ink jet recording apparatus is proposed in which a concave portion is formed stepwise around the nozzle of the head to prevent damage to the nozzle due to recording paper jam. Have been.

According to the ink jet recording apparatus disclosed in Japanese Patent Application Laid-Open No. Hei 4-235054, the periphery of the nozzle protrudes stepwise by a plurality of recesses formed in the head, and even if a jam occurs, the recording paper may come into contact with the nozzle. Not
The nozzle can be prevented from being damaged by the recording paper.

However, the apparatus disclosed in Japanese Patent Application Laid-Open No. Hei 4-235054 is intended for an ink jet printer having a single print head, and in the case where a plurality of heads are provided in parallel like a color printer. However, this does not solve the problem of ink entering between the heads.

Also, if the head proposed in Japanese Patent Application Laid-Open No. Hei 4-235054 is applied to an ink jet printer having a plurality of heads, the periphery of the nozzles of each head protrudes in a stepwise manner. In addition to the gap, the ink adhering to the wiper is scraped off not only at the stepwise protruding portion but also at the risk of increasing the amount of ink accumulated in the head portion.

The present invention has been proposed in order to solve such problems of the prior art, and the gap between the heads at the time of cleaning the nozzle surface is determined only by a simple, small, and lightweight structure. It is an object of the present invention to provide a print head of an ink jet printer which can prevent ink from entering into a recording paper, effectively prevent ink from dripping on recording paper and becoming dirty, and also prevent peeling of a nozzle plate.

[0019]

According to a first aspect of the present invention, there is provided a print head for an ink jet printer, comprising: a plurality of heads each having a nozzle hole for discharging ink at a leading end thereof; Ru is disposed Te
And a member that covers a gap between the plurality of heads.
In the printer head of the inkjet printer,
A member that covers a gap between the plurality of heads is attached to the plurality of heads.
Heads of the plurality of heads.
It is a plate-like member that covers integrally and has a position corresponding to each head.
Plate with nozzle holes for ink discharge
The inkjet printer according to claim 2,
In the print head of Linter, this nozzle plate is
A plurality of plate members are arranged on the same plane.

According to such a print head of an ink jet printer of the present invention having the structure, it is possible to cover a gap between the plurality of heads by a nozzle plate provided in the head tip, other members, means or the like separately Without providing, a gap between a plurality of heads can be covered only by a very simple and small member such as a nozzle plate, thereby preventing ink from entering the gap between the heads when cleaning the nozzle surface. Can be.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a print head of an ink jet printer according to the present invention will be described below with reference to the drawings. First, a reference embodiment of a print head of an ink jet printer according to the present invention will be described with reference to FIGS. FIG. 1 is a perspective view of a print head of an ink jet printer according to a reference embodiment, as viewed from the head end side, and FIG. It is the whole perspective view seen. FIG. 3 is an enlarged cross-sectional plan view of a main part of a tip end portion of the print head shown in FIG.

[0022] Incidentally, the print head of an ink jet printer of the present embodiment shown in these figures has a feature in that the cover head tip with a cover 8 as described below, for other parts, It has almost the same configuration as the print head of the conventional inkjet printer shown in FIG.

As shown in FIG . 1, the print head of the ink jet printer according to the present embodiment has a first head 1, a second head 2, and a third head 3 having nozzle holes for discharging ink, which are arranged in parallel. And is movable in the printing direction by a carriage 12 to be described later.

[0024] The first, second and third head 1, 2, 3,
As shown in FIG. 3, they are arranged at predetermined intervals and fixed to the head fixing part 7. At the tip of each head,
First, second, and third nozzle plates 4, 5, and 6 each having a nozzle hole for discharging ink are provided.

In this embodiment, a cover 8 is provided as a member for covering the gap between the first and second heads 1 and 2 and the gap between the second and third heads 2 and 3. The cover 8 integrally covers the front end sides of the heads 1, 2, and 3, and also covers the nozzle plates 4 of the heads 1, 2, and 3.
Window holes 8a, 8b and 8c from which the nozzle holes 5 and 6 are exposed are formed by punching or the like.

The window holes 8a, 8b, 8c of the cover 8
Are formed smaller than the outer shapes of the nozzle plates 4, 5, and 6, and the entire cover 8 is sized to cover the ends of the outer shapes of the nozzle plates 4, 5, and 6 after being attached to the head. I have. Thus, by providing the cover 8, the gap between the heads can be covered, and the nozzle holes are exposed to the outside by the window holes 8a, 8b, 8c, and printing can be performed freely.

[0027] Here, the cover 8 of the embodiment, in consideration of the rigidity, is formed by the aperture of the metal plate. The thickness of the cover 8 is desirably as thin as possible so that the ink attached to the wiper 9 is not scraped off by the step between the head end surface and the cover 8 as described later. 0.1-0.2 in form
mm. The cover 8 can be formed by means of a metal plate made of a copper plate or the like or by plastic molding or the like.

In the present embodiment, an inclined surface extending toward the tip of the head is further formed at the edge of each of the window holes 8a, 8b, 8c of the cover 8. Specifically, as shown in FIG. 3, the ends of the window holes 8a, 8b, and 8c of the cover 8 have surfaces that do not face the nozzle plates 4, 5, and 6,
That is, an inclined surface is formed by chamfering by post-processing or the like so as to spread to a surface facing the recording paper 11 when the print head is mounted on the printer body.

In this embodiment, since the cover 8 is provided at the head end, a step is formed between the head end surface and the edge of each of the window holes 8a, 8b, 8c by the thickness of the cover 8. . Therefore, by providing an inclined surface at the edges of the window holes 8a, 8b, 8c, the corners of the window hole edges are eliminated, and as will be described later, the ink adhered to the wiper 9 may be scraped off by steps. I try not to.

The configuration for removing the corners of the edges of the window holes 8a, 8b, 8c is not limited to the formation of the inclined surface, but may be, for example, the window holes 8a, 8b, 8 of the cover 8.
The edge of c may be formed in a curved shape so as to have a so-called sagging surface, and may have any shape as long as the ink attached to the wiper 9 is not scraped off.

[0031] Then, the print head having such a configuration, as shown in FIG. 2, is driven along a guide shaft 13 mounted on the carriage 12. on the other hand,
A recording paper 11 is arranged on the side facing the head end, and the recording paper 11 is fed by a paper feed roller 14.
The paper is conveyed in a direction orthogonal to the moving direction of the carriage 12 and printed by the head.

As shown in FIG. 2, a head cleaning mechanism 15 is provided outside the printing area on the movement line of the print head.
5, a wiper 9 protrudes from the upper surface side. The wiper 9 is formed in a thin plate made of a flexible member.
It comes into sliding contact with each head end of the print head moved by the carriage 12.

[0033] This wiper 9, the surface of the nozzle plate 4, 5 and 6 the print head is adapted to be cleaned. That is, in the case of an ink jet printer, if ink adheres to the nozzle surface during printing, there is a risk of causing a printing failure. During printing, the head moves out of the printing area and the nozzle surface is rubbed by the wiper 9, and the nozzle surface is Ink is wiped off.

Next, the operation of the print head of an ink jet printer according to the present embodiment having such a configuration. First, when a print command is sent from a control unit (not shown), the leading end of the recording paper 11 is sucked and conveyed to a printing start position.

At this time, the print head is waiting outside the printing area, and thereafter driven by the carriage 12 along the guide shaft 13 to perform a reciprocating operation in a direction orthogonal to the feeding direction of the recording paper 11 to perform printing. Start. In the print head moved by the carriage 12, the heads 1, 2, and 3 eject ink through the nozzle plates 4, 5, and 6, and perform printing on the recording paper 11.

[0036] Then, the print head after printing is moved to a position where the print area outside of the wiper 9 is arranged, the tip of each head 1, 2, and 3 in sliding contact with the wiper 9, the nozzle plate 4, 5 , 6 are removed. As a result, unnecessary ink is removed from the tip of the print head, and the tip of the head is always kept clean.

[0037] The cleaning operation, as shown in FIG. 3, the print head is performed by moving the upper wiper 9, the wiper tip corner portion nozzle plates 4, 5,
Rub the surface of No. 6 and wipe off the ink adhering to the surface.
In the present embodiment, since the gap between the heads is covered by the cover 8, even when the wiper 9 moves from the nozzle plate 6 to 5 and from 5 to 4, the ink adhered to the wiper 9 Does not enter the gap between the heads.

In this embodiment, since the cover 8 is attached to the tip of the head, a step is formed between the nozzle plates 4, 5, 6 and the cover 8 by the thickness of the cover 8 as described above. Then, there is a possibility that the ink attached to the wiper 9 is scraped off due to this step.

[0039] Therefore, in this embodiment, as described above, by chamfering the thickness of the cover 8 as well as thin as 0.1 to 0.2 mm, and each window hole 8a, 8b, the edges of 8c, inclined A surface is formed. by this,
There are no corners in the square window holes 8a, 8b, 8c of the cover 8,
No ink is scraped off.

[0040] Thus, according to the print head of an ink jet printer according to the present embodiment, the head tip, by covering with a cover 8 having window holes 8a, 8b, the 8c, covering the gaps between the heads be able to. Thereby, the gap between the plurality of heads can be covered only by the very simple and small member such as the cover 8,
When the nozzle surface is cleaned by the wiper 9, ink can be prevented from entering the gap between the heads, and the ink can be prevented from dripping on the recording paper 11 and becoming dirty.

Further, since the entire head is covered by the cover 8, a nozzle plate 4, 5 and 6 attached to the head tip, since the outer peripheral edge portion is pressed by the cover 8, the jam of the recording paper 11 is generated Also in this case, the separation of the nozzle plates 4, 5, and 6 is effectively prevented.

[0042] Further, since in this way are to cover by the cover 8 the gaps between the heads, to have a gap between the heads, the dimensions of the nozzle position and the head contour can to some extent be rough, The distance between nozzles of each head can be adjusted by adjustment.

In this embodiment, three heads are used. However, as long as a plurality of heads, such as two or four or five, are provided, any number of heads can be used. Can be applied.

Next, a description will be given of another reference embodiment of a printhead of an ink jet printer of the present invention with reference to FIGS. FIG. 4 is a perspective view showing the print head of the ink jet printer according to the present embodiment , as viewed from the head end side, and FIG. 5 is an enlarged plan view of a main part of the end portion of the print head shown in FIG. .

As shown in these figures, this embodiment is a modified embodiment of the above-described reference embodiment, in which the shape of the cover 8 is changed, and the window holes 8a and 8a adjacent to the cover 8 are formed.
The portions b and 8b and 8c are buried in the gaps between the heads. The embedded portion of the cover 8 is formed so as to be flush with the tip surface of the head. Other components are the same as those of the reference embodiment.

[0046] Specifically, as shown in FIG. 4, the cover 8 of the embodiment, the adjacent window holes 8a and 8b and 8b 8
The part dividing c is fitted into the gap between the heads. As shown in FIG. 5, the portions that fit in the gaps between the heads are formed so as to be flush with the tip surfaces of the nozzle plates 4, 5, and 6 of each of the heads 1, 2, and 3.

[0047] By thus constructing the cover 8, as shown in FIG. 5, there is no difference in level between the nozzle plate 4,5,6 and the cover 8 is also attached to the cover 8 occurs, the wiper by the step The ink attached to 9 is not scraped off.

[0048] The cover 8 of the present embodiment described above
Since a portion that partitions an adjacent window hole is buried without any gap between the heads, and since the portion needs to be formed so as to be flush with the head tip surface, a resin molded product having elasticity is used. It is desirable to form the cover 8. Further, according to such a resin molding means, the cover 8 according to the present embodiment can be easily formed with high accuracy.

[0049] [Embodiment will now be described with reference to FIGS. 6 and 7 for the embodiment of the print head of an ink jet printer of the present invention. FIG. 6 is a perspective view showing the print head of the ink jet printer according to the embodiment of the present invention, as viewed from the head end side, and FIG. 7 is an enlarged plan view of the print head end part shown in FIG.

Referring to FIG . 6, the ink jet printer of this embodiment is shown.
The print head of the inkjet printer is provided with a first head 1, a second head 2, and a third head 3 for discharging ink, and the first and second heads having nozzle holes for discharging ink are provided on the tip surface of each head. Second and third nozzle plates 4, 5, and 6 are attached. The heads 1, 2, 3 are arranged in parallel with an arbitrary gap, and attached to the head fixing member 7.

In this embodiment, the nozzle plates 4, 5, and 6 are used as members for covering the gap between the plurality of heads 1, 2, and 3. That is, the nozzle plates 4, 5, and 6 of the present embodiment are disposed on the tip end side of the head and integrally cover the tip end face side of the head.
More specifically, as shown in FIG. 7, in the present embodiment, three nozzle plates 4, 5, and 6 form the same plane, and are integrally attached to the head end surface.

[0052] Then, the three sheets of the nozzle plate 4,
Reference numerals 5 and 6 denote third nozzle plates 6 attached to the third head 3, which are attached across the second head 2 adjacent to the third head 3, and attached to the second head 2. A two-nozzle plate 5 is mounted across the first head 1 adjacent to the second head 2.

[0053] In this way three pieces of the nozzle plate 4, 5,
By arranging the nozzles 6 so as to straddle the adjacent heads, the seam of each nozzle plate is located at the head end face, so that the gap between the heads is covered and ink is prevented from entering. In this embodiment, the nozzle plate is constituted by three nozzle plates 4, 5, and 6. However, the nozzle plate may be constituted by one or two plate members.

[0054] Thus, according to the print head of an ink jet printer of the present embodiment, each of the heads 1 by the nozzle plate 4, 5 and 6 provided in the head tip,
It is possible to cover the gap between the 2 and 3, without providing another member or means, only by a very simple and compact element of the nozzle plate, it is possible to cover a plurality of gaps between the head nozzle surface When cleaning
Prevent ink from getting into gaps between heads
Can be.

[0055]

As described above, according to the print head of the ink jet printer of the present invention, the ink enters the gap between the heads when cleaning the nozzle surface only by the simple, small, and lightweight structure. This can effectively prevent ink from dripping on the recording paper and becoming dirty, and also prevent peeling of the nozzle plate.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a print head of an ink jet printer according to a reference embodiment of the present invention, as viewed from the head end side.

FIG. 2 is an overall perspective view showing a drive structure of a print head of an ink jet printer according to a reference embodiment of the present invention, as viewed from the upper surface side of a carriage.

FIG. 3 is an enlarged plan view of a cross section of a main part of a leading end portion of the print head shown in FIG. 1;

FIG. 4 is a perspective view showing a print head of an inkjet printer according to another reference embodiment of the present invention, as viewed from the head end side.

5 is an enlarged cross-sectional plan view of a main part of a leading end portion of the print head shown in FIG.

FIG. 6 is a perspective view showing a print head of the ink jet printer according to the embodiment of the present invention, as viewed from a head end side.

FIG. 7 is an enlarged plan view of a tip portion of the print head shown in FIG.

FIG. 8 is a perspective view showing a print head of a conventional ink jet printer, viewed from the head end side.

FIG. 9 is an enlarged plan view of the tip of the conventional print head shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 1st head 2 2nd head 3 3rd head 4 1st nozzle plate 5 2nd nozzle plate 6 3rd nozzle plate 7 Head fixing part 8 Cover 8a Window hole 8b Window hole 8c Window hole 9 Wiper

Claims (2)

(57) [Claims] 1. A head having a nozzle hole for ejecting ink to the tip, Ru are arranged in parallel a plurality at predetermined intervals
In addition, in a print head of an ink jet printer including a member that covers a gap between the plurality of heads, a member that covers a gap between the plurality of heads is attached to the plurality of heads.
Heads of the plurality of heads.
It is a plate-like member that covers integrally and has a position corresponding to each head.
Plate with nozzle holes for ink discharge
A print head for an ink jet printer, comprising: Wherein said nozzle plate, according to claim 1 print head of an ink jet printer according constituted by arranging a plurality of plate-like member on the same plane.