JPH02122933A - Capping device of ink jet printer - Google Patents

Abstract

PURPOSE:To obtain a capping device which prevents a cap from sticking to a printing head defectively and thereby is highly reliable without defects such as ink drying or leakage by providing a hemispherical protrusion on one side of the engagement section between the cap and a cap supporting member, and providing a hemispherical recessed part with a slightly larger diameter than the former, on the other side. CONSTITUTION:If an ink jet head 1 rotates by an angle theta1 against a supporting member 3, a cap fixing frame 5 which fixes a cap 2 comes in contact with the hemispherical protrusion 3c of the cap supporting member, with the hemispherical recessed part 5a of the cap fixing frame. In addition, the cylindrical protrusion 5b of the cap fixing frame moves in a track hole 3b of the cap supporting member, rotating by an angle theta2 which is theta1=theta2. Thus the capping operation is performed. In this case, the force which presses the cap 2 against the ink jet head is transmitted by a contact state between one point on the hemispherical protrusion 3c and one point on the hemispherical recessed part 5a. Subsequently, a deviation in the distribution of a surface pressure on a sealed surface can be minimized.

Description

Detailed Description of the Invention 1 Industrial Applications 1 The present invention relates to an inkjet recording device that records characters, etc. on a recording medium by ejecting ink droplets from a nozzle. The present invention relates to a capping device for an inkjet recording head that prevents staining of peripheral areas due to ink leakage.

1. Prior Art] Conventionally, with respect to a capping device for an inkjet recording apparatus, there has been a method of capping by configuring the cap to be rotatable in only one direction.

Fig. 4 shows its schematic diagram. The cap 2 is rotatably supported by a cap support member 3 at a fulcrum 2a, and the cap support member 3 is rotatable around the fulcrum 3a, and a cam mechanism 5 operates to open and close the cap, so that the cap is closed. In this case, the cap 2 is always pressed against the print head 1 by the tension coil spring 4. For example, even when the print head 1 moves back and forth with respect to the cap 2 as shown by the arrow, the cap support member 3 rotates as shown by the arrow B around the fulcrum 3a, and at the same time, the cap 2 rotates around the fulcrum 2a as shown by the arrow C.
It was designed so that it could be rotated and capped in the same position at all times.

1 Problems and Objectives to be Solved by the Invention 1 However, in the conventional capping device, the cap can only rotate in one direction. This compensates for the deviation in parallelism between the cap and the print head, resulting in an uneven distribution of surface pressure on the contact surface of the cap with the print head.

However, since the width of the cap was narrow in the width direction perpendicular to the direction of rotation of the cap, the desired purpose was achieved with the above method, but the size of the cap was increased in order to arrange multiple rows of nozzles in the print head. When it becomes necessary to
Capping failure occurs due to variations in the posture of the cap, resulting in ink ejection failure due to dryness of ink near the nozzle, and electron n f due to ink leakage from the cap.
This had the problem of causing contamination within H. Another problem is that if the posture of the cap varies when capping, it is difficult to perform capping in a stable manner each time.

Therefore, the present invention aims to solve these problems.
The purpose is to provide an extremely reliable capping device for an inkjet printer that prevents poor adhesion of the cap to the print head and prevents ink drying, ink leakage, etc.

[Means for Solving the Problems J] The capping device for an inkjet printer of the present invention is such that the cap made of an elastic material that covers the ink jet nozzle portion of the print head is fixed in only one direction with respect to the cap support member that locks the cap. It is characterized by being capable of rotational movement not only in rotation but also in other directions, such as a direction perpendicular to rotation. Specifically, one of the engagement parts between the cap and the cap support member is provided with a hemispherical convex part, and the other part is provided with a hemispherical concave part with a slightly larger radius.

Furthermore, a spring is applied between the cap and the cap support portion, and the posture of the cap is kept constant by the force of the spring.

[Function 1] According to the above configuration of the present invention, even if the parallelism between the abutting surface of the cap and the abutting surface of the print head is not accurately obtained, as the cap is pressed against the print head, the abutment of the cap is achieved. The surface makes an oscillating motion due to the action of the hemispherical convex portions and concave portions, and accurately comes into close contact with the print head. In addition, since the pressing force of the cap on the print head is applied to the cap only by the contact points between the hemispherical convex portion and the concave portion, the surface pressure distribution on the contact surface of the cap is almost constant, which prevents ink from drying. Enables stable cabining with no leaks.

Furthermore, by creating a structure in which the cap is kept in a constant position, the cap can be pressed against the print head in the same state at all times, allowing stable cap operation.

[Embodiment 1] A capping device for an inkjet printer according to the present invention will be explained based on the drawings.

FIG. 1 shows an embodiment of the present invention. Reference numeral 5 denotes a cap fixing frame for fixing a cap made of an elastic material such as a rubber material.A hemispherical recess 5a is provided near the center of the cap fixing frame 5. Cylindrical protrusions 5 are provided on both sides of the cylindrical projection 5 for swingably locking the cap fixing frame 5 together with the cap 2.
b.

3 is a cap support member that locks the cap 2 and the cap fixing frame 5, and is provided with a hemispherical convex portion 3C and track holes 3b on both sides of the hemispherical convex portion 3C for swingably locking the cylindrical protrusion 5b. and are engaged as shown in FIG. 6
is a tube leading to a pump device (not shown) that sucks ink through the cap 2. 7 is a tube that leads to a valve (not shown) for communicating and blocking the inside of the cap 2 with the atmosphere.

2 is a side view and a sectional view of the capping device shown in FIG. 1. FIG. As shown in FIG. 2(A), even when the print head 1 moves back and forth with respect to the cap 2 as shown by arrow A, the cap support member 3 rotates as shown by arrow B around the fulcrum 3a, and at the same time, the cap 2 , cap defining frame 5
It is the same as the conventional example that it is configured so that it can be rotated in the direction of arrow C around the protrusion 5b and can be capped in the same posture at all times. Furthermore, in the present invention, as shown in FIG.
As shown in FIG.
Even if only the cap 1 is rotating, the cap 2
The cap fixing frame 5 that fixes the
While touching at a, also touch the cylindrical protrusion 5 of the cap fixing frame.
While moving in the track hole 3b of the cap support member, b rotates by an angle θ2 such that θl=θ2, and is capped as shown in the figure. At this time, the force that presses the cap 2 against the head 1 is transmitted through point contact between one point of the hemispherical convex portion 3C and one point of the hemispherical concave portion 5a.

Therefore, in order to make the surface pressure distribution of the cap 2 uniform,
The hemispherical recess 5a of the cap fixing frame 5 may be placed at the center of the surface of the cap 2 that contacts the head 1.

Furthermore, in this embodiment, the cap support member 3 is provided with a hemispherical convex portion, but the cap support member 3 is provided with a hemispherical concave portion, and the cap fixing frame No. 5 has a hemispherical shape. It goes without saying that the same effect can be obtained when a convex portion is provided.

FIG. 3 shows a second embodiment of the present invention, in which a hook 5d is provided in a part of the cap fixing frame 5, and a cap posture control spring 8 is hung thereto to keep the cap constant. The lower part of the print head 1 is always pulled toward the opposite side of the print head 1. When the cap 2 is not in contact with the print head 1, the cap 2 is in a slightly downward position due to the action of the cap posture M911 spring 8, and in this state, the cap opening/closing mechanism and the tension coil spring (not shown) When the capping operation is performed by the function of 4,
The cap support member 3 rotates in the direction of arrow B and always contacts the print head 1 from the upper end 2a of the sealing surface of the cap 2 to be capped. At this time, if the force of the cap attitude control spring is too strong, the surface pressure distribution on the sealing surface will become uneven, causing defective capping, so the minimum value that allows the attitude of the cap 2 to be controlled is desirable.

[Effect of the Invention 1] As described above, according to the present invention, even if the positional relationship between the print head and the cap member covering it is relatively uneven, there is a mechanism that allows the sealing surface of the cap to be in close contact parallel to the print head. This has the great effect of minimizing the deviation in the surface pressure distribution on the sealing surface. Furthermore, the provision of the cap position control spring has the great effect of making stable capping possible at all times by configuring the cap to maintain a constant position.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing an embodiment of a capping device for an inkjet printer according to the present invention. FIG. 2 is a side view and a sectional view taken along line DD of FIG. 1. FIG. 3 is a side view showing a second embodiment of the invention. FIG. 4 is a side view showing a conventional capping device for an inkjet printer. 1...Print head 2...Cap 3...Cap support member 3C...Semispherical convex portion 5a...Semispherical concave portion 8...Cap attitude control spring and above Applicant: Seiko Epson Corporation Representative Patent Attorney Kisanbe Meiki and 1 other person 7: Go to Yoρ14, Lid 2, Figure 7: Go to Hard Copy, Lid 3

Claims (3)

[Claims] (1) In an inkjet recording device that records characters, etc. on a recording medium by jetting ink droplets from a nozzle, a cap made of an elastic material that covers an ink jet nozzle portion of a print head and a cap support member that locks the cap are used. A capping device for an inkjet printer, wherein the cap is swingable in two or more directions relative to the cap support member. (2) In a capping device for an inkjet printer, one of the engaging parts of the cap and the cap support member has a hemispherical convex part, and the other part has a radius slightly larger than the radius of the hemispherical convex part. 2. The capping device for an inkjet printer according to claim 1, wherein the capping device is provided with a hemispherical recess. (3) A capping device for an inkjet printer, characterized in that a cap attitude control spring is provided between a hook provided on the cap and a hook provided on the cap support member to keep the attitude of the cap constant. Capping device.