JP2750753B2 - Ink jet recording device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording apparatus that performs recording by ejecting recording droplets from a recording head onto a recording medium, and in particular, a recording medium transport mechanism of the inkjet recording apparatus. Related to the structure.

[Conventional technology]

Recording devices such as printers, facsimile machines, and copiers are configured to form an image corresponding to recording information on a recording medium by driving an energy generating unit of a recording head based on the recording information. According to the structure of the recording head, it can be classified into an ink jet type, a wire dot type, a thermal type, a laser beam type, and the like.

In the ink jet type (ink jet recording apparatus), a recording liquid (ink) is supplied to a recording head, and a recording liquid drop (ink droplet) discharging means such as an electrothermal transducer or an electromechanical transducer provided on the recording head is driven. Thus, an image is formed by attaching recording droplets (ink droplets) on a recording medium such as paper or a thin plastic plate.

Usually, a plurality of ink ejection ports are arranged on the front surface of the recording head (the surface facing the recording medium), and a gap of about 0.5 to 1.0 mm is provided between the ejection port surface and the recording medium. I have.

In a color ink jet recording apparatus for performing color recording, for example, a plurality of recording heads corresponding to the number of ink colors such as yellow, magenta, cyan, and black are used.

In a carriage scanning type recording apparatus, these recording heads are usually mounted on a carriage that reciprocates along a recording medium.

The supplied recording medium is conveyed at a predetermined pitch feed to a recording section facing the recording head by a conveying roller driven by a feed motor, and the recorded recording medium is transferred to a pair of rollers disposed downstream of the recording head. (Paper discharge roller).

[Technical problem to be solved by the invention]

In an ink jet recording apparatus of this type, particularly when used in a high-humidity environment or when performing high-density recording, the ink on the recording medium is hard to dry, and the recording medium is transported downstream of the recording head. There is a technical problem that the roller on the recording surface side of the pair of rollers is stained with ink, which is transferred and the recording medium is also stained.

Therefore, in a conventional recording apparatus, a spur having a gear-like shape is usually used as a roller on the recording surface side in order to reduce dirt due to the transfer.

However, even if it is spur, if the ink adheres, there is a technical problem that the ink is transferred to a recording medium, and a stain is attached.

Further, when the spur has no drive, the dirt becomes not a dot but a straight line, and the degree of the dirt may be increased.

The present invention has been made in view of the above-mentioned conventional technical problems, and an object of the present invention is to prevent ink contamination on a recording medium by a conveyance roller on a downstream side of a recording head even when the ink on the recording medium is difficult to dry. It is an object of the present invention to provide an ink jet recording apparatus which can perform the above.

[Means for solving the problem]

In order to achieve the above object, the present invention provides an ink jet recording apparatus which performs recording by discharging recording liquid droplets from a recording head onto a recording medium, wherein a recording surface of the recording medium downstream of the recording head in a recording medium transport direction is provided. A first spur, which is disposed on the side and has a plurality of outwardly projecting projections for contacting and conveying the recording medium, and between the recording head and the first spur, The second spur is disposed on the recording surface side at a position that is not on the same straight line with respect to the recording medium transport direction, and has a plurality of outwardly projecting protrusions for contacting and transporting the recording medium. A spur, and a rotation drive between the first spur and the second spur, the rotatable member being arranged to rotatably engage with both the first spur and the second spur via a water absorbing member. And a rotating body for transmitting force. .

〔Example〕

 Hereinafter, the present invention will be specifically described with reference to the drawings.

FIG. 1 is a schematic longitudinal sectional view showing a main part of an example of an ink jet recording apparatus having a configuration which is a premise of the present invention.

In FIG. 1, the ink jet recording apparatus is configured to perform recording by ejecting recording droplets from a recording head 1 onto a recording medium 2 such as paper or a thin plastic plate.
A platen 3 is arranged at a position facing the recording head 1.

The recording medium 2 is brought into close contact with the platen 3 and conveyed with a gap of, for example, 0.5 to 1.0 mm provided between the recording medium 2 and the ejection port surface of the recording head 1.

On the downstream side of the recording head 1 in the recording medium 2 transport direction,
Roller pairs 4 and 5 for applying a conveying force to the recording medium 2 after recording are arranged.

The roller pairs 4 and 5 are pressed against the front and back of the recording medium 2,
The roller 5 that comes into contact with the surface (recording surface) is constituted by a spur having a gear shape.

Therefore, a water absorbing member 6 as a cleaning member is in contact with a portion of the roller (spur) 5 which comes into contact with the recording surface, that is, the outer peripheral surface.

The water-absorbing member 6 is formed of a sponge-like porous material. In the embodiment shown in FIG. 1, the rectangular parallelepiped water-absorbing member 6 is arranged so that the spur 5 comes into sliding contact with the spur 5.

In this manner, recording is performed by ejecting recording droplets from the recording head 1 onto the recording medium 2, and the recording medium 2 after recording is transported by the pair of rollers 4, 5 on the downstream side of the recording head 1. The ink jet recording apparatus is configured such that the water absorbing member 6 is brought into contact with at least a portion (outer peripheral surface) of the roller 5 on the recording surface side of the roller pair 4 and 5 in contact with the recording surface.

According to the ink jet recording apparatus shown in FIG. 1, at least a portion of the roller 5 on the recording surface side of the pair of rollers 4 and 5 for transporting the recording medium 2 after recording has a water-absorbing member. 6 is brought into contact, the adhered ink transferred from the recording medium 2 to the spur 5 (conveying roller side) can be absorbed by the water-absorbing member 6, so that the ink is transferred onto the recording medium 2 again. Can be prevented.

In this way, even if the ink on the recording medium 2 does not dry out, it is possible to eliminate the ink stain on the recording medium 2 by the transport rollers 4 and 5.

FIG. 2 is a schematic longitudinal sectional view showing a main part of another example of an ink jet recording apparatus having a configuration which is a premise of the present invention.

In the ink jet recording apparatus shown in FIG. 2, the water absorbing member 6 as the cleaning member is formed in a roller shape, and the outer peripheral surface of the water absorbing member 6 is pressed against the outer periphery of the spur 5 so as to be driven to rotate (by a driven roller). ) Structured.

The configuration of FIG. 2 is different from the configuration of FIG. 1 only in this point, and the other portions have substantially the same structure as that of FIG. 1, and corresponding portions are denoted by the same reference numerals, respectively. A detailed description thereof will be omitted.

According to the ink jet recording apparatus shown in FIG. 2, the same effect as described above can be obtained, and the water absorbing member 6 is formed by a driven roller (driven roller). As a result, the spurs 5 come into contact with the spurs 5 and can maintain a high absorption ability even for continuous ink stains.

FIG. 3 is a schematic longitudinal sectional view showing a main part of an embodiment of the ink jet recording apparatus to which the present invention is applied.

In FIG. 3, the inkjet recording apparatus is configured to perform recording by ejecting recording droplets from a recording head 1 onto a recording medium 2 such as paper or a thin plastic plate.
A platen 3 is arranged at a position facing the recording head 1.

The recording medium 2 is brought into close contact with the platen 3 and conveyed with a gap of, for example, 0.5 to 1.0 mm provided between the recording medium 2 and the ejection port surface of the recording head 1.

On the downstream side of the recording head 1 in the recording medium 2 transport direction,
Roller pairs 4 and 5 for applying a conveying force to the recording medium 2 after recording are arranged.

The roller pairs 4 and 5 are pressed against the front and back of the recording medium 2,
The roller 5 that comes into contact with the front surface (recording surface) is constituted by a spur (first spur) having a gear shape.

Further, a rotatable second rotatable member disposed between the recording head 1 and the first spur 5 with a gap of the same degree (for example, 0.5 to 1.0 mm) as the recording head 1 with respect to the recording medium 2. Two spurs 7 are provided.

Therefore, a roller 8 as a rotating body, which is engaged with both the first spur 5 and the second spur 7 and at least a portion engaged with these spurs is formed of a water absorbing member.
But rotatable (like a driven roller or driven roller)
It is pivoted.

The water-absorbing member as the roller 8 can be formed of, for example, a sponge-like porous material.

FIG. 3A shows a state in which the leading end of the recording medium 2 has reached the second spur 7, but has not yet reached the first spur 5, and FIG. 3) shows a state in which the recording medium 2 passes through the pair of rollers 4 and 5 and the recording medium 2 is actively transported by the pair of rollers 4 and 5.

According to the embodiment described above with reference to FIG. 3, the second spur 7 is provided between the recording head 1 and the first spur 5 for conveyance (discharge), so that the recording medium 2 can be more accurately formed. The paper can be discharged while being guided, and a roller 8 as a rotating body for water absorbing cleaning, which is engaged with both the first spur 5 and the second spur 7, is rotatably supported. Therefore, even if the ink on the recording surface is transferred to the second guide spur 7, the ink adhered to the outer peripheral teeth is absorbed by the rollers 8 and transferred to the recording medium 2 again. Absent.

In this way, ink stains on the recording medium 2 due to the second spur 7 can be eliminated.

Further, even when the ink on the recording medium 2 is transferred to the first spur 5 for conveyance, the ink adhered to the outer teeth of the first spur 5 is sucked by the water-absorbing cleaning roller 8. Therefore, the image is transferred to the recording surface again and the recording medium 2
Will not pollute.

As a material of the roller surface of the roller 8, a polyurethane sponge or the like having excellent water absorption performance and drive transmission performance can be used.

FIG. 4 is a plan view showing the arrangement of the first spur 5, the second spur 7, and the rollers 8 as viewed from the line IV-IV in FIG.

As shown in FIG. 4, the first spur 5 and the second spur 7 are displaced by a predetermined amount a so that they do not overlap on a straight line. By dispersing the absorbing portions, the ink absorbing ability of the roller 8 can be maintained for a long period of time, and damage to the water-absorbing member due to spur projections can be suppressed. Will be possible.

Incidentally, in the configuration of FIG.
Is a driving roller, but in the embodiment of the present invention, the first spur 5 can be a driving roller and the discharge roller 4 can be a driven roller.

Further, the second spur 7 for guidance may be used as a drive roller, and the first spur 5 and the paper discharge roller 4 may be rotated by the second spur 7.

Since the rotational driving force is transmitted between the first spur 5 and the second spur 7 by the roller 8 as the rotating body, at least both the first spur 5 and the second spur 7 are recorded. It is possible to prevent the medium 2 from being dragged and rotated, thereby reducing the spur protrusion traces remaining on the recording medium recording surface on the downstream side of the spur.

〔The invention's effect〕

As is apparent from the above description, according to the present invention, in an ink jet recording apparatus that performs recording by discharging recording liquid droplets from a recording head onto a recording medium, the recording medium downstream of the recording head in the recording medium conveyance direction A first spur, which is disposed on the recording surface side and has a plurality of outwardly projecting protrusions for contacting and conveying the recording medium, and between the recording head and the first spur. The first spur is disposed on the recording surface side at a position that is not on the same straight line with respect to the recording medium transport direction, and a plurality of outwardly projecting protrusions for contacting and transporting the recording medium are provided. A second spur, and both the first spur and the second spur, are arranged to rotatably engage via a water-absorbing member, between the first spur and the second spur. A rotating body that transmits the rotational driving force of the rotating body. Therefore, since the second spur is disposed at a position not on the same straight line as the first spur, the portions of the spur that are in contact with the water absorbing member are dispersed to disperse the ink absorbing portions, and By suppressing the damage of the water-absorbing member due to the projections, the water-absorbing member can be used for a long period of time, and the rotating body transmits the rotational driving force between the first spur and the second spur. Therefore, it is possible to prevent at least both the first spur and the second spur from being dragged by the recording medium and rotating, and to reduce the protrusion marks of the spur remaining on the recording medium recording surface on the downstream side of the spur. An inkjet recording device is provided.

[Brief description of the drawings]

FIG. 1 is a schematic longitudinal sectional view showing a main part of an example of an ink jet recording apparatus having a configuration which is a premise of the present invention, and FIG. 2 is another example of an ink jet recording apparatus having a configuration which is a premise of the present invention. FIG. 3 is a schematic longitudinal sectional view showing a main part, and FIG. 3 is a schematic view showing a main part of an ink jet recording apparatus to which the present invention is applied. FIG. 3A shows a state in which the recording medium has not reached a pair of paper ejection rollers. 4B is a longitudinal sectional view showing a state in which the recording medium is being conveyed by a pair of rollers for paper ejection, and FIG. 4 is a first sectional view taken along line IV-IV in FIG. 3A. It is a schematic plan view which shows arrangement | positioning of a spur and a 2nd spur. 1 ... print head, 2 ... print medium, 3 ... platen,
4... Discharge rollers, 5... First spur, 7... Second spur, 8... Roller (water-absorbing member).

Continuing from the front page (72) Inventor Hiroyuki Inoue 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Takashi Nojima 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Shinya Matsui 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Tetsuo Suzuki 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (56) Reference Document JP-A-1-226379 (JP, A)

Claims (1)

(57) [Claims] 1. An ink jet recording apparatus which performs recording by discharging recording liquid droplets from a recording head onto a recording medium, wherein the recording head is disposed on a recording surface side of the recording medium downstream of the recording head in a recording medium transport direction. A first spur provided with a plurality of outwardly projecting protrusions for contacting and transporting the recording medium, and between the recording head and the first spur, wherein the first spur is A second spur that is arranged on the recording surface side at a position that is not on the same straight line with respect to the recording medium transport direction and has a plurality of outwardly projecting protrusions for contacting and transporting the recording medium; A rotation that is rotatably engaged with both the spur and the second spur via a water-absorbing member, and that transmits a rotational driving force between the first spur and the second spur. And an ink jet recording characterized by having: apparatus.