JPH0257375A - Ink jet recorder - Google Patents

Abstract

PURPOSE:To stably convey a recorder while holding it in small size, and to prevent a recording medium from impression marks or contamination from occurring by bringing a suction roller which is drivably transmitted at a relative speed to a pinch roller for holding and conveying the medium under press contact with a conveying roller into contact with the pinch roller. CONSTITUTION:A continuous sheet 5 on a supply side stacker 23 is conveyed from below to above as designated by an arrow B according to a print command, passed between an upper conveying roller 2 and a pinch roller 4, and then discharged on a discharge side stacker 24. In this case, the frictional force with the sheet 5 is generated at the roller 4 to be stably conveyed. Ink liquid which is not yet fixed on the sheet 5 is transferred to the outer surface of the roller 4. On the other hand, a roller 9 is rotated in a direction of an arrow C, effectively with a relative speed at the contact with the roller 4, the ink transferred to the face of the roller 4 is sucked to the roller 9 before circulating one cycle to be wiped off, and the position immediately before the contact of the sheet of the roller 4 is always maintained effectively clean.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an inkjet recording apparatus that records an image on a recording medium using ink liquid.

[Prior Art] Conventionally, inkjet recording apparatuses have been attracting increasing attention in recent years because they have many advantages such as extremely low noise during recording and the ability to record images on plain paper.

Incidentally, since inkjet recording apparatuses use liquid ink, droplets are generally deposited on a recording medium and then dried and fixed. Immediately after recording, the recording medium must be held and transported without contacting its surface.

Conventionally, techniques for this purpose have been shown to ensure that fixing is performed before the recording medium after recording comes into contact with a conveying means (for example, a pair of rollers) for ejecting the recording medium. Examples of methods include providing a waiting time for the transfer, or arranging the transport means at a distance corresponding to the time. However, in this direction, problems such as a decrease in throughput and an increase in the size of the recording apparatus arise.

Further, as a technique for minimizing the contact area with the recording medium, there is a method in which the pinch rollers of the pair of conveyance rollers are replaced with spurs, and only the tips of the spurs are configured to come into contact with the recording medium. However, when using spurs,
Due to the high contact pressure, impressions are left on the recording medium. Furthermore, even if the contact area is small, there is a possibility that ink liquid may adhere to the tip of the spur, and after one spur or one rotation, this adhered ink liquid may transfer to other parts of the recording medium and cause stains.

Therefore, in Japanese Patent Application No. 63-51667 (filed on March 7, 1988), the applicant attached a suction roller to the tip of the spur, and the ink liquid at the tip was absorbed and removed by the suction roller. demonstrated the technology to do so.

The present invention is a further development of the technology described in the specification of JtiJ.

[Means and effects for solving the problems] According to the present invention, a recording medium is pinched and conveyed by pressure contact between a conveyance roller and a pinch roller, and an exchangeable suction device whose drive is transmitted at a relative speed to the pinch roller is provided. By bringing the roller into contact with the pinch roller, dirt on the pinch roller can be wiped away, allowing stable conveyance while keeping the device compact. Furthermore, it is an object of the present invention to provide an inkjet recording apparatus that can prevent impressions and stains on a recording medium and can always record good images.

[Example] The present invention will be explained below with reference to Examples.

FIG. 1 is a schematic perspective view of a color inkjet line recording apparatus using the present invention. Further, FIG. 2 is a schematic perspective view of the discharged sheet conveyance section, and FIG. 3 is a side view of the discharged sheet conveyance section.

In FIG. 1, the sheet feeding mechanism of the line recording device is as follows:
A pair of rollers 2 are arranged on a chassis (not shown) at a predetermined distance below L, pinch rollers 3A and 3B are releasably pressed against the circumferential surface of the lower conveying roller 1, and the circumferential surface of the upper conveying roller 2. It is composed of pinch rollers 4 and the like that come into contact with each other in a releasable manner, and conveys a continuous sheet 5 (for example, fan-held paper, etc.).

7BK, 7C, 7M, and 7Y are line heads that are arranged so as to be able to approach and leave the front surface of the sheet 5 between the upper and lower transport rollers 2, and direct black, cyan, magenta, and yellow ink liquid toward the sheet 5, respectively. Dispense. Note that the cap 8 moves upward to shield the ink liquid ejection openings (front surfaces) of the line heads 78K, 7C, 7M, and 7Y during non-recording, thereby preventing dust adhesion and ink thickening. Reference numeral 17 is a motor for driving the conveyance roller 2, and the belt 5 drives the pulley 16 on the same axis 1a of the conveyance roller L and the pulley 1 on the same axis 2a of the conveyance roller 2.
It is connected to 4.

In FIG. 2, support plates 18 and 19 are fixed on a shaft 11 rotatably supported by a chassis (not shown). At the same time, a pulley gear 12 consisting of a pulley portion 12B and a gear portion 12A is rotatably attached.

Further, a pinch roller shaft 4' on which the pinch roller 4 is rotatably supported is fixed to the support plates 18 and 19, and a hinge 20 is attached to one end of the shaft 4', and the pinch roller shaft 4' is suspended between the chassis (not shown). This applies a force of contact between the pinch roller 4 and the conveyance roller 2. Also, the support plate 18.]
9 is provided with notches 18A and 19A, respectively,
The suction roller 9 is guided by the notches 18A and 19A and is rotatably arranged. Here, the suction roller 9 is made of a material (for example, blotting paper or porous material) that has water absorption and water retention properties on its surface, and is connected to the pinch roller 4 by a plate spring 21 fixed to the support plates 18 and 197. Provides contact force of ~
has been done. Further, as shown in FIG. 3 (viewed in the X direction in FIG. 2), the plate spring 21 is shaped like a "<" so as to suppress the suction roller diagonally from above, so that the suction roller 9
It has a structure that can be easily attached and detached. Furthermore, a gear lO is fixed to one end of the suction roller 9, and is engaged with the gear portion 12A of the pulley gear 12.

On the other hand, a belt 13 is stretched over the booby portion 12B of the booley gear 12, and is connected to a pulley 14 on the conveying roller 2 for drive transmission. The support plate 19 is also provided with an operation part 19B, and by pushing it in the direction of the arrow shown in the figure, the contact between the pinch roller 4 and the conveyance roller 2 is released.

Next, the operation of the recording bag of this embodiment will be explained based on FIGS. 1 to 3.

FIG. 1 shows the state of Ki Maki. Here, the motor 17 rotates according to the printing command, and the belt 15 pulls the pulley 1.
4. Rotate 16 in the direction of arrow A. Then, the continuous sheet 5 in the f-side supply side stacker 23'' is conveyed from bottom to top as shown by arrow B, and the upper conveyance roller 2 and pinch roller 4
After passing through fil+, it operates to be discharged onto the discharge side stacker 24. At this time, frictional force is generated between the pinch roller 4 and the sheet 5 due to its surface properties.
Rotational force acts. Since the sheet 5 contacts the sheet 5 with a width, stable conveyance can be achieved. Further, the ink liquid that has not yet been fixed on the sheet 5'' is transferred to the circumferential surface -L of the pinch roller 4. On the other hand, the suction roller 9 is rotated in the direction of arrow C in the figure by being transmitted with the driving force from the motor 17 through the belt 13, pulley gear 12, and gear 10. For this reason, the pinch roller 4 and the suction roller 9
have a certain relative speed (that is, they slide together) at their contact portions, and the ink liquid transferred onto the drawing of the pinch roller 4 is absorbed by the suction roller 9 before making one revolution. As a result, the portion of the pinch roller 4 just before it contacts the sheet can be reliably maintained in a clean state at all times. It should be noted that the operator must press the leaf spring 21 against the elastic force of the leaf spring 21.
By releasing the blotting roller 9 from the shaft 9a of the roller 9, the suction roller 9 can be replaced when necessary.

In addition, the friction coefficient between the sheet 5 and the pinch roller 4, the friction coefficient between the suction roller 9 and the pinch roller 4, the spring force of the spring 20, and the spring force of the plate spring 21 are appropriately selected, and the sheet 5 is transferred to the pinch roller 4. If the rotational force acting on the suction roller 9 is larger than the rotational force acting on the pinch roller 4 from the suction roller 9, no relative speed will occur between the sheet 5 and the pinch roller 4, and the above-mentioned wiping It will definitely be done.

Furthermore, in the embodiment described above, since the pressing force of the suction roller 9 is applied by the plate springs 21 fixed to the support plates 18 and 19), the addition of the suction roller 9 has no effect on the pressing force of the pinch roller 4. Since the pressing force is not applied, this configuration allows the setting of the pressing force described in f to be performed very easily.

As detailed above, according to this embodiment, an inkjet recording apparatus is capable of stably transporting a recording medium, and is capable of constantly recording good images without causing impressions or stains on the recording medium. can be provided.

Note that this embodiment shows a color line recording device having line heads of four colors, or a recording device equipped with so-called serial type heads in which the number of heads is arbitrary and printing is performed by reciprocating the heads in the paper width direction. It is also possible to do this.

Moreover, it goes without saying that the sheet is not limited to a continuous sheet, and a cut sheet can also be used. Furthermore, the method of transmitting the drive to the suction roller can be achieved by connecting only gears, and the direction of rotation of the suction roller can be determined by selecting the rotation ratio so that the relative speed with the pinch roller is generated. , the direction may be reversed from that shown. Further, in this embodiment, the suction roller and the conveyance roller may be driven by the same motor, or may be driven by separate drive sources.

[Effects of the Invention] As explained above, according to the present invention, a recording medium is conveyed by roller pressure contact, and a pinch roller is brought into contact with an exchangeable suction roller whose drive is transmitted at a relative speed to this roller. The dirt on the roller can be wiped off every rotation. In addition, it is possible to provide an inkjet recording device that can stably transport the inkjet recording medium without changing the size of the device, does not leave impressions or stains on the recording medium, and can always record good images.

[Brief explanation of the drawing]

FIG. 1 is a schematic perspective view of a color inkjet recording device;
FIG. 2 is a schematic perspective view of the discharge paper conveyance section, and FIG. 3 is a sectional view of the discharge paper conveyance section. In the figure, 1 and 2 are conveyance rollers, 3 and 4 are pinch rollers, 5 is a sheet, 78, 7C17M, and 7Y are recording heads, 9 is a suction roller, 1O is a gear, and 13 and 15 are belts.

Claims (3)

[Claims] (1) In an inkjet recording device that records an image on a recording medium using ink liquid, a recording head for ejecting the ink liquid, and a recording head located downstream of the recording head with respect to the conveyance direction of the recording medium. between a transport roller/pinch roller pair arranged to pinch and transport the recording medium after an image has been recorded by the recording head, and the pinch roller replaceably provided in contact with the pinch roller; An inkjet recording apparatus comprising: a suction roller for suctioning the ink flow, to which a driving force is transmitted so as to generate a relative velocity. (2) The inkjet recording apparatus according to item (1), wherein the rotational force acting on the pinch roller from the recording medium is greater than the rotational force acting on the pinch roller from the suction roller. (3) The inkjet recording apparatus according to claim 1, wherein the suction roller is pivotally supported on a support member whose one end is fixed to a shaft member on which the pinch roller is rotatably arranged.