JPH10157227A - Ink-jet printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a printing medium from being stained with ink and smoothly surely discharge and transfer the medium even when the printing medium has poor ink-absorbing efficiency and is hard to dry. SOLUTION: (1) An auxiliary holding means 21 is adapted to selectively bring a contact part 22 in touch and out of touch with a printing medium M on a contact feed face 12 of a main feed means 11. (2) The contact feed face of the main feed means is formed of a belt 12 of a belt conveyor 11, and moreover a negative pressure suction means 51 is provided to such the printing medium M with a negative pressure through a plurality of suction holes 15 formed to penetrate in a thicknesswise direction of the belt 12 of the belt conveyor 11. (3) The contact feed face of the main feed means is formed of the belt 12 of the belt conveyor 11, and a charging means is provided for charging the belt 12 thereby attracting the printing medium with the electric charges.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a main feed means having a contact feed surface capable of contacting a non-print surface of a print medium, and a contact portion capable of contacting a print surface on which characters, images, etc. are printed by a print head. And an auxiliary feeder having the same.

[0002]

2. Description of the Related Art FIG. 3 shows a conventional structure of an ink jet printer. In the figure, 2 is a print head and 5 is a platen. The print head 2 has a predetermined gap (for example, 0.5 to 1.0 m) with respect to the conveyed print medium M.
m), and a plurality of ink ejection ports are usually arranged on the front surface facing the print medium M.

The print head 2 reciprocates by a carriage (not shown) in a direction perpendicular to the plane of the drawing and ejects ink droplets from the ink discharge ports to the print surface of the conveyed print medium M to print characters and characters. An image or the like can be printed.

After printing, the print medium M is transferred to the discharge / convey device 10
P discharges and conveys in a predetermined direction. The discharge conveyance device 10P includes a main feeding unit (conveyance roller 11R) having a contact feeding surface capable of contacting a non-printing surface of the printing medium M and a printing surface on which characters and images are printed by the print head 2. And an auxiliary feeding means (21) having a contact portion.

[0005] The auxiliary feeding means (21) mainly comprises a printing medium M
Serves to prevent the main feeding means (conveying roller 11R) from rising from the contact feeding surface, and is particularly effective when the printing medium M is relatively weak, such as plain paper. Function. This auxiliary feeding means is generally formed of a spur-shaped member 21 having a contact area as small as possible so that ink does not easily adhere. Note that 31
Reference numeral denotes an ink absorbing roller, which is formed so as to be able to absorb ink attached to the spur-shaped member 21.

[0006]

In the above-mentioned ink jet printer, some print media M, such as a thin plastic plate (for example, an OHP film), which is stiffer than plain paper but hardly dries the ink. is there. An auxiliary feeding means (spur-shaped member 2)
When the contact portion of 1) comes into contact, the contact portion is
Ink droplets on the printing surface of the above-mentioned printing device are caused to fly around due to splashing or the like, and the printing quality is degraded.

SUMMARY OF THE INVENTION An object of the present invention is to provide an ink jet printer which can smoothly and surely discharge and convey ink while preventing ink contamination even if the printing medium is such as an OHP film or the like where the ink is difficult to dry. It is in.

[0008]

According to a first aspect of the present invention, there is provided a main feeding means having a contact feeding surface capable of contacting a non-printing surface of a printing medium, and a printing surface on which characters and images are printed by a printing head. And an auxiliary feeding means having a possible contact portion, wherein the auxiliary feeding means is formed so as to be capable of selectively contacting and separating the contact portion with a printing medium on a contact feeding surface of the main feeding means. Be characterized.

According to this invention, when the print medium is relatively stiff and has a good ink absorbency, such as plain paper, the contact portion of the auxiliary feed means is connected to the print medium on the contact feed surface of the main feed means. Contact. Thus, the print medium can be smoothly and reliably discharged and conveyed while reliably preventing the print medium from rising. At this time, since the printing medium has good ink absorbency, even if the contact portion of the auxiliary feeding means comes into contact with the ink droplet on the printing medium, the contact portion does not splash the ink droplet to the surroundings by splashing or the like. Absent.

When the printing medium has poor ink absorbency and hardly dries the ink such as an OHP film, the contact portion of the auxiliary feeding means is separated from the printing medium on the contact feeding surface of the main feeding means. Let it. This can prevent ink contamination due to ink splashing or the like. At this time, the OHP film or the like can be smoothly and reliably discharged and conveyed without being lifted to such an extent that the conveyance is hindered even if the auxiliary feeding means is distant and strong.

Further, according to the present invention, the contact feed surface of the main feed means is formed of a belt of a belt conveyor, and a plurality of suction holes formed through the belt in the thickness direction of the belt conveyor. And a negative pressure suction means capable of suctioning the printing medium through a negative pressure.

In this invention, the printing medium is sucked under negative pressure onto the belt conveyor as the main feeding means. Therefore, even if the contact portion of the auxiliary feeding means is separated from the printing medium on the belt of the belt conveyor, the printing medium is removed. Floating can be more reliably prevented. Therefore, if the print medium is OHP
Even if the ink is difficult to dry such as a film for use, the ink can be more smoothly and reliably discharged and conveyed while preventing ink contamination.

[0013] Further, according to a third aspect of the present invention, the contact feeding surface of the main feeding means is formed by a belt of a belt conveyor, and the charging means charges the belt of the belt conveyor to attract the print medium. Is provided.

In this invention, since the print medium is adsorbed on the belt conveyor, even if the print medium is hard to dry such as an OHP film or the like, as in the case of the second aspect of the invention, In addition, the ink can be more smoothly and reliably discharged and conveyed while preventing ink contamination.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. This inkjet printer is shown in FIG.
As shown in FIG. 2 and FIG. 2, the basic configuration is the same as that of the conventional example (FIG. 3), but a contact / separation mechanism 41 for the auxiliary feeding means (21) is provided, and the contact portion ( 22)
Is selectively movable toward and away from the print medium M on the contact feed surface (12) of the main feed means (11).

The same components as those in the conventional example (FIG. 3) are denoted by the same reference numerals, and description thereof will be simplified or omitted.

The main feed means is formed of a belt conveyor 11 having a belt 12 as a contact feed surface capable of contacting the non-print surface of the print medium M. The belt 12 includes a pair of rotating members 13 and 14 that are spaced apart from each other in the print medium feeding direction.
Has been passed over. The rotating body 13 is driven to rotate clockwise in the figure by a drive motor (not shown). The auxiliary feeding means is formed of a spur-shaped member 21 having a gear shape and having a plurality of contact portions 22.

The contact / separation mechanism 41 includes a support member 42, a spring 44, and an actuator 45, and is formed so that the contact portion 22 of the spur-shaped member 21 can be selectively brought into contact with and separated from the printing medium M on the belt 12 of the belt conveyor 11. Have been.

More specifically, the support member 42 has a base end rotatably supported by a printer main body (not shown) by a support shaft 43 and a spur-shaped member 21 at a front end.
And an ink absorbing member (ink absorbing roller 31) are rotatably mounted. The spring 44 includes a support member 42
Are urged in the counterclockwise direction in FIG. The actuator 45 is connected to the support member 42, and is provided to be able to turn the support member 42 upward against the urging force of the spring 44.

Therefore, when the support member 42 is rotated upward by driving the actuator 45, the spur-shaped member 21 is rotated.
Of the print medium M is separated from the print surface of the print medium M. When the driving of the actuator 45 is stopped, the contact portion 22 of the spur-shaped member 21 comes into contact with the printing surface of the printing medium M according to the urging force of the spring 44.

The belt conveyor 11 has a printing medium M
The negative pressure suction means 51 capable of suctioning the print medium M under a negative pressure is provided in order to prevent the print medium M from rising further more reliably and to hold the print medium M on the belt 12.

The negative pressure suction means 51 is connected to the belt conveyor 11.
A plurality of suction holes 15 formed in the thickness direction of the belt 12, a suction fan 55, and an air suction member connected to the suction fan 55 and the suction pipe 54 and capable of sucking air through each suction hole 15. 52, and each suction hole 15
The printing medium M is formed so as to be able to suck the printing medium M to the belt 12 under a negative pressure.

Next, the operation and operation of this embodiment will be described. If the print medium M is relatively stiff and has good ink absorbency, such as plain paper, the contact / separation mechanism 41
To bring the contact portion 22 of the spur-shaped member 21 into contact with the print medium M supplied on the belt 12 of the belt conveyor 11.

Thus, the printing medium M can be smoothly and reliably discharged and conveyed by the belt conveyor 11 while reliably preventing the printing medium M from floating. At this time, since the print medium M has good ink absorbency, even if the contact portion 22 of the spur-shaped member 21 comes into contact with the ink droplet on the print medium M, the contact portion 22 jumps the ink droplet to the surroundings by splashing or the like. There is no such thing.

If the print medium M is a strong one such as an OHP film but has poor ink absorbency and the ink is hard to dry, the negative pressure suction means 51 is driven to allow air to flow from each suction hole 15. Suction. As a result, the printing medium M sent to the belt conveyor 11 is suctioned to the belt 12 by negative pressure. At the same time, the contact / separation mechanism 41 is driven to separate the contact portion 22 of the spur-shaped member 21 from the print medium M on the belt 12. This can prevent ink contamination due to ink splashing or the like. At this time, since the OHP film or the like has a strong stiffness and is sucked under a negative pressure, even if the spur-shaped member 21 is separated, it does not float up and can be smoothly and reliably discharged and conveyed.

According to this embodiment, since the contact portion 22 of the spur-shaped member 21 is provided with the contact / separation means 41 capable of selectively contacting / separating the print medium M on the belt 12, the print medium M can be used. Even if the ink dries slowly, such as an OHP film, it can be discharged and conveyed without causing ink contamination.

Further, since the negative pressure suction means 41 is provided on the belt conveyor 11, the printing medium M can be more reliably held on the belt conveyor 12 and discharged and conveyed.

In the above embodiment, the negative pressure suction means 51 is used.
And the printing medium M is transferred to the belt 12 of the belt conveyor 11.
However, as shown in FIG. 2, a charging means (61) is provided to charge the print medium M with a positive charge, and to utilize the charge adsorption force generated between the print medium M and the grounded belt 12. The print medium M may be adsorbed on the belt 12.

According to this configuration, even if the printing medium is one in which the ink does not dry easily, such as an OHP film,
It is possible to discharge and convey more smoothly and reliably while preventing ink contamination.

[0030]

According to the first aspect of the present invention, the auxiliary feeding means is formed so that the contact portion can be selectively contacted with and separated from the printing medium on the contact feeding surface of the main feeding means. However, even if the ink is hard to dry such as an OHP film, the ink can be smoothly and reliably discharged and conveyed while preventing ink contamination.

According to the second aspect of the present invention, the contact feed surface of the main feed means is formed by a belt of a belt conveyor, and a plurality of suction holes formed through the belt in the thickness direction of the belt conveyor. Since the negative pressure suction means for suctioning the print medium through the print medium is provided, the same effect as that of the first aspect of the invention can be obtained, and the discharge and conveyance of the print medium can be more reliably suppressed while the print medium is lifted.

Further, according to the third aspect of the present invention, the contact feeding surface of the main feeding means is formed by a belt of a belt conveyor, and the charging means for charging the belt of the belt conveyor to attract the printing medium is provided. Since it is provided, the same effect as in the case of the first aspect of the invention can be obtained, and the discharge and conveyance of the print medium can be more reliably suppressed while the floating of the print medium is suppressed.

[Brief description of the drawings]

FIG. 1 is a diagram for describing an embodiment of the present invention.

FIG. 2 is a view for explaining a charging unit.

FIG. 3 is a diagram for explaining a conventional configuration of an ink jet printer.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Belt conveyor (main feed means) 12 Belt (contact feed surface) 15 Suction hole 21 Spur-shaped member (auxiliary feed means) 22 Contact part 41 Contact / separation mechanism 51 Negative pressure suction means 61 Charging means

Claims (3)

[Claims] A main feeding means having a contact feeding surface capable of contacting a non-printing surface of a printing medium; an auxiliary feeding means having a contact portion capable of contacting a printing surface on which characters, images, etc. are printed by a print head; The inkjet printer according to claim 1, wherein the auxiliary feeding means is formed so that the contact portion can be selectively brought into contact with or separated from a printing medium on a contact feeding surface of the main feeding means. 2. The printing device according to claim 1, wherein the contact feeding surface of the main feeding means is formed of a belt of a belt conveyor, and the printing medium is passed through a plurality of suction holes formed in a thickness direction of the belt of the belt conveyor. 2. The ink jet printer according to claim 1, further comprising negative pressure suction means capable of pressure suction. 3. The method according to claim 1, wherein the contact feeding surface of the main feeding means is formed by a belt of a belt conveyor, and a charging means capable of charging the belt of the belt conveyor to adsorb the print medium is provided. The ink jet printer according to claim 1, wherein: