JP3252050B2 - Paper ejection device of 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 paper discharge device for an ink jet printer.

[0002]

2. Description of the Related Art FIG. 4 shows a conventional example. Reference numeral 1 denotes a paper feeding device. The paper feeder 1 includes a transport roller 2 driven clockwise by a motor (not shown), and a pressing mechanism 5 for pressing a sheet 4 inserted from a paper feed path 3 toward the transport roller 2. A reversing path 7 for reversing the sheet 4 is formed between a part of the outer periphery of the conveying roller 2 and the curved guide plate 6, and a leaf plate for pressing the sheet 4 reversed by the reversing path 7 against the conveying roller 2. 8 is urged in one direction by a spring 9 and is provided rotatably. Also,
A guide plate 10 is provided above the transport roller 2 along the extension surface of the leaf plate 8, and an ink cartridge 11 as a printing unit is provided facing the guide plate 10. The ink cartridge 11 includes an ink tank 12 mounted on a carriage (not shown) that is reciprocally driven along the axial direction of the transport roller 2, and an ink tank 12.
And an inkjet head 13 connected to the printer. Further, a paper discharge receiver 14 is formed on the upper part of the guide plate 10.

A paper discharge guide passage 16 is formed between the guide plate 10 and a holder 15 attached to the guide plate 10, and is driven clockwise by the above-described motor below the paper discharge guide passage 16. Paper discharge roller (rubber roller)
17 is provided rotatably. The holder 15 holds a sheet press 19 urged by a wire 18 to elastically contact the sheet discharge roller 17 and a cleaner wheel 20 contacting the sheet press 19 so as to be rotatable. Further, below the guide plate 10, an eject arm 21 that feeds the trailing edge of the paper 4 conveyed by the paper discharge roller 17 toward the paper discharge receiver 14 is rotatably provided. Further, corner snubbers 22 are formed on both sides of the end portion of the guide plate 10 on the side of the paper discharge receiver 14 to press both side edges of the paper 4 toward the holder 15 and curve the paper 4.

The paper presser 19 is made of synthetic resin as shown in FIGS. 5 and 6, and a boss 24 is formed at the center thereof so as to be rotatably fitted to a pin 23 (see FIG. 4).
Many teeth 25 are formed on the outer periphery. The pin 23 is held by the holder 15 so as to be displaceable in a direction approaching and separating from the paper discharge roller 17 under the urging force of the wire 18.

In the structure shown in FIG. 4, when the transport roller 2 and the discharge roller 17 are driven clockwise by a motor, the paper 4 is fed to the front of the ink jet head 13 by the transport roller 2 and printed by the ink jet head 13. Then, the sheet is conveyed upward by the conveying roller 2 and the sheet discharging roller 17. At this time, since the ink does not immediately dry immediately after printing, the paper 4 is pressed onto the discharge roller 17 by the paper press 19 having the teeth 25 having a small contact area with the paper 4. Specifically, the teeth 2 of the paper presser 19
5 has an area of about 0.1 mm × 0.1 mm, but the tip of the tooth 25 is stained with the ink of the paper 4 and the tooth 25
The ink adhering to the teeth 25 may be transferred to the sheet 4 again.
Is absorbed by.

The paper 4 discharged by the paper discharge roller 17 is reliably discharged to the paper discharge receiver 14 because the trailing edge is pressed by the eject arm 21 which rotates clockwise. At this time, the sheet 4 is bent by the corner snubber 22 to the holder 15 side immediately before being discharged to the sheet discharge receiver 14 and becomes difficult to fall in a direction orthogonal to the bending direction. A margin is given to the time until the receiver 14 falls down to the support plate 14a side on the back side. In other words, the corner snubber 22 allows the print surface of the paper 4 which has been printed first and is supported by the support surface 14a, to have a certain time before the back surface of the paper 4 which has been printed next comes into contact. The ink drying time of the previously printed paper 4 is secured by the time, and the paper 4
This is to prevent undried ink from adhering to the space.

Further, the paper holder 19 made of the synthetic resin described above.
Is expensive, and the metal paper retainer 26 shown in FIG. 7 can be considered for the purpose of omitting the cleaner wheel 20 by reducing the cost of the ink and suppressing the adhesion of the ink by making the tips of the teeth 25 sharper. Have been. The paper presser 26 is etched using stainless steel (SUS304).
It is formed to a thickness of 0.1 mm and has a circular mounting hole 27 in the center.
And a plurality of grooves 28 for press-fitting the mounting hole 27 into a hub (not shown) by elastically deforming the mounting hole 27, and a plurality of teeth 29 are formed on the outer periphery.

Such a paper presser 26 is used in the same manner as the synthetic resin paper presser 19. However, if the angle of the teeth 29 is large, the tip does not become sharp but ink adheres and the angle of the teeth 29 is too small. And the paper 4 has holes, so the experiment was conducted with the angle of the teeth 29 set to 30 ° to 50 °. As a result, the adhesion of the ink was improved, the holes were not formed in the paper 4, and the durability was also improved. It was confirmed that better results were obtained than the conventional product shown in FIG.

[0009]

In order to reliably discharge the paper 4, it is necessary to feed the trailing edge of the paper 4 until it passes through the contact portion between the paper discharge roller 17 and the paper presser 26. The paper discharge roller 17 is additionally rotated. During this time, the paper presser 26 also rotates counterclockwise following the rotational movement of the paper discharge roller 17. As a result, the trailing edge of the sheet 4 is moved to the sheet presser 2 as shown by a virtual line in FIG.
6 is pushed up by the teeth 29. FIG. 8A shows a state in which the paper discharge operation by the paper presser 26 has been further advanced, and the paper 4 is guided by the guide surface of the paper discharge guide passage 16 (in this example, the holder 15
One side). If the paper presser 26 still rotates in the counterclockwise direction in this state, as shown in FIG. 8B, the lower side of the paper 4 in contact with the holder 15 is bent by the teeth 29 of the paper presser 26. It contacts the cutting edge of the tooth 29. As a result, the vicinity of the trailing edge of the sheet 4 may be torn. This is at one point on the outer periphery of the paper presser 26 (tooth 29
The angle β formed between the normal 30 passing through the front end of the tooth 29 and the front surface 29 b of the tooth 29 in the rotation direction is small, and the paper 4 is
This is because the pushing force in the rotating direction of the is large. The teeth 29
Is also limited, the angle α between the normal 30 and the back surface 29a on the rear side in the rotational direction of the teeth 29 is also limited, and in this example, α and β are set to be substantially equal. In particular, as described above, when the corner snubbers 22 that bend both sides of the paper 4 are provided immediately before the paper is discharged, the stiffness near both sides of the paper 4 is increased. The problem of tearing is likely to occur on both sides of the paper 4.

[0010] The paper holder 19 made of synthetic resin shown in FIGS. 5 and 6 also has a symmetrical shape of the teeth 25 with respect to a normal passing through the tips of the teeth 25. Therefore, a similar problem occurs by setting the angle of the teeth 25 to an acute angle.

[0011]

According to the present invention, there is provided a paper discharge guide passage for guiding a paper printed by a printing unit to a paper discharge receiver,
A paper discharge roller driven by a driving unit is rotatably provided near the paper discharge receiving side of the paper discharge guide passage, and is provided after the rotation direction.
The rear surface on the side approximately matches the normal passing through a point on the outer
Angle between the rear side in the rear direction and the front side in the rotation direction
Degree is paper discharge device of an ink jet printer which is provided rotatably by a plurality of paper pressing a number of teeth which is defined to be an acute angle are arranged along the outer periphery to come in contact with the paper discharge roller. The paper presser is made of, for example, stainless steel.
It is formed.

[0012]

In the state where the trailing edge of the sheet is further pushed out to the sheet receiving side by the sheet holding teeth after passing the sheet discharging roller, the gap between the front surface of the sheet holding teeth in the rotation direction advance side and the sheet. Can be widened, so that the trailing edge of the paper can be pushed out toward the outer periphery of the paper presser at the front surface of the teeth without bringing the cutting edge of the teeth into contact with the paper.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIGS. 4, 7, and 8 are denoted by the same reference numerals, and description thereof is omitted. As shown in FIG. 2, a hub 31 made of synthetic resin and a paper holder 32 made of stainless steel (SUS304) formed by etching are provided. The hub 31 has a boss 33 and a flange 34 formed thereon. At the center of the paper presser 32, a mounting hole 35 is provided.
And a plurality of grooves 36 for elastically deforming the mounting holes 35 and press-fitting the mounting holes 35 into the bosses 33 of the hub 31. A large number of teeth 37 are formed on the outer periphery. These teeth 37
Is the angle at which the back surface 37a on the rear side in the rotation direction substantially coincides with the normal line 30 passing through one point (the tip of the tooth 37) of the outer periphery of the paper presser 32, and the front surface 37b on the rotation direction progress side and the normal line 30 become β. , And the angle of the tooth 37 (β in this embodiment)
) Is determined to have a shape that is inclined rearward in the rotation direction so that the angle becomes an acute angle. That is, the paper presser 32 has a ratchet-like shape, a thickness of 0.1 mm, a number of teeth 37 of 60, and an angle β of the teeth 37 of about 50 °.

In such a configuration, the paper presser 32 is pressed into the boss 33 of the hub 31 with the mounting hole 35, and the hub 31 is mounted on the holder 15 via the pin 23 (see FIG. 4). In the state of FIG. 1, in order to reliably discharge the sheet 4, the discharge roller 17 is driven even after the rear end of the sheet 4 has passed the contact portion between the discharge roller 17 and the sheet presser 26. The paper presser 26 also rotates counterclockwise following the rotation of the paper discharge roller 17. As a result, the trailing edge of the sheet 4 enters the valley between the teeth 37 of the sheet holder 32 and the teeth 37, and the trailing edge of the sheet 4 is moved by the front face 37b of the teeth 37 as shown by a virtual line in FIG. Paper receiving tray 14
(See FIG. 4).

In this case, since the angle β of the front surface 37b of the tooth 37 with respect to the normal 30 passing through the tip of the tooth 37 is larger than in the prior art, the front surface 37b of the tooth 37 is more radius than the rotation direction of the paper holder 32. Can be oriented. Thereby, the trailing edge of the sheet 4 can be separated from the front surface 37 b of the teeth 37 in the outer circumferential direction of the sheet presser 32. what if,
As shown in FIG. 3, even if the paper 4 is sent to near the upper outer periphery of the paper presser 32, the angle between the front surface 37 b of the teeth 37 and the paper 4 is wide, and the cutting edge of the teeth 37 is separated from the paper 4. Therefore, the paper 4 can be pushed away from the paper discharge receiver 14 (upward) without tearing the paper 4 at the cutting edge of the teeth 37 of the paper presser 32.

Although the paper presser 32 is press-fitted into the hub 31, the paper presser 32 may be connected at the time of molding by outsert molding when the hub 31 is molded.

[0017]

According to the present invention, the rear surface on the rear side in the rotational direction is the outer periphery.
Approximately coincides with the normal passing through one point, and
The angle between the surface and the front side in the direction of rotation will be acute
Since many teeth defined on cormorants is rotatably provided by touching contact the plurality of paper pressing arranged along the outer periphery to the discharge roller further sheet after the trailing edge of the sheet passes through the sheet discharge rollers Even in the state where the paper is pushed out to the paper receiving side by the presser teeth, the angle formed between the front face of the paper presser teeth on the rotation direction advancing side and the paper can be widened. The trailing edge of the sheet can be pushed out toward the outer periphery of the sheet presser at the front of the teeth without contacting the sheet, and therefore, the vicinity of the trailing edge of the sheet can be prevented from being torn by the blades of the teeth.

[Brief description of the drawings]

FIG. 1 is a front view of a main part showing one embodiment of the present invention.

FIG. 2 is an exploded perspective view showing an attachment structure between the hub and a paper presser.

FIG. 3 is a partial front view showing a sheet discharging operation by the sheet presser.

FIG. 4 is a vertical sectional front view showing an example of a conventional ink jet printer.

FIG. 5 is a front view of the paper presser.

FIG. 6 is a side view of the paper presser with a partial cross section.

FIG. 7 is a front view showing another conventional example of the paper presser.

FIG. 8 is a partial front view showing a sheet discharging operation by the sheet presser.

[Description of Signs] 4 paper 11 printing unit 14 paper discharge receiver 16 paper discharge guide passage 17 paper discharge roller 30 normal 32 paper press 37 tooth 37a back surface 37b front surface

Claims (2)

(57) [Claims] A paper discharge guide path for guiding a sheet printed by a printing unit to a paper discharge receiver is provided, and a paper discharge roller driven by a driving unit is provided near the paper discharge reception side of the paper discharge guide path. It is provided rotatable, and the back on the rear side in the rotation direction
It almost coincides with the passing normal line, and rotates with the back side in the direction of rotation
Set the angle between the front side of the direction progress side and the front side to be acute.
It was a large number of teeth paper discharge device of an ink jet printer, characterized in that a plurality of paper pressing arranged along the outer periphery rotatably provided by touch contact on the paper discharge roller. 2. The paper presser is formed of stainless steel.
The ink jet according to claim 1, wherein
Paper ejection device for printers.