JPH10338378A - Paper feeding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a paper feeding device excellent in paper feeding accuracy so as to reduce paper feeding failure. SOLUTION: In a paper feeding device 21, roller shafts of nip rollers 25, 26 are arranged in mutually shifted positions in a paper feeding direction. With such constitution, a paper entering between driving rollers 23, 24 and the nip rollers 25, 26 is not held simultaneously by a plurality of nip rollers 25, 26 but held in order by the nip rollers 25, 26 arranged in the mutually shifted positions so as to be able to reduce resistance at the time of feeding the paper. The paper can therefore be fed in a correct conveyance quantity.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper feeder, and more particularly, to a paper feeder provided in a recording device such as a printer for conveying paper.

[0002]

2. Description of the Related Art Conventionally, a recording device such as a printer has been used to print a sheet with a print head or the like.
A paper feeder for feeding the paper is provided. For example, as shown in FIG. 4, this type of sheet feeding device includes driving rollers 1 and 2 driven by a driving source provided in a recording apparatus.
And a plurality of nip rollers 3 and 4 facing the drive rollers 1 and 2 with the paper interposed therebetween.
The drive rollers 1 and 2 are arranged in the printing section 5 for printing the paper 7 in the paper feed direction 8 so as to be opposed to the upstream side and the downstream side, and the upstream side drive roller 1 and the downstream side. The upstream drive roller 1 and the downstream drive roller 2 are respectively provided with an upstream nip roller 3 and a downstream nip roller 4 each including three nip rollers. .

[0003] The paper 7 sent from the paper supply side is fed to the upstream drive roller 1 and the upstream nip roller 3.
By driving the upstream drive roller 1 with the paper 7 being fed, the paper 7 is fed into the printing unit 5 and the paper 7
Is sandwiched between the downstream drive roller 2 and the downstream nip roller 4, and the downstream drive roller 2 is driven to feed the sheet to the paper discharge side.

The roller shafts 3a of the three upstream nip rollers 3 are arranged on the same axis, and the roller shafts 4a of the three downstream nip rollers 4 are also coaxial. Are located in

[0005]

However, when the nip rollers 3 and 4 disposed on the upstream side and the downstream side, respectively, have their roller shafts arranged on the same axis, the driving rollers 1 and 2 are not provided. When the paper 7 enters between the nip rollers 3 and 4, the three nip rollers 3 and 4 sandwich the paper at the same time, so that the resistance when feeding the paper 7 increases. In this case, there is a possibility that a paper feed accuracy is reduced, for example, a transport amount of the paper being transported is reduced, and there is a problem that a paper feed failure occurs.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems, and it is an object of the present invention to provide a paper feeding device which has good paper feeding accuracy and can reduce paper feeding defects. .

[0007]

According to one aspect of the present invention, there is provided a drive roller driven by a drive source, and a nip roller opposed to the drive roller with a sheet interposed therebetween. Wherein the nip roller is provided with a plurality of nip rollers, and a roller shaft of the nip roller is arranged at a position shifted from each other in the paper feeding direction.

According to such a configuration, the paper entering between the drive roller and the nip roller is not simultaneously pinched by the plurality of nip rollers, but is located at a position shifted from each other in the paper feed direction. Nip rollers are successively sandwiched between the nip rollers, so that the resistance when the sheet is fed can be reduced. Therefore, the paper can be fed with an accurate transport amount, the paper feeding accuracy can be improved, and the occurrence of paper feeding failure can be reduced. Also, by shifting the arrangement of the nip rollers, the paper is pressed against the drive roller at a plurality of positions in the paper feeding direction by the nip roller, so that the paper being conveyed is wound around the drive roller. Therefore, the contact area between the paper and the drive roller is increased, and the slip between the paper and the drive roller is reduced,
The driving force for feeding the paper is increased. Therefore, reliable paper feeding can be realized.

The invention described in claim 2 is the first invention.
In the invention described in (1), a plurality of the drive rollers are provided at predetermined intervals in the paper feeding direction, and the nip rollers are provided corresponding to the respective drive rollers. . A plurality of drive rollers and nip rollers provided corresponding to the drive rollers are provided at a predetermined interval, so that the paper can be fed by a plurality of drive rollers, and the transport force of the paper can be increased. Reliable paper feed can be achieved.

[0010] Further, the invention according to claim 3 is based on claim 1.
Alternatively, in the invention described in Item 2, the plurality of nip rollers are arranged including a symmetric arrangement. When a plurality of nip rollers are arranged symmetrically, when the sheet enters the position arranged symmetrically, the sheet can be sent symmetrically in the width direction of the sheet. Therefore, even if the arrangement of the nip rollers is shifted, the sheet can be conveyed without skew and maintaining a good conveyance posture.

The invention described in claim 4 is the first invention.
In the invention according to any one of the above (1) to (3), the central axes of all the nip rollers are located within an angle range of about 40 degrees around the central axis of the drive roller. I have. If the nip roller is located too far from the drive roller, the above-described effects may not be obtained. Therefore, in the positional relationship between the drive roller and the nip roller, the center angle about the center axis of the drive roller is about 40 degrees.
By arranging the drive roller and the nip roller such that the center axes of all the nip rollers are located within the angle range of degrees, the above-described effects can be most effectively exerted.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a side view showing a main part of an embodiment of a recording apparatus provided with a paper feeder according to the present invention. In FIG. 1, a recording device 11 is provided with a paper feed mechanism 14 for supplying paper to a printing unit 13 behind a casing 12 thereof. The paper feed mechanism 14 includes a paper feed tray 15 on which a large number of sheets can be set in a stack, and a paper feed roller 16 disposed at the lower end of the paper feed tray 15. The supplied paper is sequentially supplied to the printing unit 13 by a paper feed roller 16.

The printing section 13 has a print head 17 for printing a sheet and a platen 18 for receiving the sheet. The print head 17 performs printing on the sheet fed on the platen 18. Then, the paper printed by the printing unit 13 is discharged onto the discharge tray 19. In the present embodiment, a paper feeder 21 is provided in the printing unit 13 of the recording device 11. This paper feeder 21
Two upstream drive rollers 23 and two downstream drive rollers 24 arranged with the platen 18 therebetween in the paper feed direction 45.
The upstream drive roller 23 and the downstream drive roller 24 can be driven by a drive source (not shown) provided in the recording apparatus 11. Further, a plurality of upstream rollers driven by the upstream drive roller 23 are provided at positions above the upstream drive roller 23 and opposed to the upstream drive roller 23 with the sheet 46 being fed therebetween. A downstream nip roller 25 is provided, and a downstream drive roller is provided at a position corresponding to the downstream drive roller 24 and above the downstream drive roller 24 and opposed to the sheet 46 to be fed. A plurality of downstream nip rollers 26 are provided, which are driven by 24.

FIG. 2 is a top view of a main part showing the arrangement of the upstream drive roller 23, the upstream nip roller 25, the downstream drive roller 24 and the downstream nip roller 26 in the paper feeder 21. The paper feeder 21 of the present embodiment will be described in further detail with reference to FIG. In FIG.
The upstream nip roller 25 includes three nip rollers 27, 28, and 29 in the same direction as the roller shaft 23a of the upstream drive roller 23. The roller shafts of the three nip rollers 27, 28, and 29 are provided. 27a, 28
a and 29a are positions shifted from each other in the paper feeding direction 45, that is, the roller shaft 28 of the central one of the three nip rollers 27, 28 and 29.
a is the roller shaft 27 of the nip rollers 27, 29 on both sides
a, 29a are disposed so as to be located on the upstream side in the paper feeding direction 45. Also, this arrangement
The center nip roller 28 is the center, and two nip rollers 27 and 29 are symmetrically arranged on both sides. The three nip rollers 27, 28 and 29 are respectively connected to the recording device 11
Are rotatably supported by mounting pieces 33, 34, and 35 which are fixed to the mounting member.

On the other hand, the downstream nip roller 26 moves in the same direction as the axial direction of the roller shaft 24a of the downstream drive roller 24.
Three nip rollers 30, 31, and 32 are provided, and the roller shafts 30a, 31a, and 32a of these three nip rollers 30, 31, and 32 are also shifted from each other in the paper feeding direction 45, similarly to the upstream nip roller 25. Position, that is, the roller shaft 3 of the central nip roller 31 among the three nip rollers 30, 31 and 32
1a is the roller shaft 30 of the nip rollers 30, 32 on both sides.
a, 32a so as to be located on the upstream side in the paper feeding direction 45. Also, this arrangement
Similarly to the upstream nip roller 25, the nip roller 31 has a symmetric configuration in which the center nip roller 31 is the center and two nip rollers 30 and 32 are symmetrically disposed on both sides thereof. The three nip rollers 30, 31 and 32 are rotatably supported by mounting pieces 36, 37 and 38 fixed to the recording apparatus 11, respectively.

In the paper feeder 21 of the present embodiment arranged as described above, the paper 46 fed by the paper feed roller 16 first enters between the upstream drive roller 23 and the upstream nip roller 25. . At this time, first, it enters between the upstream drive roller 23 and the nip roller 28 at the center, and then enters between the upstream drive roller 23 and the nip rollers 27 and 29 on both sides. Therefore, the paper 46 is formed by these three nip rollers 27, 28.
And 29 at the same time.
5, the paper 46
Can reduce the resistance when sending. Therefore, the paper 46 can be fed with an accurate transport amount, the paper feeding accuracy can be improved, and the occurrence of paper feeding failure can be reduced. Further, in the paper feed direction 45, the paper 46 is pressed against the upstream drive roller 23 at two positions: the central nip roller 28 and the nip rollers 27 and 29 on both sides. The state is such that the side drive roller 23 is wound over a predetermined angular range on the circumference. Therefore, the contact area between the sheet 46 and the upstream drive roller 23 is increased, and slippage between the sheet 46 and the upstream drive roller 23 is reduced. Accordingly, the driving force for feeding the paper 46 is increased, and the paper can be reliably fed.

The paper 46 sent by the upstream drive roller 23 is transferred to the print head 1 on the platen 18.
7 and then the downstream drive roller 2
4 and between the downstream nip roller 26. Also in this case, the paper 46 first enters between the downstream drive roller 24 and the central nip roller 31, and then enters between the downstream drive roller 24 and the nip rollers 30 and 32 on both sides. . Therefore, also in this case, similarly to when the sheet 46 enters between the upstream drive roller 23 and the upstream nip roller 25, the resistance when the sheet 46 is fed can be reduced. Therefore, the paper 46 can be fed with an accurate transport amount, the paper feeding accuracy can be improved, and the occurrence of paper feeding failure can be reduced. Further, since the contact area between the sheet 46 and the downstream drive roller 24 can be increased, slippage between the sheet 46 and the downstream drive roller 24 becomes less likely, and the driving force for feeding the sheet 46 is increased. , Reliable paper feed can be realized. Further, if the paper 46 is transported using the two drive rollers, the upstream drive roller 23 and the downstream drive roller 24, the transport force of the paper 46 can be increased, and the paper can be reliably fed. Can be achieved.

The upstream nip roller 25 has a symmetrical arrangement in which nip rollers 27 and 29 on both sides are symmetrically arranged about a central nip roller 28.
In addition, the downstream nip roller 26 is, like the upstream nip roller 25, also centered on the central nip roller 31.
The nip rollers 30 and 32 on both sides are symmetrically arranged symmetrically. Therefore, the sheet 46 fed by the upstream drive roller 23 and the downstream drive roller 24
Can be sent symmetrically in the width direction of the paper 46. Therefore, even if the upstream nip roller 25 and the downstream nip roller 26 are displaced, the paper 46
Can be conveyed while maintaining a good conveyance posture without skew.

FIG. 3 is an explanatory diagram showing the positional relationship between the driving roller and the nip roller. If the nip roller is located too far from the drive roller, the above-described effects may not be obtained. Therefore, as shown in FIG.
All the nip rollers 41 are within a range in which a central angle centered at 2 is about 40 degrees (in FIG. 3, the angle is divided into 20 degrees at the center axis 42 of the drive roller 40 as a boundary). By arranging the drive roller 40 and the nip roller 41 such that the central axis 44 of the drive roller 40 is positioned, the above-described effect can be exhibited most effectively. In this case, within the angular range of the central angle of about 40 degrees, as the plurality of nip rollers 41 move away from each other, the paper being conveyed is wound by the driving roller 41, and the driving force for feeding the paper can be increased. it can. The arrangement of the drive roller 40 and the nip roller 41 shown in FIG. 3 is based on the arrangement of the upstream drive roller 23 and the upstream nip roller 25 and the arrangement of the downstream drive roller 24 and the downstream nip roller 26 in the present embodiment. Is applied to each arrangement.

In this embodiment, three upstream nip rollers 25 and three downstream nip rollers 26 are provided corresponding to the upstream drive roller 23 and the downstream drive roller 24, respectively. Two or more nip rollers may be provided for one drive roller. Further, when the nip rollers are arranged at positions shifted from each other, it is not necessary that all the nip rollers are arranged at different positions.
Also, between all nip rollers adjacent to each other,
There is no need to dispose them at shifted positions. Of all the nip rollers, at least a configuration in which the two nip rollers are arranged at positions shifted from each other between two adjacent nip rollers may be included. Further, in the upstream nip roller 25 and the downstream nip roller 26 of the present embodiment, 3
A symmetrical shape was formed by all the nip rollers,
The symmetric shape may not be formed by all the nip rollers, but may be formed by some nip rollers.

[0021]

As described above, according to the first aspect of the present invention, the paper entering between the driving roller and the nip roller is not caught by a plurality of nip rollers at the same time. Since the paper is successively sandwiched between the respective nip rollers arranged at positions shifted from each other, the resistance when the paper is fed can be reduced.
Therefore, the paper can be fed with an accurate transport amount, the paper feeding accuracy can be improved, and the occurrence of paper feeding failure can be reduced. Also, by shifting the arrangement of the nip rollers, the paper is
Since the paper is pressed against the drive roller at a plurality of positions in the paper feed direction, the paper being conveyed is wound around the drive roller. Therefore, the contact area between the sheet and the drive roller is increased, the slip between the sheet and the drive roller is reduced, and the driving force for feeding the sheet is increased. Therefore, reliable paper feeding can be realized.

According to the second aspect of the present invention, a plurality of drive rollers and a plurality of nip rollers provided corresponding to the drive rollers are provided at a predetermined interval, so that a sheet can be formed by a plurality of drive rollers. It is possible to feed the sheet, to increase the sheet conveying force, and to achieve a reliable sheet feed. Further, according to the third aspect of the present invention, since the plurality of nip rollers are arranged including a symmetrical arrangement, when the sheet enters the symmetrically arranged position, The sheet can be sent symmetrically in the width direction of the sheet. Therefore, even if the arrangement of the nip rollers is shifted, the sheet can be conveyed without skew and maintaining a good conveyance posture.

According to the fourth aspect of the present invention, the center axes of all the nip rollers are located within an angle range of about 40 degrees with respect to the center axis of the drive roller. By arranging the driving roller and the nip roller, the above-described effects can be exhibited most effectively.

[Brief description of the drawings]

FIG. 1 is a main part side view showing an embodiment of a recording apparatus provided with a paper feeding device of the present invention.

FIG. 2 is a main part top view showing an arrangement of each member in the paper feeding device of FIG. 1;

FIG. 3 is an explanatory diagram showing a positional relationship between a driving roller and a nip roller.

FIG. 4 is a main part top view corresponding to FIG. 2 and showing a conventional example.

[Explanation of symbols]

21 Paper Feeding Device 23 Upstream Drive Roller 24 Downstream Drive Roller 25,27,28,29 Upstream Nip Roller 26,30,31,32 Downstream Nip Roller 27a, 28a, 29a Roller Shaft 30a, 31a, 32a of Upstream Nip Roller Roller shaft of downstream nip roller 42 Center axis of drive roller 44 Center axis of nip roller 45 Paper feed direction

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Shin Hattori 15-1 Naeshiro-cho, Mizuho-ku, Nagoya-city Inside Brother Industries, Ltd.

Claims (4)

[Claims] A driving roller driven by a driving source;
A paper feeder comprising: a nip roller opposed to the drive roller with paper interposed therebetween; wherein the nip roller is provided in a plurality, and the roller axes of the nip roller are arranged at positions shifted from each other in the paper feed direction. A paper feeder, characterized in that: 2. The drive roller according to claim 1, wherein a plurality of the drive rollers are provided at predetermined intervals in a paper feeding direction, and the nip rollers are provided corresponding to the respective drive rollers. Paper feeder. 3. The paper feeder according to claim 1, wherein the plurality of nip rollers are arranged including a symmetric arrangement. 4. A central axis of all of the nip rollers is located within an angle range of about 40 degrees around a central axis of the driving roller.
The paper feeder according to any one of the above.