JPH04361930A - Sheet feeding device - Google Patents

Abstract

PURPOSE:To enhance presentation of parts, improvement of changability, miniaturization of a device main body, and accuracy and stability of passing sheet by adopting a unit in which a part of a separation mechanism is attached to a sheet feeding cassette, concerning the sheet feeding device. CONSTITUTION:A sheet feeding cassette 34 for storing recording sheets 35, a separation roller 36B having a separation torque limiter 36A for separating the recording sheets 35 on the downstream side in the sheet feeding direction, a carrying and pressurizing roller 41 for carrying the separated recording sheets 35 to the next stage, and a guide board 44 formed from the position close to the separation roller 36B to the position close to the carrying and pressurizing roller 41 are assembled together as a unit, so as to constitute a sheet feeding unit capable of being loaded and unloaded, and is formed on a device main body.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper feeding device, for example, a paper feeding device for a copying machine, a facsimile machine, a printer, etc., which uses a paper feeding cassette containing cut sheets.

0002

[Prior Art] As a conventional paper feeding device, for example, as shown in FIG.
There are those shown in (a) and (b). A paper feeding device 1 shown in FIG. 4(a) feeds recording sheets 4 one by one in a paper feeding cassette 3 as a unit 3A inserted into a main body 2A of an apparatus such as a copying machine 2 by frictional separation. It is something. In the paper feeding device 1, a separation mechanism 5 that separates the recording paper 4 into one sheet is provided within the device main body 2A. The separation mechanism 5 includes a separation roller 5A having a separation torque limiter 5a and a feed roller 5B corresponding to the separation roller 5A, and the pickup roller 6 is rotatably provided around the feed roller 5B. Further, a conveyance roller 7 is provided in the apparatus main body 2A on the downstream side in the paper feeding direction.
The recording paper 4 is conveyed to the next process together with the conveyance pressure roller 8 which is biased toward the conveyance roller 7 side by a spring 8a. A pair of upper and lower guide plates 9A and 9B are provided from the vicinity of the paper feed cassette 3 through the separation mechanism 5 to the downstream side of the conveyance roller 7. Separation roller 5A sometimes needs to be replaced due to deterioration and wear of the rubber on the surface over time.
A also requires refueling.

0003

However, in such a conventional paper feeding device, when replacing the separation roller 5A or the separation torque limiter 5a, first, the paper feeding cassette 3 is removed from the copying machine 2, and Next, the lower guide plate 9B installed inside the copying machine 2 has to be removed before the separation roller 5A and the separation torque limiter 5a are taken out, which requires time and effort to replace and oil the separation roller 5A and separation torque limiter 5a. There is a problem of poor work efficiency.

[0004] Furthermore, the paper feeding device 11 shown in FIG. 4(b) is
Recording paper 14 is fed from two upper and lower paper feeding cassettes. The paper feeding device 11 is connected to the main body 12A of the copying machine 12.
The upper paper feed cassette 13 is removable by inserting and pulling out the paper feed cassette 13, and the recording paper 14 in the paper feed cassette 13 can be called up and fed in the paper feed direction (indicated by arrow A) and transported into the upper conveyance path 16. It has a half-moon-shaped paper feed roller 15. The recording paper 14 fed to the entrance of the upper conveyance path 16 is further passed through the upper conveyance path 16 by an intermediate feed roller 17 and a pressure roller 18 opposing the intermediate feed roller 17 to a registration roller 20 and a registration pressure roller 21. transported between.

Reference numeral 22 denotes a lower conveyance path, and the lower conveyance path 22 is a conveyance path for the recording paper 14 fed from another lower paper feed cassette (not shown) provided below the upper paper feed cassette 13. , merges with the upper conveyance path 16 near the registration rollers 20, and transfers the recording paper 14 to the registration rollers 20 of the registration section 19.
and the resist pressure rollers 21. here,
Paper feed roller 15, upper conveyance path 16, intermediate feed roller 17
, the pressure roller 18, the registration roller 20, the resist pressure roller 21, and the lower conveyance path 22 are attached to the apparatus main body 12A.

However, in such a conventional paper feeding device 11, when releasing the registration pressure when a jam occurs in the registration section, and during maintenance inspections such as replacing the registration rollers 20, the upper feeder is first removed. It is necessary to pull out the paper cassette 13 and remove the intermediate feed roller 17, pressure roller 18, upper conveyance path 16, etc. from the apparatus main body 12A, which poses a problem that maintainability of the registration section 19 is poor.

Furthermore, by attaching the lower transport path 22 for feeding paper from the lower paper feed cassette to the main body 12A of the apparatus, the main body 12A of the apparatus becomes larger, and the operability of replenishing the recording paper into the upper paper feed cassette is also improved. There is a problem that it is bad. In order to solve this problem, it is possible to create a unit in which the registration pressure roller 21 of the registration section 19, the lower conveyance path 22 from the lower paper feed cassette, and the upper paper feed cassette 13 are integrated. , the ease of maintaining the registration section 19 can be improved, the size of the copying machine 12 can be reduced, and the ease of replenishing the recording paper 14 to the upper paper feed cassette 13 can be improved, which can bring many advantages. However, on the other hand, the role of the registration roller 20 is to control the leading edge position of the recording paper 14,
Since the purpose is to correct skew by creating loops, strict precision is required for the paper conveyance path before and after the registration rollers 20 and the registration pressure rollers 21. for example,
If the conveyance path becomes too narrow, it will become a burden to feed the paper,
If it becomes too wide, the detection position of the registration sensor will vary, and the loop amount will become unmanageable. Furthermore, in this apparatus, since the registration roller 20 also serves as a two-directional register from the upper paper feed cassette 13 and the lower paper feed cassette, even more precision is required.

Further, in the paper feed device 11, the recording paper 14 passes through the upper transport path so as to constantly rub against the upper transport path in order to change the transport direction of the recording paper 14 from the upper paper feed cassette 13 in the registration section 19. Further, when the recording paper 14 is fed from the lower paper feed cassette, the recording paper 14 always hits the registration guide plate 22A forming the lower conveyance path 22. For these reasons, the resist guide plate 22A becomes easily charged due to friction. If the registration guide plate 22A is charged, it will cause the registration sensor to malfunction.
In addition, since the recording paper 14 is also sent out while being charged,
When the paper feeding device 11 is used in an electrophotographic device or the like, there is a problem in that it has a significant negative effect.

The present invention has been made against the background of such conventional technology, and includes a separation roller and a separation torque limiter as part of a separation mechanism and a conveyance roller, or a pressure roller of a registration roller, in a paper feed cassette. By assembling some of the parts of the paper feed section, such as the lower conveyance path from the lower paper feed cassette, into a unit, it is possible to improve the maintenance and replaceability of these parts, reduce costs, and reduce the size of the main body of the device. In addition, by using the positioning member of the registration guide plate as a conductor and grounding the contact part to the electrical ground, there is no malfunction of the registration sensor and the accuracy of the registration detection position is improved. It is an object of the present invention to provide a paper feeding device that can improve the distance between conveyance paths and the accuracy and stability of paper feeding.

0010

Means for Solving the Problems In order to achieve the above object, the present invention provides a paper feed cassette for storing recording paper, and a separation torque for separating the recording paper on the downstream side of the paper feeding direction of the recording paper. A separation roller having a limiter, a conveyance pressure roller that conveys the separated recording paper to the next stage, and a guide plate formed from the vicinity of the separation roller to the vicinity of the conveyance pressure roller;
is assembled as a unit and has a paper feeding unit detachably attached to the main body of the apparatus. A paper feeding device that feeds recording paper fed from a paper feeding means through a second conveyance path, and then feeds the paper to registration rollers after merging with the first conveyance path, the paper feeding cassette and the registration rollers are provided. A pressurizing roller and the second conveyance path having a registration guide plate that extends up to the vicinity of the registration roller are assembled as a unit, and a paper feeding unit is detachably attached to the main body of the apparatus, and the registration guide plate is swingable before being attached to the apparatus main body, and after being attached to the apparatus main body, the positioning part of the registration guide plate comes into contact with the contact part provided at the position of the apparatus main body corresponding to the positioning part, and the registration guide According to a third aspect of the present invention, in the sheet feeding device according to claim 2, the positioning portion of the registration guide plate is formed of an electrical conductor, and the contact portion of the device main body is connected to an electric conductor of the device main body. The resist guide plate is grounded to a target ground, and the resist guide plate is positioned and grounded to an electrical ground by contact between the positioning portion and the contact portion.

[0011]

[Operation] According to claim 1 of the present invention, a paper feeding unit in which a paper feeding cassette, a separation roller having a separation torque limiter, a pressure roller, and a guide plate are assembled into a unit is detachably provided in the main body of the apparatus. Therefore, when maintaining or replacing the separation torque limiter and separation roller, the separation torque limiter and separation roller can be removed together by removing the paper feed unit.

[0012] Also, in claim 2, the paper feed unit includes a paper feed cassette, a pressure roller of the registration roller, and a second conveyance path from the paper feed means, and is detachably attached to the main body of the apparatus. Because of this, the pressure rollers of the registration rollers and the second conveyance path can be taken out together when the paper feeding unit is attached and detached. In addition, since the registration guide plate is positioned by bringing the positioning part into contact with the contact part of the apparatus main body, the positioning accuracy of the registration guide plate is high, and the second
The stability of the conveyance path is good.

Further, in claim 3, the positioning portion of the registration guide plate is made of an electrical conductor, and the abutment portion of the apparatus main body is grounded to the electrical ground. The guide plate is precisely positioned and grounded to electrical ground.

[0014]

Embodiments Hereinafter, embodiments of the present invention will be explained based on the drawings. FIG. 1 is a diagram showing an embodiment of a paper feeding device according to claim 1 of the present invention. First, the configuration will be explained. In FIG. 1, reference numeral 31 denotes a paper feeding device, and the paper feeding device 31 constitutes a paper feeding section of the apparatus main body 32A of the copying machine 32. 33 is a unit frame, and the unit frame 33 is detachably attached to the apparatus main body 32A. 34 is a paper feed cassette, and recording paper 35 is stored in the paper feed cassette 34. A separating mechanism 36 for separating the recording paper 35 is provided on the downstream side of the paper feeding cassette 34 in the paper feeding direction. The separation mechanism 36 includes a separation roller 36B having a separation torque limiter 36A on the lower side, and a feed roller 36c having an axis parallel to the separation roller 36B above the separation roller 36B, and includes a separation torque limiter 36A and a separation roller 36B. is attached to the unit frame 33, and the feed roller 36c is attached to the apparatus main body 32A. 37
is a pickup roller, and the pickup roller 37 is rotatably attached around a feed roller 36c on the apparatus main body 32A side, and can pick up the uppermost recording paper 35 and feed it to the separation mechanism 36 side.

40 is a feed roller, 41 is a conveying pressure roller, and the conveying pressure roller 41 is the feed roller 4.
The recording paper 35 is provided parallel to the zero axis and is urged toward the feed roller 40 by a spring 42, so that the fed recording paper 35 can be conveyed to the next stage. The conveyance pressure roller 41 is attached to the unit frame 33, and the feed roller 40 is attached to the apparatus main body 32A. A lower guide plate 44 shown by a broken line that guides the recording paper 35 from the vicinity of the separation roller 36B of the separation mechanism 36 to the downstream side near the feed roller 40 is provided also as the unit frame 33. An upper guide plate 45 is attached to the apparatus main body 32A above the spring 42. In other words, paper feed cassette 3
4. The separation torque limiter 36A, the separation roller 36B, the lower guide plate 44, and the conveyance pressure roller 41 are assembled to the unit frame 33 and form a paper feeding unit 47 shown by a chain line as one unit, and the recording paper 35 It can be pulled out integrally in the direction of arrow B.

Next, the operation will be explained. When replenishing the paper feed, and when maintaining or replacing the separation roller 36B and separation torque limiter 36A, the separation roller 36B and separation torque limiter 36A are connected to the paper feed cassette 34 by pulling out the paper feed unit 47 in the direction of arrow B in the figure. It can be taken out at the same time and the upper part is exposed, making maintenance, replacement, and oiling extremely easy, and the operability during maintenance and replacement can be greatly improved.

Furthermore, by molding the unit frame of the paper feed cassette into a shape that also serves as the lower guide plate 44 and holds the separating roller 36B and the conveying pressure roller 41, the number of parts can be reduced and costs can be reduced. Figure 2
1 is a diagram showing an embodiment of a paper feeding device according to claims 2 and 3 of the present invention. The paper feeding device 51 shown in FIG.
A paper feeding section is configured in the main body 52A of the apparatus.

First, the configuration will be explained. Paper feeding device 5
Reference numeral 1 indicates an upper paper feed cassette 53A which is a paper feed cassette, a half-moon-shaped call roller 56 which is provided above the paper feed side of the upper paper feed cassette 53A and calls out the recording paper 55 stored in the upper paper feed cassette 53A; Recording paper 5 called out at Colo 56
An intermediate feed roller 57 and a pressure roller 58 transport the recording paper 55 in the paper feeding direction (indicated by arrow A), and a registration roller 6 transports the recording paper 55 transported by the intermediate feed roller 57.
It has a substantially horizontal first conveyance path 61 that conveys it to the vicinity of zero. A resist pressure roller 62 is in pressure contact with the resist roller 60. The first conveyance path 61 is formed of a lower guide plate 61A on the lower side, an upper guide plate 61B forming a space between the intermediate feed roller 57 and the registration roller 60, and a feed plate 57A near the intermediate feed roller 57. In the upper paper feed cassette 53A, the recording paper 55 is brought into contact with the calling roller 56 by pushing the bottom plate 63 upward by a spring 64. 65
is a corner nail.

A lower paper feed cassette 53B, which is a paper feed means other than the upper paper feed cassette 53A (not shown), is provided below the upper paper feed cassette 53A. A second substantially perpendicular conveying path 66 is provided for conveying to the rollers 60. The second conveyance path 66 is configured to feed the recording paper 55 to the registration rollers 60 after merging with the first conveyance path 61 near the upstream side of the registration rollers 60 in the sheet feeding direction. The second conveyance path 66 includes a fixed guide plate 66A and a rocking plate made of a plate-shaped conductor that faces the fixed guide plate 66A and forms a portion from the lower part of the second conveyance path 66 to the vicinity of the downstream side of the registration roller 60. It is formed from a movable registration guide plate 66B. The lower end 66b of the registration guide plate 66B is
It is held between grooves 67a formed in the support frame 67, and as shown by arrow B, the distance between the fixed guide plates 66A is made variable.

In the paper feeding device 51, as shown in FIG. 2(b), the paper feeding cassette 70 is connected to the upper paper feeding cassette 53.
A, a pressure roller 58, a lower guide plate 61A and an upper guide plate 61B forming the first conveyance path 61, a resist pressure roller 62 of the registration roller, and a resist guide plate 66B forming the vicinity of the registration roller 60. The two transport paths 66 and the support frame 67 are assembled into a unit and can be detachably attached to the copying machine 52.

The resist guide plate 66B is located at this lower end 66.
As shown in FIG. 3(b), the paper feed unit 70 is held in a groove 67a formed in the lower part of the support frame 67, and is rocked as shown by the arrow B before being installed in the lower conveyance path 22. The guide plate 6 is movable and fixed by the bending spring 72.
It is biased towards the 6A side and stabilized. As shown in FIGS. 3(a) and 3(b), a positioning portion 66c consisting of two L-shaped conductors protruding toward the apparatus main body 32A is provided on the upper part of the registration guide plate 66B. Further, a contact portion 73 is provided at a position corresponding to the positioning portion 66c of the apparatus main body 32A, which abuts against the positioning portion 66c and determines the interval between the second conveyance paths 66. The contact portion 73 is grounded to the electrical ground E of the device main body 32A. After the paper feeding unit 70 is attached to the apparatus main body 32A, the second transport path 6
The positioning part 66c of No. 6 abuts against the contact part 73, and determines the interval of the second conveyance path 66 with high accuracy.
6c and the contact portion 73, the resist guide plate 66
B is arranged to be grounded to electrical earth E.

Next, the operation will be explained. In the present invention,
The upper paper feed cassette 53A, the pressure roller 58, the registration pressure roller 62, and the second transport path 66 are assembled together as a paper feed unit 70, and are detachably attached to the apparatus main body 32A, so that the upper paper feed By attaching and detaching the cassette 53A, the resist pressure roller 62 is used as the paper feeding unit 70.
, the pressure roller 58 can be taken out together. For this reason, when a jam occurs in the resist section, it is possible to remove the jam and
The registration pressure can be released very easily, and since the registration pressure roller 62 and the pressure roller 58 are exposed above the paper feed unit 70, the registration pressure roller 62 can be replaced and the pressure roller 58 can be maintained and replaced. can be done extremely easily.

[0023] Also, the second transport path 66 is connected to the paper feed unit 70.
Since the recording paper 55 is incorporated into the upper paper feed cassette 53A, the apparatus main body 32A can be made smaller and the recording paper 55 can be refilled into the upper paper feed cassette 53A very easily. Furthermore, by attaching the paper feeding unit 70 to the apparatus main body 32A, the registration guide plate 6
The upper positioning part 66c of 6B rotates and the device main body 32
Since the registration guide plate 66B and the fixed guide plate 66A are positioned by contacting the contact portion 73 of Stability can be improved, accurate leading edge position of the recording paper 55 can be obtained, and stable paper feeding performance can be obtained.

Furthermore, the positioning portion 66c is connected to the abutting portion 7.
3, the registration guide plate 66B can conduct electricity to the main body 32A of the apparatus and is grounded to the electrical ground E. Therefore, it is possible to prevent the registration sensor from malfunctioning due to static electricity caused by friction during conveyance of the recording paper 55. Also,
The recording paper 55 is not charged, and stable paper feeding performance can be obtained.

[0025]

[Effect of the invention] As explained above, claim 1 of the present invention
According to the paper feed cassette, by assembling part of the separation roller of the separation mechanism, the separation torque limiter, the lower guide plate, and the conveyance pressure roller into a unit frame, it is possible to lubricate and maintain these parts. , replaceability can be improved, and the number of parts can be reduced, reducing costs. Further, according to claim 2, by forming a unit in which some of the parts of the paper feed section, such as the pressure rollers of the registration rollers and the lower conveyance path from the lower paper feed cassette, are assembled, maintenance and replacement of these parts is facilitated. In addition, by downsizing the main body of the device and improving the operability of refilling recording paper, the registration sensor is It is possible to improve the accuracy of the registration detection position without any malfunction, and also to improve the interval of the conveying path and the accuracy and stability of paper feeding.

[Brief explanation of the drawing]

FIG. 1 is an overall sectional view showing an embodiment of a paper feeding device according to claim 1 of the present invention.

FIG. 2 is a diagram showing an embodiment of a paper feeding device according to claims 2 and 3 of the present invention, in which (a) is a general schematic front view thereof, and (b)
is a schematic front view of the paper feeding unit.

FIG. 3 is a diagram showing the main parts of the paper feeding device shown in FIG.
(a) is a schematic front view showing the vicinity of the registration guide plate, and (b) is a schematic perspective view showing the upper part of the registration guide plate.

FIG. 4 is a diagram showing a conventional paper feeding device, in which (a) is an overall sectional view thereof, and (b) is another overall schematic front view.

[Explanation of symbols]

31, 51 Paper feed devices 32A, 52A Device main body 34 Paper feed cassettes 35, 55 Recording paper 36A Separation torque limiter 36B Separation roller 41 Conveyance pressure roller 44 Lower guide plate 47 Paper feed unit 53A Upper paper feed cassette 53B Lower paper feed Cassette (paper feeding means) 60
Registration roller 61 First conveyance path 62 Registration pressure roller (pressure roller) 66
Second transport path 66B Registration guide plate 66c Positioning section 70 Paper feeding unit 73 Contact section E Electrical ground

Claims (3)

[Claims] 1. A paper feed cassette for storing recording paper, a separation roller having a separation torque limiter for separating the recording paper on the downstream side in the paper feeding direction of the recording paper, and transporting the separated recording paper to the next stage. A paper feeder comprising a conveyance pressure roller and a guide plate formed from the vicinity of the separation roller to the vicinity of the conveyance pressure roller as a unit, and has a paper feed unit detachably attached to the main body of the apparatus. paper equipment. 2. The recording paper from the paper feed cassette is passed through a first conveyance path, the recording paper fed from a paper feeding means other than the paper feed cassette is passed through a second conveyance path, and the first conveyance In the paper feeding device that feeds paper to a registration roller after merging with a path, the second conveyance path includes the paper feeding cassette, a pressure roller of the registration roller, and a registration guide plate that forms a region up to the vicinity of the registration roller. and a paper feed unit which is assembled as a unit and detachably attached to the apparatus main body, the registration guide plate is swingable before being attached to the apparatus main body, and the registration guide plate is swingable after being attached to the apparatus main body. A paper feeding device characterized in that the positioning portion contacts a contact portion provided at a position of the apparatus main body corresponding to the positioning portion to position the registration guide plate. 3. The positioning portion of the registration guide plate is formed of an electrical conductor, and the contact portion of the apparatus main body is grounded to the electrical ground of the apparatus main body, and the contact between the positioning portion and the contact portion 3. The paper feeding device according to claim 2, wherein the registration guide plate is positioned and grounded to an electrical ground.