JPH04346365A - Paper feeding device and image forming device - Google Patents

Abstract

PURPOSE:To feed a separated paper sheet securely to a pair of feeding rollers provided near the downstream side of a paper feeding tray even if the paper sheets are jumped up, when the paper sheets are separated one by one by a separating claw for restricting the one corner of the sheets placed on the paper feeding tray. CONSTITUTION:A separating claw 18 for restricting the one corner of paper sheets P placed on a paper feeding tray 12 is provided and, when a paper feeding roller 17 is rotated to feed the paper sheets P, the paper sheets P are separated one by one by the separating claw 18. Also feeding rollers 20 are provided near the other corner opposite to the one corner of the paper sheets P restricted by the separating claw 18. Thus the paper sheets P are fed securely through the feeding rollers 20 since the paper sheets P are kept horizontal on the feeding roller side 20 even if they are jumped up when they are separated from each other by the separating claw 18.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a copying machine or a laser beam printer (LBP), and a paper feeding apparatus provided in the image forming apparatus.

0002

2. Description of the Related Art An example of a paper feeding device in a conventional image forming apparatus is shown in FIGS. 9 and 10.

[0003] In these figures, a paper feed tray 12 on which a plurality of sheets P are stacked is disposed inside the paper feed device, and is urged upward by a compression spring 13 . Further, there is a paper reference surface on one side of the paper feed tray. Paper feed tray 12
The paper feed section 14 disposed near the main body 1 includes a paper feed shaft 16 attached to the main body 1 of the apparatus, and a half-moon-shaped paper feed roller 17 fixed to the paper feed shaft 16. The paper feed shaft 16
is rotated in the direction of the arrow by a drive source (not shown). At the tip of the paper feed tray 12, on the side of the paper feed roller 17, there is a separation claw 1.
8 is disposed, and functions to separate the sheets of paper P sent out by the paper feed roller 17 one by one. Also,
A paper width regulating plate 15 is disposed on the opposite side surface of the separation claw 16 and can be moved in the width direction of the paper (in the direction of the arrow in FIG. 10) to accommodate papers of various paper widths.

[0004] On the downstream side of the paper feed roller 17 (the side in the paper traveling direction with respect to the paper transport direction is the downstream side, and the opposite side is the upstream side), there is a guide plate 19 and a paper feed roller. 17
Pairs of conveyance rollers 20 are disposed downstream of and on the separation claw 18 side, and each of the pair of conveyance rollers 20 includes a drive roller 20a and a driven roller 2 that is in pressure contact with the driving roller 20a and rotates as a result of the driving roller 20a.
It consists of 0b.

The above-mentioned paper feed shaft 16 and paper feed roller 17 are
The paper P is rotated and sent along the paper reference plane F, and the separation claw 1
The paper P is separated one by one by 8, sent out from the paper feed tray 12, and transported to a pair of transport rollers 20.

[0006]

[Problem to be solved by the invention] However, FIG.
As shown in FIG. 12, in the case where a pair of transport rollers 20 are provided near the separation claw 18, the separation claw 18 side of the paper P sent out by the rotation of the paper feed roller 17 is regulated by the separation claw 18, as shown in FIG. Then, as shown in FIG. 13, the edge of the paper P on the separation claw 18 side temporarily jumps up and rides on the pair of transport rollers 20, and the paper P may not be transported correctly. was there.

Therefore, as in the conventional example shown in FIG.
The end of the paper P on the separation claw 18 side bounces up and descends to the vicinity of the guide plate 19, and the paper P moves a sufficient distance between the paper feed tray 12 and the pair of transport rollers 2 so that the paper P is in a stable running state.
It was necessary to take it between 0.

[0008] This has been an obstacle when attempting to miniaturize the device.

Therefore, the present invention reduces the distance between the separating claw 18 and the pair of conveying rollers 20, thereby reducing the size of the device and reducing the size of the paper P.
The purpose is to shorten the transportation time.

0010

[Means for Solving the Problems] The present invention provides a paper feed tray for stacking a plurality of recording materials, a feeding means for feeding out the recording materials loaded on the paper feed tray, and a feed tray for feeding the recording materials loaded on the paper feed tray. Regulate the leading corner of one side of the loaded recording material,
A paper feeding device including one separation claw that separates the recording materials sent out by the feeding means one by one, and a conveyance means that transports the recording materials separated by the separation claw, wherein the recording material The conveying means is disposed near the leading end portion of the recording material so that the recording material does not jump up due to the separation claw during separation.

[0011]

[Function] According to the above configuration, when the paper feeding means feeds out the recording material loaded on the paper feed tray and separates it with the separation claw, the corner of the recording material on the separation claw side jumps up, but the paper is transported Since the means is provided in the vicinity of the leading end part where jumping up does not occur, the recording material surely reaches the conveying means and is conveyed.

0012

Embodiment A first embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

In these figures, an image forming apparatus 1 includes a photosensitive drum 3, a laser scanner 4, etc., which rotate in the direction of the arrow, in the main body 2 of the image forming apparatus 1. Laser light 5 is output from the laser scanner 4 in response to an image signal from a controller (not shown), and by irradiating the photosensitive drum 3 with this laser light via the mirror 6, an electrostatic latent image is formed on the photosensitive drum 3. is formed. The electrostatic latent image is transferred to developer 7.
A toner image is formed by developing the toner image, and this toner image is transferred by the transfer charger 8 to the paper P that is being conveyed as will be described later.

On the downstream side of the photosensitive drum 3, there are a paper conveyance guide 9 for correctly conveying the paper, a pair of fixing rollers 10 for fixing the toner image, a pair of discharge rollers 11 for discharging the fixed paper P out of the machine, etc. are placed respectively.

A plurality of sheets P are arranged upstream of the photosensitive drum 3.
A paper feed tray 12 loaded with paper is provided, and is urged upward by a compression spring 13. A paper reference plane is located at a position that regulates one side edge of the paper P on the paper feed tray 12 . Further, on the opposite side of the paper reference surface, at the side edge of the paper P, there is a width regulating plate 15, which regulates the side edge of the paper P.

A width regulating plate 15 is installed at the most upstream end of the paper feed tray 12.
A separation claw 18 is arranged at a position regulating the corner of the paper P on the side, and has the function of separating a plurality of stacked papers P one by one.

[0017] Here, the paper feed roller 17, the separation claw 1
8. The width regulating plate 15 is connected by a member 23 that regulates the position of the paper feed roller 17 in the direction perpendicular to the paper conveyance direction, and in order to accommodate various sheets of different widths, the width regulation plate 15 is It is possible to move as a unit in the vertical direction.

Further, a pair of transport rollers 20 is arranged near the downstream side of the paper feed tray 12 and on the paper reference plane F.

By rotating the paper feed shaft 16, the paper feed roller 17 rotates, and the paper feed device starts feeding paper as shown in FIG. Due to the rotation of the paper feed roller 17, the tip corner of the fed paper P on the separating claw 18 side is bulged under the control of the separating claw 18 as shown in FIG. 4, and then as shown in FIG. Although the paper P jumps up temporarily, the leading edge of the paper P on the paper reference plane F side is only pushed horizontally to the upstream side, so it can be transported even by the transport roller pair 20 located very close to the upstream side of the paper feed tray 12. Become.

FIGS. 6 and 7 show a second embodiment of the present invention.

In the second embodiment as well, the conveyance roller 21 is arranged on the paper reference plane F side opposite to the separation claw 18. Further, here, in addition to the paper feed roller 17, an auxiliary roller 25 is fixedly attached to the paper feed shaft 16 in order to accommodate paper of various paper widths.

Further, the conveyance roller section 21 disposed downstream of the paper feed tray 12 includes a drive roller 21a having a large diameter,
It is composed of two driven rollers 21b, 21c with a small diameter and a guide plate 22, and the two driven rollers 21b
, 21c are driving rollers 21 as shown in FIG.
-a is attached at a slight angle θ. The paper P fed by the paper feed roller 17 is
After being sent out to the conveyance roller section 21, the driven roller 21
b, 21c, while the end thereof is pressed against the paper reference surface F, it is moved along the guide plate 22 by the drive roller 21a in a more stable state than that shown in the first embodiment.
conveyed in a shape.

Here, the conveyance roller section 21 is installed on the separation claw 18 side, and the paper P is conveyed while being pressed against the paper reference surface F by driven rollers 21b and 21c arranged diagonally with respect to the drive roller 21a. Considering this, it is easy to think that if the distance between the conveyance roller section 21 and the paper reference plane F is long and the rigidity of the paper P is small, the paper P will bend.

Therefore, it can be seen from this embodiment that it is advantageous to install the conveyance roller pair 20 on the paper reference plane F side opposite to the separation claw 18.

[0025] Here, an example has been shown in which the paper P is conveyed in a U-shape by the conveyance roller section 21, but the same effect will be obtained even if the paper P is conveyed horizontally as in the first embodiment. Become.

Note that the present invention can also be applied to paper feeding from a paper feeding tray such as a cassette or deck.

Furthermore, the present invention can be applied to various image forming apparatuses such as copying machines, dot printers, and inkjet printers in addition to LBPs.

[0028]

As explained above, according to the present invention, when paper is sent out from the paper feed tray, the conveyance roller is installed on the opposite side of the separation claw side where the paper does not jump up.
It is now possible to make the distance between the paper feed tray and the transport rollers in the transport direction much smaller than in the past, making it possible to save space on the downstream side of the paper feed tray and shorten the transport time.

[Brief explanation of drawings]

FIG. 1 is a vertical cross-sectional view of an image forming apparatus implementing a first embodiment of the present invention;

FIG. 2 is a perspective view of the paper feed section in FIG. 1;

FIG. 3 is a perspective view showing the state of the paper feeding unit in FIG. 2 before paper feeding;

FIG. 4 is a perspective view showing a state in the middle of paper separation in the paper feed section of FIG. 2;

FIG. 5 is a perspective view showing a state in the middle of conveyance in the paper feeding section of FIG. 2;

FIG. 6 is a vertical cross-sectional view of an image forming apparatus implementing a second embodiment;

FIG. 7 is a perspective view of the upstream side of the drum in FIG. 6;

[Figure 8]
A plan view showing the arrangement relationship between the driving roller and the driven roller in the second embodiment,

FIG. 9 is a sectional view showing an example of a conventional paper feeding device;

[Figure 10
] A perspective view of FIG. 9,

FIG. 11 is a perspective view showing a state before paper feeding in another example of a conventional paper feeding device;

12 is a perspective view showing a state in the middle of paper separation in the paper feeding device of FIG. 11,

FIG. 13 is a perspective view showing a state in the middle of conveyance in the paper feeding device of FIG. 11;

[Explanation of symbols]

P Paper (recording material) 1 Image forming device 2　Device body 12 Paper feed tray 14 Paper feed section 18 Separation claw 20 Conveyance roller (conveyance means)

Claims (3)

[Claims] 1. A paper feed tray for stacking a plurality of recording materials, a feeding means for feeding out the recording materials loaded on the paper feed tray, and a feeder for feeding the recording materials loaded on the feed tray. one separation claw that regulates a tip corner on one side and separates recording materials fed out by the feeding means one by one;
A paper feeding device comprising: a conveying means for conveying the recording material separated by the separation claw, in the vicinity of the leading end portion where the recording material does not jump up due to the separation claw when the recording material is separated; A paper feeding device characterized in that the above-mentioned conveying means is arranged. 2. The conveyance means according to claim 1, wherein the conveyance means is arranged on the side of the leading end corner opposite to the leading end corner where the claw member is disposed, with respect to the widthwise center of the recording material. Paper feed device. 3. A paper feed tray for stacking a plurality of recording materials, a feeding means for feeding out the recording materials loaded on the paper feed tray, and a feeder for feeding the recording materials loaded on the paper feed tray. one separation claw that regulates a tip corner on one side and separates recording materials fed out by the feeding means one by one;
In the image forming apparatus, the image forming apparatus includes a conveyance means for conveying the recording material separated by the separation claw, and an image forming means for recording an image on the recording material conveyed by the conveyance means, the separation of the recording material The paper feeding device is characterized in that the conveying means is disposed near a leading end portion where the recording material does not bounce up due to the separating claw.