JPH0367828A - Paper feeder - Google Patents

Abstract

PURPOSE:To securely prevent multiple feeding of papers due to accompaniment thereof to each other by providing a handling means capable of abutting against ends of supplied media and parting from the media and a press means capable of pressing the media below the supplied media from the upper side and parting from the under media after pressing. CONSTITUTION:Media M in a magazine 2 is pressed against a paper feed roller 4 by a lift bed plate 5. The upper most media M are exfoliated by the rotational drive of the paper feeding roller 4 and begin to be fed. Soon, the end of the media abuts against a handling means 15 and the end part M1 is deflected upward between the paper supply rollers to form a loop, so that the uppermost supplied media M is surely separated through the space in the loop from the under media M1. When the paper feed proceeds further after such separating operation, the loop is eliminated and the handling means 15 parts therefrom, while the press means 16 is stationarily immediately pressed against the media M1 beneath the supplied media M.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a paper feeding device. That is, the present invention relates to a paper feeding device that is incorporated into a printer and feeds media stored in a magazine, for example.

``Prior art'' When feeding paper using a paper feeding device, it is necessary to separate the media stacked in a magazine, in other words, to reliably separate only the topmost sheet being fed from the second sheet below, etc. ,
It is necessary to prevent the second sheet etc. from being dragged and sent out.

Therefore, as such a paper feeding device, there has conventionally been one that uses a lifting method using negative pressure. That is, as shown in Japanese Patent Application Laid-open No. 60-118544, for example,
There was a paper feeding device that applied negative pressure to media stacked in a magazine using a suction cap, and lifted and fed only the topmost sheet of paper while handling it up and down.

Secondly, there was also a paper feeding device in which paper was fed by a paper feeding roller and corner claws were provided in the magazine. That is, as shown in Japanese Utility Model Application Publication No. 52-103837, for example, a rotationally driven paper feed roller is disposed on the magazine, and corner claws are fixedly provided above both corners of the end of the magazine. There was also a paper feeding device in which the media was brought into pressure contact with a paper feeding roller, and only the topmost sheet of paper was fed while being handled by an upper corner claw.

Problem to be Solved by the Invention 8j By the way, the following problems have been pointed out in such conventional paper feeding devices.

First, the first conventional example, that is, JP-A-60-11854
For the methods shown in Publication No. 4, etc., the following applies. In other words, this paper feeding device requires a suction cap or other mechanism to apply negative pressure, resulting in a complex and large-scale configuration, which poses a problem in terms of cost.In addition, since the media is handled by moving it up and down, it takes a long time to feed the paper. Problems were also pointed out in terms of paper feeding efficiency.

Next, the second conventional example, that is, Utility Model Application No. 52-10383
For the methods shown in Publication No. 7, etc., the following applies. In other words, this paper feeding device poses few problems when built into a copier or the like and feeds plain paper such as weak copy paper, but it is incorporated into various printers and feeds stiff film, paper, etc. as a medium. There were many problems when feeding paper.

In other words, if the media is stiff, it is difficult to handle it using the upper corner claws fixedly attached to the magazine, and the second sheet, etc., may be dragged out by the top paper and may be fed double. It was pointed out that there is. It has also been pointed out that when the media has a photosensitive surface, scratches occur, especially since the corner claws are constantly in contact with the media being fed. Note that such scratches mainly occur on the back side of the media, that is, the back side of the photosensitive surface, but because media such as films are translucent, they are easily noticeable and become a problem.

This point was pointed out in the conventional example.

In view of these circumstances, the present invention has been made in order to solve the problems of the conventional methods described above. By being equipped with a pressing means, etc. that can press the media under the media being loaded, double feeding due to hanging feeding is reliably prevented and scratches do not occur.Moreover, these simple configurations save time. The purpose is to propose a paper feeding device that can be realized without any problems.

"Means for Solving the Problem J" The technical means of the present invention to achieve this object are as follows.

This paper feeding device feeds sheet-like media stacked and stored in a magazine.

It also includes a paper feeding roller, a push-up base plate, a sorting means, and a pressing means.

The paper feed roller is located above the magazine and is driven to rotate.

The push-up base plate is loaded with the media in the magazine, and
It presses the media against the paper feed roller.

The sorting means is provided adjacent to the outside of the magazine, and is capable of coming into contact with the leading edge of the medium fed by the paper feeding roller, and is also capable of separating from the medium.

The pressing means can be pressed from above to the media below the fed media, and can be separated from the media below afterwards.

"Function" Since the paper feeding device according to the present invention includes such means, it functions as follows.

The media in the magazine is pressed against the paper feed roller by the push-up base plate. Then, by rotating the paper feed roller,
The top paper of the media is peeled off and begins to be fed, and eventually its leading edge comes into contact with the handling means, and the leading edge bends upward between the feeding rollers to form a loop. This space ensures that the topmost sheet of media being fed is separated from the media below it.

When the paper feeding progresses further after such a sorting operation, the loop is resolved and the sorting means is separated, and the pressing means is immediately and immovably pressed against the media below the fed media.

First, by using the sorting means and the suppressing means, only one long sheet of media is reliably separated from the second sheet below it, and then the second sheet is pulled and sent out. This prevents double feeding.

Second, as the paper feed progresses after the paper handling operation, the handling means moves away from the fed media and retreats, so that the media will not be scratched by its contact.

Thirdly, these are paper feed roller, handling means,
This can be realized by a simple configuration of the pressing means, and can be realized without requiring any particular time for their operation.

"Example" The present invention will be described in detail below based on the example shown in the drawings.

First, the configuration and the like will be explained in the following order: the laser printer, the outline of the paper feeding device, the sorting means, the suppressing means, etc.

The laser blink is as follows.

FIG. 7 is an explanatory front view of the laser printer. The paper feeding device according to the present invention is incorporated into, for example, such a laser printer, an X-ray photographing device, other image forming devices, and various other media handling devices.

In a laser printer, a magazine 2 is detachably set in a housing 1 that is a sealed body.

Inside the magazine 2, sheet-like media M each having a photosensitive surface are stacked and stored. And Media M is
A sheet feeding device 3, which will be described later, feeds the sheets one by one in the sheet feeding direction, starting from the topmost sheet. In the figure, 4 is a paper feed roller, 5 is a push-up base plate, and 6 is a spring.

The medium M fed from inside the magazine 2 is transported by l pairs of upper and lower transport rollers 7 and reaches the sub-scanning section 8 . The sub-scanning section 8 includes a large-diameter sub-scanning drum 9 and two small-diameter sub-scanning drums that are pressed onto the sub-scanning drum 9 at a predetermined interval.
It consists of sub-scanning rollers 10. Thereupon, the image is written on the medium M while being conveyed while being sandwiched between the sub-scanning drum 9 and the sub-scanning roller 10 which are rotationally driven.

That is, 11 is an optical system unit, and when the leading edge of the medium M is detected by the sub-scanning roller 10, this optical system unit 11 emits a laser beam 12 in accordance with a given image signal. The laser beam 12 is polarized and scanned, and irradiates and exposes the photosensitive surface of the medium M via the ξ beam 13. Therefore, by such a laser beam 12, the media M
On the other hand, main scanning of the image is performed in the width direction, and sub-scanning of the image is performed by conveying the image in the length direction. In this way, the medium M is two-dimensionally scanned and exposed, and after an image is written as a latent image, the medium M is transported to the next development step or the like. Note that 14 in the figure is a guide.

Laser printers work like this.

Next, an overview of the paper feeding device 3 will be described.

1, 2, and 3 are front sectional views showing embodiments of the present invention. Figure 1 shows the state before paper feeding starts, and Figure 2 shows the state before paper feeding starts.
The figure shows the state immediately after the start of paper feeding, and FIG. 3 shows the subsequent paper feeding state. FIG. 4 is a plan view of the same embodiment.

The paper feeding device 3 feeds sheet-like media M stacked and stored in the magazine 2 and provided with a photosensitive surface, and includes a paper feeding roller 4. Push-up base plate 5, etc., and later-described cutting claws 15. It is equipped with a pressing pad 16 and the like.

To explain these in detail, first, the magazine 2 has a box shape with an open top surface, and a push-up base plate 5 is placed in the magazine 2 so as to be movable up and down.
For example, about 100 sheets are stacked on top of each other. The medium M is in the form of a translucent sheet, and a photosensitive surface coated with a photosensitive material such as an emulsion is formed on the upper surface thereof. The medium M is stiffer than plain paper, and is made of, for example, a film such as an IR film or an X-ray film, or paper.

A spring 6 is interposed between the end of the push-up base plate 5 on the paper feeding direction side and the end of the bottom plate of the magazine 2 on the paper feeding direction side. This spring 6 always urges the end of the push-up base plate 5 in the paper feeding direction upwardly, that is, toward the paper feed roller 4 described below, thereby feeding the media M on the push-up base plate 5. It is pressed against the paper roller 4 from below. In addition, as a push-up means for urging and pressing in this way,
It is conceivable to adopt various methods for the spring 6 shown in the drawing.

The paper feed roller 4 is made of rubber, which has a high friction coefficient of about 5 μm or more to increase the paper feeding force, and has a low hardness of about 20 to 30 degrees so as not to damage the photosensitive surface of the media M. . The paper feed roller 4 is attached to the main body of the apparatus and is positioned on the end of the set magazine 2 in the paper feeding direction, so that the media M in the magazine 2 is pressed into contact with the paper feed roller 4 . Note that the front and rear positions of the paper feed roller 4 along the paper feed direction, that is, the left and right positions in FIG.
The leading edge M2 of the media M is sandwiched between the media M and the media M immediately after the paper feeding starts, and the position is set to ensure that a loop is formed.

Reference numeral 17 in FIG. 4 is a motor that is fixed to the main body of the apparatus and serves as a drive source for the paper feed roller 4. A gear 18 is provided on the motor shaft of the motor 17, and a gear 20 is provided on the end of the roller shaft 19 to which the paper feed roller 4 is fixed.
The two are engaged. Thus, the paper feed roller 4 is rotationally driven by the motor 17 via such a transmission mechanism. Note that the roller shaft 19 is attached to the device main body by left and right holding frames 21. Also paper feed roller 4
Although two are provided in the illustrated example, the roller shaft 19
One piece may be provided at the center of the area, or other numbers may be used.

The outline of the paper feeding device 3 is as follows.

Next, we will discuss the means of judgment.

In the illustrated example, the separating claw 1 is used as the separating means of the paper feeding device 3.
5 is used. This handling claw 15 is the magazine 2
It is provided outside and adjacent to the end on the paper feeding direction side, and can come into contact with the leading edge Ml of the media M fed by the paper feed roller 4, and can separate from the media M that is fed. It becomes.

To explain these in detail, the handling claws 15 are placed in an upper handling position (see Figures 1 and 2) in which they can come into contact with the leading edge Ml of the media M immediately after the feed amount 1 2 starts, and the media M that is further fed thereafter. It is possible to move to a lower retracted position (see Fig. 3) away from the lower position. In other words, judgment claw 1
A mounting portion 22 to which the lower portion of the rotor 5 is fixed is connected to a rotary solenoid 24 via a link mechanism 23. The link mechanism 23. Via the attachment portion 22, the cleaning claws 15 are displaced between the upper cleaning position and the lower retracting position. 25 is a holding member that guides and holds the link mechanism 23 and the like, and is fixed to the main body of the apparatus.

Also, the front and back positions of the sorting claw 15 along the paper feeding direction, that is, the first
．． The left and right positions in FIG. 2.3 are set at positions where the leading end M2 of the medium M is sandwiched between the paper feed roller 4 described above immediately after paper feeding starts, and a loop is reliably formed.

FIG. 5 is a perspective view of the cutting claw 15. As shown in the figure, the separating claws 15 are provided in pairs on both sides so as to be able to face both corners of the leading end M+ of the medium M fed in the paper feeding direction indicated by the arrow in the drawing. This judgment claw 15 is a leaf spring.

An elastic material made of resin or the like is used, and its upper part 15 is curved to face the corner of the leading end Ml of the medium M, and its lower part 15□ is formed linearly to feed the medium M. When a pressing force is applied, it bends back and forth.

The means of judgment is as follows.

Next, the pressing means etc. will be described.

As the pressing means of the paper feeding device 3, in the illustrated example, a pressing rose 11 is used.
6 is used. This press bar/knob 16 can be pressed from above to the medium M'' below the fed medium M, and can be separated from the medium M'' below this afterwards.

To explain these in detail, when the aforementioned separating claws 15 take the retracted position, the press bar/groove 16 is placed on the side opposite to the paper feeding direction with respect to the media M' below the media M that is fed in the paper feeding direction. Lower pressure contact position for pressure contact with the rear end (see Figure 3)
Then, after feeding the media M 3 4, the upper evacuation posture moves away from the media M below this (
(see Figure 1.2).

That is, the pressing pad 16 is connected to the magazine 2. Push-up base plate 5
It is located on the bRj portion on the opposite paper feeding direction side, is swingably attached to a link mechanism 27 via a hinge 26, and is connected to a rotary solenoid 28 via this link mechanism 27. Therefore, by the rotation of the rotary solenoid 28 attached to the main body of the device, via the link mechanism 27,
The suppression pad 16 is displaced between a lower pressing position and an upper retracted position. 29 is a holding member that guides and holds the link mechanism 27 and the like, and is fixed to the main body of the apparatus. The press pad 16 freely swings about the hinge 26 when it is pressed against the medium M'', so that it is pressed against the inclination of the medium M'' while accurately fitting it.

30 is a photosensor, and this photosensor 30
is arranged adjacent to the downstream side of the paper feeding direction of the sorting claw 15,
The passage of the leading edge M of the fed media M is detected. Based on the detection signal, the rotary solenoid 24.
28 are turned on, the handling claws 15 assume a lower retracted position, and the press pad 16 assumes a lower pressing position (see FIG. 3). In addition, such a photo sensor 30
Instead, it is also possible to use an ultrasonic sensor or other various sensors.

The suppression means etc. are as follows.

The above is the explanation of the configuration, etc.

The operation etc. will be explained below.

First, before starting paper feeding, this paper feeding device 3 assumes a handling position in which its handling claws 15 protrude above the guide 14, as shown in FIG. 1, and its press pad 16 assumes an upper retracted position. ing. Also, the media M in the magazine 2 is urged by the pusher plate 5, and the paper feed roller 4 is stopped.
It is in pressure contact with the

Next, when the paper feed roller 4 of the paper feed device 3 is rotationally driven,
The topmost paper M is peeled off and begins to be fed, and the corners of its leading edge M come into contact with the handling claws 15 on both sides, which are in the handling position (5 = 16, also see FIG. 4). Then, as the paper feed roller 4 continues to rotate, as shown in FIG. 2, the leading end M2 of the fed media M is sandwiched between the separating claw 15 and the paper feed roller 4, and bends upward to form a loop. do.

Therefore, due to the loop space formed at the leading end M2, the topmost paper M to be fed is separated from the two below.
It is handled and reliably separated from the th media M, etc.

In other words, even if the second media M, etc. were to be sent out and fed by the topmost media M stacked above it, a loop would be formed between them and an air layer would be created. By intervening, the two are separated and reliably separated.

In this paper feeding device 3, as the paper feeding progresses further after such sorting operation, as shown in FIG.
The loop is eliminated and the separating claws 15 are separated and retracted.

At the same time, the press pad 16 is immediately and immovably pressed against the medium M below the medium M to be enshrined.

That is, as the paper feeding roller 4 is further driven to rotate and the feeding of the media M progresses, the leading edge Ml of the media M presses the separating claw 15 and passes through, as shown in FIG.
The loop will be resolved. Then, when the leading end Ml of the medium M is guided by the guide 14 and passes the photo sensor 30,
Based on the detection signal, the rotary solenoid 24.28
are each turned on. As a result, the handling claws 15 take a retracted position lower than the guide 14 from the previous handling position, and the press pad 16 takes a lower pressure contact position from the upper retracted position. In other words, instead of the handling claw 15, the pressing pad 16 is used for the second media M below.
In order to prevent the media M' from being dragged and sent out, it is immediately and immovably pressed against the rear end of the media M' below.

Now, in this paper feeder 3, the following first and second
．． It will be like the third one.

First, in this way, the separating claw 15 and the pressing pad 16 reliably separate only the topmost sheet of media M from the second sheet of media M', etc. below, and feed the paper. This prevents the second media M, etc. from being dragged and sent out and being fed in duplicate. Then, only the fed media M is transported to the sub-scanning section 8 via the transport roller 7 (see FIG. 7). Afterwards, the row cleaning solenoids 24 and 28 are turned off, and the cutting claws 15 return to their original handling positions and the pressing pads 16 return to their original retracted positions.

Second, as the paper feed progresses after the separating operation, the separating claw 15
It moves away from the fed media M and takes a retreating posture. Therefore, avoid scratches on the back surface of the fed media M due to contact with the handling claws 15.
definitely avoided.

Thirdly, these are paper feed rollers 4. Judging claw 1
5. This can be realized by a simple configuration of the pressing pad 16 and the like, and can be realized without requiring any particular time for their operation.

The above is the explanation of the operation, etc.

"Other Examples" Next, other embodiments will be described.

FIG. 6 is a front sectional view of a main part of another embodiment of the present invention.

In the paper feeding device 3 according to another embodiment shown in FIG. 6, the separating claw 31 serves both as a separating means and a pressing means. In other words, the separating claw 31 of this paper feeding device 3 is
It is provided outside the magazine 2 and adjacent to the end on the paper feeding direction side, and is capable of coming into contact with the leading edge Ml of the media M fed by the paper feeding roller 4.
It is possible to press the media M'' below the fed media M away from the media M from above, and to be able to separate from the media M'' below.

To explain these in detail, first of all, this judgment claw 31 is
It is able to swing freely on a horizontal shaft 32 provided at the base end, and is constantly biased counterclockwise in the drawing by an attached torsion coil spring and a stopper (not shown), resulting in the handling indicated by the solid line in the drawing. held in position. In this handling position in which the upper end of the handling claw 31 vertically protrudes above the guide 14, the handling claw 31 is placed in the handling position of the media M to be fed.
It can come into contact with the tip Ml of l9 0 .

Furthermore, the base end of the cleaning claw 31 is connected to a solenoid 33, and when the solenoid 33 is turned on, it is pulled and swung as shown by the arrow in the figure against the biasing force of the torsion coil spring, and as shown by the broken line in the figure. It falls to the magazine 2 side and assumes an inclined pressure contact position.

That is, it retreats from the above-mentioned handling attitude and comes into pressure contact with the leading end of the second medium M below the medium M being fed in the paper feeding direction. Note that the solenoid 33 is then turned off, and the cleaning claws 31 are evacuated from the pressing position by the biasing force of the torsion coil spring and returned to the original handling position.

The sorting claw 31 of the paper feeder 3 in FIG. 6 looks like this,
When the leading edge Ml of the medium M fed after the handling operation passes the photosensor 30, the solenoid 33 is turned on based on the detection signal, and the handling position changes to the pressing position.

Therefore, the paper feeding device 3 shown in FIG.
The second media M, etc. below will not be fed multiple times,
Secondly, no scratches occur on the fed media M, and thirdly, the structure is simple and the operation does not take much time. And this judgment claw 31 is
Since it is used both as a judging means and a suppressing means, its structure is particularly simplified.

In addition, in the paper feeding device 3 of the other embodiment shown in FIG.
The structure 2 functions and operations of other parts are explained in the above-mentioned section 1.
．． 2, 3.4, and the explanation thereof will be omitted since it is the same as that described for the embodiment shown in FIGS.

The above is a description of other embodiments.

"Effects of the Invention" As explained above, the paper feeding device according to the present invention includes a separating means that can come into contact with the leading edge of the media fed by the paper feeding roller, and By being equipped with a pressing means that can be pressed, the following effects can be achieved.

First, double feeding due to hanging feed is reliably prevented. That is, only the topmost sheet 1 2 of the media is fed separately from the second sheet below, etc., and the second sheet etc. are not dragged out and sent out, thereby preventing double feeding. This ensures that the media are fed one by one.

Second, the occurrence of souffle scratches is also avoided. That is,
There are no scratches or scratches on the back side of the media.

Thirdly, these can be realized with a simple configuration and without spending much time. That is, the paper feed roller,
The sorting means, pressing means, etc. are simple in structure and are excellent in terms of cost, and their operations do not require any particular time and are excellent in terms of paper feeding efficiency.

In this way, the problems that existed in this type of conventional example are completely eliminated, and the effects of the present invention are remarkable and great.

[Brief explanation of drawings]

FIG. 1, FIG. 2, and FIG. 3 are front sectional views showing an embodiment of a paper feeding device according to the present invention. FIG. 1 shows the state before the start of paper feeding, FIG. 2 shows the state immediately after the start of paper feeding, and FIG. 3 shows the subsequent paper feeding state. FIG. 4 is a plan view of the same embodiment. FIG. 5 is a perspective view of the cutting claw. FIG. 6 shows another embodiment of the paper feeding device according to the present invention,
It is a front sectional view of the main part. FIG. 7 is an explanatory front view of the laser printer. 2... 3... 4... 5... 15... 16... 31... Magazine paper feeding device Paper feeding roller push-up base plate Judging claw (judging means) Pressing pad (pressing means) Judging claw ( (handling means and pressing means) 3 4 M... Media M to be fed,... Leading edge M... Lower media) 5

Claims (1)

[Scope of Claims] A paper feeding device that feeds sheet-like media stacked and stored in a magazine, comprising: a paper feeding roller located on the magazine and driven to rotate; A push-up base plate is placed on which presses the media against the paper feed roller, and a push-up base plate is provided adjacent to the outside of the magazine and is capable of contacting the leading edge of the media fed by the paper feed roller. The paper is characterized by comprising: a handling means capable of separating from the media; and a pressing means capable of pressing from above the media below the fed media and capable of separating from the media below afterwards. paper feed device.