JPH10157878A - Paper feeder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a paper feeder by which noise due to rubbing between a paper sheet and a flexible plate type member tip edge can be prevented in a paper feeder for an image forming device. SOLUTION: A paper feeding bank conveying path 5, which feeds a paper sheet from a paper feeding bank unit 1 to an image forming unit, and a manual feeding conveying path 15, which feeds the paper sheet from a manual paper feed unit 14 to the image forming device, are arranged so as to overlap each other in front of a registering unit 4, and in the overlapping part, a warp forming space 12 is formed. In the warp forming space 12, a flexible plate type member 18 guiding conveyance of the paper sheets from the respective conveying paths is moved according to the shift of the paper feeding bank conveying path 5 or of the manual feeding conveying path 15, so that the tip edge of the flexible plate type member 18 is prevented from sliding on the paper sheet.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper feeder in an image forming apparatus such as a copying machine, a plain paper facsimile, a laser printer, and the like, and more particularly to a paper feeder capable of preventing paper rubbing noise generated during conveyance.

[0002]

2. Description of the Related Art There is not only one transport path for transporting sheets to an image forming section of an image forming apparatus, but also, for example, a paper feed bank transport path which is transported in a substantially vertical direction from a paper feed bank below the image forming section. And a manual feed path through which sheets are fed in a substantially horizontal direction from a manual feed section disposed on the side of the image forming section.

FIG. 12 is a view showing an example of a conventional sheet feeding device used in an image forming apparatus. A paper supply bank 1 is provided below an image forming unit such as the photosensitive drum 13 and a large number of papers 3 are accommodated in a paper supply tray 2 in a stacked state.

The paper loaded on the paper feed tray 2 of the paper feed bank unit 1 is called up by a pickup roller 6, and the paper feed rollers 7,
The paper is separated into one sheet by the reverse roller 8. The separated sheet 3 is transported by the transport roller pair 9 to the upper registration unit 4. The paper transport path at this time is referred to as a paper feed bank transport path 5 here.

A manual paper feed unit 14 is provided on the side of the image forming unit.
6 and the separation roller 17 reach the resist section 4. The paper transport path at this time is referred to as a manual feed path 15 here.

The leading end of the sheet 3 is abutted against a registration unit 4 that has stopped rotating for a predetermined time in order to align the leading end of the sheet 3 and form an image before the image forming unit. The abutted sheet is then slightly pushed into the image forming section having the photosensitive drum 13 from the resist section 4 so that the sheet can be slightly pushed in and slackened.

The registration unit 4 is composed of an upper metal registration roller 10 and a lower rubber registration roller 11.
After a certain amount of slack is formed in the slack forming space 12 on the sheet 3, the sheet 3 is conveyed to the photosensitive drum 13 while keeping the slack. In this way, the registration unit 4 sets the timing of image formation on the paper 3 and corrects the registration and skew of the paper 3.

FIG. 12 shows a state in which the paper 3 fed from the paper feed tray 2 of the paper feed bank 1 passes through the paper feed bank transport path 5 and hits the registration unit 4 to form a slack. Represents.

The paper 3 separated by the paper feed roller 16 and the separation roller 17 of the manual paper feed unit 14 is transported in a horizontal direction on a manual feed path 15 and is transported to the registration unit 4. The leading end of the sheet 3 passing through the manual feed path 15 is also abutted against the registration unit 4, and a slack is formed.

That is, the slack forming space 12 is required before the resist section 4, but even if there are a plurality of transport paths,
Due to a demand for effective use of space, only one slack forming space is commonly formed in many cases.

In the slack forming space 12, a transport guide is provided by using a flexible plate member 18 called a mylar so that the transport in both the paper feed bank transport path 5 and the manual feed path 15 is performed successfully. Often. The flexible plate-like member 18 transfers the paper 3
Is conveyed, and when the slack is formed in the slack forming space 12, the sheet feeding bank conveying path 5 is closed. Further, since the flexible plate-like member 18 itself is an elastic body, the flexible plate-like member 18 bends during transportation and does not hinder the transportation.

FIG. 13 shows a case where the paper is supplied from the manual paper feed unit 14. In this case, the paper 3 fed from the manual paper feed unit 14 is smooth and flexible even if the registration unit 4 forms a slack. No noise is generated because the surface of the conductive plate member 18 slides.

However, as shown in FIG. 12, the paper 3 transported from the paper feed bank transport path 5 is
Is rubbed by the leading edge of the loudspeaker, generating loud noise. That is, when paper is fed from the paper supply bank unit 1 that is frequently used, the paper conveyance sound is noisy, and the paper feed unit 14 that is used less frequently is used.
When the paper is fed from, the paper conveyance sound is quiet and does not match the actual situation.

On the other hand, in Japanese Patent Application Laid-Open No. Hei 7-228384, a box-shaped paper conveyance guide body is provided between the separation paper feed unit and the registration roller, except for the part where the paper enters and exits, and the other parts are sealed. A configuration has been proposed.

[0015]

However, here, since only a single conveyance path when paper is fed from below is handled,
In a paper feeder having a plurality of transport paths and a common use of a slack forming space for timing adjustment in the resist, it is difficult to form the transport paths in a closed structure.

The present invention has been made in view of the above-mentioned facts, and has as its object to provide a paper feeder capable of preventing generation of noise caused by friction between a sheet and a leading edge of a flexible plate member.

[0017]

It has been found that most of the noise in the paper transport system is generated before the paper passes through the registration unit from the paper supply unit.

Also, comparing the time change of the noise between the time when the sheet is passed and the time when the sheet is not passed, it is found that the sheet once stopped at the registration section is restarted and the front end of the flexible plate member is rubbed with the sheet. It is also known that the difference in noise level is severe.

When the paper is conveyed from the manual paper feed port, no noise is generated even if the paper is conveyed while being sagged and formed, because it slides on the smooth surface of the flexible plate member.

In order to achieve the above object, the present invention provides a plurality of conveying paths overlapping before a resist section;
A sheet feeder having a slack forming space formed in the overlapping portion, and a flexible plate-like member in the slack forming space for guiding conveyance of a sheet from each conveying path; The movable member is moved according to the transport path so that the leading edge of the flexible plate member does not slide on the paper.

The plurality of transport paths include a paper feed bank transport path for feeding paper from a paper feed bank below the image forming unit to the image forming apparatus, and a manual paper feeder disposed on a side of the image forming unit. And a manual feed path for feeding paper from the printer to the image forming apparatus.
And a driving means for moving the flexible plate-like member according to a signal from the detection means, and the flexible plate-like member is turned on and off by a manual sheet feeding unit. Can be moved so that the leading edge of the flexible plate member does not slide on the paper.

The drive means has a solenoid and a spring means for returning the flexible plate member to a predetermined position, and the manual paper feed unit turns on / off the paper by opening and closing the tray.
The detecting means may be configured to include an arm mechanism in which the detecting means interlocks with the opening and closing operation of the tray, and a spring means for returning the flexible plate member to a predetermined position.

Alternatively, a plurality of conveying paths overlapping before the resist portion, a slack forming space formed in the overlapping portion, and a flexible guide in the slack forming space for guiding conveyance of the sheet from each conveying path. In the sheet feeding device having the flexible plate member, the slack forming space may be enlarged, and the sheet from any of the conveyance paths may be arranged so as not to contact the leading edge of the flexible plate member. it can.

[0024]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a configuration of a sheet feeding device as one embodiment of the present invention. The basic configuration is the same as that of the related art, and the common components are denoted by the same reference numerals and description thereof is omitted. In the embodiment of the present invention, the flexible plate-shaped member 1
8 is attached to a mounting member 22 with a double-sided tape or the like, and the mounting member 22 is configured to be rotatable about a support shaft 21. With such a configuration, the conventionally fixed flexible plate member 18 rotates about the fulcrum 21. Further, although the same as the conventional case, the paper feeding bank transport path 5 is generally constituted by a guide plate 23 made of a rigid body such as sheet metal or resin.

The mounting member 22 is connected to a solenoid 24. When the solenoid 24 is sucked, the mounting member 22 is rotated from a position indicated by a dotted line to a position indicated by a solid line. Return to the position. The solenoid 24 and the spring means 2
5 constitutes a driving means for the flexible plate-like member 18.

FIG. 2 is a perspective view showing how the manual tray 19 of the manual paper feed unit 14 is opened and closed. Bypass tray 1
9 is opened as shown in FIG.
The paper 3 is sent to the image forming unit (the photosensitive drum 13 side) through the manual feed path 15. Manual feed unit 1
4 is a detection means 20 for knowing whether manual feed is ON or OFF.
Is provided. The detecting means 20 is a push switch. When the manual tray 19 is closed, the detecting means 20 is pushed and retracted, and the manual sheet feeding is detected as OFF. When the manual feed tray 19 is opened as shown in the figure, the detecting means 20 protrudes, and it is detected that the manual feed is ON.

The operation panel (not shown) of the image forming apparatus has a manual selection display means.
When the user opens the manual feed switch 9, the manual feed open / close switch 20 is no longer pressed, and a manual feed selection is displayed.

FIG. 3 is a perspective view of a structure for rotating the mounting member 22 about the fulcrum 21. In the figure,
The flexible plate-shaped member 18 is attached to the upper part of the mounting member 22 with a double-sided tape or the like. Spindle 2 for rotating mounting member 22
Numeral 1 is fixed by a bearing (not shown) between front and rear side plates of the image forming apparatus.

The solenoid 24 is connected to a pin 26 protruding from the mounting member 22, and the mounting member 22 is rotated about the shaft 21 by the suction of the solenoid 24. The mounting member 22 has a hook 27 for hooking the spring means 25. The spring means 25 is attached to the hook 27 so that the flexible plate 18 is pulled upward when the solenoid 24 is not sucking. I have. In addition, the stopper 28 is abutted against a predetermined place in the apparatus, and is stopped so that the flexible plate-like member 18 does not face too much above a certain position.

FIG. 4 is a flowchart of the operation. First, whether or not the manual feed tray 19 is open is detected by the manual feed open / close switch 20, and when it is OFF (the manual feed tray is open), a current is supplied to the solenoid 24 to cause suction. When the manual feed open / close switch 20 is ON (the manual feed tray is open), the current of the solenoid 24 is turned off. By repeating this flow, the position of the flexible plate member 18 changes in conjunction with the manual feed tray 19. These controls are performed by a control device (not shown).

FIG. 5 shows a state in which manual sheet feeding is OFF. The manual feed tray 19 closes and manual feed is turned off.
If so, the solenoid 24 (see FIG. 1) is not energized and is not sucked, but is pulled by the tension spring 25,
The mounting member 22 and the flexible plate-like member 18 move to the illustrated position (the position indicated by the dotted line in FIG. 1). In this state, the sheet 3 is brought into contact with the resist section 4 to form a slack in the slack forming section 12. In this state, the flexible plate-shaped member 18 is either separated from the paper or is in contact with the back surface. In any case, the leading end of the flexible plate-shaped member 18 and the paper 3 do not slide. No sound is produced.

FIG. 6 shows the position of the mounting member 22 when manual paper feed is used. When the manual tray 19 is opened, the detecting means 20 is not pushed, the manual paper feed is turned on, and the solenoid 24 is sucked. Then, the mounting member 22 and the flexible plate member 18 rotate to the position indicated by the solid line in FIG. This is the same as the position of the conventional flexible plate member 18 shown in FIGS.

At the time of manual sheet feeding, the flexible plate member 18
The reason for setting this position to this position is that, when the slack is formed by using the manual feed in the position of FIG. 5, the load for pushing the flexible plate member 18 during the slack formation becomes larger than the state of FIG. This is because it may be the cause. That is, a space for forming a slack in the sheet 3 fed to the manual feed path 12 is secured. Also in this case, since the leading edge of the flexible plate member 18 does not touch the sheet 3, no rubbing noise is generated.

FIGS. 7 and 8 are diagrams showing the configuration of another embodiment of the present invention. The rotation of the flexible plate member 18 is performed by moving the manual tray 19 and the mounting member 22 to the arm 29.
This is performed by an arm mechanism including the arm and a support shaft 30 of the arm, and the spring means 25. As in the previous embodiment,
The flexible plate member 18 is attached to the upper part of the mounting member 22 with a double-sided tape, and the support shafts 21 and 30 are fixed by bearings (not shown) between the front and rear side plates of the image forming apparatus.

The arm 29 is connected to a pin 26 protruding from the mounting member 22, and the mounting member 22 is rotated about the support shaft 21 as a fulcrum by the vertical movement of the arm 29. The attachment member 22 is provided with a hook 27 for hooking the spring means 25. When the manual feeding tray 19 is closed with the hook means 25, the flexible plate-like member 18 is pulled so as to face upward. ing. The stopper 28 is abutted against a predetermined place in the apparatus, and stops so that the flexible plate-like member 18 does not face too much above a certain position.

When the manual tray 19 is opened, the tip of the arm 29 is pushed up. The arm 29 rotates about the support shaft 30 and turns the tip of the arm 29 connected to the mounting member 22 upward as shown by the arrow. Then, the mounting member 22 rotates about the support shaft 21 to bring the distal end of the flexible plate-like member 18 into a horizontal state as shown by a solid line. Arm 2 when the bypass tray 19 is closed
9 is no longer pushed, so that the mounting member 22 is
Returns to the position indicated by the dotted line.

FIG. 9 is a diagram showing the configuration of still another embodiment of the present invention. In this embodiment, the slack forming space 12 is made wider than before, the position of the flexible plate member 18 is fixed, and the slack forming space 12 is bisected in the transport direction. The attachment member 31 is also shaped so as not to hinder the conveyance of the sheet.

FIG. 10 shows that when the paper is fed from the paper feed tray 2 of the bank unit 1 through the paper feed bank transport path 5, the paper 3 abuts against the registration unit 4, and the paper is slacked upward by the slack forming unit 12. It shows how it is. Even if the sheet 3 is abutted against the resist section 4 and the sheet is slackened at the slack forming section 12, no sound is generated because the sheet slides on the smooth surface of the flexible plate member 18.

FIG. 11 shows that when the paper 3 is fed from the manual feed tray 19, the paper 3 is conveyed from the manual feed path 15, the leading end of the paper 3 abuts against the registration unit 4, and the slack forming unit 12 forms a slack on the lower side. It shows the situation. Thus, even if the sheet 3 is abutted against the resist portion 4 to form a slack, no sound is generated because the sheet slides on the smooth surface of the flexible plate member 18. Therefore, no matter which transport path is used, when the sheet is bent at the registration unit, the sheet slides on the smooth front or back surface of the flexible plate-shaped member, so that the sheet is quiet.

[0040]

According to the present invention as described above,
A plurality of conveying paths overlapping before the registration unit, a slack forming space formed in the overlapping portion, and a flexible plate-shaped member in the slack forming space for guiding conveyance of a sheet from each conveying path; In a paper feeder having a plurality of transport paths, the flexible plate member is moved in accordance with the transport path so that the leading edge of the flexible plate member does not slide on the paper. Regardless of which paper is fed, noise during paper feeding can be prevented, and quiet paper feeding can be achieved.

Also, by widening the slack forming portion in front of the resist and appropriately adjusting the angle at which the flexible plate member is disposed, even if paper is fed from the paper feed tray in the bank portion, it is supplied from the manual feed tray. Even when paper is used, the paper does not slide on the leading edge of the flexible plate member, but slides on the smooth surface of the flexible plate member to generate sliding noise between the paper and the flexible plate member. You can not let it.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a sheet feeding device as one embodiment of the present invention.

FIG. 2 is a perspective view showing how a manual feed tray is opened and closed in a manual feed section.

FIG. 3 is a perspective view of a configuration for rotating a mounting member.

FIG. 4 is a flowchart of an opening and closing operation of a manual feed tray.

FIG. 5 is a diagram illustrating a state of sheet conveyance when manual sheet feeding is OFF.

FIG. 6 is a diagram illustrating a state of sheet conveyance when manual sheet feeding is ON.

FIG. 7 is a diagram showing a configuration of another embodiment of the present invention.

FIG. 8 is a perspective view showing a rotation mechanism of a mounting member in the embodiment of FIG. 7;

FIG. 9 is a diagram showing a configuration of still another embodiment of the present invention.

FIG. 10 is a diagram illustrating a state where a sheet is being conveyed from a sheet supply bank in the embodiment of FIG. 9;

FIG. 11 is a diagram illustrating a state in which a sheet is being conveyed from a manual sheet feeding unit in the embodiment of FIG. 9;

FIG. 12 is a diagram illustrating a configuration of a conventional sheet feeding device, and is a diagram illustrating a state in which sheets are being conveyed from a sheet feeding bank.

FIG. 13 is a diagram illustrating a state in which a sheet is being conveyed from a manual sheet feeding unit by the same sheet feeding device as in FIG. 12;

[Explanation of symbols]

 Reference Signs List 1 paper supply bank 3 paper 4 registration unit 5 (paper supply bank) transport path 12 slack forming space 14 manual paper feed unit 15 (manual feed) transport path 18 flexible plate member 20 detection means 24, 25 drive means 24 solenoid 25 Spring means 29, 30 Arm mechanism

Claims (5)

[Claims] 1. A plurality of transport paths overlapping before a registration unit, a slack forming space formed in the overlapping portion, and a flexible guide in the slack forming space for guiding the sheet from each transport path. A sheet feeding device having a flexible plate-shaped member, wherein the flexible plate-shaped member is moved in accordance with a conveyance path so that a leading edge of the flexible plate-shaped member does not slide on a sheet. Paper feeder. 2. The image forming apparatus according to claim 1, wherein the plurality of transport paths include a paper feed bank transport path for feeding paper from a paper feed bank below the image forming unit to the image forming apparatus, and a manual paper feed disposed on a side of the image forming unit. And a manual feeding path for feeding paper from the image forming apparatus to the image forming apparatus. The manual feeding section is provided with detecting means for detecting ON / OFF of manual sheet feeding, and the flexible plate is provided by a signal from the detecting means. A drive means for moving the flexible member is provided, and the position of the flexible plate member is moved by turning ON / OFF the sheet feeding from the manual sheet feeding unit, and the leading edge of the flexible plate member does not slide on the sheet. The sheet feeding device according to claim 1, wherein 3. The sheet feeding device according to claim 1, wherein said driving means has a solenoid and a spring means for returning the flexible plate member to a predetermined position. 4. The manual sheet feeding section turns ON / OFF the sheet feeding by opening and closing the tray, and the detecting means moves the flexible plate-shaped member to a predetermined position with an arm mechanism interlocked with the opening and closing operation of the tray. 3. The sheet feeding device according to claim 2, further comprising a spring means for returning the sheet to a predetermined position. 5. A plurality of conveying paths overlapping before the registration section, a slack forming space formed in the overlapping portion, and a flexible sheet in the slack forming space for guiding conveyance of a sheet from each conveying path. In the sheet feeding device having the flexible plate-shaped member, the slack forming space is enlarged, and the paper from any of the conveyance paths is arranged so as not to contact the leading edge of the flexible plate-shaped member. Paper feeder.