JPH11268842A - Paper feeding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a paper feeding device capable of reducing collision sound to be generated when a recorded paper retaining member of a recording paper retaining mechanism is returned to the waiting position. SOLUTION: A paper feeding device 97 is provided with a recorded paper front end regulating member 206 having its upper end fixed to the specified fixing member and for preventing a plurality of recorded paper sheets from being simultaneously fed to nip parts of a separating roller pair by its lower end, and a recorded paper retaining mechanism 203 having a recorded paper retaining member to be oscillated between the waiting position in which it is to be brought into pressure-contact with the part fixed to the fixing member, of the recorded paper front end regulating member and the retaining position for retaining a plurality of recorded paper sheets arranged in the superposed state in the specified position from above. The recorded paper front end regulating member 206 is constituted of an elastic member 241 to be fixed to the fixing member, and a flexible member 242 having the upper part to be fixed to the elastic member 241 and having the lower end projecting downward from the elastic member 241.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet feeding device in an image forming apparatus such as a copying machine.

[0002]

[Prior art]

Some copying machines can perform double-sided copying. In such a copying machine, the recording paper on which the transfer to the first side has been completed is stored in a state of being superimposed on the intermediate tray. The recording paper stored in the intermediate tray is
After being sent to the re-feeding device, the sheet is fed one by one by the re-feeding device. The recording paper fed by the refeeder
The sheet is sent to the transfer position, and the transfer to the other side is performed.

[0004] As a re-feeding device, there is a re-feeding device which feeds a plurality of recording sheets sent in a state of being superimposed on the re-feeding device one by one from below. As this kind of sheet re-feeding device, for example, a pair of upper and lower separating rollers, a recording paper pressing member, and a recording paper pressed in a state of being overlapped with a standby position where the recording paper pressing member is pressed against a stopper are pressed from above. The recording paper pressing mechanism that swings between the pressing position and the recording paper is disposed below the recording paper, and rotates when a plurality of recording papers are pressed from above by the recording paper pressing member of the recording paper pressing mechanism. In some cases, a paper feed roller for feeding the recording paper to the nip portion of the separating roller pair is provided.

In such a sheet re-feeding device, the recording paper pressing member of the recording paper pressing mechanism is returned from the pressing position to the standby position every time one sheet is fed. At this time, since the recording paper pressing member collides with the stopper, there is a problem that a collision noise is generated each time one sheet is fed.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a paper feeder capable of reducing a collision sound generated when a recording paper pressing member of a recording paper pressing mechanism returns to a standby position. .

In addition, the present invention utilizes a recording paper pressing mechanism of a recording paper pressing mechanism utilizing a recording paper front end regulating member for preventing a plurality of recording papers from being simultaneously fed to a nip portion of a paper feed roller pair. It is an object of the present invention to provide a sheet feeding device capable of reducing a collision sound generated when a member returns to a standby position.

[0008]

SUMMARY OF THE INVENTION A paper feeder according to the present invention is a paper feeder for feeding a plurality of recording papers arranged one above another at a predetermined position one by one from below. , A pair of upper and lower separating rollers, an upper end portion thereof is fixed to a predetermined fixing member, and a recording paper front end regulating member for preventing a plurality of recording sheets from being simultaneously fed to a nip portion of the separating roller pair by a lower end portion. A standby position having a recording paper pressing member, wherein the recording paper pressing member is pressed against a portion of the recording paper front end regulating member fixed to the fixing member;
A recording paper pressing mechanism that swings between a pressing position for pressing a plurality of recording papers arranged in a state of being overlapped at a predetermined position from above, and a recording paper pressing mechanism that is disposed below the recording paper at the predetermined position. A paper feed roller for feeding the recording paper to the nip portion of the pair of separating rollers is provided by rotating the recording paper while the plurality of recording papers are pressed from above by the recording paper pressing mechanism. The restricting member includes an elastic member fixed to the fixing member, and a flexible member having an upper portion fixed to the elastic member and a lower end projecting downward from the elastic member.

The elastic member is formed of, for example, a sponge,
The flexible member is formed of a synthetic resin film.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a copying machine will be described below with reference to the drawings.

[1] Description of Overall Configuration of Copier

FIG. 1 shows the overall configuration of a copying machine.

The copying machine includes a copying machine main body 1 and a paper feeding unit 2 fixed adjacent to the copying machine.

A contact glass 4 is provided on the upper surface of the case 3 of the copying machine body 1. An automatic document feeder 5 is provided above the contact glass 4. A sorter 6 is provided on the side of the case 3 opposite to the side where the sheet feeding unit 2 is located. In Case 3, an exposure mechanism,
A print mechanism and a recording paper transport mechanism are provided.

The printing mechanism has a photosensitive drum 11. Around the photosensitive drum 11, in the order of its rotation, a charger 12 for charging the photosensitive layer on the surface of the photosensitive drum 11, and a blank lamp 1 for forming a margin.
3. a developing device 14 for visualizing the electrostatic latent image formed on the photosensitive layer as a toner visualized image; a transfer discharger 15 for transferring the toner visualized image formed on the photosensitive layer to recording paper; A discharger 16 for separating recording paper from the drum 11,
A cleaning device 17 for removing the toner remaining on the photosensitive drum 11 after the transfer and a static eliminator 18 for removing charges on the surface of the photosensitive drum 11 are provided.

At a position between the charger 12 and the developing device 14 on the surface of the photosensitive drum 11, exposure is performed by irradiating the reflected light from the original to form an electrostatic latent image on the photosensitive layer. Is done.

The exposure mechanism includes an exposure lamp 21 for exposing and scanning an image of a document placed on the contact glass 4.
And a first optical system traveling body 31 provided with a reflection mirror 22 for reflecting light reflected from the original, and second and third mirrors 23 and 24 for guiding the light reflected by the first mirror 22 to the lens 25. And a fourth mirror 26 for guiding the light emitted from the lens 25 to the surface of the photosensitive drum 11.

The first optical system traveling body 31 and the second optical system traveling body 32 are reciprocated in the left-right direction by a scan motor (not shown). The second optical system traveling body 32 moves at a speed that is half the speed of the first optical system traveling body 31 and a distance that is half the moving distance of the first optical system traveling body 31.

The recording paper transport mechanism will be described. For each paper feed cassette 41, 42, 43 in the paper feed unit 2,
Paper feed rollers 51, 52, 53 for feeding recording paper and a pair of separating rollers 54, 55, 56 for preventing double feeding of the fed recording paper are provided.

The recording paper fed from the uppermost paper feed cassette 41 is sent to registration roller pairs 81 and 82 via first to sixth feed roller pairs 61 to 66. The recording paper fed from the middle paper cassette 42 is fed to the registration roller pair 8 via the third to sixth feed roller pairs 63 to 66.
1, 82. The recording paper fed from the lowermost paper feed cassette 43 is fed to the fifth and sixth feed roller pairs 6.
5 and 66 are sent to a pair of registration rollers 81 and 82.

The recording paper sent to the pair of registration rollers 81 and 82 is sent to the transfer position around the photosensitive drum 11 by the pair of registration rollers 81 and 82, and the toner paper formed on the photosensitive drum 11 is exposed. The image is transferred, and thereafter, is separated from the photosensitive drum 11. The recording paper peeled off from the photoconductive drum 11 is sent to a pair of fixing rollers 92 by a conveyor belt 91, and the toner image transferred to the recording paper is fixed on the recording paper. Thereafter, the sheet is discharged onto the sorter 6 by the eighth feed roller pair 68.

In the double-sided copy mode, the recording paper on which the first transfer has been performed on one side passes through a pair of fixing rollers 92, and is then sent to an intermediate tray 96 via a separation claw 93, a stock transport section 94, and a reversing device 95. And the intermediate tray 96
Is stored once. The recording paper stored in the intermediate tray 96 (or a plurality of recording papers when copying images of a plurality of originals) is sent to a re-feeding device 97 by a feeding mechanism (not shown). The plurality of recording sheets sent to the re-feeding device 97
After the sheet is fed one by one by the re-feeding device 97, the ninth to
The sheet is fed to registration roller pairs 81 and 82 via an eleventh feed roller pair 69 to 71 and a sixth feed roller pair 66.

FIG. 2 shows the details of the drive mechanism of the pair of resist rollers 81 and 82.

The shaft 101 to which the upper registration roller 81 is fixed is connected to the frames 111 and 11 supported by the case 3.
2 is rotatably mounted via bearings 113 and 114. Similarly, the shaft 102 to which the lower registration roller 82 is fixed is connected to the frame 1 supported by the case 3.
11 and 112 are rotatably mounted via bearings 115 and 116.

[0025] Both shafts 101, 102 are geared 117,
It is connected via 118. The shaft 101 is the gear 12
1, 122 are connected to a shaft 123 driven by a motor (not shown). Therefore, when the shaft 123 is rotationally driven, the upper shaft 101 rotates, and accordingly, the lower shaft 102 also rotates.

The bearing 11 supporting the lower shaft 102
5, 116 are attached to the frames 111, 112 so as to be able to move up and down by a small amount. These bearings 115 and 116 are urged upward against the frames 111 and 112 by compression springs 124 and 125. As a result, the lower roller 82 comes into pressure contact with the upper roller 81.

When the recording paper is sent to the pair of registration rollers 81 and 82, the pair of registration rollers 8
Numerals 1 and 82 are in a driving stop state. However, when the recording paper sent to the pair of registration rollers 81 and 82 collides with the pair of registration rollers 81 and 82, the pair of registration rollers 81 and 82 idles, and the recording paper moves between the pair of registration rollers 81 and 82. There is a possibility that such a situation may occur. When this occurs, the transfer position to the recording paper is shifted.

Therefore, in this embodiment, a torque limiter 130 is provided on the shaft 101 as shown in FIGS. The torque limiter 130 includes an inner race 131 and an outer race 132 as is well known.
The inner ring 131 of the torque limiter 130 is fixed to the shaft 101 by a spring pin 133. The outer ring 132 of the torque limiter 130 is fixed to the frames 111 and 112 via a mounting member 134 and the like.

As the torque limiter 130, the inner ring 131 and the outer ring 132 are always connected with a predetermined connecting force by a magnetic force, a spring, or the like, and a predetermined rotational torque is applied to the inner ring 131 in the recording paper feed direction. When the inner ring 131 is rotated relative to the outer ring 132, a structure is used in which the connecting force is weakened when the inner ring 131 rotates.

More specifically, a torque limiter 130 is used that rotates the inner ring 131 with respect to the outer ring 132 when a rotation torque of 800 gfcm or more is applied to the inner ring 131 in the recording paper feed direction. When the shaft 123 is driven to rotate, the gears 122 and 121 and the shaft 10
1 to the inner ring 131 in the recording paper feed direction by about 5 kgf.
cm of rotation torque is applied, and the inner race 131
Rotate against. That is, the shaft 101 rotates.

On the other hand, when the shaft 123 is not driven to rotate, even if the recording paper collides with the pair of registration rollers 81 and 82, the inner ring 131 (shaft 101) is actuated by the coupling force acting between the inner ring 131 and the outer ring 132. Does not rotate, that is, since the registration roller pairs 81 and 82 do not idle,
It is possible to prevent the recording paper from entering between the pair of registration rollers 81 and 82.

FIG. 4 shows the details of the re-feeding device 97.

The re-feeding device 97 is a device for feeding the recording sheets sent in a state of being superposed on the re-feeding device 97 one by one from below. The re-feeding device 97 includes a pair of separating rollers 201 and 202, a recording paper pressing mechanism 203 for pressing the superposed recording paper from above, and a state in which the recording paper is pressed from above by the recording paper pressing mechanism 203. The paper feed roller 204 feeds the recording paper to the nip portion of the separating roller pair 201, 202 by the rotation of the cleaning roller 205 and the nip portion of the separating roller pair 201, 202 for removing dirt from the separating roller pair 201, 202. A recording paper front end regulating member 206 for preventing a plurality of recording papers from being fed to the printer.

The pair of separating rollers 201 and 202 is composed of a reverse rotation roller 201 and a normal rotation roller 202 arranged at the center of the width of the recording paper transport path so as to sandwich the recording paper transport path vertically. The upper roller is a reverse roller 201, and the lower roller is a forward roller 202.
It is. The normal rotation roller 202 is driven to rotate in the recording paper feed direction by a drive mechanism (not shown).

The reverse rotation roller 201 is driven to rotate the recording paper in a direction opposite to the recording paper feeding direction (recording paper return direction) by a driving mechanism (not shown). For the reverse roller 201, a torque limiter (not shown) for canceling power transmission from a drive source to the reverse roller 201 when the torque in the recording paper feed direction transmitted to the reverse roller 201 becomes a predetermined value or more. Is provided.

The two paper feed rollers 204 are attached to a shaft 211 disposed below the recording paper conveyance path and extending in a direction perpendicular to the recording paper conveyance direction, with an interval in the axial direction. The cross-sectional shape of the paper feed roller 201 is a missing circle in which a part of a circle is missing. The feed roller 204 is always
As shown by the solid line in FIG. 4, the motor is stopped at a rotational position where the missing portion is directed upward.

The recording paper pressing mechanism 203 is provided with a pair of arms 221 provided on both sides of the recording paper transport path and swinging around the lower end, and a recording paper pressing member attached between the upper ends of both arms 221. 222.

The recording paper pressing member 222 includes two arms 221.
A pair of mounting plate portions 231 rotatably mounted via pins 223 to the upper end portions of the mounting plates 231, and a curved plate portion 232 formed between the mounting plate portions 231. A bent portion 232a is formed at the lower end of the curved plate portion 232.

The arm 221 is normally urged in a clockwise direction by a tension spring (arm urging spring) (not shown). As shown by a solid line in FIG. The portion 232a is stopped in a state where the tip of the portion 232a contacts the regulating member 206. This stop position is referred to as a standby position.

When the recording paper is fed, the arm 221 is swung counterclockwise by operating an arm driving solenoid (not shown), and as shown by a chain line in FIG. The pressing member 222 presses the recording paper from above. This position is referred to as a waiting pressing position. Then, when the operation of the arm driving solenoid is stopped, the arm 221 is returned to the standby position by the urging force of the arm urging spring.

The cleaning roller 205 is in pressure contact with the forward roller 202 of the pair of separating rollers 201 and 202, and rotates with the rotation of the forward roller 202. The cleaning roller 205 is made of silicon rubber. As the rubber hardness of the silicon rubber, a rubber hardness lower than the rubber hardness of the pair of separating rollers 201 and 202 is used. Since the rubber hardness of the pair of separating rollers 201 and 202 is about 30 degrees, the rubber hardness of the silicone rubber used for the cleaning roller 20 is preferably 20 degrees or less, and more preferably 10 degrees or less. In this embodiment, as the silicone rubber used for the cleaning roller 205, silicone rubber having a rubber hardness of 5 degrees is used. Also,
In this embodiment, a scraper 207 for scraping the surface of the cleaning roller 205 little by little is provided in a state of being pressed against the cleaning roller 205.

The recording paper front end regulating members 206 are respectively attached to a pair of fixing members 213 disposed outside the both ends of the separating roller 201. The fixing member 213 is supported by the case 3 of the copying machine main body 1 and has a vertical surface 213a facing the direction opposite to the recording paper transport direction.

The recording paper front end regulating member 206 is a fixing member 2
13, an elastic member 241 fixed to the vertical surface 213a,
The flexible member 242 is fixed to the elastic member 241 and has a lower end extending below the elastic member 241. The elastic member 241 is formed of a thin plate sponge, and the flexible member 242 is formed of a synthetic resin film.

The operation of the sheet re-feeding device 97 will be described.

When a plurality of recording sheets are sent to the re-feeding device 97, the re-feeding device 97 performs a feeding operation at predetermined time intervals. One recording sheet is fed by one sheet feeding operation.

One sheet feeding operation is performed as follows. First, when the arm driving solenoid is operated, the arm 221 of the recording paper pressing mechanism 203 swings counterclockwise, and the recording paper pressing member 222 is moved to the pressing position shown by the chain line in FIG. .

In this state, the paper feed roller 204 is rotated to separate the recording paper from the pair of rollers 201 and 201.
It is sent to the nip 202. At the same time, the pair of separating rollers 201 and 202 are driven to rotate, and one sheet of recording paper is fed.

When the feeding of one sheet is completed, the operation of the arm driving solenoid is stopped, and the driving of the sheet feeding roller 204 and the pair of separating rollers 201 and 202 are stopped.

When the operation of the arm driving solenoid is stopped, the arm 221 is swung clockwise by the urging force of the arm urging spring and returns to the standby position. When the arm 221 returns to the standby position, the leading end of the folded portion 232a of the recording paper pressing member 222 is
13 collides with the regulating member 206 fixed to the thirteen. Since the regulating member 206 is constituted by the elastic member 241 made of sponge and the flexible member 242 made of film, the collision sound when the recording paper pressing mechanism 203 returns to the standby position can be extremely reduced.

By the way, when the sheet feeding operation is repeatedly performed, the toner and the paper dust adhere to the separating roller pair 201 and 202. The cleaning roller 205 rotates with the rotation of the normal rotation roller 202 in a state where the cleaning roller 205 is pressed against the normal rotation roller 202 of the pair of separation rollers 201 and 202, so that the toner and paper dust adhering to the normal rotation roller 202 are removed from the cleaning roller 205. Adsorb to.

In this embodiment, the cleaning roller 205 is made of silicon rubber having a lower hardness than the pair of separating rollers 201 and 202.
The toner and paper dust attached to the cleaning roller 205 are efficiently adsorbed by the cleaning roller 205. Further, silicone oil may adhere to the recording paper fed by the paper re-feeding device during the first fixing process on one side, but since the cleaning roller 205 is formed of silicone rubber, the silicone rubber is not cleaned. The cleaning roller 205 does not deteriorate even if it adheres to the roller 205.

Since the surface of the cleaning roller 205 is scraped off little by little by the scraper 207,
The high toner and paper powder attraction of the cleaning roller 205 can be maintained for a long period of time. When the cleaning roller 205 has been consumed to some extent or more, it may be replaced.

[0053]

According to the present invention, it is possible to obtain a paper feeder capable of reducing the collision noise generated when the recording paper pressing member of the recording paper pressing mechanism returns to the standby position.

Further, according to the present invention, the recording paper pressing mechanism of the recording paper pressing mechanism utilizes the recording paper front end regulating member for preventing a plurality of recording papers from being fed to the nip portion of the separating roller pair. A sheet feeding device capable of reducing the collision sound generated when the member returns to the standby position can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing an overall configuration of a copying machine.

FIG. 2 is a side view showing details of a drive mechanism of a pair of resist rollers.

FIG. 3 is a partially enlarged sectional view of FIG. 2;

FIG. 4 is a cross-sectional view illustrating a configuration of a sheet re-feeding device.

[Explanation of symbols]

 81, 82 Registration roller pair 130 Torque limiter 97 Re-feeding device 201, 202 Separation roller pair 203 Recording paper pressing mechanism 204 Paper feeding roller 205 Cleaning roller 206 Recording paper front end regulating member 207 Scraper 213 Fixing member 221 Arm 222 Recording paper pressing member 241 first elastic member 242 second elastic member

Claims (2)

[Claims] 1. A sheet feeding device for feeding a plurality of recording sheets arranged one above another at a predetermined position one by one from below, wherein a pair of upper and lower separating rollers and an upper end are provided. A recording paper front end regulating member for preventing a plurality of recording papers from being simultaneously fed to a nip portion of the separating roller pair by a lower end portion, a recording paper pressing member, and a recording paper pressing member A standby position in which the member presses against a portion of the recording paper front end regulating member that is fixed to the fixing member, and a pressing position in which a plurality of recording papers arranged in a state of being superimposed on a predetermined position are pressed from above. A recording paper pressing mechanism that swings between the recording papers, and a recording paper pressing mechanism that is arranged below the recording paper at the predetermined position, and is rotated while a plurality of recording papers are pressed from above by the recording paper pressing mechanism. A paper feed roller for feeding the recording paper to the nip portion of the pair of separating rollers. The recording paper front end regulating member has an elastic member fixed to the fixing member, and an upper end fixed to the elastic member and a lower end fixed to the elastic member. A sheet feeding device, wherein the portion comprises a flexible member protruding below the elastic member. 2. The elastic member is formed of a sponge,
The paper feeding device according to claim 1, wherein the flexible member is formed of a synthetic resin film.