JP2001039566A - Sheet feeding device and picture image formation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent vibration of a separation pad by receiving force of a separation roller at the time of separating sheets by the separation roller and the separation pad to be pressure contacted on the separation roller. SOLUTION: Vibration of a separation pad 73 is prevented by covering a revolving fulcrum shaft 74a of a separation pad holder 74 holding the separation pad 73 with a rubber bush 51 which is a viscoelastic member on a sheet feeding device furnished with a separation rover to deliver sheets from a cassette loading a plural number of the sheets on it and the separation pad 73 to separate the sheets one by one between the separation roller by being pressure contacted on the separation roller.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet feeding apparatus used for an image forming apparatus such as a facsimile, a printer, a copying machine and the like, and an image forming apparatus provided with the sheet feeding apparatus.

[0002]

2. Description of the Related Art Conventionally, as a sheet separation mechanism in a sheet feeding apparatus, a claw separation method, a friction piece separation method, a reverse rotation roller method and the like are known. Among them, the friction separation method is considered to be a separation mechanism that is balanced in terms of cost and performance.
However, this method is liable to generate squealing (chattering), and it is necessary to consider the material of the pad and the supporting method thereof.

[0003] As shown in Japanese Patent Publication No. 55-21696, by providing a fulcrum in the tangential direction at the contact portion between the roller and the pad, the pad is constructed so as not to be easily inserted or escaped. If the pad is too easy to penetrate or escape, the pad pressure becomes unstable, and the separation performance is likely to be affected.

[0004]

In the above-mentioned prior art, since the pad tends to move in the direction of the force received, if there is play at the fulcrum, the pad separates when the sheet passes through the roller and the pad contact portion. There is a disadvantage that the pressure becomes unstable or a chattering sound is generated.

Accordingly, the present invention can stabilize the separation pressure (pressing force) generated between the separation pad and the separation roller,
An object of the present invention is to prevent separation pad squeal by absorbing the force received by the separation pad.

[0006]

In order to achieve the above object, a sheet feeding apparatus according to the present invention comprises: a sheet stacking means for storing a plurality of sheets; a sheet feeding means for feeding sheets from the sheet stacking means; A separating unit that is disposed so as to be able to approach and separate from the feeding unit and cooperates with the feeding unit to separate sheets one by one; and a separation unit that urges the separating unit toward the feeding unit. A sheet urging device having a rotation fulcrum shaft provided on a tangent line of the feeding means passing through a contact portion between the feeding means and the separation means; A viscoelastic member is fitted to the outside.

The separating means has a friction member which comes into contact with the feeding means, and an arm portion which supports the friction member and is swingable about the rotation fulcrum shaft. The friction member is urged toward a feeding unit.

The friction member is held by a friction member holder, and the friction member holder is swingably supported by the arm in the width direction of the sheet.

The sheet stacking means is detachably supported by the apparatus main body.

[0010] The invention is characterized in that a guide for guiding the sheet separated by the separating means along the feeding means is provided on the arm portion.

Further, according to the present invention, there is provided a sheet stacking means for accommodating a plurality of sheets, a feeding means for feeding out the sheets from the sheet stacking means, and a sheet feeding means arranged so as to be able to approach and separate from the feeding means. A sheet feeding device including a separating unit that separates sheets one by one in cooperation with the unit, and a separating unit urging unit that urges the separating unit toward the feeding unit.
A rotation fulcrum shaft of the separation unit is provided on the separation unit side with respect to a tangent line of the feeding unit passing through a contact portion between the feeding unit and the separation unit, and a viscoelastic member is externally fitted to the rotation fulcrum shaft. It is characterized by.

The separating means has a friction member which comes into contact with the feeding means, and an arm portion which supports the friction member and is swingable about the rotation fulcrum shaft. The friction member is urged toward a feeding unit.

The friction member is held by a friction member holder, and the friction member holder is swingably supported in the width direction of the sheet with respect to the arm portion.

The sheet stacking means is detachably supported by the apparatus main body.

A guide for guiding the sheet separated by the separating means along the feeding means is provided on the arm portion.

[0016]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIGS. 1 to 12 show an embodiment of a sheet feeding apparatus according to the present embodiment, and particularly illustrate a separating section for separating and feeding a sheet.

In these figures, reference numeral 13 denotes a cassette as a sheet stacking means, and a plurality of sheets P are stacked on the cassette 13 (FIGS. 6 and 1).
0). As shown in FIG. 10, in the cassette 13, width regulating plates 32, 33 for regulating the position of the sheet in the width direction are provided.
Are arranged respectively. And one width regulating plate 3
3, a side pressure spring 33a for urging the sheet bundle toward the one width regulating plate 32 is attached. Claws 35, 35 for suppressing the sheet from curling are formed at the paper feed side ends (right ends in FIG. 10) of these width regulating plates 32, 33, respectively.

A rear end regulating plate 34 for regulating the position of the rear end (left end in FIG. 10) of the sheet is provided in the cassette 13.
Is to be attached.

Further, an intermediate plate 36 for stacking and supporting sheets is arranged at the bottom of the cassette 13. As shown in FIGS. 6 and 10, the intermediate plate 36 is urged (rotated) toward a later-described separation roller (feeding means) 60 by a lifter arm (feeding force applying means) 38. Has become.

The lifter arm 38 is attached to a lifter shaft (support shaft) 37 as shown in FIGS. As shown in FIG. 10, both ends of the lifter shaft 37 are rotatably supported by bearings 69 fixed to the apparatus main body 1. A lifter lever 39 is attached to one end of the lifter shaft 37 (upper right end in FIG. 10). As shown in FIGS. 10 and 11, the end of the lifter lever 39 is always a lifter spring (tension spring) 40.
It is attached to one end side. The lifter lever 39 is, as shown in FIG.
At 8, the lifter spring 40 urges the middle plate 36 in the direction of lifting.

Reference numeral 60 denotes a separation roller serving as a feeding means. As shown in FIG. 5, the separation roller 60 has, on its end face, a projection 60a which meshes with the projections 50a (four places) of the one-way clutch 50. Have been. The convex portion 50a and the convex portion 60a are engaged with a play of 40 °, and have a so-called mechanical timer structure. Therefore,
The separation roller 60 can rotate relative to the one-way clutch 50 by 40 degrees. The one-way clutch 50 and the projection 60a of the separation roller 60 constitute a power transmission unit that connects the separation roller shaft 62 as a driving unit and the separation roller 60 so that they can rotate relative to each other by a predetermined angle. Note that the relative rotation angle between the separation roller 60 and the one-way clutch 50 can be appropriately set in relation to separation means described later.

The separation roller 60 is attached to a separation roller shaft (drive means) 62 via a one-way clutch 50 as shown in detail in FIG.
In addition, it is connected to a power source (not shown) via an input clutch 61 attached to one end of the separation roller shaft 62.
The separation roller shaft 62 is rotatably supported by a bearing 63 fixed to an apparatus body (not shown), and a separation cam (feed regulating means) 64 is mounted on one end side to which the input clutch 61 is mounted. Have been. FIG.
As shown in (d), the separation cam 64 and the lifter lever 39
A space 65 is formed between the two.

A distal end projection 70 is integrally formed at the distal end of the cassette orchest 31 (see FIGS. 6 to 8). Then, when the cassette orchestra 31 is mounted in the apparatus main body 1,
The separation lever 71 abutting on the tip protrusion 70 is rotatably supported by the lifter shaft 37 (FIGS. 6 to 8).
reference). A separation spring (compression coil spring) 72 as a first urging means is mounted above the separation lever 71 in FIGS. 6 and 7.
Urges the friction member 73a of the elastic separation pad 73 toward the separation roller 60 side. The separation lever 71 and the separation spring 72 constitute a biasing unit that biases a separation unit described below toward the separation roller 60.

The separation means has a separation pad 73 and a separation pad holder 74.
As shown in FIG.
It is mounted so that it can swing. Separation pad holder 7
Reference numeral 4 is attached to the apparatus main body 1 via a fulcrum shaft 74a so as to be rotatable.

The fulcrum shaft 74a of the separation pad holder 74 is
It is located on a tangent to the outer periphery of the separation roller passing through the contact portion between the separation roller 60 and the separation pad 73, and the force received by the separation pad 73 due to the rotation of the separation roller 60 does not affect the pressure contact force of the separation spring 72. (FIG. 3).

The fulcrum shaft 74a of the separation pad holder 74 is inserted into the U-shaped groove 41 provided in the main body 1 and is positioned by the holding claw 42 (FIGS. 2 and 3), so that the assembling property is good and the component cost is low. .

The fulcrum shaft 74 of the separation pad holder 74
A is covered with a rubber bush 51 on both shafts (FIG. 1). The inner diameter of the rubber bush 51 is a fulcrum shaft 74a.
Is set slightly smaller than the outer diameter dimension of. The separation pad holder 74 is mounted by dropping the fulcrum shaft 74a over the rubber bush 51 and inserting the support shaft 74a into the U-shaped groove 41 as described above, and pressing down from above with the pressing claws 42 (FIG. 2).

The outer diameter of the fulcrum shaft 74a with the rubber bush 51 covered is slightly smaller than the clearance (vertical dimension) between the bottom of the U-groove 41 in the horizontal direction and the bottom of the U-groove and the bottom of the holding claw 42. Is set to large. The outer diameter of only the fulcrum shaft 74a is set slightly smaller than the horizontal and vertical dimensions.

The rubber bush 51 is preferably a member having viscoelasticity, and is made of foamed or solid natural or synthetic rubber. A material having a vibration damping effect is more preferable, and a resin (polymer) that can obtain the same effect may be used.

When the separation roller 60 is rotated in the J direction to feed a sheet as shown in FIG. 3, the separation pad 73 receives a tangential force A from the rotation. Fulcrum shaft 7
If the fitting A is present between the fulcrum shaft 74a, the U-shaped groove 41, and the pressing claw 42 when the force A is applied to 4a, the separation pad 73 moves and vibrates, causing "pad squeal".

In the present embodiment, the rubber bush 5
1 eliminates the fitting backlash, so that "pad squeal" generated at the time of sheet feeding can be suppressed. In addition, the vibration caused by the intermittent frictional force change between the sheet and the separation pad 73 can be absorbed by the viscoelastic property of the rubber bush 51. Therefore, the chattering sound of the separation pad 73 can be prevented and the quiet sheet can be produced. Feeding can be done.

Further, since the viscoelastic property of the rubber bush 51 is set so as not to prevent the rotation of the separation pad 73 due to its own weight, when the cassette 13 is pulled out from the apparatus main body 1, the separation pad 73 is separated from the separation roller. 60 can be easily separated. For this reason, the sheet is
There is no problem of remaining in the inside.

Reference numeral 77 denotes a convex portion formed on the apparatus main body 1.
When the cassette orifice 31 is detached from the apparatus main body 1, the projection 77 comes into contact with the separation lever 71 pressed by the separation spring 72 (FIG. 8).

Next, the operation of the sheet feeding unit will be described.

FIGS. 6 and 7 show that the cassette section 13 is the main body 1 of the apparatus.
1 shows a state where the camera is mounted on the camera. FIG. 8 shows a state in which the cassette unit 13 has been removed from the apparatus main body 1. 6 to 8 are views in which the rear cover 28 is closed.

The separation pad 73 includes a separation pad holder 74
A step screw 76 is attached to the front end so that the head can be swung (oscillated) as indicated by the arrow shown in FIG. As a result, the separation pad 7 is
3 no longer hits the recording sheet,
The occurrence of skewing and double feeding of sheets can be suppressed (equalizing mechanism).

As described above, the separation lever 71 is rotatably supported by the lifter shaft 37. A separation spring 72 is provided between the separation pad holder 74 and the separation lever 71. When the cassette unit 13 is mounted on the apparatus main body 1, the tip protrusion 70 of the cassette orch 31 pushes up the separation lever 71. At this time, the separation pad 73
Is biased to the separation roller 60 at a predetermined separation pressure G (2N in the present embodiment) by the repulsive force (spring force) of the separation spring 72 (FIG. 6).

At this time, a receiving boss (having a dimension and a shape such that it enters under the front end projection 70 when the front end projection 70 of the cassette orchment 31 is inserted to a predetermined position is attached to the bottom plate 1a of the apparatus main body 1. Support projections, support means) 113 are formed. The receiving boss 113 protrudes from the bottom plate 1a toward the separation lever 71, and is formed to have a height such that a small clearance is formed between the receiving boss 113 and the tip projection 70, and the weight of the cassette 13 directly acts. Is prevented from doing so.

Immediately below (corresponding position) of the receiving boss 113, there is provided a leg (support means) 112 projecting from the apparatus main body 1 to the outside of the apparatus and in contact with the main body installation surface.

As a result, even if the distal end projection 70 of the cassette orch 31 receiving the reaction force of the separation spring 72 is deformed downward,
The amount of deformation is a very small amount before contacting the receiving boss 113, and the leg 112 located at a position corresponding to the receiving boss 113 allows the apparatus main body 1 to mount the apparatus main body 1 on the main body installation surface (usually a desk or the like on which the apparatus is placed). As a result, the tip protrusion 70 of the cassette orchestra 31 is prevented from being further bent and deformed, and a desired separation pressure is generated between the separation roller 60 and the separation pad 73. (See FIG. 6).

Accordingly, the separation roller 6 by the separation spring 72
The value of the separation pressure G between 0 and the separation pad 73 is stabilized, and the separation performance of the sheet by both these 60 and 73 is stabilized. In addition, since the reaction force received by the distal end projection 70 of the cassette 31 is in the direction normal to the mounting direction of the cassette unit 13,
A reaction force is not received in the mounting direction of the cassette section 13, and the mounting position of the cassette section 13 with respect to the apparatus main body 1 is stabilized.

Next, as shown in FIG.
Is detached from the apparatus main body 1, the leading end projection 70 of the cassette orchest 31 is separated from the separation lever 71, so that the separation lever 71 is separated from the separation pad 73 and the separation pad holder 74.
Due to its own weight, it rotates clockwise until it comes into contact with the convex portion 77.

As a result, the separation pad 73 and the separation roller 6
0 is released and the separation pressure is released. And the separation pad 7
3 and the separation roller 60 become free, and the recording sheet is pulled out together with the cassette portion 13 when the cassette portion 13 is pulled out of the apparatus main body 1. Therefore, the separation pad 73 and the separation roller 60 are separated. There is no remaining sheet between them.

Next, the operation of the cassette section 13 will be described with reference to FIG. 12 (when the number of stacked recording sheets P is small).

The paper feeding operation immediately after the cassette section 13 is mounted on the apparatus main body 1 will be described (FIG. 12). Lifter shaft 37
, A lifter lever 39 and a lifter arm 38 are respectively fixed, and are integrally rotated. The lifter spring 40 has one end attached to a main frame hook (not shown) and the other end attached to a hook 39 a of the lifter lever 39, and biases the lifter lever 39 toward the separation roller 60.

In the paper feed standby state, the lifter lever 39 urged by the lifter spring 40 abuts on the separation cam 64 disposed coaxially with the separation roller 60, and its rotation is restricted (FIG. 12A). ).

When a pickup solenoid (not shown) is activated, the input clutch 61 enters a drive transmission state, and when the separation cam 64 starts rotating, the separation roller shaft 62 connected to the separation cam 64 rotates. In FIG. 6, a one-way clutch 50 that transmits torque when the separation roller shaft 62 rotates in the J direction and rotation resistance in the direction opposite to the J direction acts on the separation roller 60 in FIG.
Is inlaid. Therefore, since the convex portion 50a provided on the one-way clutch 50 and the convex portion of the separation roller 60 mesh with each other as described above, the separation cam 64 side (the separation roller shaft 6).
The rotation of 2) is transmitted to the separation roller 60 (FIGS. 5, 6, and 12A).

Next, when the lifter lever 39 rotates along the outer peripheral shape of the separation cam 64 and the lifter lever 39 rotates clockwise in FIG.
6 is pushed up to the separation roller 60 side (FIG. 12B).
(C)).

At this time, since the lifter arm 38 pushes up the middle plate 36 (the weight of the middle plate 36 and the weight of the recording sheet P) on which a plurality of sheets are stacked, the lifter shaft 37 acts on the reaction force H acting downward in the figure. (FIG. 12B). Immediately below the bearing 69 that rotatably supports the lifter shaft 37, legs 110 and 111 projecting from the apparatus main body 1 to the outside and supporting the apparatus main body 1 on the main body installation surface are formed. reference). As described above, the installation portion (apparatus main body 1) of the bearing 69 that rotatably supports the lifter shaft 37 is the leg 1
Since it is supported on the installation surface at 10, 111, the lifter shaft 39
Position does not change. Therefore, the amount by which the lifter arm 38 pushes up the middle plate 36 is stabilized, the loss of the force for pushing up the middle plate 36 by the lifter arm 38 is eliminated, and the force of pressing the middle plate 36 by the lifter arm 38 becomes stable, and the separation by the separation roller 60 is performed. The performance (paper feeding performance) is also stabilized.

Further, the separation roller 60 and the separation cam 64
Is rotated, the recording sheet P on the middle plate front end portion 67 comes into contact with the separation roller 60, and when a space 65 is generated between the separation cam 64 and the lifter lever 39, the lifter spring 4
The recording sheet P stacked on the middle plate 36 by the urging force of 0
Is pressed against the separation roller 60, and only one recording sheet P is pulled out (fed) by the separation roller 60.
(FIGS. 12D and 12E).

Further, the separation roller 60 and the separation cam 64
When the lifter lever 39 is pushed down by the separation cam 64, the lifter arm 38 rotates in a direction away from the separation roller 60, and the middle plate 36 rotates so as to descend by its own weight (FIG. 12 (f)).

Further, the separation roller 60 and the separation cam 64
Rotates, the intermediate plate 36 returns to the initial position (FIG. 12 (g)).

12 (g) to 12 (h), the recording sheet P
No pressing force by the middle plate 36 works. However, since the recording sheet P is sandwiched between the separation roller 60 and the separation pad 73 as shown in FIG. 6, the recording sheet P is separated one by one by the separation roller 60 and the separation pad 73, and the separated sheets are separated. It is transported along the guide 75.

After the rotation of the separation roller shaft 62 and the separation cam 64 is completed, the recording sheet P is conveyed by the rotation of the conveyance roller 29, and the recording sheet P is loosened between the separation roller 60 and the separation roller 60. Is driven. At this time, the separation roller 60 rotates in the J direction by the amount of play with the one-way clutch 50 (until the protrusions 50a and 60a come into contact with each other) (40 °), and the protrusion 60a After contact with the portion 50a, the locked state with the separation roller shaft 62 is released by the one-way clutch 50, and follows the movement of the recording sheet P as described above (FIG. 12).
(H), FIG. 7).

When the rear end of the recording sheet P passes through the nip between the separation roller 60 and the separation pad 73, the rotation of the separation roller 60 and the one-way clutch 50 is stopped. Recording sheet P
Is completed, the intermediate plate 36 and the like return to the standby state (FIGS. 12 (h) to 12 (a)). Next, as shown in FIG.
When the cassette portion 13 is removed from the apparatus main body 1, the tip projection 70 of the cassette orch 31 is separated from the separation lever 71, so that the separation lever 71 comes into contact with the convex portion 77 by the weight of the separation pad 73 and the separation pad holder 74. Rotate clockwise in the figure. As a result, the separation pad 73
The separation pressure between the separation pad 73 and the separation roller 60 is released.

At this time, the separation pad 73 and the separation roller 6
The recording sheet P sandwiched between the recording rollers P is liable to stay in the contact portion with the separation roller 60 due to friction generated in the contact portion with the separation roller 60. However, the separation roller 60 has a play in the mechanical timer structure (power transmission means). Minute (ie, the protrusion 60
a can be rotated in the K direction by a predetermined angle (40 ° in the present embodiment) until the cassette portion 1 a contacts the convex portion 50a.
3 is pulled out of the apparatus body 1, the cassette unit 1
3 (see FIGS. 7 and 8).

As a result, the sheet feeding apparatus L according to the present embodiment does not cause a problem that the recording sheet P remains on the separation roller 60 when the cassette section 13 is pulled out from the apparatus main body 1.

As shown in FIG. 9, the play angle of the mechanical timer structure (the relative rotation angle between the separation roller 60 and the one-way clutch 50) is made larger than the angle occupied by the separation pad 73 (40 °). > 38 °), it is possible to secure a sufficient margin for preventing the remaining recording sheet. In other words, the length of the separation roller 60 in rolling contact with the recording sheet P is longer than the length of the contact surface of the separation pad 73 with the recording sheet P in the sheet conveyance direction.

When recording (image formation) on the recording sheet P is continuously performed without pulling out the cassette unit 13 from the apparatus main body 1, the separation roller 60 and the one-way clutch 50 are shown in FIG. The next recording operation is performed from the position.

First, when the rotation of the separation cam 64 starts,
When the rotation of the separation roller shaft 62 and the one-way clutch 50 is rotated by 40 °, the play of the mechanical timer is absorbed, and the separation roller 60 is
And start rotating together.

At this time, if the cam shape of the separation cam 64 is set to a shape that immediately raises the middle plate 36 from the standby position, the load on the mechanical timer structure (power transmission means) is small. Separation roller shaft 62
Is biased in the rotation direction by the spring force of the lifter spring 40, and the separation cam 64 and the separation roller shaft 62 rotate at a higher speed than the setting. As a result, the one-way clutch 50 and the projections 50a, 60a of the separation roller 60 abut against each other, and the impact noise may cause noise in a quiet office or the like.

Therefore, in the present embodiment, in order to reduce the collision between the projections 50a and 60a, FIG.
As shown in the figure, the angle between the standby position of the separation cam 64 and the play (40 °) between the convex portions 50a and 60a is equal to or more than
The cam radius of the separation cam 64 is made constant (shaded portion in FIG. 12), and after the projections 50a and 60a
6 rises. Thus, the separation cam 6
By keeping the radius of the projection 4 constant, at least the projection 50
Until the a and 60a mesh with each other, the spring force of the lifter spring 40 acts on the separation cam 64 in the direction of the rotation center, and the spring force of the lifter spring 40 does not act as a biasing force in the rotation direction of the separation cam 64. In addition, the impact when the projections 50a and 60a mesh with each other is reduced, and the impact sound when the projections 50a and 60a abut against each other is suppressed.

In the present embodiment, the projections 50a, 50
The play of 0a (the relative rotation angle between the one-way clutch 50 and the separation roller 60) is set to 40 °, but is not limited to this, and may be set to another angle as described above.

When the number of recording sheets stacked is large,
The timing (time) from when the middle plate 36 starts to rise to when it comes into contact with the separation roller 60 is advanced.
Basic operations of the zero and the separation cam 64 are the same as those when the number of stacked sheets is small.

(Image Forming Apparatus) FIGS. 13 and 14 illustrate a facsimile apparatus as an image forming apparatus using the sheet feeding apparatus L as an example.

In FIGS. 13 and 14, reference numeral 1 denotes an apparatus main body, 2 denotes a cartridge cover, and an original mounting table configured to be able to stack a plurality of originals S, and 3 reads image information of the original S. An image reading unit, 4 is a recording apparatus main body composed of a laser beam printer, 5 is a document conveying unit, 6 is a document pressing unit, 7 is a contact image sensor, 8
Is a document discharge tray, 9 is a laser scanner, 10 is an image forming unit (image forming means), 11 is a manual feed unit, 12 is a face-down recording sheet discharge tray, 13 is a cassette unit,
4 is a recording paper transport path switching flapper, 15 is a face down guide, 16 is an upper document guide, 17 is a lower document guide,
25 is an operation unit, 26 is a display unit, 27 is a transport guide, 28
Denotes a rear cover, and 29 denotes a transport roller.

The image reading section 3 first separates and feeds the originals (sheets) S stacked on the original placing table 2 one by one by a separation roller 19 which presses against the friction piece 18, and then separates the separated originals. The original is conveyed to the contact type image sensor 7 by the paper feed roller 21 pressed by the pressing spring 20 and the paper feed roller 22 pressed against the paper feed roller 21, and the original is contacted by the original pressing portion 6 to the contact type image sensor. After the image information of the original S is read by the contact image sensor 7, the original S is pressed by the pressing spring 20.
The document is discharged to the document discharge tray 8 by a paper discharge roller 3 and a paper discharge roller 24 which is pressed against the paper discharge roller 23. During this time, the document S is guided by the upper document guide 16 and the lower document guide 17.

A slider 2 slidable in a direction perpendicular to the direction of transport of the original S (in the width direction of the original S) is provided on the original placing table 2.
a is provided. Then, both sides of the document S stacked on the document table 2 can be aligned by the slider 2a. When the document S is a long document, the rear end of the document S can be prevented from protruding from the document table 2 and hanging down by the document tray 2b.

The recording apparatus body 4 emits a modulation signal from the laser beam transmitter 9a of the laser scanner 9 based on the image signal output from the control section 301, and outputs this modulation beam to the image forming section 10 by the polygon mirror 9b. The photosensitive drum 10a is irradiated as a scanning light to the photosensitive drum 10a.
a, image information is formed on the surface, the image information is transferred to the recording paper P fed from the manual paper feeding unit 11 or the cassette unit 13 to the image forming unit 10 and fixed, and then the recording paper P is transferred to the recording paper P. It is configured to discharge paper to the stacking tray 12.

The photosensitive drum 10a includes a primary charger 10b.
And a developer roller 10c and a cleaning blade (not shown) are integrally incorporated in the recording cartridge 10a, and are configured to be detachable from the apparatus main body 1. When the surface of the photosensitive drum 10a is uniformly charged by the primary charger 10b and the surface is irradiated with the scanning light sent from the polygon mirror 9b via the return mirror 9c, a latent image is formed on the surface. Is formed, and the latent image is visualized by the toner supplied from the developing roller 10c.

A transfer charger 10f is arranged around the photosensitive drum 10a of the image forming section 10. Further, a thermal fixing device 10g, a pair of paper discharge rollers 10h, and a pair of face-down paper discharge rollers 10j are arranged in the recording paper conveyance path downstream of the photosensitive drum 10a.

After the toner image formed on the surface of the photosensitive drum 10a is transferred to the recording paper P by the transfer charger 10f,
The toner image is conveyed along the conveyance guide 27, the toner image is fixed by the heat fixing device 10g, and then sent to a pair of paper discharge rollers 10h.

The user can select one of two output modes of the recording paper P (so-called face-down discharge and face-up discharge). Here, face-down paper discharge refers to a paper discharge mode in which the print surface of the document is directed downward and the output pages are arranged in order. The face-up paper discharge means a format in which the printed surface is directed upward so that the output contents can be checked even during paper discharge. The switching between the two types is performed by moving the recording paper transport step switching flapper 14 to switch the transport path.

FIG. 14 shows the state of face-down paper discharge. The recording paper P turned upward by the flapper 14 is guided along the face-down guide 15, and is discharged to the face-down recording paper discharge tray 12 by the face-down discharge roller pair 10j.

When the user selects face-up discharge, a switching lever (not shown) is used to switch the flapper 14.
And discharges the document to the document discharge tray 8 side.
The tray 8, which also serves as a face-up discharge tray and a document discharge tray, has a wire shape as shown in FIG. 13, and it is said that there is an obstacle on the front of the apparatus even when the user stands in front of the apparatus. Such feelings are alleviated.

The cassette section 13 is provided at the bottom of the apparatus main body 1. Recording paper P loaded on cassette orchestra 31
The intermediate plate 36 is pressed against the separation roller 60 by the upward rotation of the intermediate plate 36 by the lifter arm (pressure contact member) 38, and is separated one by one by the separation pad 73 (friction piece separation method), and along the separation pad holder 74. The sheet is further inverted by a conveying roller 29, a cover-side U-turn guide 28a disposed on the rear cover 28, and a main-unit-side U-turn guide 28b disposed on the apparatus main body 1 side.

Further, the leading end position of the recording paper P being fed is detected by the registration sensor 28c, and the photosensitive drum 1
After the timing of paper feeding and image output is adjusted so that the leading end of the toner image formed on the recording paper P coincides with the leading end of the recording paper P, the recording paper P is conveyed between the transfer charger 10f and the photosensitive drum 10a. The image is recorded on the lower surface side of the recording paper P stacked on the cassette unit 13.

The recording paper P has a width regulating plate 33 and a rear end regulating plate 34 movably mounted in accordance with the recording paper size.
This restricts the side end surface and the rear end surface so that skewing and non-feeding do not occur. The number of sheets that can be loaded on the recording paper is approximately 2
There are 50 sheets, which are configured to be pulled out toward the mounting body 1 in the front direction (front loading method). The stackable recording paper sizes are A4, letter, and legal. In FIG. 14, the rear end regulating plate 34 is set at the position of the letter size.

The manual paper feed unit 11 is provided above the rear cover 28. The recording paper P inserted into the manual paper feed unit 11 is transported by the conveying roller 29 and the U-turn guide 28b.
Is sent to the image forming unit 10 by the rollers 281 provided in the printer.

The apparatus main body 1 is provided with a cartridge cover 2 which can be opened and closed. When the cartridge cover 2 is opened, the recording cartridge 10e can be pulled out and replaced.

In the facsimile apparatus of this embodiment, the cartridge cover 2 is provided with an interlock mechanism, and when the cartridge governor 2 is open or the recording cartridge 10e is not set in the apparatus main body 1, 4 does not work.

A drum exposure prevention shutter (not shown) provided on the recording cartridge 10e is designed to operate in conjunction with the setting of the recording cartridge 10e in the apparatus main body 1. When the cartridge cover 2 is opened, the recording cartridge 10e is opened. While it opens when it is set on the device body 1,
The recording cartridge 10e is closed when the recording cartridge 10e is taken out of the apparatus main body 1, thereby preventing unnecessary exposure of the photosensitive drum 10a.

When a jam occurs during recording, the cartridge cover 2, the rear cover 28, the face down 15 or the cassette unit 13 is opened to open the recording sheet P staying inside the apparatus main body 1. Can be taken out.

The contact type image sensor 7 irradiates the image information surface of the original S with light from an LED array as a light source, and forms reflected light reflected from the image information surface on a sensor element by a self-fox lens (trademark). Then, the image information is read.

FIG. 15 is a block diagram of a control system 300 of a facsimile apparatus using a laser beam printer according to the present invention.

In the figure, a CPU 301 controls the entire facsimile machine. This CPU 301
It is composed of a ROM for storing a control program of the PU and the MPU, a RAM used as a work area for various data processing and a temporary recording section for image information, an image processing section for performing image scaling, resolution conversion, and the like. I have.

The CPU 301 is provided with a calendar and a clock function having a well-known configuration, and an area for storing important system setting information such as one-touch key destination information and software switch information in the RAM is provided by a battery backup. Is protected from accidental obstacles. The control system of the facsimile machine is the CPU 3
01 and the following elements 302 to 310 are connected via an interface.

The operation unit 302 includes various key switches such as a numeric keypad, a function key, a one-touch key, a start key, and a stop key.

The display unit 303 includes an LCD for displaying various messages, various LEDs for displaying a transmission mode and the like.

The reading unit 304 includes a driving unit such as a reading motor,
It comprises a reading sensor for reading an image, an image processing unit for shading and binarizing the read image, various sensors for detecting a document, and the like.

The recording unit 305 includes a driving unit such as a recording motor,
It includes a laser scanner, a recording unit for controlling an electrophotographic process, an image processing unit for smoothing an image to be recorded, and various sensors for detecting recording paper and the like.

The communication control unit 306 that performs outgoing calls, incoming calls, encoding of image data, and the like has a connection unit composed of MODEM, NCU, and the like, and a communication network is connected to the connection unit.

The CPU external interface 309 is
An interface for directly transmitting and receiving data from the U301. For example, by connecting to an external computer via a line such as RS232C, SCSI, LAN, or the like, the device is used as a scanner printer of the external computer.

The HDD 310 is used as a large-capacity nonvolatile memory for storing image information and the like.

Next, the basic operation of the laser beam printer will be described with reference to FIG.

In FIG. 16, reference numeral 400 denotes a semiconductor laser which blinks a laser beam for image data to be recorded;
Is a polygon motor, 402 is a polygon mirror rotated by the polygon motor 401, 403 is an optical system for performing image formation, tilt correction, etc., 404 is a photodetector, 405 is a return mirror, 406 is a photosensitive drum, 407 is a developing device,
P is a recording sheet, 409 is a conveyance guide, and 410 is a fixing device.

In the above configuration, first, the laser beam emitted from the semiconductor laser 400 is
The light is deflected by being reflected by the light 2, and is irradiated onto the photosensitive drum 406 via the optical system 403 and the folding mirror 405 (main scanning). At this time, the head is searched by the photo detector 404, and the irradiation position is determined. While the main scanning is completed for one line, the photosensitive drum 406 rotates by one line (sub-scan).

The image formed on the photosensitive drum 406 as described above is developed by the developing device 407 and is transferred onto the recording sheet P. The recording sheet P is conveyed along a conveyance guide 409, is fixed by a fixing device 410, and is discharged outside the apparatus main body 1.

The photosensitive drum 406 and the developing device 4
07 and the sub-scanning system elements such as the fixing device 410 are synchronously driven by a recording motor, gears, belts and the like (not shown).

Further, in the above embodiment, the image recording section has been described by taking a laser beam printer as an example. However, as long as a cut sheet is used, other electrophotographic, thermal transfer or ink jet sheet feeding may be used. It is also applicable to a feeding device.

Further, the sheet separation method is not limited to the combination of the separation roller 60 and the separation pad 73 according to the above-described embodiment, and another separation method such as a retard roller method may be applied. When the retard roller method is adopted, the roller that comes into contact with the separation roller 60 is provided with a torque limiter so as to follow the separation roller 60 when a paper feeding torque greater than a predetermined value is applied, and in a direction opposite to the sheet feeding direction. A one-way clutch is provided so as to be able to rotate freely. In this case, when the cassette unit 13 is pulled out of the apparatus main body 1, the roller that comes into contact with the separation roller 60 follows the separation roller 60. The same effect as in the embodiment can be obtained.

In addition, the number of feeding units, the types of recording sheets to be used, and the number of stacked sheets are not particularly limited as long as they do not deviate from the configuration of the present invention.

In addition, the sheet feeding apparatus L according to the present invention is capable of not only feeding the recording sheet described above but also an optical system as an image reading means for reading the document sheet, the contact type image sensor 7 and the like. Document feeder that feeds documents to
The present invention can be applied to an image forming apparatus such as an electrophotographic copying machine.

In the above embodiment, the fulcrum shaft 74a is set so as to be on the tangent to the outer periphery of the separation roller passing through the contact portion between the separation roller 60 and the separation pad 73. There is no problem as long as it does not significantly affect the pressure contact force of the steel. Since the fulcrum shaft 74a is slightly set on the separation pad 73 side, the separation pad 73 is slightly indented, and the separation pad 73 is always urged in the same direction as the urging force of the separation spring 72. In addition, it is possible to obtain an effect that vibration is hardly generated.

[0106]

As described above, according to the present invention,
The pivot point of the separating unit is disposed in the vicinity of the tangential direction at the contact point between the separating unit and the feeding unit, and the viscoelastic member is placed on the outer periphery of the pivot point. There is no backlash, vibration due to friction fluctuation can be absorbed, and vibration of the separating means can be prevented, and quiet sheet feeding can be performed.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a main part of a sheet feeding apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating a first example of assembly of a separating unit in the sheet feeding apparatus.
FIG.

FIG. 3 shows a second example of the assembly of the separating means in the sheet feeding apparatus.
FIG.

FIG. 4 is a front view of the sheet feeding device.

FIG. 5 is an explanatory diagram of a power transmission unit of the sheet feeding device.

FIG. 6 is a diagram illustrating a first operation of a cassette sheet feeding unit.

FIG. 7 is a diagram illustrating a second operation of the cassette sheet feeding unit.

FIG. 8 is a diagram illustrating a third operation of the cassette sheet feeding unit.

FIG. 9 is an explanatory diagram of a main part of a cassette sheet feeding unit.

FIG. 10 is a plan view of the cassette unit.

FIG. 11 is a front view showing a cassette part with a part cut away.

FIG. 12 is an operation state diagram of a feeding unit. (A) is a first operation state diagram, (b) is a second operation state diagram, (c) is a third operation state diagram, (d) is a fourth operation state diagram, and (e) is a fifth operation state diagram. (F) is a sixth operation state diagram, (g) is a seventh operation state diagram, and (h) is an eighth operation state diagram.

FIG. 13 is an external perspective view of an example of a facsimile apparatus using the sheet feeding device of the present invention.

FIG. 14 is a sectional view showing a schematic configuration of the facsimile machine.

FIG. 15 is a block diagram of a control system of the facsimile machine.

FIG. 16 is a conceptual diagram illustrating a basic operation of the laser beam printer.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Apparatus main body 10 Image formation part (image formation means) 31 Cassette arrangement (sheet stacking means) 51 Rubber bush 60 Separation roller (feeding means) 70 Front-end protrusion part 71 Separation lever (biasing means) 72 Separation spring (biasing means) 73 Separation pad (separation means) 74 Separation pad holder (separation means) 74a Rotating fulcrum shaft

Claims (11)

[Claims] 1. A sheet stacking means for accommodating a plurality of sheets, a feeding means for feeding sheets out of the sheet stacking means, and arranged so as to be able to approach and separate from the feeding means, and cooperating with the feeding means. A sheet feeding device, comprising: separating means for separating sheets one by one, and separating unit urging means for urging the separating means toward the feeding means side. A sheet feeding device, wherein a pivot shaft of a separating unit is provided on a tangent line of a feeding unit passing through a contact portion with the unit, and a viscoelastic member is externally fitted to the pivot shaft. 2. The separating unit includes a friction member that contacts the feeding unit, and an arm that supports the friction member and is swingable about the pivot shaft. 2. The sheet feeding apparatus according to claim 1, wherein said means urges said friction member toward feeding means. 3. The friction member according to claim 2, wherein the friction member is held by a friction member holder, and the friction member holder is swingably supported on the arm portion in a sheet width direction. Sheet feeding device. 4. A sheet feeding apparatus according to claim 1, wherein said sheet stacking means is detachably supported by an apparatus main body. 5. The sheet feeding device according to claim 2, wherein a guide for guiding the sheet separated by the separating unit along the feeding unit is provided on the arm unit. 6. A sheet stacking means for accommodating a plurality of sheets, a feeding means for feeding a sheet from the sheet stacking means, and arranged so as to be able to approach and separate from the feeding means, and cooperating with the feeding means. A sheet feeding device, comprising: separating means for separating sheets one by one, and separating unit urging means for urging the separating means toward the feeding means side. A sheet feeding means provided with a rotation fulcrum shaft of the separation means on the separation means side of a tangent line of the feeding means passing through a contact portion with the means, and a viscoelastic member fitted on the rotation fulcrum shaft. apparatus. 7. The separating unit includes a friction member that contacts the feeding unit, and an arm that supports the friction member and is swingable about the rotation fulcrum shaft. 7. The sheet feeding apparatus according to claim 6, wherein the means biases the friction member toward a feeding means. 8. The friction member according to claim 7, wherein the friction member is held by a friction member holder, and the friction member holder is supported by the arm portion so as to be swingable in a sheet width direction. Sheet feeding device. 9. The sheet feeding apparatus according to claim 6, wherein said sheet stacking means is detachably supported by an apparatus main body. 10. The sheet feeding device according to claim 7, wherein a guide for guiding the sheet separated by the separating unit along the feeding unit is provided on the arm unit. 11. A sheet feeding apparatus according to claim 1, further comprising: an image forming unit that forms an image on a sheet fed from the sheet feeding apparatus. An image forming apparatus comprising: