JPH1095548A - Sheet separating device and image reading device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To return a distance between rollers to an initial state every document shut successively fed and to surely and separately feed the document sheet by providing a fixed play in a drive transmission path for transmitting a drive force to a first rotating body to make to first rotating body start to rotate with a first of the play. SOLUTION: A pin 7 integrally bound to a shaft 16 is fitted in a recess 10c of a feed roller 10 and a specified play (r) is made in the direction of rotation in a connection between the feed roller 10 and the shaft 16. After the tip of a document sheet is detected by a paper feed sensor and an electromagnetic clutch is disconnected, the feed roller 10 and the carrying roller are rotated together by the sheet. When the rear end of the document sheet is detected by the paper feed sensor, the electromagnetic clutch is operated but the feed roller 10 and the carrying roller are not rotated by the play (r). Therefore, even when the tip of the following document sheet is dragged to a separating part, it is not carried further and a distance between rollers is initialized in the interim because a load is not applied to the feed roller 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet separating apparatus for separating and feeding sheets one by one, and more particularly to a sheet separating apparatus in an electronic file, a facsimile, a copying machine, and the like.

[0002]

2. Description of the Related Art Conventionally, as a sheet separating apparatus in an electronic file, a facsimile, a copying machine, etc., there is a document separating apparatus for separating and feeding originals as stacked sheets one by one. As shown in FIG. 7, the original separating apparatus has large diameter portions 201a and 202a and small diameter portions 201b and 202b, respectively.
So-called comb-shaped rollers 201,
The large diameter portion 201a and the small diameter portion 202 of each roller 201, 202 are
b, the small-diameter portion 201b and the large-diameter portion 202b are disposed so as to face each other, and one roller (hereinafter, referred to as a feed roller) 201 having a large frictional force with respect to the document is moved in the forward direction with respect to the document conveying direction. The other roller having a smaller frictional force with respect to the document than the feed roller 201 (hereinafter, referred to as a blocking roller)
There is known a configuration in which the originals are separated one by one and fed by rotating the original 202 in the reverse direction.

According to this method, the rollers 201, 20
2 is non-contact, and by changing the distance between the shafts of the rollers 201 and 202, the amount of overlap of the comb-shaped rollers 201 and 202 (with respect to the large diameter portion of one of the rollers). Since it is possible to easily adjust the separation force of the original by changing the amount of entry α of the large diameter portion of the other roller, it is convenient when the original is fed at high speed or when durability is required.

However, the comb-shaped rollers 201 and 20 are so arranged that an appropriate separating force can be obtained according to the thickness of the original to be fed.
2, the amount of overlap α must be changed according to the thickness of the original document. If the overlap amount α is inappropriate, there is a problem that poor feeding or double feeding occurs. Particularly, in the past, since the adjustment of the overlap amount α according to the thickness of the document was manually performed, there was a disadvantage that the apparatus could only be handled by a skilled person. Further, when the thicknesses of the originals are different, there is a problem that workability is poor because originals having different thicknesses cannot be sent at once.

Therefore, utilizing the fact that the load acting on the comb-shaped rollers 201 and 202 changes in accordance with the thickness of the original, a differential mechanism such as a planetary gear unit is used so that the load is always constant. A method of variably controlling the distance between the shafts of the comb-shaped rollers 201 and 202 using the same has been proposed (JP-A-8-8).
No. 5641).

[0006]

However, in the above-described conventional example, when the original is continuously fed, the first original is placed between the comb-toothed rollers 201 and 202 after the second original. If the original arrives in a dragged state, especially if the second and subsequent originals are thinner than the first original, the first original will cause the axial distance between the feed roller 201 and the blocking roller 202 (over Since the wrap amount α) is widened, there is a problem that double feeding is likely to occur in feeding the second document.

In order to prevent the double feeding as described above, a feeding roller (not shown) which is provided upstream of the comb-shaped rollers 201 and 202 in the conveying direction and feeds a document between the rollers 201 and 202 is provided. Each time the original is fed, the distance between the feed roller 201 and the blocking roller 202 is returned to the initial state, and then the next original is fed. Required.

However, if the feeding roller is separated from the document for each sheet, there is a disadvantage that the response speed cannot be met when the document is fed at a high speed, and even if this disadvantage is solved, a mechanism for that purpose is required. However, there is a problem that the cost is increased and noise is increased.

[0009] Therefore, an object of the present invention is to provide a method for a continuously fed original, even when the original is fed at a high speed.
An object of the present invention is to return the center distance between the feed roller and the blocking roller to the initial state for each document by a simple method so that separation and feeding can be reliably performed.

[0010]

In order to achieve the above object, a typical configuration of the present invention comprises a first rotating body and a second rotating body having a large diameter portion and a small diameter portion alternately in the axial direction. The diameter part and the small diameter part, the small diameter part and the large diameter part are arranged so as to face each other, and the first rotating body having a large frictional force with respect to the sheet is rotated in the forward direction with respect to the conveying direction, compared with the first rotating body. By rotating the second rotating body having a small frictional force against the sheet in a direction opposite to the conveying direction, the sheet separating apparatus separates and feeds the sheets one by one. The distance between the axes of the first rotating body and the second rotating body is configured to be variable by an acting load, and a certain play is provided in a drive transmission path for transmitting a driving force to the first rotating body, The first rotating body is configured to start rotating with a delay for play. It is characterized in.

According to the above configuration, a certain play is provided between the drive transmission paths for transmitting the driving force to the first rotating body, and the start of rotation of the first rotating body is delayed by the play. In the meantime, by returning the distance between the axes of the first rotating body and the second rotating body to the initial state, even if the sheet is fed at a high speed, the separation of the continuously fed sheet is ensured. It is possible to do.

[0012]

Next, an embodiment of a sheet separating apparatus to which the present invention is applied will be specifically described with reference to the drawings. In the following embodiments, a sheet separating device in an image reading device is exemplified.

[First Embodiment] An image reading apparatus provided with a sheet separating apparatus according to a first embodiment will be described with reference to the drawings. FIG. 1 is a schematic sectional view showing a schematic configuration of the present image reading apparatus.

In the order of the following description, first, the schematic configuration of the entire image reading apparatus will be described, and then the configuration and operation of the sheet separating apparatus according to the present invention will be described.

First, a schematic configuration of the image reading apparatus will be described. The image reading apparatus has a function of separating and feeding the originals G as stacked sheets one by one, reading images on the front and back surfaces of the originals G, displaying the images on a display, and simultaneously storing the images in a storage device. Further, it has a function of retrieving an image recorded in the storage device and displaying it on a display.

As shown in FIG. 1, a document G set on a tray 1 and a document table 2 is fed into the apparatus by a feeding roller 4. And among the comb tooth-shaped rollers 10 and 58 having the large diameter portion and the small diameter portion alternately in the axial direction, and the large diameter portion and the small diameter portion, and the small diameter portion and the large diameter portion are arranged so as to face each other, A comb-shaped roller (hereinafter, referred to as a feed roller) 10 as one rotating body is rotated in a forward direction with respect to a conveying direction, and a comb-shaped roller (hereinafter, referred to as a blocking roller) 58 as a second rotating body.
Are rotated in the reverse direction to separate and feed the originals G sent by the feed roller 4 one by one.

Further, the original G is a pair of registration rollers 38,
The sheet is conveyed in a timely manner by 68, and is conveyed while being nipped by a pair of conveying rollers 90 and 91 and a pair of conveying rollers 92 and 93 rotating at a constant speed. At this time, the conveying roller pair 90, 91
The front and back surfaces of the original G are illuminated by the light sources 94 and 98 through the transparent portions 88a and 89a provided on the guide plates 88 and 89, respectively. Then, the reflected light (image light) is imaged on image reading sensors 97 and 101 such as CCDs by plane mirrors 95 and 99 and imaging lenses 96 and 100,
The images on the front and back sides of the document G are read.

The read document images are sequentially displayed on the display device 105 and simultaneously stored in the storage device 106 such as a magneto-optical disk. Further, the image information of the document G stored in the storage device 106 such as a magneto-optical disk can be appropriately retrieved and displayed on the display device 105.

On the other hand, the original G from which the image has been read is nipped and conveyed by conveying belts 102 and 103 and discharged to a discharge section 104.

In the figure, reference numeral 107 denotes an electrical unit having a power supply, a control board, and the like for causing the apparatus to perform the above-described operations.

Next, the configuration around the sheet separating apparatus according to the present invention will be described in detail. FIG. 2 is a sectional view showing a schematic configuration around the sheet separating apparatus according to the present invention, FIG. 3 is a plan view thereof, and FIG. 4 is a sectional view taken along line AA in FIG.

In FIG. 1, reference numeral 1 denotes a tray on which a document G is placed, 2 denotes a document table mounted rotatably about a shaft 2a, and 3 denotes a document table which rotates about a shaft 3a and raises the document table 2 upward. Push-up lever.

Reference numeral 4 denotes a feeding roller, and the side portions 6a, 6b
Is rotatably attached to a U-shaped member 6 having

Reference numeral 50 denotes a stopper, which restricts the feeding roller 4 from lowering by a certain amount by contacting the projection 6c of the U-shaped member 6.

Reference numeral 9 denotes a document detection sensor, which detects the presence or absence of the document G by a sensor lever 8 that rotates about a shaft 8a. Based on the signal from the document detection sensor 9, the upper surface of the document G is controlled to be always at a fixed position.

Reference numeral 10 denotes a feed roller as a first rotating body having a large diameter portion 10a and a small diameter portion 10b alternately in the axial direction. A fan-shaped concave portion 10c is provided on one end face in the rotation direction. A pin 7 integrally connected to a shaft 16 rotatably mounted on the side surfaces 15a and 15b of the U-shaped member 15 is fitted into the concave portion 10c of the feed roller 10. Therefore, a fixed play r is provided in the connecting direction between the feed roller 10 and the shaft 16, as shown in FIG.

A gear 13 is integrally provided on the other end face of the feed roller 10 and is connected to the feed roller 4 via gears 12 and 11.

The U-shaped member 15 is a shaft of a registration roller 38.
38a rotatably mounted, spring (not shown)
2 urges the shaft 38a in the counterclockwise direction in FIG.

The shaft 38a of the registration roller 38 is connected to a side plate 44,
It is rotatably supported by 45 and has an electromagnetic clutch 42 at one end.
Is attached. Accordingly, the coupling operation of the drive input to the registration roller 38 from the gear 42a is controlled by the electromagnetic clutch 42. Further, the registration roller
A gear 21 having teeth 21a and 21b is rotatably attached to a shaft 38a of the 38. The cylindrical portion 21c of the gear 21
A gear 22 having teeth 22a and 22b is rotatably mounted on the gear.

Reference numeral 58 denotes a blocking roller as a second rotating body having a large diameter portion 58a and a small diameter portion 58b alternately in the axial direction.
It is integrally attached to a shaft 59 rotatably supported by 61 and 62. And, as described above, the feed roller
The large diameter portion 10a and the small diameter portion 58b and the small diameter portion 10b and the large diameter portion 58a are arranged so that the large diameter portion 10a and the small diameter portion 58b face each other.

Reference numeral 60 denotes a U-shaped member having side portions 60a and 60b, and a shaft rotatably supported by the side plates 61 and 62.
It is rotatably attached to 59. This U-shaped member 60
A registration roller 68 is rotatably mounted on the registration roller 68, and the registration roller 68 is
Pressing against 38.

The blocking roller 58 is connected to the registration roller 68 by gears 63, 64, 65, 66.
Rotates counterclockwise in FIG. 2 in correspondence with the rotation of the pair of registration rollers 38, 68.

In the drawing, 70 and 71 are paper feed sensors for detecting the position of the original, and 72 and 73 are guide plates for guiding and supporting the original conveyed by rollers and the like.

Reference numeral 30 denotes a planetary gear unit, which is constituted by a sun gear 33, an internal gear 34, and a carrier 31. A planet gear 32 is rotatably mounted on a shaft 31a implanted in the carrier 31 (see FIG. 5).

The sun gear 33 is integrally attached to a shaft 37 rotatably supported by the side plates 44 and 46. Similarly, the internal gear 34 is rotatably mounted on a shaft 37 and has a gear 34
a is provided. Similarly, a carrier 31 having a planetary gear 32 is rotatably mounted on a shaft 37, and a gear 31b is integrally provided.

A gear 34 provided on the outer periphery of the internal gear 34
a is connected to the gear 18 via gears 23, 22, and 20. The gear 18 is mounted on a shaft 16 of the feed roller 10 via a one-way clutch 17.

On the other hand, the gear 31 provided on the carrier 31
b is connected to the gear 56 via the gear 25. This gear
Reference numeral 56 is integrally attached to one end of a separation adjustment shaft 49 rotatably attached to the side plates 46 and 47 as shown in FIG. The other end of the separation adjusting shaft 49 is provided with a screw portion 49a, and the screw portion 49a has an inclined member 48a having an inclined portion 48a.
48 are fitted.

A groove 48b is provided in the inclined member 48, and a cut-and-raised portion 47a of the side plate 47 is fitted in the groove 48b.
Therefore, the rotation of the separation adjustment shaft 49 allows the inclined member 48 to slide only in the axial direction. Further, the inclined member
A hemispherical portion 39a of a regulating member 39 integrally attached to the U-shaped member 15 is in contact with the inclined portion 48a of the 48, and regulates the position of the U-shaped member 15.

A shaft 37 on which the planetary gear set 30 is mounted
A gear 35 whose movement is restricted in the axial direction is rotatably mounted on the, and a pressing member 28 which is movable only in the axial direction is integrally mounted. The pressing member 28 presses the side surface of the gear 35 via the friction plate 27 by the spring 29. In the figure, reference numeral 36 denotes a stopper for applying a pressing force to the spring 29.

A friction mechanism 41 is formed by the friction plate 27, the pressing member 28, the spring 29, and the stopper 36.
Is formed.

An electromagnetic clutch 40 is attached to the shaft 37, and the connection operation of the drive input from the gear 40a of the electromagnetic clutch 40 is controlled.

Further, the gear 35 is connected to the gear 18 via gears 26, 24, 21, and 19. The gear 18 is attached to the shaft 16 of the feed roller 10 via the one-way clutch 17 as described above.

The number of rotations transmitted from the shaft 37 to the feed roller 10 is smaller when transmitted from the gear 35 via the gear 18 than when transmitted from the gear 34a via the gear 18. The rotation speed is set to be large.

Further, the drive transmission force by the friction mechanism 41 is converted on the shaft 16 of the feed roller 10, and is approximately equal to the load torque acting on the feed roller 10 when the proper separation is performed at the time of document feeding. They are set to the same size.

Next, the operation of the device configured as described above will be described in detail. First, when a switch (not shown) is pressed to start a recording operation, the push-up lever 3 is moved to the shaft 3a.
And the document table 2 is rotated counterclockwise. Then, the uppermost surface of the document G on the document table 2 is
Feed roller 4 located at the lowest point regulated by stopper 50
Then, after contacting the sensor lever 8, the rotation of the push-up lever 3 stops when the document detection sensor 9 detects the other end of the sensor lever 8.

Next, the electromagnetic clutch 40 is operated, whereby the gear 40a and the shaft 37 are connected, and the sun gear of the planetary gear set 30 is
The gear 35 rotates clockwise in FIG. 5 via the friction mechanism 33 and the friction mechanism 41.

At this time, the original G is a feed roller serving as a separation unit.
Since the paper is not fed between the feed roller 10 and the blocking roller 58, no load acts on the feed roller 10. Therefore, the drive via the friction mechanism 41 is transmitted to the feed roller 10 without slipping, and the feed roller 10 rotates counterclockwise in FIG.

At this time, since the rotation speed directly transmitted from the gear 35 is higher than the rotation speed transmitted from the sun gear 33 of the planetary gear device 30, the rotation of the internal gear 34 while the carrier 31 is stopped is performed. The internal gear 34 rotates faster. And
This rotation difference causes the carrier 31 to rotate in the direction of arrow C in FIG. 5 and rotate the separation adjustment shaft 49 in the direction of arrow E.

As a result, the tilting member 48 moves leftward in FIG. 4 and the regulating member abutting on the tilting portion 48a.
39 moves down. That is, the U-shaped member 15 is rotated counterclockwise in FIG. 2 to reduce the distance between the feed roller 10 and the blocking roller 58.

When the inclined member 48 moves to the left in FIG. 4 and the end surface of the inclined member 48 abuts against the side plate 47, there is no force to rotate the separation adjusting shaft 49 by the frictional force of the friction mechanism 41. The rotation of the separation adjustment shaft 49 stops.

At this time, the center distance between the feed roller 10 and the blocking roller 58 is minimized. That is, the center distance between the feed roller 10 and the blocking roller 58 returns to the initial state. This position (minimum axial distance) is determined in accordance with the thinnest document supplied to the apparatus. If the position of the inclined member 48 abutting on the side plate 47 can be adjusted, the inclined member 48 can be adjusted. An optimum position for minimizing the time required for movement can be determined according to the thickness of the document.

The original G sent to the separation unit by the feed roller 4 is prevented from being supplied with the second and subsequent originals by the blocking roller 58, and the uppermost surface of the original G stacked on the original One sheet is fed between the feed roller 10 and the blocking roller 58.

At this time, since the feed roller 10 tries to feed the original G against the blocking roller 58, a load corresponding to the thickness of the original G acts on the feed roller 10. If this load is larger than the value set by the friction mechanism 41, slippage occurs in the friction mechanism 41 and the feed roller
10 rpm drops.

Then, the rotation of the internal gear 34 of the planetary gear device 30 becomes slow, and the internal gear in a state where the carrier 31 is stopped.
The carrier 31 rotates in the direction of arrow B in FIG.

As a result, the separation adjusting shaft 49 rotates in the direction of arrow D in FIG. 5, and moves the inclined member 48 rightward in FIG. Then, the regulating member 39 in contact with the inclined portion 48a is moved upward. That is, the U-shaped member 15 is
At a clockwise direction to increase the center distance between the feed roller 10 and the blocking roller 58. As a result, the overlap amount α (see FIG. 4) between the feed roller 10 and the blocking roller 58 is reduced.

The load acting on the feed roller 10 decreases as the overlap amount α decreases. Correspondingly, the sliding amount of the friction mechanism 41 decreases, and the rotation of the feed roller 10 increases. When the rotation speed of the feed roller 10 matches the rotation speed of the feed roller 10 when the carrier 31 is stopped, the carrier 31
Rotation stops.

Then, the feed roller 10 and the feed roller 4
Is driven by the frictional force of the friction mechanism 41, and FIG.
, The document G is conveyed toward the pair of registration rollers 38, 68. Feed roller at this time
The rotation speed of 10 is the rotation speed of the feed roller 10 when the carrier 31 is stopped. Therefore, the friction mechanism 41 has slipped.

The electromagnetic clutch 40 is disengaged when the leading end of the document G sent by the feed roller 10 abuts the nip portion of the pair of registration rollers 38 and 68 after a certain period of time has passed since the feed sensor 70 detected it. Then, the rotation of the feed roller 10 temporarily stops, and the original G stops.

Then, at an appropriate timing, the electromagnetic clutch 42 and the electromagnetic clutch 40 are operated again, and the original G is fed by the feed roller 4, the feed roller 10, and the registration roller pair 38,
It is transported sandwiched between 38.

Then, the leading end of the document G is fed to the paper feed sensor 71.
, The electromagnetic clutch 40 is disengaged again, and the document G is sandwiched between the pair of registration rollers 38 and 68 and sent to the next step. Then, a series of processing operations such as reading as described above are performed.

On the other hand, after the electromagnetic clutch 40 is disengaged, the feed roller 10 and the feed roller 4 are rotated by the document G, and the positional relationship between the shaft 16 of the feed roller 10 and the connecting portion between the feed roller 10, ie, the shaft The positional relationship between the pin 7 provided on the feed roller 16 and the fan-shaped concave portion 10c provided on the feed roller 10 is shown in FIG. 6 (a) where the feed roller 10 is driven by the shaft 16 and rotated. The state shown in FIG.

Since the driving force due to the above-mentioned rotation is not transmitted to the drive transmission path after the gear 18 by the action of the one-way clutch 17, only the feed roller 10 and the feed roller 4 rotate.

The rear end of the original G is fed to the paper feed sensor 70.
, The electromagnetic clutch 40 operates again at an appropriate timing. At this time, the shaft 16 of the feed roller 10
Rotates until the pin 7 provided on the shaft 16 reaches the position shown in FIG. 6B from the position shown in FIG. 6B, that is, the feed roller 10 and the feed roller 10 Does not rotate.

Therefore, even if the leading end of the next original G is dragged by the first original G and reaches the separation section, the original G is not further fed. Also during this time,
Since the load of the document G does not act on the feed roller 10, the center distance between the feed roller 10 and the blocking roller 58 returns to the initial state where the distance becomes minimum as described above.

After the pin 7 of the shaft 16 of the feed roller 10 reaches the position shown in FIG. 6A, the feed roller 10 and the feed roller 4 start rotating, and the original G is fed to the feed roller 10 and the blocking roller. Convey between 58. That is, the feed roller 10, and the feed roller 4 that rotates in conjunction with the feed roller 10,
After the electromagnetic clutch 40 is operated, it starts rotating with a delay of play r shown in FIG. And as described above, the feed roller
The center distance between the feed roller 10 and the blocking roller 58 is adjusted according to the load acting on the document 10, and the document G is fed into the apparatus.

The play r provided between the shaft 16 of the feed roller 10 and the feed roller 10 is determined by the thickness of the original G to be fed. That is, it is sufficient if there is a play that can be moved from the set separation adjustment position when the thickest document G is fed to the separation adjustment position when the thinnest document G is fed. More specifically, the play r may be such that the distance between the axes of the feed roller 10 and the blocking roller 58 can be reliably returned from the set maximum position to the initial state of the minimum position.

In the above-described embodiment, the feeding roller 4
Is linked to the feed roller 10, but the feed roller
The conveying force of the feed roller 4 may be smaller than the conveying force of the document G. For example, if the thickness of the document G is about 0.05 mm to 0.20 mm, the feed roller 10 Even if the feed roller 4 is rotating while the play is stopped for the amount of play and the separation adjustment position returns to the initial state, the document G is prevented from being fed earlier than the separation portion due to the conveyance force. Can be. Therefore, it is not always necessary to link the feed roller 4 with the feed roller 10.

As described above, a certain play r is provided between the drive transmission paths for transmitting the driving force to the feed roller 10, and the start of rotation of the feed roller 10 is delayed by the play r. In the meantime, the distance between the axes of the feed roller 10 and the blocking roller 58 can be returned to the initial state, and even if the document is fed at a high speed, the continuously fed document G can be reliably separated one by one. Can be fed. Specifically, even when the first original G is thick and the next original G is thin, double feeding is not performed, and separation and feeding can be performed reliably.

Further, since there is no need to move the feed roller 4 upstream of the feed roller 10 and the blocking roller 58 in the direction of conveyance with respect to the document G, the mechanism is simple and high-speed continuous feeding is possible. It is also advantageous for the case.

[Other Embodiments] In the above-described embodiment,
Although an image reading apparatus capable of reading images on the front and back surfaces of a document has been illustrated, the present invention is not limited to this. For example, an image reading apparatus capable of reading an image on one side of a document is also effective.

Further, in the above-described embodiment, the image reading apparatus configured to read the image of the conveyed document by the reading means fixed at a predetermined position is exemplified. However, the present invention is not limited to this. For example, the present invention is also effective in an image reading apparatus that separates and feeds originals one by one and stops at a predetermined position on a platen glass or the like, and then scans the reading unit to read an image of the original.

In the above-described embodiment, as an example of the sheet separating apparatus to which the present invention is applied, an example in which the present invention is applied to a document separating unit that separates and feeds a document one by one in an image reading apparatus has been described. It is not limited to this,
For example, the present invention is applied to a document separating unit that separates and feeds documents one by one in another device such as a facsimile or a copying machine, or a recording sheet separating unit that separates and feeds recording sheets one by one. Has the same effect.

[0073]

As described above, according to the present invention, a certain play is provided in the drive transmission path for transmitting the driving force to the first rotating body, and the first rotating body starts rotating by this play. In the meantime, the distance between the axes of the first rotating body and the second rotating body (adjustment position for separation) can be returned to the initial state for each sheet, and sheets having different thicknesses can be continuously , It can be reliably separated and fed.

Further, since there is no need to bring a rotating body provided upstream of the first rotating body and the second rotating body in the transport direction from the first rotating body and the second rotating body into and out of each sheet as in the related art, the mechanism can be simplified. And cost reduction. Further, noise due to the contact and separation of the rotating body can be eliminated.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view illustrating a schematic configuration of an image reading apparatus including a sheet separating apparatus to which the present invention is applied.

FIG. 2 is a schematic sectional view showing the sheet separating device.

FIG. 3 is a plan view showing a drive transmission path of the sheet separating device.

FIG. 4 is a sectional view taken along line AA of FIG. 2;

FIG. 5 is a drive explanatory diagram of the planetary gear device.

FIG. 6 is an explanatory view showing a shaft of a feed roller, and the feed roller and a drive connecting portion.

FIG. 7 is an explanatory view showing a mounting positional relationship between a conventional feed roller and a blocking roller.

[Explanation of symbols]

 G: Document 1: Tray 2: Document mounting table 2a, 3a: Shaft 3: Push-up lever 4: Feed roller 6, 15, 60: U-shaped member 6a, 6b, 15a, 15b, 60a, 60b: Side surface 6c ... Protrusion 7 ... Pin 8 ... Sensor lever 8a ... Shaft 9 ... Document detection sensor 10 ... Feed roller 10a ... Large diameter part 10b ... Small diameter part 10c ... Recession 11,12,13 ... Gear 16 ... Shaft 17 ... One-way clutch 18, 19, 20, 21 ... gears 21a, 21b, 22a, 22b ... teeth 21c ... cylindrical portions 22, 23, 24, 25, 26 ... gears 27 ... friction plates 28 ... pressing members 29 ... springs 30 ... planetary gear devices 31 ... carriers 31a ... shaft 31b ... gear 32 ... planetary gear 33 ... sun gear 34 ... internal gear 34a ... gear 35 ... gear 36 ... stopper 37 ... shaft 38 ... registration roller 38a ... shaft 39 ... regulating member 39a ... hemispherical part 40 ... electromagnetic clutch 40a ... gear 41 ... friction mechanism 42 ... electromagnetic clutch 42a ... gears 44, 45, 46, 47 ... side plate 47a: Cut-and-raised portion 48 ... Inclined member 48a ... Inclined portion 48b ... Groove 49 ... Separation adjustment shaft 49a ... Screw portion 50 ... Stopper 56 ... Gear 58 ... Blocking roller 58a ... Large diameter portion 58b ... Small diameter portion 59 ... Shafts 61, 62 ... Side plates 63,64,65,66 ... Gear 68 ... Registration rollers 69 ... Springs 70,71 ... Feed sensors 72,73,88,89 ... Guide plates 88a, 89a ... Transparent parts 90,91,92,93 ... Conveyance Rollers 94 and 98 Light sources 95 and 99 Planar mirrors 96 and 100 Imaging lenses 97 and 101 Image reading sensors 102 and 103 Transport belt 104 Discharge unit 105 Display device 106 Storage device 107 Electrical unit

Claims (5)

[Claims] 1. A first rotating body and a second rotating body having a large diameter portion and a small diameter portion alternately in the axial direction are arranged so that the large diameter portion and the small diameter portion, and the small diameter portion and the large diameter portion face each other. The first rotating body having a large frictional force with respect to the sheet is rotated in the forward direction with respect to the conveying direction, and the second rotating body having a small frictional force with respect to the sheet is rotated in the direction opposite to the conveying direction with respect to the first rotating body. In the sheet separating apparatus that separates and feeds the sheets one by one, the distance between the axes of the first rotating body and the second rotating body is variable by a load acting on the first rotating body during sheet feeding. And a predetermined play is provided in a drive transmission path for transmitting a driving force to the first rotating body, and the first rotating body is configured to start rotating with a delay corresponding to the play. A sheet separation device characterized by the above-mentioned. 2. The sheet separating apparatus according to claim 1, wherein the play in the drive transmission path is provided at a connecting portion between the first rotating body and a shaft of the first rotating body. . 3. The play provided in the connecting portion is provided in a recess formed in one end face of the first rotating body in a fan shape in a rotating direction, and in a shaft rotatably supporting the first rotating body. 3. The sheet separating apparatus according to claim 2, wherein the sheet separating device is formed by a pin which is engaged with the fan-shaped concave portion by rotation of a shaft until the first rotating body starts rotating. 4. 4. A rotator provided upstream of a pair of rotators composed of the first rotator and the second rotator in the transport direction so as to be driven in conjunction with the first rotator. The sheet separating apparatus according to claim 1, wherein the sheet separating apparatus is configured. 5. An image reading apparatus having reading means for reading an image of a document, wherein the document separating means for separating and feeding the documents one by one is provided. An image reading apparatus comprising the sheet separating apparatus according to (1).