JP3289791B2 - Document feeder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a document feeder which is applied to a document reading apparatus such as a facsimile apparatus and an image scanner, and separates and conveys a plurality of stacked documents one by one and feeds them to a document reading position.

[0002]

2. Description of the Related Art FIG. 7 is a schematic structural view of a conventional facsimile apparatus, wherein 1 is an apparatus main body, 2 is an original mounting table provided on the apparatus main body 1, and an operation table 4 on which an original 3 is loaded. It is an operation board provided with
At the lower part of the operation board 4, an extension of the document table 2, a pickup roller 5, a pressure plate 6 opposed to the pickup roller 5, a document separation / conveyance unit 9 including a separation roller 7 and a feed roller 8, Document reading section
A document transport unit 13 including a transport roller 11 for transporting the document 3 to the document reading unit 10 at a predetermined speed, and a paper discharge roller 12 for transporting the document 3 after the reading is completed is provided.

A light source 15 for illuminating the original surface, a reflecting mirror 17 for deflecting reflected light from the original in the direction of a CCD (Charge Coupled Device) 16, and an image formed in front of the CCD 16 are provided below the original conveying section 13. An original reading optical system 19 including a lens 18 and the like is provided.

A roll-shaped thermosensitive recording paper 20, a thermal head 21, a platen roller
A recording unit 25 including a recording paper cutter 22, a recording paper discharge roller 24, and the like is provided.

In the facsimile apparatus, at the time of reception, printing is performed in a known manner on the thermal recording paper 20 between the thermal head 21 and the platen roller 22 based on the received data, and the thermal recording paper 20 after printing is printed. The paper is cut to a predetermined length by the cutter 23 and discharged to the outside by the recording paper discharge roller 24.

At the time of transmission, the original 3 is placed on the original placing table 2 and is sent between the pressure plate 6 and the pickup roller 5.
When the transmission operation is started, the pickup roller 5 feeds the document 3 to the document separation / conveyance unit 9 from the lowest sheet of the loaded document 3. In the document separating / conveying section 9, when the document 3 is double fed from the pickup roller 5, the separation roller 7 and the feed roller 8
Then, the originals are separated one by one and sent to the transport roller 11.

The original 3 is transported by a transport roller 11 and a discharge roller.
While being conveyed by the document 12, the document reading unit 10 illuminates the image with a light source 15 to perform known optical image reading and image data output by a CCD 16 or the like.

[0008]

In the document feeder 13 of the conventional facsimile apparatus, the pickup roller 5 for pre-feeding the document and the document feeder 13 are divided into functionally large sections. A document separating / conveying unit 9 for separating and conveying the originals one by one, and a conveying roller 11 for conveying the original to the original reading unit 10 at a predetermined speed are required, and the structure is made up of rollers, rollers and their related parts constituting each unit. Has become complicated, and the installation space for them has been required, which has been one of the causes of high cost and large size of the entire apparatus.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a document feeder whose configuration can be simplified, cost reduction and size reduction are possible.

[0010]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a pickup roller for sequentially feeding originals in contact with a plurality of stacked originals, and rotating by receiving a driving force.
A feed roller and a pair that rotates while contacting the feed roller
Consists of a counter roller, in RuHara draft conveying apparatus to transport at a predetermined speed the document on the document reading unit receives the document fed,
The form feed roller and at least the surface of said opposed rollers of a material respectively substantially the same characteristic, by the feed roller and the counter roller, the separable conveyed to one sheet multi-fed document, the opposed roller, With opposing rollers
Work together and give a driving force to the pickup roller
Transmission means for the feed roller,
Only the rotational force obtained by the opposing roller when pressed against
A rotary drive of the transmission means with respect to the pickup roller
It is characterized by power .

[0011]

[0012]

[0013]

[0014]

According to the above means, since the contact surface of the feed roller and the opposed roller constituting the transport roller for transporting the original at a predetermined speed is the same material, the opposed roller is rotated when the feed roller is driven to rotate. When one document enters between the feed roller and the opposing roller, the document is transported to the document reading unit as it is. When multiple documents are fed, the feed roller transports only the lowest document to the document reading unit. Will be
Both rollers Ri Do to also serve as a document separating conveying means, further
When the opposing roller is rotated, the pick-up
Rotational driving force is applied to the
Is it a feed roller when it is pressed against the feed roller and rotates with it?
The transmission means is rotated only by the rotational force to the opposing rollers.
Moving, so the rotation mechanism of the pickup roller is simple
Between the pickup roller and the transport roller.
That transport timing of the document is that, well.

[0015]

[0016]

[0017]

[0018]

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

FIG. 1 is a block diagram showing a front view of a main part according to an embodiment of the present invention, and FIG. 2 is a block diagram showing a plan view of a main part of FIG. A pickup roller 30 is provided above the table 2, and a vertically movable shutter 31 for blocking the document path, a feed roller 32, and a counter roller 33 are provided at an extension of the document table 2, which is a document path. Transport rollers 34 are provided.

A rotational driving force from a motor 35 is applied to the feed roller 32 by a motor gear 36, an idler gear 37, and a roller gear.
Communicate through 38. In addition, the opposing roller 33 is
Receiving the urging force of the pressure leaf spring 40 elastically contacting the
It is in pressure contact on the upper side. Further, a drive gear 43 which is a transmission means connected to a driven gear 41 provided on the pickup roller 30 via a belt 42 is provided on the rotation shaft 39 of the opposing roller 33.

At least the surfaces of the feed roller 32 and the opposing roller 33 are formed of a rubber material or a material having substantially the same characteristics as each other. Reference numeral 44 in FIG. 2 denotes a spring clutch provided on the rotating shaft 45 of the pickup roller 30.

The present embodiment is a so-called upside-down transport apparatus. In this upside-down mode, the stacked originals are transported from the uppermost one.

That is, the original 3 placed on the original placing table 2 is set at a predetermined position with its leading end abutting on the shutter 31. In this state, the transport operation is started, and the motor 35 starts rotating. The rotational driving force of the motor 35 is transmitted to the feed roller 32 via the motor gear 36, the idler gear 37, and the roller gear 38, and rotates the feed roller 32. Since the surface of the opposing roller 33 is made of the same material as the feed roller 32,
When the feed roller 32 rotates, it rotates.

When the opposing roller 33 rotates, the rotational force is transmitted from the driving gear 43 of the opposing roller 33 to the driven gear 41 of the pickup roller 30 via the belt 42, and
To rotate. Before the rotation of this pickup roller 30,
The shutter 31 is moved upward by appropriate means.

When the pickup roller 30 rotates, the original 3 is sent to the nip portion of the transport roller 34. When the original is multi-fed, the original is separated and transported by the transport roller 34, so that only one original is shown in FIG. The document is conveyed to the document reading unit 10 at a predetermined speed.

FIG. 3 is an explanatory diagram for explaining the relationship between the forces at the transport roller 34, and shows a state in which two documents 3 have entered the nip between the feed roller 32 and the opposing roller 33. Here, the document blocking force Ta for blocking the transport of the upper document among the two documents 3 is set such that the equation (Equation 1) holds.

[0027]

[Number 1] Ta _{Here> F C -R D + R B} ,

[0028]

## EQU2 ## F _C = μ _R × P _B R _D = (X−2) × m × μ _P R _B = (X−1) × m × μ _P , where m is the mass of one document and μ _P is the coefficient of friction between the document number of the document X is being set, P _B is facing roller 33
Pressure.

When the expression (Equation 1) is satisfied, the upper document of the two documents 3 can be separated. Therefore,
The frictional force that satisfies the expression (Equation 1) is generated between the rotation support shaft 39 of the opposing roller 33 and the pressing leaf spring 40.

FIG. 4 is a perspective view showing one example of a structure for generating the frictional force.
Is formed, a sliding member 53 having a receiving hole 52 formed in the rotation shaft 39 of the opposing roller 33 to be fitted with the projection 50, and a compression spring 54 provided on the sliding member 53. A friction plate 55 that is pressed against by receiving an elastic force, a notch portion 55a is formed in a part of the friction plate 55, and the notch portion 55a is a rotation stopper member provided on an appropriate member in the apparatus main body. Lock with 56,
By stopping the rotation of the friction plate 55, the frictional force is obtained.

FIG. 5 is a perspective view showing another example of a structure for generating the above-mentioned frictional force. A frictional material 60 having a large coefficient of friction is provided on a pressing leaf spring 40 elastically contacting the rotation support shaft 39 of the opposing roller 33. The installation part of the member 60 is elastically contacted with the rotating shaft 39.

In FIG. 3, the friction force is set so that when one document enters the nip width between the feed roller 32 and the opposing roller 33, the document 3 can be conveyed by losing the conveying force of the document 3. It is necessary to put. That is, when there is one document, the document cannot be conveyed unless the opposing roller 33 rotates. Therefore, it is necessary to satisfy the equation (Equation 3).

[0033]

Equation 3] where _{F C -R D + R B <} Ta <F B -R B,

[0034]

F _B = μ _r × P _B , where μ _r is the coefficient of friction between the surface of the opposing roller 33 and the document.

The opposing roller 33 is pressed against the feed roller 32 and receives no rotational driving force unless the feed roller 32 is rotating. Therefore, when two originals enter the nip portion, the opposing roller 33 is pressed. 33 will not rotate. Therefore,
The pickup roller 30 connected to the opposing roller 33 via the belt 42 also does not rotate.

When the pickup roller 30 rotates while the opposing roller 33 is stopped, as shown in FIG.
As a result, the leading end is locked by the opposing roller 33, so that the swelling occurs between the opposing roller 33 and the pickup roller 30 and a jam occurs, but as described above, when the opposing roller 33 is stopped. The jamming can be prevented by stopping the pickup roller 30.

The material of the opposing roller 33 and the feed roller 32 is the same, or the material of the opposing roller 33 has a slightly lower coefficient of friction. As a result, even if a state in which the opposing roller 33 does not rotate together occurs when one document is conveyed while being sandwiched between the feed roller 32 and the opposing roller 33, the feed roller 32 If the coefficient of friction is larger, the original can be sent without jam.

In the above-described embodiment, the so-called upward-moving transport device has been described as an example. However, the so-called downward-moving transport device in which the pickup roller 30 is installed below the original placing table 2 and transported from the lowermost original. The present invention can also be implemented in

[0039]

As described above, according to the first aspect of the present invention, the feed roller and the opposing roller for conveying the original to the original reading section at a predetermined speed are provided.
Will also comprise a document separating function for separating and conveying the document one by one, Hakare be simplified configuration This will allow for some cost and size reduction, also the rotational force of the opposing roller feed roller
Receiving and rotating pickup roller via transmission means
Because it can be a rotary drive of the pickup roller
The structure can be simplified and the pickup roller
Ru can satisfactorily document conveying timing between the conveying roller and the.

[0040]

[0041]

[0042]

[Brief description of the drawings]

FIG. 1 is a configuration diagram illustrating a front view of a main part in an embodiment of a document feeder according to the present invention.

FIG. 2 is a configuration diagram illustrating a planar state of a main part of FIG. 1;

FIG. 3 is an explanatory diagram of a relationship between forces at a transport roller portion.

FIG. 4 is a perspective view showing an example of a frictional force generating structure.

FIG. 5 is a perspective view showing another example of a structure for generating a frictional force.

FIG. 6 is an explanatory diagram illustrating a document conveyance state.

FIG. 7 is a schematic configuration diagram of a conventional facsimile machine.

[Explanation of symbols]

2… Document loading table, 3… Document, 10… Document reading section, 30
... pickup roller, 31 ... shutter, 32 ... feed roller, 33 ... opposed roller, 34 ... transport roller, 35 ... motor, 40 ... pressurizing leaf spring, 41 ... driven gear, 42 ... belt, 43 ... drive gear (transmission means) .

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ identification code FI H04N 1/00 108 H04N 1/00 108B (58) Field surveyed (Int.Cl. ⁷ , DB name) B65H 3/06 350 B65H 3/52 330 H04N 1/00 108

Claims (1)

(57) [Claims] A pickup roller for sequentially feeding a plurality of originals in contact with a plurality of stacked originals ;
A feed roller and a pair that rotates while contacting the feed roller
Consists of a counter roller, in RuHara draft conveying apparatus to transport at a predetermined speed the document on the document reading unit receives the document fed,
The form feed roller and at least the surface of said opposed rollers of a material respectively substantially the same characteristic, by the feed roller and the counter roller, the separable conveyed to one sheet multi-fed document, the opposed roller, With opposing rollers
Work together and give a driving force to the pickup roller
Transmission means for the feed roller,
Only the rotational force obtained by the opposing roller when pressed against
A rotary drive of the transmission means with respect to the pickup roller
A document feeder characterized by power .