JPH06219571A - Document conveyor - Google Patents

Abstract

PURPOSE:To make low-unit cost of production and miniaturization achievable by promoting the simplification of structure. CONSTITUTION:In this document conveyor, both surfaces of a feed roller 32 and an opposite roller 33, constituting a conveyor roller conveying a document to a document reading part 10 at a specified speed, are formed with the same characteristic material, and if this feed roller 32 is rotated and driven, the opposite roller 33 is made so as to be dragged into rotation together in terms of design. In addition, if one document gets into space between the feed roller 32 and the opposite roller 33, these rollers 32, 33 are dragged together, conveying the document as keeping it intact, and supposing double-feed of the document has occurred, the opposite roller 33 is not turned at all, so that only the lowermost document is conveyed by rotation of the feed roller 32.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a document feeding device applied to a document reading device such as a facsimile machine or an image scanner, and a document feeding device for separating and feeding a plurality of loaded documents one by one and sending them to a document reading position.

[0002]

2. Description of the Related Art FIG. 7 is a schematic configuration diagram of a conventional facsimile machine. Reference numeral 1 is an apparatus main body, 2 is an apparatus main body 1, an original placing table on which an original 3 is loaded, and 4 various operation keys. It is an operation board provided with
At the extension of the document table 2 below the operation board 4, there is a pickup roller 5, a pressure plate 6 facing the pickup roller 5, a document separating / conveying section 9 including a separating roller 7 and a feed roller 8, Document scanning 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 discharge roller 12 for transporting the document 3 after reading is provided outside.

A light source 15 for illuminating the surface of the original, a reflection mirror 17 for deflecting the reflected light from the original in the CCD (charge coupled device) 16 direction, and an image forming in front of the CCD 16 are provided under the original conveying section 13. An original reading optical system 19 including a lens 18 and the like is installed.

Below the original reading optical system 19, a roll-shaped thermal recording paper 20, a thermal head 21, a platen roller are provided.
A recording unit 25 including a recording paper cutter 23, a recording paper cutter 23, and a recording paper discharge roller 24 is installed.

In the above-mentioned facsimile apparatus, upon reception, the thermal recording paper 20 is printed between the thermal head 21 and the platen roller 22 on the basis of the received data in a known manner, and the thermal recording paper 20 after printing is the recording paper. The sheet is cut into 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 fed between the pressure plate 6 and the pickup roller 5,
When the transmission operation is started, the pickup roller 5 feeds the document separation / conveyance unit 9 from the lowest paper of the stacked documents 3. In the document separating / conveying unit 9, when the document 3 is double-fed from the pickup roller 5, the separating roller 7 and the feed roller 8
The originals are separated one by one by and and sent to the conveyance roller 11.

The original 3 includes a transport roller 11 and a paper discharge roller.
While being conveyed by 12, the document reading section 10 is illuminated by the light source 15 to perform known optical image reading by the CCD 16 and image data output.

[0008]

In the document feeder 13 of the conventional facsimile machine, the function is roughly divided into a pickup roller 5 for pre-feeding the document and a document when the document is double fed. A document separating / conveying unit 9 for separating and conveying the sheets one by one and a conveying roller 11 for feeding the document to the document reading unit 10 at a predetermined speed are required, and the structure is composed of rollers, rollers and their related parts that constitute each unit. However, it is complicated, and the installation space for them is required, which is one of the causes of high cost and large size of the entire apparatus.

It is an object of the present invention to provide a document feeder which can be simplified in construction, cost reduction and size reduction.

[0010]

To achieve the above object, the present invention provides a pickup roller for contacting a plurality of stacked originals and sequentially feeding the originals, and an original reading unit for receiving the fed originals. In a document feeder including a feed roller for feeding a document at a predetermined speed, at least the surfaces of a feed roller that constitutes the feed roller and a counter roller that comes into pressure contact with the feed roller are made of materials having substantially the same characteristics. However, it is characterized in that the double-fed original can be separated and conveyed into one sheet by the feed roller and the counter roller.

The opposing roller is made of a material having a friction coefficient which is the same as or slightly smaller than that of the feed roller.

Further, it is characterized in that the opposed roller is provided with a transmission means interlocking with the opposed roller and for applying a driving force to the pickup roller.

Further, the present invention is characterized in that only the rotational force obtained by the opposed roller when the opposed roller is pressed against the feed roller is used as the rotational driving force of the transmission means.

[0014]

According to the above-mentioned means, since the contact surfaces of the feed roller and the counter roller, which constitute the conveyance roller for conveying the document at a predetermined speed, are made of the same material, the counter roller is rotated when the feed roller is driven to rotate. When the original is placed between the feed roller and the opposing roller, the original is conveyed to the original reading section as it is, and when the originals are double-fed, the feeding roller conveys only the lowest original to the original reading section. Will be
The transport roller also serves as the document separating and transporting unit.

If the friction coefficient of the surface of the feed roller is made slightly larger than that of the opposed roller, the original can be conveyed by the feed roller even if the opposed roller does not rotate together.

Further, when the opposing roller is rotated, a rotational driving force is applied to the pickup roller via the transmission means, so that the rotation driving mechanism of the pickup roller is simplified.

Further, since the transmission means is rotationally driven only by the rotational force from the feeding roller to the opposing roller when the opposing roller is pressed against the feeding roller and rotates together, the rotation driving mechanism of the pickup roller is simplified. In addition, the timing of feeding the document between the pickup roller and the feeding roller is improved.

[0018]

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

FIG. 1 is a block diagram showing a front surface of a main part in one embodiment of the present invention, and FIG. 2 is a block diagram showing a plan view of the main part of FIG. A pickup roller 30 is installed above the setting table 2, and an extension part of the document setting table 2 which is a document conveyance path is provided with a shutter 31, a feed roller 32, and a counter roller 33 that can move up and down to block the document conveyance path. A transport roller 34 is provided.

A rotation 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 via 38. Further, the opposing roller 33 is provided with a rotary shaft 39
It receives the urging force of the pressure leaf spring 40 that makes elastic contact with the feed roller 32.
Is pressed on the upper side of. Further, the rotation support shaft 39 of the opposing roller 33 is provided with a drive gear 43 that is a transmission means that is connected to a driven gear 41 provided on the pickup roller 30 via a belt 42.

At least the surfaces of the feed roller 32 and the counter roller 33 are made of a rubber material or materials having substantially the same characteristics. Reference numeral 44 in FIG. 2 denotes a spring clutch provided on the rotary shaft 45 of the pickup roller 30.

The present embodiment is a so-called upper feed device, and in the case of this upper feed, the uppermost one of the stacked originals is fed.

That is, the original 3 placed on the original placing table 2 is set at a predetermined position with its leading end in contact with 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 to rotate the feed roller 32. Since the surface of the facing roller 33 is the same as that of the feed roller 32,
When the feed roller 32 rotates, it rotates together.

When the opposed roller 33 rotates, the rotational force is transmitted from the drive gear 43 of the opposed roller 33 to the driven gear 41 of the pickup roller 30 via the belt 42, and the pickup roller 30.
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 carrying roller 34, but when the originals are double-fed, the carrying roller 34 separates and carries them, and only one original is shown in FIG. The document is conveyed to the document reading unit 10 described above based on a predetermined speed.

FIG. 3 is an explanatory view for explaining the relationship of forces at the conveying roller 34 part, and shows a state in which two originals 3 have entered the nip portion between the feed roller 32 and the counter roller 33. Here, the document blocking force Ta for blocking the conveyance of the upper document of the two documents 3 is set so that the formula (Equation 1) is satisfied.

[0027]

## EQU1 ## Ta> F _C −R _D + R _B where:

[0028]

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 original, μ _P is the friction coefficient between the originals, X is the number of originals set, and P _B is the facing roller 33.
Is the pressing force of.

When the above equation (1) is satisfied, the upper document of the two documents 3 can be separated. Therefore,
A frictional force satisfying the equation (1) is generated between the rotation support shaft 39 of the opposed roller 33 and the pressure leaf spring 40.

FIG. 4 is a perspective view showing an example of the structure for generating the frictional force. A plurality of protrusions 50 are provided on the side of the opposing roller 33.
Is provided with a stopper plate 51, and the rotary support shaft 39 of the opposing roller 33 is provided with a sliding body 53 having a receiving hole 52 for fitting with the projection 50, and the sliding body 53 has a compression spring 54 A friction plate 55 that presses against elastic force is provided, and a cutout portion 55a is formed in a part of the friction plate 55, and the cutout portion 55a is a rotation stopper member provided in an appropriate member in the apparatus main body. Locked at 56,
The frictional force is obtained by stopping the rotation of the friction plate 55.

FIG. 5 is a perspective view showing another example of the structure for generating the frictional force. A friction material 60 having a large friction coefficient is provided on a pressure leaf spring 40 elastically contacting the rotation support shaft 39 of the opposed roller 33. The installation portion of the material 60 is elastically contacted with the rotary support shaft 39.

In FIG. 3, the frictional force is set so that when one original enters the nip width of the feed roller 32 and the counter roller 33, the original can be conveyed by losing the conveying force of the original 3. It is necessary to leave. That is, when the number of originals is one, the originals cannot be conveyed unless the counter roller 33 rotates together. Therefore, it is necessary to satisfy the equation (3).

[0033]

## EQU3 ## F _C −R _D + R _B <Ta <F _B −R _B where:

[0034]

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

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

When the pickup roller 30 rotates while the opposed roller 33 is stopped, as shown in FIG.
Causes the leading end to be locked by the opposing roller 33, which causes a bulge between the opposing roller 33 and the pickup roller 30 and causes a jam, but as described above, when the opposing roller 33 is stopped. By stopping the pickup roller 30, it is possible to prevent the occurrence of the jam.

The material of the opposing roller 33 and the feed roller 32 is the same, or the material of the opposing roller 33 having a slightly low friction coefficient is used. As a result, when one original is sandwiched between the feed roller 32 and the counter roller 33 and is conveyed, even if the counter roller 33 is prevented from rotating together, the feed roller 32 If the coefficient of friction is larger, the original can be reliably fed without jamming.

In the above-described embodiment, the so-called up-conveying conveying device has been described as an example, but the so-called down-conveying conveying device in which the pickup roller 30 is installed under the document placing table 2 and conveys from the lowest document. The present invention can also be implemented in.

[0039]

As described above, according to the document feeder of the present invention, according to the structure of claim 1, the feeding roller for feeding the document to the document reading portion at a predetermined speed separates the documents one by one. Since it also has a document separation function for conveying, the configuration can be simplified, and the cost and size can be reduced.

According to the second aspect of the present invention, the feed roller forming the feed roller and the opposing roller that rotates together with the feed roller have the same or slightly smaller friction coefficient on their surfaces. Even if the roller does not rotate, the document can be conveyed by the feed roller.

According to the third aspect of the invention, the opposed roller drives the pickup roller to rotate via the transmission means, so that the rotation driving mechanism of the pickup roller can be simplified.

According to the fourth aspect of the invention, the opposing roller receives the rotational force of the feed roller and can rotationally drive the pickup roller via the transmission means. Therefore, the rotation driving mechanism of the pickup roller is simple. As well as
It is possible to improve the timing of document transportation between the pickup roller and the transportation roller.

[Brief description of drawings]

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

FIG. 2 is a configuration diagram showing a planar state of a main part of FIG.

FIG. 3 is an explanatory diagram of a relationship of forces in a conveyance roller portion.

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

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

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

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

[Explanation of symbols]

2 ... manuscript table, 3 ... manuscript, 10 ... manuscript reading unit, 30
... Pickup roller, 31 ... Shutter, 32 ... Feed roller, 33 ... Opposing roller, 34 ... Conveying roller, 35 ... Motor, 40 ... Pressing leaf spring, 41 ... Driven gear, 42 ... Belt, 43 ... Drive gear (transmission means) .

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location H04N 1/00 108 B 7046-5C

Claims (4)

[Claims] 1. A document transporting apparatus, comprising: a pickup roller that contacts a plurality of stacked documents and sequentially feeds the documents; and a transport roller that receives the fed documents and transports the documents to a document reading unit at a predetermined speed. In the apparatus, at least the surfaces of a feed roller that constitutes the conveyance roller and a counter roller that comes into pressure contact with the feed roller are made of materials having substantially the same characteristics, and the feed roller and the counter roller form a document that is double-fed. An original conveying device characterized in that it can be separately conveyed to one sheet. 2. The document feeder according to claim 1, wherein a material having a friction coefficient which is the same as or slightly smaller than that of the feed roller is used for the facing roller. 3. The transmission means for interlocking with the opposing roller and for applying a driving force to the pickup roller is provided in the opposing roller.
The document feeder described. 4. The document feeder according to claim 3, wherein only the rotational force obtained by the opposed roller when the opposed roller is pressed against the feed roller is used as the rotational driving force of the transmission means.