JPH08272162A - Image reading device - Google Patents

Abstract

PURPOSE: To provide an image reading device which keeps the copy transporting speed in the reading position constant at all times and conduct the reading of copy image in good performance. CONSTITUTION: A drum 40 is installed on the rotary shaft 31 of a transport drive roller 11, and in the position engaged by this drum 40, a brake 41 as a load means is installed on a side plate 24. The brake 41 is composed of a brake shoe 42 contacting with the drum 40 and a spring 43 which presses the shoe 42 so as to be in contact with the drum 40 with a certain pressing force, and the the rotary shaft 31 of the roller 11 is given a certain load by the brake 41.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image reading apparatus such as a copying machine, a facsimile and a scanner, and more particularly to an image reading apparatus for reading a document conveyed to a fixed document reading position as needed. It is a thing.

[0002]

2. Description of the Related Art Conventionally, in an image reading apparatus such as a copying machine, a facsimile, a scanner, etc., a separating / conveying means for separating and conveying the originals placed on an original placing table one by one, and a separate conveying means. An original document transport unit having a transport unit for transporting the original document to the original document reading position, and an image reading unit provided below the original document transporting unit for reading the image of the original document transported to the original document reading position by the original document transportation unit as needed. And
The document feeding operation and the document reading operation were performed.

[0003]

However, in such a device, the separating and conveying means and the conveying means both have an equal conveying speed, or the conveying means conveys at a higher speed than the separating and conveying means. Is set to do. In that case, the separating / conveying means frictionally separates a plurality of originals placed on the original placing table one by one, so that the conveying speed may decrease due to the frictional separation action. Therefore, the document conveyance speed is lower than the conveyance speed of the conveyance unit by the conveyance speed of the separation conveyance unit, and the document conveyed by both the separation conveyance unit and the conveyance unit is conveyed while being pulled by the conveyance unit. To be done. Therefore, when the original is being conveyed by both the separating and conveying means and the conveying means, the conveying means is loaded by the original in the direction opposite to the original conveying direction.

After that, when the trailing edge of the original is conveyed from the separating / conveying means, the original is conveyed only by the conveying means, and the conveying means receives a load in the direction opposite to the original conveying direction by the original. It's gone. If you do,
The original document jumps out (instantaneously increases the original document conveyance speed) due to play (backlash or the like) of the drive system of the conveyance means, and the original document conveyance speed of the conveyance device becomes instantaneously unstable. .

Therefore, in such a case, the leading end of the document is already conveyed to the document reading position by the conveying means,
Since the reading of the original image has been started, there is a problem in that the read original image is distorted due to a momentary unevenness of the original feeding speed, and the original image cannot be read well.

SUMMARY OF THE INVENTION Therefore, the present invention solves the above-mentioned conventional problems, and an object of the present invention is to maintain a constant document feeding speed at a document reading position and read a good document image. .

[0007]

SUMMARY OF THE INVENTION In order to achieve the above-mentioned object, the present invention supplies an original placing table on which an original is placed, an original placed on the original placing stand, and feeds the original. Sequentially 1
Separating and conveying means for separating and conveying the sheets one by one, conveying means for conveying the documents separated and conveyed from the separating and conveying means to the reading position, and reading means for reading the documents conveyed to the document reading position by the conveying means at any time, There is provided an image reading apparatus including a load unit that applies a load to the transport unit during document transport.

Further, the conveying means is composed of a driving roller which is driven to rotate and a driven roller which is driven to rotate by being pressurized by the driving roller, and the load means is the driving roller. There is provided an image reading device which applies a load to the rotation axis of the.

[0009]

According to the structure of the present invention, even if the trailing edge of the original being conveyed by the conveying means is conveyed from the separating / conveying means, the conveying means keeps a certain load on the conveying means during the conveyance of the original. Therefore, backlash or the like does not occur in the drive system of the conveying means, the document is always conveyed at a constant conveyance speed, and the document image is read at a constant speed at the document reading position.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an image reading apparatus to which the present invention is applied will be described in detail below with reference to the drawings. FIG. 1 is a main cross-sectional explanatory view of an image reading apparatus to which the present invention is applied, and FIG. 2 is a cross-sectional explanatory view of a document feeding unit in the image reading apparatus to which the present invention is applied. In FIG. 1 and FIG. 2, the image reading apparatus 1 includes a document feeding section 2 provided on an upper part of the apparatus main body and a pressure plate type document placing section 3 provided on the right side of the document feeding section 2 in the drawing. And an image reading unit 4 capable of reading a document conveyed by the document conveying unit 2 and reading a document placed on the pressure plate type document placing unit 3. Here, since the pressure plate type document placing section 3 has the same configuration and operation as the conventional one, detailed description thereof will be omitted.

The original document transport section 2 is in contact with the original document table 6 on which a plurality of original documents 5 are placed, and the uppermost surfaces of the plurality of original documents 5 placed on the original document table 6 to feed the original documents 5. A pickup roller 7 for sending and a separation roller for separating and feeding the originals 5 fed by the pickup roller 7 one by one.
The separating / conveying means composed of the roller 8 and the blocking roller 9, and the separating roller 8 and the blocking roller 9 convey the separated and conveyed original document 5 to the original reading position located on the slit glass 10. For driving and rotating, and a driven roller 12 that is drivenly rotated by being pressed and abutted on the upstream side of the original reading position in the original conveying direction.
And a conveying means including a driven roller 13 which is arranged in pressure contact with the downstream side of the original reading position in the original conveying direction and is driven to rotate, and a conveying drive roller 11 and a driven roller. 1
A discharge roller 14 for discharging the read document 5 conveyed by the sheet 3, and a document 5 discharged by the discharge roller 14.
And a discharge tray 15 for accommodating and accumulating.

The original reading section 4 has a light source 16 for irradiating the original 5 conveyed to the original reading position on the slit glass 10.
The first mirror 17 for reflecting the light beam emitted by the light source 16 and the document reading means including a CCD or a lens (not shown) are provided, and the document is conveyed to the document reading position on the slit glass 10. 5 is read at any time.

The original placing table 6 has a plurality of originals 5 placed thereon.
A document guide (not shown) for regulating the alignment of the document is provided, and the leading end portion of the document 5 with the image surface facing upward is inserted into the document insertion port 18 and placed. A pickup roller 7 is arranged at a position facing the leading end portion of the document 5 placed on the document placing table 6, and the pickup roller 7 is provided.
Is attached to a rotary shaft 22 which is rotatably supported by side plates 20 and 21 via a bearing 19 and is vertically movable by a moving mechanism (not shown). When a start key (not shown) is pressed, a paper feed signal is output from the main body of the apparatus, and the pickup roller 7 is moved downward by a moving mechanism (not shown) for a predetermined time to carry out the document feeding operation. .

The separation roller 8 is mounted on the side plate 2 via a bearing 23.
It is attached to a rotary shaft 26 which is rotatably supported by the rotary shafts 4 and 25. A pulley 27 is attached to the rotary shaft 26. The timing belt 29 spanned by the pulley 27 and the pulley 28 attached to the rotary shaft 22 causes the rotary shaft 26 to rotate.
When the rotation shaft 26 of the separation roller 8 rotates, the rotation shaft 2 of the pickup roller 7 is rotated.
2 is designed to rotate in the same direction. The blocking roller 9 is disposed under pressure on and in contact with the lower portion of the separation roller 8, is rotationally driven in the direction opposite to the rotation direction of the separation roller 8, and is fed. This is for preventing double feeding of the original document 5.

The transport drive roller 11 has a rotating shaft 31 rotatably supported by the side plates 24 and 25 via a bearing 30.
Attached to. At one end of the rotary shaft 31,
A pulley 32 is attached, and the pulley 32 is engaged with a drive motor 35 via a timing belt 33 and a pulley 34. On the other hand, on the other end of the rotary shaft 31, the gear 3
6 is attached and via two idle gears 37,
The one-way clutch 3 is attached to one end of the rotary shaft 26 of the separation roller 8.
It is engaged with a gear 39 mounted via 8.
Therefore, when the rotation shaft 31 of the conveyance drive roller 11 is rotated by the rotation drive of the drive motor 35, the rotation shaft 26 of the separation roller 8 is rotated in the same direction. The rotation of the roller 11 is transmitted to the separation roller 8. Further, the separation roller 8 is configured to rotate around in the document conveying direction by the one-way clutch 38.

A drum 40 is attached to the rotary shaft 31 of the transport drive roller 11. This drum 40
A brake 41 as a load means is provided on the side plate 24 at a position to be engaged with. This brake 41 is a drum 4
0, and a spring 43 for pressing the brake 42 so as to contact the drum 40 with a constant pressing force.
The rotary shaft 31 of the rotor 11 is given a constant load by the brake 41.

According to this structure, since the brake 41 for applying a constant load is provided on the rotary shaft 31 of the transport driving roller 11, the rear end of the transported document 5 is blocked from the separating roller 8. Even if it is conveyed from between the rollers 9, the conveyance driving roller 1
It is possible to prevent the original document from jumping out due to the play of the drive system 1, and the original document 5 is always conveyed constantly by the conveyance drive roller 11 so that a good image can be read.

The paper output roller 14 is engaged with the gear 36 via a rotary shaft, a gear and an idle gear (not shown).
When the rotation shaft 31 of the transport drive roller 11 is rotated by the rotation drive of the drive motor 35, the paper discharge roller 14 is rotated.
Is configured to rotate in the direction opposite to the rotation direction of the transport drive roller 11, and discharges the transported document 5 after reading to the discharge tray 15.

[0019]

According to the present invention, the load means for applying a load to the conveying means during the conveyance of the original by the conveying means is provided, so that even if the trailing end of the conveyed original is conveyed from the separating / conveying means. It is possible to prevent the original from jumping out due to play in the drive system of the conveying means, and the original is constantly conveyed by the conveying means, so that a good image can be read.

[Brief description of drawings]

FIG. 1 is a main cross-sectional explanatory view of an image reading apparatus to which the present invention has been applied.

FIG. 2 is an explanatory cross-sectional view of a document feeding unit in the image reading apparatus to which the present invention is applied.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Image reading device 2 Original conveying section 3 Image reading section 5 Originals 6 Original placing table 7 Pickup roller 8 Separation roller 8 Blocking roller 10 Slit glass 11 Transport drive roller 12 Driven roller 13 Driven roller -La 14 Ejecting Roller 15 Ejecting Tray 40 Drum 41 Brake 42 Brake Kiss 43 Spring

Claims (2)

[Claims] 1. An original placing table on which an original is placed, a separating / conveying means for feeding the originals placed on the original placing table and sequentially separating and conveying the originals one by one, and from the separating / conveying means. Conveying means for conveying the separately conveyed originals to the reading position,
An image reading apparatus including a reading unit that reads a document conveyed to a document reading position by the conveyance unit as needed, and an image including a load unit that applies a load to the conveyance unit during document conveyance. Reader. 2. The transport means comprises a drive roller which is driven and rotated, and a driven roller which is driven and rotated by being pressurized by the drive roller.
2. The image reading apparatus according to claim 1, wherein the load means applies a load to the rotation shaft of the drive roller.