JPH1095552A - Automatic original feeder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To feed the paper sheet with excellent accuracy so that no load is applied to an original. SOLUTION: An oscillation piece 18a is fitted in an oscillating manner around a shaft 34, and elastically repulsively energized in the direction of the axis of rotation of a carrying roller 14 by an elastic repulsive member 18b. A projected piece 22 to be engaged with a slidably fitted engagement member 24 is formed on the oscillation piece 18a. When an original in which excellent resolution is required is read, the engagement member 24 slides in the direction of engagement with the projected piece 22 to give the pressing force to the projected piece 22 (oscillation piece 18a). The oscillation piece 18a is oscillated in the direction in which the elastic repulsive member 18b is contracted, i.e., in the direction in which a separator pad 20 is separated from the carrying roller 14. Thus, no load is applied to the original guided to an original reading part 28.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic document feeder, and more particularly to an automatic document feeder which is applied to, for example, a printer, a facsimile, a copying machine, etc., and which conveys a document set at a predetermined position one by one to a document reading section. It relates to a feeding device.

[0002]

2. Description of the Related Art A conventional automatic document feeder 1 of this type shown in FIG. 3 includes a paper feed plate 3 and a separator 4 which are mounted to be swingable about shafts 2a and 2b. Is elastically urged by the elastic members 3a and 4a in a direction toward the rotation axis of the transport roller 5. That is, a predetermined pressing force is applied to the transport roller 5 by the sheet feed plate 3 and the separator 4. When the transport roller 5 is driven, the plurality of originals set in the paper feed port 6 are separated by the paper supply plate 3 and the separator 4, and the originals are guided one by one to an original reading unit (not shown). I will

[0003]

In a conventional automatic document feeder, a pressing force is applied to a document to be conveyed by a resilient member in a direction toward the rotation axis of the conveyance roller 5,
Since the original is separated by the frictional resistance between the transport roller 5 and the separator 4 (the paper feed plate 3), the end of the original is located at the transport roller 5 and the separator 4 (the paper feed plate 3).
The load fluctuated on the document when the contact point was exceeded. This load fluctuation causes a problem that the document conveying speed varies, and as a result, an image different from the original document image is recognized in the document reading unit, and an image expanded and contracted in the document conveying direction is output. Had to be done. This phenomenon is particularly conspicuous when reading a photographic original or the like that requires a delicate halftone.

SUMMARY OF THE INVENTION Therefore, a main object of the present invention is to provide an automatic document feeder capable of accurately conveying a document.

[0005]

SUMMARY OF THE INVENTION According to the present invention, there is provided a conveying roller for guiding a document to be read in a document reading section to a document reading section according to a predetermined conveying path, and the outer peripheral surface of the conveying roller being contacted by the resilient force of a resilient member. An automatic document feeder including a separator for separating the document by using a separating means for forcibly separating the separator from the outer peripheral surface of the transport roller.

[0006]

When reading an original such as a photographic original which requires a high resolution, the first engagement portion and the second engagement portion are engaged with each other to forcibly separate the separator from the transport roller. Then, a gap is formed between the transport roller and the separator. Therefore, no load is applied to the document passing between the transport roller and the separator,
Documents can be transported at a uniform transport speed.

On the other hand, when reading a character document that does not require much resolution, no separating means is used, so that the separator elastically contacts the outer peripheral surface of the transport roller.

[0008]

According to the present invention, even if an automatic document feeder is used in which the separator comes in contact with the transport roller and feeds one sheet at a time, the separator and the transport roller can be separated as needed, so that the original can be separated. Can be sent under a uniform load, and the document can be conveyed with high accuracy. Further, it can be realized with a simple and inexpensive configuration.

The above objects, other objects, features and advantages of the present invention will become more apparent from the following detailed description of embodiments with reference to the drawings.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An automatic document feeder 1 according to this embodiment shown in FIG.
Reference numeral 0 denotes a device for transporting a document (not shown) set in the paper feed port 12 according to a predetermined document transport path, and includes a transport roller 14 that rotates in the direction of the arrow. Then, a driving force from a motor (not shown) is transmitted to the conveying roller 14, and the driving force
4 is conveyed.

As shown in FIG. 1, a paper feed plate 16 and a separator 18 are arranged above the transport roller 14 in this order from the upstream in the document flow direction. The sheet feed plate 16 includes a swinging piece 16 a having one end in contact with the outer peripheral surface of the transport roller 14 and the other end swingably attached to the shaft 32, and the swinging piece 16 a
And one end of the swinging piece 16a is elastically contacted with the outer peripheral surface of the transport roller 14 by the elastic member 16b.

In the document flow direction, the paper feed plate 16
A separator 18 disposed on the downstream side of the sheet feed roller 16, similarly to the sheet supply plate 16, is provided with a swinging piece 18 a that is swingably mounted around a shaft 34, and presses the swinging piece 18 a in the rotation axis direction of the transport roller 14. And a resilient member 18b.
At one end of 8 a, a separator pad 20 that contacts the outer peripheral surface of the transport roller 14 and separates the original that has passed through the paper feed plate 16 is provided. Accordingly, the separator pad 20 is held in a state of being in elastic contact with the transport roller 14. Further, the separator pad 20 is formed of a member having an appropriate frictional resistance on the surface such as cork, for example.

At the approximate center of the swinging piece 18a, the transport roller 1
Projecting piece (first engaging portion) 2 projecting in a direction away from
2 are formed, and an engaging member (second engaging portion) 24 is provided in association with the protruding piece 22. The projecting piece 22 and the engaging member 24 form a separating means, and the two are engaged with each other to separate the separator pad 20 and the transport roller 14 from each other.

That is, in this embodiment, the engaging member 24 is manually slidable in the direction of the arrow along a groove 27 formed on the upper surface of the housing 25 of the automatic document feeder 10. , This engagement member 24
As shown in FIG. 2, the slider is slid to the direction of approaching (engaging) the protruding piece 22 (left direction in FIG. 1), that is, to the first position, to apply a leftward pressing force to the protruding piece 22. This allows the separator 18 to swing around the axis 34. Therefore, the separator pad 20 that has been in contact with the outer peripheral surface of the transport roller 14 is separated from the transport roller 14.

On the other hand, by sliding the engaging member 24 away from the projecting piece 22 (to the right in FIG. 1), that is, to the second position, the swinging piece 18a is rotated around the axis 34 (in this embodiment, (Rotational direction) is allowed. Therefore, the rocking piece 18a is
b, the separator pad 20 is resiliently urged in a direction toward the rotation axis of the transport roller 14, and separates the separator pad 20 from the transport roller 14.
Is held in a state of being elastically contacted (the state of FIG. 1).

In the operation, when reading an original such as a character original that does not require much resolution (designating the separation mode), the engaging member 24 is moved as shown in FIG.
Manually slide to the second position along groove 27. This allows the swinging piece 18a to swing around the axis 34. Therefore, the rocking piece 18a is
As a result, the conveying roller 14 is resiliently urged in the rotation axis direction, and the separator pad 20 is held in a state where an appropriate pressing force is applied to the conveying roller 14. And
The original set in the paper feed port 12 with its original surface facing down and passed through the paper feed plate 16 is placed on the separator pad 2.
0 separates exactly one sheet at a time. The document that has passed through the separator pad 20 is guided to a document reading unit 28 by a pair of conveying rollers 26, and the document reading unit 28
After the original surface is optically read, the paper is ejected by the following pair of conveying rollers 30.

On the other hand, when reading an original such as a photographic original which requires a high resolution (designating the image emphasis mode), as shown in FIG. Slide to position. Then, the protruding piece 22
Is pressed by the engagement member 24, and swings around the shaft 34 (in the direction opposite to the clockwise direction in FIG. 2) in the direction in which the swinging piece 18a contracts the resilient member 18b. Therefore, the separator pad 20 is separated from the transport roller 14, and a gap is formed between the transport roller 14 and the separator pad 20. Accordingly, since no load is applied to the document conveyed to the document reading unit 28, the load fluctuation occurring at the point of contact between the conveyance roller 14 and the separator pad 20 can be eliminated, and the document can be uniformly loaded, and hence the document can be uniformly loaded. It is sent at the transport speed. In the image-oriented mode, document separation by the transport roller 14 and the separator pad 20 is disabled, so that documents are set one by one in the paper feed port 12.

In this embodiment, when reading an original such as a photographic original which requires a high resolution, the separator pad 20 which applies a load to the original is separated from the transport roller 14 so that the continuous operation is performed. Although a plurality of originals cannot be conveyed, the image reading accuracy can be improved without causing disturbance such as expansion and contraction of the image.

Further, by simply manually displacing the engagement member 24 to the second position or the first position, the separator pad 2
Since the roller 0 and the transport roller 14 can be brought into contact with or separated from each other, it is possible to realize highly accurate document transport with a simple configuration without load fluctuation without using expensive components such as an electromagnetic clutch. As a means for displacing the engagement member 24, a relatively inexpensive means such as a relay, solenoid or motor (not shown) is used.
The engagement member 24 may be electrically switched to the first position or the second position.

[Brief description of the drawings]

FIG. 1 is an illustrative view showing one embodiment of the present invention and showing a state in which a separation mode is designated for printing a document which does not require much resolution;

FIG. 2 is an illustrative view showing a state in which an image emphasis mode is designated for printing a document requiring high resolution in the embodiment of FIG. 1;

FIG. 3 is an illustrative view showing a conventional technique;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Automatic document feeder 12 ... Paper feed port 14 ... Conveyance roller 16 ... Paper feed plate 18 ... Separator 18a ... Swinging piece 18b ... Resilient member 20 ... Separator pad 22 ... Projection piece 24 ... Engaging member 28 ... Document reading Department

Claims (4)

[Claims] And a separation roller that guides the document to be read by the document reading section to the document reading section along a predetermined conveyance path, and separates the document by contacting an outer peripheral surface of the conveyance roller by a resilient force of a resilient member. An automatic document feeder, comprising: a separation unit for forcibly separating the separator from the outer peripheral surface of the transport roller. 2. The automatic document feeder according to claim 1, wherein said separation means includes a holding means for holding said separator in a state of being separated from said conveyance roller against said resilient member. 3. The separation means is displaceable to a first engagement portion provided on the separator and to a first position or a second position, and engages with the first engagement portion at the first position. A second engaging portion that is disengaged from the first engaging portion at the second position, and displaces the second engaging portion to the first position to move the separator to the transport roller. The automatic document feeder according to claim 1, wherein the automatic document feeder is separated from the automatic document feeder. 4. A part of the second engaging portion is exposed from a housing, and the second engaging portion is manually slid to move the second engaging portion to the first position or the second position. 4. The automatic document feeder according to claim 3, wherein the automatic document feeder is displaced to a position.