JPH04333437A - Document feeding device - Google Patents

Abstract

PURPOSE:To realize a miniature and light document carrying system. CONSTITUTION:Both the side ends of transmitting manuscripts placed on a document mount 1 are caught with fixed and movable guide members 19 and 21. At that time, the position of a paper feeding roller 3 is set so that the slippage quantity, between the carrying enter positions of the transmitting documents and the paper feeding roller 3, can be minimized when the movable guide member 21 is moved to an outer and an inner side limit positions.

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 that separates and feeds a plurality of documents placed on a document table one by one.

0002

2. Description of the Related Art In recent years, as facsimile machines have become widespread, they are being installed in private offices and homes, and there is a growing demand for lower prices and smaller sizes of the machines.

Conventional facsimile machines are equipped with a center sorting type width direction guide mechanism that positions the center of the original to be sent so that the center of the document coincides with the center of the document in the conveyance direction. In this width direction guide mechanism, the left and right guide members are interlocked by an internal mechanism so that the center of the transmitted document and the center of the conveyance roller can be aligned regardless of the size of the transmitted document.

0004

[Problems to be Solved by the Invention] However, such conventional devices have the following disadvantages.

[0005] In other words, the center distribution type width direction guide mechanism requires an internal mechanism for interlocking the left and right guide members, which has the disadvantage of hindering miniaturization and cost reduction of the device. .

[0006] In order to eliminate this inconvenience, it is conceivable to provide a guide mechanism that abuts one side edge of the transmitted document against a fixed guide member, but with such a guide mechanism, when the size of the transmitted document changes, Since the center of the conveyance roller and the center of the transmitted document do not match, there arises a disadvantage that particularly large-sized transmitted documents are likely to be skewed.

The present invention has been made in order to eliminate the disadvantages of the conventional apparatus, and an object of the present invention is to provide a small and inexpensive document feeding device that can prevent the skew of transmitted documents.

[0008]

[Means for Solving the Problems] The present invention includes a fixed guide member that positions one side edge of a document placed on a document table, and a fixed guide member that is provided on the document table movably in a direction perpendicular to the document conveyance direction. A movable guide member that positions the other side edge of the document to be placed, and a conveyance center set at an intermediate position between the conveyance center position of the largest size document that can be conveyed and the conveyance center position of the smallest size document that can be conveyed. It is equipped with a conveyance roller that feeds the original document.

Furthermore, a plurality of linear protrusions parallel to the document conveyance direction are provided at predetermined first intervals in the range from the conveyance roller of the document table to the fixed guide member, while a plurality of linear protrusions are provided at predetermined first intervals in the range from the conveyance roller of the document table to the fixed guide member. A plurality of linear protrusions parallel to the document conveyance direction are provided at a second interval wider than the first interval in the range of the direction .

Further, the movable guide member extends in a direction perpendicular to the document conveyance direction according to the movable range of the movable guide member, fits into a guide groove provided on the document table, and also touches the side surface of the guide groove. It consists of a guide member made of resin and provided with a biasing member in contact with the guide member, and a leaf spring member provided on the guide member to bias the biasing member in the direction in which the biasing force of the biasing member is applied.

[0011]

[Operation] Therefore, the guide mechanism for the transmitted document is composed of a fixed guide member and a movable guide member, and there is no need for a mechanism for interlocking them, so that the apparatus can be constructed in a small size and at low cost. Furthermore, since the center portion of the transport roller is located near the center of each size of documents that can be transported, stable transport operations can be performed. Furthermore, the linear protrusions cause the frictional force that acts on the document to be sent to be almost uniform around the conveyance roller, making it difficult for skew to occur.

0012

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 shows a conveyance system of a document reading apparatus according to an embodiment of the present invention.

In the figure, a plurality of transmission documents 2 placed on a document table 1 are separated into sheets one by one by a paper feed roller 3 and a separation pad 4, and sent out in the conveying direction. After passing through the gap between the lower guide member 6 and the document reading position, the conveyance roller 7 and the driven roller 8
It is sent in between and discharged.

Further, the image surface of the transmitted document 2 is illuminated by a linear light source 9 at the document reading position, and the reflected light from the image surface of the transmitted document 2 sequentially passes through mirrors 10, 11, and 12. The light is reflected and guided to the lens 13, converged by the lens 13, and formed into an image on the light receiving surface of the line image sensor 14.

Further, the holder 15 is for holding the separation pad 4, and the clip 16 is for holding the separation pad 4.
This is for attaching the leaf spring 1 to the holder 15.
Reference numeral 6a applies a biasing force that biases the separation pad 4 to the paper feed roller 3.

The original sensor 17 is for detecting the transmission original 2 set on the original platen 1, and the original sensor 18 is for detecting the transmission original 2 placed immediately in front of the original reading position. The purpose is to detect Also,
The fixed guide member 19 supports the transmission document 2 placed on the document table 1.
This is to define the position of one side edge of the

The document table 1 and the lower guide member 6 are integrally molded, as shown in FIG. A guide groove 20 in which a guide groove 20 is set is provided on the document table 1. A movable guide member 21 is movably provided in the guide groove 20 for defining the position of the side end of the transmission document opposite to the fixed guide member 19.

The notch 22 is for passing the light from the light source 9 at the document reading position, and is for passing the light from the light source 9 at the document reading position.
Linear protrusions 23a, 23b, and 23c parallel to the conveying direction are provided in the range from Linear projections 24a, 24b, 24
c is provided. These linear projections 23a, 23b
, 23c, 24a, 24b, and 24c are for preventing the transmission original 2 from coming into close contact with the lower guide member 6 due to static electricity or the like. In addition, these linear protrusions 2
Although linear protrusions corresponding to 3a, 23b, 23c, 24a, 24b, and 24c are also provided on the upper guide member 5,
Illustrations are omitted.

Here, as shown in FIG. 3, when the movable guide member 21 is moved to the outer limit position of the guide groove 20 (hereinafter referred to as the outer limit position), the fixed guide member 19
and the fixed guide member 19 when the movable guide member 21 is moved to the inner limit position of the guide groove 20 (hereinafter referred to as the inner limit position).
When the distance between the fixed guide member 19 and the movable guide member 21 is Wmin, the distance L between the fixed guide member 19 and the conveyance center position of the paper feed roller 3 is set as shown in the following equation.

[0021]L=(Wmax+Wmin)/4

Therefore, when the movable guide member 21 is moved to any position in the guide groove 20 within the range from the outer limit position to the inner limit position, the fixed guide member 1
9 and the movable guide member 21, the center position of the side parallel to the direction perpendicular to the conveyance direction of the sending document 2, and the conveyance center position of the paper feed roller 3, that is, the conveyance center position of this conveyance system. Since the deviation is small, a stable conveyance operation can be performed for all sizes of transmission documents 2 that can be conveyed by this conveyance system.

[0023] Also, from the paper feed roller 3 to the fixed guide member 1
9 is narrower than the distance from the paper feed roller 3 to the movable guide member 21 when the movable guide member 21 is moved to the limit position outside the guide groove 20, and therefore,
The distance between the linear protrusions 23a, 23b, and 23c is the linear protrusion 24.
The distance is narrower than the distance between a, 24b, and 24c.

Therefore, when the movable guide member 21 is moved to the outer limit position to convey the maximum size transmission document 2, the linear protrusions 23a, 23b, 23c move against the paper feed roller 3.
Frictional force acting on the surface of the transmission document 2 in the range from
The frictional forces acting on the surface of the transmitted document 2 in the range from the paper feed roller 3 to the movable guide member 21 are approximately equal, and as a result, the skew of the transmitted document 2 is prevented.

Note that the linear protrusions 23a, 23b, 23c,
The intervals between 24a, 24b, and 24c are determined by the torque acting on the transmission document 2 due to the frictional force acting on the surface of the transmission document 2 in the range from the paper feed roller 3 to the fixed guide member 19, and the distance between the paper feed roller 3 The settings may be made so that the torques acting on the transmission document 2 due to the frictional forces acting on the surface of the transmission document 2 in the range from 1 to the movable guide member 21 are balanced.

Furthermore, the linear protrusions 23a, 23b, 23c and the linear protrusions 24a, 24b, 24c do not have to be arranged at approximately equal intervals. In other words, when a frictional force acts on the transmission document 2 at a position farther from the center of transport, the torque generated by the frictional force becomes larger.
For example, all the linear protrusions are arranged at equal intervals,
In the vicinity of the movable guide 21 that generates a larger torque,
It is also possible to thin out the linear protrusions as appropriate.

However, the linear protrusions 23a, 23b, 23c
, 24a, 24b, 24c, the original sensor 17,
18 and the like exert a frictional force on the transmission document 2, so the linear protrusions 23 are
It is necessary to set the arrangement mode of a, 23b, 23c, 24a, 24b, and 24c.

FIGS. 4 and 5 show an example of a mechanism for attaching the movable guide member 21 to the guide groove 20. FIG.

In the figure, the guide groove 20 is provided with a guide portion 20a projecting inward, and the movable guide member 21 has an engaging portion 21 that engages with the guide portion 20a.
A is provided.

The movable guide member 21 also has a guide groove 2.
Leg member 21 that can contact the surface facing the guide portion 20a of 0
b is provided at the tip of this leg member 21b,
A spring portion 21c that is displaced outwardly than the leg member 21b is connected to the protrusion 2 for receiving the spring portion 21c.
1d is attached to the engaging portion 21a.

Further, a leaf spring member 25 for preventing creep deformation of the spring portion 21c is housed in a portion surrounded by the engaging portion 21a, the leg member 21b, the spring portion 21c, and the protrusion 21d.

Therefore, while the engaging portion 21a of the movable guide member 21 is engaged with the guide portion 20a of the guide groove 20, and the spring portion 21c is deformed, the movable guide member 2
1 is assembled into the guide groove 20 and the leaf spring member 25 is further attached, the return force of the spring part 21c and the spring force of the leaf spring member 25 create a frictional force between the spring part 21c and the inner surface of the guide groove 20. This frictional force allows the movable guide member 21 to maintain a stopped position at any position in the guide groove 20.

Furthermore, since the movable guide member 21 is integrally molded from synthetic resin, there is a risk of creep deformation if the spring portion 21c is held for a long time with excessive weight applied to it. Since the spring portion 21c is biased by the leaf spring member 25, it is possible to prevent such creep deformation from occurring.

Note that the leaf spring member 25 can also be insert molded into the movable guide member 21.

Further, the protrusion 21d is provided to prevent the spring portion 21c from being plastically deformed due to an excessive amount of deformation when the spring portion 21c is deformed.

By the way, in the above-mentioned embodiment, the case where the present invention is applied to a document reading device of a facsimile machine has been described, but the present invention can be similarly applied to other document feeding devices. can.

[0037]

[Effects of the Invention] As explained above, according to the present invention,
Since the guide mechanism for the transmitted document is composed of a fixed guide member and a movable guide member, and there is no need for a mechanism for interlocking them, the apparatus can be constructed in a small size and at low cost. Furthermore, since the center portion of the transport roller is located near the center of each size of documents that can be transported, stable transport operations can be performed. Also,
Since the linear protrusions cause the frictional force acting on the transmitted document to be approximately uniform around the conveyance roller, an effect is obtained in which skew is less likely to occur.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view showing a conveyance system of a document reading device according to an embodiment of the present invention.

FIG. 2 is a schematic perspective view showing an example of a document table and a lower guide member.

FIG. 3 is a schematic plan view for explaining the positional relationship between a fixed guide member, a movable guide member, and a paper feed roller.

FIG. 4 is a partial perspective view showing an example of a mechanism for attaching a movable guide member to a guide groove.

FIG. 5 is a partial plan view for explaining the action of the movable guide member.

[Explanation of symbols]

3 Paper feed roller 19 Fixed guide member 20 Guide groove 20a Information department 21 Movable guide member 21a Engagement part 21b Leg member 21c Spring part 21d Protrusion 25 Leaf spring member

Claims (3)

[Claims] [Claim 1] Multiple sheets of originals placed on the original platen are
In a document feeder that separates and feeds sheets one by one, there is a fixed guide member that positions one side edge of the document placed on the document table, and a document table that is movable in a direction perpendicular to the document conveyance direction. A movable guide member that positions the other side edge of the document placed on the document, and a movable guide member that positions the conveyance center at an intermediate position between the conveyance center position of the largest size document that can be conveyed and the conveyance center position of the smallest size document that can be conveyed. A document feeding device characterized by comprising a conveyance roller that feeds a set document. 2. A plurality of linear protrusions parallel to the document conveyance direction are provided at predetermined first intervals in a range from the conveyance roller of the document table to the fixed guide member; 2. A plurality of linear protrusions parallel to the document conveyance direction are provided at a second interval wider than the first interval in a range from the roller to the movable guide member. document feeder. 3. The movable guide member extends in a direction perpendicular to the document conveyance direction according to the movable range of the movable guide member, and fits into a guide groove provided on the document table, and also extends from a side surface of the guide groove. A guide member made of resin is provided with a biasing member that comes into contact with the guide member, and a leaf spring member is provided on the guide member and biases the biasing member in the direction in which the biasing force of the biasing member acts. 3. The document feeding device according to claim 1 or claim 2.