JPH09286547A - Document conveyer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent generation of improper reading due to a curve of conveying at image reading time and extension of an image caused by conveying resistance, by forming a second guide part provided to be opposed to a first guide part in an almost plane shape representing the shortest document conveying route between a feed means and a conveying means. SOLUTION: By a separating belt 10 and a separating roll 11, a document positioned in the uppermost is fed to be separated, to be conveyed onto a slit glass 2 through a conveying route 15 by a conveying roll pair 14. Since a second guide part 17 is formed so as to almost conform to a contact plane into contact with the separating roll 11 and a conveying roll 14a, friction resistance generated between the document and the second guide part 17 can be remarkably reduced. Consequently, a slip between the document and the conveying roll pair 14 can be suppressed, the document can be conveyed to a read position at a stable speed by the conveying roll pair 14. Accordingly, extension of the image, caused by a slip between the document and the conveying roll 14, is prevented, also a skew of the document can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a document feeder installed in a copying machine, a facsimile machine or the like, and more specifically, it separates and feeds a plurality of documents one by one. The present invention relates to a document feeding device that turns a document over and feeds it to a predetermined reading position.

[0002]

2. Description of the Related Art Conventionally, the apparatus is mounted on a copying machine, a facsimile machine or the like, and a plurality of originals are separated and fed one by one, and the fed originals are inverted and conveyed to a predetermined reading position. There is known a document conveying device. An example of a conventional document transporting device that reverses and transports such a document is, for example, a transporting drum having a drive source for a single document that has been separated and fed, and a plurality of documents disposed around the transporting drum. It is known that the original is reversed by nipping it with a roller or a roller to convey the original to a reading position.

Further, as a conventional document conveying apparatus for inverting and conveying a document, for example, an actual flat sheet 3-231 is used.
The one described in Japanese Patent No. 37 has been reported. This apparatus separates and feeds one document to a document transport path by a separation belt and a separation roller that is in sliding contact with the separation belt, and the fed document is a pair of transport rollers 21 and 22 and a pair of transport rollers 23 and 24. Is conveyed to the reading position by. The document feed path is provided opposite the outer guide part and the outer guide part that is curved so as to guide and reverse the document from the outside in the reversing direction of the document and guides the document from the inside in the reversing direction of the document. And an inner guide portion that is curved along the outer guide portion.

Further, in this apparatus, the spring 32 urges the auxiliary bracket 30 so that the driven roller 24 presses against the driving roller 23, thereby making the pressing contact force of the driven roller 24 against the driving roller 23 uniform. In addition to preventing jams, the number of parts is reduced to reduce costs.

[0005]

However, in the conventional document conveying apparatus in which a plurality of rollers and rollers are arranged on the conveying drum, the conveying drum itself is large, and since there are many rollers and rollers, the apparatus is large. As a result, the weight of the apparatus increases and the cost of the apparatus further increases.

Further, even in the document conveying apparatus disclosed in Japanese Utility Model Laid-Open No. 3-23137, since the driven roller unit 20 including the driven roller 24 is provided in addition to the two conveying roller pairs, the conveying rollers are also provided. There is a problem that the installation space for the pair is increased, the device is enlarged, and the device weight is increased, resulting in an increase in the device cost.
A document conveyed to the reading position is conveyed by being guided by a curved outer guide portion and an inner guide portion along a conveyance path, and is rubbed by the inner guide portion to cause conveyance resistance (friction resistance). ) Becomes large, and as a result, the conveying roller pair and the document slip, and a predetermined conveying speed cannot be obtained, and the read image is elongated.

The relationship between the feed speed V1 of the separation belt and the feed speed V2 of the pair of two conveying rollers is preferably V1 = V2, but is set so that V1 <V2 in order to prevent the slack of the document and the like. When the document fed by the belt is nipped by the transport rollers, the document is pulled upstream, and as a result, the document is rubbed by the curved inner guide portion and generates transport resistance. In addition, the actual feeding speed V1 of the separation belt
This is because the slip may have V1 ′ <V1 due to slip, the original is strongly pulled to the upstream side, and the conveyance resistance with the inner guide portion also increases.

Further, since the inner guide portion extends in the width direction of the document and the extending directions of the separating belt and the conveying roller pair are shorter than the extending direction of the inner guide plate, the separating belt slips. There is a problem in that a skew (conveyance bending) of a document occurs due to an increase in frictional resistance between the inner guide portion and a reading failure.
In view of this, the present invention reduces the frictional resistance between the inner guide surface and the original, and conveys the original to the reading position by the conveying means including a pair of conveying rollers and a pair of conveying rollers, thereby reducing the size, weight and cost. Another object of the present invention is to provide an original document conveying device that prevents image reading due to conveyance bending and image extension caused by conveyance resistance during image reading.

[0009]

In order to achieve the above object, the invention according to claim 1 is provided with a separating / feeding means for separating and feeding a plurality of originals one by one. In a document transporting device having a transport path for inverting the front and back of a document fed by the means, and transporting the document to a predetermined reading position, the document fed by the separating and feeding means is guided from the outside in the reversing direction and inverted. First for forming the transport path
A guide portion, and a second guide portion which is provided so as to face the first guide portion and guides the document fed by the separating and feeding means from the inside in the reversing direction to form the conveyance path;
Transporting means provided on the transporting path for transporting a document fed by the separating and feeding means and passing through the transporting path formed by the first and second guide portions to the reading position, The second guide portion is formed in a substantially flat shape that represents the shortest document conveying path between the feeding unit and the conveying unit.

According to the first aspect of the invention, the document fed by the separating and feeding means is guided by the first guide portion and inverted, and the shortest document feeding path between the feeding means and the feeding means is set. The sheet is guided by the second guide portion formed in a substantially flat shape, and is conveyed to the reading position by the conveying means. For this reason, the frictional resistance generated between the document and the second guide portion can be remarkably reduced and the conveyance resistance of the conveying means can be reduced. Therefore, the conveying means is composed of a pair of rollers or a pair of rollers. It is possible to realize downsizing, weight reduction and cost reduction of the device.
Further, since the original can be conveyed to the reading position at a stable speed due to the reduction of the frictional resistance, it is possible to prevent the image from spreading due to the original slip and prevent the original from skewing.

According to a second aspect of the present invention, in the first aspect of the invention, one end side of the second guide portion is fixed near the separating and feeding means of the second guide portion, and the other end side thereof is the first side. It is characterized in that a thin plate-like elastic member is provided close to the guide section on the side of the conveying means. In the invention according to claim 2, one end side of the second guide portion is fixed near the separating and feeding means of the second guide portion, and the other end side thereof is the first guide portion.
Since the thin plate-like elastic member is provided close to the guide means on the side of the conveying means, the elastic member forms a conveying path which becomes narrower toward the downstream side on the conveying path together with the first guide portion, and is separated by the separating and feeding means. The leading edge of the fed document can be smoothly guided to the conveying means. Therefore, it is possible to prevent the front end of the document from being folded and the tab from being folded. This is particularly effective for a document with a large curl. Further, when the original reaches the conveying means, it is elastically deformed toward the second guide portion and the frictional resistance with the original is significantly reduced, so that the conveying resistance of the conveying means can be reduced.

According to a third aspect of the present invention, a plurality of originals
In the original document feeder, which has a separating and feeding unit that separates and feeds each sheet, and has a conveying path that reverses the front and back of the original document fed by the separating and feeding unit to a predetermined reading position, A first guide portion which is formed of a curved curved surface for guiding and reversing the document fed by the separating and feeding means from the outside in the reversing direction, and which forms the conveyance path;
A second guide portion that is provided facing the guide portion and that has a curved curved surface that guides the document fed by the separating and feeding unit from the inside in the reverse direction, and that forms the transport path, and the transport path. And a conveyance unit that is provided above and conveys a document fed by the separation feeding unit and passing through the conveyance path formed by the first and second guide portions to the reading position. One end of the part is rotatably supported near the separating and feeding means, and is elastically supported so as to approach the first guide side with the one end side as a rotation axis.

According to a third aspect of the present invention, one end of the second guide portion is rotatably supported near the separating and feeding means, and the one end side of the second guide portion approaches the first guide side with the one end side as a rotation axis. Since it is elastically supported so that it forms with the first guide portion a conveying path that becomes narrower toward the downstream side on the conveying path, and the leading edge of the document fed by the separating and feeding means is smoothly guided to the conveying means. You can Therefore, it is possible to prevent the leading edge and the edge of the original from being broken. It is especially effective for documents with large curl. Further, when the original reaches the conveying means, the second guide portion is elastically deformed inward in the reverse direction of the original and the frictional resistance with the original can be remarkably reduced. It is possible to realize the miniaturization, weight reduction and cost reduction of the device. Furthermore, since the original can be conveyed to the reading position at a stable speed due to the reduction of the frictional resistance, it is possible to prevent the image from being stretched due to the original slip and prevent the original from skewing.

According to a fourth aspect of the invention, a plurality of originals
In the original document feeder, which has a separating and feeding unit that separates and feeds each sheet, and has a conveying path that reverses the front and back of the original document fed by the separating and feeding unit to a predetermined reading position, A first guide portion which is formed of a curved curved surface for guiding and reversing the document fed by the separating and feeding means from the outside in the reversing direction, and which forms the conveyance path;
A second guide portion that is provided so as to face the guide portion and guides the document fed by the separating and feeding means from the inside in the reverse direction to form the transport path; and a second guide portion that is provided on the transport path, Transporting means for transporting a document fed by the separating and feeding means and passing through the transport path formed by the first and second guide portions to the reading position, wherein the second guide portion transports the document. A conveyance path that passes through the conveyance means, and has a protrusion formed of a curved curved surface in which a central portion in a direction orthogonal to the direction is protruded toward the first guide portion side; It is characterized in that they are substantially matched.

According to another aspect of the invention, the document fed by the separating and feeding means is guided by the first guide portion and the second guide portion to be reversed, and is slidably brought into contact with the protruding portion of the second guide portion and conveyed. It is conveyed to the reading position by the means. For this reason,
Since it is possible to convey the original document while significantly reducing the frictional resistance generated between the original document and the second guide portion, the conveying unit can be configured by a pair of rollers, a pair of rollers, and the like, and the apparatus can be downsized. It is possible to realize weight reduction and cost reduction. Moreover, since the original can be conveyed to the reading position at a stable speed due to the reduction of the frictional resistance,
It is possible to prevent the extension of the image due to the slip of the document. Further, since the projecting portion in the vicinity of the conveying means is substantially aligned with the conveying path passing through the conveying means, even if the original has a large curl, the leading end of the original is smoothly conveyed by the conveying means. Can be guided to. Therefore,
It is possible to prevent the front end of the document from being broken and the tab from being broken.

According to a fifth aspect of the invention, in the invention of the fourth aspect, the second guide portion has a step portion formed of a curved surface on both sides of the projecting portion to form a substantially constant step with the projecting portion. It is characterized by In the invention according to claim 5,
Since the second guide portion is configured to have a step portion formed of a curved surface forming a substantially constant step with the protruding portion on both sides of the protruding portion, a direction orthogonal to the document conveying direction,
That is, the frictional resistance in the width direction of the original can be made uniform on the left and right, and the skew of the original can be prevented.

According to a sixth aspect of the invention, in the invention of the fourth aspect, the second guide portions are provided on both sides of the protrusion,
It is characterized in that it has an inclined portion formed of a curved surface that is inclined so as to be separated from the first guide portion as it is separated from both sides. According to a sixth aspect of the present invention, the second guide portion is configured to have, on both sides of the projecting portion, inclined portions formed of curved surfaces that are inclined so as to be separated from the first guide portion as the distance from each other increases. Therefore, the frictional resistance in the direction orthogonal to the document conveyance direction, that is, in the width direction of the document can be made uniform on the left and right, and the skew of the document can be prevented.

[0018]

Embodiments of the present invention will be described below with reference to the drawings. (First Embodiment) FIGS. 1 to 3 are views showing a preferred embodiment of a document feeder according to the present invention, wherein FIG. 1 is a document feeder mounted on a copying machine. It is a figure which shows the structure of. In FIG. 1, reference numeral 1 denotes a copying machine main body, and a slip glass (reading position) 2 and a contact glass 3 are provided on the upper surface of the copying machine 1.

Below the slit glass 2 and the contact glass 3, an exposure lamp 4 as image reading means and a first lamp are provided.
A mirror 5 and the like are provided, and the exposure lamp 4 and the first
The mirror 5 moves in the left-right direction in FIG. 1 below the contact glass 3 when reading the document placed on the contact glass 3, and when the document is read on the slit glass 2, the mirror 5 has a slit. It stops below the glass 2 and the surface of the original is exposed by the exposure lamp 4, and the reflected light thereof is CC through the first mirror 5 and a lens (not shown) as is known.
The image is read by being irradiated on D.

A document feeder (hereinafter, simply referred to as ADF) 6 is mounted on the upper portion of the copying machine main body 1 so as to be openable and closable with respect to the copying machine main body 1. On the lower surface of the ADF 6, a document placed on the contact glass 3 is pressed against the contact glass 3 and a reflector 7 is used as a white reference when reading the document.
Is provided. Further, a document placing table 8 is provided on the upper part of the ADF 6, and a document stack P made up of a plurality of documents is placed on the document placing table 8. The original bundle P placed on the original placing table 8 is moved by a calling roller 9 which can come into contact with and separate from the original bundle P,
The separation belt 10 and the separation roller 11 separate and feed.

A stopper member 12 is provided downstream of the calling roller 9 in the original conveying direction, and the original bundle P placed on the original placing table 8 is stopped by the stopper member 12 and enters the separation belt 10 side. It is prohibited. Below the calling roller 9, there is provided a pressure plate 13 which comes into contact with and separates from the calling roller 9 by means of a solenoid or the like (not shown). The call roller 9 is moved from a position separated from the call roller 9 to a position where the call roller 9 is brought into contact with the call roller 9, and the document is pressed against the call roller 9, and the document is fed by the call roller 9.

The separation belt 10 rotates in the direction indicated by the arrow V1 in the figure, and the separation roller 11 rotates in the clockwise direction. The separation belt 11 is moved to the uppermost position from the original bundle P fed by the calling roller 9. The document S located is separated.
That is, the separation belt 10 and the separation roller 11 constitute separation feeding means. The document separated and fed by the separation belt 10 and the separation roller 11 is sandwiched by a pair of conveyance rollers 14 composed of a conveyance driving roller 14a and a conveyance driven roller 14b and conveyed through a conveyance path 15. Reference numeral 15 is for reversing a document and feeding it to the slit glass 2. That is, the pair of transport rollers 14 constitutes a transport means. Further, the feed speed V1 of the separation belt 10 and the feed speed V2 of the transport roller pair 14 are set so that V1 <V2. Originally, V1 = V2 is desirable, but this is to prevent the slack of the originals or to prevent the originals fed back and forth from overlapping each other.

The transport path 15 has a curved curved surface for guiding the document separated and fed by the separation belt 10 and the separation roller 11 from the outside in the reversing direction and reversing it, and a first guide part 16. And a second guide portion that is provided to face the document and guides the document from the inside in the reverse direction. The second guide portion is formed so as to substantially coincide with a tangent plane that contacts the separation roller 11 and the conveyance roller 14a.

A reflection guide plate 18 serving as a white reference at the time of reading is provided on the upper portion of the slit glass 2, and a discharge driving roller 19 is provided downstream of the slit glass 2 in the original conveying direction.
There is provided a carry-out roller pair 19 including a and a carry-out driven roller 19b, and a carry-out roller pair 20 including a carry-out driving roller 21a and a carry-out driven roller 21b. The carry-out roller pair 19 and the carry-out roller pair 21 carry out a document whose image is read by the slit glass 2 onto the protective cover 22 through the carry-out path 20. The protective cover 22 constitutes a document discharge section and protects the ADF main body 6 portion on the contact glass 3.

A scale 23 is provided between the slit glass 2 and the contact glass 3, and when the original is placed on the contact glass 3 and an image is read, the end of the original is cut. When the image of the original conveyed on the slit glass 2 is read, which is the contact reference position, the original passing through the slit glass 2 is picked up and guided to the carry-out path 20.

The reflection plate 7 is attached to the lower part of the protective member 24, and the protective member 24 is rotatably provided on the ADF 6 main body via a fulcrum 25. Output frame 26 at fulcrum 25
Is rotatably provided, and the paper ejection frame 26 is provided with a paper ejection driven roller 21b and a fulcrum 27.
The carry-out driven roller holding member 28 is rotatably attached via the. The carry-out driven roller holding member 28 has a carry-out driven roller 19
b is attached.

Further, the holding member 24 and the carry-out driven roller holding member
It is connected to 28 by a link 29, and the carry-out driven roller holding member 28 comes into contact with and separates from the holding member 24 via the link 29. A magnet 30 is attached to the paper discharge frame 26, and the magnet 30 attracts the carry-out driven roller holding member 28. The carry-out driven roller holding member 28 may be entirely made of metal because it is attracted by the magnet 30, or may be made of plastic or the like and only the attracting portion may be made of metal.

With respect to the members on the contact glass 3, the delivery frame 26 is rotated upward via the fulcrum 25, so that the delivery driven roller 19b and the delivery driven roller 21 are rotated.
b is separated from the carry-out driving roller 19a and the paper discharge driving roller 21a to open the carry-out path 20 so that the jammed document on the carry-out path 20 can be removed. The protective cover 22 covers the paper discharge frame 26.

Next, the operation will be described. When a document stack P made up of a plurality of documents is placed on the document mounting table 8 and a copy start switch (not shown) is pressed, the pressure plate 13 presses the document stack P against the calling roller 9, whereby the calling roller 9 moves. The document stack P is moved toward the separation belt 10. The original S is separated and fed by the separating belt 10 and the separating roller 11, and is conveyed by the conveying roller pair 14 onto the slit glass 2 through the conveying path 15 and the slit glass 2 exposes the exposure lamp 4 and The image of the original is read by the image reading means such as the first mirror 5. The manuscript from which the image has been read is a pair of carry-out rollers 19 and a pair of carry-out rollers 21.
Is conveyed through the carry-out path 20 and discharged onto the protective cover 22.

As described above, the feeding speed V of the separation belt 10
1 and the feed speed V2 of the transport roller pair 14 are originally V1 = V2
However, in order to prevent the slack of the documents and to prevent the documents fed back and forth from overlapping, it is set so that V1 <V2. When the formed document S is sandwiched by the pair of transport rollers 14, the document is pulled upstream.
Further, the actual feed speed V1 ′ of the separation belt may be V1 ′ <V1 due to slip, and the document is more strongly pulled to the upstream side. As a result, as shown in FIG.
An attempt is made to form a tangential plane where the document contacts the separation roller 11 and the transportation roller 14a, that is, the shortest transportation path.

Therefore, in the conventional document feeding apparatus, the document is rubbed by the inner guide portion to increase the conveyance resistance, and the pair of the conveyance rollers and the document slip and the predetermined conveyance speed cannot be obtained. The read image is elongated, and the document is skewed (conveyance bending), resulting in defective reading. On the other hand, since the second guide portion 17 is formed so as to substantially coincide with the tangent plane that contacts the separation roller 11 and the conveyance roller 14a, the frictional resistance generated between the document and the second guide portion 17 is reduced. It can be significantly reduced. Therefore, the slip between the document and the pair of transport rollers 14 can be suppressed, and the document can be transported to the reading position at a stable speed by the pair of transport rollers 14. Therefore, it is possible to prevent the image from being stretched due to the slip between the document and the transport roller 14 and to prevent the document from skewing. Also,
It is possible to reduce the size, weight and cost of the device.

Further, as shown in FIG. 3, the second guide portion 17
It is preferable to provide a thin plate-shaped elastic member 31. The elastic member 31 is
One end is fixed to the 2 guide part near the separation roller 11,
The other end is provided at a predetermined angle with the second guide portion so that the first guide portion 16 approaches the transport roller 14b side.
As the elastic member 31, for example, a polyester film having a thickness of about 0.1 to 0.2 mm is suitable, but a steel plate may be used.

The elastic member 31, together with the first guide portion 16, forms a conveying path 15 which becomes narrower toward the downstream side, and the leading end of the document fed by the separating belt 10 and the separating roller 11 is smoothly conveyed by the conveying roller. Guide to pair 14. Therefore, it is possible to prevent the front end of the document from being folded and the tab from being folded. It is especially effective for documents with large curl. Further, when the document reaches the pair of transport rollers 14, as described above, the shortest transport path indicated by the imaginary line in the drawing is formed, so that the elastic member 31 is elastically deformed toward the second guide portion 17 side. The guide surface is substantially the same as the second guide portion. Therefore, the frictional resistance generated between the elastic member 31 and the document is significantly reduced, and
It is possible to obtain the same effect as that of the second guide portion 17 shown in FIG.

(Second Embodiment) FIG. 4 is a view showing a preferred embodiment of the document feeder according to the invention of claim 3 and is a cross-sectional view of the main part thereof. In this document feeder, the second guide portion 17 shown in FIG. 1 is replaced with a second guide portion 32. The same components as those of the document feeder shown in FIG. 1 are designated by the same reference numerals.

As shown in FIG. 4, the second guide portion 32 has a curved curved surface, one end of which is rotatably supported in the vicinity of the separation roller 11, and one end of which serves as a rotation shaft for the first guide side.
It is elastically supported by a spring 33 fixed to the main body of the ADF 6 so as to approach 16. The elastically supporting the second guide portion 32 is not limited to the spring, and may be rubber or sponge, for example.

The second guide portion 16 forms a conveying path 15 which becomes narrower toward the downstream side together with the first guide portion, so that the leading end of the document fed by the separating belt 10 and the separating roller 11 can be smoothly conveyed by the conveying roller. Guide to pair 14. Therefore, it is possible to prevent the front end of the document from being folded and the tab from being folded. It is especially effective for documents with large curl. When the document reaches the pair of transport rollers 14, the second guide portion 32 is urged rightward in the figure because the shortest transport path indicated by the imaginary line in the figure is formed as described above. Therefore, the frictional resistance generated between the second guide portion 33 and the document is significantly reduced, and the second guide portion shown in FIGS.
The same effect as 17 and the elastic member 31 can be obtained.

(Third Embodiment) FIGS. 5 to 6 are views showing a preferred embodiment of the document feeder according to the present invention. FIG. 5 is a cross-sectional view of the main part thereof, and this document transporting device is obtained by replacing the second guide part 17 shown in FIG. 1 with a second guide part 34. In addition,
The same components as those of the document feeder shown in FIG. 1 are designated by the same reference numerals.

As shown in FIGS. 5 and 6, the second guide portion 34 has a first central portion in the direction orthogonal to the document transport direction.
A protruding portion 35 having a curved curved surface protruding from the guide portion 16
a and projections 35a on both sides of the projection 34a and 0.5 to 2.0
Step portion 34 having a substantially constant step (y in FIG. 6) of about mm
b. In the opening 34c on the downstream side of the second guide portion 34, a pair of transport rollers 14 (only the transport roller 14a is shown)
Is provided.

The width direction of the second guide portion 34, which is orthogonal to the document conveying direction, is symmetrical, and the width of the protruding portion 34a is slightly longer than the width L of the conveying roller 14a on both sides thereof. (X in the figure). Further, the guide surface of the projecting portion 34a in the extending direction of the nip portion (document holding surface) of the transport roller pair 14 is configured to be substantially at the same level as the nip portion. Next, the operation will be described.

The document is fed to the pair of transport rollers 14 through the transport path 15 by the separation belt 10 and the separation roller 11. At this time, the guide surface of the projecting portion 34a in the extending direction of the nip portion (document holding surface) of the conveying roller pair 14 is configured to be at substantially the same level as the nip portion, so that the leading edge of the document is surely secured. Is guided to the nip portion of the transport roller pair 14. Therefore, it is possible to prevent the leading edge and the edge of the original from being broken. It is especially effective for documents with large curl.

When the document reaches the pair of transport rollers 14, as described above, it tries to form the shortest transport path and is transported along the second guide portion 34, but the second guide portion 34 has a stepped portion. Since the protruding portion 34a protruding from the protruding portion 34b is provided, only the protruding portion 34a is slidably contacted and conveyed.
Therefore, since the contact area between the document and the second guide portion 34 can be reduced to reduce the frictional resistance, the slip between the document and the pair of transport rollers 14 can be suppressed, and the document can be moved by the pair of transport rollers 14. It can be transported to the reading position at a stable speed. Therefore, it is possible to prevent the image from being stretched due to the slip between the document and the transport roller 14, and to prevent the document from skewing. Further, it is possible to realize the downsizing, weight reduction and cost reduction of the device.

Further, as shown in FIG. 6, a protrusion 35a formed of a curved curved surface in which the central portion in the direction orthogonal to the document conveying direction is protruded by the first guide portion 16 and both sides of the protrusion 34a. The second guide portion 35 may be composed of the first guide portion 16 and the inclined portion 35b that is inclined so as to be separated from each other on both sides. When the height of the curved surface of the protruding portion 34a is represented by h1 and the curved surfaces of both ends of the inclined portion are represented by h2, h1-h2 is 0.5.
It is about 2.0 mm. Even in this case, since the contact area between the document and the second guide portion 34 can be reduced to reduce the frictional resistance, slip between the document and the pair of transport rollers 14 can be suppressed, and the pair of transport rollers 14 can be used. The document can be conveyed to the reading position at a stable speed.

[0043]

According to the first aspect of the present invention, the document fed by the separating / feeding means is inverted by being guided by the first guide portion, and the shortest distance between the feeding means and the conveying means. The sheet is guided to the reading position by the conveying means while being guided by the second guide portion which is formed in a substantially flat shape and represents the document conveying path. For this reason, the frictional resistance generated between the document and the second guide portion can be remarkably reduced and the conveyance resistance of the conveying means can be reduced. Therefore, the conveying means is composed of a pair of rollers or a pair of rollers. It is possible to realize downsizing, weight reduction and cost reduction of the device.
Further, since the original can be conveyed to the reading position at a stable speed due to the reduction of the frictional resistance, it is possible to prevent the image from spreading due to the original slip and prevent the original from skewing.

According to the second aspect of the present invention, one end side of the second guide portion is fixed near the separating and feeding means of the second guide portion, and the other end side thereof is the conveying means of the first guide portion. Since the thin plate-like elastic member that is close to the side is provided, the elastic member forms a conveyance path that narrows toward the downstream side on the conveyance path together with the first guide portion, and the leading edge of the document that is fed by the separation feeding unit. Can be smoothly guided to the conveying means. Therefore, it is possible to prevent the front end of the document from being folded and the tab from being folded. This is particularly effective for a document with a large curl. Further, when the original reaches the conveying means, it is elastically deformed toward the second guide portion and the frictional resistance with the original is significantly reduced, so that the conveying resistance of the conveying means can be reduced.

According to the third aspect of the present invention, one end of the second guide portion is rotatably supported in the vicinity of the separating and feeding means, and the one end of the second guide portion is the first guide side. Since it is elastically supported so as to approach the conveyance path, a conveyance path that narrows toward the downstream side on the conveyance path is formed together with the first guide portion, and the leading edge of the document fed by the separation feeding means is smoothly guided to the conveyance means. can do. Therefore, it is possible to prevent the leading edge and the edge of the original from being broken.
It is especially effective for documents with large curl. Further, when the original reaches the conveying means, the second guide portion is elastically deformed inward in the reverse direction of the original and the frictional resistance with the original can be remarkably reduced. It is possible to realize the miniaturization, weight reduction and cost reduction of the device.
Furthermore, since the original can be conveyed to the reading position at a stable speed due to the reduction of the frictional resistance, it is possible to prevent the image from being stretched due to the original slip and prevent the original from skewing.

According to the fourth aspect of the invention, the document fed by the separating and feeding means is guided by the first guide portion and the second guide portion to be inverted, and is brought into sliding contact with the protruding portion of the second guide portion. And is conveyed to the reading position by the conveying means. For this reason,
Since it is possible to convey the original document while significantly reducing the frictional resistance generated between the original document and the second guide portion, the conveying unit can be configured by a pair of rollers, a pair of rollers, and the like, and the apparatus can be downsized. It is possible to realize weight reduction and cost reduction. Moreover, since the original can be conveyed to the reading position at a stable speed due to the reduction of the frictional resistance,
It is possible to prevent the extension of the image due to the slip of the document. Further, since the projecting portion in the vicinity of the conveying means is substantially aligned with the conveying path passing through the conveying means, even if the original has a large curl, the leading end of the original is smoothly conveyed by the conveying means. Can be guided to. Therefore,
It is possible to prevent the front end of the document from being broken and the tab from being broken.

According to the fifth aspect of the present invention, the second guide portion has a step portion formed of a curved surface on both sides of the projecting portion that forms a substantially constant step with the projecting portion. Therefore, the frictional resistance in the direction orthogonal to the document transport direction, that is, in the document width direction can be made uniform on the left and right, and the document skew can be prevented. According to the invention as set forth in claim 6, the second guide portion is provided on both sides of the projecting portion with inclined portions formed of curved surfaces that are inclined so as to be separated from the first guide portion as they are separated from each other on both sides. Therefore, the frictional resistance in the direction orthogonal to the document conveyance direction, that is, the width direction of the document can be made uniform on the left and right, and the skew of the document can be prevented.

[Brief description of drawings]

FIG. 1 is a main-portion cross-sectional view showing the configuration of a document feeder according to a first embodiment of the present invention.

[Fig. 2] The original conveyed by the conveying roller pair 14 is a separation roller.
FIG. 11 is a diagram showing an operation for forming a shortest transport path composed of a tangent plane that is in contact with 11 and the transport roller 14a.

FIG. 3 is a main-portion cross-sectional view showing a modified example of the first embodiment of the present invention.

FIG. 4 is a cross-sectional view of essential parts showing the configuration of a document feeder according to a second embodiment of the present invention.

FIG. 5 is a cross-sectional view of essential parts showing the configuration of a document feeder according to a third embodiment of the present invention.

6A and 6B are diagrams showing a main part of the document feeding device shown in FIG. 5, FIG. 6A being a perspective view thereof, and FIG. 6B being a sectional view passing through a nip portion of the feeding roller pair 14. Is.

7A and 7B are views showing a modified example of the document feeder according to the third embodiment of the present invention, FIG. 7A is a perspective view thereof, and FIG. 7B is a nip of the feed roller pair 14. It is sectional drawing which passes along a part.

[Explanation of symbols]

 1 Copier 2 Slit Glass (Reading Position) 4 Exposure Lamp 5 First Mirror 6 ADF (Document Feeding Device) 8 Document Placement Table 10 Separation Belt (Separation Feeding Means) 11 Separation Rollers (Separation Feeding Means) 14 Conveyance Roller Pairs (Conveying means) 15 Conveying path 16 First guide portion 17, 32, 34, 35 Second guide portion 31 Elastic member 33 Spring 34a, 35a Projecting portion 34b Step portion 35b Inclined portion

Claims (6)

[Claims] 1. A separating / feeding means for separating and feeding a plurality of originals one by one, and the originals fed by the separating / feeding means are turned upside down and conveyed to a predetermined reading position. In a document transporting device having a transporting path, a first guide part for guiding the document fed by the separating and feeding means from the outside in the reversing direction to invert the document to form the transporting path, and the first guide part. A second guide portion that is provided so as to face the sheet and that guides the document fed by the separation feeding unit from the inside in the reverse direction to form the conveyance path; and a second guide portion that is provided on the conveyance path and that separates the sheet. Transporting means for transporting a document fed by the transporting means and passing through the transport path formed by the first and second guide portions to the reading position, the second guide portion and the transporting means. Shortest document transport between the transport means A document transporting device, which is formed in a substantially flat shape representing a feeding path. 2. A thin plate-like elastic member having one end side fixed to the second guide part near the separating and feeding means of the second guide part, and the other end side close to the conveying means side of the first guide part. The document feeder according to claim 1, further comprising a member. 3. A separation feeding means for separating and feeding a plurality of originals one by one, and the originals fed by the separation feeding means are turned upside down and conveyed to a predetermined reading position. In a document transporting device having a transporting path, a first guide portion forming a transporting path is formed of a curved curved surface that guides the document fed by the separating and feeding unit from the outside in the reversing direction and inverts the document. A second curved surface that is provided so as to face the first guide portion and that guides the document fed by the separation feeding unit from the inside in the reversing direction, and that forms the conveyance path.
A guide unit, and a conveyance unit that is provided on the conveyance path and that conveys a document fed by the separation feeding unit and passing through the conveyance path formed by the first and second guide units to the reading position; The second guide portion has one end side rotatably supported near the separating and feeding means, and is elastically supported so as to approach the first guide side with the one end side as a rotation axis. Characteristic document feeder. 4. A separation feeding means for separating and feeding a plurality of originals one by one, and the originals fed by the separation feeding means are turned upside down and conveyed to a predetermined reading position. In a document transporting device having a transporting path, a first guide portion forming a transporting path is formed of a curved curved surface that guides the document fed by the separating and feeding unit from the outside in the reversing direction and inverts the document. A second guide portion that is provided so as to face the first guide portion and guides the document fed by the separating and feeding unit from the inside in the reverse direction to form the transport path; Transporting means for transporting a document, which is provided by the separating and feeding means and passes through the transport path formed by the first and second guide portions, to the reading position, wherein the second guide portion is provided. , Orthogonal to the document transport direction Has a protrusion formed of a curved curved surface with a central portion in the direction of the protrusion protruding toward the first guide portion, and the protrusion in the vicinity of the conveying means substantially coincides with the conveying path passing through the conveying means. A document feeder which is characterized in that. 5. The document feeder according to claim 4, wherein the second guide portion has stepped portions formed on both sides of the projecting portion and having a curved surface forming a substantially constant step with the projecting portion. 6. The second guide portion is provided on both sides of the protrusion,
5. The document feeder according to claim 4, further comprising an inclined portion formed of a curved surface that is inclined so as to be separated from the first guide portion as the distance from each side increases.