JPH09175745A - Circulating type document feeding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten a document feeding distance between a document supporting means and a transparent plate remarkably as compared with that in a conventional document feed device in a circulating type document feeding device in which a document layer is put on a document supporting means with the specified face of each document faced downward and from which the lowest document of the document layer is fed out. SOLUTION: The lowest document of a document layer put on a document supporting means 8 is fed to a first switchback path 26 through a document feed path 24, and its feeding direction is reversed so as to feed it onto a transparent plate 4 through a feed-in path 28. Then it is fed from the transparent plate 4 to a second switchback path 32 through a feed-out path 30, and its feeding direction is reversed so as to return it onto the document layer on the document supporting means 8 through a return path 34.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circulating type document feeder which is provided with a transparent plate and which is applied to an image forming machine such as a copying machine, a printing machine and a facsimile.

[0002]

2. Description of the Related Art U.S. Pat. No. 4,169,674 discloses
A circulation type document feeder is disclosed which is applied to an image forming machine provided with a transparent plate. Such a circulation type document feeder is a document support means arranged above a transparent plate of an image forming machine, and a carry-in path which extends sideways between the one end of the document support means and one end of the transparent plate and extends in a U-shape. And a carry-out path which extends sideways between the other end of the transparent plate and the other end of the document support means and extends in a U-shape, and a document transport means. The originals are stacked in the required order and placed on the original support means with the selected surface of each original facing upward. Therefore, in the stack of originals placed on the original supporting means, the first original is positioned at the top. The document conveying means sends the lowest document of the document stack placed on the document supporting means to the carry-in path, and carries it through the carry-in path (thus, inverting the front and back of the document) onto the transparent plate. Thus, the original is carried on the transparent plate with the selected surface (that is, the surface to be copied or read) of the original facing downward. When scanning exposure or scanning reading of the selected surface of the original is completed in the image forming machine, the original conveying means passes the original on the transparent plate through the carry-out path (thus, reversing the front and back of the original to restore the original state, The selected surface is returned to the upper side and is returned to the original stack on the original supporting means. By repeating such document transportation for the number of documents, copying or reading of one set of documents is completed.

Japanese Patent Publication No. 6-103407 also discloses a circulation type document feeder which is applied to an image forming machine provided with a transparent plate. This circulation type document feeder is provided with a document supporting means disposed above a transparent plate of an image forming machine, an additional conveying path extending between the document supporting means and the transparent plate, and one end of the document supporting means. And a delivery path extending in a U-shape laterally between the sheet and the upstream end of the additional transport path, and the downstream end of the additional transport path and one end of the transparent plate (an end located on the opposite side to the one end of the document support means). And a carry-in path that extends in a U-shape laterally, a carry-out path that extends from the other end of the transparent plate, a switchback path whose upstream end is connected to the downstream end of the carry-out path, and an upstream end of the switchback path. It has a return path extending from the upstream end connected to the one end to the above-mentioned one end of the document supporting means, and a document conveying means. The documents are stacked in the required order and placed on the document support means with the selected surface of each document facing downward.
Therefore, in the stack of originals placed on the original supporting means, the first original is located at the lowest position. The document transport means transports the lowest document of the stack of documents placed on the document support means to the additional transport path through the sending path (hence reverse of the front and back of the document) and then through the carry-in path (hence, the document Re-invert and return to the original state) and carry in as a transparent plate. Thus, the document is carried onto the transparent plate with the selected surface of the document facing downward. When the scanning exposure or scanning reading of the selected surface of the original is completed in the image forming machine, the original conveying means conveys the original on the transparent plate to the switchback path through the exit path, and then the original conveyed to the switchback path. , The conveyance direction is reversed, and the document is stacked on the document supporting means via the return path.

[0004]

Thus, in the circulation type document feeder disclosed in the above-mentioned US Pat. No. 4,169,674, the document stacking is performed with the selected surface facing upward. The following problems are caused by the fact that the lowermost original is sent out, in other words, the originals placed on the original supporting means are sequentially conveyed to the transparent plate from the final original toward the first original. There is. That is, the original is a so-called single-sided original in which an image is formed only on the selected surface, but when an image is formed on both sides of a copy or a printed matter, the original is temporarily exposed before scanning exposure or scanning reading of the original. It is necessary to sequentially convey the sheets, count the number of originals, and determine whether the number of originals is odd or even. If the number of originals is odd,
No image is formed on the back side of the first copy or printed matter, but an image corresponding to the image on the selected side of the lowest original of the original stack, that is, the final original is formed only on the front side of Images are sequentially formed on the back surface and the front surface of a copy or a printed matter. Even if the number of originals is an odd number, if images are formed on the back side and front side of the first copy or printed matter, no image exists on the front side of the final copy or printed matter. In this case, an inconvenience occurs that an image corresponding to the image of the first original is formed. The above-described counting operation of the number of originals lengthens the time required for the image forming processing operation, and also causes the original jam or the original damage because all the originals are additionally conveyed sequentially before the scanning exposure or scanning reading of the originals. The probability of doing is doubled.

On the other hand, in the circulation type document feeder disclosed in Japanese Patent Publication No. 6-103407, the lowest document of the document stack is sent with the selected surface facing downward. For example, since the originals placed on the original supporting means are sequentially carried in from the first original to the final original on the transparent plate, there is no problem as described above in the circulating original conveying apparatus. However, since the original is conveyed through the additional conveying path provided between the original supporting means and the transparent plate when the original is conveyed from the original supporting means onto the transparent plate, the length in the conveying direction of the original is small. Even if the document is relatively short, it is necessary to transport the document over a considerable distance before it is carried onto the transparent plate, and there is a problem that it takes a considerable time to transport the document. Further, since the required transport length is long, there is a high probability that a document jam will occur.

The present invention has been made in view of the above facts, and the main technical problem of the present invention is to stack originals on the original support means with the selected surfaces of the originals facing downward. Then, the lowest original of the original stack is sent out. (Therefore, the original is a single-sided original in which the image is formed only on the selected surface, but in the case of a copy or printed matter, the image is formed on both sides of the original. In this case, it is not necessary to count the number of originals before scanning exposure or scanning reading.) It is an object of the present invention to provide a new and improved recirculating document feeder which can be significantly shorter than the conventional document feeder.

Another technical problem of the present invention is that when an image is formed on both sides of a document, the document carried on the transparent plate with its one side facing downward is temporarily removed from the transparent plate. (EN) Provided is a new and improved recirculating document feeder, which can reverse the front and back sides of a conveyed sheet and re-convey the other side downward on a transparent plate.

[0008]

According to the present invention, in order to achieve the above-mentioned main technical problems, a circulation type document feeder is applied to an image forming machine provided with a transparent plate. A document supporting unit which is disposed above the transparent plate and has a stack of documents placed with the selected surface of each document facing downward.
A delivery path extending from one end of the document support means, a first switchback path whose upstream end is connected to the downstream end of the delivery path, and an upstream connected to the upstream end of the first switchback path. A carry-in path extending from one end to one end of the transparent plate, a carry-out path extending from the other end of the transparent plate, a second switchback path having an upstream end connected to a downstream end of the carry-out path, and the second And a return path extending from the upstream end connected to the upstream end of the switchback path to the other end of the original document supporting means, and the lowest original document of the original stack placed on the original document supporting means to the original document sending path. The document is sent out and conveyed to the first switchback path through the original document feed path, and then the original document conveyed to the first switchback path is reversed in the conveying direction and then passed through the carry-in path. To the transparent plate, and then from the transparent plate to the unloading path. The original conveyed to the second switchback path through the second switchback path is then reversed again in the conveying direction, and the original on the original document supporting means is returned through the return path. A document feeding device for returning the document onto the document stack is provided.

Further, in order to achieve the above-mentioned other technical problems, a re-carry-in passage extending between the intermediate portion of the return passage and the other end of the transparent plate is provided, and the second switchback is provided. The downstream part of the path and the downstream part of the return path are merged, and the document conveying means selectively conveys the document on the transparent plate to the second switchback route via the carry-out route. Then, the original conveyed into the second switchback path is conveyed again to the downstream portion of the return path by reversing the conveying direction, and thereafter, the conveying direction is further reversed and the original is conveyed again. It is re-loaded onto the transparent plate via the carry-in path, and is returned from the transparent plate onto the original stack on the original supporting means via the second switchback path.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A detailed description will be given below with reference to the accompanying drawings illustrating a preferred embodiment of a circulating type document feeder constructed according to the present invention.

An image forming machine, which may be an electrostatic copying machine, comprises a housing 2 (only the upper end portion of which is shown).
A glass transparent plate 4 extending substantially horizontally is disposed on the upper surface of the housing 2. The whole is shown by number 6,
The circulation type document feeder configured according to the present invention is disposed on the housing 2 of the image forming machine. The original document feeder 6 has a closed position (a position shown in FIG. 1) that covers the transparent plate 4 and an open position that exposes the transparent plate 4, with the pivot axis extending along the rear edge of the transparent plate 4 as the center. It is mounted on the housing 2 so as to be freely rotatable between them.

The document feeder 6 is provided with a document support means 8 located above the transparent plate 4. The original document supporting means 8 includes an original document supporting plate 10, and when the original document conveying device 6 is positioned at the illustrated closed position, the original document supporting plate 10 is spaced above the transparent plate 4 by the transparent plate 4. Extend substantially parallel to. More specifically, the downstream half (the left half in FIG. 1) of the document support plate 10 extends substantially parallel to the transparent plate 4 (and thus substantially horizontally).
The upstream half (the right half in FIG. 1) of 0 extends toward the right with a slight inclination upward. A leading edge regulating means 12 is arranged at the upstream end of the document supporting plate 10. The tip end regulating means 12 has a rotary shaft 14 extending in the front-rear direction (direction perpendicular to the paper surface in FIG. 1) and a regulating member 16 having an L-shaped cross section fixed to the rotary shaft 14 and having an appropriate shape. The regulating member 16 is slightly lowered from the lowered position in which the lower end edge of the regulating member 16 contacts the upper surface of the document supporting plate 10 by an operating means (not shown) which may be an electromagnetic solenoid connected to the rotary shaft 14 via a connecting mechanism. It is lifted and its lower end is slightly above the upper surface of the document support plate 10 (for example, 0.5 to 2.
It can be selectively positioned in the ascending position that is separated from it by about 0 mm. A width regulating means 18 is also arranged on the document supporting means 8. The width regulating means 18 includes a stationary regulating member (not shown) arranged at the rear end of the document supporting plate 10 and a movable regulating member 20 arranged at the front part of the document supporting plate 10. . The movable restricting member 20 is mounted so as to be movable in the front-rear direction, and is manually moved in the front-rear direction according to the width of a document placed on the document supporting plate 10, so that the stationary restricting member and the movable restricting member 20 can be moved. The space between and corresponds to the width of the document. The stationary regulating member and the movable regulating member 20 are provided with a separating member (not shown) that is selectively brought to an operating position that projects inward in the width direction. As will be further referred to later, the separating member is biased to the above-mentioned working position after the document stack is placed on the document support plate 10 and projected onto the document stack, and after being conveyed from the document stack onto the transparent plate. The original returned on the original support plate 10 is positioned above the separating means in the above-mentioned operating position. A trailing edge regulating means 22 is arranged at the downstream portion of the document supporting plate 10.
The trailing edge regulating means 22 is composed of a regulating member that is arranged so as to be movable in the document conveying direction (left-right direction in FIG. 1), and the length of the document placed on the document supporting plate 10 in the conveying direction. Accordingly, the distance between the regulation member 16 of the leading edge regulation means 12 and the regulation member of the trailing edge regulation means 22 is made to correspond to the length of the document in the conveyance direction. Since the configuration of the document supporting means 8 itself as described above is well known to those skilled in the art, the detailed description of the configuration of the document supporting means 8 itself will be omitted.

The illustrated document feeder 6 includes a document support means 8
And various transparent sheet conveying paths disposed between the transparent plate 4 and the transparent plate 4, that is, the sending path 24, the first switchback path 26, and the carry-in path 2.
8, a carry-out path 30, a second switchback path 32, a return path 34, and a re-carry-in path 36. The carry-out path 24 is
One end of the document supporting means 8, that is, the upstream end (the right end in FIG. 1)
From which it extends substantially horizontally to the right in FIG. The first switchback path 26 extends sideways from the upstream end connected to the downstream end of the carry-out path 24 in a U-shape. The carry-in path 28 extends from the upstream end connected to the upstream end of the first switchback path 26 to one end of the transparent plate 4 (right end in FIG. 1) in a substantially S-shape. The carry-out path 30 extends substantially horizontally to the left from the other end (the left end in FIG. 1) of the transparent plate 4. The second switchback path 32 extends from the upstream end connected to the downstream end of the carry-out path 30 to the other end of the document supporting means 8, that is, the downstream end (left end in FIG. 1) and extends in a substantially U-shape. There is. The return path 34 is the second switchback path 32.
From the upstream end connected to the upstream end of the document support means 8 toward the other end, that is, the downstream end. The downstream part of the second switchback path 32 and the downstream part of the return path 34 are joined together, and are defined by a common path 38. The re-carry-in path 36 extends between the intermediate portion of the return path 34 and the other end of the transparent plate 4.

The outside of the delivery passage 24 and the outside of the first switchback passage 26 are defined by a guide plate 40 extending continuously. The inside of the delivery path 24 and the inside of the carry-in path 28 are defined by a guide plate 42 that extends continuously. The inside of the first switchback path 26 and the outside of the carry-in path 28 are defined by a continuously extending guide plate 44. On the lower side or outside of the carry-out path 30, a plurality of plate-like members 46 (only one of which is shown in FIG. 1) arranged at intervals in the width direction (direction perpendicular to the paper surface in FIG. 1). ) Is defined by the upper edge, and the inside or upper side of the carry-out path 30 is provided with a plurality of plate-shaped members 48 (only one of which is shown in FIG. 1) arranged at intervals in the width direction. Defined by the bottom edge of the The outer side of the upstream portion of the second switchback path 32 has a plurality of plate-shaped portions 52 (of which a plurality of plate-shaped portions 52 are formed at intervals in the width direction on the upper edge of the plate-shaped member 46 and the inner surface of the cover member 50. (Only one is shown in FIG. 1) and the outside of the middle and downstream portions of the second switchback passage 32 (and thus the common passage 38) is widthwise to the inner surface of the cover member 54. It is defined by the inner edges of a plurality of plate-like portions 56 (only one of which is shown in FIG. 1) formed at regular intervals. The upstream side and the middle side of the return path 34 and the inside of the second switchback path 32 are defined by continuously extending guide plates 58. The outer side of the downstream portion of the return passage 34 (and thus the common passage 38) is defined by the inner edge of the plate portion 56. The inside of the upstream end of the return path 34 is defined by the left edge of the plate-shaped member 48, and the outside or lower side of the re-conveyance path 36 is defined by the upper edge of the plate-shaped member 48. The inside of the re-conveyance path 36, that is, the upper side and the inside of the intermediate portion of the return path 34 are defined by a continuously extending guide plate 60.

Three switching members 62, 64 and 66 are arranged inside or below the common path 38 (and thus the downstream part of the second switchback path 32 and the downstream part of the return path 34). Each of the switching members 62, 64 and 66 is provided with an actuating means, which may be an electromagnetic solenoid, and when the actuating means is deenergized, each of the switching members 62, 64 and 66 is in a non-acting position shown by a solid line. Of the switching members 62, 64 and 6 when the actuating means is biased.
Each of 6 is moved to the operating position indicated by the chain double-dashed line. As will be further referred to later, when the switching member 62 is positioned in the operative position indicated by the chain double-dashed line, the document conveyed to the common path 38 (and thus conveyed to the return path 34 or the second switchback path 32) is On the upstream side (the left side in FIG. 1) of the switching member 62, the switching member 62 is guided downward by the guiding action of the switching member 62 and returned onto the document support plate 10. When the switching member 62 is positioned at the non-acting position shown by the solid line and the switching member 64 is positioned at the working position shown by the chain double-dashed line, the document conveyed to the common path 38 passes through the switching member 62 and is switched. On the upstream side of the member 64, it is guided downward by the guiding action of the switching member 64 and returned onto the document support plate 10. When the switching members 62 and 64 are positioned at the non-acting position indicated by the solid line and the switching member 66 is positioned at the actuation position indicated by the two-dot chain line, the document conveyed to the common path 38 moves through the switching members 62 and 64. It passes and is guided downward by the guiding action of the switching member 66 on the upstream side of the switching member 66 and returned onto the document support plate 10. When all of the switching members 62, 64 and 66 are positioned at the non-acting position shown by the solid line, the document conveyed to the common path 38 passes through the switching members 62, 64 and 66 and passes through the common path 38.
The document is returned to the original support plate 10 from the downstream end (right end in FIG. 1).

A transport restricting piece 68 is arranged in the connection region of the downstream end of the delivery path 24, the upstream end of the first switchback path 26, and the upstream end of the carry-in path 28. This transportation regulation piece 6
The reference numeral 8 is a flexible member that projects upward from a base portion fixed to the guide plate 42 and has a free end contacting the guide plate 40. The document conveyed through the delivery path 24 enters the first switchback path 26 by bending the free end portion of the conveyance restriction piece 68 to the right in FIG. As will be further referred to later, when the conveyance direction of the document conveyed in the first switchback path 26 is reversed, the document is guided by the conveyance restricting piece 68 and introduced into the carry-in path 28. In the connection region of the downstream end of the carry-out path 30, the upstream end of the second switchback path 32, and the upstream end of the return path 34, the transport restriction piece 7 is provided.
0 is provided. The transport restricting piece 70 is formed of a flexible member that projects downward from a base portion fixed to the left edge of the plate member 48 and has a free end in contact with the upper edge of the plate member 46. A document conveyed through the carry-out path 30 enters the second switchback path 32 with the free end portion of the conveyance restricting piece 70 bent to the left in FIG.
As will be further referred to later, when the conveyance direction of the document conveyed in the second switchback path 32 is reversed, the document is guided by the conveyance restricting piece 70 and introduced into the return path 34.
Further, a transport restricting piece 72 is arranged in a connecting region between the intermediate portion of the return path 34 and the upstream end of the re-carrying path 36. The transport restricting piece 72 is formed of a flexible member that protrudes leftward from a base portion fixed to the upper edge of the plate member 48 and is brought into contact with the guide plate 58. The document conveyed through the return path 34 advances to the downstream side of the return path 34 by bending the free end of the conveyance restricting member 72 upward. As will be further referred to later, when the transport direction of the document transported to the downstream portion of the return path 34 is reversed, the document is guided by the transport restriction piece 72 and introduced into the re-transport path 36. The transport restraints 68, 70 and 72 can be conveniently formed from a synthetic resin film such as a polyethylene terephthalate film.

Continuing the description with reference to FIG. 1, the document conveying device 6 is also provided with a document conveying means. This document conveying means includes a document sending means 74. The document sending means 74 has a driven shaft 76 and a driven shaft 78 that are rotatably mounted at intervals in the carrying direction (the left-right direction in FIG. 1). A plurality of driven belt wheels 80 (only one of which is shown in FIG. 1) are fixed to the driven shaft 76 at intervals in the width direction (direction perpendicular to the paper surface in FIG. 1). A plurality of driven belt wheels 82 (only one of which is shown in FIG. 1) corresponding to the driven belt wheel 80 are fixed to the driven shaft 78. Then, the driven belt wheel 80 and the driven belt wheel 82
An endless belt 84 is wound around each pair of. The upper running portion of each of the endless belts 84 has the above-described original supporting plate 10
It is exposed upward through the opening formed in. Further, each of the endless belts 84 is formed with a large number of suction openings (not shown), and the suction openings are suction ducts (not shown) arranged inside the upper traveling portion of the endless belt 84. ) Through a suction source (not shown). As will be further referred to later, when the lowermost document of the document stack placed on the document support plate 10 is delivered to the delivery path 24, the suction source is energized and the endless belt 84 is moved by the arrow 86. It is driven to rotate in the direction shown, and thus the lowest document of the document stack is sucked by the upper running portion of the endless belt 84 and moved in the direction shown by the arrow 86, and is delivered to the delivery path 24. An air injection passage 88 is arranged above the downstream end (right end in FIG. 1) of the endless belt 84. The air jetting path 88 is connected to a blower (not shown) via a jetting duct 90, and when sending the lowest document of the document stack, the front end of the document stack on the document support plate 10 is sent. Air is ejected toward the front end of the lowermost original so that the leading edge of the lowermost original is separated from the original above it. The document sending means 74 and the air jetting path 88 attached to the document sending means 74 themselves may be in a form known to those skilled in the art, and therefore detailed description of these configurations will be omitted in the present specification.

The document conveying means also includes a conveying belt mechanism 92 arranged above the transparent plate 4. The conveyor belt mechanism 92 has a driven shaft 94 and a driven shaft 96 which are arranged at intervals in the conveying direction (the left-right direction in FIG. 1). A driven belt wheel 98 is fixed to the driven shaft 94, and a driven belt wheel 100 is fixed to the driven shaft 96. Then, the driven belt wheel 98 and the driven belt wheel 10
An endless belt 102 is wound around 0. The transport belt mechanism 92 is further provided with a plurality of pressing rollers 104. These pressing rollers 104 are elastically biased downward and press the lower running portion of the endless belt 102 against the upper surface of the transparent plate 4. The document conveying means is further
Conveyor roller pairs 106, 108, 110, 112, 11
4, 116, 118, 120, 122, 124. The transport belt mechanism 92 and the transport roller pair 106,
108, 110, 112, 114, 116, 118, 1
Since 20, 122, and 124 themselves may be of a well-known form, detailed description of these configurations will be omitted here.

Referring to FIG. 2 together with FIG. 1, in the document conveying means of the illustrated embodiment, the document feeding means 74 and the conveying roller pairs 106 and 108 are connected to a common electric motor 126. An electromagnetic clutch 127 is interposed between the document feeding means 74, the pair of conveying rollers 106, and the electric motor 126. The electric motor 12 in which the conveyance roller pair 110 and the conveyance belt mechanism 92 are common
8 and the conveying roller pairs 112, 114 and 124 are connected to a common electric motor 130, and the conveying roller pairs 116, 118, 120 and 122 are connected to a common electric motor 132. Continuing the description with reference to FIG. 1 and FIG. 2, the document detector 134 is disposed at the upstream end of the first switchback path 26 (that is, the upstream side of the conveying roller pair 108), and is located downstream of the carry-in path 28. The document detector 136 is provided at the end (that is, the downstream side of the pair of conveying rollers 110).
Is provided, and the document detector 138 is provided at the upstream end of the second switchback path 32 (that is, the upstream side of the conveyance roller pair 112).
Is provided, and the intermediate portion of the return path 34 (that is, the transport roller pair 1
A document detector 140 is provided on the upstream side of 24, and a document detector 142 is provided on the upstream end of the common path 38 (that is, the upstream side of the conveying roller pair 116). These document detectors 134, 136, 138, 140 and 142
Can be composed of an appropriate sensor such as a reflection type optical sensor. Further, the original support plate 10 has a movable restricting member 2
A plurality of detectors (not shown) for detecting the position of 0 in the width direction are arranged at appropriate intervals in the width direction. In the illustrated embodiment, the JIS standard is B5,
Documents A4, B4 and A3 are placed on the document support plate 10 in a so-called horizontal arrangement, that is, with the longitudinal direction thereof aligned with the width direction of the document support plate 10 (the direction perpendicular to the paper surface in FIG. 1). . Therefore, the size of the document can be recognized by detecting the position of the movable restricting member 20 and detecting the length in the direction perpendicular to the document conveyance direction. When it is necessary to detect the length of the document in the conveying direction in order to recognize the size of the document, for example, from when the document detector 134 detects the leading edge of the document to when it detects the trailing edge of the document. By detecting the time (which can be detected by the time measuring means built in the control means 144 which can be constituted by a microprocessor), the length of the original in the conveying direction can be detected. it can.

Next, the manner of document transportation by the document transportation device 6 as described above will be described. First, a description will be given of a case where scanning exposure or scanning reading is performed on only one side of each of a plurality of originals. In such a case, a plurality of originals are stacked in a required order (that is, page order), and The document stack is placed on the document support plate 10 of the document support means 8 with one side facing downward. At this time, the leading edge of the original stack is brought into contact with or brought close to the restricting member 16 located at the lowered position, and the trailing edge of the original stack is brought into contact with the stationary restricting member (not shown) of the width restricting means 18. Contact or approach. Then, the movable restricting member 20 of the width restricting means 18 is moved in the width direction to be brought into contact with or close to the front edge of the original stack, and the restricting member of the trailing end restricting means 22 is moved in the transport direction (left and right direction in FIG. 1). At the very least, it should be brought into contact with or close to the trailing edge of the original stack. When the movable restricting member 20 of the width restricting means 18 is moved to a required position corresponding to the width of the stack of originals, by detecting the position in the width direction of the movable restricting member 20 as described above, the original is B5, A4 in the JIS standard. , B4 and A
Which of the three is detected.

When the stacking operation of the original stack is completed as described above, it is arranged on the operation panel (not shown) of the image forming machine (or on the operation panel of the original conveying device 6 itself). The operation start switch is pressed to start document transportation. Referring to FIGS. 3 and 5 together with FIGS. 1 and 2, pressing the operation start switch starts the document loading process shown in FIG. 5, and in step n-1, the regulation member of the leading edge regulation means 12 is started. 16
Is moved to the raised position so that the lowest document in the document stack can be sent out, and a separation member (not shown) disposed on the stationary restriction member and the movable restriction member 20 of the width restriction unit 18 ) Is projected above the original stack, and a suction source (not shown) is also urged to communicate with a large number of openings formed in the endless belt 84 of the original sending means 74. The lowest document is sucked by the endless belt 84, a blower (not shown) is energized, and air is jetted from the air jetting passage 88 toward the front end of the document stack. Next, in step n-2, the normal rotation of the electric motor 126 is started, and at the same time, the electric motor 126, the document sending means 74, and the conveying roller pair 10 are started.
6, an electromagnetic clutch 127 interposed between the electric motor 126 and the electric motor 126 is drivingly connected to the original feeding means 74 and the conveying roller pair 106, and thus the original feeding means 74, the conveying roller pair 106, and the conveying roller. Pair 108
Is rotated forward in the direction indicated by arrow 86. As a result, the lowest document is moved from the stack of documents on the document supporting means 8 in the direction indicated by the arrow 86, and is conveyed to the first switchback path 26 through the sending path 24. In step n-3, it is determined whether or not the document detector 134 which was once turned on by the passage of the leading edge of the document is turned off by the trailing edge of the document passing through the document detector 134. . When the document detector 134 returns to OFF, the process proceeds to step n-4, and the electromagnetic clutch 127 is moved.
Is deenergized and the document sending means 74 is detached from the electric motor 126. Therefore, the document sending means 74 and the conveyance roller pair 1
The rotation of 06 is stopped. Next, in step n-5, the reverse rotation of the electric motor 126 is started, and the conveying roller pair 108 is rotated in the direction indicated by the arrow 146. As a result, the conveyance direction of the document conveyed to the first switchback path 26 is reversed, and the document is conveyed from the first switchback path 26 to the carry-in path 28. Next, in step n-6, the counting means 148 built in the control means 144 starts counting. When the counting means 148 counts a predetermined number in step n-7, step n-8
Then, the reverse rotation of the electric motor 126 is stopped. Next, in step n-9, the electric motor 12
8 is rotated in the normal direction, and the conveyance roller pair 110 and the conveyance belt mechanism 92 are rotationally driven in the direction indicated by arrow 86. Before the counting unit 148 counts the predetermined number and the rotational driving of the transport roller pair 110 and the transport belt mechanism 92 is started, the front end of the document transported to the carry-in path 28 is stopped. It reaches the nip and is brought into contact with it,
This corrects this if the document is slightly skewed. Then, the rotation drive of the pair of transport rollers 110 and the transport belt mechanism 92 is started, and the document is introduced onto the transparent plate 4 through the carry-in path 28. Step n above
At -9, when the forward rotation of the electric motor 128 is started, if the trailing edge of the original extends through the pair of conveying rollers 108 and the original detector 134 is ON, the electric motor 128 is turned forward. Simultaneously with the rotation, the electric motor 126 is rotated in the reverse direction, and when the trailing edge of the document passes through the document detector 134 and the document detector 134 returns to OFF, the reverse rotation of the electric motor 126 is stopped. In step n-10, it is determined whether or not the document detector 136 which was once turned on by the leading edge of the document has been turned off by the trailing edge of the document passing through the document detector 136. . When the document detector 136 returns to OFF, the process proceeds to step n-11, and the counting means 148 starts counting. Step n-1
When the counting means 148 counts a predetermined number in step 2, the process proceeds to step n-13 and the forward rotation of the electric motor 128 is stopped. The predetermined number counted by the counting unit 148 in step n-11 is determined according to the length of the document in the conveyance direction, the forward rotation of the electric motor 128 is stopped, and the conveyance roller pair 110 and the conveyance belt mechanism 92 are rotationally driven. When stopped, the document is positioned at the required position on the transparent plate 4.

When the document is positioned at the required position on the transparent plate 4 with the one side thereof facing downward as described above, the scanning optical system in the image forming machine 2 is moved by scanning, for example. One side of the document is scanned and exposed or scanned and read. When the scanning exposure or scanning reading is completed, a signal is supplied from the image forming machine 2 to the control means 144 of the document conveying device 6, and the document conveying device 6 discharges the document from the transparent plate 4 to support the document supporting means. The original carrying-out step of returning to 8 is started, and the original carrying-in step of the next original onto the transparent plate 4 is also started. For the next original, for example, when the previous original is carried from the first switchback path 26 through the carry-in path 28 onto the transparent plate 4, the trailing edge of the previous original is located at the original detector 134.
When the document detector 134 returns from ON to OFF after passing through the sheet, the conveyance of the next document (the lowest document in the document stack located on the document support plate 10) is started, and the one side of the previous document is removed. The pair of conveying rollers 110 in which the leading edge of the next document is stopped by the time scanning exposure or scanning reading is completed.
The next original can be conveyed to the position where it abuts against the nip.

Referring to FIG. 6 together with FIGS. 1 to 3, the document unloading step will be described. In step n-14, the electric motors 128, 130 and 132 start to rotate normally, and the conveyor belt mechanism 92 (and the conveyor rollers). Pair 110) and conveying roller pairs 112, 114, 124, 116, 1
18, 120 and 122 are rotationally driven in the direction indicated by arrow 86. Thus, the document on the transparent plate 4 is conveyed to the second switchback path 32 through the carry-out path 30. In step n-15, it is determined whether or not the document detector 138 that was once turned on by the leading edge of the document has been turned off by the trailing edge of the document passing through the document detector 138. . Document detector 138 is OFF
Then, the process proceeds to step n-16, and the electric motor 1
30 is switched from normal rotation to reverse rotation. by this,
The conveying roller pairs 112, 114, and 124 are rotationally driven in the direction indicated by the arrow 146, so that the conveying direction of the document conveyed to the second switchback path 32 is reversed, and the document is returned from the second switchback path 32. It is conveyed to the path 34. Then, it is returned to the document supporting means 8 through the return path 34. When the document has the JIS standard B5 size, all the switching members 62, 64, and 66 arranged in the downstream portion of the return path 34, that is, the common path 38 are positioned in the non-acting position indicated by the solid line, and thus The original document is conveyed to the downstream end of the common path 38, and is returned to the original stack existing on the original document support plate 10 with one side thereof facing downward. The manuscript is JIS
In the case of the standard A4 size, the switching members 62 and 64
Is located in the non-acting position shown by the solid line, but the switching member 66 is placed in the working position shown by the two-dot chain line, so that the document is moved downward from the upstream side of the switching member 66 and the one side is moved downward. The original stack is returned to the original stack existing on the original support plate 10. The manuscript is JIS standard B
In the case of four dimensions, the switching members 62 and 66 are placed in the non-acting position shown by the solid line, while the switching member 64 is placed in the working position shown by the chain double-dashed line, so that the document is upstream of the switching member 64. It is moved downward from the side and returned to the original stack existing on the original support plate 10 with one side thereof facing downward. When the document has the A3 size of JIS standard, the switching members 64 and 66 are located at the non-acting position shown by the solid line, but the switching member 62 is located at the working position shown by the chain double-dashed line. It is moved downward from the upstream side of the switching member 62 and returned to the original stack existing on the original support plate 10 with one side thereof facing downward. In step n-17, the document detector 14 is turned on once the leading edge of the document passes.
2 determines whether the trailing edge of the document has returned to OFF as the trailing edge of the document has passed the document detector 142. When the document detector 142 returns to OFF, the reverse rotation of the electric motor 130 is stopped in step n-18, and the counting means 148 starts counting in step n-19. Then, when the counting means 148 counts a predetermined number in step n-18, the process proceeds to step n-21 and the forward rotation of the electric motor 132 is stopped. The predetermined number counted by the counting means 148 in step n-20 is appropriately set according to the length of the document in the conveyance direction. The electric motor 128, which has started the normal rotation in step n-14, is stopped in the above-described step n-13 regarding the next document (if there is no next document to be conveyed, the above step n-).
At 16, the electric motor 128 can be stopped).

The document loading process and the document unloading process as described above are performed for each of a plurality of documents. When it is desired to perform scanning exposure or scanning reading a plurality of times for each of a plurality of documents, the document loading process and the document unloading process as described above may be subsequently performed.

Next, a case will be described in which scanning exposure or scanning reading is performed on both sides of each of a plurality of documents. Also in this case, as in the case of scanning and exposing or scanning and reading only one side of each original, a plurality of originals are stacked in a required order (that is, page order), and the selected one side (front surface) of each original is placed. The document supporting means 8 is placed downward on the document supporting plate 10. Then, the document carry-in step as described with reference to FIG. 5 is performed. After the original is loaded into the required position on the transparent plate 4 with the one side thereof facing downward,
When scanning exposure or scanning reading is completed in the image forming machine 2, a signal is supplied from the image forming machine 2 to the control means 144 of the document conveying device 6. Then, the document reversing process is started. Referring to FIGS. 4 and 7 together with FIGS. 1 and 2, in step n-22, the normal rotation of the electric motors 128, 130 and 132 is started, and the transport belt mechanism 92 (and the transport roller pair 110), And conveying roller pairs 112, 114, 124, 116, 118,
120 and 122 are rotationally driven in the direction indicated by arrow 86. Thus, the document on the transparent plate 4 is conveyed to the second switchback path 32 through the carry-out path 30. Step n-
At 23, it is determined whether or not the document detector 138 that was once turned on by the leading edge of the document passed back to the off state by the trailing edge of the document passing through the document detector 138. When the document detector 138 returns to OFF, the process proceeds to step n-24, the electric motor 128 is stopped, and the electric motors 130 and 132 are switched from the forward rotation to the reverse rotation. Therefore, the transport belt mechanism 92 (and the transport roller pair) is performed. 110) is stopped and the conveying roller pair 112, 1
14 and 124 are driven to rotate in the direction indicated by arrow 146, and the conveying roller pairs 116, 118, 120 and 12 are driven.
2 is rotationally driven in the direction indicated by arrow 146. Thus, the conveyance direction of the document conveyed to the second switchback path 32 is reversed, and the document is conveyed from the second switchback path 32 to the return path 34. Next, at step n-25, the document detector 142, which is once turned on by the leading edge of the document conveyed to the second switchback path 32, passing through the document detector 142,
It is judged whether or not the original has returned to OFF again by the conveyance direction being reversed and the original being conveyed (in the illustrated embodiment, the minimum length of the original in the conveyance direction is the original detector 1).
38 and the document detector 142). When the document detector 142 returns to OFF, the process proceeds to step n-26, the electric motor 132 is returned from the reverse rotation to the normal rotation,
Therefore, the conveying roller pairs 116, 118 and 120 are indicated by the arrow 8
It is driven to rotate in the direction indicated by 6. Next, in step n-27, it is determined whether or not the document detector 140 which was once turned on by the leading edge of the document has returned to OFF by the trailing edge of the document passing through the document detector 140. To be done. When the document detector 140 returns to OFF, the process proceeds to step n-28 and the electric motor 12
The reverse rotation of 8 is started, the electric motor 130 is switched from the reverse rotation to the forward rotation, and the electric motor 132 is switched from the forward rotation to the reverse rotation. As a result, the transport belt mechanism 92 (and the transport roller pair 110 are rotationally driven in the direction indicated by an arrow 146, and the transport roller pair 124 (and the transport roller pair 11
2 and 114) are driven to rotate in the direction indicated by the arrow 86, and the conveying roller pairs 116, 118, 120 and 12 are also driven.
2 is rotationally driven in the direction indicated by arrow 146. Therefore,
The original conveyed to the middle portion or the downstream portion of the return path 34 is conveyed in the reverse direction with the conveying direction reversed, and is conveyed to the re-introduction path 36, and is re-introduced into the transparent plate 4 through the re-conveyance path 36.
The original that is re-loaded into the transparent plate 4 from the other end (the left end in FIG. 1) has its front and back reversed, and the other side (back side)
Is re-loaded onto the transparent plate 4 with the side facing downward. In step n-29, it is determined whether or not the document detector 140, which was once turned on by the leading edge of the document, is turned off by the trailing edge of the document passing through the document detector 140. . Document detector 140 is off
Returning to step n-30, the process proceeds to step n-30 and counting means 148
Counting is started. When the counting means 148 counts a predetermined number in step n-31, the process proceeds to step n-32 to stop the rotation of the electric motors 128, 130 and 132. The predetermined number counted by the counting means 148 in step n-31 is set according to the length of the document in the conveyance direction. It is located in place.

As described above, when the document is positioned at the required position on the transparent plate 4 with the other surface facing downward, in the image forming machine 2, for example, the scanning optical system is moved by scanning. The other surface of the document is scanned and exposed or scanned and read. When the scanning exposure or scanning reading is completed, a signal is supplied from the image forming machine 2 to the control means 144 of the document conveying device 6, and the document conveying device 6 discharges the document from the transparent plate 4 to support the document supporting means. The original carrying-out step of returning to 8 is started, and the original carrying-in step of the next original onto the transparent plate 4 is also started. For the next original, for example, the conveyance of the next original is started at an appropriate point in the above-mentioned front-back reversing step of the previous original, and the scanning exposure or scanning reading of the other side of the previous original is completed, The next document can be transported to a position where the leading edge of the next document comes into contact with the nip of the pair of transport rollers 110 in which it is stopped.

Referring to FIG. 8 together with FIGS. 1 to 3, the document unloading step will be described. In step n-33, the electric motors 128, 130 and 132 are started to rotate normally, and the conveying belt mechanism 92 (and the conveying roller pair) is started. 110) and conveying roller pairs 112, 114, 124, 116, 1
18, 120 and 122 are rotationally driven in the direction indicated by arrow 86. Thus, the manuscript is in the second switchback path 3
It is returned to the document supporting means 8 through 2. Also in this case, if the original has a JIS standard B5 size, the return path 34
Of the switching member 6 disposed on the downstream portion of the
2, 64 and 66 are all located in the non-acting position shown by the solid line, and therefore the original document is conveyed to the downstream end of the common path 38 and is present on the original document support plate 10 with one side thereof facing downward. It is put back on the stack. When the document has the A4 size of JIS standard, the switching members 62 and 64 are located at the non-acting position shown by the solid line, but the switching member 66.
Is positioned at the operating position indicated by the chain double-dashed line, so that the document is moved downward from the upstream side of the switching member 66 and placed on the document stack existing on the document support plate 10 with one side thereof facing downward. Will be returned. When the document has the JIS standard B4 size, the switching members 62 and 66 are located at the non-acting position shown by the solid line, while the switching member 64 is located at the working position shown by the chain double-dashed line. It is moved downward from the upstream side of the switching member 64 and returned to the original stack existing on the original support plate 10 with one side thereof facing downward. When the document has the A3 size of JIS standard, the switching members 64 and 66 are located at the non-acting position shown by the solid line, but the switching member 62 is located at the working position shown by the chain double-dashed line. It is moved downward from the upstream side of the switching member 62 and returned to the original stack existing on the original support plate 10 with one side thereof facing downward. At step n-34, the document detector 142 which has been turned on once the leading edge of the document passes,
It is determined whether the trailing edge of the document has passed the document detector 142 and has returned to OFF. Document detector 142
When is turned off, the forward rotation of the electric motor 130 is stopped in step n-35, and the counting means 148 starts counting in step n-36. And step n
When the counting means 148 counts a predetermined number at -37,
Proceeding to step n-38, the normal rotation of the electric motor 132 is stopped. In step n-37, counting means 148
The predetermined number counted by is properly set according to the length of the document in the conveyance direction. The electric motor 128, which has started the normal rotation in the step n-33, is stopped in the above-described step n-13 regarding the next document (when there is no next document to be conveyed, the above step n-35 is performed). The electric motor 128 can be stopped at.

The document loading process, the document reversing process, and the document unloading process as described above are performed for each of a plurality of documents. When it is desired to perform scanning exposure or scanning reading for each of a plurality of originals a plurality of times, the original loading step, the original reversing step, and the original unloading step as described above may be further performed.

[0029]

In the circulation type document feeder constructed according to the present invention, the document stack is placed on the document support means with the selected surface of each document facing downward, and the document stack is placed at the lowest position. The original is a single-sided original in which the image is formed only on the selected surface.However, in copying or printed matter, even if images are formed on both sides, scanning exposure or scanning It is not necessary to count the number of documents before scanning.) However, especially when the length of the document in the document transport direction is comparatively short, the document transport distance from the document support means to the transparent plate is smaller than that of the conventional document transport device. It can be shortened significantly.

[Brief description of the drawings]

FIG. 1 is a sectional view schematically illustrating a preferred embodiment of a document feeder configured according to the present invention.

FIG. 2 is a block diagram schematically showing components for control arranged in the document feeder of FIG.

FIG. 3 is a simplified diagram schematically showing a manner of carrying a document when scanning and exposing or scanning and reading only one side of a document in the document feeder of FIG.

FIG. 4 is a simplified diagrammatic view schematically showing a document transportation mode in the case of scanning exposure or scanning reading on both sides of a document in the document transportation apparatus of FIG.

5 is a flow chart showing a document carrying-in step in the document transporting apparatus of FIG. 1 in the case where only one side of a document is subjected to scanning exposure or scanning reading.

FIG. 6 is a flowchart showing a document unloading process in the document feeder of FIG. 1 in the case where only one side of a document is scanned and exposed or scanned and read.

7 is a flowchart showing an original reversing step in the case of scanning exposure or scanning reading on both sides of an original in the original feeding apparatus of FIG.

8 is a flowchart showing a document unloading process in the document feeder of FIG. 1 in the case where both sides of a document are subjected to scanning exposure or scanning reading.

[Explanation of symbols]

 2: Housing of image forming machine 4: Transparent plate 6: Document transport device 8: Document support means 24: Delivery path 26: First switchback path 28: Carry-in path 30: Carry-out path 32: Second switchback path 34 : Return path 36: Re-loading path 38: Common path 74: Original feeding means (original conveying means) 92: Conveying belt mechanism (original conveying means) 106: Conveying roller pair (original conveying means) 108: Conveying roller pair (original conveying) Means) 110: Conveying roller pair (original conveying means) 112: Conveying roller pair (original conveying means) 114: Conveying roller pair (original conveying means) 116: Conveying roller pair (original conveying means) 118: Conveying roller pair (original conveying) Means) 120: Conveying roller pair (original conveying means) 122: Conveying roller pair (original conveying means) 124: Conveying roller pair (original conveying means)

Claims (2)

[Claims] 1. A circulation type document conveying device applied to an image forming machine having a transparent plate, wherein the document stacking device is arranged above the transparent plate, and the document stack is located below a selected surface of each document. A document supporting means to be placed toward the user, a delivery path extending from one end of the document supporting means, a first switchback path having an upstream end connected to a downstream end of the delivery path, and a first switchback path. A carry-in path extending from an upstream end connected to the upstream end of the switchback path to one end of the transparent plate; a carry-out path extending from the other end of the transparent plate; and an upstream end connected to a downstream end of the carry-out path. A second switchback path, a return path extending from an upstream end connected to an upstream end of the second switchback path to the other end of the document support means, and a return path mounted on the document support means. The lowest original of the original stack is sent to the original sending path, and the original is sent through the original sending path. The original conveyed to the first switchback path, then the original conveyed to the first switchback path is reversed in the conveying direction, and is conveyed onto the transparent plate via the conveyance path. Afterwards, the original conveyed to the second switchback path from above the transparent plate via the carry-out path, and then the original conveyed into the second switchback path is re-reversed in the conveying direction, and the return path is returned. An original conveying unit for returning to the original stack on the original supporting unit via a circulating original conveyer. 2. A re-carry-in path extending between an intermediate part of the return path and the other end of the transparent plate is provided, and a downstream part of the second switchback path and a downstream side of the return path. The original document conveying means selectively conveys the original document on the transparent plate to the second switchback path through the carry-out path, and then the second switch. The original conveyed in the back path is conveyed again to the downstream side of the return path by reversing the conveying direction, and then the conveying direction is further reversed, and the transparent plate is conveyed through the re-conveying path. 2. The circulating original conveying apparatus according to claim 1, wherein the original is conveyed again onto the transparent plate, and then returned onto the original stack on the original supporting means from the transparent plate via the second switchback path.