JP5740911B2 - Sheet conveying apparatus, automatic document conveying apparatus, image reading apparatus, and image forming apparatus - Google Patents

Description

  The present invention relates to a sheet conveying apparatus that separates and conveys sheets such as originals one by one, an automatic document conveying apparatus including the sheet conveying apparatus, an image reading apparatus, and an image forming apparatus.

  In the sheet transport device or automatic document transport device, the position of the front end of the document is regulated before the separation unit to prevent the paper from entering the separation unit when the user sets the document. A shutter mechanism that can be retracted in conjunction with is well known.

  In a shutter mechanism provided in a conventional sheet conveying device or automatic document conveying device, a method of operating a shutter member using a driving source such as a solenoid as a method of switching between a document restricting state and an unregulated state by a shutter member, a pickup holder There are methods for operating the shutter member in conjunction with each other, but each has the following disadvantages.

Method using a solenoid or the like: A drive source such as a solenoid is provided, the cost increases due to the control, and a space for arranging the solenoid is required.
Pickup holder interlocking method: When the document to be set is thick or when the user has a strong setting force, the lowering force of the pickup holder cannot cause the shutter member to operate (cancel the restriction), resulting in non-feeding.

  FIG. 17 is a diagram illustrating a configuration of a separation unit of an automatic document feeder that is not yet well-known by the applicant of the present application. In this configuration, since the fulcrum of the shutter 13 and the shutter restricting member (link) 14 is parallel, when the shutter restricting member 14 is rotated by the pickup holder 19, the rotation locus bites into the shutter. It was supposed to be. That is, when the shutter restricting member 14 is rotated, the shutter 13 must be moved in the direction in which the document is pushed back upstream (clockwise in the drawing). If it is strong, there is a problem that it cannot be rotated only by the torque of the torque limiter 21. In particular, when the apparatus is downsized, since the amount of movement of the pickup holder is small, the lever ratio of X and x must be increased, and the above problem has been a problem.

  Japanese Patent Laid-Open No. 2002-96935 (Patent Document 1) discloses a paper feeding device that can smoothly lower a pickup roller even when a paper is strongly pressed against a paper leading edge regulating member. It is disclosed.

  However, even in the configuration described in Patent Document 1, when the shutter restricting member is rotated by the pickup holder, the rotation locus becomes the biting side with respect to the shutter. The problem of shutter operation failure when the setting force is strong cannot be solved.

  The present invention solves the above-described problems in the conventional sheet conveying apparatus, can reduce the force to move the shutter member, and stably operates the shutter member without using a driving source such as a solenoid, thereby stably feeding the sheet. It is an object of the present invention to provide a sheet conveying apparatus capable of conveying, an automatic document conveying apparatus including the sheet conveying apparatus, and an image forming apparatus.

  According to the present invention, there is provided a sheet calling unit that calls a sheet set in a sheet setting unit, a sheet feeding unit, and a separation member. The sheets called by the sheet calling unit are separated one by one. A sheet conveying apparatus including a separating and feeding unit that feeds a sheet, and is provided so as to be rotatable between a restriction position that restricts the leading edge of a sheet set in the sheet setting part and a restriction release position that releases the restriction. And a shutter restricting member provided to be rotatable to a restriction position for restricting the rotation of the shutter member and a restriction release position not restricting the rotation in conjunction with the raising and lowering of the sheet calling means. And the rotation axis of the shutter member and the rotation axis of the shutter regulating member are provided non-parallel.

Further, it is preferable that the relative angle between the rotation axis of the shutter member and the rotation axis of the shutter restricting member is set to approximately 90 degrees.
Further, it is preferable that when the sheet is called by the sheet calling means, a holder member that holds the sheet calling means comes into contact with the shutter restricting member and moves the shutter restricting member from the restricting position to the restriction releasing position.

  The length from the rotation fulcrum of the shutter regulating member to the contact portion with the holder member is X, and the length from the rotation fulcrum of the shutter regulating member to the contact portion with the shutter member is Y. In this case, it is preferable that Y> X.

  Further, it is preferable that the movement amount of the shutter restricting member with respect to the movement amount of the holder member at the time of calling the sheet by the sheet calling means is provided so as to decrease from the middle of the movement of the holder member.

Further, it is preferable that the shutter member and the shutter regulating member are disposed between the sheet calling unit and the sheet feeding unit.
The shutter restricting member is located below the uppermost position of the holder member that holds the sheet calling means in both the restricting state that restricts the rotation of the shutter member and the unregulated state that does not restrict the rotation. It is preferable that it is provided.

  And a restricting portion holding member that rotatably holds the shutter member and the shutter restricting member, and the restricting portion holding member is rotatably held on the shaft of the sheet feeding unit. The restricting portion holding member has a protruding portion that extends on the opposite side of the shutter member and the shutter restricting member across the shaft of the sheet feeding means, and the protruding portion is a predetermined member of the apparatus main body. It is preferable that the position of the restricting portion holding member is maintained by contact.

Moreover, it is preferable that the predetermined member of the apparatus main body is an upper cover provided so as to be openable and closable.
The shaft of the sheet feeding means is preferably supported by the frame of the apparatus main body.

According to the present invention, the above problem is solved by an automatic document feeder provided with the sheet feeder according to any one of claims 1 to 10.
Further, according to the present invention, the above problem is solved by an image reading apparatus including the sheet conveying apparatus according to any one of claims 1 to 10 or the automatic document conveying apparatus according to claim 11.

  Further, according to the present invention, any of the sheet conveying device according to any one of claims 1 to 10, the automatic document conveying device according to claim 11, and the image reading device according to claim 12 according to the present invention. This is solved by an image forming apparatus including the above.

  According to the sheet conveying apparatus of the present invention, since the rotation shaft of the shutter member and the rotation shaft of the shutter restricting member are provided in non-parallel, the force required to rotate the shutter restricting member is reduced. Therefore, the shutter restricting member can be easily rotated, so that the holder member of the sheet calling means for rotating the shutter restricting member can be reduced, and the apparatus can be miniaturized.

  According to the configuration of the second aspect, when the shutter restricting member is rotated, the shutter is not rotated against the sheet (against the weight of the sheet), and is necessary for rotating the shutter restricting member. The force can be further reduced, and further downsizing of the apparatus can be realized.

  According to the configuration of the third aspect, since the shutter restricting member can be moved without using a drive source such as a solenoid, the cost can be reduced, and the arrangement space of the drive source is not required, and the apparatus can be downsized. Become.

According to the fourth aspect of the present invention, the amount of movement of the shutter restricting member relative to the amount of movement of the holder member can be increased, and the apparatus can be miniaturized.
According to the configuration of the fifth aspect, the total movement amount of the shutter restricting member can be reduced, and the apparatus can be miniaturized.

According to the configuration of the sixth aspect, it is possible to create the restricted state and the restricted state of the shutter member by utilizing the movement of the holder member that holds the sheet calling means.
According to the configuration of the seventh aspect, the shutter restricting member does not protrude above the holder member, and the apparatus can be downsized.

  According to the configuration of the eighth aspect, the posture of the restricting portion holding member can be maintained with a simple configuration, whereby the shutter member and the shutter restricting member can be maintained in an appropriate state.

According to the configuration of the ninth aspect, the posture of the restricting portion holding member can be maintained by the upper cover.
According to the structure of the tenth aspect, even when the upper cover is opened, the shutter member and the shutter restricting member can be rotated to the restricting position by raising the sheet calling means by rotating the shaft of the sheet feeding means. The original (sheet) can be reliably regulated.

According to the automatic document feeder of the eleventh aspect, the automatic document feeder can be miniaturized as the sheet feeder is miniaturized.
According to the image reading apparatus of the twelfth aspect, it is possible to reduce the size of the image reading apparatus as the sheet conveying apparatus or the automatic document conveying apparatus is reduced in size.

  According to the image forming apparatus of the thirteenth aspect, it is possible to reduce the size of the image forming apparatus as the sheet conveying apparatus, the automatic document conveying apparatus, or the image reading apparatus is miniaturized.

1 is a cross-sectional configuration diagram showing an example of an automatic document feeder provided with a sheet feeder according to the present invention. It is a perspective view which shows the original document control part in which an original shutter is arrange | positioned. FIG. 6 is a view showing a document restricting portion with the pickup roller 7 and its holder member hidden. 3 is an exploded perspective view of a document shutter portion. FIG. It is a front view shown in the state where the shutter and the shutter regulating member are attached to the shutter holder. It is sectional drawing which shows the structure of a document control part and its both sides. FIG. 7 is a view of the shutter and the shutter regulating member in a standby state as viewed from the document setting direction side (the right side in FIG. 6). It is the figure which looked at FIG. 7 from the side (left side). It is a perspective view of a shutter and a shutter regulating member in a standby state. It is the figure which looked at the pickup holder from the lower part. It is a side view which shows the mode of the paper feed part at the time of pick-up operation | movement. It is a front view which shows the state which the shutter control member rotated and the shutter became rotatable. It is the figure which looked at the shutter control part from the upper part. It is a front view which shows the mode of the shutter part at the time of pick-up operation | movement. It is a side view which shows the mode of the paper feed part at the time of pick-up operation | movement. FIG. 2 is a cross-sectional configuration diagram illustrating an example of an image forming apparatus to which the automatic document feeder of FIG. 1 can be attached. It is a figure which shows the structure of the separation part of the automatic document feeder which the applicant of this application applied previously.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a cross-sectional configuration diagram showing an example of an automatic document feeder provided with a sheet feeder according to the present invention. In this figure, an automatic document feeder 1 is attached to an upper part of an image reading apparatus 2 such as a scanner so as to be opened and closed. The image reading device 2 is provided with a slit glass (reading position) 3 on its upper surface, and the automatic document feeder 1 transports the document and passes the document over the slit glass 3 to read the document. A single-side mode and a double-side mode can be selected by an instruction from an operation unit (not shown), and the operation of the automatic document feeder 1 is controlled by the set mode. The user sets the document 6 on the document stacking table 5 in the page order with the image surface facing up.

  The document feeder in the automatic document feeder 1 of this embodiment includes a pickup roller 7 as a sheet calling unit, a feed roller 9 as a sheet feeding unit, a reverse roller 10 for separating sheets, and a document set detection unit 8. And a shutter mechanism or the like for preventing the paper from entering the separating portion when the user sets a document. In FIG. 1, the shutter mechanism is shown as a rod-like or plate-like shutter 100 in order to avoid the complexity of the drawing, but actually, the shutter mechanism has a configuration as described in FIG.

  Normally, the pickup roller 7 stands by at a predetermined interval from the document stacking table 5, and it is detected by the document stacking sensor 8 that a document is set on the document stacking table 5, and on an operation unit (not shown). When the start of reading is instructed, it is controlled so as to descend from the standby position and move to a position in contact with the upper surface of the document 6. In addition, a document shutter 100 is provided in the document placement section, and the rotation of the document shutter 100 is restricted when the pickup roller is raised (standby), and the restriction is released when the pickup is lowered (when reading is started). It is a mechanism that can rotate in the direction of the arrow. Therefore, the user can set the document so as to abut against the document shutter 100. The document shutter 100 is shifted in the document width direction so as not to interfere with the document detection filler member 8 of the document set detection means.

  The originals called by the pickup roller 7 are separated one by one from the top by a separating unit having a feed roller 9 and a reverse roller 10. The separating means may be a combination of the feed roller 9 and the separation pad.

  A conveyance path indicated by a symbol (A) is formed by the guides 11 and 11a, and is a path for conveying the document separated and conveyed by the feed roller of the separation unit onto the slit glass 3. A conveyance path (b) indicated by reference numeral (b) is formed by the guides 12 and 12 a and is a path for moving the document conveyed through the slit glass to the paper discharge port 13. Reference numeral 14 denotes a paper discharge tray for stacking the documents discharged from the document discharge port 13. The switchback conveyance path indicated by reference numeral (c) is formed between the guides 16 and 16a and 16a provided at the lower part of the document stacking table 5 and above the document tray 14, and the branching claws. This is for switching back the document discharged from the paper discharge port 13 and again guiding it from the rear end of the document to the transport path (A). The branching claw 17 is provided above the document tray 14, and by switching to the dotted line position, the document ejected from the ejection port 13 is guided to the switchback path (c), and the document is introduced into the switchback path (c). Then, by switching to the solid line position, the document switched back in the switchback conveyance path (c) is guided from the rear end to the conveyance path indicated by reference numeral (d). The conveyance path (d) is formed between the guides 18 and 18a, is joined with the conveyance path (a), and is a path for conveying the switched-back document to the reading position again. The reversing rollers 26 and 26a have means for switching between normal rotation and reverse rotation independently, and the document conveyed to the switchback conveyance path (c) is introduced into the switchback path (c) and then reversely rotated. Then, the document is conveyed to the conveyance path (d). Reference numeral 28 denotes a sensor disposed between the reading roller and the reading position, for adjusting the leading edge of the document conveyed by the reading roller and the reading start timing.

  FIG. 2 is a perspective view showing a document restricting portion on which the document shutter 100 is arranged. FIG. 3 is a view showing the document restricting portion with the pickup roller 7 and its holder member (pickup holder 103) hidden. In these drawings, reference numeral 7 is a pickup roller, reference numeral 9 is a feed roller, reference numeral 100 is a shutter, reference numeral 101 is a shutter restricting member, reference numeral 102 is a shutter holder for assembling the shutter 100 and the shutter restricting member 101, and reference numeral 104 is a feed roller 9. Reference numeral 105 denotes a torque limiter.

  The feed roller 9 is rotationally driven by transmitting a driving force from a motor (not shown) as a driving source to the feed roller shaft 104 via a driving system (not shown). The shutter holder 102 and the pickup holder 103 are held rotatably about the feed roller shaft 104. The shutter holder 102 is supported by the feed roller shaft 104 via a bearing, and the rotation of the shaft 104 is not transmitted. On the other hand, in the pickup holder 103, the rotation of the shaft 104 is transmitted to the pickup holder 103 through the torque limiter 105 by assembling the both-side torque limiter 105 supported by the holder on the feed roller shaft 104. Further, a drive train (not shown) for rotationally driving the pickup roller 7 is attached to the pickup holder 103, and the rotation of the shaft 104 is transmitted to the pickup roller 7 through the drive train. Has been.

  FIG. 4 is an exploded perspective view of the document shutter portion. The shutter holder 102 (regulating portion holding means) integrally includes a holding portion 102b that holds the shutter 100 and the shutter restricting member 101, and a positioning portion (protruding portion) 102a that is formed on the opposite side across the supporting portion 102b and the fulcrum. Have in. The shutter 100 has shafts 100b and 100b protruding from the left and right sides in the drawing (the right shaft is hidden), and the shutter restricting member 101 has shafts 101c and 101c protruding from the front and rear sides in the drawing. (The rear axis is hidden). The shafts 100b and 100b of the shutter 100 are fitted into the fitting holes 102d and 102d provided in the shutter holder 102, and the shafts 101c and 101c of the shutter regulating member 101 are fitted into the fitting holes 102e and 102e (rear side) provided in the shutter holder 102. The shutter 100 and the shutter regulating member 101 are held by the shutter holder 102.

  The rotation axis (axis 100b) of the shutter 100 and the rotation axis (axis 101c) of the shutter restricting member 101 are provided so as to be non-parallel, and in this embodiment, the rotation axes of the two have a relative angle. It is set to approximately 90 degrees (so that the extension lines of the rotation axis of the shutter 100 and the rotation axis of the shutter regulating member 101 are substantially orthogonal when viewed from vertically above).

  The shutter restricting member 101 is formed with a slope 101e that is pressed by a protrusion 103a (shown in FIG. 10) provided on the pickup holder 103 to rotate the shutter restricting member 101.

  FIG. 5 is a front view showing the shutter holder 102 with the shutter 100 and the shutter regulating member 101 attached thereto. The shutter restricting member 101 has a counterclockwise rotational force in FIG. 5 about the shaft 101c due to its own weight, but the position of the protrusion 101b hits the protrusion 102c of the shutter holder 102 to the position of FIG. Kept. In the present embodiment, by providing the weight portion 101d as shown in FIG. 4, the projection portion 101b surely abuts against the shutter holder 102 (the projection portion 102c) by the weight of the restriction portion 101a and the weight portion 101d. ing.

  FIG. 6 is a cross-sectional view showing the configuration of the document restricting portion and its both side portions, and shows the upper cover 112 that also serves as a conveyance guide and the paper feeding portion. In this embodiment, the feed roller shaft 104 is provided on the main body side of the automatic document feeder, and is not assembled to the upper cover 112. As described above, the shutter holder 102 is held so as to be rotatable with respect to the feed roller shaft 104. As can be seen from FIG. 4, the holder 102 b that holds the shutter 100 is larger and heavier than the positioning portion 102 a, and the shutter holder 102 is positioned in the clockwise direction in FIG. The portion 102a (protruding portion) hits the contact portion 112a of the upper cover 112, and the position of the shutter holder 102 is maintained (the posture of the shutter holder 102 is maintained).

  As described above, the pickup holder 103 is also held so as to be rotatable with respect to the shaft 104. The pickup holder 103 is configured such that the rotation of the feed roller shaft 104 is transmitted via the both-side torque limiter. After the reading operation is completed, the shaft 104 is rotated counterclockwise in the drawing to raise the pickup holder 103. The standby position of the pickup holder 103 is determined by abutting against the upper cover 112. At this time, the rotation amount of the shaft 104 is sufficient to allow the pickup holder 103 to abut against the upper cover 112. The shutter 100 is held by the shutter holder 102, and a rotational force acts counterclockwise in the figure by its own weight, but the rotation is restricted and the position is held by striking against the protrusion 102f provided on the shutter holder 102. .

  FIG. 7 is a view of the shutter 100 and the shutter regulating member 101 in the standby state as viewed from the document setting direction side (the right side in FIG. 6). 8 is a side view (left side) of FIG. 7, and FIG. 9 is a perspective view.

  It is assumed that the document 4 is set on the document placement table 3 so as to abut against the shutter 100 in this standby state. In this case, a force is applied to the shutter 100, and the shutter 100 tries to rotate clockwise in FIG. 8, but since the shutter restricting portion 101a of the shutter restricting member 101 is on the rotation locus of the projection portion 100a of the shutter, the shutter rotates. And the leading edge of the document can be regulated. Therefore, the document does not go downstream from the shutter 100, and it is possible to prevent a user from inserting a large number of documents into the separation unit.

  Further, as shown in FIG. 10, the pickup holder 103 is provided with a protrusion 103 a for rotating the shutter restricting member 101. In this standby state, the protrusion 103a and the shutter restricting member 101 are set so as not to contact each other.

  FIG. 11 is a side view showing the state of the paper feed unit during the pickup operation (full stacking). When a reading operation is instructed, the drive is transmitted from the drive source (motor) to the feed roller shaft 104 in the clockwise direction in the figure, and the pickup holder 103 rotates with a torque that is constantly regulated by the torque limiter 105. The roller 7 is pressed against the document. At this time, as shown in FIG. 12, the shutter regulating member 101 is rotated by the projection 103a of the pickup holder 103 (the inclined surface portion 101e), so that the shutter regulating member 101 is rotated and the shutter regulating member 101a is rotated by the projection 100a of the shutter. The shutter deviates from the locus and can be rotated.

  Further, the length X from the fulcrum (shaft) 101c of the shutter restricting member 101 to the contact portion between the protrusion 103a of the pickup holder and the restricting member 101, and the length Y from the fulcrum 101c to the shutter restricting portion 101a are Y. Since it is configured such that> X, the movement of the shutter restricting portion 101a can be increased even when the movement amount of the pickup holder 103 is small. Therefore, the movement amount of the pickup holder 103 can be reduced, and the machine height The size can be reduced.

FIG. 13 shows a view of the shutter restricting portion as viewed from above.
As shown in FIG. 13, the upper surface of the shutter holder 102 is partially cut away, and the inclined surface portion 101e of the shutter restricting member 101 is exposed in the cutout portion, so that the protrusion 103a of the pickup holder (this figure) (Not shown in the figure) enters the cut-out portion so as to come into contact with the shutter restricting member 101 and press the inclined surface portion 101e. Further, on the upper surface of the shutter holder 102, notched windows 102g and 102g are provided for allowing the shutter restricting portion 101a and the tip portions of the weight portion 101d to escape when the shutter restricting member 101 rotates.

FIG. 14 is a front view showing a state of the shutter portion during the pickup operation (at the time of the last single pickup).
The inclined surface portion 101e that contacts the protrusion 103a of the pickup holder of the shutter restricting member 101 is formed not in a straight line but in a curved shape that is bent in the middle when viewed from the axial direction of the rotation shaft 101c. The movement amount of the shutter restricting portion 101a with respect to the amount of movement of the pickup holder 103 is reduced from the middle (initially, the shutter restricting portion 101a moves greatly, but after that, the moving amount becomes smaller thereafter). As a result, the shutter restricting member 101 can be prevented from popping out above the pickup holder 103, and the apparatus can be downsized.

  FIG. 15 is a side view showing the state of the paper feed unit during the pick-up operation (during the last single pick-up). As shown in this figure, the shutter restricting member 101 does not protrude upward from the pickup holder 103. The shutter restricting member 101 is provided so as to be positioned below the uppermost position of the pickup holder 103 in both the restricting state in which the rotation of the shutter 100 is restricted and the restriction releasing state in which the turning is not restricted.

  In this embodiment, the paper feed unit including the document restricting unit is supported on the apparatus main body side, and the upper cover 112 can be opened for jam processing. Even when the user opens the upper cover 112, if the sensor (not shown) detects that the upper cover has been closed after that, the pickup roller 7 is raised so that the shutter 100 and the shutter regulating member 101 rotate by their own weights. The document leading edge regulation state 7 or 8 is surely changed.

  As described above, according to the sheet conveying apparatus of the present embodiment, the shutter 100 is disposed between the pickup roller 7 and the feed roller 9, and the shutter 100 does not protrude above the pickup holder 103. Since the size can be reduced and a driving source such as a solenoid is not necessary, an inexpensive configuration can be obtained.

  Further, the rotation shafts of the shutter member (shutter 100) and its restricting member (shutter restricting member 101) are provided non-parallel, and in particular, the relative angle of both the rotating shafts is provided at 90 degrees, so that the restricting member is rotated. When moving the shutter, the shutter does not rotate against the document, so that the force required to rotate the restricting member can be reduced, so that the restricting member can be moved with a small amount of movement of the holding member (pickup holder 103). Since it can be operated, further downsizing is possible.

Next, document conveyance and reading operations in the automatic document conveyance device 1 and the image reading device 2 will be briefly described with reference to FIG.
When a document is set on the document table 5, the document set detection sensor 8 detects the document set, the motor rotates forward, the pickup roller 7 is lowered and pressed against the document, and the pickup roller 7 is clockwise in the figure. Rotate and recall the original. The originals called by the pickup roller are separated one by one by a separating unit having a feed roller 9 and a reverse roller 10. The separating means may be a combination of the feed roller 9 and the separation pad.

  When the sensor 28 detects the leading edge of the document 6 sent out separately, the reading start timing is taken, and reading is started in accordance with the leading edge of the document. Further, when the trailing edge of the document is detected by the sensor 28, the reading end timing is taken and the reading is ended in accordance with the trailing edge of the document. In the single-sided mode, the branching claw 17 is always at the position of the solid line in the figure, so that after reading, the paper is discharged from the paper discharge outlet 13 to the paper discharge tray 14 and stacked on the image side.

  When the duplex mode is set, when a document set is detected, the motor rotates forward, the pickup roller 7 descends and is pressed against the document, and the pickup roller 7 rotates clockwise in the drawing to call the document. . The originals called by the pickup roller are sequentially separated one by one by the feed roller 9 and the reverse roller 10 (or separation pad).

  Next, when the leading edge of the document 6 is detected by the sensor 28, a reading start timing is taken, and reading is started in accordance with the leading edge of the document. When the tip is detected by the sensor 28, the branching claw is moved to the dotted line position in the figure, and the reverse roller 26 is rotated in the normal rotation direction (clockwise direction in the figure). Further, when the leading edge of the document 6 is detected by the sensor 28, the driving of the feed roller 9 and the pickup roller 7 is released by a clutch or the like, and the next document is kept on standby without being fed. When the trailing edge of the document is detected by the sensor 28, the reading end timing is taken, and the reading is ended in accordance with the trailing edge of the document.

  Thereafter, the original is conveyed from the paper discharge outlet 13 to the switchback path (C). After a certain time from the sensor 28 (after a time sufficient for the trailing edge of the original to completely exit the paper discharge port 13), the branching claw 17 is switched to the solid line position in the figure, and the rotation direction of the reverse roller 26 is reversed. (Counterclockwise in the figure), and the document is guided to the conveyance path (d).

  Next, the document that has entered the conveyance path (d) is sent to the conveyance path (b). When the leading edge of the document is detected by the sensor 28, the reading operation of the back surface of the document 6 is performed in the same manner as the front surface. When the tip is detected by the sensor 28, the branching claw 17 is moved again to the dotted line position in the figure, and the reverse roller 26 is rotated in the forward rotation direction. At this time, the pre-reading roller 20 and the reverse roller 26 rotate in opposite directions, but a torque limiter is provided on the reverse roller shaft so as to follow the pre-reading roller. When the reading operation on the back surface is completed, it is switched back again and sent to the transport path (A). At this time, the reading operation is not performed. Even when the leading edge of the document is detected by the sensor 28, the document is discharged onto the discharge tray 14 with the surface facing down by setting the branching claw 17 to the solid line position. When the document passing sensor 8 detects the original at the time when the third passage of the rear end of the original is detected by the sensor 28, the next original feeding operation is performed.

  Thereafter, the above-described operation is repeated until the document set detection sensor no longer detects the document, whereby the duplex document processing for the document on the document stacking table 5 is completed.

Finally, an example of an image forming apparatus to which the automatic document feeder 1 shown in FIG. 1 can be mounted will be described with reference to FIG.
The image forming apparatus shown in FIG. 16 is a so-called tandem type intermediate transfer type full-color electrophotographic apparatus, and is configured as a copying apparatus including an image reading unit. The copying apparatus shown in this figure has an apparatus main body 310 mounted on a paper feed table 320, and a scanner 330 is disposed at the top of the apparatus main body 310. 1 is mounted on a scanner 330. The automatic document feeder 1 shown in FIG.

  The apparatus main body 310 is provided with an endless intermediate transfer belt 301 as an intermediate transfer member at the center. On the upper side of the intermediate transfer belt 301, four image forming units 311 of yellow (Y), magenta (M), cyan (C), and black (K) are arranged side by side along the belt moving direction. A tandem image forming unit 350 is configured. An exposure device 309 is further provided on the tandem image forming unit 350.

  A secondary transfer device 315 is provided on the opposite side of the intermediate transfer belt 301 from the tandem image forming unit 350. Next to the secondary transfer device 315, a fixing device 319 for fixing the unfixed image transferred onto the paper is provided. The secondary transfer device 315 also has a paper transport function for transporting the paper after image transfer to the fixing device 319. The fixing device 319 is configured by pressing a pressure roller 307 against the fixing roller 306. The fixing roller 306 has a heat generating mechanism inside and is heated to a temperature necessary for image fixing. The unfixed image on the paper is fixed on the paper by applying heat and pressure. The fixing device may be a belt fixing method. Further, below the secondary transfer device 315 and the fixing device 319, a sheet reversing unit 308 that reverses the sheet so as to record images on both sides of the sheet is provided.

  Now, when making a copy using this electrophotographic apparatus, the original is set on the original table of the automatic original conveying apparatus 1. Alternatively, the automatic document feeder 1 is opened, a document is set on the contact glass of the scanner 330, and the automatic document feeder 340 is closed and pressed.

  When a start switch (not shown) is pressed, the original is automatically conveyed when the original is set on the automatic document feeder 340. When the original is set on the contact glass 331, the scanner 330 is immediately driven to read the original contents. read.

  In parallel with document reading, the intermediate transfer belt 301 is driven to rotate. Then, in each image forming unit 311, the photosensitive drum 312 is rotated and exposed and developed on each photosensitive drum 312 using information for each color of yellow, magenta, cyan, and black to form a single color toner image. To do. As the intermediate transfer belt 301 moves, the single color toner images are sequentially transferred to form a composite color image on the intermediate transfer belt 301.

  On the other hand, in parallel with the image formation, one of the paper feed rollers 321 of the paper feed table 320 is selectively rotated to feed out the paper from one of the paper feed cassettes 323 provided in multiple stages, and the paper is separated one by one. And then abuts against the registration roller 328 and stops. Alternatively, the paper on the manual feed tray 336 is fed out, separated one by one, and abutted against the registration roller 328 and stopped.

  Then, the registration roller 328 is rotated in synchronization with the composite color image on the intermediate transfer belt 301, the sheet is fed between the intermediate transfer belt 301 and the secondary transfer device 315, and is transferred by the secondary transfer device 315. Record a color image on paper.

  The paper after the image transfer is transported by the belt 316 and sent to the fixing device 319. The fixing device 319 applies heat and pressure to fix the transferred image, and is then switched by the switching claw 339 and discharged by the discharge roller 342. And stacked on the paper discharge tray 343. Alternatively, it is switched by the switching claw 339 and put into the sheet reversing unit 308, where it is reversed and guided again to the transfer position, and an image is recorded also on the back surface, and then discharged onto the paper discharge tray 343 by the discharge roller 342.

  On the other hand, the intermediate transfer belt 301 after the image transfer is removed by the intermediate transfer belt cleaning device 305 to remove residual toner remaining on the intermediate transfer belt 301 after the image transfer, and prepares for the image formation by the tandem image forming unit 350 again.

  As mentioned above, although this invention was demonstrated by the example of illustration, this invention is not limited to this. For example, the shape of the shutter member is arbitrary as long as the present invention can be implemented. Also, the sheet calling means and the sheet feeding means can adopt appropriate forms such as a roller shape or a roller shape. The configuration of the separation unit is also arbitrary.

In the automatic document feeder, the configuration of the document feeder is arbitrary. Further, the reading method in the image reading apparatus is also arbitrary.
The configuration of the image forming unit of the image forming apparatus is also arbitrary, and the arrangement order of the color image forming units in the tandem system is arbitrary. Further, not only the intermediate transfer method but also a direct transfer method may be used. Furthermore, it is not limited to the tandem type. The present invention can also be applied to a full color machine using three color toners, a multicolor machine using two color toners, or a monochrome apparatus. Of course, the image forming apparatus is not limited to a copying apparatus, but may be a printer, a facsimile machine, or a multifunction machine having a plurality of functions.

DESCRIPTION OF SYMBOLS 1 Automatic document feeder 2 Image reading device 7 Pickup roller (sheet calling means)
9 Feed roller (sheet feeding means)
10 Reverse roller (separating member)
100 Document shutter (shutter member)
100b Shutter member rotating shaft 101 Shutter restricting member 101c Shutter restricting member rotating shaft 102 Shutter holder (regulator holding means)
103 Pickup holder (holder member)
103a Projection part of pickup holder 104 Feed roller shaft 105 Torque limiter 112 Upper cover 310 Copier main body 320 Paper feed table 330 Scanner

JP 2002-96935 A

Claims (13)

A sheet calling unit that calls a sheet set in the sheet setting unit, and a separation feeding unit that includes a sheet feeding unit and a separation member and separates and feeds the sheets called by the sheet calling unit one by one. A sheet conveying apparatus comprising:
A shutter member rotatably provided at a restriction position for restricting the leading edge of the sheet set in the sheet setting portion and a restriction release position at which the restriction is released;
A shutter restricting member that is rotatably provided at a restriction position that restricts the rotation of the shutter member in conjunction with the raising and lowering of the sheet calling means and a restriction release position that does not restrict the rotation;
The sheet conveying device according to claim 1, wherein the rotation shaft of the shutter member and the rotation shaft of the shutter regulating member are provided in non-parallel.   The sheet conveying apparatus according to claim 1, wherein a relative angle between a rotation axis of the shutter member and a rotation axis of the shutter regulating member is set to approximately 90 degrees.   At the time of sheet calling by the sheet calling means, a holder member that holds the sheet calling means abuts against the shutter restricting member and moves the shutter restricting member from the restriction position to the restriction release position. The sheet conveying apparatus according to claim 1 or 2. The length from the rotation fulcrum of the shutter restricting member to the contact portion with the holder member is X,
When the length from the rotation fulcrum of the shutter regulating member to the contact portion with the shutter member is Y,
Y> X
The sheet conveying device according to claim 3, wherein   The moving amount of the shutter restricting member with respect to the moving amount of the holder member at the time of sheet calling by the sheet calling means is provided so as to become smaller from the middle of movement of the holder member. The sheet conveying apparatus according to 4.   The sheet conveying apparatus according to claim 1, wherein the shutter member and the shutter regulating member are arranged between the sheet calling unit and the sheet feeding unit.   The shutter restricting member is positioned below the uppermost position of the holder member that holds the sheet calling means in both the restricting state in which the rotation of the shutter member is restricted and the restriction releasing state in which the rotation is not restricted. The sheet conveying apparatus according to claim 6, wherein the sheet conveying apparatus is provided. The shutter member and the shutter restricting member have a restricting portion holding member that rotatably holds the restricting portion holding member, and the restricting portion holding member is rotatably held on the shaft of the sheet feeding unit.
The restricting portion holding member has a protrusion that extends to the opposite side of the shutter member and the shutter restricting member across the shaft of the sheet feeding means, and the protrusion is a predetermined member of the apparatus main body. The sheet conveying apparatus according to claim 1, wherein the posture of the regulating portion holding member is maintained by contacting the sheet.   The sheet conveying apparatus according to claim 8, wherein the predetermined member of the apparatus main body is an upper cover provided to be openable and closable.   The sheet conveying apparatus according to claim 1, wherein a shaft of the sheet feeding unit is supported by a frame of the apparatus main body.   An automatic document conveying device comprising the sheet conveying device according to claim 1.   An image reading apparatus comprising the sheet conveying apparatus according to claim 1 or the automatic document conveying apparatus according to claim 11. An image forming apparatus comprising any one of the sheet conveying device according to claim 1, the automatic document conveying device according to claim 11, and the image reading device according to claim 12. .

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