JP5413079B2 - Automatic document feeder, image forming apparatus, and image reading apparatus - Google Patents

Description

  The present invention relates to an automatic document feeder, an image forming apparatus, and an image reading apparatus that separate documents one by one on a document placing table one by one and convey them to an image reading unit.

An automatic document feeder of the above type is well known and is mounted on an image forming apparatus or an image reading apparatus such as a copying machine or a facsimile. In this type of automatic document feeder, a separation unit that applies separation pressure to the document and separates the documents one by one is provided so that a large number of documents are not simultaneously conveyed to the image reading unit. Then, the automatic document feeder in consideration of a case where a jam occurs in the separation section, has been found a mechanism capable of releasing the separation pressure, the jam treatment is to be able to state releasing the separation pressure Yes.

  In Patent Document 1, for the purpose of releasing the separation pressure, a first position for releasing the pressure contact between the separation member 4 and the separation conveyance member 5 and a second position for pressure-contacting the separation member 4 and the separation conveyance member 5 are selected. In order to release the pressure contact between the separation member 4 and the separation conveying member 5 in conjunction with the operation of closing the cover member 50 provided in the apparatus main body so as to be opened and closed, the first pressure release means 100 is provided. A configuration is disclosed in which the pressure release means 100 that has been moved to the position is returned to the second position.

Further, it is known that the automatic document feeder shown in FIG. 7 is provided with a mechanism for releasing the separation pressure shown in FIGS. 8 to 11 and will be described.
In FIG. 7, reference numeral 1 denotes an automatic document feeder, which is attached to an upper part of an image reading apparatus 2 such as a copying machine, a facsimile, a scanner or the like so as to be opened and closed.

  In the automatic document feeder 1, when the document 4 is set on the document setting table 3, the upper curl or the like of the document 4 is regulated by the document press 5. Since the document presser 5 has a smaller probability of jamming and image disturbance when the document is restricted until just before the calling roller 6, the openable / closable paper feed cover 7 and the document presser 5 may overlap. Next, when the calling roller 6 rotates, the originals are sent out to the separation unit 8, and the separation unit 8 separates the originals one by one. Thereafter, the sheet passes through the roller pair 9 and 10 and is read by the contact glass 11. When the back side is not read, the paper passes through the paper discharge roller pair 12 and is discharged to the paper discharge location 13 as it is. Reference numerals 14 and 15 denote a switching claw and a reverse roller used when reading a double-sided document.

  Jam may occur when using the automatic document feeder. When a jam occurs, it is necessary to remove the jammed document. Therefore, it is necessary to release the roller pressure and pull out the document with the user's hand or rotate the roller to eject the document. In the case of the automatic document feeder having the configuration shown in FIG. 7, the separation pressure is released by removing the feed unit 16, and the reverse roller pair 15 is configured to be able to release the roller pressure by rotating the document setting table 3. Also, the roller pressures of the roller pairs 9 and 10 can be released by opening the paper feed cover 7. Therefore, all the jams can be processed by rotating the paper discharge roller pair 14 with a jam processing dial or the like. 7 includes the feed roller 20 and the separation pad 21 in contact with the feed roller 20, but is not limited to the above-described configuration.

Next, a configuration in which the jam removal operability of the separation unit 8 shown in FIG. 7 is improved will be described.
FIG. 8 is a perspective view of the separation unit 8 of the automatic document feeder 1.
In FIG. 8, the separation unit 8 is provided with a separation pressure intermittent arm 18, a separation pressure intermittent arm driving tension spring 19, and a separation folder 22 on a paper feed guide 17 that is a fixed housing provided to face the feed unit 16. It is assembled. The separation folder 22 can be rotated in a direction in which the separation pad 21 contacts and separates from the feed roller 20 and is provided in the paper feed guide 17. The separation folder 22 includes a separation pad 21 and a compression spring 23 for separation pressure shown in FIG. (Not visible in FIG. 8) is assembled. A compression spring 23 for separation pressure is assembled to the separation folder 22 on the side opposite to the separation pad 21. The separation pad 21 is pressed against the feed roller 20 by the separation pressure compression spring 23 to generate a separation pressure.

  FIG. 9 is a perspective view of a connecting portion between the separation pressure intermittent arm 18 and the separation folder 22. The separation pressure interrupting arm 18 is provided at one end of the rotating shaft 18a, the other end of the rotating shaft 18a reaches near the separation folder 22, and the other end is provided with an operating claw 18b. The separation pressure interrupting arm 18 is centered on the rotating shaft 18a. When it rotates clockwise, the operating claw 18b also rotates clockwise in conjunction with it. The rotated operating claw 18 b pushes the separation folder pin 24 provided in the separation folder 22 and pushes down the separation folder 22. When the separation folder 22 is pushed down, the separation pad 21 is separated from the feed roller 20 and the separation pressure is released.

FIG. 10 is a diagram illustrating the relationship between the change between the open state and the closed state of the paper feed cover 7 and the movement of the separation pressure intermittent arm 18.
The paper feed cover 7 is mounted so as to be rotatable about a paper feed cover rotating shaft 7a. When the paper feed cover 7 is opened, as shown in FIG. 10A, the separation pressure intermittent arm 18 is pulled to the position shown in FIG. 7 is in pressure contact with an abutment piece 7b provided on the surface. After that, as the paper feed cover 7 is transformed to the closed state, it is pushed by the abutting piece 7b as shown in FIG. 10C through FIG. FIG. 10C is a diagram showing a state in use in which the paper feed cover 7 is completely closed.

  FIG. 11 is a side view of the connecting portion between the separation pressure intermittent arm 18 and the separation folder 22. FIG. 10A and FIG. 11A correspond to FIG. 10C and FIG. 11B, respectively. As can be seen from FIG. 11A, when the paper feed cover 7 is opened, the separation pressure intermittent arm 18 is rotated clockwise by the tension spring 19. Then, the operating claw 18b rotates the separation folder 22 clockwise via the separation folder pin 24, the separation pad 21 and the feed roller 20 are completely separated, and the separation pressure is released. On the other hand, as can be seen from FIG. 11B, when the paper feed cover 7 is closed, the operating claw 18b and the separation folder pin 24 are completely separated from each other. Therefore, the separation pressure is generated by the separation pressure compression spring 23 pressing the separation pad 21 against the feed roller 20. In order to realize a mechanism in which the separation folder 22 is separated from the feed roller 20 in conjunction with the opening of the paper feed cover 7 described above, the separation folder 22 is overcome by the operating claw 18b by overcoming the pressing pressure of the separation pressure compression spring 23. It is necessary to select a spring having a pulling force that can be pushed down as the pulling spring 19 for driving the separation pressure interrupted arm.

  In the case of the separation unit 8 described above, the separation pressure of the separation unit 8 is released simply by changing the paper feed cover 7 from the closed state to the open state. Therefore, when a jam occurs in the separation unit, it is possible to pull out the jam original simply by opening the paper feed cover 7. Thus, it can be said that it is a separation part excellent in the operability of jam removal.

  The separation unit 8 of the type in which the feed roller 20 is assembled to the paper feed cover 7 is also excellent in jam handling. However, in this type, the gear train that drives the feed roller 20 needs to be separated each time the paper feed cover 7 is closed. Further, when the feed roller 20 is assembled to the paper feed cover 7, the stacking tolerance with the separation pad 21 increases, and it is difficult to ensure the positional relationship with high accuracy.

  By the way, the automatic document feeder has an automatic document feed mode (hereinafter referred to as ADF mode) that separates and conveys a document by a separation unit, which is an original function, and a separation unit for a special document such as a two-fold document. An apparatus equipped with a manual document feed mode (hereinafter referred to as an MDF mode) in which the separation pressure is released and the document can be conveyed without affecting the load is already known.

  However, in the conventional automatic document feeder, parts sharing of the separation pressure interrupt mechanism and the ADF-MDF mode switching mechanism has not been performed. For this reason, there are problems such as duplication of parts and high cost.

  SUMMARY OF THE INVENTION In view of the above-described conventional problems, the present invention shares parts of a separation pressure interrupting mechanism and an ADF-MDF mode switching mechanism, and is an automatic document feeder and an image with improved operability in each mode at a low cost. An object of the present invention is to provide a forming apparatus and an image reading apparatus.

In order to solve the above-described problems, the present invention provides a feed roller for conveying a document fed from a document table , a document blocking portion provided in contact with the feed roller so as to be able to release the separation pressure, and the document blocking portion as the feed block. An automatic document feeder that includes a separation unit having a pressurizing unit that pressurizes in a direction in contact with a roller, and separates documents one by one by the separation unit and conveys the document to an image reading unit. An automatic document feed mode (hereinafter referred to as ADF mode) that separates and transports the document and a manual document feed mode (hereinafter referred to as MDF mode) that transports the document after releasing the separation pressure of the separation unit. in the document conveying device is provided between the pressurizing means and the original blocking portion, the pressurizing means is brought into contact with the original blocking portion to said feed roller A separation pressure intermittent member that can be moved to an ADF position in which the ADF mode is set and an MDF position in which the document blocking portion is released into the MDF mode in which the separation pressure to the feed roller is released, and can be opened and closed to cover the separation portion A separation pressure control member that is provided in the open / close housing and switches the separation pressure intermittent member between the ADF position and the MDF position, and the separation pressure control member is in a closed state when the open / close housing is in a closed state; By operating the separation pressure control member, the separation pressure intermittent member is switched between the ADF position and the MDF position, and when the open / close housing is opened, the separation pressure control member is separated from the separation pressure intermittent member, An automatic document feeder is proposed in which a separation pressure interrupting member is positioned at the MDF position .

In the present invention, it is advantageous that the separation pressure control member is provided with a locking means for locking the separation pressure intermittent member at each of the ADF position and the MDF position of the separation pressure intermittent member. is there.
Further, according to the present invention, it is advantageous that the separation pressure control member locked at the MDF position is returned to the ADF position when the opening / closing casing is opened.

Furthermore, the present invention advantageously biases the separation pressure control member to an elastic action located at the ADF position, and the MDF position is operated and held by a user against the elastic action. .
Furthermore, the present invention is advantageously provided with a mode detection sensor for detecting whether the ADF mode or the MDF mode.

In order to solve the above-mentioned problems, the present invention proposes an image forming apparatus including the automatic document feeder according to any one of claims 1 to 6.
Furthermore, in order to solve the above-mentioned problems, the present invention proposes an image reading apparatus equipped with the automatic document feeder according to any one of claims 1 to 6.

  According to the present invention, it is possible to provide a separation pressure release mechanism, an ADF mode, and an MDF mode switching mechanism that are lower in cost than ever. Further, when a user mistakenly conveys a large number of documents in the MDF mode and a jam occurs, the housing is changed to an open state, jam processing is performed, the document is transported after the housing is closed again. By automatically switching to the ADF mode at this time, there is also an effect of preventing a large number of originals from being erroneously and continuously conveyed in the MDF mode.

FIG. 3 is a perspective view showing a separation unit of the automatic document feeder according to the present invention. (A), (b), (c) is side explanatory drawing which shows the action | operation of the separation part of the automatic document feeder shown in FIG. It is side surface explanatory drawing which shows the relationship between a separation pressure intermittent arm, a separation pressure control member, and force. It is sectional drawing which shows the latching shape of a separation pressure intermittent arm and a separation pressure control member. (A), (b) is explanatory drawing of the isolation | separation part which provided the mode detection sensor. (A) And (b) is a figure which shows a state at the time of ADF mode or MDF mode, (c) is a figure which shows the state which opened the paper supply cover 7 from each mode. 1 is a schematic diagram illustrating an overall configuration of an automatic document feeder. It is a perspective view which shows the separation part of the conventional automatic document feeder. FIG. 6 is a perspective view of a connecting portion between a separation pressure interrupted arm and a separation folder of the automatic document feeder. (A), (b), (c) is a figure which shows the relationship between the change between the open state of a paper feeding cover, and a closed state, and a separation pressure intermittent arm movement. It is a side view of the connection part of a separation pressure interruption arm and a separation folder.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a perspective view showing a separation unit of an automatic document feeder according to the present invention, and FIG. 2 is an explanatory side view showing the operation of the separation unit.

The separator 8 shown in FIGS. 1 and 2 is applied to an apparatus similar to the automatic document feeder shown in FIG. 7, and the same members are denoted by the same reference numerals.
The separation pressure intermittent arm 18 shown in FIG. 1 mirrors that shown in FIGS. 8 to 11 and has a deformed shape. The separation pressure intermittent arm 18 is supported by a paper feed guide 17 that is a fixed housing so as to be rotatable about a rotation shaft 18a. As shown in FIG. 2, the separation pressure intermittent arm 18 is provided with an operating claw 18b at its left end, and when the arm rotates counterclockwise via the rotary shaft 18a as shown in FIG. 2 (c). The operation claw 18b pushes the separation folder pin 24 provided in the separation folder 22, the separation folder 22 is pushed down, and the separation pad 21 is separated from the feed roller 20. Further, on the right side of the rotary shaft 18a of the separation pressure interrupting arm 18, a gentle convex portion 18d is formed on the upper side of the separation pressure intermittent arm 18 following the gentle concave portion 18c. It is touched. Further, the separation pressure interrupting arm 18 is provided with a tension spring 19 for driving the separation pressure interrupting arm which gives an elastic action in the direction of separating the separation pad 21 from the feed roller 20.

  The automatic document feeder according to the present embodiment has an automatic document feed mode (ADF mode) in which a separation pressure is generated and a large number of documents can be separated while being conveyed, and the influence of the load on the separation unit 8 by releasing the separation pressure. A separation pressure control member 25 that can be switched to a manual document feed mode (MDF mode) that can convey a document without receiving the document is provided. The separation pressure control member 25 includes a lever portion 25a that is operated by a user and a mounting portion 25b that is rotatably mounted via a pin 26 on a paper feed cover 7 that is an open / close housing. .

  As shown in FIG. 2A, the separation pressure control member 25 is in a position where the lever portion 25a is aligned with the surface of the paper feed cover 7, as will be described later. At this time, the separation pressure control member 25 is mounted. The tip of the portion 25 b is in contact with the convex portion 18 d of the separation pressure intermittent arm 18. The separation pressure control member 25 is provided with a tension spring 27 for rotating the separation pressure control member for energizing the counterclockwise rotation of the drawing around the pin 26 so as to be held at the ADF mode position. . The paper feed cover 7 is provided with a stopper (not shown) that holds the separation pressure control member 25 at a position aligned with the surface of the paper feed cover 7 against the action of the spring, and this position is the ADF mode position. is there. In addition, as a stopper, the upper edge of the mounting part 25b of the separation pressure control member 25 may be used, or the stopper may be held by hitting the lower part of the lever part 25a.

  Further, as shown in FIG. 2C, the separation pressure control member 25 enters the MDF mode when the lever portion 25a is raised against the action of the tension spring 27 for turning the separation pressure control member. In the separation pressure control member 25 at the MDF position, the separation pressure intermittent arm 18 rotates counterclockwise by the action of the tension spring 19, and the operation claw 18 b pushes the separation folder pin 24 and pushes the separation folder 22 down as described above. Thus, the separation pad 21 is separated from the feed roller 20.

  Thus, by rotating the lever portion 25a of the separation pressure control member 25, the separation portion 8 can be switched from the ADF mode to the MDF mode in which the separation pressure is released. At this time, the tension spring 27 for rotating the separation pressure control member has its own force overcoming the force of the tension spring 19 for driving the separation pressure intermittent arm from the state of FIG. The spring is selected with a force that does not return to. On the contrary, the separation pressure control member 25 may be set so that the force of the tension spring 27 for rotating the separation pressure control member is strong and the separation pressure control member 25 naturally returns to the state of FIG. 2A. Therefore, the MDF mode cannot be used, and the user operates the separation pressure control member 25 while maintaining the separation pressure control member 25 at the MDF position. However, since it naturally returns to the ADF position in this way, it is possible to prevent the user from setting a large number of documents without noticing the MDF mode.

  In the automatic document feeder configured as described above, the lever portion 25a of the separation pressure control member 25 and the paper feed cover 7 are on the same surface in the ADF mode, and rise in the MDF mode to form different surfaces. This improves the design in the ADF mode. Further, the visibility of the user is improved in the MDF mode in which the original cannot be separated by the separation unit, and a large number of originals are prevented from being set by mistake.

FIG. 3 is an explanatory side view showing the relationship between the separation pressure intermittent arm 18 and the separation pressure control member 25 and the force.
In FIG. 3, the symbol F indicates the force applied to the separation pressure control member 25 by the tension spring 19 for driving the separation pressure intermittent arm. The direction of the force F acts on the right side in the drawing with respect to the pin 26 of the separation pressure control member 25. Thus, when the force F acts in the right direction, the counterclockwise rotation of the separation pressure control member 25 is fed. Since it is regulated by the cover 7, the position of the separation pressure release arm 18 is held at the position shown in FIG. Therefore, it is possible to maintain the ADF mode. On the other hand, when the force F acts on the left side of the pin 26 of the separation pressure control member 25, the separation pressure intermittent arm 18 is rotated counterclockwise by the tension spring 19 for driving the separation pressure intermittent arm, and FIG. ) State. Therefore, the ADF mode cannot be maintained. When the force F works in the left direction, as shown in FIG. 4, the ADF mode is maintained by providing a locking shape 28 for locking the separation pressure intermittent arm 18 and the separation pressure control member 25. can do. By maintaining the ADF mode and the MDF mode, the user can use each mode continuously.

  FIG. 5A is a diagram in which each mode of the ADF mode and the MDF mode can be reliably detected by adding a mode detection sensor to the separation unit of FIG. The mode detection sensor 30 in FIG. 5 uses a transmission type sensor, and as shown in FIG. 5B, the mounting portion 25b also serves as a sensor filler to the separation pressure control member 25, thereby minimizing the cost increase. it can. Further, by using the push-pull sensor 31 as the mode detection sensor and pressing the sensor with the separation pressure control member 22, it is possible to suppress the cost increase as described above.

  Thus, if a mode detection sensor is added and each mode is detected by the sensor, each mode can be notified appropriately through the display unit or the like, and the visibility of each mode of the user can be improved. Further, by improving the visibility of the user, it is possible to prevent jamming due to conveyance of a non-separable document in the ADF mode and double feeding jam due to conveyance of a large number of documents in the MDF mode.

FIG. 6 is a diagram illustrating a state in which the paper feed cover 7 is changed from the closed state to the open state by jam processing or the like and is returned to the closed state again in the ADF mode or the MDF mode. 6 (a) at the time of ADF mode, FIG. 6 (b) MDF mode, FIG. 6 (c) each mode or al feeding cover 7 represents the open Raita state.

  In any of the ADF mode and the MDF mode, when the paper feed cover 7 is opened with the paper feed cover rotating shaft 7a as a fulcrum, the separation pad 21 is separated from the feed roller 20. Therefore, even if the original jams in the state of being sandwiched by the separation unit 8, it can be taken out without damaging the original for releasing the separation pressure. Further, when the paper feed cover 7 is opened, the separation pressure control member 25 is separated from the separation pressure intermittent arm 18, so that the separation pressure control member 25 is positioned by the paper feed cover 7 by the tension spring 27 for turning the separation pressure control member. Rotate to the ADF position. Therefore, when the paper feed cover 7 is opened, the separation unit 8 enters the ADF mode shown in FIG. As a result, it is possible to prevent the user from repeating the mistake that the user mistakenly conveys a large number of documents many times without realizing that the user is in the MDF mode.

DESCRIPTION OF SYMBOLS 7 Paper feed cover 8 Separation part 17 Paper feed guide 18 Separation pressure interruption arm 19 Separation pressure interruption arm drive tension spring 20 Feed roller 21 Separation pad 22 Separation folder 25 Separation pressure control member 27 Separation pressure control member rotation tension spring

JP 2003-037705 A

Claims (7)

A feed roller for transporting a document fed from the document table, a document blocking portion provided in contact with the feed roller so as to be able to release the separation pressure, and a pressurizing means for pressing the document blocking portion in a direction to contact the feed roller And a separation part having
An automatic document feeder for conveying separated one by one a document by the separation section to the image reading unit, the separation unit with automatic document feed mode for conveying separate the document (hereinafter, referred to as ADF mode.) And In an automatic document feeder having a manual document feed mode (hereinafter referred to as MDF mode) for releasing a separation pressure of the separation unit and conveying a document,
An ADF position that is provided between the document blocking unit and the pressing unit, and in which the pressing unit causes the document blocking unit to abut against the feed roller, and the document blocking unit is set to the feed roller. A separation pressure intermittent member movable to the MDF position to be the MDF mode in which the separation pressure is released;
A separation pressure control member that is provided in an openable and closable casing that covers the separation portion, and that switches the separation pressure intermittent member between the ADF position and the MDF position;
When the open / close housing is in the closed state, the separation pressure control member is switched between the ADF position and the MDF position by operating the separation pressure control member, and the open / close housing is opened. And the separation pressure control member is separated from the separation pressure intermittent member, and the separation pressure intermittent member is positioned at the MDF position . 2. The automatic document feeder according to claim 1, wherein the separation pressure control member is provided with a locking means for locking the separation pressure interrupting member at each of the ADF position and the MDF position of the separation pressure interrupting member. An automatic document feeder characterized by the above.   3. The automatic document feeder according to claim 2, wherein the separation pressure control member locked at the MDF position is returned to the ADF position when the opening / closing housing is opened and then closed. Automatic document feeder.   4. The automatic document feeder according to claim 1, wherein an elastic action located at the ADF position is urged against the separation pressure control member, and the MDF position is resisted against the elastic action. An automatic document feeder that is operated and held by a user.   2. The automatic document feeder according to claim 1, further comprising a mode detection sensor for detecting whether the ADF mode or the MDF mode.   An image forming apparatus comprising the automatic document feeder according to claim 1.   An image reading apparatus comprising the automatic document feeder according to any one of claims 1 to 5.

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