JP3873944B2 - Document feeder - Google Patents

Description

  The present invention is used in an image forming apparatus such as a copying machine, a printer, or a facsimile machine, and includes a reading roller and a contact image sensor facing the reading roller, and the space between the reading roller and the contact image sensor. The present invention relates to a document feeder that reads an image on a passing document with a contact image sensor.

  In general, there is a document feeding apparatus in which an image on a document passing between a reading roller and a contact image sensor is read by a contact image sensor to obtain image data. In the apparatus, the reading roller and the contact-type image sensor are often contaminated with paper powder, and when the reading roller and the contact-type image sensor are stained with paper powder or the like, streaks or the like enter the image during image formation. For this reason, it is necessary to periodically clean the contact image sensor and the reading roller.

  By the way, since the reading roller and the contact image sensor are in close contact with each other, when the reading roller and the contact image sensor are cleaned, it is necessary to separate the reading roller from the contact image sensor. First, after removing the lower surface of the document reading apparatus, the guide frame body supporting the reading roller is removed, and the reading roller and the contact image sensor are separated to perform cleaning. For this reason, it is very troublesome to clean the reading roller and the contact image sensor, and it is particularly difficult for the user to clean the reading roller and the contact image sensor.

  On the other hand, in order to improve the maintainability of the image reading device built in the document feeding device, the document feeding device constitutes an upper unit that can be freely opened and closed with respect to the lower image reading device. A first image sensor for reading an image on one side of the original sheet, and a backup guide for pressing the original sheet conveyed facing the reading side of the image sensor toward the reading side; A backup guide is detachably attached to the lower image reading device side in the upper unit, and the upper unit reads an image on the other side of the original sheet in the image reading device when closed on the image reading device. The second image sensor is in contact with the platen disposed below, and the backup guide contacts the platen. There are those to be disposed (see Patent Document 1).

JP 2002-152462 A (paragraph (0019) to paragraph (0033), FIGS. 1 to 3)

  As described above, in the conventional document feeder, it is difficult for the user to easily expose the reading roller and the contact image sensor to clean the reading roller and the contact image sensor, and the reading roller holds the reading roller and the contact image sensor. When removing the guide frame body from the document feeder housing, the guide frame body may be accidentally dropped.

  In any case, the conventional document feeder has a problem that the reading roller and the contact image sensor cannot be easily exposed.

  SUMMARY OF THE INVENTION Accordingly, in view of the problems of the prior art, the present invention provides a document feeding device that can expose a contact image sensor and a reading roller very easily and easily clean the contact image sensor and the reading roller. For the purpose.

Accordingly, in order to solve the above-described problem, the present invention includes a reading roller and a contact image sensor arranged to face the reading roller, and passes between the reading roller and the contact image sensor. An image reading unit that reads the upper image with the contact image sensor and obtains image data, and supports the image reading unit, and one of both end sides parallel to the document feeding direction is the front end side, and the other is the rear end side. In a document feeder having a set device casing,
A guide unit that is disposed under the contact image sensor and supports the reading roller;
An original mat member which is located below the guide unit and forms a lower surface of the apparatus housing;
Hinge means for rotatably supporting the original mat member on the rear end side of the apparatus housing;
Guide unit support means for rotatably supporting the guide unit on the rear end side of the apparatus housing;
The original mat member and the guide unit are opened on the front end side of the apparatus casing with an axis parallel to the original feeding direction positioned on the rear end side of the apparatus casing as a pivot point. Features.

  In the present invention, the hinge means regulates the rotation of the original mat member at a predetermined rotation angle, and the guide unit support means places the guide unit on the rear end side of the apparatus casing. Guide unit rotation means that rotates as a rotation fulcrum, and speed regulation means that regulates the rotation speed of the guide unit.

  In the present invention, the guide unit rotation means includes, for example, a support shaft body that is disposed on the rear end side of the guide unit and rotatably supports the guide unit, and the speed regulating means is the support shaft. A torsion spring member is attached to the body and compressed as the guide unit rotates downward. Further, a torque limiter mechanism that restricts torque when the guide unit rotates may be used as the speed restricting means.

  As described above, the document feeder according to the present invention is disposed below the contact image sensor and supports the reading roller, and is positioned below the guide unit to form the lower surface of the apparatus housing. Since the original mat member is opened on the front end side of the apparatus casing with the rear end side of the apparatus casing as a pivot point, the contact image sensor and the reading roller can be exposed very easily and easily. There is an effect that the contact image sensor and the reading roller can be cleaned.

Further, according to the present invention, when the guide unit is rotated and opened with the axis parallel to the document feeding direction positioned on the rear end side of the apparatus housing as a rotation fulcrum, the rotation speed of the guide unit is regulated. As a result, the user does not need to put a hand or the like on the guide unit, and no impact is applied to the guide unit.

  Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention unless otherwise specified, but are merely illustrative examples. Not too much.

  First, referring to FIG. 1, here, an illustrated automatic document feeder (auto feeder) 10 is used together with an image forming apparatus (for example, a copying machine), and an upper surface of an image forming apparatus (not shown) main body. Placed on the side. The automatic document feeder 10 includes a document feeding tray (sheet stacking unit) 11 and a document feeding mechanism (sheet feeding mechanism) 12. A document bundle is placed on the document feeding tray 11. Is done. The document feeding mechanism 12 separates the documents one by one from the document bundle placed on the document feeding tray 11, and conveys the documents to the first image reading position GP1.

  Then, after an image on one side of the original is read by the scanner unit (not shown) at the first image reading position GP1, the original is sent to the second original reading position GP2. An image reading device 13 is disposed at the second document reading position GP2, and the image reading device 13 reads a document on the other side of the document. Then, the document is discharged by a pair of discharge rollers 16 to a document discharge tray 15 disposed below the document feed tray 11.

  The illustrated automatic document feeder 10 is compatible with double-sided printing. When single-sided printing is performed, for example, the image on the original is read only at the first image reading position GP1. Although not shown, in the image forming apparatus, an image carrier such as a photosensitive drum is exposed based on image data obtained by reading a document, and an electrostatic latent image is formed on the image carrier. . Then, after the electrostatic latent image is developed by the developing device, the toner image on the image carrier is transferred to the recording paper, the toner image on the recording paper is fixed, and the paper is discharged onto a paper discharge tray.

  As shown in FIG. 1, the document feeding mechanism 12 is disposed on the rear side (downstream in the document transport direction) of the document feeding tray 11, and the document feeding mechanism 12 includes a document feeding roller unit (hereinafter simply referred to as “sheet feeding roller unit”). The document feed roller unit 14 includes a roller housing 14a, a pickup roller (pickup roller) 14b, a feed mechanism 14c, and a separation roller 14d. Further, the document feeding mechanism 12 has a document feeding unit 20 disposed on the downstream side of the feed mechanism 14c. The document feeding unit 20 has a large-diameter driving roller 21 and small-diameter driven rollers 22-24. And. The peripheral surfaces of the driven rollers 22 to 24 are in contact with the peripheral surface of the drive roller 21. Then, the original is sent to the first original reading position GP 1 by the original feeding section 20, passes through the second original reading position GP 2, and is discharged to the original discharge tray 15 by the discharge roller 16.

  The image reading device 13 includes a reading roller 31 and a contact image sensor 32, and the contact image sensor 32 faces the reading roller 31 with a slight gap (for example, about 3 mm). A document passes between the contact image sensor 32 and an image on the document is read by the contact image sensor 32. The contact type image sensor 32 shown in the figure is supported by a sensor housing (sensor frame) 32a, and one end surface side (the back side in FIG. 1) of the sensor frame 32a is an automatic document feeder housing (hereinafter, device housing). (Referred to as a body) 10a is loosely fitted by a support point portion 10b. The reading roller 31 is supported by a guide frame body 33 together with one of the driven roller 24 and the document discharge roller pair 16 described above to form a guide unit 34.

  Referring to FIG. 2, FIG. 2 is a side view showing the contact image sensor 32 and the guide unit 34 from the front side, and the sensor frame 32a is supported by the apparatus housing 10a as described above. On the other hand, the reading roller 31 is supported by a guide frame body 33 (FIG. 1), and the rear end (right end in FIG. 2) of the shaft 31a of the reading roller 31 is loosely fitted to the guide frame body 33. A flange (not shown) is formed on a bearing (not shown) located inside the shaft 31 a, and the outer diameter of the flange is slightly larger than the outer diameter of the reading roller 31. The collar portion is in contact with the lower surface of the contact image sensor 32, and the contact image sensor 32 faces the reading roller 31 with a slight gap. The shaft 31 a is rotatably held by a reading roller holding member 38, and the reading roller holding member 38 is supported by a guide frame body 33. Further, a reading roller positioning member 39 extending downward is attached to the front end side of the sensor frame 32a. The reading roller positioning member 39 causes the shaft 31a of the reading roller 31 to move relative to the sensor frame 32a as will be described later. Positioned.

  A glass plate (transparent member) 32 b is fitted into the contact image sensor 32, and the glass plate 32 b is in close contact with the peripheral surface of the reading roller 31. The reading roller holding member 38 is formed with a long hole 38a extending in parallel with the document conveying direction (direction indicated by a solid line arrow in FIG. 5), and a shaft 31a is inserted into the long hole 38a. One end (right end in FIG. 5) of the reading roller holding member 38 is rotatably attached to the guide frame body 33 by a fulcrum shaft member 38b, and a shaft support member 40 that supports the fulcrum shaft member 38b is described later. When the guide unit 34 is turned in the release direction, the guide unit 34 is lowered.

  As shown in FIG. 2, the reading roller positioning member 39 has a pair of hollow protrusions 39a and 39b, and when the glass plate 32b is in close contact with the peripheral surface of the reading roller 31, as shown in the drawing. The shaft 31a is held between the hollow protrusions 39a and 39b, and the shaft 31a (that is, the reading roller 31) is positioned by the hollow protrusions 39a and 39b.

  FIG. 3 is a side view showing the contact image sensor 32 and the guide unit 34 from the rear side. The shaft 31 a of the reading roller 31 is supported by the guide frame body 33 by the shaft support member 41. That is, as shown in FIG. 3, an opening 41a is formed on one end side (right end side in the figure) of the shaft support member 41, and the end portion of the shaft 31a is loosely fitted in the opening 41a. The shaft support member 41 has a substantially bowl shape as shown in the figure, and a fulcrum shaft member 38b is mounted at the center thereof.

  The shaft support member 41 is rotatably supported by the fulcrum shaft member 38b, and a coil spring (not shown) is hung on the end portion of the shaft support member 41 (the hole portion indicated by reference numeral 42 in FIG. 3). The shaft support member 41 is biased counterclockwise by a coil spring. That is, the reading roller 31 is urged toward the contact image sensor 32 side. Then, as will be described later, when the guide unit 34 is unmounted, the guide unit 34 moves downward around the support shaft 43 that is rotatably supported by the support stay 43a, and the reading roller 31 and the glass plate 32b. The close contact with the (contact image sensor 32) is released. The torsion spring member 44 attached to the support shaft body 43 acts to alleviate an impact when the guide unit 34 moves downward. Further, when the guide unit 34 is removed and lowered, the shaft support member 41 has a hitting role for restricting the upward movement of the reading roller 31 against this biasing.

  The other end of the shaft support member 41 is supported by a support member 42 attached to the rear surface of the guide frame body 33. Then, as will be described later, when the attachment of the guide unit 34 is released, the guide unit 34 rotates downward with the support shaft body 43 as a fulcrum, and the reading roller 31 and the glass plate 32b (contact image sensor 32). The close contact is released. The torsion spring member 44 attached to the support shaft body 43 acts to alleviate an impact when the guide unit 34 moves downward.

Referring to FIG. 4, FIG. 4 is a perspective view of the automatic document feeder 10 as viewed from below. One of both end sides parallel to the document feeding direction is set as the front end side, and the other is set as the rear end side. A document mat member 45 is disposed on the lower surface of the apparatus housing 10a. The document mat member 45 is rotatably supported by a hinge mechanism 45a on the rear end side of the apparatus housing 10a. Further, a plurality of magnet bodies 45b are disposed on the inner surface of the original mat member 45, and the original mat body 45 is attached to the apparatus housing 10a by these magnet bodies 45b. The hinge mechanism 45a has a pair of arm portions 451 attached to the rear side of the original mat member 45, and these arm portions 451 are inserted into opening holes 452 formed on the rear side of the apparatus housing 10a. The device housing 10a is rotatably supported. The arm portion 451 is formed with a stopper 45c that restricts the rotation of the arm portion 451 (see also FIG. 7). Now, when the front end side of the original mat member 45 is pulled downward by hand, the fixed state between the magnet body 45b and the apparatus housing 10a is released, and the original mat member 45 is rotated downward by the hinge mechanism 45a. At this time, the original mat member 45 is stopped at a predetermined rotation angle by the stopper 45c provided in the hinge mechanism 45a.

  Referring also to FIG. 5 (FIG. 5 is a side view excluding the reading roller positioning member 39), a release lever 46 is provided on the lower surface of the guide unit 34, and the release lever 46 is indicated by a solid arrow in the figure. When slid in the direction, the pressing portion 46a provided in the release lever 46 presses the lower end of the shaft support member 40 in the direction indicated by the solid line arrow. The shaft support member 40 is rotatably attached to the apparatus housing 10a and is urged counterclockwise about a fulcrum shaft 40a by a coil spring (not shown). The pressing portion 46a rotates the shaft support member 40 clockwise against the above urging. That is, the lower end side of the shaft support member 40 rotates around the fulcrum shaft 40a in the direction indicated by the broken line arrow. As a result, the upper end side of the shaft support member 40 rotates in the direction indicated by the one-dot chain line arrow. After the release, the shaft support member 40 returns to the original position by the coil spring. When the guide unit 34 is set, the fulcrum shaft member 38b rises while being in contact with the inclined portion of the shaft support member 40, and accordingly, the shaft support member 40 rotates and retracts clockwise. When the fulcrum shaft member 38b reaches a predetermined position, the shaft support member 40 is rotated counterclockwise by the force of the coil spring and is received in the locking portion.

  As a result, the fulcrum shaft member 38b is disengaged from the shaft support member 40, and the guide unit 34 rotates around the support shaft body 43 and moves downward, resulting in the state shown in FIG. 6 (see also FIG. 4). ). The reading roller 31 and the contact image sensor 32 are separated from each other. The apparatus housing 10 a is provided with a positioning plate member 47 for positioning the guide frame body 33. The support shaft body 43 described in FIG. 3 is supported by the support stay 43a, and the guide unit 34 rotates downward around the support shaft body 43 as described above. Since the support shaft body 43 and the support stay 43a are provided on the rear end side of the apparatus housing 10a, the guide unit 34 rotates using the rear end side of the apparatus housing 10a as a rotation fulcrum.

  As a result, both the original mat member 45 and the guide unit 34 rotate downward with the rear end side of the apparatus housing 10a as a rotation fulcrum, so that the guide unit 34 has the original mat member 45 as shown in FIG. The guide unit 34 can be rotated largely without being obstructed by the movement, the reading roller 31 and the contact image sensor 32 can be opened widely, the peripheral surface of the reading roller 31 and the glass of the contact image sensor 32. The plate 32b can be easily cleaned.

  Referring to FIG. 7, as described above, the torsion spring member 44 is attached to the support shaft 43, and one end 44a of the torsion spring member 44 is in contact with the apparatus housing 10a as shown. . On the other hand, although not shown, it is in contact with a side unit (not shown) to which the support stay 43a is attached. That is, both ends of the torsion coil spring 44 are in contact with different frames. As a result, as described above, when the guide unit 34 rotates downward around the support shaft 43, the torsion spring member 44 acts as a buffer member and a stopper, and the user presses the guide unit 34 with his / her hand. Even if no measures are taken, no impact is applied to the guide unit 34 during the rotation. That is, the torsion spring member 44 is compressed as the guide unit 34 rotates downward, and as a result, the downward guide speed of the guide unit 34 is restricted.

  Further, as shown in FIG. 8, a torque limiter 51 may be used. As illustrated, the guide frame body 33 is formed with a cut-and-raised support portion 52, and a torque limiter 51 is attached to the cut-and-raised support portion 52. A gear 53 is attached to the torque limiter 51, and the gear 53 and the rack 103 formed on the support plate portion 102 that is rotatably attached to the apparatus housing 10a (FIG. 1) at the rotation fulcrum 101 are engaged. Thus, a torque limiter mechanism 54 is configured (note that the reading roller 31 is not shown in FIG. 8).

  When the guide unit 34 rotates downward around the support shaft 43, the guide unit 34 is slowly rotated downward by the torsion spring member 44 as described above, but the guide unit 34 is heavy ( In particular, in the document feeder used in a large image forming apparatus, the guide unit 34 is quite heavy), and the torsion spring member 44 alone may not be sufficient.

  However, when the torque limiter mechanism 54 is provided as described above, when the guide unit 34 rotates around the support shaft body 43, the support plate portion 102 also moves around the rotation fulcrum as the guide unit 34 rotates. At this time, the gear 53 rotates while moving along the rack 103. Since the rotational speed of the gear 53 is proportional to the downward movement speed of the guide unit 34, that is, when a torque exceeding a predetermined torque is applied to the torque limiter 51, the rotational speed of the guide unit 34 downward by the torque limiter 51. Will be suppressed. As a result, even the heavy guide unit 34 rotates slowly, and no impact is applied to the guide unit 34.

As is clear from the above description, the automatic document feeder 10 includes a hinge unit that rotatably supports the original mat member 45 on the rear end side of the apparatus housing 10a, and a guide unit 34 provided on the apparatus housing. And a guide unit support means for supporting the guide unit 34 at the rear end side of the apparatus housing 10a. It has guide unit rotation means that rotates with an axis parallel to the direction as a rotation fulcrum, and speed regulation means that regulates the rotation speed of the guide unit 34.

A guide unit that is disposed under the contact image sensor and supports the reading roller, and a document mat member that is positioned under the guide unit and forms the lower surface of the apparatus housing are disposed on the rear end side of the apparatus housing. Since the axis parallel to the original document feeding direction is set as a pivot point and opened on the front end side of the apparatus housing, not only the original document feeder but also other devices including an image reading device (image reading unit) It can also be applied to.

1 is a cross-sectional view illustrating a first embodiment of an automatic document feeder according to the present invention from the front side. FIG. FIG. 2 is a diagram partially showing a contact image sensor and a guide unit from the front side in the automatic document feeder shown in FIG. 1. FIG. 2 is a view partially showing a contact image sensor and a guide unit from the rear side in the automatic document feeder shown in FIG. 1. FIG. 2 is a perspective view of the automatic document feeder shown in FIG. 1 as viewed from below with a document mat member and a guide unit opened. FIG. 5 is a side view for explaining the separation between the reading roller and the contact image sensor in the automatic document feeder shown in FIG. 1. FIG. 2 is a perspective view showing a state where a reading roller and a contact image sensor are separated from each other in the automatic document feeder shown in FIG. 1. In the automatic document feeder shown in FIG. 1, it is a perspective view which shows the support shaft body and the torsion coil member which are the rotation fulcrum of a guide unit from the downward direction. FIG. 2 is a perspective view showing a torque limiter mechanism that regulates the rotation speed of a guide unit in the automatic document feeder shown in FIG. 1.

Explanation of symbols

10 Automatic Document Feeder 11 Document Feeding Tray (Sheet Stacking Unit)
12 Document feeding mechanism (sheet feeding mechanism)
13 Image Reading Device 14 Document Feeding Roller 15 Document Discharge Tray 16 Paper Discharge Roller Pair 31 Reading Roller 32 Contact Type Image Sensor 32a Sensor Housing (Sensor Frame)
33 Guide frame body 34 Guide unit 38 Reading roller holding member 39 Reading roller positioning member 40, 41 Shaft support member 42 Support member 43 Support shaft body 44 Torsion spring member 45 Original mat member 46 Release lever 51 Torque limiter 54 Torque limiter mechanism

Claims (5)

An image on a document that includes a reading roller and a contact image sensor disposed opposite to the reading roller and that passes between the reading roller and the contact image sensor is read by the contact image sensor. In an original feeding apparatus having an image reading unit for obtaining data, and an apparatus housing that supports the image reading unit and sets one of both end sides parallel to the original feeding direction as a front end side and the other as a rear end side ,
A guide unit that is disposed under the contact image sensor and supports the reading roller;
A document mat member which is located under the guide unit and forms a lower surface of the apparatus housing;
Hinge means for rotatably supporting the original mat member on the rear end side of the apparatus housing;
A guide unit support means for rotatably supporting the guide unit on the rear end side of the apparatus housing;
The original mat member and the guide unit are opened on the front end side of the apparatus casing with an axis parallel to the original feeding direction positioned on the rear end side of the apparatus casing as a pivot point. Characteristic document feeder.   2. The document feeding apparatus according to claim 1, wherein the hinge means regulates the rotation of the document mat member at a predetermined rotation angle. The guide unit support means is a guide unit rotation means for rotating the guide unit with a rear end side of the apparatus housing as a rotation fulcrum;
The document feeder according to claim 1, further comprising a speed regulating unit that regulates a rotation speed of the guide unit. The guide unit rotating means includes a support shaft that is disposed on the rear end side of the guide unit and supports the guide unit so as to be rotatable.
4. The document feeding apparatus according to claim 3, wherein the speed regulating means includes a torsion spring member that is attached to the support shaft and is compressed as the guide unit rotates downward.   4. The document feeder according to claim 3, wherein the speed restricting means is a torque limiter mechanism that restricts a torque when the guide unit rotates.

Images