JP6494440B2 - Image reading apparatus and image forming apparatus - Google Patents

Description

  The present invention relates to an image reading apparatus and an image forming apparatus, and more particularly to an image reading apparatus main body provided with a pressing means for pressing an original so as to be opened and closed.

  In general, some image forming apparatuses such as copiers and facsimiles include an image reading unit, and an image reading device that optically reads an original image by the image reading unit. As such an image reading apparatus, there is an ADF (Auto Document Feeder) which is an automatic document feeder configured to feed a document from a stacking tray to a separation unit by a pickup roller, and to feed the document by the separation unit one by one. There is something.

  Further, the original image reading method in the image reading device includes a fixed reading method and a flow reading method. In the conventional image reading device, each is employed independently or in combination. The fixed reading method is a method of reading an original image by placing an original on a platen glass and then scanning the placed original by an image reading unit. In the flow reading method, the image reading means is moved to an image reading position facing a flow reading glass provided on the original conveying path, and the original conveyed by the ADF is passed above the image reading means moved to the image reading position. This is a method of reading a document image. In particular, the flow reading method has high productivity because a large amount of original images can be read continuously.

  Further, in recent years, two image reading units are provided across the document conveyance path, and an image on the front surface (first surface) of the document conveyed by the ADF is imaged on the back surface (second surface) by one image reading device. There is an image reading apparatus that reads the image by the other image reading means. In the case of this type of image reading apparatus, the images on both sides of the original can be read with a single conveyance of the original, so that higher productivity is exhibited.

  Here, the ADF functions as a pressing means for pressing the document placed on the platen glass during fixed reading. The ADF is supported on an upper surface of an image reading apparatus main body (hereinafter referred to as a scanner unit) having an original table glass, an image reading unit, and the like so as to be opened and closed (rotated) with respect to the scanner unit. . Since the ADF as the opening / closing member incorporates many components such as various rollers and motors, the weight is several kg to several tens kg. When it has such a weight, it is not easy to open and close the ADF. Therefore, the image reading apparatus is generally configured to open and close the ADF by an opening and closing mechanism such as a hinge mechanism.

  Further, when reading a document image by the fixed reading method or the flow reading method, in order to read the document image accurately, it is necessary to keep the distance between the image reading means and the document constant, so that when the ADF is closed, Needs to hold the ADF in a closed position with respect to the scanner unit. For this reason, conventionally, for example, a holding unit configured to hold the ADF in a closed position by providing a magnet in the ADF and providing an iron piece in the scanner unit and magnetically engaging the scanner unit and the ADF by magnetic force. The thing provided is proposed (refer patent document 1).

Japanese Utility Model Publication No. 1-174347

  In the case of a conventional image reading apparatus provided with such holding means, when performing a fixed reading, after the holding by the holding means is released, the ADF is moved to an open position for placing the original on the platen glass. Let Here, when releasing the holding of the ADF, in other words, when releasing the holding of the ADF by magnetic engagement, the interlock member is operated by operating the handle that is engaged with the magnet via the interlock member. As the magnet is moved, the ADF is lifted. This releases the magnetic engagement of the ADF.

  By the way, when releasing the magnetic engagement in this way, in addition to the weight of the ADF, a force to release the magnetic engagement, that is, a force to peel off the magnet is required. Great power is required. As a configuration for holding the ADF in the closed position, there is a configuration in which a hook portion is provided in the ADF, and the hook portion is locked to a locked shaft provided in the scanner portion. Even in this configuration, when releasing the holding of the ADF, in addition to the weight of the ADF, a force for releasing the locking of the hook portion is required, so that a large force is required to operate the handle.

  However, when the handle is operated with such a large force, a large force may be applied to the interlocking member that interlocks the magnet and the handle, or the interlocking member that interlocks the hook portion and the handle, and the interlocking member may be deformed. And if an interlocking member deform | transforms in this way, the operativity at the time of canceling | releasing holding | maintenance of ADF will fall.

  Accordingly, the present invention has been made in view of such a current situation, and provides an image reading apparatus and an image forming apparatus capable of improving the operability when releasing the holding of the ADF (pressing means). It is intended.

In the image reading apparatus, the image reading apparatus is provided on the apparatus main body, and is provided with an image reading unit that reads an image on the sheet, and a transparent sheet on which an image is read by the image reading unit. A first position that is rotatable with respect to the member and the apparatus main body and that is open with respect to the transparent member; and a second position that is closed with respect to the transparent member. And a first engaging member provided in the apparatus main body, and a second engaging member provided in the pressing means, and the first engaging member and the first engaging member. A holding means for holding the pressing means in the second position by engaging two engaging members; a holding releasing means provided in the pressing means for releasing the holding of the pressing means by the holding means; Said holding release hand It includes a grip portion, the both ends are rotatably supported on the support portion provided on the retainer means, and the shaft-like connecting member which connects the second engagement member and the handle portion, the handle Restricting means for restricting bending of the connecting member by a predetermined amount or more by contacting the connecting member at a contact position between the second engaging member and the second engaging member, and the axial direction of the connecting member in the grip portion is provided on one end side of the coupling member with respect to the abutting position, the second engagement member is characterized that you have provided to the other end of the coupling member with respect to said contact position Is.

As in the present invention, by regulating the deflection of a predetermined amount or more of the connecting member by the restricting means abutting the consolidated member, it is possible to improve the operability when releasing the holding of the holding means.

1 is a cross-sectional view schematically showing an image forming apparatus according to an embodiment of the present invention. FIG. 3 illustrates a configuration of the image reading apparatus. FIG. 3 is a perspective view of the image reading apparatus. FIG. 3 is a side view showing a state where an ADF provided in the image reading apparatus is opened. The perspective view which shows the state by which the said ADF was open | released. (A) is a figure explaining the suitable arrangement position of the magnetized board provided in the said image reading apparatus, (b) is a figure explaining the arrangement position which is not appropriate. Sectional drawing of the hinge provided in the said image reading apparatus. (A) of the said hinge is a torque diagram around the hinge rotation axis at the time of ADF opening / closing in Adjustment Example 1, and (b) is a torque diagram around the hinge rotation shaft at the time of ADF opening / closing in Adjustment Example 2. The principal part expansion perspective view which shows a state when the said ADF exists in a closed position. The perspective view of the holding | maintenance cancellation | release means provided in the said ADF. (A) is a diagram showing an oblong hole-shaped shaft restricting portion, (b) is a diagram showing a rectangular hole-shaped shaft restricting portion, and (c) is a reverse view with the lower part opened. The figure which shows a U-shaped axis | shaft control part. The perspective view of the holding | maintenance means of another structure provided in said ADF, and a holding | maintenance release means.

  Hereinafter, an image forming apparatus provided with an image reading apparatus according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view schematically showing an image forming apparatus according to the present embodiment. In the following description, the position where the user faces an operation unit (not shown) where various inputs / settings are performed on the image forming apparatus is referred to as the front side of the image forming apparatus, and the back side is referred to as the back side. That is, FIG. 1 shows an internal configuration of the image forming apparatus when the image forming apparatus is viewed from the front side.

  As shown in FIG. 1, the image forming apparatus 100 can form an image reading apparatus 200 that reads an image of a document G stacked on a document stacking tray 221 and a document image read by the image reading apparatus 200 on a sheet S. And an image forming apparatus main body 10 having an image forming unit 20. The image forming apparatus 100 also includes a control unit 50 that controls the image forming operation of the image forming unit 20, the image reading operation of the image reading device 200, and the like.

  The image reading apparatus 200 includes an image reading unit and the like, an image reading apparatus main body (hereinafter referred to as a scanner unit) 210 that reads an image of a document G that is a sheet, and an automatic document that can automatically convey the document G to the scanner unit 210. ADF220 which is a conveyance apparatus (sheet conveyance part) is provided.

  The image forming apparatus main body 10 includes an image forming unit 20 and a sheet feeding unit 30 that feeds the sheet S to the image forming unit 20. Further, the image forming apparatus main body 10 is loaded with a discharge unit 40 having a discharge roller pair 40a for discharging the sheet S on which an image is formed to the outside (outside of the apparatus) of the image forming apparatus main body 10, and the discharged sheet S. And a sheet discharge tray 45.

  The image forming unit 20 includes a photosensitive drum 22 on which a toner image is formed, a laser scanner unit 21 that irradiates the photosensitive drum 22 with laser light, a transfer unit 24 that transfers the toner image to the sheet S, and a toner image. And a fixing unit 25 for fixing. Further, a registration roller pair 11 is disposed upstream of the transfer unit 24 in the sheet conveyance direction. The image forming unit 20 constitutes an image forming unit that forms an image on the sheet S based on image information read from the original G by the image reading device 200. The sheet feeding unit 30 conveys a sheet feeding cassette 31 on which the sheets S are stacked, a feeding roller 32 that feeds the sheets S in the sheet feeding cassette 31, and conveys the sheets S while separating them one by one. It has a roller 33a and a separation roller 33b.

  Next, an image forming operation of the image forming apparatus 100 having such a configuration will be described. When an image reading signal is output from the control unit 50 to the image reading apparatus 200, the document G is conveyed by the ADF 220, and the document is read by a first scanner unit 211 and a second scanner unit 251 described later. Then, the control unit 50 converts the read document image into an electrical signal, and creates image data (image reading information) based on the electrical signal.

  Thereafter, a laser beam corresponding to the image data is emitted from the laser scanner unit 21 to the photosensitive drum 22. At this time, the surface of the photosensitive drum 22 is charged in advance via a charging member (not shown), and an electrostatic latent image is formed by irradiation with a laser beam. The toner image is formed on the photosensitive drum 22 by developing with the toner image 23.

  On the other hand, in parallel with the toner image forming operation on the photosensitive drum 22, a sheet feeding signal is output from the control unit 50 to the sheet feeding unit 30, whereby the sheet S stored in the sheet feeding cassette 31 is fed. Feeded by the roller 32. The sheets S fed by the feeding roller 32 are nipped by a separation nip portion between the conveyance roller 33a and the separation roller 33b, and are separated and conveyed one by one.

  The separated sheet S is corrected for skew by the registration roller pair 11, and then sent to the transfer unit 24 in synchronization with the toner image on the photosensitive drum 22, and then to the transfer unit 24. The toner image on the photosensitive drum 22 is transferred to the sheet S by the transfer unit 24. The sheet S to which the toner image has been transferred is heated and pressed by the fixing unit 25, and the toner image is melted and fixed to the sheet S. The sheet S on which the toner image is fixed is discharged to the sheet discharge tray 45 by the discharge roller pair 40a and is sequentially stacked. When images are formed on both surfaces of the sheet S, after the image is fixed on the first surface of the sheet S, the sheet S is re-conveyed to the registration roller pair 11 via the reverse conveyance path 12. Thereafter, an image is formed on the second surface of the sheet S by repeating the above-described operation.

  Here, as illustrated in FIG. 2, the scanner unit 210 includes a first scanner unit 211 that reads an image on the first surface (front surface) of the document G. Further, on the upper surface of the scanner unit 210, there are a first flow reading glass 212, and a first plate reading glass 212 and an original platen glass 213 which is a transparent member arranged side by side in the sub-scanning direction (left and right direction in FIG. 2). Is provided. As will be described later, the ADF 220 is provided with a second scanner unit 251.

  In the present embodiment, the image reading apparatus 200 reads an original in one of a flow reading mode (ADF original reading mode) and a fixed reading mode (original table glass original reading mode) selected by the user. It is like that. The flow reading mode is a mode in which a document image is read by the ADF 220 through the first scanner unit 211 and the second scanner unit 251. The fixed reading mode is a mode for reading a document image placed on the document table glass 213 by the user while moving the first scanner unit 211 in the sub-scanning direction.

  The ADF 220 is opened and closed (rotated) in the vertical direction with respect to the scanner unit 210 by a hinge unit 270 shown in FIG. 4 (described later) disposed on the back side so that the document table glass 213 can be opened and closed from the front side. ) Supported as possible. In the fixed reading mode, the ADF 220 is rotated upward to open the upper side of the document table glass 213 and place the document on the document table glass 213.

  Here, a CIS (Contact Image Sensor), which is a contact image sensor of an equal magnification optical system, is used for the first scanner unit 211 that is an image reading unit. In the CIS, light is emitted from an LED array as a light source to an image information surface of a document G, and reflected light reflected by the image information surface is imaged on a sensor element to read image information.

  The first scanner unit 211 is connected to a drive belt (not shown). Here, in the case of the flow-reading mode, the driving belt is driven by a motor (not shown) provided in the scanner unit 210 and the first scanner unit 211 is moved to the first reading position A below the first flow-reading glass 212. Let Then, with the first scanner unit 211 stopped at the first reading position A in this way, the original G is moved on the first flow reading glass 212 by the ADF 220 to read the original image.

  In the fixed reading mode, the first scanner unit 211 is moved to the standby position B. Then, after the first scanner unit 211 is moved to the standby position B in this way, the first scanner unit 211 is reciprocated between the standby position B and the terminal position C to be placed on the document table glass 213. Scan the original image. The control unit 50 grasps the position of the first scanner unit 211 from a position sensor (not shown) and the number of rotation pulses of the motor.

  The ADF 220 includes a second scanner unit 251 that reads an image on the second surface (back surface) of the document G. Here, the CIS is used for the second scanner unit 251 similarly to the first scanner unit 211. The second scanner unit 251 is transported on the document transport path H at a second reading position provided in the document transport path H downstream of the first reading position A of the first scanner unit 211 in the document transport direction. A second image reading means for reading an image on the second surface of the original G to be printed. The second reading position is a position facing the second flow reading glass 252.

  As shown in FIGS. 2 and 3, the ADF 220 conveys the document G through the document stacking path 221 on which the document G for flow reading is stacked and the document conveyance path H when performing the flow reading. And a document conveying section 222. The ADF 220 has a document discharge unit 223 on which the flow-read original G is discharged and stacked. The ADF 220 is configured such that the original G can be pressed by a resin plate (not shown) so that the original G placed on the original table glass 213 does not move during fixed reading.

  As shown in FIG. 2, the document conveying unit 222 includes a document feeding roller 231 that feeds the document G stacked on the document stacking tray 221, a separation roller pair 232 that separates the document G one by one, and a separation roller 231. A first conveying roller pair 233 for pulling out the original G. Further, the document conveyance unit 222 includes a second conveyance roller pair 234 that conveys the document G, a third conveyance roller pair 236, a fourth conveyance roller pair 238, and a fifth conveyance roller pair 240.

  The document conveying unit 222 is disposed between the second conveying roller pair 234 and the third conveying roller pair 236 and corrects (corrects) the skew of the original G. The first platen It has a roller 237 and a discharge roller pair 241. In addition, the document conveying section 222 is disposed so as to face the second flow reading glass 252 and has a second platen roller 239 that conveys the document G.

  The first platen roller 237 is for holding the document G from the second surface side and suppressing the document G from being lifted from the first flow reading glass 212. The first platen roller 237 is a first scanner positioned at the first reading position A, that is, directly above the first flow reading glass 212 positioned between the third conveying roller pair 236 and the fourth conveying roller pair 238. The unit 211 is disposed so as to face the unit 211. The first platen roller 237 is rotationally driven by a motor (not shown).

  Further, the discharge roller pair 241 is disposed downstream of the fifth transport roller pair 240, and discharges the original G after image reading to the original discharge unit 223. The second platen roller 239 is disposed so as to face the second flow reading glass 252 and is used for conveying the document G while holding the original G from the first surface side and keeping the distance from the second flow reading glass 252 constant. Is.

  Next, an image reading operation by the image reading apparatus 200 having such a configuration will be described. First, the document G placed on the document stacking tray 221 is fed by the document feeding roller 231 and separated one by one at the separation nip portion of the separation roller pair 232. The separated document G is pulled out by the first transport roller pair 233 and then transported to the nip portion of the registration roller pair 235 by the second transport roller pair 234.

  Here, when the document G reaches the nip portion of the registration roller pair 235, the registration roller pair 235 is in a stationary state, whereby the document G is in a state where the leading end is in contact with the nip portion. Stop. In this state, the document G is bent and curved by pushing the rear end of the document G by a predetermined amount by the second conveyance roller pair 234 on the upstream side in the document conveyance direction.

  Here, when the document G is skewed, the leading edge of the document G is inclined with respect to the main scanning direction (the width direction orthogonal to the document conveyance direction), but the stiffness (rigidity) of the document G due to the above-described curvature. ), The leading edge of the document follows the nip line of the registration roller pair 235 parallel to the main scanning direction. As a result, the inclination of the leading edge of the document is eliminated, and the skew of the document G is corrected.

  After the skew correction, the conveyance of the original G by the registration roller pair 235 is started, and the original G is further conveyed downstream by the third conveyance roller pair 236 to reach the image reading position on the first flow reading glass 212. To reach. Then, the first scanner unit 211 reads an image on the first side of the document G at a predetermined speed. Thereafter, the original G is conveyed by the fourth conveying roller pair 238. Here, if the user instructs to read the second side of the document G, the controller 50 controls the image reading position on the second flow reading glass 252 after the first side reading described above. Then, the second scanner unit 251 reads the image on the second side of the document G at a predetermined speed.

  Further, the original G after image reading is discharged to the original discharge unit 223 by the fifth conveying roller pair 240 and the discharge roller pair 241. Then, the above-described operation is repeated until there are no more documents G placed on the document stacking tray 221. The presence / absence of the document G placed on the document stacking tray 221 can be detected by a sensor (not shown).

  Incidentally, as shown in FIGS. 4 and 5, a front abutting portion 263 and a back abutting portion 264 are provided on the bottom surface of the ADF 220. The front side abutting part 263 and the back side abutting part 264 are disposed so as to abut on the front side abutting area 212a and the back side abutting area 212b on the first flow reading glass 212 shown in FIG. . Then, the abutting portions 263 and 264 are brought into contact with the abutting areas 212a and 212b on the first flow reading glass 212, whereby the document transport path H is provided between the first flow reading glass 212 and the first platen roller 237. A predetermined gap that forms a part of is formed.

  Here, when the predetermined gap is not formed and the interval is widened, the conveyed original G floats upward with respect to the first flow reading glass 212, and the read image becomes blurred. When the abutting portions 263 and 264 are in contact with only one of the front-side abutting region 212a and the rear-side abutting region 212b, so-called one-side contact, the gap is in the horizontal direction in FIG. It becomes non-uniform in the scanning direction. In this case, a conveyance resistance difference occurs in the main scanning direction with respect to the conveyed document G, and as a result, skew of the document G occurs, which adversely affects the geometric characteristics of the read image.

  Therefore, in order to avoid such an image defect, both the front side abutting part 263 and the back side abutting part 264 are surely brought into contact with the first flow reading glass 212 and the contact state is maintained. There is a need. Therefore, in the present embodiment, a magnet 261 which is an example of an engaging member is provided on the front side of the bottom surface of the ADF 220, and a magnetized plate which is a magnetic member such as an iron plate which is an example of a member to be engaged on the front side of the upper surface of the scanner unit 210. 262 is provided.

  Here, the magnet 261 is provided on the bottom surface of the rotation end of the ADF 220, and the magnetized plate 262 is disposed at a position corresponding to the position of the magnet 261 when the ADF 220 is closed. For this reason, when the ADF 220 is closed, the magnet 261 and the magnetized plate 262 are magnetically engaged, and the ADF 220 can be stably held. That is, in the present embodiment, as shown in FIG. 4, the magnet 261 and the magnetized plate 262 constitute a holding means 260 that holds the ADF 220 in the closed position. In the closed position, the ADF 220 covers the document table glass 213 and presses the document placed on the document table glass 213.

  Here, as shown in FIG. 6A, the magnetized plate 262 overlaps with the first flow reading glass 212 in the sub-scanning direction which is the left-right direction (original transport direction) in FIG. The one scanner unit 211 is arranged at a position corresponding to the position in the sub-scanning direction. As a result, when closed, the ADF 220 is held around the first flow reading glass 212 in the sub-scanning direction, and the first flow of the front-side butting portion 263 and the back-side butting portion 264 described above. The contact on the reading glass 212 is strong and stable.

  Note that when the magnet 261 and the magnetized plate 262 are arranged at a position away from the first flow reading glass 212 in the sub-scanning direction as shown in FIG. 6B, the first flow reading glass. In the vicinity of 212, the influence of the holding force due to magnetic engagement becomes small. In this case, due to the deflection and warping of the bottom surface of the ADF 220, the front side abutting part 263 and the back side abutting part 264 may be lifted from the first flow reading glass 212, and the above-described image defects may occur.

  Thus, the arrangement of the magnet 261 and the magnetized plate 262 as shown in FIG. 6B is not preferable. Therefore, as shown in FIG. 6A, at least a part of the front-side butting area 212a and the back-side butting area 212b is included in the main scanning direction projection area E of the magnet 261 and the magnetized plate 262. Is preferable.

  In the present embodiment, as shown in FIG. 5, the ADF 220 is provided with a holding release lever 281 that is a handle for releasing the holding of the ADF 220 by the magnet 261 and the magnetized plate 262. The holding release lever 281 forms a part of holding release means 280 for releasing the holding of the ADF 220 shown in FIG. 10 described later, and the user releases the holding of the ADF 220 by pushing up the holding releasing lever 281 from below. . Here, the holding release lever 281 is disposed at the center portion in the sub-scanning direction on the rotation end side of the ADF 220, and by disposing the holding release lever 281 at such a position, the user can easily operate. It is supposed to be.

  By the way, in the case of the fixed reading mode as described above, the ADF 220 is rotated upward, and the ADF 220 is moved to the open position that is the first position where the original table glass 213 can be opened and the original can be placed. The original is placed on the platen glass 213 in the moved state. Note that a hinge part 70 shown in FIG. 4 is provided at the back end, which is one end part of the scanner part 210, so that the ADF 220 can be rotated. The hinge part 270 causes the ADF 220 to be connected to the scanner part 210. Is supported so as to be rotatable (movable).

  Here, as shown in FIG. 7, the hinge portion 270 has a hinge rotation shaft 271, and the ADF 220 rotates about the hinge rotation shaft 271 with respect to the scanner portion 210. The hinge portion 270 includes a hinge spring A272 and a hinge spring B273 inside thereof, and the hinge spring A272 and the hinge spring B273 generate a hinge torque that is applied in a direction in which the ADF 220 is rotated upward. Here, the hinge torque that affects the operability when the user opens the ADF 220 can be adjusted by the spring force of the hinge spring A272 and the hinge spring B273 and the combination thereof.

  Next, an example of adjusting the hinge torque will be described with reference to FIG. 8 which is a torque diagram around the hinge rotation shaft 271 when the ADF 220 is opened and closed. (A) of FIG. 8 is the hinge adjustment example 1. FIG. In this hinge adjustment example 1, in the range where the opening / closing angle θ of the ADF 220 shown in FIG. 4 is less than 20 °, adjustment is performed so that the own weight torque acting in the closing direction due to the own weight of the ADF 220 is larger than the hinge torque. Has been. For this reason, when the opening / closing angle θ of the ADF 220 is less than 20 °, the ADF 220 is closed by its own weight.

  Further, in the hinge adjustment example 1, in the range where the opening / closing angle θ is 20 ° or more, the self-weight torque of the ADF 220 and the load torque due to the friction in the hinge portion 270 generated when the opening / closing angle θ becomes 20 ° or more (indefinite) And the sum total with the figure are adjusted so as to balance the hinge torque. For this reason, the ADF 220 can be kept stationary while maintaining its opening / closing angle θ, and at that time, support by an external force is unnecessary. Therefore, in the case of hinge adjustment example 1, when placing the document G on the platen glass 213 for fixed reading, if the user opens the ADF 220 with an opening / closing angle θ of 20 ° or more, the user moves his / her hand from the ADF 220. It is possible to place the original G by releasing it.

  FIG. 8B is a hinge adjustment example 2. In this hinge adjustment example 2, when the opening / closing angle θ of the ADF 220 is less than 20 °, the self-weight torque that works in the closing direction due to the self-weight of the ADF 220 is adjusted to be smaller than the hinge torque. For this reason, when the ADF 220 is opened, the ADF 220 automatically rotates upward even when the opening / closing angle θ is less than 20 °. Further, in the hinge adjustment example 2, in the range where the opening / closing angle θ is 20 ° or more, the self-weight torque of the ADF 220 and the load torque due to the friction inside the hinge portion 270 generated when the opening / closing angle θ becomes 20 ° or more ( (Not shown) is adjusted to balance the hinge torque. For this reason, in the hinge adjustment example 2, the ADF 220 can remain stationary while maintaining the opening / closing angle θ in a range where the opening / closing angle θ is 20 ° or more, and support by an external force is not necessary at that time.

  In this embodiment, at the time of image reading by fixed reading, the ADF 220 is rotated upward by the hinge portion 270 when the holding of the ADF 220 is released to expose the original table glass 213. For this reason, in the present embodiment, the hinge torque is adjusted by the hinge adjustment example 2.

  Here, when the hinge torque is adjusted in this way, the ADF 220 does not close due to its own weight. Therefore, after placing the document on the platen glass 213, the user applies a force to the ADF 220 in the closing direction to close the ADF 220. When the ADF 220 is closed in this manner, the magnet 261 and the magnetized plate 262 are engaged with each other, whereby the ADF 220 is held in the closed position that is the second position for pressing the document.

  Further, when the ADF 220 is opened, the holding of the ADF 220 is released by releasing the engagement between the magnet 261 and the magnetized plate 262 by pushing up the holding release lever 281 described above. When the holding of the ADF 220 is released in this way, the ADF 220 opens to a position with an opening / closing angle of 20 ° by the hinge torque. That is, in the present embodiment, the ADF 220 can be opened to the position of the opening / closing angle of 20 ° only by pushing up the holding release lever 281 by the hinge torque. For this reason, the user can open the ADF 220 without burdening the weight of the ADF 220, and the operability is improved.

  Next, a configuration for releasing the holding of the ADF 220 by operating the holding release lever 281 will be described. FIG. 9 is a perspective view showing a state in which the ADF 220 is held in the closed position so as to cover the platen glass 213. Here, as described above, the ADF 220 includes the holding release lever 281 and the magnet 261, and the holding release lever 281 and the magnet 261 are connected by the rotation shaft (shaft-like member) 282 that is a connecting member. Yes. As shown in FIG. 10, both ends of the rotation shaft 282 are supported by shaft support portions 283 formed in the ADF housing 220a. In addition, a shaft restricting portion 284 is formed in the ADF casing 220a, and the rotating shaft 282 is inserted through the shaft restricting portion 284.

  When releasing the holding of the ADF 220, the user pushes up the holding release lever 281 as described above. Here, when the holding release lever 281 is pushed up, the rotation shaft 282 rotates in the direction of arrow E integrally with the holding release lever 281. Further, when the rotating shaft 282 rotates, the magnet 261 rotates in the direction of arrow E integrally with the rotating shaft 282. When the magnet 261 rotates in this way, the magnet 261 is magnetically coupled to the magnetized plate 262. The engagement is released and the holding of the ADF 220 is released. That is, in the present embodiment, the holding release lever 281, the rotation shaft 282, and the shaft restricting unit 284 constitute the holding release means 280 that releases the holding of the ADF 220.

  When the holding of the ADF 220 is released, the ADF 220 is automatically opened to the position of the opening / closing angle of 20 ° by the hinge portion 270 whose hinge torque has been adjusted by the hinge adjustment example 2 described above. The original can be placed on the document. Thus, according to the present embodiment, the holding of the ADF 220 can be released and the ADF 220 can be opened upward only by pushing up the holding release lever 281, and the document can be placed on the platen glass 213. It becomes.

  Here, as described above, for the sake of operability, the holding release lever 281 is disposed at the center of the rotation end of the ADF 220 in the sub-scanning direction. In order to avoid reading image defects, the magnet 261 is arranged at a position overlapping the first flow reading glass 212 in the sub-scanning direction. In this case, the rotation shaft 282 has a length that is approximately half the length of the ADF 220 in the sub-scanning direction. The holding release lever 281 is attached to one end side of the center side in the sub-scanning direction of the rotating shaft 282, in other words, the axial direction of the rotating shaft 282, and the magnet 261 is the other end side of the rotating shaft 282 in the sub-scanning direction. Attached to. Further, both ends of the rotation shaft 282 are rotatably supported by a shaft support portion 283.

  In the case of this configuration, when the user pushes up the holding release lever 281, a force acts on the rotating shaft 282 in the direction of bending upward. Here, the image reading apparatus 200 according to the present embodiment is capable of reading an A3 size document. In this case, the length of the rotating shaft 282 is increased. When the rotation shaft 282 becomes longer in this way, when the engagement force between the magnet 261 and the magnetized plate 262 is large, when the user pushes up the holding release lever 281, the rotation shaft 282 is bent upward. In addition, when bending becomes large, the frictional resistance with respect to the rotating shaft 282 in the shaft support part 283 will increase. When the frictional resistance is increased, a rotation failure of the rotation shaft 28 occurs. Therefore, in order to rotate the rotation shaft 282, a large force must be applied to the holding release lever 281 and the operability is deteriorated. .

  Therefore, in this embodiment, as described above, the ADF housing 220a is formed with the shaft restricting portion 284 having a hole shape larger than the diameter of the turning shaft 282, for example, and the turning shaft 282 is formed on the shaft restricting portion 284. Is inserted. Thus, when the rotation shaft 282 is largely bent upward as the holding release lever 281 is pushed up, the rotation shaft 282 comes into contact with the inner peripheral surface of the shaft restricting portion 284, and the rotation shaft 282 The bending (deformation) of a predetermined amount or more can be regulated. In addition, by restricting the deflection of the rotation shaft 282 by a predetermined amount or more, the frictional resistance of the shaft support portion 283 with respect to the rotation shaft 282 can be reduced, and the holding release lever 281 can be pushed up. It is possible to prevent the rotation failure of the rotation shaft 282.

  As described above, in the present embodiment, when the holding shaft release lever 281 is pushed up, if the rotating shaft 282 is bent upward, the shaft restricting portion 284 restricts the deformation of the rotating shaft 282. Yes. Thereby, it is possible to prevent the rotation failure of the rotating shaft 28 during the push-up operation of the holding release lever 281 and improve the operability.

  As described above, the shaft restricting portion 284 has a hole shape through which the rotating shaft 282 is inserted. Here, when the shaft restricting portion 284 is a fitting hole having a diameter substantially the same as the diameter of the rotating shaft 282, the deformation of the rotating shaft 282 as described above is completely restricted. However, in reality, it is conceivable that the rotation shaft 282 is not straight but slightly deformed due to distortion during molding of the ADF housing 220a, deformation of the ADF housing 220a due to biasing of the hinge torque, and the like.

  In consideration of this, when the shaft restricting portion 284 is a fitting hole as described above, slight deformation of the rotating shaft 282 is not allowed, and therefore, when the rotating shaft 282 rotates, There is a risk of generating large frictional resistance. In this case, it may be difficult for the user to push up the holding release lever 281.

  For this reason, in the present embodiment, as described above, the shaft restricting portion 284 has the predetermined clearance as shown in FIG. 10 when the holding release lever 281 is not pushed up. It is formed in a hole shape larger than the diameter. This gap is formed above the rotation shaft 282 that is the direction in which the holding release lever 281 is pushed up (operation direction). In addition, this gap is formed so as to satisfy both the restriction of large deformation of the rotation shaft 282 by pushing up the holding release lever 281 of the rotation shaft 282 and the slight deformation allowance inherent in the rotation shaft 282. Has been.

  By forming such a gap between the shaft restricting portion 284 and the rotation shaft 282, the rotation shaft 282 can bend upward when the holding release lever 281 is pushed up. In addition, the shaft restricting portion 284 can be contacted before being largely bent, and deformation of the rotating shaft 282 can be restricted. In addition, when the rotating shaft 282 contacts the shaft restricting portion 284 in this way, the portion that contacts the shaft restricting portion 284 is a part of the rotating shaft 282, and therefore, friction generated between the shaft restricting portion 284 and the shaft restricting portion 284. The resistance is small and the influence on the rotational load of the rotating shaft 282 is small.

  Here, the shape of the shaft restricting portion 284 has a predetermined gap with the rotating shaft 282 when the holding release lever 281 is not pushed up, that is, when the holding release lever 281 is not operated. Any shape is acceptable. Examples of the shape of the shaft restricting portion 284 include an oblong hole as shown in FIG. 11A and a rectangular hole as shown in FIG.

  When the shaft restricting portion 284 has an oblong hole shape shown in FIG. 11A, when the holding release lever 281 is not operated, the rotation shaft 282 is in the direction in which the rotation shaft 282 bends. A predetermined gap g1 is formed in the direction, and a gap g2 is formed on both sides of the rotation shaft 282. Here, the shaft restricting portion 284 is formed such that the size of the gap g2 on both sides is smaller than the predetermined gap g1, and the holding release lever is formed by forming the shaft restricting portion 284 in this way. By operating 281, the rotation shaft 282 is surely bent upward.

  Further, when the shaft restricting portion 284 is an oblong hole, the upper portion of the inner surface of the shaft restricting portion 284 serving as a contact surface that contacts the rotating shaft 282 has a curved shape. For this reason, even when the rotating shaft 282 is bent upward, the rotating shaft 282 can be brought into contact with the upper end of the inner surface of the shaft restricting portion 284 without shifting. In order to make the rotation shaft 282 abut on the upper end of the inner surface of the shaft restricting portion 284 without shifting in this way, the shaft restricting portion 284 includes the gap between the inner surface and the turning shaft 282. It is preferable to have a shape such that the predetermined gap g1 is the largest.

  Further, when the holding release lever 281 is pushed up, the rotation shaft 282 is bent upward, but is not greatly bent downward. Therefore, it is not necessary to regulate the lower side of the rotating shaft 282. Therefore, as shown in FIG. 11 (c), the shape of the shaft restricting portion 284 is opposed to the upper portion that contacts the rotating shaft 282 on the inner surface. An inverted U-shape in which a lower portion is opened may be used.

  The position of the shaft restricting portion 284 may be anywhere between the holding release lever 281 and the magnet 261 as long as it does not impair operability. This is effective against deformation of the rotating shaft 282 caused by pushing up the lever 281. Further, the position of the shaft restricting portion 284 is preferably determined in consideration of the operability as described above, the rigidity of the ADF housing 220a, and the like.

  As described above, in the present embodiment, when the holding of the ADF 220 is released, when the turning shaft 282 is bent by the operation of the holding release lever 281, the turning shaft 282 is brought into contact with the shaft restricting portion 284. Thus, the bending of the rotation shaft 282 over a predetermined amount is restricted. By restricting the amount of bending of the rotation shaft 282 in this way, the frictional resistance of the shaft support portion 283 with respect to the rotation shaft 282 can be reduced, and the operability when releasing the holding of the ADF 220 can be reduced. Can be improved.

  In the present embodiment, the hinge portion 270 has a hinge torque (elastic force) that rotates the ADF 220 upward to a predetermined angle when the holding of the ADF 220 by the holding means 260 is released. Thus, when the holding release lever is operated to release the holding by the holding means 260, the ADF 220 that has been in the closed position until then can be moved to the open position. In other words, according to the present embodiment, the ADF 220 can be released from the release and the ADF 220 can be moved to the open position only by pushing up the hold release lever. Therefore, when the ADF 220 is moved to the open position, Can be reduced.

  In the present embodiment, the ADF 220 is provided with the magnet 261 and the scanner unit 210 is provided with the magnetized plate 262, but the present invention is not limited to this. For example, a magnetized plate 262 may be provided in the ADF 220, and a magnet 261 may be provided in the scanner unit 210. That is, one of the magnet 261 and the magnetized plate 262 may be provided in the scanner unit 210, and the other of the magnet 261 and the magnetized plate 262 may be provided in the ADF 220. Moreover, it is good also as a structure which provided the magnet in each of ADF and a scanner part.

  In the present embodiment, the configuration in which the ADF 220 and the scanner unit 210 are magnetically engaged is described as the configuration of the holding unit, but the present invention is not limited to this. For example, as shown in FIG. 12, the holding means is configured such that a hook member 291 is provided as an engaging member in the ADF 220 and a locking shaft 292 is provided as an engaged member in the scanner unit 210. The same effect as when there was.

  In this configuration, as described above, when the user pushes up the holding release lever 281, the rotation shaft 282 rotates in the direction of arrow E, and the hook member 291 rotates in the direction of arrow E integrally with the rotation shaft 282. . When the hook member 291 rotates in this manner, the hook member 291 is released from the engagement (engagement) with the engagement shaft 292 that is the member to be engaged, and the holding of the ADF 220 is released.

  It should be noted that the effects described in the present embodiment only list the most preferable effects resulting from the present invention, and the effects according to the present invention are not limited to those described in the present embodiment. Further, although an electrophotographic image forming apparatus has been described as an example of an image forming apparatus provided with an image reading apparatus to which the present invention is applied, the present invention is not limited to this. For example, the image reading apparatus to which the present invention is applied may be provided in an ink jet type image forming apparatus that forms an image on a sheet by ejecting ink liquid from a nozzle.

  In the present embodiment, the image reading apparatus has been described that reads images on both sides of a document with two scanner units. However, the present invention is not limited to this. For example, an image reading apparatus configured to read an image on both sides of a document by one scanner unit by providing a document reversing mechanism inside the ADF, inverting a document on which one image is read, and transporting the document to an image reading position. Can be used.

  Furthermore, in the above description, although the connection member demonstrated the case where it had an axial shape, this invention is not limited to this. For example, the connection member may have a plate-like shape to which one of a holding release lever, a magnet and a hook member is attached and whose both ends are pivotally supported.

DESCRIPTION OF SYMBOLS 20 ... Image forming part, 100 ... Image forming apparatus, 200 ... Image reading apparatus, 210 ... Scanner part (image reading apparatus main body), 211 ... First scanner unit (image reading means), 212a ... Front side abutting area, 212b ... Back side abutting area, 213... Glass plate (transparent member), 220... ADF (pressing means), 220 a... ADF housing, 222. 262 ... Magnetized plate (engaged member), 263 ... Front side abutting part, 264 ... Back side abutting part, 270 ... Hinge part, 271 ... Hinge rotation shaft, 280 ... Holding release means, 281 ... Holding release lever , 282... Rotating shaft, 283... Shaft supporting portion, 284... Shaft restricting portion, 291... Hook member (engaging member), 292. , S ... Sea

Claims (12)

An image reading means provided in the apparatus body for reading an image of a sheet;
A transparent member provided on an upper surface of the apparatus main body, on which a sheet on which an image is read by the image reading unit is placed;
It is rotatable with respect to the apparatus main body , and moves between a first position that is an open position with respect to the transparent member and a second position that is a closed position with respect to the transparent member. Possible holding means,
A first engagement member provided in the apparatus main body, and a second engagement member provided in the pressing means, wherein the first engagement member and the second engagement member are engaged with each other. Holding means for holding the pressing means in the second position;
Holding release means provided on the pressing means and releasing the holding of the pressing means by the holding means,
The holding release means is
A handle,
A shaft-like connecting member that rotatably supports both ends of the support portion provided in the pressing means and connects the handle portion and the second engaging member;
Regulation means for regulating deflection of the coupling member by a predetermined amount or more by contacting the coupling member at a contact position between the handle portion and the second engagement member ;
In the axial direction of the connecting member, the grip portion is provided on one end side of the connecting member with respect to the contact position, and the second engagement member is provided on the other end side of the connecting member with respect to the contact position. An image reading apparatus.   The image reading apparatus according to claim 1, wherein a predetermined gap is formed between the connecting member and the restricting unit when the handle portion is not operated. 2. The engagement between the first engagement member and the second engagement member is released when the connecting member rotates due to the operation of the handle portion. Or the image reading apparatus of 2. The restricting means is a direction in which the connecting member bends in a gap between the inner surface of the restricting means and the connecting member when the connecting member is inserted and the handle portion is not operated. the image reading apparatus according to any one of claims 1 to 3 gaps to be formed and having a largest made such shapes. The image reading apparatus according to claim 4 , wherein a contact surface having a curved shape that contacts the connection member when the connection member is bent is formed on the inner surface of the restricting unit. . The inner surface of the restricting means has a shape in which a contact surface that comes into contact with the connection member when the connection member is bent is formed and a portion that faces the contact surface is opened. The image reading apparatus according to claim 4 , wherein: Provided in the apparatus main body, comprising a hinge portion that rotatably supports the pressing means, and moves the pressing means to the first position or the second position;
The said pressing means is rotated upward to a predetermined angle by the elastic force of the said hinge part, if it releases | releases from the holding | maintenance by the said holding means, The any one of Claim 1 thru | or 6 characterized by the above-mentioned. Image reading device. The holding release means and the second engagement member are provided at the rotation end of the pressing means,
Claims 1 to 7, characterized in that the upper surface and the pressing means of the apparatus main body at a position corresponding to the second engagement member when in the second position, the first engagement member is provided The image reading apparatus according to any one of the above. One of the first engagement member and the second engagement member is a magnet, and the other of the first engagement member and the second engagement member is a magnetic member that magnetically engages with the magnet. the image reading apparatus according to any one of claims 1 to 8, characterized in. One of the first engagement member and the second engagement member is a hook member, and the other of the first engagement member and the second engagement member is a locked member to which the hook member is locked. the image reading apparatus according to any one of claims 1 to 8, characterized in that there. The pressing means includes a sheet conveying unit that conveys a sheet,
The image reading means is movable to a first reading position for reading an image of a sheet placed on the transparent member and a second reading position for reading an image of a sheet conveyed by the sheet conveying unit,
The first engagement member is disposed so as to overlap the image reading unit located at the second reading position in the moving direction of the image reading unit,
The grip portion includes an image reading apparatus according to any one of claims 1 to 1 0, characterized in that provided in the central portion of the pressing means in the direction of movement. An image reading apparatus according to any one of claims 1 to 1 1 reads an image of the sheet, that and an image forming unit for forming an image based on image information read by the image reading apparatus An image forming apparatus.

Images