JP6488850B2 - Image reading apparatus and image forming apparatus - Google Patents

Description

  The present invention relates to an image reading apparatus and an image forming apparatus in which an ADF such as a printer, a copying machine, or a facsimile is opened and closed with respect to a scanner.

  In a general MFP (multifunction printer), an image reading device (scanner) is installed on a printer, and an ADF (automatic document feeder) is further provided thereon. As an image reading method, an ADF is mounted on an image reading device through a hinge having an opening / closing mechanism, and a sheet through method in which an image is read by a reading unit fixed while conveying an original set on a document table. It is already known that there is a flat bed system in which an original is set on a contact glass of an image reading apparatus and an image is read by moving reading means in the image reading apparatus.

  In the latter method, when the inclination of the ADF pressure plate sheet with respect to the contact glass surface is within a range of 20 degrees to 60 degrees, the ADF is free-stopped by the hinge. When the inclination of the pressure plate sheet is less than about 20 degrees, the ADF falls by its own weight, and a large impact sound is generated when it collides with the scanner, so that the user may feel uncomfortable.

  As a countermeasure, there is a method of reducing an impact sound at the time of dropping by putting an impact relaxation member (damper) inside the hinge. For example, even if the piston damper 210 shown in FIG. 13 is inserted into the hinge, the size of the piston damper 210 is too large to enter the hinge 211. For this reason, as shown in FIG. 14, in order to insert piston damper 210 'into the inside of hinge 211', it is necessary to enlarge the size of a hinge.

  However, since the impact mitigating member is placed inside the hinge, the hinge itself becomes large, and the scanner that supports the hinge inevitably becomes large, and there is a possibility that the apparatus cannot be downsized. Further, when the damper is inserted without enlarging the hinge, only a small damper having a small impact relaxation effect can be inserted, so that there is a problem that the effect may be less effective for reducing the impact sound.

  Patent Document 1 discloses a configuration in which a hole is provided in the upper surface of the scanner without inserting a member inside the hinge and the member is inserted into the provided hole. In the open / close detection unit 260 described in Patent Document 1, the open / close detection lever 261a moves up and down through the through hole 200b provided in the upper surface member 200a of the document reading unit 200, and the open / close angle of the document pressing plate of the automatic document feeder is determined. Is to be detected. However, what is described in Patent Document 1 is not intended to reduce the impact sound, and does not describe a configuration in which a damper for reducing the impact sound is provided.

  The present invention has been made to solve such a problem. An image reading apparatus and an image forming apparatus capable of reducing the impact sound generated when the ADF is closed without increasing the size of the apparatus. The purpose is to provide.

In order to achieve the above object, an image reading apparatus according to the present invention includes an automatic document conveyance unit having a hinge having an opening / closing mechanism and an image reading unit for reading an image. The swinging member swings in accordance with the opening / closing operation of the automatic document feeder, and the swinging member for detecting the opening / closing angle of the automatic document feeder is engaged with the swinging member to close the automatic document feeder. possess the impact damper to cushion the impact of the automatic document feeder and the image reading unit, the said shock-absorbing member, the force to alleviate the impact only when moving in the automatic document feeder is closed direction work, from a position where the automatic document feeder is naturally falling force to alleviate the impact, characterized in Rukoto started working.

  According to the present invention, it is possible to reduce the impact sound generated when the ADF is closed without increasing the size of the apparatus.

1 is a cross-sectional view illustrating a schematic configuration of an image forming apparatus according to an embodiment of the present invention. 1 is a perspective view of an image reading apparatus according to an embodiment of the present invention. FIG. 2 is a perspective view of an image reading unit of the image reading apparatus according to the embodiment of the present invention. 1 is a cross-sectional view of an image reading apparatus according to an embodiment of the present invention as viewed from the side. 1 is a cross-sectional view of an image reading apparatus according to an embodiment of the present invention as viewed from the side. 1 is a cross-sectional view of an image reading apparatus according to an embodiment of the present invention as viewed from the side. 1 is a cross-sectional view of an image reading apparatus according to an embodiment of the present invention as viewed from the side. 1 is a cross-sectional view of an image reading apparatus according to an embodiment of the present invention as viewed from the front. 1 is a cross-sectional view of an image reading apparatus according to an embodiment of the present invention as viewed from the front. 1 is a cross-sectional view of an image reading apparatus according to an embodiment of the present invention as viewed from the side. 1 is a cross-sectional view of an image reading apparatus according to an embodiment of the present invention as viewed from the side. FIG. 5 is a cross-sectional view of a case where a swing member is provided in an automatic document feeder in the image reading apparatus according to the embodiment of the present invention as viewed from the side. It is the schematic in the case of inserting a piston damper in the conventional hinge. It is the schematic in the case of inserting a piston damper in the conventional hinge.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  As shown in FIG. 1, an image forming apparatus 1 according to the present embodiment includes an apparatus main body 1M having a paper feeding section 2, an image forming section 3, and an image reading section 4, and an automatic document arranged on the apparatus main body 1M. It is a digital multi-function peripheral provided with a transport unit 5 (hereinafter also referred to as ADF). The image reading unit 4 and the automatic document feeder 5 constitute an image reading device 6.

  The paper feed unit 2 includes a plurality of stages of paper feed cassettes 21A, 21B, and 21C that can store cut sheet-like transfer papers P in a stacked state. In each of the paper feed cassettes 21A, 21B, and 21C, for example, transfer paper P (for example, white paper) having a sheet size selected in advance from a plurality of sheet sizes is accommodated in the vertical or horizontal paper feeding direction. ing.

  The paper feeding unit 2 includes paper feeding devices 22A, 22B, and 22C that sequentially pick up and separately transfer the transfer paper P stored in the paper feeding cassettes 21A, 21B, and 21C from the respective uppermost layers. The paper feeding unit 2 is further provided with various rollers 23 and the like. By these, the transfer paper P fed from each of the paper feeding devices 22A, 22B, and 22C is transferred to a predetermined image forming position of the image forming unit 3. A sheet feeding path 24 is formed to convey the sheet.

  The image forming unit 3 includes an exposure device 31, photosensitive drums 32K, 32Y, 32M, and 32C, and a developing device filled with black (K), yellow (Y), magenta (M), and cyan (C) toners. 33K, 33Y, 33M, and 33C. The image forming unit 3 includes a primary transfer unit 34, a secondary transfer unit 35, and a fixing unit 36.

  For example, the exposure device 31 generates the laser light L for exposure of each color based on the image read by the image reading device 6. Further, the exposure device 31 exposes the photosensitive drums 32K, 32Y, 32M, and 32C of the respective colors with laser light, and static images of the respective colors corresponding to the read images on the surface layer portions of the photosensitive drums 32K, 32Y, 32M, and 32C. An electrostatic latent image is formed.

  The developing devices 33K, 33Y, 33M, and 33C supply thin layer toner to the corresponding photosensitive drums 32K, 32Y, 32M, and 32C so as to make the electrostatic latent image visible with the toner. Is supposed to do.

  The image forming unit 3 primarily transfers the toner image developed on the photosensitive drums 32K, 32Y, 32M, and 32C to the primary transfer unit 34, and the toner image is transferred by the secondary transfer unit 35 adjacent to the primary transfer unit 34. Secondary transfer is performed on the transfer paper P. Further, the image forming unit 3 heats and pressurizes the toner image secondarily transferred onto the transfer paper P and melts it, and fixes the color image on the transfer paper P for recording.

  The image forming unit 3 has a transport path 39A for transporting the transfer paper P carried from the paper feed unit 2 through the paper feed path 24 to the secondary transfer unit 35 side. In the transport path 39A, first, the transport timing and transport speed of the transfer paper P are adjusted by the registration roller pair 37. The transfer sheet P passes through the secondary transfer unit 35 and the fixing unit 36 in synchronization with the belt speed at the primary transfer unit 34 and the secondary transfer unit 35 and is then discharged onto the discharge tray 38. It is like that.

  The image forming unit 3 also has a manual paper feed path 39B that feeds transfer paper (not shown) placed on the manual feed tray 25 to the transport path 39A upstream of the registration roller pair 37. ing.

  Below the secondary transfer unit 35 and the fixing unit 36, a switchback conveyance path 39C and a reverse conveyance path 39D each including a plurality of conveyance rollers and conveyance guides are disposed.

  When forming an image on both sides of the transfer paper P, the switchback transport path 39C moves backward after moving the transfer paper P on which one side of the image has been fixed from one end (moves in the opposite direction to the time of entry). ) To carry out switchback.

  The reverse conveyance path 39D reverses the front and back of the transfer paper P that is switched back by the switchback conveyance path 39C, and feeds the paper again to the registration roller pair 37.

  The transfer paper P that has been subjected to the image fixing process on one side by the switchback conveyance path 39C and the reverse conveyance path 39D is reversed in its forward and reverse directions, and again enters the secondary transfer nip. . The transfer paper P is discharged onto the paper discharge tray 38 after the secondary transfer processing and fixing processing of the image are performed on the other surface.

  The image reading unit 4 includes a first carriage 41 having a light source (not shown) and a mirror member (not shown), a second carriage 42 having a mirror member (not shown), an imaging lens 43, an imaging unit 44, and a first contact. Glass 45 is provided. These are arranged on the apparatus main body 1M side and constitute a first surface reading section 40 that reads an image on one image surface (for example, the front image surface) of the original sheet S conveyed on the first contact glass 45. Yes. The first surface referred to here is one surface of the automatically conveyed document sheet S, for example, the front image surface.

  The image reading unit 4 is provided with a second contact glass 46 on which the document sheet S is placed, an abutting member 47a that can abut and position one side of the document sheet S, and the like.

  The first carriage 41 is provided below the first contact glass 45 and the second contact glass 46 so as to be movable in the left-right direction and to be position-controllable, and reflects the illumination light from the light source by the mirror member. Thus, the exposure surface side can be irradiated. The reflected light reflected by the document sheet S is imaged by the imaging lens 43 via the mirror members mounted on the first carriage 41 and the second carriage 42, and the image formed by the imaging unit 44 is formed. It can be read.

  The image reading unit 4 exposes and scans the image surface of the original sheet S placed on the second contact glass 46 while moving the first carriage 41 and the second carriage 42 at a speed ratio of 2: 1, for example, while the light source is on. Can be done. The image reading unit 4 can perform a fixed document reading function (so-called flatbed scanner function) by reading a document image with the imaging unit 44 during the exposure scanning.

  The image reading unit 4 can stop the first carriage 41 at a fixed position directly below the first contact glass 45. The image reading unit 4 has a moving document reading function (so-called DF scanner function) that reads an image on the first surface of the document sheet S during automatic document conveyance without moving an optical system including a light source and a reflection mirror. It can be demonstrated.

  Further, the image forming apparatus 1 has a second surface reading unit 48 built in the automatic document feeder 5 side in addition to the first surface reading unit 40 in the image reading unit 4. The second surface reading unit 48 scans the second surface of the original sheet S after passing over the first contact glass 45, for example, the image surface on the back side.

  The automatic document feeder 5 is configured as a sheet-through type automatic document feeder. The automatic document transport unit 5 includes a document table 51 that is a document placement table, a document transport unit 52 including various rollers and guide members, and a document discharge tray 53 that stacks document sheets S after image reading. Yes.

  As shown in FIG. 2, the image reading unit 4 is located above the apparatus main body 1 </ b> M of the image forming apparatus 1. The image reading unit 4 is capable of abutting and positioning one side of the original sheet S, a first contact glass 45 positioned on the conveyance path of the original sheet S, a second contact glass 46 on which the original sheet S can be placed. And an abutting member 47a. Further, the apparatus main body 1M is provided with an operation unit 150 on the upper front side.

  The operation unit 150 includes a print key 151 and a touch panel 152. When the print key 151 is pressed, the operation unit 150 requests the image forming apparatus 1 to start a copying operation.

  The automatic document feeder 5 is connected to the upper part of the apparatus main body 1M of the image forming apparatus 1 through a hinge h so as to be openable and closable, and a pressure plate sheet 47b is mounted on the lower surface. The automatic document feeder 5 rotates between the open position where the first contact glass 45 and the second contact glass 46 are exposed in the image reading unit 4 and the closed position where the first contact glass 45 and the second contact glass 46 are covered. It is designed to be operated dynamically.

  As shown in FIG. 3, hinge insertion holes 313 are provided on the upper surface of the image reading unit 4 on the left and right sides near the upper edge in the longitudinal direction. Each of the insertion-type hinges h is inserted into the hinge insertion hole 313. Pin push holes 312 are respectively provided on the left and right sides of the hinge insertion hole 313. A push pin 301 described later is pushed into the pin push hole 312.

  FIG. 4 is a diagram illustrating a state before the ADF 5 is opened and the push pin 301 is pushed by the ADF 5. The image reading unit 4 includes a push pin 301, a pin push hole 312, a rotary damper 302, a document size detection sensor 305, and an open / close detection sensor 306.

  The pin push-in hole 312 is provided on the upper surface of the image reading unit 4 so that the push-in pin 301 can be moved up and down. In the present embodiment, one pin pressing hole 312 is provided between the two hinges h, but the position and number of the pin pressing holes 312 are not limited to this. For example, when the weight of the ADF 5 is heavy, a plurality of pin push holes 312 may be provided, and the push pins 301 may be inserted into the pin push holes 312 respectively.

  The push pin 301 includes a stopper 308, a rack 304, a filler 307, and a tension spring 309 (see FIG. 8). The push-in pin 301 comes into contact with the ADF 5 and swings up and down in accordance with the opening / closing operation of the ADF 5. The push pin 301 and the rack 304 constitute a swing member according to the present invention.

  The stopper 308 is provided at a predetermined position of the push pin 301 with a diameter larger than that of the pin push hole 312. The stopper 308 prevents the push pin 301 from moving above a predetermined position by the stopper 308 coming into contact with the upper part of the image reading unit 4 when the push pin 301 moves upward.

  The rack 304 is provided on a predetermined side of the push pin 301 and meshes with a pinion 303 provided on the rotary damper 302 when the push pin 301 is lowered to a certain height. The rotary damper 302 and the pinion 303 constitute an impact relaxation member according to the present invention.

  The filler 307 is provided on a predetermined side of the push pin 301. When the push pin 301 is lowered to a certain height, the filler 307 crosses a document size detection sensor 305 and an open / close detection sensor 306, which will be described later, so that the open / close angle of the ADF 5 is detected. It has become.

  The rotary damper 302 includes a pinion 303 and is provided in the vicinity of the push pin 301 at a predetermined position within a range in which the push pin 301 in the image reading unit 4 moves up and down. The pinion 303 meshes with a rack 304 provided on the push pin 301 when the push pin 301 is lowered to a certain height.

  The document size detection sensor 305 is provided in the vicinity of the push pin 301 at a predetermined position within the range in which the push pin 301 inside the image reading unit 4 moves up and down. The document size detection sensor 305 detects the filler 307 when the filler 307 provided on the push pin 301 in the image reading unit 4 is lowered to a certain height. Upon detection of the filler 307 by the document size detection sensor 305, the image reading device 6 starts document size detection.

  The open / close detection sensor 306 is provided at a predetermined position within the range in which the push pin 301 in the image reading unit 4 moves up and down, and is provided near the push pin 301 below the document size detection sensor 305. The open / close detection sensor 306 detects the filler 307 when the filler 307 provided on the push pin 301 inside the image reading unit 4 is lowered to a certain height. When the opening / closing detection sensor 306 detects the filler 307, the image reading apparatus 6 determines that the ADF 5 is closed.

  The movement of the push pin 301 when the ADF 5 is closed will be described with reference to FIGS. As shown in FIG. 5, when the ADF 5 is closed, the base surface of the ADF 5 comes into contact with the pushing pin and moves downward. When the ADF 5 is further closed, the filler 307 of the push pin 301 crosses the document size detection sensor 305 with respect to the document size detection sensor 305 for starting the document size detection. Using this as a trigger, the document reading device 6 performs document size detection.

  The document size detection sensor 305 is provided above the open / close detection sensor 306 for detecting that the ADF 5 is closed for the following reason.

  If the pressure plate sheet 47b of the ADF 5 is not separated from the second contact glass 46 by a predetermined distance (if the ADF opening / closing angle is not large), an erroneous detection of the document size is caused. When the ADF 5 is completely closed, the surface of the ADF 5 holding the document reflects the LED light well even in an area where the document does not exist, and it is erroneously determined that the document exists in that area. It is because it will do. Therefore, when the ADF 5 is closed, first, it is necessary that the filler 307 crosses the document size detection sensor 305 and the ADF 5 is closed after the document size detection is started (the filler 307 crosses the open / close detection sensor 306). Because.

  When the ADF 5 is further closed and the ADF 5 exceeds the free stop range of the hinge h, the ADF 5 is switched so as to drop by its own weight. In this embodiment, the free stop range of the hinge h is 20 to 60 degrees, but the free stop range is not necessarily limited to this range.

  When the angle at which the ADF 5 falls by its own weight is reached, the rack 304 provided in the push pin 301 meshes with the pinion 303 provided in the rotary damper 302, whereby the pinion 303 rotates in the direction of the arrow in FIG. The collision mitigation power starts to work against the force that travels to Thereby, the fall speed of the ADF 5 is reduced, so that the impact sound when the ADF 5 is closed can be reduced, and the noise reduction can be realized.

  Thereafter, as shown in FIG. 7, when the filler 307 included in the push-in pin 301 moves to a position that covers the open / close detection sensor 306, the image reading device 6 determines that the ADF 5 is closed.

  The manner in which the push pin 301 moves upward together with the ADF 5 will be described with reference to FIGS. 8 and 9.

  FIG. 8 is a cross-sectional view as seen from the front side of the image forming apparatus 1 and shows a state in which the ADF 5 is closed. The tension spring 309 having elasticity is connected at one end to a pin-side hook 310 provided on the push-in pin 301 and connected at the other end to a device-side hook 311 provided on the image reading device 6 side. Has been. The pushing pin 301 is given a force returning in the direction of the arrow in the drawing by the elastic force of the tension spring 309. In this embodiment, the tension spring 309 is used as a member for applying a force to the push pin 301. However, a member having another elastic force may be used.

  FIG. 9 shows a state where the ADF 5 is opened from the state shown in FIG. When the ADF 5 is opened, the pushing pin 301 moves upward because the tension spring 309 applies a force returning to the pushing pin 301 in the drawing as described above. Then, the push pin 301 returns to a predetermined position where the stopper 308 contacts the upper surface of the image reading device 6.

  10 and 11 are cross-sectional views as viewed from one side of the image forming apparatus 1. FIG. 10 shows a state immediately after the ADF 5 starts to open from a closed state, and FIG. 11 shows a state in which the ADF 5 is fully opened. Is shown.

  When the ADF 5 is opened, the push pin 301 rises and a force is applied to the pinion 303 of the rotary damper 302 through the rack 304. The pinion 303 starts to rotate in the direction of the arrow in the figure, but if the same impact relaxation force as that when the ADF 5 is closed is applied, the push-in pin 301 is prevented from rising.

  In the present embodiment, by using the one-way rotary damper 302, no impact relaxation force is applied to the rotation in the direction of the arrow in the figure. That is, since the force that reduces the impact works only when the ADF 5 moves in the closing direction, the push-in pin can be raised smoothly.

  The opening / closing detection sensor 306 is turned off when the filler 307 rises as the push pin 301 rises. The shift of the detection of the open / close detection sensor 306 to the OFF state is also used as a trigger for energy saving return.

  In the present embodiment, the push pin 301, the pin push hole 312, the rotary damper 302, the document size detection sensor 305, and the open / close detection sensor 306 are provided on the image reading unit 4 side. As shown in FIG. May be provided.

  As described above, in the image reading device 6 according to the present embodiment, the image reading unit 4 swings in accordance with the opening / closing operation of the ADF 5 having the hinge h, and the push pin 301 for detecting the opening / closing angle of the ADF 5 The rotary damper 302 has a pinion 303 that reduces the impact between the ADF 5 and the image reading unit 4 when the ADF 5 is closed by engaging with the rack 304 of the push pin 301.

  With this configuration, when the ADF 5 is closed, the push pin 301 is lowered, and the rack 304 meshes with the pinion 303 of the rotary damper 302, so that the impact between the ADF 5 and the image reading unit 4 can be reduced. Impact noise can be reduced. Further, since it is not necessary to provide a damper inside the hinge, it is not necessary to increase the size of the apparatus.

  Further, the rotary damper 302 may have a force that alleviates the impact only when the ADF 5 moves in the closing direction, and may start a force that alleviates the impact from the position where the ADF 5 falls by its own weight. With this configuration, when the ADF 5 is opened, the force by the rotary damper 302 does not act, so that the push pin 301 can smoothly return to a predetermined position. In addition, in the range where the ADF 5 does not fall by its own weight, that is, in the so-called free stop range, the shock relaxation force does not work during the opening / closing operation of the ADF.

  Further, the push pin 301 and the rotary damper 302 may be provided on the ADF 5 side.

  Although the embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the present invention.

  According to the present invention, it is possible to reduce the impact sound generated when the ADF is closed without increasing the size of the apparatus, which is useful for image reading apparatuses and image forming apparatuses in general.

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 4 Image reading part 5 Automatic document conveying part (automatic document conveying apparatus)
6 Image Reading Device 301 Push Pin (Oscillating Member)
302 Rotary damper (impact mitigating member)
303 Pinion (impact mitigating member)
304 Rack (swinging member)

JP 2012-104880 A

Claims (3)

In an image reading apparatus comprising an automatic document feeder having a hinge having an opening / closing mechanism and an image reading unit for reading an image,
The image reading unit swings in accordance with an opening / closing operation of the automatic document conveying unit, and a swinging member for detecting an opening / closing angle of the automatic document conveying unit,
Have a, a shock absorbing member for relaxing an impact and the aforementioned automatic document feeder is closed when the automatic document feeder the image reading unit by meshing with the oscillating member,
Rukoto the impact damper, the force to alleviate the impact is exerted only when moving in the automatic document feeder is closed direction, starting from a position where the automatic document feeder is free-fall, force acts to mitigate the impact An image reading apparatus. The image reading apparatus according to claim 1, wherein the swinging member and the impact reducing member are provided on a side of the automatic document conveyance unit. An image forming apparatus comprising the image reading apparatus according to any one of claims 1-2.

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