JP5696494B2 - Pull-in device and image forming apparatus provided with the same - Google Patents

Description

  The present invention relates to a pull-in device and an image forming apparatus, and more particularly to a pull-in device provided with a pull-in means for pulling a paper feed tray into the apparatus main body and an image forming apparatus provided with the pull-in device.

  In general, an image forming apparatus includes a reading unit that reads an image of a document placed on a contact glass, an image forming unit that forms an image read by the reading unit on recording paper, and supplies the recording paper to the image forming unit. An electrostatic latent image is formed by irradiating the surface of the photosensitive member with light by an optical writing device included in the image forming unit, and cyan on the electrostatic latent image formed on the surface of the photosensitive member. In addition, toner composed of magenta, yellow, and black color components is supplied to form a visible image as a toner image, and a color image is formed by transferring the toner image of each color component onto a transfer material.

  Further, the above-described image forming apparatus has a paper feed tray for storing recording paper. This paper feed tray is configured to be detachable in the pull-out direction with respect to the paper feed unit via a pair of left and right rail members provided inside the paper feed unit, so that recording paper can be appropriately supplied. It has become.

  Such a drawer-type paper feed tray is heavy when the recording paper is replenished, and therefore places a heavy burden on the user when the paper feed tray is attached or detached. In addition, since the paper feed tray is heavy, if the user applies an excessive operating force, the paper feed tray may be installed in the paper feed unit vigorously. In such a case, the position of the recording paper stored in the paper feed tray may be shifted or the paper feed tray may be damaged due to an impact when the paper feed tray is mounted. For this reason, it is necessary to consider the operation force required to attach and detach the paper feed tray.

  In recent years, the concept of barrier-free and universal design has become widespread because of considerations for the elderly and people with disabilities. In December 2000, the US federal government established “Accessibility Standards” in Article 508 of the Rehabilitation Act. "announced. This states that “the force to actuate the device and key should not exceed 5 pounds (22.2 N)”. This is intended to be employed by these people in the office environment in the future, and it is necessary to give consideration to the operability of the equipment. Therefore, it is desired to reduce the operating force for the paper feed tray. Note that since the user's operation force varies, when the recording paper is stacked with an excessive operation force, the recording paper stacked and accommodated by the impact of the abutment at the mounting position, its positioning fence, and the like are displaced.

  Conventionally, in order to prevent such a problem, an image forming apparatus including a drawing device that pulls a paper feed tray into a mounting position is known (for example, see Patent Document 1).

  In the image forming apparatus described in Patent Document 1, when the paper feed tray is pushed to a certain extent in the mounting direction, the engaged portion provided on the paper feed tray engages with the engaging portion provided on the drawing device. . When the engaged portion engages with the engaging portion, the pull-in device pulls the paper feed tray to the mounting position. As described above, since the sheet feeding tray can be automatically pulled into the mounting position by the pulling device with a predetermined pulling force, the burden on the user can be reduced. In addition, a speed-dependent damper unit is provided in which the load increases or decreases according to the magnitude of the moving speed (drawing speed) when the paper feed tray is drawn. For this reason, when the paper feed tray is mounted with an excessive operating force, the load increases due to the action of the speed-dependent damper unit, and the pull-in speed is reduced. As a result, it is possible to suppress the occurrence of an impact when the paper feed tray is mounted, and it is possible to suppress the misalignment of the recording paper accommodated in the stack and the damage of the paper feed tray.

  However, in the conventional image forming apparatus described in Patent Document 1 described above, the speed-dependent damper unit operates until the paper feed tray is pulled into the mounting position. The pulling force will also decrease. If the pull-in force of the paper feed tray is reduced in this way, the paper feed tray may stop before reaching the mounting position. Therefore, the conventional image forming apparatus has a problem that the feeding tray cannot be reliably pulled into the regular mounting position while the pulling-in speed of the feeding tray is reduced.

  The present invention has been made to solve the above-described conventional problems, and reduces the pull-in force of the paper feed tray while reducing the pull-in speed of the paper feed tray to prevent the paper feed tray from being lowered. It is an object of the present invention to provide a pull-in device and an image forming apparatus that can be reliably pulled into a mounting position.

In order to achieve the above object, the pulling device according to the present invention pulls a paper feed tray that is detachably attached to the apparatus main body to a set position, and engages the pulling device with the paper feeding tray. A pull-in device having a decelerating unit that decelerates a pull-in speed when pulling in the tray, wherein the pull-in unit generates a pull-in force that pulls the paper-feed tray into a set position; and the paper-feed tray A rotation member that rotates in response to the pulling of the gear, and a gear portion that is provided on the rotation member and rotates about a rotation fulcrum of the rotation member, wherein the speed reduction means generates a speed reduction force. A reduction force generating member to be engaged, and an engagement gear coupled to the reduction force generation member and engaged with the gear portion. To release the engagement between the engaging gear just before reaching the position, it has a notch which is cut out radially inwardly.

With this configuration, when the paper feed tray is retracted, the present invention releases the engagement between the retracting means and the speed reducing means immediately before the paper feed tray reaches the set position. The load is released. Specifically, the notch portion faces the engagement gear immediately before the paper feed tray reaches the set position, and a gap is formed between the gear portion and the engagement gear. Thus, the engagement between the gear portion and the engagement gear can be reliably released immediately before the paper feed tray reaches the set position. For this reason, it is possible to reduce the pull-in force of the paper feed tray while reducing the pull-in speed of the paper feed tray and reliably pull the paper feed tray into the proper mounting position.

  In the pull-in device according to the present invention, the speed reduction means may be configured to release the connection between the speed reduction force generating member and the engagement gear when the paper feed tray is pulled out.

  With this configuration, according to the present invention, when the paper feed tray is pulled out, the speed reducing unit releases the connection between the deceleration force generating member and the engagement gear, so that it is possible to eliminate a load when the paper feed tray is pulled out. As a result, the paper feed tray can be pulled out without requiring an excessive operating force.

An image forming apparatus according to the present invention includes the pull-in device according to any one of claims 1 and 2 .

  With this configuration, the present invention includes a pull-in device that can reduce the pull-in force of the paper feed tray and reduce the pull-in force of the paper feed tray and reliably pull the paper feed tray into the proper mounting position while reducing the pull-in speed of the paper feed tray. An image forming apparatus can be provided.

  The present invention provides a pull-in device and an image forming apparatus that can reduce the pull-in force of the paper feed tray while reducing the pull-in speed of the paper feed tray and can reliably pull the paper feed tray into the proper mounting position. can do.

1 is a schematic configuration diagram of a digital multifunction peripheral according to an embodiment of the present invention. 1 is a perspective view of a digital multifunction peripheral according to an embodiment of the present invention. It is a block diagram which shows the control structure of the digital multifunctional device which concerns on embodiment of this invention. FIG. 3 is a diagram illustrating a detailed configuration of a sheet feeding unit. (A), (b) is a figure explaining operation | movement of a raising / lowering apparatus. It is a perspective view which shows schematic structure of a raising / lowering apparatus. It is a perspective view which shows the external appearance of a drawing-in apparatus. It is a figure which shows schematic structure of a drawing-in apparatus, Comprising: It is the perspective view which looked at the drawing-in apparatus from the bottom face side. It is the perspective view which looked at the drawing-in apparatus of the state which removed some components from the bottom face side. It is a bottom view which shows the internal structure of a drawing-in apparatus. It is a perspective view which shows the nail | claw of a drawing-in apparatus. It is an expansion perspective view which shows the 2nd gear of a drawing-in apparatus. (A), (b) is the schematic which shows the connection state of a 2nd gear and a 3rd gear. FIG. 6 is a schematic diagram illustrating a setting position of a paper feed tray. It is the schematic which shows the engagement state of the 1st gear and the 2nd gear just before a paper feed tray reaches a set position. FIG. 6 is a schematic diagram illustrating a state immediately before a sheet feeding tray reaches a set position. It is a figure which shows operation | movement of a drawing-in apparatus, Comprising: It is a figure which shows the initial state of drawing in of a paper feed tray. It is a figure which shows operation | movement of a drawing-in apparatus, Comprising: It is a figure which shows the state with which the urging | biasing force of the 1st spring and the urging | biasing force of the 2nd spring were balanced. It is a figure which shows operation | movement of a drawing-in apparatus, Comprising: It is a figure which shows the state which drawing-in of the paper feed tray was completed. (A), (b) is a figure explaining the drawing-in operation force and drawing-out operation force of a paper feed tray. It is the comparison figure which compared the drawing-in speed of the drawing-in apparatuses from which each structure differs.

  Embodiments of the present invention will be described below with reference to the drawings.

  1 to 3 are diagrams showing an embodiment of an image forming apparatus provided with a pull-in device according to the present invention, and show an example in which the image forming apparatus is applied to a digital multifunction peripheral.

  As shown in FIGS. 1 and 2, the digital multifunction peripheral 1 includes an image forming unit A, a paper feeding unit B, a fixing unit C, a document reading unit (scanner) D, and an operation display unit E. ing.

  The image forming unit A includes the photosensitive drum 2 and image forming elements provided along the outer periphery thereof. The image forming elements are a charging unit 3, a developing unit 4, a transfer unit 5, and a cleaning blade 6 provided on the outer periphery of the photosensitive drum 2 in the counterclockwise direction (same as the rotation direction of the photosensitive drum). And a static elimination lamp 27. Optical writing with a laser beam L is performed between the charging unit 3 and the developing unit 4 on the exposure surface of the photosensitive drum 2. The laser beam L is emitted to the surface of the photosensitive drum 2 from the optical scanning device 7 having a scanning optical system such as a polygon mirror and an imaging lens (not shown). The surface is scanned in a substantially axial direction (main scanning direction).

  The charging unit 3 charges the surface of the photosensitive drum 2 to a predetermined potential. When optical writing is performed on the charged photosensitive drum 2 by the laser beam L, a latent image is formed on the surface of the photosensitive drum 2. Is formed. The latent image is developed with toner by the developing unit 4, transferred to a sheet (here, paper) conveyed from a sheet feeding unit B described later by a transfer unit 5 using a transfer belt, and sent to the fixing unit C side. The toner remaining on the surface of the photosensitive drum 2 is scraped off by the cleaning blade 6, and the surface of the photosensitive drum 2 is neutralized by the neutralizing lamp 27, and then rotates toward the charging unit 3 again. That is, charging, optical writing, development, transfer, cleaning, and static elimination processes are performed during one rotation of the photosensitive drum 2, and this operation is repeated for each image (each image formation on a sheet).

  The paper feed unit B includes four stages of paper feed trays 8, 9, 10, 11 and paper feed units 12, 13, 14, 15 provided at the upper exit side of each paper feed tray 8-11 in the paper transport direction. A longitudinal conveyance path 20 including a pair of conveyance rollers 16, 17, 18, and 19 that guides the sheet pulled out from each of these sheet feeding units 12 to 15 to the image forming unit A side, and a sheet conveyance direction of the vertical conveyance path 20 It is composed of a registration roller pair 21 provided on the most downstream side. In the present embodiment, the upper two stages of the four-stage paper feed trays 8, 9, 10 and 11 are on the main body side of the digital multi-function peripheral 1, and the lower two stages are on the main body of the digital multi-function peripheral as shown in FIG. It is attached to the lower part. The paper feed trays 8, 9, 10, and 11 are detachably attached to the digital multi-function peripheral body.

  Further, the side plates 20a and 20b forming the vertical conveyance path 20 are configured to be openable around a lower hinge as shown in FIG. Thereby, when a jam occurs on the exit side of the vertical conveyance path 20 or the paper feed units 12 to 15, the side plates 20a and 20b can be opened to perform the jam processing. As shown in FIG. 2, a duplex unit F is provided on the side of the main body of the digital multifunction peripheral 1 on the side plates 20a and 20b as required.

  Further, a registration sensor 21 a is provided on the upstream side of the registration roller pair 21 in the sheet conveying direction so that the presence or absence of the sheet reaching the registration roller pair 21 can be detected.

  The fixing unit C includes a fixing unit 23 including a heating roller 23a and a pressure roller 23b provided immediately downstream of the transfer unit 5 in the sheet conveying direction. Further, on the downstream side in the sheet conveyance direction of the fixing unit 23, a sheet discharge path 25a for discharging a sheet to a sheet discharge tray 26 via a sheet discharge roller 25 by a branch claw 24 and a duplex unit (not shown) (optionally attached) A double-sided conveying path 24a for carrying out the sheet is provided.

  As shown in FIG. 2, the scanner unit D is disposed above the paper discharge tray 26 and is provided with a contact glass 28 for placing a document on the upper end. Although not shown in the present embodiment, a unit such as an automatic document feeder (hereinafter referred to as ADF) G (see FIG. 3) is mounted on the upper portion of the scanner unit D to optically read (scan) the document. ) Is performed.

  As shown in FIG. 2, the operation display unit E is arranged on the front side of the main body (operation side OP) of the digital multi-function peripheral 1. The operation display unit E has various operation buttons 29 a such as a print key and a menu. A display unit 29b for displaying various information such as a display is disposed. The display unit 29b may be configured with a touch panel.

  Next, a control configuration of the digital multifunction peripheral 1 according to the present embodiment will be described with reference to FIG.

  As shown in FIG. 3, the digital multifunction peripheral 1 (see FIG. 1) executes each control of the ADF (G), the optical scanning device 7, the image forming unit A, the fixing unit C, the paper feeding unit B, and the scanner unit D. The system control unit 30 includes an operation display unit E, an image memory 31, an image processing unit 32, a non-volatile memory 33, and various sensors in addition to the control target. Yes. The system control unit 30 executes a control desired by the user in response to an instruction input from the operation display unit E, temporarily stores the image data read by the scanner unit D in the image memory 31, and then the predetermined or desired by the user The image processing is performed by the image processing unit 32 and output to the optical scanning device 7, the image is formed by the image forming unit A, transferred to the sheet P fed from the paper feed unit B, and the paper discharge roller 25 is transferred by the fixing unit C. The paper is discharged from the printer or carried out to the duplex unit F side. These control programs are stored in the non-volatile memory 33, and the system control unit 30 executes predetermined control according to the control program.

  The control program is stored in the nonvolatile memory 33 in advance and used, for example, on a hard disk drive (not shown) from a server via a network (not shown) or loaded on a medium drive device (not shown). Program data recorded on a recording medium such as a ROM or SD card can be downloaded and used, or upgraded.

  In this embodiment, a digital multi-function peripheral has been described as an example of the image forming apparatus. However, the present invention can be applied to all devices that form images on sheet-like members such as digital copiers, analog copiers, printers, and facsimiles. .

  Next, with reference to FIGS. 4 and 5, the detailed configuration of the sheet feeding unit B will be described by taking the sheet feeding tray 8 as an example. In FIGS. 4 and 5, a frame for regulating the outer edge of the sheet is omitted.

  As shown in FIG. 4, on the back side (left side in FIG. 4) when viewed from the operation side OP of the paper feeding unit B, an elevating device 50 for raising the bottom plate 81 of the paper feeding tray 8, and the paper feeding tray A retraction device 70 having eight retraction functions is provided. Further, a pin 100 protruding downward is provided on the bottom surface of the box-shaped paper feed tray 8. The pin 100 is slidably engaged with the guide groove 701 of the retracting device 70.

  Further, the paper feed tray 8 includes a bottom plate 81 supported so as to be swingable around a fulcrum 83 (see FIG. 5A), a lifting member 84 (FIG. 5) comprising a drive shaft 85 and an eccentric rotating piece 86. (See (a)).

  As shown in FIG. 5A, the elevating member 84 contacts the position where the tip end portion (free end side) of the eccentric rotating piece 86 is separated from the fulcrum 83 on the lower surface of the bottom plate 81, and the fulcrum 83 is the center. The bottom plate 81 can be moved up and down. Further, a paper surface detection sensor 89 is provided on the main body side of the digital multi-function peripheral 1 or the main body side of the paper feed unit B above the setting position of the paper feed tray 8, and the rotation angle of the filler 89 a extending from the paper surface detection sensor 89 is illustrated. It is detected by an optical sensor that does not detect whether the upper surface of the sheet bundle has reached the paper feeding position.

  As shown in FIG. 6, the lifting device 50 includes the lifting member 84 and the lifting drive device 51 described above. The elevating member 84 provided below the bottom plate 81 includes a drive shaft 85, an eccentric rotating piece 86 fixed near one end of the drive shaft 85, and a radial direction of the drive shaft 85 near the other end of the drive shaft 85. And two engaging projections 87 attached in a protruding manner. When the drive shaft 85 is rotated around its central axis, the eccentric rotary piece 86 also rotates around the central axis of the drive shaft 85, and the eccentric rotary piece 86 is in contact with the lower surface of the bottom plate 81 and on the free end side of the bottom plate 81. Is lifted upward as shown in FIGS. 5 (a) and 5 (b). Accordingly, the upper surface of the sheet bundle stacked on the bottom plate 81 comes into contact with the paper feed roller 12a. That is, the sheet stored in the sheet feeding tray 8 can be fed.

  The lifting drive 51 includes a lifting motor 52, a worm gear 53 attached to the output shaft of the lifting motor 52, a worm wheel 54 that meshes with the worm gear 53, a spur gear 55 that meshes with the worm wheel 54, The coupling 56 is attached to the rotation shaft of the gear 55. The coupling 56 has a cylindrical shape and has four cuts extending from the free end in parallel to the rotation axis. The coupling 56 is provided with an engagement provided on the drive shaft 85 of the elevating member 84. The protrusion 87 is fitted, and the drive shaft 85 of the lift member 84 is rotationally driven by the lift motor 52.

  In the sheet feeding unit B configured as described above, when the sheet feeding tray 8 is pulled out, a sheet bundle is stacked on the bottom plate 81 and the sheet feeding tray 8 is pushed into the sheet feeding unit B, the sheet feeding tray 8 is not illustrated. Move on the rail to the back side of the paper feeding unit B. At this time, when the paper feed tray 8 moves to the back side of the paper feed unit B by a predetermined distance, the paper feed cassette 8 is drawn into the set position by the drawing device 70. The configuration and operation of the pull-in device 70 will be described later.

  When the paper feed cassette 8 is mounted at the set position, it is detected by the set detection sensor 44, and the raising operation of the bottom plate 81 is started. Here, since the coupling 56 does not mesh with the engaging protrusion 87 at first, the coupling 56 is pushed to the back side against the elastic biasing force of the spring 57 and rotates in a form biased to the engaging protrusion 87. Therefore, the paper feed tray 8 at this time receives a force that is pushed out by the coupling 56 (see FIG. 4).

  Thereafter, when the engagement protrusion 87 is engaged with the groove of the coupling 56 by the rotation of the coupling 56, the groove of the coupling 56 enters the engagement protrusion 87 by the elastic force of the spring 57, and the driving force of the lifting motor 52 is driven by the driving shaft. 85. Then, as shown in FIG. 5A, when the paper surface detection sensor 89 detects that the paper surface of the stacked uppermost paper has reached a predetermined paper feed position, the driving of the lifting motor 52 is stopped.

  Next, the configuration of the retracting device 70 will be described with reference to FIGS.

  In the present embodiment, the drawing device 70 that pulls in the paper feed tray 8 will be described as an example, but a drawing device having the same configuration as the drawing device 70 can be applied to the other paper feeding trays 9, 10, and 11.

  As shown in FIG. 7, the retracting device 70 includes a housing 702 composed of an upper cover member 702a and a lower cover member 702b, and various components are accommodated inside the housing. A guide groove 701 is formed on the upper surface of the upper cover member 702a so that the pin 100 attached to the bottom surface of the paper feed tray 8 (see FIG. 4) is slidably engaged. The pin 100 is slidable along the guide groove 701 in the direction of the arrow K (insertion direction) and the direction of the arrow L (drawing direction) in FIG. 7 according to the insertion and withdrawal of the paper feed tray 8. At the end of the guide groove 701 in the pull-out direction, a tapered guide groove inlet 701a inclined in the pull-out direction so as to receive the pin 100 is formed. The lower cover member 702b is attached on a base member 1a (see FIG. 15) provided inside the main body of the digital multi-function peripheral 1 (see FIG. 1).

  Next, the internal structure of the retracting device 70 will be described with reference to FIGS. 8-10 is the figure which looked at the drawing-in apparatus 70 of the state which removed the lower cover member 702b from the bottom face side. Further, FIG. 9 is a view showing a state in which a part of the retracting device 70 in FIG. 8 is removed.

  As shown in FIGS. 8 and 9, the pull-in device 70 is a pull-in unit 71 that pulls in the paper feed tray 8 to the set position, and a pull-in unit 71 that pulls in the paper feed tray 8 by engaging with the pull-in unit 71. And a damper unit 72 as a decelerating means for decelerating the pull-in speed.

  The pull-in unit 71 is provided on the first lever 710 and the first lever 710 as a rotation member that rotates around the rotation fulcrum 710 a as the paper cassette 8 is retracted, and is synchronized with the first lever 710. A fan-shaped first gear 711 that rotates about the rotation fulcrum 710a, a second lever 712 that rotates about the rotation fulcrum 712a, and a pulling force for pulling the paper feed tray 8 to the set position. It has the 1st spring 713 and the 2nd spring 714 as a drawing force generation member to generate | occur | produce. The first gear 711 in the present embodiment constitutes a gear portion according to the present invention.

  As shown in FIG. 10, the first lever 710 has a claw 715 configured to be rotatable about a rotation fulcrum 710 b provided at an end portion separated from the rotation fulcrum 710 a. The claw 715 can freely rotate with respect to the first lever 710 around the rotation fulcrum 710b. As shown in FIG. 11, the claw 715 is engaged with an engagement groove 715a that engages with the pin 100 during a normal retraction operation and an engagement portion 723a of a damper holder 723 described later, thereby moving the claw 715. By restricting, a locking portion 715b that restricts the rotation of the first lever 710 is integrally formed.

  Further, as shown in FIG. 10, the first lever 710 is biased by the first spring 713 by being engaged with the end 713 a of the first spring 713 in the engagement hole 710 c, and the end of the first spring 713 is engaged. 713b engages with an engagement hole 712b of the second lever 712 configured to be rotatable, and an end 714b of the second spring 714 engages with an engagement portion 712c of the end of the second lever 712, An end 714a of the second spring 714 is engaged with an engagement portion (not shown) of the lower cover member 702b (see FIG. 7).

  As shown in FIGS. 8 and 9, the damper unit 72 includes a second gear 720 as an engagement gear that meshes with the first gear 711, and a third gear that can rotate coaxially with the rotation center axis of the second gear 720. 721 and a speed-dependent damper 722 that meshes with the third gear 721. The third gear 721 and the speed-dependent damper 722 in the present embodiment constitute a deceleration force generating member according to the present invention.

  As shown in FIG. 12, a latch 720 a is provided at the center of the second gear 720. Further, as shown in FIGS. 13A and 13B, a latch 721 a is also provided at the center of the third gear 721. That is, the latch 720a of the second gear 720 and the latch 721a of the third gear 721 are engaged only when rotating in one direction. For example, as shown in FIG. 13 (a), when the second gear 720 rotates counterclockwise, the latch 720a of the second gear 720 and the latch 721a of the third gear 721 are engaged, and the second gear 720 and the third gear 720 are engaged. Only the rotation in one direction (counterclockwise) is transmitted to and from the gear 721 so that the second gear 720 and the third gear 721 rotate in synchronization. Therefore, the rotation direction of the second gear 720 is between the second gear 720 and the third gear 721 only when the second gear 720 rotates when the paper feed tray 8 is pulled into the set position. The rotation is transmitted through the latch 720a and the latch 721a.

  On the other hand, as shown in FIG. 13B, when the second gear 720 rotates clockwise, the engagement between the latch 720a of the second gear 720 and the latch 721a of the third gear 721 is released, and the second gear 720 is released. And the third gear 721 are prevented from transmitting rotation. Therefore, even when the second gear 720 rotates clockwise when the paper feed tray 8 is pulled out from the set position, rotation is transmitted between the second gear 720 and the third gear 721. Absent. That is, when the paper feed tray 8 is pulled out, the connection between the second gear 720 and the third gear 721 is released, and the rotation of the second gear 720 is not transmitted to the speed-dependent damper 722. Thereby, the load at the time of pulling out the paper feed tray 8 can be eliminated. As a result, the paper feed tray 8 can be pulled out without requiring an excessive operating force.

  As shown in FIG. 10, the speed-dependent damper 722 generates a large load (damping force) when the rotational speed is high, and generates a small load when the rotational speed is small. It is transmitted to the gear 721. When the paper feed tray 8 is pulled out from the set position, the transmission of rotation between the second gear 720 and the third gear 721 is interrupted by the latch 720a and the latch 721a (see FIG. 13). The load due to the dependency damper 722 is not transmitted from the third gear 721 to the second gear 720.

  Here, as shown in FIG. 14, the setting position of the paper feed tray 8 is that the paper feed tray 8 is inserted into the main body of the digital multi-function peripheral 1 and the front end of the paper feed tray 8 in the insertion direction (left side in the figure). The stopper 8a provided at the end) is in contact with the stay 1b erected on the base member 1a.

  Next, a characteristic configuration of the present invention will be described with reference to FIGS. 15 and 16.

  As shown in FIG. 15, the first gear 711 according to the present embodiment meshes with the second gear 720 so that the engagement with the second gear 720 is released immediately before the paper feed tray 8 reaches the set position. A notch portion 711a is formed in a partial region of the fan-shaped outer peripheral portion and is notched radially inward. When the notch 711 a faces the second gear 720, a predetermined gap is formed between the notch 711 a and the second gear 720. For this reason, rotation is not transmitted between the notch 711a and the second gear 720.

  Here, immediately before the paper feed tray 8 reaches the set position, as shown in FIG. 16, when the distance from the tip of the stopper 8a of the paper feed tray 8 to the stay 1b becomes a predetermined distance (for example, 5 mm). Say. Therefore, when the first gear 711 rotates with the insertion of the paper feed tray 8 and immediately before the paper feed tray 8 reaches the set position, the notch 711a shown in FIG. 15 faces the second gear 720. It has become. At this time, the engagement between the first gear 711 and the second gear 720 is released.

  Next, the operation of the retracting device 70 will be described with reference to FIGS. 10 and 17 to 19.

  First, as shown in FIG. 10, in the retracting device 70, when the pin 100 does not press the engaging groove 715 a (see FIG. 11), the engaging portion 715 b of the claw 715 is engaged with the engaging portion 723 a of the damper holder 723. It has been stopped.

  When the paper feed tray 8 is further inserted into the main body from the state shown in FIG. 10 toward the set position, the pin 100 is operated by the user of the paper feed tray 8 from the guide groove entrance 701a as shown in FIG. The engagement groove 715a of the claw 715 is pressed by being inserted into the guide groove 701 by force. As a result, the claw 715 that has been engaged with the damper holder 723 rotates clockwise about the rotation fulcrum 710b, and the engagement between the engagement portion 715b and the engagement portion 723a shown in FIG. 10 is released. When the locking is released, the claw 715 starts to retract the pin 100 by the biasing force of the first spring 713. Further, as the pin 100 is retracted, the first lever 710 rotates clockwise. Accordingly, the first gear 711 also rotates clockwise in synchronization with the rotation of the first lever 710. At this time, the outer peripheral portion of the first gear 711 and the second gear 720 are engaged with each other, and a damping force (load) by the speed-dependent damper 722 is applied via the third gear 721. The pull-in direction is the right direction in FIGS.

  Next, as shown in FIG. 18, when the claw 715 continues to retract the pin 100, the pin 100 is further retracted along the guide groove 701 and is retracted to a predetermined balance position. At this time, the rotational moment of the second lever 712 due to the biasing force of the first spring 713 and the rotational moment of the second lever 712 due to the biasing force of the second spring 714 are balanced.

  Then, as shown in FIG. 19, when the pin 100 is further pulled from the balanced position shown in FIG. 18, the biasing force of the second spring 714 is greater than the rotational moment of the second lever 712 due to the biasing force of the first spring 713. Since the rotational moment of the second lever 712 becomes larger, the second lever 712 rotates counterclockwise. At this time, when the paper feed tray 8 is pulled to the position immediately before the set position (see FIG. 16), the notch 711a moves to a position facing the second gear 720 as the first gear 711 rotates. As a result, the engagement between the first gear 711 and the second gear 720 is released. Therefore, when the paper feed tray 8 reaches just before the set position, the damping force (load) by the speed-dependent damper 722 does not act on the pull-in of the paper feed tray 8. Thereafter, the pin 100 moves to the drawing completion position (set position) of the paper feed tray 8 shown in FIG. 19 into the apparatus main body without receiving the damping force (load) by the speed dependent damper 722.

  On the other hand, when the paper feed tray 8 is pulled out from the set position, the pull-in device 70 moves the claw 715 in the pull-out direction via the pin 100 to move the second lever 712 clockwise via the first spring 713. Rotate in the direction. As a result, the retracting device 70 extends the second spring 714 and extends the first spring 713 by further pulling out the paper feed tray 8. Therefore, the pulling device 70 stores the urging force for pulling the paper feed tray 8 in the first spring 713 and the second spring 714 when the paper feed tray 8 is pulled out. When the paper feed tray 8 is pulled out, the transmission of rotation between the second gear 720 and the third gear 721 is blocked by the latch 720a and the latch 721a (see FIG. 13). For this reason, since the load due to the speed-dependent damper 722 is not transmitted from the third gear 721 to the second gear 720, the paper feed tray 8 can be easily pulled out with a relatively small operating force.

  Next, with reference to FIGS. 20A and 20B, each operation force when the paper feed tray 8 is attached and detached will be described.

In FIGS. 20A and 20B, P ₁ is the sum of the urging forces of the first spring 713 and the second spring 714 acting when the paper feed tray 8 is pulled into the set position. This is the pulling force of the paper tray 8. Further, _{P 2} in FIGS. 20 (a) is a load acting upon the fitting of the coupling 56 and the engagement projection 87. Further, in FIG. 20 (a), (b) , P 3 is a sliding load of the paper feed tray 8, direction acting between the time the drawer at the time of retraction of the paper feed tray 8 is different. In FIGS. 20A and 20B, P ₄ is a damping force (load) by the speed-dependent damper 722, and the direction in which the sheet tray 8 acts differs depending on whether it is retracted. Furthermore, P ₅ in FIG. 20 (b) is a load required for releasing the engagement between the coupling 56 and the engagement projection 87.

As shown in FIG. 20A, the pulling operation force F _in (N) required when the paper feed tray 8 is pulled to the set position is derived from the pulling force P ₁ by the pulling device 70 and the load P ₂ and the sliding load. This is a value obtained by subtracting the sum of P ₃ and damping force P ₄ . That is, the pulling operation force F _in is expressed as F _in = P ₁ − (P ₂ + P ₃ + P ₄ ).

For example, the pulling force P ₁ (N) = 12N ± 2N by the pulling device 70, the load P ₂ (N) = 3N ± 1N, the sliding load P ₃ (N) = 3N ± 1N, and the damping force P ₄ (N) = When 2N ± 1N, the pulling operation force F _in (N) is F _in (N) = 10N− (4N + 4N + 3N) = − 1N. As described above, assuming that the retracting force P ₁ by the retracting device 70 is the smallest within the specification and each load P _{2 to} P ₄ is the largest within the specification, the retracting operation force F _in (N) becomes −1N. The paper feed tray 8 cannot be reliably pulled to the set position.

Therefore, in the present embodiment, as described above, since the first gear 711 is engaged with the second gear 720 is released immediately before the set position, the damping force by the speed-dependent damper 722 (load) P ₄ is Canceled. For this reason, the pulling operation force F _in (N) _in the present embodiment is F _in (N) = 10N− (4N + 4N) = 2N. Therefore, in the present embodiment, even in the above case, it is possible to ensure a sufficient pulling operation force F _in (= 2N) for pulling the paper feed tray 8 to the set position.

On the other hand, as shown in FIG. 20B, the total load P ₀ applied when the paper feed tray 8 is pulled out from the set position is reduced by the pulling force P ₁ , the load P ₅ , the sliding load P ₃ by the pulling device 70. is the sum of the force _{P 4.} That is, the total load P ₀ is represented by P ₀ = P ₁ + P ₅ + P ₃ + P ₄ . Thus, pull-out operation force F _out required when pulling out the paper tray 8 from the set position _(N) requires a total load P ₀ equal magnitude in the direction opposite to the direction in which the total load P ₀ is applied.

For example, the pulling force P ₁ (N) = 12N ± 2N by the pulling device 70, the load P ₅ (N) = 3N ± 1N, the sliding load P ₃ (N) = 3N ± 1N, and the damping force P ₄ (N) = When 2N ± 1N, the total load P ₀ (N) is P ₀ (N) = 12N + 4N + 4N + 3N = 23N. Accordingly, the pulling operation force F _out (N) is also required by 23N. Thus, when the force pulling by pulling apparatus 70 P ₁ is the average magnitude within the specified, and it is assumed that each load P ₃ to P ₅ is the largest within the specified drawer operating force F _{out (N)} Becomes 23N and exceeds 22.2N. Therefore, the provisions of the rehabilitation law Article 508 issued by the US federal government where the operating force must be 5 pounds weight (22.2 N) or less cannot be satisfied.

Therefore, in the present embodiment, as described above, when the paper feed tray 8 is pulled out, the connection between the second gear 720 and the third gear 721 is released, so that the damping force (load) by the speed-dependent damper 722 is released. P ₄ does not come into action. Therefore, the pulling operation force F _out (N) in the present embodiment is F _out (N) = 12N + 4N + 4N = 20N. Therefore, in the present embodiment, even in the above case, the pulling operation force F _out (N) is 5 pounds weight (22.2 N) or less, and the provisions of the Rehabilitation Act Article 508 issued by the US federal government Can be met.

  Next, referring to FIG. 21, the pull-in speed of the paper feed tray 8 by the pull-in device 70 according to the present embodiment, and a conventional pull-in device having a configuration that does not have a speed-dependent damper and a speed-dependent damper. A comparison with the pulling speed of the pulling apparatus having the structure will be described.

  In FIG. 21, a graph indicated by a broken line is a graph showing a pull-in speed of the paper feed tray by a pull-in device having a configuration that does not have a speed-dependent damper. Further, the graph indicated by the alternate long and short dash line is a graph showing the pull-in speed of the paper feed tray by the pull-in device having the conventional structure having the speed-dependent damper. Furthermore, the graph shown by a solid line is a graph showing the drawing speed of the paper feed tray 8 by the drawing device 70 according to the present embodiment.

  As shown in FIG. 21, in the pull-in device having no speed-dependent damper, after the paper feed tray is pulled at a pull-in speed of about 600 mm / S and a relatively large impact is generated, Attenuate and stop.

  In the case of a pull-in device having a conventional structure having a speed-dependent damper, the paper feed tray is pulled in at a pull-in speed of about 80 mm / S, and gradually decelerates when a load is applied to the coupling portion of the lifting device. Stop.

  On the other hand, in the pull-in device 70 according to the present embodiment, the paper feed tray 8 is pulled at a pull-in speed of about 80 mm / S from the start of pull-in to immediately before the set position. Thereafter, when the paper feed tray 8 reaches just before the set position, the connection between the second gear 720 and the third gear 721 is released, and the damping force (load) by the speed-dependent damper 722 does not act, so a solid line graph Stop without increasing the pull-in speed as shown by. As described above, in the pull-in device 70 according to the present embodiment, even if the damping force (load) by the speed-dependent damper 722 is released, the pull-in speed does not increase, so the pulling operation feeling of the paper feed tray 8 is deteriorated. That's not true.

  As described above, in the present embodiment, when the paper feed tray 8 is retracted, the pull-in unit 71 is released by releasing the engagement between the first gear 711 and the second gear 720 immediately before the paper feed tray 8 reaches the set position. Since the engagement with the damper unit 72 is released, the load for pulling in the paper feed tray 8 is released immediately before the set position. For this reason, it is possible to reliably pull the paper feed tray 8 to the proper mounting position while reducing the pulling force of the paper feed tray 8 while reducing the pulling speed of the paper feed tray 8.

  In the present embodiment, the notch 711 a of the first gear 711 faces the second gear 720 immediately before the paper feed tray 8 reaches the set position, and the first gear 711 and the second gear 720 A gap is formed between them. Accordingly, the engagement between the first gear 711 and the second gear 720 can be reliably released immediately before the paper feed tray 8 reaches the set position.

  In this embodiment, the first spring 713 and the second spring 714, which are tension springs, are used as the urging member. However, as the urging member, a compression spring, a leaf spring, rubber, or resin is used. An elastic member such as may be used.

  In the present embodiment, the example in which the pull-in device 70 of the present invention is provided for pulling in the paper feed tray 8 has been described. However, the present invention is not limited to this. For example, the process cartridge is removed from the main body of the device by opening the exterior cover, etc., and pulling it out to the front side, and a new process cartridge is slid from the front side to the back side and attached to the main body of the device. The pull-in device 70 of the present invention may be used for mounting the cartridge main body. Further, when the toner bottle is slid with respect to the apparatus main body and replaced, the retracting apparatus of the present invention may be used for mounting the apparatus main body of the toner bottle.

  Further, in the present embodiment, when the paper feed tray 8 reaches just before the set position, the first gear 711 has a notch portion for releasing the engagement between the first gear 711 and the second gear 720. 711a is provided, but any configuration may be used as long as the engagement between the first gear 711 and the second gear 720 is released when the paper feed tray 8 reaches immediately before the set position. . For example, even when the length of the arc of the first gear 711 is shortened so that the engagement between the first gear 711 and the second gear 720 is released when the paper feed tray 8 reaches just before the set position. Good.

  As described above, the pull-in device and the image forming apparatus according to the present invention reduce the pull-in speed of the paper feed tray and prevent a reduction in the pull-in force of the paper feed tray to ensure that the paper feed tray is in the proper mounting position. And an image forming apparatus comprising, for example, an electrophotographic copying machine, a facsimile apparatus, a printer apparatus, and the like provided with the pull-in device. Useful as such.

1 Digital MFP (image forming device)
8, 9, 10, 11 Feed tray 70 Pull-in device 71 Pull-in unit (pull-in means)
72 Damper unit (deceleration means)
100 pin 701 guide groove 710 first lever (rotating member)
711 1st gear (gear part)
711a Notch 712 Second lever 713 First spring (retraction force generating member)
714 Second spring (retraction force generating member)
720 Second gear (engagement gear)
721 Third gear (deceleration force generating member)
722 Speed-dependent damper (deceleration force generating member)

Japanese Patent Laid-Open No. 2007-70068

Claims (3)

Pull-in means for pulling a paper feed tray that is detachably attached to the apparatus main body to a set position, and reduction means for reducing the pull-in speed when pulling in the paper feed tray by engaging with the pull-in means. A retraction device,
The pull-in means is provided on a pull-in force generating member that generates a pull-in force that pulls the paper-feed tray into a set position, a rotary member that rotates according to the pull-in of the paper-feed tray, and the rotary member. A gear portion that rotates about a rotation fulcrum of the rotation member;
The deceleration means includes a deceleration force generation member that generates a deceleration force, and an engagement gear that is coupled to the deceleration force generation member and engages with the gear portion.
The gear unit, so that the paper feed tray to release the engagement between the engaging gear immediately before reaching the set position, characterized in that it have a notch that is cut out radially inwardly Retraction device. The pulling device according to claim 1 , wherein the speed reducing unit releases the connection between the speed reducing force generating member and the engagement gear when the paper feed tray is pulled out. An image forming apparatus comprising the pull-in device according to claim 1 .

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