JP2009242025A - Image forming device - Google Patents

Image forming device Download PDF

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Publication number
JP2009242025A
JP2009242025A JP2008088531A JP2008088531A JP2009242025A JP 2009242025 A JP2009242025 A JP 2009242025A JP 2008088531 A JP2008088531 A JP 2008088531A JP 2008088531 A JP2008088531 A JP 2008088531A JP 2009242025 A JP2009242025 A JP 2009242025A
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Japan
Prior art keywords
paper
roller
paper feed
sheet
feed roller
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Pending
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JP2008088531A
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Japanese (ja)
Inventor
Masakazu Uehara
雅和 上原
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Kyocera Mita Corp
京セラミタ株式会社
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Priority to JP2008088531A priority Critical patent/JP2009242025A/en
Publication of JP2009242025A publication Critical patent/JP2009242025A/en
Pending legal-status Critical Current

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Abstract

<P>PROBLEM TO BE SOLVED: To provide a paper carrying device capable of restraining an abnormal sound caused when a twist of a driving shaft of a paper feeding roller is released, when delivering paper to register roller pairs from the paper feeding roller. <P>SOLUTION: This image forming device has a paper feeding part 64 having a casing M, a paper placing part 65, the paper feeding roller 66, a lifting member 603 for pressing the paper T to the paper feeding roller 66 and a separation member 615 arranged so as to press the paper T between the paper feeding roller 66 and itself, and the register roller pairs 80 arranged inside the casing M and sending out the paper T to the downstream side in the carrying direction D1 by being rotatingly driven after a chip part T1 of the paper T fed from the paper feeding roller 66 abuts once in a stopping state. The separation member 615 releases pressing of a lift plate 603 and the separation member 615 to the paper feeding roller 66 before rotatingly driving the register roller pairs 80 after the chip part T1 in the carrying direction D1 of the paper T contacts with the register roller pairs 80. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a sheet conveying apparatus, an image forming apparatus, and a sheet conveying mechanism having a sheet feeding unit that feeds a sheet placed on a sheet placing unit into a housing.
  In general, an image forming apparatus such as a printer has a manual feed tray, and includes a manual paper feed unit that feeds paper placed on the manual feed tray into the inside of the housing. The manual paper feed unit generally includes a paper feed roller disposed above the manual feed tray, a lift plate that moves the paper placed on the manual tray toward or away from the paper feed roller, and the paper feed roller. (See, for example, Patent Document 1 below). According to the image forming apparatus having the manual sheet feeding unit configured as described above, the sheet feeding roller is rotated in a state where the sheet is sandwiched between the sheet feeding roller and the separating member, thereby feeding the sheet into the housing. can do.
  In the image forming apparatus, a pair of registration rollers is provided between a paper feed roller and an image forming unit that forms an image on a sheet. The registration roller pair is a pair of rollers for performing skew (oblique feeding) correction and adjusting timing with a toner image before the sheet conveyed from the sheet feeding roller is sent to the image forming unit.
  In the image forming apparatus, it is preferable not to provide a roller (hereinafter also referred to as an “intermediate transport roller”) used for transporting paper between the paper feed roller and the registration roller pair. This is because an increase in cost (such as part costs) can be suppressed by omitting the intermediate conveyance roller. The intermediate conveyance roller is a roller for delivering the paper conveyed from the paper supply roller and conveying the delivered paper to the registration roller pair.
Japanese Patent Laid-Open No. 11-343037
  However, in an image forming apparatus that does not include an intermediate conveyance roller between the paper feed roller and the registration roller pair, there is a problem that abnormal noise occurs due to the paper feed roller. Specifically, in an image forming apparatus that is not provided with an intermediate conveyance roller, it is necessary to transfer paper from the paper feed roller to the registration roller pair, so that the paper discharged from the paper feed roller is received by the registration roller pair. It is necessary to drive (rotate) the paper feed roller until it is delivered. This is because if the drive of the paper feed roller is stopped before the paper is delivered to the registration roller pair, the paper may not be delivered to the registration roller pair.
  The sheet delivered to the registration roller pair is not immediately discharged from the registration roller pair, but is discharged after the correction and adjustment of the sheet. Therefore, a reaction force is generated on the sheet positioned between the paper feed roller and the registration roller pair in a direction opposite to the sheet conveyance direction (hereinafter also referred to as “anti-conveyance direction”). This reaction force becomes particularly large when the rigidity of the paper is high.
  Since the feed roller is driven (rotated) against this reaction force, the drive shaft of the feed roller is twisted. In general, the drive shaft of the paper feed roller rotates when a paper feed drive gear fixed to the drive shaft is driven by another gear that meshes with the paper feed drive gear. In that case, when the meshing of both gears is released, the twist of the drive shaft of the paper feed roller is released, and there is a problem that abnormal noise occurs between the two gears.
  The problem that this abnormal noise occurs can also occur in a paper transport device and a paper transport mechanism that do not include an image forming unit.
  Accordingly, the present invention has a paper feed unit that feeds the paper placed on the paper placement unit into the inside of the housing, and when the paper is transferred from the paper feed roller to the registration roller pair, the paper feed roller An object of the present invention is to provide a sheet conveying apparatus, an image forming apparatus, and a sheet conveying mechanism that can suppress abnormal noise caused by untwisting the drive shaft.
  The present invention includes a housing, a paper placement portion on which paper is placed, a paper feed roller that feeds the paper placed on the paper placement portion into the housing, and the paper placement. An elevating member that presses the paper against the paper feed roller by moving up and down from the placement unit toward the paper feed roller, and is arranged so as to press the paper between the paper feed roller and the paper A sheet feeding unit having a separating member for separating the bundles one by one, and a front end portion of the sheet which is disposed inside the housing and is fed from the sheet feeding roller in a stopped state is once contacted And a pair of registration rollers that are driven to rotate to feed the paper downstream in the transport direction, and the scooping member is after the leading end in the paper transport direction is in contact with the pair of registration rollers. Before the registration roller pair is driven to rotate, About the paper transfer device for releasing the pressure of the serial lift member and said handling member.
  In addition, the separation member releases the reaction force in the direction opposite to the conveyance direction of the sheet when the sheet is transferred from the sheet feeding roller to the registration roller pair. It is preferable to move in a direction away from the roller.
  Further, it is preferable that the whirling member moves in a direction away from the paper feed roller in conjunction with an operation of releasing the pressing of the lifting member against the paper feed roller.
  The elevating member has an engaging portion, and the separating member has an engaged portion that engages with the engaging portion when the elevating member moves in a direction away from the paper feed roller. After the pressing of the elevating member against the paper feed roller is released, the elevating member moves away from the paper feed roller in a state where the engaging portion and the engaged portion are engaged. Accordingly, it is preferable that the separating member moves in a direction away from the sheet feeding roller.
  The paper feed roller is preferably connected to a paper feed drive shaft mainly composed of a resin member, and is rotated by driving the paper feed drive shaft.
  Further, the input gear, the paper feed drive gear connected to the paper feed roller, the missing gear that selectively meshes with the input gear and the paper feed drive gear, and the lifting member directly or indirectly A push-up member that pushes up to the upper side, a push-up member that pushes up the push-up member in accordance with the rotation, is urged in the rotational direction by an urging force, and rotates according to the rotation of the tooth-missing gear, A control cylinder having a locking claw; an actuator engaged with the locking claw; and an actuator rotating section for rotating the operating element. The control cylinder includes the actuator. In the state where it is not engaged with the pawl, the locking claw and the input gear are not meshed with each other and the latching gear and the paper feed drive gear are not meshed with each other. Engagement with the actuator When released, the toothless gear is rotated by the biasing force, the toothless gear and the input gear begin to mesh with each other, and the rotating cam is rotated, whereby the push-up member is pushed up, and the push-up member pushes the push-up member As the elevating member is pushed up, the paper is pressed against the paper feed roller by the elevating member, and the paper feed roller rotates by the meshing of the toothless gear and the paper feed drive gear. It is preferable that paper is fed into the housing.
  In addition, after the pressing of the elevating member and the separating member to the paper feeding roller is released and the paper is fed toward the registration roller pair, the paper feeding member feeds the next paper to the paper feeding roller. It is preferable to press between the two.
  The present invention also relates to an image forming apparatus further comprising an image forming unit that forms an image on the paper fed from the paper feed roller in the housing of the paper transport device.
  Further, the present invention provides a paper placement unit on which paper is placed, a paper feed roller placed on the paper placement unit, and ascending and descending from the paper placement unit toward the paper feed roller. An elevating member that presses the paper against the paper feed roller, a webbing member that is arranged so as to press the paper between the paper feed roller and that rolls the paper bundle one by one, and in a stopped state A pair of registration rollers that, after the leading end of the paper fed from the paper feed roller is once brought into contact, rotates and sends the paper to the downstream side in the transport direction; A sheet conveying mechanism that releases the pressing of the elevating member and the separating member against the sheet feeding roller after the leading end in the sheet conveying direction is in contact with the pair of registration rollers and before the pair of registration rollers is rotationally driven. About.
  According to the present invention, when the sheet is transferred from the sheet feed roller to the registration roller pair, it is possible to suppress noise caused by the twisting of the drive shaft of the sheet feed roller being released.
The best mode for carrying out the present invention will be described below with reference to the drawings.
With reference to FIG. 1, the overall structure of a printer 1 as an image forming apparatus in the present embodiment will be described. FIG. 1 is a left side view for explaining the arrangement of each component in the printer 1. In the present embodiment, the side (the right side in FIG. 1) on which a later-described manual feed tray 65 is disposed is the front side of the printer 1.
The printer 1 includes an image forming unit that forms a predetermined image on the paper T based on predetermined image information, and a paper feed / discharge unit that feeds the paper T to the image forming unit and discharges the paper T on which the image is formed. Part.
As shown in FIG. 1, the image forming unit includes a photosensitive drum 2, a charging unit 10, a laser scanner unit 4, a developing device 16, a toner cartridge 5, a toner supply device 6, a transfer roller 8, And a fixing device 9.
The paper supply / discharge unit includes a paper supply cassette 52, a manual feed tray 65, a registration roller pair 80, and a conveyance path L for the paper T.
  The photosensitive drum 2 is made of a cylindrical member and functions as an image carrier. The photosensitive drum 2 is disposed in the apparatus main body (housing) M in a manner that can rotate around a rotation axis perpendicular to FIG. An electrostatic latent image is formed on the surface of the photosensitive drum 2.
  The charging unit 10 is disposed above the photosensitive drum 2. The charging unit 10 uniformly charges the surface of the photosensitive drum 2 positively (plus polarity).
The laser scanner unit 4 is disposed above the photosensitive drum 2 and spaced from the photosensitive drum 2. The laser scanner unit 4 includes a laser light source (not shown), a polygon mirror, a polygon mirror driving motor, and the like.
The laser scanner unit 4 scans and exposes the surface of the photosensitive drum 2 based on image information output from an external device such as a PC (personal computer). By scanning exposure by the laser scanner unit 4, the electric charge charged on the surface of the photosensitive drum 2 is removed. As a result, an electrostatic latent image is formed on the surface of the photosensitive drum 2.
  The developing device 16 is disposed in front of the photosensitive drum 2 (on the right side in FIG. 1). The developing device 16 develops a monochrome (usually black) toner image on the electrostatic latent image formed on the photosensitive drum 2. The developing device 16 includes a developing roller 17 that can be disposed facing the photosensitive drum 2 and a stirring roller 18 for stirring the toner.
The toner cartridge 5 stores toner supplied to the developing device 16.
The toner supply device 6 supplies the toner stored in the toner cartridge 5 to the developing device 16.
  The drum cleaning device 11 is disposed behind the photosensitive drum 2 (on the left side in FIG. 1). The drum cleaning device 11 removes toner and deposits remaining on the surface of the photosensitive drum 2.
  The transfer roller 8 transfers the toner image developed on the surface of the photosensitive drum 2 to the paper T. A transfer bias for transferring the toner image developed on the photosensitive drum 2 to the paper T is applied to the transfer roller 8 by a voltage application unit (not shown).
  The transfer roller 8 is brought into contact with and separated from the photosensitive drum 2. Specifically, the transfer roller 8 is configured to be movable between a contact position where the transfer roller 8 is in contact with the photosensitive drum 2 and a spaced position where the transfer roller 8 is separated from the photosensitive drum 2. Specifically, the transfer roller 8 is moved to the contact position when the toner image developed on the photosensitive drum 2 is transferred to the paper T, and is moved to the separation position in other cases.
  The paper T is sandwiched between the photosensitive drum 2 and the transfer roller 8 and pressed against the surface of the photosensitive drum 2 (the side on which the toner image is developed). In this way, the transfer nip N is formed, and the toner image developed on the photosensitive drum 2 is transferred onto the paper T.
  The fixing device 9 melts the toner constituting the toner image transferred onto the paper T and fixes it on the paper T. The fixing device 9 includes a heating roller 9a heated by a heater, and a pressure roller 9b pressed against the heating roller 9a. The heating roller 9a and the pressure roller 9b convey the paper T onto which the toner image has been transferred so as to sandwich the paper T. By transporting the paper T so as to be sandwiched between the heating roller 9a and the pressure roller 9b, the toner transferred onto the paper T is melted and fixed.
The paper feed cassette 52 is disposed below the apparatus main body M. The paper feed cassette 52 is disposed on the front side (right side in FIG. 1) of the apparatus body M so as to be able to be pulled out in the horizontal direction. The paper feed cassette 52 includes a placement plate 60 on which the paper T is placed. The paper feed cassette 52 stores the paper T in a state where the paper T is stacked on the placement plate 60. The cassette paper feed unit 51 is disposed at the paper feed side end (the right side end in FIG. 1) of the paper feed cassette 52. The cassette paper feed unit 51 sends out the paper T stored in the paper feed cassette 52 to the transport path L.
The cassette paper feeding unit 51 includes a multi-feed prevention mechanism including a forward feed roller 61 that takes out the paper T placed on the placement plate 60 and a roller pair 63 that feeds the paper T one by one to the transport path L.
  A transport path L for transporting the paper T is formed between the cassette paper feed unit 51 or the manual paper feed unit 64 and the paper discharge unit 50. The conveyance path L includes a first conveyance path L1 from the cassette paper feeding unit 51 to the first junction P1, a second conveyance path L2 from the first junction P1 to the registration roller pair 80, and a transfer from the registration roller pair 80. A third conveyance path L3 to the roller 8, a fourth conveyance path L4 from the transfer roller 8 to the fixing device 9, a fifth conveyance path L5 from the fixing device 9 to the branching portion P3, and a discharge portion from the branching portion P3. And up to 50 sixth transport paths L6.
Moreover, the conveyance path L has the 7th conveyance path L7 from the manual feed tray 65 to the 1st confluence | merging part P1. The first merging portion P1 is a merging portion between the first conveyance path L1 that conveys the paper T from the cassette paper feeding section 51 and the seventh conveyance path L7 that conveys the paper T from the manual feed tray 65.
A second junction P2 is disposed in the middle of the second transport path L2. Furthermore, the conveyance path L has a return conveyance path Lb from the branching part P3 to the second joining part P2. The second junction P2 is a junction between the second conveyance path L2 and the return conveyance path Lb.
  Here, a registration roller pair 80 is disposed on the upstream side (right side in FIG. 1) of the transfer roller 8 in the transport direction of the paper T. The registration roller pair 80 is rotationally driven after the leading end T1 of the paper T fed from the paper feed roller 66 in a stopped state is temporarily brought into contact with the paper T in the transport direction D1 (see FIG. 12A). It is a roller pair sent out to the downstream side. The registration roller pair 80 is a roller pair for correcting skew (oblique feeding) of the paper T and adjusting timing with the toner image.
The return conveyance path Lb is a conveyance path that is provided so that the opposite surface (non-printing surface) to the surface that has already been printed faces the photosensitive drum 2 when performing duplex printing on the paper T.
According to the return conveyance path Lb, the sheet T conveyed from the branching section P3 to the paper discharge section 50 side can be reversed and returned to the second conveyance path L2. A predetermined toner image is transferred onto the non-printing surface of the paper T that has been turned upside down by the return conveyance path Lb.
A manual paper feed unit (paper feed unit) 64 is provided on the front side of the apparatus main body M (on the right side in FIG. 1) and above the paper feed cassette 52. The manual paper feed unit 64 includes a manual tray 65 that is a paper placement unit, and a paper feed roller 66 that is a paper feed roller. The base of the manual feed tray 65 is attached to the vicinity of the entrance of the seventh transport path L7 so as to be rotatable (openable and closable). The manual feed tray 65 constitutes a part of the front surface of the apparatus main body M in the closed state. The paper feed roller 66 takes out the paper T placed on the manual feed tray 65 and sends it out toward the seventh transport path L7.
The manual paper feed unit 64 feeds the paper T placed on the open manual feed tray 65 to the second transport path L2 via the seventh transport path L7 and the first junction P1.
  A paper discharge unit 50 is formed at the end of the sixth transport path L6. The paper discharge unit 50 is disposed on the upper side of the apparatus main body M. The paper discharge unit 50 opens toward the front of the apparatus main body M (to the right in FIG. 1). The paper discharge unit 50 discharges the paper T on which the toner is fixed by the fixing device 9 to the outside of the apparatus main body M.
  On the opening side of the paper discharge unit 50, a paper discharge stacking unit M1 is formed. The paper discharge stacking unit M1 is formed on the upper surface (outer surface) of the apparatus main body M. The paper discharge stacking unit M1 is a part formed by the upper surface of the apparatus main body M being depressed downward. The bottom surface of the paper discharge stacking unit M1 constitutes a part of the top surface of the apparatus main body M. In the paper discharge stacking unit M1, the paper T discharged from the paper discharge unit 50 and having a predetermined image transferred thereon is stacked and stacked.
Next, the conveyance path L will be described in detail. In addition, the conveyance path L is an aggregate of the conveyance paths L1 to L7 and Lb, as will be described later.
A conveyance path L for conveying the paper T is formed between the cassette paper feeding unit 51 or the manual feed tray 65 and the paper discharge unit 50. The conveyance path L includes a first conveyance path L1 from the cassette paper feeding unit 51 to the first junction P1, a second conveyance path L2 from the first junction P1 to the registration roller pair 80, and a transfer from the registration roller pair 80. A third conveyance path L3 to the roller 8, a fourth conveyance path L4 from the transfer roller 8 to the fixing device 9, a fifth conveyance path L5 from the fixing device 9 to the branching portion P3, and a discharge portion from the branching portion P3. And up to 50 sixth transport paths L6.
Moreover, the conveyance path L has the 7th conveyance path L7 from the manual feed tray 65 to the 1st confluence | merging part P1. The first merging portion P1 is a merging portion between the first conveyance path L1 that conveys the paper T from the cassette paper feeding section 51 and the seventh conveyance path L7 that conveys the paper T from the manual feed tray 65.
A second junction P2 is disposed in the middle of the second transport path L2. Furthermore, the conveyance path L has a return conveyance path Lb from the branching part P3 to the second joining part P2. The second junction P2 is a junction between the second conveyance path L2 and the return conveyance path Lb.
The return conveyance path Lb is a conveyance path that is provided so that the opposite surface (non-printing surface) to the surface that has already been printed faces the photosensitive drum 2 when performing duplex printing on the paper T.
According to the return transport path Lb, the paper T once transported from the branching section P3 to the paper discharge section 50 can be reversed and returned to the second transport path L2, so that the non-printing surface of the paper T can be removed. Printing can be performed on the non-printing surface of the paper T facing the photosensitive drum 2.
  Next, guide members 55a, 55b, 55c, 55d, 55e, 55f, 55g, 55h, 55i, 55j, 55k, and 55m that form the conveyance path L together with various rollers will be described. In addition to the guide members 55a to 55m described below, a guide member is appropriately provided for the purpose of improving the transportability of the paper T in the transport path L.
  The first transport path L1 mainly includes a first guide member 55a, an inner surface of the second guide member 55b, and a third guide member 55c. The first guide member 55a gradually changes the transport direction of the paper T discharged from the roller pair 63 upward. The second guide member 55b gradually changes the transport direction of the paper T whose transport direction has been converted upward by the first guide member 55a toward the rear of the apparatus main body M (leftward in FIG. 1). The third guide member 55c is a columnar member provided below the second guide member 55b. When the second guide member 55b does not smoothly change the transport direction of the paper T, the third guide member 55c transports the paper T. It is provided to restrict the direction and guide the leading end of the paper T to the first joining portion P1.
The second transport path L2 is mainly composed of a pair of upper and lower fifth guide members 55e. According to the pair of upper and lower fifth guide members 55e, the paper T conveyed from the first joining portion P1 can be smoothly introduced between the pair of registration rollers 80.
A sensor (not shown) for detecting the paper T is disposed in the second transport path L2. The sensor is disposed immediately before (on the upstream side) the registration roller pair 80 in the transport direction of the paper T. The registration roller pair 80 performs the above correction and timing adjustment based on the detection signal information from the sensor, and conveys the paper T.
The third transport path L3 is mainly composed of a pair of upper and lower sixth guide members 55f. According to the pair of upper and lower sixth guide members 55f, the paper T discharged from the registration roller pair 80 can be smoothly introduced between the photosensitive drum 2 and the transfer roller 8.
A sensor (not shown) for detecting the paper T is disposed in the third transport path L3.
The fourth transport path L4 is mainly composed of a pair of upper and lower seventh guide members 55g. According to the pair of upper and lower seventh guide members 55g, the paper T discharged from between the photosensitive drum 2 and the transfer roller 8 is smoothly introduced between the heating roller 9a and the pressure roller 9b in the fixing device 9. Can be made.
A sensor (not shown) for detecting the paper T is disposed in the fourth transport path L4.
The fifth transport path L5 is mainly composed of a pair of upper and lower eighth guide members 55h. According to the pair of upper and lower eighth guide members 55h, the paper T conveyed from the fixing device 9 can be smoothly introduced into the branch portion P3.
A sensor (not shown) for detecting the paper T is arranged in the fifth transport path L5.
Next, the branch part P3 will be described. The branch part P3 includes a first roller pair 54a and a second roller pair 54b.
The first roller pair 54a includes a first transport roller 53a and a second transport roller 53b. According to the first roller pair 54a, the paper T conveyed from the fifth conveyance path L5 can be conveyed to the sixth conveyance path L6.
  The second roller pair 54b includes a first transport roller 53a and a third transport roller 53c. That is, the first transport roller 53a serves as one roller in the first roller pair 54a and one roller in the second roller pair 54b. According to the second roller pair 54b, it is possible to transport the paper T that is transported in the reverse direction along the sixth transport path L6 during duplex printing toward the return transport path Lb.
The sixth conveyance path L6 is a conveyance path between the branching section P3 and the paper discharge section 50, is curved convexly toward the rear (left side in FIG. 1) of the apparatus main body M, and is directed upward. It extends.
The sixth transport path L6 mainly includes a ninth guide member 55i disposed on the curved inner side and a tenth guide member 55j disposed on the curved outer side. The paper T conveyed from the branching portion P3 is mainly discharged to the tenth guide member 55j while the conveyance direction is changed toward the front (right side in FIG. 1) of the apparatus main body M and upward. It is conveyed toward.
  In the sixth conveyance path L6, a third roller pair 54c is disposed in the vicinity of the paper discharge unit 50. According to the third roller pair 54c, the paper T conveyed through the sixth conveyance path L6 can be discharged from the paper discharge unit 50 to the paper discharge stacking unit M1 of the apparatus main body M. Further, according to the third roller pair 54c, the third roller pair 54c is rotated in the opposite direction to the case where the paper T held by the third roller pair 54c is discharged from the paper discharge unit 50. Then, it can be transported (switched back) toward the branching portion P3 side of the sixth transport path L6.
The seventh transport path L7 mainly includes an outer surface (upper surface) of the second guide member 55b and a fourth guide member 55d disposed above the second guide member 55b. That is, the second guide member 55b constitutes a part of the first conveyance path L1 and also constitutes a part of the seventh conveyance path L7.
According to the second guide member 55b and the fourth guide member 55d, when the paper T placed on the manual feed tray 65 is sent out by the paper feed roller 66, the paper T can be smoothly conveyed to the first junction P1. it can.
  The return conveyance path Lb is a conveyance path that is used when performing so-called double-sided printing (printing) in which toner images (including characters and the like) are printed (printed) on both sides of the paper T. The return conveyance path Lb branches downward from the branch portion P3 and passes below the fifth conveyance path L5, the fixing device 9, the fourth conveyance path L4, the transfer roller 8, the third conveyance path L3, and the registration roller pair 80. Formed. Further, the return conveyance path Lb is convexly curved toward the front (right side in FIG. 1) of the apparatus main body M and extends upward, and merges with the second conveyance path L2 at the second merging portion P2. To be formed.
  The merge direction of the return conveyance path Lb in the second merge section P2 is the positive direction of the second conveyance path L2 (the conveyance direction of the paper T). In other words, the return conveyance path Lb is upstream of the registration roller pair 80 disposed upstream of the transfer roller 8 after the paper T once conveyed from the branching portion P3 to the downstream side of the sixth conveyance path L6 during duplex printing. It is the conveyance path for returning to.
  By the way, the paper T transported from the fifth transport path L5 to the sixth transport path L6 via the branching portion P3 mainly changes the transport direction of the apparatus main body M by the tenth guide member 55j disposed on the curved outer side. It is conveyed while being gradually converted toward the front (right side in FIG. 1) and upward.
  On the other hand, when the sheet T is switched back, the sheet T conveyed by the third roller pair 54c rotating in the reverse direction toward the branching portion P3 through the sixth conveyance path L6 is the tenth disposed outside the curve. While being regulated by the guide member 55j, it is conveyed toward the branch portion P3. Therefore, the paper T is introduced into the second roller pair 54b in the branching portion P3 (not the first roller pair 54a) without providing a member for controlling the transport direction.
  As with the other transport paths, a fourth roller pair 54d that transports the paper T while guiding it is disposed in the return transport path Lb. In addition, a paper detection sensor (not shown) is disposed at a predetermined position on the return conveyance path Lb.
  The return conveyance path Lb mainly includes a pair of upper and lower eleventh guide members 55k and 55k between the branch portion P3 and the fourth roller pair 54d. According to the pair of upper and lower eleventh guide members 55k and 55k, the paper T conveyed from the branching portion P3 can be smoothly introduced into the fourth roller pair 54d.
  The return conveyance path Lb is mainly composed of a pair of upper and lower twelfth guide members 55m and 55m between the fourth roller pair 54d and the second joining portion P2. According to the pair of upper and lower twelfth guide members 55m and 55m, the paper T conveyed from the fourth roller pair 54d can be smoothly conveyed to the second joining portion P2.
Next, a configuration relating to a characteristic part of the printer 1 of the present embodiment will be described with reference to the drawings.
As shown in FIG. 1, the printer 1 of the present embodiment is provided between an apparatus main body M, the image forming unit disposed inside the apparatus main body M, a paper feed roller 66, and an image forming unit. The registration roller pair 80 for feeding the paper T fed from the paper feed roller 66 to the image forming unit.
  FIG. 2 is an exploded perspective view of the manual sheet feeder 64 viewed from obliquely above on the right side surface of the apparatus main body M. FIG. FIG. 3 is an exploded perspective view of the manual sheet feeder 64 as viewed obliquely from the left side of the apparatus main body M. FIG. 4 is a longitudinal sectional view showing the paper feed roller 66, the lift plate 603, the separating member 615, and the like. FIG. 5 is an exploded perspective view of the missing gear 607 and the like viewed obliquely from the left side of the apparatus main body M.
  FIG. 6 is an exploded perspective view of the control cylinder 608, the actuator 612, and the like viewed from the left side of the apparatus main body M. FIG. 7 is an exploded perspective view of the rotating cam 609, the toothless gear 607, and the like viewed obliquely from the upper right side of the apparatus main body M. FIG. 8 is an exploded left side view sequentially showing operations of the control cylinder 608, the actuator 612, and the like. 9 and 10 are exploded right side views sequentially showing the operation of the rotating cam 609, the lift lever 604, and the like.
  As shown in FIGS. 2 to 10, the manual paper feed unit (paper feed unit) 64 includes a manual tray (paper placement unit) 65, a paper feed roller (paper feed roller) 66, and a paper feed drive shaft 601. The paper feed drive gear 602, the lift plate (elevating member) 603, the lift lever (pushing member) 604, the push-down bracket 605, the cam shaft 606, the first toothed portion 607a and the second toothed portion 607b. A toothless gear 607 having a control cylinder 608 having a locking claw 608a, a rotating cam 609, an input gear 610, a solenoid (actuator rotating portion) 611, an actuator 612, a first spring 613, A second spring 614 and a rolling member 615 having a receiving portion 615a are provided.
  The manual feed tray 65 is a tray (placement unit) on which paper T to be manually fed is placed. As shown in FIGS. 2 to 4 and the like, a lift plate 603 (details will be described later) is disposed on the downstream side of the transport direction D1 (see FIG. 12A) of the paper T on the placement surface of the manual feed tray 65. ing.
  The paper feed roller 66 is a roller (roller) that feeds the paper T placed on the manual feed tray 65 into the inside of the apparatus main body M. As shown in FIGS. 2 to 4 and the like, the paper feed roller 66 has a substantially cylindrical shape, and the axis of the paper feed roller 66 is perpendicular to the conveyance direction D1 of the paper T (hereinafter referred to as “orthogonal direction D3” (see FIG. 2)). Say). The paper feed roller 66 is disposed above the manual feed tray 65 and separated from the placement surface of the manual feed tray 65 and the lift plate 603. The paper feed roller 66 is located at the approximate center in the orthogonal direction D3 in the manual paper feed unit 64. The paper feed roller 66 is connected to one end of a paper feed drive shaft 601 (details will be described later), and rotates when the paper feed drive shaft 601 is driven.
  As shown in FIGS. 2, 3, etc., the paper feed drive shaft 601 is a shaft for driving the paper feed roller 66, and is connected to one of the substantially circular bottom surfaces of the substantially cylindrical paper feed roller 66. The paper feed drive shaft 601 has a paper feed roller 66 connected to one end thereof, and rotates the paper feed roller 66 in the axial direction. The other substantially circular bottom surface side of the substantially cylindrical sheet feeding roller 66 is rotatably supported by a support shaft 619 (see FIG. 2).
  The paper feed drive shaft 601 is mainly composed of a resin member. The phrase “consisting mainly of a resin member” means that all or most of the paper feed drive shaft 601 is made of a resin member. For example, a part of the paper feed drive shaft 601 is a metal member. This means that the metal member hardly contributes to the improvement of the rigidity against the torsion of the entire paper feed drive shaft 601.
  As shown in FIGS. 2, 3, and the like, the paper feed drive gear 602 is a gear that transmits a driving force to the paper feed drive shaft 601, and is connected to the other end side of the paper feed drive shaft 601. That is, the paper feed drive gear 602 is indirectly connected to the paper feed roller 66 via the paper feed drive shaft 601. The paper feed drive gear 602 is disposed at a position that meshes with the inner portion in the thickness direction (the portion where the second missing tooth portion 607b is provided) in the missing tooth gear 607 (described later in detail).
  As shown in FIGS. 2, 3, 4, and the like, the lift plate 603 is a member that presses the paper T against the paper feed roller 66 by moving up and down from the manual feed tray 65 toward the paper feed roller 66. That is, the lift plate 603 is a plate-like member that causes the paper T placed on the manual feed tray 65 to approach or separate from the paper feed roller 66. The lift plate 603 is disposed below the paper feed roller 66.
  The lift plate 603 has an engaging portion 603b. The engaging portion 603 b is provided on the lower surface (the surface on the opposite side of the paper feed roller 66) at the downstream end of the lift plate 603 in the transport direction of the paper T. When the lift plate 603 moves in a direction away from the paper feed roller 66, the engagement portion 603 b can be shaped, arranged, or the like if it can engage with an engagement portion 615 b (described later) of the winding member 615. There is no particular limitation.
  The lift plate 603 is urged in the direction approaching the paper feed roller 66 by the extension force (repulsive force) of the spring member 620. However, the lift plate 603 is pressed in a direction away from the sheet feeding roller 66 by a push-down bracket 605 (details will be described later). Therefore, the push-down bracket 605 is pressed upward by a lift lever 604 (details will be described later). In the absence state, the lift plate 603 is not close to the paper feed roller 66.
  As shown in FIGS. 2 and 3, the push-down bracket 605 is a member that is integrally connected to the lift plate 603 and extends from the manual feed tray 65. The push-down bracket 605 is connected to the paper feed drive gear 602 side of the lift plate 603.
  When the push-down bracket 605 is pressed upward by the lift lever 604, the second receiving portion 603a is located at a position where the lift plate 603 comes into contact with the paper feed roller 66 in a state where the lift plate 603 approaches the paper feed roller 66. Is provided. The second receiving portion 603a is formed of a material that exhibits a desired slipperiness when the paper T is sandwiched between the paper feeding rollers 66.
  As shown in FIGS. 5, 7, 9, 10, etc., the lift lever 604 is a lever-like member having a first protrusion 604 a that protrudes upward and a second protrusion 604 b that protrudes downward. . The lift lever 604 rotates the lift plate 603 upward by pressing the push-down bracket 605 integrated with the lift plate 603 upward at the first convex portion 604a, and approaches the paper feed roller 66. Move in the direction. That is, the lift lever 604 pushes up the lift plate 603 indirectly via the push-down bracket 605. Further, the lift lever 604 contacts the arcuate peripheral surface 609a and the bent peripheral surface 609b (details will be described later) of the rotating cam 609 at the second convex portion 604b, and is pressed upward by the rotating cam 609.
  As shown in FIGS. 2, 5, 8, and the like, the missing tooth gear 607 has a first missing tooth portion 607 a and a second missing tooth portion 607 b, and is disposed below the paper feed drive gear 602. The first missing tooth portion 607a and the second missing tooth portion 607b are portions where the teeth in the missing tooth gear 607 are missing. The first tooth missing portion 607a is provided on the outside in the thickness direction (outside the orthogonal direction D3) of the tooth missing gear 607, and the second tooth missing portion 607b is located on the inside in the thickness direction (inside the orthogonal direction D3) of the missing tooth gear 607. Is provided. That is, the first tooth missing portion 607 a and the second tooth missing portion 607 b are formed in two rows in the thickness direction of the tooth missing gear 607. The first tooth missing portion 607a and the second tooth missing portion 607b are provided at positions corresponding to the input gear 610 (details will be described later) and the paper feed drive gear 602, respectively. The circumferential positions of the missing tooth gear 607 are shifted from the first missing tooth portion 607a and the second missing tooth portion 607b. The missing gear 607 selectively meshes with the input gear 610 and the paper feed drive gear 602, respectively.
As shown in FIG. The missing gear 607 and the like are accommodated in the casing 616.
As shown in FIG. 5, a cam shaft 606 is formed outside the orthogonal direction D <b> 3 in the axis of the missing gear 607. By the cam shaft 606, the missing gear 607 is fixed inside the casing 616.
  As shown in FIGS. 5, 8, etc., the control cylinder 608 is provided on the outer side surface in the orthogonal direction D <b> 3 of the missing tooth gear 607 so as to surround the axis of the missing tooth gear 607. On the peripheral surface of the control cylinder 608, a locking claw 608a protruding in the radial direction is provided. The control cylinder 608 rotates according to the rotation of the missing gear 607. The locking claw 608a is locked by an actuator 612 (details will be described later). When the locking claw 608 a is locked to the operating element 612, the rotation of the toothless gear 607 connected to the control cylinder 608 is restricted.
  As shown in FIGS. 2, 7, 9, 10, and the like, the rotating cam 609 is fixed to the inner end portion in the orthogonal direction D <b> 3 on the axis of the toothless gear 607. The rotating cam 609 has a shape in which a part of a disk-like member is missing due to a straight line bent into a substantially “<” shape. The rotating cam 609 has an arcuate arcuate circumferential surface 609a and a bent linear bent circumferential surface 609b when viewed in the thickness direction. A spring locking portion 609c that locks one end of a second spring 614 (details will be described later) is provided on the outer side surface of the rotating cam 609 in the orthogonal direction D3. The rotating cam 609 pushes up the lift lever 604 according to the rotation, and is urged in the rotation direction by the urging force of the second spring 614, and rotates the missing gear 607 by the urging force.
  As shown in FIG. 5, FIG. 8, etc., the input gear 610 is a gear that transmits the driving force transmitted from a predetermined driving source to the missing gear 607 and inputs it. The input gear 610 is disposed at a position that meshes with a portion on the outer side in the thickness direction of the missing gear 607 (a portion where the first toothed portion 607a is provided).
  As shown in FIGS. 6, 8, etc., the solenoid 611 functions as an actuator rotating section that rotates the actuator 612. The operating element 612 has a tip 612a formed in a bowl shape, and a first spring 613 is connected to the other end 612b. The operating element 612 rotates about a rotation shaft (not shown), and the distal end portion 612a can approach or separate from the locking claw 608a of the control cylinder 608.
  The actuator 612 is biased in a direction in which the other end 612 b side approaches the solenoid 611 by the contraction force of the first spring 613. Therefore, when the solenoid 611 is not operated, the tip 612a side of the actuator 612 is biased in a direction approaching the locking claw 608a of the control cylinder 608, the actuator 612 rotates, and the tip 612a is moved. Engages with the locking claw 608a. In a state where the tip 612a of the actuator 612 is engaged with the locking claw 608a, the control cylinder 608 does not rotate.
  On the other hand, when the solenoid 611 is actuated, the operating element 612 is rotated while the first spring 613 is extended, and the tip 612 a side of the operating element 612 moves in a direction approaching the solenoid 611. Therefore, the tip 612a of the actuator 612 is detached from the locking claw 608a of the control cylinder 608. When the tip 612a of the actuator 612 is disengaged from the locking claw 608a, the control cylinder 608 can be rotated.
As shown in FIGS. 2, 7, 9, 10, etc., one end of the second spring 614 is locked to the spring locking portion 609 c of the rotating cam 609 and the other end is the casing. It is connected to a spring connecting portion 617 provided at 616. Accordingly, the second spring 614 is located at a position where the spring engaging portion 609c is closest to the spring connecting portion 617 (that is, a position where the rotation center of the rotating cam 609, the spring engaging portion 609c, and the spring connecting portion 617 are arranged in a straight line. ), A biasing force that biases the rotating cam 609 is developed so that the rotating cam 609 rotates about its rotation axis.
However, as described above, since the control cylinder 608 does not rotate in a state where the distal end portion 612a of the actuator 612 is engaged with the locking claw 608a, the rotating cam 609 connected to the control cylinder 608 also does not rotate.
  As shown in FIGS. 2 to 4 and the like, the separating member 615 is a member disposed so as to press the paper T between the paper feeding rollers 66. The separating member 615 is a member that separates a bundle of sheets T one by one, and is disposed on the downstream side of the sheet T conveyance direction D1 (see FIG. 12A) below the sheet feeding roller 66. The separating member 615 rotates with respect to the apparatus main body M and approaches or separates from the paper feed roller 66.
The spreading member 615 has an engaged portion 615b. The engaged portion 615b is not particularly limited in its shape and arrangement as long as it can be engaged with the engaging portion 603b when the lift plate 603 moves away from the paper feed roller 66.
The separating member 615 includes a receiving portion 615 a that receives the paper T that is conveyed by the rotation of the paper supply roller 66. The receiving portion 615 a is provided in a portion of the separating member 615 that faces the paper feed roller 66. The receiving portion 615a is formed of a material that exhibits desired slipperiness when the paper T is sandwiched between the paper feeding rollers 66.
  As shown in FIG. 4, the separating member 615 is urged to rotate in the direction approaching the sheet feeding roller 66 by the extension force (repulsive force) of the third spring 618 provided in the lower portion thereof. .
Next, the operation of the printer 1 of the present embodiment will be briefly described with reference to FIG.
First, the case where one side printing of the paper T stored in the paper feed cassette 52 is described.
The paper T stored in the paper feed cassette 52 is sent out to the first transport path L1 by the forward feed roller 61 and the roller pair 63, and then the registration roller pair 80 through the first joining portion P1 and the second transport path L2. It is conveyed to.
In the registration roller pair 80, skew correction of the paper T and timing adjustment with the toner image are performed.
The paper T discharged from the registration roller pair 80 is introduced between the photosensitive drum 2 and the transfer roller 8 via the third conveyance path L3. A toner image is transferred onto the paper T between the photosensitive drum 2 and the transfer roller 8.
Thereafter, the paper T is discharged from between the photosensitive drum 2 and the transfer roller 8 and is introduced between the heating roller 9a and the pressure roller 9b in the fixing device 9 through the fourth conveyance path L4. The toner is melted and fixed on the paper T by the fixing device 9.
Next, the paper T is discharged from the paper discharge unit 50 to the paper discharge stacking unit M1 by the third roller pair 54c through the fifth transport path L5, the branching section P3, and the sixth transport path L6.
In this way, single-sided printing of the paper T stored in the paper feed cassette 52 is completed.
  When single-sided printing of the paper T placed on the manual feed tray 65 is performed, the paper T placed on the manual feed tray 65 is sent out to the seventh transport path L7 by the paper feed roller 66, and then the first joining portion. It is conveyed to the registration roller pair 80 via P1 and the second conveyance path L2. Subsequent operations are the same as the one-side printing operation of the paper T accommodated in the paper feed cassette 52 described above, and a description thereof will be omitted.
Next, the operation of the printer 1 when performing duplex printing will be described.
In the case of single-sided printing, as described above, the single-side printed paper T is discharged from the paper discharge unit 50 to the paper discharge stacking unit M1, and the printing operation is completed.
On the other hand, when performing double-sided printing, the paper T that has been printed on one side is reversed from the front and back of the single-sided printing via the return conveyance path Lb, and is conveyed again to the registration roller pair 80. Double-sided printing is performed on the paper T.
  More specifically, the operation is the same as the above-described single-side printing operation until the single-side printed paper T is discharged from the paper discharge unit 50 by the third roller pair 54c. Thus, in the case of double-sided printing, the rotation of the third roller pair 54c is stopped and rotated in the opposite direction while the paper T printed on one side is held by the third roller pair 54c. When the third roller pair 54c is thus rotated in the reverse direction, the paper T held by the third roller pair 54c is moved in the reverse direction (from the paper discharge unit 50 to the branching unit P3). Transported in the direction of heading).
  As described above, when the paper T is transported in the reverse direction along the sixth transport path L6, the paper T is introduced into the second roller pair 54b (not the first roller pair 54a). The paper T then joins the second transport path L2 via the return transport path Lb and the second joining portion P2. Here, the paper T is turned upside down from the one-side printing.
  Further, the paper T is corrected or adjusted by the registration roller pair 80 and is introduced between the photosensitive drum 2 and the transfer roller 8 through the third conveyance path L3. Since the non-printing surface of the paper T passes through the return conveyance path Lb, the non-printing surface faces the photosensitive drum 2, so that the toner image is transferred to the non-printing surface, and as a result, duplex printing is performed.
  Next, characteristic operations in the printer 1 of the present embodiment will be described with reference to FIGS. 11 and 12 are schematic longitudinal sectional views sequentially showing operations of the paper feed roller 66, the lift plate 603, the separating member 615, and the like when the paper T is fed from the paper feed roller 66. FIG.
  The characteristic operation of the printer 1 according to the present embodiment will be briefly described. As shown in FIGS. 12A and 12B, the separating member 615 has a leading end T1 in the transport direction D1 of the paper T so that the pair of registration rollers is aligned. When the sheet is sandwiched between the sheet feeding roller 66 and the separating member 615, the sheet T is separated from the sheet T. More specifically, the separating member 615 releases the reaction force in the direction D2 opposite to the conveyance direction D1 of the paper T generated on the paper T when the paper T is transferred from the paper supply roller 66 to the registration roller pair 80. And move away from the paper feed roller 66.
  Further, as shown in FIGS. 11C to 12B, the separating member 615 operates to move the lift plate 603 away from the paper supply roller 66 (operation to release the pressure of the lift plate 603 against the paper supply roller 66). ) In a direction away from the paper feed roller 66.
A characteristic operation in the printer 1 of the present embodiment will be described in detail. After the paper T is placed on the manual feed tray 65 and the lift plate 603 (see FIG. 11A), when an operation to start printing is performed, a predetermined signal is transmitted, as shown in FIG. The solenoid 611 is activated.
Note that, when the solenoid 611 is not in operation, the input gear 610 is positioned at the first toothed portion 607a of the toothless gear 607, and therefore the input gear 610 and the toothless gear 607 are not engaged with each other. Further, since the paper feed drive gear 602 is located at the second missing tooth portion 607b of the missing tooth gear 607, the paper feed drive gear 602 and the missing tooth gear 607 are not engaged with each other.
When the engagement between the locking claw 608a and the actuator 612 is released in a state where the missing gear 607 and the input gear 610 are not meshed and the missing gear 607 and the paper feed drive gear 602 are not meshed. The missing gear 607 is rotated by the biasing force. More specifically, when the solenoid 611 is activated, the tip 612 a of the actuator 612 is separated from the locking claw 608 a of the control cylinder 608. As a result, the rotating cam 609 starts rotating due to the contraction force of the second spring 614, and accordingly, the missing gear 607 starts rotating.
When the toothless gear 607 rotates to some extent by the contraction force of the second spring 614, the input gear 610 and the toothless gear 607 start to mesh. When the input gear 610 and the missing gear 607 mesh with each other, the missing gear 607 further rotates with a strong driving force (rotational force).
  As shown in FIG. 9 and FIG. 10, when the rotation of the rotating gear 609 starts when the toothless gear 607 that has started rotating and the input gear 610 start to rotate, the lift lever 604 is pushed up, and the lift plate 603 is lifted by the lift lever 604. Is pushed up, and the paper T is pressed against the paper feed roller 66 by the lift plate 603. Specifically, when the rotating cam 609 rotates with the rotation of the toothless gear 607, the second convex portion 604b of the lift lever 604 moves from the position of the bent peripheral surface 609b of the rotating cam 609 to the position of the arcuate peripheral surface 609a. Moving. Therefore, the lift lever 604 moves upward and pushes the push-down bracket 605 up by the first convex portion 604a. As a result, as shown in FIG. 11B, the lift plate 603 connected to the push-down bracket 605 moves upward. Accordingly, the paper T placed on the lift plate 603 is pressed against the peripheral surface of the paper feed roller 66 by the second receiving portion 603 a of the lift plate 603.
  Note that, as described above, the separating member 615 is urged in a direction approaching the sheet feeding roller 66 by the extension force of the third spring 618.
  In this state, as shown in FIG. 10, the toothless gear 607 and the paper feed drive gear 602 start to mesh and the paper feed roller 66 rotates, so that the paper T is fed into the housing (device main body) M. Is done. More specifically, the paper feed drive gear 602 located in the second toothless portion 607b of the toothless gear 607 starts to mesh with the toothless gear 607 and starts rotating. As a result, the paper feed drive shaft 601 and the paper feed roller 66 connected to the paper feed drive gear 602 also rotate. As shown in FIG. 11C, the paper T sandwiched between the paper feed roller 66, the lift plate 603, and the separating member 615 is fed to the registration roller pair 80 via the seventh transport path L7 and the like. .
As shown in FIGS. 11C and 12A, when the leading end T1 in the transport direction D1 of the paper T reaches the registration roller pair 80 and is nipped, the lift plate 603 is pushed up by the lift lever 604. Canceled. As a result, the lift plate 603 is pushed down by the push-down bracket 605, and the lift plate 603 moves away from the paper feed roller 66.
Then, as shown in FIG. 12B, after the lift plate 603 is separated from the paper feed roller 66 and the pressure of the lift plate 603 against the paper feed roller 66 is released, the engaging portion 603b and the engaged portion 615b are engaged. When the lift plate 603 moves in a direction away from the paper feed roller 66 in a state in which is engaged, the separating member 615 moves in a direction away from the paper feed roller 66.
  That is, the separating member 615 is formed between the sheet feeding roller 66 and the separating member 615 after the leading end T1 in the transport direction D1 of the sheet T comes into contact with the registration roller pair 80 and before the registration roller pair 80 is driven to rotate. The paper is separated from the paper T sandwiched therebetween, and the pressing of the lift plate 603 and the separating member 615 against the paper supply roller 66 is released. More specifically, the separating member 615 moves in a direction away from the paper supply roller 66 in conjunction with the operation of releasing the pressing of the lift plate 603 against the paper supply roller 66. As a result, the separation member 615 releases the reaction force in the direction D2 opposite to the conveyance direction D1 of the paper T generated on the paper T when the paper T is transferred from the paper supply roller 66 to the registration roller pair 80.
  Thereafter, as shown in FIG. 12C, when the paper T is discharged from the registration roller pair 80, the input gear 610 is driven to rotate, and the missing gear 607 that meshes with the input gear 610 includes the control cylinder 608 and Together with the rotating cam 609, the initial position shown in FIGS. 8A and 9A is returned. And the front-end | tip part 612a of the operation element 612 is again latched by the latching claw 608a of the control cylinder 608, and rotation of the missing gear 607, the control cylinder 608, and the rotation cam 609 stops. Thereafter, the above-described operation is repeated, and the paper feed by the manual paper feed unit 64 is repeated. In other words, the separating member 615 releases the press of the lift plate 603 and the separating member 615 against the sheet feeding roller 66, and after the sheet T is fed toward the registration roller pair 80, the next sheet T is fed to the sheet feeding roller 66. Press between.
According to the printer 1 of the present embodiment, the following effects are exhibited.
In the printer 1 of the present embodiment, the separating member 615 has a paper feed roller after the leading end T1 in the transport direction D1 of the paper T is in contact with the registration roller pair 80 and before the registration roller pair 80 is rotationally driven. The pressing of the lift plate 603 and the rolling member 615 against 66 is released. In particular, the separating member 615 releases the reaction force D2 opposite to the conveyance direction D1 (anti-conveyance direction) D2 generated on the paper T when the paper T is transferred from the paper supply roller 66 to the registration roller pair 80. Thus, the sheet moves in a direction away from the sheet feeding roller 66.
Therefore, when the paper T is transferred from the paper feed roller 66 to the registration roller pair 80, the paper feed drive shaft 601 that drives the paper feed roller 66 is not easily twisted. Accordingly, it is possible to suppress noise caused by the twisting of the paper feed drive shaft 601 that is the drive shaft of the paper feed roller 66 being released.
Further, tooth chipping (breakage) in various gears for driving the paper feed roller 66 can be suppressed.
  Further, the separation member 615 moves in a direction away from the paper supply roller 66 in conjunction with the operation of releasing the pressing of the lift plate 603 against the paper supply roller 66, so that the rear end portion T2 of the paper T is supplied with paper. It is possible to prevent the sheet feeding drive shaft 601 of the sheet feeding roller 66 from being twisted after the transition between the roller 66 and the lift plate 603 and between the sheet feeding roller 66 and the separating member 615.
  In particular, after the press of the lift plate 603 to the paper supply roller 66 is released, the lift plate 603 moves in a direction away from the paper supply roller 66 in a state where the engaging portion 603b and the engaged portion 615b are engaged. By doing so, the separating member 615 moves in a direction away from the sheet feeding roller 66, so that the operation of the lift plate 603 and the operation of the separating member 615 are more reliably linked.
As mentioned above, although preferred embodiment of this invention was described, this invention can be implemented with a various form, without being limited to embodiment mentioned above.
For example, in the above-described embodiment, the paper feed unit having the paper placement unit in the present invention is applied to the manual paper feed unit 64 having the manual feed tray 65. However, the present invention is not limited to this. A paper feed unit having a paper placement unit is applied to a paper feed unit that places paper on an inclined paper placement unit and feeds the paper into the housing so that the paper slides under its own weight. be able to.
The separating member 615 can be composed of a roller.
In the embodiment, the lift lever 604 is configured to push up the lift plate 603 indirectly via the push-down bracket 605. However, the present invention is not limited to this, and the lift lever 604 is not limited to the push-down bracket 605. The lift plate 603 may be directly pushed up.
The type of the image forming apparatus of the present invention is not particularly limited, and may be a copier, a printer, a facsimile, or a complex machine thereof.
The above embodiment is an image forming apparatus that includes an image forming unit that forms an image on a sheet fed from a sheet feeding roller inside a housing. However, the present invention is not limited to this, and the present invention is not limited to this. The present invention can be applied to a paper transport device that does not include a section. Further, the present invention can be applied to a paper transport mechanism that constitutes a part of a paper transport device.
3 is a left side view for explaining the arrangement of each component in the printer. FIG. FIG. 6 is an exploded perspective view of the manual sheet feeder 64 viewed from obliquely above on the right side of the apparatus main body M. FIG. 6 is an exploded perspective view of the manual sheet feeder 64 viewed from an obliquely upper side on the left side surface of the apparatus main body M. FIG. 6 is a longitudinal sectional view showing a paper feed roller 66, a lift plate 603, a separating member 615, and the like. FIG. 6 is an exploded perspective view of the missing gear 607 and the like viewed from obliquely above on the left side of the apparatus main body M. 4 is an exploded perspective view of the control cylinder 608, the actuator 612, and the like viewed from the left side of the apparatus main body M. FIG. FIG. 4 is an exploded perspective view of a rotating cam 609, a missing tooth gear 607, and the like when viewed from obliquely above on the right side surface of the apparatus main body M. It is a decomposition | disassembly left view which shows operation | movement of the control cylinder 608, the operation element 612, etc. one by one. It is a decomposition | disassembly right view which shows operation | movement of the rotation cam 609, the lift lever 604, etc. one by one. It is a decomposition | disassembly right view which shows operation | movement of the rotation cam 609, the lift lever 604, etc. one by one. FIG. 6 is a schematic vertical cross-sectional view sequentially showing operations of a paper feed roller 66, a lift plate 603, a separating member 615, and the like when paper T is fed from a paper feed roller 66. FIG. 6 is a schematic vertical cross-sectional view sequentially showing operations of a paper feed roller 66, a lift plate 603, a separating member 615, and the like when paper T is fed from a paper feed roller 66.
Explanation of symbols
  DESCRIPTION OF SYMBOLS 1 ... Printer (paper conveyance apparatus, image forming apparatus, paper conveyance mechanism), 64 ... Tray paper feeding part (paper feeding part), 65 ... Manual feed tray (paper placing part), 66 ... Paper feeding roller ( Paper feed roller), 80... Registration roller pair, 601... Paper feed drive shaft, 602... Paper feed drive gear, 603... Lift plate (lifting member), 604. ... depressing bracket, 606 ... camshaft, 607 ... missing tooth gear, 607a ... first tooth missing part, 607b ... second missing tooth part, 608 ... control cylinder, 608a ... locking claw, 609 ... ... Rotating cam, 610 ... Input gear, 611 ... Solenoid (actuator rotating part), 612 ... Operator, 615 ... Spring member, 615a ... Receiving part, D1 ... Conveying direction, D2 ... Conveying The direction opposite to the direction, M ... device body (housing), 1 ...... paper discharge stacking unit, T ...... paper, T1 ...... tip

Claims (9)

  1. A housing,
    A paper placement section on which paper is placed; a paper feed roller that feeds the paper placed on the paper placement section into the housing; and a paper feed roller from the paper placement section to the paper feed roller An elevating member that presses the paper against the paper feed roller by moving up and down, and a paper stack that is arranged so as to press the paper between the paper feed roller A sheet feeding unit having a member,
    A registration roller that is arranged inside the housing and that is driven to rotate and sends the paper to the downstream side in the transport direction after the leading edge of the paper fed from the paper feed roller in a stopped state is once contacted With a pair,
    The webbing member is pressed by the lifting member and the webbing member against the paper feed roller after the leading end in the paper transport direction is in contact with the registration roller pair and before the registration roller pair is rotationally driven. A paper transport device to release the.
  2.   The separating member releases the reaction force from the sheet feeding roller so as to release a reaction force in a direction opposite to the sheet conveyance direction when the sheet is transferred from the sheet feeding roller to the registration roller pair. The sheet conveying apparatus according to claim 1, wherein the sheet conveying apparatus moves in a separating direction.
  3.   3. The sheet conveying device according to claim 1, wherein the separation member moves in a direction away from the sheet feeding roller in conjunction with an operation of releasing the pressing of the lifting member against the sheet feeding roller.
  4. The elevating member has an engaging portion,
    The winding member has an engaged portion that engages with the engaging portion when the elevating member moves in a direction away from the paper feed roller,
    After the pressing of the elevating member against the paper feed roller is released, the elevating member moves in a direction away from the paper feed roller in a state where the engaging portion and the engaged portion are engaged. The sheet conveying device according to claim 3, wherein the separating member moves in a direction away from the sheet feeding roller.
  5.   5. The sheet conveying device according to claim 1, wherein the sheet feeding roller is connected to a sheet feeding driving shaft mainly composed of a resin member, and rotates when the sheet feeding driving shaft is driven.
  6. Input gear,
    A paper feed drive gear coupled to the paper feed roller;
    A toothless gear that selectively meshes with the input gear and the paper feed drive gear,
    A push-up member that pushes up the lifting member directly or indirectly;
    A rotating cam that pushes up the push-up member according to rotation and is urged in the rotation direction by an urging force, and rotates the toothless gear by the urging force;
    A control cylinder that rotates according to the rotation of the toothless gear and has a locking claw;
    An actuator engaged with the locking claw;
    An actuator rotating part for rotating the operating element, and
    The control cylinder does not rotate in a state where the operating element is engaged with the locking claw,
    When the engagement between the locking claw and the actuator is released in a state where the toothless gear and the input gear are not engaged with each other and the toothless gear and the paper feeding drive gear are not engaged with each other. , The toothless gear is rotated by the biasing force,
    When the partial gear and the input gear start to mesh with each other and the rotating cam rotates, the push-up member is pushed up, the lift member is pushed up by the push-up member, and the paper is fed by the lift member to the paper feed roller. 6. The sheet is fed into the housing by rotating the sheet feeding roller when the toothless gear and the sheet feeding drive gear start to mesh with each other. The paper conveying device according to claim 1.
  7.   The sheet-rolling member releases the next sheet from the sheet-feeding roller after the lifting member and the sheet-rolling member are released from the sheet-feeding roller and the sheet is fed toward the registration roller pair. The paper conveying device according to claim 1, wherein the paper conveying device is pressed between the paper conveying devices.
  8.   The image forming apparatus according to claim 1, further comprising an image forming unit that forms an image on the paper fed from the paper feed roller in the housing of the paper transport device according to claim 1.
  9. A paper placement section on which paper is placed, a paper feed roller placed on the paper placement section, and the paper feed by feeding up and down from the paper placement section toward the paper feed roller An elevating member that presses against the rollers, a sheeting member that presses the sheet between the sheet feeding rollers, and a sheet member that winds the bundle of sheets one by one, and is fed from the sheet feeding roller in a stopped state. A pair of registration rollers that, after the leading end of the paper that has been paper contacted once, rotates and sends the paper downstream in the transport direction,
    The webbing member is pressed by the lifting member and the webbing member against the paper feed roller after the leading end in the paper transport direction is in contact with the registration roller pair and before the registration roller pair is rotationally driven. A paper transport mechanism to release the.
JP2008088531A 2008-03-28 2008-03-28 Image forming device Pending JP2009242025A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2008088531A JP2009242025A (en) 2008-03-28 2008-03-28 Image forming device

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2012106853A (en) * 2010-11-19 2012-06-07 Kyocera Mita Corp Sheet material feeder and image forming device
CN108656637A (en) * 2018-03-28 2018-10-16 江苏南江智能装备股份有限公司 A kind of portable molding machine of guiding chip and portable forming method

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH04350033A (en) * 1991-03-19 1992-12-04 Canon Inc Paper feeder and image forming device used thereof
JPH0616269A (en) * 1992-06-30 1994-01-25 Canon Inc Paper feeding device
JPH08208059A (en) * 1995-02-01 1996-08-13 Canon Inc Paper feeding device and image forming device
JPH11343037A (en) * 1998-06-01 1999-12-14 Mita Ind Co Ltd Paper conveying device
JP2005154076A (en) * 2003-11-26 2005-06-16 Fuji Xerox Co Ltd Sheet material feeder

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH04350033A (en) * 1991-03-19 1992-12-04 Canon Inc Paper feeder and image forming device used thereof
JPH0616269A (en) * 1992-06-30 1994-01-25 Canon Inc Paper feeding device
JPH08208059A (en) * 1995-02-01 1996-08-13 Canon Inc Paper feeding device and image forming device
JPH11343037A (en) * 1998-06-01 1999-12-14 Mita Ind Co Ltd Paper conveying device
JP2005154076A (en) * 2003-11-26 2005-06-16 Fuji Xerox Co Ltd Sheet material feeder

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2012106853A (en) * 2010-11-19 2012-06-07 Kyocera Mita Corp Sheet material feeder and image forming device
CN108656637A (en) * 2018-03-28 2018-10-16 江苏南江智能装备股份有限公司 A kind of portable molding machine of guiding chip and portable forming method

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