JP2011121708A - Medium straightening device and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a medium straightening device for securing separative performance between a first holder and a second holder with elastic force, and to provide an image forming device. <P>SOLUTION: The medium straightening device includes a first peripherally moving body whose peripheral face peripherally moves, a second peripherally moving body having a space from the first peripherally moving body where a recording medium on the surface of which an image is formed passes, a first holder holding the first peripherally moving body, a second holder holding the second peripherally moving body and joined to the first holder in a freely unjoined manner, an elastic member for giving elastic force to the first holder and the second holder and for separating the first holder and the second holder from each other with the elastic force when the first holder and the second holder are unjoined from each other, and a mounting part on which the elastic member is mounted for giving the elastic force thereto, from which the elastic member is demountable, and which has a plurality of mounting positions different in elastic force. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a medium correction apparatus and an image forming apparatus.

  2. Description of the Related Art Conventionally, as a curl correction device that corrects curl generated on paper, in order to facilitate the removal of paper jammed in the paper transport path in the device, the device is connected to the upper part of the device with the paper transport path as a boundary. 2. Description of the Related Art An apparatus having a structure in which an upper end portion of an apparatus and an end portion of an apparatus lower portion are connected to each other in an indivisible manner and the opposite end portions are releasably coupled is known. In the curl straightening device having such a structure, a spring material is provided at a connection point where the upper part of the device and the lower part of the device are connected so as not to be separated, and the connection of the connection points for releasably connecting the upper part of the device and the lower part of the device is released. A device is also known in which the upper part of the device is lifted to some extent by the urging force of the spring material provided at the connection location (for example, Patent Document 1).

JP 2009-249168 A

  An object of the present invention is to provide a medium correction device and an image forming apparatus that can ensure separation between a first holding body and a second holding body by elastic force.

The medium straightening device according to claim 1 comprises:
A first rotating body whose circumferential surface moves around,
The peripheral surface has a peripheral surface that is softer than the peripheral surface of the first peripheral member, and the peripheral surface is pressed against the peripheral surface of the first peripheral member, so that the peripheral member moves around the peripheral surface of the first peripheral member. A second rotating body through which a recording medium on which an image is formed passes between the moving first moving body,
A first holding body holding the first peripheral body;
A second holding body that holds the second peripheral body and is releasably coupled to the first holding body;
An elastic force is applied to the first holding body and the second holding body. When the coupling between the first holding body and the second holding body is released, the first holding body and the second holding body are moved together. An elastic member to be separated by elastic force;
The elastic member is attached and the elastic force acts, and the elastic member is removable, and has a plurality of attachment portions with different elastic force magnitudes,
It is provided with.

A medium correction apparatus according to claim 2 is provided.
The elastic member separates the first holding body and the second holding body from each other vertically;
Of the first holding body and the second holding body, the holding body that separates upward is characterized in that at least a part of the members is a member that can be replaced with another member having a different weight.

The medium correction device according to claim 3 is:
The elastic member is a toggle spring having at least one end attached to the attachment portion,
The mounting portion has a plurality of mounting positions where the angles of the toggle springs are different from each other.

An image forming apparatus according to claim 4
An image forming unit that forms an image on the surface of the recording medium;
A first rotating body whose circumferential surface moves around,
The peripheral surface has a peripheral surface that is softer than the peripheral surface of the first peripheral member, and the peripheral surface is pressed against the peripheral surface of the first peripheral member, so that the peripheral member moves around the peripheral surface of the first peripheral member. A second rotating body through which a recording medium on which an image is formed passes between the moving first moving body,
A first holding body holding the first peripheral body;
A second holding body that holds the second peripheral body and is releasably coupled to the first holding body;
An elastic force is applied to the first holding body and the second holding body. When the coupling between the first holding body and the second holding body is released, the first holding body and the second holding body are moved together. An elastic member to be separated by elastic force;
The elastic member is attached and the elastic force acts, and the elastic member is removable, and has a plurality of attachment portions with different elastic force magnitudes,
It is provided with.

  According to the medium straightening device of the first aspect, it is possible to ensure the separation between the first holding body and the second holding body by the elastic force.

  According to the medium straightening device of the second aspect, even if the weight of the upper holding body changes, the separability by the elastic force can be ensured.

  According to the medium straightening device of the third aspect, the separability can be ensured with a simple structure.

  According to the image forming apparatus of the fourth aspect, it is possible to ensure the separation between the first holding body and the second holding body by the elastic force.

1 is a schematic configuration diagram of an image forming apparatus. It is a perspective view from the side of a decurler device. It is a figure which shows the motive power system of a decurler apparatus. It is an external appearance perspective view from diagonally upward of a decurler apparatus. It is a schematic block diagram of a roll decurler part and a belt decurler part. It is a graph which shows the relationship between the amount of biting in a roll decurler part, and a paper conveyance speed. FIG. 6 is a graph showing the relationship between the amount of biting in the belt decurler section and the sheet conveyance speed. FIG. 6 summarizes the contents represented by the graph in a table. FIG. 7 summarizes the contents represented by the graph in a table. It is a figure which shows the relationship between the amount of biting in each of a roll decurler part and a belt decurler part, and a shaft speed setting value. FIG. 2 is a schematic configuration diagram around a fixing device. It is an external appearance perspective view of the decurler apparatus pulled out from the main body housing. It is an external appearance perspective view of the locking mechanism for locking an upper part with respect to the lower part of a decurler apparatus. FIG. 14 is a perspective view from the side of the locking mechanism shown in FIG. 13. It is a figure which shows the state in which the operation lever is not operated. It is a figure which shows the state which the operation lever was lifted slightly. It is a figure which shows the state which the operation lever was further lifted rather than being shown by FIG. It is a figure which shows the state which released the operation lever, after the operation lever lifted. It is a figure which shows a mode that the decurler apparatus was accommodated in the main body housing | casing in the locked state. It is an external appearance perspective view of the decurler apparatus with the upper part open | released with respect to the lower part. It is a figure which shows the assembly | attachment method of a lower discharge guide. It is a figure which shows the connection part of the upper part and lower part of a decurler apparatus. It is a figure which shows the cover of the harness which connects an upper part and a lower part. It is a schematic diagram of a roll decurler part. It is a figure which shows the state which looked at the weight attached to the 1st rotating shaft in the direction of arrow Z shown by part (d) of FIG. FIG. 25 is a diagram showing another aspect of the embodiment shown in FIG. 24. It is a side view of the decurler apparatus seen from the cooler side. FIG. 28 is an enlarged view of the first support member shown in FIG. 27. It is an external appearance perspective view of the correction | amendment roll currently supported by the 1st supporting member. It is a figure which shows the replacement | exchange method of a correction | amendment roll.

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

  FIG. 1 is a schematic configuration diagram of an image forming apparatus.

  An image forming apparatus 100 shown in FIG. 1 forms an electrostatic latent image on the surface of a photosensitive member, develops the electrostatic latent image with toner, forms a toner image, and finally transfers the toner image on a sheet. The apparatus forms an image composed of a fixed toner image on the paper by transferring and fixing to the paper. The image forming apparatus 100 is an apparatus that supports not only paper, that is, a paper recording medium, but also a resin recording medium typified by an OHP sheet. However, in the following description, paper is used unless otherwise specified. It is assumed that the recording medium is described as a representative.

  The image forming apparatus 100 is a tandem color printer in which six image forming units 10A, 10B, 10C, 10D, 10E, and 10F that are responsible for image formation of different colors are arranged in parallel. In the full color mode, a color image composed of a plurality of color toner images can be printed. For example, among the six image forming units 10A to 10F, four image forming units 10C, 10D, 10E, and 10F are respectively yellow (Y), magenta (M), cyan (C), and black (K). Corresponding to each color, the remaining two image forming units 10A and 10B correspond to special colors other than YMCK. The spot colors include, for example, colors that cannot be accurately expressed by the above YMCK composition, such as colors representing a corporate color of a specific company, pastel colors, and glossy transparent colors. The image forming apparatus 100 includes six toner cartridges 18A, 18B, 18C, 18D, 18E, and 18F that store toners of colors corresponding to the image forming units 10A to 10F, respectively. Further, the image forming apparatus 100 is provided with a duplex printing mode in addition to the default simplex printing mode. The image forming apparatus 100 is an embodiment of the image forming apparatus of the present invention.

  Since the six image forming units 10A to 10F have the same configuration, the image forming unit 10F corresponding to black will be described below as a representative example.

  The image forming unit 10F includes a photoconductor 110, a charger 120 that charges the surface of the photoconductor 110, an exposure device 130 that irradiates the photoconductor 110 with exposure light based on an image signal supplied from the outside, and a surface of the photoconductor 110. And a primary transfer unit 150 that transfers the toner image onto the intermediate transfer belt. The photoconductor 110 has a cylindrical surface, and rotates in the direction of arrow a around the axis of the cylinder.

  Further, the image forming apparatus 100 includes an intermediate transfer belt 200 to which a toner image is transferred from the photoconductor 110 of the image forming units 10A to 10F, and a secondary transfer device 300 for transferring the toner image from the intermediate transfer belt 200 to a sheet. A fixing device 400 that fixes toner on a sheet, a decurler device 1 that corrects curling of the sheet, and a sheet conveying unit 600 that conveys the sheet are provided. Further, the image forming apparatus 100 includes sheet containers 710 and 720 that store sheets, a deburring device 800 that removes burrs before forming an image, an attitude correcting unit 730 that corrects the attitude of the sheet, and a toner. A cooler 740 that cools the sheet after fixing, a discharge sheet storage unit 690 that receives a sheet on which image formation by the image forming apparatus 100 has been completed, and a main body control unit 101 that controls each part of the image forming apparatus 100 are provided. ing. The image forming apparatus 100 includes a transport path R1 where an image is formed on the surface of the paper being transported, and a front / back reversal path R2 where a paper with a toner image fixed on one side is reversed.

  The intermediate transfer belt 200 is an endless belt-like member supported by belt support rolls 210, 220, and 230, and circulates and moves in the direction of arrow b passing through the image forming units 10A to 10F and the secondary transfer device 300 in this order. To do.

  The paper transport unit 600 includes take-out rolls 610 and 620 that take out paper from the paper containers 710 and 720, and a registration roll that sends the paper to the secondary transfer device 300 in accordance with the timing at which the secondary transfer device 300 transfers the toner image. 640, a suction conveyance device 650 that conveys the sheet from the secondary transfer device 300 to the fixing device 400 while adsorbing the sheet to the outer peripheral surface of the conveyance belt 651, a discharge roll 660 that discharges the sheet to the outside of the image forming apparatus 100, and a conveyance And a transport roll 680 that transports the paper, which is disposed along the path R1 and the front / back reversing path R2.

  The paper transport unit 600 transports paper from the paper containers 710 and 720 to the deburring device 800, the posture correction unit 730, the secondary transfer device 300, the fixing device 400, the cooler 740, and the decurler device 1 in order. Convey along. When double-sided printing is performed, the paper transport unit 600 transports the paper along the front / back reversing path R2 that branches from the transport path R1 and returns to the transport path R1. As a result, the paper on which the toner image is fixed on one side while passing through the transport path R1, the front and back sides are reversed while passing through the front / back reversing path R2, and the paper whose front and back sides are reversed returns to the transport path R1. After passing through the deburring device 800 and the posture correcting unit 730 again, the secondary transfer device 300 transfers the toner image to the back surface, that is, the surface where the toner image has not been transferred.

  The basic operation of the image forming apparatus 100 shown in FIG. 1 will be described. For example, a case where a black (K) image is formed by the corresponding image forming unit 10F as the monochromatic mode will be described. The photoconductor 110 is driven to rotate in the direction of arrow a, and the surface of the photoconductor 110 is charged by the charger 120. Is granted. The exposure device 130 forms an electrostatic latent image on the surface of the photoconductor 110 by irradiating the photoconductor 110 with exposure light based on an image signal supplied from the outside. More specifically, the exposure device 130 forms an electrostatic latent image on the surface of the photoconductor 110 by irradiating exposure light according to data corresponding to black in the image signal. The developing device 140 forms a toner image on the surface of the photoconductor 110 by developing the electrostatic latent image with black toner. The toner is supplied from the toner cartridge 18F to the developing device 140 of the image forming unit 10F. The photoconductor 110 receives the formation of the toner image and holds the toner image. The toner image formed on the surface of the photoreceptor 110 is transferred to the intermediate transfer belt 200 by the primary transfer device 150.

  On the other hand, the paper in the paper containers 710 and 720 is taken out by the take-out rolls 610 and 620, and is transported along the transport path R1 in the direction of the arrow c by the transport roll 680 and the registration roll 640, toward the secondary transfer device 300. . The paper heading to the secondary transfer device 300 is deburred on the edge of the paper by a deburring device 800 disposed in the middle of the transport path R1. The posture and position of the paper that has been deburred by the deburring device 800 are corrected by the posture correction unit 730.

  The secondary transfer device 300 transfers the toner image on the intermediate transfer belt 200 to the paper by generating a potential difference for transfer between the intermediate transfer belt 200 and the paper. The sheet on which the toner image has been transferred is conveyed in the direction of arrow d by the conveyance belt 651, and the toner image is fixed on the sheet surface by the fixing device 400. In this way, an image is formed on the paper. The fixing device 400 has a heating belt to increase the heat capacity. The sheet with the image formed on the surface is cooled by the cooler 740, the curl is corrected by the decurler device 1, discharged by the discharge roll 660, and stacked on the discharge sheet storage unit 690.

  In the full color mode, the five image forming units 10A to 10E corresponding to colors other than black operate in the same manner as the image forming unit 10F corresponding to black, and a toner image of the corresponding color is formed. In the image forming units 10 </ b> A to 10 </ b> F, the image formation and transfer timing are adjusted so that the toner images formed on the surface of each photoconductor are superimposed when transferred onto the intermediate transfer belt 200.

  In the double-sided printing mode, the paper transport unit 600 transports the paper that has been transported along the transport path R1 and has fixed the image on one side and corrected the curl along the front-back reversing path R2, and the paper. Then, the image is fixed to the other surface and the curl correction is performed again while being conveyed along the conveyance path R1. The above is the outline of the image forming operation in the image forming apparatus 100.

  Next, the decurler device 1 will be described.

  FIG. 2 is a perspective view from the side of the decurler device.

  The decurler device 1 shown in FIG. 2 includes a receiving chute 2 that receives a sheet that has passed through a cooler 740, a roll decurler unit 3 that corrects curling of the sheet, and a belt decurler unit 4 that is disposed downstream of the roll decurler unit 3 in the sheet conveying direction. , A transport roll unit 5 that transports the paper with the curl corrected, and a discharge chute unit 6 that discharges the paper from the decurler device 1.

  The roll decurler unit 3 is disposed above the conveyance drive shaft 31 and conveys the sheet fed through the receiving chute 2 by itself and rotationally conveys the sheet between the conveyance drive shaft 31. A straightening roll 32 that sandwiches and corrects the curl of paper, a first holding member 33 that holds both ends of the central axis of the straightening roll 32 so that the straightening roll 32 is rotatable, and one end 331 of the first holding member 33. A first eccentric cam 34 that is in contact with the first rotating shaft 35 and a first rotating shaft 35 to which the first eccentric cam 34 is fixed and connected to the rotating shaft of a stepping motor provided on the main body side of the image forming apparatus 100. is doing. The first holding member 33 is allowed to change its posture within a predetermined range. The decurler device 1 is an embodiment of a medium correction device.

  The roll decurler unit 3 supports the first holding member 33 while allowing the weight 36 attached to the first rotating shaft 35 and the change in posture of the first holding member 33 within a predetermined range. And a first support member 37. In the roll decurler unit 3, the first holding member 33, the first eccentric cam 34, and the first support member 37 are provided in pairs.

  The correction roll 32 is a roll whose surface is softer than the conveyance drive shaft 31 and rotates following the conveyance drive shaft 31. As the posture of the first holding member 33 changes, the amount of biting of the transport drive shaft 31 with respect to the correction roll 32 changes.

  The first holding member 33 is a resin molded member having a thickness of about 5 mm. The first holding member 33 is provided along one end of the contact portion 331 that contacts the first eccentric cam 24 and the other end along the direction in which the correction roll 32 extends. Through-holes 332. Moreover, the 1st holding member 33 is hold | maintaining so that the correction | amendment roll 32 can rotate freely at both ends of the center axis | shaft 321 of the correction | amendment roll 32 in the center part.

  The first rotating shaft 35 is supported by each housing portion so that the first rotating shaft 35 can rotate freely in each of the front and back housing portions shown in FIG. 2 of the upper housing 11. The first eccentric cam 34 is eccentrically fixed at a position corresponding to the contact portion 331 of the first holding member 33 inside both portions supported by the housing portion. Further, the first rotation shaft 35 is a stepping provided on the main body side of the image forming apparatus 100 via a coupler fixed outside the housing portion on the back side of the upper housing 11 shown in FIG. It is connected to the motor. The weight 36 attached to the first rotating shaft 35 will be described later.

  As will be described in detail later, the first support member 37 is a metal member having a through shaft 371 passing through the through hole 332 of the first holding member 33 at one end, and the other end fixed to the upper housing 11 with a screw 38. Has been. The distal end of the through shaft 371 penetrating through the through hole 332 is inserted into holes provided in the front and back side housing parts shown in FIG.

  When the stepping motor provided on the main body side is driven by the designated number of steps, the first rotating shaft 35 connected to the stepping motor rotates by the rotation angle corresponding to the designated number of steps. Accordingly, the posture of the first eccentric cam 24 that is eccentrically fixed to the first rotation shaft 35 is changed.

  Since the contact portion 331 of the first holding member 33 is in contact with the first eccentric cam 34, the first holding member 33 penetrates the through hole 332 due to a change in the posture of the first eccentric cam 34. It rotates around the penetrating shaft 371. The amount of biting of the transport drive shaft 31 with respect to the correction roll 32 held by the first holding member 33 changes as the posture of the first holding member 33 changes around the through shaft 371. When the amount of biting of the conveyance drive shaft 31 with respect to the correction roll 32 changes, the correction force for the paper passing between the correction roll 32 and the conveyance drive shaft 31 also changes.

  The roll decurler unit 3 is in charge of correcting the paper with the curl that jumps up at both ends in terms of the posture of the paper being transported along the transport path R1, and passes between the straightening roll 32 and the transport drive shaft 31. The degree of correction of the curl of the sheet to be increased becomes stronger as the amount of biting of the conveyance drive shaft 31 with respect to the correction roll 32 is increased, and is reduced as the amount is reduced. This roll decurler part is an example of a correction part, and the conveyance drive shaft 31 and the correction roll 32 are examples of a rod-shaped rotating body, respectively. Moreover, the correction | amendment roll 32 is also an example of a surrounding body.

  The belt decurler unit 4 adjusts the pressing of the sheet against the belt unit 41 by the belt unit 41 that conveys the sheet, the pressing member 42 that presses the sheet against the belt unit 41, the sheet conveying guide 45 that guides the conveyance of the sheet, and the pressing member 42. The second eccentric cam 46, the second eccentric cam 46 is fixed, and the second rotary shaft 43 is connected to the rotary shaft of a stepping motor provided on the main body side of the image forming apparatus 100. , And an intermediate member 44 that contacts both the second eccentric cam 46 and the pressing member 42.

  The belt unit 41 includes a rotation drive roll 411 that rotates, a freely suspended suspension roll 412, an endless belt 413 wound around the rotation drive roll 411 and the suspension roll 412, and a tension that applies tension to the endless belt 413. It is comprised with the roll 414. The rotation drive roll 411 has a central axis 4111 at the center, and the central axis 4111 is a central axis in each of the upper and lower casing portions of the upper casing 11 shown in FIG. 4111 is rotatably supported by each casing portion. In addition, a coupler is attached to the central axis 4111 at a location farther than the location supported by the housing portion on the back side, and the central axis 4111 is connected to the image forming apparatus via the coupler. 100 is connected to a rotary motor provided on the main body side.

  Similarly to the first rotation shaft 35, the second rotation shaft 43 is rotatably supported by the front and rear housing portions of the upper housing 11 shown in FIG. The second eccentric cam 46 is fixed slightly inside the portion supported by the housing portion, and the image forming apparatus 100 is connected via a coupler fixed outside the housing portion on the back side. It is connected to a stepping motor provided on the main body side.

  The intermediate member 44 includes a disc member 441 that is in contact with the second eccentric cam 46 and a first moving shaft 442 that passes through the center of the disc member 441 and is fixed to both ends. It is configured. Since the second eccentric cam 46 and the disk member 441 are in contact with each other, the first moving shaft 442 moves up and down within a predetermined range in accordance with a change in the posture of the second eccentric cam 46.

  The pressing member 42 includes a second moving shaft 422 whose both end portions are in contact with the disk member 441 and a pressing roll 421 that is in contact with the endless belt 413 with the second moving shaft 422 as a central axis. Since the disk member 441 of the intermediate member 44 and the second moving shaft 422 are in contact with each other, the pressing member 42 moves up and down within a predetermined range as the intermediate member 44 moves up and down.

  Both ends of the sheet transport guide 45 are connected to both ends of the second moving shaft 422, and the posture of the sheet transport guide 45 changes as the second moving shaft 422 moves up and down. The paper transport guide 45 changes its posture according to the position of the second moving shaft 422, so that smooth paper transport is ensured.

  When the stepping motor provided on the main body side is driven by the designated number of steps, the second rotating shaft 43 connected to the stepping motor rotates by the rotation angle corresponding to the designated number of steps. As a result, the posture of the second eccentric cam 46 that is eccentrically fixed to the second rotating shaft 43 changes.

  In the intermediate member 44, the first moving shaft 442 moves up and down according to the posture of the second eccentric cam 46. As the first moving shaft 442 moves up and down, the second moving shaft 422 also moves up and down, and the amount of biting of the pressing roll 421 with respect to the endless belt 413 changes. Thereby, when the amount of biting of the second moving shaft 422 with respect to the endless belt 413 changes, the correction force for the paper passing between the endless belt 413 and the second moving shaft 422 also changes.

  The belt decurler unit 4 is in charge of correcting the sheet with the curl with both ends facing downward in the posture of the sheet being conveyed on the conveyance path R1, and passes between the endless belt 413 and the pressing roll 421. The degree of correction of the curl of the sheet to be increased becomes stronger as the amount of the press roll 421 biting into the endless belt 413 is increased, and is reduced as the amount is reduced. The belt decurler unit 4 is an example of a correction unit. The belt unit 41 is an example of a rotating body, an example of a rotating body having a plurality of peripheral surfaces, and further an example of a rotating body having a belt member. Each endless belt 413 is an example of a band member. Also, each outer peripheral surface of each endless belt 413 is an example of a peripheral surface that moves around.

  The transport unit 5 includes an upper rotary roll 51 and a lower rotary roll 52, and feeds the paper to the discharge unit 6 by rotating with the paper that has been corrected for curling in between.

  The discharge unit 6 includes an upper chute 61 and a lower chute 62, and discharges the sheet fed from the transport unit 5 from the decurler device 1 to the outside. The upper chute 61 is attached to the upper housing 11, and the lower chute 62 is attached to the lower housing 12.

  As will be described in detail later, the decurler device 1 is divided into an upper portion and a lower portion with a sheet conveyance path as a boundary, and an upper end portion so that the upper portion can be freely opened and closed with respect to the lower portion. Are connected to the lower end.

  FIG. 3 is a diagram illustrating a power system of the decurler device.

  In FIG. 3, a main drive system L1 using a main motor M1 provided on the main body side of the image forming apparatus 100 as a drive source and a local motor M2 provided in the decurler device 1 are used as drive sources. Two systems with a local drive system L2 are shown.

  The main drive system L1 includes the main motor M1, the transmission gear group G11, and the central shaft 4111 of the rotation drive roll 411 of the belt unit 41 shown in the upper part of FIG.

  The local drive system L2 is supplied to the first local drive system L21 that transmits the rotational drive force of the local motor M2 shown in the lower part of FIG. 3 to the transport drive shaft 31 of the roll decurler unit 3, and the lower rotary roll 52 of the discharge unit 5. It consists of a second local drive system L22 for transmission.

  The first local drive system L21 includes a local motor M2, a transmission gear group G21, and a transport drive shaft 31, and the second local drive system L22 includes a local motor M2, a transmission gear group G22, and a lower rotary roll 52. Has been. Each of the local motor M2 and the main motor M1 is an example of a drive source.

  3 shows a first stepping motor SM1 provided on the main body side of the image forming apparatus 100 that supplies a rotational driving force to the first rotating shaft 35 of the roll decurler unit 3, and a second rotation of the belt decurler unit 4. A second stepping motor SM2 provided on the main body side of the image forming apparatus 100 that supplies a rotational driving force to the shaft is shown.

  FIG. 4 is an external perspective view of the decurler device from obliquely above.

  4 also shows the opposite side of the decurler device 1 from the side shown in FIG.

  4, on the opposite side of the side shown in FIG. 2, in order from the top, the edge of the first rotating shaft 35 of the roll decurler unit 3, the edge of the second rotating shaft 43 of the belt decurler unit 4, and The screw-shaped coupler 13 attached to the edge of the central shaft 4111 of the rotation drive roll 411 of the belt decurler unit 4 is shown.

  As described above, the decurler device 1 can be pulled out from the main body housing of the image forming apparatus 100 in order to remove paper when a jam occurs or to replace consumable parts. Therefore, in the decurler device 1, the first rotating shaft 35 to which the rotational driving force is transmitted from the main motor M1, the first stepping motor SM1, the second stepping motor SM2, and the like provided on the main body side of the image forming apparatus 100, A screw-like coupler 13 is attached to the second rotating shaft 43 and the central shaft 4111, and a coupler that meshes with the coupler 13 is attached to the rotating shaft of each motor on the main body side and the shaft of the transmission gear. . By doing so, it is possible to transmit the driving force from the driving source provided on the main body side to the decurler device 1 that can be pulled out from the main body casing.

  Here, in the decurler device 1, the drive source of the transport drive shaft 31 of the roll decurler unit 3 and the drive source of the rotational drive roll 411 of the belt decurler unit 4 are separated. In the following, the reason why the drive source is set as a separate system in the roll decurler unit 3 and the belt decurler unit 4 will be described.

  FIG. 5 is a schematic configuration diagram of the roll decurler unit and the belt decurler unit.

  FIG. 5 shows a state in which the correction roll 32 of the roll decurler unit 3 and the pressing member 42 of the belt decurler unit 4 are respectively movable in the arrow direction. In FIG. 5, a state of correcting the curl by the roll decurler unit 3, that is, a state in which correction that softens the curl is performed on a paper sheet with curl that jumps up at both ends is shown by a solid line. Further, the state of correcting curling wrinkles by the belt decurler unit 4, that is, the state in which correction for softening the wrinkles is performed on paper with curled wrinkles with both ends facing downward is shown by dotted lines.

  FIG. 6 is a graph showing the relationship between the amount of biting in the roll decurler unit and the sheet conveyance speed.

  In FIG. 6, the influence on the sheet conveyance speed when the amount of biting of the conveyance drive shaft 31 into the correction roll 32 is changed, the rotational speed of the conveyance drive shaft 31 of the roll decurler unit 3 is 266.5 mm / sec, 310. The cases are set to 0.0 mm / sec, 400.0 mm / sec, 445.0 mm / sec, and 500.0 mm / sec, respectively.

  From FIG. 6, it can be confirmed that the sheet conveyance speed increases linearly as the amount of biting increases regardless of the rotation speed of the conveyance drive shaft 31. Even when the shaft rotation speed is the same, the paper conveyance speed is faster when the amount of biting is large than when the amount of biting is small. The gripping force of the conveyance driving shaft 31 with respect to the paper increases as the amount of biting increases. On the other hand, it is considered that the conveyance drive shaft 31 does not slip.

  On the other hand, FIG. 7 is a graph showing the relationship between the amount of biting in the belt decurler section and the sheet conveyance speed.

  In FIG. 7, the influence on the sheet conveyance speed when the amount of biting of the pressing roll 421 into the endless belt 413 changes the rotational speed of the rotational drive roll 411 of the belt unit 41 to 266.5 mm / sec, 310. The cases where 0 mm / sec, 400.0 mm / sec, 450.0 mm / sec, 480.0 mm / sec, and 510.0 mm / sec are set are respectively shown.

  From FIG. 7, it can be confirmed that the sheet conveyance speed decreases linearly as the amount of biting increases regardless of the rotational speed of the rotary drive roll 411. Even when the shaft rotation speed is the same, the sheet conveyance speed is slower when the amount of biting is large than when the amount of biting is small. This is because the amount of biting of the pressing roll 421 with respect to the endless belt 413 increases. This is probably because the rotation drive roll 411 slips.

  FIGS. 8 and 9 summarize the contents shown in the graphs of FIGS. 6 and 7 in a table.

  FIG. 8 shows data that is the basis of the graph shown in FIG. In the roll decurler unit 3, the movement of the correction roll 32 is allowed so that the amount of biting of the transport drive shaft 31 into the correction roll 32 varies between 0.1 mm and 2.2 mm. Here, five biting amounts (# 1 to # 5) from 0.1 mm to 2.2 mm are representatively selected.

  In FIG. 8, a column of “adjusted shaft speed setting value A ′” is provided at the right end, and “A” indicating the same value as the shaft speed setting value A is described for # 1. For # 2, “0.9974A” is described which means a value 0.9974 times the shaft speed setting value A. This “adjusted shaft speed setting value A ′” is the amount of biting in order to maintain the paper conveyance speed realized by each axis speed setting value A when the biting amount is # 1 regardless of the change in biting amount. This is the axis speed setting value set for each. For example, when the shaft speed setting value A is 500 mm / sec, the paper conveyance speed when the biting amount is # 1 is 501.8 mm / sec, but the biting amount is set while the shaft speed setting value A remains 500 mm / sec. If it is changed to # 2, the sheet conveying speed is increased from 501.8 mm / sec to 503.3 mm / sec. Therefore, in order to maintain the sheet conveyance speed at 501.8 mm / sec even when the biting amount is changed to # 2, the axis speed setting value is shown in the column of “Adjusted Axis Speed Setting Value A ′”. The current shaft speed setting value A may be 498.7 mm / sec, which is 0.9974 times 500 mm / sec.

  FIG. 9 shows data that is the basis of the graph shown in FIG. In the belt decurler section 4, the pressing member 42 is allowed to move so that the amount of biting of the pressing roll 421 into the endless belt 413 changes between 2.2 mm and 7.3 mm. Here, three biting amounts (# 1 to # 3) from 2.2 mm to 7.3 mm are typically selected.

  In FIG. 9, a column of “adjusted shaft speed setting value B ′” is provided at the right end, and “B” meaning the same value as the shaft speed setting value B is described for # 1. For # 2, “1.0392B”, which is 1.0392 times the shaft speed set value B, is described. This “adjusted shaft speed setting value B ′” is also used for each biting amount in order to maintain the sheet conveyance speed realized at each axis speed setting value B when the biting amount is # 1, regardless of the change in the biting amount. This is the axis speed setting value set to.

  The main body control unit 101 provided in the image forming apparatus 1 determines the amount of biting in the roll decurler unit 3 from information on the paper to be used obtained from the operation by the operator. In addition, the main body control unit 101 determines the roll decurler unit 3 based on the determined amount of biting, information on the sheet conveyance speed obtained from the operation by the operator, and a table created based on the rightmost data in FIG. A shaft speed setting value A ′ of the transport drive shaft 31 is determined. The main body control unit 101 transmits the determined shaft speed setting value A ′ to the decurler device 1. In the decurler device 1, the transport driving shaft 31 is rotated at the received shaft speed setting value A ′ through the local motor M <b> 2 that applies a rotational driving force to the transport driving shaft 31. Further, the main body control unit 101 adjusts the rotation angle of the first stepping motor SM1 so that the amount of biting in the roll decurler unit 3 becomes the determined amount of biting.

  Further, the main body control unit 101 determines the amount of biting in the belt decurler unit 4 from information on paper, etc., and the table created based on the determined amount of biting, information on the paper conveyance speed, and the data on the right end of FIG. Based on the above, the shaft speed set value B ′ of the rotational drive roll 411 of the belt decurler unit 4 is determined. The main body control unit 101 rotates the rotation driving roll 411 with the determined shaft speed setting value B ′ through the main motor M <b> 1 that applies a rotation driving force to the rotation driving roll 411. Further, the main body control unit 101 adjusts the rotation angle of the second stepping motor SM2 so that the amount of biting in the belt decurler unit 4 becomes the determined amount of biting.

  FIG. 10 is a diagram illustrating the relationship between the amount of biting and the shaft speed setting value in each of the roll decurler unit and the belt decurler unit.

  In FIG. 10, as an example, the sheet conveying speed 448.5 mm / sec is maintained in both the roll decurler unit 3 and the belt decurler unit 4 for all combinations of biting amounts in the roll decurler unit 3 and the belt decurler unit 4. The shaft speed setting value A ′ and the shaft speed setting value B ′ are shown.

  In the decurler device 1, paper conveyance in the roll decurler unit 3 is controlled using a drive system of a local motor M2 provided in the decurler device 1, and paper conveyance in the belt decurler unit 4 is driven by a main motor M1 provided on the main body side. The system is controlled using. For example, if the sheet conveyance in the roll decurler unit 3 and the sheet conveyance in the belt decurler unit 4 are performed under the same drive system, a difference occurs between the sheet conveyance speed in the roll decurler unit 3 and the sheet conveyance speed in the belt decurler unit 4. There is a fear. Therefore, in the decurler device 1, the sheet conveyance speed in the roll decurler unit 3 and the sheet conveyance speed in the belt decurler unit 4 are adjusted using separate drive systems for each decurler unit, and the sheet conveyance speed is made to coincide with high accuracy. . Thereby, in the decurler device 1, for example, Z folding due to a high paper conveyance speed in the roll decurler unit 3 and a low paper conveyance speed in the belt decurler unit 4 is prevented. The above is an explanation of the reason why the drive source is made a separate system in the roll decurler unit 3 and the belt decurler unit 4.

  Here, the description of the decurler device 1 is temporarily interrupted, and the fixing device 400 provided in the image forming apparatus 100 will be described.

  FIG. 11 is a schematic configuration diagram around the fixing device.

  A fixing device 400 shown in FIG. 11 includes a heating unit 401, a pressure roll 402, and a cooling fan 403.

  The heating unit 401 includes a heating belt 4013, a first heating roll 4011, a second heating roll 4012, and a tension roll 4014. The first heating roll 4011 heats the heating belt 4013 from the inside of the heating belt 4013, and the second heating roll 4012 heats the heating belt 4013 from the outside of the heating belt 4013.

  The cooling fan 403 is disposed below the pressure roll 402 and prevents the pressure roll 402 from overheating by blowing air from below the pressure roll 402.

  FIG. 11 shows the suction conveyance device 650 disposed on the upstream side and the downstream side on the conveyance path of the sheet with the fixing device 400 interposed therebetween, and the adsorption conveyance device 650 on the downstream side of the fixing device 400. Further, a cooling device 740 is shown further downstream.

  The suction conveyance device 650 includes a conveyance belt 651, a drive roll 653, a tension roll 654, and an exhaust fan 652.

  The conveyance belt 651 has a small-diameter hole penetrating the front and back, and the air surrounded by the conveyance belt 651, the drive roll 653, and the tension roll 654 is discharged by the exhaust fan 652. The inside of this space is set to a negative pressure, and the sheet is adsorbed on the surface of the conveyance belt 651.

  Further, FIG. 11 shows a sheet immediately before the leading end reaches a nip formed by the heating unit 401 and the pressure roll 402, and here, a sheet with ridges whose both ends face downward. P is indicated by a solid line, and a sheet P ′ with a ridge that jumps up at both ends is indicated by a dotted line.

  When the paper P ′ indicated by the dotted line enters the nip portion, the leading edge of the paper P ′ collides with the heating belt 4013, so that the corner of the paper called a so-called dog ear is broken, or the paper P ′. If the tip of the sheet cannot smoothly enter the nip portion, jamming may occur.

  Therefore, it is conceivable to suppress the jumping by strengthening the exhaust fan 652 and adsorbing the tip to the adsorption belt 651. However, if the exhaust fan 652 is operated strongly, an air flow that lowers the temperature of the heating belt 4013 is generated. For this reason, in this image forming apparatus 100, the exhaust fan 652 operates only with the minimum necessary and cannot be used to suppress the jumping up.

  By the way, it is considered that the curl like the paper P ′ shown in FIG. 11 is attached to the paper on which the toner image is fixed only on one side, and the dog ear or jam is divided into two times for each side. In the double-sided printing mode in which the fixing is performed, there is a high possibility that it frequently occurs at the second fixing. For example, in the double-sided printing mode, a sheet having a toner image fixed on one side and conveyed on the conveyance path shown in FIG. 5 is wound with the central portion protruding upward after passing through the roll decurler unit 3 and the belt decurler unit 4. If there is a crease, then the state of the sheet that has been transported through the front / back reversing path R2 and transferred to the fixing device 400 after receiving the transfer of the toner image on the other side is the sheet P shown in FIG. It becomes the same state as'. Therefore, in this decurler device 1, when the double-sided printing mode is selected, and the paper having finished fixing the toner image on one side has a curl with a central portion protruding upward, When correction is performed so that a curl with a slightly protruding central part is attached, and the paper having finished fixing the toner image on one side originally has a curl with a central part protruding downward Then, correction is performed to weaken the curl whose central part protrudes downward to such an extent that the curl does not become a curl whose central part protrudes upward. Further, in the decurler device 1, when the double-sided printing mode is selected, the paper on which the toner image has been fixed on one side has a curl whose central portion slightly protrudes downward. There is no correction. The decurler apparatus 1 estimates the paper curl after fixing based on various conditions such as temperature and humidity and image density in addition to the paper type selected by the operator, and corrects the paper curl as described above. is doing. Further, in this decurler device 1, even if conditions such as temperature and humidity and image density change, the curl after the toner image has been fixed is a paper type in which the central portion always protrudes slightly downward. If the paper type selected by the operator corresponds to the recognized paper type, no correction is performed. Further, in the decurler device 1, when the single-sided printing mode is selected, the curl with the central portion protruding upward and the central portion protrudes downward on the paper on which the toner image has been fixed on one side. Even if any of the curl is attached, correction is performed to weaken each curl. Here, the description of the embodiment is temporarily interrupted, and an example will be described.

  In this embodiment, the suction fan of the suction conveyance device disposed in the immediate upstream side in the paper conveyance direction of the printer of Fuji Xerox printer can be switched ON (used for output low) and OFF. In this case, a high temperature (35 ° C.) and high humidity (70%) and a normal temperature (20 ° C.) and normal humidity (40%) were prepared as operating environments. Also, for paper to be transported, the same size SRA3 but not surface-treated and different basis weight and plain paper having the same size SRA3 but surface-treated different basis weight Prepared with paper.

  In this embodiment, after transferring and fixing a toner image on one side of each of the above-described various sheets, the biting amount combination in each of the roll decurler unit and the belt decurler unit is changed in units of 45 sheets, and for some sheets, 45 sheets are used. Paper that has been curled and corrected when the suction fan is turned on and off, and has been transferred to the fixing device again for fixing after the transfer of the toner image to the other side. The tendency of the behavior of the front end of the sheet immediately before entering the nip portion of the fixing device, the maximum amount of jumping, the occurrence timing of jamming, and the number of dog ears generated were observed and evaluated. For paper other than some paper, correct the curl with the suction fan turned on, and transfer the toner image to the other side of the paper and transfer it to the fixing device again for fixing. The tendency of the behavior of the front end of the paper immediately before entering the nip portion of the fixing device, the maximum amount of jumping, the occurrence timing of the jam, and the number of generated dog ears were observed and evaluated. In addition, as the amount of biting in the roll decurler part, three stages of large (R3), medium (R2), and small (R1) are prepared, and as the amount of biting in the belt decurler part, many (B3), medium (B2), small ( Three stages of B1) were prepared. The greater the amount of bite, the stronger the correction force. If the amount of bite is the same, the correction force of the paper is also equal.

  First, an experiment conducted in a room temperature and humidity environment will be described.

  Comparative Example 1 shows that the amount of biting in the roll decurler unit is R3 and the amount of biting in the belt decurler unit with the suction fan turned off with respect to P paper which is plain paper having a basis weight of 64 gsm in an environment of normal temperature and humidity. This is a case where the curl is corrected in B1.

  Comparative Example 2 is the same as Comparative Example 1 except that the suction fan is turned on.

  Comparative Example 3 is the same as Comparative Example 2 except that J paper, which is plain paper having a basis weight of 82 gsm, is used as the paper.

  Comparative Example 4 is the same as Comparative Example 1 except that the amount of biting in the roll decurler section is R2.

  Comparative Example 5 is the same as Comparative Example 2 except that the amount of biting in the roll decurler section is R2.

  Comparative Example 6 is the same as Comparative Example 3 except that the amount of biting in the roll decurler section is R2.

  Comparative Example 7 is the same as Comparative Example 1 except that the amount of biting in the roll decurler section is R1.

  Comparative Example 8 is the same as Comparative Example 2 except that the amount of biting in the roll decurler section is R1.

  Comparative Example 9 is the same as Comparative Example 3 except that the amount of biting in the roll decurler section is R1.

  Example 1 is the same as Comparative Example 7 except that the amount of biting in the belt decurler section is B2.

  Example 2 is the same as Comparative Example 8 except that the amount of biting in the belt decurler section is B2.

  Example 3 is the same as Comparative Example 9 except that the amount of biting in the belt decurler section is B2.

  Comparative Example 10 is a case where OKT paper, which is a coated paper having a basis weight of 73 gsm, is used to correct curling wrinkles by setting the amount of biting in the roll decurler to R3 and the amount of biting in the belt decurler to B1 with the suction fan off. It is.

  Example 4 is the same as Comparative Example 10 except that the suction fan is turned on.

  Example 5 is the same as Example 4 except that JD paper, which is a coated paper having a basis weight of 104 gsm, is used as the paper.

  Comparative Example 11 is the same as Comparative Example 10 except that the amount of biting in the roll decurler section is R2.

  Example 6 is the same as Comparative Example 11 except that the suction fan is turned on.

  Example 7 is the same as Example 6 except that JD paper, which is a coated paper having a basis weight of 104 gsm, is used as the paper.

  Example 8 is the same as Comparative Example 11 except that the amount of biting in the roll decurler section is R1.

  Example 9 is the same as Example 8 except that the suction fan is turned on.

  Example 10 is the same as Example 7 except that the amount of biting in the roll decurler section is R1.

  Example 11 is the same as Example 8 except that the amount of biting in the belt decurler section is B2.

  Example 12 is the same as Example 11 except that the suction fan is turned on.

  Example 13 is the same as Example 10 except that the amount of biting in the belt decurler section is B2.

  Among the evaluation items, the behavior is ‘×’ when it is not amusing at any time, ‘△’ when the paper tip is slightly fluttered, and ‘◯’ when stable. In addition, the maximum amount of jumping is the value detected by the optical sensor at the leading edge of the paper, the number of jammed sheets out of 45 for jamming, and the number of 45 for dogyear. It shows how many sheets have occurred. Regarding the comprehensive judgment, “×” indicates that there is a problem in the correction mode, “Δ” indicates that the correction mode is within the allowable range, and “B” indicates that there is no problem in the correction mode.

  Table 1 shows contents of Examples 1 to 13 and Comparative Examples 1 to 11 performed in a normal temperature and humidity environment.

  In Comparative Example 1, the behavior was ‘×’, the maximum amount of curling up was 8 mm, no jamming occurred, and one dog ear occurred out of 45. Therefore, the overall judgment was ‘×’.

  In Comparative Example 2, there is no occurrence of jam or dog-ear, but the behavior is ‘Δ’ and the maximum amount of curling up is 8 mm, so the overall judgment is ‘×’.

  In Comparative Example 3, although the jam did not occur, the behavior was ‘×’, the maximum amount of curling up was 14 mm, and 1 out of 45 dog ears occurred, so the comprehensive judgment was ‘×’.

  In Comparative Example 4, there is no occurrence of jam or dog-ear, but the behavior is ‘Δ’ and the maximum amount of curling up is 8 mm, so the overall judgment is ‘×’.

  In Comparative Example 5, there was no occurrence of jam or dog-ear, but the behavior was ‘Δ’ and the maximum amount of jump was 9 mm, so the overall judgment was ‘×’.

  In Comparative Example 6, although there was no jamming, the behavior was ‘×’, the maximum amount of curling up was 9 mm, and 1 out of 45 dog ears occurred, so the comprehensive judgment was ‘×’.

  In Comparative Example 7, although there was no occurrence of jam and dog-ear, the behavior was ‘Δ’ and the maximum amount of curling up was 8 mm, so the overall judgment was ‘×’.

  In Comparative Example 8, there was no occurrence of jam or dog-ear and the behavior was “◯”, but the maximum amount of jump was 9 mm, so the overall judgment was “x”.

  In Comparative Example 9, there was no occurrence of jam or dog-ear, but the behavior was ‘Δ’ and the maximum amount of jump was 9 mm, so the overall judgment was ‘×’.

  In Example 1, since there was no occurrence of a jam or a dog-ear, the behavior was “◯”, and the maximum amount of curling up was 3 mm, the comprehensive judgment was “Δ”.

  In Example 2, there was no occurrence of a jam or a dog-ear, the behavior was “◯”, and the maximum amount of curling up was 4 mm, so the overall judgment was “Δ”.

  In Example 3, there was no occurrence of a jam or dog-ear, the behavior was “◯”, and the maximum amount of curling up was 5 mm, so the overall judgment was “Δ”.

  In Comparative Example 10, the behavior was ‘Δ’, the maximum amount of curling up was 6 mm, and a jam occurred on the first of the 45 sheets, so the overall judgment was ‘×’.

  In Example 4, there was no occurrence of a jam or dog-ear, the behavior was ‘Δ’, and the maximum amount of curling up was 5 mm, so the overall judgment was ‘Δ’.

  In Example 5, there was no occurrence of a jam or dog-ear, the behavior was “◯”, and the maximum amount of curling up was 6 mm, so the overall judgment was “Δ”.

  In Comparative Example 11, the behavior was ‘Δ’, the maximum amount of curling up was 4 mm, and a jam occurred on the first of 45 sheets, so the comprehensive judgment was ‘×’.

  In Example 6, there was no occurrence of a jam or a dog-ear, the behavior was “◯”, the maximum amount of curling up was 3 mm, and the overall judgment was “Δ”.

  In Example 7, there was no occurrence of a jam or a dog-ear, the behavior was “◯”, the maximum amount of curling up was 4 mm, and the comprehensive judgment was “Δ”.

  In Example 8, there was no occurrence of jam or dog-ear, the behavior was “◯”, the maximum amount of curling up was 1 mm, and the overall judgment was “◯”.

  In Example 9, there was no occurrence of a jam or a dog-ear, the behavior was “◯”, and the maximum amount of curling up was 2 mm, so the overall judgment was “◯”.

  In Example 10, there was no occurrence of a jam or dog-ear, the behavior was “◯”, and the maximum amount of curling up was 1 mm, so the overall judgment was “◯”.

  In Example 11, there was no occurrence of jam and dog-ear, the behavior was “◯”, and the maximum amount of curling up was 0 mm, so the overall judgment was “◯”.

  In Example 12, there was no occurrence of jam and dog-ear, the behavior was “◯”, and the maximum amount of curling up was 2 mm, so the overall judgment was “◯”.

  In Example 13, there was no occurrence of jam or dog-ear, the behavior was “◯”, and the maximum amount of curling up was 0 mm, so the overall judgment was “◯”.

  From Comparative Examples 1 to 9 and Examples 1 to 3, in a normal temperature and humidity environment, the surface on which the toner image is fixed on plain paper having a basis weight of 64 gsm or more on which the toner image is fixed only on one side is shown. It was confirmed that the toner image transferred to the other side can be fixed almost satisfactorily regardless of whether the fan is turned on or off by strengthening the correction by the belt decurler part that is recessed and bounces up both ends.

  From Comparative Examples 10 and 11 and Examples 4 to 7, the surface on which the toner image was fixed on a coated paper having a basis weight of 73 gsm or more in which the toner image was fixed only on one side in a normal temperature and humidity environment. It was confirmed that even if the correction by the roll decurler that projects the toner is strong, the fixing of the toner image transferred to the other side can be barely performed if the fan is on.

  Furthermore, from Examples 8 to 13, in a normal temperature and normal humidity environment, if the correction force of the roll decurler portion and the belt decurler portion is equivalent to a coated paper having a basis weight of 73 gsm or more in which a toner image is fixed only on one side, It was confirmed that the toner image transferred to the other side can be fixed satisfactorily regardless of whether the fan is on or off.

  From the above, compared with plain paper, coated paper tends to have curling wrinkles with the central portion protruding downward due to the toner image fixing on one side, and the correction force by the belt decurler unit in double-sided printing mode is the correction force by the roll decurler unit. It was confirmed that it was not necessary to exceed that much.

  Next, experiments conducted in a high temperature and high humidity environment will be described.

  In Comparative Example 12, the amount of biting in the roll decurler unit is set to R3 and the amount of biting in the belt decurler unit with respect to P paper which is plain paper having a basis weight of 64 gsm in a high-temperature and high-humidity environment with the suction fan off. This is a case where the curl is corrected in B1.

  Comparative Example 13 is the same as Comparative Example 12 except that the suction fan is turned on.

  Comparative Example 14 is the same as Comparative Example 13 except that J paper, which is plain paper having a basis weight of 82 gsm, is used as the paper.

  Comparative Example 15 is the same as Comparative Example 12 except that the amount of biting in the roll decurler section is R2.

  Comparative Example 16 is the same as Comparative Example 13 except that the amount of biting in the roll decurler section is R2.

  Comparative Example 17 is the same as Comparative Example 14 except that the amount of biting in the roll decurler section is R2.

  Comparative Example 18 is the same as Comparative Example 12 except that the amount of biting in the roll decurler section is R1.

  Comparative Example 19 is the same as Comparative Example 13 except that the amount of biting in the roll decurler section is R1.

  Comparative Example 20 is the same as Comparative Example 14 except that the amount of biting in the roll decurler section is R1.

  Comparative Example 21 is the same as Comparative Example 18 except that the amount of biting in the belt decurler section is B2.

  Comparative Example 22 is the same as Comparative Example 19 except that the amount of biting in the belt decurler section is B2.

  Comparative Example 23 is the same as Comparative Example 20 except that the amount of biting in the belt decurler section is B2.

  Example 14 is the same as Comparative Example 18 except that the amount of biting in the belt decurler section is B3.

  Example 15 is the same as Comparative Example 19 except that the amount of biting in the belt decurler section is B3.

  Example 16 is the same as Comparative Example 20 except that the amount of biting in the belt decurler section is B3.

  In Comparative Example 24, the curling wrinkle was corrected by setting the bite amount of the roll decurler part to R3 and the bite amount of the belt decurler part to B1 with the suction fan turned off with respect to the OKT paper having a basis weight of 73 gsm as the paper. Is the case.

  Example 17 is the same as Comparative Example 24 except that the suction fan is turned on.

  Comparative Example 25 is the same as Example 17 except that JD paper, which is a coated paper having a basis weight of 104 gsm, is used as the paper.

  Example 18 is the same as Comparative Example 24 except that the amount of biting in the roll decurler section is R2.

  Example 19 is the same as Example 17 except that the amount of biting in the roll decurler section is R2.

  Comparative Example 26 is the same as Comparative Example 25 except that the amount of biting in the roll decurler section is R2.

  Example 20 is the same as Comparative Example 24 except that the amount of biting in the roll decurler section is R1.

  Example 21 is the same as Example 17 except that the amount of biting in the roll decurler section is R1.

  Example 22 is the same as Comparative Example 25 except that the amount of biting in the roll decurler section is R1.

  Table 2 shows contents of Examples 14 to 22 and Comparative Examples 12 to 26 performed in a high temperature and high humidity environment.

  In Comparative Example 12, since the behavior was “×”, the maximum amount of bounce was 14 mm, a jam occurred on the fifth of the 45 sheets, and the dog ear occurred on the four sheets before the jam occurred, the comprehensive judgment was “×”. 'And.

  In Comparative Example 13, the behavior was “×”, the maximum amount of bounce was 14 mm, a jam occurred on the fifteenth of the 45 sheets, and the dog ear had occurred two by the time the jam occurred. 'And.

  In Comparative Example 14, the behavior was “×”, the maximum amount of bounce was 16 mm, the jam occurred on the 10th sheet out of 45 sheets, and the dog ear had occurred 5 sheets by the time of the jam occurrence. 'And.

  In Comparative Example 15, the behavior was “×”, the maximum amount of bounce was 9 mm, jam occurred on the 20th sheet out of 45 sheets, and the dog ear had occurred 3 sheets by the time of jam occurrence. 'And.

  In Comparative Example 16, although the jam did not occur, the behavior was ‘×’, the maximum jump amount was 12 mm, and dog ears occurred in 6 out of 45 sheets, so the comprehensive judgment was ‘×’.

  In Comparative Example 17, the behavior was “×”, the maximum amount of bounce was 12 mm, a jam occurred on the fifteenth sheet out of 45 sheets, and the dog ear had occurred three by the time the jam occurred. 'And.

  In Comparative Example 18, although the jam did not occur, the behavior was ‘×’, the maximum amount of curling up was 8 mm, and dog ears occurred in 1 out of 45 sheets, so the comprehensive judgment was ‘×’.

  In Comparative Example 19, although the jam did not occur, the behavior was ‘×’, the maximum amount of curling up was 11 mm, and dog ears occurred in 8 out of 45 sheets, so the comprehensive judgment was ‘×’.

  In Comparative Example 20, although there was no jamming, the behavior was ‘×’, the maximum amount of curling up was 8 mm, and dog ears occurred in 3 out of 45 sheets, so the comprehensive judgment was ‘×’.

  In Comparative Example 21, since the behavior was “×”, the maximum amount of bounce was 7 mm, jam occurred on the 31st sheet out of 45 sheets, and one dog ear occurred before the jam occurred, the comprehensive judgment is “×”. 'And.

  In Comparative Example 22, although the behavior was “◯” and no jam or dog-ear occurred, the maximum amount of jump was 8 mm, so the comprehensive judgment was “x”.

  In Comparative Example 23, although jam and dog-ear did not occur, the behavior was “Δ” and the maximum amount of jump was 6 mm, so the comprehensive judgment was “x”.

  In Example 14, there was no occurrence of jam or dog-ear, the behavior was ‘Δ’, and the maximum amount of curling up was 2 mm, so the overall judgment was ‘Δ’.

  In Example 15 and Example 16, there was no occurrence of a jam or dog-ear, the behavior was “◯”, and the maximum amount of curling up was 2 mm, so the overall judgment was “◯”.

  In Comparative Example 24, the behavior was “△”, the maximum amount of bounce was 5 mm, a jam occurred on the 20th sheet out of 45 sheets, and the dog ear had occurred on one sheet by the time of jam occurrence. X '.

  In Example 17, there was no occurrence of a jam or dog-ear, the behavior was “◯”, and the maximum amount of curling up was 5 mm, so the overall judgment was “Δ”.

  In Comparative Example 25, the behavior was ‘Δ’ and no jamming or dog-ear occurred, but the maximum amount of jump was 9 mm, so the overall judgment was ‘×’.

  In Example 18, there was no occurrence of jam and dog-ear, the behavior was ‘Δ’, and the maximum amount of curling up was 5 mm, so the overall judgment was ‘Δ’.

  In Example 19, there was no occurrence of a jam or dog-ear, the behavior was “◯”, and the maximum amount of curling up was 4 mm, so the overall judgment was “Δ”.

  In Comparative Example 26, the behavior was ‘Δ’ and there was no occurrence of jam and dog-ear, but the maximum amount of jump was 8 mm, so the overall judgment was ‘×’.

  In Example 20, there was no occurrence of a jam or a dog-ear, the behavior was “◯”, the maximum amount of curling up was 3 mm, and the overall judgment was “Δ”.

  In Example 21, there was no occurrence of a jam or dog-ear, the behavior was “◯”, the maximum amount of curling up was 4 mm, and the overall judgment was “Δ”.

  In Example 22, there was no occurrence of jam and dog-ear, the behavior was “◯”, and the maximum amount of curling up was 2 mm, so the overall judgment was “◯”.

  From Comparative Examples 12 to 23 and Examples 14 to 16, in a high-temperature and high-humidity environment, the surface on which the toner image is fixed on plain paper having a basis weight of 64 gsm or more in which the toner image is fixed only on one side. It was confirmed that the toner image transferred to the other side cannot be fixed satisfactorily unless the correction by the belt decurler portion to be dented is performed strongly.

  From Comparative Examples 24 and 25 and Example 17, in a high-temperature and high-humidity environment, the correction force by the roll decurler portion is greater than that of the belt decurler portion with respect to a coated paper having a basis weight of 73 gsm in which the toner image is fixed only on one side. If it is strong, the toner image transferred to the other side can be fixed fairly well if the fan is on, but the coated paper with a basis weight of 104 gsm cannot be satisfactorily performed even if the fan is on. It could be confirmed.

  Further, from Examples 18 and 19 and Comparative Example 26, in a high-temperature and high-humidity environment, the correction force by the roll decurler portion is higher than that of the belt decurler portion with respect to the coated paper having a basis weight of 73 gsm in which the toner image is fixed only on one side. If it is strong, the toner image transferred to the other side can be fixed well regardless of whether the fan is on or off. However, it can be confirmed that coated paper with a basis weight of 104 gsm cannot be satisfactorily performed even if the fan is on. It was.

  Further, from Examples 20 to 22, if the correction force of the roll decurler portion and the belt decurler portion is equivalent to a coated paper having a basis weight of 73 gsm or more in which a toner image is fixed only on one side in a high temperature and high humidity environment, It was confirmed that the toner image transferred to the other side can be fixed satisfactorily regardless of whether the fan is on or off.

  From the above, even in high-temperature and high-humidity environments, coated paper is more likely to have curling wrinkles that protrude downward in the center due to toner image fixation on one side, and correction by the belt decurler in double-sided printing mode. It was confirmed that the force does not need to exceed the correction force by the roll decurler. Furthermore, it was confirmed that the degree of correction force by the belt decurler portion exceeding the correction force by the roll decurler portion needs to be larger than that in a normal temperature and normal humidity environment under a high temperature and high humidity environment. The above is the description about the device for suppressing the occurrence of jam in the double-side mode. The above is the description of the embodiment.

  Hereinafter, the decurler device 1 will be described in more detail.

  The decurler device 1 is a device that can be pulled out from the main body housing of the image forming apparatus 100 together with the cooler 740 shown in FIG. Various motors for supplying driving force to the decurler device 1 are arranged on the side.

  FIG. 12 is an external perspective view of the decurler device pulled out from the main body housing.

  FIG. 12 shows the decurler device 1 fixed on the drawer plate 102 together with the cooling device 740. In FIG. 12, for convenience of explanation, illustration of a fixing member that fixes the decurler device 1 to the upper surface of the drawer plate 102 is omitted.

  The total weight of the cooling device 740 and the decurler device 1 together with the drawer plate 102 having both of them fixed to the upper surface is in the unit of 100 kg. For this reason, a guide is provided on the upper surface of the drawer plate 102 so that the decurler device 1 does not collide with other members in the main body casing when the operator pushes the drawer plate 102 toward the main body when returning to the main body casing. A member 103 is provided.

  FIG. 12 shows a state in which the first cutout 121a and the second cutout 121b are provided on the bottom side surface 121 of the lower housing 12 of the decurler device 1.

  Further, FIG. 12 shows a protruding member 900 provided on the back side of the main body housing.

  The protruding member 900 includes a lower portion 901 that enters the guide member 103 as the drawer plate 102 moves, and an upper portion 902 that contacts the bottom side surface 121 of the decurler device 1 as the drawer plate 102 moves. . The upper portion 902 is provided with a first convex portion 9021 and a second convex portion 9022 that protrude by urging of a spring provided therein, but are depressed when a force exceeding a certain level is applied and sink into the upper portion 902. It has been. As the drawer plate 102 moves, the protruding member 900 moves along the bottom side surface 121 of the decurler device 1 and the first convex portion 9021 faces the first notch 121a, and the first convex portion 9021 is the second notch. At the moment of facing 121b, the first protrusion 9021 is fitted into the first cutout 121a and the second cutout 121b, respectively. Further, at the moment when the second convex portion 9022 faces the second notch 121b, the second convex portion 9022 is fitted into the second notch 121b. For convenience of explanation, FIG. 12 shows a state in which the protruding member 900 is completely pulled out from the guide member 103. However, actually, even if the drawer plate 102 is pulled out from the main body housing to the maximum extent. In addition, the first convex portion 9021 is fitted in the second notch 121b, and the tapered portion 9011 of the lower portion 901 does not come out from the inside of the guide member 103. On the other hand, in a state where the drawer plate 102 is completely housed in the main body housing, the first convex portion 9021 is in a state of being fitted into the first notch 121a, and the second convex portion 9022 is in a state of being fitted into the second notch 121b. become.

  With such a configuration, the orbit of the drawer plate 102 on which the decurler device 1 is placed when the drawer plate 102 is attached to and detached from the main body housing is stable. Collisions with the device 1 are avoided.

  Next, an opening / closing mechanism of the decurler device 1 that is divided into an upper part and a lower part with a sheet conveyance path as a boundary will be described.

  FIG. 13 is an external perspective view of a lock mechanism for locking the upper portion with respect to the lower portion of the decurler device.

  FIG. 13 shows a state where the upper portion of the decurler device 1 is locked to the lower portion of the decurler device 1 by the lock mechanism 7.

  13 includes an operation lever 70, an upper plate 71 to which the operation lever 70 is attached, and a pressing plate attached to the surface of the upper plate 71 opposite to the surface to which the operation lever 70 is attached. 72, a torsion spring 73, a through shaft 74 in a state where the torsion spring 73 is wound, and an upper frame 11 fixed to the upper housing 11, and fixed to both ends of the through shaft 74 to rotatably support the through shaft 74. A lock member 76, a lock shaft 78 on which the lock member 76 is hooked, and a lower frame 77 provided with the lock shaft 78 and attached to the lower housing 12 are provided. One end of the torsion spring 73 is fixed to the through shaft 74, and the other end is supported by the upper frame 75. In this lock mechanism 7, when the operation lever 70 is lifted upward and the lock member 76 is removed from the lock rod 78, the lock is released. After the release, when the operation lever 70 is pushed downward forcefully, the upper part of the device is locked to the lower part of the device. Is done.

  14 is a perspective view from the side of the locking mechanism shown in FIG.

  FIG. 14 shows operations of the pressing plate 72, the torsion spring 73, the through shaft 74, and the lock member 76 in response to the operation of the operation lever 70. The penetrating shaft 74 has a semi-cylindrical shape at the portion exposed to the outside of the upper frame 75, but on the inner side of the upper frame 75, there is a pressing plate positioned above the semi-cylindrical shape. A plate-like portion 741 that receives a pressing force from 72 has a shape that protrudes across a gap formed in a part along the axial direction. The torsion spring 73 is wound around the semi-cylindrical portion of the through shaft 74 through this gap.

  Part (a) of FIG. 14 shows the state of these members when the operation lever 70 is not operated, which is also shown in FIG. 13, in which the other end 731 of the torsion spring 73 is the upper frame. A state is shown in which the lock member 76 is supported on the bottom surface of 75 and is hooked to the lock shaft 78 by the urging force in the direction of the arrow shown in part (a) of FIG.

  Further, part (a) of FIG. 14 shows a state in which a gap of an angle α is provided between the plate-like portion 741 of the penetrating shaft 74 and the pressing plate 72. By this gap, the pressing plate 72 has a so-called “play” between the horizontal state and the state inclined by the angle α counterclockwise.

  Here, part (b) of FIG. 14 shows the state of these members when the lock shaft 78 that is actually provided is not provided. Here, the penetrating shaft 74 and the lock member rotated clockwise from the state shown in part (a) of FIG. 14 in order to cancel the biasing force in the direction of the arrow shown in part (a) of FIG. 76 is shown.

  Part (c) of FIG. 14 shows a state in which the pressing plate 72 is tilted counterclockwise by the angle α as the operating lever 70 is lifted counterclockwise by the angle α. However. Since this is within the range of “play” described above, there is no change between the through shaft 74 shown in part (a) of FIG.

  In part (d) of FIG. 14, the operating lever 70 is lifted counterclockwise to an angle B (β> α) against the biasing force in the direction of the arrow wetted by part (a) of FIG. Thus, the pressing plate 72 is tilted counterclockwise by an angle β, and the plate-like member 741 receives the pressing force from the pressing plate 72. The through shaft 74 rotates counterclockwise by an angle (β−α). As a result, a state in which the lock member 76 starts to be separated from the lock shaft 78 is shown.

  In part (e) of FIG. 14, when the operation lever 70 is further raised counterclockwise to an angle γ (γ> β), the pressing plate 72 is tilted counterclockwise by the angle γ. A pressing force from the pressing plate 72 is received. The penetrating shaft 74 rotates counterclockwise by an angle (γ−α). As a result, the lock member 76 is shown far away from the lock shaft 78. A stopper 711 is provided at the bottom of the upper plate 71 to which the operation lever 70 is fixed. The operation of the operation lever 70 prevents the pressing plate 72 from rotating clockwise as compared with the horizontal state. Only rotating around is allowed.

  FIGS. 15 to 18 are diagrams showing a flow of unlocking the decurler device.

  15 and 16 show side views of the decurler device 1 in the locked state, FIG. 15 shows a state where the operation lever 70 is not operated, and FIG. 16 shows a slight operation lever 70. Is shown being lifted. In the state of FIG. 16, the pressing plate 72 is still rotated counterclockwise by less than an angle α with respect to the horizontal. Therefore, even if the operating lever 70 is operated within the range shown in FIGS. 15 and 16, the presence of the “play” described in FIG. 14 does not lead to the unlocking operation.

  In FIG. 17, the operating lever 70 is further lifted than in FIG. 16, and the state shown in part (d) of FIG. 14, that is, the pressing plate 72 rotates counterclockwise at an angle α or more with respect to the horizontal. Thus, it is shown that the operation of the operation lever 70 is connected to unlocking.

  FIG. 18 shows a state in which the lock member 76 is moved away from the lock shaft 78 and the operation lever 70 is released after the operation lever 70 is lifted, as shown in part (d) of FIG. Although illustration is omitted, when the operation lever 70 is pushed down in the state shown in FIG. 18, the posture of the through shaft 74 is lowered in the state shown in part (b) of FIG. As a result, the distal end portion of the lock member 76 collides with the lock shaft material 78 for a moment, but thereafter, the lock shaft 78 starts to slide along the taper 761 provided at the distal end portion. When the lock shaft 78 completely slides the taper 761, the state shown in part (a) of FIG. 14 is obtained again.

  FIG. 19 is a diagram illustrating a state where the decurler device is locked and housed in the main body housing.

  FIG. 19 shows a state in which a convex portion 701 is provided on the upper surface of the operation lever 70 of the decurler device 1 so as to stand up toward the front frame 500 of the main body housing.

  The convex portion 701 is locked when the operation lever 70 of the decurler device 1 housed in the main body casing is erroneously lifted more than the “play” described above, and the lock is released in the main body casing. It is a stopper for preventing the above. That is, before the operation lever 70 is lifted so that the locked state is released, the protrusion 701 hits the front frame 500 of the main body casing, thereby preventing the lock release in the main body casing. The operation lever 70 is an example of an operation member. The lock mechanism 7 is covered with a cover 700.

  FIG. 20 is an external perspective view of the decurler device in which the upper part is released with respect to the lower part.

  In FIG. 20, in order from the lower left side, a transport drive shaft 31 of the roll decurler unit 3, a plurality of endless belts 413 arranged in a direction intersecting the paper transport direction of the belt decurler unit 4, a lower discharge guide 54, a lower rotary roll 52, The lower chute 62 is shown, and the correction roll 32, the paper guide 45, the pressing roll 421, the upper discharge guide 53, the upper rotating roll 51, and the upper chute 61 are shown in order from the upper left side. The decurler device 1 is provided with a torsion spring that generates a biasing force in the direction of lifting the upper part when the lock is released.

  In the decurler device 1, a roll decurler unit 3 that sandwiches a sheet to be conveyed with a pair of rolls is disposed on the upstream side in the conveyance and conveyance direction, and has a plurality of endless belts 413 arranged intermittently in a direction intersecting the sheet conveyance direction. The belt decurler section 4 is disposed on the downstream side. This is due to the following reason. Immediately after the sheet having passed through the cooler 740 has been sent to the decurler device 1, the surface of the sheet has not yet cooled down. For this reason, when a sheet that has not yet been cooled is sandwiched and conveyed by a member such as the belt decurler unit 4 in which a portion that contacts the surface of the sheet and a non-contact portion are mixed, a difference in gloss occurs on the surface of the sheet. Therefore, in the decurler device 1, the roll decurler unit 3 composed of a pair of rolls that uniformly contacts the paper surface is disposed on the side near the cooling device 74 where the surface of the conveyed paper is not yet cooled. Has been.

  FIG. 21 is a view showing a method of assembling the lower discharge guide.

  In FIG. 21, a protrusion 541 provided at one end of the lower discharge guide 54 is fitted into a hole 122 a provided in the back plate 122 provided on the back side of the lower housing 12, so that the lower discharge guide 54 A state in which the screw hole 541a provided at the other end is screwed is shown.

  By adopting such a configuration for the lower discharge guide 54, the decurler device 1 saves time and labor when the lower discharge guide 54 is attached.

  FIG. 21 shows a state where the upper chute 61 and the lower chute 62 are removed from the decurler device 1 shown in FIG. The upper chute 61 and the lower chute 62 are prepared in two types, a metal one and a resin one, and are exchangeable members depending on the paper to be used.

  However, the metal chute is heavier than the resin chute. For this reason, when a torsion spring that generates an urging force in the direction of lifting the upper part is adopted according to the metal chute when the lock is released, the upper part is opened when it is later replaced with a resin chute. The force is too strong, and a load is applied to the part connecting the upper part of the apparatus and the lower part of the apparatus. On the other hand, when this torsion spring is employed in accordance with the resin chute, if it is later replaced with a metal chute, there is a risk that the force to open the upper part is insufficient and inconvenience is caused. Therefore, the decurler device 1 is devised to ensure a stable urging force regardless of which chute is used.

  FIG. 22 is a diagram showing a connecting portion between the upper part and the lower part of the decurler device.

  FIG. 22 shows a connecting portion between the upper part and the lower part of the decurler device 1, and includes an upper bearing portion 112 attached to the upper housing 11 and a lower bearing attached to the lower housing 12. The connection shaft 80 which penetrates the part 123, these upper bearing parts 112 and the lower bearing part 123, and connects these, and the torsion spring 81 penetrated by this connection shaft 80 are shown. One end 811 of the torsion spring 81 is connected to the upper housing 11, and the other end 812 is hooked to either the first engagement hole 123 a or the second engagement hole 123 b formed in the lower bearing portion 123. The lower bearing portion 123 is an example of an attachment portion, and the torsion spring 81 is an example of an elastic member and an example of a toggle spring.

  One end 811 of the torsion spring 81 is connected to the upper casing 11, and the other end 812 is hooked on the first engagement hole 123a or the second engagement hole 123b of the lower casing 12, so that the torsion spring 81 has A biasing force that repels the action of closing the upper part is generated. In the decurler device 1, the urging force generated in the torsion spring 81 in the locked state is lifted to some extent when the lock is released by using this urging force.

  FIG. 22 shows a state in which the other end 812 of the torsion spring 81 is hooked into the second engagement hole 123b on the right side in FIG. In this case, the urging force generated for the operation of closing the upper portion is larger than when the other end 812 is engaged with the first engagement hole 123a. Therefore, when using a resin chute, the other end 812 is hooked on the first engagement hole 123a, and when using a metal chute, the other end 812 is hooked on the second engagement hole 123b. Even if the chute is replaced with any of the above, it is possible to generate a force that lifts the upper part to some extent when the lock is released.

  FIG. 23 is a diagram illustrating a harness cover that connects the upper part and the lower part.

  In the decurler device 1, a harness 910 for transmitting signals from various sensors arranged in the upper portion of the device to the lower portion of the connecting shaft that connects the upper portion and the lower portion of the device shown in FIG. Yes. In FIG. 23, a harness cover 920 that covers a bundle of harnesses 910 wound on the connecting shaft side is screwed.

  Thus, since the harness 910 connecting the upper part and the lower part is accommodated in the harness cover 920 on the connecting shaft side connecting the upper part and the lower part, the length of the harness 910 can be minimized and the harness 910 can be varied. Nor.

  By the way, the decurler device 1 is accommodated in the main body housing after the upper portion and the lower portion of the device are locked. When the upper portion is closed, the decurler device 1 includes a correction roll 32, a transport drive shaft 31, and the like. A device has been devised to weaken the resistance generated by the contact of the.

  FIG. 24 is a schematic diagram of a roll decurler unit.

  As described with reference to FIG. 4, when the decurler device 1 is pulled out from the main body housing, the coupler 13 attached to the end of the first rotating shaft 35 of the roll decurler unit 3 and the stepping motor provided on the main body side are provided. The connection with the drive shaft of SM1 is released. Further, when the upper part of the decurler device 1 is opened, the first eccentric shaft 35 shown in FIG. 2 and FIG. The first eccentric cam 34 is rotated by the torque generated by the shaft 34, and the center of gravity of the first eccentric cam 34 is positioned below the vertical direction passing through the axial center of the first rotating shaft 35.

  Part (a) of FIG. 24 shows the posture of the first eccentric cam 34 after the upper portion of the apparatus is opened. Part (b) of FIG. 24 shows a state in which the amount of biting of the transport drive shaft 31 with respect to the correction roll 32 in the roll decurler unit 3 is the largest. Part (c) of FIG. 24 shows a state where the amount of biting of the transport drive shaft 31 with respect to the correction roll 32 in the roll decurler unit 3 is the smallest. The posture of the first eccentric cam 34 shown in FIG. 24A is smaller in the amount of biting of the transport drive shaft 31 with respect to the correction roll 32 than the posture shown in part (b) of FIG. However, the amount of biting of the transport drive shaft 31 with respect to the correction roll 32 is slightly larger than that in the posture shown in part (c) of FIG. Therefore, it is inconvenient and inconvenient to close and lock the upper part of the apparatus while the first eccentric cam 34 remains in the posture shown in part (a) of FIG.

  Therefore, in the decurler device 1, as described below, the resistance is weakened by attaching a weight 36 to the first rotating shaft 35.

  FIG. 25 is a diagram showing a state in which the weight attached to the first rotation shaft is viewed in the direction of arrow Z shown in part (d) of FIG.

  FIG. 25 shows a weight 36 screwed to a part of the peripheral surface of the first rotation shaft 35. The weight 36 is such that when the upper part of the apparatus is opened, the first eccentric cam 34 has the least amount of biting of the transport drive shaft 31 with respect to the correction roll 32 as shown in part (c) of FIG. The weight 36 shown in part (d) of FIG. 24 cancels the torque generated in the single eccentric cam 34 in the posture shown in part (c) of FIG. The mounting position and weight are determined so as to generate torque to be generated. With such a device, in the decurler device 1, when the upper portion of the device is closed, the resistance generated by the contact between the correction roll 32 and the transport drive shaft 31 is weakened.

  FIG. 26 is a diagram showing another aspect of the embodiment shown in FIG.

  Part (a) of FIG. 26 shows a front view and a side view of the first eccentric cam 34 shown in FIG. Further, in part (a) of FIG. 26, the rotation center of the first eccentric cam 34 is indicated by “◯”, and the center of gravity is indicated by “×”.

  Part (b) of FIG. 26 includes a front view and a side view of an eccentric cam 340 that is partially thicker than the first eccentric cam 34 shown in part (a) of FIG. It is shown. The first eccentric cam 34 and the eccentric cam 340 have the same size and the same shape when viewed from the front. In FIG. 26B, the center of rotation of the eccentric cam 340 is indicated by “◯”, and the center of gravity is indicated by “×”.

  The eccentric cam 340 has a center of gravity positioned vertically below the rotation axis when the posture is such that the amount of biting of the transport drive shaft 31 with respect to the correction roll 32 is minimized as shown in part (c) of FIG. Thus, the thickness of a part of the first eccentric cam 34 is increased.

  The posture in which the amount of biting of the transport drive shaft 31 with respect to the correction roll 32 is minimized when the upper part of the apparatus is opened by using the eccentric cam 340 instead of the weight 36 shown in part (d) of FIG. Therefore, in the decurler device 1, when the upper portion of the device is closed, the resistance generated by the contact between the correction roll 32 and the transport drive shaft 31 is weakened. The above is description about the device which weakens the resistance which generate | occur | produces by contact with the correction | amendment roll 32 and the conveyance drive shaft 31, when closing an upper part.

  By the way, the correction roll 32 used in the roll decurler unit 3 of the decurler device 1 is a consumable formed of a material softer than the transport drive shaft 35 and is a member that needs to be replaced.

  However, the correction roll 32 is a member that needs to be rotatably supported, and the above-described first rotation shaft 35 and the like are disposed above. 2 is supported by the front and back side of the upper housing 11 shown in FIG. Therefore, in this decurler device 1, the trouble of replacement is saved by the device described below.

  FIG. 27 is a side view of the decurler device viewed from the cooler side.

  27 includes a straightening roll 32, a first holding member 33 that rotatably supports the straightening roll 32, and a through shaft 371 that penetrates the above-described through hole 332 that is formed in the first holding member 33. A first support member 37 that is screwed to the upper housing 11 is shown.

  FIG. 28 is an enlarged view of the first support member shown in FIG. 27.

  In FIG. 28, the top end of the through shaft 371 that is provided in the first support member 37 that supports the correction roll 32 and passes through the through hole 332 provided in the first holding member 33 is supported by the upper casing 11. Is shown. Although illustration of the opposite side is omitted, the tip of the penetrating shaft 371 is similarly supported by the upper housing 11 on the opposite side. The first holding member 33 is an example of a bearing member, and the first support member 37 is an example of a holding member.

  FIG. 29 is an external perspective view of the correction roll supported by the first support member.

  According to the configuration shown in FIG. 29, the rotation shaft 321 of the correction roll 32 is not directly held by the upper housing 11, but penetrates the through-hole 332 opened in the first member 33. 371 is directly held by the upper casing 11.

  FIG. 30 is a diagram illustrating a method of replacing the correction roll.

  Part (a) of FIG. 30 shows a state in which the screw 38 is removed from the upper housing 11.

  In part (b) of FIG. 30, the through shaft 371 is pulled out from the through hole, so that the straightening roll 32, the first holding member 33, and the connection between the first support member 37 and the upper housing 11 are connected. It is shown that the straightening roll 32 is pulled out in the direction of the arrow when it is unwound. With this configuration, in the decurler device 1, the correction roll 32 can be easily replaced.

  In the above-described embodiment, a tandem type color printer is shown as an example of the image forming apparatus. However, the image forming apparatus is not limited to this, and may be a monochrome printer that does not have an intermediate transfer belt, for example.

  In the above-described embodiment, the printer is shown as an example of the image forming apparatus. However, the image forming apparatus is not limited to the printer, and may be a copying machine or a facsimile, for example.

  In the above-described embodiment, the combination of the charger, the exposure device, and the developing device is shown as an example of the image forming unit. However, the image forming unit is not limited to this, and corresponds to, for example, an image on the image carrier. The toner may be directly attached aiming at the position.

DESCRIPTION OF SYMBOLS 1 Decurler apparatus 11 Upper housing | casing 12 Lower housing | casing 100 Image forming apparatus 3 Roll decurler part 31 Conveyance drive shaft 32 Correction roll 33 1st holding member 34 1st eccentric cam 35 1st rotating shaft 36 Weight 37 1st support member 38 Screw Reference Signs List 4 belt decurler 41 belt unit 42 pressing member 43 second rotating shaft 44 intermediate member 45 paper transport guide 46 second eccentric cam 400 fixing device 7 lock mechanism 70 operation lever 701 convex portion

Claims (4)

A first rotating body whose circumferential surface moves around,
The peripheral surface having a peripheral surface that is softer than the peripheral surface of the first peripheral member, and the peripheral surface is pressed against the peripheral surface of the first peripheral member, so that the peripheral member moves around the peripheral surface of the first peripheral member. A second rotating body through which a recording medium on which an image is formed passes between the moving first moving body and the first rotating body;
A first holding body holding the first peripheral body;
A second holding body that holds the second peripheral body and is releasably coupled to the first holding body;
An elastic force is applied to the first holding body and the second holding body. When the connection between the first holding body and the second holding body is released, the first holding body and the second holding body are moved to the first holding body and the second holding body. An elastic member to be separated by elastic force;
The elastic member is attached and the elastic force is applied, the elastic member is removable, and has a plurality of attachment positions having different elastic forces from each other, and
A medium straightening device comprising: The elastic member separates the first holding body and the second holding body from each other vertically;
The holding body that separates upward from the first holding body and the second holding body is a member in which at least a part of the member can be replaced with another member having a different weight. Item 10. The medium correction device according to Item 1. The elastic member is a toggle spring having at least one end attached to the attachment portion,
The medium correction device according to claim 1, wherein the attachment portion has a plurality of attachment positions where the angles of the toggle springs are different from each other. An image forming unit that forms an image on the surface of the recording medium;
A first rotating body whose circumferential surface moves around,
The peripheral surface having a peripheral surface that is softer than the peripheral surface of the first peripheral member, and the peripheral surface is pressed against the peripheral surface of the first peripheral member, so that the peripheral member moves around the peripheral surface of the first peripheral member. A second rotating body through which the recording medium passes between the moving body and the first rotating body;
A first holding body holding the first peripheral body;
A second holding body that holds the second peripheral body and is releasably coupled to the first holding body;
An elastic force is applied to the first holding body and the second holding body. When the connection between the first holding body and the second holding body is released, the first holding body and the second holding body are moved to the first holding body and the second holding body. An elastic member to be separated by elastic force;
The elastic member is attached and the elastic force is applied, the elastic member is removable, and has a plurality of attachment positions having different elastic forces from each other, and
An image forming apparatus comprising:

Images