JP4980856B2 - Recording medium transport path structure and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a recording medium conveyance path structure and an image forming device having the same capable of suppressing the enlargement of an open cover and easily dealing with jamming of a recording medium. <P>SOLUTION: A handle part 34 is mounted on a part of a separated section 36 of a switching claw G3b. An inverting guide member 32 is easily rotated in the direction of an arrow A by pressing an operating surface 34C of the handle part 34 with a user's finger in the direction of an arrow C and consequently conveyance paths P4 and P61 can be opened. Thus, since the handle part 34 is formed on the separated section 36 of the switching claw G3b, the inverting guide member 32 can be easily and properly rotated by pressing the operating surface 34c of the handle part 34 in the direction C without affecting the movement of the switching claw. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to a recording medium conveyance path structure including a guide member that opens a recording medium conveyance path by rotating, and an image forming apparatus including the recording medium conveyance path structure.

When an image is formed on a recording medium such as paper in an image forming apparatus such as a copying machine, a printer, or a facsimile, the occurrence of a so-called jam in which the recording medium is jammed in the conveyance path has been a burden for a long time. When a recording media jam occurs, the user is required to take some action to return the system to a normal operating state and restore the integrity of a particular job. In the past, various processing methods have been developed to reduce the occurrence of jams and minimize the burden on the user to recover from the jams.
For example, by opening the side cover of the cassette paper feeding unit, the jam processing from the cassette feeding path to the image forming unit is facilitated. Further, a double-sided conveying member is provided, and the double-sided conveying member is attached to the cover. There is known an invention that can be opened and closed about a shaft (see Patent Document 1).
In order to easily attach and detach the transfer roller unit of the image forming apparatus with one hand, a transfer roller, a support portion that rotatably supports the end portion of the transfer roller, and a connecting portion that connects the support portions are provided. Use the holder you have. A handle portion is formed at a central portion on the opposite side of the conveying surface formed at the connecting portion of the holder. And it has been proposed that the holder can be grasped and the holder can be taken out from the storage part of the apparatus main body for storing the holder with one hand (see Patent Document 2).
JP 2005-195759 A JP 2005-284078 A

In Patent Document 1, a double-sided conveyance member is attached to the cover so as to be openable and closable around an axis, and the recording medium can be easily jammed in the double-sided conveyance unit of the recording medium. In this case, although there is no description about providing a handle portion for opening the double-sided conveyance member, this handle portion is considered to be formed at the upper end opposite to the axis of the double-sided conveyance member. That is, in consideration of the description of Patent Document 2, it is conceivable that the handle portion is formed on the opposite side of the conveyance surface of the double-sided conveyance member.
However, in the thing of this patent document 1, when the handle part as described in patent document 2 is formed, when the discharge branch claw for inverting a recording medium is attached to this vicinity, the discharge branch In order to prevent the turning operation of the handle from interfering with the turning operation of the nail, it is necessary to be sufficiently separated from the handle. As a result, a long conveying path is formed, which causes a problem that the entire apparatus is enlarged.
The present invention has been made in consideration of the above circumstances, and has a recording medium conveyance path structure capable of suppressing the enlargement of the open cover and easily performing jam processing of the recording medium, and image formation provided with the same. An object is to provide an apparatus.

In order to solve the above problems, the invention described in claim 1 includes a first transport path, a second transport path and a third transport path branched from the first transport path, the second transport path, and a second transport path. A branching means for switching the conveyance path of the recording medium, and a guide member having a guide surface that respectively forms the first conveyance path and the third conveyance path. Is a recording medium transport path structure in which one end is rotatably mounted by a support shaft, and the third transport path is opened by the rotation of the guide member, and the guide member is disposed on the opposite side to the support shaft. And a plurality of switching claws attached to the rotating shaft so as to be spaced apart from each other, and the guide member is manually inserted into at least one separated portion of the plurality of switching claws. Rotate Characterized in that fitted with the handle portion.
According to a second aspect of the present invention, in the recording medium transport path structure according to the first aspect, the first transport path is a path for transporting a recording medium having an image formed on one side thereof, and the third transport path is , And a recording medium conveyance path for reversing the recording medium on which the image is formed on the one surface.
According to a third aspect of the present invention, in the recording medium conveyance path structure according to the first or second aspect, the guide member has a second guide surface that forms the first conveyance path, and the second guide surface is It is characterized in that it is rotatably attached to a second guide member attached to the third guide surface facing the first transport path so as to be openable and closable.

According to a fourth aspect of the present invention, in the recording medium conveyance path structure according to any one of the first to third aspects, the handle portion is attached to a rotation shaft of a separation portion of the plurality of switching claws at a root portion. It is characterized by that.
According to a fifth aspect of the present invention, in the recording medium conveyance path structure according to the fourth aspect, the rotating shaft mounting portion of the handle portion is provided with a notch portion that is notched in a circumferential direction that allows insertion of the rotating shaft. It is characterized by having.
According to a sixth aspect of the present invention, in the recording medium conveyance path structure according to any one of the first to fifth aspects, a conveyance guide surface of the recording medium is provided on a surface opposite to a manual operation surface of the handle portion. It is formed.
According to a seventh aspect of the present invention, in the recording medium transport path structure according to any one of the first to sixth aspects, the handle portion is formed in a different color from the switching claw.
According to an eighth aspect of the present invention, in the recording medium transport path structure according to any one of the first to seventh aspects, the handle portion is made of a plastic resin.

According to a ninth aspect of the present invention, in the recording medium conveyance path structure according to the eighth aspect, the handle portion is integrally formed with the switching claw.
According to a tenth aspect of the present invention, an image forming unit that forms an image on a recording medium, a first conveying path that conveys a recording medium on which an image is formed by the image forming unit, and a branch from the first conveying path. The second transport path and the third transport path, branching means for switching the transport path of the recording medium at the branch position of the second transport path and the third transport path, the first transport path and the third transport path. A guide member having a guide surface that forms a conveyance path, the guide member being rotatably attached to one end by a support shaft, and the third conveyance path being opened by the rotation of the guide member. 10. An image forming apparatus having a medium conveyance path structure, wherein the recording medium conveyance path structure is the recording medium conveyance path structure according to any one of claims 1 to 9.
According to an eleventh aspect of the present invention, in the image forming apparatus according to the tenth aspect, the image forming apparatus is any one of an electrophotographic copying machine, a laser beam printer, and a facsimile apparatus.

  According to the present invention, the guide member has the branching unit on the opposite side to the support shaft, and the branching unit is mounted on the rotating shaft with a plurality of switching claws spaced apart from each other. By attaching a handle portion for manually rotating the guide member to at least one separated portion of the plurality of switching claws, an increase in the size of the open cover can be suppressed and jamming of the recording medium can be easily performed. A possible recording medium conveyance path structure and an image forming apparatus including the same can be provided.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
An embodiment of the present invention will be described with reference to the drawings. The image forming apparatus of this embodiment is an application example of a full-color printer that employs a so-called tandem method. FIG. 1 is a central sectional view showing an outline of the full-color printer 100, and FIG. 2 is a central sectional view showing an outline of an image forming unit in the printer.
First, the internal configuration of the full-color printer 100 will be described with reference to FIGS. The full-color printer 100 includes four latent images as image forming means for forming images of each color of yellow (Y), cyan (C), magenta (M), and black (Bk). Drum-shaped photoconductors 2Y, 2M, 2C, and 2Bk, which are bodies, are arranged in parallel at equal intervals in the left-right direction in the drawing. During operation of the image forming apparatus 100, the image forming apparatus 100 is rotated in the direction of the arrow by a drive source (not shown).
Around the photoconductors 2Y, 2M, 2C, and 2Bk, members and devices necessary for an electrophotographic image forming apparatus such as a developing device are provided, and image forming units 1Y, 1M, 1C, and 1Bk are provided at four locations. Although it is configured, Y (yellow), C (cyan), M (magenta), and Bk representing the color are displayed after the number indicating each image forming device for convenience so as to correspond to the toner color of the image to be formed. (Black) will be added as a subscript. In particular, in the general description, these subscripts may be omitted. The four image forming units 1Y, 1C, 1M, and 1Bk all have the same configuration.

Focusing on the image forming unit 1Y including the yellow image photoreceptor 2Y shown in FIG. 2, a charging device 4Y including a charging roller 4aY, a developing roller 5aY, and a developing blade 5bY around the photoreceptor 2Y according to an electrophotographic process. Further, an image forming member such as a developing device 5Y having a screw 5cY and the like, a cleaning brush 3aY, a cleaning blade 3bY, a recovery screw 3cY and the like, and a cleaning device 3Y and the like are sequentially arranged.
The photoreceptor 2Y has a layer structure in which an organic semiconductor layer, which is a photoconductive substance, is provided on the surface of an aluminum cylinder having a diameter of about 30 to 120 mm. The members arranged around the other photoconductors 2C, 2M, and 2Bk are the same. That is, only the color of the toner used for image formation is different. It is possible to use a belt-like photoconductor.

  As shown in FIG. 1, below the photoconductors 2Y, 2C, 2M, and 2Bk, a laser beam corresponding to image data for each color is scanned on the surface of each photoconductor 2 that has been uniformly charged by a charging unit. An exposure device 8 for forming an electrostatic latent image is provided. Between each charging device 4 and each developing device 5, an elongated space is secured in the direction of the rotation axis of the photosensitive member 2 so that the laser light irradiated by the exposure device 8 enters the photosensitive member. . An exposure apparatus 8 in the illustrated example is a laser scanning type exposure apparatus using a laser light source, a polygon mirror, and the like. Beam light 8Y, 8C modulated from four semiconductor lasers (not shown) according to image data to be formed. , 8M, 8Bk. The exposure apparatus 8 accommodates optical parts and control parts by a metal or resin casing, and is provided with a light-transmitting dustproof member at the emission port on the upper surface. Although the embodiment is composed of a single housing, a plurality of exposure apparatuses can be individually provided in each image forming unit. In addition to an exposure apparatus that employs the above laser, an exposure apparatus that combines a known LED array and an imaging means can also be employed.

When the yellow (Y), cyan (C), magenta (M), and black (Bk) toners are consumed by the developing devices 5Y, 5C, 5M, and 5Bk that handle the respective colors, they are detected by a toner detection unit (not shown). The toner cartridges 40Y, 40C, 40M, and 40Bk that store the toners of the respective colors provided in the upper portion of the image forming apparatus 100 are supplied to the developing devices 5 by a supply unit (not shown). The outer shell of each toner cartridge is a container made of resin or paper, and is provided with a discharge port in part, and can be easily attached to and detached from the mounting portion TS of the image forming apparatus 100. Combined with individual toner replenishing means provided on the main body. In order to prevent the toner cartridge 40 of each color from being erroneously mounted and supplying toner to a developing device that handles different colors, the mounting portion TS and the toner cartridge 40 are paired with each other to provide a wrong mounting prevention means. is there.
As shown in FIG. 2, the developing devices 5Y, 5M, 5C, and 5Bk are provided with two screws 5c for stirring and conveying the toner and the carrier. When the developing device 5 is mounted on the image forming apparatus 100, one end of the toner replenishing means is connected to the upper portion of the left screw 5c in the drawing. The toner is supplied to the developing roller 5a rotating in the direction of the arrow by the screw 5c, but the thickness of the toner layer on the surface of the developing roller 5a is regulated to a predetermined thickness by the blade 5b. The developing roller 5a is a cylinder made of stainless steel or aluminum, and is supported by the frame of the developing device so as to be able to rotate and to ensure a regular distance from the photosensitive member, and a predetermined line of magnetic force is formed inside. A magnet is provided. An electrostatic latent image for each color formed on the surface of each photoconductor 2 by a laser beam to be described later is developed by a developing device 5 that handles toner of a predetermined color to become a visible image.

  An intermediate transfer unit 6 is disposed above the photoreceptors 2Y, 2C, 2M, and 2Bk. The roller 6b is driven and rotated so that the intermediate transfer belt 6a as an image carrier supported and stretched by a plurality of rollers 6b, 6c, 6d, and 6e travels in the direction of the arrow. The intermediate transfer belt 6a is endless, and is stretched and arranged so that a part of each photoconductor after the developing process comes into contact. Primary transfer rollers 7 </ b> Y, 7 </ b> C, 7 </ b> M, and 7 </ b> K are provided on the inner peripheral portion of the belt so as to face each photoconductor. A cleaning device 6h is provided on the outer peripheral portion of the intermediate transfer belt 6a at a position facing the roller 6e. The cleaning device 6h wipes off unnecessary toner remaining on the surface of the belt 6a and foreign matters such as paper dust. The roller 6e facing the cleaning device 6h includes a mechanism that applies tension to the intermediate transfer belt 6a. Although it always moves to ensure an appropriate belt tension, the opposing cleaning device 6h can also move in conjunction with it.

The intermediate transfer belt 6a is, for example, a belt based on a resin film or rubber having a base thickness of 50 to 600 μm, and applies a toner image carried by each photoreceptor 2 to the primary transfer roller 7. It has a resistance value that enables electrostatic transfer to the belt surface by the bias. The members related to the intermediate transfer belt 6 a are configured as the intermediate transfer unit 6 and can be attached to and detached from the image forming apparatus 100. As an embodiment of the intermediate transfer unit 6, the intermediate transfer belt 6 a is obtained by dispersing carbon in polyamide, and its volume resistance is adjusted to about 10 ⁶ to 10 ¹² Ωcm. Belt detent ribs for stabilizing the running of the belt are provided on one side or both ends of the belt.
In one embodiment of the primary transfer roller, the primary transfer roller 8 is a metal roller that is a core metal, and the surface of the metal roller is coated with a conductive rubber material, and a bias is applied to the core metal part from a power source (not shown). In the conductive rubber material, carbon is dispersed in urethane rubber, and the resistance is adjusted to a volume resistance of about 10 ⁵ Ωcm. A metal roller that does not have a rubber layer can also be used.

A secondary transfer roller 14a is provided on the outer periphery of the intermediate transfer belt 6a in the vicinity of the support roller 6b. The secondary transfer roller 14a is formed by coating the surface of a metal roller serving as a metal core with a conductive rubber, and a bias is applied to the metal core part from the power supply 14b. Carbon is dispersed in the rubber, and the volume resistance is adjusted to about 10 ⁷ Ωcm. A toner image carried on the intermediate transfer belt 6a is electrostatically transferred to the sheet S by applying a bias while passing a recording medium (hereinafter referred to as a sheet S) between the intermediate transfer belt 6a and the secondary transfer roller 14a. The
A plurality of, for example, two-stage sheet cassettes 9A and 9B are arranged below the exposure apparatus 8 so as to be able to be pulled out. The paper S stored in these paper feed cassettes 9A and 9B is selectively sent out by the rotation of the corresponding paper feed rollers 10A and 10B, and fed by the separating means 11A and 11B and the transport roller pair 12A and 12B. It is sent to the transport path P1. A pair of registration rollers 13 is provided in the paper feed conveyance path P <b> 1 in order to take a feed timing for sending the paper S to the secondary transfer unit 14. The sheet S is conveyed from the registration roller pair 13 toward the secondary transfer unit 14 including the intermediate transfer belt 6a and the secondary transfer roller 14a.

When not in use, the manual sheet feeder 25 provided on the right side of the figure can be rotated and stored in a part of the frame F of the image forming apparatus main body 100. The uppermost sheet S stored in the manual sheet feeding device 25 is fed by a sheet feeding roller 26 and separated by a separating unit (reverse roller) 27 so that only one sheet is reliably conveyed. , 24 through the conveying path P1 to the pair of registration rollers 13.
A fixing device 15 having a heating unit is provided above the secondary transfer unit 14. In this example, it is composed of rollers 15a and 15b with a built-in heater, but a type employing a belt and a heating method employing IH (electromagnetic induction heating) can be appropriately employed. The branching unit G1 is rotatable. In the state shown in the drawing, the sheet S after fixing is guided to the paper discharge path P3 and discharged to the paper discharge stack T at the top of the image forming apparatus 100 by the pair of paper discharge rollers 16. Stack paper.

The printer 100 in FIG. 1 includes a recording medium conveyance path and rollers for reversing and refeeding the paper S so that images can be automatically formed on both sides of the paper S. Specifically, a switchback path P5 and a refeed path P6 are provided inside the frame F, and the branching means G1 and G2 and the reversible means can be reversed so that the sheet on which image formation has been completed on one side is conveyed to the feed path P1. A roller 18a and a reversible roller 22 are provided. Rollers 23 and 24 are in contact with the reversible drive roller 22, and when the roller 22 rotates in the clockwise direction, the paper is conveyed from the manual paper feeder 25 in cooperation with the roller 24. When rotating clockwise, the sheet S is fed again in the direction of the registration roller 13 in cooperation with the roller 23.
When the branching unit G1 is rotated clockwise from the state shown in the drawing, the sheet having been fixed is guided to the transport path P4 by the roller pair 17, and is transported to the rollers 18a and 18b through the branching unit G2, and is temporarily switched back. It is sent to the road P5. As the roller 18a rotates counterclockwise and the branching means G2 rotates counterclockwise, the sheet S is sent to the refeed path P6. The paper conveyed by the roller pairs 15 c, 20 and 14 c, 21 is further conveyed to the roller pairs 22, 23 and reaches the registration roller pair 13.

The apparatus shown in FIG. 1 includes another sheet feeding device 50 at the bottom. In this example, the two paper feed cassettes 9C and 9D are provided. However, a type in which the number of paper feed cassettes is further increased can be adopted, and a type in which a paper feed cassette having a larger number of paper storages is incorporated may be used.
Above the fixing device, the third branching unit G3 downstream of the conveying direction of the roller pair 17 rotates counterclockwise from the state of FIG. 1, guides the sheet S after fixing, and conveys it to the paper discharge path P8. Thus, the paper S can be discharged to the bin tray 30 by the bin discharge roller 31.
An operation during single-sided printing in which an image is formed on one side of the paper P in such a configuration will be described. First, the laser beam 8Y corresponding to the image data for yellow emitted from the semiconductor laser by the operation of the exposure device 4 is irradiated onto the surface of the photoconductor 2Y uniformly charged by the charging roller 4aY, whereby the photoconductor 2Y. An electrostatic latent image is formed on the surface. This electrostatic latent image is developed with yellow toner after being developed by the developing roller 5aY, becomes a visible image, and has a transfer action by the primary transfer roller 7Y on the surface of the intermediate transfer belt 6a that moves in synchronization with the photoreceptor 2Y. Received and primary transferred. Such latent image formation, development, and primary transfer operations are performed in the same manner sequentially at the timings of the photoreceptors 2C, 2M, and 2Bk.
As a result, yellow Y, cyan C, magenta M, and black Bk toner images are carried on the surface of the intermediate transfer belt 6a as sequentially overlapping four-color toner images in the direction of the arrow together with the intermediate transfer belt 6a. Moved. On the other hand, the remaining toner and foreign matter are cleaned on the surface of the photoreceptor 2 by the cleaning device 3.

The four-color toner image formed on the intermediate transfer belt 6a is transferred onto the sheet S conveyed in synchronization with the intermediate transfer belt 6a by receiving a transfer action by the secondary transfer roller 14a. The surface of the intermediate transfer belt 6a is cleaned by a belt cleaning device 6h to prepare for the next image formation / transfer process. The sheet P on which the image has been transferred is subjected to a fixing action by the fixing device 15 and is discharged onto the sheet discharge stack T by the sheet discharge roller 16 with the image surface facing downward (face down).
An operation at the time of double-sided recording in which an image is formed on both sides of the paper S in such a configuration will be described. By the operation as described above, first, an image is transferred from the intermediate transfer belt 6a to one side of the paper SP, and the paper S that has passed through the fixing device 15 is guided toward the roller pair 17 by the first branching means G1. The sheet S traveling above the second branching means G2 at the rotation position in FIG. 1 through the third branching means and the transporting path P4 provided downstream of the transporting path of the roller pair 17 is transferred to the transporting path P5 by the roller 18a. 18b, the reversible drive roller 18a rotates in the clockwise direction. The roller pair 19 is also a roller capable of forward / reverse rotation, and once the paper is received in the switchback transport path P5, it is reversely rotated to reversely feed the paper. At that time, the second branching means G2 rotates counterclockwise from the posture shown in the drawing, and the pair of rollers 15c, 20 and 14c, 21 is directed toward the transport path P4 with the former rear end as the leading end. Transport. After that, the registration roller pair 13 is reached as described above. The toner on the intermediate transfer belt 6a is conveyed by transporting the sheet S having an image on one side again toward the secondary transfer portion 14 having the secondary transfer roller 14a at the timing of the registration roller pair 13. The image is transferred to the other side of the paper S.

Images to be formed on the second surface of the paper are sequentially formed by an image forming process that is started when the paper S is conveyed to a predetermined position. The image forming process in this case is also the same as the above-described full-color toner image formation during single-sided printing, and this full-color toner image is carried on the intermediate transfer belt 6a. However, since the front and back of the sheet S are reversed in the transport path P5, the image data emitted from the exposure device 8 is created so that the image is formed in the reverse direction in the sheet transport direction compared to the first image formed. Is controlled and executed.
The sheet S on which the full-color toner images are transferred on both sides in this way is again discharged onto the discharge stack portion T by the discharge roller 16 after undergoing fixing processing by the fixing device 15. In order to increase the efficiency of double-sided image formation, several sheets of paper can be simultaneously conveyed along the conveyance path. The formation timing of the images to be formed on the front and back of the paper is executed by a control means (not shown).
Incidentally, in the present embodiment, the polarity of the toner image formed on the photosensitive member 2 is negative, and by applying a positive charge to the primary transfer roller 7, the toner image on the photosensitive member 2 is transferred to the intermediate transfer belt 6a. Transferred to the surface. Further, the toner image on the surface of the intermediate transfer belt 6a is transferred onto the sheet S by applying a positive charge to the secondary transfer roller 14a.

The single-sided printing operation and the double-sided printing operation have been described with reference to an example in which full-color printing is performed. However, there are photosensitive members that are not used during black-and-white monochrome printing. In addition to not operating the unused photoreceptors 2Y, 2C, 2M or developing devices 5Y, 5C, 5M, a mechanism is provided for keeping these unused photoreceptors and the intermediate transfer belt 6a in non-contact. In this embodiment, the inner frame 6f that supports the roller 6d and the primary transfer rollers 7Y, 7C, and 7M is supported so as to be rotatable about the shaft 6g, and is rotated in a direction away from the photoreceptor (clockwise in FIG. 1). By moving, only the photosensitive member 2Bk comes into contact with the intermediate transfer belt 6a, and an image forming process is executed, thereby creating a monochrome image using black toner. This is advantageous in terms of improving the service life.
When maintenance or parts replacement is required, maintenance is performed by opening an exterior cover (not shown), etc., but the members constituting the image forming unit 1 shown in FIG. It is convenient to exchange. When the image forming unit 1 shown in FIG. 2 is configured as a process cartridge, a guide unit and a handle for mounting on the printer 100 are provided to facilitate attachment and detachment. In addition, it is convenient to provide a storage device (for example, an IC tag) for storing the characteristics and operation status of the process cartridge, which is a guideline for maintenance. Further, when the maintenance or replacement of the intermediate transfer belt unit 6 is performed, the intermediate transfer belt unit 6 can be pulled out by separating the intermediate transfer belt 6a from the photoreceptors 2Y, 2M, 2C, and 2Bk.

FIG. 3 shows the transport paths of P1, P2, P4, P6, and P7 in order to easily remove the jammed paper S when the paper S is jammed in the transport paths P1 to P8. FIG. 3 is a partial view showing a state in which a frame F is opened from the state 1;
As shown in FIG. 3, the frame F is rotated clockwise with the lower rotation axis Fa as the rotation center so that the upper part of the apparatus main body can be opened. Prior to opening, most of the transport paths can be opened by opening a lock lever (not shown), so that jammed paper can be easily treated. The frame F is provided with a secondary transfer device 14 and a reversing guide member 32 to be described later, and has one guide surface P7a, P1a, P2a, P9a of the transport paths P7, P1, P2, and P9. With the opening operation of the frame F, the secondary transfer device 14, the reversing guide member 32 described later, and the guide surfaces P7a, P1a, P2a, and P9a rotate together with the frame F, and the guide surfaces P7a, P1a, P2a, and P9a are rotated. The conveyance paths P7, P1, P2, and P9 are opened apart from the other guide surfaces P7b, P1b, P2b, and P9b of the conveyance paths P7, P1, P2, and P9 attached to the main body device. Further, the secondary transfer device 14 in which the transport paths P2 and P6 are formed on both sides has the center of the roller 23 as the center of rotation, and when the frame F is opened as shown in FIG. The secondary transfer device 14 is given a turning habit so that it is separated from the belt 6a and the roller 14c is separated from the roller 21. The secondary transfer device 14 includes a power source 14b inside, and the outside of the case forms a guide surface having a function of transporting the paper S. The fixing device 15 also has a conveyance roller 15c and a conveyance guide surface P6b, and a part thereof constitutes a conveyance path P6.

In the present embodiment, in order to facilitate the removal of the paper S jammed in the transport paths P4, P5, P6, and P8 when a paper jam occurs in the transport paths P4, P5, P6, and P8, FIG. As shown in FIG. 4, the reversing guide member 32 is rotatably mounted on the support shaft 33, and the reversing guide member 32 is rotated counterclockwise so that the upper portions of the transport paths P4 and P6 can be opened.
As shown in FIG. 4, the reversing guide member 32 feeds the paper S fed from the transport path P2 and having the image fixed by the fixing device 15 to the transport path P8 (second transport path) or the transport path P4 (third transport). The guide surface P9a (second guide surface) of the transport path P9 (first transport path), the one roller 17a of the transport roller pair 17, the branching means G3, and the transport path P4 (third). A guide surface P4a (first guide surface) of the transport path) and a guide surface P61a (fourth guide surface) of the upper transport path P61 of the transport path P6. Then, as will be described later, when the user presses the operation surface 34c of the handle portion 34 with a finger, as shown by a dotted line, the user rotates the support shaft 33 in the direction of the arrow A as shown in the dotted line, thereby conveying paths P4 and P61. Can be opened. In the present embodiment, the reversing guide member 32 includes the roller 17a. However, the roller 17a is not necessarily required and may not include the roller 17a. Further, the reversing guide member 32 has a side plate portion 32a, such as a rotation angle restricting member (not shown) that restricts the turning angle of the reversing guide member 32, a click structure that holds the reversing guide member 32 in a closed state, and the like. A reversing guide member holding means is provided.

  As shown in FIG. 5, the branching means G3 attached to the upper side of the reverse guide member 32 opposite to the support shaft 33 is supported by a bearing portion 32b formed at the upper end of the side plate portion 32a of the reverse guide member 32. A plurality of triangular rib-shaped switching claws G3b attached to the rotation shaft G3a at a predetermined interval are provided. The switching claw G3b rotates the rotation axis G3a in the direction of arrow B by a rotation means (not shown) to change the conveyance direction of the paper S from the conveyance path P9 (first conveyance path) to the conveyance path P8 (second conveyance path) or Switching to the transport path P4 (third transport path) is possible. Specifically, when the rotation shaft G3a is rotated clockwise, the switching claw G3b prevents the sheet S from entering the conveyance path P8 and allows entry into the conveyance path P4. On the other hand, when the rotation shaft G3a is rotated counterclockwise, the conveyance path P4 is closed and the paper S is allowed to enter the conveyance path P8. And the notch 32b is formed in the upper end of the guide surface P9a of the inversion guide member 32, The front-end | tip G3b1 of the switching claw G3b is inserted in this notch 32b, and it is reliably on the guide surface G3b2 of the switching claw G3b. The paper S can be guided.

  Further, in the present embodiment, as shown in FIG. 5, a handle portion 34 is attached to a part of the separation portion 36 of the switching claw G3b, and the user operates the operation surface 34c of the handle portion 34 with the finger in the direction of arrow C. The reversing guide member 32 is easily rotated in the direction of the arrow A by pressing to make it possible to open the transport paths P4 and P61. As described above, since the handle portion 34 is formed in the separation portion 36 of the switching claw G3b, the operation surface 34c of the handle portion 34 is easily and reliably pressed in the C direction without affecting the operation of the switching claw. The reversing guide member 32 can be rotated. The handle portion 34 is molded of plastic resin, and as shown in FIGS. 6 and 7, a root portion 34a serving as a rotation shaft attachment portion is fitted to the rotation shaft G3a. In this case, in order to easily fit the root portion 34a to the rotation shaft G3a, the root portion 34a has a cut-out C-shape having a notch 34a1 partially cut away in the circumferential direction of the rotation shaft G3a. It has a shape. Therefore, if the root portion 34a of the handle portion 34 is pressed against the rotation shaft G3a from the notch portion 34a1, the root portion 34a can be easily press-fitted and fitted to the rotation shaft G3a. Incidentally, for example, if the inner diameter of the root portion 34a is set to 3 mm with respect to the rotation shaft G3a having a shaft diameter of 4 mm, an appropriate click interval can be obtained during assembly, and it will not come off during user operation.

Further, locking portions 34b1 and 34b2 are formed at the side ends of the handle portion 34 so as to be locked to the protruding portions G3c1 and G3c2 protruding from the side surface of the switching claw G3b. The protruding portions G3c1 and G3c2 When the operating surface 34c by the finger 35 is pressed in the C direction by locking the 34b1 and 34b2, the pressing force by the finger 35 can be reliably transmitted to the reverse guide member 32. Further, in order to prevent the movement of the handle portion 34, the locking portions 34b1 and 34b2 are formed with step portions 34b1a. The leading ends of the step portions 34b1a and the protruding portions G3c1 and the leading ends of the locking portions 34b2 The side surface G3c of the switching claw is brought into contact with the switching claw so as to prevent movement in the direction of the rotation axis G3a. In this case, if the handle portion 34 is curved and abutted while elastically deforming the central portion, the operation surface 34c that abuts on the finger becomes a concave surface, and the finger can be smoothly pressed. Further, the surface 34d opposite to the operation surface 34c is a protruding surface and can be used as a guide surface when the paper S is conveyed.
Moreover, the handle part 34 is formed in a different color from the switching claw G3b, so that the user can easily recognize that it is a handle.

In this way, the handle portion 34 is inserted into the separation portion 36 of the switching claw G3b from above, the root portion 34a is fitted to the rotation shaft G3a, and the locking portions 34b1 and 34b2 are locked to the protruding portions G3c1 and G3c2. Thus, the handle portion 34 can be easily attached to the separated portion of the switching claw G3b. The handle portion 34 attached in this manner easily and surely rotates the reverse guide member 32 by pressing the operation surface 34c of the handle portion 34 in the C direction to open the transport paths P4 and P61. The jammed paper S can be removed.
In the above embodiment, the root portion 34a that fits the rotation shaft G3a is formed on the handle portion 34. However, only the locking portions 34b1 and 34b2 are provided without forming such a root portion 34a. Even if the stoppers 34b1, 34b2 and the projections G3c1, G3c2 of the switching claw G3b are locked, the reversing guide member 32 is easily and reliably rotated by pressing the operation surface 34c of the handle 34 in the C direction. It is possible. On the contrary, the same operation and effect can be obtained even when the handle portion 34 is fixed to the rotation shaft G3a by the root portion 34a without forming the locking portions 34b1 and 34b2.

In the above embodiment, the handle portion 34 is formed separately from the switching claw G3b. However, even if the switching claw is also formed of plastic resin, the handle portion 34 and the switching claw G3b are integrally formed. Good. In this case, it is possible to easily confirm the position of the handle portion 34 by forming the handle portion 34 and the switching claw G3b in two different colors.
Furthermore, in the said embodiment, although the handle part 34 was formed in the one separation part 36 of the switching claw G3b, it is also possible to form in the several separation part 36 or all the separation parts 36. FIG.
As described above, in the recording medium conveyance structure of the present embodiment, the support shaft 33 as the guide member 32 having the second guide surface P9a and the first guide surface P4a that respectively form the first conveyance path and the third conveyance path. On the opposite side, the branching means G3 with the plurality of switching claws G3b attached to the rotating shaft G3a is attached, and the handle portion 34 is attached to the separation portion 36 of the switching claw G3b. The reversing guide member 32 can be easily and reliably rotated by pressing the operation surface 34c of the handle portion 34 in the C direction.

Further, the reversing guide member 34 of the present embodiment has a conveyance path P9 that conveys and guides the sheet S having the image formed on the surface by the image forming units 1Y, 1C, 1M, and 1Bk and fixed by the fixing device 15. A transport route that transports and guides the transport path P8 that discharges the paper S from the transport path P9 as a second transport path, and a hatchback path P5 or a refeed path P6 that reversely transports the paper S as a third transport path. A path P4 is provided, and a branching unit G3 that branches the paper S from the first transport path to the second transport path or the third transport path is provided. Therefore, the branching unit G3 is also rotated with the rotation of the reversing guide member 34 and the upper part thereof is opened, so that the sheet S jammed in the branching unit G3 and the conveyance path P4 can be easily removed.
Further, the reversing guide member 34 of the present embodiment has a guide surface P9a of the transport path P9 as the first transport path as the second guide surface, and the guide surface formed on the apparatus main body facing the guide surface P9a. It is rotatably attached to a frame F (second guide member) that is attached to P9b (third guide surface) so as to be opened and closed. Accordingly, the frame F is opened to form a large space around the reversing guide member 34, and the reversing guide member 34 is rotated in this space. It is possible to carry it.
Note that the recording medium conveyance path structure of the present embodiment is applied to a printer as an image forming apparatus, but is similarly applicable to an image forming apparatus such as an electrophotographic copying machine and a facsimile.

1 is a cross-sectional view illustrating a schematic configuration of an image forming apparatus according to an embodiment of the present invention. FIG. 2 is a cross-sectional view illustrating a schematic configuration of an image forming unit of the image forming apparatus illustrated in FIG. 1. FIG. 2 is a partial view showing a state where a frame F of a duplex unit is opened from the state of FIG. 1. It is the fragmentary figure which expanded the inversion guide member part of FIG. 1 is a perspective view illustrating a schematic configuration of a recording medium conveyance path structure according to an embodiment of the present invention. It is sectional drawing cut | disconnected on the AA line of FIG. It is sectional drawing cut | disconnected on the BB line of FIG.

Explanation of symbols

1Y, 1C, 1M, 1Bk Image forming unit, 2Y, 2C, 2M, 2Bk photoconductor, 3aY cleaning brush, 3bY cleaning blade, 4aY charging roller, 5Y developing device, 6 intermediate transfer unit, 6a intermediate transfer belt, 7Y, 7C 7M, 7Bk Primary transfer roller, 8 Exposure device, 9A, 9B, 9C, 9D Paper cassette, 10A, 10B, 10C, 10D Paper feed roller, 11A, 11B, 11C, 11D Separating means, 12A, 12B, 12C, 12D conveying roller pair, 13 registration roller, 14 secondary transfer device, 15 fixing device, 17, 17a, 17b conveying roller, 32 reverse guide member, 32a side plate, 32b bearing portion, 33 spindle, 34 handle portion, 34a root portion , 34b1, 34b2, locking part, 34c operation surface, 36 separation part, 4 transport path (third transport path), P8 transport path (second transport path), P9 transport path (first transport path), P4a guide surface (first guide surface), P9a guide surface (second guide surface), P9b guide surface (third guide surface), G3 branching means, G3a rotation shaft, G3b switching claw, G3c side surface, G3c1, G3c2 protrusion

Claims (11)

To switch the conveyance path of the recording medium at the branch position of the first conveyance path, the second conveyance path and the third conveyance path branched from the first conveyance path, and the second conveyance path and the third conveyance path. Branching means, and a guide member having a guide surface that respectively forms the first transport path and the third transport path, and the guide member is rotatably attached at one end by a support shaft. In the recording medium transport path structure in which the third transport path is opened by rotation of
The guide member includes the branching unit on the opposite side of the support shaft, and the branching unit is mounted on the rotating shaft with a plurality of switching claws spaced apart from each other. A recording medium conveyance path structure, wherein a handle portion for manually rotating the guide member is attached to at least one separated portion. In the recording medium conveyance path structure according to claim 1,
The first transport path is a path for transporting a recording medium on which an image is formed on one side, and the third transport path is a transport path for a recording medium for reversing the recording medium on which the image is formed on the one side. A recording medium conveyance path structure characterized by the following. In the recording medium conveyance path structure according to claim 1 or 2,
The guide member has a second guide surface that forms the first transport path, and the second guide surface is attached to the third guide surface facing the first transport path so as to be opened and closed. A recording medium conveyance path structure, wherein the recording medium conveyance path structure is rotatably attached to a member. The recording medium conveyance path structure according to any one of claims 1 to 3,
The recording medium transport path structure according to claim 1, wherein the handle portion is attached to a rotation shaft of a separation portion of the plurality of switching claws at a base portion. In the recording medium conveyance path structure according to claim 4,
The rotating shaft mounting portion of the handle portion has a cutout portion cut out in a circumferential direction that allows insertion of the rotating shaft. The recording medium transport path structure according to any one of claims 1 to 5,
A recording medium conveyance path structure, wherein a conveyance guide surface of the recording medium is formed on a surface opposite to a manual operation surface of the handle. The recording medium conveyance path structure according to any one of claims 1 to 6,
The recording medium transport path structure, wherein the handle is formed in a different color from the switching claw. The recording medium conveyance path structure according to any one of claims 1 to 7,
The recording medium conveyance path structure, wherein the handle portion is made of a plastic resin. The recording medium conveyance path structure according to claim 8,
The recording medium transport path structure, wherein the handle is formed integrally with the switching claw. An image forming unit that forms an image on a recording medium, a first conveying path that conveys a recording medium on which an image is formed by the image forming unit, a second conveying path that branches off from the first conveying path, and a third A branching means for switching the transport path of the recording medium at a branch position of the transport path, the second transport path, and the third transport path; and a guide surface that forms the first transport path and the third transport path. An image forming unit including a recording medium conveyance path structure in which one end of the guide member is rotatably attached to a support shaft and the third conveyance path is opened by the rotation of the guide member. In the device
The image forming apparatus according to claim 1, wherein the recording medium transport path structure is the recording medium transport path structure according to claim 1. The image forming apparatus according to claim 10.
The image forming apparatus is an electrophotographic copying machine, a laser beam printer, or a facsimile apparatus.

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