JP4831249B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus.

  In a general electrophotographic image forming apparatus represented by a copying machine or a laser printer, an unfixed toner image is held on a paper in an image forming process, and the toner image held on the paper in a fixing process is heated and fixed. is doing. Then, the paper on which the toner image is fixed is discharged to the outside in the discharge process. As a discharge device used in the discharge process, there is a discharge device in which a conveyance driven roller is brought into pressure contact with a conveyance drive roller and a sheet is sandwiched and discharged at a nip portion between the conveyance drive roller and the conveyance driven roller (see Patent Document 1). ). In Patent Document 1, as shown in FIG. 10, the biasing force of the torsion coil spring 104 is used to press the transport driven roller 102 against the transport drive roller 100. The torsion coil spring 104 has one end side (frame hooking end 104b) hooked to the hook-shaped hook portion 106A of the transport unit frame 106, and the coil portion 104a is fitted to the coil holding portion 106B of the transport unit frame 106. The other end side (holder engaging end 104 </ b> C) is in contact with the transport driven roller holder 108. Thereby, the torsion coil spring 104 urges the conveyance driven roller 102 via the conveyance driven roller holder 108.

JP 2003-63685 A

  An object of the present invention is to provide an image forming apparatus that simplifies the mounting operation of a spring that biases a driven rotating member.

An image forming apparatus according to a first aspect of the present invention includes an image forming unit that forms an unfixed toner image on a sheet, a fixing unit that heat-fixes the toner image formed on the sheet, and a rotating driving rotating member. A driven rotating member that rotates in contact with the sheet, conveys the sheet fed from the fixing unit together with the driving rotating member, and discharges the sheet to the outside. The driven rotating member is urged to rotate the driven rotating member. A spring that is in pressure contact with the driving rotation member, and a conveyance path member that is provided between the fixing unit and the driven rotation member and guides the sheet fed from the fixing unit and accommodates a part of the spring. And a conveyance path that is attached to the upstream side of the conveyance path member in the sheet conveyance direction and has a cover that covers the accommodation section, and guides the sheet between the drive rotation member and the driven rotation member. peeling Guy to configure When provided the driven rotary member provided in the sheet conveyance direction downstream side of the peeling guide the transport path member so as to sandwich the both axial sides of the driven rotary member, a first rib for guiding the sheet, A second rib provided on the surface of the cover portion, extending toward the driven rotation member sandwiched between the first ribs, and guiding paper between the drive rotation member and the driven rotation member; Have

In the image forming apparatus according to claim 2 of the present invention, the spring is formed by bending a wire or a plate, and a spring receiving portion provided on one of the bent portions is accommodated in the accommodating portion. A support portion provided on the other side rotatably supports the driven rotation member.

  According to the first aspect of the present invention, the mounting operation of the spring for urging the driven rotating member is simplified as compared with the case where this configuration is not provided.

The invention of claim 2 makes it easier to attach the driven rotating member as compared with the case where the present configuration is not provided.

1 is a diagram illustrating an overall configuration of an image forming apparatus according to a first embodiment. 2 is an enlarged partial cross-sectional view of the periphery of the fixing device of the image forming apparatus according to the first embodiment. FIG. FIG. 3 is a partial cross-sectional perspective view of the fixing device of the first embodiment as viewed obliquely from above. It is explanatory drawing of the attachment procedure for attaching a peeling guide, a pinch roller, etc. to the housing of a fixing device. It is the perspective view which looked at the one end part side of the peeling guide attached to the fixing apparatus from diagonally upward. It is the perspective view which looked at the other end part side of the peeling guide attached to the fixing device from diagonally upward. It is the perspective view which looked at the state which attached the pinch roller to the accommodating part of the image forming apparatus from diagonally upward. It is explanatory drawing of the accommodation procedure for accommodating a pinch roller in the accommodating part of an image forming apparatus. It is a perspective view which shows the leaf | plate spring which is a modification of the spring of 1st Embodiment. It is a fragmentary sectional view which shows the conventional spring mounting structure of the torsion coil spring which urges | biases a driven rotation member and press-contacts to a drive rotation member.

(First embodiment)
Hereinafter, a first embodiment of an image forming apparatus according to the present invention will be described in detail with reference to the drawings.

  As shown in FIG. 1, the image forming apparatus 10 includes sheet feed trays 14 and 15 in which sheets P are stacked and stored in a bundle at the bottom, and print discharged from the sheet discharge port 40 to the outside at the top. The image forming unit 11 includes a paper discharge unit 20 on which the (image-formed) paper P is placed. The image forming unit 11 forms an image on the paper P between the paper feed trays 14 and 15 and the paper discharge unit 20. A control unit 12 that controls the operation and a power supply unit 13 are provided. Further, the image forming apparatus 10 includes a plurality of conveyance rollers for guiding and conveying the paper P in each image forming process of the apparatus, and a plurality of conveyance rollers for nipping and conveying the paper P provided in the paper conveyance path. Note that an arrow U in the drawing indicates an upward direction of the image forming apparatus 10, an arrow F indicates a forward direction, and an arrow H indicates a horizontal direction.

  The image forming apparatus 10 includes a first paper feed conveyance path 80 that gently curves from the front end side (front side of the apparatus) of the paper feed tray 14 toward the front of the apparatus, and the front end side of the paper feed tray 15 (see FIG. In FIG. 1, a second paper feed conveyance path 82 that is gently curved from the front side of the apparatus toward the upper front side of the apparatus is provided. These paper feed conveyance paths merge before (downward) the pair of registration rollers 24 provided above the paper feed tray 14.

  A cover 10A is attached to the front side of the image forming apparatus 10 so that the cover 10A can be opened and closed with a hinge 10B provided on the lower side of the apparatus as a rotation axis. A manual feed tray 10C having the same rotation axis as that of the hinge 10B described above is provided on the front surface of the cover 10A. When the manual feed tray 10C is opened, an input port 21 for paper P provided in the cover 10A appears. It is like that. The insertion port 21 serves as an inlet of a third paper feed conveyance path 84 provided in the image forming apparatus 10, and the third paper feed conveyance path 84 is gradually inclined obliquely upward from the input port 21 to the rear of the apparatus. Is curved.

  A paper feed roller 16 is provided immediately above the front end side of the paper feed tray 14 so as to press-contact the front end side of the upper surface of the paper P. The paper feed roller 16 is in pressure contact with the paper feed roller 16 in front of the paper feed roller 16. A separation roller 18 is provided. The paper feed roller 16 picks up the paper P at the top of the paper feed tray 14 and feeds the paper P to the first paper feed path 80 through the separation roller 18. Further, the separation roller 18 is configured to pick up the paper P picked up by the paper supply roller 16 (whether it is picked up (separated) when a plurality of sheets are picked up).

  Similarly, a paper feed roller 17 is provided immediately above the front end side of the paper feed tray 15 so as to press-contact the front end side of the upper surface of the paper P. The paper feed roller 17 is located on the front side of the apparatus with respect to the paper feed roller 17. A separation roller 19 is provided in pressure contact therewith. The paper feed roller 17 picks up the paper P at the top of the paper feed tray 15 and sends the paper P to the second paper feed conveyance path 82 through the separation roller 19. Further, the separation roller 19 is configured to pick up the paper P picked up by the paper supply roller 17 (when picking up a plurality of sheets, it is picked up (separated)).

  Note that a pair of registration rollers 25 are provided on the second paper feed conveyance path 82, and the registration rollers 25 sandwich and convey the paper P sent to the second paper feed conveyance path 82. It is designed to be sent to the side.

  Further, the image forming apparatus 10 is provided with an image forming conveyance path 86 for guiding the sheet P sent out from the registration roller 24 toward a fixing device 200 (to be described later) of the image forming unit 11. The conveyance path 86 extends substantially linearly from the registration roller 24 to the upper fixing device 200.

  The image forming conveyance path 86 is provided with an endless conveyance belt 26 that electrostatically attracts the sheet P and conveys the sheet P to the fixing device 200. The conveyor belt 26 is stretched between a stretching roller 27 disposed above and a stretching roller 29 disposed below, and one of the stretching roller 27 and the stretching roller 29 is in a predetermined direction (see FIG. 1, the conveyance belt 26 is rotated (circulated) in a predetermined direction (counterclockwise direction in FIG. 1) by being driven to rotate in the counterclockwise direction.

  On the upstream side of the image forming conveyance path 86 of the conveyance belt 26 (sometimes simply referred to as “upstream side”), the surface of the conveyance belt 26 is charged and the sheet P electrostatically attracted to the conveyance belt 26 is conveyed. A charging roller 31 that presses against the belt 26 is provided adjacent to the transport belt 26.

  In addition, a plurality of process cartridges 28Y, 28M, 28C, and 28K corresponding to the respective colors of yellow, magenta, cyan, and black are formed at the position facing the conveyance belt 26 with the image formation conveyance path 86 therebetween. Along the conveyance path 86, a column is arranged in a substantially vertical direction. The image forming unit 11 includes process cartridges 28Y, 28M, 28C, and 28K, a transfer device 39 and a fixing device 200 described later.

  Each process cartridge 28Y, 28M, 28C, 28K is provided with a photosensitive drum 30 that rotates in a predetermined direction (clockwise in FIG. 1). Around the photosensitive drum 30, a charging roller 32 as a charging device that uniformly charges the surface of the photosensitive drum 30 in order from the upstream side in the rotation direction of the photosensitive drum 30, and a charged photosensitive drum 30. And an exposure device 34 that forms an electrostatic latent image on the photosensitive drum 30 by exposing the toner, and development as a developing device that develops toner by attaching each color toner to the electrostatic latent image formed on the photosensitive drum 30. A roller 36, a neutralizing brush 37 serving as a neutralizing device that neutralizes the photosensitive drum 30 after transfer, and a cleaning blade 38 serving as a cleaning device that removes toner remaining on the surface of the neutralized photosensitive drum 30 are provided. It has been. The toner removed from the surface of the photosensitive drum 30 by the cleaning blade 38 is conveyed to one side by the auger 35 and discharged to a toner collection box (not shown).

  The charging roller 32 and the developing roller 36 are provided in each of the process cartridges 28Y, 28M, 28C, and 28K. Although not shown, each process cartridge 28Y, 28M, 28C, 28K is detachable in the left direction (front of the apparatus).

  Specifically, the exposure device 34 includes a semiconductor laser, a polygon mirror, an imaging lens, and a mirror disposed in a housing, and light from the semiconductor laser is deflected and scanned by the polygon mirror, The photosensitive drum 30 is irradiated through a mirror. As a result, an electrostatic latent image corresponding to the image information is formed on the photosensitive drum 30.

  A transfer device 39 for transferring the toner image formed on the photosensitive drum 30 to the paper P at a predetermined transfer position is provided on the inner peripheral side of the conveyance belt 26 in the forward direction of the photosensitive drum 30.

  A fixing device 200 as a fixing unit that fixes the transferred toner image onto the paper P is provided on the downstream side of the image forming conveyance path 86 (sometimes simply referred to as “downstream side”). The fixing device 200 includes a heating roller 62 and a pressure roller 64 that is pressed against the heating roller 62, and a sheet P is placed in a nip portion 66 formed between the heating roller 62 and the pressure roller 64. By passing the toner image, the toner image on which the toner on the paper P is melted and transferred (unfixed toner image) is fixed.

  Further, the image forming apparatus 10 is provided with a first paper transport path 88 for guiding the paper P fixed by the fixing device 200 to the paper discharge port 40. The paper discharge port 40 has a discharge roller 210 as a drive rotation member that rotates using a drive motor 41 that can be rotated forward or reverse as a drive source, and a pinch roller as a driven rotation member that is pressed against the lower surface side of the discharge roller 210. 214 is provided. The pinch roller 214 is in pressure contact with the discharge roller 210 by the urging force of a torsion coil spring 240 (see FIG. 2) provided below the pinch roller 214, and rotates with the discharge roller 210. . Thus, when printing (image formation) is completed, the paper P passes through the first paper conveyance path 88 and is nipped and conveyed by the discharge roller 210 and the pinch roller 214 and is discharged from the paper discharge port 40 to the paper discharge unit 20. .

  In addition, a paper sensor (not shown) is provided in front of the paper discharge port 40 so as to detect the presence or absence of the paper P at the paper discharge port 40.

  In the case of duplex printing, the paper P on which an image is formed on one side is nipped and conveyed by the discharge roller 210 and the pinch roller 214, and the rear end portion of the paper P is close to the nip portion of the discharge roller 210 and the pinch roller 214. The discharge roller 210 is reversely rotated (specifically, the drive motor is reversely rotated), and the paper P is fed back from the rear end portion to a second paper conveyance path 90 described later. The discharge roller 210 uses the timing of reversal when the detection of the paper P by the paper sensor is changed from being present to absent. Note that the reverse rotation timing of the discharge roller is not limited to this configuration, and may be determined based on the size of the paper P being conveyed and the conveyance speed.

  The above-described second sheet conveyance path 90 is provided in the image forming apparatus 10, extends above the first sheet conveyance path 88, and extends forward of the apparatus, and below the image formation conveyance path 86 through the apparatus front side. And joins the third paper feed conveyance path 84 on the way.

  In the second paper conveyance path 90, a plurality of (for example, two) pairs of conveyance rollers 48 for nipping and conveying the paper P downward are disposed. In the case of duplex printing, the paper P on which an image is formed on one side. Is guided to the second paper conveyance path 90, conveyed downward by a plurality of conveyance rollers 48, and sent back to the registration rollers 24.

  Next, the fixing device 200 will be specifically described. As shown in FIGS. 3 and 4, the fixing device 200 has a housing 202. The housing 202 includes a side wall portion 202A attached to one inner wall surface (not shown) in the left-right direction of the image forming apparatus 10, a side wall portion 202B attached to the other inner wall surface (not shown), the side wall portion 202A and the side wall. It is comprised by the connection part 202C which connects the lower part side with the part 202B. An upper surface 202D of the connecting portion 202C is positioned above the heating roller 62, and a conveyance path member 206, which will be described later, is attached to the rear side of the upper surface 202D in the apparatus left-right direction. Further, a guide mounting portion 204 for attaching a peeling guide 220 to be described later with a standing wall 206A on the front side of the conveying path member 206, an upper surface 202D of the connecting portion 202C, and inner wall surfaces of the side wall portion 202A and the side wall portion 202B. Is formed (configured). Further, the heating roller 62, the pressure roller 64, and the discharge roller 210 described above are rotatably supported on the side wall portion 202A and the side wall portion 202B.

As shown in FIGS. 2 and 3, the peeling guide 220 has a substantially triangular shape when viewed from the side (viewed from the left-right direction of the apparatus) and is attached to the guide attachment portion 204 of the housing 202. The leading end 220 </ b> A of the peeling guide 220 is close to the heating roller 62, and the sheet P after being heated and fixed is peeled from the heating roller 62. Further, a plurality of ribs 222 extending along the first paper conveyance path 88 are provided on the surface of the peeling guide 220 (the front surface of the apparatus) in parallel with the axial direction of the heating roller 62 (that is, the apparatus left-right direction). The surface of the rib 222 forms the conveyance path surface 220 </ b> B of the first sheet conveyance path 88. The ribs 222 reduce the contact area between the sheet P passing through the first sheet conveyance path 88 and the conveyance path surface 220B of the peeling guide 220, so that the frictional resistance is reduced and the sheet P passes through the first sheet conveyance path 88. It will flow smoothly .

  Further, as shown in FIGS. 3 and 4, the peeling guide 220 is provided with a stopper 224 as a cover portion that covers an accommodation recess 230 described later. The stopper 224 is a plate material and projects from the upper end portion of the rear wall surface of the peeling guide 220 to the discharge roller 210 side. Further, the rib 222 described above is extended on the surface of the stopper 224, and a rib 222A is formed as a convex portion whose surface forms the transport path surface of the paper transport path.

  As shown in FIGS. 3 and 4, the longitudinal direction of the peeling guide 220 is the left-right direction of the apparatus. A columnar protrusion 225 protrudes from one wall surface (left wall surface as viewed from the front of the apparatus) in the longitudinal direction of the peeling guide 220, and a columnar protrusion 226 protrudes from the other wall surface. Further, a columnar protrusion 227 and a columnar protrusion 228 protrude from the rear wall surface of the peeling guide 220 across the center line of the peeling guide 220. Further, a boss 229 is formed between the protrusion 227 and the protrusion 228 on the rear wall surface of the peeling guide 220, and a screw 256 penetrating through a hole 255 described later is screwed.

  As shown in FIGS. 3 to 6, the peeling guide 220 is attached to the guide attaching portion 204. Specifically, a hole 251 is provided in one wall surface (the inner wall surface of the side wall portion 202A) forming the guide mounting portion 204, and the protrusion 225 of the peeling guide 220 is fitted into the hole 251 ( (See FIG. 5). In addition, a U-shaped groove 252 that is open on the front side of the apparatus is formed on the other wall surface (the inner wall surface of the side wall portion 202B) that forms the guide mounting portion 204. It is fitted from the side (see FIG. 6). In addition, holes 253 and 254 are provided in the standing wall 206A of the conveyance path member 206 forming the guide attaching portion 204, and the protrusions 227 and 228 of the peeling guide 220 are fitted into these holes 253 and 254, respectively. . Further, a hole 255 is provided at a position corresponding to the boss 229 of the peeling guide 220 in the standing wall 206 </ b> A of the conveyance path member 206, and the screw 256 is screwed into the female screw of the boss 229 through the hole 255. In this way, the peeling guide 220 is attached to the housing 202.

  As shown in FIG. 3, a rib 208 extending toward the discharge roller 210 is provided on the upper surface of the transport path member 206. A plurality of ribs 208 are arranged in parallel in the left-right direction of the apparatus. Further, the ribs 208 enter between the ribs 222 of the peeling guide 220 when viewed from the front (viewed from the front of the apparatus), and the surface formed by the surface of the ribs 222 and the surface of the ribs 208 is the same when viewed from the side. It has become.

  As shown in FIG. 4, an accommodation recess 230 is provided between the ribs 208 on the upper surface of the transport path member 206. In the receiving recesses 230, spring receiving portions 248 of the torsion coil spring 240 described later are respectively received. At the center of the housing recess 230, a rib 208A is provided standing from the bottom surface 230A. The ribs 208A are on an extension line of the ribs 222A of the peeling guide 220, are arranged in a straight line when viewed from the front, and the surface created by the surface when viewed from the side is flush. Further, as shown in FIG. 7, a notch 208B is formed on the rear side of the rib 208A, and a notch 208B has a connecting portion 248C of a spring receiving portion 248 of a torsion coil spring 240 described later. Has entered.

  As shown in FIGS. 4 and 8, the housing recess 230 includes a pair of guide support members 232 provided upright on the bottom surface 230A on both sides of the rib 208A. When viewed from the front side of the apparatus, the right side surface of the right guide support member 232 is integrated with the left wall surface of the right rib 208 forming the accommodation recess 230, and the left side surface of the left guide support member 232 is accommodated. It is integrated with the right wall surface of the left rib 208 forming the recess 230. The guide support member 232 is plate-shaped, and has a first vertical portion 232A extending substantially vertically from the bottom surface 230A in a side view, and an inclined portion 232B extending obliquely upward from the upper end of the vertical portion 232A. And a second vertical portion 232C extending substantially vertically upward from the upper end of the inclined portion 232B. Further, as shown in FIG. 7, coil portions 246 and 247 of a torsion coil spring 240 described later are disposed between the first vertical portion 232A and the bottom surface 230A. Thereby, the movement to the apparatus rear side of the torsion coil spring 240 is suppressed by the first vertical portion 232A. The inclined portion 232 </ b> B and the second vertical portion 232 </ b> C serve as guides when the coil portions 246 and 247 of the torsion coil spring 240 are accommodated in the accommodation recess 230. The stopper 224 is provided with an opening 224B through which the accommodation recess 230 can be visually recognized.

  As shown in FIG. 8, the torsion coil spring 240 is made of a wire and has a symmetrical shape in front view. Specifically, the torsion coil spring 240 includes coil portions 246 and 247 in which a wire is wound in a coil shape in a side view, and linear portions 244 and 245 in which the wire extends obliquely upward from the coil portions 246 and 247, The support portions 242 and 243, in which the wire is wound in a coil shape at the upper ends of the straight portions 244 and 245, and the wire extends from the coil portions 246 and 247 to the rear side of the device, and the right and left sides of the torsion coil spring 240 are connected to each other. And a spring receiving portion 248. The torsion coil spring 240 is not limited to a wire material, and may be a plate material.

  The spring receiving portion 248 includes pressure receiving portions 248A and 248B extending to the rear side of the device, and a connecting portion 248C for connecting the end portions of the pressure receiving portions 248A and 248B on the rear side of the device, as described above. In the receiving recess 230. Specifically, the connecting portion 248C enters the notch 208B of the rib 208A, and the coil portions 246 and 247 are disposed between the first vertical portion 232A and the bottom surface 230A. And as FIG. 3 shows, the upper part of the accommodation recessed part 230 is covered by the stopper 224 of the peeling guide 220. FIG. In this manner, the coil portions 246 and 247 are dropped between the first vertical portion 232A and the bottom surface 230A, and when the peeling guide 220 is attached, the stoppers fitted between the ribs 208 and 208. It is sandwiched by 224 and held in the housing recess 230 (see FIG. 7). A notch 224A is formed at the tip of the stopper 224, and the rib 208A is engaged with the notch 224A.

  Further, as shown in FIG. 7, shaft portions 214A protruding from both side surfaces of the pinch roller 214 are respectively inserted on the inner peripheral sides of the pair of left and right support portions 242, 243 so that the pinch roller 214 can rotate. It is supported by. The pinch roller 214 is pressed against the discharge roller 210 rotatably supported on the housing 202 with the urging force of the torsion coil spring 240 as the rotation axis direction of the apparatus (see FIG. 3). The discharge roller 210 uses the drive motor 41 described above as a driving force, and can convey the paper P that has passed through the first paper conveyance path 88 while being nipped between the pinch rollers 214 (nip).

  Further, as shown in FIG. 2, the paper chute 260 constituting the first paper transport path 88 and the second paper transport path 90 is disposed at a position facing the peeling guide 220. The paper chute 260 includes a curved core member 262, and side walls 264 are provided at both ends of the core member 262 in the left-right direction of the apparatus. A shaft portion 265 that rotatably supports the side wall 264 on the housing 202 is provided on the side of the side wall 264 in the apparatus. The core member 262 is provided with a plurality of substantially triangular ribs 266 in parallel in the left-right direction of the apparatus in a side view, and covers the heating roller 62 and the pressure roller 64. The surface of the rib 266 located on the upper surface of the core member 262 is a conveyance path surface 267 of the second sheet conveyance path 90.

  Further, when there is no paper P on the first paper conveyance path 88, the paper chute 260 has its own weight and the leading end of the rib 266 enters between the ribs 222 of the peeling guide 220. Further, when the paper P is sent out from the nip portion 66 between the heating roller 62 and the pressure roller 64, the leading end of the rib 266 of the paper chute 260 is pushed up by the sent paper P, and the paper P is transported by the first paper. The paper passes through the path 88 and is sent to the paper discharge port 40. When reversing the paper P, the discharge roller 210 is reversed and the paper P is fed back onto the conveyance path surface 267 of the paper chute 260.

  As shown in FIG. 2, a duplex unit 269 is disposed above the paper chute 260 so as to face the paper chute 260. The duplex unit 269 is attached to the cover 10 </ b> A, and forms a second paper transport path 90 with the paper chute 260. A nip release lever 268 that releases the pressure contact between the heating roller 62 and the pressure roller 64 is provided above the paper chute 260. The nip release lever 268 is rotatably supported by the housing 202 and is configured to release the pressure contact between the heating roller 62 and the pressure roller 64 by rotating counterclockwise.

  Next, an attaching procedure for attaching the torsion coil spring 240 to the housing 202 of the fixing device 200 will be described with reference to the drawings. It is assumed that the conveyance path member 206 is attached to the housing 202 in advance.

  First, as shown in FIGS. 4 and 8, both shaft portions 214 </ b> A of the pinch roller 214 are inserted into the support portions 242 and 243 of the torsion coil spring 240, respectively.

  Next, as shown in FIGS. 4 and 7, the spring receiving portion 248 of the torsion coil spring 240 is accommodated in the accommodating recess 230. Specifically, first, the connecting portion 248C of the spring receiving portion 248 is hooked on the notch 208B of the rib 208A of the housing recess 230, and then the coil portions 246 and 247 are connected to the second vertical portion 232C, the inclined portion 232B, and The first vertical portion 232A is used as a guide to be placed on the bottom surface 230A. Accordingly, the coil portions 246 and 247 are disposed between the first vertical portion 232A and the bottom surface 230A.

  Then, after all the spring receiving portions 248 of the torsion coil spring 240 supporting the pinch roller 214 are accommodated in the accommodating recess 230, the peeling guide 220 is attached to the guide attaching portion 204 as shown in FIGS. Specifically, first, the protrusion 225 of the peeling guide is fitted into the hole 251 of the guide mounting portion 204. Next, the protrusion 226 is inserted from the front side of the groove 252 of the guide attachment portion 204 with the protrusion 225 as a reference. Then, the protrusions 227 and 228 of the peeling guide 220 are fitted into the holes 253 and 254 of the guide mounting portion 204, respectively. When these protrusions are fitted into the holes, the boss 229 and the hole 255 overlap. At this time, the stopper 224 fits between the rib 208 and the rib 208 to cover the accommodation recess 230. Then, the screw 256 is screwed into the female screw of the boss 229 through the hole 255 from the rear side of the housing 202. Thereby, the peeling guide 220 is attached to the guide attachment portion 204, that is, the housing 202. A torsion coil spring 240 is also attached to the housing 202.

  Next, as shown in FIG. 3, the discharge roller 210 is rotatably attached to the housing 202 through a shaft portion 210 </ b> A through holes (not shown) provided in the side wall 202 </ b> A and the side wall 202 </ b> B of the housing 202. At this time, the pinch roller 214 is pressed against the discharge roller 210 by the biasing force of the torsion coil spring 240.

Next, the operation of the first embodiment will be described.
As shown in FIG. 8, after the spring receiving portion 248 is received in the receiving recess 230, the peeling guide 220 is attached to the guide mounting portion 204 of the housing 202, so that the receiving recess 230 is covered with the stopper 224. A torsion coil spring 240 is attached to 202.

  Further, since the shaft portion 214A of the pinch roller 214 is supported so as to be directly rotatable by the support portions 242 and 243 of the torsion coil spring 240, the attaching operation between the pinch roller 214 and the torsion coil spring 240 is simplified.

  Further, when the peeling guide 220 is attached to the housing 202, the protrusions 225, 226, 227, and 228 of the peeling guide 220 are fitted (inserted) into the holes 251, 253, and 254 and the groove 252 of the guide attachment portion 204, respectively. Thus, the attachment position of the peeling guide 220 is determined. Thereby, the accuracy of the distance between the tip 220A of the peeling guide 220 and the heating roller 62 can be stably improved.

  In the first embodiment, the spring receiving portion 248 of the torsion coil spring 240 that urges the pinch roller 214 is fitted into the housing recess 230, the housing recess 230 is covered with the stopper 224 of the peeling guide 220, and the torsion coil spring 240 is covered with the housing 202. However, the present invention is not limited to this configuration. For example, among the registration rollers 25 arranged on the first paper conveyance path 88, the one that is driven to rotate is attached by a torsion coil spring 240. The spring receiving portion 248 of the torsion coil spring 240 is housed in a housing recess provided in the housing of the image forming apparatus 10 and provided in the transport path member 280 that forms the paper feed transport path 82 shown in FIG. The torsion coil spring 240 may be attached to the image forming apparatus 10 by being covered with a stopper. Of course, the present invention may be applied to any one of the registration roller 24, the conveyance roller 48, and the pressure roller 64 that is driven to rotate.

  In the above-described embodiment, the torsion coil spring 240 is used as the spring. However, the present invention is not limited to this configuration. For example, a leaf spring 300 as shown in FIG. 9 may be used. 9 includes a bent portion 302 of a plate material, a spring receiving portion 304 extending from the bent portion 302, a straight portion 306 extending upward from the bent portion 302, and a pinch roller 214 at the upper end of the straight portion 306. And a support portion 308 that is rotatably supported.

  The embodiments of the present invention have been described above with reference to the embodiments. However, these embodiments are merely examples, and various modifications can be made without departing from the scope of the invention. It goes without saying that the scope of rights of the present invention is not limited to these embodiments.

DESCRIPTION OF SYMBOLS 10 Image forming apparatus 11 Image forming part 80 1st paper feed conveyance path (paper conveyance path)
88 First paper transport path (paper transport path)
200 Fixing device 202 Housing (device main body)
210 Discharge roller (drive rotating member)
214 Pinch roller (driven rotating member)
220 peeling Guide 220B transport road 224 stopper (cover part)
230 Housing recess (housing portion)
240 Torsion coil spring (spring)
246 Coil part (bent part)
247 Coil part (bending part)
248 Spring receiving portion 280 Conveyance path member 300 Leaf spring 302 Bending portion 304 Spring receiving portion P Paper

Claims (2)

An image forming unit that forms an unfixed toner image on the paper;
A fixing unit that heat-fixes the toner image formed on the paper;
A driven rotating member that is driven to rotate in contact with the rotating driving rotating member, conveys the paper fed from the fixing unit together with the driving rotating member, and discharges the paper to the outside;
A spring that biases the driven rotating member and presses the driven rotating member against the drive rotating member;
A receiving portion that is provided between the fixing portion and the driven rotation member and that is provided on a conveyance path member that guides the sheet fed from the fixing portion and that houses a part of the spring;
A peeling guide that is attached to the upstream side of the transport path member in the paper transport direction , has a cover portion that covers the storage portion, and constitutes a transport path for guiding the paper between the drive rotation member and the driven rotation member; ,
A first rib that is provided in the conveyance path member so as to sandwich the driven rotation member provided on the downstream side in the sheet conveyance direction of the peeling guide from both axial sides of the driven rotation member, and guides the sheet;
A second rib provided on the surface of the cover portion, extending toward the driven rotation member sandwiched between the first ribs, and guiding paper between the drive rotation member and the driven rotation member;
An image forming apparatus. The spring is formed by bending a wire or a plate, a spring receiving portion provided at one of the bent portions is received in the receiving portion, and a support portion provided at the other of the bent portions rotates the driven rotation member. The image forming apparatus according to claim 1, wherein the image forming apparatus is supported.

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