JP2003223090A - Image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To facilitate the jam processing and maintenance. <P>SOLUTION: A copying machine 100 has a copying machine main body 102, a paper carrying path 124 disposed at a downstream side of a photoreceptor drum 108, a bypass paper feed path 160, a fixing unit 130, and a pair of ejection rollers 140. In the copying machine main body 102, a movable unit 200 is disposed so as to be freely drawn forward. The paper carrying path 124 is formed on the upper surface of the movable unit 200. The fixing unit 130 and an ejection roller unit 300 including the pair of ejection rollers 140 are arranged in the movable unit 200. The ejection roller unit 300 is disposed so as to be turnable with respect to the movable unit 200 at the front of the copying machine main body 102. The fixing unit 130 has a pressure roller 132 disposed in the movable unit 200, and a fixing upper housing 133 with a heat roller 131 disposed therein. The fixing upper housing 133 is disposed on the movable unit 200 so as to be turnable backward. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as an electrostatic copying machine, a laser printer or a facsimile.
In particular, it relates to a large-sized image forming apparatus capable of forming an image on a large-sized sheet such as JIS A0 or A1.

[0002]

2. Description of the Related Art In an image forming apparatus, for example, a large electrostatic copying machine capable of forming an image on a large size sheet such as JIS A0 or A1, a document conveying path is formed on the upper end surface of the copying machine body. The document transport path is equipped with a document transport device. At the upstream end of the document transport path,
The document placing table projects in front of the main body of the copying machine. A contact image sensor is arranged at the upper end of the main body of the copying machine. An image forming unit including a photosensitive drum and the like is arranged at an upper position in the main body of the copying machine. At the lower position in the main body of the copying machine, there are provided a paper storage unit including a paper feed roller and the like, and a paper transport path for transporting the paper stored in the paper storage unit to the transfer area of the image forming unit. In this paper transport path, various transport roller pairs for transporting the paper wound around the paper feed rollers in the paper storage unit through the paper transport path, a cutter mechanism for cutting the paper into appropriate lengths, etc. Is provided. On the downstream side of the transfer device included in the image forming unit, a paper conveyance path for conveying the paper on which the toner image is transferred by the transfer device is provided. A fixing device is provided in this paper transport path,
A discharge roller pair is provided on the downstream side of the fixing device.
A sheet discharge port is provided on the downstream side of the discharge roller pair so as to open to the front surface of the copying machine body. A bypass sheet feeding path is provided below the sheet conveying path extending from the transfer device toward the pair of discharge rollers. A bypass table for inserting paper into a bypass paper feed port of a bypass paper feed path is arranged on the front surface of the copying machine body, and a discharge tray is provided below the front side of the bypass table.

A document inserted into the document feeding device through the document insertion port is fed by the document feeding device in the downstream direction of the document feeding path. The image of the original document conveyed on the original document conveyance path is read by the contact image sensor. The image read by the contact image sensor is converted into a toner image by the image forming unit, and then transferred by the transfer device onto the sheet conveyed from the sheet storage section. The toner image transferred and carried on the paper is fixed by the fixing device, and the paper on which the toner image is fixed is discharged to the discharge tray through the paper discharge port by the discharge roller pair. The sheet conveyed from the sheet storage section is cut into a predetermined length by a cutter mechanism at an appropriate timing. The image reading and copying operations of the original are performed by the copying machine having the original reading device in the above-described manner, and a copy in which the image of the original is recorded is generated. On the other hand, by using the bypass table and manually inserting the paper from the bypass paper feed port into the bypass paper feed path, it is also possible to record the image of the original document conveyed through the document conveyance path on the paper at appropriate timing. Is.

[0004]

In the copying machine of the above-mentioned form, a document conveying path is formed on the upper end surface of the copying machine body,
At the upstream end of the document transport path, a document placing table projects from the copying machine body to the front of the copying machine body. And
A fixing device, a pair of discharge rollers, a paper discharge port, and the like are arranged along the paper conveyance path in the main body of the copying machine below that, and a bypass paper feed path is arranged below the paper conveyance path. . The configuration of the paper transport path is simple,
Almost no paper jams occur. However, by any chance,
In the case where a jam occurs in the bypass paper feed path, the paper transport path on the downstream side of the photosensitive drum, and the fixing device and the discharge roller pair disposed in the paper transport path, the above copying machine uses the bypass paper feed path. The upper part of the path can be pulled out in front of the main body of the copying machine, leaving the photosensitive drum and the like. When a jam occurs, pull out the portion and open the upper part of the front side of the paper transport path, which is the downstream side of the photosensitive drum, and the upper part of the bypass paper feed path to perform the jam processing. Was. However, when it is difficult to remove the paper when a jam occurs in the fixing device or the discharge roller pair, or in the maintenance of the fixing device or the discharge roller pair, the components that are fastened to each other by screws are used. This was done by removing some of them by releasing the fastening with screws. As a result, it has been relatively difficult to perform jam processing or maintenance on the fixing device or the pair of discharge rollers, and improvement has been desired.

An object of the present invention is that in addition to facilitating jam handling and maintenance in a sheet conveying path on the downstream side of the photosensitive drum, a bypass sheet feeding path extending below the sheet conveying path, and the like. Further, it is another object of the present invention to provide a novel image forming apparatus capable of easily performing jam processing and maintenance of a fixing device and a discharge roller pair arranged in the paper conveyance path.

[0006]

According to the present invention, a main body of an image forming apparatus, a photosensitive drum disposed in the main body,
A sheet conveying path extending from the downstream side of the photosensitive drum toward the front surface of the main body, a bypass sheet feeding path extending below the sheet conveying path, and a fixing device arranged in the sheet conveying path,
In an image forming apparatus provided with a pair of discharge rollers arranged on the downstream side of a fixing device, a movable unit is provided in the main body so as to be able to be pulled out in front of the main body, and the lower surface of the movable unit and the main body The bypass paper feed path is formed between the two, and the paper transport path is formed on the upper surface of the movable unit.
The fixing unit and a discharge roller unit including the discharge roller pair are disposed in the movable unit, and the discharge roller unit is arranged so as to be rotatable forward from the front surface of the main body with the lower end portion as the rotation center with respect to the movable unit. And the fixing device is
The upper fixing housing includes a pressure roller arranged in the movable unit and a fixing upper housing in which a heat roller is arranged.
There is provided an image forming apparatus, wherein the movable unit is disposed so as to be able to turn rearward with a lower end portion of a rear end portion as a turning center. When the movable unit is pulled out to the front of the main body with respect to the main body, the paper transport path and a part of the bypass paper feed path are opened upward, and the discharge roller unit is swung forward from the front surface of the main body. When the fixing roller is rotated, the discharge roller pair and the fixing device are opened, and when the fixing upper housing is rotated rearward, the heat roller, which is relatively pressed against the pressure roller from above, becomes the pressure roller. On the other hand, it is preferable that the upper region of the pressure roller is opened upward by being spaced apart. The movable unit is releasably locked at a predetermined mounting position with respect to the main body between both sides in the width direction of the movable unit and both sides in the width direction of the main body, which are opposed to both sides in the width direction of the movable unit. Locking mechanisms are respectively arranged, and each of the locking mechanisms is provided with a lock pin respectively arranged on both side portions in the width direction of the main body, and a pivoting mechanism arranged on both side portions in the width direction of the movable unit. A hook member releasably engageable with a corresponding lock pin, for releasing the engagement of each hook member and pulling out the movable unit from the mounting position to the front and pushing into the mounting position. It is preferable that the handles are provided, and the handles provided on each of the hook members are made to project forward from both sides of the movable unit.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a copying machine, which is an image forming apparatus, constructed according to the present invention will be described below in detail with reference to the accompanying drawings.

Referring to FIG. 1, a copying machine generally designated by reference numeral 100 includes a copying machine main body 102 having a substantially rectangular parallelepiped shape. A document transport path 103 is provided on the upper end surface of the copying machine main body 102.
A is formed, and the document feeding device 1 is provided in the document feeding path 103A.
03 is provided. At the upstream end (right end in FIG. 1) of the document feeding path 103A, the document placing table 10 is provided.
Extends from the main body 102 of the copying machine to the front of the main body 102 of the copying machine. A document insertion port 105 is formed at the upstream end of the document feeding device 103 in cooperation with the document feeding path 103A. In the document feeder 103, a carry-in roller pair 103a, a document pressing roller 103b, and a discharge roller pair 103c are arranged in this order from the upstream side to the downstream side of the document feeding path 103A. At the upper end of the copying machine main body 102, directly below the document pressing roller 103b,
An imaging device, in the embodiment a contact image sensor 104, is provided.

Below the contact image sensor 104,
An image forming unit (image forming unit) 106 is provided. The image forming unit 106 includes a photosensitive drum 108. The photosensitive drum 108 is rotationally driven counterclockwise in FIG. 1 by a driving unit (not shown). Around the photoconductor drum 108, a main charger 110 that uniformly charges the surface of the photoconductor drum 108, and an image of an original document that is read and output (photoelectrically converted and output) by the contact image sensor 104 are displayed. A device for converting an electric signal into light and irradiating the surface of the photoconductor drum 108 to form an electrostatic latent image, in the embodiment, an LED print head 112, an electrostatic charge formed on the surface of the photoconductor drum 108. Developing device 1 for developing a latent image into a toner image
14, a transfer device 116 for transferring the toner image formed on the surface of the photosensitive drum 108 to a sheet such as plain paper,
A cleaning device 118 for wiping and collecting the toner remaining on the surface of the photoconductor drum 108 is provided. The photoconductor drum 108 and the main charger 110, the LED print head 112, the developing device 114, and the like arranged around the photoconductor drum 108 constitute the image forming unit 106. The document placing table 10, the document transport path 103A, the document transport device 103, the contact image sensor 104, and the like constitute a document reading device provided in the copying machine 100.

At a lower position inside the copying machine main body 102, a sheet storage section 120 including a sheet feed roller and the like, and a sheet transport path for transporting sheets stored in the sheet storage section 120 to a transfer area of the image forming means 106. 122 is provided. The paper transport path 122 extends almost vertically. Paper transport path 1
22 is a paper feed roller (not shown) for feeding the paper wound around the paper feed roller in the paper storage unit 120 to the paper feed path 122, and the paper fed to the paper feed path 122 is fed through the paper feed path 122. Various conveying roller pairs 1
22a, 122b and 122c, a cutter mechanism 123 for cutting the sheet into an appropriate length, and the like.
Downstream of the transfer device 116, and thus the photoconductor drum 10
A sheet conveying path 124 for conveying the sheet on which the toner image has been transferred by the transfer device 116 is provided on the downstream side of the sheet transfer device 8. The paper transport path 124 is provided on the photosensitive drum 10.
It extends substantially horizontally from the downstream side of 8 toward the front surface 102a of the copying machine main body 102. Paper transport path 12
The fixing device 130 is disposed downstream of the fixing device 4, and the discharge roller pair 140 is provided downstream of the fixing device 130.

Referring to FIGS. 1 and 2, a pair of discharge rollers 1
A paper discharge port 150 is provided on the downstream side of the copying machine main body 40.
It is arranged so as to open to the front surface 102a of the second. In the following description, the front of the copying machine 100 or the copying machine main body 102 means the right side in FIGS.
The width direction indicates the front and back direction of the paper surface in FIGS. Inside the copying machine main body 102, a bypass paper feed path 160 that extends in a substantially horizontal direction is provided below the paper transport path 124 at a distance. The upstream end of the bypass paper feed path 160 is located on the front surface 102 of the copying machine main body 102.
a, which is connected to the bypass sheet feeding port 162 opened below the sheet discharging port 150, and the downstream end of the bypass sheet feeding path 160 is a downstream region of the sheet conveying path 122 and the transfer device. It is connected to the upstream side of 116, and in the embodiment, immediately upstream of the transport roller pair 122c. In the bypass paper feed path 160, a separation roller 164, which contacts a friction plate (not shown), and a pair of registration rollers 1
66 and the like are provided. Front side 1 of copier body 102
02a also has a bypass table 16 for inserting paper into the bypass paper feed port 162 of the bypass paper feed path 160.
8 is provided, and a discharge tray (pocket) 170 is provided below the front side of the bypass table 168.

In the copying machine 100, the basic form of the image reading and copying operation of the original document is carried out in substantially the same manner as in the prior art described above. The part related to the action and effect will be described. Referring to FIGS. 2 and 3, in the copying machine main body 102, a movable unit 200 is provided so that the photosensitive drum 108 remains in the copying machine main body 102.
It is arranged so that it can be pulled out in front of the copying machine main body 102 so as to be separated from it. The movable unit 200 includes a pair of side walls 202 facing each other on both sides in the width direction of the copying machine main body 102 at intervals, and a lower surface 20 extending between the side walls 202.
4 and. 2 to 5, only one side wall 202 of the pair of side walls 202 is shown.
An upright flange portion 206 (only one of which is shown in FIGS. 2 and 3 is shown) is formed at an upper end portion near each front end portion of the side walls 202, and each of the upright flange portions 206 is provided with a screw thread. The hole 206a is formed. The lower surfaces of the movable unit 200 on both sides in the width direction are provided on both sides of the copier body 102 corresponding to the front and rear directions of the copier body 102 via appropriate guide rail means, in the embodiment, an acrylide (trade name) not shown. It is movably supported by.

The movable unit 200 includes the fixing device 1 described above.
30 and a discharge roller unit 300 including a discharge roller pair 140 and a sheet discharge port 150 are arranged. A sheet conveyance path 124 is disposed on the upper surface of the movable unit 200 and upstream of the fixing device 130.
The bypass sheet feeding path 160 is formed between the lower surface 204 of the sheet and the bypass sheet feeding surface 161 formed on the copying machine main body 102. The movable unit 200 is provided with the upper roller 166a of the registration rollers 166a and 166b forming the registration roller pair 166 arranged in the bypass paper feed path 160. Movable unit 200
Of the transfer device 11 on the upstream side of the paper transport path 124 in
6 are provided. In the embodiment, the transfer device 11
6 is composed of a transfer corona discharger and a peeling corona discharger. On the upstream side of the transfer device 116 in the movable unit 200, one of the pair of transport surfaces 122d and 122e that constitutes the upstream end of the sheet transport path 122 and the discharge roller pair 122c. One roller 122c-1 of the rollers 122c-1 and 122c-2 is arranged.

The fixing device 130 includes a heat roller 131 and a pressure roller 132 which is pressed against the heat roller 131 from below.
And a fixing upper housing 133. The pressure roller 132 is supported by an upper end portion of each of the side walls 202 of the movable unit 200 toward the front so as to be biased upward via a bearing member (not shown) and a spring member (not shown). The upper fixing housing 133 has a pair of side walls 13 facing each other on both sides in the width direction of the copying machine main body 102 with a space therebetween.
4 and the upper wall 13 disposed between the upper ends of the side walls 134.
5 and the front wall 13 disposed between the front ends of the side walls 134.
6 and the rear wall 13 disposed between the rear ends of the side walls 134.
7, and has a rectangular parallelepiped shape with an open bottom. The front wall 136 is arranged in the upper end region and the intermediate region in the vertical direction, and does not exist between the upper end region and the intermediate region or below the intermediate region. In the upper fixing housing 133, a long hole 134a extending in a direction in which a front wall 136 and a rear wall 137 face each other is formed at a lower end portion near each front end portion of the side wall 134, and the side wall 1
A lock pin 138 is formed at a position near the upper end near each front end of each of 34 so as to project inward of each of the side walls 134, and at both ends of the upper wall 135 in the width direction of the copying machine main body 102. Upright flanges 139 are arranged in each case. The heat roller 131 is a fixing upper housing 133.
Each of the side walls 134 is rotatably disposed between the central portions of the lower ends thereof. Upper wall 1 of fixing upper housing 133
On the upper surface of 35, the document placing table 10 is detachably fastened to each of the upright flanges 139 via screws (not shown).

A swivel shaft 208 is provided so as to extend laterally outward at the upper end portion of each of the side walls 202 of the movable unit 200 in the approximately central portion in the front-rear direction. In the upper fixing housing 133, the lower ends of the rear ends of the side walls 134 of the movable unit 200 are fitted to the corresponding swivel shafts 208 on the outer sides in the width direction of the upper ends of the corresponding side walls 202 of the movable unit 200. It is supported so as to be able to turn in the front-rear direction about the turning axis 208. That is, the upper fixing housing 133 rotates between a fixing position (a position indicated by a solid line in FIG. 2 and a position indicated by a two-dot chain line in FIG. 3) and an open position (a position indicated by a solid line in FIG. 3). It is freely rotatable about the axis 208. When the upper fixing housing 133 is positioned at the fixing position, the heat roller 131 is pressed against the pressure roller 132 from above. Further, when the upper fixing housing 133 is swung rearward around each of the swivel shafts 208 from the fixing position to the open position, the heat roller 131, which is relatively pressed against the pressure roller 132 from above, moves to the pressure roller 132. On the other hand, the upper region of the pressure roller 132 is separated upward and is opened upward (see FIG. 3). The open position of the upper fixing housing 133 is defined by a stopper means (not shown) provided between the movable unit 200 and the upper fixing housing 133. When the upper fixing housing 133 is swung from the open position to the fixing position, the elongated holes 134a of the side wall 134 are respectively screwed into the screw holes 206a of the upright flange portion 206 of the movable unit 200.
Are aligned from the outside in the width direction, and are detachably fastened by screws (not shown). As a result, the upper fixing housing 133 is held at the fixing position with respect to the movable unit 200.

The discharge roller unit 300 is a pair of side walls 30 facing each other at intervals in the width direction of the copying machine main body 102.
2 and a front wall 304 extending between the front ends of each of the side walls 302.
It has and. Each of the side walls 302 is formed in a vertically long shape having a relatively narrow width in the front-rear direction. The discharge roller pair 140 is rotatably supported at a substantially central portion between the side walls 302 in the vertical direction. Of the front wall 304,
The paper discharge port 15 is provided on the downstream side of the discharge roller pair 140.
0 is formed. Between each of the side walls 302, an upper guide plate 305a and a lower guide plate 305b for guiding the sheet on which the toner is fixed by the heat roller 131 and the pressure roller 132 of the fixing device 130 to the discharge roller pair 140 are arranged. There is. A guide member 152 is disposed on the front wall 304 at a position below the sheet discharge port 150. Side wall 302
A hook member 306 is rotatably supported on the outer side of each of the above through a pivot shaft 308. An operating portion 306a is integrally formed at the front end portion of each hook member 306, and the operating portion 306a is projected forward of the front wall 304. Each hook member 306 is constantly urged to rotate clockwise in FIGS. 2 and 3 by a spring member (not shown) arranged between each hook member 306 and the corresponding side wall 302. . Front wall 304
The upper end portion of is covered with a cover member 310 which is arranged so as to be detachable from the front of the upper end portion. Hook member 3
Each of the operation portions 306a of 06 is projected on the front side of the cover member 310 on both sides of the cover member 310 and is vertically movable.

A swivel shaft 210 is arranged at the lower end of the front end of each of the side walls 202 of the movable unit 200 so as to extend laterally inward. Discharge roller unit 3
00, the lower end of each of the side walls 302 corresponds to the swivel shaft 210 corresponding to the inside of the movable unit 200 at the front end of the corresponding side wall 202 in the width direction.
And is supported so as to be able to turn in the front-rear direction with the turning shaft 210 as the turning center. That is, the discharge roller unit 300 is rotatable about the swivel axis 210 between the use position (see FIG. 2) and the open position (see FIG. 3). A stop lever 212 is rotatably supported via a swivel shaft 214 inside the front end of each side wall 202 of the movable unit 200. Each of the stop levers 212 has a lower end portion rotatably supported by a corresponding pivot shaft 214. An elongated hole 212a extending in the longitudinal direction of each stop lever 212 is formed in an upper region of each stop lever 212, and each elongated hole 212a of the stop lever 212 is formed.
Is the corresponding side wall 302 of the ejection roller unit 300.
Are fitted to the stop pins 312, which are arranged so as to respectively extend outward from the side.

When the discharge roller unit 300 is swung rearward about the swivel axis 210 from the open position toward the use position, each of the hook members 306 is attached to each of the side walls 134 of the fixing housing 133 by a spring member (not shown). The discharge roller unit 300 is locked to the lock pins 138 provided, and the discharge roller unit 300 is fixed to the fixing housing 13.
It is held in the use position with respect to the movable unit 200 via 3. The discharge roller pair 140 is positioned downstream of the heat roller 131 and the pressure roller 132 of the fixing device 130. Further, when each operating portion 306a of the hook member 306 is moved upward against the spring force of the spring member (not shown), each of the hook members 306 is swung counterclockwise around the swivel axis 308, and the hook member 306 is rotated. Each of the 306 is disengaged from its corresponding lock pin 138 to allow the discharge roller unit 300 to pivot forward about the pivot axis 210 from the use position toward the open position. The open position of the discharge roller unit 300 is obtained by bringing the stop pin 312 disposed on the corresponding side wall 302 of the discharge roller unit 300 into contact with one end (upper end) of each elongated hole 212a of the stop lever 212. The turning from the use position toward the open position is stopped, and the discharge roller unit 300 is held at the open position. As a result, the space between the discharge roller pair 140 and the fixing device 130 is opened upward.

Referring to FIGS. 4 and 5, the copying machine main body 10 is shown.
Frame plates 180 which face each other and stand upright are arranged at the front end positions on both sides in the width direction. A lock pin 182 extending outward is disposed at the upper end of each frame plate 180. A hook member 220 is provided at a front end portion on the outer side of each of the side walls 202 that define both side portions in the width direction of the movable unit 200.
It is rotatably supported via 2. Hook member 22
0 extends from the turning shaft 222 toward the rear of the copying machine main body 102. Each hook member 220 is constantly urged to rotate counterclockwise in FIGS. 4 and 5 by a spring member (not shown) arranged between each hook member 220 and the corresponding side wall 202. There is.
Each of the hook members 220 has a corresponding lock pin 182.
Can be releasably engaged with. Each of the hook members 220,
The corresponding lock pin 182 constitutes a lock mechanism for releasably locking the movable unit 200 at a predetermined mounting position with respect to the copying machine main body 102. Swivel axis 22
A support part 220a extending upward is integrally formed at the base part of each of the hook members 220 supported by 2.
The support portion 220a is integrally provided with a handle 223 extending forward. The handle 223 has a ring shape when viewed in the width direction of the copying machine main body 102. Each of the handles 223 releases the engagement between the corresponding hook member 220 and the lock pin 182, and pulls out the movable unit 200 from the mounting position (see FIGS. 2 and 4) to the front of the copying machine main body 102 (see FIG. 3). And FIG. 5) and is arranged to be pushed into the mounting position, and is projected forward from the front surface 102a of the copying machine main body 102 on both sides of the movable unit 200. The upper region of the front surface 102a of the copying machine body 102 is defined by the cover member 310 of the discharge roller unit 300 and the lower region of the front wall 304.

The front surface 102 of the copying machine main body 102 in a state where the fixing device 130 is held in the fixing position and the discharge roller unit 300 is held in the use position (the state shown in FIG. 2).
When the movable unit 200 pulled out to the front of the copying machine main body 102 is pushed toward the rear of the copying machine main body 102 by using each of the handles 223 projected forward from both sides of a, the movable unit 200 is moved. Hook member 220
Each of them is locked to the corresponding lock pin 182 by the action of a spring member (not shown), and the movable unit 200 is held at the mounting position shown in FIGS. 2 and 4. The movable unit 200 and the main body of the copying machine 102, and the respective constituent members provided in the movable unit 200 and the main body of the copying machine 102 have a positional relationship capable of performing the above-described copying operation. To be done.

When it becomes necessary to perform jam processing and maintenance on the sheet conveying path 124 on the downstream side of the photosensitive drum 108, the bypass sheet feeding path 160 extending below the sheet conveying path 124, or the like, or the sheet conveying path. When it becomes necessary to perform jam processing and maintenance on the fixing device 130 and the discharge roller pair 140 disposed on the sheet 124, the movable body is projected forward from the front surface 102a on both sides in the width direction of the copying machine main body 102. When each of the handles 223 of the unit 200 is pulled toward the front of the copying machine main body 102, each of the hook members 220 is rotated clockwise in FIG. 4 against the spring force of a spring member (not shown), and the lock pin 182 is rotated. The engagement with can be easily released (state shown by a chain double-dashed line in FIG. 4). In this state, by pulling each of the handles 223 further forward of the copying machine main body 102, the movable unit 200 is mounted at the mounting position (the position shown in FIGS. 2 and 4).
Can be easily pulled out in front of the copying machine main body 102 (see FIGS. 3 and 5). As shown in FIGS. 3 and 5, when the movable unit 200 is pulled out in front of the copying machine main body 102, a part of the paper transport path 124 and the bypass paper feed path 160 on the downstream side of the photoconductor drum 108. Since the areas are respectively opened upward, it is possible to easily remove the sheets accumulated in those areas and to easily perform maintenance of those areas. Further, since the upstream side of the photoconductor drum 108 of the paper transport path 122 is also opened, it is possible to perform jam processing for that area.

By operating the respective operating portions 306a of the hook members 306 of the discharge roller unit 300 as described above, the engagement of the respective hook members 306 with the corresponding lock pins 138 is easily released. Therefore, the discharge roller unit 300 can be easily swung forward around the swivel axis 210 from the use position to the open position. As a result, the discharge roller pair 140
Between the fixing device 130 and the fixing device 130 is opened upward (see FIG.
It is possible to easily perform jam processing on the discharge roller pair 140, maintenance of the discharge roller unit 300 including the discharge roller pair 140, and jam processing between the discharge roller pair 140 and the fixing device 130. It should be noted that the operation of rotating the discharge roller unit 300 from the use position to the open position and positioning the discharge roller unit 300 at the open position can be easily performed even when the movable unit 200 is held at the mounting position, and the jam processing of the discharge roller pair 140 is performed. Alternatively, maintenance of the discharge roller unit 300 can be easily performed. When the discharge roller unit 300 is pivoted from the open position to the use position as described above, each of the hook members 306 is automatically engaged with the corresponding lock pin 138, and the discharge roller unit 300 is It is automatically held in the use position.

With the movable unit 200 pulled out to the front of the copying machine main body 102 (in the state shown in FIGS. 3 and 5), the fixing upper housing 133 is released from the fixing position as described above. By turning to the position, the heat roller 131, which is relatively pressed against the pressure roller 132 from above, is separated upward from the pressure roller 132, and the upper region of the pressure roller 132 is opened upward ( (Because the state shown by the solid line in FIG. 3 is obtained), it becomes possible to easily perform jam processing in the fixing device 130 and maintenance of the fixing device 130. As described above, the upper fixing housing 133 is held at the fixing position by rotating the upper fixing housing 133 from the open position to the fixing position and performing a fastening operation with a screw (not shown).

After performing the necessary jam processing or maintenance, the movable unit 200 is pushed rearward of the copying machine main body 102 to the mounting position by using each of the handles 223, and the hook member 22 of the movable unit 200 is pushed.
0 is swung by the spring force of a spring member (not shown) and automatically locked by the corresponding lock pins 182, and the movable unit 200 is automatically moved to the mounting position shown in FIGS. 2 and 4. Retained.

[0025]

According to the image forming apparatus of the present invention, it is possible to easily perform jam processing and maintenance in the sheet conveying path on the downstream side of the photosensitive drum, the bypass sheet feeding path extending below the sheet conveying path, and the like. In addition to the above, it is possible to easily perform the jam processing and the maintenance on the fixing device and the discharge roller pair arranged on the sheet conveying path.

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing a configuration of an embodiment of an electrostatic copying machine according to the present invention.

FIG. 2 is a schematic cross-sectional view showing in more detail an enlarged main part of a fixing unit provided in the copying machine shown in FIG.

FIG. 3 is a schematic cross-sectional view showing a state in which the fixing unit shown in FIG. 2 is pulled out and opened.

FIG. 4 is a schematic sectional view showing the configuration of a lock mechanism that releasably locks the fixing unit shown in FIG. 2 with respect to the copying machine main body.

FIG. 5 is a schematic sectional view partially showing a state in which the lock of the lock mechanism shown in FIG. 4 is released and the fixing unit is partially pulled out from the copying machine main body.

[Explanation of symbols]

100 copiers 102 Copier body 102a Front of copier body 122 paper transport path 124 Paper transport path 130 fixing device 131 heat roller 132 pressure roller 133 Fixing upper housing 140 discharge roller pair 150 paper outlet 160 bypass paper feed path 161 bypass paper feed surface 200 movable units 204 Lower surface of movable unit 220 hook member 223 handle 300 discharge roller unit

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Yasuhiro Michishita             Kyocera 1-22-28 Tamatsukuri, Chuo-ku, Osaka-shi             Within Mita Co., Ltd. F term (reference) 2H033 AA36 AA37 BA06 BB01 BB35                       BB38                 2H071 AA03 AA04 AA05 AA06 AA08                       AA13 AA18 BA04 BA14 BA24                       BA27 BA29 DA06 DA07 DA08                       DA09 DA12 DA13 DA15 DA24                 2H072 AA32 AB07 CA01 CA02 CB01                       CB03 DA04 EA18 EA19 HA04

Claims (3)

[Claims] 1. A main body of an image forming apparatus, a photoconductor drum arranged in the main body, a paper conveyance path extending from a downstream side of the photoconductor drum toward a front surface of the main body, and a paper conveyance path. In an image forming apparatus including a bypass sheet feeding path extending in a lower position, a fixing device arranged in the sheet conveying path, and a discharge roller pair arranged on the downstream side of the fixing device, A movable unit is provided in front of the main body so as to be freely drawn, the bypass sheet feeding path is formed between the lower surface of the movable unit and the main body, and the sheet conveying path is formed on the upper surface of the movable unit. The movable unit is provided with the fixing device and a discharge roller unit including the discharge roller pair, and the discharge roller unit can swing forward from the front surface of the main body with the lower end portion as a swing center with respect to the movable unit. The fixing device is provided , A pressure roller arranged in the movable unit, and an upper fixing housing in which a heat roller is arranged. The upper fixing housing is arranged in the movable unit so as to be rotatable rearward about the lower end of the rear end as the center of rotation. An image forming apparatus, which is provided. 2. When the movable unit is pulled out to the front of the main body with respect to the main body, the paper transport path and a part of the bypass paper feed path are respectively opened upward, and the discharge roller unit of the main body is opened. When swung forward from the front,
When the discharge roller pair and the fixing device are opened, and the fixing upper housing is swung backward, the heat roller, which is relatively pressed against the pressure roller from above, is separated upward from the pressure roller. The image forming apparatus according to claim 1, wherein the upper region of the pressure roller is opened upward. 3. The movable unit is mounted at a predetermined mounting position with respect to the main body between the widthwise both sides of the movable unit and the widthwise both sides of the main body, which face the widthwise both sides of the movable unit, respectively. A lock mechanism for releasably locking the lock unit is provided on each of the lock mechanism, and each of the lock mechanisms is provided with a lock pin provided on each side portion of the main body in the width direction and each turn mechanism provided on each side portion of the movable unit in the width direction. And a hook member that is releasably engageable with a corresponding lock pin. Each hook member is disengaged to draw the movable unit forward from the mounting position and The handle for pushing into the mounting position is provided, and the handle provided for each of the hook members is projected forward from both sides of the movable unit.
The image forming apparatus described.