JP2003316107A - Image forming apparatus, transport unit, intermediate transfer unit and process cartridge - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a color printer in which paper transfer failure and paper ejection failure are prevented, dead space is not formed between an intermediate transfer belt and paper ejection part, so that the device can be miniaturized and excellent maintenance of internal components, devices, and units is ensured. <P>SOLUTION: Paper P is transported so as to pass through a secondary transport position and a fixing position in a fixing device 30 toward a higher position. At least part of the paper receiving face 42 of an ejection stack part 40 tilts downward in the direction of an ejection port 41, and its lowermost end is formed from an inclined face that is lower than the ejection port 41. The intermediate transfer belt 10 is stretched so that the upper stretched portion of the belt 10 extends at an angle and along the paper receiving face 42 of the ejection stacking part 40. A photoreceptor drums 1A and 1B are disposed so as to face the lower stretched portion of the intermediate transfer belt 10. <P>COPYRIGHT: (C)2004,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 a copying machine, a printer and a FAX, and a transport unit, an intermediate transfer unit and a process cartridge used in the apparatus. Specifically, an image forming apparatus that transfers images on a plurality of image carriers to an intermediate transfer body and collectively transfers the images on the intermediate transfer body to a recording medium, and a transport unit, an intermediate transfer unit, and a process cartridge used in the apparatus. It is about.

[0002]

2. Description of the Related Art Conventionally, there is a tandem type color image forming apparatus in which four photosensitive drums as image bearing members are arranged in parallel along a horizontally stretched stretched portion of an endless belt-shaped intermediate transfer member. Known (for example, Japanese Patent Laid-Open No. 2001-1173)
No. 84). In this image forming apparatus, toner images of different colors are formed on the four photoconductor drums, and the toner images on the respective photoconductor drums are primarily transferred so as to be superposed on the intermediate transfer body. Then, the toner images superposed on the intermediate transfer body are collectively transferred onto a sheet as a recording medium. The sheet that has passed the secondary transfer position has the image fixed by the fixing unit, and then is ejected onto the sheet receiving surface (recording medium receiving surface) through the ejection port of the ejection unit located above the intermediate transfer member. . Further, the paper receiving surface of the discharge portion (see FIG. 13) of the image forming apparatus described in the above publication is formed by a flat surface portion which is horizontal at a portion far from the discharge port. Then, the portion near the discharge port is formed by a convex curved portion which is gradually curved and becomes lower as it approaches the discharge port. The toner cartridges of the respective colors are arranged in parallel in the horizontal direction below the horizontal flat surface of the paper receiving surface, and further below the toner cartridges, the support member is provided so that the upper stretched portion extends in the horizontal direction. A stretched intermediate transfer member is arranged.

[0003]

However, in the image forming apparatus provided with the discharging section as described in the above publication, an image is formed on a paper such as a thick paper having a large size or an OHP sheet, and the discharging is performed. When attempting to discharge the sheet, there is a possibility that defective discharge may occur as follows. Cardboard and O
When a sheet such as an HP sheet is used, as shown in FIG. 13, the trailing edge portion PT of the sheet P does not bend along the inclined curved portion 401a of the recording medium receiving surface 401 due to the strength (rigidity) of the sheet P. It will be in a state of being lifted upwards. Further, even when the paper P is curled in a direction orthogonal to the paper discharge direction, the rear end portion PT of the paper P is not bent along the inclined curved portion 401 a of the paper receiving surface 401 and is lifted upward. In this way, the paper receiving surface 401 of the discharge unit 400
When the trailing edge portion PT of the sheet P discharged above is lifted upward, it collides with the leading edge portion of the succeeding sheet discharged to the discharging portion after that. Therefore, there is a possibility that defective ejection of the paper may occur.

On the other hand, the above-mentioned conventional image forming apparatus is provided with a plurality of sets of image forming means such as a photosensitive drum and an accompanying charging device, and an endless belt-like intermediate transfer stretched on a plurality of supporting members. Since the body is placed inside the device, the size of the entire device tends to increase. Therefore, in particular, it has been desired to reduce the dead space in the device as much as possible and to downsize the device. However, in the image forming apparatus including the plurality of photoconductor drums and the intermediate transfer member, when the internal components / apparatus / unit are arranged so as to eliminate the dead space in the apparatus body for downsizing of the apparatus, the photoconductor There is a problem in that the replaceability of the internal components / devices and units forming the image forming means including the drum and the intermediate transfer member is sacrificed, and the maintainability may be deteriorated. For example, Japanese Patent Laid-Open No. 2001-20923
No. 2 discloses that three photosensitive drums for color toner are opposed to an upper stretched portion of an intermediate transfer member (intermediate transfer belt),
An image forming apparatus is described in which a black photosensitive drum is opposed to a lower stretched portion. When an attempt is made to replace the central intermediate transfer member in this image forming apparatus, the upper photosensitive drum for color toner and its accompanying components are moved upward and retracted, and the lower photosensitive drum for black and Since it is necessary to move the components associated therewith downward and retract, the maintainability is poor.

The present invention has been made in view of the above problems, and it is an object of the present invention to prevent a conveyance failure and a discharge failure of a recording medium and to save a space by reducing a dead space in the apparatus. It is an object of the present invention to provide an image forming apparatus capable of achieving downsizing of the apparatus and having excellent maintainability of internal components / apparatuses and units, and a transport unit, an intermediate transfer unit and a process cartridge used in the apparatus.

[0006]

In order to achieve the above-mentioned object, the invention of claim 1 comprises a plurality of image carriers, and image forming means for forming images of different colors on each image carrier,
An endless belt-shaped intermediate transfer member which is stretched and driven by a plurality of support members so as to pass through a primary transfer position facing each image carrier and an image of each color formed on each image carrier An image on the intermediate transfer member is collectively recorded on a recording medium at a primary transfer unit for transferring the image onto the intermediate transfer member in an overlapping manner and a secondary transfer position located at one end side in the horizontal direction of the intermediate transfer member. Secondary transfer means for transferring, fixing means provided above the secondary transfer position so as to fix the image on the recording medium that has passed through the secondary transfer position, and 2 in the secondary transfer means.
The recording medium is conveyed so as to pass upward through the next transfer position and the fixing position of the fixing unit, the recording medium receiving surface located above the intermediate transfer member, and the fixing unit. An image forming apparatus comprising: a discharge unit having a discharge port for discharging a recording medium onto the recording medium receiving surface, wherein at least a part of the recording medium receiving surface of the discharging unit is on the discharge port side. Is inclined downward as it approaches, and its lowermost end is formed with an inclined surface lower than the discharge port,
The intermediate transfer body is stretched so that the intermediate transfer body extends obliquely along the inclined surface of the discharge section, and the plurality of intermediate transfer bodies are arranged so as to face the lower stretched section of the intermediate transfer body. The image carrier of 1 is arranged. According to another aspect of the image forming apparatus of the present invention, at least a part of the recording medium receiving surface of the ejecting portion is an inclined surface that is inclined downward as it approaches the ejecting port side and the lowermost end thereof is lower than the ejecting port. Therefore, the recording medium ejected from the ejection port can be received on the recording medium receiving surface having the inclined surface in a state where the rear end of the recording medium is inclined so as to be lower than the ejection port. Therefore, it is possible to eject a plurality of recording media in a state where the trailing edge of the recording medium received by the recording medium receiving surface is less likely to collide with the leading edge of the succeeding recording medium continuously ejected from the ejection port. Here, if the intermediate transfer body located below the recording medium receiving surface having the inclined surface of the discharge portion is stretched in the horizontal direction, the space between the inclined surface of the recording medium receiving surface and the intermediate transfer body is extended. Becomes a dead space. Therefore, the intermediate transfer member is stretched so that the intermediate transfer member extends obliquely along the inclined surface of the recording medium receiving surface of the discharge section.
As a result, the intermediate transfer body and the inclined surface of the recording medium receiving surface of the discharge portion are brought close to each other so that no dead space is generated between them. Further, a plurality of image carriers are arranged so as to face the lower stretched portion of the intermediate transfer member. This allows
A plurality of image forming means for each image carrier can be collectively disposed below the lower stretched portion of the intermediate transfer body, and each image forming means is disposed at a relatively close position. Therefore, unlike the case where the image forming means is provided separately on the upper and lower tension portions of the intermediate transfer member, some of the constituent elements of each image forming means can be shared. Further, it is possible to further reduce the space inside the device. Further, since a plurality of image forming means for each image carrier can be collectively disposed below the lower stretched portion of the intermediate transfer member, the internal components such as the intermediate transfer member and the image carrier or the intermediate transfer member can be arranged. When a unit such as a unit or a process cartridge is replaced, only the lower stretched portion of the intermediate transfer member may be retracted so as to separate the image carriers.
Therefore, as compared with the case where a plurality of image carriers are arranged so as to face both the upper stretched portion and the lower stretched portion of the intermediate transfer member, the attachment and detachment of the internal constituent parts and units becomes easier. According to a second aspect of the present invention, in the image forming apparatus according to the first aspect, the image forming unit is configured to form images of a plurality of mutually different colors on at least one of the image carriers. It is a feature. According to a third aspect of the present invention, in the image forming apparatus according to the first or second aspect, the conveying unit supports and conveys the recording medium along a conveying path that passes through the secondary transfer position and goes to the fixing position. As described above, the transport belt member is stretched by a plurality of supporting members. According to a fourth aspect of the invention, in the image forming apparatus according to the third aspect, the conveyor belt member is formed of a heat resistant material. The invention of claim 5 relates to claim 3
Alternatively, the image forming apparatus of No. 4 is provided with a moving unit capable of integrally moving the conveyor belt member and a part of the conveyor path forming member forming the conveyor so as to open the conveyor path. It is a feature. According to a sixth aspect of the present invention, in the image forming apparatus according to the fifth aspect, the moving unit conveys the recording medium that has passed through the fixing unit so that the recording medium is re-passed through the secondary transfer position with its front and back surfaces reversed. It is characterized in that it is provided with a conveying means for double-sided image formation. According to a seventh aspect of the present invention, in the image forming apparatus according to the fifth or sixth aspect, when the moving unit is moved so as to open the conveyance path, the conveyance belt member and a part of the conveyance path formation member The transport unit integrally configured to include is detachable from the moving unit.
According to an eighth aspect of the present invention, in the image forming apparatus according to the first or second aspect, for forming an image of each color to be supplied to the image forming unit between the intermediate transfer body and the recording medium receiving surface of the discharge section. A plurality of toner accommodating portions for accommodating mutually different toners are arranged in parallel, and a heat shield for interrupting heat transfer from the fixing means to the toner accommodating portion between the toner accommodating portion and the fixing means. It is characterized by having means. According to a ninth aspect of the invention, in the image forming apparatus according to the eighth aspect, a heat insulating member is provided as the heat shielding means. According to a tenth aspect of the invention, in the image forming apparatus according to the eighth or ninth aspect, the heat shield means is provided with a ventilation means for circulating air between the toner accommodating portion and the fixing means. It is a thing. According to an eleventh aspect of the present invention, in the image forming apparatus according to the first or second aspect, for forming an image of each color to be supplied to the image forming unit between the intermediate transfer body and the recording medium receiving surface of the discharge section. A plurality of toner storage portions for storing different toners are arranged in parallel, and the toner storage portions are formed of a heat insulating material. According to a twelfth aspect of the present invention, in the image forming apparatus according to the first or second aspect, for forming an image of each color to be supplied to the image forming means between the intermediate transfer body and the recording medium receiving surface of the discharging section. A plurality of toner accommodating portions for accommodating mutually different toners are arranged in parallel, and the toner accommodating portion and the intermediate transfer body do not interfere when the intermediate transfer body is moved to separate from the plurality of image bearing bodies. As described above, a space is provided between the toner containing portion and the intermediate transfer member. According to a thirteenth aspect of the present invention, in the image forming apparatus according to any one of the eighth to twelfth aspects, the toner storage portion is
It is characterized in that it can be attached to and detached from the main body of the image forming apparatus. According to a fourteenth aspect of the present invention, in the image forming apparatus according to any one of the first to thirteenth aspects, an intermediate transfer unit integrally configured to include the intermediate transfer body and a supporting member thereof is separated from the image carrier. It is characterized in that it is attachable to and detachable from the image forming apparatus main body in this state. According to a fifteenth aspect of the present invention, in the image forming apparatus according to any one of the first to fourteenth aspects, the image carrier, a charging device that constitutes the image forming unit, a developing device, and cleaning for cleaning the surface of the image carrier are performed. A process cartridge integrally configured to include at least one of the apparatuses is detachable from the main body of the image forming apparatus. The invention of claim 16 relates to claim 1
In the image forming apparatus of any one of 1 to 14, a process cartridge integrally configured to include at least a charging device and a developing device that constitute the image forming unit,
It is characterized in that it can be attached to and detached from the image forming apparatus main body independently of the image carrier in a state of being separated from the image carrier. According to a seventeenth aspect of the present invention, in the image forming apparatus according to any one of the first to sixteenth aspects, the image transfer is performed with respect to the plurality of image bearing members, and the image forming member is a component of the image forming unit. The intermediate transfer member and the facing component are configured to be movable so as to separate the facing component facing the carrier, and the intermediate transfer member and the facing component are separated from the image carrier. In this state, only the image carrier is attachable to and detachable from the apparatus main body. According to an eighteenth aspect of the present invention, in the image forming apparatus according to any one of the first to thirteenth aspects, a process cartridge integrally configured to include the image bearing member, the intermediate transfer member and a supporting member thereof is an image forming apparatus. It is characterized in that it can be attached to and detached from the main body of the forming apparatus. The invention of claim 19 relates to claim 15, 16 or 18
In the above image forming apparatus, the process cartridge is integrally provided for all or some of the plurality of image carriers.

According to a twentieth aspect of the present invention, in the image forming apparatus according to the first or second aspect, among the constituent elements constituting the image forming means, the facing constituent elements facing the plurality of image carriers are moved downward. And a moving mechanism section for moving the facing component downward so as not to interfere with the moving component when the facing component is taken out after being separated from the plurality of image carriers. And a space is provided between the moving mechanism section and the moving mechanism section. According to a twenty-first aspect of the invention, in the image forming apparatus according to the twentieth aspect, the moving mechanism portion has an abutting surface with which a lower end portion of a rail member supporting the facing constituent element abuts from above, and the rail. A cam member that is movable in a direction intersecting the contact direction of the lower end of the member is used, and the movement of the cam member causes the facing component to take an image forming position and a separated position separated from the image carrier. As a result, the contact surface of the cam member is formed. Claim 22
The invention of claim 21 is the image forming apparatus according to claim 21, wherein the moving mechanism moves the cam member that moves the facing component from the image forming position to the spaced position, and the intermediate transfer member and the intermediate transfer member. It is characterized in that the supporting member is configured to be moved from the image forming position to a separated position separated from the image carrier. According to a twenty-third aspect of the present invention, in the image forming apparatus according to the twenty-second aspect, the moving mechanism portion is engaged with the cam portion provided at one end portion and the cam member so as to rotate in association with the cam member. And a cam portion of the lever member, the cam portion of the lever member separates the intermediate transfer member and its supporting member from the image forming position and the image forming position. It is characterized in that it is formed so as to move to and from a position. According to a twenty-fourth aspect of the invention, in the image forming apparatus according to the twenty-third aspect, the lever member is provided with a knob for an operator to rotate the lever member. According to a twenty-fifth aspect of the invention, in the image forming apparatus according to the twenty-third aspect, the cam portion of the lever member is formed so as to be operable by an operator so as to rotate the lever member. .. According to a twenty-sixth aspect of the present invention, in the image forming apparatus according to the twenty-third aspect, the conveying means supports and conveys the recording medium along a conveying path that passes through the secondary transfer position and goes to the fixing position. The transport belt member is constructed by using a transport belt member stretched by a plurality of support members, and the transport belt member and a part of the transport route forming member forming the transport unit are integrally formed so as to open the transport route. A movable unit is provided, and the lever member is configured to rotate in conjunction with movement of the moving unit to open the transport path. According to a twenty-seventh aspect of the present invention, in the image forming apparatus according to any one of the twenty-sixth to twenty-sixth aspects, a case member to which the facing component is attached, and a case member fixed to the case member and in a direction of a rotation axis of the image carrier are provided. A movable rail member that is movable is provided.

According to a twenty-eighth aspect of the present invention, there is provided a conveying unit in the image forming apparatus according to the seventh aspect, wherein the conveying unit includes the conveying belt member and a part of the other conveying member.
It is characterized in that it is attachable to and detachable from the moving unit moved so as to open the transport path.
According to a twenty-ninth aspect of the invention, in the transport unit according to the twenty-eighth aspect, one roller of the registration roller pair is provided as a part of the transport member, and a cleaning unit for cleaning the roller is provided. is there. According to a thirtieth aspect of the present invention, the transport unit according to the twenty-eighth aspect is characterized in that it is provided with an accommodating portion for accommodating the foreign matter removed by the cleaning means. According to a thirty-first aspect of the invention, there is provided the intermediate transfer unit in the image forming apparatus according to the fourteenth aspect, which is integrally configured to include the intermediate transfer body and a supporting member for the intermediate transfer body, and an image in a state of being separated from the image carrier. It is characterized in that it can be attached to and detached from the main body of the forming apparatus. A thirty-second aspect of the present invention is a process cartridge in the image forming apparatus according to the fifteenth aspect, wherein the image carrier, a charging device that constitutes the image forming means, a developing device, and a surface of the image carrier are cleaned. At least one of the apparatuses is integrally configured and is detachably attached to the main body of the image forming apparatus. The invention of claim 33 is
The process cartridge in the image forming apparatus according to claim 16, wherein the image forming unit includes a charging device, a developing device, and a cleaning device that cleans a surface of the image carrier, the image forming unit being integrally formed. It is characterized in that it can be attached to and detached from the main body of the image forming apparatus independently of the image carrier in a state of being separated from the carrier. A thirty-fourth aspect of the present invention is a process cartridge in the image forming apparatus according to the eighteenth aspect, which is integrally configured to include the image bearing member, the intermediate transfer member and a supporting member thereof, and is provided in the image forming apparatus main body. It is characterized by being removable.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment in which the present invention is applied to a color printer (hereinafter referred to as "printer") as an image forming apparatus will be described below.

FIG. 1 is a front view showing a schematic configuration of a printer according to this embodiment. The printer includes two photosensitive drums 1A and 1B as image bearing members. A static eliminator L, a cleaning device 2, a charging device 3, and two developing devices 5A and 5B are provided on the outer peripheral portion of the first photosensitive drum 1A.
Is provided. The photosensitive drum 1A is rotatably supported and rotates in the direction of the arrow in the figure. The light emitted from the lower exposure device 4 enters between the charging device 3 and the developing device 5B, and optical information is written. Second photoconductor drum 1
The parts around B are the same as the first photosensitive drum 1A.
It is the same as that of. Further, each developing device 5A, 5B, 5
In C and 5D, toners as developers of different colors are used. These developing devices 5A, 5B, 5
Each of C and 5D is movable in the direction of the arrow in the drawing, and has a mechanism (not shown) that comes into contact with and separates from the corresponding photosensitive drum 1A, 1B. Here, the photosensitive drum 1
The image forming means for forming a toner image on A and 1B includes the charging device 3, the exposure device 4 and the developing devices 5A, 5B and 5 described above.
It is composed of C, 5D and the like. The photosensitive drum 1, the cleaning device 2, the charging device 3, the developing device 5A,
5B, 5C, 5D and the like are configured as a process cartridge 52 that is integrally incorporated and can be attached to and detached from the apparatus main body, and can be replaced at the end of its life.

A part of the two photosensitive drums 1A and 1B is in contact with an endless belt-shaped intermediate transfer member (hereinafter referred to as "intermediate transfer belt") 10 at a primary transfer position. This intermediate transfer belt 10 is movable in the direction of the arrow in the figure,
It is supported and stretched between support rollers 11 and 12 as rotating support members. On the back side (inside the loop) of the intermediate transfer belt 10, a primary transfer roller 20 as a primary transfer unit and a backing roller 14 are provided in the vicinity of the photosensitive drums 1A and 1B. An intermediate transfer member cleaning device 25 is provided on the outer peripheral surface side of the intermediate transfer belt 10. The intermediate transfer member cleaning device 25 wipes off unnecessary toner remaining on the surface of the intermediate transfer belt 10 after the toner image is secondarily transferred onto the sheet P as a recording medium and then cleaned. The cleaning device 25 for the intermediate transfer member is configured to be rotatable about a rotation center 25A so that the cleaning blade 25B comes into contact with and separates from the surface of the intermediate transfer belt 10 by a contacting / separating mechanism (not shown). Also,
The intermediate transfer belt 10, the intermediate transfer member cleaning device 25 and the like around the intermediate transfer belt 10 are integrally configured as an intermediate transfer unit 51 that can be attached to and detached from the apparatus main body, and can be replaced at the end of its life.

The exposure device 4 is a well-known laser type exposure device, and uniformly exposes the photosensitive drums 1A, 1B to laser light whose intensity is controlled based on image information corresponding to full-color image formation. The surface of is irradiated to form an electrostatic latent image. As the exposure device 4, a combination of a known LED array and an image forming means can be used.

The photosensitive drums 1A and 1B have a diameter of 40.
A layer of an organic semiconductor which is a photoconductive substance is provided on the surface of an aluminum cylinder of about 100 mm. A belt-shaped photoreceptor may be used as the image carrier. It is also possible to adopt a type of photosensitive drum that uses amorphous silicon.

The intermediate transfer belt 10 is a seamless endless belt having an electric resistance value such that a toner image can be transferred from the photosensitive drums 1A and 1B.
The intermediate transfer belt 10 used in this embodiment has a thickness of 50.
A low surface energy coating is applied as a surface layer on a substrate made of a resin film or rubber having a thickness of from μm to 500 μm. The volume resistivity of the entire intermediate transfer belt 10 is in the range of 10 ⁵ to 10 ¹² Ωcm,
The surface resistivity is in the range of 10 ⁶ to 10 ¹³ (Ω / □).

In FIG. 1, at the right end of the printer, an endless conveyor belt 100 is arranged as a belt member which constitutes a recording medium conveying means. The conveyor belt 100 is supported and stretched between support rollers 111 and 112 as support members so as to be movable in the direction of the arrow in the figure. A secondary transfer roller 120 serving as a secondary transfer unit is arranged near the support roller 11 that supports the intermediate transfer belt 10 on the back side (inside the loop) of the transport belt 100. Further, the conveyor belt 100 is attached to the support roller 11
Also provided is a backing roller 115 for making pressure contact with the side. These secondary transfer roller 120 and backing roller 1
15 and a supporting roller 1 for supporting the intermediate transfer belt 10.
1 forms a transfer nip portion where the intermediate transfer belt 10 and the transport belt 100 contact each other with a predetermined nip width at the secondary transfer position.

On the outer peripheral surface side of the conveyor belt 100, there is provided a conveyor belt cleaning device 250 having a blade 250B for removing dust and unnecessary toner adhering to the surface of the conveyor belt 100. The dust and the waste toner removed by the cleaning device 250 are conveyed to a collecting section (not shown) by the toner conveying means 250C.

The conveyor belt 100 and the conveyor belt cleaning device 250 are integrally constructed as a conveyor belt unit (conveying unit) 250U. By swinging the transport belt unit 250U around a rotation fulcrum C by a drive mechanism (not shown), the transport belt 100 can be brought into contact with and separated from the intermediate transfer belt 10.

The conveyor belt 100 includes a heating roller 30.
Since it passes near the fixing device 30 as a fixing unit composed of a or the like, it has heat resistance up to about 200 ° C.,
Further, the belt member is formed of a medium-resistance belt member having a volume resistivity of about 10 ⁸ to 10 ¹⁰ Ωcm. In this embodiment, a belt member made of polyimide or polyamide having a substrate thickness of 50 μm to 500 μm is used.

The fixing device 30 includes a heating roller 30a having a built-in heat source such as a heater, and the paper P on which the toner image is secondarily transferred is conveyed while being pinched by the heating roller 30a, so that the image on the paper P is conveyed. Can be fixed. Since the fixing device 30 is arranged so as to be located above the printer, heat is less likely to be trapped inside the device, and it is possible to prevent a decrease in reliability due to a temperature rise.

The paper P is stored in paper feed devices (paper feed cassettes) 26-1 and 26-2 set at the bottom of the printer. Then, the uppermost sheet P is fed by the sheet feed roller 27.
Guide member 2 as a plurality of transport path forming members one by one
It is conveyed via 9 to the position of the registration roller pair 28.

At the upper part of the printer, in addition to the fixing device 30, paper ejection guide members 31A and 31B, a paper ejection roller pair 3 are provided.
2. A sheet discharge stack section 40 as a sheet discharge section is provided.

The paper discharge stack section 40 is a fixing device 30.
It has a discharge port 41 for discharging the sheet P which has passed through the sheet and is guided by the sheet discharge guide members 31A and 31B and sent out by the sheet discharge roller pair 32. Further, the paper discharge stack unit 40 has the paper P discharged from the discharge port 41 as indicated by an arrow A in the figure.
It has a paper receiving surface 42 as a recording medium receiving surface for receiving the recording medium. The main receiving surface 42 which is a part of the paper receiving surface 42
The a is inclined downward at a constant inclination angle as it approaches the discharge port 41 side, and its lowermost end is a flat inclined surface lower than the discharge port 41 (see FIG. 2). In the intermediate transfer belt 10, the upper stretched portion has the discharge stack portion 40.
The support rollers 11 and 12 are stretched to extend so as to incline along the main receiving surface 42a which is an inclined surface.

A toner cartridge mounting portion TS is provided above the intermediate transfer belt 10 and below the paper receiving surface 42 of the paper discharge stack portion 40, and toner capable of storing replenishment toner to be replenished to the developing device. A toner cartridge TC as a storage unit is detachably attached. The toner cartridge TC is provided for each of four color toners (magenta, cyan, yellow, black: a, b, c, d in the figure). The toner in each toner cartridge is supplied to the developing device of the corresponding color by a powder pump (not shown).

The toner cartridge TC can be attached and detached by opening a door D (see FIG. 6 described later) on the front side of the printer body. The door D is configured such that it can be opened with a rotation shaft (not shown) provided at the left end and extending in the vertical direction as a rotation center. This rotation axis is on the right side of the operation panel OP (see FIG. 6 to be described later), and even when the door D is opened, the information displayed on the operation panel OP and the inside of the paper feed cassette can be seen from the front operation position. Is possible.

A heat insulating member W is arranged as a heat shield between the toner cartridge mounting portion TS in which the toner cartridge TC is mounted and the fixing device 30 having a heat source. The heat insulating member W prevents transfer of heat from the fixing device 30 to the toner cartridge mounting portion TS, and prevents the replenishment toner in the toner cartridge TC from being melted and fixed by repeated heating and cooling. As the heat insulating member W, for example, resin, flocked resin, or a laminate of these materials having an air layer can be adopted. Further, as the heat shielding means, a ventilation means for circulating air between the toner cartridge mounting portion TS and the fixing device 30 may be provided. As illustrated in FIG. 1, the ventilation unit includes a fan F2 attached to the side plate side of the printer body and an air flow path that passes between the toner cartridge mounting portion TS and the fixing device 30 and reaches the fan F2. Can be configured. When the outside air is taken in by this ventilation means, the surrounding area is cooled, which is more effective. Further, among the toner cartridges TC, the toner cartridge d particularly near the fixing device 30 may be formed of a heat insulating material, or the portion of the toner cartridge mounting portion TS to which the toner cartridge d is mounted may have a heat insulating structure. It is effective.

The swing unit 50 as a moving unit on the side of the conveyor belt 100 on the right side of the printer body can swing to a position shown in FIG. 3 around an opening / closing support shaft 50A as a swing shaft. By swinging the swing unit 50 as shown in FIG. 3, the transport path of the paper P is opened, and the jam processing when the transport failure of the paper P occurs is facilitated. Further, by opening the swing unit 50, it becomes easy to take out the transport belt unit 250U including the above-described transport belt 100.

At the upper part of the rocking unit 50, there is provided a fan F1 which operates to exhaust air to the outside of the device in order to prevent the temperature inside the device from rising excessively. Further, on the left side portion of the printer body, electrical equipment / control devices E1 and E2 including a low voltage power source, a high voltage power source, a board and the like are arranged.

Further, in addition to the conveyor belt 100, the paper P that has passed through the fixing device 30 is conveyed to the swing unit 50 such that the paper P is passed through the secondary transfer position again with its front and back surfaces reversed. Conveying means for double-sided image formation is provided. This double-sided image forming transport means has a rotating shaft G.
A switching guide member G1, which is swingable around 0, a film-shaped switching guide member G2, and a re-feeding conveyance path PG.
1, PG2, PG3, PG4, and transport rollers R1 to R4. When forming images on both sides of the paper P, first, the image is formed on one surface of the paper P. Then, after being fixed by the fixing device 30, the sheet P guided by the switching guide member G1 is gripped by the transport roller R1 so as to press the film-shaped guide member G2, and is fed to the re-feed transport path PG1. Follow along. After the rear end has passed the guide member G2, the conveyance roller R1 is rotated in the reverse direction while being held by the conveyance roller R1. The paper P is
The side that has been under the guide member G2, the side that has been the rear end until now becomes the front end, is conveyed by the conveyance rollers R2, R3, and R4, and is registered along the re-feed conveyance paths PG2, PG3, and PG4. 28. Then, the color toner image formed on the intermediate transfer belt 10 is transferred again to form a color image on both sides of the paper P.

When performing normal image formation in the printer having the above construction, first, toner image formation on the photosensitive drums 1A and 1B and transfer onto the intermediate transfer belt 10 are performed. In the meantime, the transport belt 100 keeps the intermediate transfer belt 10
The conveyor belt unit 250U is oscillated around the fulcrum 250C so as to be separated from.

In the toner image forming operation on the photoconductor drums 1A and 1B, light from an LD (semiconductor laser) light source (not shown) of the exposure device 4 passes through optical parts such as a polygon mirror and is uniformly charged by the charging device 3. Photosensitive drum 1
The surface of A is irradiated. By this irradiation, an electrostatic latent image corresponding to the writing information (information according to color) is formed.
In this example, optical information to be developed with magenta toner is written. Here, the surface of the photosensitive drum 1A is
It is exposed so that a positive electrostatic latent image is formed. As a result, the image transferred onto the sheet P via the intermediate transfer belt 10 becomes a normal image. The magenta electrostatic latent image on the photoconductor drum 1A is moved to a position where the developing device 5A containing magenta toner can develop, and is developed. The toner image (visual image) of the magenta toner is primarily transferred by the primary transfer roller 20 onto the surface of the intermediate transfer belt 10 that moves in synchronization with the photosensitive drum 1A. After the primary transfer, the surface of the photoconductor drum 1A is cleaned by the cleaning device 2 to remove the residual toner, and then discharged by the charge removing device L to prepare for the next image forming cycle.

The intermediate transfer belt 10 carries the magenta toner image transferred on its surface and moves in the direction of the arrow.
On the surface of the other photosensitive drum 1B, optical information to be developed in yellow color is written to form an electrostatic latent image for yellow, and the latent image is developed by the developing device 5C containing the yellow toner. It This yellow toner image is superimposed on the magenta toner image already formed on the intermediate transfer belt 10.

The toner images of the above two colors (magenta and yellow) are transferred to the photosensitive drum 1A together with the intermediate transfer belt 10.
When it moves to that position, the light information corresponding to black is synchronously written on the photoconductor drum 1A and an electrostatic latent image for black is formed. The electrostatic latent image for black is developed by the developing device 5B containing black toner. Then, the black toner image on the photosensitive drum 1A is primarily transferred onto the surface of the intermediate transfer belt 10 in the same manner as described above, with the third color superimposed. On the surface of the other photosensitive drum 1B, light information to be developed in cyan color is written to form an electrostatic latent image for cyan, which is developed by a developing device 5D containing cyan toner. It
This cyan toner image is superposed on the toner images of three colors already formed on the intermediate transfer belt 10, whereby a full-color image of four colors is formed on the intermediate transfer belt 10. In the full-color image forming mode including the four color toners, the intermediate transfer belt 10 rotates twice and passes twice through the primary transfer position facing the respective photosensitive drums 1A and 1B.

When the intermediate transfer belt 10 rotates and moves to a predetermined position, paper feeding is started from the paper feeding device (paper feeding cassette) 26. When the paper feed roller 27 rotates in the direction of the arrow, the uppermost paper P in the paper feed device (paper feed cassette) 26 is pulled out and conveyed to the registration roller pair 28. The intermediate transfer belt 10 is passed through the registration roller pair 28.
The toner image on the surface of the intermediate transfer belt 10 is transferred by the secondary transfer roller 120 onto the surface of one side of the paper P sent between the transfer belt 100 and the transport belt 100. At this time, the intermediate transfer belt 1
0 and the conveyor belt 100 are running while contacting each other. Further, the sheet P is conveyed upward, and at the time of the secondary transfer, the sheet P is conveyed at a timing so that the image position becomes a regular position.

In this embodiment, the photosensitive drums 1A and 1B are
The polarity of the toner of the image formed on is negative. Therefore, by applying a positive charge to the primary transfer roller 20, the toner imaged on the photosensitive drums 1A and 1B is transferred to the intermediate transfer belt 10. Further, by applying a positive charge to the secondary transfer roller 120, the toner image formed on the intermediate transfer belt 10 is transferred to one surface of the paper P.

The paper P on which the toner image is transferred on the surface in the above process is sent to an area of the fixing device 30, and the toner images (both sides) on the paper P are fixed at one time. Then, after passing through the guide members 31A and 31B, the sheet is discharged from the sheet discharge roller pair 32 to the sheet receiving surface 42 of the sheet discharge stack portion 40 provided on the upper portion of the main body frame.

Dust and toner adhering to the conveyor belt 100 after the secondary transfer is cleaned by the cleaning blade 25.
The toner is scraped off at 0B and collected in a storage unit (not shown) by the toner conveying means 250C.

In the case of forming a single color image instead of a full color image with the printer having the above configuration, the secondary transfer process onto the paper P is executed without rotating the intermediate transfer belt 10 twice, and the intermediate transfer belt 10 is executed. The mileage of can be shortened.

In the printer having the above-mentioned structure, the control command from the operator such as setting various parameters is given in FIG.
It can be performed from the operation panel OP shown in (1) or the keyboard of the host computer HC. When performing image formation on both sides of the paper P, it can be selected by a double-sided button (not shown) provided on the operation panel (OP). Further, the selection of the special paper and the selection of the paper feed cassette 26 can be performed by the setting button for the paper feed button. In a system to which a host computer is connected as an image forming system (see FIG. 6 described later), it is convenient to display a setting screen on the display of the host computer HC so that the setting instruction can be made on the screen. .

In the printer having the above structure, the heat energy applied to the sheet P by the fixing device 30 is smaller when forming a single color image than when forming a full color image. Therefore, at the time of forming a monochromatic image, for example, control is performed such that the power supplied to the heat source located on the non-image side is reduced or not supplied. Further, when double-sided image formation in which images are formed on both sides of the paper P is executed, if an even page image is formed first and an odd page image is formed next,
On the paper receiving surface 42 of the paper discharge stack section 40, odd-numbered pages are placed with the lower surface. Therefore, when the paper P is taken out from the paper discharge stack section 40, the page order is convenient, which is convenient. When double-sided image formation is performed, the trailing edge of the sheet P having an image formed on one side when the sheet P is re-fed is now the leading edge and enters the secondary transfer position. To do. Therefore, the second photosensitive drum 1A, 1B
The formation of the electrostatic latent image for the surface is controlled so as to be created from the side corresponding to the rear end.

FIG. 4 is a front view showing a schematic configuration of a printer according to another embodiment. The basic configuration of this printer is the same as that of the printer shown in FIG. 1, and the common parts are denoted by the same reference numerals and the description thereof is omitted. The printer shown in FIG. 4 is not the laser type exposure apparatus used in the printer shown in FIG. 1, but an exposure apparatus 4 including an LED array provided independently for each photoconductor drum in order to further miniaturize the apparatus. Is used. Further, in the printer of FIG. 4, in order to secure a predetermined peripheral length of the intermediate transfer belt 10 and reduce the size in the left-right direction in the drawing, the traveling path of the intermediate transfer belt 10 is formed into a triangular shape. It is stretched around one support roller 11, 12, 13. The photosensitive drums 1A and 1B are connected to the intermediate transfer belt 10
Are arranged side by side so as to face the outer peripheral surface of the lower tension portion extending in the horizontal direction. Further, in the printer of FIG. 4, the size in the left-right direction in the drawing is reduced to reduce the size without providing a conveying unit for double-sided image formation. Further, in the printer of FIG. 4, the process cartridge 53 can be replaced at the end of its life. The process cartridge 53 includes the photosensitive drums 1A and 1B, the cleaning device 2, the charging device 3, the exposure device 4, and the developing devices 5A and 5B.
Together with 5C and 5D, the intermediate transfer belt 10 and its cleaning device 25 can be integrally attached to and detached from the apparatus main body.

Also in the printer of FIG. 4, the swing unit 50 on the right side of the printer body on the side of the conveyor belt 100.
However, it is possible to swing about the opening / closing support shaft 50A to the position shown in FIG. By swinging the swinging unit 50 as shown in FIG. 5, the conveyance path of the paper P is opened, and the jam processing when the conveyance failure of the paper P occurs becomes easy, and the unit including the conveyance belt 100 is provided. It is also easy to take out.

FIG. 6 is a front view showing a schematic configuration of a printer according to still another embodiment. The basic configuration of this printer is the same as that of the printer shown in FIG. 1, and the common parts are denoted by the same reference numerals and the description thereof is omitted. Figure 6
Is different from the printer shown in FIG. 1 above.
This is a so-called tandem type color image forming apparatus provided with four photosensitive drums 1A, 1B, 1C and 1D. The image forming unit provided with each photoconductor drum includes a charging device 3 as a facing component around the photoconductor drum,
The developing device 5, the static eliminator L, and the cleaning device 2 are provided. Then, the photosensitive drums 1A, 1B, 1C, 1
D is irradiated with optical information by a laser beam of color data branched from a multi-beam type exposure device 4 commonly used for each image forming unit. Further, in the printer of FIG. 6, in order to secure the predetermined circumferential length of the intermediate transfer belt 10 and reduce the size of the left end portion in the drawing in the thickness direction, the shape of the running path of the intermediate transfer belt 10 is a triangle. The three support rollers 11, 12 and 13 are stretched. And
The photoconductor drums 1A, 1B, 1C, 1D are arranged side by side in an oblique direction so as to face the outer peripheral surface of the lower stretched portion of the intermediate transfer belt 10. Further, in the printer of FIG. 6, the moving unit 50 is not provided with a conveying unit for double-sided image formation, and the size in the left-right direction in the drawing is reduced to further reduce the size.

Further, in the printer shown in FIG. 6, the intermediate transfer unit 51 including the intermediate transfer belt 10 as well as the cleaning device 25 as shown in FIG.
It can be swung in the clockwise direction indicated by arrow E in the figure with A as the swing center. As a result, the intermediate transfer belt 1
0 can be separated from the photosensitive drums 1A, 1B, 1C and 1D.

Further, the photoconductor cleaning device 2, the charging device 3, the static eliminator L and the developing device 5, which are the constituents of the image forming means for each photoconductor drum, are not shown in the figure while ensuring the proper positional relationship. The image forming unit is integrally configured as a cartridge and is housed in the image forming frame 54F. Then, when the rails R, which are the two left and right rail members of the image forming frame 54F, are lowered, the facing constituent elements such as the charging devices 3 constituting the image forming unit are set to the photosensitive drums 1A, 1A.
It can be separated from B, 1C and 1D. In this manner, the intermediate transfer unit 51 including the intermediate transfer belt 10 and the image forming frame 54 accommodating the components of the image forming means are pulled out toward the paper surface of FIG. You can do it. Then, in this separated state, the photosensitive drums 1A to
1D can be individually pulled out from its shaft 1 ', and the photoconductor drums 1A to 1D can be easily replaced at the end of its life.

The stretched shape of the intermediate transfer belt 10 in the intermediate transfer unit 51 and the size of the gap S1 in the upper space formed between the upper stretched portion of the intermediate transfer belt 10 and the toner cartridge TC are as follows. Is set like. As described above, when the photoconductor drum is attached or detached, the intermediate transfer unit 51 is swung. Therefore, the tension shape and the upper portion of the intermediate transfer belt 10 are prevented so that the upper tension portion between the support rollers 11 and 12 of the intermediate transfer belt 10 and the toner cartridge TC do not come into contact with each other when the intermediate transfer unit 51 swings. The size of the space gap S1 is set. The size of the gap S2 in the lower space formed between the developing device 5 and the exposing device 4 of the image forming means is set as follows. As described above, when the photosensitive drum is attached or detached or the charging device or the like is maintained, the image forming frame 54F in which the charging device 3 and the like are housed is moved downward. Therefore, when the image forming frame 54F is moved, each developing device 5
The size of the gap S2 in the lower space is set so that the lower end of the exposure device 4 and the exposure device 4 do not come into contact with each other. By setting in this way, the photosensitive drum can be replaced without damaging it. Further, the constituent elements such as a charging device that constitute the image forming means provided for each photoconductor drum face the surface of the photoconductor drum below the horizontal plane including the central axis of the corresponding photoconductor drum. Are arranged as follows. With such an arrangement, the image forming frame 54F including the image forming unit integrally formed with the charging device and the like can be lowered vertically downward.

FIG. 8 is an explanatory view of a moving mechanism portion for moving the intermediate transfer unit 51 and the image forming unit 54 as shown in FIG. One end 51A of the intermediate transfer unit 51
Is pressed against the stopper 67 by a short roller 68 pressed by a spring 69 from above, and the intermediate transfer belt 10 is positioned at a regular position. The lever member 71 is supported rotatably around the support shaft 65. The lower end of the lever member 71 is provided with a knob 71A for the operator to operate. Also, the lever member 71
A cam portion 73 is provided at the upper end of the. Stopper 6
Reference numeral 6 restricts the clockwise rotation of the lever member 71. A pin 63 fixed to a plate cam 60 as a cam member is engaged with an elongated hole 72 as an engaging portion provided on the lever member 71 under the support shaft 65. The plate cam 60 has two elongated holes 61 extending in the horizontal direction, and can be moved in the horizontal direction while being guided by two pins 64 provided in the image forming apparatus main body. Sloping surfaces 62A are provided at the upper ends of the plate cam 60.
Are formed, and horizontal surfaces 62B are formed on the left and right sides thereof. The inclined surface 62A and the horizontal surface 62B are contact surfaces with which the lower ends of the rails R serving as rail members supporting the image forming frame 54F, which is a case member of the image forming unit 54, come into contact with from above. When the rail R rides on the horizontal surface 62B of the plate cam 60, the image forming unit 54 is positioned at the image forming position. The rail R is attached to the main body of the image forming apparatus so as to be vertically movable. A slide rail R'as a movable rail member incorporated in the rail R is slidable in the direction perpendicular to the paper surface of FIG. An image forming frame 54F (a portion indicated by a chain line in FIG. 12) is fixed to the slide rail R '. The image forming frame 54F is provided with developing, charging, which is provided so as to face the photoconductor drums 1A to 1D.
An image forming unit 54, which is a process cartridge in which each opposing constituent element (image forming element) having a cleaning function and a charge removing function is formed as a cartridge, is held by a holding unit (not shown).

When the knob 71A of the lever member 71 is operated to move the lower side of the lever member 71 in the direction of arrow F in the moving mechanism section having the above-described structure, the lever member 71 rotates counterclockwise. At this time, the lever member 71 rotates while the cam portion 73 above the lever member 71 supports one end 51A of the intermediate transfer unit 51. This lever member 71
Rotation of the intermediate transfer unit 51 causes the support roller 11 to move.
The photosensitive drum 1 is rotated about the center 11A of the photosensitive drum.
Separated from A, 1B, 1C and 1D. The intermediate transfer unit 51 has a cam portion 73 at one end 51A (the left end in FIG. 8).
The other end (the right end in the figure) along the upper surface of the sheet can be pulled out in the direction of the front side of the paper surface of FIG. Further, by rotating the lever member 71 in the direction of arrow F, the plate cam 60 moves to the right, and the slope 6 of the plate cam 60 is moved.
The rail R descends along 2A. Each image forming unit 5 is attached to a slide rail R ′ incorporated in this rail R.
The image forming frame 54A holding 4 is attached. Therefore, with the rail R lowered, as shown in FIG. 9, each image forming unit 54 is moved with the facing constituent element (image forming element) forming the image forming means separated from the photosensitive drum. The image forming frame 54F can be pulled out together. By pulling out the image forming frame 54F in this way, the image forming unit 5 as a process cartridge in which the above-mentioned opposing constituent elements (image forming elements) are integrally configured.
4 can be replaced and maintained.

In FIG. 9, one image forming unit (process cartridge) 54A, 54B, ... Containing the facing component (image forming element) is formed for each photosensitive drum. However, the facing constituent elements (image forming elements) for the four photoconductor drums may be combined into one image forming unit 54. Further, a black image is formed on the rightmost photosensitive drum 1D, and only the above-mentioned facing component (image forming element) with respect to the photosensitive drum 1D is integrally configured as one independent image forming unit. May be. Then, the facing constituent elements (image forming elements) for the photoconductor drums 1A, 1B, and 1C that form other color images may be integrated into one image forming unit. When the black image forming unit is independently provided in this manner, only the black image forming unit that is frequently used can be replaced, which is economically convenient.

Further, in the configuration example of FIG. 8, when the moving mechanism is configured so that the intermediate transfer unit 51 and the image forming unit 54 are simultaneously separated from the photosensitive drum by rotating the lever member 71. However, the moving mechanism unit may be configured so that the intermediate transfer unit 51 and the image forming unit 54 are separated from each other.

Further, in FIG. 8, a protruding portion (operation portion) 60A is formed by protruding the right end portion of the plate cam 60 to the swing unit (moving unit) 50 side as shown by a broken line.
The exposed protrusion 60A may be pulled when the swing unit (moving unit) 50 is moved. When the operator pulls the protrusion 60A, the plate cam 6
0 moves to the swing unit (moving unit) 50 side, and the lever member 71 can be rotated counterclockwise.
Further, when the plate cam 60 is appropriately pressed by a spring so as to move to the right side, and the protrusion 60A is brought into contact with a part of the swing unit (moving unit) 50, the swing unit (moving unit) When 50 is released from the main body of the image forming apparatus, the plate cam 60 moves in conjunction with the movement of the swing unit (moving unit) 50 to open the transport path,
The lever member 71 can be rotated. Further, the cam portion 73 of the lever member 71 may be formed so that the operator can operate it so as to rotate the lever member.

Further, as shown in FIG. 8, when the facing component (image forming element) is moved downward to be separated from the photosensitive drum and then taken out, each facing component and the plate cam 60 of the moving mechanism portion. It is preferable to provide a space S'between the image forming frame 54F accommodating the opposing component (image forming element) and the plate cam 60 of the moving mechanism section so that the and S do not interfere with each other.

Also in the printers shown in FIGS. 6 and 7, the moving unit 50 including the conveyor belt 100 on the right side of the printer body is moved to the position shown in FIG. 7 by the telescopic guide rail mechanism GR via the support member SPT. You can move up to. By moving the moving unit 50 in this manner, the conveyance path of the paper P is almost opened,
Maintenance such as jam handling when the conveyance failure of the paper P occurs, cleaning of the charge eliminating charger CH for separation, cleaning of the conveyance guide 29, cleaning of the registration roller pair 28, and the like becomes easy. Furthermore, it is easy to take out the transport unit 250U including the transport belt 100. Especially the registration roller pair 28
One roller 28A and a part 29A of the transport guide 29
Since the and are provided on the side of the transport unit 250U, the above maintenance can be easily performed. The transport unit 250U can be taken out of the moving unit 50 by gripping the handle HD on the top and pulling it up in the direction of arrow D. The lower surface of the transport unit 250U is formed in a flat shape, and can be placed in a stable state on a flat surface such as a desk in the same posture.

FIG. 10 shows a transport unit 2 according to a modification which is detachable from the moving unit 50 of the printer shown in FIGS.
It is a schematic block diagram of 50U. A blade cleaner 260 is brought into contact with one roller 28A of the registration roller pair 28, and foreign matter such as paper dust scraped off from the blade cleaner 260 is collected and stored in a collecting container 260A. This collection container 260A
May be integrally configured with a container for storing dust and waste toner scraped off by the conveyor belt cleaning device 250. Further, in FIG. 10, these containers may be taken out in the front direction perpendicular to the paper surface, and may be appropriately discarded.

Further, the primary transfer means and the secondary transfer means in the printer shown in FIGS. 1 and 4 are roller types (primary transfer roller 20, secondary transfer roller) which come into contact with the intermediate transfer belt 10 and the conveyor belt 100, respectively. Roller 120)
However, a brush-shaped transfer member, a roller-shaped member formed by a brush, or the like can also be used. Furthermore, a non-contact discharge type (charger) can also be adopted.

In FIG. 11, the printers 301 and 302 shown in FIG. 1, FIG. 4 and FIG.
0 is an image forming system connected to a wired network cable 303. In this image forming system, the printers 301 and 302 are mainly the host computer 3.
00 as an output device. For example, an image read by the scanner 304 connected to the host computer 300 is appropriately edited, and the printers 301 and 302 are edited.
Can be output from. In addition, the printer 30
A wireless communication network may be used to connect between the host computers 1, 302 and the host computer 300 instead of a cable.

In the image forming system having the above-mentioned structure, the image forming process conditions of the image to be output and the paper P are followed according to the guide displayed on the display of the host computer 300.
It is possible to instruct or input the paper discharge form and the like. The status of the printers 301 and 302 can be displayed on the display of the host computer 300 to notify the operator.

The printer 302 shown in the lower part of FIG.
When the door D is opened and the image forming unit can be maintained, the paper feed cassette 26-2 is pulled out to replenish the paper P,
The state where exchange is performed is shown. By opening the door D, the intermediate transfer unit 51 and the process cartridges 52 and 53 can be pulled out with the exposure device 4 left in the main body. With these members pulled out, the photosensitive drums 1A and 1B, the intermediate transfer belt 10 and the like can be attached and detached. This process cartridge 52, 5
The guide 3 is guided by a guide rail (not shown) so that it can be pulled out easily and securely. Since the door D is supported by the hinge arranged in the vertical direction, the visibility of the maintenance parts thereunder is good even when the door D is opened.
Although not shown, a seal member is provided so that the components of the exposure device 4 are not contaminated with toner or the like.

As described above, according to the present embodiment, the sheet P is conveyed so as to pass upward through the secondary transfer position and the fixing position in the fixing device 30, so that the front end of the sheet P hangs down by its own weight. The sheet P can be reliably brought into the secondary transfer position and the fixing position without any trouble. Therefore, conveyance failure of the paper P can be prevented. Furthermore,
A main receiving surface 42a, which is at least a part of the sheet receiving surface 42 of the discharge stack portion 40, is inclined downward at a constant inclination angle as it approaches the discharge port 41 side, and its lower end is lower than the discharge port 41. It is an inclined surface. For this reason,
As shown in FIG. 12, the paper P discharged from the discharge port 41
Can be received on the sheet receiving surface 42 formed of a flat inclined surface in a state where the rear end is inclined so as to be lower than the discharge port 41. Therefore, a plurality of sheets can be ejected in a state in which the trailing edge of the sheet P received by the sheet receiving surface 42 is less likely to collide with the leading edge of the succeeding sheet P continuously ejected from the ejection port 41. Poor discharge of P can be prevented. In particular, the printer of this embodiment is
This is effective when the recording medium is a cardboard, an OHP sheet, or the like having a strong strain (high rigidity). Further, the upper stretched portion of the intermediate transfer belt 10 extends obliquely along the sheet receiving surface 42 of the discharge stack portion 40. For this reason, the upper stretched portion of the intermediate transfer belt 10 and the sheet receiving surface 42 of the discharge stack portion 40 are brought close to each other so that a dead space is not generated between them, and it is possible to save space inside the apparatus. Moreover, since a plurality of photosensitive drums are arranged so as to face the lower stretched portion of the intermediate transfer belt 10, a plurality of image forming means for each photosensitive drum are collectively arranged below the intermediate transfer belt 10. Can be provided, and the image forming units are arranged at relatively close positions. Therefore, unlike the case where the image forming means is provided separately on the upper and lower tension portions of the intermediate transfer belt, a part of the constituent elements of each image forming means (in the present embodiment, the exposure device 4) can be shared, and further space saving inside the device can be achieved. Therefore, the size of the device can be reduced. In addition, the intermediate transfer belt 10
When replacing internal components such as the photosensitive drums or units such as the intermediate transfer unit and the process cartridge, it is only necessary to retract the photosensitive drums so that only the lower stretched portion of the intermediate transfer belt 10 is separated. As a result, the internal components and units can be easily attached and detached as compared with the case where a plurality of photosensitive drums are arranged so as to face both the upper and lower stretched portions of the intermediate transfer belt. Become. Therefore, the maintainability of the internal components and units is excellent.

Further, according to this embodiment, the photosensitive drums 1A, 1B, the charging device 3, the developing devices 5A, 5B, 5
Image forming means such as C and 5D is provided below the intermediate transfer belt 10 apart from the fixing device 30 having the heat source. As a result, a toner image can be formed on the photosensitive drum without being adversely affected by heat generated by the fixing device 30. Further, the wedge-shaped space generated below the intermediate transfer belt 10 is effective for the layout of the components of the image forming unit by inclining the upper stretched portion of the intermediate transfer belt 10 along the paper receiving surface 42. Available. Moreover, in the configuration of the printer according to the present embodiment, the lower stretched portion of the intermediate transfer belt 10 is located at the secondary transfer position from the facing portion of the plurality of photosensitive drums that is far from the secondary transfer position. It moves toward the portion facing the photoconductor drum located at a position close to. Therefore, the distance from the primary transfer position to each photoconductor drum to the secondary transfer position for transferring the paper P can be shortened. Therefore, the time from the start of the printing operation to the output of the first sheet P (first printing time) can be shortened.

In particular, as in the printer shown in FIG. 1 of the present embodiment, when the image forming means is formed so that toner images of two different colors can be formed on each of the photosensitive drums 1A and 1B. Can form a full-color image without using four photosensitive drums. Therefore, it is possible to further reduce the size of the printer that can form a full-color image.

Further, according to the present embodiment, the conveying means for conveying the sheet P is arranged along the conveying path which faces the intermediate transfer belt 10 at the secondary transfer position and passes through the secondary transfer position.
A plurality of support rollers 111, 11 so as to support and convey
It is configured by using the conveyor belt 100 stretched by 2. Therefore, the transportability of the paper P can be secured and the reliability can be improved.

Further, according to the present embodiment, since the conveyor belt 100 is made of a heat-resistant material, even if the conveyor belt 100 is arranged close to the fixing device 30 having a heat source, the conveyor belt 100 will not move. No alteration or deformation occurs. Further, by bringing the transport belt 100 close to the fixing device 30, the paper P having unfixed toner is surely fixed on the fixing device 30.
It is possible to prevent the occurrence of abnormal images.

Further, according to this embodiment, the conveyor belt 1
00, the swing unit (moving unit) 50 capable of swinging about the opening / closing support shaft 50A can be swung (moved) to the positions shown in FIGS. 2, 4, and 7, respectively. By this swinging (moving), the conveyance path of the paper P can be opened, so that the jam processing when the conveyance failure occurs such as the paper P being stopped in the middle of the conveyance path becomes easy, and the inside of the apparatus can be maintained. Will also be easier.

Further, according to the present embodiment, the swing unit (moving unit) 50 is made to re-pass the sheet P having passed through the fixing device 30 through the secondary transfer position with its front and back surfaces reversed. It is provided with a transporting means for transporting double-sided image formation. Therefore, images can be formed on both sides of the paper P.

Further, according to this embodiment, the intermediate transfer belt 10 is separated from the plurality of photosensitive drums 1A, 1B, 1C and 1D upward, and the photosensitive member among the constituent elements of the image forming means is formed. The intermediate transfer belt 10 and the facing component are movable so that the facing components (the cleaning device 2, the charging device 3, the developing device 5, and the charge removing device L) facing the surface of the body drum are separated downward. Has been done. Further, each photosensitive drum 1A, 1B, 1
In a state where the intermediate transfer belt 10 and the facing constituent elements are separated from C and 1D, the photosensitive drum 1 is attached to the apparatus main body.
Only A, 1B, 1C and 1D are detachable. Therefore, the photosensitive drum can be replaced not by the process cartridge but by the photosensitive drum alone, and the intermediate transfer belt and the above-mentioned facing components that do not need to be replaced need not be replaced while being left in the apparatus. The physical burden can be reduced. Long-life type with a strengthened surface of the photoconductor drum (for example, type that uses amorphous silicon)
In this case, since there is almost no chance of exchanging the photosensitive drum, it is convenient that the photosensitive drum can be attached and detached separately from other exchange parts and units.

Further, according to this embodiment, the conveyor belt 1
00 and a part of the above-mentioned transport path forming member, a transport belt unit 250U integrally configured is provided. The transport belt unit 250U is attachable to and detachable from the swing unit (moving unit) 50 when the swing unit (moving unit) 50 is moved. Therefore, maintenance work of the transport belt unit 250U becomes easy. As shown in FIG. 6, the transfer belt unit 250U includes a pair of registration rollers 2 as a transfer member.
The blade cleaner 260 may be provided as a cleaning unit that cleans one of the eight rollers 28A. In this case, the blade cleaner 260 can remove foreign matter such as paper dust adhering to the registration roller 28A, so that image loss due to foreign matter such as paper dust adhering to the paper P image is prevented. can do. Further, it is possible to prevent foreign matter such as paper dust from adhering to the fixing roller 30a located on the downstream side in the transport direction and deteriorating the surface thereof. Further, as shown in FIG. 6, a recovery container 260A may be provided as a storage unit for storing foreign matter such as paper dust scraped off by the blade cleaner 260. In this case, by collecting the foreign matter in the collecting container 260A, it is possible to prevent contamination in the image forming apparatus,
The disposal operation can be facilitated.

According to this embodiment, the developing device (5
A, 5B, 5C, 5D) are provided with a plurality of toner cartridges TC for accommodating the toners of the respective colors to be replenished. These toner cartridges TC are arranged between the intermediate transfer belt 10 and the paper receiving surface 42 of the discharge stack section 40 along the upper tension portion of the intermediate transfer belt 10 and the main receiving surface (inclined surface) 42a of the discharge section. It is set up. Therefore, the toner cartridge TC is installed in the intermediate transfer belt 10
Along the upper stretched portion of the recording medium and the recording medium receiving surface 42, by moving to the front side of the device that can be operated by the operator,
The toner cartridge TC can be easily replaced. Moreover, since the heat shield is provided between the toner cartridge mounting portion TS and the fixing device 30 having the heat source,
It is possible to prevent the replenishment toner in the toner cartridge TC from melting and sticking due to repeated heating and cooling.

Further, according to the present embodiment, when the heat shield means is constructed by using the heat insulating member W, the space for the heat shield means is narrow, which is advantageous in that the size of the apparatus can be reduced. is there. Further, the toner cartridge TC itself may be formed of a heat insulating material. In this case, it is not necessary to separately provide a heat insulating member, which is preferable in terms of downsizing of the apparatus.

Further, in the present embodiment, the heat shield means may be constituted by a ventilation means for circulating air between the toner cartridge mounting portion TS and the fixing device 30 having a heat source. In this case, a higher cooling effect can be obtained as compared with the case where only the heat insulating member W is provided.
It is possible to more reliably prevent the toner from being melted and fixed.

Further, according to the present embodiment (the printer of FIG. 1), the intermediate transfer unit 51 including at least the intermediate transfer belt 10 and the supporting rollers 11 and 12 as the supporting members thereof is provided. The intermediate transfer unit 51 is configured to be removable from the printer main body by moving in a direction perpendicular to the surface movement direction of the intermediate transfer belt 10 and along the upper stretched portion of the intermediate transfer belt 10 and the paper receiving surface 42. Has been done. By pulling out the intermediate transfer unit 51 to the front side, maintenance and replacement of the intermediate transfer belt 10 and the like become easy.

Further, according to the present embodiment (printer in FIG. 6), since the predetermined space S1 is provided between the toner cartridge TC and the intermediate transfer belt, the intermediate transfer belt 10 is connected to the photosensitive drums 1A to 1D. The toner cartridge TC and the intermediate transfer belt 10 do not interfere with each other when moved to be separated from 1D. Therefore, the intermediate transfer unit 51
Can be pulled out to the front side to reliably perform maintenance and replacement of the intermediate transfer belt 10 and the like.

Further, according to the present embodiment (printer of FIG. 1), a process including the photosensitive drums 1A and 1B, at least one of the charging device 3, the developing devices 5A, 5B, 5C and 5D, and the cleaning device 2. A cartridge 52 is provided. The process cartridge 52 is perpendicular to the surface moving direction of the intermediate transfer belt 10 and
It is configured such that it can be attached to and detached from the printer main body by moving in the direction along the upper tension portion of 0 and the paper receiving surface 42.
By pulling out the process cartridge 52 to the front side, it becomes possible to easily perform maintenance and replacement of the photosensitive drum and the like. The intermediate transfer unit 51
The process cartridges 52 may be combined into one process cartridge 53 as in the printer of FIG.

Further, according to the present embodiment (printer of FIG. 7), a process cartridge integrally configured to include at least the charging device 3 and the developing devices 5A, 5B, 5C and 5D which constitute the image forming means. (Imaging unit)
54 is provided. This process cartridge 54 is
It is configured such that it can be attached to and detached from the main body of the image forming apparatus independently of the photosensitive drum by the moving mechanism portion of FIG. In this case, it is possible to easily perform maintenance / replacement of the facing components such as the charging device 3 and the developing devices 5A, 5B, 5C, 5D, which face the photoconductor drum, independently of the photoconductor drum.

The process cartridges (image forming units) 52 and 54 are provided in the plurality of photosensitive drums 1A to 1A.
You may provide integrally about all or one part of 1D.
For example, the process cartridge (imaging unit) 5
In the case where the photosensitive drums 1 and 2 are integrally provided on all of the photosensitive drums 1A to 1D, the photosensitive drum 1 can be attached / detached by one operation.
Opposing components such as A to 1D, the charging device 3 and the developing devices 5A, 5B, 5C, and 5D facing them can be collectively attached and detached. Further, process cartridges (image forming units) 52 and 54 for one photoconductor drum for forming a black image and process cartridges (image forming unit) 52 for three photoconductor drums for forming a color image. , 54, it is possible to individually replace only the black process cartridge (image forming unit) that is frequently used.

Further, according to the present embodiment, the toner cartridge TC as the toner accommodating portion is installed in the intermediate transfer belt 1.
It is configured to be attachable to and detachable from the printer main body by moving in the direction perpendicular to the surface movement direction of 0 and along the upper stretched portion of the intermediate transfer belt 10 and the paper receiving surface 42. Therefore,
By pulling out the toner cartridge TC that is empty of toner and replacing the toner cartridge TC or replenishing the toner cartridge TC with toner,
The toner can be easily replenished.

Further, according to the present embodiment (printer of FIG. 8), among the constituent elements constituting the image forming means, the charging device 3 and the developing device 5A, which face the plurality of photosensitive drums 1A to 1D, It is provided with a moving mechanism that moves facing components such as 5B, 5C, and 5D downward. Then, the facing components are moved downward to move the photosensitive drums 1A to 1A.
A space S2 ′ is provided between the facing component and the moving mechanism so that the facing component and the moving mechanism do not interfere with each other when taken out after being separated from D. Therefore, the process cartridge (image forming unit) 54 including the above-described facing components is pulled out to the front side, and the charging device 3 and the developing device 5 are connected.
It is possible to reliably perform maintenance / replacement of the facing components such as A, 5B, 5C and 5D.

Further, according to the present embodiment (printer in FIG. 8), the moving mechanism portion has a contact surface with which the lower end portion of the rail R supporting the facing component contacts from above. A plate cam 60 is used as a cam member that is movable in a direction intersecting the contact direction of the lower end portion of the rail R, and the opposed component is separated from the image forming position and the photoconductor drum by the movement of the plate cam 60. So that it can take the separated position,
The contact surface of the plate cam 60 is formed. By configuring the moving mechanism section using such a plate cam 60,
By a simple operation of reciprocally moving the plate cam 60 in the intersecting direction (horizontal direction), the rail R abutting on the abutting surface of the plate cam 60 is moved up and down, and a process cartridge (manufacturing cartridge) including the facing component is manufactured. The image unit) 54 can be moved between the image forming position and the separated position.

Further, according to the present embodiment (printer in FIG. 8), the moving mechanism section is moved to the intermediate position as the plate cam 60 moves the facing component from the image forming position to the separated position. The transfer belt 10 and its supporting member are configured to be moved from the image forming position to a separating position separated from the photosensitive drum. Specifically, a rotary member having a cam portion 73 provided at one end and an elongated hole 72 as an engaging portion that engages with the pin 63 of the plate cam 60 so as to rotate in conjunction with the plate cam 60. It is configured by using a movable lever member 71. Then, the cam portion 73 of the lever member 71
However, as the lever member 71 rotates, the intermediate transfer belt 10
Also, the support member is formed so as to move between the image forming position and the separated position. in this case,
The intermediate transfer belt 10 and the like are moved between the image forming position and the separated position by a simple operation of reciprocating the plate cam 60 in the intersecting direction (horizontal direction).

Further, according to the present embodiment (printer in FIG. 8), the process cartridge (image forming) including the above-described facing component is formed by a simple operation of rotating the lever member 71 using the knob 71A of the lever member 71. Unit) 5
4, the intermediate transfer belt 10 and the like can be moved between the image forming position and the separated position. The operating portion operated by the operator to rotate the lever member 71 may be formed on the cam portion 73 of the lever member in addition to the knob 71A of the lever member 71. Further, the operation portion may be a protruding portion 60A obtained by protruding the right end portion of the plate cam 60 to the swing unit (moving unit) 50 side. Further, the lever member 71 may be configured to rotate in conjunction with the movement of the swing unit (moving unit) 50 that opens the transport path. In this case, when the swing unit (moving unit) 50 is moved for maintenance of the apparatus, the process cartridge (imaging unit) 54 including the above-mentioned opposing components and the intermediate transfer are moved along with the movement. The belt 10 and the like can be moved from the image forming position to the separated position. Therefore, a separate operation for moving the process cartridge or the like to the separated position becomes unnecessary.

Further, according to the present embodiment (printer in FIG. 8), the movable rail movable in the direction of the rotation axis of the photosensitive drum is attached to the image forming frame 54F as a case member to which the above-mentioned opposing components are attached. A slide rail R'as a member is fixed. After the process cartridge (image forming unit) 54 including the above-described facing components is moved to the separated position by the slide rail R ′ fixed to the image forming frame 54F, the image forming frame 54F is pulled out and the process cartridge (image forming unit). ) 54 can be exposed. Therefore, the charging device 3 and the developing device 5A,
Maintenance and replacement of facing components such as 5B, 5C, and 5D become easier.

In the above embodiment, the case where a plurality of photosensitive drums are provided has been described, but the present invention is applicable without limitation to the number of photosensitive drums as long as an intermediate transfer member is used. It is possible to obtain the same effect. For example, in the present invention, the toner image of each color (magenta, cyan, yellow, black) is formed on one photoconductor drum by using a revolver type developing device or the like, and the primary transfer to the intermediate transfer body is sequentially performed. It is also applicable to such an image forming apparatus.

In the above embodiment, the case where the image forming apparatus is a color printer has been described, but the present invention can be applied to other image forming apparatuses such as a fax machine and a copying machine, and similar effects can be obtained. It is a thing.

[0083]

According to the invention of claims 1 to 34, the trailing edge of the recording medium received by the recording medium receiving surface of the ejecting portion collides with the leading edge of the succeeding recording medium continuously ejected from the ejecting port. Since it is possible to eject a plurality of recording media in a difficult state, defective ejection of recording media can be prevented.
In addition, a dead space is not generated between the intermediate transfer body and the recording medium receiving surface of the ejecting section, and a part of the constituent elements of each image forming unit is made common, thereby saving space inside the apparatus. Since this can be achieved, the device can be downsized. Further, since the internal constituent parts / devices and units can be easily attached / detached, there is an effect that the maintainability of the internal constituent parts / devices and units is excellent.

[Brief description of drawings]

FIG. 1 is a front view showing a schematic configuration of a printer according to an embodiment of the invention.

FIG. 2 is an enlarged view of a discharge stack section of the printer.

FIG. 3 is a partial front view showing a swing unit of the printer which is swinged to an open state.

FIG. 4 is a front view showing a schematic configuration of a printer according to another embodiment.

FIG. 5 is a partial front view showing the swing unit of the printer which is swinged to an open state.

FIG. 6 is a front view showing a schematic configuration of a printer according to another embodiment.

FIG. 7 is a front view of the printer when the moving unit is moved to the open state of the printer.

FIG. 8 is an explanatory diagram of a moving mechanism unit that moves an intermediate transfer unit and an image forming unit.

FIG. 9 is a partial perspective view of the printer with an image forming frame pulled out.

FIG. 10 is a front view of the conveyor belt unit removed from the swing unit.

FIG. 11 is an explanatory diagram of an image forming system using the printer of this embodiment.

FIG. 12 is an explanatory diagram showing how a sheet of paper is discharged in the printer of this embodiment.

FIG. 13 is an explanatory diagram of a paper discharge defect in the image forming apparatus according to the conventional example.

[Explanation of symbols]

1A, 1B, 1C, 1D Photoconductor drum 2 Cleaning device 3 Charging device 4 Exposure device 5A, 5B, 5C, 5D Developing device 10 Intermediate transfer belt 11, 12, 13 Support roller 20 Primary transfer roller 30 Fixing device 30a Heating roller 40 Ejection Stack Section 41 Ejection Port 42 Paper Receiving Surface 42a Sloping Surface (Main Receiving Surface) 50 Swing Unit (Movement Unit) 50A Opening / Closing Shaft 51 Intermediate Transfer Unit 52, 53, 54 Process Cartridge (Imaging Unit) 54F Imaging Frame 60 Plate cam 60A Projection 61 Long hole 62A Sloping surface 62B Horizontal surface 63, 64 Pin 65 Support shaft 71 Lever member 71A Knob 72 Long hole (engaging portion) 73 Cam portion 100 Conveying belt 111, 112, 113 Support roller 120 Secondary Transfer roller 250U Conveyor belt units F1, F2 Fans G1, G2 Switching guide member P Paper PG1, PG2, PG3, PG4 Refeeding conveyance paths R1, R2, R3, R4 Conveying rollers R Rail R'Slide rail TC Toner cartridge W Heat insulating member

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G03G 21/10 G03G 15/00 554 2H200 21/16 556 2H300 21/18 21/00 310 F term (reference) 2H027 JA11 JB12 JB17 JC06 JC08 2H028 BA09 BA16 BD01 2H072 AA32 AB07 BA12 CA02 CA05 CB09 EA18 EA19 JA02 JA03 2H134 GA06 GA08 GB02 GB05 HD01 JB01 JB02 KF05 KH01 KH03 KH12 KJ02 KJ03 2H171 FA03 FA06 FA13 FA15 FA19 FA22 FA28 GA03 GA11 GA12 HA03 JA07 JA08 JA24 JA26 JA29 JA31 KA06 KA10 KA17 KA25 KA29 NA01 QA03 QA08 QA15 QA17 QA19 QA24 QA29 QA30 QB34 QC11 QC12 QC13 QC22 QC24 QC29 SA11 SA14 SA19 SA26 SA32 SA37 TA15 TB13 TB14 UA02 UA03 UA16 UA19 VA01 VA05 WA03 WA08 WA21 2H200 FA12 GA12 GA16 GA23 GA34 GA50 GB01 GB12 GB43 GB44 HB12 HB13 HB22 JB06 JB17 JB39 JB42 JB46 JC03 JC12 JC15 JC17 LA02 LA11 LA24 LA38 LB 02 LB08 LB17 MA02 MA03 MA20 MB05 MC08 2H300 EA01 EA02 EA05 EA06 EA07 EA17 EA19 EB04 EB07 EB08 EB12 EB18 EB24 EC02 EC05 EC09 EC13 ED02 ED05 EJ08 EJ08 EJ08 EJ06 EJ09 EJ09 EJ09 EJ09 EF09 EF09 EF09 EF06 EF09 EF09 EF06 EF09 EF06 EH EL07 FF01 FF08 GG01 GG02 GG03 GG08 GG33 GG35 GG42 GG43 GG46 HH02 HH03 HH12 HH24 HH28 HH40 KK02 KK03 KK04 KK12 KK13 KK14 MM25 NN02 NN04 QQ10 RR12

Claims (34)

[Claims] 1. A plurality of image carriers, image forming means for forming images of different colors on each image carrier, and a plurality of supports so as to pass through a primary transfer position facing each image carrier. An endless belt-shaped intermediate transfer member that is stretched and driven by a member, a primary transfer unit that transfers an image of each color formed on each image bearing member onto the intermediate transfer member in an overlapping manner, and the intermediate transfer member. At a secondary transfer position located on one end side in the horizontal direction of the body, a secondary transfer unit that collectively transfers the image on the intermediate transfer body to a recording medium, and a recording medium that has passed the secondary transfer position. Fixing unit provided above the secondary transfer position so as to fix the image, and the secondary transfer position of the secondary transfer unit and the fixing position of the fixing unit so as to pass upward. A transport means for transporting the recording medium, and a position above the intermediate transfer body. An image forming apparatus comprising: a recording medium receiving surface having a recording medium receiving surface; and a discharge section having a discharge port for discharging the recording medium that has passed through the fixing unit onto the recording medium receiving surface. At least a part of the surface is inclined downward as it approaches the discharge port side, and the lowermost end thereof is formed as a sloped surface lower than the discharge port, and the intermediate transfer member is formed along the sloped surface of the discharge section. The intermediate transfer member is stretched so as to extend obliquely, and the plurality of image bearing members are arranged so as to face the lower stretched portion of the intermediate transfer member. Image forming apparatus. 2. The image forming apparatus according to claim 1, wherein the image forming means is configured to form images of a plurality of different colors on at least one of the image carriers. Image forming apparatus. 3. The image forming apparatus according to claim 1 or 2, wherein said conveying means supports and conveys said recording medium along a conveying path which passes through said secondary transfer position and goes to said fixing position. An image forming apparatus comprising a conveyance belt member stretched by a plurality of support members. 4. The image forming apparatus according to claim 3, wherein the conveyor belt member is formed of a heat resistant material. 5. The image forming apparatus according to claim 3 or 4, wherein the conveyor belt member and a part of the conveyor path forming member constituting the conveyor means can be integrally moved so as to open the conveyor path. Image forming apparatus having a simple moving unit. 6. The image forming apparatus according to claim 5, wherein the moving unit conveys the recording medium, which has passed through the fixing means, so as to re-pass the secondary transfer position with the front and back surfaces thereof reversed. An image forming apparatus comprising: a conveying unit for image formation. 7. The image forming apparatus according to claim 5, wherein when the moving unit is moved so as to open the transport path, the transport belt member and a part of the transport path forming member are included. The image forming apparatus is characterized in that the transport unit integrally configured as described above is attachable to and detachable from the moving unit. 8. The image forming apparatus according to claim 1, wherein the intermediate transfer member and the recording medium receiving surface of the discharge portion are provided to form images of respective colors to be supplied to the image forming means. A plurality of toner accommodating portions for accommodating different toners are arranged in parallel, and a heat shield means for interrupting heat transfer from the fixing means to the toner accommodating portion is provided between the toner accommodating portion and the fixing means. An image forming apparatus characterized by being provided. 9. The image forming apparatus according to claim 8, wherein a heat insulating member is provided as the heat shielding means. 10. The image forming apparatus according to claim 8 or 9, wherein the heat shield means is provided with ventilation means for circulating air between the toner accommodating portion and the fixing means. apparatus. 11. The image forming apparatus according to claim 1, wherein the intermediate transfer member and the recording medium receiving surface of the discharge portion are provided to mutually form an image of each color to be supplied to the image forming means. An image forming apparatus characterized in that a plurality of toner containing portions containing different toners are arranged in parallel, and the toner containing portions are formed of a heat insulating material. 12. The image forming apparatus according to claim 1 or 2, wherein an image of each color to be replenished to the image forming means is formed between the intermediate transfer body and the recording medium receiving surface of the discharge section. A plurality of toner accommodating portions for accommodating different toners are arranged in parallel so that the toner accommodating portion and the intermediate transfer member do not interfere with each other when the intermediate transfer member is moved to separate from the plurality of image bearing members. An image forming apparatus characterized in that a space is provided between the toner accommodating portion and the intermediate transfer member. 13. The image forming apparatus according to claim 8, wherein the toner containing portion is attachable to and detachable from a main body of the image forming apparatus. 14. The image forming apparatus according to claim 1, wherein an intermediate transfer unit integrally configured to include the intermediate transfer body and a supporting member thereof is separated from the image carrier. The image forming apparatus is detachable from the main body of the image forming apparatus. 15. The image forming apparatus according to claim 1, further comprising a charging device, a developing device and a cleaning device for cleaning the surface of the image carrier, the charging device and the image forming means. An image forming apparatus, wherein a process cartridge integrally configured to include at least one is attachable to and detachable from an image forming apparatus main body. 16. An image forming apparatus according to any one of claims 1 to 14, wherein a process cartridge integrally configured to include at least a charging device and a developing device constituting the image forming means is provided from the image carrier. An image forming apparatus, wherein the image forming apparatus can be attached to and detached from an image forming apparatus main body independently of the image carrier in a separated state. 17. The image forming apparatus according to any one of claims 1 to 16, wherein the intermediate transfer member and the image forming member among the constituent elements of the image forming unit are provided with respect to the plurality of image forming members. The intermediate transfer body and the facing component are configured to be movable so as to be separated from the facing component facing to the image carrier, and the intermediate transfer body and the facing component are separated from the image carrier. An image forming apparatus, wherein only the image carrier is detachably attached to the apparatus body. 18. An image forming apparatus according to claim 1, wherein a process cartridge integrally configured to include the image bearing member, the intermediate transfer member, and a supporting member thereof is provided.
An image forming apparatus, which is removable from the main body of the image forming apparatus. 19. The image forming apparatus according to claim 15, 16 or 18, wherein the process cartridge is integrally provided for all or some of the plurality of image carriers. . 20. The image forming apparatus according to claim 1 or 2, further comprising a moving mechanism portion for moving downward a facing constituent element facing the plurality of image carriers among the constituent elements constituting the image forming means. The facing component and the moving mechanism unit are provided so that the facing component and the moving mechanism unit do not interfere with each other when the facing component is moved downward and separated from the plurality of image carriers and then taken out. An image forming apparatus characterized in that a space is provided between and. 21. The image forming apparatus according to claim 20, wherein the moving mechanism portion has an abutting surface with which a lower end portion of a rail member supporting the facing component abuts from above, and A cam member that is movable in a direction intersecting with the contact direction of the lower end portion is used, and by moving the cam member, the facing component can take an image forming position and a separated position separated from the image carrier. An image forming apparatus, wherein an abutting surface of the cam member is formed on the. 22. The image forming apparatus according to claim 21, wherein the moving mechanism moves the cam member to move the facing component from the image forming position to the separated position, and the intermediate transfer member and An image forming apparatus, characterized in that the supporting member is moved from an image forming position to a separating position separated from the image carrier. 23. The image forming apparatus according to claim 22, wherein the moving mechanism portion engages with a cam portion provided at one end thereof and the cam member so as to rotate interlockingly with the cam member. And a cam portion of the lever member for moving the intermediate transfer member and its supporting member between the image forming position and the separated position in accordance with the rotation of the lever member. An image forming apparatus, wherein the image forming apparatus is formed so as to move between the two. 24. The image forming apparatus according to claim 23, wherein the lever member is provided with a knob for an operator to rotate the lever member. 25. The image forming apparatus according to claim 23, wherein the cam portion of the lever member is formed to be operable by an operator so as to rotate the lever member. 26. An image forming apparatus according to claim 23, wherein said conveying means supports and conveys said recording medium along a conveying path passing through said secondary transfer position and heading to said fixing position. The transport belt member is constructed by using a transport belt member stretched by a support member, and the transport belt member and a part of the transport path forming member forming the transport means can be integrally moved so as to open the transport path. An image forming apparatus, comprising: a moving unit, wherein the lever member is configured to rotate in conjunction with movement of the moving unit to open the transport path. 27. An image forming apparatus according to any one of claims 20 to 26, wherein a case member, to which the facing component is attached, is fixed to the case member, and is movable in a direction of a rotation axis of the image carrier. Image forming apparatus including a movable rail member. 28. The transport unit in the image forming apparatus according to claim 7, wherein the transport unit is configured to include the transport belt member and a part of the other transport member, and is moved to open the transport path. A transport unit that is removable from the moving unit. 29. The transport unit according to claim 28, wherein one of the pair of registration rollers is provided as a part of the transport member, and a cleaning means for cleaning the roller is provided. 30. The transport unit according to claim 28, further comprising a storage portion for storing the foreign matter removed by the cleaning means. 31. An intermediate transfer unit in the image forming apparatus according to claim 14, wherein the image forming apparatus is integrally configured to include the intermediate transfer body and its supporting member, and is separated from the image carrier. An intermediate transfer unit that is removable from the main body. 32. A process cartridge for an image forming apparatus according to claim 15, further comprising: the image carrier, a charging device that constitutes the image forming means, a developing device, and a cleaning device that cleans a surface of the image carrier. A process cartridge that is integrally configured to include at least one and is detachable from the main body of the image forming apparatus. 33. The process cartridge in the image forming apparatus according to claim 16, wherein the process cartridge is integrally configured to include at least a charging device and a developing device that form the image forming means, and is separated from the image carrier. The process cartridge is detachable from the main body of the image forming apparatus independently of the image carrier. 34. The process cartridge in the image forming apparatus according to claim 18, wherein the process cartridge is integrally configured to include the image bearing member, the intermediate transfer member and a supporting member thereof, and the image forming apparatus main body is provided. A process cartridge that is removable.