JP2004334247A - Image formation apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a color printer that can prevent defects in transporting forms and defects of discharge, can be made small-sized without forming any dead space between an intermediate transfer belt and a discharge part for form, and has superior maintainability of internal constituent components, the device, and units. <P>SOLUTION: This image forming apparatus is constituted so that a form P is carried so as to passes upward a secondary transfer position and a fixation position of a fixing device 30, at least a portion of a form receiving surface 42 of a discharge stack part 40 slants down toward a discharge opening 40, and its bottom end is formed of a tilt surface lower than the discharge opening 41, the upper extension part of an intermediate transfer belt 10 extends obliquely along the form receiving surface 42 of a discharge stack part 409 and photoreceptor drums 1A and 1B are arranged opposite to the lower extension part of the intermediate transfer drum 10. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an image forming apparatus such as a copying machine, a printer, and a facsimile, and a transport unit, an intermediate transfer unit, and a process cartridge used in the apparatus. More 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.

2. Description of the Related Art Conventionally, a tandem type color image forming apparatus in which four photosensitive drums as image carriers are arranged side by side along a stretched portion of an endless belt-shaped intermediate transfer body stretched in a horizontal direction (see, for example, Japanese Patent Application Laid-Open No. H11-157556). For example, see Patent Document 1). In this image forming apparatus, toner images of different colors are formed on four photosensitive drums, and the primary transfer is performed such that the toner images on the respective photosensitive drums are superimposed on the intermediate transfer member. Then, the toner image superimposed on the intermediate transfer member is collectively transferred to a sheet as a recording medium. The sheet that has passed through the secondary transfer position is discharged onto a sheet receiving surface (recording medium receiving surface) through a discharge port of a discharge unit located above the intermediate transfer member after an image is fixed by a fixing unit. .
Further, in a sheet receiving surface of a discharge unit (see FIG. 13) of the image forming apparatus described in Patent Document 1, a portion far from the discharge port is formed as a horizontal flat portion. The portion close to the discharge port is formed by a convex curved portion that gradually becomes curved and becomes lower as approaching the discharge port. The toner cartridges of the respective colors are horizontally arranged below the horizontal flat portion of the sheet receiving surface, and further below the toner cartridges, the support members are arranged such that the upper stretch portion extends in the horizontal direction. A stretched intermediate transfer member is arranged.

JP 2001-117384 A JP 2001-209232 A

  However, in an image forming apparatus having a discharge unit as described in Patent Document 1, when an image is formed on a sheet such as a thick and thick cardboard or an OHP sheet and discharged to the discharge unit, the following problem occurs. As a result, there is a risk that defective discharge may occur. In the case of using paper such as thick paper or an OHP sheet, as shown in FIG. 13, the rear end portion PT of the paper P moves along the slope curve portion 401 a of the recording medium receiving surface 401 due to the strength (rigidity) of the paper P. It will be lifted up without bending. Further, even when the sheet P curls in a direction perpendicular to the sheet discharging direction, the rear end portion PT of the sheet P is lifted upward without bending along the inclined curved portion 401a of the sheet receiving surface 401. When the trailing end portion PT of the sheet P discharged onto the sheet receiving surface 401 of the discharging unit 400 is lifted upward, the trailing end portion of the succeeding sheet discharged to the discharging unit subsequently hits. For this reason, there is a possibility that a paper discharge failure may occur.

On the other hand, the above-described conventional image forming apparatus includes a plurality of sets of image forming means such as a photosensitive drum and an associated charging device, and an endless belt-shaped intermediate transfer member stretched over a plurality of supporting members. In such a case, the entire apparatus tends to be large. Therefore, it has been particularly desired to reduce the size of the apparatus while minimizing the dead space in the apparatus.
However, in an image forming apparatus having the plurality of photosensitive drums and the intermediate transfer member, if internal components, devices, and units are arranged so as to eliminate dead space in the apparatus main body in order to reduce the size of the apparatus, the There has been a problem that the exchangeability of internal components, devices and units constituting the image forming means including the drum and the intermediate transfer member is sacrificed, and the maintainability is sometimes reduced. For example, in Japanese Patent Application Laid-Open No. H10-157, there is a configuration in which three photosensitive drums for color toner are opposed to an upper stretch portion of an intermediate transfer body (intermediate transfer belt), and a black photosensitive drum is opposed to a lower stretch portion. Described image forming apparatus. In order to replace the central intermediate transfer member in this image forming apparatus, the upper photosensitive drum for color toner and its associated components are moved upward and retracted, and the lower photosensitive drum for black and Since it is necessary to move the accompanying components downward and retract, the maintainability is poor.

  SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to prevent a recording medium from being transported and ejected defectively, and to reduce a space by reducing a dead space in the apparatus. An object of the present invention is to provide an image forming apparatus which can be reduced in size and which is excellent in maintainability of internal components, devices and units, and a transport unit, an intermediate transfer unit and a process cartridge used in the device.

In order to achieve the above object, the invention according to claim 1 includes a plurality of image carriers, an image forming means for forming images of different colors on each image carrier, and a primary device opposed to each image carrier. An endless belt-shaped intermediate transfer body that is stretched and driven by a plurality of support members so as to pass through a transfer position, and images of each color formed on each image carrier are superimposed and transferred onto the intermediate transfer body. A primary transfer unit that performs a batch transfer of an image on the intermediate transfer body to a recording medium at a secondary transfer position located at one end side of the intermediate transfer body in the horizontal direction; A fixing unit provided above the secondary transfer position so as to fix the image on the recording medium passing through the secondary transfer position; and a secondary transfer position in the secondary transfer unit and a fixing position in the fixing unit. Conveying the recording medium so as to pass upward An image forming apparatus comprising: a step; and a discharge unit having a recording medium receiving surface positioned above the intermediate transfer body and 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 recording medium receiving surface of the discharge section is inclined downward as approaching the discharge port side, and the lowermost end thereof is formed with a lower inclined surface than the discharge port, and the intermediate transfer is performed. The intermediate transfer member is stretched so that the body extends obliquely along the inclined surface of the discharge portion, and the plurality of image bearing members are opposed to a lower stretch portion of the intermediate transfer member. The body is arranged.
In the image forming apparatus according to the first aspect, at least a part of the recording medium receiving surface of the discharge section is inclined downward as approaching the discharge port side, and the lowermost end thereof is a lower slope than the discharge port. Therefore, the recording medium discharged from the discharge port can be received on the recording medium receiving surface having the above-mentioned inclined surface in a state where the rear end is inclined so as to be lower than the discharge port. Therefore, a plurality of recording media can be discharged in a state where the rear end of the recording medium received on the recording medium receiving surface does not easily collide with the leading end of the subsequent recording medium continuously discharged from the discharge port.
Here, if the intermediate transfer member positioned below the recording medium receiving surface having the inclined surface of the discharge unit is stretched in the horizontal direction, the space between the inclined surface of the recording medium receiving surface and the intermediate transfer member is increased. Becomes 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 unit are brought close to each other, so that a dead space does not occur between them.
Further, a plurality of image carriers are arranged so as to face the lower stretch portion of the intermediate transfer body. Thereby, a plurality of image forming means for each image carrier can be collectively arranged below the lower stretch portion of the intermediate transfer body, and each image forming means is arranged at a relatively close position. Become. Therefore, unlike the case where the image forming means is provided separately on the upper stretching portion side and the lower stretching portion side of the intermediate transfer member, some of the components constituting each image forming device can be shared. Further, the space inside the apparatus can be further reduced. Further, since a plurality of image forming means for each image carrier can be collectively disposed below the lower stretching portion of the intermediate transfer member, internal components such as the intermediate transfer member and the image carrier, or the intermediate transfer member. When replacing a unit such as a unit or a process cartridge, only the lower stretch portion of the intermediate transfer member may be retracted so as to separate the image carriers. Therefore, attachment and detachment of internal components and units are facilitated as compared with the case where a plurality of image carriers are arranged so as to face both the upper stretching portion and the lower stretching portion of the intermediate transfer member.
According to a second aspect of the present invention, in the image forming apparatus of the first aspect, the image forming unit is configured to form images of a plurality of 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 transport unit supports and transports the recording medium along a transport path that passes through the secondary transfer position to the fixing position. As described above, the present invention is characterized by using a transport belt member stretched by a plurality of support members.
According to a fourth aspect of the present invention, in the image forming apparatus of the third aspect, the transport belt member is formed of a heat-resistant material.
According to a fifth aspect of the present invention, in the image forming apparatus of the third or fourth aspect, the transport belt member and a part of a transport path forming member constituting the transport unit are integrally formed so as to open the transport path. A mobile unit is provided, which is movable.
According to a sixth aspect of the present invention, in the image forming apparatus of the fifth aspect, the moving unit conveys the recording medium having passed through the fixing unit so as to re-pass the secondary transfer position in a state where the recording medium is turned upside down. And a conveying means for forming a double-sided image.
According to a seventh aspect of the present invention, in the image forming apparatus of the fifth or sixth aspect, 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 moved. And a transfer unit integrally configured to include the transfer unit is detachable from the moving unit.
According to an eighth aspect of the present invention, in the image forming apparatus of the first or second aspect, an image of each color to be supplied to the image forming means is formed between the intermediate transfer body and a recording medium receiving surface of the discharge section. A plurality of toner storage sections for storing different toners are arranged side by side, and a heat shield between the toner storage section and the fixing section for blocking heat transfer from the fixing section to the toner storage section. Means are provided.
According to a ninth aspect of the present invention, in the image forming apparatus of the eighth aspect, a heat insulating member is provided as the heat shielding means.
According to a tenth aspect of the present invention, in the image forming apparatus according to the eighth or ninth aspect, a ventilation means for circulating air between the toner container and the fixing means is provided as the heat shielding means. Things.
According to an eleventh aspect of the present invention, in the image forming apparatus of the first or second aspect, an image of each color to be supplied to the image forming means is formed between the intermediate transfer body and a recording medium receiving surface of the discharge unit. A plurality of toner accommodating portions accommodating different toners are arranged in parallel, and the toner accommodating portions are formed of a heat insulating material.
According to a twelfth aspect of the present invention, in the image forming apparatus of the first or second aspect, an image of each color to be supplied to the image forming means is formed between the intermediate transfer body and a recording medium receiving surface of the discharge unit. A plurality of toner storage sections for storing different toners are arranged side by side, and when the intermediate transfer body is moved to separate from the plurality of image carriers, the toner storage section and the intermediate transfer body do not interfere with each other. Thus, a space is provided between the toner storage section and the intermediate transfer body.
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 section is detachable from the image forming apparatus main body.
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 support member thereof is separated from the image carrier. It is characterized in that it can be attached to and detached from the image forming apparatus main body in a state in which it is mounted.
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, a developing device, and a cleaning device for cleaning a surface of the image carrier are included in the image forming unit. A process cartridge integrally configured to include at least one of the apparatuses is detachable from the image forming apparatus main body.
According to a sixteenth aspect of the present invention, in the image forming apparatus according to any one of the first to fourteenth aspects, the process cartridge integrated so as to include at least a charging device and a developing device constituting the image forming means is provided with the image bearing device. It is characterized in that it can be attached to and detached from the image forming apparatus main body independently of the image carrier while being separated from the body.
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 intermediate transfer member and the image forming element of the image forming means are provided for the plurality of image carriers. The intermediate transfer member and the opposing component are configured to be movable so as to separate the opposing component opposing the carrier, and the intermediate transfer member and the opposing component are separated from the image carrier. In this state, only the image carrier is detachably attached to 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 carrier, the intermediate transfer body, and a supporting member thereof, It is characterized by being detachable from the forming apparatus body.
According to a nineteenth aspect of the present invention, in the image forming apparatus of the fifteenth, sixteenth, or eighteenth aspect, the process cartridge is provided integrally for all or a part of the plurality of image carriers. It is.

According to a twentieth aspect of the present invention, in the image forming apparatus according to the first or second aspect, a moving mechanism for moving a facing component facing the plurality of image carriers among components constituting the image forming unit downward. A moving unit for moving the opposing component downward so as to separate the opposing component from the plurality of image carriers and removing the opposing component from the plurality of image carriers. It is characterized in that a space is provided between the mechanism part.
According to a twenty-first aspect of the present invention, in the image forming apparatus according to the twentieth aspect, the moving mechanism has a contact surface with which a lower end of a rail member supporting the opposing component abuts from above. A cam member movable in a direction intersecting with the contact direction of the lower end of the member is used. By movement of the cam member, the opposed component takes an image forming position and a separated position separated from the image carrier. A contact surface of the cam member is formed so as to obtain the cam member.
According to a twenty-second aspect of the present invention, in the image forming apparatus according to the twenty-first aspect, the intermediate transfer is performed by moving the cam member that moves the moving mechanism from the image forming position to the separation position. The body and its supporting member are 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 is engaged with the cam member provided at one end and the cam member so as to rotate in conjunction with the cam member. A rotatable lever member having an engaging portion that engages with the cam member of the lever member to separate the intermediate transfer body and its supporting member from the image forming position and the image forming position with the rotation of the lever member. It is formed so as to be moved between positions.
According to a twenty-fourth aspect of the present invention, in the image forming apparatus of 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 present invention, in the image forming apparatus of the twenty-third aspect, the cam portion of the lever member is formed so as to be operable by an operator 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 transporting means supports and transports the recording medium along a transport path that passes through the secondary transfer position to the fixing position. The transport belt member is configured using a transport belt member stretched by a plurality of support members, and the transport belt member and a part of a transport path forming member constituting the transport unit are integrally formed so as to open the transport path. A movable unit is provided, and the lever member is configured to rotate in conjunction with the 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 twentieth to twenty-sixth aspects, a case member to which the facing component is attached, and A movable rail member that is movable.

The invention of claim 28 is the transport unit in the image forming apparatus of claim 7, wherein the transport unit is configured to include the transport belt member and a part of the other transport member so as to open the transport path. It is characterized by being detachable from the moved moving unit.
According to a twenty-ninth aspect of the present invention, in the transport unit of the twenty-eighth aspect, the transport unit includes one of the pair of registration rollers as a part of the transport member, and a cleaning unit that cleans the roller. is there.
According to a thirtieth aspect of the present invention, in the transport unit of the twenty-eighth aspect, there is provided a storage unit for storing the foreign matter removed by the cleaning means.
According to a thirty-first aspect of the present invention, there is provided the intermediate transfer unit in the image forming apparatus according to the fourteenth aspect, wherein the intermediate transfer unit and the supporting member are integrally formed so as to include the intermediate transfer body, and the image is separated from the image carrier. It is characterized by being detachable from the forming apparatus body.
The invention according to claim 32 is the process cartridge in the image forming apparatus according to claim 15, wherein the image carrier, a charging device and a developing device constituting the image forming means, and a cleaning device for cleaning the surface of the image carrier. The image forming apparatus is integrally formed so as to include at least one of the apparatuses, and is detachable from the image forming apparatus main body.
A thirty-third aspect of the present invention is the process cartridge in the image forming apparatus of the thirteenth aspect, wherein the process cartridge is integrated with a charging device, a developing device, and a cleaning device for cleaning a surface of the image carrier, which form the image forming means. The image carrier is detachable from the image forming apparatus main body independently of the image carrier while being separated from the image carrier.
According to a thirty-fourth aspect of the present invention, there is provided a process cartridge in the image forming apparatus according to the eighteenth aspect, wherein the process cartridge is integrally formed so as to include the image carrier, the intermediate transfer body and a supporting member thereof, and It is characterized in that it can be attached and detached.

  According to the inventions of claims 1 to 34, the rear end of the recording medium received on the recording medium receiving surface of the discharge unit is set in a state in which the rear end of the recording medium is unlikely to collide with the front end of the subsequent recording medium continuously discharged from the discharge port. Since the recording medium can be ejected, defective ejection of the recording medium can be prevented. In addition, by eliminating some dead space between the intermediate transfer body and the recording medium receiving surface of the discharge unit, and by using some of the components constituting each image forming unit in common, space saving inside the apparatus can be achieved. Therefore, the size of the apparatus can be reduced. Further, since attachment / detachment of the internal components / devices / units becomes easy, there is an effect that the maintainability of the internal components / devices / units is excellent.

  Hereinafter, an embodiment in which the present invention is applied to a color printer (hereinafter, referred to as a “printer”) as an image forming apparatus will be described.

FIG. 1 is a front view illustrating a schematic configuration of the printer according to the present embodiment. This printer includes two photosensitive drums 1A and 1B as image carriers. A charge removing device L, a cleaning device 2, a charging device 3, and two developing devices 5A and 5B are arranged on the outer peripheral portion of the first photosensitive drum 1A. The photosensitive drum 1A is rotatably supported, and rotates in the direction of the arrow in the figure. Light emitted from the lower exposure device 4 enters between the charging device 3 and the developing device 5B, and optical information is written. The components around the second photosensitive drum 1B are the same as those of the first photosensitive drum 1A. Further, in each of the developing devices 5A, 5B, 5C, and 5D, toner as a developer of a different color is used. These developing devices 5A, 5B, 5C, and 5D can move in the directions of arrows in the drawing, respectively, and have mechanisms (not shown) for moving toward and away from the corresponding photosensitive drums 1A and 1B.
Here, an image forming means for forming a toner image on the photosensitive drums 1A, 1B is constituted by the charging device 3, the exposing device 4, the developing devices 5A, 5B, 5C, 5D and the like. The photosensitive drum 1, the cleaning device 2, the charging device 3, the developing devices 5A, 5B, 5C, 5D, and the like are integrally formed as a process cartridge 52 that is detachable from the apparatus main body. Can be replaced.

The two photosensitive drums 1A and 1B are partially in contact with an endless belt-shaped intermediate transfer member (hereinafter, referred to as "intermediate transfer belt") 10 at the primary transfer position. The intermediate transfer belt 10 is supported and stretched between supporting rollers 11 and 12 as rotating supporting members so as to be movable in the direction of the arrow in the drawing. On the back side (inside of the loop) of the intermediate transfer belt 10, near the photosensitive drums 1A and 1B, a primary transfer roller 20 as a primary transfer unit and a backing roller 14 are provided so as to be in contact with each other. A cleaning device 25 for an intermediate transfer body is provided on the outer peripheral surface side of the intermediate transfer belt 10. The intermediate transfer body cleaning device 25 wipes off unnecessary toner remaining on the surface of the intermediate transfer belt 10 after the secondary transfer of the toner image to the paper P as a recording medium, and cleans it. 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 or separates from the surface of the intermediate transfer belt 10 by a contact / separation mechanism (not shown).
Further, the intermediate transfer belt 10 and the cleaning device 25 for the intermediate transfer body 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 known laser type exposure device, and applies a laser beam whose intensity is controlled based on image information corresponding to full-color image formation to the surfaces of uniformly charged photosensitive drums 1A and 1B. Irradiation forms an electrostatic latent image. As the exposure device 4, a combination of a known LED array and image forming means can be used.

  The photoreceptor drums 1A and 1B each have an aluminum cylinder having a diameter of about 40 to 100 mm provided with a layer of an organic semiconductor as a photoconductive substance. Note that a belt-shaped photoconductor may be used as the image carrier. It is also possible to use a photosensitive drum of a type using 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 each of the photosensitive drums 1A and 1B. The intermediate transfer belt 10 used in the present embodiment is obtained by applying a low surface energy coat as a surface layer on a base made of a resin film or rubber having a thickness of 50 μm to 500 μm. The volume resistivity of the entire belt of the intermediate transfer belt 10 is in the range of 10 ⁵ to 10 ¹² Ωcm, and 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 conveyance belt 100 is disposed as a belt member that constitutes a recording medium conveyance unit. The transport 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. On the back side (inside of the loop) of the transport belt 100, a secondary transfer roller 120 as secondary transfer means is disposed near the support roller 11 that supports the intermediate transfer belt 10. A backing roller 115 for pressing the conveyor belt 100 against the support roller 11 is also provided. A transfer nip in which the intermediate transfer belt 10 and the conveyor belt 100 contact with a predetermined nip width at the secondary transfer position by the secondary transfer roller 120, the backing roller 115, and the support roller 11 that supports the intermediate transfer belt 10. A part is formed.

  On the outer peripheral surface side of the transport belt 100, a transport belt cleaning device 250 provided with a blade 250B for wiping dust and unnecessary toner adhered to the surface of the transport belt 100 is provided. The dust and waste toner removed by the cleaning device 250 are transported to a collection unit (not shown) by the toner transport unit 250C.

  The transport belt 100 and the transport belt cleaning device 250 are integrally configured as a transport belt unit (transport unit) 250U. The transport belt unit 250 </ b> U is swung about a rotation fulcrum C by a drive mechanism (not shown) so that the transport belt 100 can be moved toward and away from the intermediate transfer belt 10.

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

  The fixing device 30 includes a heating roller 30a having a built-in heat source such as a heater, and fixes the image on the sheet P by transporting the sheet P on which the toner image has been secondarily transferred while holding the sheet P with the heating roller 30a. be able to. Since the fixing device 30 is disposed so as to be located above the printer, heat is less likely to be trapped in the device, and a decrease in reliability due to a rise in temperature can be prevented.

  The paper P is stored in paper feeding devices (paper feeding cassettes) 26-1 and 26-2 set at the lower part of the printer. Then, the uppermost sheet P is conveyed one by one by the sheet feeding roller 27 to the position of the registration roller pair 28 via the guide member 29 as a plurality of conveying path forming members.

  At the upper part of the printer, in addition to the fixing device 30, there are disposed paper discharge guide members 31A and 31B, a paper discharge roller pair 32, and a paper discharge stack unit 40 as a paper discharge unit.

The discharge stack section 40 has a discharge port 41 for discharging the sheet P that has passed through the fixing device 30 and is guided by the discharge guide members 31A and 31B and sent out by the discharge roller pair 32. Further, the paper discharge stack unit 40 has a paper receiving surface 42 as a recording medium receiving surface for receiving the paper P discharged from the discharge port 41 as shown by an arrow A in the drawing. The main receiving surface 42a, which is a part of the sheet receiving surface 42, is inclined downward at a constant inclination angle as approaching the outlet 41 side, and has a flat inclined surface whose lower end is lower than the outlet 41. (See FIG. 2).
The intermediate transfer belt 10 is stretched by support rollers 11 and 12 such that an upper stretch portion of the intermediate transfer belt 10 extends obliquely along a main receiving surface 42 a which is an inclined surface of the discharge stack portion 40. I have.

  A toner cartridge mounting portion TS is provided above the intermediate transfer belt 10 and below the sheet receiving surface 42 of the sheet discharge stack portion 40, and serves as a toner storage portion that can store toner for replenishment supplied to the developing device. Is detachably mounted. The toner cartridge TC is provided for each toner of four colors (magenta, cyan, yellow, and black: a, b, c, and d in the drawing). The toner in each toner cartridge is supplied to a developing device of a 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 main body. The door D is configured to be openable about a vertical rotation shaft (not shown) provided at the left end as a rotation center. This rotation axis is on the right side of the operation panel OP (see FIG. 6 described later), and even when the door D is opened, the information displayed on the operation panel OP and the inside of the sheet cassette are viewed from the operation position in front. It has become possible.

A heat insulating member W is disposed between the toner cartridge mounting portion TS on which the toner cartridge TC is mounted and the fixing device 30 having a heat source as a heat shield. The heat insulating member W prevents transmission of heat from the fixing device 30 to the toner cartridge mounting portion TS, and prevents the toner for replenishment in the toner cartridge TC from being melted and fixed by repeated heating and cooling. As the heat insulating member W, for example, a resin, a planted resin, a material obtained by laminating these materials to have an air layer, or the like can be used.
Further, a ventilation means for circulating air between the toner cartridge mounting portion TS and the fixing device 30 may be provided as the heat shielding means. As shown in FIG. 1, the ventilation means includes a fan F2 attached to the side plate of the printer main body and an air flow passage passing between the toner cartridge mounting portion TS and the fixing device 30 and reaching the fan F2. Can be configured. When the outside air is taken in by this ventilation means, its surroundings are cooled, which is more effective. Further, of the toner cartridge TC, a toner cartridge d particularly close to the fixing device 30 may be formed of a heat insulating material, and a portion of the toner cartridge mounting portion TS where 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 conveyance path of the paper P is opened, and the jam clearance when the conveyance failure of the paper P occurs is facilitated. Further, by opening the swing unit 50, it is easy to take out the transport belt unit 250U including the transport belt 100 described above.

  A fan F1 that operates so as to exhaust air to the outside of the apparatus in order to prevent the temperature inside the apparatus from rising excessively is provided above the swinging unit 50. Further, on the left side of the printer body, there are provided electrical equipment / control devices E1 and E2 including a low-voltage power supply, a high-voltage power supply and a board.

In addition to the transport belt 100, the swing unit 50 transports the sheet P that has passed through the fixing device 30 so that the sheet P passes through the secondary transfer position again with the front and back surfaces reversed. Transportation means is provided. The conveying means for forming a double-sided image includes a switching guide member G1 swingable about a rotation axis G0, a film-shaped switching guide member G2, conveying paths PG1, PG2, PG3, PG4 for re-feeding, conveying rollers. R1 to R4 and the like.
When forming an image on both sides of the sheet P, first, an image is formed on one side of the sheet P. After being fixed by the fixing device 30, the sheet P guided by the switching guide member G1 is held by the transport roller R1 so as to press the film-shaped guide member G2, and is then moved to the re-feeding transport path PG1. Along, go down. After the rear end has passed the guide member G2, the transport roller R1 rotates in the reverse direction while being held by the transport roller R1. The sheet P enters under the guide member G2, the rear end side is now the front end, is conveyed by the conveying rollers R2, R3, R4, and is conveyed to the re-feeding conveyance paths PG2, PG3, PG4. Along the way, it reaches the registration roller 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 sheet P.

  When normal image formation is performed in the printer having the above configuration, first, toner image formation on the photosensitive drums 1A and 1B and transfer to the intermediate transfer belt 10 are performed. During this time, the transport belt unit 250U is swung about the fulcrum 250C so that the transport belt 100 is separated from the intermediate transfer belt 10.

In the toner image forming operation on the photosensitive drums 1A and 1B, light from an LD (semiconductor laser) light source (not shown) of the exposure device 4 is uniformly charged by the charging device 3 through optical components such as a polygon mirror. Irradiated on the surface of the photosensitive drum 1A. By this irradiation, an electrostatic latent image corresponding to the write information (information corresponding to the 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 exposed so that a normal electrostatic latent image is formed. Thus, the image transferred to the sheet P via the intermediate transfer belt 10 becomes a normal image.
The magenta electrostatic latent image on the photosensitive drum 1A moves to a position where the developing device 5A containing magenta toner can develop, and is developed. The toner image (visible image) of the magenta toner is primarily transferred onto the surface of the intermediate transfer belt 10 that moves in synchronization with the photosensitive drum 1A by the primary transfer roller 20. After the primary transfer, the surface of the photosensitive drum 1A is cleaned of the remaining toner by the cleaning device 2, and the charge is removed 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 the surface, and moves in the direction of the arrow. On the surface of another photosensitive drum 1B, optical information to be developed in yellow is written to form an electrostatic latent image for yellow, which is developed by a developing device 5C containing yellow toner. You. This yellow toner image is superimposed on the magenta toner image already formed on the intermediate transfer belt 10.

  When the two color (magenta and yellow) toner images move to the photosensitive drum 1A together with the intermediate transfer belt 10, optical information corresponding to black is written to the photosensitive drum 1A in synchronization with the black. An electrostatic latent image is formed. This 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 primary-transferred onto the surface of the intermediate transfer belt 10 as a third color in the same manner as described above. Optical information to be developed in cyan is written on the surface of the other photosensitive drum 1B to form an electrostatic latent image for cyan, which is developed by a developing device 5D containing cyan toner. You. This cyan toner image is superimposed on the three color toner images 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 case of 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 each of the photosensitive drums 1A and 1B.

  When the intermediate transfer belt 10 rotates and moves to a predetermined position, sheet feeding from the sheet feeding device (sheet feeding cassette) 26 is started. 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 transported to 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 to one surface of the sheet P sent between the intermediate transfer belt 10 and the transport belt 100 via the registration roller pair 28. At this time, the intermediate transfer belt 10 and the transport 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 such that the position of the image becomes a regular position.

  In the present embodiment, the polarity of the toner of the image formed on the photosensitive drums 1A and 1B is negative. Accordingly, by applying a positive charge to the primary transfer roller 20, the toner formed on the photosensitive drums 1A and 1B is transferred to the intermediate transfer belt 10. 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 sheet P.

  The sheet P on which the toner image has been transferred to the front surface in the above process is sent to a certain area of the fixing device 30, and the toner images (both sides) on the sheet P are fixed at a time. Then, the sheet is discharged from the discharge port 41 to the sheet receiving surface 42 of the sheet discharge stack section 40 provided at the upper part of the main body frame by the discharge roller pair 32 via the guide members 31A and 31B.

  Dirt and toner adhering to the conveyor belt 100 after the secondary transfer are scraped off by the cleaning blade 250B and collected by the toner conveyor 250C in a storage unit (not shown).

  When a single-color image is formed instead of a full-color image by the printer having the above-described configuration, a secondary transfer process to the sheet P is performed without rotating the intermediate transfer belt 10 twice, and the traveling distance of the intermediate transfer belt 10 Can be shortened.

  In the printer having the above configuration, control commands such as various parameter settings from the operator can be issued from an operation panel OP shown in FIG. 5 described later or a keyboard of the host computer HC. When performing image formation on both sides of the sheet P, the image can be selected by a double-sided button (not shown) provided on the operation panel (OP). The selection of the special paper and the selection of the paper feed cassette 26 can be selected by a setting button for the paper feed button. In a system in 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 setting instructions can be given on the screen. .

In the printer having the above-described configuration, the heat energy applied to the sheet P by the fixing device 30 may be smaller when forming a single-color image than when forming a full-color image. For this reason, at the time of forming a monochrome image, for example, control is performed such as reducing or not applying power to a heat source located on the side where no image is present.
Further, in a case where double-sided image formation in which images are formed on both sides of the sheet P is performed, even-numbered page images are formed first, and odd-numbered page images are formed next. The odd pages are placed on the lower surface 42. Therefore, when the paper P is removed from the paper discharge stack unit 40, the page order is uniform, which is advantageous. When double-sided image formation is performed, the rear end of the sheet P on which an image is formed on one side when the sheet P is fed again enters the secondary transfer position as the front end. I do. Therefore, the formation of the electrostatic latent image for the second surface on the photosensitive drums 1A and 1B is controlled so as to be created from the side corresponding to the rear end.

FIG. 4 is a front view illustrating 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 described above.
The printer shown in FIG. 4 is not a laser type exposure apparatus used in the printer shown in FIG. 1, but an exposure apparatus 4 comprising an LED array provided independently for each photosensitive drum in order to further reduce the size of the apparatus. Is used.
Further, in the printer of FIG. 4, in order to reduce the size of the intermediate transfer belt 10 in the left-right direction while securing a predetermined circumferential length, the shape of the traveling path of the intermediate transfer belt 10 is set to be triangular. The supporting rollers 11, 12 and 13 are stretched. The photosensitive drums 1A and 1B are arranged side by side so as to face the outer peripheral surface of a lower stretching portion of the intermediate transfer belt 10 extending in the horizontal direction. Further, in the printer of FIG. 4, the size in the left-right direction in the figure is reduced without providing a conveyance unit for forming a double-sided image, thereby achieving miniaturization.
Further, in the printer shown in FIG. 4, the process cartridge 53 can be replaced when its life has expired. In the process cartridge 53, the intermediate transfer belt 10 and the cleaning device 25 thereof are integrally formed with the photosensitive drums 1A and 1B, the cleaning device 2, the charging device 3, the exposure device 4, and the developing devices 5A, 5B, 5C and 5D. It is detachable from the device body.

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

FIG. 6 is a front view illustrating 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 described above.
The printer of FIG. 6 is a so-called tandem type color image forming apparatus provided with four photosensitive drums 1A, 1B, 1C and 1D, different from the printer shown in FIG. The image forming section provided with each photosensitive drum includes a charging device 3, a developing device 5, a neutralizing device L, and a cleaning device 2 as opposed components around the photosensitive drum. Each of the photosensitive drums 1A, 1B, 1C, 1D is irradiated with light information by a laser beam of color data branched from a multi-beam type exposure device 4 commonly used in each image forming section.
Further, in the printer of FIG. 6, in order to reduce the size of the intermediate transfer belt 10 in the thickness direction at the left end portion in the figure while securing a predetermined circumferential length, the shape of the traveling path of the intermediate transfer belt 10 is triangular. Are stretched around three support rollers 11, 12, and 13. The photosensitive drums 1A, 1B, 1C, 1D are arranged obliquely so as to face the outer peripheral surface of the lower stretch portion of the intermediate transfer belt 10. Further, in the printer of FIG. 6, the transfer unit 50 is not provided with a conveyance unit for forming a two-sided image, and the size in the left-right direction in the figure is reduced to further reduce the size.

  In the printer of FIG. 6, the intermediate transfer unit 51 including the intermediate transfer belt 10 and the cleaning device 25 are rotated in the clockwise direction indicated by an arrow E in FIG. Can be rocked. Thus, the intermediate transfer belt 10 can be separated from the photosensitive drums 1A, 1B, 1C, 1D.

  Further, the photoconductor cleaning device 2, the charging device 3, the static eliminator L and the developing device 5, which are the components constituting the image forming means for each photoconductor drum, are all in the form of a process cartridge (not shown) while a proper positional relationship is secured. The image forming unit is integrally formed and housed in the image forming frame 54F. Then, as the rails R as the two right and left rail members of the image forming frame 54F descend, the opposing components such as the respective charging devices 3 constituting the image forming means become photosensitive drums 1A, 1B, 1C, and 1C. It can be separated from 1D. With the intermediate transfer unit 51 including the intermediate transfer belt 10 and the image forming frame 54 containing the components of the image forming means separated from the photosensitive drum in this manner, each of the intermediate transfer unit 51 is pulled out toward the paper of FIG. I can do it. Then, in this separated state, the photosensitive drums 1A to 1D can be individually pulled out from their shafts 1 ', so that the photosensitive drums 1A to 1D can be easily replaced at the end of their life.

The stretch 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 stretch portion of the intermediate transfer belt 10 and the toner cartridge TC are as follows. Is set. As described above, when the photosensitive drum is attached or detached, the intermediate transfer unit 51 is swung. Therefore, during the swinging of the intermediate transfer unit 51, the stretched shape of the intermediate transfer belt 10 and the upper portion of the intermediate transfer belt 10 are controlled so that the upper stretched portion between the support rollers 11 and 12 of the intermediate transfer belt 10 does not contact the toner cartridge TC. 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 attaching or detaching the photosensitive drum or performing maintenance on the charging device or the like, the image forming frame 54F containing the charging device 3 or the like is moved downward. Therefore, the size of the gap S2 in the lower space is set so that the lower end of each developing device 5 does not contact the exposure device 4 when the image forming frame 54F moves. By setting in this way, the photosensitive drum and the like can be replaced without being damaged. In addition, components such as a charging device constituting an image forming unit provided for each photosensitive drum are opposed to the surface of the photosensitive drum below a horizontal plane including the central axis of the corresponding photosensitive drum. Are arranged as follows. With such an arrangement, the image forming frame 54F including the image forming unit in which the charging device and the like are integrally formed can be lowered vertically downward.

FIG. 8 is an explanatory diagram of a moving mechanism 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 proper position. The lever member 71 is supported so as to be rotatable around the support shaft 65. At the lower end of the lever member 71, a knob 71A for operation by an operator is provided. A cam portion 73 is provided at an upper end of the lever member 71. The stopper 66 regulates the clockwise rotation of the lever member 71. Below the support shaft 65, a pin 63 fixed on a plate cam 60 as a cam member is engaged with a long hole 72 as an engagement portion provided on the lever member 71. 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 main body of the image forming apparatus. An inclined surface 62A is formed on both ends of the plate cam 60, and horizontal surfaces 62B are formed on the left and right sides thereof. The inclined surface 62A and the horizontal surface 62B serve as contact surfaces on which the lower end of a rail R as a rail member supporting the image forming frame 54F, which is a case member of the image forming unit 54, comes in contact. 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 mounted movably in the vertical direction with respect to the image forming apparatus main body. Further, a slide rail R ′ as a movable rail member incorporated in the rail R can slide in a 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 forms an image as a process cartridge in which respective opposed components (image forming elements) having development, charging, cleaning, and charge elimination functions provided to face the photosensitive drums 1A to 1D are formed into a cartridge. The unit 54 is held by a holding unit (not shown).

In the moving mechanism having the above configuration, when the lower side of the lever member 71 is moved in the direction of arrow F by operating the knob 71A of the lever member 71, 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. By the rotation of the lever member 71, the intermediate transfer unit 51 rotates about the center 11A of the support roller 11 as a swing center, and separates from the photosensitive drums 1A, 1B, 1C, 1D. The intermediate transfer unit 51 is pulled out toward the near side of FIG. 8 while one end 51A (the left end in FIG. 8) is along the upper surface of the cam portion 73 and the other end (the right end in the drawing) is along the support roller 11. be able to.
Further, the plate cam 60 moves rightward by the rotation of the lever member 71 in the direction of arrow F, and the rail R descends along the slope 62A of the plate cam 60. An image forming frame 54A holding the image forming units 54 is attached to a slide rail R 'incorporated in the rail R. Therefore, as shown in FIG. 9, each of the image forming units 54 is moved in a state where the opposing components (image forming elements) constituting the image forming unit are separated from the photosensitive drums with the rails R lowered. The entire imaging frame 54F can be extracted. By pulling out the image forming frame 54F in this manner, replacement and maintenance of the image forming unit 54 as a process cartridge in which the opposed components (image forming elements) are integrally formed can be performed.

Note that FIG. 9 shows a case where one image forming unit (process cartridge) 54A, 54B,... Including one of the opposed components (image forming element) is formed for one photosensitive drum. However, the opposing components (image forming elements) for the four photosensitive drums may be combined into one image forming unit 54.
In addition, a black image is formed at the rightmost photosensitive drum 1D, and only the above-mentioned components (image forming elements) facing the photosensitive drum 1D are integrally formed as one independent image forming unit. May be. Then, the above-described opposing components (image forming elements) with respect to the photosensitive drums 1A, 1B, and 1C for forming other color images may be combined into one image forming unit. When the black image forming unit is provided independently as described above, only the frequently used black image forming unit can be replaced, which is economically convenient.

  Further, in the configuration example of FIG. 8 described above, a case is described in which the moving mechanism unit 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 may be configured so as to be separated from the intermediate transfer unit 51 and the image forming unit 54 individually.

In FIG. 8, a projecting portion (operating portion) 60A is formed by projecting the right end of the plate cam 60 toward the swinging unit (moving unit) 50 as shown by a broken line, and the swinging unit (moving unit) is formed. When moving 50, the exposed protrusion 60A may be pulled. When the operator pulls the protruding portion 60A, the plate cam 60 moves to the swing unit (moving unit) 50 side, and the lever member 71 can be rotated counterclockwise.
Further, a pressing behavior is appropriately given by a spring so as to move the plate cam 60 to the right, and the projecting portion 60A is brought into contact with a part of the swinging unit (moving unit) 50. When the 50 is released from the image forming apparatus main body, the plate cam 60 moves in conjunction with the movement of the swing unit (moving unit) 50 to open the transport path, and the lever member 71 can be rotated. .
Further, the cam portion 73 of the lever member 71 may be formed so as to be operable by an operator to rotate the lever member.

  As shown in FIG. 8, when the opposing components (image forming elements) are moved downward to be separated from the photosensitive drum and then taken out, the opposing components and the plate cam 60 of the moving mechanism interfere with each other. In order to avoid this, it is preferable to provide a space S ′ between the image forming frame 54F accommodating the facing components (image forming elements) and the plate cam 60 of the moving mechanism.

  In the printer shown in FIGS. 6 and 7, the moving unit 50 including the transport belt 100 on the right side of the printer body can be moved to the position shown in FIG. 7 by the telescopic guide rail mechanism GR via the support member SPT. It has become. By moving the moving unit 50 in this manner, the transport path of the paper P is almost opened, and the jam handling when the transport failure of the paper P occurs, the cleaning of the separation charge elimination charger CH, the cleaning of the transport guide 29, the registration Maintenance such as cleaning of the roller pair 28 becomes easy. Further, it is easy to take out the transport unit 250U including the transport belt 100. In particular, since one roller 28A of the pair of registration rollers 28 and a part 29A of the transport guide 29 are provided on the transport unit 250U side, the above maintenance can be facilitated. The transport unit 250U can be taken out of the moving unit 50 by gripping the handle HD at the upper part and pulling up in the direction of arrow D. The lower surface of the transport unit 250U is formed in a planar shape, and can be stably placed on a flat surface such as a desk in a posture as it is.

  FIG. 10 is a schematic configuration diagram of a transport unit 250U according to a modified example that can be attached to and detached from the moving unit 50 of the printer in FIGS. The blade cleaner 260 is brought into contact with one roller 28A of the pair of registration rollers 28, and foreign matter such as paper dust scraped from the roller 28A is collected and stored in the collection container 260A. The collection container 260A may be configured integrally with a container for storing dust and waste toner scraped off by the conveyor belt cleaning device 250. In FIG. 10, these containers may be configured to be taken out in a front direction perpendicular to the paper surface, and may be appropriately discarded.

  The primary transfer means and the secondary transfer means in the printer shown in FIGS. 1 and 4 are of a roller type (primary transfer roller 20, secondary transfer roller 120) which comes into contact with the intermediate transfer belt 10 and the transport belt 100, respectively. However, a brush-shaped transfer member, a member formed in a roller shape by a brush, and the like can also be adopted. Further, a non-contact discharge type (charger) can also be employed.

FIG. 11 shows an image forming system in which the printers 301 and 302 shown in FIGS. 1, 4 and 6 are connected to a host computer 300 and the like via a wired network cable 303. In this image forming system, the printers 301 and 302 mainly serve as output devices of the host computer 300. For example, the image read by the scanner 304 connected to the host computer 300 can be appropriately edited and output from the printers 301 and 302.
The printers 301 and 302 and the host computer 300 may be connected by a wireless communication network instead of a cable.

  In the image forming system having the above-described configuration, it is possible to instruct or input the image forming process conditions of the image to be output, the paper discharge mode of the paper P, and the like, according to the guide displayed on the display of the host computer 300. Further, 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. 11 is in a state where the door D is opened and maintenance of the image forming unit can be performed, and a state where the paper supply cassette 26-2 is pulled out to supply and exchange the paper P is illustrated. I have.
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 components pulled out, the photosensitive drums 1A and 1B, the intermediate transfer belt 10, and the like can be attached and detached. The process cartridges 52 and 53 are guided by guide rails (not shown) so that the drawers can be easily and reliably pulled out. Since the door D is supported by the hinges arranged in the vertical direction, even when the door D is opened, the maintenance parts below the door D have good visibility. Although not shown, a seal member is provided to prevent the components of the exposure apparatus 4 from being contaminated by toner or the like.

As described above, according to the present embodiment, the paper 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 leading end of the paper P does not hang down by its own weight. The sheet P can reliably enter the secondary transfer position and the fixing position. Therefore, it is possible to prevent the conveyance failure of the paper P.
Further, the main receiving surface 42 a, which is at least a part of the sheet receiving surface 42 of the discharge stack unit 40, is inclined downward at a constant inclination angle as approaching the discharge port 41 side, and the lowermost end thereof is lower than the discharge port 41. It is a low planar inclined surface. For this reason, as shown in FIG. 12, the sheet P discharged from the discharge port 41 is placed on the sheet receiving surface 42 having a flat inclined surface in a state where its rear end is inclined so as to be lower than the discharge port 41. Can receive. Therefore, a plurality of sheets can be discharged in a state where the rear end of the sheet P received on the sheet receiving surface 42 does not easily collide with the front end of the succeeding sheet P continuously discharged from the discharge port 41. Poor discharge of P can be prevented. In particular, the printer according to the present embodiment is effective when the recording medium is strong (high in rigidity) such as thick paper or an OHP sheet.
The upper stretch 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 tension 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 no dead space is generated therebetween, and the space inside the apparatus can be saved. In addition, since a plurality of photoconductor 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 photoconductor drum are collectively arranged below the intermediate transfer belt 10. And each image forming unit is arranged at a relatively close position. Therefore, unlike the case where the image forming means is provided separately on the upper stretching portion side and the lower stretching portion side of the intermediate transfer belt, some of the components constituting each image forming device (in this embodiment, the exposure device 4) can be shared, and the space inside the device can be further reduced. Therefore, the size of the device can be reduced. When replacing internal components such as the intermediate transfer belt 10 and the photosensitive drum, or units such as the intermediate transfer unit and the process cartridge, the photosensitive drums are separated only from the lower tension portion of the intermediate transfer belt 10. You just have to evacuate. This makes it easier to attach and detach internal components and units than in the case where a plurality of photosensitive drums are respectively arranged so as to face both the upper stretching portion and the lower stretching portion of the intermediate transfer belt. Become. Therefore, maintainability of internal components and units is excellent.

  According to the present embodiment, the image forming means such as the photosensitive drums 1A and 1B, the charging device 3, and the developing devices 5A, 5B, 5C and 5D are separated from the fixing device 30 having the heat source by the intermediate transfer belt. 10 is provided below. Thus, a toner image can be formed on the photosensitive drum without being adversely affected by the heat generated by the fixing device 30. In addition, by inclining the upper stretching portion of the intermediate transfer belt 10 along the paper receiving surface 42, a wedge-shaped space generated below the intermediate transfer belt 10 is effectively used for the layout of the components of the image forming unit. Available. Moreover, in the configuration of the printer according to the present embodiment, the lower tension portion of the intermediate transfer belt 10 is moved from the portion of the plurality of photosensitive drums facing the photosensitive drum far from the secondary transfer position to the secondary transfer position. Move toward the portion facing the photosensitive drum at a position close to. For this reason, the distance from the primary transfer position for each photosensitive drum to the secondary transfer position for transferring to the paper P can be reduced. Accordingly, the time (first print time) from the start of the printing operation to the output of the first sheet P can be shortened.

  In particular, when the image forming unit is configured to form two different color toner images on each of the photosensitive drums 1A and 1B as in the printer shown in FIG. A full-color image can be formed without using one photosensitive drum. Therefore, the size of a printer capable of forming a full-color image can be further reduced.

  Further, according to the present embodiment, the transport unit that transports the paper P is configured to support and transport the paper P along a transport path that faces the intermediate transfer belt 10 at the secondary transfer position and passes through the secondary transfer position. And a transport belt 100 stretched by a plurality of support rollers 111 and 112. Therefore, the transportability of the paper P can be ensured, and the reliability can be increased.

  Further, according to the present embodiment, since the transport belt 100 is formed of a heat-resistant material, even if the transport belt 100 is disposed close to the fixing device 30 having a heat source, the transport belt 100 is deteriorated and deformed. Does not occur. Further, by bringing the transport belt 100 closer to the fixing device 30, the paper P having unfixed toner can be reliably guided to the fixing device 30, and occurrence of an abnormal image can be prevented.

  In addition, according to the present embodiment, the swing unit (moving unit) 50 that can swing around the opening / closing support shaft 50A integrally with the transport belt 100 is swung to the positions shown in FIGS. 2, 4, and 7, respectively. It can be moved (moved). By this swing (movement), the transport path of the paper P can be opened, so that when a transport failure occurs, such as when the paper P stops in the middle of the transport path, the jam clearance is facilitated, and maintenance in the apparatus is facilitated. Will also be easier.

  Further, according to the present embodiment, both sides for transporting the sheet P having passed through the fixing device 30 to the swing unit (moving unit) 50 so that the sheet P passes through the secondary transfer position again with the front and back surfaces reversed. The image forming apparatus includes a conveying unit for forming an image. Therefore, images can be formed on both sides of the sheet P.

  Further, according to the present embodiment, the intermediate transfer belt 10 is separated upward from the plurality of photosensitive drums 1A, 1B, 1C, 1D, and the surface of the photosensitive drum among the constituent elements constituting the image forming means The intermediate transfer belt 10 and the opposing components are configured to be movable so that opposing components (the cleaning device 2, the charging device 3, the developing device 5, and the charge removing device L) opposing to each other are separated downward. . Further, only the photosensitive drums 1A, 1B, 1C, 1D can be attached to and detached from the apparatus main body in a state in which the intermediate transfer belt 10 and the above-described opposed components are separated from the photosensitive drums 1A, 1B, 1C, 1D. Have been. Therefore, the photosensitive drum can be replaced as a single unit, not as a process cartridge, and it is not necessary to replace the intermediate transfer belt and the opposing components which do not need to be replaced while leaving them in the apparatus. The burden on the target can be reduced. In the case of a long-life type in which the surface of the photoconductor drum is reinforced (for example, a type using amorphous silicon), there is almost no chance of replacing the photoconductor drum, so that it is convenient to be able to detach and attach it separately from other replacement parts and units. is there.

Further, according to the present embodiment, there is provided the transport belt unit 250U integrally configured to include the transport belt 100 and a part of the transport path forming member. This transport belt unit 250U is 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 is facilitated.
As shown in FIG. 6, the transport belt unit 250U may include a blade cleaner 260 as cleaning means for cleaning one roller 28A of the pair of registration rollers 28 as a transport member. In this case, the blade cleaner 260 can remove foreign matter such as paper dust adhering to the registration roller 28A, thereby preventing image loss due to foreign matter such as paper dust adhering to the paper P image. can do. Further, it is possible to prevent the foreign matter such as the paper dust from adhering to the fixing roller 30a located on the downstream side in the transport direction and deteriorating its surface.
Further, as shown in FIG. 6, a collection 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 collection container 260A, contamination in the image forming apparatus can be prevented, and the disposal operation can be facilitated.

Further, according to the present embodiment, a plurality of toner cartridges TC containing toner of each color to be supplied to the developing devices (5A, 5B, 5C, 5D) are detachably provided. These toner cartridges TC are arranged between the intermediate transfer belt 10 and the sheet receiving surface 42 of the discharge stack unit 40 along the upper tension portion of the intermediate transfer belt 10 and the main receiving surface (inclined surface) 42a of the discharge unit. Is established. Therefore, the toner cartridge TC can be easily replaced by moving the toner cartridge TC along the upper stretch portion of the intermediate transfer belt 10 and the recording medium receiving surface 42 to the front side of the apparatus which can be operated by the operator.
In addition, since the heat shielding means is provided between the toner cartridge mounting portion TS and the fixing device 30 having a heat source, the replenishment toner in the toner cartridge TC is prevented from being melted and fixed by repeated heating and cooling. it can.

Further, according to the present embodiment, when the heat shielding means is configured using the heat insulating member W, it is advantageous in that the space for the heat shielding means is narrowed and the size of the device is reduced.
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.

  In the present embodiment, the heat shielding unit may be configured using a ventilation unit that allows air to flow between the toner cartridge mounting unit 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, so that the melting and fixing of the toner can be more reliably prevented.

  Further, according to the present embodiment (the printer in FIG. 1), the image forming apparatus includes the intermediate transfer unit 51 including at least the intermediate transfer belt 10 and the support rollers 11 and 12 as the support members. The intermediate transfer unit 51 is configured to be movable in a direction perpendicular to the surface movement direction of the intermediate transfer belt 10 and along the upper stretch portion of the intermediate transfer belt 10 and the paper receiving surface 42 so as to be detachable from the printer main body. Have been. By pulling out the intermediate transfer unit 51, the maintenance and replacement of the intermediate transfer belt 10 and the like are facilitated.

  Further, according to the present embodiment (the 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 separated from the photosensitive drums 1A to 1D. The toner cartridge TC and the intermediate transfer belt 10 do not interfere with each other when moved. Therefore, the maintenance and replacement of the intermediate transfer belt 10 and the like can be reliably performed by pulling out the intermediate transfer unit 51 to the front side.

Further, according to the present embodiment (the printer of FIG. 1), the process cartridge 52 including the photosensitive drums 1A and 1B and at least one of the charging device 3, the developing devices 5A, 5B, 5C and 5D and the cleaning device 2 is provided. Have. The process cartridge 52 is configured to be movable in a direction perpendicular to the surface movement direction of the intermediate transfer belt 10 and along the upper stretch portion of the intermediate transfer belt 10 and the sheet receiving surface 42 so as to be detachable from the printer main body. ing. By pulling the process cartridge 52 forward, maintenance and replacement of the photosensitive drum and the like can be easily performed.
The intermediate transfer unit 51 and the process cartridge 52 may be combined into a single process cartridge 53 as in the printer of FIG.

  According to the present embodiment (the printer in FIG. 7), a process cartridge (image forming apparatus) integrally configured to include at least the charging device 3 and the developing devices 5A, 5B, 5C, and 5D constituting the image forming unit. Unit 54). The process cartridge 54 is configured to be detachable from the main body of the image forming apparatus independently of the photosensitive drum while being separated from the photosensitive drum by the moving mechanism shown in FIG. In this case, maintenance and replacement of the opposing components such as the charging device 3 and the developing devices 5A, 5B, 5C, and 5D that face the photoconductor drum can be easily performed independently of the photoconductor drum.

  The process cartridges (image forming units) 52 and 54 may be provided integrally for all or a part of the plurality of photosensitive drums 1A to 1D. For example, when the process cartridges (image forming units) 52 and 54 are integrally provided for all of the photoconductor drums 1A to 1D, the photoconductor drums 1A to 1D and the photoconductor drums 1A to 1D are opposed to each other by one attachment / detachment operation. Opposing components such as the charging device 3 and the developing devices 5A, 5B, 5C, and 5D can be collectively attached and detached. Also, process cartridges (image forming units) 52 and 54 for one photosensitive drum for forming a black image and process cartridges (image forming unit) 52 for three photosensitive drums for forming a color image. , 54, only the black process cartridge (image forming unit) that is frequently used can be individually replaced.

  Further, according to the present embodiment, the toner cartridge TC as the toner storage unit is perpendicular to the surface movement direction of the intermediate transfer belt 10 and in a direction along the upper tension portion of the intermediate transfer belt 10 and the sheet receiving surface 42. It is configured to be movable and detachable from the printer body. Therefore, the toner can be easily replenished by pulling out the toner cartridge TC with the empty toner toward the front and replacing the toner cartridge TC or replenishing the toner to the toner cartridge TC.

  Further, according to the present embodiment (the printer of FIG. 8), the charging device 3 and the developing devices 5A, 5B, 5C facing the plurality of photosensitive drums 1A to 1D among the constituent elements constituting the image forming means. , 5D, etc., is provided with a moving mechanism for moving the facing components downward. Then, when the opposing component is moved downward and separated from the photoreceptor drums 1A to 1D and then taken out, the opposing component and the moving mechanism are interposed so that the opposing component does not interfere with the moving mechanism. Is provided with a space S2 '. Therefore, the process cartridge (image forming unit) 54 including the above-mentioned opposed components is pulled out to the near side, so that maintenance and replacement of the opposed components such as the charging device 3 and the developing devices 5A, 5B, 5C, 5D can be reliably performed. it can.

  Further, according to the present embodiment (the printer of FIG. 8), the moving mechanism unit is provided with a contact surface with which the lower end of the rail R supporting the opposing component abuts from above. A plate cam 60 as a cam member movable in a direction intersecting with the contact direction of the lower end portion is used. The movement of the plate cam 60 causes the opposing component to move to the image forming position and the separated position separated from the photosensitive drum. The contact surface of the plate cam 60 is formed so as to take the following. By configuring the moving mechanism using such a plate cam 60, the plate cam 60 can be brought into contact with the contact surface of the plate cam 60 by a simple operation of reciprocating the plate cam 60 in the cross direction (horizontal direction). By moving the rail R up and down, the process cartridge (image forming unit) 54 including the opposed components can be moved between the image forming position and the separated position.

  According to the present embodiment (the printer in FIG. 8), the intermediate transfer belt 10 is moved by moving the plate cam 60 to move the opposing component from the image forming position to the separation position. And a supporting member for moving the supporting member from the image forming position to a separating position separated from the photosensitive drum. Specifically, a rotation having a cam portion 73 provided at one end portion and an elongated hole 72 as an engagement 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 using a movable lever member 71. The cam portion 73 of the lever member 71 is formed so as to move the intermediate transfer belt 10 and its supporting member between the image forming position and the separation position as the lever member 71 rotates. In this case, the intermediate transfer belt 10 and the like are moved between the image forming position and the separation position by a simple operation of reciprocating the plate cam 60 in the cross direction (horizontal direction).

Further, according to the present embodiment (the printer in FIG. 8), the process cartridge (image forming unit) 54 including the opposed components described above can be easily operated by rotating the lever member 71 using the knob 71A of the lever member 71. Alternatively, the intermediate transfer belt 10 and the like can be moved between the image forming position and the separation position.
Note that an operation unit operated by an 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 operating section may be a projecting section 60A in which the right end of the plate cam 60 projects toward 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 for opening the transport path. In this case, when the swing unit (moving unit) 50 is moved for maintenance of the apparatus or the like, the movement of the swing unit (moving unit) 50 causes the process cartridge (image forming unit) 54 including the above-described opposing components or the intermediate transfer. 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 is not required.

  According to the present embodiment (the printer in FIG. 8), the movable frame member as the movable rail member movable in the direction of the rotation axis of the photosensitive drum is provided on the image forming frame 54F as the case member to which the above-described facing components are attached. The slide rail R 'is fixed. After the process cartridge (imaging unit) 54 including the opposed 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) is pulled out. ) 54 can be exposed. Therefore, maintenance and replacement of the opposing components such as the charging device 3 and the developing devices 5A, 5B, 5C, and 5D are further facilitated.

  In the above-described embodiment, the case where a plurality of photosensitive drums is provided has been described. However, the present invention can be applied without limitation to the number of photosensitive drums as long as an intermediate transfer body is used. The same effect can be obtained. For example, in the present invention, the formation of toner images of each color (magenta, cyan, yellow, black) on one photosensitive drum and the primary transfer to an intermediate transfer member are sequentially performed using a revolver type developing device or the like. The present invention 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. However, the present invention can be applied to other image forming apparatuses such as a facsimile, a copying machine, and the like, and similar effects can be obtained. .

FIG. 1 is a front view illustrating 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 the swing unit swinged to an open state of the printer. FIG. 6 is a front view illustrating a schematic configuration of a printer according to another embodiment. FIG. 3 is a partial front view showing the swing unit swinged to an open state of the printer. FIG. 9 is a front view illustrating a schematic configuration of a printer according to still another embodiment. FIG. 4 is a front view of the printer when the moving unit is moved to an open state of the printer. FIG. 3 is an explanatory diagram of a moving mechanism unit that moves an intermediate transfer unit and an image forming unit. FIG. 2 is a partial perspective view of the printer in a state where an image forming frame is pulled out. FIG. 6 is a front view of the transport belt unit in a state where the transport belt unit is removed from the swing unit. FIG. 1 is an explanatory diagram of an image forming system using a printer according to an embodiment. FIG. 4 is an explanatory diagram illustrating a state of discharging paper in the printer of the embodiment. FIG. 9 is an explanatory diagram of a paper ejection failure in an image forming apparatus according to a conventional example.

Explanation of reference numerals

Reference Signs List 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 discharge stack section 41 discharge port 42 paper receiving surface 42a inclined surface (main receiving surface)
50 Swinging unit (moving unit)
50A Opening / closing support shaft 51 Intermediate transfer unit 52, 53, 54 Process cartridge (image forming unit)
54F Imaging frame 60 Plate cam 60A Projection 61 Slot 62A Slope 62B Horizontal plane 63, 64 Pin 65 Support shaft 71 Lever member 71A Knob 72 Slot (engagement part)
73 Cam unit 100 Conveying belt 111, 112, 113 Support roller 120 Secondary transfer roller 250U Conveying belt unit F1, F2 Fan G1, G2 Switching guide member P Paper PG1, PG2, PG3, PG4 Refeeding conveyance paths R1, R2 , R3, R4 Conveyance roller R rail R 'slide rail TC toner cartridge W heat insulating member

Claims (34)

A plurality of image carriers, image forming means for forming images of different colors on each image carrier, and a plurality of support members so as to pass through a primary transfer position facing each image carrier; Endless belt-shaped intermediate transfer member driven by a rotating device, a primary transfer means for transferring an image of each color formed on each image carrier onto the intermediate transfer member in a superimposed manner, At a secondary transfer position located on one end side, a secondary transfer unit that collectively transfers the image on the intermediate transfer body to a recording medium, and fixes the image on the recording medium that has passed through the secondary transfer position. Fixing means provided above the secondary transfer position, and the recording medium is conveyed so as to pass upward through the secondary transfer position of the secondary transfer means and the fixing position of the fixing means. Conveying means and a recording medium located above the intermediate transfer body The recording medium that has passed through the only surface and the fixing means there is provided an image forming apparatus that includes a discharge portion having a discharge port for discharging to the recording medium receiving surface,
At least a part of the recording medium receiving surface of the discharge portion is inclined downward as approaching the discharge port side, and the lowermost end thereof is formed with a lower inclined surface than the discharge port,
The intermediate transfer member is stretched such that the intermediate transfer member extends obliquely along the inclined surface of the discharge portion,
An image forming apparatus, wherein the plurality of image carriers are arranged so as to face a lower stretch portion of the intermediate transfer body. The image forming apparatus according to claim 1,
An image forming apparatus, wherein the image forming means is configured to form images of a plurality of different colors on at least one of the image carriers. The image forming apparatus according to claim 1, wherein
The transport unit is configured using a transport belt member stretched by a plurality of support members so as to support and transport the recording medium along a transport path that passes through the secondary transfer position to the fixing position. An image forming apparatus, comprising: The image forming apparatus according to claim 3,
An image forming apparatus, wherein the transport belt member is formed of a heat-resistant material. The image forming apparatus according to claim 3, wherein
An image forming apparatus, comprising: a moving unit capable of integrally moving the transport belt member and a part of a transport path forming member constituting the transport means so as to open the transport path. The image forming apparatus according to claim 5,
The moving unit includes a conveying unit for forming a double-sided image, which conveys the recording medium having passed through the fixing unit so as to pass through the secondary transfer position again in a state where the recording medium is turned upside down. Image forming apparatus. The image forming apparatus according to claim 5, wherein
When the moving unit is moved so as to open the conveying path, a conveying unit integrally configured to include the conveying belt member and a part of the conveying path forming member is moved relative to the moving unit. An image forming apparatus characterized in that it is detachable. The image forming apparatus according to claim 1, wherein
A plurality of toner storage units for storing different toners for forming images of each color to be supplied to the image forming unit are arranged in parallel between the intermediate transfer body and the recording medium receiving surface of the discharge unit,
An image forming apparatus, comprising: a heat shielding unit between the toner storage unit and the fixing unit for blocking heat transmission from the fixing unit to the toner storage unit. The image forming apparatus according to claim 8,
An image forming apparatus comprising: a heat insulating member as the heat shielding means. The image forming apparatus according to claim 8, wherein
An image forming apparatus, comprising: a ventilation unit that circulates air between the toner storage unit and the fixing unit as the heat shielding unit. The image forming apparatus according to claim 1, wherein
A plurality of toner storage units for storing different toners for forming images of each color to be supplied to the image forming unit are arranged in parallel between the intermediate transfer body and the recording medium receiving surface of the discharge unit,
An image forming apparatus, wherein the toner container is formed of a heat insulating material. The image forming apparatus according to claim 1, wherein
A plurality of toner storage units for storing different toners for forming images of each color to be supplied to the image forming unit are arranged in parallel between the intermediate transfer body and the recording medium receiving surface of the discharge unit,
A space is provided between the toner storage section and the intermediate transfer body so that the toner storage section does not interfere with the intermediate transfer body when the intermediate transfer body is moved to separate from the plurality of image carriers. An image forming apparatus comprising: The image forming apparatus according to any one of claims 8 to 12,
An image forming apparatus, wherein the toner container is detachable from an image forming apparatus main body. The image forming apparatus according to any one of claims 1 to 13,
An image forming apparatus, wherein an intermediate transfer unit integrally formed so as to include the intermediate transfer body and a supporting member thereof is detachable from an image forming apparatus main body while being separated from the image carrier. . The image forming apparatus according to any one of claims 1 to 14,
A process cartridge integrally configured to include the image carrier and at least one of a charging device, a developing device, and a cleaning device that cleans a surface of the image carrier, which constitutes the image forming unit, forms an image. An image forming apparatus, which is detachable from an apparatus main body. The image forming apparatus according to any one of claims 1 to 14,
A process cartridge integrated so as to include at least a charging device and a developing device constituting the image forming means is separated from the image carrier independently of the image carrier with respect to the image forming apparatus main body. An image forming apparatus which is detachable. The image forming apparatus according to any one of claims 1 to 16,
The intermediate transfer member is separated from the plurality of image carriers so that the intermediate transfer member and an opposing component of the components constituting the image forming unit that oppose the image carrier are separated from each other. And the opposing component is configured to be movable,
An image forming apparatus, wherein only the image carrier is detachably attached to the apparatus main body in a state where the intermediate transfer member and the facing component are separated from the image carrier. The image forming apparatus according to any one of claims 1 to 13,
An image forming apparatus, wherein a process cartridge integrally formed so as to include the image carrier, the intermediate transfer body, and a supporting member thereof is detachable from an image forming apparatus main body. The image forming apparatus according to claim 15, 16, or 18,
An image forming apparatus, wherein the process cartridge is provided integrally for all or a part of the plurality of image carriers. The image forming apparatus according to claim 1, wherein
A moving mechanism for moving a facing component facing the plurality of image carriers downward among components constituting the image forming unit,
When the opposing component is moved downward so as to be separated from the plurality of image carriers and then taken out, the opposing component and the moving mechanism unit do not interfere with each other so that the opposing component does not interfere with the moving mechanism unit. An image forming apparatus, wherein a space is provided between the image forming apparatuses. The image forming apparatus according to claim 20,
A cam that has a contact surface with which the lower end of the rail member supporting the opposing component abuts from above, and that can move the moving mechanism in a direction intersecting the contact direction of the lower end of the rail member; Composed using members,
The image forming apparatus according to claim 1, wherein the contact surface of the cam member is formed so that the opposing component can take an image forming position and a separated position separated from the image carrier by moving the cam member. apparatus. The image forming apparatus according to claim 21,
The intermediate transfer body and its supporting member are separated from the image carrier from the image forming position by the movement of the cam member that moves the opposing component from the image forming position to the separation position. An image forming apparatus configured to be moved to a separated position. The image forming apparatus according to claim 22,
The moving mechanism section includes a cam portion provided at one end, and a rotatable lever member having an engaging portion that engages with the cam member so as to rotate in conjunction with the cam member.
The cam portion of the lever member is formed so as to move the intermediate transfer body and its support member between the image forming position and the separation position as the lever member rotates. Image forming apparatus. The image forming apparatus according to claim 23,
An image forming apparatus, wherein the lever member is provided with a knob operated by an operator to rotate the lever member. The image forming apparatus according to claim 23,
An image forming apparatus, wherein the cam portion of the lever member is operable by an operator to rotate the lever member. The image forming apparatus according to claim 23,
The transport unit is configured using a transport belt member stretched by a plurality of support members so as to support and transport the recording medium along a transport path that passes through the secondary transfer position to the fixing position. And
A moving unit capable of integrally moving the conveying belt member and a part of a conveying path forming member constituting the conveying means, so as to open the conveying path;
An image forming apparatus, wherein the lever member is configured to rotate in conjunction with movement of the moving unit to open the transport path. The image forming apparatus according to any one of claims 20 to 26,
An image forming apparatus, comprising: a case member to which the facing component is attached; and a movable rail member fixed to the case member and movable in a direction of a rotation axis of the image carrier. A transport unit in the image forming apparatus according to claim 7, wherein
It is configured to include the transport belt member and a part of the other transport member,
A transport unit that is detachable from the moving unit that has been moved to open the transport path. 29. The transport unit according to claim 28,
With one of the registration roller pair as a part of the transport member,
A transport unit comprising cleaning means for cleaning said roller. 29. The transport unit according to claim 28,
A transport unit comprising a storage section for storing foreign matter removed by the cleaning means. An intermediate transfer unit in the image forming apparatus according to claim 14,
Integrally configured to include the intermediate transfer member and its support member,
An intermediate transfer unit which is detachable from the image forming apparatus main body while being separated from the image carrier. A process cartridge in the image forming apparatus according to claim 15, wherein:
The image carrier, integrally configured to include at least one of a charging device constituting the image forming unit, a developing device and a cleaning device for cleaning the surface of the image carrier,
A process cartridge detachable from an image forming apparatus main body. A process cartridge in the image forming apparatus according to claim 16, wherein:
It is integrally configured to include at least a charging device and a developing device constituting the image forming unit,
A process cartridge which is detachable from an image forming apparatus main body independently of the image carrier while being separated from the image carrier. A process cartridge in the image forming apparatus according to claim 18, wherein:
It is integrally configured to include the image carrier, the intermediate transfer body and a support member thereof,
A process cartridge detachable from an image forming apparatus main body.

Images