JP2001356548A - Color image forming equipment - Google Patents

Abstract

(57) [Problem] To provide a color image forming apparatus which can reduce the installation area and does not cause color misregistration. SOLUTION: An intermediate transfer member 5 is arranged upright in a vertical direction, and photosensitive drums 3M, 3M are arranged along a moving surface thereof.
C, 3Y, 3Bk and developing units 51M, 51C, 51Y, 5
A process cartridge consisting of 1Bk is provided. An openable and closable side cover 2 is provided on the side of the side opposite to the surface of the intermediate transfer body 5, and the process cartridge is detachably provided from the side of the side cover 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color image for forming a color image by arranging a plurality of electrostatic latent image carriers developed by developers of respective colors along a moving direction of an intermediate transfer body. Belongs to the technical field of forming equipment.

[0002]

2. Description of the Related Art Conventionally, as a color image forming apparatus, cyan, magenta, yellow and black toners are used.
A so-called tandem-type color image forming apparatus in which different developing units are accommodated, and these developing units and electrostatic latent image carriers developed by these developing units are arranged in a vertical or horizontal direction. is there.

In this tandem-type color image forming apparatus, since each developing device containing the toner of each color can perform the developing operation substantially simultaneously, a color image can be formed at an extremely high speed.

[0004]

However, in a conventional tandem type color image forming apparatus, a plurality of process units each including a photosensitive drum and a developing device are juxtaposed substantially in parallel with the installation surface of the color image forming apparatus. In this case, there is a problem that the installation area becomes large.

[0005] Therefore, an apparatus in which the installation area is reduced by arranging the plurality of process units in a vertical direction is disclosed in, for example, JP-A-08-190245.

However, in the method disclosed in the above-mentioned publications, the discharge tray protrudes from the side of the apparatus, or the configuration of each developing unit is complicated and large, so that the entire color image forming apparatus is small. It was difficult to convert.

Further, in the conventional apparatus, the side plate in the direction perpendicular to the axial direction of the photosensitive drum is made freely openable and closable, and the process unit is replaced by opening the side plate.

Inside the apparatus viewed from the side plate, there are means for positioning the rotation axis of the photosensitive drum or means for positioning the rotation axis of the driving roller of the intermediate transfer belt. Therefore, there is a problem that it is difficult to replace the process unit.

As a result, a new process unit may not be mounted at an appropriate position, and there is a problem that an image of a certain color is shifted from an image of another color, that is, a so-called color shift occurs.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a color image forming apparatus which can solve the above-mentioned problems, can reduce the installation area, and does not cause color misregistration.

[0011]

According to a first aspect of the present invention, there is provided a color image forming apparatus, comprising: a belt-like intermediate transfer member provided so that a surface thereof moves in a substantially vertical direction; A plurality of electrostatic latent image carriers arranged in a substantially vertical direction along the moving direction of the surface, a plurality of charging means for charging a surface of each of the plurality of electrostatic latent image carriers, A plurality of exposure means for exposing a charged region on each surface of the plurality of electrostatic latent image carriers, and a plurality of developer carriers arranged so as to face each of the plurality of electrostatic latent image carriers; And a plurality of developing means including a developing unit, and at least the developing means is detachably provided to the apparatus main body as a process cartridge from a side surface of the belt-shaped intermediate transfer body facing the surface. It is characterized by.

According to the color image forming apparatus of the first aspect, each of the plurality of electrostatic latent image carriers is arranged in a substantially vertical direction along the moving direction of the surface of the belt-shaped intermediate transfer body. The plurality of charging units, the plurality of exposing units, and the plurality of developing units are provided so as to face the respective electrostatic latent image carriers. Therefore, it is not necessary to secure the arrangement areas of the intermediate transfer member, the electrostatic latent image carrier, the charging unit, the exposure unit, and the developing unit in the direction parallel to the installation surface of the color image forming apparatus main body. Since it is sufficient to secure the mounting surface in a direction perpendicular to the mounting surface, the area of the mounting surface can be reduced.

Further, since the replacement of the process cartridge is carried out from the side surface of the belt-shaped intermediate transfer member facing the surface, the holding members provided at both ends in the axial direction of the intermediate transfer member, or Positioning means and the like provided at both ends in the axial direction of the electrostatic latent image carrier do not hinder the exchange. As a result, the process cartridge is reliably mounted at an appropriate position, and the occurrence of so-called color misregistration is reliably reduced.

According to a second aspect of the present invention, there is provided a color image forming apparatus according to the first aspect, wherein an LED array is fixed to the apparatus main body as the plurality of exposure means. It is characterized by having.

According to the color image forming apparatus of the present invention, the L is provided extending in the axial direction of the electrostatic latent image carrier.
In order to provide the ED array fixedly to the color image forming apparatus, it is necessary to support the LED array at both ends in the axial direction. Since the transfer is performed from the side of the intermediate transfer member facing the surface, the LED
The support of the array does not hinder the exchange. As a result, displacement of the LED array is reliably prevented, and occurrence of so-called color misregistration is reliably reduced.

According to a third aspect of the present invention, there is provided a color image forming apparatus according to the second aspect, wherein the process cartridge includes at least the developing means and the electrostatic latent image carrier. Wherein each of the plurality of LED arrays includes an axis of the electrostatic latent image carrier when the process cartridge is mounted, and the electrostatic latent image is based on a plane perpendicular to the surface of the intermediate transfer body. It is characterized in that the plurality of electrostatic latent image carriers are arranged so as to face respective surfaces of the plurality of electrostatic latent image carriers from a direction opposite to a direction in which the carrier is separated from the intermediate transfer body.

According to a third aspect of the present invention, in the color image forming apparatus, the process cartridge includes at least the developing unit and the electrostatic latent image carrier. With reference to a plane including the axis of the electrostatic latent image carrier when the cartridge is mounted and perpendicular to the surface of the intermediate transfer body, from the direction opposite to the direction in which the electrostatic latent image carrier is separated from the intermediate transfer body. Since it is opposed to each surface of the plurality of electrostatic latent image carriers, even when using an LED array that needs to be arranged close to the electrostatic latent image carrier,
The LED array does not interfere when the process cartridge is detached. As a result, the process cartridge is securely mounted at an appropriate position, and the displacement of the LED array is reliably prevented, so that the occurrence of so-called color misregistration is reliably reduced.

According to a fourth aspect of the present invention, there is provided a color image forming apparatus according to any one of the first to third aspects, wherein each of the plurality of electrostatic latent image carriers is provided. After transferring the developer image formed on the intermediate transfer member, the developer remaining on each electrostatic latent image carrier is charged and exposed with the movement of each electrostatic latent image carrier, and the plurality of developer It is characterized by being recovered by each of the agent carriers.

According to the color image forming apparatus of the present invention, the transfer residual developer on each electrostatic latent image carrier is charged and exposed together with the movement of each electrostatic latent image carrier, and the plurality of developing agents are transferred. Since the developer is collected by each of the developer carriers, a waste developer container for storing the transfer residual developer is not required. Therefore, when replacing the process cartridge, the waste developer container is not hindered, and so-called color misregistration is reliably reduced.

According to a fifth aspect of the present invention, there is provided a color image forming apparatus according to any one of the first to fourth aspects, wherein the process cartridge comprises at least the developing means and the developing means. An electrostatic latent image carrier, wherein the plurality of charging units are provided on the apparatus main body side, and are separated from the electrostatic latent image carrier when the process cartridge is replaced.

According to the color image forming apparatus of the present invention, the charging means is separated from the electrostatic latent image carrier when the process cartridge is replaced. The replacement of the process cartridge including the cartridge can be easily performed without being hindered by the charging unit. Therefore, the occurrence of a so-called color shift at the time of replacing the process cartridge is reliably prevented.

According to a sixth aspect of the present invention, there is provided a color image forming apparatus as set forth in any one of the first to fifth aspects, further comprising: a transfer medium supply tray for supplying a transfer medium; A transfer medium discharge tray on which a transfer medium to be discharged after the image forming process is completed is further provided. The direction in which the transfer medium supply tray and the process cartridge are attached and detached, and the direction in which the transfer medium is discharged to the transfer medium discharge tray are The surface of the belt-like intermediate transfer member provided so that the surface moves along a substantially vertical direction is a direction facing the surface.

According to the color image forming apparatus of the present invention, the direction of attaching and detaching the transfer medium supply tray and the direction of discharging the transfer medium to the transfer medium discharge tray are the same as the direction of attaching and detaching the process cartridge. Since the surface is opposed to the surface of the belt-shaped intermediate transfer member provided so that the surface moves substantially in the vertical direction, it does not hinder miniaturization of the apparatus, and also allows the user to attach and detach the transfer medium supply tray. Also, the workability of taking out the discharged transfer medium is improved.

According to a seventh aspect of the present invention, there is provided a color image forming apparatus according to the sixth aspect, further comprising an operation panel including various operation buttons and the like. The belt is mounted in such a manner that its operation direction is the direction facing the surface of a belt-shaped intermediate transfer member provided so that its surface moves substantially vertically.

According to the color image forming apparatus of the present invention, the operation direction of the operation panel is the same as the direction of attachment / detachment of the process cartridge and the transfer medium supply tray and the direction of discharge of the transfer medium to the transfer medium discharge tray. Because of the direction, the operability is further improved without hindering downsizing of the device. Further, by arranging a plurality of electrostatic latent image carriers in a substantially vertical direction, the height of the image forming apparatus main body is increased, and it is difficult to operate the image forming apparatus if an operation panel is provided on the upper surface. , Such a problem does not occur.

According to a eighth aspect of the present invention, there is provided a color image forming apparatus according to any one of the first to seventh aspects, wherein the plurality of electrostatic latent image carriers are provided. A cleaning unit for recovering the transfer residual developer is provided outside the process cartridge, and the cleaning unit includes a transport unit that transports the collected waste developer in a moving axis direction of the electrostatic latent image carrier. It is characterized by being provided.

According to the color image forming apparatus of the present invention, since the cleaning means is not included in the process cartridge, the cleaning means does not interfere when the process cartridge is replaced. Therefore,
It is possible to reliably prevent a so-called color shift from occurring when the process cartridge is replaced. Further, since the collected waste developer is transported by the transport unit in the moving axis direction of the electrostatic latent image carrier, after the transport, the developer can be dropped downward by gravity. Even when the developer is not included in the process cartridge, the waste developer can be properly processed.

[0028]

Embodiments of the present invention will be described below with reference to the accompanying drawings. (First embodiment)

First, a first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a schematic sectional side view of a color laser printer as a color image forming apparatus to which the present invention is applied.

The color image forming apparatus 1 illustrated in FIG.
The image forming apparatus includes a visible image forming unit 4, a belt-shaped intermediate transfer body 5, a fixing unit 8, a paper feed unit 9, and a paper discharge tray 10.

The visible image forming section 4 includes a developing unit 51 for each visible image process using magenta (M), cyan (C), yellow (Y), and black (Bk) toners.
M, 51C, 51Y, and 51Bk, and the photosensitive drums 3M and 3M.
C, 3Y, 3Bk, cleaning rollers 70M, 70
C, 70Y, 70Bk, chargers 71M, 51C, 51
Y, 51Bk, and LED arrays 72M, 72C, 72
Y, 72Bk. Hereinafter, each of these components will be described in detail.

First, the developing units 51M, 51C, 51Y, 5
1Bk includes a developing roller 52M as a developer carrier,
52C, 52Y, and 52Bk are provided. Each of the developing rollers 52M, 52C, 52Y, and 52Bk is formed in a cylindrical shape using conductive silicone rubber as a base material, and further has a coat layer of a resin or rubber material containing fluorine on the surface. The developing rollers 52M, 52C, 52Y,
In 52Bk, the base material does not necessarily need to be formed of conductive silicone rubber, and may be formed of conductive urethane rubber. The ten-point average roughness (Rz) of the surface is 3 to 5 μm.
m, which is smaller than the average particle diameter of the toner of 9 μm. The developing roller 5
A predetermined voltage is applied to 2M, 52C, 52Y, and 52Bk, and is configured to have a predetermined potential difference between the photosensitive drums 3M, 3C, 3Y, and 3Bk.

Each developing unit 51M, 51C, 51Y, 51B
k also includes supply rollers 53M, 53C, 53Y, 5
3Bk is provided. Supply rollers 53M, 53C,
53Y and 53Bk are conductive sponge rollers,
The developing rollers 52M, 52C, 52Y, and 52Bk are arranged so as to press and contact with the sponge elastic force. The supply rollers 53M, 53C, 53Y, 5
As 3Bk, other suitable members such as conductive silicone rubber or urethane rubber can be used.

Each developing device further includes a layer thickness regulating blade 5.
4M, 54C, 54Y, and 54Bk are provided. Layer thickness regulating blades 54M, 54C, 54Y, 54
Bk is formed of stainless steel or the like, and supports 54aM, 54aC, 54aY, 54aBk whose base ends are fixed to the developing device cases 55M, 55C, 55Y, 55Bk, and tips of the supports 54aM, 54aC, 54aY, 54aBk. And a contact portion 54bM, 5 made of conductive silicone rubber or conductive fluorine-containing rubber or resin.
4bC, 54bY, and 54bBk. The contact portions 54bM, 54bC, 54bY, and 54bBk are the support portions 5
The developing rollers 52M, 52C, 52Y, and 52Bk are pressed against each other by the elastic force of 4aM, 54aC, 54aY, and 54aBk. Contact portions 54bM, 54bC, 54bY, 54b
As shown in FIG. 1, the shape of Bk is formed such that the cross section is a substantially half-moon-shaped convex shape. In the present embodiment, the thickness regulating blades 54M, 54C, 54Y, 5
4Bk, the developing rollers 52M, 52C, 52Y,
A predetermined voltage is applied in conjunction with 52Bk.

Further, the developing device cases 55M, 55C, 55
The toner stored in Y, 55Bk is a positively charged non-magnetic one-component developer, and a well-known colorant such as carbon black is added to a styrene-acrylic resin formed into a spherical shape by suspension polymerization, and It has toner base particles having an average particle diameter of 9 μm to which a charge control agent such as nigrosine, triphenylmethane, or quaternary ammonium salt or a charge control resin is added. The toner T is configured by adding silica as an external additive to the surface of the toner base particles. The silica as the external additive is subjected to a well-known hydrophobic treatment using a silane coupling agent, silicone oil, or the like, has an average particle size of 10 nm, and is added in an amount of 0.6% by weight of the toner base particles. It is. Each developing device case 55M, 55
C, 55Y, and 55Bk contain magenta, cyan, yellow, and black toners, respectively.

As described above, the toner is a suspension polymerization toner having an almost spherical shape, and 0.6% by weight of hydrophobically treated silica having an average particle diameter of 10 nm is added as an external additive. Extremely fluid. for that reason,
A sufficient charge amount can be obtained by frictional charging. Further, since there is no corner portion unlike pulverized toner, it is hard to receive a mechanical force, has excellent followability to an electric field, and has good transfer efficiency.

A photosensitive drum 3M as an electrostatic latent image carrier,
As 3C, 3Y, and 3Bk, for example, a material in which a positively chargeable photosensitive layer is formed on an aluminum base material is used. The thickness of the photosensitive layer is formed to be 18 μm or more,
The aluminum base is used as an earth layer. Further, the photosensitive drums 3M, 3C, 3Y, 3
Bk is driven to rotate in the direction of the arrow shown in FIG.

The cleaning rollers 70M, 70C, 70Y and 70Bk as cleaning means are rollers made of a conductive elastic material such as sponge.
M, 3C, 3Y, and 3Bk are configured to be rubbed. The cleaning rollers 70M, 70C, 70Y,
A voltage (not shown) is applied to the 70Bk by a power supply (not shown). The voltage is applied to the photosensitive drums 3M, 3C, 3Y, and 3Bk by the sliding force and the action of the electric field by the voltage. , And residual toner is removed from the photosensitive drums 3M, 3C, 3Y, and 3Bk. In the present embodiment, since a so-called cleanerless developing method is employed, the cleaning roller 70 is temporarily stopped in a predetermined cycle after the developing process is completed.
The residual toner removed by M, 70C, 70Y, and 70Bk can be returned to the photosensitive drums 3M, 3C, 3Y, and 3Bk again.

Chargers 71M, 71C as charging means
71Y and 71Bk are scorotron type chargers,
The cleaning rollers 70M, 70C, 70Y, 70
Bk, the photosensitive drums 3M, 3C, 3Y, 3Bk
Downstream of the rotation direction of the photosensitive drums 3M, 3M,
C, 3Y, and 3Bk are disposed so as to face each other. In addition, as the chargers 71M, 71C, 71Y, and 71Bk,
A roller type charger that contacts the photosensitive drums 3M, 3C, 3Y, and 3Bk may be used.

LED arrays 72M and 7 as exposure means
2C, 72Y, and 72Bk are the chargers 71M, 71B.
C, 71Y and 71Bk, the photosensitive drums 3M and 3M
The photosensitive drums 3M, 3C, 3Y, and 3Bk are disposed on the downstream side in the rotation direction of C, 3Y, and 3Bk so as to face the surfaces of the photosensitive drums 3M, 3C, 3Y, and 3Bk. Exposure means 72M, 72C, 72Y, 72B
k, light corresponding to the drawing data is applied to the photosensitive drums 3M and 3M.
C, 3Y and 3Bk are irradiated onto the surface of the photosensitive drum 3
On the surfaces of M, 3C, 3Y, and 3Bk, an electrostatic latent image for each color is formed.

With the above configuration, the developing roller 52
M, 52C, 52Y, 52Bk and photosensitive drums 3M, 3M
C, 3Y, and 3Bk, the photosensitive drum 3
For a positive polarity (positively charged) electrostatic latent image formed on M, 3C, 3Y, and 3Bk, a positively charged toner can be favorably developed by a reversal developing method, and an extremely high-quality image can be formed. Can be formed.

In this embodiment, the photosensitive drums 3M, 3C, 3Y, and 3Bk, and the developing devices 51M, 51C,
51Y and 51Bk are formed as process cartridges, and are provided detachably with respect to the apparatus main body, as shown in FIG. On the other hand, the cleaning roller 70
M, 70C, 70Y, 70Bk, chargers 71M, 71
C, 71Y, 71Bk, and LED arrays 72M, 72
C, 72Y, and 72Bk are provided fixedly to the apparatus main body.

The belt-shaped intermediate transfer member 5 is formed by forming a conductive sheet such as polycarbonate or polyimide into a belt shape. As shown in FIG. 1, the belt-like intermediate transfer member 5 is stretched over two drive rollers 60 and 62, and the intermediate transfer roller 5 is located near the photosensitive drums 3M, 3C, 3Y and 3Bk. 61M, 61C, 6
1Y and 61Bk are provided. The moving direction of the surface of the intermediate transfer body 5 on the side facing the photosensitive drums 3M, 3C, 3Y, and 3Bk is set to a direction in which the intermediate transfer body 5 moves upward from below in the vertical direction, as shown in FIG.

The intermediate transfer rollers 61M, 61C, 61Y,
A predetermined voltage is applied to 61Bk, so that the toner images formed on the photosensitive drums 3M, 3C, 3Y, and 3Bk are transferred to the belt-shaped intermediate transfer member 5 made of the conductive sheet. Have been. The roller 62 at the position where the toner image is transferred to the sheet is provided with a roller 63.
Are provided to face each other, and a predetermined potential is also applied to the roller 63. As a result, the belt-like intermediate transfer member 5
The four color toner images carried on the top are transferred to the paper.

It should be noted that the photosensitive drums 3M, 3M
On the side opposite to the side facing C, 3Y and 3Bk, a cleaning device 6 is provided as shown in FIG. The cleaning device 6 includes a scraping member 65 made of a conductive brush.
And a case 66. The toner remaining on the intermediate transfer body 5 is electrically scraped by a scraping member 65 and stored in the case 66.

The fixing unit 8 includes a heating roller 82 and a pressure roller 81. The fixing unit 8 heats and heats the sheet carrying the toner images of four colors while holding the sheet by the heating roller 82 and the pressure roller 81. By pressing, the toner image is fixed on the paper.

The paper feeding unit 9 includes a storage tray 91 for storing the paper P, and a pickup roller 92 for feeding the paper.
It is composed of The paper feed unit 9 takes a predetermined time from the image forming process by the LED arrays 72M, 72C, 72Y, and 72Bk, the visible image unit 4, the photosensitive drums 3M, 3C, 3Y, and 3Bk, and the intermediate transfer body 5, and takes a predetermined timing. Is provided. The paper P supplied from the paper feeding unit 9 is transported by the transport roller pair 100 to a pressure contact portion between the intermediate transfer body 5 and the roller 63.

The paper discharge tray 10 is provided on the paper discharge side of the fixing unit 8, and is configured to store the paper P discharged from the fixing unit 8 and conveyed by the conveying roller pairs 101 and 102. ing.

Next, the operation of the color image forming apparatus according to the present embodiment as described above will be described. First, the photosensitive layers of the photosensitive drums 3M, 3C, 3Y, and 3Bk are
M, 71C, 71Y, 71Bk uniformly charged,
Next, these photosensitive layers are applied to the LED arrays 72M, 72M.
Exposure is performed using LED light corresponding to magenta, cyan, yellow, and black images irradiated by C, 72Y, and 72Bk. And the magenta developing device 5
1M, a cyan developing device 51C, a yellow developing device 51Y, and a black developing device 51Bk.
The electrostatic latent images formed on the C, 3Y, and 3Bk photosensitive layers
A magenta toner, a cyan toner, a yellow toner, and a black toner are adhered, and magenta, cyan, yellow, and black are developed. The magenta, cyan, yellow, and black toner images formed as described above are temporarily
Is transferred onto the surface of

Next, the photosensitive drums 3M, 3C, 3
Y, the toner remaining on 3Bk is the cleaning roller 7
OM, 70C, 70Y, 70Bk.

The toner images of the respective colors are formed with a slight time difference according to the moving speed of the intermediate transfer member 5 and the positions of the photosensitive drums 3M, 3C, 3Y, 3Bk. Are transferred so as to be superimposed on the intermediate transfer member 5.

The four-color toner images formed on the intermediate transfer member 5 as described above are transferred onto the sheet P supplied from the paper supply unit 9 at the position where the roller 63 and the intermediate transfer member 5 are pressed against each other. Is done. Then, the toner image is fixed on the paper P in the fixing unit 8 and is discharged onto the paper discharge tray 10. As described above, a four-color image is formed.

As described above, in the color image forming apparatus of this embodiment, the visible image forming section 4 for each color
Since the so-called tandem method is employed, which is disposed along the moving direction, a color image can be formed at the same high speed as in the case of forming a single color image.

In the present embodiment, since the intermediate transfer member 5 is a belt-shaped member, the surface facing the visible image forming portion can be made long, and as described above, all the visible The image forming units can be arranged side by side in the vertical direction. As a result, the installation area of the apparatus main body can be reduced as compared with the conventional horizontal type.

In this embodiment, as shown in FIG. 1, the side cover 2 is configured to be rotatable about the shaft 20 in the direction of the arrow in FIG. FIG. 2 shows a state where the side cover 2 is opened. With such a configuration, the developing devices 51M, 51C, 51Y, and 51Bk can be easily replaced. Although the axis 2c is parallel to the horizontal direction, the axis 2c may be parallel to the vertical direction and the side cover may be opened around the axis.

In the laser beam printer 1 of this embodiment, as shown in FIG. 3, frames 11A and 11B are provided at both ends of the intermediate transfer member 5 in the rotation axis direction. The frames 11 </ b> A and 11 </ b> B
Positioning members for rotating shafts at 0 and 62, and positioning members for rotating shafts for photosensitive drums 3M, 3C, 3Y, and 3Bk;
And LED arrays 72M, 72C, 72Y, 72Bk
Is used as a support member. FIG. 3 shows the frames 11A and 11B when the developing units 51M, 51C, 51Y, and 51Bk are removed from the side surface side on which the side cover 2 is provided, and the photosensitive drum 3M, 3C, 3Y, 3Bk and LED array 72M, 7
It is a figure which shows the positional relationship with 2C, 72Y, 72Bk.

As shown in FIG. 2, the frames 11A and 11B are formed with a positioning hole 12 for the rotating shaft 30M of the photosensitive drum 3M and a guide groove 13 for guiding the rotating shaft 30M to the positioning hole 12. This configuration is similar to the rotation axes 30C, 30Y of the other photosensitive drums 3C, 3Y, 3Bk.
The same applies to 30Bk. As shown in FIG. 3, each of the rotating shafts 30M, 30C, 30Y, and 30Bk
Positioning is performed by 1A and 11B.

Accordingly, in this embodiment, the process cartridge can be replaced by opening the side cover 2 provided on the side surface facing the surface of the intermediate transfer member 5 as shown in FIG. Frame 11A,
11B does not hinder the replacement operation. That is, since the process cartridge can be easily replaced, the process cartridge can be reliably mounted at an appropriate disposition position so that the rotating shaft 30M is mounted on the positioning hole 12. As a result, since there is no positional displacement of each process cartridge, it is possible to reliably prevent so-called color misregistration in which only a specific color image is misaligned with respect to other color images.

In this embodiment, the LED arrays 72M, 72C, 72Y and 72Bk are mounted on the frames 11A and 11B as shown in FIG. 3, and are fixedly provided to the apparatus main body. And guide groove 1
3 extends below the positioning hole 12, and the LED array 72 is provided above the positioning hole 12. That is, when the photosensitive drums 3M, 3C, 3Y, and 3Bk are separated from the intermediate transfer member 5, the photosensitive drums 3M, 3C, 3Y, and 3Bk move downward (in the separating direction of claim 3).
Go to Therefore, as described above, the process cartridge is provided with these LED arrays 72M, 72C, 72Y,
It is removable without interfering with the frames 11A and 11B supporting 72Bk. Therefore, even if the process cartridge replacement operation is performed, the LED arrays 72M, 72M
The positions of C, 72Y, and 72Bk do not shift, and the color shift can be reliably prevented from this point.

In the present embodiment, a so-called cleanerless developing method is employed. Therefore, in a predetermined cycle after the completion of the developing step, the cleaning roller 70 is temporarily stopped.
The residual toner removed by M, 70C, 70Y, and 70Bk can be returned to the photosensitive drums 3M, 3C, 3Y, and 3Bk again. Therefore, in this embodiment, there is no need to provide a waste toner box. In conventional devices that do not use the cleanerless development method, it is necessary to provide a waste toner box around the photosensitive drum, and the replacement work is difficult due to interference between the photosensitive drum and the waste toner box when replacing the process cartridge. There was a problem of becoming. However, in the present embodiment, since there is no need to provide a waste toner box, there is no such a problem.
The process cartridge can be easily replaced. From this point as well, the occurrence of color shift can be reliably prevented.

Further, in the present embodiment, the charger 71
When the process cartridge is replaced, M, 71C, 71Y, and 71Bk, as shown in FIG.
It is configured to be separated from C, 3Y, and 3Bk.
Therefore, the replacement of the process cartridge is not hindered by the chargers 71M, 71C, 71Y, and 71Bk, and the color shift can be reliably prevented from this point.

In the present embodiment, as shown in FIG. 2, the direction in which the paper P is discharged from the paper discharge tray 10 and the direction in which the process cartridge is attached and detached are the same. Further, the sheet feeding tray 9 is configured to be attached and detached in the same direction. Therefore, it is possible to reduce the size of the apparatus and to provide a laser beam printer with good operability. Further, as shown in FIG. 4, an operation panel 15 is provided at the upper right of the side surface. Therefore, the opening / closing direction of the side cover 2, the direction of taking out the discharged paper, and the operation direction of the operation panel 15 when replacing the process cartridge are all in the same direction. Can be. Further, a plurality of photosensitive drums 3M, 3C,
By arranging the 3Y and 3Bk in a substantially vertical direction, the height of the image forming apparatus main body increases, but the operability is good because the operation panel 15 is provided on the side surface.

(Second Embodiment) Next, a second embodiment of the present invention will be described with reference to FIGS. In addition,
The same parts as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

In this embodiment, as shown in FIG. 5, the moving direction of the surface of the intermediate transfer member 5 facing the photosensitive drums 3M, 3C, 3Y, and 3Bk is from the vertical upper direction to the lower direction. Different from the first embodiment.

When the intermediate transfer member 5 is configured as described above, as shown in FIG. 5, the positions of the sheet feeding unit 9 and the transfer roller 63 are located lower than the intermediate transfer member 5. Become.

Further, each of the photosensitive drums 3M, 3C, 3Y, 3
Since the rotation direction of Bk is counterclockwise as shown in FIG. 2, the cleaning means 73M, 7
3C, 73Y, 73Bk, and chargers 71M, 71C,
71Y, 71Bk, and LED arrays 72M, 72
The positions of C, 72Y, and 72Bk are also the photosensitive drums 3M, 3C,
It is set lower for 3Y and 3Bk.

Further, the thickness regulating blades 54M, 54C,
The positions of 54Y and 54Bk are also the same as those of developing rollers 52M and 52B.
C, 52Y, and 52Bk are set below.

The present embodiment is different from the first embodiment in that a paper transport path for double-sided printing is provided as shown in FIG. 5 in addition to the normal paper transport path as shown in FIG. Different from form. In the present embodiment, a path switching plate 104 is provided between a pair of conveying rollers 101 provided at the paper discharge unit of the fixing unit 8 and a pair of conveying rollers 103 provided further downstream in the conveying direction of the paper P. And a roller 63 as a secondary transfer unit from the transport roller pair 103.
Between the conveyance roller pair 108 provided on the upstream side in the conveyance direction of the paper P,
And transport roller pairs 106 and 107 are provided.

When performing double-sided printing in this embodiment, first, the path switching plate 104 is set to the position shown in FIG. Next, the paper P discharged from the fixing unit 8 is transported halfway by the transport roller pair 103, and the paper P
The conveyance is temporarily stopped just before the rear end of the sheet is discharged from the conveyance roller pair 103. Next, the path switching plate 104 is rotated clockwise as shown in FIG. 5 to rotate the transport roller pair 103 in the reverse direction, and the paper P is supplied to the duplex print transport path 105 by the transport roller pairs 103, 106 and 107. Then, the sheet P is conveyed by the conveying roller pair 108 to the press-contact portion between the roller 63 and the intermediate transfer body 5, so that the sheet P
Can be printed on the back surface of the. Since double-sided printing is possible in this manner, it is possible to contribute to saving paper P.

Also in this embodiment, as shown in FIG. 6, the openable and closable side cover 2 is provided on the side of the side opposite to the surface of the intermediate transfer body 5, so that it can be connected to the above-described frame. The process cartridge can be easily attached and detached without causing interference.

In this embodiment, the process cartridge is pulled out upward as shown in FIG. 6, while the LED arrays 72M, 72C, 72
Y and 72Bk are located in the downward direction opposite to the extraction direction. Therefore, the LED arrays 72M, 72C,
72Y and 72Bk do not hinder the removal of the process cartridge. LED array 72M, 72
C, 72Y, and 72Bk are photosensitive drums 3 due to their characteristics.
M, 3C, 3Y, and 3Bk need to be arranged close to each other, but the configuration as in the present embodiment does not hinder replacement work. Therefore, even if the process cartridge is replaced, the LED arrays 72M, 72C, 72
Since there is no misalignment of Y and 72Bk, the occurrence of color misalignment can be reliably suppressed.

Further, the cleaning means 73 of the present embodiment
As shown in FIG. 7A, M, 73C, 73Y, and 73Bk include containers 74M, 74C, 74Y, and 74Bk, blades 75M, 75C, 75Y, and 75Bk, and screws 76M, 76C, and 76Y as conveying means. 76Bk.

Screws 76M, 76C, 76Y, 76
Bk is, as shown in FIG.
The containers 74M, 74C, 74Y, and 74Bk are connected at one longitudinal end by a connection pipe 77. The connecting pipe 77 is connected to a waste toner container 78 at a lower position.

In this embodiment, since the waste toner container 78 is provided at the lowermost portion of the apparatus main body, the waste toner container 78 does not hinder the replacement of the process cartridge. Further, even when the cleaning means 73M, 73C, 73Y, and 73Bk are not included in the process cartridge and the cleanerless method is not employed, the waste toner can be surely treated. In particular, since the waste toner container 78 is provided at one place at the bottom of the apparatus main body, the complexity of the replacement operation can be reduced as compared with the case where the waste toner storage container 78 is provided near each photosensitive drum. Further, since the present embodiment employs a vertical tandem method, waste toner is supplied to the screw 76M,
After being conveyed to the connecting pipe 77 by 76C, 76Y, 76Bk, the waste toner can be dropped by gravity, and the configuration can be simplified.

(Third Embodiment) Next, a third embodiment of the present invention will be described with reference to FIG. The same parts as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

This embodiment is different from the first embodiment in that the belt-like intermediate transfer member 5 is arranged slightly obliquely as shown in FIG.

As described above, even when the belt-like intermediate transfer member 5 is arranged slightly obliquely, the installation area of the apparatus can be reduced.

Also in this embodiment, the side cover 2 is
Since it is provided on the side surface on the side facing the surface of the intermediate transfer member 5, the replacement of the process cartridge can be easily performed without being hindered by the frame. Therefore, the occurrence of color misregistration can be reliably suppressed.

In the present embodiment, the operation panel 15 is provided at the uppermost position of the side surface provided with the side cover 2. Therefore, the opening / closing direction of the side cover 2, the direction of taking out the discharged paper, and the operation direction of the operation panel 15 when replacing the process cartridge are all in the same direction, thereby providing a laser beam printer with excellent operability. Can be. In addition, the above-described effect can be obtained even if an inclined surface is provided on an upper portion of the side surface of the apparatus main body provided with the side cover 2, and the operation panel 15 is disposed on the inclined surface. That is, the operation panel 15 may be provided on the side where the side cover 2 is provided.

The present invention is also applicable to an image forming apparatus using a non-magnetic one-component developer other than a suspension polymerization toner, for example, an image forming apparatus using another polymerization toner obtained by emulsion polymerization or the like. The same can be applied.

[0081]

As described above, according to the color image forming apparatus of the first aspect, since it is a so-called vertical tandem type color image forming apparatus, the area of the installation surface can be reduced. In addition, since the process cartridge is detachably disposed from the side surface of the belt-shaped intermediate transfer body facing the surface, the process cartridge can be easily replaced and can be securely mounted at an appropriate position. Thus, the occurrence of so-called color shift can be reliably reduced.

According to the color image forming apparatus of the present invention, the L is provided to extend in the axial direction of the electrostatic latent image carrier.
In order to provide the ED array fixedly to the color image forming apparatus, it is necessary to support the LED array at both ends in the axial direction. Since the transfer is performed from the side of the intermediate transfer member facing the surface, the LED
The support of the array does not hinder the exchange. As a result, displacement of the LED array is reliably prevented, and occurrence of so-called color misregistration can be reliably reduced.

According to the color image forming apparatus of the present invention, the process cartridge includes at least the developing means and the electrostatic latent image carrier. From the direction opposite to the direction in which the cartridge is separated from the intermediate transfer member,
Since it is opposed to each surface of the plurality of electrostatic latent image carriers, even when an LED array which needs to be arranged close to the electrostatic latent image carrier is used, the process cartridge The LED array does not become an obstacle when detached. As a result, the process cartridge is securely mounted in the proper position,
Array displacement is reliably prevented, and the occurrence of so-called color misregistration can be reliably reduced.

According to the color image forming apparatus of the present invention, the transfer residual developer on each electrostatic latent image carrier is charged and exposed together with the movement of each electrostatic latent image carrier and the plurality of developing agents are transferred to the developing device. Since the developer is collected by each of the developer carriers, a waste developer container for storing the transfer residual developer is not required. Therefore, when the process cartridge is replaced, the waste developer container is not hindered, and so-called color misregistration can be reliably reduced.

According to the color image forming apparatus of the present invention, the charging means is separated from the electrostatic latent image carrier when the process cartridge is replaced. The replacement of the process cartridge including the cartridge can be easily performed without being hindered by the charging unit. Therefore, the occurrence of so-called color shift at the time of replacing the process cartridge can be reliably prevented.

According to the color image forming apparatus of the present invention, the direction of attaching and detaching the transfer medium supply tray and the direction of discharging the transfer medium to the transfer medium discharge tray are the same as the direction of attaching and detaching the process cartridge. Since the surface is opposed to the surface of the belt-shaped intermediate transfer member provided so that the surface moves substantially in the vertical direction, it does not hinder miniaturization of the apparatus, and also allows the user to attach and detach the transfer medium supply tray. In addition, the workability of taking out the discharged transfer medium can be improved.

According to the color image forming apparatus of the present invention, the operation direction of the operation panel is the same as the direction of attaching and detaching the process cartridge and the transfer medium supply tray, and the direction of discharging the transfer medium to the transfer medium discharge tray. Because of the direction, the operability can be further improved without hindering the miniaturization of the device.

According to the color image forming apparatus of the present invention, since the cleaning means is not included in the process cartridge, the cleaning means does not hinder the replacement of the process cartridge. Therefore,
It is possible to reliably prevent a so-called color shift from occurring when the process cartridge is replaced. Further, since the collected waste developer is transported by the transport unit in the moving axis direction of the electrostatic latent image carrier, after the transport, the developer can be dropped downward by gravity. Even when not included in the process cartridge, the processing of the waste developer can be performed accurately.

[Brief description of the drawings]

FIG. 1 is a schematic sectional side view of a laser beam printer according to a first embodiment of the present invention.

FIG. 2 is a schematic side sectional view showing a state where a side cover of the laser beam printer of FIG. 1 is opened and a process cartridge is replaced.

FIG. 3 shows the photosensitive drum and the LE when the inside of the laser beam printer of FIG. 1 is viewed from the side provided with the side cover of FIG. 1;
FIG. 3 is a diagram illustrating a positional relationship between a D array and a frame.

FIG. 4 is a diagram showing a side cover provided with an operation panel of the laser beam printer of FIG. 1;

FIG. 5 is a schematic sectional side view of a laser beam printer according to a second embodiment of the present invention.

6 is a schematic side sectional view showing a state where a side cover of the laser beam printer of FIG. 5 is opened and a process cartridge is replaced.

7A is a diagram illustrating a configuration of a cleaning unit in the laser beam printer of FIG. 5, and FIG. 7B is a diagram illustrating a transport unit and a waste toner container in the cleaning unit of FIG.

FIG. 8 is a schematic sectional side view of a laser beam printer according to a third embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Laser beam printer 2 ... Side cover 3M, 3C, 3Y, 3Bk ... Photosensitive drum 5 ... Intermediate transfer body 8 ... Fixing unit 9 ... Feeding unit 10 ... Discharge tray 11A, 11B ... Frame 15 ... Operation panel 51M, 51C , 51Y, 51Bk developing device (process cartridge) 52M, 52C, 52Y, 52Bk developing roller 70M, 70C, 70Y, 70Bk cleaning roller 71M, 71C, 71Y, 71Bk charging device 72M, 72C, 72Y, 72Bk LED Array 73M, 73C, 73Y, 73Bk Cleaning means 76M, 76C, 76Y, 76Bk Screw 78 Waste toner collection container 91 Paper feed tray

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G03G 21/10 G03G 15/08 507B 21/00 376 21/00 326 F term (Reference) 2H027 GA03 2H030 AA01 AA05 AA06 AA07 AB02 AD03 BB02 BB42 2H034 CA01 2H071 AA35 AA48 BA04 BA13 DA03 DA08 DA09 DA15 EA04 EA18 2H077 AC16 AD31 BA09 BA10 GA00 GA13

Claims (8)

[Claims] 1. A belt-shaped intermediate transfer member provided so that a surface thereof moves in a substantially vertical direction, and a plurality of electrostatic latent images arranged in a substantially vertical direction along a moving direction of the surface. Carrier, a plurality of charging means for charging each surface of the plurality of electrostatic latent image carriers, and a plurality of exposure means for exposing a charged region on each surface of the plurality of electrostatic latent image carriers And a plurality of developing means including a plurality of developer carriers arranged so as to face each of the plurality of electrostatic latent image carriers, wherein at least the developing means includes a belt as a process cartridge. A color image forming apparatus, wherein the color image forming apparatus is detachably provided to a main body of the apparatus from a side surface portion of the intermediate transfer body facing the surface. 2. An apparatus according to claim 1, wherein said plurality of exposure means includes an LED array extending in an axial direction of said electrostatic latent image carrier and fixed to a main body of said apparatus. Color image forming apparatus. 3. The process cartridge includes at least the developing unit and the electrostatic latent image carrier, and each of the plurality of LED arrays is provided on the electrostatic latent image carrier when the process cartridge is mounted. Each of the plurality of electrostatic latent image carriers is separated from a direction opposite to a direction in which the electrostatic latent image carrier is separated from the intermediate transfer body with respect to a plane including an axis and perpendicular to the surface of the intermediate transfer body. 3. The color image forming apparatus according to claim 2, wherein the color image forming apparatus is disposed so as to face the surface. 4. After transferring a developer image formed on each of the plurality of electrostatic latent image carriers to the intermediate transfer member, a developer remaining on each electrostatic latent image carrier is removed from each electrostatic latent image carrier. 4. The color image forming apparatus according to claim 1, wherein the developer is collected by each of the plurality of developer carriers through charging and exposure together with movement of the latent image carrier. 5. The process cartridge includes at least the developing unit and the electrostatic latent image carrier, and the plurality of charging units are provided on a main body of the apparatus. 5. The color image forming apparatus according to claim 1, wherein the color image forming apparatus is separated from the latent image carrier. 6. A transfer medium supply tray for supplying a transfer medium, and a transfer medium discharge tray on which a transfer medium discharged after completion of an image forming step is mounted, wherein the transfer medium supply tray and the process cartridge are attached and detached. Direction, and the discharge direction of the transfer medium to the transfer medium discharge tray,
The color image forming apparatus according to any one of claims 1 to 5, wherein the surface is in a direction opposed to the surface of the belt-shaped intermediate transfer member provided so as to move along a substantially vertical direction. . 7. An operation panel including various operation buttons and the like, wherein the operation panel is operated by a belt-shaped intermediate transfer member provided such that a surface thereof moves in a substantially vertical direction. 7. The color image forming apparatus according to claim 6, wherein the color image forming apparatus is mounted in a direction facing the surface. 8. A cleaning means for recovering the transfer residual developer on the plurality of electrostatic latent image carriers is provided outside the process cartridge. 8. The color image forming apparatus according to claim 1, further comprising a transport unit configured to transport the latent image carrier in an axial direction.