JP2000298421A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a compact and inexpensive image forming device excellent in the usability of a process cartridge by allowing a housing in which plural image forming units are disposed to contact with/separate from a base unit equipped with an intermediate transfer body. SOLUTION: A core unit 1 being the housing to hold four sets of image forming units consisting of the process cartridges 30Y, 30M, 30C and 30Bk including a photoreceptor drum and optical scanning systems 18Y, 18M, 18C and 18Bk is constituted to contact with/separate from the base unit 2 equipped with the intermediate transfer belt 16 successively transferring images formed on the respective photoreceptor drums. Furthermore, it is constituted to separate upward. Then, a locking hook 21 for holding the core unit 1 in the image forming device is provided in the base unit 2. If a user releases the hook 21 at the time of exchanging the cartridge 30, the core unit 1 is automatically separated upward from the base unit 2, whereby the cartridge 30 is extremely easily exchanged.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a color printer,
The present invention relates to an image forming apparatus capable of multicolor printing, such as a color copying machine.

[0002]

2. Description of the Related Art Conventionally, as an image forming apparatus capable of multicolor printing such as a color copying machine and a color printer, there is a multiplex image forming apparatus described in Japanese Patent Application Laid-Open No. 63-271275. In recent years, speeding up is often required, and from that point of view, the form of the image forming apparatus described in the publication is used.

In addition, it is required that a user can easily and surely replace a consumable such as a process cartridge.

As shown in FIG. 5, the basic structure of a conventional image forming apparatus is such that two upright side plates 51, 52 are connected by stays 53, 54, 55, 56 disposed therebetween to form a housing. Optical scanning system 5 for forming and forming a latent image on a photosensitive drum in the housing.
7, a process cartridge 58 including a photosensitive drum, an intermediate transfer body 59 provided with a primary transfer roller for sequentially transferring toner images formed on each photosensitive drum, a feeding unit 60 for feeding sheets one by one, A transfer / conveying unit 61 provided with a secondary transfer roller for collectively transferring the toner image on the intermediate transfer body 59 to the separated sheet while conveying the sheet; fixing for fixing the toner image to the transferred sheet Means 62 and a discharging means 63 for discharging the fixed sheet are provided.

[0005]

However, in the conventional image forming apparatus, there are the following problems in a method of replacing a process cartridge which is a consumable item.

When the process cartridge 58 is replaced, the transfer / transporting means 61 must be separated from the intermediate transfer member 59, and then the intermediate transfer member 59 must be separated from the process cartridge 58. Because of that, the work was complicated.

Further, below the process cartridge 58,
Since a space is required for separating the transfer / transporting means 61 and the intermediate transfer member 59, there is a problem that the size of the apparatus itself increases. In particular, as shown in FIG. 5, in a configuration in which the intermediate transfer member 59 is rotated and separated about the rotation axis of the drive roller 64 on which the intermediate transfer member 59 is stretched, the process cartridge 58Bk near the rotation center is provided. Photoreceptor drum and intermediate transfer member
When the gap between the surfaces of the process cartridge 59 is set to a predetermined minimum size, the process cartridge 58 farthest from the rotation center is set.
There is a problem that the gap between the Y photoreceptor drum and the surface of the intermediate transfer member 59 is more than necessary. Further, in order to satisfy the separating operation of the intermediate transfer member 59, the transfer / conveying means 61 disposed below the intermediate transfer member 59 must be further separated.

The present invention has been made in view of the above problems, and has as its object to provide a small-sized full-color image forming apparatus which is excellent in usability.

[0009]

In order to achieve the above object, a typical configuration of the present invention is a plurality of image forming apparatuses each including an image carrier and an exposing means for exposing the charged image carrier. The unit is disposed in a single housing, and the housing can be moved toward and away from a base unit including an intermediate transfer body on which images formed on the respective image carriers are sequentially transferred in an overlapping manner. Features.

[0010] According to the above construction, the housing provided with the plurality of image forming units including the image carrier can be separated from the base unit provided with the intermediate transfer member (for example, can be separated and moved in parallel). Therefore, it is possible to provide a small and inexpensive image forming apparatus which is excellent in usability of the process cartridge.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of an image forming apparatus to which the present invention is applied will be described in detail with reference to the drawings. The following embodiment exemplifies an electrophotographic image forming apparatus capable of forming a full-color image.

First Embodiment An image forming apparatus according to a first embodiment will be described in detail with reference to FIGS.
FIG. 1 is a schematic sectional view showing a schematic configuration of the full-color image forming apparatus according to the first embodiment. In this embodiment,
FIG. 1 illustrates a full-color image forming apparatus using four photosensitive drums and an intermediate transfer belt.

As shown in FIG. 1, in this image forming apparatus, a cassette 10 for stacking and storing a plurality of recording sheets P as a transfer material is detachably attached to a lower portion of the apparatus. The recording sheets P stacked and stored in the cassette 10 are fed by a feed roller.
Feeded by 11. The fed recording sheet P is separated one by one by a pair of retard rollers 12 and
The sheet 13 is conveyed to a pair of registration rollers 14. When the recording sheet P is conveyed, the registration roller pair 14 stops rotating, and the recording sheet P is skewed by being hit against the nip.

Process cartridges 30Y, 30M, 30 as image forming means including a photosensitive drum as an image carrier
In the case of the four-drum full-color system, four colors of C, 30Bk are arranged in parallel, as shown in FIG. 1, for yellow, magenta, cyan, and black. Each process cartridge 30Y,
Reference numerals 30M, 30C, and 30Bk denote photosensitive drum 31, charging means 32 for uniformly charging the surface of the photosensitive drum, and developing means for developing a latent image formed on the photosensitive drum, respectively. 33, a cleaning means 34 for removing the developer and the like remaining on the photosensitive drum is integrally provided (see FIG. 4).

Each of the process cartridges 30Y, 30M, 30
Optical scanning systems 18Y, 18M, 18C and 18Bk as exposure means are provided for C and 30Bk, respectively, and a toner image is formed on a photosensitive drum for each color in accordance with an image signal. The toner images of the respective colors formed on the intermediate transfer belt 16 are sequentially transferred.

Thereafter, the toner image on the intermediate transfer belt 16 is transferred to the recording sheet P sent out by the registration roller pair 14 at a predetermined timing by a secondary transfer roller.
Transcribed by 17. After the recording sheet P to which the toner image has been transferred is fixed by the fixing device 15, the discharge roller pair 19
a and 19b are discharged and stacked.

In the present image forming apparatus, the core unit 1 which is a housing holding four image forming units including the process cartridge 30 including the photosensitive drum 31 and the optical scanning system 18 includes the photosensitive drums. Base unit 2 including intermediate transfer belt 16 for sequentially transferring images formed on 31
It is configured to be able to approach and separate from. More specifically, it is configured so as to be separated upward in parallel. Hereinafter, a detailed description will be given with reference to FIGS.

FIG. 2 is a diagram showing a state when the process cartridge is replaced. The core units 1 (1a, 1b) on which the process cartridges 30Y, 30M, 30C, and 30Bk each including the photosensitive drum 31 and the like are disposed, have rotation support shafts 3a,
b are provided outside the process cartridges 30Y, 30M, 30C, and 30Bk. The rotation support shafts 3a, 3b
Is located on a plane defined by the rotation axis of each photosensitive drum 31 (the center line shown in FIGS. 1 and 3).

Further, each process cartridge 30Y, 30
M, 30C, and 30Bk are configured to be detachable from the core unit 1, as shown in FIG. Links 4a, 4b are provided on the rotation support shafts 3a, 3b on the core unit 1 side.
Are swingably supported, and the other ends of the links 4a, 4b are rotatably fitted to the rotation support shafts 5a, 5b on the base unit 2 side.

The rotation support shaft 3a on the core unit 1 side,
3b engages with the concave groove 6 (see FIG. 4) of the base unit 2 in the image forming state, that is, in the state where the photosensitive drum 31 and the intermediate transfer belt 16 are in contact with each other (the state shown in FIG. 1). Position is secured.

Reference numeral 21 shown in FIG. 4 is a locking hook for holding the core unit 1 in the image forming state with respect to the base unit 2. The locking hook 21 is held in a predetermined posture (posture shown in FIG. 4) by a tension spring 23 and a stopper 24 around a shaft 22 as a rotation center. There are a total of four locking hooks 21 at the shaft ends of the rotation support shafts 3a and 3b of the core unit 1 (only two positions are shown in FIGS. 1 and 3).

The rotation support shaft 3a on the core unit 1 side,
Reference numeral 3b also functions as a locking shaft (locking portion) for locking the locking hook 21 on the base unit 2 side. The core unit 1 is always urged in a direction away from the base unit 2 by the urging force of a torsion coil spring 25 hung on the rotation support shafts 3a and 3b. Reference numeral 26 denotes a stopper for suppressing the links 4a and 4b from rotating more than necessary.

With the above configuration, the user can remove the locking hook 21 when replacing the process cartridge 30, and
Since the core unit 1 is automatically separated from the base unit 2 upward and parallel as shown in FIG. 3, the replacement is extremely easy.

Conversely, when the core unit 1 is set on the base unit 2, a force is applied in the direction of arrow A in FIG.
It is sufficient to press until the locking hook 21 on the base unit 2 side is locked.

Also, unlike the conventional apparatus, there is no need for a separation space below the process cartridge, and no separation mechanism of the transfer / transporting means is required.

[Other Embodiments] In the above embodiment,
As a process cartridge detachably mountable to the image forming apparatus, a process cartridge having a photosensitive drum and a charging unit, a developing unit, and a cleaning unit as process units acting on the photosensitive drum is exemplified. However, the present invention is not limited to this. For example, a process cartridge having any one of the above-mentioned process means may be used.

Further, in the above-described embodiment, the configuration in which the process cartridge including the photosensitive drum is detachable from the image forming apparatus is exemplified. However, the present invention is not limited to this. An apparatus having a configuration in which the respective components are incorporated, or an apparatus having a configuration in which the respective components such as the photosensitive drum can be detachably attached may be used.

In the above-described embodiment, a printer is exemplified as an image forming apparatus. However, the present invention is not limited to this. For example, another image forming apparatus such as a copying machine or a facsimile apparatus may be used. The same effects can be obtained by applying the present invention to the image forming apparatus.

The present invention can also be applied to an image forming apparatus for sequentially transferring toner images of a plurality of colors from a plurality of photosensitive drums onto a transfer material carried and conveyed on a transfer belt as a transfer material carrier.

[0030]

As described above, according to the present invention,
Since the housing in which a plurality of image forming units including the image carriers are disposed can be moved toward and away from the base unit having the intermediate transfer body (for example, can be moved in and out of parallel), each of the image carriers is moved to the intermediate position. It is possible to provide a small and inexpensive image forming apparatus which has an equal space between the transfer member and the image forming apparatus, which is excellent in usability, for example, for exchanging a process cartridge.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view illustrating a schematic configuration of an image forming apparatus according to a first embodiment.

FIG. 2 is a perspective view illustrating a state where a process cartridge is attached and detached in the image forming apparatus.

FIG. 3 is an explanatory diagram showing a state in which a core unit including the process cartridge is parallel and separated from a base unit having an intermediate transfer belt and the like.

FIG. 4 is an explanatory view of coupling of a locking portion between the core unit and the base unit.

FIG. 5 is an explanatory diagram of a conventional image forming apparatus.

[Explanation of symbols]

P ... recording sheet 1 ... core unit 2 ... base unit 3a, 3b ... rotation support shaft 4a, 4b ... link 5a, 5b ... rotation support shaft 6 ... groove 10 ... cassette 11 ... feeding roller 12 ... retard roller pair 13: Conveying roller pair 14: Registration roller pair 15: Fixing device 16: Intermediate transfer belt 17: Secondary transfer roller 18, 18Y, 18M, 18C, 18Bk: Optical scanning system 19a, 19b: Discharge roller pair 21: Locking hook 22 ... shaft 23 ... tension spring 24 ... stopper 25 ... coil spring 26 ... stopper 30, 30Y, 30M, 30C, 30Bk ... process cartridge 31 ... photosensitive drum 32 ... charging means 33 ... developing means 34 ... cleaning means

Claims (6)

[Claims] 1. A plurality of image forming units each including an image carrier and an exposure unit for exposing the charged image carrier, are provided in a single housing, and the housing includes a plurality of image carriers. An image forming apparatus comprising: a base unit having an intermediate transfer body on which images formed on a body are sequentially superimposed and transferred; 2. The image forming apparatus according to claim 1, wherein the housing is capable of coming into contact with and separating from the base unit in parallel. 3. The image forming apparatus according to claim 1, wherein the locking portion of the housing with respect to the base unit is provided on the same plane as a plane formed by a rotation axis of the image carrier.
Or the image forming apparatus according to claim 2. 4. The image forming unit includes: an image carrier; a charging unit for uniformly charging the image carrier as a process unit acting on the image carrier; and an image forming unit formed on the image carrier. A process cartridge that integrally includes at least one of a developing unit that develops a latent image and a cleaning unit that removes a developer and the like remaining on the image carrier, wherein the process cartridge is provided with respect to the housing. 4. The device according to claim 1, wherein the device is detachable.
The image forming apparatus according to any one of the above. 5. The image forming apparatus according to claim 1, wherein the image on the image carrier formed by each image forming unit is sequentially transferred to a belt-shaped intermediate transfer body, and the images on the intermediate transfer body are collectively transferred. The image forming apparatus according to any one of claims 1 to 4, wherein the image forming apparatus is an image forming apparatus that transfers an image to a transfer material. 6. The image forming apparatus is an image forming apparatus for sequentially transferring an image formed on each of the image forming units on the image carrier to a transfer material carried and conveyed by the transfer material carrier. The image forming apparatus according to claim 1, wherein: