JP2004117989A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus which prevents an image area of an image carrier contained in a process cartridge from being damaged when the process cartridge is loaded or unloaded. <P>SOLUTION: In the image forming apparatus equipped with a process cartridge which contains the image carrier 1 and is freely detachable, a freely openable and closable cover part 3 as a loading/unloading opening for the process cartridge, and a guide part 2 which is projected from the cover part 3 to guide the loading and unloading of the process cartridge, the image carrier 1 has an image area which is provided at a lengthwise intermediate part and where image formation processing is performed and non-image areas 1a which are provided at both the lengthwise ends and where the image formation processing is carried out and the guide part 2 is provided with an abutment part 20 where it abuts against the non-image area 1a of the image carrier. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an image forming apparatus provided with a process cartridge including an image carrier in a detachable manner.
[0002]
[Prior art]
As a conventional image forming apparatus, for example, there is an image forming apparatus shown in FIG. This image forming apparatus includes a recording paper 101 as a recording medium, a paper feed tray 102 for holding the recording paper 101, and a paper feed roller 103 for feeding the recording paper 101 from the paper feed tray 102 to the inside of the image forming apparatus. A transport roller 104 that transports the recording paper 101 that has passed through the paper feed roller 103, a photosensitive drum 105 serving as an image carrier, a process cartridge 106 including the photosensitive drum 105 and including image forming means such as toner, A transfer roller 107 for transferring the developed image formed on the photosensitive drum 105 to the recording paper 101, a fixing device 108 for fixing an unfixed image transferred to the recording paper 101, and a recording paper 101 on which the image is fixed are conveyed. The printer includes a paper discharge roller 109 and a paper discharge tray 110 that holds the conveyed recording paper 101.
[0003]
The image forming process by this image forming apparatus is as follows. The recording paper 101 passes through the transport path A one by one from a paper feed tray 102 by a paper feed roller 103 and is transported to a transport roller 104. When the position of the leading end of the developed image formed on the photosensitive drum 105 serving as the image carrier reaches the position of the transfer nip where the photosensitive drum 105 serving as the image carrier and the transfer roller 107 come into contact with each other, recording is performed. Timing is set so that the leading edge of the paper 101 is transported to the transfer nip portion. Note that an image forming unit is configured by the photosensitive drum 105 serving as an image carrier, the transfer roller 107, and the like.
[0004]
After the developed image on the photosensitive drum 105 serving as the image carrier is transferred onto the recording paper 101 in the transfer nip portion in this manner, the recording paper 101 is separated from the photosensitive drum 105 serving as the image carrier, and is fixed by a fixing device. It is transported to 108. In the fixing device 108, the recording paper 101 is nipped between the heating member and the pressure roller, and the unfixed image transferred to the recording paper 101 is fixed. Thereafter, the recording paper 101 on which the toner image has been fixed passes through the conveyance path B, and is discharged by a discharge roller 109 to a discharge tray 110 of the image forming apparatus main body.
[0005]
Here, it is necessary to replace the process cartridge 106 when the process cartridge 106 is used a certain number of times depending on the service life such as toner consumption. Therefore, the process cartridge 106 is detachable from the image forming apparatus, and is provided so that it can be easily replaced. FIG. 6 shows a schematic diagram of the attachment / detachment of the process cartridge. A guide portion 112 for guiding the attachment and detachment of the process cartridge 106 is provided on an opening / closing cover 111 provided in the image forming apparatus and serving as an attachment / detachment opening of the process cartridge 106. It is detached from the image forming apparatus.
[0006]
However, if the photosensitive drum 105 included in the process cartridge 106 is exposed at the time of attachment / detachment, the photosensitive drum 105 may be contaminated, scratched, or deteriorated by being exposed to light. For this reason, in many cases, the process cartridge 106 is provided with a cover member 113 as a protection member for covering the photosensitive drum 105 at the time of attachment / detachment, in order to protect the photosensitive drum 105 and prevent light from entering the inside of the process cartridge 106.
[0007]
As shown in FIG. 6, the cover member 113 is at a position for protecting the photosensitive drum 105 before the process cartridge 106 is mounted on the image forming apparatus main body, and the process cartridge 106 is mounted on the image forming apparatus main body. Sometimes (in the direction of arrow C), the photosensitive drum 105 is moved to a retracted position. Then, as shown in FIGS. 7, 8, and 9, the process cartridge 106 is pulled out from the inside of the image forming apparatus main body in the direction of arrow D at the time of replacement.
[0008]
[Problems to be solved by the invention]
However, the conventional image forming apparatus has the following problems when the process cartridge 106 is detached from the image forming apparatus main body.
[0009]
When the process cartridge 106 is inserted into or removed from the image forming apparatus, the cover member 113 for protecting the photosensitive drum 105 serving as an image carrier or shielding light from the inside of the process cartridge 106 may be opened. The image area of the photosensitive drum 105 may be damaged by the guide portion 112 provided on the opening / closing cover 111 of the image forming apparatus main body for guiding the process cartridge 106.
[0010]
Further, when the process cartridge 106 is inserted into or removed from the image forming apparatus, the longitudinal direction of the process cartridge 106 is regulated inside the image forming apparatus by the housing of the image forming apparatus. There is no means for regulating the longitudinal direction of the process cartridge 106 at a position distant from the housing of the image forming apparatus, and the guide portion 112 for guiding the process cartridge 106 provided on the opening / closing cover 111 of the image forming apparatus serves as an image carrier. The image area of the photosensitive drum 105 may be damaged.
[0011]
SUMMARY An advantage of some aspects of the invention is to prevent damage to an image area of an image carrier included in a process cartridge when the process cartridge is attached or detached. It is an object of the present invention to provide an image forming apparatus capable of performing the above.
[0012]
[Means for Solving the Problems]
In order to achieve the above object, according to the present invention, a detachable process cartridge including an image carrier, an openable / closable cover serving as an attaching / detaching opening of the process cartridge, and a projecting portion provided on the cover are provided. And an image forming apparatus comprising: a guide portion for guiding attachment and detachment of the process cartridge, wherein the image carrier has an image area for performing image forming processing provided at an intermediate portion in a longitudinal direction, and both end portions in a longitudinal direction. And a non-image area where image forming processing is not performed, provided in the guide section, wherein the guide section is provided with an abutting section at a position where the abutting section is in contact with the non-image area of the image carrier. I do.
[0013]
With the above configuration, when the process cartridge is attached or detached, the non-image area of the image carrier including the process cartridge and the contact portion provided on the guide portion come into contact with each other. A space is formed, and the process cartridge can be attached and detached without damaging the image area of the image carrier.
[0014]
Further, the process cartridge may include an image forming unit for forming an image in addition to the image carrier.
[0015]
The present invention only needs to be a process cartridge provided with at least an image carrier, and can be usefully used in a process cartridge provided with other image forming means in addition to the image carrier.
[0016]
Further, it is preferable that the contact portion has a first contact portion that contacts a non-image area of the image carrier, and a second contact portion that contacts an end surface of the image carrier.
[0017]
With this configuration, when the process cartridge is attached and detached, both end surfaces of the image bearing member and the second contact portion of the guide portion are in contact with each other, so that the longitudinal movement of the process cartridge can be restricted. If the process cartridge moves in the longitudinal direction, the image area of the image carrier may be damaged, which can be prevented.
[0018]
Preferably, the surface of the contact portion is formed of a resin having good slidability.
[0019]
Here, the resin having good slidability means a resin having a low coefficient of friction, and examples thereof include POM (polyacetal), PFC (fluororesin), and PA (polyamide). By forming the surface of the contact portion with a resin having good slidability, the process cartridge can be smoothly attached to and detached from the image forming apparatus.
[0020]
Although the present invention is based on the above configuration, the present invention also includes combinations of these as much as possible.
[0021]
BEST MODE FOR CARRYING OUT THE INVENTION
Preferred embodiments of the present invention will be illustratively described in detail below with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention thereto unless otherwise specified. Absent.
[0022]
(First Embodiment)
The image forming apparatus according to the first embodiment will be described with reference to FIGS. FIG. 1 is a detailed view of the inside of the image forming apparatus according to the present embodiment, and FIG. 2 is a schematic perspective view of the image forming apparatus. Note that the mechanism as the image forming apparatus is the same as that of the image forming apparatus shown in FIG. 5, and redundant description of equivalent components will be omitted.
[0023]
A process cartridge (not shown) of the image forming apparatus according to the first embodiment includes a photosensitive drum 1 which is an image carrier, similarly to the image forming apparatus shown in FIG. The intermediate portion in the longitudinal direction of the photosensitive drum 1 is an image area where an image forming process is performed, and both end portions 1a in the longitudinal direction are non-image areas where the image forming process is not performed. Further, the image forming apparatus is provided with an openable and closable cover 3 serving as a detachable opening of the process cartridge, and a guide portion 2 for guiding the detachment of the process cartridge is provided on the openable and closable cover 3. A contact portion 20 is provided on the guide portion 2 at positions corresponding to the non-image areas 1 a at both ends of the photosensitive drum 1. The contact portion 20 is provided substantially parallel to the opening / closing cover 3.
[0024]
In the image forming apparatus according to the first embodiment, the non-image area 1a of the photosensitive drum 1 and the abutting portion 20 of the guide section 2 come into contact when the process cartridge is attached / detached. The distance can always be provided between the image area of the photosensitive drum 1 and the opening / closing cover 3 without damaging the image cartridge, and the process cartridge can be attached and detached without damaging the image area of the photosensitive drum 1.
[0025]
(Second embodiment)
An image forming apparatus according to the second embodiment will be described with reference to FIGS. FIG. 3 is a detailed view of the inside of the image forming apparatus according to the present embodiment, and FIG. 3 is a schematic perspective view of the image forming apparatus. Note that, similarly to the first embodiment, the mechanism as the image forming apparatus is the same as that of the image forming apparatus shown in FIG. 5, and a redundant description of equivalent components will be omitted.
[0026]
A process cartridge (not shown) of the image forming apparatus according to the second embodiment includes a photosensitive drum 1 serving as an image carrier, similarly to the image forming apparatus of the first embodiment. The intermediate portion in the longitudinal direction of the photosensitive drum 1 is an image area where an image forming process is performed, and both end portions 1a in the longitudinal direction are non-image areas where the image forming process is not performed. Further, the image forming apparatus is provided with an openable and closable cover 3 serving as a detachable opening of the process cartridge, and a guide portion 2 for guiding the detachment of the process cartridge is provided on the openable and closable cover 3. And the contact part 20 is the structure which has the 1st contact part 20a and the 2nd contact part 20b here. That is, the guide portion 2 is substantially parallel to the opening / closing cover 3 and is in contact with the non-image area 1a of the photosensitive drum 1. The first contact portion 20a is substantially perpendicular to the first contact portion 20a. A second contact portion 20b is provided for contacting the end surface 1b.
[0027]
The contact portion 20 is different from the contact portion shown in the first embodiment in that a step is provided and the thickness on the side surface is increased. By providing this step, it is possible to support the photosensitive drum 1 from below and from the side and receive a thrust load.
[0028]
In the image forming apparatus according to the second embodiment, when the process cartridge is attached and detached, the lower surface of the non-image area 1a of the photosensitive drum 1 contacts the first contact portion 20a, and the end face 1b of the photosensitive drum 1 Is in contact with the second contact portion 20b of the guide portion 2. Therefore, when the process cartridge is attached or detached, it is possible to prevent not only the photosensitive drum 1 from hitting the open / close cover 3 but also to prevent the photosensitive drum 1 from moving in the longitudinal direction. Therefore, the process cartridge can be more reliably attached and detached without damaging the image area of the photosensitive drum 1.
[0029]
【The invention's effect】
As described above, according to the present invention, the process cartridge can be attached and detached without damaging the image area of the image carrier included in the process cartridge, and high-quality image formation can be maintained.
[Brief description of the drawings]
FIG. 1 is a detailed view of the inside of an image forming apparatus according to a first embodiment of the present invention.
FIG. 2 is a schematic perspective view of the image forming apparatus according to the first embodiment of the present invention.
FIG. 3 is a detailed view of the inside of an image forming apparatus according to a second embodiment of the present invention.
FIG. 4 is a schematic perspective view of an image forming apparatus according to a second embodiment of the present invention.
FIG. 5 is a schematic configuration diagram of a conventional image forming apparatus.
FIG. 6 is a schematic diagram illustrating a process cartridge mounted in a conventional image forming apparatus.
FIG. 7 is a schematic diagram of a process cartridge detached from a conventional image forming apparatus.
FIG. 8 is a schematic perspective view of a conventional image forming apparatus.
FIG. 9 is a schematic perspective view of a conventional image forming apparatus.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Photosensitive drum 1a Non-image area 1b End face 2 Guide part 3 Opening / closing cover 20 Contact part 20a First contact part 20b Second contact part 101 Recording paper 102 Paper feed tray 103 Paper feed roller 104 Transport roller 105 Photosensitive drum 106 Process Cartridge 107 Transfer roller 108 Fixing device 109 Discharge roller 110 Discharge tray 111 Opening / closing cover 112 Guide portion 113 Cover member

Claims (4)

A process cartridge that includes an image carrier and is detachable;
An openable and closable cover which is a detachable opening of the process cartridge,
A guide portion protruding from the cover portion and guiding the attachment and detachment of the process cartridge.
The image carrier has an image area for performing image forming processing provided at an intermediate portion in the longitudinal direction, and a non-image area for not performing image forming processing provided at both ends in the longitudinal direction,
An image forming apparatus, wherein the guide section is provided with a contact section at a position where the guide section contacts a non-image area of the image carrier. The image forming apparatus according to claim 1, wherein the process cartridge includes an image forming unit for forming an image, in addition to the image carrier. The said contact part has the 1st contact part which contacts the non-image area | region of the said image carrier, and the 2nd contact part which contacts the end surface of the said image carrier, The Claim 1 or Claim 2 characterized by the above-mentioned. The image forming apparatus according to claim 2. The image forming apparatus according to claim 1, wherein a surface of the contact portion is formed of a resin having good slidability.

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