JP2002311688A - Processing cartridge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a spacer device with which an electrifying member and a photoreceptor drum come into contact without pulling out a spacer by a user with a simple constitution. SOLUTION: (1) A separating member wound on the electrifying member is taken up by an image carrier together with the rotation of the image carrier, so that the image carrier and the electrifying member come into contact with each other. (2) The separating member wound on the image carrier or the electrifying member is taken up by a take-up member by the rotation of the take-up member rotated together with the rotation of the image carrier, so that the image carrier and the electrifying member come into contact with each other.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for contacting and separating a charging member of a process cartridge and an image carrier in an electrophotographic image forming apparatus.

[0002]

2. Description of the Related Art FIG. 8 shows a longitudinal section of a process cartridge which is detachable from an electrophotographic image forming apparatus main body.

This process cartridge is formed by integrally incorporating a photosensitive drum (image carrier) 2, a developing device 3, a cleaning device 4, and a charging member 5 in a cartridge container 1. The photosensitive drum 2 is rotatably supported by the cartridge container 1. Developing device 3
Denotes a toner container 31 for storing toner and a developing sleeve 3
2, a cleaning device 4 having a regulating blade 33, etc.
Are the cleaning container 41 and the cleaning blade 42
Etc.

[0004] The charging member 5 is formed of a conductive layer formed on the outer peripheral surface of a metal core 51. The photosensitive drum 2 is pressed against the photosensitive drum 2 with a predetermined pressing force, and is rotated by the rotation of the photosensitive drum 2. In this charging member 5,
By applying a bias voltage via a power supply (not shown) and rotating the photosensitive drum 2, the surface of the photosensitive drum 2 is charged to a predetermined potential.

[0005] The contact charging method as described above uses the charging member 5.
However, since the photosensitive drum 2 is constantly pressed against the photosensitive drum 2 with a predetermined pressing pressure, the photosensitive drum 2 and the charging member 5 may come into strong contact with each other due to an impact at the time of transport of the process cartridge, and may be damaged or deformed. . Further, when the charging member 5 and the photosensitive drum 2 rub during transportation, an image defect called a rubbing memory occurs at the beginning of use of the process cartridge, and a defective image is printed out before recovery.

For this reason, a spacer 6 for separating the charging member 5 from the photosensitive drum 2 is provided to prevent a problem at the time of conveyance, and the user is required to remove the spacer immediately before mounting the process cartridge in the image forming apparatus. Like that.

[0007]

However, if the user forgets to remove the spacer, the process cartridge as well as the image forming apparatus main body may be damaged. In the first place, forcing the user to remove the spacer is incompatible with usability. Further, the removed spacer is unnecessary, and disposal as dust causes an environmental problem. Furthermore, the photosensitive drum and the charging member are rubbed by an impact when the spacer is removed,
A rubbing memory may occur.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and separates a charging member from a photosensitive drum and mounts a process cartridge on an image forming apparatus until the process cartridge is mounted on the image forming apparatus. The purpose of the present invention is to provide a spacer device with a simpler configuration in which the photosensitive drum is driven to rotate and the separation distance is gradually reduced, so that the charging member contacts the photosensitive drum without the user having to remove the spacer. is there.

[0009]

Means for Solving the Problems In order to achieve the above object, according to the invention of the present application, of the means for performing the image forming step, at least the image carrier and the image carrier in contact with the image carrier are contacted. In a process cartridge having a charging member to be charged and attached to and detached from the image forming apparatus, the image carrier and the charging member are separated from each other by a separation member wound around the charging member. The member is wound around the image carrier, and the image carrier and the charging member come into contact with each other.

In this case, the separating member is a band-shaped member having a predetermined thickness and length, one end of which is connected to the image carrier, and is wound around the charging member or a core of the charging member. Further, the rotation of the image carrier may be performed so as to wind around the image carrier.

Further, among the means for performing the image forming step, a process cartridge which has at least an image carrier and a charging member which contacts the image carrier and charges the image carrier, and which is attached to and detached from the image forming apparatus, The image carrier and the charging member are separated by a separating member wound around the image carrier or the charging member, and with the rotation of the image carrier or the charging member, a winding member for winding the separating member rotates,
The separation member is wound around a winding member, and the image carrier and the charging member come into contact with each other.

In this case, one end of the separating member may be connected to the winding member so as to wind around the winding member.

According to the above configuration, the photosensitive drum and the charging member come into strong contact with each other due to the impact during the transfer of the process cartridge, and may be damaged or deformed. An image defect called a rubbing memory does not occur.

Further, unlike the case where the charging member is separated from the photosensitive drum by using the spacer, the user is not forced to remove the spacer. Further, by forgetting to remove the spacer, there is no possibility that the image forming apparatus main body as well as the process cartridge is damaged. Furthermore, the usability can be remarkably improved without the photosensitive drum and the charging member being rubbed by the impact at the time of removing the spacer.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) A first embodiment will be described below with reference to FIGS.

The parts of the process cartridge 1 which is detachable from the main body of the image forming apparatus are the same as those of the conventional example shown in FIG.
Description will be made using the same reference numerals.

The image formation of the image forming apparatus and the process cartridge of the present invention will be described.

The image forming apparatus 11 is connected to a host 12 such as a personal computer or a workstation.

Immediately after the process cartridge 1 is inserted into the image forming apparatus main body and the power is turned on, the image forming apparatus starts rotating the drive motor. In the heat fixing device 13, a heat source such as a halogen heater disposed inside the heating roller 14 is controlled by a control unit, and the surface temperature of the heating roller is raised to a standby temperature. During that time, the remaining amount of toner in the process cartridge is detected and the electric system is checked.
The preparatory rotation from when the power is turned on until the surface temperature of the heating roller reaches the standby temperature is called pre-multiple rotation.

Upon receiving a print request from the host 12, the image forming apparatus 11 develops image data from the host into bitmap data by the controller. Further, the medium P is fed from the recording material storage unit 15 and is conveyed to the registration rollers 16. The medium P is temporarily stopped by the registration roller 16, and the start of the scanner motor and the
It waits until the preparatory rotation (so-called pre-rotation) for stabilizing the potential of the photosensitive drum 2 is completed, that is, until the printer unit is ready for image writing.

When the pre-rotation is completed, the organic semiconductor (OP)
C) Photoconductor drum 2 as an image carrier having a photosensitive layer such as
After being uniformly charged by the contact charging member 5, the laser beam 17 modulated in accordance with the above-described image signal is irradiated to obtain a desired electrostatic latent image. This electrostatic latent image is stored in the developing device 3
The developer adhering to the thin layer on the developing sleeve 32 in the inside,
The electrostatic latent image is developed by flying from the developing sleeve and adhering to the photosensitive drum by a predetermined developing bias voltage applied to the developing sleeve from the AC bias source, and is visualized as a toner image.

At the same time, the medium P is transported from the registration rollers to the transfer section. Here, the toner image is electrostatically transferred to the medium P by a transfer unit 18 such as a transfer roller.

The medium P to which the toner image has been transferred is conveyed to the heat fixing device 13 and is permanently fixed. Thereafter, the medium P is discharged from the paper discharge unit, and a desired print image is obtained.

The toner remaining on the photosensitive drum without being transferred is cleaned by a cleaning blade 42 (so-called post-rotation), and the same image forming process is repeated.

Next, the parts relating to the separating member will be described in detail.

FIGS. 2 and 3 show the relationship between the photosensitive drum 2, the charging member 5, and the separating member 7. FIG. Both ends of the charging member are held by a pressing device 52 and are pressed at a predetermined pressure in the direction of the rotation center of the photosensitive drum.

When the process cartridge 1 is transported, that is, before the process cartridge 1 is inserted into the image forming apparatus 11, the photosensitive drum 2 and the charging member 5 are separated by the separating member 7 as shown in FIG. The separation member 7 has a predetermined thickness and length, and is wound around the core metal 51 of the charging member. This thickness and length are the distance required to separate the photosensitive drum and the charging member, and as described below, when the separating member is wound around the photosensitive drum, the core metal of the separating member and the charging member is It is determined by the distance for avoiding interference and the distance to each member arranged around.

One end of the separating member 7 is connected to an opposing photosensitive drum. Of course, since this position corresponds to the position of the core metal of the charging member, it is outside the image area and does not affect image formation. It is also important that the photosensitive drum is made of a material that does not have a scientific influence and that it is electrically insulated.

Immediately after the process cartridge 1 is inserted into the main body of the image forming apparatus and the power is turned on, the image forming apparatus rotates the drive motor to prepare the heating roller 14 to raise the surface temperature to the standby temperature. Start rotation. Therefore, the photosensitive drum 2 also starts rotating.

As the photosensitive drum rotates, one end of the separating member is connected to the photosensitive drum, so that the photosensitive drum starts winding the separating member. Separating member 7
Gradually decreases the radius, and the separation distance between the photosensitive drum and the charging member also gradually decreases.

Finally, at the time of conveyance, the separating member 7 wound around the core of the charging member is wound around the photosensitive drum and collected, and the photosensitive drum 2 and the charging member 5 are separated from each other by the pressing device 5.
2 is pressed at a predetermined pressure necessary for image formation. This is shown in FIG.

The time required during this time is much shorter than the time spent in the previous multiple revolutions.

One end of the separating member on the side of the charging member wound around the core metal is treated with an adhesive or the like so as to be wound around the photosensitive drum and collected. It is important that the adhesive and the like be made of a material that does not scientifically affect the photosensitive drum. An auxiliary member that treats the entire area of the separation member with an adhesive or the like so as to be more easily collected, as shown in FIG. 4, a guide 71 is provided, or the separation member wound around the photosensitive drum is appropriately pressed. A configuration in which 72 is provided can also be adopted.

In this embodiment, the charging member has been described as a contact charging roller. However, the present invention can be applied to a brush type charging member. Even in such a case, it is apparent that the deformation of the brush and the image defect due to the pressure contact between the photosensitive drum and the brush charging member can be avoided when the process cartridge is transported.

(Second Embodiment) Hereinafter, a first embodiment will be described with reference to FIGS. The same parts as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

As shown in FIGS. 5 and 6, in the second embodiment, a winding member 8 for winding a separating member 7 for separating the charging member and the photosensitive drum is disposed inside the process cartridge. Has been established.

At the time of transporting the process cartridge shown in FIG.
The separation member 7 has a predetermined thickness and length, and is wound around the core metal 51 of the charging member. This thickness and length are the distance required to separate the photosensitive drum and the charging member,
And, as described later, when the separating member is wound around the winding member 8, the separating member and the core metal of the charging member,
Or, a member disposed around the photosensitive drum or the like,
Determined by a distance sufficient to avoid interference.

One end of the separating member is connected to the winding member 8.

Immediately after the process cartridge 1 is inserted into the main body of the image forming apparatus and the power is turned on, the image forming apparatus rotates the drive motor to prepare the heating roller 14 to increase the surface temperature to the standby temperature. Start rotation. Therefore, the photosensitive drum 2 starts rotating, and the winding member also starts rotating by receiving the drive from the photosensitive drum by the gear.

As the photosensitive drum rotates, the separating member 7
Is connected to the winding member 8, the photosensitive drum starts winding the separating member. The separation member gradually decreases its radius, and the separation distance between the photosensitive drum and the charging member also gradually decreases. Finally, during transport,
The separation member wound around the core metal of the charging member is wound around the winding member and collected, and the photosensitive drum 2 and the charging member 5 are pressed by the pressing device 52 at a predetermined pressure required for image formation. You. This is shown in FIG.

The time required during this time is much shorter than the time spent in the previous multiple revolutions.

Since the separating member 7 is wound around the winding member 8 and collected, the separating member does not need to be wound around the core of the charging member. If there is no scientific or mechanical adverse effect on the photosensitive drum and the charging member, the separation member may be wound around the photosensitive drum or the charging member during transport of the process cartridge.
It is possible to keep the charging member and the photosensitive drum apart. As shown in FIG. 7, in this case, there is no need to consider the image area.

One end of the separating member on the side of the charging member wound around the core metal is treated with an adhesive or the like so as to be wound around the photosensitive drum and collected. It is important that the adhesive and the like be made of a material that does not scientifically affect the photosensitive drum. For easier recovery, a configuration in which the entire area of the separation member is treated with an adhesive or the like, a guide is provided, or a member that appropriately presses the separation member wound around the photosensitive drum can be employed. It is also important that the photosensitive drum does not have a scientific influence on the photosensitive drum and that the photosensitive drum is electrically insulated.

As in the first embodiment, it goes without saying that the present invention can be applied to a brush-type charging member.

[0045]

As described above, according to the present invention, at least the image carrier,
In a process cartridge that has a charging member that contacts the image carrier and charges the image carrier, and is detachable from the image forming apparatus, the image carrier and the charging member are separated from each other by a separation member wound around the charging member. When the image carrier rotates, the separating member is wound around the image carrier, and the image carrier and the charging member come into contact with each other, so that the photosensitive drum and the charging member come into strong contact with each other due to an impact when the process cartridge is transported. However, there is no fear that the charging member and the photosensitive drum are rubbed at the time of conveyance, and that an image defect called a rubbing memory does not occur.

Further, as in the case where the charging member is separated from the photosensitive drum by using the spacer, forgetting to remove the spacer eliminates the risk of damaging not only the process cartridge but also the image forming apparatus main body. Furthermore, the usability can be remarkably improved without the photosensitive drum and the charging member being rubbed by the impact at the time of removing the spacer.

Further, among the means for performing the image forming step, a process cartridge which has at least an image carrier and a charging member which contacts the image carrier and charges the image carrier, and which is detachably attached to the image forming apparatus, The image carrier and the charging member are separated from each other by a separation member wound around the image carrier or the charging member.
The separation member is wound around the winding member, and the image carrier and the charging member come into contact with each other, so that there is no limitation on a portion around which the separation member is wound during the conveyance.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a main part of an image forming apparatus according to a first embodiment of the present invention.

FIG. 2 illustrates a main portion of a photosensitive drum of a process cartridge during conveyance according to the first exemplary embodiment.

FIG. 3 illustrates a main portion of a photosensitive drum of a process cartridge at the end of a pre-multiple rotation according to the first embodiment.

FIG. 4 is a configuration diagram using a guide and an auxiliary member.

FIG. 5 illustrates a main part of a process cartridge during conveyance according to the second embodiment.

FIG. 6 shows a main part of the process cartridge at the end of the previous multi-rotation in the second embodiment

FIG. 7 is a diagram illustrating a configuration in which a charging member or a photosensitive drum is wound around a charging member according to a second embodiment.

FIG. 8 is a configuration diagram of a main part of a conventional process cartridge.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cartridge container 2 Photoreceptor drum 3 Developing device 4 Cleaning device 5 Charging member 6 Spacer 7 Separating member 11 Image forming device 12 Host 13 Heat fixing device 14 Heating roller 15 Recording material storage section 16 Registration roller 17 Laser beam 18 Transfer means 31 Toner Container 32 Developing sleeve 33 Regulator blade 41 Cleaning container 42 Cleaning blade 51 Core bar 52 Pressurizing device 71 Guide 72 Auxiliary member

Claims (6)

[Claims] 1. A process cartridge that includes at least an image carrier and a charging member that contacts the image carrier and charges the image carrier, wherein the process cartridge is detachable from an image forming apparatus. The image carrier and the charging member are separated by a separating member wound around the charging member. When the image carrier rotates, the separating member is wound around the image carrier, and the image carrier and the charging member come into contact with each other. A process cartridge characterized by the above-mentioned. 2. A process cartridge having at least an image bearing member and a charging member for charging the image bearing member in contact with the image bearing member, wherein the process cartridge is detachable from the image forming apparatus. The image carrier and the charging member are separated by a separating member wound around the image carrier or the charging member, and with the rotation of the image carrier or the charging member,
A process cartridge wherein a take-up member for taking up the separation member rotates, the separation member is taken up by the take-up member, and the image carrier and the charging member come into contact with each other. 3. The process cartridge according to claim 2, wherein said separating member is a band-shaped member having a predetermined thickness and length. 4. The process cartridge according to claim 1, wherein said separation member is wound around a core of a charging member. 5. A process cartridge, wherein one end of the separation member is connected to a charging member or an image carrier. 6. A process cartridge, wherein one end of the separation member is connected to a winding member.