JP2523392B2 - Process cartridge and image forming apparatus - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a copying machine or a laser beam printer that employs an electrophotographic method, and a process cartridge that is attached to and detached from an image forming apparatus main body.

(Prior Art) There is known a process cartridge which integrally has a cleaning device and a charging device in addition to a photosensitive drum which is an image bearing member, and which is detachably arranged in a main body of an image forming apparatus.
The process cartridge is intended to facilitate maintenance by replacing the entire process cartridge when the photosensitive drum reaches the end of its life or the cleaning device is full of waste toner.

By the way, as a means for notifying the replacement time of the process cartridge, a counter for calculating the number of times of image formation by the photosensitive drum or the like is provided in the main body of the apparatus, and the process cartridge is replaced when the number by the counter becomes a predetermined value or more. Known devices are also known.

In the case of the above apparatus, after the worker or the like replaces the process cartridge, the counter is reset to zero (0),
The next replacement time of this process cartridge is calculated.

(Problem to be Solved by the Invention) However, since the operator resets the counter manually, there is a disadvantage that the operator accidentally resets the counter.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a process cartridge and an image forming apparatus in which the replacement time of the process cartridge can be surely grasped by a counter.

(Means for Solving the Problems) To achieve the above object, the present invention provides a frame, an image carrier, and a process unit acting on the image carrier in a process cartridge detachable from the image forming apparatus main body. A protective cover removably provided on the frame for protecting the image carrier, and a release means for removing the protective cover from the frame by abutting on a contact portion provided on the main body of the image forming apparatus. Reset means for resetting a counter for counting the number of times of image formation provided on the main body of the image forming apparatus, the reset means being provided on the protective cover.

Further, according to the present invention, a process cartridge is attachable / detachable, and in an image forming apparatus for forming an image on a recording medium, a counter for counting the number of times of image formation and a process for notifying the replacement time of the process cartridge, When the cartridge is mounted on the main body of the apparatus, it acts on the releasing means provided on the protective cover to remove the protective cover from the frame, the frame, the image carrier, and the image carrier. Process means, a protective cover detachably provided on the frame for protecting the image carrier, and an abutting portion provided on the main body of the image forming apparatus so that the protective cover is removed from the frame. Release means for removing and provided on the protective cover,
Mounting means for mounting a process cartridge having reset means for resetting a counter for counting the number of times of image formation provided in the main body of the image forming apparatus,
It is characterized by having.

(Example) Below, the Example of this invention is described based on an accompanying drawing.

In the embodiments described below, the process cartridge in which the exposed portion of the image bearing member from the cartridge container is covered with the protective cover is detachably disposed in the apparatus main body, and the process cartridge replacement timing is set. An image forming apparatus having a counter for notifying the number of times of image formation to be notified, wherein the protective cover is provided with reset means for resetting the counter in association with mounting of a process cartridge to the apparatus main body, and the process is provided on the apparatus main body side. There is provided a releasing means for releasing the engagement between the cartridge container and the protective cover in association with the mounting of the cartridge in the main body of the apparatus and for making the protective cover removable from the main body of the apparatus.

Thus, according to the embodiment described below, the replacement time of the process cartridge can be determined by the counter for calculating the number of times the image is formed. Since it can be reset only by the reset means provided in the protective cover for the image carrier,
The counter is not accidentally reset by an operator or the like, and the counter is reliably reset when the process cartridge is attached to the apparatus main body, that is, when the process cartridge is replaced.

Further, when the process cartridge is mounted in the apparatus main body, the protective cover can be removed to the outside of the apparatus main body through the releasing means on the apparatus main body side. The reset state can be released, and the image forming work can be performed thereafter.

 Now, an outline of the image forming apparatus will be described with reference to FIG.

In the figure, 10 is a photosensitive drum that is an image bearing member, and around the photosensitive drum 10, a cleaning device 11, a charging device 12, and a developing device.
13, an image forming unit such as a transfer charger 14 and a transfer unit are provided.

Then, on the paper feed side of the photosensitive drum 10, a paper feed cassette 15, a paper feed roller 16, a registration roller 17, etc. are arranged,
A transport unit 18, a fixing device 19, a paper discharge roller 20, a paper discharge tray 21 and the like are arranged on the paper discharge side. Further, above the photosensitive drum 10, a lamp 22, mirrors 23, 24, 25, 26, 27, 28, an imaging lens 2
A document scanning unit composed of 9 or the like is provided, and the document Q positioned by the document pressing plate 31 on the transparent document table 30 is moved by the lamp 22, the mirrors 23, 24 and 25 in the direction of the arrow in the figure. Q
To scan the image light L reflected from the document Q on the photosensitive drum 10.
I'm trying to expose it towards.

Thus, the photosensitive drum uniformly charged by the charger 12.
When the image light L from the document scanning unit is exposed to 10,
An electrostatic latent image is formed on the photosensitive drum 10. Then, the electrostatic latent image is developed by the developing device 13 as the photosensitive drum 10 rotates.
And is visualized as a toner image by the developing device 13. Thereafter, the toner image is directed toward the transfer charger 14 as the photosensitive drum 10 rotates, and is transferred onto the transfer paper P by the transfer charger 14.

On the other hand, the transfer paper P in the paper feed cassette 15 is taken out one by one by the paper feed roller 16 and sent to the registration roller 17, and the timing is matched by the registration roller 17 and sent to the photosensitive drum 10. To be Then, when the toner image on the photosensitive drum 10 is transferred onto the transfer paper P via the transfer charger 14, the toner image is fixed by the fixing device 19, and the transfer paper P after the fixing operation is discharged. It is stacked on a paper discharge tray 21 via a paper roller 20.

By the way, photosensitive drum 10, cleaning device 11, charging device
The process cartridge 12 is integrally assembled in a cartridge container 41 to form a process cartridge 40, and the process cartridge 40 is arranged in the apparatus main body 1 in an easily attachable and detachable manner. This process cartridge 40 is used when the photosensitive drum 10 reaches the end of its life or the cleaning device 11 is full of waste toner.
This is intended to facilitate maintenance by replacing the entire 40.

Here, a part of the photosensitive drum 10 in the process cartridge 40 is exposed to the outside from the cartridge container 41 for transferring the toner image, but when the process cartridge 40 is outside the apparatus main body 1, this photosensitive drum 10 10 exposed parts are first
As shown in the figure, it is covered with a drum cover 50 so as to be protected from external light and foreign matter. Therefore, the drum cover 50 becomes unnecessary when the process cartridge 40 is mounted in the apparatus main body 1, and needs to be moved to another place or removed to the outside.

In the process cartridge 40, the drum cover 50 is removed to the outside when the process cartridge 40 is mounted in the apparatus main body 1. Less than,
The details around the drum cover 50 of the process cartridge 40 will be described with reference to FIG.

The drum cover 50 has a J-shaped cross section, which is composed of a lower curved portion 50a and an upper linear portion 50b. The curved portion 50a covers the exposed outer surface along the photosensitive drum 10 and is linear. The portion 50b extends to the upper wall 41a of the cartridge container 41 and covers one side surface of the process cartridge 40.

The front portion of the linear portion 50b of the drum cover 50 is provided with a first protrusion 51 facing forward, and the first protrusion 51 is fitted into the first hole portion 42 provided in the front side wall 41b of the cartridge container 41. In addition, the second protrusion 52 is provided at the rear end of the curved portion 50b so as to be curved in a U shape and protrude in the same direction as the first protrusion 51. The second protrusion 52 is a cartridge. Rear side wall 41c of container 41
It is fitted in the second hole portion 43 provided in the.

Further, a claw portion 53 projects forward from the front end portion of the curved portion 51a of the drum cover 50, and the claw portion 53 and a plate-shaped projection portion 44 provided below the front side wall 41b of the cartridge container 41 are engaged. I am fit. Reference numeral 54 is a handle for pulling out the drum cover 50.

Therefore, in order to attach the drum cover 50 to the cartridge container 41, the drum cover 50 is attached to the cartridge container 41.
When this is slid forward along the side wall of the drum cover 50, the first and second protrusions 51 and 52 of the drum cover 50 and the front and rear side walls 41b and 41c of the cartridge container 41 are removed. Hole 4
2,43 and fit. In this case, since the claw 53 that obliquely protrudes upward bends the lower end side of the protrusion 44 of the cartridge container 41 forward, the claw portion 53 protrudes to the front side of the protrusion 44 and the claw portion 53. The engagement of the protrusion 44 ends. In this state, the drum cover 50 is in a state in which it cannot be pulled out rearward, and thus is fixed to the cartridge container 41.

On the other hand, in front of the mounting portion of the process cartridge 40 on the apparatus main body 1 side, as shown in FIG. 3, a main body protrusion 60 that engages with the claw portion 53 of the drum cover 50 and pushes the claw portion 53 downward.
As shown in FIG. 4, when the process cartridge 40 is inserted from the front side wall 41b side of the cartridge container 41 into the inside of the apparatus main body 1, the main body protrusion 60 and the claw of the drum cover 50 are inserted. Since the claw portion 53 is pushed downward, the claw portion 53 is disengaged from the protrusion 44 of the cartridge container 41, and the drum cover 50 is pulled out to the rear side of the apparatus main body 1. It will be possible.

By the way, after installing a new process cartridge 40 in the apparatus main body 1 and using it,
In order to know the replacement time of 40, a counter 61 for counting the number of times of image formation by the photosensitive drum 10 etc. is attached to the apparatus main body 1 side, and when the number by the counter 61 reaches a predetermined value. The process cartridge 40 is replaced. If the process cartridge 40 is replaced with a new one, this counter 61
Is reset to zero (0) to inform the next replacement time.

As shown in FIG. 3, the counter 61 is attached to one side of the main body wall 1a above the mounting portion of the process cartridge 40 of the apparatus main body 1, and the reset button 61a is attached to the main body wall 1a.
It is exposed to the outside from the hole 62 of a.

When the process cartridge 40 is mounted in the apparatus main body 1, the reset button 61 of the counter 61 is provided on the upper portion of the process cartridge 40 on the rear side of the drum cover 50.
Reset protrusion 5 that can reset the counter 61 by pressing a
Five are provided.

When the replacement time of the process cartridge 40 is recognized from the value of the counter 61, the process cartridge 40 in use is pulled out from the apparatus main body 1 and then a new process cartridge 40 is inserted into the apparatus main body 1. in this case,
The reset protrusion 55 of the drum cover 50 is the hole 62 of the apparatus main body 1.
, And the reset button 61a of the counter 61 is pressed, the value of the counter 61 is reset to zero (0).

Moreover, in this case, the claw portion 53 of the drum cover 50 is not
Since it engages with the main body projection 60 on the side, the engagement between the claw portion 53 and the projection portion 44 of the cartridge container 41 is released, and the drum cover
50 can be pulled out. Therefore, the process cartridge 40 is completely replaced by pulling the drum cover 50 outward. When the drum cover 50 is still attached to the process cartridge 40, the apparatus main body 1
The image forming work cannot be performed because the guide plate for conveying the transfer paper P arranged near the photosensitive drum 10 on the side is not properly positioned.

As described above, the apparatus main body 1 of the process cartridge 40
The counter protrusion 61 is reset by the reset protrusion 55 of the drum cover 50 according to the mounting on the counter.
61 will be reliably reset according to the installation of a new process cartridge 40, and with this counter 61,
Therefore, it is possible to surely grasp the replacement time of the next process cartridge 40.

Further, since the counter 61 is reset only by the reset protrusion 55 of the drum cover 50, if the drum cover 50 is pulled out from the process cartridge 40 in the apparatus main body 1, the counter 61 can no longer be reset. It also eliminates the inconvenience of resetting the counter.

As described above, according to this embodiment, since the counter for notifying the replacement time of the process cartridge can be reset only by the reset means provided in the image carrier protective cover of the process cartridge,
The counter is reliably reset when the process cartridge is attached to the apparatus main body.

Further, since the protective cover is detached to the outside when the process cartridge is mounted in the main body of the apparatus, the reset state of the counter is released by this, and the replacement time of the next process cartridge can be surely grasped. Like Then, by removing the protective cover, the counter will not be reset by a malfunction thereafter.

(Effects of the Invention) As described above, according to the present invention, it is possible to obtain the effect that the replacement time of the process cartridge can be surely grasped by the counter.

[Brief description of drawings]

FIG. 1 is a sectional view of the process cartridge, FIG. 2 is a perspective view of the process cartridge, and FIG. 3 is a view showing a state in which the process cartridge is being inserted into the apparatus main body.
FIG. 5 is a diagram showing a state in which the process cartridge is completely mounted in the apparatus main body, and FIG. 5 is a side sectional view of the image forming apparatus. 1 ... Device body, 10 ... Photosensitive drum (image carrier), 40 ...
… Process cartridge, 41 …… Cartridge container, 55
...... Reset protrusion (reset means), 60 …… Main body protrusion (release means), 61 …… Counter.

Claims (2)

(57) [Claims] 1. A process cartridge attachable to and detachable from an image forming apparatus main body, comprising a frame, an image carrier, process means acting on the image carrier, and removable to the frame to protect the image carrier. And a release means for removing the protective cover from the frame by abutting on a protective cover provided on the image forming apparatus main body, and an abutment portion provided on the image forming apparatus main body, and an image forming apparatus main body provided on the protective cover. And a reset means for resetting a counter for counting the number of times the image is formed. 2. An image forming apparatus in which a process cartridge is attachable / detachable and forms an image on a recording medium, a.
A counter for counting the number of times of image formation, b. An abutting portion for abutting against a releasing means provided on the protective cover to remove the protective cover from the frame when the process cartridge is mounted on the apparatus main body, c. a frame, an image bearing member, a process unit acting on the image bearing member, a protective cover detachably provided on the frame to protect the image bearing member, and an image forming apparatus main body. And a resetting means for contacting the contact portion to remove the protective cover from the frame, and resetting a counter provided on the protective cover for counting the number of image formations provided on the main body of the image forming apparatus. An image forming apparatus comprising: a mounting means for mounting a process cartridge having: