JPH063878A - Electrophotographic device - Google Patents

Abstract

PURPOSE:To always obtain an excellent image by surely periodically clean a photosensor detecting toner density on a photosensitive body. CONSTITUTION:A process cartridge 16 is constituted by unitizing a photosensitive body 11, an electrostatic charger 12, a developing device 13, and a cleaning device 15, and it is freely loaded in and unloaded from a device main body 10. Meanwhile, the photosensor 21 detecting the toner density on the photosensitive body 11 is attached to the device main body 10. A cleaning member 27 is attached to the surface of the casing 16a of the process cartridge 16 on the photosensor 21 side. Then, the photosensor 21 is cleaned by bringing the cleaning member 27 into contact with the photosensor 21 at the time of loading/unloading the process cartridge 16.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic system (a system for transferring an image formed on a photoconductor to a sheet for recording) using a laser, such as a printer, a copying machine and a facsimile. The present invention relates to an electrophotographic apparatus that records on a sheet.

[0002]

2. Description of the Related Art Conventionally, for example, in a laser printer, an electrophotographic process means such as a charging device, a developing device and a transfer device is arranged around a photoconductor, and the photoconductor and some of the electrophotographic process means are arranged. The process cartridge is constructed as a unit, and the process cartridge is detachably attached to the apparatus main body.

On the other hand, a photosensor for detecting the toner density adhering to the photoconductor at the time of development is provided, and the photosensor detects the toner density on the photoconductor, and the detection result is sent to a controller or the like by a signal. The feed toner concentration is kept constant.

[0004]

However, when the toner is adhered to the photoconductor by the developing device, the toner may scatter and the photosensor may become dirty. This stain needs to be cleaned regularly in order to obtain a good image, and there is no problem with a laser printer that is serviced by a serviceman because it is cleaned regularly and surely. A laser printer based on the maintenance has a problem that an unfamiliar user may leave unwiping or forget to perform maintenance, so that a good image cannot be obtained.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to ensure that a photo sensor is regularly cleaned so that a good image can always be obtained.

[0006]

Therefore, in the electrophotographic apparatus according to the first aspect of the present invention, the electrophotographic process means is arranged around the photoconductor 11 as in the embodiments shown in FIGS. 1 to 3 below. The photoconductor 11 and some of the electrophotographic process means are unitized to form a process cartridge 16, and the process cartridge 16 can be attached to and detached from the apparatus main body 10 while the photoconductor 11 is formed.
In an electrophotographic apparatus including a photo sensor 21 for detecting the toner density, a cleaning member 27 that contacts the photo sensor 21 when the process cartridge 16 is attached or detached and cleans the photo sensor 21 is provided.
6 is provided.

According to a second aspect of the present invention, as in the embodiments shown in FIGS. 4 to 6 below, for example, an image formed on the photoconductor 11 by using the electrophotographic process means is formed into a sheet. After being transferred to the fixing roller 22, the sheet is transferred to a fixing member such as the fixing roller 23 and the pressure roller 2.
4. The electrophotographic apparatus according to claim 1, wherein the transfer image on the sheet is fixed through a pressure member such as No. 4, the cleaning member 27 when the process cartridge 16 is attached to the apparatus main body 10. Is pressed against the peripheral surface of the fixing member.

[0008]

When the process cartridge 16 is attached to or detached from the apparatus main body 10, the cleaning member 27 is brought into contact with the photosensor 21 to clean it.

According to the second aspect of the present invention, when the process cartridge 16 is attached to the apparatus main body 10,
The cleaning member 27 is pressed against the peripheral surface of the fixing member of the fixing device 22 to clean it.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic diagram of the entire configuration showing the internal mechanism of a laser printer according to an embodiment of the present invention. Reference numeral 10 in the figure denotes the apparatus main body. A photoconductor 11 is provided substantially in the center of the apparatus body 10. Around the photoconductor 11, a charger 1 is provided below the photoconductor 11.
2 in the order of the driving direction shown by the arrow in the drawing below,
3, the transfer device 14 and the cleaning device 15 are arranged.

The charging device 12, the developing device 13 and the cleaning device 15 together with the photosensitive member 11 are constructed as one unit and are detachably attached to the apparatus main body 10 as a process cartridge 16. An optical writer 17 is arranged on the lower side of the apparatus, and a sheet feeding cassette 18 accommodating sheets is detachably attached to the lower portion of the apparatus main body.

Then, the sheet sent out from the sheet feeding cassette 18 in the direction of arrow A by the sheet feeding roller 19 is conveyed to the upper side of the photoconductor 11 by the registration roller pair 20 at a timing. The photoconductor 11 is driven in the counterclockwise direction indicated by the arrow, and at that time, the surface of the photoconductor 11 is uniformly charged by the charger 12, and the laser beam from the optical writer 17 is irradiated onto the photoconductor 11. An electrostatic latent image is formed on. This latent image is visualized by toner when passing through the position of the developing device 13.
The toner density of the visible image is detected by a photo sensor 21 provided at a position facing the surface of the photoconductor 11.

This visible image is transferred by the transfer device 14 to the lower surface of the sheet conveyed to the upper side of the photoconductor 11. Then, the sheet after the image transfer is sent to the fixing device 22, and the transferred image on the sheet is fixed through a space between the fixing roller 23 and the pressure roller 24 of the fixing device 22. Then, the sheet exiting the fixing device 22 is further conveyed by the paper discharge rollers 25 and discharged onto the paper discharge tray 26. On the other hand, the residual toner on the photoconductor 11 after the transfer of the visible image is removed by the cleaning device 15.

By the way, the photo sensor 2 is attached to the apparatus main body 10.
1 is set. On the other hand, on the casing 16a of the process cartridge 16, a pad-like cleaning member 27 made of urethane foam is attached to the surface on the photosensor 21 side.

Then, in order to replace the process cartridge 16, as shown in FIG. 2, the upper cover of the apparatus main body 10 is replaced.
When opening and detaching 10a, the cleaning member 27 is brought into contact with the photo sensor 21 to clean the photo sensor 21, as shown in FIG.

In the above-mentioned embodiment, the cleaning member 27 is directly attached to the casing 16a to clean only the photosensor 21, but the cleaning member is also attached when the process cartridge 16 is attached. Alternatively, 27 may be pressed against the peripheral surface of the fixing roller 23.

That is, as shown in FIG. 4, a support base 28 made of a member having substantially the same width as the width of the process cartridge 16 and a substantially U-shaped cross section is provided with a support shaft 29 at one side end thereof. The casing 16a is rotatably attached, and the other side end is bent outward at a right angle to form an engaging edge 28a, as shown in FIG.

Further, an engaging portion 16c having a tip bent at a right angle to the support base 28 side is provided on the upper surface of the casing 16a, and an engaging edge 2 is formed.
Projected parallel to 8a. The engaging portion 16c is connected to the engaging edge 28.
The range in which the support base 28 engages with a and rotates outward about the support shaft 29 is limited. Support base 28 and casing 16
A biasing spring 30 is provided between the outer surface of a and the support base 28.
Is urged toward the outside. The cleaning member 27 is attached to the protruding outer center surface of the support base 28 in the lengthwise direction.

When the process cartridge 16 is attached, the cleaning member 27 is brought into contact with the photo sensor 21 to clean it in the process. Also, when the process cartridge 16 is completely attached,
As shown in FIG. 6, the cleaning member 27 is pressed against the peripheral surface of the fixing roller 23. At this time, the support base 28 is rotated outward by the urging force of the urging spring 30, and the cleaning member 27 is urged to the fixing roller 23 within the range of engagement between the engaging portion 16c and the engaging edge 28a. Clean it by pushing it spontaneously.

[0020]

Therefore, according to the first aspect of the present invention, when the process cartridge is attached to or detached from the apparatus main body,
Since the cleaning member is brought into contact with the photo sensor to clean it, the cleaning of the photo sensor is regularly and reliably performed along with the replacement of the process cartridge, and a good image is always obtained.

Further, according to the second aspect of the present invention, since the cleaning member is pressed against the peripheral surface of the fixing member of the fixing device when the process cartridge is attached to the main body of the apparatus, the surface of the fixing member. Clean the toner attached to the. Further, the cleaning member is also replaced with the replacement of the process cartridge, so that the fixing performance of the fixing device can be prevented from being deteriorated. Further, since the cleaning member for the photo sensor and the cleaning member for the fixing member are combined into one cleaning member, the cost can be reduced.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a laser printer which is an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a replacement state of the process cartridge.

FIG. 3 is a partially enlarged view showing a contact state between the photo sensor and the cleaning member.

FIG. 4 is a perspective view showing an appearance of a process cartridge according to another embodiment of the present invention.

FIG. 5 is a partially enlarged view showing a contact state between the fixing roller and the cleaning member.

FIG. 6 is an overall schematic configuration diagram of a laser printer showing a mounting state of the process cartridge.

[Explanation of symbols]

 10 Device Main Body 11 Photoreceptor 16 Process Cartridge 21 Photo Sensor 22 Fixer 23 Fixing Roller (Fixing Member) 24 Pressure Roller (Pressurizing Member) 27 Cleaning Member

Claims (2)

[Claims] 1. A process cartridge is constructed by arranging an electrophotographic process means around a photoconductor to unitize the photoconductor and some of the electrophotographic process means, and the process cartridge is formed. An electrophotographic apparatus having a photosensor for detecting the toner density on the photoconductor while being detachable, a cleaning member for contacting and cleaning the photosensor when the process cartridge is attached or detached. The process card
An electrophotographic device provided in the ridge. 2. An image formed on the photoconductor by using the electrophotographic process means is transferred to a sheet, and the sheet is passed between a fixing member and a pressing member of a fixing device. The electrophotographic apparatus according to claim 1, wherein the transferred image on the printer is fixed, wherein the cleaning member is pressed against the peripheral surface of the fixing member when the process cartridge is attached to the apparatus main body. apparatus.