JPH0736340A - Electrophotographic image forming device - Google Patents

Abstract

PURPOSE:To provide an electrophotographic image forming device having a cleaning device which is easy to assemble, requires no high precision for positioning, and prevents the scattering of toner at low cost. CONSTITUTION:In an electrophotographic image forming device provided with a cleaning device having a detachable toner case 1 for receiving a waste toner removed by sliding a cleaning blade 7 onto a photoreceptor 3 after transfer in which the photoreceptor 3 is subjected to charging and optical write to form an electrostatic latent image, a toner is adhered to the latent image to form a toner image, the toner image is transferred to a transfer sheet followed by fixing, and discharged, this device is provided with a toner scattering preventing shutter 2 rotatably supported to open and close a clearance 1a formed between the toner case 1 and the photoreceptor surface; and a toner scattering preventing film 4 which is pressed to the photoreceptor 3, when the toner scattering preventing shutter 2 is opened, to close the clearance 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic image forming apparatus such as a copying machine, a printer and a facsimile, and more particularly to an improvement of a cleaning apparatus used in the electrophotographic image forming apparatus.

[0002]

2. Description of the Related Art FIG. 3 is a schematic structural explanatory view of a conventional electrophotographic image forming apparatus, which comprises an optical system A, a writing section B, an image forming section C, a sheet feeding section D and the like. When an image formed by this image forming apparatus is transferred onto a transfer sheet to output an image, a charging device 107 charges a few hundred V on the photosensitive member 103 while the belt-shaped photosensitive member 103 circulates.
Alternatively, a charge of + several hundreds of V is added. After that, the latent image of the image is written on the photoconductor 103 by the optical writing device B using a laser beam, and is developed by the developing device 110. The transfer paper 111 is aligned with the development start position.
Is conveyed by the paper feed roller 113, and the intermediate roller 11
4, adjust the timing by the registration roller 115,
The image is transferred onto the transfer sheet 111 by the transfer device 112. The transferred transfer paper 111 is fixed by the fixing device 116, and is ejected to the outside of the device by the paper ejection roller 117. Toner and paper dust remaining on the photoconductor 103 after transfer
Cleaning blade 107 of the cleaning device 105
Then, the surface of the photoconductor is neutralized by the static eliminator 118. Subsequently, the surface of the photoconductor that has received the charge removal is charged by the charging device 108. Thereafter, by repeating this, image formation is sequentially performed.

FIG. 4 is an enlarged view showing the structure of a conventional cleaning device. The toner scraped off by the cleaning blade 107 of the cleaning device 105 is a fine powder and scatters in the air, so that the photoconductor 103 and the toner are scattered. It scatters from the gap 101a of the case 101 and stains the inside of the device.
Therefore, in order to prevent toner scattering in the above-mentioned apparatus, the shutter member 10 made of an elastic material of a toner scattering prevention film is provided in the gap 101a between the photoconductor 103 and the toner case 101.
2 is provided, and the scattering of toner is prevented by lightly abutting the tip of the shutter member 102 against the photoconductor 103. The scattering of the toner from both ends (both ends in the direction orthogonal to the paper surface) of the photoconductor 103 is prevented by sealing with a sealing material such as sponge.

However, when the shutter member 102 hits the photoconductor 103 with a strong force, the cleaning blade 10
Since the toner is scraped off at this portion prior to step 7, the toner may be scattered outside the cleaning device, or if the contact force is too weak, the tip of the shutter member may not contact the photoconductor 103. There was a problem. As a method for avoiding the above-mentioned inconvenience, a method of increasing the length of the shutter member 102 and decreasing the spring constant can be considered, but in this case, the mounting surface of the shutter member 102 becomes long and the toner case 1 is used.
01 becomes large in size. From the above circumstances, the length accuracy of the shutter member 102, the shutter member 1
Regarding the mounting accuracy of No. 02 and the positional accuracy between the photoconductor 103 and the toner case 101, a strict tolerance of about ± 0.2 mm to 0.5 mm is required, and a great amount of labor is required in manufacturing, resulting in a high cost. There was a problem.

[0005]

In the conventional cleaning device for the electrophotographic image forming apparatus, the processing accuracy of the peripheral member of the shutter member for preventing the scattering of toner is severe,
There was a problem that the cost became higher.

[0006]

SUMMARY OF THE INVENTION Therefore, the present invention is to solve such a problem. That is, it is an object of the present invention to provide an electrophotographic image forming apparatus having a cleaning device that is easy to assemble, does not require high positioning accuracy, is inexpensive, and prevents toner from scattering.

[0007]

In order to achieve the above object, the present invention forms an electrostatic latent image by charging and photowriting a photosensitive member, and attaches toner to the electrostatic latent image to form a toner image. A cleaning device having a removable toner case for accommodating the waste toner removed by transferring the toner image onto a transfer sheet, fixing the toner image, discharging the toner image, and slidingly contacting the cleaning blade onto the photosensitive member after the transfer. In the electrophotographic image forming apparatus, the toner scattering prevention shutter rotatably supported so as to open and close the gap formed between the toner case and the surface of the photoconductor, and the toner scattering prevention shutter is opened when the toner scattering prevention shutter is opened. The toner scattering prevention film has a cleaning device having a toner scattering prevention film that presses against the photoconductor to close the gap. At the time of the opening of over shatterproof shutter,
It is pressed against the photoconductor by the toner scattering prevention shutter, and the toner case has a dent shape at the portion where the tip of the toner scattering prevention film comes into contact when the toner scattering prevention shutter is closed. When the toner scattering prevention shutter is closed, the tip of the toner scattering prevention film is not in contact with the toner case, the toner scattering prevention film is made of a polyester film, the toner scattering prevention film, It is characterized in that it is made of silicone rubber, that the toner scattering prevention film is made of an elastomer, and that the toner scattering prevention film is made of a foam.

[0008]

According to the electrophotographic image forming apparatus configured as described above, when the toner scattering prevention shutter rotatably supported to open and close the gap between the toner case and the photoconductor is opened, An electrophotographic image with a cleaning device that prevents the toner from scattering by means of a toner scattering prevention film that is pressed against the photoconductor, is easy to assemble, does not require high positioning accuracy, and is inexpensive to prevent the toner from scattering. A forming device can be provided.

[0009]

Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 is a diagram showing a configuration of a cleaning device and its peripheral portion of the present invention. A charging device 8 and an optical writing device are provided for a belt-shaped photoconductor 3 which is stretched endlessly by a plurality of rollers R and circulates. 9, an electrostatic latent image is formed by charging and optical writing, and toner is applied to the electrostatic latent image by the developing device 10 to form a toner image, and the toner image is transferred to the transfer sheet 11. After being transferred by 12, the image is fixed by a fixing device (not shown) and discharged. The cleaning device 5 removes the residual toner on the photoconductor by sliding the tip of the cleaning blade 7 whose one end is supported by the casing C onto the photoconductor, and the removed waste toner is removed by a conveying means (not shown). Transported to Case 1 and stored (or transported further)
It is supposed to do. The cleaning device 5 including the toner case 1 and the like is detachable from the electrophotographic image forming apparatus.

The toner scattering prevention shutter 2 is rotatably supported by a casing C at a fulcrum 6, and is elastically biased by a not-shown elastic biasing means to close the gap 1a between the toner case 1 and the photosensitive member 3 (counterclockwise). Clockwise). The shutter 2 is a fan-shaped support member 2a.
And a shutter body 2b which is supported by the support member 2a and opens and closes the gap 1a. In addition, one end of the toner scattering prevention film 4 is supported on one end edge of the shutter 2, and the other free end of the film 4 is elastically pressed against the surface of the photoconductor.

The image forming apparatus main body and the cleaning device 5 attached to and detached from the main body of the image forming apparatus are linked with each other when the latter is mounted to open the shutter 2 (for example, a link mechanism).
A mechanism for engaging the protrusion provided on the main body side with the engaged portion provided on the shutter side to open the shutter is provided, and when the cleaning device is completely attached, the toner scattering prevention shutter 2 is The gap 1a is opened by the operation of the mechanism. On the other hand, when the cleaning device is detached, the toner scattering prevention shutter 2 is biased in the closing direction by the elastic biasing means and the gap 1 is removed.
Since a is closed, the toner is prevented from scattering outside when the cleaning device 5 is removed. When the cleaning device is attached, the toner scattering prevention shutter 2 is at the open position, and therefore the gap 1a of the toner case 1 is formed.
The toner scattering prevention film 4 urged in the closing direction is pressed against the surface of the photoconductor facing the gap 1a with a constant slight pressing force without any gap. This pressing force is a slight force that is insufficient to remove the toner on the photoconductor.

2 (a) and 2 (b) are enlarged views of the cleaning device and its main parts. When the shutter 2 is closed, the tip of the toner scattering prevention film 4 extending from the shutter 2 is placed in the toner case 1. In order to prevent the contact, the toner case 1 is provided with a recessed shape 1b. Therefore, it is possible to prevent the toner scattering prevention film 4 from coming into contact with the toner case 1 and deforming when the toner scattering prevention shutter 2 is closed. By using a polyester film as the toner scattering prevention film 4, it is possible to produce a film having a high rigidity and a strong resistance to deformation, a very thin thickness of about 0.05 mm to 0.1 mm, and a low spring constant. Therefore, it is convenient. Further, if silicon rubber is used as the toner scattering prevention film 4, the hardness thereof becomes extremely low,
There is no fear of scraping off the photoconductor 3, and since the photoconductor 3 has elasticity, the surface area to be adhered is increased, which is very convenient.
If an elastomer is used as the toner scattering prevention film 4, it is possible to exert an effective toner scattering prevention effect without leaking without causing harmful substances to adhere to the photoconductor or scraping the photoconductor, at a lower cost. You can Further, if a foam is used as the toner scattering prevention film 4, even if it is pressed against the photoconductor 3 with a slight force, the area of close contact is increased and the sealing property is improved, which is very convenient.

[0013]

As described above, according to the present invention, the toner scattering preventing shutter is rotatably arranged so as to open and close the gap formed between the toner case and the photoconductor, and the shutter is opened. Since the toner scattering prevention film that presses against the photoconductor prevents the toner from scattering, it is easy to assemble and does not require high positioning accuracy.
It is now possible to prevent toner from scattering at low cost.

[Brief description of drawings]

FIG. 1 is a side sectional view of a main part of an electrophotographic image forming apparatus showing an embodiment of the present invention.

FIGS. 2A and 2B are a side sectional view of an essential part and an enlarged side sectional view of an essential part of an electrophotographic image forming apparatus showing another embodiment of the present invention.

FIG. 3 is a side sectional view illustrating an outline of a conventional electrophotographic image forming apparatus.

FIG. 4 is a side sectional view for explaining a main part of a conventional electrophotographic image forming apparatus.

[Explanation of symbols]

1 ... Toner case, 1a ... Gap, 1b ... Dimple shape, 2 ... Toner scattering prevention shutter, 3 ...
Photoreceptor, 4 ... Toner scattering prevention film, 5 ... Cleaning device, 6 ... Support point, 7 ... Cleaning blade, 8 ... Charging device, 9 ... Optical writing device, 10 ...・ Developing device, 11 ・ ・ ・ Transfer paper, 12 ・
..Transfer device 101 ... Toner case, 101a ...
-Gap, 102 ... Shutter member, 103 ... Photoconductor, 5 ... Cleaning device, 107 ... Cleaning blade, 108 ... Charging device, 109 ...
Optical writing device, 110 ... Developing device, 111 ...
Transfer paper, 112 ... Transfer device, 113 ... Paper feed roller, 114 ... Intermediate roller, 115 ... Registration roller, 116 ... Fixing device, 117 ... Discharge roller, 118 ... Static eliminator.

Claims (7)

[Claims] 1. An electrostatic latent image is formed by charging and optical writing on a photosensitive member, toner is attached to this to form a toner image, and the toner image is transferred onto a transfer sheet, fixed, and then discharged. In an electrophotographic image forming apparatus including a cleaning device having a removable toner case for containing waste toner removed by sliding a cleaning blade onto the photoreceptor after transfer, the toner case and the photoreceptor surface are A toner scattering prevention shutter that is rotatably supported so as to open and close a gap formed between the toner scattering prevention film and a toner scattering prevention film that presses the photoconductor when the toner scattering prevention shutter is opened to close the gap. An electrophotographic image forming apparatus comprising a cleaning device having the same. 2. The electrophotographic image forming apparatus according to claim 1, wherein the toner scattering prevention film is pressed against the photoconductor by the toner scattering prevention shutter when the toner scattering prevention shutter is opened. 3. The toner case has a recessed portion where the leading end of the toner scattering prevention film comes into contact when the toner scattering prevention shutter is closed.
3. The electrophotographic image forming apparatus according to claim 1, wherein the front end portion of the toner scattering prevention film is not in contact with the toner case when the toner scattering prevention shutter is closed. 4. The toner scattering prevention film is composed of a polyester film.
The electrophotographic image forming apparatus according to any one of items 1 to 3. 5. The electrophotographic image forming apparatus according to claim 1, wherein the toner scattering prevention film is made of silicone rubber. 6. The electrophotographic image forming apparatus according to claim 1, wherein the toner scattering prevention film is made of an elastomer. 7. The electrophotographic image forming apparatus according to claim 1, wherein the toner scattering prevention film is made of foam.