JPS61204669A - Image forming device - Google Patents

Abstract

PURPOSE:To eliminate the influence of foreign matter sticking on the surface of an image carrier by coating at least part of the image carrier surface with toner after one image forming operation is completed by an image forming device. CONSTITUTION:A photosensitive body is driven for a slight time after image formation is completed, and a primary electrostatic charger is turned on to charge a photoconductive layer while a transfer charger is held off and transfer materials are not fed. Further, a solenoid 13 is driven to rotate a cleaning device 9 counterclockwise through a level 12c and arms 12b and 12a against a spring 14. Therefore, toner sticks uniformly on the surface of the photosensitive body and is maintained until next image formation because a cleaning blade 10 does not operate because of the rotation of the cleaning device 9. Consequently, foreign matter produced in the device is hard to stick on the image carrier and even if it sticks, the foreign matter deforms in a high- humidity atmosphere and hardly exert an adverse influence upon the image formation, so images of invariably good quality are obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Object of the Invention (Field of Industrial Application) The present invention relates to an image forming apparatus using an electrostatic transfer process, such as an electrophotographic copying machine or a printer.

(Prior art and issues to be solved) A transferable toner image is formed on the surface of an image carrier that runs endlessly, and after being transferred to a transfer material, the transferred image is fixed. Image forming apparatuses configured to repeat the process of cleaning residual toner remaining on the image forming apparatus are well known.

In this type of image forming apparatus, corona products generated by the high pressure generating members present in the apparatus, and precipitates such as rosin and talc generated from transfer materials, mainly paper, firmly adhere to the surface of the image carrier. However, there is a risk that these materials will absorb moisture in a high humidity environment, lowering the resistance of the area and causing disturbances in the electrostatic latent image.

In order to avoid such drawbacks, it has already been proposed to take measures such as arranging a heater H at an appropriate location, such as near the image carrier, to heat it and remove moisture. Toner with a low melting point is used in developing devices, image carriers,
In order to electrostatically transfer the transfer material at will, it is undesirable to increase the viscosity due to heating, so the use of heaters has been limited.

In addition, a method has been proposed in which the above-mentioned foreign substances are removed by pressing and rubbing a silicone rubber roller or the like on the surface of the image carrier, but it is difficult to remove the foreign substances from selenium, zinc oxide, and amorphous silicon that form the photoconductive layer on the surface of the image carrier. , organic semiconductors, etc. may be locally abraded and damaged by this.
Furthermore, it is not always easy to rub with a uniform force over the entire width of the image carrier, and there is a risk that the life of the image carrier may be significantly reduced.

The present invention has been made to deal with such a situation, and it does not require heating the image carrier for a long period of time, and there is no risk of damaging the surface of the image carrier. It is an object of the present invention to provide an image forming apparatus that can prevent the influence of foreign substances.

(2) Structure of the invention (technical means for solving problems and their effects) In order to achieve the above object, in the present invention, in the image forming apparatus as described above, after one image forming operation is completed,
The toner is configured to apply toner to at least a portion of the surface of the image carrier.

By configuring in this way, foreign substances such as those mentioned above can be
To obtain an image forming apparatus which prevents the image forming apparatus from being affected by a high humidity environment while it is on standby, and which does not cause deterioration in image quality such as no image after the next operation.

(Description of Embodiments) The accompanying drawing is a side view of a main part schematically showing the structure of a photoconductor roller according to an embodiment in which the present invention is applied to a copying machine.

The surface photoconductive layer of the photoreceptor l rotating in the direction of the arrow is uniformly charged by the primary charger 2, and a predetermined optical image is projected onto it to form an electrostatic latent image. After toner is supplied to this latent image by a developing device 4 to form a transferable toner image, a transfer material (not shown) is supplied from a passage 5 to the surface of the photoreceptor at a transfer site equipped with a transfer charger 6. The toner image is transferred to a transfer material, separated from the photoreceptor by a separation charger 7, and then transported to a fixing site (not shown) by a transport means 8.

Residual toner remaining on the photoreceptor without being transferred to the transfer material at the transfer site reaches the cleaning device 9 as the photoreceptor rotates and is scraped off by the cleaning blade 1o.

The cleaning device 9 includes the cleaning blade 10
In addition, a cleaning roller 1 made of an elastic material such as Cricon rubber is provided on the upstream side of the photoreceptor when viewed in the direction of travel of the photoreceptor.
1 is arranged so as to press and rub against the photoreceptor. Furthermore, the cleaning device 9 is arranged to be able to swing freely around the rotating shaft 11a of the cleaning roller.

Also, an arm 12a is provided outside the housing of the cleaning device 9.
, 12b and a lever 12c are connected and arranged, and a solenoid 13 and a spring 14 are attached to the other end of the lever. Therefore, under normal conditions, the cleaning device 9 as a whole has the tendency to rotate counterclockwise in the drawing due to the action of the spring 14, and as a result, the cleaning blade 10 comes into pressure contact with the photoreceptor to perform the cleaning action.

After the primary charger 2 and other members for forming a series of images described above are activated and one or a series of image forming operations are completed, in the present invention, the photoconductor is driven for two or a few moments, and The primary charger is activated to charge the photoconductive layer, while the transfer charger, transfer material feeding, etc. remain inactive, and the solenoid 13 is energized and the spring 14
lever 12c, arm 12b, 12 against the action of
The cleaning device 9 is rotated in the counterclockwise direction shown in the drawing via a.

As a result, toner adheres uniformly to the surface of the photoreceptor, and this toner is maintained until the next image forming operation is performed since the cleaning grade 1° does not work due to the rotation of the cleaning device 9. In the present invention, it is preferable that the cleaning roller 11, which rubs the photoreceptor, rub the surface of the photoreceptor as lightly as possible so as not to remove more adhered toner than necessary.

Further, toner can be attached to the photoreceptor after the above-described image forming operation is completed during post-rotation in a known image forming apparatus.

After the toner has adhered to the entire surface of the photoconductor, the cleaning device 9 returns to the illustrated position by deenergizing the solenoid 13, and the cleaning blade 10 also returns to a position where it can scrape off the toner.

When the next image forming operation is started, the photoreceptor is rotated one or more revolutions to remove the attached toner, and then the normal copying operation is started.

In the above case, toner is attached to the entire surface of the photoreceptor, but since the foreign matter that adheres to the photoreceptor is often corona products, in the case of the device shown in the figure, a transfer charger is used.

It is also effective to simply attach toner only to the surface of the photoreceptor between the developing device and the cleaning device, centering on the separation charger.

The amount of toner deposited can be adjusted to a thickness suitable for the environment by changing the potential of the -order charger, changing the amount of exposure after charging, or by irradiating a dot pattern in the case of a laser printer.

Although the present invention has been described above as being applied to a copying machine, it goes without saying that the present invention can also be applied to other image forming apparatuses.

As explained above, in the present invention, after the image forming operation is completed, at least a portion of the surface of the image carrier is coated with toner, thereby preventing harmful effects on the image due to foreign matter adhering to the surface of the image carrier due to the environment. can do.

In addition, in the illustrated embodiment, a rubbing cleaning roller made of an elastic material is used as the cleaning device, but in this case as well, the pressing force on the image carrier can be made extremely weak, so that the surface of the image carrier due to strong vibrations can be reduced. Damage 1 Deterioration of image quality due to the occurrence of local grinding action can be prevented, and in some cases, it may not be necessary to provide a rubbing roller, or images of sufficient quality can be obtained by rubbing by a magnetic plan using a magnet roller.

Furthermore, even if the heater H is placed in the cage, it does not need to be energized all the time, which contributes to labor saving.

(3) As described in detail, according to the present invention, at least a portion of the surface of the image bearing member is covered with toner when the image forming apparatus is not in use, so that foreign matter generated within the apparatus is removed from the image. It does not easily adhere to the carrier, and even if it does, it is unlikely to be denatured in a high-humidity environment and have an adverse effect on image formation, which greatly contributes to always obtaining high-quality images.

[Brief explanation of drawings]

The accompanying drawing is a schematic side view of the main parts of an embodiment in which the present invention is applied to a copying machine.

Claims (2)

[Claims] (1) An image forming apparatus in which toner is uniformly applied to at least a portion of the surface of an image carrier after the image forming operation is completed. (2) Claim 1 that changes the thickness of the toner layer
The image forming apparatus described in .