JPH08202230A - Image forming device - Google Patents

Abstract

(57) [Abstract] [Purpose] To pass through the cleaning device after transfer to effectively remove the residual developer adhering to the image bearing member to prevent deterioration of image quality. An image carrier (1), a charging member (2) which contacts the image carrier and charges the image carrier, and a latent image formed on the image carrier by an exposure device is developed. A developing device (3), a transfer device (4) for transferring the developed image to a transfer sheet, and a cleaning device for removing and collecting residual toner on the image carrier after transfer by a blade-shaped cleaning member. In the image forming apparatus having (5), a second cleaning member (7) capable of coming into contact with and separating from the image carrier is provided between the cleaning device and the charging member, and the cleaning member is used as the image carrier when necessary. By contacting the cleaning device, the dirt adhering to the image bearing member is cleaned and removed to prevent the dirt from adhering to the charging member.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus using an electrophotographic system or the like, and relates to a charging member that contacts an image carrier to be charged and a residual developer on the image carrier that contacts the image carrier. The present invention relates to an image forming apparatus having a blade-shaped cleaning member to be removed.

[0002]

2. Description of the Related Art Conventionally, as a charging device used for charging before image exposure in a copying machine or the like, a device using corona discharge development has been generally used, but recently, a conductive charging member has been used as a photosensitive member. A contact charging method in which a charging voltage is applied directly to the charging member is also used. The contact charging method has been put into practical use because it generates much less ozone than the corona charging method. For example, in a configuration in which a conductive rubber roller is brought into contact with a photoconductor and is driven to rotate together with the rotation of the photoconductor, the photoconductor is uniformly charged by applying a voltage to a cored bar that serves as a shaft of the rubber roller.

On the other hand, as a means for cleaning the residual developer on the image carrier after the image formed on the image carrier is transferred to the transfer paper by the transfer device, a web made of fine fibers is used as the image carrier. There are a web method for contacting and wiping off the developer adhering to the image carrier, and a blade method for scraping the developer on the image carrier by pressing a rubber material blade onto the image carrier and then collecting by a collecting means. is there. However, in the web method, it is necessary to constantly bring a new surface into contact with the image carrier, and the web becomes a consumable item.
The blade method is generally used because of the large space.

[0004]

In the image forming apparatus using the above cleaning blade, the residual toner scraped off by the blade, the shavings of the image carrier, or the like scrapes off the blade, and the image carrier is removed. However, this phenomenon tends to occur when the elapsed time from the previous copy is long. In an image forming apparatus using the contact charging method, stains attached to the image carrier adhere to the charging member as well, causing a charging failure at the stain-attached portion, which appears as stains on the image.

An object of a first invention according to this application is to solve the above problems and prevent image deterioration of the image carrier while effectively removing contamination on the image carrier. To provide a device.

An object of a second invention according to this application is to provide an image forming apparatus capable of suppressing deterioration of an image carrier.

A third object of the present invention is to provide an image forming apparatus capable of effectively removing the deposits on the image carrier.

[0008]

In order to achieve the above object, the first invention of this application is to provide an image carrier and a charging device for contacting the image carrier and charging the image carrier. A member, a developing device for developing a latent image formed on the image carrier by an exposure device, a transfer device for transferring the developed image to a transfer paper, and a residue on the image carrier after transfer. In an image forming apparatus having a cleaning device that removes and collects toner by a blade-shaped cleaning member, a second cleaning member that can be brought into contact with and separated from an image carrier is provided between the cleaning device and the charging member. In order to prevent deterioration of the image bearing member, the second cleaning member can be brought into contact with and separated from the image bearing member, and if necessary, brought into contact with the image bearing member so that the cleaning blade slips through the image bearing member. Clean and remove the dirt adhering to the Prevent adhesion to members in advance, thereby preventing from appearing to copy image.

The second invention is characterized in that the second cleaning member comes into contact with the image carrier when the image forming apparatus is started up, whereby deterioration of the image carrier is further prevented.

The third aspect of the invention is characterized in that the second cleaning member is in the form of a pad or a brush, whereby the dirt adhering to the image carrier can be more effectively removed.

[0011]

【Example】

(First Embodiment) One embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic side view of an image forming apparatus including a second cleaning member that can be brought into contact with and separated from an image carrier, which is an embodiment of the present invention.

In FIG. 1, reference numeral 1 is a photoconductor as an image bearing member, and a main motor (not shown) is rotated by a start signal, and the photoconductor 1 is connected to and driven by the motor.
Rotates. Further, the charging roller 2 as a charging member, which is pressed against the photoconductor, rotates following the photoconductor 1.
In the charging step, an applied voltage is applied from the charging roller 2 to charge the charging roller 2 to a predetermined potential. An electrostatic image, that is, a latent image is formed on the charged photoconductor 1 by an exposure device (not shown), and the latent image is toner-developed into a developed image by the developing device 3, and the developed image is transferred to the transfer paper P. The toner remaining on the photosensitive member is transferred by the device 4, and then the cleaning blade 6 installed in the cleaning device 5 removes the residual toner. In the present invention, the cleaning blade 6 is brought into contact with the rotation direction of the photoconductor 1 in the counter direction to scrape off the residual toner on the photoconductor 1.

Reference numeral 7 denotes a second cleaning member which is configured to be pressed against the photoconductor 1 so as to be able to come into contact with and separate from the photoconductor 1. FIG. 2 shows the cleaning state of the cleaning member. The cleaning member 7 is pressed against the photoconductor 1 only during cleaning by the actuating means such as the solenoid 8, and at other times, the cleaning member 7 is removed from the photoconductor 1. Let go. The reason why the second cleaning member is brought into contact with the photoconductor only during cleaning is to prevent deterioration of the photoconductor. In this embodiment,
The timing at which the cleaning member 7 is pressed against the photoconductor 1 is the same as the start of rotation of the photoconductor when the image forming apparatus is started, and the pressing time is one rotation of the photoconductor. . With this configuration, the photoconductor was hardly scraped or deteriorated by the second cleaning member.

(Second Embodiment) In the first embodiment, the second cleaning member is pressed against the photoconductor when the image forming apparatus is activated, but the image formation has a longer photoconductor life. In the device, it is better to reduce the number of cleanings. It has been known that slipping of the cleaning blade is likely to occur when two hours or more have passed from the previous time until the image is taken again. This makes it possible to reduce the number of cleanings without having to clean each time at startup.

For example, in an apparatus in which the number of sheets used per day is relatively large, it is assumed that the apparatus is used at an appropriate frequency when the apparatus is on, and when the apparatus is turned off and then turned on again. The cleaning member is in contact with the photoconductor. Also, it is known that the cleaning blade does not slip through if the image is taken within 2 hours from the last time, so that the cleaning member is automatically brought into contact with the photoconductor every 2 hours. . Further, it is possible to detect the time from the previous use to the next use and to make the cleaning member contact the photoconductor when two hours or more have elapsed. Further, the cleaning member may be manually brought into and out of contact with the photoconductor, and the user may perform cleaning as necessary. If it can be cleaned manually, it is effective against accidental stains.

In the above embodiments, the time for which the second cleaning member is pressed against the photoconductor is one revolution of the photoconductor, but it can be appropriately increased or decreased.

In the above embodiment, a pad-like material is used as the second cleaning member. The pad-shaped cleaning member
Since the stains on the photoconductor were completely wiped off and removed, the stains did not adhere to the charging member, and good results were obtained.
In addition to the pad-like shape, a brush-like cleaning member was used. With a brush-like object, dirt on the photoconductor is wiped off to some extent, and even if a small amount of dirt remains on the photoconductor, the dirt is diffused by the brush and does not affect the charging. In this way, as the cleaning member, good results were obtained in both a pad shape and a brush shape.

[0018]

As described above, according to the present invention,
When a cleaning device having a blade-shaped cleaning member and a contact charging device for directly contacting the contact charging member with the image carrier are shared, blades such as toner may slip through the cleaning device and stick to the image carrier. In this case, by immediately cleaning the image carrier with the second cleaning member, it is possible to prevent the toner particles that have slipped off the toner from adhering to the image carrier or the charging member, and the cleaning member is brought into contact with or separated from the image carrier. Since it is possible, it is possible to perform cleaning with almost no burden on the image bearing member.

[Brief description of drawings]

FIG. 1 is a partial side view of an image forming apparatus embodying the present invention.

FIG. 2 is a schematic side view illustrating a cleaning operation of the cleaning member of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Photosensitive member 2 ... Charging roller 3 ... Developing device 4 ... Transfer device 5 ... Cleaning device 6 ... Cleaning blade 7 ... Photosensitive member cleaning member 8 ... Solenoid

Claims (3)

[Claims] 1. An image carrier, a charging member that contacts the image carrier and charges the image carrier, and a developing device that develops a latent image formed on the image carrier by an exposure device. An image forming apparatus comprising: a transfer device that transfers the developed image to a transfer paper; and a cleaning device that removes and collects residual toner on the image carrier after transfer by a blade-shaped cleaning member. An image forming apparatus, characterized in that a second cleaning member capable of coming into contact with and separating from an image carrier is provided between the apparatus and a charging member. 2. The image forming apparatus according to claim 1, wherein the second cleaning member comes into contact with the image carrier when the image forming apparatus is activated. 3. The image forming apparatus according to claim 1, wherein the second cleaning member has a pad shape or a brush shape.