JPH0990742A - Developing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a developing device using one component developer in which adhesion at an abutting portion between a developer carrier and a developer regulating member can be prevented in a simple method in, for instance, a copying machine, a printer, a facsimile, and the like in which recording on paper is conducted by an electrophotographic method. SOLUTION: A developing device is provided with a developer carrier which supports and carries a developer 33, and a developer regulating member 34 which is made of a rubber-like elastic plate and regulates the developer supported by the developer carrier 33 to a certain amount as abutting the developer carrier 33. A small amount of powdered lubricant is previously applied to the face side of the developer regulating member 34 abutting the developer carrier 33 or to the surface of the developer carrier 33, and the developer regulating member 34 is brought into contact with the developer carrier 33.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing device for recording on paper by an electrophotographic method, which is applied to a copying machine, a printer, a facsimile, etc., and which uses a one-component developer.

[0002]

2. Description of the Related Art In a developing device of an electrophotographic apparatus, a developer carrier for supplying a developer to a surface of a photoreceptor on which a latent image is formed is used, and the surface of the developer carrier is made of an elastic material such as rubber. There is a blade in which the amount of the developer on the surface of the developer carrier is regulated and the developer is uniformly applied by bringing the blade into contact with the blade. JP-A-55-140858 and JP-A-58-58 disclose the techniques of this type.
116559 and Japanese Patent Laid-Open No. 59-45468.

Further, in a cleaning device of an electrophotographic apparatus, when a cleaning blade made of urethane rubber or the like is set on a photosensitive drum, it is possible to prevent the urethane rubber from being caught in the surface of the photosensitive drum or a contact portion of the cleaning blade. For this reason, it is generally known to apply a small amount of lubricating powder made of vinylidene fluoride resin or the like. When the surface friction coefficient is high, the entrainment of urethane rubber occurs due to the rotational force of the photosensitive drum. When the urethane rubber is entangled, poor adhesion of the blade occurs, resulting in poor cleaning.

[0004]

Even in the developing device of an electrophotographic apparatus, an elastic plate material such as rubber is used as a developer regulating member, and the developer carrying member is regulated with no developer, for example, in a new state. When the members are brought into contact with each other and left for many days (one week or more), both of them adhere to each other at the contact portion between the carrier and the regulating member. This is caused by the property that even if they have good surface properties, they are likely to adhere to each other when they come into contact with each other.

In particular, when a developer bearing member having a metal surface and having a surface roughness Rz of 10 μm or less, urethane rubber, siligon rubber, fluororubber or the like is used as a developer regulating member, adhesion easily occurs.

When the above-mentioned adhesion occurs, the driving of the developing device itself is locked, the drive is not transmitted even if the developer is replenished, and no image is produced, or the drive system of the main assembly of the device is damaged. Will cause damage.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a developing device capable of preventing the developer carrying member and the developer regulating member from adhering to the abutting portion by a simple method. is there.

[0008]

In order to achieve the above object, the structure of the developing device according to the first aspect of the present invention comprises a developer carrying member carrying and carrying a developer, and rubber-like elasticity. In a developing device having a developer regulating member made of a plate material and abutting against the developer bearing member to regulate the amount of the developer carried on the developer bearing member to a constant amount, It is characterized in that a small amount of a powder lubricant is applied in advance to the surface side or the surface of the developer carrier to bring the developer regulating member into contact with the developer carrier.

The developing device according to the second aspect of the present invention is configured such that a small amount of developer is applied in advance to the side of the developer regulating member which is in contact with the developer carrying member or the surface of the developer carrying member. The regulating member is brought into contact with the developer carrying member.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION An example of an embodiment in which the present invention is applied to a developing device adopted in an electrophotographic copying machine (hereinafter referred to as copying machine) which is an image forming apparatus will be described below.

FIG. 1 is a schematic configuration diagram of a copying machine according to an embodiment of the present invention. In this copying machine, the image of the document 11 placed on the document table 10 is displayed by the irradiation lamp 12.
a, the mirror 12b, and the lens 12c, and is read by the image reading device 13, and the data is read by the image processing device 1.
4 In FIG. 1, the surface of the photoconductor 1 as an image carrier, which is rotationally driven in the direction of arrow A, is uniformly charged by the charger 2. Then, on the surface of the photoconductor 1, based on the data from the image processing device 14, an exposure device 15 including a semiconductor laser, a polygon mirror, a reflection mirror, etc.
A latent image corresponding to the image of the original 11 is formed.

The latent image on the photosensitive member 1 is a non-magnetic toner (hereinafter referred to as "toner") as a developer from a developing roller 33 as a developer carrying member of the developing device 3 at a portion facing the developing device 3. Is supplied and developed to form a toner image. This toner image is transferred / transferred to, for example, a transfer paper (not shown) that is conveyed by the registration roller 4 at a timing.
Transferred by the transfer device 5. The transfer paper on which the toner image is transferred is conveyed by the transfer / conveyance device 5, and when passing through the fixing device 6, the toner image is fixed and discharged to the outside of the machine.

The untransferred toner remaining on the photoconductor 1 after the toner image is transferred is scraped off from the photoconductor 1 by the cleaning brush roller 71 of the cleaning device 7 and collected by the cleaning device 7. Then, the surface of the photoconductor 1 after cleaning is cleaned by the static elimination lamp 8
The residual charge is removed by.

Next, a specific example of the developing device 3 will be described with reference to FIG. In FIG. 2, the toner storage portion 3a of the developing device 3 is driven to rotate in the direction of arrow D in the drawing,
Agitating / conveying members 31a and 31b for agitating and conveying the toner are provided.

Further, the developing device 3 is formed with an opening 3b at a position facing the photoconductor 1, and the opening 3b is formed.
Is provided with a developing roller 33 as a developer carrier that is made of a conductive material to which a predetermined bias voltage is applied and is rotationally driven in the direction of arrow B (counterclockwise) in the drawing. The developing roller 33 is rotationally driven in the direction of arrow C (counterclockwise direction) in the drawing and is in pressure contact with a supply roller 32 as a developer supply member made of an elastic foam material.

Further, the rotation direction of the developing roller 33 (arrow B
Direction), on the surface of the developing roller 33 on the downstream side of the pressure contact portion 3c with the supply roller 32 and on the upstream side of the opening portion 3b, an elastic plate material such as urethane rubber is formed, and one end portion of the developing device is formed. A free end portion of a regulation blade 34 as a developer regulation member fixed to the casing is in contact with the casing.

In the developing device 3 having the above structure,
The toner in the toner container 3a is agitated and conveyed by the stirring and conveying members 31a, 31.
It is fed to the supply roller 32 while being stirred by b, and is carried on the surface of the supply roller 32. Supply roller 32
The toner carried on the developing roller 33 is supplied onto the developing roller 33 by an electrostatic force due to frictional charging caused by a peripheral speed difference between the supplying roller 32 and the developing roller 33 at a pressure contact portion 3c with the developing roller 33. The toner supplied onto the developing roller 33 is regulated by the contact portion 3d with the regulating blade 34 to control the surplus toner to form a uniform toner layer. The toner formed in the uniform layer form adheres to the surface of the photoconductor 1 due to the potential difference between the developing roller 33 and the latent image on the photoconductor 1 to form a toner image.

When the developing device 3 is depleted of toner, for example, when the developing device is a new one and left for a long period of time, both of them adhere to each other at the contact portion between the developing roller 33 and the regulating blade 34 shown in FIG. To do.

This is the developing roller 33 and the regulating blade 34.
It easily occurs when the surface property with is good. In the case of this embodiment,
As the developing roller 33, a roller having a metal surface and Rz of 10 μm or less is used. FIG. 4 shows the relationship between the state of the developing device left unloaded and the load torque. As shown in FIG. 4, the load torque is tripled in 30 days of leaving because of the adhesion between the developing roller 33 and the regulating blade 34 at the contact portion. in this case,
Even if the developing device was replenished with the developer, the drive was not transmitted and no image appeared. Also, the gear of the developing device was damaged.

In the present invention, a small amount of powder lubricant (vinylidene fluoride resin: product name "Kainer" manufactured by Pennwalt, USA) is applied to the contact surface side 34a of the regulating blade 34 with the developing roller 33 shown in FIG. , The developing device was left without the developer. As a result, as shown in FIG. 4, the load torque of the developing device did not increase. Further, even after being left for 30 days, there was no problem even if toner was put in and development was started.

Similarly, even if a small amount of developer is applied to the contact surface side 34a of the regulating blade 34 with the developing roller 33 and the developing device is left without the developer, the load torque of the developing device is not increased. There was no The particles of the powder lubricant or the developer were sandwiched between the abutting portions of the developing roller 33 and the regulating blade 34, so that the sticking of the developing roller 33 and the regulating blade 34 could be prevented.

However, if a large amount of the powder lubricant is put in the developing device, density unevenness occurs in the solid image portion. In addition, the charging property of the toner may be poor. The amount of the powder lubricant is preferably such that it can be applied with a cloth.

In the above embodiment, the powder lubricant or the developer is applied to the contact surface side of the regulation blade 34 with the developing roller 33, but a small amount of the powder lubricant or the developer is applied to the surface of the developing roller 33. Can be applied, and the desired effect can be obtained.

[0024]

From the above, according to the first invention,
Since a small amount of powder lubricant is applied in advance to the developer bearing member contact surface of the developer regulating member or the surface of the developer bearing member, the developer regulating member is brought into contact with the developer bearing member. Adhesion does not occur at the abutting portion between the developer regulating member and the developer carrying member even if left unattended for many days. With such a simple method, it is possible to prevent the load torque from being abnormal due to the adherence of the developer regulating member and the developer carrier.

According to the second aspect of the invention, a small amount of the developer is applied in advance to the surface of the developer regulating member which is in contact with the developer bearing member or the surface of the developer bearing member, and the developer regulating member is set to the developer. Since it is brought into contact with the carrier, the same effect as that of the above-mentioned first invention can be obtained. In addition, the application of the developer has an advantage over the application of the powder lubricant in that there is no fear of poor charging property of the developer.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing an example of a copying machine to which the present invention can be applied.

FIG. 2 is an internal schematic configuration diagram of a developing device used in the copying machine.

FIG. 3 is a schematic view of a contact surface between a regulation blade of a developing device and a developing roller.

FIG. 4 is a relationship diagram between a state where the developing device is left and a load torque.

[Explanation of symbols]

 3 developing device 33 developing roller 34 regulating blade 34a abutting surface side

Claims (2)

[Claims] 1. A developer carrying member carrying and carrying a developer, and a rubber-like elastic plate member contacting the developer carrying member to bring the developer carried by the developer carrying member to a predetermined amount. In a developing device equipped with a developer regulating member for regulating, a small amount of powder lubricant is applied in advance to the contact surface side of the developer regulating member with the developer carrier or the surface of the developer carrier to develop the developer. A developing device, wherein a regulating member is brought into contact with a developer carrying member. 2. A developer carrying body carrying and carrying a developer, and a rubber-like elastic plate material, which is in contact with the developer carrying body and regulates the developer carried on the developer carrying body to a predetermined amount. In the developing device including the developer regulating member, a small amount of developer is applied in advance to the contact surface side of the developer regulating member with the developer carrying member or the surface of the developer carrying member to regulate the developer. A developing device, wherein a member is brought into contact with a developer carrying member.