JPH1097135A - Fur brush developing roller - Google Patents

Abstract

(57) [Problem] By using a fur brush developing method using a non-magnetic one-component toner, it is possible to increase the amount of charge to the toner and the amount of toner transport to the photoconductor. However, an object of the present invention is to provide a fur brush developing roller that can reliably prevent hair from falling asleep at an early stage and toner from easily scattering. SOLUTION: An adhesive layer 6 for implanting and holding brush fibers 7 constituting a developing brush 8 is provided on a surface of a core body 5 and the adhesive layer 6 is provided at a root side portion of the brush fibers 7.
Is characterized in that an adhesive rises along the brush fibers at the tip end side of the brush fibers 7 from the surface of the brush fibers 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fur brush developing roller used in an electrophotographic apparatus utilizing an electrostatic image developing system such as an electrophotographic copying machine, a printer, and a facsimile. The present invention relates to a fur brush developing roller in which a brush fiber is charged by utilizing it, is caused to fly by Coulomb force, and the root of the developing brush is implanted and held on the surface of a core body with an adhesive.

[0002]

2. Description of the Related Art Various types of developing devices have been proposed for use in the above-mentioned electrophotographic apparatus. For example, magnetic toner adsorbed by a magnetic roller is transferred to a photosensitive member.

However, in the method of supplying magnetic toner using such a magnetic roller, not only is the magnetic roller expensive, but also the adjustment of the gap between the magnetic roller and the transfer member is delicate, often in units of 0.1 mm. Needs the accuracy of
There is also a disadvantage that a mechanism for satisfying the accuracy becomes complicated. In particular, when a two-component toner is used, the carrier itself has a limited life, and it is necessary to periodically replace the carrier, for example, every 10,000 copies or 20,000 copies. is there. In addition, since a magnetic substance close to a different color is internally added to the magnetic toner itself, it has been technically difficult to convert a non-magnetic one-component toner into a color toner.

[0004] In order to solve the above inconveniences, several developing methods using non-magnetic toner have been proposed. For example,
There is known a fur brush developing method in which soft bristles such as beaver bristles are formed into a cylindrical brush, and a developer is attached to the brush. This fur brush development method does not require the use of an expensive developer, and does not require a complicated apparatus that must always maintain a constant ratio of developer particles to carrier particles by using carrier particles. Things.

When developing using the above-mentioned fur brush developing method, it is important to increase the developing density and develop a clearer image. For this purpose, it is proposed, for example, to increase the length of the bristles of the brush to soften the bristles.
With such long hair, the amount of triboelectric charge is increased,
Not only can the amount of charge on the toner be increased, but also the contact area with the photoconductor increases, so that the amount of toner transported to the photoconductor increases, and the speed of the developing roller can be increased. However, the softness causes inconveniences such as the hair falling asleep early and the toner being easily scattered. By the way, by using a brush having a standard length, the inconvenience can be avoided to some extent, but in that case, the development density cannot be sufficiently increased.

[0006]

SUMMARY OF THE INVENTION In view of the above situation, the present invention is to solve the problem by using a fur brush developing method using a non-magnetic one-component toner.
Fur brush development that can increase the amount of charge to the toner and increase the amount of toner transported to the photoreceptor, but can reliably prevent hair from falling asleep at an early stage and toner from easily scattering. The point is to provide rollers.

[0007]

According to the present invention, in order to solve the above-mentioned problems, an adhesive layer for implanting and holding brush fibers constituting a developing brush is provided on a surface of a core body, and a root of the brush fibers is provided. An adhesive was formed on the side of the brush layer along the brush fiber at the tip end side of the brush fiber from the surface of the adhesive layer to form a fur brush developing roller.
In order to produce such a developing roller, the brush fibers to which a high voltage is applied are charged by electrostatic induction, fly by Coulomb force, and are anchored on the surface of the adhesive layer of the object to be planted. At the time of this electrostatic flocking, the brush fiber sucks the adhesive due to the capillary action of the brush fiber, and the adhesive rises and forms at the brush fiber tip side, or when the adhesive is cured, the adhesive is moved in the thickness direction. As a result of the contraction, the adhesive rises and forms on the tip side of the brush fiber. By forming the adhesive on the brush fiber tip side in this manner, the brush fiber can be firmly held by the adhesive, but some of the adhesive rises. Can be easily moved, and the amount of charge on the toner increases due to the increase in the amount of frictional charge. As a result, it is possible to provide a developing device in which the amount of uncharged toner is reduced and a clear image without "fog" or "unevenness" is obtained.

The viscosity of the adhesive in the adhesive layer is 3000 C
It is preferable to set in the range of PS to 10,000 CPS.

[0009]

FIG. 1 shows a fur brush developing device. The fur brush developing device includes a photoconductor 1 rotatable clockwise, a developing roller 2 rotatable counterclockwise for contacting the surface of the photoconductor 1 for development, and a toner And a toner supply box 4 for supplying the toner. The photoconductor 1
The rotation direction of the developing roller 2 is not limited to the above direction.

As shown in FIG. 2, the developing roller 2
A rotatable core 5, an adhesive layer 6 applied to the surface of the core 5, and a developing brush 8 composed of a large number of brush fibers 7 electrostatically implanted on the adhesive layer 6. Have been.

The core 5 is made of iron, aluminum, stainless steel,
When the adhesive layer 6 is formed of a conductive adhesive in addition to a metal such as brass, a plastic or a plastic that has been subjected to a conductive treatment such as plating to obtain a structure that can be grounded at the time of electrostatic flocking. Paper or the like may be used. Further, by performing a blast treatment to roughen the surface of the core body 5 by colliding the surface of the core body 5 with glass beads, aluminum powder, or the like at a high speed, the adhesiveness with the adhesive can be improved. In addition, by making the core body 5 into a hollow cylindrical shape and having a structure in which flanges are attached to both ends, the weight can be reduced, and the manufacturing cost and the running cost for rotation can be reduced.

As the kind of the adhesive constituting the adhesive layer 6, an adhesive of vinyl acetate type, acrylic type, urethane type, epoxy type or the like can be used. Further, the developing roller 2
It is also possible to add a conductivity-imparting agent, such as carbon or metal powder, to the adhesive having the above-mentioned structure in order to control the resistance. By forming the adhesive itself with elasticity, the adhesive layer 6 is configured to have an elastic function, so that the bristles become easy to move and become a soft developing brush 7, and the contact with the photoreceptor 1 is achieved. There are also advantages such as a wider width. As the resin composition forming the adhesive layer 6 having the elastic function, a resin composition having conductivity or semi-conductivity and containing a reactive organic material can be used. As the resin composition, the main components are oxyalkylene-based, saturated hydrocarbon-based, urethane-based,
Alternatively, a siloxane-based material containing a reactive organic material that becomes a solid from a liquid material by a curing reaction may be used. The viscosity of the adhesive is 3000 CPS to 10000 C
It is preferable to set in the range of PS.

The developing brush 8 is made of resin fibers such as nylon, rayon, acrylic, vinylon, polyester, vinyl chloride, or may be made of conductive fibers. In addition, as a surface treatment of the developing brush 8, an inorganic salt is used for the purpose of electric conductivity, permittivity, separability (easiness of fraying) of the brush fiber, humidity adjustment of the fiber, and the like so that the developing brush 8 easily flies during electrostatic flocking. , A surfactant or the like. Further, in order to prevent the roller resistance from changing due to the moisture absorption of the brush fibers 7 at the atmospheric humidity and the characteristics becoming unstable, moisture-proof treatment may be performed depending on the type of the fibers.

The resistance of the developing roller 2 will be described. For example, if the resistance of the developing roller 2 is high, a bias voltage is unlikely to be applied, so that triboelectric charging of the toner does not proceed.
The image has a low density. On the other hand, if the resistance of the developing roller 2 is too low, the charge and the bias voltage leak between the developing roller 2 and the photosensitive member 1, causing image unevenness and damage to the photosensitive member 1. For this reason, it is necessary to appropriately control the resistance value of the developing roller 2, and a conductive adhesive or brush fiber is used as the means as described above. There are methods of adding conductive carbon, metal powder, metal oxide powder, and the like, and adding a surfactant and a conductive polymer resin in order to have this conductivity. Both are used for surface treatment of adhesives and fibers.
As the brush fiber, a commercially available conductive fiber may be used.

A method of implanting the developing brush 8 will be described. When a high voltage is applied, the brush fiber 7 is charged by electrostatic induction, flies by Coulomb force, and is anchored on the surface of the adhesive layer 6 as a target. The hair is planted.
At the time of the flocking, the brush fiber 7 sucks the adhesive due to the capillary action of the brush fiber 7, and the adhesive rises up along the brush fiber 7 at the tip side of the brush fiber 7, or the adhesive hardens. At this time, the adhesive contracts in the thickness direction between the brush fiber 7 and the core body 5, so that the adhesive rises and forms on the tip side of the brush fiber 7. By forming the rising portion 6A of the adhesive (see FIG. 2) on the tip side of the brush fiber 7 in this manner,
While the brush layer 7 can be easily moved by forming the adhesive layer 6 thin, the brush fiber 7 can be firmly held by the adhesive, and the amount of charge to the toner can be reduced by increasing the amount of frictional charge. Can be increased. As a result, the life of the roller is long, the speed of the developing roller is increased, and if the printer is used, the number of processed sheets increases, and a clear image without "fog" or "unevenness" can be obtained. is there. The present invention is applied not only to a fur brush developing roller, but also to a roller around an electrophotograph, for example, a charging roller for charging a photoconductor or a transfer roller for removing and transferring toner charge when transferring from a photoconductor to paper. The present invention can be applied not only to a copying machine but also to various electrophotographic apparatuses using an electrostatic image developing system such as a printer and a facsimile.

[0016]

The fur brush development method using a non-magnetic one-component toner is used. In the fur brush development method, when the brush is implanted, the capillary phenomenon of the brush fiber and the shrinkage phenomenon of the adhesive caused when the adhesive is cured. By using a brush fiber, even if the brush fiber has a long dimension, it can be firmly fixed to the adhesive layer, but it can be easily moved near the root of the brush fiber. By increasing the amount of charge on the toner, the contact area with the photoreceptor can be increased,
As a result of increasing the amount of toner transported to the photoconductor, the life of the roller is extended, and the speed of the developing roller is increased. The result is a clear image with no "unevenness". In addition, it is possible to prevent the hair from falling asleep and the toner from scattering, and it is also possible to reduce the amount of hair loss and prolong the life of the brush. Therefore, increasing the amount of toner transported to the photoreceptor in order to increase the image density utilizes the capillary phenomenon of the brush or the contraction phenomenon of the adhesive which occurs when the adhesive is cured without providing a special structure. This is advantageous in terms of cost.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional side view showing a configuration of a developing device.

FIG. 2 is a longitudinal sectional side view of a main part of a developing roller.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Photoreceptor 2 Developing roller 3 Toner 4 Toner supply box 5 Core 6 Adhesive layer 6A Standing part 7 Brush fiber 8 Developing brush

Claims (2)

[Claims] An adhesive layer for flocking and holding brush fibers constituting a developing brush is provided on a surface of a core body.
A fur brush developing roller, wherein an adhesive is formed upright along a brush fiber at a tip side of the brush fiber from a surface of the adhesive layer at a root side portion of the brush fiber. 2. The adhesive of the adhesive layer has a viscosity of 3000.
2. The fur brush developing roller according to claim 1, wherein the developing brush is set in a range of CPS to 10,000 CPS.