JPH10111598A - Fur brush developing roller brush - 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, this is to ensure that the brush fibers can be implanted in the adhesive layer. SOLUTION: In a fur brush developing roller provided with an adhesive layer 6 for implanting and holding brush fibers 7 constituting a developing brush 8 on a surface of a core body 5, the brush fibers 7 are provided.
A sharp angle portion 7A is provided at at least one end portion of the both ends which is fixed to the adhesive layer 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brush of 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. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brush for a fur brush developing roller in which a brush fiber is charged by using a voltage and is caused to fly by Coulomb force, and a root of a brush fiber constituting a developing brush is implanted and held on a surface of a core 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.

[0005] To manufacture the fur brush developing roller, first, an adhesive is applied to a core to form an adhesive layer.
After that, the brush fibers constituting the developing brush are charged by using a high voltage, are caused to fly by Coulomb force, and the brush fibers are implanted in the adhesive layer. FIG. 4 shows a simple principle diagram. The core 5 having the surface coated with the adhesive layer 6 is disposed above, the electrode plate 9 is disposed below the core 5, and the electrode plate 9 and the rotating shaft 10 of the core 5 are connected to each other with a high voltage. Connected to device 11. A large number of brush fibers 7 are placed on the electrode plate 9, the high voltage generator 11 is turned on, and the core body 5 is rotated, so that the brush fibers 7 fly. The hair is implanted in the adhesive layer 6. The adhesive layer 6 is formed by applying a paste-like adhesive to the core 5. The applied adhesive receives centrifugal force from the surface of the core 5 due to the rotation of the rotating shaft 10. Alternatively, it is necessary to set the viscosity of the adhesive to a certain degree so that the thickness of the adhesive layer 6 does not change due to the downward movement of the adhesive by the weight (self-weight) of the adhesive itself. Therefore, the brush fiber 7
.. When the hair flies and flocks the adhesive layer 6, the adhesive layer 6
May not be able to be anchored to the brush fiber 7..., And the brush fiber 7.

Further, when developing using the fur brush developing roller manufactured as described above, if the resistance of the developing roller is high, it is difficult to apply a bias voltage, so that triboelectric charging to the toner does not proceed. There is a problem that an image having a low density is formed. In order to solve this, it is common to lower the resistance value of the adhesive layer. Specifically, a mixture of an adhesive and a conductivity-imparting material such as carbon is applied to the core, and the surface of the brush fiber is surface-treated with a surfactant or the like to reduce the conductivity of the adhesive layer and the brush fiber. By doing so, the resistance of the developing roller is reduced. However, when a conductivity-imparting material such as carbon is mixed with the adhesive, the viscosity of the adhesive is further increased as compared with before the mixing, and the above-mentioned inconvenience is remarkable.

[0007]

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.
An advantage of the present invention is that the brush fibers can be reliably implanted in the adhesive layer while increasing the amount of charge to the toner and increasing the amount of toner transported to the photoconductor.

[0008]

According to the present invention, there is provided a fur brush developing roller provided with an adhesive layer for flocking and holding brush fibers constituting a developing brush on a surface of a core body. A brush of a fur brush developing roller was formed by providing an acute angle portion at least at one end portion of both end portions of the brush fiber fixed to the adhesive layer. Therefore, by making the acute angle portion of the brush fiber fly toward the surface of the adhesive layer, the impact force with the adhesive layer is gradually increased, so that the brush fiber is easily pierced into the adhesive layer.

[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. Further, by making the core body 5 into a hollow cylindrical shape and having a structure in which flanges are attached to both ends, there is an advantage that 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, inorganic salts for the purpose of electric conductivity, permittivity, separability (easiness of fraying) of the brush fiber, humidity adjustment of the fiber, and the like so as to easily fly at the time of electrostatic flocking. Treated with a surfactant or the like. Further, in order to prevent the brush resistance from changing due to the moisture absorption of the brush fiber due to the atmospheric humidity and causing the characteristics to become unstable, a moisture-proof treatment may be performed depending on the type of the fiber. And
As shown in FIG. 3A, both ends of the brush fibers 7 constituting the developing brush 8 are cut obliquely with respect to the longitudinal direction of the brush fibers 7, thereby forming acute angle portions 7A at both ends. . As described above, when the brush fiber 7 thus formed is caused to fly to the adhesive layer 6, the adhesive fiber 6
It is easy to pierce the surface, and the flocking of the brush fibers 7 can be completed in a short time. Further, even when the adhesive layer 6 is formed of an adhesive to which a conductivity-imparting agent such as carbon or metal powder is added as described above, that is, even when the viscosity is high, electrostatic flocking can be reliably performed. The sharp corner 7A
Was formed into a substantially right triangle in side view, but FIG.
As shown in (b), the tip may be formed in a brush fiber 7 having a mountain shape, or as shown in FIG. 3 (c), the brush fiber 7 may be formed in a conical shape with a tip. The shape of the brush fibers 7 is not limited to these. Further, in FIGS. 3A and 3B, the acute angle portions 7A are provided at both ends. However, as shown in FIG. 3C, the acute angle portions 7A may be provided only at one end. In this case, it is necessary to control the flying direction of the brush fiber 7 so that the acute angle portion 7A pierces the surface of the adhesive layer 6.

The resistance of the developing roller 2 will be described. For example, when the resistance of the developing roller 2 is high, electric charges are accumulated on the surface of the developing roller 2 by frictional charging between the toner and the brush fibers, and the frictional charging of the toner proceeds. Instead, the image has a low density. If the resistance of the developing roller 2 is too low,
The charge and the bias voltage leak between the photoconductor 1 and unevenness of the image and the photoconductor 1 are damaged. 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. Add conductive carbon, metal powder, metal oxide powder, etc. in order to have this conductivity,
There is a method of adding a surfactant or a conductive polymer resin.
Both are used for surface treatment of adhesives and fibers. As the brush fiber, a commercially available conductive fiber may be used.

The present invention is applicable not only to a fur brush developing roller, but also to a roller around an electrophotograph, for example, a charging roller for charging a photoreceptor, a transfer roller for removing and transferring toner charge when transferring from a photoreceptor to paper, and the like. 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]

According to the first aspect of the present invention, a fur brush developing method using a non-magnetic one-component toner is used, and the adhesive layer has a somewhat high viscosity at the time of flocking of brush fibers in the fur brush developing method. The thickness of the adhesive layer changes when the applied adhesive receives centrifugal force from the surface of the core body due to the rotation of the rotating shaft, or when the adhesive moves downward due to the weight (self-weight) of the adhesive itself. Since the brush fibers can be surely implanted in the adhesive layer while eliminating the absence of the adhesive layer, the time for implanting the brush fibers can be shortened, which is advantageous in terms of manufacturing. In addition, when the core is coated with a mixture of a conductivity-imparting material such as carbon and the like, that is, even in the case of an adhesive layer having a high viscosity, the brush fibers can be reliably secured only by changing the shape of the ends of the brush fibers. There is also an advantage that the degree of freedom in selecting an adhesive can be increased.

[Brief description of the drawings]

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

FIG. 2 is a partially cut-out longitudinal side view showing an example of a brush fiber flocking portion.

FIGS. 3A, 3B, and 3C are perspective views showing examples of brush fibers.

FIG. 4 is a principle diagram showing an electrostatic flocking method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Photoreceptor 2 Developing roller 3 Toner 4 Toner supply box 5 Core 6 Adhesive layer 7 Brush fiber 7A Sharp corner 8 Developing brush 9 Electrode plate 10 Rotating axis 11 High voltage generator

Claims (1)

[Claims] 1. A fur brush developing roller provided with an adhesive layer for implanting and holding brush fibers constituting a developing brush on the surface of a core body, wherein the fur fibers are fixed to at least an adhesive layer of both end portions of the brush fibers. A fur brush developing roller brush having an acute angle portion at one end thereof.