JPH035576B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fur brush developing method for electronic copying machines.

A fur brush developing method is known as a developing method in which a non-magnetic toner is supplied to an electrostatic latent image formed on the surface of a photoreceptor. In this fur brush development method, non-magnetic toner supplied by a fur brush roller that rotates while in contact with the surface of the photoreceptor is guided to the surface of the photoreceptor, and the electrostatic latent image formed on the surface of the photoreceptor is removed. The particle size of the non-magnetic toner used here is generally 1 to 25 μm.
It has a wide particle size distribution.

However, in the case of non-magnetic toner having a particle size of 5 μm or less, the fur surface of the fur brush roller is coated with a small amount of toner, so the amount of toner supplied to the surface of the photoreceptor is small. Therefore, the image density is low and image fogging occurs. Further, as described above, when the toner particle size becomes small, it is easy to cause F.F. (film forming), and the toner becomes difficult to be charged, which inconveniently shortens the life of the fur brush roller. Furthermore, the presence of non-magnetic toner with a particle size of about 25 μm has the disadvantage that resolution is reduced, such as making it impossible to develop fine electrostatic latent images as they are.

In this way, the toner used in the conventional fur brush development method has a wide particle size distribution (1 to 25 μm).
As a result, the toner density becomes non-uniform and stable images cannot be obtained.

The present invention has been made in view of the above-mentioned circumstances, and its object is to provide a fur brush developing method that can make toner density uniform and obtain stable image density.

The present invention will be explained below based on an embodiment shown in the drawings. In FIG. 1, reference numeral 1 denotes an image carrier, such as a photoreceptor, of a dry type electronic copying machine, which is designed to rotate in the direction of the arrow. A developing device 5 consisting of a fur brush roller 2 and a toner supply box 4 for supplying non-magnetic toner 3 to the fur brush roller 2 is provided adjacent to the photoreceptor 1. The fur brush roller 2 is formed by providing a urethane layer 7 on the outer peripheral surface of a mandrel 6, and planting short fur 9 on the outer peripheral surface of the urethane layer 7 via a conductive adhesive layer 8. This fur 9
is adapted to come into sliding contact with the surface of the photoreceptor 1. Furthermore, the above Fur 9 has a specific resistance of 10 ⁶ to ^{10 4} Ω.
It is made of rayon fibers with a length of 1.5 mm, a thickness of 1.5 denier, and a surface density of 20,000 fibers/cm ² . Further, the lower outer circumferential surface of the fur brush roller 2 is surrounded by a conductive case 10 that is integrated with the toner supply box 4, and the fur 9 comes into contact with the inner surface of the conductive case 10. . Furthermore, the particle size of the non-magnetic toner 3 contained in the toner supply box 4 is in the range of 10 to 15 μm, and this is graphed as shown by the solid line curve in FIG. The particle size distribution (10 to 15 μm) is narrower than the conventional particle size distribution (1 to 25 μm).
m) is selected and used.

Next, a fur brush developing method using the developing device 5 configured as described above will be described. When the electrostatic latent image formed on the surface of the photoreceptor 1 faces the developing device 5 as it rotates, the non-magnetic toner adhered to the fur 9 by the fur brush roller 2 rotating in the direction of the arrow. 3 is guided to the surface of the photoreceptor 1, is attracted to the electrostatic latent image, and is developed. The developed toner image is guided to a transfer section (not shown) as the photoreceptor 1 rotates,
Transferred to transfer paper. At this time, since the nonmagnetic toner 3 has a narrow particle size distribution and uniform particle size, the amount of toner adhering to the fur brush roller 2 is constant, and a stable image density can be obtained.

As explained above, this invention uses a non-magnetic toner with a particle size of 10 to 15 μm in the fur brush development method, so the toner adheres to the fur of the fur brush roller compared to the conventional wide particle size distribution. A clear toner image with a constant amount and stable image density can be obtained. Moreover,
Since toner with a fine particle size that is likely to form a film on the fur is not used, the toner's chargeability is improved and the durability of the fur brush roller is also improved.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of a developing device showing an embodiment of the present invention, and FIG. 2 is a graph showing toner particle size distributions of the present invention and the conventional toner. 1... Photoreceptor (image carrier), 2... Fur brush roller, 3... Non-magnetic toner.

Claims (1)

[Claims] 1 In a developing method in which a fur brush is used to supply toner to an image bearing member on which an electrostatic latent image has been formed to develop the electrostatic latent image, a roller with short bristled fur brushes is used to supply toner to an image bearing member on which an electrostatic latent image has been formed. A fur brush developing method characterized by supplying toner of 15 μm and rotating the roller to bring the short hair fur brush of the roller into sliding contact with the image carrier to develop an electrostatic latent image on the image carrier.