JPS62115181A - Developing device - Google Patents

Abstract

PURPOSE:To increase the quantity of developer carried from a rotating brush to a developer carrier to prevent the reduction and the disturbance of development density by rotating the developer carrier and the rotating brush in directions opposite to each other and rotating the brush at a peripheral speed equal to or higher than that of the carrier. CONSTITUTION:An aperture 21 is formed in a developer vessel 20 where a developer 19 is stored in a developing device, and an endless developer carrier 22 which holds and carries the developer 19 is supported freely rotatably in the part of the aperture 21. A rotating brush 26 is provided freely rotatably in a position contacting with or close to the carrier 22 in a developer storage part of the vessel 20, and fibrous fur 28 is implanted on the outside peripheral surface of the brush 26. The carrier 22 and the brush 26 are rotated in directions of arrows (b) and (c) opposite to each other, and the brush 26 is rotated at a peripheral speed equal to or higher than that of the carrier 22. Thus, the quantity of the developer 19 carried from the brush 26 to the carrier 22 is increased and the developer 19 is flowed positively to a rubbing part.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to electrostatic printers and copying machines applying electrophotography;
The present invention relates to a developing device in an image forming apparatus such as a printer.

Conventional technology Conventionally, a developing device in which a rotating brush such as a fur brush triboelectrically charges a developer (-1) and supplies this charged developer to a developer carrier for development is disclosed in Japanese Patent Application Laid-Open No. 59-189378.
There is a device disclosed in the above publication, and its configuration is shown in FIG.

In FIG. 2, 1 is a photosensitive drum, 2 is a developer carrier, 3 and 4 are rotating brushes having soft fibers on the surface, 6 is a developer, 6 is a developer regulating member, and 7 is a developer container. shows.

The developer carrier 22, the rotating brush 3, and the rotating brush 4 are
As shown in the figure, all rotate in the same direction, and the peripheral speed ratio is 5:
The developer 5 contained in the developer container 7 is first charged by friction as the rotating brush rotates, and then supplied to the rotating brush 3.

The developer 5 supplied to the rotating brush 3 is further triboelectrically charged between the rotating brush 3 and the inner surface of the developer container 7 and between the rotating brush 3 and the developer carrier, and then supplied to the developer carrier 2. be done. The developer 5 then supplied to the developer carrier 2
The layer thickness is regulated to a predetermined layer thickness by the regulating member 6,
It flies towards the electrostatic image on the photoreceptor drum 1 (~ is developed).

Problems to be Solved by the Invention However, in such a developing device, the developer carrier 2 and the rotary brush 3 that supplies the developer 5 to the developer carrier 2 rotate in the same direction, and the peripheral speed of the developer carrier 2 rotates in the same direction. Since the ratio is 5:1, the developer carrier 2 and the rotating brush 3 move in opposite directions at the rubbing area between the developer carrier 2 and the rotating brush 3, causing rotation. The brush 3 has a stronger force acting on the brush 3 to remove the developer 6 from the developer carrier 2 than the force that takes the developer 5 into the rubbing portion and causes it to adhere to the developer carrier 2. The force for conveying the developer 6 in the direction is weakened, and the required amount of developer 5 is not supplied to the developer carrier 2. This was generated on the developer 6 that was supplied to the second stage.

Therefore, when developing with the conventional developing device ift, the developed image density becomes low, and the number of fibers of the rotating brush 3 is generated in the developed image (visual image). The recorded image quality of the device was significantly improved.

The present invention solves the above-mentioned problems by supplying the required amount of developer to a developer carrier with a simple structure, preventing a decrease in developer density and disturbance of a developed image, and improving the recorded image quality. The object is to provide a developing device that can be improved.

Means for Solving the Problems The technical means of the present invention for solving the above conventional problems is to reverse the rotation of the developer carrier and the rotating brush (rotating brush 3 in the conventional example) that is in contact with or in the vicinity of the developer carrier. Along with the direction,
The circumferential speed of the rotating brush is configured to be equal to or higher than the circumferential speed of the developer carrier.

action The effect of this technical means is as follows.

That is, by making the rotation of the developer carrier and the rotating brush in opposite directions, and by configuring the rotating brush so that the circumferential speed is equal to or higher than the circumferential speed of the developer carrier, the rotation plan can be adjusted. As the amount of developer transported in the direction of the developer carrier increases, the developer carrier and the rotating brush move in the same direction at the rubbing area between the developer carrier and the rotating brush, and the rubbing area increases. The developer is actively flowing into the area.

Therefore, as in the past, the necessary amount of developer cannot be supplied during special holidays, or the fibers of the rotating brush may cause the developer to be supplied to the developer carrier. Even if development is performed, the developed image density will not be lower than 1 degree and the developed image will not be disturbed.

EXAMPLE Hereinafter, an example of the present invention will be described based on the accompanying drawings.

In FIG. 1, reference numeral 13 denotes a photoreceptor drum, which is a developer carrier, and is coated with a photoreceptor 16 such as zinc oxide or selenium on the periphery of a base 14, such as at A, and is indicated by the arrow a.
Rotate in the direction. 16 is a charger that generates, for example, a negative corona by activating the high voltage DC power supply 17;
The entire surface of the photosensitive moon 15 is charged to 6/, -2 negative polarity.

Reference numeral 18 denotes an optical section that projects an optical image according to an input image signal (not shown) onto the photoreceptor drum 13 to form an electrostatic image. 19 is a developer; 20 is a developer container having an opening 21 at one end and housing the developer 19;

22 is a developing roller which is a developer carrier, for example, kl.
It is made of a metal material such as , SUS, etc., and its outer peripheral surface is roughened to have fine irregularities. The developing roller 22 is rotatably supported in the opening 21 of the developer container 20, faces the photosensitive drum 13 with a predetermined gap (approximately 15,071 m), and rotates in the direction of the arrow.

Reference numeral 26 denotes a fur brush which is a rotating brush, and is constructed by planting fiber hairs 28 of fibers such as rayon on the outer peripheral surface of a mandrel 27, and is rotatable to a position where it rubs against the developing roller 22 in the developer container 20. The developing roller 22 is supported by the developing roller 22 and rotates in a direction opposite to the rotating direction of the developing roller 22 (in the direction of arrow C). Further, the fur brush 26 is driven such that its peripheral speed is, for example, 1.5 times the peripheral speed of the developing roller 22.

3o is a blade made of an elastic material, such as rubber or resin.

It is made of a PI such as metal, and is supported on the upper part of the developer container 2o so that one side of the developer roller 22 slides against the outer peripheral surface of the developing roller 22 when there is no developer 19 therein.

A scraping plate 36 has one end fixed to the inner surface of the developer container 20 and the other end in contact with the bristles 28 of the fur brush 26 to regulate the amount of developer in the bristles 28 to an appropriate amount.

Next, the operation of the configuration of this embodiment will be explained.0 The photosensitive material 16 is fully charged, for example, to a negative polarity by the charger 16, and then an optical image is projected on the photosensitive drum 13 by the optical section 18. For example, minus 800
It forms an electrostatic image of v and heads toward the development area E.

As the fur brush 26 rotates in the direction of arrow C, the developer 19 contained in the developer container 20 is removed by its bristles 28.
The liquid is supplied to the inside, is stirred, and becomes, for example, positively charged. The amount of developer 19 supplied into this special top 28 is determined by the scraping plate 36.
It is regulated to an appropriate amount.

The positively charged developer 19 is conveyed toward the developing roller 22 by the fur brush 26.
The developing roller 22 further applies a uniform positive charge at the rubbing portion, and is supplied to the developing roller 22.

At this time, the developer 19 supplied to the developing roller 22 is such that the peripheral speed of the fur brush 26 is set to, for example, 1.5 times the peripheral speed of the developing roller 22, and the fur brush 26 and the developing roller 22 are Since it moves in the same direction in the rubbing part, it actively flows into the rubbing part and is supplied.

The developer 19 supplied to the developing roller 22 is then regulated to a predetermined layer thickness (approximately 4071 m) by the blade 30 and reaches the developing area 2, where a negative DC voltage (approximately 200 V) is applied to the developing roller 22 by the DC power supply 31. By applying the voltage, it flies toward the electrostatic image on the photoreceptor drum 13 and develops the electrostatic image.

As described above, according to the developing device of this embodiment, the developing roller 2
2 and the fur brush 26 are rotated in opposite directions, and the circumferential speed of the fur brush 26 is set to be equal to or higher than the circumferential speed of the developing roller 22. As the amount of the developer 19 conveyed in the direction 22 increases, the amount of the developer 19 conveyed in the direction of
The fur brush 26 moves in the same direction, and the developer 19 actively flows into the rubbing portion.

Therefore, the necessary amount of developer 19 cannot be supplied to the developing roller 22 as in the conventional case, or the fibers of the fur brush 26 (
The openings of the hairs 28) are no longer generated on the developer 19 supplied to the developing roller 22, thereby preventing a decrease in developer density during development and disturbance of the developed image.
The quality of recorded images of a recording apparatus using this developing device can be improved.

Effects of the Invention 10A, -7 The present invention allows the developer carrier provided in the developer container and the rotating brush to rotate in opposite directions, and the circumferential speed of the rotating brush to be faster than the circumferential speed of the developer carrier. Since it is configured to be the same or higher, the required amount of developer is always well supplied to the developer carrier, preventing a decrease in developer density during development and disturbances in the developed image. In addition, it is possible to improve the recorded image quality of a recording apparatus using this developing device, and the practical effects thereof are great.

[Brief explanation of drawings]

FIG. 1 is a central sectional view of a main part of a developing device according to an embodiment of the present invention, and FIG. 2 is a central sectional view of a main part of a conventional developing device. 2o...Developer container, 21...Opening,
22... Developer carrier, 26... Rotating brush.

Claims (1)

[Claims] A developer container that generally has an opening and stores developer; an endless developer carrier that is rotatably supported by the opening in the developer container and holds and conveys the developer; and the developer container. a rotating brush having fibrous bristles on an outer circumferential surface, the rotating brush being rotatably supported in a position in contact with or close to the developer carrying member in the developer accommodating portion of the developer storage unit; A developing device in which the rotating brush rotates in the opposite direction and the peripheral speed of the rotating brush is equal to or higher than the peripheral speed of the developer carrier.