JPS63202772A - Developing device - Google Patents

Abstract

PURPOSE:To form a uniform and stable thin layer of electrostatically charged toner on a toner carrier by forming grooves in the surface of the toner carrier slantingly to its moving direction. CONSTITUTION:The groove 10 are formed on the surface of a developing roller 1 at a tilt angle to its moving direction. The moving direction of the toner 7 is composed of a component f1 in the rotating direction of the developing roller 2 and a component f2 in the direction of the rotary shaft. This toner 7 moves under the guidance of the grooves 10 and a conveying force f2 parallel to the rotary shaft operates on a blade press-contacting surface 4, so that no toner is neither deposited nor caked on the blade press-contacting surface 4. Then the toner which is charge electrostatically and uniformly is supplied to a photosensitive drum to develop a latent image. Thus, the groove are formed in the developing roller, so that toner is prevented from being deposited and caked on the blade press-contacting surface to eliminate the stripe irregularity of the electrostatically charged toner thin layer, thereby improving picture quality.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a developing device used in electrophotographic copying machines, printers, and the like. More specifically, the present invention includes -
The present invention relates to a developing device that can stably form a uniformly charged thin layer of component-based toner on a toner carrier.

Conventional technology
i"Eryo01→・A%fff#SVO,a*-+ After developing (visualizing) by supplying toner to the surface of the photoconductor using a developing device, the obtained toner image is printed on paper, etc. An image is obtained by transferring it to a transfer material.

In a developing device used in such an electrophotographic copying machine, the layer thickness of the charged toner carried on the surface of a toner carrier such as a developer [1-La and the like and supplied to the photoreceptor is constant,
It is important to provide a thin layer of uniformly charged toner to the photoreceptor surface. For this reason, as shown in FIG. 3a, it is necessary to stably regulate the uniform toner layer thickness on the surface of the developing roller 2 at the pressure contact surface near the tip of the blade 4 that regulates the toner layer thickness. However, for example, if toner sticks, fuses, or dust adheres to the pressure contact surface or the tip of the blade 4 due to long-term use, the toner's entry into the friction area (friction area) is obstructed, and after passing the blade,
The thin layer of charged toner becomes non-uniform in the direction of the rotation axis of the developing roller, causing toner shading on the surface of the developing roller (see Figure 3), resulting in streaks and unevenness in the resulting image.

Conventionally, in a developing device using a two-component developer or a developing roller with an internal magnet that uses magnetic toner as a developer, there are two components on the developing roller that are perpendicular to the direction of rotation or intersecting at a predetermined angle. There is an apparatus in which grooves are provided and developer is moved along the grooves using magnetic attraction.

Problems to be Solved by the Invention However, in recent years, the reliability of electrophotographic copying machines has improved,
From the viewpoints of miniaturization, cost reduction, and colorization, a single-component developing method is desired that has a simple structure and can stably control uniformly charged toner. There is a need for a developing device that has the following properties.

The present invention provides a developing device that uses a one-component developer consisting only of toner as a developer, which has a simple structure and can easily form a uniform to stable thin layer of charged toner on a developing roller. The purpose is to

Conventionally, development has been carried out in a developing device that uses such a developing roller without an internal magnet and uses only non-magnetic toner as a component developer, and in which no magnetic attraction force acts between the developing roller and the developer. None had grooves for anti-fusion IL.

Means for solving the problem, that is, the present invention provides a toner carrier having a moving surface that carries toner, and friction of the toner supplied onto the toner carrier to increase the charging and layer thickness of the toner. To provide a non-magnetic one-component toner developing device having a layer thickness regulating member for regulating the thickness, characterized in that the surface of the toner carrier is provided with a groove inclined with respect to the direction of movement thereof. It is.

Function: In the developing device of the present invention, by providing the surface of the developing roller with an angle 114 with respect to its moving direction, the toner on the blade pressure contact surface and its vicinity is moved diagonally, and the moving direction of the toner is adjusted to the developing roller. (the sum of the component in the rotational direction and the component in the rotational axis direction), a conveying force parallel to the rotational axis always acts on the blade pressure contact surface.

Next, the present invention will be described in more detail based on examples and with reference to the drawings.

Embodiment 1 FIG. 1 is a sectional view showing an example of an integrated device of the present invention. In FIG. 1, a developing device 1 includes a developing roller 2 which is a rotating body adjacent to a photoreceptor 100, a supply roller 3 that supplies toner to the developing roller, and a regulating blade 4 that is pressed around the developing roller 2. It consists of a layer thickness regulating member 5 provided, an agitator 6 for stirring and replenishing toner, and a casing 8 that supports and accommodates these and also stores toner 7.

First, the supply roller 3 is made of elastic silicone rubber foam, polyurethane foam, or the like, and contacts the developing roller 2 with a constant pressing force (biting amount of 0.5 to 1 mm) in the counterclockwise direction in the figure. It rotates and supplies toner onto the developing roller 2.

The rotation speed of the supply roller 3 is set depending on the amount of toner required.

Next, the developing roller 2, which is a toner carrier, is made of a conductive material such as aluminum, or a member whose surface with a conductive part is coated with a high resistance layer, and the developing roller 2 carries toner on its surface. rotate counterclockwise, photoreceptor 10
Supply toner to 0. As shown in FIG.
42 width approx. 30μm, depth approx. 8μm, bitch approx. 100μm
The measurement was carried out using a Surfcom 550A surface roughness meter (manufactured by Tokyo Seimitsu).

The layer thickness regulating member 5 is rotatably attached to the casing 8, and the regulating blade 4 made of a charging member such as silicone rubber attached to the tip of the member 5 is connected to a spring 9 attached to the opposite end. The blade is pressed against the circumferential surface of the developing roller 2 in a direction opposite to the rotating direction of the developing roller 2 (similar blade).

Next, the operation when performing development using the apparatus of the present invention will be explained using FIGS. 1 and 2. According to the apparatus of the present invention, the toner 7 stored in the casing 8 is agitated and replenished by the agitator 6, and is supplied onto the circumference of the developing roller 2 by the supply roller 3. As the developing roller rotates, the toner on the developing roller 2 reaches the friction area X formed by the developing roller surface and the tip of the regulating blade 4, and the thickness of the toner is regulated by the blade 4. 4 and the developing roller 4,
It is charged according to a triboelectric series between materials.

In the developing device of the present invention, by providing the surface of the developing roller with grooves having an angle with respect to the direction of movement thereof, the direction of movement of the toner 7 on the blade pressure contact surface and the vicinity thereof is controlled by the component of the rotational direction of the developing roller. 1 and the component element in the direction of the rotation axis, and the toner passes obliquely through the blade pressure contact surface (see Figure 4, 1).In other words, the toner has sufficient energy until it passes through the blade pressure contact surface. Since it is not subjected to frictional electrification, the binding force (mirror force) on the developing roller is extremely small, and as a result, a sideways sliding phenomenon of toner occurs in the regulated area near the contact surface of the blade, and at this time the developer is guided into the inclined groove. and move.

In this way, in the present invention, since the inclined groove is provided on the surface of the developing roller, a conveying force parallel to the rotating shaft always acts on the blade pressure contact surface. A thin layer of uniformly charged toner is formed, preventing sticking.

Development [1-] The thin layer of uniformly charged toner formed on the roller is held on the surface of the development roller by mirror image force and mechanical adhesion force, and is conveyed to the development area facing the photoreceptor 100. Subjected to development.

On the other hand, in a conventional one-component developing device in which the developing roller does not have a groove, as shown in FIG. That is, since there are only components perpendicular to the rotation axis, if toner sticks to the tip of the blade 4, the toner is prevented from entering the friction area X, and toner shading occurs on the surface of the developing roller.

Incorporating the device of Example 1 into a commonly used copying machine to, oo
When continuous copying of o sheets was carried out, a copy sample was obtained which had very good image quality without any toner aggregation on the blade pressure contact surface or sleeve surface, no streaks or unevenness. In addition, during the test, the image density of the solid black area was 1.3 to 1.4, and compared to Comparative Example 1 described later, the toner carrier of the present invention also has excellent developer transport performance. I understand.

The average particle size of the toner used in the developing device of Example 1 is:
13.06 μm, and the particle size distribution is 5 μm or less.
．． 00%, 10 μm or less 6.1%, 20 μm or more 4.2
%Met. For these measurements, a Coulter Counter PCA II manufactured by Coulter Electric was used.

Note that the grooves on the surface of the developing roller are usually 5° to 8° with respect to the moving direction of the developing roller surface (direction perpendicular to the rotational axis).
It has an angle of 5 degrees, more preferably an angle of 30 degrees to 60 degrees. A high slope (5°) not only reduces the cleaning effect but also reduces toner transportability. Further, in the case of a low slope (>85°), although the conveyance property is improved, the cleaning effect is reduced as described above.

It is preferable that the diameter is approximately 0.1 μm or more and not more than the average particle size of the toner used.

If the depth of the groove is greater than or equal to the average particle size of the toner, the probability of contact with the regulating member will decrease, and not only will a single layer of unevenly charged toner be formed, but the toner stuck in the groove will be used for a long time. At this time, the toner fuses and sticks, which is undesirable because it causes agglomerated toner to form on the surface of the developing roller. Furthermore, if the width of the groove is 0.1 μm or less, the desired cleaning effect will not be sufficient and the toner transportability will also be reduced, which is not preferable.

The width of iM is at least 1 of the average particle size of the toner used.
It is preferably at least /2, and more preferably at least the maximum particle size of the toner used. If the width of the groove is less than or equal to the average particle diameter of the toner, it is not preferable because the toner tends to become clogged with >19 particles, which becomes a nucleus and leads to the generation of agglomerated toner.

Furthermore, the grooves formed on the developing roller may be continuous, such as an I or two or more spiral grooves, or may be a large number of discontinuous grooves. In these cases, Mizoyama (f mark V, 1
It does not have to be 1,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000 that the age, 6,000,000,000,000,000 that was, it was not necessary that the age was 100,000 yen.

To form such grooves on a toner carrier such as a developing roller, belt grinding, sandblasting, metalloiding, thread cutting, or the like is used, for example.

Further, the toner carrier does not need to have a cylindrical shape unless it is restricted from a practical standpoint, and may have a belt shape, for example.

Further, as the material of the regulation blade, any of magnetic metal materials such as spring steel plates, non-magnetic metal materials such as stainless steel plates and phosphor bronze plates, plastic materials, and elastic rubber materials are preferably used. The support may also be fixed to the casing, especially if an elastic material is used.

Comparative example! The same evaluation as in Example 1 was conducted using a toner carrier (A120-L) whose surface had been subjected to surface blasting (5 μx RZ) and had no grooves. During printing durability tests, toner agglomeration occurred on the blade pressure contact surface, and toner adhered to the sleeve surface in a so-called filming pattern, resulting in band-like streaks and unevenness in actual photo evaluation, which was a practical problem. It was understood that it would happen. Further, during the test, the image density of the solid black area was 0.8 to 1.0, and a decrease in image density due to poor developer conveyance performance was observed, which was found to be undesirable.

As described above, according to the device of the present invention, toner fusion and adhesion on the blade pressure contact surface, as well as adhered paper powder and dust, are automatically removed, so that the toner on the developing roller is automatically removed. This eliminates streaks in the thin layer of charged toner and improves image quality. Further, since the toner is prevented from fusing and sticking on the pressure contact surface of the blade, it is also possible to prevent the toner from fusing and sticking on the developing roller. Furthermore, the toner transportability is also improved.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a specific example of the developing device of the present invention, and FIG. 2 is a schematic diagram showing the state of the grooves on the surface of the developing roller.
FIGS. 3a and 3a are perspective views showing uniform layer thickness regulation and layer thickness regulation with toner stuck to the blade, respectively; FIGS. 4a and 4s are perspective views showing the apparatus of the present invention and FIG. 3 is a schematic diagram showing the movement of toner in a friction area in a conventional device. The main symbols in the figure are as follows. l: Developing device, 2: Developing roller, 4: Regulation blade, 5
: Layer thickness regulating member, 10: Groove.

Claims (1)

[Claims] (1) A non-magnetic film having a toner carrier having a moving surface that carries toner, and a layer thickness regulating member that rubs the toner supplied onto the toner carrier to charge the toner and regulate the layer thickness. 1. A component toner developing device, characterized in that a toner carrier is provided with grooves on its surface that are inclined with respect to the direction of movement of the toner carrier.