JPS6126065A - Developing device of nonmagnetic one-component developer - Google Patents

Abstract

PURPOSE:To resolve the density ununiformity of development of copies by providing an uniforming member at an angle to a developer carrier. CONSTITUTION:A developer 1 in a hopper 2 is supplied onto an elastic body 4b of an uniforming member 4 by the gravity and is triboelectrified by rubbing between the member 4 and a developer carrier 5 to have a charge and is sent to the carrier 5, and a thin developer layer having a prescribed thickness is formed on the carrier 5 by the first blade 31, and the developer is triboelectrified between the blade 31 and the carrier 5 also to have a charge. Thus, the charge is sufficiently given to the developer layer. The carrier 5 is rotated while applying the bias voltage to the carrier 5 to send this developer layer to an electrostatic latent image holding body 7, and the developer is flown toward an electrostatic latent image 6 and is stuck to the latent image 6, and it is developed to a visible image. The carrier 5 and the member 4 are attached at an angle relatively, and it is necessary that the angle of inclination is <=5 deg., and the good result is attained if it is set to 1-2 deg. desirably.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method for converting an electrostatic latent image formed on an electrostatic latent image carrier into a visible image using a non-uniform component developer in an electrophotographic apparatus. This relates to a non-magnetic component developing device.

Conventional technology JP-A-17-13088 and JP-A-53-167
341, etc., non-magnetic component development in which a developer is sent to an electrostatic latent image holder by a developer carrier and the electrostatic latent image on the holder is developed into a visible image. The device is known.

In such a non-magnetic component developing device, when reproducing an original image such as a low-density original or text original on an electrostatic latent image holder, it is not necessary to consume a large amount of developer at once. Therefore, uniform development is always performed, a constant visible image is obtained, and a constant IC copy image quality is always obtained.

However, when reproducing an extremely dense and wide-area solid black original (that is, a high f1 degree, wide-area solid black image) on an electrostatic latent image holder, a large amount of developer is consumed at once. As a result, there is an insufficient supply of developer, and it is not possible to develop a uniform visible image of the melon, making it impossible to obtain a copy image with uniform density. In other words, the reproducibility of high-density, wide-area solid black images is poor.

Particularly, when the length of the solid black image is longer than the circumference of the electrostatic latent image carrier, insufficient supply of developer becomes evident, and a 1-iJ visual image with uniform density cannot be obtained.

As a countermeasure against this problem, before a thin layer of developer is formed on the developer carrier by the regulating member, a uniformizing member supplies the developer to the developer carrier and collects the remaining developer from the carrier. It is publicly known that the

Problems to be Solved by the Invention The equalizing member is made of urethane rubber [1]
- The elastic member in the shape of a roller is pressed against the developer carrier E] - the developer [coal, but depending on the amount of pressure applied, the developer [1]] and the homogenizing member may bend, and as a result, the developer [coal] The width of pressure contact between the coal and the equalizing member changes in the axial direction, and the movement of the developer from the equalizing member to the developing roll is uneven in the axial height. It was the cause.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a non-magnetic-component developing device which overcomes the drawbacks of the prior art described above and achieves uniform transfer of developer from the homogenizing member to the developer roll.

Means for Solving the Problems According to the present invention, a developer carrier, a non-magnetic component developer is supplied to the developer carrier, and a portion of the residual developer on the developer carrier is recovered. The electrostatic latent image on the electrostatic latent image holding member is visualized by providing a uniforming member for holding the developer and a regulating member that comes into contact with the developer carrying member to form a WJE of the developer on the developer carrying member. There is provided a non-magnetic component developing device, characterized in that the developer carrier and the homogenizing member are attached to the non-magnetic component developing device in pressure contact with each other in an oblique positional relationship. Ru.

By providing the equalizing member at an angle C with respect to the developer carrier, the above-mentioned problems of the prior art are solved. The inclination angle is 15 degrees or less, preferably 1 to 2 degrees.

Operation: Since the equalizing members are arranged in a series at an angle with respect to the developer carrier, the pressure contact width between the equalizing member and the developer carrier becomes substantially constant in the axial direction. As a result, the equalizing member can supply a constant amount of developer to the developer carrier without variation in the axial direction.

Embodiments Hereinafter, embodiments embodying the present invention will be described with reference to the drawings.

FIG. 1 is an explanatory diagram of a non-VA component developing device, in which below a hopper 2 in which developer 1 is stored, a developer carrier 5 carrying developer 1 and a homogenizing member 4 are mutually connected. Pressed against the
The first blade 3 is in contact with the developer carrier 5 and the second blade 32 is in contact with the equalizing member 4, so that the electrostatic latent image 6 is held facing the developer carrier 5. An electrostatic latent image holder 7 is rotatably provided, and a bias voltage superimposed with one self-current voltage is applied to the developer carrier 5 from a bias power supply 8.

The developer 1 is a non-magnetic component type developer, in which a polarity control agent such as a gradient such as carbon or a metal-containing azo dye is dispersed in various thermoplastic resins such as styrene resin or acrylic resin.
It is made into a size of -C5 to 20μ by crushing and classification, and in some cases, in order to improve the fluidity, it is added in the range of 0.5 to 2.0 parts by weight per developer particle. Hydrophobic silica may also be added.

The first blade 31 is brought into pressure contact with the stainless steel plate C1 developer carrier 5 of a predetermined thickness with a predetermined contact pressure, thereby forming a thin layer of the developer 1 of a predetermined thickness on the developer carrier 5. In addition to serving as a regulating member, the second blade 32 also controls the developer 1.
I came into contact with the equalization department on April 4th with contact pressure so strong that it did not spill out.

The equalizing member 4 has a cylindrical shape in which an elastic body 4b made of urethane rubber or the like is adhered to a metal core 48, and is pressed against the surface of the developer carrier 5 at a predetermined pressure. The developer carrier 5 is composed of, for example, a stainless steel roll.

Therefore, the developer 1 in the hopper 2 is evenly distributed due to gravity.
The developer is supplied to the elastic body 4'b-1- of the uniformizing member 4, and is triboelectrically charged by the friction between the uniformizing member 4 and the developer holding body, and then sent to the developer carrier 5. A thin developing layer with a predetermined thickness is formed on the developer carrier 5 by the first blade 31, and a C lightning charge is also generated by frictional charging between the first blade 31 and the developer carrier 5. Given. For this reason, the developer layer becomes sufficiently charged.

This developer layer is sent to the electrostatic latent image holder 7 by rotating the developer carrier 5 while applying a bias voltage to the developer carrier 5, and the electrostatic latent image 6 and the developer carrier The electrostatic latent image 6 is caused to fly toward the electrostatic latent image 6 due to the electric field between the electrostatic latent image 6 and the electrostatic latent image 6, where it is deposited and developed into a visible image.

In this way, the friction between the equalizing member 4 and the developer carrier 5 and the friction between the developer carrier 5 and the first blade 31 occur. Since the developer is distributed in the friction zone by PI rubbing and is given an electric charge, a sufficient electric charge is given to the developer, and the developer that did not contribute to development is placed on the developer carrier 5 without being immobilized. Some of this residual developer is removed by the uniformizing member 4.
The developer 1 is supplied by the equalizing member 4 to the area where the developer is collected and where no developer exists, and after being corrected to a more or less uniform state, the developer 1 enters the hopper 2 and is again collected at a predetermined level by the first blade 31. A developer layer of varying thickness is formed.

While the equalizing member has the above-mentioned advantages, it has an elastic structure, so if it is brought into contact with the developer carrier 5 with too strong a pressure, both sides will bend, making it impossible to maintain uniformity in the axial direction. It becomes difficult to form a developer layer. Here, factors contributing to layer formation in the axial direction include layer formation on the uniforming member 4 by the second blade 32, and layer formation from the uniforming member 4 to the developer carrier 5.
Three factors can be considered: the efficiency of developer transfer to the developer carrier 5 and the formation of a layer on the developer carrier 5 by the first blade 31. Among these, the uniformity member 4 made of an elastic body adopted in the present invention is considered.
Let us consider the movement of the developer at the portion where it is pressed against the developer carrier 5. Referring to FIG. 2, this figure shows the pressure contact width in FIG. 1 and the transfer efficiency of the developer from the uniformizing member 4 to the developer carrier 5. The developer itself is frictionally charged for the first time by the equalizing member 4 and the second blade 32 43. If the developer n1 after passing through the second blade is 100, the culm increases as the pressing width l increases. It can be seen that the developer transfer efficiency increases. However, in order to increase the pressing width, if a material with a constant elastic modulus is used, it is necessary to press with a stronger pressing force, and the deflection of the two wooden rolls will also increase. This phenomenon becomes more pronounced as the copy size becomes larger and the equalizing member 4 and developer carrier 5 become longer in the axial direction. To illustrate this schematically, when the two 1-rules are bent, the axial pressure width becomes uneven as shown in Figure 3.
The pressure welding width is relatively narrower at the center than at both ends. As a result, the developer transfer efficiency is lower at the center than at both ends, resulting in a lower density when the electrostatic latent image 6 on the electrostatic latent image holder 7 is developed.

The present inventor has conducted various experiments to solve the uneven development at the center and both ends of a developed IC image, and as a result has arrived at the present invention. I was able to eliminate the unevenness. That is, as shown in FIG.
The uneven press-contact width shown in FIG. 3 became approximately uniform as shown in FIG. 4, and the above-mentioned problems could be solved. It is clear that the inclination between the developer carrying member [L] and the equalizing member U is too large and is not suitable for the movement of the developer. Good results were obtained with a very slight tilt of 1 to 2 degrees.

On the other hand, when the equalizing member 4 is partially pressed against the developer carrier 5, the pressure width increases and the amount of developer movement increases as shown in FIG.
- Due to the deflection of the rail, the non-uniformity of the pressure welding width becomes worse.

In this case, by increasing the inclination angle described in III as the amount of pressing increases, a desired approximately uniform pressure-welding width can be obtained. In this case, although the bearings of both rolls are not shown, since the axis of the developer carrier 5 normally needs to be kept parallel to the axis of the electrostatic latent image carrier 7, the homogenizing member 4 The developer carrier 5 is constructed by tilting the sides by the required angle and attaching the bearings at both ends to the side plates of the housing (not shown) at the same angle; however, the developer carrier 5 may be tilted if there is no problem with the development characteristics. ,.

Specific examples of the developing device of the present invention will be described below. The equalizing member 4 is pressed against the carrier 5 with a force of 3' Ky f.At this time, the elastic modulus of the elastic body 4b is E = 2.
Kgf/ctM', the outer diameter of the equalizing member 4 is 15 m, the diameter of the shaft core 4a is 8 #, and the outer diameter of the developer carrier 5 is 20 m.
11111, the surface roughness Ra=1 μm, and a stainless steel roll was used. 9-ized member 4 is developer carrier 5
However, the situation was such that it seemed to sink in about 1m. As shown in Figure 3, when both the wheels are in an untwisted state, I
= 3 m, and the pressure contact width is only about 60% due to IN against HAX, and as a result, the transfer rate of the developer from the homogenizing member 4 to the developer carrier 5 in this area is also relatively reduced. However, there was a decrease in density in the center of the copy. On the other hand, according to the present invention, both [! -If the curve is tilted as shown in Fig. 5, then, for example, the slope will be about 2 degrees CΣt! (By doing this, the pressure welding width will become as shown in Figure 4,] 818M)
-4,! J mm, so over the entire axial direction,
The developer was moved approximately uniformly, and the density unevenness described above was eliminated.

Effects of the Invention According to the present invention, by arranging the equalizing member at an angle with respect to the developer carrier, it is possible to make the pressure contact width between the equalizing member and the developer carrier approximately constant in the axial direction. As a result, it is possible to eliminate uneven development density in copies.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram of the developing device of the present invention, FIG. 2 is a graph showing the relationship between the width of pressure contact between the developer carrier Ll-roll and the equalizing member roll and the developer transfer efficiency, and FIG. FIG. 4 is a schematic diagram showing the generally uniform pressure contact shape of both rolls in the axial direction. FIG. FIG. 3 is a schematic perspective view showing the attachment relationship with the converting member roll. 1: Developer 2: Small brim 3: First blade 32: Second blade 4: Uniformizing member,
5: Developer carrier 1: Electrostatic latent image carrier Applicant: Fujize [] Acting for Tsukusu Co., Ltd., A:
Patent Attorney Ko Matsumoto - Figure 2 Atsushi Shin

Claims (2)

[Claims] (1) A developer carrier, a homogenizing member that supplies a non-magnetic one-component developer to the developer carrier and recovers a portion of the residual developer on the developer carrier, and the developer carrier A non-magnetic one-component developing device for visualizing an electrostatic latent image on an electrostatic latent image holder by providing a regulating member that contacts the developer to form a thin layer of developer on the developer carrier. A non-magnetic one-component developing device, characterized in that the agent carrier and the homogenizing member are mounted in pressure contact with each other in an oblique positional relationship. (2) The axis of the developer carrier is installed on the same plane and parallel to the axis of the electrostatic latent image holder, and the equalizing member is installed obliquely with respect to the developer carrier. 2. The non-magnetic one-component developing device according to claim 1, wherein the non-magnetic one-component developing device is mounted in pressure contact.