JPS60120368A - Single-component nonmagnetic developer - Google Patents

Abstract

PURPOSE:To allow a single-component magnetic developer which is used for the developing device of an electrophotographic copying machine to enter the gap between a developing roll and a regulating blade excellently and form a uniform layer by setting the angle of repose of the developer within a prescribed range. CONSTITUTION:The developing roll 15 has no ruggedness on the surface and is rotated by a driving system as shown by an arrow and also applied with a developing bias from a bias power source 16. A blade 17 as a regulating member for forming a toner layer is set in a wiper direction for the developing roll 15. The blade 17 is made of a metallic plate made of stainless steel having, for example, 0.1mm. plate thickness. The linear pressure of the blade 17 is 1-500g/cm and the developer regulated by the blade 17 to fixed thickness reaches a photosensitive body 11 to develop an electrostatic latent image 19 formed on the surface of the photosensitive body 11.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a component-based non-magnetic developer used in a developing device of an electronic copying machine.

PRIOR ART Conventional electronic copying machines have widely used developing methods such as cascade developing method and magnetic brush developing method, but since they both use co-component type developing agents, they have the following disadvantages. . In other words, when using co-component developing agents, the surface of the carrier becomes contaminated with the toner composition and the chargeability of the carrier is impaired during long-term use. In addition to the need to change the toner mixing ratio, the photoreceptor may be damaged by the carrier, and the present agent must be replaced periodically, making maintenance cumbersome. In order to improve these problems, a developing method using a special toner/component magnetic developer containing magnetic powder with relatively low resistance has recently been proposed, but this method causes high-temperature dark transfer defects. There are drawbacks such as the inability to obtain clear color copies.

In order to improve these drawbacks, a developing method using a developer using a non-magnetic toner having high resistance has also been proposed. This developing method is carried out as follows using, for example, the developing apparatus shown in FIG. 1 of the accompanying drawings. That is, the photoconductor 1 is placed in a hopper 2 installed near the photoconductor 1.
A developing roll 3 is provided adjacent to the developing roll 3, and a developing bias is applied to the developing roll 3 by a power source 4. Further, a component developer 5 made of non-magnetic toner is stored in the hopper 2, and is carried to the photoreceptor 1 side as the developing roll rotates 30 times, and an electrostatic latent image 6 formed on the surface of the photoreceptor 10 is formed on the surface of the photoreceptor 10. It is designed to be developed.

In this process, it is important to form a thin layer of toner with a uniform thickness on the developing roll 3. For this purpose, a regulating member is used to uniformly regulate the thickness of the developer that adheres to the surface of the developing roll 3. A toner further regulating blade 7 is used as a toner regulating blade 7. However, even if such a regulating blade 7 is used, the ability of the developer toner to penetrate between the blade 7 and the developing roll 3 may deteriorate, or the toner layer formed on the developing roll 3 may become uneven. Developing roll 3
Problems have arisen in that the history of where the toner has been developed remains on the copy, and this is printed out on the copy. Here, the history phenomenon on the developing roll 3 is a difference in the thickness of the toner on the developing roll 3 and the amount of toner charge between the areas where the toner has been developed and the areas where the toner has not been developed.

OBJECTS OF THE INVENTION It is an object of the present invention to solve the problems of the prior art as described above, to improve the penetration between the developing roll and the regulation blade, and to prevent the problem of uneven toner layer formation and history. An object of the present invention is to provide a component-based non-magnetic developer that can be dissolved.

Structure of the Invention According to the present invention, an electronic copying apparatus is provided that includes a developing roll and a regulating blade that uniformly regulates the thickness of the developer adhering to the surface of the developing roll, for electrostatic latent images formed on the surface of a photoreceptor. In the component-based non-magnetic developer used in the machine's developing device,
By setting the angle of repose within the range of 70'' to 3!0, it is possible to improve the penetration between the developing roll and the regulating blade, to form a uniform layer, and to eliminate hysteresis.

Embodiments Next, the present invention will be described in more detail with reference to embodiments of the present invention based on FIGS. 2, 3, and 4 of the accompanying drawings.

FIG. 1 schematically shows a configuration example of a developing device of an electronic copying machine using the developer of the present invention. As shown in FIG. 1, in this developing device, a developing device main body 12 is installed near a photoreceptor 11. The main body 12 has an opening 13A on the side of the photoconductor 11 and has a tach arm 13, and a component-based non-magnetic developer 14 is accommodated in the hopper 13. A developing roll 15, a portion of which protrudes toward the photoreceptor 11 from the opening 13A, is accommodated therein. The developing roll 15 has an uneven surface, is rotated in the direction of the arrow by a drive system (not shown), and is subjected to development/?? by a bias power supply 16. Ias is applied. Further, a blade 17 as a regulating member for forming one layer of toner is set on the developing roll 15 in one direction of the wiper.

In this example, the blade 17 is formed of a metal plate having a thickness of 0.7 m and made of stainless steel.

The linear pressure of the blade 17 is 5ooy from /Fi/crrL.
It may be within the range of 7 degrees, but in this example, it is 100 Fi/cr.
The linear pressure is rL. The developer regulated to a constant thickness by the blade 17 reaches the photoreceptor 11 and develops an electrostatic latent image 19 formed on the surface of the photoreceptor 11.

In order to investigate the relationship between the fluidity of the developer used in a developing device using such a component-based non-magnetic developer, that is, the relationship between the angle of repose and the history, developers with various angles of repose were prepared and used as described above. We evaluated the image quality characteristics of copies obtained using such a developing device.

First, is there car in styrene-acrylic resin? 10-30μm binding 30
It is placed in hot air at 0°C for spheroidizing treatment, and then fine silica powder is added as an external additive at θ, /~/θ to reduce the angle of repose g0~
Various 4.3-' developers were prepared. When 10% of the external additive was added, the angle of repose became go, and when 0.7% was added, the angle of repose became 0.

The manuscript used for the evaluation of image quality characteristics was as shown in Figure 3. As shown in FIG. 3, this document has a black image on the left with a diagonal lined image density on white packed ground, with A indicating the leading edge and B indicating the trailing edge. The length of the L dimension of the image is the length of the developing roll 1.
The length corresponds to 5 rotations.

When we make various copies using such originals and developers with various angles of repose, and summarize the relationship between the angle of repose of the developer and the copy history, we get the results shown in Figure 1. was gotten. Here, the copy history is expressed by the following equation.

In the above formula, the area developed in the developing roll/rotation corresponds to the image part of the document shown by C in FIG. 3, and the area not developed in the developing roll/rotation corresponds to the area in FIG. This corresponds to the image portion of the document indicated by D. Optimal copying is obtained when the history value expressed by the above equation is /, θ.

As is clear from the graph in Figure 1, the angle of repose of the developer is 100~. ? ! In the case of r0, a copy with a uniform layer of toner on the developing roll and no history was obtained. still,
When the angle of repose of the developer is less than 10°, the fluidity of the toner becomes too good, making it impossible to form a uniform layer of toner on the developing roll 15, resulting in uneven density.

Therefore, according to the present invention, it is preferable to use a component-based non-magnetic developer having an angle of repose in the range of 10o to 330 for the above-mentioned developing device.

The component-based nonmagnetic developer of the present invention having an angle of repose within the range of 100 to 3S0 can be easily manufactured in 1 cell by adjusting the particle size distribution of the toner, adding external additives, spheroidizing treatment, etc. - For example, if the toner is a styrene-acrylic resin with about 10% carden black added, the particle size can be reduced to /! by pulverization and classification. By sharply aligning the distribution in the range of -20 μm, a toner with an angle of repose of 2S0 can be obtained. Further, when the average particle diameter is about 10 μm, it is desirable to add external additives and spheroidize the particles. As external additives, silica, alumina, titanium oxide, etc. with a secondary particle diameter of about 200 mμ are used, and the toner has θ,
By mixing with a high speed stirrer, an angle of repose of /S to 330 can be obtained. Furthermore, in the case of 1 in which the fluidity is increased, a method of making the toner particles spherical can be taken. Dispersing toner particles in a hot air stream at θ0 to 600°C,
A spherical toner can be easily obtained due to its own surface tension. In this case, a toner having an angle of repose of 75° or less can be obtained by adding 1c simultaneously with the addition of external additives.

Effects of the Invention According to the component-based non-magnetic developer of the present invention, the toner is easily trapped between the developing roll and the regulating blade, and a uniform layer of toner can be formed, eliminating historical development, so that the toner is always uniform and beautiful. You can get a copy.

[Brief explanation of the drawing]

Figure 1 of the accompanying drawings is a schematic diagram showing an example of a conventional developing device, Figure 1 is a schematic diagram showing an example of the configuration of a developing device using the developer of the present invention, and Figure 3 is used for evaluating image quality characteristics. The figure showing the original that has been prepared is a figure showing the relationship between the angle of repose of the developer and the history. 11...Photoreceptor, 12...River...
Developing device main body, 13.4 times hot/4% 13A.Curved opening, 14.../component non-magnetic developer, 15......current (JJO- Le, 16
...... Source of bias, 17...
...Blade, 19... Electrostatic latent image

Claims (1)

[Claims] Components used in a developing device of an electronic copying machine equipped with a developing roll and a regulating blade that uniformly regulates the thickness of the developer adhering to the surface of the developing roll, using an electrostatic latent image formed on the surface of a photoreceptor. A non-magnetic developer with an angle of repose of 1
A component-based non-magnetic developer characterized in that the content thereof is within the range of 0" to 3s0.