JPH041782A - Toner screening device - Google Patents

Abstract

PURPOSE:To allow the removal of toners having poor characteristics by generating an electric field in the direction perpendicular to the direction of air flow in a housing and capturing the electrostatically charged toner particles deflected by this electric field. CONSTITUTION:The toners are deflected in the direction perpendicular (direction of the electric field) to the central axis of a toner introducing pipe 2 by the electric field E formed by electrodes 13a, 13b and the displacement of this deflection direction is the function of the size and charge of the toner particles. Since the electrostatic charge quantity of the toner particles is proportional to the toner displacement x, a toner separating means 16 is provided in the position equiv. to a certain electrostatic charge quantity and the sepn. of the toner particles by the electrostatic charge quantity bordering at this value is possible. The sepn. and removal of the low electrostatic charge toner and reverse electrostatic charge toner which are the cause for the internal fogging of the toner particles are possible. The electrostatic characteristics of the toner are thus stabilized and the good output images are obtd.

Description

[Detailed Description of the Invention] [Summary] Toner sorting device f that sorts toner according to its electrostatic properties
In order to provide a toner sorting device capable of removing toner with poor characteristics, the present invention includes a toner supply means for separating charged toner particles into individual particles and supplying the charged toner particles into a housing,
means for generating an air flow in the direction and direction of the air flow; means for generating an electric field within the housing in a direction perpendicular to the direction of the air flow; and means for generating charged toner particles deflected by the electric field within the housing. A means for collecting charged toner particles deflected by an electric field and a means for moving only charged toner particles within a predetermined range of the same amount toward the collecting means. .

[Industrial application field]

The present invention relates to a toner sorting device that selects toner based on its electrostatic properties.

In the electrophotographic method used in laser printers and the like, the characteristics of toner, which is a developing agent that converts an electrostatic latent image, is one of the most important parameters that affect the quality of the image.

[Conventional technology]

Conventionally, toners have been sorted based on their particle size (atmosphere classification) + workability, but individual toners have not been sorted based on their electrostatic characteristics. Regarding the electrostatic properties of toner, the overall physical properties were determined by evaluating samples for each toner production loft.

[Problem to be solved by the invention]

Therefore, since toners with poor characteristics are not separated and removed from the manufactured toners, some toners with poor characteristics are included even in the toners determined to be good by sample evaluation. This defective toner with poor characteristics may cause fogging, etc., and may cause IiiigI & deterioration. Furthermore, the proportion of defective toners differs depending on the manufacturing loft, and the quality is not stable between manufacturing lofts.

SUMMARY OF THE INVENTION In view of the above-mentioned conventional problems, it is an object of the present invention to provide a toner tracing device capable of removing toner having poor characteristics.

[Lesson l [Means for solving]

Figure wJ1 is a diagram explaining the principle of the present invention. In the figure, 1 is a toner supply means, which supplies charged toner;
Reference numeral 2 denotes a toner introduction path, which introduces the charged toner from the toner supply section into the nousing, 8 the charged toner, 9 the nousing, 13a.

Reference numeral 13b is an electrode constituting a deflection means that creates an electric field; 16 is a separation means that allows addition of only charged toner within a predetermined amount of deflection depending on the amount of charge; 18 is an electrode that creates an electric field; The good toner 19 is a toner with a poor charge amount.

Further, 15 is a toner collecting means, which is a means for collecting only the toner 18 having a good charge amount.

[For production]

In the present invention, as shown in FIG. 1, the charged toner 8 is separated into individual parts in the toner supply section 1, guided up the toner introduction path 2 into the inside of the nozzle 9, and carried downward by the air flow. Electric field E formed by electrodes 13a and 13b
Therefore, the toner is deflected in a direction perpendicular to the central axis of the toner introduction tube 2 (the direction of the electric field).

This displacement in the deflection direction is a function of the size and charge of the toner particles. Literature (R, B, Lewis et al.: A
CHARGE 5PECTROGRAPH FORXE
R-OGRAPHICTONER', Journal of the Electrophotography Society
Vol. 22, No. 1, p. 85 (1983)) According to K, the electric field YE.

The distance from the tip of the toner introduction path 2 to the collection filter 15 casing is expressed by the air flow velocity Va,) the toner displacement χ.

When the toner particle diameter is d, the amount of charge held by the toner particle is given by: where η is the viscosity of air.

Since the amount of charge on toner particles (5K) is proportional to the toner displacement 2, by providing the toner separation means 16 at a position equivalent to a certain amount of charge, the amount of charge -m
By separating and removing low-charge toner and oppositely-charged toner, which are the cause of toner particle separation due to K, the electrostatic properties of the toner become stable and a good output image can be obtained.
[Implementation row] Fig. 2 is a block diagram of an embodiment of the present invention, in which the same parts as the first cause are designated with (engineering and engineering) numbers. In the figure, 1 is a toner supply section, 2 is a toner introduction path through which toner particles are introduced into the housing.

FIG. 3 is a diagram showing the configuration of the toner supply section.

The toner supply section 1 includes a developing roller 3 as a developer holding means.
I'm begging. The developing roller 3 has a magnet roller 3aY inside and a sleeve 3b outside.

4 is a developer to be sorted, which is a mixture of carrier 4a, which is a magnetic particle, and toner 4b, which is a particle to be sorted. The toner is charged by the carrier 4a and the toner 4ba). The developer 4 is held on the developer loaf 3 by the magnetic force of the magnet roller 3m. Further, the developer 4 is
The magnet is conveyed in the direction of the arrow in the figure by the rotation of the magnet, the troller 3a, the sleeve 3b, or both.

At this time, the amount of developer conveyed is regulated by the doctor blade 5.

Separation of the toner 4b from the carrier 41 is performed by blowing gas. In this embodiment, nitrogen gas is used. 6 is a blow nozzle, nitrogen is supplied through the door,
Nitrogen gas is injected from the blow nozzle 6. The toner 4b is individually separated from the carrier 4a by the injection pressure at this time. The individually separated toners 8 to be sorted are introduced into a housing 9 shown in FIG. 2 through the toner introduction path 2.

Further, in FIG. 2, reference numeral 9 denotes a housing constituting the sorting device, which has a cylindrical shape. Reference numeral 10 denotes an air intake device that generates an air flow within the housing 9. housing 9
The air flow inside is made of nylon mesh cloth 1, 1-11.
．． By passing through the linear airflow generator 12, the airflow becomes an airflow with a substantially flat flow velocity distribution and a uniform airflow direction, resulting in a downward direction Kfi in the figure.

13a and 13b are Im! for eccentricity. With electrode, housing 9
Different voltages are applied to the power supply 14 such that a charge is formed within the power supply 14.
a, 14bK are given. The toner 8 to be sorted is transported by the air i and deflected by the electric field E formed by the electrodes 13a and 13b. 15 is a toner collection container that collects the deflected toner particles. Reference numeral 16 denotes a toner separation wall, which separates the toner depending on the amount of charge of the toner.

In this device, toners 8 to be sorted are separated into individual toners in a toner supply section 1, introduced into a housing 9 through a toner introduction path, and carried downward by an air flow.

Due to the electric field EK formed by the electrodes 13a and 13b,
The toner collecting filter 17 of the toner collecting container 15 is deflected in a straight line (in the direction of the electric field) with respect to the central axis of the toner introducing pipe 2.
Adhere to the top. The toner collection container 15 is provided with a toner separation wall 6 according to the required limit of the amount of charge, and a toner separation wall 116'ft is used to separate the defective toner 19 whose charge amount is lower than the required amount of charge and the necessary toner. It is divided into good toner 18 whose charge amount is higher than the charge amount. As a result of observing defective toner 19 and good toner 18 with an electron microscope, good toner 18
were uniform in size and shape, but many of the defective toners 19 were smaller than 4 in size or had distorted shapes, and obvious differences were seen.

FIG. 4 is a diagram showing another embodiment of the present invention, which differs from FIG. 3 in that the toner collection container 15 is constructed in a bag shape. Similar effects can be obtained even with such an S configuration.

FIG. 5 is a diagram showing another embodiment of the present invention, which differs from FIG. 3 in that separation walls 16a and 16b are provided. In this way, it is possible to separate not only toner with a low charge amount but also toner with an extremely high charge amount, and it is possible to separate and use only toner with more stable charge characteristics, which further improves image characteristics. do.

In this embodiment, a developing roller is used as the developer holding means, but the developer holding means is not limited to this.
Further, the developer is not limited to a two-component developer.

Further, the shape of the toner collecting container is not limited to this, and may be any shape as long as it has the same function (2).

Although the present invention has been described above using examples, the present invention can be modified in various ways according to the gist of the present invention, and these are not excluded from the present invention.

〔Effect of the invention〕

As explained above, according to the present invention, toners with poor electrostatic properties are removed from manufactured toners, and only toners with excellent electrostatic properties are selected, thereby improving the electrostatic properties of toner production lots. In addition to eliminating variations in electrical properties, it is possible to stabilize the electrostatic properties of the toner to a high level, which greatly contributes to improving and stabilizing WIJ image quality.

[Brief explanation of drawings]

Fig. 1 is a diagram explaining the principle of the present invention, Fig. 2 is a diagram showing the configuration of one embodiment, Fig. 3 is a diagram showing the configuration of the toner supply section, Fig. 4m is a diagram showing another embodiment, and Fig. 4 is a diagram showing another embodiment. ! ! It is a figure showing an example. In the figure, l is a toner supply section, 2 is a toner introduction section, 8 is charged toner, 9 is a housing, 13a and 13b are electrodes (deflection means), 15 is a toner collection container, and 16 is a separation wall.

Claims (1)

[Claims] (1) A toner supply means for separating charged toner particles individually and supplying the charged toner particles into the housing; a means for generating an air flow with a constant direction and air flow inside the housing; and a means for generating an air flow with a constant direction and air flow inside the housing. means for generating an electric field in a direction perpendicular to the direction of the housing; means for collecting charged toner particles deflected by the electric field inside the housing; means for moving only the charged toner particles toward the collecting means.