JPH0321074B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention produces an electric field of substantially uniform strength and an air flow of substantially uniform velocity flowing through the electric field in an internal chamber of a housing, and The present invention relates to a toner particle charge distribution measuring device for introducing toner particles into a toner particle and measuring the charge distribution of the toner particles.

(Prior Art) FIG. 1 is a block diagram showing the main parts of this type of device. In the figure, reference numeral 1 denotes a suction pipe, which is a glass tube with a constricted middle portion, and whose inner surface is coated with tin oxide, which is grounded. An annular air filter material 2 is disposed around the opening of the suction pipe 1 so that air can flow into the suction pipe 1 from the surrounding area. The air filter material 2 is for forming an air layer coaxially surrounding the toner particles (sample) entering the suction pipe 1 in the direction of the arrow.
It exhibits appropriate air resistance against the air from the compressed air inflow path 15, and is porous to remove dust and the like.
Moreover, the area around the hole is a conductive member. 3 is a nylon filter for introducing the main air flow into the internal chamber 5 of the housing 4;
After that, it passes through a nylon mesh screen 6, a honeycomb-shaped straight air flow generator 7, and nylon filters 8 and 9, with a substantially flat flow velocity distribution and a suction pipe 1.
The air flows downward in FIG. 1 at approximately the same flow velocity as the air flowing out from the air. Reference numeral 10 denotes a side wall electrode for deflection, which is made of a large number of approximately rectangular tin oxide coated on the glass wall surface of the housing 4. Different voltages are applied to the side wall electrodes 10 so that a uniform electric field is formed within the interior chamber 5 of the housing 4. Reference numeral 11 denotes a grid-like bottom electrode having air permeability, which is composed of electrical wires arranged at approximately equal intervals and nylon wires arranged at approximately equal intervals in a direction perpendicular to the electrical wires. This creates a smooth potential gradient so as not to distort the particle pattern attached thereto. The resistance to the bottom electrode 11 is provided by coating one edge of the grid with a slurry of colloidal graphite and molybdenum disulfide.
It is formed by creating a coated resistor with an end-to-end resistance value of, for example, 20 MΩ. This bottom electrode 1
1 is supported by a glass frit filter 14 attached to a base 13.

In this device, toner particles are introduced into an internal chamber 5 of a housing 4 through a suction pipe 1 by a toner particle introducing means, and while falling, the toner particles are introduced into an electrode 10.
and 11 in a direction perpendicular to the central axis of the suction pipe 1 (the direction of the electric field), and is deposited on a filter 12 for detecting toner adhesion. The amount of displacement in the deflection direction is a function of the size and charge of the toner particles.

By the way, in the conventional device using the side wall electrode and the bottom electrode to form a uniform electric field as described above, the bottom electrode has a complicated structure, is troublesome to manufacture, and requires expensive materials. The problem is that the cost is high. Furthermore, even with a lattice structure, there is a problem in that it actually disturbs the airflow of the upstream filter.

(Objective of the Invention) The present invention was made in view of the above problems, and its object is to obtain an electrode that forms an electric field of uniform strength with a simple structure and an electrode arrangement that does not disturb airflow. There is a particular thing.

SUMMARY OF THE INVENTION The present invention achieves this object by creating an electric field of substantially uniform strength and an air flow of substantially uniform velocity flowing through the electric field in an internal chamber of a housing, and disposing toner particles in the internal chamber. In a toner particle charge distribution measuring device that measures the charge distribution of toner particles, the side wall electrode that forms the electric field of substantially uniform strength is provided not only on the upstream side but also on the downstream side of the filter that collects the toner particles. It is also characterized by the fact that it is also provided with.

(Example) Hereinafter, the present invention will be explained in detail using the drawings.

FIG. 2 is a configuration diagram showing a main part of an embodiment of the present invention. In this figure, the same parts as in FIG. 1 are given the same reference numerals. In the figure, 20 is a side wall electrode provided on the inner wall of the tube on the downstream side of the filter 12. The side wall electrode 20 is arranged in such a manner that the side wall electrode 10 on the upstream side of the filter 12 is extended to the downstream side of the filter 12. Like No. 10, it is composed of a substantially rectangular tin oxide film coated on the wall surface of the glass tube part, and the same voltage is applied. The length of this side wall electrode 20 (in the tube axis direction) is preferably selected to be 1/2 or more of the tube diameter.

With this configuration, the side wall electrodes 10 and 20
As a result of the cooperation of the above, a uniform electric field is generated even in the filter 12 portion, so the bottom electrode in the conventional device is not required, and the air flow in the vicinity of the filter 12 is no longer disturbed. This makes it possible to measure highly stacked layers. Further, since the bottom electrode is not required, the material and manufacturing process thereof are also eliminated, and the cost of the device can be reduced.

Incidentally, in the above embodiment, the side wall electrodes 10, 2
Although 0 is shown as being formed of a tin oxide film, other conductive metal films may be used, or a metal plate may be attached so as not to disturb the air flow. Further, the configuration other than the inventive portion shown in FIG. 2 is the same as that in FIG. 1, but is not necessarily limited thereto.

(Effects of the Invention) As explained above, according to the present invention, an electric field of uniform strength can be obtained with a simple electrode structure.
Furthermore, with this electrode, the air flow in the filter portion that collects toner particles is not disturbed.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a conventional toner particle charge distribution measuring device, and FIG. 2 is a block diagram showing a main part of an embodiment of the present invention. 1...Suction pipe, 2...Air filter material, 4...
... Housing, 5 ... Internal chamber, 10 ... Upstream side wall electrode, 12 ... Filter, 15 ... Compressed air inlet path, 20 ... Downstream side wall electrode.

Claims (1)

[Claims] 1. Toner particles that generate an electric field of substantially uniform strength and an air flow of substantially uniform velocity flowing through the electric field in the internal chamber of the housing, introduce toner particles into the internal chamber, and measure the charge distribution of the toner particles. charge distribution measuring device, characterized in that the side wall electrode that forms the electric field of substantially uniform strength is disposed not only on the upstream side of the filter that collects the toner particles but also on the downstream side of the filter. Distribution measuring device.