JPS6015654A - Developing device for electrophotographic copying machine - Google Patents

Abstract

PURPOSE:To enable stable conveyance of a developer irrespectively of the amt. of the developer in a hopper and to prevent clogging of a trimmer for trimming a magnetic brush by inclining the trimmer bar at Q deg. relative with the perpendicular. CONSTITUTION:A hopper 2 of a developing device is provided near a photosensitive body 1. A developing roll 3 which consists of a magnetic roll 3 rotating in an arrow direction attracts the one-component developer in the hopper 2 and forms a magnetic brush. A brush 4 is so formed that the tips thereof are trimmed by the tip of a trimmer bar 5 installed above the roll 3. The bar 5 is installed to position nearer the body 1 side than the perpendicular Y running the center O of the roll 3 and to incline at an angle Q (1-30 deg.) relative with the Y. Thus the developer scraped by the tip 5a moves smoothly toward the arrow on the back of the bar 5.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention This invention relates to a developing device for an electronic copying machine using a one-component magnetic developer.

Prior Art Conventionally, in the developing device of this type of copying machine, a trimmer bar is provided vertically near the developing roll, and the tip of the magnetic brush formed on the surface of the developing roll is trimmed with the tip of the trimmer bar. The height of the spike was kept constant. However, when the trimmer bar is installed vertically, a large amount of developer is put into the hopper.

Since the pressure of the developer increases on the multi-scratched side of the trimmer bar, problems such as poor conveyance of the developer on the surface of the developing roll and block-like developer clogging may occur in the trimmer. Ta.

Purpose of the Invention The present invention has been made with the aim of eliminating such problems, and it makes it possible to always carry stable developer regardless of the amount of developer put into the hopper, and also to prevent trimmer clogging from occurring. The purpose of the present invention is to provide a developing device for an electronic copying machine.

A developing device for an electronic copying machine in which the developer scraped by the trimmer bar flows smoothly along the back surface of the trimmer bar by tilting the trimmer bar at an angle θ with respect to the perpendicular line.

EXAMPLE Hereinafter, an example of the present invention will be described in detail with reference to the drawings. In the figure, reference numeral 1 denotes a photoreceptor of an electronic camera (not shown), and a hopper 2 of a developing device is provided near the photoreceptor 1.

The hopper 2 has an opening on the photoreceptor 1 side, and a developing roll 3 is provided in this opening 2α so as to be close to the photoreceptor I. The developing roll 3 is a magnetic roll that rotates in the direction of the arrow, and absorbs the one-component magnetic developer put into the hopper 2 to form a magnetic brush 4 on one circumferential surface. The leading end of the developing roll 3 is to be trimmed by the leading end of a trimmer 5 installed above the developing roll 3. The trimmer bar 5 is located on the photoreceptor 1 side with respect to a perpendicular line Y passing through the center O of the developing roll 3, and is installed so as to be inclined at an angle θ with respect to the perpendicular line Y. Further, the angle θ is set in a range of 1 to 30 degrees, so that the fc developer scraped off by the tip end 5α of the trimmer bar 5 is removed from the rear surface of the trimmer bar 5.

In other words, it flows smoothly along the scratched surface as shown by the arrow.

Next, to explain the experimental results, with the conventional trimmer bar installed vertically, as the amount of developer charged into the hopper 2 increases, the solid density of the copy obtained increases as shown in Figure 2 (
The amount of developer conveyed on the surface of the developing roller 3 also decreases as shown in FIG. 2(b).

On the other hand, the trimmer bar 5 is moved at an angle of 15° with respect to the perpendicular Y'.
When the hopper is tilted, regardless of the amount of developer in the hopper 2, as shown in Fig. 3 (α), the solid # is constant.
In addition, the developer conveying lid on the surface of the developing roll 3 also fell almost uniformly as shown in FIG. 3 (6).

Effects of the Invention As described in detail above, the present invention tilts the trimmer bar 5 for trimming the tip of the magnetic brush 4 formed on the surface of the VC% developing roll 3 with respect to the perpendicular line Y, thereby allowing the trimmer bar 5 to scrape off the tip. Since the developer is made to flow smoothly along the back surface of the F Limano (5), the amount of developer conveyed on the developing roll 3 is reduced regardless of the amount of developer introduced into the F Limano (2). This makes it possible to obtain copies with a constant image density, and also allows the developer to be
Since no sticking phenomenon occurs, trimmer clogging is also eliminated. Moreover, a large amount of developer can be heated at once.
Since the developer can be fed into the tank, the number of times the developer needs to be replenished is reduced, which also has the effect of making maintenance and inspection easier.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is a block diagram, FIG. 2 (α), (h), and FIG. 3 (α), (h).
is a diagram showing experimental results. 0 1 is a photoreceptor, 3 is a developing roll, 4 is a magnetic brush, and 5 is a trimmer bar. Person Masaaki Yonehara, Patent Attorney, Fuji Xerox Co., Ltd. Figure 1 Figure 2 (a) Figure 2 (b) Amount of developer in the hopper (9) @ 3 Figure (0) @ 3 Figure (b) Inside the hopper Developer) Kan9)

Claims (2)

[Claims] (1) Electronic copying in which the magnetic brush 4 formed on the surface of the developing roll 30 for developing the photoreceptor 1 is trimmed by a trimmer bar 5, in which the trimmer bar 5 is tilted at an angle of 0 with respect to the perpendicular Y. The developing device of the machine. (2) A developing device for an electronic copying machine according to claim 1, wherein the inclination angle θ of the trimmer 5 is set in a range of 1 to 30 degrees.