JPS63155161A - Developing device - Google Patents

Abstract

PURPOSE:To obtain a stable image of high quality which does not have any image defect such as an irregularity in density and voids by forming a gap for supplying a proper amount of developer toner to a supply roll between a partition member and the toner supply roll. CONSTITUTION:The gap 10 which is, for example, 2/3-1/3 time as large as the diameter of the toner supply roll 5 is formed between the surface of the toner supply roll 5 and the tip of the partition member 7. Part of a developer supplied by an agitator 6 from a rear housing 3 to a front housing 3a is controlled well by the partition member 7 to prevent the developer from clogging in a wedgelike shape between a developing roll 4 and a support 8, and a proper amount of developer is supplied to the toner supply roll 5 from the gap 10. Consequently, even when a solid image which is long in a process direction is developed, an irregularity in density and voids due to a deficiency of the developer are securely prevented from occurring.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a developing device for developing a WP Hirohiro image using a non-magnetic one-component developer.

[Conventional technology]

There is a developing device conventionally used in hand printing for developing an electrostatic latent image formed on the surface of an 8-layer carrier using a non-containing component developer.

For example, in the method disclosed in Japanese Patent Application Laid-Open No. 61-156167, a toner supply roll is provided behind a developing roll installed near a latent gI carrier, and a toner supply roll is provided behind the developing roll, and the developer sent out from inside the hopper by an agitator is used for developing. The electrostatic latent image formed on the surface of the latent image carrier is developed into a toner image by the developer that is supplied to the developing roll and adhered in a thin layer to the surface of the developing roll.

In addition, in the above-mentioned developing device, a partition member is provided above the toner supply roll to prevent the developer sent out by the agitator from being sufficiently mixed with the existing developer and being supplied to the development roll. This prevents the developer from being directly supplied to the developing roll, thereby achieving the effect of preventing image defects such as streaks and capri caused by insufficient charging of the developer.

[Problem that the invention seeks to solve]

However, in the conventional developing device described above, the tip of the partition member that prevents the inflow of new developer reaches near the surface of the toner supply roll, so when developing a long solid image in the process direction, the tip of the partition member that prevents the inflow of new developer reaches the surface of the toner supply roll. The amount of developer supplied may be insufficient, resulting in problems such as unevenness in p and white spots on solid images.

This invention was made for the purpose of improving the above-mentioned problems.

Means and action for solving all the cldNh points] While developing the area formed on the latent image carrier by the non-magnetic one-component developer adhered in a thin pigeon-shape on the surface of the developing roll,
Above the toner supply roll that supplies the developer to the development roll, there is a partition member made of gold film that prevents the gT developer from being directly supplied to the development roll. A developing device that prevents a shortage of developer to be supplied to the developing roll even when developing a long solid image in the process direction by providing a gap between which a sufficient amount of developer is supplied to the toner supply roll.

〔Example〕

An embodiment of the present invention will be described in detail with reference to all the drawings.

In the figure, reference numeral 1 denotes the main body of this apparatus used in a copying machine or the like, which is installed near a drum-shaped or belt-shaped support 2.

The main body 1 has a housing 3 whose surface facing the latent image carrier 2 is open.
A developing roll 4 is provided close to the surface of the latent image carrier 2, and a toner supplying roll 5 is provided behind the developing roll 4, which is rotatable in the direction of the arrow by a drive system (not shown).

The toner supply roll 5 has a core layer 5 made of urethane foam.
The surface of a, the surface? #! The developing roll 4 and the toner supply roll 5 are housed in the front housing 3a of the housing 3. The housing 3H consists of a front housing 3a and a rear urethane 3b, which are communicated with each other by an opening 3d having a weir 3C at the bottom.

Further, an agitator is provided approximately in the center of the rear housing 3b, and is rotated in the direction of the arrow by a drive system (not shown).
The non-magnetic one-component developer contained therein is supplied into the front housing 3a through the opening 3C.

On the other hand, a partition member 7 for regulating the inflow of developer is provided in an opening 3C that communicates the front housing 3a and the rear housing 3b. The partition member 7 is made of, for example, a metal thin plate, mylar sheet, polyimide sheet, etc., formed into a substantially crank shape, and the upper end 7a is formed from the front housing 3.
It is interposed between the support body 8 added to the upper part of the inner surface of the front housing 3a and the inner surface of the front housing 3a.

Further, the intermediate portion 7b of the partition member 7 extends obliquely above the toner supply roll 5 provided in the front housing 3, and the front end bent portion 7C extends from the front housing 3.
It is brought into contact with the rotating shaft 9 that passes through the circle a in the lateral direction from the opening 3C side. A gap 10 is formed between the tip of the bent portion 7C and the surface of the toner supply roll 5, for example, on the order of /3 to A of the diameter of the toner supply roll 5.

In the figure, an elastic blade scrapes off the developer supplied to the developing roll 4 by the 11#-i toner supply roll 5 and forms a thin developer layer of a constant thickness on the surface of the developing roll 4;
Reference numeral 12 denotes a lower seal that prevents the developer from leaking from the lower part of the opening 3C of the housing 8 on the image carrier 2 side.

Next, to explain the operation in conjunction with FIGS. 2 to 4, the developer accommodated in the rear housing 3h is, for example, 20
'R by the agitator 6 which is rotated at a speed of rprn.
Front part from 30 part 3C/-becomes inside the housing 3a. At this time, if the partition member 7 is not present in the opening 3C, the developer supplied into the front housing 3α will be wedged between the developer roll 4 and the support 8, as shown in FIG. becomes. If copying is continued in this state, the developer on the developing port 4 side and the newly supplied developer will not be replaced with each other, and charging failure will occur due to the charging effect of the clogged developer with each other. Resulting in.

Furthermore, in order to prevent the above-mentioned problems, if the partition member 7 is extended to the vicinity of the surface of the toner supply roll 5 as shown in FIG. In this case, density unevenness and white spots occur after the developing roll 4 rotates once or twice.

Therefore, in the embodiment of the present invention, a gap 101 is formed between the surface of the toner supply roll 5 and the tip of the partition member 7, for example, from /3 to /2 of the diameter of the toner supply roll 5.

As a result, the agitator 6 causes the rear no.
Part of the developer supplied from the inside to the front housing 3a7 is regulated by the partition member 7, resulting in the developer becoming wedge-shaped between the developing roll 4 and the support 8, as shown in FIG. Moreover, since an appropriate amount of developer is supplied to the toner supply roll 5 from the gap 10, even when developing a long solid image in the process direction, it is possible to prevent density unevenness and white spots due to lack of developer. This can definitely be prevented.

Note that the opening area of the gap 10 is set by determining the appropriate value of M based on the diameters and rotational speeds of the developing roll 4 and toner supply roll 5, the amount of developer supplied by the agitator 6, etc., and is therefore particularly limited to the above value. It's not a thing.

Furthermore, in the above embodiment, since the tip of the partition member 7 is supported by the rotation shaft 9 passing through the front housing 3a, it is possible to use the partition member 7 with low rigidity. The partition member 7 may be manufactured to have 1ki1+ properties to the extent that it will not be deformed by the pressure of the developer supplied by the agitator 6.

〔Effect of the invention〕

As described in detail above, this invention provides a gap between the partition member that restricts new developer from being directly supplied to the developing roll and the toner supply roll to supply an appropriate amount of developer to the toner supply roll. Because of this, even when developing a long solid image in the process direction, the toner supply low
There is no shortage of developer supplied from the roll to the developing roll.

This makes it possible to obtain stable, high-quality images free of image defects such as density unevenness and white spots.

[Brief explanation of the drawing]

The drawings show all embodiments of the present invention, with FIG. 1 being a sectional view and FIGS. 2 to 4 being explanatory views of the operation. 2 is a latent image carrier, 4 is a developing roll, 5 is a toner supply roll, 7 is a partition member, and 10 is a gap.

Claims (1)

[Claims] A toner supply roll that develops the electrostatic latent image formed on the latent image carrier 2 with a non-magnetic one-component developer adhered to the surface of the developing roll 4 in a thin layer, and also supplies the developer to the developing roll 4. A partition member 7 is provided above the toner supply roll 5 to prevent new developer from being directly supplied to the development roll 4, and an appropriate amount of developer is supplied between the toner supply roll 5 and the partition member 7. Gap 1 supplying to roll
A developing device characterized in that a zero is provided.