JPS63205681A - Developing device - Google Patents

Abstract

PURPOSE:To exhibit a uniform development characteristic over the entire length of a developer carrying body by providing a means for controlling the rate of supplying the developer to supply the developer uniformly over the entire length of a 1st hopper to said hopper from a developer supplying means. CONSTITUTION:The magnetic developer is thinly and uniformly coated by a magnetic blade 15 on the developer carrying body 10 contg. a stationary magnet and is conveyed to the position opposite to a latent image carrying body 1 where the developer is used for the development of the latent image. Supplying of the developer to the developer carrying body 10 is executed by a developer agitating means 13 in the 1st hopper 9. The developer 12 supplied by the 2nd hopper 11 to the front side end of the developer supplying means 16 is conveyed to the deep side by the rotation of the means 16 and is uniformly supplied beyond the wall 17 for controlling the supplying rate of the developer successively into the 1st hopper 9 over the entire length thereof. The supplying of the developer 12 is controlled by a developer amt. detecting sensor 18 provided on the deep side. The mixing and agitating of the fresh and old developers are thereby uniformly executed without causing the insufficient or excessive supply of the developer. The developing characteristic uniform in the longitudinal direction of the developer carrying body is thus obtd.

Description

[Detailed description of the invention] A1 Objective of the invention [Field of industrial application] + J)! i 111 1-) tM j I
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The present invention relates to a Tfl image device, and particularly to a developing device that conveys a developer coated on the surface of a developer carrier to a position facing the latent image carrier to develop a latent image on the surface of the latent image carrier.

[Conventional technology]

Recently, the demand for color copies has increased rapidly not only in specialized fields but also in offices and general households. Color copying devices, which are now popular in number, have a plurality of color developers each having a plurality of color developers around a Wi image carrier 1, as shown in FIG. In figure 0, which is a type with developing devices 2a and 2b,
3 is a primary charger, 4 is an image exposure system, and 5 is a copy paper conveyance guide.

6 is a transfer charger, 7 is a separation charger, and 8 is a cleaner consisting of a roller 8a and a blade 8b.

In such a color copying apparatus, it is essential to downsize the developing device in order to downsize the apparatus. Therefore, since the capacity of the developer storage section in the developing device, that is, the first hopper, is inevitably limited, there are cases where 1υ developer is loaded into the first hopper with 4# chains and 2 strips. many.

[Problem that the invention seeks to solve]

However, as shown in FIG. 5, when there is little free space around the latent image carrier l, the second hopper is placed at either end of the first hopper in the longitudinal direction (usually for convenient replenishment of developer, etc.). It is installed at the front end).

FIG. 6 is a diagram of a conventional developing device viewed from the side of the latent image carrier, in which the first hopper 9 is longer than the developer carrier 10 and extends in the direction tjfH, and the first hopper 9 is located above the extending portion 9a. 2
A hopper 11 is provided, and the developer 1 is supplied to the extending portion 9a.
2 is supplied. Developer 1 supplied to stretching section 9a
2 is stirred and conveyed by a stirring rod 13 in the first hopper to a portion facing the developer carrier.

In this way, it seems that the developer is made uniform in the longitudinal direction of the first hopper and uniform development characteristics are obtained in the longitudinal direction of the developer carrier, but experiments have shown that this is not actually the case. It became clear.

That is, while the unused developer 12 supplied from the second hopper it is easily coated on the developer carrier on the developer supply side 4j, the unused developer 12 on the opposite side is coated on the developer carrier -E and developed. developer that is difficult to develop, or
Due to sufficient agitation, a large amount of developer has poor fluidity, resulting in differences in development characteristics in the longitudinal direction of the developer carrier.
It was found that the uniformity of the image could not be maintained.

In addition, when copying documents that consume a large amount of developer in succession, it takes time for the developer supplied from one developer supply end to be conveyed to the other end, so the developer supply cannot keep up. There were problems such as images not being displayed.

The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a small and inexpensive developing device that exhibits uniform developing characteristics over the entire length of a developer carrier.

1. Structure of the Invention [Means for Solving the Problems] The present invention provides for transporting a developer coated on the surface of a developer carrier to a position facing the latent image carrier, thereby improving the surface of the latent image carrier. In a developing device that develops a latent image.

a first hopper that supplies developer to the developer carrier;
A developer supply means for supplying the developer to the first hopper, a second hopper for supplying the developer to one end of the developer supply means, and a developer supplying means for stirring the developer in the first hopper so that the developer is mixed with the developer. A developing device comprising: an agitation conveyance means for conveying the developer to the first hopper; and a developer supply amount control means for uniformly supplying the developer from the developer supply means to the first hopper over its entire length. It is.

[For production]

In the developing device of the present invention, uniform development characteristics can be obtained in the longitudinal direction of the developer carrier by the developer supply amount control means,
Stable, high-quality images are always obtained.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, 14 is a developer container in which a first hopper 9 is formed, and a developer carrier 10 is provided opposite to the Wf image carrier. 15 is a blade that controls the amount of developer conveyed by the developer carrier 10;

Reference numeral 16 denotes a developer supplying means such as a screw, one end of which extends longer than the first hopper 9 toward the front as shown in FIG. 2, and a second hopper 11 is provided above the extended portion. ing. Reference numeral 17 denotes a wall as a developer supply amount control means provided between the first hopper 9 and the developer supply means 16, and this wall 17 is gradually lowered from the second hopper 11 side to the other end side. .

Next, the operation will be explained. A magnetic developer is coated thinly and uniformly on the developer carrier 10-h containing a fixed magnet with a magnetic blade 15, and is conveyed to a position facing the Wi image carrier l to develop a latent image. Served. The developer is supplied to the developer carrier lO by the rotation of the developer stirring means 13 in the first hopper 9.
3 also functions to make the developer in the first hopper 9 uniform in the longitudinal direction.

The developer is supplied to the first hopper 9 through a developer supply amount control wall 17 by a developer supply means 16 such as a screw.

That is, the developer 12 supplied to the front end of the developer supply means 16 by the second hopper 11 is conveyed to the back side by the rotation of the developer supply means 16, and is sequentially passed over the developer supply amount control cap 17. It is uniformly fed into the first hopper 9 over its entire length.

Further, the supply of the developer 12 is controlled by a developer amount detection sensor 18 provided on the back side of the first hopper 9.

As the developer amount detection sensor 18, for example, a piezoelectric element, an inductance detection element, or the like is used.

FIG. 3 shows a vertical cross-sectional view of the vicinity of the developer supply means.
At the same time as the developer is supplied from the developer supply means 16 to the developer supply means 16, the developer supply means 16 rotates, and the developer 12 is conveyed along the developer supply amount control wall 17 from the developer supply port side to the opposite side. Ru.

Here, since the developer supply amount control wall 17 is configured such that the height decreases from the developer supply port side toward the opposite side (back side), the developer supply amount control wall 17 is configured such that the height decreases from the developer supply port side to the first hopper 9. It is difficult for the developer to fall, and it becomes easier to fall as you move toward the back.

However, since the developer is transported to the back side while falling into the first hopper 9 one after another from the developer supply port side, the amount of developer transported is substantially reduced on the back side. Therefore, in order to compensate for this decrease in conveyance amount, the developer supply amount control wall 17 is lowered, and it has been confirmed that the amount of developer supplied to the first hopper 9 is almost uniform in the longitudinal direction. Ta. Further, the developer in the first hopper 9 is mixed and stirred by a developer stirring means 13, and the amount of developer in the longitudinal direction is made uniform.

Note that the shape of the developer supply amount control means is not limited to the wall 17 having an inclination in the longitudinal direction;
The figure shows another embodiment of the developer supply amount control means, in which the height of the wall 17 is constant, but holes 19 are formed whose diameters gradually increase from the front side to the back side. Furthermore, the outer diameter or pitch of the screw serving as the developer supply means 16 may be changed.

C. Effects of the Invention As described above, according to the present invention, uniform development is carried out over the entire length of the first hopper between the first hopper that supplies the developer to the developer carrier and the developer supply means. Since the structure is provided with a developer supply amount control means for supplying the developer, there is no shortage or oversupply of developer, and the mixing and agitation of old and new developer is performed uniformly, and the length of the developer carrier is This has the effect that uniform development characteristics can be obtained in the direction, and stabilization of high quality images can be achieved.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a developing device showing an embodiment of the present invention;
Fig. 2 is a front view thereof, Fig. 3 is a vertical sectional view thereof, Fig. 4 is a front view showing the developer supply amount control wall, Fig. 5 is a sectional view of the vicinity of the latent image carrier, and Fig. 6 is a conventional FIG. 3 is a front view of the developing device of FIG. 1...Wi image carrier, 9...1st hopper, 10...
...Developer carrier, 11...Second hopper, 13...
- Stirring means, 16...Developer supply means, 17...Developer supply? Control wall, 18...Developer amount detection means.

Claims (1)

[Claims] (1) In a developing device that develops a latent image on the surface of the latent image carrier by conveying the developer applied to the surface of the developer carrier to a position facing the latent image carrier, the developer is developed on the developer carrier. a first hopper that supplies developer, a developer supply means that supplies developer to this first hopper, a second hopper that supplies developer to one end of this developer supply means, and a developer in the first hopper. an agitation conveyance means for stirring and conveying the developer to the developer carrier; and a developer supply amount control means for uniformly supplying the developer from the developer supply means to the first hopper over its entire length. A developing device characterized by comprising: