JPS6235093Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a developing container for a copying machine that uses a dry developer consisting of two components: toner and carrier.

In this type of developing container, a developing sleeve and a pumping sleeve are rotatably arranged, and both have a plurality of permanent magnets arranged therein. The developing sleeve is placed close to the photoreceptor drum, and the spikes of developer formed on the developer sleeve come into contact with the surface of the photoreceptor drum on which the electrostatic latent image is formed, thereby making the electrostatic latent image visible. . After the development is completed, the developer on the developing sleeve is scraped off and reaches the bottom of the developing container, and is again supplied to the developing sleeve by the pumping sleeve together with new toner that is replenished as needed. In this case, large toner particles and dust that have weak adhesion to the carrier constituting the developer tend to accumulate at the bottom of the developer container, but because the distance between the pumping sleeve and the bottom wall of the developer container is small, the pumping sleeve is Large-sized particles such as toner and dust are pumped up again and supplied to the developing sleeve. If these large-sized toner particles or dust adhere to the image area of the photoreceptor, they will lift the transfer paper from the photoreceptor surface when being transferred to the transfer paper, thereby interfering with the normal transfer of the surrounding toner and reducing the image quality of the copy. Significantly decreased.
Furthermore, since the developer constantly rubs against the wall surface of the developer container, the temperature of the developer and developer container increases, resulting in accelerated deterioration of the developer.

The object of the invention is to eliminate the above-mentioned drawbacks in developing containers of the first type.
Embodiments of the present invention will be described below with reference to the accompanying drawings.

In FIG. 1, a developing container 2 is arranged below a photosensitive drum 1, a developing sleeve 3 is located close to the surface of the photosensitive drum 1, and a developing sleeve and a developing sleeve 3 are located below the developing sleeve 3. A pumping sleeve 4 serving as a developer conveying member is rotatably mounted adjacent to the bottom of the developer container 2 . An appropriate number of permanent magnets 5 and 6 are fixedly arranged inside the developing sleeve 3 and the pumping sleeve 4 in close proximity to the inner surface of each sleeve, so that the pumping sleeve 4 captures the developer on its surface. This is then supplied to the developing sleeve 3. The developer supplied to the developing sleeve 3 forms spikes that come into contact with the surface of the photosensitive drum 1, and the electrostatic latent image formed thereon is made visible by toner. After the development is completed, the developer is scraped off by the scraper 12 and falls to the bottom of the developer container.

The toner in the toner storage tank 7 is supplied by a control wheel 8 into the developer container 2 in a fixed amount, and after development is mixed with the developer that reaches the bottom of the developer container. The developer supplied with new toner reaches the pumping sleeve 4, and is again supplied to the developing sleeve 3 by the pumping sleeve.

A recess 9 is provided at the bottom of the developer container in the lower range of the pumping sleeve 4 as a developer conveyance path.
The recess 9 is recessed with a step from the bottom of the adjacent container, and is provided with partition plates 10 arranged at appropriate intervals laterally with respect to the direction of flow of the developer. This stepped recess 9 is also shown in FIG. Only this recessed portion 9 is made removable from the bottom of the container, thereby making it possible to take out the large particle diameter toner, dust, etc. that have accumulated here. Examples are shown in FIGS. 3 and 4. Each of the recesses 9' and 9'' can be attached to and removed from the bottom of the container by sliding perpendicularly to the plane of the paper.

The distance between the lower surface of the pumping sleeve 4 and the bottom surface of the recess 9 is set so that the developer on the surface of the pumping sleeve does not rub the bottom surface of the recess, and the carrier that has fallen to the bottom surface is returned to the pumping sleeve 4 by the magnet inside. It is preferable that the magnet 6 is attracted by the magnet 6, and therefore, the value depends on the size of the magnet 6, magnetic flux density, etc., but it is preferably about 7 mm to 15 mm. After falling into the recess 9, large-sized toner particles, dirt, etc. that have weak adhesion to the carrier are not attracted to the pumping sleeve and remain there. In that case, the partition plate 10
However, it prevents these large particle size toners, dust, etc. from moving to a position where they are likely to be drawn up by wind, vibration, etc. When the partition plate 10 is not provided, the recess 9 is made to have a step, and this step performs the same function as the partition plate. In addition, in order to prevent the large particle size toner accumulated in the recess 9 from being drawn up by the electric field, the recess 9 is
It is preferable that the conductor is made to have the same potential as the pumping sleeve 4, or a potential that generates an electric field such that the toner receives a force directed toward the inner surface of the recess. By making the partition plate 10 also a conductor and having the same potential as the recessed portion, the above-mentioned function can be promoted.

In the embodiment shown in FIG. 5, a net 11 made of a conductor is provided between the recess 9 and the developer flow, and by making this net equipotential with the wall surface of the recess, the above-mentioned electric field effect can be promoted. I can do it. Of course, the size of the mesh is large enough to allow at least large particle size toner and dust to pass through.

According to the present invention, by configuring the developer container of a copying machine as described above, particles such as large particle diameter toner and dust that have a relatively weak adhesion to the carrier are captured in the recesses, and are prevented from being pumped up again. It can be done.

[Brief explanation of the drawing]

Figure 1 is a sectional view of the developing container according to the present invention;
The figure is a perspective view of the main part, FIGS. 3 and 4 are cross-sectional views showing modified examples of the recess, and FIG. 5 is a cross-sectional view showing another embodiment of the present invention. 2... Developing container, 4... Pumping sleeve, 9...
Recessed part, 10... Shikiri board.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) In a developing container of a copying machine that uses a dry developer consisting of two components, toner and carrier, and is equipped with a developer conveying member that conveys the developer under magnetic action. , a recess is provided below the developer transport member and located in the developer transport path, and the recess is arranged as follows with respect to the developer transport member, that is, the developer on the surface of the developer transport member is 1. A developer container characterized in that the developer container is arranged so that the carrier does not rub the bottom surface of the recess and the carrier that has fallen onto the bottom surface of the recess is captured again by the developer conveying member under its magnetic action. (2) The developer container according to claim 1, wherein the recessed portion is recessed with a difference in level from the adjacent developer container. (3) The developer container according to claim 1 or 2 of the utility model registration claim, characterized in that a recess is provided at the bottom of the developer container. (4) The recess is located horizontally to the flow of developer.
The developer container according to any one of claims 1 to 3, which is characterized by being provided with one or more partition plates. (5) Utility model registration claims 1 to 4, characterized in that the recess is a conductor and has a potential that is equal to that of the developer pumping member or that generates an electric field that applies a force to the toner toward the inner surface of the recess. A developing container according to one of the items. (6) Registration of a utility model characterized in that the recess and the partition plate are conductors, and these conductors have a potential that is equal to the developer pumping member or that generates an electric field that applies a force to the toner toward the inner surface of the recess. A developer container according to claim 4. (7) The developer container according to any one of claims 1 to 6 of the utility model registration claim, characterized in that the recessed portion is removable from the developer container.