JPS5866976A - Developing device - Google Patents

Abstract

PURPOSE:To permit the flow of a toner in a sleeve direction and to prevent the toner from scattering by constituting a projection having a return surface on the toner guiding surface below a developing vessel so as to provide a prescribed angle in the direction of the sleeve thereto. CONSTITUTION:A projection 9 having a return surface is provided near the lower outlet 5 of a developing vessel and the spacing l between a sleeve 3 and the projection 9 is set slightly wider than the spacing between a blade 7 and the sleeve 3. If the angle between the extension line C of the tangent on the return surface of the projection, and the tangent D on the inside surface of the vessel at the point P at which said extension line and the extension of the inside surface of the developing vessel below the sleeve on said extension are intersected, is defined as alpha, and if the alpha is set rougly at <=110 deg., the scattering of the toner can be prevented. The flow of the toner collides against the projecting part 9 as shown by an arrow B and its moving direction is turned over to the sleeve direction in the swirling state, therefore, the sticking on the sleeve and the scattering to the outside are prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a developing device E1m using a one-component magnetic toner in an image forming apparatus such as an electrostatic copying machine.

Generally the conventional current 1#! The shape of the developer carrier is 11.
As in one layer, the fA image dispensing container 1 toner guide direction 1a is composed of madanet p-tsu 2 and sleeve 5 m11I# carrier 4
It is wrapped in a semicircular shape. When using a two-component developer, the sleeve 6 is initially covered with a thick layer of iron powder called a carrier, so toner scattering is caused by the gap 5 between the sleeve 6 and the container 1, and the lower part of the sleeve. The shape of the inner surface of the container 1aK did not have much influence. However, in recent years, with the downsizing of machines and the 4#I machine which requires seven maintenance systems, a developing device using -component magnetic toner has been used. Although the sleeve has a relatively large diameter (φ40 or more), the semicircular portion 11 inside the developer container that encloses the sleeve can be made relatively long, so no problems have been raised. However, since the layer of toner attached to the small diameter league of φ20 or less is thin, it is possible to use up the developer toner in the am container until it is completely empty, and when replenishing the toner in the bag, The toner is scattered and blown out from the lower sleeve outlet 5), which has the disadvantage of staining the photoreceptor 6 and the inside of the photoreceptor near this outlet, which not only affects the stability of the image but also causes mechanical troubles due to the scattered toner. Ta.

SUMMARY OF THE INVENTION An object of the present invention is to provide a developing device which eliminates the drawbacks caused by the scattered toner, is inexpensive, has good image stability, and improves the maintenance-free nature of the 1III image forming device.

This invention provides a developing device using -component developer,
A protrusion having a curved surface is provided near the end of the developer container in the upper direction t of the developer carrier, so that the developer carrier and the protrusion are 0.
It has a gap of 5IIll to 1.5-, and the angle a between the extension line of the contact edge on the burr surface of the protrusion and the tangent inward to the container at the intersection on the extension of the inner surface of the developer container below the current 1H agent carrier is approximately This is a current salary device that is designed to be less than 110f.

The gLSS device 1 includes a magnet 2. The doctor blade 7 and the like are fixed, and the sleeve 5 rotates around the magnet roller 2 as shown by the arrow 41. The sensory body 6 that is close to it also rotates in the direction of the arrow. Magnetism in the developer container) + - aax leaf 'Thin and uniform on the sleeve with the doctor blade 7 as it rotates 50 times =
The layer thickness of the toner is limited to one layer, and the toner is transported to a development position facing the photoreceptor 6 and subjected to development. A projection 9 is provided on the circular surface of the container near the lower outlet 5 of the sleeve 6.
Since the gap between the blade L and the sleeve 6 is set slightly wider than the gap between the blade L and the sleeve 6, the toner that has not transferred to the photoreceptor returns to the developer container without being obstructed by the protrusion 9, and the new toner is deposited in a layer. are formed and moved sequentially over the sleeve.

In this way, when the toner is sequentially consumed every ms and a specified layer of toner cannot be formed, new toner must be replenished. Figure #g6 is an enlarged cutaway view of the lower position of the sleeve. When adding toner at the beginning and during the process,
There is hardly any toner on the lower toner guide surface 10 of the image carrier container, and when toner is put in, the toner slides in the guide direction 1o and gradually fills the container. At this time, in the case of the conventional example shown in Fig. 1, if a protrusion (burr) is not formed near the end of the developer container and the end of the container is formed into a smooth extension, the exit from the sleeve Even if you narrow the gap, the toner will still blow out with the wind flow. As shown in Fig. 3 of the present invention, a protrusion 9 having a curved surface is provided in the vicinity of the lower outlet 5 of the current salary container.As mentioned above, the gap l between the sleeve 3 and the protrusion 9 is The gap is set slightly wider than the gap between the In other words, a gap! is set to 0.5M or more, which is thicker than the thickness of the toner layer on the sleeve of 0.1 to 0.6, and is set to 1.5 mm or less because if l is too large, the toner will scatter from this gap. 1lli of the inward direction of the container at the intersection point PK of the tangent extension line C on the protrusion return surface and the extension of the inner surface of the developing container below the sleeve.
Assuming that the angle with D is α, experiments have shown that when α is approximately 110f or less, toner scattering prevention can be achieved extremely well. With this structure, when toner is put in, the toner flow collides with the protrusion 9 as shown by arrow B, and the direction of movement of the toner is changed toward the sleeve, creating a vortex, and the toner adheres to the sleeve. Improved flying fist.

FIG. 4 is a cross-sectional view showing another embodiment of the present invention, and the position of the protrusion (burr) 9 is set at 41 on one of the magnet rollers 2.
1k N Move it to the position just below the point. This allows the toner to be more strongly attracted onto the sleeve, thereby reducing toner scattering.

FIG. 5 is a sectional view showing still another embodiment of the present invention, in which a regulating fitting 11 is attached to the tip of the lower outlet of the existing container 1 to form a protrusion, and is attached to the existing container 2 with a screw or the like. This is a sectional view of another embodiment of the present invention in which a gap between the sleeve 6 and the protrusion 11 is integrally provided according to this embodiment in which the sleeve 6 and the protrusion 11 are provided.

As described above, in the present invention, in the vicinity of the lower outlet of the sleeve of the developer container, a protrusion having a curved surface slightly wider than the gap between the sleeve and the blade in the lower toner guiding direction of the developer container is formed at a predetermined angle in the direction of the sleeve with respect to the guide surface. Since it is constructed in a similar manner, the toner flows in the sleeve direction KtI, which is very effective in preventing the toner from scattering from the lower outlet of the container, and the cost is almost the same as conventional products.

[Brief explanation of the drawing]

FIG. 1 is a schematic sectional view of a conventional developing device, FIG. 2 is a schematic sectional view of a developing gI device according to the present invention, FIG. 6 is a partially enlarged sectional view of the device shown in FIG. 2, and FIGS. 4 to 6 are FIG. 3 is a sectional view showing another embodiment of the present invention. In the figure, 1...Developer container, 2...Magnetic roller, 311@11111+sleeve, 5@
@11@@Gap Seki, 6...Photoreceptor, 7...Doctor blade, 8...Magnetic toner, 9.11.
---Represents a protrusion. Applicant Canon Co., Ltd. Copia Co., Ltd. 1 Kasumio? sword

Claims (1)

[Claims] In a developing device using a one-component developer, a protrusion having a curved surface is provided near the end of the developer container at a position below the developer carrier, and the developer carrier and the protrusion have a diameter of 0.5 to 1.5.
It has a gap of (2), and its v at the intersection of the long line of the tangent to the burr image of the protrusion and the inner length of the developer container below the developer carrier! The angle a with the inward tangent 1 of the F device is approximately 11
The IA statue is 41 years old and has been heated to below 0 degrees.