JPH0943979A - Development device - Google Patents

Abstract

(57) [Abstract] [Purpose] It also prevents the toner from scattering in the longitudinal direction of the magnet roll, prevents the magnet roll from falling out, and prevents the toner from scattering from the gap between the magnet roll and the photosensitive drum. By attaching / detaching the stopper member to / from the developing frame with one touch, a developing device which is excellent in assembling and serviceability of parts and which is inexpensive is provided. A developing device having a photosensitive drum 1, a magnet roll 4, an agitating member 5 and the like is provided, and an elastic member and a magnet roll that are in contact with the photosensitive drum and rub against each other are used as a developing frame. A stopper member 3 having a holding portion for rotatably holding with respect to 2 is detachably attached to the developing frame, and when the stopper member is attached, the stopper member 3 is provided on the downstream side of the magnet roll. A guide member that keeps a constant gap between the surface of the developer layer on the upper surface of the developing roller and the outer peripheral surface of the photosensitive drum is configured to be detachable from the developing frame.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus used in an electrophotographic recording apparatus, and more particularly to a developing apparatus.

[0002]

2. Description of the Related Art In an image forming apparatus of a conventional electrostatic transfer type electrophotographic copying machine, as shown in FIGS. 4 and 5, a magnet roll 4 is located in a developing frame opening portion 11 and is attached to the magnet roll 4. Since the attached developer is rubbed against the photosensitive drum 1 while rotating and is visualized, the developer is likely to be scattered to the outside of the developing frame 2 through the developing frame opening portion 11, causing the inside of the copying machine and the copy image to be contaminated. It was. Therefore, the developing frame opening 1 has been conventionally used.
Various configurations have been proposed in which a sliding sheet 6a and an elastic material 6b, which are in close contact with and rub against the photosensitive drum 1, are arranged around the periphery of the photosensitive drum 1. For example, the above configuration is disclosed in Japanese Examined Patent Publication No. 62-22147 and Japanese Examined Patent Publication No. 63-56981. In the conventional general developing device, in order to prevent the developer from scattering in the longitudinal direction of the magnet roll 4 as shown in FIG. 4, the end of the developing frame opening 11 on the downstream side of the development and the outer periphery of the photosensitive drum 1 are arranged. There is a configuration in which the surface gap is set to 1 mm or less, or a configuration in which a guide member 8 is provided as shown in FIG. 5 and a predetermined gap is maintained from the outer peripheral surface of the photosensitive drum 1 and fixed to the developing frame 2 with a screw or the like. . Further, as shown in FIGS. 4 and 5, in order to prevent the toner from scattering from the gap between both ends of the magnet roll 4 and the photosensitive drum 1, the sliding sheet 6a and the elastic material 6b are fixed in the developing frame opening 11. There is one in which they are interposed in a thickness and are fixed so as to be capable of sliding while closely adhering to the photosensitive drum 1. Further, as shown in FIG. 5, the guide member 8 and the magnet roll 4 have to be electrically set to the same potential as a leak preventing means near the photosensitive drum 1 and the magnet roll 4. Therefore, the terminal board 1
Some of them have a conducting member 13 for connecting the guide member 8 and the guide member 8.

[0003]

However, in the above-mentioned structure, the sliding sheet or the elastic material is used as the two-layer type seal structure directly at the opening end of the developing frame, but the photosensitive drum has an arc shape. Therefore, it is not possible to intervene with a certain thickness and it is not possible to sufficiently adhere due to wrinkles, etc. There is a problem in that fixing, peeling and sticking of the sliding sheet and the elastic material take time, and the assemblability and serviceability are extremely poor.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned conventional problems, and to provide a developing device which has a stable toner scattering preventing effect and is excellent in assembling property and serviceability.

[0005]

In order to solve the above problems, the present invention comprises a photosensitive drum and a developing device provided with a magnet roll, a stirring member and the like, and is in contact with the photosensitive drum. A stopper member integrally having an elastic member that slides while rubbing and a holding portion that rotatably holds the magnet roll with respect to the developing frame is detachably attached to the developing frame. A guide member installed so as to maintain a constant gap between the surface of the developer layer on the magnet roll and the outer peripheral surface of the photosensitive drum on the downstream side of the magnet roll during mounting can be attached to and detached from the developing frame. It is configured in.

[0006]

According to the present invention, with the above construction, the role of fixing the guide member for preventing the toner from scattering in the longitudinal direction of the magnet roll, the role of the holding portion for preventing the magnet roll from coming off, the role of the magnet roll and the photosensitive member. It is possible to attach / detach a stopper member having a constant thickness and a function of fixing the elastic material for preventing the toner from scattering from the gap between the both ends of the body drum without wrinkles, with respect to the developing frame with one touch. Furthermore, by using a conductive material for the stopper member, the conducting member that was necessary to keep the magnet roll and the guide member at the same potential is not required. Therefore, it is possible to provide the toner scattering prevention means which is excellent in the assembling property of the parts, the serviceability, and the cost.

[0007]

Embodiments of the present invention will be described below. FIG. 1 is a sectional view schematically showing a developing device and its periphery according to an embodiment of the present invention. FIG. 2 is a detailed view of a stopper member and a developing frame attaching / detaching portion according to an embodiment of the present invention. FIG. 3 is a detailed view of the guide member fixing portion, which is a view in the direction of the arrow X according to the embodiment of the present invention. The same components as those in the conventional example are designated by the same reference numerals.

In FIG. 1, a developing frame 2 carries the respective components such as 1 photosensitive drum, 3 stopper members, 4 magnet rolls, 5 stirring members, and the like.
These constitute a developing device. The developing device contains a developer 10 composed of toner and a carrier, and the mixture is agitated by an agitating member 5 and supplied to the magnet roll 4. The doctor blade 14 arranged on the upstream side of the developing position with a constant gap in the magnet roll 4 regulates the developer 10 on the magnet roll 4 to a constant layer thickness. The developer 10 supplied onto the outer peripheral surface by the rotation of the magnet roll 4 forms a spike at the developing position by a magnet having a plurality of built-in magnetic poles. The ears rub against the photoconductor drum 1 maintaining a constant gap, and the latent image is visualized.
As shown in FIG. 2, the stopper member 3 in which the movement of the magnet roll 4 is restricted by pressing the shaft portions 4a at both ends of the magnet roll 4 in the developing frame opening 11 on the side of the photoconductor drum 1 can be easily assembled. It has a claw 15 that uses elasticity of resin or the like and is fitted into the developing frame 2. Further, the stopper member 3 is a magnet roll 4
It is necessary to fix the elastic material 6b for preventing the toner from scattering from the gap between both ends of the photosensitive drum 1 with a constant thickness and without wrinkles. Therefore, the elastic material 6b is attached to the surface of the stopper member 3 facing the photosensitive drum 1, and
Of the elastic sheet 6b on the upstream side in the direction of rotation of the sliding sheet 6 is provided with a protrusion 15 having a height approximately equal to the thickness of the elastic sheet 6b.
It is configured such that a covers the elastic material 6b and the projection 15, and the tip thereof is fixed to the stopper member 3.

As shown in FIG. 2, a guide member 8 is provided on the downstream side of the developing position in a space formed between the magnet roll 4 and the photosensitive drum 1 in a substantially wedge shape. The guide member 8 is made of a non-magnetic material such as an aluminum plate, a phosphor bronze plate, or a resin material such as PET. A gap B with the surface of the photosensitive drum 1 and a gap C with the surface of the developing layer conveyed to the magnet roll 4 are set smaller than the gap A at the developing position.
Further, as shown in FIG. 3, the guide member 8 is placed on the seat surfaces 2a at both ends of the developing frame 2 to determine the positions of the magnet roll 4 and the photoconductor drum 1, and the stopper members 3 at both ends move the guide member 8 upward and sideways. Since it is fixed from two directions, it can be attached and removed with one touch. Further, by making the stopper member 3 a conductive material, conventionally, the guide member 8 and the magnet roll 4 are installed as a leak preventing means in the vicinity of the photoconductor drum 1 and the magnet roll 4 so as to have the same electric potential. The conducting member 13 that has been used is no longer necessary.

[0010]

As described above, according to the present invention, the stopper member 3 is used.
The function of fixing the guide member 8 for preventing toner scattering in the longitudinal direction of the magnet roll 4 accurately and easily and detachably by the invention, and the function of holding the shaft portion 4a for preventing the magnet roll 4 from coming off. Since the elastic material 6a for preventing toner scattering from the gap between the magnet roll 4 and the photosensitive drum 14 at both ends has a constant thickness and has a role of fixing without wrinkles at one time, the number of parts is small and the cost is small and compact. Can be configured as Further, since the stopper member 3 has the claw 15 utilizing elasticity of resin or the like and is fitted into the developing frame 2, it can be attached and detached with one touch, and a developing device excellent in assemblability and serviceability can be realized. is there.

[Brief description of drawings]

FIG. 1 is a sectional view schematically showing a developing device according to an embodiment of the present invention and its periphery.

FIG. 2 is a detailed view of a stopper member and a developing frame attaching / detaching portion according to an embodiment of the present invention.

FIG. 3 is an X-direction arrow view according to an embodiment of the present invention. Detailed view of guide member fixing part

FIG. 4 is a diagram showing an example of a conventional example.

FIG. 5 is a diagram showing an example of a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Photoconductor drum 2 Development frame 2a Seat surface 3 Stopper member 4 Magnet roll 4a Shaft part 5 Stirring member 6a Sliding sheet 6b Elastic material 7 Holding part 8 Guide member 9 Protrusion 10 Developer 11 Development frame opening 12 Terminal plate 13 Conductivity Member 14 Doctor blade 15 Claw

Claims (3)

[Claims] 1. An elastic member comprising a photosensitive drum and a developing device having a magnet roll, a stirring member and the like arranged therein, and an elastic member for slidingly rubbing the photosensitive drum while contacting the photosensitive drum, and the magnet roll as a developing frame. A stopper member integrally having a holding portion for rotatably holding it is configured to be removable from the developing frame, and at the time of mounting the stopper member, on the downstream side of the magnet roll, on the magnet roll. A developing device, wherein a guide member installed so as to maintain a constant gap between the surface of the developer layer and the outer peripheral surface of the photosensitive drum is configured to be detachable from the developing frame. 2. The elastic portion fixed to the photosensitive drum side of the stopper member is composed of two layers of an elastic material and a sheet material, and is provided on the upstream side in the rotation direction of the photosensitive drum and at the end portion of the elastic material. A protrusion having a height substantially equal to the thickness of the elastic material is provided in a direction opposite to the holding portion, the sheet material covers the elastic material and the protrusion, and is further fixed to the stopper member. The developing device according to claim 1. 3. The developing device according to claim 1, wherein the stopper member is conductive.