JPS6095462A - Image forming device - Google Patents

Abstract

PURPOSE:To maintain an image quality by providing an elastic body between a developing device and a fixed member. CONSTITUTION:A developer supply roller 32 is provided in a container 31, a doctor blade 33 is provided at the upper side of the roller 32, and a toner hopper 34 containing toner is arranged. The developing device 19 is fitted to the main body 30 of a copying machine while supported at three points. Namely, the developing device is supported by the developer supply roller 32, the lower side is supported rotatably on a support shaft 35, and the back surface side is supported as the fixed member on a stay 36. This stay 36 is fitted to the main body 30 and rotatable, and a coil spring 37 is interposed between the stay 36 and the back surface part of the developing device 19 to bring the developer supply roller 32 in contact closely with a photosensitive drum 18.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an image forming apparatus in which the mounting structure of a developing device in, for example, an electrophotographic copying machine is improved.

[Technical burden of the invention and its problems]

Conventionally, methods for attaching and fixing a developing device for image formation to the main body of an electrophotographic copying machine include fixing a part of the developing device and the main body with screws, or completely fixing the developing device with a fixing piece.
(rigid type), or by applying force from a specific direction of the developing device, which is equivalent to a complete fixing method.

However, when fixing with screws or via a fixing piece, it is troublesome to adjust the location and tightening position, and when fixing by pressing, unnecessary force is applied to the photoreceptor drum that the developing device is in close contact with. This causes deformation of the photoreceptor drum and the developing device itself. On the other hand, if the position adjustment is insufficient, there will be fluctuations in the gap between the photosensitive drum and the developing device, and the gap between the photosensitive drum and the developing device will change, making it impossible to stably supply developer, affecting the image density, and causing quality problems to be maintained. ,
- The above-mentioned influence is significant in component developers.

Furthermore, if a situation occurs that requires abnormal driving force on the developer side (due to deterioration of the developer, etc.), or if abnormal driving force is transmitted on the power side, damage to the drive system may occur. There was a risk.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned circumstances, and its purpose is to easily mount and fix the developing device in a predetermined position, and to maintain stable contact between the photoreceptor drum and the developing device at all times. In addition, it is an object of the present invention to provide an image forming apparatus in which damage to the drive system due to abnormal drive force transmission can be prevented.

[Summary of the invention]

In order to achieve the above object, the present invention provides an elastic body between a developing device and a fixing member that fixes the developing device.

[Embodiments of the invention]

The present invention will be described below with reference to an embodiment shown in FIGS. 1 to 3. In the figure, 10 is an electrophotographic copying machine,
A document table 11 of this copying machine 10 is configured to freely reciprocate in the direction of arrow X as required. This copy machine 10
A removable tray 12 is attached to the left side of the figure,
On the right side in the figure, a cassette 13 containing copy paper P and a manual feed guide member 7.9A are removably arranged. A feeding mechanism 14 for feeding the copy paper P in the cassette 13 or manual guide member 13A,
A transfer mechanism 15 that transfers the magnetic toner onto the copy paper P, a transport mechanism 16 that transports the transferred copy paper P, and a fixing mechanism 17 that fixes the magnetic toner transferred onto the copy paper P.
, a photoreceptor 18 as an electrostatic latent image forming surface such as a selenium drum, a developing device #19 for developing an electrostatic latent image formed on the surface of the photoreceptor 18 with magnetic toner, and a photoreceptor. body 1
8, a cleaning device 20 for cleaning the document table 1;
1, an illumination system 21 that illuminates the original document, a charger 22 that charges the photoreceptor 18 with the illumination system 21, a transport roller 24 that conveys the fixed copy paper P to the tray 12, and movement of the document table 11. A motor 25 and the like that periodically rotate the photoreceptor 18 are built in. Further, a cooling device 26 for cooling the heat generating section is installed on the left side in the figure.

A paper fish detector is placed above the cassette 13, and
A paper jam detector (for example, a microswitch) is provided on the left side of the fixing mechanism 17 in the drawing. In addition, 27 in the figure
28 is a static eliminator, and 29 is a charging exposure lamp.

The main body 30 of the copying machine 10 has an upper frame 30 and a lower frame 30B pivoted at one end 4, and the other ends of both frames 3oA, 3oB are opened at a desired angle (for example, 25 degrees). It is configured so that it can be done. A photoreceptor 18, a cleaning device 20, a developing device 19, a document table 11, etc. are attached to the upper frame 30A by appropriate means, and the upper unit 4JA
is configured, and a cassette 1 is installed in the lower frame 30B.
3. The transfer mechanism 15, the fixing mechanism 17, the tray 12, etc. are each attached by appropriate means to form a lower unit, and after the operation panel 22 is rotated and removed as a whole, The t-hill is configured to be able to be opened and closed in the direction of the arrow y with reference to the conveyance path of the copy paper P via a housing opening/closing device (not shown).

In the apparatus configured as described above, the document placed on the document table 1 is illuminated by the illumination system 21,
The image is formed on the surface of the photoreceptor 18. After that, the copy paper P in the cassette 13 or the manual guide member 13A is transferred to the paper feed mechanism 1.
4, the sheets are taken out one by one and guided to the lower part of the photoreceptor 18, and the developed image developed with the magnetic toner in the developing device 19 is transferred onto the sheet of paper P by the transfer mechanism 15. Here, the pre-transfer static eliminator 3 is used to increase the transfer efficiency and to improve the peelability of the copy paper P from the photoreceptor 18.

Further, the copy paper P is guided into the fixing mechanism 17 via the conveyance mechanism 16 and fixed thereon, and then discharged to the tray 12 via the conveyance rollers 24. The photoreceptor 18 after the transfer is cleaned by a static eliminator 28 and a cleaning device 20, and then positioned at 220 chargers.

Next, the developing device 19 will be described in detail with reference to FIG. In the figure, 31 is a container, and a developer supply roller 32 is provided inside this container 31. Further, a toner blade 33 is provided on the upper side of the developer supply roller 32, and a toner hopper 34 for storing toner as a developer is also provided. This developing device 19 is supported at three points and attached to the main body 30 of the copying machine. That is, it is supported by the developer supply roller 32, and the lower side is rotatably supported by the support shaft 35.
Furthermore, the back side is supported by a stay 36 as a fixing member. The stay 36 is attached to the main body 30 and is rotatable in the direction of the arrow. A coil spring 37 as an elastic body is interposed between the stay 36 and the rear surface of the developing device 19. The coil spring 37 is inserted into a recess 38 formed in the rear surface of the developing device 19 and presses and biases the developing device 19 from the rear side of the developing device 19 to force the developer supply roller onto the photosensitive drum 18. They are kept in close contact.

In this way, since the developing device 19 is supported via the coil spring 37, there is no need to take time to position the fixed part, unlike when the developing device 19 is fixed with screws. There is no risk that the photoreceptor 19 will come into pressure contact with the photoreceptor 18 and deform it, and can be easily and reliably fixed in a predetermined position.

Further, the gap between the photoreceptor 18 and the developer supply row 232 can be maintained constant, the developer can be stably supplied, and image quality will not deteriorate.

Note that the present invention is not limited to the above embodiment,
As shown in FIG. 4, a protrusion 4 may be integrally provided on the inner surface of the apparatus main body 30, and the coil spring 37 may be supported by this protrusion 41. According to this embodiment, the developing Since the attachment of the main body 30 directly supports the developing device 19 in the device process of the device 19, the number of assembly steps can be reduced.

Further, the elastic body is not limited to a coil spring, and rubber, a gas-sealing cushioning material, or a combination thereof may be used.

〔Effect of the invention〕

As explained above, since the present invention provides an elastic body between the developing device and the fixing member that fixes it, it is possible to reduce the troublesomeness of adjustment and mounting when installing the developing device, and to apply excessive pressure to the photoreceptor. It is possible to perform a stable developing process by preventing the application of excessive force, preventing incomplete contact of the developing device, and preventing deformation of the photoreceptor, and it is possible to maintain and improve image quality. Furthermore, the flexibility of the intervening elastic body is effective against abnormal driving force, and the damage prevention and maintenance safety of the driving force transmission mechanism can be improved.

[Brief explanation of drawings]

1 to 3 show an embodiment of the present invention, in which FIG. 1 shows the structure of an internal tank 9 of an electrophotographic copying machine, FIG. 2 is a side view thereof, and FIG. 3 shows a developing device. FIG. 4 is a side view showing another embodiment of the mounting structure for the developing unit. 18... Photosensitive drum, 19... Developing device, 201...
...Elastic body (spring example), 202...Fixing device (stay), 21...(Copier) exterior cover. Applicant's agent Patent attorney Takehiko Suzue 10-

Claims (3)

[Claims] (1) An image forming apparatus comprising a developing device fixed within an apparatus main body by a fixing member, characterized in that an elastic body is provided between the developing device and the fixing member. (2) The image forming apparatus according to claim 1, wherein the elastic body is a coil spring. (3) The image forming apparatus according to claim 1 or 2, wherein the fixing member is constituted by a part of the apparatus main body.