JPH07199569A - Developing device - Google Patents

Abstract

PURPOSE:To provide a developing device capable of simplifying its assembling and saving the handling time for adjustment as well so as to reduce the cost of the assembling and adjustment and make the recycling of resources easy by inserting/pressing the shafts of developing rollers requiring an electrical connection to connect without using fixing member such as screw, because the shafts of the developing rollers are supported by using a connecting terminal plate 2 composed of a conductive elastic sheet metal effectively using an elastically deforming state. CONSTITUTION:The developing device 4 having the developing rollers 1 for developing an electrostatic latent image on an image carrier is constituted so that the shafts 1a and 1b of the developing rollers requiring the electrical connection and the connecting terminal plate 2 having the clearances of the shafts 1a and 1b of the developing rollers are provided and the connecting terminal plate 2 is connected with the shafts 1a and 1b of the developing rollers by pressing through the use of the elastically deforming state. Then, the connecting terminal plate 2 is constituted so that it is held by a side plate 5 holding the shafts 1a and 1b of the developing rollers, to fix them.

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 such as an electrophotographic copying machine, a laser beam printer and a plain paper FAX, and more particularly to a developing apparatus having a developing roller to which a bias voltage for developing is applied. is there.

[0002]

2. Description of the Related Art In an image forming apparatus utilizing an electrophotographic process, a developing device supplies toner to an electrostatic latent image formed on a photosensitive member as an image carrier to make it visible. An image is formed by transferring and fixing a visible image on a recording paper. In a conventional developing device having a developing roller for developing an electrostatic latent image on an image carrier, a conductive disc-shaped member is provided on the shaft of each developing roller, and the disc-shaped members are pressed against each other. A developing device which is attached and used as an electric conduction path for bias voltage is already known (actually
30958). In addition, a conductive member such as a leaf spring that serves as an electric conduction path for bias voltage is embedded in the insulating side plate that supports the developing roller, or screwed to make contact with the conductive shaft or bearing of the developing roller. Those arranged in such a manner are also known (JP-A-57-1).
63261 publication). However, the developing roller, which requires application of these bias voltages, is troublesome to assemble and adjust in order to maintain good conductivity, and these operations are time-consuming. Further, from the viewpoint of resource recycling, the conductive material is embedded in the insulating material or is firmly fixed with screws, so that there is a problem that it takes time to separate the materials.

[0003]

SUMMARY OF THE INVENTION In the above conventional technique,
The developing roller, which requires the application of a bias voltage, is complicated and time-consuming to assemble and adjust in order to maintain good conductivity. Further, from the viewpoint of resource recycling, the conductive material is embedded in the insulating material or is firmly fixed with screws, so that there is a problem that it takes time to separate the materials.

[0004]

SUMMARY OF THE INVENTION Therefore, the present invention is to solve such a problem. That is, the shaft of the developing roller, which requires electrical connection, is supported by an elastically deformable conductive elastic thin plate (connection terminal plate) without using fixing members such as screws, thereby simplifying assembly and adjusting. Without the hassle of
It is an object of the present invention to provide a developing device in which the cost required for assembly and adjustment is reduced and resource recycling is facilitated.

[0005]

To achieve the above object, in a developing device having a developing roller for developing an electrostatic latent image on an image bearing member, a shaft of the developing roller which requires electrical connection, A developing device having a connection terminal plate having a relief portion of the shaft of the developing roller, wherein the connection terminal plate is configured to be press-contacted and connected to the shaft of the developing roller by utilizing an elastically deformed state. The main feature of the terminal plate is that it is held by a side plate that holds the shaft of the developing roller to fix the shaft of the developing roller.

[0006]

In the developing device constructed as described above, the shaft of the developing roller is pressed and connected by the connection terminal plate having the escape portion for fitting and supporting the shaft of the developing roller, and the bending and cutting of the shaft of the developing roller is performed. Since the shaft of the developing roller can be fixed by being held by the side plate of the developing roller, the conventionally used fixing plate becomes unnecessary, and if the developing roller and the shaft of the developing roller are conductive, they are inserted and pressure-contacted. A bias voltage can be easily applied from the conductive connection terminal plate, and since the connection terminal plate is pressure-contacted as long as the elastically deformed state of the connection terminal plate continues, it is possible to always maintain a good conductive state. Further, since the connecting terminal plate can be easily attached and detached without using a tool, it is possible to provide a developing device in which the cost required for assembling and adjusting is reduced and the resources are easily recycled.

[0007]

Embodiments of the present invention will now be described with reference to the drawings. First, the configuration and operation of the developing device will be outlined with reference to FIG. The image carrier (photoreceptor drum) 6 carries an electrostatic latent image by various known means and rotates in the clockwise direction shown by the arrow. The developing device 4 includes a developing roller 1, toner agitators 11 and 12, a toner replenisher 13, and the like. Although not shown, a plurality of permanent magnets are embedded in the developing roller 1, and the toner 14 agitated by the toner agitators 11 and 12 adheres to the surface of the developing roller 1.
The developing roller 1 rotates counterclockwise as indicated by the arrow. When a bias voltage is applied to the developing roller 1, the image carrier 6
The toner 14 adheres only to the portion where the electrostatic latent image is formed and forms a developed image. The present invention provides a developing device that can easily apply a bias voltage to the developing roller 1.

FIG. 1 shows an example of a developing device 4 according to the present invention, in which toner 14 (not shown) attached to the developing roller 1 is transferred to an electrostatic latent image forming portion on the image carrier 6. FIG. 6 is a diagram showing a state in which a bias voltage is applied to the developing roller 1 in order to apply it. Although the drawing shows the case where two developing rollers are attached to the side plate 5, basically there is no difference whether the number of developing rollers is one or two or more. Development bias terminal 1 connected to a bias power source (not shown)
5 is through a conductive connection terminal plate 2 electrically connected,
A bias voltage is introduced to the shafts 1a and 1b of the conductive developing roller. The bias voltage introduced to the shafts 1a and 1b of the developing roller is easily introduced to the developing roller 1 which is also conductive through a bearing or the like (not shown).

3 to 5 show an embodiment in which the connecting terminal plate 2 is formed in a shape adapted to the purpose and attached to the shafts 1a and 1b of the developing roller, which will be described in order. FIG. 3A is a side cross-sectional view of a free shape before the connection terminal plate 2 is attached to the shafts 1a and 1b of the developing roller, which is made of a conductive elastic material such as stainless steel or phosphor bronze. Have holes 3a and 3b as escape portions 3 that escape the shafts 1a and 1b of the developing roller, the diameters of both holes are d1, and the distance of the minimum material portion between the holes is 1 (el) 1. ing. Further, the developing bias terminal 15 connected to the external bias power source is fixed to the connection terminal plate 2 with a screw.

FIG. 3B is a view in which the connection terminal plate 2 is inserted into the shafts 1a and 1b of the developing roller while being elastically deformed. In this state, the diameters of the developing roller shafts 1a and 1b are set to d2,
Let l2 be the distance between the inner sides of the axes, l1> l2, d1> d
2 is established, the connection terminal plate 2 has the developing roller shaft 1a,
Pressure contact connection is made between the 1b as shown in the figure. The fixed plate 7, which is attached to the side plate 5 with screws, has shafts 1a, 1b of the developing rollers.
Is for fixing by sandwiching the side plate 5 so as not to move. The connection terminal plate 2 can be easily attached and detached by squeezing both sides of the connection terminal plate 2 within the elastically deformable range while slightly squeezing. Also, FIG.
3C is a view of the connection terminal plate 2 from the AA plane as viewed from the arrow in FIG.
It is the figure which looked at the side. The shafts 1a and 1b of the developing roller are in contact with the insides of the holes 3a and 3b of the connection terminal plate 2 so as to rub against each other. As long as the elastically deformed state of the connection terminal plate 2 continues, the connection is made by pressure contact, and the electrical connection at this contact portion makes it possible to maintain a good electrical connection state.

The pressure contact structure shown in FIG. 3 (B) is also practically applicable, but when there is strong vibration, impact, etc., the connection terminal plate 2 is displaced and comes into contact with the shafts 1a, 1b. The condition may worsen. Also, the shaft 1 of the developing roller
It is also disadvantageous in that the fixing plate 7 is required to fix the a and the b.

FIGS. 4A and 4B are structural explanatory views of another embodiment in which this point is improved. The developing roller shafts 1a, 1 are shown in FIGS.
Both sides of the tip portion (length 13) of b are formed into a flat state by milling or the like, and the elongated holes 3d and 3e and the cut and bent portion 3c (relief portion 3) are formed so as to fit with a little margin from the thickness of the flat portion. The case where the provided connection terminal plate 2 is inserted as shown in the figure and pressure contact connection is shown. That is, the slits 3d and 3e are inserted into the biting portion 5a provided on the side plate 5 so as to fit the cut and bent portion 3c of the connection terminal plate 2, and the elongated holes 3d and 3e are provided between the shafts 1a and 1b of the developing roller as shown in FIG. As in the case of (1), the elastically deformed state is utilized to insert and press-connect. FIG. 4B is a view seen from the B direction. Developing roller shaft 1
a and 1b have hole grooves 1a 'and 1b' (not shown) into which the connection terminal plate 2 is dropped between the end portions l3,
Since the connection terminal plate 2 is dropped into the hole groove to fix the shafts 1a and 1b of the developing roller at a fixed position, FIG.
The fixing plate 7 is unnecessary.

FIG. 5A shows a groove 3 at both ends of the connection terminal plate 2.
f and 3g (forked portions) are provided, and the protrusion 5b provided on the side plate 5 and the shaft 1a of the developing roller are fitted in the grooves 3f and 3g, respectively, so that the protrusion 5b and the shaft 1a are connected. An embodiment in which the terminal plate 2 is elastically deformed and is inserted and pressure-contacted and connected is shown. FIG. 5B is a view seen from the C direction. As can be seen from the figure, this is an embodiment suitable for the case where there is one developing roller.

[0014]

In the developing device having the above-described structure, the shaft of the developing roller is pressed and connected by the connecting terminal plate having the escape portion for fitting and supporting the shaft of the developing roller, and the developing roller is cut and bent. Since the shaft of the developing roller was fixed by holding it on the side plate of the shaft of, the fixing plate used in the past became unnecessary,
If the developing roller and the shaft of the developing roller are electrically conductive, it is possible to easily apply a bias voltage from the electrically conductive connecting terminal plate that is inserted and pressure-contacted. Since it is connected, it is possible to always maintain a good conductive state. Further, since a special tool is not required for attaching and detaching the connection terminal plate and can be easily performed, it is possible to provide a developing device in which the cost required for assembly and adjustment is reduced and resource recycling is facilitated.

[Brief description of drawings]

FIG. 1 is a sectional view of a main part of a developing device showing an embodiment of the present invention.

FIG. 2 is an explanatory diagram of a main part of a general developing device.

3 (a), (b) and (c) are side views of a connection terminal plate showing an example of the present invention, an explanatory view of mounting on a shaft of a developing roller using (a), and an arrow in (b). It is explanatory drawing seen from the view AA.

FIGS. 4A and 4B are explanatory views of attachment of a developing roller to a shaft using a connection terminal plate showing another example of the present invention, and an explanatory view seen from an arrow B of FIG. 4A. is there.

5 (A) and 5 (B) are an explanatory view of attachment of a connection terminal board showing another example of the present invention, and an explanatory view seen from an arrow C of FIG. 5 (A).

[Explanation of symbols]

1 ... Developing roller, 1a ... Developing roller shaft, 2b
... Development roller shaft, 2 ... Connection terminal plate, 3 ...
Relief part 3a ... hole, 3b ... hole, 3c ... cut and bent, 3d ... oblong hole, 3e ... oblong hole, 3f ...
Groove, 3g ... Groove, 4 ... Developing device, 5 ... Side plate,
5a ... biting part, 5b ... protrusion part, 6 ... image carrier, 7 ... fixing plate, 11 ... toner agitator, 1
2 ... Toner agitator, 13 ... Toner replenisher, 14
... Toner, 15 ... Development bias terminal.

Claims (2)

[Claims] 1. A developing device having a developing roller for developing an electrostatic latent image on an image bearing member, wherein the shaft of the developing roller, which requires electrical connection, and the shaft of the developing roller are fitted and supported to conduct electricity. The developing device is characterized in that it has a connection terminal plate having an escape portion for achieving the above, and the connection terminal plate is configured to be pressed into contact with the shaft of the developing roller by utilizing its own elastically deformed state. 2. The developing device according to claim 1, wherein the connection terminal plate is held by a side plate holding a shaft of the developing roller to fix the shaft of the developing roller.