JP3793370B2 - Blade support structure, developing blade structure, and developing device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a developing blade structure in which a developing blade is in contact with or close to a developing roller, and more particularly to a developing device in which a developing blade is in contact with or close to a developing roller.
[0002]
[Prior art]
It has a developing device that supplies toner to the surface of the latent image carrier on which the latent image is formed to visualize the latent image, and this visualized image is formed into a sheet form such as paper by this developing device. Conventionally, an image forming apparatus configured to transfer to a transfer material is known.
[0003]
As the developing device, for example, a developer composed of toner and a carrier housed inside is supplied to the surface of the latent image carrier by a developer carrier having a built-in magnet rotatably supported in the housing of the developing device. Those that visualize the latent image formed on the surface of the latent image carrier are widely put into practical use.
[0004]
In the developing device, in order to regulate the amount of the developer adsorbed on the surface of the developer carrier, the developer carrier is disposed in the axial direction with a predetermined distance from the surface of the developer carrier, A developing blade fixed to a part of the developing device housing is provided. The distance between the surface of the developer carrying member and the developing blade must be set to a tight tolerance in order to make the amount of developer supplied to the latent image carrying member uniform in the axial direction of the developer carrying member.
[0005]
Therefore, the conventional developing apparatus employs a developing system in which the developing blade 2 is brought into contact with the developing roller 1 as shown in FIG. In this conventional developing device, in the developing blade 2 in which the blade 3 is fastened to the holder 4 with several screws 5, the screws are fastened with a constant torque such as the conventional fastening torque indicated by the dotted line in FIG. 4.
[Problems to be solved by the invention]
However, as indicated by the dotted line in FIG. 5, the straightness S2 of the conventional blade is large and is about 0.1.
For this reason, as shown in FIG. 3, the conventional developing device has a problem that the gap between the developing roller and the blade is non-uniform and in a large contact state, and a good frictional charge cannot be obtained, resulting in an abnormal image. .
In order to make this gap uniform and small, there is a method of increasing the applied pressure F in FIG. 1, but this has the problem of scratching the developing roller and shortening the service life.
[0006]
Then, an object of this invention is to provide the braid | blade support structure which can hold | maintain a braid | blade in flat form.
[0007]
In addition, the present invention can hold the blade in a flat plate shape and can make a contact state in which the gap between the rotating body and the blade is small and constant without increasing the pressure applied from the blade to the rotating body. An object of the present invention is to provide a developing blade structure capable of obtaining a triboelectric charge.
[0008]
In addition, the present invention can hold the blade in a flat plate shape and can make a contact state in which the gap between the rotating body and the blade is small and constant without increasing the pressure applied from the blade to the rotating body. An object of the present invention is to provide a developing device that can obtain a triboelectric charge.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, a first aspect of the present invention is a blade support structure in which a thin blade is fastened to and supported by a holder means at a number of locations, and the tightening torque between the blade and the holder means is directed from both ends toward the center. The blade support structure is characterized by being gradually reduced in size. With this configuration, it is possible to obtain a blade support structure with greatly improved straightness.
[0010]
According to a second aspect of the present invention, in the developing blade structure in which the developing blade is in contact with or close to the developing roller, the developing blade is arranged in line contact or in close proximity to the peripheral surface of the developing roller in parallel with the axis of the developing roller And a holder means for fastening and attaching the blade at a number of locations in the axial direction, and the fastening torque between the blade and the holder means is gradually reduced from both axial ends toward the center. A developing blade structure. In this configuration, since the straightness of the developing blade is greatly improved, the contact gap between the developing roller and the blade is small and uniform, and a developing blade structure that can obtain good frictional charging can be provided.
[0011]
According to a third aspect of the present invention, a latent image is formed on the surface of the latent image carrier so as to be rotatable. The developer is supplied to the latent image carrier to make the latent image visible. And a developing blade for making the amount of the developer adhering to the surface of the developer carrying member uniform, the developing blade is in line contact with the surface of the developer carrying member. Or a blade disposed in the vicinity and holder means for fastening and attaching the blade at a number of locations, and the tightening torque between the blade and the holder means is gradually reduced from both ends of the blade toward the center. Device. In this configuration, since the straightness of the developing blade is greatly improved, the contact gap between the developing roller and the blade becomes small and uniform, and a developing device capable of obtaining good frictional charging can be provided.
[0012]
According to a fourth aspect of the present invention, in the developing device according to the second aspect, the tightening torques at both ends of the blade are of the same magnitude.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
2A and 2B show a developing blade used in the developing device of one embodiment of the present invention, in which FIG. 2A is a front view of the developing blade, FIG. 2B is a side view thereof, and FIG.
[0014]
As shown in FIG. 2, the developing blade according to the embodiment of the present invention includes a blade 3, a holder 4, a number of screws 5 for fastening and fixing the blade 3 and the holder 4, and in this embodiment, seven screws. 5.
[0015]
The blade 3 is a thin spring material, and is made of stainless steel (SUS301-CSP-3 / 4H (JIS)) in this embodiment. The material of the blade 3 can be appropriately selected depending on the magnetic transmittance, the spring constant, and the like. The blade 3 is a rectangular thin plate having a length of 351 mm, a width of 24 mm, and a thickness of 0.15 mm. Seven holes in the present embodiment are formed at equal intervals along one long side. Yes.
[0016]
The holder 4 has an L-shaped cross section, and is made of a zinc-treated steel plate (SECC-C-E16 (JIS)) in this embodiment. The developed dimensions of the holder 4 are a length of 351 mm, a width of 20 mm, a thickness of 2 mm, and a bending height of 5 mm, and seven holes through which the screws 5 are passed are formed at equal intervals in this embodiment.
[0017]
In the present embodiment, the screw 5 is an M3 × 4 screw, and includes seven screws 5a, 5b, 5c, 5d, 5e, 5f, and 5g.
[0018]
The blade 3 is fastened to the holder 4 with screws 5. As shown by the solid line in FIG. 4, the screw tightening torque at that time is reduced as it goes from both ends to the center. For example, in the present embodiment, the screw tightening torque of the screw 5a and the screw 5g is 0.80 (Nm), the screw tightening torque of the screw 5b and the screw 5f is 0.70 (Nm), and the screw The screw tightening torque of 5c and the screw 5e was 0.65 (Nm), and the screw tightening torque of the screw 5d was 0.63 (Nm). Thus, the torque curve is symmetrical on both sides with the center screw 5d as the center.
[0019]
The order of tightening the screws 5 is preferably alternately tightened from the outside toward the center, such as the screws 5a, 5g, 5b, 5f, 5c, 5e, and 5d.
[0020]
As described above, when the blade 3 and the holder 4 are tightened with several screws, the blade 3 of the developing blade 2 that has been tightened with the torque distribution as shown in FIG. 4 is straight as shown by the solid line in FIG. S1 is 0.015, which is a significant improvement over the case where the straightness S1 of the conventional product is 0.1. Therefore, according to the developing device using the developing blade 2 of the present invention, the contact gap d between the developing roller and the blade in FIG. 3 is small and uniform, and good frictional charging is obtained. In addition, the measurement direction of the blade straightness in FIG. 5 is the same as the pressing direction in FIG.
[0021]
In the above embodiment, the number of screws 5 that fasten the blade 3 and the holder 4 is seven. However, the number of screws may be three or more, and is appropriately determined according to the length of the blade. That is, in this specification, the term “large number” means 3 or more.
Further, the developing blade may be arranged in line contact with or close to the developing roller.
[0022]
The present invention is not limited to the above embodiment. That is, various modifications can be made without departing from the scope of the present invention.
[0023]
【The invention's effect】
As is apparent from the above description, according to the present invention, the straightness of the blade supported and supported can be greatly improved.
Further, since the straightness of the developing blade is greatly improved, the contact gap between the developing roller and the blade becomes small and uniform, and an effect of obtaining good frictional charging is obtained.
[Brief description of the drawings]
FIG. 1 is a schematic diagram illustrating a main part of a developing device.
2A is a front view of a developing blade, FIG. 2B is a side view thereof, and FIG. 2C is a bottom view thereof.
FIG. 3 is a diagram illustrating a gap state caused by contact between a developing roller and a blade.
FIG. 4 is a diagram illustrating a relationship between a screw position and a screw tightening torque.
FIG. 5 is a diagram showing blade straightness due to a difference in tightening torque.
[Explanation of symbols]
1 Developing roller 2 Developing blade 3 Blade 4 Holder 5 Screw

Claims (4)

In a blade support structure for fastening and supporting a thin plate-like blade to a holder means at a number of locations,
A blade support structure, wherein a tightening torque between the blade and the holder means is gradually reduced from both ends toward the center. In the developing blade structure in which the developing blade is in contact with or close to the developing roller,
The developing blade includes a blade that is in linear contact with or in close proximity to the peripheral surface of the developing roller in parallel with the axis of the developing roller, and holder means that is attached by tightening the blade at a number of axial positions. A developing blade structure characterized in that the tightening torque with the means is gradually reduced from both axial ends toward the center. A developer carrier that is rotatably disposed opposite to a latent image carrier having a latent image formed on the surface thereof, and supplies developer to the latent image carrier in order to visualize the latent image, and the development In a developing device having a developing blade for uniformizing the amount of the developer adhered to the surface of the agent carrier,
The developing blade includes a blade that is in line contact with or close to the surface of the developer carrying member, and holder means for fastening the blade at a plurality of locations, and tightening torque between the blade and the holder means from both ends of the blade. A developing device characterized by being gradually reduced toward the center. The developing device according to claim 3, wherein tightening torques at both ends of the blade are approximately equal.

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