JP2001312138A - Image forming apparatus, developing apparatus, and developer amount regulating member - Google Patents

Abstract

(57) [Problem] To prevent the occurrence of image defects while preventing the permanent deformation of a developing blade even when a toner having a finer, spherical, polymerized and lower melting point is used. SOLUTION: A developing blade 4 is composed of a rubber elastic body 4b and a metal supporting portion 4a, and a portion 4b1 of the rubber elastic body 4b which is in contact with the developing sleeve 3 via toner is formed into an R shape. The center position of the R shape is the same position as the center 0 of the developing sleeve 3, the diameter of the R shape is the same diameter as the developing sleeve 3, the concave amount of the R shape is within 30% of the thickness of the rubber elastic body 4 b, and the angle of the R shape Is set to 30 °, and formed by mold transfer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic or electrostatic recording type image forming apparatus such as a copying machine or a printer, a developing apparatus of the image forming apparatus, and a developer amount control of the developing apparatus. Regarding members.

[0002]

2. Description of the Related Art As an example of a conventional developing device, a developing container for storing a one-component developer (hereinafter referred to as "toner") is provided.
A developer carrying member (hereinafter referred to as a “developing sleeve”) attached to a developing container at a minute interval from an electrophotographic photosensitive member.
), A developer amount regulating member (hereinafter, referred to as a “developing blade”) that comes into contact with the developing sleeve and regulates a toner layer on the developing sleeve, and an elasticity that comes into contact with the developing sleeve and conveys the developer to the developing sleeve. A device provided with a transport roller is known.

In the above-described developing device, a developing blade is brought into contact with the developing sleeve as means for regulating the layer thickness of the toner carried and conveyed by the developing sleeve to the developing section to a thin layer.
By regulating the passage between the abutting portion of the developing blade and the developing sleeve by passing the toner, a thin layer of the toner is formed on the developing sleeve, and the latent image is formed on the toner by friction at the abutting portion. A method of giving a triboelectric charge (tribo) for development is employed.

As shown in FIG. 5, such a developing blade 104 has an elastic rubber body 104a for regulating a charge amount.
And a holder 104b made of metal or the like, which is a support for regulating the pressing force of the elastic rubber body 104a against the developing sleeve, and the surface 104b1 that contacts the developing sleeve via toner is linear. Has been proposed.

[0005] In addition, a toner having a positive charging series is formed by laminating a charge-imparting layer such as a silicone rubber whose charge is controlled on a thin plate made of metal or the like as a supporting portion. Similarly, a urethane rubber plate material which has been subjected to charge control or the like is used.

[0006]

However, when such a developing device is used, in order to obtain a colorized and high-definition image, a toner which has been miniaturized, made spherical, polymerized and has a low melting point is used. Then, insufficiently charged toner is included in the toner regulated by the developing blade on the developing sleeve, and as a result, there is a problem that an image defect such as density unevenness and a streak defect on the image occurs.

[0007] This is because a flat developing blade is pressed against a cylindrical developing sleeve via a toner, so that a toner finer than a conventional toner (about 5 μm in diameter) has a rubber elasticity on the surface of the developing blade. This is probably because the amount charged by friction with the body was not sufficient.

Further, when a polymerized and low-melting toner is used for higher definition of an image, the physical strength of the toner is reduced, and the pressing force of the developing blade is correspondingly reduced. Pressure. Therefore, it is necessary to supply a larger amount of triboelectric charge to the toner than in the conventional case.

Further, it is necessary to increase the contact area between the developing blade and the toner as much as possible by making the toner finer and spherical, but with a flat elastic developing blade, it is necessary to reduce the rubber thickness in order to increase the contact area. There is a problem that the set (permanent deformation strain) increases.

Accordingly, a main object of the present invention is to provide an image forming apparatus which prevents permanent deformation distortion of a developer amount regulating member even when a toner having a finer, spherical, polymerized and lower melting point is used. An object of the present invention is to provide an image forming apparatus and a developing device that can prevent occurrence of a defect.

[0011] Another object of the present invention is to provide a toner having a fine, spherical, polymerized, and low melting point toner.
An object of the present invention is to provide a developer amount regulating member capable of contributing to prevention of occurrence of image defects while preventing generation of permanent deformation distortion.

[0012]

The above object is achieved by an image forming apparatus, a developing device, and a developer regulating member according to the present invention. In summary, the present invention provides a developing container for containing a one-component developer, a developer carrier for carrying and transporting the one-component developer in the developing container to a developing unit, and a method for coating the developer carrier on the surface of the developer carrier. And a developer amount regulating member that regulates the amount of developer to be supplied, wherein the developer amount regulating member contacts the developer carrying member via a one-component developer. A rubber elastic body, and a metal supporting portion for supporting the rubber elastic body, wherein the rubber elastic body has an arc portion, and the center of the arc portion coincides with the center of the developer carrying member. An image forming apparatus characterized in that:

According to another aspect of the present invention, there is provided a developing container for containing a one-component developer, a developer carrying member for carrying and transporting the one-component developer in the developing container to a developing section; A developer amount regulating member that regulates the amount of developer applied on the body surface, wherein the developer amount regulating member is a rubber that comes into contact with the developer carrier via a one-component developer. An elastic body, and a metal supporting portion for supporting the rubber elastic body, wherein the rubber elastic body has an arc portion, and the center of the arc portion coincides with the center of the developer carrying member. A developing device is provided.

In the above invention, it is preferable that the concave portion of the arc portion is within 30% of the plate thickness of the developer regulating member. It is preferable that an angle formed by two lines connecting the center of the arc portion and both ends of the arc portion is 30 ° or less.

According to another aspect of the present invention, in a developer amount regulating member of a developing device using a one-component developer, a rubber elastic body and a metal supporting portion for supporting the rubber elastic body are provided. Wherein the rubber elastic body has an arc portion, and the arc portion is formed by a surface transfer forming method using a mold.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an image forming apparatus, a developing apparatus, and a developer amount regulating member according to the present invention will be described in more detail with reference to the drawings.

First, an embodiment of an electrophotographic image forming apparatus in which the present invention is embodied will be described with reference to FIG.

In FIG. 1, the image forming apparatus of the present embodiment has a photosensitive drum 11 as a member to be charged. The photosensitive drum 11 includes a conductive support such as aluminum.
This is a drum-type electrophotographic photosensitive member having a photosensitive layer formed on its outer peripheral surface as a basic constituent layer, and is rotationally driven at a predetermined peripheral speed clockwise in FIG.

Around the photosensitive drum 11, charging means 1
2, a developing device 14, a transfer unit 15, a cleaning unit 16, and the like.

The charging means 12 is a corona discharger which faces the peripheral surface of the photosensitive drum 11 and performs primary charging uniformly at a predetermined polarity and potential. The peripheral surface of the photoreceptor drum 11 which has been uniformly charged by the charging means 12 is then subjected to exposure L of target image information (laser beam scanning exposure, slit exposure of a document image, etc.) L by an exposure means not shown. ,
An electrostatic latent image corresponding to the target image information is formed on the peripheral surface.

Next, the electrostatic latent image is sequentially visualized as a toner image by the developing device 14. Next, the toner image is synchronized with the rotation of the photosensitive drum 11 from a paper feeding unit (not shown) by a transfer unit 15 and is conveyed to a transfer unit between the photosensitive drum 11 and the transfer unit 15 at an appropriate timing. The transfer material P is sequentially transferred onto the surface of the transfer material P.

The transfer means 15 of this embodiment is a corona discharger, and charges the toner image on the peripheral surface of the photosensitive drum 11 from the back of the transfer material P by charging the toner with the opposite polarity to the toner.
Is transferred to the surface side of

The transfer material P to which the toner image has been transferred is separated from the photoreceptor drum 11, conveyed to a heat fixing roll 18 as a fixing means, subjected to image fixing, and output as an image formed product.

The photoreceptor drum 11 after the transfer of the toner image is cleaned by the cleaning means 16 to remove contaminants such as untransferred toner, and is repeatedly subjected to image formation.

A plurality of elements of the electrophotographic apparatus, such as a photosensitive drum, a charging unit, a developing unit, and a cleaning unit, can be integrally formed as a process cartridge and can be detachably attached to the image forming apparatus main body. . Further, for example, the photosensitive drum and the developing device, and if necessary, a charging unit and a cleaning unit are integrally incorporated in the process cartridge, and can be detachably configured by using a guide unit such as a rail of the apparatus main body.

Next, the developing device will be further described with reference to FIG.

In FIG. 2, the developing device 14 has a developing container 2 containing a toner 6 as a one-component developer, and the photosensitive drum 1 rotating in the direction of arrow a in FIG. An electrostatic latent image on the photosensitive drum 1 is developed by transporting the toner 6 to the developing unit by the developing sleeve 3 which is a developer bearing member which is provided opposite to the developing sleeve, and is visualized as a toner image. Has become.

The developing sleeve 3 protrudes into the developing container 2 at a substantially right half circumferential surface in the drawing, and exposes a substantially left half circumferential surface outside the developing container 2 so as to be rotatable so as to face the photosensitive drum 1. It is laid horizontally. The developing sleeve 3 is driven to rotate in the direction of arrow b with respect to the rotation direction a of the photosensitive drum 1.

Further, a developing blade 4 serving as a developer amount regulating member is provided above the developing sleeve 3 in the developing container 2.
Is provided, and the developing sleeve 3 is more
The elastic roller 5 is provided at a position on the upstream side in the rotation direction of the roller.

The developing blade 4 is provided so as to be inclined downward toward the upstream side in the rotational direction of the developing sleeve 3, and abuts against the upper outer peripheral surface of the developing sleeve 3 in the rotational direction.

The elastic roller 5 is in contact with a portion of the developing sleeve 3 opposite to the photosensitive drum 1 and is supported so as to be rotatable in the direction of arrow c.

In the developing device 14, the elastic roller 5 rotates in the direction of the arrow c, and carries the toner 6 by the rotation of the elastic roller 5 to supply the toner 6 to the vicinity of the developing sleeve 3. At a contact portion (nip portion) where the roller 5 comes into contact, the toner 6 on the elastic roller 5 rubs against the developing sleeve 3 and adheres to the developing sleeve 3.

Thereafter, as the developing sleeve 3 rotates, the toner 6 adhered to the developing sleeve 3
At the contact portion between the developing sleeve 3 and the developing sleeve 3, and when passing therethrough, both the surface of the developing sleeve 3 and the developing blade 4 rub against each other and receive sufficient triboelectric charging.

The toner 6 charged as described above is
After coming out of the contact portion between the developing blade 4 and the developing sleeve 3, a thin layer of the toner 6 is formed on the developing sleeve 3, and is conveyed to the developing unit 7 opposed to the photosensitive drum 1 with a small gap. Is done. Then, by applying an alternating voltage in which, for example, DC and AC are superimposed as a developing bias between the developing sleeve 3 and the photosensitive drum 1 in the developing unit 7, the toner 6 on the developing sleeve 3 is Is transferred in accordance with the electrostatic latent image, and is attached to the electrostatic latent image, developed, and visualized as a toner image.

The toner 6 remaining on the developing sleeve 3 without being consumed in the developing in the developing section 7 is collected into the developing container 2 from a lower portion of the developing sleeve 3 with the rotation of the developing sleeve 3.

The collected toner 6 is peeled off from the developing sleeve 3 by the elastic roller 5 at a contact portion with the developing sleeve 3. At the same time, a new toner 6 is supplied onto the developing sleeve 3 by the rotation of the elastic roller 5, and a new toner 6 is supplied.
Is transported again to the contact portion between the developing sleeve 3 and the developing blade 4.

On the other hand, most of the stripped toner 6 is conveyed and mixed into the toner 6 in the developing container 2 with the rotation of the elastic roller 5, and the charged electric charge of the stripped toner 6 is reduced. Are distributed.

As the toner, known magnetic toners and non-magnetic color toners are used, and those having an average particle diameter of 3 to 15 μm are preferable.

Next, the developing blade, which is a feature of the present invention, will be described.

As shown in FIG. 3, the developing blade 4 of the present invention has a rubber elastic body 4b in contact with the developing sleeve 3 and supports the rubber elastic body 4b at one end, and the other end supports the rubber elastic body 4b. Sheet metal 4a which is a metal holder (supporting portion) to be formed
The portion of the rubber elastic body 4b that comes into contact with the developing sleeve 3 via the toner is a circular arc portion 4b1 having the same R shape as a part of the cross-sectional shape of the developing sleeve 3.

First, the rubber elastic body 4 of the developing blade 4
b at the portion that comes into contact with the developing sleeve 3 via the toner b.
A manufacturing method for forming the circular arc portion 4b1 will be described.

Examples of the rubber elastic body 4b having a toner charge imparting property used for the developing blade 4 include thermosetting / thermoplastic rubber, resin, and a composite material thereof. The metal used as the sheet metal 4b for regulating the thin layer coating amount of the toner is a zinc-coated steel sheet, a zinc light steel sheet, a silver alloy steel sheet having heat resistance and rust resistance, a stainless steel sheet, a phosphor bronze sheet, and an aluminum sheet. Use heat-resistant resin. The thickness of the sheet metal 4a is 0.1 mm to 5 m
In general, those having a thickness of up to about 1.2 to 1.6 mm are often used.

As a method of manufacturing the developing blade, a thermosetting material is formed into a rubber sheet by centrifugal molding, T-die extrusion, and the like, then cut into short lengths and adhered to a sheet metal by hot melt or the like. In addition, there is a method in which a sheet metal is inserted in a mold in advance, and a thermosetting material is cast and injection molded in the mold, and a method in which a thermoplastic material is similarly injection molded. In addition, a method of calendering and laminating into a thin metal foil shape is employed.

The thermosetting rubber material to be cast and injection-molded is preferably a rubber elastic material such as a liquid silicone rubber, a millable silicone rubber, a polyurethane rubber, a modified product thereof, or a blended product. In addition, as a thermosetting resin,
There are phenolic resin, urea resin, melamine resin and the like.

In addition, the thermoplastic resin material to be injection molded includes:
Polyethylene, AS resin, ASB resin, methacrylic resin (for general and heat resistance), polycarbonate, modified PPE,
Polyacetanol, polyamide, PBT resin, FR / P
ET resin, polyethylene, polypropylene, nylon na ferrite and the like.

Next, a method of forming an R shape (arc portion) of the rubber elastic body will be described.

In a type in which a rubber flat plate is formed in advance and then attached to a sheet metal, a method of forming the R shape by polishing or the like and then processing is used. An R-shaped projection is formed in the mold in advance, and the R shape is formed by transferring the shape. At this time, it is necessary to design the die size of the R-shaped convex protrusion to be larger than the actual size in consideration of heat shrinkage and the like. That is, when it is desired to form R having the same diameter as the developing sleeve, it is necessary to use a value obtained by multiplying the diameter of the developing sleeve by the heat shrinkage rate for the R projection shape of the mold.

The R-shaped position of the rubber elastic body of the developing blade must match the R position of the developing sleeve via the toner. This adjustment may be made by adjusting the length of the base of the sheet metal of the developing blade.

Next, the first embodiment of the developing blade according to the present invention will be described.
The eighth to eighth examples and comparative examples will be described with reference to FIG. 4. Further, the results of mounting these in a cartridge incorporated in the developing device to form an image and evaluating the image are shown in Table 1. Show.

The method of manufacturing the developing blade is based on the mold transfer except for the polishing in the eighth embodiment.

Example 1 In the first example, first, a mold (not shown) for producing the developing blade 4 was formed in the following convex shape.
That is, the portion of the rubber elastic body 4b of the developing blade 4 that comes into contact with the developing sleeve 3 via the toner, that is, the opposing surface of the mold of the nip portion (arc portion) 4b1 has an R shape (in this case, the diameter of the developing sleeve 3 is Since it is 12 mm, the heat shrinkage of the rubber (in the case of this silicone rubber, 3.6
% (The diameter of this silicone rubber is 1
2.45 mm)), the center position of the R shape is the same position as the center of the developing sleeve 3, and the depth of the recess of the R shape portion 4b1 is d = 0.4 mm (the rubber elastic body plate thickness t = 1.5 mm). 3
0%), the angle of the R shape, that is, the angle formed by two lines connecting the center position 0 of the R shape and the front and rear ends of the R shape portion in the circumferential direction of the developing sleeve 3 was α = 30 °. .

Then, the mold formed into the above-mentioned convex shape was heated in advance, and was previously coated with a silicone primer (Z3042: Bayer).
A 6 mm gin-coated steel sheet was placed in a mold, and LTV silicone rubber (LSRA13601: Bayer) was injected into the mold using an LSR injection molding machine (520C, manufactured by Ahburg). Then, after 40 seconds at 180 ° C., it was removed from the mold and heat-treated at 200 ° C. for 1 hour to obtain a rubber elastic developer amount regulating blade having a hardness of 40 degrees.

Example 2 In the second example, a mold (not shown) for producing the developing blade 4 was formed in a convex shape as follows. That is, the rubber opposing surface of the portion of the rubber elastic body 4b of the developing blade 4 that contacts the developing sleeve via the toner is formed into an R shape (in this case, the rubber elastic body contacting the developing sleeve via the toner is the R shape). The center position of the R shape is the upstream side where toner enters from the center 0 of the developing sleeve 4, and the depth of the dent is d.
= 0.4 mm (30% of rubber elastic body thickness t = 1.5 mm)
), And the angle of the R shape was α = 30 °.

Then, the mold formed in the above-mentioned convex shape was heated in advance, and was previously coated with a silicone primer (Z3042: Bayer).
A 6 mm gin-coated steel sheet was placed in a mold, and LTV silicone rubber (LSR AI3601: Bayer) was injected into the mold by an LSR injection molding machine (520C, manufactured by Aburg). Then, after 40 seconds at 180 ° C., it was removed from the mold and heat-treated at 200 ° C. for 1 hour to obtain a rubber elastic developer amount regulating blade having a hardness of 40 degrees.

Example 3 In the third example, a mold (not shown) for producing the developing blade 4 was formed in a convex shape as follows. That is, a portion of the rubber elastic body 4b of the developing blade 4 that comes into contact with the developing sleeve 3 via the toner, that is, the nip portion 4b
The opposite surface of the mold 1 is R-shaped (in this case, the portion of the rubber elastic body that comes into contact with the developing sleeve via toner is R-shaped and has a diameter of 12 mm). On the downstream side where the toner enters from the center of the developing sleeve, the depth of the recess is d = 0.4 mm (the rubber elastic body thickness t).
= Within 30% of 1.5 mm), the angle of the R shape is α = 30
゜

The mold formed in the shape of the convex protrusion is heated in advance, and a 1.6 mm-thick gin-coated steel sheet coated with a silicone primer (Z3042: Bayer) is placed in the mold. LTV silicone rubber (LSR AI3601: Bayer)
It was injected by an SR injection molding machine (520C, manufactured by Ahburg). After that, the mold was removed from the mold after 40 seconds at 180 ° C.
Heat treatment was performed at 00 ° C. for 1 hour to obtain a rubber elastic developer amount regulating blade having a hardness of 40 degrees.

Example 4 In the fourth example, a mold (not shown) for producing the developing blade 4 was formed in a convex shape as follows. That is, the portion of the rubber elastic body 4b of the developing blade 4 that comes into contact with the developing sleeve 3 via the toner, that is, the opposing surface of the mold at the nip portion has an R shape (in this case, the rubber elastic body that comes into contact with the developing sleeve via the toner). Body part is R shape and diameter 15
mm), and the center position of the R shape is set to the same position as the center 0 of the developing sleeve. As a result, the depth of the recess is d = 0.51 mm (the rubber elastic body plate thickness t = 1. 5
mm within 34%), and the angle of the R shape was α = 30 °.

Then, the mold formed in the above-mentioned convex shape was heated in advance, and was previously coated with a silicone primer (Z3042: Bayer).
A 6 mm gin-coated steel sheet was placed in a mold, and LTV silicone rubber (LSR AI3601: Bayer) was injected into the mold by an LSR injection molding machine (520C, manufactured by Aburg). Then, after 40 seconds at 180 ° C., it was removed from the mold and heat-treated at 200 ° C. for 1 hour to obtain a rubber elastic developer amount regulating blade having a hardness of 40 degrees.

Example 5 In the fifth example, a mold (not shown) for producing the developing blade 4 was formed in a convex shape as follows. That is, the rubber elastic portion 4b of the developing blade 4 has an R-shaped facing surface of the portion that contacts the developing sleeve 3 via the toner (in this case, the portion of the rubber elastic body that contacts the developing sleeve via the toner). The center position of the R shape is the same as the center of the developing sleeve 3, and as a result, the depth of the dent is d = 0.34 m.
m (rubber elastic body thickness t = within 23% of 1.5 mm), R
The angle of the shape was α = 30 °.

Then, the mold formed in the above-mentioned convex shape was heated in advance, and was previously coated with a silicone primer (Z3042: Bayer).
A 6 mm gin-coated steel sheet was placed in a mold, and LTV silicone rubber (LSR AI3601: Bayer) was injected into the mold by an LSR injection molding machine (520C, manufactured by Aburg). Then, after 40 seconds at 180 ° C., it was removed from the mold and heat-treated at 200 ° C. for 1 hour to obtain a rubber elastic developer amount regulating blade having a hardness of 40 degrees.

Embodiment 6 In the sixth embodiment, a mold (not shown) for producing the developing blade 4 was formed in a convex shape as follows. That is, the portion of the rubber elastic body 4b of the developing blade 4 which is in contact with the developing sleeve 3 via the toner is formed into an R-shaped surface (in this case, the rubber elastic body contacting the developing sleeve with the toner). Is processed into an R shape having a diameter of 15 mm), the center position of the R shape is the same as the center of the developing sleeve 3, and the depth of the recess is d = 0.4 mm (the rubber elastic body thickness t = 1). The angle of the R shape was α = 26.5 °.

The metal mold formed into the above-mentioned convex shape is heated in advance, and a 1.6 mm-thick zinc-coated steel sheet coated with a silicone primer (Z3042: Bayer) is placed in the metal mold. , This is LTV
Silicone rubber (LSR AI3601: Bayer) was injected by an LSR injection molding machine (520C, manufactured by Aburg). Then, after 180 seconds at 180 ° C, the mold was removed from the mold.
Heat treatment was performed at 200 ° C. for 1 hour to obtain a rubber elastic developer amount regulating blade having a hardness of 40 degrees.

Example 7 In the seventh example, a mold (not shown) for producing the developing blade 4 was formed in a convex shape as follows. That is, the rubber elastic body 4b of the developing blade 4 has an R-shaped opposed surface of the mold that contacts the developing sleeve 3 via the toner (in this case, the rubber elastic body that contacts the developing sleeve via the toner is The center position of the R shape is the same as the center of the developing sleeve 3, and the depth of the recess is d = 0.51 mm (the rubber elastic body plate thickness t = 1. Within 34% of 5 mm)
The angle of the shape was α = 32.5 °.

Then, the mold formed into the above-mentioned convex protrusion shape was heated in advance, and was previously coated with a silicone primer (Z3042: Bayer).
A 6 mm gin-coated steel sheet was placed in a mold, and LTV silicone rubber (LSR AI3601: Bayer) was injected into the mold by an LSR injection molding machine (520C, manufactured by Aburg). Then, after 40 seconds at 180 ° C., it was removed from the mold and heat-treated at 200 ° C. for 1 hour to obtain a rubber elastic developer amount regulating blade having a hardness of 40 degrees.

Embodiment 8 As an eighth embodiment, a mold in which the opposite surface of the mold at the portion of the rubber elastic portion of the developing blade that comes into contact with the developing sleeve via the toner is formed in a flat shape is heated in advance,
In addition, a primer for silicone (Z304
2. A 1.6 mm-thick gin-coated steel sheet coated with Bayer) was placed in a mold, and LTV silicone rubber (LSR A13601: Bayer) was injected into the mold with an LSR injection molding machine (520C manufactured by Aburg). After that, it was removed from the mold after 40 seconds at 180 ° C., and heat-treated at 200 ° C. for 1 hour to obtain a rubber elastic developer amount regulating blade having a hardness of 40 degrees. Then, the rubber polishing portion of the rubber elastic portion of the developing blade is formed into an R shape (R center position is the same position as the center of the developing sleeve, concave depth is 0.4 mm and diameter is 12 mm). (As a result, within 30% of the plate thickness of 1.5 mm, R
The angle became a concave projection shape at 30 °). Thereafter, the cartridge was mounted on a cartridge containing a developing device, an image was formed, and the image was evaluated.

COMPARATIVE EXAMPLE Next, as a comparative example with the above-mentioned embodiment, in order to obtain the developing blade shown in the conventional example, the rubber elastic body of the developing blade is opposed to the mold at the portion in contact with the developing sleeve via the toner. The surface was formed in a flat shape.

Then, the mold is heated in advance,
In addition, a primer for silicone (Z304
A sheet of 1.6 mm-thick gin-coated steel sheet coated with (2: Bayer) was placed in a mold, and LTV silicone rubber (LSRAI 3601: Bayer) was injected into the mold using an LSR injection molding machine (520C, manufactured by Aburg). afterwards,
After 40 seconds at 180 ° C., it was removed from the mold and heat-treated at 200 ° C. for 1 hour to obtain a rubber elastic developer amount regulating blade having a hardness of 40 degrees.

Table 1 below shows the comparison results when the shapes of the elastic developer amount regulating members of the above-described Examples and Comparative Examples were evaluated for their shapes and actual images.

The injection conditions were all 2 seconds injection time,
The injection pressure of 800 bar and the image evaluation indicate the state of density unevenness and white stripes after development. And as image evaluation,
：: good, Δ: not bad but uneven, X: bad.

[0070]

[Table 1] As is clear from Table 1, in the first embodiment, the surface of the developing blade that comes into contact with the developing sleeve via the toner has an R shape, and the center position of the R shape and the diameter of the R shape are the same as the center position of the developing sleeve. The concave amount of the R shape is within 30% of the thickness of the rubber elastic body, and the angle of the R shape is within 30 °.
Further, the method of manufacturing the R shape is formed by a surface transfer forming method using a mold. As a result, a uniform thin layer toner can be formed on the developing sleeve, and therefore, the image evaluation is excellent.

In contrast, in the second embodiment and the third embodiment, since the center position of the R shape is different from the center of the sleeve, the image becomes uneven, and in the fourth embodiment, the radius of the R shape is large. When the diameter is 15 mm, the image evaluation is slightly worse than that of the first embodiment, and since the amount of depression of the R shape is 30% or more of the thickness of the rubber elastic body, the durability is poor. In the fifth embodiment, the diameter of the R shape is small. Is 10 mm, the image becomes uneven. Further, in the sixth embodiment, since the R shape is 15 mm, unevenness is formed on the image. In the seventh embodiment, since the angle of the R shape is 30 ° or more, the image unevenness is further increased. In the eighth embodiment, the R shape is exactly the same as that of the first embodiment, but since the manufacturing method of the R shape is a polishing method, there is unevenness in the R surface as compared with the mold transfer of the first embodiment. As a result, the image tends to be uneven.

Next, a method used conventionally is shown in a comparative example. Here, since the surface of the developing blade that comes into contact with the developing sleeve via the toner is flat, development using fine toner (about 5 μm in diameter) does not uniformly charge the toner on the developing sleeve. However, when incorporated and used in a developing device, the image was slightly defective in density unevenness and white stripes.

In the first embodiment, the rubber elastic body of the developing blade that comes into contact with the developing sleeve has the same R shape as the cross-sectional shape of the developing sleeve, so that the size of the developing blade can be reduced.
Even if a toner with a spherical, polymerized, or low-melting point is used, sufficient charge can be applied to the toner by the developing blade on the developing sleeve. As a result, uneven image density and streak defects due to insufficient charging can be solved. We were able to.

The electrophotographic image forming apparatus which can use the developing device according to the present invention includes a copying machine, a laser beam printer, an LED printer, an electrophotographic plate making system, and the like.

[0075]

As is apparent from the above description, according to the image forming apparatus and the developing apparatus of the present invention, the amount of the developer regulating member is such that the rubber elastic member is in contact with the developer carrying member via the one-component developer. Body, and a metal supporting portion for supporting the rubber elastic body, wherein the rubber elastic body has an arc portion, and the arc portion has a center coincident with the center of the developer carrying member. Even when using a toner that has been miniaturized, spheroidized, polymerized, or lowered in melting point, it is possible to prevent the occurrence of image defects while preventing the occurrence of permanent deformation of the developer amount regulating member, and obtain a high quality image. be able to.

A developer amount regulating member of a developing device using a one-component developer has a rubber elastic body and a metal supporting portion for supporting the rubber elastic body, wherein the rubber elastic body has an arc shape. The above-described effect can be obtained by forming the circular arc portion by the surface transfer forming method using a mold.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of an image forming apparatus in which the present invention is embodied.

FIG. 2 is a schematic configuration diagram illustrating a developing device used in the image forming apparatus of FIG. 1;

FIG. 3 is a side view showing a developing blade used in the developing device of FIG. 2;

FIG. 4 is an explanatory diagram showing a developing blade and a developing sleeve according to the first embodiment of the present invention.

FIG. 5 is a side view showing an example of a conventional developing blade.

[Explanation of symbols]

 Reference Signs List 3 developing sleeve (developer carrying member) 4 developing blade (developer amount regulating member) 4a supporting portion 4b rubber elastic body 4b1 R-shaped portion (arc portion) 14 developing device

Claims (7)

[Claims] 1. A developing container for containing a one-component developer, a developer carrier for carrying and transporting the one-component developer in the developing container to a developing unit, and a developing device coated on a surface of the developer carrier. An image forming apparatus comprising a developing device having a developer amount regulating member that regulates an amount of developer, wherein the developer amount regulating member is a rubber elastic body that is in contact with the developer carrier via a one-component developer. And a metal supporting portion for supporting the rubber elastic body, wherein the rubber elastic body has an arc portion, and the center of the arc portion coincides with the center of the developer carrying member. Image forming apparatus. 2. The image forming apparatus according to claim 1, wherein a concave amount of the arc portion is within 30% of a plate thickness of the developer regulating member. 3. The image forming apparatus according to claim 1, wherein an angle formed by two lines connecting the center of the arc portion and both ends of the arc portion is 30 ° or less. 4. A developing container for containing a one-component developer, a developer carrier for carrying and transporting the one-component developer in the developing container to a developing unit, and a developing device coated on the surface of the developer carrier. A developer amount regulating member that regulates the amount of developer, wherein the developer amount regulating member is a rubber elastic body that is in contact with the developer carrier via a one-component developer, and the rubber elastic body Wherein the rubber elastic body has an arc portion, and the center of the arc portion coincides with the center of the developer carrier. 5. The developing device according to claim 4, wherein the concave portion of the arc portion is within 30% of a plate thickness of the developer regulating member. 6. The developing device according to claim 4, wherein an angle formed by two lines connecting the center of the arc portion and both ends of the arc portion is 30 ° or less. 7. A developer amount regulating member of a developing device using a one-component developer, comprising: a rubber elastic body; and a metal supporting portion for supporting the rubber elastic body, wherein the rubber elastic body has an arc shape. Wherein the arc portion is formed by a surface transfer forming method using a mold.