JPH0713411A - Developing device - Google Patents

Abstract

PURPOSE:To prevent the amount of developer on a developer carrier from increasing on both end parts in a longitudinal direction as compared with that on the central part in the same direction without providing a special member. CONSTITUTION:The length of a thin layer blade 17 in the longitudinal direction is made equal to or exceeding the length of the developing roller 6 in the same direction, the central part of the thin layer blade 17 in the same direction is formed on a flat abutting part 17a whose flat surface is made to press-contact with a part opposite, to an image area of the developing roller 6, and also both end parts of the thin layer blade 17 are formed on edge abutting parts 17b whose edge part is made to press-contact with a part opposite to a non- image area of the developing roller 6. By having such a constitution, toner lying on both end parts of the developing roller 6 can be scraped only by the edge abutting part 17b of the thin layer blade 17, so that the amount of the toner lying on both end parts of the developing roller 6 in the longitudinal direction is prevented from increasing more than the amount of the toner lying on the central part of the developing roller 6 in the same direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing device used in an image forming apparatus such as a copying machine, a facsimile machine or a printer, and more specifically, a developer is carried on the surface and conveyed to a portion facing the image carrier. And a developer supplying means for supplying a developer to the developer carrying body, and a layer thickness of the developer supplied to the developer carrying body, which is in pressure contact with the surface of the developer carrying body. The present invention relates to a developing device having a developer layer regulating member for regulating.

[0002]

2. Description of the Related Art Heretofore, as a developing device of this type, for example, a sponge material or the like configured to be rotatable about a rotation axis with respect to a developer carrier configured to be rotatable about a rotation axis. The developer supplying means composed of the elastic member is brought into pressure contact with the developer carrier, and the developer composed of the non-magnetic toner is charged at the pressure contact portion between the developer carrying means and the developer supplying means while being supplied from the developer supplying means to the developer carrying means. Then, the developer on the developer carrier is further charged while being regulated to a predetermined thickness by the developer layer regulating member with which the antinode of the developer carrier in the longitudinal direction abuts, and the developer is regulated to this predetermined thickness and charged. It is known that the latent image is visualized by supplying the developed developer to the image carrier.

Conventionally, in order to form a uniform developer layer over the longitudinal direction of the developer layer regulating member without spilling of the developer, the longitudinal direction end portions of the developer layer regulating member. There is known a developing device having a structure in which the rigidity of the developer is made stronger than the rigidity of the intermediate part, specifically, the reinforcing members are attached to the both ends, and the developer layer regulating member is brought into contact with the developer carrying member. (For example, Japanese Patent Publication No. 3-946
(See Japanese Patent Publication No. 5).

By the way, according to the structure of the conventional developing device, the image carrier generally has a central portion in the longitudinal direction as an image region and both end portions as non-image regions. When the length in the longitudinal direction of the body is set equal to the length in the longitudinal direction of the image carrier, the consumption amount of the developer on the developer carrier due to being used for development in the area facing the image carrier is The longitudinal ends of the developer carrier facing the non-image area of the image carrier are smaller than the longitudinal center of the developer carrier facing the image area of the image carrier. Therefore, on the developer carrier that has passed through the area facing the image carrier, a large amount of developer remains at both ends as compared with the center in the longitudinal direction. When the length in the longitudinal direction of the developer carrying member and the length in the longitudinal direction of the developer supplying unit are set to be equal, the developer supplying unit covers the entire width of the developer carrying unit which has passed through the area facing the image carrier. By supplying the new developer uniformly, the amount of the developer on the developer carrier tends to increase at both end portions as compared with the central portion in the longitudinal direction.

As described above, when the amount of the developer on the developer carrying member increases at both end portions as compared with the central portion in the longitudinal direction, for example, the developer may be scattered from the developing device. There is a drawback that the developer easily enters the seal portion of the bearing portion of the carrier.

Further, when the amount of developer on the developer carrying member increases at both end portions as compared with the central portion in the longitudinal direction, the charge amount (hereinafter referred to as Q / m) of the developer at both end portions becomes the central portion. Is lower than the Q / m of the developer, and for example, an inlet seal is provided in the vicinity of the opening of the developing device so as to contact the surface of the developer carrier and prevent the developer from being blown out from the inside of the developing device. In this case, there is a drawback that the developer at both ends having a low Q / m may be dropped from the developer carrier by the inlet seal and may be accumulated in the vicinity of the opening of the developing device, and the developer may be scattered.

Therefore, in order to eliminate the above-mentioned drawbacks, the developer layer regulating member is brought into contact with the developer carrying member at both end portions in the longitudinal direction of the contact edge with respect to the developer carrying member. There is known a developing device provided with a developer intrusion prevention unit for preventing the invasion of the developer (for example, Japanese Patent Laid-Open No. 61-185).
770).

[0008]

However, in the developer layer regulating member disclosed in Japanese Patent Laid-Open No. 61-185770, the length in the longitudinal direction is shorter than the length in the longitudinal direction of the developer carrying member. There is a risk that the developer carried on the surface of the developer carrying member outside both longitudinal ends of the layer regulating member may pass through the side of the developer intrusion prevention section and enter the back side thereof. However, there is a problem that it is necessary to separately provide the seal member.

The present invention has been made in view of the above problems, and an object of the present invention is that the amount of the developer on the developer carrying member is smaller than that in the central portion in the longitudinal direction without providing a special member. By preventing the developer from increasing at both ends, it is possible to prevent the developer from invading the seal portion of the bearing portion of the developer carrier and scattering of the developer due to low Q / m of the developer. Is to provide.

[0010]

In order to achieve the above-mentioned object, the invention of claim 1 is a developer carrying member carrying a developer on the surface and carrying the developer to a portion facing the image carrying member, A developer supplying means for supplying the developer to the developer carrying member; and a developer layer regulating member for pressing the surface of the developer carrying member to regulate the layer thickness of the developer supplied to the developer carrying body. In a developing device having: an abdomen pad portion, whose abdominal surface is in pressure contact with at least the width direction region of the developer carrier facing the image region on the image carrier, An edge abutting portion whose edge portion is in pressure contact with a widthwise region of the developer carrier facing the non-image region of the image carrier, and
It is characterized in that the widthwise outer end of the edge abutting portion coincides with the widthwise outer end of the developer carrier or extends to the outside.
According to a second aspect of the present invention, in the developing device according to the first aspect, a notch is provided at a boundary between the abdomen contact portion and the edge contact portion on the free end side of the developer layer restriction member. Is. According to a third aspect of the invention, in the developing device according to the first aspect, a reinforcing member is attached to the edge contact portion of the developer layer regulating member. According to a fourth aspect of the present invention, in the developing device according to the first aspect, a convex portion is provided on the free end side of the edge abutting portion of the developer layer regulating member, the edge portion being in pressure contact with the developer carrier. It is what

[0011]

According to the first aspect of the invention, the developer on the widthwise area of the developer carrying body facing at least the image area of the image carrying body is regulated to a predetermined thickness by the abdomen contact portion of the developer layer regulating member. Further, in general, the developer on the widthwise region of the longitudinal end of the developer carrier facing the non-image region provided at the longitudinal end of the image carrier has a widthwise outer end of the developer carrier. It is scraped off only by the edge portion of the edge contact portion which is configured so as to match the widthwise outer end portion or extend to the outer side. According to the second aspect of the present invention, by providing the notch at the boundary between the abdomen contact portion and the edge contact portion on the free end side of the developer layer restriction member,
The abdomen contact portion and the edge contact portion of the developer layer regulating member are independently interlocked with each other and press-contact with the surface of the developer carrier.
In the third aspect of the invention, since the reinforcing member is attached to the edge contact portion of the developer layer restriction member, the rigidity of the edge contact portion is increased, and the edge of the edge contact portion that is in pressure contact with the developer carrier. The portion surely comes into pressure contact with the developer carrying member. According to the invention of claim 4, the edge contact portion of the developer layer restriction member is provided on the free end side of the edge contact portion of the developer layer restriction member. The contact pressure with respect to the developer carrying member of the part becomes high.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a developing device of an electrophotographic copying machine (hereinafter referred to as a copying machine) which is an image forming apparatus will be described below. In the copying machine according to this embodiment, when the print button is turned on, a latent image is formed on the image carrier through a reading system, a decharging system, and a writing system (not shown), and the latent image is formed into a toner image by the developing device. The toner image is transferred to the transfer material, which is visualized as the above, and is conveyed at the timing of the leading edge of the latent image, at the transfer section, and a single copy is obtained through the fixing and discharging section. Less than,
The developing device according to this embodiment will be described. The developing device according to the following description uses a non-magnetic one-component developer (hereinafter referred to as toner) as the developer. FIG. 1 is a schematic configuration diagram of a developing device according to this embodiment, and FIG. 2 is an upper sectional view of the developing device. This developing device 1 has a leaf spring 10 at the rear.
1 and a cam 102 rotatably arranged so that the peripheral surface is in contact with the leaf spring 101. When the print button is turned on, the cam 102 rotates to push the leaf spring 101. The entire device is a photosensitive drum 1 as an image carrier.
It is designed to be moved in the 00 direction. The developing device 1 includes a lower casing 2 and an upper left lid 3 and an upper right lid 4 attached to the lower casing 2, which form a casing, and the lower casing 2 is provided at a position facing the photosensitive drum 100. An opening 5 is formed with the upper left lid 3. Further, in the developing device 1, from the opening 5 to the photosensitive drum 10.
And a sponge roller 7 arranged in pressure contact with the developing roller 6 to supply the toner T to the developing roller 6.
The first agitator 8 that conveys the toner T in the direction of the sponge roller 7 and the second agitator 9 that conveys the toner T in the direction of the first agitator 8 are rotatable on the front and rear side plates 10 and 11 of the developing device 1, respectively. It is supported and provided.
Here, a bias voltage is applied to each of the developing roller 6 and the sponge roller 7 so that a potential difference that causes the toner T toward the developing roller 6 is generated.

In the case of N / P development, for example, a developing bias voltage having the same polarity as the toner T is applied to the developing roller 6. A gap holding roller 13 having a diameter slightly larger than that of the developing roller 6 is attached to both ends of the shaft 61 supported by the front and rear side plates 10 and 11 via the ball bearings 12 of the developing roller 6. The gap holding rollers 13 are aluminum surfaces (indicated as Al surfaces in FIG. 2) formed on both axial ends of the photoconductor drum 100 when the developing device 1 is pushed toward the photoconductor drum 100 by the rotation of the cam 102. )
To stop the movement of the developing device 1 and form a predetermined gap between the developing roller 6 and the photosensitive drum 100. Further, a region in which the developing roller 6 and the photosensitive drum 100 are opposed to each other (hereinafter referred to as a developing region) A is provided on the downstream side in the rotating direction of the developing roller 6 in the forward direction with respect to the rotating direction of the developing roller 6. An inlet seal 14 that is arranged in the manner described above is provided. The inlet seal 14 does not scrape off the toner T remaining on the developing roller 6 that has passed the developing area A, and prevents the toner T from blowing out from the inside of the developing device 1. Further, on the downstream side in the rotation direction of the developing roller 6 with respect to the position where the inlet seal 14 is provided, the developing roller 6 and, for example, about 0.
The entrance fence 15 is provided with a gap of 3 mm. The entrance fence 15 prevents the toner T from moving toward the opening 5 due to the rotation of the sponge roller 7.

Further, on the downstream side in the rotation direction of the developing roller 6 with respect to the pressure contact portion B between the developing roller 6 and the sponge roller 7,
A thin layer blade 17 is provided as a developer layer regulating member formed wider than the developing roller 6. Specifically, the thin layer blade 17 is arranged in the forward direction such that the free end 17a is located on the downstream side in the rotation direction of the developing roller 6 and the fixed end 17b is located on the upstream side. The fixed end portion 17b of the thin layer blade 17 is fixedly attached to the blade holder 16 attached to the upper left lid 3 and the upper right lid 4. Details of the thin blade 17 will be described later.

A shaft 71 of the sponge roller 7 is supported by the front and rear side plates 10 and 11 via a ball bearing 19 and a G seal 20, and is configured to be in pressure contact with the developing roller 6 so as to be rotatable. The length of the sponge roller 7 in the longitudinal direction is shorter than the developing roller 6 and longer than the image area width of the photosensitive drum 100.
A gap D is formed between each of them. On the right side of the sponge roller 7 in FIG. 1, the toner T conveyed by the first agitator 8 is transferred to the developing roller 6 and the thin layer blade 1.
A shield plate 21 is provided so as not to skip the wedge-shaped portion E formed by 7 and 7. The length of the shield plate 21 in the longitudinal direction is longer than that of the sponge roller 7 and an agitator member 83, which will be described later, and is shorter than the distance between the front and rear side plates 10 and 11, and is between the front and rear side plates 10 and 11. A gap F is formed in each. And sponge roller 7
At the same time, the toner T and the air that is compressed and accumulated inside when it comes into contact with the developing roller 6 at the pressure contact portion B are discharged at the same time,
As a result, the toner T is transferred to the developing roller 6, and on the other hand, the discharged air flows to the left and right in the gap formed by the sponge roller 7 and the lower casing 2, and between the sponge roller 7 and the front and rear side plates 10 and 11. Flow through the gap D formed respectively and the gap F formed between the shield plate 21 and the front and rear side plates 10 and 11 to the inner side of the developing device 1.

The first agitator 8 is a dry bearing 22.
A plate-shaped member 82 is attached to a shaft 81 supported by the front and rear side plates 10 and 11 via an agitator member 83 having a length that is about 3 mm into the lower casing 2 at one end of the plate-shaped member 82. Is attached. The agitator member 83 slides along the lower casing 2 by the rotation of the first agitator 8, conveys the toner T toward the sponge roller 7, and when the contact with the lower casing 2 is released, the agitator member 83 moves. The toner T accumulated in the vicinity G is loosened and dropped into the wedge-shaped portion formed by the sponge roller 7 and the lower casing 2. In addition, the plate member 82
A toner scraping member 84 formed in a hook shape is attached to both ends of the other edge in the longitudinal direction. The toner scraping member 84 circulates the toner T in the vicinity of the front and rear side plates 10 and 11, so that the air discharged from the sponge roller 7 is formed between the shield plate 21 and the front and rear side plates 10 and 11, respectively. To make the flow smoothly.

The second agitator 9 is a dry bearing 23.
A plate-shaped member 92 is attached to a shaft 91 supported by the front and rear side plates 10 and 11 via an agitator member 93 having a length that is about 1 mm into the lower casing 2 at one end edge of the plate-shaped member 92. Is attached.

In the developing device 1 having the above structure,
When the print button is turned on and the cam 102 rotates, the entire apparatus moves toward the photoconductor drum 100, and when the gap holding roller 13 comes into contact with the aluminum surface of the photoconductor drum 100 and stops, the power from a drive device (not shown) is applied. Transmitted to the developing roller 6, the developing roller 6, the sponge roller 7,
The first agitator 8 and the second agitator 9 are respectively shown in FIG.
It begins to rotate in the direction of the arrow shown inside. Then, the toner T supplied to the sponge roller 7 by the second agitator 9 and the first agitator 8 is pressed against the developing roller 6 by a pressure contact portion B.
The toner particles are triboelectrically charged, adhere to the developing roller 6 to which a voltage having the same polarity as the toner T is applied, and are conveyed by the rotation of the developing roller 6. The toner T on the developing roller 6 is regulated to a predetermined layer thickness by the thin layer blade 17 at the contact portion C between the developing roller 6 and the thin layer blade 17, and at the same time, is triboelectrified and conveyed to the developing area A, where the development is performed. In the area A, the latent image on the photosensitive drum 100 flies to be used for development.

Next, the thin layer blade 17 in the developing device 1 according to this embodiment will be described. As described above, the thin-layer blade 17 according to the present embodiment is configured such that its longitudinal length is longer than the longitudinal length of the developing roller 6. Further, as shown in FIG. 3, the thin layer blade 17 is configured by cutting out both longitudinal end portions on the free end side thereof. Then, as shown in FIG. 4, the central portion of the thin-layer blade 17 which is not cut out has the belly surface 17c where the belly surface 17c is in pressure contact with the developing roller 6 with a predetermined nip width.
Further, as shown in FIG. 5, both end portions of the thin layer blade 17 are edge contact portions 17b where the edge portions 17d are in pressure contact with the developing roller 6. Here, the belly pad 17a is provided to face at least the peripheral surface portion of the developing roller 6 that faces the image area of the photosensitive drum 100 (hereinafter referred to as the image area facing portion), and the edge pad 17b.
Are provided so as to face the peripheral surface portions (hereinafter, referred to as non-image area facing portions) of the developing roller 6 on the outer sides in the longitudinal direction of the image area facing portions.

With the above structure, the toner T on the non-image area facing portions of both ends of the developing roller 6 is scraped by the edge portions 17d of the edge contact portions 17b provided at both ends of the thin layer blade 17. Further, the toner T on the image area facing portion of the developing roller 6 is regulated to a predetermined thickness by the belly surface 17c of the belly pad 17a provided in the central portion of the thin layer blade 17. As a result, it is possible to prevent the amount of toner T at both ends of the developing roller 6 in the longitudinal direction from becoming larger than the amount of toner T at the center of the developing roller 6 in the longitudinal direction.

Here, as shown in FIG. 6, on the free end side of the thin layer blade 17, the belly pad 17a and the edge pad 17 are provided.
By providing the notch 17e at the boundary with b, the abdominal contact portion 17a and the edge contact portion 17b of the thin layer blade 17 are independent without being interlocked with each other, and the thin layer blade 17 has an integral structure, The roller 6 can be pressed against the image area facing portion and the non-image area facing portion, and the pressure contact pressure between the abdominal contact portion 17a and the edge contact portion 17b with respect to the developing roller 6 can be changed. According to this configuration, the edge contact portion 17b of the thin-layer blade 17 can be pressed against the non-image area facing portion of the developing roller 6 independently of the belly contact portion 17a. Blade 1 for toner T at the boundary of
The scraping effect of 7 can be increased. In the case of this configuration, the edge contact portion 17b of the thin layer blade 17
It is more preferable to attach a thin leaf spring or the like to the upper surface of the above to increase the pressure contact pressure of the edge contact portion 17b against the non-image area facing portion of the developing roller 6.

As shown in FIG. 7 (a), the edge contact portion 17b of the thin layer blade 17 is made of a thin plate of stainless steel or the like, and is, for example, a U-shaped reinforcing member 171 (see FIG. 7).
(See (b)) and L-shaped reinforcing member 172 (see FIG. 7).
(See (c)) by using an adhesive or a double-sided tape to attach the edge contact portion 1 of the thin-layer blade 17.
The rigidity of 7b can be increased, and the edge portion 17d of the edge contact portion 17b can be reliably pressed against the developing roller 6. In the case of this configuration, the reinforcing member 1
The rigidity of the edge contact portion 17b can be changed by changing the lengths of the reference numerals 71 and 172 indicated by H in the figure, so that the contact pressure of the edge portion 17d against the developing roller 6 can be changed. In addition, this reinforcing member 1
71 and 172 are abdominal support parts 1 as shown in FIG.
7a and the edge contact portion 17b not only in the thin layer blade provided with the notch 17e at the boundary, but also when used for the thin layer blade not provided with the notch 17e as shown in FIG. This is effective in increasing the rigidity of the contact portion 17b.

As shown in FIG. 8, the thin layer blade 1
7 is provided with a notch 17c at the boundary between the belly pad 17a and the edge pad 17b, and a convex portion 17f is provided on the free end side of the edge pad 17b. An edge portion of the convex portion 17f on the upstream side in the rotation direction of the developing roller 6 is provided. The edge portion 17g is pressed by pressing 17g to a position on the extension of the nip between the belly pad 17a and the developing roller 6 in the longitudinal direction of the developing roller 6.
It is possible to increase the pressure contact pressure of the developing roller 6 against the developing roller 6 to enhance the scraping effect of the toner T. The convex portion 17f
May be integrally molded with the thin layer blade 17, or may be made of a rubber material such as polyurethane and provided separately from the thin layer blade 17 and attached to the thin layer blade 17 with an adhesive or a double-sided tape.

As described above, according to this embodiment, the thin layer blade 1
Since the length of the developing roller 6 in the longitudinal direction is larger than the length of the developing roller 6 in the longitudinal direction, the non-image area facing portions of the developing roller 6 at both ends in the longitudinal direction can be provided without providing a special member. It is possible to prevent the toner T of No. 2 from being scraped off only by the edge contact portion 17b of the thin layer blade 17 and prevent the amount of toner T on the non-image area facing portions at both ends in the longitudinal direction of the developing roller 6 from increasing. As a result, the toner T can be prevented from entering the seal portion of the bearing portion of the developing roller 6. Further, according to the present embodiment, the toner T adhered to both ends of the developing roller 6 that are not in pressure contact with the sponge roller 7 and is not subjected to the charging action due to the pressure contact between the developing roller 6 and the sponge roller 7, and thus the toner T having a low Q / m Is scraped off by the edge contact portion 17b of the thin layer blade 17, so that the toner T at both ends of the developing roller 6 is scraped off by the inlet seal 14 and accumulated on the upper surface of the inlet seal 14 due to the low Q / m. It can be prevented. As described above, the toner T enters the seal portion of the bearing portion of the developing roller 6 and the inlet seal 14
It is possible to prevent the toner T from scattering due to the accumulation of the toner T on the upper surface. Further, the notch 17e is provided to provide the edge contact portion 1
7b is independent of the abdomen pad 17a and is brought into pressure contact with the non-image area facing portion of the developing roller 6 or the reinforcing member 1a.
71 and 172 are attached to increase the rigidity of the edge contact portion 17b, or the edge contact portion 17b is provided with a convex portion 17f to increase the pressure contact pressure with respect to the developing roller 6 to increase the toner in the non-image area facing portion of the developing roller 6. By reliably scraping T, it is possible to more reliably prevent the toner T from scattering.

[0025]

According to the first aspect of the present invention, the widthwise outer end of the edge contact portion of the developer layer regulating member is aligned with the widthwise outer end of the developer carrier, or the outer side thereof. By being configured to extend, the developer on the widthwise region of the longitudinal end portion of the developer carrier that generally faces the non-image region provided at the longitudinal end portion of the image carrier, Since it can be scraped off only by the edge portion of the edge contact portion of the developer layer regulating member, it is possible to prevent the developer at the longitudinal end portion of the developer carrier from increasing without providing a special member. As a result, it is possible to prevent the developer from entering the seal portion of the bearing portion at the longitudinal end of the developer carrier and to prevent the Q / m of the developer from being lowered. There is an effect that can prevent. According to the second aspect of the invention, the abdomen contact portion and the edge contact portion of the developer layer restriction member are independently pressed against the surface of the developer carrying member without interlocking with each other, and thus face the image area of the image carrier. The effect of scraping off the developer at the boundary between the widthwise area of the developer carrier and the widthwise area of the developer carrier facing the non-image area of the image carrier is increased. Then, there is an effect that the scattering of the developer can be more surely prevented. According to the invention of claim 3, the edge contact portion of the developer layer restriction member has high rigidity,
Since the edge portion of the edge contact portion, which comes into pressure contact with the developer carrying member, surely comes into pressure contact with the developer carrying member, therefore, with respect to the developer in the widthwise region of the developer carrying member facing the non-image region of the image carrying member. This has the effect of increasing the scraping effect.
Then, there is an effect that the scattering of the developer can be more surely prevented. According to the invention of claim 4, since the pressure contact pressure of the edge contact portion of the developer layer regulating member against the developer carrier increases, the scraping effect on the developer in the widthwise region of the developer carrier increases. effective. Then, there is an effect that the scattering of the developer can be more surely prevented.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a developing device according to an embodiment.

FIG. 2 is an upper sectional view of the developing device.

FIG. 3 is a schematic configuration diagram of a thin layer blade.

FIG. 4 is an explanatory view showing a state in which the abdomen contact portion of the thin layer blade is pressed against the developing roller.

FIG. 5 is an explanatory view showing a state where the edge contact portion of the thin layer blade is pressed against the developing roller.

FIG. 6 is a schematic configuration diagram of a thin layer blade according to another embodiment.

FIG. 7A is an explanatory view showing a mounting position of a reinforcing member. (B) is a schematic block diagram of a reinforcing member. (C) is a schematic block diagram of another reinforcement member.

FIG. 8 is a schematic configuration diagram of a thin layer blade according to another embodiment.

FIG. 9 is an explanatory view showing a state where the edge contact portion of the thin layer blade is pressed against the developing roller.

[Explanation of symbols]

 6 Developing Roller 7 Sponge Roller 17 Thin Layer Blade 17a Abdominal Resting Part 17b Edge Resting Part 17e Notch 17f Convex Part 171 Reinforcing Member 172 Reinforcing Member 100 Photoreceptor Drum

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiromitsu Takagaki 1-3-6 Nakamagome, Ota-ku, Tokyo Stock company Ricoh Co., Ltd. (72) Ichiro Komuro 1-3-6 Nakamagome, Ota-ku, Tokyo Shares In Ricoh Company (72) Inventor Shigeki Sawa 1-3-6 Nakamagome, Ota-ku, Tokyo Stock Company Ricoh (72) Inventor Kazuhiro Nishichi 1-3-6 Nakamagome, Ota-ku, Tokyo Stock Company Ricoh ( 72) Inventor Naoki Iwata 1-3-6 Nakamagome, Ota-ku, Tokyo Within Ricoh Co., Ltd.

Claims (4)

[Claims] 1. A developer carrying member carrying a developer on a surface thereof and conveying it to a portion facing an image carrying member, a developer supplying means for supplying the developer to the developer carrying member, and the developer carrying member. A developing device having a developer layer regulating member that presses against the surface of the body and regulates the layer thickness of the developer supplied to the developer carrier, wherein the developer layer regulating member is at least on the image carrier. The abdomen contact portion whose abdominal surface is in pressure contact with the widthwise area of the developer bearing body facing the image area of, and the widthwise area of the developer bearing body facing the non-image area of the image bearing body. And an edge contact portion with which the edge portion is in pressure contact, and an outer end portion in the width direction of the edge contact portion coincides with the outer end portion in the width direction of the developer carrier, or extends to the outside. A developing device having the above structure. 2. The developing device according to claim 1, wherein a notch is provided at a boundary between the abdomen contact portion and the edge contact portion on the free end side of the developer layer restriction member. 3. The developing device according to claim 1, wherein a reinforcing member is attached to the edge contact portion of the developer layer restriction member. 4. The developing device according to claim 1, wherein a convex portion is provided on the free end side of the edge abutting portion of the developer layer regulating member, the edge portion being in pressure contact with the developer carrying member.