JP2001350341A - Developer layer thickness regulating blade, its manufacturing method and image forming device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a very reliable non-magnetic one-component developing device by forming a circular-arc-shaped curved surface part having specified dimension at a part being the tip of a toner layer thickness regulating blade by press, reducing the manufacturing man-hour of the blade and stabilizing image quality. SOLUTION: In the manufacturing method of the blade, the inside of the edge part of a plate-shaped metallic elastic member being the blade is coining- worked by a press metallic mold so as to form the circular-arc-shaped curved surface part having the specified dimension at the part being the tip of the toner layer thickness regulating blade. Thereafter, by cutting the edge part of the metallic elastic member being the thickness relief part at the time of coining work, a blade end face consisting of the curved surface part and a cut surface part is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blade for controlling the thickness of a developer layer on a developing roller, a method for manufacturing the same, and a method for forming a latent image carrier on a latent image carrier using, for example, a one-component developer. The present invention relates to an image forming apparatus for visualizing an electrostatic latent image, such as non-magnetic one-component development.

[0002]

2. Description of the Related Art In an electrophotographic image forming apparatus such as a facsimile machine, a copying machine or a laser printer, a photosensitive drum is charged by a charger, and an electrostatic latent image is formed on the photosensitive drum by light irradiation. After the development, a process of transferring the image to recording paper and fixing it is used. on the other hand,
After the transfer, the photosensitive drum is subjected to static elimination, and the residual toner is cleaned by a cleaner to prepare for the next printing.

In particular, in a developing process using a one-component developer, it is necessary to once deposit a developer consisting of toner only on the developing roller in a uniform layer in the axial direction. Therefore, the developer layer is opposed to the developing roller. It is common to arrange a regulating blade. Since the processing accuracy of the tip portion (edge) directly affects the quality of the layer thickness regulating blade, a conventional blade having a tip portion processed into a smooth arcuate curved surface portion is used in the conventional blade.

[0004] The method of manufacturing the blade described above is as follows.
In the first step, a flat metal elastic member is punched out by a press, and in the second step, the tip of the blade that contacts the developing roller is polished by buffing to finish the arc-shaped curved surface. Was.

Japanese Patent Application Laid-Open No. 9-62096, entitled "Developer Layer Thickness Control Blade, Method for Producing the Same, and Image Forming Apparatus Using the Same" discloses a method in which a gap between a press-type punch and a die is formed by punching a metal plate. When the punching member is punched out, the end of the punching member is set so that a punch sag having a smooth arc-shaped curved surface portion is generated, and the pressing roller is used to punch out a flat metal elastic member, thereby making contact with the developing roller. It is described that a smooth arcuate curved surface portion is formed at the blade tip portion by punching and sagging.

[0006]

In such a conventional manufacturing method, the buffing method requires a check by a microscope several times in the middle of the process to the completion of the finishing, so that the manufacturing time is long. I was

Further, in the method of forming a smooth arcuate curved surface portion R by punching described in Japanese Patent Application Laid-Open No. 9-62096, the mold is used when the member is changed or when the mold is used for a long time. Wear progressed, and the dimensions of the curved portion were not constant and varied.

As described above, when the blade manufactured by the conventional manufacturing method is incorporated in the developing device, unevenness in the thickness of the toner layer is likely to occur in the axial direction of the developing roller. In this case, there is a problem that the unevenness in the thickness of the toner layer deteriorates image quality.

The present invention solves the above-mentioned problems. An arc-shaped curved surface having a predetermined size is formed by pressing at a portion to be a tip of a toner layer thickness regulating blade, and the blade manufacturing man-hour is reduced. An object of the present invention is to provide a highly reliable non-magnetic one-component developing device which stabilizes image quality.

[0010]

According to the present invention, there is provided a method of manufacturing a blade for regulating the thickness of a developer layer on a developing roller, the method comprising the steps of: Is formed by coining with a press die to form an arc-shaped curved surface portion with a predetermined dimension at a portion to be the tip of the toner layer thickness regulating blade, and thereafter, the metal elasticity which has become a flesh relief portion during the coining process A method for manufacturing a developer layer thickness regulating blade, characterized in that an edge portion of a member is cut to form a blade end surface comprising the curved surface portion and the cut surface portion, and a developer layer thickness on a developing roller. An image forming apparatus provided with a blade for regulating the pressure, wherein the blade is formed by punching from a flat metal elastic member, and a blade tip portion in contact with the developing roller. , There is provided an image forming apparatus, characterized in that the smooth arcuate curved surface portion formed at a predetermined dimension in coining during the punching is formed.

Therefore, according to the present invention, an arc-shaped curved surface portion having a predetermined dimension can be press-formed at the leading end of the toner layer thickness regulating blade, thereby reducing the number of man-hours for manufacturing the blade and keeping the quality of the blade constant. In addition, it is possible to provide a highly reliable developing device that stabilizes image quality.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a blade for regulating the thickness of a developer according to the present invention and a method for producing the same will be described below with reference to the drawings.

FIG. 1 is a side view for explaining a method for manufacturing a layer thickness regulating blade of the present invention, FIG. 2 is a layout diagram for explaining a method for manufacturing a blade of the present invention, FIG. 3 is a side view showing a blade of the present invention, FIG. 4 is a side view showing an image forming apparatus for non-magnetic one-component development provided with the blade of the present invention.

In FIG. 1, reference numeral 24 denotes a blade in the course of manufacture formed by coining (crushing), 22 and 23 denote coining dies, and the upper die indicates a coining punch 22.
The lower die shows the die 23. Reference numeral 24 shown in FIG. 2 is a belt-shaped stainless steel plate having a thickness of 0.1 mm, which is a material of the blade of the present invention. 3 shown in FIG. 3 is a blade formed by the manufacturing method of the present invention.

In FIG. 1, the coining punch 22 of the coining die has a coining projection 27 having a radius of 0.05 mm and R0. A 14 mm curved surface is provided. The curved surface on the front side where the curved steel sheet is conveyed is a curved surface that forms a curved surface at the blade tip during crushing, and the other curved surface (blade tip side) is a concave portion 25 for flesh relief during coining. Form. The surface extending in the horizontal direction from the curved surface on the front side is provided with an opposing die 23 to prevent the blade surface during coining from being damaged.
Is provided with a 0.1 degree inclination angle 26 with respect to the horizontal plane.

On the other hand, the coining die 23 is
The surface of the coining punch 22 facing the curved surface of the blade tip portion is provided with a protrusion 28 of R0.08 mm for reducing stress during coining and uniformly plastically deforming the material.

The manufacturing method of the present invention for forming a curved surface at the tip of the blade using the coining mold will be described below.

As shown in the layout of FIG. 2, the method of manufacturing a blade according to the present invention is as follows. A roll-shaped stainless steel plate having a thickness of 0.1 mm, which is a material for the blade, is moved in the direction indicated by the arrow (from left to right). In a transfer device (not shown), pressing is performed for each process in each process while sending it onto a press die (not shown), and a rib is removed in the final process.
Create blades.

The order of production is as follows. First, in a first perforating step (piercing), a stainless steel plate is conveyed, and reference holes used for positioning with each press die are formed at both ends of the material. Next, in order to create the outer shape of the blade in the both-side outer shape removing step (slotting), first, the outer shape in the longitudinal direction is punched and formed by a press.

Next, a curved surface is formed by crushing (coining) the ends of the punched blades on both sides having the outer shape. Details will be described with reference to FIG.

As shown in FIG. 1, coining mold 2
A stainless steel plate 24 having both sides in the longitudinal direction punched out by a press is fed between the metal plates 2 and 23, and the stainless steel plate 24 is pressed.
8 is used as a fulcrum and pressed by the projection 27 of the punch 22,
As a result of plastic deformation, a part of the tip of the steel material escapes to the recess 25 for meat escape, and as shown in FIG. 1, the tip of the pressed steel material is narrowed in a curved line, and the thickness of the central portion is reduced. It becomes a thin shape.

Next, the steel sheet is sent to a finishing step (trimming), and the portion of the steel sheet whose thickness has been reduced by coining created in the above-mentioned crushing step is cut by a press die (not shown) into a shape shown in FIG. The toner layer thickness regulating blade is formed only by pressing.

Next, a mounting hole drilling step (piercing)
At the same time, several holes (four to six) are punched out to form a square hole to be attached to the developing machine, and then, in a rib making step (trimming), punching is performed while leaving only the rib portions at both ends in the longitudinal direction of the blade. The outer shape of the blade is almost completed, and finally, the rib is punched out by a press in a rib removing step (cutoff) and cut from a belt-shaped stainless steel plate to complete the blade.

Therefore, according to the above-described blade manufacturing method, an arcuate curved portion having a predetermined dimension can be formed at the tip of the toner layer thickness regulating blade, thereby reducing the number of man-hours for manufacturing the blade and reducing the shape of the curved portion. Quality can be stabilized by eliminating variations in

Further, since the coining punch 22 is provided with the relief having the inclination angle of 0.1 degree as described above, it is possible to press concentratedly on the curved surface portion, and the press is formed on the toner layer thickness regulation side of the blade surface at the time of press forming. It can prevent scratches and reduce crushing pressure.

Next, an image forming apparatus provided with the blade formed by the above-described manufacturing method will be described with reference to FIG.

In FIG. 4, reference numeral 1 denotes an OPC photosensitive drum which uniformly charges the surface of the photosensitive drum 1 using a pre-charging brush 13. The print information is irradiated on the photosensitive drum 1 according to the information by a laser scanning optical system (not shown) to form a latent image. The formed latent image is formed by a non-magnetic one-component developing device 6.

The non-magnetic one-component developing device 6 includes a developing roller 2,
It comprises a toner supply / recovery roller 3, toner 4 contained in a developing device frame 6a, a layer thickness regulating blade 5 also having a charging function, an agitator 7, a paddle 8, a toner bottle 9, and an outer 10. In the developing section, the developing roller 2 in contact with the photosensitive drum 1 rotates in the same direction at twice the peripheral speed of the photosensitive drum, and the toner 4 supplied from the roller 3 is formed into a thin layer toner by the blade 5, and this is formed. A visualized image is created by attaching it to the latent image portion of the photosensitive drum 1. The toner that has not contributed to the development is scraped off by the roller 3 rotating in the opposite direction below the developing roller 2, and is returned to the developing device 6 through the lower part of the roller 3.

On the other hand, the new toner is supplied to the developing roller 2 on the blade 5 side by the rotation of the roller 3, and is carried to the blade 5, and a thin layer toner having a specified layer thickness is formed on the surface of the developing roller 2 by the blade 5. Is done. To supply toner,
The toner swept out of the toner bottle 9 by the outer 10 is conveyed to the developing roller 4 side while being stirred by the agitator 7, and the toner is efficiently supplied to the roller 3 by the paddle 8.

The toner adhering to the photosensitive drum 1 is attracted to the sheet by the transfer roller 11 at the transfer section, is melted by the fixing device 12, and is fixed on the sheet.

As shown in FIG. 4, the end of the blade 5 is fixed to a developing device frame 6a made of an insulating resin using screws (not shown). And developing roller 2
The tip of the blade 5 is arranged in pressure contact with the surface of the developing roller 2 so as to face the sliding direction of the developing roller 2.

In the configuration of FIG. 4, the roller 3 is applied with a charge of -420 V and the developing roller 2 is applied with a charge of -320 V. The toner 4 carried by the rotation of the roller 3
The roller 3 is charged by charge injection and frictional charging with the developing roller 2 rotating in contact with the roller 3, and adheres to the surface of the developing roller 2. The adhered toner 4 on the developing roller 2 is further triboelectrically charged by the blade 5 and the developing roller 2 by pressing friction and charge injection by the rotation of the developing roller 2, and a uniform toner layer having a constant thickness. Is formed and passed. The blade 5 makes full use of the flexibility of the metal elastic member, which is a material, the pressing force against the developing roller 2 becomes appropriate, and the stress on the toner 4 is reduced.
The life of the toner 4 is extended and high image quality can be maintained.

As shown in FIG. 3, the height h of the curve r at the curved surface portion of the blade 5 is fixed to a predetermined dimension of 40 μm in the axial direction of the developing roller 2 so that the curve r
A gap is created between the height h of the developing roller and the developing roller 2, and the amount of toner taken in can be controlled. According to the present invention, the tip portion of the toner layer thickness regulating blade can be formed to have a predetermined dimension and an arc-shaped curved portion having the same dimension in the axial direction of the developing roller 2. It can be formed with a constant thickness.

Therefore, according to the image forming apparatus in which the above-described blade is incorporated in the developing machine, unevenness in the thickness of the toner layer is less likely to occur in the axial direction of the developing roller 2, and the thick portion of the toner layer becomes “fog”. The occurrence of density unevenness can be prevented, and high-reliability printing with stable image quality can be performed.

In the present embodiment, a non-magnetic one-component type developing apparatus which does not use a magnet as the developing roller 2 has been described. However, the present invention is not limited to the above-described embodiment. It goes without saying that many modifications and changes can be made to the above embodiment.

[0036]

According to the present invention described above, the curved surface shape at the blade tip can be formed with a predetermined dimension, the number of steps for manufacturing the blade can be reduced, and the quality can be stabilized by eliminating variations in the curved surface shape. In addition, the surface of the blade on the toner layer thickness regulation side can be prevented from being damaged, and the crushing pressure can be further reduced. In addition, it is possible to provide a toner layer thickness regulating blade and an image forming apparatus which are less likely to cause unevenness in the thickness of the toner layer in the axial direction of the developing roller and which can prevent occurrence of "fog".

[Brief description of the drawings]

FIG. 1 is a side view illustrating a method for manufacturing a blade according to the present invention.

FIG. 2 is a layout diagram for explaining a blade manufacturing method of the present invention.

FIG. 3 is a side view showing the blade of the present invention.

FIG. 4 is a side view showing a non-magnetic one-component developing image forming apparatus equipped with the blade of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Photosensitive drum 2 Developing roller 3 Toner supply / recovery roller 3 4 Toner 5 Blade (layer thickness regulating blade) 6 Non-magnetic one-component developing device 7 Agitator 8 Paddle 9 Toner bottle 10 Outer 11 Transfer roller 12 Fixing device 13 Pre-charging brush 22 Coining Punch 23 Die 24 Blade (blade during manufacture) 25 Recess 26 Relief 27 Projection 28 Projection

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H077 AB03 AB04 AD06 AD13 AD17 AD23 AD31 AD35 AE03 EA14 FA00 FA21

Claims (6)

[Claims] 1. A metal plate processing blade for regulating the thickness of a developer layer on a developing roller, wherein a tip of the blade is formed by crushing an end of the metal plate into a predetermined curved surface shape. Thickness regulating blade of developer. 2. The developer layer thickness regulating blade according to claim 1, wherein the blade has a recess for absorbing stress during crushing on a surface opposite to the curved surface. 3. The tip of the developer layer thickness regulating blade is characterized in that approximately half of the plate thickness is formed by a curved surface formed by the crushing process, and the remaining thickness is formed by a cut surface perpendicular to the plate surface. A blade for regulating the layer thickness of the developer according to claim 1. 4. A method of manufacturing a blade for controlling the thickness of a developer layer on a developing roller, wherein the inner side of the edge of a flat metal elastic member serving as a blade is coined with a press die to control the toner layer thickness. Form an arcuate curved surface with predetermined dimensions at the tip of the blade, and then
A layer thickness regulating blade for a developer, wherein an edge portion of the metal elastic member serving as a flesh relief portion during the coining process is cut to form a blade end surface including the curved surface portion and the cut surface portion. Manufacturing method. 5. A stamping die for coining is provided with a coining punch having a coining projection and a recess for flesh adjacent to the coining punch, and a stress at the time of coining is reduced on the opposing surface to achieve uniform plasticity. 5. The developer layer thickness regulating blade according to claim 4, comprising a coining die provided with a projection for deforming, wherein the flat metal elastic member is formed by pressing using the press die. Method. 6. An image forming apparatus provided with a blade for regulating a thickness of a developer layer on a developing roller, wherein the blade is formed by stamping from a flat metal elastic member, and is in contact with the developing roller. To the blade tip
An image forming apparatus, characterized in that a smooth arcuate curved surface formed with a predetermined size by coining at the time of the punching is formed.