JPH11249422A - Developer amount regulating elastic blade member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize high-quality development without having a vertical stripe by constituting an elastic blade so that the edge of a rubber elastic layer may be circular-arc shape to the tangent of a developing sleeve taking in developer and it may be obliquely formed at a specified angle from the center line of the sleeve from a vicinity where it comes into contact with the sleeve. SOLUTION: This developer amount regulating elastic blade member 4 is constituted so that the edge of the rubber elastic layer may be the circular-arc shape to the tangent of the developing sleeve 3 taking in the developer and it may be obliquely formed at an angle of 50 deg. to 70 deg. from the center line of the sleeve 3 from the vicinity where it comes in contact with the sleeve 3. The part of the member 4 coming in contact with the sleeve 3 is formed to be the circular-arc shape, so that regulating the developer to a thin film state and electrification property are univocally decided by the pressing pressure of the member 4. By angling from the circular-arc shape further, particles having different particle size easily flow from the circular-arc shape part to an angling direction when such particles come. Then, the cause of vertical stripe is eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus for developing an electrostatic latent image formed on an image carrier using a developer and visualizing the electrostatic latent image. It relates to the shape of the member.

[0002]

2. Description of the Related Art As a conventional image forming apparatus, as shown in FIG. 5, a developer carrying member 3 (hereinafter, referred to as a photoreceptor 1) provided with a minute interval between electrophotographic photosensitive members 1 and attached to a developer container 2 is provided.
It is called a developing sleeve. ), A developer amount regulating elastic member 4 (hereinafter, referred to as an elastic blade), an elastic roller 5, and a one-component developer 6 (hereinafter, referred to as a toner) are known. FIG. 3 is a schematic view of a conventional developing device.
As a means for regulating the layer thickness of the toner carried and transported by the developing sleeve 3 to the developing section to be a thin layer, as shown in FIG. 3, a rubber elastic layer 4b of an elastic blade 4 is brought into contact with the developing sleeve 3 and the developer is applied. The leading end of the elastic blade to be taken in is pressed against the developing sleeve so as to protrude from the developing sleeve, and toner is passed between the contact portion between the elastic blade 4 and the developing sleeve 3 to regulate the toner. And a method in which a triboelectric charge (triboelectric charge) for developing a latent image on the toner 6 is applied to the toner 6 by friction at a contact portion.

[0003] As such an elastic blade, besides a rubber plate or a metal thin plate, a resin thin plate or a plate obtained by integrating these by laminating, bonding or casting has been proposed.

For example, as a support layer, a charge-imparting layer such as silicone rubber or urethane rubber whose charge is controlled so as to wrap the entire surface or a part thereof in a stamped sheet metal of a rust-proofed steel plate or a metal foil such as stainless steel or phosphor bronze. Are laminated by bonding or casting.

[0005]

However, in the case of high image quality or full color application of an electrophotographic process, the particle size of the toner is further reduced, and the toner has a low melting point due to the fixability in full color. The development device requires uniform frictional charging of the toner and light pressure contact charging.However, the current amount of the lightened toner between the elastic blade member and the developing sleeve is restricted. Vertical stripes may be generated during thin layer coating, which has been a problem.

In a conventional developing device, as a means for regulating the layer thickness of the toner carried and conveyed by the developing sleeve to the developing section to a thin layer, the tip of the elastic blade is brought into contact with the developing sleeve to take in the developer. A thin layer of toner is formed on the developing sleeve by pressing it in such a manner as to protrude from the developing sleeve, and restricting the toner by passing it between the contact portions between the elastic blade and the developing sleeve. A method of applying a triboelectric charge (triboelectric charge) to develop a latent image on a toner by friction in a portion has been adopted, but light pressure and thinning are actually achieved by developing an elastic blade. The pressing force against the sleeve, the edge protrusion amount of the elastic blade, and the toner filling state between the blades when the developing sleeve rotates and the conveying force due to the respective frictional forces cancel each other out, Come thin layer coat weight is determined by the degree to which results to elastic blade is lifted upward.

That is, the amount of protrusion of the elastic blade from the point of contact with the developing sleeve, the pressing pressure of the elastic blade,
Further, it is determined from the respective friction coefficients between the toner of the developing sleeve and the elastic blade.

Therefore, in order to increase the charge amount, the pressure is controlled, and in order to increase the coating amount, the protrusion amount is increased. When such a setting is made, vertical streaks mean that if something larger than the toner particle size is mixed during development, it will be caught between the blade and sleeve and the toner flow around it will be hindered from there. The thin coat layer partially reduces toner,
When developed, it appears as a vertical streak. It is considered that the particles larger than the particle diameter of the toner are caused by crushing when the developing device is durable, fusion between the toners, and the like.

As described above, it is difficult to determine the arrangement of the elastic blade and the developing sleeve.

An object of the present invention is to provide a novel elastic developer amount regulating blade member which has solved the above-mentioned problems.

[0011]

The above object is achieved by the following means.

That is, the present invention relates to an elastic blade member for regulating the amount of developer in an image forming apparatus for developing and visualizing an electrostatic latent image formed on an image carrier using a developer, In a developer amount regulating elastic blade member in which a rubber elastic layer is formed as a charge imparting layer for controlling a charge amount so as to protrude further, an edge of the rubber elastic layer takes in a tangent of a developing sleeve to take in the developer. Characterized in that the blade is formed in an arc shape with respect to the developing sleeve, and is formed obliquely at an angle of 50 to 70 degrees from the center line of the sleeve from near the contact with the developing sleeve. It proposes a member.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail. FIG. 4 is a schematic view showing an example of the image forming apparatus of the present invention. In the present invention, in order to solve the above problems,
As shown in FIG. 4, the edge of the rubber elastic layer has an arc shape with respect to the tangent line of the developing sleeve 3 for taking in the developer, and has an angle of 50 degrees from the vicinity of the contact with the developing sleeve 3 from the center line of the sleeve 3. The invention has led to the invention of a developer amount regulating blade member characterized by being formed obliquely at an angle of 70 to 70 degrees.

By making the portion of the elastic blade 4 in contact with the developing sleeve 3 in an arc shape, it is possible to uniquely determine the thinning and charging properties by the pressing pressure of the elastic blade. By making the angle further, when particles having different particle diameters come, it becomes easier to flow from the arc-shaped part in the angled direction, and the cause of vertical stripes is eliminated.

As the silicone rubber used for the elastic blade 4, a rubber having a JISA hardness of 80 degrees or less is preferable, but from the viewpoint of reducing the development pressure, more preferably a rubber having a JISA hardness of 50 degrees is used.
It is more preferable that the temperature is not more than the degree. As a raw material of silicone rubber, when the whole is thin and long, such as an elastic blade, a two-liquid thermosetting type high-speed curing type LTV liquid silicone rubber having good fluidity and easy to perform injection molding is preferable. Is 1,000 Pa. s or less is good.

As the rust-proofing steel sheet of the support member, the higher the mold temperature at the time of molding, the lower the bonding strength between the iron and the plating layer of the support sheet metal. It is preferred that the adhesive strength is strong,
An alloy plating of zinc and nickel, such as zinc light steel plate (ZLC, etc.) of Nippon Steel, and an alloy plating of zinc and iron, such as silver alloy (ASHC, etc.) of Nippon Steel, are pressed and pressed by a high-temperature mold. It is also preferable because the iron and the plating layer do not peel off. The thickness of the rust-proofed steel sheet is 1.2 to 1.
6 mm is preferable from the viewpoint of strength and press workability.

In injection molding, a mixture of a silicone-based coupling agent, a titanium-based coupling agent, or a silicate agent is used as a primer for bonding the supporting metal plate and the rubber. As a method, the surface of the supporting sheet metal is thoroughly washed with a solvent, an appropriate amount of primer is applied to the bonded portion with a spray or a brush or a sponge, air-dried, baked at a temperature, and inserted into a mold. I do.

As the injection molding method, a material obtained by stirring a liquid silicone rubber raw material having two components of a main agent and a hardener containing a hardener component by a static stirrer such as a static mixer while transporting the raw material to an injection molding machine is used. Machine (L
(IM or LIMS molding machine), and the rubber is injected from the injection cylinder into a mold heated to a predetermined temperature by inserting a supporting metal plate in advance.
The mold temperature is from about 100 ° C. to about 220 ° C., and more preferably 150 ° C. or more from the viewpoint of shortening the molding time. From the viewpoint of preventing deformation and burr against the injection pressure, the injection pressure 10
0 kg / cm as the surface pressure at the time of pinching the type of supporting plate according from ² to 1000kg / cm ² 20kg / cm ² or more 200 kg / cm ^2-position is preferred.

[0019]

Next, an embodiment of the present invention will be described.

Example 1 A 1.6 mm zinc-nickel alloy plated steel sheet (ZLC-
C: Nippon Steel Corp.) The support plate obtained by bending into a square shape by pressing is thoroughly washed with a petroleum-based solvent, a primer for silicone rubber is applied by spraying, and then air-dried to 200 ° C.
Place the supporting sheet metal baked for 10 minutes in a mold having a mirror surface preheated to 200 ° C. (a part that comes into contact with the developing sleeve is engraved with a shape of r0.1), and place a gate on the other mold surface. A cold runner gate having a diameter of 1.5 mm is placed 15 mm from the longitudinal end of the supporting metal plate, and the pressing surface pressure of the supporting metal plate when the mold is tightened is 40 kg / cm ^2.
LTV silicone rubber (produced by Dow Corning Toray Co., Ltd.) having a JISA hardness of 42 degrees is injected with a two-liquid mixing type liquid silicone injection molding machine at an injection pressure of 500 kg.
/ Cm ² and removed from the mold after 40 seconds, 200
Heat treatment was performed at 4 ° C. for 4 hours.

This was cut so that the tip was at 50 degrees to obtain a developer amount regulating member as shown in FIG. Then, after passing 1000 sheets of the sheet into a laser beam printer at a pressing pressure of 100 g / cm ² in an acceleration test mode, vertical streaks were confirmed.

Example 2 Injection molding was performed according to Example 1. Put the tip 70
And cut it into a laser beam printer at an accelerated test mode of 100 g / cm ² at a pressure of 100 g / cm ² .
After passing 000 sheets, vertical streaks were confirmed.

The appearance was checked for the presence or absence of bubbles and the like and the surface assembly.

Comparative Example 1 Injection molding was performed according to Example 1. 90
Cutting was performed to obtain a developer amount regulating member having a shape as shown in FIG. Then, the blade edge was protruded by 1 mm, and a vertical streak was confirmed after 1000 sheets were passed through a laser beam printer at a pressing pressure of 100 g / cm ² in an acceleration test mode.

Comparative Example 2 Injection molding was performed according to Example 1. This is the tip 45
Then, the blade edge was protruded by 1 mm, and after 1000 sheets were passed through a laser beam printer at a pressing pressure of 100 g / cm ² in an acceleration test mode, vertical streaks were confirmed.

Comparative Example 3 Injection molding was performed according to Example 1. Put this on the tip
Then, the blade edge was protruded by 1 mm, and after 1000 sheets were passed through a laser beam printer at a pressing pressure of 100 g / cm ² in an acceleration test mode, vertical streaks were confirmed.

This was confirmed by the presence or absence of vertical stripes.

Table 1 shows the results of the performance comparison between the elastic developer amount regulating blade members of the embodiment and the comparative example.

[0029]

[Table 1] As is clear from the table, Examples 1 and 2 are considered to be good without vertical stripes.

On the other hand, in Comparative Example 1, many streaks were observed,
In Comparative Examples 2 and 3, it is considered that stripes were generated although they were slight, and particles larger than the particle size of the toner convected and caused a problem in the flow.

[0031]

As described above, the edge of the rubber elastic layer has an arc shape with respect to the tangent line of the developing sleeve for taking in the developer, and the angle from the center line of the sleeve from near the contact with the developing sleeve. By using an elastic blade formed obliquely at an angle of 50 to 70 degrees, the flow with a particle size larger than the toner can be regulated, and high-quality development without vertical stripes can be performed.

[Brief description of the drawings]

FIG. 1 is a schematic side view showing an example of a shape of a developer amount regulating elastic blade member of the present invention.

FIG. 2 is an explanatory view showing the shape of a conventional elastic developer amount regulating blade member.

FIG. 3 is a schematic view of a conventional developing device.

FIG. 4 is a schematic diagram of an image forming apparatus of the present invention.

FIG. 5 is a detailed view of a conventional image forming apparatus.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 electrophotographic photoreceptor 2 developer storage container 3 developing sleeve 4 developer amount regulating elastic blade member 4 a support metal plate 4 b rubber elastic layer 5 elastic roller 6 one-component developer (toner)

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Kenichi Sakai 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc.

Claims (1)

[Claims] 1. An image forming apparatus for developing an electrostatic latent image formed on an image carrier using a developer to visualize the electrostatic latent image, comprising an elastic blade member for regulating an amount of the developer, the elastic blade member being joined to a support member. In a developer amount regulating elastic blade member in which a rubber elastic layer is formed as a charge imparting layer for regulating a charge amount so as to protrude further, an edge of the rubber elastic layer is circular with respect to a tangent to a developing sleeve for taking in the developer. A developer amount regulating blade member having an arc shape and being formed obliquely at an angle of 50 to 70 degrees from the center line of the sleeve from near the contact with the developing sleeve.