JP2008090160A - Developer amount regulating blade and developing device using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a developer amount regulating blade by which a developer film on a developer carrier can be uniformly formed with a proper thickness by securing a specified toner intake port between the developer amount regulating blade and the developer carrier and uniformizing the contact pressure of the developer amount regulating blade with the developer carrier and further, image defects such as stripes and non-uniformity can be suppressed by suppressing developer, especially toner particles for color from being fused to the charging surface of the developer amount regulating blade. <P>SOLUTION: The developer amount regulating blade 13 regulates the amount of the developer conveyed out of a developer container 14 by the developer carrier 15 and has a support member 12 and a blade member 10. The blade member is composed of a coating film 11 which is formed on the support member having a contact support surface 12a for supporting an abutting surface with the developer carrier and is made of resin or elastomer as a main material, and is configured so that the coating film covers the support member 12 from the contact support surface 12a to a top end surface 12c. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a developer amount regulating blade for regulating the amount of developer used to develop and visualize an electrostatic latent image formed on an image carrier such as an electrophotographic apparatus, and the developer amount regulation. The present invention relates to a developing device equipped with a blade.

  Conventionally, a developing device is provided in an image forming apparatus of an electrophotographic apparatus such as an electrophotographic copying machine, a laser beam printer, and a facsimile. The developing device mainly includes a roller-shaped developer carrier disposed so as to close the opening of a developer container that accommodates a developer (also referred to as toner) and expose a part thereof, and the developer carrier. A developer amount regulating blade that is disposed in contact with the surface and that makes a constant amount of developer conveyed by the developer carrying member is provided. When the developer adhering to the surface of the developer carrying member passes between the developer amount regulating blades as the developer carrying member rotates, the excess portion is removed from the surface of the developer carrying member, and the developer container is removed. And formed as a thin layer on the developer carrying member. At the same time, the developer is given a triboelectric charge (also referred to as tribo) by friction with the developer amount regulating blade, and the developer carrier is exposed to the developer carrier at the portion exposed from the developer container. Then, it moves onto the electrostatic latent image on the surface of the rotating electrophotographic photosensitive member.

  As such a developer amount regulating blade, a blade having a blade member pressed against the developer carrying member and a support member for supporting the blade member at a predetermined position is used. As such a developer amount regulating blade, a configuration in which a rubber-like elastic plate-like blade member is bonded to a predetermined position of a metal support member with an adhesive, a uniform pressure contact force over the entire length of the developer carrier. It is easily used for pressure contact, and is often used because it has durability. The surface of the blade member that is in contact with or pressed against the developer carrying member has a function of controlling the frictional charge of the developer, and is also called a charge control surface. In such a blade member, as the material for the charge control surface, for example, urethane rubber, urethane resin, polyamide elastomer or the like is used for negative toner, and silicone rubber or the like is used for positive developer. It has been.

  Furthermore, the charge control surface for the non-magnetic toner used for forming a color image gives the toner a high frictional charge because the toner itself does not have magnetism, and enables the formation of a thin film on the developer carrier. It is required to do. As a material for such a charge control surface, urethane rubber, polyamide resin, polyamide elastomer, silicone rubber, silicone resin or the like is used, and the charge control surface is finished with high surface accuracy.

  In recent years, high-quality and full-color developing devices applied to electrophotographic processes use fine particle toner, so that a developer amount regulating blade capable of more uniform pressure contact with the developer carrier Is required. For this reason, a developer amount regulating blade having a configuration in which a blade member, an adhesive, and a support member are stacked so as to form a layer having substantially the same shape and the entire surfaces just overlapping each other has been reported (Patent Document 1). ). Furthermore, the blade tip shape of the developer amount regulating blade is formed, the first inclined surface is formed at the edge formed by the sliding surface and the end surface, and the edge formed by the bonding surface and the end surface of the blade member with the support member A blade having a shape with a second slope is reported (Patent Documents 2 and 3). According to such a blade, even in a color copying machine and a color laser beam printer that are intended to increase speed and durability, it is effective to fuse color toner particles to the charge imparting surface of the developer amount regulating blade. Can be suppressed.

However, in recent electrophotographic processes, it is required that a proper amount of toner is more uniformly pressure-bonded to a developer carrying member in a developing device with higher image quality, higher speed, and higher durability. Even when the developer amount regulating blade disclosed in the above Patent Documents 2 and 3 is adopted, in a color toner developing device that achieves high image quality and high speed, it is possible to uniformly press the toner while regulating the toner to an appropriate amount. Is difficult. There is a need for a developer amount regulating blade capable of suppressing the fusion of color toner particles to the charge imparting surface even when a finer toner is used.
JP 2002-372858 A JP 2002-372854 A JP 2002-372855 A

  The object of the present invention is to ensure a constant toner intake port between the developer carrier and uniform contact pressure with the developer carrier, so that the developer film on the developer carrier is properly aligned. An object of the present invention is to provide a developer amount regulating blade that can be uniformly and thickly formed.

  It is another object of the present invention to provide a developer amount regulating blade capable of suppressing the fusion of developer, particularly color toner particles, to the charge imparting surface and suppressing image defects such as streaks and unevenness.

  Another object of the present invention is to provide a developing device that includes such a developer amount regulating blade and that can suppress image defects such as streaks and unevenness due to the developer.

  The present invention relates to a developer amount regulating blade having at least a support member and a blade member that regulates the amount of developer carried out of the developer container by the developer carrier, and the blade member is in contact with the developer carrier. A coating mainly composed of a resin or an elastomer formed on a support member having a contact support surface for supporting the contact surface, and the coating covers the support member from at least the contact support surface to the tip surface. The developer amount regulating blade is characterized in that

  According to the present invention, in the developing device used to visualize the electrostatic latent image formed on the image carrier, the developer amount regulating blade according to any one of claims 1 to 8 is mounted. The present invention relates to a developing device.

  The developer amount regulating blade of the present invention secures a constant toner intake port between the developer carrying member and makes the contact pressure with the developer carrying member uniform, thereby developing the developer on the developer carrying member. The agent film can be formed to an appropriate thickness and uniformly. Further, it is possible to suppress the fusion of developer, particularly color toner particles, to the charge imparting surface, and to suppress image defects such as streaks and unevenness.

  The developing device of the present invention can suppress image defects such as streaks and unevenness due to the developer by providing the developer amount regulating blade.

  The developer amount regulating blade of the present invention has at least a support member and a blade member that regulate the amount of the developer carried out from the developer container by the developer carrier.

  The support member used for the developer amount regulating blade has a contact support surface that supports the contact surface with the developer carrying member, and is particularly limited as long as it can support the coating film as the blade member. It is not a thing.

  The material of the support member may be any of metal, resin, and the like. Specifically, examples thereof include metals such as stainless steel, phosphor bronze, and aluminum, and resins such as polyethylene terephthalate, acrylic, polyethylene, and polyester. it can. A conductive material can be added to such a resin in order to have a desired charging property.

  The shape of the support member is preferably a flat plate shape having a contact support surface or a curved plate shape obtained by bending the support member to support the blade member that contacts the developer carrier.

  The thickness of the support member is preferably 0.05 mm or more and 0.15 mm or less. If the thickness of the support member is 0.05 mm or more, the blade member can be brought into contact with the developer carrying member with an appropriate contact pressure, and the toner particles can be pressed against the developer carrying member with a necessary pressure. . On the other hand, if the thickness of the support member is 0.15 mm or less, the blade member can be easily followed by the developer carrying member and has a spring property to apply a necessary pressure to the developer particles.

  The blade member used for the developer amount regulating blade is made of a coating mainly composed of a resin or elastomer formed on a support member having a contact support surface that supports a contact surface with the developer carrier. The coating covers the support member from at least the abutting support surface to the tip surface. By forming the coating so as to cover not only the contact support surface of the support member but also the contact support surface to the front end surface, a constant toner intake port is secured between the developer carrier and the developer. The amount of toner on the carrier can be made appropriate and uniform. Further, the coating includes a corner (edge) where the abutting support surface and the tip surface intersect, and having no inflection point facilitates toner uptake, and a toner film having a uniform thickness on the developer carrier. Can be formed.

  Furthermore, it is preferable that the coating is also formed on the back surface of the support member that faces the contact support surface. By forming the coating on the back surface of the support member, deformation of the support member is suppressed, and the developer amount regulating blade can be brought into pressure contact with the developer carrying member with a uniform pressure contact force over the entire length. it can.

  The thickness of the coating is preferably 10 μm or more and 500 μm or less on the contact support surface of the support member. If the thickness of the coating on the abutting support surface of the support member is 10 μm or more, it is possible to suppress wear due to friction with the developer carrying member and lower durability, and if it is 500 μm or less, A stable contact pressure with the developer carrying member can be obtained. Moreover, it is preferable that they are 5 micrometers or more and 600 micrometers or less on the front end surface of a supporting member. If the thickness of the coating on the front end surface of the support member is 5 μm or more, it is possible to suppress a decrease in durability, and if it is 600 μm or less, a toner film having a stable thickness on the developer carrying member. Can be formed.

  The material of the coating can be selected depending on the toner type, particle diameter and the like, and is preferably a material having good toner chargeability. Specifically, a material having a high charge imparting property to the toner can be selected from polyamide, polyamide elastomer, polyester, polyester elastomer, polyester terephthalate, polyurethane, silicone rubber, silicone resin, melamine resin, and the like. These can be used alone or in combination of two or more. Further, an additive such as a conductive material can be added to these elastomers and resin materials in order to impart a predetermined charging property to the toner. Examples of the conductive agent material include carbon black and metal materials.

  Furthermore, the coating film can contain additives such as a charge-imparting agent and roughening particles as necessary.

  The coating film preferably has a surface roughness of 0.1 μm or more and 3.0 μm or less as a ten-point roughness average (Rz) at least on the contact surface with the developer carrying member. If the surface roughness of the coating is 0.1 μm or more, fine scratches and irregularities on the coating surface can be prevented from affecting the image, and if it is 3.0 μm or less, on the developer carrying member. In addition, a uniform developer layer in which streaks and unevenness are suppressed can be formed.

  Here, as the ten-point roughness average (Rz) of the surface roughness, a measured value measured by a contact-type surface roughness meter according to JIS B0601 can be adopted.

  Such a film is preferably formed on the support member via an adhesive layer. The adhesive layer can strengthen the bonding between the support member and the coating and can improve the durability of the developer amount regulating blade. Examples of the material of the adhesive layer include, for example, a hot melt type, a polyurethane type, a polyester type, an ethylene vinyl alcohol type (EVA type), and a polyamide type.

  The coating can be formed by extrusion molding, coating molding, sheet lamination molding, or the like. Specifically, in the case of extrusion molding, if necessary, a support member coated with an adhesive is placed in a mold, and the uncured elastomer or resin composition is injected into a molding cavity and heated and cured. In the case of the coating method, a coating solution containing the uncured elastomer or resin is prepared, a coating film is formed on the support member by dipping, coating, spraying, or the like, and heated and cured as appropriate. In addition, in the case of sheet lamination molding, the elastomer or resin composition formed into a sheet shape by extrusion molding or the like is bonded to a support member coated with an adhesive.

  Specific examples of the developer amount regulating blade created using the support member and the blade member include those shown in FIGS. 1 and 2. The developer amount regulating blade 13 shown in FIG. 1 includes a support member 12 and a blade member 10 including an adhesive 11. The blade member 10 includes an angle (edge) 12b where the abutting support surface 12a of the support member 12 and the tip end surface 12c intersect, and is formed as a coating that integrally covers the tip end surface 12c from the abutting support surface 12a. . Such a developer amount regulating blade 13 is fixed to the developer container 14 and presses the surface of the developer carrying member with a pressing force F with a fixing point 16 in contact with the opening end of the developer container as a fulcrum. Yes. By having such a configuration, the developer amount regulating blade 13 can form a take-in port for introducing an appropriate amount of toner particles between the developer carrier and a uniform and sufficient amount on the developer carrier. A charge amount developer layer can be formed.

  The developer amount regulating blade 23 shown in FIG. 2 includes a support member 22 and a blade member 20 including an adhesive 21. The blade member 20 includes a corner (edge) 22b between the contact support surface 22a and the front end surface 22c of the support member 22, and is formed as a coating that integrally covers the front end surface 22c and the back surface 22d from the contact support surface 22a. ing. For example, as shown in FIG. 3, the thickness of the coating is 10 μm or more and 500 μm or less as the thickness T on the contact support surface 22a and the back surface 22d of the support member, and the thickness L on the tip surface 22c. As a range from 5 μm to 600 μm.

  Such a developer amount regulating blade 23 is fixed to the developing container 14 and presses the surface of the developer carrying member with a pressing force F with a fixing point 26 in contact with the opening end of the developing container as a fulcrum. By having such a configuration, the developer amount regulating blade forms a uniform and sufficient charge amount developer layer on the developer carrying member, and further suppresses the occurrence of warpage of the support member. it can.

  The developing device of the present invention uses the developer amount regulating blade. An example is shown in FIG. In the developing device shown in FIG. 4, a developer container 42 containing a one-component developer 46, an elastic roller 45 and a developer carrier 43 are rotatably provided therein, and the elastic roller 45 is a developer. The carrier is arranged with a nip width. The developer carrier 43 is provided so that the half-peripheral surface is exposed in the developer container 42 and the other half-peripheral surface is exposed outside the developer container 42 so as to close the opening of the developer container 42. In the exposed portion, the photoconductor 41 that is an image carrier is disposed to face the photoconductor 41 with a small gap. The developer carrying member can be moved by a moving unit that finely adjusts the interval between the developer carrying member and the developer on the developer carrying member to the photoreceptor. Further, a developer amount regulating blade 44 of the present invention is provided fixed to the opening end of the developer container 42 so as to contact the developer carrying member.

  In such a developing device, the elastic roller 45 rotates in the direction of the arrow c and is pressed onto the developer carrier 43 that rotates in the direction b. When the developer pressure-bonded on the developer carrier enters the developer amount regulating blade 44 and the developer carrier 43 as the developer carrier 43 rotates in the b direction, The surface of the developer carrying member 43 and the blade member of the developer amount regulating blade are rubbed and frictionally charged. The charged developer is formed into a thin layer on the developer carrying member, and is transported out of the developer container as the developer carrying member rotates. The developer on the developer carrying member 43 moves and adheres to the electrostatic latent image on the photoconductor 41 rotating in the a direction, and develops and visualizes the electrostatic latent image as a toner image. The developer remaining on the developer carrying member 43 without being consumed in the development of the electrostatic latent image is collected into the developer container 42 from the lower portion of the developer carrying member with the rotation of the developer carrying member 43, and the elastic roller 45. Is peeled off from the developer carrier 43 at the nip portion. At the same time, a new developer in the developer container is supplied onto the developer carrier 43 by the rotation of the elastic roller 45, and the new developer passes between the developer amount regulating blades and is conveyed to the photoreceptor. On the other hand, most of the developer peeled off from the developer carrying member is conveyed and mixed in the developer in the developer container 42 as the elastic roller 45 rotates, and the charged charge is dispersed.

  Examples of the electrophotographic apparatus to which such a developing device is applied include a copying machine, a laser beam printer, an LED printer, or an electrophotographic application apparatus such as an electrophotographic plate making system.

Hereinafter, the developer amount regulating blade of the present invention will be described in detail, but the technical scope of the present invention is not limited thereto.
[Examples 1 to 3]
[Production of developer regulating blade]
As the support member, a special mold having a phosphor bronze sheet (made by Harada Shindoh Co., Ltd.) having a thickness of 0.1 mm and a rectangular forming port having an extrusion port shape of 10 mm × 0.5 mm as shown in FIG. It was inserted into the used extrusion molding machine (Pura Giken Co., Ltd.). As a raw material of the blade member, a polyamide elastomer having a Shore D hardness of 40 ° specified by JIS D6253 (manufactured by Daicel Degussa Co., Ltd .: Daiamide E40) was melted at 200 to 270 ° C. While running, it was sequentially injected into the molding cavity. The polyamide elastomer was solidified, and the support member and the blade member were integrated to obtain a developer amount regulating blade sheet having a coating formed on the contact support surface and the tip surface of the support member shown in FIG. The film thickness of the blade member on the support member was adjusted by changing the extrusion amount of the resin and the feeding speed of the phosphor bronze sheet. The obtained developer amount regulating blade sheet was press-cut into blade dimensions of 200 mm in length and 23 mm in width to obtain samples of developer amount regulating blades (Examples 1 to 3).

  The ten-point roughness average (Rz) of the blade member surface of this blade sheet was measured by a contact-type surface roughness meter according to JIS B0601, and found to be 0.3 μm.

[Evaluation of image by developer amount regulating blade]
Next, the sample of the obtained developer amount regulation blade is mounted on a laser beam printer (Canon: Satera) instead of the used developer amount regulation blade, and is in an environment of normal temperature and humidity (temperature 23 ° C.). The solid black image was output at a humidity of 50%. Streaks and unevenness in the output image were observed, and the uniformity and appropriateness of the developer amount regulation of the samples were evaluated according to the following criteria. The results are shown in Table 1.
[Streak]
No streaks are observed (○), streaks are hardly observed (△), streaks are confirmed (×)
[village]
There is a sufficient concentration (◯), the concentration is somewhat insufficient (Δ), and the concentration is insufficient (×).

[Examples 4 and 5]
Other than using a polyester elastomer (Toray DuPont: Hytrel) with a Shore D hardness of 40 ° specified in JIS D6253 as a raw material for the blade member, instead of a polyamide elastomer (Daicel Degussa: Daiamide E40) A developer regulating blade was produced in the same manner as in Example 1. The 10-point roughness average (Rz) of the obtained blade member surface was 0.3 μm.

  The obtained developer amount regulating blade was subjected to image evaluation in the same manner as in Example 1. The results are shown in Table 1.

[Comparative Example 1]
Without preparing the blade member, a developer amount regulating blade was prepared using the same support member as in Example 1. The surface roughness of the developer amount regulating blade was 0.7 μm.

  The obtained developer amount regulating blade was subjected to image evaluation in the same manner as in Example 1. The results are shown in Table 1.

[Comparative Examples 2 and 3]
Without using a surface transfer sheet, the blade member material used in Example 1 was injection-molded into a mold having a mirror surface (Rz = 0.2 μm) and a temperature of 40 ° C., and was 5 mm wide and 900 μm thick. A plate-like molded product was prepared. This plate-like molded product was fixed to a phosphor bronze sheet having a thickness of 0.1 mm (manufactured by Harada Shindohsho Co., Ltd.) to produce a developer amount regulating blade having a length of 200 mm in the longitudinal direction and a width of 23 mm. The ten-point average roughness (Rzjis) of the surface of the obtained developer amount regulating blade was 0.3 m. Image evaluation was performed in the same manner as in Example 1. The results are shown in Table 1.

  As is apparent from the results, it is clear that the developer amount regulating blade of the present invention can obtain an image with suppressed streaks and unevenness, and can form the developer on the developer carrying member in an appropriate amount and uniformly. It was.

It is a schematic block diagram which shows an example of the developer amount regulation blade of this invention. It is a schematic block diagram which shows the other example of the developer amount regulation blade of this invention. It is a schematic block diagram which shows the other example of the developer amount regulation blade of this invention. It is a schematic block diagram which shows an example of the image development apparatus of this invention. It is a schematic block diagram which shows the manufacturing apparatus of the developer amount regulation blade of this invention.

Explanation of symbols

10, 20 Blade member (coating)
11, 21 Adhesive member 12, 22 Support member 12a, 22a Contact support surface 12b, 22b Corner (edge)
12c, 22c Front end surface 22d Back surface 13, 23, 44 Developer amount regulating blade 14, 42 Developer container 15, 43 Developer carrier 16, 26 Fixed point 16 Developer 41 Photoconductor (image carrier)
45 Elastic roller 46 Developer 51 Special mold 52 Molding port F Pressing force L of developer amount regulating blade to developer carrier L Film thickness on tip surface T Film thickness on contact support surface

Claims (9)

In a developer amount regulating blade having at least a support member and a blade member for regulating the amount of developer carried out from the developer container by the developer carrier,
The blade member is made of a coating mainly composed of a resin or an elastomer formed on a supporting member having an abutting supporting surface for supporting an abutting surface with the developer carrying member, and the coating at least contacts the supporting member. A developer amount regulating blade characterized by being coated from the support surface to the tip surface.   2. The developer amount regulating blade according to claim 1, wherein a thickness of the coating on a front end surface of the support member is 5 μm or more and 600 μm or less.   3. The developer amount regulating blade according to claim 1, wherein a thickness of the coating on a contact support surface of the support member is 10 μm or more and 500 μm or less.   The developer amount regulating blade according to claim 1, wherein the coating does not have an inflection point.   5. The film according to claim 1, wherein the coating has a ten-point roughness average (Rz) of 0.1 μm or more and 3.0 μm or less at least on a contact surface with the developer carrying member. The developer amount regulating blade according to any one of the above.   6. The film according to claim 1, wherein the coating film includes one or more selected from polyamide, polyamide elastomer, polyester, polyester elastomer, polyester terephthalate, polyurethane, silicone rubber, silicone resin, and melamine resin. Developer amount regulating blade.   7. The developer amount regulating blade according to claim 1, wherein the blade member has a coating formed on the back surface facing the abutting support surface of the support member.   The developer amount regulating blade according to claim 1, wherein the blade member is formed on the support member via an adhesive layer.   9. A developing device used for visualizing an electrostatic latent image formed on an image carrier, wherein the developer amount regulating blade according to claim 1 is mounted. .

Images