JP2006084550A - Developing apparatus, image forming apparatus and system, electrifying member, and manufacturing method of developing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress the occurrence of fogging by appropriately electrifying a developer carried on a developer carrier. <P>SOLUTION: This developing apparatus comprises the developer carrier (a developing roller 510) for carrying the developer; a first layer 561 which is in contact with the developer carrier and which contains a conductive agent (carbon black CB); and a second layer 562 which is located at an opposite side to the developer carrier 510 when seen from the first layer 561 and which contains a conductive agent CB having larger density than that of the conductive agent contained in the first layer 561. Further the developing apparatus has an electrifying member (a regulation blade 560) for electrifying the developer carried on the developer carrier. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to a developing device, an image forming apparatus, an image forming system, a charging member, and a method for manufacturing the developing device.

  Image forming apparatuses such as laser beam printers are already well known. Such an image forming apparatus has, for example, an image carrier for carrying a latent image and a developing device for developing the latent image carried on the image carrier by a developer. When an image signal or the like is transmitted from an external device such as a host computer, the image forming apparatus positions the developing device at a developing position facing the image carrier, and the latent image carried on the image carrier is transferred to the developing device. A developer image is formed by developing with the developer inside, and the developer image is transferred to a medium, and finally an image is formed on the medium.

The developing device includes, for example, a developer carrying member for carrying a developer, and a charging member for contacting the developer carrying member and charging the developer carried on the developer carrying member. Have.
JP 2000-214659 A

The charging member includes a conductive agent in order to have conductivity. In order to charge the developer carried on the developer carrying member to a desired charge amount, it is necessary that a sufficient amount of conductive agent as a whole is dispersed in the charging member.
On the other hand, paying attention to the contact portion of the charging member with the developer carrying member, as the use of the developing device proceeds, the surface in contact with the developer carrying member is scraped and the conductive agent is exposed. In such a case, when the developer comes into contact with the exposed conductive agent, a decrease in the charge amount of the developer is promoted. If the charge amount of the developer is too low, a developer having a small charge amount is carried on the developer carrying member, and there is a risk of fogging.
This invention is made | formed in view of this subject, and is suppressing generation | occurrence | production of fogging.

  In order to solve the above-described problems, the main present invention includes a developer carrying member for carrying a developer, a first layer in contact with the developer carrying member and containing a conductive agent, and the first layer. A second layer containing a conductive agent located on the opposite side of the developer carrier and having a density greater than that of the conductive agent contained in the first layer, and the developer carrier. And a charging member for charging the developer carried on the developing device.

  Other features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

  At least the following will be made clear by the description of the present specification and the accompanying drawings.

A developer carrier for carrying the developer, a first layer in contact with the developer carrier, containing a conductive agent, and the developer carrier as viewed from the first layer are located on the opposite side. And a second layer containing a conductive agent whose density is greater than that of the conductive agent contained in the first layer, and a charging member for charging the developer carried on the developer carrying member And a developing device.
According to such a developing device, it is possible to appropriately charge the developer carried on the developer carrying member, and thus it is possible to suppress the occurrence of fog.

Further, in this developing device, the charging member is molded by a centrifugal molding method in which the material of the charging member is poured into a hollow mold having an inner wall and the mold is rotated to mold the charging member. It is good.
In such a case, it is possible to easily obtain a charging member.

In the developing device, when the charging member is molded by the centrifugal molding method, the material of the first layer is poured into the mold, the mold is rotated, and then the material of the second layer May be poured into the mold to rotate the mold.
In this case, since the conductive agent is uniformly dispersed in the vicinity of the surface of the first layer that contacts the developer carrier, the developer carried on the developer carrier is uniformly charged. This makes it possible to suppress the generation of streaks.

In the developing device, the conductive agent may be carbon black.
Carbon black has a high cost merit, and furthermore, it is possible to maintain the conductivity appropriately even when the environment changes.

In the developing device, the first layer may include an ionic conductive agent.
In such a case, since the amount of the conductive agent (excluding the ionic conductive agent) can be reduced, the amount of the exposed conductive agent is reduced, and the reduction in the charge amount of the developer carried on the developer carrier is effective. Can be prevented. Therefore, when the first layer contains an ionic conductive agent, it is possible to effectively suppress the occurrence of fog.

A developer carrying member for carrying the developer; a first layer in contact with the developer carrying member; containing a conductive agent; and on the opposite side of the developer carrying member as viewed from the first layer. And a second layer containing a conductive agent whose density is higher than that of the conductive agent contained in the first layer, and for charging the developer carried on the developer carrier. A charging member;
The charging member is molded by a centrifugal molding method in which the material of the charging member is poured into a hollow mold having an inner wall, and the mold is rotated to mold the charging member.
When forming the charging member by the centrifugal molding method, the material of the first layer is poured into the mold, the mold is rotated, and then the material of the second layer is poured into the mold. Rotate,
The conductive agent is carbon black,
The developing device, wherein the first layer contains an ionic conductive agent.
According to such a developing device, the effect that it is possible to suppress the occurrence of fogging is most effectively achieved.

Further, an image carrier for carrying a latent image, and a developing device for developing the latent image carried on the image carrier, a developer carrier for carrying a developer, A first layer containing a conductive agent in contact with the developer carrying member and a conductive layer located on the opposite side of the developer carrying member from the first layer, the density of which is contained in the first layer And a second layer containing a conductive agent larger than the density of the developer, and a developing device having a charging member for charging the developer carried on the developer carrying member. Image forming apparatus.
According to such an image forming apparatus, the occurrence of fogging can be suppressed, and an image forming apparatus superior to the conventional one can be realized.

Furthermore, a computer and an image forming apparatus connectable to the computer, an image carrier for carrying a latent image, and a developing device for developing the latent image carried on the image carrier. A developer carrying body for carrying the developer, a first layer in contact with the developer carrying body and containing a conductive agent, and the side opposite to the developer carrying body as viewed from the first layer And a second layer containing a conductive agent whose density is higher than that of the conductive agent contained in the first layer, and for charging the developer carried on the developer carrier. An image forming system comprising: a developing device having a charging member;
According to such an image forming system, the occurrence of fogging can be suppressed, and an image forming system superior to the conventional one can be realized.

And a charging member for charging the developer carried on the developer carrying member, the first member being in contact with the developer carrying member and containing a conductive agent, and the development as viewed from the first layer. A charging member comprising: a second layer that is located on a side opposite to the agent carrier and includes a conductive agent having a density higher than that of the conductive agent contained in the first layer.
According to such a charging member, occurrence of fogging can be suppressed.

Furthermore, a developer carrying body for carrying the developer, a first layer containing a conductive agent, and a second containing a conductive agent whose density is higher than the density of the conductive agent contained in the first layer. And a charging member for charging the developer carried on the developer carrying member, wherein the material of the first layer is a hollow mold having an inner wall And the mold is rotated, and then the second layer material is poured into the mold and the mold is rotated, and the charging member is molded by a centrifugal molding method, and the molding is performed by the centrifugal molding method. Further, the first layer of the charging member is brought into contact with the developer carrier, and the second layer of the charging member is positioned on the side opposite to the developer carrier as viewed from the first layer. And a developing device manufacturing method comprising the steps of:
According to such a method for manufacturing a developing device, it is possible to suppress the generation of fog and the generation of streaks.

=== Overview of Image Forming Apparatus ===
Next, an outline of a laser beam printer (hereinafter also referred to as a printer) 10 as an example of the image forming apparatus will be described with reference to FIG. FIG. 1 is a diagram illustrating main components constituting the printer 10. In FIG. 1, the vertical direction is indicated by arrows. For example, the paper feed tray 92 is disposed at the lower part of the printer 10, and the fixing unit 90 is disposed at the upper part of the printer 10.

  As shown in FIG. 1, the printer 10 according to the present embodiment includes a charging unit 30, an exposure unit 40, a developing device holding unit 50, a primary transfer unit along the rotation direction of a photoconductor 20 as an example of an image carrier. It has a unit 60, an intermediate transfer body 70, and a cleaning unit 75, and further controls a secondary transfer unit 80, a fixing unit 90, a display unit 95 formed of a liquid crystal panel as a means for notifying a user, and these units. And a control unit 100 for controlling the operation as a printer.

  The photoreceptor 20 has a cylindrical conductive substrate and a photosensitive layer formed on the outer peripheral surface thereof, and is rotatable around a central axis. In the present embodiment, the photoreceptor 20 is indicated by an arrow in FIG. Rotate clockwise.

  The charging unit 30 is a device for charging the photoconductor 20, and the exposure unit 40 is a device for forming a latent image on the photoconductor 20 charged by irradiating a laser. The exposure unit 40 includes a semiconductor laser, a polygon mirror, an F-θ lens, and the like, and charges the modulated laser based on an image signal input from a host computer (not shown) such as a personal computer or a word processor. The irradiated photoconductor 20 is irradiated.

  The developing device holding unit 50 converts the latent image formed on the photoconductor 20 into toner T as an example of a developer contained in the developing device, that is, black (K) toner contained in the black developing device 51, For developing using magenta (M) toner stored in the magenta developing unit 53, cyan (C) toner stored in the cyan developing unit 52, and yellow (Y) toner stored in the yellow developing unit 54. Device.

  The developing device holding unit 50 rotates in a state where the four developing devices 51, 52, 53, and 54 as an example of a developing device are mounted, so that the four developing devices 51, 52, 53, and 54 It is possible to move the position. That is, the developing device holding unit 50 holds the four developing devices 51, 52, 53, and 54 by the four attaching / detaching portions 50a, 50b, 50c, and 50d, and the four developing devices 51, 52, and 53 are provided. , 54 are rotatable about the rotation axis 50e while maintaining their relative positions. Each time image formation for one page is completed, it is selectively opposed to the photoconductor 20 and is formed on the photoconductor 20 with the toner T accommodated in each of the developing devices 51, 52, 53, and 54. The latent images are sequentially developed. Each of the four developing devices 51, 52, 53, 54 described above can be attached to and detached from the attaching / detaching portion of the developing device holding unit 50. Details of each developer will be described later.

  The primary transfer unit 60 is a device for transferring a single color toner image formed on the photoconductor 20 to the intermediate transfer body 70. When four color toners are sequentially transferred in a superimposed manner, the full color toner is transferred to the intermediate transfer body 70. An image is formed. The intermediate transfer body 70 is an endless belt in which an aluminum vapor deposition layer is provided on the surface of a PET film and a semiconductive paint is formed on the surface layer and laminated. The intermediate transfer body 70 is driven to rotate at substantially the same peripheral speed as the photoconductor 20. The secondary transfer unit 80 is a device for transferring a single color toner image or a full color toner image formed on the intermediate transfer body 70 to a medium such as paper, film, or cloth.

  The fixing unit 90 is a device for fusing a single-color toner image or a full-color toner image transferred onto a medium to form a permanent image. The cleaning unit 75 is provided between the primary transfer unit 60 and the charging unit 30 and has a rubber cleaning blade 76 that is in contact with the surface of the photoconductor 20. The cleaning unit 75 is disposed on the intermediate transfer body 70 by the primary transfer unit 60. After the toner image is transferred, the toner T remaining on the photoconductor 20 is scraped off and removed by the cleaning blade 76.

As shown in FIG. 2, the control unit 100 includes a controller unit 101 and a unit control unit 102. An image signal and a control signal are input to the controller unit 101, and a command based on the image signal and the control signal is received. Then, the unit controller 102 controls the units and the like to form an image.
Next, the operation of the printer 10 configured as described above will be described.
First, when an image signal and a control signal from a host computer (not shown) are input to the controller unit 101 of the printer 10 via the interface (I / F) 112, the unit control unit 102 based on a command from the controller unit 101. The photosensitive member 20, the developing roller, and the intermediate transfer member 70 are rotated by this control. The photoconductor 20 is sequentially charged by the charging unit 30 at the charging position while rotating.

  The charged area of the photoconductor 20 reaches an exposure position as the photoconductor 20 rotates, and a latent image corresponding to image information of the first color, for example, yellow Y, is formed in the area by the exposure unit 40. . Further, in the developing device holding unit 50, the yellow developing device 54 containing yellow (Y) toner is located at the developing position facing the photoconductor 20. The latent image formed on the photoconductor 20 reaches the development position as the photoconductor 20 rotates, and is developed with yellow toner by the yellow developing device 54. As a result, a yellow toner image is formed on the photoreceptor 20.

  The yellow toner image formed on the photoconductor 20 reaches the primary transfer position as the photoconductor 20 rotates, and is transferred to the intermediate transfer body 70 by the primary transfer unit 60. At this time, a primary transfer voltage having a polarity opposite to the charging polarity of the toner T is applied to the primary transfer unit 60. During this time, the photosensitive member 20 and the intermediate transfer member 70 are in contact with each other, and the secondary transfer unit 80 is separated from the intermediate transfer member 70.

  The above processing is sequentially executed for each developing device for the second color, the third color, and the fourth color, so that four color toner images corresponding to the respective image signals are transferred to the intermediate transfer member 70. It is transcribed and superimposed. As a result, a full-color toner image is formed on the intermediate transfer member 70.

  The full color toner image formed on the intermediate transfer body 70 reaches the secondary transfer position as the intermediate transfer body 70 rotates, and is transferred to the medium by the secondary transfer unit 80. The medium is conveyed from the paper feed tray 92 to the secondary transfer unit 80 via the paper feed roller 94 and the registration roller 96. When performing the transfer operation, the secondary transfer unit 80 is pressed against the intermediate transfer body 70 and a secondary transfer voltage is applied.

  The full color toner image transferred to the medium is heated and pressed by the fixing unit 90 and fused to the medium. On the other hand, after the primary transfer position has passed, the photosensitive member 20 is scraped off by the cleaning blade 76 supported by the cleaning unit 75 and the toner T adhering to the surface thereof is charged to form the next latent image. Prepare for. The toner T thus scraped off is collected by a residual toner collecting unit provided in the cleaning unit 75.

=== Overview of Control Unit ===
Next, the configuration of the control unit 100 will be described with reference to FIG. The controller unit 101 of the control unit 100 is connected to a host computer via an interface 112 and includes an image memory 113 for storing an image signal input from the host computer. The unit controller 102 includes units of the apparatus main body (charging unit 30, exposure unit 40, developing device holding unit 50, primary transfer unit 60, cleaning unit 75, secondary transfer unit 80, fixing unit 90, and display unit 95). Each unit is controlled based on a signal input from the controller unit 101 while detecting a state of each unit by receiving signals from sensors that are electrically connected and provided.

=== Configuration Example of Developer ===
Next, a configuration example of the developing device will be described with reference to FIGS. 3, 4, 5A, and 5B. FIG. 3 is a conceptual diagram of the developing device. FIG. 4 is a cross-sectional view showing the main components of the developing device. FIG. 5A is a schematic view showing the periphery of the regulating blade 560. FIG. 5B is a schematic diagram illustrating a boundary portion (corresponding to a portion A in FIG. 5A) between the first layer 561 and the second layer 562. Note that the cross-sectional view shown in FIG. 4 represents a cross-section obtained by cutting the developing device along a plane perpendicular to the longitudinal direction shown in FIG. 4, the vertical direction is indicated by arrows as in FIG. 1. For example, the central axis of the developing roller 510 is below the central axis of the photoconductor 20. FIG. 4 shows a state where the yellow developing device 54 is located at a developing position facing the photoconductor 20.

  The developing device holding unit 50 includes a black developing device 51 containing black (K) toner, a magenta developing device 53 containing magenta (M) toner, a cyan developing device 52 containing cyan (C) toner, and yellow. (Y) Although the yellow developing unit 54 containing toner is provided, the configuration of each developing unit is the same, so the yellow developing unit 54 will be described below.

  The yellow developing device 54 includes a developing roller 510 as an example of a developer carrying member, a seal member 520, a toner container 530, a housing 540, a toner supply roller 550, a regulating blade 560 as an example of a charging member, and the like. .

  The developing roller 510 carries the toner T and conveys it to a developing position facing the photoconductor 20. The developing roller 510 is made of metal and is made of an aluminum alloy such as 5056 aluminum alloy or 6063 aluminum alloy, or an iron alloy such as STKM, and is subjected to nickel plating, chrome plating, or the like as necessary. Yes.

  Further, as shown in FIG. 3, the developing roller 510 is supported at both ends in the longitudinal direction, and is rotatable about the central axis. As shown in FIG. 4, the developing roller 510 rotates in a direction (counterclockwise in FIG. 4) opposite to the rotation direction of the photoconductor 20 (clockwise in FIG. 4). The central axis is below the central axis of the photoconductor 20.

  As shown in FIG. 4, there is a gap between the developing roller 510 and the photoconductor 20 in a state where the yellow developing device 54 faces the photoconductor 20. That is, the yellow developing device 54 develops the latent image formed on the photoconductor 20 in a non-contact state.

  Further, when developing the latent image formed on the photoreceptor 20, a developing bias generator 126 (see FIG. 2) provided in the developing device holding unit drive control circuit applies a DC voltage to the developing roller 510. A developing bias that is a voltage on which an alternating voltage is superimposed is applied, and an alternating electric field is formed between the developing roller 510 and the photoconductor 20. That is, in the present embodiment, the latent image carried on the photoconductor 20 is developed using a jumping development method. The developing device holding unit drive control circuit is provided with a developing bias control circuit 125 that plays a role of controlling on / off of the developing bias and setting an appropriate developing bias value.

  The seal member 520 prevents the toner T in the yellow developing device 54 from leaking out of the device, and collects the toner T on the developing roller 510 that has passed through the developing position into the developing device without being scraped off. The seal member 520 is a seal made of a polyethylene film or the like. The seal member 520 is supported by a seal support sheet metal 522 and is attached to the housing 540 via the seal support sheet metal 522. Further, a seal urging member 524 made of malt plain or the like is provided on the opposite side of the seal member 520 from the developing roller 510 side. The seal member 520 is developed by the elastic force of the seal urging member 524. 510 is pressed. Note that the contact position where the seal member 520 contacts the developing roller 510 is above the central axis of the developing roller 510.

  The housing 540 is manufactured by welding a plurality of integrally molded housing parts, that is, an upper housing part 542 and a lower housing part 544, and contains toner for containing toner T therein. A portion 530 is formed. The toner storage portion 530 is divided into two toner storage portions, that is, a first toner storage portion 530a and a second toner, by a partition wall 545 for partitioning the toner T that protrudes inwardly (in the vertical direction in FIG. 4) from the inner wall. It is divided into the accommodating portion 530b. The upper portions of the first toner storage portion 530a and the second toner storage portion 530b communicate with each other, and the movement of the toner T is restricted by the partition wall 545 in the state shown in FIG.

  However, when the developing device holding unit 50 rotates, the toner stored in the first toner storage portion 530a and the second toner storage portion 530b is temporarily moved to the upper communicating side of the developing position. When the toner is collected and returns to the state shown in FIG. 4, the toners are mixed and returned to the first toner storage portion 530a and the second toner storage portion 530b. That is, as the developing device holding unit 50 rotates, the toner T in the developing device is appropriately stirred.

  For this reason, in this embodiment, the stirring member is not provided in the toner storage portion 530, but a stirring member for stirring the toner T stored in the toner storage portion 530 may be provided. As shown in FIG. 4, the housing 540 (that is, the first toner storage portion 530 a) has an opening 572 in the lower portion, and the developing roller 510 is provided so as to face the opening 572.

  The toner supply roller 550 is provided in the first toner storage portion 530a described above, supplies the toner T stored in the first toner storage portion 530a to the development roller 510, and remains on the development roller 510 after development. The toner T is peeled off from the developing roller 510. The toner supply roller 550 is made of polyurethane foam or the like, and is in contact with the developing roller 510 in an elastically deformed state.

  The toner supply roller 550 is disposed below the first toner storage portion 530a, and the toner T stored in the first toner storage portion 530a is transferred by the toner supply roller 550 below the first toner storage portion 530a. Supplied to the developing roller 510. The toner supply roller 550 is rotatable about a central axis, and the central axis is below the rotation central axis of the developing roller 510. Further, the toner supply roller 550 rotates in a direction (clockwise in FIG. 4) opposite to the rotation direction of the developing roller 510 (counterclockwise in FIG. 4).

  The regulating blade 560 charges the toner T carried on the developing roller 510 by charging it, and regulates the layer thickness of the toner T carried on the developing roller 510. The restriction blade 560 is formed by a centrifugal molding method in which the material of the restriction blade 560 is poured into a hollow mold having an inner wall, and the restriction blade 560 is formed by rotating the mold. The details of the centrifugal molding method will be described later.

  The regulation blade 560 is obtained by dispersing a conductive agent in the polymer elastic body E which is a base material of the regulation blade 560, and has conductivity. Examples of the polymer elastic body E include various elastomers, polyurethane, silicon rubber, and other rubber materials. In this embodiment, carbon black CB (black dots in FIGS. 5A and 5B) is used as the conductive agent.

  The regulating blade 560 is in contact with the developing roller 510 and is positioned on the opposite side of the developing roller 510 from the first layer 561 including the carbon black CB and the carbon black CB. Two layers 562. The same polymer elastic body E is used for the base material of the first layer 561 and the base material of the second layer 562, respectively.

Here, the density of the carbon black CB contained in the second layer 562 is larger than the density of the carbon black CB contained in the first layer 561. As the density of the carbon black CB increases, the resistance values of the first layer 561 and the second layer 562 decrease. Therefore, in this embodiment, the resistance value of the first layer 561 is 1.0 × 10 ⁷ (Ω), for example, and the resistance value of the second layer 562 is 1.0 × 10 ⁵ (Ω), for example. .

  The first layer 561 includes an ionic conductive agent (not shown) in the polymer elastic body E in addition to the carbon black CB. On the other hand, the second layer 562 does not contain an ionic conductive agent. Here, examples of the ionic conductive agent include tetraethylammonium and tetrabutylammonium.

  The thickness of the first layer 561 is smaller than the thickness of the second layer 562. In the present embodiment, the thickness of the first layer 561 is 0.5 (mm), and the thickness of the second layer 562 is 1.5 ( mm).

  The regulating blade 560 (second layer air surface 562b (described later)) is supported by a metal blade supporting thin plate 565. The blade support thin plate 565 is a thin plate having a spring property such as phosphor bronze or stainless steel. The blade support thin plate 565 is attached to the housing 540 via the support metal plate 568 with one end thereof supported by the support metal plate 568. Further, a blade back member 570 made of malt plane or the like is provided on the side opposite to the developing roller 510 side of the regulating blade 560.

  Here, the regulating blade 560 is pressed against the developing roller 510 by the elastic force caused by the bending of the blade supporting thin plate 565. Further, the blade back member 570 prevents the toner T from entering between the blade support thin plate 565 and the housing 540, stabilizes the elastic force due to the bending of the blade support thin plate 565, and restricts from the back of the restriction blade 560. The regulating blade 560 is pressed against the developing roller 510 by urging the blade 560 toward the developing roller 510. Therefore, the blade back member 570 improves the uniform contact property of the regulating blade 560 to the developing roller 510.

  The end of the regulating blade 560 (first layer 561) opposite to the side supported by the support metal plate 568, that is, the tip is not in contact with the developing roller 510 and is separated from the tip by a predetermined distance. The portion is in contact with the developing roller 510 with a width. That is, the regulating blade 560 (first layer 561) is not in contact with the developing roller 510 at the edge, but is in contact with the belly. The regulating blade 560 is disposed so that the tip thereof faces the upstream side in the rotation direction of the developing roller 510, and is in a so-called counter contact. The contact position where the regulating blade 560 (first layer 561) contacts the developing roller 510 is below the central axis of the developing roller 510 and below the central axis of the toner supply roller 550.

  Further, a voltage is applied to the regulating blade 560 from the developing bias generator 126 (see FIG. 2) via the blade support thin plate 565 so that the potential thereof is the same as the potential of the developing roller 510.

  In the yellow developing device 54 configured as described above, the toner supply roller 550 supplies the toner T accommodated in the toner accommodating portion 530 to the developing roller 510. The toner T supplied to the developing roller 510 reaches the abutting position of the regulating blade 560 as the developing roller 510 rotates, and when the toner T passes through the corresponding contacting position, an electric charge is applied and the layer thickness is regulated. Is done. The charged toner T on the developing roller 510 reaches a developing position facing the photoconductor 20 by further rotation of the developing roller 510, and a latent image formed on the photoconductor 20 under an alternating electric field at the developing position. For development. The toner T on the developing roller 510 that has passed the developing position by further rotation of the developing roller 510 passes through the seal member 520 and is collected in the developing device without being scraped off by the seal member 520. Further, the toner T still remaining on the developing roller 510 can be peeled off by the toner supply roller 550.

=== Manufacturing Example of Regulating Blade 560 ===
As described above, the regulation blade 560 is a centrifugal molding method in which the material (base material, conductive agent, etc.) of the regulation blade 560 is poured into a hollow mold having an inner wall, and the regulation blade 560 is molded by rotating the mold. , Is formed by. Here, since the regulating blade 560 has the first layer 561 and the second layer 562, when the regulating blade 560 is formed by centrifugal molding, the material of the first layer 561 is poured into the mold. The mold is rotated, and then the material of the second layer 562 is poured into the mold to rotate the mold. Hereinafter, a manufacturing example of the regulating blade 560 by the centrifugal molding method will be described.

  First, a centrifugal molding machine used in the centrifugal molding method will be described with reference to FIG. FIG. 6 is a view showing an example of a centrifugal molding machine that is a manufacturing apparatus of the regulating blade 560. As shown in FIG. 6, the centrifugal molding machine has a cylindrical mold 923 in which a central portion of the bottom is fixed to one end of a rotating shaft 922 that is rotationally driven by a motor 921. The surface of the inner wall 923a of the cylindrical mold 923 is a mirror surface by polishing or the like. The cylindrical mold 923 is held in a box-shaped heating jacket 924, and the opening of the heating jacket 924 is closed with a lid 925. A heating passage 926 for flowing a heating fluid is provided on the outer periphery of the heating jacket 924, and the outside is covered with a heat insulating layer 927. The cylindrical mold 923 is an example of a “hollow mold”.

  Next, an example of manufacturing the regulating blade 560 using the centrifugal molding machine will be described with reference to FIGS. 7A and 7B. FIG. 7A is a schematic view showing a state in which the first layer 561 is formed. FIG. 7B is a schematic view showing a state in which the first layer 561 and the second layer 562 are molded. 7A and 7B are also enlarged views of part B in FIG.

  First, as shown in FIG. 7A, the first layer 561 is formed. Specifically, the material of the first layer 561 (a material in which a polymer elastic body, carbon black CB, and an ionic conductive agent are mixed) is poured into the cylindrical mold 923, and the cylindrical mold 923 is rotated. Then, after the material of the first layer 561 has spread to the surface of the inner wall 923a, the material is cured. Thus, a cylindrical first layer 561 is formed along the surface of the inner wall 923a.

  Note that the following phenomenon occurs when the first layer 561 is formed. That is, the carbon black CB moves to the surface side of the inner wall 923 a of the cylindrical mold 923 by the centrifugal force generated by the rotation of the cylindrical mold 923. Therefore, the distribution density of the carbon black CB increases as it goes to the die facing surface 561a facing the surface of the inner wall 923a of the cylindrical die 923, and the first layer air surface 561b on the side opposite to the die facing surface 561a The distribution density is sufficiently small or almost no carbon black CB exists. In the following, for convenience of explanation, the portion where the distribution density of the carbon black CB is large on the die facing surface 561a side is the dense portion I, and the distribution density of the carbon black CB is small or carbon black on the first layer air surface 561b side. A portion where CB hardly exists is referred to as non-dense portion II.

  On the other hand, the ionic conductive agent is relatively uniformly dispersed as compared with the carbon black CB, and is also present in the non-dense portion II. Further, as described above, since the surface of the inner wall 923a is a mirror surface, the mold facing surface 561a is in a smooth state.

  Next, after the first layer 561 is cured, a second layer 562 is formed inside the first layer 561 as shown in FIG. 7B. Specifically, the material of the second layer 562 (a material obtained by mixing a polymer elastic body and carbon black CB) is poured into the cylindrical mold 923, and the cylindrical mold 923 is rotated. Then, after the material of the second layer 562 spreads to the first layer air surface 561b, the material is cured. Thus, the first layer 561 and the second layer 562 are formed along the surface of the inner wall 923a. Here, a predetermined amount of carbon black is poured into the cylindrical mold 923 so that the density of the carbon black contained in the second layer 562 is larger than the density of the carbon black contained in the first layer 561.

  Note that the following phenomenon occurs when the second layer 562 is formed. That is, the carbon black CB moves to the first layer air surface 561b side by the centrifugal force generated by the rotation of the cylindrical mold 923. For this reason, the distribution density of the carbon black CB increases toward the contact surface 562a side that contacts the first layer air surface 561b, and the distribution density is sufficient on the second layer air surface 562b side opposite to the contact surface 562a. Or carbon black CB is almost absent. In the following, for convenience of explanation, as in the case of the first layer 561, the portion where the distribution density of the carbon black CB is large on the contact surface 562a side is the dense portion I, and the carbon black CB on the second layer air surface 562b side. A portion having a small distribution density of carbon black or having almost no carbon black CB is referred to as a non-dense portion II.

  Next, after the rotation of the cylindrical mold 923 is stopped, the cylindrical first layer 561 and the second layer 562 are taken out and cut into a sheet shape. Then, the regulation blade 560 can be obtained by cutting the sheet-like first layer 561 and the second layer 562 into a desired size. Note that the thickness of the first layer 561 and the second layer 562 can be controlled by the amount of the material poured into the cylindrical mold 923.

  Here, the dense part I and the non-dense part II described above will be described. In the first layer 561 and the second layer 562, the thickness of the non-dense portion II is sufficiently smaller than the thickness of the dense portion I. For example, the thickness of the non-dense portion II of the first layer 561 is about 100 (μm). . Further, the thickness of the non-dense portion II of the first layer 561 is smaller than the thickness of the non-dense portion II of the second layer 562. Further, at the boundary between the dense part I and the non-dense part II (the wavy line in FIG. 5A and the like indicates the boundary), the carbon black CB is dispersed unevenly (see FIG. 5B).

  In the present embodiment, the mold facing surface 561 a of the dense portion I of the first layer 561 comes into contact with the developing roller 510.

=== Function of Restricting Blade 560 Having First Layer 561 and Second Layer 562 ===
As described above, the regulating blade 560 is in contact with the developing roller 510, and is positioned on the opposite side of the first roller 561 containing the conductive agent (for example, carbon black CB) and the developing roller 510 when viewed from the first layer 561. And a second layer 562 containing a conductive agent whose density is higher than that of the conductive agent contained in the first layer 561. As a result, the occurrence of fogging can be suppressed. This will be described in detail below.

  The regulation blade 560 includes a conductive agent in order to have conductivity. In order to charge the toner T carried on the developing roller 510 to a desired charge amount, it is necessary that a sufficient amount of conductive agent is dispersed in the regulation blade 560 as a whole.

  On the other hand, paying attention to the contact portion of the regulating blade 560 with the developing roller 510, as the use of the developing devices 51, 52, 53, and 54 proceeds, the developing blade 510 contacts with the developing roller 510 due to friction caused by the rotation of the developing roller 510. The exposed surface is scraped off and the conductive agent is exposed. In such a case, when the toner T comes into contact with the exposed conductive agent, a decrease in the charge amount of the toner T is promoted. When the charge amount of the toner T carried on the developing roller 510 is too low, the toner T having a small charge amount that is not originally carried on the photoconductor 20 is not carried on the photoconductor 20, and as a result, the fogging May occur. Furthermore, when fog occurs, the quality of the image is degraded.

  As shown in FIG. 5A, the regulating blade 560 according to the present embodiment is positioned on the opposite side of the first layer 561 that is in contact with the developing roller 510 and the developing roller 510 when viewed from the first layer 561. A second layer 562. The density of the conductive agent included in the first layer 561 is smaller than the density of the conductive agent included in the second layer 562.

  In such a case, since the density of the conductive agent contained in the first layer 561 in contact with the developing roller 510 is reduced by dividing into two layers of the first layer 561 and the second layer 562, the developing roller 510 Even if the surface of the first layer 561 in contact with the surface is scraped, the possibility that the conductive agent is exposed decreases. Therefore, in this embodiment, it is possible to suppress a decrease in the charge amount of the toner T due to the exposure of the conductive agent. On the other hand, since only the density of the conductive agent contained in the first layer 561 is reduced, it is possible to ensure a sufficient amount of conductive agent as a whole.

  As a result, when the regulating blade 560 includes the first layer 561 and the second layer 562 described above, the toner T carried on the developing roller 510 is appropriately obtained while securing a sufficient amount of conductive agent as a whole. Therefore, it is possible to prevent the toner T having a small charge amount that is not originally carried on the photoconductor 20 from being carried on the photoconductor 20, and as a result, it is possible to suppress the occurrence of fogging. .

=== Other Embodiments ===
The image forming apparatus and the like according to the present invention have been described above based on the above embodiment. However, the above embodiment of the present invention is for facilitating understanding of the present invention and limits the present invention. is not. The present invention can be changed and improved without departing from the gist thereof, and the present invention includes the equivalents thereof.

  The present invention includes a developing roller 510 (developer carrying member) for carrying toner T (developer), a first layer 561 that contacts the developing roller 510 and contains a conductive agent, and the first layer 561. And a second layer 562 containing a conductive agent whose density is higher than that of the conductive agent contained in the first layer 561, which is located on the opposite side of the developing roller 510, and is carried by the developing roller 510. In addition, the present invention relates to developing devices 51, 52, 53, and 54 (developing devices) each having a regulating blade 560 (charging member) for charging the toner T.

  In the above embodiment, the intermediate transfer type full color laser beam printer has been described as an example of the image forming apparatus. However, the present invention is not limited to the intermediate transfer type, but a full color laser beam printer, a monochrome laser beam printer, a copying machine, a facsimile machine. The present invention can be applied to various image forming apparatuses.

  In the above-described embodiment, the image forming apparatus including the rotary type developing device has been described as an example. However, the present invention is not limited to this. For example, the present invention can be applied to an image forming apparatus provided with a tandem developing device.

  In the above embodiment, the photoconductor as the image carrier has been described as a configuration in which the photosensitive layer is provided on the outer peripheral surface of the cylindrical conductive base material, but the present invention is not limited to this. For example, a so-called photosensitive belt configured by providing a photosensitive layer on the surface of a belt-like conductive substrate may be used.

  In the above-described embodiment, the developer carrying member is the metal developing roller 510. However, the present invention is not limited to this. For example, the developer carrying member may be a developing belt made of a resin belt-like base material.

Further, in the above embodiment, as shown in FIG. 6, the regulating blade 560 flows the material (base material) of the regulating blade 560 into a cylindrical mold 923 (hollow mold) having an inner wall 923a. However, the present invention is not limited to this, but is formed by a centrifugal molding method in which the regulating blade 560 is molded by rotating 923. For example, the regulation blade 560 may be molded by a method other than the centrifugal molding method.
However, when the regulation blade 560 is formed by the centrifugal molding method, the regulation blade 560 can be easily obtained. Therefore, the above embodiment is more desirable.

  In the above embodiment, the polymer elastic body is used as the base material of the regulating blade 560. However, a flexible material may be used. Examples of the flexible material include polyamide, polyethylene terephthalate, and other organic materials.

  Further, in the above embodiment, as shown in FIGS. 7A and 7B, when the regulating blade 560 is formed by centrifugal molding, the material of the first layer 561 (polymer elastic body, carbon black, ionic conductive agent) Material) is poured into a cylindrical mold 923 and the cylindrical mold 923 is rotated (that is, the first layer 561 is formed), and then the material of the second layer 562 (polymer elastic body and carbon black is mixed). The material) was poured into the cylindrical mold 923 and the cylindrical mold 923 was rotated (that is, the second layer 562 was formed). In this case, the mold facing surface 561a of the first layer 561 comes into contact with the developing roller 510 as shown in FIG. 5A. Hereinafter, the restriction blade 560 formed in this way is also referred to as a restriction blade 560 of the first embodiment.

  However, it is not limited to the above. For example, as shown in FIG. 8, when the regulating blade 560 is formed by centrifugal molding, the material of the second layer 562 is poured into the cylindrical mold 923 to rotate the cylindrical mold 923, and then the first layer 561 The material may be poured into the cylindrical mold 923 and the cylindrical mold 923 may be rotated. In this case, as shown in FIG. 9, the first layer air surface 561 b on the non-crowded part II side of the first layer 561 comes into contact with the developing roller 510. FIG. 8 is a view showing a state where the regulating blade 560 of the second embodiment is molded. FIG. 9 is a view showing a state in which the regulating blade 560 of the second embodiment shown in FIG.

  However, when the conductive agent is dispersed non-uniformly, the resistance value of the regulating blade 560 becomes non-uniform. When the conductive agent is non-uniformly distributed on the surface that contacts the developing roller 510, the resistance value varies in the vicinity of the surface, so that the charge amount of the toner T tends to be non-uniform. In such a case, streaks (streaks along the rotation direction of the photoconductor 20) may occur in the toner image formed on the photoconductor 20 using the toner T having a non-uniform charge amount. Incidentally, the conductive agent is uniformly dispersed in the vicinity of the mold facing surface 561a. Therefore, when the regulation blade 560 of the first embodiment in which the mold facing surface 561a is in contact with the developing roller 510 is used, it is possible to appropriately charge the toner T carried on the developing roller 510 and to generate streaks. Can be suppressed. Therefore, the above embodiment is more desirable.

  Further, as shown in FIG. 10, the first layer 561 and the second layer 562 may be separately molded by centrifugal molding, and the first layer 561 and the second layer 562 may be bonded. FIG. 10 is a view showing the regulating blade 560 of the third embodiment.

  Further, when manufacturing the developing devices 51, 52, 53, and 54, the process shown in FIG. 11, that is, the material of the first layer 561 is poured into the cylindrical mold 923, and then the cylindrical mold 923 is rotated. The material of the layer 562 is poured into the cylindrical mold 923, the cylindrical mold 923 is rotated, the regulating blade 560 is formed by the centrifugal molding method (step s202), and the first of the regulating blade 560 molded by the centrifugal molding method. When the layer 561 is brought into contact with the developing roller 510 and the second layer 562 is positioned on the side opposite to the developing roller 510 when viewed from the first layer 561 (step s204), the occurrence of fogging is suppressed and the streak of Occurrence can be suppressed. FIG. 11 is a flowchart for explaining a method of manufacturing the developing devices 51, 52, 53, and 54.

Furthermore, in the said embodiment, as shown to FIG. 5A, although the electrically conductive agent was carbon black CB, it is not limited to this. For example, the conductive agent may have conductivity such as metal powder or metal oxide.
However, the carbon black CB has a high cost merit, and furthermore, the conductivity can be appropriately maintained even if the environment changes. Therefore, the above embodiment is more desirable.

Furthermore, in the said embodiment, although the 1st layer 561 included the ionic conductive agent, it is not limited to this. For example, the first layer 561 may not include an ionic conductive agent.
However, when the first layer 561 includes an ionic conductive agent in addition to the carbon black CB, the amount of the carbon black CB can be reduced compared to the case where the first layer 561 does not include the ionic conductive agent. The amount of CB is reduced, and a decrease in the charge amount of the toner T carried on the developing roller 510 can be effectively prevented. Therefore, when the first layer 561 contains an ionic conductive agent, it is possible to effectively suppress the occurrence of fog. Therefore, the above embodiment is more desirable.

  In the above embodiment, the second layer 562 does not include an ionic conductive agent, but the second layer 562 may include an ionic conductive agent.

  The first layer 561 may include materials other than the base material, the conductive agent, and the ionic conductive agent, and the second layer 562 may include materials other than the base material and the conductive agent. Good. Further, the base material of the first layer 561 and the base material of the second layer 562 may be different.

=== Configuration of Image Forming System etc. ===
Next, an image forming system according to an embodiment of the present invention will be described with reference to the drawings.

  FIG. 12 is an explanatory diagram showing an external configuration of the image forming system. The image forming system 700 includes a computer 702, a display device 704, a printer 10, an input device 708, and a reading device 710.

  In this embodiment, the computer 702 is housed in a mini-tower type housing, but is not limited thereto. The display device 704 is generally a CRT (Cathode Ray Tube), a plasma display, a liquid crystal display device, or the like, but is not limited thereto. As the printer 10, the printer described above is used. In this embodiment, the input device 708 uses a keyboard 708A and a mouse 708B, but is not limited thereto. In this embodiment, the reading device 710 uses a flexible disk drive device 710A and a CD-ROM drive device 710B. However, the reading device 710 is not limited to this. For example, an MO (Magneto Optical) disk drive device or a DVD (Digital Versatile) is used. Disk) etc. may be used.

  FIG. 13 is a block diagram showing a configuration of the image forming system shown in FIG. An internal memory 802 such as a RAM and an external memory such as a hard disk drive unit 804 are further provided in a housing in which the computer 702 is housed.

  In the above description, an example in which the printer 10 is connected to the computer 702, the display device 704, the input device 708, and the reading device 710 to configure the image forming system has been described. However, the present invention is not limited to this. Absent. For example, the image forming system may include the computer 702 and the printer 10, and the image forming system may not include any of the display device 704, the input device 708, and the reading device 710.

  For example, the printer 10 may have a part of each function or mechanism of the computer 702, the display device 704, the input device 708, and the reading device 710. As an example, the printer 10 includes an image processing unit that performs image processing, a display unit that performs various displays, a recording medium attachment / detachment unit for attaching / detaching a recording medium that records image data captured by a digital camera or the like. It is good also as a structure to have.

  The image forming system realized in this way is a system superior to the conventional system as a whole system.

FIG. 2 is a diagram illustrating main components of a printer. 2 is a block diagram showing a control unit 100. FIG. It is a conceptual diagram of a developing device. It is sectional drawing which showed the main components of the developing device. FIG. 5A is a schematic view showing the periphery of the regulating blade 560. FIG. 5B is a schematic diagram illustrating a boundary portion (corresponding to a portion A in FIG. 5A) between the first layer 561 and the second layer 562. It is the figure which showed an example of the centrifugal molding machine which is a manufacturing apparatus of the control blade 560. FIG. FIG. 7A is a schematic view showing a state where the first layer is formed. FIG. 7B is a schematic view showing a state in which the first layer and the second layer are formed. It is the figure which showed the state by which the control blade 560 of the 2nd Example was shape | molded. FIG. 9 is a diagram showing a state in which the regulating blade 560 of the second embodiment shown in FIG. It is the figure which showed the control blade 560 of 3rd Example. 3 is a flowchart for explaining a method for manufacturing developing devices 51, 52, 53, and 54. 1 is an explanatory diagram showing an external configuration of an image forming system. It is a block diagram which shows the structure of the image forming system shown in FIG.

Explanation of symbols

10 printer, 20 photoconductor, 30 charging unit, 40 exposure unit,
50 Developer holding unit,
50a, 50b, 50c, 50d Detachable part, 50e Rotating shaft,
51 Black developer, 52 Cyan developer, 53 Magenta developer,
54 yellow developing device, 60 primary transfer unit, 70 intermediate transfer member,
75 cleaning unit, 76 cleaning blade,
80 secondary transfer unit, 90 fixing unit, 92 paper feed tray,
94 paper feed roller, 95 display unit, 96 registration roller,
100 control unit, 101 controller unit, 102 unit control unit,
112 interface, 113 image memory, 125 development bias control circuit,
126 bias generator,
510 developing roller, 520 seal member, 522 seal support sheet metal,
524 seal urging member, 530 toner accommodating portion, 530a first toner accommodating portion,
530b second toner storage portion, 540 housing, 542 upper housing portion,
544 lower housing portion, 550 toner supply roller, 560 regulating blade,
561 1st layer, 561a type facing surface, 561b 1st layer air surface,
562 second layer, 562a contact surface, 562b second layer air surface,
565 blade support sheet, 568 support sheet metal,
570 Blade backing member, 572 opening,
700 image forming system, 702 computer, 704 display device,
708 input device, 708A keyboard, 708B mouse, 710 reader,
710A flexible disk drive device, 710B CD-ROM drive device,
802 internal memory, 804 hard disk drive unit,
921 motor, 922 rotation shaft, 923 cylindrical type, 923a inner wall,
924 heating jacket, 925 lid, 926 heating passage, 927 thermal insulation layer,
CB carbon black, I dense part, II non-dense part, T toner

Claims (10)

A developer carrier for carrying the developer;
The first layer in contact with the developer carrying member and containing the conductive agent, and located on the opposite side of the developer carrying member as viewed from the first layer, the density thereof is contained in the first layer. A second layer containing a conductive agent greater than the density of the conductive agent, and a charging member for charging the developer carried on the developer carrying member,
A developing device comprising: The developing device according to claim 1,
The charging member is
A centrifugal molding method in which the material of the charging member is poured into a hollow mold having an inner wall, and the charging member is molded by rotating the mold;
A developing device formed by the method described above. The developing device according to claim 2,
When forming the charging member by the centrifugal molding method, the material of the first layer is poured into the mold, the mold is rotated, and then the material of the second layer is poured into the mold. A developing device that is rotated. The developing device according to any one of claims 1 to 3,
The developing device, wherein the conductive agent is carbon black. The developing device according to any one of claims 1 to 4,
The developing device, wherein the first layer contains an ionic conductive agent. A developer carrier for carrying the developer;
The first layer in contact with the developer carrying member and containing the conductive agent, and located on the opposite side of the developer carrying member as viewed from the first layer, the density thereof is contained in the first layer. A second layer containing a conductive agent greater than the density of the conductive agent, and a charging member for charging the developer carried on the developer carrying member,
Have
The charging member is
A centrifugal molding method in which the material of the charging member is poured into a hollow mold having an inner wall, and the charging member is molded by rotating the mold;
Molded by
When forming the charging member by the centrifugal molding method, the material of the first layer is poured into the mold, the mold is rotated, and then the material of the second layer is poured into the mold. Rotate,
The conductive agent is carbon black,
The developing device, wherein the first layer contains an ionic conductive agent. An image carrier for carrying a latent image, and
A developing device for developing a latent image carried on the image carrier,
A developer carrier for carrying the developer;
The first layer in contact with the developer carrying member and containing the conductive agent, and located on the opposite side of the developer carrying member as viewed from the first layer, the density thereof is contained in the first layer. A second layer containing a conductive agent greater than the density of the conductive agent, and a charging member for charging the developer carried on the developer carrying member,
A developing device having
An image forming apparatus comprising: Computer, and
An image forming apparatus connectable to the computer,
An image carrier for carrying a latent image, and a developing device for developing the latent image carried on the image carrier, the developer carrier for carrying the developer, and the developer A first layer containing a conductive agent in contact with the carrier, and located on the opposite side of the developer carrier as viewed from the first layer, the density of the conductive agent contained in the first layer; An image forming apparatus comprising: a developing device comprising: a second layer including a conductive agent having a density greater than that of the density; and a charging member for charging the developer carried on the developer carrying member.
An image forming system comprising: A charging member for charging the developer carried on the developer carrying member,
A first layer in contact with the developer carrier and containing a conductive agent;
A second layer comprising a conductive agent located on the opposite side of the developer carrier as viewed from the first layer, the density of which is greater than the density of the conductive agent contained in the first layer;
A charging member comprising: A developer carrier for carrying the developer, and
A first layer containing a conductive agent and a second layer having a density higher than that of the conductive agent contained in the first layer, the development carried on the developer carrier. A charging member for charging the agent;
A method for producing a developing device comprising:
The material of the first layer is poured into a hollow mold having an inner wall and the mold is rotated, and then the material of the second layer is poured into the mold and the mold is rotated, and the charging member is obtained by centrifugal molding. Molding the step;
The first layer of the charging member formed by the centrifugal molding method is brought into contact with the developer carrier, and the developer carrier is viewed from the first layer when the second layer of the charging member is viewed from the first layer. A step located on the opposite side of
A method for producing a developing device, comprising:

Images