JP4784273B2 - Developer carrying roller, developing device, image forming apparatus, and image forming system - Google Patents

Description

  The present invention relates to a developer carrying roller, a developing device, an image forming apparatus, and an image forming system.

  Image forming apparatuses such as laser beam printers are already well known. Such an image forming apparatus includes, for example, a photoconductor for carrying a latent image and a developing device for developing the latent image carried on the photoconductor by a developer, and from an external device such as a host computer. When an image signal or the like is transmitted, the developing device is positioned at a developing position facing the photosensitive member, and the latent image carried on the photosensitive member is developed with the developer in the developing device to form a developer image. The developer image is transferred to a medium, and finally an image is formed on the medium.

The developing device includes a developer carrying roller for carrying the developer in order to realize the above-described function of developing the latent image carried on the photoreceptor, and the developer carrying roller. Some of them have a plurality of convex portions regularly arranged and provided with a top surface on the surface.
JP-A-5-142950 JP-A-1-102486

By the way, when designing the shape or the like of the convex portion described above, a sufficient amount of developer is carried on the surface of the developer carrying roller, in other words, the surface area of the surface on which the developer is carried is reduced. It should be noted that the value is sufficiently large. For this purpose, it is necessary to increase the height of the top surface provided on the convex portion from the non-convex portion to some extent.
However, when the height is increased, the side portion of the convex portion that extends from the top surface to the non-convex portion becomes a wall, and the developer located on the non-convex portion is difficult to move to the top surface. Therefore, the problem of deterioration of the rolling property of the toner may occur.

  The present invention has been made in view of such problems, and an object thereof is to improve the rolling property of the developer.

A main aspect of the present invention is a developer carrying roller for carrying a developer having a plurality of regularly arranged convex portions on the surface, wherein the convex portions are formed in a mesh shape. surrounded by, a stepped sides from the top surface of the convex portion continuing to the non-convex portion, located between the top surface and the non-protruding portion in the radial direction of the developer bearing roller A developer carrying roller comprising a side portion having a flat step surface.

  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-carrying roller for carrying a developer having a plurality of regularly arranged convex portions on the surface, wherein the convex portions are stepped from the top surface of the convex portion to a non-convex portion. And a side portion provided with a flat step surface located between the top surface and the non-convex portion in the radial direction of the developer carrying roller. Supporting roller.
According to such a developer carrying roller, the rolling property of the developer is improved.

Further, the developer may be granular, and the width of the step surface in the depth direction may be greater than or equal to the volume average particle diameter of the developer.
In such a case, the stepped surface can sufficiently serve as an intermediate landing when the developer moves from the non-convex portion to the top surface, and the rolling property of the developer is further improved.

The developer has a granular shape, and the side portion is provided with a plurality of steps, and the height of at least one of the steps is a volume average particle diameter of the developer. It may be the following.
In such a case, the developer located on the non-convex portion is more smoothly moved to the top surface via the step surface, and the rolling property of the developer is further improved.

The top surface may be a quadrangle, and the convex portion may have four side portions corresponding to the sides of the quadrangle.
The normal direction of the step surface may be along the normal direction of the top surface.
In such a case, the stepped surface can sufficiently serve as an intermediate landing when the developer moves from the non-convex portion to the top surface, and the rolling property of the developer is further improved.

Further, the developer may be granular, and the height of the top surface from the non-convex portion may be not more than twice the volume average particle diameter of the developer.
In such a case, the chargeability of the developer can be improved.

  Further, the top surface, the stepped surface, and the non-convex portion may be a developer carrying portion for carrying a developer.

A developer carrying roller for carrying a developer having a plurality of regularly arranged convex portions on the surface, wherein the convex portions are continuous from the top surface of the convex portion to a non-convex portion. A side portion having a stepped side portion and a flat step surface located between the top surface and the non-convex portion in the radial direction of the developer carrying roller, and the developer Has a granular shape, the width in the depth direction of the step surface is equal to or greater than the volume average particle size of the developer, the side portion is provided with a plurality of steps, at least of the plurality of steps The height of one step is not more than the volume average particle diameter of the developer, the top surface is a quadrangle, and the convex part has four side parts corresponding to the sides of the quadrangle. The normal direction of the step surface is along the normal direction of the top surface, and the height of the top surface from the non-convex portion is the height of the developer. It is also possible to realize a developer carrying roller that is not more than twice the product average particle diameter, and that the top surface, the stepped surface, and the non-convex portion are developer carrying portions for carrying the developer. It is.
In this way, the effects of the present invention can be achieved more effectively because all the effects described above can be achieved.

A developer carrying roller for carrying a developer having a plurality of regularly arranged convex portions on the surface, wherein the convex portions are continuous from the top surface of the convex portion to a non-convex portion. A developer-carrying roller having a stepped side part and a side part provided with a flat stepped surface located between the top surface and the non-convex part in the radial direction of the developer-carrying roller; It is also possible to realize a developing device characterized by comprising
According to such a developing device, the rolling property of the developer is improved.

  A layer thickness regulating member for regulating a layer thickness of the developer carried on the developer carrying roller, wherein a plane of the layer thickness regulating member comes into contact with the developer carrying roller, and the layer It is good also as having the layer thickness control member which controls thickness.

A developer carrying roller for carrying a developer having a plurality of regularly arranged convex portions on the surface, wherein the convex portions are continuous from the top surface of the convex portion to a non-convex portion. A developer-carrying roller having a stepped side part and a side part provided with a flat stepped surface located between the top surface and the non-convex part in the radial direction of the developer-carrying roller; It is also possible to realize an image forming apparatus having a developing device including
According to such an image forming apparatus, the rolling property of the developer is improved.

A computer and an image forming apparatus connectable to the computer, the developer carrying roller having a plurality of regularly arranged convex portions on the surface and carrying the developer; The convex portion is a stepped side portion that continues from the top surface of the convex portion to the non-convex portion, and is flat between the top surface and the non-convex portion in the radial direction of the developer carrying roller. An image forming system including an image forming apparatus having a developing device having a developer carrying roller having a side portion provided with a stepped surface can also be realized.
According to such an image forming system, the rolling property of the developer is improved.

=== Example of Overall Configuration 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 YMCK developing unit 50, a primary transfer unit 60, an intermediate transfer body 70, along the rotation direction of the photoreceptor 20. A cleaning unit 75, and further, a secondary transfer unit 80, a fixing unit 90, a display unit 95 configured as a liquid crystal panel as a means for notifying a user, and a control for controlling these units and the like and controlling the operation as a printer. A unit 100 is included.

  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 YMCK developing unit 50 converts the latent image formed on the photoconductor 20 into toner T as an example of a developer accommodated in the developing device, that is, black (K) toner, magenta accommodated in the black developing device 51. An apparatus for developing using magenta (M) toner contained in the developing device 52, cyan (C) toner contained in the cyan developing device 53, and yellow (Y) toner contained in the yellow developing device 54 It is.

  The YMCK developing unit 50 can move the positions of the four developing devices 51, 52, 53, 54 by rotating with the four developing devices 51, 52, 53, 54 mounted. Yes. That is, the YMCK developing unit 50 holds the four developing devices 51, 52, 53, 54 by four holding portions 55a, 55b, 55c, 55d, and the four developing devices 51, 52, 53, 54 is rotatable around the central axis 50a while maintaining the relative position thereof. 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 contained in each developing device 51, 52, 53, 54. The latent images are sequentially developed. Each of the four developing devices 51, 52, 53, 54 described above is detachable from the holding portion of the YMCK developing unit 50. Details of each developing device 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.
This intermediate transfer body 70 is an endless belt in which a tin 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 main controller 101 and a unit controller 102. An image signal and a control signal are input to the main controller 101, and in response to a command based on the image signal and the control signal. A unit controller 102 controls each of the units and forms 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 main controller 101 of the printer 10 via the interface (I / F) 112, the unit controller 102 based on a command from the main controller 101. The photosensitive member 20 and the intermediate transfer member 70 are rotated by the 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. . In the YMCK developing unit 50, a yellow developing device 54 that contains yellow (Y) toner is located at a 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 main controller 101 of the control unit 100 is electrically 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 is electrically connected to each unit (charging unit 30, exposure unit 40, YMCK developing unit 50, primary transfer unit 60, cleaning unit 75, secondary transfer unit 80, fixing unit 90, display unit 95) of the apparatus main body. Each unit is controlled based on a signal input from the main controller 101 while detecting a state of each unit by receiving a signal from a sensor included in the unit.

=== Configuration Example of Developing Device ===
Next, a configuration example of the developing device will be described with reference to FIGS. FIG. 3 is a conceptual diagram of the developing device. FIG. 4 is a cross-sectional view showing main components of the developing device. FIG. 5 is a schematic perspective view of the developing roller 510. FIG. 6 is a schematic front view of the developing roller 510. FIG. 7 is a schematic diagram showing the shape of the convex portion 512. FIG. 8 is a perspective view of the regulating blade 560. FIG. 9 is a perspective view of the holder 526. FIG. 10 is a perspective view showing a state in which the upper seal 520, the regulating blade 560, and the developing roller 510 are assembled to the holder 526. FIG. 11 is a perspective view showing a state in which the holder 526 is attached to the housing 540. 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. Further, in FIG. 4, the yellow developing device 54 is shown in a state where the yellow developing device 54 is located at a developing position facing the photoconductor 20. Further, in FIGS. 5 to 7, the scales of the convex portions 512 and the like are different from the actual ones for easy understanding of the drawings.

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

The yellow developing device 54 includes a developing roller 510 as an example of a developer carrying roller, an upper seal 520, a toner container 530, a housing 540, a toner supply roller 550, a regulating blade 560 as an example of a layer thickness regulating member, a holder 526, and the like. have.
The developing roller 510 carries the toner T and conveys it to a developing position facing the photoconductor 20. The developing roller 510 is a member made of an aluminum alloy, an iron alloy, or the like.
As shown in FIGS. 6 and 7, the developing roller 510 has a convex portion 512 on the surface of its central portion 510a in order to properly carry the toner T. The convex portion 512 includes a top surface 513 and a side portion 514.

  The top surface 513 is the highest portion of the convex portions 512 and has a square (quadrangle) planar shape as shown in the upper diagram of FIG. The length L1 of one side of the square top surface 513 (see the lower diagram in FIG. 7) is about 12 μm. Further, the height H1 of the top surface 513 from the non-convex portion 515 (the length from the top surface 513 to the non-convex portion 515 in the radial direction of the developing roller 510, see the lower diagram in FIG. 7) is about 10 μm. . In the present embodiment, the toner T is granular (particulate), and the volume average particle size of the toner T is about 7 μm. Therefore, the height of the top surface 513 from the non-convex portion 515 is It is not less than the volume average particle size and not more than twice the volume average particle size.

  The side portion 514 is a stepped portion that continues from the top surface 513 to the non-convex portion 515, and the convex portion 512 corresponds to each side of the square top surface 513 described above, as shown in the upper diagram of FIG. 7. Thus, four side portions 514 are provided. The side portion 514 includes a step surface 514a, a first inclined surface 514b, and a second inclined surface 514c.

  The step surface 514a is a flat surface located between the top surface 513 and the non-convex portion 515 in the radial direction of the developing roller 510 (the top surface 513, the step surface 514a, and the non-convex portion 515 are Both of them function as a toner carrying portion for carrying toner). The normal direction A1 of the step surface 514a is along the normal directions A2 and A3 of the top surface 513 and the non-convex portion 515, as shown in the lower diagram of FIG. The width L2 in the depth direction of the step surface 514a (see the lower diagram in FIG. 7) is about 12 μm, which is equal to or larger than the volume average particle diameter of the toner T.

  Further, since the side portion 514 has the step surface 514a, a plurality of steps are generated in the side portion 514. In the present embodiment, there is one step surface 514a, and thus two steps are generated. The heights H2 and H3 of both steps (see the lower diagram in FIG. 7) are both about 5 μm, which is equal to or smaller than the volume average particle diameter of the toner T.

  In the present embodiment, the step surface 514a is located at the midpoint between the top surface 513 and the non-convex portion 515 in the radial direction of the developing roller 510, and the height of the step H2 and the height of the step H3 are the same. However, the present invention is not limited to this, and the step surface 514a is not positioned at the midpoint between the top surface 513 and the non-convex portion 515 in the radial direction of the developing roller 510, and the height of the step H2 and the step The height of H3 may be different. Further, the number of the step surfaces 514a is one, but it is not limited to this, and may be two or more (in this case, three or more steps are generated).

  The first inclined surface 514b is a surface that connects the step surface 514a and the non-convex portion 515, and the second inclined surface 514c is a surface that connects the step surface 514a and the top surface 513. The inclination angle of the first inclined surface 514b and the second inclined surface 514c is about 45 degrees as shown in the lower diagram of FIG.

  As shown in the upper diagrams of FIGS. 5, 6, and 7, the convex portion 512 configured in this way has many regular and mesh-like surfaces on the surface of the central portion 510 a of the developing roller 510. Has been placed. Therefore, the non-convex portion 515 is formed in a net shape so as to surround the four sides of the convex portion 512. Note that the pitch P of the convex portions 512 provided on the surface of the central portion 510a (see the lower diagram in FIG. 7) is about 68 μm. Further, electroless Ni—P plating is applied to the surface of the central portion 510a.

  Further, as shown in FIG. 6, the convex portion 512 is formed by the direction of one side of the top surface 513 (indicated by the symbol X and symbol Y in FIG. 6) and the axial direction of the developing roller 510. It is provided so that the acute angle is about 45 degrees. Therefore, the non-convex portion 515 is formed in a spiral shape with an inclination of about 45 degrees from the axial direction (FIG. 5). The non-convex portion 515 has a width L3 (see the lower diagram in FIG. 7) of about 12 μm.

  Further, the developing roller 510 is provided with a shaft portion 510b. The shaft portion 510b is supported by a developing roller support portion 526b of a holder 526, which will be described later, via a bearing 576 (FIG. 10). 510 is rotatably supported. 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.

  Further, a gap exists 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. When developing the latent image formed on the photoconductor 20, an alternating electric field is formed between the developing roller 510 and the photoconductor 20.

  The housing 540 is manufactured by welding a plurality of integrally formed resin housing parts, that is, the upper housing part 542 and the lower housing part 544, and in order to accommodate the toner T therein. The toner container 530 is formed. The toner containing body 530 has two toner containing portions, that is, a first toner containing portion 530a and a second toner, by a partition wall 545 for dividing the toner T projected 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 YMCK developing unit 50 rotates, the toner accommodated in the first toner accommodating portion 530a and the second toner accommodating portion 530b is once collected on the upper communicating side of the developing position. When returning 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, when the YMCK developing unit 50 rotates, the toner T in the developing device is appropriately agitated.

  For this reason, in this embodiment, the toner container 530 is not provided with a stirring member, but a stirring member for stirring the toner T stored in the toner container 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 upper seal 520 is in contact with the developing roller 510 along the axial direction thereof, allows the toner T remaining on the developing roller 510 after passing through the developing position to move into the housing 540, and the housing 540. The movement of the toner T inside the housing 540 is restricted. The upper seal 520 is a seal made of a polyethylene film or the like. The upper seal 520 is supported by an upper seal support portion 526a of a holder 526, which will be described later, and is provided such that its longitudinal direction is along the axial direction of the developing roller 510 (FIG. 10). The contact position where the upper seal 520 contacts the developing roller 510 is above the central axis of the developing roller 510.

  Further, a malt is provided between the surface of the upper seal 520 opposite to the contact surface 520b that contacts the developing roller 510 (this surface is also referred to as the opposite surface 520c) and the upper seal support portion 526a. An upper seal urging member 524 made of an elastic body such as a plane is provided in a compressed state. The upper seal urging member 524 presses the upper seal 520 against the developing roller 510 by urging the upper seal 520 toward the developing roller 510 with the urging force.

  The regulating blade 560 abuts against the developing roller 510 at the abutting portion 562a from one end to the other end in the axial direction of the developing roller 510 to regulate the layer thickness of the toner T carried on the developing roller 510, In addition, a charge is applied to the toner T carried on the developing roller 510. As shown in FIGS. 4 and 8, the regulation blade 560 includes a rubber part 562 and a rubber support part 564.

The rubber part 562 is made of silicon rubber, urethane rubber, or the like, and is in contact with the developing roller 510.
The rubber support portion 564 includes a thin plate 564a and a thin plate support portion 564b, and supports the rubber portion 562 at one end portion 564d in the short direction (that is, the end portion on the thin plate 564a side). The thin plate 564a is made of phosphor bronze, stainless steel or the like and has a spring property. The thin plate 564a supports the rubber part 562 and presses the rubber part 562 against the developing roller 510 by the biasing force. The thin plate support portion 564b is a metal sheet metal disposed on the other end 564e in the short side direction of the rubber support portion 564, and the thin plate support portion 564b is a side of the thin plate 564a that supports the rubber portion 562. It is attached to the said thin plate 564a in the state which supported the edge on the opposite side.

The regulating blade 560 is attached to the regulating blade support portion 526c in a state where both longitudinal end portions 564c of the thin plate supporting portion 564b are supported by the regulating blade support portion 526c of the holder 526 described later.
The end of the regulating blade 560 opposite to the thin plate support portion 564b side, that is, the tip 560a is not in contact with the developing roller 510, and is a portion separated from the tip 560a by a predetermined distance (that is, the contact portion 562a). ) Is in contact with the developing roller 510 with a width. In other words, the regulating blade 560 is not in contact with the developing roller 510 at the edge but is in contact with the antinode, and the flat surface of the regulating blade 560 comes into contact with the developing roller 510 to regulate the layer thickness. To do. Further, the regulating blade 560 is disposed so that its tip 560a faces the upstream side in the rotation direction of the developing roller 510, and is in contact with a so-called counter. The contact position where the regulating blade 560 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, the regulation blade 560 exhibits a function of preventing leakage of the toner T from the toner container 530 by contacting the developing roller 510 along the axial direction thereof.

  Further, as shown in FIG. 10, an end seal 574 is provided on the outer side in the longitudinal direction of the rubber portion 562 of the regulating blade 560. The end seal 574 is formed of a non-woven fabric, contacts the axial end of the developing roller 510 along the peripheral surface of the developing roller 510, and toner from between the peripheral surface and the housing 540. Demonstrates the function of preventing T leakage.

  The holder 526 is a metal member for assembling various members such as the developing roller 510, and as shown in FIG. 9, the upper seal support portion along the longitudinal direction (that is, the axial direction of the developing roller 510). 526a, a developing roller support portion 526b provided outside the upper seal support portion 526a in the longitudinal direction (the axial direction), intersecting the longitudinal direction (the axial direction), and intersecting the developing roller support portion, A regulating blade support portion 526c facing the longitudinal end of the upper seal support portion 526a.

  As shown in FIG. 10, the upper seal 520 is supported by the upper seal support portion 526a at the short-side end portion 520a (FIG. 4), and the developing roller 510 is at the end thereof. , And is supported by a developing roller support portion 526b.

  Further, the regulating blade 560 is supported by the regulating blade support portion 526c at both longitudinal end portions 564c thereof. The restriction blade 560 is fixed to the holder 526 by being screwed to the restriction blade support portion 526c.

  In this way, the holder 526 in which the upper seal 520, the developing roller 510, and the regulating blade 560 are assembled prevents the toner T from leaking between the holder 526 and the housing 540 as shown in FIG. It is attached to the housing 540 described above via a housing seal 546 (FIG. 4).

  In the yellow developing device 54 configured as described above, the toner supply roller 550 supplies the toner T stored in the toner container 530 to the developing roller 510. The toner T supplied to the developing roller 510 reaches the contact position of the regulating blade 560 as the developing roller 510 rotates, and the layer thickness is regulated and electric charge is applied when passing through the contact position. Is done. The toner T on the developing roller 510 to which the layer thickness is regulated and the electric charge is applied reaches the developing position facing the photosensitive member 20 by further rotation of the developing roller 510, and the photosensitive member is subjected to an alternating electric field at the developing position. The latent image formed on 20 is subjected to 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 upper seal 520 and is collected in the developing device without being scraped off by the upper seal 520. Further, the toner T still remaining on the developing roller 510 can be peeled off by the toner supply roller 550.

=== Effectiveness of Developing Roller 510 According to this Embodiment ===
As described above, the developing roller 510 according to the present embodiment includes a plurality of regularly arranged convex portions 512 on the surface, and the convex portions 512 are not convex from the top surface 513 of the convex portion 512. A side portion 514 having a stepped side portion 514 connected to the portion 515 and having a flat step surface 514a positioned between the top surface 513 and the non-convex portion 515 in the radial direction of the developing roller 510. is doing. This makes it possible to improve the rolling property of the toner.

  That is, as described in the section of the problem to be solved by the invention, when designing the shape or the like of the convex portion 512 described above, a sufficient amount of toner is carried on the surface of the developing roller 510. For example, it should be noted that the surface area of the surface on which the toner is carried has a sufficiently large value. For this purpose, the height from the non-convex portion 515 of the top surface 513 provided in the convex portion 512 needs to be increased to some extent.

  However, when the height is increased, there is a problem that the rolling property of the toner is deteriorated. Here, the problem will be described with reference to FIG. FIG. 12 is an explanatory diagram for explaining a problem that has occurred in the developing roller 510 according to the conventional example.

  As shown in FIG. 12, when the height of the top surface 513 from the non-convex portion 515 is large, the side portion 514 of the convex portion 512 that continues from the top surface 513 to the non-convex portion 515 becomes a wall and is non-convex It becomes difficult for the toner located in the portion 515 to move to the top surface 513. Therefore, the rolling property of the toner is deteriorated, and as a result, the problem that the charging property of the toner becomes inappropriate occurs.

  On the other hand, the developing roller 510 according to the present embodiment solves the above problem. This will be described with reference to FIG. FIG. 13 is an explanatory diagram for explaining the effectiveness of the developing roller 510 according to the present embodiment.

  As shown in FIG. 13, the developing roller 510 according to the present embodiment has a stepped shape having a flat step surface 514a located between the top surface 513 and the non-convex portion 515 in the radial direction of the developing roller 510. Side portions 514 are provided. The flat stepped surface 514a functions as an intermediate landing when the toner moves from the non-convex portion 515 to the top surface 513, so that the toner positioned on the non-convex portion 515 moves to the top surface 513. It becomes easy to do. Therefore, the rolling property of the toner is improved, and as a result, the problem that the charging property of the toner becomes inappropriate is prevented.

=== Method for Manufacturing Developing Device ===
Next, a method for manufacturing the developing device will be described with reference to FIGS. 14A to 17. 14A to 14E are schematic views showing the transition of the developing roller 510 in the manufacturing process of the developing roller 510. FIG. 15 is an explanatory diagram for explaining the rolling process of the developing roller 510. FIG. 16A and FIG. 16B are schematic diagrams showing a state in which the groove 680 is formed by the convex portions 650a and 652a of the round dies 650 and 652. FIG. 17 is a flowchart for explaining a method of assembling the yellow developing device 54. When the developing device is manufactured, after the housing 540, the holder 526, the developing roller 510, the toner supply roller 550, the regulating blade 560, etc. are manufactured, the developing device is assembled using these members. To be implemented. In this section, the manufacturing method of the developing roller 510 among the manufacturing methods of these members will be described first, and then the developing device assembly method will be described. In the following description, among the black developing device 51, the magenta developing device 52, the cyan developing device 53, and the yellow developing device 54, the yellow developing device 54 will be described as an example.

<<< About Manufacturing Method of Developing Roller 510 >>>
Here, a method for manufacturing the developing roller 510 will be described with reference to FIGS. 14A to 16B.

First, as shown in FIG. 14A, a pipe material 600 as a base material of the developing roller 510 is prepared. The wall thickness of the pipe material 600 is 0.5 to 3 mm.
Next, as shown in FIG. 14B, flange press-fit portions 602 are formed at both ends in the longitudinal direction of the pipe material 600. The flange press-fit portion 602 is made by cutting.
Next, as shown in FIG. 14C, the flange 604 is press-fitted into the flange press-fit portion 602. In order to ensure the fixing of the flange 604 to the pipe material 600, the flange 604 may be bonded or welded to the pipe material 600 after the flange 604 is press-fitted.
Next, as shown in FIG. 14D, centerless polishing is performed on the surface of the pipe member 600 into which the flange 604 is press-fitted. The centerless polishing is performed over the entire surface, and the 10-point average roughness Rz of the surface after the centerless polishing is 1.0 μm or less.
Next, as shown in FIG. 14E, the pipe material 600 into which the flange 604 is press-fitted is subjected to a rolling process. In the present embodiment, so-called through-feed rolling (also called step rolling or through rolling) using two round dies 650 and 652 is performed.

  That is, as shown in FIG. 15, two round dies 650 and 652 arranged so as to sandwich the pipe material 600 as a work are placed on the pipe material 600 with a predetermined pressure (the direction of the pressure in FIG. The two round dies 650 and 652 are rotated in the same direction (refer to FIG. 15) in a state where they are pressed with a symbol P). In the through feed rolling, as the round dies 650 and 652 are rotated, the pipe material 600 is rotated in the direction opposite to the rotation direction of the round dies 650 and 652 (see FIG. 15). Move in the direction shown. Protrusions 650 a and 652 a for forming grooves 680 are provided on the surfaces of the round dies 650 and 652, and the grooves 680 are formed in the pipe material 600 by deforming the pipe material 600 by the protrusions 650 a and 652 a. Is formed.

  In the present embodiment, the groove 680 is formed twice on the pipe material 600 so that the convex portion 512 having the stepped side portions 514 described above is appropriately formed on the surface of the developing roller 510. The process is divided into two steps. First, in the first step, as shown in FIG. 16A, shallow grooves 680 are formed using round dies 650 and 652 having wide convex portions 650a and 652a. Next, in the second step, as shown in FIG. 16B, the round dies 650 and 652 are changed to round dies 650 and 652 having narrow convex portions 512, and the changed round dies 650 and 652 are changed. A deep groove 680 is formed.

  Then, after the rolling process is finished, the surface of the central portion 510a is plated. In the present embodiment, electroless Ni—P plating is used as the plating, but is not limited to this, and for example, hard chrome plating or electroplating may be used.

<<< Assembly Method of Yellow Developing Device 54 >>>
Next, a method for assembling the yellow developing device 54 will be described with reference to FIG.
First, the housing 540, the holder 526, the developing roller 510, the regulating blade 560 and the like described above are prepared (step S2).
Next, the regulating blade 560 is fixed to the holder 526 by screwing the regulating blade 560 to the regulating blade support 526c of the holder 526 (step S4). Note that the end seal 574 described above is attached to the regulating blade 560 in advance before the step S4.
Next, the developing roller 510 is attached to the holder 526 to which the regulating blade 560 is fixed (step S6). At this time, the developing roller 510 is attached to the holder 526 so that the regulating blade 560 comes into contact with the other end of the developing roller 510 in the axial direction. Note that the above-described upper seal 520 is attached to the holder 526 in advance before the step S6.
Then, the assembly of the yellow developing device 54 is completed by attaching the holder 526 to which the developing roller 510, the regulating blade 560, and the like are attached to the housing 540 via the housing seal 546 (step S8). The toner supply roller 550 described above is previously attached to the housing 540 before step S8.

=== Other Embodiments ===
The developer carrying roller and the like according to the present invention have been described 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. It is not a thing. The present invention can be changed and improved without departing from the gist thereof, and the present invention includes the equivalents thereof.

  In the above embodiment, an 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, such as a full color laser beam printer, a monochrome laser beam printer, a copying machine, and a facsimile. The present invention can be applied to various image forming apparatuses.

  Also, the photosensitive member is not limited to a so-called photosensitive roller, which is configured by providing a photosensitive layer on the outer peripheral surface of a cylindrical conductive substrate, and is configured by providing a photosensitive layer on the surface of a belt-shaped conductive substrate. A so-called photosensitive belt may be used.

In the above embodiment, the depth L2 of the step surface 514a in the depth direction is equal to or larger than the volume average particle diameter of the toner T, but the present invention is not limited to this. It may be smaller than the volume average particle size.
However, the stepped surface 514a can sufficiently serve as an intermediate landing when the toner moves from the non-convex portion 515 to the top surface 513, and the rolling property of the toner is further improved. The above embodiment is more desirable.

Further, in the above embodiment, the side portion 514 is provided with a plurality of steps, and the height of at least one of the plurality of steps is equal to or less than the volume average particle diameter of the toner. However, the present invention is not limited to this. For example, the height of the plurality of steps may be larger than the volume average particle diameter of the toner.
However, the toner located on the non-convex portion 515 is more smoothly moved to the top surface 513 via the step surface 514a, and the rolling property of the toner is further improved. Is preferable.

  As realized in the developing roller 510 according to the above-described embodiment, it is even more desirable when the heights of the plurality of steps are all equal to or greater than the volume average particle diameter of the toner.

  In the above embodiment, the top surface 513 is a quadrangle, and the convex portion 512 has the four side portions 514 corresponding to the sides of the quadrangle. However, the present invention is not limited to this. . For example, the top surface 513 may be circular, and the convex portion 512 may include the side portion 514 corresponding to the outer periphery of the circular shape.

In the above embodiment, the normal direction A1 of the step surface 514a is along the normal direction A2 of the top surface 513. However, the present invention is not limited to this. For example, the normal direction A1 of the step surface 514a may not be along the normal direction A2 of the top surface 513, and the step surface 514a may be inclined.
However, the stepped surface 514a can sufficiently serve as an intermediate landing when the toner moves from the non-convex portion 515 to the top surface 513, and the rolling property of the toner is further improved. The above embodiment is more desirable.

  In the above embodiment, the height of the top surface 513 from the non-convex portion 515 is not more than twice the volume average particle diameter of the toner. However, the present invention is not limited to this. The height of the surface 513 from the non-convex portion 515 may be larger than twice the volume average particle diameter of the toner.

  When the height of the top surface 513 from the non-convex portion 515 is equal to or less than twice the volume average particle diameter of the toner, most of the toner positioned between the developing roller 510 and the regulating blade 560 is developed by the developing roller. Since the toner contacts at least one of 510 and the regulating blade 560, the chargeability of the toner becomes appropriate. In this respect, the above embodiment is more desirable. When the height is equal to or less than the volume average particle diameter (one time) of the toner, most of the toner positioned between the developing roller 510 and the regulating blade 560 is mostly the developing roller 510 and the regulating blade 560. It is even more desirable because it will be in contact with both.

  In the above-described embodiment, the top surface 513, the step surface 514a, and the non-convex portion 515 are all toner carrying portions for carrying toner, but are not limited thereto. . For example, only the step surface 514a and the non-convex portion 515 may be the toner carrying portion.

  In the above-described embodiment, the regulation blade 560 regulates the layer thickness when the flat surface of the regulation blade 560 comes into contact with the developing roller 510. However, the invention is not limited to this. For example, the regulation blade 560 may regulate the layer thickness when the edge of the regulation blade 560 contacts the developing roller 510.

=== 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. 18 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 706, 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 706, 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. Disk) etc. may be used.

  FIG. 19 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, the example in which the printer 706 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 a computer 702 and a printer 706, 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 706 may have a part of the functions or mechanisms of the computer 702, the display device 704, the input device 708, and the reading device 710. As an example, the printer 706 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 constituting the printer. FIG. 2 is a block diagram illustrating a control unit of the printer 10 in FIG. 1. It is a conceptual diagram of a developing device. It is sectional drawing which showed the main components of the image development apparatus. 3 is a schematic perspective view of a developing roller 510. FIG. 2 is a schematic front view of a developing roller 510. FIG. It is the schematic diagram which showed the shape of the convex part 512. FIG. 5 is a perspective view of a restriction blade 560. FIG. FIG. 5 is a perspective view of a holder 526. FIG. 5 is a perspective view showing a state where an upper seal 520, a regulating blade 560, and a developing roller 510 are assembled to a holder 526. FIG. 6 is a perspective view showing a state in which a holder 526 is attached to a housing 540. It is explanatory drawing for demonstrating the problem which generate | occur | produced in the developing roller 510 which concerns on a prior art example. It is explanatory drawing for demonstrating the effectiveness of the developing roller 510 which concerns on this Embodiment. 14A to 14E are schematic views showing the transition of the developing roller 510 in the manufacturing process of the developing roller 510. FIG. 6 is an explanatory diagram for explaining a rolling process of the developing roller 510. FIG. 16A and FIG. 16B are schematic diagrams showing a state in which the groove 680 is formed by the convex portions 650a and 652a of the round dies 650 and 652. 4 is a flowchart for explaining a method of assembling the yellow developing device 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

DESCRIPTION OF SYMBOLS 10 Laser beam printer 20 Photoconductor 30 Charging unit 40 Exposure unit 50 YMCK developing unit 50a Center axis 51 Black developing device 52 Magenta developing device 53 Cyan developing device 54 Yellow developing device 55a, 55b, 55c, 55d Holding part 60 Primary transfer unit 70 Intermediate transfer body 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 Main controller 102 Unit controller 112 Interface 113 Image memory 510 Developing roller 510a Central part 510b Shaft portion 512 Convex portion 513 Top surface 514 Side portion 514a Step surface 514b First inclined surface 514c Second inclined surface 5 15 Non-convex part 520 Upper seal 520a Short end 520b Contact surface 520c Opposite surface 524 Upper seal urging member 526 Holder 526a Upper seal support part 526b Development roller support part 526c Restriction blade support part 530 Toner container 530a First Toner accommodating portion 530b Second toner accommodating portion 540 Housing 542 Upper housing portion 544 Lower housing portion 545 Partition wall 546 Housing seal 550 Toner supply roller 560 Restriction blade 560a Tip 562 Rubber portion 562a Contact portion 564 Rubber support portion 564a Thin plate 564b Thin plate support Portion 564c Both ends in the longitudinal direction 564d One end portion in the short direction 564e The other end portion in the short direction 572 Opening 574 End seal 576 Bearing 600 Pipe material 602 Flange press-fit portion 604 Flange 650 Round die 650a Convex portion 652 Round die 652a Convex portion 680 Groove 700 Image forming system 702 Computer 704 Display device 706 Printer 708 Input device 708A Keyboard 708B Mouse 710 Reading device 710A Flexible disk drive device 710B CD-ROM drive device 802 Internal memory 80 Drive unit T Toner

Claims (10)

A developer carrying roller for carrying a developer having a plurality of regularly arranged convex portions on the surface,
The convex portion is surrounded by a non-convex portion formed in a mesh shape,
A stepped sides from the top surface of the convex portion continuing to the non-convex portion, a flat stage surface positioned between the top surface and the non-protruding portion in the radial direction of the developer bearing roller, Side with,
And a developer carrying roller. The developer carrying roller according to claim 1,
The developer carrying roller, wherein a top surface of the convex portion has a planar shape. In the developer carrying roller according to claim 1 or 2 ,
The top surface is square;
The developer carrying roller, wherein the convex portion has four side portions corresponding to the sides of the quadrangle. The developer carrying roller according to any one of claims 1 to 3 ,
The developer carrying roller, wherein a normal direction of the step surface is along a normal direction of the top surface. A developer carrying roller for carrying a developer having a plurality of regularly arranged convex portions on the surface,
The convex portion is surrounded by a non-convex portion formed in a mesh shape,
A stepped sides from the top surface of the convex portion continuing to the non-convex portion, a flat stage surface positioned between the top surface and the non-protruding portion in the radial direction of the developer bearing roller, Side with,
A developer carrying roller having
A developing device comprising: The developing device according to claim 5 ,
The developer is granular,
The developing device according to claim 1, wherein a width of the step surface in a depth direction is equal to or larger than a volume average particle diameter of the developer . In the developing device according to claim 5 or 6 ,
The developer is granular,
The side portion is provided with a plurality of steps.
The height of at least one step among the plurality of steps is not more than the volume average particle diameter of the developer . The developing device according to any one of claims 5 to 7 ,
The developer is granular,
The height of the top surface from the non-convex portion is not more than twice the volume average particle diameter of the developer . A developer carrying roller for carrying a developer having a plurality of regularly arranged convex portions on the surface, the convex portions being surrounded by a non-convex portion formed in a mesh shape , a stepped sides from the top surface of the convex portion continuing to the non-convex portion, the planar step surface located between the top surface in the radial direction of the developer carrying roller and said non-convex portion A developer carrying roller having a side portion,
An image forming apparatus comprising: a developing device comprising: Computer and
An image forming apparatus connectable to the computer, comprising a plurality of regularly arranged convex portions on a surface, a developer carrying roller for carrying a developer, wherein the convex portions are meshed. Jo is surrounded by a non-convex portion formed on, a step-like side portions from the top surface of the convex portion continuing to the non-convex portion, the said top surface in a radial direction of said developer carrying roller An image forming apparatus having a developing device having a developer carrying roller having a side portion provided with a flat stepped surface located between the non-convex portions;
An image forming system comprising:

Images