JP5067488B2 - Toner particle carrying roller, developing device, image forming apparatus, and image forming system - Google Patents

Description

The present invention relates to a toner particle 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, 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 (toner particles). Then, 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 develops the latent image carried on the image carrier. Development is performed with toner particles in the apparatus to form a toner image, the toner image is transferred to a medium, and finally an image is formed on the medium.

  In order to realize the above-described function of developing the latent image carried on the image carrier, the developing device carries toner particles on the surface and is carried on the image carrier by the toner particles. A toner particle carrying roller for developing the latent image is provided. Some developing devices have convex portions formed on the surface of the toner particle carrying roller in order to properly carry the toner particles.

JP 2003-263018 A

  However, when a convex portion is formed on the surface of the toner particle carrying roller, a force may act on the local portion of the toner particle from the convex portion depending on the shape of the convex portion. For example, when the convex portion is sharp, when the convex portion comes into contact with the toner particles, force may concentrate on the local portion of the toner particles from the convex portion. As described above, when the force concentrates on the local portion of the toner particle from the convex portion, the toner particle may be deformed or the toner particle may be broken due to the force.

The present invention has been made in view of such problems, and an object of the present invention is to realize a toner particle carrying roller, a developing device, an image forming apparatus, and an image forming system capable of suppressing deformation of toner particles. There is.

In order to solve the above-mentioned problems, a main aspect of the present invention is a toner carrying toner particles to which electric charges are applied by a layer thickness regulating member that contacts a toner particle carrying roller in order to develop a latent image formed on an image carrier. A particle carrying roller, wherein the toner particle carrying roller has a plurality of convex portions surrounded by two kinds of groove portions intersecting each other on the surface, the top surface of the convex portion is flat, and the top surface Is not less than the volume average particle diameter of the toner particles, and the convex portion has a side surface connected to the top surface, and the connecting portion between the top surface and the side surface has no edge, A toner particle carrying roller having roundness. (However, the toner particle carrying roller whose surface is blasted is excluded) .

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

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. FIG. 5 is a schematic perspective view of the developing roller 510, and is a view showing a spiral first groove 518a and a second groove 518b having different winding directions. 2 is a schematic front view of a developing roller 510. FIG. FIG. 7 is a schematic view showing the surface of the developing roller 510, and is an enlarged view of a portion A shown in FIG. It is a schematic diagram showing the cross-sectional shape of a convex portion 519 and a concave portion 518. 5 is a flowchart showing a method for manufacturing the developing roller 510. FIG. 10 is a schematic diagram showing a 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. It is a figure for demonstrating the pitch in a screen and a latent image. FIG. 10 is a diagram showing a modification of the developing roller 510, and a schematic diagram showing a cross-sectional shape of a convex portion 519. 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.

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

(A1) a toner particle carrying roller for carrying toner particles on its surface and developing a latent image carried on the image carrier by the toner particles, (a2) a convex portion provided on the surface; And (b) a toner particle carrying roller having a top surface having a flat portion and a convex portion having a width of the top surface equal to or larger than the volume average particle diameter of the toner particles. Developing device.
According to such a developing device, when the top surface having a flat portion and the width is equal to or larger than the volume average particle diameter of the toner particles comes into contact with the toner particles, from the convex portion (top surface). A force is dispersed and acts on the toner particles. For this reason, according to the above-described developing device, it is possible to suppress the force from concentrating and acting on the local portion of the toner particle from the convex portion, and thus it is possible to suppress the deformation of the toner particle caused by the force. .

In the developing device, the toner particle carrying roller may have a cylindrical portion having the surface, and the cylindrical portion may be made of a single material.
In such a case, it is possible to easily realize the toner particle carrying roller having the above-described convex portion.

Further, in this developing device, the layer thickness of the toner particles carried on the toner particle carrying roller in contact with the toner particle carrying roller from one end to the other end in the axial direction of the toner particle carrying roller. The layer thickness regulating member may regulate the layer thickness by contacting a flat surface of the layer thickness regulating member with the toner particle carrying roller.
When the layer thickness is regulated by the flat surface of the layer thickness regulating member coming into contact with the toner particle carrying roller, the toner particles are pressed toward the convex portion (top surface) by the layer thickness regulating member. The force tends to act on the toner particles from the convex portion. Therefore, in the above case, the effect of providing the convex portion having the top surface on the surface of the toner particle carrying roller, that is, the effect of suppressing the deformation of the toner particles and the like is more effectively exhibited.

  Further, in the developing device, the surface is provided with a spiral groove portion that is inclined with respect to the axial direction and the circumferential direction of the toner particle carrying roller and is formed at an equal pitch in the axial direction. Two types of groove portions may be formed with different inclination angles, and the convex portion may be provided surrounded by the two types of groove portions.

In the developing device, the convex portion may include a side surface connected to the top surface, and the connecting portion between the top surface and the side surface may be rounded.
When the top surface and the side surface are rounded, no edge is formed at the joint, so that the force acting on the toner particles from the joint can be reduced. For this reason, in the above case, deformation of the toner particles can be suppressed.

In the developing device, the radius of curvature of the roundness may be half or more than the volume average particle diameter of the toner particles.
When the radius of curvature of the roundness is smaller than half of the volume average particle diameter of the toner particles (that is, the average radius of the toner particles), the roundness bites into the toner particles when the toner particles come into contact with the roundness. The force may concentrate on the local area of the toner particles. On the other hand, when the radius of curvature of the roundness is more than half of the volume average particle diameter of the toner particles, there is no possibility that the roundness will bite into the toner particles, so that force acts from the roundness to the toner particles. For this reason, in the above case, deformation of the toner particles can be suppressed.

In the developing device, an inclination angle of the side surface provided on the convex portion from a bottom surface of the groove portion may be 45 degrees or less.
In such a case, when the toner particles come into contact with the side surface, the force component vertically upward of the force received from the side surface is equal to or greater than the force component in the horizontal direction. For this reason, in the above case, the toner particles can easily move up to the top surface by the force component vertically upward, so that it is possible to suppress a decrease in rolling properties of the toner particles.

In the developing device, both the convex portion and the groove portion may be carrying portions for carrying the toner particles.
In such a case, since the force easily acts on the toner particles carried on the convex portions that are the carrying portions, the effect of providing the convex portions on the surface of the toner particle carrying roller, that is, the toner particles The effect of suppressing deformation and the like is more effectively exhibited.

In the developing device, the depth of the groove may be not more than twice the volume average particle diameter of the toner particles.
In such a case, since most of the toner particles positioned between the toner particle carrying roller and the layer thickness regulating member in the groove portion are in contact with at least one of the toner particle carrying roller and the layer thickness regulating member, The chargeability of the toner particles becomes appropriate.

Further, in this developing device, the latent image has a dot-like latent image formed in a region partitioned in a lattice shape, and the lattice can be formed at a plurality of types of pitches in the axial direction. The pitch of the groove portion in the axial direction may be smaller than the longest pitch among a plurality of types of pitches in the lattice.
On the surface of the toner particle carrying roller, the groove portion has a larger amount of toner particles carried at portions other than the groove portion and the groove portion. For this reason, when the latent image is developed, the density of the portion facing the groove may slightly increase. When the pitch in the axial direction of the groove portion is larger than the longest pitch among the plurality of types of pitches in the lattice, the toner is generated when the dot-like latent image formed in the region partitioned in the lattice shape is developed. Dots formed at a portion including the groove portion of the particle carrying roller and dots formed at a portion not including the groove portion are generated. In this case, periodic density unevenness occurs in the toner image in which the latent image is developed. However, according to the developing device as described above, each dot developed from each dot-like latent image is formed at a portion including the groove portion of the toner particle carrying roller. For this reason, it is possible to suppress the occurrence of density unevenness due to the groove in the developed toner image.

(A1) a toner particle-carrying roller that carries toner particles on the surface thereof and develops a latent image carried on the image carrier by the toner particles, and (a2) a convex portion provided on the surface A toner particle carrying roller having a top surface having a flat portion and a convex portion having a width of the top surface equal to or larger than the volume average particle diameter of the toner particles, (b), (c) ) The toner particle carrying roller has a cylindrical portion with the surface, and the cylindrical portion is made of a single material, and (d) extends from one axial end portion to the other end portion of the toner particle carrying roller. A layer thickness regulating member that contacts the toner particle carrying roller and regulates the layer thickness of the toner particles carried on the toner particle carrying roller, and the layer thickness regulating member includes: A flat surface having contact with the toner particle carrying roller And (e) spiral grooves formed on the surface at an equal pitch in the axial direction and inclined with respect to the axial direction and the circumferential direction of the toner particle carrying roller, The groove portions are formed in two types with different angles of inclination, the convex portions are provided surrounded by the two types of groove portions, and (f) the convex portions are formed on the top. (G) a radius of curvature of the roundness is not less than half of the volume average particle diameter of the toner particles, and the roundness is formed at the joint between the top surface and the side surface. h) The inclination angle of the side surface provided on the convex portion from the bottom surface of the groove portion is 45 degrees or less, and (i) the convex portion and the groove portion both carry the toner particles. (J) the depth of the groove is the volume of the toner particles (K) The latent image has a dot-like latent image formed in a region partitioned in a lattice shape, and the lattice is formed at a plurality of types of pitches in the axial direction. The developing device characterized in that the pitch of the groove portion in the axial direction is smaller than the longest pitch among a plurality of types of pitches in the lattice.
According to such a developing device, an effect capable of suppressing deformation of toner particles and the like is most effectively exhibited.

And a toner particle carrying roller for carrying toner particles on the surface and developing a latent image carried on the image carrier by the toner particles, the convex portion provided on the surface, and a flat portion. And a convex portion having a width of the top surface equal to or larger than a volume average particle diameter of the toner particles.
According to such a toner particle carrying roller, the force acting on the toner particles from the convex portion acts in a dispersed manner on the toner particles, so that the force can be prevented from acting on the local portions of the toner particles. As a result, the toner Particle deformation and the like can be suppressed.

(A) an image carrier for carrying a latent image; and (b) a toner particle carrying roller for carrying toner particles on the surface thereof and developing the latent image carried on the image carrier by the toner particles. And a convex portion provided on the surface, the convex portion having a top surface having a flat portion, and the width of the top surface being equal to or larger than the volume average particle diameter of the toner particles. An image forming apparatus comprising: a developing device including a toner particle carrying roller; and (c).
According to such an image forming apparatus, since the force acting on the toner particles from the convex portion acts on the toner particles in a dispersed manner, it is possible to prevent the force from acting on the local portions of the toner particles. As a result, the toner particles It is possible to suppress deformation and the like.

(A) a computer and (B) an image forming apparatus connectable to the computer, (a) an image carrier for carrying a latent image, and (b) carrying toner particles on the surface thereof. A toner particle carrying roller that develops the latent image carried on the image carrier by the toner particles, the toner particle carrying roller having a top surface that is a convex portion provided on the surface and has a flat portion; A developing device including a toner particle carrying roller having a convex portion whose width of the top surface is not less than the volume average particle diameter of the toner particles, and an image forming apparatus having (c). An image forming system.
According to such an image forming system, since the force acting on the toner particles from the convex portion acts on the toner particles in a dispersed manner, it is possible to prevent the force from acting on the local portions of the toner particles. As a result, the toner particles It is possible to suppress deformation and the like.

Further, a method for producing a toner particle carrying roller for carrying toner particles on its surface and developing a latent image carried on the image carrier by the toner particles, comprising a top surface having a flat portion, and Forming a convex portion having a width of the top surface equal to or larger than the volume average particle diameter of the toner particles on the surface by rolling.
According to such a method for manufacturing a toner particle carrying roller, it is possible to produce a toner particle carrying roller capable of suppressing deformation of toner particles.

=== 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.

<<< Configuration Example of 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, and a primary unit along the rotation direction of the photoconductor 20 as an example of an “image carrier”. A transfer unit 60, an intermediate transfer body 70, a cleaning unit 75, a secondary transfer unit 80, a fixing unit 90, a display unit 95 including a liquid crystal panel that serves as a notification unit for a user, and these units are provided. It has a control unit 100 that controls and controls 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 for emitting a laser beam as light, a polygon mirror unit that rotates a polygonal polygon mirror, and a plurality of types of lenses such as an F-θ lens. Based on an image signal input from a host computer (not shown) such as a word processor, the modulated photoconductor 20 is irradiated with a modulated laser beam. At this time, the laser beam emitted from the semiconductor laser is applied to the polygon mirror. The laser beam applied to the polygon mirror scans the photoreceptor 20 through the lens while changing the reflection angle by the rotation of the polygon mirror. Then, the laser beam is turned on / off at a predetermined timing, and a dot-like latent image is formed in a grid-divided area on the photoreceptor 20 that rotates at a predetermined speed. These dot-like latent images constitute a latent image. Here, since the dot-like latent image forms a latent image, it cannot be seen with the naked eye.

  The YMCK developing unit 50 converts the latent image formed on the photoconductor 20 into toner particles (hereinafter simply referred to as toner T) accommodated in the developing device, that is, black (K) accommodated in the black developing device 51. Development is performed using toner, magenta (M) toner stored in the magenta developing device 52, cyan (C) toner stored in the cyan developing device 53, and yellow (Y) toner stored in the yellow developing device 54. It is a device for.

  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.

<<< Example of Operation of Printer 10 >>>
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.

=== Overview of Developing Device ===
Next, a configuration example and an operation example of the developing device will be described with reference to FIGS. 3 and 4. FIG. 3 is a conceptual diagram of the developing device. FIG. 4 is a cross-sectional view showing main components of the developing device. 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.

  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.

<<< Example of configuration of developing device >>>
The yellow developing device 54 includes a developing roller 510 as an example of a “toner particle carrying roller”, an upper seal 520, a toner container 530, a housing 540, a toner supply roller 550, and a regulating blade 560 as an example of a “layer thickness regulating member”. Etc.

The developing roller 510 carries toner particles (toner T) on its surface and develops a latent image carried on the photoconductor 20 by the toner particles. The developing roller 510 is a member made of an aluminum alloy, an iron alloy, or the like. On the surface of the developing roller 510, a concave portion 518 and a convex portion 519 as examples of the “groove portion” are provided (see FIG. 6). The surface shape of the developing roller 510 will be described in detail later.
Further, as shown in FIG. 3, the developing roller 510 is supported at both ends in the longitudinal direction of the developing device (the axial direction of the developing roller 510), 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.

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. 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 FIG. 4, 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 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. That is, the regulating blade 560 is not in contact with the developing roller 510 at the edge, but in contact with the belly, and the plane (specifically, the plane of the rubber portion 562) of the regulating blade 560 is the developing roller. The layer thickness is regulated by abutting 510. 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.

<<< Example of operation of developing device >>>
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.

=== Regarding the Surface Shape of the Developing Roller 510 ===
Next, the surface shape of the developing roller 510 will be described with reference to FIGS. FIG. 5 is a schematic perspective view of the developing roller 510, and shows the recess 518. FIG. 6 is a schematic front view of the developing roller 510. FIG. 7 is a schematic view showing the surface of the developing roller 510, and is an enlarged view of a portion A shown in FIG. FIG. 8 is a schematic diagram showing the cross-sectional shapes of the convex portion 519 and the concave portion 518.

  5-7, the axial direction of the developing roller 510 is indicated by an arrow, and in FIG. 8, the longitudinal direction of the first recess 518a is indicated by an arrow. 5 to 8, the scales of the convex portions 519 and the like are different from the actual ones for easy understanding of the drawings. 6 and 7, the direction of the arrow indicated by the symbol X indicates the longitudinal direction of the first recess 518a, and the direction of the arrow indicated by the symbol Y indicates the longitudinal direction of the second recess 518b. Yes. 8 shows a cross section along the longitudinal direction of the first recess 518a indicated by the symbol Y in FIG. In addition, the cross-sectional shape of the convex part 519 and the recessed part 518 when taking the cross section of the convex part 519 and the recessed part 518 along the longitudinal direction of the 2nd recessed part 518b shown by the symbol X of FIG. 6 is also shown in FIG. The cross-sectional shapes of the convex portion 519 and the concave portion 518 are the same.

  As shown in FIGS. 5 and 6, the developing roller 510 has a cylindrical portion 510a and a shaft portion 510b. The cylindrical portion 510a carries toner particles on its surface. The cylindrical portion 510a is made of a single material such as an aluminum alloy, and has a concavo-convex portion 512 and a non-concave portion 514 formed on the surface thereof. The shaft portion 510b is located at both ends in the axial direction of the developing roller 510, and is supported by the housing 540 via a bearing (not shown).

  The concavo-convex portion 512 is a portion located at the center in the axial direction of the developing roller 510, and is provided with concavo-convex processing on the surface in order to properly carry the toner T (the convex portion 519 of the concavo-convex portion 512. And the concave portion 518 both function as a toner carrying portion for carrying toner particles (toner T). In the present embodiment, a so-called rolling process (the rolling process is described in detail in the section of the manufacturing method of the developing roller 510 described later) is used as the uneven process, and the uneven process part is formed by the rolling process. A concave portion 518 and a convex portion 519 are formed on the surface of 512. More specifically, a groove is formed on the surface of the concavo-convex portion 512 by rolling, and thus the concavo-convex portion 512 has a concave portion 518 and a convex portion 519.

  As shown in FIG. 5, the concave portion 518 is a spiral groove portion that is inclined with respect to the axial direction and the circumferential direction of the developing roller 510 and is formed at an equal pitch in the axial direction. The recesses 518 are formed in two types with different inclination angles with respect to the axial direction and the circumferential direction of the developing roller 510 (a first recess 518a and a second recess 518b are formed).

  That is, the first recess 518a is formed in a spiral shape so as to form an angle of 45 degrees counterclockwise with the axial direction of the developing roller 510, and the second recess 518b is clockwise with the axial direction of the developing roller 510. It is formed in a spiral shape so as to form an angle of 45 degrees. For this reason, the angle at which the first recess 518a and the second recess 518b intersect is 90 degrees. Further, the pitches of the first recess 518a and the second recess 518b in the axial direction of the developing roller 510 are formed equally, and in this embodiment, as shown in FIG. 7, it is about 112 μm.

  As shown in FIG. 6, the convex portion 519 is provided so as to be surrounded by the two types of concave portions (that is, the first concave portion 518a and the second concave portion 518b). The convex portion 519 includes a top surface 519a and a side surface 519b connected to the top surface 519a.

  As shown in FIG. 8, the top surface 519a has a flat portion. The top surface 519a has a substantially square shape as shown in FIG. The top surface 519a is arranged such that one of the two diagonal lines of the top surface 519a is along the axial direction of the developing roller 510 and the other diagonal line is along the circumferential direction of the developing roller 510. Is formed. Further, the width H of the top surface 519a is not less than the volume average particle diameter (7 μm) of the toner particles, and is about 30 μm in this embodiment.

  As shown in FIG. 8, the side surface 519b is a slope that is also connected to the flat bottom surface 518c of the recess 518 and is inclined with respect to the bottom surface 518c. The inclination angle of the side surface 519b from the bottom surface 518c of the recess 518 (the angle represented by the symbol β in FIG. 8) is 45 degrees or less, and in the present embodiment, the inclination angle is 45 degrees. .

  Moreover, as shown in FIG. 8, the roundness 519d is formed in the connection part 519c of the top surface 519a and the side surface 519b. The curvature radius of the roundness 519d is not less than half of the volume average particle diameter (7 μm) of the toner particles, and in this embodiment is 20 μm. In the present embodiment, the cross-sectional shape of the roundness 519d is an arc connecting the top surface 519a and the side surface 519b as shown in FIG. At this time, the radius of curvature is the same as the radius of the arc.

  Further, the height of the convex portion 519 (depth of the concave portion 518), that is, the distance between the top surface 519a of the convex portion 519 and the bottom surface 518c of the concave portion 518 is not more than twice the volume average particle size (7 μm) of the toner particles. It is. In this embodiment, since the depth of the recess 518 is about 7 μm, it is the same size as the volume average particle diameter of the toner particles. Further, the width of the recess 518 is about 30 μm, and the groove angle (the angle represented by the symbol α in FIG. 8) is about 90 degrees.

  As shown in FIG. 6, the non-recessed portion 514 is a portion where the aforementioned unevenness processing (rolling process) is not applied to the surface. The non-concavo-convex processed portion 514 is located between the uneven processed portion 512 and the shaft portion 510b in the axial direction of the developing roller 510, and the surface thereof is smooth (the ten-point average roughness of the surface). Rz is 1 μm or less).

=== About Manufacturing Method of Developing Roller 510 ===
Next, a method for manufacturing the developing roller 510 having the above-described surface shape (concave portion 518 and convex portion 519) will be described with reference to FIGS. 9, 10A to 10E, and FIG. FIG. 9 is a flowchart showing a method for manufacturing the developing roller 510. FIGS. 10A to 10E are schematic views showing the transition of the developing roller 510 in the manufacturing process of the developing roller 510. FIG. 11 is an explanatory diagram for explaining the rolling process of the developing roller 510. 10A to 10C show a cross section of the pipe material 600, and FIGS. 10D and 10E show the outer periphery of the pipe material 600, respectively.

First, as shown in FIG. 10A, a pipe material 600 is prepared as a base material of the cylindrical portion 510a of the developing roller 510 (step s102). The wall thickness of the pipe material 600 is 0.5 to 3 mm.
Next, as shown in FIG. 10B, flange press-fit portions 602 are formed at both longitudinal ends of the pipe material 600 (step s104). The flange press-fit portion 602 is made by cutting.
Next, as shown in FIG. 10C, the flange 604 constituting the shaft portion 510b of the developing roller 510 is press-fitted into the flange press-fitting portion 602 (step s106). 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. 10D, centerless polishing is performed on the surface of the pipe member 600 into which the flange 604 is press-fitted (step s108). 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. 10E, a concave portion 518 and a convex portion 519 are formed by rolling in a portion corresponding to the concave and convex portion 512 of the pipe member 600 into which the flange 604 is press-fitted (step s110). 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. 11, 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. 11). The two round dies 650 and 652 are rotated in the same direction (see FIG. 11) in a state of being pressed with a symbol P). The surfaces of the round dies 650 and 652 are provided with projections 650a and 652a for forming the recesses 518, and the projections 650a and 652a deform the pipe material 600, thereby causing the pipe material 600 to protrude with the recesses 518 and Part 519 is formed. 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. 11). Move in the direction indicated by H. In the portion corresponding to the concave and convex portion 512, the first concave portion 518a of the concave portion 518 is formed by the convex 650a of the round die 650, and the second concave portion 518b is formed by the convex 652a of the round die 652. It becomes. Further, as described above, the round portion 519d (FIG. 8) is formed in the joint portion 519c of the convex portion 519 of the developing roller 510, but the convex 650a and the convex 652a of the round die are shapes that form the round 519d. It has become.

  In the manufacturing method of the developing roller 510 described above, the surface of the developing roller 510 is provided with a top surface 519a having a flat portion by the rolling process (step s110), and the width of the top surface 519a is made of toner particles. A convex portion 519 having a volume average particle diameter or more is formed.

=== Effectiveness of Developing Device According to this Embodiment ===
As described above, the toner particle carrying roller (developing roller 510) of the developing devices 51, 52, 53, and 54 according to the present embodiment includes a top surface 519a having a flat portion as shown in FIG. The top surface 519a has a convex portion 519 having a width H equal to or larger than the volume average particle diameter of the toner particles. Thereby, deformation of the toner particles and the like can be suppressed. This will be described in detail below.

  When a convex portion is formed on the surface of the developing roller 510, a force may be applied from the convex portion to the local portion of the toner particles depending on the shape of the convex portion. For example, when the convex portion is sharp, when the convex portion comes into contact with the toner particles, force may concentrate on the local portion of the toner particles from the convex portion. As described above, when the force concentrates on the local portion of the toner particle from the convex portion, the toner particle may be deformed or the toner particle may be broken due to the force.

  On the other hand, as in the present embodiment, when a convex portion 519 provided with a top surface 519a having a flat portion and the width of the top surface 519a is equal to or larger than the volume average particle diameter of the toner particles is provided. When the top surface 519a comes into contact with the toner particles, the force acts from the convex portion 519 (top surface 519a) to the toner particles. For this reason, according to the developing roller 510 according to the present embodiment, it is possible to suppress the force from concentrating on the local portion of the toner particles from the convex portion 519, and therefore, deformation of the toner particles caused by the force is suppressed. It becomes possible.

=== Relationship Between Recess 518 and Latent Image ===
By the way, the laser beam printer forms a latent image on the photoconductor 20 using the laser beam as described above, and visualizes the formed latent image as a toner image by the toner carried on the developing roller 510. At this time, a dot-like latent image is formed on a so-called screen on the photosensitive member 20 by turning ON / OFF the laser beam scanned in the main scanning direction. These dot-like latent images constitute a latent image.

  Further, in the case of the developing roller 510 having the clearly-determined concave portion 518 and convex portion 519 as in this embodiment, for example, more toner particles T may enter the concave portion 518 than the convex portion 519. There is. In this case, in the toner image, the density may be different between the portion developed by the concave portion 518 and the portion developed by the convex portion 519. In particular, an image having no large area, such as a character or a line drawing, has little influence, but in the case of an image having a large area such as a photograph or an illustration, uneven density may be noticeable. Such a phenomenon occurs when the pitch in the axial direction of the recesses 518 formed in the developing roller 510 is larger than the pitch of the lattice in the main scanning direction of the screen described above (the direction corresponding to the axial direction of the developing roller 510). It becomes more prominent. This is because even if the dots should originally be formed with the same density, the density differs depending on whether the dots are developed in the concave portion 518 of the developing roller 510 or the convex portion 519.

  Therefore, in the developing roller 510 of the present embodiment, the pitch of the recesses 518 in the axial direction is made smaller than the longest pitch of the lattice when forming an image having an area such as a photograph or illustration. Here, the pitch of the grating in the main scanning direction (direction corresponding to the axial direction of the developing roller 510) of the latent image when forming an image having a large area such as a photograph or illustration is the highest resolution that can be formed by the laser beam printer. (That is, the grid can be formed with a plurality of types of pitches in the main scanning direction (axial direction)). This is because when a laser beam printer forms an image with a large area such as a photograph or illustration, dots are formed at a resolution lower than the maximum resolution of the printer, and each dot has gradation. This is to improve the overall image quality.

  FIG. 12 is a diagram for explaining pitches in the screen and the latent image. As shown in the figure, for example, if the maximum resolution of the printer is 600 dpi (pitch 42.5 μm) and the resolution of the latent image is 600 dpi, the area where the dot-like latent image can be formed is 42.5 μm pitch. Divided into a lattice. For this reason, gradation can be expressed only in each partitioned area with or without a dot-like latent image (the upper part of FIG. 12).

  Therefore, when forming an image having a large area, for example, three dot-like latent images at a resolution of 600 dpi can be used as one dot-like latent image, and the semiconductor laser can respond to three dot-like latent images at a resolution of 600 dpi. The gray scale is expressed by changing the length of time during which the laser beam is emitted within a long time (lower part of FIG. 12). In this case, the resolution when forming an image having a large area is 200 dpi, and the area where the dot-like latent image can be formed is partitioned into a grid of 127.5 μm pitch. For this reason, as shown in FIG. 8, the developing roller 510 of the present embodiment has an area partitioned in a lattice shape of 200 dpi, that is, a 127.5 μm pitch by setting the pitch of the recesses 518 in the axial direction to about 112 μm. Each dot-like latent image formed on the toner image is developed at a portion including the concave portion 518 and the convex portion 519 of the developing roller 510, thereby suppressing the occurrence of density unevenness in the developed toner image. .

  In the present embodiment, the maximum resolution of the laser beam printer is 600 dpi, and the pitch in the axial direction of the area partitioned in a lattice form that can form a dot-like latent image when an image such as a photograph is formed is 127.5 μm. Although an example in which the pitch in the axial direction of the concave portion 518 of the developing roller 510 is 112 μm has been described, the present invention is not limited to this, and the pitch in the axial direction of the concave portion 518 of the developing roller 510 is a latent potential when forming images such as photographs. It suffices that the pitch in the axial direction of the area partitioned in a lattice pattern in which the dot-like latent image is formed by the image is smaller.

=== Other Embodiments ===
The developing device and the like according to the present invention have been described above based on the above embodiment. However, the above-described embodiment is intended to facilitate understanding of the present invention and is not intended to limit the present invention. Absent. 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 toner particles have been described as having a volume average particle diameter of 7 μm. However, the present invention is not limited to this, and the toner particles may have a volume average particle diameter of 5 to 10 μm.

Further, in the above embodiment, as shown in FIG. 5, the developing roller 510 has a cylindrical portion 510a having the surface, and the cylindrical portion 510a is made of a single material. It is not limited to. For example, the cylindrical portion 510a may be made of a plurality of materials.
However, when the cylindrical portion 510a is made of a single material, the developing roller 510 having the convex portion 519 can be easily manufactured. Therefore, the above embodiment is more desirable.

Furthermore, in the above embodiment, as shown in FIG. 4, the developing devices 51, 52, 53, and 54 are in contact with the developing roller 510 from one end to the other end in the axial direction of the developing roller 510, A layer thickness regulating member (regulating blade 560) for regulating the layer thickness of the toner particles carried on the developing roller 510 is provided. The regulation blade 560 regulates the layer thickness when the flat surface of the regulation blade 560 contacts the developing roller 510. However, it is not limited to the above. For example, the regulation blade 560 may regulate the layer thickness by contacting the developing roller 510 with an edge.
When the regulation blade 560 comes into contact with the developing roller 510 at the edge and the layer thickness is regulated, the toner carried on the convex portion 519 is scraped off by the regulation blade 560. On the other hand, when the layer thickness is regulated by the flat surface of the regulating blade 560 coming into contact with the developing roller 510 as in the above embodiment, the regulating blade 560 causes the toner particles to be convex 519 ( Since the toner particles are pressed toward the top surface 519a), the toner particles are hardly scraped off by the regulating blade 560. When the regulating blade 560 presses the toner particles, a force is easily applied from the convex portion 519 to the toner particles carried on the convex portion 519. For this reason, in the above case, the effect of providing the convex portion 519 having the top surface 519a on the surface of the developing roller 510, that is, the effect of suppressing the deformation of the toner particles and the like is more effectively exhibited. Therefore, the above embodiment is more desirable.

  Further, in the above-described embodiment, as shown in FIG. 5, the surface has an inclination with respect to the axial direction and the circumferential direction of the developing roller 510, and has an equal pitch in the axial direction. It was assumed that a spiral groove portion (recessed portion 518) having a size of 112 μm) was provided. In addition, two types of recesses 518 are formed with different inclination angles (that is, the first recess 518a and the second recess 518b are formed). The convex portion 519 is provided so as to be surrounded by the two types of concave portions 518a and 518b. However, it is not limited to the above. For example, the convex portion 519 may be provided so as to be surrounded only by one type of concave portion (for example, the first concave portion 518a).

Furthermore, in the said embodiment, as shown in FIG. 8, the convex part 519 decided to be provided with the side surface 519b connected with the top surface 519a. Then, a roundness 519d is formed at the connecting portion 519c between the top surface 519a and the side surface 519b. However, it is not limited to the above. For example, as illustrated in FIG. 13, the connecting portion 519c may not be formed with a rounded shape 519d, and the connecting portion 519c may have a corner.
When the connecting portion 519c has a corner, when the toner particles come into contact with the corner, the force tends to concentrate on the local portion of the toner particle from the corner as an edge. On the other hand, when the rounded portion 519d is formed in the joint portion 519c, no edge is formed in the joint portion 519c, so that the force acting on the toner particles from the joint portion 519c can be reduced. For this reason, the above embodiment is more preferable in that the deformation of the toner particles can be suppressed.

  Here, the surface configuration of the developing roller 510 according to the modification shown in FIG. 13 will be described. FIG. 13 is a view showing a modified example of the developing roller 510 and is a schematic view showing a cross-sectional shape of the convex portion 519. The developing roller 510 shown in FIG. 13 has the same surface configuration as that of the developing roller 510 shown in FIG. 8 except that the connecting portion 519c is a corner (that is, the convex portion 519 and the concave portion 518 are formed). Have). Therefore, the developing roller 510 according to the modification also has a top surface 519a as shown in FIG. The width H of the top surface 519a is equal to or greater than the volume average particle diameter of the toner particles (specifically, the width H is about 36 μm).

Further, in the above embodiment, as shown in FIG. 8, the radius of curvature of the roundness 519d is set to be half or more of the volume average particle diameter of the toner particles, but is not limited thereto. For example, the radius of curvature of the roundness 519d may be smaller than half the volume average particle diameter of the toner particles.
When the radius of curvature of the roundness is smaller than half of the volume average particle diameter of the toner particles, when the toner particles come into contact with the roundness, the roundness bites into the toner particles, thereby concentrating the force from the roundness to the local portion of the toner particles. May act. On the other hand, when the radius of curvature of the roundness 519d is more than half of the volume average particle diameter of the toner particles as in the above embodiment, there is no possibility that the roundness 519d bites into the toner particles. It acts by dispersing force on the particles. For this reason, the above embodiment is more preferable in that the deformation of the toner particles can be suppressed.

Furthermore, in the above embodiment, as shown in FIG. 8, the inclination angle β of the side surface 519b provided on the convex portion 519 from the bottom surface 518c of the concave portion 518 is 45 degrees or less. However, it is not limited to the above. For example, the inclination angle β may be larger than 45 degrees.
When the inclination angle β of the side surface 519b is 45 degrees or less, the magnitude of the force component vertically upward of the force received from the side surface 519b when the toner particles contact the side surface 519b is in the horizontal direction. More than the magnitude of the force component. For this reason, in the above case, the toner particles can easily move up to the top surface 519a by climbing the side surface 519b due to the force component in the vertical direction, so that it is possible to suppress a decrease in the rolling property of the toner particles. Therefore, the above embodiment is more desirable.

Furthermore, in the above-described embodiment, the convex portion 519 and the concave portion 518 are both carrying portions for carrying toner particles, but are not limited thereto. For example, the concave portion 518 may be a carrying portion, while the convex portion 519 may not be a carrying portion.
However, when the convex portion 519 is a carrying portion, a force easily acts on the toner particles carried on the convex portion 519 that is the carrying portion from the convex portion 519. Therefore, the convex portion 519 is formed on the surface of the developing roller 510. The effect of the provision, that is, the effect of suppressing the deformation of the toner particles can be more effectively exhibited. Therefore, the above embodiment is more desirable.

Further, in the above embodiment, as shown in FIG. 8, the depth of the recess 518 is set to be twice or less the volume average particle diameter of the toner particles, but is not limited thereto. For example, the depth of the recess 518 may be greater than twice the volume average particle size of the toner particles.
When the depth of the recess 518 is less than or equal to twice the volume average particle diameter of the toner particles, most of the toner particles located between the developing roller 510 and the regulating blade 560 in the recess 518 Since it contacts at least one of the regulating blades 560, the chargeability of the toner particles becomes appropriate. In this respect, the above embodiment is more desirable. When the depth of the recess 518 is equal to or less than the volume average particle diameter (one time) of the toner particles, most of the toner particles positioned between the developing roller 510 and the regulating blade 560 in the recess 518 This is more desirable because it contacts both the developing roller 510 and the regulating blade 560.

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

  FIG. 14 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. 15 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.

  10 Printer, 20 Photoconductor, 30 Charging unit, 40 Exposure unit, 50 YMCK development unit, 50a Center axis, 51 Black development device, 52 Magenta development device, 53 Cyan development device, 54 Yellow development device, 55a, 55b, 55c, 55d Holding section, 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 cylindrical portion, 510b shaft portion, 512 uneven processing portion, 514 non-concave processing portion, 18 concave portion, 518a first concave portion, 518b second concave portion, 519 convex portion, 519a top surface, 519b side surface, 519c joint portion, 519d roundness, 520 upper seal, 520a short side end portion, 520b abutting surface, 520c opposite surface 524 Upper seal urging member, 530 toner container, 530a first toner container, 530b second toner container, 540 housing, 542 upper housing part, 544 lower housing part, 545 partition wall, 550 toner supply roller, 560 Regulating blade, 560a tip, 562 Rubber part, 562a Contact part, 564 Rubber support part, 564a Thin plate, 564b Thin plate support part, 564c Longitudinal ends, 564d Short end, 564e Short end, 572 Opening, 600 Pipe material, 602 Flange press-fitting part 604 flange, 650 round die, 650a convex, 652 round die, 652a convex, 700 image forming system, 702 computer, 704 display device, 706 printer, 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, T toner.

Claims (10)

A toner particle carrying roller for carrying toner particles charged with a layer thickness regulating member in contact with the toner particle carrying roller to develop a latent image formed on the image carrier,
The toner particle carrying roller has a plurality of convex portions surrounded by two kinds of groove portions intersecting each other on the surface,
The top surface of the convex portion is flat, and the width of the top surface is not less than the volume average particle diameter of the toner particles,
Furthermore, the convex portion includes a side surface connected to the top surface,
A connecting portion between the top surface and the side surface does not have an edge and has a roundness. (However, the toner particle carrying roller whose surface is blasted is excluded.) The toner particle carrying roller according to claim 1,
A toner particle carrying roller, wherein a radius of curvature of the roundness is not less than half of a volume average particle diameter of the toner particles. The toner particle carrying roller according to claim 1 or 2,
The toner particle carrying roller, wherein the groove is formed in a spiral shape with an inclination with respect to an axial direction and a circumferential direction of the toner particle carrying roller. The toner particle carrying roller according to any one of claims 1 to 3,
The toner particle carrying roller, wherein the groove portions are formed at an equal pitch in an axial direction of the toner particle carrying roller. A toner particle carrying roller according to any one of claims 1 to 4,
The toner particle carrying roller, wherein an angle formed by the bottom surface of the groove and the side surface on the surface is 135 degrees or more. A toner particle carrying roller according to any one of claims 1 to 5,
The depth of the groove is less than twice the volume average particle diameter of the toner particles.   A developing device comprising at least the toner particle carrying roller according to any one of claims 1 to 6.   An image forming apparatus comprising at least the developing device according to claim 7. The image forming apparatus according to claim 8, wherein
The latent image is formed having a dot-like latent image formed in a region partitioned in a lattice pattern,
2. An image forming apparatus according to claim 1, wherein a pitch of the region is formed larger than a pitch of the groove portion in the axial direction of the toner particle carrying roller.   An image forming system comprising at least a computer and the image forming apparatus according to claim 9 connected to the computer.

Images