JP4935076B2 - Development device - Google Patents

Description

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

  As a developing device for developing using toner particles, a developing device including a toner particle carrying roller for carrying a toner particle contained in a toner particle containing body and developing a latent image is known (for example, Patent Document 1). Irregularities are formed on the surface of the toner particle carrying roller in order to properly carry the toner particles.

Such a developing device has a toner particle supply roller for supplying toner particles contained in a toner particle container to a toner particle carrying roller. The toner particle supply roller is made of, for example, urethane foam having elasticity, and is pressed against the toner particle carrying roller in an elastically deformed state. The toner particle supply roller has a function of supplying the toner particles accommodated in the toner particle container to the toner particle carrying roller, and the toner particles remaining on the toner particle carrying roller after the development are transferred to the toner particle carrying roller. It also has a function to peel off from. That is, the toner particle supply roller mainly supports toner particles in the gaps, supplies the toner particles to the toner particle support rollers, and peels off the toner particles remaining on the toner particle support rollers at the wall portion between the gaps. ing.
JP 2003-263018 A

  In the developing device as described above, irregularities are formed on the surface of the toner particle carrying roller, and since the toner particle supply roller is foamed urethane or the like, a large number of voids are provided on the surface. For this reason, when supplying toner particles, the convex portion of the toner particle carrying roller and the wall portion between the gaps of the toner particle supply roller come into contact with each other, and the concave portion of the toner particle carrying roller and the gap between the toner particle supply rollers When the toner particles are in contact with the toner particles, the amount of the toner particles to be supported is different depending on the part of the toner particle supporting roller, and there is a problem that unevenness in density may occur in the developed toner image. It was.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a developing device capable of suppressing the occurrence of density unevenness in a developed toner image, and image formation having the developing device. An apparatus and an image forming system are realized.

The present invention mainly includes a rotatable toner particle carrying roller having a plurality of convex portions on a surface for carrying toner particles for developing a latent image, and the toner particles using a porous foam material. a toner particle supply roller rotatable to feed the carrying roller, between the opening of the hole, the average distance in the axial direction of the toner particles carrying roller is rather smaller than the maximum width in the axial direction of the top surface of the convex portion , The average distance in the circumferential direction of the toner particle carrying roller between the openings of the holes, the toner particle carrying roller rotating at the moving speed of the surface of the toner particle feeding roller when the toner particle feeding roller rotates said toner particles ratio moving velocity of the surface of the carrying roller, in divided by the time of, the having a, a toner particle supply roller has small than the maximum width in the circumferential direction of the top surface of the convex portion It is a developing apparatus according to claim.

  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 toner particle carrying roller having a plurality of convex portions on a surface for carrying toner particles for developing a latent image, and supplying the toner particles to the toner particle carrying roller with a porous foam material. And a toner particle supply roller having an average distance between the openings in the axial direction of the toner particle carrying roller smaller than a maximum width in the axial direction of the top surface of the convex portion.

  The toner particle supply roller has a function of supplying the toner particles contained in the toner particle container to the toner particle carrying roller, and peels off the toner particles remaining on the toner particle carrying roller after development from the toner particle carrying roller. It also has a function to take. For this reason, if the entire surface of the convex portion of the toner particle carrying roller is covered with a portion other than the hole of the toner particle supply roller of the porous foam material, the top surface of the covered convex portion is the remaining toner particles. As the toner particles are scraped off, it becomes difficult to supply new toner particles. If toner particles are not supplied to the top surface of the convex portion, the developed toner particle image may be lost or a portion having a low density may be generated.

  As described above, according to the developing device having the toner particle supply roller, the average distance in the axial direction of the toner particle carrying roller between the openings of the holes is smaller than the maximum width in the axial direction of the top surface of the convex portion. Even if the portion between the openings of the toner particle supply roller is in contact with the top surface of the toner particle, the top surface of the convex portion in the axial direction of the toner particle carrying roller may be completely covered with the portion between the openings of the hole. Can be avoided. For this reason, since the toner particles are appropriately supplied to the respective convex portions, it is possible to prevent the developed toner particle image from being lost or having a low density portion.

  In addition, a rotatable toner particle carrying roller having a plurality of convex portions on the surface for carrying toner particles for developing a latent image, and a porous foam material, the toner particles are put on the toner particle carrying roller. A rotatable toner particle supply roller for supplying, wherein an average distance in the circumferential direction of the toner particle carrying roller between the openings of the holes is determined by the surface of the toner particle supply roller when the toner particle supply roller rotates. A value obtained by dividing the moving speed by the ratio of the moving speed to the moving speed of the surface of the toner particle carrying roller when the toner particle carrying roller rotates is smaller than the maximum width in the circumferential direction of the top surface of the convex portion. And a particle supply roller.

  The toner particle supply roller has a function of supplying the toner particles contained in the toner particle container to the toner particle carrying roller, and peels off the toner particles remaining on the toner particle carrying roller after development from the toner particle carrying roller. It also has a function to take. For this reason, if the entire surface of the convex portion of the toner particle carrying roller is covered with a portion other than the hole of the toner particle supply roller of the porous foam material, the top surface of the covered convex portion is the remaining toner particles. As the toner particles are scraped off, it becomes difficult to supply new toner particles. If toner particles are not supplied to the top surface of the convex portion, the developed toner particle image may be lost or a portion having a low density may be generated.

  As described above, the average distance in the circumferential direction of the toner particle carrying roller between the openings of the holes is the toner particle of the moving speed of the surface of the toner particle supply roller when the toner particle supply roller rotates. A developing device having a toner particle supply roller having a value divided by a ratio to a moving speed of the surface of the toner particle carrying roller when the carrying roller rotates is smaller than the maximum width in the circumferential direction of the top surface of the convex portion. Accordingly, even if the portion between the openings of the toner particle supply roller is in contact with the top surface of the convex portion, the top surface of the convex portion is completely in the portion between the openings of the hole in the circumferential direction of the toner particle carrying roller. Covering can be avoided. For this reason, since the toner particles are appropriately supplied to the respective convex portions, it is possible to prevent the developed toner particle image from being lost or having a low density portion.

  In addition, a toner particle carrying roller having a plurality of convex portions on the surface for carrying toner particles for developing a latent image, and a porous foam material for supplying the toner particles to the toner particle carrying roller And a toner particle supply roller having a size such that at least a part of the top surface of the convex portion protrudes from a wall region surrounded by the plurality of holes when being in contact with the toner particle carrying roller. A developing device characterized by comprising:

  The toner particle supply roller has a function of supplying the toner particles contained in the toner particle container to the toner particle carrying roller, and peels off the toner particles remaining on the toner particle carrying roller after development from the toner particle carrying roller. It also has a function to take. For this reason, if the entire surface of the convex portion of the toner particle carrying roller is covered with a portion other than the hole of the toner particle supply roller of the porous foam material, the top surface of the covered convex portion is the remaining toner particles. As the toner particles are scraped off, it becomes difficult to supply new toner particles. If toner particles are not supplied to the top surface of the convex portion, the developed toner particle image may be lost or a portion having a low density may be generated.

  As described above, when contacting the toner particle carrying roller, at least a part of the top surface of the convex portion has a toner particle supply roller having a size that protrudes from the wall region surrounded by the plurality of holes. According to the developing device, even if the wall region surrounded by the plurality of holes of the toner particle supply roller is in contact with the top surface of the convex portion, the entire area of the top surface of the convex portion of the toner particle carrying roller is completely covered by the wall region. Covering can be avoided. For this reason, since the toner particles are appropriately supplied to the respective convex portions, it is possible to prevent the developed toner particle image from being lost or having a low density portion.

In such a developing device, it is desirable to have a layer thickness regulating member that abuts on the toner particle carrying roller and regulates the layer thickness of the toner particles supplied to the toner particle carrying roller.
According to such a developing device, the layer thickness of the toner particles supplied to the toner particle carrying roller is regulated by the layer thickness regulating member. For this reason, even if the toner is supplied to only a part of the top surface of the convex part, the toner particles supplied to the part are evenly spread on the top surface of the convex part by the layer thickness regulating member. As a result, it is possible to prevent the developed toner particle image from being missing or having a low density portion.

In such a developing device, it is preferable that the toner particles carried on the surface are pressed by a plane of the layer thickness regulating member to regulate the layer thickness.
According to such a developing device, the toner particles carried on the surface of the toner particle carrying roller are regulated on the surface of the toner particle carrying roller because the layer thickness is regulated by the plane of the layer thickness regulating member. The toner particles are not completely scraped off by the layer thickness regulating member, and the toner particles supplied only to a part of the top surface of the convex portion are spread evenly on the top surface of the convex portion by the layer thickness regulating member. Is possible. That is, it is possible to regulate the layer thickness of the toner particles in a state where the toner particles are carried on the groove portion of the toner particle carrying roller and on the peripheral surface other than the groove portion. Further, since the toner particles carried on the surface are pressed by the flat surface of the layer thickness regulating member, any one of the surface of the toner particle carrying roller, the layer thickness regulating member, and the toner particles and the toner particles are mutually connected. It is possible to charge well by rubbing.

In such a developing device, the plurality of convex portions may be formed on the surface of the toner particle carrying roller by forming two types of spiral groove portions having different inclination angles with respect to the axial direction and the circumferential direction. desirable.
According to such a developing device, since the toner particle carrying roller is formed with two types of groove portions having different inclination angles, the toner particles are moved in two types along the groove portion. . For this reason, it is possible to prevent the toner particles from moving and being biased in only one predetermined direction.

In such a developing device, it is desirable that the two types of the groove portions intersect each other to form a lattice shape.
According to such a developing device, since the two types of groove portions intersect, the toner particles that have started to roll along one groove portion may roll along the other groove portion from the middle. Is possible. For this reason, it is possible to more effectively suppress the deviation of the moving direction of the toner particles.

In such a developing device, it is preferable that the top surface of the convex portion surrounded by the two types of grooves is a rhombus.
According to such a developing device, since the top surface is rhombus, the toner particles rolling in the two types of grooves reach the position intersecting with the other groove when each rolls by substantially the same distance. For this reason, it is possible to cause the toner particles that have rolled along any of the grooves to roll in substantially the same manner and be charged in substantially the same manner.

In such a developing device, it is preferable that the two types of the groove portions are formed so that one of two diagonal lines of each rhombus is along the circumferential direction.
According to such a developing device, since the groove is formed so that one of the two diagonal lines of each rhombus is along the circumferential direction, from one apex angle of the diagonal line along the circumferential direction, The two types of grooves are formed with inclinations of the same angle in opposite directions in the axial direction. For this reason, the toner particles that are moved along the two types of grooves are moved substantially in the same manner toward both ends in the axial direction. Therefore, it is possible to move the toner particles without unevenness.

In such a developing device, it is desirable that the convex portion has a longer diagonal line along the circumferential direction of the two diagonal lines.
According to such a developing device, in the convex portion having a rhombic top surface, two apex angles positioned along the circumferential direction are acute angles, and two apex angles positioned along the axial direction are obtuse angles. For this reason, the toner particles can be configured to move more easily in the circumferential direction.

In such a developing device, it is desirable that the top surface of the convex portion surrounded by the two types of grooves is a square.
According to such a developing device, since the top surface of the convex portion surrounded by the two types of grooves is a square, the convex portion is positioned along two apex angles positioned along the circumferential direction and along the axial direction. The two apex angles are both right angles, and the two types of grooves have the same inclination with respect to the circumferential direction. For this reason, the toner particles can be easily moved in the circumferential direction and the axial direction as well. For this reason, it is possible to uniformly charge the toner particles by rolling them more uniformly.

In the developing device, it is preferable that the convex portion has a surface for supporting the toner particles.
According to such a developing device, since the convex portion has a surface for carrying toner particles, the toner particle carrying roller carries toner particles in both the groove portion and the convex portion. Therefore, by making the surface of the toner particle carrying roller face the image carrier, it is possible to develop the latent image while suppressing density unevenness in the entire portion of the image carrier facing the surface of the toner particle carrying roller. It is.

In such a developing device, it is desirable that the depth of the groove is not more than twice the volume average particle diameter of the toner particles.
According to such a developing device, since the depth of the groove is not more than twice the volume average particle diameter of the toner particles, it is appropriate that two or more toner particles entering the groove overlap in the depth direction in the groove. Can be avoided. For this reason, it is possible to charge the toner particles in the groove portion satisfactorily by rolling them uniformly.

In addition, a toner particle carrying roller having a plurality of convex portions on the surface for carrying toner particles for developing a latent image, and a porous foam material for supplying the toner particles to the toner particle carrying roller And a toner particle supply roller having a size such that at least a part of the top surface of the convex portion protrudes from a wall region surrounded by the plurality of holes when being in contact with the toner particle carrying roller; A layer thickness regulating member that is in contact with the toner particle carrying roller and regulates the layer thickness of the toner particles supplied to the toner particle carrying roller, and the toner particles carried on the surface are The layer thickness is regulated by the flat surface of the layer thickness regulating member to regulate the layer thickness, and two types of spiral grooves having different inclination angles with respect to the axial direction and the circumferential direction are formed on the surface of the toner particle carrying roller. The plurality of convex portions are formed, the two types of groove portions intersect with each other to form a lattice shape, and the top surface of the convex portion surrounded by the two types of groove portions is a rhombus, The two types of the groove portions are formed so that one of the two diagonal lines of each of the rhombuses is along the circumferential direction, and the convex portion has a longer diagonal line in the circumferential direction of the two diagonal lines. The top surface of the convex portion surrounded by the two types of the groove portions is square, the convex portion has a surface for carrying the toner particles, and the depth of the groove portion is determined by the depth of the toner. The developing device is characterized in that the volume average particle diameter of the particles is twice or less.
According to such a developing apparatus, the object of the present invention can be achieved most effectively because most of the effects described above can be achieved.

  A toner particle carrying roller having a plurality of convex portions on a surface for carrying toner particles for developing a latent image; and supplying the toner particles to the toner particle carrying roller with a porous foam material; Forming an image using a developing device having a toner particle supply roller having an average distance in the axial direction of the toner particle carrying roller between openings of the holes smaller than a maximum width in the axial direction of the top surface of the convex portion; An image forming apparatus characterized by the above can also be realized.

  Also, a computer, a toner particle carrying roller having a plurality of convex portions on the surface for carrying toner particles for developing a latent image, and the toner particle carrying roller using a porous foam material And a toner particle supply roller having an average distance in the axial direction of the toner particle carrying roller between the openings of the holes smaller than the maximum width in the axial direction of the top surface of the convex portion. It is also possible to realize an image forming system characterized by having an image forming apparatus that forms the image.

=== Overview of Image Forming Apparatus ===
A configuration example of a laser beam printer (hereinafter also referred to as a printer) 10 as an example of an image forming apparatus that forms an image using a developing device as a developing apparatus according to the present embodiment, with reference to FIGS. An operation example will be described. FIG. 1 is a diagram showing main components constituting the printer 10, and FIG. 2 is a diagram for explaining a configuration of a control unit provided in 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 of Printer 10>
As shown in FIG. 1, the printer 10 includes a charging unit 30, an exposure unit 40, a developing device holding unit 50, and a primary transfer unit along the rotation direction of a photoconductor 20 as an example of an image carrier that carries a latent image. 60, an intermediate transfer body 70, and a cleaning unit 75, and further controls a secondary transfer unit 80, a fixing unit 90, a display unit 95 formed of a liquid crystal panel as a means for notifying a user, and these units. It has a control unit 100 that 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.

  The developing device holding unit 50 converts the latent image formed on the photoreceptor 20 into toner particles (hereinafter also referred to as toner) T accommodated in developing devices 51, 52, 53, and 54 as an example of a developing device, that is, The black (K) toner contained in the black developing device 51, the magenta (M) toner contained in the magenta developing device 52, the cyan (C) toner contained in the cyan developing device 53, and the yellow developing device 54. This is an apparatus for developing using yellow (Y) toner.

  In the present embodiment, the developing device holding unit 50 is capable of moving the positions of the four developing devices 51, 52, 53, and 54 by rotating. That is, the developing device holding unit 50 holds the four developing devices 51, 52, 53, and 54 by the four attaching / detaching portions 50a, 50b, 50c, and 50d, and the four developing devices 51, 52, and 53 are provided. , 54 can rotate around the central axis 50e while maintaining their relative positions. Each time the photosensitive member 20 rotates once, one of the four developing devices 51, 52, 53, 54 is selectively opposed to the photosensitive member 20, and the opposed developing devices 51, 52, 53, 54, The latent images formed on the photoreceptor 20 are sequentially developed with the toner contained in the toner 54. 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. The intermediate transfer member 70 is an endless belt, and is driven to rotate at substantially the same peripheral speed as the photosensitive member 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 recording 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 recording medium onto a recording medium such as paper 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 is input to the main controller 101, and the unit controller 102 responds to an instruction based on the image signal. The unit is controlled to form an image.

  The main controller 101 is connected to a host computer via an interface 112, and includes an image memory 113 for storing an image signal input from the host computer, a CPU 111 for controlling the entire printer 10, and the like.

  The unit controller 102 includes a CPU 120, a memory 116 such as a RAM and a ROM, and units of the apparatus main body (charging unit 30, exposure unit 40, primary transfer unit 60, cleaning unit 75, secondary transfer unit 80, fixing unit 90, The display unit 95) and each drive control circuit for driving and controlling the developing device holding unit 50 are controlled, and each unit is controlled based on a signal input from the main controller 101.

<Operation of Printer 10>
Next, the operation of the printer 10 will be described with reference to other components.
First, when an image signal from a host computer (not shown) is input to the main controller 101 of the printer 10 via the interface (I / F) 112, the photosensitive device is controlled by the unit controller 102 based on a command from the main controller 101. The developing roller 510 and the intermediate transfer member 70 provided on the body 20, the developing devices 51, 52, 53, and 54 rotate. The photoconductor 20 is charged by the charging unit 30 at the charging position while rotating.

The charged region of the photoconductor 20 reaches the 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 by the exposure unit 40. At this time, the developing device holding unit 50 positions the yellow developing device 54 containing yellow (Y) toner 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 is applied to the primary transfer unit 60. During this time, the secondary transfer unit 80 is separated from the intermediate transfer member 70.

By repeating the above processing for the second color, the third color, and the fourth color, the four color toner images corresponding to the respective image signals are transferred onto the intermediate transfer body 70 in an overlapping manner. . 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 a recording sheet as a recording medium by the secondary transfer unit 80. The recording paper 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 recording paper is heated and pressurized by the fixing unit 90 and fused to the recording paper. On the other hand, after the primary transfer position has elapsed, the toner remaining on the surface of the photoreceptor 20 is scraped off by the cleaning blade 76 to prepare for charging for forming the next latent image. The toner scraped off is collected in a waste toner container.

=== Overview of Developer ===
Next, a configuration example of the developing device will be described with reference to FIGS. FIG. 3 is a perspective view of the yellow developing device. FIG. 4 is a cross-sectional view showing the main components of the yellow developing device. FIG. 5 is a perspective view showing the developing device with the developing roller removed. FIG. 6 is an enlarged view of a cross section of the roller portion 550a of the toner supply roller 550, and is a schematic diagram showing a hole 550c and a wall region 550d provided in the roller portion 550a. The cross-sectional view shown in FIG. 4 is a view showing a cross section obtained by cutting the yellow 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 developing device holding 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 yellow. (Y) Although the yellow developing unit 54 containing toner is provided, the configuration of each developing unit is the same, so the yellow developing unit 54 will be described below.

<Configuration of Yellow Developer 54>
The yellow developing device 54 is a housing 540 that contains toner T, a developing roller 510 as an example of a toner particle carrying roller for carrying toner, and an example of a toner particle supply roller for supplying toner to the developing roller 510. The toner supply roller 550 and the regulating blade 560 as an example of the layer thickness regulating member for regulating the layer thickness of the toner carried on the developing roller 510, and the upper gap between the housing 540 and the developing roller 510 are sealed. An upper seal 520, an end seal 527 for sealing a gap on the end side between the housing 540 and the developing roller 510 are provided.

  The housing 540 is manufactured by welding an upper housing portion 542 and a lower housing portion 544 which are integrally molded, and a toner as a toner particle container for containing the toner T therein. A housing portion 530 is formed. The toner storage portion 530 is divided into two toner storage portions, that is, a first toner storage portion 530a and a second toner, by a partition wall 545 for partitioning the toner T that protrudes inward from the inner wall (in the vertical direction in FIG. 4). 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. In the state shown in FIG. 4, the movement of the toner T is restricted by the partition wall 545. However, when the developing device holding unit 50 rotates, the toner stored in the first toner storage portion 530a and the second toner storage portion 530b is temporarily moved to the upper communicating side of the developing position. When the toner is collected and returns to the state shown in FIG. 4, the toners are mixed and returned to the first toner storage portion 530a and the second toner storage portion 530b. That is, the toner T in the developing device is agitated by the rotation of the developing device holding unit 50. For this reason, in this embodiment, the stirring member is not provided in the toner storage portion 530, but a stirring member for stirring the toner T stored in the toner storage portion 530 may be provided. As shown in FIG. 4, the housing 540 has an opening 572 in the lower portion, and a developing roller 510 described later is provided so as to face the opening 572.

  The toner supply roller 550 includes a roller portion 550a formed of a porous foam material having elasticity, for example, urethane foam, and a shaft body 550b serving as a rotation center of the roller portion 550a. The toner supply roller 550 is supported by the housing 540 at both ends of the shaft body 550b, so that the toner supply roller 550 is rotatably supported around the shaft body 550b. The roller portion 550a is accommodated in the above-described first toner accommodating portion 530a (inside the housing 540) of the housing 540, and the toner T accommodated in the first toner accommodating portion 530a is passed through the hole 550c (in FIG. 6, hatched lines). The toner contained in the hole 550c is mainly supplied to the developing roller 510. The toner supply roller 550 is provided vertically below the first toner storage portion 530a. The toner T accommodated in the first toner accommodating portion 530a is supplied to the developing roller 510 by the toner supply roller 550 below the first toner accommodating portion 530a. Further, the toner supply roller 550 peels off the excess toner T remaining on the developing roller 510 after development from the developing roller 510. At this time, the wall region 550d (the hatched portion in FIG. 6) surrounded by the plurality of holes 550c formed in the toner supply roller 550 comes into contact with the developing roller 510, thereby causing the developing roller 510 to The remaining toner is stripped off. That is, the toner remaining on the developing roller 510 is mainly peeled off by the wall region 550d of the toner supply roller 550.

  The toner supply roller 550 and the developing roller 510 are assembled to the housing 540 while being pressed against each other. Therefore, the roller portion 550a of the toner supply roller 550 is in contact with the developing roller 510 in an elastically deformed state. Further, the shaft body 550b is below the rotation center axis of the developing roller 510. 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). In this embodiment, a peripheral speed difference is provided between the toner supply roller 550 and the developing roller 510, and the moving speed of the surface of the toner supply roller 550 when the toner supply roller 550 rotates is as follows. This is about 1.5 times the moving speed of the surface of the developing roller 510 when the developing roller 510 rotates.

  The developing roller 510 carries the toner T and conveys it to a developing position facing the photoconductor 20. The developing roller 510 is made of metal and is made of an aluminum alloy such as 5056 aluminum alloy or 6063 aluminum alloy, or an iron alloy such as STKM, and is subjected to nickel plating, chrome plating, or the like as necessary. May be. On the surface of the developing roller 510, a spiral groove is provided at the center in the axial direction of the developing roller 510. 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, and is rotatable about the central axis. As shown in FIG. 4, the developing roller 510 rotates in a direction (counterclockwise in FIG. 4) opposite to the rotation direction of the photoconductor 20 (clockwise in FIG. 4). The central axis is below the central axis of the photoconductor 20.

  As shown in FIG. 4, there is a gap between the developing roller 510 and the photoconductor 20 in a state where the yellow developing device 54 faces the photoconductor 20. That is, the yellow developing device 54 develops the latent image formed on the photoconductor 20 in a non-contact state. 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 regulating blade 560 applies a charge to the toner T carried on the developing roller 510 and regulates the layer thickness of the toner T carried on the developing roller 510. The regulation blade 560 has a rubber part 560a and a rubber support part 560b. The rubber part 560a is made of silicon rubber, urethane rubber or the like, and the rubber support part 560b is a thin plate having spring properties such as phosphor bronze or stainless steel. The rubber part 560a is supported on the short side of the rubber support part 560b along the longitudinal direction of the rubber support part 560b, and the other end side of the rubber support part 560b is supported by the blade support metal plate 562. In this state, it is attached to the housing 540 via the blade support sheet metal 562. Further, a blade back member 570 made of malt plane or the like is provided on the side opposite to the developing roller 510 side of the regulating blade 560.

  Here, the rubber portion 560 a is pressed from the central portion of the developing roller 510 to both ends by the elastic force due to the bending of the rubber support portion 560 b. Further, the blade back member 570 prevents the toner T from entering between the rubber support portion 560b and the housing 540, stabilizes the elastic force due to the bending of the rubber support portion 560b, and provides rubber from the back of the rubber portion 560a. The rubber portion 560 a is pressed against the developing roller 510 by urging the portion 560 a toward the developing roller 510. Therefore, the blade back member 570 improves the uniform contact property of the rubber portion 560a to the developing roller 510.

  The end of the regulating blade 560 opposite to the side supported by the blade support metal plate 562, that is, the tip is not in contact with the developing roller 510, and a portion away from the tip by a predetermined distance is the developing roller. 510 is in contact 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 on the flat surface of the rubber portion 560a. The regulating blade 560 is disposed so that the tip thereof faces the upstream side in the rotation direction of the developing roller 510, and is in a so-called counter contact. The contact position where the regulating blade 560 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.

  The rubber support portion 560b is longer than the rubber portion 560a in the axial direction of the developing roller 510, and extends outward from both ends of the rubber portion 560a. An end seal 527 made of, for example, a nonwoven fabric having a thickness thicker than that of the rubber portion 560a is attached to the same surface as the rubber portion and 560a at the extended portion of the rubber support portion 560b. At this time, the end surface of the rubber portion 560 a in the axial direction is in contact with the side surface of the end seal 527.

  The end seal 527 is provided so as to come into contact with both end portions 510b on the surface of the developing roller 510 where the groove portion 511 is not provided when the developing roller 510 is attached, and has a width extending outward from the end portion of the developing roller 510. have. Further, the end seal 527 extends sufficiently longer than the tip of the rubber portion 560 a of the regulating blade 560. When the regulating blade 560 is attached to the housing 540, the end seal 527 is placed along a portion of the housing 540 formed so as to face the outer peripheral surface of the developing roller 510, and closes the gap between the housing 540 and the developing roller 510. .

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

<Operation of Yellow Developer 54>
In the yellow developing device 54 configured as described above, the toner supply roller 550 supplies the toner T accommodated in the toner accommodating portion 530 to the developing roller 510. The toner T supplied to the developing roller 510 reaches the abutting position of the regulating blade 560 as the developing roller 510 rotates, and when the toner T passes through the corresponding contacting position, an electric charge is applied and the layer thickness is regulated. Is done.

  The charged toner T on the developing roller 510 reaches a developing position facing the photoconductor 20 by further rotation of the developing roller 510, and a latent image formed on the photoconductor 20 under an alternating electric field at the developing position. For development. The toner T on the developing roller 510 that has passed the developing position by further rotation of the developing roller 510 passes through the 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.

=== Surface shape of developing roller ===
FIG. 7 is a conceptual diagram for explaining the surface shape of the developing roller. FIG. 8 is a cross-sectional view for explaining a cross section when the developing roller is cut along a plane passing through an axis. In FIG. 7, the groove 511 on the surface of the developing roller 510 is shown as a straight line for convenience, but since the groove 511 is formed in a spiral shape, it is formed so that it looks exactly like a curve.

  The developing roller 510 is provided with a groove in the central portion 510a in the axial direction, thereby forming an uneven portion for supporting toner particles, and a smooth peripheral surface so that the end seal 527 is in close contact with both ends 510b. It has.

  As shown in FIG. 7, in the central portion 510a of the developing roller 510 in the present embodiment, 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. 511 is formed. In the present embodiment, the groove portion 511 is formed in two types with different inclination angles with respect to the axial direction and the circumferential direction of the developing roller 510. The two types of groove portions 511 intersect with each other to form a lattice shape, and the top surface 512a of the convex portion 512 surrounded by the two types of groove portions 511 is formed in a substantially square shape. Further, the two types of the groove portions 511 are formed so that one of the two diagonal lines of the square of the top surface 512a of the convex portion 512 is along the circumferential direction.

  That is, one of the two types of grooves 511 is formed in a spiral shape so as to form an angle of 45 ° clockwise with the axis of the developing roller 510, and the other is counterclockwise with the axis of the developing roller 510. It is formed in a spiral shape so as to form an angle of 45 ° in the direction. For this reason, the angle at which one groove 511a and the other groove 511b intersect is 90 °. In addition, since the pitch in the axial direction of the developing roller 510 of the one groove portion 511a and the other groove portion 511b is equal, the shape of the top surface 512a of the convex portion 512 surrounded by the two types of groove portions is substantially square. It becomes.

  As shown in FIG. 8, the two types of groove portions 511 are each formed at an interval of 80 μm in the axial direction of the developing roller 510, and an inclined portion 511 d extending from the top surface 512 a of the convex portion 512 to the bottom surface 511 c of the groove portion 511. Is formed such that the intersecting angle α of the virtual plane obtained by extending the two inclined surfaces forming the groove 511 in the direction of the axis C is 90 °.

Further, the depth of the groove portion 511, that is, the distance from the top surface 512a of the convex portion 512 to the bottom surface 511c of the groove portion 511 is formed to be constant at about 7 μm. Here, the volume average particle diameter of the toner is about 5 to 10 μm, and the depth of the groove 511 is set to be not more than twice the volume average particle diameter of the toner. For this reason, it is appropriately avoided that two or more toner particles entering the groove portion 511 overlap in the depth direction in the groove portion 511, and the toner particles in the groove portion 511 are rolled uniformly and charged well. FIG. 9 is a diagram for explaining a state in which the regulating blade is in contact with the developing roller carrying toner particles.

  In particular, the groove 511 of the developing roller 510 according to the present embodiment has a depth of 7 μm, which is almost 1 time as compared with the volume average particle diameter of the toner particles T. For this reason, since the regulating blade 560 is made of rubber and follows the unevenness of the surface 510 d of the developing roller 510, the toner layer having a thickness corresponding to one toner particle on the entire surface of the developing roller 510 without overlapping the toner particles T. Can be formed. By forming a toner layer having a single particle thickness on the surface 510d of the developing roller 510 in this manner, each toner particle T can be reliably charged in the entire region including the convex portion 512 and the groove portion 511 of the central portion 510a. It is possible to reliably carry the toner on the developing roller 510 to improve transferability during development and to prevent toner from leaking outside the developing device.

  That is, if unevenness having a non-uniform size, depth, shape, or the like is formed on the surface 510d of the developing roller 510, the toner particles that enter the deep recesses of the carried toner particles are difficult to roll and are not easily charged. . In addition, when grooves along the circumferential direction are formed at predetermined intervals in the axial direction, the position in the axial direction of the photoconductor 20 facing the groove does not change even when the photoconductor 20 rotates. In the developed toner image, there is a tendency that only the portion facing the groove portion has a high density. On the other hand, when the groove portion is formed along the axial direction, the rotation direction of the toner particle carrying roller and the direction of the groove portion are almost orthogonal to each other, so that the carried toner particles are difficult to roll and are not easily charged.

  Since the developing roller 510 of this embodiment has two types of grooves 511a and 511b with different inclination angles, the toner particles are moved in two types along the grooves 511a and 511b. Become. For this reason, it is possible to prevent the toner particles from moving and being biased in only one predetermined direction. Furthermore, since the two types of grooves 511a and 511b intersect, the toner particles that have started to roll along one of the grooves 511a (511b) are transferred along the other groove 511b (511a) from the middle. It is possible to move. For this reason, it is possible to more effectively suppress the deviation of the moving direction of the toner particles.

  In addition, since the top surface of the convex portion surrounded by the two types of grooves is square, the convex portion has two vertical angles positioned along the circumferential direction and two vertical angles positioned along the axial direction. Both become right angles, and the two types of grooves 511a and 511b have the same angle of inclination with respect to the circumferential direction. For this reason, the toner particles can be easily moved in the circumferential direction and the axial direction as well. Therefore, it is possible to uniformly charge the toner particles by rolling them more uniformly. Furthermore, since the groove part 511 is formed so that one of the two diagonal lines which each square has follows along the circumferential direction, from one apex angle of the diagonal line along the circumferential direction, two kinds of groove parts 511a, 511b is formed with an inclination of the same angle in opposite directions in the axial direction. For this reason, the toner particles moved along the two types of groove portions 511a and 511b are moved substantially in the same manner toward both ends in the axial direction. Therefore, it is possible to move the toner particles without unevenness.

Such a developing roller 510 is formed by rolling. FIG. 10 is a diagram for explaining how the developing roller 510 is formed by rolling. FIG. 11 is a diagram illustrating a procedure for forming the developing roller.
The developing roller 510 is formed from a cylindrical hollow material.

  The cylindrical material is first cut to a length that can form a central portion 510a for carrying toner as the developing roller 510 and an end portion 510b with which the end seal 527 abuts, and the cylindrical member 515 is cut out. (S001). In the cylindrical member 515, a step portion 510c (FIG. 7) for fitting the flange 513 having the shaft of the developing roller 510 is formed in the inner peripheral portion of both end portions by cutting (S002). Here, the flange 513 includes a disk-shaped flange main body 513a having a diameter that is press-fitted into the formed stepped portion 510c, and a shaft portion 513b that protrudes perpendicularly to the disk surface from the center thereof. ing.

  Next, the flange 513 having the shaft portion 513b is fitted into the cylindrical member 515 having the step portion 510c formed inside the both end portions so that the shaft portion 513b protrudes outward of the cylindrical member (S003). .

  Thereafter, the cylindrical member 515 in which the flange 513 is fitted is supported by the shaft portions 513b at both ends and rotated around the shaft, and the outer peripheral surface of the cylindrical member 515 is slightly cut over the entire circumference, thereby The surface of the cylindrical member 515 is polished so that the entire region is concentric with the shaft, that is, at a certain distance from the shaft, so that the non-rolled developing roller 509 is formed (S004).

  The cylindrical member 515 whose surface has been polished is rolled by an apparatus equipped with a die 900 as two types of processing tools as shown in FIG. 10, and two types of grooves 511a and 511b are formed on the surface (S005). ). The rolling device arranges the workpiece (here, the non-rolled processing developing roller 509) while the two types of dies 900 arranged at opposite positions are rotating in the same direction, and the two types of dies 900 are arranged. The unrolled developing roller 509 is pressed, and the unrolled developing roller 509 is conveyed in the axial direction while rotating in the direction opposite to the die 900.

  The die 900 is provided with blades 900a for forming the above-described grooves 511a and 511b. The blades 900a are formed on the surface of the non-roll processed developing roller 509 with the blades. An inclination is provided so that the grooves 511a and 511b are orthogonal. Here, the part where the die 900 is brought into contact with the surface of the non-rolling processing developing roller 509 is the blade 900a. However, the rolling process does not actively cut the work, but the work is crushed by the pressing force. Acts to form a depression.

  Further, during this rolling, the non-rolled developing roller 509 is not contacted with the die 900 at both ends 510b, leaving a smooth surface without unevenness at both ends 510b. deep. That is, the top surface 512a of the convex portion 512 where the die 900 is not in contact with the central portion 510a of the developing roller 510 and the both ends 510b not to be processed by rolling are distance L from the axis C (FIG. 8). ) Is kept at a constant distance from the axis C. The surface 510d of the developing roller 510 is substantially covered with the bottom surfaces 511c of the grooves 511a and 511b that are recessed by the contact of the die 900 and the non-processed surface that the die 900 does not contact.

  The developing roller 510 formed by rolling may be subjected to, for example, electroless Ni—P plating, electroplating, or hard chrome plating, if necessary.

=== Relationship between convex portion of developing roller and wall region of toner supply roller ===
As described above, the developing roller 510 is supplied with toner from the toner supply roller 550, and the toner remaining after developing the latent image on the photoreceptor 20 is peeled off by the toner supply roller 550. At this time, the toner accommodated in the hole 550c of the toner supply roller 550 is mainly supplied to the surface of the developing roller 510 and remains on the surface of the developing roller 510 in contact with the wall region 550d surrounded by the plurality of holes 550c. The toner that is being removed will be peeled off. By the way, on the surface of the developing roller 510, a large number of the above-described substantially square-shaped convex portions 512 are formed. Since the latent image on the photoconductor 20 is developed by the toner carried on the opposite portion of the developing roller 510, it is necessary that both the groove portion 511 and the convex portion 512 of the developing roller 510 carry the toner.

  However, the developing roller 510 according to the present embodiment is formed so that the position of the surface of each convex portion 512, that is, the distance from the axis of the developing roller 510 to the surface thereof is substantially equal. Therefore, when the developing roller 510 and the toner supply roller 550 come into contact with each other, if the entire area of the surface of the convex portion 512 of the developing roller 510 is covered with the wall region 550d of the toner supply roller 550, the entire area of the surface is covered. As for the covered convex part 512, the toner of the surface will be stripped off. Therefore, if the entire surface of the convex portion 512 of the developing roller 510 is covered with the wall region 550d of the toner supply roller 550, a portion where toner is not carried on the surface of the developing roller 510 occurs, and a latent image is formed. When developing, there is a possibility that a portion not developed in the toner image may be generated or a portion having a low density may be generated, resulting in density unevenness.

  Therefore, in the developing device according to the present embodiment, the average distance in the axial direction of the toner supply roller 550 between the openings of the hole 550c of the toner supply roller 550 is equal to the top surface 512a of the convex portion 512 of the development roller 510. It is smaller than the maximum width in the axial direction. This matter will be described with reference to FIG. FIG. 12 is a schematic diagram for explaining the effectiveness of the developing device according to the present embodiment.

  The left diagram of FIG. 12 shows a schematic diagram in which the cross section of the roller portion 550a of the toner supply roller 550 is enlarged as in FIG. Here, the distance in the axial direction of the toner supply roller 550 between the openings of the hole 550c of the toner supply roller 550 is, for example, a distance indicated by symbols Dx1, Dx2, Dx3, and Dx4 in FIG. The average distance Dxave of the distances is an average value of a plurality (for example, 20) of the distances Dx1, Dx2,. In the toner supply roller 550 according to this embodiment, the average distance Dxave is about 40 to 50 μm.

  On the other hand, one of the top surfaces 512a of the convex portions 512 shown in FIG. 7 is shown in the right view of FIG. In developing roller 510 according to the present embodiment, the maximum width in the axial direction on top surface 512a of convex portion 512 (the maximum width is indicated by symbol Wx in FIG. 12) is about 80 μm.

  As described above, in the developing device according to the present embodiment, the average distance Dxave is smaller than the maximum width Wx. That is, in the developing device, even if the wall region 550d between the openings of the hole 550c of the toner supply roller 550 is in contact with the top surface 512a of the convex portion 512, the top surface 512a is in the axial direction of the toner supply roller 550. It can be avoided that the wall region 550d is completely covered (an example of a portion on the top surface 512a that is not covered by the wall region 550d is represented by hatching in the right diagram of FIG. 12). Therefore, the portion where the toner supply roller 550 is in contact with the developing roller 510 is separated from the toner supply roller 550, and when the carried toner is regulated in charge and layer thickness by the regulation blade 560, the convex portion The toner is appropriately carried on the top surface 512a of 512.

  Even if the toner is carried on a part of the top surface 512a of the convex portion 512, the layer thickness is regulated by the regulation blade 560, so that the toner swelled and carried on the top surface 512a of the convex portion 512 is retained. It will be leveled to the top surface 512a. In other words, the toner swelled and carried on the top surface 512a is spread over a wide area of the top surface 512a. Therefore, when the latent image is developed, it is possible to appropriately avoid occurrence of a non-developed portion in the toner image or occurrence of a density unevenness due to occurrence of a low-density portion.

  Next, the relationship between the top surface 512a of the convex portion 512 and the wall region 550d in the circumferential direction of the developing roller 510 and the toner supply roller 550 will be considered with reference to FIG. FIG. 13 is a schematic diagram for explaining the effectiveness of the developing device according to the present embodiment.

  The left diagram of FIG. 13 shows a schematic diagram in which the cross section of the roller portion 550a of the toner supply roller 550 is enlarged as in FIG. Here, the distance in the circumferential direction of the toner supply roller 550 between the openings of the hole 550c of the toner supply roller 550 is, for example, a distance indicated by symbols Dy1, Dy2, and Dy3 in FIG. The average distance Dyave of the distances is an average value of a plurality (for example, 20) of the distances Dy1, Dy2, ..., Dy20. In the toner supply roller 550 according to the present exemplary embodiment, the average distance Dyave is about 40 to 50 μm, like the above-described average distance Dxave.

  On the other hand, the right view of FIG. 13 shows one of the top surfaces 512a of the convex portions 512 shown in FIG. In the developing roller 510 according to the present embodiment, the maximum circumferential width (the maximum width is indicated by the symbol Wy in FIG. 13) on the top surface 512a of the convex portion 512 is the same as the maximum width Wx described above. About 80 μm.

  Also in the circumferential direction, even if the average distance Dyave and the maximum width Wy are such that the wall region 550d between the openings of the holes 550c of the toner supply roller 550 is in contact with the top surface 512a of the convex portion 512, the toner supply roller 550. If the relationship that can be avoided that the top surface 512a is completely covered by the wall region 550d in the circumferential direction is satisfied, the toner image is developed when the latent image is developed. There is an effect of appropriately avoiding occurrence of a non-applied part or occurrence of a density unevenness due to the occurrence of a part having a low density.

  Here, considering this relationship, the circumferential direction is slightly different from the axial direction described above. That is, in this embodiment, as described above, there is a circumferential speed difference between the toner supply roller 550 and the developing roller 510, and the surface of the toner supply roller 550 when the toner supply roller 550 rotates. Is about 1.5 times the moving speed of the surface of the developing roller 510 when the developing roller 510 rotates. In this case, for example, while the surface of the toner supply roller 550 advances by the average distance Dave, for example, the surface of the developing roller 510 develops the average distance Dave by the moving speed of the surface of the toner supply roller 550. Only the distance divided by the ratio R (ie, 1.5) to the moving speed of the surface of the roller 510 will advance. Therefore, in the circumferential direction, a value obtained by dividing the average distance Dave by the ratio R (that is, 1.5) of the moving speed of the surface of the toner supply roller 550 to the moving speed of the surface of the developing roller 510 is The effect described above is exhibited when the width is smaller than the maximum circumferential width Wy of the top surface 512a of the convex portion 512 of the developing roller 510.

  In this embodiment, the value obtained by dividing the average distance Dave by the ratio R (ie, 1.5) of the moving speed of the surface of the toner supply roller 550 to the moving speed of the surface of the developing roller 510 is: The value is about 26 to 33 μm, which is smaller than the maximum width Wy (about 80 μm). Therefore, even if the wall region 550d between the openings of the holes 550c of the toner supply roller 550 is in contact with the top surface 512a of the convex portion 512, the top surface 512a is completely in the wall region 550d in the circumferential direction of the toner supply roller 550. It is possible to avoid being covered (an example of a portion on the top surface 512a that is not covered by the wall region 550d is represented by hatching in the right diagram of FIG. 13). Therefore, when the latent image is developed, it is possible to appropriately avoid the occurrence of a non-developed part in the toner image or the occurrence of a density unevenness due to the occurrence of a low density part.

  Further, as shown in FIG. 14, the developing device according to the present embodiment has at least the top of the convex portion 512 when the convex portion 512 of the developing roller 510 and the wall region 550d of the toner supply roller 550 come into contact with each other. Part of the surface 512a is formed so as to protrude from the wall region 550d surrounded by the plurality of holes 550c (in FIG. 14, the portion of the top surface 512a that protrudes from the wall region 550d is indicated by hatching).

  Therefore, in the developing device, even if the wall region 550d between the openings of the hole 550c of the toner supply roller 550 contacts the top surface 512a of the convex portion 512, the top surface 512a is completely covered by the wall region 550d. Can be avoided more appropriately. Therefore, when the latent image is developed, it is possible to more appropriately avoid the occurrence of a non-developed portion in the toner image or the occurrence of a density unevenness due to the occurrence of a low-density portion.

  FIG. 14 is a schematic diagram for explaining the effectiveness of the developing device according to the present embodiment, in which the convex portion 512 of the developing roller 510 and the wall region 550d of the toner supply roller 550 are brought into contact with each other. FIG.

  Further, as described above, the layer thickness of the toner particles carried on the surface of the developing roller 510 is regulated by the plane that the regulating blade 560 has. Therefore, the toner particles carried on the surface of the developing roller 510 are not completely scraped off by the regulation blade 560, and the toner particles supplied only to a part of the top surface of the projection 512 are projected by the regulation blade 560. It is possible to spread evenly on the top surface of 512.

=== 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 example in which the printer includes a plurality of attaching / detaching portions has been described. However, a lid unit that can be closed by inserting a developing device to be attached to only one attaching / detaching portion is provided. You may be the structure provided. In the above-described embodiment, the image forming apparatus including the rotary developing device has been described as an example. However, the present invention is not limited to this. For example, the present invention can be applied to an image forming apparatus provided with a tandem developing device.

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

  Moreover, in the said embodiment, although the top surface 512a of the convex part 512 enclosed by two types of groove parts 511a and 511b was demonstrated to the square example, it does not restrict to this. FIG. 15 is a diagram illustrating a modification of the developing roller.

  In the developing roller 510 of the modified example, the top surface 512a of the convex portion 512 surrounded by the two types of groove portions 511 is a rhombus, and the groove portions are formed so that one of the two diagonal lines of each rhombus is along the circumferential direction. Has been.

  According to such a developing roller 510, since the groove portion 511 is formed so that one of the two diagonal lines of each rhombus is along the circumferential direction, one apex angle of the diagonal line along the circumferential direction. Therefore, two types of groove portions 511 are formed at the same angle on both end sides in the axial direction. For this reason, the toner particles T moved along the two types of grooves 511 are moved in substantially the same way toward both ends in the axial direction, and the toner particles can be moved without unevenness. This is the same as when the surface 512a is square. In addition, when the longer diagonal line of the two diagonal lines of the convex part 512 whose top face 512a forms a rhombus is along the circumferential direction, the convex part 512 whose rhombic top face 512a is in the circumferential direction. Two apex angles positioned along the axis become acute angles, and two apex angles positioned along the axial direction become obtuse angles. For this reason, the toner particles can be configured to move more easily in the circumferential direction.

=== 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. 16 is an explanatory diagram showing an external configuration of the image forming system. The image forming system 700 includes a computer 702, a display device 704, a printer 10, an input device 708, and a reading device 710.
The computer 702 is housed in a mini-tower type housing in this embodiment mode, but is not limited thereto. The display device 704 is generally a CRT (Cathode Ray Tube), a plasma display, a liquid crystal display device, or the like, but is not limited thereto. As the printer 10, the printer described above is used. As the input device 708, a keyboard 708A and a mouse 708B are used in this embodiment, but the present invention is not limited to this. In this embodiment, the reading device 710 uses a flexible disk drive device 710A and a CD-ROM drive device 710B. However, the reading device 710 is not limited to this. For example, an MO (Magneto Optical) disk drive device or a DVD (Digital Others such as Versatile Disk) may be used.

  FIG. 17 is a block diagram showing a configuration of the image forming system shown in FIG. An internal memory 802 such as a RAM and an external memory such as a hard disk drive unit 804 are further provided in a housing in which the computer 702 is housed.

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

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

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

FIG. 2 is a diagram illustrating main components constituting a printer. It is a figure for demonstrating the structure of the control unit with which the printer was equipped. It is a perspective view of a yellow developing device. It is sectional drawing which showed the main components of the yellow developing device. FIG. 6 is a perspective view showing a developing device with a developing roller removed. 6 is an enlarged schematic view of a cross section of a roller portion 550a of a toner supply roller 550. FIG. It is a conceptual diagram for demonstrating the surface shape of a developing roller. It is sectional drawing for demonstrating the cross section at the time of cut | disconnecting a developing roller by the plane which passes along an axis | shaft. FIG. 6 is a diagram for explaining a state in which a regulating blade is in contact with a developing roller carrying toner particles. It is a figure for demonstrating a mode that a developing roller is formed by rolling. It is a figure which shows the procedure in which a developing roller is formed. It is a schematic diagram for demonstrating the effectiveness of the developing device which concerns on this Embodiment. It is a schematic diagram for demonstrating the effectiveness of the developing device which concerns on this Embodiment. It is a schematic diagram for demonstrating the effectiveness of the developing device which concerns on this Embodiment. It is a figure which shows the 1st modification of a developing roller. 1 is an explanatory diagram showing an external configuration of an image forming system. It is a block diagram which shows the structure of the image forming system shown in FIG.

Explanation of symbols

10 printer, 20 photoconductor, 30 charging unit, 40 exposure unit,
50 Developer holding unit, 50a, 50b, 50c, 50d Detachable part,
50e central axis, 51 black developer, 52 magenta developer,
53 Cyan developer, 54 Yellow developer, 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, 111 CPU, 112 interface,
113 image memory, 116 memory, 120 CPU,
509 Non-rolled processing developing roller, 510 developing roller, 510a central portion,
510b end (both ends), 510c step, 510d surface,
511 groove part, 511a one groove part, 511b other groove part,
511c bottom surface, 511d inclined portion, 512 convex portion, 512a top surface,
513 flange, 513a flange body, 513b shaft,
515 cylindrical member, 520 upper seal, 522 seal support sheet metal,
524 seal urging member, 527 end seal, 530 toner accommodating portion,
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, 550a roller section,
550b shaft body, 550c hole, 550d wall region, 560 regulating blade,
560a rubber part, 560b rubber support part,
562 blade support sheet metal, 570 blade backing member, 572 opening,
700 image forming system, 702 computer, 704 display device,
708 input device, 708A keyboard, 708B mouse, 710 reader,
710A flexible disk drive device,
710B CD-ROM drive device,
802 internal memory, 804 hard disk drive unit,
900 dies, 900a blade, C axis, T toner (toner particles)

Claims (1)

A rotatable toner particle carrying roller having a plurality of convex portions on the surface for carrying toner particles for developing a latent image;
A rotatable toner particle supply roller for supplying the toner particles to the toner particles bearing roller in a porous foam,
Between the openings of the holes, the average distance in the axial direction of the toner particles carrying roller is rather smaller than the maximum width in the axial direction of the top surface of the convex portion,
The average distance in the circumferential direction of the toner particle carrying roller between the openings of the holes,
The ratio of the moving speed of the surface of the toner particle supply roller when the toner particle supply roller rotates to the moving speed of the surface of the toner particle support roller when the toner particle carrying roller rotates,
Toner particle supply roller has small than the maximum width divided by value, is in the circumferential direction of the top surface of the convex portion, the
A developing device comprising:

Images