JP2017090744A - Developing device, process cartridge, and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable a reduction in size in the axial direction in a developing device having a supply port located on the outside in the axial direction of an end in the axial direction of a developer carrier.SOLUTION: There is provided a developing device 5 comprising a developing roller 51 that includes a rotating developing sleeve; a roller bearing part 3 that rotatably supports the roller rotation shaft 51c; a supply conveyance path 53 that stores a developer to be supplied to the developing roller 51; and a toner supply port 7 that supplies a toner to the supply conveyance path 53 from the outside of the device, wherein the toner supply port 7 is located on the outside in the axial direction of an end in the axial direction of the developing roller 51, and the toner supply port 7 is arranged on the inside in the axial direction of the roller bearing part 3.SELECTED DRAWING: Figure 1

Description

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

Conventionally, as a developing device, two developer screws are provided in a developer accommodating portion disposed below a developing roller, and the developer in the developer accommodating portion is circulated by two conveying screws to reduce the amount of developer consumed. In response to this, there is known a method of additionally supplying a developer from the outside.
For example, the developing device described in Patent Document 1 has an arrangement in which two conveying screws arranged in parallel to the axial direction of the developing roller and the developing roller are arranged in a line in the vertical direction.

  The developing device shown in FIG. 1 of Patent Document 1 has a configuration in which two conveying screws are longer than the developing roller in the axial direction. In this developing device, a communication portion that communicates the supply conveyance portion in which each of the two screws in the developer accommodating portion is arranged and the stirring conveyance portion is provided outside the end portion in the axial direction of the developing roller. It is described that new toner is supplied in the vicinity of the communication portion. For this reason, it can be considered that a supply port for supplying toner is provided above the communication portion. In FIG. 1 of Patent Document 1, the casing on the outer side of the end portion of the developing roller on the side provided with the communicating portion in the axial direction is located on the inner side in the axial direction with respect to the communicating portion. Therefore, the bearing that rotatably supports the developing roller that is considered to be fixed to the casing is considered to be located on the inner side in the axial direction from the replenishing port that is considered to be located above the communicating portion. It is done. That is, in the developing device of Patent Document 1, the position of the supply port in the axial direction is considered to be outside the bearing of the developing roller.

  The axial length of the developer accommodating portion in which the transport screw is disposed and receives the toner replenished from the replenishing port is a length that extends at least from a range where the developing roller is located to a position below the replenishing port. However, in the configuration in which the replenishing port is arranged outside the bearing in the axial direction, the axial length necessary for arranging the bearing, such as the thickness of the bearing, with respect to the axial end of the developing roller. The replenishing port is arranged outside in the axial direction. In such a configuration, the developer accommodating portion that extends to a position below the replenishing port is longer in the axial direction by the axial length necessary for arranging the bearing, and the developer accommodating portion Is longer in the axial direction, leading to an increase in the axial size of the developing device.

  In order to solve the above-described problems, the present invention accommodates a rotating developer carrier, a bearing that rotatably supports the rotation shaft of the developer carrier, and a developer supplied to the developer carrier. And a replenishing port for replenishing developer from the outside of the apparatus with the replenishing port in the axial direction than the axial end of the developer carrier. The replenishing port is arranged on the inner side in the axial direction with respect to the bearing.

  According to the present invention, in the developing device in which the replenishing port is located on the outer side in the axial direction with respect to the axial end of the developer carrier, and the replenishing port is located on the inner side in the axial direction with respect to the bearing, There is an excellent effect that it is possible to reduce the size.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory diagram of a developing device according to an embodiment, (a) is a schematic top view, and (b) is a schematic side sectional view. 1 is a schematic configuration diagram of a copying machine. FIG. 3 is an enlarged explanatory diagram of an image forming unit. The expanded sectional view of a developing device. Sectional explanatory drawing of the image development apparatus in the GG cross section in FIG.1 (b). Sectional explanatory drawing of the image development apparatus in the HH cross section in FIG.1 (b). Sectional explanatory drawing of the cross section orthogonal to the axial direction in the position which provided the toner replenishment port of the developing device of a modification. FIG. 4 is an explanatory view of a developing device of Reference Configuration Example 1, (a) is a schematic top view, and (b) is a schematic side sectional view. Explanatory drawing of the image development apparatus of the reference structural example 2, (a) is a schematic top view, (b) is a schematic side sectional view.

Hereinafter, an embodiment of a copying machine (hereinafter referred to as “copying machine 500”) as an image forming apparatus to which the present invention is applicable will be described.
FIG. 2 is a schematic configuration diagram of the copying machine 500. As shown in FIG. 2, the copying machine 500 includes a scanner unit 32 that is an image reading unit above the apparatus main body 100, and a paper feeding unit 200 below the apparatus main body 100.
As shown in FIG. 2, four image forming units 6 (Y, Y) corresponding to the respective colors (yellow, magenta, cyan, black) are provided so as to face the lower surface of the intermediate transfer belt 8 of the intermediate transfer unit 10 in the apparatus main body 100. , M, C, Bk) are juxtaposed. Below these image forming units 6 (Y, M, C, Bk), an exposure device 60 as a latent image forming means is arranged.

  FIG. 3 is an enlarged explanatory view of one image forming unit 6 among the four image forming units 6 (Y, M, C, Bk) arranged in the apparatus main body 100 of the copying machine 500. Since the four image forming units 6 (Y, M, C, and Bk) have substantially the same configuration except that the colors of the toners to be used are different, in FIG. The alphabet (Y, M, C, Bk) shown will be omitted as appropriate.

  As shown in FIG. 3, the image forming unit 6 includes a drum-shaped photoconductor 1 as a latent image carrier, a charging unit 4 disposed around the photoconductor 1, a developing device 5 as a developing unit, a cleaning unit. 2 and the like (only the developing device 5 is shown in FIG. 2). An image forming process (charging process, exposure process, developing process, transfer process, cleaning process) is performed on the photoreceptor 1, and a desired toner image is formed on the photoreceptor 1.

The photoconductor 1, the charging unit 4, the developing device 5 and the cleaning unit 2 constituting the image forming unit 6 are each configured to be detachable from the apparatus main body 100, and each has a lifetime. When it reaches, it is exchanged for a new one.
In the present embodiment, the photoconductor 1, the charging unit 4, the developing device 5 and the cleaning unit 2 constituting the image forming unit 6 are each a single unit, but these are integrated and attached to and detached from the apparatus main body 100. A process cartridge can be installed freely. In this case, workability when performing maintenance of the image forming unit 6 is improved.

  The photosensitive member 1 is rotated in the clockwise direction in FIG. 3 (in the direction of arrow A in FIG. 3) by the photosensitive member driving motor, and the surface of the photosensitive member 1 is moved by the charging roller 4a at a position facing the charging unit 4. It is uniformly charged (charging process). Thereafter, the surface of the photoreceptor 1 reaches the irradiation position of the laser beam L emitted from the exposure device 60, and an electrostatic latent image is formed by exposure scanning at this position (exposure process). Thereafter, the surface of the photoreceptor 1 reaches a position facing the developing device 5, and the electrostatic latent image is developed at this position to form a desired toner image (developing process). Thereafter, the surface of the photoreceptor 1 reaches a primary transfer nip that faces the primary transfer bias roller 9 with the intermediate transfer belt 8 interposed therebetween, and the toner image on the surface of the photoreceptor 1 is transferred to the intermediate transfer belt 8 at the primary transfer nip. Transferred upward (primary transfer step). At this time, a slight amount of untransferred toner remains on the surface of the photoreceptor 1.

  Thereafter, the surface of the photoconductor 1 reaches a position facing the cleaning unit 2, and the transfer residual toner remaining on the photoconductor 1 at this position is collected by the cleaning blade 2a (cleaning step). The surface of the photoreceptor 1 after cleaning reaches a position facing the static eliminator, and the residual potential on the surface of the photoreceptor 1 is removed at this position. In this way, a series of image forming processes performed on the surface of the photoreceptor 1 is completed.

  The above-described image forming process is performed by each of the four image forming units 6 (Y, M, C, Bk) shown in FIG. That is, based on the image information read by the scanner unit 32 shown in FIG. 2, the laser beam L (see FIG. 3) is emitted from the exposure device 60 disposed below the image forming unit to each individual image forming unit 6 (see FIG. 3). Y, M, C, Bk) are irradiated toward the surface of the photoreceptor 1. Specifically, the exposure device 60 emits a laser beam L from a light source, and irradiates the surface of each photoconductor 1 via a plurality of optical elements while scanning the laser beam L with a polygon mirror that is rotationally driven. To do. Thereafter, the toner images of the respective colors formed on the surfaces of the individual photoreceptors 1 through the developing process are transferred onto the surface of the intermediate transfer belt 8 in an overlapping manner. In this way, a color image is formed on the surface of the intermediate transfer belt 8.

  The four primary transfer bias rollers 9 (Y, M, C, Bk) respectively sandwich the intermediate transfer belt 8 with the photoreceptor 1 (Y, M, C, Bk) to form primary transfer nips. Yes. A transfer bias having a polarity opposite to the charging polarity of the toner is applied to the primary transfer bias roller 9 (Y, M, C, Bk). The intermediate transfer belt 8 travels in the direction of arrow B in FIGS. 2 and 3 and sequentially passes through the primary transfer nips of the individual primary transfer bias rollers 9 (Y, M, C, Bk). In this way, the toner images of the respective colors on the surface of the photoreceptor 1 (Y, M, C, Bk) are primarily transferred on the surface of the intermediate transfer belt 8 to form a color toner image.

The intermediate transfer belt 8 on which the toner images of the respective colors are transferred in a superimposed manner reaches a position facing the secondary transfer roller 19. At this position, the secondary transfer backup roller 12 sandwiches the intermediate transfer belt 8 with the secondary transfer roller 19 to form a secondary transfer nip. The color toner image formed on the surface of the intermediate transfer belt 8 is transferred onto the surface of the transfer paper P as a recording medium conveyed to the secondary transfer nip position. At this time, the transfer residual toner that has not been transferred to the transfer paper P remains on the intermediate transfer belt 8, but the transfer residual toner on the intermediate transfer belt 8 is removed by the belt cleaning device.
Thus, a series of transfer processes performed on the surface of the intermediate transfer belt 8 is completed.

The transfer paper P that has been transported to the position of the secondary transfer nip described above is transported from the paper feed unit 200 disposed below the apparatus main body 100.
Specifically, a plurality of transfer sheets P are stored in the sheet feeding tray 26 in the sheet feeding unit 200 in a stacked manner. When the paper feed roller 27 is driven to rotate counterclockwise in FIG. 2, the uppermost transfer paper P is fed between the rollers of the registration roller pair 28.

  The transfer sheet P conveyed to the registration roller pair 28 temporarily stops at the position of the roller nip of the registration roller pair 28 that has stopped rotating. Then, the registration roller pair 28 is rotationally driven in synchronization with the color toner image on the surface of the intermediate transfer belt 8, and the transfer paper P is conveyed toward the secondary transfer nip. Thereafter, a desired color toner image is transferred onto the transfer paper P at the secondary transfer nip.

The transfer paper P on which the color toner image has been transferred at the position of the secondary transfer nip is conveyed to the position of the fixing device 20. At this position, the color toner image transferred onto the surface is fixed by heat and pressure generated by the fixing roller and the pressure roller. The transfer paper P that has passed through the fixing device 20 passes between the rollers of the paper discharge roller pair 29 and is discharged outside the device. The transfer paper P discharged from the apparatus main body 100 by the paper discharge roller pair 29 is sequentially stacked on the stack unit 30 as an output image.
Thus, a series of image forming processes in the copying machine 500 is completed.

The developing device 5 (Y, M, C, Bk) provided in each image forming unit uses a two-component developer composed of a toner and a carrier as a developer.
Above the intermediate transfer unit 10 of the apparatus main body 100 and below the stack unit 30 is a toner bottle 70 (a toner container that contains toner to be supplied to each developing device 5 (Y, M, C, Bk)). Y, M, C, Bk) is accommodated.

Next, the configuration of the developing device 5 provided in the image forming unit 6 will be described in more detail.
FIG. 4 is an enlarged cross-sectional view of the developing device 5. 1A and 1B are explanatory views of the developing device 5. FIG. 1A is a schematic top view, and FIG. 1B is a schematic side cross-sectional view of the developing device 5 when the developing device 5 is viewed from the left side in FIG. FIG. FIG. 4 is a cross-sectional view taken along the line FF in FIG.

As shown in FIGS. 3 and 4, the developing device 5 includes a developing roller 51 as a developer carrying member facing the photosensitive member 1. The developing roller 51 includes a cylindrical developing sleeve 51a that rotates in the direction of arrow C in FIG. 4 and a magnet roller 51b that is disposed inside the developing sleeve 51a and does not rotate.
A columnar developing doctor 52 that restricts the amount of developer carried on the surface of the developing roller 51 is disposed on the lower right side of the developing roller 51.

  The developing casing 50 that forms a developer accommodating portion that accommodates the developer supplied from the surface of the developing roller 51 forms a supply conveying path 53 and a circulation conveying path 54 as a developer accommodating portion below the developing roller 51. ing. The supply conveyance path 53 and the circulation conveyance path 54 are partitioned by a partition plate 63 of the developing casing 50. However, as shown in FIG. 1B, a supply downstream opening 64 and a supply upstream opening 65 are provided at both ends of the partition plate 63 in the axial direction (left-right direction in FIG. 1). The supply conveyance path 53 and the circulation conveyance path 54 communicate with each other through these openings.

  The developing device 5 includes a supply screw 55 in the supply conveyance path 53 and circulates in the circulation conveyance path 54 as two conveyance screws that are developer agitating and conveying members that convey the developer in the developer accommodating portion while stirring. A screw 56 is provided. Further, a toner concentration sensor that detects the toner concentration in the developer in the circulation conveyance path 54 is provided. The toner concentration sensor may be configured to detect the toner concentration in the developer in the supply conveyance path 53.

  As shown in FIG. 1B, the supply screw 55 and the circulation screw 56 that are conveying screws extend over the entire region from one end portion in the axial direction to the other end portion of the developing casing 50. The supply screw 55 conveys the developer in the supply conveyance path 53 in the direction of arrow E in FIG. 1 (the back direction in FIG. 4), and the developer that has reached the downstream end in the conveyance direction of the supply conveyance path 53 is It passes through the supply downstream opening 64 and is delivered to the upstream end of the circulating transfer path 54 in the transfer direction. The circulation screw 56 conveys the developer in the circulation conveyance path 54 in the direction of arrow D in FIG. 1 (front side in FIG. 4), and the developer that has reached the downstream end in the conveyance direction of the circulation conveyance path 54 It passes through the supply upstream opening 65 and is delivered to the upstream end of the supply conveyance path 53 in the conveyance direction. With such a configuration, the developing device 5 is configured such that the developer circulates between the supply conveyance path 53 and the circulation conveyance path 54.

  A part of the developer in the supply conveyance path 53 is pumped up on the surface of the developing roller 51 by the rotation of the supply screw 55 and the magnetic force of the magnet roller 51 b and is carried on the surface of the developing roller 51. As the developing sleeve 51a rotates, the carried developer reaches a portion facing the developing doctor 52, and the amount of the developer carried on the developing roller 51 is regulated by the developing doctor 52. The developer that has passed the restricting position by the developing doctor 52 is used for developing the electrostatic latent image on the photosensitive member 1 in a developing region that is a facing portion between the developing roller 51 and the photosensitive member 1. The developer that has passed through the developing region is separated from the surface of the developing roller 51 by the repulsive magnetic field formed by the magnet roller 51b, mixed with the developer in the supply conveyance path 53, and circulated in the developer containing portion. Returned to the flow.

  As shown in FIG. 4, the developing casing 50 is provided with an opening 58 communicating with the outside at the upper left in the drawing of the developing roller 51, and the opening 58 is provided with a filter 57 that prevents the developer from passing therethrough. . The opening 58 and the filter 57 constitute an exhaust mechanism that exhausts the air inside the developing casing 50 to the outside.

As shown in FIG. 4, in the developing device 5, the developing roller 51, the supply screw 55, and the circulation screw 56 are arranged in a substantially vertical line. With such an arrangement, compared to a configuration in which two conveying screws are arranged side by side in the horizontal direction, the width direction (the left and right sides in FIG. 4) becomes horizontal when the developing device 5 is viewed from the end in the axial direction. Direction) of the developing device 5 can be reduced.
Furthermore, by using a cylindrical member as the developing doctor 52, the size of the developing roller 51 in the normal direction can be reduced as compared with the configuration using a blade-like doctor member (doctor blade). Further, the blade-shaped doctor member has strength by bending an end portion on the opposite side to the side facing the developing roller, of both end portions in the short direction of the plate material extending in the axial direction. For this reason, the process which bends with respect to a board | plate material is needed. On the other hand, in this embodiment, since a cylindrical member can be used as it is as the developing doctor 52, the processing cost can be reduced.

  The supply screw 55 and the circulation screw 56 are arranged in the vertical direction, and the supply downstream side where the developer is dropped from the supply conveyance path 53 where the supply screw 55 is arranged to the circulation conveyance path 54 where the circulation screw 56 is arranged. A toner replenishing port 7 is disposed above the opening 64. The replenishing toner in the toner bottle 70 is conveyed by a toner replenishing device provided in the copying machine 500, and is supplied into the developing device 5 from the toner replenishing port 7 as indicated by an arrow β in FIG. .

An arrow I in FIG. 1 is a drawing direction of the developing device 5 with respect to the copying machine 500, the left side in FIG. 1 is the back side of the copying machine 500 shown in FIG. 2, and the right side in FIG. This is the front side. The developing casing 50 includes a rear side wall portion 50a at the rear end portion in the axial direction and a front side wall portion 50b at the front end portion in the axial direction.
The developing device 5 includes, as a roller bearing portion 3 that rotatably supports a roller rotation shaft 51c that is a rotation shaft of the developing roller 51, a back roller bearing portion 3a fixed to the back side wall portion 50a and a front side wall portion 50b. And a fixed front roller bearing portion 3b.
Further, the developing device 5 has a back side supply bearing portion 55a fixed to the back side wall portion 50a and a front side wall portion 50b as a bearing portion that rotatably supports a supply rotation shaft 55c that is a rotation shaft of the supply screw 55. And a fixed front supply bearing portion 55b.
Further, the developing device 5 includes a rear circulation bearing portion 56a fixed to the rear side wall portion 50a and a front side wall portion 50b as bearing portions that rotatably support the circulation rotation shaft 56c that is a rotation shaft of the circulation screw 56. And a fixed front circulation bearing portion 56b.

  FIG. 5 is a cross-sectional explanatory view of the developing device 5 taken along the line GG in FIG. A broken line in FIG. 5 indicates a projection surface obtained by projecting the developing roller 51 in the axial direction.

  As shown in FIGS. 1A and 5, the range in which the developing roller 51 is positioned in the width direction (X-axis direction in the drawing) is “γ”, and the range in which the toner supply port 7 is positioned is “ε”. At this time, the range “γ” where the developing roller 51 is positioned in the width direction and the range “ε” where the toner replenishing port 7 is positioned overlap each other in the range of “η” in FIGS. It has become. The toner supply port 7 is arranged vertically above a portion of the supply conveyance path 53 positioned vertically below the developing roller 51 and extending outward from the axial end of the developing roller 51.

  If the range “γ” where the developing roller 51 is positioned in the width direction and the range “ε” where the toner replenishing port 7 is positioned are arranged so as not to overlap, the following problem occurs. In order to reduce the size of the developing device 5 in the width direction, the toner replenishing port 7 is disposed in a range vertically above the supply conveyance path 53 so as not to overlap the range “γ” where the developing roller 51 is positioned in the width direction. When the toner replenishing port 7 is arranged, the opening width of the toner replenishing port 7 is narrowed. On the other hand, when the toner replenishing port 7 is arranged so that the opening width of the toner replenishing port 7 is secured and does not overlap the range “γ” in which the developing roller 51 is positioned in the width direction, the toner replenishing port 7 is connected to the supply conveyance path 53. It protrudes to the outer side in the width direction from the vertically upper range of. In such a configuration, the developing device 5 is increased in size in the width direction as the toner supply port 7 protrudes.

  In contrast, in the developing device 5 of the present embodiment, as described above, the range “γ” where the developing roller 51 is positioned in the width direction and the range “ε” where the toner replenishing port 7 is positioned are shown in FIG. It is the structure which overlaps in the range of "(eta)" in (a) and FIG. With such a configuration, the width of the developing device 5 can be reduced by arranging the toner replenishing port 7 within a range vertically above the supply conveyance path 53 while securing the opening width of the toner replenishing port 7. It becomes possible. As shown in FIG. 5, the thickness of the developing casing 50 around the roller rotation shaft 51c and the thickness (length in the width direction) of the developing roller 51 are substantially the same.

  Further, in the developing device 5 of this embodiment, as shown in FIG. 1, the toner replenishing port 7 is formed on the outer side in the axial direction of the developing roller 51 by providing a partition wall 62 between the developing roller 51. The partition plate 63 placed in the horizontal direction is a partition member that spatially partitions the supply transport path 53 and the circulation transport path 54 in the vertical direction. On the other hand, the partition wall 62 placed in the vertical direction is a partition member that spatially partitions, in the axial direction, the toner supply port 7 and the inner wall portion through which the toner passes below and the space where the developing roller 51 is disposed. Further, the partition wall 62 is a member having a smaller thickness than the back side roller bearing portion 3 a and the back side wall portion 50 a of the developing casing 50.

  An inner wall portion through which the toner from the opening of the toner supply port 7 toward the supply conveyance path 53 passes is formed in a cylindrical shape extending vertically in the developing casing 50 and extends to the vicinity of the supply screw 55. By forming in this way, the replenishment toner can be directly guided to the vicinity of the downstream end portion in the transport direction of the supply transport path 53 through which the developer is transported by the supply screw 55. In the vicinity of the downstream end of the supply conveyance path 53 in the conveyance direction, the developer continuously flows in by the supply screw 55, so that the replenishment toner supplied into the supply conveyance path 53 from the toner replenishment port 7 is on the developing roller 51 side. Can prevent backflow.

  As shown in FIG. 1, the roller rotation shaft 51c extends to the outside of each of the rear side wall portion 50a that is the rear side end portion in the axial direction of the developing casing 50 and the front side wall portion 50b that is the front side end portion. ing. A rear roller bearing portion 3a and a front roller bearing portion 3b that rotatably support the roller rotation shaft 51c are provided on the outer wall surfaces of the rear side wall portion 50a and the front side wall portion 50b. The roller rotation shaft 51c has a drive input gear fixed in the developing device drive section 59 outside the back side wall section 50a, and rotational drive is input through this drive input gear.

As shown in FIG. 1, on the far side of the developing device 5, the inner side of the developing roller 51, the toner supply port 7, the inner roller bearing portion 3 a, and the developing device driving unit 59 are arranged in this order from the inner side in the axial direction. It has a configuration.
Further, as shown in FIG. 1B, the rear roller bearing portion 3a, the rear supply bearing portion 55a, and the rear circulation bearing portion 56a are disposed outside the toner supply port 7 in the axial direction. A bearing part can be collectively fixed to the back side wall part 50a.
For this reason, the three rotation shafts (51c, 55c, and 56c) can be connected by a single drive unit called the developing device drive unit 59 provided on the outer side in the axial direction of the back side wall 50a. And the structure which rotates three rotary bodies (51, 55, and 56) by transmitting rotational drive from one drive source is realizable.

Here, the developing device of the reference configuration example in which the position of the toner supply port 7 in the axial direction is different from the developing device 5 of the present embodiment will be described.
8A and 8B are explanatory diagrams of the developing device 5 of Reference Configuration Example 1, in which FIG. 8A is a schematic top view and FIG. 8B is a schematic side sectional view. The developing device 5 of the reference configuration example 1 has the same configuration as the developing device 5 of the above-described embodiment except that the position of the toner supply port 7 in the axial direction is different.

  In the developing device 5 of the reference configuration example 1, the position of the toner replenishing port 7 in the axial direction is a roller bearing in which the positions of the developing roller 51 and the roller bearing portion 3 in the axial direction are shifted from the positions of the toner replenishing port 7. It is on the outer side in the axial direction than the portion 3 (front roller bearing portion 3b).

When fixing a bearing to the developer casing, the bearing must have a certain thickness (axial length) to ensure durability and shaft stability. Thickness is necessary. For this reason, in the developing device 5 of the reference configuration example 1, as shown in FIG. 8, apart from the rear side wall part 50a and the front side wall part 50b, a roller bearing holding wall part 50c having a certain thickness is provided. The front roller bearing portion 3b is fixed to the holding wall portion 50c. Further, the end of the roller rotation shaft 51c in the axial direction protrudes outward in the axial direction from the front roller bearing 3b.
The length in the axial direction necessary for arranging such a front roller bearing portion 3b is indicated by “κ” in FIG.

In the reference configuration example 1, the toner replenishing port 7 is disposed on the outer side in the axial direction from the front roller bearing portion 3b. Therefore, as shown in FIG. 8B, the supply conveyance path 53 and the circulation conveyance path 54 are axially arranged. It is necessary to extend the direction by “κ”.
The area indicated by “κ” in FIG. 8B is not an area for supplying the developer from the supply conveyance path 53 to the developing roller 51, nor an area for receiving the toner supplied from the toner supply port 7. In other words, in the developer accommodating portion including the supply conveyance path 53 and the circulation conveyance path 54, an area indicated by “κ” in FIG. 8B is a space for conveying the developer.

  A developing device 5 of Reference Configuration Example 1 shown in FIG. 8 is provided with a roller bearing holding wall portion 50c and a front roller bearing portion 3b adjacent to an end portion in the axial direction of the developing roller 51, and a developer containing portion is illustrated in FIG. 8 (b) is extended in the axial direction by the space indicated by “κ”, so that the entire developing device 5 is increased in size in the axial direction.

  On the other hand, in the developing device 5 of the present embodiment, as shown in FIG. 1B, the position of the toner replenishing port 7 in the axial direction is axially outside the axial end of the developing roller 51 ( On the back side, it is on the inner side (front side) in the axial direction than the roller bearing portion 3 (back side roller bearing portion 3a). In such an arrangement, the axial end of the developing roller 51 and the toner supply port 7 need only be separated by the thickness of the partition wall 62. The partition wall 62 only needs to be able to prevent the toner replenished from the toner replenishing port 7 from going to the space where the developing roller 51 is disposed. The partition wall 62 does not require the strength of a wall portion for fixing the bearing, and the thickness of the partition wall 62 Is sufficiently thinner than the wall for fixing the bearing.

In the developing device 5 according to the embodiment, the toner replenishing port 7 can be adjacent to the end portion in the axial direction of the developing roller 51 with the thin partition wall 62 interposed therebetween. Then, compared to the configuration of the reference configuration example 1, the axial length of the developer accommodating portion is set by the difference between the space length indicated by “κ” in FIG. 8B and the thickness of the partition wall 62. Can be shortened.
Therefore, in the developing device 5 of the embodiment, the length in the axial direction can be shortened as compared with the configuration in which the toner replenishing port 7 is disposed on the outer side in the axial direction than the roller bearing portion 3 as in Reference Configuration Example 1. This enables the developing device 5 to have a compact configuration in the axial direction.

  Further, in the developing device 5 of the reference configuration example 1, the developer accommodating portion to which the internal developer is conveyed by the two conveying screws extends in the axial direction, so that the developer circulation time becomes long and the toner supply is performed. It becomes impossible to catch up with the development in the development area, and a problem that the developed image becomes thin easily occurs. In order to shorten the developer circulation time, it is conceivable to increase the rotational speed of the two conveying screws. In this case, however, the temperature of the developing device increases and the life of the developing device decreases.

  On the other hand, in the developing device 5 of the embodiment, the axial length of the developer accommodating portion can be shortened and the developer circulation time can be shortened compared to the developing device 5 of the reference configuration example 1. Can do. Therefore, the occurrence of the above-described problems can be prevented.

8 includes a wall portion (50c) to which the roller bearing portion 3 on the side where the toner supply port 7 is provided in the axial direction is fixed, and a wall portion to which the bearings of the two conveying screws are fixed. The position in the axial direction is different from (55b). For this reason, it is impossible to collectively arrange driving units for transmitting driving to the three rotating bodies at the end portion on the side where the toner supply port 7 is provided in the axial direction. For this reason, as shown in FIG. 8, the roller bearing portion 3 and the bearings of the two conveying screws are fixed to one wall portion, and development is performed at the end opposite to the side where the toner supply port 7 is provided. A device driving unit 59 is provided.
In Reference Configuration Example 1, the end of the developing device 5 on the side where the developing device driving unit 59 is provided is the back side of the copier 500, and the end on the side where the toner supply port 7 is provided is the copier. The front side of 500.

On the other hand, in the developing device 5 of the embodiment, as shown in FIG. 1, the rotation input to the developing roller 51, the supply screw 55, and the circulation screw 56 is used as a developing device driving unit 59. It is arrange | positioned at the back end part. Further, the toner replenishing port 7 is also arranged at the rear end in the axial direction of the developing device 5.
Hereinafter, advantages of arranging the toner replenishing port 7 and the developing device driving unit 59 at the far end in the axial direction of the developing device 5 will be described.

  By disposing the toner replenishing port 7 at the rear end in the axial direction, the developing device 5 can be easily attached and detached from the front side of the apparatus main body 100. When the developing device 5 is pulled out from the near side as indicated by an arrow I in FIG. 1, if the toner replenishing port 7 is provided at the end on the near side in the axial direction, a replenishment path that faces the toner replenishing port 7 is temporarily provided. I need to move. During the movement of the replenishment path, the toner may fall from the replenishment path to a wide area around it and adhere to the periphery. When replacing a replacement module (such as the photosensitive member 1 or the intermediate transfer unit 10) in the vicinity, the user picks up the front side of the replacement module and pulls it out. My hands were dirty.

  On the other hand, by disposing the toner replenishing port 7 at the end on the back side in the axial direction, there is no need to move the replenishment path facing the toner replenishing port 7, and there is no toner dropping due to movement vibration of the replenishment path. Even if it falls, the range is narrow. When replacing a replacement module (such as the photosensitive member 1 or the intermediate transfer unit 10) in the vicinity, the user picks up the front side of the replacement module and pulls it out. Will not pollute you.

  Further, as shown in FIG. 2, toner is conveyed from a toner bottle 70 disposed above the intermediate transfer unit 10 to the developing device 5 disposed below the intermediate transfer unit 10. For this reason, if the toner replenishing port 7 is at the front end in the axial direction of the developing device 5, the replenishment path becomes obstructive, and the intermediate transfer unit 10 does not come out of the apparatus main body 100 or the replenishment path is detoured long. It becomes a configuration. For these reasons, it is desirable that the toner replenishing port 7 be disposed at the back end in the axial direction of the developing device 5.

  The number of parts can be reduced by disposing the developing device driving unit 59 at the back end in the axial direction. A part of the gear unit constituting the developing device driving unit 59 can be arranged on the near side in the axial direction. However, in that case, it is necessary to provide gears on both sides of the shaft member of the rotating body (developing roller 51, supply screw 55 or circulating screw 56) that transmits the rotational drive to the other rotating body in the developing device 5. Score increases. On the other hand, the gear unit, which is a drive transmission unit that inputs rotational drive to each rotating body, is collectively arranged on the far side in the axial direction as the developing device drive unit 59, thereby reducing the number of parts. Can do. Furthermore, it is desirable to arrange the gears in a line in consideration of shaft tilt and vibration. For these reasons, the developing device driving section 59 is disposed at the end portion in the axial direction of the developing device 5.

  In the developing device 5 of the present embodiment, the roller bearing portion 3 is provided outside the toner replenishing port 7 in the axial direction, so that the developing device driving unit 59 and the toner replenishing port 7 are connected to the developing device while reducing the size in the axial direction. The above-mentioned advantage by arrange | positioning in the back | inner side edge part of 5 can be acquired.

FIG. 9 shows a configuration in which the developing device driving portion 59 and the toner replenishing port 7 are arranged at the back end in the axial direction of the developing device 5, and the toner replenishing port 7 is provided outside the back roller bearing portion 3 a in the axial direction. FIG. 9 is an explanatory diagram of the developing device 5 of Reference Configuration Example 2; FIG. 9A is a schematic top view, and FIG. 9B is a schematic side sectional view. The developing device 5 of the reference configuration example 2 has the same configuration as the developing device 5 of the reference configuration example 1 described above, except that the development device drive unit 59 and the drive transmission unit 59a are provided.
In the reference configuration example 2, the developing roller 51 is rotationally driven by the developing device driving unit 59, and the rotation of the developing roller 51 is transmitted to the two conveying screws via the driving transmission unit 59a disposed on the front side in the axial direction. It has become.

  In the inner side roller bearing portion 3a on the side where the developing device driving portion 59 is provided, the inner side roller bearing portion 3a and a gear to which driving is transmitted by the developing device driving portion 59 are adjacent to each other. For this reason, the back roller bearing portion 3 a is located inside the toner supply port 7, and the developing device drive unit 59 and the toner supply port 7 are disposed at the back end in the axial direction of the developing device 5. That is, from the inner side in the axial direction of the developing device 5, the rear end portion of the developing roller 51, the roller bearing portion 3 (back side roller bearing portion 3 a), the developing device driving portion 59 and the toner supply port are arranged in this order. In the developing device 5 of the reference configuration example 2, since the developing device driving unit 59 is disposed, the space in the axial direction of the developer storage portion indicated by “κ” in FIG. The axial length of the portion is further increased, and the developing device 5 is enlarged in the axial direction.

  When the developing device driving portion 59 and the toner replenishing port 7 are arranged at the end in the axial direction of the developing device 5 and the toner replenishing port 7 is provided on the outer side in the axial direction of the roller bearing portion 3, it is described above. As in Reference Configuration Example 2, the entire developing device becomes larger in the axial direction. On the other hand, in the developing device 5 of the embodiment, by providing the toner replenishing port 7 on the inner side in the axial direction of the roller bearing portion 3, the developing device driving unit 59 and the toner replenishing port 7 are arranged in the axial direction of the developing device 5. With the configuration arranged at the back end, the axial size can be reduced.

  As shown in FIG. 1B, the toner replenishing port 7 is provided above the supply screw 55 and on the downstream side in the transport direction of the supply screw 55 with respect to the position where the developing roller 51 and the supply screw 55 face each other. Yes. Such an arrangement makes it possible to quickly supply new toner to the developer that has passed through the development region and returned to the supply conveyance path 53, that is, the developer that has consumed the toner.

  As shown in FIGS. 1 and 5, the developing device 5 supplies toner in a region facing the supply downstream side opening 64 in the supply conveyance path 53, that is, vertically above the developer delivery area to the circulation conveyance path 54. A mouth 7 is provided. As a result, the replenished toner flows to the circulation conveyance path 54 while being mixed with the developer in the supply conveyance path 53, so that the toner is easily taken into the developer. Further, the toner to be replenished to the transfer area where the developer falls toward the circulation conveyance path 54 falls, so that the moving direction becomes the same direction, and the replenished toner and the developer to be conveyed are easily mixed. If the replenished new toner does not completely mix with the developer in the developer accommodating portion and exists in the developer accommodating portion, it accumulates on the inner wall surface of the developing casing 50 or aggregates. On the other hand, the developing device 5 is configured to easily mix the replenished toner and the transported developer, thereby preventing problems.

  Further, an air flow is generated along with the flow of the developer from the supply conveyance path 53 toward the circulation conveyance path 54, and the replenished toner can easily follow the flow. For this reason, the effect of preventing the replenished toner from flowing back to the side of the region where the supply screw 55 and the developing roller 51 face each other in the supply conveyance path 53 can be enhanced.

  As described above, the toner replenished from the toner replenishing port 7 and the developer in the supply conveyance path 53 that has consumed the toner can be efficiently mixed. As a result, the developer can be uniformly stirred in the supply upstream side opening 65 until the developer is transferred from the circulation conveyance path 54 to the supply conveyance path 53, and the toner is uniformly dispersed from the supply conveyance path 53 to the developing roller 51. It becomes possible to supply a developer.

  A region indicated by “α” in FIG. 1 is a developer transport region in which the developer is carried and transported on the surface of the developing roller 51. As shown in FIG. 1, the end of the partition plate 63 between the supply screw 55 and the circulation screw 56 on the supply downstream side opening 64 side (the left end in FIG. 1) is the developer of the developing roller 51. It is located on the outer side in the axial direction from the transport area α. When the end of the partition plate 63 on the supply downstream side opening 64 side is at the same position as the end in the axial direction of the developer transport region α, or the position inside the axial direction, the developer is supplied and transported. In this case, the supply amount to the developing roller 51 may be insufficient. Further, since the bulk of the developer in the vicinity of the downstream end in the conveyance direction of the supply conveyance path 53 is reduced, a gap is formed above the supply screw 55, and the replenishment toner is in a region where the supply screw 55 and the developing roller 51 face each other. There is also a risk of troubles entering.

  On the other hand, in the developing device 5 of the present embodiment, the supply conveyance path is arranged by arranging the end portion on the supply downstream side opening portion 64 side to be located outside the developer conveyance region α in the axial direction. It is possible to prevent the developer from dropping and the bulk from being lowered in the vicinity of the downstream end portion in the transport direction 53. Thereby, it is possible to suppress the supply amount of the developer to the developing roller 51 from being insufficient or the supply toner from entering the region where the supply screw 55 and the developing roller 51 face each other.

FIG. 6 is a cross-sectional explanatory view of the developing device 5 in the HH cross section in FIG. 1, and is a cross-sectional explanatory view at a position where the partition wall 62 is provided.
As shown in FIG. 1B, the developing device 5 according to the embodiment has a configuration in which the replenishment position for taking in the toner replenished from the toner replenishing port 7 in the developer accommodating portion is close to the axial end of the developing roller 51. It has become. If the replenishment position is close to the developing roller 51, the replenished toner floats and enters the developing roller 51 side, and a problem of local density unevenness is likely to occur on the image.

  As shown in FIG. 6, the lower end 62a of the partition wall 62 that partitions the toner supply port 7 and the developing roller 51 is positioned below the roller rotation shaft 51c. Thereby, it is possible to suppress the supply toner from entering the region where the supply screw 55 and the developing roller 51 face each other, and it is possible to suppress the occurrence of local density unevenness on the image.

  Furthermore, as shown in FIG. 6, the shape of the lower end portion 62 a of the partition wall 62 is an arc shape with a certain distance from the outer diameter of the supply screw 55. Thereby, the gap between the area where the toner is supplied from the toner supply port 7 in the supply conveyance path 53 and the area where the developing roller 51 and the supply screw 55 face each other can be made the minimum gap. . For this reason, it is possible to more effectively suppress the supply toner from entering the region where the supply screw 55 and the developing roller 51 face each other, and it is possible to suppress the occurrence of local density unevenness on the image.

  As shown in FIG. 5, in the developing device 5 of the present embodiment, the opening (edge) of the toner replenishing port 7 is positioned above the developing roller 51, the developing device driving unit 59, and the roller bearing unit 3. The opening of the toner supply port 7 has a shape along a horizontal plane. Further, the developing device 5 is attached and detached along the horizontal direction as indicated by the arrow I in FIG. For this reason, the roller bearing portion 3 and the developing device driving portion 59 disposed on the back side in the axial direction located below the toner supply port 7 and the supply path on the apparatus main body 100 side connected to the toner supply port 7 include: A configuration that does not interfere when the developing device 5 is attached or detached can be realized.

Further, as shown in FIG. 5, the developing device 5 of the present embodiment is provided with a developing casing 50 so as to surround the roller rotating shaft 51c, and the roller rotating shaft 51c is not exposed in the toner supply port 7. ing. Thus, in the width direction orthogonal to the roller rotation shaft 51c, the roller rotation shaft 51c is not exposed to the supply path of the toner supply port 7, and the toner supplied to the toner supply port 7 does not contaminate the roller rotation shaft.
As shown in FIG. 5, below the toner supply port 7 is a supply downstream side opening 64 that is a developer delivery portion from the supply conveyance path 53 to the circulation conveyance path 54. For this reason, the replenished toner falls directly to the circulation conveyance path 54, and the developer conveyed in the supply conveyance path 53 joins, whereby the replenished toner and the developer in the developing device 5 are mixed. Mixing is promoted.

[Modification]
FIG. 7 is a cross-sectional explanatory view at a position where the toner supply port 7 is provided in the axial direction of the developing device 5 according to the modification. Since the modified example has the same configuration as the developing device 5 of the above-described embodiment except that the roller rotation shaft 51c is exposed in the supply path of the toner supply port 7, only the differences will be described.
As shown in FIG. 7, the developing device 5 of the modified example has a configuration in which the roller rotation shaft 51 c is exposed in the toner supply port 7 and the roller rotation shaft 51 c penetrates the toner supply port 7 in the axial direction. Compared to the configuration shown in FIG. 5, there is no portion covering the roller rotation shaft 51 c of the developing casing 50, so that the opening width of the toner supply port 7 can be widened.

In the developing device 5 of the modified example, the portion exposed in the toner replenishing port 7 of the roller rotation shaft 51c is configured such that newly replenished toner can come into contact therewith.
Therefore, a seal member 51d for preventing the passage of toner is provided between the inner peripheral surface of the hole provided for penetrating the roller rotation shaft 51c and the outer peripheral surface of the roller rotation shaft 51c in the back side wall portion 50a. . Further, a seal member for preventing the passage of toner is also provided on the partition wall 62 that forms a wall surface facing the back side wall portion 50a across the supply path of the toner supply port 7.

When the photosensitive member 1, the charging unit 4, the developing device 5, and the cleaning unit 2 constituting the image forming unit 6 are integrated into a process cartridge that is detachably installed in the apparatus main body 100, the developing device 5 described above is used. By providing, axial size reduction can be achieved.
In addition, since the copying machine 500 that is an image forming apparatus includes the developing device 5 described above as a developing unit, the depth of the device in the front-rear direction in FIG. 2 can be shortened, and the copying machine 500 can be shortened. The overall size of the apparatus can be reduced.

In the above-described embodiment, the developing device in which the developer carrier and the two conveying screws are arranged in a line in the vertical direction has been described. The characteristic configuration of the present embodiment is not limited to such a developing device, but can be applied to any developing device in which the replenishing port is positioned outside the developer carrier in the axial direction. For example, even in a developing device in which two conveying screws are arranged side by side in the horizontal direction, a replenishing port is provided as long as a replenishing port is provided in the developer containing portion in which a conveying screw positioned vertically below the developing roller is disposed. It is possible to apply a configuration in which the shaft is disposed inside the bearing in the axial direction. Further, even if the two conveying screws arranged in the horizontal direction are positioned obliquely below the developing roller, respectively, and a replenishing port is provided in the developer delivery area between the two developer containing portions, replenishment It is possible to apply a configuration in which the mouth is arranged on the inner side in the axial direction than the bearing.
Further, even in a developing device having three or more conveying screws, if the replenishing port is positioned outside the developer carrying member in the axial direction, the replenishing port is disposed inside the bearing in the axial direction. Configuration can be applied.

  The image forming apparatus is not limited to a color image forming apparatus including four developing devices, and can be applied to a monochrome image forming apparatus including one developing device.

  What was demonstrated above is an example, and there exists an effect peculiar for every following aspect.

(Aspect A)
A developer carrier such as a developing sleeve 51a that rotates, a bearing such as a roller bearing portion 3 that rotatably supports the rotation shaft of the developer carrier such as a roller rotation shaft 51c, and a developer that is supplied to the developer carrier. In a developing device such as a developing device 5 provided with a developer accommodating portion such as a supply conveyance path 53 that accommodates toner and a replenishing port such as a toner replenishing port 7 that replenishes developer from the outside of the device. The replenishing port is located on the outer side in the axial direction from the axial end of the carrier, and the replenishing port is disposed on the inner side in the axial direction from the bearing.
According to this, as described in the above embodiment, it is possible to reduce the axial size as compared with the developing device of the reference configuration example 1 in which the replenishing port is disposed outside the bearing in the axial direction. That is, in the reference configuration example 1, the developer accommodating portion is extended in the axial direction by the length in the axial direction necessary for arranging the bearing, such as the range indicated by “κ” in FIG. As a whole, this may lead to an increase in size in the axial direction. On the other hand, in the aspect A, in order to dispose the bearing, the replenishing port is disposed outside the end of the developer carrying member in the axial direction and inside the bearing in the axial direction. There is no need to extend the developer accommodating portion for the required axial length. Accordingly, it is possible to suppress an increase in the size of the developing device in the axial direction caused by the developer accommodating portion extending in the axial direction up to an axial length necessary for disposing the bearing. Therefore, it is possible to reduce the axial size of the developing device.

(Aspect B)
In the aspect A, the supply screw 55 and the circulation screw 56 having a rotation axis parallel to the rotation axis of the developer carrier such as the roller rotation shaft 51c in the developer accommodating portion such as the supply conveyance path 53 and the circulation conveyance path 54, etc. The two transport screws and the developer carrier are arranged in a line in the vertical direction.
According to this, as described in the above embodiment, the developing device can be downsized in the width direction, and the downsizing in the axial direction can also be achieved.

(Aspect C)
In either aspect A or B, the replenishing port such as the toner replenishing port 7 is positioned above the developer carrier such as the developing sleeve 51a.
According to this, as described in the above embodiment, the bearing such as the roller bearing portion 3 provided on the outer side in the axial direction with respect to the replenishing port and the replenishment path on the apparatus main body side such as the apparatus main body 100 include The structure which does not interfere in attachment / detachment of can be implement | achieved.

(Aspect D)
In any one of the aspects A to C, a partition wall such as a partition wall 62 is provided between a supply port such as the toner supply port 7 and a developer carrier such as the developing sleeve 51a, and a partition wall such as a lower end portion 62a. Is positioned below the rotation axis of the developer carrying member such as the roller rotation shaft 51c.
According to this, as described in the above embodiment, it is possible to suppress the supply toner from entering the region of the developer container that faces the developer carrying member, and local density unevenness occurs on the image. Can be suppressed.

(Aspect E)
In the aspect E, a developer screw such as a supply screw 55 having a rotation axis parallel to the rotation axis of the developer carrying member such as the roller rotation shaft 51c is provided in the developer accommodating portion such as the supply conveyance path 53, and the lower end 62a and the like. The shape of the lower end of the partition wall is an arc shape that is spaced apart from the outer diameter of the conveying screw.
According to this, as described in the above embodiment, the region where the developer such as toner is supplied from the replenishing port such as the toner replenishing port 7 in the developer collecting portion, the developer carrying member and the conveying screw face each other. It is possible to make the gap between the area to be a minimum gap. For this reason, it is possible to more effectively suppress the replenished developer from entering the region where the conveying screw and the developer carrying member face each other, and it is possible to suppress the occurrence of local density unevenness on the image.

(Aspect F)
In any one of the aspects A to E, the developer accommodating portion supplies the developer to the developer carrier such as the developing sleeve 51a, and is along the rotation axis of the developer carrier such as the roller rotation shaft 51c. A supply conveyance path such as a supply conveyance path 53 that conveys the developer is provided, and a supply port such as the toner supply port 7 communicates with the vicinity of the downstream end in the conveyance direction of the supply conveyance path and the outside of the apparatus.
According to this, as described in the above embodiment, a new developer can be quickly supplied to the developer that has consumed the developer such as toner.

(Aspect G)
In aspect F, the developer accommodating portion conveys the developer that has reached the downstream end in the conveyance direction of the supply conveyance path such as the supply conveyance path 53 to the upstream end of the supply conveyance path to circulate the developer. A circulation conveyance path such as the circulation conveyance path 54 is provided, and the position of the replenishment port such as the toner replenishment port 7 in the axial direction is transferred from the supply downstream side opening 64 or the like where the developer is transferred from the supply conveyance path to the circulation conveyance path. It is set within the range of the area.
According to this, as described in the above embodiment, the replenished developer flows because the replenished developer such as toner is mixed with the developer in the supply conveyance path and flows toward the circulation conveyance path. It becomes easy to be taken into the developer. As a result, it is possible to prevent such a problem that the replenished new developer accumulates or aggregates on the inner wall surface of the developing container such as the developing casing 50.

(Aspect H)
In the aspect G, the position in the axial direction of the transfer area such as the supply downstream opening 64 is higher than the area (developer transport area α and the like) that carries the developer on the surface of the developer carrier such as the developing sleeve 51a. Located outside.
According to this, as described in the above embodiment, the amount of developer supplied to the developer carrier is insufficient, or a new developer such as replenishment toner faces the developer carrier in the supply conveyance path. Entering the area can be suppressed.

(Aspect I)
In a process cartridge, comprising at least a latent image carrier such as the photosensitive member 1 that carries a latent image, and a developing unit that develops a toner image by attaching toner to the latent image on the surface of the latent image carrier. As a developing device, the developing device 5 or the like according to any one of the modes A to H is used.
According to this, as described in the above embodiment, it is possible to reduce the size of the process cartridge in the axial direction.

(Aspect J)
In an image forming apparatus such as a copying machine 500 including a latent image carrier such as the photosensitive member 1 and a developing unit that develops the latent image formed on the latent image carrier with a developer, the developing unit may include modes A to A. A developing device such as the developing device 5 according to any aspect of H is used.
According to this, as described in the above embodiment, it is possible to reduce the size of the entire image forming apparatus.

DESCRIPTION OF SYMBOLS 1 Photoconductor 2 Cleaning part 2a Cleaning blade 3 Roller bearing part 3a Back roller bearing part 3b Front roller bearing part 4 Charging part 4a Charging roller 5 Developing device 6 Image forming part 7 Toner supply port 8 Intermediate transfer belt 9 Primary transfer bias Roller 10 Intermediate transfer unit 12 Secondary transfer backup roller 19 Secondary transfer roller 20 Fixing device 26 Paper feed tray 27 Paper feed roller 28 Registration roller pair 29 Paper discharge roller pair 30 Stack part 31 Bottle storage part 32 Scanner part 50 Developing casing 50a Back side wall part 50b Front side wall part 50c Roller bearing holding wall part 51 Developing roller 51a Developing sleeve 51b Magnet roller 51c Roller rotating shaft 51d Sealing member 52 Developing doctor 53 Supply conveyance path 54 Circulation conveyance path 55 Supply screw 55a Back side supply bearing part 55b Front side supply Receiving portion 55c Supply rotation shaft 56 Circulating screw 56a Back-side circulation bearing portion 56b Front-side circulation bearing portion 56c Circulation rotation shaft 57 Filter 58 Opening 59 Developing device drive portion 59a Drive transmission portion 60 Exposure device 62 Partition wall 62a Lower end portion 63 Partition Plate 64 Supply downstream opening 65 Supply upstream opening 70 Toner bottle 100 Apparatus main body 200 Paper feed section 500 Copying machine L Laser beam P Transfer paper α Developer transport area

JP 2013-120288 A

Claims (10)

A rotating developer carrier;
A bearing that rotatably supports the rotation shaft of the developer carrier;
A developer accommodating portion for accommodating a developer to be supplied to the developer carrying member;
In a developing device comprising a replenishing port for replenishing the developer from the outside of the device,
The replenishing port is located outside the axial direction from the axial end of the developer carrier,
The developing device, wherein the replenishing port is arranged on the inner side in the axial direction than the bearing. The developing device according to claim 1.
Two transport screws having a rotation axis parallel to the rotation axis of the developer carrier in the developer accommodating portion,
The developing device, wherein the two conveying screws and the developer carrier are arranged in a line in a vertical direction. The developing device according to claim 1 or 2,
The developing device, wherein the replenishing port is located above the developer carrier. In the developing device according to any one of claims 1 to 3,
A partition wall is provided between the replenishing port and the developer carrier,
The developing device according to claim 1, wherein a lower end of the partition wall is positioned below a rotation axis of the developer carrying member. The developing device according to claim 4.
A transport screw having a rotation axis parallel to the rotation axis of the developer carrier in the developer accommodating portion,
The developing device according to claim 1, wherein a shape of a lower end of the partition wall is a circular arc shape spaced apart from the outer diameter of the conveying screw. The developing device according to any one of claims 1 to 5,
The developer container includes a supply conveyance path for conveying the developer along a rotation axis of the developer carrier while supplying the developer to the developer carrier.
The developing device, wherein the replenishing port communicates the vicinity of the downstream end of the supply conveyance path in the conveyance direction with the outside of the apparatus. The developing device according to claim 6.
The developer accommodating portion includes a circulation conveyance path that conveys the developer that has reached the downstream end in the conveyance direction of the supply conveyance path to the upstream end of the supply conveyance path, and circulates the developer.
The developing device according to claim 1, wherein a position of the replenishing port in the axial direction is set within a range of a delivery area where the developer is delivered from the supply conveyance path to the circulation conveyance path. The developing device according to claim 7.
The developing device according to claim 1, wherein a position of the delivery region in the axial direction is located outside a region carrying the developer on a surface of the developer carrying member. A latent image carrier for carrying a latent image;
In a process cartridge comprising at least developing means for developing a toner image by attaching toner to the latent image on the surface of the latent image carrier,
9. A process cartridge using the developing device according to claim 1 as the developing means. A latent image carrier;
An image forming apparatus comprising: a developing unit that develops the latent image formed on the latent image carrier with a developer;
An image forming apparatus using the developing device according to claim 1 as the developing unit.

Images