JP6159855B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus that includes a plurality of toner cartridges and forms a visible image with toner supplied from the toner cartridge.

  In recent years, techniques for reducing the size of image forming apparatuses have been developed. For example, Patent Document 1 discloses a technique in which a toner cartridge is attached to a developing device by inserting and removing a toner cartridge into and from a cartridge side tray in a state where the cartridge side tray is set in an inclined posture, and setting the cartridge side tray in an upright posture. Is described. With this technique, the image forming apparatus can be downsized.

JP 2007-65271 A (published on March 15, 2007)

  However, Patent Document 1 is a technology that realizes downsizing of an image forming apparatus from the viewpoint of only a toner cartridge, and does not consider other constituent members (for example, a photosensitive drum). Therefore, further downsizing of the image forming apparatus is required.

  SUMMARY An advantage of some aspects of the invention is that it provides an image forming apparatus that can be further downsized.

  In order to solve the above problems, an image forming apparatus according to an aspect of the present invention is an image forming apparatus including an image forming unit that forms a toner image on a photosensitive drum, and the image forming unit includes: A developing device for supplying toner onto the photosensitive drum, the developing device having a developing roller having an axis parallel to a first direction which is an axial direction of the photosensitive drum, and an axial direction of the developing roller; A developer container having a first agitation space and a second agitation space, which are two agitation spaces partitioned by a partition member, and containing a developer containing toner, and is installed in the first agitation space and rotates. A first conveying member that stirs and conveys the developer; and a second conveying member that is disposed in the second agitating space and rotates and stirs and conveys the developer, and the developing roller is disposed above the developing container. Placed on the top or When viewed, the shaft of the developing roller is located between the rotating shaft of the first conveying member and the rotating shaft of the second conveying member, and at one end of the developing container in the first direction. A toner replenishing port for taking in the toner is formed above the first stirring space, and the photosensitive drum is positioned on the first stirring space side of the developing roller.

  According to one embodiment of the present invention, an image forming apparatus that can be further downsized can be provided.

1 is a perspective view of an image forming apparatus according to an embodiment of the present invention. FIG. 2 is an explanatory diagram illustrating an open / close state of a side opening / closing door in the image forming apparatus illustrated in FIG. 1. FIG. 3 is a perspective view of the image forming apparatus when a side opening / closing door and a toner cartridge are removed. FIG. 2 is a longitudinal sectional view showing an internal structure of the image forming main body device when the image forming main body device included in the image forming apparatus shown in FIG. 1 is viewed from the right side. FIG. 5 is a perspective view illustrating a developing device provided in the image forming main body apparatus illustrated in FIG. 4. FIG. 6 is a perspective view showing a developing container provided in the developing device shown in FIG. 5. It is a perspective view which shows the tank main body part with which the developing container shown in FIG. 6 is provided. It is a top view of the tank main-body part shown in FIG. 3 is an explanatory diagram illustrating a positional relationship among a developing roller, a developing container, and a photosensitive drum when viewed from the right side of the image forming apparatus. FIG. 3 is an explanatory diagram illustrating a positional relationship among a developing roller, a developing container, a photosensitive drum, and a toner cartridge when viewed from the right side of the image forming apparatus. FIG. 3 is an explanatory diagram showing a positional relationship between a toner cartridge and a developing device when viewed from the entire surface side of the image forming apparatus. FIG.

(Overall configuration of image forming apparatus)
Embodiments of the present invention will be described below with reference to the drawings. In the following description, the right side facing the image forming apparatus is called the right side of the image forming apparatus, and the left side facing the image forming apparatus is called the left side of the image forming apparatus.

  FIG. 1 is an external perspective view of an image forming apparatus according to an embodiment of the present invention. As shown in FIG. 1, the image forming apparatus 1 includes an image forming main body device 2 and an automatic document feeder 3 installed on the image forming main body device 2.

  The automatic document feeder 3 includes a document set tray 61 and a paper discharge tray 62. The document placed on the document set tray 61 is transported to a document reading unit (not shown) and then discharged onto the paper discharge tray 62. . The document reading unit is provided inside the automatic document feeder 3 and above the image forming main body device 2.

  In the present embodiment, the automatic document feeder 3 conveys (feeds) a document placed on the document set tray 61 in the direction of the left surface of the image forming main body 2 when reading a document image. It has become. Specifically, the original is conveyed from the original set tray 61 toward the left side of the image forming main body apparatus 2, read by the original reading unit, then conveyed toward the right side of the image forming main body apparatus 2, and discharged. It is discharged onto the tray 62.

  In the present embodiment, the image forming main body device 2 is a full-color printer. Therefore, the image forming main body device 2 prints a color image on a sheet (sheet-like recording medium) according to image data transmitted from the outside. Here, the image forming main unit 2 is exemplified as a printer, but it may be a copier, a facsimile machine, or a multifunction machine having these functions. In this case, the image forming main body device 2 prints a multicolor or single color image on a sheet according to image data transmitted from the outside and / or image data read from a document by a scanner.

  The image forming main body device 2 includes four toner cartridges 71 to 74 of yellow, magenta, cyan, and black, and a process unit 11 that forms a toner image using the four color toners supplied from each of the toner cartridges 71 to 74. And a waste toner box 69 for collecting waste toner discharged from the process unit 11. The toner cartridges 71 to 74, the process unit 11, and the waste toner box 69 are detachable from the right side of the image forming main body apparatus 2, and are exchanged as necessary. The process unit 11 is located on the back side (left side) of the image forming main body 2 with respect to the toner cartridges 71 to 74 and the waste toner box 69. Therefore, in order to take out the process unit 11, it is necessary to take out the toner cartridges 71 to 74 and the waste toner box 69 first.

  The image forming main body device 2 has a side opening / closing door on the right side. By opening the side door, the toner cartridges 71 to 74, the process unit 11, and the waste toner box 69 can be attached and detached. FIG. 1 shows the external appearance when the side opening / closing door is removed. When the replacement of the toner cartridges 71 to 74 or the process unit 11 or the waste toner box 69 is completed, it is covered with a side opening / closing door.

  FIG. 2 is a view showing opening and closing of the side opening / closing door 101. As shown in FIG. 2, the side opening / closing door 101 can be opened / closed in the vertical direction around the rotation fulcrum shaft 102 at the lower end. In the present embodiment, the side opening / closing door 101 is opened at three stages of first to third opening angles. The first opening angle is 30 ° to 45 °, the second opening angle is 45 ° to 75 °, and the third opening angle is 90 ° to 110 °. The toner cartridges 71 to 74 can be replaced when opened to the first opening angle, and the toner cartridges 71 to 74 and the waste toner box 69 can be replaced when opened to the second opening angle. Thus, the toner cartridges 71 to 74, the waste toner box 69, and the process unit 11 can be replaced when opened to the third opening angle.

  The process unit 11 includes five waste toner conveyance pipes 36a and 45a1 to 45d1 protruding to the right side of the image forming main body device 2, and four toner intake portions 431a to 431d for taking in the toner. .

  When the process unit 11 and the waste toner box 69 are attached to the image forming main body apparatus 2, the waste toner transport pipes 36a and 45a1 to 45d1 are connected to the waste toner box 69, and the waste discharged from the waste toner transport pipes 36a and 45a1 to 45d1. Toner is stored in a waste toner box 69.

  When the process unit 11 and the toner cartridges 71 to 74 are attached to the image forming main body apparatus 2, the toner take-in portions 431 a to 431 d are connected to the toner cartridges 71 to 74, respectively, and take in toner from the toner cartridges 71 to 74.

  The waste toner box 69 has a thin rectangular box shape. On the upper part of the waste toner box 69, first to fifth five extending portions 91 to 95 connected to the waste toner transport pipe of the process unit are formed. The first to fifth extending portions 91 to 95 are connected to the internal space of the waste toner box 69. When the process unit 11 and the waste toner box 69 are mounted on the image forming main body apparatus 2, the toner intake portions are respectively provided in the four gaps of the first to fifth extending portions 91 to 95 as shown in FIG. 431a to 431d are located.

  The toner cartridges 71 to 74 are arranged side by side in the front-rear direction of the image forming apparatus 1 above the waste toner box. FIG. 3 is a perspective view illustrating an appearance of the image forming apparatus 1 when the toner cartridges 71 to 74 are removed. As shown in FIG. 3, four cartridge mounting portions 65 to 68 are provided in the upper portion of the right surface side position of the image forming main body device 2. The cartridge mounting portions 65 to 68 have a vertically long shape in the vertical direction, and are arranged in the front-rear direction of the image forming apparatus 1 at the same height position. The cartridge mounting portions 65 to 68 have a structure in which adjacent ones are connected and integrated, and are provided corresponding to the four toner intake portions 431a to 431d. As shown in FIG. 1, toner cartridges 71 to 74 are mounted on the cartridge mounting portions 65 to 68, respectively.

  The toner cartridges 71 to 74 contain yellow, magenta, cyan, and black toners, respectively. When the toner cartridges 71 to 74 are mounted in the cartridge mounting portions 65 to 68, the toner supply portions 431 a to 431 d of the corresponding process units 11 are connected to the toner supply openings 431 a to 431 d, respectively. Is possible. The group of toner cartridges 71 to 74 are arranged on the right side of the image forming main body device 2 at a position closer to the front side with respect to the center position in the front-rear direction of the image forming main body device 2.

  Here, the upper portions of the cartridge mounting portions 65 to 68 are disposed inside the right vertical wall portion 82 of the left and right vertical wall portions 81 and 82 of the image forming main body apparatus 2. The vertical wall portions 81 and 82 are provided at the left and right positions of the paper discharge tray 16, and are formed so that the upper surface of the housing is higher than the upper surface of the paper discharge tray 16 in order to hold the paper on the paper discharge tray 16. Has been.

  Therefore, the toner cartridges 71 to 74 are arranged using the space inside the vertical wall portion 82, and have a large capacity as a vertically long shape, making it easy to secure a desired capacity. As a result, even when the toner cartridges 71 to 74 are vertically long and have a large capacity, it is possible to suppress an increase in the size of the image forming main body device 2 (image forming device 1), and the toner cartridges 71 to 74 Exchange frequency can be reduced.

(Internal configuration of image forming main unit)
FIG. 4 is a longitudinal sectional view showing the internal structure of the image forming main body device 2 when the image forming main body device 2 is viewed from the right side. In FIG. 4, the left side is the front side of the image forming main body apparatus 2, and the right side is the back side.

  As shown in FIG. 4, the image forming main body device 2 is provided with a process unit 11 at the center in the vertical direction. A laser optical system unit 12 and a paper feed cassette 13 are provided below the process unit 11 sequentially from the top. Further, a transfer unit 14 is provided at a position on the back side with respect to the process unit 11, and a fixing unit 15 is provided above the transfer unit 14. An upper surface of the housing of the image forming main body 2 above the process unit 11 is a paper discharge tray 16.

  A paper transport path 17 is formed in the path from the paper feed cassette 13 to the paper discharge tray 16, and the paper transport path 17 has a paper feed roller 18, A timing roller 19, the transfer unit 14, the fixing unit 15, and a paper discharge roller 20 are provided.

  The process unit 11 includes first to fourth image forming units 31 to 34, an intermediate transfer belt unit 35, and a transfer belt cleaning device 36.

  The first to fourth image forming units 31 to 34 are for yellow, magenta, cyan, and black, respectively, and form toner images of different colors on the photosensitive drum. The first to fourth image forming units 31 to 34 are sequentially arranged along the front-rear direction (second direction) of the image forming main body device 2. Here, the first to fourth image forming units 31 to 34 are arranged in the front-rear direction, which is a horizontal direction perpendicular to the axial direction of the photosensitive drum (the left-right direction of the image forming apparatus).

  The first image forming unit 31 includes a photoreceptor drum 41a, a charger 42a, a developing device 43a, an intermediate transfer roller 44a, and a photoreceptor cleaning device 45a.

  The photosensitive drum 41a is a cylindrical photosensitive member whose axial direction (first direction) is the left-right direction of the image forming main body device 2. The charger 42a charges the surface of each photosensitive drum 41a to a predetermined potential. The developing device 43a develops the electrostatic latent image formed on the surface of the photosensitive drum 41a with toner by exposing the photosensitive drum 41a to the laser light from the laser optical system unit 12. The intermediate transfer roller 44 a is disposed on the back surface of the intermediate transfer belt 51, and transfers the toner image formed on the surface of the photosensitive drum 41 a by development onto the surface of the intermediate transfer belt 61 of the intermediate transfer belt unit 35. The photoconductor cleaning device 45a removes and collects residual toner and paper dust on the surface of the photoconductor drum 41a after development and image transfer.

  Similarly, the second image forming unit 32 includes a photoreceptor drum 41b, a charger 42b, a developing device 43b, an intermediate transfer roller 44b, and a photoreceptor cleaning device 45b. The third image forming unit 33 includes a photoreceptor drum 41c, a charger 42c, a developing device 43c, an intermediate transfer roller 44c, and a photoreceptor cleaning device 45c. The fourth image forming unit 34 includes a photoreceptor drum 41d, a charger 42d, a developing device 43d, an intermediate transfer roller 44d, and a photoreceptor cleaning device 45d.

  The intermediate transfer belt unit 35 includes an intermediate transfer belt 51, a driving roller 52 that supports the intermediate transfer belt 51, a driven roller 53, and tension rollers 54 and 55.

  The transfer belt cleaning device 36 removes residual toner and paper dust from the surface of the intermediate transfer belt 51.

  The laser optical system unit 12 includes laser light sources 12a to 12d corresponding to the photosensitive drums 41a to 41d, and irradiates the photosensitive drums 41a to 41d with laser light from the laser light sources 12a to 12d. The electrostatic latent images corresponding to the image to be printed are formed on the surfaces of the photosensitive drums 41a to 41d.

  The transfer unit 14 includes a transfer roller 14 a that is pressed against the drive roller 52 of the intermediate transfer belt unit 35 via the intermediate transfer belt 51, and a sheet on which the toner image on the surface of the intermediate transfer belt 51 is supplied from the paper feed cassette 13. Transcript to.

  The fixing unit 15 includes a fixing roller 15a and a pressure roller 15b, and melts and fixes the toner image on the paper to the paper.

(Image forming operation)
In the image forming main body 2 having the above configuration, when printing a color image, the laser optical system unit 12 irradiates the photosensitive drums 41a to 41d with laser light in accordance with the input image data, and the photosensitive member. Electrostatic latent images are formed on the drums 41a to 41d. These electrostatic latent images are developed with toner supplied from developing devices 43a to 43d, and yellow, magenta, cyan, and black toner images are formed on the surfaces of the photosensitive drums 41a to 41d, respectively.

  These toner images are transferred to the same position on the intermediate transfer belt 51 of the intermediate transfer belt unit 35 so as to overlap each other, and further transferred onto the paper in the transfer unit 14.

  The sheet is fed from the sheet feeding cassette 13 to the sheet conveying path 17 by the sheet feeding roller 18, and is supplied to the transfer unit 14 by the timing roller 19 at a timing coincident with the toner image on the intermediate transfer belt 51.

  The sheet on which the toner image is transferred in the transfer unit 14 is conveyed to the fixing unit 15, and the toner image is fixed on the sheet in the fixing unit 15. Thereafter, the paper is discharged onto the paper discharge tray 16 by the paper discharge roller 20. That is, the paper discharge tray 16 receives printed paper discharged from the back side of the image forming main body device 2 (image forming device 1).

  In the image forming apparatus 1, since the fixing unit 15 is located on the back side, the heat (hot air) generated in the fixing unit 15 is transmitted to the user located on the front side of the image forming apparatus 1. Will never feel uncomfortable.

(Developer)
Next, the configuration of the developing devices 43a to 43d provided in the first image forming unit 31 to the fourth image forming unit 34 will be described. Since all the developing devices 43a to 43d have the same configuration, only the developing device 43a will be described here.

  FIG. 5 is a perspective view showing the appearance of the developing device 43a. As shown in FIG. 5, the developing device 43a includes a developing roller 432a having an axis parallel to the axial direction of the corresponding photosensitive drum 41a, a developing container 433a extending in the axial direction of the developing roller 432a, and a developing roller 432a. And a doctor blade 434a installed at an opposing position.

  The developing container 433a is a tank that accommodates a two-component developer containing toner supplied from the corresponding toner cartridge 71 and a carrier (in this embodiment, a magnetic carrier having magnetism) while stirring. The developing container 433a includes a box-shaped tank body 435a whose upper surface is open, and a cover member 436a that covers the tank body 435a. 6 is a perspective view showing the developing container 433a when the cover member 436a is attached to the tank body 435a, and FIG. 7 is a perspective view showing the tank body 435a when the cover member 436a is removed. . FIG. 8 is a top view of the tank body 435a.

  7 and 8, the tank body 435a has a partition plate 437a parallel to the axial direction of the developing roller 432a, and the partition plate 437a allows the first stirring space 438a and the second stirring space 439a. It is divided into and. The length of the partition plate 437a in the longitudinal direction (direction parallel to the axial direction of the developing roller 432a) is shorter than the length in the longitudinal direction (direction parallel to the axial direction of the developing roller 432a) in the internal space of the tank body 435a. . The partition plate 437a is separated from the both ends in the longitudinal direction of the tank body 435a by a predetermined distance. Therefore, the 1st stirring space 438a and the 2nd stirring space 439a are connected in the both ends of the longitudinal direction of the tank main-body part 435a. Here, the communication portion close to the left surface of the image forming apparatus 1 is referred to as a first communication portion 440a, and the communication portion close to the right surface of the image forming apparatus 1 is referred to as a second communication portion 441a.

  As shown in FIG. 8, the tank body 435a has a first transport member 442a installed in the first stirring space 438a and a second transport member 443a installed in the second stirring space 439a. . The 1st conveyance member 442a and the 2nd conveyance member 443a are comprised by the screw auger which consists of a rotating shaft which rotates integrally with a helical conveyance blade | wing and the said conveyance blade | wing. A driving motor is connected to the end portions of the first conveying member 442a and the second conveying member 443a near the left surface of the image forming apparatus 1, and the first conveying member 442a and the second conveying member 443a are rotated by the driving motor. Be controlled. Here, the developer contained in the tank main body 435a is circulated and conveyed in the first agitating space 438a → the first communicating portion 440a → the second agitating space 439a → the second communicating portion 441a → the first agitating space 438a →. As described above, the rotation of the first transport member 442a and the second transport member 443a is controlled. 7 and 8, the developer transport direction is indicated by arrows.

  As shown in FIG. 6, the cover member 436a is a cover that covers the upper part of the tank main body 435a, and on the upper surface of the first stirring space 438a near the end on the right surface side of the image forming apparatus 1, A toner supply port 444a for receiving is formed. The cover member 436a has an opening 445a for supplying the developer to the developing roller 432a on the upper surface of the second stirring space 439a. In a region other than the toner supply port 444a and the opening 445a, the cover member 436a covers the top of the tank body 435a. That is, the cover member 436a covers the upper part of the first stirring space 438a except for the toner supply port 444a, and partitions the first stirring space 438a and the developing roller 432a.

  Here, as shown in FIG. 1, the end portion of the developing container 433a where the toner supply port 444a is formed protrudes to the right side of the image forming main body 2 in the process unit 11, as shown in FIG. 431a. Therefore, by arranging the toner cartridge 71 on the upper portion and connecting the toner supply port 444a and the toner cartridge 71, the toner can be supplied to the developing container 433a.

  As shown in FIG. 8, the toner take-in portion 431 a is located between the side opening / closing door 101 that is a part of the housing of the image forming main body device 2 rather than the frame 85 of the image forming main body device 2. Part.

  The developing roller 432a is a magnet roller that is driven to rotate about an axis by a driving unit (not shown), and is for conveying the toner contained in the developer in the developing container 433a to the photosensitive drum. FIG. 9 is a diagram showing a positional relationship among the developing roller 432a, the developing container 433a, and the photosensitive drum 41a when viewed from the axial direction of the developing roller 432a. As shown in FIG. 9, the developing roller 432a is positioned above the developing container 433a, and the axis A of the developing roller 432a is the axis B of the first conveying member 442a and the axis C of the second conveying member 443a. It is located above the approximate middle point. That is, as shown in FIG. 8, the projection area of the developing roller 432a when viewed from above overlaps both the first stirring space 438a and the second stirring space 439a and is included in the projection area of the developing container 433a. It is. Therefore, the area occupied by the developing device 43a in the front-rear direction of the image forming apparatus 1 can be reduced. As a result, when the first to fourth image forming units 31 to 34 are arranged side by side in the front-rear direction, the area occupied by the first to fourth image forming units 31 to 34 in the front-rear direction of the image forming apparatus 1 is reduced. The length of the process unit 11 in the front-rear direction can be reduced.

  The developing roller 432a is provided to face the photosensitive drum 41a and be separated from the photosensitive drum 41a with a gap. The photosensitive drum 41a is disposed at a position obliquely above the first stirring space 438a with respect to the developing roller 432a. The developer conveyed by the developing roller 432a comes into contact with the photosensitive drum 41a at the closest portion, and develops (develops) the electrostatic latent image formed on the surface of the photosensitive drum 41a.

  The doctor blade 434a is a plate-like member that extends parallel to the axial direction of the developing roller 432a, and is provided so as to be separated from the surface of the developing roller 432a with a predetermined amount of gap. Thereby, the amount of the developer on the developing roller 432a can be made uniform.

(Position relationship between toner cartridge, developing device and photosensitive drum)
Next, the positional relationship among the toner cartridge, the developing device, and the photosensitive drum will be described. FIG. 10 is a diagram showing the positional relationship among the developing roller 432a, the developing container 433a, the photosensitive drum 41a, and the toner cartridge 71 when viewed from the right side of the image forming apparatus. In FIG. 10, the projected areas of the developing roller 432a and the photosensitive drum 41a are indicated by dotted lines.

  As shown in FIG. 10, the toner supply port 444a formed above the end of the first stirring space 438a and the toner cartridge 71 are connected. At this time, as illustrated, the toner cartridge 71 is disposed at a position facing the developing roller 432a and the photosensitive drum 41a in the axial direction. Thereby, when viewed from the axial direction of the developing roller 432a, the positions of the developing roller 432a and the photosensitive drum 41a and the toner cartridge 71 are not shifted. Therefore, even when the four first to fourth image forming units 31 to 34 are arranged side by side, the image forming apparatus 1 in the entire four first to fourth image forming units 31 to 34 and the toner cartridges 71 to 74 is arranged. The length in the front-rear direction can be shortened. That is, space saving can be achieved.

  More specifically, when viewed from the axial direction of the developing roller 432a, the projected area of the toner cartridge 71 includes the projected areas of the developing roller 432a and the photosensitive drum 41a. In each of the first to fourth image forming units 31 to 34, the sizes of the photosensitive drum and the developing roller are relatively large. Since such a relatively large photosensitive drum and developing roller projection area is included in the toner cartridge projection area, a sufficient amount of toner is accommodated in each of the toner cartridges 71 to 74. be able to.

  When viewed from above, the toner replenishing port 444a on the first stirring space is located between the axis D of the photosensitive drum 41a and the axis A of the developing roller 432a. As described above, the toner cartridge 71 is disposed at a position facing the developing roller 432a and the photosensitive drum 41a in the axial direction. Therefore, the toner supply port 444a is positioned vertically below the toner cartridge 71, and the toner can be smoothly supplied from the toner cartridge 71 to the toner supply port 444a.

  FIG. 11 is a longitudinal sectional view showing a connection structure between the toner cartridge 71 and the developing container when viewed from the front-rear direction of the image forming apparatus 1. As shown in FIG. 11, the cartridge mounting portions 65 to 68 are attached to the frame 85 of the image forming main body device 2. Therefore, the toner cartridges 71 to 74 are mounted between the frame 85 and the side surface opening / closing door 101 which is a part of the casing of the image forming main body apparatus 2. Further, a toner intake portion 431 a including a toner supply port 444 a is also located between the frame 85 and the side surface opening / closing door 101. Accordingly, the toner cartridges 71 to 74 and the cartridge mounting portions 65 to 68 are arranged by effectively using the space existing in the image forming main body apparatus 2 (image forming apparatus 1).

  Further, as shown in FIG. 11, a toner scattering prevention member 446a formed of sponge or the like is provided around the connection portion between the toner cartridge 71 and the toner supply port 444a.

(Summary)
As described above, the image forming apparatus 1 according to this embodiment includes the photosensitive drums 41a to 41d, and a plurality of first to fourth images that form toner images of different colors on the photosensitive drums 41a to 41d. The formation parts 31-34 are provided. The first to fourth image forming units 31 to 34 are arranged in the front-rear direction (second direction) of the image forming apparatus 1, which is a horizontal direction perpendicular to the axial direction (first direction) of the photosensitive drums 41a to 41d. They are arranged side by side.

  The first to fourth image forming units 31 to 34 include developing devices 43a to 43d that supply toner onto the photosensitive drums 41a to 41d, respectively. The developing device 43a has two spaces partitioned by a developing roller 432a having an axis parallel to the axial direction (first direction) of the photosensitive drums 41a to 41d and a partition member 437a along the axial direction of the developing roller 432a. A developer container 433a having a first agitation space 438a and a second agitation space 439a for containing a developer containing toner, and a first conveyance that is installed in the first agitation space 438a and agitates and conveys the developer by rotating. A member 442a and a second transport member 443a that is installed in the second stirring space 439a and rotates to stir and transport the developer are provided. The other developing devices 43b to 43d have the same configuration.

  Here, the developing roller 432a is disposed on the developing container 433a. When viewed from above, the developing roller 432a has a shaft between the rotation shaft of the first transport member 442a and the rotation shaft of the second transport member 443a. positioned.

  Thereby, the size of the area occupied by the developing device in the front-rear direction (second direction) of the image forming apparatus 1 can be reduced. As a result, when the first to fourth image forming units 31 to 34 are arranged side by side, the area occupied by the first to fourth image forming units 31 to 34 in the front-rear direction (second direction) of the image forming apparatus 1 is large. Therefore, the image forming apparatus 1 can be downsized.

  A toner replenishing port 444a for taking in toner is formed above the first stirring space 438a at one end of the developing container 433a in the axial direction (first direction) of the photosensitive drum 41a. Further, the photosensitive drum 41a corresponding to the developing roller 432a is located on the first stirring space 438a side of the developing roller 432a. The toner cartridge 71 is positioned above the corresponding toner supply port 444a, and is opposed to the corresponding developing roller 432a and the photosensitive drum 41a in the first direction, and is connected to the corresponding toner supply port 444a.

  Thus, the toner can be smoothly supplied from the toner cartridge 71 to the toner supply port 444a. Further, since the positions of the developing roller 432a and the photosensitive drum 41a and the toner cartridge 71 are not shifted when viewed from the first direction, the four first to fourth image forming units 31 to 34 are arranged side by side. Even in this case, the area occupied in the front-rear direction of the image forming apparatus 1 in the entire four first to fourth image forming units 31 to 34 and the toner cartridges 71 to 74 can be reduced. That is, space saving can be achieved.

  Further, when viewed from above, the projection region of the developing roller 432a is included in the projection region of the developing container 433a. Therefore, the size of the area occupied by the developing device 43a in the front-rear direction (second direction) of the image forming apparatus 1 is the size of the area occupied by the developing container 433a in the front-rear direction (second direction) of the image forming apparatus 1. The size in the second direction can be further reduced.

  Further, when viewed from the first direction, the projection areas of the toner cartridges 71 to 74 include the projection areas of the developing roller and the photosensitive drum corresponding to the toner cartridge. Thereby, a sufficient amount of toner can be secured in each of the toner cartridges 71 to 74.

  The developer is supplied from the second stirring space 439a of the developing container 433a to the developing roller 432a, and the first conveying member 442a stirs the toner and developer supplied from the toner supply port 444a in the first stirring space 438a. While transporting to the second stirring space 439a. As a result, in the first agitation space 438a, sufficient frictional charging property can be imparted to the toner replenished from the toner replenishing port 444a, and the toner can be supplied from the second agitation space 439a to the developing roller. As a result, the chargeability of the toner supplied to the developing roller 432a becomes uniform, and image quality deterioration can be prevented. For example, toner scattering and background fog from the developing devices 43a to 43d can be prevented.

  Further, the toner supply port 444 a and the toner cartridge 71 are located between the frame 85 of the image forming main body device 2 and the side opening / closing door 101 which is a part of the casing of the image forming main body device 2. Thus, the toner cartridges 71 to 74 can be arranged by effectively using the space existing in the image forming main body device 2 (image forming device 1), and a space-saving and compact image forming device can be provided.

[Additional Notes]
An image forming apparatus according to another aspect of the present invention is an image forming apparatus including a plurality of image forming units that have a photosensitive drum and that form toner images of different colors on the photosensitive drum. The plurality of image forming units are arranged side by side along a second direction which is a horizontal direction perpendicular to the first direction, where the axial direction of the photosensitive drum is the first direction. Each of the units includes a developing device that supplies toner onto the photosensitive drum, and the developing device includes a developing roller having an axis parallel to the first direction, and a partition member along the axial direction of the developing roller. A developer container having a first agitation space and a second agitation space for accommodating a developer containing toner, which are two agitation spaces partitioned by the first and second agitation spaces; and the developer by being installed in the first agitation space and rotating A first conveying member for stirring and conveying A second conveying member that is installed in the second agitating space and rotates and agitates and conveys the developer, and the developing roller is disposed on the developing container, and when viewed from above, the developing roller Is positioned between the rotation axis of the first conveyance member and the rotation axis of the second conveyance member, and at one end of the developer container in the first direction, the toner is located above the first agitation space. And a photosensitive drum corresponding to the developing roller is located on the first stirring space side of the developing roller. The image forming apparatus includes the plurality of image forming units. A toner cartridge corresponding to each of the toner cartridges, the toner cartridge being positioned above the corresponding toner supply port, facing the corresponding developing roller and the photosensitive drum in the first direction, and corresponding toner. Characterized in that it is connected to the supply port.

  According to said structure, the axis | shaft of a developing roller is located between the rotating shaft of a 1st conveying member, and the rotating shaft of a 2nd conveying member. Therefore, the size of the area occupied by the developing device in the second direction can be reduced. As a result, when a plurality of image forming units are arranged side by side, the area occupied by the plurality of image forming units in the second direction can be reduced, and the image forming apparatus can be downsized.

  The toner cartridge is positioned above the corresponding toner supply port, and is opposed to the corresponding developing roller and the photosensitive drum in the first direction, and is connected to the corresponding toner supply port. Thereby, the toner can be smoothly supplied from the toner cartridge to the toner supply port. In addition, since the positions of the developing roller and the photosensitive drum and the toner cartridge are not shifted when viewed from the first direction, the plurality of image forming units and the toner are arranged even when the plurality of image forming units are arranged side by side. The area occupied in the second direction in the entire cartridge can be reduced. That is, space saving can be achieved.

  Furthermore, in the image forming apparatus according to one aspect of the present invention, it is preferable that the projection region of the developing roller is included in the projection region of the developer container when viewed from above.

  According to said structure, the magnitude | size of the area | region which a developing device occupies to a 2nd direction can be made still smaller.

  Furthermore, in the image forming apparatus according to an aspect of the present invention, when viewed from the first direction, the projection area of the developing roller and the photosensitive drum corresponding to the toner cartridge are included in the projection area of the toner cartridge. It is preferably included. Thereby, a sufficient amount of toner can be secured in each toner cartridge.

  Furthermore, in the image forming apparatus according to one aspect of the present invention, it is preferable that the developer is supplied to the developing roller from the second stirring space of the developing container. The first conveying member preferably conveys the toner and developer supplied from the toner replenishing port to the second agitating space while agitating in the first agitating space.

  Thereby, in the first agitation space, the toner replenished from the toner replenishing port can be given sufficient triboelectric charging property, and the toner can be supplied from the second agitation space to the developing roller. As a result, the chargeability of the toner supplied to the developing roller becomes uniform, and image quality deterioration can be prevented.

  Furthermore, in the image forming apparatus according to an aspect of the present invention, it is preferable that the toner supply port and the toner cartridge are located between the frame of the image forming apparatus and the housing of the image forming apparatus. Accordingly, the toner cartridge can be arranged by effectively using the space existing in the image forming apparatus, and a space-saving and compact image forming apparatus can be provided.

  The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments. Is also included in the technical scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 2 Image forming main body apparatus 3 Automatic document conveying apparatus 11 Process unit 31 1st image forming part 32 2nd image forming part 33 3rd image forming part 34 4th image forming part 41a-41d Photosensitive drum 43a-43d Developing devices 65 to 68 Cartridge mounting portions 71 to 74 Toner cartridge 85 Frame 101 Side opening / closing doors 431a to 431d Toner intake portion 432a Developing roller 433a Developer container 435a Tank body portion 436a Cover member 437a Partition member 438a First stirring space 439a Second Stirring space 442a First conveying member 443a Second conveying member 444a Toner supply port 445a Opening portion

Claims (8)

An image forming apparatus including an image forming unit that forms a toner image on a photosensitive drum,
The image forming unit includes a developing device that supplies toner onto the photosensitive drum,
The developing device includes a developing roller having an axis parallel to a first direction which is an axial direction of the photosensitive drum, and two stirring spaces partitioned by a partition member along the axial direction of the developing roller. A developer container having a first agitating space and a second agitating space containing developer, a first conveying member installed in the first agitating space and rotating and agitating and conveying the developer; A second conveying member that is installed in the agitating space and rotates to convey the developer by stirring;
The developing roller is disposed on the developing container, and when viewed from above, the shaft of the developing roller is located between the rotating shaft of the first conveying member and the rotating shaft of the second conveying member. ,
A toner replenishing port for taking in the toner is formed above the first stirring space at one end of the developing container in the first direction,
The image forming apparatus, wherein the photosensitive drum is positioned on the first stirring space side of the developing roller. A toner cartridge for supplying toner to the developer container;
2. The toner cartridge according to claim 1, wherein the toner cartridge is located above the toner replenishing port, is opposed to the developing roller and the photosensitive drum in the first direction, and is connected to the toner replenishing port. The image forming apparatus described.   The image forming apparatus according to claim 1, wherein a center of the shaft of the developing roller is located on the second stirring space side.   4. The image forming apparatus according to claim 1, wherein when viewed from above, the projection region of the developing roller is included in the projection region of the developer container. 5.   The image forming apparatus according to claim 2, wherein when viewed from the first direction, the projection area of the toner cartridge includes the projection area of the developing roller and the photosensitive drum.   The image forming apparatus according to claim 1, wherein a developer is supplied to the developing roller from the second stirring space of the developing container.   7. The first conveying member according to claim 1, wherein the first conveying member conveys toner and developer supplied from the toner replenishing port to the second agitating space while agitating in the first agitating space. The image forming apparatus according to claim 1.   The image forming apparatus according to claim 2, wherein the toner supply port and the toner cartridge are located between a frame of the image forming apparatus and a housing of the image forming apparatus.