JP6308363B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus.

  Japanese Patent Application Laid-Open No. 2004-228561 has a configuration in which a biasing member is provided in a developing device housing that houses a developing device, and the developing device is biased in a direction connecting the developing roll and the rotation shaft of the photosensitive member by the biasing member. An image forming apparatus is disclosed.

JP 2013-134356 A

  SUMMARY OF THE INVENTION An object of the present invention is to provide an image forming apparatus that achieves both prevention of spilling of replenished toner and urging of a developing roll toward a photoreceptor.

Claim 1
An image forming apparatus for forming an image composed of a toner image fixed on paper,
Equipment housing,
A photoreceptor that rotates and receives a toner image on its surface;
A developer housing in which a toner receiving port opened upward is formed on one end side in the rotation axis direction of the photosensitive member and in which a toner storage chamber for storing toner is formed, and toner in the toner storage chamber is transferred to the photosensitive member A developing roll that is transported to a developing position facing the developing roll, and a support frame that supports the developing device housing so that the developing roll can swing in a direction in which the developing roll comes into contact with and separates from the photosensitive member. A developing unit that is mounted by sliding in a direction and the developing roll is adjacent to the photoconductor and is pulled out by sliding in the opposite direction;
A toner container containing replenishment toner and disposed above the developing unit;
A toner replenishment path for guiding replenished toner in the toner container to the toner receiving port is formed, and the toner replenishment path is closed by sliding the developing unit in the reverse direction and opened by sliding in the mounting direction. A toner replenishing member provided with
Wherein a position sandwiching the developing roller between the photosensitive body and the one end side of the rotation axis direction of the photosensitive member is disposed on the other end side which is opposite, facing the developing roller to the photosensitive member A first biasing member for biasing, and
Arranged on the one end side in the rotational axis direction of the photoconductor, and urging the developing device housing in a direction of pushing up from below , the toner receiving port is pressed against the toner supply member and the developing roll is An image forming apparatus comprising a second urging member for urging the photosensitive member.

Claim 2
The first urging member is a member built in the developing unit that urges the developing device housing by applying a reaction force to the support frame;
The image forming apparatus according to claim 1, wherein the second urging member is a member that urges the developing device housing by applying a reaction force to the device housing.

  According to the image forming apparatus of the first and second aspects, both the prevention of the spilling of the replenished toner and the urging of the developing roll toward the photosensitive member can be achieved.

1 is an external perspective view of an image forming apparatus as an embodiment of the present invention. FIG. 2 is a schematic diagram showing an internal configuration of the image forming apparatus whose appearance is shown in FIG. 1. It is the perspective view which showed the state which incorporated the main component of the printer in the mounting | wearing housing | casing. It is the perspective view which showed the state which pulled out one of the developing units to the middle. It is the perspective view which showed the inside of an apparatus housing | casing. FIG. 2 is a perspective view showing an inner side of a part of the apparatus housing in a state in which the photosensitive unit and the developing unit are assembled. FIG. 7 is an enlarged perspective view of a portion of a circle R1 indicated by a broken line in FIG. FIG. 7 is an enlarged perspective view showing a portion of a circle R2 indicated by a broken line in FIG. 6 so as to look down by moving the line of sight further upward than FIG. 6. FIG. 3 is a perspective view of a set of a photoconductor unit, a developing unit, and a toner supply member when viewed from the front side of the apparatus. FIG. 3 is a perspective view of a set of a photoreceptor unit, a developing unit, and a toner replenishing member as viewed from the back side of the apparatus. FIG. 11 is a rear view of a set of a photosensitive unit, a developing unit, a toner supply member, and the like shown in FIGS. 9 and 10. FIG. 4 is an enlarged perspective view of a toner receiving port of a developing device housing and a lower end portion of a toner supply member.

  Embodiments of the present invention will be described below.

  FIG. 1 is an external perspective view of an image forming apparatus as an embodiment of the present invention.

  The image forming apparatus 1 includes a scanner 10 and a printer 20.

  FIG. 2 is a schematic diagram showing the internal configuration of the image forming apparatus whose appearance is shown in FIG.

  The printer 20 includes four image forming units 50Y, 50M, 50C, and 50K that are arranged in a row substantially horizontally. In these image forming units 50Y, 50M, 50C, and 50K, toner images are formed with toners of yellow (Y), magenta (M), cyan (C), and black (K), respectively. Here, for the description common to these image forming units 50Y, 50M, 50C, and 50K, the symbols Y, M, C, and K, which indicate the distinction of toner colors, are omitted, and are denoted as the image forming unit 50. . The same applies to other components other than the image forming unit.

  Each image forming unit 50 includes a photoreceptor 51. The photosensitive member 51 receives a driving force and rotates in the direction of arrow A to form an electrostatic latent image on the surface thereof, and further, a toner image is formed by development.

  Around each photoconductor 51 provided in each image forming unit 50, a charger 52, an exposure unit 53, a developing unit 81, a primary transfer unit 62, and a cleaner 55 are provided. Here, the primary transfer unit 62 is placed between the photoreceptor 51 and an intermediate transfer belt 61 described later. The primary transfer device 62 is an element provided not in the image forming unit 50 but in an intermediate transfer unit 60 described later.

  The charger 52 uniformly charges the surface of the photoreceptor 51.

  The exposure device 53 irradiates the uniformly charged photoconductor 51 with exposure light modulated based on the image signal, thereby forming an electrostatic latent image on the photoconductor 51.

  The developing device 81 develops the electrostatic latent image formed on the photoconductor 51 with toner of a color corresponding to each of the image forming units 50Y, 50M, 50C, and 50K, and forms a toner image on the photoconductor 51. To do.

  The primary transfer unit 62 transfers the toner image formed on the photoreceptor 51 onto an intermediate transfer belt 61 described later.

  The cleaner 55 removes residual toner and the like on the photoconductor 51 after transfer from the photoconductor 51.

  Here, in the image forming apparatus 1 of the present embodiment, in each of the image forming units 50Y, 50M, 50C, and 50K, the photoconductor 51, the charger 52, and the cleaner 55 constitute one unit. Here, this unit is referred to as a photoreceptor unit 70. The photoreceptor unit 70 corresponds to an example of the photoreceptor unit referred to in the present invention. The photosensitive unit 70 is detachably attached to the apparatus housing 90 which is a framework of the image forming apparatus 1 by sliding.

  The developing unit 81 also constitutes one unit for each of the image forming units 50Y, 50M, 50C, and 50K. Here, this unit is referred to as a developing unit 80. The developing unit 80 is also detachably attached to the apparatus housing 90 of the image forming apparatus 1 by sliding.

  The exposure unit 53 is fixed to the apparatus housing 90 in each of the image forming units 50Y, 50M, 50C, 50.

  An intermediate transfer unit 60 is disposed above the four image forming units 50. The intermediate transfer unit 60 is provided with an intermediate transfer belt 61. The intermediate transfer belt 61 is supported by a plurality of rolls such as a drive roll 63a, a driven roll 63b, and a tension roll 63c. Then, the intermediate transfer belt 61 is driven by a driving roll 63a, and an arrow moves on a circulation path including a path along the four photoconductors 51 provided in the four image forming units 50Y, 50M, 50C, and 50K. Circulately moves in the B direction.

The toner images on the respective photoreceptors 51 are transferred so as to sequentially overlap the intermediate transfer belt 61 by the action of the primary transfer unit 62. The toner image transferred onto the intermediate transfer belt 61 is conveyed to the secondary transfer position T2 by the intermediate transfer belt 61. The secondary transfer position T2 is provided with a secondary transfer unit 71, and the toner image on the intermediate transfer belt 61 has been conveyed to the secondary transfer position T2 by the action of the secondary transfer unit 71. Transferred onto the paper P. The conveyance of the paper P will be described later. The toner remaining on the intermediate transfer belt 61 after the transfer of the toner image onto the paper P is removed from the intermediate transfer belt 61 by the cleaner 64.

  Further, when the photosensitive unit 70 or the developing unit 80 is attached or removed, the intermediate transfer belt 61 is separated from all the four photosensitive members 51 by the operation of the operation lever 65 (see FIG. 3). The occurrence of scratches due to rubbing against the rust is prevented.

  A toner cartridge 23 that contains toner of each color is provided on the upper portion of the intermediate transfer unit 60. When the toner in the developing device 81 is consumed by the development, the toner is replenished to the developing device 81 from the toner cartridge 23 containing the corresponding color toner. The toner cartridge 23 is configured to be detachable. When the toner cartridge 23 is empty, the toner cartridge 23 is removed and a new toner cartridge 23 is mounted.

  One sheet P is taken out from the paper tray 21 by the pick-up roll 24, and is conveyed by the conveyance roll 25 to the timing adjustment roll 26 in the direction of arrow C on the conveyance path 201. The sheet P conveyed to the timing adjustment roll 26 reaches the secondary transfer position T2 in accordance with the timing at which the toner image on the intermediate transfer belt 61 reaches the secondary transfer position T2 by the timing adjustment roll 26. Thus, the sheet is fed toward the secondary transfer position. The sheet P sent out by the timing adjustment roll 26 receives the transfer of the toner image from the intermediate transfer belt 61 by the action of the secondary transfer unit 71 at the secondary transfer position T2. The sheet P that has received the transfer of the toner image is further conveyed in the direction of arrow D and passes through the fixing device 72. The toner image on the paper P is fixed on the paper P by being heated and pressurized by the fixing device 72. As a result, an image composed of the fixed toner image is printed on the paper P. The sheet on which the toner image has been fixed by the fixing device 72 is further conveyed by the conveyance roll 27 and is sent out from the sheet discharge outlet 29 onto the sheet discharge tray 22 by the sheet discharge roll 28.

  FIG. 3 is a perspective view showing a state in which main components of the printer are incorporated in the mounting housing. Here, in order to show the internal structure, the front cover and the like are removed.

  FIG. 4 is a perspective view showing a state in which one of the developing units is pulled out partway.

  FIG. 5 is a perspective view showing the inside of the apparatus housing.

  Further, FIG. 6 is a perspective view showing the inside of the apparatus housing in a state in which the photoconductor unit and the developing unit are incorporated, and a part of the apparatus housing is cut.

  3 to 6, the apparatus housing 90 is shown in a direction in which the lower left is the front side and the upper right is the back side.

  As shown in FIG. 5, four guide rails 91 extending in the front-rear direction are provided corresponding to each of the four image forming units 50 shown in FIG. As described above, each image forming unit 50 is provided with the photosensitive unit 70 and the developing unit 80. The photosensitive unit 70 and the developing unit 80 slide in the front-rear direction while being guided by the guide rail 91, The developing unit 80Y is pulled out of the apparatus housing 90 as shown in FIG. The drawer from the apparatus housing 90 is for maintenance such as component replacement. In order to prevent the intermediate transfer belt 61 (see FIG. 2) from sliding and scratching during this sliding, the slide operation is performed after the intermediate transfer belt 61 is separated from the photoreceptor 51 by turning the operation lever 65. Done. A waste toner tank (not shown) is placed on the front side of these image forming units 50, and the operation lever 65 stands on the front side of the waste toner tank. The removal of the waste toner tank, the photosensitive unit 70, and the development unit 80 are performed. Is in a state where it cannot be pulled out. When the operation lever 65 is rotated in a direction in which the intermediate transfer belt 61 is separated from the photoreceptor 51, the waste toner tank can be removed, and the photoreceptor unit 70 and the developing unit 80 can be pulled out. Therefore, it is ensured that the intermediate transfer belt 61 is separated from the photoconductor 51 when the photoconductor unit 70 and the developing unit 80 are pulled out.

  The developing unit 80 is also provided with an operation lever 82. The operation lever 82 is in a position that stands in front of the photosensitive unit 70. The developing unit 80 is provided with a developing roll 812 (see the developing roll 812M shown in FIG. 8) that is biased toward the photoconductor 51, and the operation lever 82 is retracted from the front surface of the photoconductor unit 50. When rotated in such a manner, the developing roll 812 is separated from the photoconductor 51, and the photoconductor unit 70 can be pulled out to the front side. The developing unit 80 is pulled out after the photosensitive unit 70 is pulled out. At the time of mounting, first, the developing unit 80 is mounted, then the photosensitive unit 70 is mounted, and the operation lever 82 is operated in a direction standing on the front surface of the photosensitive unit 70.

  Here, as shown in FIG. 5, on the back side of each guide rail 91, a drive shaft 93 and a coupling 94 projecting from the back side support plate 92 toward the near side are provided. The drive shaft 93 extends on the slide path of the photoconductor unit 70, and plays a role of transmitting a rotational driving force to the photoconductor 51 by being inserted into the photoconductor 51 when the photoconductor unit 70 is mounted. The coupling 94 protrudes on the slide path of the developing unit 80 and plays a role of transmitting driving force to the developing unit 70 by being coupled to the developing unit 70 when the developing unit 70 is mounted.

  FIG. 7 is an enlarged perspective view of a portion of a circle R1 indicated by a broken line in FIG.

  Here, FIG. 7A shows a state where the cover member 831 is attached, and FIG. 7B shows a state where the cover member 831 is removed.

  As shown in FIG. 6, the developing unit 80 includes a developing device 81 and a support frame 83 that supports the developing device 81 in a swingable manner. The cover member 831 is a member that forms part of the support frame 83. A spring member 84 is provided inside the cover member 831 as shown in FIG. The spring member 84 corresponds to an example of a first biasing member referred to in the present invention.

  The developing device 81 includes a developing device housing 811 and a developing roll 812 (see FIG. 8). The developing device casing 811 has a toner storage chamber 811a for storing toner therein. The developing roll 812 is a member that rotates while being supported by the developing device casing 811 and transports the toner in the toner storage chamber 811 a to the developing position facing the photoreceptor 51. The developing roll 812 is substantially in a side-by-side position with the photosensitive member 51 when the photosensitive unit 70 and the developing unit 80 are mounted in the apparatus housing 90. The spring member 84 </ b> Y is a member that urges the developing device casing 811 to the side of the developing roll 812 toward the photosensitive member 51 together with the developing device casing 811.

  FIG. 8 is an enlarged perspective view showing a portion of a circle R2 indicated by a broken line in FIG. 6 so that the line of sight moves further upward than FIG.

  In FIG. 8, the developing unit housing 811Y is shown for the developing unit 80Y, and the internal structure of the developing unit 81M is shown by removing the upper cover portion of the developing unit housing for the developing unit 80M.

  A developing device housing 811 constituting the developing device 81 is formed with a toner receiving port 815 that receives replenishing toner from the toner cartridge 23 (see FIG. 2). The toner received from the toner receiving port 815 into the toner storage chamber 811a formed in the developing device casing 811 is circulated in the front-rear direction while being agitated by the auger 814 disposed in the toner storage chamber 811a. Be transported. Then, the toner in the toner storage chamber 811a is conveyed to the developing position facing the photoconductor 51 by the developing roll 812, and the electrostatic latent image on the photoconductor 51 is developed with the toner as described above. Here, annular spacers 813 are provided at both ends in the longitudinal direction of the developing roll 812. The developing roll 812 is urged toward the photosensitive member 51 together with the developing device casing 811 by the above-described spring member 84 (see FIG. 7B) and another spring member 85 (see FIG. 11) described later. A spacer 813 is abutted against the photoreceptor 51. As a result, the distance between the photosensitive member 51 and the developing roll 812 is constant even during rotation, and stable development is performed.

  9 and 10 are perspective views showing a set of the photosensitive unit, the developing unit, and the toner replenishing member as seen from different directions. 9 is a perspective view when viewed from the front side of the apparatus, and FIG. 10 is a perspective view when viewed from the back side of the apparatus. However, in these drawings, the cover member 831 (see FIG. 7A) constituting the support frame 83 constituting the developing unit 80 is removed.

  The toner cartridge 23 shown in FIG. 2 contains supply toner for each color. The toner replenishing member 95 is a cylindrical member, and a toner replenishing path 951 that guides the replenishing toner in the toner cartridge 23 to a toner receiving port 815 (see FIG. 8) provided in the developing device housing 811 is formed. . The replenishing toner in the toner cartridge 23 passes through a toner replenishing path 951 formed in the toner replenishing member 95, and from a toner receiving port 815, a toner storage chamber 811a in the developing device casing 811 of the developing device 81 (see FIG. 8). ).

  Here, in FIGS. 9 and 10, in addition to the spring member 84 (see also FIG. 7B) provided on the front side of the apparatus (portion close to the front of the apparatus), the back of the developing unit 80 is also shown. Another spring member 85 provided on the side portion (portion close to the back of the apparatus) is shown. The spring member 85 corresponds to an example of a second urging member according to the present invention.

  As described above, the spring member 84 provided on the front side of the apparatus applies a reaction force to the support frame 83 constituting the developing unit 80 to urge the developing device housing 811 laterally toward the photosensitive member 51. A member incorporated in the developing unit 80. On the other hand, another spring member 85 provided on the back side of the apparatus is supported by an apparatus casing 90 (see, for example, FIG. 1), and develops by applying a reaction force to the apparatus casing 90. It is a member that urges the housing 811 upward.

  FIG. 11 is a rear view of a set of the photosensitive unit, the developing unit, the toner supply member, and the like shown in FIGS.

  As described above, the developing unit 80 includes the support frame 83 and the developing device 81 that is swingably supported by the support frame 83. The developing device 81 includes a developing device housing 811 in which a toner storage chamber 811a (see FIG. 8) is formed, and a developing roll 812 that is rotatably supported by the developing device housing 811. The developing roll 812 is disposed at a position substantially side by side with the photoconductor 51 constituting the photoconductor unit 70.

  Here, the developing device 81 is supported by the support frame 83 so as to swing around the shaft 816. The shaft 816 is provided below the developing roll 812, and when the developing device 81 rotates around the shaft, the developing roll 812 moves in a direction to come in contact with and separate from the photosensitive member 51. The spring member 85 urges the developing device casing 811 to be pushed up on the side farther from the photosensitive unit 70 than the shaft 816 (left side in FIG. 13) in the left-right direction in FIG. Thereby, for example, a toner receiving port 815 (see FIG. 8) provided in the developing device housing 811 is pressed against the toner supply member 95 to prevent toner spillage. In addition, the spacer 813 (see FIG. 8) is photosensitive so that the developing device casing 811 rotates about the shaft 816 by pushing up the spring member 85 and the gap with the developing roll 812 is constant. It is abutted against the body 51.

  As described above, in this embodiment, the single spring member 85 realizes both the prevention of the spilling of the replenished toner and the pressing of the developing roll 812 against the photosensitive member 51. Thereby, the number of parts is reduced and the configuration is simplified as compared with the case where these roles are assigned to separate urging members.

  FIG. 12 is an enlarged perspective view of the toner receiving port of the developing device housing and the lower end portion of the toner supply member. Here, a state in which the developing unit 80 is slightly slid in the take-out direction is shown.

  An opening 952 connected to an internal toner supply path 951 (see FIG. 9) is formed at the lower end of the toner supply member 95. The toner supply member 95 is provided with a shutter 96 so that toner does not spill out from the opening 952 when the developing unit 80 is removed. The shutter 96 is a member that closes the toner supply path 951 (see FIG. 9) of the toner supply member 95 by sliding the developing unit 80 in the take-out direction and opens it by sliding the developing unit 80 in the mounting direction. . However, FIG. 12 shows the developing unit 80 in a state of being moved in the take-out direction. However, the shutter 96 is shown in a state where the developing unit 80 is attached for easy understanding. The shutter 96 is shown in the open position. When the developing unit 80 is taken out, the shutter 96 moves to a position that closes the opening 952 by the action of the spring member 97, and moves to the open position shown in FIG. 12 by the last slide in the mounting direction of the developing unit 80. To do.

  The spring member 85 that pushes up the developing device casing 811 keeps pushing the developing device housing 811 up until the shutter 96 closes the opening 952 when the developing unit 80 is taken out, so that toner spills from the opening 952. Is prevented.

  Here, an example in which the present invention is applied to the printer 20 having the form shown in FIG. 1 has been described, but the present invention can be applied to any image forming apparatus in which the developing unit is inserted and removed.

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 10 Scanner 20 Printer 30 User interface 50 Image forming part 51 Photoconductor 52 Charger 53 Exposure device 55,64 Cleaner 60 Intermediate transfer part 61 Intermediate transfer belt 65 Operation lever 70 Photosensitive unit 80 Developing unit 81 Developing unit 82 Operation lever 83 Support frame 84, 85 Spring member 90 Mounting housing 91 Guide rail 95 Toner supply member 96 Shutter 811 Developer housing 811a Toner storage chamber 812 Developing roll 813 Spacer 814 Auger 815 Toner inlet 816 Shaft 831 Cover member 951 Toner Supply path 952 Open

Claims (2)

An image forming apparatus for forming an image composed of a toner image fixed on paper,
Equipment housing,
A photoreceptor that rotates and receives a toner image on its surface;
A developer housing in which a toner receiving port opened upward is formed on one end side in the rotation axis direction of the photosensitive member and in which a toner storage chamber for storing toner is formed, and toner in the toner storage chamber is transferred to the photosensitive member A developing roll that is transported to a developing position facing the developing roll, and a support frame that supports the developing device housing so that the developing roll can swing in a direction in which the developing roll comes into contact with and separates from the photosensitive member. A developing unit that is mounted by sliding in a direction and the developing roll is adjacent to the photoconductor and is pulled out by sliding in the opposite direction;
A toner container containing replenishment toner and disposed above the developing unit;
A toner replenishment path for guiding replenished toner in the toner container to the toner receiving port is formed, and the toner replenishment path is closed by sliding the developing unit in the reverse direction and opened by sliding in the mounting direction. A toner replenishing member provided with
Wherein a position sandwiching the developing roller between the photosensitive body and the one end side of the rotation axis direction of the photosensitive member is disposed on the other end side which is opposite, facing the developing roller to the photosensitive member A first biasing member for biasing, and
Arranged on the one end side in the rotational axis direction of the photoconductor, and urging the developing device housing in a direction of pushing up from below , the toner receiving port is pressed against the toner supply member and the developing roll is An image forming apparatus comprising a second urging member for urging the photosensitive member. The first urging member is a member built in the developing unit that urges the developing device housing by applying a reaction force to the support frame;
The image forming apparatus according to claim 1, wherein the second urging member is a member that urges the developing device housing by applying a reaction force to the device housing.

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