Image-forming apparatus
View Patent ↗An image-forming apparatus includes: image-forming units arranged along a direction inclined at an acute angle relative to a horizontal direction, each of the image-forming units forming an image with developer; developer-containing units positioned above the image-forming units and arranged along the horizontal direction or along a direction inclined relative to the horizontal direction at an angle smaller than the acute angle; and developer conveyance paths that connect the image-forming units to respective developer-containing units, each developer conveyance path having a tubular passage that defines a space through which the developer contained in the developer-containing unit is conveyed to the image-forming unit, wherein the tubular passage of a developer conveyance path connected to an image-forming unit located at a position higher than that of another image-forming unit has a vertically extending portion shorter than that of the tubular passage of a developer conveyance path connected to the another image-forming unit.
1. An image-forming apparatus comprising:
a plurality of image-forming units arranged along a direction inclined at an acute angle with respect to a horizontal direction, each of the plurality of image-forming units forming an image with developer;
a plurality of developer-containing units positioned above the plurality of image-forming units and arranged along the horizontal direction or along a direction inclined with respect to the horizontal direction at an angle smaller than the acute angle, each of the plurality of developer-containing units containing the developer supplied to an associated one of the plurality of image-forming units; and
a plurality of developer conveyance paths that connect the plurality of image-forming units to respective developer-containing units, each developer conveyance path having a tubular passage that defines a space through which the developer contained in the associated developer-containing unit is conveyed to the associated image-forming unit, wherein the tubular passage of a developer conveyance path connected to an image-forming unit located at a position higher than that of another image-forming unit has a vertically extending portion shorter than that of the tubular passage of a developer conveyance path connected to the another image-forming unit.
2. The image-forming apparatus according to claim 1 , wherein a developer conveyance path connected to one of the plurality of image-forming units that is positioned highest has only a tubular passage that extends in a direction perpendicular to a vertical direction, and each of the other developer conveyance paths has a first tubular passage that extends in a direction perpendicular to the vertical direction and a second tubular passage that extends in the vertical direction.
3. The image-forming apparatus according to claim 2 , wherein the tubular passage of the developer conveyance path connected to the highest positioned image-forming unit has a shape different from that of the first tubular passage of each of the other developer conveyance paths.
4. The image-forming apparatus according to claim 2 , wherein
the tubular passage of the developer conveyance path connected to the highest positioned image-forming unit and the first tubular passage of each of the other developer conveyance paths are each provided with a conveying member that conveys developer, and
the conveying member provided in the tubular passage of the developer conveyance path connected to the highest positioned image-forming unit has a shape different from that of the conveying member provided in the first tubular passage of each of the other developer conveyance paths.
5. The image-forming apparatus according to claim 2 , wherein the tubular passage of the developer conveyance path connected to the highest positioned image-forming unit has a small diameter portion at a developer inlet side of the tubular passage and a large diameter portion at a developer outlet side of the tubular passage.
6. The image-forming apparatus according to claim 2 , wherein
the first tubular passage of each of the other developer conveyance paths is provided with a conveying member that conveys developer, the conveying member having a shaft and vanes arranged on the shaft in a helical manner, and
the shaft has a small diameter section at a developer inlet side of the first tubular passage and a large diameter section at a developer outlet side of the first tubular passage.
7. The image-forming apparatus according to claim 2 , wherein
the tubular passage of the developer conveyance path connected to the highest positioned image-forming unit and the first tubular passage of each of the other developer conveyance paths are each provided with a conveying member that is rotated to convey developer, and
a number of rotations per unit time of the conveying member provided in the tubular passage of the developer conveyance path connected to the highest positioned image-forming unit is greater than a number of rotations per unit time of the conveying member provided in the first tubular passage of each of the other developer conveyance paths.
8. The image-forming apparatus according to claim 2 , wherein
the tubular passage of the developer conveyance path connected to the highest positioned image-forming unit and the first tubular passage of each of the other developer conveyance paths are each provided with a conveying member that is rotated to convey developer, and
a period in which the conveying member provided in the tubular passage of the developer conveyance path connected to the highest positioned image-forming unit is rotated is longer than a period in which the conveying member provided in the first tubular passage of each of the other developer conveyance paths is rotated.
9. The image-forming apparatus according to claim 1 , wherein a length of the vertically extending portion of the tubular passage of a developer conveyance path connected to one of the plurality of image-forming units that is positioned highest is zero.