Image forming apparatus

• US 20060120748A1
• Filed: 11/14/2005
• Published: 06/08/2006
• Est. Priority Date: 11/15/2004
• Status: Active Grant

• Current Assignee: Ricoh Company Limited
• Original Assignee: Ricoh Company Limited
• Inventors: Takehara, Kenichi, Iijima, Yasuaki, Takigawa, Junya, Suga, Tomoaki
• Granted Patent: US 7,400,842 B2
• Time in Patent Office: Days
• US Class Current: 399/92
• CPC Class Codes: G03G 15/0194 primary transfer to the final recording medium G03G15/0184 takes precedence
• CPC Class Codes: G03G 21/206 Conducting air through the machine, e.g. for cooling, filtering, removing gases like ozone
• CPC Class Codes: G03G 2221/1678 Frame structures
• CPC Class Codes: G03G 2221/18 Cartridge systems

Abstract

Heat exhaust holes are provided in a unit frame at positions just above respective imaging units. An exhaust fan causes air heated at developing elements to be exhausted outside an apparatus via heat exhaust ducts and a common duct. The heat exhaust holes are formed in different sizes depending on a position of the imaging unit. The closer the position of the imaging unit is, the larger the heat exhaust hole provided above the imaging unit is.

Claims

1. An image forming apparatus comprising:

a plurality of imaging units, each of which includes an image carrier and a developing device, the imaging units detachably arranged in a main unit of the image forming apparatus;

an optical writing device configured to scan respective light beams emitted from a light source toward respective image carriers, and to perform optical writing on the image carriers;

a heat exhaust duct provided for each of the imaging units and arranged between the optical writing device and each of the imaging units; and

an exhaust fan arranged on a side opposite to a side from which the imaging units are attached or detached to and from the main unit, and configured to cause air heated at the imaging units to be exhausted outside the main unit via the heat exhaust ducts.

2. The image forming apparatus according to claim 1, further comprising a common duct arranged on the side opposite to the side from which the imaging units are attached and detached to and from the main unit, and configured to communicate with each of the heat exhaust ducts, wherein

the exhaust fan is arranged in the common duct to cause the heated air to be exhausted outside the main unit via the heat exhaust ducts and the common duct.

3. The image forming apparatus according to claim 1, further comprising:

a frame member arranged just above the imaging units between the optical writing device and the imaging units to support the optical writing device; and

a plurality of heat exhaust openings arranged in the frame member, each of the heat exhaust openings arranged at a position corresponding to each of the imaging units, to introduce heated air into respective heat exhaust ducts, wherein

the heat exhaust openings are arranged in different sizes depending on the position such that the closer a position of the imaging unit is to a heat source, the larger a size of a heat exhaust opening arranged at a position corresponding to the imaging unit is.

4. The image forming apparatus according to claim 3, wherein the heat source includes a fixing unit that is used to fix an image.

5. The image forming apparatus according to claim 1, wherein the heat exhaust duct is configured to have a different capacity depending on a position such that the closer a position of the imaging unit is to a heat source, the larger a capacity of the heat exhaust duct provided for the imaging unit is.

6. The image forming apparatus according to claim 5, wherein the heat source includes a fixing unit that is used to fix an image.

7. The image forming apparatus according to claim 3, wherein the heat exhaust openings are arranged in different sizes depending on the position such that the farther a position of the imaging unit is from the exhaust fan, the larger a size of a heat exhaust opening arranged at a position corresponding to the imaging unit is.

8. The image forming apparatus according to claim 3, wherein the heat exhaust duct is configured to have a different capacity such that the farther a position of the imaging unit is from the exhaust fun, the larger a capacity of a heat exhaust duct provided for the imaging unit is.

9. The image forming apparatus according to claim 3, further comprising a fitting unit configured to connect the heat exhaust duct and the frame member.

10. The image forming apparatus according to claim 9, wherein the fitting unit includes

a receiving member, and

a fitting member configured to fit in the receiving member, wherein

the receiving member is arranged in any one of the heat exhaust duct and the frame member, and the fitting member is arranged in the other one of the heat exhaust duct and the frame member.

11. The image forming apparatus according to claim 10, wherein at least one of the receiving member and the fitting member is formed in a tapered shape.

12. The image forming apparatus according to claim 9, wherein the fitting unit is configured to connect the heat exhaust duct and the frame portion as the heat exhaust duct is moved from a side of the main unit toward an opposite side to the side.

13. The image forming apparatus according to claim 3, further comprising an elastic member arranged between the heat exhaust duct and the frame member.

14. The image forming apparatus according to claim 2, further comprising a positioning member provided on the heat exhaust duct and configured to engage with the common duct.

15. The image forming apparatus according to claim 14, wherein the common duct is configured to press the heat exhaust duct from the above.

16. The image forming apparatus according to claim 2, wherein the common duct is arranged such that the common duct does not overlap with the imaging units in a vertical direction.

17. The image forming apparatus according to claim 1, wherein a sectional shape of the heat exhaust duct in a direction of the normal to the image carrier is set such that a length thereof in a horizontal direction is larger than a length thereof in a vertical direction.

18. The image forming apparatus according to claim 3, wherein the frame member includes an exposure opening through which the light beams from the optical writing device pass.

19. The image forming apparatus according to claim 18, wherein the heat exhaust duct is mounted on the frame member through foamed plastic.

20. The image forming apparatus according to claim 18, wherein atmospheric pressure inside the heat exhaust duct is lower than atmospheric pressure around the exposure opening.

21. The image forming apparatus according to claim 1, wherein the heat exhaust duct is arranged at a position where the heat exhaust duct does not block the light beams from the optical writing device.