SHEET COOLING APPARATUS AND IMAGE FORMING APPARATUS

• US 20140029995A1
• Filed: 06/28/2013
• Published: 01/30/2014
• Est. Priority Date: 07/26/2012
• Status: Active Grant

• Current Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Original Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Inventors: Okuda, Kazuhisa
• Granted Patent: US 9,625,861 B2
• Time in Patent Office: Days
• US Class Current: 399/341
• CPC Class Codes: G03G 15/2021 Plurality of separate fixing and/or cooling areas or units, two step fixing
• CPC Class Codes: G03G 15/2039 with means for controlling the fixing temperature
• CPC Class Codes: G03G 15/6573 Feeding path after the fixing point and up to the discharge tray or the finisher, e.g. special treatment of copy material to compensate for effects from the fixing
• CPC Class Codes: G03G 21/206 Conducting air through the machine, e.g. for cooling, filtering, removing gases like ozone
• CPC Class Codes: G03G 2215/00662 Decurling device
• CPC Class Codes: G03G 2221/1645 for conducting air through the machine, e.g. cooling

Abstract

There is provided a sheet cooling apparatus that cools a sheet while conveying the sheet passed passing through a fixing device for fixing an unfixed toner image formed on the sheet by heating the toner image, wherein a second suspension member is arranged so as to press a second endless belt on a circumferential face of a first cooling roller through a first endless belt, a first suspension member is arranged so as to press the first endless belt on a circumferential face of a second cooling roller through the second endless belt, and a curved sheet conveying path is formed between the first endless belt and the second endless belt.

Claims

1. A sheet cooling apparatus that cools a sheet while conveying the sheet passed through a fixing device for fixing an unfixed toner image formed on the sheet by heating the toner image, the sheet cooling apparatus comprising:

a first endless belt that is suspended on a first cooling roller and a first suspension member arranged downstream of the first cooling roller in a conveying direction; and

a second endless belt that is suspended on a second cooling roller arranged downstream of the first cooling roller in the conveying direction and a second suspension member arranged upstream of the second cooling roller in the conveying direction,

wherein the second suspension member is arranged so as to press the second endless belt on a circumferential face of the first cooling roller through the first endless belt, the first suspension member is arranged so as to press the first endless belt on a circumferential face of the second cooling roller through the second endless belt, and a curved sheet conveying path is formed between the first endless belt and the second endless belt.

2. The sheet cooling apparatus according to claim 1, wherein a plurality of the first suspension members is disposed, and at least one of the plurality of the first suspension members is pressed to the first cooling roller through the first endless belt.

3. The sheet cooling apparatus according to claim 2, wherein a suspension member disposed downstream in the conveying direction among the plurality of the first suspension members is provided to be movable so as to approach or be separated from the second cooling roller, and a nip length in a lowermost-stream portion of a contact range between the first endless belt and the second endless belt is changed in accordance with a movement of the suspension member.

4. The sheet cooling apparatus according to claim 1, wherein a plurality of the second suspension members is disposed, and at least one of the plurality of the second suspension members is pressed to the second cooling roller through the second endless belt.

5. The sheet cooling apparatus according to claim 1, wherein an inside of at least one of the first and second cooling rollers is a hollow, heat radiation fins are disposed integrally with an inner wall of the hollow, and the heat radiation fins form a spiral shape formed in directions of rotation shafts of the first and second cooling rollers so that cooling air is generated inside of the cooling roller in accordance with rotation of the cooling roller.

6. The sheet cooling apparatus according to claim 5, wherein a cooling fan that blows cooling air into inside of the cooling roller is disposed in at least one end portion of the cooling roller having the hollow in a direction of a rotation shaft, and a wind direction of the cooling air according to the rotation of the cooling roller and a wind direction of the cooling air according to the cooling fan coincide with each other.

7. The sheet cooling apparatus according to claim 5, wherein the cooling roller having the hollow includes at least one heat pipe roller supported to be rotatable for heat uniformization in the direction of the rotation shaft of the cooling roller in the hollow.

8. The sheet cooling apparatus according to claim 7, wherein the heat pipe roller contacts the inner wall of the cooling roller and is driven to rotate in accordance with the rotation of the cooling roller in a same direction.

9. The sheet cooling apparatus according to claim 1, wherein the sheet conveying path is bent in a shape of “

S”

.

10. An image forming apparatus comprising:

an image forming portion that forms a toner image on a sheet;

a fixing device that nips and conveys the sheet in a fixing nip portion between a fixing member and a pressing member and fixes an unfixed toner image formed on the sheet by heating the toner image; and

a sheet cooling apparatus that cools the sheet passed through the fixing device,

the sheet cooling apparatus comprising;

a first endless belt that is suspended on a first cooling roller and a first suspension member arranged downstream of the first cooling roller in a conveying direction; and

a second endless belt that is suspended on a second cooling roller arranged downstream of the first cooling roller in the conveying direction and a second suspension member arranged upstream of the second cooling roller in the conveying direction,

wherein the second suspension member is arranged so as to press the second endless belt on a circumferential face of the first cooling roller through the first endless belt, the first suspension member is arranged so as to press the first endless belt on a circumferential face of the second cooling roller through the second endless belt, and a curved sheet conveying path is formed between the first endless belt and the second endless belt.

11. The image forming apparatus according to claim 10, wherein a plurality of the first suspension members is disposed, and at least one of the plurality of the first suspension members is pressed to the first cooling roller through the first endless belt.

12. The image forming apparatus according to claim 11, wherein a suspension member disposed downstream in the conveying direction among the plurality of the first suspension members is provided to be movable so as to approach or be separated from the second cooling roller, and a nip length in a lowermost-stream portion of a contact range between the first endless belt and the second endless belt is changed in accordance with a movement of the suspension member.

13. The image forming apparatus according to claim 10, wherein a plurality of the second suspension members is disposed, and at least one of the plurality of the second suspension members is pressed to the second cooling roller through the second endless belt.

14. The image forming apparatus according to claim 10, wherein an inside of at least one of the first and second cooling rollers is a hollow, heat radiation fins are disposed integrally with an inner wall of the hollow, and the heat radiation fins having the protruded shape form a spiral shape formed in directions of rotation shafts of the first and second cooling rollers so that cooling air is generated inside of the cooling roller in accordance with rotation of the cooling roller.

15. The image forming apparatus according to claim 14, wherein a cooling fan that blows cooling air into inside of the cooling roller is disposed in at least one end portion of the cooling roller having the hollow in a direction of a rotation shaft, and a wind direction of the cooling air according to the rotation of the cooling roller and a wind direction of the cooling air according to the cooling fan coincide with each other.

16. The image forming apparatus according to claim 14, wherein the cooling roller having the hollow includes at least one heat pipe roller supported to be rotatable for heat uniformization in the direction of the rotation shaft of the cooling roller in the hollow.

17. The image forming apparatus according to claim 16, wherein the heat pipe roller contacts the inner wall of the cooling roller and is driven to rotate in accordance with the rotation of the cooling roller in a same direction.

18. The image forming apparatus according to claim 10, wherein the sheet conveying path is bent in a shape of “

S”

.