IMAGE FORMING APPARATUS

• US 20120051813A1
• Filed: 08/23/2011
• Published: 03/01/2012
• Est. Priority Date: 08/27/2010
• Status: Abandoned Application

• Current Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Original Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Inventors: Furuyama, Yoichi
• Application Number:
  US13/215,387
• Publication Number:
  US 20120051813A1
• Time in Patent Office: Days
• US Class Current: 399/341
• CPC Class Codes: G03G 15/2064 combined with pressure
• 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

Abstract

Provided is an image forming apparatus capable of efficiently cooling a hot sheet heated by heat-fixing without causing power consumption or noise. A pair of cooling rollers 200 is disposed at the downstream of fixing device 100 in a sheet conveying direction, in which the pair of cooling rollers includes a cooling roller 201 and a driven roller 203 to convey a sheet P. In addition, a phase-change material 202 is encapsulated in the cooling roller 201, in the temperature of the material to cause a phase-change between solid and liquid is or higher than a standby temperature that is a temperature of the pair of cooling rollers in a standby state, and is lower than a glass transition temperature of toner on the sheet.

Claims

1. An image forming apparatus comprising:

a fixing portion that fixes a toner image on a sheet by heat;

a cooling roller that is provided downstream of the fixing portion in a sheet conveying direction and cools the sheet conveyed from the fixing portion; and

a phase-change material that is encapsulated in the cooling roller and has a phase-change temperature to cause a phase-change between solid and liquid being higher than a temperature inside the apparatus in a standby state, and being lower than a glass transition temperature of the toner on the sheet.

2. The image forming apparatus according to claim 1,

wherein a plurality of plate-shaped ribs is provided inside the cooling roller so as to project from an inner peripheral surface of the cooling roller and extend in an axial direction.

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

a temperature detecting portion that detects a temperature of the cooling roller;

a fan that cools the cooling roller; and

a controlling portion that drives the fan based on a detection signal from the temperature detecting portion so that the fan is driven until the temperature of the cooling roller becomes less than the phase-change temperature when it is determined that the temperature of the cooling roller becomes more than the phase-change temperature.