Image forming apparatus

Abstract

An image forming apparatus includes photoconductive drums aligned side by side for toner images in colors to be formed on peripheral surfaces thereof. A transfer belt turns while stretched over rollers for the toner images to be transferred thereon by being superimposed one another as a surface thereof abuts on the peripheral surfaces of the photoconductive drums. A transfer roller transfers the toner images from the transfer belt onto a recording sheet. The transfer belt uses the position of the transfer roller as a turning position and turns to have a first side that moves in a first direction towards the turning position while abutting the peripheral surfaces of the photoconductive drums and a second side that moves opposite to the first direction using the turning position as a starting point. A cooling mechanism cools the transfer belt by circulating taken-in outside air along a surface of the second side.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional front view used to describe the inner structure of a printer according to one embodiment of the invention.

FIG. 2 is a perspective view of an image forming unit used to describe a cooling mechanism according to the embodiment.

FIG. 3 is a perspective view schematically showing the image forming unit shown in FIG. 2 on a production basis.

FIG. 4 is a sectional front view of an image forming apparatus adopting a cooling mechanism in the prior art for a transfer belt.

Claims

1. An image forming apparatus, comprising: plural photoconductive drums aligned side by side for toner images in respective colors to be formed on peripheral surfaces thereof;a transfer belt configured to turn while being stretched over a specific number of rollers for the respective toner images to be transferred thereon by being superimposed one another as a surface thereof abuts on the peripheral surfaces of the respective photoconductive drums;a transfer roller configured to transfer the toner images having been transferred onto the surface of the transfer belt onto a recording sheet; anda cooling mechanism configured to apply cooling processing to the transfer belt using taken-in outside air,wherein:the transfer belt uses a position at which the transfer roller is disposed as a turning position and is turned to have a first side that moves in a first direction heading for the turning position while abutting on the peripheral surfaces of the respective photoconductive drums and a second side that moves in a second direction opposite to the first direction using the turning position as a starting point; andthe cooling mechanism applies the cooling processing to the transfer belt by circulating the taken-in outside air along a surface of the second side.

2. The image forming apparatus according to claim 1, wherein: the transfer belt is disposed at an upper side of the photoconductive drums.

3. The image forming apparatus according to claim 1, wherein: the cooling mechanism circulates outside air in a direction opposite to the second direction.

4. The image forming apparatus according to claim 3, wherein the cooling mechanism includes: an inlet fan provided at a downstream end in a moving direction of the second side of the transfer belt and configured to take in outside air to blow the outside air on the second side; andan exhaust fan provided at an upstream end in the moving direction of the second side.

5. The image forming apparatus according to claim 4, further comprising: a fixing portion provided at an upper position at the upstream end in the moving direction of the second side and configured to apply fixing processing by heating to the recording sheet done with transfer processing; anda heat insulating duct member provided in a space between the fixing portion and the second side and configured to shield against heat from the fixing portion by forming an air curtain inside thereof by receiving an air flow discharged from the inlet fan.