Image fixing apparatus having image fixing roller with electrolytically colored metal core

摘要

An image fixing roller includes a core metal made of aluminum alloy and having a surface with fine recesses of 50-500 angstroms in diameter formed by providing an aluminum oxide layer on the surface of the core metal. A fluorine resin heat shrinkable tube with a shrinkage ratio of not less than 5% is wrapped directly on the core metal without use of a primer. The aluminum oxide layer and the inner surface of the core metal will be electrolytically plated with nickel so as to form a black layer.