Patent ID: 9217970
Filing Date: 2015-12-22
Classification: G03G

Abstract:
1. A heater for a fixing device, comprising: a glass substrate made of an alkali-free glass containing no alkali metal oxide, the glass substrate having a first softening point and a first thermal expansion coefficient; a heating element disposed on the glass substrate; a plurality of electrode patterns disposed on the glass substrate and connected to the heating element; a first protective layer disposed on the heating element and the electrode patterns, the first protective layer being formed by firing a first mixture containing a first glass powder and a first filler, the first glass powder containing no alkali metal oxide and containing a material that reduces a softening point of the first protective layer to a second softening point lower than the first softening point, the first filler having a second thermal expansion coefficient smaller than the first thermal expansion coefficient; and a second protective layer disposed on the first protective layer, the second protective layer being made from a second mixture not containing the first filler.