Patent ID: 6922017

Claim:
An infrared lamp comprising: a carbon-based heating element obtained by the process comprising: firing a mixture of a carbon composition having compactibility and a carbon yield of substantially nonzero after firing and at least one kind of metallic or semi-metallic compound to form a carbon-based heating element and reheating said carbon-based heating element in a vacuum, to set the change rate of the electric specific resistance of said carbon-based heating element at a high temperature in lit state with respect to electric specific resistance at a normal temperature in unlit state in the range from −20% to +20% lead wires electrically connected to current passing portions of said carbon-based heating element via cylindrical connection members composed of a carbon-based substance having an inherent resistance smaller than that of said carbon-based heating element and larger than that of said lead wires, and a sealed quartz glass tube filled with a gas and accommodating said carbon-based heating element so that the ends of said lead wires extend outside said sealed quartz glass tube.