LENS WITH DEW CONDENSATION PREVENTIVE HEATER

PURPOSE:To reduce the contamination of the lens due to dew condensation, by vapor-depositing a conductor which has large electric resistance on the flank of the lens except part of the outer periphery and connecting electric good conductors to coupling parts formed on both sides of the conductor. CONSTITUTION:The conductor 2 which has the large electric resistance is vapor- deposited except on part of the outer periphery of the lens 1 so as to form the coupling parts 4 where the electric good conductors 3 are coupled. The electric good conductors 4 are connected to the coupling parts 4 and the opposite-side terminals of the electric good conductors 3 are assembled as terminal parts 3a and 3b. A current is supplied between the terminals parts 3a and 3b to make the conductor 2 which has the large electric resistance generate heat, which is radiated to the lens 1. Consequently, dew condensation on the surface of the lens is precluded to minimize the stain of the lens as much as possible.