Heated automobile mirror

DETAILED DESCRIPTION We claim: 1.
A defogging mirror unit comprises a plate of thermally and electrically conductive metal material formed to provide a recess at one side of the plate, a self-regulating electrical resistance heater of a material of positive temperature coefficient of resistivity having one side mounted in electrically and thermally conducting relation to said one side of the plate inside the recess, contact means for electrically connecting the other side of the heater to a power source for energizing the heater to self-heat and stabilize at a relatively high self-regulated heater temperature, and a glass reflecting member disposed over the plate recess enclosing the heater in the recess so that heat from the heater is distributed to the glass reflecting member for defogging the member, characterized in that, a first part of the plate mounts the heater thereon and forms a central bottom portion of the recess having a first selected spacing from the glass reflecting member for heating a portion of the member overlying the first plate part to a selected temperature, at least one additional plate part forms at least one additional recessed bottom portion surrounding the central recess bottom portion having relatively lesser spacing from the glass reflecting member for heating portions of the member overlying each said additional plate part to corresponding temperature, and peripheral parts of the plate disposed around said additional plate part mount marginal portions of the glass reflecting member thereon and have relatively lesser spacing from the member than the additional plate part for heating said marginal portions of the member to corresponding temperature, whereby heat is distributed to the member for heating said various portions of the member to a substantially uniform temperature.
2.
A mirror unit as set forth in claim 1 further characterized in that the reflecting member comprises a glass member having a reflecting surface formed thereon, and the heater self-regulates at a relatively high heater temperature, the spacing of the first plate part from the member being selected to maximize defogging temperature of the member while avoiding injury to the glass reflecting member under ambient temperature conditions likely to be encountered in automobile operation