HEATED REAR-VIEW MIRROR
First Claim
1. A mirror capable of being heated comprising a non-conducting base, a reflective resistance element said element being a nickel-chromium alloy resistance film covering continuously a major portion of at least one side of said base, said film having a low total resistance and reduced reflectivity, at least two conducting contact areas on said resistance film, said contact areas being in electrical connection with means for supplying electrical power to said resistance film so as to produce a heated surface.
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Accused Products
Abstract
A heated rear-view mirror for use on the exterior of automotive vehicles is fabricated by sputtering or evaporating a Nichrome V resistance film onto a glass surface and electrically connecting the film to an automotive battery, so that when the ignition switch is turned on, the current from the automotive battery heats the resistance film enough to defrost the outside mirror. A thermostat may be used in the above system so that the mirror is heated only when necessary. The Nichrome V film serves two main purposes, first, as a heating source and second, as a low-glare mirrored surface for the system.
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Citations
8 Claims
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1. A mirror capable of being heated comprising a non-conducting base, a reflective resistance element said element being a nickel-chromium alloy resistance film covering continuously a major portion of at least one side of said base, said film having a low total resistance and reduced reflectivity, at least two conducting contact areas on said resistance film, said contact areas being in electrical connection with means for supplying electrical power to said resistance film so as to produce a heated surface.
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2. The mirror of claim 1 wherein said contact areas are copper film deposits.
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3. The mirror of claim 1 having a thermostat in electrical connection with said resistance film, with said power means and with a switch between said power means and said contact areas, said thermostat being actuated at a particular temperature or below same, causing current to flow through said resistance film.
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4. The mirror of claim 3 wherein said thermostat is a positive temperature coefficient of resistivity ceramic.
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5. The mirror of claim 3 wherein said resistance film is radially graded so that the thickest portion thereof is in the center oF the non-conducting base.
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6. The mirror of claim 3 wherein said non-conducting base is glass.
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7. The mirror of claim 5 wherein one of said contact areas is a copper film deposit in the center of the resistance film, and the other contact area is a copper film around the outer surface of said resistance film.
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8. The mirror of claim 6 wherein said mirror is located on an exterior portion of an automotive vehicle, and said power means and said switch are located within said automotive vehicle.
Specification