Condensation free mirror

• US 3,887,788 A
• Filed: 06/26/1973
• Issued: 06/03/1975
• Est. Priority Date: 10/13/1972
• Status: Expired due to Term

• Current Assignee: Richard Roy Seibel, Robert Rhea
• Original Assignee: Richard Roy Seibel, Robert Rhea
• Inventors: Seibel, Richard Roy, Rhea, Robert
• Primary Examiner(s): Albritton, C. L.
• Application Number:
  US05/373,770
• Time in Patent Office: 707 Days
• Field of Search: 219/219,202,203,543,345,522
• US Class Current: 219/219
• CPC Class Codes: A47G 1/02 Mirrors used as equipment hand, pocket, or shaving mirrors A45D42/00; optical viewing means for vehicles B60R1/00
• CPC Class Codes: G05D 23/1919 characterised by the type of controller
• CPC Class Codes: G05D 23/275 with sensing element expanding, contracting, or fusing in response to changes of temperature
• CPC Class Codes: H05B 3/845 specially adapted for reflecting surfaces, e.g. bathroom - or rearview mirrors

Abstract

An anti-condensation device for mirrors comprising a printed circuit board heating element and a means for mounting said printed circuit board heating element on the rear surface of the mirror is described. The mirror assembly herein provided with said heating element maintains the mirror viewing surface free from moisture condensation. In one embodiment of the invention the temperature of the mirror is allowed to increase at the same rate as the ambient temperature and does not require a temperature controller. In another embodiment two heat generating paths are employed to provide for faster warmup and extended life for the temperature controller. The printed circuit heating element may be of rigid composition board or flexible mylar construction.

Claims

1. A CONDENSATION FREE MIRROR ASSEMBLY COMPRISING A TRANSPARENT PLATE, A LIGHT REFLECTIVE COATING ON ONE SIDE OF SAID PLATE, AN ELECTRICALLY ENERGIZEABLE HEATING ELEMENT CONSISTING OF A PRINTED CIRCUIT BOARD CONTAINING A GROUND PATH SURROUNDING THE PERIMETER OF SAID BOARD, A SINGLE CONTINUOUS ETCHED PATH OF UNIFORM THICKNESS OF A CONDUCTOR MATERIAL SELECTED FROM THE GROUP CONSISTING OF COPPER, ALUMINUM AND NICHROME, A MEANS FOR MOUNTING SAID HEATING ELEMENT TO SAID TRANSPARENT PLATE, A MEANS FOR SUPPLYING ELECTRICAL POWDER TO SAID HEATING ELEMENT

2. The condensation free mirror assembly of claim 1 wherein said printed circuit board heating element additionally contains an aperture through which a thermal fuse suitably protrudes and contacts said plate thereby providing a means for limiting the temperature of said plate below a maximum predetermined safe level.

3. The condensation free mirror assembly of claim 1 wherein said means for mounting said heating element comprises attaching said heating element to said transparent plate with a pressure sensitive adhesive.

4. A condensation free mirror assembly comprising a transparent plate, a light reflective coating on one side of said plate, an electrically energizeable heating element consisting of a printed circuit board containing a ground path surrounding the perimeter of said board, a conductor path of high resistance consisting of a continuous etched path of uniform thickness of a conducting material selected from the group consisting of copper, aluminum and Nichrome, a conductor path of low resistance consisting of a continuous etched path of uniform thickness of a conductor material selected from the group consisting of copper, aluminum and Nichrome, a temperature control means electrically connected between said conductor paths, a means for mounting said heating element to said transparent plate, a means for supplying electrical power to said heating element whereby electrical power can be transmitted to said heating element from said electrical power means, thereby energizing said heating element, whereby said plate is heated.