ANTI-GLARE REAR VIEW MIRROR INCORPORATING A MELTABLE THERMOPLASTIC MATERIAL

• US 3,840,292 A
• Filed: 09/04/1973
• Issued: 10/08/1974
• Est. Priority Date: 09/04/1973
• Status: Expired due to Term

• Current Assignee: Henry W. Griffin, Vaughn D. Everhart
• Original Assignee: Henry W. Griffin, Vaughn D. Everhart
• Inventors: Griffin, Henry W., Everhart, Vaughn D.
• Primary Examiner(s): Corbin, John K.
• Application Number:
  US05/394,353
• Time in Patent Office: 399 Days
• Field of Search: 350/278,279
• US Class Current: 359/604
• CPC Class Codes: B60R 1/068 using cables
• CPC Class Codes: B60R 1/088 using a cell of electrically changeable optical characteristic, e.g. liquid-crystal or electrochromic mirrors
• CPC Class Codes: G02F 1/0147 based on thermo-optic effects G02F1/132 takes precedence

Abstract

An anti-glare rear view mirror includes a meltable medium contained between a front clear glass element and a rear reflectorized glass element. The medium has a high optical transmission when melted and a lower transmission when solidified. An operator controlled heating element melts the contained medium to provide maximum transmission and reflectivity for '"'"''"'"''"'"''"'"'day'"'"''"'"''"'"''"'"' driving mode. Deenergizing the heating element allows solidification of the medium to provide a lower transmission and reflectivity for a '"'"''"'"''"'"''"'"'night'"'"''"'"''"'"''"'"' driving mode.

Claims

1. An anti-glAre rear view mirror for a motor vehicle comprising:

a mirror unit adapted to be adjustably connected to the motor vehicle, said mirror unit including a front transparent element and a rear reflective element spaced apart and defining a sealed cavity therebetween, a meltable medium in said cavity changeable between liquid and solid states upon heating thereof, said medium in one of said states having a high optical transmissivity so as to provide maximum reflectivity for the unit, said medium in the other of said states having a lower optical transmissivity to provide minimum reflectivity for the unit; and

heating means in thermal exchange relationship with said medium operable for heating the latter to change said medium between states to provide the desired reflectivity.

2. An anti-glare rear view mirror for a motor vehicle for providing the driver of the vehicle with a variable reflectivity rearward field of view comprising:

a housing adapted to be supported on the vehicle;

a mirror unit adjustably connected to the housing means including first and second mirror elements, said first element being transparent and facing said driver, said second element having a reflective coating and spaced from the driver by said first element;

a thermoplastic medium in said cavity changeable between a solid state and a liquid state by heating and cooling thereof, said medium in said liquid state having a high optical transmissivity, said medium in the solid state having a lower optical transmissivity; and

heating means in thermal exchange with said medium; and

control means for said heating means to energize said heating means for heating said medium to change said medium to the high optical transmissivity liquid state thereby providing maximum reflectivity for the unit, said heating means when deenergized permitting cooling of the medium to the lower optical transmissivity solid state thereby providing minimum reflectivity for the unit.

3. An exterior anti-glare rear mirror for a motor vehicle for providing the driver of the vehicle with a variable reflectivity rearward field of view comprising:

a housing adapted to be supported on the exterior of the vehicle and having a mirror cavity opening toward the driver;

a mirror unit located in the mirror cavity and adjustable connected to the housing, said mirror unit including a pair of glass elements;

gasket means relatively spacing the elements to define a sealed cavity therebetween, one of said elements being transparent and facing said driver, the other of said elements having a reflective coating on the surface adjacent said one element and spaced from said driver by the latter;

a meltable thermoplastic medium in said sealed cavity contacting said coating, said medium being changeable between a transluscent solid state and a transparent liquid state upon heating and cooling thereof;

a heating element carried by the mirror unit in thermal exchange with said medium operable to change said medium between states to provide the desired reflectivity for the unit; and

control means operable by the driver to energize the heating element to heat and melt the medium to said transparent liquid state for providing maximum reflectivity for the unit and to deenergize the heating element to cool and solidify the medium to said transluscent solid state for providing minimum reflectivity for the unit.