Frameless interior rearview mirror assembly

An interior rearview mirror assembly for a vehicle, said interior rearview mirror assembly comprising:

• a mirror casing;
• a prismatic interior reflective element;
• wherein said prismatic interior reflective element comprises a wedge-shaped glass substrate having a first surface and a second surface and a perimeter edge about a periphery of said wedge-shaped glass substrate and extending between the first and second surfaces thereof, said wedge-shaped glass substrate having a mirror reflector established at the second surface thereof, the first surface facing a driver of a vehicle when said interior rearview mirror assembly is normally mounted in a vehicle equipped with said interior rearview mirror assembly;
• wherein a front surface of the perimeter edge provides a smooth curved transition at the perimeter edge between a perimeter region of the first surface of said wedge-shaped glass substrate and said mirror casing;
• said perimeter region circumscribing said wedge-shaped glass substrate;
• wherein the front surface of the perimeter edge is rounded by grinding and polishing to provide a rounded curved surface disposed between the first surface of said wedge-shaped glass substrate and said mirror casing;
• wherein the radius of curvature of the front surface of the perimeter edge is at least 2.5 mm;
• wherein the radius of curvature of the front surface of the perimeter edge is uniform around the perimeter of said wedge-shaped glass substrate;
• and
• wherein no portion of said mirror casing encompasses the first surface of said wedge-shaped glass substrate.

An interior rearview mirror assembly for a vehicle, said interior rearview mirror assembly comprising:

• a mirror casing;
• a mirror reflective element;
• wherein said mirror reflective element comprises a glass substrate having a first surface and a second surface and a perimeter edge about a periphery of said glass substrate and extending between the first and second surfaces thereof, wherein the first surface of said glass substrate faces a driver of a vehicle when said interior rearview mirror assembly is normally mounted in a vehicle equipped with said interior rearview mirror assembly;
• wherein said mirror casing comprises a terminal end region that circumscribes an open end of said mirror casing and terminates at a terminal end edge of said mirror casing;
• wherein said terminal end region of said mirror casing comprises a rounded end region surface curving between said terminal end edge of said mirror casing and an outer surface of a sidewall of said mirror casing;
• wherein said rounded end region surface is rounded to provide a rounded curved surface disposed between the first surface of said glass substrate and said outer surface of said sidewall of said mirror casing;
• wherein the radius of curvature of said rounded end region surface is at least 2.5 mm;
• and
• wherein said glass substrate is received at said open end of said mirror casing, and wherein no part of said mirror casing encompasses said first surface of said glass substrate.