Vehicle mirrors having convex curvatures and methods of making same

• US 5,980,050 A
• Filed: 06/02/1997
• Issued: 11/09/1999
• Est. Priority Date: 11/30/1995
• Status: Expired due to Fees

• Current Assignee: Multivex Mirror Co.
• Original Assignee: Multivex Mirror Co.
• Inventors: McCord, Robert C.
• Primary Examiner(s): Spyrou, Cassandra
• Assistant Examiner(s): Robinson, Mark A.
• Application Number:
  US08/849,260
• Time in Patent Office: 890 Days
• Field of Search: 359/864, 359/868, 359/869, 359/871, 359/866, 248/475.1, 248/479
• US Class Current: 359/868
• CPC Class Codes: B60R 1/082 using a single wide field mirror or an association of rigidly connected mirrors

Abstract

A vehicle mirror, and a mold for making same, each includes a portion of the viewing surface wherein the field angle increases at an increasing rate as the observer'"'"'s eye travels outward across the mirror, and another portion wherein the field angle increases at a decreasing rate as the observer'"'"'s eye travels across the mirror surface. In one embodiment, the mirror includes a primary viewing area (16) nearest to the observer (14) having a spherical convex surface, a secondary viewing area (18) somewhat farther from the observer, having an aspherical convex surface wherein the field angle increases at an increasing rate, and a tertiary viewing area (20) still farther outward, having an aspherical convex curvature wherein the field angle increases at a decreasing rate.

Claims

1. A vehicle mirror for mounting on a vehicle in a selected position relative to an observation point within the vehicle, the mirror having a viewing surface including a portion having a curvature expressed substantially in accordance with the following incremental field angular relationships:

space="preserve" listing-type="equation">Δ

δ

.sub.n =(Δ

δ

.sub.(n-1)){1-[h'"'"'+(n'"'"'/N'"'"')(2X'"'"'-2h'"'"')]}

in which n defines a selected point along a substantially radial line extending from a selected focal design starting point on the mirror'"'"'s surface, (n-1) defines the point immediately preceding n, δ

_n defines the accumulated field angle from the starting point for the surface to n, Δ

δ

_n defines the incremental field angle between n and (n-1), n'"'"' defines a selected point along the radial line in the portion, N'"'"' represents the total iterations across the portion, X'"'"' represent a constant factor controlling optical development across the portion, chosen to produce a desired total field of view across the surface, h'"'"' is a factor having a value between zero and 2X'"'"', chosen to control optical distortion across the portion.

2. The mirror of claim 1 wherein the viewing surface further includes a generally flat primary viewing surface, a generally aspherical convex secondary viewing surface adjacent the primary viewing surface having a border merging substantially tangentially into the primary viewing surface and extending generally outwardly from the focal design starting point, wherein the field angle increases at an increasing rate, and wherein the portion defines a generally aspherical convex tertiary viewing surface adjacent the secondary viewing surface, having a border merging substantially tangentially into the secondary viewing surface and extending generally outwardly from the focal design starting point, wherein the field angle increases at a decreasing rate as the tertiary viewing surface extends outwardly from the focal design starting point toward the edge of the mirror.

3. The mirror of claim 1 wherein the viewing surface further includes a generally spherical convex primary viewing surface, and wherein the portion defines a generally aspherical convex secondary viewing surface adjacent the primary viewing surface having a border merging substantially tangentially into the primary viewing surface and extending generally outwardly from the focal design starting point, wherein the field angle increases across the secondary viewing surface at a decreasing rate as the secondary viewing surface extends outwardly from the focal design starting point toward the edge of the mirror.

4. A vehicle mirror for mounting on a vehicle in a selected position relative to an observation point within the vehicle, the mirror having a viewing surface including a generally spherical convex primary viewing surface, a generally aspherical convex secondary viewing surface adjacent the primary viewing surface having a border merging substantially tangentially into the primary viewing surface and extending generally outwardly from a selected optical design starting point, wherein the field angle increases across the secondary viewing surface at an increasing rate, and a generally aspherical convex tertiary viewing surface adjacent the secondary viewing surface having a border merging substantially tangentially into the secondary viewing surface and extending generally outwardly from the optical design starting point, wherein the field angle increases across the tertiary viewing surface at a decreasing rate as the tertiary viewing surface extends outwardly from the optical design starting point toward the edge of the mirror, the tertiary surface having a curvature expressed substantially in accordance with the following incremental field angular relationships:

space="preserve" listing-type="equation">Δ

δ

.sub.n= (Δ

δ

.sub.(n-1)){1-[h'"'"'+(n'"'"'/N'"'"')(2X'"'"'-2h'"'"')]}

in which n defines a selected point alone a substantially radial line extending from a selected optical design starting point on the mirror'"'"'s surface, (n-1) defines the point immediately preceding n, δ

_n defines the accumulated field angle from the starting point for the surface to n, Δ

δ

_n defines the incremental field anile between n and (n-1), n'"'"' defines a selected point along the radial line in the portion, N'"'"' represents the total iterations across the portion, X'"'"' represent a constant factor controlling optical development across the portion, chosen to produce a desired total field of view across the surface, h'"'"' is a factor having a value between zero and 2X'"'"', chosen to control optical distortion across the portion.

5. A vehicle mirror for mounting on a vehicle in a selected position relative to an observation point within the vehicle, the mirror having a viewing surface comprising:

a first portion of the viewing surface having a curvature expressed substantially in accordance with the following incremental field angular relationships;

space="preserve" listing-type="equation">Δ

δ

.sub.n =(Δ

δ

.sub.(n-1)){1+[h+(n/N)(2X-2H)]}

in which n defines a selected point along a substantially radial line extending from a selected optical design starting point on the mirror'"'"'s surface, (n-1) defines the point immediately preceding n;

δ

_n defines the accumulated field angle from the optical design starting point to n;

Δ

δ

_n defines the incremental field angle between n and (n-1);

N represents the total iterations across the first portion of the surface;

X represents a constant factor controlling optical development across the first portion of the surface, chosen to produce a desired total field of view across the first portion, h is a factor having a value between zero and 2X, chosen to control optical distortion across the first portion; and

a second portion, adjacent the first portion of the viewing surface, the second portion having a curvature expressed substantially in accordance with the following incremental field angular relationships;

space="preserve" listing-type="equation">Δ

δ

.sub.n =(Δ

δ

.sub.(n-1)){1-[h'"'"'+(n'"'"'/N'"'"')(2X'"'"'-2h'"'"')]}

in which, for the second portion of the surface, n'"'"' represents a selected point along the radial line in the second portion, N'"'"' represent the total iterations across the second portion of the surface, X'"'"' represents a constant factor controlling optical development across the second portion of the surface, chosen to produce a desired total field of view across the second portion of the surface, and h'"'"' is a factor having a value between zero and 2X'"'"', chosen to control optical distortion across the second portion.

6. The vehicle mirror of claim 5 wherein the viewing surface includes another portion having a generally spherical convex surface, and wherein the first portion is adjacent the spherical convex portion, having a border merging substantially tangentially into the spherical convex portion and extending generally outwardly from the optical design starting point.

7. The vehicle mirror of claim 5 wherein the viewing surface includes another portion having a generally flat surface, and wherein the first portion is adjacent the flat portion, having a border merging substantially tangentially into the flat portion and extending generally outwardly from the focal design starting point.

8. A mold for forming a vehicle mirror for mounting on a vehicle in a selected position relative to an observation point within the vehicle, the mold having a surface including a portion having a curvature expressed substantially in accordance with the following incremental reflection angular relationships:

space="preserve" listing-type="equation">Δ

δ

.sub.n =(Δ

δ

.sub.(n-1)){1-[h'"'"'+(n'"'"'/N'"'"') (2X'"'"'-2h'"'"')]}

in which n defines a selected point along a substantially radial line extending from a selected focal design starting point on the mold'"'"'s surface, (n-1) defines the point immediately preceding n, δ

_n defines the accumulated reflection angle from the starting point for the surface to n, Δ

δ

_n defines the incremental reflection angle between n and (n-1), φ

_n is the slope angle of the surface at n, with respect to the surface at the selected starting point, n'"'"' defines a selected point along the radial line in the portion, N'"'"' represents the total iterations across the portion, X'"'"' represent a basic constant factor controlling the φ

_n slope angle development in the mold at any point across the portion, chosen to produce a desired total φ

_N slope angle across the mold'"'"'s surface, h'"'"' is a factor having a value between zero and 2X'"'"', chosen to control progression of φ

_n in the mold across the portion.

9. The mold of claim 8 wherein the mold surface further includes a generally flat primary surface, a generally aspherical convex secondary surface adjacent the primary surface having a border merging substantially tangentially into the primary surface and extending generally outwardly from the focal design starting point, wherein the reflection angle increases at an increasing rate, and wherein the portion defines a generally aspherical convex tertiary surface adjacent the secondary surface, having a border merging substantially tangentially into the secondary surface and extending generally outwardly from the focal design starting point, wherein the reflection angle increases at a decreasing rate as the tertiary surface extends outwardly from the focal design starting point toward the edge of the mold.

10. A mold for forming a vehicle mirror for mounting on a vehicle in a selected position relative to an observation point within the vehicle, the mold including a generally spherical convex primary surface, a generally aspherical convex secondary surface adjacent the primary surface having a border merging substantially tangentially into the primary surface and extending generally outwardly from a selected optical design starting point, wherein the reflection angle increases across the secondary surface at an increasing rate, and a generally aspherical convex tertiary surface adjacent the secondary surface having a border merging substantially tangentially into the secondary surface and extending generally outwardly from the optical design starting point, wherein the reflection angle increases across the tertiary surface at a decreasing rate as the tertiary surface extends outwardly from the optical design starting point toward the edge of the mold having a curvature expressed substantially in accordance with the following incremental reflection angular relationships:

space="preserve" listing-type="equation">Δ

δ

.sub.n =(Δ

δ

.sub.(n-1)){1-[h'"'"'+(n'"'"'/N'"'"')(2X'"'"'-2h'"'"')]}

in which n defines a selected point along a substantially radial line extending from a selected optical design starting point on the mold'"'"'s surface, (n-1) defines the point immediately preceding n, δ

_n defines the accumulated reflection angle from the starting point for the surface to n, Δ

δ

_n defines the incremental reflection angle between n and (n-1), φ

_n is the slope angle of the surface at n, with respect to the surface at the selected starting point, n'"'"' defines a selected point along the radial line in the portion, N'"'"' represents the total iterations across the portion, X'"'"' represent a basic constant factor controlling the φ

_n slope anile development in the mold at any point across the portion, chosen to produce a desired total φ

_N slope angle across the mold'"'"'s surface, h'"'"' is a factor having a value between zero and 2X'"'"', chosen to control progression of φ

_n in the mold across the portion.

11. A mold for forming a vehicle mirror for mounting on a vehicle in a selected position relative to an observation point within the vehicle, the mold having a surface comprising:

a first portion of the surface having a curvature expressed substantially in accordance with the following incremental reflection angular relationships;

space="preserve" listing-type="equation">Δ

δ

.sub.n (Δ

δ

.sub.(n-1)){1+[h+(n/N)(2X-2h)]}

in which n defines a selected point along a substantially radial line extending from a selected optical design point on the mold'"'"'s surface, (n-1) defines the point immediately preceding n;

δ

_n defines the accumulated reflection angle from the optical design starting point to n;

Δ

δ

_n defines the incremental reflection angle between n and (n-1);

φ

_n is the slope angle of the surface at n, with respect to the surface at the selected starting point N represents the total iterations across the first portion of the surface;

X represents a basic constant factor controlling the φ

_n slope angle development in the mold at any point across the first portion of the surface, chosen to produce a desired total φ

_N slope angle in the mold across the first portion, h is a factor having a value between zero and 2X, chosen to control optical distortion in the mold across the first portion; and

a second portion, adjacent the first portion of the surface, the second portion having a curvature expressed substantially in accordance with the following incremental reflection angular relationships;

space="preserve" listing-type="equation">Δ

δ

.sub.n =(Δ

δ

.sub.(n-1)){1-[h'"'"'+(n'"'"'/N'"'"')(2X'"'"'-2h'"'"')]}

in which, for the second portion of the surface, n'"'"' represents a selected point along the radial line in the second portion, N'"'"' represent the total iterations across the second portion of the surface, X'"'"' represents a basic constant factor controlling the φ

_n slope angle development in the mold at any point across the second portion of the surface, chosen to produce a desired total φ

_N slope angle in the mold across the second portion of the surface, and h'"'"' is a factor having a value between zero and 2X'"'"', chosen to control progression of φ

_n in the mold across the second portion.

12. The mold of claim 11 wherein the surface includes another portion having a generally spherical convex surface, and wherein the first portion is adjacent the spherical convex portion, having a border merging substantially tangentially into the spherical convex portion and extending generally outwardly from the optical design starting point.

13. The mold of claim 11 wherein the surface includes another portion having a generally flat surface, and wherein the first portion is adjacent the flat portion, having a border merging substantially tangentially into the flat portion and extending generally outwardly from the focal design starting point.