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US 4,449,786 AGranted
Rearview mirror
OwnerRobert C. McCordinventor
Life of this patent
Estimating the term…
Abstract
Rearview mirrors are disclosed having a convex curvature defined by mathematical and geometrical relationships between the position of the observer, the viewed objects, and the mirror. The mathematical relationships are designed to minimize bi-ocular distortions while producing the desired field of view.
Claims33
A mirror having a viewing surface with a curvature substantially in accordance with the following mathematical relationship, expressed in incremental field angular relationships:
- .DELTA..delta..sub.n =.DELTA..delta..sub.(n-i) [1+X]
- in which (n) defines the point of interest along a substantially horizontal line of the mirror's surface, beginning at the optical design axis at which point the line of sight of an observer located substantially in the normal operator's position with respect to the mirror is reflected straight rearward with respect to the vehicle's forward direction;
- or beginning at the interface with a primary viewing surface, wherein:
- (n-1) defines the point of interest immediately preceding (n);
- .delta..sub.n defines the accumulated field angle from the optical design axis of the mirror, or from the interface with a primary viewing surface, to the point of interest (n);
- .DELTA..delta..sub.n defines the incremental field angle between (n) and (n-1);
- X is the constant factor generating a constant rate of horizontal optical distortion with respect to .DELTA..delta..sub.(n-1), which is chosen to produce a desired total field of view across the variable-radius surface, all other factors remaining unchanged;
- and .DELTA..theta. is the constant vision angle increment to which all .DELTA..delta..sub.n values are related.
5 more elements
A mirror having a viewing surface with a curvature substantially in accordance with the following mathematical relationship, expressed in incremental field angular relationships:
- .DELTA..delta..sub.n =.DELTA..delta..sub.(n-1) [1+(n/N)(2X)]
- in which (n) defines the point of interest along a substantially horizontal line of the mirror's surface, beginning at the optical design axis at which point the line of sight of an observer located substantially in the normal operator's position with respect to the mirror is reflected straight rearward with respect to the vehicle's forward direction;
- or, beginning at the interface with a primary viewing surface, wherein:
- (n-1) defines the point of interest immediately preceding (n);
- .delta..sub.n defines the accumulated field angle from the optical design axis of the mirror, or from the interface with a primary viewing surface, to the point of interest (n);
- .DELTA..delta..sub.n defines the incremental field angle between (n) and (n-1);
- N represents total iterations across the variable-radius surface;
- X is the constant factor controlling horizontal optical distortion, which is chosen to produce a desired total field of view across the variable-radius surface, all other factors remaining unchanged;
- and the (n/N) ratio generates a constantly changing rate of change of .DELTA..delta..sub.n with respect to .DELTA..delta..sub.(n-1) ;
- and .DELTA..theta. is the constant vision angle increment to which all .DELTA..delta..sub.n values are related.
7 more elements
A mirror having a viewing surface with a curvature substantially in accordance with the following mathematical relationship, expressed in incremental field angular relationships:
- .DELTA..delta..sub.n =.DELTA..delta..sub.(n-1) [1+h+(n/N)(2X-2h)]
- in which (n) defines the point of interest along a substantially horizontal line of the mirror's surface, beginning at the optical design axis at which point the line of sight of an observer located substantially in the normal operator's position with respect to the mirror is reflected straight rearward with respect to the vehicle's forward direction;
- or, beginning at the interface with a primary viewing surface, wherein:
- (n-1) defines the point of interest immediately preceding (n);
- .delta..sub.n defines the accumulated field angle from the optical design axis of the mirror, or from the interface with a primary viewing surface, to the point of interest (n);
- .DELTA..delta..sub.n defines the incremental field angle between (n) and (n-1);
- (N) represents total iterations across the variable-radius surface;
- (X) is the constant factor controlling horizontal optical distortion, which is chosen to produce a desired total field of view across the variable-radius surface, all other factors remaining unchanged;
- (h) is a value chosen between zero and (X) and becomes the initial value for the multiplying factor at the beginning of the variable-radius curve where (n=1) and is subtracted-from (2X) at the final iteration point where (n=N), thus altering the rate of change characteristics of the constantly changing multiplying factor across the variable-radius surface as well as changing its magnitude at both the beginning and ending points of said variable-radius curve;
- the (n/N) ratio generates a constantly changing rate of change of .DELTA..delta..sub.n with respect to .DELTA..delta..sub.(n-1) ;
- and .DELTA..theta. is the constant vision angle increment to which all .DELTA..delta..sub.n values are related.
8 more elements
Dependencies are inferred from the claim text.