US4426139A — Progressive addition lens

Claim 1

Independent Claim 133 words

A progressive power lens having a distance portion at the top and a reading portion at the bottom connected by a central corridor wherein the power varies in said central corridor and merges smoothly into said distance and reading portions wherein said central corridor is defined by X 2 as the height measured from the reference plane (y, Z) in mm as follows: X.sub.2 =t.sub.1 +&+t t.sub.1 =C[p(Z-3).sup.3 +qy.sup.2 (Z-3).sup.2 +ry.sup.2 (Z-3)] &=formulation of distance portion t correction term to satisfy boundary conditions with ##EQU12## n=refractive index of lens material ρ 1 and ρ 2 are principal radii of the surface defined by t 1 y=coordinate of y Z=coordinate of Z C is a constant connected with the addition of power from the distance to the reading portion in diopters 0<p≦14 q≧0 r≧8.

Claim 2

Dependent Claim 133 words

A progressive power lens having a distance portion at the top and a reading portion at the bottom connected by a central corridor wherein the power varies in said central corridor and merges smoothly into said distance and reading portions wherein said central corridor is defined by X 2 as the height measured from the reference plane (y, Z) in mm as follows: X.sub.2 =t.sub.1 +&+t t.sub.1 =C[p(Z-3).sup.3 +qy.sup.2 (Z-3).sup.2 +ry.sup.2 (Z-3)] &=formulation of distance portion t correction term to satisfy boundary conditions with ##EQU12## n=refractive index of lens material ρ 1 and ρ 2 are principal radii of the surface defined by t 1 y=coordinate of y Z=coordinate of Z C is a constant connected with the addition of power from the distance to the reading portion in diopters 0<p≦14 q≧0 r≧8.

Claim 3

Dependent Claim 47 words

The lens of claim 1 wherein the values are as follows (all other values as in claim 1): ##EQU13## add=the addition of power from the distance to the reading portion in diopters p≅11 q≅1 r≅15 ##EQU14## R D =radius of the spherical surface in the distance portion.

Claim 4

Dependent Claim 123 words

A progressive power lens having a first blending zone on each side of a central corridor and horizontally spaced therefrom by a peripheral zone, said blending zone having the formula X 2 ' is defined as the height measured from the reference plane (y, Z) in mm wherein X.sub.2 '=f.sub.1 X.sub.2 +f.sub.2 X.sub.2 " where X 2 =formulation in central corridor in mm X 2 "=formulation in peripheral zone in mm ##EQU15## y=coordinate y Z=coordinate Z ##EQU16## y b =y 2 ≦ y 1 ≦15 y 2 ≧15 2≦y 3 ≦30 -2≦Z 0 ≦5 8≦Z 1 ≦18 ##EQU17## n=refractive index of lens material ≦ C 2 ≦5 N≧0 &=formulation of distance portion V is a correction term to further influence the distortion properties.

Claim 5

Dependent Claim 123 words

A progressive power lens having a first blending zone on each side of a central corridor and horizontally spaced therefrom by a peripheral zone, said blending zone having the formula X 2 ' is defined as the height measured from the reference plane (y, Z) in mm wherein X.sub.2 '=f.sub.1 X.sub.2 +f.sub.2 X.sub.2 " where X 2 =formulation in central corridor in mm X 2 "=formulation in peripheral zone in mm ##EQU15## y=coordinate y Z=coordinate Z ##EQU16## y b =y 2 ≦ y 1 ≦15 y 2 ≧15 2≦y 3 ≦30 -2≦Z 0 ≦5 8≦Z 1 ≦18 ##EQU17## n=refractive index of lens material ≦ C 2 ≦5 N≧0 &=formulation of distance portion V is a correction term to further influence the distortion properties.

Claim 6

Dependent Claim 37 words

The lens of claim 3 wherein the values are as follows (all other values as in claim 3): y 1 ≅2.1 y 2 ≅50 y 3 ≅4.2 Z 0 ≅0 Z 1 ≅12 C 2 ≅1.22 N≅0.

Claim 7

Dependent Claim 136 words

A progressive power lens having a second blending zone on each side of the reading portion and horizontally spaced therefrom by a peripheral zone, said second blending zone having the formula X 3 ' is defined as the height measured from the reference plane (y, Z) in mm wherein X.sub.3 '=G.sub.1 X.sub.3 +G.sub.2 X.sub.3 " X 3 =formulation in reading portion in mm X 3 "=formulation in peripheral zone in mm ##EQU18## y=coordinate y Z=coordinate Z y c =y 6 +k(Z-Z 2 ) y d =y 5 ##EQU19## ≦ k≦5 2≦y 4 ≦30 y 5 ≧15 y 6 ≧2 ≦ Z 1 ≦18 Z 2 ≧8 ##EQU20## n=refractive index of lens material -≦ Z 0 ≦5 0≦C 2 ≦5 N≧0 &=formulation of distance portion V is a correction term to further influence the distortion properties W=constant.

Claim 8

Dependent Claim 136 words

A progressive power lens having a second blending zone on each side of the reading portion and horizontally spaced therefrom by a peripheral zone, said second blending zone having the formula X 3 ' is defined as the height measured from the reference plane (y, Z) in mm wherein X.sub.3 '=G.sub.1 X.sub.3 +G.sub.2 X.sub.3 " X 3 =formulation in reading portion in mm X 3 "=formulation in peripheral zone in mm ##EQU18## y=coordinate y Z=coordinate Z y c =y 6 +k(Z-Z 2 ) y d =y 5 ##EQU19## ≦ k≦5 2≦y 4 ≦30 y 5 ≧15 y 6 ≧2 ≦ Z 1 ≦18 Z 2 ≧8 ##EQU20## n=refractive index of lens material -≦ Z 0 ≦5 0≦C 2 ≦5 N≧0 &=formulation of distance portion V is a correction term to further influence the distortion properties W=constant.

Claim 9

Dependent Claim 41 words

The lens of claim 5 wherein the values are as follows (all other values as in claim 5): k≅0 y 4 ≅7 y 5 ≅50 y 6 ≅14.5 Z 1 ≅12 Z 2 ≅18 C 2 ≅1.22 Z 0 ≅0 N≅0.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1987-01-16	1987-07-18	1988-01-17	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1991-01-16	1991-07-18	1992-01-17	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1995-01-16	1995-07-18	1996-01-17	$7700.00	Window Closed / Lapsed

Progressive addition lens

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