Claims
- 1. A plastic multifocal point spherical lens comprising a unitary structure of
- (A) a first synthetic resin layer having a fixed refractive index,
- (B) a second synthetic resin layer having a substantially fixed refractive index different from the refractive index of the first synthetic resin layer and
- (C) a third synthetic resin layer existing between the first synthetic resin layer and the second synthetic resin layer and having a refractive index gradient varying continuously from the refractive index of the first synthetic resin layer to that of the second synthetic resin layer,
- part of the second synthetic resin layer and part of the third synthetic resin layer together being recessed into the first synthetic resin layer, and the second synthetic resin layer being thicker at the recessed part than the rest, said recessed part having either a spherical surface or a parabolic surface.
- 2. The lens of claim 1 wherein said first, second, and third synthetic resin layers are discrete layers.
Priority Claims (1)
Number |
Date |
Country |
Kind |
61-137295 |
Jun 1986 |
JPX |
|
Parent Case Info
This application is a continuation of U.S. Pat. Ser. No. 07/061,592 filed on June 15, 1987, and now abandoned.
US Referenced Citations (3)
Number |
Name |
Date |
Kind |
3485556 |
Naujokas |
Dec 1969 |
|
4208362 |
Deichert et al. |
Jun 1980 |
|
4701288 |
Cook et al. |
Oct 1987 |
|
Foreign Referenced Citations (2)
Number |
Date |
Country |
74501 |
Apr 1984 |
JPX |
1029766 |
May 1966 |
GBX |
Continuations (1)
|
Number |
Date |
Country |
Parent |
61592 |
Jun 1987 |
|