Plastic optical devices having antireflection film and mechanism for equalizing thickness of antireflection film

• US 6,250,758 B1
• Filed: 04/01/1999
• Issued: 06/26/2001
• Est. Priority Date: 05/16/1997
• Status: Expired due to Term

• Current Assignee: Hoya Corporation
• Original Assignee: Hoya Corporation
• Inventors: Kamura, Hitoshi, Kamiya, Hajime, Yoshihara, Masaaki
• Primary Examiner(s): Sugarman, Scott J.
• Application Number:
  US09/230,031
• Time in Patent Office: 817 Days
• Field of Search: 359/586, 359/587, 359/588, 359/589, 351/166, 351/163, 351/177
• US Class Current: 351/163
• CPC Class Codes: B32B 15/08 of synthetic resin
• CPC Class Codes: B32B 27/08 of synthetic resin
• CPC Class Codes: C23C 14/044 using masks to redistribute rather than totally prevent coating, e.g. producing thickness gradient
• CPC Class Codes: C23C 14/3464 using more than one target C23C14/56 takes precedence
• CPC Class Codes: C23C 14/505 for rotation of the substrates
• CPC Class Codes: G02B 1/115 Multilayers

Abstract

Plastic optical devices in which an antireflection film (13) is coated on the surface of a plastic base material (10). The antireflection film (13) is a multi-layered film which is formed by depositing a first layer (131) on the side of the plastic base material substantially by a high-refractive material and the next layer (132) by a low-refractive material, and by alternately laminating those high-refractive materials and low-refractive materials. The surface of the optical lens base material (10) has curvature and a plurality of the optical lens base materials (10) are disposed horizontally at the positions of concentric circles in a circular plate holder (26) which is placed horizontally and is rotatable. A sputtering film deposition system comprises targets (31) facing to the surfaces of the optical lens base materials (10). Thickness correcting plates function as mask members (51, 52) for regulating the difference of film thickness disposed in the direction connecting the peripheral part and the center part in the holder and between the targets (31) and the holder (26).

Claims

1. Plastic optical devices in which an antireflection film (13) is coated at least on one surface of a plastic base material (10), characterized in that said antireflection film (13) is a multi-layered film which is formed by depositing a first layer (131) on the side of said plastic base material substantially by a high-refractive material and the next layer (132) by a low-refractive material and by alternately laminating those high-refractive materials and low-refractive materials, whose dominant wavelength range is 480 to 550 nm, excitation purity range is 10 to 30% and luminous reflectance is 0.7 to 1.8%, and which has a greenish interference color.

2. The plastic optical devices of claim 1, wherein:

the thickness of said low-refractive material positioned in the intermediate area of said multi-layered film is relatively thickened so that required hardness and durability can be obtained.

3. The plastic optical devices having the antireflection film according to claim 1, characterized in that said high-refractive material is metal oxide deposited by a sputtering method by using a target made from any one of Zr, Ti and Ta or from alloys of two or more of those and said low-refractive material is metal oxide deposited by the sputtering method by using a target of Si.

4. The plastic optical devices having the antireflection film according to claim 3, characterized in that said target of said high-refractive material contains Si.

5. The plastic optical devices having the antireflection film according to claim 3, characterized in that a target of Si is provided beside said target of said high-refractive material when depositing said high-refractive material in order to deposit said high-refractive material as a mixed film by sputtering said two kinds of targets in the same time.

6. The plastic optical devices having the antireflection film according to claim 1, characterized in that the total thickness of said antireflection film is included within the range of 4800 to 5800 angstrom and the total thickness of said low-refractive materials therein is 3500 angstrom or more.

7. The plastic optical devices having the antireflection film according to claim 1, characterized in that when said plastic base material has curvature, said antireflection film is formed as a wide band film to reduce non-uniformity of interference color caused by a difference of distribution of thickness dependent on the curvature in depositing the film by the sputtering method and change of interference color caused by oblique incidence.

8. The plastic optical devices having the antireflection film according to claim 1, characterized in that said plastic base material is a base material of an spectacles plastic lens and said antireflection film is formed on the both sides of said plastic base material.

9. The plastic optical devices having the antireflection film according to claim 1, characterized in that said antireflection film is composed of ten layers and the thickness of said low-refractive material at the sixth layer (136) positioned at the middle is increased.

10. A spectacle plastic lens having an antireflection film in which said antireflection film is coated on a plastic base material by using a sputtering method, characterized in that:

said antireflection film is a multi-layered film which is formed by depositing a first layer on the side of said plastic base material by a high-refractive material and the next layer by a low-refractive material and by alternately laminating those high-refractive materials and low refractive materials; and

a super-thin film of SiO<sub>(2−

x)</sub> is deposited as a pre-treatment layer on said plastic base material, the thickness of said super-thin film is within the range of 15 to 50 angstrom.

11. The spectacles plastic lens having the antireflection film according to claim 10, characterized in that said high-refractive material is metal oxide deposited by a sputtering method by using a target made from any one of Zr, Ti and Ta or from alloys of two or more of those and said low-refractive material is metal oxide deposited by the sputtering method by using a target of Si.

12. The spectacles plastic lens having the antireflection film according to claim 11, characterized in that said target of said high-refractive material contains Si.

13. The spectacles plastic lens having the antireflection film according to claim 11, characterized in that a target of Si is provided beside said target of said high-refractive material when depositing said high-refractive material in order to deposit said high-refractive material as a mixed film by sputtering said two kinds of targets in the same time.

14. The spectacles plastic lens having the antireflection film according to claim 10, characterized in that said antireflection film is composed of ten layers and the thickness of said low-refractive material at the sixth layer (136) positioned at the middle is increased.

15. A thickness correcting mechanism for sputtering film deposition, used in a film deposition system for depositing a thin film on the surface of an optical lens base material (10) by a sputtering method, characterized in that it comprises thickness correcting plates for correcting the difference of thickness of said thin film.

16. The thickness correcting mechanism for sputtering film deposition according to claim 15, characterized in that:

the surface of said optical lens base material (10) has curvature and a plurality of said optical lens base materials (10) are disposed horizontally at the positions of concentric circles in a circular plate holder (26) which is placed horizontally and is rotatable;

said film deposition system comprises targets (31) facing to the surfaces of said optical lens bass materials (10); and

said thickness correcting plates are mask members (51, 52) for regulating the difference of film thickness, which are disposed in the direction connecting the peripheral part and the center part in said holder, and between said targets (31) and said holder (26).

17. The thickness correcting mechanism for sputtering film deposition according to claim 16, characterized in that:

said targets (31) are composed of upper and lower targets facing respectively to the both sides of said optical lens base material (10); and

said mask members are composed of the mask member (51) for a concave surface disposed between said upper target (31) and said holder (26) and the mask member (52) for a convex surface disposed between said lower target (31) and said holder (26).

18. The thickness correcting mechanism for sputtering film deposition according to claim 17, characterized in that in said mask member (51) for the concave surface, the size in the circumferential direction of the parts corresponding to the positions where said optical lens base materials exist is greater than the size in the circumferential direction of the other parts, and that in the mask member (52) for the convex surface, the size in the circumferential direction of the parts corresponding to the positions where boundaries between said optical lens base materials exist is greater than the size in the circumferential direction of the other parts.

19. The thickness correcting mechanism for sputtering according claim 16, characterized in that said mask members (51, 52) interfere particles flying from non-erosion portions created in said targets (31).