Multi-layer non-reflecting film

• US 4,260,222 A
• Filed: 06/29/1979
• Issued: 04/07/1981
• Est. Priority Date: 07/11/1978
• Status: Expired due to Term

• Current Assignee: Olympus Optical Corporation Limited (Olympus Corporation)
• Original Assignee: Olympus Optical Corporation Limited (Olympus Corporation)
• Inventors: Kozawa, Tokujiro
• Primary Examiner(s): Hoffman, James R.
• Application Number:
  US06/053,419
• Time in Patent Office: 648 Days
• Field of Search: 427/162, 427/166, 350/164, 428/539, 428/216, 428/333
• US Class Current: 359/586
• CPC Class Codes: C03C 17/3417 all coatings being oxide coatings
• CPC Class Codes: C03C 17/3452 comprising a fluoride
• CPC Class Codes: G02B 1/115 Multilayers
• CPC Class Codes: G02B 5/285 comprising deposited thin solid films G02B5/281 - G02B5/289 take precedence; multilayered film filters for fibre optic multiplexing G02B6/29361
• CPC Class Codes: G02B 5/286 having four or fewer layers, e.g. for achieving a colour effect
• CPC Class Codes: Y10T 428/24975 No layer or component greater than 5 mils thick
• CPC Class Codes: Y10T 428/261 In terms of molecular thickness or light wave length

Abstract

A multi-layer non-reflecting film uniform in refractive index and having favorable optical characteristics which comprises at least one layer made of a mixture of Ta₂ O₅ and ZrO₂ containing 5 to 25% of Ta₂ O₅.

Claims

1. A multi-layer non-reflecting film comprising at least two layers of least one of which is made of a mixture of tantalum oxide (Ta₂ O₅) and zirconium oxide (ZrO₂) containing 5 to 25% by weight of tantalum oxide (Ta₂ O₅).

2. A multi-layer non-reflecting film according to claim 1 consisting of a first layer having thickness of λ

/2 and a second layer having thickness of λ

/4 wherein said first layer is made of said mixture of tantalum oxide (Ta₂ O₅) and zirconium oxide (ZrO₂).

3. A multi-layer non-reflecting film according to claim 2 wherein said first layer consists of a film which is located on the side in contact with the glass base plate thereof, is composed of a substance with a low refractive index and has thickness less than the quarter wave as determined by refractive index of said glass base plate and is a mixture of ZrO₂ and Ta₂ O₅ having a total thickness less than the half wave and is equivalent to the half wave film in reflectance and in delay or advance of phase after final interference of the reflection light from the respective interface.

4. A multi-layer non-reflecting film according to claim 1 consisting of said first layer having thickness of λ

/4 and said second layer having thickness of λ

/4 wherein said first layer is made of said mixture of tantalum oxide (Ta₂ O₅) and zirconium oxide (ZrO₂).

5. A multi-layer non-reflecting film according to claim 1 consisting of a first layer having thickness of λ

/4, a second layer having thickness of λ

/2 and a third layer having thickness of λ

/4 wherein said second layer is made of said mixture of tantalum oxide (Ta₂ O₅) and zirconium oxide (ZrO₂).

6. A multi-layer non-reflecting film according to claim 1 wherein said first layer consists of at least two films of a substance having high refractive index and a substance having a low refractive index which are evaporated alternately with each other, having a total optical thickness less than a quarter wave, and equivalent in reflectance and delay or advance in phase after mutual interference of reflection light from the respective interfaces to the quarter wave film.

7. A multi-layer non-reflecting film according to claim 1 consisting of a first layer having thickness of 3λ

/4, a second layer having thickness of λ

/2 and a third layer having thickness of λ

/4 wherein said second layer is made of said mixture of tantalum oxide (Ta₂ O₅) and zirconium oxide (ZrO₂).

8. A multi-layer non-reflecting film according to claim 7 wherein said first layer consists of at least six films made of a substance having a high refractive index and a substance having a low refractive index which are evaporated alternately with one another, having a total optical thickness less than a three quarter wave and equivalent in reflectance and delay or advance in phase after mutual interference of reflection light from the respective interfaces to the three quarter wave film.