Light absorptive film having an anti-reflecting property

• US 4,488,775 A
• Filed: 05/11/1982
• Issued: 12/18/1984
• Est. Priority Date: 05/26/1981
• Status: Expired due to Term

• Current Assignee: Olympus Optical Corporation Limited (Olympus Corporation)
• Original Assignee: Olympus Optical Corporation Limited (Olympus Corporation)
• Inventors: Yamamoto, Kimiaki
• Primary Examiner(s): Corbin, John K.
• Assistant Examiner(s): Propp, William
• Application Number:
  US06/377,174
• Time in Patent Office: 952 Days
• Field of Search: 350/1.7, 350/164, 350/163, 350/166, 350/292
• US Class Current: 359/588
• CPC Class Codes: C03C 2217/734 comprising an alternation of high and low refractive indexes
• CPC Class Codes: G02B 1/116 including electrically conducting layers
• CPC Class Codes: G02B 5/22 Absorbing filters G02B5/201 - G02B5/208 take precedence

Abstract

A light absorptive film comprising a first sub-film and a second sub-film each including at least one dielectric layer and at least one metallic layer which have anti-reflecting functions even when used independently and arranged oppositely on both sides of another dielectric layer. Said light absorptive film exhibits anti-reflecting effect for light incident on said first sub-film and said second sub-film.

Claims

1. A light absorptive film comprising a first sub-film comprising a first dielectric layer and a first metallic layer, a second sub-film comprising a second dielectric layer and a second metallic layer, and a third dielectric layer, said first and second sub-films being arranged oppositely on both the sides of said third dielectric layer and said light absorptive film having the following numerical data:

space="preserve" listing-type="tabular">______________________________________ n.sub.0 = 1.52 (glass plate) n.sub.1 = 2.33 d.sub.1 = 30 nm n.sub.2 = 1.97-3.33i d.sub.2 = 10.2 nm n.sub.3 = 1.33 d.sub.3 = 300.9 nm n.sub.4 = 1.97-3.33i d.sub.4 = 10.2 nm n.sub.5 = 2.33 d.sub.5 = 30 nm n.sub.6 = 1.52 (glass plate) ______________________________________

2. A light absorptive film comprising a first sub-film comprising a first dielectric layer and a first metallic layer, a second sub-film comprising a second dielectric layer and a second metallic layer, and a third dielectric layer, said first and second sub-films being arranged oppositely on both the sides of said third dielectric layer and said light absorptive film having the following numerical data:

space="preserve" listing-type="tabular">______________________________________ n.sub.0 = 1.52 (glass plate) n.sub.1 = 2.33 d.sub.1 = 38.6 nm n.sub.2 = 1.97-3.33 i d.sub.2 = 10.2 nm n.sub.3 = 1.33 d.sub.3 = 142.9 nm n.sub.4 = 1.97-3.33 i d.sub.4 = 10.2 nm n.sub.5 = 2.33 d.sub.5 = 30 nm n.sub.6 = 1.52 (glass plate) ______________________________________

3. A light absorptive film comprising a first sub-film comprising a first dielectric layer and a first metallic layer, a second sub-film comprising a second dielectric layer and a second metallic layer and a third dielectric layer, said first and second sub-films being arranged oppositely on both the sides of said third dielectric layer and said light absorptive film having the following numerical data:

space="preserve" listing-type="tabular">______________________________________ n.sub.0 = 1.52 (glass plate) n.sub.1 = 2.33 d.sub.1 = 30 nm n.sub.2 = 1.97-3.33 i d.sub.2 = 9.1 nm n.sub.3 = 1.33 d.sub.3 = 127.8 nm n.sub.4 = 1.97-3.33 i d.sub.4 = 12.7 nm n.sub.5 = 2.33 d.sub.5 = 30 nm n.sub.6 = 1.52 (glass plate) ______________________________________

4. A light absorptive film comprising a first sub-film having a light absorptive function when used independently, and comprising a first dielectric layer and a first metallic layer, and a second sub-film having a light absorptive function when used independently, and comprising a second dielectric layer and a second metallic layer, and a third dielectric layer, said first and second sub-films being arranged oppositely on both the sides of said third dielectric layer, said first and second dielectric layers being made of the same material, and said first and second metallic layers being made of different materials.

5. A light absorptive film according to claim 4 having the following numerical data.

6. A light absorptive film according to claim 4 wherein wavelength dependency of phase variation of transmission light of said first metallic layer is made opposite to that of said second metallic layer.

7. A light absorptive film comprising a first sub-film having a light absorptive function when used independently, and comprising a first dielectric layer and a first metallic layer, a second sub-film having a light absorptive function when used independently, and comprising a second dielectric layer and a second metallic layer, and a third dielectric layer, said first and second sub-films being arranged oppositely on both the sides of said third dielectric layer, said first and second dielectric layers being made of different materials, and said first and second metallic layers being made of different materials.

8. A light absorptive film according to claim 7 wherein wvelength dependency of phase variation of transmission light of the first metallic layer is opposite to that of said second metallic layer.

9. A light absorptive film according to claim 7 wherein each of said first and second sub-film consists of a dielectric layer, a metallic layer and a dielectric layer.

10. A light absorptive film comprising a first sub-film consisting of a first dielectric layer and a first metallic layer, a second sub-film consisting of a second dielectric layer and a second metallic layer, and a third dielectric layer, said first and second sub-films are arranged oppositely on both the sies of said third dielectric layer, said light absorptive film satisfying a condition of |r₀ |+|r₂ |e^-γ

<

|r₁ | and said third dielectric layer has an optical thickness equal to λ

/4 multiplied by an odd integer,

wherein the reference symbol r₀ represents reflectance of the incidence surface of said first dielectric component layer, the reference symbol r₁ designates reflectance of the boundary surface between said first dielectric layer and said first metallic layer, and the reference symbol r₂ denotes reflectance of the boundary surface between said first metallic layer and said third dielectric layer.

11. A light absorptive film comprising a first sub-film consisting of a first dielectric layer and a first metallic layer, a second sub-film consisting of a second dielectric layer and a second metallic layer, and a third dielectric layer, said first and second sub-films being arranged oppositely on both the sides of said third dielectric layer, said light absorptive film satisfying a condition of |r₀ |+|r₂ |e^-γ

>

|r₁ | and said third dielectric layer having an optical thickness equal to λ

/4 multiplied by an even integer,

wherein the reference symbol r₀ represents reflectance of the incidence surface of said first dielectric component layer, the reference symbol r₁ designates reflectance of the boundary surface between said first dielectric layer and said first metallic layer, and the reference symbol r₂ denotes reflectance of the boundary surface between said first metallic layer and said third dielectric layer.