Optical film

• US 7,361,963 B2
• Filed: 12/13/2005
• Issued: 04/22/2008
• Est. Priority Date: 12/15/2004
• Status: Expired due to Fees

• Current Assignee: Nippon Sheet Glass Company Limited (Nippon Telegraph and Telephone Corporation)
• Original Assignee: Nippon Sheet Glass Company Limited (Nippon Telegraph and Telephone Corporation)
• Inventors: Ikadai, Masahiro
• Primary Examiner(s): COLEMAN, WILLIAM D
• Application Number:
  US11/301,873
• Publication Number:
  US 20060127604A1
• Time in Patent Office: 861 Days
• Field of Search: 349/113, 257/435, 428/1.1, 428/1.62, 428/545, 428/620
• US Class Current: 257/435
• CPC Class Codes: C09K 2323/00 Functional layers of liquid crystal optical display excluding electroactive liquid crystal layer characterised by chemical composition
• CPC Class Codes: C09K 2323/061 Inorganic, e.g. ceramic, metallic or glass
• CPC Class Codes: G02B 5/021 the diffusion taking place at the element's surface, e.g. by means of surface roughening or microprismatic structures
• CPC Class Codes: G02B 5/0236 the diffusion taking place within the volume of the element
• CPC Class Codes: G02B 5/0268 characterized by the fabrication or manufacturing method
• CPC Class Codes: G02B 5/0289 used as a transflector
• CPC Class Codes: G02B 5/0808 having a single reflecting layer G02B5/0883, G02B5/0891 take precedence
• CPC Class Codes: G02B 5/0858 the reflecting layers comprising a single metallic layer with one or more dielectric layers
• CPC Class Codes: G02F 1/133553 Reflecting elements associated to illuminating devices G02F1/133605
• CPC Class Codes: Y10T 428/12007 Component of composite having metal continuous phase interengaged with nonmetal continuous phase
• CPC Class Codes: Y10T 428/12528 Semiconductor component

Abstract

An optical film which enables desired optical properties to be obtained easily, and enables the durability to be improved. A metal film 32 is formed on an inner major surface 12a of a glass substrate 12. A plurality of first island structures 33 is formed scattered as islands on an inner major surface 32a of the metal film 32. A plurality of second island structures 31 is formed scattered as islands on the inner major surface 12a of the substrate 12. At least one set of the plurality of first island structures 33 and the plurality of second island structures 31 are made of at least one selected from the group consisting of metals and metal oxides having a different standard electrode potential to a metal of the metal film 32.

Claims

1. An optical film formed on a major surface of a substrate, the optical film comprising:

a metal film formed on the major surface of the substrate; and

at least one set of a plurality of first island structures formed scattered as islands on a major surface of said metal film and a plurality of second island structures formed scattered as islands on the major surface of the substrate;

wherein said at least one set of the plurality of first island structures and the plurality of second island structures are made of at least one selected from the group consisting of metals and metal oxides having a different standard electrode potential to a metal of said metal film, and

wherein said metal film is made of at least one selected from the group consisting of metals having a positive standard electrode potential, and said at least one set of the plurality of first island structures and the plurality of secon disland structures are made of at least one selected from the group consisting of metals and metal oxides having a negative standard electrode potential.

2. An optical film as claimed in claim 1, wherein a mean pitch of said at least one set of the plurality of first island structures and the plurality of second island structures is not less than 400 nm.

3. An optical film as claimed in claim 1, wherein a mean height of said at least one set of the plurality of first island structures and the plurality of second island structures is in a range of 2.0 nm to 7.0 nm.

4. An optical film as claimed in claim 1, wherein said metal film is made of at least one selected from the group consisting of silver, chromium, and aluminum.

5. An optical film as claimed in claim 1, wherein the substrate is made of glass.

6. An optical film as claimed in claim 1, used in a light-reflecting substrate for an apparatus selected from a reflection type liquid crystal display apparatus and a joint reflection/transmission type liquid crystal display apparatus.

7. An optical film as claimed in claim 2, wherein the mean pitch is in a range of 400 nm to 900 nm.

8. An optical film as claimed in claim 2, wherein a percentage ratio of an equivalent circle mean diameter to the mean pitch for said at least one set of the plurality of first island structures and the plurality of second island structures is in a range of 10% to 90%.

9. An optical film as claimed in claim 4, wherein said at least one set of the plurality of first island structures and the plurality of second island structures comprise indium tin oxide.