Polymeric optical element having antireflecting surface

• US 4,114,983 A
• Filed: 02/18/1977
• Issued: 09/19/1978
• Est. Priority Date: 02/18/1977
• Status: Expired due to Term

• Current Assignee: 3M Company
• Original Assignee: 3M Company
• Inventors: Maffitt, Kent N., Lowrey, Dean R., Brueckner, Hubert U.
• Primary Examiner(s): Corbin, John K.
• Assistant Examiner(s): Lee, John D.
• Application Number:
  US05/770,044
• Time in Patent Office: 578 Days
• Field of Search: 350/164, 350/165, 350/276 R, 264/1, 264/219, 264/220, 264/224, 427/162, 427/164
• US Class Current: 359/580
• CPC Class Codes: B29C 2059/023 Microembossing
• CPC Class Codes: B29C 37/0053 Moulding articles characterised by the shape of the surface, e.g. ribs, high polish mould construction therefor B29C33/42; surface shaping of articles B29C59/00; by incorporating filler in or near the surface B29C70/64
• CPC Class Codes: B29C 41/12 Spreading-out the material on a substrate , e.g. on the surface of a liquid
• CPC Class Codes: B29C 59/022 characterised by the disposition or the configuration, e.g. dimensions, of the embossments or the shaping tools therefor
• CPC Class Codes: B29D 11/00 Producing optical elements, e.g. lenses or prisms grinding or polishing of optical elements B24B; constructional form of optical elements G02B; optical parts of spectacles G02C7/00
• CPC Class Codes: B29D 11/00605 Production of reflex reflectors
• CPC Class Codes: B29K 2995/0026 Transparent
• CPC Class Codes: C03C 23/00 Other surface treatment of glass not in the form of fibres or filaments
• CPC Class Codes: G02B 1/11 Anti-reflection coatings
• CPC Class Codes: G02B 1/12 by surface treatment, e.g. by irradiation
• CPC Class Codes: G02B 3/08 with discontinuous faces, e.g. Fresnel lens diffractive Fresnel lenses G02B5/1876

Abstract

An optical element of polymeric material is provided with a microstructured surface, thereby rendering the surface substantially non-reflecting while maintaining a high degree of transmissivity. The element is formed via replication from a stamper prepared from a glass original having a similar microstructured surface which is formed by etching a cleaned surface of the glass in vapors of hydrofluoric acid followed by sputter etching with inert gas ions.

Claims

1. An optical element comprising a polymeric material having a surface containing a plurality of randomly positioned peaks, a predominant number of which range in amplitude approximately between 20 and 160 nm, the separation of adjacent peaks being not greater than three times the maximum amplitude of said peaks, wherein the total reflectance of visible light incident normal to said surface is less than two percent and the intensity of visible light transmitted in one direction is at least 10³ greater than the intensity of transmitted visible light measured 5°

off said one direction.

2. An optical element according to claim 1, wherein said polymeric material is selected from the group consisting of cellulose acetate butyrate, polymethyl methacrylate and polypropylene.

3. An optical element according to claim 1, wherein the element comprises a polymeric sheet material having two substantially planar major surfaces, both of which are formed to contain a said plurality of peaks.

4. An optical element comprising a polymeric material having a surface possessing antireflection characteristics such that the total reflectance of electromagnetic radiation extending over a range of wavelengths extending between λ

and ±

30% λ

is less than 2% and the intensity of radiation transmitted in one direction is at least 10³ greater than the intensity of transmitted radiation measured 5°

off said one direction, said surface containing a plurality of randomly positioned peaks, a predominant number of which range in amplitude between approximately λ

/10 and λ

/4, the separation of adjacent peaks being not greater than three times the maximum amplitude of said peaks.