Optical filter arrangement

• US 5,731,898 A
• Filed: 04/06/1995
• Issued: 03/24/1998
• Est. Priority Date: 04/12/1994
• Status: Expired due to Fees

• Current Assignee: Jax Holdings, Inc.
• Original Assignee: Domenico Orzi, Guido Orzi
• Inventors: Theron, Ettienne, Orzi, Domenico
• Primary Examiner(s): Dzierzynski, Paul M.
• Assistant Examiner(s): CHANG, AUDREY Y
• Application Number:
  US08/417,983
• Time in Patent Office: 1,083 Days
• Field of Search: 359/360, 359/585, 359/587, 359/588, 359/589, 359/590, 356/108
• US Class Current: 359/587
• CPC Class Codes: G02C 2202/16 Laminated or compound lenses
• CPC Class Codes: G02C 7/021 with pattern for identification or with cosmetic or therapeutic effects methods and processes take preference, e.g. printing, marking or copying processes B41M; identification in general G09F3/00; producing decorative effects in general B44C; surface treatment of glass C03C15/00 - C03C23/00; positioning or marking of lenses B24B13/0055
• CPC Class Codes: G02C 7/105 having inhomogeneously distributed colouring
• CPC Class Codes: G09F 13/06 using individual cut-out symbols or cut-out silhouettes, e.g. perforated signs

Abstract

An optical filter arrangement comprises at least two optical filter elements including a transparent substrate and an optical coating typically comprising at least two overlying optical thin films. The coating defines a first patterned area and a second surround area bordering the first area. The first area has substantially the same optical transmittance characteristics as the second area and different optical reflectance characteristics over at least a portion of the visible spectrum. The distinction between the first area and the second area is visually perceptible when viewed from one side of the optical filter arrangement and is substantially visually imperceptible when viewed from the opposite side of the optical filter arrangement. As a result, a coloured pattern or logo is only visible when viewed from one side of the filter arrangement. The invention extends to a method of forming such an arrangement.

Claims

1. An optical filter arrangement comprising a substrate, a first reflecting area defined by at least a first reflecting layer overlying the substrate and arranged to reflect at least a first waveband of light in the visible spectrum between 450 nm and 650 nm from a reflecting side of the filter arrangement, a second reflecting area adjacent the first reflecting area and defined by at least a second reflecting layer overlying the substrate and being arranged to reflect at least a second waveband of visible light from the reflecting side of the filter arrangement, and at least one transmission balancing means arranged to compensate for transmission mismatch in visible light transmitted through the first and second reflecting layers, whereby the distinction between the first reflecting area and the second reflecting area is visually perceptible when viewed from the reflecting side of the filter arrangement, and is substantially visually imperceptible when viewed through the filter arrangement from an opposite side thereof, wherein the transmission balancing means comprises at least a first metallic thin film of a predetermined thickness, and a second metallic thin film of the same material as the first metallic thin film and of a predetermined thickness which is different to the predetermined thickness of the first metallic thin film, and wherein the first reflecting layer includes a first reflecting surface defined by the first metallic thin film, in conjunction with at least a first optical thins film overlying the first reflecting surface, the thickness of the first optical thin film determining the particular first waveband or color of light being reflected off the first reflecting area, and the second layer includes at least the second metallic thin film.

2. An optical filter arrangement according to claim 1 in which the second reflecting layer includes a second reflecting surface defined by the second metallic thin film, in conjunction with at least a second optical thin film overlying the second reflecting surface, the thickness of the second optical thin film being different to the thickness of the first optical thin film, and the thickness of the second optical thin film determining the particular second waveband or color of light being reflected off the second reflecting area.