An optical filter arrangement.

摘要

An optical filter arrangement (18; 50) comprises at least two optical filter elements including a transparent substrate (46) and an optical coating typically comprising at least two overlying optical thin films (52A, 56A). The coating defines a first patterned area (57A) and a second surround area (57B) bordering the first area. The first area has substantially the same optical transmittance characteristics (38) as the second area (36) and different optical reflectance characteristics (34, 32) 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 (16) is only visible when viewed from one side of the filter arrangement. The invention extends to a method of forming such an arrangement.