GB528796A - Improvements relating to light-polarizing devices - Google Patents

Abstract

528,796. Pictures. INTERNATIONAL POLAROID CORPORATION. May 3, 1939, Nos. 13266 and 13267. Convention dates, May 11, 1938, and May 20, 1938. [Class 11] [Also in Group XX] Polarizing devices comprise (1) two superposed contiguous or spaced layers of polarizing material each having a,separate pattern or image composed of areas differing in polarizing power, or (2) a layer bearing an image varying in polarizing power in accordance with a photographic image; the superposed images may be the members of a stereoscopic pair, and may be carried by kinematograph film, images being projected therefrom by unpolarized light and viewed through an analyser. The polarizing material may be a crystal or orientated crystals of herapathite &c. and the polarizing effect may be locally destroyed by chemical action or by ultra-violet radiation; alternatively polarizing material may be removed, or its first deposition may be controlled. A photographic original may be used in the preparation of the surface, either by applying to the surface a gelatin relief carrying the destructive solution, or by printing with ultra-violet radiation through a transparency opaque to such radiation. The polarizing material may be unsupported by a base, or may be carried by a transparent or opaque support of paper, glass, cellulose derivative, resin, artificial resin, metallic foil &c. The Figure shows a kinematograph film comprising a support 90 having polarizing coatings 92, 94 on opposite sides and respectively constituting the right and left images of stereoscopic pairs. The axes 16, 26 of the two polarizing layers are perpendicular to one another, and the superposed images may be projected by an ordinary projector 60, 64 on to a translucent or opaque non-depolarizing screen 70, and be viewed through analyzing spectacles 80. The film images may be viewed directly, may be in superimposed coatings, both on the same side of an opaque or transparent base or unsupported by a base, and may be unrelated or "still" images. The Specification as open to inspection under Sect. 91 describes also the formation of layers by depositing polarizing material from a printing surface. This subject-matter does not appear in the Specification as accepted.