G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
G03B21/00—Projectors or projection-type viewers; Accessories therefor
G03B21/54—Accessories
G03B21/56—Projection screens
G03B21/60—Projection screens characterised by the nature of the surface
Source de lumiere multi-effets a usage notamment de projecteur pour la photographie, le cinema et la television, ou de luminaire et procede de fabrication de cette source de lumiere
Procede de fabrication de chevilles destinees a l'ancrage dans le sol, en particulier de poteaux ou piquets, et chevilles obtenues au moyen dudit procede