Abstract: The disclosed film viewer comprises a box with a bottom and an inclined top having a diffusion plate fitted therein, a light source disposed in the box, and a number of reflectors distributed on the inner surface of the box so as to reflect light beams from the light source in such a manner that uniform brightness is provided throughout the entire surface of the diffusion plate.

Abstract: The disclosed sheet has a plurality of rectangular recesses in rows and columns for holding one transparency in each recess, and an inclined surface portion is formed substantially at the center of the bottom wall of each rectangular recess, so that reflection from the center of the bottom wall of the recess is angularly deviated from reflection from the center of the transparency held by the recess.

Abstract: The disclosed structure holds a rectangular thin-piece such as a photographic transparency on a base sheet between at least two holding portions formed on the base sheet and a thin-piece seat being recessed relative to the holding portions. A push-in area is formed on the base sheet adjacent to both the seat and at least one of the holding portions. One edge of the thin-piece is once pushed in between the push-in area and the holding portion adjacent thereto to an extent sufficient for clearing the thin-piece from the remainder of the holding portions, and then the thin-piece is moved back from the push-in area onto the seat where an abutting member abutts the thin-piece to keep the thin-piece in position. A plurality of the thin-piece holding structures are formed on one base sheet to form a slide filing sheet.

Abstract: A disclosed projector includes a condenser lens, a plurality of light source means having different focal lengths and disposed around the condenser lens, a projecting lens with an adjustable distance from the condenser lens, and a stage glass located between the condenser and projecting lens for carrying a transparent positive thereon. Depending on the size of the transparent positive, one of the light source means is selected and the distance between the condenser and projecting lens is adjusted, so as to project an image of substantially fixed magnitude with a constant brightness regardless of said size of the transparent positive.

Abstract: A filing sheet for microscope slides comprising;a unitary rotary plastic sheet having a plurality of rectangular recesses depressed from the outer periphery and spaced apart by longitudinal partition wall and lateral partition wall in lateral and longitudinal relationship, each of said rectangular recesses being defined by a pair of side walls of longitudinal partition walls and a pair of lateral partition walls for receiving a microscope slide;microscope slide-retaining means projected inwardly into said rectangular recess from a pair of side walls of said opposing longitudinal partition walls and having a space for inserting a microscope slidebetween the end of said slide-retaining means and an opposite lateral partition walls;an air-ventilation opening provided on the side portion of the plane of said rectangular recesses under said slide-retaining means;fingertip recesses provided in the borderline of said adjacent rectangular recesses and protruded downwardly from the plane of said rectangular recess;upr

Abstract: A slide file sheet includes a plurality of rectangular recesses formed by longitudinally and traversely extending bounding walls for arranging a plurality of slide films therein and holding lugs extending from side walls of the bounding walls inwardly of the rectangular recesses for holding the slide films.The file sheet according to the invention comprises first draft channels formed in the bounding walls and in support portions for supporting mounts of the slide films for communicating the spaces on the upper surfaces of the slide films with those on the lower surfaces of the films, and second draft channels formed in the support portions for communicating the spaces on the lower surfaces of the films with punched openings below the holding lugs when the slide films are held within the rectangular recesses.

Abstract: A self-supporting plate for holding photographic slides includes a unitary plate having a plurality of depressions spaced apart in lateral and longitudinal relationship and surrounded by two side partition walls and two end partition walls and having a substantially flat bottom wall. Each depression is adapted to receive a photographic slide therein. The self-supporting plate further comprises projections provided on and along part of the opposite side surfaces of the side partition walls, the projections being adjacent to one of the end partition walls in parallel spaced relation to the flat bottom and projecting inwardly of each depression. A groove is provided in the flat bottom of the depression between the mutually opposing projections of each depression, with its opposite side partition walls positioned on the opposite sides of a line on the bottom wall of the depression in parallel thereto.

Abstract: A slide filing plate having a plurality of pockets for holding a plurality of slides in a common plane, each pocket having a translucent or transparent membrane secured thereto in parallel to but spaced from the bottom of the pocket. The spacing from the membrane to the slide film is greater than the distance from the slide supporting wall of the pocket to the slide film, so that the slide can be projected as placed on the filing plate without being disturbed by the images of the veins and particles on the surface of the membrane.