Abstract: A method of manufacturing a diffusion plate for use in a screen plate of projection TV is disclosed. The diffusion plate having a plurality of quadrangular pyramid protrusions almost over one side thereof is manufactured by means of injection molding process of plastic material. This method uses a first molding die having a first molding die surface, a pre-molding die capable of forming a first volume of molding cavity in matching with the first molding die, and a second molding die capable of forming a second volume of molding cavity smaller than the first volume in matching with the first molding die.

Abstract: There is disclosed a Fresnel lens, adapted to be placed in front of a display screen of a computer or a television set in order to magnify images for observation, which does not cause a rainbow-like pattern to appear even when annular prism elements as the constituent elements of said Fresnel lens are arranged at a fine pitch. A spherical surface having a radius of curvature corresponding to the focal distance of the lens formed by said annular prism elements of said Fresnel lens is formed within a circular area defined by a predetermined radius around the optical axis, where the rainbow-like pattern would otherwise appear due to diffraction. The predetermined pitch in arranging a plurality of annular prism elements of the Fresnel lens is equal to or less than 0.25 mm and the height of the annular prism elements in the circular area is equal to or less than 5 &mgr;m and preferably equal to or less than 7 &mgr;m.

Abstract: A magnetic head drum for a magnetic recording apparatus comprising a metallic ring of a predetermined thickness, and a support body of a plastic material formed in said metallic ring through an outsert forming process. The support body of the plastic material includes a peripheral ring-shaped portion, a central boss portion for receiving a rotating shaft and a web portion connecting the ring-shaped portion with the boss portion. A plurality of magnetic heads are provided on a periphery of the drum to rotate as a unit with the metallic ring. There is also disclosed a method for manufacturing the magnetic head drum through an injection molding process of a plastic material using a metallic ring of a predetermined thickness.

Abstract: A process for coating a front surface of a cathode ray, the process being characterized by using a ultraviolet ray setting plastic material as a coating material. According to the process, a preformed cathode ray tube bulb having a front surface is maintained with the front surface directed upwards and a transparent, fluidized or molten plastic material of ultraviolet setting property is discharged to the front surface of the bulb through a plurality of thin nozzles arranged in at least one row or one or more nozzles each having an elongated nozzle opening. In this instance, it is preferable that the molten plastic material discharged from the nozzles is received by a film forming surface which is arranged adjacent to the nozzles to form a thin plastic film before it reaches the front surface of the bulb. Preferably, the film forming surface is provided by a sheet of a material, such as a silicon rubber, which is not wettable to the plastic material.

Abstract: An injection mold for forming a thick-walled front cabinet which has a front frame panel and a cabinet portion integral with each other and which is used for an image display device containing a cathode ray tube therein. The mold has a cavity having a large depth corresponding to the large wall thickness of said cabinet, the depth of said cavity being reduced at at least a portion for forming an edge of said front frame panel contactable with said cathode ray tube, a sprue, a single runner communicating with said sprue, and a single film-type tunnel gate communicating with said runner and communicating with a portion of said cavity for forming an upper portion of said cabinet. First molten synthetic resin is first injected by a first cylinder of a sandwich injection molding machine through said tunnel gate into a portion of said cavity including said reduced depth portion.

Abstract: A method of manufacturing a cabinet for use with a display, the cabinet having a sandwiched structure at portions requiring extra strength such as the picture tube or display screen setting portion, the sandwiched structure including a flat outer surface including a resin and a core including a fiber-reinforced resin mixture. Other portions of the cabinet can be formed relatively thin-walled.

Abstract: A method of making a reflector of a satallite broadcasting receiving parabolic antenna. The reflector includes a reflective plate which has a skin layer and a core layer disposed within the skin layer which are formed by sandwich injection molding. The skin layer includes a synthetic resin, and the core layer includes a synthetic resin which has pieces of an electric wave reflective material dispersed therein. The parabolic surface of the reflective plate is coated with a protective coating.

Abstract: An eight bottle carrying case constructed from durable high density polyethylene is lightweight and easy to clean. The case can be nested when empty with similar cases to conserve space and, when full, can be stacked with like cases in an aligned array of cases or cross-stacked on two underlying like cases which are side-by-side and across the long axis of the above cross-stacked case or cases. To convert from aligned stacking of the cases to nesting thereof, alternate cases are turned 180 degrees relative to each other to alter the supportive and interfitting relationship of integral struts on the opposite long side walls of each case. The struts of each case also form bottle positioning means in the case.

Abstract: A lightweight, tough and durable bottle carrier is molded as a unit from high density plastics, is nestable with like carriers, and is stackable in two orthogonal directions with like carriers. The carrier has a central lifting handle flush with the top edge thereof and has plural discrete bottle cells in two rows on opposite sides of the handle. End stacking projections and cross stacking recesses are provided at the bottom of the carrier as well as individual bottle centering elements. Convenience and high versatility are featured. The carrier may be received in shallow or full depth, open or pocketed, cases.

Abstract: A unitized molded plastic carrier for paired bottles or other containers features an over the top handle for lifting and carrying and a separator partition for the bottle receiving compartments of the carrier which materially strengthens the construction. The carrier may be nested telescopically with identical carriers within a minimum vertical space and plural carriers are receivable in a parent carrying case. A strong and economical carrier utilizing a minimum of moldable material is provided.

Abstract: A portable stereo audio apparatus consists of a pair of speaker cabinets each containing a loudspeaker and a main cabinet containing electric devices such as amplifiers and a radio receiver. The speaker cabinets and the main cabinet are in the form of rectangular boxes. The speaker cabinets have half the width of the main cabinet and are normally set on the main cabinet. The speaker cabinets are hinged at their lower outer edge to each upper outer edge of the main cabinet so that when the audio apparatus is used as a stereophonic system the speaker cabinets are rotated about the hinges and located at both side of the main cabinet. The speaker cabinets have the edge diagonally opposite the lower outer edge, i.e., the upper inner edge, so formed as to provide gripping means when the speaker cabinets are rotated about the hinges and located on top of the main cabinet that enable the apparatus to be gripped by one hand and toted about.

Abstract: Bottle carrying crate which has six bottle receiving compartments arranged in two rows. The crate is also provided with an over-top handle for facilitating single hand carrying of the crate. The design of the crate is such that a plurality of crates can be stacked one on the other with minimum vertical dimension.