A laminated, cylindrical, metal screen or molding element for vacuum perforation of plastic film or sheets, comprising two or more relatively thin cylindrical metal screens, each having a predetermined inside and outside diameter and each having a plurality of openings or holes therein of a predetermined size and geometrical shape, and said relatively thin screens stacked and bonded together, diametrically one inside the other thereby providing a screen of a desired thickness and a desired hole ...

Separating equipment having a partially submerged vibratory screen in a screening device wherein oversized particles are induced to flow in a spiral direction outwardly from a central submerged area of the screen. A low velocity inlet manifold is employed centrally above the screen and a spray mechanism directs clearing spray to a peripheral area outwardly of the submerged portion of the screen. The screen is submerged by means of a chamber which extends outwardly above the lower most portion of...

A focusing screen in a split image coincidence type range finder provided with an objective lens forming an imaging plane comprises a plurality of light diffusing portions each of which has a surface inclined with respect to the imaging plane. A number of minute depressions or projections are formed on the inclined surface. The depressions or projections are arranged in the form of a matrix along a first direction and a second direction intersecting each other and symmetrical with respect to a f...

Sorting screen for fibre suspensions comprising a screen wall having recesses on a first side and narrower sorting apertures on the other, second side, these apertures opening into the recesses and the recesses each extending over a plurality of sorting apertures and being spaced in all directions from one another such that the screen wall has a net structure on its first side between the apertures. In order to achieve the utmost fineness when sorting with such a screen the recesses are arranged...

A projection screen comprises a single plate of a transparent material. The diffusion in the horizontal direction is provided by filamentary particles which are oriented substantially in one direction in the plate material. Both surfaces of the plate are then capable of performing different functions, yielding a projection screen with an optimally uniform brightness distribution, minimal color faults and maximum contrast.

The fireplace screen comprises a frame defining a central opening and including first and second pairs of vertical guide tracks along opposite lateral sides of the opening. A housing is mounted above the frame and a first flexible covering element is mounted for movement in the first pair of guide tracks. The first flexible covering element comprises a perforate mesh formed of heat resistant material. A second flexible covering element is mounted for movement in the second pair of guide tracks. ...

A well screen is provided, for insertion into a well, for screening out sand and other particles from the well, and for connection at its upper end to a pipe for delivering water or other liquid up from the well, with the well screen having a skin with slits in it for passage of liquid therethrough, and with the skin having internal rigidifying supports. The skin is provided with a surface area increase in the form of undulations preferably of sawtooth configuration throughout its surface, and i...

The present invention provides a screen system (8) suitable for use in a vibratory screen apparatus (1), and comprising: a screen element (11) and a support frame (12) therefor, as well novel screen elements (11) and mesh panels (19) therefor, and the use thereof. The screen element (11) consists essentially of a mesh panel (19) provided with first and second elongate support members (22, 23) extending along opposite end portions of the mesh panel (19). The support frame (12) has spaced apart fi...

A projection screen for use in a projection system is described. In an embodiment of the present invention, a projection system includes a projector and a projection screen. The projector is configured to project an image composed of visible light in one or more ranges of wavelengths. The projection screen has a plurality of sub-pixels that reflect and/or transmit the one or more ranges of wavelengths to display the image and absorb visible wavelengths of light in at least one other range not in...

A film carrier tape for mounting electronic parts comprises an insulating film, a wiring pattern formed on a surface of the insulating film, and a solder resist layer formed by moving a squeegee using a screen mask of a prescribed pattern that is formed in such a manner that connecting terminal portions of the wiring pattern should be exposed. The edge of the solder resist layer is formed almost in parallel or almost at right angles to the moving direction of the squeegee used in the application...