| 摘要 |
457,830. Projection screens. DIGGLE, A. H., 186, Peel Green Road, Patricroft, Lancashire, and YONWIN, C. H., 5, Pine Avenue, Besses o' th' Barn, Whitefield, Manchester. June 11, 1935, No. 16758. [Class 97 (i)] A woven textile base is treated on one or both sides with a translucent glutinous or farinaceous cream or paste filling the interstices and rendering the fabric translucent; the base may be initially treated with glycerine, amyl varnish, &c., to render it less opaque, and may be initially or finally treated with waterproofing or fire-resisting substances, or such substances may be added to the glutinous or farinaceous substance. The base may be cotton, silk, crepe, or linen; the glutinous paste may be prepared from bones, pelts, etc.; the farinaceous paste may be prepared from flour, starch, &c. ; the waterproofing and fire-resisting composition may comprise gelatin and formaldehyde, or gelatin and potassium bichromate exposed to light. The screen is flexible and translucent, may be tinted, and may be provided with a reflective backing. Sound-transmitting perforations may be provided in an opaque surround, and the surround may be collapsable and light shielding. The paste may be enclosed between two or more fabric layers, and transparent or translucent beads may be caused to adhere to one or both sides of the screen. According to the Provisional Specification, the base may be of paper or may be omitted, the translucent material may be gelatin or celluloid, alum or saltpetre may be used for fireproofing, the surface may be dimpled, or be treated so as to be irridescent or to produce a ground glass effect. |
