GB399931A - Improvements in sound reproducing apparatus combined with an optical projection screen - Google Patents

Abstract

399,931. Loud-speakers. STEVENS, A. H., 5, Quality Court, Chancery Lane, London.-(Trans-Lux Daylight Picture Screen Corporation ; 247, Park Avenue. New York, U.S.A.) June 4, 1932, No. 15878. [Class 40 (iv).] A combined system for the reproduction of sound and for the display of images by the passage of a light-beam through a screen is characterized in that the screen is maintained taut by cords or lacing connected to a frame, sound units being provided to vibrate independently of the screen and disposed at opposite sides of the screen between the screen image area and the frame for directing separate soundwave beams into the audience area, and in which the screen image area is constructed of such material that it is largely impermeable to sound waves, whereby the front surface thereof acts as a sound-wave baffle to overcome the directional effect of the sound waves. The screen, which is formed of moulded gelatinous material with which a fabric sheet may be incorporated in known manner, has, immediately adjacent the periphery thereof, spaced areas much less sound obstructing than the image area of the screen. The screen S, Fig. 3, is held under tension by being laced in a frame 3, and is stretched over ribs 4 provided with a felt layer 4a. The spaced areas O are openings in the screen S covered by fabric sections F. Disposed behind each of the areas O is a loudspeaker L with an annular ring 9 of felt disposed between the flanged ends of the conical portion 6 of the frame and the screen S. The screen may have side members 12. The spaced openings O may, in modifications of the invention, be composition plates at the side of or totally surrounding the screen, and to which the screen may or may not be laced.