GB343440A - Stroboscopic light advertising devices - Google Patents

Abstract

343,440. Moving and changing signs. ABEL, A., 51A, Menckestrasse, Leipsic, Germany. Nov. 13, 1929, No. 34694. Addition to 339,446, [Class 3 (i), Advertising and displaying apparatus, Moving &c.]. [Class 3 (i).] Illumination, changing advertisements by controlling.-The advertising device of the parent Specification is modified to produce the nearly instantaneous illumination and darkening of the stroboscope by means other than an inertialess source of light. Fig. 1 shows a light relay 30 connected either directly, or through a transformer 27, to the secondary of a transformer 24 the primary of which is energized by a battery 21 through a rotary switch 22 shunted by a condenser 22a. An adjustable spark gap 26 is provided in the relay circuit. The relay may comprise a Kerr-cell, consisting of a lens which directs-light on a Nicol prism and a condenser immersed in nitro-benzol in a transparent container and connected to an alternating current. The relay is placed in the beam from a constant source of light 31 and illuminates the stroboscope disc 39 intermittently. Fig. 3 discloses a modification in which a mirror 50 counterweighted by a balance 51a is rotated about a shaft 48a so as intermittently to reflect a light beam from a constant source on to the stroboscope disc 39. A stationary mirror 55 directs the light on to the rear of the disc 39 when this is transparent, or two mirrors may be employed when the disc is opaque. A number of sources of light and of rotating mirrors may be provided to light up more than one area of the disc 39. In Fig. 6 the beam passes axially through the disc and is reflected uniformly thereover by a convex mirror 61. The moving support for the stroboscopic designs may be a cylinder or flexible band.