GB912667A - Improvements in and relating to the control of motor vehicle lights - Google Patents

Abstract

912,667. Photo-electric control of vehicle lighting. ZUSE, K. March 24, 1959 [March 27, 1958; April 11, 1958; April 12, 1958; Feb. 4, 1959], No. 10249/59. Class 40 (3). In an anti-dazzle device for road traffic vehicles the latter are provided with photoelectric control means which operates to prevent the vehicle (head) lamps illuminating the same road sector as that illuminated by the lights of an approaching vehicle. The vehicle lamps may comprise a plurality of units each controlled by a respective photo-electric cell which is arranged to receive light from the sub-sector of the road which is illuminated by its associated head lamp (Figs. 1 and 2, not shown). By this means light from an approaching vehicle which falls on a particular sub-sector or sectors causes extinction of the lamp or lamps on the controlled vehicle which also illuminate such sector or sectors and thus prevent light from the latter vehicle being directed towards the approaching vehicle. In another arrangement (Fig. 4) a single photo-electric cell 9 receives from approaching vehicles via a rotating mirror drum 11 which " scans "across the roadway and received light, such as that coming from position 7, operates to extinguish the appropriate lamp 6 as determined by a selector switch 16 rotating with the drum 11. By including rectifiers 23 (Fig. 5) in the lamp switching circuits each of the lamps which illuminate sectors to the left of that illuminated by the approaching vehicle are switched off. This is applicable to countries in which traffic moves on the righthand side of the road and the arrangement may be reversed for countries where traffic moves on the left-hand side. Fig. 6 shows a further arrangement in which light from a single head lamp 24 is obturated by a screen 27 when a photo-electric cell 39 receives light from an approaching vehicle. The optical path to the cell also includes a screen 42 which reciprocates, together with the mounting 31 of screen 27, across the optical path under the control of motors 34 and 35 in accordance with the operation of limit switches 49, 50 and a switch 48 operated by the output of the cell. In a modification of the latter arrangement the photoelectric cells responsive to light from sectors of different widths are arranged in one optical system forming a pivotable unit with a headlamp reflector system (Fig. 7, not shown). In another arrangement (Fig. 8) light from the head lamp 64 is " scanned " across the road by a rotating mirror system 66, the lamp being switched off in control 71 in response to light received by a photo-electric cell 67 from a rotating mirror system 69. The mirrors of both systems may be arranged to produce a twodimensional " scanning " effect (Fig. 12, not shown) or two separate systems of the kind shown in Fig. 8 may be employed. In a modification of the latter a cam-operated switch is arranged to switch on the head lamp 64 at the end of each rotation of the mirror systems (Fig. 13, not shown). In a still further arrangement (Fig. 14, with sectional views shown in Figs. 15, 16 and 17) light from the head lamp 77 is continuously interrupted by a rotating slotted drum 80 driven by motor 113 (to produce a high rate flicker of the light). The drum drive is transmitted by gearing to a mirror system 90 which effectively " scans " the road for light from approaching vehicles and directs such light on to a photo-electric cell 92 the signal from which operates an electromagnetic device 112 to allow a differential gear arrangement 102 to move an obturating screen 85 to prevent light from lamp 77 falling on the sector from which the cell 92 receives light. The means for corelating the motion of screen 85 with the particular sector from which cell 92 receives light involves a rotating sequential commutator 98 with co-operating fixed and rotating brushes 99 and 100 respectively and the operation is described in connection with Fig. 18 (not shown). A construction of lamp suitable for lamp 77 is described in connection with Fig. 19 (not shown). In the event that each vehicle is equipped with apparatus according to the invention it is necessary for correct operation that each vehicle proceeds with its normal head lamps in the " dipped condition to provide the minimum amount of light which is necessary to enable the apparatus to operate. Alternatively, each vehicle may be equipped with an additional source of radiation to which the photo-electric cells are responsive but to which the human eye is insensitive, e.g. ultra-violet light.