A control system for hospital theatre operating lamps

摘要

950,745. Automatic position control. QUARZLAMPEN G. m. b. H. Sept 9, 1960 [Sept. 12, 1959], No. 31157/60. Heading G3R. [Also in Division H4] The beam of light from a lamp in an operating theatre is automatically directed by means of a photo-electric control system at a portable auxiliary light source which is placed by the surgeon at the point which he wishes to be illuminated by the lamp. As shown the lamp 1 is mounted in a fork in which it may be rotated in either sense about an axis AA (perpendicular to the optical axis of the lamp) by a motor 4, the fork being capable of rotation in either sense about an axis BB (perpendicular to the other two axes) by a motor 5. The motors 4 and 5 are controlled by pairs of photo-cells 6, 7, and 8, 9, respectively signals from each of the two cells in each pair causing rotation in opposite senses of the appropriate motor, the lines of sight of the cells being symmetrical in the field of illumination of the lamp so that its optical axis is directed at the auxiliary light source. Either or both of two methods may be used to guard against reflected light from the lamp affecting the photo-cells. The first is to use radiation from the auxiliary source which is outside the spectrum of light from the lamp, e.g. ultraviolet. The second is to modulate the radiation from the auxiliary source at a frequency of the order of ten times that at which the light from the lamp is modulated by its A. C. mains supply and to apply the photo-cell signals to the motors through high pass filters.