Patent GB-816613-A (GB)
Title: Improvements in or relating to apparatus for photographically recording the instantaneous position of moving objects
IPC: G03B15/16
Filed: 1956-07-06
Abstract: 816,613. Air and marine traffic supervision. ASKANIA-WERKE A.G. July 6, 1956 [July 8, 1955 ; July 16, 1955 (2); July 25, 1955 ; Aug. 24, 1955], No. 21059/56. Class 118 (2). [Also in Group XX] Apparatus for photographically recording the instantaneous position of a moving object comprises a transparent carrier supporting a transparent map and a transparent photographic material which is sensitive to ultra-violet radiation and capable of recording a visible image without development, a source of ultra-violet radiation disposed beneath the carrier for forming a light spot, and means for moving this light spot in orthogonal directions, so that a mark can be formed on said material in a position corresponding to the instantaneous position of the object. The means for moving the light spot may be a gimbal-mounted mirror movable under the control of electrical signals representing the x, y co-ordinates of the moving object at a particular time and transmitted from a remote point at which the object is sighted. Several transmitters may be linked to the recording apparatus which may thus be used to plot the course of, e.g., aircraft or ships. In the recording'apparatus shown in Fig. 1 a beam of ultra-violet radiation from a mercury lamp 1 is focused by quartz lens 15 and reflected by mirror 5 on to a transparent carrier 6 which supports a transparent map 7 and an ultraviolet sensitive material 8, extending between spools 22 and 23 and held taut by a clamp 24. The mirror 5 is mounted in gimbals and movable by electric rotary field devices 18, 19, each associated with arrester magnets 20, 21. Interposed in the light path are an electromagnetically-operated shutter leaf 4 and rotatable discs 2, 3, bearing additional data to be recorded on the material 8 and operated by electromagnetic devices 11, 13. Electrical signals representing the x-y co-ordinates of the' object position are transmitted to the devices 18, 19 from a remote point, as also are the signals fed to the devices 11, 13. At this point is an apparatus which, as shown in Fig. 3, includes a lamp 48, the beam from which is reflected by a gimbal mounted mirror 53, on to a map 52 to form a light spot thereon at a position corresponding to that of an object sighted. This light spot, is correctly positioned by moving a joy-stick 56 linked to the mirror gimbals, and electric rotary field systems 58, 59, associated with arrester magnets 64, 65, generate signals representative of the position of the sighted object for transmission to the recorder. Signals for the correct setting of the discs 2 in the recorder are generated by an electric rotary field system 62 associated with a manually operable lever movable over a scale 61, a similar system (not shown) being provided for setting disc 3. The instantaneous position of the sighted object is recorded when a pushbutton 63 at the remote point'is depressed to energize the device 10 and remove the shutter leaf 4 from the light path. To provide an indication of the range of the object, concentric circles of light may be projected on to the material 8 by means of two spot-lights mounted on a frame, rotated by an electric motor; wedges are attached to the exterior of each spot light and are contacted by a push-rod, which extends along the rotary axis of the frame and is movable manually to adjust the angle between the projected beams. A central spot-light defining the centre of the range circles is also provided on the frame and the latter is gimbal mounted so that by manual adjustment the spot lights may be directed on any desired part of the material 8. The light from the spot-lights is such as to cause no substantial blackening of the material 8. Alternatively, a gimbal mounted mirror may reflect the beams from fixed spotlights. Several transmitters may be linked to the recording apparatus through a delay system 66 which passes the electrical signals in chronological order.