Patent GB-926271-A (GB)
IPC: G09B9/32
Abstract: 926,271. Television. COMMUNICATIONS PATENTS Ltd. Jan. 11, 1961 [Jan. 22, 1960], No. 2389/60. Class 40 (3). [Also in Groups XX and XXXIII] Flight training apparatus includes a representation of an object, a television camera tube with an associated lens system for viewing at least a portion of the representation, the plane of one or more of the component lenses of the system being inclinable to another of the component lenses and to the screen of the camera tube, and means for providing relative movement of camera tube and representation in accordance with a simulated or computed movement of an aircraft relative to the object. In a first embodiment a plan view transparency 10 of the ground is illuminated by a light source 11 and an image of a small area is projected by a lens 12 on to a screen 13 which is viewed by a television camera tube 34 through a lens system 18. Servo mechanisms 15 and 16 are controlled by ground-speed and azimuth computing elements, respectively, of an associated trainer or flight simulator, the simulated aircraft height controlling a further servo mechanism 17, while pitch is accounted for by a servo 22. Roll of the aircraft is simulated by rotation of the camera tube 34 by a servo mechanism 21. To ensure that the planes of the lens system 18, the screen of the camera tube 34, and the screen 13 all intersect on a common line, servo mechanisms 19 and 20 are appropriately controlled from the height-determining system of the flight simulator. The planes of the transparency 10, lens 12, and screen 13 are also arranged to intersect on a second common line by further servo mechanisms (not shown). In another embodiment suitable for simulation of take-off and landing, a scale model of an aerodrome (Fig. 2, not shown) is moved back and forth by a servo mechanism, and viewed by a television camera provided with an inclined lens system which is subject to adjustment by servo mechanisms. To overcome scale distortion the line and frame scanning waveforms may be suitably modified in accordance with the simulated altitude; alternatively a projectiontype televisor may be arranged to throw an image obliquely on to a viewing screen, the inclination of which is varied by the servo mechanism. The model is viewed through a prism 28 by a lens system 41, Fig. 4, which is carried in a mount 43 movable laterally on guides 44, 45 by a servomotor 47 operating through a rack-and-pinion and linkage 50 and controlled from the simulator. The image produced by the lens 41 is viewed by a lens system 42 which is mounted for angular movement by a servo mechanism 61 and focusing movement by a servo mechanism 66. The camera tube 56 is also mounted for adjustment by a servo mechanism 74 to bring the plane of the photocathode 55 into coincidence with the position of the image plane of lens 42. Position transducers 69, 76 signal the positions of lens 42 and camera tube 56, respectively. Potentiometers with contoured windings introduce corrections in accordance with equations given in the Specification; a schematic diagram (Fig. 5, not shown) of the interconnections between potentiometers, amplifiers, transducers and servo mechanisms is also described. The picture transmitted from the camera tube may be displayed on two screens (Fig. 7, not shown) by two projection receivers providing images which are reflected by two mirrors on to the screens. Specification 753,365 is referred to.