MECHANICAL MODULATOR OF OPTICAL RADIATION Russian patent published in 1997 - IPC

FIELD: measuring equipment, applicable in photometric and radiometric instruments, as well as for amplitude and pulse-duration modulation of continuous radiation of sources in automatic remote-control systems. SUBSTANCE: the device uses a screening element installed in a frame, which, when turned, partially or completely closes the frame opening limiting the bundle of falling rays. The screening element is made in the form of an axially symmetric opaque plate of minimum thickness, whose axis of rotation is parallel with the faces and intersects the frame opening axis. The plate shape repeats the shape of the opening in the frame, or has a shape providing for the necessary dependence of variation of closing of the frame cross section area or modulated bundle by the plate projection on the section plane on the angle of its turn. Depending on application of the modulator, the plate surfaces have an absorbing or diffusion reflecting coating. The device has minimum dimensions in the direction perpendicular to the radiation bundle axis for the given aperture, which makes it possible to keep the modulator away from the image plane so as to reduce the influence of background radiation. Due to variation of the relation between the dimensions of the bundle and screening element, as well as due direction of it to the modulator at a different distance from the axis of rotation of the plate, the shape and relative pulse duration of output radiation are changed. EFFECT: enhanced accuracy. 2 cl, 1 dwg