Abstract: A laser beam is projected through the optical system of an endoscope and scanned in raster fashion by means of a scanning head at a proximal end of the endoscope tube. The beam is projected from a distal end of the endoscope tube so as to be scanned over an object. Light reflected from the object is detected and used to form a television image. The range of the object is measurable in a ranging mode of the apparatus in which the depth of focus of the projected laser beam is reduced using a zoom lens at the distal end of the endoscope and the focus distance of the projected beam varied until an in-focus position is detected by analysis of the reflected light. Detection of the in-focus position relies on characteristics of laser speckle, a selected portion of the object being scanned in ranging mode to detect maximum modulation in the speckle pattern which occurs when the focus distance corresponds to the range of the object.

Abstract: A laser beam is projected through the optical system of an endoscope and scanned in raster fashion by means of a scanning head at a proximal end of the endoscope tube. The beam is projected from a distal end of the endoscope tube so as to be scanned over an object. Light reflected from the object is detected and used to form a television image. The range of the object is measurable in a ranging mode of the apparatus in which the depth of focus of the projected laser beam is reduced using a zoom lens at the distal end of the endoscope and the focus distance of the projected beam varied until an in-focus position is detected by analysis of the reflected position is detected by analysis of the reflected light. Detection of the in-focus position relies on characteristics of laser speckle, a selected portion of the object being scanned in ranging mode to detect maximum modulation in the speckle pattern which occurs when the focus distance corresponds to the range of the object.

Abstract: A safety system for a laser-beam utilizing facility incorporates a safety enclosure (24) and an infra-red monitoring system (32) for detecting the development of hot spots at internal surfaces of the enclosure walls (24) and ceiling (26) which may occur as a result of stray laser radiation impinging on such surfaces. The development of a hot spot leads to shutting off the laser source (10) or interruption of the beam by means of a shutter (22).

Abstract: Light projection apparatus including a laser device and a light separation device for producing red, green and blue light beam components. Ultrasonic diffraction acousto-optical devices are provided for modulating the red, green and blue light beam components respectively, and a scanning device is provided for receiving modulated light from the acousto-optical devices and projecting the light onto a viewing surface. The red, green and blue light beam components are arranged relative to their respective acousto-optical devices so that they intercept the acoustic wave corresponding to any given signal moving through the respective crystals at different times to achieve time differences in modulation of the three components for the given signal. The scanning device is arranged to scan in two dimensions to form a raster.

Abstract: A helmet mounted projector provides offset and frame scanning capabilities or a dual channel computer generated image simulation system. The projector receives full color lasers from each channel via a separate optical path, including galvanometer controlled line scan offset mirrors designed to provide eye tracking capabilities, and combines said channels along a single optical axis to provide coordinated frame scanning from the complex image produced by the combined rasters.

Abstract: A roll and pitch motion optical system, particularly for a ground-based flight simulator visual display using a raster-scanned laser optical projector and a concave part-spherical display screen and requiring a wide-angle display. The optical system uses an input concave paraboloidal mirror and an output convex paraboloidal mirror of complementary shape. The intermediate optics comprise a collimator to constrict the display beam envelope, roll and pitch prisms positioned in the constricted area and close to the output mirror and a concave spherical mirror to reflect beams from the pitch prism back onto the output paraboloidal mirror.

Abstract: A laser system designed to minimize mode beating by splitting an incident laser beam into two approximately equal components, transmitting the components along separate paths of unequal lengths and recombining the components at a beam combiner to form the emergent laser beam. Laser mode beating is effected at frequencies dependent upon the interferometric path difference. Mode beating elimination at further frequencies is possible using further splitter/combiner combinations in series. A three-color laser modulator uses two different laser sources, each with splitter/combiner mode beating suppression optics. One beam is further split to provide, in all, three paths through three color modulators, the three paths being combined at a dichroic combiner. A color laser projection display system includes conventional line and frame scanning means following the dichroic combiner of the three-color modulator.