Abstract: The invention relates to a method of operating an optical sensor arrangement for detecting articles present in a monitored region by means of a light transmitter and a light receiver. The light transmitter emits light signals which respectively comprise a number of pulses which follow each other at a determined pulse repetition frequency.

Abstract: Light from a scanning device is directed onto a row of inclined strip mirrors 11a, 11b, 11c which are arranged one behind the other and laterally displaced relative to each other at an angle of 45.degree. to the incident light beam 16". The strip mirrors form the incident light into a number of light curtains 13a, 13b, 13c corresponding to the number of mirrors, with the individual light curtains being laterally displaced in the same way as the strip mirrors. The individual light curtains then fall onto a corresponding number of deflecting mirrors 12a, 12b, 12c which are set at an angle of 45.degree. to the incident light curtains. The deflecting mirrors thus deflect the light curtains through an angle 90.degree. and indeed into the same plane so that the undesired lateral displacement is cancelled and a broad light curtain is achieved which extends in a single plane.

Abstract: In a scanner for the optical checking of objects such as CD-discs there is provided a coherent light source; a light deflecting device which allows a light beam emitted from the light source to sweep over the object in a substantially linear scanning movement, with the optical axis of the light beam subtending a small angle with a normal to the object surface transverse to the scanning direction; and a detector for detecting light which is reflected back from the object. In the present arrangement the optical axis of the light beam also subtends a small angle with the normal to the object surface in the scanning direction. This makes it possible to avoid disturbing modulation of the detector signal due to interference effects.

Abstract: A resilient intermediate section (12) is arranged inside the hollow cavity (11) of a resilient section (14) of essentially triangular cross-section. The intermediate section (12) has a flat base portion (15) which contacts the base surface (13) of the resilient section (14) and a switching strip (18) is arranged on the flat base portion (15). In addition the intermediate section (12) has limbs (16) which extend into the tapering hollow cavity (11) and encloses the sides of the switching strip (18). If the section (14) bends due to contact with an obstacle then the limbs (16) are respectively acted on by further arching of the side surfaces (17) and act in turn via inwardly directed actuating ribs (20) on the surface of the switching strip (18) which faces the apex edge (19) of the resilient section.

Abstract: Change of distance measuring apparatus features a light transmitter - receiver unit 23 which is used to sense the distance A to the surface of a measurement object 35 and more particularly to sense changes in the distance A occurring due to changes in thickness of the measurement object 35 as it moves against a guide surface in the direction of the arrow F. The optical system features a front objective 14 which focuses a parallel beam of light received from a laser light source via beam widening optics 13', 13", a modal aperture 12 for limiting the beam to the zero order diffraction image of the laser light source and a beam dividing mirror 33. Light returned from the surface of the measurement object whether specularly reflected or scattered is gathered by the front objective 14 and is passed to a photoelectric converter 19 via the dividing mirror 33, a further objective 16 and a second modal aperture stop 18.

Abstract: Light beam switch unit containing source and/or receiver in a pressure-tight housing with sealed-in lenses, cover and cable inlet.