Abstract: An optical arrangement, in particular for use as a transmitting and/or receiving optical system in optoelectronic sensors, comprises at least one diffractive optical element integrated into transparent material, with the unit formed by the transparent material and the diffractive optical element having at least two different functions such as, for example, image forming functions, polarization, beam division, beam forming, beam shaping and/or the provision of a subaperture.

Abstract: An apparatus is described for generating a light curtain which includes an originally spherical strip-like concave mirror 10 and a light deflecting element 12 arranged in the vicinity of the focal point of the concave mirror. The light deflecting element 12 guides a bundled light beam periodically over the concave mirror 10. The strip-like concave mirror 10 is twisted within itself in such a way that each surface portion of the concave mirror 10 which is illuminated during a complete sweep of the light beam extends at at least substantially the same angle to the beam axis in a plane perpendicular to the scanning direction.

Abstract: The light sensor has a light transmitter (10, 12) which radiates the light along an axis (x.sub.0) of a transmitter system and two light receiving systems (12, 14) which pick up the light scattered back from an object (G) to be detected along a receiving system axis (x.sub.1, x.sub.2). A light sensitive element (16) has three detection zones (El.sub.T, E.sub.H, E2.sub.T) arranged in a row of which the outer zones (E1.sub.T and E2.sub.T) each receive light via one of the receiving systems (12, 14) from a sensing zone (T) and of which the central detection zone (E.sub.H) accepts light via both light receiving systems from the background region (H) of the field of view of the light sensor. An output signal which is used for object recognition is obtained by additive superposition of the signals of the detection zones (E1.sub.T, E2.sub.T) associated with the scanning region (T) and by difference formation with the signal from the detection zone (E.sub.H) associated with the background region (H).

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: A picture recording apparatus comprises a light source (16) which illuminates the object to be recorded, a light sensitive semiconductor row (12), and an objective (16) which images a strip-like section (13) of the object onto the semiconductor row (12). A relative movement takes place between the semiconductor row (12) and the image of the strip-like section (13) located thereon in a direction perpendicular to the longitudinal extent of the row and in the image plane. For this purpose a light deflecting device (14), which continuously displaces the image of the strip-like section (13) in a direction perpendicular to the longitudinal extent of the semiconductor row (12) and in the image plane (15), is arranged between the object (11) and the semiconductor row (12).

Abstract: An optical autocollimation measuring apparatus has a light transmitter-receiver arranged in a housing (15). An image of the light source (11) is formed in the objective (12) by a condensor (9) through the beam divider (20). The objective (12) in turn forms an image of the exit pupil of the condensor (9) in the plane of the retroreflector via the measuring path (13). The retroreflector (14) reflects the incident light beam substantially back on itself to the housing (15) of the light transmitter-receiver, where the received light beam is deflected by the beam divider (20) to a photoreceiver (21). A deflecting mirror (16) is located between the front objective (12) and the measuring path (13) and consists of two parts which are pivotable relative to one another, about a pivot axis (25) extending perpendicular to the optical axis (17), from an extended position into a position in which they are displaced by 90.degree. relative to one another.

Abstract: A spectroanalytical gas measuring apparatus has a radiation source (36), a transmitting condensor (19), an objective (13) and a beam divider (11) which deflects at least a part of the radiation reflected back to the apparatus by a reflector (40) to a polychromator or spectrometer (32). The transmitted radiation falls after the beam divider (11) onto a deflecting mirror (12) which is adjustable between two positions and which directs the light to an objective reflector (13). The objective reflector (13) reflects the radiation to a follow-up mirror (15) arranged opposite to the beam passage opening (14). At least one long and one short focal length objective reflector (13) are provided in order to ensure different ranges of distance in conjunction with the adjustable deflecting mirror (12).

Abstract: In a rotatable mirror arrangement for generating a scanning beam which is displaced in steps parallel to itself a plurality of plane mirrors (11 to 16) are arranged in a helically displaced arrangement around a body (18) rotatable about an axis of rotation (17). The plane mirrors, which are of the same size are illuminated at an angle .alpha. by a light beam (19). The light beam (19) extends in a plane which contains the scanning beam and which lies parallel to but is displaced from the axis of rotation (17).

Abstract: In optical mark recognition apparatus the light transmitter has two light sources 11, 12 which can be selectively switched on and which transmit light beams of different spectral compositions. A semi-permeable mirror 15 directs the light beams 13, 14 of both light sources 11, 12 along a common optical path 16 (FIG. 1).

Abstract: A retroreflector consists of a support surface 12 coated with a layer 11 of small retroreflecting particles such as glass spheres. The support surface comprises a plurality of regularly repeating, alike, structural elements 13 which are inclined to the overall plane of the retroreflector. The surface elements 13 can be of various shapes and serve to increase the angular range over which retroreflection can occur. The optical characteristics of the proposed retroreflectors can be tailored so that they are eminently suitable for use in certain beam scanning applications such as continuous monitoring of doorways and windows by an optical beam scanning device located at one corner thereof in order to detect, for example, intruders.

Abstract: Light curtain apparatus incorporating a cyclical scale generator has a light transmitter 12 which projects a light beam onto an optical scanning device 13 located at the focal point of a strip-like concave mirror 14. As a result a parallel scanning light beam 20, which is continuously displaced parallel to itself, is produced in the image space of the concave mirror 14. The scanning light beam 20 is directed through a monitored region 17 towards a retro-reflector 16 and light returned from the retro-reflector 16 is passed via a beam divider 27 to a first light receiving device 18. In this way interruption of the light beam, for example by an object 31, results in interruption of the signal from the first photoelectric receiving device 18.

Abstract: An optical electronic distance sensor utilizes a V-light barrier in which a light transmitter 11 transmits a substantially parallel light beam 14 at a defined angle and a light receiver 12 receives a substantially parallel light beam 15 at a defined angle and delivers an electrical output signal dependent on the intensity of the received light beam. The distance of the intersection of the transmitted and received light beam paths, i.e. the apex of the V, from the light transmitter and receiver defines the sensing distance of the light barrier and is adjusted by adjusting the separation of the light transmitter and receiver. For this purpose the light transmitter and receiver are displaceably mounted on a mounting rail. The distance sensor is particularly useful in indoor carparks for determining the presence or absence of a vehicle in a parking space.

Abstract: A light transmitter directs light via a first polarizing filter, so that it is polarized in one plane, to a retro-reflecting device across a region to be monitored and the retro-reflector produces depolarization, or rotates the plane of polarization of the light, prior to directing it to a light receiver positioned adjacent the light transmitter. A second polarizing filter crossed relative to the first is positioned in front of the light receiver so that the light receiver will only recognize light whose plane of polarization has been appropriately rotated by the retro-reflector but not light reflected from a strongly reflecting object which interrupts the light barrier. Threshold circuitry evaluates whether a signal from a photoelectric convertor embodied in the receiver lies above or below a given threshold. Weakly reflecting objects are not recognized, because light reflected therefrom will be too weak to generate a signal above the required threshold. Various polarizing arrangements are described.

Abstract: A light grid arrangement features a row of light emitting diodes 0 to 9 which are periodically switched on one after the other by a ring counter 11 and are arranged to direct their light through a monitoring region 23 towards an image forming optical means which is conveniently in the form of a concave mirror 24. The light beams are concentrated by the concave mirror 24 onto a photodetector 18 arranged behind a slot aperture 25 located at the focal point of the concave mirror. Missing pulses from the photodetector are detected by processing circuitry 26 to indicate obstruction of the light grid. The width of the slot aperture 25 restricts the width of each individual light beam so that only beams of light from the light emitting diodes that are generally parallel to the axis of the concave mirror are detected. In this way costly optical focussing elements are avoided as are the difficulties of aligning these optical elements with the other optical components of a system.

Abstract: Colored markings such as a series of colored rings applied to an ampoule are read by causing the ampoule to move beneath an illuminating system which projects white light at the colored markings. Light reflected or scattered from the colored markings is directed at an aperture member arranged in the field of view of a color sensitive photoelectric detector arrangement and the image of the colored markings moves in a first direction across this aperture member due to relative movement of the object. The aperture member has a series of spaced apart optical apertures which are sequentially moved in a second direction transverse to the first direction and in front of the photoelectric detector arrangement. The photoelectric detector arrangement produces signals corresponding to the transmission of the image of the colored markings through the optical apertures.

Abstract: An optical apparatus for use in conjunction with spherically shaped concave mirrors for substantially eliminating aberrations in the reflections from such mirror. The mirror cooperates with a light source or a light receiver placed in the vicinity of but off-set relative to the natural focal point of the mirror. A plane parallel, transparent plate is placed between the mirror and the light source or receiver and it has a size so as to intercept light rays between the mirror and the light source or receiver and which respectively result in or are caused by light beams oriented parallel to the optical axis of the mirror. Use of the invention for additionally correcting astigmatism and chromatic aberrations caused by spherical mirrors is disclosed. Also disclosed is the use of the invention in connection with large spherical mirrors forming part of light curtain arrangements.

Abstract: A light barrier system for monitoring the presence or absence of an obstacle in the monitored area and for simultaneously monitoring itself to detect contamination of the system. A photo-converter emits signals indicative of the light intensity of a light barrier beam and the signal is applied to a first, obstacle switch which is normally open but which closes at a relatively high level of darkness, i.e. when an obstacle is present. A converter signal is also applied to a second, contamination switch which is normally open but which closes at a lesser degree of darkness than the first switch so that both switches can be simultaneously closed. The outputs of the switches when closed are applied to relays to switch the relays between alternative position to indicate (a) the presence of an obstacle in the light curtain area and (b) the contamination of the light curtain system irrespective of whether or not an obstacle is present.

Abstract: An electrooptical scanning device which can detect the relative position of register mark applied to a moving web, either serially on a single track or in two parallel, side-by-side tracks which extend in the direction of movement of the web. Light from a light source positioned some distance above the web is split into three light beams and the light beams are reflected downwardly towards the web. Lenses are positioned to receive and direct the light beam at an oblique angle onto the marks on the track or tracks. The lenses are aligned with the tracks and the light beam passing through a given lens is directed to the opposite track to illuminate three positions, two on the first track and one position on the second track. Light impinging on the web at these positions is scattered.

Abstract: Bottle color identification apparatus with a light beam passing through the bottle, in which the light beam passing through the bottle is supplied to a spectral decomposition arrangement which emits a signal characteristic of the bottle color.A special application of the invention is the sorting of returnable bottles having the same size and shape but different colors.

Abstract: A device for detecting the presence of an object in a region to be monitored of the kind comprising light emitting means, electronic light receiving means, and an optical system having means for focussing the light emitted by the light emitting means and means for focussing any light reflected by an object in the monitored region and passing to the light receiving means. The respective focussing means, which are preferably incorporated in a common block moulded from a light permeable material such as glass or plastics material, are so arranged relative to one another that the path of the light rays from the light emitting means and the path of any light rays passed to the light receiving means meet at an angle to one another in the region to be monitored.