Abstract: An autocollimation light curtain comprises a light source which directs a light beam onto a scanning device which scans the light beam so that it is continuously displaced parallel to itself, thus forming a light curtain which is directed through a monitoring region. A reflector is provided at the end of the monitoring region and is subdivided in the scanning direction into a plurality of fields of two types which alternate with each other. Light reflected at the reflector is directed back to a light receiving system comprising first and second photodetectors. The two types of fields of the reflector have characteristics which influence the spectral range and/or the state of polarization of the incident light. In the light receiving arrangement one photoreceiver is filtered so that it receives only light reflected from the one type of field, but not light from the other type of field, whereas the other photoreceiver responds to all the light reflected back from the reflector.

Abstract: A method and also an apparatus is described for the direct optical detection of the roughness profile of the material surface (10) in which a light bead (14) is generated on the material surface (10) and the reflected light is passed to a light receiver arrangement (16). The angle of reflection of the reflected light and thus the respective surface inclination value is determined for each scanned point of the material surface (10). To determine the angle of reflection the direction of the center of gravity of the scattered reflected light is formed in each case. The desired roughness profile is subsequently reconstructed from the inclination values that are obtained.

Abstract: The scanner has a light transmitter (10) which radiates light onto a rotating mirror (12) for linewise scanning of an article (20). The mirror wheel (12) has mirror surfaces (1, 2, 3, 4, 5, 6) with different inclinations relative to its axis of rotation which project the light in parallel scanning lines onto the article (18). The light scattered back from the article (20) is picked-up by an optical system and transferred to a photodetector (30). The output signal of the photodetector (30) is stored after analogy-digital conversion in a memory (1", 2", 3", 4", 5", 6"). A pre-evaluation stage with a programmable module (32) accesses the memory (1", 2", 3-, 4", 5-, 6"), identifies the signal component originating frOm a bar code and transfers it to a second memory (38) which has a substantially smaller memory width but however a substantially larger memory depth.

Abstract: A hydroculture has a feed solution tank 11 from which feed solution is supplied to the plant roots by capillary action or pump action. Feed tubes 12 of a hydrophobic microporous material which is water vapor permeable but not water permeable are laid in this feed solution tank 11, and salt water having a substantially elevated temperature relative to the feed solution is led through the feed tube 12. In this way the used-up feed solution is replaced by desalinated water.

Abstract: An optical web monitoring device is described for which a directed illumination is realized by means of a mirror strip which fully illuminates the pupil of the camera objective of a diode row camera with the image of the illuminating pupil. All contrasting methods can thus be used also for the finding of surface faults in running webs. Several cameras or one camera with pupil division and two diode rows can be simultaneously illuminated using one illuminating device.

Abstract: An optical scanning apparatus for plane surfaces (13) having a laser light source (20), a light deflecting means (16) illuminated by the laser beam, a telecentric image forming element (15) and a light receiving means. Parallel to the scanning line (11) generated by the light deflecting means (16) and the telecentric image forming element (15) there is arranged, at the angle of regular reflection, an image forming retroreflector (12; 38,39) which forms an image of the light bead running along the scanning line (11) on itself.

Abstract: An optical scanning apparatus for transparent, substantially flat material comprises a light source (21) and a mirror wheel (22) illuminated by the light beam. The mirror wheel generates a scanning beam which executes a periodic scanning movement in a scanning plane extending obliquely to the surface of the material. The scanning beam generates a scanning light bead on the surface of the material with the scanning light bead moving along a scanning line. A photoelectric light receiving device is arranged at the angle of reflection. The plane of incidence (11) is arranged at the Brewster angle relative to the normal (12) to the surface of the material (13) The light of the scanning beam (14) which executes the periodic scanning movement in the scanning plane (11) is linearly polarized parallel to the surface of the material or perpendicular to the scanning plane (11).

Abstract: An optical surface inspection apparatus for material webs comprises an illuminating means (11) for generating a strip of light (12) on the surface (19) to be inspected and a light receiving means (13) which receives the light emitted (diffusely reflected) from the surface region illuminating by the strip of light (12) and directs it to a photoreceiving arrangement, which delivers a signal representative of web faults to an electronic processing circuit (16). The light receiving means (13) has at least one row camera (14) which receives light remitted from a line illuminated by the strip of light (12) and forms an image of the line on the diode row (15). The light receiving means is also arranged at such a shallow observing angle .alpha. relative to the tangential plane to the surface at the location of the strip of light (12) that faults (20) which project slightly out of the surface appear to the row camera (14) in shadow outline against the light background of the strip of light (12).

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: In a machine having automatic article transport individual identical articles are conveyed along a conveyor path (21) past various processing stations. A clock (12) is associated with the conveyor path. Furthermore, a characteristic detection apparatus (13) is provided which delivers information corresponding to the characteristics of the articles (16) which are moving past to a characteristic shift register (11), which is pulsed by the clock (1). An article sorting apparatus (14) is arranged spaced from the characteristic detection apparatus and is controlled by the associated storage (11') of the characteristic shift register. A further presence shift register (15) is arranged parallel to the characteristic shift register (11) and the information contained in the presence shift register (15) is compared with the output of a presence detection apparatus (17) and can be used to stop the machine in the event that a deviation is detected.

Abstract: The sharply bounded entry pupil (13) of an optical web monitoring apparatus is imaged by the system after passage through or reflection at the material web onto a dark field stop (16). This stop is provided at its periphery with light receiving surfaces having a relatively small area relative to the extent of the dark field stop (16). These light receiving surfaces conduct the received light to a photoconverter arrangement which is connected to an electronic processing circuit. In this way material faults are detected which bring about only small angular deviations of the scanning beam. In order to detect faults with greater light scattering a multiplier (23) is additionally mounted behind this receiver arrangement and receives light deflected beyond the light receiving surfaces.

Abstract: A surface waviness measuring apparatus for specularly reflecting surfaces has a light source (22) and an optical system (23) which directs a light beam (24) obliquely onto the surface (14), with the light beam (24) forming a small primary light bead (12) there. A spherical concave mirror (11) is arranged at the angle of reflection (.alpha.) with the center of curvature (13) of the spherical concave mirror being arranged closely adjacent the small primary light bead (12) on the reflecting surface (14). A photoreceiver arrangement (16) is located at the angle of reflection of the light beam (15) reflected from the concave mirror (11).

Abstract: A light curtain apparatus is described which does not require a mechanically moving light deflecting element such as a mirror wheel. Instead a number of diodes (11') are arranged in a row (11) and are sequentially energized so that light from each diode in turn passes through an objective lens (12) and an aperture diaphragm and falls on a strip-like concave mirror (14). The diode row is arranged at the focal plane of the objective (12) so that the light emerging from the objective (12) is essentially parallel light. The aperture diaphragm is located in the focal plane of the strip-like concave mirror so that the parallel light emerging from it is reflected at the strip-like concave mirror (14) in a direction parallel to the optical axis (19) and focussed in a plane corresponding to the plane of the aperture diaphragm (20) which is also the focal plane of individual lenses (16') arranged in a row within the image space of the strip-like mirror (14).

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: A telecentric image forming system for a linear zone on the surface of an object comprises a diode row camera with a telecentric imaging system at the object side. In the present embodiment the pupil of the normal, non-telecentric, camera objective (15) is arranged in the focal plane of a spherical concave mirror strip (13) which lies parallel to the direction of the diode row (16). Furthermore, the concave mirror strip (13) and the camera objective (15) jointly form the image of the linear zone on the diode row (16). With this arrangement relatively long linear zones can be illuminated without the need to provide a telecentric camera objective with a diameter substantially equal to that of the length of the zone.

Abstract: The solar mirror apparatus has an elongate support frame on which resiliently flexible sheet metal mirrors (15) are secured in a parabolically curved arrangement, with an elongate solar radiation receiver (28) being mounted at the focal line of the sheet metal mirrors (15). The support frame is swivellable about an axis which extends parallel to the focal line of the parabola. The carrying frame has two spaced apart clamping section supports (11) disposed opposite and parallel to one another. The mirror plates are carried by parabolic webs (13) with the mirror plates being fitted shapewise on the parabolic edges (17) of the parabolic webs (12). The ends of the parabolic webs (12) which extend between the clamping section supports (11) are swivellably supported at the confronting sides of the clamping section supports (11) about swivel axes (14) which extend parallel to the longitudinal axes (13) of the clamping section supports (11).

Abstract: A reflection light barrier has a light transmitter/receiver (14) having two adjacent front lenses (18, 19) for the transmitted and received light respectively. A triple reflector (13') is arranged at the end of the light barrier path and consists of a plurality of individual triples. In accordance with the invention the length of the boundary line (12) between the pupils is curved so that on arranging the triple reflector (13, 13') in the near range of the light transmitter/receiver the quantity of light which enters into the receiver pupil (16) as a result of the triple displacement (V) corresponds essentially to the quantity of light received when the triple reflector (13) is arranged in the far region.

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 light sensor with a housing (19) the light transmitter (17, 20) and the light receiver (12, 15) are arranged alongside one another. The received light beam (11) is deflected behind the front receiving lens (12) onto a photoelectric converter arrangement (15) via a deflecting mirror (14) which is pivotable about a transverse axis (13) and it is possible to change the sensing distance by pivoting the deflecting mirror (14).