摘要:
Hole seeking apparatus for material webs is disclosed which features a light source for projecting a light beam onto a mirror wheel arrangement located optically in front of a concave mirror so as to produce a scanning beam in the image space of the concave mirror. The scanning beam is continuously displaced parallel to itself so as to periodically scan along a scanning path on the material web. The mirror wheel arrangement consists of two substantially identical mirror wheels which lie coaxially on one another and which are displaced by a half pitch.The dimensions of the light bead at its point of incidence on the mirror wheels and the optical geometry of the apparatus are selected to avoid light being scattered at an edge of either of the mirror wheels and passing to either side of the web. Scattered light is thus prevented from falling on a light receiving device arranged behind the web and intended to detect the presence of holes therein. In this way the false recognition of a hole at the margins of the web is prevented.
摘要:
A banknote condition monitoring apparatus features a mirror wheel (22) located substantially at the focus of a concave mirror strip (25) with an intervening plane mirror (26) to fold the beam path. The mirror wheel (22) scans an incident light beam from a source (28) to form a transmitted light beam in the image space of the concave mirror (25) which is continuously displaced parallel to itself to and fro through the image space. The transmitted light beam is directed via a cylindrical lens (14) onto the surface of a drum (11) carrying the banknotes (12) to be monitored on its peripheral surface by way of air suction via the channels (32). Light remitted from the surface of the banknote is directed through the lower half of the cylindrical lens (14), impinges on a light conducting rod (15) and is detected at an and face of the light conducting rod by a light receiving device (33). The mean output signal from this light receiving device indicates the presence of holed, torn or dog-eared or dirty banknotes but not strips of clear adhesive film which are recognized by the specularly reflected light beam (21) which falls on a stationary photodetector (23). The optical distance of the stationary detector (23) from the drum is equal to that of the mirror wheel scanning device so that the specularly reflected light beam always passes through a stationary point in space.
摘要:
A light beam 2 from a laser light source 30 is split by a beam splitting arrangement 21, 22 into two slightly convergent light beams which are deflected by a deflecting mirror 31 onto the surface of a mirror wheel 23. The mirror wheel 23 that deflects these light beams via deflecting mirrors 24', 25' onto two strip-like concave mirrors 24, 25 which produce respective parallel scanning light beams which are continuously displaced parallel to themselves in the image spaces of the strip-like concave mirrors. These scanning light beams fall on respective rows of inclined dividing mirrors 9 and 10 which are arranged one behind the other in an alternating sequence. The inclined mirrors deflect the incident light beams through substantially 90.degree. to form a continuous light curtain which can be used to scan web material. Light reflected from the surface of the web or transmitted through holes in the web falls on light gathering devices in the form of either two rows of strip-like Fresnel lenses 5, 6 or two rows of light conducting rods 5', 6'. One light gathering device is associated with each of the inclined mirrors 9, 10. Light gathered by each of the light gathering devices is directed to an associated photoelectric detector 7 which is connected to an electronic processing circuit 8 for evaluating the signals from all the photoelectric detectors.
摘要:
A laser beam scanning device (17) is provided for monitoring for thread breakage in tufting machines (31) in which a carrier web (16) is passed from below to a spiked roller (11) and is deflected by the spiked roller into a substantially horizontal direction so that it can be passed beneath a row of needles (12). The row of needles (12) periodically introduce threads into the carrier web (16) by up and down movement in order to form tufted material. A narrow retro-reflecting strip (14) is arranged directly below and behind the tips of the needles and directly above the tufted material (15) parallel to the row of needles (12) and substantially at right angles to the surface of the tufted material. The scanned light beam (18) is regularly interrupted by the threads which pass through the needles (13) when the needles are in the elevated open position and, after reflection at the retroflecting strip (14) and other optical elements, is received by a photoelectric receiver (19) where it generates an AC output signal. If one of the threads is broken then the scanning beam (18) is not interrupted at this position and this is recognised in the output signal from the light receiver (19).
摘要:
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.
摘要:
A fault seeking apparatus for detecting faults in carpet webs (15) has a first main mirror wheel (17) which is illuminated by a laser beam (18) and which generates via a concave mirror (13), a scanning beam (14) which is periodically displaced parallel to itself. This scanning beam is directed at an angle to several subsidiary mirror wheels (11a to 11i) which are arranged alongside one another, which rotate substantially faster than the main mirror wheel (17) and which generate a scanning light strip on the carpet web (15). A light receiving device consisting of lenses (20a to 20i) arranged alongside one another and a light conducting rod (22) with a photomultiplier (23) at one end face is arranged on the other side of the carpet web (15) (FIG. 1).
摘要:
Apparatus for combining light emanating from a linear scanning field on a relatively small receiver via an optical arrangement producing a scanning light spot with a light ray scanning device onto which a light beam impinges, the arrangement further having optical elements of the transmitting beam of rays located in front of the light ray scanning device, a transmitting concave mirror and a receiving concave mirror extending in the scanning direction, and a cylindrical lens parallel to the scanning field and extending in the vicinity of the latter, the transmitting and receiving beams of rays being separated by pupil separation. There is further provided plane mirrors arranged between the concave mirrors and light ray scanning device for bending the receiving beam of rays perpendicular to the scanning direction and in the direction of the intersection point of the optical axis of the transmitting beam of rays located on the light ray scanning device by such an amount that it still strikes the light ray scanning device, but passes beside the optical elements. The curved surface of the cylindrical lens is ground planar in the area of the entry of the transmitting beam of rays, and the receiving concave mirror is displaced relative to the transmitting concave mirror in the sense of shortening the optical path of the receiving light.
摘要:
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.
摘要:
An optical fault seeking apparatus has a light scanning apparatus (21) and a light line receiving apparatus (14) which receive the light reflected from the material to be investigated and direct it onto a photoelectric converter. The light beam which forms the light line 11 impinges at an acute angle (.alpha.) onto the surface (13) of the article or web (18) under investigation. The image forming optical light line receiving apparatus (14), effectively consists of two light receivers (14, 14') positioned away from the normally reflected beam (23) and arranged to receive light from respective ones of two spaced apart strip-like regions (11', 11") extending parallel to and partly overlapping the line of light (11). In this way the device is able to detect faults (e.g. lumps or depressions) in fleece-type webs with irregular surface structures which are normally very difficult to monitor with optical fault seeking apparatus (FIG. 1).
摘要:
A fault detecting apparatus for flat articles generates a line of light on the article which is imaged onto a photoreceiver via an optical system having cylindrical imaging characteristics. For use with an article 11 having light diffracting characteristics the line of light 12 is arranged substantially at right angles to the structure 13 which causes the light diffraction. The optical system 14 having cylindrical imaging characteristics detects, apart from the zero order at least also the first diffraction order of the light leaving the article. The light of the first diffraction order is also imaged onto its own photoreceiver (FIG. 1).