Abstract: Apparatus for assessing the weld in a belt layer for a radial pneumatic tire in which the belt layer has been disposed onto a rotary drum, comprising an apparatus for directing at least one laser beam towards the drum and the belt layer, said laser beam being directed obliquely with respect to the perpendicular on the belt layer and the drum, and a camera for viewing the position of the projection of the laser beam on the drum and the belt layer.

Abstract: A reflection density measuring system comprises a light source for projecting an irradiation light onto the surface-to-be-measured of a sample and a photodetector which has a photosensor for detecting light reflected by the surface-to-be-measured of the sample to impinge upon the photosensor through a light receiving surface of the photodetector. The distance r between the center of the light receiving surface of the photodetector and the optical axis of the irradiation light is r.sub.o, the distance h between the center of the light receiving surface and the surface-to-be-measured as measured along the optical axis of the irradiation light is h.sub.o, and the angle .theta. which the light receiving surface forms with the surface-to-be-measured is .theta.o, h.sub.o being the value of h at which output I of the photosensor takes a peak value on an output curve representing the change of the output I of the photosensor with the distance h when the distance h is varied under the combination of r.sub.o and .

Abstract: An elliptical reflector illumination system for inspection of printed wiring boards including an elliptical reflector element for mounting above the board to be inspected with a region of the board generally at a first elliptical focus of the reflector element. There is a light source mounted generally at a second elliptical focus of the elliptical reflector element for illuminating substantially all facets of the region of the board at the first focus. One or more detectors are provided for sensing light reflected from the illuminated facets of at least a portion of the illuminated region of the board at the first focus.

Abstract: An apparatus and method for uniquely detecting pits on a smooth surface by irradiating an area of the surface; separately sensing radiation scattered from the surface in the near-specular region indicative of a pit and in the far-specular region indicative of a flaw and producing signals representative thereof; normalizing the near-specular signal with respect to the far-specular signal to indicate a pit; and discriminating the near-specular components of the normalized signal representative of surface pits.

Abstract: Device for detecting insipient cracks or tears on the edges (4) of a moving heet (5), of the type comprising:a light source (6),and a receiving cell for picking up the light transmitted by the source (6) through the sheet (5) moving between the source (6) and the cell,characterized in that:on the one hand, the light source (6) is a laser source;and on the other hand, the receiving cell (17) is an optoelectronic cell placed in such a way that the solid angle under which the serviceable surface of said cell (17) or of its image by an optical system, can be seen from the sheet, is less than 0.01 steradian.

Abstract: A system for measuring the weft or mesh serial position in textiles, in which the angular position of the weft/mesh series is measured for determining the angle of distortion passing over a partial amount of the length thereof, includes an illumination measuring system which measures values of light from a light source either passing through or reflected from the textile fabric to be tested, in a substantially linear range, and an adjusting assembly which reciprocally and oscillatingly rotates the linear range about a central angle to adjust the linear range at an angle relative to the textile fabric; rotating or measuring the reflection or transmission values in several discrete equidistant angular units; a group of memories for storing the measured values corresponding to at least a few angular units; and a digital unit connected to the memories for comparing the stored values in calculating a distortion angle in response to such comparison.

Abstract: A device for analyzing the characteristics of filamentary material while the filamentary material moves at high speed, and a method for using the device. The material is moved past a sensing array while a light shines against the array. The material will block the light to portions of the array; and, since the array is scanned by an electrical signal of high frequency, a width of the material will be indicated by the output signal. Successive scans, and successive widths, are stored in computer storage, and a profile of the material is constructed. Various statistical data can be computed, and a stop motion device can be activated in the event material is beyond preset standards.

Abstract: An apparatus and process are disclosed for examining a moving web of paper to determine the optical parameter of "formation" and the physical parameter of "roughness". The apparatus includes an optical system which forms an area of the web, with a first light source directing light through the moving web area from a back surface thereof, and a second light source directing light obliquely to the web area from the front surface thereof. A signal processing device determines the root-mean-square of the quotient resulting from the difference in received radiation from two spatially adjacent areas of the detectors divided by the sum of the received radiation from four spatially adjacent areas of said detectors to provide an output signal corresponding to formation or roughness of the paper web.

Abstract: A method of monitoring for contaminants in highly elongate textile product such as yarn includes diffusely applying light to the yarn and monitoring light reflected by the yarn. The yarn is drawn past a background therefor and light is diffusely applied to both the yarn and said background. The background is arranged so that the total amount of monitored light reflected from the yarn and the background is substantially independent of the dimensions and density of the yarn and of the distribution of constituents in the yarn. In this way, a prescribed change in the reflected light intensity indicates a selected contaminant or range of contaminants in the yarn. The background is conveniently provided by an elongate channel so as to be close behind and to each side of the yarn.

Abstract: A sheet discriminating apparatus comprising means for detecting both light reflected by and light transmitted through a sheet, upon irradiation of light onto the sheet; hole-detecting means for detecting whether or not there is a hole in the sheet on the basis of an output of the light-detecting means, the hole detecting means generating a signal when a hole is detected in the sheet; means for gating the output of the light-detecting means in accordance with the hole signal; and means for detecting the degree of soiling of the sheet in accordance with an output of the gating means. During operation of the sheet discriminating apparatus, when excess light is detected by the light-detecting means, the hole-detecting means outputs a hole signal, and in response to the hole signal the gating means selectively gates the output of the light-detecting means to the means for detecting the degree of soiling. If there is no hole in the sheet, it is then judged whether or not the sheet is fit or unfit for continued use.

Abstract: Apparatus and method for monitoring a moving web for structural defects at a plurality of independent locations across the width of the web, determining the location and magnitude of a detected defect and controlling movement of the web responsive thereto. A plurality of light sensing elements may be employed operatively connected to a microprocessor. A separate edge sensor may be employed and is claimed.

Abstract: The surface texture of a moving transparent film is determined by applying a beam of collimated electromagnetic radiation at an angle of incidence sufficient to produce detectable backscattered radiation; collecting the backscattered electromagnetic radiation while avoiding specularly reflected radiation; and evaluating the intensity of the collected radiation for two components, a first component corresponding to the haze percent of the film and arising from the scattering of the collimated electromagnetic radiation by microscopic and submicroscopic features of the film surfaces, and a second component produced by the scattering of the collimated electromagnetic radiation by macroscopic surface blemishes, gouges and gel-like particles on each surface of the transparent film.

Abstract: Printed webs leaving a printing press at speeds above 500 feet per minute are inspected with precision across the full width of the web by a stroboscope method and apparatus. Each repetitive image or design imprinted on the high speed web is rendered stationary relative to the eyes of a viewer at a web inspection station by bright short flashes of light emitted by an elongated xenon flash tube or tubes spanning the web transversely of its path of movement. Filtered light flashes are triggered by an improved strobe circuit which is synchronized with the press at all times and permits an inspector to produce from one to six equally spaced images per press cylinder revolution. Additionally, the system can be used in either an image lock mode for side-by-side comparison with a standard or in a controlled pan or scroll mode to allow optimal inspection of entire impression sequences. Also, when desirable, both sides of the web can be inspected by utilizing a second flash tube configuration located behind the web.

Abstract: A non-contact optical detector for on-line inspection of the surface of a wire during manufacturing is improved by an azimuthally symmetric sensitivity and by a time-dependent response that permits discrimination among flaws of different magnitude.

Abstract: Method and apparatus to measure the angle of pile lay to generate a signal which can be employed to automatically adjust another phase of the manufacturing operation to provide a desired pile effect on the fabric. Basically, the invention involves placing a light source on one side of the pile fabric and a light sensor on the other side of the fabric and varying the relative positions of the source and sensor to the pile on the fabric to obtain a measurement of optimum light transmittance.

Abstract: The present invention relates to an inspecting device for a print which can scan the entire print pattern of a printed sheet by an optical detecting device, detects the image information of the print pattern at every pixel, calculates the difference between the detected image information with reference information, delays the differential signal in several pixels in the scanning direction of the optical detecting device, calculates the difference between the differential signal and the delayed differential signal, sets a threshold level to the twice differential signal produced from the result, and judges the production of a printing defect when the twice differential signal exceeds the threshold level, thereby accurately detecting the printing defect even when the entire variation in the color density occurs on the printed sheet.

Abstract: 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).

Abstract: Images of successive portions of a surface of a strip are formed and converted as analog signals. Signals typical of each image are stored in an image storage whereas the analog signals relating to each image are converted in numerical form by splitting up the image into image elements. Each of the image elements is given a numerical value, and then filtered, in order to sense the relative variations of the numerical values of the image elements. To determine whether or not to deliver a defect-sensing signal in terms of the sensed variations, the filtered signal is scanned. The typical image is stored in response to the transmission of the defect signal. Every read-in information is stored and displayed at a check station long enough for a visual check of the image it represents.

Abstract: An apparatus using optical techniques for simultaneously detecting surface defects and measuring the diameter of a wire coming out from an extruder. A combination of cylindrical lenses is used for projecting, perpendicularly across the longitudinal axis of the wire, a sharply focused laminar beam. This apparatus includes an optical source system for emitting optical rays, an optical system for focusing the rays on the wire, an optical detector system for receiving the rays and generating a detector signal to be processed by a signal processing system, the processing system generates an electric signal indicative of the amplitude of the defects and another electric signal indicative of the diameter of the wire.

Abstract: An optical sensing system that detects the angular orientation of weft threads in a moving web of a textile has a sensor array that receives light transmitted through the web from a light source. The sensor array is preferably a single monolithic chip that includes a radial pattern of photosensitive areas that each generate an electrical signal proportional to the total intensity of the light incident on the area. The areas are elongated and narrow so the moving shadow of a weft thread passing over the area will modulate the output signal. The modulation is strongest when the thread is generally aligned with the area. Electronic circuitry generates a DC signal associated with each area that is proportional both of the magnitude and frequency of the modulation of the signal. The circuitry also compares these signals, selects the largest one, and generates an analog output voltage characteristic of the area associated with the largest signal.

Abstract: A motion picture film flaw detection system wherein a single inspection location is employed at which sound track side edge defects, sprocket hole side edge deflects, thickness variations, and defective sprocket holes are analyzed by optical sensors so that no physical contact on the film by feeler arms or the like occurs. Film wear such as by scratching and rubbing is reduced since minimal contact occurs with a surface of the film as it travels through the system. The sprocket holes are analyzed by optics which provide a real image on a projection plane at which location excessive elongation of the sprocket holes is checked. Detection circuits are provided connecting to the optical sensors which derive a reference which automatically tracks averaged or weighted overall signal levels for comparison to signal variations caused by film thickness changes or film flaws. Accordingly, variations in optical system performance are automatically compensated for.

Abstract: A motion picture film flaw detection system wherein a single inspection location is employed at which sound track side edge defects, sprocket hole side edge defects, thickness variations, and defective sprocket holes are analyzed by optical sensors so that no physical contact on the film by feeler arms or the like occurs. Film wear such as by scratching and rubbing is reduced since minimal contact occurs with a surface of the film as it travels through the system. The sprocket holes are analyzed by optics which provide a real image on a projection plane at which location excessive elongation of the sprocket holes is checked. Detection circuits are provided connecting to the optical sensors which derive a reference which automatically tracks averaged or weighted overall signal levels for comparison to signal variations caused by film thickness changes or film flaws. Accordingly, variations in optical system performance are automatically compensated for.

Abstract: On-line apparatus for analyzing the formation of a moving web of paper, using a source of light directing a beam through the paper and a photodetector receiving the light which has passed through the paper, has a circuit preferably including a tunable band pass filter and demodulator producing a D.C. output reflecting size and distribution of flocs. The output gives similar results to those obtained by visual judgement of formation.

Abstract: A system for measuring the energy transmission through a moving aperture pattern includes a CCD (charge coupled device) sensor having at least one row of pixels arranged perpendicular to the direction of motion. An encoder responds to the motion and provides count pulses. For each count pulse, specific pixels are addressed to establish a plurality of inspection areas for the aperture pattern through which energy transmission is measured. The transmission is averaged for all the inspection areas to determine the acceptability of the aperture pattern.

Abstract: A boundary or line-detecting process using image-filtering is used to detect fabric faults in moving textile fabric webs. A double-slit mask or an electrical equivalent thereof is used as a filter. The output signal of the filter is formed from the difference between the two luminosity values averaged across each slit of the filter mask. The image-filtering system is realized either by non-coherent optical spatial filters or by means of digital electronic circuits. The surface of the fabric web generally has a certain texture which already contains boundary and line elements. These basic values are used to derive fabric-specific parameters from which the boundary or line elements due to fabric faults are deducted. The boundary or line elements which remain, owing to their increased contrast, unambiguously indicate faults in the fabric web.

Abstract: A two-stage light collector, including a first stage which admits a scanning beam and a second stage which is optically connected to the first stage and has a light detector therein. The first stage has a shape which re-images diffusely scattered radiation from a target on which the radiation impinges. The first stage directs light toward an entrance aperture in the second stage which indirectly reflects light toward the detector associated with the second stage.

Abstract: The present invention relates to an inspection apparatus for detecting the surface distortion in a sheet of material such as a sheet of glass, for example, and for indicating whether the level of distortion detected in the inspected sheet is unacceptable. The inspection apparatus includes a light source mounted to direct a first beam of light toward one surface of the sheet at an oblique angle of incidence to cause a second beam of light to be reflected therefrom. A light detector is mounted to receive the reflected beam and is responsive to a light pattern produced by the reflected beam of light for generating an output signal representing the width of the light pattern. The width of the light pattern is a function of the surface distortion of the portion of the surface from which the beam is reflected. A control circuit is responsive to the detector output signals for generating an actual distortion signal representing the amount of surface distortion in the inspected portion of the surface.

Abstract: A method and apparatus for monitoring the surface of an elongated, normally-smooth object, such as coated cable, for certain flaws. The object is longitudinally movable along a path. Radiation, such as white light, is directed at the object such that it is incident therewith throughout a narrow zone extending substantially entirely around the object's perimeter. The angle of incidence of the light with the object is such that a normally smooth surface specularly reflects light at a relatively large angle, whereas particular flaws, such as pips and the like, scatter the light in a particular direction longitudinally of the object and at a relatively smaller or limited angle thereto. A slotted mirror is disposed concentrically about the object's path and reflects the scattered light to imaging and detecting devices, such as a charge injection device. Analytical electronics connected to the detector analyze its electrical signal to indicate the presence of a flaw.

Abstract: An apparatus for automatically detecting and evaluating print characteristics comprising an optical detection and comparison means. In particular comparison is made using reflector means which is at the same time a background area for a print in its test position.

Abstract: In an optical detection system for detecting a feature located at a predetermined lateral position on a banknote, for example, the banknote is moved along a flow path and a series of light receivers are arranged transversely across that portion of the flow path which the feature is expected to occupy, so that different ones of the light receivers will respond to the feature in the banknote depending on the lateral offset of the banknote at that portion of the flow path. The margins of the note are utilized in the detection system to gate the said light receivers so that for any position of lateral offset of the banknote only that light receiver which responds to the said feature of the banknote will produce an effective output signal. In the embodiment of FIG. 1, two sets of fibre optics are used to effect this gating, one set having its first ends (S1 to S5) opposite a light source at one margin of the sheet and its other ends (F1 to F5) adjacent the above mentioned light receivers (F1' to F5').

Abstract: A method and apparatus for inspecting substrates such as flat textile fabrics which have been sculptured to a depth of less than about 0.003 inches. Opposing line sources of illumination are used to illuminate the substrate at a relatively low angle while the substrate is held flat in front of a dark, non-reflective background and is substantially shielded from ambient light.

Abstract: Apparatus for detecting missing areas or folded corners in sheets, for example banknotes (14), is disclosed. FIG. 1 shows a banknote (14) being scanned in a strip along one edge of the banknote. A strip light source 12 and a strip sensor 16 are disposed on opposite faces of the banknote which is caused to move perpendicularly to the light path between the source and sensor, and perpendicularly to the plane of the drawing. A photometer (18) responds to the total amount of light transmitted through the edge strip of the banknote (14) as the banknote is scanned. A filter (20) may be interposed in the light path to improve the sensitivity of the apparatus. The total amount of transmitted light detected by the photometer (18) is integrated over a period of the scan during which the intensity differs substantially from the mean level for an unflawed portion of the banknote. Integration is thus performed only over missing or folded areas of the banknote.

Abstract: A method of and apparatus for controlling apparatus for perforating strips of paper by disruptive spark discharges. The perforate strip passes between two chambers, each of which has an opening facing the strip. Waves transmitted by a transmitter disposed in one of the chambers pass through these openings. The other chamber contains two receivers. The waves which have passed through the perforations are incident on one of the receivers. The waves which have passed through the imperforate area of the paper are incident on the other receiver. The perforating apparatus is controlled in dependence on the difference between the actual and desired values of the difference between the output signals of the two receivers.

Abstract: The present invention relates to a method for checking flat transparent surfaces permitting the discrimination between the flaw in the matter and dirt which has been deposited on the surface but does not affect the flatness or the transparency of the sheet. The apparatus includes a photosensitive captor located above the sheet to be checked. The captor is arranged at the limits of a fuzzy real image which an optical system gives in the plane of this captor of a light source located below the sheet. In this way, a flaw causes the excitation of the captor at a level higher than the normal light threshold of the fuzzy image because of refraction caused by the flaw in the matter. In contrast, the presence of dirt will cause, through occultation, an excitation lower than the normal light threshold thereby enabling differentiation between the flaw and the dirt.

Abstract: A method and apparatus is provided for determining the presence or absence of a coating on a substrate. The substrate is placed into optical contact with a light guide and the principle of frustrated total internal reflection is utilized. Light scattered from the coating surface is monitored to indicate the presence of a coating and failure to detect scattered light indicates the absence of said coating.

Abstract: An optical sensing system that detects the angular orientation of weft threads in a moving web of a textile has a sensor array that receives light transmitted through the web from a light source. The sensor array is preferably a single monolithic chip that includes a radial pattern of photosensitive areas that each generate an electrical signal proportional to the total intensity of the light incident on the area. The areas are elongated and narrow so the moving shadow of a weft thread passing over the area will modulate the output signal. The modulation is strongest when the thread is generally aligned with the area. Electronic circuitry generates a DC signal associated with each area that is proportional both to the magnitude and frequency of the modulation of the signal. The circuitry also compares these signals, selects the largest one, and generates an analog output voltage characteristic of the area associated with the largest signal.

Abstract: A surface inspection system utilizes a laser light source, and a vacuum chuck to support the material whose surface is to be inspected. The vacuum chuck is rotatable. The laser beam may be translated across the work surface while the chuck is rotated, all the while maintaining mutual perpendicularity of the vacuum chuck work surface and the laser beam. An airtrack transports the material whose surface is to be inspected. Sensors are utilized to detect the position of such material along the track and to guide the system in its operation.

Abstract: An optical paper detector for use in conjunction with a printing press for sensing the undesirable condition of more than a single sheet of paper being simultaneously fed to the press. The optical paper detector is comprised of an array of wide angle phototransistors connected in parallel which uniformly sense light transmittance through the paper over a relatively large and continuous area to provide an averaging effect so that the optical paper detector is relatively insensitive to local variations in light transmittance. The optical paper detector is equipped with a flat cover that permits flush mounting and provides a self-cleaning wiping action.

Abstract: A technique for automatically centering a lightguide fiber (7) in a transparent plastic coating (6) having a refractive index lower than that of the fiber. The fiber (7) is passed through an applicator (14) having the coating material (6) therein to coat the fiber. Orthogonal laser beams (50 or 52) are directed at the coated fiber (5) resulting in first and second forward scattered light patterns (51 or 53) impinging on first and second screens (36 and 37). The patterns are monitored with a pair of CCTV cameras (38 and 39) and the video output signals therefrom are processed to determine the period (P.sub.1 and P.sub.2) of outboard interference fringes (61 and 62) of each pattern. The period of the interference fringes are compared to determine the difference therebetween which is proportional to the eccentricity of the fiber (7) within the coating. The position of the applicator (14) is then adjusted to center the lightguide fiber (7) in the coating (6).

Abstract: A system for electronically inspecting fabric for defects wherein a moving fabric is scanned by light sensing apparatus for variations in light reflecting characteristics due to the presence of a defect. The sensitivity of the system is monitored by an automatic background control circuit to adapt the system to the light reflective characteristics of the particular fabric being inspected and alarm and defect counting apparatus indicates and records the presence of a defect. The system permits the inspection to be terminated upon the detection of a defect, or alternatively, the quality of the fabric can be determined by recording spaced defects during successive defect recordable time periods, the duration of such time periods being adjustable.

Abstract: An optical sensing system that detects the angular orientation of weft threads in a moving web of a textile has a sensor array that receives light transmitted through the web from a light source. A first lens system forms a converging light beam of generally uniform intensity directed at a normal to the web. A second lens system focuses the portion of the beam transmitted through the web onto the sensor array. Both lens systems can each consist of a single, circular, plano-aspheric lens. The second lens is preferably movable with respect to the sensor array to adjust the magnification of this system and has a low f number. The sensor array is preferably a single monolithic chip that includes a radial pattern of photosensitive areas that each generate an electrical signal proportional to the total intensity of the light incident on the area. The areas are elongated and narrow so the moving shadow of a weft thread passing over the area will modulate the output signal.

Abstract: A device for detecting surface flaws of rapidly moving metal strip in rolling mills includes a lens which scans the sheet material surface and a camera tube which converts optical images of the lens into electrical values. These values are stored in a magnetic storage and are called out to be converted and displayed on an image reproducing device as a visible image. At least one image amplifier or image converter tube is interposed between the lens and the camera tube and includes an electronic speed shutter.

Abstract: In general, used beer, alcoholic drink, soft drink or medical bottles are collected to be used again. Such used returnable bottles often have foreign matters or contaminants such as dust and leavings or cracks, and they must be removed from the bottling line before or after the bottle cleaning process. This invention positively satisfies such a requirement. The foreign matter detecting device comprises: a photoelectric conversion device having a number of light receiving elements; and a video signal processing device for successively subjecting to comparison and discrimination the detection signals of variable two adjacent points which are detected by the photoelectric conversion device, to determine whether or not the bottle has a foreign matter.

Abstract: The surface character of flexible materials is examined by means of interference fields which are formed by reflection of light beams from a reflecting reference surface and from the adjoining surface to be examined, and subsequent super-position of the partial beams thereby formed. The interference field which corresponds to the surface profile standing out from the reference surface is utilized to determine the length and height of the surface profile, with the aid of the interference band spacings and the wavelength of the incident light.

Abstract: Apparatus and method for optically scanning the circumference of a generally circular section of a test object, and especially for monitoring the surface character of cables and the like. An optical system has its apparent axis substantially concentric with the centerline of the path along which the cable moves relative to the scanning optics. A beam of radiation is caused to rotate or orbit about that axis and is then directed into near-normal incidence with the surface of the test object such that it is specularly reflected by the surface. The optical system redirects the reflected beam toward one or more detectors, the intensity of outputs of which provide an indication of the surface character of the object.In a preferred embodiment, a radiation source beam offset from the actual cable path is rotated by a pair of oscillating mirrors such that it describes a divergent conical shape. Certain optics direct a 180.degree. portion of that rotating beam along one path to intersect with a corresponding 180.

Abstract: A device for detecting surface unevenness by the utilization of reflected light of wires having a covering of light-transmissive insulating material such as enamel. Light is projected onto the wire-shaped material and is received therefrom by means of glass fibers. The incident angle of light applied to the insulating material is selected to be larger than the critical angle of the material. A rod lens is provided for each glass fiber in such a manner that the longitudinal axis of the rod lens is orthogonal to the longitudinal axis of the glass fiber. A light shielding board is disposed between the light projection side and the light receiving side so that only light reflected by the surface of the wire-shaped material is received whereby the surface unevenness of the insulating material layer is detected without being affected by scratches or defects on the wire conductor.

Abstract: Method and apparatus for inspecting threaded objects and for determining the depth of blind holes. For inspecting threads, a light source is provided for illuminating threads of a threaded object. A lens forms an image of the illuminated threads. A detector having a light sensitive area sufficiently small to resolve the thread image is provided to detect the image and an output signal is produced in response to the incident image light. The output signal is analyzed to determine the quality of the threads. For determining the depth of a blind hole, a light source forms a spot on the bottom of a blind hole in an object and the lens forms an image of the spot. Means are provided to detect the spot image to produce an output signal responsive to the incident image light. Means are provided to analyze the output signal to determine hole depth.

Abstract: Documents are caused to pass in front of a light source incorporating optical fibres and the reflected light is collected by means of photoelectric elements. The collected reflected light is compared with a reference value. A row of photoelectric elements is used which successively transmits, by multiplexing, the signals delivered simultaneously by a row of the photoelectric elements. The analog signals are converted into digital signals, and a totalling and averaging of the digital signals is carried out in order to determine the state of general dirtiness of the document. The number of photoelectric elements of the row covered by the document is counted to inspect the width of the document and detect the presence of dog ears. In addition the number of photoelectric elements delivering a signal which exceeds a certain level is counted.

Abstract: Light beams directed toward each surface of a sheet are reflected therefrom as first reflected light beams and second reflected light beams. The intensity and/or density of the reflected light beams are acted on to compare the reflectivity of the sheet surfaces, e.g. to determine which surface of the sheet has a more reflective surface.

Abstract: System for the analysis of an optically sensed field, useful, for example, for detecting defects in an object such as a shadow mask of a color kinescope, which permits relatively rapid examination of the article or surface being scanned. An important feature of the system is a detector linear array disposed a selected distance from the image plane of the spatial field permits higher speed sequential convolution of the spatial field at each of a plurality of overlapping segments of given length, situated at uniformly-spaced intervals along a field dimension, with a given type of limited spatial extent kernel function of said given length.