Abstract: A linear array of photoemitters and photodiodes are positioned on opposite sides of currency paper for denomination and verification determination under transmitted light. The photoemitters are arranged for projecting an image of the indicia printed on the security thread embedded within the currency paper. The photodiodes receive the image and connect with a processor circuit which determines the presence or absence of the security feature, reads the denomination indicia and correspondingly provides indication thereof. The processor contains stored information identifying currency denomination and a comparison is made at the time of verification to also determine the denomination of the proffered currency.

Abstract: A two-dimensional image sensor 12 having openings 28 through which light can pass is formed on a transparent substrate 21 and combined with a planar light source 11 and an optical element 13 which defines optical paths. The optical element 13 is formed by combining one of a diffraction grating, a microlens and a specular surface of V-shaped grooves with a collected fiber member formed from bundled optical fibers having light shielding side faces so as to allow the transfer of an image. The profiles of these components are determined so that light may be focused upon a finger contacting area on the center line between the openings 28 and photo-sensitive elements 24 of the sensor 12.

Abstract: A photodiode and a phototransistor are positioned on opposite sides of a document subjected to verification for authenticity under transmitted light. A logic circuit determines the presence or absence of the security feature and correspondingly provides visual or audible indication thereof. The photodiode, phototransistor and related circuitry are arranged within an enclosure that is attached to a currency receiving device such as a cash register. The visual or audible indicators are mounted on the cash register for immediate indication of the currency verification to the cashier. A simplified capacitive proximity sensor can be employed, per se, for inexpensive applications or for redundant verification in combination with an optical detector. The shape of the capacitive sensor is configured to that of the security thread to discriminate between the security thread and the currency paper. Additional optical circuits are employed to detect counterfeit markings on the currency surface.

Abstract: An irregular pattern input device includes an optical fiber bundle in which an entrance surface and an exit surface are respectively formed at both ends thereof. Lighting means emits irradiation light so as to provide a light pattern according to a convex portion of a subject in contact with the entrance surface, and according to a concave portion of the subject in no contact with the entrance surface. In this case, an angle of incidence of the irradiation light is set to be larger than a critical angle on an interface between a core portion of each optical fiber of the optical fiber bundle and the air. It is thereby possible to provide total reflection on the entrance surface in no contact with the concave portion of the subject, and non-total reflection on the entrance surface in contact with the convex portion of the subject, resulting in reflected light having a light pattern according to an irregular pattern.

Abstract: A linear array of photodiode and phototransistor pairs are positioned on opposite sides of currency paper for denomination determination under reflected light and for verification determination under transmitted light. The focus of one of the photodiodes in each pair is precisely adjusted for the top surface of the currency paper. The focus of the other photodiode in each pair is slightly out of focus at the top surface. A phase diversity algorithm integrates the successive images from both photodiodes to form a clear image. A processor determines the presence or absence of the security feature and correspondingly provides visual or audible indication thereof. The processor contains stored information identifying currency denomination and a comparison is made at the time of verification to also determine the denomination of the proffered currency.

Abstract: In an optical character reading apparatus for optically reading a character image to produce a character signal representative of the character image, a collation and judgement circuit (22) compares a modified image with each of predetermined reference images memorized in a dictionary (21). A character detecting arrangement (11, 12) detects the character image to produce a detected image. A deleting arrangement (15, 16) partially deletes the detected image to produce a partially deleted image. A modifying arrangement (17, 18) modifies the partially deleted image into the modified image by the use of a reference signal produced in a reference signal producing arrangement (13, 14). It is preferable that the reference signal producing arrangement produces the reference signal in accordance with the detected image.

Abstract: A photocoupler for image recognition is disclosed which comprises a case, a pair of a light emitting diode and a light sensitive transistor, and a cylindrical lens which forms the light emitted from the diode into a linear light image on a surface of an object having printed pattern. After reflected on a surface of the object, the linear light image passes through the cylindrical lens and is received by the light sensitive transistor.

Abstract: A method and apparatus for identifying an object having non-specific outer boundaries, such as a leukocyte, includes a device for tracking, in two dimensions, the position of the object to be identified. An identification device for identifying the object tracked by the device includes a coherent light beam emissions source, a lens assembly to direct the coherent light beam from the source to the object to be identified, a detection device for detecting the light beam which is transmitted through the object, the detection device provided with a plurality of circular or semicircular coaxial sections, the center of which is at the axis of the coherent light beam in the plane on which Fraunhofer's diffraction patterns are formed. Finally, an identification apparatus is provided which uses the output of the detection device to provide various characteristic parameters which are utilized to identify the object.

Abstract: A method of initializing an optical scanning system by centering a benchmark code in an electrically adjustable benchmark window, the benchmark code being scanned by the optical scanning system while being transported through a paper handling machine. The improvement comprises the steps of providing an encoder for timing the machine cycles of the paper handling machine as a plurality of documents are processed therethrough; conveying a document containing a benchmark code to be scanned past a scanning device of the optical scanning system; enabling a counter at the lead edge of the electrically adjustable benchmark window; incrementing the counter once for every two encoder pulses; disabling the counter when the scanning device detects the benchmark code; displaying the count of the counter in a LED display; and adjusting the location of the benchmark window so that the benchmark code is substantially centered in the benchmark window based on the count displayed on the LED display.

Abstract: A photodiode and a phototransistor are positioned on opposite sides of a document subjected to verification for authenticity under transmitted light. A logic circuit determines the presence or absence of the security feature and correspondingly provides visual or audible indication thereof. The photodiode, phototransistor and related circuitry are arranged within an enclosure that is attached to a currency receiving device such as a cash register. The visual or audible indicators are mounted on the cash register for immediate indication of the currency verification to the cashier. A simplified capacitive proximity sensor can be employed, per se, for inexpensive applications or for redundant verification in combination with an optical detector. The shape of the capacitive sensor is configured to that of the security thread to discriminate between the security thread and the currency paper. Additional optical circuits are employed to detect counterfeit markings on the currency surface.

Abstract: An apparatus for the optical recognition of documents (1) extends over the entire width of a transfer plane (3). Regularly disposed photoelectric elements (4), whose optical axes create a single sensor plane (5) that is perpendicular to transfer plane (3), receive light (7) as altered by document (1). Photoelectric elements (4) are regularly disposed in a manner in which their optical axes are contained in a sensor plane (5) perpendicular to transfer plane (3). A region (8) of document (1), determined by sensor plane (5), is illuminated by at least one light line (9 or 10) which is inclined with respect to sensor plane (5). The light modified by document (1) is received by photoelectric elements (4). The adjacent light sources in each light line (9,10) are separated by a uniform source distance (A), which is smaller than the sensor distance (B) between two adjacent photoelectric elements (4). The light sources emit light within a narrow spectral width in pulses of short duration.

Abstract: A linear array of photodiodes and phototransistors is positioned on opposite sides of currency paper subjected to verification for authenticity under transmitted and reflected light. A logic circuit determines the presence or absence of the security feature and correspondingly provides visual or audible indication thereof. The photodiodes, phototransistors and related circuitry are arranged within an enclosure that is located next to a currency-receiving device such as a cash register. Visual or audible indicators are mounted on the device for immediate indication of the currency verification to the cashier. The arrangement of the photodiodes and phototransistors transverse to the major length of the currency paper detects the security feature while confirming that the security feature is within the currency paper and not on either surface.

Abstract: A layer of liquid, such as alcohol, water or a mixture thereof, on the finger touching surface of a platen provides an image in an optical fingerprint imaging system which assures valley and ridge definition and continuity by virtue of the liquid filling in the cracks and holes in the ridge zone, by creating an air pocket in the valley zone that holds the valleys open and by otherwise interacting with the finger to reinforce the distinction between valley and ridge zones in the optically imaged picture. Multiple interrogating light beams, each incident at greater than the critical angle on the finger touching surface of the platen assure imaging all minutia and that the valley zones in the image will be black. The technique is useful for roll prints and touch prints.

Abstract: Method for detecting marks (3) present on a paper web (1), which consists of successively producing and preferably recording light-intensity data in the form of intensity indications, using two alternate set-point values of light intensity representative of the presence of a mark or a non-mark. The method uses a process, deciding whether a certain light-intensity indication (V(new)j), shall be attributed to a mark, by selecting as a set-point value (V(old)j), one of the two alternate set points, either the nearest preceding indication (V(old)j) which has been adjudged as indicative of a non-mark and which essentially indicates light background of the paper web (1), or a preceding indication (V(old)j) which has been adjudged as indicative of a non-mark and which has been subjected to an intensity reduction of pre-determined magnitude (UP). There is also an apparatus for carrying out the method.

Abstract: An automatic verification device for currency and other security paper containing an embedded security thread first determines the presence of the thread within the paper and then assures that the thread is not present on the paper surface. The device is in the form of a stand-alone currency insertion unit similar to a credit card reader and includes a metal detection circuit to verify the presence of the embedded metal thread. Photo detectors within the unit detect the presence of reflected light off either or both currency surfaces. The currency is verified when the metal is detected and there is no reflection off either surface of the currency paper.

Abstract: A document reader (scanner) is disclosed which can automatically provide a provisional decision on the acceptability of the document image quality, and display the documents judged to be unacceptable for visual confirmation, using a display means. The apparatus can detect skewing of documents and anomalous document image contrasts, and the degree of skewing to be detected can be adjusted as required.

Abstract: A fingerprint image input apparatus for optically detecting ridges of a skin surface of a finger and inputting a detected signal to various control units, includes a transparent member having a lower surface and an upper surface on which the finger subjected to fingerprint detection is pressed, a light source for emitting light from said lower surface to said upper surface of said transparent member, a photosensor for detecting light reflected or scattered from said upper surface of said transparent member, and means, inserted midway along an optical path from said light source to said photosensor, for linearly (in a predetermined direction) focusing light incident on said photosensor, wherein the fingerprint input apparatus further includes another transparent member formed so that the upper surface of the transparent member on which the finger is pressed serves as a light scattering plane with respect to a wavelength of the light.

Abstract: A sensor assembly is provided in which a balanced pair of sensors is provided by abutting two optical devices each having a light emitting diode of infrared emitting diode type (IRED) and a photosensitive transistor. By using only one IRED which is located between the photo-sensitive transistors, a substantially identical image of an object placed above the IRED is provided to simultaneously to each of the phototransistors. The sensors mounted on a printed circuit board are also aligned to windows on a surface of the sensor assembly automatically by providing projections, preferably cylindrical, on the inside walls of the sensory assembly and complementary recesses on the printed circuit board. Signals are transmitted to a multiplicity of printed circuit boards simultaneously by threading conductors through holes situated at predefined locations on each printed circuit board.

Abstract: An apparatus for detecting and identifying a biological object. A transparent plate has a first surface onto which a light beam is projected and a second surface onto which a biological object to be detected and identified is placed. The light beam projected toward the first plate surface is transmitted through the plate and toward the object on the second surface, from which the light beam is reflected and retransmitted through the plate toward and through the first surface thereof and received and detected by an optical detector. The detection of a biological object is confirmed by comparing the change of the wavelength characteristics of the reflected and detected light beam in a predetermined time sequence according to the object being first placed upon and then pressed upon the second surface of the transparent plate with respective, known such characteristics thereof.

Abstract: A sheet-like pad having a grid pattern constituted by X-axis grid lines and Y-axis grid lines perpendicular to the X-axis grid lines, and adapted to be placed between a document and an optical reader of a type which comprises an optical scanner for scanning the document to read an image on the document while the document is radiated with first rays of light emitted therefrom and a position sensor for reading the grid pattern for locating the position of the optical reader on the document while the document is radiated with second rays of light emitted therefrom. The sheet-like pad comprises a film-like base having upper and lower surfaces opposite to each other, reflective layers formed on the upper surface of the base for periodically reflecting the second rays of light in first and second directions perpendicular to each other, and a protective layer formed on the upper surface of the base so as to overlay the reflective layers.

Abstract: A mark sense detector with a threshold detector having a weighted and variable threshold discriminates reflective variations on an illuminated surface such as a hand-marked lottery entry card having a plurality of tracks with potential reflective variations occurring at discrete positions thereon. The card is fed relative to an array of photodetectors for the tracks, each photodetector producing an input signal for a respective one of the tracks in response to reflections of the illuminated surface, the input signal varying with marks and with parameters of the illumination and feeding. The track input signals are applied to follower amplifiers for each of the tracks. An integrator for each of the tracks averages the output of the follower amplifier, the average being divided and applied as the threshold input to a comparator for each of the tracks.

Abstract: Lines of text (e.g., printing on a product) are verified by forming a one-dimensional image of each line substantially parallel to its length. This one-dimensional image information is compared to corresponding information for the intended lines of text. This comparison is preferably done using acousto-optic correlator systems. Space and frequency multiplexing may be used to allow parallel processing of several lines of text and/or to allow comparisons with multiple references to be made simultaneously. The invention may be used to determine the acceptability of products based on the correctness of the text image, and to reject products on which the correct text does not appear.

Abstract: For automatic recognition of the authenticity of items in sheet form such as bank notes, for example in an automatic service machine, the transparency of each bank note is examined in predetermined spectral ranges. The measuring system is arranged between units of a transport system and, in a passage opening formed from a collector and a diffuser, produces a narrow read-out light beam which extends transversely over a scanning plane. The bank note is conveyed through the read-out light beam, and the light which shines through the bank note in the read-out area is collected in the collector and passed to a photosensitive detector. An evaluation device forms a single measurement value in respect of transparency in the spectral range for each of the successively scanned read-out areas, and compares the measurement values of the bank note being tested with pattern signals stored in a memory of the evaluation device.

Abstract: An apparatus for discriminating the authenticity of a bill put into an automatic vending machine, etc. on the basis of a degree of brilliance of a surface of the bill, comprises two photodiodes for receiving light irradiated from a light-emitting diode and reflected by the bill, and a polaroid filter disposed in front of one of the photodiodes.

Abstract: In a medium detecting system having a plurality of optical sensors, each including a light-emitting element and a light-receiving element whose current varies with the amount of light received, and a load resistance unit provided in common for the sensors, the resistance of the load resistance circuit can be varied in accordance with load resistance selecting data supplied thereto. A sensor selector is responsive to sensor selecting data for selecting one of the sensors and connecting the light-receiving element of the selected sensor to the load resistance unit. A rewritable memory stores the sensor selecting data and data used for selecting the load resistance.

Abstract: A photodiode and phototransistor are positioned on one side of a document subjected to verification for authenticity under both transmitted and reflected light. A corresponding photodiode and phototransistor on the opposite side of the document are arranged for receiving the light transmitted through the currency if the security feature is not present. A logic circuit determines the presence or absence of the security feature and correspondingly provides visual or audible indication thereof. The photodiodes, phototransistors and circuit are arranged within an enclosure that is attached to a currency receiving device such as a cash register. The visual or audible indicators are mounted on the cash register for immediate indication of the currency verification to the cashier.

Abstract: An article of paper currency to be validated is scanned magnetically along the front to obtain a set of magnetic sample values and optically along the back to obtain a set of optical sample data values. Position-shifted versions of the magnetic data values are compared with stored sets of magnetic reference values for various denominations to obtain error figures for each denomination and degree of position shifting tested. A first indication of the denomination of the currency is generated on the basis of the least of the error figures so obtained. Position-shifted and amplitude-shifted versions of the optical data values are similarly compared with stored sets of optical reference values for various denominations to obtain error figures for each denomination and combination of position and amplitude shifting tested. A second indication of the denomination of the currency is generated on the basis of the least of the error figures obtained by this latter method and compared with the first indication.

Abstract: Apparatus for reading a mold-identifying code in the form of a plurality of surface irregularities extending in an arcuate array around the container heal concentrically with the container axis. A starwheel conveyor sequentially moves a series of containers in an arcuate path about a conveyor axis to and through a reading station. A belt positioned adjacent to the conveyor periphery engages containers at the reading station and is driven so as to rotate the containers about their central axes. A light source is imaged at the conveyor axis through container heel. A scanning mirror is positioned to receive an image of the light source transmitted through the container heel and to reflect such image onto a camera. The scanning mirror is driven as a function of conveyor rotation so as to follow a container traveling through the reading station and reflect onto the camera an image of that circumferential portion of the illuminated container heel closest to the conveyor axis.

Abstract: A recognition device for authenticating documents is disclosed. The recognition device comprises a reading head for optically scanning the documents. The reading head includes at least two modules of substantially identical construction, each of which is provided with a line of photosensors. The reading head also includes means for determining the spectral sensitivity of the modules. The recognition device also includes a conveying system for providing relative movement between the reading head and the documents being scanned. An evaluation means correlates signals provided by the photosensors with prestored values to control a sorter which sorts the documents based on their authenticity or falsehood.

Abstract: Documents such as checks, food stamps or the like are successively advanced along a path between a transversely spaced pair of light-emitting diodes (LEDs) and a correspondingly spaced pair of photodiodes to generate signals for counting and misfeed detection. Various error detectors detect sheet misfeed by integrating signals derived from one or more sheet sensors and comparing the integrated signal with reference signals that vary with the drive speed. A doubles detector generates a signal indicating a double feed if the integral of an analog optical density while below a predetermined threshold lies beyond a predetermined limit. A potentiometer permits adjustment of the threshold optical density at which the integrator becomes operative. An LED coupled to the output of a spare amplifier on the chain note board permits detection of the momentary presence of an output signal from a particular error detector.

Abstract: Apparatus (2) for characterizing or identifying an article (10) having a magnetic material thereon which stores information relating to the article, the apparatus comprising means (24) for irradiating the article with electromagnetic radiation of a particular spectral characteristic, means (26,28,30) for detecting electromagnetic radiation which is emitted by or reflected from the article due to the irradiation thereof by the means for irradiating, means for determining whether or not the detected radiation has prescribed spectral characteristics thereby to detect whether or not the article is genuine, and a magnetic detector means for reading information which is stored on the magnetic material, the means for detecting being arranged to control the magnetic detector means in response to the detection or whether or not the article is genuine. The invention also provides a method for characterizing or identifying an article having a magnetic material thereon which stores information relating to the article.

Abstract: A paper money discriminator for identifying the type of a bank note by detecting colors thereof from reflected or transmitted light obtained by irradiating the bank note. The paper money discriminator is provided with optical fiber bundles disposed so as to respectively face a light source and color detecting sensors, and color filters disposed in positions adjacent to the color detecting sensors. The top ends of the optical fiber bundles face an inspection point on the bank note. The paper money discriminator is provided with identifying systems each of which is composed of a detecting unit, a calculating unit and a money type identifying unit and is adapted for detecting reflected or transmitted light in the form of two separated color components issuing from a type of bank note, obtaining the ratio of these components, and comparing a signal representing a calculated pattern with the reference pattern signals, thereby identifying the money type.

Abstract: A label inspection apparatus for inspecting labels on containers moving by a conveyor past the inspection apparatus senses the reflectivity values of pixels located over substantially the entire label for each container in a sample having a predetermined number of containers. The pixel locations are the same for each label in the sample and each label to be inspected, and the containers and labels in the sample are typical of those to be inspected. From the reflectivity values MEANS and standard deviation values are established for the containers in the sample. Limits by which containers to be inspected are to be judged as pass or fail are established as a function of the MEANS and standard deviations values. The reflectivity value in each pixel in each label to be inspected is sensed as with the containers in the sample, and a function of these values is compared with the estabilished limits, and from the comparison a label is passed or failed.

Abstract: A mold number reader for detecting code marks at the heel of a transparent bottle or the like, such code marks desirable being in the form of dots or balls protruding from the bottle's heel. During rotation of the bottle, its heel portion is illuminated with a structured light source in the form of a narrow rectangle, which light is selectively reflected by code marks and collected by field-type optics. The use of a well defined light source of small area provides a high input signal level, while the field optics enjoys a high depth of field and hence decreased sensitivity to bottle placement during inspection. The light source may be a modulated laser diode and the signal processing electronics may include a demodulator to process the photodetector output signal. The use of heterodyned signal processing decreases the sensitivity to ambient light and other sources of noise in the output signal.

Abstract: This invention relates to a grating adjustment apparatus of 3-beam type optical pick-up for the compact disk player and, more particularly, to an apparatus automatically and readily adjusting a grating to the angle where the target value of a tracking error signal is obtainable. Sub-beam currents from the optical pick-up is, through current-voltage transducing amplifiers, converted into voltage signals, which are applied to a differential amplifier. The differential amplifier puts out the tracking error signal mixed with noise, which passes through a band pass filter removing said noise. So only pure tracking error signal is obtained, which is, after its phase is compensated by the low frequency lag compensator, applied to a differentiator. This signal is applied to a discriminator.

Abstract: A method of measuring non-linearity of a pattern edge of a pattern formed on a metal plate such as a glass plate and an apparatus for measuring the same are disclosed. With this novel pattern edge measurement system, first is to dispose a pattern to be measured so that a photosensitive picture element column in a light-receiving unit is substantially in parallel with a pattern edge of an image of the pattern to effect a relative movement of the light-receiving unit or the image of the pattern so that light-receiving unit traverses the pattern edge. Next is to memorize a signal indicative of a light received by the photosensitive picture element column every predetermined moving distances of the light-receiving unit or the pattern to determine a pattern edge position per each photosensitive picture element by making use of the received light signal. Then, a non-linearity of the pattern is computed on the basis of each pattern edge position.

Abstract: A bank note discriminating apparatus has a detector for detecting light reflected by or transmitted through a bank note upon irradiation of light while the bank note is being conveyed, and a judging circuit for integrating a reflected light signal from the detector to obtain an amount of light reflected by the bank note and for comparing the amount with a reference signal so as to discriminate a fit note from an unfit note.

Abstract: A mold number reader for detecting code marks at the heel of a transparent bottle or the like, such code marks desirable being in the form of dots or balls protruding from the bottle's heel. During rotation of the bottle, its heel portion is illuminated with a structured light source in the form of a narrow rectangle, which light is selectively reflected by code marks and collected by field-type optics. The use of a wall defined light source of small area provides a high input signal level, while the field optics enjoys a high depth of field an hence decreased sensitivity to bottle placement during inspection. The light source may be a modulated laser diode and the signal processing electronics may include a demodulator to process the photodetector output signal. The use of heterodyned signal processing decreases the sensitivity to ambient light and other sources of noise in the output signal.

Abstract: This application discloses a method and apparatus for ascertaining the fitness of a document having some printed regions and some unprinted regions, by determining its degree of soiling. A sensor (16) provides reflectance signals representing the intensity of light reflected from a number of sensed elements on the face of the document. A signal processing circuit responsive to the reflectance signals includes means (26) for determining for each of a number of areas of the document, the number of elements in the area which result in a signal level exceeding a first threshold which represents the upper limit of brightness for printed areas on the document; and means (24,34,36) for determining whether the number of elements exceeding the first threshold reaches a given proportion of the total number of sensed elements for that area.

Abstract: In a method of reading a concavo-convex bar code disposed on the surface of an article, the improvement comprising the steps of scanning the concavo-convex bar code by a displacement sensor to detect the concavo-convexity, determining the areas of the resulting concavo-convex waveforms, and comparing the area thus obtained with the reference areas of the thick and thin bars of the bar code to judge the pattern of the bar code.

Abstract: A scanner for scanning an increased area of a finger held or pressed on a concave elliptically cylindrical surface having two focal axes includes a linear light source positioned at one focal axis of a first reflective cylindrical elliptical surface, the other focal axis coinciding with one focal axis of the concave elliptical surface in contact with the finger. A second reflective, cylindrical elliptical surface has two focal axes where one of the axes coincides with the position of a linear array combination of photosensitive elements and charged coupled devices and the other coincides with the other focal axis of the concave elliptical surface in contact with the finger.

Abstract: A method and an apparatus for inspecting a high density pattern in which a signal obtained by scanning a mask substrate having a high density pattern including repeated pattern portions is collated and compared with the signal obtained from original data used to generate the pattern. Repeated pattern data corresponding to the signal obtained by scanning said mask substrate and the repeated basic pattern data corresponding to the basic pattern of the repeated pattern portion are repeatedly collated and compared when inspecting repeated pattern portions and the repeated pattern data and the original pattern data obtained by sequentially converting the original data in synchronization with the scanning are collated and compared when inspecting the high density pattern of an area other than the repeated pattern portions.

Abstract: A detection system for utilization with a paper security or currency validation apparatus wherein a correlation is made between reference patterns and cross hatch lines located in the portrait background on the paper and the presence of one of two paper currencies is determined. Fundamentally the invention consists of a single reticle which contains a lens whereon are located the cross hatch references for two different paper currency denominations. Within the reticle assembly are located two photosensitive cells, one for each reference pattern. Each photosensitive cell is connected to its own authenticating circuitry which validates the presence of a specific paper currency note. Should the tested paper pass the authenticity test of one authenticity circuitry, the other is disabled. Should the tested paper fail both authenticating tests, it is rejected.

Abstract: A color-sensitive currency verifier operating with a plurality of narrowband light sources optically coupled to a single broadband photodetector and including means for automatically balancing the color outputs of the various light sources. Color balancing is accomplished just prior to the examination of a specimen bill. The data samples are taken under the control of a microprocessor and used to authenticate the specimen bill both on the basis of pattern and color information stored in memory. Multiple data samples from a single target area are divided to compensate for soiling condition of the bill, and further compensation for condition of the bill is provided by adjusting the conversion scale factor of an A/D converter on the basis of data samples taken from a reference target area on the surface of the specimen bill before test or data samples are taken.

Abstract: A method is provided for observing, preferably through the medium of an optoelectronic pick-up, the carrier to be checked which is illuminated by a light beam having an angle of incidence of at least 45.degree. through a rotary disc comprising alternately transparent and opaque sectors spaced from one another by a distance at least substantially equal to the distance measured between the lines of the copperplated printing formed on the carrier. The carrier image is formed in the plane of a detector by means of an optical system. If the carrier has a copperplate printing formed thereon, a moire effect is observed. If the pick-up extends over several transparent sectors of the disc this moire effect is converted electrically into a very pronounced periodic variation of the current delivered by the pick-up, at the sector passage frequency.

Abstract: Apparatus is disclosed for scanning a banknote (33). A lengthwise strip of the banknote (33) is illuminated with white light, and the banknote is moved parallel to its width. Light reflected from all regions of the lengthwise strip is conveyed through an optical fibre fishtail array to a single photodetector, or to a spectroscope and then to several photodetectors for color scanning. The waveform produced by the or each photodetector is then characteristic of the surface of the banknote, and is used in an analyzing circuit for banknote pattern recognition, or to sense the condition of the banknote with regard to its age or degree of soiling. The analyzing circuit includes means for compressing or expanding the length of the waveform to give it a standard length for subsequent comparison with one or more stored characteristic waveforms in a memory (16).

Abstract: An improved universal document validator in which a document is transported along a path past light detectors and associated light sources positioned above and below the path, such that light from the sources is directed toward the path and reflected onto the detectors to produce outputs therefrom. A first stored value representing the desired output of each detector with no document in the transport path and with its associated light source illuminated is divided by the actual output of each detector with no document in the transport path and with its associated light source illuminated, to produce a plurality of quotients. If any of the quotients falls outside a predetermined range, the validator turns itself off. A microprocessor control system uses the outputs of the detectors with a document in the transport path together with the quotients to produce an indication of the validity of the document.

Abstract: A microprocessor controlled currency note validator includes a transport for propelling an inserted note longitudinally past an optical scanning station. Infrared and visible color reflectance readings and opacity readings are taken along several longitudinally extending tracks on the note. The microprocessor normalizes the reflectance readings to accommodate for variations in soiling and compares the normalized reflectance readings and the opacity readings against stored acceptance band data, correcting for pattern registration variations if necessary. The length of the note is also checked and a validation signal is provided if the note passes the optical tests and the length test. During the idle cycle, the microprocessor automatically adjusts the optical circuitry to compensate for component drift and dirt buildup. The microprocessor also provides a visual display of any detected malfunctions.

Abstract: Described is a method of discriminating between front and back sides of the paper sheet bearing different printed design on the front and back sides, the printed design being in dissymmetry both in the up and down direction and in the left and right direction. The amount of light transmitted through plural portions of the paper sheet is sensed for deriving pattern signals indicative of changes in the amount of transmitted light, said pattern signals being then compared to reference pattern signals stored in advance to permit discrimination between the upper and lower edges and between the front and back sides of the sheet.

Abstract: In a printed matter identifying apparatus of the present invention, the light source illuminates the detecting fields of the note. The reflected light-waves from the detecting fields are lead to the light receivers through the focusing lenses, the diffusion plates, the optical slits, the light conducting paths and red color transmitting and blue color transmitting filters. The output signals from the light receivers are amplified by the amplifiers and sampled by the sampling circuits. Among the sampled color component signals, the red component signals are applied to the subtracter to produce the red component difference signal and the blue component signals are applied to the adder to produce the blue component sum signal. These different signal and sum signal are applied to the comparators respectively and compared with the reference signals read out from the memory. The output signals from the comparators are supplied to the judgment circuit where the judgment of the printed matter is performed.