Classifications

• • G—PHYSICS
  • G06—COMPUTING OR CALCULATING; COUNTING
  • G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
  • G06K7/00—Methods or arrangements for sensing record carriers, e.g. for reading patterns
  • G06K7/10—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation
  • G06K7/14—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation using light without selection of wavelength, e.g. sensing reflected white light
• • G—PHYSICS
  • G06—COMPUTING OR CALCULATING; COUNTING
  • G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
  • G06K19/00—Record carriers for use with machines and with at least a part designed to carry digital markings
  • G06K19/06—Record carriers for use with machines and with at least a part designed to carry digital markings characterised by the kind of the digital marking, e.g. shape, nature, code
  • G06K19/06009—Record carriers for use with machines and with at least a part designed to carry digital markings characterised by the kind of the digital marking, e.g. shape, nature, code with optically detectable marking
  • G06K19/06018—Record carriers for use with machines and with at least a part designed to carry digital markings characterised by the kind of the digital marking, e.g. shape, nature, code with optically detectable marking one-dimensional coding

Definitions

• the invention is in the field of code detection and relates to a device comprising a transmitter, receiver and code carrier, the transmission medium preferably being light and thus the transmitter being a light source and the receiver being a light-sensitive element.
• the scanning of code carriers that can be magnetic tracks for magnetic scanning, color arrangements for light scanning, charging patterns for electrical scanning, etc., are essentially based on the principle of serial scanning. This requires the movement of the scanning means (for example a scanning) or the movement of the code carrier, in short, the relative movement between the code arrangement and the means detecting this code arrangement. As a rule, the code carrier is moved past the reading device (special case light pen), since scanning devices are very expensive.
• a code means is used which has the ability to impress information on the transmission medium used, which is additionally used by a special device in the detection.
• Fig. 1 shows a basic arrangement of
• Transmitter / receiver and code carrier 2A, 2B, 2C, 2D show different operating states of the system;
• FIG. 1 shows the truth table of the operating states shown in FIG. 2;
• Fig show a coding carrier with the digital states
• Fig. Shows a schematic representation of a possible deviation from the given reading axis as a snapshot, for example as part of a jitter in the Co emé Adjust;
• Fig shows a perspective view of a first embodiment (fork barrier)
• F g shows a perspective view of a second embodiment (single-page reader using reflection)
• the schematic principle representation in FIG. 1 shows the basic arrangement of a code reading system consisting of transmitter / receiver and code carrier.
• the transmitter consists of a light source L, which can be an incandescent lamp in the visible range or in the UV or IR limit range, a laser source in a usable range or another radiation source.
• the radiation source is preferably used in pulsed operation and only information transmitted by the radiation is evaluated with the pulse frequency of the light source.
• the receiver contains two detectors D1 and D2, which receive light from the radiation source L via a beam splitting mechanism (beam splitter).
• the beam splitting mechanism here is a semi-translucent mirror M in a ratio of approximately 50/50.
• Each detector Dl, 02 has a polaroid filter P1 and P2 connected upstream, which are optically crossed to each other.
• the coding carrier C has coding elements P, which also have polaroid filters pO and pl as transmissive windows, the filters being optically crossed to one another depending on the code element 0 or 1.
• the two stationary filters with P1 and P2 are assigned to the detectors and the non-stationary filters P on the code carrier C with the bit information pO and pl. Due to the stationary filters, however, each detector is either a 0 detector or a 1 detector, it being emphasized that both detectors operate simultaneously, and 0 (zero) is not manifested, for example, by the lack of light.
• the light coming from the radiation source has vibrations in all levels of the direction of propagation, which is indicated by a circle with spokes next to it
• the detector D2 receives bit-1-shaped light and the O detector D1 receives no light. Detector D2 thus indicates the presence of a 1-bit in the beam.
• FIG. 3 shows the truth table.
• A there is no code carrier in the beam path, both detectors receive light and together report status 1.1 according to the truth table. This is an equivalence and means "no code carrier available”.
• Cases B and C show the adequately polarized bit-0 and bit-1 and the detectors Dl and D2 report the states 1.0 and 0.1 according to the truth table. These are antivalences (together XOR) and mean a ZERO or a ONE of the code on the code carrier.
• D there is an opaque object in the beam path, for example the code carrier frame and the detectors report "no light", which corresponds to the state 0.0 according to the truth table.
• the synchronization track is already given by the code fixed, since the system can detect and also detect every (nota be ⁇ e equally wide) window 0 or 1.
• the XOR function can be evaluated. The inclusion of equivalences, i.e. the full utilization of the truth table, enables the
• Figure 4 shows the code carrier C with a 6-byte, consisting of windows with polarization filters, pO and pl, which are crossed to a bit sequence 0.1, 0.0, 1.0.
• the detectors D1, D2 report to the left of the code carrier with 1.1 "no code carrier yet", then they report with 0.0 "frame arrived” and immediately afterwards they recognize the first 0-bit (1.0), is detected by the detector Dl. Then there is again an opaque web (0.0) followed by a 1-bit (0.1), which is now recognized by detector D2.
• the detectors found 2 windows, which corresponds to 2 elements of the synchronization nested in the information.
• the code carrier is read until the arrival of a 1.1 the detectors "end of Code carrier "and the evaluation system can also initiate the following process step with this information.
• the states of the truth table can also be evaluated, in the sense of security of idea, in such a way that only permitted states (antivalences) are evaluated on a channel and unauthorized states (equivalences)
• the whole truth table can be evaluated simultaneously on a second channel.
• Figure 5 shows a schematic representation of the relative insensitivity of the mechanical (passing) of the code carrier C past the transmitter / receiver.
• a skew 1 around a pivot point 0 through the angle alpha to the ideal reading axis LS is shown.
• One of the badly affected marginal windows P is shown; a window in the area of the pivot point 0 would only be insignificantly affected. This deflection or deviation from the desired reading direction would have a disruptive effect on a synchronization track carried along, but since in the solution according to the invention the bit window effects the synchronization at the same time, all that needs to be done is to ensure that all windows of an x byte are still read even in skew can be.
• the skewing also has optical limits, namely the polarization critical angle, which is a function of the detector intensity. It has been shown experimentally that a skew jitter within + -20 can be tolerated without further effort, with corresponding effort, which is however not the aim of the invention, jitter of + -40 can still be optically detected (the limit is theoretically included) 45, half the crossing angle), but there are hardly any such deviations anyway. With this explanation, however, it is shown that this principle of identification is not only safe in normal operation, but also equally safe in the event of severely disrupted operation. However, this latter operation need not be a disturbed operation.
• the invention aims to allow a reading operation with a remarkable degree of mechanical freedom, which makes the proposed system viable for the widest applications, for example for the rough operation of transport systems.
• existing transport systems can be retrofitted with any kind of rope, but also better ones, with the identification system according to the invention.
• FIGS. 6 and 7 show two embodiments of the invention, one of which works with a light barrier by means of transmission and the other with a transmitter / receiver arranged on the same side by means of reflection.
• the arrangement according to FIG. 6 corresponds in structure to the arrangement discussed in connection with the principle solution, namely that with a transmission of the code carrier C.
• the figure shows in spatial representation the transmitter S with the light source L arranged in a lower housing part 60, which lower part with an upper housing part 61 can be closed.
• a light exit opening 65 Through a light exit opening 65, if the distance to the code carrier and receiver E is not too great, without special optical aids, the light beam reaches the outside and falls directly on the receiver E if there is no coding carrier in the barrier (equivalence) or is darkened, if there is any object which is not transparent, is located (equivalence) or falls through a code window (antivalence) onto the receiver E, which detects the incoming light as described.
• This receiver E is also shown here in a housing lower part 62.
• the beam splitting mirror M and the two analyzer filters P1 and P2 are arranged behind a light entry opening 66, for example in slots (not shown) in the
• the associated detectors D1 and D2 are arranged behind the two filters P1 and P2 and are likewise inserted into prepared recesses (not shown) in the housing base.
• the lower housing part of the receiver 62 is covered with the upper housing part 63.
• the individual housing parts 60, 61, 62, 63 are preferably designed, for example as injection molded parts, so that they can be used both for transmitters and receivers and as upper and lower parts in order to further utilize the structural simplicity of the entire detection device.
• FIG. 7 Another embodiment is shown in FIG. 7, which detection device, transmitter S and receiver E are accommodated in the same housing.
• the light passes through an exit opening 71, for example with a focusing lens (not shown here) through a code window P (pO, pl), is reflected by the reflecting rear wall R and passes through because it has the correct vibration level the same code window back again, through a light entry opening 72 onto the beam splitting mirror M via the analyzers P1, P2 onto the detectors D1, D2.
• the reflector R should be such that the light arriving from the polarization filter pO, pl is not scattered and / or refracted.
• the housing parts can also be designed using injection molding technology in such a way that the lower and upper parts are interchangeable.

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• Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Theoretical Computer Science (AREA)
• General Physics & Mathematics (AREA)
• General Health & Medical Sciences (AREA)
• Toxicology (AREA)
• Artificial Intelligence (AREA)
• Computer Vision & Pattern Recognition (AREA)
• Electromagnetism (AREA)
• Health & Medical Sciences (AREA)
• Optical Communication System (AREA)
• Mechanical Optical Scanning Systems (AREA)
• Investigating Or Analysing Materials By Optical Means (AREA)

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Publications (1)

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Citations (3)

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• 1986
  • 1986-11-18 CH CH4600/86A patent/CH671838A5/de not_active IP Right Cessation
• 1987
  • 1987-11-05 EP EP87907423A patent/EP0333724B1/de not_active Expired - Lifetime
  • 1987-11-05 JP JP62506769A patent/JPH02500696A/ja active Pending
  • 1987-11-05 FI FI892169A patent/FI892169A0/fi not_active IP Right Cessation
  • 1987-11-05 WO PCT/EP1987/000677 patent/WO1988004083A1/de not_active Ceased
  • 1987-11-05 US US07/228,932 patent/US4906829A/en not_active Expired - Fee Related
  • 1987-11-17 ES ES8703274A patent/ES2008331A6/es not_active Expired

Patent Citations (3)

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