WO2010012046A1

WO2010012046A1 - A code carrier and an apparatus for reading a code carrier

Info

Publication number: WO2010012046A1
Application number: PCT/AU2009/000984
Authority: WO
Inventors: Devlin Wollstein; Andrei Zvyagin
Original assignee: Encryption Technologies Corporation Pty Ltd
Priority date: 2008-08-01
Filing date: 2009-07-31
Publication date: 2010-02-04

Abstract

An apparatus (16) for reading a code carrier (14), e.g. a code carrier, having a coded fluorescent marking that passes through a detection zone is disclosed. The apparatus (16) includes a transmitter arrangement (84) for transmitting an electromagnetic wave, e.g. at the absorption wavelength of the fluorescent substance, for causing the coded fluorescent marking to emit fluorescent emission waves having an emission wavelength. The apparatus (16) also includes a receiver arrangement (90) for receiving the emitted waves and converting the received waves into encoded output signals. In one form this can be used to form a visual image of the coded marking. The apparatus (16) also includes a decoder module (102) for decoding the encoded output signals into decoded record information. This can be used to authenticate the material from which the coded marking is formed, and it can also be used to decode an image of the coded marking.

Description

A CODE CARRIER AND AN APPARATUS FOR READING A CODE CARRIER

FIELD OF THE INVENTION

This invention relates to a code carrier and an apparatus for reading a code carrier having a coded marking. This invention also extends to a method of reading a code carrier, a method for producing a code carrier, an apparatus for producing a code carrier, and a coding system including the code carrier and the apparatus for reading the code carrier.

This invention relates particularly but not exclusively to a fluorescent code carrier and an apparatus for reading a fluorescent code carrier, particularly for use in applications in the logistics industry such as inventory management and baggage tracking. It will therefore be convenient to hereinafter describe this invention with reference to this example application. At the same time however it is to be clearly understood that the invention is capable of broader application. In particular the invention could be applied to other forms of code carriers that emit a signal in the form of electromagnetic radiation of different wavelength in response to incident electromagnetic radiation.

BACKGROUND TO THE INVENTION

There are many spheres of modern industry in which it is highly desirable if not essential to correctly identify articles. This can be necessary for tracking and authentication of articles. Articles can be identified by means of a record carrier that is mounted on the article, or marked on the article, and provides information that can be read on the identity of the article, or other information on the article (record information). In some instances the identity carrier carries a unique identification indicator so that the article is uniquely identifiable. One well known type of record carrier is a code carrier known as a barcode carrier which is integrated into a barcode system. A barcode system is a network of handheld scanners and printers that are operatively coupled to a number of computers. These systems are used to automate data collection and are widely used in resource management systems. A barcode system utilizes the identification of visual patterns to identify and classify articles. A barcode includes markings that are printed on a carrier surface of a carrier that identify the article and/or provide information on the article. The properties of the markings convey coded information on the article. By the term properties of the markings is meant the shape of the markings and the size of the markings (individual mark properties) and also the manner in which individual marks are arranged relative to each other (group mark properties).

These individual and group marking properties together are used to encode information into the composite barcode marking. The barcode markings are readable, for example with an optical reader system that detects an image of the markings and then decodes the marking properties into useful information. This useful information identifies the article and also provides information on the article. The optical reader system includes a laser that directs laser light onto the barcode image, and a detector which then builds up a detected barcode image of the actual barcode image on the barcode carrier.

It will readily be appreciated that by varying the number of barcode markings, the shape of each marking and the spatial arrangement of the barcode markings relative to each other, a large number of permutations of barcode images can be generated. This feature naturally enhances the utility of the barcode system and has fostered its uptake in commercial applications.

In one application a barcode system can be used to track the lending and return of library articles in a library. In such a case the barcode system uniquely identifies that particular library article.

In another application barcode systems are used in supermarkets to identify certain product lines and provide certain information on the article such as the price which be read by a barcode scanner at the checkout. Further these systems can provide further information to a central management system that can be used to manage inventory levels.

In another application a barcode system can also be used to authenticate an article so that it can be identified as a genuine article, e.g. luxury goods, as a means for identifying counterfeit goods which are otherwise visually indistinct from the genuine goods, by reading the barcode on the goods.

One inherent disadvantage of a barcode system is that the barcode image is a visual image in which the identifying characteristic is its visual form, e.g. size and shape of the barcode marks and general arrangement of the composite barcode marks viewed as a whole.

As the barcode image is one of physical and visual form it is possible for the visual form to be copied by copying the visual features of the mark. As it is a visual feature it is patent or manifest to any person studying the barcode image and cannot be kept secret. It will be readily recognized that this limitation can lead to a loss of integrity of an identification system. Further it could also lead to perceived authentication of goods because a barcode image applied to the article corresponds to that of the genuine article when the article is not in fact the genuine article.

Yet further Applicant is aware of actual instances where the codes or coding rules of barcode system that are used to encode information into printed code, such as barcode images, have been deciphered by unauthorized persons typically with fraudulent intent. Once the barcode has been deciphered the barcode information can be successfully copied and applied to articles to deceive barcode reader systems as to the identity of the articles. This shortcoming limits the application of the barcode system particularly in applications where the identification of authentic articles is of the utmost importance.

Another shortcoming of barcode systems is that the barcode image applied to the code carrier on the article needs to be in close proximity to the barcode reader for it to be read by the optical reader system. By placing the carrier in close proximity to the optical reader is meant that the optical reader is usually placed adjacent to the barcode to be read and typically not more than 10-15 cm away from the barcode. Applicant understands that the range of barcode readers is limited to reading barcode that is not more than 0.5 away from the reader in most applications. This shortcoming has also limited the application of the barcode system. This is particularly so in applications where it is not practical to place the code carrier carrying the barcode image in close proximity to the optical reader.

Another system for use in the identification of articles is a RFID (radio frequency identification system). This system uses code carriers that are RFID tags applied to an article for the purpose of identification and tracking the article using radio waves. An RFID tag generally contains the following two basic parts. The first is an integrated circuit for storing and processing information and modulating and demodulating a radio frequency signal. The second component is an antenna for receiving a radio signal from a reader and then transmitting a return radio signal back to the reader containing information about the RFID tag. The RFID tag carries a unique code in an onboard memory and this case is usually included in the information that is transmitted back to the reader.

In this application the tag is typically passive and by this is meant that the tag does not have an onboard battery supply. The RFID tag is energized by electromagnetic energy when it is interrogated by an RFID reader as it passes in proximity to the reader. The energised RFID tag then transmits its unique identification code back to the reader which can then report this identification back to a central information management point.

One advantage that RFID systems using RFID tags have over printed code carrier systems, such as barcode systems, in that they do not require direct line of sight with the reader to detect or read a tag.

A disadvantage of RFID systems is that the range of an RFID tag, particularly a passive RFID tag that does not have its own onboard power supply, is quite limited and this also limits the use of RFID systems in some applications. While some RFID tags can be read by a reader that is located several meters away and beyond the line of sight of a reader, RFID tags with this range capability tend to be considerably more expensive than printed code carrier systems, such as barcode systems.

As a general proposition RFID systems are considerably more expensive than barcode systems and this high cost has limited the range of applications in which RFID technology has been adopted to date. Another potential disadvantage of an RFID system is that it may not be able to read an RFID tag if the electromagnetic field is interfered with by a metallic object in proximity to the tag. RFID systems are known to become unreliable in environments where there are high levels of metallic interference. Such environments are often encountered in luggage tracking systems and in warehouse storage and pallet systems. One example application in which RFID systems have been used is on toll roads.

A reader is located in a toll booth that reads an RFID tag mounted on a vehicle passing through the toll booth. RFID systems have also been used on Metro systems and other mass transit systems where they are used to encode ticket information. In another example application RFID systems have also been used in libraries and book stores for tracking books.

Yet further Applicant is aware of RFID tags being used in passports for authentication and also for providing information on a passport holder and also for screening people passing through immigration control points. The RFID system has been shown to be resistant to copying in applications requiring high levels of security such as passports and credit cards.

Clearly therefore it would be advantageous if a code carrier system for article identification could be devised that yielded a code carrier that ameliorated at least some of the shortcomings of the barcode system described above.

In particular it would be advantageous if a system could be devised that was less vulnerable than barcode systems to having its encoding and decoding system deciphered and that was inherently more secure. It would also be advantageous if the system had code carriers that could be read over greater distances than visual image based barcode systems.

It would also be advantageous if a code carrier system could be devised that could be used in large scale applications at lower cost that existing RFID systems. Such a code carrier system would have the potential to significantly broaden the range of applications and the extent of use of code carriers.

SUMMARY OF THE INVENTION

According to one aspect of this invention there is provided a code carrier which includes: a carrier body having a carrier surface; and at least one coded marking on the carrier surface that emits a signal in the form of electromagnetic radiation in response to a stimulus.

The coded marking on the carrier surface may emit a luminescent signal as a result of luminescence. The luminescent signal may be in the form of electromagnetic waves and the waves may be able to be focused to form an image of the coded marking. The stimulus may be provided by an incident beam of electromagnetic radiation, e.g. that is absorbed by the coded marking to some extent and then thereafter emits a beam of electromagnetic radiation of a different wavelength to the incident radiation. Thus non radiative excitation of a substance and the molecules of a substance is largely excluded.

In one form of the invention the coded marking may be a fluorescent marking. The coded fluorescent marking may include a plurality of fluorescent marks that are spaced apart on the carrier surface. The coded fluorescent marking may include a plurality of unique marking characteristics for encoding information into the coded fluorescent marking.

The coded fluorescent marking may include a plurality of individual fluorescent marks, each individual fluorescent mark including at least one individual mark characteristic for encoding information into the coded fluorescent marking. At least one of the individual fluorescent mark characteristics that is used for encoding information into the coded fluorescent marking, may include a fluorescent mark characteristic of the fluorescence substance forming the individual fluorescent mark.

The fluorescent mark characteristic may include a trigger wavelength of the fluorescence substance forming the individual fluorescent mark and/or an emission wavelength of the fluorescence substance forming the individual fluorescent mark. Also, the fluorescent mark characteristic may include an absorption wavelength of the fluorescence substance forming the individual fluorescent mark.

The fluorescent mark characteristic may include a measure of the Stokes shift of the fluorescent substance forming the individual fluorescent mark. In addition, the individual fluorescent mark characteristic that is used for encoding information into the coded fluorescent marking may include an outline shape of the individual fluorescent mark.

The individual fluorescent mark characteristic that is used for encoding information into the coded fluorescent marking may include the size and dimension of the individual fluorescent mark.

The individual fluorescent mark characteristic that is used for encoding information into the coded fluorescent marking may also include a position of the individual fluorescent mark on the carrier surface relative to a predetermined reference point on the carrier surface. The coded fluorescent marking may include a group of fluorescent marks, with the group having at least one group mark characteristic for encoding information into the coded fluorescent marking. At least one group mark characteristic may include a pattern formed by the spatial arrangement of the members of the group of individual fluorescent marks relative to each other. The at least one group mark characteristic may include the number of marks in the group of individual fluorescent marks.

The individual fluorescent marks forming the marking may be formed from different types of fluorescent substances.

Instead the different fluorescent materials making up the marking may be formed of the same fluorescent material. This may be convenient when the apparatus for reading the code reads a coding property relating to the fluorescent material first, and then reads the visual mark characteristics, and then decodes these to yield the record information.

The individual fluorescent marks may be formed from a mixture of at least two types of fluorescent substances. The type of fluorescent substance from which the fluorescent marks are formed may include a transparent fluorescent substance that is substantially invisible to the naked human eye. An invisible physical mark is carried on the code carrier, which may be useful in some applications.

In other forms the type of fluorescent substance used in the coded marking may be selected so that it is visible to the naked human eye. In these other applications it is more convenient for the mark to be visible to humans. The fluorescent code carrier may include individual marking characteristics and/or group marking characteristics selected according to a set of code rules forming a code scheme for converting information into the individual mark characteristics and/or group marking characteristics. Thus, information may be encoded into the fluorescent marking by using combinations of the group mark characteristics and the individual mark characteristics. Thus, a fluorescent coded marking may be uniquely formed with an encoding scheme setting out code rules for converting information into a unique combination of marking characteristics that is incorporated in the fluorescent coded marking. At least one additional record carrier may be selected from the group comprising: an encoded non-fluorescent marking, a bar code, a magnetic strip-type record carrier, an embedded RFID-tag, and an embedded nano-particle transponder.

The carrier body may be formed from a sheet material defining the carrier surface, the coded fluorescent marking being printed on the carrier surface. The carrier body may include a tag for attachment to an article of clothing. The carrier body may include a self- adhering label for sticking to an article.

Thus, the coded fluorescent marking may form an encoded mask that overlays a record carrier. It will be appreciated that using coded fluorescent markings in combination with other record carriers increases the available coding combinations. The coded marking may be formed by a nano-particle based marking. The nano- particle based marking may include inorganic semiconductor nano-particles. Nano- particles are small particles that are sized between 1 and 100 nanometers. Nano particles have a very large surface area to volume ratio and have properties that are different from bulk material. The coded marking may include a marking characteristic for encoding information that is the spectroscopic signal of the substance from which the mark is formed. In particular where the coded marking is formed from nano-particles the characteristic that is used to identify the coded marking, e.g. to authenticate the coded marking, may be the spectroscopic signal of the nano-particles. The field of spectroscopy relates broadly to molecular energy levels of a substance.

The invention also provides an apparatus for reading a code carrier having a coded marking that passes through a detection zone or a reading zone spaced a distance from the apparatus, the apparatus including: a transmitter arrangement for transmitting an electromagnetic wave for causing the coded marking to emit an emission wave having an emission wavelength; a receiver arrangement for receiving the emitted waves from the substance of the coded marking and for converting the received waves into encoded output signals; and a decoder module for receiving the encoded output signals and for decoding the encoded output signals into decoded record information. The transmitter arrangement may have a wavelength associated with the absorption characteristic of a luminescent substance from which the coded fluorescent marking is formed, for triggering the luminescent substance to emit an emission wave having an emission wavelength.

The transmitter arrangement may have a wavelength associated with the absorption characteristic of a fluorescent substance from which the coded marking is formed, for triggering the fluorescent substance to emit an emission of waves having an emission wavelength.

The fluorescent code carrier may include a plurality of individual fluorescent marks formed from at least two selected fluorescent substances, in which case, the transmitter arrangement may be arranged to include at least two transmitters for transmitting at least two electromagnetic waves having wavelengths that correspond to the absorption wavelengths of the at least two selected fluorescent substances respectively.

The transmitter arrangement may include a focused light source for transmitting an incident beam of light across the distance to the detection zone, for triggering the fluorescent substance to emit an emission wave.

The focused light source may include a laser diode for transmitting a laser beam towards the detection zone.

The transmitter arrangement may include a transmitter lens, e.g. a telescopic lens, for expanding or narrowing the laser beam as required to conform to the detection zone. The focused light source may include a 2D optical scanner for sweeping the detection zone with the laser beam.

The focused light source may include a collimator for encouraging the rays of the laser beam to extend parallel to each other.

The receiver arrangement may include a receiver lens, e.g. a telescopic lens, for receiving the emitted waves from the fluorescent substance of the coded fluorescent marking in the detection zone. The telescopic lens may have a focal distance that is between 30 mm and 90 mm long.

The telescopic lens may include a lens aperture of between 12 mm and 25 mm.

Further, the receiver arrangement may include a dichroic mirror for screening the emitted waves from reflected light of the laser beam. The receiver arrangement may include interference filters for filtering ambient light from the emitted waves and the reflected light of the laser beam.

The laser diode may be a pulsed laser diode for transmitting a pulsed laser beam and for outputting a timing control signal relating to the pulse timing. The pulsed laser diode may be configured to transmit a pulsed laser beam comprising a wavelength of

500-600 nm and a pulse width of 1-10 ns. Further the laser may have a power of 60-140 milliWatt, e.g. 80-120 milliwatt.

The receiver arrangement may include a photomultiplier in form of an avalanche photodiode (APD) device that is gate-controllable for receiving a timing control signal from the laser diode. Instead, the receiver arrangement may include a photomultiplier in the form of a photon multiplier tube (PMT) device that is gate-controllable for receiving the timing control signal from the laser diode. The receiver arrangement may include a delay timer for delaying triggering of the gate of the photomultiplier relative to a laser pulse.

The receiver arrangement may include a photodetector in the form of an optical image device such as a charge-coupled device (CCD) for capturing an image of the fluorescent coded marking when it is triggered.

The apparatus may include a photodetector interface for transforming output signals of the photodetector, e.g. relating to the image of the fluorescent coded marking, into computer readable signals. The decoder module may receive the computer readable signals from the photodetector interface and decode the signals into decoded record information, e.g. intelligible information.

The decoder module may include a code key for decoding any one or more of the emission wave lengths, the shapes, the sizes, the layouts, and the patterns of the fluorescent marks into intelligible information.

To this end, the apparatus may provide a response module to output a desired response that is associated with the intelligible information obtained by the decoder module when the fluorescent marking is decoded. The response module may also output a response when a coded marking is authenticated. The response module may also output a false coded marking response, e.g. an alarm, when the marking cannot be authenticated.

The response module may include predetermined responses that are actuated when a coded fluorescent marking is successfully decoded.

The apparatus may include a computer system constituting the photodetector interface, the decoder module, and the response module. The computer system may include a user interface for visually displaying an image of the detected fluorescent marking and configuring the apparatus.

The invention also provides a method for reading a code carrier having a coded marking that passes through a detection zone or a reading zone spaced a distance from the apparatus, the method including: causing a substance from which a coded marking is formed to emit an emission wave having an emission wavelength; receiving the waves that are emitted by the substance of the coded marking; converting the received waves into coded output signals; and decoding the coded output signals into decoded record information.

The causing of the substance from which the coded marking is formed to emit an emission wave may include transmitting an electromagnetic wave towards the coded marking whereby to cause the wave to be absorbed by the substance and in response thereto emit said emission wave. The transmitting of an electromagnetic wave may include transmitting a wave having a wavelength associated with the absorption characteristic of the substance from which the coded marking is formed. The substance may be a fluorescent substance.

The transmitting may include transmitting a focused beam of laser light in the direction of the detection zone. The beam of laser light may be a pulsed beam of laser light.

The receiving may include identifying a property of a substance from which the coded marking is formed to confirm the authenticity of the coded marking.

The receiving may also include receiving an image of the coded marking on a photodetector, and the decoding may include subsequently decoding the individual and/or group marking characteristics of the coded marking to obtain record information, once the coded marking has been authenticated.

The decoding may include decoding individual fluorescent mark characteristics relating to the shape of the mark, the size of the mark, or the position of the mark relative to a reference point. The invention further provides an apparatus for producing a code carrier, which apparatus includes: an input arrangement for receiving information; an encoder module for converting the information into marking characteristics, according to a code; and an applicator arrangement for applying a fluorescent coded marking to a carrier surface of a code carrier body, which fluorescent coded marking includes the fluorescent marking characteristics.

The encoder may convert the information into fluorescent marking characteristics and the applicator arrangement may apply a coded fluorescent marking to the carrier surface based on the fluorescent marking characteristics.

The apparatus may include an information database for receiving a plurality of records having unique record information, in which case, the encoder module may convert the unique record information of each record into a uniquely coded fluorescent marking.

The encoder module may encode each record into a uniquely coded fluorescent marking by using a unique combination of group mark characteristics and/or individual mark characteristics as defined above.

The encoder module may include a code key generator for generating a code key that a decoder module may use to convert the uniquely coded fluorescent marking back to the unique record information that was encoded into the coded fluorescent marking.

The applicator arrangement may include a fluorescent printing device for printing the coded fluorescent marking onto the carrier surface of the carrier body.

The apparatus may include a computer system having a processor, a data memory, a program memory, peripherals, and the like. The computer system may also include computer readable instructions, which when executed by the computer system, constitutes part of the input arrangement, the encoder module, and the code key generator module. The records database may be formed by the data memory.

The invention further provides a method for producing a code carrier, which method includes: providing a code carrier body having a code carrier surface; encoding information into coded marking characteristics; and applying a coded marking onto the carrier surface that includes the code marking characteristics. The code carrier may be a fluorescent code carrier and the method may include encoding information into coded fluorescent marking characteristics and then applying a coded fluorescent marking to the carrier surface.

The method may include forming a plurality of individual fluorescent marks that constitute the fluorescent marking, and applying the individual fluorescent marks spaced on the carrier surface. Encoding the information may include selecting a plurality of marking characteristics for encoding information into the coded fluorescent marking.

Selecting marking characteristics may include selecting individual mark characteristics and/or selecting group mark characteristics. Selecting group mark characteristics may include selecting a number of fluorescent marks and/or selecting a spatial relationship of the marks relative to each other on the carrier surface.

Selecting individual mark characteristics may include selecting fluorescent characteristics of a mark, such as an absorption wavelength of the fluorescent substance from which the mark is formed and/or an emission wavelength of the fluorescent substance from which the mark is formed.

Selecting individual mark characteristics may include selecting a shape of the mark, and/or a size of the mark, and/or a position of the mark on the carrier surface relative to a predetermined reference point on the carrier surface. The method may include providing an additional record carrier, for example a magnetic strip-type record carrier on the carrier surface and/or an embedded RFID-tag, and/or an embedded nano-particle transponder within the carrier body.

Thus, the method may include masking a non-fluorescent record carrier with a coded fluorescent marking, for increasing the coding combinations that are available to the encoder.

The coded fluorescent marking may be formed from fluorescent substances that are characterized in that their emission signals strengths are different. Thus, the individual marking characteristics may include relative emission signal strength characteristics.

Encoding information into the coded fluorescent marking may also include a read sequence of the individual marks. In other words, a reading arrangement may be arranged for reading the individual fluorescent mark in a predetermined sequence, and the sequence may thus form a code layer for encoding information into the fluorescent marking.

Encoding information may include using combinations of the group mark characteristics and the individual mark characteristics to encode information into the fluorescent marking.

The invention yet further provides a code carrier system which includes: a plurality of code carriers, each code carrier including a unique coded fluorescent marking which is associated with a unique record; and at least one marking reader for reading the code carriers when they pass through a reading zone.

The code carrier may be a fluorescent code carrier and the marking reader may be for reading coded fluorescent markings on the code carrier. The system may include a fluorescent code carrier producing apparatus which may include any one or more of the optional features of an apparatus for producing a code carrier as herein defined, described, and illustrated.

The fluorescent code carrier may include any one or more of the optional features of a code carrier as herein defined, described, and illustrated. The fluorescent marking reader may include any one or more of the optional features of an apparatus for reading a fluorescent code carrier as herein defined, described, illustrated.

The system may include a plurality of readers that are spatially arranged relative to each other so as to be directed at different angles towards the reading zone for reading coded fluorescent marking facing different angles that pass through the reading zone.

According to even yet another aspect of the invention there is provided an apparatus for reading a code carrier, the apparatus including: a transmitter arrangement for transmitting at least one selected electromagnetic wave towards a surface of the article, the selected electromagnetic wave being selected to trigger at least one authentic luminescent substance forming an authentic luminescent marking; a receiver arrangement for detecting an emission wave if the predetermined authentic luminescent substance is present on the surface of the article and triggered by the selected electromagnetic wave, thereby to verify the authenticity of an article. The transmitter arrangement may transmit an electromagnetic wave that corresponds to the absorption wavelength of the luminescent substance forming the authentic marking. The receiver arrangement may be able to identify the substance from which the emission wave is emitted from an emission property of the emission wave.

The apparatus may include a further receiver arrangement for detecting an emission wave from the luminescent substance and for converting the received waves into encoded output signals. The apparatus also includes a decoder module for receiving the encoded output signals from the further receiver arrangement and decoding the output signals into decoded record information.

The further receiver arrangement may include an optical image device for capturing an image of the coded fluorescent marking from the emission wave. The transmitter arrangement may be arranged for transmitting a plurality of selected electrometric waves towards a surface of the article, the plurality of selected electromagnetic waves being selected to trigger a plurality of corresponding authentic fluorescent substances. The transmitter arrangement may be arranged for transmitting a plurality of selected electrometric waves in sequence towards a surface of the article, the plurality of selected electromagnetic waves being selected to trigger a plurality of corresponding authentic fluorescent substances in sequence.

The one and further receiver arrangements may be arrangements for detecting a plurality of emission waves emitted from the plurality of authentic fluorescent substances if they are present on the surface of the article and triggered by the plurality of selected electromagnetic waves.

The one and further receiver arrangements may include a photodetector and a photodetector interface for transforming output signals of the photodetector into computer readable signals.

The apparatus may include a decoder module may receive the computer readable signals from the photodetector interface and the decoder module may include a code key for decoding any one or more of the emission wave lengths, the shapes, the sizes, the layouts, and the patterns of the authentic fluorescent marking if the authentic fluorescent marking is present on surface of the article.

The apparatus may also include a response module and a computer system as defined in the preceding aspects of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A fluorescent code carrier and an apparatus for reading a code carrier as well as a fluorescent code carrier system, in accordance with this invention, may manifest itself in a variety of forms. It will be convenient to hereinafter describe several embodiments of the invention in detail with reference to the accompanying drawings. The purpose of providing this detailed description is to instruct persons having an interest in the subject matter of the invention how to carry the invention into practical effect. However it is to be clearly understood that the specific nature of this detailed description does not supersede the generality of the preceding broad description. In the accompanying diagrammatic drawings:

Figure 1 is a schematic drawing of a fluorescent code carrier system, in accordance with one embodiment of the invention; Figure 2 is a basic schematic block diagram of a fluorescent code reading apparatus in accordance with one embodiment of an apparatus showing the apparatus in basic functional terms;

Figure 3 is a basic schematic block diagram of a fluorescent code reading apparatus in accordance with another embodiment of the invention showing the apparatus in basic functional terms;

Figure 4 is a schematic front view of a code carrier carrying a coded fluorescent marking in accordance with one embodiment of the invention;

Figure 5 is a schematic front view of a code carrier carrying a coded fluorescent marking in accordance with another embodiment of the invention;

Figure 6 is a schematic drawing of a table setting out a plurality of code layers for encoding information onto a coded fluorescent marking on a code carrier in accordance with an example embodiment of the invention;

Figure 7 is a schematic front view of a code carrier carrying a coded fluorescent marking in accordance with yet another embodiment of the invention;

Figure 8 is a schematic front view of a code carrier carrying a coded fluorescent marking in accordance with yet another embodiment of the invention;

Figure 9 shows a basic functional block diagram of an apparatus in accordance with one embodiment of the invention for producing a fluorescent code carrier; Figure 10 shows one application of the code carrier system, in use;

Figure 11 shows another application of the code carrier system in use; and

Figure 12 shows yet application of a fluorescent code carrier having a record carrier on its surface, in use.

In Figure 1 reference numeral 10 refers generally to a code carrier system in accordance with one embodiment of the invention.

The system 10 includes broadly an apparatus for producing a code carrier (a code producing apparatus) 12 for producing a coded fluorescent marking that can be applied to a fluorescent code carrier 14, and an apparatus for reading a code carrier having a coded fluorescent marking (a code reading apparatus) 16 for reading the coded fluorescent marking on the carrier 14.

In this specification the term marking refers to a composite marking as a whole which often comprises a plurality of marks. By contrast the term mark refers to a single and individual mark forming a part of the overall composite marking.

The code producing apparatus 12 for producing the fluorescent code includes a computer system 18 in the form of a personal computer (PC). The computer system 18 contains a number of operating modules that will be described in more detail below. The code producing apparatus 12 also includes an applicator arrangement 20, that includes a fluorescent printer 22 including one or more printer cartridges. These cartridges contain fluorescent substances, e.g. dyes, for printing the coded markings on the code carrier. The computer system 18 includes a network interfacing module for connecting it to a network 11 , for example a LAN, WAN, or the Internet.

Broadly, the computer system 18 and the fluorescent printer 22 are used to encode information into a coded fluorescent marking comprising one or more coded fluorescent marks that are printed on the fluorescent code carrier 14 by means of the fluorescent printer 22. The information that is encoded is record information that is used for a variety of purposes some of which are described in more detail in the specific description below

The fluorescent code carrier 14 can then be applied to an article to tag or label the article. The code reading apparatus 16 can be used to detect and read the coded fluorescent marking on the code carrier 14, thereby to identify or authenticate the article to which it is applied. The reader apparatus 16 also includes a computer system 24, such as a reader PC, and one or more reading arrangements 26 for reading the coded fluorescent marking on the code carrier 14, as is explained in more detail below. The computer system 24 also includes a network interfacing module for connecting it to the network 11.

Figure 2 shows a basic schematic block diagram of a code reading apparatus in accordance with one embodiment of the invention for reading the coded fluorescent marking on the code carrier 14. The code reading apparatus, which is indicated generally by the reference numeral 16, is designed for reading a coded fluorescent marking (either in the form of a composite marking or a single mark) on a fluorescent code carrier 14, into which certain record information has been coded.

The reader apparatus 16 includes a reading arrangement 82 for reading the coded fluorescent marking.

The reading arrangement 82 includes a transmitter arrangement 84 for transmitting an electromagnetic wave or light source towards a reading zone where the fluorescent code carrier 14 and the coded fluorescent marking is located, and where the coded fluorescent marking is to be read. The transmitter arrangement 84 includes a radiation source, e.g. a light source, 86 for radiating electromagnetic radiation in the direction of the coded fluorescent marking. When the coded fluorescent marking receives the incident electromagnetic radiation, it excites or energizes the fluorescent molecules, and this initiates the fluorescence process causing the fluorescent material to emit or radiate a fluorescent signal. The nature of the fluorescent emission or signal that is given off depends on the fluorescent material that is used to form the fluorescent marking.

The example reader arrangement 82 in this embodiment is engineered to read the fluorescent properties of the fluorescent material used in the coded fluorescent marking. Explained another way the record information is encoded into the fluorescent properties of the fluorescent material that has been used as distinct from the shape of marks in the marking. With a barcode system, the material, e.g. ink, from which the bar codes are formed is not coded in this way.

A reader arrangement for reading a coded fluorescent marking in which the record information is encoded within visual features of the coded fluorescent marking is also contemplated and this will be described immediately below with reference to Figure 3.

In the Figure 2 embodiment, the transmitter arrangement 84 includes a light source that is a focused light source in the form of a laser. The laser 86 is pulse controlled, so that laser pulses are radiated or emitted in the direction of the reading zone. In one example reading apparatus 16 for reading fluorescent code the laser 86 is a pulsed laser having a wavelength of 530 nm, a pulse width of about 5 ns, and a repetition rate of about 10 kHz is used. The laser 86 might typically have an average power of 100 milliwatts.

The transmitter arrangement 84 also includes a telescopic optical system for conditioning the laser beam into a broad beam. The beam might typically illuminate a detection zone of about 0.5-4 m2.

The transmitter arrangement 84 also includes a scanner system which enables the transmitter arrangement to scan the reading or detection zone. In an example embodiment the focused light beam or source is directed though a scanner arrangement 87 in the form of a 2D optical scanner using fast spin mirrors. The use of a scanner is optional and in some applications e.g. where the fluorescent code carrier passes beneath a reader along a conveyor belt, may not be required.

The transmitter arrangement 84 also includes a collimator arrangement 88 for forming the light beam into a desired beam shape that is directed towards the reading zone where the code carrier 14 is expected to be located. The fluorescent material in the coded fluorescent marking emits a fluorescent pulse of electromagnetic radiation in response to the incident electromagnetic pulse from the laser that is absorbed by the fluorescent material. The nature of fluorescence is that a fluorescent beam or signal is emitted some time after the incident beam has been absorbed. There is a time delay between absorption of incident beam and emission of the fluorescent signal. The length of the time delay depends on the type of fluorophores used in the fluorescent code carrier. The delay might typically be of the order of 1-10 ns after the initial pulse is absorbed. In one example embodiment Rhodamine 6G is used as the fluorophore in the coded fluorescent coating. This fluorophore emits a fluorescent signal at a time that is about 3 ns after the incident laser beam is reflected by the code carrier.

The reading arrangement 82 further includes a receiver arrangement, generally indicated by reference numeral 90, for receiving the emitted electromagnetic radiation waves radiated by the fluorescent substances of the coded fluorescent marking 30 (the return fluorescent radiation), when stimulated or triggered by the transmitter arrangement 84.

The receiver arrangement 90 includes a lens 92 for collecting the return fluorescent radiation from the coded fluorescent marking. The lens 92 focuses the emitted waves from the fluorescent substance on a photo detector (photon detector) 98, e.g. to form an image.

The receiver arrangement 90 also includes an optical filter module 94 through which the return fluorescent radiation is passed before it reaches the photo detector 98. The purpose of the filter module 94 is to suppress background signals or non fluorescent signals from the target code carrier. The filer module includes components for carrying out spectral filtering and spatial filtering.

The filter module components for carrying out spectral filtering includes a bandpass filter through which the return beam including fluorescent signal is passed. The bandwidth filter has the effect of reducing the full spectral width of sunlight which is 800nm down to 40 nm thereby to achieve significant suppression of the ambient solar radiation. The module components might also include a dichroic mirror for selectively transmitting some incident radiation, e.g. light from the laser that is reflected off the article back to the receiver arrangement.

The spatial filtering components include a telescope system that only receives radiation from a narrow field of view that corresponds to the reading zone. The angular acceptance of the telescope is system is limited to about 50 milliradians. Further a variable iris aperture can also be used to carry out spatial filtering by limiting the field of view from which radiation can be received.

The photo detector includes an avalanche photodiode (APD) module 98. The

APD multiplies the signal many times once a basic threshold is reached. This amplifies the weak fluorescent signals emitted by the fluorescent substance. The APD 98 is pulse controlled by a pulse controller 100 to achieve time gating to help to shut out background signals.

The use of a time-gated photo detector enables fluorescent signals emitted by the fluorescent material to be admitted to the photo detector during short gate pulsed windows. In one form the timing of the opening and closing of the gate can be measured off the pulse rate of the focused light source 86. The short time period during which the gate is open to admit or receive the fluorescent beam or signal reduces the entry of optical noise signals into the photo detector 98. It also resists reflected light from the laser pulse (that triggers the fluorescent response and emission) from entering the photo detector 98 because this arrives at the photo detector 98 in advance of the fluorescent emission when the gate is closed. This increases the signal to noise ratio received within the photo detector enabling weak fluorescent signals to be detected and read by the photo detector. This enables the reader apparatus 16 to detect weak fluorescent signals even in high optical noise environments such as daylight where there is a significant amount of background solar radiation.

The return fluorescent radiation, e.g. signal, that has been detected by the photo detector is converted to detected signals which are ultimately used for decoding the fluorescent signal.

The detected signals are passed to a decoder module 102. The decoder module 102 uses the code key to interpret the detected signals and to convert the detected signals into the record information (e.g. that was originally coded into the fluorescent markings).

The reading arrangement 16 might typically also include a record database 104.

The record database 104 enables a user to look up the converted information (produced by decoding the detected signals) and compare it against the records of the database to ascertain whether or not the information is authentic.

A response module 106 forms part of the reading arrangement 16 and the response module 106 includes a response instruction database 108. The response module 106 is set up to output or generate a predetermined response that is associated with a valid fluorescent code marking that is detected. The precise nature of the response will depend on the application to which the fluorescent code is being put. The response module 106 will be used in applications such as authentication of articles, or tracking and identification of articles that are labelled with the fluorescent coded markings. Some modules of the reading apparatus that can be used to read the coded fluorescent markings are similar to those described in the Applicant's earlier International Patent Application, No. PCT/AU2006/000956 that has been published by WIPO as publication number WO/2007/003015. This specification is incorporated into this specification in its entirety by direct cross reference. In use, a pulsed incident beam from the laser 86 is directed at the code carrier 14.

The laser beam is reflected off the code carrier 14 back towards the reading arrangement 82. The fluorescent material emits a return fluorescent signal in response to excitation by the laser beam and this fluorescent signal travels back to the reading arrangement 82 after a certain time delay of the order of 1-10ns occasioned by the fluorescence lifetime. The spectral filters on the reading arrangement 82 filter out much of the background radiation including the reflected radiation from the laser pulse. The time based gating of the photo detector causes the gate to open at the correct time, to admit the fluorescent signal (which is delayed relative to the returning laser signal) and then to close shortly thereafter. The gate is only open for a brief period and this is important in achieving a high signal to noise ratio for the fluorescent signal. This enables the reader apparatus 16 to read fluorescent code carriers over relatively long distances which enhances the utility of the reading arrangement 82 and the system 10 as a whole.

The fluorescent signal that is received by the photo detector 98 is then processed into signals that can be decoded to transform the coded information back into the original record that was encoded into the code.

In another embodiment that is a variation on the embodiment described above a photo detector 98 that is in the form of a photomultiplier tube (PMT) device can be used.

Figure 3 shows a basic functional block diagram of a reading arrangement 80 in accordance with another embodiment of the invention. The reading arrangement 80 includes similar parts to the reader arrangement shown in Figure 2, and accordingly the same reference numerals will be used to refer to the same components unless otherwise indicated.

The reading apparatus 80 includes a photo detector arrangement 110 in the form of an image detector, e. g. an optical image device such as a charge-coupled device (CCD) for capturing an image of the fluorescent coded marking from the fluorescent emission waves emitted by the marking.

The image captured by the image detector is passed to a decoder 112 that interprets the image and converts it to the record information that was originally encoded in the coded fluorescent markings.

The captured image typically contains information relating to characteristics of individual marks (hereinafter called individual mark characteristics) such as the shape, and size of individual fluorescent marks (that form the fluorescent coded marking).

The captured image also contains information relating to the general layout and arrangement of the fluorescent marking made up of a group of marks, as a whole (hereinafter called group mark characteristics).

Similarly, the apparatus 80 includes a response module 106 and a response database 108 for outputting or generating an appropriate response that is associated with the article. This might be in the form of an alarm if a false or copied coded marking is detected. The alarm may be in the form of an audio and visual alarm, e.g. a red light and/or a beeper.

The reader 80 is engineered for reading a fluorescent code carrier 14 in which the record information has been completely encoded into visual features of a coded fluorescent marking. These visual features include both individual mark features and also group mark features, such as the layout, the shape, and the arrangement of the fluorescent marks.

In another embodiment that has not been separately illustrated the reader apparatus 16 includes a combination of the two reading apparatuses 80, 82 that are described above with reference to Figures 2 and 3. There are two reading arrangements, one of which reads the fluorescent properties of the fluorescent material in the coded fluorescent marking, and the other of which reads the visual features of the coded fluorescent marks such as the shape, the size, the position and the overall arrangement of the marks as a whole.

This would enable the reader as a whole to have the ability to read a fluorescent code carrier 14 on which the information was encoded in the fluorescent emission properties of the coded marking and also the visual image characteristics of the coded marking.

In this embodiment the reading arrangement 82 might firstly read the fluorescent signal that relates to the fluorescent properties of the coded marking. The fluorescent signal is decoded to determine whether or not it is the correct fluorescent material in the coded marking. This enables the reader to determine first of all whether the code carrier is authentic or whether it is false and copied. If it is not authenticated the response module 106 will indicate that there has been a violation of the system.

Once the code carrier 14 has been authenticated by the reading arrangement 80 the reading arrangement 82 can be used to read the visual shape properties of the coded fluorescent marking. An image of the visual shape properties is received and this is then decoded to provide the record information on the article to which the code carrier is applied. It will readily be appreciated that the initial reading of the fluorescent properties of the fluorescent material used to form the coded marking validates the code carrier before the coded marking is read and decoded to provide the record information. This adds an additional level of security that is not present in conventional barcode systems. This is particularly useful in applications where the security of the code is important.

Applicant envisages that this ability to read both fluorescent properties and visual characteristics of a coded fluorescent marking could be engineered to be provided within a single reading arrangement, particularly in commercial versions. However for ease and clarity of description in this specific description, the readers are drawn separately in the schematic drawing of the system.

Figure 4 shows a schematic representation of one embodiment of a fluorescent code carrier 14 in accordance with the invention. The fluorescent code carrier 14 includes a carrier body 28 having a carrier surface

29. Typically the carrier body 28 is in the form of a flattened body having two major surfaces one of which forms the carrier surface 29 for a coded fluorescent marking. The carrier body 28 can be formed from any material that is suitable for printing of fluorescent dyes thereon. In some forms the carrier body is made of paper or thin card, e.g. for application to an article.

The fluorescent code carrier 14 also includes a coded fluorescent marking 30 on the carrier surface 29. The coded fluorescent composite marking 30 is made up of a plurality of individual fluorescent marks 31 to 39, which are arranged in a specific spatial arrangement on the carrier surface 29, spaced apart from each other on the carrier surface 29.

The coded fluorescent marking 30 has a plurality of marking properties that can be used to encode record information (on the associated article to which the code carrier 14 is applied) in the marking 30.

The coded fluorescent marking properties are divided into two main groups. One group is individual marking characteristics which include marking characteristics that relate to characteristics or features intrinsic to an individual mark. The individual marking characteristics relate to characteristics of a single mark as distinct from characteristics of a group of marks or the composite marking as a whole. One example of an individual marking characteristic is the shape of a mark. Another individual marking characteristic is the size of a mark. Yet another individual marking characteristic is the colour of a mark.

The other group of characteristics is group marking characteristics that relate to the arrangement of the marks as a group in the marking as a whole. The group marking characteristics relate more to the relative arrangement of the marks to each other, than a single mark viewed in isolation. One example of a group marking characteristic is the overall layout of the group of marks. Another group characteristic is the shape of the group of marks when viewed as a whole.

The individual and group marking properties are both used to contribute to the coding that is used to encode information into the coded fluorescent coded marking.

In Figure 4 the coded fluorescent marking includes marks of different shapes. Some of the individual marks are triangles. Other individual marks are rectangles and other individual marks are circles. The arrangement of the different shapes of individual marks relative to each other is not regular. Further the spatial arrangement of the individual marks relative to each other is not in the form of a regular pattern and this arrangement can code information. Thus the characteristics of shape and pattern of the fluorescent mark can be used to code information (shape and pattern characteristics). In addition characteristics relating to the fluorescence of the fluorescent marks can be used to encode information into the marking 30 (fluorescence characteristics).

Moreover, by selecting different types of fluorescent substances to form the fluorescent marks, each with their own fluorescent properties, different levels of coding relating to the fluorescent materials used for the marks can be introduced.

A code can be made up of a number of code layers 45. Each code layer can include a plurality of code elements that relate to the different mark properties for that layer. An encoder can then use these mark properties to create unique codes. The group of fluorescent marks 31 to 39 possesses certain group mark properties.

One group mark property is defined by the number of fluorescent marks, in this case, nine. Different numbers of fluorescent marks can thus be used to create unique code elements.

In this example embodiment, each fluorescent mark 31 to 39 is formed from a different fluorescent substance. The fluorescent substances are selected to have the same absorption wavelength, but have different Stoke-shifts, so that their emission wavelengths are different. The fact that the absorption wavelengths are the same is advantageous because only one light source is required to energise or trigger all of the fluorescent marks. Each mark in turn then emits its unique fluorescent light signal that is a function of the fluorescent material or fluorescent substance that is fluorescing. The combination of all of these fluorescent signals forms a complex signal or signature that can be read by the reading arrangement.

Further in this regard, the fluorescent marks can also be formed from fluorescent substances that have different signal emission strengths which can also form part of the individual mark properties into which information is encoded. Yet further, a mark sequence can also be used to encode information. These additional properties of sequence and emission signal strength can form other code layers.

In another example embodiment a number of different fluorescent substances are used to form a coded fluorescent marking that has different absorption wavelengths. In that case the transmitter arrangement can be arranged to transmit different electromagnetic waves corresponding to the different absorption wavelengths of the fluorescent substances.

Figure 5 shows a schematic representation of another embodiment of a fluorescent code carrier 14 in accordance with the invention. As Figure 5 has some similarities with the code carrier described above with reference to Figure 4 the same reference numerals will be used to refer to the same components unless otherwise indicated.

The main difference between the Figure 5 embodiment and the Figure 4. embodiment described above is that the composite coded marking in Figure 5 also includes other marks 40 that are not printed with a fluorescent substance.

These non-fluorescent coded markings are indicated generally by the reference numeral 40 and are printed with a coloured ink, for example a black ink. Ink marks are printed onto the carrier surface with conventional ink, are well known to be used for encoding information on labels, for example barcodes. The code carrier 14 in Figure 5 is delineated into a matrix having four rows and seven columns defining twenty eight cells or matrix spaces within the matrix. Some of the cells have ink printed on them and other cells are deliberately left free of ink. The properties of the ink marks are used to encode information into the ink marking.

For example the choice of cells that are inked in with ink and those that are left free of ink can be used to encode coding information into the composite coded marking. Further properties of the ink marks, such as their shape, dimension, and position can also be used to encode information into the ink marking.

Thus the ink marks form a two dimensional printed code that adds more code levels to the code and contributes to the encoding of information in the composite coded marking.

Figure 6 shows an example of how different code layers can be used to build up a complex code having many layers of code. The code layers are presented in the form of a table with different code layers that together make up the overall code.

One code layer is number code layer 46 which relates to the number of particles that are used to form the code. The code layer 46 includes an array of numbers 46.1 from which the encoder can select to form the code entry for this layer.

Another code layer 48 relates to the pattern that is used for the composite mark.

This code layer refers to the layout or patterns formed by the arrangement of the marks relative to each other. There is an array of patterns 48.1 for each possible pattern that can be used. This is a group mark property or a property of the overall composite mark as distinct from a property of an individual mark.

The code also includes a shape code layer indicated by numeral 50 and there is an array of shapes 50.1 for each of the shapes that can be used that belong to a shape code layer 50. The shape code layer refers to the shape property 50.1 of a mark which is an individual mark property. For example in the illustrated embodiment, the fluorescent marks 33 are circular, the fluorescent marks 37 are rectangular, and the fluorescent marks 39 are triangular. There is an array of shapes 50.1 for each of the shapes that can be used that belong to a shape code layer 50.

The code also includes a position code layer that is indicated by the reference numeral 52. The individual marks each have an individual mark property that relates to the individual position of each mark e.g. typically measured with reference to a predetermined reference point 53. There is an array of positions 52.1 for each of the positions that can be adopted by the marks in the coded marking.

The fluorescent marks are formed from fluorescent substances or dyes. Thus, in addition to the characteristics of number, shape, position, and pattern, that are achievable with ink marks, a plurality of new code dimensions can be added to the marking using the fluorescent characteristics of the fluorescent marks. For example this could include a fluorescent material characteristic including any of those discussed above.

When a fluorescent mark is energized by a beam of electromagnetic radiation, it emits a fluorescent signal in response to the incident beam of electromagnetic radiation. The fluorescent signal is a property of the fluorescent material or substance that emits the signal. Accordingly the code can include a fluorescent material code layer that can be encoded into the fluorescent marking.

It is possible to form the marks from many different types of fluorescent substances that have different absorption wavelengths and/or different emission wavelengths. Therefore many code layers can be created by selecting different fluorescent substances. The number of absorption and emission properties that are available for encoding information into the fluorescent marking can be increased by increasing the number of fluorescent substances that are used to form the fluorescent marks the number of absorption and emission properties that are available for encoding information into the fluorescent marking are also increased.

Further individual mark properties that relate to the fluorescent material that is used include an absorption wavelength of the fluorescent substance from which the mark is formed, and an emission wavelength of the fluorescent substance from which the mark is formed.

The absorption wavelengths thus form individual marking properties 54.1 that belong to an absorption code layer 54, and the emission wavelength properties 56.1 belong to an emission code layer 56 that contribute to the code layers 45.

Another code layer 57 could be formed by the sequence of reading the different fluorescent signals 57.1. There can be an array of numbers 57.1 corresponding to each possible sequence of fluorescent emission. Another code layer could be directed to reading the signal strengths of the fluorescent emissions of the different fluorescent materials.

Further while the fluorescent marks that are illustrated in the drawings are shown as being visible to the human eye it should be borne in mind that some fluorescent marks

31 , 35 can be formed from a transparent fluorescent substance, so that they are invisible to the naked eye. These invisible markings can equally be used to carry out this invention.

Thus, information can be encoded into the coded fluorescent marking by using the properties of individual marks as well as group mark properties which are properties of the group of marks in the composite marking.

Figure 7 shows a fluorescent coded carrier 130 in accordance with another embodiment of the invention.

The code carrier 130 includes a marking comprising individual fluorescent marks 31 , 33 of different shapes arranged a certain spatial array on the carrier 130. These marks 31 , 33 have been described in some detail above with reference to Figure 4.

In Figure 7, the code carrier 130 also includes on its carrier surface an additional record carrier in the form of a magnetic strip 132 in addition to the fluorescent marks 31 , 33.

The use of an additional record carrier that is the magnetic strip 132, in combination with the fluorescent markings 31 , 33 increases the available code layers in the code that is encoded on the code carrier 30 for encoding information. The magnetic strip helps to make the code carrier more secure in the sense that it is harder for an unauthorized person to decipher the code and then misuse it. In addition to having to overcome the fluorescent code such a person would also have to decode the code that is used on the magnetic strip.

This code carrier 130 could be used in applications requiring a high level of security. These could include bank card applications, passports, and driving licenses Figure 8 illustrates schematically a fluorescent code carrier 134 in accordance with yet another embodiment of the invention.

The fluorescent code carrier 134 includes an arrangement of fluorescent marks 31 , 33 like the code carrier described above with reference to Figure 4.

The fluorescent code carrier 134 also includes an embedded record carrier 136 on or within the body of the code carrier that is in the form of a nano-particle transponder 136.

The embedded record carrier 136 adds another code layer to the code for encoding information. This adds another level of security because the nano-particle transponder has to be decoded in addition to the fluorescent code carrier. The nano-particle transponder can be authenticated by reading its spectroscopic signal, which forms a unique signature that can be used for authentication. Further reading the spectroscopic signal may include selectively analysing, certain features of or points on, the spectroscopic signature for the particular nano-particle transponder that is used. This additional record carrier in the form of a magnetic strip helps to make the code carrier more secure in the sense that it is harder for an unauthorized person to decipher the code and then copy and misuse it. In addition to having to decipher the fluorescent code characteristic, such a person would also have to decode the spectral signature of the nano-particle transponder, and the way in which this is analysed in the authentication process. It will be appreciated that this will be a very difficult task to accomplish even for a sophisticated user.

This code carrier 134 could be used in applications requiring an even higher level of security than those for which the Figure 7 carrier is used. These could include bank card applications, passports, and driving licenses.

Figure 9 shows a basic functional block diagram of an apparatus 12 for producing a fluorescent code carrier 14 of the general type described above with reference to Figures 4, 5, 7 and 8.

Broadly the apparatus 12 includes an input arrangement 60 and an information database for receiving and storing information on the article to which the fluorescent code is to be applied. The apparatus also includes an encoder module for encoding the information on the article to be encoded into the fluorescent markings and an associated code key generator containing the rules for encoding information. Finally the apparatus also includes an applicator for applying the fluorescent code markings to the code carrier. Each of these components will now be described in more detail below.

The input arrangement contains an interface for facilitating the entry or input by a user of article information that is to be encoded into a fluorescent coded marking 30. The marking 30 is to be applied to a fluorescent code carrier 14 which is then applied to the relevant article. The information database 64 which is operatively coupled to the input arrangement is populated with a plurality of records that have been entered for fluorescent code markings, of which two are shown as 66, and 68. Each one of the records 66, 68 includes unique record information, for example information of an associated clothing article or a piece of cargo or inventory that is to be marked with a unique coded fluorescent marking.

The encoder module 62 is operatively coupled to the information database and performs the function of converting the unique record information of each record into a coded fluorescent marking 30. The encoder module 62 uses a unique combination of the code layers 46 to 57, and unique combinations of the code elements 46.1 to 57.1 of each code layer, 46 to 57, to encode the information on the article into the properties of a unique fluorescent code marking 30.

The apparatus 12 further includes a code key generator 70 that is operatively coupled to the encoder module. The code key generator 70 includes the set of code rules or code schema that is used for encoding the information that are used to convert the information on the article into an image of individual mark characteristics and also a set of group mark properties.

The apparatus 12 includes the applicator arrangement or fluorescent printing device 20 for applying the fluorescent marks to the carrier surface of a code carrier body 28. In this example, the fluorescent printing device includes nine cartridges that contain nine different fluorescent dyes. The fluorescent printing device 20 prints the fluorescent image containing the fluorescent code onto a code carrier that conveniently can be in the form of a label that is applied to the article, e.g. which is stuck onto the article by adhesive on a backing layer of the label. Finally the apparatus also includes a decoder module that is operatively coupled to the code key generator. This information can then be used by the decoder module to decode the uniquely coded fluorescent mark and convent them into the information on the article that was originally recorded.

The apparatus 12 for producing the code carrier physically formed by a PC 18 and a set of peripheral modules operatively connected thereto such as a printer. The PC 12 also includes a set of computer readable instructions that are executed by the PC, that form part of the modules and arrangements of the apparatus 12.

In use, a plurality of articles can be uniquely marked or labelled with the fluorescent code carriers 14, and uniquely identified using the fluorescent marking readers 16, 80.

The PC 18 has an encoder software application that is executed and that includes the code generator. For example, the encoder software application includes a setup application for a user to specify the number of records that are to be encoded into unique fluorescent code markings and for setting the marking properties that are available for encoding information into the fluorescent code markings.

In this example, the marking properties include nine available fluorescent emission waves from the nine available fluorescent dyes in the printer cartridges. Also, the carrier surface is divided conceptually into an array or matrix having a plurality of cells within which fluorescent marks may be printed. A number of marking shapes are also set for the encoder to use for encoding information. Thus, a multi-dimensional or multi-layer code can be formed by using all the set marking properties.

The encoder application creates for each record a unique combination of marking properties in each code layer. Thereafter, the fluorescent marks are printed on an appropriate printing medium with the fluorescent printer 22. Figure 10 illustrates an embodiment of the code carrier system 10 in accordance with the invention that is applied to an article tracking system in a logistics environment. Specifically the system 10 is employed as a stock-control system in a packaging facility.

The carrier bodies 14 are provided by a printing paper that has a self-adhering surface to form sticky labels. The labels are applied to packaging containers 120. Each container or stock item 120 is tagged with a uniquely encoded fluorescent code marking 14. The records are logged into a record database.

Three readers 26 are mounted on a support structure 122 and the readers 26 are directed towards a read zone or detection zone defined between the limbs of the support structure 122. The three readers 26 are positioned spaced apart on the support structure 122 and therefore face in different directions towards the reading zone. This enables the readers 26 to read fluorescent code carriers 14 facing in more than one direction. As discussed above the readers 26 need line of sight to read the carriers 14.

As the containers 120 pass though the reading zone, at least one of the readers 26 triggers the fluorescent marking on the container 120, which fluorescent marking emits its signals. The signals are detected by the photo detector, e.g. the PIN diode, and the signals are passed to the decoder for further processing. At this stage, the record database can be updated, or other responses can be generated as the case may be, for example delivery way bills can be automatically generated and printed. Figure 11 illustrates a code carrier system in accordance with another embodiment of the invention in another application where it is used to apply authenticity marks to clothing.

A fluorescent code carrier 14 for clothing articles is made and is attached to an associated clothing article 126, so that the clothing article bears a unique fluorescent mark.

The reading arrangement in this example application is a hand-held reader 80.

The reading arrangement includes either a CCD for detecting an image of the fluorescent marking or a detected signal corresponding to an identifying property of the fluorescent substance forming the marking. The fluorescent substance from which the marking is formed may be secret and may be used to authenticate the article as genuine goods.

The image is unique and is applied as an authenticity mark to the article by the manufacturer. The image is passed to the decoder module and interpreted and decoded to form record information. The record information is then checked against the records in the record database for authentication, and if successfully verified, triggers a healthy response. Figure 12 shows a code carrier system 140 in accordance with another embodiment of the invention that is applied to a code carrier 134 having a fluorescent code and a nano-particle transponder.

The system 140 has a reader apparatus 142 includes a reading arrangement 144 having a reader 146 for reading the coded carrier 134. Thus, the reader 164 is able to read both fluorescent marking and the embedded nano-particle transponder.

The code carrier system described above with reference to the drawings uses a fluorescent substance for encoding fluorescent markings. A key feature of this system is that the coded fluorescent marking emits emission waves that is received as distinct from reflected light that is radiated by a light source.

An advantage of the code carrier system described above is that it is capable of a greater level of security than barcode systems and thereby is less likely to be deciphered and subject to breach and misuse than a barcode system. The use of coded fluorescent markings containing one or more code layers relating to the fluorescent substance of the coded marking adds another dimension of coding to the code carrier over and above the visual coding properties. These include the absorption wavelength of the fluorescent material from which the mark is formed and the emission wavelength of the fluorescent signal issued by the fluorescent material.

Another advantage of the code carrier system described above with reference to the drawings is that it enables multiple layers of code to be used. In addition to layers of code that relate to number, shape, position, and pattern of coded markings, additional layers of code that relate to the fluorescent properties of the fluorescent material can be added. Another advantage is that a large number of different types of fluorescent dyes can be used for forming the fluorescent marks, which provides a large number of encoding possibilities. The record carrier thus advantageously provides a high level multidimensional code carrier that is cost efficient, and is secure.

Another advantage of the code carrier system and particularly the apparatus for reading the code carrier described above is that it is capable of reading the code on a code carrier from a significantly greater distance than is the case for a barcode reader. The reason for this is that the fluorescent wave signals emitted by the fluorescent code material can be more effectively separated from other light than light issuing from a code carrier formed by normal dye, than reflected radiation. This enables a relatively smaller or weaker signal to be read from a further distance than is possible with a visual barcode printed in ink. In particular the use of a time-gated controlling of the APD in conjunction with a corresponding pulse from the laser source helps to screen out ambient light and background solar radiation. The APD is timed to open briefly within a certain time interval after the pulse is radiated by the laser source. This timed opening and closing of a gate permits a detection of weak fluorescent signals, even in optically noisy environments.

The Applicant believes that the fluorescent dyes used for forming the code carrier are generally less expensive than conventional record carriers such as RFID tags. The applicant believes that the system described above offers cost benefits over RFID systems while still offering a high level of security. Another advantage of the invention is that coded fluorescent markings can be used to mask existing record carriers, such as barcodes or magnetic strips, thereby adding an additional level of information for authenticating articles.

An advantage of the code carrying system described above is that it is particularly suitable for application to article tracking in logistics operations. The capability of the system enables the code carrier to be read by a reading arrangement distances of over 2 metres thereby conferring advantages over barcode systems in this application.

Another advantage of the code carrying system described above is that it is particularly suitable for article authentication. An article can be authenticated by reading the fluorescent code on the code carrier on the article to identify if it is a genuine article or if it is a counterfeit article.

An advantage of the code carrying system described above is that it is particularly suitable for use in applications requiring high levels of security. The system potentially has many code layers available for use in coding which enables encoder to created complex codes that are very secure. It will of course be realized that the above has been given only by way of illustrative example of the invention and that all such modifications and variations thereto, as would be apparent to persons skilled in the art, are deemed to fall within the broad scope and ambit of the invention as is herein set forth.

Claims

CLAIMS:

1. A code carrier which includes: a carrier body having a carrier surface; and a coded marking on the carrier surface that emits a code signal in the form of an electromagnetic radiation in response to a stimulus.

2. A code carrier as claimed in claim 1 , in which the coded marking on carrier surface emits a luminescent signal as a result of luminescence.

3. A code carrier as claimed in claim 1 or claim 2, in which the stimulus is provided by an incident beam of electromagnetic radiation.

4. A code carrier as claimed in claim 2, in which the coded marking is a fluorescent marking.

5. A code carrier as claimed in claim 4, which each coded marking includes a plurality of fluorescent marks that are spaced apart on the carrier surface.

6. A code carrier as claimed in claim 4, in which the coded fluorescent marking includes a plurality of unique marking characteristics for encoding information into the coded fluorescent marking.

7. A code carrier as claimed in claim 6, in which the coded fluorescent marking includes a plurality of individual fluorescent marks, each individual fluorescent mark including at least one individual mark characteristic for encoding information into the coded fluorescent marking.

8. A code carrier as claimed in claim 7, in which at least one of the individual fluorescent mark characteristics that is used for encoding information into the coded fluorescent marking, includes a fluorescent mark characteristic of the fluorescence substance forming the individual fluorescent mark.

9. A code carrier as claimed in claim 8, in which the fluorescent mark characteristic includes a trigger wavelength of the fluorescence substance forming the individual fluorescent mark.

10. A code carrier as claimed in claim 8, in which the fluorescent mark characteristic includes an emission wavelength of the fluorescence substance forming the individual fluorescent mark.

11. A code carrier as claimed in claim 8, in which the fluorescent mark characteristic includes an absorption wavelength of the fluorescence substance forming the individual fluorescent mark.

12. A code carrier as claimed in claim 8, in which the fluorescent mark characteristic includes a Stokes-shift of the fluorescence substance forming the individual fluorescent mark.

13. A code carrier as claimed in claim 8, in which the individual fluorescent mark characteristic that is used for encoding information into the coded fluorescent marking includes an outline shape of the individual fluorescent mark.

14. A code carrier as claimed in claim 8 in which the individual fluorescent mark characteristic that is used for encoding information into the coded fluorescent marking includes the size and dimension of the individual fluorescent mark.

15. A code carrier as claimed in claim 8, in which the individual fluorescent mark characteristic that is used for encoding information into the coded fluorescent marking includes a position of the individual fluorescent mark on the carrier surface relative to a predetermined reference point on the carrier surface.

16. A code carrier as claimed in claim 15, in which the coded fluorescent marking includes a group of fluorescent marks, each group of individual fluorescent marks including at least one group mark characteristic for encoding information into the coded fluorescent marking.

17. A code carrier as claimed in claim 16, in which the at least one group mark characteristic includes a pattern formed by the spatial arrangement of the members of the group of individual fluorescent marks relative to each other.

18. A code carrier as claimed in claim 17, in which the at least one group mark characteristic includes the number of members in the group of individual fluorescent marks.

19. A code carrier as claimed in claim 17, in which the different fluorescent marks within the marking are formed from at least two different types of fluorescent material.

20. A code carrier as claimed in claim 19, in which the fluorescent material used in the fluorescent marks is formed from a mixture of at least two types of fluorescent substances.

21. A code carrier as claimed in claim 20, in which the type of fluorescent substance of which the fluorescent marks are formed includes a transparent fluorescent substance, so that it is substantially invisible to the naked human eye.

22. A code carrier as claimed in claim 21 , which includes individual marking characteristics and/or group marking characteristics selected according to a set of code rules forming a code scheme for converting information into the individual marking characteristics and/or group marking characteristics.

23. A code carrier as claimed in claim 22, which includes at least one additional record carrier that is selected from the group comprising: an encoded non-fluorescent marking, a bar code, a magnetic strip-type record carrier, an embedded RFID-tag, and an embedded nano-particle transponder.

24. A code carrier as claimed in claim 23, in which the carrier body is formed from a sheet material defining the carrier surface, the coded fluorescent marking being printed on the carrier surface.

25. A code carrier as claimed in claim 23, in which the carrier body includes a tag for attachment to an article of clothing.

26. A code carrier as claimed in claim 25, in which the carrier body includes a self- adhering label for sticking to an article.

27. A code carrier as claimed in claim 1 , in which the coded marking is formed by a nano-particle based marking.

28. A code carrier as claimed in claim 28, wherein the nano particle based marking comprises inorganic semiconductor nano-particles.

29. A code carrier as claimed in claim 27 or claim 28, wherein the nano particle based marking includes a marking characteristic for encoding information, and the marking characteristic includes the spectroscopic signal of the substance from which the mark is formed.

30. An apparatus for reading a code carrier having a coded marking that passes through a detection zone spaced a distance from the apparatus, the apparatus including: a transmitter arrangement for transmitting an electromagnetic wave for causing the coded marking to emit an emission wave having an emission wavelength; a receiver arrangement for receiving the emitted waves from the coded marking and for converting the received waves into encoded output signals; and a decoder module for receiving the encoded output signals and for decoding the encoded output signals into decoded record information.

31. An apparatus for reading a code carrier according to claim 30, wherein the transmitter arrangement has a wavelength associated with the absorption characteristic of a luminescent substance from which the coded marking is formed, for triggering the luminescent substance to emit an emission wave having the emission wavelength.

32. An apparatus for reading a code carrier according to claim 31 , wherein the transmitter arrangement has a wavelength associated with the absorption characteristic of a fluorescent substance from which the coded marking is formed, for triggering the fluorescent substance to emit an emission wave having the emission wavelength;

33. An apparatus as claimed in claim 32, in which the fluorescent code carrier includes a plurality of individual fluorescent marks formed from at least two selected fluorescent substances, and in which the transmitter arrangement is arranged to transmit at least two electromagnetic waves having wavelengths that correspond to the absorption wavelengths of the at least two selected fluorescent substances respectively.

34. An apparatus as claimed in claim 33, in which the transmitter arrangement includes a focused light source for transmitting an incident beam of light across the distance to the detection zone, for triggering the fluorescent substance to emit an emission wave.

35. An apparatus as claimed in claim 34, in which the focused light source includes a laser diode for transmitting a laser beam toward the detection zone.

36. An apparatus as claimed in claim 35, in which the focused light source includes a 2D optical scanner for sweeping the detection zone with the laser beam.

37. An apparatus as claimed in claim 36, in which the focused light source includes a collimator for restraining the laser beam within the detection zone.

38. An apparatus as claimed in claim 37, in which the receiver arrangement includes a telescopic lense for receiving the emitted waves from the fluorescent substance of the coded fluorescent marking in the detection zone.

39. An apparatus as claimed in claim 38, in which the receiver arrangement includes a dichroic mirror for screening the emitted waves from reflected light of the laser beam.

40. An apparatus as claimed in claim 39, in which the receiver arrangement includes interference filters for filtering ambient light from the emitted waves and the reflected light of the laser beam.

41. An apparatus as claimed in claim 40, in which the lased diode is a pulsed laser diode for transmitting a pulsed laser beam and for outputting a timing control signal relating to the pulse timing .

42. An apparatus as claimed in claim 41 , in which the pulsed laser diode is configured to transmit a pulsed laser beam comprising a pulsewidth of 1-10ns.

43. An apparatus as claimed in claim 42, in which the receiver arrangement includes a photomultiplier in form of an avalanche photodiode (APD) device that are gate- controllable for receiving the timing control signal from the laser diode.

44. An apparatus as claimed in claim 43, in which the receiver arrangement includes a photomultiplier in the form of a photon multiplier tube (PMT) device that is gate- controllable for receiving the timing control signal from the laser diode.

45. An apparatus as claimed in claim 43 or 44, in which the receiver arrangement includes a photodetector in the form of a charge-coupled device (CCD) for capturing an image of the coded fluorescent marking when it is triggered.

46. An apparatus as claimed in any one of claims 43 to 44, in which the receiver arrangement includes a delay timer for delaying triggering of the gate of the photomultiplier relative to a laser pulse.

47. An apparatus as claimed in claim 43, which includes a photodetector interface for transforming output signals of the photodetector into computer readable signals.

48. An apparatus as claimed in claim 47, in which the decoder module receives the computer readable signals from the photodetector interface and decodes the signals into intelligible information.

49. An apparatus as claimed in claim 48, in which the decoder module includes a code key for decoding any one or more of the emission wave lengths, the shapes, the sizes, the layouts, and the patterns of the fluorescent marks into intelligible information.

50. An apparatus as claimed in claim 49, which includes a response module to output a desired response that is associated with the intelligible information obtained by the decoder module when the fluorescent marking is decoded.

51. An apparatus as claimed in claim 50, in which the response module includes predetermined responses that are actuated when a coded fluorescent marking is successfully decoded.

52. An apparatus as claimed in claim 51 , in which the apparatus includes a computer system constituting the photodetector interface, the decoder module, and the response module.

53. An apparatus as claimed in claim 52, in which the computer system includes a user interface for visually displaying an image of the detected fluorescent marking.

54. An apparatus for authentication, the apparatus including: a transmitter arrangement for transmitting at least one selected electromagnetic wave towards a surface of the article, the selected electromagnetic wave being selected to trigger at least one authentic luminescent substance forming an authentic luminescent marking; a receiver arrangement for detecting an emission wave if the predetermined authentic luminescent substance is present on the surface of the article and triggered by the selected electromagnetic wave, thereby to verifying the authenticity of an article.

55. An apparatus as claimed in claim 54, in which the transmitter arrangement transmits an electromagnetic wave that corresponds to the absorption wavelength of the luminescent substance forming the authentic marking.

56. An apparatus as claimed in claim 54 or claim 55, in which the receiver arrangement can identify the substance from which the emission wave is emitted from am emission property of the emission wave.

57. An apparatus as claimed in any one of claims 54 to 56, including a further receiver arrangement for detecting an emission wave from the luminescent substance and for converting the received waves into encoded output signals, and a decoder module for receiving the encoded output signals from the further receiver arrangement and decoding the output signals into decoded record information.

58. An apparatus as claimed in claim 57, in which the further receiver arrangement includes an optical image device for capturing an image of the coded fluorescent marking from the emission wave.