JP2007004572A - Method for uniquely marking object using spectral emitter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a security marker having a unique characteristic corresponding to a database entry. <P>SOLUTION: The marker comprises at least one nanocrystalline quantum dot emitter, and the unique characteristic of the marker is the unique emission profile of the at least one nanocrystalline quantum dot emitter. The marker stores a unique number in the form of the unique emission profile that can be read without the need for detailed chemical analysis of the marker. The object is marked with the security marker and such maker is then read. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates generally to the use of unique markers in tagging objects, and more specifically to the use of markers adapted to generate unique emission profiles.

  Security tagging and origin marking are important tools used by private manufacturers to control the spread of their products. By attaching a unique identification marker to his / her product, the manufacturer can enable discrimination between counterfeit products and his / her own products.

  Security tagging is also very valuable to those who want to tag their property so that if a theft occurs, their property can be easily identified.

  In order for any security tagging or origin marking system to be used on a fairly large scale, there must first exist a system that generates a large number of unique numbers. In this regard, one such system that generates and manages a number of unique numbers is disclosed in UK Patent Application No. 0508507.1.

  When a unique number is generated, a mechanism must be selected that stores each number independently.

  At the simplest level, the unique number may simply be reprinted, for example, on a very small size on a small dot. These uniquely numbered microdots can then be attached to the object (s) to be marked. One drawback of this mechanism is the obvious way in which unique numbers are stored and presented.

  It is preferable to store unique numbers with a more concealed mechanism, which requires a key to interpret the stored numbers. In one way in which a unique number may be stored in the form of a binary string, the binary string may be the presence of a certain compound in the marker (result of “1”) or non-existence (“ 0 ").

  A major drawback of the system arises when chemically analyzing which compounds are actually present on the marker. The process required to chemically test the marker to determine which compounds are present on the marker can be expensive and the analysis itself can be time consuming. is there.

[Summary of Invention]
In view of the limitations of the prior art, the present invention provides a unique marker according to claim 1 and a method for uniquely marking and identifying an object according to claim 6. The present invention describes a marker that can be read instantly and without the need for chemical analysis. The present invention also provides a method for marking an object and then reading such markers.

  The present invention is based on the use of nanocrystalline quantum dot emitters and the emission frequencies are sufficiently separated to be detected and resolved by a hand-held detector. Suitable nanocrystalline quantum dot emitters are ZnS, ZnSe, ZnTe, CdS, CdSe, CdTe, GaN, GaP, GaAs, GaSb, InP, InAs, InSb, AlS, AlP, AlSb, PbS, PbSe, Ge, Si, And ternary and quaternary mixtures thereof.

  I. InP, InAs, InSb, PbS, and PbSe. R. Combinations of quantum dots that emit in a region may be used as well as quantum dots from other spectral regions.

  A combination of infrared emitting quantum dots, each with a specific emission frequency and used in conjunction with a specially developed hand-held, battery-operated infrared detector, identifies unique codes attached to various surfaces Provide enough information.

  Infrared emitting quantum dots were selected because there is already a global industry that mass-produces infrared sensors to remotely operate large arrays of different items. By combining this low unit cost industry with the new quantum dot concept, systems have been created that are cost effective and provide a quick way to trace marked items.

  Quantum dots can be incorporated into polymer supports to provide water stability. These materials may then be added to a water-based polymer emulsion that also contains visible emitting quantum dots to serve as an indicator of the position of the encoded marker on the surface of the article.

  Quantum dots have been identified that have the correct physical dimensions to provide an emission peak half-width that is small enough to facilitate both separation and identification of different wavelengths. They are manufactured to emit in the infrared range of 1-1000 microns.

  The present invention also provides a way in which an item is marked after manufacture by a supplier or customer, but the item is marked during manufacture so that the nature of the product is verified and traceable. It is also possible to be attached.

  The level of formulation complexity used is a key feature of the invention, as is the detector (s) used to determine that a fingerprint is present. Using a suitable detector for each region, a yes / no qualitative response or material ratio found when quantitative techniques are used is provided.

The result from the detector can be processed in several ways.
i) The result is used locally to determine the information on the item being scanned.
ii) The results are used in conjunction with a remote database so that questions are asked through the necessary security measures.

  The first approach would include a scanner that includes the necessary detector elements and an ultraviolet lamp that acts as a stimulant for the emission. This is used for concealed applications and indicates the presence of a mark by the use of a fluorescent dye / pigment.

  The detector comprises a detector element housed behind a series of narrow band filters. The filter is set to maximize transmission at the same wavelength as the maximum emission from the emitter. Combination and static detector and filter combinations may be used. Alternatively, the filter may be moved across the detector and the emission measured in each bandpass region to determine that these compositions are present. This involves the use of a filter on a wheel that rotates in front of the detector, whose position is controlled and recorded by simple software.

  The dots were detected using a broad spectrum source to facilitate emission. Light emission from the existing quantum dots was then detected by a hand-held scanner.

  The software held in the scanner then converts the emission combination into a binary string, which is then further processed to provide a unique reference number for that particular combination.

  One embodiment of the present invention will allow a unique reference number to be subsequently searched against the data held on the scanner to determine the origin or ownership of the scanned item. .

  A further embodiment would allow that data, possibly of personal nature, to be kept on a central server accessible from a handheld scanner.

  The mathematical modeling on which the present invention is based requires tightly controlled measurements in a narrow spectral region. Since the detector system described above is set to determine a preset relative peak height, the concentrations of all compounds present are set so that the spectral output from each is the same. The detector may then be programmed to ignore any spectral output below a preset percentage of this output. Thus, the peak maximum may be obtained without complete baseline separation.

  Other detection systems are available and an electronically controlled Fabry-Perot interferometer may be used. These may be preset at the respective emission wavelengths of the emitters used, and the respective outputs are measured.

  The detector supplies data about the material present in a software package that is kept either in the detector itself or locally on the palmtop or laptop computer where the data is sent from the detector. Will do. Data from the detector is kept on the local computer and sent in a suitable format to a database that can contain all relevant information and provide owner details on the fly.

  Alternatively, perhaps for security, the data may be sent from a detector to a remote database using appropriate telephone or wireless technology, where details are found from the remote database Returned to operation. This is clearly a safer option, but it can take some time to get the needed information.

  Combined with quantum dot combination, mathematical modeling, and the detector system described, the ability to provide practically unlimited and instant traceability means that any object will be tracked. Meaning, this should be considered in the widest context involving life-like objects. Encapsulated quantum dots will be similarly detected by the above mechanism when injected as a tag into living tissue.

Claims (10)

  A security marker having a unique characteristic corresponding to a database entry and comprising at least one nanocrystalline quantum dot emitter, wherein the unique characteristic of the marker is unique to the at least one nanocrystalline quantum dot emitter A security marker that is a light emission profile.   The at least one nanocrystal quantum dot emitter includes ZnS, ZnSe, ZnTe, CdS, CdSe, CdTe, GaN, GaP, GaAs, GaSb, InP, InAs, InSb, AlS, AlP, AlSb, PbS, PbSe, Ge, The security marker of claim 1 selected from the group consisting of Si and ternary and quaternary mixtures thereof.   The security marker of claim 1 or 2, further comprising a support structure that supports the at least one nanocrystalline quantum dot emitter and facilitates attachment of the marker to an object to be tagged.   The security marker according to claim 3, wherein the support structure includes a polymer.   The security marker according to any one of claims 1 to 4, wherein the marker has a unique emission profile that is completely in the infrared region of the spectrum. A method of uniquely marking and identifying an object,
a) creating a unique marker having a unique emission profile from at least one nanocrystalline quantum dot emitter;
b) cross-referencing said unique marker with a database containing information about the object to be marked;
c) Providing the unique marker for the object, and uniquely marking and identifying the object.   The method of uniquely marking and identifying an object according to claim 6, further comprising exposing the marker to an electromagnetic radiation source and then detecting luminescence emitted from the marker.   8. A method for uniquely marking and identifying an object according to claim 7, wherein the electromagnetic radiation source is an ultraviolet lamp.   9. The object according to claim 7 or 8, further comprising the step of cross-referencing the detected luminescence against the database, thereby determining the stored information regarding the marker. A method of uniquely marking and identifying things.   The at least one filter is disposed between the marker and the detection means so as to maximize a specific emission wavelength in a situation where two or more emission wavelengths are emitted from the marker. A method for uniquely marking and identifying the object described in any one of the above.