MXPA00005188A - Self-targeting reader system for remote identification - Google Patents

Abstract

A method and apparatus for identifying articles (30) is disclosed. The method includes steps of:(a) providing a plurality of articles (30), each of the articles (30) having at least one portion (38) that includes a photonically active material;(b) for each article (30), illuminating the at least one portion (38) with light from a stimulus source (52);(c) identifying a location (50) of the at least one portion (38) by detecting an emission (56) from the photonically active material;(d) pointing an excitation source (44) at the identified location (50);and (e) illuminating the at least one portion (38) within the identified location (50) with light from the excitation source (44). A next step detects an information-encoded emission (62) from the photonically active material in response to the light from the excitation source (44). An optional step (g) sorts the articles (30) based on the detected emission (62).

Description

SELF-ORIENTATION READER SYSTEM FOR REMOTE IDENTIFICATION REFERRAL TO RELATED REQUESTS With this the priority is claimed under 35 U.S.C. § 119 (e) of co-pending provisional patent application No .: 60 / 066,837, filed on November 25, 1997, with the title "self-orienting reader system for remote identification", by William Goltsos. The description of this provisional patent application is incorporated herein by reference in its entirety.

FIELD OF THE INVENTION In general, this invention relates to methods based on optics and to "devices for identifying articles and, specifically, to methods and apparatus for identifying optically encoded articles.

BACKGROUND OF THE INVENTION In the patent of E.U.A. No. 5,448,582, a multi-phase gain means with an emission phase (as dye molecules) and a dispersion phase (such as T02) is described. A third matrix phase can also be provided in some modalities. Suitable materials for the matrix phase include solvents, glasses and polymers. It is shown that the gain means produces a collapse of spectral line amplitude similar to the laser above a certain pulse energy of pumping. The gain medium is described as being suitable for encoding objects with multiple wave amplitude codes, and as suitable for use with various substrate materials, including polymers and textiles. There is a type of industrial problems in which a large number of elements must be separated, identified, counted and / or selected. Current methods cover a broad spectrum of solutions. A solution applicable to macroscopic and visually identifiable elements encompasses a manual procedure in which workers select items in sequence from among many items in a group by identifying an intrinsic characteristic of an item or by a visually-readable coding system that is incorporated in the article. Once selected, the articles are directed, manually or via a transporter, to a location where articles that have a common attribute are stored or processed. In cases where inventory control is interesting, the selected items can be counted and tabulated manually by some direct action by a worker or automatically when the selected item goes through a counting device. For example, in the commercial laundry industry, the rental items are returned in unselected groups and washed. The workers select simple garments, place the garments on a hook and then on a conveyor that deposits the garments in one of several fastening areas. An appropriate area of the various fastening areas is chosen for an individual garment based on a code that can be read by the individual and applied to the garment, usually inside the collar, which identifies some common attribute for all garments in the garment. a fastening location. Almost always, the attributes include, for example, a day of the week, a route number or the name of an end user. Similarly, in the white supply industry, whites are delivered to a volume laundry and unselected groups. Workers select the individual targets of a group and identify each item by a characteristic of the group, for example, color, shape and / or size. The selected and identified article is then directed to an appropriate area to be washed by a specific washing formulation. As can be seen, the labor force to identify, count, select and tabulate items (for example, white and / or clothing) has numerous limitations. A limitation on processing performance is of particular interest in this invention. In some laundries approximately 100, 000 or more individual items must be processed in a single eight-hour work shift. Since workers are required to perform multiple tasks on each item (for example, identify, count and select each item) a conventional worker can only process a limited number of items in an eight-hour shift. In addition, the burden of performing multiple tasks manually on each item also causes lack of accuracy in identification, selection and counting procedures. 5 In an effort to eliminate or at least minimize the limitations in the manual procedures already described, automated solutions have been sought. Conventional automated procedures have been developed to improve accuracy and minimize the labor required to identify, count and select individual elements. For example, to achieve these results, laundries have used bar code labels (almost always symbology 2 of 5 interspersed) and radiofrequency (RF) chip; however, these techniques have limited longevity, in particular because the labels and the chips are exposed to the harsh environment of industrial laundries. In addition, a solution in which use bar code labels have the problem of taking up a lot of time and, sometimes, it is very difficult to place a label on a large item when the label is not properly aligned, ie in a field of view of the reading device of barcodes. Although RF chips do not present the alignment problem, they do have certain difficulties due to its unproven longevity and high costs. In the patent application of E.U.A. Copending No.: 08 / 842,716, now patent of E.U.A. No. 5,881, 886, an alternative method for identifying articles is described. In this alternative method, photonically active materials, such as patches, labels and yarns, can be attached to garments and targets. A suitable selection of materials having, for example, a narrow-band laser action emission that can be uniquely distinguished is used to form optically identifiable codes. The codes allow the identification of clothing, targets and other items. In one embodiment, two or more fibers or yarns, hereinafter referred to as LaserThread ™, present detectable emissions that are incorporated into garments, blankets and other articles to optically encode information in these articles. For example, LaserThread ™ can be incorporated into garment labels to uniquely identify a rental garment, or characteristics thereof, during processing. Similarly, LaserThread ™ can be sewn on the edges of the targets, for example, on the hem of a tablecloth, to uniquely identify the targets and / or characteristics thereof. As specified in the patent application of E.U.A. As already mentioned, LaserThread ™ produces laser-like emissions when excited by, for example, a laser that has specific wavelength, pulse energy and pulse duration. In general, the required excitation laser has a wavelength in the red to blue region of the visible spectrum and can provide densities of radiant energy in the order of, for example, about 10 millijoules per square centimeter when a pulse of about 10 nanoseconds to the LaserThread ™. Exemplary excitation sources include, for example, dual frequency Nd: YAG, Q switched and pumped lasers by magnesium lamp; Nd: YAG lasers of double frequency, Q switched and pumped by diodes; and sources derived from other nonlinear products related to Nd: YAG lasers mainly or other laser crystals. However, the excitation sources available in the market suitable for exciting photonically active materials, such as the LaserThread ™, can be expensive. Therefore, it can be appreciated that an identification system design that maximizes the excitation pulse energy efficiency is important. Furthermore, it can be appreciated that the excitation pulse energy efficiency can be maximized by controlling too much the location and orientation of the photonically active materials incorporated in an article to be evaluated. If the tight controls are maintained then a narrow excitation beam of fixed orientation can affect the photonically active materials incorporated in the article to be evaluated with a predictable degree of safety. Alternatively, if the controls of the location and orientation of the photonically active materials are relaxed, then an orientation system is needed to locate the photonically active materials incorporated in the articles, so that an excitation beam can be directed to excite the materials. . As already mentioned, the ability to control in an adjusted manner the orientation of photonically active materials incorporated in an article under evaluation in particular presents some problems during various processing operations. For example, a region of the article containing the material may become fouled or otherwise clogged and, therefore, irradiation of the photonically active materials would be avoided. Accordingly, the inventor has noted that it is convenient to employ an orientation system and an identification system with procedures to optionally separate, identify, count and select items.

OBJECTIVES AND ADVANTAGES OF THE INVENTION The first object and advantage of this invention is to provide methods and an apparatus for identifying and optionally selecting items that overcome the aforementioned and other problems. Another object and advantage of this invention is to provide improved methods and apparatus for identifying articles based on a detected emission from an article. Another object and advantage of this invention is to provide methods and an apparatus for identifying articles that include an acquisition of luminous materials incorporated within or on a surface of an article, a directed excitation of the luminous materials, and a detection of an emission of the luminous materials to identify and (optionally) select the article. Other objects and advantages of this invention will become apparent from the consideration of the drawings and the following description.

BRIEF DESCRIPTION OF THE INVENTION The aforementioned and other problems are overcome and the objects and advantages are realized by methods and an apparatus in accordance with embodiments of this invention. A method of the present invention includes the steps of: a) providing a plurality of items to be identified, each article having at least one portion that includes a photonically active material; b) for each article, illuminate at least one portion with light from a stimulus source; c) identifying a location of at least one portion by detecting an emission from the photonically active material; d) point a source of excitation at the identified location; e) illuminating at least a portion at the location identified with light from the excitation source; and f) detecting a secondary or similar emission to the narrow band laser from the photonically active material in response to light from the excitation source. An optional step can also be made to select the articles based on the secondary emission or similar to the detected laser. The secondary or laser-like emission detected carries information in the form of an optical code to identify at least one characteristic of the article during processing operations. In accordance with the present invention, an apparatus for identifying articles includes a device for carrying each article through a field of view of the apparatus. A stimulus source generates light that illuminates at least a portion of the item in the field of vision. In the present invention, at least one portion includes a photonically active material. In response to light from the stimulus source, the photonically active material emits a fluorescent emission. A device identifies a location of at least one portion by detecting the emission of the photonically active material. An excitation source generates light that exceeds a threshold fluence. A pointing device directs the excitation source at the identified location, so that the light from the excitation source illuminates at least a portion at the identified location. In response to light from the excitation source, the photonically active material produces a secondary or similar emission to the narrow band laser. An optical detector detects the secondary emission or similar to the narrow band laser from the photonically active material. The secondary or laser-like emission detected carries an optical code to identify at least one feature of the article. Then at least one feature can be used to identify and optionally select the items.

BRIEF DESCRIPTION OF THE DRAWINGS The aforementioned characteristics and other features of the invention become more apparent in the following detailed description of the invention when read together with the accompanying drawings, wherein: Figure 1 illustrates an excitation source constructed in accordance with the present invention; Figure 2 is a top view of a beam signaling system in accordance with this invention; Figure 3 is a side view of the beam signaling system of Figure 2; Figures 4 and 5 are useful to explain a calibration technique in accordance with this invention; Figure 6 is a diagram of the related calibration equipment used to make the optical axes of the acquisition and the pointing systems coincide; Figure 7A is an elevational and elevational view of a cylindrical laser microaction structure for incorporation into an article in accordance with the present invention; Figure 7B is an enlarged cross-sectional view of the cylindrical laser microaction structure of Figure 7A; Figure 8 is a diagram of an exemplary identification system operating in accordance with the present invention; and Figure 9 is a more detailed block diagram of a self-targeting reader of the identification system illustrated in Figure 8.

DETAILED DESCRIPTION OF THE INVENTION The description of the patent of E.U.A. No. 5,448,582, issued September 5, 1995, entitled "Optical Sources Having a Strongly Scattering Gain Medium Providing Laser-Like Action," by Nabil M. Lawandy is hereby incorporated by reference in its entirety. The invention can employ a laser-like emission, such as that having a spectral and temporal collapsed emission or a secondary emission. A secondary emission can be any optical emission from a photonically active material that results directly from the absorption of energy from an excitation source. Secondary emissions, as used herein, may encompass fluorescence and phosphorescence. Therefore, it should be noted at the outset that the teachings of this invention can be used to identify articles that have been encoded with materials that do not exhibit laser-like action, such as phosphor particles, dyes (without dispersants), and semiconductor materials. A particularly suitable type of semiconductor materials is manufactured to form quantum source structures that emit light at wavelengths that can be tuned by manufacturing parameters. As such, in one aspect, this invention employs an optical gain means that has the ability to exhibit laser-like activity or other emissions from the medium upon excitation by an excitation energy source, as described in the U.S.A. 5,448,582 mentioned above. The optical gain means may consist of a matrix phase, for example a polymer or substrate, which is substantially transparent at wavelengths of interest; and a phase of emission and amplification of electromagnetic radiation, for example a chromic dye or a phosphor. In some embodiments, the optical gain means also includes a high scattering phase index of refractive contrast electromagnetic radiation, such as particles of an oxide and / or scattering centers in the matrix phase. The teaching of this invention can employ a colorant or some other material that has the ability to emit light, perhaps in combination with particles or dispersion sites, to exhibit electro-optical properties consistent with laser action, ie, a similar emission to the laser that presents a collapse of spectral line amplitude and a temporary collapse in an input pumping energy above the threshold level. In another aspect, as already indicated, the invention employs a secondary emission that can be any optical emission from a photonically active material that results directly from the absorption of energy from an excitation source. Secondary emissions may include fluorescent and phosphorescent emissions. The invention can be applied to the construction of articles, for example, garments or blankets, wherein, in addition, the article includes at least a portion containing the gain means for providing an emission of narrow band optical radiation (e.g., about 3 nm) in response to the pumping energy above a threshold fluence. The emission of narrow band optical radiation allows the identification (and possible selection) of the article. An elongated filament structure, such as a wire, for example, LaserThread ™, includes material for emission and amplification of electromagnetic radiation. The material of emission and amplification of electromagnetic radiation, perhaps in conjunction with dispersers, provides emission similar to the laser, as already described. In one embodiment of the invention, one or more elongated filament structures, which for example have a diameter of approximately 5-50 μm, are placed in or within at least one region of a garment or article of blanks. A plurality of emission wavelengths may be provided, whereby the wavelength encodes the article of clothing or article of blanks. In accordance with another aspect of the present invention, a structure that employs one or more optical gain medium films, deposited around a core provides the laser-like emission, as already described. The structure can have various geometric shapes, including globules, discs and spheres. The globules, discs and spheres are incorporated into an article to allow identification and optional selection of the article during processing operations. For example, the co-pending and commonly assigned provisional patent application No. 60 / 086,126, filed May 2, 1998, under the title of "Cilindrical Micro-Lasing Beads For Combinatorial Chemistry and Other Applications", by Nabil M. Lawandi, describes a cylindrical laser microaction structure suitable for practicing this aspect of the present invention. The description of this provisional patent application is hereby incorporated by reference in its entirety. In FIG. 7A there is an enlarged elevated view of a cylindrical laser microaction structure 20. The cylindrical laser microaction structure 20 includes cylindrical dielectric sheets that are 10 equivalent to a closed two-dimensional plate waveguide, and supports a resonant mode . Modes with Q values exceeding 106 are possible with active layer thicknesses of approximately 1-2 μm and diameters (D) of approximately 5-50 μm. Figure 7B illustrates an increasing cross-sectional view of the cylindrical laser microaction structure 20 of Figure 7A. The region of the core 22 is surrounded by a layer or region of gain medium 24 and an isolation layer or region 26. The layer of the gain medium 24 has a higher refractive index than the region of the core 22 and the insulation layer 26. A plurality of layers of the gain medium and a plurality of insulation layers surround the region of the core 22. The core region 22 can be metal, polymeric or dispersion. The gain medium layer 24 is preferably one among a plurality of optical gain medium films that are positioned around the core 22 to provide a plurality of characteristic emission wavelengths. As already mentioned with several exemplary embodiments, an optical gain means with the ability to produce a secondary or laser-like emission can be used to identify articles. Said articles may be, but are not limited to, whites or garments of various types of textiles in general. As described below, an aspect of the present invention is to provide an identification (and possible selection) system that includes an acquisition system, a pointing system, an excitation system and a detection system. In accordance with this aspect of the present invention, the identification system allows the photonically active materials placed in an article under evaluation to be localized (ie acquired), that a source of excitation is signaled in the materials purchased, that an emission of excitation is directed on them, and that an optical response (emission similar to laser or secondary emission) is detected to the emission of excitation coming from the materials. In this way, a system of "search, pointing, firing and detection" allows the identification of items during processing operations. It should be noted that having identified an article, you may want to select or subsequently segregate the identified article from among other articles. In this case, any suitable type of apparatus to set aside, manipulate or select may be coupled to the identification system to affect the subsequent processing of identified (or unidentified) items. However, the practice of this invention does not require making the selection, or that the identified objects are segregated in any way from each other or between other objects. Figures 8 and 9 illustrate an exemplary embodiment of a self-targeting reader system for remote article identification, ie the aforementioned "search, signaling, triggering and detecting" system. As illustrated in Figure 8, the articles 30, such as for example garments, blankets, textiles and other coded materials, are identified when they pass through an acquisition field 32 of a remote identification device 34. In a embodiment of this invention, various items 30 can automatically pass through the acquisition field 32, in the direction indicated by arrow "A", by means of a conveyor, such as a moving rail or conveyor belt 36. In accordance with the present invention, articles 30 include at least one region 38 containing photonically active materials . As already mentioned, the photonically active materials allow an optical coding of the articles 30 for purposes of, for example, identification and optional selection of the articles 30 during processing operations. For example, at least one region 38 can be sewn, pasted, or otherwise fixed or joined to a label for article 30. As can be seen in the various embodiments described above, optical coding and identification of the Articles 30 can be made by detecting a secondary or similar emission to the single laser from at least one region 38 in response to an excitation. Figure 9 shows a schematic diagram of the self-orienting reader system of Figure 8. In Figure 9, four functional aspects of the reader system are particularly emphasized. These four functional aspects include devices for carrying out the acquisition of orientation 40, signaling 42, excitation 44 and reception or detection 46, that is, the "search, pointing, triggering and detecting" properties of the self-orienting reader system 34. The acquisition of the objective uses a luminous property of the photonically active material attached to the article 30 under evaluation to locate a brighter or stronger emitting area of the article 30. That is, an area 50 of article 30 which, in response to an excitation, produces a luminous or fluorescent emission at one or more specific wavelength scales. In Figure 9, a suitable stimulus source 52 may employ a lens 54 or some other means to preferably produce a divergent ray pattern 53 that illuminates the acquisition field of reader system 34. As a result, the photonically active material attached to the Article 30 passing through the field is excited by the emission from the stimulus source 52. As already mentioned, in response to the excitation, the photonically active material produces the luminous or fluorescent emission at a specific wavelength scale. As can be seen, the appropriate stimulus sources 52 are selected in accordance with the application and properties of the fluorescent materials incorporated in the articles under evaluation. It is desirable that the beam 53 be of sufficient amplitude to ensure detection of the photonically active material for whatever orientation it may assume. Suitable examples of the stimulus source 52 may include, for example, X-ray sources, xenon magnesium lamps, fluorescent lamps, incandescent lamps and a wide diverging laser beam. In one embodiment, the appropriate stimulus source 52 can be produced by modifying the excitation device 44. Referring to FIG. 1, during an excitation mode, the emission from the excitation laser source 1 propagates along an excitation mode. ray trajectory 7 towards the signaling system. During the acquisition mode, a stimulus source is created from the excitation by redirecting the emission of the excitation source along the ray path 8 by introducing a movable mirror 5. An actuator 2 causes the mirror 5 interrupts the beam path 7, which has a rotation arrow 3 to which the mirror 5 is supported by an activation arm 4. The actuator 2 can be a solenoid, a galvanometer, or any other device that can making the mirror 5 be placed in and out of the beam path 7, preferably by an electrical command of the reader's control electronics. After the beam deviates from the beam path 8, it is directed to the inlet surface 11 of a 10 mode mixing glass. Depending on the specific design needs, the beam can be directed on the surface of the crystal 11 by the reflection of a mirror 6, and may require focusing through a lens 9 to cause the entire ray to enter the surface of the crystal 11. The mixing glass is 10 is a light tube that preferably has a transverse shape equal to the shape of the vision acquisition field (ie, if the field of view is designed to be square, then the cross section of the crystal is also square). In the preferred embodiment, all sides of the crystal are polished, so the light propagating inside the crystal is reflected in the incidence with one side by total internal reflection. As an alternative, the sides of the crystal 10 could be made to have a high reflection coefficient by coating the sides with a metal or dielectric coating. The inlet surface 11 is ground using a micrograin so that the light entering the entrance surface is dispersed in random directions within the glass 10. This mixing of the wave front causes the light to uniformly fill the volume of the glass. crystal 10 after the multiple internal reflections of the sides of the crystal. Upon reaching the output surface of the crystal 10, the distribution of light is uniform on the output surface and has the shape of the cross section of the crystal. Likewise, the light leaves the crystal 10 through a wide and random scale of angles, whose maximum is determined by the refractive index of the crystal and the surrounding medium (usually air). The light emerging from the crystal 10 is collected and imaged by a lens 12 in an orientation area of the acquisition system 14. The image-producing lens 12 is chosen to cause the rays in image 13 of the crystal 10 to substantially fill the orientation area. The normal mode of operation of the reader system is as follows.

First, the mirror 5 is placed in the ray path 8. When an article is detected in the field of vision acquisition, the excitation source is activated by causing a uniform illumination to surround the orientation area and therefore the article. Uniform illumination causes the materials encoded in the article to fluoresce and be detected by the acquisition chamber. The mirror 5 is removed from the beam path 8, and instructions are given to the signaling system to point in the direction of the brightest detected fluorescence. When the article is detected in the oriented area of the signaling system, once again, the excitation source is activated to cause the narrowed excitation beam to strike the coded material. After detecting and analyzing the coded emission, the mirror 5 is returned to the beam path 8 and the cycle is ready to be repeated. In general, it should be understood that an appropriate stimulus source 52 is an electromagnetic radiating source whose emission is absorbed by the photonically active material, and which has sufficient photon energy to induce a detectable fluorescence in the photonically active material. For example, in a modality in which the previously identified LaserThread ™ is incorporated in article 30 under evaluation, a xenon magnesium lamp having a spectrally narrow emission through a filter is an adequate source of stimulus 52, since it can Make the LaserThread ™ fluoresce by absorbing the visible radiation of the xenon magnesium lamp. In another embodiment where article 30 is emitting by itself in a location where the photonically active material is incorporated, a source of stimulus 52 is not required. Such emitting articles by themselves include, for example, bioluminescent and chemiluminescent articles. Luminous or fluorescent emissions from the photonically active material, induced or intrinsic, are detected by an image producing electronic camera system 56 of the orientation acquisition system 40. Preferably, a field of view of the camera system 56 coincides with or is less than the divergent ray pattern 53 of the stimulus source 52. In essence, the field of view 55 of the camera system 56 defines the acquisition field 32 of the voter system 34. In one embodiment, the fluorescent emissions of the photonically active material they pass through a filter that substantially passes the fluorescent emission, but which attenuates the scattered stimulus emissions very widespread or specularly reflected from article 30. With the location of appropriate filters, ie filters having non-coincident passage bands, in a trajectory of stimulus source 52 and chamber 56, the primary emissions of The stimulus source 52, after influencing article 30, is not detected by the camera 56. The electronic signals from the imaging camera system 56 can be analyzed by a computer or dedicated image processing electronics 41 for determining the location, in the field of view 55, of the strongest emitting area 50 of article 30. For this purpose, conventional image acquisition and processing software may be employed. It should be appreciated that in applications where only a single fluorescent section of the article 30 may be present simultaneously in the acquisition field 32, other image detectors such as position detectors may be used in place of the imaging camera system 56. The information specifying the location in the field of view of the strongest emitting area 50 of article 30 is passed from the guidance acquisition system 40, ie the camera system 56 or the processing electronics 41, to a signaling system Lightning 42. The lightning signaling system 42 processes the location information and, in response thereto, aligns or directs emissions 60 from the exciting device 44 to impact the article 30 substantially in the strongest emitting area 50. It should be noted that, in accordance with the present invention, the signaling system 42 includes a lightning direction device 58 which responds to location information (e.g., electronic control signals) of the orientation acquisition system 40. It should also be appreciated that the signaling system 42 may include acousto-optic beam detectors, mirrors rotating polygonal, translators of lenses (set of microlenses), scanners with resonant galvanometers and holographic scanners, or any combination thereof. In one embodiment of the signaling system 42, a two-axis beam direction signaling system consists of two scanners with non-resonant galvanometers, each with a mirror attached to the scanner's arrow. A scrutineer causes the deviation of the beam along an axis and redirects the emissions from an excitation source in the second mirror of the scrutineer. A rotation axis of the second scanner has an orthogonal orientation with respect to the first axis of the scanner, so that the excitation emission returns to the article and can be scrutinized in two independent axes to cover substantially the entire acquisition field of the scanning system. acquisition 40. The reflective characteristics of the mirror are specified to allow a greater performance for the excitation system while also allowing greater performance for the secondary emission or emission of laser action of the photonically active material to article 30. Preferably, the mirrors they have a high threshold of energy-density damage at the excitation wavelength. The signaling system 42 also includes a diplexer 59 for combining the emissions 60 of the propagation of the excitation source 44 to the article 30 with a secondary emission or a laser-like emission 62 from the photonic material that is propagating to the device. reception 46. Figure 2 is a top view of the signaling system and Figure 3 is a side view. The beam path A originates from the diplexer 59 and includes the excitation beam which counterpropagates the light received from the coded article. The ray A is reflected from the first mirror M1 to form the ray B, or if the mirror M1 rotates, to form the ray C. The mirror M1 is placed on the arrow M1 of the first galvanometer GV1. The axis of the arrow S1 is almost always positioned orthogonal to the beam path A. GV1 causes the mirror M1 to rotate in response to electrical signals from the reader's control electronics. The beam B or C is reflected from the second mirror M2 to form the ray D, or if the mirror M2 rotates, to form the beam E. The mirror M2 is placed on the arrow S2 of the second galvanometer GV2, where the axis of S2 has an orthogonal orientation with respect to S1, and almost always lies in a plane containing the ray A. GV2 causes the mirror M2 to rotate in response to the electrical signals coming from the reader's control electronics. The mirror M1 causes beam A to move along a line projected in the plane of the orientation area that is parallel to the original beam path. The mirror M2 causes the ray A to move in a line projected in the plane of the orientation area that is orthogonal to the original ray, and almost always parallel to the ray B. In this way, the activation of the mirrors M1 and M2 make the ray A is diverted to an instruction point in the TA orientation area. The diplexer 59 can be seen as several conventional devices that use any of the three properties of photons to allow the collinear counterpropagation of a light beam. The three properties are polarization, wavelength and moment. As a result, the diplexer 59 can be modalized as a polarization beam separator (when polarization is employed), a dichroic mirror (when the wavelength is used) and a non-reciprocal free space element referred to in the art as a circulator ( when the moment is used). Another suitable embodiment is a partial reflection mirror, also known as a lightning separator, which can be used when the losses associated with this device can be tolerated in the overall system design. An element 66 of the receiving system 46 is a functional equivalent of the diplexer 59, but almost always, it is configured as another of the three devices described above. In one embodiment, for example, diplexer 59 is a dichroic mirror and element 66 is a polarization beam separator. In effect, the element 66 serves to add an output of a coherent or calibration source 64 to the collinear beam passing from the signaling device 42 to the receiving device 46. The addition of the output of the coherent source 64 is effected during a mode of calibration operation of the reading system 34. During the calibration operation mode, the output of the coherent source 64 is added to the collinear beam to allow the calibration of the directed position determined by the signaling system 42 to the strongest emission area 50 detected by the acquisition device 40. In one embodiment, the coherent source 64 consists of, for example, a laser diode, a helium-neon laser, or other suitable source that emits radiation detectable by the camera system 56 of the acquisition device 40. In a preferred calibration procedure, a flat lens is placed in the field of view 55 of the hard camera system 56 a calibration operation, so that a portion of light from the coherent source 64 which propagates collinearly with the light from the excitation source 60 and the received light 62 is dispersed from the planar orientation in the camera system 56. A data table is generated and stored in the computer or dedicated image processing electronics 41 of the acquisition system 40. The entries in the data table link a single detected strongest emission area 50 of item 30 and a position directed only of the signaling system 42. During a normal mode of operation of the reading system 34, ie when the calibration mode and, therefore, the coherent source 64 is turned off, the data table is used to aid in the determination of an appropriate position for the signaling system 42 to direct the emission of excitation source 60. That is, with the comparison of a position of an emission area m s detected strong 50 in the acquisition field for corresponding entries in the data table determines an associated directed position for the signaling system 42. Regarding the calibration in greater detail, Figure 4 shows a more detailed side view of the invention . In this figure the acquisition system AS (and associated vision field FOV1) and the PS signaling system (with its associated field of vision FOV2) appear separated to see them clearly. In the preferred embodiment, it is desired that the two fields of vision be overlapped as much as possible to minimize orientation errors arising from unwanted movement of the article on the conveyor, which may occur during the time between acquisition and delivery. excitement. The detected position of the brightest fluorescence by the image camera of the acquisition system corresponds to two orthogonal angles in the field of view of the camera. If an imaginary line is drawn to connect the camera and the fluorescence area, then this line can be described by the angles, if it is formed with respect to the central axis of the camera. One of these angles A1 is in a plane that contains the velocity vector of the article and the camera, that is, in the plane of the figure. The other angle is in a plane orthogonal to the first, and contains a line that crosses the width of the conveyor and the camera, that is, a vertical plane that projects in a perpendicular position outside the page. Similar angles (for example, A2) can be drawn from the position of the article in the field of view of the pointing system. If these angles are not identical in the fields of vision (ie A1 = A2), then parallax errors could cause the PS signaling system to point to the wrong area. Therefore, preserving these angles is an important aspect of the invention. This is especially important because items on the conveyor do not necessarily remain in the plane of the conveyor belt. In fact, they are more likely to have a three-dimensional characteristic after having formed a stack. Figure 5 shows how parallax can cause pointing errors if the angles in the fields of vision are not preserved. In Figure 5, the acquisition system AS locates the area of highest fluorescence F and records this area on a map to a point P in the plane of the orientation area TA. For flat items, point F matches point TA. The signaling system of this mode does not have a scrutiny mirror to indicate the emission of excitation in the plane of the figure. Instead, this system expects the item to move under the pointing system until the TP orientation point is directly below it. Then, while the orientation point TP is identical to the point in the plane of the orientation area TA, the emission loses the desired orientation point DTP in the article. This is because the signaling system does not retain the orientation angle A1 measured by the acquisition system, and a parallax error has occurred. However, in a modality where articles are known to be on the conveyor, this type of system configuration points to the desired point with the benefit of using a less scrutinizing mirror. It should then be clear that you must perform a calibration procedure so that the acquisition angle A1 agrees with the pointing angle A2 in Figure 4, since the angle corresponding to the area of highest fluorescence is used to order the pointing mirrors of the signaling system that reproduces the pointing angles accurately. The calibration procedure employs an additional apparatus during the calibration procedure which causes the optical axes of the acquisition system and signaling system to be coincident. Figure 6A shows a preferred embodiment. The calibration apparatus of FIG. 6 includes a partial reflection beam spacer BS (also known as a plastic film beam spacer), a mirror M, and a fixed part for holding the acquisition chamber 56 and the scanning system. PS marking in precise alignment with mirror M and beam separator BS. The apparatus works by making the axis of rotation of the PS signaling system accurately match the pupil of the lens of the camera L. With this alignment, an arbitrary ray R1 coming from the signaling system propagates to the orientation area as an R2 beam. , it is reflected again in the orientation area by path R2 and in chamber 56 as ray R3. The beam R3 has the same angle with respect to the optical axis of the camera 56 as the beam R1 has with respect to the optical axis of the signaling system. The ray R1 is derived from the coherent source in the receiver (calibration source 64 in Figure 9). During the calibration procedure, a command signal is supplied to the signaling mirrors to signal the coherent source in a direction of, for example, ray R1, and the light of the coherent source scattered from the orientation area is detected by the camera 56 as lightning R3. Next there is a map record of the command signal for the pointing mirrors and a position detected in the acquisition camera 56. A table containing all possible combinations of command signals for the mirrors is constructed., and the corresponding detected position in the chamber 56. After completing this calibration procedure, the calibration table is used in reverse, so that a position detected in the chamber 56 can now be used to define a single command signal for the mirrors, that reproduce with precision the same angle of field. Table 1 shows a subset of an exemplary calibration table constructed during the calibration procedure. The values Vx and Vy are voltages sent to the signaling mirrors, and the entries in the table at the intersection of voltage values are the pixel values x and y of the camera that detected the light from the reflected source. Table 2 is derived from Table 1, and is used during the normal mode of operation. When a bright fluorescent area is detected, the pixel values x and y for the pixel that detected the fluorescence are used to determine the command voltages Vx and Vy to the pointing mirrors.

TABLE 1 TABLE 2 As already indicated, the excitation of the photonically active material, for example, LaserThread ™, is provided by the excitation source 44. The specifications for suitable excitation sources 44, therefore, are determined by the requirements of the photonically active material of the Article 30 of interest. For example, LaserThreads ™ are excited to laserize when exposed to the output of a laser that has specific characteristics of wavelength, pulse energy and pulse duration. In general, the required excitation laser has a wavelength in the red to blue region of the visible spectrum and can provide densities of radiant energy in the order of, for example, about 10 millijoules per square centimeter when a pulse is directed 10 nanoseconds in the LaserThread ™. Exemplary excitation sources include, for example, dual frequency Nd: YAG lasers, Q switched and pumped by magnesium lamp; Nd: YAG lasers of double frequency, Q switched and pumped by diodes; and sources derived from other non-linear devices that are mainly related to Nd: YAG lasers or other laser crystals. To increase the tolerance of the system to signal errors (i.e. direction error of the excitation source 44) and variations in the movement of the article through the field of view 55 of the acquisition system 40, the excitation beam 60 preferably it is divergent, so that it illuminates a point in the article that is larger than the resolution of images and pointing of the reader. In accordance with one embodiment of this invention, the photonically active material is excited by the excitation source 44 to fluoresce and provide optical coding, and the source 44 may be different from a laser source. In this case, the source is selected to produce in the detector a signal raised to a noise ratio signal that is suitable for spectral analysis. For example, the source could comprise a spectrally filtered and substantially collimated xenon magnesium lamp. As already mentioned, the signaling system 42 picks up and directs the secondary or laser action emission 62 of the photonically active material in the receiving system 46 by the beam direction device 58 and the diplexer 59. In one embodiment, the system reception 46 includes a dispersion element to analyze the received emission by spectrum. For example, the receiving system 46 can couple received emissions in an optical fiber that is coupled to a graticule spectrometer and multi-channel detector element, such as a CCD assembly. As an alternative, the receiving system 46 includes an image spectrometer to perform a spectral analysis of emissions on an axis, and to create spatial images of the emissions by an orthogonal axis. A dedicated computer or electronic processor can analyze the spectral and / or spatial signature of the emissions to produce an indication of an identity of an article under evaluation. As can be appreciated, a finite amount of time is required to acquire a data field from the camera system 56 and to process that data into the acquisition system 40 to locate a brighter fluorescent area 50 of article 30. During this time, the Article 30 may be moving through the acquisition field 32 of the reading system 34. Unless the displacement of the article as a result of this movement responds to the signaling system 42, it will direct the emission of the excitation source 44 to an incorrect location, it is say, a location where the brightest fluorescent area 50 of Article 30 was already detected. Therefore, it is within the scope of the present invention to explain the displacement of article 30 during the examination. For example, in one embodiment the acquisition system 40 is physically separated from the other systems of the reading system 34 by a distance at least the length necessary to respond to the acquisition and processing time of the location of the brightest fluorescent area., plus any response time necessary for the mechanical elements of the signaling system 42 to direct the emission 60 from the excitation source 44. As can be appreciated, this period will vary by specific instrumentation factors, such as, for example, the speed of the conveyor device 36 which moves the article 30 through the acquisition field 32. In the exemplary embodiment, the acquisition and signaling systems 42 are activated by a first sensor located to detect the movement of the article by the acquisition field 32, while the Excitation systems 44 and reception 46 are activated by a second sensor. In accord with this embodiment of the present invention, the location of the first and second sensors are adjusted to minimize and substantially eliminate errors resulting from the movement of the article 30. In one embodiment, the reading system 34 identifies a plurality of articles in a stationary acquisition field. In this embodiment, articles that are smaller in size than the acquisition field and can be randomly dispersed in the acquisition field or, alternatively, separated in order, so that adjacent articles are not in contact. For example, an orderly separation of the articles could be achieved using a segmented tray. All items in the acquisition field can be illuminated with a single pulse from a stimulus source 52. The only pulse of sufficient energy to excite fluorescence in all articles in the acquisition field. It can be seen, as already mentioned, that the articles can also be fluorescent by themselves. In this embodiment, an orientation acquisition algorithm identifies all detectable light emissions from articles that exceed a predetermined threshold brightness value. The orientation locations detected by the acquisition system can then be passed in series to the signaling, excitation and reception systems to identify and optionally allow selection of the items in the acquisition field. In a preferred embodiment, the signaling system directs emissions of the excitation system and the response of the photonically active material to the receiving system. However, one skilled in the art may appreciate that other embodiments are also within the scope of this invention. For example, one mode can only have the excitation system addressed through the signaling system, while the receiving system sees the entire acquisition field separately to pick up the response of the photonically active material, or vice versa. In another modality, the acquisition, excitation and reception systems can be directed through the signaling system.

Although they are described in the context of the preferred embodiments, it should be noted that one skilled in the art can think of several modifications to these teachings. For example, the teachings of this invention are not intended to be limited to the identification and optional selection of any specific type of article. As such, those skilled in the art will recognize that the teachings of this invention can be employed in a large number of identification applications. It may be desirable to use the reader system of this invention with a wide range of coded materials, such that an excitation source wavelength is not sufficient to provide adequate excitation for all materials. In this case, the excitation source could be adapted to include multiple wavelengths. In one embodiment, a second wavelength is generated from the first wavelength through a nonlinear optical procedure (e.g., through a shift of stokios), and the two wavelengths are made to be collinear using one of the diplexer devices described above. The two rays are preferably collinear to pass through the signaling system. In addition, it may be desirable to detect article properties other than the encoded material. For example, it may be useful to determine the color of the article in which the coded material is applied. In this embodiment, other properties of the article could be determined by incorporating other suitable detectors into the reader's receiver, in addition to the spectrometer of the preferred embodiment. The optical axis of this additional detector (s) can be placed in colinear position with the optical axis of the receiver by means of a diplexer element. It may be desirable to make the field of vision of the additional detector (s) wider than the field of view of the spectrometer, so that these other properties of the article are measured at locations close to the location of the encoded material. The reading device of the preferred embodiment of this invention has capabilities to orient itself in a two-dimensional field of view (by means of an area camera), and to excite / detect targets in a two-dimensional field of view (by means of a pointing system). two-dimensional). However, other modalities can be provided considering acquisition capacities restricted to one dimension (by means of an online scanning camera), or detection of a point (single element, detector without images), and considering the capabilities of the signaling system, restricted to a dimension (a single axis scanner), or point excitation / spectral detection (without scrutinizer). Various swaps are also possible. A reader system of the above type (a single axis scan) is applicable in particular when the articles have the coded material applied at a location known in the article through the dimension parallel to the direction of movement through the conveyor. In this case, the movement of the conveyor can be used to replace the scrutinizer function. This configuration is subject to parallax errors (as shown in Figure 5) and has greater applicability when the articles are in the plane of the conveyor. This scope also employs a stimulus source that has the ability to provide a continuous result or at least one repetition rate that, together with the velocity of the conveyor, provides adequate spatial resolution through the direction of motion. A reader system of the above type (without scrutiny) may be applicable when the location of the material encoded in the article is known along both axes of the article. Similar to the previous case, the reader system uses the movement of the article by the conveyor to provide the scrutiny function. Another embodiment of the invention applies to a case where the code in the article is distributed in several separate locations, and where the separation distance is greater than the spatial resolution of the signaling system. For example, the optical code may require a plurality of wavelengths and, consequently, a plurality of coding materials that can not be easily placed. In this case, the acquisition system identifies the locations in the article of each of the component materials. The reader system then signals, excites and sequentially detects the optical wavelength of each material in the article, subsequently, "constructs" the code by an appropriate combination or concatenation of the individual detected wavelengths. Therefore, it can be appreciated that although the invention has been shown and described in particular with respect to the preferred embodiments thereof, those skilled in the art will understand that changes can be made to the form and details herein without departing from the scope and scope of the invention. spirit of invention

Claims (41)

NOVELTY OF THE INVENTION CLAIMS

1. - A method for identifying articles, comprising the steps of: providing a plurality of articles, each article having at least one portion that includes a photonically active material; for each article, illuminate at least a portion with light from a stimulus source; identifying a location of at least a portion that includes the photonically active material by detecting an emission of the photonically active material; point to a source of excitation at the identified location; illuminate at least a portion at the location identified with light from the excitation source; and detecting a coded emission of identification of the photonically active material in response to the light coming from the excitation source.

2. A method according to claim 1, further characterized in that the photonically active material consists of wires comprising a substrate material and a material for emission and amplification of electromagnetic radiation to produce a laser-like emission.

3. A method according to claim 2, further characterized in that the yarns are sewn to the article.

4. A method according to claim 2, further characterized in that a patch consists of threads, and wherein the patch is attached to the article.

5. A method according to claim 1, further characterized in that the photonically active material consists of spherical structures to produce a laser-like emission.

6. A method according to claim 1, further characterized in that the stimulus source consists of an electromagnetic source, whose emission is absorbed by the photonically active material and has sufficient energy to induce a detectable emission from the photonically active material .

7. A method according to claim 1, further characterized in that when excited by the light coming from the excitation source, the photonically active material produces a secondary emission that is substantially brighter than when excited by the light coming from the source of stimulus, so that a high signal spectral analysis is achieved at the noise proportion of the coded identification emission.

8. A method according to claim 1, further characterized in that the method comprises initial calibration steps of: providing a calibration source for generating light; co-propagating a portion of the light from the calibration source with a portion of the light from the excitation source and the response of the photonically active material to the light from the excitation source; and constructing a calibration table to associate the signaling directions of the excitation source with directions from which an emission is received in response to light from the stimulus source.

9. A method according to claim 1, further characterized in that it comprises a step for selecting articles based on the coded identification emission detected.

10. A method according to claim 1, further characterized in that the coded identification emission detected consists of an optical code to identify at least one feature of the article.

11. A method for identifying articles, comprising the steps of: providing a plurality of emitting articles by themselves, each emitting article by itself has at least a portion that includes a photonically active material; for each article, identifying a location of at least a portion that includes the photonically active material by detecting an issuance of the emitting article by itself; point to a source of excitation at the identified location; illuminate at least a portion at the location identified with light from the excitation source; and detecting a coded emission of identification of the photonically active material in response to light from the source of excitation; and identify a single article of the articles based on the encoded identification issue detected.

12. A method according to claim 11, further characterized in that the emitting articles by themselves consist of one of the articles bioluminiscent.es and chemiluminescent.

13.- An apparatus to identify articles, comprising: a | source of stimulus that generates light to illuminate at least a portion of each 5 article, that portion comprises a photonically active material; a first detector for identifying a location of at least said portion comprising the photonically active material by detecting an emission of said photonically active material in response to light from the stimulus source; an excitation source for generating light; a signaling system for signaling the source of excitation at said identified location, so that the light from the excitation source illuminates at least a portion at said identified location; and a second detector for detecting an encoded emission of information from said photonically active material in response to light 15 coming from the source of excitement.

14. An apparatus according to claim 13, further characterized in that the stimulus source consists of a radiant source whose emission is absorbed by the photonically active material and which has sufficient energy to induce a detectable secondary emission from said source. photonically active material.

15. An apparatus according to claim 13, further characterized in that the first detector consists of an electronic camera.

16. - An apparatus according to claim 13, further characterized in that the excitation source consists of a laser.

17. An apparatus according to claim 13, further characterized in that the excitation source consists of one between a Nd: YAG laser of double frequency, Q switched and pumped by magnesium lamp; a Nd: YAG laser of double frequency, Q switched and pumped by diodes; and devices derived from non-linear devices that include Nd: YAG lasers and other laser crystals.

18. An apparatus according to claim 13, further characterized in that the means for signaling consists of a beam steering device having at least one degree of freedom.

19. An apparatus according to claim 13, further characterized in that it comprises a conveyor for moving said articles through a field of view of said apparatus.

20. An apparatus according to claim 13, further characterized in that it comprises a calibration subsystem for associating an emission of the first detector with a control input of said signaling system.

21. A method for determining information about an object, comprising the steps of: providing an object to have at least a portion consisting of a photonically active material; To light at least that portion with light of stimulus; detect a first emission of the photonically active material in response to the stimulus light; identify a location of at least a portion that uses the first detected emission; signaling a beam of excitation light at the identified location; illuminate at least that portion at the location identified with the excitation light; detecting a second emission of the photonically active material in response to the excitation light; and decoding the second emission to obtain information that describes at least one characteristic of the object.

22. A method according to claim 21, further characterized in that the lighting steps employ two separate light sources.

23. A method according to claim 22, further characterized in that one or both light sources consist of a lamp, and wherein one or both light sources consist of a laser.

24. A method according to claim 21, further characterized in that the lighting steps employ the same light source.

25. A method according to claim 24, further characterized in that the light source consists of a lamp or a laser.

26.- A method according to claim 21, further characterized in that the lighting step of at least a portion with the stimulus light comprises a step to operate one of the following: an X-ray source, a magnesium lamp, a fluorescent lamp, an incandescent lamp or a laser.

27. - A method according to claim 21, further characterized in that the illumination step of said at least said portion at the location identified with the excitation light comprises a || step to operate a xenon magnesium lamp.

28. A method according to claim 21, further characterized in that the illumination step of said at least said portion at the location identified with the excitation light comprises a step for generating a plurality of wavelengths of light.

29. A method according to claim 28, | 10 further characterized in that the generation step includes steps for generating a first excitation light having a first wavelength; and generating another excitation light, having a second wavelength, from the first excitation light.

30. A method according to claim 21, 15 further characterized in that the detection step of the first emission utilizes an imager having a two-dimensional field of view; and wherein the step to indicate the excitation light beam employs a signaling system that operates in two dimensions.

31. A method according to claim 21, further characterized in that the step of providing the object includes a step to move the object, wherein the step of pointing the excitation light beam signals the beam along the an axis.

32. A method according to claim 21, further characterized in that the detection step of the first emission employs one between a position detection detector or an imaging camera system. f |

33. A method according to claim 21, 5 further characterized by a step to reduce the parallax between a field of view of a stimulus light source and a field of view of an excitation light source.

34.- A method according to claim 33, further characterized in that the step to reduce the parallax includes the f? 10 steps to generate a calibration table that relates an output of a system that detects the first emission for a system that signals the excitation light beam; and that employs the calibration table by indicating the excitation light beam based on the system output that detects the first emission.

35.- A method according to claim 21, further characterized in that the detection step of the second emission comprises the steps of spectrally producing the emissions along an axis and spatially producing the emissions throughout of a second axis.

36. A method according to claim 35, further characterized in that the step for decoding comprises a step for analyzing the emissions in spectral images and the emissions in spatial images to obtain the information describing at least one characteristic of the object.

37. A method according to claim 21, further characterized in that the step for detecting the first emission employs an emission detector that has a field of view; and wherein the field of view of the emission detector is separated from a field of view of a signaling system that signals the excitation light beam.

38.- A method according to claim 21, further characterized in that the step for detecting the first emission employs an emission detector having a field of view; and wherein the field of vision of the emission detector is directed through a signaling system that signals the excitation light beam.

39.- A method according to claim 21, further characterized in that the step to detect the second emission comprises another step to detect at least one property of the object.

40- A method according to claim 39, further characterized in that at least said property consists of color.

41. A method according to claim 21, further characterized in that the step to illuminate at least said portion with stimulus light comprises a step to generate a plurality of wavelengths of light. 42.- A method for determining information about an object, comprising the steps of: providing an object to have a plurality of regions, each consisting of a photonically active material; Illuminate at least a portion of the object with stimulus light; detect a first emission of the photonically active material in response to the stimulus light; identify a location of each of the plurality of regions of the | first emission detected; point out a ray of excitement light, in turn, in 5 each location identified to illuminate, in turn, each region with the excitation light; in response to the excitation light, detecting a second emission of the photonically active material in each illuminated region; and decoding a plurality of the second emissions to obtain information describing at least one characteristic of the object. F? 10 43.- A method for identifying each of the plurality of objects, comprising the steps of: providing each of the plurality of objects to have at least one region consisting of a photonically active material; illuminate the plurality of objects with stimulus light; detecting, from each object, a first emission of the photonically active material in response to the stimulus light; identifying a location of each of the plurality of regions of the first detected emission; point out a beam of excitation light, in turn, at each identified location to illuminate, in turn, each region with the excitation light; in response to the excitation light, detecting a second emission of the photonically active material in each illuminated region; and decoding each of the second emissions to identify each of a plurality of objects.