Abstract:
An inventory control process includes the association of an inventory item with a reusable container at an origination point. The container is inclusive of a passive or active identification tag. The container is transported within the range of a transponder able to share information with the identification tag. Upon reaching a destination point, the inventory item is unpacked from the container and the container recycled for association with a new inventory item. An inventory delivery device includes a reusable container labeled with an active identification tag. An inventory item is inserted within the container. A disposable tamper-evident seal retaining the inventory item with the container is provided. The device is particularly well suited for transportation for timely and high clinical value items within a medical care setting.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation-in-part of U.S. patent application Ser. No. 11/441,309 filed May 25, 2006, which claims priority of U.S. Provisional Patent Application Ser. No. 60/684,276 filed May 25, 2005. This application is also a continuation-in-part of U.S. patent application Ser. No. 11/056,808 filed Feb. 11, 2005, which claims priority of U.S. Provisional Patent Application Ser. No. 60/558,629 filed Apr. 1, 2004. These aforementioned priority applications are hereby incorporated by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention in general relates to the tracking of articles within an organization and in particular to a process for affixing an identifying label to a container and inventory associated with the container. 
       BACKGROUND OF THE INVENTION 
       [0003]    Radiofrequency identification (RFID) tags are broadly classed as to passive and active tags. While a passive tag lacks a power supply in electrical communication with the tag, an active identification tag has a coupled power supply and actively broadcasts a signal. Generally, a passive tag tends to be less expensive, more compact and has a longer operating lifetime than a comparable active tag, at the expense of requiring more complex tag interrogation systems. An impediment to the use of RFID tags in inventory management systems is the initial effort associated with individual inventory items and the comparative cost of tags relative to inventory items. While the cost of passive identification tags is generally comparatively lower than that of active tags, the cost of the tag and labor associated with affixing such tags remains considerable. 
         [0004]    Thus, there exists a need for an inventory management system that provides for the efficient reuse of identification tags while avoiding the need to affix an individual tag to each inventory item or lot. 
       SUMMARY OF THE INVENTION 
       [0005]    An inventory control process includes the association of an inventory item with a reusable container at an origination point. The container is inclusive of a transponder equipped optical identification tag. The container is transported within the range of a transponder able to share information with the identification tag. Upon reaching a destination point, the inventory item is unpacked from the container and the container recycled for association with a new inventory item. 
         [0006]    An inventory delivery device includes a reusable container labeled with an active identification tag. An inventory item is inserted within the container. A disposable tamper-evident seal retaining the inventory item with the container is provided. The device is particularly well suited for transportation for timely and high clinical value items within a medical care setting. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
         [0007]      FIG. 1  is a schematic diagram of the steps involved in practicing the present invention; 
           [0008]      FIG. 2  is a partial cutaway view of an inventive recyclable tagged container; 
           [0009]      FIG. 3  is a schematic diagram of a preferred embodiment showing an integrated circuit with functions supporting its role as an optical transponder-equipped ID (OID) tag; 
           [0010]      FIG. 4  is a schematic diagram of an alternate embodiment showing an integrated circuit with functions supporting multiple optional application uses as an optical transponder-equipped ID tag, an RFID tag or a combination O/RFID tag; 
           [0011]      FIG. 5  is a schematic diagram of an alternate embodiment of the invention operating as a passive optical identification tag; and 
           [0012]      FIG. 6  is a schematic diagram of an alternate embodiment of the invention operating as an optical transponder-equipped ID (OID) tag differing from that embodiment depicted in  FIG. 3  in that the outgoing optical signal is produced by reflecting and modulating the incoming optical signal rather than being produced de novo. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0013]    The present invention has utility as an inventory management system that efficiently reuses identification tags and limits handling associated with tag affixation. These improvements are achieved by affixing a radiofrequency identification (RFID) or a transponder equipped optical identification tag onto a reusable bin or container. It is appreciated that dimensions, construction materials and shape are largely dictated by the particulars of the inventory items to be handled. The items entered into a tagged container are noted by a conventional technique such as manual recordation or barcode scanning. The items are then associated with the identification tag. As the inventory associated container moves through an organization, the location of the container and therefore the associated contents are noted. 
         [0014]    The present invention is particularly well suited for inventory management in complex organizational settings with individualized and small lot delivery of goods. Organizations well suited to benefit from the present invention illustratively include hospitals and customized manufacturing facilities. The tracking of high clinical value materials or time-sensitive materials in a medical setting is of particular concern. Such materials illustratively include medications, blood or tissue samples, radioactive reagents, and medical procedure kits. 
         [0015]    Referring now to  FIG. 1 , an inventive process is disclosed generally at  10 . The placing of at least one inventory item in connection with a container having an identification tag  12  includes associating each inventory item with a respective container tag  14 . The association is readily performed by manual data entry onto paper or a computer, or preferably through the use of optical or magnetic barcode reading. After associating inventory items with a container identification tag  14 , the container is transmitted through the supply system  16 . 
         [0016]    Preferably, the tag  14  is an active tag. An active tag is more preferably rechargeable. Recharging is readily performed by exposing a tag ultra capacitor to the electrical field associated with a recharging coil. Alternatively, a passive tag is interrogated by a proximal reader encountered at a transit terminus or in transit. 
         [0017]    During transportation of the container, it is brought within communicative proximity to a transponder  18  so as to provide near real-time tracking of the container en route and identification of transportation bottlenecks within the system. It is appreciated that the nature of the transponder operative herein is dependent on whether the identification tag is radiofrequency or optical, active or passive. At the end of container transport, the container arrives at the destination where the individual inventory items associated with the container are unpacked and the container recycled for another delivery  20 . Container integrity in the course of transport is maintained by securing the container with a tamper-resistant seal to prevent inventory pilfering and/or loss en route. 
         [0018]    It is appreciated that delivery time scheduling is readily performed such that containers arrive at the time of need, thereby decreasing the distributed inventory of inventory items stocked in wards, surgical suites, or treatment settings. Further, containers are readily prioritized within a delivery system. The performance of active checks of timetable delivery scheduling is performed to assess container flow. A check typically involves detection of all containers within the delivery system at a particular time. Periodic delivery checks are used as input data to a neural network routing program to efficiently utilize delivery bandwidth. 
         [0019]    The inventive system is particularly well suited for use with a pressurized tube delivery system. Use of the inventive system in conjunction with a tube delivery system in a preferred embodiment utilizes a neural network routing controller that is self-learning in assembling optimal routes between source and destination for a particular container. Self-learning route control programs and the underlying methodologies are conventional to the art. 
         [0020]    Referring to  FIG. 2 , an inventive container is shown generally at  30  where the container tag  14  is as described with respect to  FIG. 1 . The container  30  has a bottom  32  and a sidewall  34  defining a container volume  36 . The volume  36  is adapted to receive an inventory item I such as those having a barcode. The sidewall  34  terminates in a mouth  38  engaging a cap  40 . The cap  40  is secured to the mouth  38  by conventional means including complementary threads, press fit features, and a swivel mount. The tamper-evident or tamper-resistant seal  42  spans the interface between the cap  40  and sidewall  34 . A high tack adhesive tape is well suited to function as a seal  40 . The container tag  14  is secured into the container bottom  32  or sidewall  34 . A tag  14  is readily potted with a curable resin to permanently adhere the tag  14  in place. Alternatively, a tag is adhered to a container surface with an adhesive tape or molded into the container. It is also appreciated that a tag  14  is associated with a swivel attached cap permanently attached to the container. Human cognizable coding  42  and/or bar coding  44  are optionally affixed to a container  30  allowing for integration with other coding and inventory handling systems. 
         [0021]    The method of transmitting energy and signals between an ID tag and a corresponding interrogation device, hereafter referred to as “transmission mode”, can be distinguished from the informational functions of said tag. The term “transmission mode” is also intended to encompass directionality of transmission as in the terms “transmission mode into the tag” and “transmission mode away from the tag”. Transmission modes may include a novel transmission mode alone or in combination with a conventional mode such as RF. For example, a transponder-equipped ID tag with optical transmission modality optionally has a corresponding external interrogation device with powerful magnification lenses and photomultiplier technologies thereby allowing successful interrogation of the tag despite extremely small physical size and low power output of the tag. 
         [0022]    As used herein, transponder ID tags are defined to be “informationally equivalent” if they report to their corresponding interrogating devices the same information despite have differing methods of transmission. Availability of such informationally equivalent tags is advantageous to an end user in that they would have available, beyond RF methods, alternate methods of transmission which may be better suited to specific applications and environments. Availability of such informationally equivalent tags is advantageous to end users in that they would have available several varieties of ID tags which are mutually compatible with respect to information content and external pre-interrogation and post-interrogation protocols and uses of the tag information. The directionality associated with an optical beam is intermediate between the area broadcast of an RF signal and the close proximity requirements of conventional barcode readers, and as such affords greater specificity in those tags subject to reading. 
         [0023]    With the emergence of an RFID standards authority, a tag according to the present invention is readily tracked to a specific source. Owing to the data-carrying capacity of an optical or hybrid tag according to the present invention, a large number of tags are capable of rapid interrogation. The size of an inventive tag on the scale of 1 to 500 microns allows for the labeling of previously untaggable objects. Objects capable of incorporating an inventive tag include currency and production lots of products such as fertilizer, personal care products, plastics, consumer goods, tires, and glasses. 
         [0024]    Referring now to  FIG. 3 , a substrate  1  is provided which carries the components of the optical identification (OID) tag. The method of manufacture is preferably from a monolithic integrated circuit; yet various other methods of manufacture are operative herein. 
         [0025]    An incoming optical signal  2  is of wavelengths ranging from ultraviolet through visible to infrared. Its external source is monochromatic, for example a laser or photodiode, or polychromatic. An outgoing optical signal  110  is of wavelengths ranging from ultraviolet through visible to infrared. The optical transmitter  9  may be monochromatic, for example a laser or photodiode, or may be polychromatic. There is no requirement that the operating wavelength of the incoming optical signal and the outgoing optical signal be the same or different. Preferably, the outgoing signal is of a wavelength equal to or greater than the incoming signal, else a frequency doubling crystal is used. Both the incoming optical signal  2  and the outgoing optical signal  110  pass through an optional encapsulation  100  of the OID. Said encapsulation is optically transparent at the wavelengths appropriate to the combination of the incoming optical signal  2  and the optical energy receiver  3  as well the combination of the optical transmitter  9  and the outgoing optical signal  110 . The encapsulation is optionally partially or completely during use. Optionally, the encapsulation may be opaque with a window transparent at the corresponding wavelengths provided in the field of view of the optical energy receiver  3  and the optical transmitter  9 . Optionally, optical filtering (not illustrated) may be incorporated. 
         [0026]    The optical energy receiver  3 , containing a photosensitive structure, a coupling mechanism, a signal demodulator and a contained energy storage device, permits both power  5 ,  6  and signal  4  to be derived from the incoming optical energy  2 . The power is delivered  5  to the information processing mechanism  7  and is delivered  6  to the optical transmitter  9 . The information processing mechanism according to the present invention is encoded with information through techniques conventional to microelectronics and represents either physical or programmed encoding. Tag encoding illustratively includes a mechanism fashioned as an EPROM, uploaded software, and reconfigurable signal and/or power routing. Additional destinations and routings for the power are operative herein. The signal  4  is delivered to the information processing mechanism. Optionally, additional signals (not illustrated) are channeled directly between the optical energy receiver  3  and the optical transmitter  9 . It is appreciated that additional destinations (not illustrated) and routings (not illustrated) for the signal are possible but are not included in  FIG. 3  for visual simplification. 
         [0027]    The information processing mechanism  7  delivers output  8  to the optical transmitter  9  and, optionally, delivers feedback information to the optical energy receiver  3  to alter the characteristics of the optical energy receiver  3 . The information processing mechanism  7  may simply deliver an arbitrary number that had been recorded at time of manufacture or recorded at some later time. Alternatively, the information processing mechanism  7  may contain more elaborate informational functions such as encryptation, computation, environmental measurement and the like, as are commonly found resident on prior art RFID tags. It is appreciated that conventional information processing mechanisms are operative herein. 
         [0028]    The optical transmitter  9  receives power  6  and signal  8  as described above and produces an outgoing optical signal  10  which is detected by an external interrogation device, such as an optical receiver. 
         [0029]    Another preferred embodiment of the invention is schematically diagrammed in  FIG. 4 . In this embodiment, the OID functions described in reference to  FIG. 3  are augmented by inclusion of an RF transmitter into and away from the tag, optionally a method for enabling any combination of optical and RF reception and transmission. This embodiment will be referred to as an “O/RFID tag”. 
         [0030]    This preferred embodiment of the invention is schematically diagrammed in  FIG. 4 . A substrate  11  is provided which carries the components of the O/RFID tag. The method of manufacture is preferably a monolithic integrated circuit; various methods of manufacture are permitted within the scope of the invention. 
         [0031]    An incoming optical signal  120  is of wavelengths ranging from ultraviolet through visible to infrared. Its external source is monochromatic, for example a laser or photodiode, or polychromatic. An outgoing optical signal  35  is of wavelengths ranging from ultraviolet through visible to infrared. The optical transmitter  25  may be monochromatic, for example a laser or photodiode, or may be polychromatic. There is no requirement that the operating wavelength of the incoming optical signal and the outgoing optical signal be the same or different. Both the incoming optical signal  120  and the outgoing optical signal  35  pass through an optional encapsulation of the O/RFID tag. Said encapsulation  100  is optically transparent at the wavelengths appropriate to the combination of the incoming optical signal  120  and the optical energy receiver  13  as well the combination of the optical transmitter  25  and the outgoing optical signal  35 . The encapsulation  100  is optionally partially or completely during use. An encapsulant  100  illustratively includes glass. Optionally, the encapsulation  100  is opaque and a transparent window is provided in the field of view of the optical energy receiver  13  and the optical transmitter  25 . Optionally, optical filtering may be incorporated. An incoming RF signal  160  is of convenient wavelength as are commonly used in conventional RFID tags. An outgoing RF signal  360  is of convenient wavelength as are commonly used in conventional RFID tags. There is no requirement that the operating wavelength of the incoming RF signal and the outgoing RF signal be the same or different. Both the incoming RF signal  160  and the outgoing RF signal  360  pass through a conventional antenna connected to the O/RFID tag. As in conventional RFID tags, a single antenna may serve both to receive and transmit RF signals or separate antennas may be provided. As in conventional RFID tags, the antenna or antennas may be integrated onto the same substrate carrying the tag mechanisms or said antennas may optionally be carried beyond the substrate onto adjacent items where it may serve as an extended antenna or as the basis for additional functions such as security indicators and the like. 
         [0032]    The optical energy receiver  13 , containing a photosensitive structure, a coupling mechanism, a signal demodulator and a contained energy storage device, permits both power  14  and signal  15  to be derived from the incoming optical energy  120 . The inventive RF energy receiver  17 , connected to an antenna, a coupling mechanism, a signal demodulator and a contained energy storage device, permits both power  180  and signal  19  to be derived from the incoming RF energy  160 . Power derived from the optical energy receiver  140  and power derived from the RF energy receiver  180  converge to a common power mechanism  200 . Optionally, the function of the energy storage device contained within the optical energy receiver and the function of the energy storage device contained within the RE energy receiver may be combined in a single energy storage device, for example an electrical capacitor, which is located within the common power mechanism  200 , The common power mechanism  200  is controlled via an apparatus which is schematically indicated  37 . The common power mechanism outputs power which is distributed via power conduits  21 ,  22 ,  24 ,  26  and power distribution nodes  23  throughout the O/RFID tag. Said power distribution nodes  23  are controlled via an apparatus that is schematically indicated  37 . Power is delivered  21  to the information processing mechanism  30  and is delivered  22  to a power distribution node  23  and then onward towards  24  the optical transmitter  25  and towards  26  the RF transmitter  27 . Additional destinations (not illustrated) and routings (not illustrated) for the power are possible but are not included in  FIG. 2  for visual simplification. Signal  15  emerging from the optical energy receiver  13  and signal  19  emerging from the RE energy receiver  17  converge to a common signal mechanism  28  controlled via an apparatus which is schematically indicated  37 . From the common signal mechanism  28 , information is delivered  29  to the information processing mechanism. It is appreciated that additional destinations and routings for signals are possible but are not included in  FIG. 4  for visual simplification. 
         [0033]    The information processing mechanism  300  delivers its signal output  31  to a signal output switch  320  controlled via an apparatus which is schematically indicated  37 . From the signal output switch  320 , signal information is routed  33 ,  340  to either the optical transmitter  25  and/or the RF transmitter  27 . Optionally, the information processing mechanism  300  delivers additional signal information  380  to the control apparatus  37  and delivers additional signal information to the energy receivers  13 ,  17  and energy transmitters  25 ,  27  to alter their respective characteristics. The information processing mechanism  300  may simply deliver an arbitrary number which had been recorded at time of manufacture or recorded at some later time. Alternatively, the information processing mechanism  300  may contain more elaborate informational functions such as encryptation, computation, environmental measurement and the like, as are commonly found resident on conventional RFID tags. 
         [0034]    The optical transmitter  25  receives power  24  and signal  33  as described above. It produces an outgoing optical signal  35  which is detected by an external interrogation device. The RF transmitter  27  receives power  26  and signal  340  as described above. It produces an outgoing RE signal  360  which is detected by an external interrogation device. 
         [0035]    An apparatus  37  is provided to control the characteristics and activation of functional modules of the O/RFID tag. Indicated in  FIG. 4  are power controllers  200 ,  23  and signal switches  28 ,  320  controlled by the apparatus  37 . The apparatus  37  can be reversibly or irreversibly programmed at the time of manufacture or at some later time. Optionally, information provided  380  by the information processing mechanism  300  can be used to program appreciated that additional sources and routings for information to be used to program the apparatus are operative herein. 
         [0036]    In an alternate embodiment depicted with respect to  FIG. 5 , a passive optical identification tag is shown generally at  54 . An incoming optical signal  55  is provided of a wavelength ranging from ultraviolet through visible to infrared. The source of the incoming optical signal  55  is appreciated to be monochromatic, for example a laser or photodiode, or polychromatic, as obtained from an incandescent light source. The passive optical identification tag  54  includes an optical retroreflective transponder  56  that interacts with the incoming optical signal  55  to return a reflected output signal  57  communicating an identification code therewith. Methods of encoding a tag with a unique code illustratively include the deposition of bandpass filter coatings onto a reflective surface of the passive optical identification tag  54 ; the placement of one or more dye molecules onto a surface  58  of the transponder  56 , the dye molecules being stimulated by the incoming optical signal  55  so as to emit a characteristic reflection wavelength, fluorescence, or phosphorescence; and scoring the reflective surface  58  to create light scattering of an incoming optical signal of a predetermined magnitude. 
         [0037]    A passive optical identification tag  54  interrogated by a polychromatic light source coated with at least one optical bandpass filter material upon reflection of an incoming optical signal  55  will return a reflected optical signal  57  with only portions of the incident incoming optical signal  55  being present. Typical channel band centers for miscible light filters are 450 nanometers and progressing at 50 nanometer increments so as to create channel bandwidths of approximately 20 nanometers. Based on the filter bandwidth and the number of coatings available, used in combination with the polychromatic light source, an inventive passive optical tag is capable of encoding dozens of unique descriptor codes. The production of a bandpass passive optical identification tag according to the present invention is readily accomplished through the coating of a reflective metal or semiconductor substrate having a known reflectivity with layers of optical filter coatings. It is appreciated that the substrate is in the form of a wire, wafer, or particle. Organic optical filter coatings are readily applied through dip or spin coating, while inorganic optical filter coatings are typically applied through chemical vapor deposition, physical vapor deposition, or sputter coating. In the case of a wire or wafer substrate, the substrate is thereafter divided to be sized on the order of 1 to 500 microns. It is further appreciated that the passive optical tag is readily encapsulated within a protective coating that if optically transparent allows for interrogation of the passive optical identification tag  54  or alternatively is removed upon recovery of the tag and prior to incoming optical signal interrogation. 
         [0038]    A passive optical identification tag according to the present invention coated with dye molecules having characteristic absorption, fluorescent, or phosphorescent signatures are prepared in a like manner to those described above having optical bandpass coatings thereon. It is appreciated that a passive optical identification tag according to the present invention is readily produced that has a combination of preselected dye molecules coated thereon and bandpass filters. Dye molecules operative herein include any organic, inorganic, or organometallic compound that is not ubiquitous to the tag environment, has a degradation lifetime in the tag environment on a timescale suitable for labeling, and a known absorption and/or emission spectrum under incoming optical signal illumination. With the use of dye species, it is appreciated that the passive optical identification tag need not be reflective, and instead a porous silica, aerogel, or colloidal substrate containing dye molecules is operative herein. In the instance of dye labeled passive optical tags, it is appreciated that time resolve labeling is readily accomplished with a dye having a comparatively short lifetime in the tag environment prior to degradation. Through application of Beer&#39;s Law and a known initial quantity of dye associated with the tag, the time from labeling until interrogation is readily extrapolated subject to variations in tag environment and individual tag exposures. Alternatively, temporal labeling of a tag is provided by varying the quantity of each of two or more dyes that are applied to a particular tag in a preselected amount that varies with time. The relative signals received from interrogating the tag are then correlated with the concentration of each dye present in order to extract the time of label. It is appreciated that a passive optical tag including dye species is interrogated with either monochromatic or polychromatic incoming optical signals, depending on the physical property by which a returned optical signal is generated. 
         [0039]    A passive optical tag having a light scattering grating associated therewith is preferably formed by lithographic etching of a reflective metal or semiconductor substrate. However, it is appreciated that a grating structure is readily cast onto a wafer substrate using a grating mold as is common to the optical arts. With a grating type passive optical identification tag, the measure of the incident incoming optical signal relative to the reflected optical signal at a preselected angular orientation is sufficient to read the code from a given optical tag. It is appreciated that an optical grating type passive optical identification tag is operative alone or in combination with bandpass filter coatings and/or dye species associated therewith. Additionally, as detailed above, a grating type passive optical identification tag is readily encapsulated to protect the grating structure until such time as interrogation is intended. 
         [0040]    A passive optical identification tag interrogation system as detailed above includes a monochromatic or polychromatic light source. Interrogation of the reflected optical signal from a tag is preferably accomplished with a spectrophotometer. Owing to the small size of an individual inventive tag, interrogation from a field of view potentially containing a large number of tags is readily accomplished with a microscope delivering instant light and receiving reflected light by way of optical fibers. In this way, a taggant is spatially resolved within a field. Placing the optical stage and optic system under the control of a computer operating an algorithm to identify tags within the optical field affords automated interrogation of tags within the field. Coupling the motor driven and computer controlled stage with a robotic arm capable of placing sample slides from the stage allows for the automated screening of samples with the interrogation of tags found on each of the samples. 
         [0041]    Depicted in  FIG. 6  is an alternate embodiment of the invention as depicted in  FIG. 3  in which is substituted, for the outgoing optical transmitter identified as component  9  in  FIG. 3 , a reflector  48  and an optical modulator  50 . A substrate  39  is provided which carries the components of the optical identification (OID) tag. The method of manufacture is preferably a monolithic integrated circuit; yet various other methods of manufacture are operative herein. 
         [0042]    An incoming optical signal  400 ,  41  is of wavelengths ranging from ultraviolet through visible to infrared. Its external source is monochromatic, for example a laser or photodiode, or polychromatic. One portion of the incoming optical signal  400  is captured by a optical energy receiver  420  and another portion of the incoming optical signal  41  strikes a reflective surface  48  and then continues on  49  to be modulated by an optical beam modulator  50 . An outgoing optical signal  51 ,  52 ,  53  is of wavelengths ranging from ultraviolet through visible to infrared. The optical reflector  48  may be integrated with the other components in a monolithic structure or may be external to the other components. The optical modulator  50  may be integrated with the other components in a monolithic structure or may be external to the other components. The modulator  50  may be transmissive as depicted in  FIG. 4  or may be reflective (not illustrated). Should the modulator be reflective, then its function can be merged with that of the reflector  48  to provide a combination reflector/modulator (not illustrated). The optical modulator encodes information on the outgoing reflected optical signal  51 ,  52 , or  53  by varying any combination of the phase, wavelength, and/or intensity of the incoming signal  41 . There is no requirement that the operating wavelength of the incoming optical signal and the outgoing optical signal be the same or different. Both the incoming optical signal  400 ,  41  and the outgoing optical signal  51 ,  52 ,  53  pass through an optional encapsulation  100  of the OID. Said encapsulation  100  is optically transparent at the wavelengths appropriate to the combination of the incoming optical signal  40 ,  41  and the optical energy receiver  420  as well the combination of the optical reflector  48 , optical modulator  50  and the outgoing optical signal  51 ,  52 ,  53 . The encapsulation is optionally partially or completely during use. Optionally, the encapsulation  100  may be opaque with a window transparent at the corresponding wavelengths provided in the field of view of the optical energy receiver  420 , optical reflector  48  and the optical modulator  50 . Optionally, optical filtering (not illustrated) may be incorporated. 
         [0043]    The optical energy receiver  420 , containing a photosensitive structure, a coupling mechanism, a signal demodulator and an optional contained energy storage device, permits both power  44 ,  47  and signal  43  to be derived from a portion of the incoming optical energy  400 . The power derived from the incoming optical energy is available to energize the mechanisms of the transponder as illustratively indicated by  44 , indicating energy delivery to the information processing mechanism  45 , and by  47  indicating energy delivery to the optical modulator  50 . The information processing mechanism  45  according to the present invention is encoded with information through techniques conventional to microelectronics and represents either physical or programmed encoding. Tag encoding illustratively includes a mechanism fashioned as an EPROM, uploaded software, and reconfigurable signal and/or power routing. Additional destinations (not illustrated) and routings (not illustrated) for the power are possible but are not included in  FIG. 6  for visual simplification. The signal  43  is delivered to the information processing mechanism. Optionally, additional signals (not illustrated) are channeled directly between the optical energy receiver  420  and the optical modulator  50 . It is appreciated that additional destinations (not illustrated) and routings (not illustrated) for the signal are possible but are not included in  FIG. 6  for visual simplification. 
         [0044]    The information processing mechanism  45  delivers its output  46  to the optical modulator  50  and, optionally, delivers feedback information (not illustrated) to the optical energy receiver  420  to alter the characteristics of the optical energy receiver  420 . Additional destinations (not illustrated) and routings (not illustrated) for the information are possible but are not included in  FIG. 6  for visual simplification. The information processing mechanism  45  may simply deliver an arbitrary number that had been recorded at time of manufacture or recorded at some later time. Alternatively, the information processing mechanism  45  may contain more elaborate informational functions such as encryptation, computation, environmental measurement and the like, as are commonly found resident on prior art RFID tags. It is appreciated that conventional information processing mechanisms are operative herein. 
         [0045]    The optical modulator  50  receives power  47  and signal  46  as described above. Additional sources (not illustrated) and routings (not illustrated) for the power are possible but are not included in  FIG. 6  for visual simplification. It produces an outgoing optical signal  51  which is detected by an external interrogation device. 
         [0046]    In another alternate embodiment a reflector and an optical modulator, such as those described with respect to components  48  and  50  of  FIG. 6 , are substituted for the outgoing optical transmitter identified as component  25  in  FIG. 4 . 
         [0047]    An interrogation device, external to the inventive tag, is provided. In one embodiment, mechanical guides hold a tag or a tagged item in a predetermined location and orientation. A laser illuminates the same predetermined position and a photodetector receives the outgoing optical signal. Further information processing is by conventional means. An alternate embodiment of the external interrogation device allows the interrogating laser beam to scan a range of positions in a space filling pattern. Optionally optical elements may be incorporated into the tag or the surface of the tagged item in order to simplify the recognition of the tag. Once the tag is located, further transmission and reception of optical signals proceeds as above. In an additional embodiment of the invention, optical means of interrogation can be combined with other means of interrogation including optical barcode, radiofrequency, acoustic and magnetic technologies. Other forms and configurations of external interrogating devices are possible and are included within this invention. 
         [0048]    An inventive tag has met with considerable acceptance in situations where there is no tolerance for ambiguity as to the identity of the tag being read. The following exemplary usage further illustrates these advantages. 
         [0049]    Patents and publications mentioned in the specification are indicative of the levels of those skilled in the art to which the invention pertains. These patents and publications are incorporated herein by reference to the same extent as if each individual application or publication was specifically and individually incorporated herein by reference. 
         [0050]    The foregoing description is illustrative of particular embodiments of the invention, but is not meant to be a limitation upon the practice thereof. The following claims, including all equivalents thereof, are intended to define the scope of the invention.