Patent Publication Number: US-2004049428-A1

Title: Wireless environmental sensing in packaging applications

Description:
FIELD OF THE INVENTION  
       [0001] The claimed invention relates to wireless communication systems. In particular, the invention relates to the use of sensing devices coupled to RFID components on items of inventory for monitoring, storing, and relaying environmental and other information.  
       BACKGROUND  
       [0002] Radio frequency identification (RFID) technology has been used for wireless automatic identification. An RFID system typically includes a transponder, an antenna, and a transceiver with a decoder. The transponder, which typically includes a radio frequency integrated circuit, and antenna may be positioned on a substrate, such as an inlet or tag. The antenna serves as a pipeline between the circuit and the transceiver. Data transfer between the transponder and transceiver is wireless. RFID systems may provide non-contact, non-line of sight communication.  
       [0003] RF transponder “readers” utilize an antenna as well as a transceiver and decoder. When a transponder passes through an electromagnetic zone of a reader, the transponder is activated by the signal from the antenna. The transceiver decodes the data on the transponder and this decoded information is forwarded to a host computer for processing. Readers or interrogators can be fixed or handheld devices, depending on the particular application.  
       [0004] Several different types of transponders are utilized in RFID systems, including passive, semi-passive, and active transponders. Each type of transponder may be read only or read/write capable. Passive transponders obtain operating power from the radio frequency signal of the reader that interrogates the transponder. Semi-passive and active transponders are powered by a battery, which generally results in a greater read range. Semi-passive transponders may operate on a timer and periodically transmit information to the reader. Transponders may also be activated when they are read or interrogated by a reader. Transponders may control their output, which allows them to activate or deactivate apparatus remotely. Active transponders can initiate communication, whereas passive and semi-passive transponders are activated only when they are read by another device first. Active transponders can supply instructions to a machine and then the machine may then report its performance to the transponder. Multiple transponders may be located in a radio frequency field and read individually or simultaneously. Sensors may be coupled to the transponders to sense an environmental condition.  
       SUMMARY  
       [0005] According to the invention, a system is provided for monitoring an environmental condition associated with an item of inventory along a distribution chain having a plurality of locations. The plurality of locations include at least a point of origin and a final destination. The system comprises at least one item of inventory, an RF transponder associated with the at least one item of inventory, at least one environmental condition sensor in communication with the RF transponder on the at least one item of inventory, and a power source for powering the RF transponder and the at least one environmental condition sensor. The transponder includes an RF processor having an antenna coupled to the RF processor. The RF transponder receives an environmental condition from the environmental condition sensor for storage as environmental condition data. The system also includes a log of location data, a log of environmental condition data, and a reporting infrastructure for processing the location data and the environmental condition data.  
       [0006] The power source may comprise a battery that is coupled to the sensor and the transponder, or an RF reader that powers the transponder and sensor to transmit a sensed reading to the transponder. The reporting infrastructure may include a computer processor.  
       [0007] The invention also concerns a method of tracking an environmental condition associated with an item of inventory along a distribution chain having a plurality of locations. The plurality of locations include at least a point of origin and a final destination. The method comprises providing an item of inventory having an associated RF transponder, an environmental condition sensor, and a power source. The power source is for powering the environmental condition sensor to sense an environmental condition. The method also includes repeatedly powering the RF transponder and the environmental condition sensor as the item of inventory travels along the distribution chain to read the environmental condition and generate a log of environmental condition data. The method further includes repeatedly determining a location of the item of inventory as the item of inventory travels along the distribution chain and generating a log of location data and correlating the log of location data and the log of environmental condition data using a reporting infrastructure. 
     
    
    
     BRIEF DESCRIPTION OF THE DRAWING FIGURES  
     [0008]FIG. 1 is a schematic view of one embodiment of a distribution chain for an item of inventory according to the system of the present invention, showing electronic recording of environmental condition data and manual recording of location data;  
     [0009]FIG. 2 is a graph showing an example of temperature as a function of location and time for an item of inventory that travels along a distribution chain like that in FIG. 1;  
     [0010]FIG. 3 is a schematic view of another embodiment of a distribution chain according to the invention showing electronic recording of environmental condition data and manual recording of location data;  
     [0011]FIG. 4 is a schematic view of another embodiment of a distribution chain according to the invention showing electronic recording of environmental condition data and manual recording of location data;  
     [0012]FIG. 5 is a graph showing another example of temperature as a function of location and time for an item of inventory that travels along a distribution chain like that of FIG. 4;  
     [0013]FIG. 6 is a schematic view of yet another embodiment of a distribution chain according to the invention showing electronic recording of environmental condition data and manual recording of location data;  
     [0014]FIG. 7 is a schematic view of another embodiment of a distribution chain according to the invention showing electronic recording of both environmental condition data and location data;  
     [0015]FIG. 8 is a graph showing an example of shock as a function of location and time for an item of inventory that travels along a distribution chain like that of FIG. 7;  
     [0016]FIG. 9 is a schematic view of another embodiment of a distribution chain according to the invention showing electronic recording of both environmental condition data and location data;  
     [0017]FIG. 10 is a schematic view of yet another embodiment of a distribution chain according to the invention showing electronic recording of both environmental condition data and location data;  
     [0018]FIG. 11 is a schematic view of another embodiment of a distribution chain according to the invention showing electronic recording of both environmental condition data and location data;  
     [0019]FIG. 12 is a perspective view of a paper roll showing the inner core of the paper roll in phantom, with an RF inlet, sensor and battery installed on the core according to the present invention;  
     [0020]FIG. 13 is a perspective view of a box showing an RF inlet, sensor, and battery installed on an exterior surface of the box;  
     [0021]FIG. 14 is a perspective view of a box showing an RF processor, antenna, and sensor installed on an exterior surface of the box; and  
     [0022]FIG. 15 is a schematic view of an item of inventory that incorporates a product positioned inside a product packaging, with the RF transponder and sensor coupled to the item of inventory at a variety of locations according to the present invention. 
    
    
     DETAILED DESCRIPTION  
     [0023] A system for monitoring an environmental condition associated with an item of inventory  12  and its various components are shown in FIGS.  1 - 15 . The system tracks an environmental condition for an item of inventory  12  along a distribution chain  10 . The system preferably includes an RF transponder  14  coupled to the item of inventory and an environmental condition sensor  16  coupled to each transponder  14 . A power source is utilized to power the sensor to sense an environmental condition and to transmit the environmental condition data to the transponder. The system also utilizes a log of location data and environmental condition data as a function of time, and a reporting infrastructure for correlating the location and condition data. The system provides an automated means for measuring, recording, and relaying environmental measurements in or about an item of inventory for real time, continuous monitoring of the item&#39;s environmental conditions throughout the distribution cycle. The system is useful in foregoing human intervention for measuring and recording physiological and chemical characteristics associated with the item of inventory  12 .  
     [0024] The distribution chain  10  has a plurality of locations L and will typically include a point of origin L 1 , such as a manufacturer or distributor, and a final destination LE, such as a retailer or consumer. The plurality of locations L may also include intermediate locations L 2 , L 3  between the point of origin L 1  and the final destination LE. Typical locations among the plurality include the manufacturer, wholesaler, distributor, retailer, and consumer. The point of origin L 1  may lie at the manufacturer&#39;s warehouse and coincide with the time the item of inventory leaves the manufacturer. Alternatively, the point of origin L 1  may be a point before or after the item of inventory  12  leaves the warehouse. It may be desirable to track the item of inventory  12  along the manufacturing process, which would require that the RF transponder  14  and sensor  16  be coupled to the item of inventory  12  at a point before the item of inventory  12  is completed and before it leaves the warehouse. Alternatively, it may be desirable to track the item of inventory  12  from an intermediate point L 2 , L 3 , which could be labeled as the point of origin L 1 . For instance, it may be desirable by a distributor to track the item of inventory  12  after it leaves the distributorship before it arrives at the final destination LE. Moreover, the final destination LE does not necessarily have to correspond to the end user. The final destination LE may alternatively correspond to an intermediate point along the distribution chain  10 . Other locations, or fewer locations, may also be utilized in the distribution chain  10 , depending on the product and its mechanism for distribution.  
     [0025] FIGS.  1 ,  3 - 4 ,  6 - 7 , and  9 - 11  show a distribution chain  10  that includes a point of origin L 1 , a final destination LE, and two intermediate locations L 2 , L 3 . The figures are for illustration purposes only, the invention not being limited to or requiring four locations. More than four locations may be utilized. Alternatively, fewer than four locations may be utilized, such as a distribution chain that includes only a point of origin and a final destination.  
     [0026] Referring to FIGS.  12 - 15 , the system is centered around an item of inventory  12 , such as a roll of paper, a box, a pallet, a packaging substrate, a package, or another item of inventory. The system tracks both the location of the item of inventory  12  as a function of time and an environmental condition as a function of time. The system correlates the location and environmental condition data to provide the user with data for determining whether any defects exist in the inventory that were caused during the distribution process, as shown graphically in FIGS. 2, 5, and  8 . For example, items of inventory are often susceptible to damage caused by shock, excessive temperature, or excessive humidity levels, among other factors which are often product specific. The present invention can track these levels and correlate the levels with a location L 1 , L 2 , L 3 , LE for each item of inventory  12  to determine, for instance, if a temperature sensitive product has been left on a loading dock in 90° F. (32.2° C.) heat (FIG. 2), or a shock sensitive item of inventory has been dropped (FIG. 8), or a humidity sensitive item has been left out in the rain. Since the present invention tracks both environmental condition and location data, it is possible to determine where in the distribution chain  10  the damage occurred. This is highly desirable, particularly where an item of inventory  12  passes through a number of locations on its way to its final destination LE.  
     [0027] The present system utilizes an RF transponder  14  that is coupled to the item of inventory  12  and an environmental condition sensor  16  electrically coupled to the RF transponder  14 . The RF transponder  14  and environmental condition sensor  16  may be incorporated into or onto any package or packaging substrate, including paper, plastic, glass, metal, or hybrid packaging materials. As shown in FIGS.  12 - 14 , the RF transponder  14  includes an RF processor  18  and an antenna  20 . The antenna  20  may be onboard the RF processor (not shown), or, in a preferred embodiment shown in FIGS.  12 - 14 , may be a separate antenna  20  that is electrically coupled to the RF processor  18 . As discussed above, an item of inventory  12  may take the form of a paper roll, as shown in FIG. 12, a box, as shown in FIGS. 13 and 14, or another structure, as shown schematically in FIG. 15. The item of inventory  12  may be a large container, such as a crate used for carrying furniture or household goods, a carton carrying a plurality of boxed appliances, or individual boxes, or smaller individual boxes that are positioned in a larger box, the invention not being limited to a particular type of inventory.  
     [0028] As shown in the schematic representation in FIG. 15, the electronic components, which comprise the RF transponder  14  and sensor  16 , may be associated with an exterior  22  or internal  24  surface of the item of inventory  12 , may be positioned on a product  26  inside the item of inventory  12 , or may be floating  28  inside the item of inventory and not connected to anything. Furthermore, the electronic components may be positioned on primary, secondary, or other packages. For instance, where a plurality of smaller individual boxes are positioned in a larger box, the electronic components may be coupled to each of the smaller individual boxes, or to the larger box that houses the smaller boxes. In another example, such as a crate used to store and move household furniture and belongings, a particular item of inventory, such as a vase, may be susceptible to breakage caused by excessive shock. It may be desirable to position the electronic components on the vase, while it is unnecessary to position the electronic components on other items of inventory in the crate. Thus, the invention is not limited to a particular location or placement of the RF transponder  14  and sensor  16  on the item of inventory  12 .  
     [0029] In a preferred embodiment, as shown in FIGS. 12 and 13, the RF transponder  14  is positioned on an RF inlet  30  and the RF inlet  30  is secured to the item of inventory  12 . An RF inlet  30  is typically a thin substrate and the RF processor  18  and the antenna  20  of the RF transponder  14  are positioned on the substrate, as shown in FIGS. 12 and 13. The RF processor  18  and antenna  20  are electrically coupled to one another, either by direct contact or by capacitive coupling. The term “processor” refers generally to a computer that processes or stores information, such as a computer chip. The processor may include a semiconductor circuit having logic, memory, and RF circuitry. The computer chip may be a silicon-based chip, a polymer-based chip, or other chips that are known today or will be developed in the future. The RF processor  18  is preferably read/writable, so that information may be both stored in and read from the processor.  
     [0030] The environmental condition sensor  16  is in communication with the RF processor  18  and may be positioned on the RF inlet  30 , also shown in FIGS. 12 and 13. A power source, such as a battery  32 , may also be coupled to the RF processor  18  and sensor  16  and positioned on the inlet  30 , as shown in FIGS. 12 and 13. Alternatively, the invention also concerns electrical components that do not include a battery, such as the item of inventory  12  shown in FIG. 14, which includes an RF processor  18 , an antenna  20  and a sensor  16 .  
     [0031] The substrate of the RF inlet  30  may be a paper or polymeric material, such as polyester, among other known materials. In order to facilitate attachment of the RF inlet  30  to the item of inventory  12 , a pressure sensitive adhesive, or other attachment medium, may be positioned on one side of the substrate. Alternatively, the inlet  30  may be applied using glues, hot melts, water activated adhesives, or other adhering mediums.  
     [0032] The inlet  30  may be applied to the item of inventory  12  with an automatic application device, such as a label applicator, which can apply the inlet to an external  22  or internal surface  24  of the item of inventory  12  either after it has been assembled or prior to assembly. Alternatively, the inlet  30  may be positioned on a tag and placed inside the item of inventory in a floating manner as a “floating tag”  28 , or positioned on or inside the product(s)  26  in the item of inventory  26 , as shown schematically in FIG. 15. The inlet  30  may also be applied by hand or with an automated process. When the inlet  30  is positioned on a paper roll, as shown in FIG. 12, the inlet  30  is preferably positioned on the core  34  of the paper roll. In a preferred embodiment, the inlet  30  is positioned on an external surface of the core  34  and the stock of the paper roll is wrapped around the core  34  and covers the inlet  30 .  
     [0033] The antenna  20  of the RF transponder  14  may be an inductive or a capacitive antenna and the RF processor  18  may be an inductive or a capacitive processor. An inductive antenna  20  in the form of a loop with two ends is shown positioned on the inlet in FIGS.  12 - 14 . The RF processor  18  is in electrical contact with the ends of the loop. One end of the loop is coupled to one of the terminals of the RF processor  18  while the other end of the loop utilizes a bridging connector to couple to the other terminal of the RF processor  18 .  
     [0034] The environmental condition sensor  16  is in communication with the RF processor  18  and may be built directly into the radio frequency integrated circuit or connected to the RF circuit by a link. Alternatively, the sensor  16  can operate by wireless signal transfer, so that a physical link between the sensor  16  and processor  18  is not required. The sensor  16  may be active or passive, depending on the type of power source utilized. In a preferred embodiment, the sensor  16  is a MEMS (micro electromechanical system) sensor and is utilized to read environmental or other conditions, including physical and chemical properties, in the vicinity of the sensor. The sensor  16  may include at least one accelerometer. Other types of sensors are also contemplated for use with the invention. Examples of environmental properties that may be sensed by one or more sensors include temperature, pressure, humidity, head space gas detection and concentration (oxygen, carbon dioxide, nitrogen, etc.), vitamin concentration determination (vitamin depletion), microbiological agents ( E. Coli , broad spectrum—bacteria, molds), shock, vibration, strain, acoustics, angle, magnetic field, seismic properties, tilt, and noise, among other conditions. Multiple sensors may be utilized with a single or multiple RF processors. One type of passive sensor that may be utilized, for example, to read a temperature is manufactured by SCS of San Diego, Calif. A type of active sensor that may be utilized, for example, to record temperature data is manufactured by KSW of Germany. Other types of sensors may also be utilized.  
     [0035] The power source of the system is used for powering the RF transponder  14  and sensor  16 . The transponder  14  is often powered to sense an environmental condition using the environmental condition sensor  16 , without requiring a separate power source for the sensor. Certain types of sensors  16  also require independent power in order to operate the sensor, and the power needed by the sensor  16  may be provided by the same battery  32  that is utilized to power the processor  18  or by a separate battery. The power source may be provided by several separate devices, or a single device, depending upon such factors as whether the system is active, semi-active, or passive, as well as other factors.  
     [0036] Where a passive system is utilized, a battery  32  is not coupled to the transponder  14  and a power source powers the processor  18  and the sensor  16  to sense a condition when powered by the power source. With the passive system, the power source will typically be an RF reader  40  that sends a signal to the RF transponder  18  when it is time to record an environmental condition. The signal that is sent to the RF transponder  14  by the reader  40  is utilized to power the processor  18  and sensor  16  to record an environmental condition. The environmental condition may then be stored in the RF transponder  14  as environmental condition data and/or may be transmitted back to the RF reader  40 . Where a separate power source is necessary to power the sensor  16 , a battery  32  may be coupled to the sensor. When the RF reader  40  powers the transponder, the transponder  14  sends a signal to the sensor  16  to record an environmental condition. The environmental condition data is transmitted to the transponder  14  and/or the RF reader  40 .  
     [0037] With a semi-passive or active system, a battery  32  is electrically coupled to the RF processor  18  and is used to power the processor  18  and sensor  16  to record environmental condition data. With both systems, the battery  32  is used to power the transponder  14  and sensor  16  to record environmental condition data as a function of time. The transponder  14  may include a real time clocking mechanism, such as a timer, and be programmed to record data periodically, or when specified events occur. The environmental condition data is stored in the transponder  14 , where it may be accessed by the reader  40 .  
     [0038] With the semi-passive system, the environmental condition data is read from the transponder  14  whenever the transponder is interrogated by an RF reader  40 . The reader may then write over the existing data in the transponder  14 , or may leave the data in the transponder and add additional data. With an active system, the environmental condition data may be transmitted to an RF reader  40  without requiring the reader to interrogate the transponder  14 . An active system will generally require a more powerful battery than with a semi-passive system. A system is “active” in that the transponder  14  can perform its own tasks and order certain functions without requiring input from another device. The processor  18  in both the active and semi-passive systems can be timed by a timer so that readings occur at spaced intervals or on a continuous basis. With the active system, the processor  18  can also be timed with a timer to transmit data to the RF reader  40  at intervals, or on a continuous basis. Thus, with an active and a semi-passive system, environmental condition data may be recorded at a greater frequency than with a passive system, which requires that the transponder  14  be interrogated by a reader  40 . In summary, with the semi-passive system, two different power sources are necessary, while with the passive and active systems, only a single power source is required. Those of skill in the art will recognize that various signal conditioning circuitry may be required intermediate the sensor  16  and the RF processor  18  depending on the type of sensor utilized and the nature of the electrical outputs.  
     [0039] The system also preferably includes a log of location and environmental condition data and a reporting infrastructure. The log of location data  42  may be separate from or the same as the log of environmental condition data  44 , and both logs  42 ,  44  are preferably recorded as a function of time. In an alternative embodiment, location as a function of environmental condition is recorded, without requiring recordation of time.  
     [0040] The reporting infrastructure preferably includes at least one RF reader  40  and a central data processing computer  52  and station  54 . The central data processing computer  52  includes software and hardware, as known by those of skill in the art for transmitting data to a local area network (“LAN”) or a web page. The reporting infrastructure also preferably includes anti-collision software for use in accommodating multiple transponder and sensor reads at one time. The reporting infrastructure includes the software necessary to record and relay data measurements across all sectors of the distribution chain  10 . The data reporting software may handle single, multiple, and total sector coverage scenarios.  
     [0041] The at least one RF reader  40  of the reporting infrastructure is utilized to read information that is stored in the memory of the RF transponder  14 , including inventory information and data. The inventory information may include information that is stored in the transponder  14  before the item of inventory leaves the point of origin L 1 , and data that is added to the RF transponder  14  during the item&#39;s distribution along the distribution chain  10 . The data may include environmental condition data and location data. The environmental condition data is data that is recorded from the environmental condition sensor  16  and the location data is data that is input to the RF transponder  14  during the distribution process. The location data  42  is typically input by a user using a reader or other transmitter. The reporting infrastructure may be customized to the particular application and type of environmental conditions being recorded.  
     [0042] The log of location data  42  and the log of environmental condition data  44  may be transmitted to the reporting infrastructure in a number of different ways. In one embodiment, the logs of data  42 ,  44  may be stored in the RF transponder  14  and transmitted to the reporting infrastructure when read by a reader  40  and instructed by the programming of the reporting infrastructure to transmit to the computer processor  52 . In an alternative embodiment, the logs of data  42 ,  44  may be directly transmitted to the reporting infrastructure when the data is read by the reader  40 , without storing any of the data in the RF transponder  14  memory. In yet a further embodiment, the logs of data may be manually recorded in a handwritten list. The manually recorded data  42 ,  44  is transferred to the reporting infrastructure by entering the data into the computer  52  using a data entry device. The data that is stored in the RF transponder  14  is preferably transmitted to the reporting infrastructure using an RF reader  40  that reads the RF transponder  14  and transmits the data to the reporting infrastructure using software programmed into the RF reader  40  and the computer processor  52  of the reporting infrastructure.  
     [0043] The reporting infrastructure may also include a data report  56  that is generated by the software stored in the computer processor  52 . The data report  56  preferably includes a record of the environmental condition as a function of location. The data report  56  may also include instructions to the user as to whether any detrimental environmental factors were encountered during the distribution process. One type of data report that may be generated is a graph of the environmental condition as a function of location and time, as shown in FIGS. 2, 5, and  8 .  
     [0044] The reporting infrastructure preferably also includes software for converting the sensor data that is generated by the environmental condition sensor  16  into digital data, processing the digital data, and analyzing the processed data to determine whether the sensed data exceeds any limits that are associated with the item of inventory  12 . For example, where an item of inventory  12  is sensitive to a particular environmental condition, such as temperature or shock, a threshold limit  58  may be programmed into the reporting infrastructure computer programming so that the software can determine whether to signal the user that a detrimental event has occurred. The threshold limit  58  may be set as an absolute limit, or may be calculated based upon time at a certain level. For instance, the limit for a parameter such as shock may be set at an absolute level, which, when surpassed, will result in a signal to the user. With a parameter such as temperature or humidity, the limit may be determined based upon the product exceeding a certain level for a given period of time, or exceeding an absolute limit. Both types of limits may be incorporated, if so desired.  
     [0045] RF readers  40  may be positioned throughout the distribution chain  10 . For instance, readers  40  may be positioned at the processor&#39;s packaging station(s), warehouse storage, transit vehicles, cooler boxes, restaurant holding coolers, etc. Areas of greatest importance are business transfer points where the responsibility of the goods exchanges hands. Alternatively, with an active or semi-passive system, a reader  40  may only be required at the final destination LE, where the environmental condition data  44  may be read and transferred to the reporting infrastructure. A variety of distribution scenarios are discussed below, in connection with FIGS.  1 - 11 . The RF reader  40  may be a hand held device or a stationary device.  
     [0046] FIGS.  1 - 6  depict a distribution chain  10  where the location data  42  is recorded manually. The data  42  may be recorded as a list on a piece of paper  48 , or may be recorded electronically in an electronic device, such as a hand held computer, or input through a data entry device, such as a keyboard, to the computer processor  52  of the reporting infrastructure. Location data  42  is preferably recorded as a function of time whenever an item of inventory  12  leaves the custody of a custodian. For example, in FIG. 1, the log of location data  42  is recorded when the item of inventory  12  leaves L 1 , leaves a transport vehicle (transport  1 ) that transports the item of inventory from L 1  to L 2 , leaves L 2 , leaves a transport vehicle (transport  2 ) that transports the item of inventory from L 2  to L 3 , leaves L 3 , and leaves a transport vehicle (transport  3 ) that transports the item of inventory from L 3  to LE. Custody may be presumed to exist in the next custodian when the item of inventory  12  leaves the custody of the prior custodian.  
     [0047] In FIG. 1, the log of location data  42  is manually recorded on a list  48  that is generated while the item of inventory  12  travels along the distribution chain  10 . The list may be included with packing slips for the item of inventory  12  and stored in a pouch that is attached to the side of the item of inventory  12 , among other ways for maintaining a list. FIG. 1 represents a semi-passive system, where environmental condition data is periodically and regularly transmitted to the RF transponder  14  and stored in the transponder. An RF reader  40  is shown positioned at each location L 1 , L 2 , L 3 , LE and powers the transponder to read the data stored in the RF transponder  40 . Each time the data is read by the reader  40 , it is transmitted to the computer processor  52 . While the reader  40  is shown positioned at each location, readers may alternatively be positioned at numerous points in each location. In addition, readers  40  may be utilized during transport. In this distribution chain  10 , the read data from the RF transponder  14  is transmitted immediately to the computer processor  52 . All of the sensed data may be recorded in the RF transponder  14  if memory size permits. Alternatively, sensed data may be erased from the RF transponder each time the data is read by the RF reader  40  in order to free up more memory in the transponder  14 .  
     [0048]FIG. 2 shows an illustrative graph  56  of temperature as a function of location and time for an item of inventory  12  as it travels along a distribution chain  10 , like that of FIG. 1. This graph may be generated by the software in the reporting infrastructure once the item of inventory  12  has reached its final destination LE and the log of location data  42  as a function of time has been input into the computer processor  52 . A similar but shortened version of the graph  56  may also be generated before the item of inventory  12  reaches the final destination LE because environmental condition data  44  is reported to the computer processor  52  whenever the RF transponder is read by the RF reader  40  The graph  56  shows a threshold limit  58  for temperature, shown by the dashed line, and represents an example of the conditions a refrigerated item of inventory  12  may encounter during the distribution process. During time period A, the product leaves L 1  and encounters slight temperature fluctuations during transport  1 . During time period B, the product enters L 2  and is left unrefrigerated for the duration of time that it is in L 2  such that the temperature of the item of inventory  12  rises above the threshold limit  58 . During time period C, when the item of inventory leaves L 2 , it is refrigerated during transport  2  and returns to its original temperature by the time it reaches L 3 . Time periods D and E are uneventful and the product remains at approximately the same temperature until it arrives at the final destination LE. As is evident, the item of inventory  12  is likely ruined because it exceeded the threshold limit  58  for temperature. The data report  56  from the reporting software can alert the user as to when the detrimental event occurred and determine the custodian who caused the detrimental event. In this manner, the party that damaged the goods can be held accountable for destroying the product.  
     [0049]FIG. 3 shows another scenario where the log of location data  42  is manually recorded and input into the computer processor  52  of the reporting infrastructure at the final destination LE. The RF transponder  14  and sensor  16  are part of a semi-passive system where the transponder  14  and sensor  16  are powered by a battery  32  so that environmental data is recorded periodically over time and stored in the RF transponder  14 . In this embodiment, however, only one RF reader  40  is utilized and is positioned at the final destination LE. The RF reader  40  reads the environmental condition data stored in the transponder  14  and transmits the data to the computer processor  52 , where the data may be processed.  
     [0050]FIG. 4 shows another distribution chain  10  where the log of location data  42  is manually recorded as a list  48  of data. The location data is recorded and transmitted at each transfer point to the reporting infrastructure, either by input into the computer processor  52  directly by a data entry device, through a web page, or via other known input techniques. In this embodiment, the RF transponder  14  and sensor  16  are part of a passive system, where the transponder  14  and sensor  16  are not powered by a battery  20 . The power for sensing a condition is provided by an RF reader  40 , which powers the RF transponder  14  to read an environmental condition using the sensor  16 . In this embodiment, the environmental condition data  44  may be both stored in the RF transponder  14  and automatically transferred to the computer processor  52  for use in the reporting infrastructure. This embodiment is conducive to generating a report  56  periodically, as the item of inventory  12  travels along the distribution chain  10 . In an alternative embodiment, the sensed data is transmitted to the reporting infrastructure at the time of the reading, but is not stored in the RF transponder  14 .  
     [0051]FIG. 5 is an illustrative graph  56  of temperature as a function of location and time for an item of inventory  12  as it travels along a distribution chain  10 , like that in FIG. 4. This graph  56  may be generated by the software in the reporting infrastructure once the item of inventory  12  has reached its final destination LE and the log of location data  42  as a function of time has been input into the computer processor  52 . A similar, but shortened version of the graph  56  may also be generated before the item of inventory  12  reaches the final destination LE because environmental condition data is  44  reported to the computer processor  52  whenever the RF transponder  14  is read by the RF reader  40 . Like FIG. 2, the graph  56  shows a threshold limit  58  for temperature, represented by the dashed line. During time period A, the product leaves L 1  and encounters a slight temperature rise during transport  1  because the refrigeration unit is set at a higher temperature on transport  1  than that in L 1 . During time period B, the product enters L 2  and the temperature of the product decreases because the refrigeration unit at L 2  is set at a lower temperature than that of transport  1 . Temperature remains nearly constant during time period C and D until the item of inventory leaves L  3  and is positioned on transport  3 . The item of inventory is not properly refrigerated on transport  3 . As a result the temperature increases above a threshold level  58  and remains at this level until the temperature is read at LE. As is evident, the item of inventory  12  is likely destroyed because it exceeded the threshold limit  58 . The data report  56  from the reporting software can alert the user as to when the detrimental event occurred and identify the custodian who caused the detrimental event.  
     [0052]FIG. 6 illustrates another embodiment where the location data  42  is manually recorded, similar to that discussed above in connection with FIGS. 1 and 3. In this embodiment, the RF transponder  14  and sensor  16  are part of a passive system, where the transponder  14  and sensor  16  are not powered by a battery  20 . The power for sensing a condition is provided by an RF reader  40 , which powers the RF transponder  14  to read an environmental condition using the sensor  16 . Readers  40  are positioned at numerous locations throughout the distribution chain  10 . It is preferred that a reading is taken at least when the item of inventory  12  enters a new location and when the item leaves a location. It is also desirable to take a reading using the reader  40  at various intervals while the item of inventory  12  is stored at a particular location L 1 , L 2 , L 3 , LE. With this embodiment, each time that the reader  40  powers the RF transponder  14 , the environmental condition data is stored in the RF transponder  14  for later use. Then, at the final destination LE, the RF reader  40  powers the RF transponder  14  for the final environmental condition reading, and also reads all the data stored in the RF transponder  14  and communicates the data to the computer processor  52 . In this embodiment, it is not necessary that the reader  40 , at the initial L 1  and intermediate locations L 2 , L 3 , communicate with the computer processor  52 , since all the environmental condition data  44  is stored in the RF transponder  14 . This embodiment is conducive to generating a report  56  of the environmental condition after the item of inventory  12  has arrived at the final destination LE.  
     [0053]FIG. 7 is an embodiment of the distribution chain  10  where the location data  42  is provided by an RF reader  40  each time the reader  40  communicates with the RF transponder  14 . The location data  42  as a function of time is input to the reporting infrastructure electronically, rather than generating a manual, hand-written list  48 . In this embodiment, a reader  40  is shown positioned at both the exit to each location and the entrance to each location. In an alternative embodiment, the reader  40  may be positioned in either the exit or the entrance of each location, if desired to reduce the number of readers  40  and/or the number of readings. In FIG. 7, location data  42  is stored in the reader  40  so that when the reader  40  communicates with the RF transponder  14 , it can communicate both information regarding the item of inventory  12  that is stored in the transponder  14  and attach the location information to the inventory information by forwarding the information to the reporting infrastructure. The location data  42  is not stored in the RF transponder  14 , although later embodiments do store such data in the transponder  14 . In this embodiment, the RF transponder  14  and sensor  20  are semi-passive and environmental condition data  44  is stored regularly and periodically. Each time a reader  40  reads the RF transponder  14 , the environmental condition data  44  is transmitted to the reporting infrastructure. In this way, a partial report of environmental condition versus location may be generated, if so desired.  
     [0054]FIG. 7 also depicts an embodiment of the distribution chain  10  where the location data  42  is electronically transmitted by a reader  40  that has been programmed with location data  42  and the RF transponder  14  and sensor  16  are semi-passive and record environmental condition data  44  regularly and periodically. In this embodiment, represented by both the solid line and the dashed line connecting the reader  40  at LE to the computer processor  52 , the location data  42  is recorded for the particular item of inventory  12  and transmitted to the reporting infrastructure each time that the reader  40  communicates with an RF transponder  14 . Data relating to the item of inventory  12  that is stored on the RF transponder  14  is attached to the location data  42  provided by the reader  40  so that the item of inventory  12  is recognized. The environmental condition data  44  is stored in the RF transponder  14  and is read by a reader  40  at the final destination LE, as represented by the dashed line. In this manner, all the environmental condition data  44  is stored in the RF transponder  14  and released once the final destination LE is reached. This embodiment is not conducive to periodic environmental condition reports.  
     [0055]FIG. 8 is a graph  56  showing an illustrative example of shock as a function of location and time for an item of inventory  12  as it travels along a distribution chain  10 , like that of FIG. 7. This graph  56  may be generated by the software in the reporting infrastructure once the item of inventory has reached its final destination LE and the log of location data  42  and log of environmental condition data  44  has been transmitted to the computer processor  52 . The graph  56  shows a threshold limit  58  for shock, represented by the dashed line. During time period A, the product leaves L 1  and enters transport  1 . The item of inventory  12  is transported to L 2  and encounters slight movement during transport. During time period B, the product enters L 2  and is moved to a location in the warehouse (thus experiencing some shock while being moved) and then rests in the warehouse until it enters transport  2 . During time period C, the item of inventory encounters minor shock waves during initial transport and is then dropped as the item of inventory is removed from transport  2 . As a result, the shock reading escalates above the threshold level  58 , possibly resulting in damage to the item of inventory  12 . During time period D, the product rests at L 3  and during time period E, the item of inventory  12  undergoes transport in transport  3  to LE. During transport, the item of inventory  12  encounters slight shock levels. As is evident, the item of inventory may have been damaged while associated with transport  2  because the threshold level of shock was exceeded when the item of inventory  12  was dropped. The data report  56  from the reporting software can alert the user as to when the detrimental event occurred and identify the custodian who caused the detrimental event.  
     [0056]FIG. 9 represents an alternative embodiment of a distribution chain  10 , where the location data  42  is provided by a reader  40  positioned at each location L 1 , L 2 , L 3 , LE and the RF transponder  14  and sensor  16  operate on a passive system. Like the prior embodiments of FIG. 7, location data  42  is stored in the reader  40  at each location L 1 , L 2 , L 3 , LE and is transmitted to the computer processor  52  of the system each time the RF transponder  14  is read. The system takes the information stored in the RF transponder  14  relating to identification of the item of inventory  12  and transmits the location and time for each item of inventory  12  during each reading to the computer processor  52 . With respect to environmental condition, a reading of the environmental condition data  44  is only obtained when the reader  40  powers the RF transponder  14  to take a reading of the condition. Thus, it is desirable to read/power the RF transponder  14  at regular intervals in order to more fully chronicle the environmental condition of the item of inventory  12  as a function of time. Each time the reader  40  powers the transponder  14  to sense the environmental condition, the environmental condition is stored in the RF transponder  14  and transmitted to the reporting infrastructure. The location  42  and environmental condition data  44  are processed by the programming of the reporting infrastructure to correlate environmental condition with location. With this embodiment, it is possible to obtain an interim report of location and environmental condition data, if so desired. In FIG. 9, a single reader  40  for each reading location is utilized to handle both location and environmental condition data. However, it should be noted that more than one reader  40  can be used, one of which transmits location information and the other of which reads/powers the RF transponder  14 .  
     [0057]FIG. 9 also depicts another embodiment of the distribution claim 10, where location data is transmitted to the RF transponder  14  by the reader  40  at each location, similar to that discussed for the first embodiment of FIG. 9, and an RF transponder  14  and sensor  16  that are passive. A reader  40  is used to power and read the RF transponder  14 . Each time that a reader  40  powers the RF transponder  14 , environmental condition data  44  is stored in the RF transponder  14 . When the item of inventory  12  reaches the final destination LE, the RF transponder  14  will have stored all the environmental condition data  44  that resulted from powering of the transponder  14 . The RF reader  40  at the final destination LE reads and transmits the data  44  to the computer processor  52 , where the environmental condition data  44  is correlated with location data  42 .  
     [0058]FIG. 10 depicts yet another embodiment of the distribution chain  10  for an item of inventory  12 . In this embodiment, the RF transponder  14  and sensor  16  operate on a semi-passive system so that environmental condition data  44  is recorded at regular intervals, as governed by a timer that is coupled to the RF transponder  14 . The RF reader  40  holds location data  42  and communicates the location data to the RF transponder  14 , which then stores the location data  42  in the transponder  14 . Environmental condition data  44  is also stored in the transponder  14 . Each time the reader  40  reads the transponder, the location and environmental condition data are transmitted to the computer processor  52 . In this way, a duplicate log of location and environmental condition data is generated.  
     [0059]FIG. 10 also depicts an alternative embodiment of the distribution path for an item of inventory  12  where location data  42  is transmitted by the reader  40 , and the RF transponder  14  and sensor  16  are part of a semi-passive system. Environmental condition data  44  is recorded at regular intervals and stored in the RF transponder  14 . In addition, the reader  40  is utilized at each location to transmit location information to the RF transponder  14 . Thus, a complete log of location  42  and environmental condition data  44  is stored in the RF transponder  14 . The reader  40  at the final destination LE, represented by the dashed line in FIG. 10, reads all the information stored in the RF transponder  14 , including location  42  and environmental condition  44  data, and transmits the data to the reporting infrastructure.  
     [0060] In FIG. 7, the readers  40  are shown as communicating with the RF transponder  14  whenever the item of inventory  12  is about to leave a location or transport. While this technique is an effective way to monitor location, and requires only one communication of location information per location, it is also possible to communicate location information when an item of inventory  12  enters or leaves a location (shown in FIG. 10) or at intermediate points within a particular location (shown in FIGS. 9 and 11), the invention not being limited to communicating location at a particular point or at a single point.  
     [0061]FIGS. 9 and 11 represent distribution chains  10  where the RF transponder  14  and sensor  16  are part of a passive system. A reader  40  is utilized to power the transponder  14  to record an environmental condition  44  and the recorded environmental condition is stored in the RF transponder  14 . In addition, a reader  40  is utilized to transmit location data  42  and the location data  42  is stored in the RF transponder  14  each time that the RF transponder  14  is read. In FIG. 9, each time that a reader  40  powers a transponder  14  and the sensor  16  senses an environmental condition, the environmental condition may be both transmitted to the reporting infrastructure and stored in the RF transponder  14 . At the final destination LE, any stored location and environmental condition data  42 ,  44  is transmitted to the reporting infrastructure for further processing. In FIG. 11, the RF transponder  14  records both location and environmental condition data  42 ,  44  each time the transponder is powered by a reader  40 . This data is stored in the transponder  14  until the final destination LE, where a reader  40  reads the information stored in the transponder  14  and transmits the data to the reporting infrastructure at one time.  
     [0062] A variety of commercially available inlets and processors are contemplated for use with the claimed invention. For example, inlet suppliers include Poly Flex Circuits, Cross Technologies, and Global ID. Processor suppliers include Philips Semiconductor, Temic, and E.M. The preferred inlets are low profile in order to avoid marking the paper on the roll.  
     [0063] It should be noted that RF processor  18  and antenna  20  combinations other than those discussed above or shown in the figures may be utilized with the invention. For instance, while a preferred embodiment includes positioning the RF processor  18 , sensor  16 , and battery  32  on an inlet  30 , these components may, alternatively, be deposited directly on the surface of the item of inventory  12  without the need for an inlet, as shown in FIG. 14. Furthermore, while the antenna  20  is generally positioned on the inlet  30 , the antenna  20  may be positioned on the surface of the item of inventory  12  instead of on the inlet  30 . For example, the antenna  20  could be conductive ink that is printed onto the surface of the item of inventory  12 . When the antenna  20  is positioned directly on the surface of the item of inventory  12 , the RF processor  18 , which is electrically coupled to the antenna  20 , is positioned on a substrate or may be independent of a substrate. The antenna  20  may be positioned on the surface of the item of inventory  12  utilizing any known technique, such as printing a conductive ink, sputter coating a conductive material, and hot foil stamping, among other known antenna depositing techniques. Furthermore, the RF processor  18  may be coupled to the antenna  20  by leads, connectors, interposers, or other known techniques for coupling an RF processor to an antenna.  
     [0064] While various features of the claimed invention are presented above, it should be understood that the features may be used singly or in any combination thereof. Therefore, the claimed invention is not to be limited to only the specific embodiments depicted herein.  
     [0065] Further, it should be understood that variations and modifications may occur to those skilled in the art to which the claimed invention pertains. The embodiments described herein are exemplary of the claimed invention. The disclosure may enable those skilled in the art to make and use embodiments having alternative elements that likewise correspond to the elements of the invention recited in the claims. The intended scope of the invention may thus include other embodiments that do not differ or that insubstantially differ from the literal language of the claims. The scope of the present invention is accordingly defined as set forth in the appended claims.