Method and system for inventory monitoring
Contents
1. 101 235 462 01 462 44 46245 PSC Tne no dute 235 462 46 385 Continued See application file for complete search history n 5 rimary Xaminer JO Lweel Jr 56 References Cited 74 Attorney Agent or Firm Stoel Rives LLP U S PATENT DOCUMENTS 5 640 002 A 6 1997 Ruppert et al 235 462 46 5 659 167 A 8 1997 Wang et al 235 472 6 170 748 B1 1 2001 Hashetal 340 572 1 6 292 525 Bl 9 2001 Tam qua asa tete 378 4 6 318 636 B1 11 2001 Reynolds et al 235 472 01 6 456 239 B1 9 2002 Werb et al 342 463 6 607 134 B1 8 2003 Bardetal 235 462 46 6 687 460 B2 2 2004 Muller 396 534 6 745 027 B2 6 2004 Twitchell Jr 455 422 1 6 758 403 B1 7 2004 Keysetal 235 462 46 6 895 196 B2 5 2005 Uchizono et al 399 75 7 042 358 B2 5 2006 Moore 340 572 1 7 063 256 B2 6 2006 Anderson etal 235 385 57 ABSTRACT A system and method for providing operational feedback of systems using electronic tags such as radio frequency identi fication RFID tags for inventory monitoring including ref erence tags that provide feedback to check if all inventory items have been identified In one configuration the RFID reader actuates by a single trigger pull with the reader con tinuing to read multiple RFID tags in the read zone until a terminating event occurs 30 Claims 5 Drawing2. as the user selects input by using the touch display screen 13 Alternately the user may input data through the keypad section 14 Within a particular mode of operation the user may activate a particu lar read operation by actuating the pistol trigger 19 located on the front of the handle 18 The user may also activate a particular read operation by using a scan key trigger 25 on the keyboard 14 or another virtual switch on the touch screen 13 The combination reader 10 sends out an interrogation sig nal during a read operation in response to an appropriate actuation such as activating pistol trigger 19 or scan key trigger 25 Upon receipt of the interrogation signal an RFID tag whether it is a passive tag or an active tag may respond by sending out a return signal containing the tag data The combination reader 10 then senses the return signal and pro cesses the signal to obtain the data An RFID read operation in a handheld device may be defined by actuation of a switch e g trigger 19 and a single read command sent to the combination reader 10 to read all the tags within a radio frequency RF field The combination reader 10 may read multiple tags within a single read opera tion or tag inventory operation Each of the tags interrogated US 7 394 358 B2 3 in a given read operation may be read sequentially according to a suitable protocol such as query response protocol or air interface protocol AIP There are several diff
3. end of the overall read opera tion In one embodiment the reader responds with an audible beep tone each time a new RFID tag and or reference tag is read and reported The user may also be notified by actuation ofan LED 17 such as by short flashing green each time a new tag is read and or long flashing green each time a reference tag is read The repetitive beeps and or lighting of the LED indi cator 17 provide information to the operator ofthe progress of the read operation For example when there are multiple tags intended to be read during the operation a plurality of tags is read quickly at the beginning of the operation As more and more tags and reference tags are read fewer unread new tags remain to be read wherein the frequency of the beeps indicating new tags being read slows down Eventually the reader notifies the user that there are no further new tags to be read when a beep has not been heard within a reasonable time frame The user may then terminate the operation by releasing the trigger 19 The trigger holding operation enables the user to move the read field such as by a painting motion that is sweeping a field systematically by moving the reader across a shelf of items to provide the combination reader 10 with the opportunity to read each of the items and reference tags from an optimal orientation 0 an 5 20 40 45 60 6 In another termination criteria software may be used to examine an interm
4. to indicate that a complete sweep of the inventory area has been completed Once each of the 50 RFID tags are read as indicated inferred by having read all of the reference tags the operation may be terminated The reference tag information assists the user with ensuring com plete coverage ofthe volume to be read during the attempt to read all of the expected item tags In a subset of this section the pallet or inventory area may include its own RFID tag with the RFID tag providing information as to how many items are included on the pallet or in the inventory area Alternately the information may be stored in a look up table accessible to the reader terminal There are other mechanisms to assist with selecting a read termination criterion They include but are not limited to reading the expected number of reference tags input field filling an external controller a termination delay timer a new tag read timer and a minimum tag count The RFID data being collected may be used to fill out certain input fields such as on an inventory check list Once all the input fields on the inven tory check list are filled the read operation may be terminated The read operation may be monitored using a network and RFID read data may be reported to a host computer using the network The RFID read data may then originate from the host computer using the network The reader may have a delay in termination after releasing the trigger 19 In addition the
5. used in several ways For example a portable reader may be programmed with the relative locations of the various reference tags When begin ning an interrogation or an inventory sweep a simple graphi cal representation of the reference tag locations may be dis played on the touch display screen 13 wherein the reference tags are automatically deleted or changed color for example from red to green after the particular reference tag is read thus indicating to the operator which portions of the volume remain to be swept FIG 9 illustrates such a system and is described in further detail below Alternately the reference tag data may be included in inventory data sent to terminal 12 for further processing such as data quality monitoring The reference tag data may also be sent to the remote base station or other systems for further use The other use may include checking for the complete coverage of different areas that may be scanned for tags In a second preferred embodiment the RFID read opera tionis extended beyond a single read attempt by continuing to perform multiple reads or multiple interrogation sequences are undertaken until meeting a particular terminating criteria One such method may be directed to a handheld reader including the steps of 1 pointing a handheld RFID reader toward a read area 2 actuating a trigger on the handheld RFID reader to commence reading RFID tags by the substeps of a performing a first read operati
6. P U S Patent Jul 1 2008 L Decoding Properties Configure Settings Audio e gt e 2004 PSC Inc Sheet 4 of 5 US 7 394 358 B2 Configure Saettings eI Report Settings Report Frequency 1 Tag Read Class 0 Tags Read Class 1 Tags psa po sm 2004 PSC Inc Lus Decoding Properties 2 Configure Settings Read Limits Total Read Timeout i 122 New Tag Timeout Minimum Tag Count ee 2004 PSC Inc U S Patent Jul 1 2008 Sheet 5 of 5 US 7 394 358 B2 132b 136 135 133 132 US 7 394 358 B2 1 METHOD AND SYSTEM FOR INVENTORY MONITORING COPYRIGHT NOTICE A portion of the disclosure of this patent document con tains material that is subject to copyright protection The copyright owner has no objection to the facsimile reproduc tion by anyone of the patent document or the patent disclo sure as it appears in the Patent and Trademark Office patent file or records but otherwise reserves all copyright rights whatsoever per 37 CFR 1 71 BACKGROUND The field of the present disclosure relates to operating methods and techniques for systems employing electronic identification tags such as radio frequency identification RFID tags In particular methods and apparatus are described herein for improving and facilitating operation of electronic tag and RFID reading systems RFID interrogators use electromagnetic energy as a medium through which t
7. Sheets 2 COMMUNICATIONS RADIO DISPLAY 22 US 7 394 358 B2 Page2 OTHER PUBLICATIONS Falcon 5500 RFID Mobile Hybrid Computer user manual Adden dum R44 2494 Rev X3 PSC Inc no date Falcon 5500 RFID Mobile Hybrid Computer user manual Adden dum R44 2494 Rev X4 PSC Inc no date Falcon 5500 RFID Mobile Hybrid Computer user manual Adden dum R44 2494 Rev A PSC Inc about Aug 2006 Office Action dated Dec 20 2007 for U S Appl No 11 084 072 of Robert Hougen application published as US2006 0208859 cited by examiner U S Patent Jul 1 2008 Sheet 1 of 5 US 7 394 358 B2 Decoding Properties ok x Configure Settings el Triggers Pistol Trigger Scan Key Disable 44 42 Bar Code Image RFID BpmIe pm Za 2004 PSC Inc U S Patent Jul 1 2008 Sheet 2 of 5 US 7 394 358 B2 13 10 KEYBOARD DISPLAY t 4 2 11 15 AUDIO BARCODE BEEPER SCANNER PROCESSING CORE INTERROGATOR 17 PaL 20 ANTENNA COMMUNICATIONS ee RADIO i U S Patent Jul 1 2008 Sheet 3 of 5 US 7 394 358 B2 HARDWARE SOFTWARE 50 TRIGGER PRESS FUNCTION CALL 5 54 BEGIN RFID TAG INVENTORY OPERATION I 5 56 INSTRUCT RFID INTERROGATOR TO INVENTORY TAGS 58 INDICATE NEW NEW TAGS YES TAG DATA READ FOUND NO 62 ALL TAGS NO 64 OPERATION YES TIMEOUT 60 66 NEW TAG DATA YES YES uen END RFID TAG YES INVENTORY INDICATION O STO
8. US007394358B2 az United States Patent 10 Patent No US 7 394 358 B2 Cherry 45 Date of Patent Jul 1 2008 54 METHOD AND SYSTEM FOR INVENTORY 7 195 169 B2 3 2007 Bhatia etal 235 462 46 MONITORING 7 199 716 B2 4 2007 Shanks et al 340 572 1 75 1 B OR 7 221 668 B2 5 2007 Twitchell Jr 370 338 nventor Craig D Cherry Eugene OR US 7 243 849 B2 7 2007 Lapstun et al 235 462 45 73 Assignee Datalogic Scanning Inc Eugene OR 2001 0008390 AI 7 2001 Berquist et al 340 10 31 US 2004 0076232 Al 4 2004 Akiyama etal 375 240 08 2004 0105024 6 2004 Takahashi 348 333 01 Notice Subject to any disclaimer the term of this 2004 0118916 Al 62004 235 383 Pn d um e under 35 2004 0217774 Al 11 2004 Choe 326 30 Sod y T9 2005 0212676 Al 9 2005 Steinberg 340 572 8 21 Appl No 11 230 365 2006 0208859 AI 9 2006 Hougen et al 340 10 1 2006 0208890 A1 9 2006 Ehrman etal 340 572 1 22 Filed Sep 19 2005 2007 0095911 Al 5 2007 Shimura etal 235 462 46 65 Prior Publication Data US 2007 0063817 A1 Mar 22 2007 OTHER PUBLICATIONS 51 Int CI G08B 26 00 2006 01 U S Appl No L08072 filed Mar 16 2005 to Robert W Hougen 52 US Cl ss 340 505 340 572 1 235 462 46 a Eia and MEA duos us user manua endum ev C PM T
9. ator may be a separate high intensity LED 17a on the top of the housing as shown in FIG 1 or may be a suitable indicator appearing on the display 13 The combination reader 10 is a multiple data input device having a barcode scanner or imaging reader 15 an RFID interrogator 20 a display 13 pistol trigger 19 and scan key trigger 25 The RFID antenna 22 is attached to the interroga tor The system communicates to a computer or another host via communications 16 which is preferably a wireless con nection The interrogator 20 communicates through the antenna 22 to read inventory RFID tags and reference tags The display 13 provides a versatile and convenient control interface for the combination reader 10 In a preferred opera tion the user may select which one of the reading mecha nisms is to be used In a preferred configuration the combi nation reader 10 may have two triggers There is the pistol trigger 19 on a handle 18 and the scan key trigger on the keyboard 14 of the terminal 12 Additional triggers may be providedonthe keyboard 14 in the form of virtual key triggers displayed on the touch screen 13 or by electromechanical means e g accelerometer switch A user may activate a virtual key trigger to begin reading inventory RFID tags and reference tags or independently read the reference tags Each ofthe trigger functions may be set via software programming In one operating method the terminal functions in a Microsoft Windows M e
10. combination reader 10 may automatically continue to read and analyze whether new tags have been read A timeout timer restarts each time a new tag and or reference tag is detected As long as a new tag is detected it may be desirable to continue searching for and reading additionaltags Accord ing to a preferred termination criteria if a new tag 1s not read within a specified time then the read operation is terminated Alternately termination criteria may include a minimum number of attempts to read tags during the inventory opera tion Each of the timeout times shut off delay or other system variables may be programmable variables The program mable variables may be selected by the user defaults in the system selected by the host computer over the network or may be actively varied by the system These variables may be selected by a given criteria as a result ofa prior read operation or other inputs The sweep sentinel scheme allows the user to move the combination reader 10 in a single read operation to read all tags including the reference tags such as on a shelf FIG 4 illustrates a preferred orientation for aiming the combination reader 10 and an RFID tag 32 such that the RFID interrogator 20 points directly at the tag 32 providing a read field encom passing the tag As illustrated in FIG 9 the read field may include inventory RFID tags 133 134 135 and 136 and further include reference tags 132a 1325 132c 132d 132e and 132
11. ediate report of tag data received and following a given criteria decide to terminate the read opera tion One such criteria may comprise searching for a specific tagged item and capturing data of the inventoried goods in addition to data from the reference tags If the reference tag data is present the inventory data is deemed complete and the read operation is terminated Moreover the reference tag data may be used in several ways For example the combination reader 10 may be programmed to display a graphical repre sentation of the reference tags location when beginning the inventory sweep As the reference tags are identified each identified reference tag is deleted after it is read until all the reference tags are read which then terminates the read opera tion FIG 2 illustrates a schematic of the components of the combined reader 10 of FIG 1 The combined reader includes a processing core 11 which may include the microprocessor within the terminal 12 Connected to the processor core 11 are the keyboard 14 that provides for information input and the display 13 The display 13 may display information and also act as a touch screen for inputting commands or data into the system Under the control of the processing core 11 the sys tem may include one or more indicators such as audio beeper 24 or an indicator light 17 The indicator may comprise a light emitting diode LED or other suitable visible light indicator Alternately the indic
12. er all the item tags have been read While there has been illustrated and described a disclosure with reference to certain embodiments it will be appreciated that numerous changes and modifications are likely to occur to those skilled in the art It is intended in the appended claims to cover all those changes and modifications that fall within the spirit and scope of this disclosure and should therefore be determined only by the following claims and their equiva lents What is claimed is 1 A method of RFID reading comprising the steps of pointing a handheld RFID reader toward a read area con taining RFID tags including both item tags and reference tags wherein an item tag is disposed on an item and includes identification data corresponding to that item wherein a reference tag is positioned at a location in the read area such that when read by the RFID reader sig nifies that the RFID reader has effectively read a region proximate that location of the read area actuating a trigger on said handheld RFID reader to com mence reading the RFID tags performing a first read operation comprising interrogating and sensing with said RFID reader at least one RFID tag in said read area 2 A method according to claim 1 further comprising continuing with a subsequent read operation comprising interrogating and reading at least one tag in said read area said RFID reader discontinuing subsequent read operation once a termination criteria
13. f spaced about a shelf area 130 The combination reader 10 may then sweep the shelf area 130 checking for a complete sweep using the reference tags When the inventory is taken at the shelf area 130 the combination reader 10 captures data from the reference tags 132a 1325 132c 1324 US 7 394 358 B2 5 132e and 132 in addition to the data from the tags 133 134 135 and 136 on goods that are being inventoried If the refer ence tag data is present the reader display 13 may indicate that all ofthe inventory data is complete with a single sweep If some reference tags were not read the user may attempt a second sweep of the shelf area 130 When beginning the inventory sweep by passing the combination reader 10 over the shelfarea a graphical representation 132a 1326 132c 132d 132e 132 of location may be shown on the display 13 of the reader As each reference tag is read by the RFID interrogator 20 each reference tag may be automatically or manually deleted from the display 13 Alternately an unread tag may be indicated by a first representation such as by a first color e g red or a clear box 132a 132d and the tags that have been read may be indicated by a second color e g green or by a blacked out or cross hatched box 1326 132c 132e 1327 Thus the display 13 notifies the user as to how many of the reference tags have been read as well as the location on the shelf where reference tag s have not been read allowi
14. g to claim 23 further comprising confirming that the electronic tag reader has successfully covered the read area by determining that the electronic tag reader has read a given number of the reference tags 25 A method according to claim 23 further comprising providing a display on the electronic tag reader with a graphical representation of locations of reference tags that have not been read 26 A method according to claim 25 further comprising once a reference tag has been read removing the graphical representation corresponding to that reference tag from the display 27 A method according to claim 25 further comprising once a reference tag has been read changing the graphical representation corresponding to that reference tag to indicate that tag has been read 28 An inventory monitoring system comprising a read area within which a plurality of items are disposed each item bearing electronic item tag readable by an electronic tag reader a plurality of electronic reference tags disposed at prede termined locations spaced about the read area such that a reference tag being read by the electronic tag reader signifies that the electronic tag reader has effectively read that specific location of the read area associated with that reference tag scanning the electronic tag reader over the read area to read both item tags and reference tags and determining that the read area has been effectively scanned once each of the refe
15. iculties in reading multiple tags located within a read volume First an RFID reader has a somewhat unclear read zone meaning it is not intuitive to the user what area is being read Secondly unlike reading a bar code on an item where it is one bar code one beep per item an RFID reader is expected to read multiple RFID tags within the read volume and the user system may not know how many tags are present The present inventor has determined that all tags in a read volume are not always successfully read during a single read operation and the user may not know that the reader failed to detect some of the tags in the volume A first preferred embodiment is directed to a reading sys tem monitors operator and equipment performance during repetitive read operations or inventories checking for a com plete sweep of the reader s RF field across the volume to be read For convenience this reading system will be referred to as a sweep sentinel system A sweep sentinel system com prises reference electronic tags such as RFID tags placed at suitable locations in the read volume to be interrogated When a set of tags is interrogated the combination reader 10 cap tures data from the reference tags in addition to the data from the tags located on inventoried goods When all the reference tags are read the inventory data is probably complete If some reference tags are not read the inventory data may be incom plete The reference tag data may be
16. ion wherein various formats of the display may be implemented such as a simple increasing number in the form of a numerical representation e g 1 2 3 50 or a bar graph with either a single or multiple bars 2 a countdown of the number of inventory items read wherein the expected number of items to be read within an inventory read operation is known or obtained and then the display screen 13 shows the beginning number of items expected counting down toward zero e g 50 49 48 2 1 0 and or 3 a display ofthe amount of operation time remaining wherein the display may shown a numerical countdown toward zero e g 10 9 8 2 1 0 ora graphical representation using bars or the like with decreasing amounts as the remaining time decreases The sweep sentinel system using reference tags is also applicable to fixed reader systems In one system boxes of items are arranged on pallets in a warehouse Each box has an RFID tag identifying the box and its contents Multiple boxes are arranged on a pallet It is desirable to read each of the RFID tags as the pallet is moved Reference tags are arranged on the pallet for example a reference tag on each corner and at the center So as the pallet is lifted by the forklift or passed through the RFID read zone of the passageway the reader may read both the reference tags and the item tags Depending upon whether all or some of the reference tags are tags are read provides an inference as to wheth
17. is met 3 A method according to claim 2 further comprising repeating subsequent read operation as long said trigger is 20 25 30 35 40 45 50 60 65 10 held wherein said termination criteria is met by reading a plurality of said reference tags 4 A method according to claim 2 wherein said termination criteria is met once said RFID reader captures an expected number at unique item tags 5 A method according to claim 2 wherein said termination criteria is met by counting a total number of distinct reference tags during a read operation and discontinuing subsequent read operation if said total number reaches a given value 6 A method according to claim 2 further comprising filling input fields on an inventory checklist with data acquired from the item tags wherein said termination criteria is met by completion of filling of the input fields 7 A method according to claim 2 wherein said termination criteria is met by obtaining data from said reference tags and data from said item tags and verifying complete inventory data 8 A method according to claim 2 wherein said termination criteria is met by detecting the release of said trigger 9 A method according to claim 2 wherein said termination criteria is met by detecting a maximum elapsed time since said trigger was activated 10 A method according to claim 2 wherein said termina tion criteria is met by detecting a maximum elapsed time since the most recen
18. l efficiency and inventory monitoring performance SUMMARY The preferred embodiment of the disclosure is a method of RFID reading comprising the steps of 1 pointing a handheld RFID reader toward a read area containing item tags and reference tags 2 actuating a trigger on the handheld RFID reader to commence reading RFID tags 3 performing a first read operation wherein the read operation comprises inter rogating and sensing at least one RFID tag in the read area 4 continung with a subsequent read operation comprising interrogating and reading at least one tag in the read area and 5 the RFID reader discontinuing subsequent read operations once a termination criteria is met These and other aspects of the disclosure will become apparent from the following description the description 20 25 35 40 45 50 55 60 65 2 being used to illustrate preferred embodiments when read in conjunction with the accompanying drawings BRIEF DESCRIPTION OF THE DRAWINGS FIG 1 is a diagrammatic view of a combined RFID system comprised of an RFID reader optical code reader and data terminal according to a preferred embodiment FIG 2 is a simplified block diagram of an RFID system of FIG 1 FIG 3 is a screen view for an input scheme ofa program for the system of FIG 1 FIG 4is a diagram of an RFID system illustrating an RFID reading field relative to an RFID tag FIG 5 is a flow chart of a method of RFID inventor
19. leased the new tag timeout occurs or the minimum number of tags has been read The new tag timeout 124 is the amount of time to wait between new tag reads before the inventory operation is ter minated The new tag timeout value corresponds to step 66 in FIG 5 The new tag timeout value is the maximum amount of time spent waiting for a new tag to be read after the last new tag that had previously been read The minimum tag count 126 is the minimum number of tags to attempt to read If set to infinite the reading searching for new tags will continue until the trigger is released or one of the timeout conditions are met improve operability during an inventory reading pro cess additional feedback may be provided to the operator Audible indicators such as a beep tone at a given pitch may signal the successful read of an RFID tag In a preferred US 7 394 358 B2 9 embodiment a signal may be sounded only when a new tag is read Once all the tags are determined to have been read then an alternate signal may be sounded For example the alter nate signal may be a plurality of differing pitched sounds a multiple tone a beep a long tone a short tone and or a combination of beeps tones and pitched sounds to provide a signal to the user that the reading operation is complete The display 13 may provide a plurality of feedback schemes during the inventory reading process including 1 a quantity of tags read during the operat
20. m 16 wherein said termina tioncriteriais metby completing input of field inventory data 19 A system according to claim 16 wherein said termina tion criteria is met by obtaining data from the reference tag s and data from said item tags and verifying complete inventory data 20 A system according to claim 16 wherein said means for actuating comprises a switch on said electronic data reader and said termination criteria is met by detecting release of said switch 21 A system according to claim 16 wherein said termina tion criteria is met by detecting a maximum elapsed time since said switch was activated 22 A method according to claim 11 wherein said indica tion signal is a graphical display of locations of reference tags that have not been read 23 A method of electronic tag reading comprising the steps of arranging a plurality of reference tags at specific locations about a read area using an electronic tag reader to read electronic tags including both item tags and reference tags disposed in the read area wherein an item tag is disposed on an item and includes identification data corresponding to that item wherein a reference tag is positioned at a specific location in the read area such that a successful read by the electronic tag reader of that reference tag signifies that the electronic tag reader has effectively read a region proximate that specific location of the read area 40 45 12 24 method accordin
21. ng the user to re sweep the shelf area or even a particular section of the shelf area By being able to move the combination reader 10 during the tag inventory operation the user may relocate the direc tion of the antenna so as to better locate and read RFID tags 133 134 136 on items and reference tags 132a 132b 132c 132d 132e at different positions and orientations For example if the inventory items as illustrated in FIG 9 contain metal RFID tags located on an opposite side ofthe inventory item from the reader may be more difficult to read Thetags on the opposite side of items containing metal are more difficult to read or do not read at all because the metal interposed between the reader these tags tends to absorb the electromag netic fields By moving around to an opposite side or to the side of the inventory items containing metal the user may reorient the reading ofthe RFID tag so that the RF signal need not pass through the metal The shelf as illustrated in FIG 9 may be too wide or there may be multiple shelves preventing the reader from reading all of the inventory items on the shelf froma single position The user may activate the combination reader 10 holding the trigger 19 and moving the reader in a sweeping motion along the shelf or each one of a plurality of shelves so as to read all the RFID tags and reference tags on the shelf Preferably the RFID tag data is reported as it is read and becomes available prior to the
22. nvironment Once the combination reader 10 is powered on onscreen instructions may be used to calibrate the touch screen 13 Accessing the configuration settings a set oftrigger options are accessed in the display 40 thatis shown in FIG 3 Using the display 40 the pistoltrigger 19 may be enabled or disabled The data reading device selected may be operable by the pistol trigger 19 in this configuration For example in the configuration of buttons 42 that are shown in FIG 3 the RFID interrogator 20 may be selected to be actuated by the pistol trigger 19 The barcode scanner may be set to be actuated by the scan key 25 using the buttons 44 Alternately when the combination reader 10 includes an imaging reader or imaging system the system may be activated by either the pistol trigger 19 or scan key trigger 25 The user may select either trigger by activating the onscreen selection process US 7 394 358 B2 7 Once the combination reader 10 is enabled to read RFID tags and or reference tags an application may be opened on the terminal 12 that accepts data in a suitable format For example the terminal 12 may accept keyboard wedge data which is accepted by Microsoft Wordpad program Once the program is activated RFID tags may be read by the steps of 1 aiming the combination reader 10 toward the RF field where inventory tags and reference tags are located 2 press ing the trigger 19 wherein the front LED 17 turns orange indicating
23. o send information Typically RFID tags are affixed to various articles for allowing identification of items in a sales transaction or tracking movement of the articles through a warehouse location In a typical RFID tag system the components forming the interrogator are a receiver a transmitter an antenna a microprocessor and memory Through the use of the interrogator RFID tags are enabled to receive store and transmit article identifying data without manual handling operations RFID tags may be read only or read write Passive RFID tags may be implemented without an internal power source and draw their power from the radio frequency RF energy transmitted from the reader Active RFID tags may include a power source such as a battery RFID tags may be low or high frequency depending on the applications Existing RFID systems do not provide feedback to the user of an RFID reader to indicate whether or not the user com pletely covered an inventory area The present inventors have recognized that it may be advantageous for a user to know what the RFID antenna coverage area is so that the user may completely cover an inventory area For applications with multiple inventory items such as in a warehouse existing RFID systems provide no indication whether all swept RFID tags have been read The present inventors have recognized the desirability of providing methods and systems in the operation of RFID reading systems for improving operationa
24. on wherein the read operation comprises interrogating and sensing one or more RFID tags in the read area b interrogating one or more reference tags in the read area c continuing with a subse quent read operation comprising reading one or more tags in the read area and d the RFID reader discontinuing subse quent read operations once meeting a termination criteria There are various mechanisms and methods for the termi nation criteria For example in one configuration when acti vating the trigger 19 the user may hold the trigger 19 and the reading operation may continue as long as the user holds the trigger In another configuration the user may actuate the read operation by a first trigger pull and release with the read 20 30 40 45 50 55 60 65 4 operation continuing until a subsequent second trigger pull that notifies the system to terminate There are various embodiments for software to make deci sions In one method the system may have knowledge that a discrete number of RFID tags either inventory or reference are expected in a particular read operation by using a counting mechanism For example when reading a pallet of items in a warehouse the system might know that there are 50 RFID tags to be read wherein each tag identifies a particular inven tory or pallet item In addition there may be several reference tags located among the inventory or pallet items The refer ence tags provide a check
25. provide a visual indicator 6 At step 62 read termination begins determining whether all the inventory and reference tags have been read by check ing if a predetermined number of reference and or inventory tags have been read 7 At step 64 read termination continues determining whether an operation timeout has occurred whereby the tim eout time is started at step 54 or 56 and runs continuously as the inventory and reference tags are read wherein the timeout time may be programmable and set to a value depending on the combination reader 10 requirements or may be a variable adjusted reader depending upon certain read criteria such as average RFID signal strength detected 8 At step 66 read termination continues determining whether a new tag timeout has occurred whereby the timer is re started at step 60 each time a new inventory and reference tag is detected as being read wherein as long as new tags are being read itis desired to permit the combination reader 10 to continue reading tags and wherein the timeout may be pro grammable and set to a value depending upon the reader requirements or may be variable adjusted by the reader depending upon certain read criteria such as average RFID signal strength 9 At step 68 read termination continues determining if the trigger has been released 10 At Step 70 if no read termination has been indicated then returning to Step 56 and continue tag inventory 11 At Step 72 if a read termina
26. rence tags has been read 29 A method of inventory monitoring in which a given number of items are disposed on a pallet each item bearing an electronic item tag containing identification information cor responding to the item the method comprising the steps of providing the pallet with at least one electronic reference tag the reference tag containing information relating to the pallet determining the given number of items on the pallet by using an electronic tag reader to obtain the information from the reference tag using the electronic tag reader to read the item tags on the items and discontinuing reading once the given number of items have been read 30 A method according to claim 29 wherein the informa tion contained by the reference tag includes the number of items on the pallet UNITED STATES PATENT AND TRADEMARK OFFICE CERTIFICATE OF CORRECTION PATENT NO 7 394 358 B2 Page 1 of 1 APPLICATION NO 11 230365 DATED July 1 2008 INVENTOR S Craig D Cherry It is certified that error appears in the above identified patent and that said Letters Patent is hereby corrected as shown below Column 1 Line 9 after of insert each tae Column 10 Line 49 before unique change at to of Signed and Sealed this Twenty third Day of September 2008 TS JON W DUDAS Director of the United States Patent and Trademark Office
27. slide button 112 selects how often RFID tag data is reported to an application When set to a specific number of tags data is reported when at least the selected number of new tags has been read When set to the minimum that is one tag each time a new tag is read it is reported after being read When set to infinite data is only reported when a reading operation is complete such as when all the reference tags have been read Selecting the checkbox 114 forinventory tags which may be a read class 0 tags and or checkbox 116 for reference tags which may be a read class 1 tags selectively enables or disables the device to read each class of RFID tags The reader may be configured to recog nize only item tags to recognize only reference tags or to recognize both item and reference tags Improved perfor mance may be achieved by enabling only the tags which will be used For example tag selection may facilitate special operations such as checking that the reference tags are in place FIG 8 illustrates a screen shot 120 of display 13 selecting an input scheme for differing read limit values including a total read timeout 122 a new tag timeout 124 and a minimum tag count 126 The total read timeout 122 is thetime for which the combination reader 10 will be allowed to read before terminating the operation This value corresponds to step 64 in FIG 5 If set to infinite then the reading searching for new tags will continue until the trigger is re
28. t read of an RFID tag 11 A method of electronic tag reading comprising the steps of passing a handheld electronic tag reader past a read vol ume said read volume containing multiple electronic tags including at least one item tag and at least one reference tag wherein an item tag is disposed on an item and includes identification data corresponding to that item wherein a reference tag is positioned at a predeter mined location in said read volume rather than disposed on an item such that when read by the electronic tag reader signifies that the electronic reader has effectively read a region proximate that location of the read volume activating said reader reading at least one of said electronic tags and notifying a user of said reading by an indication signal representing that said electronic tags have been read 12 A method according to claim 11 wherein said indica tion signal is a graphical display of locations of reference tags that have been read 13 A method according to claim 11 wherein a single reader activation comprises a plurality of read operations wherein a read operation comprises interrogating and sensing at least one electronic tag in said read volume 14 A method according to claim 11 wherein said indica tion signal is an audible tone indicating the reading of said electronic and reference tags 15 A system for reading a plurality of electronic tags disposed in a read area comprising a an electronic
29. tag reader for reading electronic tags b a plurality of electronic tags including item tags and at least onereference tag disposed in the read area wherein an item tag is disposed on an item and includes identi fication data corresponding to that item wherein a ref erence tag is positioned at a specific location in the read area such that when read by the electronic tag reader signifies that the electronic tag reader has effectively read a region proximate that specific location ofthe read area C means for actuating said electronic tag reader to com mence reading said electronic tags d wherein said electronic tag reader is operative 1 to perform a first read operation US 7 394 358 B2 11 wherein said first read operation comprises interrogating and sensing the at least one reference tag and one or more item tags in said read area 16 A system according to claim 15 wherein the electronic tag reader is further operative ii to continue with a subse quent read operation comprising interrogating and reading at least one or more electronic tags in said read area and iii to discontinue subsequent read operations once a termination criteria is met 17 A system according to claim 16 wherein said termina tion criteria is met by counting a total number of distinct reference tags during a read operation and discontinuing sub sequent read operation if said total number reaches a given value 18 A system according to clai
30. that the RFID interrogator 20 is in operation 3 sounding an audible beep of differing pulses when the inven tory tags and reference tags are read 4 entering the RFID read into an application and 5 when the read is finished the LED 17 is turned off and a final beep is sounded indicating that the read operation is complete FIG 5 is a flow chart ofa preferred method 50 as described in the following steps 1 The system may start either by a hardware trigger pull atstep 52A or by asignal from an operating software protocol at step 52B 2 The system may commence an RFID tag inventory operation at step 54 3 The RFID interrogator may be instructed to read the inventory tags and reference tags 56 wherein the interrogator emits a signal instructing the inventory tags and reference tags to transmit their data and whereby the interrogator then receives the signals from all the tags 4 Determining at step 58 whether any new tags have been read whereby if No then continue scanning at step 62 and if Yes proceed to step 60 wherein at step 58 the combina tion reader 10 compares a tag read list to a list of inventory and reference tags previously read and only register a new read when the tag read has not been previously indicated during the current inventory sweep 5 Indicating a new tag has been read at step 60 wherein the indication may be actuating an audible tone at beeper 24 and or actuating the LED 17 and or LED 17a to
31. tion has been indicated ending the RFID tag inventory 20 25 30 35 40 45 50 55 60 65 8 The method of FIG 5 includes multiple termination events or Steps 62 64 66 68 and 70 The order of these events may be re arranged or one or more of the events may be omitted depending on the application Which of these termination steps or the combination of steps is applied may be user selected with a suitable program interface For example the combination reader 10 may terminate the read only via release of the trigger at Step 68 with the Steps 62 64 66 and or 70 omitted FIG 6 illustrates a screen shot 100 of display 13 using an input scheme for selecting the audio indicators A volume slide button 102 enables the user to select a beep volume from zero to maximum There are several audible indicators in the combination reader 10 wherein each of the indicators are adjustable being selected by the drop down menu 104 A Good Read type is shown in FIG 6 Other indicators may include All Tags Read type as from Step 62 in FIG 5 Once the type 104 is selected the tone may be adjusted selected by slide button 106 The beep duration may be selected by slide button 107 and the number of beeps may be selected by slide button 108 For example a triple beep may be sounded to indicate that all tags have been read FIG 7 illustrates a screen shot 110 of display 13 showing aninput scheme for report settings A
32. y monitoring according to a preferred embodiment FIG 6 is a screen shot for an input scheme of an audio portion for the system of FIG 1 FIG 7 is a screen shot for an input scheme of report settings for the system of FIG 1 FIG 8 is a screen shot for an input scheme of read limits for the system of FIG 1 FIG 9 is an illustration of a reference tag setup in a shelf environment and a data reader with a display of reference tags DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS The preferred embodiments will now be described with reference to the drawings While the preferred embodiments are described below with reference to an RFID tag a practi tioner in the art will recognize the principles described herein are viable to other applications FIG 1 illustrates a handheld combination device 10 having a portable terminal section 12 a handle section 18 and an RFID antenna section 20 The portable terminal section 12 includes a display screen 13 and a keypad section 14 for providing control or data input into the terminal or displaying information to a user The terminal 12 includes LED indica tors 17 and 17a The terminal 12 includes a front window 15 through which a data reading device for example an imaging reader or a laser scanner may operate to read optical codes The data reading device may detect an image within a field of view The reader 10 may be a combination system with vari ous functions controlled by the terminal 12
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