(19) United States
`(12) Patent Application Publication (10) Pub. No.: US 2013/0049925 A1
`SUBRAMANIAN
`(43) Pub. Date:
`Feb. 28, 2013
`
`US 20l30049925A1
`
`ADJUSTABLE-ORIENTATION RFID TAG
`READER SYSTEl\'lS AND l\'lETHODS OF
`THEIR OPERATIOV
`
`lnVem0r5
`
`Pan‘3h_aPake5an V- SUBRAMAR IAN»
`Frcdcncks MD (US)
`
`A55ignee3 SYNIBOL TECHN0L0GIESs INC-.~
`H01l5Vi11ea NY (US)
`
`APP1~ N05 13/214:8”
`
`Fi1Cd3
`
`Aug- 22; 2011
`
`Publication Classification
`
`Int. Cl.
`G051} 23/02
`
`(2006.01)
`
`(52) U.S. Cl.
`
`...................................................... .. 340/3.1
`
`ABSTRACT
`(57)
`include a radio frequency identification
`Embodi111e11ts
`(RFID) tag reader system and methods of its operation. The
`system includes a drive system and an RFID tag reader. The
`RFID tag reader includes a directional anteima configured to
`receive RF signals within a radiowave beam (e.g. RFID tag
`response signals from RFID tags when the RFID tags are
`Within an area encompassed by the radiowave beam). An
`embodiment of the system also includes a camera configured
`to capture images within a field of View. The drive system is
`coupled to the directional antenna and the camera, and is
`configured to change physical orientations of the directional
`antenna and the camera with respect to a fixed coordinate
`system, resulting in adjustments to angular orientations ofthe
`radiowave beam a11d the field of view with respect to the fixed
`coordinate system.
`
`EXTERNAL
`SYSTEM
`
`RFC - Exhibit 1006
`
`1
`
`

`
`Patent Application Publication
`
`Feb. 28, 2013 Sheet 1 of 5
`
`US 2013/0049925 A1
`
` SYSTEM
`
`FIG. I
`
`2
`
`

`
`Patent Application Publication
`
`Feb. 28, 2013 Sheet 2 of 5
`
`US 2013/0049925 A1
`
`FIG.2
`
`3Q ‘
`
`R
`
`160165
`
`3
`
`

`
`Patent Application Publication
`
`Feb. 28, 2013 Sheet 3 of 5
`
`US 2013/0049925 A1
`
`EXTERNAL
`SYSTEM
`PROCESSOR
`
`DRIVE
`SYSTEM
`CONTROLLER
`
`DRIVE SYSTEM
`
`CAMERA
`
`ANTENNA
`
`\
`
`RFID TAG
`
`ARTICLE
`
`RFID
`TAG
`READER
`CONTROLLER
`
`RECEIVER
`
`TRANSMITTER
`
` I
`
`4
`
`

`
`Patent Application Publication
`
`Feb. 28, 2013 Sheet 4 of 5
`
`US 2013/0049925 A1
`
`BEGIN
`
`402
`
`404
`
`406
`
`RECEIVE AND STORE CONTROL PARAMETERS
`
`PERFORM POLLING OPERATION:
`CAPTURE IMAGE DATA AND ATTEMPT TO DETECT RFID
`TAGS WHILE CONTROLLING DRIVE SYSTEM TO PAN/TILT
`FIELD OF VIEW AND DETECTION BEAM THROUGH
`PAN/TILT RANGES
`
`
`
`ASSOCIATE AND TRANSMIT RFID TAG IDENTIFYING DATA,
`IMAGE DATA, AND ANGULAR ORIENTATION DATA TO
`EXTERNAL SYSTEM
`
`FIG. 4
`
`5
`
`

`
`Patent Application Publication
`
`Feb. 28, 2013 Sheet 5 of 5
`
`US 2013/0049925 A1
`
`BEGIN
`
`
`
`TRANSMIT CONTROL PARAMETERS TO THE RFID TAG
`READERS AND INITIATE POLLING OPERATIONS
`
`RECEIVE RFID TAG IDENTIFYING INFORMATION, IMAGE
`DATA, AND ANGULAR ORIENTATION DATA FROM ONE OR
`MORE RFID TAG READERS
`
`502
`
`504
`
`506
`
`UPDATE CURRENT INVENTORY
`
`
`
`FIG. 5
`
`6
`
`

`
`US 2013/0049925 A1
`
`Feb. 28, 2013
`
`ADJUSTABLE-ORIENTATION RFID TAG
`READER SYSTEMS AND METHODS OF
`THEIR OPERATION
`
`tems. Further needed are inventory monitoring systems that
`enable specific articles readily to be located within a retail
`store or other controlled area.
`
`TECHNICAL FIELD
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`[0001] Embodiments of the present invention generally
`relate to radio frequency identification (RFID) tag reader
`systems and methods of their operation.
`
`BACKGROUND
`
`[0002] Maintaining an understanding of current inventory
`is an important aspect of retail sales operations. Accordingly,
`various inventory-taking systems and processes have been
`employed, over the years, to assist retail store personnel in
`determining accurate estimates of current inventory. These
`systems and processes have included manual counting pro-
`cesses and handheld scanner based systems (e.g. barcode
`scanner systems and, more recently, systems that employ
`RFID technology). Manual counting processes are time con-
`suming and prone to human error. When compared with
`manual counting processes, handheld scanner based systems
`have produced significant gains in efficiency and accuracy.
`[0003]
`In a system that employs RFID technology, an RFID
`tag is applied to each article for which inventory tracking is
`desired. The RFID tag is capable of transmitting an inforrna-
`tion-bearing, radio frequency signal, which may be detected
`by an RFID tag reader. The information within the RFID tag
`signal typically includes an identification number that may be
`correlated with a particular item of inventory. In order to take
`a full inventory within a retail store space, store personnel
`with handheld RFID tag readers make rounds through the
`store and, at various locations, control the RFID tag reader in
`a manner that causes the RFID tag reader to detect any RFID
`tags that may be within range of the RFID tag reader. The
`information collected by the RFID tag reader may then be
`analyzed to generate an estimate of the current inventory.
`[0004] An RFID-based system has the benefit of increased
`efficiency and/or accuracy, when compared with traditional
`manual
`inventory-taking processes and barcode scanning
`systems. For example, manual inventory-taking processes are
`prone to human error, and barcode scanning systems typically
`require the individual who is taking inventory to physically
`handle each tag in order to scan its barcode. In contrast, an
`RFID tag reader accurately can read identification informa-
`tion for an RFID tag without physical handling of the RFID
`tag, and the RFID tag reader may be able to receive simulta-
`neous responses from multiple RFID tags within its range.
`[0005] Although the use of RFID technology has increased
`the efficiency and accuracy associated with an inventory tak-
`ing process, the process still takes dedicated human resources
`and a significant amount of time to complete. Accordingly,
`even with RFID systems, a retail store may take inventory
`relatively infrequently (e. g. perhaps once a month, once a
`week, or less often). In addition, none of the above-described
`systems enable store personnel readily to determine the loca-
`tions of particular articles within the store. Inaccurate knowl-
`edge of current inventory may, in some circumstances, lead to
`lost sales and less-than-optimal customer satisfaction due to
`unavailability of desired articles or sizes and/or the inability
`to locate desired articles, for example. Accordingly, what are
`needed are inventory monitoring systems that enable inven-
`tory to be taken accurately and more often than is practicable
`with conventional, handheld scanner based inventory sys-
`
`[0006] Embodiments of the present invention will herein-
`after be described in conjunction with the following drawing
`figures, wherein like numerals denote like elements, and
`[0007]
`FIG. 1 is a top view of a simplified depiction ofan
`RFID tag reader system deployed in a controlled area, in
`accordance with an example embodiment;
`[0008]
`FIG. 2 is a side view of the RFID tag reader system
`of FIG. 1 along line 2-2, in accordance with an example
`embodiment;
`[0009]
`FIG. 3 is a simplified block diagram ofan RFID tag
`reader system coupled with an external system, in accordance
`with an example embodiment;
`[0010]
`FIG. 4 is a flowchart of a method for operating an
`RFID tag reader system, in accordance with an example
`embodiment; and
`[0011]
`FIG. 5 is a flowchart of a method for updating inven-
`tory information, in accordance with an example embodi-
`ment.
`
`DETAILED DESCRIPTION
`
`"adjustable-orientation”
`include
`[0012] Embodiments
`RFID tag reader systems and methods of their operation.
`Unlike the handheld RFID tag readers previously described,
`an RFID tag reader of an embodiment may be positioned at a
`fixed location within a controlled area in which RFID tag
`detection capabilities are desired, and the RFID tag reader
`may be operated using computer control. The RFID tag
`reader may receive identification information from RFID tags
`that are within range of the RFID tag reader, where the range
`corresponds to the maximum distance at which an RFID tag
`may be located while still being detectable. When the range of
`a single RFID tag reader is not sufficient to provide complete
`RFID tag detection coverage of the entire controlled area,
`additional RFID tag readers may be positioned in other loca-
`tions in the controlled area. The RFID tag readers may report
`the RFID tag identifying data to an external system (e.g. an
`external inventory monitoring system), and the external sys-
`tem may combine the reported RFID tag identifying data
`from all of the RFID tag readers to generate and maintain a
`comprehensive list of detected RFID tags. When setting up
`such a system, the detection range of each RFID tag reader is
`taken into account when determining the number and place-
`ment of RFID tag readers within the controlled area. Desir-
`ably, the number and placement of the RFID tag readers is
`such that full RFID tag detection coverage of the controlled
`area is achieved.
`
`[0013] The detection range of an RFID tag reader depends
`on the gain of the RFID tag reader’s antenna. Conventional
`RFID tag readers include non-directional antennas with gains
`in a range of about 6 dBi (decibels isotropic, which provides
`a measurement of the forward gain of an antenna). Although
`such conventional RFID tag readers may be capable ofdetect-
`ing RFID tags essentially in all directions, the range of such
`RFID tag readers is relatively short (e.g. about 10 to 20 feet).
`[0014]
`In contrast, and according to an embodiment, an
`RFID tag reader includes a directional, high-gain antenna that
`has a significantly farther range than a conventional RFID tag
`reader. The high-gain antenna has a significantly more narrow
`
`7
`
`

`
`US 2013/0049925 A1
`
`Feb. 28, 2013
`
`and focused radiowave beam within which RFID tags may be
`detected, when compared with a non-directional antenna
`employed in a conventional RFID tag reader. This radiowave
`beam is referred to herein as a “detection beam” or simply
`“beam.” The relatively narrow detection beam of the high
`gain antenna of an RFID tag reader of an embodiment is
`compensated for by physically coupling the high-gain
`antenna with a mechanism for dynamically adjusting the
`orientation of the high-gain antenna (referred to herein as an
`“orientation adjustment mechanism”), and thus the direction
`of the detection beam associated with the high-gain antenna.
`[0015] As will be described in detail below, the orientation
`of the RFID tag reader antenna is controlled so that its detec-
`tion beam scans through an area that is larger than the area
`encompassed by the detection beam. Because the detection
`range of the high-gain antenna of an embodiment of an RFID
`tag reader may be significantly farther than the detection
`range of a conventional RFID tag reader, the dynamic control
`of the RFID tag reader antenna enables a single RFID tag
`reader to detect RFID tags within a significantly larger area
`than can be achieved using a conventional RFID tag reader.
`[0016] According to a further embodiment, a camera may
`be mounted with the RFID tag reader antenna to the orienta-
`tion adjustment mechanism. By coupling the camera to the
`orientation adjustment mechanism, the camera may be oper-
`ated as a pan-tilt (PT) camera. When the camera also has
`zoom capabilities, the camera may be operated as a pan-tilt-
`zoom (PTZ) camera.
`[0017] According to an embodiment, the camera and RFID
`tag reader antenna may be mounted to the orientation adjust-
`ment mechanism so that the field of view of the camera and
`
`the detection beam of the RFID tag reader antenna com-
`pletely or partially overlap. In such an embodiment, image
`information captured by the camera and RFID tag identifica-
`tion information captured by the RFID tag reader may be
`correlated in time and space, which provides for a number of
`advantages, as will be described in more detail below.
`
`[0018] According to a still further embodiment, one or
`more of such RFID tag readers may be coupled with an
`external system, such as an inventory monitoring system, a
`security system, or another type of system. The external sys-
`tem may be configured to control the times when RFID tag
`detection processes are performed and when image informa-
`tion is captured. In addition, the external system may be
`configured to dynamically control the orientation ofthe RFID
`tag reader antenna (and the camera, when it is included with
`the RFID tag reader antenna) and camera, and to adjust the
`zoom setting and other operational features of the camera.
`
`FIG. 1 is a top view ofa simplified depiction of an
`[0019]
`RFID tag reader system 100 deployed in a controlled area
`160, in accordance with an example embodiment. FIG. 1
`should be viewed in conjunction with FIG. 2, which is a side
`view of the RFID tag reader system 100 of FIG. 1 along line
`2-2, in accordance with an example embodiment. System 100
`includes a plurality of RFID tag readers 101, 102, 103, 104,
`105,106,107,108,109 deployed in a controlled area 160, one
`or more RFID tags 120, and an external system 130 commu-
`nicatively coupled with the plurality of RFID tag readers
`101-109. Although nine RFID tag readers 101-109 are illus-
`trated in FIG. 1, the number of RFID tag readers 101-109 may
`be any integer number, N, where N may be from 1 to poten-
`tially hundreds of RFID tag readers 101-109. In addition,
`although only one RFID tag 120 is illustrated in FIG. 1, the
`
`number of RFID tags 120 may be any integer number, M,
`where M may be from 1 to potentially thousands of RFID tags
`120.
`
`for
`[0020] The controlled area 160 may be defined,
`example, by one or more walls 161, 162, 163, 164 (FIG. 1), a
`ceiling 165 (FIG. 2), and a floor 166 (FIG. 2), although the
`controlled area 160 need not be so defined. RFID tag readers
`101-109 are positioned in fixed locations throughout the con-
`trolled area 160. For example, as indicated in FIG. 2, RFID
`tag readers 101-109 are affixed to the ceiling 165 of the
`controlled area 110. However, this is not a necessity. In other
`example configurations, an RFID tag reader may be afiixed to
`the floor, to a wall, to a shelf, to a post, or to any other point
`within a controlled area. Further, although a controlled area
`160 having a substantially rectangular shape is depicted in
`FIG. 1, and the RFID tag readers 101-109 are shown to
`provide complete coverage of the controlled area 160,
`embodiments of the inventive subject matter may be used in
`any size or shape of controlled area 160, and/or the controlled
`area may not be bound by walls, and/or the RFID tag readers
`may be deployed so that only partial coverage of the con-
`trolled area is established.
`
`[0021] Each RFID tag reader 101-109 is configured to
`detect the presence of any RFID tags 120 that are located
`within a detection area associated with the RFID tag reader
`101-109 (e.g. detection areas 111, 112, 113, 114, 115, 116,
`117, 118, 119), and to transmit RFID tag identifying data for
`each detected RFID tag 120 to external system 130. As men-
`tioned previously and as will be described in more detail later,
`each RFID tag reader 101-109 includes at least one direc-
`tional antenna (not illustrated), which is configured to receive
`RF signals (e.g. RFID tag response signals) within a detection
`beam 121, 122, 123, 124, 125, 126, 127, 128, 129. The direc-
`tional antennas included in RFID tag readers 101-109 are
`sufficiently high gain so that the detection beams 121-129
`have relatively narrow beam widths. For example, the beam
`widths ofthe detection beams 121-129 may be such that each
`detection beam 121-129 only partially encompasses the asso-
`ciated detection area 111-119 for each RFID tag reader 101-
`109. For example, RFID tag reader 105 includes a directional
`antenna associated with detection beam 125, and detection
`beam 125 has a beam width that is too narrow to cover the
`
`entire detection area 115 associated with RFID tag reader
`105. As will be described in more detail below, and according
`to an embodiment, the orientation of the directional antenna
`of RFID tag reader 105 may be dynamically adjusted to
`ensure that the detection beam 125 pans across and through
`substantially all of the detection area 115. Accordingly,
`although the detection beam 125 is too narrow to cover the
`entire detection area 115 at any given instant, by dynamically
`moving the directional antenna (and thus the detection beam
`125), the detection beam 125 may be controlled to cover the
`entire detection area 115 over a period of time.
`[0022] According to an embodiment, in order to provide for
`dynamic adjustment of the orientation of the directional
`antenna of each RFID tag reader 101-109, each directional
`antenna is coupled with a drive system (not illustrated in FIG.
`1) that is configured to change the physical orientation of the
`directional antenna with respect to a fixed coordinate system
`150. This results in adjustments to an angular orientation of
`each detection beam 121-129 with respect to the fixed coor-
`dinate system 150. In other words, the drive system may be
`controlled to cause each detection beam 121-129 to be rotated
`across an entire detection area 111-119. This enables an RFID
`
`8
`
`

`
`US 2013/0049925 A1
`
`Feb. 28, 2013
`
`tag 120 located anywhere within a detection area 111-119 to
`be detected, despite the narrowness of the detection beam
`121-129. For example, although RFID tag 120 is not shown to
`be within the detection beam 125 of RFID tag reader 105 in
`either FIG. 1 or FIG. 2, the drive system associated with RFID
`tag reader 1 05 may rotate the directional antenna, and thus the
`detection beam 125, to be coincident with the location of
`RFID tag 120, thus enabling detection of RFID tag 120.
`[0023]
`From the perspective of FIG. 1 (i.e. a top View of
`controlled area 160), assume that the fixed coordinate system
`150 is defined by an x-axis (as shown in FIGS. 1 and 2), a
`y-axis (as shown in FIG. 1), and a z-axis (as shown in FIG. 2).
`By controlling the drive system of RFID tag reader 105, the
`directional antenna and detection beam 125 may be rotated
`around the z-axis through a range ofrotation (e. g. 360 degrees
`to cover the entire portion of detection area 115 that is co-
`planar with the x-y plane). Referring also to FIG. 2, the drive
`system of RFID tag reader 105 may be further controlled to
`rotate the directional antenna and detection beam 125 around
`
`the y-axis through a range of rotation (e.g. 180 degrees to
`cover the portion of detection area 115 that is co-planar with
`the X-Z plane and below the ceiling 165 of the controlled area
`160). In addition, the drive system of RFID tag reader 105
`may be further controlled to rotate the directional antenna and
`detection beam 125 around the x-axis through a range of
`rotation, even though a separate figure is not included to
`depict such an embodiment for purposes of conciseness.
`Basically, the drive system associated with any particular
`RFID tag reader 101-109 may be controlled to rotate the
`directional antenna (and thus the detection beam 121-129) of
`the RFID tag reader 101-109 around one or more axes of a
`fixed coordinate system 150.
`[0024] The range of rotation (about any particular axis)
`through which a drive system may rotate a directional antenna
`and detection beam 121-129 may be pre-defined based on the
`placement of the RFID tag reader 101-109 (or more specifi-
`cally, the tag reader’s directional antenna) within the con-
`trolled area 160. For example, referring again to FIG. 1, RFID
`tag readers 101, 103, 107, and 109 each are placed in a comer
`of the controlled area 160. Accordingly, for RFID tag readers
`101, 103, 107, and 109, the range of rotation about the Z-axis
`may be pre-defined to be approximately 90 degrees. Con-
`versely, RFID tag readers 102, 104, 106, and 108 each are
`placed along a wall 161-164. Accordingly, for RFID tag read-
`ers 102, 104, 106, and 108, the range of rotation about the
`Z-axis may be pre-defined to be approximately 180 degrees.
`Finally, RFID tag reader 105 is placed in a central portion of
`controlled area 160. Accordingly, the range of rotation about
`the Z-axis for RFID tag reader 105 may be pre-defined to be
`360 degrees. Referring again to FIG. 2, the range of rotation
`about the y-axis for RFID tag readers 104, 106 may be pre-
`defined to be approximately 90 degrees, whereas the range of
`rotation about the y-axis for RFID tag reader 105 may be
`pre-defined to be approximately 180 degrees. The range of
`rotation about the x-axis may be similarly defined.
`[0025] The range of rotation of each RFID tag reader 101-
`109 may be established locally within each RFID tag reader
`101-109, or may be controlled by external system 130.
`According to an embodiment, the external system 130 com-
`municates control signals to the orientation adjustment
`mechanism of each RFID tag reader 101-109 to dynamically
`control the orientation of each directional antenna. In an
`
`embodiment, RFID tag readers 101-109 and external system
`130 communicate wirelessly over RF communication links,
`
`although this is not a requirement. In an alternate embodi-
`ment, some or all of RFID tag readers 101-109 may commu-
`nicate over wired connections with external system 130.
`Either way, external system 130 may be considered to be a
`remote processing system, with respect to RFID tag readers
`101-109, in that external system 130 can be remotely located
`from RFID tag readers 101-109, although this is not a require-
`ment. External system 130 is communicatively coupled with
`each of RFID tag readers 101-109, even though external
`system 130 is shown to be coupled only with RFID tag read-
`ers 107-109 in order to simplify FIG. 1.
`[0026] According to an embodiment, system 100 supports
`various types of communications between external system
`130 and RFID tag readers 101-109: control signals from
`external system 130 to RFID tag readers 101-109, as men-
`tioned above; and RFID tag identifying data from RFID tag
`readers 101-109 to external system 130. As will be described
`in more detail later, the RFID tag reader control information
`may include polling parameters, such as the times, frequen-
`cies, and/or durations of polling operations to be performed
`by the RFID readers 101-109. In addition, the polling param-
`eters may include polling antenna selections and polling
`antenna activation durations, among other things. The control
`signals from external system 130 to RFID tag readers 101-
`109 also may include signals that dynamically control the
`orientation adjustment mechanisms of each of the RFID tag
`readers 101-109. More specifically, the external system 130
`may provide signals to an orientation adjustment mechanism
`to which a directional antenna of an RFID tag reader 101-109
`is afiixed, in order to change the angular orientation of the
`detection beam with respect to fixed coordinate system 150.
`In an embodiment in which a camera also is coupled to each
`orientation adjustment mechanism, additional control signals
`from external system 130 may control when the camera
`actively captures images, the zoom level for image capture,
`and other controllable settings relating to image capture.
`[0027] The RFID tag identifying data sent from the RFID
`tag readers 101-109 to the external system 130 identifies
`RFID tags 120 that responded to polling operations con-
`ducted by the RFID tag readers 101-109. The RFID tag iden-
`tifying data enables the external system 130 to establish or
`maintain knowledge of all detectable RFID tags 120 that are
`within the controlled area 160. In addition, in an embodiment
`in which a camera is coupled with each orientation adjust-
`ment mechanism, the camera may communicate image data
`to the external system 130. Each orientation adjustment
`mechanism may communicate angular orientation data indi-
`cating the angular orientation of the RFID tag reader’s direc-
`tional antenna and the camera (and thus the detection beam
`and/or camera field of view) with respect to the fixed coordi-
`nate system 150. According to an embodiment, the RFID tag
`identifying data, the image information, and the angular ori-
`entation data may be correlated in time, as will be described
`in more detail later.
`
`[0028] External system 130 may be, for example, an inven-
`tory monitoring system, a security system, or any of a variety
`of systems that may benefit from the RFID technologies (and
`possibly the imaging technologies) employed in the various
`embodiments. For purposes of example, the remainder of the
`description below describes the external system 130 as being
`an inventory monitoring system. However, the description of
`an embodiment in which external system 130 is an inventory
`monitoring system should not be construed as limiting the
`scope ofthe inventive subject matter to a system that includes
`
`9
`
`

`
`US 2013/0049925 A1
`
`Feb. 28, 2013
`
`an inventory monitoring system. Instead, various types of
`external systems 130 may be used in conjunction with the
`various embodiments.
`
`FIG. 3 is a simplified block diagram ofan RFID tag
`[0029]
`reader system 300 coupled with an external system 330, in
`accordance with an example embodiment. For purposes that
`will be discussed in more detail later, RFID tag reader system
`300 and external system 330 exchange various data and con-
`trol signals 320 via communications (COM) interfaces 306,
`336, respectively.
`[0030] Communications interfaces 306, 336 may be wired
`or wireless (i.e., RF) interfaces, which may implement any of
`a number of communications protocols.
`[0031] RFID tag reader system 300 includes processing
`system 302, data storage 304, communications interface 306,
`an RFID tag reader, and an orientation adjustment mecha-
`nism. As will be described in more detail later, processing
`system 302 is configured to coordinate the operations of the
`RFID tag reader, the orientation adjustment mechanism, and
`in some cases, a camera 316, based on control signals
`received from an external system 330 via communications
`interface 306. In addition, processing system 302 is config-
`ured to coordinate transmission ofvarious types of data to the
`external system 330 via the communications interface 306,
`where the data may include one or more types of data selected
`from a group consisting of RFID tag identifying data (from
`the RFID tag reader), angular orientation date (from the ori-
`entation adjustment mechanism), and image data (from cam-
`era 3 1 6).
`In general, the RFID tag reader is configured to
`[0032]
`detect the presence of RFID tags (e.g. RFID tag 350) within a
`detection beam 340. According to an embodiment, the RFID
`tag reader includes an RFID tag reader controller 312, an
`antenna 314 (e.g. a directional antenna), and a receiver 317.
`Antenna 314 is configured to receive RF signals (e.g. RFID
`tag response signal 344 from RFID tag 350) within the detec-
`tion beam 340. Antenna 314 is a directional antenna (i.e. a
`high gain antenna), in an embodiment, which has a gain in a
`range of 8 to 15 dBi. Receiver 317 is coupled to the antenna
`314, and is configured to convert the RFID tag response signal
`344 into RFID tag identifying data. In an embodiment in
`which the RFID tag reader is configured to detect the presence
`of passive RFID tags (described below), the RFID tag reader
`may further include a transmitter 318.
`[0033] RFID tag reader controller 312 executes an RFID
`tag detection algorithm. The particular RFID tag detection
`algorithm depends on the type of RFID tag employed in the
`system. For example, in various embodiments, the RFID tag
`detection algorithm is configured to communicate with an
`RFID tag 350 selected from a group consisting of an active
`RFID tag, a passive RFID tag, and a battery-assist passive
`RFID tag. The RFID tag 350 may be coupled with an article
`352, such as an item of inventory. Alternatively, the article
`352 may be a person, an animal, or some other type of object
`to which an RFID tag 350 may be attached.
`[0034] Each of the above-mentioned types of RFID tags
`includes an integrated circuit for storing information (e.g. a
`tag and/or article identifier), processing RFID tag interroga-
`tion signals from an RFID tag reader, and transmitting an
`RFID tag response signal 344 that includes the stored identi-
`fication information. An RFID tag 350 also may be program-
`mable to store other information, such as the transaction
`status of an article 352 to which the RFID tag 350 is attached
`(i.e. whether the article is “transacted” (paid-for and sold) or
`
`“non-transacted” (not yet paid for or sold)). When an RFID
`tag 350 initially is attached to an article 352 and offered for
`sale, the transaction status may be initialized to “non-trans-
`acted,” and when the article is sold, equipment at the point-
`of-sale may be used to change the stored transaction status to
`“transacted.”
`
`[0035] An active RFID tag 350 includes a battery, and is
`capable of transmitting a signal (e.g. tag response signal 344)
`autonomously. In contrast, a passive RFID tag 350 does not
`include a battery, and requires a tag interrogation signal (e.g.
`tag interrogation signal 345) from an external source (e.g. the
`RFID tag reader) to provoke transmission of a tag response
`signal 344. A battery-assisted passive RFID tag 350, on the
`other hand, still requires an external source to invoke the tag
`to transmit a tag response signal 344, but the battery enables
`the RFID tag 350 to have a significant higher forward link
`capability than non-battery-assisted passive RFID tags, thus
`providing greater range.
`[0036] According to an embodiment, an RFID tag detec-
`tion algorithm is implemented by RFID tag reader controller
`312. For passive RFID tags, the tag detection algorithm
`includes invoking transmitter 318 to transmit a tag interroga-
`tion signal 345 via antenna 314, and attempting to detect a tag
`response signal 344 from an RFID tag 350 via antenna 314
`and receiver 317. For active RFID tags which transmit a tag
`response signal 344 automatically (i.e. not in response to an
`interrogation signal), transmitter 318 may be excluded from
`the RFID tag reader.
`[0037] The RFID tag detection algorithm also may include
`evaluating RFID tag response signals 344 received via
`receive antenna 314 and receiver 317 to determine whether
`
`they are valid RFID tag response signals. In addition, in an
`embodiment, the RFID tag detection algorithm is configured
`to provide information received in or derived from the RFID
`tag response signals to external system 330 when an RFID tag
`350 associated with (e.g. attached to) a particular article has
`been detected, thus indicating that an article 352 to which the
`RFID tag 350 is attached may be within a controlled area (e.g.
`controlled area 160, FIG. 1). For example, the information
`received in an RFID tag response signal 344 may include an
`RFID tag identifier or an article identifier (e. g. a SKU of the
`article 352 to which the responding RFID tag 350 is attached).
`The RFID tag detection algorithm may cause the RFID tag
`reader system 300 to send information that indicates the iden-
`tity of the RFID tag 350 or article 352 to the external system
`330, when it is determined that the RFID tag 350 is in range
`of the RFID tag reader. The information sent from the RFID
`tag reader system 300 to the external system 330 is referred to
`herein as “RFID tag identifying data,” which essentially
`includes any data derived based on an RFID tag response
`signal 344 that indicates the identity of an RFID tag (e.g.
`RFID tag 350) or an article to which the RFID tag is attached
`(e.g. article 352).
`[0038]
`In an embodiment, the information received in an
`RFID tag response signal also may include the stored trans-
`action status of the item (e.g. transacted or non-transacted),
`and the RFID tag detection algorithm may indicate to the
`external system 330 whether or not the article 352 was prop-
`erly purchased. In other words, the RFID tag reader system
`300 may report the transaction status stored in the RFID tag
`350 to the external system 330. The RFID tag reader control-
`ler 312 reports the RFID tag identifying data and the transac-
`tion status to the external system 330 via processing system
`302 and communications interface 306, in an embodiment.
`
`10
`
`10
`
`

`
`US 2013/0049925 A1
`
`Feb. 28, 2013
`
`In a further embodiment, the RFID tag reader sys-
`[0039]
`tem 300 also includes a camera 316. Camera 316 is config-
`ured to capture still or video images within a field ofview 346,
`and to produce image data corresponding to the images. Cam-
`era 316 may report the image data to the external system 330
`via processing system 302 and communications interface
`306, in an embodiment. Camera 316 may have a zoom capa-
`bility (i.e. the ability to provide image data with increased
`resolution within a narrower portion of the field of view 346)
`that is controllable based on control signals received from
`processing system 302.
`[0040] The orientation adjustment mechanism includes at
`least one drive system controller 308 and at least one drive
`system 310,
`in an embodiment. The drive system 310
`includes one or more controllable servomotors, which control
`the physical position of an attachment structure (not