1111111111111111 IIIIII IIIII 11111 1111111111 1111111111 lllll 111111111111111 1111111111 11111111
`US 20050151623Al
`
`(19) United States
`(12) Patent Application Publication (10) Pub. No.: US 2005/0151623 Al
`Jul. 14, 2005
`von Hoffmann
`( 43) Pub. Date:
`
`(54) PDA SECURITY SYSTEM
`
`Publication Classification
`
`(76)
`
`Inventor: Gerard von Hoffmann, Trabuco
`Canyon, CA (US)
`
`Int. Cl.7 ..................................................... G0SB 23/00
`(51)
`(52) U.S. Cl. .......................... 340/5.61; 711/150; 713/200
`
`Correspondence Address:
`KNOBBE MARTENS OLSON & BEAR LLP
`2040 MAIN STREET
`FOURTEENTH FLOOR
`IRVINE, CA 92614 (US)
`
`(21)
`
`Appl. No.:
`
`10/927,622
`
`(22)
`
`Filed:
`
`Aug. 26, 2004
`
`Related U.S. Application Data
`
`(63)
`
`Continuation of application No. 09/928,078, filed on
`Aug. 10, 2001, now abandoned.
`
`(57)
`
`ABSTRACT
`
`Disclosed is a personalized security system for use with a
`PDA or other portable electronic device. An interrogator
`signal is transmitted from the portable electronic device,
`triggering a responsive transmission of a password from an
`electronic key carried by the wearer. Certain selected func(cid:173)
`tions or all functions of the electronic device are therefore
`only enabled if the electronic device is within a predeter(cid:173)
`mined operating proximity of the electronic key. Also dis(cid:173)
`closed is a personal preference monitoring system, for
`allowing personal preferences to be automatically imple(cid:173)
`mented in response to a user passing within a predetermined
`distance of an interrogation signal transmitter.
`
`ELECTRONIC
`LOC
`K
`CIRCUI TRY
`
`!
`!
`
`L_
`
`;
`
`I
`'
`
`INTERROGATION
`
`I SIGNAL
`i
`
`17
`
`INTERROGATION
`SIGNAL
`TRANSMITTER
`16
`
`·-.
`
`PROCESSOR
`14
`
`REMOTE KEY
`20
`
`ENCODED
`SIGNAL
`RECEIVER
`18
`
`PASSWORD
`22
`
`'
`I
`'
`I
`!
`I
`I
`I
`
`I
`I
`I
`I
`I
`I
`
`I
`I
`I
`
`I . -·-. -· -. -. -·-· -. -. -. -·-. -·- ·- ·-· -. -·- ·-· -· -· -. -- --- • - • - -- ----. - • - . --- ·-·
`
`- -
`
`ELECTRONIC
`DEVICE
`10
`
`Page 1 of 14
`
`GOOGLE EXHIBIT 1019
`
`

`

`Patent Application Publication Jul. 14, 2005 Sheet 1 of 5
`
`US 2005/0151623 Al
`
`-. -. -. - . -. -. - . - . -. -. -. - . -. :. -. - . - . -. - . - . - . -. -. -. -. -. - . - ' - . -~. - . - . -. - . - . - . - . -. -. - . - . -.
`
`.
`'
`
`.
`
`I
`'
`'
`
`0::
`0 u,
`u,..,. w,...
`0
`0
`0:: n.
`
`"t"""'
`
`w
`0:::
`:::::,
`(!) -LL
`
`0
`zw
`Ou
`0::-o
`I-> ....
`ow we
`..J w
`
`Page 2 of 14
`
`

`

`Patent Application Publication Jul. 14, 2005 Sheet 2 of 5
`
`US 2005/0151623 Al
`
`0::: w
`I=
`~~ Cl) z
`~
`I-
`
`0::: w > WM
`
`(.) w
`0:::
`
`~
`ON
`::E '<t
`w
`::E
`
`0::: w
`_J
`_J
`Oo
`0::: '<t
`I-z
`0
`(.)
`
`'<t
`C")
`
`---
`--
`
`0::: w
`~ co
`WM
`(.)
`w
`0:::
`
`0::: w
`~(C
`0
`'<t
`a..
`
`~
`
`>-w
`(.) z
`0
`0:::
`I- N
`(.)
`w w
`_J w ~ ::,
`C) -LL
`
`C")
`C")
`
`0::: w
`--1=
`
`~N
`Cl) C")
`z
`~
`I-
`
`0::: w
`...J
`I- ...J
`cno o,
`00:::N
`I 1-z
`0
`(.)
`
`------
`
`co N
`
`(C
`C")
`
`LO
`C")
`
`CD
`N
`
`0
`C")
`
`0:::
`0
`!;i:
`C,
`0
`0:::
`0::: w
`1-(cid:173)z
`
`Page 3 of 14
`
`

`

`Patent Application Publication Jul. 14, 2005 Sheet 3 of 5
`
`US 2005/0151623 Al
`
`FIG.3
`
`,-,,o
`
`FIG. 7
`
`~ 1 0
`
`Page 4 of 14
`
`

`

`Patent Application Publication Jul. 14, 2005 Sheet 4 of 5
`
`US 2005/0151623 Al
`
`130
`
`FIG. lJ-
`
`124
`_,I
`
`137-6
`
`Page 5 of 14
`
`

`

`Patent Application Publication Jul. 14, 2005 Sheet 5 of 5
`
`US 2005/0151623 Al
`
`FIG. 5
`
`FIG. 6
`
`Page 6 of 14
`
`

`

`US 2005/0151623 Al
`
`Jul. 14, 2005
`
`1
`
`PDA SECURITY SYSTEM
`
`[0001] This application is a continuation of U.S. patent
`application Ser. No. 09/928,078 filed on Aug. 10, 2001, the
`disclosure of which is incorporated in its entirety herein by
`reference.
`
`BACKGROUND OF THE INVENTION
`
`[0002] The present invention relates to security systems
`for electronic devices, such as cellular telephones, PDA's,
`personal computers, and the like. More particularly, the
`present invention relates to an electronic key system that
`only enables all or selected functions of an electronic device
`when in proximity to an authorized user.
`
`[0003] Personal digital assistants (PDA's) currently pro(cid:173)
`vide a wide variety of productivity applications, such as a
`calendar, an address book, notes and memos, and an exten(cid:173)
`sive memory in a convenient, hand held form. One of the
`most popular current PDA's is the Palm Pilot, manufactured
`by 3Com Corporation. PDA's also provide certain telecom(cid:173)
`munications functions through the use of a separate modem.
`Such modem may be an external device, as in the case of the
`Palm Pilot, a built in software modem as in the case of some
`palm size PCs, or it may be an internal PC card, as in the
`case of the Apple Newton, manufactured by Apple Com(cid:173)
`puter Corporation. The telecommunications functions pro(cid:173)
`vided by a PDA when operated in conjunction with a modem
`can include the sending and receiving of email and access to
`computer networks, such as the Internet.
`
`[0004] PDAdesigns have recently been improved to incor(cid:173)
`porate a number of features previously found only in tradi(cid:173)
`tional laptop or desk top computers. For example, many
`recent PDAs have touch sensitive screens that allow a user
`to quickly and efficiently enter information by touching a
`stylus to the screen. The PDAs may employ a user friendly
`graphical user interface such as a Windows® or Windows®
`CE interface. In addition, the user may write messages
`directly on the screen using the stylus. The image produced
`may be transmitted via electronic mail or facsimile or may
`simply be stored in memory. With the advances in hand(cid:173)
`writing recognition, the PDA can interpret the writing and
`convert it into a text format.
`
`[0005] Various types of input/output devices are being
`developed to facilitate the transfer of information involving
`existing data on external media to the PDA. For example,
`optical scanners, memory cards such as PCMCIA cards,
`infrared transceivers, cables and some telecommunication
`techniques have been used to transfer information between
`the PDA and other sources. These various techniques allow
`the user to easily transfer data to and from the PDA in a
`mobile environment.
`
`[0006] Many PDAs are linked to Global Positioning Sat(cid:173)
`ellite (GPS) systems allowing the PDA to provide the user
`with a geographical location. Further, the PDA can provide
`information such as traveling directions if the PDA contains
`street information such as an electronic map.
`
`rently discrete devices, all of these devices will hopefully
`evolve into a simple, handheld, multi-functional unit.
`
`[0008] PDA's will thus likely continue to develop increas(cid:173)
`ingly complex capabilities. PDA users will predictably
`develop greater reliance on their PDA for storing increasing
`amounts of highly sensitive information, including pass(cid:173)
`words, account numbers, confidential notes and scheduling
`information. Unfortunately, that information is readily avail(cid:173)
`able to whoever has possession of the PDA. In systems
`which require a password for access, the user must remem(cid:173)
`ber the password, and take the time to enter it, often on a
`suboptimal keyboard, and await verification, each time the
`device is turned on. Thus, despite the rapid advance of PDA
`capabilities, there remains a need for a security system that
`ensures that the device can only be utilized by the intended
`operator.
`
`SUMMARY OF THE INVENTION
`
`[0009] There is provided in accordance with one aspect of
`the present invention, a method of enabling a portable
`electronic device. The method comprises the steps of trans(cid:173)
`mitting an interrogation signal from the electronic device,
`and receiving the interrogation signal at an electronic key
`which is remote from the device. A password is transmitted
`from the key in response to receipt of the interrogation
`signal, and at least a portion of the functionality of the
`electronic device is enabled in response to receipt of the
`password. The device may comprise any of a variety of
`handheld electronic devices, such as PDAs, cellular tele(cid:173)
`phones, and portable computers. In one embodiment, the
`interrogation signal comprises an RF signal, and the pass(cid:173)
`word comprises a modified form of the interrogation signal.
`The key comprises a passive or active RF-ID circuit.
`
`[0010]
`In accordance with another aspect of the present
`invention, there is provided a portable electronic device
`security system. The system comprises a portable electronic
`device, having an interrogation signal transmitter associated
`therewith. An electronic key is provided remote from the
`device, having a password encoded within the key. The key
`transmits the password in response to an interrogation signal
`from the device, and at least a portion of the functionality of
`the device is enabled in response to receipt of the password.
`The key is provided with a support structure, for supporting
`the key on or by the user, apart from the electronic device.
`The support structure may comprise a tag, for attachment to
`an article of clothing, a wristband, a wristwatch, a wrist(cid:173)
`watch strap, belt clip, a pair of eyeglasses, a ring, a glove,
`or any of a variety of other personal items.
`
`[0011]
`In accordance with a further aspect of the present
`invention, there is provided a wireless personal preference
`control system. The system comprises an RFID circuit
`including an antenna, a memory and at least one preference
`password therein. A receiver is provided remote from the
`RFID, and electronics in communication with the receiver
`are provided for identifying the password and executing a
`preference in response to receipt of the password by the
`receiver.
`
`[0007] Although inconsistent with common usage, except
`where used differently herein, the present inventor intends
`the term PDA to generally include any of a wide variety of
`personal electronic devices such as handheld computers
`conventional PDA's and cellular telephones. Although cur-
`
`[0012]
`In one embodiment, the preference password may
`be modified or supplemented by the user. When the user
`passes within a predetermined operating range from the
`receiver, one or more passwords are retrieved from the RFID
`by the receiver, thereby enabling implementation of the
`
`Page 7 of 14
`
`

`

`US 2005/0151623 Al
`
`Jul. 14, 2005
`
`2
`
`preselected preferences. These preferences may include any
`of a variety of environmental conditions, such as selection of
`air conditioning, heating, music, or other aspects within a
`room. Alternatively, preferences such as computer log-on
`passwords, drawer locks, ergonometric relationships, light(cid:173)
`ing or other features of a computer workstation may be
`automatically established for a unique user in response to
`that user entering the area of the work station.
`[0013] Further features and advantages of the present
`invention will become apparent to those of ordinary skill in
`the art in view of the detailed description of preferred
`embodiments which follows, when considered together with
`the attached drawings and claims.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`[0014] FIG. 1 is a simplified block diagram of a personal
`security system or preference control system in accordance
`with the present invention.
`[0015] FIG. 2 is a further block diagram of a security or
`preference control system in accordance with the present
`invention.
`
`[0016] FIG. 3 is a perspective view of an RF-Key label
`which may be used in implementing the system of the
`present invention.
`[0017] FIG. 4 is an exploded perspective view of the label
`of FIG. 3.
`[0018] FIG. 5 is a partial perspective view of the label of
`FIG. 3, showing the first four layers.
`[0019] FIG. 6 is a cut away perspective view of the label
`of FIG. 3; and
`[0020] FIG. 7 is a sectional view of the label of FIG. 3,
`along the lines 7-7.
`
`DETAILED DESCRIPTION OF PREFERRED
`EMBODIMENTS
`
`[0021]
`In one application of the present invention, there is
`provided a security system for an electronic device.
`Although the security system may be utilized on relatively
`immobile electronic or electrically controlled devices, such
`as desk top computers, electrical equipment, motor vehicles,
`machinery, assembly or work stations and the like, the value
`of the present invention may be optimized in connection
`with providing security for mobile electronic devices. In
`another aspect of the invention, there is provided a personal
`preference coordinator, for communicating preset personal
`preferences from a memory device associated with a user, to
`external electronic devices in the user's surrounding envi(cid:173)
`ronment.
`[0022] The electronic security system provides a wireless
`method of enabling handheld electronic equipment only
`when in the hands of or immediate vicinity of an authorized
`user, and disabling the electronic equipment when access or
`operation is attempted by someone other than an authorized
`user.
`[0023] This security system may find particular applica(cid:173)
`tion for devices such as personal digital assistants (PDA's,
`cellular telephones, and other devices) in which the value of
`the content and insuring its security often vastly exceeds the
`value of the hardware. The basic system thus includes an
`
`electronic device for which personal security is desired,
`on-board circuitry for transmitting an interrogation signal
`and receiving a return password from a remote electronic
`key, and the remote electronic key. These features will be
`described in greater detail below.
`[0024] Referring to FIG. 1, there is illustrated a block
`diagram which, in schematic form, illustrates the basic
`components of a security system in accordance with the
`present invention. An electronic device 10 is provided with
`wireless electronic lock circuitry 12. The wireless electronic
`lock circuitry can be built into the original electronic device
`10 at the point of manufacture, or can be mounted as an after
`market accessory to be attached to the electronic device 10
`in any of a variety of ways depending upon the housing,
`electronic configuration and available communication ports
`of electronic device 10.
`[0025] The wireless electronic lock circuitry 12 includes a
`computer or other processor 14 having a memory therein.
`The computer 14 is in electrical communication with an
`interrogation signal transmitter 16. A signal receiver 18 is
`also provided, which may include the same antenna and
`other overlapping components as the interrogation signal
`transmitter 16 as is understood in the art. The signal receiver
`18 is in electrical communication with the computer 14, for
`interpreting the signal received.
`[0026] A remote key 20 is adapted to be carried by an
`authorized user, as is discussed below. The remote key 20 is
`configurated to receive an interrogation signal from the
`interrogation signal transmitter 16, and transmit a password
`22 in response to receipt of the interrogation signal. As used
`herein, "key" and "RF-Key" are used interchangeably.
`Although the presently preferred embodiment utilizes an RF
`signal, the invention is not limited to a particular commu(cid:173)
`nication modality. Other wireless means for communicating
`a password may also be used, such as light, including IR, UV
`or visible from a laser or other source. Acoustic and elec(cid:173)
`trostatic communication may also be used.
`
`[0027]
`In one embodiment, the interrogation signal and
`responsive password are transmitted through the body of the
`user. This mode of password communication may be desir(cid:173)
`able in applications where the user is required or it is
`convenient for the user to physically touch a surface to allow
`signal transmission. In this implementation, a conductive
`surface on the remote key 20 is in capacitative communi(cid:173)
`cation with the user's body at a first location, (e.g., the foot,
`hand, arm, abdomen, etc.) and the device 10 is provided with
`a surface for communicating with the user's body at a
`second location such as the hand in which the device is held
`during normal operation. Capacitative coupling to transmit
`data through a user's body is disclosed, for example, in U.S.
`Pat. No. 6,211,799, the disclosure of which is incorporated
`in its entirety herein by reference.
`
`[0028] The password 22 is received by the signal receiver
`18, and processed by the computer 14 to identify whether the
`password 22 is authorized for use on the security system. If
`the password 22 is authorized, the computer unlocks the
`electronic device 10 either wholly or partially, such as by
`enabling power to the electronic device and/or enabling the
`operation of one or more features on the electronic device
`which were subject to the security system. In one preferred
`implementation of the present invention, the electronic
`device comprises any of a variety of handheld electronic
`
`Page 8 of 14
`
`

`

`US 2005/0151623 Al
`
`Jul. 14, 2005
`
`3
`
`devices which contain memory or functions which are
`desired to be kept confidential. These include devices such
`as cellular telephones, PDA's, notebook, laptop and desk top
`computers, and others as will be apparent to those of skill in
`the art in view of the disclosure herein.
`[0029] The processor 14 can control operation of the
`device 10 in any of a variety of ways, as will be understood
`by those of skill in the art. For example, through a simple
`transistor switch or other known circuitry, the processor can
`open or close the power circuit within the device 10. In one
`operating mode, the "normal" power on button for the
`device 10 is depressed, sending power to the interrogating
`signal transmitter 16 which instantly transmits an interro(cid:173)
`gation signal 17. If an RF-Key is within range, and sends
`back an authorized password, the switch is closed by con(cid:173)
`troller 29 thereby powering on the device 10. A known latch
`circuit can be utilized, to maintain the power circuit closed,
`until the power for the device 10 is manually turned off. If
`no appropriate password is received while the power button
`is depressed, the switch controlled by controller 29 remains
`open thereby preventing the device 10 from powering on.
`[0030]
`In a further option, the transmitter 16 is pro(cid:173)
`grammed to retransmit the interrogation signal at least one
`additional time following activation of the device. If the
`authorized RF-Key is no longer within range, the device 10
`and/or specified secure functions are disabled. The retrans(cid:173)
`mission can occur periodically, such as at least once every
`10 minutes or more, at least once every 5 minutes or at least
`once per minute, to ensure that the device will automatically
`be disabled once it leaves the proximity of the authorized
`user
`[0031] The security system can be used to enable or
`disable all or only some of the functions of the device 10.
`Partial enablement requires a more complex integration
`between the controller 29 and the device 10, but should be
`well within the level of ordinary skill in the art. For example,
`one or more functions on a PDA such as the memo pad or
`telephone list may be enabled in the presence of an RF-Key
`and disabled if outside of the read range from the corre(cid:173)
`sponding RF-Key. An unauthorized user (i.e., someone
`without the unique RF-Key which contains the enabling
`password) can operate all functions on the PDA except the
`memo pad, telephone list or other secure functions.
`
`[0032] Although the RF-Key security system of the
`present invention is not immune from breach by a skilled
`"hacker", the probability that the typical PDA thief could
`gain access to secure data should be quite low. For example,
`a typical passive RF-Key will reserve 39 bits of memory for
`the password code. That translates to about 550 billion
`possible unique codes.
`[0033] The RF-Key 20 is preferably in the form of a small,
`concealable device which may be carried by the user apart
`from the electronic device 10. The RF-Key 20 may take the
`form of a patch or tag having appropriate electronic circuitry
`contained therein, as will be described below. This RF-Key
`20 may be concealed in or attached to a wrist watch or wrist
`watch band, wallet, eyeglasses, belt, key chain, gloves, pen
`or pencil, or any of a variety of other portable devices which
`a person who desires security would likely carry. The
`RF-Key 20 may be attached to clothing such as by clipping,
`pinning, stitching, and the like, or may be worn as a hang tag
`on a wrist band or neck chain, or placed in a wallet or pocket.
`
`It can be in the form of a flexible patch which is adhesively
`adhered to the skin like a small Band-Aid. It can also be
`concealed in jewelry, such as rings, bracelets, earrings,
`necklaces, pins and the like.
`[0034]
`In use, the interrogation signal transmitter 16 and
`RF-Key 20 must be within a predetermined operating dis(cid:173)
`tance (read range) of each other in order for the RF-Key 20
`to transmit a password 22 in response to an interrogation
`signal 17 from the interrogation signal transmitter 16. The
`operating distance will be a relatively short personal space
`distance, such that once the electronic device 10 is carried
`outside of the operating distance from the RF-Key 20, the
`electronic device 10 will be fully or partially disabled.
`[0035] For most applications, operating distances of no
`more than about six feet, and often no more than about three
`feet may be used. Read ranges for certain passive RF-Key
`systems useful in the present invention, such as for PDA's,
`are less than two feet and often in the range of from about
`six inches to about 18 inches
`[0036]
`In a preference control circuitry application, the
`wireless electronic lock circuitry 12 may be attached to a
`land based structure or device, such as mounted on a wall,
`in a door frame, ceiling, computer work station, assembly
`line or other work station, in an automobile, or other location
`where a user is likely to reside or pass by. The wireless
`electronic lock circuitry 12 is then utilized to enable or
`adjust to a preference any of a variety of functions, such as
`environmental controls or electronic device preferences
`which are preset by the user. Thus, the user who carries an
`RF-Key 20 which has been preprogrammed with the user's
`preferences will pass within a predetermined distance of at
`least an antenna portion of the wireless electronic lock
`circuitry 12, and thereby enable the electronic device 10 in
`accordance with the predetermined preference. These pref(cid:173)
`erences may include opening automatic doors, unlocking
`locks, adjusting lighting, adjusting environmental features
`such as temperatures or humidity, selecting musical prefer(cid:173)
`ences, adjusting mechanical preferences such as car seat
`heights, positions of mirrors, customization of workstation
`ergonomics such as chair adjustments, arm rests, mouse pad
`angles, carpal tunnel syndrome pads, monitor and keyboard
`locations, adjustment of equipment such as manufacturing
`or testing devices, selecting airline preferences such as meal
`and movie choices and the like.
`[0037] Alternatively, the preference control circuitry may
`be utilized to power on or off any of a variety of electronic
`equipment such as computers, personalized content man(cid:173)
`agement on web sites or search engines, operation of ATM
`machines, testing or manufacturing machines and the like.
`Thus, although the present invention will be primarily
`described below in connection with the application of an
`RF-Key 20 for enabling wireless electronic devices such as
`PDA's and cell phones when in the hands of the holder of
`the RF-Key 20, the security or preference setting system of
`the present invention may be utilized in a variety of addi(cid:173)
`tional contexts as will be apparent to those of skill in the art
`in view of the disclosure herein.
`[0038] When used in the preference control embodiment,
`the system of the present invention will often control more
`than one preference, such as two or four or six or more
`preferences. For example, in the environment of a computer
`workstation, the RF-Key may be programmed with a par-
`
`Page 9 of 14
`
`

`

`US 2005/0151623 Al
`
`Jul. 14, 2005
`
`4
`
`ticular user's computer log on name, password, one or more
`adjustments to the physical configuration of the workstation
`(monitor height relative to chair height, keyboard orienta(cid:173)
`tion, lighting, music, etc.) or other features that might be
`adjusted between users of the same station.
`[0039] The RF-Key may be provided with a plurality of
`electric contacts which may be removably placed in elec(cid:173)
`trical communication with a programming computer, such as
`by positioning the RF-Key within a cradle or slot wired to
`a computer. Software then prompts the user to select from an
`array of available preferences displayed on the monitor, and
`then send the users selection of preferences to the RF-Key.
`In this manner, the user can customize the preferences stored
`in the RF-Key as may be desired from time to time, such that
`the most recently selected preferences will be expressed
`when the user moves into proximity of the interrogation
`signal transmitter ( and thus the work station or other enabled
`location).
`[0040]
`In a preference control application, the passive or
`active RF-Key can readily be built directly into a PDA, cell
`phone or other device that the user is likely to carry such as
`any of those identified above. If built into the cell phone or
`PDA, for example, the preferences can be set directly on the
`PDA keypad, or on a personal computer and then down(cid:173)
`loaded into the PDA through a HotSync connection as is
`known in the art. The PDA then essentially becomes an
`automatic remote control for setting personal preferences on
`any of a wide variety of preference enabled devices,
`examples of which are listed elsewhere herein, which the
`user might encounter throughout the day.
`[0041]
`In another application of the invention, the system
`can be used to enable access or functions remotely in a
`secure, on demand fashion. For example, a worker or other
`person in a building or out in the field may require access to
`a locked door or device to which that person does not
`routinely need access or is otherwise restricted from routine
`use. That person can call from an enabled cell phone to a
`controller. If access is deemed appropriate, the controller can
`remotely program the Key in the cell phone with the access
`code, which will now provide access when the person
`( carrying the cell phone) moves within the operating dis(cid:173)
`tance from the device to be enabled. The cell phone can be
`either permanently or temporarily (e.g., one time use,
`weekly or monthly "pass") enabled, in the discretion of the
`controller. This allows the controller to provide access
`without revealing the password, and also allows computer(cid:173)
`ized tracking of who had access to secure functions or
`locations at any time. Creation of software for this and other
`applications disclosed herein should be well within the level
`of ordinary skill in the art in view of the disclosure herein.
`[0042] Certain additional aspects of a simple RF-Key
`system in accordance with the present invention will be
`appreciated by reference to FIG. 2. As illustrated therein, an
`RF-Key tag will generally have a radio frequency (RF)
`transmitter, an RF receiver, an RF modulator, and a memory.
`The memory retains the digital code manifesting the iden(cid:173)
`tification number. The RF modulator extracts the digital
`code representing the identification number as a modulated
`signal which is applied to the RF transmitter. The RF
`receiver receives interrogation and control signals which
`manifest a request for the identification number.
`[0043] Referring to FIG. 2 the RF-Key communication
`system 26 includes an interrogator 27 and an RF-Key tag 28.
`
`The interrogator 27 includes a host controller 29 to process
`received information from the RF-Key tag 28 via antenna 30
`and receiver 31. To retrieve information from the RF-Key
`tag 28, the host controller 29 generates an interrogation
`command signal which is transmitted by transmitter 32 and
`antenna 33 as signal 34. The tag 28 transmits RF-Key signal
`35 via antenna 36 in response to receipt of the interrogation
`command signal 34. The receiver 31 receives the signal 35
`via antenna 30. The signal 35 manifests the identification
`number of the tag 28.
`[0044] The RF-Key tag 28 has an antenna 36 and a
`receiver 38 to receive the interrogation command signal 34
`from the interrogator 27. The receiver 38 transfers the
`received command signal to a controller 40. The controller
`40 interprets the command and extract the corresponding
`identification number (ID) from memory 42. The extracted
`identification number is then transferred by the controller 40
`to transmitter 44 which transmits the ID to antenna 36 which
`broadcasts the signal 35.
`In active RF-Key tags, power 46 is provided by a
`[0045]
`battery system. In passive systems, the power is induced
`from the received signal. The signal 35 transmitted by the
`RF-Key tag 28 is modulated back scatter of the original
`signal transmitted by the interrogator 27.
`
`[0046] The controller 40 may have an interface, not
`shown, to receive data from external transponders such as
`temperature sensors, pressure sensors, global positioning
`sensing and other telemetric measurement data.
`
`[0047] When multiple RF-Key tags 28 are simultaneously
`in close proximity to the interrogator 27 and the interrogator
`27 is broadcasting interrogation and control signals, the
`RF-Key tags may simultaneously respond. The responses
`may collide and the identification codes may be garbled and
`lost. Generally, the interrogator will rebroadcast commands
`to establish an order of broadcast of the RF-Key tags. This
`ordering of the broadcast is generally possible only from
`active RF-Key tags.
`
`[0048] A variety of circuits are known, which can be
`adapted by those of skill in the art for use in the security
`systems or preference control systems of the present inven(cid:173)
`tion. For example, U.S. Pat. No. 5,479,160 to Koelle,
`incorporated by reference herein, discloses an inexpensive
`circuit that consumes low power, can detect low level RF
`signal and RF signals of varying strength, and can reject
`intermittent low level RF interference. Logic circuitry is
`provided to insure that the read/write circuitry of the tag will
`not be activated unless the polarity of the reactivation signal
`is detected for a specified time.
`
`[0049] U.S. Pat. No. 5,541,604 to Meier, incorporated by
`reference herein, discloses the use of a single set of circuitry
`in each of the interrogator and the transponder for transmis(cid:173)
`sion and reception of both powering and communication
`signals, without the need for synchronization between inter(cid:173)
`rogators. PWM (pulse width modulation), PPM (pulse posi(cid:173)
`tion modulation) and FSK (frequency shift keying) trans(cid:173)
`mission systems are disclosed.
`
`[0050] U.S. Pat. No. 5,485,154 to Brooks et al, incorpo(cid:173)
`rated by reference herein, discloses systems and methods of
`communicating with or identifying more than one remote
`device employing random sequence selection of a carrier
`signal frequency from a defined set of carrier frequencies.
`
`Page 10 of 14
`
`

`

`US 2005/0151623 Al
`
`Jul. 14, 2005
`
`5
`
`The remote device selects a carrier signal frequency and
`transmits data such as an identification code using that
`frequency and then reselects the same or a new carrier signal
`frequency for the next transmission event.
`
`[0051] The RF-Key tag can be manufactured in any of a
`variety of ways, as will be recognized by those of skill in the
`art. One example of a low profile, laminated RF-Key is
`discussed in connection with FIGS. 3-7, below.
`
`[0052] Referring to FIGS. 3, 4, and 7, a laminated RF-Key
`label 110 has five layers 114, 116, 118, 120, and 122, and
`forms a protective cavity 126 for RF-Key circuitry in the
`form of an IC chip 130. One of the layers 122 defines the
`cavity 126 for the IC chip 130, which is electrically con(cid:173)
`nected to an antenna 124. The label 110 may be encapsulated
`or receive additional protective or functional layers 128
`suitable for specific applications.
`
`[0053] Referring to FIGS. 4 and 7, the first layer 114 is an
`adhesive material which is deposited on a release liner 132.
`The release liner is preferably a silicone coated paper.
`However, any of a variety of liners having releasable prop(cid:173)
`erties may be used. By forming the label 110 on the release
`line