An embodiment relates generally to the field of Radio Frequency Identification (RFID). More particularly, an embodiment relates to a method and a system for activating and powering RFID tags and labels.
RFID is a type of automatic identification system for tracking and identifying an item. A RFID system consists of a RFID reader, a RFID tag attached to or embedded into the item to be tracked and optionally a host computer. The RFID reader is a device consisting of an antenna packaged with a transceiver and a decoder. Similarly, the RFID tag includes an integrated circuit combined with an antenna. The RFID reader tracks the RFID tags by emitting radio frequency waves and thereby activating the RFID tag which is within range of the RFID reader. The RFID tag responds by sending data back to the RFID reader which optionally transfers the data to the host computer for further processing.
In general, the RFID tag may be classified as passive, active or semi-active. A passive tag is a RFID tag that does not contain a battery. The power is supplied by the RFID reader. When radio waves from the RFID reader are encountered by a passive RFID tag, the antenna within the RFID tag interacts with an electromagnetic field. The RFID tag draws power from the field to operate the circuits in the RFID tag. As the RFID tag functions without a battery, the lifetime of the tag can be long. Such RFID tags are also less expensive to manufacture and smaller in size. However, the RFID tags can be read only at very short distance and is hence, limited in its applications. In addition, it may not be possible to include sensors that require electricity for power.
An active RFID tag is equipped with a battery that can be used as a partial or complete source of power for the RFID tag's circuitry and antenna. The battery may be replaceable or non-replaceable. An active RFID tag can be read at a longer distance, hence, greatly improving the utility of the device. In addition, the RFID tag may be equipped with other sensors that require electricity. However, the usage of such RFID tag is limited by the lifetime, cost and weight of the battery.
A semi-active RFID tag uses a hybrid of energy from the radio waves of RFID reader and battery. In general, battery power is used for operating local circuitry while power from the radio waves of RFID reader is used for communicating with the RFID reader. Like the active RFID tag, the semi-active RFID tag is limited by the lifetime of the battery.
An active RFID tag and a portable RFID reader may be used to locate an object which includes the active RFID tag. An example of such a system is the Loc8tor system; see www.loc8tor.com. The Loc8tor handheld can find an active RFID tag from a distance of up to 600 feet. The Loc8tor handheld provides a user interface which shows the distance (and direction) of the RFID tag relative to the Loc8tor handheld. The RFID tag in the case of the Loc8tor system is also limited by the battery life of the tag's battery.
According to one aspect of the invention, there is provided a label for attaching to an object to be located, the label including at least one integrated circuit (IC) containing information relating to the object, an antenna coupled to the IC for communicating the information relating to the object with an object locating device, such as a portable RFID reader, and one or more powering devices to provide electrical energy to the integrated circuit, wherein the integrated circuit is capable of selecting at least one of the one or more powering devices, wherein the one or more powering devices include a rechargeable battery and a solar power device which recharges the rechargeable battery. The label may be less than about 2.0 mm in thickness, and the rechargeable battery may be a printed rechargeable battery, and the information in the IC may be programmable through a programming operation in the object locating device. In an alternative embodiment, the IC may contain information which is fixed and not programmable (e.g. a fixed 32 or 64 bit code) and the object locating device is programmable to associate a name (e.g. Chris's 9 iron golf club) with a particular code in the information in an IC so that the IC (and the object it is attached to) can be located by selecting the name, associated with that IC, on the object locating device.
The IC in the label may include RFID circuitry and power regulating circuitry and recharging circuitry; the power regulating circuitry and recharging circuitry may control charging of the rechargeable battery by the solar power device. The power regulating circuitry may also control modes of power consumption, for example, “sleep”, “on” and “off” modes. The object locating device may be a portable RFID reader which transmits only one identifier at a time in order to locate only one object having the identifier. The plurality of powering devices may further include a non-rechargeable battery coupled to the IC; the non-rechargeable battery in this case may provide power to the IC while the solar power device recharges the rechargeable battery.
In one embodiment, a method to activate a label (e.g., RFID tag) from an “off” mode in response to receiving an activating signal is disclosed. The activating signal may be, for example, a radio frequency (RF) signal, light, and the like. The label may include an integrated circuit and one or more powering devices coupled to the IC. The one or more powering devices may include, for example, a rechargeable battery, a solar power device, a non-rechargeable battery, or any combination thereof. In one embodiment, a power from at least one of the one or more powering devices is provided to the integrated circuit in response to receiving of the activating signal. In one embodiment, the activating of the label from the “off” mode includes placing the integrated circuit into a “low power” mode, e.g., a “sleep” mode.
In one embodiment, the label (e.g., a RFID tag) is disclosed that includes an integrated circuit (IC) containing an information relating to an object, an antenna coupled to the IC to receive a radio frequency (RF) signal, and one or more powering devices coupled to provide power to activate the integrated circuit from the “off” mode. In one embodiment, the IC may comprise a power activating device that acts in response to receiving an activating signal, e.g., a radio frequency signal, to activate a microprocessor, and a power regulating and recharging circuitry coupled to the microprocessor. The microprocessor is configured to control a power regulating and recharging circuitry that operates to provide power to IC. In another embodiment, the IC comprises a microprocessor coupled to one or more powering devices. The microprocessor is configured to be directly activated in response to receiving an activating signal, e.g., light, by a powering device, e.g., a solar power device. The microprocessor is further configured to control a power regulating and recharging circuitry that operates to provide power to the IC.
In one embodiment, a label is in an “off” state until activated by a device, for example, an object locating device. In one embodiment, a user can turn the label “on” by activating the label with the device, for example, a handheld device. In one embodiment, the activation may be accomplished by sending a radio frequency signal to the label. Next, an antenna on the label receives the signal from the device. The received signal provides energy to activate the label. In one embodiment, once activated, the label may perform a registration operation with the device, e.g., the label may exchange its unique code with the device. This “registration” of the label may provide the device with a unique identifier for the label. In one embodiment, a user can select a label to search from a list of stored unique identifiers in the device. In one embodiment, when the user selects a unique identifier the device transmits a signal with the code.
In one embodiment, the label transmits a response, which indicates a match, if transmitted data from the object locating device represents the information stored in the IC; a match response from the IC causes the object locating device to present a user interface, such as an audio sound and/or a displayed graphic which represents a received signal strength indication (RSSI), which indicates a location of the label (containing the IC) relative to the object locating device. The user interface may include an indication of range or distance to the object and an indication of the direction (e.g. in azimuth) of the object. If the transmitted data from the object locating device does not represent the information stored in the IC, then the IC does not transmit a response indicating a match.
In an alternative embodiment, a RFID tag can turn itself “on” from an “off” state when exposed to light. A device, for example, a RFID reader, may be used as a reader that can recognize all RFID tags. A portion of the embedded code associated with the RFID tags may include a generic code. The device, for example a “master” reader, can recognize the generic code and locate all tags.
In one embodiment, several unique labels, each storing a unique (or quasi-unique) code, are applied to a set of golf clubs of a user. The user may either carry the object locating device (e.g. in the user's pocket) or attach the device on a golf cart or golf bag. The object locating device may be used to alert the user if a golf club is lost by presenting an alert (e.g. an alarm sound) if the golf club is beyond a predetermined distance (as measured, for example, by RSSI) or if the golf club is missing (e.g. not within a predetermined distance) for a predetermined period of time. The object locating device may repeatedly transmit a series of codes one at a time, each code corresponding to one of the IC's on one of the golf clubs in the set of golf clubs. If an RSSI for one of the codes is too low, then the object locating device issues an alert.
In another embodiment, a device, for example, the object locating device, and/or a RFID reader that is configued to transmit activation signal to a RFID label and/or a RFID tag, is incorporated into a personal device, for example, a mobile phone.
In one embodiment, a RFID label and/or RFID tag is configured to be attached to a golf club, a radio controlled device, e.g., a model radio controller car, a plane, a model rocket, hunting device, e.g., an arrow, and other objects that may need to be located. In yet another embodiment, a RFID label and/or RFID tag may be configured to be installed on a windshield of an automobile.
Other features of the invention will be apparent from the accompanying drawings and from the detailed description that follows.
An embodiment of the present invention is illustrated by way of example and not limited in the figures of the accompanying drawings in which like references indicate similar elements and in which:
The subject invention will be described with references to numerous details set forth below, and the accompanying drawings will illustrate the invention. The following description and drawings are illustrative of the invention and are not to be construed as limiting the invention. Numerous specific details are described to provide a thorough understanding of the present invention. However, in certain instances, well known or conventional details are not described in order to not unnecessarily obscure the present invention in detail. It will be evident, however, to one skilled in the art that the present invention may be practiced without these specific details.
Reference throughout the specification to “one embodiment,” “another embodiment,” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, the appearance of the phrases “in one embodiment” or “in an embodiment” in various places throughout the specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.
The present invention presents, in one embodiment, a method and a system for providing electrical energy to a RFID tag with an efficient and renewable energy source, such as solar energy, according to one exemplary embodiment.
One common problem of a prior RFID system relates to reader collision and tag collision. Reader collision occurs when the coverage area of one RFID reader overlaps with that of another RFID reader. Reader collision leads to signal interference and multiple reads of the same tag. On the other hand, tag collision occurs when more than one RFID tag reflects back a signal at the same time, thereby confusing the RFID reader.
In one exemplary embodiment, the present invention avoids tag collision by associating a unique code with each RFID tag 2 and by attempting to read only one tag at a time by transmitting a unique code for a given tag at a time. Separate time slots are reserved for each code and hence each tag. Therefore, the RFID tag 2 will only be activated when it hears its own unique code from the RFID reader. Although the RFID reader 3 communicates with one RFID tag 2 at any one time, it is well known that each communication process takes only milliseconds and appears that all the RFID tags 2 are being read nearly simultaneously.
In another embodiment, the RFID tag can operate in a plurality of modes of power consumption, e.g., “sleep”, “on” and “off” modes. For example the RFID tag may turn itself on from an “off “state in response to an activation signal, as described in further detail below. Referring to
It will also be noted that in at least one embodiment of the present invention, the RFID tag 2 is designed to comprise three energy sources (4, 10 and 12). The first powering device 4 may include a solar cell layer which converts solar energy into a usable amount of electrical power such as direct current electricity. In one embodiment, the first powering device 4 is configured to charge the second powering device 10 which is a rechargeable battery. An example of such low profile (or “thin film”) rechargeable energy cell may be solid state Lithium and Lithium-ion battery technology developed by Oak Ridge National Laboratory, located in Oak Ridge, Tenn. The third (optional) powering device 12 is a primary or disposable battery, such as a Lithium battery which is non-rechargeable. In addition, the powering devices (4, 10 and 12) may be an ink-based energy cell. Such printed power source is well known for its ultra-low profile design which is usually less than 1 millimeter in thickness, lightweight and flexible. An example of such low profile energy cell may be based on a standard zinc anode, manganese dioxide cathode structure, and an electrolyte printed onto a flexible paper or polymer substrate.
The selection of which powering devices (4, 10 and 12) to use may be performed by the integrated circuit (IC) 6. For example, the integrated circuit 6 is configured to select the source of electrical energy based on the “sleep” or “talk” modes of the RFID tag 2. In the “sleep” mode, the RFID tag 2 listens for an activation signal of a RFID reader. In the “talk” mode, the RFID tag 2 exchanges data with the RFID reader. The RFID tag 2 consumes more electrical energy in the “talk” mode than in the “listen” mode.
In another configuration, the RFID tag 2 may draw its electrical energy from the first powering device 4 when it is in the “sleep” mode. In addition, the RFID tag 2 uses the second powering device 10 when the integrated circuit 6 detects that the first powering device 4 is non-functioning. For example, when the RFID tag 2 is in darkness and light energy is unavailable to activate the solar cell layer (first powering device 4) then the second or third powering devices 10 and/or 12 may provide power to the IC 6. In the event that the energy from the second powering device 10 is depleted, the RFID tag 2 utilizes the third powering device 12.
Stated differently, the RFID tag 2 is powered by solar cell layer (first powering device 4) in the “sleep” mode. And when the RFID tag 2 is in storage where light is unavailable, the rechargeable battery (second powering device 10) supplies energy to the RFID tag 2. If the RFID tag 2 is in storage for an extended period of time, the primary battery (third powering device 12) replaces the rechargeable battery (second powering device 10) as the source of electrical energy. When sufficient light is available to activate the solar cell, then the solar cell may recharge the rechargeable battery.
When the RFID tag 2 is in the “talk mode”, the RFID tag 2 may utilize electrical energy from the second powering device 10 or/and third powering device 12.
It can be seen, from this description, that the use of electrical energy from the first, second or third powering devices (4, 10 and 12) is subject to different factors, such as requirements of the uses of IC 6 or conditions of the environment. In addition, the RFID tag 2 may be configured to utilize electrical energy from a single or multiple powering devices (4, 10 and 12) at any one time. In another embodiment, the third powering device 12 (primary battery) may not be required.
A further embodiment of the integrated circuit 6 is illustrated in
As shown in
In one embodiment, power activating device 424 connects one or more powering devices 440, 412, and 410 to provide power to microprocessor 426, as shown in
Next, another one or more RF pulses are received by antenna 480. The another one or more RF pulses contain identifier information to locate an RFID label and/or tag. The microprocessor 426 checks the identification information being sought. For example, microprocessor 426 checks if the received identification information matches with the identification information that is stored in a memory (not shown) coupled to microprocessor 426. If the received identification information matches with the identification information stored in the memory, label 400 switches to a “full power” mode (turns on fully). Next, another RF signal having the identification information can be transmitted by integrated circuit 460 through antenna 480 to register the label 400. In one embodiment, if the identification information stored in the memory of the label 400 does not match with the received identification information, the microprocessor 426 returns to a “sleep” mode. In another embodiment, if the identification information stored in the memory of the label 400 does not match with the received identifier information, the microprocessor 426 returns to the “off” mode.
In an embodiment, a label (e.g., label 400 or label 500 depicted in
Once activated, the label will exchange its unique code with the device. This “registration” of the label provides the device with a unique identifier for the label. The user can select a label to search from a list of stored unique identifiers in the device. When the user selects a unique identifier the devices transmits a signal with the code. The label transmits a response, which indicates a match, if transmitted data from the object locating device represents the information stored in the IC; a match response from the IC causes the object locating device to present a user interface, such as an audio sound and/or a displayed graphic which represents a received signal strength indication (RSSI), which indicates a location of the label (containing the IC) relative to the object locating device. The user interface may include an indication of range or distance to the object and an indication of the direction (e.g. in azimuth) of the object. If the transmitted data from the object locating device does not represent the information stored in the IC, then the IC does not transmit a response indicating a match.
Antenna 580 may be used to receive from and transmit RF signals to another device, e.g., an object locating handheld device. Initially, label 500 may be in an “off” mode without drawing any electrical power from any of powering devices 540, 520, and 510. Label 500 can turn itself on from an “off” state when exposed to light. In one embodiment, solar cell 540 is exposed to light, and converts the light signal into electrical signal. The electrical signal provided by solar cell 540 turns on microprocessor 541. In one embodiment, the electrical signal provided by solar cell 540 places microprocessor 541 into a “low power” mode from “off” mode. Next, one or more RF pulses may be received by antenna 580 after the microprocessor is turned on by light. The one or more RF pulses contain identifier information to locate an RFID label and/or tag.
The one or more RF pulses may be provided by the object locating device 3, e.g., an RFID reader, depicted in
Next, an RF signal having an identification information can be transmitted by integrated circuit 543 through antenna 580 to register label 500. In one embodiment, if the identity of the label 500 does not match with the received identifier information, the microprocessor 541 returns to a “sleep” mode. In one embodiment, integrated circuit 543 includes a timer (not shown) to control the duration of a “sleep” mode. In another embodiment, if the identity of the label 500 does not match with the received identifier information, the microprocessor 541 returns to the “off” mode. 100511 In one embodiment, the object locating device, e.g., the RFID reader, can be a reader that can recognize all RFID tags. In one embodiment, a portion of the embedded code associated with the RFID tag includes a generic code. The object locating device, e.g., such as a “master” reader, can recognize the generic code and locate all tags and/ or all labels. One application of this embodiment is in emergency location applications, such as a lost hiker or skier. There are a multitude of applications of the RFID tag and reader detailed, including but not limited to incorporating the RFID reader into a personal device, such as a mobile phone. Other applications include installing the RFID tag on the windshield of an automobile, and using the RFID tag on hunting arrows.
The powering devices in the RFID tag and/or labels are controlled by the power regulating circuit which is controlled by a microprocessor. The power regulating circuit can control various modes of power consumption. These modes can be predetermined at the time of manufacture and programmed into the microprocessor in the RFID tag. In an alternative embodiment, a variety of modes can be stored in the microprocessor and the user would specify which mode to use. The encoded communication from the device, such as a handheld device, with the RFID tag would transfer the required information to specify mode of operation to the RFID tag.
Examples of power consumption modes include, but are not limited to powering the RFID tag from an “off” mode to “on” or “sleep” mode, returning the tag to “off” mode, and various timings associated with “on” and “sleep” modes. The “sleep” mode can include a timer that activates the device to “listen” for an incoming signal from a device at a predetermined amount of time.
In one embodiment, the label may receive one or more RF pulses from an object locating device that contain identification information while listening. The label may check if the identification information stored in a memory of the label matches to the identification information contained in the one or more RF pulses. If the identification information stored in the memory of the label matches to the identification information contained in the one or more RF pulses, the label is switched to “on” or “talk” mode. As shown in
While listening, the label may receive one or more RF pulses from an object locating device that contain identification information. The label may check if the identification information stored in a memory of the label matches to the identification information contained in the one or more RF pulses. If the identification information stored in the memory of the label matches to the identification information contained in the one or more RF pulses, the label is switched to “talk” mode. As shown in
In one embodiment, if the identification the identification information of the label does not match to the identification information from the object locating device, the label turns to “sleep” mode, or “off” mode, as described above.
Thus, a method and a system for activating and powering RFID tags and/or labels have been described. Although the present invention has been described with reference to specific exemplary embodiments, it will be evident that various modifications and changes may be made to these embodiments without departing from the broader spirit and scope of the invention. Accordingly, the specification and drawings are to be regarded in an illustrative rather than a restrictive sense.
This application claims the benefit of the filing dates of U.S. Provisional Applications 60/850,993, filed on Oct. 10, 2006, and 60/876,714, filed on Dec. 21, 2006, and both of these applications are incorporated herein by reference.
Number | Date | Country | |
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60850993 | Oct 2006 | US | |
60876714 | Dec 2006 | US |