Security device and alarm system

A security device and alarm system includes a reader preferably concealed in a fabric article, at least one tag, and an alarm unit. The reader includes a reader transmitter, reader receiver, CPU, power source, and power switch. The tag includes a tag transmitter and a tag receiver. If using active RFID tags, each tag includes a power source. The alarm unit includes an alarm receiver, alarm, and power source. If the reader receiver does not receive an appropriate reply from the tag transmitter after the reader transmitter sends a query to the tag receiver, or if the reader was deactivated, the reader transmitter sends an alarm signal to the alarm unit. Upon the alarm receiver's receipt of the alarm signal, the alarm is energized. If using multiple active RFID tags, the CPU checks for each through tag transmission identifiers, and the alarm identifies the missing tag through unique alarm signals.

BACKGROUND OF THE INVENTION

This invention relates generally to a security device. In particular, the present invention relates to an anti-theft security device and alarm system.

Security devices are a part of doing business today. The low cost and obvious benefit of anti-theft measures make them used even on objects of small value in department and retail stores. However, rare objects and collectibles are often found unprotected in today's marketplace. This is partly the result of the decentralized nature of the antique business, trade shows, festivals, and similarly operated businesses in which there are many operators of independent booths in a single area. An anti-theft measure addressing the needs of decentralized merchants would be a welcome addition to their professions. Specifically, an alarm system is needed that provides warning when a dealer's property is moved.

Many stores utilize AM (acousto-magnetic) tags. Wide entrances can be covered, and the tags themselves are inexpensive. A transmitter is set near the area to be monitored (usually on one side of the store's door) and sends out intermittent pulses of radio waves. The material the tag is made of actually expands and contracts in size in the presence of this radio field. If the transmitter is operating at the correct frequency, the tag resonates like a tuning fork and produces a radiated signal that continues in between the pulses of radio waves. A receiver set to correspond to the transmitter (usually on the opposite side of the store's door, so that everything must pass between the transmitter and receiver when leaving) listens for this vibration to sense a tag. This system cannot distinguish multiple tags, however, and is poorly suited for monitoring multiple booths or areas without tightly controlled exits.

The most commonly used anti-theft systems in stores are swept-RF systems, mostly due to their extremely low cost. In these systems, a tag is little more than a simple transmitter circuit and a flexible aluminum antennae printed on a paper backing. When an item is purchased, a high-energy burst of radio energy is delivered in close proximity to the tag. This burns out the circuitry and deactivates the tag. Receivers are positioned at the stores' exits to detect active tags. However, like the AM systems described above, swept-RF is unable to distinguish multiple tags. It also suffers from being poorly suited for monitoring multiple booths or areas without tightly controlled exits.

The fastest rising trend in security products is RFID (Radio Frequency Identification). Essentially, a stationary reader sends out a radio signal of a particular frequency. The tag responds to this signal by “replying” in a way that alerts the reader that a tag has just entered its range. This information can then be used to draw conclusions about the location of the tagged object. If a theft is suspected, an alarm can be triggered. In passive RFID systems, the tag does not require a battery. Instead, the energy of the reader signal provides the energy necessary to reply. The circuitry required is exceedingly small—not much bigger than a grain of rice. These devices can also be very unobtrusive and have lengthy life-spans. The largest disadvantage of passive systems is that the reader must provide a powerful transmission in order to power the tag. This results in large power requirements and limits the signal range. Generally the tag must be within a few feet of the reader to be “seen”.

Active RFID systems are powered by a battery onboard the tag. When the tag detects the reader signal, it transmits a reply. Some active systems have a range of hundreds of feet, but more importantly multiple tags can be identified simultaneously. The tag can also respond independently of the reader, such as activating if an attempt is made to disable it. Both passive and active RFID systems in the current state of the art rely on detecting the presence of a tag near an exit to activate an alarm.

Various proposals for other theft alarm devices are found in the art. U.S. Pat. No. 4,584,571 discloses attaching a permanent magnetic body to a valuable article that is placed in a bag. The bag includes circuitry that sets off an alarm when the magnet is missing unless manually overridden.

U.S. Pat. No. 5,963,131 discloses using a motion sensor in combination with a proximity sensor to guard valuables and reduce incidences of false alarms. A theft detector unit is integrated into a laptop, and a control unit is carried by the user to maintain two-way communication with the laptop.

U.S. Pat. No. 6,172,607 discloses an alarm that is attached to an object and manually activated. When the object is thereafter moved, an alarm sounds until disarmed by entering a security code or the internal power source is exhausted. Thus, the alarm detects its own movement, and no corresponding device is used.

While assumably effective for their intended purposes, none of the above proposals provide an anti-theft alarm system that addresses the needs of decentralized merchants. Therefore, it is desirable to have a security device and alarm system that is unobtrusive, can be used in a variety of settings, is able to monitor and distinguish between multiple objects, alerts the merchant when the device is turned off, and is inexpensive.

SUMMARY OF THE INVENTION

A security device and alarm system according to the present invention includes a reader, at least one security tag, and an alarm unit. The reader includes a reader transmitter, a reader receiver, a CPU, a reader power source, and a power switch. The security tag is remote from the reader and includes a tag transmitter electrically connected to a tag receiver. If active RFID tags are used, each tag also includes a power source. The alarm unit is remote from the reader and the tag and includes an alarm receiver and an alarm electrically connected to an alarm power source.

In use, an inspection loop is established wherein the reader transmitter sends a query signal to the tag, the tag receiver receives the query signal, the tag transmitter sends a reply signal, the reader receiver receives the reply signal, and the reader CPU checks for the appropriate reply signal and for power failure of the reader. If an appropriate reply signal is not received by the reader receiver or if the CPU has been turned off, the reader transmitter sends an alarm signal to the alarm unit. Upon receipt of an alarm signal by the alarm receiver, the alarm is energized. If multiple active RFID tags are used, the reader CPU checks for the presence of each active RFID tag through the use of tag transmission identifiers. Further, unique alarm signals are used to identify the missing active RFID tag, and the alarm includes means to identify each active RFID tag individually. The reader is preferably concealed in a fabric article, though other arrangements are of course possible.

Therefore, a general object of this invention is to provide a security device and alarm system that takes into account the decentralized nature of many businesses.

Another object of this invention is to provide a security device and alarm system, as aforesaid, that is unobtrusive.

Still another object of this invention is to provide a security device and alarm system, as aforesaid, that can be used in a variety of conditions, such as inside, outside, in separate booth arrangements, in large galleries, etc.

Yet another object of this invention is to provide a security device and alarm system, as aforesaid, that is able to monitor and distinguish between multiple objects.

A further object of this invention is to provide a security device and alarm system, as aforesaid, that alerts the merchant when the device is turned off.

A still further object of this invention is to provide a security device and alarm system, as aforesaid, that is inexpensive.

Other objects and advantages of this invention will become apparent from the following description taken in connection with the accompanying drawings, wherein is set forth by way of illustration and example, embodiments of this invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

A security device and alarm system according to the present invention will now be described in detail with reference toFIGS. 1 through 3of the accompanying drawings. More particularly, a security device and alarm system100includes a reader110, a security tag120, and an alarm unit130.

The reader110includes a reader transmitter112, a reader receiver114, a CPU116, a reader power source118, and a power switch119electrically connected as shown inFIG. 2. The reader transmitter112is capable of transmitting query signals150and alarm signals152, and the reader receiver114is capable of receiving reply signals154. The reader transmitter112and the reader receiver114preferably utilize RFID (Radio Frequency Identification) technology, making the reader110a RFID reader110. A wire loop antenna113preferably functions as both the reader transmitter112and the reader receiver114, though other transmitters and receivers may of course be used. It is also understood that other technologies may be suitable besides RFID, such as AM (acousto-magnetic) or swept-RF technology.

The tag120is remote from the reader110and includes a tag transmitter122electrically connected to a tag receiver124(FIG. 2). The tag transmitter122is used to transmit reply signals154, and the tag receiver124is used to receive query signals150. Here, the tag120is a passive RFID tag and does not require a battery power source. Instead, energy from signals received by the tag receiver124is used to power the tag transmitter122. Whenever the tag receiver124receives a query signal150, the energy from the query signal150powers the tag transmitter122, and the tag transmitter122transmits a reply signal154.

The alarm unit130is remote from the reader110and the tag120and includes an alarm132, an alarm receiver134, and an alarm power source138electrically connected as shown inFIG. 2. The alarm receiver134is used for receiving alarm signals152, and the alarm132is used to notify a user of the alarm signal152. Whenever the alarm receiver134receives an alarm signal152, the alarm power source138energizes the alarm132. The alarm132may incorporate various alarming devices, such as a piezoelectric buzzer135, a vibrator136, or a visual alarm137, or the like (FIG. 4). The alarm unit130may be very small, allowing the alarm unit130to be shaped like jewelry (such as the bumblebee broach alarm unit133seen inFIG. 1) or to be placed easily in a pocket. Conversely, the alarm unit130may be larger to incorporate a piezoelectric buzzer135, a vibrator136, and a visual alarm137, as well as other desired alarming devices (FIG. 4). Ideally, the alarm132unobtrusively informs the user that an object has been moved from the range of the security device and alarm system100.

In use, the reader110is preferably positioned in a fabric article for concealing the presence of the reader110, such as a table with a fabric top3(FIG. 1), a tablecloth, or rug. While most large retailers with tightly controlled exits opt to make their security devices clearly visible, it may be beneficial to the decentralized merchant to conceal the presence of the security device and alarm system100. Concealment that a security system exists may in fact reduce the likelihood that someone will attempt to bypass the security device and alarm system100while unattended. The tag120is attached to an item of value that the user wishes to protect by adhesives, clips, or other attachment means. The tag120is shown attached to a vase2inFIG. 1. The user then monitors the alarm unit130. The processing steps of the logic performed by the reader110are shown in the flowchart ofFIG. 3.

In process step S1, the reader power switch119is pressed, turning the reader110on. The process then proceeds to step S2, where the reader transmitter112sends a query signal150to the tag receiver124. The process then proceeds to step S3, where the reader receiver114attempts to receive a reply signal154from the tag transmitter122. The process then proceeds to step S4.

In process step S4, the reader CPU116determines whether the reader receiver114received a reply signal154from the tag transmitter122. If so, the process is directed to step S6. If not, the process is directed to step S5.

In process step S5, the reader transmitter112sends an alarm signal152to the alarm receiver134, and the process proceeds to step S6. It should be appreciated that the reader110is using an object's absence to notify a user of possible theft, unlike traditional anti-theft devices used by large retailers that use an object's presence near an exit to notify of possible theft.

In process step S6, the reader CPU116determines whether the reader power switch119has been pressed to turn the reader110off. If not, the process proceeds to step S2, forming an inspection loop. If so, the process is directed to step S7.

In process step S7, the reader transmitter112sends an alarm signal152to the alarm receiver134, and the process proceeds to step S8.

In process step S8, the reader110deactivates (turns off). It is obvious, then, that the reader110cannot be deactivated without the user being warned.

A security device and alarm system200according to another embodiment of the present invention is shown inFIGS. 4 through 6and includes a construction substantially similar to the construction previously described except as specifically noted below. More particularly, the security device and alarm system200according to this embodiment is an active RFID system.

Each tag120of a plurality of tags120is an active RFID tag that includes a tag transmitter122, a tag receiver124, and a power source228(FIG. 5). Each tag transmitter122has a predetermined tag transmission identifier254different from a predetermined tag transmission identifier254of any other tag transmitter122(FIG. 5). Whenever the tag receiver124receives a query signal150, the power source228powers the tag transmitter122, and the tag transmitter122transmits a reply signal154that includes a corresponding tag transmission identifier254. The tag transmission identifier254is preferably a unique modulation or frequency, though other identifiers are of course possible.

The reader transmitter112and the reader receiver114utilize active RFID technology, making the reader110an active RFID reader110(FIG. 5). The reader CPU116has means for recognizing each tag transmission identifier254and associating each tag transmission identifier254with a corresponding active RFID tag120. The reader CPU116also has means for determining whether an appropriate reply signal154is received by the reader receiver114after the reader transmitter112transmits a corresponding query signal150. The reader transmitter112includes means for transmitting a plurality of unique alarm signals252, and each unique alarm signal252is associated with a respective active RFID tag120. Transmission of the unique alarm signals252by the reader transmitter112is actuated by the reader CPU116if the appropriate reply signals154are not received by the reader receiver114after the reader transmitter112transmits a corresponding query signal150.

The alarm unit130includes means for indicating which active RFID tag120is associated with each unique alarm signal252and, when the alarm receiver134receives a unique alarm signal252, the alarm132indicates the associated active RFID tag120. This may be done through a plurality of visual alarms137, different behaviors of the piezoelectric buzzer135or the vibrator136, or a combination of the various alarming devices.

The processing steps of the logic performed by the reader110are shown in the flowchart ofFIG. 6. In process step S201, the reader power switch119is pressed, turning the reader110on. The process then proceeds to step S202, where the reader transmitter112sends a query signal150to the tag receivers124. The process then proceeds to step S203, where the reader receiver114receives all reply signals154and the reader CPU116records the corresponding tag transmission identifiers254. The process then proceeds to step S204.

In process step S204, the reader transmitter112sends a query signal150to the tag receivers124. The process then proceeds to step S205, where the reader receiver114receives all reply signals154. The process then proceeds to step S206.

In process step S206, the reader CPU compares each tag transmission identifier254received in step S205to the tag transmission identifiers254recorded in step S203and determines if any replies are missing. If so, the process is directed to step S207. If not, the process is directed to step S208.

In process step S207, the reader transmitter112sends a unique alarm signal252corresponding to the missing active RFID tag120to the alarm receiver134, and the process proceeds to step S208.

In process step S208, the reader CPU116determines whether the reader power switch119has been pressed to turn the reader110off. If not, the process proceeds to step S204, forming an inspection loop. If so, the process is directed to step S209.

In process step S209, the reader transmitter112sends a unique alarm signal252corresponding to the power failure to the alarm receiver134, and the process proceeds to step S210.

In process step S210, the reader110deactivates (turns off). It is obvious, then, that the reader110cannot be deactivated without the user being warned and that the user receives notice of which RFID tag120is missing, if any.

A security device and alarm system300according to still another embodiment of the present invention is shown inFIGS. 7 through 8band includes a construction substantially similar to the construction previously described except as specifically noted below. More particularly, the reader110of the security device and alarm system300according to this embodiment is positioned in an ornamental case4for concealing the presence of the reader110.FIG. 8bis shown without the case lining5to better demonstrate the security device and alarm system300.