|Publication number||US3711848 A|
|Publication date||16 Jan 1973|
|Filing date||10 Feb 1971|
|Priority date||10 Feb 1971|
|Publication number||US 3711848 A, US 3711848A, US-A-3711848, US3711848 A, US3711848A|
|Original Assignee||I D Eng Inc|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (3), Referenced by (70), Classifications (12)|
|External Links: USPTO, USPTO Assignment, Espacenet|
United States Patent n91 Martens METHOD OF AND APPARATUS FOR THE DETECTION OF STOLEN ARTICLES  Inventor: Henry J. Martens, Lynnfield, Mass.
 Assignee: I. D. Engineering, Inc., Lynn, Mass.
221 Filed: Feb. 10,1971
211 Appl. No.: 114,306
 US. CL... ..340/280, 340/258 C, 325/8 [5 l Int. Cl. ..G08b 21/00  Field of Search ..340/280, 258; 325/8  References Cited UNITED STATES PATENTS 3,534.358 l0/l970 Stern ..340/280 3.518.546 6/l970 Augenblick et al. ..325/8 3,493,955 2/[970 Minasy ..340/280 Primary Examiner-John W. Caldwell Assistant Examiner-Michael Slobasky Att0rneyOberlin, Maky, Donnelly & Renner [4 1 Jan. 16, 1973  ABSTRACT A system for detecting the unauthorized removal of protected articles from a designated area comprising a harmonic generator circuit made up of a semiconductor diode chip and a pair of antennas adapted to receive a radio frequency signal at a first frequency and transmit a second radio frequency signal at a second, relatively higher frequency. Transmitting and receiving means are positioned adjacent an exit area for actuating the circuit and an alarm when protected articles approach the area, and means are provided for deactivating the circuit when the protected article is legitimately purchased.
The generator circuit can be manufactured at very low cost thereby permitting, when a legitimate sale is made, permanent deactivation of the circuit without removing or otherwise handling the tag or label carrying the circuit.
4 Claims, 21 Drawing Figures PATENTEDJAN 16 1915 I 3.711.848
SHEET 3 UF 3 l! I I I I I I I 1 l I I I J I I I I I I I I I I [A l I Fig.17 l6 l6 METHOD OF AND APPARATUS FOR THE DETECTION OF STOLEN ARTICLES BACKGROUND OF THE INVENTION The present invention relates generally to theft detection apparatus and more particularly to a method of and apparatus for detecting the passage of articles past predetermined check points and signaling such passage so that the person or persons surreptitiously removing such articles from the premises can be apprehended.
Shoplifting has long posed a considerable problem to retail business establishments, with the magnitude of such problem growing yearly. Numerous methods have been tried in order to reduce the loss caused by shoplifting, including various systems of personnel surveillance and, more recently, by means of electrical and mechanical theft detection devices or systems. The use of personnel to detect and apprehend shoplifters has obvious shortcomings. The use of floor walkers, security guards and the like constitutes a considerable business expense, oftentimes exceeding the amount saved as a result of reduced pilferage. In addition, the presence of security personnel is often at the sacrifice of the good will of the business for whom such personnel are hired, with the loss of good will being considerably magnified where customers thought to be shoplifters are mistakenly apprehended.
The provision of an electrical or mechanical theft detection system does of course obviate the above noted problem with respect to security personnel, but these systems have in the past not proven entirely satisfactory for a number of reasons. Systems representative of the prior art include U.S. Pat. Nos. 2,774,060; 3,493,955; and 3,500,373. The detection device disclosed in U.S. Pat. No. 2,774,060 for example, requires that the tag or label mounting the detection circuit be removed by the cashier, which adds to the checkout time, a source of possible customer dissatisfaction, as well as permitting I SUMMARY OF THE INVENTION With the above in mind, a primary object of the present invention is to provide a harmonic generator circuit which is simple and reliable and which will function to actuate an alarm circuit or the like when articles have surreptitiously passed a predetermined checkpoint such as the cashiers checkout area.
A further object of the present invention is to provide such a harmonic generator circuit which is both relatively small in size and inexpensive to manufacture. In accordance with the invention, the circuit is embodied in a relatively small tag or label which can be conveniently embedded or concealed within articles desired to be protected. In view of the substantially reduced cost of manufacture of each tag or label, the
same can be left concealed or hidden in such articles when the same are purchased, and simply deactivated at the checkout point to prevent actuation of the alarm which would otherwise occur when the purchaser leaves the store.
A further object of the present invention is to provide a harmonic generator circuit which operates at relatively high frequency thereby precluding inadvertent actuation of the circuit by unprotected metallic articles passing through the checkout area.
A still further object of the present invention is to provide a new method of manufacture of the harmonic generator circuit, in which a continuous strip of Iongitudinally spaced circuits can be formed, assembled and thereafter cut into predetermined lengths.
A further object of the present invention is to provide a generator circuit which is readily adaptable to other areas of surveillance in addition to the environment disclosed. In view of the size, reliability and low manufacturing cost, the invention can be used as well in the surveillance of personnel to detect the passage of unauthorized persons through predesignated areas.
These and other objects will become apparent to those skilled in the art as the following description proceeds, in particular reference to the application drawings, in which:
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view illustrating a doorway having mounted on either side thereof a transmitting and receiving unit for detecting the presence of protected articles which have surreptitiously passed the cashier checkout counter;
FIG. 2 is a perspective view showing a typical checkout counter, having associated therewith means for deactivating protected articles which have been legitimately purchased;
FIG. 3 is a sectional view through a tag or label constructed in accordance with the present invention, taken on line 3-3 of FIG. 4;
FIG. 4 is a plan view of the tag or label of FIG. 3;
FIG. 5 is a diagrammatic view of the transmitter unit used in the present invention;
FIG. 6 is a diagrammatic view of the receiver and alarm circuit used in accordance with the present invention;
FIG. 7 is a diagrammatic view of the deactivation circuit constructed in accordance with the present invention;
FIG. 8a is a plan view of a diode chip constructed in accordance with the present invention;
FIG. 8b is a side elevational view of the diode chip;
FIGS. 9-43 comprise top plan views of various forms of antennas which can be used in combination with the diode chip 28 to form the harmonic generator circuit;
FIG. 14 comprises a longitudinal sectional view taken on line 14-14 of FIG. 15 showing the top half of a tape member or the like carrying a metalized antenna pattern on the bottom side thereof;
FIG. 15 is a bottom plan view of the tape shown in FIG. 14;
FIG. 16 is a longitudinal sectional view taken on line 16-16 of FIG. 17, showing a mating tape member carrying a metalized antenna pattern on the bottom thereof for subsequent association with the member shown in FIG. 14;
FIG. 17 is a bottom plan view of the tape member of FIG. 16;
FIG. 18 is an isolated, reduced view of the diode chip constructed in accordance with the present invention;
FIG. 19 is a longitudinal sectional view taken through the assembled harmonic generator circuit of the invention, and
FIG. 20 is a top plan view of the assembly of FIG. 19.
DETAILED DESCRIPTION OF THE INVENTION Referring now in more detail to the drawings, wherein like parts are indicated by like reference numerals, and initially to FIGS. 1 and 2, there is illustrated therein a typical environment in which the present invention may be used to advantage. These figures are intended to depict a typical checkout and exit arrangement in a department store or the like, with the exit being indicated by door 25 on either side of which is mounted a transmitter and receiver unit 26, the construction of which is shown diagrammatically in FIGS. 5 and 6 and which will be discussed in detail when specific reference is made to these figures.
FIG. 2 illustrates a typical checkout area, comprising checkout counter C and cash register 37. Disposed laterally of the counter at the exit end thereof are deactivating units 38 and 39 between which the protected articles purchased in an authorized manner can be passed for deactivation of the harmonic generator circuit.
Referring now to FIGS. 3 and 4, a tag or label 27 has embedded therein the harmonic generator circuit of the present invention, which comprises a diode chip 28 and metal antennas commonly designated at 29. The diode chip may comprise a conventional point-contact diode but preferably comprises a Schottky diode, the characteristics of which are well known in the art. As will be explained in more detail when specific reference is made to FIGS. 14-20, the anode and cathode of the semi-conductor diode chip 28 are connected respectively to the antennas 29. The circuit can be embedded or encased in the tag or label 27 in a known manner which forms no part of the present invention. It will further be understood that the form of carrier for the circuit will normally depend upon the ultimate desired use of the circuit, with the tag 27 representing a typical use where the circuit can be conveniently concealed in articles to be protected.
The harmonic generator circuit just described is capable of receiving a radio signal at one selected frequency, which will be called F and transmitting a radio signal at twice this frequency, 2F,,. Although the particular frequency employed is not critical, preferably high frequency ranges are employed in order to preclude false actuation of the system by unprotected metallic articles passing through the checkpoints. A typical operating frequency, for exam ple, would be F, at 912 megacycles, so that the generator circuit transmits a radio signal at 2F or 1824 megacycles. It will be understood that these frequencies are exemplary, and that other frequency ranges could also be satisfactorily employed.
Referring to FIG. and 6, each of the transmitter and receiver units 26 comprises a transmitter circuit shown in FIG. 5 and a receiver circuit shown in FIG. 6. The transmitter circuit includes a high frequency generating source 30, a filter 31, and a transmitting antenna 32. Each of these components is commercially available and per se forms no part of the present invention.
The high frequency source 30 delivers a continuous, non-modulated radio frequency signal through the filter 31 to the transmitting antenna 32 which provides radiation of the radio frequency signal at the selected frequency F in the direction of the doorway 25. The filter 31 functions in the usual manner to assure passage of signals of such predetermined frequency and to suppress higher harmonics of such frequency.
Referring to FIG. 6, the receiving circuit comprises a directional receiving antenna 33, a band pass filter 34, a receiver 35, and alarm means 36, which can comprise a flashing light, bell, or other audible or visual alarm. In a manner well-known in the art, the band pass filter 34 will only pass radio signals within predetermined frequency limits, with the limits being selected in the present instance to include the frequency 2F, I824 megacycles. Satisfactory limits for the band pass filter can be, for example, between 1775 and 1875 megacycles, and it will be understood that the receiver 35 is sharply tuned only to signals in this range. The receiving of signals in this range by the receiver 35 actuates the alarm 36 thereby indicating passage through the doorway 25 of articles that are protected and that have not been processed through the checkout counter as authorized. All of the components 33-36 are similarly conventional and commercially available.
Referring to FIG. 7, there is illustrated therein the power circuit for deactivating the harmonic generator circuit as protected articles are processed through the checkout counter after legitimate sale. The power circuit includes antennas 38 and 39 and generating means 40 coupled therewith for providing a power signal. The frequency of the power signal is selected to be approximately F and the power output is approximately 10 watts, substantially higher than the power output of the high frequency source 30, which is preferably at or less than 1 watt.
When a protected article is processed subsequent to a legitimate sale, the sales clerk passes the protected article or package through the electromagnetic field between the antennas 38 and 39. The relatively high output of the power source 40 functions to burn out and thus permanently deactivate the tag or label 27 associated with the article whereby the article may freely pass through the doorway 25 without actuation of the units 26 as the merchandise leaves the store. The electromagnetic energy radiated by the antenna 38 will be absorbed by the antenna 39 thereby preventing radiation outside the system.
Referring to FIGS. 8a and 8b, the semiconductor diode chip 28 includes an anode 42 formed on the top of the diode chip and a cathode 43 which forms the bottom of the diode chip.
FIGS. 9-13 illustrate various shaped antennas 41 which extend to either side of the diode chip 28 and are electrically connected respectively to the cathode 43 and anode 42. In these figures, the circuit is shown em bedded in the tag 27. The diode chip 28 is preferably of a preselected polarity, and the shape or design of the particular antenna 41 employed is based on which antenna design will perform the best in view of the polarity of the electromagnetic field radiated by the transmitter antenna 32.
There is illustrated in FIGS. 14-20 the preferred method of manufacturing the harmonic generator circuit in accordance with the present invention. Referring to FIGS. 14 and 15, a tape member 44 has a thin metalized antenna pattern 45 formed thereon which comprises one-half of the antenna assembly. It will be noted that the antenna pattern 45 is pointed at one end as shown at 48. The tape 44 can be constructed of any suitable material, with the underside of the tape containing the metalized antenna section being preferably coated with glue, and the exterior surface of the tape being preferably coated with vinyl or similar plastic material.
FIGS. 16 and 17 are generally similar to FIGS. 14 and 15, with the underside of the tape member 46 being formed with a similar metalized section 47 having a pointed end portion 49, the direction of which is opposite to the direction of the pointed end 48 of the metalized section 45 of the tape 44. The tape 46 is also preferably provided with glue on the underside thereof carrying the metalized antenna section and vinyl on the opposite, exposed side.
Referring to FIGS. 19 and 20, the tape members 44 and 46 are shown superimposed, with the faces thereof carrying the antenna sections being in contact. As will be seen from the centerline passing from top to bottom through these several figures, the pointed end regions 48 and 49 of the antenna sections overlap and are designed to extend respectively over and under the diode chip 28 which is positioned therebetween in the manufacturing process. The electrical contact between the cathode and anode of the diode chip 28 and the antenna sections 48 and 49 is preferably by pressure, effected during the assemblying of the circuit. During such assembly, the glued material on the contacting sides of the tapes 44 and 46 can be activated so as to firmly bond the tape members together as shown in cross section in FIG.. 19. The assembly thus constitutes a completely embedded diode chip and electrically connected antenna sections, with the exposed surfaces .of the tape being vinyl coated and thus highly resistant to the typical environments to which the circuit is subjected.
As above indicated, the size of the harmonic generator circuit assembly can be varied and is to a large degree controlled by the length of the antenna portions. In the assembly illustrated in FIGS. 19 and 20, the length of the assembly is approximately two inches, the width is approximately one-half inch, and the thickness is approximately twentythousandth of one inch. It will thus be seen that the assembly can be concealed without difficulty in clothing, for example. Where higher frequencies are employed, the length of the assembly can be made even shorter, thereby further enhancing concealment of the assembly.
The manner in which the harmonic generator circuit of the present invention functions should be apparent from the above description. To briefly summarize, protected articles, that is articles on or in which the assembly is carried, are normally processed through the checkout counter C, and articles that are so protected are passed between the antennas 38 and 39 after legitimate purchase. The power signal produced by the power source 40 functions to permanently deactivate the assembly thereby permitting passage of the protected article through the doorway 25 when the customer leaves the store.
When a customer attempts to leave the premises through door 25 with a protected article that has not been paid for and deactivated, the article enters the radiation pattern of the transmitter antenna in the units 26. The harmonic generator circuit in the tag or label 27 will transmit a signal at approximately 1824 megacycles. The radio signal at such higher frequency will be received by the receiver 35 which in turn will actuate the alarm 36, thereby alerting store personnel of the theft.
It will thus be seen that the objects of the present invention have been accomplished. There has been provided a harmonic generator circuit which is extremely simple in construction and highly reliable in use. The construction of the device itself, coupled with the unique method of manufacturing the same, permits manufacture at very low cost thereby allowing deactivation of the device at the checkout counter, concealment of the device without removal of the same at the checkout counter, a decided disadvantage with prior art assemblies of this general type. In lieu of removal, the device can simply be activated in the disclosed manner and the assembly left in its concealed position. The operating frequencies are such that inadvertent actuation by metallic articles is virtually precluded.
1. A system for detecting the unauthorized removal of protected articles from a predetennined area comprising a. a semiconductor diode chip having a cathode and an anode,
b. first and second antenna means respectively electrically connected to said cathode and said anode of said diode chip, said antennas being shaped and dimensioned to receive radio frequency signals at first predetermined frequency level and to retransmit said signals at a second predetermined, relatively higher radio frequency level,
c. carrier means for carrying and embedding said diode chip and said antennas for convenient concealment in or association with the article to be protected,
. at least one receiving and transmitting unit positioned near the exit from said area, said unit transmitting radio frequency signals at said first frequency level and receiving radio frequency signals at said second radio frequency level,
. alarm means electrically connected to and actuated by said receiving and transmitting unit when a protected article is in the detectable area around said unit, and
f. deactivating means for permanently deactivating the harmonic generator circuit when said protected article has been legitimately purchased and without requiring disassociation of such circuit from said article, said deactivating means comprising a power signal source for transmitting radio frequency signals at a predetermined power level, and antenna means, the power level of said power signal means being substantially higher than the power level of said signal emitted by said receiving and transmitting unit thereby permanently deactivating said harmonic generator circuit.
2. The system of claim 1 wherein said second radio frequency level is approximately twice the frequency of said first frequency level, and the output power of said said transmitter, and alarm means actuated by said receiver in response to the penetration of a protected article which has not been deactivated into the area of said transmitter.
4. The system of claim 1 wherein said first and second antennas each include a relatively pointed leading end portion adapted to contact and be electrically connected to the cathode and anode, respectively, of said diode chip.
|Cited Patent||Filing date||Publication date||Applicant||Title|
|US3493955 *||17 Apr 1968||3 Feb 1970||Monere Corp||Method and apparatus for detecting the unauthorized movement of articles|
|US3518546 *||12 Dec 1966||30 Jun 1970||Microlab Fxr||Harmonic communication and navigation system|
|US3534358 *||20 Oct 1966||13 Oct 1970||Logistics Ind Corp||Apparatus for detecting objects|
|Citing Patent||Filing date||Publication date||Applicant||Title|
|US3859652 *||26 Jun 1972||7 Jan 1975||North American Systems Corp||Method and apparatus for detecting the theft of articles|
|US3868669 *||13 Apr 1973||25 Feb 1975||Knogo Corp||Reduction of false alarms in electronic theft detection systems|
|US3895368 *||9 Aug 1972||15 Jul 1975||Sensormatic Electronics Corp||Surveillance system and method utilizing both electrostatic and electromagnetic fields|
|US3911534 *||30 Oct 1974||14 Oct 1975||I D Engineering Inc||Anti-theft fastening device|
|US3919704 *||4 Dec 1972||11 Nov 1975||Check Mate Systems Inc||System and method for detecting unauthorized removal of goods from protected premises, and magnet detecting apparatus suitable for use therein|
|US3947930 *||14 Apr 1975||6 Apr 1976||I. D. Engineering, Inc.||Anti-theft fastening device and tool for releasing same|
|US4055796 *||8 Nov 1976||25 Oct 1977||Richard Allen Nelson||Cable support and locator structure|
|US4063229 *||28 Jun 1971||13 Dec 1977||Sensormatic Electronics Corporation||Article surveillance|
|US4158434 *||22 Oct 1976||19 Jun 1979||Glen Peterson||Electronic status determining system for goods|
|US4242671 *||8 Dec 1978||30 Dec 1980||Plows Graham S||Transponders|
|US4260881 *||4 May 1979||7 Apr 1981||Glen Peterson||Electronic status determining label|
|US4574274 *||9 Aug 1982||4 Mar 1986||Sensormatic Electronics Corporation||Non-contact electrostatic deactivator|
|US4783646 *||4 Mar 1987||8 Nov 1988||Kabushiki Kaisha Toshiba||Stolen article detection tag sheet, and method for manufacturing the same|
|US4798175 *||9 Oct 1986||17 Jan 1989||Alfa-Laval Agri, Inc.||Electronic identification system|
|US5043739 *||30 Jan 1990||27 Aug 1991||The United States Of America As Represented By The United States Department Of Energy||High frequency rectenna|
|US5059950 *||4 Sep 1990||22 Oct 1991||Monarch Marking Systems, Inc.||Deactivatable electronic article surveillance tags, tag webs and method of making tag webs|
|US5241923 *||23 Jul 1992||7 Sep 1993||Pole/Zero Corporation||Transponder control of animal whereabouts|
|US5428346 *||28 May 1993||27 Jun 1995||Sealed Air Corporation||Theft alarm activating absorbent pad|
|US5447779 *||27 Jan 1993||5 Sep 1995||Tokai Electronics Co., Ltd.||Resonant tag and method of manufacturing the same|
|US5508684 *||2 Mar 1995||16 Apr 1996||Becker; Richard S.||Article tag|
|US5589251 *||22 Aug 1995||31 Dec 1996||Tokai Electronics Co., Ltd.||Resonant tag and method of manufacturing the same|
|US5682814 *||22 Aug 1995||4 Nov 1997||Tokai Electronics Co., Ltd.||Apparatus for manufacturing resonant tag|
|US5695860 *||1 Sep 1995||9 Dec 1997||Tokai Electronics Co., Ltd.||Resonant tag and method of manufacturing the same|
|US5721783 *||7 Jun 1995||24 Feb 1998||Anderson; James C.||Hearing aid with wireless remote processor|
|US5914692 *||14 Jan 1997||22 Jun 1999||Checkpoint Systems, Inc.||Multiple loop antenna with crossover element having a pair of spaced, parallel conductors for electrically connecting the multiple loops|
|US5990791 *||22 Oct 1997||23 Nov 1999||William B. Spargur||Anti-theft detection system|
|US6038060 *||11 Dec 1997||14 Mar 2000||Crowley; Robert Joseph||Optical antenna array for harmonic generation, mixing and signal amplification|
|US6064308 *||23 Oct 1997||16 May 2000||Pole/Zero Corporation||RF signaling system and system for controlling the whereabouts of animals using same|
|US6166643 *||30 Sep 1999||26 Dec 2000||Janning; Joseph J.||Method and apparatus for controlling the whereabouts of an animal|
|US6254953||2 Dec 1999||3 Jul 2001||World Color Printing Division, Inc.||Antitheft hang tag folded and secured to conceal antitheft marker|
|US6446049||29 Sep 1998||3 Sep 2002||Pole/Zero Corporation||Method and apparatus for transmitting a digital information signal and vending system incorporating same|
|US6700550||9 Jul 2001||2 Mar 2004||Ambit Corporation||Optical antenna array for harmonic generation, mixing and signal amplification|
|US7034687||29 Apr 2004||25 Apr 2006||Comm-Engines||Error-avoiding anti-theft surveillance system|
|US7583192||11 Dec 2006||1 Sep 2009||Keystone Technology Solutions, Llc||Radio frequency identification device and method|
|US7589880||24 Aug 2006||15 Sep 2009||The Trustees Of Boston College||Apparatus and methods for manipulating light using nanoscale cometal structures|
|US7623746||24 Aug 2006||24 Nov 2009||The Trustees Of Boston College||Nanoscale optical microscope|
|US7634162||24 Aug 2006||15 Dec 2009||The Trustees Of Boston College||Apparatus and methods for nanolithography using nanoscale optics|
|US7649665||24 Aug 2006||19 Jan 2010||The Trustees Of Boston College||Apparatus and methods for optical switching using nanoscale optics|
|US7746230||30 Aug 2007||29 Jun 2010||Round Rock Research, Llc||Radio frequency identification device and method|
|US7754964||10 Apr 2006||13 Jul 2010||The Trustees Of Boston College||Apparatus and methods for solar energy conversion using nanocoax structures|
|US7839285||29 Aug 2007||23 Nov 2010||Round Rock Resarch, LLC||Electronic communication devices, methods of forming electrical communication devices, and communications methods|
|US7943847||24 Aug 2006||17 May 2011||The Trustees Of Boston College||Apparatus and methods for solar energy conversion using nanoscale cometal structures|
|US7948382||11 Sep 2006||24 May 2011||Round Rock Research, Llc||Electronic communication devices, methods of forming electrical communication devices, and communications methods|
|US8018340||24 Oct 2006||13 Sep 2011||Round Rock Research, Llc||System and method to track articles at a point of origin and at a point of destination using RFID|
|US8319636 *||21 Jul 2011||27 Nov 2012||Bae Systems Information And Electronic Systems Integration Inc.||Method for locating items|
|US8431816||22 Apr 2011||30 Apr 2013||The Trustees Of Boston College||Apparatus and methods for solar energy conversion using nanoscale cometal structures|
|US20050242954 *||29 Apr 2004||3 Nov 2005||Franklin Todd B||Error-avoiding anti-theft surveillance system|
|US20050242964 *||5 Jul 2005||3 Nov 2005||Tuttle John R||Miniature radio frequency transceiver|
|US20070007345 *||11 Sep 2006||11 Jan 2007||Tuttle Mark E||Electronic communication devices, methods of forming electrical communication devices, and communications methods|
|US20070047056 *||10 Apr 2006||1 Mar 2007||The Trustees Of Boston College||Apparatus and methods for solar energy conversion using nanocoax structures|
|US20070081242 *||24 Aug 2006||12 Apr 2007||The Trustees Of Boston College||Apparatus and methods for optical switching using nanoscale optics|
|US20070103316 *||11 Dec 2006||10 May 2007||Tuttle John R||Radio frequency identification device and method|
|US20070105240 *||24 Aug 2006||10 May 2007||The Trustees Of Boston College||Apparatus and methods for nanolithography using nanoscale optics|
|US20070107103 *||24 Aug 2006||10 May 2007||The Trustees Of Boston College||Apparatus and methods for manipulating light using nanoscale cometal structures|
|US20070137697 *||24 Aug 2006||21 Jun 2007||The Trustees Of Boston College||Apparatus and methods for solar energy conversion using nanoscale cometal structures|
|US20070138376 *||24 Aug 2006||21 Jun 2007||The Trustees Of Boston College||Nanoscale optical microscope|
|US20070240757 *||14 Oct 2005||18 Oct 2007||The Trustees Of Boston College||Solar cells using arrays of optical rectennas|
|US20070290862 *||29 Aug 2007||20 Dec 2007||Tuttle Mark E||Electronic Communication Devices, Methods Of Forming Electrical Communication Devices, And Communications Methods|
|US20070290863 *||30 Aug 2007||20 Dec 2007||Tuttle John R||Radio Frequency Identification Device And Method|
|US20080178924 *||29 Jan 2008||31 Jul 2008||Solasta, Inc.||Photovoltaic cell and method of making thereof|
|US20080202581 *||11 Feb 2008||28 Aug 2008||Solasta, Inc.||Photovoltaic cell with reduced hot-carrier cooling|
|US20080250665 *||22 Jan 2008||16 Oct 2008||Mitutoyo Corporation||Digital displacement measuring instrument|
|US20090007956 *||2 Jul 2008||8 Jan 2009||Solasta, Inc.||Distributed coax photovoltaic device|
|US20110279238 *||21 Jul 2011||17 Nov 2011||Bae Systems Information And Electronic Systems Integration Inc.||Method for locating items|
|USRE44408||8 Dec 2010||6 Aug 2013||Binforma Group Limited Liability Company||RFID system and method for tracking environmental data|
|USRE45766 *||9 Dec 2010||20 Oct 2015||Binforma Group Limited Liability Company||RFID system and method for tracking environmental data|
|EP0002595A1 *||8 Dec 1978||27 Jun 1979||Lintech Instruments Limited||Transponders|
|EP0066403A1 *||17 May 1982||8 Dec 1982||Automated Security (Holdings) PLC||Batteryless, portable, frequency divider|
|EP0548851A1 *||18 Dec 1992||30 Jun 1993||Knogo Corporation||Stabilized article surveillance responder|
|WO1999020497A1 *||22 Oct 1998||29 Apr 1999||Spargur William B||Anti-theft detecting system|
|U.S. Classification||340/572.2, 340/572.3, 343/720, 343/701, 340/572.7|
|Cooperative Classification||G08B13/2422, G08B13/2474, G08B13/2431|
|European Classification||G08B13/24B1M, G08B13/24B7A2, G08B13/24B3C|