AU2003235081A1 - Surface acoustic wave device - Google Patents

Description

19108/9003 16:34 11/8/0031134Chryi I llu Law 99534744 7/lb

I

A SCANI'4N0 IDENTIFICATION SYSTEM USIN A SURFACE ACOUSTIC WAVE DEVICE Field of Invention s The present invention relates to scanning systems used in retail, inventory control, identification, luggage handling systems and like identification systems, and in particular, to scanning systems using passive surface acoustic wave (SAW) devices or tags. Known devices or transponders of this ind have a substrate of piezoelectric material having coded information inscribed thereon. The ic transponders are adapted to receive electromagnetic energy, convert it to acoustic energy, store the convented energy for a period of time, re-convert the stored energy to electromagnetic form and re-transmit the electromagnetic energy. The tags thus produce a reply signal in response to an interrogation signal from a remote interrogator or scanner. The reply signal is processed to recover the code unique to the interrogator or scan tag.

Backuund. Art Passive label interrogation systems employing SAW technology are disclosed in Cole and Vaughan US patents 3,706,094, 3,755,803, 4,058,217 and 4,399,441, and in a later device as disclosed in W090/05409.

2a The, devices as disclosed in the specifications of the above US Patents were produced such that each tag or device had a separate mask to produce individually different coded SAW chips. The wo90f05409 patent specification disclosed a mask which was able to be used for a significant number of coded arrangements whereby the number of fingers and arrangement of the fingers can be selected for each code and arrangement.

The prior art SAW devices use a frequency of 925Mhz. With recent improvements in photolithography, it is now possible to increase the fundamental frequency used in the SAW arrangements to, for example, 2.46 0Hz and substantially decrease the dimensions required for the piezoelectric substrate. The decrease in dimensions of 3o the substrate allows the costs of the manufacture of the device or tag to be substantially reduced whereby the use of such tags in identification systems becomes more viable, in that costs are reduced as well as having a identification which is substantially unobtrusive. However, there is trade off between having a \~sereAekdomNsatIsXwrnp1 1310O.doc COMS ID No: SMBI-03B2832 Received by IP Australia: Time (I-tm) 18:39 Date 2003-08-19 19/08/2003 16:34 19/8/0031834Chrvl lois Lmw 99534744 8/19 2 very small saw device and having a SAW device having a very high number of unique codes Associates therewith. This is particularly the case when using the interdigitated SAW device as disclosed in the W090/05409 specification as described above.

Object of the Invention it is an object of the present invention to provide a scanning identification system using a surface acoustic wave device such that the manufacture of the devices wili enable reductions in manufacturing, production and implementation costs.

At the very least, the present invention provides an alternative to known scanning lo identification systems.

Summar of the Invention According to one aspect of the present invention there is disclosed a scanning identification system using surface acoustic wave devices, said system including a plurality of surface acoustic wave devices, each said device being attached to one entity to be identified, said devices being coded to represent that particular entity, an interrogation signal transmitting means adapted-to transmit continuous signals to said devices attached to said plurality of entities, said devices being adapted to receive said continuous signals when within a predetermined distance or range of said transmitting means, and after receipt of said continuous signals, the surface acoustic wave receiving the signal produces a reply signal according to its code and transmits said reply signal to an interrogator signal receiving means, the interrogation signal receiving means being adapted to accept the strongest reply signal being received from said devices, a reply signal deactivation means adapted to deactivate said signal received once it is received to enable said receiver to receive other said reply signals, and processing means adapted to process data received in said reply signals, wherein the continuous signals have both amplitude and phase modulation to increase the number of codes able to be interrogated.

Preferably, the amplitude and phase modulation increases the code pit capacity of the system of forty eight thousand BPS4600VAUDh 3o It is seen that the sunmming an average in overtime of multiple identical interrogations per second in reading the SAW device provides for synchronised noise cancellation.

V~evrDdsp~nscmk 131Si.doc COMS ID No: 5M81-00382832 Received by IP Australia: Time 16:39 Date 2003-08-19 19/08/2003 16:35 13/S/OOS9536Chryal IaLou Law 99534744 9/19 3 Brief Description of the Drawings To facilitate understanding of the invention in its various forms, practical embodiments will now be described by way of example only, with reference to the accompanying drawings in which: Figure 1 is schematic diagram showing the arrangement of a preferred embodiment of the present invention.

Description of Preferred Embodiments A scanning identification system 10 is used to identify' entities or items 11I by using passive surface acoustic wave devices (SAW) 12 attached to each item 11. The SAW devices 12 are similar to those disclosed in W090/05409 by Cosnio Holdings Pty Limited, however the fundamental frquency of the SAW is increased to 2A46Gz which substantially reduces the dimension of the piezoelectric substrate layer which enables the SAW device 12 to be inexpensive.

The system 10 includes an interrogation signal module 13 which includes a transmitter 14 and a receiver 15 whereby a continuous interrogation signal 16 is transmitted fi-rm the transmitter 14. The preferred range of the transm-itted signal is about six metres. All of the items I11 within this range of the continuous signal receive the interrogation signal 16 and produces its own coded surface acoustic wave which is then retransmitted as a reply signal 17 back to the module 13. The module 13 includes processing and control apparatus 18 adapted to be connected to a memory storage device 19. The memory storage device 19 can be included in the module 13.

The receiver 15 receives the strongest reply signal 17 and the processing and control apparatus 18 deactivates the item 11 having the uniquely coded signal thus preventing collision and scan deactivation problems associated with prior art systems.

The scanning identification system 10 of the preferred embodiment is useful in retail, toliways, livestock and other identification systems.

With regard to retail security, at present security does not have uniquely coded tags 3o and can only be read by transceivers to a distance of about 500 millimetres. The embodiment of the present invention can uniquely identify four billion separate tags and can be read from distances up to 6 metres.

\%*erreWocs~peIenbnomwpkI1 G .doc COMS ID No: SMBI-0a352832 Received by IP Australia: lime (HWm) 16:39 Date 2003-08-19 19/08/2003 10:35 19/3/0031835ChrysimIlou Law 18534744 10/19 4 The unique identification of articles or items means that the system is able to be used for inventory control as well as simultaneously acting as a security device.

The system can therefore take the place of presently used barcode systems. For example, as each item is individual and each item is "legitimately sold", the system can be used for tracking and re-ordering of stock. In such use of the system, the item data is not deleted from the database but is just marked as "read".

As the items are scanned, the data on the database about that particular item is processed according to the actual transaction occurring. For example, if the item is being marked as sold on the database and the security arrangements can be such that the item can be removed from the premises without a security scanner alarm being activated. In other arrangements, the scanning device can be used to check the items which are presently in stock as it can scan all items which have the tags attached thereto.

With regard to the use of the scanning identification system being used for toliways, the devices or tags are passive devices and therefore require no power of their own. As the motor vehicle having the device passes through the tollway, the processing and control apparatus is used to identify the vehicle and charge the user of the vehicle accordingly.

In livestock industries, cattle tagging is now compulsory in Europe, USA and most other countries. The tag or device of the embodiments of the present invention can be fixed as an ear tag or implanted into the animal's tissue minimising damage to the tag. The aerial of the device is left exposed.

Electronic tagging is becoming important due to the speed to which records can be gathered and despatched.

The fact that the devices or tags of the present invention can be read up to 6 metres compared to 3 00 millimetres of existing tags, this is important when trying to identify cattle in a paddock where closeness to cattle may be difficult and dangerous.

The devices can also be used to tag other livestock such as sheep.

a The scanning identification system of the present invention can also be used in the following applications: Mserverkc'locsiptentacompN1 13 Sl~dcc COMS ID No: SMSI-00382832 Received by IP Australia: lime 18:39 Date 2003-08-19 13/08/2003 16:3 Chr rslllou Liw 99534744 11/19 Vehicle parking and area access control Vehicle identification systems Container identification Luggage handling systems Forestry inventory control Passport applications Packaging and parcel systems Inventory control and sales packaging Personnel I.D. and area access control Patent I.D. in hospitals as well as temperature monitoring The foregoing only some embodiments of the present invention, and modifications of these to those skilled in the art can be made thereto without departing from the scope of the present invention.

%\server~docspatents\comp\11310.doc COMS ID No: SMBI-00382832 Received by IP Australia: Time 16:39 Date 2003-08-19

Claims (8)

1. A scanning identification system -using surface acoustic wave devices, said system including a plurality of surface acoustic wave devices, each said device being attached to one entity to be identified, said devices being coded to S represent that particular entity, an interrogation signal transmitting means adapted to transmit continuous signals to said devices attacbed to said plurality of entities, said devices being adapted to receive said continuous signals when within a predetermined distance or range of said transmitting means, and after receipt of said continuous signals, the surface acoustic wave receiving the signal produces a reply signal according to its code and transmits said reply signal to an interrogator signal receiving means, the interrogation signal receiving means being adapted to accept the strongest reply signal being received from said devices, a reply signal deactivation means adapted to deactivate said signal received once it is received to enable said receiver to receive other said reply signals, and processing means adapted to process data received in said reply signals, wherein the continuous signals have both amplitude and phase modulation to increase the number of codes able to be interrogated.

2. The scanning identification system according to claim 1, wherein the amplitude and phase modulation increases the code pit capacity of the system of forty eight thousand BPS4600VAUD.

3. The scanning identification system according to claim 2, wherein the summing an average in overtime of multiple identical interrogations per second in reading the SAW device provides for synobronised noise cancellation.

4. The scanning identification systemn according to claim 3, wherein fundamnental frequency of the surface acoustic wave is 2.46Gz which substantially reduces the dimension of the piezoelectric substrate layer.

The scanning identification system according to claim 4, wherein the system includes an interrogation signal module which includes a transmitter and a receiver whereby the continuous interrogation signal is transmitted from the transmitter.

6. The scanning identification system according to claim 5, wherein the range of the transmitter is less than about six metres, whereby all items within this range receive the interrogation signal and produces its own coded surface acoustic wave which is then retransmitted as a reply signal back to the module. A~servewe~capatentscomp\1 310Odoc COMS ID No: SMBI-00382832 Received by IF' Australia: Time 18:39 Date 2003-08-19 19/08/2003 10:36 Chryalllou Law 99534744 13/19 7

7. The scanning identification system according to claim 6, wherein the module includes processing and control apparatus adapted to be connected to a memory storage device.

8. The scanning identification system according to claim 7, wherein the memory storage device is included in the module. Dated this 19th day of August 2003 Vaughan Technologies Pty Ltd Patent Attorneys for the Applicant to CHRYSILIOU LAW \server\eWdoc\patentscomptl 13104doc COMS ID No: SMBI-00382832 Received by IP Australia: Time 16:39 Date 2003-08-19