WO2011071401A1

WO2011071401A1 - Wireless passive voting device and system

Info

Publication number: WO2011071401A1
Application number: PCT/PT2009/000071
Authority: WO
Inventors: Jorge Manuel Lopes Leal Rodrigues Da Costa; Carlos António CARDOSO FERNANDES; Carla Sofia Dos Reis Medeiros
Original assignee: Instituto De Telecomunicações
Priority date: 2009-12-09
Filing date: 2009-12-10
Publication date: 2011-06-16
Also published as: PT104873B; PT104873A

Abstract

The present invention relates to wireless passive voting device comprising at least a carrier layer made of dielectric material over which is arranged a plurality of RFID tags, each RFID tag corresponding to a selectable vote option or answer; and at least a selected RFID tag masking layer comprising one electromagnetically opaque single film or a plurality of film strips, with said RFID tags of the carrier layer, a region for RFID visibility and RFID tag reading, and which allows detection and unambiguous identification of said RFID tag corresponding to the selected vote option or answer. The present invention further relates to a wireless passive voting system using one or more devices, as well as to a voting method.

Description

DESCRIPTION

WIRELESS PASSIVE VOTING DEVICE AND SYSTEM

FIELD OF THE INVENTION

The present invention relates to a wireless passive voting device and system using radiofrequency identification technology .

BACKGROUND OF THE INVENTION

In television quiz shows, parliaments, classrooms, and other audiences is often necessary to assess simultaneously the opinion of several people. In most cases it is pretended that the user, voter or inquired person select from a limited set of options (at least, one option) preferably without publicly revealing the selected answer or vote. Most part of existing solutions are based on wired devices from which inquired the persons answers are transmitted to an central processing information system. Such devices require installation of a non removable wiring in the voting room. As a result, once installed, they can no longer be used in other rooms.

Recently, RFID technology has been implemented in election environments only for automatic identification of the voter. In WO 2006/093363, entitled "System for Electronically Voting, Counting and Examining Ballots" , a system for electronic voting and counting of ballots, especially for elections, is disclosed. The system includes an identification terminal in which the voter is identified by means of a magnetic card, barcode, or RFID card, related over a net (wireless or cable wired) to a voters database.

Alternatively, wireless communication systems have been proposed, similar to those used in cellular phones. However, such electronic devices are complex and expensive, also being, for that matter, inadequate when used in free access spaces, such as for instance classrooms.

Radiofrequency identification (RFID) technology allows reading and detection of RFID labels (RFID "tags") via radio, without the need of line of sight. Each RFID tag has a unique code associated, and the application on an object unambiguously allows its remote identification.

A standard RFID system includes RFID tags and one or more antennas associated to a radiofrequency reader or interrogator. RFID tags, consisting of a microprocessor and an antenna, may pertain to distinct categories depending on how they work: passive, active and semi-passive tags. Active RFID tags have an energy source in it (typically batteries) and they continuously broadcast the signal to the reader. More usual passive RFID tags do not have any battery, and they draw the energy they need to operate from the signal broadcasted from the reader antenna; when interrogated, the microprocessor contained in the RFID tag broadcasts back to the reader the unambiguous information recorded; they are incomparably less expensive than active tags, but have an inferior range. Semi-passive RFID tags use the battery to power the microprocessor. In all cases, information broadcasted from RFID tags is can be automatically processed by a computer.

In US patent No 2007/0069029, entitled "Method and Systems for Collecting User's Choices using RFIDs" , a method for reading data selected by users using dedicated RFID tags as forms is disclosed. RFID tag circuit is modified by the user when employing a conductive pen to validate a form verification box corresponding to the desired answer. Thus, the user changes the RFID tag internal circuit, and through the connection of the verification boxes to registration circuits in the dedicated RFID tag, the RFID tag answer is modified when interrogated.

RFID technology operates in frequencies regulated by standard specifications and regulatory organizations, typically in LF, HF, UHF and Microwave bands. At present, the most used passive RFID tags pertain to UHF band given its features, low technology cost and a larger range compared to other bands .

In particular, the band assigned by International Telecommunications Union (ITU) to UHF RFID covers the range comprised between 860 and 960 MHz and it was partitioned into three sub-bands for assignment to different world regions.

The present invention, based upon passive UHF RFID, provides a device and an improved reading and counting system of answers in audiences such as classrooms or voting assemblies, and the counting of multiple answers or votes is virtually simultaneous, being advantageous as it does not require any kind of batteries, neither connection leads to the device and is portable. Additionally, the device fabrication method is rather simple and with very low cost, the device being disposable. On the other hand, the device allows an easy and quick evaluation of opinions, knowledge, etc. When voting or carrying out evaluations in a classroom environment or in a knowledge test, it can be provided as a device with anonymous answer or with user identification. SUMMARY OF THE INVENTION

In accordance with an aspect of the present invention, the present invention relates to a wireless passive voting device and system using UHF passive radiofrequency identification (RFID) tags.

Wireless passive voting device in accordance with the invention comprises

at least a carrier layer made of dielectric material with a dielectric permittivity less than 3 and with a thickness less than Ο.ΟΙλο, over which a plurality of RFID tags is arranged radially or azimuthally along a circumference, each RFID tag corresponding to a selectable vote option or answer;

at least a RFID tag masking layer comprising one electromagnetically opaque single film or a plurality of film strips arranged radially or azimuthally along a centre circumference, with a generally rectangular shape, centred or centrable with said RFID tags of the carrier layer, and whose dimensions are larger or at least the same as the dimensions of RFID tags;

a region for RFID visibility and RFID tag reading provided on said RFID tag masking layer, centred or centrable with selected RFID UHF tag and which allows detection and unambiguous identification of said RFID tag corresponding to the selected vote option or answer.

Optionally, the device may present an outer protection layer made of dielectric material, equal or different from the carrier layer.

In a preferred embodiment, the device comprises N RFID tags and electromagnetically opaque single film or N-l electromagnetically opaque strips, wherein N is equal or higher than 2. The visibility region is provided on the RFID tag masking layer as a generally rectangular window. The window is centrable by rotation sliding in the attachment rotating means or by linear sliding of the carrier layer and/or masking layer and/or outer protection layer, with RFID tag corresponding to the selected vote option or answer, allowing reading of the same .

In another embodiment of the device in accordance with the invention, the number of RFID tags and electromagnetically opaque strips, centred in relation to each other, is the same. Alternatively, the masking layer is comprised of a single film. The visibility region is provided on the RFID tag masking layer by detachment of the electromagnetically opaque film or strip centred to the RFID tag corresponding to the selected vote option or answer.

RFID tags on the carrier layer and electromagnetically opaque strips on the masking layer may be arranged along a circumference, the maximum number of tags depending on the circumference radius, size and wavelength in free space.

In another embodiment, wherein RFID tags on the carrier layer and electromagnetically opaque strips on the RFID masking layer are radially arranged, the minimum distance between two adjacent RFID tags and between two adjacent masking strips is higher than 0.04λ_ο, respectively.

In an alternative embodiment of the invention, RFID tags on the carrier layer and the electromagnetically opaque strips on the RFID masking layer are arranged in a parallel and uniformly spaced mode along the carrier layer length. In this case, the minimum distance between two adjacent RFID tags and between two adjacent masking strips is higher than 0.04λ_ο, respectively. Additionally, a second RFID tag masking layer, identical to the masking layer, can be provided over or under RFID tags. The length of electromagnetically opaque strips of both layers is reduced at least to 70% compared to the length of the same, the width being equal or greater than the width of RFID tags.

In any of the above mentioned embodiments, the minimal width and length dimension of the RFID visibility region maintaining the RFID tag range are determined depending on the passive UHF RFID tag width and length and on the wavelength at UHF.

In an alternative embodiment, like a "pocket-knife", the invention comprises

a plurality of RFID tags with a hole provided on one end; a plurality of electromagnetically opaque strips masking RFID tags with a hole provided on one end, arranged alternately to said RFID tags and following the same orientation;

attachment means of said RFID tags and of said masking electromagnetically opaque strips, preferably an axle passing through the tags, electromagnetically opaque strips and barrier layers holes, also appropriate to rotate RFID tag corresponding to the selected vote option or answer and generation of the visibility region, allowing the exhibition, detection and reading of RFID tag.

Optionally, there can be provided two carrier and protection layers, made of metal or dielectric material with an arbitrary permittivity, and also provided with a hole on one end, through which passes said attachment means.

The single film and strips electromagnetically opaque of the masking layer, in accordance with the invention, are comprised of an electromagnetic radiation absorbing or reflective material selected out from a metallic material, absorbing graphite or other electromagnetically opaque material; preferably, the material is an aluminium foil or tin foil.

A wireless RFID voting system for reading and counting of votes or answers, in accordance with the invention, provided with one or multiple devices further comprises, additionally to said devices, a RFID reading antenna connected to a RFID reader, directly or by means of an electronic switch (multiplexer) , such as to allow communication of the data broadcasted by the selected RFID tag(s) in the voting device (s) to a computer application, for registration and/or processing of the reading results, the identification of selected vote option or answer in each device being performed by means of identification codes related to each of RFID tags of the device (s) . Such system can be provided to assign to each voting device the identification of each inquired person and can further comprise the attachment of appropriate deactivation means of the device such as the "kill" command.

The present invention further relates to a voting method such as defined in claim 15.

The device in accordance with the present invention allows advantageous masking, in a simple way, of all UHF passive RFID tags behind an electromagnetically opaque layer except the tag corresponding to the voter selected answer.

Another advantage of the invention lies in the very simple assembly of the device comprising a number of layers with arbitrarily small thicknesses, with different functions, the cost for mass production being so low that the voting devices can be disposable. Still another advantage of the present invention lies in that the device and voting system operate without requiring any kind of wiring or batteries, since it is composed of passive RFID tags. Throughout the following description and claims, the term "comprise" and its variations should not be construed as exclusive of other technical features or components.

Other objectives, advantages and features of the invention will be evident to those skilled in the art after description analysis or can be acquired by implementing the invention.

The following examples and drawings are given by way of example and they are not intended to limit the present invention. Any range or value herein presented can be changed without loss of the intended effects as will be evident to those skilled in the art from the teachings herein disclosed.

Furthermore, the present invention covers all possible combinations of particular and preferred embodiments here disclosed.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is hereinafter described in detail in relation to several embodiments, by way of example, with reference to the figures in which:

Fig. 1 is a partial simplified schematic perspective view of a wireless voting device in accordance with a embodiment of the invention with RFID tags arranged over a circumference on the carrier layer, with the RFID tag masking layer omitted;

Fig. 2 is a partial simplified schematic perspective view of the wireless voting device in fig. 1 with a RFID tag masking layer comprising two electromagnetically opaque strips in a masking position of two of said tags and a RFID visibility region in relation to third tag;

Fig. 3 is a partial simplified schematic perspective view of an alternative embodiment of the wireless voting device in accordance with fig. 1 with a RFID tag masking layer comprising only one electromagnetically opaque strip or film in a masking position of two of said tags and a RFID visibility region in relation to third tag;

Fig. 4 is a partial simplified schematic perspective view of the wireless voting device in accordance with another embodiment of the invention with RFID tags radially arranged on the carrier layer and a RFID tag masking layer comprising two electromagnetically opaque strips in a masking position of two of said tags and a RFID visibility region in relation to third tag;

Fig. 5 is a cross sectional view, along line A-A' in fig. 2 and line B-B ¹ in fig. 4, of a variant in Fig. 2-4 that further comprises a outer protection layer;

Fig. 6 is a cross sectional view, along to line A-A' in fig.

2 and line B-B¹ in fig. 4, of a variant in fig. 2-4 that further comprises a second additional RFID tag masking layer and a outer protection layer;

Fig. 7 is a perspective view of another embodiment of the wireless voting device in accordance with the invention;

Fig. 8 is a perspective view of another embodiment of the wireless voting device in accordance with the invention;

Fig. 9 is a representation of a wireless RFID voting system in accordance with the invention for reading and counting votes with the devices in Fig. 1 to 8. In the figures, the identification of each particular element in discussion is made using a unique numeration.

DETAILED DESCRIPTION OF THE INVENTION AND PREFERED EMBODIMENT

Operation of the device of the present invention is based in the masking and exhibition principle of passive RFID tags with unambiguous identification, associated to different vote options .

The device in accordance with the present inventions, in its more simplified form, comprises a passive UHF RFID tag layer, a visibility region for a RFID tag of the device and a masking layer of the remaining RFID tags. This way, the wireless passive voting device of the present invention comprises at least two passive UHF RFID tags and at least a RFID tag masking layer and a RFID visibility region. Each passive RFID tag corresponds to an answer or vote, whereupon the possible number of vote options in each device depends on the total number of RFID tags contained in the same.

Passive UHF RFID tags essentially comprise a printed antenna and a chip. Mostly, passive RFID tags operating in UHF band are composed of dipole antennas powered by a central chip and are commercially available. In UHF, RFID tags performance can be heavily affected due to the presence of certain materials, such as metal or others whereupon a way to prevent UHF band RFID tags detection consists in blocking the energy incoming to the tag emitted by the reader antenna that would be necessary to the operation thereof. For this purpose, the function of the RFID tag masking layer is to prevent passive UHF RFID tags corresponding to vote options from receiving the necessary energy to be activated, thus making them undetectable by the RFID system (reading antenna and RFID reader) .

The RFID tag masking layer in the present invention comprises at the maximum extent a single film, or at the minimum extent, several strips, electromagnetically opaque, centrable in relation to RFID tags and corresponding chip, for maximizing the device performance. Tags operating in UHF RFID band, linearly polarized, are generally rectangular in shape, as well as the electromagnetically opaque strips, presenting the length as the larger dimension and the width as the lower dimension.

The electromagnetically opaque film or strips can be comprised of an electromagnetic radiation absorbing or reflective material, e. g., a metallic material, absorbing graphite or any material appropriate to produce an electromagnetic shadow. Preferably, they are metallic. Examples of appropriate metallic materials are aluminium foil and/or tin foil.

A device in accordance with the invention comprising N passive UHF RFID tags wherein N is equal or higher than 2, can be provided in the RFID tag masking layer with an electromagnetically opaque single film or with N-l strips centrable over or under N-l RFID tags corresponding to non desired vote options.

In an alternative embodiment, the device comprises a second RFID tag masking layer on the opposed face of passive UHF RFID tags. This embodiment is also appropriate when a stronger device is to be ensured. It requires electromagnetically opaque strips with lesser area than in the case where only one RFID tag masking layer is used. Length of each electromagnetically opaque strip along the RFID tag larger dimension, in case of a single RFID tag masking layer, should not be lesser than the larger dimension Le of the same (usually length) . Width of electromagnetically opaque strips pertaining to the RFID tag masking layer can be any, provided it is at least equal to the RFID tag width. In the limit, the strips can be united, forming a single film.

In devices provided with a double RFID tag masking layer, minimum length of electromagnetically opaque strips on opposed faces to each RFID tag must be at least 70% of the larger dimension of the same (usually length) . As above mentioned, the electromagnetically opaque strips width is not relevant in RFID tag masking layer, provided that it is at least equal to the RFID tags width. In the limit, strips are united, as in the case of a single RFID tag masking layer, forming a single film.

RFID tag detection corresponding to the desired vote in the device of the present invention is provided by a RFID visibility region whose function is to include a RFID visibility area into the device that clears up a volume between RFID reading antenna and the desired passive UHF RFID tag thus allowing the identification of the same by RFID system. For this purpose, overlaying in the device is not allowed, from the point of view of RFID reading system, between electromagnetically opaque material of the RFID tag masking layer and the volume defining RFID visibility region.

RFID visibility region in the device thus corresponds to the minimum area centrable in relation to passive UHF RFID tag which is necessary so that the range of the same is not affected by the RFID tag masking layer material. Thus, RFID visibility region size relies on the size of each RFID tag relatively to wavelength in UHF band. Usually, in UHF, the larger dimension of passive UHF RFID tags, and with linear polarization, corresponds to length Le

(less than half wavelength in UHF) . In this case, RFID visibility region minimum size that does not reduce RFID tag range with reference to the situation in free space for the individual RFID tag in RFID system (reading antenna and RFID reader), width Wj and length Lj are:

Wj = We+0.15X₀ and Lj = Le+0.02X₀ wherein We is passive UHF RFID tag width, Le is the length (larger dimension) of passive UHF RFID tag and λ₀ is UHF wavelength .

The RFID tag layer can be positioned on a carrier layer made of dielectric material for support, with a dielectric permittivity less than 3 and thickness less than 0.01λ₀. Passive UHF RFID tags can be arranged in different ways on the carrier layer: parallel, radially or on an r radius circumference.

The maximum number N of RFID tags on an r radius circumference inside the device should be less than

L_e +0.044, wherein Le is the larger dimension of RFID tag (usually related to length) and λ₀ is wavelength in free space.

When RFID tags are radially arranged, the maximum number N of RFID tags depends on the device largest radius. When they are laid parallel on a plane, the number of tags will depend on the carrier layer length. In both cases, the minimum distance between two RFID tags should be higher than at least 0.04λ₀. In another aspect, voting devices in accordance with the present invention can be disposable or for one use only or reusable .

RFID visibility region corresponding to the vote option can be achieved in a number of ways. In a disposable device, the tags being radially or parallel arranged on a circumference, the visibility region is achieved by simple detachment or removal of the RFID tag masking layer that is deliberately overlapped over the corresponding volume of the RFID visibility region. If a reusable device in accordance with the invention is desired, both RFID tag masking layer (s) and the carrier layer for the RFID tag layer are slidable in rotation or linearly over each other, or like a "pocket-knife", in which case RFID tags are connected by a common attachment and rotating means on one of the ends thereof.

In the "pocket-knife" device of the present invention, RFID tags are arranged parallel to each other and overlapped and are connected by an attachment and rotating means passing through one of the ends of the tags through a hole provided for that purpose. RFID tag masking layer comprises electromagnet ically opaque strips alternating with the RFID tags. Region visibility volume is exhibited after rotating one of the RFID tags, corresponding to the vote, in the attachment and rotating means, thus making it detectable by the RFID reading system. In this embodiment, the device is preferably reusable.

For purposes of support and/or masking of the device operating mechanism, the device can optionally comprise at least an outer protection layer made of dielectric material over the RFID tag masking layer, integral or not with the carrier layer. The carrier layer dielectric material has a dielectric permittivity less than 3 and a thickness less than 0.01λ₀, and the material thereof is the same or different from the carrier layer .

In accordance with the present invention, voting system comprises at least a voting device, at least a RFID reading antenna connected to a RFID reader directly or by means of an electronic switch (multiplexer) so that it allows communication of the data broadcasted by the voting device (s) to a computer application, for registration and/or processing of the reading results. The selected vote identification in each device is performed using a database containing identification codes pertaining to each of the RFID tags of the device (s) .

RFID tag corresponding to the desired answer or vote in the device, when centred to the RFID visibility region, can be interrogated by the UHF RFID reading antenna. Next, RFID tag broadcasts the corresponding identification code that, in turn, is processed by a RFID reader, under the same standard, that returns the identification contained in the tag corresponding to the vote selected by the user. RFID tags remaining covered by RFID tag masking layer are not detected by the RFID system (RFID reading antenna and RFID reader) . Next, reading data is processed using a dedicated and centralized database or in the computer having assigned to each RFID tag of each device the corresponding vote option.

In a voting system in accordance with the present invention, composed of one or multiple devices, only the RFID tag identifications related to selected answers or votes whose volume is uncovered by the RFID visibility regions of devices existing in the region of the detection/covering volume of the RFID reading antenna (s) are detected. One or more RFID reading antennas can interrogate different devices simultaneously. The device and system of the present invention allow an unambiguous identification of the passive UHF RFID tag corresponding to user vote(s), effectively preventing the detection of the remaining RFID tags by the RFID reading system.

Generally, the voting or selection will be anonymous with respect to the voter or user. Optionally, when roll-call voting is desired instead of anonymous voting, an identification of the inquired person can be externally linked to the device of the present invention.

Additionally, device deactivation means can be provided, such as: total destruction of the device, destruction of RFID tags in the device or deactivation of RFID tags using the "kill" command .

Referring to the figures in the drawings, some embodiments of the invention are described in detail below.

PREFERED EMBODIMENTS

Fig. 1 partially shows a device 1 in accordance with the invention, in simplified form, comprising a carrier layer or substrate 2 made of dielectric material, a RFID tag layer 3 provided with three passive UHF tags, equiangular, arranged on said carrier layer 2 and on an circumference 4 with a radius r, centred on 5 to the device 1. The three RFID tags 3 correspond to three different vote possibilities.

In order to select the desired vote, the wireless device in fig. 1 requires a RFID tag masking layer 6 as shown in fig. 2.

Fig. 2 is a partial simplified schematic perspective view of the wireless voting device in fig. 1 with the RFID tag masking layer 6, in its minimum extent version, comprising two electromagnetically opaque strips in a masking position of two of said RFID tags 3 and a RFID visibility region 7 in relation to the third tag corresponding to the desired vote.

Alternatively, fig. 3 partially shows a device 1 in accordance with fig. 1, in simplified form, comprising a RFID tag masking layer 6 which in its maximum extent version consists oaf single electromagnetically opaque film and a RFID visibility region 7 provided in the RFID tag masking layer 6 for the RFID tag 3 corresponding to the desired vote.

In fig. 2 and fig. 3, the electromagnetically opaque strips and single film of the RFID tag masking layer 6 are centrally arranged to the chip and over the RFID tag layer 3, ensuring a better performance for the device 1 in fig. 2 and 3. In this embodiment of the invention, the area defining RFID visibility zone 7 of device 1 is provided on the RFID tag masking layer 6 but without overlap with the RFID visibility zone volume and it should be centrable to the RFID tag 3.

The maximum number of RFID tags 3 on r radius circumference 4, minimum dimensions of the electromagnetically opaque single film or strips of the RFID tag masking layer 6 and RFID visibility region 7 are the previously referred as well as the materials of the carrier layer 2 and RFID tag masking layer 6.

Fig. 4 partially shows another embodiment of the device 1 in accordance with the invention, in a simplified form, comprising a carrier layer 2 made of dielectric material, a RFID tag layer 3 provided with three passive UHF tags, equiangular, arranged radially on said carrier layer 2 in relation to centre 5 of device 1, and a RFID tag masking layer 6 composed of two electromagnetically opaque strips, one for each RFID tag 3, corresponding to non desired vote options. A RFID visibility region 7 is provided in RFID tag masking layer 6, for the third RFID tag 3, corresponding to the desired vote.

As in the embodiment in fig. 2 and fig. 3, the RFID tag masking layer 6 of the device in fig. 4 may consist of a single electromagnetically opaque film.

Restrictions on the embodiment of the invention in fig. 2 and 3, in relation to the RFID tag masking layer 6 and visibility region 7 are equally applied to the embodiment of device 1 shown in fig. 4. However, the maximum number of RFID tags 3 arranged radially is now limited by the radius r of circumference 4 and by the minimum spacing between above mentioned RFID tags 3.

Fig. 5 is a cross sectional view of devices 1 in fig. 2 and fig. 4 along line A-A' of the device in fig. 2 and line B-B ' in fig. 4, respectively, with a RFID tag masking layer 6 over RFID tags 3 with the carrier layer 2 and including a dielectric outer protection layer 8.

Fig. 6 shows another alternative embodiment of the device 1 in fig. 2 and fig. 4 in cross section according to line A-A' of the device in fig. 2 and line B-B' of the device in fig. 4, provided with two RFID tag masking layers 6 and 6', respectively over and under RFID tags 3, including carrier layer 2 and outer dielectric barrier layer 8.

The embodiment of the invention in fig. 5 shows only one RFID tag masking layer 6 (overlaying the tags) and second arrangement in fig. 6 is composed of a first and second RFID tag masking layers 6 and 6' on opposed faces to the RFID tags. In the embodiment in fig. 6, the first RFID tag masking layer 6 is similar to RFID tag masking layer 6 in fig. 5 and second RFID tag masking layer 6' is provided under RFID tags 3. Using two RFID tag masking layer 6 and 6' as depicted in fig. 6 is advantageous to prevent possible accidental detections and/or maximize range of each RFID tag 3 in device 1. This happens because the lower is the area of visibility region centred to UHF RFID 3 tag possibly lower will be the maximum range of the RFID tag 3 not masked by the electromagnetically opaque material of RFID tag masking layers 6 and 6'. This being the case, using two RFID tag masking layers allows a higher number of passive UHF RFID tags 3 in the device 1 compared to the embodiment provided with only a masking layer 6.

In embodiments in fig. 5 and fig. 6, the above mentioned restrictions are applicable to sizes of the area of the RFID visibility region (not shown) and RFID tag masking layer 6 and 6' composed of electromagnetically opaque single film or strips.

However, as above mentioned, given the duplication of RFID tag masking layer 6 and 6¹ in fig. 6 the electromagnetically opaque strips length can be reduced compared to the length of the same in the embodiment in fig. 5 provided with only a RFID tag masking layer 6. The electromagnetically opaque strips width of RFID tag masking layer 6 can be any, provided it does not overlap the RFID visibility region and it is larger than RFID tags 3 width.

In cases where device 1 is reusable, the rotating layer of device 1 in fig. 2-6 both corresponds to the carrier layer 2, integral with RFID tag layer 3, and to the RFID tag masking layers 6 and 6', rotating simultaneously. In these embodiments, the attachment and rotating means matches axle 5 in figs. 1-4.

Voting device 1 can comprise one or more additional carrier layers made of dielectric material, for instance, for purposes of rotation of the layers, in case the device is reusable, over or under tag masking strips 6, 6', provided its dielectric permittivity is no higher than 3 and thickness inferior to

0.005λ₀.

In case the embodiment of the device in fig. 2-6 is disposable, visibility region 7 is achieved by means of detachment of the electromagnetically opaque material from the RFID tag masking layer (s) 6 and 6' overlapping RFID tag 3 corresponding to the desired vote.

Referring now to the embodiment of the invention depicted in fig. 7, device 1 comprises a passive UHF RFID tag layer 3, a RFID tag masking layer and a carrier layer 2 made of dielectric material. RFID tags 3 are arranged with the same orientation uniformly spaced among each other along the length of carrier layer 2. Each RFID tag corresponds to a vote option and the total number of RFID tags 3 in each device 1 depends on the size of the carrier layer 2 and size of RFID visibility region 7 and UHF wavelength.

As in embodiments in fig. 2 to 6, the operation of device 1 in fig. 7 and sizes of the area defining the RFID visibility region 7 and electromagnetically opaque strips composing the RFID tag masking layer 6 have the above mentioned restrictions.

Likewise, this embodiment can be provided with a RFID tag masking layer 6' (not depicted) .

As shown in fig. 6, it is also possible to foresee in device 1 in the embodiment of the invention in fig. 7, a second RFID tag masking layer 6' under the RFID tag layer 3, by applying to the same similar limitations regarding effective dielectric permittivities of the dielectric materials of the carrier layer 2 and outer barrier layer 8 and other additional carrier layers. In case the device 1 in fig. 7 is of the reusable type, the sliding layer of device 1 in fig. 7 corresponds to carrier layer 2 or to both RFID tag masking layers 6 and 6', provided with respective visibility regions 7 and 7' and without the volume of the same overlaps the electromagnetically opaque material of the RFID tag masking layers 6 and 6 ' .

If the device 1 in fig. 7 is disposable, the visibility region 7 is provided as referred in the embodiments of the invention in fig. 2 to 6, by detachment of the electromagnetically opaque material of RFID tag masking layer (s) 6 and/or 6' overlapping the visibility region volume that allows the detection of the RFID tag 3 corresponding to the desired vote .

In fig. 8 another embodiment of the invention is shown. Device 1 comprises a dielectric carrier substrate layer 2, with an arbitrary dielectric permittivity (e. g. , plastic) or metallic (e. g., aluminium or tin) at least two passive UHF RFID tags 3 and a RFID tag masking layer that, in this case, is composed of a number of electromagnetically opaque strips 6.

RFID tags 3 are arranged parallel and in the same direction alternating with electromagnetically opaque strips 6 constituting the RFID tag masking layer, interlinked in one of the ends by an attachment and rotating means 9.

In this embodiment, RFID tags 3 are so close as possible and they are provided in any number. Assembly of RFID tag masking layer 6 is simplified: an electromagnetically opaque strip should be provided between two RFID tags 3 for safekeeping of the elimination of possible fortuitous detections, pending from the attachment and rotating means 9. In this embodiment, the volume of RFID visibility region 7 is only exposed by rotating the selected RFID tag 3', corresponding to the vote, in relation to the attachment and rotating means 9 of the remaining RFID tags 3 of device 1. Thus, the range of the selected RFID tag 3' is not affected by the distance between the same. The method of rotating RFID tag 3 allows the selected RFID tag 3' reading.

The length and width of the electromagnetxcally opaque strips of the RFID tag masking layer 6 are equivalent to those of the embodiments in fig. 6 provided with two RFID tag masking layers, and the RFID visibility region 7 is compliant with the above stated restrictions.

Fig. 9 depicts, in accordance with the present invention, an embodiment of a voting system or other use in a congregation, composed of multiple devices 1 from fig. 1 to 6. However, also the devices in the embodiments in Fig. 7 and 8 can be used in the system.

Each system RFID reading antenna 10 is connected to a RFID reader 11 by means of an electronic switch 12 (multiplexer) allowing communication of the data broadcasted from each device 1 to an application in a computer 13, for registration and/or processing of the reading results. In another embodiment of the present invention (not represented) the system RFID reading antennas 10 are connected directly to a RFID reader 11. The identification of the vote option selected in each device 1 is made by means of a database containing the identification codes pertaining to each of RFID tags of each one of the devices.

In this voting system, only RFID tags 3 identifications regarding the vote options corresponding to devices 1 located in the region of the detection volume of one or more RFID reading antennas 10 are read.

Claims

A wireless passive voting device comprising at least a carrier layer (2) made of dielectric material having a dielectric permittivity less than 3 and a thickness less than Ο.ΟΙλο over which is arranged radially or azimuthally along a circumference (4) with a centre (5) a plurality of RFID tags (3), each RFID tag (3) corresponding to a selectable vote option or answer; at least a RFID tag masking layer (6) comprising a electromagnetically opaque single film or a plurality of electromagnetically opaque film strips arranged radially or azimuthally along a circumference (4) with a centre (5), with a generally rectangular shape, centred or centrable with said RFID tags (3) of the carrier layer (2) , and the sizes of which are larger or at least have the same size as the sizes of RFID tags (3) , a region (7) for RFID visibility and reading of RFID tag (3) provided on said RFID tag masking layer (6), centred or centrable with selected RFID UHF tag (3) and which allows detection and unambiguous identification of said RFID tag (3) corresponding to the selected vote option or answer, and optionally, an outer protection layer (8) made of dielectric material, equal or different from the carrier layer (2) .

The device according to claim 1, which comprises N RFID tags (3) and an electromagnetically opaque single film or N-l electromagnetically opaque strips, wherein N is equal or higher than 2, and in which the visibility region (7) is provided on the RFID tag masking layer (6) as a generally rectangular window, centrable by rotation sliding in the attachment and rotating means (5) or by linear sliding of the carrier layer (2) and/or masking layer (6) and/or the outer protection layer (8), with the RFID tag (3) corresponding to the selected vote option or answer, allowing reading of the same.

The device according to claim 1, wherein the number of RFID tags (3) and of electromagnetically opaque strips, centred in relation to each other, is the same, or comprised of a single film, and wherein the RFID visibility region (7) is provided on the RFID tag masking layer (6) by detachment of the electromagnetically opaque strip centred to the RFID tag (3) corresponding to the selected vote option or answer .

The device according to any one of previous claims, wherein the RFID tags (3) on the carrier layer (2) and electromagnetically opaque strips on the masking layer (6) are arranged along a circumference (4) , and the maximum number of RFID tags (3) on the carrier layer (2) over a r radius circumference (4) within the device is less than

2nr

wherein Le is the larger dimension of the RFID tag (3) and λ₀ is the wavelength in free space.

5. The device according to any one of claims 1 to 3, wherein RFID tags (3) on the carrier layer (2) and the electromagnetically opaque strips on the RFID masking layer (6) are radially arranged, and wherein the minimum distance

2 between two adjacent RFID tags (3) and between two adjacent masking strips is higher than 0.04λ₀, respectively.

The device according to any one of claims 1 to 3, wherein RFID tags (3) on the carrier layer (2) and the electromagnetically opaque strips on the RFID masking layer (6) are arranged in a parallel and uniformly spaced mode along the length of the carrier layer (2), and wherein the minimum distance between two adjacent RFID tags (3) and between two adjacent masking strips is higher than 0.04λ₀, respectively .

The device according to any one of previous claims, further comprising a second RFID tag masking layer (6'), similar to the masking layer (6), arranged over or under RFID tags (3) , and wherein the length of the electromagnetically opaque strips of both masking layers (6, 6') is reduced at least to 70% compared to the length of the same, the width being equal or greater than the width of RFID tags (3) .

The device according to any one of previous claims, wherein the width Wj and length Lj minimal size of the RFID visibility region maintaining the RFID tag (3) range are determined according to the following formula

Wj = We+0.15A₀ and Lj = Le+0.02A₀ wherein We is the passive UHF RFID tag width, Le is the length of the passive UHF RFID tag, and λ₀ is the UHF wavelength .

Wireless voting device of the "pocket-knife" type comprising a plurality of RFID tags (3) with a hole provided on one end; a plurality of electromagnetically opaque strips for masking (6) RFID tags (3, 3') with a hole provided on one end, arranged alternately to said RFID tags (3) and following the same orientation; optionally, two carrier and protection layers (2) , in metal or dielectric material, with an arbitrary dielectric permittivity, and also provided with a hole on one end; and attachment means (9) of said RFID tags and said masking electromagnetically opaque strips (6), preferably an axle, passing through the tags, electromagnetically opaque strips and barrier layers holes, also appropriate to rotate RFID tag (3') corresponding to the selected vote option or answer and generation of the visibility region (7')/ allowing the exhibition, detection and reading of RFID tag (3' ) .

10. The device according to the previous claim, wherein the length of the electromagnetically opaque strips of masking layers is reduced at least to 70% compared to the length of RFID tags (3) , and in that the width is equal or greater than the width of RFID tags (3) , and in that the visibility region (7) is as defined in claim 8.

11. The device according to any one of claims 1-8 and 9-10, wherein the electromagnetically opaque single film and strips of the masking layer (6) are comprised of an electromagnetic radiation absorbing or reflective material selected from a metallic material, absorbing graphite or other electromagnetically opaque material.

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12. The device according to the previous claim, wherein the electromagnetically opaque single film and strips are metallic, preferably aluminium foil or tin foil.

13. An wireless RFID voting system for reading and counting of votes or answers provided with one or multiple devices (1) according to anyone of previous claims comprising at least a voting device (1), at least a RFID reading antenna (10) connected to a RFID reader (11), directly or by means of an electronic switch (12) (multiplexer), such as to allow communication of data broadcasted by RFID tag(s) (3) selected in the voting device (s) (1) to a computer application (13) , for registration and/or processing of the reading results, the identification of selected vote option or answer in each device (1) being performed by means of identification codes related to each of RFID tags (3) of the device (s) (1) .

14. The system according to claim 13, wherein the system has the identification of each inquired person assigned to each voting device (1) .

15. The system according to claims 13 or 14, further comprising the attachment of appropriate deactivation means of the device such as the "kill" command.

16. A voting method comprising the steps of: selecting in at least one voting device (1) according to any one of claims 1 to 12, the desired vote option or answer, by exhibiting the corresponding RFID tag (3) , on the RFID visibility region (7), by rotation, sliding or detachment of the electromagnetically opaque masking strip;

5 interrogating by means of at least a UHF RFID reading antenna (10), the non desired RFID tags (3) covered by RFID tag masking layer (s) (6) remaining not detected; broadcasting by the RFID tag (3) of the assigned identification code; processing by means of a RFID reader (11) connected to said UHF RFID reading antenna (10), directly or by means of an electronic switch (12) (multiplexer), that returns the identification in RFID tag (3) corresponding to the vote option or answer selected by the user; and processing the reading data in a dedicated and centralized database or in a computer (13) having the corresponding vote option or answer assigned to each RFID tag (3) of each device ( 1 ) .

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