FR3109043A1 - SYSTEM AND METHOD FOR LOCATING AND IDENTIFYING, ON A TOUCH SURFACE, MOBILE ELEMENTS PROVIDED WITH AT LEAST ONE TAG USING NEAR FIELD COMMUNICATION TECHNOLOGY - Google Patents

Abstract

The present invention relates to a system (1) for identification and location on a tactile surface (12) of a mobile element (14) comprising a tag (16) of the near-field communication type, said system (1) comprising: an emitter (3) generating an electromagnetic field; a mobile element (14) comprising a tag (16) using near-field communication technology, said tag (16) which, on the one hand, comprises a conductive surface (12) configured so that its electrical state is modified in presence of a first electromagnetic field and, on the other hand, is configured so that an identifier is emitted in the presence of a second electromagnetic field; a tactile surface (12) configured to detect the position of a movable member (14) of which a conductive surface (16) is in a modified electrical state; a receiver (17) configured to receive the identifier sent by said tag (16); an electronic module (18) connected to the touch surface (12) and to said receiver (17), said module (18) being configured to associate the position information supplied by the touch surface (12) with the identifier received by said receiver (17).

Description

SYSTEM AND METHOD FOR LOCATING AND IDENTIFYING, ON A TACTILE SURFACE, MOBILE ELEMENTS PROVIDED WITH AT LEAST ONE TAG USING NEAR FIELD COMMUNICATION TECHNOLOGY

The present invention relates to a system and a method for identifying and locating, on a tactile surface, at least one mobile element comprising at least one tag using near-field communication technology.

It will be noted that near field communication technologies include in particular NFC (abbreviation in the English terminology meaning “Near Field Communication”) or RFID (from English “Radio Frequency Identification”) technologies. The French language equivalent of NFC being the acronym CCP for “Communication en Champ Proche”. The terms “near field communication” will preferably be used below to designate NFC and RFID technologies but also related technologies, that is to say any communication by electromagnetic waves (radio waves in particular) taking place over distances of a few centimeters.

Nowadays, there are touch surfaces in many electronic devices, such as tablets, in particular at their screens which are touch screens configured to detect the position of a stylus or the fingers of a user on their surface . Touch surfaces in the form of a touchpad (also known as a "trackpad") are also found on laptops and various electronic devices.
Thus, in many situations, it may be necessary to identify and detect the position of moving objects placed on a touch surface, for example in the field of games, in particular when a touch tablet is used as a game board. society and interacts with hardware game pieces.

One way to detect physical objects, such as game pieces, on a tablet's touchscreen is to cover the pieces with a conductive material. Thus, when the user touches the game piece placed on the touch screen of the tablet, the conductive paint ensures contact between the user's hand and the touch surface and a contact point advantageously placed under the game piece. This makes it possible to simulate a tactile "touch", which the touch pad can then locate. By placing several contact points under the game piece, according to particular geometries, it is possible to distinguish different pieces arranged on the touch surface, each having a specific “geometric signature”.
However, this solution has the drawbacks, on the one hand, of requiring the part to be touched in order for it to be identified and located, and, on the other hand, of limiting the number of different identifiable parts due to the reduced possibilities of distinct geometric signatures.

It should be noted that by touch pad is meant any electronic device comprising a touch screen, said device being generally ultra-flat and providing substantially the same functions as a laptop computer.

Thus, the present invention at least partly solves the problems mentioned above by proposing a new system for identifying and locating on a tactile surface of at least one mobile element comprising at least one tag of the near-field communication type, said system comprising:
- a near field communication type transmitter generating at least one electromagnetic field;
- at least one mobile element comprising a tag using near-field communication technology, said tag which, on the one hand, comprises a conductive surface configured so that its electrical state is modified in the presence of a first electromagnetic field and, d on the other hand, is configured so that an identifier is transmitted in the presence of a second electromagnetic field, said fields being generated by said transmitter;
- A touch surface configured to detect the position of at least one movable element having at least one conductive surface in a modified electrical state when said element, in particular its conductive surface, is in contact with said touch surface;
- A receiver configured to receive the identifier transmitted by said at least one tag;
- an electronic module connected to the touch surface and to said receiver, said module being configured to associate the position information provided by the touch surface with the identifier received by said receiver.

The invention also relates to a method for identifying and locating, on a tactile surface, at least one mobile element comprising at least one tag of the near-field communication type, said tag comprising a conductive surface configured so that its electrical state is modified in the presence of an electromagnetic field and, on the other hand, to emit an identifier in the presence of an electromagnetic field,
said method comprising the following steps:
- emission of a first electromagnetic field, for example of the near-field communication type, close to the touch-sensitive surface;
- Modification of the electrical state of the conductive surface of the tag following reception of said first electromagnetic field;
- detection of the position by the tactile surface of the movable element via the conductive surface whose electrical state is modified, in particular if the movable element, for example via its conductive surface, is arranged on the touch surface;
- emission of an identifier from the tag of said mobile element;
- reception of the identifier emitted by the tag of said mobile element following the reception of a second electromagnetic field by said tag;
- association of the identifier and the position of said element to enable an identified element to be located on said touch surface.

According to one possible characteristic, said tag is passive.
The fact that the tag is passive means that it does not have its own power source. More particularly, said tag is configured to be supplied with electrical energy by the transmitter, thanks to the electromagnetic fields emitted by the latter and received by said tag. This configuration has the advantage of simplifying the design and manufacture of said tags, as well as reducing its manufacturing cost.

According to another possible characteristic, the first electromagnetic field is permanent and/or non-modulated.

According to another possible characteristic, the emission of the second electromagnetic field, for example by the transmitter, is triggered by the detection of a tactile touch by the tactile surface.
This can be caused by the conductive surface of a tag, by a finger or any object likely to be recognized as a touch point or tactile touch.

According to another possible characteristic, the second field is a modulated electromagnetic field.

According to another possible characteristic, the first and second electromagnetic fields are one and the same electromagnetic field, that is to say there is only one field which triggers the modification of the electrical state of the conductive surface and the emission of the identifier by the tag. Said electromagnetic field is therefore not emitted conditionally, but independently with respect to the detection of a tactile touch by the tactile surface. Said field is for example transmitted continuously, or cyclically. Said field can also be initially unmodulated and then be modulated following the detection of a tactile touch on the tactile surface.

According to another possible characteristic, said tag comprises a near-field reception antenna, a switch connected to said antenna, as well as to said conductive surface and to an electrical ground.

According to another possible characteristic, said tag is configured so that the switch connects the conductive surface to a ground when the antenna receives an adequate electromagnetic field (for example the second electromagnetic field emitted by said transmitter).

According to another possible characteristic, said switch is a transistor.
Said transistor is for example a transistor of the bipolar or field effect type.

According to another possible feature, the system includes a touch pad; the receiver, the transmitter, the touch surface and/or the electronic module being arranged in said touch pad.

According to another possible characteristic, the transmitter is an antenna surrounding said touch surface.
This arrangement of the antenna (or of the transmitter) makes it possible to generate a near electromagnetic field above said touch-sensitive surface and therefore to optimize the energy necessary for the production of such a field.

According to another possible characteristic, said at least one mobile element comprises several tags or several conductive surfaces per tag arranged asymmetrically (this may be the tags or the conductive surfaces).

The invention also relates to a tag of the near-field communication type, characterized in that it comprises an antenna, a conductive surface, as well as a chip connected to the antenna and to said conductive surface,
said chip being configured to modify the electrical state of the conductive surface if the antenna receives an adequate electromagnetic field.
The change of electrical state of the conductive surface can be for example a grounding of the conductive surface, the sending of a current or voltage pulse, or the fact of transferring electrical energy to a device. third party via said conductive surface.

This tag architecture has the advantage of being simple and adding new features. For example, with the tag according to the invention, it is easy to count tags placed on a conductive plate, by activating them so that they emit a signal via their respective conductive surfaces through the plate, a device connected to the plate that can count the number of signals emitted and therefore determine the number of tags present.

According to one possible characteristic, the adequate electromagnetic field is a signal containing a command that can be interpreted by said chip connected to said antenna.

According to another possible characteristic, said chip is configured to emit a signal containing an identifier via the antenna of said tag, for example following the reception of a signal containing a command interpretable by said chip.

According to another possible characteristic, said conductive surface of said tag is a connector, for example electrical, such as a POGO connector.
The fact that the conductive surface of the tag is a connector makes it possible, for example, to electrically supply a third-party device connected via said connector, but also to control this supply by managing the electromagnetic field to which the tag is exposed. The tag can also be configured so that a change in the state of the connector triggers a change in state or function of the connected third-party device.

The invention will be better understood, and other aims, details, characteristics and advantages thereof will appear more clearly during the following description of particular embodiments of the invention, given solely by way of illustration and not limitation, with reference to the accompanying drawings, in which:
- Figure 1, referenced, is a very schematic representation of an identification and location system according to the invention;
- Figure 2, referenced , is a very schematic representation of the various functional elements of a tag of a mobile element of the system of Figure 1.
- Figures 3a, 3b and 3c, respectively referenced , [Fig. 3b] and [Fig. 3c], are very schematic representations, seen from above, of different embodiments of the tag of figure 2.

Figure 1, referenced is a very schematic representation of a system 1 for identifying and locating, on a tactile surface, mobile elements comprising at least one NFC tag (or of the near field communication type).

Said system 1 comprising:
- a transmitter 3 of the near-field communication type generating at least one electromagnetic field, said at least one generated field has for example a frequency between 10 and 16 MHz (and complies with the standards in particular ISO/IEC 14443, ISO/IEC 18000-3 and/or ISO.IEC 15693);
- A touch surface 12, such as a touch screen of a touch pad 13 (said touch surface can be resistive or capacitive);
- one or more mobile elements 14, such as a game piece or a figurine, comprising one or more tags 16 using near-field communication technology;
- A receiver 17 configured to retrieve an identifier transmitted by a transmitter of the near-field communication type, such as one of said tags 16;
- an electronic module 18 connected to the touch surface 12 and to said receiver 17, said module 18 being configured to associate the position information provided by the touch surface and the identifier received by the receiver 17.

The transmitter 3 comprises for example an antenna which may be included in the touchpad 13 or arranged in a separate separate module. In addition, in a variant embodiment not shown, said near field communication transmitter 3 surrounds said touch surface 12.

The tactile surface 12, for its part, can in particular be a game board, part of the surface of which is tactile.

The tag 16 of said mobile element 14, more particularly visible in FIG. 2 (referenced ), thus comprises:
- A communication module 22 of the near-field communication type;
- at least one conductive surface 24 configured so that its electrical state is modified, such as being grounded, in the presence of an electromagnetic field and to interact with the touch surface 12;
- An antenna 26 making it possible in particular to transmit and/or receive electromagnetic signals, for example of the near-field communication type.

Said tag 16 may also comprise an electronic chip 27 which comprises a storage memory in which the identifier of said tag 16 is stored, said chip 27 is also configured to interpret the messages received via the antenna 26 and compose response messages transmitted via said antenna 26 (message containing for example said identifier). Indeed, the transmission of a message containing an identifier is generally carried out following a particular command, that is to say that the transmitter 3 transmits a signal capable of being decoded by an element of the tag, such as the dedicated chip 27 (said chip storing an identifier and being configured to encode the response message comprising the identifier in the transmitted signal).

More particularly, said communication module 22 comprises a switch 28 connected to said antenna 26, to said conductive surface 24, and to an electrical ground G.

Said tag 16 is preferably a passive component, that is to say that it does not include an energy source (it is therefore not energy independent), but is electrically powered from the outside, here thanks to to the energy received via the antenna 26.

Indeed, when the antenna 26 receives electromagnetic fields generated by the transmitter 3 of said system 1, part of the energy received makes it possible to transmit a message comprising an identifier specific to the tag (more particularly to the chip 27 which is itself specific to said tag 16), while the other part of the energy received makes it possible, via switch 28, to connect conductive surface 24 to electrical ground G.

It will be noted that the switch 28 is for example a transistor, bipolar or field effect, whose emitter is connected to ground G, the collector to the conductive surface 24 and the base to the antenna 26.
Said communication module 22 may also comprise a diode 30 located between the base of transistor 28 and antenna 26 and/or a capacitor 32 arranged on a branch connecting a point between diode 30 and the base of transistor 28 to ground G. Diode 30 makes it possible in particular to force the direction of the current from antenna 26 towards the base of transistor 28. Capacitor 32, for its part, makes it possible to rectify the voltage at the input of the base of transistor 28 (the example shown below). above is based on a bipolar transistor, but can also be applied with a field effect transistor).

It will be noted that the conductive surface 24 is, for example metallic, wide enough for it to be detectable by the tactile surface 12 (generally a surface comparable to that of the end of a human finger, i.e. approximately 1 cm2 , so that it can be detected by said touch surface as a tactile touch).

Thus, when switch 28 is open, conductive surface 24 has a high impedance value, but, when switch is closed, conductive surface 24 is connected to ground G and is therefore at ground potential ( there is therefore a change in the electrical state of said conductive surface).

Thus, when positioning a mobile element 14 comprising a tag 16 on the tactile surface 12, the presence of the electromagnetic field generated by the transmitter 3 causes the grounding of the conductive surface 24 and the detection of a tactile touch. , via said conductive surface 24 grounded, at the touch surface 12. There is also emission of an identifier, generally unique, by said tag 16. The emission of the signal containing the identifier is for example triggered by the electromagnetic field emitted by the transmitter 3 having caused the grounding of the conductive surface 24.
In a variant embodiment, the electromagnetic field emitted by the transmitter 3 sees its state modified (for example said field becomes modulated) following the detection of a touch touch by said touch surface 12, the emission of the identifier by the tag 16 being triggered under the condition of receiving an appropriately modulated electromagnetic field.

In another variant embodiment, the transmitter 3 is configured to emit first and second separate electromagnetic fields, the first electromagnetic field triggering the change of electrical state of the conductive surface 24 of a tag 16, while the second field electromagnetic triggers the emission of the tag identifier 16.
The emission of the second electromagnetic field is for example triggered (in particular by the electronic module 18) provided that the tactile surface 12 detects a tactile touch.

Thus, whatever the alternative embodiment, the module 18 receives, on the one hand, via the receiver 17, the signal comprising the identifier transmitted by the tag 16 and transmits it to said module 18, and, on the other hand, via the tactile surface 12, the location of the zone where there has been a tactile touch. It will be noted that the module 18 can be connected directly to the touch surface 12 or indirectly, by means of a third element, such as the receiver 17 or the transmitter 3.

The electronic module 18, connected to the touch surface 12 and to the receiver 17, therefore associates the position of the contact detected at the level of the touch surface 12 with the identifier received by the receiver 3. The electronic module 18 is thus configured to identify and locate the position of a mobile element 14 comprising a tag 16 placed on a touch surface 12.
Furthermore, said module 18 comprises a memory making it possible to store information, such as the identifiers received, the position coordinates of the mobile elements and their association.

In addition, said electronic module 18 is configured to perform one or more of the following actions:
- recover the coordinates of at least one conductive surface on the touch surface;
- Store in memory, for example in the form of a list, identifiers and positions of their contact points on the touch surface;
- periodic verification of the contact areas of said touch surface and of the identifiers emitted by said tags, in order to detect the appearance or disappearance of a tag (and more particularly of the element comprising the tag) on the touch surface, this detection being done by comparison with the data received during a previous detection.

Note that if a new identifier has appeared in relation to the list of stored identifiers, but no new tactile contact position has appeared, then the new tag (and more particularly the identifier specific to it) has appeared n is not processed. It may be a tag using near-field communication technology, but without a conductive surface. The list, stored in memory, of the identifiers and positions of the tactile contacts is maintained unchanged.

On the contrary, if an identifier has disappeared from the list of identifiers stored in memory, this indicates the disappearance of one of the tags using a communication technology in the near field of the touch surface. The previously recorded corresponding association is deleted and the list of identifiers and positions of touch contacts is updated, respectively by deleting the missing identifier and the position of touch contact associated with this identifier.

In variant embodiments represented in FIGS. 3a to 3c, referenced respectively , [Fig. 3b] and [Fig. 3c], the tags 16, 16' or 16'', according to the invention can comprise one or more conductive surfaces 24.

More particularly, when the tag 16 comprises several conductive surfaces 24, at least two, it is possible to detect the rotation of an element 14 via the tactile surface 12. Moreover, when the tag 16 comprises at least three conductive surfaces 24 arranged asymmetrically, it is possible to detect the rotation of said element 14 and its orientation (it is in fact possible to define a reference point and to determine its orientation relative to it). In this variant embodiment, it is the electronic module 18 which is configured to determine the rotation and/or the orientation of the elements 14 comprising the appropriate number of conductive surfaces 24.

The system according to the invention thus makes it possible to know in real time the number of tags present, using near field communication technology, in contact with a touch surface, the identifiers of these tags as well as their position on said touch surface.

In a variant embodiment not shown, the electronic module, the transmitter and the receiver are included in a touch pad. The transmitter and receiver may otherwise be a single module, such as an antenna.

It will also be noted that the communication module 22 of the tag 16, 16' or 16'' can be a chip of the near-field communication type, connected, on the one hand to an antenna 26 and, on the other hand, to one or several conductive surfaces 24. The chip and the elements 22 and 24 can be mounted on a substrate, for example insulating, this assembly is also referred to as a “tag inlay”.

The invention also relates to a tag of the near-field communication type which comprises at least one antenna 26, a conductive surface 24, as well as a chip 22 connected to the antenna 26 and to said conductive surface 24.

Said chip 22 is configured to send a signal to the conductive surface if the antenna 26 receives the appropriate electromagnetic field.

Said signal emitted by chip 22 can be, for example, grounding of conductive surface 24 as previously described, or sending a current or voltage pulse.

It will be noted that the antenna 26 of the tag is configured to receive an adequate electromagnetic field (for example of the near field communication type) or a signal containing a command which will be transmitted to the chip 22, said chip 22 being capable of interpreting the signal received and trigger operations accordingly. In particular, the operation of changing the electrical state of the conductive surface 24, either connecting the conductive surface 24 to an electrical ground or by sending an electrical signal to said surface.

In a variant embodiment not shown, said conductive surface (or said contact point) is a connector, for example electrical, such as a POGO connector.

In another variant embodiment not shown, the system according to the invention can be configured to sequence the activation of the tags so as to sequentially recover the coordinates of the conductive zones on the touch surface, this in order to allow the identification and localization different tags on a touch surface (note that this application can be performed on a non-touch, but electrically conductive surface).

Claims (11)

System (1) for identification and localization on a tactile surface (12) of at least one mobile element (14) comprising at least one tag (16) of the near-field communication type, said system (1) comprising:
- a transmitter (3) of the near-field communication type generating at least one electromagnetic field;
- at least one mobile element (14) comprising a tag (16) using near-field communication technology, said tag (16) which, on the one hand, comprises a conductive surface (12) configured so that its electrical state is modified in the presence of a first electromagnetic field and, on the other hand, is configured so that an identifier is transmitted in the presence of a second electromagnetic field, said fields being generated by said transmitter (3);
- a tactile surface (12) configured to detect the position of at least one movable element (14) having at least one conductive surface (16) in a modified electrical state when said element (14) is in contact with said surface tactile;
- a receiver (17) configured to receive the identifier transmitted by said at least tag (16);
- an electronic module (18) connected to the touch surface (12) and to said receiver (17), said module (18) being configured to associate the position information provided by the touch surface (12) with the identifier received by said receiver (17). System according to the preceding claim, characterized in that said tag (16) is passive. System according to any one of the preceding claims, characterized in that the emission of the second electromagnetic field is triggered by the detection of a tactile touch by the tactile surface (12). System according to claim 1 and 2, characterized in that the first and second electromagnetic fields are one and the same electromagnetic field. System according to any one of the preceding claims, characterized in that the said tag (16) comprises a near-field reception antenna (26), a switch (28) connected to the said antenna (26), as well as to the said surface conductive (24) and to an electrical ground (G). System according to the preceding claim, characterized in that said tag (16) is configured so that the switch (28) connects the conductive surface (24) to a ground (G) when the antenna (26) receives an adequate electromagnetic field . System according to any one of the preceding claims, characterized in that it comprises a touch pad; the receiver (17), the transmitter (3), the touch surface (12) and/or the electronic module (18) being arranged in said touch pad. Method for identifying and locating, on a tactile surface (12), at least one mobile element (14) comprising at least one tag (16) of the near-field communication type, said tag (16) comprising a conductive surface (24) configured so that its electrical state is modified in the presence of an electromagnetic field and, on the other hand, to emit an identifier in the presence of an electromagnetic field,
said method comprising the following steps:
- emission of a first electromagnetic field close to the touch surface (12);
- modification of the electrical state of the conductive surface (24) of the tag (16) following reception of said first electromagnetic field;
- detection of the position by the tactile surface (12) of the movable element (14) via the conductive surface (24) whose electrical state is modified;
- emission of an identifier from the tag (16) of said mobile element (14) following the reception of a second electromagnetic field by said tag (16);
- receipt of the identifier transmitted by the tag (16) of said mobile element (14);
- association of the identifier and the position of said mobile element (14) to enable an element (14) identified on said touch surface to be located. Method according to the preceding claim, characterized in that the emission of the second electromagnetic field is triggered by the detection of a tactile touch by the tactile surface (12). Method according to Claim 8, characterized in that the first and second electromagnetic fields are one and the same electromagnetic field. Tag (16) of the near field communication type, characterized in that it comprises an antenna (26), a conductive surface (24), as well as a chip (22) connected to the antenna (26) and to said conductive surface (24), said chip (22) being configured to change the electrical state of the conductive surface (24) if the antenna (26) receives an adequate electromagnetic field.