FR2775373A1 - Sliding contact for microcircuit cards and reader using said contact, which is omnidirectional, compact, easily installed and economical - Google Patents

Abstract

A cage (3) is formed in a plate (9) to contain a ball (5). The ball is spring loaded by a metal strip (51) which is deflected downwards to make contact with a printed circuit track when a card passes over the plate (9). The omnidirectional compact contact enables very small card readers to be made which may be fitted to common objects such as wristwatches and key rings

Description

CHIP CARD CONNECTOR AND READER
COMPRISING SUCH A CONNECTOR.

 The present invention relates mainly to a connector and to a smart card reader comprising such a connector.

 Electronic microcircuit cards called smart cards benefit from advanced standardization (ISO), in particular as regards their geometry and the arrangement of the electrical input / output contacts.

 This standardization allows the mass production of card readers. The miniaturization of these readers, desired by consumers, is hampered by the constraints linked to the sliding contact connectors available using flexible blades associated with a limit switch contact for establishing the interrogation current of the card. The correct functioning of these contacts can only be guaranteed for a single direction of insertion of the card into the reader. As a result, card readers of known types have a guide passage extending on the two opposite sides of the card.

 One of their dimensions is therefore greater than the width of the smart card and the readers of known types therefore have a significant bulk.

 It is therefore an object of the present invention to provide connectors in particular for smart cards making it possible to produce more compact readers.

 It is also an object of the present invention to provide an omnidirectional connector, that is to say a connector capable of establishing electrical contacts whatever the direction of insertion of a card, in particular of the card type. smart.

 It is also an object of the present invention to provide a particularly reliable connector.

 It is also an object of the present invention to provide a connector whose mounting is particularly easy, in particular during the assembly of a smart card reader.

 It is also an object of the present invention to provide a connector whose cost price is moderate.

 It is also an object of the present invention to provide a compact, reliable and / or moderate cost chip card reader comprising such a connector.

 It is also an object of the present invention to provide an apparatus incorporating a compact smart card reader.

 These objects are achieved by a connector according to the present invention, at least one of the contacts of which comprises a ball enclosed in a cage provided with two openings arranged opposite, at least one of which has a diameter less than the diameter of the ball. .

 Advantageously, an elastic return element, a helical spring or a strip, applies the ball to the periphery of one of the openings so that a spherical cap protrudes from the opening to establish contact with the corresponding contact d '' electronic equipment, preferably a smart card. The opposite spherical cap or, advantageously the elastic return means, establishes contact at the level of a plate or of a track of a printed circuit. The spring can be held captive in a well or, advantageously, be welded to the plate or to the track with which contact is to be made. The strip can be fixed on a plate in which the cages are formed. In a first variant, use is made of standard balls and springs available commercially at extremely low prices.

 Alternatively, balls and / or springs with excellent electrical conductivity and / or excellent surface condition are used. In this case, use is made, for example, of balls and springs of copper or aluminum or else of balls and / or springs of gilded steel or coated with silver or nickel, the structure of which makes it possible to obtain the contact pressure. required by the current ISO standard. The balls can be arranged in a square, staggered, aligned or other matrix.

 The main object of the present invention is a connector, in particular for a smart card, comprising at least one electrical contact, characterized in that said contact comprises a rigid solid conductive part retained in an insulating cage provided with a first opening allowing a portion to protrude. of the solid conductive part so as to establish an electrical contact, as well as a second opening for establishing electrical contacts with a conductor of a connector support or with a conductor electrically connected to a conductor of the connector support.

 The invention also relates to a connector, characterized in that the solid rigid parts have a spherical or substantially spherical shape.

 The invention also relates to a connector, characterized in that said contact comprises an elastic return element applying the rigid, solid, conductive part on a periphery of the first opening of the cage so that part of this rigid conductive solid part protrudes from the cage.

 The invention also relates to any connector of the preceding claims characterized in that the return element is a helical spring made of conductive material.

 The invention also relates to a connector, characterized in that it comprises a plurality of electrical contacts and in that it comprises two insulating plates in which are formed cavities arranged facing each other.

 The invention also relates to a connector, characterized in that the cavities formed in the plates have a frustoconical shape and in that the cavities of the same cage are aligned along a common axis and are joined by their flared base.

 The invention also relates to a connector, characterized in that each cage has a cylindrical middle portion extended on each of its ends by a truncated cone tapering towards the visible faces of the plates.

 The invention also relates to a connector, characterized in that it comprises a strip, conductive, elastic applying the rigid solid conductive piece around the periphery of the first opening and in that said strip is fixed to an insulating plate in which the cage is formed.

 The invention also relates to a connector, characterized in that the strip has an opening for the passage of a fixing stud on a plate comprising a plurality of cages.

 The invention also relates to a smart card reader, characterized in that it comprises such a connector.

 The invention also relates to a chip card reader, characterized in that it comprises a limit switch placed at the location of the corner of the chip card after its insertion into the reader.

 The invention also relates to an electronic device comprising an electrical supply and display means, characterized in that it comprises a smart card reader, in that the supply of the electrical appliance supplies the supply of the smart card reader and in that the display means ensure the display of the reading result of the smart card.

The invention will be better understood by means of the description below and the appended figures given as nonlimiting examples in which
- Figure 1 is a sectional view of a first embodiment of a connector according to the present invention before assembly;
- Figure 2 is a sectional view on a larger scale of a detail of Figure 1 after assembly;
- Figure 3 is a perspective view of a connector according to the present invention during assembly;
- Figure 4 is a partial sectional view of electronic equipment comprising a connector according to the present invention
- Figure 5 is a sectional view of a second alternative embodiment of the connector according to the present invention
- Figure 6 is a sectional view of a third alternative embodiment of the connector according to the present invention
- Figure 7 is a top view of the preferred embodiment of a smart card reader according to the present invention in which has been inserted a smart card during reading;
- Figure 8 is a side view of the reader of Figure 7;
- Figure 9 is a perspective view of a wristwatch comprising a card reader according to the present invention
- Figure 10 is a sectional view of a fourth (preferred) alternative embodiment of the connector according to the present invention
- Figure 11 is a sectional view of a fifth alternative embodiment of the connector according to the present invention
- Figure 12 is a sectional view of a sixth alternative embodiment of the connector according to the present invention.

 In FIGS. 1 to 12, the same references have been used to designate the same elements.

 In FIGS. 1 to 4, a first embodiment of a connector 1 according to the present invention can be seen comprising at least one electrical contact comprising a cage 3 retaining a conductive ball 5.

 Advantageously, all the balls of the same connector have the same diameter.

 In the illustrated embodiment, each cage 3 is formed by placing opposite two cavities 7 formed in two plates 9.1 and 9.2 of insulating material.

 In a first embodiment, the cavities 7 have a frustoconical shape, are aligned along a common axis 11 and joined by their flared bases 13 whose diameter is advantageously slightly greater than the diameter of the ball 5. The tops 15 of the cavities 7 have a diameter smaller than that of the ball so as to prevent it from leaving the cage 3.

 Thus, as illustrated in Figures 2 and 3, a spherical cap of the ball 5 can emerge from the cage 3 so as to establish the desired contact.

 If necessary, to avoid the balls being too close, in particular if one wants to increase their diameter, one can arrange the balls not aligned but staggered and use the tolerance authorized by the dimensions of the contacts of the chip.

 FIG. 2 illustrates a cage 3 of a connector according to the present invention particularly well suited for making connections with a smart card. The cage 3 of FIG. 2 comprises a cylindrical middle part 3.1 extended on each of its ends by a truncated cone which tapers towards the visible faces of the plates 9.1 and 9.2.

 It is understood that the use of laminar structures comprising three or more plates, in which the cages 3 are formed, does not depart from the scope of the present invention.

 Similarly, the implementation of a single plate directly applied to a support 21, in particular on a printed circuit does not depart from the scope of the present invention.

 To be able to retain the balls, the plate or plates are made of a non-deformable insulating material, and without creep, such as for example glass or ceramic or, preferably, polyamide 6.6 loaded with 30% glass fiber or else Ertalite plastic sold under the trade name "ARNITE". In an exemplary embodiment, each plate has a thickness of 1 mm, the ball 5 has a diameter of 2 mm, the cylinder 3.1 has a diameter of 2.2 mm and the tops of the cones opening onto the surface of the plates 9.1 and 9.2 have a diameter of 1.78 mm.

Advantageously, the stroke of the balls makes it possible to make up for variations in the thickness of the cards to be read. The cones form an angle a with the plane of the plates 9.1 and 9.2 equal to 70 ".

 These dimensions allow sufficient travel of the ball to ensure reliable contact with a smart card standardized according to the ISO standard, in particular with unembossed cards.

 The plates 9.1 and 9.2 advantageously include positioning and / or assembly means, between them, or with a printed circuit. For example, a first plate has pins, the other plate has holes for receiving pins.

 In the advantageous example illustrated, the plates 9.1 and 9.2 comprise two holes 17 for receiving a screw 19 for fixing on a support 21 of the printed circuit type or the like.

 Elastic conductive return means 23, for example a metal spring, in particular a helical spring, or a stud made of conductive elastomer, ensures the return of the ball 5 towards the working condition in which the spherical cap protrudes from the opening 15. The elastic return means 23 can be secured to the ball, in particular by welding, be secured to the support 21, in particular by welding (see FIG. 3) or be introduced into a well 25 formed in the support 21 (see FIG. 4) or in plate 9.2 (not shown).

 We will now explain the method of manufacturing and mounting the connector 1 according to the present invention.

 First of all, the plates 9.1 and 9.2 are produced from insulating material comprising the cavities 7 and the desired openings 17. The plates 9.1 and 9.2 are advantageously identical.

 In a first embodiment, the number of openings 7 corresponding to the number of contacts to be made, for example equal to 5, 6 or 8, is made directly in the plates 9.1 and 9.2.

 As a variant, a large plate is produced, for example by molding, the cutting of which provides a plurality of plates 9.1 and / or 9.2. The balls 5 are arranged in the cavities 7 of the lower plate 9.2 which are then covered with the upper plate 9.1.

The assembly constituted by the plates 9.1 and 9.2, the cages 3 of which are filled with balls 5, is arranged on the support itself advantageously provided with elastic return means 23. The assembly is carried out by screwing, gluing, welding or the like .

 In FIG. 10, one can see an alternative embodiment of the connector according to the present invention comprising a plate 9 advantageously of reduced thickness, for example to 1.5 mm, in which each cage 3 for receiving the ball 5 is closed by a metal strip 51 comprising a first end supporting the ball 5 and a second end comprising an opening for the passage of a stud 53 for fixing on the plate 9. The strip 51 making a spring ensures the erection of the ball 5, as illustrated in ia left part of FIG. 10. When the card exerts a force symbolized by the arrow 55, the ball lowers and ensures contact at 57 between the strip 51 and the support of the connector, for example a track of a printed circuit . When the force 55 is released, the strip 51 exerts an elastic restoring force allowing the erection of the ball, as illustrated on the left side of FIG. 10. The rise of the strip 51 interrupts the contact between this strip and the support .

 As a variant, the connection is established permanently, for example by welding at the second ends of the strips 51. This alternative embodiment makes it possible to reduce the thickness of the plate to 1 mm.

 In Figure 11, we can see an alternative embodiment of the connector according to the present invention in which each cage 3 is closed by a conductive foam 59 acting as a spring.

 In FIG. 12, one can see an exemplary embodiment of the connector according to the present invention comprising a plate 61 of insulating foam, in particular an insulating foam made of elastomer or plastomer with closed cells or with open cells. An opening 63, for example cylindrical with an axis 11, is formed under each ball 5. A contact 65 is formed on the printed circuit 21 at the end of the opening 63 opposite to that on which the ball 5 rests. absence of card 27, the foam 61 ensures the erection of the ball 5 without contact of the latter with the contact 65 of the printed circuit 21. On the contrary, during the insertion of a card 27, the ball is pushed in the cage 3 and crushes the foam 61 with establishment of contact through the opening 63 between the ball 5 and the contact 65 of the printed circuit 21. When the card 27 is removed, the ball 5 rises in the cage 3, under the action of the elasticity of the foam 61 and the contact is interrupted.

 As a variant, a plate 61 made of insulating foam is used, comprising regions of conductive foam arranged opposite the balls and contacts of the printed circuit.

 In a first alternative embodiment, the distance between the plate 9 and the printed circuit 21 is fixed by spacers or fixing studs (not shown).

 In a second alternative embodiment, the plate 61 can be crushed during the introduction of a card, in particular embossed or thick, to ensure correct contact whatever the thickness of the card inserted in the reader. In fact, the stroke resulting from the crushing of the foam 61 is added to the stroke corresponding to the re-entry of the balls 5 into their cages 3.

 In the preferred embodiment, the balls 5 can rotate relative to the elastic return means 23, this rotation ensuring the cleaning of the contacts of the connector 1 according to the present invention during each introduction of a smart card 27 according to the arrow 29 in a card reader 31, illustrated in FIGS. 4, 7 and 8.

 The implementation of the omnidirectional connector according to the present invention avoids the appearance of grooves in the card, frequent with devices with sliding contacts of known type.

 Advantageously, the card reader 31 includes a limit switch 33, the closure of which ensures the electrical supply and the reading of the microcircuits 35 of the card 27. In the case of a card reader 31 as illustrated in the Figures 7 and 8 do not provide lateral guidance of the card, the limit switch 33 is advantageously located at the location of the corner of the card 27 after its insertion in the reader.

 Thus, the current is only established when it is certain that the card is correctly positioned in the reader. As a variant, the limit switch 33 can be replaced by a first limit switch 33.1 capable of being actuated by the longest side of the chip card 27 and a limit switch 33.2 arranged so as to be closed by the short side when it is correctly positioned in the reader, regardless of the direction of insertion of the card into the reader (Figure 7). The current is only established when the contacts 33.1 and 33.2 are simultaneously closed.

 It may be advantageous to provide a card reader 31 according to the present invention with means 37 ensuring the sealing of the reader relative to the card receiving slot 27. The means 37 comprise, for example, a deformable membrane hermetically sealed and disposed between the edge of the card 27 and the limit switch 33. It is possible to use an elastomer, plastic, textile membrane, in particular nonwoven.

 The limit switch 33 is actuated by the card 27 through the flexible membrane 37.

 Thus, sprinkling, or worse, accidental immersion of the reader, in the absence of a card 27, that is to say when the limit switch 33 is open and the contacts of the connector 1 are isolated from the the power supply does not cause damage to the reader, which can be reused after the contacts of connector 1 according to the present invention have been dried.

 The device according to the invention may further comprise sealing means of the flexible membrane 37 type and / or flap, sealing lip or element of non-wettable material at the level of the insertion slot, so as to limit the introduction of water and / or dust into the reader according to the invention.

 In FIG. 5, one can see an alternative embodiment of the connector according to the present invention comprises two balls 5 arranged opposite one another in a cage 3, pushed back from one another by a spring 23. Such a connector has improved reliability but a higher cost price and greater thickness.

 It is understood that the present invention is not limited to the implementation of spheres. Other solid conductive parts can be used, for example pins 5 ′ as illustrated in FIG. 6.

Advantageously, the pins 5 'are terminated by a spherical cap to avoid damaging the contacts, in particular of a smart card.

 Likewise, the spheres can be replaced by solid or tubular rollers for applications in which the direction of insertion of the card is known in advance, the axis of the rollers being perpendicular to the direction of insertion. It may prove advantageous to use rollers whose longitudinal ends are rounded and form, for example, hemispherical caps.

 The use of a self-cleaning omni-directional connector makes it possible to produce particularly compact card readers 31, an example of which is illustrated in FIGS. 7 and 8.

 Indeed, such a connector makes it possible to reduce on the one hand the thickness of the card reader and, on the other hand, its length insofar as it makes it possible to establish a safe and reliable contact without lateral guiding of the card.

 Thus, the reader can extend only above the corner of the smart card 27 to be inserted and no longer above its entire width.

 The reader 31 according to the present invention comprises means 39 for displaying information, preferably with liquid crystal, as well as means for interrogating the card known per se. The small size of the card reader allows it to be incorporated into a common object such as a key ring, lighter, belt buckle or the like. It can preferably be incorporated into electrical or electronic devices with which it shares the power supply, the information processing means, the input / output means and / or the display means.

 In FIG. 9, one can see a wristwatch according to the present invention comprising a built-in smart card reader.

 The watch battery advantageously provides the power supply to the smart card reader, the display means being switched into means for displaying information read from the card when the card is inserted into the slot or by pressing on a control button 41.

 The display means 39 of the watch are advantageously of the liquid crystal type. However, other types of display, such as for example a needle display, do not depart from the scope of the present invention.

 Likewise, a compact card reader according to the present invention can be incorporated into a cellular telephone, a toy, an electronic diary or the like.

 It can also advantageously be incorporated into a small authentication or certification calculator (called Token in English terminology) ensuring the calculation of security keys, for example during remote transactions: payment of a purchase, passage of a stock market order or, advantageously, downloading of “electronic” money into a smart card of the electronic purse type.

 The connector 1 according to the invention can be implemented for the connection of permanent memory module, writable (flash EEPROM or the like) or not (ROM read-only memory) in devices such as laptop, electronic agenda, digital camera or the like .

 The connector 1 according to the invention can also be used to write to the memory or memories of the chip.

 The connector according to the present invention can be associated with a landing connection mechanism, that is to say a mechanism for approaching until the establishment of the electrical contact between the connector according to the invention and the contacts of a card. . Such a device can be implemented, in particular in ATMs, bank terminals or the like.

 The present invention is particularly applicable to telecommunications and the electronics industry.

 The present invention applies mainly to the reading of smart cards, in particular of the electronic purse type, mono or multifunction, open or closed (with confidential code), and also of the loyalty card type.

Claims (12)

 1. Connector, in particular for a smart card (27), comprising at least one electrical contact, characterized in that said contact comprises a rigid solid conductive part (5.5 ′) retained in an insulating cage (3) provided with a first opening (15) leaving a portion of the solid conductive part (5.5 ′) protruding so as to establish an electrical contact, as well as a second opening for establishing electrical contacts (57) with a conductor (65) d 'a support (21) of the connector or with a conductor (23, 51, 59) electrically connected to a conductor of the support (21) of the connector.  2. Connector according to claim 1 characterized in that the solid rigid parts (5) have a spherical or substantially spherical shape.  3. Connector according to any one of the preceding claims, characterized in that said contact comprises an elastic return element (23, 59, 61) applying the rigid, solid, conductive part (5.5 ′) on a periphery of the first opening (15) of the cage (3) so that part of this rigid conductive solid piece (5.5 ′) protrudes from the cage (3).  4. Connector according to any one of the preceding claims, characterized in that the return element is a helical spring made of conductive material.  5. Connector according to any one of the preceding claims, characterized in that it comprises a plurality of electrical contacts and in that it comprises two insulating plates (9.1, 9.2) in which cavities (7) are arranged arranged in screws opposite.  6. Connector according to claim 5 characterized in that the cavities (7) formed in the plates (9.1, 9.2) have a frustoconical shape and in that the cavities (7) of the same cage (3) are aligned in a common axis (11) and are joined by their flared base (13).  7. Connector according to claim 5, characterized in that each cage (3) has a cylindrical middle part (3.1) extended on each of its ends by a truncated cone tapering towards the visible faces of the plates (9.1, 9.2 ).  8. Connector according to claim 1, 2 or 3, characterized in that it comprises a strip, conductive, elastic (51) applying the rigid solid conductive part (5.5 ') on the periphery of the first opening (15) and in that said strip is fixed to an insulating plate in which the cage (3) is formed.  9. Connector according to claim 8, characterized in that the strip 51 has an opening for passage of a fixing stud (53) on a plate (9) having a plurality of cages (3).  10. Smart card reader, characterized in that it comprises a connector according to any one of the preceding claims.  11. Smart card reader according to claim 10, characterized in that it comprises a limit switch (33) disposed at the location of the corner of the smart card (27) after its insertion into the reader.  12. Electronic device comprising an electrical supply and display means (39), characterized in that it comprises a smart card reader according to claim 10 or 11, in that the supply of the electrical device ensures supplying the chip card reader (27) and in that the display means (39) ensure the display of the reading result of the chip card (27).