FR3084953A1 - PAYMENT TERMINAL WITH MAGNETIC CARD READER - Google Patents

Abstract

The present invention relates to an electronic payment terminal (1) comprising a magnetic card reader comprising a groove (12) in which is intended to slide a magnetic memory card (2), said groove (12) extending along one of the side faces (1012) of said payment terminal (1) connecting an upper face of the terminal to a lower face of the terminal. According to the invention, said groove (12) is shaped to modify the sliding path of said magnetic memory card (2) after processing thereof by said payment terminal (1) so as to evacuate the latter on the side of said payment terminal (1).

Description

Payment terminal with magnetic card reader

1. Field of the invention

The invention relates to the field of electronic payment terminals.

The invention relates more particularly to the field of electronic payment terminals comprising a card reader provided with a magnetic strip, called a magnetic reader.

The present invention applies in particular, but not exclusively, to mobile payment terminals.

2. Prior Art

It is known, and recalled here in a simplified manner, that an electronic payment terminal is a device which makes it possible to make purchases using a means of payment.

Current terminals are often called multimodal terminals because they accept several types of payment means, namely memory cards with contact reading or contactless reading.

Among known memory cards, there are at least two types which are the smart memory card, or smart card, which is commonly found in Europe, and the magnetic memory card, which is commonly found. in the USA. It should also be noted that in Europe, there is also a significant proportion of multimodal cards which include an electronic chip, placed on the front face of the memory card, as well as a magnetic strip, generally placed on the back of the card. card, according to ISO 7811 standard.

A payment terminal conventionally comprises a rigid box (for example of injected plastic) containing at least one electronic card to which various peripheral components ensuring the operation of the terminal are connected, namely an input keyboard, a display screen , a smart card reader, and a magnetic card reader, or magnetic cards.

More specifically, the magnetic card reader is configured to read the information contained on the magnetic strip or track of the magnetic card.

To do this, the magnetic reader of the terminal includes a slot or a groove open at its ends in which a user can scroll a magnetic card. A magnetic reading head is flush with a wall of the groove and allows the reading of data stored on the magnetic strip of the magnetic card when the magnetic card is scrolled in the groove.

In practice, the user inserts a magnetic card in the insertion groove and imparts a translational movement, that is to say a sliding movement, on the card so that the magnetic track of the card moves gradually. in front of the magnetic reading head of the payment terminal.

Payment terminals are known, the slot for inserting the magnetic card of which is located above the screen.

However, for the scrolling of the magnetic card in the groove to be carried out by the most natural possible movement for a user, it is generally preferable for the groove to extend along a lateral edge of the terminal, perpendicular to a plane. reference formed by the input keyboard and / or the display screen of the terminal, that is to say generally along a vertical plane. Such a magnetic reader is said to have a vertical and lateral slit.

However, when using such terminals, the sliding of the magnetic memory card in the groove can be problematic.

In fact, the width of the terminal being reduced, the groove extends close to the input keyboard. The presence of a code cache to mask the entry of a confidential code on the input keyboard can then hinder the handling of the magnetic card by a user. When the user scrolls the magnetic card in the groove, the user's thumb tends to abut against the walls of the code cover.

Furthermore, the groove being vertical and open upwards, the user must, during the sliding movement of the magnetic card in the groove, push the magnetic card downwards, which is not intuitive for all users.

This can make the scrolling of the magnetic card irregular with respect to the magnetic reading head, which is undesirable (the transaction may fail for these reasons).

One known solution for overcoming such drawbacks consists in placing the insertion groove on a lateral edge of the terminal so that the groove is parallel to the reference plane formed by the input keyboard and / or the screen d terminal display.

However, the inside of the groove being outside the user's visual field in a position of use of the terminal, a fraudulent reading head of the magnetic tape placed inside the groove by an malicious person is difficult. detectable.

Furthermore, when using such a payment terminal, it has been noticed that the user's hand and / or the magnetic card tends to strike the elements located near the payment terminal. For example, when the card slides, the user's hand tends to strike the support on which the terminal rests. Such shocks can cause the reader to read the magnetic tape, and therefore the transaction, forcing the user to iron the magnetic card in the groove of the reader.

In addition, such shocks can be considered unpleasant for a user who may possibly become reluctant, or even resistant, to the subsequent use of such a payment terminal.

3. Summary of the invention

The present disclosure makes it possible to at least partially resolve certain problems posed by these terminals of the prior art.

It is thus proposed an electronic payment terminal comprising a magnetic card reader comprising a groove in which is intended to slide a magnetic memory card, said groove extending along one of the side faces of said payment terminal connecting a upper face of the terminal to a lower face of the terminal, said groove being shaped to modify the sliding trajectory of said magnetic memory card after processing thereof by said payment terminal so as to evacuate the latter on the side of said terminal payment.

The magnetic reading groove or slot extends on one of the sides of the payment device and allows the reading of the payment card with magnetic stripe, by a translational movement of the latter over part of the length of the device. payment, then its withdrawal on one side of the payment terminal.

This groove has a particular shape for the passage of the magnetic card so that, when scrolling in the groove of the magnetic card manipulated by a user, the card is directed towards the side of the payment device when the card passes near the cache code (when the terminal is equipped with it) or approaches the support on which the terminal is based.

In this way, the user's hand cannot strike the support on which the terminal rests and / or the code cache.

This makes it possible to move away from the code cache and / or from the support on which the terminal rests the lower edge of the magnetic card held by the user and makes it possible to prevent the user's fingers from striking the code cache (and therefore keep a large size of the code cover) and / or the support when it slides the card into the groove.

The solution of the invention improves the ergonomics of the terminal and therefore the user experience of it, and guarantees the protection of confidential data contained in the track of the magnetic memory card. .

Such a solution is easy and inexpensive to implement, in particular in mobile payment terminals of compact size.

It can be implemented in mobile terminals or not (terminals on a base).

According to a particular embodiment, the groove is delimited by two opposite guide walls connected by a bottom wall, the groove comprising a first portion in which the bottom wall is straight and substantially parallel to the plane of the lateral face of the payment terminal, the first portion being extended by a second portion in which the bottom wall is curved, forming a discharge ramp for the magnetic memory card.

According to this particular embodiment, the ramp located in the reading groove of the magnetic card forms a guide forcing the evacuation of the card on the side of the terminal and not at the lower end of the groove as is the case. with the payment terminals of the prior art.

According to a particular embodiment, the groove opens at a first end situated on the side of the first portion of the groove, the second end of the groove being closed by the curved bottom wall forming a discharge ramp, the scrolling of the card in the groove being intended to be produced from the first end to the second end.

Such a curved shape of the bottom wall at the end of the sliding of the card makes it possible to improve the ergonomics of the payment terminal and to initiate slowly, smoothly, the change of sliding trajectory of the magnetic memory card .

According to a particular embodiment, the curved bottom wall of the second portion of the groove comprises:

a first rounded part extending the rectilinear bottom wall of the first portion of the groove,

- a second inclined part extending the first rounded part to the side face of the payment terminal.

According to a particular embodiment, the angle of inclination between the second inclined part of the curved bottom wall and the straight bottom wall of the first portion of the groove is between 20 ° and 30 °.

An inclination angle included in such an interval makes it possible, when the user proceeds to slide the magnetic memory card in the reader, to quickly modify the sliding trajectory of the card, with a view to its ejection, without compromising comfort of the user, that is to say without causing joint shocks for example.

According to a particular embodiment, the first rounded part of the curved bottom wall is an arc of a circle having a radius between 40mm and 50mm.

According to a particular embodiment, a magnetic read head of a magnetic stripe of the magnetic memory card is arranged at the level of the first portion of the groove.

According to a particular embodiment, the distance between the magnetic read head and the initiation of the first rounded part of the curved bottom wall is between 850mm and 1000mm.

According to this particular embodiment, the fact of spacing the magnetic reading head of the evacuation ramp by a value included in this interval makes it possible to initiate evacuation of the card out of the groove quickly after reading of the card by the magnetic head, and quickly tilt the magnetic strip of the card once it has been read by the magnetic head.

As a result, reading the magnetic stripe by a fraudulent magnetic head which would be placed between the magnetic head of the terminal and the discharge ramp is made difficult.

Thus, the payment terminal provides simple and inexpensive protection of the data contained in the magnetic memory card.

According to a particular embodiment, the surfaces of the walls of the second portion of the groove are made of metallic material.

According to this particular embodiment, the mechanical strength of the discharge ramp is improved so as to withstand the mechanical stresses exerted by the edge of the magnetic memory card when it slides in the groove of the payment terminal.

Thus, the life cycle of the payment terminal is improved.

4. Figures

Other characteristics and advantages will appear more clearly on reading the following description of a particular embodiment of the disclosure, given by way of simple illustrative and nonlimiting example, and of the appended drawings, among which:

Figure 1 is a perspective view of a payment terminal according to the invention;

Figure 2 is a schematic side view of the payment terminal of Figure 1;

Figure 3 is a longitudinal sectional view of part of the payment terminal of Figure 1;

Figure 4 is a perspective view and partially transparent of the payment terminal of Figure 1; and FIGS. 5A and 5B illustrate the use of the payment terminal of FIG. 1 with a magnetic memory card.

5. Detailed description

For the sake of clarity, the same elements have been designated by the same references in the different figures. Only the elements necessary for understanding the present invention will be described.

5.1 General principle

The general principle of the present invention consists in providing in a groove for reading a magnetic card of a payment terminal, a ramp making it possible to evacuate the magnetic memory card on the side of the terminal after reading it by a read head located in the groove.

Such an evacuation ramp makes it possible to modify the sliding trajectory of the magnetic memory card after it has been processed by the payment terminal and to guide the movement of the user's hand so as to laterally extract the card to magnetic memory, so as to minimize the risks that the user's hand, or the lower edge of the magnetic memory card, collide with the element or elements (support in particular) located near the payment terminal.

5.2 Description of an embodiment

FIG. 1 represents an exemplary embodiment of an electronic payment terminal 1 according to the invention.

The payment terminal 1 comprises a rigid housing 10 made of injected plastic, for example. The housing 10 comprises a front face visible in FIG. 1, a rear face oriented in FIG. 1 towards a horizontal plane H corresponding to a theoretical flat surface on which the payment terminal 1 is placed, and two opposite lateral faces connecting the face front to back.

According to the present exemplary embodiment, the payment terminal 1 is a portable terminal which can be held in the hand by a user.

The housing 10 has a general L shape and includes a first part 101, substantially parallelepiped, extending in a first plane and extended by a second part 102, substantially parallelepiped, extending in a second plane distinct from the first plane.

The first part 101 of the housing 10 is inclined relative to the horizontal plane H and the second part 102 of the housing 10 extends from the upper end 1010 of this first part 101 towards the horizontal plane H.

In other words, the second part 102 of the housing 10 is inclined relative to the first part 101 of the housing 10 so that the lower ends 1011, 1021 of the first and second parts 101, 102 respectively constitute zones of support and are adapted to rest on a horizontal support (defining the plane H).

Thus, when the payment terminal 1 rests on the horizontal support, the first part 101 of the housing 10 is inclined relative to the horizontal plane H by an angle of inclination a equal to 15 °, as illustrated in FIG. 2 .

The payment terminal 1 comprises in the example illustrated an interface screen 11 configured to display and / or enter data relating to a payment transaction for example.

In this embodiment, the interface screen 11 extends over the upper face of the first part 101 of the housing 10 and defines a viewing plane P inclined relative to the horizontal plane H. The inclination between the plane of display P and the horizontal plane H is equal to the angle of inclination a (i.e. 15 ° in this embodiment).

Such an inclination of the viewing plane P makes it possible to facilitate the reading of the information displayed on the interface screen 11 by the user and to prevent the viewing of the information displayed by malicious persons. In other words, such an inclination improves the ergonomics of the terminal while improving the security of confidential information intended for the user.

The electronic payment terminal 1 comprises a smart card reader with contact reading and is also suitable for being able to read cards provided with magnetic tracks, or magnetic cards.

There is thus provided a magnetic card reader, having the form of a slot or groove 12 (also called swipe guide), into which a user can insert and scroll a magnetic card.

A magnetic read head disposed in the groove 12 makes it possible to read data stored on a magnetic strip of the user's card, when the card slides in the groove 12.

The groove 12 is formed on a lateral face 1012 of the payment terminal 1 and extends along the lateral face 1012 parallel to the display plane P.

Such an arrangement of the groove 12 makes it possible to improve the ergonomics of the payment terminal 1 by minimizing the risks of the user striking a code cover (not shown), for example located on the terminal or the support on which is installed the payment terminal 1.

The groove 12 comprises two guide walls 121 spaced apart and arranged opposite. The guide walls 121 extend parallel to the viewing plane P, and have large dimensions so as to guarantee the stability and the sliding continuity of the magnetic memory card in the groove 12.

The bottom wall 122 of the groove 12, connecting the guide walls 121, is a flat surface of small width, namely a width slightly greater than the thickness of the magnetic memory card (thickness which is itself normatively defined in one of the booklets of standard 7811). The bottom wall 122 of the groove 12 extends perpendicular to the viewing plane P.

In this embodiment, the groove 12 is formed on a lateral face 1012 or a side of the first part 101 of the payment terminal 1. The groove 12 opens at the upper end 1010 of the first part 101. As we will see it later, the other end of the groove 12 is blind.

Furthermore, the longitudinal axis X of the groove 12 is inclined relative to the horizontal plane H. The inclination between the groove 12 and the horizontal plane H is equal to the angle of inclination a (i.e. 15 ° in this mode of realization). Such an inclination allows the user to easily slide a magnetic memory card in the groove 12.

The magnetic read head 13, configured to read the data contained in a magnetic strip of the magnetic memory card (not shown in this figure) is located on one of the guide walls 121 of the groove 12, near the 'upper end thereof (that is to say near the upper end 1010 of the first part 101.

Furthermore, the read head 13 is arranged so as to be parallel with the magnetic strip of the magnetic memory card when it slides in the groove 12, so as to be able to ensure correct reading of the magnetic strip.

According to the proposed technique, the groove 12 is open at its upper end thus allowing the insertion of the card into the groove 12, and is blind at its lower end in that it comprises at its lower end a discharge ramp 14 configured to modify the sliding trajectory of the magnetic memory card after reading of the card's magnetic strip by the read head 13. The discharge ramp 14 is located downstream of the read head 13, at the end bottom of the groove 12, in the sliding direction of the magnetic memory card (from top to bottom in this case).

The discharge ramp 14 is shaped to deflect the card out of the groove 12 and extract the latter at the side face 1012.

The groove 12 comprises a first portion 12A in which the bottom wall 122 is straight and substantially parallel to the plane of the lateral face 1012 of the payment terminal 1, the first portion 12A being extended by a second portion 12B in which the bottom wall 122 is curved and is oriented towards the lateral face 1012.

The curved bottom wall 122 of the second portion 12B of the groove 12 comprises:

a first rounded portion extending the rectilinear bottom wall 122 of the first portion of the groove 12,

- a second straight and inclined part relative to the longitudinal axis X of the groove

12, extending the first rounded part to said side face 1012 of said payment terminal 1.

The discharge ramp 14 closes the lower end of the groove 12 and extends from the bottom 122 of the groove 12 to the side face 1012 of the payment terminal 1 in which the groove 12 is formed.

The discharge ramp 14, visible in FIGS. 3 and 4, makes it possible to gradually modify the sliding path of the magnetic memory card in the groove 12 towards the lateral face 1012 of the payment terminal 1.

Thus, the evacuation of the magnetic memory card is implemented before it reaches the lower end of the payment terminal 1 (which is not the case with payment terminals of the art prior). This minimizes the risk of the user's hand or the magnetic memory card hitting the horizontal support.

Furthermore, the evacuation ramp 14 makes it possible to evacuate the magnetic memory card simply and quickly while ensuring smooth sliding of the magnetic memory card.

Such a configuration therefore makes it possible to improve the ergonomics of the payment terminal.

In summary, the groove 12 successively comprises, from the first open upper end, called the inlet end, a first straight portion, a second curved portion followed by a third inclined portion opening onto a second outlet end, the read head. magnetic being disposed at the first portion, near the first inlet end.

The rounded portion 141 of the discharge ramp 14 is connected to the bottom 122 of the groove 12 and the straight inclined portion 142 of the discharge ramp 14 is connected to the side face 1012 of the first part 101 of the terminal housing 10 payment 1.

Having the rounded portion 141 of the discharge ramp 14 at the bottom 122 of the groove 12 makes it possible to slowly initiate the change in the sliding trajectory of the magnetic memory card from the first portion 12A of the groove 12 towards the side 1012 of the payment terminal 1.

In other words, the rounded portion 141 makes it possible to minimize the risks of jolts during the change of trajectory.

Such a configuration improves the ergonomics of the payment terminal 1.

It should be noted that the rounded portion 141 and the rectilinear portion 142 inclined to the discharge ramp 14 extend perpendicular to the viewing plane P, the width of the bottom wall 122 in these portions being slightly greater than the thickness of the magnetic memory card.

Advantageously, the discharge ramp 14 has little or no impact on the size of the payment terminal.

In the illustrated embodiment, the inclined rectilinear portion 142 of the discharge ramp 14 has an angle of inclination β of 23 ° relative to the longitudinal axis X of the groove 12. Such an angle makes it possible to quickly modify the sliding path of the magnetic memory card in the groove 12 without compromising the comfort of the user (without causing articular shocks for example), when the latter slides the magnetic memory card in the groove 12.

The rounded portion 141 of the discharge ramp 14 is an arc of a circle having a radius R of curvature equal to 47 mm.

Furthermore, the starting point 143 of the curved portion 141 of the discharge ramp 14 is distant from the magnetic read head 13 by a predetermined spacing value E.

In this embodiment, the spacing value E is 860 mm, that is to say slightly greater than the length of a magnetic memory card (length which is itself normatively defined in one of the specifications of the standard 7811).

Such a spacing value E makes it possible to initiate the change in the sliding trajectory of the magnetic memory card in the groove 12 as soon as the reading of the magnetic strip by the magnetic reading head 13 of the payment terminal 1 is completed. .

Thus, the sliding distance for the user is minimized.

In addition, the fact of ejecting the magnetic memory card directly after the reading of the magnetic strip makes it possible to reduce the time and the effort necessary to effect the sliding of the magnetic memory card in the groove 12.

Such a configuration therefore makes it possible to improve the ergonomics of the payment terminal.

Figures 5A and 5B illustrate different phases of the sliding of a magnetic memory card 2 in the groove 12 of a payment terminal 1 according to the proposed technique.

The user inserts the card into this groove 12 from the top and moves the card by sliding within it from the top down, the card coming to bear against the bottom wall 122 of the groove 12.

Generally, in order for the magnetic card 2 to be able to be read correctly by the payment terminal 1, it is necessary for the magnetic strip 20 of the card, visible in FIG. 5B, and the read head 13 magnetic disposed in the groove 12 are aligned along the longitudinal axis X of the groove 12, and this throughout the period during which the magnetic read head 13 reads the magnetic track 20 of the card.

Otherwise, that is to say if the magnetic strip 20 is inclined relative to the longitudinal axis X, the reading of the magnetic strip 20 may be interrupted, forcing the user to pass the card again. magnetic 2 in groove 12.

The configuration of the groove 12, previously described, makes it possible to ensure a correct reading of the magnetic track 20 of the card by the head of the magnetic reading 13, during a first phase of sliding along a straight line trajectory Tl parallel to the axis. longitudinal X.

When the magnetic strip 20 is read, the lower edge of the card furthest from the magnetic read head 13 is located near the point 143, as illustrated in FIG. 5A.

Then, when the magnetic card 2 engages along the discharge ramp 14, the sliding path T2 of the card is modified and is oriented towards the lateral face 1012 of the payment terminal 1, as illustrated in the Figure 5B. The magnetic card 2 thus gradually pivots until it leaves the groove 12.

Thus, as the magnetic card 2 progresses in the groove 12, the non-rectilinear shape of the bottom wall 122 causes the magnetic card 2 to tilt more and more, so that the lower edge of the magnetic card 2 is far from the code cover (if the terminal has one) or from the terminal support. The fingers of the user handling the card then do not come into contact with the code cache or the terminal support at the end of the scrolling of the magnetic card 2 in the groove 12.

In addition to improving the ergonomics of the payment terminal 1, the evacuation ramp 14 ensures protection of the data contained in the magnetic card 2.

In fact, as soon as the read head 13 finishes reading the magnetic track 20, the discharge ramp 14 inclines the magnetic track 20 enough to make it impossible, at least difficult, to read the magnetic track 20 by a head fraudulent reading device 13 ′ which would be placed between the reading head 13 of the terminal and the discharge ramp 14.

5.3. Other characteristics and embodiments

The payment terminal according to the invention further comprises at least one central processing unit, carried by at least one electronic card and connected to the various electronic components ensuring the operation of the terminal, such as the magnetic reading head, the screen 'interface, ...

In the embodiment described, the payment terminal is a mobile payment terminal comprising an “Android®” (registered trademark) operating system.

According to a particular implementation of the invention, all or part of the surface of the bottom wall 122 of the groove is made of a metallic material, such as steel or a steel alloy, or is covered with a metallic material, so as to be able to resist the mechanical stresses exerted by the edge of the magnetic card during the sliding and the change of trajectory of the latter in the groove 12.

Such a material minimizes wear and tear on the payment terminal.

In a particular embodiment, the inclined portion of the discharge ramp is made of a plastic material.

According to a particular implementation, the payment terminal comprises a contactless payment means disposed on the second part 102 of the housing 10.

This second part 102 of the housing 10 can carry a second interface screen and / or an input keyboard. Thus, when the first part 101 of the box is oriented towards a user, the second part 102 of the box 10 is oriented towards a merchant who can follow, through the second interface screen, the progress of the payment transaction.

Note that the angle of inclination between the first part 101 of the housing 10 and the horizontal plane H may be between 5 ° and 30 °.

The angle of inclination β the straight portion 142 inclined of the discharge ramp 14 and the longitudinal axis X of the groove 14 may be between 20 ° and 30 °.

The radius of the rounded portion 141 of the discharge ramp 14 may be between 40mm and 50mm.

The spacing value E between the starting point 143 of the curved portion 141 of the discharge ramp 14 and the magnetic read head 13 may be between 850mm and 1000mm.

In a variant of the embodiment described above, the discharge ramp only comprises a rounded portion connecting the bottom of the groove to the lateral face of the payment terminal.

Obviously, the proposed technique is not limited to the embodiments described above and provided only by way of example. It encompasses various modifications, alternatives and variants which a person skilled in the art may envisage within the framework of the present invention and in particular any combination of the various embodiments described above, which can be taken separately or in combination.

Claims (9)

1. Electronic payment terminal (1) comprising a magnetic card reader comprising a groove (12) in which a magnetic memory card (2) is intended to slide, said groove (12) extending along one lateral faces (1012) of said payment terminal (1) connecting an upper face of the terminal to a lower face of the terminal, said electronic payment terminal (1) being characterized in that said groove (12) is shaped to modify the trajectory sliding said magnetic memory card (2) after processing thereof by said payment terminal (1) so as to evacuate the latter on the side of said payment terminal (1). 2. electronic payment terminal (1) according to claim 1, characterized in that said groove (12) is delimited by two opposite guide walls connected by a bottom wall (122), said groove (12 ) comprising a first portion (12A) in which the bottom wall (122) is rectilinear and substantially parallel to the plane of said lateral face (1012) of said payment terminal (1), said first portion (12A) being extended by a second portion (12B) in which the bottom wall (122) is curved, forming a discharge ramp (14) of said magnetic memory card (2). 3. electronic payment terminal (1) according to claim 2, characterized in that the groove (12) opens at a first end located on the side of the first portion (12A) of said groove (12), the second end of said groove (12) being closed by the curved bottom wall (12) forming a discharge ramp (14), the movement of the card in the groove (12) being intended to be carried out from the first end to the second end . 4. Electronic payment terminal (1) according to claim 2 or 3, characterized in that said bottom wall (122) curve of the second portion (12B) of the groove (12) comprises: a first rounded portion (141) extending the straight bottom wall (122) of the first portion (12A) of the groove (12), - a second inclined part (142) extending the first rounded part (141) up to said lateral face (1012) of said payment terminal (1). 5. Electronic payment terminal (1) according to claim 4, characterized in that the angle of inclination (β) between the second inclined part (142) of the bottom wall (122) curved and the bottom wall ( 122) rectilinear of the first portion (12A) of the groove (12) is between 20 ° and 30 °. 6. electronic payment terminal (1) according to claim 4 or 5, characterized in that said first rounded portion (141) of the curved bottom wall (122) is an arc of a circle having a radius between 40mm and 50mm. 7. Electronic payment terminal (1) according to one of claims 2 to 6, characterized in that a magnetic read head (23) of a magnetic strip (20) of the magnetic memory card (2) is disposed at the first portion (12A) of said groove (12). 8. Electronic payment terminal (1) according to claim 7, characterized in that the distance E between the magnetic read head (23) and the initiation of said first rounded part (141) of the bottom wall (122) curve is between 850mm and 1000mm. 9. Electronic payment terminal (1) according to any one of claims 1 to 8, characterized in that the surfaces of the walls of the second portion (12B) of the groove (12) are made of metallic material.