Interface for controlling a function of a motor vehicle

Abstract

The invention relates to a control interface (1) comprising: - a capacitive measuring device (10); - a rotating member (20) mounted for rotation relative to the capacitive measuring device about an axis of rotation (A1) and comprising a body (21) extending along the axis of rotation and at least one extension (22) extending from the body transversely to the axis of rotation, the extension being orientable by rotation of the rotating member, the extension being at least partially electrically conductive, the extension extending at a distance from the capacitive measuring device; - at least one electrode (30) disposed on the periphery of the rotating member and having at least one surface (31, 32) opposite the extension when the extension is oriented towards the electrode; the capacitive measuring device being configured to detect a coupling capacitance between the extension and the surface of the electrode. Figure for the abstract: Fig. 2.

Description

Title of the invention: Interface for controlling a function of a motor vehicle Technical field

[0001] The present invention relates generally to the technical field of control interfaces.

[0002] It relates more particularly to an interface comprising a rotary member mounted in rotation relative to a capacitive measuring device.

[0003] The invention finds a particularly advantageous application in the production of interfaces for vehicle dashboards. Technological background

[0004] In the automotive field, the control of electrical components, such as the air conditioning or navigation system, is sometimes carried out by means of a mechanical rotary button, i.e. a wheel.

[0005] A control interface is known comprising a rotating member mounted on a capacitive measuring device which is also tactile, for example a slab or a tactile surface. The capacitive measuring device thus allows, on the one hand, the tactile input of information and, on the other hand, the detection of an angular position of the rotating member. For this, the rotating member conventionally comprises a cylindrical body and an extension forming a tongue and capable of adopting several distinct angular positions. The rotating member is electrically conductive, which allows the connection between the user's hand and the capacitive receivers of the capacitive measuring device.

[0006] In order to ensure correct detection of the angular position of the rotating member, mechanical contact is established between the extension and the capacitive measuring device. The extension thus has an electrically conductive flat lower surface extending against the capacitive measuring device and ensuring the connection with the user's hand.

[0007] This mechanical contact, however, causes wear of the lower surface by friction on the capacitive measuring device.

[0008] Furthermore, this mechanical contact is highly dependent on the mechanical tolerances of the assembled parts so that the axis of rotation of the rotating member is in practice not perpendicular to the capacitive measuring device. This can lead on the one hand to a loss of adhesion, which degrades the detection of the angular position, and on the other hand to a stress of the lower surface on the capacitive measuring device, which further increases mechanical wear. Summary of the invention

[0009] In this context, the present invention provides a control interface comprising: - a capacitive measuring device; - a rotary member mounted in rotation relative to the capacitive measuring device around an axis of rotation and comprising a body extending along the axis of rotation and at least one extension extending, from the body, transversely to the axis of rotation, the extension being orientable by rotation of the rotary member, the extension being at least partially electrically conductive, the extension extending at a distance from the capacitive measuring device; - at least one electrode arranged on the periphery of the rotating member and having at least one surface facing the extension when the extension is oriented towards the electrode; the capacitive measuring device being configured to detect a coupling capacitance between the extension and the surface of the electrode.

[0010] Thus, thanks to the invention, the extension is located at a distance from the capacitive measuring device, which prevents wear of the extension. To compensate for the distance of the extension, the interface comprises an electrode intended to interact capacitively with the extension. A coupling capacitance is created between the extension and the surface of the electrode, which varies depending on the orientation of the extension. The capacitive measuring device can then detect this coupling capacitance for the orientation of the extension.

[0011] Advantageously and optionally, the extension has a lower surface and an upper surface opposite the lower surface and electrically connected to the lower surface, and the electrode has a high surface and a low surface electrically connected to the high surface, the high surface facing the upper surface when the extension is oriented towards the electrode and the low surface facing the lower surface when the extension is oriented towards the electrode.

[0012] Thus, the coupling capacitance between the extension and the electrode results from a combination of a first coupling capacitance between the top surface and the upper surface and a second coupling capacitance between the bottom surface and the lower surface. Remarkably, the first coupling capacitance and the second coupling capacitance vary in opposite directions when the extension is shifted towards one or the other of the surfaces of the electrode.

[0013] Consequently, the coupling capacitance between the extension and the electrode is little affected by an inclination of the rotation axis relative to its design position. The detection of the orientation of the extension by the capacitive measuring device is then particularly robust with respect to the mechanical tolerances of the assembled parts.

[0014] Other advantageous and non-limiting characteristics of the interface according to the invention, taken individually or in all technically possible combinations, are the following: - the extension includes an electrically conductive coating also partially covering the body; - the electrode is attached to the capacitive measuring device; - the extension forms a long, linear branch extending perpendicular to the axis of rotation; - the electrode is interposed between the capacitive measuring device and the extension when the extension is oriented towards the electrode; - the electrode forms a hollow relief of a shape complementary to the shape of the extension; - the lower surface is parallel to the upper surface; - the upper surface is parallel to the upper surface and the lower surface is parallel to the lower surface; - a distance between the upper surface and the upper surface and a distance between the lower surface and the lower surface are between 0.1 and 1 mm.

[0015] Of course, the various features, variants and embodiments of the invention may be combined with each other in various combinations to the extent that they are not incompatible or mutually exclusive. Description of the invention

[0016] The description which follows with reference to the appended drawings, given as non-limiting examples, will make it clear what the invention consists of and how it can be implemented.

[0017] In the attached drawings:

[0018] [Fig-1] is a schematic top view of an interface according to the invention;

[0019] [Fig.2] is a schematic sectional view of the interface of [Fig.l] along plane AA

[0020] [Fig.3] is a schematic sectional view of the interface of [Fig.2] in which a rotating organ is inclined.

[0021] An interface 1 according to the invention is shown in [Fig.l]. For example, the interface 1 is mounted on the dashboard of a motor vehicle. The interface 1 here makes it possible to control a function of a motor vehicle such as the air conditioning, the navigation system, the position of the rearview mirrors or even the movement of the seats. Alternatively, the interface could make it possible to control other systems such as a thermostat in a home or even a Hi-Fi system. Generally speaking, the interface allows the control of an electrical system.

[0022] As shown in [Fig.l], the interface 1 comprises a measuring device ca- capacitive 10, a rotary member 20 mounted in rotation relative to the capacitive slab 10 and three electrodes 30 arranged on the periphery of the rotary member 20. The capacitive measuring device 10 is here a capacitive slab 10.

[0023] The electrodes 30 are more specifically distributed at a constant angular pitch, here 120 degrees, around the rotary member 20. The electrodes 30 here are arranged in a circle centered on the rotary member 20. The electrodes 30 are here fixed directly to the capacitive slab 10, for example by gluing. Alternatively, the electrodes can be fixed indirectly to the capacitive slab, for example by means of a structural element mechanically connecting the capacitive slab and the electrode.

[0024] As shown in [Fig.l], the electrodes are separated by covers 40, each cover 40 being in contact with two electrodes 30. The assembly consisting of the electrodes 30 and the covers 40 then forms an annular structure around the rotary member 20, which makes it possible to hide it and protect it, for example from shocks or dust. The covers 40 are for example made of plastic material.

[0025] Only one of the electrodes 30, called “the electrode” 30, is described below.

[0026] The capacitive slab 10 comprises a detection layer 11 and a front plate 12 arranged on the detection layer 11 as shown in [Fig.2]. The capacitive slab 10 is here planar.

[0027] The detection layer 11 is in particular designed to detect a variation in capacitance at an external surface 13 of the front plate 12. The external surface 13 is oriented towards the passenger compartment of the vehicle so that it can be touched by a user, for example by the driver. The detection layer 11 can detect the contact of a finger of the user. The capacitive panel 10 is thus tactile.

[0028] The detection layer 11 is more particularly adapted to determine the position of the finger on the external surface 13. The detection layer 11 comprises for example an antenna network meshing an internal surface 14 of the front plate 12, the internal surface 14 being opposite the external surface 13. An electrical circuit then makes it possible, for example, to measure variations in mutual capacitance between nodes of the antenna network, i.e. between nodes of the mesh formed by the antennas. The electrical circuit can also make it possible to measure the individual capacitance of each node. The antennas are for example made of indium-tin oxide so as to be transparent.

[0029] The capacitive slab 10 is also preferably transparent so that it can be superimposed on a screen, such as a TFT / LCD or OLED screen, configured to display information relating to the manipulation of the interface 1. This screen (not shown in the figures) is for example positioned, or even glued, against the detection layer 11. The capacitive slab 10 then makes it possible to produce a touch screen. The front plate 12 is then for example made of glass or transparent plastic material. Alternatively, the capacitive panel could be opaque, the interface could then be connected to a remote screen such as a head-up display.

[0030] The rotary member 20 is mounted in rotation on the capacitive slab 10 about an axis of rotation Al. As shown in [Fig. 2], the axis of rotation Al extends here substantially orthogonally to the external surface 13, which is here planar. “Substantially” means that the axis of rotation Al may be slightly inclined, for example by less than 10 degrees, relative to a direction orthogonal to the external surface 13. Such an inclination is for example due to the mechanical manufacturing tolerances of the parts.

[0031] The configuration in which the rotation axis A1 is inclined relative to a direction orthogonal to the external surface 13, as shown in [Fig. 3], is hereinafter called the "inclined configuration" as opposed to the configuration in which the rotation axis A1 is orthogonal to the external surface 13, as shown in [Fig. 2], and which is hereinafter called the "nominal configuration". In [Fig. 3], the rotation axis A1 is inclined towards one of the covers 40 as shown diagrammatically by a curved arrow.

[0032] As illustrated in [Fig.2], the rotary member 20 is for example rotatably mounted on the front plate 12 by means of ball bearings 50.

[0033] As shown in Figures 1 and 2, the rotary member 20 comprises a body 21 and an extension 22 in contact with the body 21. The body 21 extends along the axis of rotation A1 in the sense that it rises here from the capacitive slab 10. In the example illustrated in Figures 1 and 2, the body 21 has a cylindrical shape and more particularly a cylindrical shape of revolution around the axis of rotation A1. The body has, for example, a height, along the axis of rotation, of between 5 mm and 45 mm and a width, perpendicular to the axis of rotation, of between 10 mm and 40 mm.

[0034] The extension 22 extends transversely to the axis of rotation A1, that is to say along a transverse axis A2 relative to the axis of rotation A1. The extension 22 extends from the body 21 and more specifically at the level of a lower part of the body 21 located near the capacitive slab 10. By way of example, the transverse axis A2 is here perpendicular to the axis of rotation A1. In the nominal configuration, the extension 22 therefore extends substantially parallel to the external surface 13 as visible in [Fig.2].

[0035] As shown in [Fig. 2], the extension 22 has a lower surface 25, oriented towards the capacitive slab 10, and an upper surface 26 opposite the lower surface 25, i.e. oriented opposite the capacitive slab 10. In the example illustrated in [Fig. 2], the lower surface 25 and the upper surface 26 are planar. They are also parallel to each other. Indeed, the lower surface 25 and the upper surface 26 are here both orthogonal to the axis of rotation AL

[0036] The extension 22 here forms a branch or a long, elongated tongue, the length of which along the transverse axis A2 is for example between 5 mm and 40 mm from the body 21. The extension 22 here has a rectangular section perpendicular to the transverse axis A2 whose sides are for example between 1 mm and 20 mm. As a variant, the extension could have a rounded shape, for example a half-sphere, or a triangular shape pointing away from the body. As a further variant, the extension could have a flared or widened end or a comb-shaped end.

[0037] In all cases, the extension 22 occupies, relative to the axis of rotation A1, a predetermined angular sector, for example between 10 degrees and 60 degrees around the axis of rotation A1. The extension 22 is thus orientable, relative to the capacitive slab 10, by rotation of the body 21 around the axis of rotation A1. The extension 22 thus makes it possible to characterize, i.e. to indicate, a particular angular position of the rotary member 20.

[0038] As [Fig. 2] clearly shows, the extension 22 extends at a distance from the capacitive slab 10 and in particular at a distance from the external surface 13, for example at a distance of between 1 mm and 20 mm from the latter. The extension 22 is therefore not in contact with the capacitive slab 10 but opposite the capacitive slab 10.

[0039] The extension 22 is at least partially electrically conductive. The extension 22 is for example at least partly metallic. The extension 22 comprises for example a portion made of copper or aluminum.

[0040] The extension 22 is thus designed to interact capacitively with the electrode 30. This means here that the extension 22 is designed to bring electrical charges opposite the electrode 30, when the extension 22 is oriented towards the electrode 30. The presence of the extension 22 opposite the electrode 30 generates a coupling capacitance between the extension and the electrode 30. The coupling capacitance is maximum when the extension 22 is oriented towards the electrode 30.

[0041] Generally speaking, the fact that the extension 22 is oriented towards the electrode 30 means that the extension 22 is located at a distance less than a predetermined distance from the electrode 30. In other words, this means that the smallest distance between the extension 22 and the electrode 30 is less than the predetermined distance. The predetermined distance is for example between 0.1 mm and 2 mm.

[0042] The detection layer 11 of the capacitive slab 10 is then configured to detect the coupling capacitance between the extension 22 and the electrode 30. In other words, the detection layer 11 is configured to detect a variation in the electric field of the electrode 30 induced by the extension 22. The passage of the extension 22 near the electrode 30 is thus detected, by the detection layer 11, by measuring a variation in the coupling capacitance. The detection layer 11 can also measure an absolute value of the coupling capacitance. The detection layer 11 is thus configured to determine the position of the extension 22 relative to the electrode 30, and therefore the orientation of the rotary member 20, which makes it possible to control the function of the vehicle.

[0043] The electrical charges brought by the extension 22 opposite the electrode 30 come in particular from the user's hand. For this, the extension 22 here comprises an internal part 23 and an electrically conductive coating 24 covering the internal part 23. The coating 24 also partly covers the body 21, in particular at the level of a gripping surface 27 of the body 21 which is intended to be in contact with the user's hand. The gripping surface 27 includes in particular here the circular upper base of the cylindrical body 21, as shown in [Fig.l]. The coating 24 can also cover the entire body 21. Alternatively, the rotary member does not comprise a coating but is made entirely of metal.

[0044] Here, the coating 24 at least partially forms the lower surface 25 and the upper surface 26 as shown in [Fig. 2]. The coating 24 also forms a peripheral surface 26 of the extension 22, the peripheral surface 26 connecting the lower surface 25 and the upper surface 26. Therefore, the lower surface 25 is electrically connected to the upper surface 26.

[0045] The coating 24 is for example a metal deposit, for example of copper or silver, deposited by direct laser structuring, a technique better known by the English acronym LDS for “laser direct structuring”, by physical vapor deposition or even by 3D printing on the body 21 and the internal part 23 made of plastic material. The coating 24 may also comprise a layer of electrically conductive varnish covering the metal deposit to protect it.

[0046] As shown in [Fig. 2], the electrode 30 forms a hollow relief adapted to the passage of the extension 22 during a rotation of the rotary member 20. Here, the electrode 30 is curved so as to partially surround the extension 22 when the latter is oriented towards the electrode 30. The hollow relief thus has a shape complementary to that of the extension 22. By way of example, the electrode 30 here has a profile in the shape of a lying U or C, in a plane containing the axis of rotation A1 (for example the plane of [Fig. 2]), the branches of which extend parallel to the external surface 13.

[0047] Here, when the extension 22 is oriented towards the electrode 30, the transverse axis A2 intersects the electrode 30. In [Fig.l], the extension 22 is partly represented in dotted lines seen through the electrode 30.

[0048] The electrode 30 more specifically comprises a high surface 31 and a low surface 32 opposite the high surface 31. During a rotation of the rotary member 20, the extension 22 passes between the high surface 31 and the low surface 32 and at a distance from these last. When the extension 22 is oriented towards the electrode 30, the upper surface 31 extends opposite, i.e. opposite the upper surface 26, and the lower surface 32 extends opposite the lower surface 25.

[0049] Since it partially surrounds the extension 22, the electrode 30 makes it possible to generate a high-value coupling capacitance. The term “surrounds” here means that the electrode 30 matches the shape of the extension 22 while being at a distance from it.

[0050] The upper surface 31 and the lower surface 32 are electrically connected, here because the electrode 30 is formed from a single metal piece. Alternatively, the upper surface and the lower surface may be formed by a metal deposit, for example on a plastic material support, and electrically connected to each other by this same metal deposit or by an electric wire.

[0051] In the nominal configuration, the extension 22 preferably extends equidistant from the upper surface 31 and the lower surface 32. The upper surface 31 extends, for example, at a distance of between 0.1 mm and 2 mm from the upper surface 26. Similarly, the lower surface 32 extends, for example, at a distance of between 0.1 mm and 2 mm from the upper surface 26. This reduces the risk of the extension 22 coming into contact with the electrode 30 in the inclined configuration. The distance between two surfaces is here defined as the smallest segment connecting these two surfaces.

[0052] This particular configuration of the electrode 30 surrounding the extension 22 generates, when the extension 22 is oriented towards the electrode 30, a first coupling capacitance between the upper surface 31 and the upper surface 26 and a second coupling capacitance between the lower surface 32 and the lower surface 25. The coupling capacitance between the extension 22 and the electrode 30, called “overall coupling capacitance”, is then a combination of the first coupling capacitance and the second coupling capacitance. The coupling capacitance is for example equal to the sum of the first coupling capacitance and the second coupling capacitance.

[0053] Thus, remarkably, in the inclined configuration, when the extension 22 is brought closer to the upper surface 31 (as shown in [Fig. 3]) or to the lower surface 32, the first coupling capacitance and the second coupling capacitance vary in opposite directions. The overall coupling capacitance is thus little affected by this offset of the extension 22 relative to the nominal configuration. This notably limits the risk of false detections by the detection layer 11.

[0054] Preferably, the upper surface 31 is parallel to the upper surface 26 and the lower surface 32 is parallel to the lower surface 25. The upper surface 31 and the lower surface 32 are therefore preferably parallel to the external surface 13. The compensation of the overall coupling capacitance in the inclined configuration is particularly effective. Indeed, a move closer to the upper surface 31 is compensated by a separation of the same amplitude between the extension 22 and the surface bass 32, and vice versa.

[0055] Here, in the nominal configuration, the upper surface 31 and the lower surface 32 are parallel to the movement of the extension 22 when the rotary member 20 rotates around the axis of rotation A1.

[0056] The present invention is in no way limited to the embodiments described and shown, but those skilled in the art will be able to provide any variant in accordance with the invention.

[0057] For example, the interface may comprise a varied number of electrodes. It may for example comprise a single electrode, used for example to increment a counter when the extension passes, two electrodes or even more than three electrodes.

[0058] Similarly, the rotatable member may comprise more than one extension, for example two, three or four extensions. The extensions extend for example in a star pattern from the body. In combination with several electrodes, the plurality of extensions makes the position detection more robust and more accurate, for example by detecting coupling capacitance patterns of the electrodes.

[0059] The capacitive slab may have a curved shape, for example concave or convex. The axis of rotation of the rotary member is then, for example, arranged, in nominal configuration, orthogonally to a direction tangential to the external surface of the front plate. In this case, the extension may also be curved in a similar manner to the capacitive slab.

[0060] The shape of the electrode can also vary. The electrode may not even form a hollow relief but simply have a surface which is opposite the lower surface of the extension when the extension is oriented towards the electrode. Such an electrode is for example made up of a flat metal layer arranged on the front plate and interposed between the capacitive slab and the lower surface when the extension is oriented towards the electrode. The electrode can also be made up of a metal wall rising from the external surface and designed to interact capacitively with the peripheral surface of the extension. Such electrodes also generate a coupling capacitance with the extension, which allows the detection of the angular position of the rotary member.

Claims

Claims

1. Control interface (1) comprising: - a capacitive measuring device (10); - a rotary member (20) mounted in rotation relative to the capacitive measuring device (10) about an axis of rotation (Al) and comprising a body (21) extending along the axis of rotation (Al) and at least one extension (22) extending, from the body (21), transversely to the axis of rotation (Al), the extension (22) being orientable by rotation of the rotary member (20), the extension (22) being at least partially electrically conductive, the extension (22) extending at a distance from the capacitive measuring device (10); - at least one electrode (30) arranged on the periphery of the rotary member (20) and having at least one surface (31, 32) facing the extension (22) when the extension (22) is oriented towards the electrode (30);the capacitive measuring device (10) being configured to detect a coupling capacitance between the extension (22) and the surface (31, 32) of the electrode (30), characterized in that the capacitive measuring device is a capacitive slab (10) on which the rotary member (20) is mounted and in that the electrode (30) forms a hollow relief of a shape complementary to the shape of the extension (22).;

2. Interface (1) according to claim 1, in which the extension (22) comprises an electrically conductive coating (26) also partially covering the body (21).

3. Interface (1) according to claim 1 or 2, wherein the electrode (30) is attached to the capacitive measuring device (10).

4. Interface (1) according to one of claims 1 to 3, in which the extension (22) forms an elongated branch extending perpendicular to the axis of rotation (Al).

5. Interface (1) according to one of claims 1 to 4, in which the electrode (30) is interposed between the capacitive measuring device (10) and the extension (22) when the extension (22) is oriented towards the electrode (30).

6. Interface (1) according to one of claims 1 to 5, in which the extension (22) has a lower surface (25) and an upper surface (26) opposite and electrically connected to the lower surface (25), and in which the electrode (30) has a high surface

7.

8.

9. (31) and a lower surface (32) electrically connected to the upper surface (31), the upper surface (31) facing the upper surface (26) when the extension (22) is oriented towards the electrode (30) and the lower surface (32) facing the lower surface (25) when the extension (22) is oriented towards the electrode (30). Interface (1) according to claim 6, wherein the lower surface (25) is parallel to the upper surface (26). Interface (1) according to claim 6 or 7, wherein the upper surface (31) is parallel to the upper surface (26) and wherein the lower surface (32) is parallel to the lower surface (25). Interface (1) according to one of claims 6 to 8, wherein a distance between the high surface (31) and the upper surface (26) and a distance between the low surface (32) and the lower surface (25) are between 0.1 and 2 mm.

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