EP3583697A1

EP3583697A1 - Motor vehicle door handle with transmission device and sensor device

Info

Publication number: EP3583697A1
Application number: EP18718137.5A
Authority: EP
Inventors: Berthold Sieg; Andreas Gornik
Original assignee: Huf Huelsbeck and Fuerst GmbH and Co KG
Current assignee: Huf Huelsbeck and Fuerst GmbH and Co KG
Priority date: 2017-06-08
Filing date: 2018-04-13
Publication date: 2019-12-25
Also published as: DE102017112688A1; JP2020525671A; WO2018224205A1

Abstract

The invention relates to a vehicle door handle having a capacitive sensor arrangement, wherein an antenna coil (2) having at least one coil winding is accommodated in a handle housing (1) and a sensor electrode (5) is accommodated in the handle housing at a distance from the antenna coil. The sensor electrode (5) and the antenna coil (2) overlap in the direction of the respective longest extent and are coupled to a control and evaluation circuit (6). The sensor electrode (5) and the antenna coil (2) have an electrically conductive screen (4) arranged between them that is couplable to a screen potential by means of the control and evaluation circuit. The control and evaluation circuit actuates the sensor electrode, the screen and the antenna coil such that the antenna coil is actuated with staggered timing in relation to the sensor electrode, and the screen is at least intermittently coupled to the screen potential when the sensor electrode is actuated.

Description

Motor vehicle door handle with transmitting device and sensor device

The invention relates to a motor vehicle door handle with a transmitting device and a sensor device. In particular, the invention relates to a vehicle door handle with a

capacitive sensor arrangement for detecting approaches to the vehicle door handle. The capacitive sensor arrangement is accommodated in a handle housing of the vehicle door handle. Also included in the handle housing is an antenna coil with

at least one coil winding. The antenna coil can

in particular as a transmitting coil for low-frequency signals

be formed (for example in the range of 125 kHz).

In the handle housing, the sensor electrode is accommodated at a distance from the antenna coil, so that the sensor electrode extends with its longest extension in the direction of the winding axis of the coil winding. The sensor electrode and the

Antenna coil are correspondingly substantially the same

Orientation taken along its longitudinal extent in the handle housing. The sensor electrode and the antenna coil are also aligned with each other so that they overlap in the direction of their longest extent at least partially, ie within the handle housing at least in sections

run side by side.

Both the sensor electrode and the antenna coil are coupled to a control and evaluation circuit.

Vehicle door handles of the type described are known in the art. For example, the document discloses

DE 10 2011 086 609 AI a corresponding door handle with an antenna unit and a sensor device.

Another door handle device is disclosed for example in the document DE 10 2005 035 935 AI. While in conventional door handles, the antenna coil and the sensor electrode in a handle housing in sufficient

Distance from each other could be arranged require

Reductions in the installation space with current door handles and

particularly space-saving arrangements, the arrangements of the antenna in close proximity to the sensor electrode.

The proper function of the sensor electrode can be influenced in such compact designs, so that the

Sensor electrode is not working properly.

The object of the invention is to provide a robust and less susceptible construction of a vehicle door handle with little space.

This object is achieved by a vehicle door handle having the features of claim 1.

According to the invention, between the sensor electrode and the antenna coil at least one electrically conductive

Shield arranged by the control and

Evaluation circuit with a shielding potential can be coupled.

In the arrangement of the antenna coil and the sensor electrode in close proximity, in particular an approach to a few millimeters (at least less than 10 mm) or a fraction of millimeters, a capacitive coupling between the sensor electrode and the antenna coil is formed, which impairs proper functioning of the sensor electrode , The inventive arrangement of a shield between the

Sensor electrode and the antenna coil causes on the one hand, a capacitive coupling between the antenna coil and the shield and on the other hand between the shield of the

Sensor electrode is established. The coupling of the shielding with a shielding potential allows a large extent

Cancellation of the negative influence on the function of

Sensor electrode. In particular, a resonant coupling of the antenna coil and the sensor electrode is suppressed by the shielding. Although by the shield and the Sensitivity of the sensor electrode influenced, the positive

However, the effect of suppression of the resonant coupling is greater so that the system operates more effectively overall.

The shield is suitable for developing its effect independently of the operating state of the antenna coil. The

In fact, the sensor electrode is in no way disturbed only during operation of the antenna coil; instead, the inductance of the antenna coil is capacitively coupled to the sensor electrode and influences the function of the sensor electrode even in the quiescent state of the antenna coil.

It may be provided within the scope of the invention that the antenna coil is controlled with a time delay to the sensor electrode, but it is essential that the shield at least in such a way with temporal overlap together with the

Sensor electrode is driven such that the shield is at least temporarily coupled to the Abschirmpotenzial when the sensor electrode is driven. In particular, the grip mass or vehicle mass can serve as shielding potential.

The operating times of the sensor electrode, the arranged between the antenna coil and the sensor electrode and acts with the

Abschirmpotenzial coupled electrically conductive shield as a decoupling element, which eliminates the direct capacitive coupling between the sensor electrode and antenna coil. Even if the sensor electrode is capacitively coupled to the shield, the effect on the

Sensor electrode, in particular due to the coupling of

Shielding with the screening potential, much lower than the unshielded coupling with the inductance of the

Antenna coil.

The shield may be formed as a metal foil, sheet metal as well as a more complex conductor structure. Likewise, the sensor electrode may be a single conductor surface or split

Conductor surface as well as also formed as a complex conductor structure. In a preferred embodiment of the invention, the sensor electrode and the shield are on a common

Printed circuit board applied, but at different levels of this circuit board. In particular, it may be provided to arrange the shield and the sensor electrode on opposite sides of a single printed circuit board, but it can also be used multilayer printed circuit boards.

The sensor electrode and / or the shield can be used as surface-mounted components on this printed circuit board

be upset.

However, it is particularly preferred, the sensor electrode and the shield each as a conductor directly on the

Form PCB.

Such a configuration of the sensor electrode and the

Shielding is easy to manufacture and already at

Provide printed circuit board production. In addition, in this way, more complex conductor geometries for both

Sensor electrode can be provided as well as for the shield. Finally, the orientation of the sensor electrode to the shield is also precisely fixed.

In a particularly preferred embodiment of the invention, the sensor electrode has branched conductive structures which extend on at least one plane of the printed circuit board.

The use of branched conductor structures on the one hand ensures that a larger surface area can be encompassed or encompassed by the sensor electrode, which due to the incomplete filling of this region with conductive material of the sensor electrode is simultaneously available for further components or, for example, openings in the printed circuit board. In this way, a compact design is further favored and material optimized to achieve the greatest possible sensitivity of the sensor electrode.

In a further development of the invention, the shield has branched conductor structures, which are based on at least one Extend level of the circuit board. The same applies in principle to the shielding as stated above for the sensor electrode. The branching of a guide structure ensures that the largest possible area of the electromagnetic

Influence of the shield is detected while at the same time the occupancy area is reduced by the conductor structure of the shield.

It is particularly preferred to form the forked conductor structures discussed above in a fork-shaped arrangement, wherein from a common conductor base

Plural of parallel tracks emanates. Such a fork-shaped design makes it possible to contact the conductor base, so the fork base, in a simple manner, with the branched conductor structures as forks of the

Extend ladder base and reach through a portion of the circuit board spaced.

Such a bifurcated structure represents in terms of easy contactability and spatial effect of

Electrode structure is an effective arrangement.

According to a preferred embodiment of the invention, the largest dimension of the sensor electrode is chosen to be between 80% and 120% of the maximum extent of the shield. Particularly effective is the shielding effect of the shield on the sensor electrode when the

Length extension is chosen approximately equal, especially if the sensor electrode does not protrude significantly beyond the shield in the edge regions. Nevertheless, it has been shown that, if necessary, a deviation in the longitudinal extent in the degree described still allows the shielding effect to be sufficient.

According to a particularly preferred embodiment of the

Motor vehicle door handle according to the invention is provided to form the sensor electrode and the shield in the direction parallel to the printed circuit board plane with congruent geometry. In this configuration, the sensor electrode with congruent geometry to the shield, but on different surfaces or levels of the circuit board

educated. This design is particularly simple in terms of their production. It is even possible, if necessary, the functions of the sensor electrode and the shield, depending on the arrangement of the

PCB to exchange, because the same geometry is present.

In a particularly preferred embodiment of the

Vehicle door handle are the sensor electrode and the shield in the direction parallel to the PCB level and with

formed different geometries, in such a way that in a projection perpendicular to the circuit board level of the sensor electrode occupied sensor electrode areas overlap with the shielding-free areas.

It has been found that the shielding effect on the sensor electrode can be optimized by the

Conductor structures of the sensor electrode on the one hand and the

Shielding electrode on the other hand on the PCB levels offset and arranged with different geometry that no congruence in one direction

perpendicular to the PCB level. For example, it can be provided that the sensor electrode, one, two or more conductor structures having parallel extension on a sensor plane, while the shield the

Aligns conductor structures such that the conductive regions are located in the interstices of the conductor structures of the sensor electrode, with quite overlaps between the

Ladder structures are possible. Whenever overlaps are mentioned here, it is meant to be partially congruent in a projection perpendicular to the board level. A

Contact between the conductors does not occur, since the conductor structures are arranged on different levels of the printed circuit board. In a preferred embodiment of the invention, the smallest distance between the shield and the antenna coil is chosen to be less than 8 mm, preferably less than 4 mm.

In such a compact arrangement between the shield and antenna coil, the reduction in the size of the

Vehicle door handles possible, thereby reducing weight, improving aerodynamics and expansion of the

Design possibilities brings with it. Such a small one

Expansion is only possible in which the invention

Shielding and coupling is realized with a shielding potential.

The invention will now be explained with reference to the accompanying drawings.

FIG. 1 shows schematically a device according to the invention

Vehicle door handle according to a first embodiment of the

Invention;

Figure 2 shows schematically the top and bottom of a circuit board of the first embodiment with sensor electrode and shield and coupled control and evaluation;

Figure 3 shows schematically a section through a

Printed circuit board with sensor electrode and shield according to the first embodiment.

FIG. 1 shows a vehicle door handle with a housing 1. In the housing 1, an antenna coil 2 having a coil winding wound around a ferrite core is shown. A circuit board 3 is disposed adjacent to the antenna coil 2. The distance of the antenna coil 2 from the printed circuit board 3 is less than 10 mm in this embodiment. On one of the antenna coil 2 side facing the circuit board 3, a shield 4 is arranged as a conductor on the circuit board 3. The printed circuit board 3 is made 1 mm thick in this embodiment. On a side facing away from the antenna coil 2 of the circuit board 3 is a sensor electrode 5 as

Conductor structure arranged on the circuit board 3. With a Control and evaluation device 6 are both the antenna coil

2 and the shield 4 and the sensor electrode. 5

coupled. Via the control and evaluation device 6, the antenna coil 2 can be driven to transmit low-frequency signals in the range of 125 kHz. The shielding 4 can be coupled via the control and evaluation device 6 with a constant shielding potential, while the sensor electrode 5 is operated as a capacitive sensor.

The control of a sensor electrode as a capacitive sensor is described in detail in the prior art. In particular, under the control of the control and evaluation device, multiple transposition of the sensor electrode takes place in order to detect the capacitance of the sensor electrode, which is influenced by an approach of an object, for example the hand of a user.

Figure 2 shows schematically the opposite sides of the circuit board 3, for clarity in this

Representation is shown unfolded. The top cover surface of the printed circuit board 3 shown in FIG. 2 above shows a fork-like conductor structure which forms the shielding 4. The bottom cover surface of the printed circuit board shown in Figure 2 below

FIG. 3 shows a fork structure with two prongs, which the

Sensor electrode 5 forms. It should be noted that in Figure 2, the circuit board 2 is represented by two separate elements, but in reality forms a single circuit board. The control and evaluation device is coupled in this illustration both with the shield 4 and the sensor electrode 5. The broken lines in Figure 2 show one

Area through which a section was cut in Figure 3 schematically. The circuit board is adapted in their dimensions to the space of the door handle 1. The dimensions of the printed circuit board 3 are approximately in this embodiment

80 mm x 13 mm x 1 mm. FIG. 3 shows the printed circuit board 3, on the underside of which the conductor tracks of the sensor electrode 5 are shown. On the opposite side of the circuit board, the shield 4 can be seen. The shield 4 is, as shown in Figure 3, between the sensor electrode 5 and the antenna coil. 2

arranged. It can also be seen that the shield 4 and the sensor electrode 5 are not arranged congruently in the circuit board plane of the circuit board 3. Rather, the branching ladder of the shielding 4 take the ladder of the

Sensor electrode 5 as a by covering areas laterally of the sensor electrode 5 and a central region

largely free, in which the projection of the

Sensor electrode 5 is located. It has been found that such an arrangement offers optimized shielding of the sensor electrode 5 with respect to the antenna coil 2.

Claims

claims

1. A vehicle door handle with a capacitive sensor arrangement, wherein an antenna coil with at least one

Coil winding is received in a handle housing,

wherein a sensor electrode spaced from the

Antenna coil is received in the handle housing, so that the sensor electrode extends with its longest extent in the direction of the winding axis of the coil winding, wherein the sensor electrode and the antenna coil in the direction of their respective longest extent at least partially

overlap,

wherein the sensor electrode and the antenna coil are coupled to a control and evaluation circuit,

characterized,

in that at least one electrically conductive shield is arranged between the sensor electrode and the antenna coil, which can be coupled to a shielding potential by means of the control and evaluation circuit,

wherein the control and evaluation circuit is adapted to drive the sensor electrode, the shield and the antenna coil such that the antenna coil is controlled in a time-delayed manner to the sensor electrode and the shield

is controlled at least together with the sensor electrode, so that the shield at least temporarily with the

Abschirmpotenzial is coupled when the sensor electrode is driven.

2. Vehicle door handle according to claim 1, wherein the

Sensor electrode and the shield on a common PCB, but at different levels of

Printed circuit board are applied.

3. A vehicle door handle according to claim 2, wherein the

Sensor electrode and the shield are each formed as conductor tracks on the circuit board.

4. The vehicle door handle according to claim 3, wherein the sensor electrode has branched conductor structures extending on at least one of the planes of the circuit board.

5. A vehicle door handle according to any one of claims 3 to 4, wherein the shield has branched conductor structures extending on at least one of the planes of the circuit board.

6. Vehicle door handle according to one of claims 4 to 5, wherein at least one of the conductor structures is fork-shaped, wherein from a common conductor base emanates a plurality of parallel conductor tracks.

7. A vehicle door handle according to any one of claims 4 to 6, wherein the largest dimension of the sensor electrode is between 80% and 120% of the maximum extent of the shield.

8. A vehicle door handle according to any one of claims 4 to 7, wherein the sensor electrode and the shield in directions parallel to the circuit board level with congruent

Geometry are formed.

9. The vehicle door handle according to one of claims 4 to 7, wherein the sensor electrode and the shield in directions parallel to the printed circuit board plane in such a way are formed of different geometry, that in a direction perpendicular to the circuit board plane of the

Sensor electrode occupied sensor electrode areas overlap with the areas free of the shield sections.

10. Vehicle door handle according to one of the preceding

Claims, wherein the smallest distance between the sensor electrode and the antenna coil is less than 6 mm, preferably less than 3 mm.