APPARATUS COMPRISING A MOVABLE OBJECT AND A DEVICE FOR DETECTING A MOVEMENT OF THE OBJECT, INPUT DEVICE INCLUDING THE APPARATUS, AND METHOD OF OPERATING THE APPARATUS

Abstract

The invention relates to an apparatus comprising a primary coil, an object movable relative to the primary coil, and a device for detecting a movement of the object relative to the primary coil. This device comprises an electrical resonance circuit and at least one secondary coil with one or more coil windings, which secondary coil is moved with or starting from the object. The device comprises a measuring device for detecting and/or processing at least one physical variable of the electrical resonance circuit, which variable changes during the movement of the object between the first position and the second position and outputs at least one electrical signal that is dependent on the change in the physical variable.

The invention further relates to an input device with one or more such apparatuses and to a method for operating such an apparatus or such an input apparatus.

Claims

1. Apparatus (1) comprising a primary coil (L1), an object (3) movable relative to the primary coil (L1), and a device (10) for detecting a movement of the object (3) relative to the primary coil (L1), wherein this device (10) comprises an electrical resonance circuit (11) and at least one secondary coil (L2) with one or more coil windings, which secondary coil is moved with or starting from the object (3), wherein the primary coil (L1) has one or more windings and is part of the resonance circuit (11) which also comprises at least one capacitor (C1), wherein the secondary coil (L2) is short-circuited (12), wherein the primary coil (L1) and the secondary coil (L2) are inductively coupled to one another during a movement of the object (3) between a first position and a second position and thus also during a corresponding movement of the secondary coil (L2), and the strength of the inductive coupling between the primary coil (L1) and the secondary coil (L2) and thus at least one physical variable of the resonance circuit (11) change during this movement, wherein the device (10) for detecting a movement of the object (3) relative to the primary coil (L1) comprises a measuring device for detecting and/or processing at least one physical variable of the electrical resonance circuit (11), which variable changes during the movement of the object (3) between the first position and the second position, and outputs at least one electrical signal that is dependent on the change in the physical variable.

2. Apparatus (1) comprising a primary coil (L1), an object (3) movable relative to the primary coil (L1), and a device (10) for detecting a movement of the object (3) relative to the primary coil (L1), wherein this device (10) comprises an electrical resonance circuit (11) and at least one secondary coil (L2) with one or more coil windings, wherein the primary coil (L1) has one or more windings and is part of the resonance circuit (11), which also comprises at least one capacitor (C1), wherein the secondary coil (L2) is short-circuited (12), wherein the primary coil (L1) and the secondary coil (L2) are inductively coupled via a core, wherein either the core and the secondary coil (L2) are arranged on or in the movable object (3) or the secondary coil (L2) is arranged in a stationary manner relative to the primary coil (L1) and only the core is arranged on or in the movable object (3), so that, during the movement of the object (3), there is a relative movement between the core and the secondary coil (L2) on the one hand and the primary coil (L1) on the other hand, or between the core on the one hand and the secondary coil (L2) and the primary coil (L1) on the other hand, and this relative movement changes the strength of the inductive coupling between the primary coil (L1) and the secondary coil (L2) and thus at least one physical variable of the resonance circuit (11), wherein the device (10) for detecting a movement of the object (3) relative to the primary coil (L1) comprises a measuring device for detecting and/or processing at least one physical variable of the electrical resonance circuit (11), which variable changes during the movement of the object (3) between a first position and a second position, and outputs at least one electrical signal that is dependent on the change in the physical variable.

3. Apparatus (1) according to claim 1, characterized in that the short-circuited secondary coil (L2) is a planar coil and/or has exactly one winding, this winding being short-circuited.

4. Apparatus (1) according to claim 1, characterized in that the short-circuited secondary coil (L2) has exactly one winding, this winding being short-circuited, the secondary coil being or comprising an element made of a conductive material which has a continuous recess (13) so that the conductive material surrounding this recess (13) is the short-circuited winding of the secondary coil (L2).

5. Apparatus (1) according to claim 1, characterized in that the secondary coil (L2) is a short-circuited spiral spring or a stamped and/or bent part made from sheet metal.

6. Apparatus (1) according to claim 1, characterized in that the secondary coil (L2) has a switch (14) for interrupting the short circuit (12).

7. Apparatus (1) according to claim 1, characterized in that that the apparatus (1) comprises a circuit substrate (2) to which the primary coil (L1) is connected in a stationary manner.

8. Apparatus (1) according to claim 7, characterized in that that the primary coil (L1) is a planar coil and/or is arranged on and/or in the circuit substrate (2) and/or on an upper side and/or an underside of the circuit substrate (2) and/or between at least two layers within a multilayer circuit substrate (2).

9. Apparatus (1) according to claim 1, characterized in that the one or more windings of the secondary coil (L2) lie in a plane parallel to a flat extension of the circuit substrate (2).

10. Apparatus (1) according to claim 1, characterized in that the primary coil (L1) has a primary coil axis and the secondary coil (L2) has a secondary coil axis, the primary coil axis and the secondary coil axis being inclined at most 90° to one another or running parallel to one another.

11. Apparatus (1) according to claim 1, characterized in that the measuring device is set up in such a way that when at least one change limit value of the physical variable is reached or exceeded, the at least one electrical signal is output and/or that the signal strength of the at least one electrical signal changes as a function of the change in the physical variable.

12. Apparatus (1) according to claim 11, characterized in that the change limit value or the change limit values are adjustable.

13. Apparatus (1) according to claim 1, characterized in that the measuring device is set up in such a way that the signal strength of the at least one electrical signal is dependent on the position of the object (3) relative to the primary coil (L2) and/or on the distance between the primary coil (L1) and the secondary coil (L2).

14. Apparatus (1) according to claim 1, characterized in that the movable object (3) can be moved perpendicular to the primary coil (L1) and/or in a linear movement relative to the primary coil (L1).

15. Input device comprising one or more apparatuses (1) according to claim 1.

16. Method for operating an apparatus (1) according to claim 1, with which method the movement of the object (3) relative to the primary coil (L1) is detected and which comprises the following steps: a) carrying out a movement of the object (3) relative to the primary coil (L1) in such a way that the inductive coupling between the primary coil (L1) and the secondary coil (L2) and thus also at least one physical variable of the resonance circuit (11) changes; b) detecting and/or processing the at least one physical variable of the resonance circuit (11) by means of the measuring device, which variable changes due to the movement; c) outputting at least one electrical signal when a change limit value of the physical variable is reached or exceeded and/or the signal strength of the at least one electrical signal changes as a function of the change in the physical variable.

17. Method according to claim 16, characterized in that the resonance circuit (11) is operated with an alternating voltage (U1) of predetermined and/or adjustable frequency and is adjusted in such a way by adjusting or selecting the frequency and/or by adjusting or selecting the capacitance of the capacitor (C1) and/or by adjusting or selecting a resistor arranged in the resonance circuit (11) that the resonance circuit (11) is in the resonance range at a predetermined position of the object (3) relative to the primary coil (L1).

Description

[0060] The invention is explained in more detail below also with regard to further features and advantages on the basis of the description of embodiments and with reference to the accompanying schematic drawings, in which

[0061] FIG. 1 is an embodiment of an apparatus according to the invention in an exploded view,

[0062] FIG. 2 is a representation to explain the principle of operation on which the invention is based, and

[0063] FIG. 3 is the exemplary representation of a device for detecting a movement of the object of an embodiment of the apparatus according to the invention as a circuit diagram.

[0064] Corresponding parts and components are each provided with the same reference signs in all figures.

[0065] FIG. 1 shows an embodiment of an apparatus 1 according to the invention in an exploded view. The apparatus 1 is used, for example, in a keyboard or specifically in connection with a key on the keyboard. The apparatus 1 comprises a circuit substrate 2, in this case a printed circuit board, and an object 3 that is movable relative to the circuit substrate 2, in this case a key cap 3. The key cap 3 is movably attached to the circuit substrate 2 via a movement mechanism 15, in FIG. 1, for example, a double wing mechanism comprising a base 16, two wing elements 17, and a spring 18 connecting the two wing elements 17 and can be moved perpendicular to the circuit substrate 2 in a manner known per se. Any other desired movement mechanisms 15 can also be provided, for example a scissors mechanism.

[0066] In FIG. 1, the apparatus 1 further comprises a primary coil L1, which in this case is a planar coil with a plurality of windings and is arranged on an upper side of the circuit substrate 2, specifically in the region in which the base 16 of the movement mechanism 15 is also provided. In the assembled state, the base 16 virtually surrounds the primary coil L1 designed as a planar coil.

[0067] In FIG. 1, the apparatus 1 further comprises a secondary coil L2 which is designed as a stamped part and is closed in a frame-like or ring-like manner. The secondary coil L2 consists of metal which surrounds a recess 13 in a frame-like or ring-like manner. The secondary coil L2 is thus short-circuited, and an induced electric current can flow around the recess 13. The secondary coil L2 is attached to an underside of the movable object 3 facing the circuit substrate 2, in this case the key cap 3, and is moved with this object 3. The secondary coil L2 shown in FIG. 2 has exactly one coil winding.

[0068] In FIG. 1, the primary coil L1 and the secondary coil L2 are inductively coupled to one another. This inductive coupling is also shown schematically in FIG. 2. The primary coil L1, also in FIG. 2 a planar coil with a plurality of windings on the upper side of a circuit substrate 2, is part of a resonance circuit 11, which is explained below with reference to FIG. 3 and is operated with an alternating voltage U1. As a result, the windings of the primary coil L1 are surrounded by the magnetic field 19 shown in FIG. 2. The secondary coil L2 is located in this magnetic field 19; also in FIG. 2, a ring-like or frame-like closed stamped part with a continuous recess 13, i.e. the secondary coil L2, is short-circuited and has only one winding. Due to the alternating voltage U1, the magnetic field 19 is an alternating magnetic field which, due to the inductive coupling, causes a voltage and thus, due to the short circuit, a current flow in the secondary coil L2, which in turn feeds back to the primary coil L1. If the secondary coil L2 is now moved relative to the primary coil L1, which is indicated in FIG. 2 by the double arrow in the middle, this affects the strength of the inductive coupling, and physical variables change, for example voltage and current strength, and resonance frequency of the resonant circuit 11, to which resonance circuit the primary coil L1 belongs. A measuring device (not shown in the figures) detects and processes at least one of the physical variables of the electrical resonance circuit 11, which variables change during the movement of the secondary coil L2, which movement is based on the movement of the object 3, and outputs at least one electrical signal that is dependent on the change in this physical variable.

[0069] The apparatus 1 thus comprises a device 10 (not shown in FIG. 1 and FIG. 2) for detecting a movement of the object 3 relative to the circuit substrate 2 or the primary coil L1. This device 10 is shown as a circuit diagram in FIG. 3. This device 10 comprises the already mentioned electrical resonance circuit 11 with a capacitor C1 and the primary coil L1, it being possible to additionally provide a resistor (not shown). The resonance circuit 11 is operated with an alternating voltage U1. Of this resonance circuit 11, only the primary coil L1 is shown in FIG. 1.

[0070] As can also be seen in FIG. 3, the aforementioned device 10 further comprises a secondary coil L2, the ends of which are electrically short-circuited via a short-circuit line 12. In the short-circuit line 12, a switch 14 is provided with which the short-circuit line 12 can be interrupted and closed again. The inductive coupling of the primary coil L1 and the secondary coil L2 is shown symbolically in FIG. 3 by a double arrow between the two coils L1, L2. The alternating magnetic field generated by the alternating voltage U1 induces an alternating voltage U2 in the secondary coil L2 which, when the switch 14 is closed, due to the short circuit, results in a current flow in the secondary coil L2, which results in a feedback to the primary coil L1 and thus to the resonance circuit 11, whereby—as already explained—its physical variables change, which in turn is detected by the measuring device, which measuring device has also already been explained, and results in a corresponding signal output.

LIST OF REFERENCE SIGNS

[0071] 1 Apparatus

[0072] 2 Circuit substrate, for example printed circuit board

[0073] 3 Movable object, such as a key cap

[0074] 10 Device for detecting a movement of the object 3

[0075] 11 Resonance circuit

[0076] 12 Short-circuit line of the secondary coil L2

[0077] 13 Recess in secondary coil L2

[0078] 14 Switch

[0079] 15 Movement mechanism, such as a double wing mechanism

[0080] 16 Base

[0081] 17 Wing element

[0082] 18 Spring

[0083] 19 Magnetic field

[0084] C1 Capacitor

[0085] L1 Primary coil

[0086] L2 Secondary coil

[0087] U1 Alternating voltage

[0088] U2 Induced alternating voltage of the secondary coil L2