US20220123747A1

US20220123747A1 - 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

Info

Publication number: US20220123747A1
Application number: US17/499,500
Authority: US
Inventors: Eduard Ruff
Original assignee: Cherry Europe GmbH
Current assignee: Cherry Europe GmbH
Priority date: 2020-10-15
Filing date: 2021-10-12
Publication date: 2022-04-21
Also published as: US11811399B2; DE102020132195A1; US20220123750A1; US20220123749A1; DE102020132196B4; CN114427960A; DE102020132198A1; CN114427961A; US11817857B2; DE102020132196A1; CN114374276A; DE202020105904U1

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.

Description

The invention relates to an apparatus comprising a movable object and to a device for detecting a movement of the object. The invention also relates to an input device, for example a keyboard or computer mouse, with one or more such apparatuses and to a method for operating such an apparatus or such an input apparatus.
The movement of objects must be detected in a large number of apparatuses or devices. One example is input devices such as keyboards. In keyboards, but also in numerous other apparatuses and devices, for example the actuation of a key and thus the movement of a key cap must be detected as a movable object. In order to realize the movement of key caps, the most varied types and designs of key modules are known. The movement of the key cap is detected by mechanical devices that close an electrical circuit via these key modules. In other apparatuses and devices, too, the detection of the movement of objects usually takes place mechanically.
The disadvantage of these mechanical solutions is that material wear, in particular mechanical abrasion, for example on electrical contact surfaces, is unavoidable. As a result, incorrect switching or other malfunctions up to and including breakage of mechanical components can occur with increasing service life.
Another disadvantage of mechanical solutions is that only a specific switching point can be detected during the movement of the object. This switching point is fixedly predetermined. In many applications, however, it is an advantage if this switching point can be changed so that, for example, a signal is triggered sooner or later. It would therefore be desirable to be able to adjust the switching point.
Another disadvantage of mechanical solutions is that only one signal is triggered per actuation. A variable signal, in individual steps or in finely graduated steps or also steplessly, as a function of the movement or position of the object is therefore not possible but would be advantageous in many applications.
The invention is therefore based on the object of specifying a new apparatus of the type mentioned, in particular an apparatus that allows for a longer service life compared to mechanical solutions and/or extends the detection and processing options of the movement of the object and thereby overcomes at least partially the aforementioned disadvantages. Furthermore, a new input device having such an apparatus and a method for operating such a device are to be specified.
This object is achieved by an apparatus with the features of either claim 1 or claim 2, an input device with the features of claim 15, and a method with the features of claim 16. Advantageous embodiments and developments are provided in each of the dependent claims.
The apparatus according to the invention comprises 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.
The device for detecting a movement of the object relative to the primary coil in turn comprises an electrical resonance circuit and at least one secondary coil with one or more coil windings, which secondary coil is moved with the object or is moved starting from the object, i.e. is moved due to the movement of the object. The secondary coil can be arranged on or in the object. The secondary coil can be connected to the object in a stationary manner and is thus moved with the object in such a way that the secondary coil executes the same movement as the object. It is also possible that the secondary coil is movably connected to the object in such a way, directly or indirectly via further components, that a movement of the object results in a movement of the secondary coil, but the movement of the secondary coil does not have to correspond to the movement of the object. For example, the object can execute a linear movement which results in a tilting movement in the secondary coil. This is the case, for example, when the secondary coil is movably connected to the object on the one hand and movably connected to another object that is not moved with the object on the other hand.
The primary coil has one or more windings and is part of the resonance circuit, which also comprises at least one capacitor.
The secondary coil is short-circuited. In the case of a coil with defined ends, this is understood to mean that the two ends of the coil are electrically connected to one another at least almost without resistance. This creates a circuit which at least substantially consists only of the winding or windings of the secondary coil. Furthermore, a short-circuited secondary coil is also understood to mean any closed shape, for example a ring or a frame, of an electrically conductive material that has a continuous recess or opening enclosed by the material, so that a current flow is possible around this recess or opening, for example a stamped part, in particular a ring-like or frame-like stamped part or a stamped part with a ring-like or frame-like region. In this case, no coil or winding ends can be defined, rather the short-circuited coil in this case consists of a closed winding, for example a ring or frame. In the aforementioned cases, it cannot be ruled out that the short-circuited coil has a switch via which the current flow through the short-circuited coil can be interrupted and also restored.
The primary coil and the secondary coil are inductively coupled to one another during a movement of the object between a first position and a second position and thus also during a corresponding movement of the secondary coil. During this movement, the strength of the inductive coupling between the primary coil and the secondary coil changes and thus at least one physical variable of the resonance circuit changes.
The device according to the invention for detecting a movement of the object relative to the primary coil further 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. Furthermore, this measuring device outputs at least one electrical signal that is dependent on the change in the physical variable, i.e. the measuring device has a corresponding apparatus for signal output.
The advantages of the apparatus according to the invention are in particular the contactless detection of the movement of the object and the output of an electrical signal caused by this. The mechanical solutions described at the outset and the associated problems do not apply. It is therefore possible to manufacture apparatuses and devices with less susceptibility to interference and increased service life compared to devices with mechanical solutions. Furthermore, the contactless movement detection and subsequent output of the signal allows a qualitatively constant detection or switching process; there are no changes, for example, of the switching point or the switching reliability due to mechanical abrasion or wear or breakage.
Further advantages of the invention result from the expanded detection and processing options for the movement of the object. The inductive coupling changes continuously during the movement of the object. This applies accordingly to the physical variable detected by the measuring device, so that any switching points can be adjusted in a changeable manner and also a variable signal that reflects the movement or position of the object and possibly also the speed of the movement can also be output for example in individual steps or in finely graduated steps or steplessly.
The inductive coupling of the primary and secondary coils takes place in particular in the manner of a transformer, with the secondary coil also being short-circuited.
The resonance circuit is preferably operated with alternating voltage, in particular alternating voltage with a predetermined and/or adjustable frequency, and is connected to a correspondingly equipped alternating voltage source for this purpose. The capacitor can be a variable capacitor with adjustable capacitance. Furthermore, the resonance circuit, in particular for tuning, can additionally comprise at least one resistor, in particular an adjustable resistor.
The frequency and/or the capacitor is preferably set or selected such that the resonance circuit is located in the resonance range (also: in the resonance zone) at a predetermined position of the object relative to the circuit substrate. The alternating voltage often supplies a plurality of resonance circuits of a plurality of apparatuses according to the invention, so that the frequency cannot be matched to the individual resonance circuit. In this case, the resonance circuit is adapted with regard to its resonance range by adjusting the capacitor capacitance or selecting a capacitor with a suitable capacitance. The resonance intensity or resonance bandwidth can be adjusted by adjusting or selecting the resistor or resistors.
The resonance circuit is an LC resonance circuit, and as a sub-case with resistance it is an LCR resonance circuit.
The physical variable can be an electrical voltage, an electrical current strength, or also a resonance frequency or the impedance of the primary coil. Among other things, all measurable parameters of a resonance circuit or LC/LCR circuit can be understood by this.
The inductive coupling between the primary and secondary coils can take place in primary and secondary coils without a metal core, for example an iron core. This is advantageous in the case of comparatively high-frequency operating voltages of the resonance circuit. However, it is also possible to provide a metal core in the primary and/or secondary coil, which proves to be particularly advantageous in the case of comparatively low-frequency operating voltages.
The apparatus can have exactly one secondary coil, but it is also possible to provide two or three or more secondary coils. For example, these can differ with regard to their corresponding inductive coupling with the primary coil, for example due to a different number of windings. It is possible to individually interrupt the short circuit of the individual coils by providing appropriate switches and thus to inductively couple only one or specific secondary coils to the primary coil (apart from a non-substantial additional coupling of the secondary coils with the switch open). In this way, different movements can be detected and differentiated, for example in a complex movement mechanism of the object in which a plurality of components of a secondary coil are formed.
The mode of operation of the apparatus according to the invention is explained below:
The primary coil generates an alternating magnetic field in its environment, which field penetrates the secondary coil. As a result, the primary and secondary coils are inductively coupled via the alternating magnetic field. The alternating magnetic field emanating from the primary coil induces an electrical voltage in the secondary coil. Since the secondary coil is short-circuited, this results in a current flow within the secondary coil. In comparison to a secondary coil that is not short-circuited, this current flow is comparatively strong due to the short circuit and the associated low resistance of the secondary coil.
The current flow in the secondary coil in turn affects the primary coil and thus the resonance circuit (feedback). This feedback results in a change in physical variables of the resonance circuit, for example the impedance of the primary coil, the resonance frequency, the voltage drop, and/or the current flow. If, for example, the secondary coil is at a greater distance from the primary coil in the first position than in the second position, the inductive coupling in the first position is smaller than in the second position, since the magnetic field strength and the magnetic flux density decrease with increasing distance from the primary coil, and vice versa. In this example, the feedback to the primary coil and thus the change in the physical variables is correspondingly smaller in the first position than in the second position, and vice versa. This applies accordingly to intermediate positions between the first and second position. For example, the physical variables can also change continuously or steadily in the case of a continuous or steady movement between the first and second position.
The changes in the resonance circuit due to the changing feedback result in an adjustment of the resonance circuit. If, for example, the resonance circuit is operated at its resonance frequency at a specific position of the secondary coil relative to the primary coil, the resonance frequency of the resonance circuit changes when the position of the secondary coil changes and the resonance dies away. This results in changes in physical variables such as voltage and current, which can be detected and further processed by means of the measuring device. On the basis of this detection of the change in one or more physical variables, various stepped and stepless signal processing operations can be implemented.
The same applies vice versa: If the resonance circuit is not operated at its resonance frequency, the change in the distance between the primary and secondary coil and the associated change in the inductive coupling and the resulting adjustment of the resonance circuit can cause the frequency with which the resonance circuit is operated to approach or reach its resonance frequency with corresponding effects on physical variables such as voltage and current.
For example, a differential control can also be implemented: In this case, the starting position is between the first and second position, the resonance circuit in the assumed position preferably being operated in the region of a resonance flank and being calibrated as the zero position of the detected physical variable or variables. A movement of the object in the direction of the first position can then be assessed as a negative movement of the object and a movement of the object in the direction of the second position as a positive movement of the object, based on the detected change in the physical variable or variables during the signal output, or vice versa.
If the movable object has a movement mechanism and/or further components, it is advantageous if the components of the movement mechanism and/or the further components and/or the object itself do not have any electrically closed ring-like or frame-like elements with an internal continuous recess or opening made of a conductive material such as metal, provided that these are not intended to form a secondary coil within the meaning of the invention. These elements could also couple 3o inductively to the primary coil and interfere with the inductive coupling between the primary and secondary coil. To avoid this, it is sufficient to electrically interrupt the ring or frame at least at one point in the corresponding elements. Then, no current flow is possible in these elements and there is accordingly no or at least no relevant inductive coupling to the primary coil. This state corresponds to a transformer in idle mode.
An alternative apparatus according to the invention in turn comprises 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 for detecting a movement of the object in turn comprises an electrical resonance circuit and at least one secondary coil with one or more coil windings.
The primary coil in turn has one or more windings and is part of the resonance circuit, which also comprises at least one capacitor.
In this alternative solution, too, the secondary coil is short-circuited. Reference is made to the explanations given above in connection with the solution described above; they also apply to the alternative solution.
The alternative solution provides that the primary coil and the secondary coil are inductively coupled via a core, in particular an iron core or ferrite core. In this case, either the core and the secondary coil can be arranged on or in the movable object, so that, during the movement of the object, there is a relative movement between the core and the secondary coil on the one hand and the primary coil on the other hand, and this relative movement changes the strength of the inductive coupling between the primary coil and the secondary coil and thus at least one physical variable of the resonance circuit; or, the secondary coil is arranged in a stationary manner relative to the primary coil and only the core is arranged on or in the movable object, so that, during the movement of the object, there is a relative movement between the core on the one hand and the secondary coil and primary coil on the other, and this relative movement changes the strength of the inductive coupling between the primary coil and the secondary coil and thus at least one physical variable of the resonance circuit.
In accordance with the solution described above, it is in turn provided in this alternative solution that the device for detecting a movement of the object relative to the primary coil 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 a first position and a second position, and outputs at least one electrical signal that is dependent on the change in the physical variable, i.e. the measuring device has a corresponding apparatus for signal output.
The advantages and explanations described above for the solution described above also apply analogously to the alternative solution.
A further development of the invention for both of the solutions described above provides that the short-circuited secondary coil is a planar coil. Alternatively or additionally, it can be provided that the short-circuited secondary coil has exactly one winding, this winding being short-circuited.
According to one embodiment variant, the short-circuited secondary coil has exactly one winding, this winding being short-circuited and the secondary coil being or comprising an element made of a conductive material which has a continuous recess (also: opening) so that the conductive material surrounding this recess is the short-circuited winding of the secondary coil.
The only important thing about the shape of the secondary coil is that it has a continuous recess or opening that is surrounded by the material so that an electric current can flow around the recess or opening. For example, the secondary coil can be designed in the form of a ring or frame.
According to one embodiment, the secondary coil is a short-circuited spiral spring. The spiral spring can be, for example, a return spring, in particular a compression spring, preferably with a diameter that corresponds to the diameter of the primary coil. To implement the short circuit, the two ends of the spiral spring can be electrically connected to one another, the electrical resistance of the connection being expediently low.
According to a further embodiment variant, the secondary coil is a stamped and/or bent part made from sheet metal.
A further development of the invention provides that the secondary coil has a switch for interrupting the short circuit. This switch allows for a hybrid circuit: In an initial position of the movable object and thus of the secondary coil, for example in the first or second position, the switch is open and thus the short circuit of the secondary coil is interrupted. During the movement of the object and thus the secondary coil out of the starting position, there is no or at least no significant feedback to the primary coil and the resonance circuit, the physical variables of which such as voltage and current do not change or at least do not change substantially due to the interrupted short circuit and the consequent lack of current flow in the secondary coil, and the movement of the object is not detected. If the switch is closed when a switching position is reached or exceeded and the coil is short-circuited, this results in a current flow in the secondary coil with corresponding feedback to the primary coil and thus the physical variables of the resonance circuit. Reaching the switching position and any further movement of the object is thus detected and can be further processed with regard to the output of the at least one electrical signal.
In one embodiment of the invention, the apparatus comprises a circuit substrate to which the primary coil is connected in a stationary manner. A circuit substrate is understood to mean, for example, a printed circuit board and/or a circuit board and/or a circuit foil and/or a stamped part and/or some other substrate, in particular with applied and/or integrated conductor tracks. The circuit substrate can also be built up from two or more layers, for example from two or more of the aforementioned layers. Furthermore, a circuit substrate is also understood to mean any other reference device or reference component of the apparatus with respect to which the object moves.
A further development of the invention provides that the primary coil is a planar coil and/or is arranged on and/or in the circuit substrate and/or on an upper side and/or an underside of the circuit substrate and/or between at least two layers within a multilayer circuit substrate.
As an alternative to the planar coil, the primary coil could also be a cylinder coil. Furthermore, the primary coil could also be arranged in or on a further component that is connected in a stationary manner to the circuit substrate, for example a housing.
One embodiment of the invention provides that the one or more windings of the secondary coil lie in a plane parallel to a flat extension of the circuit substrate. This is advantageous, for example, when the primary coil is designed as a planar coil on or in the circuit substrate.
According to one embodiment of the invention, the primary coil has a primary coil axis and the secondary coil has a secondary coil axis, the primary coil axis and the secondary coil axis being inclined at most 90°, preferably at most 45°, in particular at most 30°, relative to one another or running parallel to one another, preferably lie on a common straight line.
A parallel alignment of the primary coil and the secondary coil is possible, but not absolutely necessary. The primary coil and the secondary coil can also be tilted relative to one another. For example, different, ring-like, closed components of a movement mechanism of the object, which are arranged parallel to or tilted with respect to the primary coil and which consist of a conductive material, can represent a secondary coil. The secondary coil can be in one piece or also in multiple pieces; if necessary, individual parts of the secondary coil can also be movable with respect to one another.
The measuring device can be set up in such a way that the at least one electrical signal is output when at least one change limit value for the physical variable is reached or exceeded. As an alternative or in addition, the measuring device can also be set up in such a way that the signal strength of the at least one electrical signal changes as a function of the change in the physical variable.
It is possible to specify two or more different change limit values, for example a first change limit value that works with a first movement of the object and a second change limit value that is used with a second movement of the object, for example in the opposite direction.
The change limit values mentioned can be fixed. However, it is also possible for the change limit value or the change limit values to be adjustable. This has the advantage that the so-called switching point, i.e. the exact position of the object during the corresponding movement, the electrical signal being output when the object reaches the switching point, can be changed and thus adjusted without mechanical change.
The measuring device can be 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 relative to the primary coil and/or is dependent on the distance between the primary coil and the secondary coil. For example, a variable signal can be output in individual steps or in finely graduated steps or also steplessly. This is possible, for example, if the movement of the secondary coil or the object takes place in such a way that the detected physical variable changes constantly during the movement, in particular continuously and/or steplessly. The measuring device can then be set up in such a way that the electrical signal is output steplessly or in finely graduated steps or in individual steps during the movement of the secondary coil or object, preferably with a change in the signal strength which is correspondingly stepless or finely graduated or which is carried out in individual steps. For example, with a keyboard or computer mouse, a so-called joystick function can be implemented in this way, which opens up a wide range of new application possibilities in particular in the gaming sector, but also in office applications and other applications, for example when scrolling through documents, tables, and websites at variable speeds or when controlling objects at variable speeds.
One embodiment of the invention provides that the movable object can be moved perpendicular to the primary coil and/or in a linear movement relative to the primary coil. However, the movement of the object and thus of the secondary coil does not necessarily have to take place perpendicular to the primary coil or in a linear movement. For example, a rotary movement and/or a tilting movement or any three-dimensional movement can also take place.
The input device according to the invention comprises one or more of the apparatuses according to the invention. The input device can be, for example, a keyboard or a computer mouse. Each of the devices according to the invention is then assigned to a key on the keyboard or computer mouse, the circuit substrate which may be present being assigned as a rule to a plurality of or all of the apparatuses. In this case, the movable object is, for example, a key cap which is movably attached, for example, to a circuit substrate as part of a key module.
The method according to the invention relates to an operating method for the apparatus according to the invention and/or to the input device according to the invention. With this method, the movement of the object relative to the primary coil is detected. The method comprises the following steps:

- a) carrying out a movement of the object relative to the primary coil in such a way that the inductive coupling between the primary coil and the secondary coil and thus also at least one physical variable of the resonance circuit changes;
- b) detecting and/or processing the at least one physical variable of the resonance circuit 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.

The advantages of the method and further method steps emerge from the above description of the apparatus according to the invention.
According to one embodiment, the resonance circuit is operated with an alternating voltage of a predetermined and/or adjustable frequency. In this case, the resonance circuit is adjusted by adjusting or selecting the frequency and/or by adjusting or selecting the capacitance of the capacitor and/or by adjusting or selecting a resistor arranged in the resonance circuit in such a way that the resonance circuit is located in the resonance range in a predetermined position of the object relative to the primary coil.

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

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

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

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.

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

1 Apparatus
2 Circuit substrate, for example printed circuit board
3 Movable object, such as a key cap
10 Device for detecting a movement of the object 3
11 Resonance circuit
12 Short-circuit line of the secondary coil L2
13 Recess in secondary coil L2
14 Switch
15 Movement mechanism, such as a double wing mechanism
16 Base
17 Wing element
18 Spring
19 Magnetic field
C1 Capacitor
L1 Primary coil
L2 Secondary coil
U1 Alternating voltage
U2 Induced alternating voltage of the secondary coil L2

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).