Device for detecting a key press and / or a travel distance of a key module, keyboard

Abstract

Device (10) for detecting a key press and / or a travel distance of a key module (11) comprising a circuit substrate (18), a magnetic field sensor (30) arranged on or in the circuit substrate (18), a keypad module (11) attached to the circuit substrate (18) comprising a housing (12), a plunger (16), a plunger spring (17) for resetting the plunger (16) and a permanent magnet (48) cooperating with the magnetic field sensor (30), wherein the plunger (16) is movable relative to the housing (12) and perpendicular to the circuit substrate (18) between a rest position and a maximum actuation position, wherein the permanent magnet (48) is movable relative to the housing (12) and arranged such that a movement of the permanent magnet (48) causes a change in the magnetic field at the magnetic field sensor (30), wherein the permanent magnet (48) is coupled to the plunger (16) in such a way that the movement of the permanent magnet (48) originates from a movement of the plunger (16), so that the movement of the plunger (16) causes a change in the magnetic field at the magnetic field sensor (30) due to the coupled movement of the permanent magnet (48), wherein the magnetic field sensor (30) detects this change in the magnetic field and signals it to a computing unit (51) of the device (10), wherein the device (10) outputs at least one electrical signal to signal the actuation of the key and / or the actuation path of the key module (11) when the magnetic field changes, characterized by the fact that the permanent magnet (48) is mounted directly or indirectly on the housing (12) in such a way that the mobility of the permanent magnet (48) relative to the housing (12) has at least one movement component parallel to the circuit substrate (18).

Description

[0001] The invention relates to a device for detecting a key press and / or the actuation path of a key module and a keyboard comprising one or more such devices. Key modules are a central component of keyboards.

[0002] Non-contact keypads, in which a switching signal is triggered by the movement of a permanent magnet, are known. The permanent magnet is attached to a plunger of the keypad and interacts with a magnetic field sensor, such as a Hall sensor or a TMR sensor, on a circuit substrate on which the keypad is also mounted. The movement of the permanent magnet when the plunger is actuated causes a change in the magnetic field at the magnetic field sensor, thereby triggering the switching signal. The advantage of this technology is that it requires no mechanical contacts, thus reducing wear and increasing durability.

[0003] Such key modules are known from CN 218 730 554 U, CN 208 241 649 U and CN 210 518 262 U.

[0004] The familiar key modules have the disadvantage that the permanent magnets are attached to the plungers. While the implementation is very simple, it brings with it three major drawbacks: 1. The permanent magnet is attached to the plunger as an actuator and thus travels the same distance as the plunger. In doing so, the permanent magnet moves towards the magnetic field sensor. This is typically a distance of 3 to 4 mm. The magnetic field of a permanent magnet decreases disproportionately with distance from its magnetic poles. At a relatively large distance between the permanent magnet and the magnetic field sensor, the change in magnetic field strength and / or the change in the angle of the magnetic field lines at the magnetic field sensor is relatively small. This makes the detection of the signal change inaccurate and sometimes even impossible. 2. Due to the non-proportional magnetic field distribution of a permanent magnet, the magnetic field sensor is also activated non-proportional when the button module is pressed. This results in a highly non-linear signal path characteristic. While it is possible to improve linearity by converting the counts during signal evaluation, this leads to increased inaccuracy in the switching paths and / or increases the cost of the final product. Furthermore, such conversion requires a correspondingly high processing capacity from the microcontroller. This increases the response time and power consumption. 3. A relatively large distance between the permanent magnet and the magnetic field sensor allows for easy manipulation of the circuit by a separate permanent magnet, such as watches with magnetic clasps or toys containing permanent magnets. This can easily disable the keyboard or trigger unintended keystrokes.

[0005] The invention is therefore based on the objective of providing a new device for detecting a key press and / or an actuation path of a key module, in particular a device that at least partially overcomes the aforementioned disadvantages. Furthermore, a keyboard comprising one or more such devices is to be provided.

[0006] This problem is solved with respect to the device by a device having the features of claim 1 and with respect to the keyboard by a keyboard having the features of claim 32. Advantageous embodiments and further developments are specified in the dependent claims.

[0007] The device according to the invention for detecting a key press and / or an actuation path of a key module comprises a circuit substrate, for example a printed circuit board, and a magnetic field sensor arranged on or in the circuit substrate.

[0008] The device further comprises a keypad module attached to the circuit substrate, with a housing, in particular a two-part housing comprising a first and a second housing part, a plunger, a plunger spring for resetting the plunger, and a permanent magnet interacting with the magnetic field sensor. The plunger is movable relative to the housing and perpendicular to the circuit substrate between a rest position and a maximum actuation position.

[0009] The permanent magnet is movable relative to the housing and arranged in such a way that a movement of the permanent magnet causes a change in the magnetic field at the magnetic field sensor, for example a change in the strength of the magnetic field and / or a change in the orientation of the magnetic field lines.

[0010] The permanent magnet is coupled to the plunger in such a way that the movement of the permanent magnet originates from a movement of the plunger, so that the movement of the plunger, due to the coupled movement of the permanent magnet, causes a change in the magnetic field at the magnetic field sensor.

[0011] The magnetic field sensor detects this change in the magnetic field and signals this change in the magnetic field to a computing unit of the device, wherein the device outputs at least one electrical signal to signal the actuation of the key and / or the actuation path of the key module when the magnetic field changes.

[0012] The invention provides that the permanent magnet is mounted directly or indirectly on the housing in such a way that the mobility of the permanent magnet relative to the housing has at least one movement component parallel to the circuit substrate.

[0013] In other words, when the keypad is activated, the plunger moves perpendicular to the circuit substrate, causing the permanent magnet to move. This permanent magnet has at least one component of movement parallel to the circuit substrate, meaning it moves across the substrate. With a suitable magnetic field sensor, the permanent magnet will also move towards, past, and / or over the magnetic field sensor. The movement of the permanent magnet can be, for example, a rotational movement, such as along a circle, or a pseudo-rotational movement, which is explained in more detail below. A linear, or at least nearly linear, movement parallel or at an angle to the circuit substrate is also possible.

[0014] When the keypad module is actuated, the plunger is typically moved from its rest position or an already assumed actuation position towards its maximum actuation position. It may be provided that the effects described above in connection with actuation also occur analogously during the opposite movement of the plunger from an actuation position towards its rest position, i.e., typically when releasing a key on the keypad module, also due to the coupling between the plunger and the permanent magnet. This return to the rest position is initiated by the plunger spring, which is increasingly tensioned when the keypad module is actuated.

[0015] The term "parallel to the circuit substrate" is understood above and below to mean, in particular, "parallel to the surface of the circuit substrate." Specifically, it is assumed that the circuit substrate is planar and / or flat and / or even.

[0016] The advantages of the invention lie particularly in the fact that the permanent magnet is not directly attached to the plunger as the actuator of the keypad module and therefore does not have to travel the same path as the plunger. Rather, the plunger and permanent magnet are coupled in such a way that, although the permanent magnet is also moved by the movement of the plunger, the paths of movement of the plunger and the permanent magnet differ. The movements diverge from one another: the linear movement of the plunger perpendicular to the circuit substrate is contrasted with a movement of the permanent magnet that has at least one component parallel to the circuit substrate. Furthermore, the transmission of motion from the plunger to the permanent magnet need not be linear and / or proportional; a non-linear and / or non-proportional transmission is also possible.For example, the movement of the permanent magnet can be coupled to the movement of the plunger by means of a variable transmission mechanism, such as a variable gear. This makes it possible to both define an arbitrary motion transmission coefficient and to vary the motion transmission coefficient as desired during actuation.

[0017] A further development of the invention provides that the permanent magnet is arranged inside the housing of the keypad module. For example, the permanent magnet can be arranged in any intended movement position in the half of the housing of the keypad module facing the circuit substrate. The permanent magnet and the magnetic field sensor are arranged, in particular, such that the movement of the permanent magnet occurs in close proximity to the magnetic field sensor.

[0018] The arrangement of the permanent magnet in the immediate vicinity of the magnetic field sensor, with the possibility of movement at least with a movement component parallel to the circuit substrate, has the following advantages: 1. Additional magnetic fields from outside the key module or keyboard may have no effect or a significantly weaker effect on the detection of key presses. 2. Due to its greater proximity to the magnetic field sensor, the magnetic field of the permanent magnet can be significantly weaker. This allows the use of much smaller permanent magnets and / or permanent magnets made from inexpensive magnetic materials, such as ferrite or iron magnets, thereby reducing manufacturing costs.

[0019] The permanent magnet can be a bar magnet in which the north and south poles are arranged along a longitudinal or transverse axis of the permanent magnet. For example, the permanent magnet can be arranged such that the longitudinal axis and / or the transverse axis and / or a magnetic field axis (also: magnetization direction) of the permanent magnet runs parallel to the circuit substrate and / or perpendicular to a path of movement of the permanent magnet.

[0020] The magnetic field sensor can be located on the front side facing the keypad module, on the back side of the circuit substrate facing away from the keypad module, or within the circuit substrate itself.

[0021] The magnetic field sensor can, for example, be a Hall sensor. Specifically, the Hall sensor and the permanent magnet are arranged such that the change in the magnetic field at the Hall sensor caused by the movement of the permanent magnet during the plunger's movement from its rest position to its maximum actuation position is a continuous increase in magnetic field strength. For example, a magnetic field axis of the permanent magnet, viewed perpendicular to the circuit substrate, can extend through the area of ​​the Hall sensor in the plunger's maximum actuation position. The magnetic field axis is a straight line extending beyond the permanent magnet. Viewed perpendicular to the circuit substrate, the Hall sensor can therefore also be positioned in front of the north or south pole of the permanent magnet in the plunger's maximum actuation position.

[0022] The magnetic field sensor can also be a TMR sensor (TMR: Tunnel Magneto-Resistance). A TMR sensor changes its resistance depending on the orientation of the magnetic field lines, i.e., the magnetic field direction. The TMR sensor can therefore detect changes in the orientation of the magnetic field. The TMR sensor can thus also be called an angle sensor.

[0023] For example, the TMR sensor can be positioned perpendicular to the circuit substrate in each intended movement position of the permanent magnet, either on the north or south pole side, for instance, inside or outside the permanent magnet. The permanent magnet is thus moved past the north or south pole. The advantage of this arrangement is the significant signal change, since the change in the orientation of the magnetic field lines, and therefore the angular change of the magnetic field, is greater near the poles during relative movement between the permanent magnet and the TMR sensor than at greater distances. Shorter movement distances near the poles can therefore already lead to a significant signal change from the TMR sensor.

[0024] It is also possible that the permanent magnet, viewed perpendicular to the circuit substrate, moves past the TMR sensor from its rest position to its maximum actuation position when the plunger moves. This can lead to an S-shaped signal path characteristic.

[0025] A further development of the invention provides that, in addition to the magnetic field sensor, at least one further magnetic field sensor is arranged on or in the circuit substrate, which interacts with the permanent magnet in such a way that a movement of the permanent magnet originating from a movement of the plunger also causes a change in the magnetic field at the at least one further magnetic field sensor, and the at least one further magnetic field sensor also detects the change in the magnetic field and signals it to the processing unit of the device. All described further developments concerning the magnetic field sensor also apply analogously to the second magnetic field sensor.

[0026] All magnetic field sensors can be, for example, Hall sensors or TMR sensors. Each magnetic field sensor can be assigned to one of the opposite magnetic poles. The sensors can be arranged and / or connected in parallel, meaning that when the button module is pressed, for example, a signal increase is generated simultaneously at both sensors. However, the sensors can also be arranged and / or connected in opposite directions and / or offset, for example, to implement a differential circuit. In this case, when the button module is pressed, the signal value at one sensor might increase while the signal value at the other sensor decreases. This allows for the implementation of additional functions, particularly in gaming applications.

[0027] A further development of the invention provides that the coupling of the permanent magnet to the plunger comprises a motion transmission mechanism that transfers the movement of the plunger perpendicular to the circuit substrate into the movement of the permanent magnet with the motion component parallel to the circuit substrate.

[0028] The motion transmission mechanism may include an auxiliary actuator located within the keypad module. The permanent magnet is attached to and / or within the auxiliary actuator, or integrated into the auxiliary actuator. Furthermore, the permanent magnet is mounted to the housing via the auxiliary actuator.

[0029] One embodiment provides that the auxiliary actuator has a fixing leg and a control leg, which are connected to each other at one end. The auxiliary actuator is fixed to the housing by means of its fixing leg, for example, by being inserted into a corresponding recess in the housing. The permanent magnet is attached to the control leg at or near a free end of the control leg. The control leg is coupled to the plunger to transmit the movement of the plunger into the movement of the permanent magnet.

[0030] In particular, the control arm is movable relative to the fixing arm. Specifically, the control arm can perform a rotational movement around an axis of rotation located in the connection area of ​​the two arms and aligned parallel to the circuit substrate. It can also be a pseudo-rotational movement, i.e., almost a rotational movement, if the transition area and thus the axis of rotation shift slightly during the movement.

[0031] In one embodiment, the fixing leg and control leg are connected in a U-shape in a side view.

[0032] The connection area, for example the U-shaped transition area between the legs, can be supported on the housing in addition to the fixing leg. However, this is not absolutely necessary.

[0033] The aforementioned coupling between the plunger and the control arm of the auxiliary actuator can be achieved by the control arm bearing against the plunger, the plunger having a guide profile that interacts with a control profile of the control arm. As the plunger moves, the control profile of the control arm slides along the guide profile of the plunger, thereby causing movement of the control arm relative to the fixing arm and thus movement of the permanent magnet relative to the housing, with the movement component parallel to the circuit substrate.

[0034] Furthermore, it may be provided that the fixing arm and control arm form a return spring for the control arm, or that a return spring is integrated and / or arranged and / or attached to the control arm and resting against the housing, wherein the return spring is pre-tensioned and, due to its pre-tension, ensures that the control profile of the control arm rests against the guide profile of the plunger. If the return spring is a separate spring that is arranged and / or attached to the control arm of the auxiliary actuator, the separate spring may, for example, be designed as a bending spring, compression spring, tension spring, or torsion spring.

[0035] In conjunction with the aforementioned U-shape, the auxiliary actuator can thus form a U-spring, in particular a U-spring where the U-transition between the legs is supported by the housing. This minimizes overall friction and wear, thereby increasing the service life.

[0036] Additionally, the control profile of the control arm may include a control cam that projects towards the guide profile of the tappet. Alternatively, two or more control cams may be provided, which interact accordingly with two or more guide profiles or two or more sections of the guide profile on the tappet.

[0037] One embodiment provides that the transfer of the movement of the plunger into the movement of the permanent magnet is determined by the shape of the plunger's guide profile.

[0038] Furthermore, it can be provided that the guide profile on the plunger decreases at least section by section in the opposite direction to an intended actuation movement of the plunger, so that a constant plunger movement in the actuation direction when the control cam slides along the constantly decreasing section of the guide profile leads to a constant speed of movement of the permanent magnet away from the fixing leg.

[0039] It can also be provided that the guide profile on the plunger decreases continuously, at least section by section, in the opposite direction to an intended actuation movement of the plunger, so that a constant plunger movement in the actuation direction, as the control cam slides along the continuously decreasing section of the guide profile, leads to a decreasing speed of movement of the permanent magnet away from the fixing leg.

[0040] It can also be provided that the guide profile on the plunger increases at least section by section in the opposite direction to an intended actuation movement of the plunger, so that a constant plunger movement in the actuation direction, as the control cam slides along the constantly increasing section of the guide profile, leads to a constant speed of movement of the permanent magnet towards the fixing leg.

[0041] Furthermore, it can be provided that the guide profile on the plunger, contrary to an intended actuation movement of the plunger, continuously increases in thickness at least in sections, so that a constant plunger movement in the actuation direction, as the control cam slides along the continuously increasing section of the guide profile, leads to a decreasing speed of movement of the permanent magnet towards the fixing leg.

[0042] Thus, by adjusting the contour of the guide profile, the existing non-linearity of the signal-path characteristic at the magnetic field sensor can be further linearized depending on the sensor placement and sensor type, or the sensor sensitivity can be increased in the desired path range.

[0043] One embodiment provides that the guide profile on the plunger forms a projection, so that during a planned actuation movement of the plunger, the control cam slides up to a vertex of the projection against an increasing force of the return spring, which requires an increasing effort when actuating the plunger, which ceases after passing the vertex of the projection, so that passing the vertex of the projection simultaneously causes a tactilely perceptible pressure point effect and a sudden change in the direction of movement of the permanent magnet.

[0044] A further development of the aforementioned embodiment provides that the plunger comprises a main body, which executes the plunger's movement, and a moving element. The main body has a bottom surface facing the circuit substrate and a top surface opposite the bottom surface, and at least one recess laterally between the bottom surface and the top surface. The moving element is inserted into this recess and rotatably mounted on the bottom of the recess, opposite an opening of the recess, about an axis of rotation perpendicular to the intended direction of movement of the main body. The recess defines a space for movement of the moving element, with an upper stop on the top surface of the main body and a lower stop on the bottom surface of the main body, within which the moving element can rotate between the upper and lower stops.The moving body forms at least part of the guide profile for the plunger, with the guide profile forming a projection in the area of ​​the moving body and a recess on the side of the projection facing the underside of the main body. In the plunger's rest position, the moving body rests against the lower stop, and the control cam rests in or near the recess, or on the side of the recess opposite the projection. When the plunger moves from the rest position toward its maximum actuation position, the moving body is initially moved toward the upper stop, and the control cam rests in the recess on the moving body. As the plunger moves further, the moving body initially rests against the upper stop, and the control cam slides out of the recess to the apex of the projection, and then the control cam passes over the apex of the projection.In this process, the moving body is abruptly moved to the lower stop, thereby generating a stop noise, and the permanent magnet is moved across the circuit substrate and relative to the magnetic field sensor.

[0045] The embodiment described above has the advantage that passing the apex of the projection not only simultaneously causes a tactilely perceptible pressure point effect and a sudden movement of the permanent magnet, resulting in a comparatively strong change in the magnetic field at the magnetic field sensor, but also simultaneously generates an impact noise that provides the operator of the keypad module with acoustic feedback of the actuation. The advantages of the further development described above lie particularly in the fact that the moving element is mounted exclusively on the main body of the plunger and does not come into contact with other housing parts of the keypad module. In addition, the moving element is rotatably mounted in the main body and can complete its rotational movement within the movement space of the main body.Since the rotational movement is small and the axis of rotation generates relatively little friction anyway, the overall friction balance is very positive. Compared to other known key modules, this key module thus provides a defined and therefore improved click sound when pressed. A further advantage is that the strong change in the magnetic field is accompanied by tactile and audible feedback, meaning that a switching and / or signaling process detected by the magnetic field change, which is then transmitted to a computer, for example, is simultaneously perceptible to the user both tactilely and audibly.

[0046] The intensity of the impact noise depends on the rotation angle of the moving body and / or its weight and / or the position of the impact surfaces and / or the spring force of the return spring of the auxiliary actuator, and can be adjusted by selecting these parameters accordingly. Furthermore, the travel distance or the force-displacement curve when actuating the button module can be adjusted by the rotation angle and the guide profile of the moving body.

[0047] The aforementioned impact noise can be achieved, as an alternative to the rotatable moving element described above, by a moving element that is linearly displaceable on the main body. In this embodiment, the plunger also comprises a main body, which executes the plunger's movement, and a moving element. The main body has a bottom surface facing the circuit substrate and a top surface opposite the bottom surface. The moving element is movably and thus linearly displaceable on the main body between an upper stop on the top surface and a lower stop on the bottom surface, parallel to the intended direction of movement of the main body.The moving body forms at least part of the guide profile for the plunger, with the guide profile forming a projection in the area of ​​the moving body and a recess on the side of the projection facing the underside of the main body. In the plunger's rest position, the moving body rests against the lower stop, and the control cam rests in or near the recess, or on the side of the recess opposite the projection. When the plunger moves from the rest position toward its maximum actuation position, the moving body is initially moved toward the upper stop, and the control cam rests in the recess on the moving body. With further movement of the plunger, the moving body initially rests against the upper stop, and the control cam slides out of the recess to the apex of the projection. Subsequently, the control cam passes over the apex of the projection.In this process, the moving body is abruptly moved to the lower stop, generating a striking noise, and the permanent magnet is moved across the circuit substrate and relative to the magnetic field sensor.

[0048] As an alternative to the configurations described above with a control cam on the control profile of the control arm, it can also be provided that the guide profile of the plunger includes a sliding cam that projects towards the control profile of the control arm of the auxiliary actuator. A further development of this provides that the transmission of the plunger's movement into the permanent magnet's movement is determined by the shape of the control profile of the control arm.

[0049] The auxiliary actuator may consist of a spring-like and / or non-magnetic material and / or of metal and / or an alloy and / or plastic, or at least comprise one or more of these materials in certain areas.

[0050] For example, the additional actuator can be a stamped metal part.

[0051] For example, the additional actuator can be bent into a U-shape from springy, non-magnetic material.

[0052] For example, the auxiliary actuator can be made of a copper alloy with spring properties.

[0053] The permanent magnet can, for example, be snapped onto the auxiliary actuator or clamped, glued, welded, soldered or otherwise attached to the auxiliary actuator.

[0054] It is also possible that the material of the auxiliary actuator is, or at least partially comprises, a magnetizable material that forms the permanent magnet. The magnetizable material could be magnetizable plastic.

[0055] The movement of the permanent magnet can be a rotational movement, a pseudo-rotational movement in a plane perpendicular or parallel to the circuit substrate, or a linear movement parallel to the circuit substrate. Pseudo-rotational movement refers specifically to a movement in which a rotational movement of the permanent magnet is approximated and / or simulated by the elastic deformation of the auxiliary actuator designed as a return spring, i.e., by the movement of the control arm relative to the fixing arm.

[0056] For example, the movement of the permanent magnet can be a pendulum motion, in particular a pendulum motion with a motion component parallel to the circuit substrate and a motion component perpendicular to the circuit substrate, where, for example, the parallel motion component is larger than the perpendicular motion component.

[0057] An example of the rotational or pseudo-rotational movement of the permanent magnet in a plane parallel to the circuit substrate is a pendulum motion that occurs entirely in a plane parallel to the circuit substrate. This is the case, for example, when the auxiliary actuator is not positioned upright in the keypad module, as shown in the figures, but lying down. The axis of the pendulum motion (also: axis of rotation or pseudo-axis of rotation) is then not parallel, but perpendicular to the circuit substrate.

[0058] The keypad module may have integrated backlighting or have its own dedicated backlighting. The backlighting may be mounted on and / or within the circuit substrate in such a way as to illuminate an associated keycap with symbols and / or the keypad module housing. One or more light guides may be integrated into the keypad module housing and / or arranged as separate components within the keypad module.

[0059] The keyboard according to the invention comprises one or more devices according to the invention.

[0060] The invention is further explained below with regard to other features and advantages by means of a description of exemplary embodiments and with reference to the accompanying schematic drawings.

[0061] This shows Fig. 1 in a perspective exploded view a first embodiment of the device according to the invention, Fig. 2 in a perspective sectional view the first embodiment of the device according to Fig. 1, Fig. 3 in perspective view individual components of the first embodiment of the device according to Fig. 1, Fig. 4 and Fig. 5 in different views the additional actuator of the first embodiment of the device according to Fig. 1, Fig. 6 and Fig. 7 in sectional views the first embodiment of the device according to Fig. 1 in different states of motion, Fig. Figures 8 to 10 show a second embodiment of the device according to the invention in various states of motion, wherein the second embodiment differs from the first embodiment in the shape of the guide profile of the plunger. Fig. Figures 11 to 13 show a third embodiment of the device according to the invention in various states of motion, wherein the third embodiment differs from the first and second embodiments in the shape of the guide profile of the plunger. Fig. 14 and Fig. 15 a variant of the plunger different from the plunger of the first to third embodiments in various representations, Fig. 16 and Fig. 17 the main body of the pestle after Fig. 14 and Fig. 15 in various representations, Fig. 18 and Fig. 19 the moving body of the plunger after Fig. 14 and Fig. 15 in various representations, Fig. Figures 20 to 23 show a fourth embodiment of the device according to the invention in various states of motion, wherein the fourth embodiment shows the plunger after Fig. 14 and Fig. 15 Fig. 24 and Fig. 25 one to the pestle in Fig. 14 and Fig. 15 different variants of the pestle in various representations, Fig. 26 a schematic representation for an exemplary explanation of the arrangement of a permanent magnet and a magnetic field sensor in the form of a TMR sensor in a device according to the invention.

[0062] Corresponding parts and components are marked with the same reference symbols in all figures.

[0063] Fig. 1 to Fig. Figure 3 shows a first embodiment of a device 10 according to the invention in a perspective view. The device 10 comprises a circuit substrate 18, for example a printed circuit board, a keypad module 11 attached to the circuit substrate 18, and two magnetic field sensors 30 arranged on a front face of the circuit substrate 18 facing the keypad module 11. The device 10 serves to detect a key press and / or an actuation path of the keypad module 11. Fig. Figure 1 shows the device 10 in a perspective exploded view. Fig. Figure 2 shows the device 10 in a perspective sectional view, with the keypad module 11 mounted on the circuit substrate 18 and the interior of the keypad module 11 visible. Fig. Figure 3 shows several components of the keypad module 11 hidden in perspective view, so that the components shown are easier to see. The two magnetic field sensors 30 and a light source 50, for example an LED, can be seen on the circuit substrate 18.

[0064] The key module 11 comprises a housing 12, which consists of a first housing part 13, a top part or cover, and a second housing part 14, a bottom part or base. The key module 11 further includes a plunger 16 and a plunger spring 17 arranged between the plunger 16 and the second housing part 14 for resetting the plunger 16. The plunger 16 is movable relative to the housing 12 and perpendicular to the circuit substrate 18 between a rest position and a maximum actuation position. A keycap 49 is mounted on the plunger 16.

[0065] The keypad module 11 further comprises a permanent magnet 48, which interacts with the two magnetic field sensors 30. The permanent magnet 48 is mounted inside the housing 12 of the keypad module 11 on an auxiliary actuator 19, which is described in more detail below. The auxiliary actuator 19 allows the permanent magnet 48 to move relative to the housing 12. In each intended position of movement, the permanent magnet 48 is located in the second housing part 14, and thus in a half of the housing 12 facing the circuit substrate 18. The permanent magnet 48 therefore moves close to the magnetic field sensors 30. It is explained below that the permanent magnet 48 is arranged such that a movement of the permanent magnet 48 causes a change in the magnetic field at the magnetic field sensors 30.

[0066] The auxiliary actuator 19 is part of a motion transmission mechanism 15, with which the permanent magnet 48 is coupled to the plunger 16 in such a way that the movement of the permanent magnet 48 originates from a movement of the plunger 16, so that the movement of the plunger 16 causes a change in the magnetic field at the magnetic field sensors 30 due to the coupled movement of the permanent magnet 48.

[0067] The magnetic field sensors 30 detect this change in the magnetic field and signal it to a computing unit 51 of the device 10, which is located in Fig. 1 and Fig. 3 is only symbolically indicated by a dashed line and can also be arranged at a different location on the circuit substrate 18 or outside the circuit substrate 18. The device 10 is designed to output at least one electrical signal to signal the actuation of the key and / or the actuation path of the key module 11 when the magnetic field changes.

[0068] The permanent magnet 48 is indirectly mounted on the housing 12 via the auxiliary actuator 19. It is explained in more detail below that this mounting is such that the mobility of the permanent magnet 48 relative to the housing 12 has at least one movement component parallel to the circuit substrate 18. The motion transmission mechanism 15 is designed to transmit a movement of the plunger 16 perpendicular to the circuit substrate 18 into this movement of the permanent magnet 48 with the movement component parallel to the circuit substrate 18.

[0069] The permanent magnet 48 shown is a cylindrical bar magnet in which the north and south poles are arranged along a longitudinal axis of the permanent magnet 48. The longitudinal axis of the permanent magnet 48 runs parallel to the circuit substrate 18 and perpendicular to a path of movement of the permanent magnet 48.

[0070] Fig. 4 and Fig. Figure 5 shows the aforementioned additional actuator 19 in different views. Fig. 4 is a perspective view. Fig. Figure 5 is a sectional view. The auxiliary actuator 19 is a one-piece component and has a fixing leg 20 and a control leg 21, which are connected to each other at one end of the two legs 20, 21. In the side sectional view in Fig. Figure 5 shows that the fixing leg 20 and the control leg 21 are connected to each other in a U-shape. The auxiliary actuator 19 is fixed to the housing 12 by means of its fixing leg 20, for example, by the fixing leg 20 being inserted into a corresponding recess in the second housing part 14 of the housing 12. The control leg 21 has a holder 52 at one free end for attaching the permanent magnet 48, in which the permanent magnet 48 is held, for example, by clamping.

[0071] The control arm 21 is coupled to the plunger 16 to transmit the movement of the plunger 16 into the movement of the permanent magnet 48. For this purpose, the control arm 21 has a control profile 35, which is present twice in the example shown, and which interacts with a guide profile 34 on the plunger 16, which is also present twice (see Fig. 3) The coupling between plunger 16 and control arm 21 is achieved by the control arm 21 bearing against the guide profile 34 of the plunger 16 with its control profile 35. When the plunger 16 moves, the control profile 35 of the control arm 21 slides along the guide profile 34 of the plunger 16. This causes movement of the control arm 21 relative to the fixing arm 20 and thus movement of the permanent magnet 48 relative to the housing 12, with the movement component parallel to the circuit substrate 18.

[0072] The fixing leg 20 and the control leg 21 form a return spring 45 for the control leg 21. This can be achieved, for example, by making the auxiliary actuator 19 from a resilient material, such as an alloy. The return spring 45 is pre-tensioned in the keypad module 11. It rests against the housing 12 via the fixing leg 20 and, due to its pre-tension, ensures that the control profile 35 of the control leg 21 rests against the guide profile 34 of the plunger 16, continuously even during the movement of the plunger 16. For this purpose, the control profile 35 of the control leg 21 includes a control cam 36, which projects towards the guide profile 34 of the plunger 16 and rests against the guide profile 34. During movement of the plunger 16, the cam slides along the shape (also: contour) of the guide profile 34.

[0073] The design of the auxiliary actuator 19 as a return spring 45 enables the movement of the control arm 21 relative to the fixing arm 20. In this process, the control arm 21, and thus also the permanent magnet 48 attached to the control arm 21, perform a pseudo-rotational movement in a plane perpendicular to the circuit substrate 18. A pseudo-rotational movement is understood to be a movement that is almost a rotational movement, but in which the axis of rotation can shift slightly during the movement, thus forming a pseudo-rotational axis, as is the case, for example, with the U-shaped auxiliary actuator 19 in the area of ​​the U-shaped return spring 45. The pseudo-rotational axis is located in the area of ​​the U-shaped transition between the fixing arm 20 and the control arm 21 and runs parallel to the circuit substrate 18, but can shift within the U-shaped transition area during the spring-loaded movement of the auxiliary actuator 19.The permanent magnet 48 performs a kind of pendulum motion. Its motion has a component parallel to the circuit substrate 18 that is larger than the component perpendicular to the circuit substrate 18.

[0074] The transmission of the movement of the plunger 16 into the movement of the permanent magnet 48 is determined by the shape of the guide profile 34 of the plunger 16. Different shapes of the guide profile 34 are shown in the figures and are explained below.

[0075] For example, the guide profile 34 on the plunger 16 can decrease at least section by section in the opposite direction to an intended actuating movement of the plunger 16, so that a constant plunger movement in the actuating direction as the control cam 36 slides along the constantly decreasing section of the guide profile 34 results in a constant speed of movement of the permanent magnet 48 away from the fixing leg. An embodiment of this is shown in Fig. 1 to Fig. 3 shown. The corresponding sequence of movements, with the plunger 16 increasingly pressed into the housing 12 in the intended direction of movement, is shown in the sectional views in Fig. 6 and Fig. 7 shown, where Fig. 6 the resting position and Fig. Figure 7 shows the maximum actuation position. The comparison of Fig. 6 and Fig. Figure 7 shows how the permanent magnet 48 is moved in a pseudo-rotational motion close to the magnetic field sensors 30 and that this motion has a motion component parallel to the circuit substrate 18.

[0076] A second example of the design of the leadership profile 34 is in Fig. 8 to Fig. Figure 10 shows that the guide profile 34 on the plunger 16 decreases progressively, at least in sections, contrary to the intended actuation movement of the plunger 16. This results in a constant plunger movement in the actuation direction, as the control cam 36 slides along the progressively decreasing section of the guide profile 34, leading to a decreasing speed of movement of the permanent magnet 48 away from the fixing leg 20. The corresponding movement sequence is shown as the plunger 16 is increasingly pressed into the housing 12 in the intended direction of movement, i.e., from the rest position of the plunger 16 towards the maximum actuation position. Fig. 8, Fig. 9 and Fig. 10 shown, from the resting position in Fig. 8 via an intermediate position in Fig. 9 up to the maximum actuation position in Fig. 10. The comparison of Fig. 8, Fig. 9 and Fig. Figure 10 shows how the permanent magnet 48 is moved in a pseudo-rotational motion close to the magnetic field sensors 30 and that this motion has a motion component parallel to the circuit substrate 18.

[0077] A third example of the design of the leadership profile 34 is in Fig. 11 to Fig. Figure 13 shows that the guide profile 34 forms a projection 37 on the plunger 16. During an intended actuation movement of the plunger 16, the control cam 36 slides up to a vertex 39 of the projection 37 against an increasing force from the return spring 45, requiring an increasing force when actuating the plunger 16. This force is no longer required after passing the vertex 39 of the projection 37. Thus, passing the vertex 39 of the projection 37 simultaneously causes a tactilely perceptible pressure point effect and an abrupt change in the direction of movement of the permanent magnet 48. The corresponding movement sequence is described as the plunger 16 is increasingly pressed into the housing 12 in the intended direction of movement, i.e., from the rest position of the plunger 16 towards the maximum actuation position. Fig. 11, Fig. 12 and Fig. 13 shown, from the resting position in Fig. 11 via an intermediate position in Fig. 12 up to the maximum actuation position in Fig. 13. The comparison of Fig. 11, Fig. 12 and Fig. Figure 13 shows how the permanent magnet 48 initially hardly moves and then, as soon as the control cam 36 crosses the apex 39 of the projection 37, is suddenly moved in a pseudo-rotational movement close to the magnetic field sensors 30 and that this movement has a motion component parallel to the circuit substrate 18.

[0078] Fig. 14 to Fig. Figure 19 shows an alternative variant of the pestle 16 in various representations. The pestle 16 has a main body 22, which performs the movement of the pestle 16, and a moving body 23. In Fig. 14 these two components of the pestle are assembled and in Fig. 15 shown disassembled. Fig. 16 and Fig. Figures 17 show the main body 22 in different perspective views. Fig. 18 and Fig. Figures 19 show the moving body 23 in different perspective views.

[0079] The main body 22 has a bottom surface 24 facing the circuit substrate 18 and a top surface 25 opposite the bottom surface 24, and two recesses 26 laterally between the bottom surface 24 and the top surface 25. The moving element 23 is inserted into these recesses 26 and is rotatably mounted on a base 28 of the recess 26 opposite an opening 27 of the recess 26 about an axis of rotation 29 perpendicular to the intended direction of movement 46 of the main body 22.

[0080] The recess 26 defines a movement space 31 for the moving body 23 with an upper stop 32 on the side of the top 25 of the main body 22 and a lower stop 33 on the side of the bottom 24 of the main body 22, in which the moving body 23 is rotatable between the upper stop 32 and the lower stop 33.

[0081] The moving body 23 forms the guide profile 34 of the plunger 16. The guide profile 34 forms a projection 37, which is comparable to the projection 37 described above in the Fig. 11 to Fig. 13 shown embodiment of the guide profile 34 of the plunger 16. Furthermore, the guide profile 34 forms a recess 38 on the side of the projection 37 facing the underside 24 of the main body 22.

[0082] The moving body 23 has a top surface 40 and a bottom surface 41. In the illustrated embodiment, stop lugs 42 are attached and / or formed on the bottom surface 41. These could alternatively or additionally also be attached and / or formed on the top surface 40.

[0083] The movement sequence belonging to this variant of the plunger 16 with main body 22 and moving body 23 is exemplified with the plunger 16 being increasingly pressed into the housing 12 in the intended direction of movement, i.e. from the rest position of the plunger 16 towards the maximum actuation position, in Fig. 20 to Fig. 23 shown, from the resting position in Fig. 20 via two intermediate positions in Fig. 21 and Fig. 22 up to the maximum actuation position in Fig. 23.

[0084] In the rest position of the plunger 16, the moving body 23 rests against the lower stop 33 and the control cam 36 rests against the moving body 23 on a side of the recess 38 opposite the projection 37 (see Fig. 20). When the plunger 16 moves from its rest position towards its maximum actuation position, the moving body 23 is initially moved towards the upper stop 32, and the control cam 36 rests in the recess 38 against the moving body 23 (not shown in the figures). With further movement of the plunger 16, the moving body 23 initially rests against the upper stop 32, and the control cam 36 slides out of the recess 38 to the apex 39 of the projection 37 (see Fig. 21), against an increasing force of the return spring 45 of the auxiliary actuator 19, which requires an increasing force when actuating the plunger 16. In this process, the permanent magnet 48 is moved towards the fixing leg 20.

[0085] Subsequently, the control cam 36 passes the apex 39 of the projection 37. This causes the moving body 23 to be abruptly moved to the lower stop 33, generating a clanging noise. Simultaneously, the permanent magnet 48 undergoes an abrupt change in direction of movement, moving abruptly away from the fixing leg 20, across the circuit substrate 18, and relative to the magnetic field sensors 30 (see Fig. 22). Furthermore, the aforementioned force expenditure ceases after exceeding the apex 39 of the projection 37, so that exceeding the apex 39 of the projection 37 simultaneously causes a tactilely perceptible pressure point effect and a sudden change in direction of the movement of the permanent magnet 48 and thus a comparatively strong change in the magnetic field at the magnetic field sensors 30 and an impact noise from the moving body 23.

[0086] Finally, the plunger 16 is moved against the restoring force of the plunger spring 17 into the maximum actuation position ( Fig. 23).

[0087] Fig. 24 and Fig. 25 show a connection to the pestle 16 in Fig. 14 and Fig. 15 different variants of the pestle 16, Fig. 24 in a perspective view and Fig. 25 in a sectional view, cut from front left to back right in Fig. 24. The key difference to the pestle 16 in Fig. 14 and Fig. The advantage of point 15 lies in the fact that the moving body 23 is not rotatable here, but linearly displaceable on the main body 22. Thus, the plunger 16 also exhibits this characteristic. Fig. 24 and Fig. 25 a main body 22, which executes the movement of the plunger 16, and a moving body 23. The main body 22 has a surface corresponding to the circuit substrate 18 (in Fig. 24 and Fig. The moving body 23 is movably mounted on the main body 22, parallel to the intended direction of movement 46 of the main body 22, between an upper stop 32 on the side of the upper surface 25 of the main body 22 and a lower stop 33 on the side of the underside 24 of the main body 22, and thus linearly displaceable. The moving body 23 at least partially forms the guide profile 34 of the plunger 16, wherein the guide profile 34 forms a projection 37 in the area of ​​the moving body 23 and a recess 38 on the side of the projection 37 facing the underside 24 of the main body 22.

[0088] The movement sequence of the in Fig. 24 and Fig. The plunger shown in the key module (25) is comparable to the one in Fig. 20 to Fig. 23 with the pestle from Fig. 14 and Fig. The movement sequence is shown in Figure 15 and described above. In the rest position of the plunger 16, the moving body 23 rests against the lower stop 33, as also in Fig. 24 and Fig. 25 shown. The control cam 36 lies in or near the recess 38 or on a side of the recess 38 opposite the projection 37 against the moving body 23, wherein when the plunger 16 is moved from the rest position towards the maximum actuation position, the moving body 23 is first moved towards the upper stop 32 and the control cam 36 rests in the recess 38 against the moving body 23. As the plunger 16 moves further, the moving body 23 initially rests against the upper stop 32 and the control cam 36 slides out of the recess 38 to the apex 39 of the projection 37. Subsequently, the control cam 36 passes over the apex 39 of the projection 37. At this point, the moving body 23 is abruptly moved to the lower stop 33, generating a clanging sound, and the permanent magnet 48 is moved across the circuit substrate 18 and relative to the magnetic field sensor 30.

[0089] The auxiliary actuator 19 shown in the figures is a single-piece component. Alternatively, the auxiliary actuator 19 could also be composed of two or more components. In particular, the auxiliary actuator 19 could be a stamped metal part.

[0090] In the embodiments shown in the figures and described above, the two magnetic field sensors 30 are each a TMR sensor. The two magnetic field sensors 30 are arranged, perpendicular to the circuit substrate 18 in each intended movement position of the permanent magnet 48, on the north pole and south pole sides outside the permanent magnet 48. When the plunger 16 moves from its rest position to its maximum actuation position, the permanent magnet 48, perpendicular to the circuit substrate 18, passes the two magnetic field sensors 30 configured as TMR sensors.

[0091] This arrangement of the magnetic field sensors 30, designed as TMR sensors, in relation to the permanent magnet 48 is shown based on Fig. 26 explained. Fig. Figure 26 shows a schematic representation of a permanent magnet 48 in the form of a bar magnet with a north pole N and a south pole S. The magnetic field lines 47 of the permanent magnet 48 are shown. The direction of movement of the permanent magnet 48 perpendicular to its longitudinal axis, which extends between the north pole N and the south pole S, is indicated by two arrows. On the side of the north pole N and the south pole S, the relative movement of magnetic field sensors 30 to the permanent magnet 48 is indicated by a dashed line, where the distance X1 on the side of the south pole S is greater than the distance X2 on the side of the north pole N. The orientation of the magnetic field lines 47 at different positions of the magnetic field sensors 30, marked by small circles on the dashed lines, is indicated by dashes, where the length of the dashes symbolizes the magnetic field strength.It can be seen that at a larger distance X1, the magnetic field sensor 30 has to travel a significantly longer path Y1 to achieve the same change in orientation of the magnetic field lines 47 as at a smaller distance X2, where the magnetic field sensor 30 only has to travel the smaller path Y2 for the same change in orientation.

[0092] The considerations based on Fig. 26 leads to the conclusion that a magnetic field sensor 30 designed as a TMR sensor should ideally be placed near one of the poles of the permanent magnet 48, and this placement can be near either the north pole N or the south pole S. At the poles, both the strength of the magnetic field lines and the change in orientation (also: angular change) of the magnetic field lines 47 of the magnetic field are most pronounced. The total relative path between the permanent magnet 48 and the magnetic field sensor 30 can be determined by the distance from the respective magnetic pole, in Fig. 26. The distances X1 and X2 are determined. For greater distances from the magnetic pole, see distances X1 and X2 in... Fig. 26, the required distance increases, in Fig. 26 the path lengths Y1 and Y2 to achieve the same change in orientation (also: change in angle) of the magnetic field lines 47. This allows the desired required paths to be easily adjusted.

[0093] Alternatively, the magnetic field sensors 30 can also be Hall sensors.

[0094] In particular, the invention proposes a device for detecting a key press and / or the actuation path of a key module, in which the permanent magnet is not, as in known key modules, placed directly on the plunger as an actuator, but is mounted separately in the housing of the key module, in particular by means of an additional actuator. The movement of the permanent magnet is coupled to the movement of the plunger by means of a variable transmission mechanism, for example, a variable gear. This makes it possible both to determine an arbitrary motion transmission coefficient and to vary the motion transmission coefficient arbitrarily during actuation.

[0095] The keypad module is specifically designed for use with a TMR sensor as a magnetic field sensor. Using a Hall sensor as a magnetic field sensor is also possible.

[0096] When using a TMR sensor, the magnetic field lines of a permanent magnet in the form of a bar magnet are observed, see Fig. 26, an optimal linear motion component with the sensor positioned at one of the magnet's poles. The TMR sensor can be placed near either the north or south pole. Both the strength of the magnetic field lines and the angle of change are optimal at the poles. The total path of the permanent magnet can be determined by the distance of the TMR sensor from the respective magnetic pole, see Fig. 26. As the distance of the TMR sensor from the magnetic pole increases, the path of the permanent magnet also increases to achieve the same angular change in the magnetic field lines. Therefore, the path of the permanent magnet during movement can be adjusted by appropriately selecting its distance from the TMR sensor.

[0097] Simultaneously, the movement of the permanent magnet arranged on the auxiliary actuator can be rotary, pseudo-rotatory (rotational movement is simulated by elastic deformation of the auxiliary actuator, which is designed as a spring), or linear. While the plunger completes a linear vertical movement, the permanent magnet at the end of the auxiliary actuator moves horizontally or nearly horizontally (pendulum movement) in close proximity to the TMR sensor (or alternatively, the Hall sensor).

[0098] The keypad module essentially comprises a housing (preferably a two-part housing), a plunger for holding a keycap, an auxiliary actuator with an integrated or attached magnet, a plunger spring for resetting the plunger, and a circuit substrate (e.g., a printed circuit board) with at least one magnetic field sensor, such as a Hall sensor or TMR sensor. Depending on the application, the sensor can be mounted on the top or bottom of the circuit substrate or recessed within it.

[0099] The auxiliary actuator can be U-shaped and made of a resilient, non-magnetic material. For example, the auxiliary actuator is made of a copper alloy with spring properties. The permanent magnet is mounted in the housing on the control arm of the auxiliary actuator. The magnet is attached to the end of the control arm. At least one control cam, or for example, two control cams, can be located in a central section of the control arm. At least one guide contour can be formed on the plunger, for example, two guide contours if the auxiliary actuator has two control cams. When the plunger is actuated, the guide contour of the plunger corresponds to the associated control cam on the control arm of the auxiliary actuator. Depending on the contour of the control cam, the U-spring of the auxiliary actuator is compressed or released.The permanent magnet at the end of the control arm performs a pendulum movement predominantly in a horizontal plane near the magnetic field sensor (Hall sensor or TMR sensor).

[0100] In known keypad modules, the permanent magnet is moved perpendicular to the circuit substrate along with the magnetic field sensor (Hall sensor or TMR sensor). This results in a highly nonlinear displacement-signal relationship. In the device according to the invention, the permanent magnet is moved past the magnetic field sensor (Hall sensor or TMR sensor) in a predominantly horizontal plane. This creates an S-shaped signal-displacement characteristic, which exhibits significantly better linearity compared to the prior art. When using a Hall sensor, the magnet is moved to the position where the axis of the magnet is in line with the Hall sensor, or vice versa. The only difference between a Hall sensor and a TMR sensor lies in the initial position of the component relative to the magnet's position.

[0101] Additionally, placing the permanent magnet in the immediate vicinity of the magnetic field sensor with horizontal freedom of movement offers the following advantages: 1. The magnet and sensor are located inside the keyboard and cannot be easily affected by other magnetic fields from the outside. 2. Due to the proximity of the sensor, the magnetic field of the magnet can be significantly weaker. This allows the use of much smaller magnets or magnets made of inexpensive magnetic materials, such as ferrite magnets or even iron magnets. This reduces the overall system costs.

[0102] As mentioned above, the movement coupling between the plunger and the auxiliary actuator is achieved via the guide profile on the plunger. The contour of the guide profile can be designed as desired.

[0103] With an inclined contour (constant angle), the continuous movement of the plunger can be converted into a continuous horizontal movement of the magnet. The transmission ratio can be adjusted by the inclination of the slope, the lever ratio on the two arms of the auxiliary actuator, or the position of the pseudo-axis of rotation. In this case, the control arm of the auxiliary actuator rotates proportionally to the actuation movement of the plunger. The shape of the signal-path characteristic remains unchanged. Only the actuation path and the magnet's travel can be adjusted as desired.

[0104] At the same time, it is possible to design the guide profile on the plunger to be non-linear. This allows the S-shaped characteristic of a TMR sensor or the C-shaped characteristic of a Hall sensor to be compensated for and linearized accordingly.

[0105] Furthermore, the contour of the guide profile can be designed to create a progressive or a degressive signal path characteristic.

[0106] Simultaneously, it is possible to apply a snap contour to the plunger (tactile switch). Depending on the contour of the control cam, the lateral force of the auxiliary actuator's return spring results in varying resistance at the plunger. With the tactile switch, the actuation force increases until the apex of the guide profile's contour and then decreases. A pronounced pressure point effect is felt when the button module is actuated. The control arm of the auxiliary actuator, along with the magnet, moves just as abruptly, causing a sudden signal change. In any case, the pressure point and the sharp signal change are synchronized along the travel axis. The distance between the pressure point and the electrical switching point can be adjusted as desired by setting the switching threshold.

[0107] A click switch, i.e., with tactile and acoustic feedback, can be implemented similarly to a pressure point switch; however, the contour of the guide profile is not located directly on the plunger, but at least partially on a moving part of the plunger (clicker). The clicker can be mounted in the button module with linear or rotary movement.

[0108] Clicker pivot bearing: The clicker is rotatably attached to the plunger and can complete a rotational movement within a sector. When activated, the clicker rotates around its axis until it reaches its stop against the plunger, deflecting the auxiliary actuator with its magnet and generating a noticeable increase in force on the plunger. After passing the apex of the rotation, the clicker abruptly reverses direction until it reaches its stop against the plunger, producing an impact sound. Simultaneously, the control arm of the auxiliary actuator, with its magnet, abruptly rotates in the direction of the sensor, generating a significant signal change. This signal change is synchronized with the pressure point or click point, as in the tactile version.

[0109] Clicker linear bearing: The functionality is the same, however the clicker completes a linear movement in the U-shaped guide of the housing.

[0110] All switch variants are reset by means of a separate compression spring (plunger spring) which is located between the plunger and the housing.

[0111] The above functional description refers to an exemplary variant in which the control arm of the auxiliary actuator is elastically connected to the fixing arm via a U-shaped structure. The auxiliary actuator is made of an elastic, non-magnetic material. The auxiliary actuator also functions as a spring. The part can be stamped cost-effectively.

[0112] To improve the accuracy of the motion transmission, the U-shaped contour of the auxiliary actuator (transition area) can be mounted in contact with the inner wall of the housing (especially the upper part of the housing). This further restricts the movement of the auxiliary actuator. This contributes to the control arm with the magnet performing a pseudo-rotational movement, which further increases the accuracy of the keypad module. The design of the auxiliary actuator as a U-shaped spring minimizes overall friction and wear in the keypad module and increases its service life.

[0113] Regardless, the auxiliary actuator can be designed as a rotary-bearing component. The rotary bearing can be located in the lower or upper part of the housing.

[0114] The return spring can be integrated into the auxiliary actuator (e.g. as a leaf spring) or designed as a separate compression spring, tension spring, torsion spring or bending spring.

[0115] The auxiliary actuator can alternatively be made of, for example, a plastic part. The magnet can be injection-molded into the plastic or made from a magnetizable plastic.

[0116] The magnet can have any shape (cylindrical magnet, cuboid magnet, flat magnet, magnetic foil, etc.).

[0117] The magnet can be snapped, glued, welded, soldered, or attached to the auxiliary actuator using other methods. Alternatively, the auxiliary actuator can be made of a magnetizable material.

[0118] Typically, one magnetic field sensor (Hall sensor or TMR sensor) is sufficient per keypad. However, if required, two sensors can be placed on opposite magnetic poles per keypad. The sensors can operate in parallel, meaning that when the keypad is pressed, the signal increase is generated at both sensors (parallel connection to create redundancy or dual functionality). Alternatively, the sensors can be positioned and connected in opposite directions to implement a differential connection. In this case, when the keypad is pressed, the signal value at one sensor increases while the signal value at the other decreases. This allows for additional functions, particularly in gaming applications.

[0119] Another design variant can be implemented by attaching the guide profile to the auxiliary actuator and the control cam to the plunger.

[0120] In another variant, the auxiliary actuator can be mounted linearly movable within the housing along with the magnet. Horizontal displacement is achieved by the ramp or guide profile of the plunger.

[0121] In another variant, a permanent magnet, particularly a cylindrical magnet, can be mounted directly in the housing in a sliding or rolling manner and, for example, moved in a horizontal plane by means of a control cam of the plunger.

[0122] Another design allows the plunger movement to generate a rotational movement of the magnet within the housing. This application is particularly interesting in connection with TMR sensors.

[0123] To improve the illumination of the keycap, a light guide can be integrated into the cover, which homogenizes the illumination or specifically illuminates certain keycap areas more intensely.

[0124] In another version, the light guide can be attached to the housing of the keypad module as a separate part. Reference symbol list 10 Device 11-key module 12 cases 13 first housing part 14 second housing part 15 Motion transmission mechanism 16 pestles 17. Plunger spring for resetting the plunger 16. 18 Circuit substrate 19 additional actuators 20 Fixing legs of the auxiliary actuator 19 21 Control lever of the auxiliary actuator 19 22 Main body of the pestle 16 23 Moving body of the plunger 16 24 Underside of the main body 22 25 Top of the main body 22 26 Recess in the main body 22 27 Opening of the recess 26 28 Bottom of the recess 26 29 axis of rotation 30 Magnetic field sensor 31 Movement space in the recess 26 32 upper stop 33 lower stop 34 Piston guide profile 16 35 Tax profile of the tax leg 21 36 Tax cam of the tax profile 35 37 Advantage of the leadership profile 34 38 Trough of the guide profile 34 39 Peak of the lead 37 40 Top of the moving body 23 41 Underside of the moving body 23 42 impact studs 45 Return spring of the auxiliary actuator 19 46 intended direction of movement of the main body 22 47 Magnetic field lines of the permanent magnet 48 48 permanent magnets 49 keycap 50 Lighting 51 computing unit 52 Holder for permanent magnet 48 N North pole of the permanent magnet 48 S South pole of the permanent magnet 48 X1 Distance of the magnetic field sensor 30 from the south pole S X2 Distance of the magnetic field sensor 30 from the north pole N Y1 Distance traveled by the magnetic field sensor 30 at the south pole S Y2 Distance traveled by the magnetic field sensor 30 at the north pole N QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] CN 218 730 554 U

[0003] CN 208 241 649 U

[0003] CN 210 518 262

[0003]

Claims

[1] Device (10) for detecting a key press and / or a key travel of a key module (11) comprising a circuit substrate (18), a magnetic field sensor (30) arranged on or in the circuit substrate (18), a keypad module (11) attached to the circuit substrate (18) comprising a housing (12), a plunger (16), a plunger spring (17) for resetting the plunger (16) and a permanent magnet (48) cooperating with the magnetic field sensor (30), wherein the plunger (16) is movable relative to the housing (12) and perpendicular to the circuit substrate (18) between a rest position and a maximum actuation position, wherein the permanent magnet (48) is movable relative to the housing (12) and arranged such that a movement of the permanent magnet (48) causes a change in the magnetic field at the magnetic field sensor (30), wherein the permanent magnet (48) is coupled to the plunger (16) in such a way that the movement of the permanent magnet (48) originates from a movement of the plunger (16), so that the movement of the plunger (16) causes a change in the magnetic field at the magnetic field sensor (30) due to the coupled movement of the permanent magnet (48), wherein the magnetic field sensor (30) detects this change in the magnetic field and signals it to a computing unit (51) of the device (10), wherein the device (10) outputs at least one electrical signal to signal the actuation of the key and / or the actuation path of the key module (11) when the magnetic field changes, characterized by , that the permanent magnet (48) is mounted directly or indirectly on the housing (12) in such a way that the mobility of the permanent magnet (48) relative to the housing (12) has at least one movement component parallel to the circuit substrate (18). [2] Device (10) according to claim 1, characterized by , that the permanent magnet (48) is arranged in each intended movement position in the half of the housing (12) of the key module (11) facing the circuit substrate (18). [3] Device (10) according to any of the preceding claims, characterized by , that the permanent magnet (48) is a bar magnet in which the north pole and south pole are arranged along a longitudinal axis or transverse axis of the permanent magnet (48). [4] Device (10) according to claim 3, characterized by , that the longitudinal axis and / or the transverse axis and / or a magnetic field axis of the permanent magnet (48) runs parallel to the circuit substrate (18). [5] Device (10) according to claim 3 or 4, characterized by , that the longitudinal axis and / or the transverse axis and / or a magnetic field axis of the permanent magnet (48) runs perpendicular to a path of motion of the permanent magnet (48). [6] Device (10) according to any of the preceding claims, characterized by, that the magnetic field sensor (30) is arranged on a front side facing the keypad module (11) or on a rear side of the circuit substrate (18) facing away from the keypad module (11) or in the circuit substrate (18). [7] Device (10) according to any of the preceding claims, characterized by , that the magnetic field sensor (30) is a Hall sensor. [8] Device (10) according to claim 7, characterized by , that the Hall sensor and the permanent magnet (48) are arranged such that the change in the magnetic field at the Hall sensor caused by the movement of the permanent magnet (48) when the plunger (16) moves from its rest position to its maximum actuation position is an increase in the magnetic field strength. [9] Device (10) according to claim 7 or 8, characterized by, that a magnetic field axis of the permanent magnet (48), in a viewing direction perpendicular to the circuit substrate (18), extends through the area of ​​the Hall sensor in the maximum actuation position of the plunger (16). [10] Device (10) according to any one of claims 1 to 6, characterized by , that the magnetic field sensor (30) is a TMR sensor. [11] Device (10) according to claim 10, characterized by , that the TMR sensor, in the direction of view perpendicular to the circuit substrate (18), is arranged on the side of the north pole or the south pole in each intended movement position of the permanent magnet (48). [12] Device (10) according to claim 10 or 11, characterized by , that the permanent magnet (48), in a direction perpendicular to the circuit substrate (18), is moved past the TMR sensor from its rest position to its maximum actuation position when the plunger (16) is moved. [13] Device (10) according to any of the preceding claims, characterized by , that at least one further magnetic field sensor (30) is arranged on or in the circuit substrate (18) which interacts with the permanent magnet (48) in such a way that a movement of the permanent magnet (48) resulting from a movement of the plunger (16) also causes a change in the magnetic field at the at least one further magnetic field sensor (30) and the at least one further magnetic field sensor (30) also detects the change in the magnetic field and signals it to the computing unit of the device (10). [14] Device (10) according to any of the preceding claims, characterized by , that the coupling of the permanent magnet (48) to the plunger (16) comprises a motion transmission mechanism (15) which transmits the motion of the plunger (16) perpendicular to the circuit substrate (18) into the motion of the permanent magnet (48) with the motion component parallel to the circuit substrate (18). [15] Device (10) according to claim 14, characterized by , that the motion transmission mechanism (15) has an additional actuator (19) arranged in the key module (11), wherein the permanent magnet (48) is attached to and / or in the additional actuator (19) or integrated into the additional actuator (19) and is mounted on the housing (12) via the additional actuator (19). [16] Device (10) according to claim 15, characterized by , that the auxiliary actuator (19) has a fixing leg (20) and a control leg (21) which are connected to each other at one end of the legs (20, 21), wherein the auxiliary actuator (19) is fixed to the housing (12) by means of its fixing leg (20), wherein the permanent magnet (48) is attached to or near a free end of the control leg (21) on the control leg (21), and wherein the control leg (21) is coupled to the plunger (16) to transmit the movement of the plunger (16) into the movement of the permanent magnet (48). [17] Device (10) according to claim 16, characterized by , that in a side view the fixing leg (20) and the control leg (21) are connected to each other in a U-shape. [18] Device (10) according to claim 16 or 17, characterized by , that the coupling between plunger (16) and control arm (21) is effected by the control arm (21) bearing against the plunger (16), wherein the plunger (16) has a guide profile (34) which interacts with a control profile (35) of the control arm (21), wherein the control profile (35) of the control arm (21) slides along the guide profile (34) of the plunger (16) when the plunger (16) moves, thereby causing a movement of the control arm (21) relative to the fixing arm (20) and thus the movement of the permanent magnet (48) relative to the housing (12) with the movement component parallel to the circuit substrate (18). [19] Device (10) according to claim 18, characterized by, that the fixing leg (20) and the control leg (21) form a return spring (45) for the control leg (21) or that a return spring is integrated and / or arranged and / or attached to the control leg (21) and rests against the housing (12), wherein the return spring (45) is pre-tensioned and, due to its pre-tension, ensures that the control profile (35) of the control leg (21) rests against the guide profile (34) of the plunger (16). [20] Device (10) according to claim 18 or 19, characterized by , that the control profile (35) of the control arm (21) includes a control cam (36) which protrudes towards the guide profile (34) of the tappet (16). [21] Device (10) according to any one of claims 18 to 20, characterized by , that the transmission of the movement of the plunger (16) into the movement of the permanent magnet (48) is determined by the shape of the guide profile (34) of the plunger (16). [22] Device (10) according to claim 21, characterized by, that the guide profile (34) on the plunger (16) decreases at least section by section in the opposite direction to an intended actuation movement of the plunger (16), so that a constant plunger movement in the actuation direction as the control cam (36) slides along the constantly decreasing section of the guide profile (34) results in a constant speed of movement of the permanent magnet (48) away from the fixing leg (20), and / or that the guide profile (34) on the plunger (16) decreases at least section by section in a continuously weaker manner as the control cam (36) slides along the continuously weaker decreasing section of the guide profile (34), so that a constant plunger movement in the actuation direction as the control cam (36) slides along the continuously weaker decreasing section of the guide profile (34) results in a decreasing speed of movement of the permanent magnet (48) away from the fixing leg (20),and / or that the guide profile (34) on the plunger (16) increases at least section by section, contrary to an intended actuation movement of the plunger (16), so that a constant plunger movement in the actuation direction as the control cam (36) slides along the constantly increasing section of the guide profile (34) results in a constant speed of movement of the permanent magnet (48) towards the fixing leg (20), and / or that the guide profile (34) on the plunger (16) increases at least section by section, contrary to an intended actuation movement of the plunger (16), so that a constant plunger movement in the actuation direction as the control cam (36) slides along the continuously less increasing section of the guide profile (34) results in a decreasing speed of movement of the permanent magnet (48) towards the fixing leg (20). [23] Device (10) according to claim 21 or 22, characterized by, that the guide profile (34) on the plunger (16) forms a projection (37) so that, during a planned actuation movement of the plunger (16), the control cam (36) slides up to a vertex (39) of the projection (37) against an increasing force of the return spring (45), which requires an increasing force when actuating the plunger (16), which ceases after passing the vertex (39) of the projection (37), so that passing the vertex (39) of the projection (37) simultaneously causes a tactilely perceptible pressure point effect and a sudden change in the direction of movement of the permanent magnet (48). [24] Device (10) according to claim 23, characterized by, that the plunger (16) comprises a main body (22) which performs the movement of the plunger (16) and a moving body (23), wherein the main body (22) has a bottom surface (24) facing the circuit substrate (18) and a top surface (25) opposite the bottom surface (24) and has at least one recess (26) laterally between the bottom surface (24) and the top surface (25), into which the moving body (23) is inserted and is rotatably mounted on a base (28) of the recess (26) opposite an opening (27) of the recess (26) about an axis of rotation (29) perpendicular to the intended direction of movement (46) of the main body (22), wherein the recess (26) defines a movement space (31) for the moving body (23) with an upper stop (32) on the side of the top (25) of the main body (22) and a lower stop (33) on the side of the bottom (24) of the main body (22), in which the moving body (23) is rotatable between the upper stop (32) and the lower stop (33), wherein the moving body (23) at least partially forms the guide profile (34) of the plunger (16), wherein the guide profile (34) forms the projection (37) in the area of ​​the moving body (23) and a recess (38) on the side of the projection (37) facing the underside (24) of the main body (22), wherein in the rest position of the plunger (16) the moving body (23) rests against the lower stop (33) and the control cam (36) rests in or near the recess (38) or on a side of the recess (38) opposite the projection (37) on the moving body (23), wherein, when the plunger (16) moves from the rest position towards the maximum actuation position, the moving body (23) is initially moved towards the upper stop (32) and the control cam (36) rests in the recess (38) on the moving body (23), wherein, with further movement of the plunger (16), the moving body (23) initially rests against the upper stop (32) and the control cam (36) slides out of the recess (38) to the apex (39) of the projection (37) and subsequently the control cam (36) passes the apex (39) of the projection (37) and thereby abruptly moves the moving body (23) to the lower stop (33) and generates a stop noise and, at the same time, moves the permanent magnet (48) over the circuit substrate (18) and relative to the magnetic field sensor (30). [25] Device (10) according to claim 23, characterized by , that the plunger (16) has a main body (22) which performs the movement of the plunger (16) and a moving body (23), wherein the main body (22) has a bottom surface (24) facing the circuit substrate (18) and a top surface (25) opposite the bottom surface (24), wherein the moving body (23) is movably and thus linearly displaceable on the main body (22) between an upper stop (32) on the top side (25) of the main body (22) and a lower stop (33) on the bottom side (24) of the main body (22) parallel to the intended direction of movement (46) of the main body (22), wherein the moving body (23) at least partially forms the guide profile (34) of the plunger (16), wherein the guide profile (34) forms the projection (37) in the area of ​​the moving body (23) and a recess (38) on the side of the projection (37) facing the underside (24) of the main body (22), wherein in the rest position of the plunger (16) the moving body (23) rests against the lower stop (33) and the control cam (36) rests in or near the recess (38) or on a side of the recess (38) opposite the projection (37) on the moving body (23), wherein, when the plunger (16) moves from the rest position towards the maximum actuation position, the moving body (23) is initially moved towards the upper stop (32) and the control cam (36) rests in the recess (38) on the moving body (23), wherein, with further movement of the plunger (16), the moving body (23) initially rests against the upper stop (32) and the control cam (36) slides out of the recess (38) to the apex (39) of the projection (37) and subsequently the control cam (36) passes the apex (39) of the projection (37) and thereby abruptly moves the moving body (23) to the lower stop (33) and generates a stop noise and, at the same time, moves the permanent magnet (48) over the circuit substrate (18) and relative to the magnetic field sensor (30). [26] Device (10) according to claim 18 or 19, characterized by, that the guide profile (34) of the tappet (16) includes a sliding cam that protrudes towards the control profile (35) of the control arm (21). [27] Device (10) according to claim 26, characterized by , that the transmission of the movement of the plunger (16) into the movement of the permanent magnet (48) is determined by the shape of the control profile (35) of the control arm (21). [28] Device (10) according to any one of claims 15 to 27, characterized by , that the auxiliary actuator (19) is made of a spring-like and / or non-magnetic material and / or of metal and / or an alloy and / or plastic or at least partially comprises one or more of these materials. [29] Device (10) according to any of the preceding claims, characterized by, that the movement of the permanent magnet (48) is a rotational movement or a pseudo-rotational movement in a plane perpendicular or parallel to the circuit substrate (18) or a linear movement parallel to the circuit substrate (18). [30] Device (10) according to any of the preceding claims, characterized by , that the key module (11) has a light (50) or a light (50) is assigned to the key module (11), wherein the lighting (50) is mounted on and / or in the circuit substrate (18) such that it illuminates an associated keycap (49) with symbols and / or the housing (12) of the key module (11). [31] Device (10) according to claim 30, characterized by , that one or more light guides are integrated into the housing (12) of the keypad module (11) and / or arranged as separate components in the keypad module (11). [32] Keyboard comprising one or more devices (10) according to any of the preceding claims.

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