Sensor assembly with joystick or thumbstick

Abstract

To provide a sensor assembly for determining an orientation of a lever or a handle or a stick, e.g., a joystick or a thumb stick.SOLUTION: A sensor assembly (100) includes: a magnetic source (101) for generating a magnetic field; a lever or stick (102), which can be manually tilted about a reference orientation (112); and a magnetic sensor device (130) for measuring the magnetic field. The magnetic source (101) includes a central opening. The stick includes a ferromagnetic object (105) mounted such that a potential energy of the magnetic field is minimal when the stick is oriented in the reference orientation.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates generally to the field of magnetic sensors, and more particularly to a sensor assembly for measuring the orientation of a rotatable joystick or thumbstick. [Background technology]

[0002] Joystick or thumbstick assemblies are known in the art, for example from U.S. Patent No. 5,999,949, which describes a joystick assembly including a first magnet having north and south magnetic poles, a second magnet having north and south magnetic poles, and a sensor device located between the first and second magnets. A first end of a shaft is coupled to the second magnet such that movement of the shaft results in movement of the second magnet relative to the first magnet. The second magnet is attracted to the first magnet, resulting in a restoring force on the shaft.

[0003] A joystick assembly is also known from patent document 2, filed on June 18, 2021, which describes a sensor system and method for determining the position of a joystick in a manner that is highly robust against disturbance fields. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] U.S. Patent Application Publication No. 2019 / 179357 [Patent Document 2] European Patent Application No. 21180417.4 Summary of the Invention [Problem to be solved by the invention]

[0005] There is always room for improvement or alternatives.

[0006] It is an object of an embodiment of the present invention to provide a sensor assembly for determining the orientation of a lever or handle or stick, for example a joystick or thumbstick.

[0007] An object of an embodiment of the present invention is to provide a sensor assembly for determining the orientation (e.g., in the form of a single angle) of a lever or handle or stick that can be tilted or pivoted in one degree of freedom.

[0008] An object of an embodiment of the present invention is to provide a sensor assembly for determining the orientation (e.g., in the form of two angles) of a lever or handle or stick that can be tilted or swiveled in two degrees of freedom.

[0009] An object of an embodiment of the present invention is to provide a sensor assembly for determining the orientation (e.g., in the form of two angles) of a lever or handle or stick that can be tilted or pivoted in one or two degrees of freedom, and for determining whether the lever or handle or stick is pressed (i.e., depressed) or released.

[0010] It is an object of an embodiment of the present invention to provide a sensor assembly that has only a single magnet while still allowing the stick to return to a neutral position when released. [Means for solving the problem]

[0011] In some embodiments, an assembly is provided for determining said orientation in a manner that is highly robust against disturbance fields (also known as "stray fields").

[0012] These and other objects are achieved by embodiments of the present invention.

[0013] According to a first aspect, the present invention provides a sensor assembly comprising: a magnetic source for generating a magnetic field with circular or rotational symmetry (e.g., order 3 or 4 or 5 or 6 or 7 or 8) about a central axis defining a reference orientation (e.g., Z); a lever or stick, for example a joystick or thumbstick, mounted such that the lever or stick can be tilted relative to the reference orientation (also referred to herein as a "neutral orientation" or "neutral position"), the lever or stick including or fixedly connected to a ferromagnetic material; and a magnetic sensor device comprising a substrate having a plurality of magnetic sensors (e.g., a plurality of magnetic elements arranged, for example, as a 3D magnetic pixel or as four 2D magnetic pixels) configured to provide a sensor signal indicative of a magnetic field (generated by the magnetic source and altered by the ferromagnetic material), the magnetic sensor device being located between the magnetic source and the ferromagnetic material, and the lever or stick being mounted such that the potential energy of the magnetic field is minimum when the lever or stick is oriented in the reference orientation.

[0014] The lever or stick may also be referred to as a "handle."

[0015] The magnet or magnetic source exerts an attractive force on the ferromagnetic body. Due to the structure of the assembly, movement of the ferromagnetic body causes the lever or stick to tilt. The present invention takes advantage of the fact that the energy of the system is lowest when the ferromagnetic body is closest to the magnetic source, which corresponds to the stick or lever being oriented in a "reference orientation" (also referred to as a "neutral orientation" or "neutral position").

[0016] Simply put, this sensor assembly can be referred to as a "joystick assembly with neutral pull-back force."

[0017] In a preferred embodiment, the assembly includes only a single magnet.

[0018] Preferably, the potential energy increases (eg, strictly monotonically) when the ferromagnetic material is tilted away from a reference orientation.

[0019] Optionally, the assembly may also provide a "push button" function.

[0020] This position sensor assembly may also be referred to as a "joystick assembly" if the stick is a joystick, or a "thumbstick assembly" if the stick is a thumbstick.

[0021] In a preferred embodiment, the stick or lever has an elongated axis, which preferably coincides with the central axis of the magnet.

[0022] In one embodiment, the magnetic source is axially oriented penetration An axially magnetized magnet with an opening.

[0023] The through openings may have a circular cross section or a regular polygon, for example an equilateral triangle, square, pentagon, or hexagon, octagon, etc.

[0024] The magnet may be a two-pole ring magnet.

[0025] In one embodiment, the magnetic source is an axially magnetized ring magnet having a cylindrical opening therethrough.

[0026] In one embodiment, the magnetic source includes a plurality of individual two-pole magnets oriented in parallel and arranged to form an opening therebetween.

[0027] In other embodiments, the magnetic source includes at least two, or at least three, or at least four magnetic elements forming a central opening therebetween.

[0028] In one embodiment, the magnetic source includes a plurality of bar or beam magnets, for example, three or four or five or six or eight two-pole magnets.

[0029] In one embodiment, the magnetic sensor device is positioned such that the sensor element of the magnetic sensor device is located substantially on the central axis of the magnetic source and is located at an axial position (e.g., zA) where the axial magnetic field component (e.g., Bz) is equal to zero, or at a distance (e.g., ε) less than 1.0 mm, or less than 0.8 mm, or less than 0.5 mm from the axial position.

[0030] The advantage of such an assembly is that when the magnet is in the neutral position, the magnetic field component Bz measured by the sensor device is approximately equal to zero, which makes it possible to calculate the tilt angle in a simple way using simple formulas with good accuracy over a relatively large tilt range (at least ±15°, or at least ±20°, or at least ±25°).

[0031] In one embodiment, the ferromagnetic material includes or is made from iron.

[0032] In one embodiment, the ferromagnetic body has a shape with circular symmetry or rotational symmetry about an axis of symmetry. In a preferred embodiment, this axis of symmetry of the ferromagnetic body coincides with the longitudinal axis of the lever or stick, although this is not absolutely necessary. Preferably, the axis of rotational symmetry of the ferromagnetic body coincides with the axis of rotational symmetry of the magnet in the "neutral position" of the ferromagnetic body, and these axes form a non-zero angle in the "tilted" position of the ferromagnetic body.

[0033] In one embodiment, the ferromagnetic body has a prismatic or cubic shape with a square cross section in a plane perpendicular to the lever or stick.

[0034] In one embodiment, the ferromagnetic material has a circularly symmetric shape relative to the axis of the lever or stick.

[0035] In one embodiment, the ferromagnetic body has a generally cylindrical shape.

[0036] The overall cylindrical shape may further have an axially extending rim or flange that extends in the direction of the magnetic source.

[0037] Preferably, the radial size of the ferromagnetic body (e.g., outer diameter or diagonal of the outer periphery) is smaller than the radial size of the magnetic source (e.g., outer diameter or diagonal of the outer periphery). For example, if the ferromagnetic body has a cylindrical shape or includes a cylindrical, spherical, or hemispherical protrusion, and the magnet is a ring magnet, the outer diameter of the cylindrical, spherical, or hemispherical shape is preferably smaller than the outer diameter of the ring magnet.

[0038] In one embodiment, the ferromagnetic body has a cavity facing the magnetic source.

[0039] In one embodiment, the ferromagnetic body has a shape with ferromagnetic protrusions extending towards the magnetic source.

[0040] Examples are shown in Figures 11A to 14. The "ferromagnetic protrusion" can be connected to a larger object, such as a cylindrical or cubic object, the latter being ferromagnetic or non-ferromagnetic, made from, for example, plastic or aluminum. The shape of the ferromagnetic object or ferromagnetic protrusion is preferably rounded, for example hemispherical, although this is not absolutely necessary.

[0041] In one embodiment, the lever or stick, e.g., joystick, has a tilt range ranging from at least -25° to +25° about a neutral position in one plane (for one degree of freedom) or two orthogonal planes (for two degrees of freedom).

[0042] In one embodiment, the assembly further comprises a housing or retention mechanism (eg, a mechanism having one or more brackets) that allows for movable attachment of the stick and ferromagnetic material to the magnetic source.

[0043] In one embodiment, the housing or retention mechanism may have a protrusion and the ferromagnetic body may have a cavity or opening for at least partially receiving the protrusion, or vice versa.

[0044] The protrusions may be implemented as plastic or aluminum bosses.

[0045] In an embodiment, the ferromagnetic body has a convex shape that includes a rim or flange configured to rest on a portion of the housing or retention mechanism.

[0046] In one embodiment, the ferromagnetic material has a concave shape.

[0047] In one embodiment, the ferromagnetic body has a shape with a peripheral flange facing the magnetic source, and the housing or retaining mechanism further comprises a contact surface portion for supporting said peripheral flange. The contact surface may be ring-shaped.

[0048] When the stick is in its reference orientation, the peripheral flange of the ferromagnetic material may contact the surface at multiple locations (e.g., around the entire periphery), with the pivot point being closest to the magnetic source. When the stick is manually tilted relative to the reference orientation, the ferromagnetic material may contact the support surface on only one side, such that the axial location of the pivot point is further away from the magnetic source.

[0049] Or, simply stated, a ferromagnetic body is closest to the magnetic source when oriented in a reference orientation, with the peripheral flange (or rim) typically resting on a ring-shaped plane at this position, where the potential energy is minimum.

[0050] The ferromagnetic body is moved at a certain angle relative to the reference position. Tilt When the ferromagnetic material is in contact with the ring-shaped surface at one location, it does not contact the ring-shaped surface at another location, where the potential energy is not a minimum.

[0051] In one embodiment, the ferromagnetic material is pivotable about a pivot point (real or imaginary).

[0052] The pivot point may have a fixed position relative to the magnetic source.

[0053] In one embodiment, the pivot point may be urged toward or away from the magnetic source, for example, in a direction substantially parallel to the reference axis of the magnet.

[0054] In one embodiment, the ferromagnetic body has a cavity for accommodating a ferromagnetic ball, and the housing or retaining mechanism further comprises a non-flat surface (e.g., a spherical, ovoid, or parabolic surface) for supporting the ball and therefore also the ferromagnetic body and stick.

[0055] Preferably, the non-planar surface is shaped so that the distance between the magnetic source and the non-planar surface is minimum at the intersection of the reference axis with the non-planar surface. Or, stated in "simple terms," ​​the "lowest point" of the surface closest to the magnet is the location where the reference orientation (or reference axis) intersects with that surface.

[0056] In one embodiment, the ferromagnetic material has a spherical or hemispherical shape or protrusion.

[0057] In one embodiment, the housing or retention mechanism comprises a first housing portion that is fixed relative to the magnetic source and a second housing portion that is movable relative to the magnetic source, for example, between a first axial position and a second axial position.

[0058] The sensor device may be further configured to determine whether the pivot point is at the first axial position or the second axial position.

[0059] In one embodiment, push detection only needs to operate when the stick is in its neutral orientation, while in another embodiment, push detection also operates when the stick is tilted.

[0060] In one embodiment, the depression stroke is a value in the range of 0.2 to 2.0 mm, or in the range of 0.2 to 1.0 mm. 。

[0061] In one embodiment, the second housing portion is movable relative to the magnetic source by a spring or membrane and / or by a plurality of guide pens.

[0062] The spring may be a membrane spring or a disc spring or a Belleville spring made from a non-magnetic material. The stick is thus pushed back in the axial direction (Z) by this spring or membrane. In contrast, the force pushing (rotating) the stick back to the neutral orientation is magnetic. For any position of the pivot point, the potential energy (for rotation) is lowest in the neutral orientation.

[0063] The sensor device may further be configured to determine (directly or indirectly) whether the pivot point is at said first elevation or said second elevation.

[0064] In one embodiment, the sensor device is configured to determine two or three magnetic field components (e.g., Bx, By, Bz) oriented in three orthogonal directions and determine one or two tilt angles (e.g., α, β) based on these magnetic field components. The angle designations may be as shown in FIG. 1 or as shown in FIG. 15. These magnetic field components may be measured with a single sensor positioned at the central axis of the magnet.

[0065] In one embodiment, the sensor device is configured to determine at least two magnetic field components (e.g., Bx, By, Bz) oriented in at least two orthogonal directions and to determine at least one tilt angle (e.g., α) based on these magnetic field components.

[0066] In one embodiment, the sensor device is configured to determine at least three magnetic field components (e.g., Bx, By, Bz) oriented in three orthogonal directions and to determine one or two tilt angles (e.g., α, β) based on these magnetic field components.

[0067] In one embodiment, the sensor device has a sensor structure configured to determine two or three magnetic field components (e.g., Bx, By, Bz) oriented in three orthogonal directions, and a processing circuit configured to determine one or two tilt angles (e.g., α, β) based on these magnetic field components.

[0068] In one embodiment, the sensor device is configured to determine at least two or four magnetic field gradients (e.g., dBx / dx, dBy / dy, dBz / dx, dBz / dy) oriented in different directions and determine one or two tilt angles (e.g., α, β) based on the magnetic field gradients.

[0069] In one embodiment, the sensor device has a sensor structure configured to determine at least two or four magnetic field gradients (e.g., dBx / dx, dBy / dy, dBz / dx, dBz / dy) oriented in different directions, and has processing circuitry configured to determine one or two tilt angles (e.g., α, β) based on the magnetic field gradients.

[0070] By "determining the axial position" it is meant determining whether a stick (e.g., a joystick or thumbstick) is being pressed.

[0071] In one embodiment, the sensor device comprises at least one horizontal Hall element for measuring a first magnetic field component (e.g., Bz) in a first direction (e.g., Z) parallel to a reference orientation, at least one vertical Hall element for measuring a second magnetic field component (e.g., Bx) oriented in a second direction perpendicular to the first direction (e.g., Z), and optionally at least one vertical Hall element for measuring a third magnetic field component (e.g., By) oriented in a third direction perpendicular to the first direction (e.g., Z) and the second direction (e.g., X).

[0072] In one embodiment, the sensor device comprises an integrating magnetic flux concentrator (IMC) having a circular shape and at least two horizontal Hall elements located near the periphery of the IMC and spaced at 180° angular intervals, or at least three horizontal Hall elements located near the periphery of the IMC and spaced at multiples of 120° angular intervals, or at least four horizontal Hall elements located near the periphery of the IMC and spaced at multiples of 90° angular intervals.

[0073] In one embodiment, the plurality of magnetic sensors includes a first sensor (e.g., S1), a second sensor (e.g., S2), a third sensor (e.g., S3), and a fourth sensor (e.g., S4), wherein the first sensor is located at a first sensor position, the second sensor is located at a second sensor position, the first sensor and the second sensor are positioned on a first imaginary line oriented in a first direction (e.g., X) and spaced apart from each other by a first distance, the first sensor (e.g., S1) is configured to measure a first magnetic field component (e.g., Bx1) oriented in the first direction (e.g., X) and a second magnetic field component (e.g., Bz1) oriented in a third direction (e.g., Z), and the second sensor (e.g., S2) is configured to measure a third magnetic field component (e.g., Bx2) oriented in the first direction (e.g., X) and a fourth magnetic field component (e.g., Bz3) oriented in the third direction (e.g., Z). , Z), a third sensor (e.g., S3) is located at a third sensor position, and a fourth sensor (e.g., S4) is located at a fourth sensor position, the third sensor and the fourth sensor being positioned on a second imaginary line oriented in the second direction (Y) and spaced a second distance from each other, the third sensor (e.g., S3) is configured to measure a fifth magnetic field component (e.g., By1) oriented in the second direction (Y) and a sixth magnetic field component (e.g., Bz3) oriented in the third direction (e.g., Z), and the fourth sensor (S4) is configured to measure a seventh magnetic field component (e.g., By2) oriented in the first direction (e.g., X) and an eighth magnetic field component (e.g., Bz4) oriented in the third direction (e.g., Z).

[0074] Using such a configuration, the first magnetic field gradient (dBx / dx) may be based on the difference between the first magnetic field component (Bx1) and the third magnetic field component (Bx2), the second magnetic field gradient (dBz / dx) may be based on the difference between the second magnetic field component (Bz1) and the fourth magnetic field component (Bz2), the third magnetic field gradient (dBy / dy) may be based on the difference between the fifth magnetic field component (By1) and the seventh magnetic field component (By2), and the fourth magnetic field gradient (dBz / dy) may be based on the difference between the sixth magnetic field component (Bz3) and the eighth magnetic field component (Bz4).

[0075] In one embodiment, the sensor device is configured to measure and output measurements to enable an external processor to calculate orientation.

[0076] In one embodiment, the sensor device further comprises a processing circuit, e.g., a programmable processor, configured to determine, based on the sensor signal, a first angle (α) and optionally also a second angle (β) indicative of the orientation of the stick.

[0077] In one embodiment, the sensor device is configured to determine the first angle (e.g., α) using a function (e.g., an arctangent function) of the ratio between the first magnetic field component (e.g., Bz) and the second magnetic field component (e.g., By), or the sensor device is configured to determine the first angle (e.g., α) using an arctangent function of the ratio between the first magnetic field gradient (e.g., dBz / dx) and the second magnetic field gradient (e.g., dBy / dx), and optionally the sensor device is further configured to determine the second angle (e.g., β) using a function (e.g., an arctangent function) of the ratio between the first magnetic field component (e.g., Bz) and the third magnetic field component (e.g., Bx), or the sensor device is configured to determine the second angle (e.g., β) using an arctangent function of the ratio between the third magnetic field gradient (e.g., dBz / dy) and the fourth magnetic field gradient (e.g., dBy / dy).

[0078] In one embodiment, the sensor device is configured to determine a first angle (e.g., α) using a function of the ratio between a first magnetic field component (e.g., Bz) and a second magnetic field component (e.g., By), and optionally, the sensor device is further configured to determine a second angle (e.g., β) using a function of the ratio between the first magnetic field component (e.g., Bz) and a third magnetic field component (e.g., Bx).

[0079] In one embodiment, the sensor device is configured to determine the first angle (e.g., α) using an arctangent function of the ratio between the first magnetic field gradient (e.g., dBz / dx) and the second magnetic field gradient (e.g., dBy / dx), and optionally, the sensor device is configured to determine the second angle (e.g., β) using an arctangent function of the ratio between the third magnetic field gradient (e.g., dBz / dy) and the fourth magnetic field gradient (e.g., dBy / dy).

[0080] In one embodiment, the sensor device is further configured to determine the sum of the squares of at least two or at least three magnetic field components, and to compare this sum or a value derived from this sum (e.g., the square root of the sum) with a predetermined threshold, and to determine that the stick has been pressed or depressed if the sum or the value derived from the sum is greater than the threshold, and to determine that the stick has been released if the sum or the value derived from the sum is less than the threshold.

[0081] The magnetic source may be a ring magnet. The height of the ring magnet may be equal to or greater than the inner diameter. The height of the ring magnet is preferably less than the outer diameter of the ring magnet.

[0082] In one embodiment, the magnetic source is a ring magnet having an outer diameter (e.g., Do) in the range of 8 to 12 mm (e.g., equal to about 10 mm), an inner diameter (e.g., Di) in the range of 2.0 to 5.0 mm (e.g., equal to about 3 mm), and a height (e.g., H) of about 3.0 to about 5.0 mm (e.g., equal to about 4 mm).

[0083] In one embodiment, the sensor device comprises a semiconductor substrate positioned at a distance (eg, d5) in the range of 0.2 mm to 0.8 mm from the ring magnet.

[0084] Particular and preferred aspects of the invention are set out in the accompanying independent and dependent claims. Features from the dependent claims may be combined with features of the independent claims and with features of other dependent claims as appropriate and not merely as explicitly set out in the claims. These and other aspects of the invention will be apparent from and elucidated with reference to the embodiments described hereinafter. [Brief explanation of the drawings]

[0085] [Figure 1] FIG. 1 is a schematic diagram of an exemplary implementation of a joystick assembly according to an embodiment of the present invention, the assembly comprising a housing having a single ring magnet, a magnetic sensor device, a ferromagnetic body movable within the housing, and a joystick connected to the ferromagnetic body, the joystick of the assembly having three degrees of freedom (tilt in two orthogonal directions, and up and down), and the position and orientation of the joystick can be represented by two angle and height values. [Figure 2A] FIG. 2 is a simplified schematic diagram of a variation of the joystick assembly of FIG. 1 according to another embodiment of the present invention, in which the joystick can be tilted about a reference axis but vertical displacement (press or release) is not detected, and the ferromagnetic material has a cavity facing the magnetic source. [Figure 2B] FIG. 2 is a simplified schematic diagram of a variation of the joystick assembly of FIG. 1 according to another embodiment of the present invention, in which the joystick can be tilted about a reference axis but vertical displacement (press or release) is not detected, and the ferromagnetic material has a cavity facing the magnetic source. [Figure 2C]FIG. 2 is a simplified schematic diagram of a variation of the joystick assembly of FIG. 1 according to another embodiment of the present invention, in which the joystick can be tilted about a reference axis but vertical displacement (press or release) is not detected, and the ferromagnetic material has a cavity facing the magnetic source. [Figure 3A] 3A-3C show variations of the joystick assembly of FIGS. 2A-2C, in which the ferromagnetic body has a flat or planar bottom surface facing the magnet, and these figures also show possible locations of the center point of the bottom surface, which is closest to the magnet in FIG. 3B. [Figure 3B] 3A-3C show variations of the joystick assembly of FIGS. 2A-2C, in which the ferromagnetic body has a flat or planar bottom surface facing the magnet, and these figures also show possible locations of the center point of the bottom surface, which is closest to the magnet in FIG. 3B. [Figure 3C] 3A-3C show variations of the joystick assembly of FIGS. 2A-2C, in which the ferromagnetic body has a flat or planar bottom surface facing the magnet, and these figures also show possible locations of the center point of the bottom surface, which is closest to the magnet in FIG. 3B. [Figure 4] 2 is a cross-sectional view showing an exemplary embodiment of magnetic flux lines that may be generated by the ring magnet of FIG. 1 in a plane containing the central axis of the ring magnet, in the absence of a ferromagnetic body. [Figure 5] FIG. 1 shows an exemplary embodiment of how a magnetic field component Bz oriented in a reference orientation (Z) varies along the reference axis Z; as can be seen, the value of Bz is zero at point "A" at a given distance from the magnet. [Figure 6] 6A is a diagram showing an exemplary arrangement of a magnetic sensor device relative to a ring magnet that may be used in embodiments of the present invention; FIG. 6B is a close-up view of the ring magnet; and FIG. 6C is a diagram showing multiple bar magnets oriented and arranged in parallel to form a central opening to generate a magnetic field similar to that of FIG. 4, that may be used in embodiments of the present invention. [Figure 7]FIG. 1 illustrates a sensor structure with one horizontal and four vertical Hall sensors, in which the orientation of a joystick is determined based on magnetic field components, as may be used in an embodiment of the present invention. [Figure 8] FIG. 1 illustrates a sensor structure comprising a disk-shaped integrating magnetic concentrator (IMC) and four horizontal Hall elements positioned near the periphery of the disk and spaced at multiple 90° angular intervals, as may be used in an embodiment of the present invention in which the orientation of a joystick is determined based on magnetic field components. [Figure 9] FIG. 1 shows a semiconductor substrate having four sensors, each sensor comprising an integrating magnetic flux concentrator disk and two horizontal Hall elements positioned on opposite sides of the disk, as may be used in an embodiment of the present invention in which the orientation of a joystick is determined based on a magnetic field gradient. [Figure 10] FIG. 1 shows a semiconductor substrate having four sensors, each sensor comprising a horizontal Hall element and one or two vertical Hall elements, as may be used in an embodiment of the present invention in which the orientation of a joystick is determined based on a magnetic field gradient. [Figure 11A] FIG. 10 is a perspective view illustrating another example joystick assembly according to an embodiment of the present invention. [Figure 11B] 11A and 11B are side views of another example joystick assembly according to an embodiment of the present invention, which can be considered as a variation of the assembly of FIG. 1, or as a variation of the assembly of FIGS. 2A-2C, or as a variation of the assembly of FIGS. 3A-3C; in the assembly of FIGS. 11A and 11B, the joystick can pivot about a pivot point PP. [Figure 12] FIG. 11C shows another embodiment of the present invention, which can be thought of as a variation of the joystick assembly of FIG. 11B, in which the assembly comprises a ferromagnetic cube and a ferromagnetic hemisphere extending from the cube. [Figure 13]FIG. 13 shows another embodiment of the present invention, which can be thought of as a variation of the joystick assembly of FIG. 12, in which the assembly comprises a cylindrical stick and a ferromagnetic hemisphere attached to the end of the stick. [Figure 14] FIG. 14 shows another embodiment of the present invention, which can be thought of as a variation of the joystick assembly of FIG. 13, in which the assembly comprises a cylindrical stick and a ferromagnetic ball or sphere attached to the end of the stick. [Figure 15] FIG. 10 illustrates how the random orientation of the line segment [CP] can be represented by two angles α and β. DETAILED DESCRIPTION OF THE INVENTION

[0086] The drawings are only schematic and non-limiting. In the drawings, the size of some elements may be exaggerated for illustrative purposes and not drawn to scale. Any reference signs in the claims shall not be construed as limiting their scope. In different drawings, the same or similar reference signs (e.g., the same modulo 100) may refer to the same or similar elements.

[0087] The present invention will be described with respect to particular embodiments and with reference to certain drawings but the invention is not limited thereto but only by the claims.

[0088] The terms first, second, and the like in this specification and claims are used to distinguish between similar elements and are not necessarily used to describe any manner of order, whether temporal, spatial, sequential, or in any other way. The terms so used are interchangeable under appropriate circumstances, and it is understood that the embodiments of the invention described herein are capable of operating in orders other than those described or illustrated herein.

[0089] Terms such as upper, lower, and the like in this specification and claims are used for descriptive purposes and not necessarily to describe relative positions. The terms so used are interchangeable under appropriate circumstances, and it is understood that the embodiments of the invention described herein are capable of operation in orientations other than those described or illustrated herein.

[0090] It should be noted that the term "comprising" used in the claims should not be interpreted as being limited to the means listed thereafter, nor does it exclude other elements or steps. Thus, the term should be interpreted as specifying the presence of the stated features, integers, steps or components as referenced, but without excluding the presence or addition of one or more other features, integers, steps or components or groups thereof. Thus, the scope of the expression "a device comprising means A and B" should not be limited to a device consisting only of components A and B. This means that, in the context of the present invention, the relevant components of the device are only A and B.

[0091] Throughout this specification, the reference to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment is included in at least one embodiment of the present invention. Thus, the appearances of the phrase "in one embodiment" or "in an embodiment" in various places throughout this specification do not necessarily all refer to the same embodiment, but may. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments, as would be apparent to one of ordinary skill in the art from this disclosure.

[0092] Similarly, in describing exemplary embodiments of the invention, it should be understood that various features of the invention may be grouped together in a single embodiment, drawing, or description for the purpose of streamlining the disclosure to aid in understanding one or more of the various inventive aspects. This method of disclosure, however, is not to be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as the appended claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed embodiment. Accordingly, the claims appended hereto are expressly incorporated into the Detailed Description herein, with each claim standing on its own as a separate embodiment of the invention.

[0093] Furthermore, some embodiments described herein include some other features that are included in other embodiments, but not other features, and it is intended that combinations of features from different embodiments form different embodiments that are within the scope of the present invention, as understood by those skilled in the art. For example, in the appended claims, any of the claimed embodiments may be used in any combination.

[0094] In the description provided herein, numerous specific details are set forth. However, it will be understood that embodiments of the present invention may be practiced without these specific details. In other instances, well-known methods, structures, and techniques have not been shown in detail in order not to obscure an understanding of this description.

[0095] In this specification, unless expressly stated otherwise, the term "magnetic sensor device" or "sensor device" refers to a device including at least one "magnetic sensor" or at least one "magnetic sensor element" preferably integrated on a semiconductor substrate. The sensor device may be included in a package also called a "chip", but this is not essential.

[0096] As used herein, the terms "sensor element" or "magnetic sensor element" or "magnetic sensor" may refer to a component or group of components, or sub-circuit, or structure capable of measuring a magnetic quantity, such as, for example, a magnetoresistive (MR) element, a GMR element, an XMR element, a horizontal Hall plate, a vertical Hall plate, a Wheatstone bridge including at least one (but preferably four) magnetoresistive elements, or the like, or a combination thereof.

[0097] In certain embodiments of the present invention, the terms "magnetic sensor" or "magnetic sensor structure" may refer to a configuration comprising one or more integrating magnetic concentrators (IMCs), also known as integrating magnetic flux concentrators, for example, one or more horizontal Hall elements arranged near the periphery of the IMC, for example, a disk-shaped IMC having two horizontal Hall elements spaced 180° apart from each other, or four horizontal Hall elements spaced 90° apart from each other.

[0098] In this specification, the expressions "in-plane component of the magnetic field vector" and "projection of the magnetic field vector in the sensor plane" are synonymous. If the sensor device is or includes a semiconductor substrate, this also means "magnetic field component parallel to the semiconductor plane." These components can be labeled Bx and By.

[0099] In this specification, the expressions "out-of-plane component of a vector," "Z component of a vector," and "projection of a vector on an axis perpendicular to the sensor plane" are synonymous. This component may be labeled Bz.

[0100] Embodiments of the present invention are typically described using a Cartesian coordinate system having three axes X, Y, Z that are fixed relative to the sensor device, with the X and Y axes parallel to the substrate and the Z axis perpendicular to the substrate.

[0101] In this document, the expressions "spatial derivative" or "derivative" or "spatial gradient" or "gradient" are used synonymously. In the context of the present invention, gradient is typically determined as the difference between two values ​​measured at two positions spaced apart along a particular direction. In theory, gradient is typically calculated as the difference between two values ​​divided by the distance between the sensor positions, but in practice, this division by the distance is often omitted since the measurement signal needs to be scaled anyway.

[0102] In this application, horizontal Hall plates are typically referred to by H1, H2, etc., and signals from these horizontal Hall plates are typically referred to by h1, h2, etc., and vertical Hall plates are typically referred to by V1, V2, etc., and signals from these vertical Hall plates are typically referred to by v1, v2, etc.

[0103] In the context of the present invention, the expressions arctan(x / y), atan2(x,y), and arccot(y / x) are considered equivalent.

[0104] Known joystick assemblies, such as those described in U.S. Patent Application Publication No. 2019 / 179357(A1), may include two magnets and a sensor device located between the magnets. Other joystick assemblies, such as those described in U.S. Patent Application Publication No. 2019 / 179357(A1), include a single magnet that is movable relative to the sensor device.

[0105] The present invention relates to a sensor assembly for measuring the orientation of a lever or handle or stick, e.g., a joystick or thumbstick, further referred to as a "stick," which can be tilted (e.g., manually) relative to a reference orientation or pivoted away from the reference orientation. Upon release, the stick automatically re-orients itself to the reference orientation. In some embodiments, the stick can also be depressed (i.e., pushed down), and upon release, the stick automatically pushes back (upward).

[0106] In the sensor assemblies described below, the sensor device has a stationary position relative to the magnetic source, and the position and / or orientation of the joystick can be determined by measuring the characteristics of a magnetic field affected by a moving ferromagnetic material contained in or connected to the joystick.

[0107] Referring to the drawings:

[0108] Figure 1 shows a sensor assembly 100 that includes a magnetic source 101 for generating a magnetic field. In the example of Figure 1, the magnetic source is a single axially magnetized ring magnet 101 having a cylindrical through opening with a central axis 112, also referred to herein as the "reference axis" 112, that defines a "reference orientation."

[0109] The sensor assembly 100 further comprises a lever or stick 102 (e.g., a joystick or thumbstick) that is movably mounted to a housing or holder structure such that the lever or stick 102 can be tilted (e.g., manually) about a reference orientation (also referred to herein as a "neutral orientation" or "neutral position"). Hereinafter, for simplicity of explanation, this lever or handle or stick 102 will be further referred to as a "joystick."

[0110] The sensor assembly 100 further comprises a magnetic sensor device 130 comprising a semiconductor substrate having a plurality of magnetic sensors configured to provide sensor signals. The sensor device 130 may be configured to output these sensor signals or signals derived therefrom (e.g., after digitization and / or scaling). The sensor device may further comprise processing circuitry configured to determine the orientation of the joystick, for example, in the form of two angle values ​​(φ, ψ) as shown in FIG. 1 or two angle values ​​(α, β) as shown in FIG. 15, and may be configured to output these angle values. Optionally, the sensor device may be further configured to determine whether the lever is pressed (i.e., released), for example, in the form of a Boolean or binary value.

[0111] The sensor assembly 100 further comprises a ferromagnetic body 105 fixedly connected to the joystick. In the example of Figure 1, the ferromagnetic body 105 has the shape of a nut, but this is not essential and other shapes such as a donut shape, a cylindrical shape, a toroidal shape, a disk shape, etc. The purpose of the ferromagnetic body 105 is to bend the magnetic flux lines of the magnetic field generated by the magnetic source 101 when the joystick is moved (e.g., turned and / or pressed).

[0112] The sensor device 130 is positioned between the magnetic source 101 and the ferromagnetic material 105. The sensor device 130 is preferably positioned with respect to the magnetic source 101 such that the semiconductor substrate is located a predetermined distance d5 (see FIGS. 4 and 5 ) from the magnetic source at which, in the absence of the ferromagnetic material 105, the magnetic field on the reference axis Z is substantially equal to zero, as further discussed in FIGS. 4 and 5 . Or in other words, the magnetic sensor device 130 is preferably positioned such that the center position of the sensor element is substantially on the central axis 112 of the magnet 101 and is located at or near the axial position ZA at which the axial magnetic field component Bz is equal to zero, e.g., deviating from position ZA by up to 1.0 mm in either direction or by up to 0.5 mm. While this is not absolutely necessary for the invention to function, the mathematical formula for determining the angular orientation of the stick may be simpler and / or the formula may provide improved accuracy over a given range and / or may provide improved linearity over the range.

[0113] According to an important aspect of the present invention, lever or stick 102 having ferromagnetic material 105 is mounted so that the potential energy of the magnetic field is minimum when stick 102 is oriented in a "reference orientation" defined by the magnetic source, e.g., parallel to the Z axis, and increases as stick 102 is tilted away from reference orientation 112. In the embodiment of Figure 1, the potential energy refinement increases strictly monotonically as the tilt angle φ or ψ increases.

[0114] The ferromagnetic body 105 may have a cavity 107 for receiving at least a portion of a protrusion 106 of a housing or holder structure. If present, the cavity and protrusion may help the stick maintain a centered position within the housing or holding structure, although this is not absolutely required for the invention to function, as will be further illustrated (see, e.g., Figures 3B, 11B, 12, 13).

[0115] In some embodiments of the present invention, joystick 102 can be tilted in two orthogonal directions, and sensor device 130 is configured to determine (e.g., calculate) the orientation of the stick (e.g., as indicated by angles φ, ψ) based on measurements of the magnetic field, for example as described in Figures 7-10.

[0116] In the embodiment of FIG. 1, the sensor device 130 can also determine whether the stick 102 is being pressed (i.e., whether it is being pressed towards the magnet), although this is not necessary in all embodiments.

[0117] In the joystick assembly 100 shown in FIG. 1 , the joystick 102 can be tilted about a reference axis 112, but can also be pressed, for example, when in a reference orientation. For this purpose, the housing can comprise two housing parts 121, 122 that are movable relative to each other. In the exemplary embodiment of FIG. 1 , the housing comprises a first housing part 121 and a second housing part 122 that is movable relative to the first housing part 121 in the Z direction (parallel to the reference orientation). Such movement can be established or facilitated in any known manner, for example, by providing a plurality of guide pins 120 (two of which are visible in FIG. 1 ) in the first housing part 121 and a plurality of openings in the second housing part 122 through which these guide pins can slide, or vice versa.

[0118] The housing may further comprise a spring, e.g., a membrane spring 123, a disk spring, or a helical spring, configured to push the second housing portion 122 away from the first housing portion 121. When the stick 102 is in its neutral position (i.e., oriented in a reference orientation) and is manually pressed, the spring 123 is compressed, and the ferromagnetic material 105 is moved closer toward the magnetic source 101. The sensor device 130 can detect that the stick is pressed by analyzing the sensor signal, for example, by calculating the sum of the squares of the magnetic field components Bx, By, and Bz, comparing this sum with a predetermined threshold T1, and determining whether the stick is pressed or not depending on whether the sum is smaller or larger than the predetermined threshold T1. However, other formulas may also be used, for example, by testing whether the value of the magnetic field component Bz oriented in the reference orientation 112 is smaller or larger than a predetermined threshold T2, which may be a positive or negative value depending on the implementation.

[0119] It is an advantage of the sensor assembly 100 of Figure 1 that it can determine the orientation of the stick and provide a "restoring" or "pushing back" force without the need for two magnets (cost advantage).

[0120] Note that the magnet 101 is magnetized in only one direction relative to the reference orientation (e.g., the direction of the positive Z axis). For example, the magnetic source may have a north pole at its top and a south pole at its bottom (or vice versa). However, the stick 102 is automatically pulled back to its "reference orientation" parallel to the axis 112 by the magnetic force exerted by the magnetic source 101 on the ferromagnetic material 105.

[0121] The lever or stick may be mounted in any known manner, for example, as shown in FIG. 2 on page 6 / 66 of the data sheet for the ML90378 Triaxis® Position Processor, Revision 001, November 28, 2018, which is publicly available on the internet at the time of this application, which shows a "ball and socket joystick" configuration (on the left side of the figure) and a so-called "gimbal joystick" configuration (on the right side of the figure), although other mounting techniques may also be used. In FIG. 1, the ferromagnetic portion rests or is supported by a surface portion 124 of the housing. This principle is further illustrated in FIGS. 2A-3C.

[0122] These are the main principles of the present invention, and many different implementations using these principles are possible, some of which are described in more detail below.

[0123] 2A-2C are simplified schematic diagrams of a sensor assembly 200, which can be considered a variation of the sensor assembly 100 of FIG. 1. In the sensor assembly 200, the joystick 202 can be tilted (e.g., manually) about the reference axis 212, but cannot be moved up and down along the Z axis, and therefore the housing 224 need not comprise two housing portions that are movable relative to one another. Only a small portion of the housing is shown in FIG. 2. The housing portion 224 is not ferromagnetic and may comprise, for example, plastic or aluminum.

[0124] 2A-2C are primarily intended to illustrate that the attractive force acting between the magnet 201 and the ferromagnetic material 205 has a force component F that tends to return the stick 202 to the reference orientation. In FIG. 2A, the ferromagnetic body 205 is placed on the housing part on the left side of FIG. 2A, so that the attractive force F tends to rotate the stick 202 in a clockwise direction towards the reference axis 212, In FIG. 2B, the ferromagnetic body is mounted on the housing part 222 on both the left and right sides of FIG. 2B, so that the attractive force F tends to maintain the orientation of the stick 202 parallel to the reference orientation 212; 2C, the ferromagnetic body 205 is mounted on the housing part 222 on the right side of FIG. 2C, so that the attractive force F tends to rotate the stick 202 counterclockwise towards the reference axis 212.

[0125] It can be seen that when the ferromagnetic body 205 is closest to the magnet 201, i.e. in FIG. 2B, the distance d2 between the magnet 201 and the reference point AA (indicated by the black circle) of the ferromagnetic body 205 is smallest in FIG. 2B, and therefore the potential energy of this magnetic system is smallest.

[0126] The housing 224 of the joystick assembly 200 does not have a protrusion, even though the ferromagnetic material 205 of the joystick assembly 200 has a cavity 207. The cavity 207 may help to avoid sudden displacement when tilting the joystick outward from the neutral position.

[0127] Figures 3A-3C show a joystick assembly 300 which can be considered as a variation of the joystick assembly 200 of Figures 2A-2C, the main difference being that the ferromagnetic body 305 has a flat or planar bottom surface facing the magnet 301 and which does not have a cavity or protrusions.

[0128] These figures also show the possible movement of point BB, located at the center of the bottom surface, when the joystick 302 is tilted. As shown in FIG. 3B, this position is at the bottom of the cone or cone-like shape, which corresponds to the lowest potential energy. In FIG. 3A, point BB "moves away" with respect to the attractive force exerted by the magnet (compared to its position in FIG. 3B), so this position on the cone corresponds to a higher potential energy. It can also be seen that for very small angles φ and / or ψ, the movement of point BB (at the tip of the cone) is vertically upward, which indicates that a pulling force is already present for very small tilt angles.

[0129] Note that the joystick and ferromagnet are shown slightly displaced upward in FIGS. 3A and 3C for illustrative purposes, i.e., to better illustrate that ferromagnet 305 is at point "pp1" where it contacts bottom portion 324, and point BB represents the arc of a circle as tilt angle φ (for example) varies from 0° (neutral position in FIG. 3B ) counterclockwise to approximately 15° ( FIG. 3A ). Similarly, in FIG. 3C , ferromagnet 305 is at point "pp2" where it contacts bottom portion 324, and point BB represents the arc of a circle as tilt angle φ varies from 0° (neutral position in FIG. 3B ) counterclockwise to approximately 15° ( FIG. 3C ). Those skilled in the art will understand that point BB may occupy any position within the "cone," depending on tilt angles φ and ψ, and that at any of these positions, a magnetic force is applied to the stick to pull the stick back to the "default position," i.e., move point BB toward the tip of the "cone" ( FIG. 3B ).

[0130] Figure 4 shows an illustrative example of magnetic flux lines that may be generated by an axially magnetized ring magnet in cross section, in a plane containing the central axis Z of the ring magnet, in the absence of any ferromagnetic material. While the ring magnet in Figure 4 has a rectangular cross section, this is not absolutely necessary; for example, a rectangular cross section with rounded edges would also work.

[0131] The main purpose of Figure 4 is to show that the magnetic field generated by the magnet is substantially equal to zero at a predetermined position "zA" along the central axis Z, at a predetermined distance d5 from the magnet. This predetermined distance d5 depends on the dimensions of the magnet (inner diameter, outer diameter, height), but once one skilled in the art is informed that such a position exists, this position can be easily found by simulation and / or by performing simple experiments on a ring magnet with given dimensions.

[0132] As mentioned above, in a preferred embodiment of the present invention, the sensor device (not shown in FIG. 4) is preferably positioned at a certain distance from the magnet, such that the sensor element of the sensor device is located at this predetermined distance. However, it is pointed out that the present invention still works if the sensor element is not positioned exactly at this position. It has been found that it is sufficient for the sensor element to be close to the point zA, for example at a distance of up to 1.0 mm, or at a distance of up to 0.5 mm.

[0133] Figure 5 shows an illustrative example of how the magnetic field component Bz oriented in the reference direction Z typically varies along the reference axis Z of an axially magnetized two-pole ring magnet. This is a qualitative graph. As can be seen, the value of Bz is zero when the z coordinate is equal to zA, which corresponds to point "zA" in Figure 4. Since By = 0 and Bx = 0 at all points along the Z axis, this means that the magnitude |B| of the magnetic field generated by the magnet is zero at location zA.

[0134] When a ferromagnetic object (not shown in Figure 4) is brought near a magnetic source, it disrupts the field lines of Figure 4. In accordance with the principles of the present invention, the position of the ferromagnetic object, and therefore the orientation of the stick, can be determined by measuring the characteristics of the "disturbing magnetic field" at the sensor location.

[0135] 6A shows an example placement of a magnetic sensor device 630 relative to magnet 601. In this example, the sensor device is a packaged semiconductor device mounted directly on top of ring magnet 601. Sensor device 630 preferably comprises a semiconductor substrate having an "active surface" located substantially on the Z axis and at position zA described above, or at a distance of up to 1.0 mm or up to 0.5 mm from the position where the magnetic field |B| generated by magnet 601 in the absence of a ferromagnetic material is zero.

[0136] FIG. 6B shows that magnetic source 601 may be a single ring magnet having an outer diameter Do, an inner diameter Di, and a height H. The outer diameter Do may be a value in the range of 8 to 12 mm, e.g., a value equal to approximately 10 mm. The inner diameter Di may be a value in the range of 2.0 to 5.0 mm, e.g., a value equal to approximately 3 mm. The height H may be a value in the range of 3.0 to 5.0 mm, e.g., a value equal to approximately 4 mm. The value of d5 for a ring magnet with Do = approximately 10 mm, Di = approximately 3 mm, and H = approximately 4 mm may be a value in the range of approximately 0.2 mm to approximately 0.6 mm, e.g., a value equal to approximately 0.4 mm. Having been informed, as described above, that there exists a position along the Z axis where the magnetic field generated by the magnet is zero, one skilled in the art can easily find this position for magnets having other dimensions.

[0137] However, the present invention is not limited to assemblies including ring magnets; the same effect of generating a two-pole magnetic field with field lines that look similar to those in FIG. 4 (i.e., circularly symmetric about an axis and zero at a predetermined distance from the magnet or magnetic structure) can also be achieved by a magnetic structure 640 including multiple bar magnets, as shown in FIG. 6C , for example. The bar magnets are parallel-oriented, pointing in the same direction (upward in this example), and arranged to form a central opening to generate a magnetic field with field lines similar to those in FIG. 4. The magnetic field generated by these bar magnets is not 100% circularly symmetric, although 100% circular symmetry is not absolutely necessary. From this example, it can be seen that a cube magnet with a cylindrical cutout, or a prismatic magnet (e.g., with a polygonal cross section, such as a hexagon, octagon, etc.) and a cube magnet with a central cutout (circular, square, hexagon, etc.) would also work.

[0138] FIG. 7 illustrates a magnetic sensor structure that may be used in the sensor devices 130, 230, 330, 630, 1130, 1230, 1330, and 1430 of the sensor assemblies described herein. This magnetic sensor structure may be referred to as a 3D magnetic pixel. This sensor structure includes one horizontal Hall element H1 and four vertical Hall sensors V1-V4, all preferably integrated within a semiconductor substrate. This magnetic sensor structure 750 is capable of measuring three orthogonal magnetic field components: Bx and By, which are parallel to the semiconductor substrate, and Bz, which is perpendicular to the semiconductor substrate. The horizontal Hall element H1 provides a signal h1 proportional to Bz. Because the signal obtained from the Hall element must be scaled anyway, this can be expressed as Bz = h1 if the scaling factor is omitted from the equation.

[0139] The signals v1 and v3 from the vertical Hall elements V1 and V3, whose axes of sensitivity are most sensitive in the X direction, can be added or averaged to obtain the value of Bx. Again, if the scaling factor is omitted, we can use Bx = (v1 + v3). The sum of signals v1 and v3 corresponds to the magnetic field signal Bx at the position of the horizontal Hall element H1, even though the vertical Hall elements are slightly displaced (typically only about 25-45 μm). In fact, we could also use Bx = v1 (in which case V3 could be omitted) or Bx = v3 (in which case V1 could be omitted), but the sum (v1 + v3) better represents the value Bx at the same position as H1.

[0140] Similarly, the signals v2 and v4 obtained from the vertical Hall elements V2 and V4, which have their most sensitive axes oriented in the Y direction, can be added or averaged to obtain the value of By. If the scaling factor is omitted, By = (v2 + v4). In fact, we could also have By = v2 (in which case V4 could be omitted) or By = v4 (in which case V2 could be omitted), but the sum (v2 + v4) better represents the value By at the same location as H1 and has an improved signal-to-noise ratio (SNR).

[0141] 7 (not shown), the structure has only H1, V1, and V2, and sensor elements V3 and V4 are omitted. Such a structure can also measure essentially three orthogonal magnetic field components Bx, By, Bz at the position of H1, with an improved signal-to-noise ratio (SNR).

[0142] The horizontal Hall element typically has an area of ​​about 15 μm×15 μm to about 25 μm×25 μm, for example, an area equal to about 20 μm×20 μm. The vertical Hall element is positioned adjacent to the horizontal Hall element H1. The entire structure of FIG. 7 is preferably smaller than 60 μm×60 μm.

[0143] The orientation of the stick can be derived from the magnetic field values ​​Bx, By, Bz measured by the 3D pixels. For example, the angles α and β (as defined in FIG. 15) can be derived from the ratio of two or more of these values, for example as the arctangent of the ratio.

[0144] When the sensor structure 700 of FIG. 7 is used in a sensor assembly in which the stick is also movable in the Z direction, such as the sensor assembly of FIG. 1, the sensor device 130 detects three magnetic field components Bx, By, and B zBy calculating the sum of squares of Bz and comparing this sum of squares with a predetermined threshold, it can be determined whether the stick is pressed (or not). If the sum of squares is greater than the threshold, this means that the stick is pressed. If the sum of squares is less than the predetermined threshold, this means that the stick is released, or vice versa. In fact, referring back to FIGS. 4 and 5, to ensure that the sum of squares is clearly different in the "pressed" and "released" states, it may be preferable to ensure that the value of Bz in the released state is zero or slightly negative, rather than ensuring that the sensor device is in a position on the Z axis where the value of Bz is slightly positive. This may help to clearly distinguish between the "pressed" and "released" states. The predetermined threshold may be determined, for example, during design or a calibration procedure, or may be hard-coded or written into the non-volatile memory (e.g., flash memory or eeprom) of the sensor device.

[0145] In embodiments where the stick can only be pressed when oriented in a neutral position, i.e., when Bx=0 and By=0, the sensor device can simply compare the value of Bz with a predetermined threshold and determine that the stick is pressed if the value of Bz is greater than the threshold, and that the stick is released if the value of Bz is less than the threshold, or vice versa.

[0146] FIG. 8 illustrates another magnetic sensor structure 850 that can be used in the sensor devices 130, 230, 330, 630, 1130, 1230, 1330, and 1430 of the sensor assemblies described herein. This structure 850 may also be referred to as a 3D magnetic pixel and may be considered a variation of structure 750 of FIG. 7, providing the same functionality. The sensor structure 850 of FIG. 8 includes a disk-shaped integrating magnetic concentrator (IMC) and four horizontal Hall elements H1-H4 positioned near the periphery of the disk and spaced at multiple 90° angular intervals. If the scaling factors are omitted from the equations (as described above), the value of Bx can be calculated as (h2-h1), the value of By can be calculated as (h4-h3), and the value of Bz can be calculated as (h1+h2), (h3+h4), or (h1+h2+h3+h4). The latter values ​​have an improved signal-to-noise ratio (SNR). The orientation of the stick can be derived from the values ​​of the magnetic fields Bx, By, Bz measured by the 3D pixels, preferably calculated as a function of the ratio of two or more of these values, for example as an arctangent function of the ratio, using, for example, the formula shown in Figure 15. In embodiments where the stick can only be pressed when oriented in a neutral position, i.e., when Bx = 0 and By = 0, the sensor device can simply compare the value of Bz to a predetermined threshold and determine that the stick is pressed if the value of Bz is greater than the threshold and that the stick is released if the value of Bz is lower than the threshold, or vice versa.

[0147] Figures 7 and 8 show two examples of sensor structures 750, 850 that can be used to determine the orientation of a stick, and optionally the axial position of the stick (i.e. whether the stick is pressed or released), based on one or more magnetic field components, although the invention is not limited thereto and it is also possible to determine the orientation based on magnetic field gradients, as will be explained below.

[0148] 9 shows another magnetic sensor structure 950 that may be used in the sensor devices 130, 230, 330, 630, 1130, 1230, 1330, 1430 of the sensor assemblies described herein. This sensor structure 950 is preferably integrated in a semiconductor substrate and comprises four sensors S1-S4, each a 2D magnetic pixel comprising an integrated magnetic concentrator (IMC) disk and two horizontal Hall elements located on opposite sides of the disk, in either the X or Y axis passing through the center of the structure.

[0149] The sensor S1 provides two signals h1 and h2 for calculating Bx1 and Bz1.

[0150] Sensor S2 provides two signals h3 and h4 for calculating Bx2 and Bz2.

[0151] Sensor S3 provides two signals h5 and h6 for calculating By3 and Bz3.

[0152] Sensor S4 provides two signals h7 and h8 for calculating By4 and Bz4.

[0153] From the signals Bx1, Bz1, Bx2, Bz2, the two magnetic field gradients can be determined, namely: gr1=(dBx / dx)=Bx2-Bx1=(h4-h3)-(h2-h1) gr2=(dBz / dx)=Bz2-Bz1=(h4+h3)-(h2+h1)

[0154] From the signals By3, Bz3, By4, Bz4, two magnetic field gradients can be determined, namely: gr3=(dBy / dy)=By4-By3=(h8-h7)-(h6-h5) gr4=(dBz / dy)=Bz4-Bz3=(h8+h7)-(h6+h5)

[0155] The orientation of the joystick may be determined as a function of these gradients, for example, using the following set of equations as an example:

number

number

[0156] It is advantageous to determine the stick orientation by the magnetic field gradient (as opposed to the magnetic field component) because the resulting angle value is largely independent of the disturbance field.

[0157] Optionally, the values ​​of α and β thus calculated are further processed in a post-processing unit, as known in the art, e.g., to improve linearity, e.g., by using a look-up table containing a plurality of reference points and interpolating (e.g., linearly interpolating) between these reference points.

[0158] FIG. 10 illustrates another magnetic sensor structure 1050 that can be used in the sensor devices 130, 230, 330, 630, 1130, 1230, 1330, and 1430 of the sensor assemblies described herein. This sensor structure 1050 can be thought of as a variation of structure 950 of FIG. 9, providing the same functionality. The sensor structure of FIG. 10 includes four sensors S1-S4, each of which is a 2D magnetic pixel and includes a horizontal Hall element and one vertical Hall element located adjacent to the horizontal Hall element, or one horizontal Hall element and two vertical Hall elements located on opposite sides of the horizontal Hall element. Again, sensor S1 can measure (Bx1, Bz1), sensor S2 can measure (Bx2, Bz2), sensor S3 can measure (By3, Bz3), and sensor S4 can measure (By4, Bz4). From these eight magnetic field values, four gradient values, gr1, gr2, gr3, and gr4, can be derived using the formulas shown in Figure 10. Two angle values ​​can then be calculated from these four gradient values, preferably as a function of the ratio of the gradient values, for example as an arctangent function of the ratio of the magnetic field gradients.

[0159] 10, each sensor S1-S4 includes two vertical Hall elements, and the signals from these vertical Hall elements are summed or averaged. For example, the value Bx1 can be calculated as (v1 + v1'), Bx2 = (v2 + v2'), Bz3 = (v3 + v3'), and Bz4 = (v4 + v4'). From these values, the four slopes can be determined using the following equations: gr1=(dBx / dx)=Bx2-Bx1=(v2+v2')-(v1+v1') gr2=(dBz / dx)=Bz2-Bz1=(h2-h1) gr3=(dBx / dy)=Bx4-Bx3=(v4+v4')-(v3+v3') gr4=(dBz / dy)=Bz4-Bz3=(h4-h3) From these four gradients, the two angles α and β can be calculated, for example, using the same formulas as shown in FIG.

[0160] In a variant not explicitly shown, the sensor device has a 3D magnetic pixel as shown in FIG. 7 or 8 located at a central position, and four 2D magnetic pixels S1-S4 as shown in FIG. 9 or 10. This allows the angular position of the stick to be calculated in two independent ways, thus providing error detection capabilities. It also allows the detection of whether the stick is pressed (or not) and allows the angle to be determined in a manner that is very insensitive to disturbance fields. Furthermore, if each 2D pixel has two vertical Hall elements instead of just one, accuracy can be further improved by improving the signal-to-noise ratio (SNR) of the sensor signal.

[0161] 11A and 11B show, in perspective and side views, respectively, an example of another joystick assembly 1100. This assembly 1100 can be thought of as a variation of the assembly 100 of FIG. 1, or as a variation of the assembly 200 of FIGS. 2A-2C.

[0162] The main differences between assembly 1100 of FIG. 11A and assembly 100 of FIG. 1 are that (i) in assembly 1100, joystick 1102 can pivot about a (stationary) pivot point PP rather than a portion of the stick contacting the housing, and (ii) ferromagnetic body 1105 has a ferromagnetic protrusion, which may be rounded or hemispherical, connected to the stick and extending to its underside (facing magnet 1101). While the protrusion may be integrally formed with a larger ferromagnetic body, which in the example of FIG. 11 is a cylinder, the invention also works if the cylinder is non-ferromagnetic, for example, made of plastic or aluminum. In this case, the rounded or hemispherical body 1108 is actually the ferromagnetic body. It may be connected to the stick and / or non-ferromagnetic body in any known manner, for example, using an adhesive or using a screw thread.

[0163] 11, but not shown separately to limit the number of figures, the cylindrical body 1105 (which may be ferromagnetic or non-ferromagnetic) has a cavity 1107 for accommodating a ferromagnetic ball 1108 separate from the cylindrical body, and the housing further comprises a supporting curved surface 1109 to prevent the ball from contacting the semiconductor device. The ball may be arranged to roll on the curved surface 1109.

[0164] 11, but not shown separately to limit the number of figures, a cylindrical body 1105 (which may be ferromagnetic or non-ferromagnetic) has a cavity 1107 for accommodating a ferromagnetic ball 1108, which is glued to the cylindrical body. In this case, no supporting curved surface 1109 is required.

[0165] 1-3C are also applicable here. For example, the magnetic source 1101 may be a ring magnet (e.g., an axially magnetized two-pole ring magnet) or a structure including multiple bar magnets (e.g., as shown in FIG. 6C). The magnetic source defines a "reference orientation" 1012, also referred to as a "reference axis" Z, and the sensor device 1130 is positioned between the magnetic source 1101 and the ferromagnetic material 1108. When the ferromagnetic material 1108 is located on the reference axis and / or when the stick 1102 is oriented in the reference orientation, the potential energy of the magnetic system is minimum. When the stick 1102 is manually tilted away from this neutral position, the magnetic source 1101 exerts a force on the ferromagnetic material 1108 that tends to move it back toward the reference axis.

[0166] The sensor device 1130 may comprise a number of sensors capable of measuring one or more magnetic field components and / or magnetic field gradients, e.g., as described in Figures 7-10, from which the orientation of the stick 1102 may be calculated. The sensor device may be arranged to output the measurements or values ​​derived therefrom, e.g., gradients, sums of squares, ratios, or functions of ratios. The sensor device may comprise processing circuitry configured to determine, e.g., calculate, one or two angles, such as α and β having the meanings shown in Figure 15, or φ and ψ having the meanings shown in Figure 1.

[0167] Furthermore, if the stick 1102 is vertically movable, for example when the assembly comprises a housing (not shown in FIG. 11A) having a first housing portion that is stationary relative to the magnet 1101 and a second housing portion that is movable relative to the magnet 1101, it is also possible to determine whether the stick (e.g., joystick or thumbstick) is being pressed. Such a housing may further comprise a membrane spring and multiple guide pens, for example similar to FIG. 1. The housing may further comprise a "ball and socket" joint to allow the stick to pivot.

[0168] 12 shows another joystick assembly 1200 that can be considered a variation of the joystick assembly 1100 of FIG. 11B, the main difference being that the assembly 1200 comprises a ferromagnetic or non-ferromagnetic cube 1220 and a ferromagnetic ball 1205 or hemisphere or rounded object extending from the cube, attached to it (e.g., by gluing or using a screw thread), or integrally formed with it. In the latter case, the cube 1205 and the ball 1205 or sphere or partial sphere (e.g., hemisphere) or rounded object comprise a ferromagnetic material. In the example shown in FIG. 12, the cube has a cross-section (in a plane perpendicular to the Z axis) with a diagonal larger than the diameter of the ball or partial sphere, although this is not absolutely necessary.

[0169] In a variation of FIG. 12 (not shown), the diagonal of cube 1220 in cross section (in a plane perpendicular to the Z axis) is smaller than the diameter of ball 1205 .

[0170] In yet another variation of FIG. 12, the ferromagnetic or non-ferromagnetic body 1220 is a cylinder having a larger or smaller diameter than the stick 1202 .

[0171] Figure 13 shows another joystick assembly 1300, which can be considered as another variation of the joystick assembly 1200 of Figure 12, which includes a cylindrical stick and a ferromagnetic body in the form of a hemisphere attached to the end of the stick, but does not have a cube. The hemisphere is a diameter substantially equal to the diameter of the stick 1302 have .

[0172] Figure 14 shows a variation of the joystick assembly 1400 of Figure 13, in which the ferromagnetic material 1405 is a ball or has a generally spherical shape that is directly connected to the stick, for example using adhesive or threads. The diameter of the ball is larger, for example at least 20% larger, than the cross-sectional diameter of the cylindrical stick 1402. The stick 1402 may include a ferromagnetic material, but is preferably made from a plastic material.

[0173] FIG. 15 illustrates how to define the orientation of a fixed-length vector [CP] that originates from a reference point "C" and terminates at a point "P" on an imaginary sphere. While the vector [CP] is not shown, a first orthogonal projection [CA] of the vector [CP] onto the plane XZ is shown, and a second orthogonal projection [CB] of the vector [CP] onto the plane YZ is shown. The orientation of axis A, which passes through points C and P, can also be defined by a first angle α between the positive X-axis and vector [CA], and a second angle β between the positive Y-axis and vector [CB]. As an example, when the magnet axis is oriented perpendicular to the plane XY (i.e., perpendicular to the semiconductor substrate), also referred to as the "neutral position," then α = 90° and β = 90°. This corresponds to the orientation where φ = 0° and ψ = 0° described above. The following formula applies: Bx = B*cos(α)*sin(β) [1] By=B*cos(β)*sin(α) [2] Bz=B*sin(β)*sin(α) [3] By dividing [3] and [1] we get: (Bz / Bx)=tan(α) [4] (Bz / By)=tan(β) [5] where Bx is the magnetic field component oriented in the X direction, By is the magnetic field component oriented in the Y direction, Bz is the magnetic field component oriented in the Z direction, and B is the magnitude of the magnetic field vector.

[0174] In preferred embodiments, the angles α and β are within the range of 90°±30°, or within the range of 90°±40°, or within the range of 90°±50°, or within the range of 90°±60°.

Claims

1. 1. A sensor assembly (100; 200; 300; 1100; 1200; 1300; 1400) comprising: The sensor assembly includes: A magnetic source (101; 201; 301; 1101; 1201; 1301; 1401) that generates a magnetic field that is rotationally symmetric or circularly symmetric about a central axis that defines a reference direction (Z); Ferromagnetic materials (105; 205; 305; 1105, 1108; 1205; 1305; 1405), a lever or stick (102; 202; 302; 1102; 1202; 1302; 1402) mounted so as to be tiltable relative to the reference direction (Z), the lever or stick including the ferromagnetic material or being fixedly connected to the ferromagnetic material; a magnetic sensor device (130; 230; 330; 1130; 1230; 1330; 1430) including a substrate having a plurality of magnetic sensors configured to provide a sensor signal indicative of a magnetic field; the magnetic sensor device is disposed between the magnetic source and the ferromagnetic material; A sensor assembly (100; 200; 300; 1100; 1200; 1300; 1400) in which the lever or stick is mounted such that the potential energy of the magnetic field is minimized when the lever or stick is oriented in the reference orientation (Z), the sensor assembly includes only a single magnet; the magnetic source is an axially magnetized magnet having an axially oriented through opening; Sensor assembly (100; 200; 300; 1100; 1200; 1300; 1400).

2. the magnetic sensor device is arranged such that the plurality of sensor elements are located at an axial position (ZA) where an axial magnetic field component (Bz) is zero, or at a distance (ε) less than 1.0 mm, less than 0.8 mm, or less than 0.5 mm from the axial position; 2. A sensor assembly (100; 200; 300; 1100; 1200; 1300; 1400) according to claim 1.

3. the ferromagnetic body has a cavity facing the magnetic source; the ferromagnetic body has a rounded shape or a shape with ferromagnetic protrusions extending toward the magnetic source; A sensor assembly (100; 200; 300; 1100; 1200; 1300; 1400) according to claim 1 or 2.

4. the sensor assembly further comprising a housing or retention mechanism that provides a movable attachment of the stick and the ferromagnetic material relative to the magnetic source; A sensor assembly (100; 200; 300; 1100; 1200; 1300; 1400) according to claim 1 or 2.

5. the ferromagnetic body (105; 205; 305) has a shape with a peripheral flange oriented towards the magnetic source (101; 201; 301), The housing or the retaining mechanism further comprises a contact surface portion (224) for supporting the peripheral flange. A sensor assembly (100; 200; 300) according to claim 4.

6. The ferromagnetic body is rotatable around a pivot point (pp). A sensor assembly (1100; 1200; 1300; 1400) according to claim 1 or 2.

7. The housing or the holding mechanism has a first housing part (121) fixed relative to the magnetic source (101) and a second housing part (122) movable relative to the magnetic source (101). The sensor assembly (100) of claim 4.

8. the magnetic sensor device is configured to determine two or three magnetic field components (Bx, By, Bz) oriented in two or three orthogonal directions, respectively, and to determine one or two tilt angles (α, β) based on the magnetic field components; 3. A sensor assembly according to claim 1 or 2.

9. the magnetic sensor device is configured to determine two or four magnetic field gradients (dBx / dx, dBy / dy, dBz / dx, dBz / dy) oriented in different directions and to determine one or two tilt angles (α, β) based on the magnetic field gradients; The sensor assembly of claim 8 .

10. (A) having at least one horizontal Hall element for measuring a first magnetic field component (Bz) in a first direction (Z) parallel to the reference orientation, and at least one vertical Hall element for measuring a second magnetic field component (Bx) in a second direction perpendicular to the first direction (Z); (B) an integrating magnetic concentrator (IMC) having a circular shape, and at least two horizontal Hall elements (H1, H2) located near the periphery of the IMC and spaced apart at angles of 180°, or at least three horizontal Hall elements located near the periphery of the IMC and spaced apart at angles that are multiples of 120°, or at least four horizontal Hall elements (H1, H2, H3, H4) located near the periphery of the IMC and spaced apart at angles that are multiples of 90°; (C) The plurality of magnetic sensors includes a first sensor (S1), a second sensor (S2), a third sensor (S3), and a fourth sensor (S4), and the first sensor (S1) arranged at a first sensor position and the second sensor (S2) arranged at a second sensor position are located on a first virtual line facing the first direction (X) and are spaced apart from each other by a first distance, and the first sensor (S1) is configured to measure a first magnetic field component (Bx1) facing the first direction (X) and a second magnetic field component (Bz1) facing a third direction (Z), and the second sensor (S2) is configured to measure a third magnetic field component (Bx2) facing the first direction (X) and a fourth magnetic field component (Bz3) facing the third direction (Z). a third sensor (S3) arranged at a third sensor position and a fourth sensor (S4) arranged at a fourth sensor position are located on a second imaginary line oriented in the second direction (Y) and are spaced a second distance from each other, the third sensor (S3) being configured to measure a fifth magnetic field component (By1) directed in the second direction (Y) and a sixth magnetic field component (Bz3) directed in the third direction (Z), and the fourth sensor (S4) being configured to measure a seventh magnetic field component (By2) directed in the first direction (X) and an eighth magnetic field component (Bz4) directed in the third direction (Z); is one of The sensor assembly of claim 8 .

11. configured to determine the first angle (α) using a function of a ratio of a first magnetic field component (Bz) to a second magnetic field component (By); the magnetic sensor device is configured to determine a first angle (α) using an arctangent function of a ratio of a first magnetic field gradient (dBz / dx) to a second magnetic field gradient (dBy / dx); is one of The sensor assembly of claim 8 .

12. the magnetic sensor device is further configured to determine the sum of the squares of the two or three magnetic field components (Bx, By, Bz) oriented in the two or three orthogonal directions, respectively, and to compare said sum or a value obtained from said sum with a predetermined threshold value; If the sum or a value derived from the sum is greater than the threshold value, it is determined that the stick is pressed, and if the sum or a value derived from the sum is less than the threshold value, it is determined that the stick is released. The sensor assembly of claim 8 .

13. the magnetic source is a ring magnet having an outer diameter (Do) in the range of 8 to 12 mm, an inner diameter (Di) in the range of 2.0 to 5.0 mm, and a height (H) in the range of 3.0 to 5.0 mm; A sensor assembly (100; 200; 1000) according to claim 1 or 2.

14. the magnetic sensor device (130; 230; 1030) comprises a semiconductor substrate located at a distance (d5) in the range of 0.2 mm to 0.8 mm from the ring magnet; A sensor assembly (100; 200; 1000) according to claim 13.

15. In the case where the magnetic field measuring device has at least one horizontal Hall element for measuring a first magnetic field component (Bz) in a first direction (Z) parallel to the reference orientation and at least one vertical Hall element for measuring a second magnetic field component (Bx) in a second direction perpendicular to the first direction (Z), the magnetic field measuring device further includes at least one vertical Hall element for measuring a third magnetic field component (By) orthogonal to a third direction perpendicular to the first direction (Z) and the second direction (X), A sensor assembly (100; 200; 1000) according to claim 10.

16. configured to determine the second angle (β) using a function of the ratio of the first magnetic field component (Bz) to the third magnetic field component (Bx); configured to determine the second angle (β) using an arctangent function of the ratio of the third magnetic field gradient (dBz / dy) to the fourth magnetic field gradient (dBy / dy); A sensor assembly (100; 200; 1000) according to claim 11.

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