Hall sensor - magnet geometries for large stroke linear position sensing

Abstract

Position sensing units (PSUs) that include one or more magnets having one or more respective magnetic polarizations (MPs) and respective dead zones (DZ) between two MPs, and a magnetic flux measuring device (MFMD), the MFMD configured to measure a magnetic flux B, wherein the one or more magnets are operational to move relatively to the MFMD along a first direction within a linear range L that fulfils 1mm ≤ L ≤ 25mm, wherein the MFMD is positioned at a distance D away from the one or more magnets the magnet along a second direction perpendicular to the first direction, wherein the DZ forms an angle α with an axis parallel to a third direction perpendicular to the first and the second direction, and wherein α = 10 - 80 degrees.

Description

[0001]HALL SENSOR - MAGNET GEOMETRIES FOR LARGE STROKE LINEAR POSITION SENSING CROSS REFERENCE TO RELATED APPLICATIONS This application is related to and claims priority from US Provisional Patent Applications 63 / 441,451 and 63 / 441,452 filed January 27, 2023, 63 / 482,351 filed January 31, 2023, 63 / 444,402 filed February 9, 2023, and 63 / 491,554 filed March 23, 2023, all of which are incorporated herein by reference in their entirety. FIELD Embodiments disclosed herein relate in general to position sensing units, and in particular to position sensing in compact digital cameras included in mobile electronic devices. TERM ABBREVIATIONS ABBREVIATION DEFINITION / MEANING MA Magnet assembly MFMD Magnetic flux measuring device MFMDA Magnetic flux measuring device assembly S Stroke (used interchangeably with linear range) L Linear range (used interchangeably with stroke) SL Slope MPD Magnet polarization domain MP Magnet polarization DZ Dead zone B Magnetic flux density PSU Position sensing unit CA Coil assembly BACKGROUND Many compact digital cameras integrated in handheld mobile electronic devices (“mobile devices”) such as smartphones or tablets use actuators such as voice coil motors (VCMs) or stepper motors, e.g. for actuating a camera lens along a trajectory having a particular direction and range (stroke S” or linear range “L). In the following, stroke S and linear range L are used interchangeably. The actuation is controlled by a position sensing unit (PSU), which is typically based on a magnet or on a magnet assembly (MA) that moves relative to a magnetic flux measuring device (MFMD), for example a Hall sensor. For stable control, the PSU must support two conditions: a) it must exhibit linear behavior, i.e. its slope (SL) SL = ΔB / Δx must be constant along the entire stroke, where ΔB is the change in magnetic flux density (B) between two points located at a distance Δx from each other; and b) the slope SL = ΔB / Δx within stroke S must be sufficiently steep, i.e. it must be above a certain threshold, e.g. SL ≥ 10mT / mm, SL ≥ 50mT / mm or SL ≥ 250mT / mm or even or SL ≥ 2500mT / mm. Multi-aperture digital cameras (or multi-cameras) are standard in current mobile devices. A multi-camera may include a Wide camera that acts as the mobile device’s main (or “primary”) camera, an Ultrawide (UW) camera and a Tele (T) camera. The Main (or Wide) camera has a Wide camera sensor and a Wide camera field-of-view (FOVW) of about 65-95 degrees (about 20mm – 35mm 35eq.FL), the UW camera has as a UW camera sensor and a UW camera FOV (FOVUW>FOVW) of about 105-130 degrees (about 10mm – 16mm 35eq.FL), and the T camera has as a T camera sensor and a T camera FOV (FOVT<FOVW) of about 5-60 degrees (about 45mm – 300mm 35eq.FL). A lens used in one of these cameras may have an effective focal length (EFL) in the range of 2mm - 50mm, or 3mm - 30mm. An image sensor used in one of these cameras may have a (full) image sensor diagonal (SD) in the range of 2mm - 25mm, or 5mm - 20mm, e.g.16mm (1” sensor), 12mm (1 / 1.33” sensor) or 5.3mm (1 / 3” sensor), etc. FIG.1A shows a first example of a known PSU 100 and comprising a magnet 102 in a side view. Magnet 102 has a first magnet polarization domain (MPD) 104, a second MPD 105, a magnet width W102 (measured along the x-axis), a magnet height H102 (measured along the y-axis) and a magnet center C (with respect to the x direction or just “with respect to x”) located at a symmetry axis (SA) 108 (with respect to the y direction or just “with respect to y”) of magnet 102, and a MFMD 106. The magnet polarization (MP) of first MPD 104 and second MPD 105 respectively is parallel to a z-axis (i.e. perpendicular to the x-y-coordinate system shown) and anti-parallel to the z-axis (see FIG.1B). Magnet 102 has a “polarization border zone” or simply “dead zone” (DZ) 110 between first MPD 104 and second MPD 105. DZ 110 represents a plane that is oriented parallel to the y-z-axes (FIGS. 1A-B), i.e. DZ 110 forms an angle of zero degrees with the y-axis. DZ 110 extends to both sides of magnet center C. A width of DZ 110 is marked DZW. In general, DZW may be in the range 0.1mm – 0.5mm. This holds for all DZWs herein. Magnet 102 causes a magnetic field 112 in its surroundings. MFMD 106 is located at a distance D from magnet 102 measured along the z-axis, i.e. perpendicular to the x-y coordinate system shown (see FIG. 1B). When sensing the relative position between magnet 102 and MFMD 106, magnet 102 moves substantially parallel to the x direction and relative to MFMD 106. MFMD 106 does not move. The position of magnet 102 changes within the stroke, which is limited by x0 and xmax. That is, the length L1A of the stroke of PSU 100 is given by L1A = xmax - x0, and its direction is substantially parallel to the x-axis. For position sensing magnet 102 moves within the stroke only. This applies to all PSUs shown herein. x0and xmax, represent upper and lower limits (or borders) of stroke L1A and can be defined by a distance from DZ 110. Exemplarily and for simplicity, here we assume that x0 and xmax are respectively located at a distance W102 / 2 from the center of DZ 110, as shown. In graph 114, the magnetic flux density (B) measured by MFMD 106 is shown versus the position of magnet 102 along the x-axis. B is a function of x, i.e. B = B(x). Within stroke L1A, slope SL1A = (Bmax- B0) / L1A of B is linear. FIG. 1B shows PSU 100 in a top view. Magnet 102 has a magnet length L102 (measured along the z-axis). Here and exemplarily, L102 = ½ H102. MFMD 106 is located at a constant distance D (measured along the z axis) from magnet 102. FIG.1C shows a second example of a known PSU numbered 120 and comprising a magnet 122 in a side view. Magnet 122 has a homogenous MP 124 which is oriented parallel to the x-axis, a magnet width W122, a magnet height H122 and a magnet center C located at symmetry axis SA 128, and a MFMD 126. Magnet 122 causes a magnetic field 162. MFMD 126 is located at a distance D from magnet 122, wherein D is measured along a z-axis (see FIG.1D). The position of magnet 122 changes within the stroke, an upper and lower limit of stroke (L1C) can be defined by a distance from SA 128. Exemplarily and for simplicity, here we assume that x0 and xmax are respectively located at a distance W122 / 2 from SA 128, as shown. In graph 114, magnetic flux density B measured by MFMD 126 is shown versus the position of magnet 122 along the x-axis. Within stroke L1C, slope SL1C = (Bmax - B0) / L1C of B is linear. In some examples, W102 and W122 may be both in the range 0.5mm-5mm, L1A and L1C may be both in the range 0.25mm-1mm. In a typical example for focusing a camera lens, D=200μm and L1A, L1C=700μm, so that a ratio of L1A, L1C and D is L1A / D=3.5 and L1C / D=3.5. For many actuator sensing examples, SL1A and SL1C are sufficiently steep. However, L1A / D and L1C / D is relatively small. FIG.1D shows PSU 120 in a top view. Here and exemplarily, magnet length L122 is half of H122. FIG. 1E shows a third known example of a PSU 150 comprising a MA 152 and a MFMD 154. MA 152 includes a first rectangular magnet 156 having a first MP 158 and a second rectangular magnet 160 having a second MP 162 (anti-parallel to first MP 158). MA 152 has a width W152, a height H152, a C located at SA 164 and causes a magnetic field 166. MFMD 154 is located at a constant distance D=DCfrom MA 152, which may be DC=0.1mm-2mm. For position sensing, MA 152 moves along a stroke from x0to xmaxin the x direction and relative to MFMD 154. D is substantially constant between x0 and xmax, i.e. D is not a function of x. In graph 168, B measured by MFMD 154 is shown versus the x position of MA 152. Within stroke L, SL = (Bmax - B0) / L of B is linear. In some examples, W152 may be 0.5mm-10mm, L may be 0.25mm-1mm. In a typical position sensing example in a focusing actuator for a camera lens, D=200μm and L=700μm, so that a ratio of L and D is L / D=3.5. L / D is relatively small. FIG.1F shows a fourth known example of a PSU 170 comprising a MA 172 and a MFMD 174. MA 172 includes a first rectangular magnet 176 having a first MP 178, a second rectangular magnet 180 having a second MP 182 and a third rectangular magnet 184 having a third MP 186. First MP 178 and third MP 186 are anti-parallel, second MP 182 is perpendicular to first MP 178 and third MP 186. MA 172 has a width W172 and a height H172. MFMD 174 is located at a distance D away from MA 172. C is located at SA 188 of MA 172. MA 172 causes a magnetic field 189. For position sensing, MA 172 moves along stroke L in the x direction relative to MFMD 174. D is not constant between x0and xmax, but it changes. A maximum distance is obtained at a center region of MA 172, marked DC. A minimum distance is marked D(x0) at the left border region and D(xmax) at the right border region. In graph 170, B measured by MFMD 174 is shown versus the x position of MA 172. SL = (Bmax - B0) / L of B is linear in a range L. L / D can be relatively large. However, MA 172 is relatively complex in terms of manufacturing. Novel Tele cameras, often referred to as Super-Macro camera, perform Macro photography with high object-to-image magnifications of e.g. 1:1 -15:1 at object-lens distances (“u”) of e.g. 5cm – 30cm. As an example, using the thin lens equation 1 / ^^^=1 / ^+1 / ^ (“v” being the lens- image distance) for a Tele camera having EFL=25mm, a lens stroke of about 6.3mm is required to focus to 10cm (with respect to focus on infinity). In conclusion, focusing a Super-Macro” camera requires large lens strokes that significantly exceed 1mm. In addition, the control of such large lens strokes cannot be supported by known PSUs. Further examples that require large strokes of components are, for example, (i) a 2-state zoom camera described in co-owned international patent application PCT / IB2020 / 051405, (ii) a pop out mechanism that collapses a camera’s total track length (TTL) such as described in the co-owned international patent application PCT / IB2020 / 058697 and (iii) a continuous zoom camera such as described in international patent applications PCT / IB2020 / 051405, PCT / IB2021 / 061078, PCT / IB2022,052515 and PCT / IB2022 / 057189. There is need for, and it would be beneficial to have a PSU with a compact form factor that allows position sensing along large strokes L, i.e. strokes larger than 1mm. In addition, there is need for, and it would be beneficial to have a PSU with a compact form factor that allows position sensing along large strokes L, with sufficiently large slopes of 10mT / mm or more, and which is relatively simple to manufacture. SUMMARY In various exemplary embodiments, there is provided a PSU, comprising: a rectangular magnet having two magnet polarizations (MPs) and a dead zone (DZ) between the two MPs; and a magnetic flux measuring device (MFMD), the MFMD configured to measure a magnetic flux B, wherein the magnet is operational to move relatively to the MFMD along a first direction within a linear range L that fulfils 1mm ≤ L ≤ 25mm, wherein the MFMD is positioned at a distance D away from the magnet along a second direction perpendicular to the first direction, wherein D is in the range of 0.1mm to 3mm, wherein the DZ of the magnet forms an angle α with an axis parallel to a third direction perpendicular to the first and the second direction, and wherein α = 10 - 80 degrees. In various exemplary embodiments, there is provided a PSU comprising: a rectangular magnet having four magnet polarization domains (MPDs) including two MPs and three DZs, one DZ between each of the four MPDs; and a MFMD configured to measure a magnetic flux B, wherein the three DZs represent a left DZ, a center DZ, and a right DZ, wherein the magnet is operational to move relatively to the MFMD along a first direction within a linear range L that fulfils 1mm ≤ L ≤ 25mm, wherein the MFMD is positioned at a distance D away from the magnet along a second direction perpendicular to the first direction, wherein D is in the range of 0.1mm to 3mm, wherein the center DZ of the magnet forms an angle α with a third axis perpendicular to the first and the second direction, and wherein α = 10 – 80 degrees. In various exemplary embodiments, there is provided a PSU, comprising: a rectangular magnet having a single MP; and a MFMD configured to measure a magnetic flux B, wherein the magnet is operational to move relatively to the MFMD along a first direction within a linear range L that fulfils 1mm ≤ L ≤ 25mm, wherein the MFMD is positioned at a distance D away from the magnet along a second direction perpendicular to the first direction, wherein D is in the range of 0.1mm to 3mm, wherein the single MP forms an angle α with an axis parallel to a third direction perpendicular to the first and the second direction, and wherein α = 10 - 80 degrees. In some examples, α = 20 - 70 degrees. In other examples, α = 30 - 60 degrees. In some examples, the DZ is oriented parallel to one of the sides of the rectangular magnet. In other examples, the DZ forms an angle α with one of the sides of the rectangular magnet. In some examples, D may be constant along the linear range L. In some examples, L may be in the range 1mm ≤ L ≤ 15mm. In other examples, L may be in the range 1mm ≤ L ≤ 10mm. In yet other examples, L may be in the range 1mm ≤ L ≤ 5mm. In some examples, D may be in the range of 0.1mm to 1.5mm. In some examples, the PSU may be included in a voice coil motor (VCM), which includes one or more coils. In some such examples, the one or more coils may each have a rectangular shape or a trapezial shape. In some such examples, the one or more coils may be oriented parallel to the magnet. In other such examples, the one or more coils may be oriented parallel to the DZ. In some examples, the VCM may include one coil. In other examples, the VCM may include four coils. In some examples, the VCM may be included in smartphone camera. In some examples, the magnet may be made from a Neodymium based material. In various exemplary embodiments, there is provided a PSU, comprising: a magnet assembly (MA) having a width W measured along a first direction and a height H measured along a second direction perpendicular to the first direction and including one or more magnets having one or more respective magnetic polarizations; and a plurality of N<100 magnetic flux measuring devices (MFMDs), the plurality of MFMDs positioned along a MFMD axis parallel to the first direction and configured to measure a magnetic flux B generated by the MA, wherein each MFMD has a respective MFMD linear range Li, i = 1, 2, …, N, wherein the plurality of MFMDs is located at a distance D from the MA, D being measured along a third direction perpendicular to the first and the second direction, wherein D is in the range of 0.1mm to 3mm, wherein the MA is configured to move relative to the plurality of MFMDs along the first direction, the PSU having a unit linear range LUnit that fulfils 1mm ≤ LUnit ≤ 25mm, wherein LUnit starts at a first point x0 and ends at a final point xmax, wherein a minimum value Dmin of distance D fulfills LUnit / Dmin>10, and wherein at each position along LUnit, at least one MFMD out of the plurality of MFMDs is operated within its linear range Li. In some examples, the MA has a symmetry axis parallel to the second direction. In some examples, D may be not constant for different positions within stroke L. In some examples, L / Dmin>15. In other examples, L / Dmin>20. In some examples, B at x0 is B0 and B at xmax is Bmax and a slope SL = (B0 - Bmax) / L is larger than 10mT / mm. In some examples, SL = (B0- Bmax) / L is larger than 50 mT / mm. In some examples, SL = (B0- Bmax) / L is larger than 250 mT / mm. In some examples, SL = (B0- Bmax) / L is larger than 2500 mT / mm. In some examples, the MA has a left MA domain and a right MA domain along the first direction. In some examples, the magnetic polarization of the left MA domain is directed towards the MFMD. In other examples, the magnetic polarization of the right MA domain is directed away from the MFMD. In some examples, the MA has a left MA domain, a middle MA domain and a right MA domain along the first direction. In some examples, the magnetic polarization of the middle MA domain is directed parallel or anti-parallel to the first direction. In some examples, the MA includes a fourth MA domain and a fifth MA domain having respective magnetic polarizations, wherein the fourth MA domain is located to the left of the left MA domain and wherein the fifth MA domain is located to the right of the right MA domain. In some such examples, the magnetic polarization of the fourth MA domain is directed away from the MFMD. In other such examples, the magnetic polarization of the fifth MA domain is directed towards the MFMD. In some examples, a PSU may be included in a VCM. In some examples, the MFMD may be a Hall sensor. In some examples, the symmetry axis is located at a center of the middle MA domain. In some examples, a value of D between the left MA domain and MFMD is D(x0), a value of D between the right MA domain and the MFMD is D(xmax), a value of D between the middle MA domain and the MFMD is D(xmax / 2),D(x0)≤D(xmax / 2) and D(xmax) ≤ D(xmax / 2). In other examples, D(x0) = D(xmax) ≤ D(xmax / 2). In some examples, the left, middle and right MA domains may be rectangular. In other examples, the left and right MA domains may be trapezoids, and the middle MA domain may be a convex pentagon. In some examples, the VCM includes four coils. In some examples, D may be in the range of 0.1mm to 1.5mm. In some examples, LUnitmay be in the range 1mm ≤ LUnit≤ 15mm. In other examples,1mm ≤ LUnit≤ 10mm. In yet other examples, 1mm ≤ LUnit≤ 5mm. In some examples, L / W > 0.5. In other examples, L / W > 0.75. In some examples, L / H > 3. In other examples, L / H > 5. In some examples, the at least three magnets are made from a Neodymium based material. In some examples, a PSU as above or below may be included in a camera that includes a lens having an effective focal length (EFL) in the range of 2mm - 50mm, or 3mm - 30mm. In some examples, a PSU as above or below may be included in a camera that includes an image sensor having an image sensor diagonal (SD) in the range of 2mm - 25mm, or in the range of 5mm - 20mm. In some examples, a PSU as above or below may be included in a mobile device such as a smartphone or tablet. BRIEF DESCRIPTION OF THE DRAWINGS Non-limiting examples of embodiments disclosed herein are described below with reference to figures attached hereto that are listed following this paragraph. The drawings and descriptions are meant to illuminate and clarify embodiments disclosed herein, and should not be considered limiting in any way. Like elements in different drawings may be indicated like numerals. FIG.1A shows a first example of a known PSU in a side view; FIG.1B shows the PSU of FIG.1A in a top view; FIG.1C shows a second example of a known PSU in a side view; FIG.1D shows the PSU of FIG.1C in a top view; FIG.1E shows a third known example of a PSU in a top view; FIG.1F shows a fourth known example of a PSU in a top view; FIG.2A shows a first PSU disclosed herein in a side view; FIG.2B shows a second PSU disclosed herein in a side view; FIG.3A shows a third PSU disclosed herein in a side view. FIG.3B shows a fourth PSU disclosed herein in a side view. FIG.4A shows a fifth PSU disclosed herein in a side view. FIG.4B shows a voice coil motor disclosed herein and including the fifth PSU of FIG.4A in a side view. FIG.5A shows a sixth PSU disclosed herein in a side view. FIG. 5B shows another VCM disclosed herein and including the sixth PSU of FIG. 5A in a side view. FIG.5C shows yet another VCM disclosed herein and including the sixth PSU of FIG.5A in a side view. FIG.6A shows in cross-section a seventh PSU disclosed herein; FIG.6B shows in cross-section an eight PSU disclosed herein; FIG.7 shows in cross-section a nineth PSU disclosed herein; FIG.8 shows in cross-section a tenth PSU disclosed herein; FIG.9A shows in cross-section an eleventh PSU disclosed herein; FIG.9B shows yet another embodiment of a VCM disclosed herein. DETAILED DESCRIPTION FIG. 2A shows an exemplary embodiment of a first PSU disclosed herein and numbered 200, PSU 200 comprising a magnet 202 and a magnetic flux measuring device (MFMD) 206. PSU 200 as well as all other PSUs disclosed below may be advantageously included actuators such as VCMs used in compact digital cameras integrated in handheld mobile devices such as smartphones or tablets. In terms of dimensions such as size (defined by width W202 and height H202) and magnet parameters such as magnet polarization domains (MPDs), magnet 202 may be identical to magnet 102 of PSU 100. However, with respect to magnet 102 (FIG.1A), magnet 202 is tilted (or rotated) around an axis perpendicular to the x-y plane by an angle α1, as shown. Here, DZ 110 represents a plane defined by its normal (NDZ). NDZforms an angle α1with the x-axis. D may be for example in the range of 0.1mm-2mm. The position of magnet 202 changes within stroke L2A, which is limited by x0and xmax. That is, a length L2A of the stroke (or linear range) of PSU 200 is given by L2A = xmax - x0, the direction of stroke L2A is substantially parallel to the x-axis. Borders x0 and xmax stroke L2A can be defined by a distance from DZ 210. Exemplarily and consistent with FIG.1A, we assume that x0 and xmax are respectively located at a distance W202 / 2 from a center 208 of DZ 210, as shown. FIG. 2A also shows a graph 208 of B vs. the position of magnet 202 along the x-axis, measured by MFMD 206. B is a function of x, i.e. B = B(x). Within stroke L2A, slope SL2A = (Bmax- B0) / L2A of B is linear; outside of L2A, B(x) is not linear. Because of the tilting of magnet 202 and with respect to stroke L1A and SL1A respectively in FIG.1A, stroke L2A is extended (or “enlarged”) by a factor proportional to 1 / cos(α1), i.e. L2A = L1A / cos(α1), and slope SL2A is shallower by a factor proportional to 1 / L2A, i.e. SL2A=SL1A ^(L1A / L2A). It is noted that this is approximately valid for magnet 102 and magnet 202, as they have identical dimensions and identical magnet parameters. Angle α1may be in the range of about α1= 10 – 80 degrees, beneficially α1= 20 – 70 degrees, or even α1= 30 – 60 degrees. The value of α1is selected by considering the following trade-off: a large angle α1 is desired for PSUs having a relatively long L (given a particular magnet size and geometry). However, a large angle α1 also decreases the SL of a PSU which, at some point, makes it difficult to robustly control actuation. In other examples, more than one MFMD such as MFMD 206 may be used to extend a stroke such as L2A even further. FIG. 2B shows another exemplary embodiment of a second PSU disclosed herein and numbered 250, PSU 250 comprising a magnet 252 and a MFMD 256. In terms of dimensions (defined by width W252 and height H252) and magnet parameters such as magnet polarization (MP), magnet 252 may be identical to magnet 122 of PSU 120 (FIG.1B). With respect to magnet 122, magnet 252 is tilted around an axis perpendicular to the x-y plane by an angle α2, as shown. Magnet 252 has a center C located at a symmetry axis 258. C represents a plane defined by a normal on C (NC). NC forms an angle α2 with the x-axis. The position of magnet 252 changes within stroke L2B, which is given by L2B = xmax – x0. The direction of L2B is substantially parallel to the x-axis. Exemplarily and consistent with FIG.1C, we assume that x0 and xmax are respectively located at a distance W252 / 2 from C (i.e. from SA 258 of magnet 252), as shown. FIG. 2B also shows a graph 254 of B vs. the position of magnet 252 along the x-axis, measured by MFMD 256. Within stroke L2B, slope SL2B = (Bmax– B0) / L2B is linear. Because of the tilting of magnet 252 and in comparison with stroke L1C and slope SL1C respectively in FIG. 1C, stroke L2B is extended by a factor proportional to 1 / cos(α2), i.e. L2B = L1C / cos(α2), and slope SL2B is shallower by a factor proportional to 1 / L2B, i.e. SL2B = SL1C ^(L1C / L2B). Angle α2 may be in the range of about α2 = 10 – 80 degrees, beneficially α2 = 20 – 70 degrees, or even α2 = 30 – 60 degrees. The value of α2is selected by considering the trade-off discussed above for α1. In other examples of PSUs, more than one magnet such as magnet 202 or magnet 252 may be used in a MA that includes a plurality of magnets, for example two, three, four or even five magnets. For all PSUs disclosed herein, values and ratios of values may be: - A width W of an MA may be W = L +1 / 2mm or larger, wherein L is the linear range of the PSU. - A width W, a height H and a length of an MA may be in the ranges of W = 1mm – 50mm, or W = 1mm – 15mm, H = 0.25mm – 5mm and length = 1mm – 15mm. - Constant distance D between MA and MFMD: D = 0.1mm – 3mm. - Variable distance D between MA and MFMD: Dmin = 0.1mm – 1mm, Dmax= 0.25mm – 3mm. - Linear range L may be in the range L = 0.5mm-50mm or in the range L = 1mm-25mm and beneficially in the range L = 1mm-10mm or L = 1mm-5mm. - Number of MFMDs used = 1 - 10, or 1- 4. FIG. 3A shows another exemplary embodiment of a third PSU disclosed herein and numbered 300, PSU 300 comprising a magnet 302 and a MFMD 306. In terms of dimensions such as size (defined by width W302 and height H302), magnet 302 may be identical to magnet 102 (FIG. 1A). However, vs. magnet 102, a DZ 310 of magnet 302 is tilted around an axis perpendicular to the x-y plane by an angle β1. Magnet 302 has a first MPD 304, a second MPD 305 and a C located at a diagonal 308 of magnet 302. The MPs of first MPD 304 and second MPD 305 respectively are parallel and anti-parallel to an axis perpendicular to the x-y plane, as shown. Magnet 302 causes a magnetic field 312. A distance D between magnet 302 and MFMD 306 does not change when magnet 302 moves. An upper and lower limit of stroke (L3A) can be defined by a distance from DZ 310. Exemplarily and consistent with FIGS.1A-B, 2A, we assume that x0 and xmaxare respectively located at a distance W302 / 2 from a center of DZ 310, as shown. FIG. 3A also shows a graph 314 of B vs. the position of magnet 302 along the x-axis, measured by MFMD 306. Within stroke L3A, slope SL3A = (Bmax- B0) / L3A of B is linear. Because of the tilting of magnet 302 and in comparison with stroke L1A and SL1A respectively, stroke L3A is extended by a factor proportional to 1 / cos(β1), i.e. L3A = L1A / cos(β1), and slope SL3A is shallower by a factor proportional to 1 / L3A, i.e. SL3A=SL1A ^(L1A / L3A). Angle β1 may be in the range of about β1= 10 – 80 degrees, beneficially β1= 20 – 70 degrees, or even β1= 30 – 60 degrees. A value of β1is selected by considering the trade-off explained above for angle α1. FIG. 3B shows yet another exemplary embodiment of a fourth PSU disclosed herein and numbered 350, comprising a magnet 352 and a MFMD 356. In terms of dimensions (defined by width W352 and height H352), magnet 352 may be identical to magnet 122 (FIG. 1C). Magnet 352 has a homogenous MP 354 that forms an angle β2 with the x-axis. Compared to magnet 122, MP 354 of magnet 352 is tilted around an axis perpendicular to the x-y-axis by an angle β2, as shown. Magnet 352 has a diagonal 358. Diagonal 358 represents a plane defined by its normal (ND), which here is parallel to MP 354. In other examples, a MP such as MP 354 may not be perpendicular to diagonal 358, but may form an angle different from 90 degrees. NDforms an angle β2 with the x-axis. Magnet 352 causes a magnetic field 312. Distance D between magnet 352 and MFMD 356 does not change when magnet 352 moves. Borders x0 and xmax of stroke L3B can be defined by a distance from diagonal 358. Exemplarily, we assume that x0 and xmax are respectively located at a distance W352 / 2 from a border of magnet 352, as shown. FIG. 3B also shows a graph 364 of B vs. the position of magnet 352 along the x-axis, measured by MFMD 356. Within stroke L3B, slope SL3B = (Bmax – B0) / L3B of B is linear. As of the tilting of MP 354 and in comparison with stroke L1C and slope SL1C respectively, stroke L3B is extended by a factor proportional to 1 / cos(β2), i.e. L3B = L1C / cos(β2), and SL3B is shallower by a factor proportional to 1 / SL3B, i.e. SL3B=SL1C ^(L1C / L3B). It is noted that this is approximately valid for magnet 152 and magnet 352 having identical dimensions. Angle β2may be in the range of about β2 = 10 – 80 degrees, beneficially β2 = 20 – 70 degrees or even β2 = 30 – 60 degrees. A value of β2 is selected by considering the trade-off as explained above for angle α1. FIG. 4A shows another exemplary embodiment of a fifth PSU disclosed herein and numbered 400, PSU 400 comprising a magnet 402 and a MFMD 406. Magnet 402 has a first MPD 404-1, a second MPD 404-1, a third MPD 404-2, a fourth MPD 405-2, a magnet width W402, a magnet height H402. The MPs of first MPD 404-1 and third MPD 404-2 are identical, and parallel to an axis perpendicular to the x-y plane, as shown. The MPs of second MPD 405-1 and fourth MPD 405-2 are identical, and anti-parallel to an axis perpendicular to the x-y plane. Magnet 402 has a first DZ 408, a second DZ 410 and a third DZ 412. Each of the three DZs has a DZW in the range of for example DZW = 0.1mm – 0.5mm. This means that magnet 402 comprises four MPDs, three DZs and two different MPs. DZ 410 of magnet 402 is tilted around an axis perpendicular to the x-y-plane by an angle γ, as shown. DZ 410 represents a plane defined by the normal (NDZ). NDZforms an angle γ with the x-axis. In the following, we may refer to second DZ 410 as “center DZ”, as it is located at a center position between first DZ 408 and third DZ 412. To first DZ 408 we refer as “left DZ” and to third DZ 412 we refer as “right DZ”. Magnet 402 causes a magnetic field. A distance D between magnet 402 and MFMD 406 does not change when magnet 402 moves. A position of magnet 402 changes within stroke L4. Exemplarily, we assume that x0and xmaxare located at an edge (or border) of DZ 410, as shown. MFMD 406 is shown in a “zero-position”, i.e. in a center position of L4. B may be a function of x. Within stroke L4, slope SL4 = (Bmax– B0) / L4 of B is linear. Angle γ may be in the range of about γ = 10 – 80 degrees, beneficially γ = 20 – 70 degrees or even γ = 30 – 60 degrees. A value of γ is selected by considering the trade-off as explained above for angle α1. FIG.4B shows an exemplary embodiment of a (VCM disclosed herein and numbered 450, comprising PSU 400 and a coil assembly (CA) 452. CA 452 includes four coils, a first coil 454, a second coil 456, a third coil 458 and a fourth coil 460. CA 452’s four coils are aligned at a same distance DCOIL (not shown) of about 0.1mm-2mm (measured along an axis perpendicular to the x- y plane) from PSU 400. That is, the four coils lie in one plane. VCM 450 is shown in a zero- position, i.e. in a center position of L4. CA 452 is operational to provide a controllable magnetic field. The coils included in CA 452 are oriented parallel to the x-y coordinate system shown, i.e. a top edge and a bottom edge (or border) of the coils are oriented parallel to the x-axis and a left edge and a right edge of the coils are oriented parallel to the y-axis. The coils included in CA 452 are also oriented parallel to magnet 402, i.e. edges of the coils included in CA 452 are parallel to edges of magnet 402. In other examples, CA 452 may include only one coil, 2 or 3 coils, or even more coils, e.g. 5 or 6 coils. In yet other examples, VCM 450 may include PSU 200, or PSU 250, or PSU 300 or PSU 350. The magnetic field caused by PSU 400 in interaction with the controllable magnetic field generated by CA 452 actuates a relative motion between magnet 402 and both MFMD 406 and CA 452 along the x-axis. Typically and with respect to a mobile device (e.g. a smartphone or tablet) that includes VCM 450, MFMD 406 and CA 452 are at rest and magnet 402 moves. In general, this is beneficial as both MFMD 406 and CA 452 are electrically connected to respective electrical control units, but magnet 402 is not. In some examples for lens focusing in mobile devices that include a compact digital camera, magnet 402 may be fixedly coupled to a lens of the camera for actuating the lens to move relative to an image sensor of the camera, where the image sensor is at rest relative to the mobile device. In other examples, for changing a zoom factor (i.e. an effective focal length EFL) of a camera included in a mobile device, the lens of the camera may be divided into two or more lens groups, where magnet 402 may be fixedly coupled to a particular lens group for actuating the particular lens group to move relative to other lens groups and relative to a camera’s image sensor, where the image sensor is at rest relative to the mobile device. The considerations are valid also for VCM 520 and VCM 550 (FIGS. 5A-B) as well as for VCM 900 and VCM 950 (FIGS.9A-B). FIG. 5A shows yet another exemplary embodiment of a sixth PSU disclosed herein and numbered 500, PSU 500 comprising a magnet 502 and a MFMD 506. Magnet 402 has a first MPD 504 and a second MPD 505, a magnet width W402, a magnet height H402. First MPD 504 is parallel to an axis perpendicular to the x-y-plane, as shown. Second MPD 505 is anti-parallel to the x-y-plane. DZ 508 of magnet 502 is tilted around an axis perpendicular to the x-y-plane by an angle δ, as shown. DZ 508 represents a plane defined by NDZ. NDZ forms an angle δ with the x- axis. Distance D between magnet 502 and MFMD 506 does not change. Stroke L5 of PSU 500 is given by xmax- x0, and its direction is substantially parallel to the x-axis. An upper and lower limit of L5 can be defined by a distance from DZ 508. Exemplarily, we assume that x0and xmaxare located at an edge of DZ 410, as shown. We note that the position of x0and xmaxand thus the length of L5 depend on structural details of magnet 502, especially on angle δ. MFMD 506 is shown in a zero-position, i.e. in a center position of L5. Within L5, slope SL5 = (Bmax - B0) / L5 of B is linear. Angle δ may be in the range of about δ = 10 – 80 degrees, beneficially δ = 20 – 70 degrees, or even δ = 30 – 60 degrees. A value of δ is selected by considering the trade-off as explained above for angle α1. FIG.5B shows another exemplary embodiment of a VCM disclosed herein and numbered 520, comprising PSU 500 and a coil 522. Coil 522 is located at a distance DCOIL(not shown, measured along an axis perpendicular to the x-y plane) from PSU 500. VCM 520 is shown in a zero-position, i.e. in a center position of L5. Coil 522 is operational to provide a controllable magnetic field. Coil 522 is oriented parallel to DZ 508, i.e. a left edge and a right edge of coil 522 are oriented parallel to DZ 508. In comparison with one of the coils included in CA 452, coil 522 is tilted around an axis perpendicular to the x-y-plane by angle δ. This means that coil 522 is not oriented parallel to magnet 502, i.e. edges of coil 522 are not parallel to edges of magnet 502, but they form an angle (different from 0 degrees and 90 degrees) to each other. Coil 522 has a rectangular shape, i.e. a left or right border of coil 522 forms an angle of 90 degrees with a top or bottom border of coil 522. In other examples, coil 522 may be replaced by a CA including more than one coil, for example 2 or 3 or 4 or even 5 (rectangular) coils (FIG.4B, FIG.9B). In yet other examples, VCM 520 may include any other PSU disclosed herein. FIG. 5C shows yet another exemplary embodiment of a VCM disclosed herein and numbered 550, comprising PSU 500 and a coil 552. Coil 552 is located at a distance DCOIL (not shown, measured along an axis perpendicular to the x-y-plane) from PSU 500. VCM 550 is shown in a zero-position. Coil 552 is operational to provide a controllable magnetic field. Coil 552 is oriented parallel to DZ 508, i.e. a left edge and a right edge of coil 552 are oriented parallel to DZ 508, as shown. Coil 552 has a trapezial shape, i.e. a left or right border of coil 552 forms an angle differing from 90 degrees with a top or bottom border of coil 552. A top side and a bottom side of coil 552 are oriented parallel to a top and a bottom side of magnet 502, but a left side and a right side of coil 552 are not oriented parallel to a left side and a right side of magnet 502, but they form an angle (different from 0 degrees and 90 degrees) to each other. In other examples, coil 552 may be replaced by a CA including more than one coil, for example 2 or 3 or 4 or even 5 (trapezoidal) coils. In yet other examples, VCM 550 may include any other PSU disclosed herein. Magnets described herein may be made from any material known to be used in the industry, specifically in digital cameras used in mobile electronic devices such as smartphones, for example any Neodymium based material, e.g. N48H, N48SH etc. x0 and xmax may be chosen so that their middle or symmetry point xS= xmax / 2 is located at C, or they may be chosen otherwise. That is, the symmetry axis of the stroke with respect to y is located at xS= xmax / 2 and may be identical with SA 108 of magnet 102 or it may be located at another position. It is noted here that D refers to a distance between a magnet and an external envelope (i.e. a housing of a packaging device) surrounding a MFMD, and not to the distance to the MFMD itself. In general, the MFMD may be located at a distance of about 50μm-250μm from the housing. For calculating the distance between a magnet and the MFMD, the MFMD-housing distance must be added to D. Additionally, it is noted that D is not shown in scale. FIG. 6A shows an exemplary embodiment of a seventh PSU disclosed herein and numbered 600, PSU 600 comprising MA 152 and a magnetic flux measuring device assembly (MFMDA) 602. MFMDA 602 includes a first MFMD 604 and a second MFMD 606. First MFMD 604 and second MFMD 606 may be identical in terms of size and performance. First MFMD 604 and second MFMD 606 are positioned along a MFMDA axis 608 (parallel to the x-axis). MFMDA 602 is located at a constant distance D=DC(measured along the y axis) from MFMDA axis 608. DCmay be for example 0.1mm-2mm. For position sensing, MA 152 moves from x0to xmaxin the x direction and relative to MFMDA 604. In graph 610, B measured by MFMDA 602 is shown versus the x position of MA 152. Within stroke L600 of PSU 600, B600 = B600(x) ~ x. Index 600 indicates that B600 represents a measurement output of PSU 600. Stroke L600 is divided into a first sub-stroke L604 ranging (or extending) from x0604to xmax604, and a second sub-stroke L606 ranging from x0606to xmax606. First sub-stroke L604represents a linear range of MFMD 604, and second sub-stroke L606represents a linear range of MFMD 606. Graph 612 shows the linear relationship between B604 and x, within stroke L604, B604 = B604(x) ~ x. Graph 614 shows the linear relationship between B606 and x. Indices 604 and 606 indicate that B604 and B606 represent measurement outputs of MFMD 604 and of MFMD 606 respectively. A measurement output of PSU 600 may be calculated from the measurement outputs of MFMD 604 and of MFMD 606 by B600(x) = ½ (B604(x) + B606(x)), or more general by B600(x) ~ B604(x) + B606(x). FIG. 6B shows another exemplary embodiment of an eighth PSU disclosed herein and numbered 650. PSU 650 comprises MA 152 as described in FIG 1E, FIG.6A and a MFMDA 652. MFMDA 652 includes first MFMD 604, second MFMD 606 and a third MFMD 654. First MFMD 604, second MFMD 606 and third MFMD 654 may be identical in terms of size and performance. First MFMD 604, second MFMD 606 and third MFMD 654 are positioned along a MFMDA axis 656 (parallel to the x-axis). MFMDA 652 is located at a constant D from MFMDA axis 656. In graph 658, B measured by MFMDA 652 is shown versus the x position of MA 152. Within stroke L650 of PSU 650, B650 = B650(x) ~ x. Index 650 indicates that B650 represents a measurement output of PSU 650. L650 is divided into a first sub-stroke L604 ranging from x0604to xmax604, a second sub- stroke L606 ranging from x0606to xmax606and a third sub-stroke L654 ranging from x0654to xmax654. First sub-stroke L604represents a linear range of MFMD 604, second sub-stroke L606represents a linear range of MFMD 606 and third sub-stroke L654represents a linear range of MFMD 654. Graph 612 shows the linear relationship between B604and x, within stroke L604, B604= B604(x) ~ x. Graph 614 shows the linear relationship between B606and x, within stroke L606. Graph 660 shows the linear relationship between B654 and x, within stroke L654. Indices 604, 606 and 654 indicate that B604, B606 and B654 represent measurement outputs of MFMD 604, of MFMD 606 and of MFMD 654 respectively. A measurement output of PSU 650 may be calculated from the measurement outputs of MFMD 604, of MFMD 606 and of MFMD 654 by B650(x) = 1 / 3 (B604(x) + B606(x) + B654(x)), or more general by B650(x) ~ B604(x) + B606(x) + B654(x). As visible in FIGS.6A-B, L650> L600. In good approximation, L650= 3 / 2x L600. The linear range of a PSU such as PSU 600 or PSU 650 can be extended by adding one or more additional MFMDs to the PSU. One may refer to this as concatenation of MFMDs, where the goal of the concatenation is to extend the linear range of a PSU including a particular MA. In a general manner, a PSU including a MA such as MA 152 may include N MFMDs aligned along a MFMD axis, whereas where N indicates the number of MFMDs included in the PSU. N may be in the range 2 – 10 or even 2 - 50. A linear range LUNIT of the PSU including N MFMDs may be approximately given by LUNIT = N / 2 ^ L600. This means that a linear range of such a PSU can be extended significantly. Each MFMD may have a measurement output Bi, i =1,… N. A measurement output BUNIT(x) of the PSU including N MFMDs may be calculated from the measurement outputs of the N MFMDs by BUNIT(x) = 1 / N (B1(x) + B2(x) +… + BN(x)), or more general by BUNIT(x) ~ B1(x) + B2(x) +… + BN(x). In other examples, one may divide LUNIT into sub-strokes, e.g. into sub-strokes such as L604, L606, and L654, and, depending on the sub-stroke, one or more MFMDs may be used for sensing BUNIT(x). In a first example, within L604, BUNIT(x) = B604(x), within L606, BUNIT(x) = B606(x), and within L654, BUNIT(x) = B654(x). In a second example, within a sub-stroke formed by L604+L606, BUNIT(x) = 1 / 2(B604(x) + B606(x)), and within another sub-stroke formed by L604+L654, BUNIT(x) = 1 / 2(B604(x) + B654(x)). FIG. 7 shows yet another exemplary embodiment of a ninth PSU disclosed herein and numbered 700, PSU 700 comprising MA 172 and a MFMDA 702. MFMDA 702 includes MFMD 174, a second MFMD 706 and a third MFMD 708. MFMD 174, second MFMD 706 and third MFMD 708 may be identical in terms of size and performance. MFMD 174, second MFMD 706 and third MFMD 708 are positioned along a MFMDA axis 710 (parallel to the x-axis). MA 172 is located at a constant D from MFMDA axis 710. For position sensing, MA 702 moves along a stroke L700of PSU 700. In graph 712, the B measured by MFMDA 704 is shown versus the x position of MA 702. Graph 712 shows the linear relationship between B700and x, i.e. within stroke L700, B700 = B700(x) ~ x. Stroke L700 ranges from x0 to xmax and is divided into a first sub-stroke L174 ranging from x0174to xmax174, a second sub-stroke L706 ranging from x0706to xmax706and a third sub-stroke L708 ranging from x0708to xmax708. First sub-stroke L174 represents a linear range of MFMD 174, second sub-stroke L706represents a linear range of MFMD 706 and third sub-stroke L708represents a linear range of MFMD 708. Graph 170 shows the linear relationship between B174and x, graph 714 shows the linear relationship between B706and x and graph 716 shows the linear relationship between B708 and x. A measurement output of PSU 700 may be calculated from the measurement outputs of MFMD 174, of MFMD 706 and of MFMD 708 by B700(x) = 1 / 3 (B174(x) + B706(x) + B708(x)), or more general by B700(x) ~ B174(x) + B706(x) + B708(x). In other examples and for extending a linear range of a PSU such as PSU 700, a PSU including a MA such as MA 702 may include a MFMDA including N MFMDs aligned along a MFMD axis, where N indicates the number of MFMDs included in the PSU. N may be in the range 2 – 5, or 2 – 10 or even 2 - 50. A linear range LUNIT of the PSU including N MFMDs may be approximately given by LUNIT = N / 2 ^ L700. Each MFMD may have a measurement output Bi, i =1,… N. A measurement output BUNIT(x) of the PSU including N MFMDs may be calculated from the measurement outputs of the N MFMDs by BUNIT(x) = 1 / N (B1(x) + B2(x) +… + BN(x)), or more general by BUNIT(x) ~ B1(x) + B2(x) +… + BN(x). FIG. 8 shows yet another exemplary embodiment of a tenth PSU disclosed herein and numbered 800, PSU 800 comprising a MA 802 and a MFMDA 804. MA 802 includes a first magnet 806 having a first MP 808 and a second magnet 810 having a second MP 812 (anti-parallel to first MP 808). MA 802 has a width W802, a height H802 and a C located at SA 814 (with respect to y) of MA 802. MA 802 causes a magnetic field 816 in its surroundings. MFMDA 804 includes a first MFMD 818, a second MFMD 820 and a third MFMD 822. First MFMD 818, a second MFMD 820 and a third MFMD 822 may be identical in terms of size and performance. First MFMD 818, a second MFMD 820 and a third MFMD 822 are positioned along a MFMDA axis 824 (parallel to the x-axis). MFMDA 804 is located at a constant D from MFMDA axis 824, which may be D=0.1mm-3mm. For position sensing, MA 802 moves along stroke L800 of PSU 800. In graph 826, B measured by MFMDA 804 is shown versus the x position of MA 802, and there is a linear relationship between B800and x, i.e. within stroke L800, B800= B800(x) ~ x. L800ranges from x0to xmaxand is divided into a first sub-stroke L818ranging from x0818to xmax818, a second sub-stroke L820ranging from x0820to xmax820and a third sub-stroke L822ranging from x0822to xmax822. First sub-stroke L818 represents a linear range of MFMD 818, second sub-stroke L820 represents a linear range of MFMD 820 and third sub-stroke L822 represents a linear range of MFMD 822. Graph 828 shows the linear relationship between B818 and x. Graph 830 shows the linear relationship between B820and x, within stroke L820. Graph 832 shows the linear relationship between B822and x within stroke L822. Indices 818, 820 and 822 indicate that B818, B820and B822represent measurement outputs of MFMD 818, of MFMD 820 and of MFMD 822 respectively. A measurement output of PSU 800 may be calculated from the measurement outputs of MFMD 818, MFMD 820 and MFMD 822 by B800(x) = 1 / 3 (B818(x) + B820(x) + B822(x)), or more general by B800(x) ~ B818(x) + B820(x) + B822(x). First magnet 806 and second magnet 810 may have a same shape and dimension and may be symmetric with respect to SA 814. As of their symmetry, the following description of first magnet 806 applies also for second magnet 810. First magnet 806 has a straight (or uniform) back surface 834 oriented parallel to the x-axis and a front surface that is divided into a straight surface region 836 and a sloped surface region 838. Sloped surface region 838 may form an angle of about 30 – 60 degrees with the y-axis or even 10 – 80 degrees with the y-axis. In other examples and for extending a linear range of a PSU such as PSU 800, a PSU including a MA such as MA 802 may include N MFMDs all aligned along a MFMD axis, where N indicates the number of MFMDs included in the PSU. N may be in the range 2 - 10 or even 2 - 50. A linear range LUNIT of the PSU including N MFMDs may be approximately given by LUNIT = N / 2 ^ L800. This means that a linear range of such a PSU can be extended significantly. Each MFMD may have a measurement output Bi, i =1,… N. A measurement output BUNIT(x) of the PSU including N MFMDs may be calculated from the measurement outputs of the N MFMDs by BUNIT(x) = 1 / N (B1(x) + B2(x) +… + BN(x)), or more general by BUNIT(x) ~ B1(x) + B2(x) +… + BN(x). FIG. 9A shows yet another exemplary embodiment of an eleventh PSU disclosed herein and numbered 900. PSU 900 comprises a MA 902 that includes five permanent magnets 902a, 902b, 902c, 902d and 902e having respective magnetic MPs 904a, 904b, 904c, 904d and 904e, and a MFMDA 906. MFMDA 906 includes three MFMDs, MFMD 908, MFMD 910 and MFMD 912 that are positioned along a MFMD axis 914. MFMD 908, MFMD 910 and MFMD 912 may be identical in terms of size, shape and performance. Magnets 902a, 902b and 902c are not rectangular, while magnets 902d and 902e are rectangular. Magnets 902a and 902c as well as 902d and 902e have the same shape and dimensions, but opposite magnetizations 904a and 904c and 904d and 904e respectively. Magnets 902a, 902c, 902d and 902e are positioned symmetrically with respect to magnet 902b. Center C of MA 902 (with respect to x) is located at SA 912 (with respect to y) of both magnet 902b and MA 902. MA 902 is shaped symmetrically around C with respect to y. MA 902 causes a magnetic field (not shown). At C, MFMD axis 914 is located at DCaway from MA 902. MA 902 moves along a stroke L in x direction relative to MFMDA 906. The position of MA 902 along x varies from x0 to xmax. x0 and xmax may be chosen so that their center or symmetry point xs = xmax / 2 is located at C, or they may be chosen otherwise. Between x0 to xmax, D is a function of x, D = D(x). For 900, D(x0) = D(xmax) < DC, D(x0) = D(xmax) = Dminand L / Dmin>10. Typically, Dmin≥0.1mm. At x0, the magnetic MP 904a is substantially directed towards MFMDA 906. At xmax, 904c is substantially directed away from MFMDA 906. At C, 904b is directed substantially parallel or anti-parallel to x. 904d is directed substantially anti-parallel to 904a.904e is directed substantially anti-parallel to 904c. Additionally to the three MA domains defined by magnets 902a, 902b and 902c, in MA 902 there are two additional MA domains defined by magnets 902d and 902e. B (not shown) is measured by MFMDA 906 versus the x position of MA 202. B is a function of x, i.e. B900=B(x). In L, SL = (Bmax - B0) / ΔX of B is linear. For measuring B900 of PSU 900, one may use L908 of MFMD 908, L910 of MFMD 910 and L912 of MFMD 912 as described above e.g. for PSU 400 or for PSU 900. FIG. 9B shows yet another exemplary embodiment of a VCM disclosed herein and numbered 950. VCM 950 includes a CA 960 and PSU 900. CA 960 includes four coils 960a, 960b, 960c and 960d. CA 960 can generate a magnetic field. In VCM 950, the magnetic field caused by PSU 900 additionally provides, together with the magnetic field generated by CA 960, the magnetic field configuration which is required for actuating a relative motion between MA 902 and CA 960 as well as MFMDA 906. Typically and with respect to a mobile device that includes VCM 960, MFMDA 906 and CA 960 are at rest and MA 902 moves. In some examples for lens focusing, MA 902 may be fixedly coupled to a camera’s lens for actuating the lens to move relative to an image sensor of the camera, wherein the image sensor is at rest with respect to the mobile device. In other embodiments, a VCM like VCM 950 may include any other PSU disclosed herein. While this disclosure has been described in terms of certain embodiments and generally associated methods, alterations and permutations of the embodiments and methods will be apparent to those skilled in the art. The disclosure is to be understood as not limited by the specific embodiments described herein, but only by the scope of the appended claims. Unless otherwise stated, the use of the expression “and / or” between the last two members of a list of options for selection indicates that a selection of one or more of the listed options is appropriate and may be made. It should be understood that where the claims or specification refer to "a" or "an" element, such reference is not to be construed as there being only one of that element. Furthermore, for the sake of clarity the term "substantially" is used herein to imply the possibility of variations in values within an acceptable range. According to one example, the term "substantially" used herein should be interpreted to imply possible variation of up to 10% over or under any specified value. According to another example, the term "substantially" used herein should be interpreted to imply possible variation of up to 5% over or under any specified value. According to a further example, the term "substantially" used herein should be interpreted to imply possible variation of up to 2.5% over or under any specified value. All references mentioned in this specification are herein incorporated in their entirety by reference into the specification, to the same extent as if each individual reference was specifically and individually indicated to be incorporated herein by reference. In addition, citation or identification of any reference in this application shall not be construed as an admission that such reference is available as prior art to the present invention.

Claims

WHAT IS CLAIMED IS:

1. A position sensing unit (PSU), comprising: a rectangular magnet having two magnet polarizations (MPs) and a dead zone (DZ) between the two MPs; and a magnetic flux measuring device (MFMD), the MFMD configured to measure a magnetic flux B, wherein the magnet is operational to move relatively to the MFMD along a first direction within a linear range L that fulfils 1mm ≤ L ≤ 25mm, wherein the MFMD is positioned at a distance D away from the magnet along a second direction perpendicular to the first direction, wherein D is in the range of 0.1mm to 3mm, wherein the DZ of the magnet forms an angle α with an axis parallel to a third direction perpendicular to the first and the second direction, and wherein α = 10 - 80 degrees.

2. The PSU of claim 1, wherein α = 20 - 70 degrees.

3. The PSU of claim 1, wherein α = 30 - 60 degrees.

4. The PSU of claim 1, wherein the DZ is oriented parallel to one of the sides of the rectangular magnet.

5. The PSU of claim 1, wherein the DZ forms an angle α with one of the sides of the rectangular magnet.

6. The PSU of claim 1, wherein D is constant along L.

7. The PSU of claim 1, wherein 1mm ≤ L ≤ 15mm.

8. The PSU of claim 1, wherein 1mm ≤ L ≤ 10mm.

9. The PSU of claim 1, wherein 1mm ≤ L ≤ 5mm.

10. The PSU of claim 1, wherein D is in the range of 0.1mm to 1.5mm.

11. The PSU of any of the claims 1 to 10, wherein the PSU is included in a voice coil motor (VCM), wherein the VCM in addition includes one or more coils.

12. The VCM of claim 11, wherein the one or more coils each have a rectangular shape.

13. The VCM of claim 11, wherein the one or more coils each have a trapezial shape.

14. The VCM of claim 11, wherein the one or more coils are oriented parallel to the magnet.

15. The VCM of claim 11, wherein the one or more coils are oriented parallel to the DZ.

16. The VCM of claim 11, wherein the VCM includes one coil.

17. The VCM of claim 11, wherein the VCM includes four coils.

18. The PSU of claim 11, wherein the VCM is included in smartphone camera.

19. The PSU of claim 1, wherein the magnet is made from a Neodymium based material.

20. The PSU of any of the claims 1 to 17, wherein the PSU is included in a camera, and wherein the camera includes a lens having an effective focal length (EFL) in the range of 2mm - 50mm.

21. The PSU of claim 20, wherein the EFL is in the range of 3mm - 30mm.

22. The PSU of any of the claims 1 to 17, wherein the PSU is included in a camera, and wherein the camera includes an image sensor having an image sensor diagonal (SD) in the range of 2mm - 25mm.

23. The PSU of claim 22, wherein SD is in the range of 5mm - 20mm.

24. The PSU of any of the claims 1 to 17, wherein the PSU is included in a mobile device.

25. The PSU of claim 24, wherein the mobile device is a smartphone.

26. A position sensing unit (PSU), comprising: a rectangular magnet having four magnet polarization domains (MPDs) including two MPs and three dead zones (DZs), one DZ between each of the four MPDs; and a magnetic flux measuring device (MFMD), the MFMD configured to measure a magnetic flux B, wherein the three DZs represent a left DZ, a center DZ, and a right DZ, wherein the magnet is operational to move relatively to the MFMD along a first direction within a linear range L that fulfils 1mm ≤ L ≤ 25mm, wherein the MFMD is positioned at a distance D away from the magnet along a second direction perpendicular to the first direction, wherein D is in the range of 0.1mm to 3mm, wherein the center DZ of the magnet forms an angle α with a third axis perpendicular to the first and the second direction, and wherein α = 10 – 80 degrees.

27. The PSU of claim 26, wherein α = 20 – 70 degrees.

28. The PSU of claim 26, wherein α = 30 – 60 degrees.

29. The PSU of claim 26, wherein D is constant along L.

30. The PSU of claim 26, wherein D is in the range of 0.1mm to 1.5mm.

31. The PSU of claim 26, wherein 1mm ≤ L ≤ 15mm.

32. The PSU of claim 26, wherein 1mm ≤ L ≤ 10mm.

33. The PSU of claim 6, wherein 1mm ≤ L ≤ 5mm.

34. The PSU of any of the claims 25 to 33, wherein the PSU is included in a voice coil motor (VCM), and wherein the VCM in addition includes one or more coils.

35. The PSU of claim 34, wherein the one or more coils each have a rectangular shape.

36. The PSU of claim 34, wherein the one or more coils each have a trapezial shape.

37. The PSU of claim 34, wherein the one or more coils are oriented parallel to the magnet.

38. The PSU of claim 34, wherein the one or more coils are oriented parallel to the DZ.

39. The PSU of claim 34, wherein the VCM includes one coil.

40. The PSU of claim 34, wherein the VCM includes four coils.

41. The PSU of claim 34, wherein the VCM is included in smartphone camera.

42. The PSU of claim 26, wherein the magnet is made from a Neodymium based material.

43. The PSU of any of the claims 26 to 40, wherein the PSU is included in a camera, and wherein the camera includes a lens having an effective focal length (EFL) in the range of 2mm - 50mm.

44. The PSU of claim 43, wherein the EFL is in the range of 3mm - 30mm.

45. The PSU of any of the claims 26 to 40, wherein the PSU is included in a camera, and wherein the camera includes an image sensor having an image sensor diagonal (SD) in the range of 2mm - 25mm.

46. The PSU of claim 45, wherein the SD is in the range of 5mm - 20mm.

47. The PSU of any of the claims 26 to 40, wherein the PSU is included in a mobile device.

48. The PSU of claim 47, wherein the mobile device is a smartphone.

49. A position sensing unit (PSU), comprising: a rectangular magnet having a single magnet polarization (MP); and a magnetic flux measuring device (MFMD), the MFMD configured to measure a magnetic flux B, wherein the magnet is operational to move relatively to the MFMD along a first direction within a linear range L that fulfils 1mm ≤ L ≤ 25mm, wherein the MFMD is positioned at a distanceD away from the magnet along a second direction perpendicular to the first direction, wherein D is in the range of 0.1mm to 3mm, wherein the single MP forms an angle α with an axis parallel to a third direction perpendicular to the first and the second direction, and wherein α = 10 - 80 degrees.

50. The PSU of claim 49, wherein α = 20 - 70 degrees.

51. The PSU of claim 49, wherein α = 30 - 60 degrees.

52. The PSU of claim 49, wherein the single MP is oriented parallel to one of the sides of the rectangular magnet.

53. The PSU of claim 49, wherein the single MP forms an angle α with one of the sides of the rectangular magnet.

54. The PSU of claim 49, wherein D is constant along L.

55. The PSU of claim 49, wherein D is in the range of 0.1mm to 1.5mm.

56. The PSU of claim 49, wherein 1mm ≤ L ≤ 15mm.

57. The PSU of claim 49, wherein 1mm ≤ L ≤ 10mm.

58. The PSU of claim 49, wherein 1mm ≤ L ≤ 5mm.

59. The PSU of any of the claims 49 to 58, wherein the PSU is included in a voice coil motor (VCM) that includes one or more coils.

60. The PSU of claim 59, wherein the VCM is included in smartphone camera.

61. The PSU of any of the claims 49 to 58, wherein the PSU is included in a camera, and wherein the camera includes a lens having an effective focal length (EFL) in the range of 2mm - 50mm.

62. The PSU of claim 61, wherein the EFL is in the range of 3mm - 30mm.

63. The PSU of any of the claims 49 to 58, wherein the PSU is included in a camera, and wherein the camera includes an image sensor having an image sensor diagonal (SD) in the range of 2mm - 25mm.

64. The PSU of claim 63, wherein the SD is in the range of 5mm - 20mm.

65. The PSU of any of the claims 49 to 58, wherein the PSU is included in a mobile device.

66. The PSU of claim 65, wherein the mobile device is a smartphone.

67. A position sensing unit (PSU), comprising: a magnet assembly (MA) having a width W measured along a first direction and a height H measured along a second direction perpendicular to the first direction and including one or more magnets having one or more respective magnetic polarizations; and a plurality of N<100 magnetic flux measuring devices (MFMDs), the plurality of MFMDs positioned along a MFMD axis parallel to the first direction and configured to measure a magnetic flux B generated by the MA, wherein each MFMD has a respective MFMD linear range Li, i = 1, 2, …, N, wherein the plurality of MFMDs is located at a distance D from the MA, D being measured along a third direction perpendicular to the first and the second direction, wherein D is in the range of 0.1mm to 3mm, wherein the MA is configured to move relative to the plurality of MFMDs along the first direction, the position sensing unit having a unit linear range LUnit that fulfils 1mm ≤ LUnit ≤ 25mm, wherein LUnitstarts at a first point x0and ends at a final point xmax, wherein a minimum value Dminof distance D fulfills LUnit / Dmin>10, and wherein at each position along LUnit, at least one MFMD out of the plurality of MFMDs is operated within its linear range Li.

68. The PSU of claim 67, wherein the MA has a symmetry axis parallel to the second direction.

69. The PSU of claim 67, wherein D is not constant for different positions within stroke L.

70. The PSU of claim 67, wherein L / Dmin>15.

71. The PSU of claim 67, wherein L / Dmin>20.

72. The PSU of claim 67, wherein B at x0is B0and B at xmaxis Bmaxand wherein a slope SL = (B0- Bmax) / L is larger than 10mT / mm.

73. The PSU of claim 67, wherein B at x0 is B0 and B at xmax is Bmax and wherein a slope SL = (B0 - Bmax) / L is larger than 50 mT / mm.

74. The PSU of claim 67, wherein B at x0is B0and B at xmaxis Bmaxand wherein a slope SL = (B0 - Bmax) / L is larger than 250 mT / mm.

75. The PSU of claim 67, wherein B at x0 is B0 and B at xmax is Bmax and wherein a slope SL = (B0- Bmax) / L is larger than 2500 mT / mm.

76. The PSU of claim 67, wherein the MA has a left MA domain and a right MA domain along the first direction.

77. The PSU of claim 76, wherein the magnetic polarization of the left MA domain is directed towards the MFMD.

78. The PSU of claim 76, wherein the magnetic polarization of the right MA domain is directed away from the MFMD.

79. The PSU of claim 67, wherein the MA has a left MA domain, a middle MA domain and a right MA domain along the first direction.

80. The PSU of claim 79, wherein the magnetic polarization of the middle MA domain is directed parallel or anti-parallel to the first direction.

81. The PSU of any of the claims 67 to 80, included in a voice coil motor (VCM).

82. The PSU of any of the claims 67 to 80, wherein the MFMD is a Hall sensor.

83. The PSU of claim 79, wherein the symmetry axis is located at a center of the middle MA domain.

84. The PSU of claim 79, wherein a value of D between the left MA domain and MFMD is D(x0), wherein a value of D between the right MA domain and the MFMD is D(xmax), wherein a value of D between the middle MA domain and the MFMD is D(xmax / 2) and wherein D(x0)≤D(xmax / 2) and D(xmax) ≤ D(xmax / 2).

85. The PSU of claim 79, wherein a value of D between the left MA domain and MFMD is D(x0), wherein a value of D between the right MA domain and the MFMD is D(xmax), wherein a value of D between the middle MA domain and the MFMD is D(xmax / 2) and wherein D(x0) = D(xmax) ≤ D(xmax / 2).

86. The PSU of claim 79, wherein the left, middle and right MA domains are rectangular.

87. The PSU of claim 79, wherein the left and right MA domains are trapezoids, and the middle MA domain is a convex pentagon.

88. The PSU of claim 81, wherein the VCM includes four coils.

89. The PSU of claim 81, wherein the VCM is included in smartphone camera.

90. The PSU of claim 79, wherein the MA additionally includes a fourth MA domain and a fifth MA domain having respective magnetic polarizations, wherein the fourth MA domain is located to the left of the left MA domain and wherein the fifth MA domain is located to the right of the right MA domain.

91. The PSU of claim 90, wherein the magnetic polarization of the fourth MA domain is directed away from the MFMD.

92. The PSU of claim 90, wherein the magnetic polarization of the fifth MA domain is directed towards the MFMD.

93. The PSU of claim 67, wherein D is in the range of 0.1mm to 1.5mm.

94. The PSU of claim 67, wherein 1mm ≤ LUnit ≤ 15mm.

95. The PSU of claim 67, wherein 1mm ≤ LUnit≤ 10mm.

96. The PSU of claim 67, wherein 1mm ≤ LUnit≤ 5mm.

97. The PSU of claim 67, wherein L / W > 0.

5.

98. The PSU of claim 67, wherein L / W > 0.

75.

99. The PSU of claim 67, wherein L / H > 3.

100. The PSU of claim 67, wherein L / H > 5.

101. The PSU of claim 67, wherein the at least three magnets are made from a Neodymium based material.

102. The PSU of any of the claims 67 to 88 and 90 to 101, wherein the PSU is included in a camera, and wherein the camera includes a lens having an effective focal length (EFL) in the range of 2mm - 50mm.

103. The PSU of claim 102, wherein the EFL is in the range of 3mm - 30mm.

104. The PSU of any of the claims 67 to 88 and 90 to 101, wherein the PSU is included in a camera, and wherein the camera includes an image sensor having an image sensor diagonal (SD) in the range of 2mm - 25mm.

105. The PSU of claim 103, wherein the SD is in the range of 5mm - 20mm.

106. The PSU of any of the claims 67 to 88 and 90 to 101, wherein the PSU is included in a mobile device.

107. The PSU of claim 106, wherein the mobile device is a smartphone.

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