Electrically adjustable drive for a lens

Abstract

The present invention relates to an electric drive device (1) for moving at least one optical element (2) along the optical axis (3) of a lens. The electric drive device has a statically constructed magnet device (9) as a primary component and a coil-actuator (7, 4) axially movable around the optical axis (3) as a secondary component. The magnet device (9) consists of a plurality of flat magnets (13) symmetrically and uniformly distributed around the periphery, and the coil device (7) consists of a hollow coil body (7) with a polygonal cross-section, the coil body having a plurality of flat, identical surfaces. Section; one or more conductors, which are circumferentially mounted on the surface section in the form of multiple parallel turns of wire at the outer periphery of the coil body (7), and at least one optical element (2) is supported in an actuator (4) arranged within the coil body (7), wherein the number of flat magnets (13) corresponds to the number of surface sections, the edge length (L) of the flat magnets (13) is adapted to the side leg length of the lateral surface section of the coil body (7), and the actuator (4) arranged within the coil body (7) has a connecting element (6) connected to the coil body (7) in the radial direction.

Description

Technical Field

[0001] The present invention relates to an electric drive device for adjusting optical elements along the optical axis of a lens, as described in the preamble of claim 1. Background Technology

[0002] Electric drive devices, implemented in various ways, are known for focusing and focal length adjustment of photographic lenses. Compact small DC motors, ultrasonic motors, and stepper motors with transmission units are primarily used in these applications.

[0003] Similarly, ultrasonic motors are known as driving devices. These motors are designed as ring motors and are arranged around the periphery of the lens mount. Ring motors are mostly configured to drive focusing and focal length adjustment elements in the axial direction using a transmission ratio. Ring motors require complex electronic control at high voltages. Mechanical friction between the stator and rotor generates contaminants inside the lens barrel, and these deposits on the optical elements affect imaging performance.

[0004] A device for changing the axial position of an optical imaging system is known from patent document DE 197 18 189 A1. The optical imaging system is arranged within a support ring, which is guided within a housing in a longitudinally movable manner. Magnetic elements are arranged in the outer circumferential surface of the support ring, following a magnetic field controllably arranged at the outer periphery of the housing, thereby causing the support ring carrying the imaging system to move axially.

[0005] An electromagnetic drive device for axially adjusting an optical imaging system held in a mounting is known from EP 1 884 813 A1. This electric drive device consists of a coil winding parallel to the optical axis of the imaging system and a permanent magnet surrounding the optical axis as an arcuate section. The coil winding and the permanent magnet have a common ferromagnetic circuit. When the coil winding is energized, the coil winding moves through the arcuate section of the permanent magnet, and simultaneously adjusts the lens barrel / mount of the optical imaging system via a pin / slot coupling mechanism guided in a curved support.

[0006] US 2009 / 0237815 A1 discloses a small lens driving device based on the moving coil principle, in which a coil having an octagonal cross-section is partially surrounded by four magnets arranged in the corners of a square module housing. Due to structural limitations, the magnetic force acting on the coil is disadvantageously limited to four segments. This driving device is also known as a voice coil.

[0007] US 2017 / 0023764 A1 discloses a voice coil lens drive module with an autofocus mechanism. The coil used has an octagonal cross-section with asymmetrical, alternating short and long surface sections. Space-saving mounting within a square module housing is achieved by four magnetic elements with trapezoidal cross-sections, which are arranged along the bottom sides of the long surface sections of the coil. The main portion of the coil is not subjected to a magnetic field, resulting in low efficiency, or low motor constant, for this lens drive mechanism.

[0008] A lens driving device without a position sensing device, which detects the position of a lens by induction, is known from patent document JP 2009271204 A. In this device, a coil with an octagonal cross-section is movably arranged in a magnetic field and partially surrounded by a yoke with a U-shaped cross-section. A disadvantage here is that only a portion of the coil's periphery is used to generate motion. To generate a non-uniform magnetic field, the yoke has shorter inner legs and longer outer legs. A flat magnet is arranged at the longer outer legs. The position of the movable coil within the yoke is determined by means of a position recognition circuit. Here, the position recognition circuit detects changes in inductance caused by changes in the relative position of the movable coil with respect to the yoke.

[0009] In the previously mentioned implementation applicable only to small moving masses (such as a single lens in a miniature camera module), the electric drive based on the voice coil principle consists of one or more permanent magnets and a coil with a conductor located in an air gap within a magnetic field. If current flows through the conductor mounted on the coil, the coil moves in the magnetic field of the permanent magnet along a direction orthogonal to the plane formed by the direction of the magnetic field and the direction of the current due to the Lorentz force. The cylindrical electric drive, or voice coil, is constructed according to the so-called moving coil principle, that is, the coil is seated in a magnetic basin. If the coil moves relative to the statically arranged magnetic basin, the magnetic basin is called the primary component of the electric drive, and the coil is called the secondary component. If the coil is statically arranged and the magnet is movable, the coil is called the primary component, and the magnet is called the secondary component. In cylindrical voice coil motors, implementations employing the so-called multi-coil principle are also known, in which the so-called motor constant can be optimized despite a compact structural space. The motor constant is the ratio of the force generated by the magnetic field and current intensity to the power loss. A higher motor constant means less heat is generated due to power loss when producing a predetermined force. Therefore, the motor constant is a measure of the efficiency of a motor in converting electrical energy into kinetic energy. Since the resistance of the conductors on the windings increases with temperature, power loss also increases. For this reason, the motor constant is also temperature-dependent.

[0010] Because the position of the coil body relative to the magnetic field generated by the permanent magnet changes, the force generated by the current flowing into the coil is related to the coil's position. Complex current or voltage control is required to generate a constant or rapid force. To increase the force generated by such an electric drive, the voltage and / or the current intensity can be increased. Both are disadvantageous for mobile applications (such as the electric drive of heavy optical components in lenses), as these applications rely on battery power. Increasing the coil current also necessitates adjusting the coil geometry. This results in a larger coil and increased energy demand. Another disadvantage is the maximum possible current, which is limited by the specifications of the motor drive electronics module due to the structural type.

[0011] Another possibility for increasing the generated force is to increase the magnetic flux density by using larger and stronger magnets. The disadvantage here is that the structural space required for an electrically driven scheme increases disproportionately, and, for example, compact lenses and small focusing assemblies are hindered even with lenses containing large lenses. Summary of the Invention

[0012] The object of this invention is to optimize or improve the motor constant in terms of force and efficiency for electric drive devices known in the prior art, such as those based on the voice coil principle. Another object is to maintain a compact structural space for the drive device while keeping current requirements constant or decreasing, thus enabling its use in large photographic lenses.

[0013] In the type of electric drive device described at the beginning, the objective is achieved by the features described in claim 1, and advantageous improvements are the subject of the dependent claims. Another embodiment based on the same inventive measure is the subject of the parallel independent claim 10.

[0014] The main insight of this invention lies in maximizing, or optimizing, the length of the conductor in the magnetic field acting on the coil at each axial movement position of the coil. A further aspect of this invention is optimizing the orthogonality of the magnetic field acting on the coil length, which generates the Lorentz force, along the entire axial movement path of the coil body, thereby making it as perpendicular as possible to the conductor orientation of the coil, in order to optimize the resultant force generated in the axial direction or the optical axis direction.

[0015] To enable the optical elements to move along the optical axis of the lens, the electric drive device according to the invention has a statically constructed magnet device as the primary component of the motor. As the secondary component of the motor, a coil-actuator, configured for axial movement and centered on the optical axis, is provided, wherein one or more optical components, such as the focusing element of a lens, are supported. The magnet device comprises a plurality of flat magnet elements symmetrically and uniformly distributed around the periphery. The coil device consists of hollow coil bodies with a polygonal cross-section, each coil body having a plurality of flat, identically sized surface sections. According to the invention, the number of flat magnets corresponds to the number of surface sections. Advantageously, the edge length L of the flat magnets is adapted to the side length L' of the surface section of the coil body, and is between 10% larger or smaller than the side length L' of the surface section (L = L' ± 10%L'). On the surface sections, one or more conductors, composed of a plurality of parallel turns of wire, are mounted circumferentially on the outer periphery. An actuator with an optical element to be moved is arranged within a coil body. According to the invention, the actuator arranged within the coil body has multiple connecting elements, such as connecting plates / plates, in the radial direction that connect to the coil body. In this way, a stable, compact, and torsional-resistant connection is established between the actuator and the coil body, enabling greater mass movement. In a particularly material-saving embodiment, a conductor mounted circumferentially on the outer periphery is wound circumferentially around the end of a connecting plate extending in a direction parallel to the optical axis, such that a surface section of the coil body is formed by a plurality of approximately 200 parallel conductor turns. If current flows through the conductor in one direction, the actuator with the optical element moves in that direction due to the Lorentz force, causing the coil device to move axially in that direction within the magnet device, in the form of a moving coil or voice coil. If current flows through the conductor in another direction, the coil device moves axially in that direction together with the actuator and the optical element.

[0016] In a particularly advantageous manner, the flat magnets are arranged parallel to the surface sections of the coil body with a narrow air gap, that is, with a distance less than the material thickness of the coil body, wherein a flat magnet is arranged in each surface section inside the yoke.

[0017] According to the invention, the yoke forms a main magnetic circuit with equal-length side legs, the side legs serving as the inner and outer portions of the main magnetic circuit or the yoke. In this way, the yoke or main magnetic circuit completely surrounds the surface section of the coil body. In this way, the magnet device advantageously forms a uniform, orthogonal magnetic field passing through the surface section of the coil body. For this purpose, each surface section is provided with a yoke. In one or more yokes with one side open, or in a yoke device formed by multiple yokes arranged concentrically around the optical axis, it is advantageous that the coil body can be introduced during manufacturing and for assembly purposes.

[0018] The uniformity and direction of the magnetic field acting on the coil section are advantageously ensured by the fact that the flat magnets have the same polarization in the radial direction.

[0019] Here, depending on the structural space required for or available for the electric drive device according to the invention, flat magnets are selectively arranged in the yoke at the inner or outer portion of the main magnetic circuit. To generate a particularly strong magnetic field, a pair of co-polarized flat magnets can be arranged in the yoke. In this case, advantageously, one flat magnet is partially disposed, specifically fastened to the inner portion of the main magnetic circuit by adhesive bonding, while the other flat magnet is partially disposed, specifically fastened to the outer portion of the main magnetic circuit by adhesive bonding.

[0020] To advantageously and further improve the uniformity of the magnetic field generated in the coil's movement space, a secondary magnetic circuit is provided on the open side of the yoke, connecting the inner and outer portions of the main magnetic circuit. In this way, a uniform magnetic field orthogonal to the direction of movement is generated within the maximum axial movement range of the coil body carrying the conductor.

[0021] In a particularly compact embodiment of the electric drive, the length of the cross-sectional edge of the coil section facing the coil body of the inner portion of the corresponding main magnetic circuit (inner leg of the yoke) is smaller than the length of the edge of the flat magnet disposed on the inner surface of the outer portion of the corresponding main magnetic circuit (outer leg of the yoke). A particularly uniform and uniform magnetic field can be generated by a single yoke in which the cross-sections of the outer and inner portions of the main magnetic circuit are configured to have the same area. In this case, the inner portion of the main magnetic circuit has a larger radial thickness than the outer portion of the main magnetic circuit despite its smaller edge length. In this way, a compact external dimension of the entire electric drive can also be achieved.

[0022] According to the present invention, for linearly guiding the actuator, two statically arranged guiding systems, radially opposed to each other and parallel to the optical axis, are provided between the coil body and the light-transmitting aperture of the actuator. These systems preferably serve as guide rods for a secondary component (an actuator with optical elements) that can move axially. Therefore, the radial distance of the guide rod from the optical axis is less than the radial distance of the surface section of the coil body from the optical axis, or less than the radial distance of the coil from the optical axis. One of the guide rods serves as a support system on which the actuator is linearly guided in a radially clear and unbiased orientation parallel to the optical axis. One guide rod is oriented parallel to the optical axis and forms a sliding support structure for the actuator in this manner. On the second guide rod, the actuator is further guided by an elongated hole constructed in the actuator in the radial direction, thereby preventing oscillating movement about the opposing sliding guide axes. In this way, over-positioning supports that could cause jamming are avoided, and linear guidance of the optical elements along the optical axis is ensured.

[0023] Particularly advantageously, the guiding system is constructed as a guide rod and is arranged space-savingly between every two adjacent legs of the inner portion of the main magnetic circuit. To avoid limiting the aperture for the optical element, the radial distance of the guide rod from the optical axis corresponds to the radial distance of the inner portion of the main magnetic circuit from the optical axis. The inner portions of the main magnetic circuit arranged on the left and right sides of the guide rod (the inner legs of the yoke) here have smaller edge lengths or cross-sectional widths than the rest of the inner portions of the main magnetic circuit.

[0024] In an embodiment of the electric drive device according to the invention, particularly suitable for the electric drive of lenses, the coil body has six, eight, ten, or twelve surface segments. Advantageously, the coil body is formed of a plurality of conductive coils that are substantially parallel to each other and extend circumferentially. The hollow actuator has connecting elements arranged uniformly around its periphery, corresponding to the number of surface segments. These connecting elements are implemented as narrow bridge-shaped portions, and the conductive coils are supported at an angle on the outer ends of the connecting elements. For the coil body, a hexagonal cross-section has proven particularly advantageous, in which the individual parallel conductors are supported at an angle of 120° at the bridge-shaped portions of the connecting elements. The surface segments are at an angle of 120° to each other. In another advantageous configuration, particularly suitable for forming an optimized uniform magnetic field, the coil body has an octagonal shape in cross-section with an interior angle of 135° between each other. Accordingly, during the manufacture of the coils, the conductors are bent at an angle of 45° at the bridge-shaped portions around the periphery of the hollow actuator.

[0025] According to the present invention, the force and efficiency of the electric drive device for use in large photographic lenses are successfully optimized through the combined effect of the aforementioned measures. A constant magnetic flux density of 0.5 to 0.6 Tesla is successfully generated in the gaps of the yoke by using 200 turns of a best-coordinated conductor and a flat magnet with a remanent flux density between 0.8 and 1.6 Tesla, preferably 1.4 Tesla. The coils arranged in the constant, uniform, strong magnetic field generated in this way increase the motor constant, allowing the mass to be moved at a speed suitable for autofocus applications with a maximum of 4 N (Newtons). For example, a movable mass of up to 100 grams can be accelerated at 4 m / sec². In this way, application in large photographic lenses is achieved while maintaining a compact structural space. The current requirement is comparable to conventional devices, and can even be optimally reduced using the described device. Attached Figure Description

[0026] An embodiment of the electric drive device according to the invention is schematically shown in the figures, and the embodiment is described in more detail below with the aid of the figures.

[0027] In the attached diagram: Figure 1 A longitudinal section of the electric drive unit is shown. Figure 2a A cross-section of the electric drive unit is shown. Figure 2b It shows Figure 2a Partial illustration in the image. Figure 3 A diagram along the optical axis is shown, along with a schematic representation of the secondary magnetic circuit. Figure 4 A cross-section of a magnet device having a pair of flat magnets that are co-polarized is shown. Figure 5 It shows a SN SN polarization mode Figure 4 Partial view X in the image. Detailed Implementation

[0028] exist Figure 1 In the electrically driven device 1, schematically shown in longitudinal section, an optical element 2 with an optical axis 3 is supported in an actuator 4. The actuator 4 is configured to be axially movable and has a [missing information - likely a lens 2 shown schematically] in the region of the optical element 2. Figure 2a The connecting elements 6 shown connect the actuator 4 to the coil body 7. The connecting elements 6 are constructed as ribs, pointing radially outward and extending longitudinally in the axial direction between the actuator 4 and the coil body 7. The connecting elements 6 here have… Figure 2aThe outwardly pointing contact edge 8 shown extends parallel to the optical axis 3 and serves to support the coil body 7, specifically the coil body's coil turns composed of conductors not shown in detail. The length of the contact edge 8 corresponds to the width B defined in the axial direction of the coil body 7, specifically to the width of the conductors that are wound side-by-side and overlapped on the contact edge 8. Figure 1 A statically constructed magnet device 9 is also shown, which in particular consists of a yoke that forms a main magnetic circuit 10 in a U-shape in cross-section. The main magnetic circuit 10 has an inner magnetic portion 11 and an outer magnetic portion 12. A coil 7 and a flat magnet 13 are arranged between the inner portion 11 and the outer portion 12 of the main magnetic circuit 10. One or more flat magnets 13 can be fastened to the outer portion 12 of the main magnetic circuit 10 by an adhesive connection (not shown further). The inner portion 11 of the main magnetic circuit 10 is arranged to face the optical axis 3, thereby surrounding the actuator 4 in the region of the lens 2. The inner portion 11 and the outer portion 12 form equal-length legs of the U-shaped yoke. The open ends of the U-shaped yoke of the main magnetic circuit 10 for assembly purposes cover a secondary magnetic circuit 14, which connects the inner portion 11 and the outer portion 12 of the main magnetic circuit. Based on its function, the actuator 4 can be divided into a coil actuator section 5 and a sensor actuator section 15. The sensor actuator section is connected to the coil actuator section in the axial direction and extends outside the magnet device 9. The coil actuator section 5 here has a mounting base for the optical element 2, and is connected to it via the connecting element 6 (see above) as described above. Figure 2a It is connected to a coil 7 composed of multiple conductors (not shown further). A separate position sensing device ensures axial displacement of the actuator 4 relative to the statically arranged magnet device 9. Figure 1A sensor scale 16, schematically shown at the sensor actuator section 15, and a sensor 17 arranged stationary relative to the sensor scale are formed. Advantageously, a magnetoresistive absolute sensor scale 16 (MR sensing device 16 / 17) with a space-saving construction is used. Since it is arranged outside the coil actuator section 5 and thus outside the strong magnetic field of the magnet device 9, the functionality of the sensor scale is not interfered with. Of course, other position sensing devices are also feasible, such as a magnetoresistive incremental encoder. In this case, the sensing device needs to be calibrated not only during manufacturing but also every time the motor is turned on, in which the front and rear end positions of the actuator 4 are detected. The advantage of the grating scale is that the position sensing device is not affected by the strong magnetic field of the magnet device 9. In this way, the axial position of the actuator 4 relative to the static magnet device 9 can be reliably determined. A front damper 18, schematically shown, is arranged at the end side of the coil actuator section 5. The front damper has a front stop 19 that can be adjusted in the axial direction. The front damper 18 with the front stop 19 can also be composed of multiple dampers 18 distributed around the end periphery of the actuator 4. An equivalent rear damper 18' is provided in the opposite end region of the sensor actuator section 15, the rear damper having an associated rear stop 19' that is adjustable in the axial direction. Advantageously, this prevents the coil body 7 from colliding with the main magnetic circuit 10 or the auxiliary circuit 14 at the front and rear ends of the maximum axial movement path. Impact noise can be prevented in the corresponding final position of the actuator 4 when the coil 7 is not energized.

[0029] exist Figure 2a In the example shown, the polarization direction of the magnetic field is indicated by S and N in two of the flat magnets 13. This polarization direction is applicable to... Figure 2a All flat magnets 13 are schematically shown in the diagram. Figure 2a In the upper region, a guide rod 20, oriented parallel to the optical axis 3, is shown for axial linear guidance of the actuator 4. In the lower region, other guide rods 20', oriented parallel to each other, are arranged radially opposite each other. To ensure the aperture of the lens 2 is as large as possible, the guide rods 20 / 20' are arranged at a distance from the optical axis 3 that is, on the one hand, less than the radial distance of the edge 8 of the contact plate, and on the other hand, greater than the radius of the lens 2. Figure 2a In an embodiment not shown, all inner portions 11 of the main magnetic circuit are identical and arranged at a distance from the optical axis 3 that is greater than the radial distance of the guide rods 20 / 20' from the optical axis 3. The distances of the guide rods 20 / 20' from the optical axis 3, corresponding to the distances of the inner portions 11 of the main magnetic circuit from the optical axis 3, are particularly space-saving and ensure that the aperture for the lens 2 is as large as possible.

[0030] To illustrate the dimensional design of the inner portion 11 of the main magnetic circuit, in Figure 2b It shows Figure 2a The enlarged view shows a portion of the main magnetic circuit. The inner portion 11' of the main magnetic circuit arranged adjacent to the left side of the guide rod 20 has a smaller cross-sectional edge length l' facing the coil 7 than the cross-sectional edge length l of the other inner portion 11 of the main magnetic circuit. Figure 2a The inner portion 11' of the main magnetic circuit adjacent to one of the guide rods 20 / 20', shown accordingly, has a smaller cross-sectional edge length l' than the remaining inner portions 11 of the main magnetic circuit, which are configured with larger cross-sectional edge lengths l to optimize magnetic field uniformity. Between the dimension line of the edge length L of the flat magnet 13 and the leg length L' of a surface segment of the coil body 7, the cross-section 21 of the magnetic action of the outer portion 12 of the main magnetic circuit is shown. Ideally, the cross-section 21 of the magnetic action of the outer portion 12 of the main magnetic circuit corresponds to the cross-section 22 of the magnetic action of the inner portion 11 of the main magnetic circuit. Because the cross-sectional edge length l' of the inner portion 11' of the main magnetic circuit adjacent to the guide rod 20 is smaller, this inner portion has a cross-sectional geometry such that the cross-sectional geometry of the magnetic action 22' corresponds to the cross-sectional geometry of the magnetic action of the remaining inner portions 11 of the main magnetic circuit.

[0031] To further illustrate the structure of the electric drive device 1 according to the present invention, in Figure 3 The diagram shows a view along the optical axis 3, schematically illustrating the secondary magnetic circuit 14. In the cross-sectional view, the connecting element 6, arranged between the coil actuator portion 5 and the coil 7, is also visible. The coil 7 is wound around the edge 8 of the contact plate at its outer periphery. The lens 2, having the optical axis 3, is supported in the mounting base 5. Adjacent to the guide rod 20 / 20', the inner portion 11' of the main magnetic circuit, having a smaller cross-sectional edge length l', is visible.

[0032] exist Figure 4 A variant of the electric drive device 1 according to the invention is shown, which has two flat magnet pairs 13', 13" as flat magnets for each surface segment of the coil body 7. For clarity, Figure 4Not all features are labeled with reference numerals. Two flat magnet pairs 13' and 13" are arranged in a U-shaped yoke at the inner portions 11 and 11' and the outer portion 12 of the main magnetic circuit. A coil 7 is arranged between the flat magnet pairs 13' and 13" with a narrow air gap. The corresponding air gap between the coil 7 and the flat magnet pair 13' or flat magnet pair 13" is less than the radial thickness of the coil 7. The edge length of one flat magnet portion 13" (or the first flat magnet pair 13") is adapted to the side length L' of a surface segment of the coil body 7, and is arranged and fixed, for example by means of adhesive technique, at the outer portion 12 of the main magnetic circuit. The edge length of another flat magnet portion 13' (or the second flat magnet pair 13') is adapted to the cross-sectional edge length l, l' of the surface segment of the inner portions 11, 11' of the main magnetic circuit facing the coil body 7, and is arranged and bonded at that portion. Therefore, the edge length (l, l') of the inner second flat magnet pair is less than the edge length (L') of the first flat magnet pair 13" at the outer portion 12 of the main magnetic circuit.

[0033] exist Figure 5 The image shows a magnified detail of the scene. Figure 4 The portion marked with X in the diagram. The polarization of the magnet pairs 13' and 13" alternates from the inside out, thus creating the following structure from the inside out: the inner portion 11' of the main magnetic circuit; the small second flat magnet pair 13' with polarity SN; the surface section of the coil body 7; the large first flat magnet pair 13" with polarity SN; and the outer portion 12 of the main magnetic circuit. It is also possible to have opposite polarities from the inside out, i.e., NS in the small second flat magnet pair and NS in the large first flat magnet pair.

[0034] List of reference numerals

[0035] 1 Electric drive unit

[0036] 2 Optical elements / lenses

[0037] 3 optical axes

[0038] 4 Actuating devices

[0039] 5. Coil Actuator Section / Mounting Base

[0040] 6 connecting elements

[0041] 7 coil body / coil

[0042] 8-piece edge

[0043] 9 Magnet Device

[0044] 10 Main Magnetic Circuit

[0045] 11, 11' inner part of the main magnetic circuit

[0046] 12. The outer part of the main magnetic circuit

[0047] 13 Flat magnets

[0048] 13' and 13" flat magnets for partial

[0049] 14 magnetic circuits

[0050] 15 Sensor Actuator Section

[0051] 16-sensor scale

[0052] 17 sensors

[0053] 18 / 18' front damper / rear damper

[0054] 19 / 19' Front stop / Rear stop

[0055] 20 / 20' guide bar

[0056] 21 Magnetic action surface of the outer part of the main magnetic circuit

[0057] 22, 22' Magnetic working surface of the inner part of the main magnetic circuit

[0058] Width of coil body 7 (B)

[0059] The edge length of the L-flat magnet

[0060] The side length of the surface section of the L' coil body

[0061] The length of the cross-sectional edge of the inner portion 11, 11' of the main magnetic circuit l, l'

Claims

1. An electric drive device (1) for moving at least one optical element (2) along the optical axis (3) of a lens, the electric drive device having a statically constructed magnet device (9) as a primary component, and a coil-actuator (7, 4) axially movable around the optical axis (3) as a secondary component, wherein, The magnet device (9) includes a plurality of flat magnets (13) symmetrically and uniformly distributed around the periphery; the coil device (7) includes a hollow coil body (7) with a polygonal cross-section, the coil body having: a plurality of flat, identical surface sections; one or more conductors mounted circumferentially on the surface sections around the periphery of the coil body (7) in the form of a plurality of parallel turns of wire; the at least one optical element (2) is supported in an actuating device (4) arranged inside the coil body (7); characterized in that... - The number of flat magnets (13) corresponds to the number of surface segments. - The edge length (L) of the flat magnet (13) is matched with the side length of the surface section of the coil body (7), and - The actuator (4) arranged inside the coil body (7) has a connecting element (6) connected to the coil body (7) in the radial direction.

2. The electric drive device (1) according to claim 1, characterized in that, The connecting element (6) constructed in the radial direction extends in the axial direction and is constructed in a rib-like manner between the actuator (4) and the coil body (7).

3. The electric drive device (1) according to claim 2, characterized in that, The bridge-shaped connecting element (6) has an outwardly pointing tab edge (8) that extends parallel to the optical axis (3), and the conductive coil of the coil body (7) is attached to the tab edge (8).

4. The electric drive device (1) according to any one of claims 1 to 3, characterized in that, A position sensing device (16, 17) is provided for determining the axial displacement of the actuator (4) relative to the magnet device (9), the position sensing device having a sensor scale (16) and a sensor (17).

5. The electric drive device (1) according to any one of claims 1 to 4, characterized in that, A flat magnet (13) is arranged in a manner parallel to the surface section of the coil body (7) in a manner having an air gap within the yoke that forms the main magnetic circuit (10), the yoke having side legs of equal length as the inner part (11, 11') and the outer part (12) of the main magnetic circuit.

6. The electric drive device (1) according to claim 5, characterized in that, Flat magnets (13) have the same polarization direction in the radial direction.

7. The electric drive device (1) according to claim 5 or 6, characterized in that, The flat magnet (13) is arranged in the yoke at the inner part (11, 11') or the outer part (12) of the main magnetic circuit, or the flat magnet is constructed as a pair of flat magnets (13', 13") with the same polarization, wherein one flat magnet part (13') is arranged at the inner part (11, 11') of the main magnetic circuit and the other flat magnet part (13") is arranged at the outer part (12) of the main magnetic circuit.

8. The electric drive device (1) according to any one of claims 2 to 7, characterized in that, On the open side of the yoke, a secondary magnetic circuit (14) is arranged to connect the inner part (11, 11') of the main magnetic circuit with the outer part (12), so that the maximum axial movement range of the coil body (7) with the conductor has a uniform magnetic field orthogonal to the direction of movement.

9. The electric drive device (1) according to any one of claims 2 to 8, characterized in that, The length of the cross-section edge (l, l') of the surface section of the inner part (11, 11') of the main magnetic circuit facing the coil body (7) is smaller than the length of the edge (L) of the flat magnet (13).

10. The electric drive device (1) according to any one of claims 2 to 9, characterized in that, Two radially opposed guide systems (20, 20') are arranged parallel to the optical axis (3). The guide systems are for secondary components that are axially movable and are configured as actuators (4). The radial distance of the guide systems from the optical axis is less than the radial distance of the surface section of the coil body (7).

11. The electric drive device (1) according to claim 10, characterized in that, The guiding system (20, 20') is arranged between every two adjacent legs of the inner portion (11, 11') of the main magnetic circuit at a radial distance relative to the optical axis (3).

12. The electric drive device (1) according to any one of the preceding claims, characterized in that, The coil body (7) has six, eight, ten or twelve surface sections.

13. An electric drive device for moving at least one optical element along the optical axis of a lens, the electric drive device having a statically configured magnet device as a primary component and a coil device configured to move axially around the optical axis as a secondary component, wherein, The magnet device consists of annular segments magnetized radially outward or radially inward, and the coil device consists of hollow cylindrical coil bodies. Each coil body has one or more conductors arranged on the periphery of the coil body in the form of multiple parallel turns of wire. The magnetized annular segments are arranged concentrically with the cylindrical coil bodies within at least two yokes forming the main magnetic circuit, with a narrow air gap. The yokes have side legs of equal length in the axial direction as the inner and outer portions of the main magnetic circuit.

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