TECHNICAL FIELD

The present disclosure relates generally to the field of optical devices, and particularly to an actuator assembly device and an aperture system. An actuator assembly device is disclosed which may be used for actuation of an aperture system. The actuator assembly device is based on a Shape Memory Alloy (SMA). Further, an aperture system is disclosed, which may be for a mobile camera. Moreover, the present disclosure also relates to a method of operating the actuator assembly device and a method of operating the aperture system.

BACKGROUND

Generally, an optical device such as a mobile camera may comprise an optical iris aperture. Further, an optical iris aperture may have a variable size, and may be adjusted to control an exposure of light on an image sensor of a mobile camera. For example, in a dark environment, a larger aperture size may be used to shorten an exposure time and to increase a sensitivity of the image sensor. Moreover, in a bright environment, a smaller aperture size may be used, for example, to help increasing a depth-of field, or to reduce an over-saturation of the image sensor. In addition, in a bright environment, a larger aperture size may be used to generate a photographic “bokeh” effect.

A conventional optical device comprises an actuator system that is electromechanically operated, and that has an architecture that separates a wing folding unit and an actuator section unit.

Another conventional device comprises a circular array of separated moving wings or folding wings that are provided on a base. Moreover, a single actuator for the base may be used or a separate actuator may be provided for each wing. A conventional actuator assembly device may be based on a voice coil, a piezoelectric material, or a shape memory alloy. However, an issue of the conventional devices is that they have a low actuation force. Moreover, small sizes of coils and magnets may result in a short interaction range, and thus, a short movement for operating the wings.

SUMMARY

In view of the above-mentioned problems and disadvantages, embodiments of the present disclosure aim to improve conventional actuator assembly devices and aperture systems.

An objective is to provide an actuator assembly device, which may be used for variable aperture systems. Another objective is to provide a miniaturized and an adjustable aperture actuator assembly device that may provide a large aperture change (e.g., in a range between 2 to 5 mm). A further objective is to provide an aperture assembly device that may be easily manufactured and assembled.

A further objective is to provide an aperture assembly device that may be produced with a low part cost and a high production volume. A further objective is to provide an aperture assembly device that may operate in a variety of conditions such as after a physical shock, or at different temperatures.

These and other objectives are achieved by the embodiments of the disclosure as described in the enclosed independent claims. Advantageous implementations of the embodiments of the disclosure are further defined in the dependent claims.

A first aspect of the present disclosure provides an actuator assembly device for an aperture system, the actuator assembly device being connectable to the aperture system and comprising a flexible electrical conductor base, and a first sheet based Shape Memory Alloy (SMA) actuator unit and a second sheet based SMA actuator unit being individually connected to the flexible electrical conductor base, wherein the first sheet based SMA actuator unit and the second sheet based SMA actuator unit are configured to drive the aperture system when the actuator assembly device is connected to the aperture system.

The actuator assembly device may be, or may be incorporated in, electronic device such as a mobile camera, a smartphone camera, or the like. For example, the actuator assembly device of the present disclosure may be based on an SMA, and may be used for a variable aperture system of a smartphone camera.

The electrical conductor base may be any kind of base, for example, it may be a Printed Wiring Board (PWB), a Flexible Printed Circuit (FPC) base member, or a Rigid Flexible Printed Circuit (RFPC) base member.

Moreover, the first sheet based SMA actuator unit and the second sheet based SMA actuator unit may be manufactured from a sheet-based material. By using a sheet-based SMA actuator unit, the actuator assembly device may provide specific characteristics, or it may have a specific shape or structure. For example, the first sheet based SMA actuator unit and the second sheet based SMA actuator unit may be used to construct a U-shaped structure with mechanical coupling in the middle and the end points, and an electrical coupling at the end.

Furthermore, the actuator assembly may have a high power-to-size ratio. This may provide a small and compact external actuator device, which may be used to drive a plurality of blades (e.g., 3 to 10 blades) of an aperture system.

Moreover, the sheet based SMA actuator units of the actuator assembly device may enable a versatile element design with a plurality of integrated functions for different shapes (forms), actuation mechanism, and supports.

Moreover, the first sheet based SMA actuator unit and the second sheet based SMA actuator unit may be individually connected and may be separately controlled. For example, an adhesive tape may be used to individually connect the first sheet based SMA actuator unit and the second sheet based SMA actuator unit to the flexible electrical conductor base. Furthermore, a clockwise and an anti-clockwise rotation may be generated to an actuation wheel. For example, a desired rotation may be obtained by separately actuating each of the first sheet based SMA actuator unit and the second sheet based SMA actuator unit.

In an implementation form of the first aspect, at least one of the first sheet based SMA actuator unit and the second sheet based SMA actuator unit has a flat two-side form and a curved shaped. The flat two-side form may allow each side of the respective SMA actuator unit to be independently operated. Further, each side may be monitored, for example, an internal resistance between a cold side and a hot side may be monitored, and accordingly the actuator assembly device may be controlled. This may benefit the control of self- sensing accuracy of the actuator assembly device.

In a further implementation form of the first aspect, at least one of the first sheet based SMA actuator unit and the second sheet based SMA actuator unit comprises an antagonistic material that is configured to, when being electrically activated, contract the first sheet based SMA actuator unit or the second sheet based SMA actuator unit, respectively.

The antagonistic material may provide a contraction property to the actuator assembly device. For example, the first sheet based SMA actuator unit and/or the second sheet based SMA actuator unit may comprise the antagonistic material that may be manufactured in a form of a non-straight shapes, curved, or wormy-like. Moreover, the path length of he first sheet based SMA actuator unit and/or the second sheet based SMA actuator unit may be increased or maximized.

In a further implementation form of the first aspect, the actuator assembly device further comprising a coupling element connectable to the aperture system; wherein at least one of the first sheet based SMA actuator unit and the second sheet based SMA actuator unit is further configured to control a movement of the coupling element in two directions based on the contraction of the first sheet based SMA actuator unit or the second sheet based SMA actuator unit, respectively.

This may enable the actuator assembly device to generate a longer movement for a plurality of blades (hereinafter also referred to as wings) of the aperture system, for example, a longer movement may be generated without having loss of actuation performance.

In a further implementation form of the first aspect, the actuator assembly device is configured to drive the aperture system by controlling the movement of the coupling element in a linear direction, or along a curved path, or by causing a rotational displacement of the coupling element. This may enable the actuator assembly device to drive the aperture system in different directions.

In a further implementation form of the first aspect, at least one of the first sheet based SMA actuator unit and the second sheet based SMA actuator unit comprises at least two SMA zigzag- arms that, when being electrically activated, execute a two-directional movement.

By using the two SMA zigzag-arms, it may be possible to provide a two directional movement to the first sheet based SMA actuator unit and the second sheet based SMA actuator unit. For example, a contraction movement or a stretching movement may be achieved.

In a further implementation form of the first aspect, the two-directional movement is caused by a contraction of the at least two SMA zigzag-arms.

The actuator assembly device may provide an advantage compared to conventional voice coil actuator devices. For example, the sheet based SMA actuator units may not have an electromagnetic sensitivity or an interference with adjacent Voice-Coil-Motors (VCMs) actuation systems of a mobile camera. This may further increase autofocus and stabilization of a mobile camera.

A second aspect of the disclosure provides an aperture system for a mobile camera, the aperture system comprising an actuator assembly device according to the first aspect or one of the implementation form of the first aspect; a plurality of blades being connected through a coupling element, an electromechanical base connectable to the flexible electrical conductor base of the actuator assembly device; and a terminal interface configured to supply electrical power to the electromechanical base; wherein the first sheet based SMA actuator unit and the second sheet based SMA actuator unit of the actuator assembly device are configured to drive the plurality of blades on the aperture system, when electrical power is supplied to the electromechanical base.

The aperture system may be an aperture unit for an electronic device such as a mobile camera. The aperture system may comprise an aperture assembly device. The aperture assembly device may comprise sheet based SMA actuator units. A thickness of the sheet may be approximately 0.5 mm. This may provide a lightweight actuator the aperture system which may reduce moving many optical elements to enhance focusing and further stabilizing of a mobile camera.

In an implementation form of the second aspect, the aperture system further comprising a housing unit having an internal surface and an external surface; wherein the actuator assembly device is mounted to the internal surface of the housing unit.

In an implementation form of the second aspect, the aperture system further comprising a U- shaped electrical circuitry comprising the actuator assembly device, wherein the U-shaped electrical circuitry provides a U-shaped electrical loop.

This form of implementation generates an electrical circuitry through the U-shaped SMA element and heats up a thinnest or a narrowest portion on the SMA arms which may cause their contraction effect. For example, a typical austenite-martensite phase change for SMA materials may appear.

In an implementation form of the second aspect, the aperture system further comprising a U- shaped electrical circuitry comprising the actuator assembly device and a spring element, wherein the U-shaped electrical circuitry provides a U-shaped electrical loop comprising a first electrical path provided by the actuator assembly device and a second electrical path provided by the spring element.

In an implementation form of the second aspect, the first electrical path and the second electrical path are separated and isolated from each other.

In an implementation form of the second aspect, the electromechanical base comprises at least one of: a Printed Wiring Board (PWB) base member, a Flexible Printed Circuit (FPC) base member, a Rigid Flexible Printed Circuit (RFPC) base member,

In an implementation form of the second aspect, the aperture system further comprising an aperture having an adjustable size range between 2 mm to 5 mm. For example, having the adjustable size range between 2 mm to 5 mm may enable a working within a desired time frame, e.g., a full activation within 0.5 seconds may be obtained. Moreover, a power consumption may be lowered, e.g., in a range between 100- to 200 mW.

In an implementation form of the second aspect, the plurality of blades includes 3 to 10 blades.

A third aspect of the disclosure provides a method of operating an actuator assembly device for an aperture system, the actuator assembly device being connectable to the aperture system, the method comprising providing a flexible electrical conductor base; and providing a first sheet based Shape Memory Alloy (SMA) actuator unit and a second sheet based SMA actuator unit being individually connected to the flexible electrical conductor base; and driving, by the first sheet based SMA actuator unit and the second sheet based SMA actuator unit, the aperture system when the actuator assembly device is connected to the aperture system.

A fourth aspect of the disclosure provides a method of operating an aperture system for a mobile camera, the method comprising providing an actuator assembly device comprising a first sheet based SMA actuator unit and a second sheet based SMA actuator unit; providing a plurality of blades being connected through a coupling element; providing an electromechanical base having a longitudinal and curved form and connectable to the flexible electrical conductor base of the actuator assembly device; providing a terminal interface; supplying, by the terminal interface, electrical power to the electromechanical base; and driving, by the first sheet based SMA actuator unit and the second sheet based SMA actuator unit of the actuator assembly device, the plurality of blades on the aperture system.

It has to be noted that the devices, elements, units and means described in the present application could be implemented in software or hardware elements or any kind of combination thereof. The steps which are performed by the various entities described in the present application, as well as the functionalities described to be performed by the various entities, are intended to mean that the respective entity is adapted to or configured to perform the respective steps and functionalities. Even if, in the following description of specific embodiments, a specific functionality or step to be performed by external entities is not reflected in the description of a specific detailed element of that entity which performs that specific step or functionality, it should be clear for a skilled person that these methods and functionalities can be implemented in respective software or hardware elements, or any kind of combination thereof. BRIEF DESCRIPTION OF DRAWINGS

The above described aspects and implementation forms will be explained in the following description of specific embodiments in relation to the enclosed drawings, in which

FIG. 1 depicts a schematic view of an actuator assembly device for an aperture system, according to an exemplary embodiment of the disclosure;

FIG. 2 depicts a schematic view of an aperture system for a mobile camera, according to an exemplary embodiment of the disclosure;

FIG. 3 depicts a schematic view of an aperture system, according to an exemplary embodiment of the disclosure;

FIG. 4 depicts a schematic view of an aperture system comprising an actuator assembly device, according to an exemplary embodiment of the disclosure;

FIG. 5 depicts a schematic view of an actuator assembly device comprising a sheet based SMA actuator unit having a zigzag arm, according to an exemplary embodiment of the disclosure;

FIG. 6 shows a diagram illustrating executing a two-directional movement by two zigzag-arms of an actuator assembly unit;

FIG. 7 shows a diagram illustrating an actuator assembly unit mounting to a housing unit of an aperture system;

FIG. 8 depicts a schematic view of an aperture system comprising a U-shaped electrical circuitry, according to an exemplary embodiment of the disclosure;

FIG. 9 shows a diagram illustrating an actuator assembly unit mounting to a housing unit of an aperture system; FIG. 10 shows a flowchart of a method of operating an actuator assembly device for an aperture system; and

FIG. 11 depicts a flowchart of a method of operating an aperture system for a mobile camera; according to an exemplary embodiment of the disclosure.

DETAILED DESCRIPTION OF EMBODIMENTS

FIG. 1 shows an actuator assembly device 100 for an aperture system 200, according to an exemplary embodiment of the disclosure.

The actuator assembly device 100 may be an actuator unit for an aperture system of an optical device such as a mobile camera. The actuator assembly device 100 is connectable to the aperture system 200.

The actuator assembly device 100 comprises a flexible electrical conductor base 101.

The actuator assembly device 100 further comprises a first SMA actuator unit 102 and a second sheet based SMA actuator unit 103. The first SMA actuator unit 102 and the second sheet based SMA actuator unit 103 are individually connected to the flexible electrical conductor base 101. For example, the first SMA actuator unit 102 may be separately connected to the flexible electrical conductor base 101. Furthermore, the second sheet based SMA actuator unit 103 may be separately connected to the flexible electrical conductor base 101.

Moreover, the first sheet based SMA actuator unit 102 and the second sheet based SMA actuator unit 103 are configured to drive the aperture system 200 when the actuator assembly device 100 is connected to the aperture system 200.

FIG. 2 depicts a schematic view of aperture system 200 for a mobile camera, according to an exemplary embodiment of the disclosure.

The aperture system 200 comprises an actuator assembly device 100. For example, the aperture system 200 may comprise an actuator assembly device 100 described with respect to FIG. 1. The aperture system 200 further comprises a plurality of blades that are connected through a coupling element 201.

The aperture system 200 further comprises an electromechanical base 202 connectable to the flexible electrical conductor base 101 of the actuator assembly device 100.

The aperture system 200 further comprises a terminal interface 203 configured to supply electrical power to the electromechanical base 202, and wherein the first sheet based SMA actuator unit 102 and the second sheet based SMA actuator unit 103 of the actuator assembly device 100 are configured to drive the plurality of blades on the aperture system 200, when electrical power is supplied to the electromechanical base 202.

In particular, in FIG. 2 a top view of the aperture system 200 is shown. The aperture system 200 of FIG. 2 comprises a longitudinal and curved the electromechanical base 202. The electromechanical base 202 may be a PWB, a FPC, or a RFPC which may be curved shaped during a manufacturing process or by using a flexible material.

Further, two SMA sheet based actuator units 102, 103 are mounted at opposite ends of the electromechanical base 202. These actuators may be individually driven, for generating a linear or a curved displacement on a common coupling member which is operating the folding wing mechanism. Such coupling member is typically a rotating cylindrical element.

The aperture system 200 may be used for a mobile camera of a smartphone. Moreover, the smartphone may be configured to operate, e.g., drive a plurality of blades of the aperture system. For example, the mobile camera may comprise a processing circuitry configured to perform, conduct or initiate the various operations of the aperture system 200 described herein. The processing circuitry of the mobile camera may comprise hardware and software.

FIG. 3 depicts a schematic view of an aperture system 200, according to an exemplary embodiment of the disclosure.

The aperture system 200 comprises a plurality of blades 311, an actuator assembly device 100, and a housing unit 302. The plurality of blades 311 may be driven by the first sheet based SMA actuator unit 102 and the second sheet based SMA actuator unit 10, for example, when the actuator assembly device 100 is connected to the aperture system 200. Further, a variable aperture blade space 301 may be provided.

The actuator assembly device 100 may be connected horizontally, or vertically to the housing unit 302 of the aperture system.

FIG. 3 shows an overall architecture of the variable aperture system 200 showing two implementation possibilities for the actuation assembly unit 100. For instance, the actuation assembly unit 100 may be mounted in different configurations such as a side mounting option or a bottom mounting option.

The actuator assembly device 100 is based on a sheet material SMA. For example, the actuator assembly device 100 may comprise a dual-element type of antagonistic actuation part which may contract based on a pull-pull mechanism, and may be used for operating the plurality of blades 311 of the aperture system 200. For example, the antagonistic material may be configured to, when being electrically activated, contract the first sheet based SMA actuator unit 102 or the second sheet based SMA actuator unit 103, respectively.

The aperture system 200 is not limited to a specific number of blades (hereinafter also referred to as wings) or a specific folding mechanism. For example, the plurality of blades 311 may include 3 to 10 blades. Moreover, the aperture system 200 may provide an aperture having an adjustable size range between 2 mm to 5 mm. Thus, the actuation assembly device 100 and/or the aperture system 200 may be used with most common type of variable aperture units of mobile cameras.

FIG. 4 depicts a schematic view of an aperture system 200 comprising an actuator assembly device 100, according to an exemplary embodiment of the disclosure.

The aperture system 200 of FIG. 4 comprises an actuator assembly device 100, a bottom cover 403, a moving wing unit 401 and a rotating actuation element 402. The actuator assembly device 100 is based on a sheet SMA based that is arranged around a plurality of wings 311 that are in the moving wing unit 401. The actuator assembly device 100 may be connected through a coupling element 201 to the aperture system. The coupling element 201 may be a mechanical coupling element. Furthermore, the actuator assembly device 100 may be used to operate, e.g., rotate, the plurality of blades 311 of the aperture system. For example, the actuator assembly device 100 may be configured to drive the aperture system 200 by controlling the movement of the coupling element 201 in a linear direction, or along a curved path, or by causing a rotational displacement of the coupling element 201. Moreover, the bottom cover 403 may be a cover that is used for closing an assembly of the aperture system 200.

Reference is now made with respect to FIG. 5 which depicts a schematic view of an actuator assembly device 100 comprising a sheet based SMA actuator unit 102, 103 having a zigzag arm, according to an exemplary embodiment of the disclosure.

As discussed, at least one of the first sheet based SMA actuator unit 102 and the second sheet based SMA actuator unit 103 has a flat two-side form and a is curved shaped.

The first sheet based SMA actuator unit 102 and the second sheet based SMA actuator unit 103 of the actuator assembly device 100 comprises two SMA zigzag-arms 511, 512 that, when being electrically activated, execute a two-directional movement.

The actuator assembly device 100 of FIG. 5 comprises the flexible electrical conductor base 101 which may be a curved, longitudinally shaped FPC element comprising electromechanical connection areas 502, 503. Moreover, a first electrical connection point 502 and a second electrical connection point 503 may be provided by electroplating through the holes. Further, the two sheet based SMA actuator units 102, 103 may be attached at two opposite ends, and thereby, a U-shaped structure may be provided. Moreover, mechanical rivets 501 may be used for providing a rivet connection on the FPC 101 in order to obtain electromechanically coupling.

The two sheet based SMA actuator units 102, 103 may be manufactured such that they have non-straight shapes in the form of curved, wormy appearance on sectional areas in order to maximize the path lengths. This may generate an electrical circuitry 805 through the U-shaped SMA elements (i.e., two sheet based SMA actuator units 102, 103) and may heat up a thinnest or a narrowest portions on the SMA arms which may cause their contraction effect.

The actuator assembly device 100 of FIG. 5 comprises electrical terminals out 508, the contractive SMA worm shaped arm 504 having the two SMA zigzag-arms 511, 512, a locking clip for retention 505, and a moving section 506 provided on the SMA actuation arm 504. The power supply to the external control driver IC are carried via FPC.

The contractive, worm shaped, arm 504 may generate displacement for the mid-point of the U- shape unit. Moreover, by measuring the internal resistance of the SMA element, it may be possible to detect its contractive (positional) state during activation (for stroke measurement). This is enabled with the change of sectional area of the SMA element which increases during contraction (as it is shown with arrow 507) and reduces during elongation, and thus creating a change in material’s electrical resistance.

For example, electrical activation of the SMA worm arm element 504 on each side may be contacted. Moreover, by separately activating each of the two SMA zigzag-arms 511, 512, a clockwise and counter-clockwise rotation may be generated to the coupling element. For example, the coupling element 201 may be an actuation wheel which may rotate and may further move the plurality of blades 311.

FIG. 6 shows a diagram illustrating executing a two-directional movement 611, 612 by two zigzag-arms 511, 512 of an actuator assembly unit 102, 103.

As discussed, the first sheet based SMA actuator unit 102 and/or the second sheet based SMA actuator unit 103 of the actuator assembly device 100 may comprise two SMA zigzag-arms 511, 512. Moreover, two SMA zigzag-arms 511, 512 may be electrically activated, and may further execute a two-directional movement 611, 612.

The two-directional movement 611, 612 may be caused by a contraction of the at least two SMA zigzag-arms 511, 512. For example, during a contraction the sectional area of the SMA material may become larger and a two-directional movement 612 may be executed. Moreover, during stretching the sectional area of the SMA material becomes smaller and a two-directional movement 611 may be executed. Reference is now made with respect to FIG. 7 which shows a diagram illustrating an actuator assembly unit 100 mounting to a housing unit 302 of an aperture system 200.

The housing unit 302 has an internal surface and an external surface. Moreover, the actuator assembly device 100 may be is mounted to the internal surface of the housing unit 302.

More specifically, FIG. 7 shows a mounting of the actuator assembly device 100 to the aperture system 200 which integrates the first sheet based SMA actuator unit 102 and/or the second sheet based SMA actuator unit 103 from a side direction to the base of the housing unit 302 of variable aperture system 200. For instance, an adhesive material or a glue may be used in between and the mid-path coupling point of the U-shaped SMAs which may have a metal clip-to-plastic pin retention.

Reference is now made to FIG. 8, which depicts a schematic view of an aperture system 200 comprising a U-shaped electrical circuitry, according to an embodiment of the disclosure.

The aperture system 200 of FIG. 8 further comprises a U-shaped electrical circuitry 805. For example, the U-shaped electrical circuitry 805 may be constructed in a first implementation form 800 A or a second implementation form 800B.

In the implementation form 800A, the U-shaped electrical circuitry 805 comprises the actuator assembly device 100, and provides a U-shaped electrical loop. For example, the U-shaped electrical loop may be formed directly from the actuator assembly device 100, and by shaping during manufacturing process. Areas with narrow or thinner shapes may act primarily for actuation (contraction) procedures, while wider or thicker areas may be used for support and coupling.

In the implementation form 800B, the U-shaped electrical circuitry 805 comprises the actuator assembly device 100 and a spring element 811.

In the implementation form 800B, the U-shaped electrical circuitry 805 provides a U-shaped electrical loop that comprises a first electrical path provided by the actuator assembly device 100 and a second electrical path provided by the spring element 811. For example, in the implementation form 800B, the aperture system may further comprise a first end rivet 803, a second end rivet 801, two sheet based SMA units 102, 103, the RFPC 802 and the U-shaped electrical circuitry 805. For example, the U-shaped electrical loop may be formed partly from the actuator assembly device 100 and partly from flexible conductor (such as spring, FPC or wire) connected together with a rivet along the path. In this case the flexible conductor deforms and follows the movement generated by the actuator assembly device 100. Moreover, multiple sections and coupling points between the elements can be used.

The implementation form 800B is further shown in more detailed on the right side of the FIG. 8, which is implemented for aperture system 200 that is based on a variable iris. RFPC island is used onto which the actuator assembly device 100 is riveted electromechanically via through hole. Moreover, a flexible tail of FPC protruding from the edge of the RFPC is used to form a section on the U-shaped actuation feature.

As can be derived from FIG. 8 and the implementation form 800B, the first electrical path and the second electrical path are separated and isolated from each other.

Reference is now made to FIG. 9, which shows a diagram illustrating an actuator assembly device 100 mounting to a housing unit 302 of an aperture system 200.

FIG. 9 shows another implementation form of mounting the actuator assembly device 100 to a housing unit 302 of the aperture system 200.

The actuator assembly device 100 integrates the SMA based actuation unit from bottom side to the base of the housing unit 302 that also has the plurality of blades 311.

The actuator assembly device 100 may comprise electromechanically rivet connections 905, the U-shaped electrical circuitry 805, a coupling point 902 for a rotational system member, and the PWB actuator 903. Moreover, the aperture system 200 may comprise a plastic pin 901 that is protruding from the actuator assembly device 100. Moreover, an adhesive material or a glue may be used in between and the mid-path coupling point of the U-shaped electrical circuitry 805 having a mechanical, e.g., pin-to-hole, connection to the rotational actuation element 902. Furthermore, rivets (or e.g., metal crimps) may be used between the U-shaped SMA arms and actuator PWB for electromechanical couplings.

FIG. 10 shows a method 1000 of operating an actuator assembly device 100 for an aperture system 200, according to an embodiment of the disclosure.

The method 1000 comprises a steplOOl of providing a flexible electrical conductor base 101.

The method 1000 further comprises a step 1002 of providing a first sheet based Shape Memory Alloy, SMA, actuator unit 102 and a second sheet based SMA actuator unit 103 being individually connected to the flexible electrical conductor base 101.

The method 1000 further comprises a step 1003 of driving, by the first sheet based SMA actuator unit 102 and the second sheet based SMA actuator unit 103, the aperture system 200 when the actuator assembly device 100 is connected to the aperture system 200.

FIG. 11 shows a method 1100 of operating an aperture system 200 for a mobile camera, according to an embodiment of the disclosure.

The method 1100 comprises a stepl lOl of providing 1101 an actuator assembly device 100 comprising a first sheet based SMA actuator unit 102 and a second sheet based SMA actuator unit 103.

The method 1100 further comprises a step 1102 of providing a plurality of blades being connected through a coupling element 201.

The method 1100 further comprises a step 1103 of providing an electromechanical base 202 having a longitudinal and curved form and connectable to the flexible electrical conductor base 101 of the actuator assembly device 100.

The method 1100 further comprises a step 1104 of providing a terminal interface 203.

The method 1100 further comprises a step 1105 of supplying, by the terminal interface 203, electrical power to the electromechanical base 202. The method 1100 further comprises a step 1106 of driving, by the first sheet based SMA actuator unit 102 and the second sheet based SMA actuator unit 103 of the actuator assembly device 100, the plurality of blades on the aperture system 200.

The present disclosure has been described in conjunction with various embodiments as examples as well as implementations. However, other variations can be understood and effected by those persons skilled in the art and practicing the claimed disclosure, from the studies of the drawings, this disclosure and the independent claims. In the claims as well as in the description the word “comprising” does not exclude other elements or steps and the indefinite article “a” or “an” does not exclude a plurality. A single element or other unit may fulfill the functions of several entities or items recited in the claims. The mere fact that certain measures are recited in the mutual different dependent claims does not indicate that a combination of these measures cannot be used in an advantageous implementation.