WO2022017595A1

WO2022017595A1 - Single-piece actuator and adjustable aperture unit comprising a single-piece actuator

Info

Publication number: WO2022017595A1
Application number: PCT/EP2020/070610
Authority: WO
Inventors: Marko Eromaki
Original assignee: Huawei Technologies Co., Ltd.
Priority date: 2020-07-22
Filing date: 2020-07-22
Publication date: 2022-01-27
Also published as: CN116113877A

Abstract

A single-piece actuator (1) for displacing a plurality of movable elements (8), the single-piece actuator (1) comprising a plurality of fastening areas (2) configured to be fastened by means of at least one first fastening element (13), wherein such fastening enables the fastening areas (2) to remain stationary during actuation. The single- piece actuator (1) further comprises a plurality of actuating arms (4) and a plurality of displacement areas (3) configured to move during actuation, with regards to the fastening areas (2). Each displacement area (3) is configured to be mechanically interconnected with one of the movable elements (8). Each actuating arm (4) extends from one fastening area (2) to one displacement area, and is configured to deform in response to electric and/or magnetic activation by means of the one fastening area (2). The one displacement area (3) is moved in response to the deformation. This allows displacement of several moveable elements (8) by means of only one single-piece actuator (1), reducing the number of components needed and hence freeing up space for other components and/or facilitating reducing the size of a device comprising the single-piece actuator (1), such as the optical system of a smart handset camera.

Description

SINGLE-PIECE ACTUATOR AND ADJUSTABLE APERTURE UNIT COMPRISING A

SINGLE-PIECE ACTUATOR

TECHNICAL FIELD

The disclosure relates to a single-piece actuator, an adjustable aperture unit comprising the single-piece actuator, and an electronic device comprising the adjustable aperture unit and a main board.

BACKGROUND

Small electronic devices such as smart handsets are oftentimes provided with cameras. It is advantageous if the user of the device is able to adjust the size of the optical iris aperture of the camera, in order to adjust the amount of light reaching the image sensor. Under low illumination circumstances, e.g., a larger sized aperture can be used to shorten exposure time and increase sensitivity. Under higher illumination circumstances, a smaller sized aperture ensures increased depth-of-field and reduce oversaturation, while a large aperture helps to generate a photographic bokeh effect, i.e. a soft out-of-focus background.

Professional photography devices are provided with adjustable aperture units which have relatively large sizes and complex architecture, and which are expensive. When attempting to downscale such solutions for smaller devices such as smartphones, the complexity grows and becomes a limiting technical factor, affecting the weight, size, thickness, and reliability of the device, as well as production capability and unit cost. Therefore, small device cameras mainly comprise simple switchable, on/off type, twin-apertures, i.e. aperture units which are not freely adjustable.

SUMMARY

It is an object to provide an improved actuator and an improved aperture unit comprising the actuator. The foregoing and other objects are achieved by the features of the independent claims. Further implementation forms are apparent from the dependent claims, the description, and the figures.

According to a first aspect, there is provided a single-piece actuator for displacing a plurality of movable elements. The single-piece actuator comprises a plurality of fastening areas configured to be fastened by means of at least one first fastening element, wherein such fastening enables the fastening areas to remain stationary during actuation, a plurality of displacement areas configured to move during actuation, with regards to the fastening areas, each displacement area being configured to be mechanically interconnected with one of the movable elements, and a plurality of actuating arms, each actuating arm extending from one fastening area to one displacement area. Each actuating arm is configured to deform in response to electric and/or magnetic activation by means of the one fastening area, and the one displacement area is moved in response to this deformation.

This solution is simple and comprises a minimum of components, making it cost efficient to produce and reliable in use. The size of the actuator can be minimized due to the actuation being implemented electrically or magnetically instead of mechanically. Furthermore, it allows displacement of several moveable elements by means of only one actuator, reducing the number of components needed and hence freeing up space for other unrelated components and/or allowing the size of the device comprising the actuator to be reduced.

In a possible implementation form of the first aspect, each displacement area is located between two fastening areas, two actuating arms extending from the displacement area in different directions, each actuating arm extending towards one of the two fastening areas. This allows actuation of one or two actuating arms by means of activation through only one fastening area.

In a further possible implementation form of the first aspect, the actuating arm is configured to return to an at least partly non-deformed shape and/or deform further in response to a change in the electric or magnetic activation. This keeps the amount of energy required to operate the actuator to a minimum while maximizing its flexibility.

In a further possible implementation form of the first aspect, the electric activation comprises supplying current to the actuating arm by means of the fastening area.

In a further possible implementation form of the first aspect, changing the electric activation comprises changing the strength of the current, i.e. increasing or reducing the strength of the current, and electric deactivation comprises not supplying any current at all to the fastening area. In a further possible implementation form of the first aspect, the movable elements are displaced in a first plane, and the single-piece actuator extends within a second plane, the second plane being parallel with the first plane. This kind of parallel actuation movement and element movement allows for very small dimensions, at least in directions perpendicular to the planes of movement.

In a further possible implementation form of the first aspect, the single-piece actuator forms a closed loop extending in the second plane, making the single-piece actuator as small as possible while still allowing actuation which can generate displacement of several movable elements.

In a further possible implementation form of the first aspect, the deformation of the actuating arm generates deformation of a circumference of the single-piece actuator.

In a further possible implementation form of the first aspect, the single-piece actuator is configured to actuate the plurality of movable elements simultaneously, sequentially, and/or independently, maximizing the flexibility of the actuator and the possible movements of the movable elements.

In a further possible implementation form of the first aspect, the single-piece actuator comprises a shape memory material, the shape memory material having a one-way shape memory effect or a two-way shape memory effect. This allows provision of a very small, flexible, and reliable actuator.

In a further possible implementation form of the first aspect, the actuating arm comprises a plurality of linear segments, each segment extending at an angle against adjacent linear segments, allowing deformation of the actuating arm within the second plane.

According to a second aspect, there is provided an adjustable aperture unit comprising the single-piece actuator according to the above and a plate element comprising a peripheral frame circumscribing a plurality of wings extending in the first plane, the wings being configured to delimit an aperture area formed at a center of the plate element. At least one of the plurality of wings is configured to move from a first position to a second position in the first plane in response to the actuation of the single-piece actuator, thereby generating a change in size of the aperture area. This solution requires a minimum of components, making it cost efficient to produce and reliable in use. The size of the actuator, in particular the thickness, can be minimized due to the plate shape of the aperture delimiting element, and due to the single-piece actuator. Furthermore, the adjustment of the aperture area is flexible due to the flexible wing movement.

In a possible implementation form of the second aspect, the aperture area has an annular outline, corresponding to a standard aperture configuration.

In a further possible implementation form of the second aspect, the plate element is superimposed onto the single-piece actuator such that the first plane of the plate element extends in parallel with the second plane of the single-piece actuator. The thickness of the aperture unit is minimized by means of such a configuration.

In a further possible implementation form of the second aspect, each wing is connected to the peripheral frame by means of a resilient connection arm, each wing being movable around a center of rotation, in the first plane, by means of the resilient connection arm. This allows each wing to be displaced independently of the other wings.

In a further possible implementation form of the second aspect, the resilient connection arm returns to the first position, from the first position, by means of the resilience of the resilient connection arm, removing the need for separate return control or return inducing components.

In a further possible implementation form of the second aspect, the single-piece actuator is connected to the plate element by means of a plurality of second fastening elements, each second fastening element being connected to one wing of the plate element. This facilitates individual connection between the single-piece actuator and each wing, and hence individually activated movement of each wing.

In a further possible implementation form of the second aspect, the second fastening elements are electrically non-conductive, such that the wings remain unaffected by any current supplied to the single-piece actuator, with the exception of the movement generated via the first fastening elements. In a further possible implementation form of the second aspect, the plate element comprises a sheet material, preferably made of stainless steel.

In a further possible implementation form of the second aspect the wings are configured to partially overlap in response to the change in size of the aperture area, each wing comprising a section configured to not collide with an adjacent wing when overlapping. This is a simple solution for reducing the size of the aperture area without complex movements or components.

In a further possible implementation form of the second aspect, the section is stepped or tilted with regards to the remainder of the wing, such that the section does not extend in the first plane.

In a further possible implementation form of the second aspect, the peripheral frame comprises a polygonal outline, preferably rectangular, the outline being unaffected by the actuation of the single-piece actuator. This allows the actuator unit to be moved linearly, e.g. along with a lens group, inside the optical system of a smart handset camera.

In a further possible implementation form of the second aspect, the aperture unit further comprises an additional single-piece actuator, the single-piece actuators extending in parallel. This allows for additional, or counteracting, movement of the movable elements, since one of the single-piece actuators can generate displacement from a first position to a second position, while the other single-piece actuator can generate either additional displacement from the second position to a third position, or reverse displacement from the second position back to the first position.

According to a third aspect, there is provided an electronic device comprising the adjustable aperture unit according to the above, and a main board comprising a structure for current supply. The single-piece actuator of the adjustable aperture unit is connected to the main board by means of the plurality of first fastening elements, each first fastening element being located between two second fastening elements, and the single-piece actuator being arranged between the main board and the plate element of the adjustable aperture unit. This allows for a very compact assembly of adjustable aperture unit and main board, as well as simple and direct actuation of the single-piece actuator. This, in turn, frees up space for other unrelated components and/or allows the size of the electronic device to be reduced.

In a possible implementation form of the third aspect, the first fastening elements are electrically conductive and configured to transmit current from the main board to the fastening areas of the single-piece actuator, such that the fastening areas are electrically activated. This allows for direct, simple, and reliable actuation of the single-piece actuator.

In a further possible implementation form of the third aspect, the first fastening elements and the second fastening elements extend in parallel with each other such that the main board and adjustable aperture unit assembly has as small dimensions as possible.

In a further possible implementation form of the third aspect, the first fastening element comprises at least one of rivets, conductive glue, or spring based members.

In a further possible implementation form of the third aspect, the main board is a printed wiring board, preferably extending within a third plane, the third plane being parallel with the first plane and the second plane. This allows for an assembly comprising as few components, and having as small dimensions, as possible.

According to a fourth aspect, there is provided a method of adjusting a size of an aperture area of an aperture unit, the aperture unit comprising a single-piece actuator and a plurality of movable elements configured to delimit the aperture area. The method comprises the step of activating a first part of the single-piece actuator such that a first deformation of the single piece actuator is generated, the first deformation displacing one of the movable elements from a first position to a second position. The aperture area has a first size and/or a first shape when the movable element is in the first position, and the aperture area has a second size and/or second shape when the movable element is in the second position.

This method comprises using a minimum of components, making it cost efficient to produce and reliable in use. Furthermore, the adjustment of the aperture area is flexible due to the flexible movement of the movable element. In a possible implementation form of the fourth aspect, the method further comprises the steps of activating a second part of the single-piece actuator such that a second deformation of the single-piece actuator is generated, the second deformation displacing a further one of the movable elements from a first position to a second position, and, optionally, activating further parts of the single-piece actuator such that further deformation of the single-piece actuator is generated, the further deformation displacing at least one further movable element from a first position to a second position. This allows for maximum flexibility as regards the size and shape of the aperture area, since several moveable elements may be actuated.

In a further possible implementation form of the fourth aspect, the method further comprises the step of deactivating the single-piece actuator, the deactivation generating a return of the single-piece actuator to a non-deformed shape, the return generating movement of at least one of the movable elements from the second position to the first position, such that there is no need for separate return control or return inducing components.

In a further possible implementation form of the fourth aspect, the method further comprises the step of changing the activation of the single-piece actuator such that a change in deformation of the single-piece actuator is generated, allowing the single-piece actuator to generate step-wise displacement of the movable elements.

In a further possible implementation form of the fourth aspect, the activation comprises supplying a first current to at least one actuating arm of the single-piece actuator, the deactivation comprises not supplying the first current to the actuating arm, and the change in activation comprises supplying a second current to the actuating arm, the second current having a different strength than the first current.

These and other aspects will be apparent from the embodiments described below.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following detailed portion of the present disclosure, the aspects, embodiments and implementations will be explained in more detail with reference to the example embodiments shown in the drawings, in which: Fig. 1 shows perspective views of an assembly comprising an adjustable aperture unit and a main board according to an embodiment of the present invention, when assembled;

Fig. 2 shows a top view of a plate element of an adjustable aperture unit according to an embodiment of the present invention;

Fig. 3 shows a perspective view of an adjustable aperture unit and a main board according to an embodiment of the present invention when assembled, and an exploded view of the very same adjustable aperture unit and main board;

Fig. 4 shows an exploded view of the adjustable aperture unit and the main board according to an embodiment of the present invention;

Fig. 5 shows a partial perspective view of the adjustable aperture unit according to an embodiment of the present invention;

Fig. 6 shows atop view of a single-piece actuator and a main board according to an embodiment of the present invention;

Fig. 7 shows a top view of a single-piece actuator according to an embodiment of the present invention;

Figs. 8a to 8d show top views of a single-piece actuator according to an embodiment of the present invention, in a non-deformed state, in two partly deformed states, and in a fully deformed state;

Fig. 9 show top views of a plate element of an adjustable aperture unit according to an embodiment of the present invention, wherein the wings of the plate element are in a first end position, in two intermediate positions, and in a second end position;

Fig. 10 shows a top view of a plate element of an adjustable aperture unit according to an embodiment of the present invention, wherein only one of the wings of the plate element is in the second end position; Fig. 11 shows schematic front and side views of an electronic device comprising an aperture unit according to prior art;

Fig. 12 shows schematic front and side views of an electronic device according to the present invention.

DETAILED DESCRIPTION

Fig. 11 shows an electronic device according to prior art, a so called periscope camera. The device comprises movable plastic lenses which are usually cut in the horizontal direction in order to be able to fit within the device, without affecting the inner aperture shape of the device. The device also comprises a conventional aperture unit with a circular outline. Such a relatively large and fully circular aperture unit increases the form factor of the device as shown in Fig. 11, wherein the aperture unit protrudes in the vertical direction past the perimeter of optical system of the camera.

Fig. 12 shows one embodiment of an electronic device 11 according to the present invention. The device 11 comprises an aperture unit 5 which has a polygonal outline, preferably rectangular, and which has substantially the same height as the device lens group. This allows the aperture unit 5 to be moved linearly, e.g. along with the lens group, inside the device 11 by means of a single-piece actuator 1. The aperture unit 5 will be described in more detail further below.

The electronic device 11 furthermore comprises a main board 12, preferably a printed wiring board, comprising a structure for current supply. The aperture unit 5 is connected to the main board 12 by means of a plurality of first fastening elements 13. The first fastening element 13 may comprise rivets, conductive glue, and/or spring based members. In one embodiment, the first fastening elements 13 are electrically conductive such that they transmit current from the main board 12 to the aperture unit 5, allowing the aperture unit 5 to be electrically operated.

The adjustable aperture unit 5, shown in detail in Figs. 3 and 4, comprises a single-piece actuator 1, which will be described in more detail further below, and a plate element 6. The plate element 6 comprises a peripheral frame 7 which circumscribes a plurality of wings 8. The wings 8 extend in a first plane PI and are configured to delimit the aperture area which is formed at the center of the plate element 6. At least one of the wings 8 are configured to move from a first position to a second position in the first plane PI, in response to the actuation of the single-piece actuator 1, which generates a change in size of the aperture area. The main board 12, mentioned above, may comprise not only electromechanical connection points for the single-piece actuator 1 and plate element 6, but also an outgoing interface section such as an FPC tail.

Stepwise wing movement and change in aperture area is shown in Fig. 9. The leftmost illustration shows the aperture unit in a non-actuated state, with a maximum size aperture area. The rightmost illustration shows the aperture unit in a fully actuated state, wherein each wing 8 has been moved around a center of rotation C, each center of rotation being schematically illustrated in Fig. 2, and in the first plane PI, such that they overlap to a largest degree, hence minimizing the aperture area. The size of the aperture area depends on how much the wings pivot, and hence overlap. The two center illustrations show the intermediate and stepwise wing movement, increase in wing overlap, and decrease in aperture area.

Each wing 8 may comprise a section 8a configured to not collide with an adjacent wing 8 when overlapping, as shown in Figs 9 and 10. The section 8a may be stepped or tilted (not shown) with respect to the remainder of the wing 8, such that the section 8a does not extend in the first plane PI.

As illustrated in Figs. 1 to 4, 9, and 10, one edge of each wing may be curved such that they together give the aperture area an annular outline, which is maintained regardless of the size of the aperture area. The main board 12 may comprise a corresponding annular aperture area, as shown in Figs. 1 and 3 to 6. Other aperture area shapes are nevertheless possible.

One embodiment of the single-piece actuator 1 is shown in Fig. 7. The single-piece actuator 1 is configured to displace a plurality of movable elements 8, such as the above mentioned wings 8. The single-piece actuator 1 may have any suitable shape, however, the main extent of the single-piece actuator is preferably in the second plane P2, giving it a flat, sheet-like configuration. The Figs show an embodiment wherein the single-piece actuator 1 forms a closed loop extending in the second plane P2, however the loop may be open and substantially have a C-shape. Furthermore, the single-piece actuator 1 may be not at all loop shaped but e.g. linear, such as I-shaped. The single-piece actuator 1 may furthermore comprise several, connected or independent, sub-parts, all extending within the second plane P2 (not shown). The movable elements/wings 8 may be displaced in the first plane PI, the single-piece actuator 1 extend within the second plane P2, and the second plane P2 be parallel with the first plane PI as shown in Figs. 3 and 4.

The single-piece actuator 1 may be configured to actuate the plurality of movable elements/wings 8 simultaneously, sequentially, and/or independently. Figs. 8a to 8d and 9 show simultaneous actuation of the single-piece actuator 1 and aperture unit 5, respectively, while Fig. 10 shows actuation of only one movable element/wing 8.

The single-piece actuator 1 comprises a plurality of fastening areas 2 configured to be fastened, to a stationary element, by means of at least one first fastening element 13, enabling the fastening areas 2 to remain stationary during actuation. As mentioned above, the first fastening element 13 may comprise rivets, conductive glue, and/or spring based members, and the fastening areas 2 are preferably directly connected to the main board 12 by means of the first fastening elements first . The fastening areas 2 may comprise annular sections configured to receive the first fastening elements/rivets 13.

By supplying equal voltage, to one pair of oppositely arranged first fastening elements 13, symmetrical displacement of the movable elements/wings 8 may be generated by causing the corner points, i.e. displacement areas 3, of the single-piece actuator 1, to move towards the center of the aperture unit 5. The other pair of oppositely arranged first fastening elements 13 at this instance function as ground elements.

The single-piece actuator 1 furthermore comprises a plurality of displacement areas 3 configured to move during actuation with regards to the fastening areas 2. Each displacement area 3 is configured to be mechanically interconnected with one of the movable elements/wings 8, for example by means of second fastening elements 10. As shown in Fig. 4, the second fastening elements 10 may comprise protrusions, extending from the movable elements/wings 8 in a direction perpendicular to the first plane PI. Correspondingly, the displacement areas 3 may comprise recesses, e.g. annular sections, configured to receive the second fastening elements/protrusions 10 such that movement of a displacement area 3 of the single-piece actuator generates corresponding movement of the corresponding second fastening element 10 and, subsequently, corresponding movement of the corresponding movable element/wing 8, within the first plane PI . In one embodiment, the second fastening elements 10 and the first fastening elements 13 extend in parallel with each other.

The single-piece actuator 1 furthermore comprises a plurality of actuating arms 4, each actuating arm 4 extending from one fastening area 2 to one displacement area 3 as shown in Figs. 7 and 8a to 8d. Each actuating arm 4 is configured to deform in response to electric and/or magnetic activation by means of the one fastening area 2. The deformation of the actuating arm 4 may generate deformation of a circumference of the single-piece actuator 1. In response to the deformation, the one displacement area 3 is moved.

Each displacement area 3 may be located between two fastening areas 2, two actuating arms 4 extending from the displacement area 3 in different directions such that each actuating arm 4 extends towards one of the two fastening areas 2.

The single-piece actuator 1 may comprise a shape memory material, the shape memory material having a one-way shape memory effect or a two-way shape memory effect. The actuating arm 4 may be configured to return to an at least partly non-deformed shape, i.e. have a one-way shape memory effect, and/or deform further, i.e. have a two-way shape memory effect, in response to a change in the electric or magnetic activation. The shape memory material may be a shape memory alloy. The two-way effect may be achieved by a material responding differently at two different temperatures, the different temperatures being generated by the actuation having different strengths.

The electric activation may comprise supplying current to the actuating arm 4 by means of the fastening area 2, in which case the actuating arm 4 returns to an initial, non-deformed shape when the electric deactivation comprises no longer supplying any current to the fastening area 2. A change in electric activation comprises changing the strength of the current, such as increasing or reducing the strength of the current. Such a change does not lead to the actuating arm 4 returning to an initial, non-deformed shape, but changes the shape of the actuating arm 4 to a second deformed shape.

The actuating arm 4 may comprise a plurality of linear segments, each segment extending at an angle relative adjacent linear segments, allowing deformation of the actuating arm 4 within the second plane P2. The linear segments may change in dimensions, or in angular placement relative each other.

As mentioned above, the adjustable aperture unit 5 comprises the single-piece actuator 1 and a plate element 6 comprising a peripheral frame 7 and a plurality of wings 8 extending in the first plane PI. As shown in Figs. 3 and 4, the plate element 6 may be superimposed onto the single piece actuator 1 such that the first plane PI of the plate element 6 extends in parallel with the second plane P2 of the single-piece actuator 1.

As shown in Fig. 2, each wing 8 is connected to the peripheral frame 7 by means of a resilient connection arm 9. The resilient connection arm 9 allows the wing 8 to move around the center of rotation C. The resilient connection arm 9 may be configured such that it returns to the first position, from the second position, by means of the resilience of the resilient connection arm 9. The resilient connection arm 9 may also be connected to a return inducing element such as a spring (not shown), forcing the resilient connection arm 9 back to the first position.

As indicated above, the single-piece actuator 1 is connected to the plate element 6 by means of a plurality of second fastening elements 10, each second fastening element 10 being connected to one wing 8 of the plate element. The second fastening elements 10 may be electrically non- conductive, and the plate element 6 may comprise a sheet material, preferably stainless steel. As also mentioned above, the peripheral frame 7 may comprise a polygonal outline. The outline is sufficiently stable such that it remains unaffected by the actuation of the single-piece actuator 1

The aperture unit 5 may comprise an additional single-piece actuator 1, the single-piece actuators 1 extending in parallel. Preferably, the single-piece actuators 1 are stacked on top of each other, the one single-piece actuator 1 generating first movement of the movable elements/wings 8 in a first direction, and the other single-piece actuator 1 generating second movement of the movable elements/wings 8 in a second direction and/or to a different extent than the first movement.

As mentioned above, the electronic device 11 comprises the adjustable aperture unit 5 and a main board 12 comprising a structure for current supply. The single-piece actuator 1 of the adjustable aperture unit 5 is connected to the main board 12 by means of the first fastening elements 13, as shown in Fig. 5. As shown in Fig 6, each first fastening element 13 is arranged between two second fastening elements 10. The single-piece actuator 1 is arranged between the main board 12 and the plate element 6 of the adjustable aperture unit 5. Fig 1. shows such an assembly. The first fastening elements 13 are electrically conductive, and transmit current from the main board 12 to the fastening areas 2 of the single-piece actuator 1, such that the fastening areas 2 are electrically activated. Preferably, the main board 12 extends within a third plane P3, the third plane P3 being parallel with the first plane PI and the second plane P2.

The present invention also relates to a method of adjusting the size of the aperture area of the aperture unit 5, the method comprising at least the step of activating a first part of the single piece actuator 1 such that a first deformation of the single-piece actuator 1 is generated, the first deformation displacing one of the movable elements/wings 8 from a first position to a second position. This is shown in Fig. 10. The aperture area has a first size and/or a first shape when the movable element/wing 8 is in the first position, and the aperture area has a second size and/or second shape when the movable element/wing is in the second position.

The method may comprise additional steps. A second part of the single-piece actuator 1 may be activated such that a second deformation of the single-piece actuator 1 is generated, the second deformation displacing a further one of the movable element/wing 8 from a first position to a second position. Further parts of the single-piece actuator 1 may also be activated such that further deformation of the single-piece actuator 1 is generated, the further deformation displacing at least one further movable element/wing 8 from a first position to a second position. This is shown in Fig. 9 , which shows movement of all four movable elements/wings 8. The second position may be an identical position for all movable elements/wings 8, but they may also be different for each movable element/wing 8.

The method may also comprise subsequently deactivating the single-piece actuator 1. The deactivation generates a return of the single-piece actuator 1 to an at least partial non-deformed shape, and the return generates movement of at least one of the movable elements/wings 8 from the second position to the first position.

Correspondingly, the method may also comprise changing the activation of the single-piece actuator 1, e.g. by changing the strength of current supplied, such that a change in deformation, rather than a return to a non-deformed shape, of the single-piece actuator 1 is generated. In other words, if the activation comprises supplying a first current to at least one actuating arm 4 of the single-piece actuator 1, the deactivation may comprise not supplying the first current to the actuating arm 4. Similarly, the change in activation may comprise supplying a second current to the actuating arm 4, the second current having a different strength than the first current.

The various aspects and implementations have been described in conjunction with various embodiments herein. However, other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed subject-matter, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word “comprising” does not exclude other elements or steps, and the indefinite article “a” or “an” does not exclude a plurality. A single processor or other unit may fulfill the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measured cannot be used to advantage. A computer program may be stored/distributed on a suitable medium, such as an optical storage medium or a solid-state medium supplied together with or as part of other hardware, but may also be distributed in other forms, such as via the Internet or other wired or wireless telecommunication systems.

The reference signs used in the claims shall not be construed as limiting the scope. Unless otherwise indicated, the drawings are intended to be read (e.g., cross-hatching, arrangement of parts, proportion, degree, etc.) together with the specification, and are to be considered a portion of the entire written description of this disclosure. As used in the description, the terms “horizontal”, “vertical”, “left”, “right”, “up” and “down”, as well as adjectival and adverbial derivatives thereof (e.g., “horizontally”, “rightwardly”, “upwardly”, etc.), simply refer to the orientation of the illustrated structure as the particular drawing figure faces the reader. Similarly, the terms “inwardly” and “outwardly” generally refer to the orientation of a surface relative to its axis of elongation, or axis of rotation, as appropriate.

Claims

1. A single-piece actuator (1) for displacing a plurality of movable elements (8), said single-piece actuator (1) comprising

-a plurality of fastening areas (2) configured to be fastened by means of at least one first fastening element (13), wherein such fastening enables the fastening areas (2) to remain stationary during actuation,

-a plurality of displacement areas (3) configured to move during actuation, with regards to said fastening areas (2), each displacement area (3) being configured to be mechanically interconnected with one of said movable elements (8), and

-a plurality of actuating arms (4), each actuating arm (4) extending from one fastening area (2) to one displacement area, each actuating arm (4) being configured to deform in response to electric and/or magnetic activation by means of said one fastening area (2), wherein said one displacement area (3) being moved in response to said deformation.

2. The single-piece actuator (1) according to claim 1, wherein said actuating arm (4) is configured to return to an at least partly non-deformed shape and/or deform further in response to a change in said electric or magnetic activation.

3. The single-piece actuator (1) according to claim 1 or 2, wherein said electric activation comprises supplying current to said actuating arm (4) by means of said fastening area (2).

4. The single-piece actuator (1) according to any one of the previous claims, wherein said movable elements (8) are displaced in a first plane (PI), and said single-piece actuator (1) extends within a second plane (P2), said second plane (P2) being parallel with said first plane (PI).

5. The single-piece actuator (1) according to any one of the previous claims, wherein said single-piece actuator (1) is configured to actuate said plurality of movable elements (8) simultaneously, sequentially, and/or independently.

6. The single-piece actuator (1) according to any one of the previous claims, wherein said single-piece actuator (1) comprises a shape memory material, said shape memory material having a one-way shape memory effect or a two-way shape memory effect.

7. The single-piece actuator (1) according to any one of the previous claims, wherein said actuating arm (4) comprises a plurality of linear segments, each segment extending at an angle against adjacent linear segments, allowing deformation of said actuating arm (4) within said second plane (P2).

8. An adjustable aperture unit (5) comprising

-the single-piece actuator (1) according to any one of claims 1 to 8, and -a plate element (6) comprising a peripheral frame (7) circumscribing a plurality of wings (8) extending in the first plane (PI), said wings (8) being configured to delimit an aperture area formed at a center of said plate element, at least one of said plurality of wings (8) being configured to move from a first position to a second position in said first plane (PI) in response to the actuation of said single-piece actuator (1), thereby generating a change in size of said aperture area.

9. The aperture unit (5) according to claim 8, wherein each wing (8) is connected to said peripheral frame (7) by means of a resilient connection arm (9), each wing (8) being movable around a center of rotation (C), in said first plane (PI), by means of said resilient connection arm (9).

10. The aperture unit (5) according to claim 9, wherein said resilient connection arm (9) returns to said first position, from said first position, by means of the resilience of said resilient connection arm (9).

11. The aperture unit (5) according to any one of claims 8 to 10, wherein said single-piece actuator (1) is connected to said plate element (6) by means of a plurality of second fastening elements (10), each second fastening element (10) being connected to one wing (8) of said plate element.

12. The aperture unit (5) according to any one of claims 8 to 11, wherein said wings (8) are configured to partially overlap in response to said change in size of said aperture area, each wing (8) comprising a section (8a) configured to not collide with an adjacent wing (8) when overlapping.

13. The aperture unit (5) according to any one of claims 8 to 12, wherein said peripheral frame (7) comprises a polygonal outline, preferably rectangular, said outline being unaffected by said actuation of said single-piece actuator (1).

14. The aperture unit (5) according to any one of claims 8 to 13, further comprising an additional single-piece actuator (1), said single-piece actuators (1) extending in parallel.

15. An electronic device (11) comprising the adjustable aperture unit (5) according to any one of claims 9 to 14 and a main board (12) comprising a structure for current supply, the single-piece actuator (1) of said adjustable aperture unit (5) being connected to said main board (12) by means of the plurality of first fastening elements (13), each first fastening element (13) being located between two second fastening elements (10), said single-piece actuator (1) being arranged between said main board (12) and the plate element (6) of said adjustable aperture unit (5).

16. The electronic device (11) according to claim 15, wherein said first fastening elements (13) are electrically conductive, said first fastening elements (13) being configured to transmit current from said main board (12) to the fastening areas (2) of said single-piece actuator (1), such that said fastening areas (2) are electrically activated.

17. The electronic device (11) according to claim 15 and 16, wherein said first fastening elements (13) and said second fastening elements (10) extend in parallel with each other.

18. A method of adjusting a size of an aperture area of an aperture unit (5), said aperture unit (5) comprising a single-piece actuator (1) and a plurality of movable elements (8) configured to delimit said aperture area, said method comprising the step of:

-activating a first part of said single-piece actuator (1) such that a first deformation of said single-piece actuator (1) is generated, said first deformation displacing one of said movable elements (8) from a first position to a second position, said aperture area having a first size and/or a first shape when said movable element (8) is in said first position, and said aperture area having a second size and/or second shape when said movable element (8) is in said second position.

19. The method according to claim 18, further comprising the steps of:

-activating a second part of said single-piece actuator (1) such that a second deformation of said single-piece actuator (1) is generated, said second deformation displacing a further one of said movable elements (8) from a first position to a second position, and, optionally, -activating further parts of said single-piece actuator (1) such that further deformation of said single-piece actuator (1) is generated, said further deformation displacing at least one further movable element (8) from a first position to a second position.

20. The method according to claim 18 or 19, further comprising the step of:

-deactivating said single-piece actuator (1), said deactivation generating a return of said single piece actuator (1) to a non-deformed shape, said return generating movement of at least one of said movable elements (8) from said second position to said first position.

21. The method according to any one of claims 18 to 20, further comprising the step of: -changing said activation of said single-piece actuator (1) such that a change in deformation of said single-piece actuator (1) is generated.

22. The method according to any one of claims 18 to 21, wherein said activation comprises supplying a first current to at least one actuating arm (4) of said single-piece actuator (1), said deactivation comprises not supplying said first current to said actuating arm (4), and said change in activation comprises supplying a second current to said actuating arm (4), said second current having a different strength than said first current.