WO2018138349A2

WO2018138349A2 - Device for tilting an optical element, particularly a mirror

Info

Publication number: WO2018138349A2
Application number: PCT/EP2018/052155
Authority: WO
Inventors: Stephan SMOLKA; Manuel Aschwanden; David Andreas NIEDERER; Pit Gebbers; Roman Patscheider
Original assignee: Optotune Ag
Priority date: 2017-01-27
Filing date: 2018-01-29
Publication date: 2018-08-02
Also published as: WO2018138349A3

Abstract

The invention relates to a device (1, 2) for pivoting an optical element (10).

Description

Device for tilting an optical element, particularly a mirror Specification

The present invention relates to a device for holding and tilting (or pivoting) an optical element, particularly a mirror, as stated in claim 1.

Particularly, it is an objective of the present invention to provide a fast, precise and compact two-dimensional (2D) scanning mirror.

Particularly, according to a further objective of the present invention it is desirable to provide a relatively large tilt angle in particularly two dimensions and a relatively large mirror diameter with a precise and compact angular control.

Furthermore, particularly, it is also desirable to achieve a very small system footprint and height featuring a mirror that can be tilted particularly in two dimensions (2D) with a precise and compact angular control.

According to claim 1 such a device comprises at least an optical element, wherein the optical element is configured to be tilted about a first axis and/or a second axis.

Further embodiments of the aspects of the present invention are stated in the corresponding sub claims and are described below, particularly in conjunction with the drawings.

The optical element, particularly in form of a mirror, can consist out of one of the following materials: Beryllium, Silicon, Fused Silica/ Quartz, SiC, BK7, Sapphire (AI203), MgF2 and the material can be coated with different materials, particularly gold, protected silver, and/or a dielectric Bragg mirror structure.

Preferably, according to an embodiment, the inner and outer axes are arranged in slide bearing rings (see e.g. below). However, the slide bearing rings may also be omitted. Then, the respective end section of the respective inner or outer axis (see e.g. below) may simply be slidably arranged in the respective hole of a gimbal ring.

Furthermore, for tilting the optical element about the first and/or second axis the device further comprises a gimbal bearing according to an embodiment of the present invention, wherein the gimbal bearing comprises a gimbal ring, a gimbal holder, and a support member, wherein the optical element is connected to the support member.

Further, according to an embodiment of the present invention, the support member is a support plate, particularly a magnetic flux return structure plate, particularly for guiding magnetic flux generated by a magnet that is connected to the support member.

Further, according to an embodiment, the support member is supported on the gimbal ring so that the support member and the optical element can be tilted about the first axis with respect to the gimbal ring. Particularly, the gimbal ring can surround the support member.

Further, according to an embodiment of the device according to the present invention, the first axis is an inner axis which is connected to the support member, wherein particularly the inner axis is connected to the support member by an interference fit, wherein particularly a middle section of the inner axis is arranged in a recess of the support member with an interference fit.

Further, according to an embodiment of the present invention, the inner axis comprises a first end section and an opposing second end section, which end sections are particularly connected to each other via said middle section, and wherein the first end section is slidably arranged in a first slide bearing ring, which first slide bearing ring is arranged in a first hole of the gimbal ring, and wherein the second end section is slidably arranged in a second slide bearing ring, which second slide bearing ring is arranged in a second hole of the gimbal ring.

Furthermore, according to an embodiment of the present invention, the first end section comprises a head having a larger diameter than the remaining portion of the first end section, which head is arranged on an outside of the gimbal ring, wherein particularly a spring is arranged between said head and said first slide bearing ring for reducing mechanical play. Particularly, the spring can be a leaf spring, wherein particularly the leaf spring may extend between neighbouring slide bearing rings.

Furthermore, according to an embodiment of the present invention, the inner axis comprises a sleeve connected to the second end section of the inner axis, wherein particularly said sleeve is connected to the second end section by an interference fit, wherein particularly said sleeve encompasses the second end section, and wherein said sleeve is particularly arranged on an outside of the gimbal ring. Further, according to an embodiment, a spring is arranged between said sleeve and said second slide bearing ring for reducing mechanical play. Particularly the spring can be a leaf spring, wherein particularly the leaf spring may extend between neighbouring slide bearing rings.

Further, according to an embodiment of the present invention, the gimbal ring is supported on the gimbal holder so that the gimbal ring can be tilted about the second axis with respect to the gimbal holder. Particularly, the gimbal holder may surround the gimbal ring.

Furthermore, according to an embodiment of the device according to the present invention, the second axis is formed by a first outer axis and an opposing separate second outer axis, which outer axes are aligned with each other.

Particularly, according to an embodiment, the first outer axis comprises a first end section and an opposing second end section, wherein the first end section of the first outer axis is slidably arranged in a third slide bearing ring, which third slide bearing ring is arranged in a third hole of the gimbal ring, while the second end section of the first outer axis is connected to the gimbal holder, wherein particularly the second end section of the first outer axis is connected to the gimbal holder by an interference fit. According to an embodiment, the second end section of the first outer axis is arranged in a first recess formed in an inner side of the gimbal holder.

Furthermore, according to an embodiment of the present invention, the first outer axis comprises a middle section connecting the first end section of the first outer axis to the second end section of the first outer axis, wherein the middle section of the first outer axis comprises a larger diameter than the first end section of the first outer axis. Particularly, according to an embodiment, the middle section of the first outer axis is arranged on an outside of the gimbal ring, wherein particularly a spring is arranged between the third slide bearing ring and the middle section of the first outer axis for reducing mechanical play. Particularly, the spring can be a leaf spring, wherein particularly the leaf spring may extend between neighbouring slide bearing rings.

Furthermore, according to an embodiment of the present invention, also the second outer axis comprises a first end section and an opposing second end section, wherein the first end section of the second outer axis is slidably arranged in a fourth slide bearing ring, which fourth slide bearing ring is arranged in a fourth hole of the gimbal ring. Furthermore, particularly, the second end section of the second outer axis is connected to the gimbal holder, wherein particularly the second end section of the second outer axis is connected to the gimbal holder by an interference fit. Further, according to an embodiment, the second end section of the second outer axis is arranged in a second recess formed in said inner side of the gimbal holder.

Furthermore, according to an embodiment of the present invention, the second outer axis comprises a middle section connecting the first end section of the second outer axis to the second end section of the second outer axis, wherein the middle section of the second outer axis comprises a larger diameter than the first end section of the second outer axis. Further, in an embodiment, the middle section of the second outer axis is arranged on an outside of the gimbal ring, wherein particularly a spring is arranged between the fourth slide bearing ring and the middle section of the second outer axis for reducing mechanical play. Particularly, the spring can be a leaf spring, wherein particularly the leaf spring may extend between neighbouring slide bearing rings.

Furthermore, according to an embodiment of the present invention, the respective slide bearing ring consists of or comprises one of the following materials: brass, bronze, metal, plastic, Teflon, PEEK, Torlon, LCP, ruby, sapphire, glass, zirconia, alumina, silicon carbide, silicon nitride, chromium.

Furthermore, the inner side of the sliding bearing ring can comprise a cylindrical shape or an olive shape.

Further, according to an embodiment of the present invention, the respective slide bearing ring may also comprise lubrication wells for a lubricant.

Furthermore, according to an embodiment of the present invention, the gimbal ring and the gimbal holder are injection molded parts, wherein the gimbal ring is injection molded onto end sections of the first axis and onto end sections of the second axis (e.g. of the first and second outer axis). Further, particularly, the gimbal holder is injection molded onto end sections of the second axis (e.g. of the first and second outer axis).

Furthermore, according to an embodiment, the support member, which can be ring- shaped, is an injection molded part, too, wherein the support member is injection molded onto end sections of the first axis.

Particularly, the first axis (or inner axis) can be formed by a rod or can comprise a sphere. Further, the first axis may be formed by two separate rods or two separate spheres. Further, particularly the second axis (e.g. said outer axes) can be formed by two separate rods or two separate spheres. It is also possible to combine rods and spheres.

Particularly, according to an embodiment, the support member may be formed by the inner axis that can be formed e.g. by a single rod. Thus, a dedicated separate support member may be omitted and the first axis may also be used as support member to which the optical element (e.g. mirror) is connected.

Further, according to an embodiment of the present invention, the gimbal ring comprises a height in an axial direction of the gimbal ring that is larger than a width of the gimbal ring in a radial direction of the gimbal ring.

Further, according to an embodiment of the present invention, the first axis runs perpendicular to the second axis.

Further, according to an embodiment of the present invention, the optical element is a mirror.

Further, according to an embodiment of the present invention, the device comprises an actuator for tilting the optical element about the first and/or the second axis (e.g. said two outer axes).

Further, according to an embodiment of the present invention, the actuator comprises a magnet connected to the support member, which magnet is axially polarized, i.e. comprises a magnetization that extends along an axial direction which runs perpendicular to the support member, wherein the actuator further comprises a first coil and a second coil, wherein said coils face the magnet in the axial direction, and wherein each coil comprises a conductor that is wound about a coil core such that the conductors cross each other in a region facing the magnet (with respect to the axial direction), wherein in said region the conductor of the first coil extends along the first axis and the conductor of the second coil extends along the second axis. Further, the actuator is configured such that when an electrical current is applied to the first coil, the optical element is tilted about the first axis by a Lorentz force, while in case an electrical current is applied to the second coil, the optical element is tilted about the second axis by a Lorentz force.

Further, according to an alternative embodiment of the present invention, the actuator comprises a plurality of magnets, particularly four magnets, connected to the support member, wherein each magnet comprises a magnetization that extends along an axial direction which runs perpendicular to the support member, wherein the actuator further comprises a corresponding plurality of coils, wherein each magnet protrudes into an opening of an associated coil. Further, according to an embodiment, each magnet has a magnetic flux return structure attached to a face side of the respective magnet, wherein the respective magnetic flux return structure is arranged (or moves with the respective magnet) in the opening of the respective coil. Further, in an embodiment, the actuator is configured such that when an electrical current is applied to the respective coil, the associated magnet is moved further into the opening of the coil or is pushed in the opposite direction depending on the direction of the current in the respective coil.

Further, according to an embodiment of the present invention, the coils are embedded into a printed circuit board (PCB).

Further, according to an embodiment of the present invention, for generating a feedback signal for controlling tilting of the optical element about the first and/or second axis, which feedback signal is indicative of the spatial position of the optical element, the device further comprises four light detectors, particularly photo diodes, and a light source, particularly an LED.

Further, according to an embodiment of the present invention, the light source is configured to emit light so that the light is reflected from a surface that is rigidly connected to the optical element back to the light detectors depending on the spatial position of the optical element.

Further, according to an embodiment of the present invention, the surface is a diffusive reflective surface that comprises a grating, wherein the light source is a laser.

Further, according to an embodiment of the present invention, for generating said feedback signal, the device further comprises a shutter rigidly connected to the optical element (e.g. via the support member), wherein the shutter is configured to shade the light detectors from light emitted by the light source depending on the spatial position of the optical element.

Further, according to an embodiment of the present invention, for generating a feedback signal for controlling tilting of the optical element about the first and/or second axis, which feedback signal is indicative of the spatial position of the optical element, a Hall sensor is arranged in the opening of the respective coil.

Further, according to an embodiment of the present invention, for generating a feedback signal for controlling tilting of the optical element about the first and/or second axis, which feedback signal is indicative of the spatial position of the optical element, a capacitive sensor is arranged in the opening of the respective coil.

Further, according to an embodiment of the present invention, the light detectors and the light source are arranged on a printed circuit board (PCB).

Further, according to an embodiment of the present invention, the device comprises a gimbal support or member, particularly for supporting the gimbal holder and/or for delimiting tilting of the optical element about the first and/or second axis (e.g. in the form of a hard stop).

Further, according to an embodiment of the present invention, the printed circuit board is rigidly connected to said gimbal support, particularly by one of: an interference fit; gluing the printed circuit board to the gimbal support; a spring, wherein said spring is particularly integrally connected to the gimbal support.

Further, according to an embodiment of the present invention, the printed circuit board is arranged between said magnet and said first and second coil, wherein said two coils of the actuator are electrically connected to the printed circuit board by electrically conducting pins. Particularly, each pin engages with a through hole formed in the coil core and a through hole formed in the printed circuit board (PCB). Particularly, in an embodiment, the respective through hole of the coil core is formed in a wing of the core that protrudes out of said first and second coil.

Further, according to an embodiment of the present invention, the device comprises an outer magnetic flux return structure which houses the actuator of the device, wherein the outer magnetic flux return structure comprises an opening in which the gimbal holder is arranged.

Further, according to an embodiment of the present invention, the coil core is arranged with respect to the outer magnetic flux return structure such that magnetic flux can be guided from the coil core to the outer return structure.

Further, according to an embodiment of the present invention, the outer magnetic flux return structure is connected with a latching connection to a base unit of the device.

Further, according to an embodiment of the present invention, the first and the second coil, the coil core, the printed circuit board (PCB), the gimbal support, and the gimbal bearing are supported on the base unit.

According to a further aspect of the present invention, a system is disclosed, wherein the system comprises a device according to the present invention, wherein the optical element is a mirror, and wherein the system further comprises a camera, wherein the mirror of the device is arranged in front of an objective of the camera for selecting a desired field of view.

According to yet another aspect of the present invention, a system is disclosed, wherein the system comprises a device according to the present invention, wherein the optical element is a mirror, and wherein the system further comprises a first camera for overviewing a first field of view corresponding to a full image range, and a second camera, wherein the mirror of the device is arranged in front of an objective of the second camera for selecting a desired field of view inside the full image range. Further, according to an embodiment of the present invention, the system further comprises a beam splitter arranged between the objective of the second camera and the mirror, a light source, and a focus tunable lens, wherein the focus tunable lens is arranged between the light source and the beam splitter such that light emitted by the light source can be directed onto said desired field of view.

According to yet another aspect of the present invention, a system (e.g. for architectural lighting) is disclosed, wherein the system comprises a device according to the present invention, wherein the optical element is a mirror, and wherein the system further comprises a light source for emitting collimated light, wherein the device is configured to reflect said collimated light via said mirror onto at least one reflective or fluorescent surface, which at least one surface is particularly arranged on a building.

Further, according to an embodiment of this system according to the present invention, said at least one surface comprises a retro reflector, and wherein the system further comprises a co-aligned further light source for emitting light that is not harmful to the human or animal eye, particularly a NIR laser, such that light emitted from the further light source is reflected by the retro reflector back to a receiver of the system, wherein the system is adapted to only switch the light source on in case the receiver receives said light from the further light source.

According to yet another aspect of the present invention, a system (e.g. for architectural lighting) is disclosed, wherein the system comprises a device according to the present invention, wherein the optical element is a mirror, and wherein the system further comprises a light source, particularly a NIR laser, for emitting collimated light, wherein the device is configured to reflect said collimated light via said mirror onto at least one active unit, which at least one active unit is particularly arranged on a building, wherein said at least one active unit is configured to be switched on when light of the light source impinges onto the active unit.

According to yet another aspect of the present invention, a use is disclosed, according to which a device according to the present invention is used for at leastone of

- laser-processing,

- (3D) printing,

- vision,

- iris scanner, particularly for scanning of a face to identify the iris, particularly with a high resolution,

- eye-tracking, particularly over several meters of distance,

- LIDAR and large field of view LIDAR, particularly enabled by the large mirror tilt angle and/or the 2D movable axes (e.g. first and/or second axis),

- augmented and/or virtual reality,

- scanning of an area of interest to extend the field of view, such as in a car, around a car, a room, an area or inside of products, e.g. a fridge, traffic, traffic sign recognition, object recognition with high resolution

- machine vision,

- signage,

- laser projection,

- OCT,

- confocal imaging,

- metrology,

- 3D scanners,

- laser-templating,

- ophthalmology equipment,

- lighting, particularly dynamical headlights,

- light show,

- medical equipment,

- time of flight cameras,

- field of view expander,

- motion tracking,

- microscopes,

- endoscopes,

- research, - surveillance camera,

- automotive,

- drivers cab,

- projectors,

- range finder bar code readers,

- wireless charging or powering.

Furthermore, particularly, the magnet or the magnets described herein may be formed out of one of the following materials: Samarium Cobalt SmCo33EN S300, Neodymium-lron-Boron (NdFeB) N50M. These materials are only examples. Other magnets/materials may also be used.

Furthermore, particularly, the magnetic flux return/guiding structures in the various embodiments can be formed out of a metal, particularly a magnetically soft material/metal, Fe-Ni soft magnetic alloys, magnetic guiding stainless steel materials, electric steel, Ferrites and NiZnCu Ferrites.

The printed circuit board (e.g. for carrying coils and/or photo diodes and/or a light source such as an LED) can for instance be formed out of FPC or can be a multilayer PCB such as HDI Anylayer. The printed circuit board can also be any other suitable substrate.

Furthermore, particularly, the conductors for the coils may be made out of copper and may have a thickness in the range from 10 μηη to 200μη"ΐ, particularly 20 μηη to 60μη-ι.

Furthermore, particularly, as light sources, the following LEDs might be used: SFH4441 , VSMB1940X01 , TEMD7100X01 , SFH4043. Of course other light sources might be used.

Furthermore, particularly, as light detectors, the following photo diodes might be used: PD15-22B-TR8-1 , VEMD1 160X01. Of course other light detectors might be used.

Furthermore, particularly, as Hall sensors, the following sensors may be used: AS5013 (2D Hall sensor), AS5510, LC898214XC. Of course, other Hall sensors may also be used.

The materials stated above are to be understood as examples. Other materials may be used as well.

Particular application examples of the present invention are: • Laser-processing

• (3D) printing

• Vision

Iris scanner: scanning of a face to identify the iris in a high resolution Eye-tracking over several meters of distance

LIDAR and large field of view LIDAR enabled by the large mirror tilt angle and/or the 2D movable axes

Augmented and virtual reality

Scanning of an area of interest to extend the field of view, such as in a car, a room, an area or inside of products, e.g. a fridge

Machine vision

• Signage

Laserproject simple pictograms

• Biomedical

- OCT

Confocal imaging

• Metrology

3D scanners

Laser-templating

• Ophthalmology equipment

• Lighting, dynamical headlights

• Laser processing

• Light show

• Printers

• Metrology

• Medical equipment

• Time of flight cameras

• Field of view expander • Motion tracking

• Microscopes

• Endoscopes

• Research · Surveillance camera

• Automotive

• Projectors

• Range finder bar code readers

In the following, features and embodiments of the present invention are described below in conjunction with the Figures. Each individual feature shown in the Figures and/or mentioned in the text may be incorporated (also in an isolated fashion) into a claim relating to the device or any other aspect according to the present invention.

Particularly,

Fig. 1 shows an embodiment of a device according to the present invention using a gimbal bearing particularly based on slide bearings;

Fig. 2 shows an embodiment of the device according to the present invention using a gimbal bearing based on torsion springs;

Fig. 3 shows an exploded view (left hand side) and a perspective (partially cross sectional) view of an embodiment of a gimbal bearing of the device according to the present invention;

Fig. 4 shows a detail of Fig. 3;

Fig. 5 shows a further detail of Fig. 3;

Fig. 6 shows a further detail of Fig. 3;

Fig. 7 shows a perspective view of a gimbal bearing comprising a leaf spring;

Fig. 8 shows a detail of Fig. 7;

Fig. 9 shows a further embodiment of a gimbal bearing wherein the support member, the gimbal ring, and the gimbal holder are formed out of injection molded parts; Fig. 10 shows a further embodiment of a gimbal bearing formed out of injection molded parts;

Fig. 1 1 shows a cross-sectional view of a device according to the present invention comprising a gimbal bearing based on slide bearings;

Fig. 12 shows two coils arranged on a coil core of an actuator of a device according to the present invention, wherein the coils are configured to interact with a magnet of said actuator in order to tilt an optical element of the device;

Fig. 13 shows the coils and the coil core of Fig. 12 connected to a printed circuit board of a device according to the present invention;

Fig. 14 shows an embodiment of a device according to the present invention comprising an outer magnetic flux return structure for housing an actuator of the device, wherein said return structure can be connected to a base unit of the device by means of a latching connection;

Fig. 15 shows a cross sectional view of an embodiment of a device according to the present invention comprising a gimbal bearing based on torsion springs;

Fig. 16 shows a perspective view of an arrangement of magnets and surrounding coils of an actuator of the device shown in Fig. 15;

Fig. 17 shows an alternative arrangement of coils of the actuator of the device shown in Fig. 15, wherein said coils are embedded into a printed circuit board of the device;

Fig. 18 shows a top view onto the gimbal bearing of the device shown in Fig.

15;

Fig. 19 shows an arrangement of light detectors and a light source for determining or controlling a spatial position of the optical element of a device according to the present invention;

Fig. 20 shows a cross sectional view of an embodiment of a device according to the present invention, wherein a printed circuit board of the device is press-fitted or glued to a gimbal support for supporting the gimbal bearing;

Fig. 21 shows a cross sectional view of a further embodiment of a device according to the present invention, wherein a printed circuit board of the device is connected to a gimbal support for supporting the gimbal bearing by means of a latching connection;

Figs. 22 - 23 show a further arrangement of light detectors and a light source for determining or controlling a spatial position of the optical element of a device according to the present invention;

Fig. 24 shows a gimbal support carrying an optical element and a shutter connected to the optical element (left hand side), and a perspective view of said shutter (right hand side);

Figs. 25 - 26 show alternative embodiments of the shutter;

Fig. 27 shows a further arrangement of a light source and light detectors for determining or controlling a spatial position of the optical element;

Fig. 28 shows an arrangement of Hall sensors (left hand side) for determining the spatial position of the optical elements by detecting the magnetic field of magnets connected to the optical element, wherein the magnets form part of an actuator of the device for tilting the optical element, and wherein the right hand side shows a cross section of such a magnet and its associated coil and Hall sensor;

Fig. 29 shows a system according to the present invention comprising a device according to the present invention a well as two cameras;

Fig. 30 shows an embodiment of the system comprising a beam splitter and a focus tunable lens;

Fig. 31 shows yet another system according to the present invention comprising a device according to the present invention;

Fig. 32 shows yet another system according to the present invention comprising a device according to the present invention; and

Fig. 33 shows dimensions of an example of a device according to the present invention, wherein the left hand side shows a lateral view of the device, and the right hand side shows a top view of the device.

Fig. 1 shows an embodiment of a device 1 according to the present invention, wherein the device 1 comprises an optical element 10, particularly a mirror 10 for reflecting incoming light L, wherein the optical element 10 is configured to be tilted about a first axis A1 and/or a second axis A2. For tilting the optical element 10 about the first and/or second axis A1 , A2 the device 1 further comprises a gimbal bearing 2, Particularly, the gimbal bearing 2 enables a precise and fast mirror motion. As shown in Fig. 3, the gimbal bearing 2 can consist out of a rigid gimbal ring 20 with four holes 200 where slide bearing rings 30, 31 , 32, 33 (e.g. ruby discs) with a center hole can be inserted. The first axis A1 and the second axis A2 (A21 , A22) slide inside the slide bearing rings or rubies 30, 31 , 32, 33. The gimbal bearing 2 further comprises an outer bearing holder 21 (also denoted as gimbal holder 21 ) and a holder 22 for the mirror or optical element 10, which holder 22 is also denoted as support member 22.

The slide bearing rings (e.g. rubies) 30, 31 , 32, 33 can be made out of different materials (see also above) e.g. zirconia, alumina, silicon carbide, silicon nitride, and can be monocrystalline or polycrystalline including (among others) chromium.

As further shown in Fig. 3 in conjunction with Figs. 4 to 6, the support member 22 can be formed as a support plate, particularly a magnetic flux return structure plate, for guiding magnetic flux generated by a magnet 60 that is connected to the support member 22.

Further, the support member 22 is supported on the gimbal ring 20 so that the support member 22 and the optical element 10 can be tilted about the first axis A1 with respect to the gimbal ring 20. As indicated in Fig. 3, the gimbal ring 20 can surround the support member 22.

Further, particularly, the first axis A1 is an inner axis A1 which is connected to the support member 22, wherein the inner axis A1 can be connected to the support member 22 by an interference fit. For this, a middle section 44 of the inner axis A1 can arranged in a recess 23 of the support member 22 with an interference fit.

Further, the support member 22 can comprise glue pockets 24 to stress-free glue the mirror 10 to the support member 22 such that the mirror 10 does not deform upon environmental changes.

The inner axis A1 further comprises a first end section 43 and an opposing second end section 45, which end sections 43, 45 are particularly connected to each other via said middle section 44, wherein the first end section 43 is slidably arranged in a first slide bearing ring 30 that is arranged in a first hole 200 of the gimbal ring 20 whereas the second end section 45 is slidably arranged in a second slide bearing ring 31 that is arranged in a second hole 200 of the gimbal ring 20.

As shown particularly in Figs. 3 and 5, the first end section 43 particularly comprises a head 40 having a larger diameter than the remaining portion of the first end section 43, wherein this head 40 is arranged on an outside 20a of the gimbal ring 20. Further, a spring 41 can be arranged between said head 40 and said first slide bearing ring 30 for reducing mechanical play.

By preloading the bearing with a spring 41 the repeatability of the mirror tilt position is improved as the mechanical play is eliminated. Particularly, the bearing can be preloaded single-sided or doubled-sided. A single-sided preloading avoids additional resonances that occur when using a two-sided preloading. The preload can be done using magnets or mechanical springs e.g. plate springs, spiral springs, leaf springs.

Furthermore, using a sleeve 42 on the inner axis A1 , the mechanical play enables a precision adjustment of the bearing 2. The sleeve 42 can be assembled using a glue or a press-fit joint.

As shown in Figs. 7 and 8, particularly at least one leaf spring 41 can be used. In this regard, single-sided preloading can be achieved with a single leaf spring 41 , double- sided preloading with two leaf springs 41 or a single spring spanning around the entire gimbal ring 20.

Particularly, the long lever-arm of the leaf spring 41 enables an approximately constant spring force over the spring travel range. Particularly, the respective spring 41 pushes the gimbal ring 20 away from the axes A1 , A21 , A22.

Material and form of the leaf-spring 41 (thickness, width, cut-extrusions) can be used to control the spring constant.

Furthermore, fixing the leaf spring 41 at the gimbal ring 20 at different positions is a further possibility to adjust the spring constant.

This spring system enables a minimum travel in the sliding bearing. Particularly the spring 41 can be fabricated as a straight piece.

To account for tolerances a round hole 41 a and an elongated hole 41 b (for receiving the inner or first axis A1 and the outer axis, e.g. A22, can be used regarding the spring 41 .

To control the pivot point of the spring 41 (one or two pivot point structures might be pressed or formed into the spring or the spring could be waisted).

As further indicated in Fig. 7, the leaf spring 41 may extend between neighbouring slide bearing rings 30, 33.

The sleeve 42 described above, is particularly connected to the second end section 45 of the inner axis A1 , e.g. by means of an interference fit, wherein particularly said sleeve 42 encompasses the second end section 45. Particularly, the sleeve 42 is arranged on an circumferential outside 20a of the gimbal ring 20, wherein also here a spring 41 as shown in Fig. 5 regarding the head can be arranged between said sleeve 42 and said second slide bearing ring 31 (cf. Fig. 3) for reducing mechanical play. Again also here the spring 41 can be a leaf spring 41 , wherein this leaf spring 41 may extend between neighbouring slide bearing rings 30, 33 in an analogous fashion to the leaf spring 41 shown in Figs. 7 and 8. .

As further indicated in Fig. 3 the gimbal ring 20 is supported on the gimbal holder 21 so that the gimbal ring 20 can be tilted about the second axis A2 (e.g. the two outer axes A21 , A22, see below) with respect to the gimbal holder 21. Particularly, the gimbal holder 21 surrounds the gimbal ring 20.

Furthermore, as indicated in Fig. 3, the second axis A2 can be formed by a first outer axis A21 and an opposing second outer axis A22, which outer axes A21 , A22 are aligned with each other.

Particularly, the first outer axis A21 comprises a first end section 53 and an opposing second end section 55, wherein the first end section 53 of the first outer axis A21 is slidably arranged in a third slide bearing ring 32 that is arranged in a third hole 200 of the gimbal ring 20, and wherein the second end section 55 of the first outer axis A21 is connected to the gimbal holder 21. Particularly, the second end section 55 of the first outer axis A21 is connected to the gimbal holder 21 by an interference fit, wherein particularly the second end section 55 of the first outer axis A21 is arranged in a first recess 201 formed in an inner side 21 b of the gimbal holder 21 .

Furthermore, the first outer axis A21 comprises a middle section 50 connecting the first end section 53 of the first outer axis A21 to the second end section 55 of the first outer axis A21 , wherein the middle section 50 of the first outer axis A21 comprises a larger diameter than the first end section 53 of the first outer axis A21 , wherein particularly the middle section 50 of the first outer axis A21 is arranged on an outside 20a of the gimbal ring 20. Furthermore, a spring 51 can be arranged between the third slide bearing ring 32 and the middle section 50 of the first outer axis A21 for reducing mechanical play. Particularly this spring 51 can be leaf spring, wherein particularly the leaf spring 51 may extend between neighbouring slide bearing rings 31 , 32.

Furthermore, as indicated in Figs. 3, 4 and 6 the second outer axis A22 comprises a first end section 53 and an opposing second end section 55, wherein the first end section 53 of the second outer axis A22 is slidably arranged in a fourth slide bearing ring 33, which fourth slide bearing ring 33 is arranged in a fourth hole 200 of the gimbal ring 20, and wherein the second end section 55 of the second outer axis A22 is connected to the gimbal holder 21 . Further, particularly, the second end section 55 of the second outer axis A22 is connected to the gimbal holder 21 by an interference fit, wherein particularly the second end section 55 of the second outer axis is arranged in a second recess 201 formed in said inner side 21 b of the gimbal holder 21 .

Particularly, also the second outer axis A22 comprises a middle section 50 connecting the first end section 53 of the second outer axis A22 to the second end section 55 of the second outer axis A22, wherein the middle section 50 of the second outer axis A22 comprises a larger diameter than the first end section 53 of the second outer axis A22, wherein particularly the middle section 50 of the second outer axis A22 is arranged on an outside 20a of the gimbal ring 20. Particularly, a spring 51 can be arranged in turn between the fourth slide bearing ring 33 and the middle section 50 of the second outer axis A22 for reducing mechanical play. Particularly, the spring 51 can be a leaf spring, wherein particularly the leaf spring may extend between neighbouring slide bearing rings 30, 33.

As further shown in Fig. 4, the gimbal ring 20 comprises a height A in an axial direction z of the gimbal ring 20 that is larger than a width B of the gimbal ring 20 in a radial direction of the gimbal ring 20.

Particularly, the gimbal ring height A shall be larger than the gimbal width B to increase the lowest lying eigen frequencies of the gimbal. This increases the overall stiffness with respect to bending when tilting the mirror or optical element 10. Less energy is transferred into the resonance when (de)accelerating the mirror 10, thus the mirror tilt speed is enhanced and more efficient.

Further, the slide bearing ring (e.g. rubies) 30, 31 , 32, 33 enable a longer life time of the sliding bearing as compared to a bearing consisting out of metal only. A minimum bearing play in an axial sliding bearing formed by the bearing rings 30, 31 , 32, 33 and the axes A1 , A21 , A22 to improve the accuracy and repeatability of the bearing system as each tilt position is accurately defined. Low ruby/slide bearing ring tolerance is utilized to reduce the radial mechanical play between the axes A1 , A21 , A22 and the slide bearing rings(e.g. rubies) 30, 31 , 32, 33. The tolerances of the axes A1 , A21 , A22 to the bearing rings (e.g. rubies) 30, 31 , 32, 33 can be matched in an iterative process. Further, particularly, slide bearing ring surfaces and axis surfaces are polished and lubricated minimizing friction and enabling a faster optical element or mirror 10, higher position accuracy and longer life-time.

The magnetic flux of the actuator remains unobstructed when using a non-magetic material for the axes A1 , A21 , A22 and gimbal ring 20 facilitating a simpler mirror control. Hence, the dependence between tilt angle and actuator power consumption is less non-linear.

Regarding the embodiment shown in Fig. 3 it is also possible to increase precision through magnetic bias of axial play (magnetic preloading).

In order to counter the effect of mechanical play on precision, the main magnetic circuit can be used in an embodiment to define a preferred state of the bearing play.

This is done by e.g. designing the magnetic circuit so that it has an energy minimum at the preferred bearing position.

E.g., in an embodiment where one of the outer axes A21 , A22 is made of a material with high magnetic permeability μ, and the other outer axis is made of a material with low μ, and both gimbal ring 20 and gimbal holder 21 have high μ, the gimbal ring 20 will always be moved towards the outer axis with high μ, because this reduces the energy stored in the magnetic circuit.

The same applies to the inner axis A1 when the inner axis A1 is magnetic, and the inner axis sleeve 42 is non-magnetic.

This principle can be applied with more efficiency by shaping all components in a way that there is a clear overall field energy minimum at one end of the mechanical play

Figs. 9 and 10 show a further possibility for designing the gimbal bearing 2 that can be used with the device 1 described herein.

According thereto, the components of the gimbal bearing can be formed by plastic injection molding (or ceramic or metal injection molding). Particularly, the plastic shrinks when cooling it down after molding. By inserting spheres and/or rods into the mold, a gap between the spheres or rods A1 , A1 1 , A12, A21 , A21 and the respective plastic part will be created resulting in a mechanical play such that the support member 22 and gimble ring 20 create a freely rotating 2D gimbal structure. The plastic material that can be used for injection molding can be (among others): LCP, Peek, Torlon, PVC, PET. Also a combination of rods and spheres is possible. Spheres and rods A1 , A1 1 , A12, A21 , A21 can consist out of any metal or ceramic material.

Particularly, according to the embodiment of a gimbal bearing 2 shown in Fig. 9, the gimbal ring 20, gimbal holder 21 , and support member 22 (for carrying the optical element 10) are injection molded parts, wherein the gimbal ring 20 is injection molded onto end sections 46 of the first axis A1 formed by two separate spheres A12, A12 and onto end sections 56 of the second axis that is also formed by two separate spheres A21 , A22.

Furthermore, the gimbal holder 21 is injection molded onto end sections 57 of the second axes A21 , A22.

Furthermore, the support member 22 is injection molded onto end sections 47 of the first axes A1 1 , A12.

Due to the shrinkage described above, sufficient play will be generated between the inner axes A1 1 , A12 and the support member 22 and gimbal ring 21 to allow tilting of the support member 22 or optical element (e.g. mirror) 10 with respect to the gimbal ring 20. Further, sufficient play will be generated between the outer axes A21 , A22 and the gimbal ring 20 and the gimbal holder 21 to allow tilting of the gimbal ring 20 with respect to the gimbal holder 21 .

Fig. 10 shows a further variant of an injection molded gimbal bearing 2. Here, the first axis is a rod A1 that also forms the support member for carrying the optical element (e.g. mirror) 10. The gimbal ring 20 is injection molded onto opposing end sections 46 of this first axis A1 as well as on end sections 56 of the outer axes A21 , A22. Furthermore, the gimbal holder 21 is injection molded onto end sections 57 of the outer axes A21 , A22 to produce the gimbal structure 2 shown in Fig. 10.

Fig. 1 1 shows a cross section of the device shown in Fig. 1 having the gimbal bearing as shown in Fig. 3. Particularly, the power consumption of the mirror 10 can be reduced by increasing the outer return structure diameter C.

The fundamental mechanical resonance of the mirror 10 can further be increased by reducing the return structure diameter C enabling a mirror usage with very lower power consumption at or close to this resonance.

The actuator of the device 1 that can be used to tilt the optical element 10 about the first or second axis A1 , A2 can comprises two coils 61 , 62 arranged on a coil core 63 as will be explained in more detail below in conjunction with Figs. 12 and 13. The actuator efficiency can be improved by using a non-magnetic base-unit 210 on which the actuator is supported.

Furthermore, as indicated in Fig. 1 1 the device 1 can comprises a heatsink 220 according to an embodiment (e.g. for receiving heat generated by the coils 61 , 62 when a current is applied to the coils 61 , 62) that can e.g. be arranged below the actuator of the device (e.g. below the coils and coil core). Such a heat sink 220 can be used in all embodiments of the present invention.

Particularly, the heat sink 220 can be a passive or an active heat sink 220 (e.g. the heatsink 220 can comprise a Peltier element). Further, the heat sink 220 may be configured for liquid cooling using e.g. water, oil, or a cooling liquid for cooling. The device 1 or heat sink 220 may also be configured to cool the coils (e.g. 61 , 62) directly, wherein the coils 61 , 62 can be placed inside a hermetically sealed area of the heat sink 220.

Further, as shown in Fig. 1 1 , the device 1 can comprise an outer magnetic flux return structure 100 which houses the actuator, wherein the outer magnetic flux return structure 100 can comprise an opening 101 in which the gimbal holder 21 is arranged.

As indicated in Figs. 12 and 13, the actuator of the device 1 may comprise two coils 61 , 62 that are wound around a coil core 63. The design of the coil core 63 is such that the magnetic field can be guided from the coil core 63 to the outer return structure 100. Particularly, the loose ends of the coils 61 , 62 can be soldered to a printed circuit board 610 (PCB) which results in a mechanical vibration isolation with respect to the PCB 610.

The electrical conduction between the PCB 610 and the actuator can be realized with electrically conducting pins 64. This enables a solder-free and fast assembly where the actuator can be clicked into the PCB 610 and the process stability is improved.

The coils 61 , 62 and the PCB 610 can be combined in a single PCB 610 enabling a further assembly process improvement as well as a higher actuator efficiency. Hereby, the coil wires (or conductors) 65 are replaced by PCB traces or printed circuit paths.

Particularly, as shown in Fig. 1 1 , the printed circuit board 610 is arranged between said magnet 60 and said first and second coil 61 , 62, wherein according to Figs. 12 and 13 said two coils 61 , 62 of the actuator are electrically connected to the printed circuit board 610 by said electrically conducting pins 64, wherein each pin 64 engages with a through hole 600 formed in the coil core 63 and a through hole 601 formed in the printed circuit board 610, wherein particularly the respective through 600 hole of the coil core 63 is formed in a wing 63a of the core 63 that protrudes out of said first and second coil 61 , 62. Particularly, the coil wires (or conductors) 65 can be soldered to the pins 64 for achieving an electrical connection between the pins 64 and the respective coil 61 , 62

As further shown in Fig. 1 1 , the device 1 is configured for generating a feedback signal for controlling tilting of the optical element 10 about the first and/or second axis A1 , A2, which feedback signal is indicative of the spatial position of the optical element 10. For this, the device 1 further comprises four light detectors, particularly photo diodes PD1 , PD2, PD3, PD4, and a light source LS, particularly an LED.

Here, the light source LS is configured to emit light so that the light is reflected from a surface S that is rigidly connected to the optical element 10 (e.g. a surface of the magnet 60) back to the light detectors PD1 , PD2, PD3, PD4 depending on the spatial position of the optical element 10. The actual control of the optical element tilting will be described in more detail further below.

Furthermore, Fig. 14 shows a mechanical stack-up principle based on a click- mechanism, here in form of a latching connection LC, to enable a fast assembly of the device 1 1 shown in Figs. 1 and 1 1 , wherein a tolerance in the stack-up assembly is captured with a mechanical spring, e.g. a damping material, such as a flexible or soft spacer (e.g. O-ring) 213 that is arranged between the outer return structure 100 and the gimbal holder 21 .

Particularly, said latching connection LC comprises at least one mechanical spring 21 1 included in the base unit 210 (e.g. integrally formed with the base unit 210), which spring structure 21 1 is configured to engage with a through hole 212 formed in the outer return structure 100. By means of the latching connection LC, the outer magnetic flux return structure 100 can be connected to the base unit 210 of the device 1.

Further, the coils 61 , 62, the coil core 63, the printed circuit board 610, a gimbal support 90 for supporting the gimbal holder 21 , and the gimbal bearing 20, 21 , 22 are supported on the base unit 210. Fig. 15 shows a cross sectional view of a device 1 according to the present invention as shown in Fig. 2. As the device 1 shown in Fig. 1 , this device 1 also allows 2D tilting of an optical element 10, e.g. a mirror 10, about two axes A1 , A2.

Here, the actuator comprises spatially separated magnet-coil pairs as shown in Fig. 16 or 28

By moving magnets 70 into coils 71 with an opening (also denoted air core) 700, the actuator efficiency is increased and the actuator height is reduced. A magnetic guiding flux return structure (metal plate) arranged on the respective magnet 70 may further enhance the actuator efficiency.

As indicated in Fig. 16 a compact 2D tilting device 1 can be realized with two, three, four or more actuators. The best mirror/optical element tilt performance is achieved when the individual actuators (i.e. magnet-coil-pairs) are placed symmetrically around the x-y center position of the printed circuit board 610 and as much outside as possible resulting in the largest lever arm. Particularly, the PCB 610 of the device can also be an FPC (flexible printed circuit). The tilt direction can be reversed by inverting the applied coil current.

Furthermore, several coils 71 be driven in series. E.g. in case of an even number of coils 71 , the coil pairs 71 opposing each other can be driven in series such that one of the two coils 71 pushes the magnet upwards while the other magnet is pushed downwards.

Particularly, according to an embodiment indicated in Figs. 15 and 16, the actuator comprises a four magnets 70 connected to the support member 22, wherein each magnet 70 comprises a magnetization that extends along an axial direction z which runs perpendicular to the support member 22, wherein the actuator further comprises four coils 71 , wherein each magnet 70 protrudes into an opening 700 of an associated coil 71 , and wherein particularly each magnet 70 has a magnetic flux return structure 72 attached to its face side, wherein the respective magnetic flux return structure 72 is arranged or moves in the opening 700 of the respective coil 71 . In case an electrical current is applied to the respective coil 71 , the associated magnet 70 is moved further into the opening 700 of the respective coil 71 or is pushed in the opposite direction depending on the direction of the current in the respective coil. As further shown in Fig. 17, the respective coil 71 can be embedded inside a single PCB 610 that can either be soldered on a another PCB or flex or feature at least one (or already all further electronic components) such as a connector and feedback readout, which might be realized with light detectors, light sources, position sensitive devices, Hall sensors, capacitive sensors, accelerometric sensors, gyrometric sensors, and further different sensors. Also additional electric elements controlling the mirror can be included in the PCB 610.

Furthermore, printed circuit traces can be arranged within a PCB layer such that they resemble a wired coil structure (e.g. for forming the individual coil 71 ).

Furthermore, the insulation layer thicknesses are minimized to increase the filling factor of the respective coil 71 .

The circuit traces of the respective coil 71 can be extended to several layers inside the PCB 610 and can be interconnected to each other.

Additional copper filling inside the PCB 610 can be used as heat conductors to improve the cooling of the device 1 .

Furthermore, the PCB 610 can have integrated mechanical features such as extrusions, holes, pins, mounting features, or cut extrusions, particularly millings or complete millings.

Furthermore, the PCB 610 can also feature a part of a frame 610a or be the frame 610a itself. In an embodiment, the gimbal bearing 2 (e.g. according to Fig. 18 below) can be mounted to this frame 610a.

Furthermore, as shown in Fig. 18, the device according to Fig. 15 can comprise a gimbal bearing 2 using torsion springs 300, 301 .

Here, the gimbal bearing 2 comprises support member 22 to which the optical element (e.g. mirror) 10 is connected. The support member 22 is connected to the gimbal ring 20 via two first torsion springs 300 which are aligned and form a first axis A1 so that said optical element 10 can be tilted about the first axis A1 with respect to gimbal ring 20. Tilting of the optical element 10 thereby twists the torsion springs 300 and generates a restoring force that tries to tilt the optical element 10 back. Further, the gimbal ring 20 is connected via two second torsion springs 301 that form the second axis A2 to the gimbal holder 21 , so that the gimbal ring 20 can be tilted about the second axis A2 with respect to the gimbal holder 21 that is a frame member. Also here, tilting of the gimbal ring 20 with respect to the gimbal holder 21 twists the second torsion springs 301 and generates a restoring force that tries to tilt the gimbal ring 20 back.

Particularly, as shown in Fig. 18, the torsion springs 300, 301 , gimbal ring 20, gimbal holder 21 , support member 22 can be integrally connected to one another to form a single component.

Particularly, the above described torsion spring structure 2 enables a process stable, fast and cheap bearing assembly. Particularly, the spring structure or gimbal bearing 2 can be made out of a single material such as a sheet material.

Furthermore this design of a gimbal bearing 2 has the advantage that abrasion is suppressed.

Furthermore, lateral play (x y direction) is inhibited.

Furthermore, the movement in z-direction is suppressed by having a torsion spring material thickness in z direction that larger than the material width. Furthermore, the length of the respective torsion spring 300, 301 is much longer than the width and height such that the torsion resulting in a mirror tilt requires low torque and consequently actuation power, while a x-y movement and z-movement of the torsion spring is minimized resulting in a precise and repeatable and fast mirror or optical element movement.

Furthermore, Fig. 19 illustrates an embodiment for controlling the tilting of the optical element 10 that can e.g. be applied to the embodiment shown in Figs. 1 and 1 1.

Here, for generating a feedback signal for controlling said tilting of the optical element 10 about the first and/or second axis A1 , A2, which feedback signal is indicative of the spatial position of the optical element 10, the device 1 further comprises said four light detectors PD1 , PD2, PD3, PD4, and said light source LS, particularly an LED, that have been introduced above.

Particularly, a unique two-dimensional optical feedback signal as a function of tilt angle (right hand side of Fig. 19can be achieved by reflecting light from the light source LS back to the light detectors PD1 , PD2, PD3, PD4 (e.g. photo diodes, position sensitive devices, photo multipliers etc.) via an reflective surface S that features a rigid and defined connection to the mirror surface.

Particularly, the tilt angle along the axis x and axis y can be mapped onto an optical feedback signal

Feedback x = ((PD2+PD3)-(PD1 +PD4))/(PD2+PD3+PD1 +PD4) Feedback y = ((PD1 +PD2)-(PD3+PD4))/(PD2+PD3+PD1 +PD4)

By changing the reflective surface finish, an optical feedback signal inversion can be inhibited. In particular, a diffusive surface, i.e. a Gaussian scatterer with sigma>0.2 can be used to avoid an optical feedback inversion for tilt angles larger than 10 degrees. A diffusive surface S can be achieved with multiple scattering of light that might be realized with microparticles inside a coating (e.g. titaniumdioxide, aluminium oxide, semiconductor nanowires) or a randomly structured surfaces. The optical feedback inversion is defined as a non-monotonic behaviour of the feedback signal over the angular tilt range which can result in problems regarding control of the mirror or optical element 10 when the angular tilt-position is not unambiguously defined.

Further, the optical feedback signal can be linearized and the optical feedback signal inversion can be pushed to larger tilt angles by additionally changing the reflective surface shape, in particular by adding a curvature to the surface S. Particularly, the curvature can be achieved by the surface tension of the reflective material or by shaping of the reflective surface S.

Furthermore, the occurance of an optical feedback inversion can be inhibited by limiting the tilt angle with a hard stop.

Furthermore, the inversion of the optical feedback can be inhibited by applying an absorptive coating for the wavelengths of the light source on all areas where a secondary reflection can illuminate one or more photo diodes, in particular the hard stop, the return structure plate and the side walls of the magnet 60.

Furthermore, the linearity of the optical feedback signal is improved and the optical feedback signal inversion can be inhibited by increasing the distance between the reflective surface S and the light source LS and photo diodes PD1 , PD2, PD3, PD4. Further, the optical feedback signal inversion can be shifted to larger tilt angles and can be further linearized by using a different optical feedback calculation method:

Feedback x' = Feedback x ^* (Feedback y ^* Feedback y + 1 )

Feedback y' = Feedback y ^* (Feedback x ^* Feedback x + 1 ).

Furthermore, Figs. 20 and 21 illustrate a way to further improve mechanical reference between mirror tilt angle and the optical feedback signal.

In order to record a precise optical feedback signal that resembles the mirror tilt angle position, a mechanical stable reference between the light source LS, reflective surface S that is attached to the mirror or optical element 10 and the photodiodes PD1 , PD2, PD3, PD4 is beneficial. Thus, it is desirable that the PCB 610 is in rigid contact with the gimbal bearing structure 2. This can be achieved by glueing or pressing the PCB 610 to a gimbal support 90 (cf. Fig. 20) or by attaching the PCB 610 with a spring 91 to the gimbal support 90. Particularly, a spring 91 integrated into the gimbal support 90 improves the process stability, and increases the assembly process.

Furthermore, Figs. 22 and 23 show a further embodiment for generating a feedback signal for controlling tilting of the optical element 10 about the first and/or second axis A1 , A2, which feedback signal is indicative of the spatial position of the optical element. For this, the device 1 in turn comprises four light detectors, particularly photo diodes PD1 , PD2, PD3, PD4, and a light source LS, particularly an LED. Particularly, the embodiment shown in Figs. 22 and 23 can e.g. be applied to the device shown in Figs. 2 and 15.

Furthermore, for generating said feedback signal, the device 1 further comprises a shutter 80 rigidly connected to the optical element 10, wherein the shutter 80 is configured to shade the light detectors PD1 , PD2, PD3, PD4 from light emitted by the light source LS depending on the spatial position of the optical element 10.

Particularly, four photo diodes PD1 , PD2, PD3, PD4 can be positioned such that the sensitive areas S' of these photo diodes face a light source LS in the center, e.g. side-looking type or top-looking type mounted on the side, contacted on a half via in the PCB/FPC 610.

The light from the light source LS illuminates directly or indirectly the photodiodes PD1 , PD2, PD3, PD4.

By tilting the mirror or optical element 10 the shutter 80 attached to the mirror or optical element 10 shades the four photo diodes PD1 , PD2, PD3, PD4 differently and as a function of both tilt angles in x and y-direction.

From the signal of all photo diodes PD1 , PD2, PD3, PD4 the tilt position of the mirror/optical element 10 can be calculated. In case of a one-dimensionally tilting device 1 only two photo diodes are required.

Furthermore, alternatively, the device 1 con comprise four light sources (instead of the photo diodes) for controlling the tilting of the optical element 10 (e.g. mirror 10), wherein particularly the light sources face the center of the PCB 610 where a single photo diode is positioned, such that by tilting the optical element or mirror 10 a shutter 80 attached to the optical element or mirror 10 shades the light sources illuminating the photo diode. The device is further configure to modulate the light sources (LEDs) in a subsequent pattern so that the tilt position of the optical element or mirror 10 can be calculated from the intensity of the light source (LED) signal on the photodiode or photodiodes.

As indicated in Figs. 24 to 26, the shutter can be made out of different rigid materials and can comprise different shapes. Particularly, the shutter 80 shall block half of the photosensitive area of the photodiodes PD1 , PD2, PD3, PD4 in case of four photodiodes in the corners. Thus, the shutter height A' needs to be adjusted. In case of four light sources (LEDs) in the corners the shutter 80 height shall be such that half of the total light source (LED) light hits the central photodiode in the not-tilted mirror position.

The different shapes of the shutters 80 shown in Figs. 24 to 26 can be realized by stamping, etching, laser cutting, CNC machining, welding, water jetting, injection molding, 3D printing etc.

Particularly, as shown in Fig. 24, the shutter 80 is attached such to the optical element (e.g. mirror) 10, particularly via the support member 22, that it comprises four lateral outer surfaces particularly protrude from the a base 80a of the respective shutter (e.g. Figs. 24 and 26).

Furthermore, according to Fig. 27 it is also possible to apply a grating G on a diffusive reflective surface S connected to the optical element 10 to enable an additional position encoding enabling a higher precision feedback. The grating G can have different shapes, e.g. circles, squares, random unique patterns. The grating pattern G can be constant with position or change its shape over position. Here, light sensors PD measure the reflected intensity peaks created by the grating G versus the position of the optical element 10. Preferably, the light source LS is coherent to achieve constructive and destructive interference.

Fig. 28 illustrates a further feedback mechanism. Here, a feedback is used that does not rely on an optical signal and is thus inherent insensitive to light changes in the environment.

In contrast to using light signals, Hall sensors 81 are placed inside the coils opening 700 (see also above) in order to measure how deep the respective magnet 70 extends into the respective coil opening 700. A similar result can be achieved by using capacitive feedback sensors. Mapping between feedback sensor signals (Fx, Fy) and angular tilt of the optical element or mirror 10 can be achieved by measuring the tilt position of the optical element 10 or mirror 10 in x and y direction with an external measurement device and correlating these data to the feedback signals at this position.

The data can be interpolated to find for each tilt angle the feedback signal.

A two-dimensional function such as a polynomial function can be fitted separately for each feedback signal: Fx(x,y) & Fy(x,y).

The calibration data can be written into an EEPROM (e.g. of the device 1 ) and the calibration can be adjusted with temperature by measuring the temperature on the PCB 610 with a temperature sensor and first calibrating at two controlled temperatures.

Fig. 29 illustrates an application example of the device 1 according to the present invention. Here the device 1 forms a component of a system 3 wherein the mirror 10 of the device is arranged in front of a camera C2 to select a field of view FOV along different spatial directions by tilting the mirror 10 accordingly.

This method can be used for FOV expansion, tracking, FOV stitching, zoom-in of a image section, surveillance systems, etc.

Regarding zoom-in of image section, the system 3 particularly comprises a first camera C1 having a wide angle lens WL overviewing the full image range FOV1 , and a second camera C2, comprising a narrow angle zoom lens ZL where the 2D mirror 10 in front of the objective 02 of camera C2 selects the desired field of view (FOV2) position.

This system 3 can be used to increase the level of detail with camera C2 in a desired subarea FOV2 selected from the full FOV recorded with camera C1.

Such a zoom-in of an image section can e.g. be used in the following fields:

Automotive (driver assistance):

Here, the wide angle field of view of camera C1 oversees the full angular range and may use object detection (e.g. people, signs, faces, text, cars, obstacles). By tilting the mirror 10 accordingly, camera C2 can record the images within the region of interest where the object was detected

Surveillance Systems: Within an area that needs to be supervised, moving objects can be tracked. A moving object is identified on camera C1 and the region of interest is chosen accordingly. The tilt angle of the 2D mirror 10 is set such that the area of the moving objects can be recorded with camera C2.

Face recognition:

On the wide angle camera C1 faces can be detected and this region of interest can be selected with the high resolution camera C2 to identify the face or the iris.

Camera systems under low light conditions:

Under low light conditions the pixel size of a camera has to be increased to ensure a sufficient image quality. Due to this fact the number of pixels needs to be reduced. Using the zoom-in of image detection camera C2 can achieve a high image resolution with a lower image noise within a region of interest that can be chosen from camera C1. The pixelsize of camera C1 does not depend on the pixel size of camera C2.

Further, by using an IR camera, persons or objects that radiate heat can be detected and followed.

Bar code reading:

Choosing a sub-area that is selected from the image of camera C1 where e.g. a bar code is detected. Thus, high resolution image of a bar code or another text can be obtained.

Furthermore, Inserting a tunable lens between camera C2 and the 2D mirror 10 enables focussing on different image planes within the region of interest.

Furthermore, Fig. 30 shows yet another application example of a device 1 according to the present invention regarding zoom-in of an image section and illumination of a designated area. Here, the system 3 in question comprises camera C1 observes a larger field of view FOV1 , and a coaligned light source LS that is placed in between the mirror 10 of the device 1 and the camera C2 with a beam splitter BS (or instead of the camera C2, i.e. beam splitter can be omitted) can be used to illuminate a region of interest FOV2. A tunable lens TL behind the light source LS can be used to change the area of illumination by focussing or defocussing the light beam. When using a polarized light source LS, the beam splitter BS can be replaced with a polarizing beam splitter to direct the reflected light to the 2D mirror device 1 without loosing 50% of the light which is transmitted in case of a non-polarizing beam splitter BS.

Figure Fig. 31 relates to yet another application of the device 1 according to the present invention to a system 4 for architectural lighting using a passive target surface

Here, the 2D mirror 10 of the device 1 directs a collimated light source LS of one or more colors, e.g. a laser, LED or other bright light source onto a surface S1 that is either fluorescent or reflective, such as e.g. ceramic.

The surfaces S1 may be attached at buildings, screens, light signs or other target surfaces in the public and private domain.

The surface S1 may be shaped such that the reflected or emitted light is directed to the desired visual field by diffusing the light and the brightness can be maximized eventually exceeding the brightness of an active light source on the target.

By optimizing the visual field and using a diffusive reflector and a string laser light source the brightness can be increased.

One or several surfaces S1 may be illuminated at once by the mirror 10 depending on the beam size of the light source LS and the size of the reflective surface S1.

When the illumination time is shorter than the accumulation time of the eye, several surfaces S1 can be illuminated at different positions within the accumulation time and an image or pictogram may be created.

Several lightening units (device 1 and light system) may be combined to increase the visual appearance and the brightness of the architectural lightening system.

In this aspect of the present invention no cables need to be installed on the target surface S1 (building etc.) reducing installation costs.

There are no active electric elements that need to be maintained on the target surface reducing the costs per unit.

The required space on the target surface is minimized.

The lighting unit may be encapsulated into a room of constant ambient temperature and encapsulated from humidity and dust such that its life time can be increased as compared to active electronic lighting elements in the environment on the target surface. Furthermore, in an embodiment the passive light surface features a retro reflector R1 (e.g. cat eye). A second co-aligned (e.g. eye-safe) NIR laser LS' can be send corresponding NIR laser light L" to the passive lighting unit S1 , R1 . The NIR laser LS' is reflected by the retro reflector R1 back to the lighting unit. When NIR light is recorded in the lighting unit, the collimated light source LS is switched on.

Finally, Fig. 32 shows a further application of a device 1 according to the present invention relating to a system 5 for architectural lighting. Here, instead of a passive target (cf. Fig. 31 ) an active target surface A1 is involved. Particularly, the active unit A1 may comprise a receiver, controller and one or more light sources

The active unit A1 can be switched on (to generate light L') with a laser LS that generates light L that is incident onto a receiver (with help of the mirror 10 of the device 1 ) which is part of the active unit A1 , e.g. a photovoltaic cell, a photomultiplier, a avalanche photo diode. The recorded electrical current pulse activates a light source that is part of the active unit A1.

The wavelength or the laser is preferably matched to the sensitivity of the receiver cell, e.g. 900nm for Si photo cells, or e.g. 1300nm for InGe photo cells.

The light source may be switched off after a certain delay time.

The light source may be switch off with a second laser pulse (bistable system).

According to an embodiment, different light sources within one active unit A1 may be activated by changing the incident laser power, pulse pattern, or laser wavelength onto the receiver.

By moving over a large pattern of many active units A1 forming e.g. a screen, an image or video with a high resolution can be created.

The resolution is not limited to the resolution of a movie as an interpolation with additional lightening units in between the pixels of the movie can be achieved (oversampling).

This aspect of the present invention can utilize a collimated eye safe near infrared laser LS for generating light L that is invisible for the eye.

Further, in this aspect of the present invention, the installation of control lines and connection to a controller unit can be avoided.

Furthermore, the implementation of individual independent subsystems can decrease maintenance costs. Finally, Fig. 33 shows an example of a device 1 according to the present invention, particularly individual dimensions that can be achieved within the framework of the present invention.

Here, the actuator allows to tilt the optical element 10 about two axes A1 , A2 (see also above).

The mechanical tilt angle (DC & dynamic) of the optical element 10 corresponds to ±25° (X axis) and ±25° (Y axis).

The diameter of the mirror 10 amounts to 15 mm.

The center of rotation to mirror surface amounts to 1 .3 mm

The external diameter amounts to 30 mm.

The height amounts to 18.7 mm.

The weight of the device 1 amounts to 32 g.

The repeatability RMS (typical) is 0.3 mrad.

The full scale bandwidth is 20 Hz.

The small signal bandwidth is 350 Hz.

The large angle step response (20° step) amounts to 7.5 ms.

The small angle step response (0.1 ° step) amounts to 1 .4 ms.

The mirror flatness (P-V) corresponds to λ/2.

The actuation current is smaller than 0.5 A steady state, 1 A peak.

The max actuation power is smaller than 1 W.

Claims

1 . Device (1 ) for tilting an optical element, comprising:

- An optical element (10), wherein the optical element (10) can be tilted about a first axis (A1 ) and/or a second axis (A2).

2. Device according to claim 1 , characterized in that for tilting the optical element (10) about the first and/or second axis (A1 , A2) the device (1 ) further comprises a gimbal bearing (2), wherein the gimbal bearing (2) comprises a gimbal ring (20), a gimbal holder (21 ), and a support member (22), wherein the optical element (10) is connected to the support member (22).

3. Device according to claim 2, characterized in that the support member (22) is a support plate, particularly a magnetic flux return structure plate, particularly for guiding magnetic flux generated by a magnet (60) that is connected to the support member (22).

4. Device according to claim 2 or 3, characterized in that the support member (22) is supported on the gimbal ring (20) so that the support member (22) and the optical element (10) can be tilted about the first axis (A1 ) with respect to the gimbal ring (20).

5. Device according to one of the claims 2 to 4, characterized in that the gimbal ring (20) surrounds the support member (22).

6. Device according to one of the claims 2 to 5, characterized in that the first axis (A1 ) is an inner axis (A1 ) which is connected to the support member (22), wherein particularly the inner axis (A1 ) is connected to the support member (22) by an interference fit, wherein particularly a middle section (44) of the inner axis (A1 ) is arranged in a recess (23) of the support member (22) with an interference fit.

7. Device according to claim 6, characterized in that the inner axis (A1 ) comprises a first end section (43) and an opposing second end section (45), which end sections (43, 45) are particularly connected to each other via said middle section (44), and wherein the first end section (43) is slidably arranged in a first slide bearing ring (30), which first slide bearing ring (30) is arranged in a first hole

(200) of the gimbal ring (20), and wherein the second end section (45) is slidably arranged in a second slide bearing ring (31 ), which second slide bearing ring (31 ) is arranged in a second hole (200) of the gimbal ring (20).

8. Device according to claim 7, characterized in that the first end section (43) comprises a head (40) having a larger diameter than the remaining portion of the first end section (43), which head (40) is arranged on an outside (20a) of the gimbal ring (20), wherein particularly a spring (41 ) is arranged between said head (40) and said first slide bearing ring (30) for reducing mechanical play, wherein particularly the spring (41 ) is a leaf spring, wherein particularly the leaf spring may extend between neighbouring slide bearing rings.

9. Device according to claim 7 or 8, characterized in that the inner axis (A1 ) comprises a sleeve (42) connected to the second end section (45) of the inner axis (A1 ), wherein particularly said sleeve (42) is connected to the second end section (45) by an interference fit, wherein particularly said sleeve (42) encompasses the second end section (45), and wherein said sleeve (42) is arranged on an outside (20a) of the gimbal ring (20), wherein particularly a spring (41 ) is arranged between said sleeve (42) and said second slide bearing ring (31 ) for reducing mechanical play, wherein particularly the spring (41 ) is a leaf spring, wherein particularly the leaf spring may extend between neighbouring slide bearing rings (30, 33).

10. Device according to one of the claims 2 to 9, characterized in that the gimbal ring (20) is supported on the gimbal holder (21 ) so that the gimbal ring (20) can be tilted about the second axis (A2) with respect to the gimbal holder (21 ).

1 1 . Device according to one of the claims 2 to 10, characterized in that the gimbal holder (21 ) surrounds the gimbal ring (20).

12. Device according to one of the claims 2 to 1 1 , characterized in that the second axis (A2) is formed by a first outer axis (A21 ) and an opposing second outer axis (A22), which outer axes (A21 , A22) are aligned with each other.

13. Device according to claim 12, characterized in that the first outer axis (A21 ) comprises a first end section (53) and an opposing second end section (55), wherein the first end section (53) of the first outer axis (A21 ) is slidably arranged in a third slide bearing ring (32), which third slide bearing ring (32) is arranged in a third hole (200) of the gimbal ring (20), and wherein the second end section (55) of the first outer axis (A21 ) is connected to the gimbal holder (21 ), wherein particularly the second end section (55) of the first outer axis (A21 ) is connected to the gimbal holder (21 ) by an interference fit, wherein particularly the second end section (55) of the first outer axis (A21 ) is arranged in a first recess (201 ) formed in an inner side (21 b) of the gimbal holder (21 ).

14. Device according to claim 13, characterized in that the first outer axis (A21 ) comprises a middle section (50) connecting the first end section (53) of the first outer axis (A21 ) to the second end section (55) of the first outer axis (A21 ), wherein the middle section (50) of the first outer axis (A21 ) comprises a larger diameter than the first end section (53) of the first outer axis (A21 ), wherein particularly the middle section (50) of the first outer axis (A21 ) is arranged on an outside (20a) of the gimbal ring (20), and wherein particularly a spring (51 ) is arranged between the third slide bearing ring (32) and the middle section (50) of the first outer axis (A21 ) for reducing mechanical play, wherein particularly the spring (51 ) is a leaf spring, wherein particularly the leaf spring may extend between neighbouring slide bearing rings (31 , 32).

15. Device according to one of the claims 12 to 14, characterized in that the second outer axis (A22) comprises a first end section (53) and an opposing second end section (55), wherein the first end section (53) of the second outer axis (A22) is slidably arranged in a fourth slide bearing ring (33), which fourth slide bearing ring (33) is arranged in a fourth hole (200) of the gimbal ring (20), and wherein the second end section (55) of the second outer axis (A22) is connected to the gimbal holder (21 ), wherein particularly the second end section (55) of the second outer axis (A22) is connected to the gimbal holder (21 ) by an interference fit, wherein particularly the second end section (55) of the second outer axis is arranged in a second recess (201 ) formed in said inner side (21 b) of the gimbal holder (21 ).

16. Device according to claim 15, characterized in that the second outer axis (A22) comprises a middle section (50) connecting the first end section (53) of the second outer axis (A22) to the second end section (55) of the second outer axis (A22), wherein the middle section (50) of the second outer axis (A22) comprises a larger diameter than the first end section (53) of the second outer axis (A22), wherein particularly the middle section (50) of the second outer axis (A22) is arranged on an outside (20a) of the gimbal ring (20), and wherein particularly a spring (51 ) is arranged between the fourth slide bearing ring (33) and the middle section (50) of the second outer axis (A22) for reducing mechanical play, wherein particularly the spring (51 ) is a leaf spring, wherein particularly the leaf spring may extend between neighbouring slide bearing rings (30, 33).

17. Device according to one of the claims 7 to 9, 13 to 16, characterized in that the respective slide bearing ring (30, 31 , 32, 33) consists of or comprises one of the following materials: brass, bronze, metal, plastic, Teflon, PEEK, Torlon, LCP, ruby, sapphire, glass, zirconia, alumina, silicon carbide, silicon nitride, chromium. 18. Device according to one of the claims 7 to 9, 13 to 17, characterized in that the respective slide bearing ring (30, 31 , 32, 33) comprises a cylindrical shape.

19. Device according to one of the claims 7 to 9, 13 to 18, characterized in that the respective slide bearing ring (30, 31 , 32, 33) comprises lubrication wells for the lubricant.

20. Device according to one of the claims 2 to 19, characterized in that gimbal ring (20) and gimbal holder (21 ) are injection molded parts, wherein the gimbal ring (20) is injection molded onto end sections (46) of the first axis (A1 ; A12, A12) and onto end sections (56) of the second axis (A21 , A22), and wherein the gimbal holder (21 ) is injection molded onto end sections (57) of the second axis (A21 , A22).

21 . Device according to claim 20, characterized in that the support member (22) is an injection molded part, wherein the support member (22) is injection molded onto end sections (47) of the first axis (A1 1 , A12).

22. Device according to claim 20 or 21 , characterized in that the first axis (A1 ) is formed by a rod (A1 ), or that the first axis (A1 ) is formed by two separate rods or by two separate spheres (A1 1 , A12).

23. Device according to one of the claims 20 to 22, characterized in that the second axis (A21 , A22) is formed by two separate rods or by two separate spheres.

24. Device according to one of the claims 2 to 23, characterized in that the gimbal ring (20) comprises a height (A) in an axial direction of the gimbal ring (20) that is larger than a width (B) of the gimbal ring (20) in a radial direction of the gimbal ring (20).

25. Device according to one of the preceding claims, characterized in that the first axis (A1 ) runs perpendicular to the second axis (A2).

26. Device according to one of the preceding claims, characterized in that the optical element (10) is a mirror.

27. Device according to one of the preceding claims, characterized in that the device (1 ) comprises an actuator for tilting the optical element (10) about the first and/or second axis (A1 , A2).

28. Device according to claims 2 and 27, characterized in that the actuator comprises a magnet (60) connected to the support member (22), which magnet (60) comprises a magnetization that extends along an axial direction (z) which runs perpendicular to the support member (22), wherein the actuator further comprises a first coil (61 ) and a second coil (62), wherein said coils (61 , 62) face the magnet (60) in the axial direction (z), and wherein each coil (61 , 62) comprises a conductor that is wound about a coil core (63) such that the conductors cross each other in a region (612) facing the magnet (60) in the axial direction (z), wherein in said region (612) the conductor of the first coil (61 ) extends along the first axis (A1 ) and the conductor of the second coil (62) extends along the second axis (A2), and wherein when an electrical current is applied to the first coil (61 ), the optical element (10) is tilted about the first axis (A1 ) by a Lorentz force, and wherein when an electrical current is applied to the second coil (62), the optical element (10) is tilted about the second axis (A2) by a Lorentz force.

29. Device according to claims 2 and 27, characterized in that the actuator comprises a plurality of magnets (70), particularly four magnets, connected to the support member (22), wherein each magnet (70) comprises a magnetization that extends along an axial direction (z) which runs perpendicular to the support member (22), wherein the actuator further comprises a corresponding plurality of coils (71 ), wherein each magnet (70) protrudes into an opening (700) of an associated coil (71 ), wherein particularly each magnet (70) has a magnetic flux return structure (72) attached to its face side, wherein the respective magnetic flux return structure (72) is arranged in the opening (700) of the respective coil (71 ), and wherein when an electrical current is applied to the respective coil (71 ), the associated magnet (70) is moved further into the opening (700) of the respective coil (71 ) or is pushed in the opposite direction depending on the direction of the current in the respective coil (71 ).

30. Device according to claim 29, characterized in that the coils (71 ) are embedded into a printed circuit board (610).

31 . Device according to one of the preceding claims, characterized in that for generating a feedback signal for controlling tilting of the optical element (10) about the first and/or second axis (A1 , A2), which feedback signal is indicative of the spatial position of the optical element, the device (1 ) further comprises four light detectors, particularly photo diodes (PD1 , PD2, PD3, PD4), and a light source (LS), particularly an LED.

32. Device according to claim 31 , characterized in that the light source (LS) is configured to emit light (L) so that the light (L) is reflected from a surface (S) that is rigidly connected to the optical element (10) back to the light detectors (PD1 , PD2, PD3, PD4) depending on the spatial position of the optical element (10).

33. Device according to claim 32, characterized in that the surface (S) is a diffusive reflective surface that comprises a grating, wherein the light source (LS) is a laser.

34. Device according to claim 31 , characterized in that for generating said feedback signal the device (1 ) further comprises a shutter (80) rigidly connected to the optical element (10), wherein the shutter (80) is configured to shade the light detectors (PD1 , PD2, PD3, PD4) from light emitted by the light source (LS) depending on the spatial position of the optical element (10).

35. Device according to claim 29 or 30, characterized in that for generating a feedback signal for controlling tilting of the optical element (10) about the first and/or second axis (A1 , A2), which feedback signal is indicative of the spatial position of the optical element (10), a Hall sensor (81 ) is arranged in the opening (700) of the respective coil (71 ).

36. Device according to claim 29 or 30, characterized in that for generating a feedback signal for controlling tilting of the optical element (10) about the first and/or second axis (A1 , A2), which feedback signal is indicative of the spatial position of the optical element (10), a capacitive sensor is arranged in the opening (700) of the respective coil (71 ).

37. Device according to one of the claims 31 to 34, characterized in that the light detectors (PD1 , PD2, PD3, PD4) and the light source (LS) are arranged on a printed circuit board (610).

38. Device according to one of the preceding claims, characterized in that the device comprises a gimbal support (90), particularly for supporting the gimbal holder (21 ) and/or for delimiting tilting of the optical element (10) about the first and/or second axis (A1 , A2).

39. Device according to claim 38, characterized in that the printed circuit board (610) is rigidly connected to said gimbal support (90), particularly by one of: an interference fit; gluing the printed circuit board (610) to the gimbal support (90); a spring (91 ), wherein said spring (91 ) is particularly integrally connected to the gimbal support (90).

40. Device according to claim 28 and according to one of the claims 37 to 39, characterized in that the printed circuit board (610) is arranged between said magnet (60) and said first and second coil (61 , 62), wherein said two coils (61 , 62) of the actuator are electrically connected to the printed circuit board (610) by electrically conducting pins (64), wherein each pin (64) engages with a through hole (600) formed in the coil core (63) and a through hole (601 ) formed in the printed circuit board (610), wherein particularly the respective through hole (601 ) of the coil core is formed in a wing (63a) of the core that protrudes out of said first and second coil (61 , 62).

41 . Device according to one of the claims 27 to 40, characterized in that the device (1 ) comprises an outer magnetic flux return structure (100) which houses the actuator, wherein the outer magnetic flux return structure (100) comprises an opening (101 ) in which the gimbal holder (21 ) is arranged.

42. Device according to claims 28 and 41 , characterized in that the coil core (63) is arranged with respect to the outer magnetic flux return structure (100) such that magnetic flux can be guided from the coil core (63) to the outer magnetic flux return structure (100).

43. Device according to claim 41 or 42, characterized in that the outer magnetic flux return structure (100) is connected with a latching connection (LC) to a base unit (210) of the device (1 ).

44. Device according to claims 2, 28, 37, 38, and 43, characterized in that the first and the second coil (61 , 62), the coil core (63), the printed circuit board (610), the gimbal support (90), and the gimbal bearing (20, 21 , 22) are supported on the base unit (210).

45. System comprising a device (1 ) according to one of the preceding claims, wherein the optical element (10) is a mirror, and wherein the system (3) further comprises a camera, wherein the mirror of the device is arranged in front of an objective of the camera for selecting a desired field of view.

46. System (3) comprising a device according to one of the claims 1 to 44, wherein the optical element is a mirror, and wherein the system further comprises a first camera (C1 ) for overviewing a first field of view (FOV1 ) corresponding to a full image range, and a second camera (C2), wherein the mirror (10) of the device (1 ) is arranged in front of an objective (02) of the second camera (C2) for selecting a desired field of view (FOV2) inside the full image range.

47. System according to claim 46, characterized in that the system (3) further comprises a beam splitter (BS) arranged between the objective (02) of the second camera (C2) and the mirror (10), a light source (LS), and a focus tunable lens (TL), wherein the focus tunable lens (TL) is arranged between the light source (LS) and the beam splitter (BS) such that light (L) emitted by the light source (LS) can be directed onto said desired field of view (FOV2).

48. System (4), particularly for architectural lighting, comprising a device (1 ) according to one of the claims 1 to 44, wherein the optical element (10) is a mirror, and wherein the system (4) further comprises a light source (LS) for emitting collimated light (L), wherein the device (1 ) is configured to reflect said collimated light (L) via said mirror (10) onto at least one reflective or fluorescent surface (S1 ), which at least one surface (S1 ) is particularly arranged on a building.

49. System according to claim 48, characterized in that said at least one surface (S1 ) comprises a retro reflector (R1 ), and wherein the system (4) further comprises a co-aligned further light source (LS') for emitting light (L") that is not harmful to the human or animal eye, particularly a NIR laser, such that light (L") emitted from the further light source (LS') is reflected by the retro reflector (R1 ) back to a receiver (R2) of the system (4), wherein the system (4) is adapted to only switch the light source (LS) on in case the receiver (R2) receives said light (L") from the further light source (LS').

50. System (5), particularly for architectural lighting, comprising a device according to one of the claims 1 to 44, wherein the optical element (10) is a mirror, and wherein the system (5) further comprises a light source (LS), particularly a NIR laser, for emitting collimated light (L), wherein the device (1 ) is configured to reflect said collimated light (L) via said mirror (10) onto at least one active unit (A1 ), which at least one active unit (A1 ) is particularly arranged on a building, wherein said at least one active unit (A1 ) is configured to be switched on when light (L) of the light source (L) impinges onto the active unit (A1 ). Use of a device according to one of the claims 1 to 44 for at least one of: