Patent Description:
Microelectromechanical System, MEMS, mirrors are miniature electromagnetic mirrors, which may be used for example in projectors, displays, imaging and fiber-optic communications. Advantages of MEMS mirrors comprise low power consumption, wide deflection angles and high reflectivity. MEMS mirrors may have dead spots and complex mechanics though. In addition, MEMS mirrors may be expensive as well. Thus, there is a need to provide improvements for MEMS mirrors.

<CIT> discloses a projection image display apparatus with a MEMS mirror and a lens used therefor.

<NPL>" discloses a compact omnidirectional scanning system based on an omnidirectional lens and a biaxial large aperture tripod MEMS mirror.

<CIT> discloses a galvanometer panoramic scanning device for a laser radar. <CIT> discloses an omnidirectional illumination device with a laser light source, a movable mirror for reflecting the laser beam coming from the laser light source, and deflection optics for deflecting the laser beam coming from the mirror into the solid angle range to be scanned. <CIT> discloses an optical base station including a base, a light source, a rotation plate and an optical fiber. The rotation plate drives the optical fiber to rotate around a rotation axis.

<CIT> discloses a device with a laser source; a deflection device; and an optical device which is arranged and designed such that the provided laser beam between the laser source and the deflection device interacts with at least a first region of the optical device, and which is also arranged and designed such that the deflected laser beam interacts with at least a second region of the optical device.

The subject-matter of the claimed invention is defined in the independent claim. Some embodiments are defined in the dependent claims.

According to a first aspect of the present invention, there is provided a Microelectrical System, MEMS, mirror apparatus, comprising a lens with a circular top surface, the circular top surface being provided with a recess having an inclined surface extending from the circular top surface and a side wall having an inclined section extending from the circular top surface, wherein the inclined section is inclined towards the recess and the inclined surface is inclined outward of the recess towards the inclined section. Some embodiments of the first aspect may further comprise at least one feature from the following bulleted list:.

According to the present invention, the MEMS mirror apparatus further comprises a MEMS mirror and a laser source, wherein the MEMS mirror and the laser source are on a same side of the lens. The MEMS mirror and the laser source are below the lens. The MEMS mirror apparatus may further comprise one platform for electric connection, wherein the MEMS mirror and the laser source may be connected to said one platform. In some embodiments, said one platform for electric connection may be a printed circuit board.

Embodiments of the present invention relate to a lens for a Microelectromechanical System System, MEMS, mirror and enable assembling of all components of the MEMS mirror to a same side of the lens, such as below the lens. Thus, simplified mechanics and lower costs may be provided. Also, dead spots may be avoided as well, because there is no need for a support structure that would be needed if all the components of the MEMS mirror would not be on the same side of the lens.

More specifically, embodiments of the present invention enable assembling of all components of the MEMS mirror to the same side of the lens by providing a lens comprising a side wall having an inclined section extending from a circular top surface of the lens. The circular top surface may comprise a recess having an inclined surface extending from the circular top surface as well. More specifically, the inclined section of the side wall may be inclined towards the recess of the circular top surface. In addition, the inclined surface may be inclined outward of the recess towards the inclined section.

In the claimed invention, the inclined section of the side wall is configured so that a laser beam coming from one side of the lens, that is, below the lens, is reflected from the inclined section to the recess of the circular top surface while the recess is configured to reflect the laser beam further to said one side of the lens, towards the MEMS mirror for example.

In some embodiments of the present invention, a MEMS mirror may be used to refer to a Micro-Opto-Electromechanical System, MOEMS, mirror. A MOEMS mirror may be a mirror that is used in optical applications. That is to say, a MEMS mirror may be a general term which is not limited to any specific application, and a MEMS mirror covers for example a MOEMS mirror as well.

<FIG> illustrates operation of a MEMS mirror in accordance with at least some embodiments of the present invention. In <FIG>, MEMS mirror apparatus is denoted by <NUM>. MEMS mirror, or a surface of MEMS mirror more specifically, is denoted by <NUM>. At least one outgoing beam is denoted by <NUM>, normal is denoted by <NUM>, circular scan is shown by arrow <NUM> and deflection angle is denoted by <NUM>.

In some embodiments of the present invention, MEMS mirror <NUM> may be tilted and a laser beam may be directed using MEMS mirror <NUM> to provide at least one outgoing beam <NUM>. Thus, circular scan <NUM> may be provided by rotating at least one outgoing beam <NUM> around normal <NUM>. MEMS mirror <NUM> may be tilted by deflection angle <NUM> as well.

Normal <NUM> may refer to a vertical direction. The expression "vertical" may mean a direction which is identical with the normal to the surface of the Earth and the expression "horizontal" may mean a direction which is perpendicular to the normal to the surface of the Earth. In some embodiments, normal <NUM> may be related to MEMS mirror apparatus <NUM>. For instance, the expression "vertical" may mean a direction which is identical with normal <NUM> of MEMS mirror apparatus <NUM> and "horizontal" may mean a direction which is perpendicular to normal <NUM> of MEMS mirror apparatus <NUM>.

<FIG> and <FIG> illustrate examples of lenses for MEMS mirror apparatus <NUM>. Even though <FIG> and <FIG> show a cross-sectional view, MEMS mirror apparatus <NUM> and lenses may be three-dimensional.

<FIG> illustrates a first example in accordance with at least some embodiments of the present invention. In the example of <FIG>, lens <NUM> of MEMS mirror apparatus <NUM> comprises circular top surface <NUM> and side wall <NUM>. Side wall <NUM> may further comprise cylindrical side wall section <NUM> and conical side wall section <NUM>. Conical side wall section <NUM> may extend at downward angle <NUM> from circular top surface <NUM> to cylindrical side wall section <NUM>, i.e., at a downward angle from a plane of circular top surface <NUM>. Conical side wall section <NUM> may have, i.e., comprise, inclined surface <NUM>. In general, conical side wall section <NUM> may be referred to as an inclined section of side wall <NUM> as well.

Downward angle <NUM> of conical side wall section <NUM> may be for example <NUM> degrees with respect to a line that is perpendicular to a plane of circular top surface <NUM>. Circular top surface <NUM> may further comprise conical recess <NUM>. Conical recess <NUM> may have, i.e. comprise, inclined surface <NUM> extending from circular top surface <NUM>. Conical recess <NUM>, i.e., inclined surface <NUM> of conical recess <NUM> may extend from a plane of circular top surface <NUM> at downward angle <NUM>. Conical side wall section <NUM> and conical recess <NUM> may be opposite to each other. In some embodiments, circular top surface <NUM>, i.e., a plane of circular top surface, may be horizontal.

Conical side wall section <NUM> may extend from circular top surface <NUM> and be inclined towards conical recess <NUM>. Moreover, inclined surface <NUM> of conical side wall section <NUM> may be inclined outward of conical recess <NUM> towards conical side wall section <NUM>. That is to say, an upper end of inclined surface <NUM> of conical side wall section <NUM> and an upper end of inclined surface <NUM> of conical recess <NUM> may be closer to each other than a lower end of inclined surface <NUM> of conical side wall section <NUM> and a lower end of inclined surface <NUM> of conical recess <NUM>.

In some embodiments, lens <NUM> may comprise bottom surface <NUM>. Bottom surface <NUM> may further comprise cylindrical bottom surface section <NUM> and circular bottom surface section <NUM>. Conical recess <NUM> and inclined surface <NUM> may extend from a plane of circular top surface <NUM> at downward angle <NUM> towards bottom surface <NUM>, e.g., towards circular bottom surface section <NUM>. Conical side wall section <NUM> may also extend at downward angle <NUM> from a plane of circular top surface <NUM> to a plane of bottom surface <NUM>.

In some embodiments, a distance between conical side wall section <NUM> of side wall <NUM> and conical recess <NUM> of circular top surface <NUM> may correspond to a distance between cylindrical bottom surface section <NUM> and circular bottom surface section <NUM>. For instance, a midpoint of conical side wall section <NUM> of side wall <NUM> may be vertically at a same position as a midpoint of cylindrical bottom surface section <NUM> and a midpoint of conical recess <NUM> of circular top surface <NUM> may be vertically at a same position as a midpoint of a circular bottom surface section <NUM>.

In addition to lens <NUM>, MEMS mirror apparatus <NUM> may comprise MEMS mirror <NUM>, such as MEMS mirror <NUM> in <FIG>, and laser source <NUM>. In some embodiments, MEMS mirror <NUM> and laser source <NUM> may be on the same side of lens <NUM>. For instance, MEMS mirror <NUM> and laser source <NUM> may be below lens <NUM>. That is to say, MEMS mirror <NUM> and laser source <NUM> may be positioned so that bottom surface <NUM> of lens <NUM> is the nearest component of lens <NUM> to both, MEMS mirror <NUM> and laser source <NUM>. In some embodiments, MEMS mirror apparatus <NUM> may further comprise detector <NUM>.

In some embodiments, MEMS mirror apparatus <NUM> may comprise at least one platform for electric connection <NUM>. MEMS mirror apparatus <NUM> may comprise for example two platforms <NUM> for electric connection (not shown in <FIG>). In such a case, MEMS mirror <NUM> and laser source <NUM> may be coupled to different platforms <NUM>, for example to make it possible to have separate components, wherein a first component comprises MEMS mirror <NUM> connected to a first platform and a second component comprises laser source <NUM> connected to a second platform. Thus, if for example MEMS mirror <NUM> is broken, it is not necessary to replace laser source <NUM>, but only the first component may be changed. Additional costs may be therefore avoided, if MEMS mirror <NUM> or laser source <NUM> needs to be replaced.

Alternatively, in some embodiments, MEMS mirror apparatus <NUM> may comprise one platform for electric connection <NUM> and MEMS mirror <NUM> and laser source <NUM> may be connected to said one platform <NUM>. That is to say, MEMS mirror <NUM> and laser source <NUM> may be connected to the same platform <NUM> to reduce the costs by avoiding the use of multiple platforms <NUM>. The at least one platform for electric connection <NUM> may be for example a Printed Circuit Board, PCB.

Laser source <NUM> may be configured to emit a laser beam towards cylindrical bottom surface section <NUM>. For example, the laser beam may be emitted by laser source <NUM> towards conical side wall section <NUM> of side wall <NUM> via cylindrical bottom surface section <NUM>. In some embodiments, conical side wall section <NUM>, i.e., inclined surface <NUM> of conical side wall section <NUM>, may be configured to reflect the laser beam, the laser beam coming from one side of lens <NUM>, towards conical recess <NUM> of circular top surface <NUM>. For instance, conical side wall section <NUM>, i.e., inclined surface <NUM> of conical side wall section <NUM>, may be configured to reflect the laser beam substantially horizontally towards conical recess <NUM> of circular top surface <NUM>, i.e., inclined surface <NUM> of conical recess <NUM> of circular top surface <NUM>. In some embodiments of the present invention, inclined surface <NUM> of conical side wall section <NUM> and inclined surface <NUM> conical recess <NUM> may refer to surfaces that are within lens <NUM>.

Downward angle <NUM> of conical side wall section <NUM> may be, e.g., <NUM> degrees, or about <NUM> degrees. Downward angle <NUM> of conical side wall section <NUM> may refer to an angle that has a vertex on circular top surface <NUM> and downward angle <NUM> of conical side wall section <NUM> may be formed between a line that is perpendicular to circular top surface <NUM> and inclined surface <NUM> of conical side wall section <NUM>.

Conical recess <NUM>, i.e., inclined surface <NUM> of conical recess <NUM>, may be configured to reflect the laser beam coming from conical side wall section <NUM> towards circular bottom surface section <NUM> of bottom surface <NUM>. That is to say, for example inclined surface <NUM> of conical recess <NUM> may be configured to reflect the laser beam further towards MEMS mirror <NUM>, possibly via circular bottom surface section <NUM> of bottom surface <NUM>, to said one side of lens <NUM>.

Conical recess <NUM>, i.e., inclined surface <NUM> of conical recess <NUM> of circular top surface <NUM> may extend at a downward angle <NUM> from a plane of circular top surface <NUM>. That is to say, conical recess <NUM> and inclined surface <NUM> of conical recess <NUM> may extend from circular top surface <NUM> towards bottom surface <NUM>. Downward angle <NUM> of conical recess <NUM> and inclined surface <NUM> of conical recess <NUM> may be, e.g., <NUM> degrees, or about <NUM> degrees, as well. Downward angle <NUM> of conical recess and inclined surface <NUM> of conical recess <NUM> may refer to an angle that has a vertex on circular top surface <NUM> and downward angle <NUM> may be formed between a line that is in-line with circular top surface <NUM> and inclined surface <NUM> of conical recess <NUM>.

Conical side wall section <NUM> of side wall <NUM> and conical recess <NUM> of circular top surface <NUM> may be at the same level, for instance if downward angle <NUM> of conical recess <NUM> is <NUM> degrees and downward angle <NUM> of conical side wall section <NUM> is <NUM> degrees as well. That is to say, conical side wall section <NUM> of side wall <NUM> and conical recess <NUM> of circular top surface <NUM> may be at the same level horizontally. Thus, inclined surface <NUM> of conical side wall section <NUM> and inclined surface <NUM> of conical recess <NUM> may be at the same level horizontally as well.

In some embodiments, downward angle <NUM> of conical recess <NUM> of circular top surface <NUM> may be the same, or about the same, as downward angle <NUM> of conical side wall section <NUM> of side wall <NUM>. That is to say, if for example downward angle <NUM> of conical side wall section <NUM> is <NUM> degrees, conical recess <NUM> may be positioned above conical side wall section <NUM> at downward angle <NUM> of <NUM> degrees, to direct the laser beam vertically to MEMS mirror <NUM>.

In some embodiments, MEMS mirror <NUM> may be tilted to direct the laser beam coming from conical recess <NUM> towards another conical recess <NUM>. In some embodiments, circular top surface <NUM> may comprise only one other conical recess <NUM>. For instance, circular top surface <NUM> may comprise only one other conical recess <NUM> if conical sidewall section <NUM> and conical recess <NUM> have been cut to lens <NUM> only on one side of lens <NUM>. In such a case, MEMS mirror <NUM> may be tilted only towards said one other conical recess <NUM>. On the other hand, if lens <NUM> comprises two other conical recesses <NUM>, i.e., conical sidewall section <NUM> and another conical recess <NUM> have been cut to lens <NUM> on both sides of lens <NUM> as shown in <FIG>, MEMS mirror <NUM> may be tilted towards both conical recesses <NUM>.

In some embodiments, conical side wall section <NUM>, conical recess <NUM> and/or one or two conical recesses <NUM> may be symmetric with respect to circular lens <NUM>. Alternatively, conical side wall section <NUM>, conical recess <NUM> and/or one or two conical recesses <NUM> may not be symmetric with respect to circular lens <NUM>. In such a case, conical side wall section <NUM> may be only at a location of laser source <NUM> and conical recess <NUM> and one or two conical recesses <NUM> may be at a location that corresponds to a location of conical side wall section <NUM>.

In any case, at least one other recess <NUM> of circular top surface <NUM> may be configured to reflect the laser beam coming from MEMS mirror <NUM>, via circular bottom surface section <NUM>, towards cylindrical side wall section <NUM>. For instance, at least one other recess <NUM> of circular top surface <NUM> may be configured to reflect the laser beam substantially horizontally towards cylindrical side wall section <NUM>, thereby enabling horizontal outgoing beam <NUM>.

The laser beam may be refracted when it hits circular bottom surface section <NUM> on the way to at least one other conical recess <NUM>. Nevertheless, as at least one other conical recess <NUM> of circular top surface <NUM> may be configured to reflect the laser beam substantially horizontally towards cylindrical side wall section <NUM> and cylindrical side wall section <NUM> may have a surface in a vertical direction. The laser beam may not be refracted when it hits cylindrical side wall section <NUM>. Thus, the laser beam may be directed out of lens <NUM> and horizontal outgoing beam <NUM> may be provided regardless of the tilting angle of MEMS mirror <NUM>. An outer surface of cylindrical side wall section <NUM> may be perpendicular to circular top surface <NUM> to make sure that outgoing beam <NUM> goes to a desired direction, i.e., there is no reflection due to cylindrical side wall section <NUM>.

<FIG> illustrates a second example in accordance with at least some embodiments of the present invention. MEMS mirror apparatus <NUM> may comprise lens <NUM>. In the example of <FIG>, components <NUM> - <NUM> of lens <NUM> may correspond to, and be configured similarly as, components <NUM> - <NUM> of lens <NUM> in <FIG>, respectively. In addition, components <NUM> - <NUM> of MEMS mirror apparatus <NUM> may correspond to, and be configured similarly as, components <NUM> - <NUM> of MEMS mirror <NUM> in <FIG>, respectively. Outgoing beam is denoted by <NUM> similarly as outgoing beam <NUM> in <FIG> as well.

In addition, in the example of <FIG>, bottom surface <NUM> may comprise inclined bottom surface section <NUM>. Inclined bottom surface section <NUM> may extend at a downward angle from circular bottom surface section <NUM> to cylindrical bottom surface section <NUM>. That is to say, cylindrical bottom surface section <NUM> and circular bottom surface section <NUM> may not be at the same level, i.e., bottom surface <NUM> may not be completely planar. For instance, circular bottom surface section <NUM> may be above cylindrical bottom surface section <NUM>. Inclined bottom surface section <NUM>, or an inclined surface of inclined bottom surface section <NUM>, may be configured to reflect a laser beam towards cylindrical side wall section <NUM> in the example of <FIG>.

Similarly as in the example of <FIG>, in the example of <FIG> laser source <NUM> may be configured to emit a laser beam towards cylindrical bottom surface section <NUM> and conical side wall section <NUM> of side wall <NUM>. Conical side wall section <NUM> may be referred to as an inclined section as well. Conical side wall section <NUM>, i.e., inclined surface <NUM> of conical side wall section <NUM>, may be configured to reflect the laser beam towards conical recess <NUM> of circular top surface <NUM>. Conical recess <NUM>, i.e., inclined surface <NUM> of conical recess <NUM>, may be configured to reflect the laser beam further towards circular bottom surface section <NUM> of bottom surface <NUM> and MEMS mirror <NUM>. MEMS mirror <NUM> may be then configured to direct the laser beam towards circular top surface <NUM>.

The laser beam may be reflected from circular top surface <NUM>, i.e., a surface of circular top surface <NUM>, towards inclined bottom surface section <NUM> of bottom surface <NUM>. As inclined bottom surface section <NUM> of bottom surface <NUM> may extend at a downward angle from circular bottom surface section <NUM> to cylindrical bottom surface section <NUM>, inclined bottom surface section <NUM> of bottom surface <NUM> may be configured to reflect the laser beam towards cylindrical side wall section <NUM>.

As inclined bottom surface section <NUM> of bottom surface <NUM> may be configured to reflect the laser beam substantially horizontally towards cylindrical side wall section <NUM>, the laser beam may not be refracted when it hits cylindrical side wall section <NUM>. Thus, the laser beam may be directed out of the lens and horizontal outgoing beam <NUM> may be provided regardless of the tilting angle of MEMS mirror <NUM>.

In some embodiments, inclined bottom surface section <NUM> of bottom surface <NUM> may not be configured to reflect the laser beam substantially horizontally towards cylindrical side wall section <NUM>. In such a case, the laser beam may be refracted when it hits cylindrical side wall section <NUM>, but inclined bottom surface section <NUM> of bottom surface <NUM> may be anyway configured to reflect the laser beam so that outgoing beam <NUM> may be substantially horizontal after hitting cylindrical side wall section <NUM>.

In the example of <FIG>, cylindrical bottom surface section <NUM> may extend from cylindrical side wall section <NUM> to inclined bottom surface section <NUM> and inclined bottom surface section <NUM> may further extend to circular bottom surface section <NUM>. That is to say, inclined bottom surface section <NUM> may be between cylindrical bottom surface section <NUM> and circular bottom surface section <NUM>. As shown in <FIG> and <FIG>, in some embodiments conical side wall section <NUM> may go around lens <NUM>.

<FIG> illustrates one realization of the second example lens, shown from above, in accordance with at least some embodiments of the present invention. That is to say, <FIG> illustrates a top view of lens <NUM> of <FIG>. <FIG> shows circular lens <NUM> and circular top surface <NUM>, side wall <NUM>, conical side wall section <NUM> and conical recess <NUM> of lens <NUM>. As demonstrated in the realization of <FIG>, in some embodiments of the present invention conical side wall section <NUM> and conical recess <NUM> may be symmetric with respect to circular lens <NUM>, thereby enabling operation of lens <NUM> in a sector of <NUM> degrees.

<FIG> illustrates a cross-sectional view of a third example lens in accordance with at least some embodiments of the present invention. MEMS mirror apparatus <NUM> may comprise lens <NUM>. In the example of <FIG>, components <NUM> - <NUM>, <NUM> and <NUM> - <NUM> of lens <NUM> may correspond to, and be configured similarly as, components <NUM> - <NUM>, <NUM> and <NUM> - <NUM> of lens <NUM> in <FIG>, respectively. In addition, components <NUM> - <NUM> of MEMS mirror apparatus <NUM> may correspond to, and be configured similarly as, components <NUM> - <NUM> of MEMS mirror <NUM> in <FIG>, respectively. Outgoing beam is denoted by <NUM> similarly as outgoing beam <NUM> in <FIG> as well.

In the example of <FIG>, side wall section <NUM> and recess <NUM> may not be conical. Side wall section <NUM> may be referred to as an inclined section of side wall <NUM> as well. Side wall section <NUM> and recess <NUM> may have, i.e., comprise, inclined surfaces <NUM> and <NUM>, respectively. As shown in <FIG>, side wall section <NUM> may not go around lens <NUM>. Instead, side wall section <NUM> may be on a part of a circumference of lens <NUM>, i.e., a circumference of circular top surface (<NUM>).

Circular top surface <NUM> may be provided with recess <NUM> having inclined surface <NUM> extending from circular top surface <NUM>. Moreover, side wall <NUM> may have inclined section <NUM> extending from circular top surface <NUM> as well. Inclined section <NUM> may be inclined towards recess <NUM> and inclined surface <NUM> may be inclined outward of recess <NUM> towards inclined section <NUM>.

<FIG> illustrates one realization of the third example lens, shown from above, in accordance with at least some embodiments of the present invention. <FIG> illustrates a top view of lens <NUM> of <FIG> and <FIG> also shows circular lens <NUM> and circular top surface <NUM>, side wall <NUM>, inclined section <NUM> and recess <NUM> of lens <NUM>. <FIG> demonstrates a realization, wherein inclined section <NUM> and recess <NUM> may not be circular and symmetric with respect to circular lens <NUM>. In such a case, inclined section <NUM> may be only at a location that corresponds to a location of laser source <NUM> and recess <NUM> may be at a location that corresponds to a location of MEMS mirror <NUM>.

As shown in <FIG>, in some embodiments, inclined section <NUM> and recess <NUM>, i.e., inclined surface <NUM> of recess <NUM>, may be on a same chord of lens <NUM>, i.e., on a same chord of circular top surface <NUM>. Moreover, inclined section <NUM> and recess <NUM>, i.e., inclined surface <NUM> of recess <NUM>, may be on a diameter of lens <NUM>, i.e., on a diameter of circular top surface <NUM>. In some embodiments, inclined section <NUM> may be planar.

Thus, in case of the realization of <FIG>, inclined section <NUM> and recess <NUM>, i.e., inclined surface <NUM> of recess <NUM>, enable operation of lens <NUM> in a sector of <NUM> degrees even without requiring that inclined section <NUM> and recess <NUM> would be conical, i.e., circular and symmetric around circular lens <NUM>. Hence, the benefit of the realization of <FIG> is that simple, cost-efficient cutting of lens <NUM> is enabled and consequently manufacturing of MEMS mirror apparatus <NUM> may be simplified.

At least some embodiments of the present invention find industrial application in MEMS mirrors.

Claim 1:
A Microelectrical System, MEMS, mirror apparatus (<NUM>), comprising:
- a lens (<NUM>, <NUM>, <NUM>) further comprising a circular top surface (<NUM>, <NUM>, <NUM>), the circular top surface (<NUM>, <NUM>, <NUM>) being provided with a recess (<NUM>, <NUM>, <NUM>) having an inclined surface (<NUM>, <NUM>, <NUM>) extending from the circular top surface (<NUM>, <NUM>, <NUM>) and a side wall (<NUM>, <NUM>, <NUM>) having an inclined section (<NUM>, <NUM>, <NUM>) extending from the circular top surface (<NUM>, <NUM>, <NUM>), wherein the inclined section (<NUM>, <NUM>, <NUM>) is inclined towards the recess (<NUM>, <NUM>, <NUM>) and the inclined surface (<NUM>, <NUM>, <NUM>) is inclined outward of the recess (<NUM>, <NUM>, <NUM>) towards the inclined section (<NUM>, <NUM>, <NUM>); and
- a MEMS mirror (<NUM>, <NUM>, <NUM>, <NUM>) and a laser source (<NUM>, <NUM>, <NUM>), wherein the MEMS mirror (<NUM>, <NUM>, <NUM>, <NUM>) and the laser source (<NUM>, <NUM>, <NUM>) are below the lens (<NUM>, <NUM>, <NUM>),
- wherein the MEMS mirror apparatus (<NUM>) is arranged such that a laser beam coming from one side of the lens,
from the laser source (<NUM>, <NUM>, <NUM>) below the lens (<NUM>, <NUM>, <NUM>), is
reflected from the inclined section (<NUM>, <NUM>, <NUM>) to the recess (<NUM>, <NUM>, <NUM>) of the circular top surface (<NUM>, <NUM>, <NUM>) while the inclined surface (<NUM>, <NUM>, <NUM>) of the recess (<NUM>, <NUM>, <NUM>) is configured to reflect the laser beam further to said one side of the lens (<NUM>, <NUM>, <NUM>) towards the MEMS mirror (<NUM>).