NL2035514B1

NL2035514B1 - Beacon Light optic

Info

Publication number: NL2035514B1
Application number: NL2035514A
Authority: NL
Inventors: Sjors Groeneveld Mischa; Leeuwangh Thomas
Original assignee: Orga Holding B V
Priority date: 2023-07-31
Filing date: 2023-07-31
Publication date: 2025-02-11
Also published as: WO2025029145A1

Abstract

Title: Beacon light optic The present disclosure relates a beacon light optic comprising at least a first light source and a light transmitting element arranged in a recess in the bottom side of the light transmitting element. The light transmitting element further comprises an exit surface for outputting light, an upper side haVing a top reﬂector for redirecting light to the exit surface, and a collimator comprising a first TIR collimator surface and a second TIR collimator surface opposite the first TIR collimator surface. The first entrance surface, the first TIR surface and second TIR surface are configured for directing light from the first light source to the top reﬂector. The top reﬂector comprises at least a first surface segment and a second surface segment, and the first and second surface segment have a different shape. Alternatively, the first and second surface segment have a planar shape and wherein the first surface segment is inclined with respect to the second surface segment. Fig.2

Description

P185316NL00

Title: Beacon Light optie

Field of the disclosure

The present disclosure relates to beacon light optics and beacon lights making use of such beacon light optics, for example beacon lights for marking obstructions that may present a hazard for aircraft or marine vessel navigation, or for providing specific information to an aircraft or marine vessel through light signs.

Background

Beacon lights are for example used for indicating a presence of obstacles such as towers, wind turbines, and any other object that can cause hazard to aviation. The beacon lights help for example pilots to identify and 16 navigate around potential obstacles.

In a further application, beacon lights are for example used on a helideck to indicate helideck operational statuses to the helicopter pilots approaching the deck. Typically, blue, amber and red lights are used for this application.

A beacon light optic is a component of a beacon light and generally comprises at least a light source and a light transmitting element for transmitting light from the light source to an exit surface. For example, in publication WO 2015/099533, an example of a beacon light optic is described wherein the beacon light optic comprises an array of light emitting elements and a light transmitting element for transmitting the light from each of the light emitting elements to one or more exit windows. The light transmitting element is a so-called total internal reflection, TIR, element comprising an entrance surface for receiving light from the array and at least one exit surface for outputting light from the array. In this example, the light emitted by the beacon light is propagating at an angle of 0° with respect to the horizon. As described, the entrance surface defines a recess in the light transmitting element and the array is arranged in the recess such that a light emitting surface of each the light emitting elements is facing the entrance surface. In this way, a compact beacon light optic structure is obtained.

A beacon light can be formed by one beacon light optic or, alternatively, multiple beacon light optics can be combined to for example cover a light emission over a 360° azimuthal angle.

Beacon lights must comply with specific requirements outlined by aviation regulatory bodies. These regulations define parameters such as light intensity, colour, flash rate, and beam distribution. These parameters depend on the specific application the beacon lights are used for.

For example, for beacon lights used during helicopter hoist operations generally a green status light is used, which is flashing or steady burning, to indicate the hoist status.

On the other hand, for example for search and rescue operations a steady burning red light and infrared light is generally used to indicate target turbines in emergency cases.

All these applications of beacon lights have specific requirements in terms of light intensity and the angular distribution of the light emitted.

In view of the multiple applications, various designs of beacon lights and associated optics exist to comply with the specific requirements of the applications the beacon lights are to be used for.

As a result, in view of the severe regulatory requirements and the multiple applications, design and manufacturing costs of beacon lights can be high.

Hence, there is room for improving beacon light optics and improving the manufacturing method for producing these devices.

Summary

It is an object of the present disclosure to provide a compact and robust beacon light optic having a simplified and standardized design that can be used for multiple applications. More specifically, a beacon light optic design that easily can be adapted for specific applications requiring different requirements in terms of light intensity and angular distribution of the light emitted by the beacon optic.

The present disclosure is defined in the appended independent claims. The dependent claims define advantageous embodiments.

According to first aspect of the disclosure, a beacon light optic is provided.

The beacon light optic comprises at least a first light source and a light transmitting element. The light transmitting element comprises a bottom side having a first entrance surface for receiving light from the first light source, and wherein the first entrance surface is defining a first recess in the light transmitting element for receiving the first light source. The light transmitting element further comprises an exit surface for outputting light, an upper side, opposite the bottom side, having a top reflector configured for redirecting light to the exit surface, and a collimator, located between the bottom side and the upper side, having a first TIR collimator surface and a second TIR collimator surface opposite the first TIR collimator surface. The beacon light optic is characterized in that the first entrance surface, the first TIR surface and the second TIR surface are configured for directing light from the first light source to the top reflector, and in that the top reflector comprises at least a first surface segment and a second surface segment, and wherein the first and second surface segment have a different shape. Alternatively, wherein the first and second surface segment have a planar shape and wherein the first surface segment is inclined with respect to the second surface segment.

A TIR surface is a total internal reflecting surface.

In embodiments, the first surface segment has a planar shape and the second surface segment has a non-planar shape or the first surface segment has a non-planar shape and the second surface segment has a planar shape. The non-planar shape comprises for example a convex surface portion or a concave surface portion.

Advantageously, by providing a top reflector comprising at least a first and a second surface segment having different shapes or being inclined with respect to each other, the surface segments can be configured to redirect light to the exit surface at well-defined angles so as to output light at the exit surface within a predefined angular distribution, e.g. predefined by regulations. Indeed, by either shaping or orientating the surface segments, light will be deflected differently by the top reflector and hence light can be outputted by the exit surface at different angles.

Advantageously, by specifying the number of surface segments and specifying the shape, orientation and/or size of each of the segments, any light distribution can be outputted by the beacon light optic in range between for example -20° and 90° with respect to a reference plane.

In embodiments, the second surface segment is adjoining the first surface segment.

Typically, the light transmitting element is a solid body, preferably a single-piece solid body, made of a transparent material.

Generally, the first and second TIR collimator surface comprises respectively a first and second parabolic-shaped portion.

In embodiments, the entrance surface is configured for splitting light received from the first light source into at least a first, a second and a third light beam, and for directing the first beam to the first TIR collimator surface, directing the second beam to the top reflector, and directing the third beam to the second TIR collimator surface, and wherein the first TIR collimator surface is configured for redirection the first beam to the top reflector and the second TIR collimator surface is configured for redirecting the third beam to the top reflector.

Advantageously, by providing an entrance surface that is splitting the light of the light source into three beams, the shape of the entrance 5 surface can be simplified and the entrance surface can be specified by three surfaces: a central surface and two sides surfaces. These three surfaces are not complex and hence this facilities the manufacturing of the light transmitting element.

For example, in embodiments, the first entrance surface comprises a central entrance surface configured for forming the second light beam, a first side entrance surface and a second side entrance surface configured for forming respectively the first and third light beam.

In exemplary embodiment, the top reflector comprises at least a first, a second and a third surface segment, and wherein the entrance surface is configured for splitting light received from the first light source into at least a first, a second and a third light beam, and for directing the first beam to the first TIR collimator surface, directing the second beam to the second surface segment, and directing the third beam to the second TIR collimator surface. The first TIR collimator surface is configured for redirection at least a first part of the first beam to the first surface segment and the second TIR collimator surface is configured for redirecting at least a first part of the third beam to the third surface segment. The first and second surface segment have a different shape and the third surface segment has a shape that is different from a shape of the first surface segment and/or different from a shape of the second surface segment.

In this exemplary embodiment, the first and third surface segment have for example a planar shape and the second surface segment has a non- planar surface. Preferably, the second surface segment is adjoining the first and third surface segment.

In further embodiments, the top reflector comprises at least a first, a second and a third surface segment and wherein each of the surface segments has a planar shape and wherein at least a first surface segment is inclined with respect to a second surface segment and/or inclined with respect to the third surface segment.

In embodiments comprising at least a first, second and third surface segment, the exit surface is for example adjoining the first TIR collimator surface and the first surface segment, and the second TIR collimator surface is adjoining the third surface segment.

Preferably, the first light source comprises a plurality of light emitting elements elongating along a longitudinal axis so as to form a linear array of light emitting elements.

Generally, the surface segments are elongating along an axis parallel with the longitudinal axis.

In embodiments, the beacon light optic according comprises a reference plane and the light transmitting element is configured for outputting a light pattern having an angular distribution defined with respect to the reference plane.

In embodiments, the exit surface is for example planar and inclined with respect to the reference plane. In exemplary embodiments, the exit surface is for example inclined by an angle of 90° with respect to the reference plane. In other embodiments, the exit surface is inclined with respect to the reference plane by an angle different from 90°, for example by an angle between 45° and 90°. In further embodiments, the exit surface is non-planar.

Generally, for embodiments comprising surface segments having a planar shape, the surface segments having a planar shape are inclined with respect to the reference plane, preferably the planar surface segments are inclined with an angle comprised in a range between 20° and 60°, more preferably with an angle comprised in a range between 35° and 55°, with respect to the reference plane.

Advantageously, with the light optic according to the present disclosure, a single light transmitting element can be used to accommodate multiple different type of light sources, which results in a compact design.

In embodiments, two light sources can for example be accommodated in the light transmitting element. In these embodiments, the beacon light optic comprises a second light source, and wherein the bottom side of the light transmitting element has a second entrance surface for receiving light from the second light source, wherein the second entrance surface defines a second recess in the light transmitting element, and wherein the second light source is arranged in the second recess.

In other embodiment, for example three light sources can be accommodated in the light transmitting element. In these embodiments, the beacon light optic further comprises, besides the first and second light source, a third light source, and wherein the bottom side of the light transmitting element has a third entrance surface for receiving light from the third light source, wherein the third entrance surface defines a third recess in the light transmitting element, and wherein the third light source is arranged in the third recess.

The present disclosure also relates to a beacon light comprising at least one beacon light optic as presently claimed. For example a beacon light for marking obstructions presenting a hazard to aeronautical or marine navigation, a helihoist beacon light, a helideck monitoring system light for placing on a helideck or a helideck status light for placing on a helideck. In embodiments, the beacon light comprises at least one beacon light optic as discussed above and at least one additional light optic, wherein the additional light optic comprises an additional light source and wherein the additional light optic is configured for emitting light with a different angular light distribution when compared to a light distribution emitted by the at least one beacon light optic.

Short description of the drawings

These and further aspects of the present disclosure will be explained in greater detail by way of example and with reference to the accompanying drawings in which:

Fig.1 shows a cross-sectional view of a first embodiment of a beacon optic according to the present disclosure,

Fig.2 illustrates light trajectories through the beacon optic shown on Fig.1.

Fig.3 shows a cross-sectional view of a bottom portion of a light transmitting element illustrating a first recess defined by a first entrance surface,

Fig.4 shows a cross-sectional view of a second embodiment of a beacon optic according to the present disclosure,

Fig.5 shows a cross-sectional view of a third embodiment of a beacon optic according to the present disclosure,

Fig.6 is a schematic perspective view of the embodiment of Fig.5.

Fig.7 is a schematic perspective view of further embodiment of a beacon optic according to the present disclosure,

Fig.8 is a cross-sectional view, taken in a plane Z-Y, of the embodiment shown on Fig.7,

Fig.9 shows a cross-sectional view of a bottom portion of the light transmitting element illustrating a second recess defined by a second entrance surface,

Fig.10 shows a cross-sectional view of a bottom portion of the light transmitting element illustrating a third recess defined by a third entrance surface,

Fig.11 is a perspective view of a light beacon comprising a plurality of beacon light optics.

The drawings of the figures are neither drawn to scale nor proportioned. Generally, identical components are denoted by the same reference numerals in the figures.

Detailed description of embodiments

The present disclosure will be described in terms of specific embodiments, which are illustrative of the disclosure and not to be construed as limiting. It will be appreciated by persons skilled in the art that the present disclosure is not limited by what has been particularly shown and/or described and that alternatives or modified embodiments could be developed in the light of the overall teaching of this disclosure. The drawings described are only schematic and are non-limiting.

Use of the verb "to comprise", as well as the respective conjugations, does not exclude the presence of elements other than those stated. Use of the article "a", "an" or "the" preceding an element does not exclude the presence of a plurality of such elements.

Furthermore, the terms first, second and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a sequence, either temporally, spatially, in ranking or in any other manner. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that the embodiments of the disclosure described herein are capable of operation in other sequences than described or illustrated herein.

Reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure or characteristic described in connection with the embodiments is included in one or more embodiment of the present disclosure. Thus, appearances of the phrases

“in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment, but may. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner, as would be apparent to one ordinary skill in the art from this disclosure, in one or more embodiments.

According to a first aspect of the disclosure, a beacon light optic is provided.

With reference to Fig.1, Fig.2, Fig.4 and Fig.5, cross-sectional views of exemplary embodiments of a beacon light optic 1 according to the present disclosure are shown. Fig.6 and Fig.7 are perspective views of exemplary embodiments of beacon light optics.

Generally, a light pattern outputted by the beacon light optic 1 is emitted with respect to a reference plane, e.g. a horizontal plane. In the present disclosure, the reference plane is indicated on the figures as a plane

X.Y formed by orthogonal axes X and Y. In Fig.1, Fig.2, Fig.3 and Fig.4, the Y axis is an axis perpendicular to the X and Z axes shown on the figures.

The beacon light optic according to the present disclosure comprises at least a first light source 2a and a light transmitting element 3 for outputting the light of the light source. Typically, the outputted light pattern is emitted according to a predefined angular distribution with respect to the reference plane, i.e. a predefined range of angles with respect to the reference plane and a corresponding predefined intensity. These predefined angular distributions are specified by regulations, e.g. from aviation regulatory bodies.

In embodiments, the light transmitting element 3 is a solid body made of a transparent material, for example manufacturing from glass or a suitable plastic material, such as PC, PMMA. In embodiments, the light transmitting element is manufactured by injection moulding. The light emitting element can be made as a single-piece solid body or alternatively,

multiple sub-elements of the light emitting element can be assembled together.

In embodiments, the light transmitting element 3 comprises a supporting element 7 that facilitates positioning of the light transmitting element on a supporting structure.

In embodiments, the first light source 2a comprises a plurality of light emitting elements elongating along a longitudinal axis L so as to form a linear array of light emitting elements as schematically illustrated on

Fig.6. The longitudinal axis L is parallel with the reference plane X-Y. A light emitting element is for example a light-emitting diode, LED. In other embodiments, the light source corresponds for example to a single LED.

The light transmitting element comprises a bottom side 14 and an upper side 15 opposite the bottom side, and a collimator 4 located between the bottom and upper side. The collimator 4 comprises, as illustrated for example on Fig.1 and Fig.2, a first TIR collimator surface 4a and a second

TIR collimator surface 4b opposite the first TIR collimator surface. A TIR surface is a total internal reflecting surface.

In embodiments, the collimator 4 of the light emitting element 3 can have a parabolic shape, more specifically a cross section between a cross-sectional plane X-Z and the first and second TIR collimator surface comprises respectively a first and a second parabolic-shaped portion. The cross-sectional plane X-Z is a plane that is perpendicular to the reference plane X-Y and perpendicular the longitudinal plane Y-Z.

The bottom side 14 of the light transmitting element 3 has a first entrance surface 21 for receiving light from the first light source, and which as illustrated in more detail on Fig.3, defines a first recess 5a in the light transmitting element. The first light source 2a is arranged within the first recess 5a. Hence, the recess has to be construed as a cavity made in the bottom side of the light transmitting element and the size and shape of the recess depends on the size and shape of the light source. The first light source is arranged in the first recess such that a light emitting surface of the first light source is facing the entrance surface of the light emitting element. In this way, when the first light source 2a is activated, light will enter the light transmitting element 3 through the entrance surface 21.

As the first light source 2a is an array of light emitting elements elongating along the longitudinal axis L, also the first recess 5a in the light transmitting element is elongating along the longitudinal axis L.

The light transmitting element further comprises, as illustrated for example on Fig.1 and Fig.2, an exit surface 6 for outputting light, and the exit surface, in this example, is planar and perpendicular with the reference plane X-Y. Hence, in this example, the exit surface, is parallel with the longitudinal plane Y-Z shown on Fig.1 and Fig.2, perpendicular to the reference plane X-Y. In other embodiments, the exit surface can be inclined with respect to the reference plane by an angle different from 90°, for instance to shift the output light by a couple of degrees when compared to using an exit surface at 90°. Hence, more generally, the exit surface can be inclined by an angle between 45° and of 90° with respect to the reference plane, preferably by an angle between 80° and 90°. The exit surface is also not necessarily planar, in some embodiments the exit surface can be curved and have a convex or concave surface portion.

The upper side 15 of the light transmitting element 3 comprises a top reflector 10 for redirecting light to the exit surface 6.

The first entrance surface 21, the first TIR surface 4a and the second TIR surface 4b are configured for directing light from the first light source 2a to the top reflector 10.

For example, for the embodiments, schematically illustrated on

Fig.2, Fig.4, and Fig.5, the first entrance surface is configured for splitting light received from the first light source into a first B1, a second B2 and a third B3 light beam, and for directing the first light beam B1 to the first TIR collimator surface 4a, directing the second light beam B2 to the top reflector

10, and for directing the third light beam B3 to the second TIR collimator surface 4b.

As further schematically illustrated on Fig.2, the first TIR collimator surface 4a is configured for redirection the first light beam B1 to the top reflector and the second TIR collimator surface 4b is configured for redirecting the third light beam B3 to the top reflector 10. In other words, with the beacon optics according to the present disclosure, all light from the first light source is sent on the top reflector 10 for being redirected to the exit surface.

The concept of splitting the light of the first light source into three beams simplifies the geometry of the entrance window and hence simplifies the manufacturing of the light emitting element. Indeed, as illustrated on

Fig.3, showing a cross-sectional view of the first recess ba, for splitting the light from the first light source into a first, second and third light beam, the first entrance surface 21 is formed by three surfaces: a central entrance surface 21a configured for forming the second light beam B2, a first side entrance surface 21b and a second side entrance surface 21c configured for forming respectively the first B1 and third B3 light beam.

The beacon optic according to the present disclosure is characterized in that the top reflector 10 comprises a plurality of surface segments or at least a first and a second surface segment. In embodiments, the second surface segment is adjoining the first surface segment. In the embodiments shown on Fig.1, Fig.2 and Fig.4, the top reflector comprises three surface segments: a first S1, a second S2 and a third S3 surface segment. In this embodiment, the first surface segment is adjoining the second surface segment and the second surface segment is adjoining the third surface segment. In the embodiment shown on Fig.5, the top reflector comprises nine surface segments, S1 to S9, as further illustrated on Fig.6, which is a perspective view of the embodiment shown on Fig.5.

A surface segment of the top reflector 10 has to be construed as a portion of the surface of the top reflector that, as discussed below in more detail, is configured for redirecting received light to the exit surface. The redirection occurs by reflection off the surface segment. In embodiments, the surface segments are total internal reflection, TIR, surfaces.

In the embodiments shown on Fig.6 and Fig.7, the surface segments of the top reflector 10 are elongating along an axis parallel with the longitudinal axis L.

By providing for example a first S1 and a second S2 surface segment having a different shape, e.g. one surface segment having a planar shape, and another surface segment having a non-planar shape, light received on the first and second surface segment will be redirected to the exit surface at different angles and hence light outputted by the exit surface can propagate at different angles.

Typically, a surface segment is configured such that light when redirected from the surface segment to the exit surface, is exiting the exit surface and propagating at an angle with respect to the reference plane comprised within a pre-defined angular range. Each surface segment can be optimized such that light exiting the exit surface is propagating at a given angular range predefined for each of the surface segments. The overall light emitted by the beacon light optic is hence a combination of light that was redirected by each of the surface segments of the top reflection surface 10.

Alternatively, instead of using surface segments having a different shape, surface segments wherein each segment has a planar shape can also be used, but in this case, the inclination of the surface segments with respect to each other has to be different. Indeed, if two surface segments have an inclination with respect to each other, the light received on the two segments is redirected to the exit surface at different angles and light exiting the exit surface will propagate at different angles. A first surface segment having a planar shape being inclined with respect to a second surface segment having a planar shape implies that the surfaces of the first and second surface segment are not co-planar.

The present disclosure is not limited to a specific number of surface segments. In embodiments, the top reflector comprises a first and a second surface segment, while in other embodiments the top reflector comprises a plurality of surface segments.

For example, in an embodiment comprising only a first and a second surface segment, the first beam can, following reflection on the collimator, be directed to the first surface segment, the second light beam can be directed to the second surface segment and the third light beam can, following reflection on the collimator, also be directed to the second surface segment,

Hence, more generally, the top reflector 10 comprises at least a first S1 and a second S2 surface segment and wherein the first and second surface segment have a different shape. Alternatively, instead of having two surface segments with a different shape, the first and second surface segment have both a planar shape and the first surface segment is inclined with respect to the second surface segment.

In this way, light reflected and redirected from the first segment

S1, when exiting the exit surface, is propagating at an angle with respect to the reference plane X-Y comprised within a first angular range, and light reflected and redirected from the second segment S2, when exiting the exit surface 6, is propagating at an angle with respect to the reference plane X-Y comprised within a second angular range.

The first angular range and second angular range are different.

This means that there are angles comprised in the first angular range that are not comprised in the second angular range, and vice versa. In this way, the overall angular range of the beam optic is increased when compared to a beacon optic that does not comprises a top surface segment that is divided in different surface segments having a different shape or having a planar shape but with an inclination with respect to each other.

In embodiments, the first and second angular range can partly overlap, while in other embodiments the two angular ranges do not overlap.

In other words, the first angular range is comprised between K° and L°, with K <L and the second angular range is comprised between M° and N°, with M <N, and wherein M > K, preferably M > L/2, more preferably M > L.

In some embodiments, the general idea is that the beacon optic provides for a main beam that is propagating mainly parallel and/or slightly inclined with respect the reference plane and additionally provides for a secondary beam or a tail beam, generally with a broader angular distribution, wherein light is propagating at larger angles when compared to the main beam, e.g. at angles larger than 10° or even larger than 45° or even at angles up to 90°, i.e. a beam pointing upwards with respect to the reference plane. Generally, depending on the regulations, the intensity of the main beam is defined to be larger than the secondary beam.

In embodiments, the angular values for K, M and N, related to a first and second segment discussed above, are for example as follows: K> - 25°, preferably K > -10°, more preferably K > 0° and M > 10°, preferably M > 15°, more preferably M > 20°, and N < 90°.

In embodiments, the angular value for L is for example as follows:

L < 30°, preferably L < 20°, more preferably L< 15°,

For embodiments wherein the top reflector comprises a first S1, a second S2 and a third S3 segment, as illustrated on Fig.1, Fig.2 and Fig.4, the entrance surface is configured for redirecting the second light beam B2 to the second surface segment 12 of the top reflector 10. In the present example, the second light beam B2 follows a trajectory in a direction of the Z axis perpendicular to the reference plane X-Y. In this embodiment, the first TIR collimator surface 4a is configured for redirection at least a first part of the first light beam B1 to the first surface segment and the second

TIR collimator surface 4b is configured for redirecting at least a first part of the third light beam B3 to the third surface segment. In this example, the second surface segment is adjoining the first and third surface segment.

In the embodiment shown on Fig.2, the first and third surface segment are planar and the second surface segment is not planar. In other words, in this example, not only the first and second surface segment have a different shape but also the third surface segment has a shape that is different from a shape of the second surface.

As further illustrated on Fig.2, with the third surface segment S3, light reflected from the third surface segment S3, when exiting the exit surface 6, is propagating at an angle with respect to the reference plane comprised within a third angular range, equal or different from the first angular range, or alternatively equal or different from the second angular range.

In other words, the third angular range can be comprised in an angular range with respect to the reference plane, between Q° and R°, with

Q<R, and the first angular range can be comprised between K° and L°, with K<L, and wherein Q > Kand R> L, or wherein Q <Kand R <L, or wherein Q<KandR>L.

For the embodiment shown on Fig.2, as schematically illustrated, some of the light rays redirected by the second surface segment S2 are for example outputted at an angle B larger than 45°, while some of the light rays redirected by the first segment S1 are outputted at an angle a of about 0°, e.g. between 1° and 3°, and some of the light rays outputted by the third surface segment S3 are outputted at an angle y larger than 1° but smaller than 15°. Hence, in this example, there are three different angular distributions that contribute to the overall light distribution outputted by the beacon light optic. The angles shown on the figures are only for illustrative purposes. What the exact angular distributions are depend on the application the beacon light is used for, as will be discussed in more detail below.

The embodiment of the beacon optic shown on Fig.2 can for example be used for a helihoist light. Indeed, for safe offshore helicopter hoists, wind turbine platforms must be equipped with a helicopter hoist status light, also named helihoist light, to indicate the status of the hoist.

For example, a flashing green light indicates that the wind turbine is preparing to enter safe mode and allow hoisting operations, while a steady green signal tells the pilot that the wind turbine is in safe mode and that winching can commence. As mentioned above regulatory regulations specify requirements in terms of intensity angular range for the helicopter hoist light. These regulations specify the minimum and maximum light intensities for a given angular range, with respect to the horizontal plane, namely intensities between 0° and 2°, intensities for an angular range from 2° to 10°, and intensities for an angular range of 10° to 90° are specified.

With an embodiment of a beacon optic as shown on Fig.2, the first, second and third segment of the reflection top surface can be optimized to obtain the angular light distribution required for the helihoist light. In other words, with a single beacon light optic all required light angular ranges and intensities can be obtained.

The person skilled in the art will adapt the number of segments and the size, shape and/or orientation with respect to the reference plane of the segments such that the light outputted at the exit surface fulfils the regulatory requirements for a specific application, such as for example for a helihoist light or any other type of beacon light.

To make the angular distributions associated to the first and second surface segment different from each other, multiple options are possible and the person skilled in the art will select the solution most appropriate option for a given application.

A first option is for example that at least the first surface segment has a shape that is different from the shape of the second surface segment.

A second option is for example that the first surface segment is inclined with respect to the second surface segment, i.e. the first surface segment is inclined at a first angle with respect to the reference plane and the second surface segment is inclined at a second angle with respect to the reference plane different from the first angle. Generally, for this second option the surface segments are planar.

In embodiments, the first and/or the second segment is a non- planar surface. Different non-planar shapes for the surface segments can for example be defined by different spline functions. For example, a shape of the first surface segment can be specified with a first spline function and/or a shape of the second surface segment can be specified with a second spline function. A spline function is a function, well known in the art, comprising a combination of polynomials. The spline function allows to easily define different shapes.

In embodiments, the first surface segment can be planar and the second surface segment can be non-planar or alternatively the first surface segment can be non-planar and the second surface segment can be planar.

In embodiments, the second surface segment can comprise a convex surface portion or a concave surface portion. By selecting a convex or a concave surface portion, the light can either be focussed or defocussed.

The embodiment of a beacon light optic 1 shown on Fig.4 is similar to the embodiment shown on Fig.2 in the sense that the top reflector 10 also comprises three surface segments S1,S2 and S3, and that the first and third surface segment are planar and the second surface segment is non-planar.

The difference with the embodiment shown on Fig.2 is that the surface segments of the top reflector are specifically adapted to fulfil the regulatory requirements of another beacon light, namely for a helideck beacon light.

Also in this embodiment, three light distributions resulting from the use of three surface segments can be distinguished and are indicated in Fig.4 by the letters a, I! and |. Different type of helideck beacon lights exists, for example a monitoring system status light and a helideck status light.

A helideck status light tells a helicopter pilot not to land on the helideck during conditions deemed to be hazardous for the helicopter, its occupants or others. A hazard could, for example, be the release of gas that might constitute an explosion hazard, or the presence of an obstruction or personnel on or near the helideck.

On the other hand, the monitoring system status is a light for indicating the helideck operational status so as to provide information directly to the helideck crew and helicopter flight crew.

Both the monitoring system status and the helideck status light have specific requirements in terms of light distribution, as implied by regulations.

For the helideck status light, requirements are specified for the light distribution between 0° and 2°, between 2° and 10° and between 10° to 90°,

Similarly, for the helideck monitoring system status light, requirements for the light distributions are specified for a distribution between 5° and 15° and a distribution between 15 and 90°.

Advantageously, with the beacon light optic as discussed above, a monitoring system status and a helideck status light can be provided that covers the entire required light distribution with a single beacon light optic.

As discussed above, the person skilled in the art will define the number of segments, the size and/or shape and/or orientation of the surface segments such that the resulting light exiting the exit surface has a light distribution with respect to the reference plane that fulfils the regulatory requirements for a helideck status light or monitoring system status light.

For example for the beacon light optic embodiment having three surface segments as shown on Fig.4, the skilled person will adapt the surface segments for obtaining a specific light pattern by adjusting the size and/or orientation of the first and third planar surface segment and/or modifying the spline function defining the shape of the second non-planar surface segment.

For the embodiments shown on Fig.1, Fig.2 and Fig. 4, the first S1 and third S3 surface segment has a planar shape and these segments are inclined with respect to the reference plane X-Y. For example, the first and third surface segment are inclined with an angle between 20° and 60°, more preferably with an angle between 35° and 55° with respect to the reference plane. In this example, the second surface segment S2 has a non- planar surface. Hence, the shape of the second surface segment 1s different from the shape of the first and third segment.

For the embodiment shown on Fig.6, which is perspective view of the embodiment shown on Fig.5, the top reflection surface 10 comprises nine surface segments S1 to S9. These surface segments are planar but oriented at different angles with respect to the horizontal plane. In other words, each planar surface segment 1s inclined with respect to a neighbouring planar surface segment. For example, a first surface is inclined with respect to a second neighbouring surface segment by an angle comprised in a range between 0.01° and 5°, preferably in a range between 0.02° and 5°, more preferably in range between 0.02° and 3°. Remark that as, in this example, the relative inclinations between the various surface segments are small, the inclinations between surface segments are not clearly visible on Fig.6.

In the example illustrated on Fig.6, some of the surface segments are oriented such that light is exiting the exit surface at an angle of about 0°, while other segments are oriented such that light is exiting the exit surface at an angle of about 3°.

The embodiment shown on Fig.5 and Fig.6 can for example be used for a medium intensity obstruction light. A medium intensity obstruction light is used to make high-rise structures like wind turbines, both onshore and offshore, towers, skyscrapers, bridges and offshore structures , more visible to passing aircraft. Depending on specific requirements, these aviation warning lights offer options that include steady or flashing red or white light or infra-red light, during day-time and night-time modes.

The medium intensity obstruction light typically emits a rather focussed beam at 0° with respect to the reference plane, generally the horizon, but by providing an additional angular distribution around 3°, by using a segmented top reflector, as discussed above, light pollution can be reduced.

In some embodiments wherein the top reflector comprises a first, second and third surface segment, as schematically illustrated on Fig.2, the first TIR collimator surface is configured for redirecting a second part of the first light beam B1 to the second surface segment S2, and/or wherein the second TIR collimator surface is configured for redirecting a second part of the third light beam B3 to the second surface segment S2. In this way, more light falls on the second surface segment, more precisely on the edges of the second surface segment. resulting in light deflections at further angles contributing to the second angular distribution.

On the other hand, in the embodiment shown on Fig.4, the entire first light beam B1, following reflection from the collimator, is directed towards the first segment surface and the entire third light beam B3, following reflection from the collimator, is directed towards the third segment surface.

For the embodiments discussed above and shown on Fig.2, Fig.3 and Fig.4, the exit surface is adjoining both the first TIR collimator surface and the first segment, and the second TIR collimator surface is adjoining the third segment.

With reference to Fig.7 and Fig.8, a schematic perspective view and a cross-sectional view are respectively shown of a further embodiment of a beacon light optic according to the present disclosure. Fig.8 is a cross- sectional view through the longitudinal plane Y-Z, perpendicular to the reference plane. In this embodiment, the beacon light optic comprises multiple light sources using the same light transmitting element 3.

The light transmitting element 3 of the beacon light optic 1 shown on Fig.7 and Fig.8 comprises a first recess ba for receiving the first light source 2a. A cross-sectional view through the X-Z plane, taken in the middle of the first recess, corresponds to the cross sectional view shown on

Fig.1 and Fig.2. Typically, the first light source 2a is, as discussed above, is an array of light emitting elements elongating along a longitudinal axis L.

The array of light emitting elements is schematically shown as a dotted line on these figures. The first light source 2a is for example a light source configured to emit a green light.

The beacon light optic shown on Fig.7 and Fig.8 further comprises a second light source 2b, and the bottom side of the light transmitting 3 element has a second entrance surface for receiving light from the second light source 2b. The second entrance surface defines a second recess 5b in the light transmitting element 3, and the second light source 2b is arranged in the second recess 5b. The second light source is for example a light source configured to emit a red light. In this example the beacon light comprises two red light sources 2b adjacent to the first light source 2a.

In embodiments, as illustrated on Fig.7 and Fig.8, the beacon light optic further comprises a third light source 2c. Hence, the bottom side of the light transmitting element 3 has a third entrance surface for receiving light from the third light source 2c , wherein the third entrance surface defines a third recess 5c in the light transmitting element, and wherein the third light source 2c is arranged in the third recess 5c. The third light source is for example a light source configured to emit an infrared light. In this example, the beacon light optic comprises two infra- red light sources positioned adjacent to the two red light sources.

In other words, the beacon light optic can comprise different types of light sources that are using the same light transmitting element.

As discussed above and illustrated on Fig.3 the first recess 5a in the light transmitting element is formed by a first entrance surface 21 that comprises a central entrance surface 21a, a first side entrance surface 21b and a second side entrance surface 21c¢ for forming the three light beams.

Similarly, for the second recess and the third recess for receiving the second and third light source, the entrance surfaces defining the recesses are formed by three surfaces.

With reference to Fig.9 and Fig.10 , a cross-sectional view of a bottom portion of the light transmitting element illustrating the second recess 5b defined by a second entrance surface 22, and a cross-sectional view of a bottom portion of the light transmitting element illustrating a third recess 5c defined by a third entrance surface 23, are shown. The second entrance surface 22 is formed by three surfaces 22a, 22b and 22c. The central surface 22b has a convex portion allowing to focus light upwards in a direction of the Z axis. The asymmetric shape of the surface 23a allows to give a specific direction to the light. The third entrance surface 23 is also formed by three surfaces: 23a, 23b and 23e. In this example, the central surface 23a has a concave portion, allowing to spread light over for instance more than one surface segment of the top reflector.

The shapes of the second and third entrance surface can be shaped such that the light outputted by the beacon optic originating from the second and third light source, in combination with the surface segments of the top surface segment 10, fulfil the specific regulatory requirements associated to the second and third light.

In embodiments, the first light source, and if applicable the second and third light source, comprises a central light axis perpendicular to the reference plane. However, the light source is generally not only emitting light at 0° but light is emitted within a cone having an angular opening, for example, as illustrated on Fig.5, the light source 2a is emitting light at an angular range between -80 and 80° with respect to the central light axis. In other embodiments, as illustrated on Fig.2 and Fig.4, the angular range is somewhat narrower and light is for example emitted in a cone having an angular opening between -60° and +60° with respect to the central light axis, or within any other suitable cone angle.

According a second aspect of the invention a beacon light is provided comprising at least one beacon light optic as discussed above.

Generally, the beacon light comprises besides the beacon light optic, a support structure supporting the beacon light optic, a cover for protecting the beacon light optic and a control device for controlling the beacon light.

In embodiments, the beacon light is a beacon light for marking obstructions presenting a hazard to aeronautical or marine navigation comprising at least one beacon light optic as discussed above.

More precisely, in embodiments, the beacon light is a helihoist beacon light comprising at least one beacon light optic.

In further embodiments, the beacon light is a helideck monitoring system light or a helideck status light for placing on a helideck.

In embodiments, the beacon light comprising at least one beacon light optic as discussed above and at least one additional light optic comprising an additional light source, and wherein the additional light optic is configured for emitting light with a different angular light distribution when compared to a light distribution emitted by the at least one beacon light optic. For example the additional light optic can be configured for emitting light at angles of 90° with respect to the reference plane X-Y.

For example if the light intensity obtained at larger angles, e.g. up to 90°, obtained with the beacon light optic discussed above is not sufficient, the additional light optic can contribute to the light intensity at large angles, especially to increase light intensity for angles around 90°.

In embodiments, the beacon light can comprise a plurality of beacon light optics as discussed above, and wherein the plurality of beacon light optics 1 are positioned in a circular configuration with the exit faces facing outwardly so as to propagate light over an azimuthal angle equal or larger than 90°, preferably an azimuthal angle equal or larger than 180°, more preferably an azimuthal angle of 360°. An example of such a type of beacon light 100 is shown on Fig.11. In this example a plurality of beacon optics 1 are mounted on a support structure 30 surrounded by a housing 40.

In embodiments, the beacon light is a medium intensity obstruction light comprising at least one beam light optic.

The present disclosure further relates to a helideck for helicopters, wherein the helideck comprises a plurality of beacon lights and wherein each of the beacon lights comprises at least one beacon light optic as discussed above.

Reference numbers

Cee

Claims

Conclusions

1. A beacon light optic comprising at least a first light source and a light transmitting element, the light transmitting element comprising: - a bottom side having a first input surface for receiving light from the first light source, and said first input surface defining a first recess in the light transmitting element for receiving said first light source, - an output surface for emitting light, - a top side, opposite the bottom side, having a top reflector adapted to redirect light to the output surface, - a collimator, located between the bottom side and the top side, having a first TIR collimator surface and a second TIR collimator surface opposite the first TIR collimator surface, characterised in that said first input surface, said first TIR surface and said second TIR surface are adapted to redirect light from said first light source to said top reflector, and said top reflector comprises at least a first surface segment and a second surface segment, and said first and second surface segment having a different shape, or alternatively, said first and second surface segments having a planar shape and said first surface segment being inclined relative to said second surface segment.

2. The beacon light optic of claim 1 wherein said first and second surface segments have different shapes and wherein said first surface segment has a planar shape and said second surface segment has a non-planar shape or wherein said first surface segment has a non-planar shape and said second surface segment has a planar shape.

3. The beacon light of claim 2 wherein said non-planar shape is specified with a spline function.

4. The beacon light optic of claim 1 wherein said first surface segment has a non-planar shape specified with a first spline function and said second surface segment has a non-planar shape specified with a second spline function different from the first spline function.

5. The beacon light optic according to any one of claims 2 to 4, wherein said non-planar shape comprises a convex surface portion or a concave surface portion.

6. The beacon light optic according to claim 1, wherein said first surface is inclined relative to said second surface segment by an angle comprised in a range between 0.01° and 5°, preferably in a range between 0.02° and 5°, more preferably in a range between 0.02° and 3°.

7. The beacon light optic according to any of the preceding claims wherein said input surface is arranged to split light received from the first light source into at least a first, a second and a third light beam, and for directing the first beam to said first TIR collimator surface, directing the second beam to said top reflector, and directing the third beam to said second TIR collimator surface, and wherein said first TIR collimator surface is arranged to redirect the first beam to the top reflector and the second TIR collimator surface is arranged to redirect the third beam to the top reflector.

8. The beacon light optic of claim 1 wherein said top reflector comprises at least a first, a second and a third surface segment, and wherein said input surface is configured to split light received from the first light source into at least a first, a second and a third light beam, and to direct the first beam to said first TIR collimator surface, direct the second beam to said second surface segment, and direct the third beam to said second TIR collimator surface, and wherein the first TIR collimator surface is configured to redirect at least a first portion of the first beam to the first surface segment and the second TIR collimator surface is configured to redirect at least a first portion of the third beam to the third surface segment, and wherein said first and second surface segments have different shapes and wherein said third surface segment has a shape different from a shape of the first surface segment and/or different from a shape of the second surface segment.

9. The beacon light optic of claim 8 wherein said first TIR collimator surface is adapted to redirect a second portion of the first beam to the second surface segment, and/or wherein said second TIR collimator surface is adapted to redirect a second portion of the third beam to the second surface segment.

10. The beacon light optic of claim 8 or claim 9 wherein said first and third surface segments have a planar shape and said second surface segment has a non-planar surface.

11. The beacon light optic of claim 10 wherein said non-planar shape of the second surface segment is specified with a spline function.

12. The beacon light optic of any of claims 8 to 11 wherein said second surface segment is adjacent to said first and third surface segments.

13. The beacon light optic of claim 8 or claim 9 wherein said first, second and third surface segments have a non-planar shape.

14. The beacon light optic of claim 1 wherein said top reflector comprises at least a first, a second and a third surface segment and wherein each of said surface segments has a planar shape and wherein at least the first surface segment is inclined relative to the second surface segment and/or inclined relative to the third surface segment.

15. The beacon light optic of claim 14 wherein said second surface segment is adjacent to said first and third surface segments, and wherein said first surface segment is inclined relative to said second surface segment and said third surface segment is inclined relative to said second surface segment, preferably said first and third surface segments are inclined relative to said second surface segment by an angle comprised in a range between 0.01° and 5°, preferably in a range between 0.02° and 5°, more preferably in a range between 0.02° and 3°

16. The beacon light optic of any of claims 8 to 15 wherein the output surface is adjacent to the first TIR collimator surface and the first surface segment, and the second TIR collimator surface is adjacent to the third surface segment.

17. The beacon light optic of any preceding claim wherein the first light source comprises a plurality of light emitting elements extended along a longitudinal axis (L) such that a linear array of light emitting elements is formed.

18. The beacon optic according to claim 17, wherein each of the surface segments is extended along an axis parallel to said longitudinal axis (L).

19. The beacon light optic according to any of the preceding claims comprising a reference plane (X-Y) and wherein the light-transmitting element is arranged to emit a light pattern with an angular distribution defined with respect to said reference plane.

20. The beacon light optic of claim 19 wherein the output surface is planar and inclined with respect to the reference plane.

21. The beacon light optic according to claim 19, wherein the output surface is inclined at an angle between 45° and/or 90° relative to the reference plane, preferably at an angle between 80° and

90°.

22. The beacon light optic according to any of claims 19 to 21, wherein the surface segments having a planar shape are inclined with respect to said reference plane, preferably the planar surface segments are inclined at an angle ranging between 20° and 60°, more preferably at an angle ranging between 35° and 55°, with respect to the reference plane.

23. The beacon light optic of any preceding claim wherein said first entrance surface comprises a central entrance surface adapted to form said second light beam, a first side entrance surface and a second side entrance surface adapted to form said first and third light beams respectively.

24. The beacon light optic of claim 23 wherein said central entrance surface has a convex shape and said first side entrance surface and second side entrance surface have a planar shape.

25. The beacon light optic according to any of the preceding claims, wherein said light transmitting element is a solid body, preferably a one-piece solid body, made of a transparent material.

26. The beacon light optic of any preceding claim wherein the first and second TIR collimator surfaces comprise a first and second parabolic-shaped portion, respectively.

27. The beacon light optic of any preceding claim comprising a second light source, and wherein the underside of said light transmitting element has a second input surface for receiving light from the second light source, said second input surface comprising a second recess in the light transmitting element, and said second light source being disposed in said second recess.

28. The beacon light optic of claim 27 comprising a third light source, and wherein the underside of said light transmissive element has a third input surface for receiving light from the third light source, said third input surface defining a third recess in the light transmissive element, and said third light source being disposed in said third white recess.

29. The beacon light optic of claim 28 wherein said first light source is configured to emit a green light, said second light source is configured to emit a red light and said third light source is configured to emit an infrared light source.

30. The beacon optic according to any of claims 1 to 7, wherein said second surface segment is adjacent to said first surface segment.

31. A beacon light for marking obstacles posing a hazard to air or marine navigation comprising at least one beacon light optical system according to any one of claims 1 to 30.

32. A heli-hoist beacon light comprising at least one beacon light optic according to any one of claims 1 to 30.

33. A helideck monitoring system light for placement on a helideck comprising at least one beacon light optic according to any one of claims 1 to 30.

34. A helideck status light for placement on a helideck comprising at least one beacon light optic according to any one of claims 1 to 30.

35. A beacon light comprising at least one beacon light optic according to any one of claims 1 to 30 and at least one additional light optic, the additional light optic comprising an additional light source and the additional light optic being adapted to emit light having a different angular light distribution when compared to a light distribution emitted by said at least one beacon light optic.

36. A beacon optic comprising a plurality of beacon optics according to any one of claims 1 to 30, and wherein said plurality of beacon optics are positioned in a circular configuration with the exit surfaces facing outward such that light propagates through an azimuthal angle equal to or greater than 90°, preferably an azimuthal angle equal to or greater than 180°, more preferably an azimuthal angle of 360°.

37. A medium intensity obstacle light comprising at least one light beam optic according to any one of claims 1 to 30.

38. A helideck comprising a plurality of beacon lights and each of said beacon lights comprising at least one beacon light optic according to any one of claims 1 to 30.