Patent Application
20250175256
The present disclosure relates to the transmission and/or reception of signals via the medium of infrared, visible and/or ultraviolet light.
Light can be used to transmit signals such as digital data modulated into the light. The term “Light” herein may refer to infrared light, visible-spectrum light or ultraviolet light, or any combination of these. When transmitting light signals, then in order to save power, it is often desirable to use beamforming or beam-steering techniques to emit the light in the form of a directed beam, rather than broadcasting the light signals omnidirectionally. The transmit beam may be directed toward a specific remote device which is to receive the signal. Similarly, a light receiving apparatus may use receive beamforming or beam-steering techniques in order to form a solid angle relative to the receiver within which lights signals will be preferentially received (a receive beam). Note that a receive beam or receiving beam herein refers to a field of view (FoV) or field of sensitivity, not an incoming transmitted beam that is directed toward the receiving apparatus from a complementary remote device. The receive beam may be directed toward a specific remote device which is transmitting the signal. This will reduce the amount of background noise and/or interference relative to the desired signal to be received. In some cases beamforming or steering techniques may be used at both the transmit and receive side, such that a transmit beam and receive beam are aligned with one another. The incoming light beam should at least partially overlap with the FoV of the receive beam in order to be detectable.
An example application of communication via light is found in a luminaire, which can sometimes also be used as a data access point for the transmission and/or reception of data. For example the luminaire could be mounted on the ceiling in an office or such like. At one time, if it was desired to convey data in the light emitted by a luminaire, a code was embedded in the visible illumination emitted by the luminaire (so-called “coded light”), and the receiver would then use this code to look-up the required data via a separate radio channel (e.g. Wi-Fi). Nowadays however, an alternative is to integrate an infrared, visible light and/or ultraviolet transmitter and/or receiver into the luminaire, so as to communicate the desired data to and/or from the remote device directly embedded in the infrared light. An example of such a technology is sometimes referred to as “Li-Fi”.
US2021/0116655A1 (Grieco) discloses an optical system for beam steering. The system comprises a 2D array of emitter elements, each located at a fixed position behind a different respective part of a fixed diffractive lens system, where different parts of the lens system have different diffractive properties corresponding to different beam directions. See for example
Grieco thus discloses a purely optical system and teaches specifically to use no moving mechanical parts.
However, it is recognized herein that the 2D addressing circuitry required to selectively activate any of a 2D array of emitter elements is quite complex electronically speaking. It would be desirable to avoid this electronic complexity.
An alternative would be a mechanical approach whereby a lens is moved relative to a light emitting element (either by moving the lens or the emitter element), so that the relative position of the emitting element behind the lens determines the direction of the emitted beam. However, it is recognized herein that a 2D mechanical actuator to move the lens or emitter independently along two perpendicular axes would be very complex mechanically speaking.
The present disclosure provides a trade-off between electronic and mechanical complexity by providing an optical component and a series of two or more active emitting elements, whereby selective addressing of the emitter elements can be used to steer the beam in one dimension, whilst mechanical motion of the optical component can be used to steer the beam in another dimension. See for example
Similar considerations can equally apply to receive beam steering where the active elements are receiving elements rather than emitting elements.
According to one aspect disclosed herein, there is provided an apparatus comprising: an optical component comprising at least one or more first lenses; at least a series of first active elements, each of the first active elements being operable to receive light;
In embodiments the optical component comprises a lens array comprising a one-dimensional series of lenses and the active elements are arranged in a parallel one-dimensional series, where each emitter element is located behind a different one of the lenses and different emitter elements are positioned differently relative to their respective lenses along the axis of the array (e.g. the array of emitter elements has a slightly different pitch—i.e. spatial period—than the array of lenses).
To assist understanding of embodiments of the present disclosure and to show how such embodiments may be put into effect, reference is made, by way of example only, to the accompanying drawings in which:
The following describes a general beam steering system comprising a linear array of active electro-optical or opto-electrical elements, and an array of lenses (e.g. microlens array) whereby the position of the lens array can be adjusted relative to the active elements in a direction substantially perpendicular to the array of the active elements. Or an alternative is the complementary configuration, in which the lens array is adjustable in the direction of the array of active elements, and the various active elements have variation in their position in a direction perpendicular to the lens array (and the active elements array).
Embodiments also provide for control of the actuator so as to tune the direction of the beam based on a received signal.
In variants of the above, the actuator 2 may be arranged to move the series of active elements 8. Either way, the lens array 4 may be said to move relative to the active elements 8, whilst the positions the lenses 6 within the lens array remain fixed relative to one another, and the positions of the active elements 8 also remain fixed relative to one another.
The apparatus further comprises addressing circuitry 7 operatively coupled to each of the active elements 8, and a controller 9 operatively coupled to the actuator 2 and the addressing circuitry 7. The controller 9 may be implemented in the form of one or more processors and one or more memory units storing software arranged to run on the one or more processors, the software being configured so as when thus run to perform the operations of the controller 9. Alternatively the controller 9 may be implemented in the form of dedicated hardware circuitry, or in configurable or reconfigurable circuitry such as a PGA or FPGA, or any combination of hardware and software.
In
The series of lenses 6 in the lens array 4 is a linear series, i.e. the lenses 6 in the series are arranged along a one-dimensional axis. This could be a straight-line axis as illustrated, or a curved axis (e.g. an arc of a circle). Similarly the series of active elements 8 is a linear series, i.e. the active elements are arranged along a one-dimensional axis. Again this could be a straight-line axis as illustrated, or a curved axis (e.g. an arc of a circle). In such cases the axis or series may still be described as one dimensional in that the lenses 6 are constrained to being positioned along a single curve or line, and similarly for the active elements 8. The axis of the series of active elements 8 is substantially parallel to the axis of the series of lenses 6. So if the series of lenses 6 is arranged in a straight line, the series of active element 8 is also arranged in parallel straight line; or if the series of lenses 6 is arranged along a curve such as an arc, then the series of active elements 8 is arranged along a parallel arc or curve.
Each respective one of the active elements 8 is located behind a different respective one of the lenses 6 in the lens array 4. “Behind” in this context means that if the plane of the lens array divides the environment into two halves with the active elements 8 on one side and a remote device 14 with which the apparatus is to communicate on the other, then if the respective active element 8 is an emitter, it is arranged so as when activated to emit light through the respective lens 6 out onto the side of the remote device 14, or if the respective active element 8 is a receiver, it is arranged so as when active to receive light through its respective lens 6 from the side of the environment in which the remote device 14 is located. For instance if the apparatus is mounted on the ceiling to communicate with a remote device below the ceiling, then the active elements 8 would be above the lenses 6. The remote device 14 is not shown in
The spacing of the active elements 8 in the series is not exactly the same as the spacing of the lenses 6 in the lens array 4. Rather, each active element 8 is offset by a different amount relative to its respective lens 6 along the direction of the axis of the series of active elements 8 (which is parallel to the series of lenses 6). For instance, the series of lenses 6 may have a first pitch (i.e. spatial period) between lenses 6 along its axis, and the series of active elements 8 may have a second pitch (spatial period) between active elements 8 along its axis, wherein the second pitch is different than the first (but still close enough to keep each active element 8 behind a respective one of the lenses 6). In other words, each active element 8 has a different respective alignment relative to its respective lens 6 in the direction along the axis of the series.
The effect of this feature is that, because each active element has a different relative displacement relative to it respective lens 6, then when that element 8 is activated, it will form a beam in a respective direction dependent on the position of the element 8 relative to its respective lens 6. So different elements 8 will form beams in different directions. Thus by selecting which active element 8 to activate via the addressing circuitry 7, the controller 9 can select the direction of the beam being formed by the apparatus in a first dimension. The addressing circuitry may be controlled to activate only a single one of the active elements 8 at any one time, so as to form a single transmit or receive beam. Alternatively multiple selected elements 8 (but fewer than the entire series) could be activated at once in order to form multiple beams, or perhaps increase the width of the beam in the case of adjacent elements.
The addressing circuit 7 may be operable to select a subset of one or more of the active elements 8, so as to form or more beams. In embodiments the addressing circuit 7 may be operable to select to activate any individual one of the elements 8 at once, or any selected combination.
If the active elements 8 are light emitting elements, then the activated element will emit a beam of light (comprising a signal modulated into the light) in a selected direction defined by the position of the activated element 8 relative to its respective lens 6. Or if the elements 8 are receive elements, then the activated element will selectively or preferentially receive light signals from a particular direction (i.e. form a receive beam) defined by the position of the activated element 8 relative to its respective lens.
However, if the positions of the active elements 8 relative to their respective lenses 6 only differ along the 1D axis of the series of active elements 8 (and therefore also along the direction of the axis of the series of lenses which is parallel), then the selection of different active elements 8 via the addressing circuitry 7 will only vary the direction of the beam in a first dimension, e.g. which could be labelled the theta dimension in spherical polar coordinates (note that “dimension” or axis” in the present disclosure do not necessarily limit to a Cartesian coordinate system). Put another way, the section of active elements 8 steers the beam only in a first plane (e.g. a first vertical plane if the apparatus is facing down from the ceiling or up from a horizontal surface such as the floor or a desk or other worksurface).
In order to steer the beam in a second dimension, the actuator 2 is arranged to move the lens array 4 relative to the series of active elements 8, under control of the controller 9. The actuator 2 can move the relative position of the lens array 4 perpendicular to the axis of the series of active elements 8, and therefore can steer the beam in the second dimension. E.g. the second dimension could be labelled as the phi dimension in a coordinate system whereby theta and phi are angles in two orthogonal planes. In other words theta may be described as the angle between a first Cartesian axis and the projection of the direction vector of the beam onto the Cartesian plane coinciding with the first Cartesian axis, and phi may be described as the angle between a second Cartesian axis (orthogonal to the first) and the projection of the direction vector of the beam onto the Cartesian plane coinciding with the second Cartesian axis. In embodiments each of theta and phi can vary over a range up to pi steradian.
Thus, the movement of the actuator 2 steers the beam in a second plane perpendicular to the first plane (e.g. a second vertical plane if the apparatus is facing down from the ceiling or up from a horizontal surface such as the floor or a desk or other worksurface).
In the illustrated examples it is envisaged that series of lenes 6 is arranged along a straight line and the series of active elements 8 is arranged along a parallel straight line. In this case the actuator 2 is arranged to effect a translational (lateral) motion between the series of lenses 6 and the series of active elements 8. However this is not the only possibility. For example if both series are arranged along parallel arcs, then the actuator 2 may be arranged to move the lenses or elements 8 in the direction along the arced axis. E.g. the lenses 6 may be arranged tangentially along an arc of a circle, attached to a rotary actuator with its rotor at the focus of the arc.
Preferably, for reduced electrical and mechanical complexity, the addressing of different active elements 8 (via the addressing circuitry 7) can only steer the beam in the first dimension and not the second dimension, whilst the mechanical motion of the lens array 4 relative to the active elements (via the actuator 2) can only steer the beam in the second dimension and not the first dimension.
The motion of the lens array 4 by the actuator 2 is illustrated in
The actuator 2 is arranged such that when the controller 9 controls the actuator 2 to move the lens array 4 relative to the series of active elements 8, it changes the relative positions of the active elements 8 relative to the lenses 6 in a direction perpendicular to the axis of the series of active elements 8 (and therefore also perpendicular to the axis of the series of lenses 6 within the array 4, which is parallel to the series of active elements 8). Thus the motion by the actuator 2 steers the transmit or receive beam in the second dimension perpendicular to the first dimension.
The steering of the beam in the two perpendicular dimensions is illustrated in
In
The (or each) receiving beam has an angular acceptance Arx in the first dimension and Ary in the second dimension, both determined by the optical properties of the respective lens 6, as well as by the relative configuration of lens and sensor element and the actual dimensions of the sensor element. Again the lens 6 could be a collimating lens or a diverging lens. The apparatus as a whole has a scan range Rrx in the first dimension, this range being determined by the addressing of different active elements 8R (which may also be referred to as “pixels”) and their position along the axis of the series of lenses 6; and a scan range Rry in the second dimension, this range being determined by the lateral translation of the lens array 4 relative to the active elements 8R via the actuator 2.
Either way, each series of lenses 6i, 6ii has a respective series of active elements 8i, 8ii disposed behind them. I.e. the apparatus comprises a series of first active elements 8i and a series of second active elements 8ii. In the first series, each first active element 8i is disposed behind a different respective first lens 6i in the series of first lenses. In the second series of active elements 8ii, each second active element 8i is disposed behind a different respective second lens 6ii in the series of second lenses. Everything described above regarding the relative placement between active elements 8 and lenses 6 within a given series may apply mutatis mutandis with respect to each of i) the series of first active elements 8i and its respective series of first lenses 6i, and ii) the series of second active elements 8ii and its respective series of second lenses 6ii. I.e. within the series of first active elements 8i, each is disposed at a different respective position relative to its respective first lens 6i in the direction along the axis of the series of first active elements 8i; and within the series of second active elements 8ii, each is disposed at a different respective position relative to its respective second lens 6ii in the direction along the axis of the series of second active elements 8ii. In other words, the series of first active elements 8i has a first set of spacings (e.g. a first pitch) and the series of second active elements has a second set of spacings (e.g. a second pitch).
The first set of spacings may be the same as the second set of spacings, or different. The series of first active elements 8i and series of second active elements 8i may both be series of transmit elements 8T, both series of receive elements 8R, or one may be a series of transmit elements 8T and the other a series of receive elements 8R. The second series may have the same number of active elements 8ii as the first series, or a different number. The addressing circuitry 7 may be arranged so that each active element 8ii in the second series can only be activated at the same time as a counterpart 8i in the first series at the same relative position, or alternatively the active elements 8ii in the second series may be addressable independently of the active elements 8i in the first series.
The lenses 6i, 6ii of both series are both fixed relative to one another within the lens array 4, such that when the actuator 2 moves the lens array 4 relative to the underlying active elements 8, the lenses 6i, 6ii of both series move in unison with one another relative to the active elements 8.
In embodiments, the series of first active elements may be configured to receive data on a different wavelength channel than the second active elements. The channels may be on exclusive wavelengths or spectral bands, or overlapping spectral bands. Preferably the difference or separation in wavelength is suitable to enable wavelength-division multiplexing of the two channels. However this is not essential, as alternatively (or additionally), spatial multiplexing may be used by steering the beams in different directions, or indeed other forms of multiplexing could be used such as time division or code division.
In other embodiments, both emitter and receiver elements 8T, 8R that operate at different wavelengths may be placed behind different lenses 6 of a single series of lenses, or even with a respective transmitting and receiving element 8T, 8R behind the same series of lenses (whether having a respective transmitter-receiver pair 8T, 8R behind each lens 6 in the series, or just behind a particular one or subset of the lenses). Such embodiments would have an advantage that crosstalk (from emitter to receiver element) can be reduced, e.g. by applying a filter on the sensor element to shield it from the emission of the near-by emitter element.
There are a number of possible applications of an arrangement having two (or more) series of active elements 8i, 8ii as in
In one such arrangement, the series of second active elements 8ii has a different set of spacings than the series of first active elements 8i (i.e. a different pitch). I.e. the set of offsets of the second active elements 8ii relative to their respective second lenses 6ii is different than the set of offsets of the first active elements 8i relative to their respective first lenses 6i. Also, both the series of first active elements 8i and the series of second active elements 8ii are transmit elements 8T, or both receive elements 8R. Further, the active elements 8ii of the second series are addressable independently of those 8i of the first series. This means the series of second active elements 8ii and their corresponding second lenses 6ii can be used to create a different set of beam directions. Thus the two series of active elements 8i, 8ii can be used to extend the angular range or increase the directional granularity of the beam steering in the first dimension. Or, in the case where the series of second lenses 6ii is arranged alongside the series of first lenses 6i, as in
In another example application, the series of first active elements 8i is a series of transmit elements 8T, and the series of second active elements 8ii is a series of receive elements 8R. Thus the first and second series 8i, 8ii can be used to form a transmit and a receive channel respectively. An example of this is shown in
In some such embodiments, the two series may also have the same number of active elements 8 as one another, and the series of second active elements 8ii has the same set of spacings as the series of first active elements 8i (i.e. the set of offsets of the second active elements 8ii relative to their respective second lenses 6ii is the same as the set of offsets of the first active elements 8i relative to their respective first lenses 6i). Further, the addressing circuitry 7 may be arranged such that each respective second active element 8ii is always activated and deactivated along with a respective counterpart in the series of first active elements 8i (where the respective second active element 8ii has the same offset relative to its respective second lens 6ii, along the axis of the series, as the counterpart first active element 8i does with respect to its respective first lens 6i). This means that when an active element 8i of the first channel is selected in order to steer the first channel's beam in a certain direction in the first dimension, then the counterpart second active element 8ii of the second channel will also be selected in order to steer the second channel's beam in the same direction in the first dimension (since that element 8ii has the same relative displacement compared to its respective second lens 6ii, along the direction of the axis of the series, as does the corresponding first active element 8i relative to its respective first lens 6i). Thus the beams of the transmit and receive channels, or the two data channels, will always be steered together to point in the same direction (bearing in mind also that they are moved together in the second dimension by the actuator 2).
Alternatively it is not excluded that the elements 8ii of the second series could be addressable independently of the series of first active elements 8i, such that the beams of the two different channels can be steered independently in the first dimension (though they will still move together in the second dimension due to being part of the same physical lens array 4 and moved by the same actuator). For instance the actuator 2 could be used to steer the beams towards a certain row of remote devices 14 (e.g. each located at a different one of a regular bank of desks), and then the pixel addressing may be used to steer individual beams towards different remote devices 14 within the row.
As illustrated by way of example in
In either
In embodiments such as those of
Alternatively or additionally, the apparatus may comprise two (or more) parallel rows or lines of receive elements 8R, 8R′. The elements 8R, 8R′ in each row are still each behind at least one of the lenses 6ii. However, the different rows are located a different offsets in the direction perpendicular to the axis of the series of lenses 6, offset in the direction of (relative) motion of the lens array 4 by the actuator 2. Such an arrangement can be used to track the direction of the remote device 14 in the second dimension. In such embodiments, the controller 9 detects which of the receive elements 8R, 8R′ is currently receiving the strongest signal from the remote device 14—including in which row that element is found. Based on this, the controller 9 then controls the actuator 2 to move the lens array 4 relative to the active elements 8T, 8R, 8R′ and thus tune the direction of the transmit beam 10 in the second dimension so as to be directed toward the remote device 14.
In the illustrated embodiment of
Further variations and example implementations of schemes for tracking the remote device 14 will be discussed later with reference to
The amplifier, filter and beam selector module 16 is coupled to the receive elements 8R via the addressing circuitry 7 (not shown in
In operation, the beam steering management module 28 selects which receive element 8R to use to receive a signal from the remote device 14. In response the amplifier, filter and beam selector module 16 uses its beam selection function to activate the selected element 8R via the addressing circuitry 7. The amplifier, filter and beam selector module 16 then uses its filtering and amplifier capability to filter and amplify the signal received at the selected receive element 8R, and pass the resulting signal to the demodulator 18. The demodulator 18 demodulates this to produce a demodulated received signal 20.
The beam steering management module 28 selects which transmit element 8T to use to send a signal to the remote device 14. In embodiments this may be done based on which receive element 8R is selected to best receive from the remote device 14, as discussed earlier. Either way, in response, the driver 26 selects to activate the selected transmit element 8T via the addressing circuitry 7. The modulator 24 modulates the desired signal 22 to be transmitted, and passes it to the driver 26 to transmit via the selected transmit element 8T.
While the above has been described in terms of embodiments where the motion effected by the actuator 2 is perpendicular to the axis of the series of lenses 6 in the lens array 4, this is not limiting. In alternative embodiments the motion may instead be parallel to the axis of the series of lenses 6 (or to the axes of parallel lens series), whilst different active elements 8 may be arranged at different positions behind a given lens 6 in a direction perpendicular to the axis of the lens series. Thus pixel addressing by the addressing circuitry 7 would steer the beam in a plane perpendicular to the axis of the lens series, whilst the actuator 2 would steer the beam in a plane parallel to the axis of the lens series.
In a further variant, only a single movable lens 6 may be used, with a series of two or more active elements 8 behind the lens 6. In this case the actuator 2 would cause relative motion of the lens 6 in one direction, while the series of active elements would be aligned along another, perpendicular direction. An example of this is shown in
Alternatively or additionally, in yet further variants the relative motion between lens(es) 6 and active elements 8 need not be absolutely perpendicular to the series of active elements. More generally, the relative motion between lens(es) and active elements 8 may merely be non-parallel to the series of active elements (the motion having at least a perpendicular component compared to the axis of the series of active elements 8). For example one could have a configuration of a linear array of active elements and a collinear array of lenses, but with their axis not perpendicular to the actuator movement (but, e.g. with an inclination of 45°). This also works just as the orthogonal cases, as long as the offset of the active elements relative to the lens elements is in a direction perpendicular to the actuator to make both beam steering directions independent from each other.
Or in yet another variant, the series of lenses 6 may be parallel to the direction of movement, and the active elements 8 may also be placed almost parallel along the direction of movement (e.g. one active element 8 behind each lens 6), provided that that the offset of the active elements relative to the lenses is not parallel to the direction of movement. An example of this is shown schematically in
The following now describes in more detail some example implementation details for implementing the techniques disclosed herein.
Embodiments provide a 2D steerable optical beam emission and/or detection configuration for LiFi communication. The system comprises a linear array of electro-optic or opto-electric elements (the “active” elements that can be light sources and/or photo detectors) and a linear microlens array, where the pitch in the array of the active elements and in the array of the microlenses are different. Furthermore, the microlens array is moveable by means of an actuator, preferably an electromechanical (e.g. piezoelectric or bimorph) or electromagnetic actuator. Thanks to the different pitch of the lens elements and the active elements, these combinations of the various active elements and the corresponding lens elements result in different direction of optical beam emission or reception. Therefore, scanning in one direction is possible by means of pixel addressing of the active element array. The lens array is moveable in a direction substantially perpendicular to the direction in which the beam is pixel-addressed steerable. By moving the position of the lens elements relative to the active elements, the direction of emission/reception is steered in a plane coinciding with the axis of the mechanical translation. Therefore, the mechanical translation corresponds with beam steering in a direction substantially orthogonal to that of the pixel-addressed steerability. By combining the lens array translation with pixel-addressing of the active elements array, 2D directional steering of an emitted optical beam or of a received optical beam is realized. In embodiments, the combination of both provides an ideal way to set identical selection of the incoming and emitting directional beams. In embodiments the steering may comprise systematically scanning across two dimensions, e.g. to search for an incoming beam 12.
In LiFi systems, electromagnetic radiation in the visible or near infrared (NIR) part of the spectrum is high-frequency modulated to transmit data at a high data rates. In earlier commercial systems, for the downstream link data flows from one or several electro-optical emitters comprised in an access point (AP) in the ceiling (e.g. integrated in a luminaire) via a wide beam of modulated radiation to a receiver at the location of an end-user or end point (EP). This receiver is typically a dongle that is connected via a USB interface with a computer. For the upstream link, an electro-optical emitter located in the dongle emits a wide beam of modulated radiation that in turn is received by one or more opto-electrical sensors in the access point in the ceiling. Most light detectors are based on a photodiode provided with an optical element to concentrate the light. The optical beams are generally very wide and detection under larger angles becomes increasingly difficult due to strongly reduced optical power detection with increasing angles. It would be desirable to reduce the power consumption, to increase the coverage area, to reduce interference and/or to increase the end user density, i.e., the number of connections between APs and EPs.
Increase of the EP density without compromising the link speed per EP would require an increase in power consumption and in emitted optical power in the current LiFi systems. Both are undesirable, both from a sustainability and competitive point of view as well as from an eye safety point of view. In addition, the current systems do already consume too much power and need a significant power reduction to enable large-scale adoption. A solution for these issues is the use of directional beams. Flexibility requires that such directional beams can be scanned across a range of directions. In addition, a directionally sensitive detection system would be desirable to determine in which direction a directional beam is to be emitted. Beam steering using a 2D scanning mirror is known. However, the scanning range is very limited. Also source segmentation is known, enabling addressing of various beam segments. However, for multiple segments and a compact configuration of the source pixels, as required for miniaturized components, addressing the pixels in a 2D arrangement is difficult without applying a complex stack of active elements on top of a CMOS chip for vertical addressing.
The present disclosure describes a system that delivers a directional beam with 2D directional steering and scanning capability, as well as a system that provides directionally sensitive detection of incoming optical beams, enabling low-power operation of such LiFi systems, while enabling easy access to the various active elements. In addition, embodiments provide for setting the identical direction for both the incoming and the outgoing optical beams.
2D step-wise scanning of the direction of an optical beam, either emitted from an electro-optical element such as a vertical cavity surface emitting laser (VCSEL) or received by an opto-electrical sensor element such as an avalanche photodiode (APD), may be realized by selectively addressing of one or more active elements out of a 2D array of multiple of such active elements. However, addressing of the elements in a dense 2D array is problematic. Alternatively, a single active element may be used by combining this with a 2D scanning mechanism that changes the relative position of the element and a beam shaper such as a lens. However, miniaturization and functionality of such 2D scanning mechanism is problematic.
The present disclosure provided a configuration in which a linear array of active electro-optical or opto-electrical elements, of which the individual elements can easily be addressed, is combined with a microlens array that can be linearly translated by an actuator in a direction substantially perpendicular to the array. The pitch of the active elements differs from that of the microlens array. As a result, by selectively addressing of one or more elements of the linear array of active elements, the associated optical beam can be step-wise steered in a direction determined by the arrays. By translating the microlens array by means of an actuator, such as a piezoelectric actuator, the optical beams associated with the active elements can be steered in the direction determined by the mechanical translation of the microlens array. Combining the selection of one or more of the active elements with selecting a certain translation position of the microlens array results in selection of a specific beam direction in a 2D angular phase space and enables active steering of one or more optical beams. This beam is either an emitted optical beam, in case of an array of electro-optical active elements, or an optical beam that is detected, in case of an array of opto-electrical active elements.
This principle is schematically depicted in
This beam steering may be used for one or more emitting beams, for one or more receiving beams, or for a combination of one or more emitting and receiving beams. In the latter case the two systems as described above are combined, either each with their own actuator or using a single actuator.
The disclosed configuration of active elements 8 and lens array elements 6 enables the 2D quasi-continuous steering of an emitted light beam or angular-specific detection of an incoming light beam.
The active elements 8 in the linear array may be electro-optic elements such as light emitting diodes (LEDs), super luminescent emitting diodes (SLEDs), vertical cavity surface emitting lasers (VCSELs), photonic crystal surface emitting lasers (PCSELs), or edge-emitting laser diodes (EELDs). A lens array 4 is mounted movably collinear with and above the active elements array.
Using a different pitch for the elements 8 in the active elements array and for the lenses 6 in the lens array 4, the light beams associated with the various active elements with their related lenses vary in direction in a plane coinciding with the axis of the arrays. Selected activation of an electro-optic (or opto-electric) element 8 means, therefore, that one can step-wise steer the beam in one direction.
For steering the beam in a direction perpendicular to that, i.e. perpendicular to the arrays, the lens array 4 is translated by an actuator 2, as indicated in
For electro-optic elements, positive lenses may be used to both shape and direct the beam emitted from the system, where the focal distance and the actual distance from emitter to lens determine the final beam divergence. This is shown schematically in
As the beams from adjacent emitter elements are preferred to partly overlap with each other, the beams are designed with the required divergence, related to the steps in angular resolution of this step-wise steerable beam.
In alternative embodiments, other configurations and implementations of active element and lens combinations, and of lens elements, may be used, for example as follows.
Other possible embodiments include:
For receiver elements, the objective is to achieve angularly resolved sensitivity 13 and to improve speed as well as signal-to-noise ratio (SNR) by condensing received light on small opto-electric receiver elements 8R. Suitable elements 8R may be phototransistors (PT's), PiN photodiodes (PDs), avalanche photodiodes (APDs), photomultipliers (PM's), etc. The concept is very similar to what has been described above for an emitted beam, but in this case for an incoming light beam that is to be detected, a certain fraction of it is actually received by a sensor element 8R. This is determined by the effective light receiving surface area, the direction of the incoming beam, the size of the sensor element and the relative position of the lens 6 and the active sensor element 8R. By design, a certain angular extent of the sensitivity of each sensor element and lens combination 8R, 6 is realized such that these “sensitivity cones” 13 show a certain degree of overlap for adjacent sensor and lens combinations. In the direction perpendicular to the arrays, the beam steering (or scanning) may again be continuous thanks to the possibility to steer the actuator 2 continuously. This angular resolved beam reception 13 as described above is depicted schematically in
In the embodiments of
Based on the disclosed emitter and sensor systems, it is also possible to provide an optical radiation sensing and emitting unit that combines these features, e.g. that emits a beam of modulated optical radiation with a solid angle subtended of less than 60%, preferably less than 30%, most preferably less than 20%, of the viewing solid angle of the sensor system in a direction that is determined directly from the detected optical powers by (groups of) sensor elements 8R. This may be realized by combining a sensing unit and an emitting unit as described above, or these systems can be further integrated by using only a single actuator 2 for the lenses that steer the emitted beams and for the lenses that determine the directional sensitivity of the sensor element—lens combination as well. This integrated scenario may be implemented for example as schematically depicted in
This may be used to provide a receiver-emitter system for LiFi with linear sensor and emitter pixel arrays and translatable microlens arrays for the emitter and for the sensor pixel arrays. As discussed previously, the different active elements 8 have different relative component positions for a given actuator status, while orthogonal position variations are achieved upon variation of actuator settings. The direction of emission is based on the selected emitter pixel(s) and actuator setting (i.e. position of the lens array), while the directional sensitivity of the receiver is set by the selected sensor pixel and the same actuator setting.
In further embodiments, lenses 6 in receiver-emitter systems may be used for both multiple emitter elements 8T and for multiple sensor elements 8R. This is particularly attractive if the active elements 8 can be placed closely together. An example of five active elements 8 under three lenses 6 is shown in
An alternative embodiment is depicted in
Considerations in this design are an optimisation of using the receiving area as optimally as possible. Therefor the photodetector (PD) elements 8R are as densely as possible packed along the center line on which the detector lenses 6ii are aligned. Electronics for read out, such as Transimpedance Amplifiers (TIAs) can be located next to the detectors, this very nearby to avoid parasitic effects in the wiring, and allow as dense as possible the packing of the photo sensitive areas. At each location, two PDs 8R, 8R′ are placed next to each other, such that these show a different sensitivity to light coming from slightly different angles of incidence in the dimension in which the mechanical actuator 2 can steer the beam, and, therefore, can steer the sensitivity. Hence, a control signal can be derived by comparing the strength of the signal in each PD of such a pair. If the light falls predominantly on the PD that is closest to the actuator 2, the unit may be moved further out such that relatively more light falls on the outer PD. The controller 9 is preferably is configured to ensure that an equal amount of light falls on the inner and outer PD 8R, 8R′. This may be done for a specific subset of the PD pairs or for by combining the signals of all inner and all outer PDs and subtracting the joint inner from the joint outer signal.
In the particular example shown, five pairs of PDs (8Ra, 8Ra′; 8Rc, 8Rc′; 8Rf, 8Rf′; 8Ri, 8Ri′; 8Rk, 8Rk′) detect light respectively coming from extreme left, moderate right, centre, moderate left and extreme right. This would be for positive (condensing) lenses as illustrated in the drawings. For negative (diverging) lenses the order would be the opposite. Thereby these sensor pairs see light that corresponds to the direction in which the emitters 8T can respond in a bidirectional link. Although the system can be used for a single user, up to five parallel channels could be used if counter stations happen to be in different sectors and aligned along a direction such that all received signals are optimum for the same position of the lens array actuator. In addition, signals captured by other pairs of PDs (8Rb, 8Rb′; 8Re, 8Re′; 8Rg, 8Rg′; 8Rj, 8Rj′), can be added to further contribute to particular receiver sectors and can be added to the signal from the first-mentioned five pairs of PDs (8Ra, 8Ra′; 8Rc, 8Rc′; 8Rf, 8Rf′; 8Ri, 8Ri′; 8Rk, 8Rk′). Alternatively or additionally, elements 8Rd, 8Rd′; 8Rh, 8Rh′ may be added to correspond with the largest angles of incidence, not covered by the other elements 8Ra, 8Ra′; 8Rc, 8Rc′; 8Rf, 8Rf′; 8Ri, 8Ri′; 8Rk, 8Rk′. As these are positioned at the interface between two lenses 6, and if there is no optical block between the lens-sensor segments, then elements 8Rd, 8Rd′; 8Rh, 8Rh′ can only be used to determine the absolute angle of incidence, but not whether that comes from the left or from the right. If there are no emitting elements 8T positioned such that they can emit a beam in this direction, then these sensor elements may just be used to have a somewhat larger overall field of view (field of regard) than the overall field of emission of transmitting elements 8T, or to activate the emitters that would point most closely to that direction. For the determination whether the beam comes from left or right, signals from other (neighbouring) sensor elements would be required as well.
In further embodiments, emitters and detectors may share the same lens. An example of such an embodiment is schematically indicated in
For most incoming angles, two detectors 8R may capture the signal, thereby making more effective use of the total optical opening (which is the union of all lenses 6 and their motion area). In this special case, two emitters 8T cover the reception area in the form of having two sectors, while the detectors 8R receive signals from three sectors but with large overlap. Such overlap has two benefits: (I) a direction can be determined from the relative strength of the signals in the sectors and (II) if the signal arrives in more than one sector, these sectors can be combined to enhance the signal-to-noise ratio, or, in other words, to increase the effective aperture via which the receiver sees incoming photons. The received signal consists of the addition of the signal seen in the centre detector and the signal in one of the two side detectors. The signal strength in the left detector minus the signal strength of the right detector can be used as a control signal that determines which detector to add, but also for which emitter to use to communicate with the counter station 14.
For a wireless communication system, or module, with the optical beam emitting and receiving units as described above, the various sensor element outputs are preferably amplified and filtered to facilitate selection of elements corresponding with a direction of incidence that is to be selected and to further process the selected signal, i.e., to demodulate the signal for further downstream processing. Preferably, for detection of active elements 8R that are receiving signal, low pass filtering is applied, with the filter edge at e.g. 1 MHz, to enable high sensitivity, which typically is combined with high pass filtering at some lower frequency to eliminate background signals, while for the further amplification and demodulation of a selected signal high pass filtering may be applied with the filter edge at e.g. 1 MHz. As the selected direction of the sensor sensitivity is determined by both the selection of the sensor element(s) 8R and the actual position of the lens array 4, i.e., the actuator status, beam steering management 28 may be employed to coordinate the selection and setting of to be received and to be emitted optical beams. This beam steering management 28 communicates with both the receiving signal electronics 16 and the driver 26. The driver 26 receives the modulated signal that is to be emitted and provides the drive current(s) to the selected emitter element(s) 8T as well as the actuator signal to set the lens array 4 in the right position. Such a system is schematically depicted in
The figure shows schematically the receiving unit, that comprises the sensor element array 8R with the actuator 2 and the lens array 4 for the receiving beams as described above, and the by the receiving unit accepted parts of two different incident beams A and B. The received signals RS1 to RSn of the sensor array, which may correspond with n or an integer multiple of n sensor elements 8R, are amplified and filtered, and a selection of to be further processed signals is made before that signal is demodulated for downstream processing. Beam steering management 28 determines what settings are to be used for the actuator 2, that is fed with an actuator signal AS. In case of discrete receiving and emitting units this signal is sent to the two corresponding actuators 2, or two separate signals are used to achieve the correct corresponding lens positions. In case the receiving and emitting units are further integrated there may be only a single actuator 2. The driver 26 further can provide the modulated drive currents comprising the emitter signals to a subset of one or more of the emitter elements, ES1 to ESn. The beam steering management 28 determines which emitter elements are to be addressed, i.e., to which emitter elements 8T modulated drive signals are sent. This results in emission of a beam that is substantially in the same direction as from where the incident beam has been received. The figure shows these emitted beams A′ and B′ that correspond with the detected incoming beams A and B.
The systems are preferably configured such that the beams corresponding with two adjacent beam directions show a certain degree of overlap to prevent dead zones or signal loss when switching from one beam direction to the other.
In alternative embodiments, an additional directionally sensitive optical sensor, such as a quadrant detector with appropriate optics, may be used to determine the direction of incidence of an incoming optical beam. In that case there is an additional input to the beam steering management 28. The frequency response of this detector is preferably chosen far lower than for the signal detection, enabling highly sensitive directional detection. Preferably the f3 dB, i.e., the modulation frequency at which the sensor response falls by 3 dB, of this directional sensor is less than 10% of that of the signal sensor.
In embodiments, the system may scan for presence of an optical signal incident from a certain direction. Once detected, the angular direction of the position of the emitting point 14 is known and a narrow beam can be emitted towards that point. The narrower this beam, the less energy is required, but also more accurate directional sensing and pointing of the emitted beam will be needed. Typically, the emitted beam width is comparable or larger than that of the received (accepted) incoming beams to prevent that the targeted node 14 is missed, as generally it may not be known where exactly that node is other than that it's somewhere in the received angular beam width. The angular step from one beam direction to the next one, in case of variation of the relative positions/directions of the two LINK nodes, needs to be smaller than the width of the beam to ensure continuous connection. The overlap is preferably at least ca 10%. With a quad detector, the angular space can be split into four segments or more (depending on the accuracy of the detector), and the solid angle subtended by the emitted beam of the end node can be less than 30% of the sensor's FoV. Preferably the sensor's accuracy in determining the angular relative position of the AP is such that the solid angle subtended can be less than 10% of the FoV, meaning that for identical data speed the optical power requested for the emitted beam is reduced by a factor of ten. In this case the uplink beam overlaps only with the targeted node 14, and interference effects are therefore reduced.
The following now describes in more detail some example implementations of detector-servo configurations.
To detect the received signal and be able to generate the servo signals to aim the beam in the right direction, several detector layouts can be imagined. In the following figures the rectangular areas labelled A, B, etc. or A1, A2, etc. indicate the active photon detection surfaces 8R; and the dots indicate the spots of light falling on the detector surface as created by the lens array 4. The left/right arrows indicate the direction of receiver or source selection by addressing circuitry 7. The up/down arrows indicate the direction of lens movement. In these pictures a linear lens array is assumed, however it could also be extended to a square or hexagonal or any other array. From the detector configuration there are three signals that may be derived, as follows.
1. The direction of the incoming light in the receiver/source selection plane. (used to switch on the right light source for the return signal. This may be referred to herein as Sselect.
2. A servo signal to be able to position the lens array actuator. This may be referred to herein as Slens-act.
3. The high frequency modulated data signal. This may be referred to herein as Srf.
By determining which detector pair receives the biggest signal, the direction where to retransmit can be derived. This can be expressed as:
where n indicates the number of detector pairs. This signal Sselect indicates from which direction the received signal is coming in the selection direction. This can also be used to select the detector pair to derive the high frequency data signal from. In case the spot is in between two detectors, the signals from these two detectors can beneficially be summed to increase the signal to noise ratio. In the perpendicular direction the servo signal Slens-act that is used to actuate the lens array can be derived from:
where A1-n=A1+A2+A3+A4 . . . An and B1-n=B1+B2+B3 . . . Bn. When Slens-act is negative (B bigger than A), the lens array (and thereby the spots) should move upward in the picture (
A drawback of the configuration of
This further improved detector configuration can use the same servo signals as described above.
An alternative detector configuration that removes the dead areas in the detector array while limiting the number of segments and split lines can be found in
The normalized servo signal determining the receiving direction can be derived from:
The normalized servo signal for the direction of the lens array movement can be derived from:
The data signal can be derived by summing all segments together:
Note that the required band width for the various signals may be different. The data signal may require large bandwidths even up to 100 Ghz, while the servo signals may be limited to frequencies below 1 MHz or even less. As the bandwidth of a detector becomes smaller for larger detector areas, it is beneficial to limit the size of the segments used for data retrieval. For the lens movement servo signals, one would like to use larger segments to enlarge the capture range of this servo.
The signals from A′+B′ and C′+D′ can be slow as these are only used to capture the spots and move these towards the center segments (A, B, C, D)
This signal can be used to drive the spots towards the center segments. Once in range of the center segments, one can switch to the Slens-act signal for fine-tuning of the lens array position:
Alternatively, a combined servo signal can be used:
The data signals can still be derived from the A, B, C, D central segments keeping the detector size small.
In other embodiments, further segmentations and permutations of configurations are possible in line with the principles described above.
It will be appreciated that the above embodiments have been described by way of example only.
More generally, according to one aspect disclosed herein, there is provided apparatus comprising: an optical component comprising at least one or more first lenses; at least a series of first active elements, each of the first active elements being operable to receive light; an actuator arranged to effect a relative movement between the optical component and the series of first active elements in a first direction; and addressing circuitry operable to selectively activate a selected subset of one or more of the first active elements, from among a plurality of possible subsets, to receive light. Each of the first active elements is disposed behind a respective one of the first lenses so as when activated to receive light through the respective lens. Further, different ones of the first active elements are arranged at different positions relative to their respective lens in a second direction non-parallel to the first direction, and thus by selecting which of the first active elements to activate using the addressing circuitry, a first transmitting or receiving beam can be controlled to be formed at a selected angle in a first dimension as determined by the position of the activated element relative to its respective lens. By operating the actuator to effect a relative motion between the optical component and the series of first active elements in the second direction, the first transmitting or receiving beam can be controlled to be formed at a selected angle in a second dimension non-parallel to the first dimension.
According to another aspect, there is provided an apparatus comprising: a lens array comprising at least a series of first lenses arranged along an axis of the series of first lenses; at least a series of first active elements arranged along an axis of the series of first active elements parallel to the axis of the series of first lenses, each of the first active elements being operable to receive light; an actuator arranged to effect a relative movement between the lens array and the series of first active elements in a direction perpendicular to the axis of the series of first lenses; and addressing circuitry operable to selectively activate a selected subset of one or more of the first active elements, from among a plurality of possible subsets, to receive light; wherein each of the first active elements is disposed behind a respective one of the first lenses so as when activated to receive light through the respective lens; different ones of the first active elements are arranged at different positions relative to their respective lenses along the axis of the series of first active elements, and thus by selecting which of the first active elements to activate using the addressing circuitry, a first transmitting or receiving beam can be controlled to be formed at a selected angle in a second dimension as determined by the position of the activated element relative to its respective lens; and by operating the actuator to effect a relative motion between the lens array and the series of first active elements in the direction perpendicular to the axis of the series of first lenses, the first transmitting or receiving beam can be controlled to be formed at a selected angle in a first dimension perpendicular to the second dimension.
In embodiments the second direction is perpendicular to the first direction, and the second dimension is perpendicular to the first dimension.
Preferably the optical component is a lens array, the one or more first lenses being a series of first lenses arranged along an axis of the series of first lenses.
Note that moving the optical component or lens array relative to a series of active elements may be implemented by moving the lens array or moving the series of active elements.
Preferably the actuator cannot, by the relative motion it effects, steer the beam in the first dimension. Preferably the addressing circuit cannot select to steer the beam in the second dimension.
In embodiments, the optical component is a lens array, the one or more first lenses being a series of first lenses arranged along an axis of the series of first lenses; and the series of first active elements is arranged along an axis of the series of first active elements parallel to the axis of the series of first lenses. In such embodiments, the first direction, in which the relative motion is effected, may be non-parallel to the axis of the series of first lenses. Further, at least some of the first active elements are disposed behind different respective ones of the first lenses than others of the first active elements, and different ones of the first active elements are arranged at different positions relative to their respective lenses along the axis of the series of first active elements. The operating of the actuator comprises operating the actuator to effect a relative motion between the lens array and the series of first active elements in the first direction non-parallel to the axis of the series of first lenses.
In embodiments the first direction is perpendicular to the axis of the series of first lenses.
The series of first lenses may be a regular series having a first regular spacing between the first lenses along the axis of that series. The series of first active elements may be a regular series having a second regular spacing between the first active elements along the parallel axis. In this case the first regular spacing has a first spatial period (first pitch) and the second regular spacing has a second spatial period (second pitch) that is different than the first spatial period.
The first active elements may all be behind their own different respective ones of the first lenses. Or alternatively some of the first active elements could be behind the same first lens as one another and some could be behind different first lenses.
In some embodiments, the first active elements may be divided into a plurality of different subsets, at least one of the subsets comprising more than one of the first active elements, wherein within each subset the first active elements are disposed behind the same respective one of the first lenses, and different subsets are disposed behind different ones of the first lenses.
For example, the lens array may also comprises a series of second lenses arranged along an axis of the second series of lenses parallel to the axis of the series of first lenses; and the apparatus may further comprise a series of second active elements. In such embodiments, the addressing circuitry may be operable to selectively activate different ones of the second active elements to emit or receive light; and each of the second active elements may be disposed behind a respective one of the second lenses so as when activated to emit or receive light through the respective lens, with at least some of the second active elements being disposed behind different respective ones of the second lenses than others of the second active elements. Further, different ones of the second active elements may be arranged at different positions relative to their respective lenses along an axis of the second series of active-elements parallel to the axes of the first and second series of lenses, such that by selecting which of the second active elements to activate using the addressing circuitry, a second transmitting or receiving beam can be controlled to be formed at a selected angle in said second dimension. Further, being part of the same lens array, a relative motion between the series of second lenses and the series of second active elements is effected in unison with the relative motion between the series of first lenses and the series of first active elements, such that an angle of the second transmitting or receiving beam in said first dimension is also controlled along with the first transmitting or receiving beam when operating the actuator.
The series of first and second lenses may be formed from the same piece of glass, plastic or other such optical medium.
In embodiments the first and second active elements may be all emitting elements or all receiving elements.
Alternatively the first active elements may be emitting elements and the second active elements may be receiving elements, the first beam being a transmitting beam and the second beam being a receiving beam.
Either way, the series of first active elements may be configured to receive a first wavelength or spectral band of light and the series of second active elements are configured to emit or receive a second wavelength or spectral band of light different than the first wavelength or spectral band. E.g. the first active elements may receive on a first spectral band and the second active elements may emit or receive on a second spectral band, wherein the wavebands may be exclusive or may overlap.
In embodiments the first and second active elements may be all emitting elements or all receiving elements, and the positions of at least some of the second active elements relative to their respective lenses may be different than in the series of first lenses. This arrangement may be employed such that the series of second active elements extends an angular range over which the transmit or receive beam can be controlled to be formed in the first dimension.
Alternatively the positions of the first active elements relative to their respective first lenses within the series of first active elements may be the same as the positions of the second active elements relative to their respective second lenses within the series of second lenses. Thus the transmit and receive beams, or the different wavelength beams, can be produced at the same angle as one another.
In further alternative arrangements, the first direction may be parallel to the series of first lenses, such that the motion effected by the actuator is parallel to the series of first lenses, and different ones of the series of first active elements are disposed at different positions perpendicular or at least non-parallel to the axis of the series of first active elements.
In embodiments, the apparatus comprises a controller arranged to control the addressing circuitry to perform the selecting of the subset of active elements and the operating of the actuator by providing selection information to the addressing circuitry.
In embodiments, the controller may be configured to: detect receipt of a signal from a remote device at two or more of the receiving elements at different positions along the axis of the series of receiving elements; compare a signal strength of the received signal as received at each of the two or more receiving elements, and based thereon determine an orientation of the remote device relative to said apparatus in the second dimension; and based on the determined orientation in the second dimension, control the addressing circuitry to select one of the emitting elements to orient the transmitting beam toward the remote device in the second dimension.
In embodiments, in addition to the series of receiving elements, the apparatus may further comprise one or more offset receiving elements offset perpendicular to the axis of the series of receiving elements in the direction of motion of the lens array. In such embodiments the controller may be configured to: detect receipt of a signal from a remote device at at least one of the receiving elements in the series of receiving elements, and at at least one of the one or more offset receiving elements; compare a signal strength of the received signal as received at i) the at least one receiving element in the series with ii) the at least one offset receive element, and based thereon determine an orientation of the remote device relative to said apparatus in the first dimension; and based on the determined orientation in the first dimension, operate the actuator to orient the transmitting beam toward the remote device in the first dimension.
In some such embodiments, the apparatus may comprise a respective offset receiving element for each of the receiving elements in the series, each located behind the same respective lens at its respective receiving element in the series, at the same position along the axis of the series of receiving elements. In embodiments the comparison of signal strength may be between at least one of the receiving elements in the series and its respective offset receiving element.
In embodiments, the light which the first and/or second active elements are operable to emit or receive may comprise infrared light.
In embodiments the apparatus may be incorporated in a luminaire.
According to another aspect disclosed herein, there is provided a method of employing an optical component comprising at least one or more first lenses, and at least a series of first active elements, each of the first active elements being operable to receive light. The method comprises: using an actuator arranged to effect a relative movement between the optical component and the series of first active elements in a first direction; and using addressing circuitry to selectively activate a selected subset of one or more of the first active elements, from among a plurality of possible subsets, to receive light. Each of the first active elements is disposed behind a respective one of the first lenses so as when activated to receive light through the respective lens. Further, different ones of the first active elements are arranged at different positions relative to their respective lens in a second direction non-parallel to the first direction, and thus by selecting which of the first active elements to activate using the addressing circuitry, a first transmitting or receiving beam can be controlled to be formed at a selected angle in a second dimension as determined by the position of the activated element relative to its respective lens. And by operating the actuator to effect a relative motion between the optical component and the series of first active elements in the first direction, the first transmitting or receiving beam is controlled to be formed at a selected angle in a first dimension non-parallel to the second dimension.
In embodiments, the method may further comprise steps in accordance with the use of any of the apparatus features disclosed herein.
According to another aspect disclosed herein, there may be provided a computer program embodied on computer-readable storage and configured so as when run on one or more processors to perform any of the disclosed methods.
In embodiments, the program may be configured to perform further operations in accordance with the operation of any of the apparatus features disclosed herein.
Other variants or use cases of the disclosed techniques may become apparent to the person skilled in the art once given the disclosure herein. The scope of the disclosure is not limited by the described embodiments but only by the accompanying claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 22151710.5 | Jan 2022 | EP | regional |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2023/050530 | 1/11/2023 | WO |
