GB2544779A

GB2544779A - Actuator assembly for vehicle lighting system

Info

Publication number: GB2544779A
Application number: GB1520888.7A
Authority: GB
Inventors: Bourqui Yvan
Original assignee: Johnson Electric SA
Current assignee: Johnson Electric SA
Priority date: 2015-11-26
Filing date: 2015-11-26
Publication date: 2017-05-31
Also published as: GB201520888D0

Abstract

An actuator assembly 10 is provided for a vehicle headlight which comprises: an assembly support 16; a flexible reflector 20 associated with the assembly support 16, the flexible reflector 20 having a reflective surface which is arranged to reflect light emitted from the vehicle headlight; and at least one actuator 18 connected to the reflector 20 so as to enable flexion of at least part of the reflector 20, an orientation of the reflector 20 determining a direction of the reflected light from the actuator assembly 10. A vehicle headlight system, a motor vehicle capable of controlling the direction of headlight emission, and a method of improving the precision of the direction of light emitted from the headlights of a motor vehicle are also provided.

Description

Actuator Assembly for Vehicle Lighting System

The present invention relates to an actuator assembly for a vehicle lighting system, in particular for the headlights of the vehicle. A vehicle headlight system, a motor vehicle capable of controlling the direction of headlight emission, and a method of improving the precision of the direction of light emitted from the headlights of a motor vehicle are also provided.

In order to direct the light emitted from the headlights of a motor vehicle in order to compensate for vehicular pitch, for example, it has become common to utilise actuator assemblies inbuilt to the vehicular lighting assemblies, which are able to manipulate a position of the lighting elements of the vehicle, so as to change a direction of the emitted light therefrom.

The majority of vehicles currently have manually operable adjustment mechanisms for their headlights, for example, to provide dipped beams. However, in prestige or luxury motor vehicles, actuator assemblies have been used which typically comprise at least one actuator which is coupled to an actuatable element which will determine the direction of the light emitted therefrom. The actuatable element is hinged in two axes to permit it to be actuated sufficiently so as to compensate for three-dimensional vehicle pitch which would otherwise affect the direction of the light.

Unfortunately, such hinged arrangements are complicated to manufacture, due to the requirement to provide smooth moving components, and are also prone to failure. In particular, vibrations arising from engine activity and/or normal shock absorption from the vehicular suspension system can result in imprecision in the positioning of the actuatable element to arise.

As laser light-emitting diodes become more cost-effective, there is a growing inclination to integrate these components into vehicular headlight systems, since the light quality and power consumption compares favourably with existing halogen bulb solutions. Unfortunately, laser-based lighting solutions require very precise control of the direction of light emission, since there is a greater risk of distracting glare for other motorists from laser light than the less directional light emitted from halogen bulbs.

The present invention seeks to provide solutions to provide a stable and precise actuator for vehicle headlights which would be compatible for use with laser light-emitting diodes, so as to overcome or obviate the above-mentioned problems.

According to a first aspect of the invention, there is provided an actuator assembly for a vehicle headlight, the actuator assembly comprising: an assembly support; a reflector associated with the assembly support, the reflector having a reflective surface which is arranged to reflect light emitted from the vehicle headlight and being at least in part flexible; and at least one actuator connected to the reflector so as to enable flexion of at least part of the reflector, an orientation of the reflector determining a direction of the reflected light from the actuator assembly.

By permitting flexion of the reflector so as to accommodate the force applied by the actuators, it becomes possible for precise actuations of the reflective portion of the reflector to be achieved without resorting to complicated mechanisms which may include many small interengagable components. This reduces the manufacturing complexity of the reflector in particular, which in turn can lead to reliability improvements, as the actuator assembly is less prone to failure, for example, due to the seizing of co-operating parts.

Preferably, the reflector may comprise a mirrored portion acting as the reflective surface and an at least in part flexible linkage engagable with the assembly support. Such a flexible linkage of the reflector may be formed from a flexible metal. Furthermore, the mirrored portion and the flexible linkage of the reflector may be unitarily formed with one another. Optionally, a width of the mirrored portion of the reflector may be greater than that of the flexible linkage.

By providing a reflector having a primary mirrored portion and a flexible linkage, it becomes possible for the mirrored portion to retain or substantially retain its shape and form during the actuation, ensuring precise control over the movements of the reflective surface, with all flexion being provided for by the flexible linkage. This has the effect of improving the accuracy of light reflected from the actuator assembly.

Preferably, the flexible linkage may be formed as an elongate strip, capable of flexion along a longitudinal extent of the strip, and furthermore the flexible linkage may be capable of twisting flexion about the longitudinal extent of the strip.

The primary advantage of a strip-like flexible linkage is that it is not only capable of bending or folding over on itself, but is also capable of twisting about a longitudinal axis. This ensures that reorientation of the position of the reflector can be achieved in three dimensional space.

In a preferred embodiment, the or each actuator may include at least one piezoelectric element and/or a mechanical stroke amplifier.

Piezoelectric actuators are capable of very small and precise actuations, and therefore may not necessarily be compatible with standard mechanical actuator arrangements having discrete positions defined by the relative positioning of individual components, such as toothed gears. The flexion of the reflector in the present arrangement permits the use of these highly accurate actuators in the vehicle headlight systems.

First and second said actuators may be provided to enable relative motion of the reflector in first and second different axes.

Multi-dimensional actuation of the reflector allows for it to be positioned for changes in the pitch of the motor vehicle to which it is installed in three dimensions; this includes compensation for what might be termed the pitch, yaw and roll of the vehicle.

Preferably, a position sensor may be provided which is engagable with the reflector to determine a position thereof. There then may further comprise a feedback circuit in communication with the position sensor to enable adjustment of the reflector following vibrational or positional displacement of the reflector. The reflector may include a universal joint engagable with the position sensor to permit measurement of a position of the reflector. Alternatively, the reflector may further comprise a secondary flexible linkage engagable with the position sensor to permit measurement of a position of the reflector.

Sensing the position of the reflector ensures that a controller of the actuator assembly can adjust the actuators if necessary to correctly compensate for vehicular pitch. In particular, this may be necessary if the actuator assembly has been incorrectly calibrated in the first instance. The position sensor and feedback circuit allows for correction in inconsistencies in the eventual alignment of the reflector.

In one embodiment, the assembly support may include a mechanical actuator to enable additional non-flexible actuation of the reflector, which may further comprise a motorised unit arranged to drive the mechanical actuator. Additionally or alternatively, the assembly support may include a buttress portion to limit flexion of the reflector in at least one direction.

Flexion of the reflector is useful for small precise actuations; however, large actuations may be better served using traditional mechanical actuation means. By providing a secondary actuator, larger movements can be provided for than can be accommodated purely using flexion. This may be necessary, for instance, to permit large horizontal movements for the actuator assembly.

According to a second aspect of the invention, there is provided a vehicle headlight system comprising: at least one lighting element; and an actuator assembly, preferably in accordance with the first aspect of the invention; wherein the lighting element is configured to emit light towards the reflector of the actuator assembly, the orientation of the reflector determining a direction of the reflected light.

Preferably, the or each lighting element may include a laser light-emitting diode.

Laser light-emitting diodes have improved quality of emitted light, but require highly accurate reflector arrays in order to direct the highly directional coherent light emitted. This has previously held back the uptake of laser lighting solutions in motor vehicles; however, the present vibration resistant actuator assemblies are capable of overcoming this issue.

According to a third aspect of the invention, there is provided a motor vehicle capable of controlling the direction of headlight emission, the motor vehicle comprising: a wheeled chassis; at least one vehicle headlight system, preferably in accordance with the second aspect of the invention; and a controller in communication with the actuator assembly of the vehicle headlight assembly to control a direction of reflected light emitted from the or each vehicle headlight assembly relative to the wheeled chassis. A motor vehicle having the vehicle headlight system as described ensures that, whilst driving the vehicle, the road ahead is correctly illuminated, rather than causing glare for other road users, or illuminating a portion of the road which is too close to the vehicle itself to be safe.

According to a fourth aspect of the invention method of improving the precision of the direction of light emitted from the headlights of a motor vehicle, the method comprising the steps of: a] providing an actuator assembly, preferably in accordance with the first aspect of the invention, having an actuatable reflector which is at least in part flexible; b] engaging an actuator of the actuator assembly to flex the reflector into a desired orientation; and c] directing light from a lighting element of a vehicle headlamp towards the reflector, such that the light is reflected in a desired direction.

Flexion of a reflector as part of an actuator assembly ensures that small precise adjustments to the position of the reflector can be achieved without utilising complicated moving components, which could otherwise result in reduced reliability of the actuator assembly.

The invention will now be more particularly described, by way of example only, with reference to the accompanying drawings, in which:

Figure 1 shows a perspective representation of one embodiment of a vehicular lighting system, incorporating a first embodiment of an actuator assembly in accordance with the first aspect of the invention;

Figure 2 shows a perspective representation of a second embodiment of a reflector usable as part of an actuator assembly in accordance with the first aspect of the invention;

Figure 3 shows a perspective representation of a third embodiment of a reflector usable as part of an actuator assembly in accordance with the first aspect of the invention;

Figure 4a shows a front perspective representation of a fourth embodiment of an actuator assembly in accordance with the first aspect of the invention;

Figure 4b shows a side view of the actuator assembly as shown in Figure 4a;

Figure 4c shows a plan view of the actuator assembly as shown in Figure 4a; and

Figure 5 shows a front perspective representation of a fifth embodiment of an actuator assembly in accordance with the first aspect of the invention.

Referring firstly to Figure 1, there is illustrated a vehicular lighting system, indicated globally at 10, and which utilises a lighting element 12 and an actuator assembly 14 capable of directing the light emitted from the lighting element 12 in a direction of choice.

The lighting element 12 is, in this case, formed as a laser light-emitting diode, capable of emitting a directional, coherent laser beam, indicated by dashed line L. Whilst the present invention has been designed with laser light-emitting diode technology in mind, it will of course be appreciated that the present arrangement may be utilised in conjunction with any reasonably well-focussed and/or directed light source.

The actuator assembly 14 comprises an actuator support 16 to which is mounted at least one actuator 18 and a reflector 20 having a reflective surface which is capable of reflecting the light emitted from the lighting element 12.

The reflector 20 is preferably formed as a unitary piece of thin metal which is at least in part flexible, such as thin aluminium sheet, for example. However, the reflector 20 could be formed as a multi-part piece, and any suitably reflective material or coating could be used as a mirrored portion 22 of the reflector. The present reflector 20 is formed having a rectangular or substantially rectangular mirrored portion 22, preferably having a planar surface, and having an elongate flexible linkage 24 extending from one edge 26 of the mirrored portion 22. At a distal end 28 of the flexible linkage 24, there may be provided a support engagement portion 30, here formed as a rectangular area which is affixed to a base portion 32 of the assembly support 16, for instance, via riveting.

The mirrored portion 22 is preferably wider than the flexible linkage 24, which provides the mirrored portion 22 with a greater structural rigidity than the flexible linkage 24, ensuring that when an external force is applied to the reflector 20 the flexible linkage 24 flexes in preference to the mirrored portion 22. However, the mirrored portion 22 could feasibly be additionally rigidified if necessary.

The assembly support 16 in the illustrated embodiment has the base portion 32 as previously mentioned, which is formed from a, preferably solid, block of preferably non-reflective material. At one end of the base portion 32 is provided a support back 34 which is a rigid structure positioned at or substantially at right angles to the base portion 32. The exact form of the assembly support 16 is designed to provide sufficient structural support to the reflector 20, and therefore the illustrated embodiment is merely exemplary of the many possible assembly supports 16 which may be appropriate for a motor vehicle.

The reflector 20 is affixed to a front edge 36 of the base portion 32 of the assembly support 16 which is spaced from the support back 34. This can be achieved, as indicated, by fixing the support engagement portion 30 to the base portion 32.

In the present embodiment, two actuators 18 are optionally provided, since this allows for actuation of the reflector 20 in first and second different axes, typically orthogonal to one another. However, a single actuator could be provided, if motion in only one direction was required, or if a multi-directional composite actuator were provided. Similarly, a greater number of actuators could be provided, as required.

The actuators 18 are preferably provided as piezo-actuators, having a stack of piezoelectric elements 38 arranged in connection with a mechanical stroke amplifier 40, formed as a diamond-shaped structure which can be expanded or contracted in an axis of the stack of piezoelectric elements 38. Although a substantially diamond shaped polygonal structure is suggested, it is envisaged that any suitable circular or non-circular shaped resiliently flexible structure may be considered.

The actuators 18 are positioned intermediate a front surface 42 of the support back 34 and a rear surface 44 of the mirrored portion 22 of the reflector 20, the stroke amplifier 40 being connected at horizontal ends to each of the front surface 42 of the support back 34 and rear surface 44 of the mirrored portion 22. The opposite front surface 46 of the mirrored portion 22 therefore presents the reflective surface from which light from the lighting element 12 can be reflected, and is therefore highly polished, coated with a highly reflective coating, or similarly treated to improve the reflectively thereof.

The front surface 46 of the mirrored portion 22 acts as the surface of reflectance, and changing an orientation of this front surface 46, and indeed the mirrored portion 22 as a whole, changes the direction of light emitted from the front surface 46.

To operate the actuator assembly 14, a controller can be provided, either manually or automatically operable, which is in communication with the actuators 18. Once a reflected light direction has been chosen, the controller can command the actuators 18 to actuate the reflector 20 into the correct orientation. This ideally does not alter the plane of the front surface 46 of the mirrored portion 22.

As at least one actuator 18 is activated, a force is applied to the rear surface 44 of the mirrored portion 22. This causes the flexible linkage 24 to flex, being the most readily flexible part of the reflector 20.

The flexible linkage 24 is able to flex in and out of a default plane as defined by the front surface 46 of the mirrored portion 22 in the absence of any external force. This can be achieved by flexion of the flexible linkage 24 along a longitudinal extent thereof, which would result in a tilting of the mirrored portion 22 towards or away from the support back 34. Additionally or alternatively, the flexible linkage 24 may be formed so as to be sufficiently flexible so as to be able to twist about an axis coaxial with the longitudinal extent, effectively rotating the mirrored portion 22 about a vertical axis.

The provision of piezoelectric elements 38 as the means by which the actuators 18 are driven ensures that a precise motion of the mirrored portion 22 can be readily achieved.

This enables the actuations to be controlled to a sufficient accuracy so as to be usable in conjunction with laser light-emitting diodes.

The permissible flexion in the reflector 20, which is accommodated by the flexible linkage 24 in the depicted embodiment, allows for the actuator assembly 14 to be constructed without relying on any complicated hinged arrangements; all of the necessary motion of the mirrored portion 22 can be provided for within the single flexible linkage 24. In this way, even though the mirrored portion 22 can be moved in two different axes, that is, having both vertical and horizontal adjustability, only one point of articulation is required. This simplifies the manufacturing complexity of the actuator assembly 14 as a whole, which in turn improves the cost-effectiveness and reliability. A second embodiment of a reflector 120 for a vehicle lighting system 110 is illustrated in Figure 2. Identical or similar components to those described in respect of the first embodiment of the invention have identical or similar reference numerals to those utilised above, and further detailed description will be omitted for brevity.

In this particular embodiment, a positional sensor 148 is provided which is coupled to a secondary flexible linkage 150 of the reflector 120. The secondary flexible linkage 150 is provided which projects in a direction from the mirrored portion 122 of the reflector 120 which is opposite to the direction of the primary flexible linkage 124.

As the reflector 120 is actuated so as to alter the alignment of the mirrored portion 122, the secondary flexible linkage 150 also moves relative to the positional sensor 148. This may be achieved literally via physical dislocation of the secondary flexible linkage 150 on a surface 152 of the positional sensor 148. The change in the transmission can be fed back to a controller for the vehicle lighting system 110, to ensure that the actuation ordered by the controller has been correctly achieved, allowing for any discrepancies to be compensated for. A third embodiment of a reflector 220 for a vehicle lighting system 210 is illustrated in Figure 3. As before, identical or similar components to those described in respect of the first embodiment of the invention utilise identical or similar reference numerals, and further detailed description will be omitted for brevity.

Here, the flexible linkage 224, which is connected to the mirrored portion 222 of the reflector 220, is engaged with a ball joint 254, and at a lowermost end 228 of the flexible linkage 224 is provided a sensor magnet 256. A sensing circuit 248 associated with the sensor magnet 256 is able to determine a relative orientation or position of the reflector 220 based on a magnetic field disturbance resulting from the relative movement of the ball joint 254 as the flexible linkage 224 flexes under an actuation force. Again, the sensing circuit 248 may be in communication with a controller of the vehicle lighting system 210 to enable feedback control of the reflector 220 position. A fourth embodiment of an actuator assembly 314 for a vehicle lighting system 310 is illustrated in Figures 4a to 4c. As before, identical or similar components to those described in respect of the previous embodiments of the invention utilise identical or similar reference numerals, and further detailed description will be omitted for brevity.

Whilst the flexible linkage 324 is useful for providing small, precise movements under an actuation force, often relatively large angular actuation is required in a horizontal direction. Typically, large horizontal adjustment is useful for providing a so-called curve light functionality. In such a scenario, it is desirable that the illumination provided by headlights on the road surface follows a curvature of the road, so as to illuminate the direction in which the vehicle is going, rather than the instant trajectory of the vehicle. Alternatively, the angular adjustment of headlights could be useful when transferring from a right-hand-drive road system to a left-hand-drive road system can be relatively large, covering an angle of up to +/-20 degrees. On the other hand, the vertical adjustment requires a much smaller range of movement, typically no more than 4 degrees.

In the depicted embodiment, the base support 332 of the assembly support 316 includes a rotatable plinth 358 which is powerable via a motorised unit 360 to provide rotation about a vertical axis. This can therefore effect a change in the horizontal alignment of reflector 320, by rotation relative to a structural support, such as the base plate 362 as indicated. In this embodiment therefore, only a single actuator 318 is provided, here connected to an upper portion of the rear surface 344 of the mirrored portion 322 of the reflector 320.

Furthermore, the support back 334 of the assembly support 316 is provided so as to provide a buttress portion 364 at or adjacent to the flexible linkage 324 of the reflector 320, thus providing a resilience to flexion about a vertical axis, since this motion is now provided for by the rotatable plinth 358.

Figure 5 shows a fifth embodiment of an actuator assembly 414 for a vehicle lighting system 410, which is substantially similar to that of the fourth embodiment. As before, identical or similar components to those described in respect of the previous embodiments of the invention utilise identical or similar reference numerals, and further detailed description will be omitted for brevity.

In this embodiment, the base support 432 is structured so as to be more slimline than that of the fourth embodiment; no structural support is shown, for clarity. The motorised unit 460 is provided so as to be behind the support back 434 of the assembly support 416, with a rotatable portion 458 of the base support 432 having a shaped, contoured or reduced-dimension profile. The reduction in the amount of material to construct the base support 432 advantageously reduce the manufacturing cost of the vehicle lighting system 410; only the wedge shape of the rotatable portion 458 of the base support 432 is necessary to achieve the range of movement required for the reflector 420 in a horizontal axis. This reduction in the material required is of particular use where a piezo edge motor is used as the motorised unit 460, since the contact surface which contacts with a tip of the piezo edge motor is formed from a relatively expensive ceramic material. By utilising an actuator assembly 414 which is designed so as to only be actuatable in the required range, typically +/-20 degrees of a circle, a rotatable portion 458 having an angular shaping to match this requirement can be produced so as to minimise material wastage, and thus improve cost-effectiveness.

Whilst a rotatable plinth or portion 358, 458 is described in the fourth and fifth embodiments above, it will be appreciated that any standard electromechanical actuation could be provided to allow for the greater range of motion which might be required in certain directions, and the skilled person will be aware of standard means by which this actuation can be achieved.

Whilst the actuator assembly is illustrated as being provided as an isolated unit, it is of course possible that a complete vehicle lighting assembly could be provided, wherein the actuator assembly and lighting element were provided within a single housing which could be readily installed into a motor vehicle. This would advantageously simplify the installation of such a system.

The mirrored portion of the reflector is hereto described as being a planar reflective surface. It will be appreciated however that other optical elements could be provided as part of the reflector. For example, the mirrored portion could be provided having a concave or convex surface, or could include lensing capability to focus or diffuse the light reflected therefrom. The form of the mirrored portion is illustrated for indicative purposes only.

It is therefore possible to provide an actuator assembly for a vehicle headlight system which relies on a flexible linkage to be able to reposition the reflector thereof, thus enabling small precise actuations to be achieved without requiring complicated mechanisms. This can be readily achieved by providing a piezoelectric actuator in connection with the reflector of the actuator assembly. Such an arrangement is of particular use with laser light-emitting diode headlight systems, in which the precision of the reflector positioning is critical to ensure correct illumination of the road surface ahead of a motor vehicle to which the vehicle headlight system is installed.

The words ‘comprises/comprising’ and the words ‘having/including’ when used herein with reference to the present invention are used to specify the presence of stated features, integers, steps or components, but do not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof.

It is appreciated that certain features of the invention, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable sub-combination.

The embodiments described above are provided by way of examples only, and various other modifications will be apparent to persons skilled in the field without departing from the scope of the invention as defined herein.

Claims

1. An actuator assembly for a vehicle headlight, the actuator assembly comprising: an assembly support; a reflector associated with the assembly support, the reflector having a reflective surface which is arranged to reflect light emitted from the vehicle headlight and being at least in part flexible; and at least one actuator connected to the reflector so as to enable flexion of at least part of the reflector, an orientation of the reflector determining a direction of the reflected light from the actuator assembly.

2. An actuator assembly as claimed in claim 1, wherein the reflector comprises a mirrored portion acting as the reflective surface and an at least in part flexible linkage engagable with the assembly support.

3. An actuator assembly as claimed in claim 2, wherein the flexible linkage of the reflector is formed from a flexible metal.

4. An actuator assembly as claimed in claim 2 or claim 3, wherein the mirrored portion and the flexible linkage of the reflector are unitarily formed with one another.

5. An actuator assembly as claimed in any one of claims 2 to 4, wherein a width of the mirrored portion of the reflector is greater than that of the flexible linkage.

6. An actuator assembly as claimed in any one of claims 2 to 5, wherein the flexible linkage is formed as an elongate strip, capable of flexion along a longitudinal extent of the strip.

7. An actuator assembly as claimed in claim 6, wherein the flexible linkage is capable of twisting flexion about the longitudinal extent of the strip.

8. An actuator assembly as claimed in any one of the preceding claims, wherein the or each actuator includes at least one piezoelectric element.

9. An actuator assembly as claimed in any one of the preceding claims, wherein the or each actuator includes a mechanical stroke amplifier.

10. An actuator assembly as claimed in any one of the preceding claims, wherein first and second said actuators are provided to enable relative motion of the reflector in first and second different axes.

11. An actuator assembly as claimed in any one of the preceding claims, further comprising a position sensor engagable with the reflector to determine a position thereof.

12. An actuator assembly as claimed in claim 11, further comprising a feedback circuit in communication with the position sensor to enable adjustment of the reflector following vibrational or positional displacement of the reflector.

13. An actuator assembly as claimed in claim 11 or claim 12, wherein the reflector includes a universal joint engagable with the position sensor to permit measurement of a position of the reflector.

14. An actuator assembly as claimed in claim 11 or claim 12, wherein the reflector further comprises a secondary flexible linkage engagable with the position sensor to permit measurement of a position of the reflector.

15. An actuator assembly as claimed in any one of the preceding claims, wherein the assembly support includes a mechanical actuator to enable additional non-flexible actuation of the reflector.

16. An actuator assembly as claimed in claim 15, further comprising a motorised unit arranged to drive the mechanical actuator.

17. An actuator assembly as claimed in claim 15 or claim 16, wherein the assembly support includes a buttress portion to limit flexion of the reflector in at least one direction.

18. A vehicle headlight system comprising: at least one lighting element; and an actuator assembly as claimed in any one of the preceding claims; wherein the lighting element is configured to emit light towards the reflector of the actuator assembly, the orientation of the reflector determining a direction of the reflected light.

19. A vehicle headlight system as claimed in claim 18, wherein the or each lighting element includes a laser light-emitting diode.

20. A vehicle headlight system substantially as hereinbefore described, with reference to Figure 1, Figure 2, Figure 3, Figures 4a to 4c, or Figure 5 of the accompanying drawings.

21. A motor vehicle capable of controlling the direction of headlight emission, the motor vehicle comprising: a wheeled chassis; at least one vehicle headlight system as claimed in any one of claims 18 to 20; and a controller in communication with the actuator assembly of the vehicle headlight assembly to control a direction of reflected light emitted from the or each vehicle headlight assembly relative to the wheeled chassis.

22. A method of improving the precision of the direction of light emitted from the headlights of a motor vehicle, the method comprising the steps of: a] providing an actuator assembly having an actuatable reflector which is at least in part flexible; b] engaging an actuator of the actuator assembly to flex the reflector into a desired orientation; and c] directing light from a lighting element of a vehicle headlamp towards the reflector, such that the light is reflected in a desired direction.

23. A method as claimed in claim 22, wherein the said actuator assembly is an actuator assembly as claimed in any one of claims 1 to 17.