WO2010010490A1

WO2010010490A1 - Lighting system for selective illumination

Info

Publication number: WO2010010490A1
Application number: PCT/IB2009/053085
Authority: WO
Inventors: Stefan M. Verbrugh; Mark J. A. Verhoeven; Lars R. C. Waumans
Original assignee: Koninklijke Philips Electronics NV
Current assignee: Koninklijke Philips NV
Priority date: 2008-07-22
Filing date: 2009-07-16
Publication date: 2010-01-28
Anticipated expiration: 2011-01-22
Also published as: TW201013103A

Abstract

A lighting system (1, 21, 31) for selective illumination in an irradiation plane (10), which lighting system (1, 21, 31) comprises a lighting fixture (2, 32) and at least two lighting units (3) tiltably mounted to the fixture (2, 32) and each arranged to emit a beam of light towards the irradiation plane (10) at a variable tilt angle in relation to a normal (N) of the lighting fixture (2, 32), wherein each of the units (3) comprises a light source and an adjustment portion (5). The lighting system (1) further comprises a first angle adjustment means (6, 26, 36) having predefined formations (8, 28), wherein the predefined formations (8, 28) are adapted to, in use, couple with the adjustment portion (5) of each of the units (3) for tilting each of the units (3) about at least one axis to respective first predefined position, such that beams of light emitted by each of the units (3) are provided at respective first predefined tilt angles (?). With the provision of a lighting system (1) in accordance with the present invention, the characteristics of light spots (9) formed by light beams emitted by the lighting units (3) in the irradiation plane (10), such as the number of light spots (9) and the amount of flux distributed to each light spot (9), may be varied.

Description

Lighting system for selective illumination

FIELD OF THE INVENTION

The present invention relates to a lighting system for selective illumination in an irradiation plane, which lighting system comprises a lighting fixture and at least two lighting units tiltably mounted to the fixture, each unit arranged to emit a beam of light towards the irradiation plane.

DESCRIPTION OF THE RELATED ART

In order to for instance intensify an impression, spot light effects are commonly utilized to illuminate certain objects in a display window, a shop, a museum, a theatre etc. For the illumination, an array of conventional bulbs which provides a high flux output may be effective. A lighting system comprising such lamps however unavoidably has a considerable size. For instance, for a flux of the order of 500 Im the lamps are of diameters close to 50 mm, and for a flux above 2000 Im the lamp diameters approaches 100 mm.

Naturally there is a strive for less space consuming lighting systems, and to this end it has been commonly known to instead of lamps utilize light emitting diodes

(LEDs). With a plurality of LEDs replacing a lamp, the same flux may be accomplished with a lighting system size considerably decreased. This is especially true for lighting systems comprising LEDs arranged in a linear manner, i.e. with LEDs placed along a line, since such a line due to the smaller sizes of the LEDs may be much narrower. In addition, in a linear LED arrangement the transfer of heat is better facilitated, so the heat sink can be a lot smaller. In tilting the LEDs to emit light beams to common light spots, the same effect as accomplished with lamps may be achieved. Furthermore, with a lighting system comprising a plurality of LEDs different illumination possibilities are provided.

US 7,004,603 for instance describes an angle adjustment device suitable for use in automated lighting, comprising a support member and a plurality of holders for LEDs, which holders each are supported by the support member for pivoting about at least one axis. The device further comprises an elongate spiral element which co-operates with the holders so that when the spiral element is displaced angularly about its axis relative to the support member, each holder pivots about its said at least one axis. However, although the described device consequently enables changing the angle and shape of the beam of light emitted by LEDs, the flexibility with regards to the number of light spots formed by the emitted light beams, as well as the ability to vary the amount of flux provided to each light spot, is rather limited.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide a lighting system in which the above-related drawbacks are at least partly eliminated.

According to the invention, the above object is met by a lighting system for selective illumination in an irradiation plane, which lighting system comprises a lighting fixture and at least two lighting units tiltably mounted to the fixture and each arranged to emit a beam of light towards the irradiation plane at a variable tilt angle in relation to a normal of the lighting fixture, wherein each of the units comprises a light source and an adjustment portion. The lighting system further comprises a first angle adjustment means having predefined formations, wherein the predefined formations are adapted to, in use, couple with the adjustment portion of each of the units for tilting each of the units about at least one axis to respective first predefined position, such that beams of light emitted by each of the units are provided at respective first predefined tilt angles.

By using a lighting system according to the present invention, light beams emitted from one and the same set of lighting units may form a different number of light spots in the irradiation plane depending on if a first angle adjustment means is utilized during use of the lighting system. Furthermore, since the total amount of flux, i.e. light beams, provided from the set of lighting units is fixed regardless of if the angle adjustment means is used, the distribution of the flux to the different light spots is consequently dependent on the predefined tilt angles of emitted light beams, and subsequently, on the predefined formations of the angle adjustment means affecting the respective lighting units to tilt to predefined positions. Consequently, with the introduction of a lighting system according to the present invention, the characteristics of light spots formed by light beams emitted by the lighting units may be varied. The characteristics may for instance include the number of light spots and the amount of flux distributed to each light spot.

Thereby, the lighting system is capable of supporting applications for instance having varying requirements over a time period of the characteristics of the formed light spots. In other words, the lighting system may at one point in time provide for instance a small number of light spots each to which respective large flux is distributed, and at another point in time provide a larger number of light spots each to which a respective smaller flux is distributed. Alternatively, the same number of light spots may be maintained at that other point of time, with the flux of the respective light spots distributed in a different manner.

Preferably, the lighting system further comprises a second angle adjustment means having predefined formations, wherein the predefined formations are adapted to, in use, couple with the adjustment portion of each of the units for tilting each of the units about at least the one axis to respective second predefined position, such that beams of light emitted by each of the units are provided at respective second predefined tilt angles. The second angle adjustment means may thus instead of the first angle adjustment means be selected to couple with the lighting units. With the provision of a second angle adjustment means, the lighting system provides even further improved possibilities to vary the characteristics of light spots formed by light beams emitted by the lighting units. That is, with the additional angle adjustment means, more options with regards to combinations of predefined tilt angles may be supported in that the formations of the second angle adjustment means differs from the formations of the first angle adjustment means.

In order to provide space efficient lighting units within the lighting system, light sources of the lighting units preferably comprise light emitting diodes (LEDs). By utilizing LEDs instead of for instance conventional lamps, due to the LEDs being much smaller, the same flux may be accomplished within the lighting system with a lighting system size considerably decreased.

Furthermore, the lighting units, given there are at least three, are preferably arranged in a linear formation. With a linear formation, the transfer of heat is better facilitated, whereby the heat sink can be a lot smaller. Additionally, according to another embodiment, the lighting units may further be arranged in a matrix formation. In order to allow the lighting units to tilt about at least one axis, and preferably about two, the lighting units may each be mounted to the fixture by a respective universal joint. By utilizing universal joints, the angle adjustment means may thus tilt the units to their predefined positions in an efficient and flexible manner.

The formations of the angle adjustment means need to have shapes adapted to tilt the lighting units to their respective predefined positions. An efficient manner to provide these shapes is to leave out parts of the angle adjustment means, such that the boundaries of the remaining part of the angle adjustment means couples with the lighting units. Accordingly, the formations of the angle adjustment means may comprise cut out holes in a solid body. Furthermore, the adjustment portion of at least one of the lighting units may comprise a rod extending from the unit, which rod is adapted to cooperate with the angle adjustment means. With the adjustment portions being represented by rods, the lighting units may easily, in use, due to the convenient shape of the rods be coupled with the adjustment means in a simple manner.

According to one embodiment, the first and second angle adjustment means preferably each has the form of a frame stretching along the lighting units, the first and second means being arranged in parallel to each other in a direction of the stretch, and the lighting fixture being arranged in between the irradiation plane and the first and second means. Thereby, an efficient way of arranging the angle adjustment means in relation to each another and the other parts of the lighting system is presented. By selecting one of the angle adjustment means and move it downwards towards the lighting fixture, that specific angle adjustment means may thus couple with the lighting units, to tilt them to their respective predefined positions.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other aspects of the present invention will now be described in more detail, with reference to the appended drawings showing currently preferred embodiments of the invention, in which: Figs. Ia and Ib illustrate an exemplifying lighting system in accordance with a first embodiment of the present invention.

Figs. 2a and 2b illustrate an exemplifying lighting system in accordance with a second embodiment of the present invention.

Fig. 3 illustrates an exemplifying lighting system in accordance with a third embodiment of the present invention.

DETAILED DESCRIPTION OF CURRENTLY PREFERRED EMBODIMENTS

The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which currently preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided for thoroughness and completeness, and fully convey the scope of the invention to the skilled addressee. Like reference characters refer to like elements throughout. Fig. Ia illustrates an exemplifying lighting system 1 according to a first embodiment of the present invention. The lighting system 1 comprises a lighting fixture 2, onto which several lighting units 3 are mounted. Although the lighting fixture 2 in the illustrated embodiment is straight in a lengthwise direction, and the lighting units 3 are arranged in a linear formation, the present invention is not restricted thereto. The lighting fixture 2 may have other forms and the lighting units 3 may be arranged in other formations, as for instance will be shown in Fig. 3 later on. It should also be emphasized that a "linear" formation should be interpreted in a broad sense, for instance likewise including formations slightly bent or having the form of an "S". The number of lighting units 3 provided in the lighting system 1, e.g. six, is merely exemplary, and any number of lighting units 3 more than one is feasible. Each lighting units 3 comprises a light source for emission of light beams towards an irradiation plane 10, and although LEDs are provided as light sources along with suitable optics (e.g. collimator) in this embodiment, other light sources may likewise be utilized. In order for the lighting units 3 to each have a defined default disposition in relation to the lighting fixture 2, each lighting units 3 may have a weight distribution such that the end of the lighting unit 3 emitting light beams is heavier than the opposite end. Alternatively (not shown), springs may be attached to each lighting unit 3 which may bring the lighting unit 3 to its default disposition. The lighting units 3 are in the illustration mounted to the lighting fixture 2 by universal joints 4 allowing each respective lighting unit 3 to tilt, i.e. pivot, about at least one of its axis around the joint 4. In the embodiment of Fig. Ia, the lighting units 3 are arranged to tilt only in a direction essentially parallel to the lengthwise direction of the lighting fixture 2. However, it is likewise feasible for each lighting units 3 to be tiltable about a second axis around the joint 4, e.g. in a direction perpendicular to the lengthwise direction of the lighting fixture 2. Furthermore, although universal joints 4 are utilized in the shown embodiment, other means for mounting the lighting units 3 to the lighting fixture 2 are likewise feasible, such as for instance hinges, flexible joints, etc. For the embodiment of Fig. 1, as tilting of lighting units 3 only is desirable about one axis, hinges may even be a preferable choice. Furthermore, each joint 4 is preferably adapted to allow the corresponding lighting unit 3 to in a default position, due to gravity or assisted by springs, point downwards.

Each lighting unit 3 comprises an adjustment portion 5; here in the form of a rod extending from respective lighting unit 3 in a direction which may be essentially perpendicular to the lengthwise direction of the lighting fixture 2. The adjustment portion 5 of a lighting unit 3 does not necessarily need to be positioned as shown in Fig. Ia; the portion 5 may likewise be provided anywhere feasible on the lighting unit 3, such as for instance closer to the end of the lighting unit 3 emitting light beams, and/or positioned on the other side of the lighting unit 3 in relation to the universal joint 4. Furthermore, although a rod is the choice of adjustment portion 5 in Fig. Ia, other forms are likewise feasible, such as for instance a hook, or even a recess in the lighting unit 3. According to another example, the adjustment portion 5 may comprise a magnet of a shape and position suitable for a corresponding implementation.

The lighting system 1 furthermore comprises a first angle adjustment means 6 and a second angle adjustment means 7; here in the form of frames stretching in parallel along the lengthwise direction of the lighting fixture 2, i.e. along the lighting units 3. It should be emphasized that "parallel" should be interpreted in a broad sense, for instance likewise including frames 6, 7 slightly diverging from each other.

The frames 6, 7 may be solid, or semi-solid, preferably of metal or plastic material, with predefined formations 8. Other materials may of course be feasible. In the shown embodiment, the formations 8 are represented by cut-out holes. Furthermore, in the shown embodiment there are two angle adjustment means 6, 7 illustrated. However, any number of angle adjustment means 6, 7 is feasible, and may be chosen based on the implementation in mind; one is applicable as well as for instance ten. The frames 6, 7 are positioned such that the lighting fixtures 2, and subsequently the rods 5, are positioned between the frames 6, 7 and the irradiation plane 10. Should other adjustment portions 5 than rods and/or other shapes of the angle adjustment means 6, 7 be desirable, the positioning of the adjustment portions 5 and the angle adjustment means 6, 7 may naturally be different in relation to each other. The predefined formations 8 of a frame 6, 7 are in the illustration arranged along the frame 6, 7 at positions corresponding to the positions of the lighting units 3 along the lighting fixture 2. As there are six lighting units 3 in the shown embodiment, there is for instance six formations provided in each frame 6, 7. Alternatively, and depending on the application in mind, a formation may as shown in Fig. Ia be arranged to correspond to two or even more lighting units 3, and there are accordingly five formations 8 provided in the first frame 6 and four formations 8 provided in the second frame 7. The series of formations 8 of the first frame 6 differs from the series of formations 8 of the second frame 7, such that each frame 6, 7 has a unique shape. Note however that a shape of a single formation 8 corresponding to a specific lighting unit 3 nevertheless may be identical for both frames 6, 7. Each formation 8 is adapted to, i.e. shaped, such that it in use couples with the corresponding lighting unit(s) 3, to thereby tilt the lighting unit 3 about its universal joint 4 to a predefined position.

Thus, in use, depending on the use of the first and second frames 6, 7, the lighting system 1 may, provided that the lighting units 3 are emitting light beams, support a plurality of illumination options in the irradiation plane 10. If neither the first nor the second frame 6, 7 is utilized (not shown) during use of the lighting system 1, the lighting units 3 are in this first embodiment at their default positions with the rods 5 unaffected by the frames 6, 7. As the lighting fixture 2 in the illustrated embodiment is horizontally arranged, the lighting units 3 each emit light beams in a direction perpendicular to the lengthwise direction of the lighting fixture 2, i.e. in a direction of a normal N of the lighting fixture 2. Consequently, if neither of the frames 6, 7 are utilized for coupling with the rods 5 during use of the system 1, the lighting units 3 emit light beams that form a respective light spot 9 for each lighting unit 3 in the irradiation plane 10. In the shown embodiment, that would equal six light spots 9. Note that the lighting fixture 2 not necessarily needs to have a horizontal orientation; it may likewise be arranged in a non-horizontal manner.

Utilizing the first frame 6 during use would on the other hand result in a different illumination effect. The mechanical movement of coupling the first frame 6 with the rods 5, here by lowering the first frame 6, may be accomplished for instance by hand or by utilizing small motors (not shown). In bringing the first frame 6 in contact with the rods 5, the lighting units 3 of this first embodiment are pivoted about their joints 4 in a direction essentially parallel to the lengthwise direction of the lighting fixture 2. When the first frame 6 has reached for instance an end position in coupling with the rods 5, the lighting units 3 have each been tilted to a respective predefined tilting angle α in comparison to the normal N; in Fig. Ia, lighting unit 301 is thus tilted to a predefined tilt angle (X₁. The predefined angles α are consequently defined by the shapes of the corresponding formations 8. If preferred (not shown), the frame 6 may be adapted to provide different predefined angles α depending on to what extent the frame 6 is lowered, i.e. the level of which the frame 6 is coupling with the lighting units 3. For instance, the frame 6 may be adapted to support three predefined coupling levels, each level realized at a respective degree to which the frame 6 is lowered. The three different levels may thus affect the frame 6 to tilt the lighting units 3 to three respective different predefined tilting angles α. Thereby, one and the same frame 6 may inherently represent three different angle adjustment means 6. It should once again be emphasized that although the lighting units 3 of this illustrated embodiment are tilted about their respective universal joints in a single direction essentially parallel to the lengthwise direction of the lighting fixture 2, the lighting units 3 may additionally be pivoted about their respective universal joints 4 in a second direction perpendicular to the lighting fixture 2. This may be accomplished by for instance adapting the formations 8 accordingly, for instance arranging at least one of the frames 6, 7 to couple with the lighting unit 3 at the end of the rod 5 not attached to the lighting unit 3.

In tilting the lighting units 3 to the predefined angles α in relation to the normal N, a plurality of light spots 9 are formed by the emitted light beams in the illumination plane 10. In the shown first embodiment, with the influence inflicted on the system 1 by the first frame 6, the six lighting units 3 are tilted such that their emitted light beams form two light spots 9 in the irradiation plane 10.

In Fig. Ib, the result of utilization of the second frame 7 instead of the first frame 6 is illustrated. As is depicted, in bringing the second frame 7 in contact with the rods 5, the lighting units 3 are pivoted, and when the second frame 7 has reached for instance an end position in coupling with the rods 5, the lighting units 3 have each been tilted to a respective predefined tilting angle β in comparison to the normal N. Utilizing the second frame 7, the lighting unit 301 is thus pivoted to the predefined tilt angle βi, which differs from the predefined tilt angle αi illustrated in Fig. Ia. From the influence inflicted on the system 1 by the second frame 7, the six lighting units 3 are in this first embodiment tilted such that their emitted light beams form three light spots 9.

Consequently, as shown in Figs. Ia and Ib, light beams emitted from one and the same set of lighting units 3 may form a different number of light spots 9 in the irradiation plane 10 depending on if, and which, angle adjustment means 6, 7 is utilized during use of the lighting system 1. Furthermore, since the total amount of flux, i.e. light beams, provided from the lighting units 3 is fixed regardless of angle adjustment means 6, 7 used, the distribution of the flux to the different light spots 9 is consequently dependant on the predefined tilt angles α, β, and subsequently, on the predefined formations 8 of the respective angle adjustment means 6, 7. Accordingly, the amount of flux for a specific light spot 9 may thus vary with the number of lighting units 3 inflicted to emit light beams forming that specific light spot 9.

A more comprehensive lighting system 1 may for instance comprise as many as 72 lighting units 3 (not shown). With a flux of e.g. 100 Im per lighting unit 3, such a lighting system 1 could support combinations such as: 2 light spots composed of 36 lighting units, with 3600 Im per light spot

3 light spots composed of 24 lighting units, with 2400 Im per light spot 6 light spots composed of 12 lighting units, with 1200 Im per light spot Note however, that although in the given example above the respective light spots 9 have an even distribution of the flux, the invention is not limited thereto. The lighting units 3 may likewise be tilted such that for two light spots 9, one of the light spots 9 is formed of for instance 24 lighting units, and the other of 48.

In Fig. 2a, an exemplifying lighting system 2 in accordance with a second embodiment of the present invention is illustrated. Most elements and their features are identical to those in the first embodiment of Fig. 1, why only differences between the two embodiments will be described hereinafter.

In a lighting system 21 in accordance with the second embodiment, the frames 6, 7 of Fig. 1 have been replaced by a cylinder 26 stretching along the lighting fixture 2, i.e. along the lighting units 3. Here, the cylinder 26 is continuously coupled with the rods 5 of the lighting units 3, not only during use. The cylinder 26 is rotatable in its lengthwise direction, and preferably mounted to the lighting fixture 2 in at least one of its ends. The cylinder 26 may furthermore preferably be solid, or semi- so lid, for instance of metal or plastic material, with predefined formations 28. Other materials may of course be feasible. In this second embodiment, the formations 28 are represented by slits carved out of the cylinder 28, at positions corresponding to each lighting unit 3. Each slit 28 stretches, at least to some degree, along the diameter of the cylinder 22. Although in the illustration each slit 28 stretches along the entire diameter, the invention is not restricted thereto. Each slit 28 is furthermore to some extent twisted along the diameter of the cylinder 26, and the depth of the slit 28 may additionally vary along the diameter in a predefined manner. Consequently, each slit 28 has its own unique predefined form adapted to couple with the corresponding lighting unit 3 to thereby tilt the lighting unit 3 about its universal joint 4 to a predefined position, i.e. tilt angle α, β.

Thus, in use, in its default position, the exemplifying cylinder 28 of this second embodiment couples with the rods 5 of the lighting units 3, such that they remain in their default positions. Here, each slit 28 is adapted to affect the corresponding lighting unit 3 to emit light beams in a vertical direction, such that each lighting unit 3 forms an individual light spot 9 in the irradiation plane 10. In the illustration, with six lighting units 3, six individual light spots 9 are thus formed. In rotating the cylinder 26 around its own axis, the specific characteristics of each slit 28 affect the corresponding rod 5, and thus the subsequent movement of the corresponding lighting unit 3. Consequently, as is depicted in Fig. 2b, by for instance rotating the cylinder 26 a quarter of a turn, the lighting units 3 are tilted about their axes in a direction essentially parallel to the length direction of the cylinder, such that each lighting unit 3 is arranged in a predefined manner. According to this embodiment, at this rotation angle of the cylinder 26, the light beams emitted from the lighting units 3 form a single light spot 9 in the irradiation plane 10. Note that the number of predefined positions to which the lighting units 3 may be tilted is defined by the characteristics of the slits 28. For instance, rotating the cylinder 26 45° may tilt the lighting units 3 to a specific set of predefined positions, and rotating the cylinder 135° to another set of predefined positions; each degree of rotation resulting in different characteristics of the light spots 9. Thus, it is to be emphasized that in realizing the angle adjustment means 26 by means of a cylinder, a single cylinder 26 may consequently represent a plurality of inherent adjustment means. It may furthermore be emphasized that a plurality of cylinders 26 of course may be provided.

As previously stated, the lighting units 3 do not necessarily need to be arranged in a linear formation. Likewise, the lighting units 3 may in accordance with a third embodiment be arranged in a matrix formation, as shown in Fig. 3. It should be emphasized that a "matrix" formation should be interpreted in a broad sense, including a formation of lighting units 3 extending in two directions. Most elements and features of this third embodiment are identical to those of the first and second embodiments, why only the differences are described hereinafter.

In a lighting system 31, in accordance with this exemplifying third embodiment, the elongated lighting fixture 2 of Figs. 1 and 2 has been replaced by a rectangular lighting fixture 32, which enables lighting units 3 to be mounted thereto in a matrix formation. In order to couple with the rods 5 of all four lighting units 3 simultaneously, an angle adjustment means 36 extending over essentially the entire rectangular lighting fixture 32 is provided, shown in an exp loaded view in Fig. 3. Note that the shape of the illustrated angle adjustment means 36 merely is exemplifying, and that the present invention to no extent is limited thereto. Any shape of the angle adjustment means 36 resulting in the desired described effect may be utilized. It should also be emphasized that although only a single angle adjustment means 36 is illustrated in Fig. 3, any number of adjustment means 36 is likewise covered by the inventive scope. Preferably, at ends which in use couples with the lighting units 3, the rectangular lighting fixture 32 is preferably solid, or semi-solid, for instance of metal or plastic material, with predefined formations 8. Other materials may of course be feasible. The formations 8 are here cut-out holes similar to those in Fig. 1; other options are naturally likewise possible.

Although in this third embodiment only four lighting units 3 are illustrated to form a matrix, the invention is not limited thereto. The lighting system 31 may for instance likewise comprise six plus six lighting units, whereby the rectangular angle adjustment means 36 in the ends which, in use, couples with the lighting units 3 would resemble the elongated frames 6, 7 of the first embodiment illustrated in Fig. 1.

Additionally, in this third embodiment, the rectangular angle adjustment means 36 is adapted to, in use, couple with the rods 5 of the two lighting units 3 disposed in the rear of the matrix in such a manner that the these lighting units 3 are tilted about not only one, but two axes. This is in the illustration achieved by the formation 8 in the rear of the rectangular angle adjustment means 36 having a shallower cut-out hole than the formation 8 in the front. Additionally, the angle adjustment means 36 is arranged to couple with the rear lighting units 3 at the end of their respective rods 5 not attached to the lighting unit 3. Consequently, in use of the lighting system 31, utilizing the rectangular angle adjustment means 36, two light spots 9 are formed in the irradiation plane 10, as shown in Fig. 3. In the exemplary embodiments of the present invention described above, the angle adjustment means described have been essentially solid, or semisolid, with the formations being either cut or carved out of the means. It would however be possible, and within the scope of the present invention, to use different types of angle adjustment means. For instance, angle adjustment means may according to other embodiments have the shape of a slidable bearer disposed essentially in parallel with the lengthwise direction of the lighting fixture, from which bearer, for instance for each lighting unit, a respective fork-like arm comprising irregular teeth is extending. A first gap between two teeth of an arm may represents a formation of a first angle adjustment means, and a second gap between two other teeth of that same arm may represent a corresponding formation of a second angle adjustment means. The respective formations of the first and second angle adjustment means are thus shaped to, in coupling with the rods, tilt the lighting units to respective predefined tilting angles. During use, the respective angle adjustment means may be chosen for utilization by sliding the bearer to a position representing the first or second angle adjustment means, and lowering the bearer such that the formations, i.e. gaps, of the chosen angle adjustment means couples with the corresponding lighting units.

According to yet another example, the shape of an angle adjustment means may be optimized for formations comprising magnets, by which magnets the corresponding lighting units, also having adjustment portions comprising magnets, are affected to be pivoted to their respective predefined positions.

Furthermore, the skilled addressee realizes that the present invention by no means is limited to the preferred embodiments described above. On the contrary, the skilled addressee understands that many modifications and variations are possible and within the scope of the appended claims.

Claims

CLAIMS:

1. A lighting system (1, 21, 31) for selective illumination in an irradiation plane (10), comprising: a lighting fixture (2, 32); at least two lighting units (3) tiltably mounted to said fixture (2, 32) and each arranged to emit a beam of light towards said irradiation plane (10) at a variable tilt angle in relation to a normal (N) of said lighting fixture (2, 32), wherein each of the units (3) comprises a light source and an adjustment portion (5); and a first angle adjustment means (6, 26, 36) having predefined formations (8, 28), wherein the predefined formations (8, 28) are adapted to, in use, couple with said adjustment portion (5) of each of said units (3) for tilting each of the units (3) about at least one axis to respective first predefined position, such that beams of light emitted by each of said units (3) are provided at respective first predefined tilt angles (α).

2. The lighting system (1, 21, 31) in accordance with claim 1, further comprising a second angle adjustment means (7) having predefined formations (8), wherein the predefined formations (8) are adapted to, in use, couple with said adjustment portion (5) of each of said units (3) for tilting each of the units (3) about at least said one axis to respective second predefined position, such that beams of light emitted by each of said units (3) are provided at respective second predefined tilt angles (β).

3. The lighting system (1, 21, 31) in accordance with claim 1, wherein said light source (3) comprises a light emitting diode (LED).

4. The lighting system (1, 21, 31) in accordance with claim 1 or 2, comprising at least three lighting units (3), wherein said lighting units (3) are arranged in a linear formation.

5. The lighting system (1, 21, 31) in accordance with any one of the preceding claims, comprising at least three lighting units (3), wherein said lighting units (3) are arranged in a matrix formation.

6. The lighting system (1, 21, 31) in accordance with any one of the preceding claims, wherein said lighting units (3) each are mounted to said fixture (2, 32) by a respective universal joint (4) allowing said units (3) to tilt about said at least one axis.

7. The lighting system (1, 21, 31) in accordance with any one of the preceding claims, wherein the formations (8, 28) of said angle adjustment means (6, 7, 26, 36) comprises cut out holes in a solid body.

8. The lighting system (1, 21, 31) in accordance with any one of the preceding claims, wherein said adjustment portion (5) of at least one of the lighting units (3) comprises a rod extending from said unit (3), said rod (5) being adapted to cooperate with said angle adjustment means (6, 7, 26, 36).

9. The lighting system (1, 21, 31) in accordance with claim 2, wherein said first

(6) and second (7) angle adjustment means each has the form of a frame stretching along said lighting units (3), said first (6) and second (7) means being arranged in parallel to each other in a direction of said stretch, and said lighting fixture (2, 32) being arranged in between said irradiation plane (10) and said first (6) and second (7) means.