EP3465315A1

EP3465315A1 - Optical lens for illumination purposes

Info

Publication number: EP3465315A1
Application number: EP17731813.6A
Authority: EP
Inventors: Daniel Hauser; Anton Flir; Walter Ebner
Original assignee: Swareflex GmbH
Current assignee: Swareflex GmbH
Priority date: 2016-06-04
Filing date: 2017-06-01
Publication date: 2019-04-10
Also published as: WO2017207683A1; CN109313325A; US20200200361A1

Abstract

Optical lenses for illumination purposes (L) are proposed, comprising a lateral surface (C) and a light exit surface (B), wherein the underside is shaped in a plane fashion and has an optical relevant cutout for receiving a light source, which is distinguished by the fact that the lens (L) has a lateral surface (C) that is wholly reflectively coated, and has a light exit surface (B) having the two vertices (b1) and (b2), wherein (b1) and (b2) represent respectively the highest and lowest vertices upon the transition from the light exit surface (B) to the lateral surface (C).

Description

OPTICAL LENS FOR LIGHTING PURPOSES

FIELD OF THE INVENTION

The invention is in the field of traffic engineering and relates to specially designed lenses for use in lighting devices for tunnels and the lighting devices containing the lenses.

STATE OF THE ART

The illumination of traffic tunnels is a challenge for optics design and lighting design due to strict lighting standards. Particularly the tunnel access area is critical because the human eye has to adapt to the rapidly changing brightness conditions (adaptation). In addition, the perceived glare in the passage of the tunnel is an important criterion and standardized by the legislature.

An illumination concept that has become established in the tunneling sector in recent years is the so-called co-jet and counter-jet principle. In the co-jet principle, the projection of the main radiation direction on the road runs parallel to the direction of travel, while the counter-jet principle, the projection is anti-parallel to the direction of travel. The mode of operation is also shown in FIG. 4, with the co-jet principle on the left and the counterjet principle on the right.

The advantage of the Mitstrahlprinzips lies in a glare of the lamp and in high contrast quality coefficients. The co-radiation is used for example in the passage in traffic tunnels. The counterjet principle allows a high luminous efficacy, which is especially required in the tunnel access area. As a result, the number of luminaires and lamps can be reduced and required standard specifications can be achieved more efficiently. In addition, the counterjet principle is used in the tunnel entrance area to produce the desired luminance profile for the adaptation of the eye.

Tunnel luminaires with different suitability criteria are already known from the prior art: Thus, EP 2093484 B1 (BARTEN BACH) discloses tunnel luminaires which contain a heat buffer for buffering external ambient or external heat acting on the luminaire, comprising a heat store (2) with a phase changer whose phase change temperature ranges from solid to liquid and / or or from liquid to gaseous below the permissible limit operating temperature of the luminaire and above the normal operating temperature of the luminaire. Such a heat accumulator absorbs so to speak the heat acting on the lamp in case of fire, whereby heating of the lamp or its components over the respective permissible limit temperature is prevented. However, the document contains no disclosure in the direction of the design of an optical lens.

In EP 2565525 Bl (BARTENBACH), however, lamps are described in which the lenses are arranged exposed and one side on the opposite side facing the direction of travel of the lenses each have a hump-shaped edge elevation, which is provided on its outer side with an inwardly effective reflective coating , has a height above the base of the lens of at least 125% of the maximum height of the remaining body of the lens and substantially captures scattered light emitted by soiling on the light exit surface of the lens opposite to the direction of travel.

The subject of EP 2112428 Bl (BARTENBACH) is a road, in particular tunnel lamp with an asymmetrical light intensity distribution. The luminous flux of the luminaire is thereby limited to a half space lying behind the luminaire in the direction of travel. The lamp has a Ausblendraum, which includes the viewed in the direction of travel in front of the light half-space. By illuminating the tunnel or the road area in the direction of travel, vehicles driving in front of a specific vehicle are, so to speak, illuminated from behind, so that they are clearly visible to the driver driving behind them. On the other hand, glare-free operation is achieved by hiding the half-space oriented counter to the direction of travel. The subject of EP 2962998 AI (SWAREFLEX) are also tunnel lenses, which are characterized in that they have a light exit surface in ellipsoidal freeform, the lower sides are plan shaped and provided with an optically relevant recess for receiving a light source and the lenses of a glass with a special composition and a defined refractive index.

From US 7,799,509 Bl and WO 2012/080889 AI optical units for lighting purposes are known.

Optics systems with asymmetrical light distributions have the advantage that they allow well adapted light distributions. The previous approach is a transparent freeform lens, also with cover and / or Teilverspiegelung the lateral surface to produce the desired light distribution. However, the prior art has considerable problems: in particular, a part of the luminous flux is absorbed by the cover, whereby the efficiency of the luminaire drops below 60%. Also, the partial mirroring of the lateral surface is disadvantageous, because it must be used a complex lens shape to obtain the desired light deflection on the mirrored surface. The partial mirroring of individual delimited lateral surfaces also have a negative effect on the producibility of the optical system. Finally, the light distributions produced are highly dependent on production tolerances. In general, previous optical systems have the disadvantage that their light distributions do not have the optimum accuracy and thus lead to luminous flux losses or disturbing glare.

These disadvantages often complicate or prevent the use of such optical concepts in traffic tunnels.

The object of the present invention has therefore been to provide an alternative lighting concept for tunnels that completely overcomes the above-described disadvantages of the prior art. In particular, the following subtasks should all be solved simultaneously:

• use of basic simple geometric shapes;

• Easy to produce, both with regard to the lens body and the coating;

• Minimization of Fresnel losses with simultaneously increased light output;

Minimizing the perceived radiating area;

• reduction of glare in the co-jet principle;

· Increased luminous flux yields in both the co-jet and counterjet principle;

• Possibility to achieve any asymmetrical light distribution;

• Reduced color-over-angle effect (light emitted at a narrow angle is white-bluish, but light that is emitted at a wide angle has a yellow or yellow-red sting, a phenomenon known as color-over -Angle "(CoA)), as well as

• Easy drainage of liquid residues.

DESCRIPTION OF THE INVENTION

A first subject of the invention relates to optical lenses for illumination purposes (L), comprising a jacket (C) and a light exit surface (B), wherein the underside (A) is formed flat and has an optically relevant recess for receiving a light source, characterized that the lens (L)

(a) has a jacket (C) coated in a completely reflective manner, and

(b) has a light exit surface (B) with the two vertices (bl) and (b2), wherein (bl) and (b2) represent the highest and lowest vertices at the transition from the light exit surface (B) to the jacket (C).

Under the coat, the outer surface of the lens molding is understood, which connects to the light exit surface and the flat bottom. In other words, the jacket represents the outer surface of the lens molding, without the light exit surface and without the flat underside with its light entrance surface. The lenses are further distinguished by the fact that the light exit surface (B) is designed either flat or curved. If the surface is flat, then the base area (Bl) of the light exit surface and the light exit surface (B) coincide. If, on the other hand, the surface is curved, that is to say concave, convex or concave-convex, the base surface (Bl) of the light exit surface and the tangential plane to the light exit surface (B) are parallel to each other.

The lenses are viewed from the side (which means with regard to the edge of the base Bl) not necessarily symmetrical. This means that z. B. the side which has the light exit surface may be wider than the other. This is also illustrated in FIG. 1, for example. However, it is equally possible that both sides are the same width, or that the side that does not have the light exit surface is wider. In a preferred variant, viewed from the side, the side which has the light exit surface is wider.

The lenses according to the invention can also have mounting aids in some embodiments on their underside. These assembly aids can in principle be any known assembly aids. In preferred embodiments, these can be tabs or, in particular, one or more positive-locking connection elements. In some embodiments, it is particularly preferred that the lenses according to the invention have on their underside a form-locking connecting element in the form of a flange running around the lens.

The optical lenses according to the present invention, which have an assembly aid on their underside, accordingly have an outer surface extension of the underside. In such embodiments, the lateral surface is limited downwards by the edges of the mounting aids. Accordingly, the reflective surface is limited by the edges of the mounting aids. In the event that the assembly aids are several assembly aids in the form of tabs or the like, the lateral surface C is located both above the respective upper edges of the tabs and in the spaces between the corresponding tab edges. In the event that the positive connection element is a flange, the reflective surface of the jacket C or the jacket C extends to the flange upper edge.

The embodiments of the present invention in which the lenses according to the invention have an assembly aid on their lower side have various advantages.

An important advantage is that with these mounting aids a better attachment is possible. Due to the enlarged bottom support surface of the lenses according to the invention, the available adhesive surface is increased. Accordingly, the adhesion of the lenses of the invention on the support is improved.

In addition, it is advantageous to have a larger adhesive surface, since in the case of the adhesive more outward, i. further away from the recess for receiving a light source in the base of the lenses according to the invention, can be applied; This can be prevented (or at least significantly reduced) that adhesive flows into the recess or that volatile components, in particular of the adhesive, get into the recess. Accordingly, the risk of contamination or damage to the light source and / or light entry surface of the lenses is minimized or excluded.

In addition, it is an advantage that in the event that the lenses are embedded in a potting compound, the lenses according to the invention are anchored better (more firmly) in the potting compound. This considerably increases the stability of the corresponding assembly.

Of course, it is also possible, the lenses according to the invention on the mounting aids in addition to or instead of bonding mechanically with the Connecting carrier; preferred options for this are screws or rivets. Other mechanical connection options are also used, such. B. brackets. The optically relevant recess for receiving the light source is a curved light entry surface, which is concave or concave-convex incorporated in the lens body; Accordingly, it can also be referred to as a concave or concave-convex in the lens body incorporated curved light entrance surface. A concavo-convex curved light entrance surface has areas that are concavely curved.

In a preferred variant, the curved light entry surface is elliptical.

In other embodiments, the light entry surface is not curved, but, for example, plan, square, square, etc .; however, it must be ensured that enough light can enter the lens.

The lenses according to the present invention in a preferred embodiment, a curved light entrance surface, which may be elliptical, a reflective, preferably reflective coated shell, and a flat or curved light exit surface, which may be inclined. The shape of the lens system is preferably reduced to simple basic geometrical shapes. In particular, the generation of the optical system by a small number (> 2) of simply parameterized surfaces and bodies results in a lens shape which is easy to process in production. The limitations in the design of the light distribution due to the simple basic shape of the lens are offset by the fully coated reflective edge surface. Thus, a light beam can be reflected at any incident angle at the edge surface with high efficiency, without relying on the TIR effect. Because unlike TIR lenses (TIR = Total Internal Reflection), the light output according to the present invention is higher, since no Fresnel losses occur in the reflection at the edge of the lens. In addition, a light beam can be reflected at any angle of incidence without relying on the TIR effect. This results in further degrees of freedom in the design of the Light distribution. In contrast to TIR systems, so-called "frustrated total reflection" can not occur, as a result of which the light output couples into adjacent media In a variant of the present invention, the lenses consist of a single piece of lens body and, if appropriate, of the coating.

Likewise, as a result of the fully coated coating or, preferably, reflective coating and the light source thereby at least partially concealed, the perceived radiating surface is significantly reduced in comparison to conventional lens systems. This offers the possibility of a nearly perfect glare reduction in the co-jet principle as well as high luminous efficacy yields with co- and counter-beam luminaires, whereby the fully coated mirror coating is no problem for common coating processes. It is possible to use the jacket, i. the outer surface of the lens molding to be coated only in certain areas, namely in the areas in which the light emitted from the lighting body is not totally reflected within the lens body anyway and thus can not pass through the jacket.

Finally, the efficiency of the light bundling is higher than with lens systems with covers, whereby standard specifications can be achieved more easily.

In addition, the angles of inclination of the light exit surface as well as of the entire glass body can be varied greatly in order to direct the rays of the light source and to produce the desired light distribution. The relative position of the light entry surface to the remaining lens system can additionally be used to further modify the light distribution. These degrees of freedom enable the generation of arbitrarily asymmetrical light distributions, which are not possible with conventional lens systems or only with large losses. For the bundling of light, the curvatures of the light entrance and light exit surfaces and of the jacket are decisive. Furthermore, the relative position and size of the cross section of the light exit surface plays an important role in the light bundling. Lie at least a portion of the surface or the entire surface is faceted, it is also possible to achieve particularly homogeneous light distributions.

A further advantage of the present invention is that the so-called "color-over-angle" effect can be better controlled with the aid of the new lens, which leads to better conditions in the use of illumination when color gradients are undesirable.

The shape of the lens also offers in particular the possibility to install a drip edge, which is particularly advantageous in road traffic. Due to the chamfering of the light exit surface possible liquid residues flow to the photometrically uncritical edge region of the optical system and drop from there. This reduces the formation of soiling that can negatively affect the efficiency and light distribution.

DETAILED DESCRIPTION OF THE LENSES

The lenses according to the invention are illustrated in FIGS. 1a and 1b. The reference numerals have the following meanings:

A = flat underside with recess for the light source

B = light exit surface

Bl = base area of the light exit surface

C = reflective surface = jacket

L = lens body

a = center of the curved light entry surface

bl = vertex of the lens body and upper limit of the light exit surface

b2 = lower limit of the light exit surface

c = height of the lens body

cl = height of the lens body up to which the light exit surface extends c2 = difference between c and cl (not shown)

α (alpha) = inclination angle

Reflecting surfaces are represented by solid lines. Light entry and exit surfaces are shown by dashed lines. The vitreous body is shown in gray.

The light exit surface itself preferably has the shape of an ellipse, in the special case the shape of a circle. Preferably, the lenses have a height - measured from the planar base area (A) to the vertex (bl) - of about 0.5 to about 10 cm, preferably about 1 cm to about 5 cm and in particular from about 2 to about 3 cm , However, this surface can be made arbitrarily more complicated, for example by including or excluding edges from the surface.

The base of the light exit surface can be considered as an oblique section through the lens body, which attaches to the vertex (bl) of the lens and down to point (b2) down to a height (cl), which is about 5 to about 75%, preferably about 10% to about 50%, and more preferably about 15 to about 25% of the total height (c) of the lens. In particular, this surface has an inclination or this section has an angle α. The inclination angle α of the base is the angle between the normal of the base (Bl) and the normal of the flat underside (A). A positive angle α is created by a rotation to the right in the direction of the vertex (b2), a negative angle by a rotation to the left, ie in the direction of the vertex (bl). The inclination angle α ranges from -90 ° to + 90 °. Preferably, the angle range α is about -45 ° to about + 45 ° and in particular 0 to about +30 °.

FIG. 1b differs from FIG. 1a only in that a flange is now shown in the lower part. In this case, the light entry surface - in this figurative representation - partly hidden by the flange shown (at the level of the lens base). The jacket C leads to the upper end of the flange.

The inclination of the base area influences the main emission direction. The curvature of the light exit surface influences the light distribution. Of the The angle of inclination of the base area α and the curvature of the light exit surface can be adapted to the lighting requirements.

Figure 2a shows a wire frame sketch of a lens according to the invention, in which the curved surface above the base surface Bl of the light exit surface is not visible due to the perspective.

FIG. 2b shows a wire frame sketch of a lens according to the invention, in which the curved surface is shown above the base area B1. LENS BODY AND COATING

The lens body can in principle be made of any translucent polymer which can be coated. Preferably, however, they are vitreous bodies, since they are distinguished by particularly precise light irradiation combined with high resistance.

The nature of the coating can also be of a variety of types, ranging from aluminum vapor deposition, to coating with silver, gold or other metals. However, it is advisable to carry out the coating or to adjust such a layer thickness that results in a reflectivity of at least 80%, preferably at least 90 and in particular at least 95%. As a coating method, for example, wet-chemical processes in question, but also CVD, PVD or sputtering in particular.

LIGHT

The light sources can in this context LED, OLED, LET or OLET represent; also a laser illumination is possible.

LED, also referred to as light-emitting diodes, constitute light-emitting semiconductor components whose electrical properties correspond to those of a diode. Flows through the diode electric current in the forward direction, Thus, it emits light, IR radiation to UV radiation with a wavelength dependent on the semiconductor material and its doping.

High power light emitting diodes (H-LED) operate at higher currents than 20 milliamps. There are special requirements for heat dissipation, which are expressed in special designs. The heat can be dissipated via the power supply lines, the reflector pan or heat conductors incorporated in the light-emitting diode body. Other suitable LED versions that can be used as light sources in the context of the present invention include the direct wire bonding of the light-emitting diode chip on the board (chip on board) and the subsequent casting with silicone compounds. The LEDs used as light sources can also be multicolored. Multi-colored light-emitting diodes consist of several (two or three) diodes in one housing. Most of them have a common anode or cathode and a connector for each color. In a two-terminal version, two LED chips are connected in anti-parallel. Depending on the polarity, one or the other diode lights up. A quasi-continuous color change can be realized via a variable pulse width ratio of a suitable alternating current.

Another possible light source according to the invention are OLEDs. These are organic light-emitting diodes, or more precisely luminous thin-film components made of organic semiconducting materials, which differ from inorganic light-emitting diodes (LEDs) in that the electric current density and luminance are lower and no monocrystalline materials are required. Compared to conventional (inorganic) light-emitting diodes, organic light-emitting diodes can therefore be produced more cost-effectively in thin-film technology. OLEDs are made up of several organic layers. In most cases, a hole transport layer (HTL) is applied to the anode consisting of indium tin oxide (ITO), which is located on a glass pane. Between ITO and Depending on the manufacturing method, HTL is often applied with a layer of PEDOT / PSS, which serves to lower the injection barrier for holes and prevents indium from diffusing into the junction. On the HTL, a layer is applied, which either contains the dye (about 5-10%) or - rarely - completely consists of the dye, z. Aluminum tris (8-hydroxyquinoline), Alq3. This layer is called emitter layer (EL). Optionally, an electron conduction layer (ETL) is applied to these. Finally, a cathode, consisting of a metal or an alloy with low electron work function such as calcium, aluminum, barium, ruthenium, magnesium-silver alloy, evaporated in a high vacuum. As a protective layer and to reduce the injection barrier for electrons, a very thin layer of lithium fluoride, cesium fluoride or silver is usually vapor-deposited between the cathode and E (T) L.

Instead of the light-emitting diodes, it is also possible to use corresponding transistors, which are referred to as LET or OLET.

The light sources are applied to or inserted in a suitable carrier. If appropriate, more than one light source is also used, for example 5, 10, 15, 20 or, if required, more, which are arranged either in rows or circles. Each of the light sources attaches one of the inventive lenses, the recess in the lens being adapted to the light source. These recesses are generally elliptical with respect to their base, preferably circular, but may in principle also have any other shape. The fixation is done by gluing the lens to the carrier, wherein the, formed by the rest of the underside remaining around the bottom, peripheral edge provides a better grip while preventing the ingress of moisture. Preferably, the lenses are encapsulated with the unit of support and light source by means of, for example, epoxy resin.

INDUSTRIAL APPLICABILITY Another object of the present invention relates to a lighting device comprising

(a) at least one optical lens according to the present invention;

(b) at least one light source as well

(c) a support for receiving the light source (s) and lens (s).

In order to integrate the lenses mechanically stable in luminaires, various carriers or mounting techniques are used. In classical optics systems, a part of the luminous flux is usually absorbed and / or deflected. This can lead to lower efficiencies and altered light distribution of the luminaire. The new lens system is completely independent of effects of this kind due to the very reflective coated jacket, which leads to an increase in efficiency of the entire luminaire. In one embodiment of the present invention, the support has at least one ventilation hole in the immediate vicinity of the light source (s) and within the base surface (s) of the recess (s) of the optical lens (s) according to the invention, whereby volatile constituents which are For example, may come from the bonding of the lenses on the support, can diffuse out of the / lens recess (s) out. This has several advantages, among other things, it can prevent the surface of the light source and / or the lens according to the invention from being contaminated and / or damaged by reaction with the volatile constituents.

In a further embodiment, the illumination device comprises a plurality of lenses arranged on the carrier, wherein it is preferred if lenses are arranged regularly.

Typical embodiments are lighting devices comprising about 1 to 200, preferably 1 to 60, more preferably about 10 lenses; but there are also lighting devices with even more lenses possible.

In a preferred embodiment, the light exit surfaces B of all lenses on the carrier are aligned in the same direction. For other applications However, it is also possible to align the light exit surfaces B in different directions, either in groups or individually.

A further subject of the invention also relates to a method for illumination, comprising the following steps:

(a) providing at least one lighting device as described above;

(b) mounting the at least one lighting device; and

(c) connecting the at least one lighting device to a power supply.

The method relates to the illumination of different objects, such as roads, airports, ship harbors, industrial plants, playgrounds and sports facilities. In particular, it is suitable for the illumination of tunnels. The mounting can be done in any suitable way, for example on roofs, walls, masts or cranes. In the case of tunnel lighting, the elements are installed in the ceilings or at a suitable height in the possibly inclined walls. The installation in existing power strips is possible.

A final object of the invention relates to the use of the optical lenses according to the invention or the lighting device containing them for lighting, for example, streets, airports, ship harbors, industrial plants, playgrounds and sports facilities and in particular tunnels and on the other for the illumination of surfaces.

EXAMPLES EXAMPLE 1, COMPARATIVE EXAMPLES VI TO V3

To further elaborate the differences of the new optical system, lighting simulations of three classical lenses and the new lens system performed. The simulation setup is identical for all lens systems and is structured as follows:

1. Set the LED in the origin of coordinates.

2. Set the lens CAD geometry.

3. Setting the reference coordinates of the LED lens system.

4. Acquisition of the luminous intensity distribution in polar coordinates.

5. Set a rectangular area detector at a constant distance and constant size to calculate the luminance distribution. FIG. 3 shows the results of the photometric simulation of the various optical systems. The lens system 1 (Figure 3a) and lens system 1 with cover (Figure 3b) are already produced lens systems that are used in road traffic. Lens system 2 (Figure 3c) represents a simulation concept of a pure lens optics, which is barely reached prescribed standards in road traffic and also difficult to produce. Figure 3d represents the new optics system.

The optical efficiency of the lens systems is denoted by η. The light intensity distribution curves are shown in the upper halves of FIGS. 3a to 3d and the luminance distributions in the lower halves. The horizontal lines mark the separation between secondary and main emission planes of the lenses. The dot in the center of the luminance distribution represents the position of the lens. The absolute brightness of the luminance distributions is normalized to the respective luminance maximum for each example.

Lens system 1 has an optical efficiency η = 86%.

Lens system 1 with cover has an optical efficiency η = 56%.

Lens system 2 has an optical efficiency η = 82%.

The optical system according to the invention has an optical efficiency η = 82-85%.

The results of the photometric investigation of the four optical systems, which are shown in Figure 3a to 3d, illustrate the advantage of the present invention. This is much less light in the rear Image plane thrown. In comparison with the lens system 1 with cover, a similar amount of light falls in the rear image plane, however, the efficiency is up to 30% higher due to the reflective shell of the new design. In contrast to classic single-lens systems, the new optical system enables the production of much more efficient luminaires, which can also produce a more asymmetric light distribution.

Claims

Optical lenses for lighting purposes (L), comprising a jacket (C) and a light exit surface (B), wherein the underside (A) is shaped flat and has an optically relevant recess for receiving a light source,

characterized in that the lens (L)

(a) has a jacket (C) coated in a completely reflective manner, and

Lenses according to claim 1, characterized in that it has on its underside an assembly aid, preferably a positive connection element, particularly preferably a flange

Lenses according to claim 1 or 2, characterized in that the light exit surface (B) is designed plan.

Lenses according to claim 1 or 2, characterized in that the light exit surface (B) is designed curved.

Lenses according to claim 3, characterized in that the base surface (Bl) of the light exit surface and the light exit surface (B) coincide.

Lenses according to claim 4, characterized in that the base surface (Bl) of the light exit surface and the tangential plane to the light exit surface (B) are parallel to each other.

7. Lenses according to at least one of claims 1 to 6, characterized in that it calculates a height (c) from the center (a) of the flat underside (A) to the vertex (bl) of the lens of about 0.5 to about 10 cm.

8. Lenses according to at least one of claims 1 to 7, characterized in that the base (Bl), attaches to the vertex (bl) of the lens and up to the apex (b2) down to a height (cl) extends down to about 5 to about 75% of the total height (c) corresponds to the lens.

9. Lenses according to at least one of claims 1 to 8, characterized in that the base (Bl) has an angle α, which is spanned between the normal of the base (Bl) and the normal of the flat bottom (A) and of -90 ° to + 90 °.

10. Lenses according to claim 9, characterized in that the base (Bl) has an angle α, which is spanned between the normal of the base (Bl) and the normal of the flat bottom (A) and from -50 ° to + 50 ° or 0 to + 45 °.

11. Lenses according to at least one of claims 1 to 10, characterized in that the light source is an LED or an OLED.

12. Lighting device comprising

(A) at least one optical lens for illumination purposes according to at least one of claims 1 to 11;

(b) at least one light source as well

(c) a support for receiving the light source (s) and lens (s).

13. Method of lighting comprising the following steps:

(A) providing at least one lighting device according to claim 12;

(b) mounting the at least one lighting device; and (c) connecting the at least one lighting device to a power supply.

14. Use of the optical lenses according to at least one of claims 1 to 11 or the illumination device according to claim 12 for illumination.

15. Use of the optical lenses according to at least one of claims 1 to 11 or the illumination device according to claim 12 for illuminating surfaces.