CH722494A2 - Leuchte - Google Patents

Description

TECHNICAL AREA

[0001] The present disclosure relates to a luminaire, in particular a luminaire for illuminating an interior or exterior space in a public or private area.

BACKGROUND OF THE REVELATION

[0002] Light focusing is a key concept in lighting technology, aiming to concentrate light precisely in a defined area. Modern luminaires, especially those with LED technology, utilize precise optical systems to maximize efficiency, functionality, and light quality.

[0003] In contrast, light blocking is a technique that specifically prevents light from emitting in unwanted directions. This is achieved using optical shielding elements such as reflectors, baffles, and light shields.

[0004] EP3792549A1 discloses an optical device comprising a lens with a light-entry surface and a light-emission surface. The light-entry surface has prismatic surfaces and, in particular, V-shaped projections in the central region to direct light largely in a single direction.

[0005] US10323824B1 discloses a light fixture with a linear LED array and a Fresnel-type lens covering the LED array. The lens has a first surface where the light enters and a second surface where the light exits. In particular, the lens features a variety of light-directing prismatic structures. Furthermore, the lens can be divided into multiple sections and can be made of materials with different optical properties. A wide beam angle is achieved, largely within a hemisphere around the light fixture.

[0006] US2016320017A1 discloses a light beam control module with a body that includes an optical axis and several structured surfaces. A light-intake surface is located on the inside of the body, and a light-emission surface is located on the outside. This achieves omnidirectional light emission into a hemisphere around the luminaire.

[0007] FR3146976A1 discloses a lighting device comprising a light guide. Reflective prisms are arranged on the back of the light guide.

[0008] CN206412378U discloses an LED backlight for a TV screen comprising an LED substrate, fluorescent silica gel, and a two-part convex spherical silicone lens. A secondary lens is avoided.

SUMMARY OF THE REVELATION

[0009] Luminaires known from the prior art have complex geometries and are therefore difficult to manufacture. Furthermore, light loss can occur due to light shielding, and reflection or scattering can also occur, which can impair the overall efficiency of the luminaires. Luminaires that rely on specific geometric shapes are also less flexible in adapting to the spaces to be illuminated and the desired lighting requirements.

[0010] One object of the invention is to provide a luminaire that enables light control with low light loss and is also easier to manufacture. A further object of the invention is a method for manufacturing a light-controlling element for such a luminaire, as well as a method for manufacturing a luminaire with the light-controlling element.

[0011] This problem is solved by the subject matter of the independent claims. Preferred embodiments are disclosed from the dependent claims, combinations of claims, and from the description in conjunction with the figures.

[0012] In a first aspect, a luminaire according to the present disclosure comprises a light source. A light source can be a single light-emitting diode (LED) or an LED array, e.g., a plurality of LEDs. The light source can, in particular, be controlled from an on-state to an off-state; however, continuous illumination is also conceivable.

[0013] The luminaire also includes a support profile. This support profile is preferably designed to hold the light source. Typically, the support profile includes interfaces where mounting elements are operatively connected. These mounting elements can be, for example, a rope, a chain, and/or a cable. The support profile allows for simpler and more flexible mounting of the luminaire. Depending on the application, the support profile can consist of a single element or several individual elements. For example, several semicircular support profile sections, such as two semicircular support profile sections, can be used to form the support profile.

[0014] The luminaire further comprises a transparent light-directing element that is at least partially translucent from the light source. In particular, the light-directing element enables more targeted light distribution and also simplifies manufacturing. The light-directing element at least partially surrounds the light source. This arrangement allows the light from the light source to be directed more efficiently and precisely, minimizing stray light and producing more focused illumination. The light-directing element can preferably be supported by the mounting profile. This allows for a more compact design of the luminaire.

[0015] The light-directing element is also designed to focus the light to create a beam of light directed in a specific direction. The direction of light indicates the preferred direction in which the beam of light is directed. Overall, the luminaire can thus provide more targeted illumination.

[0016] Furthermore, the light-directing element is designed to block light from directions outside the emitted light cone. This light blocking ensures that light in unwanted directions is specifically reduced to a minimum or completely eliminated, thus enabling a glare-free view of the luminaire and improving user comfort.

[0017] The light-guiding element thus offers the overall advantage of focusing light within the exit cone and simultaneously blocking light outside the exit cone. In preferred embodiments, this is achieved exclusively by refraction of light at rounded optical surfaces in a light-guiding region of the light-guiding element.

[0018] In one embodiment, the light focusing results in an approximately uniform light distribution or a batwing light distribution within the emitted light cone. A batwing light distribution enables a uniform light distribution without significant differences in brightness. Depending on the application, the batwing light distribution can encompass an emitted light cone with a beam angle between 20° and 65°. Overall, this ensures greater application flexibility.

[0019] To minimize light loss, the light source is at least partially surrounded by a translucent space. Furthermore, this translucent space can be at least partially enclosed by the light-directing element. A medium that specifically influences the properties of the light can be placed within this space. This medium could, for example, be air with a refractive index of 1.

[0020] In one embodiment, the light-guiding body has a light-entry surface facing the light source, at least in one light-guiding region. This light-entry surface acts as a refractive surface. For example, light from the light source first passes through the optical space and is then refracted at the light-entry surface. In addition to the light-entry surface, the light-guiding body also has a light-emission surface in the light-guiding region. This light-emission surface also acts as a refractive surface. For example, light that has been refracted at the light-entry surface is refracted again at the light-emission surface. The light-guiding region is defined by the spatial area of the light-guiding body in which the light is directed and distributed to achieve the desired illumination effect. The light-guiding region includes the optical components, in particular rounded optical surfaces for light refraction, which are used to direct the light from the light source in the desired direction of emission.

[0021] For optimized light refraction at the light-entry surface, the light-entry surface, when viewed in cross-section through the light-guiding body, has a concave contour, particularly in the direction of radiation. This concave contour allows for more precise control of the light distribution and can potentially reduce scattering losses. Specifically, the concave contour extends across the entire light-entry surface, at least within the light-guiding area of the light-guiding body.

[0022] The precision of light refraction can be further increased by having the concave contour of the light-entry surface, relative to an imaginary circular contour, exhibit a flattening in at least one lateral region of the light-guiding area. This allows for a local thickening of the light-guiding body and a converging lens effect, resulting in improved focusing of the exit light cone. The flattening has a lesser curvature than that of the imaginary circular contour in the light-guiding area.

[0023] Preferably, the light-emitting surface, viewed in cross-section through the light-guiding body, has a convex contour, particularly in the direction of radiation. The convex contour is preferably circular, and in particular a completely circular contour, extending over the entire light-emitting surface. Such a geometry serves to achieve, at least in a lateral region of the light-guiding area, the local thickening of the light-guiding body and the converging lens effect for improved focusing of the emitted light cone. Furthermore, such a geometry can be manufactured more easily.

[0024] In one embodiment, the light-guiding element acts as a converging lens in at least one lateral light-guiding area and, in particular, in two lateral light-guiding areas. Additionally, the light-guiding element can act as a diverging lens in a central light-guiding area. This combination enables targeted light dispersion in the central light-guiding area and targeted light focusing in the lateral light-guiding area(s). Overall, a uniform distribution of light is achieved between the central light-guiding area and the at least one lateral light-guiding area.

[0025] A simpler manufacturing process for a light-directing element can be achieved if the light-intake and light-outtake surfaces are rounded optical refraction surfaces, at least in the light-directing area. Specifically, the light-intake and light-outtake surfaces are completely rounded optical refraction surfaces. The optically rounded refraction surfaces also offer the advantage of glare-free light distribution, meaning a glare-free view of the luminaire from an angle outside the emitted light cone.

[0026] In comparison to state-of-the-art luminaires, the light entry surface and the light exit surface can be shaped without or free of prismatic refraction surfaces, thus enabling more efficient light distribution, especially with less stray light, and also a simpler manufacture of the light-guiding body.

[0027] In some embodiments, the luminaire or light-directing element can be shaped without or free of diaphragms for light blocking. Alternatively or additionally, the light-directing element can be shaped without or free of reflectively coated surfaces for light blocking. This simplifies the luminaire's design and maximizes light utilization, or minimizes light loss.

[0028] In one embodiment, the light-guiding element comprises or consists of transparent plastic, in particular polycarbonate or PMMA. For example, the polycarbonate may have a refractive index of n=1.585 and an angle of total internal reflection of 39°, or PMMA may have a refractive index of n=1.49 and an angle of total internal reflection of 42°. Alternatively, the light-guiding element comprises or consists of glass, in particular crown glass or fused silica. For example, the crown glass may have a refractive index in the range of n=1.46 to n=1.65 and an angle of total internal reflection in the range of 43° to 37°, or fused silica may have a refractive index of n=1.54 and an angle of total internal reflection of 40.5°.

[0029] A key advantage of the luminaire according to the invention is its versatility in design. The luminaire can be toroidal, cylindrical, or spherical. A toroidal luminaire can be formed from semicircular light-guiding elements and semicircular support profiles. The light source can be an arrangement of several LEDs. In this embodiment, the semicircular support profiles and semicircular light-guiding elements can be offset from each other by half a semicircle, in particular by 90°.

[0030] To allow for mounting between the light-guiding element and the support profile, the light-guiding element has a recess in a mounting area to receive the support profile. This mounting area is preferably located above the light source. The support profile can be positioned in the recess of the light-guiding element. This allows for a more compact design of the luminaire.

[0031] A more stable and reliable connection between the light-guiding element and the support profile can be achieved if the light-guiding element forms a positive fit with the support profile. In particular, the positive fit can be formed on part of the mounting area of the light-guiding element, especially with the recess. This eliminates the need for additional fasteners. A sealing element can preferably be arranged between the light-guiding element and the support profile. This can provide protection against the ingress of dust and dirt.

[0032] In one embodiment, the support profile for backscattering light reflected from the light-entry surface can include a scattering element. In particular, the scattering element can be arranged laterally next to the light source. When light strikes the light-entry surface, a portion of the light, e.g., 10%, can be reflected back towards the light source. The scattering element serves to backscatter the reflected light in the direction of radiation. Specifically, the scattering element can backscatter the light reflected from the light-entry surface in a Lambertian light distribution. This light suppression can be achieved by focusing primary light from the light source within the light-directing element and by total internal reflection of backscattered light within the light-directing element.

[0033] Another aspect of the present disclosure relates to a method for manufacturing a light-guiding body, in particular a light-guiding body as described herein.

[0034] The method for manufacturing a light-guiding body includes the process step of providing a transparent body. The transparent light-guiding body can be cylindrical, spherical, or semicircular. In particular, a transparent body with a convex light-emitting surface can be provided.

[0035] Furthermore, the process for manufacturing a light-guiding body includes the step of creating a recess in the transparent body. Depending on the application, this recess can be created using a milling cutter or a combination of a milling cutter and drill. Milling allows for more precise machining of the body, enabling the creation of more accurate geometries and surface finishes. Compared to other manufacturing methods such as injection molding or precision grinding, milling is a straightforward process that can be set up and executed quickly. Drilling allows for rotationally symmetrical machining of the body. The recess can be designed as a hole, a bore, or a groove. In particular, the recess can have a concave entry surface for the transparent body. For example, the recess can be formed from two partial recesses. The first partial recess can be formed as a groove or bore. Subsequently, a second partial recess can be created adjacent to the first partial recess. The first partial recess can be milled using a milling cutter. The second partial recess can be created using a rotationally symmetrical diamond milling cutter. This allows the concave light-entry surface to be produced with conventional and straightforward manufacturing processes and with higher precision.

[0036] Preferably, creating the recess involves milling a groove or drilling a hole in the transparent body. Alternatively or additionally, creating the recess involves milling a concave light-entry surface for the transparent body using a rotationally symmetrical diamond milling cutter.

[0037] Another aspect of the present disclosure relates to a method for manufacturing a lamp, in particular a lamp as described herein.

[0038] The method for manufacturing a luminaire comprises providing semicircular transparent light-guiding elements, in particular semicircular transparent light-guiding elements as described herein. For example, two semicircular transparent light-guiding elements may be provided. A different number of semicircular transparent light-guiding elements is conceivable.

[0039] The process for manufacturing a luminaire further includes the step of providing semicircular support profiles. For example, two semicircular support profiles can be provided. A different number of semicircular support profiles is conceivable. A diffuser can be arranged on the support profiles. Furthermore, a semicircular LED array can be attached to the support profiles.

[0040] The method for manufacturing a luminaire further comprises the process step of inserting the semicircular support profiles into the semicircular transparent light-guiding bodies. The semicircular support profiles are inserted into the recess of the semicircular transparent light-guiding bodies. For example, a semicircular support profile can be inserted into the semicircular transparent light-guiding body in such a way that the semicircular support profile is arranged along the entire length of the recess along the light-guiding body, in particular 180° of the semicircular light-guiding body. The semicircular support profiles form a positive fit at the mounting area of the semicircular transparent light-guiding bodies. Preferably, a sealing element can be installed between the support profiles and the light-guiding bodies.

[0041] The next step in the process for manufacturing a luminaire is to connect the semicircular light-guiding elements with the inserted semicircular support profiles. The semicircular light-guiding elements with the inserted semicircular support profiles are brought together. Once brought together, the inserted semicircular support profiles can be connected using a connecting element.

[0042] To transfer forces between the semicircular support profiles, the semicircular light-guiding elements are connected to inserted semicircular support profiles using a tension element, in particular a coil spring. Tension elements enable a tighter connection of the semicircular support profiles, minimizing mechanical stresses.

[0043] An even stronger and more stable connection can be achieved if, after connecting the semi-circular light-guiding bodies with inserted semi-circular support profiles, the semi-circular support profiles are shifted by half a partial circle, in particular by 90°.

[0044] The described embodiments of the luminaire can serve to carry out the methods according to the invention. The previously described embodiments of the luminaire also disclose correspondingly configured embodiments of the method for manufacturing a light-guiding element or the method for manufacturing a luminaire. The listed process steps are not exhaustive and can also be carried out (if appropriate) in a different sequence.

BRIEF DESCRIPTION OF THE FIGURES

[0045] Aspects of the invention are explained in more detail with reference to the exemplary embodiments shown in the following figures and the accompanying description. The figures show:

Fig. 1

A cross-sectional view of an embodiment of a lamp according to the invention;

Fig. 2

an exemplary embodiment of a light distribution curve of a luminaire according to the invention;

Fig. 3

a torus-shaped embodiment of a lamp according to the invention in a perspective view;

Fig. 4

the lamp according to the invention from Fig. 3 in an exploded view;

Fig. 5

a cylindrical embodiment of a lamp according to the invention in one embodiment in a perspective view;

Fig. 6

a detailed view of Figure 5;

Fig. 7

A spherical embodiment of a lamp according to the invention in one embodiment in a perspective view.

[0046] The following are examples of the lamp and its components as disclosed, illustrated with reference to the figures.

[0047] Figure 1 shows a cross-sectional view of a luminaire 1 according to the disclosure. The cross-sectional view of the luminaire 1 according to Figure 1 represents a cross-sectional view of a torus-shaped, spherical or cylindrical luminaire. Figure 2 shows an example of a light distribution curve of the luminaire 1 according to the invention.

[0048] The luminaire 1 includes a light source 2. The light source 2 can be a single LED 2 or an LED array 2. In particular, the light source 2 can be mounted on a support. The light source 2 can be switched on or off, but continuous illumination is also conceivable.

[0049] The luminaire 1 further comprises a support profile 3. The support profile 3 is designed to hold the light source 2. Depending on the embodiment, the support profile 3 can be formed from a single element or from several individual elements. The support profile 3 also includes a diffuser 6, which is arranged laterally next to the light source 2.

[0050] The luminaire 1 further comprises a transparent light-directing body 5, which is at least translucent to the light source 2. The light emitted by the light source 2 can be distributed more precisely by means of the light-directing body 5. The light-directing body 5 surrounds at least partially the light source 2, particularly to minimize stray light. The light-directing body 5 can preferably be supported by the mounting profile 2.

[0051] The light-guiding body 5 can be used to focus and diffuse the light. In particular, the light-guiding body 5 is designed to focus the light to produce an emitted cone of light in a specific direction.

[0052] Figure 2 shows an example of the effect of light control, in particular light focusing. A light distribution curve shows, in particular, a symmetrical light distribution of the emitted light cone in the direction of radiation (here, downwards). Asymmetrical light distributions and other radiation directions are also conceivable. The center of the light distribution curve corresponds to the position of the light source 2. Light control, in particular light focusing, preferably results in a batwing light distribution within the emitted light cone. Light focusing can be described by the opening angle of the light emitted cone or by the emission angle. In Figure 2, the emission angle is chosen to be 65° as an example. Depending on the application, the emission angle can be selected, for example, within a range of 20° to 65°.

[0053] Furthermore, the light-directing element 5 is designed to block light from directions outside the emitted light cone. This ensures that light in unwanted directions is selectively reduced to a minimum or completely avoided. This allows for a glare-free view of the luminaire 1.

[0054] The light source 2 is at least partially surrounded by a translucent space 7. In particular, the translucent space 7 is at least partially enclosed by the light-guiding body 5. Air with a refractive index of 1 can be arranged in the translucent space 7 to selectively influence properties of the light from the light source 2. Other media are also conceivable.

[0055] The light-guiding body 5 can be divided into a light-guiding area 5a, a light-blocking area 5b, and a mounting area 5c. The light-guiding area 5a is defined by the spatial area of the light-guiding body 5 in which the light is directed and distributed to achieve the desired lighting effect. For this purpose, the light-guiding area 5a comprises the optical components 8, 9, in particular rounded optical surfaces 8, 9 (e.g., interfaces 8, 9) for light refraction, which are used to direct the light from the light source in the desired direction of emission. The light-blocking area 5b is defined by the spatial area of the light-guiding body 5 in which a glare-free view of the luminaire 1 is achieved from a viewing angle outside the emitted light cone. The light blocking area 5b comprises the optical components used to minimize or completely prevent light from the light source 2 from reaching outside the light output cone. The mounting area 5c is defined by the spatial area of the light-guiding body 5 in which the light-guiding body 5 is supported or held.

[0056] The light-guiding body 5 has, at least in the light-guiding area 5a, an optical component in the form of a light-entry surface 8 directed towards the light source 2. The light-entry surface 8 serves as a refractive surface for light coming from the light source 2, passing through the translucent space 7, and striking the light-entry surface 8.

[0057] As can be seen in the cross-sectional view, the light-entry surface 8 has a concave contour in the direction of radiation, extending over the entire light-entry surface. With respect to a circular reference contour, the concave contour exhibits a flattening in at least one lateral region or lateral part of the light-guiding region 5a. A stronger bend or a smaller radius of curvature is present in a central region or central part of the light-guiding region 5a.

[0058] In addition to the light-intake surface 8, the light-guiding body 5 has, at least in the light-guiding area 5a, a light-emission surface 9, which also serves as a refractive surface. Light that has been refracted by the intake light surface 8 can be refracted again at the light-emission surface 9. In the direction of radiation, the light-emission surface 9 has a convex contour. The convex contour of the luminaire in Figure 1 is a circular contour that can extend over the entire light-emission surface 9.

[0059] For improved light focusing, the luminaire 1 acts as a converging lens in at least one lateral part of the light-guiding area 5a (here in the area of the flattened sections) and as a diverging lens in the central part of the light-guiding area 5a (here in the area of the stronger bend). The converging lens effect is evident in the convergently refracted (here downwards) light rays L1 in at least one lateral part of the light-guiding area 5a. The diverging lens effect is evident in the divergently refracted (here slightly laterally deflected) light ray L2 in at least one lateral part of the light-guiding area 5a.

[0060] The light-intake surface 8 and the light-emission surface 9 are, at least in the light-guiding area 5a, rounded optical refraction surfaces 8, 9. The light-intake surface 8 and the light-emission surface 9 are completely rounded optical refraction surfaces. In other words, the light-intake surface 8 and the light-emission surface 9 are shaped without prismatic refraction surfaces. Optically rounded refraction surfaces are easier to manufacture. Furthermore, the light-guiding body 5 has no aperture, in particular no light-absorbing element, and no reflective coating for light blocking. Overall, the design of the luminaire 1 is simplified and the light utilization is maximized.

[0061] The light-guiding body 5 has a recess 11 in the mounting area 5c for receiving the support profile 3. The support profile 3 is thus arranged in the recess 11 of the light-guiding body 5. Additionally, a sealing element 4 can be arranged between the support profile 3 and the light-guiding body 5. This allows for a positive fit between the light-guiding body 5 and the support profile 3 in the mounting area 5c.

[0062] The light-guiding body 5 can be made of, or comprise, transparent plastic or glass. For example, the light-guiding body can be made of PMMA with a refractive index n=1.49 and an angle of total internal reflection of 42°.

[0063] Figure 1 also shows an axis A, which, depending on the embodiment, represents a mirror axis or a rotation axis.

[0064] Figure 3 shows a torus-shaped luminaire 1a. Mounting elements 10 are attached to the support profile 3 to install the luminaire 1a, for example, on a ceiling or a wall. Mounting elements 10 can include a cable and/or a rope.

[0065] Figure 4 shows the torus-shaped luminaire 1a from Figure 3 in an exploded view, particularly in an assembled state. The torus-shaped luminaire 1a has two semicircular transparent light-directing elements 5. Two semicircular support profiles 3 are also shown. A plurality of semicircular LED assemblies 2 and two semicircular diffusers 6 can each be attached to the two semicircular support profiles 3. As can be seen in Figure 4, the semicircular light-directing elements 5 and the semicircular support profiles 3 are arranged offset by 90°. Sealing elements 4 can also be arranged on the mounting area 5c between the light-directing elements 5 and the support profile 3.

[0066] Figure 5 shows an embodiment of the luminaire 1. Figure 6 is a detail view of the luminaire from Figure 5. The luminaire 1b according to Figure 5 is cylindrical. The cross-sectional view of the luminaire 1 from Figure 1 corresponds to the luminaire 1b from Figure 5 in a cross-sectional view (x-z plane). Therefore, axis A from Figure 1 corresponds to a mirror axis of the cylindrical luminaire according to Figure 5. The cylindrical luminaire 1b extends in a Y direction. Figure 6 shows a detail view of the cylindrical luminaire 1b with support profile 3, sealing element 4, light-guiding body 5, and light source 2.

[0067] Figure 7 shows an embodiment of a spherical lamp 1c. The cross-sectional view of the lamp 1 from Figure 1 also corresponds to a cross-sectional view (x-z plane) through the spherical lamp 1c in Figure 7. Therefore, the axis A in Figure 1 corresponds to an axis of rotation for the spherical lamp 1c in Figure 7.

LIST OF REFERENCE MARKS

[0068] 1, 1a, 1b, 1c Luminaire 2 Light source 3 Support profile 4 Sealing element 5 Light guiding body 5a Light guiding area 5b Light blocking area 5c Mounting area 6 Diffuser 7 Gap 8 Light entry surface 9 Light exit surface 10 Mounting element 11 Recess A Axis L1 Light beam (converging lens), convergent light beams L2 Light beam (difference lens), divergent light beams