Vehicle lamp and vehicle headlamp including the same

Abstract

The invention relates to a vehicle lamp (1) and a headlamp (23) comprising the lamp (1). The luminaire (1) comprises a light source (2), a primary optical element (3), a lens holder (4) and a secondary optical element (5). The primary optical element (3) is held between the light source (2) and the lens holder (4), and it comprises at least two parts (6). Adjacent portions (6) are separated from each other by expansion joints (7) for limiting the influence of thermal expansion of adjacent portions (6) on each other. Each portion (6) comprises at least one alignment member for individual alignment of the portion (6) with respect to at least one other portion of the luminaire (1). Both optical elements can be segmented.

Description

Technical Field

[0001] The present invention relates to vehicle lighting. More particularly, the present invention relates to a lamp having an improved optical element that is less affected by heat. Background Art

[0002] LED headlamps or headlamp modules in the prior art generally include a PCB with an LED attached to a heat sink, primary optics, secondary optics (often referred to simply as a lens or projection lens), and supporting elements such as a housing and a lens holder. The primary optics is closer to the LED and pre-processes the light, and then the secondary optics directs the light in a desired pattern onto the road ahead. Examples of such LED headlamps are disclosed in document US11028987 B2 or document WO2022242783 A1. The latter document also discloses an assembly kit and method for a headlamp module.

[0003] Nowadays, optical elements are usually made of transparent polymers such as polycarbonate or PMMA, because they are lighter and easier to manufacture than optics made of glass. However, one disadvantage of polymer optics is its thermal expansion. Light sources, even LEDs, generate a lot of heat during their operation, and since the primary optics are very close to the light source, they will be heated. The optical element thus thermally expands, and the lighting pattern provided by the lamp is slightly distorted due to this expansion. This distortion is more obvious in the details of the lighting pattern such as the light and dark cut-off line. For more complex headlight optics, this distortion becomes more significant. Therefore, the thermal expansion of optical elements and its undesirable influence on the optical function of the element is one of the obstacles to the development of more complex optical elements and lighting modules, especially for use in vehicle headlights. More complex elements and modules can, for example, improve the design, increase energy efficiency, save space, etc.

[0004] It would therefore be desirable to provide a method of reducing the effects of thermal expansion on optical components in vehicle lamps. Summary of the invention

[0005] The disadvantages of the solutions known in the prior art are to some extent eliminated by a vehicle lamp comprising at least one light source, a primary optical element, a lens holder and a secondary optical element. The primary optical element is held between the light source and the lens holder. The light source is preferably an LED light source. All LEDs then preferably share a common PCB. The primary optical element is closer to the light source than the secondary optical element and receives light from the light source, while the secondary optical element receives light from the primary optical element. The lens holder may be one or more components that carry one or both of the optical elements. Preferably, one lens holder (which may however be composed of multiple parts) carries, supports, pushes onto or otherwise holds the two optical elements and attaches them to another part of the lamp, for example to the light source.

[0006] The primary optical element comprises at least two parts, and it also comprises at least one expansion joint. An expansion joint is a component that holds the parts together while mitigating the effects of thermal expansion of adjacent parts on each other. The parts are preferably held together at least to some extent so that they can be easily assembled all at once, e.g. the entire primary optical element is clamped and mounted to a light source at once. However, in order to limit the effects of thermal expansion, the joint allows some movement between the parts.

[0007] Since polymers used for optics generally expand when their temperature increases, if one part of the primary optical element is heated, it will increase its volume or area. If the parts are fixedly connected to each other (by screws, gluing, welding, etc.), the expansion of one part will necessarily press on the adjacent parts and will move these parts. Since it is important in vehicle lamps to have the optical element centered with respect to the light source, such movement caused by expansion is undesirable.

[0008] Thus, adjacent parts of the primary optical element are separated from each other by at least one expansion joint. Furthermore, each part comprises at least one alignment member for individual alignment of the part relative to at least one other part of the luminaire. The alignment member may in particular be a pin or other protrusion, or a hole or recess. The use of pins and oval holes for aligning luminaire components is known in the art. For the present invention, an important aspect is that each part has at least one alignment member of its own. Thus, each part is self-aligning / centering. That is, the alignment of one part is at least to some extent independent of the other parts. In combination with the expansion joint, this means that the parts are individually centered and are not affected (or at least less affected) by the expansion of the other parts. As a result, temperature changes have a much smaller impact on the function of the luminaire or the resulting lighting pattern provided by the luminaire (e.g., if the luminaire is a headlamp, the resulting lighting pattern provided on the road ahead).

[0009] For example, the coefficient of thermal expansion of polycarbonate (PC) is 0.065mm / m°C. This means that an optic that is 150mm long (which is roughly the standard size of a headlight optic) and is heated by 30°C by an LED light source (when it reaches its standard operating temperature of 50°C) will expand by about 0.3mm. This expansion will cause the optic to shift relative to the light source, which will distort the lighting pattern of the lamp on the road. By isolating the expansion to individual segments, if there are four segments of the same size, each segment will expand by less than 0.1mm. Movement of one part of the optic by less than a tenth of a millimeter will generally not significantly affect the performance of the lamp.

[0010] The above exemplary calculation is quite simplified because it assumes, for example, that the optical element is heated uniformly and that the parts have the same size, but it shows how the division of the primary optical element can help to reduce the overall thermal deformation of the primary optical element and therefore can help to maintain the lighting performance of the luminaire regardless of the temperature of the LEDs and the optical element.

[0011] The luminaire according to the invention may in particular be an exterior luminaire, such as a headlamp or taillight or a module therefor. It may also be an illuminated front grille or bumper or a similar lighting device. However, it is also possible to use the luminaire in the interior, even though distortions of the lighting pattern of the luminaire due to thermal expansion are much less noticeable in the interior.

[0012] The optical element can be made of a polymer material such as PMMA or polycarbonate. The lens holder and / or the primary optical element itself preferably keeps the primary optical element at a specified distance from the light source, or in particular from its LED sub-source. For example, the lens holder can push the element toward the light source, and there is a protrusion on the back side of the element, which serves as a stopper for backward movement and maintains the minimum distance between the optical part of the primary optical element and the LED. These stops can be supported against the surface of the light source (e.g., PCB). The surface does not include other components (e.g., parts soldered to the PCB) at the position corresponding to the stopper. There can also be a recess complementary to the stopper shape provided on the light source. Then, the stopper can limit the distance between the primary optical element and the light source, and can also help the two components to be centered.

[0013] Thus, the parts are sub-parts of the primary optical element, which are separated from each other and at the same time held together by the expansion joint(s). The functionality of the expansion joints allowing limiting the effects of thermal expansion may be provided by their material (e.g. by using a more flexible / elastic material than the material of the parts), the shape of the material (e.g. making the joints thinner, porous, perforated or curved so that they are more flexible / elastic than the parts), their construction (e.g. by providing a plurality of mutually telescopic or otherwise linearly movable parts of the joint), etc. Thus, the expansion effects to be limited are mainly the forces / pressures / tensions caused by the expansion of one part acting on the adjacent part(s) and the corresponding movement of these adjacent part(s).

[0014] At least one other part of the luminaire is a counterpart for the alignment of these parts, which can be any component, such as a lens holder, a housing or frame of the luminaire, or a light source. It is preferred to use a counterpart made of a material having a smaller coefficient of thermal expansion than the coefficient of thermal expansion of the primary optical section. Therefore, the light source is a preferred counterpart for alignment because it often contains a PCB. Standard PCB materials such as fiberglass or other composite materials have a lower coefficient of thermal expansion and can therefore keep these parts aligned as required. However, it is also possible to make a lens holder, for example, from fiberglass, and then use it as an alignment counterpart. The counterpart can include complementary alignment members, for example, if there are pins on the optical element, the counterpart can include holes, and vice versa.

[0015] Two adjacent sections can be connected with multiple expansion joints. The sections can all be in a row or a column, i.e. there are two end sections that have a single adjacent section on one of their sides and any possible further sections between these two end sections and have adjacent sections on both sides. It is also possible to have multiple rows or columns of sections and so on. For example, four sections can be two rows and two columns, i.e. they can form a square array. The rows or columns of the sections can then have a different number of sections, for example there can be four rows of sections, the first and the last row each having two sections next to each other, and the second and the third row having only one section. Any configuration with any number of sections can be used in the proposed luminaire.

[0016] Preferably, parts of the primary optical element and at least one expansion joint are made from a single piece of material. This significantly simplifies the manufacture of the element. It can, for example, be injection molded in a single mold. Thus, there is no need to provide multiple molds to assemble the primary optical element from multiple pieces, etc.

[0017] Preferably, each expansion joint is formed as a curved section of the primary optical element and / or as a section of the primary optical element with a reduced cross section. This form of joint can be combined with manufacturing the entire element from one piece of material. As a result, the entire primary optical element is cheaper, lighter, less prone to wear, etc.

[0018] Thus, each expansion joint may have a cross section including three bends, wherein one of the bends located between two other bends has a curvature in the opposite direction to the other two bends. Thus, the joint may have a shape such as a rounded letter M or W. Such a waveform with multiple different directions of curvature, i.e., the center of curvature is on different sides of the cross section, may allow each part to have a greater range of motion without affecting the other parts. With multiple bends, i.e., at least two bends, each of the bends also bends less during thermal expansion and is therefore less likely to break over time.

[0019] The lens holder may press against the primary optical element at each part. For example, the lens holder may have at least one pressing protrusion for each part, and via this protrusion, the lens holder forces the primary optical element towards the light source. Thus, the optical element is prevented from bending or detaching from the light source. Since the lens holder presses against each part, the individual alignment or positioning of these parts is further supported.

[0020] The primary optical element may have a substantially planar light entrance surface, and / or the secondary optical element may have a substantially planar light exit surface. The shape of these surfaces may have an aesthetic effect, but may also have a technical impact. For example, a flat entrance surface allows the primary optical element to be closer to the light source, and a substantially flat surface (e.g., a flat surface with micro-optics) may generally result in a smaller luminaire with the same lighting function.

[0021] The entrance and exit surfaces of both optical elements can generally have almost any shape, for example, can be protruding, can be flat, can have a continuous free-form shape, can have micro-optics, etc.

[0022] The light source may comprise a printed circuit board with LED sub-sources and a heat sink.The light source may then comprise complementary alignment means for the alignment means of the primary optical element, for example it may comprise a hole through the PCB into the heat sink.

[0023] Each part of the primary optical element may comprise at least one primary segment, wherein each primary segment is individually shaped and oriented for processing and directing the light from the light source. Thus, the primary segment is the part of the element that provides the desired optical function. Each sub-source of the light source may then have its own segment that processes and directs the light individually for that sub-source. This allows much more complex lighting functions to be obtained than when the optical element has an optical surface common to all sub-sources.

[0024] The secondary optical element may also be segmented, i.e. it may comprise a plurality of secondary segments, wherein each secondary segment is aligned with a corresponding primary segment. Each secondary segment is individually shaped and oriented for processing and directing light from a corresponding primary segment. Thus, each secondary segment receives light from a corresponding primary segment and directs it to a prescribed position to be illuminated by this segment. Thus, the primary segment and the secondary segment cooperate to process light from the light source, in particular light from a corresponding sub-source of the light source, and direct the processed light to a specific portion of the road ahead. The processing, for example, comprises homogenizing and stretching the light beam over a prescribed area, for example from a first distance in front of the vehicle to a second distance in front of the vehicle.

[0025] Segmenting both the primary and secondary optical elements increases the versatility of the luminaire. By shaping the segments, i.e., by shaping the entrance and exit surfaces of both types of segments, the light can be shaped and directed as needed. The shape of the exit surface of the secondary segment can be seen from the outside, so design considerations may also affect its shape. For each corresponding primary segment and secondary segment, the four surfaces can be designed together by computer simulation. The simulation can be input with some parameters, such as the position (area) that should be illuminated by a specific segment, and the shapes of all four surfaces can be output. Other corresponding segments can be designed independently in the same way (i.e., each submodule as defined below can be designed separately, and then their segments are placed at a common optical element).

[0026] The lens holder may include a shielding grid for separating the light beams passing between the corresponding primary and secondary sections. Thus, the lens holder is located between the elements and the grid ensures that the light beams from different primary sections do not influence each other and do not reach any other secondary section than the corresponding secondary section. Thus, the grid further ensures that the submodules do not influence each other - light emitted from one submodule does not penetrate into another.

[0027] The shielding grille may have at least one roughened or matte surface for reducing glare. Glare that occurs on the smooth surface of the grille may be a source of localized brightness increases in the resulting illumination pattern. This will reduce uniformity and may be distracting to the driver or other vehicle drivers. Therefore, some or all surfaces may be treated or produced so that they are less reflective. The selection of surfaces for such treatment, i.e., roughening or matting, may also be computer simulated. For example, a simulation may show which surfaces reflect a lot of light, thereby producing inhomogeneities, and these selected surfaces may then be treated. The treatment may include changing the mold used to make the lens holder, for example, roughening its corresponding walls; it may include coating the surface with a low-reflection coating; it may include grinding / polishing the surface, etc. For simplicity, the entire lens holder may, for example, be coated so that there is no need to identify surfaces that are prone to glare.

[0028] Each primary segment and its corresponding secondary segment may have a corresponding photon source on the light source, wherein mutually corresponding primary segments, secondary segments and sub-sources form a lighting submodule for illuminating a given illuminated area in front of the luminaire. The corresponding channel in the shielding grille may also be considered as part of each submodule. The submodules are essentially independent in their lighting function, e.g. each submodule can be directed independently of the other submodules, but they share optical elements and light sources. Thus, the luminaire is very versatile (each submodule provides its own lighting, so a plurality of submodules can be combined into a luminaire providing any desired lighting pattern designed by a skilled person), but is also relatively cheap and easy to assemble, since the number of parts of the luminaire is much smaller than in the case where the submodules do not share optical elements. Preferably there are at least five, more preferably at least ten submodules. This number of submodules can provide reasonable lighting, e.g. for low beam functions etc., and can more fully exploit the advantages of the invention (improved resistance to thermal expansion, easier assembly etc.).

[0029] The light output directions of at least some of the submodules (e.g., given by a vector connecting the center of the secondary section with the center of the illuminated area on the road or on a vertical surface in front of the luminaire) may be non-parallel to each other, wherein the arrangement of the submodules on the luminaire is different from the arrangement of their corresponding illuminated areas.

[0030] This means that when the luminaire is viewed from the front, the arrangement of the submodules is different, and when the illuminated vertical surface is viewed from the rear or the illuminated road is viewed from above, the arrangement of the corresponding illuminated areas is also different. These arrangements define how the submodules / areas are positioned relative to each other. For example, it defines which submodule / area is adjacent to which, how far apart they are from each other, etc. For example, the arrangement of the submodules can be that they are in a single row oriented vertically, horizontally or diagonally. Or they can be in the form of a grid with a specific number of rows and columns, each with a specific number of sub-segments. The arrangement of the areas, especially for headlamps, is given to some extent by legal requirements. For example, it is given how bright the illumination pattern of the low beam must be at a specific distance from the car. It is known that for right-hand traffic, the right side is illuminated more (to illuminate traffic signs), while the left side is illuminated less (not to dazzle oncoming traffic). Therefore, when the submodules of the luminaire have an arbitrary arrangement, the present invention makes it possible to obtain prescribed road lighting for a given light function. The arrangement of the submodules can be given, for example, by the design requirements, technical requirements, etc. of the customer.

[0031] On vehicle lamps known in the prior art, the arrangement of the submodules (e.g., LEDs of a matrix headlamp with primary optics and projection lens - known headlamps do not have submodules with the same parts and configuration as described above) is identical to the arrangement of the illuminated areas. Thus, the submodules are in a substantially vertical row, and the leftmost submodule illuminates the leftmost portion of the road, the submodule next to it illuminates the adjacent portion of the road, and so on, up to the rightmost submodule that illuminates the rightmost portion of the road (or more precisely, the rightmost submodule often illuminates the area next to the road on the right side, rather than the road itself).

[0032] In the prior art, it is not possible to have different submodule arrangements while maintaining the desired lighting pattern on the road. The submodules would have to be completely separate, i.e. they would be separate modules, with separate and therefore expensive assembly, and with very demanding alignment. One reason is that the individual pointing / orientation of the submodules in the present invention is relatively sensitive to thermal expansion. Since the light beams are rearranged on their way from the secondary segments to the corresponding illuminated areas, the movement of the primary segments relative to the photon source can easily distort the lighting pattern. Therefore, the improved resistance to thermal expansion achieved by the individually aligned parts connected by expansion joints is particularly important for luminaires with submodules arranged differently from the illuminated areas.

[0033] For at least some of the submodules, the arrangement of the submodules on the luminaire can be rotated relative to the arrangement of their corresponding illuminated areas. Some of the submodules can be arranged vertically one above the other, and when the lamp illuminates a flat vertical surface from a predetermined distance, the corresponding illuminated areas of the vertically arranged submodules are then arranged at substantially the same height on the surface.

[0034] Substantially the same height means that there may be, for example, one vertical line through all areas. In layman's terms, this simply means that the road is illuminated from left to right (which is required), even if not all submodules are arranged from left to right. The submodules may be arranged in rows, for example at least five rows, each row having 1 to 3 submodules. Each row is at a different height, i.e. they are one above the other. This may enable the creation of a headlamp with modules that appear as a substantially vertical bright line, a desired appearance that is difficult to achieve with lamps known in the art.

[0035] The predetermined distance is usually 25 metres - at this distance the headlamp lighting pattern should comply with the legal requirements, that is, it should look essentially the same as the pattern on the road during actual use of the headlamp.

[0036] The submodules can be arranged in the luminaire at least partly based on their operating temperature, i.e. based on how hot they or their subsources are expected to get when used for a longer period of time (e.g., half an hour). The operating temperature can be, for example, the temperature reached by the corresponding subsource. Some submodules with higher operating temperatures can then be separated from each other by at least one submodule with a lower operating temperature. At the same time, the illuminated areas of the submodules with higher operating temperatures are directly adjacent or overlap.

[0037] Typically, the middle of the road needs to be the brightest, while the lighting pattern is darker the closer to the side and farther away from the vehicle. The submodules pointing to the middle area can therefore provide brighter lighting, which naturally means that they generate more heat and therefore have a higher operating temperature. The illuminated areas of these brighter submodules are next to each other or even overlap to make these areas brighter as needed. In the prior art, these hotter submodules are next to each other because the arrangement of the submodules or sub-sources is the same as the arrangement of the illuminated areas, as described above. On the other hand, the present invention can have different submodule arrangements. Therefore, it is advantageous to place the hotter submodules away from each other so that their heat can be dissipated more effectively. The cooler submodules can then be adjacent to the hotter submodules. The temperature on the light source is more uniform, and the maximum temperature is lower than when the hottest submodules are directly next to each other.

[0038] The disadvantages of the solutions known from the prior art are also eliminated to some extent by a vehicle headlamp comprising a plurality of lighting modules, wherein at least two of the lighting modules are vehicle lamps according to the invention. For example, a headlamp having a plurality of modules, each module having a substantially vertical submodule arrangement as described in more detail above, may be particularly advantageous, since it provides the vehicle with a very attractive and novel appearance. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The present invention is further described by way of exemplary embodiments of the present invention described with reference to the accompanying drawings, in which:

[0040] Figure 1 A perspective view of the primary optics from an exemplary vehicle lamp according to the invention is shown, wherein the division of the primary optics into four parts separated by an expansion joint and its division into fifteen optical primary segments can be seen.

[0041] Figure 2 Shown from Figure 1 Side view of a primary optical element, in which a cross section of the expansion joint and the alignment pins for centering the parts of the primary optical element can be seen.

[0042] Figure 3 Shows the Figure 2 Detail of one of the expansion joints. A cross section of the joint with its three bends can be seen.

[0043] Figure 4 Shows the Figures 1 to 3 It can be seen that at least some of the primary segments extend between the parts over the opening and that each telescopic joint has two arms delimiting this opening from the left and right.

[0044] Figure 5 An exploded view of an exemplary vehicle lamp is shown, the vehicle lamp including a heat sink, a PCB, a primary optic, a lens holder, and a secondary optic.

[0045] Figure 6 Shows the Figure 5 Rear view of a lens holder of FIG. 1 , wherein the lens holder includes a shielding grid that separates a light beam originating from an LED on a PCB and traveling between two optical elements.

[0046] Figure 7 Shows the Figure 6 Side view of a lens holder.

[0047] Figure 8 A schematic perspective view of a secondary optical element is shown, wherein fifteen optical secondary segments with different shapes and inclinations can be seen in the figure.

[0048] Fig. 9 Shows the Figure 8 Side view of the secondary optical element.

[0049] Fig.10Schematically shown are front views of two headlamps, each comprising four exemplary vehicle lamps according to the invention, wherein each of the vehicle lamps has a substantially vertical arrangement of submodules and thus has a width that is much smaller than its height.

[0050] Fig.11 Shows the Figure 5 A perspective view of a partially assembled luminaire of FIG. 1 , wherein there is a mounting support with three pins and a heat sink mounted on the mounting support.

[0051] Fig.12 Schematically shows the Figure 5 Front view of a partially mounted luminaire in which there is a mounting support with three pins and the heat sink, PCB and primary optical element are mounted on the mounting support and centered by the pins of the mounting support.

[0052] Fig.13 Shows the Fig.12 Another schematic diagram of a partially mounted luminaire in which a lens holder is also mounted on the mounting support.

[0053] Fig.14 A schematic illustration of one submodule of an exemplary luminaire according to the present invention and its illuminated area projected onto a vertical surface placed in front of the luminaire is shown.

[0054] Fig.15 A schematic diagram depicting the arrangement of illuminated areas of various submodules of an exemplary luminaire is shown.

[0055] FIG. 16 shows two schematic illustrations of the arrangement of submodules of an exemplary luminaire, wherein Fig.16A shows an ordered vertical arrangement, and Fig. 16B A vertical arrangement of submodules is shown, where the three submodules with the highest expected temperatures are separated from each other by several cooler submodules. Fig.15 As can be seen in FIG16 , the three submodules illuminate overlapping areas, so it is obvious that their beams cross the beams of the cooler submodules. The two diagrams in FIG16 also schematically show the temperatures of the submodules along the luminaire to illustrate the effect of rearrangement of the submodules on the overall temperature.

[0056] Fig.17 Shows the Fig.15 Illustration of .

[0057] FIG. 18 shows two further schematic illustrations of the arrangement of submodules of an exemplary luminaire, wherein Fig.18A In the example, the submodules are arranged in a circle and in Fig.18B In the embodiment, the submodules are arranged in a V shape. DETAILED DESCRIPTION

[0058] The present invention will be further described by means of exemplary embodiments with reference to the accompanying drawings.

[0059] According to the first exemplary embodiment, the vehicle lamp 1 is Figures 1 to 13 as well as Fig.14 , Fig.15 and Fig.16A In this embodiment, the luminaire 1 is a matrix module, and its various components can be Figure 5 The lamp 1 includes a light source 2, a primary optical element 3, a secondary optical element 5 and a lens holder 4. It also includes a housing that encloses the other components and facilitates the installation of the matrix module into the headlamp 23 (see Fig.10 , Fig.10 Two headlights 23 are shown, each having four modules; Fig.10 Only the housing of the module and the outline of the secondary optical element 5 are shown).

[0060] For the description of the lamp 1 given below, the X, Y, Z coordinate system standard of the vehicle lamp 1 is used. The X axis runs from front to back. The forward direction here is the general direction of light emitted from the lamp 1; for the headlight 23, this direction corresponds to the forward movement of the vehicle. Therefore, the backward direction is opposite to the forward direction. The Z direction is up and down, and the Y direction is from left to right.

[0061] The light source 2 comprises a heat sink 11, a printed circuit board 9 (PCB) glued to the heat sink 11, and an array of LED sub-sources 10 carried by the PCB 9 ( Figure 5 1). In the exemplary embodiment there are fifteen LEDs. The heat sink 11 comprises an aluminum plate and a plurality of aluminum fins. It also comprises several mounting and alignment features, which will be referred to below. Figures 11 to 13 Described in more detail. The PCB 9 comprises identical mounting and alignment features overlapping those of the heat sink 11, enabling complementary mounting and alignment features located on the primary optical element 3 and the lens holder 4 to pass through.

[0062] Primary Optics 3:

[0063] The primary optical element 3 is made of a transparent polymer such as PMMA or polycarbonate. It is made of one piece of material, for example by injection moulding. It has a substantially plate-shaped body and the body carries a plurality of optical segments and expansion joints 7, which will be described further below. Details of the primary optical element 3 can be found at Figures 1 to 4The primary optical element 3 is divided into four parts 6 aligned in a row and separated from each other by telescopic joints 7. The telescopic joints 7 allow adjacent parts 6 to move slightly relative to each other without influencing each other, or at least not as much as they would if the parts 6 were not separated. As a result, thermal expansion of the primary optical element 3 does not affect the element as a whole, but only the individual parts 6.

[0064] The expansion joint 7 in the depicted embodiment is produced as a thinner and curved section of the body. Figure 3 As can be seen in the figure, each of the joints has three bends 8. The side bends 8, each attached to one portion 6, are bent upwards, i.e. concave, and the middle bends 8 attaching the side bends 8 to each other are bent downwards, i.e. convex. This triple bend allows sufficient movement of the portion 6 during its thermal expansion.

[0065] Each portion 6 of the primary optical element 3 has a plurality of conical alignment pins 18 extending rearwardly from the element (see Figure 2 and Figure 3 In the depicted embodiment, there are a total of nine alignment pins 18, which can be arranged from Fig. 9 This can be inferred from the arrangement of the corresponding oval alignment holes 19 visible on the PCB 9 in FIG.

[0066] When the lamp 1 is assembled, the alignment pins 18 pass through the alignment holes 19 in the PCB 9 and the heat sink 11. The oval shape is intended to allow assembly despite any potential manufacturing inaccuracies, and the alignment members individually align each of the parts 6 relative to the PCB 9 and therefore also the LEDs in the Y and Z directions of the headlamp 23. In order to correctly align the primary optical element 3 relative to the PCB 9 and the LEDs in the X direction, a shorter pin is also provided on the back side of the primary optical element 3 (see Figure 2 ). These shorter pins have no corresponding holes, but they contact the PCB 9 with their free ends and thus keep the primary optical element 3 at a desired distance from the LED.

[0067] As a result of the above-described individual alignment of the parts 6 relative to the PCB 9, each part 6 remains centered, regardless of the expansion of the other parts 6. Each part 6 is only affected by its own expansion, which has dimensions much smaller than the entire primary optical element 3. The PCB 9 is made of a material with a very small coefficient of thermal expansion, and therefore it is suitable for keeping the primary optical element 3 properly centered.

[0068] The optical function of the primary optical element 3 is provided by the primary segments 12. Each primary segment 12 is used to pre-process the light from one of the LEDs before the secondary optical element 5 further processes the light and directs it to the road to illuminate its corresponding illuminated area 15. Each primary segment 12 has its own shape, which is designed in relation to the corresponding secondary segment 13 on the secondary optical element 5 (described further below). Each segment has an incident surface for receiving light from the corresponding LED and an exit surface for outputting light to the secondary optical element 5. The incident surface of the primary segment 12 is substantially planar, while the exit surface has a protruding pillow-like shape. In an exemplary embodiment, the shape is a free-form lens shape. Simulation software for modeling lens shapes according to desired optical functions or parameters is known in the art and can be used to obtain the shape of the optical element of the vehicle lamp 1.

[0069] As in Figure 4 This can be best seen in Figure 4 The primary optical element 3 is shown from the front, there are three parts 6 with four segments in two rows, and one part 6 with three segments in a single row. The part 6 with four segments has segments that partially overlap. The primary segment 12 also partially overlaps the telescopic joint 7 - there is an opening in the joint after the overhanging segment so that the segment does not have any influence on the function of the telescopic joint 7. Each telescopic joint 7 in this embodiment is formed by two curved arms separated by a rectangular opening.

[0070] The arrangement of the primary segments 12 is influenced by the expected operating temperature of the individual LEDs. The LEDs corresponding to the primary segments 12 in a single row illuminate the area directly in front of the car. This area 15 (in Fig.15 The three LEDs (labeled "I, J, K" in the schematic diagram of the LEDs) require the highest illumination intensity, and therefore the LEDs directed here are more powerful and generate more heat. It is therefore advantageous to give these LEDs more space to prevent overheating, and this is why these three LEDs and their corresponding primary segments 12 are in a single row, with no adjacent LEDs / segments next to them.

[0071] Lens holder 4:

[0072] The lens holder 4 is made of opaque plastic. It has several purposes. First, it carries the secondary optical element 5. There are four snap-on arms on the front side of the lens holder 4, and the secondary optical element 5 has a flange that can be snapped by these arms (see Figure 8 ).exist Figure 7 The arms can be seen in the figure, two of which are visible and the other two are hidden behind the first two. They are the lens holder 4 in Figure 7Each of the arms has an inclined protrusion at its free end, which enables the secondary optical element 5 to be inserted into the lens holder 4 but prevents it from being removed therefrom.

[0073] Next, the lens holder 4 is pressed onto the primary optical element 3. The luminaire 1 is held together by screws, and these screws force the lens holder 4 towards the PCB 9 and the heat sink 11, so that the primary optical element 3 is squeezed in between. On the back side of the lens holder 4 (see Figure 6 ) is provided with a pressing protrusion 22 which contacts the primary optical element 3. This helps to keep the primary optical element 3 straight and stable during use.

[0074] Third, the lens holder 4 includes a mounting pin 21 (see Figure 7 ), which keeps the luminaire 1 components centered in the Y and Z directions. The mounting pins 21 pass through mounting recesses 20 in the primary optical element 3 and also through similarly shaped recesses in the PCB 9 and the heat sink 11. These recesses are also used to align the components during installation, which will be described in further detail below. The lens holder 4 also has another pressing element - these additional pressing elements push the PCB 9 towards the heat sink 11 to prevent it from bulging. They are Figure 6 The rightmost component in .

[0075] Another function of the lens holder 4 is to shield the light emerging from the individual primary segments 12 from any stray light from other primary segments 12. Such stray light may lead to inhomogeneities in the lighting pattern on the road, which may dazzle oncoming traffic etc. Therefore, the lens holder 4 has a shielding grid which creates a tunnel for each primary segment 12 (see Figure 6 or Fig.13 ). The walls of the tunnel enclose the corresponding light beams and prevent the light beams from different LEDs from mixing.

[0076] The lens holder 4 has a plurality of matte surfaces to reduce glare. All surfaces of the grille can be matte. These surfaces absorb light, rather than reflecting it, which again prevents the creation of unevenness in the lighting pattern on the road. The matte finish in the exemplary embodiment is accomplished by increasing the roughness of these surfaces, for example, the injection mold used to produce the lens holder 4 has corresponding surfaces with increased roughness.

[0077] Secondary optics 5:

[0078] The secondary optical element 5 can be made of the same material as the primary optical element 3, for example, it is made of one piece of polycarbonate. The secondary optical element 5 has fifteen secondary segments 13, similar to the primary segments 12 on the primary optical element 3. Each secondary segment 13 has its individual shape, provided by computer simulation together with the shape of the corresponding primary segment 12. The shape is modeled so that the segment sends the light passing through to the desired illuminated area 15 in the desired direction. The position and size of this area 15 is one of the parameters given to the simulation software, which area can be a part of the road ahead or a part of the vertical surface in front of the luminaire 1.

[0079] Each secondary segment 13 has an incident surface for receiving light from the corresponding primary segment 12. The incident surface in the illustrated embodiment protrudes rearward from the secondary optical element 5 (see Figure 5 , Figure 8 and Fig. 9 ).exist Figure 8 It can be seen in FIG. 5 that the secondary segments 13 corresponding to three primary segments 12 in a single row have a greater width than the other secondary segments 13—they extend across the entire width of the secondary optical element 5 , whereas the other secondary segments 13 extend across half the width.

[0080] The left and right sides of the secondary optical element 5 include grooves or teeth that improve the uniformity of the output light by preventing or eliminating glare, similar to the matte surface of the lens holder 4 .

[0081] Each secondary segment 13 also has an exit surface for outputting light. In the depicted embodiment, these surfaces are substantially planar, but they include micro-optical elements for increasing uniformity. These elements can be grooves, scratches, micro-lenses, mutually inclined sub-surfaces, etc. Their size can be up to, for example, 0.5 mm in at least two of their dimensions.

[0082] Each of the LED sub-sources 10 of the light source 2 thus has a corresponding primary section 12, a corresponding tunnel in the shielding grid and a corresponding secondary section 13. These mutually corresponding parts together form a submodule 14. The submodules 14 have essentially independent lighting functions - they do not influence each other, share light between them, etc. However, they share optical elements, which significantly simplifies the assembly of the luminaire 1 and reduces production costs. In other words, the submodules 14 can be optically / luminous independent, but mechanically dependent by sharing optical elements. Therefore, they can each be designed separately, but can be manufactured and assembled together. On the illuminated surface, each module illuminates a specific illuminated area 15 - these areas 15 together partially overlap and form the entire lighting pattern of the luminaire 1, such as a high beam function. The desired shape and intensity of the pattern are known in the art and are often regulated to some extent by traffic laws. Fig.14 A diagram of a submodule 14 is depicted in , together with an image of the resulting illuminated area 15 .

[0083] Due to the mutual independence of the submodules 14, each submodule 14 can direct light to any desired part of the road, that is, its corresponding illuminated area 15 can be located anywhere in the "field of view" of the luminaire 1. In a first exemplary embodiment, the submodules 14 have Fig.16A The submodules 14 are thus arranged in rows, with each row having only one or two submodules 14. In the resulting headlamp 23 (see Fig.10 ), the luminaire 1 thus appears as a substantially vertical bright line whose height is much greater than its width. However, on the road / on the vertical surface in front of the luminaire 1, the corresponding illuminated areas 15 are placed next to each other at the same height / distance from the car. Depending on the overall desired shape and intensity of the resulting illumination pattern of the luminaire 1, some of these areas 15 extend more or less up and down or left and right. Therefore, the arrangement of the areas 15 is rotated by about 90° relative to the arrangement 16 of the submodules 14.

[0084] Fig.15 and Fig.16A Each submodule 14 and area 15 is shown marked by a letter, so that the corresponding submodule 14 and area 15 are easily discernible. The light beams from different submodules 14 can cross each other and can have completely independent directions. Thus, a desired lighting pattern that is always almost the same for a specific lighting function can be provided by any arbitrary arrangement 16 of submodules 14, for example given by customer requirements for the design of the luminaire 1. The shape and inclination of the primary and secondary sections 13 of each submodule 14 can be obtained by simulation software, but the resulting optical element is very complex and therefore very sensitive to assembly precision. Thermal expansion generally destroys the precision. Therefore, the limited influence of thermal expansion achieved by the expansion joint 7 connecting the individual centering parts 6 of the primary optical element 3 is very advantageous.

[0085] For example, the perceived rotation of the arrangement between the submodule 14 and the area 15 is sensitive to thermal expansion - in the absence of the expansion joint 7, the amount of rotation varies with the temperature of the primary optical element 3. Therefore, when the luminaire 1 is just switched on, the inclination of the pattern on the road relative to the Y direction (from left to right) is different from the inclination when the luminaire 1 reaches its higher operating temperature. Such a change in inclination is of course undesirable, and such a headlamp 23 does not comply with legal requirements.

[0086] Assembly:

[0087] The assembly of the luminaire 1 according to the first embodiment substantially follows the method described in WO2022242783 A1. A mounting support 24 with three pins is used as a base for the assembly, and the mounting recesses 20 on the light source 2, the primary optical element 3 and the lens holder 4 receive these pins. Once the lens holder 4 is mounted on the mounting support 24, the recesses on the light source 2 and the primary optical element 3 also receive the corresponding mounting pins 21 of the lens holder 4.

[0088] exist Fig.11 In the embodiment, only the heat sink 11 is placed on the mounting support 24. The pins of the support protrude above the heat sink 11. Fig.12 In the embodiment, the PCB 9 and the primary optical element 3 are added to the pins of the support. Then in Fig.13 The lens holder 4 is added. The secondary optical element 5 can also be added to the lens holder 4, but it is not in contact with the mounting support 24. The mounting support 24 thus holds the components together and aligned with each other so that they can be screwed together. The luminaire 1 is then removed from the mounting support 24.

[0089] In the second exemplary embodiment, the construction of the lamp 1 is the same as that of the first exemplary embodiment. The only difference is that Fig. 16B The arrangement of the submodules 14 shown in FIG. 1 and thus the shape of the primary section 12 and the secondary section 13. The arrangement 17 of the region 15 is the same as in the first embodiment, i.e., it is Fig.15 However, due to the different arrangements of the submodules 14 , the submodules 14 need to have optical devices with different shapes in order to guide the light to the corresponding areas 15 .

[0090] While in the first embodiment the arrangement 16 of the submodules 14 was mainly motivated by design reasons, e.g. the customer wanted to have a headlamp 23 with vertically extending modules, in the second embodiment the submodules 14 are arranged according to their operating temperature. Since some parts of the road need to be illuminated with higher intensity, some LEDs of the light source 2 need to have higher power. Therefore, these LEDs generate more heat. Fig.16AThe temperatures of the submodules 14 along the luminaire 1 are schematically shown - it can be seen that the three LEDs used to illuminate the areas 15 I, J, K heat their respective submodules 14 to higher temperatures where the road needs to be brightest. The highest temperature is at submodule 14 J, as it is placed between submodules 14 K and I, submodules 14k and I are also more powerful and therefore heat submodule 14 J more.

[0091] Fig. 16B The arrangement 16 of submodules 14 in the second embodiment has the three hottest LEDs separated by a group of cooler LEDs. Each submodule 14 still illuminates the same area 15 at the same location on the road / vertical surface, so from the outside there is no obvious difference between the first and second embodiments. However, as can be seen from Fig. 16B As can be seen in , since the three hottest LEDs / submodules 14 are not grouped together, they do not heat each other as much, and therefore their respective operating temperatures are lower. Fig. 16B Three peaks can be seen in the temperature curve of Fig.16A The maximum temperature in the luminaire 1 is thus reduced by the arrangement 16 of the submodules 14 according to the second embodiment. The temperature along the luminaire 1 is also more uniform.

[0092] Because the technician knows in advance which LEDs are expected to have higher temperatures when the luminaire 1 is turned on, the expected operating temperature or expected heat generated by each LED or submodule 14 can be taken into account when designing the luminaire 1. The technician can design the arrangement 16 of the submodules 14 himself, or the operating temperature can be input into the simulation software, which outputs the arrangement and shape of each segment.

[0093] Obviously, the submodules 14 may be arranged in many more different ways, based on design requirements, the heat output of the LEDs, the available space in the headlamp, etc. The cooling strength of the radiator 11 may also be considered, as well as the fact that hotter air tends to flow upward. For example, the radiator 11 may have the highest cooling strength at its lower portion, so one of the hotter submodules 14 may be the lowermost submodule 14. Another of the modules may be the uppermost submodule 14, since the heat from that submodule 14 will not heat any submodules 14 located higher.

[0094] Two further examples of submodule 14 arrangements are shown in FIG18. Fig.18A In the embodiment, the submodules 14 have a circular arrangement. This may be the result of a customer's design requirements for the luminaire 1, for example. The primary and secondary sections 13 are then shaped and oriented again so that they each illuminate their corresponding illuminated area 15, and the lighting pattern on the road thus appears identical to the first embodiment. Fig.18B In the embodiment, the arrangement 16 of the submodules 14 is in a "V" shape, which is also required by the design, but it is also possible to provide three submodule 14 positions, in which the submodule 14 is not surrounded on both sides by other submodules 14. These positions thus contain submodules 14 I, J, K. The heat from these three submodules 14 is thus dissipated more freely.

[0095] Many other additional configurations will be apparent to those skilled in the art. In some embodiments, the arrangement 16 of the submodules 14 may be horizontal, as is typical for a matrix headlamp 23, but the individual LEDs may also be arranged so that the hotter LEDs are separated from one another. The number of submodules 14 may be different than fifteen, for example, there may be additional submodules 14 for lighting of traffic signs and the like.

[0096] In other alternative embodiments, the primary optical element 3 may have a protruding entrance surface and a substantially flat exit surface, and / or the secondary optical element 5 may have a substantially flat entrance surface and a protruding exit surface.

[0097] The number of parts 6 of the primary optical element 3 may also vary. At least two parts 6 are required, but in order to fully exploit the advantages of the expansion joint 7, at least three parts 6 are preferred. The number of primary segments 12 on each part 6 may also vary - there may be parts 6 with only a single primary segment 12 on them, there may be parts 6 carrying five or more segments, etc. When selecting the number of segments for a part 6, the expected operating temperature may be taken into account.

[0098] The complexity of the optics may also be taken into account when selecting the number of parts 6 or the number of segments for each part 6. For example, for less complex optics geometries, for example when the arrangement 16 of the submodules is horizontal and the submodules 14 have the same order as the areas 15, two parts 6 on the primary optical element 3 may be sufficient. On the other hand, for more complex geometries, for example when the segments have micro-optics on their entrance and / or exit surfaces and the arrangement 16 of the subsegments differs significantly from the arrangement 17 of the areas 15 (e.g. as depicted in FIG. 18 ), more parts 6 with fewer segments per part 6 may be advantageous. In some embodiments, there may even be only a single segment on some or all parts 6.

[0099] The expansion joints 7 may have a different shape than in the depicted embodiment. For example, there may be only one or only two bends 8 on the joint. Or the joint may be shaped so that the bends are in the plane of the body of the element. That is, when viewed from the side, the expansion joints 7 may not be discernible, but when viewed from the front, each joint may be seen as a segment of an element with a cutout and a curved arm connecting the portions 6. For example, Figure 1 The two lateral arms of the central telescopic joint 7 can be rotated through 90° and can thus be placed completely between the parts 6 without protruding forwards or backwards.

[0100] Instead of two curved arms separated by an opening, the telescopic joint 7 may, for example, have only one arm, which extends across the entire width of the primary optical element 3. The primary segments 12 then preferably do not overhang their respective parts 6.

[0101] Mounting and assembly means and elements may also be different. Any way of assembling luminaires 1 and aligning their components known to the skilled person may be used as part of the luminaire 1 .

[0102] Reference numerals list

[0103] 1. Lighting

[0104] 2. Light source

[0105] 3. Primary Optics

[0106] 4. Lens holder

[0107] 5. Secondary Optics

[0108] 6. Part

[0109] 7. Expansion joints

[0110] 8. Bending part

[0111] 9. Printed Circuit Board

[0112] 10. Sub-source

[0113] 11. Radiator

[0114] 12. Primary Section

[0115] 13. Secondary Sections

[0116] 14. Submodules

[0117] 15. Light up the area

[0118] 16. Arrangement of submodules

[0119] 17. Area layout

[0120] 18. Alignment pin

[0121] 19. Alignment holes

[0122] 20. Installation recess

[0123] 21. Mounting pin

[0124] 22. Extrusion protrusion

[0125] 23. Headlights

[0126] 24. Install the support

Claims

1. A vehicle lamp (1), comprising a light source (2), a primary optical element (3), a lens holder (4) and a secondary optical element (5), wherein the primary optical element (3) is held between the light source (2) and the lens holder (4), characterized in that: The primary optical element (3) comprises at least two parts (6), and the primary optical element further comprises at least one expansion joint (7) for limiting the influence of thermal expansion of adjacent parts (6) on each other, wherein the adjacent parts (6) are separated from each other by at least one expansion joint (7), and wherein each part (6) comprises at least one alignment member for individual alignment of the part (6) relative to at least one other part of the luminaire (1).

2. The vehicle lamp (1) according to claim 1, wherein the portion (6) of the primary optical element (3) and the at least one expansion joint (7) are made from a single piece of material.

3. The vehicle lighting device (1) according to any one of the preceding claims, wherein: Each expansion joint (7) is formed as a curved section of the primary optical element (3) and / or as a section of the primary optical element (3) with a reduced cross section.

4. The vehicle lamp (1) according to claim 3, wherein each expansion joint (7) has a cross-section including three bends (8), wherein one bend (8) located between the other two bends (8) is bent in a direction opposite to the other two bends (8).

5. The vehicle lighting device (1) according to any one of the preceding claims, wherein: The lens holder (4) is pressed against the primary optical element (3) at each portion (6).

6. The vehicle lighting device (1) according to any one of the preceding claims, wherein: The primary optical element (3) has a substantially planar light entrance surface, and / or the secondary optical element (5) has a substantially planar light exit surface.

7. The vehicle lighting device (1) according to any one of the preceding claims, wherein: The light source (2) comprises a printed circuit board (9) with LED sub-sources (10) and a heat sink (11), wherein the light source (2) comprises complementary alignment features for the alignment features of the primary optical element (3).

8. A vehicle lamp (1) according to any of the preceding claims, wherein each part (6) of the primary optical element (3) comprises at least one primary segment (12), wherein each primary segment (12) is individually shaped and oriented for processing and guiding light from the light source (2).

9. The vehicle lamp (1) according to claim 8, wherein the secondary optical element (5) comprises a plurality of secondary segments (13), wherein each secondary segment (13) is aligned with a corresponding primary segment (12), wherein each secondary segment (13) is individually shaped and oriented for processing and directing light from the corresponding primary segment (12).

10. The vehicle lamp (1) according to claim 9, wherein: The lens holder (4) comprises a shielding grid for splitting a light beam passing between the corresponding primary section (12) and the secondary section (12).

11. The vehicle lighting device (1) according to claim 10, wherein the shielding grid has at least one roughened or matte surface for reducing glare.

12. The vehicle lamp (1) according to any one of claims 8 to 11, wherein: Each primary segment (12) and its corresponding secondary segment (13) have a corresponding sub-source (10) of light on the light source (2), wherein the mutually corresponding primary segments (12), secondary segments (13) and sub-sources (10) form a lighting sub-module (14) for illuminating a lighting area (15) in front of the lamp (1), wherein the light output directions of at least some of the lighting sub-modules (14) are not parallel to each other, and wherein the arrangement (16) of the lighting sub-modules (14) on the lamp (1) is different from the arrangement (17) of their corresponding lighting areas (15).

13. The vehicle lamp (1) according to claim 12, wherein for at least some of the lighting submodules (14), the arrangement (16) of the lighting submodules (14) on the lamp (1) is rotated relative to the arrangement (17) of their corresponding illuminated areas (15), wherein some of the lighting submodules (14) are arranged vertically one above the other, and when the lamp (1) illuminates a flat vertical surface from a predetermined distance, the corresponding illuminated areas (15) of the vertically arranged lighting submodules (14) are arranged at substantially the same height on the vertical surface.

14. The vehicle lamp (1) according to any one of claims 12 to 13, wherein the lighting submodules (14) are arranged in the lamp (1) at least partially based on their operating temperatures, wherein some lighting submodules (14) with a higher operating temperature are separated from each other by at least one lighting submodule (14) with a lower operating temperature, and wherein illuminated areas (15) of the lighting submodules (14) with the higher operating temperature are directly adjacent or overlapping.

15. A vehicle headlamp (23), characterized in that: It comprises a plurality of lighting modules, wherein at least two of the lighting modules are vehicle lamps (1) according to any one of claims 12 to 14.

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