Optical element, lighting unit, and vehicle

Abstract

An optical element, a lighting unit and a vehicle are disclosed.SOLUTION: The optical element comprises one or more entrance portions for receiving light rays from one or more light sources (120), one or more total internal reflection (TIR) surfaces (108), the one or more total internal reflection (TIR) surfaces (108) being configured to receive the light rays from the one or more entrance portions and to focus the light rays received from the one or more entrance portions in a vertical direction (y) and a horizontal direction (x) by TIR, and one or more exit portions (180) comprising one or more exit lenses (140), One or more exit lenses comprising one or more exit portions 180 comprising a plurality of Fresnel structures configured to horizontally and / or vertically collimate and / or diffuse light rays exiting the optical element, wherein the optical element is formed as a monolithic body.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The solution generally relates to an optical element for a vehicle headlamp, to a lighting unit comprising said optical element, and to a vehicle comprising said lighting unit. [Background technology]

[0002] Vehicle headlamps are used to generate low and / or high beam light patterns to illuminate the area in front of the vehicle. Headlamps are not limited to road traffic, but are also used in work vehicles such as vehicles for construction, mining, agriculture, forestry, and material handling. Nevertheless, such headlamps may need to meet several requirements, including those set for vehicles in road traffic.

[0003] Headlamps aim to achieve a precise and well-controlled lighting pattern while meeting various technical requirements. Headlamp users prefer good forward and side lighting performance with minimal glare for the user, oncoming vehicles, and bystanders. Size and manufacturing constraints are also taken into consideration, with the goal of reducing headlamp size while making the headlamp easier to manufacture. Thermal performance is another relevant consideration.

[0004] French patent application FR 3 010 772 describes a light emitting device for a motor vehicle headlight, and European patent application EP 3 653 926 describes a lighting device for a motor vehicle headlamp and a motor vehicle headlamp. Summary of the Invention

[0005] The scope of protection sought for various embodiments of the invention is indicated by the independent claims. Various embodiments are disclosed in the dependent claims. Embodiments and features described herein that do not fall within the scope of the independent claims, if any, should be interpreted as examples useful for understanding various embodiments of the invention.

[0006] According to a first aspect, an optical element for a vehicle headlamp comprises one or more entrance portions for receiving light rays from one or more light sources; one or more total internal reflection (TIR) ​​surfaces configured to receive the light rays from the one or more entrance portions and to focus the light rays received from the one or more entrance portions in vertical and horizontal directions by TIR; and one or more exit portions comprising one or more exit lenses, the one or more exit lenses comprising a plurality of Fresnel structures configured to collimate and / or diffuse light rays exiting the optical element in the horizontal and / or vertical directions, wherein the optical element is formed as a monolithic body.

[0007] The optical element may comprise one or more optical cutters configured to shape a cutoff profile of light rays passing by TIR from the one or more entrance portions to the one or more exit lenses.

[0008] The optical element may comprise one or more focusing surfaces configured to receive light rays reflected by the one or more optical cutters and reflect the light rays received from the one or more optical cutters towards the one or more exit lenses by TIR.

[0009] At least one of the one or more focusing surfaces may be configured to collimate the light beam received from the one or more light cutters towards the one or more exit lenses.

[0010] At least one of the one or more focusing surfaces may be configured to focus the light beam received from the one or more light cutters in the vertical direction and the horizontal direction.

[0011] The optical element may comprise a plurality of optical cutters and a plurality of exit portions, wherein a first one or more optical cutters of the plurality of optical cutters are arranged to form a cutoff profile of light rays received from the one or more entrance portions and / or from the one or more TIR surfaces and are configured to exit the optical element through a first one or more exit portions of the plurality of exit portions, and a second one or more optical cutters of the plurality of optical cutters are arranged to form a cutoff profile of light rays received from the one or more focusing surfaces and are configured to exit the optical element through a second one or more exit portions of the plurality of exit portions.

[0012] The one or more TIR surfaces and / or the one or more collection surfaces may comprise a plurality of flat and / or curved facets.

[0013] The plurality of Fresnel structures may comprise ring-shaped Fresnel structures and / or horizontally and / or vertically stacked rectangular Fresnel structures.

[0014] The one or more exit sections may comprise one or more exit lenses that do not have a Fresnel structure.

[0015] The plurality of Fresnel structures may include at least two different types of Fresnel structures.

[0016] The optical elements may be made of or include polycarbonate, polymethylmethacrylate, optical silicone, glass, or mixtures thereof.

[0017] At least one TIR surface of the one or more TIR surfaces may have a first focus and a second focus for focusing the light rays received from the one or more entrance portions, the first focus and the second focus being substantially coincident.

[0018] At least one TIR surface of the one or more TIR surfaces may have a first focus and a second focus for focusing the light rays received from the one or more entrance portions, wherein the first focus and the second focus do not substantially coincide.

[0019] One of the first focal point and the second focal point may be positioned farther from the at least one TIR surface than the other of the first focal point and the second focal point.

[0020] The first focal point and the second focal point may be at different positions in the horizontal direction.

[0021] The one or more exit lenses may include a plurality of exit lenses comprising a plurality of the Fresnel structures.

[0022] The optical element may comprise a plurality of entrance portions for receiving light rays from the one or more light sources, and a plurality of TIR surfaces configured to receive the light rays from the plurality of entrance portions and to focus the light rays received from the plurality of entrance portions in the vertical and horizontal directions by TIR.

[0023] The plurality of TIR surfaces may include substantially parallel optical axes for focusing the light rays.

[0024] The plurality of TIR surfaces may include substantially non-parallel optical axes for focusing the light rays.

[0025] The one or more exit lenses may comprise a plurality of exit lenses, including at least one exit lens for each of the plurality of TIR surfaces.

[0026] The optical element may comprise a plurality of horizontally and / or vertically adjacent exit lenses.

[0027] At least one of the one or more exit sections may comprise only one of the one or more exit lenses.

[0028] At least one focal point of one or more of the one or more TIR surfaces may substantially coincide with a focal point of at least one of the one or more exit lenses.

[0029] At least one focal point of one or more of the one or more TIR surfaces may not substantially coincide with a focal point of the one or more exit lenses.

[0030] The one or more exit lenses may include a first exit lens having a first Fresnel structure configured to collimate a first portion of the light rays exiting the optical element, and a second exit lens having a second Fresnel structure configured to diffuse a second portion of the light rays exiting the optical element.

[0031] The multiple Fresnel structures of at least one of the one or more exit lenses may include a first Fresnel structure configured to collimate light rays exiting the optical element and a second Fresnel structure configured to diffuse light rays exiting the optical element.

[0032] The Fresnel structures of at least one of the one or more exit lenses may be configured to spread light rays exiting the optical element at two or more different divergence angles.

[0033] According to a second aspect, an illumination unit comprises one or more light sources and one or more of said optical elements.

[0034] The lighting unit may be a vehicle headlamp.

[0035] According to a third aspect, a vehicle comprises the lighting unit. [Brief explanation of the drawings]

[0036] [Figure 1] FIG. 1 is a diagram showing an embodiment of a headlamp. [Figure 2]FIG. 2 is a diagram showing the passage of light rays within the headlamp of FIG. [Figure 3] FIG. 3 is a side view of an embodiment of an optical element. [Figure 4] FIG. 4 is a bottom view of the first embodiment of the optical element. [Figure 5] FIG. 5 is a bottom view of the second embodiment of the optical element. [Figure 6] FIG. 6 is a top view of a third embodiment of the optical element. [Figure 7] FIG. 7 is a top view of a fourth embodiment of the optical element. [Figure 8] FIG. 8 is a diagram showing a low beam modification of the fourth embodiment. [Figure 9] FIG. 9 is a diagram showing a high beam modification of the fourth embodiment. [Figure 10] FIG. 10 is a bottom view of the fifth embodiment of the optical element. [Figure 11] FIG. 11 is a diagram showing the fifth embodiment. [Figure 12] FIG. 12 is a diagram showing a high beam modification of the fifth embodiment. [Figure 13] FIG. 13 is a diagram showing a sixth embodiment of the optical element. [Figure 14] FIG. 14 is a diagram showing a seventh embodiment of the optical element. [Figure 15] FIG. 15 is a diagram showing an eighth embodiment of the optical element. [Figure 16] FIG. 16 is a diagram showing a ninth embodiment of the optical element. [Figure 17] FIG. 17 is a diagram showing a tenth embodiment of the optical element. [Figure 18] FIG. 18 is a diagram showing an eleventh embodiment of the optical element. [Figure 19] FIG. 19 shows simulated light patterns for the tenth embodiment. [Figure 20] FIG. 20 shows simulated light patterns of the eleventh embodiment. [Figure 21]FIG. 21 shows various configurations of focal points within an optical element. [Figure 22] FIG. 22 shows a further configuration of focal points within an optical element. [Figure 23] FIG. 23 is a side view of a twelfth embodiment of the optical element. [Figure 24] FIG. 24 is a top view of a thirteenth embodiment of the optical element. [Figure 25] FIG. 25 illustrates simulated light patterns for various embodiments of the optical element. [Figure 26] FIG. 26 illustrates simulated light patterns for various embodiments of faceted optical elements. [Figure 27] FIG. 27 is a side view of a fourteenth embodiment of the optical element. [Figure 28] FIG. 28 is a diagram showing a fifteenth embodiment of the optical element. [Figure 29] FIG. 29 is a diagram showing a sixteenth embodiment of the optical element. [Figure 30] FIG. 30 shows a simulated light pattern of the entire beam of the sixteenth embodiment. [Figure 31] FIG. 31 is a diagram showing a simulated light pattern of the lower beam of the sixteenth embodiment. [Figure 32] FIG. 32 is a diagram showing a simulated light pattern of the upper beam of the sixteenth embodiment. [Figure 33] FIG. 33 is a diagram showing a headlamp having an optical element according to the seventeenth embodiment. [Figure 34] FIG. 34 is a front view of the headlamp of FIG. DETAILED DESCRIPTION OF THE INVENTION

[0037] The following description and drawings are illustrative and should not be construed as unnecessarily limiting. Specific details are provided for a thorough understanding of the present disclosure. However, in certain instances, well-known or conventional details are not described to avoid obscuring the description. In this specification, a reference to "one embodiment" or "one embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment is included in at least one embodiment of the present disclosure. A reference to one embodiment may, but is not necessarily, a reference to the same embodiment in the present disclosure.

[0038] The present disclosure relates to an optical element for a vehicle headlamp, a lighting unit including the optical element, and a vehicle including the lighting unit. The optical element is suitable for use in a headlamp, but may also be used in other types of lighting units, such as a work light. Work lights are often used to illuminate work areas where workers, work machines, and / or work vehicles operate. The optical element is particularly suitable for headlamps for various types of work lights and work vehicles. The optical element's compact size and well-controlled light distribution characteristics make it suitable for a variety of work and driving scenarios.

[0039] Some examples of work vehicles include:

[0040] -Construction vehicles such as articulated trucks, asphalt pavers, wheel loaders, bulldozers / track dozers, compactors / road rollers, excavators, mobile cranes, motor graders / scrapers, pile drivers, skid steer loaders, and telehandlers.

[0041] Mining vehicles such as articulated trucks, blast hole drills, bucket wheel excavators, drilling rigs / continuous miners, draglines, dump trucks, highwall miners, hydraulic excavators / rope shovels, Load Haul Dumps (LHDs), rocket boomers / digging jumbos, surface miners, and wheel loaders.

[0042] -Forestry vehicles such as chippers, derimbers, feller bunchers, forwarders, harvesters, knuckle boom loaders, logging trucks, skidders, swing machines and track dozers.

[0043] Agricultural vehicles such as bean harvesters, beet harvesters, combine harvesters, crop sprayers, forage harvesters, pea harvesters, potato harvesters, rapeseed windrowers, slurry spreaders, and tractors.

[0044] -Material handling vehicles such as forklift trucks, Rubber-Tyre Gantry Cranes (RTGs), reach stackers, straddle carriers, towing tractors, telehandlers, and truck-mounted cranes.

[0045] As is conventional in the art, reference is made herein to directions to describe various aspects of the embodiments and their features. The horizontal direction refers to the direction extending sideways or side to side when looking at the light-emitting surface of the headlamp or optical element from a forward perspective. This perspective generally corresponds to the perspective of an oncoming vehicle when the headlamp is mounted on a vehicle. The vertical direction refers to the direction extending up and down when looking at the light-emitting surface of the headlamp or optical element from a forward perspective. The longitudinal direction refers to the direction extending inward and outward from the headlamp and / or optical element when looking at the light-emitting surface of the headlamp or optical element from a forward perspective. The longitudinal direction may extend along the longitudinal axis of the optical element, as shown in the figures. In this specification and in the figures, the horizontal direction is designated by x, the vertical direction is designated by y, and the longitudinal direction is designated by z. To facilitate understanding of the different embodiments and their features, axes indicating relevant directions are provided in some of the figures.

[0046] FIG. 1 illustrates a vehicle headlamp 100 according to one embodiment. The headlamp includes a light source 120, preferably a light-emitting diode (LED) light source, within a space 116 facing an entrance portion 106 of an optical element 102. The optical element of this embodiment includes a light cutter 104 for forming a cutoff profile of light rays emitted by the light source. The light cutter is formed as a recess or cavity within the optical element, whereby the light cutter blocks or redirects light rays traveling from the light source toward the light cutter, thus forming a cutoff profile of light rays exiting the optical element through its exit lens 140. The cutoff profile makes the optical element suitable for use in a low-beam headlamp, and thus the headlamp 100 may be a low-beam headlamp. Alternatively, the optical element may be implemented without the light cutter 104 so that a cutoff profile is not formed. Such an optical element is suitable for use in a high-beam headlamp. All of the embodiments described herein may be implemented with or without a light cutter, unless otherwise specified. Optical elements with partial light cutters that affect only a portion of the light beam, and combinations of two or more optical elements (at least one with a light cutter and at least one without a light cutter) are also contemplated to achieve a combined high beam and low beam headlight. Some details of the light cutters shown in the drawings and described herein have been omitted to avoid obscuring the description.

[0047] Suitable light sources for headlamps include LEDs, such as automotive LEDs, which are generally smaller and more powerful than other types of LEDs. Other suitable light sources include Laser Excited Phosphor (LEP) light sources, which allow for even smaller sizes. LEPs have a smaller light emitting spot (LES) than LEDs. Light source 120 can include one or more light sources, such as those described above.

[0048] The headlamp 100 further comprises a heat sink 112 and a holder 114 for the optical element 102. In the illustrated embodiment, the optical element 102 is surrounded by an open space 116 (e.g., filled with air) within the holder 114. A printed circuit board (PCB) 118 is located between the heat sink and the holder. A light source 120 is mounted on and electrically coupled to the PCB. The light emitted by the light source can be controlled by the PCB.

[0049] The optical element 102 is preferably formed as a single piece or monolithic body. The optical element is made of a transparent or transmissive material, preferably a single material or a substantially uniform mixture of materials. For example, the optical element may include or be made of optical silicone, such as polycarbonate (PC), polymethyl methacrylate (PMMA), or polydimethysiloxane (PDMS), glass, or a mixture including one or more of the aforementioned materials. Optical silicone is sometimes known as moldable silicone. The surface of the optical element facilitates total internal reflection (TIR) ​​of light rays traveling within the optical element when the light rays intersect the surface of the optical element at a specific angle. Those skilled in the art are aware of the principles of TIR.

[0050] The optical elements can be manufactured, for example, by injection molding or liquid silicone rubber (LSR) injection molding. These techniques are particularly applicable to optical elements containing or made of PMMA, PC, and / or PDMS, and allow for good tolerances. Another suitable technique is precision glass molding, especially for optical elements containing or made of glass.

[0051] The optical element may be partially or entirely coated with one or more materials and / or layers of materials (e.g., metallization) that provide or enhance its TIR or other optical properties and increase efficiency. Such coatings may be applied, for example, by vacuum metallization. The optical element may be partially surrounded, at least at the TIR surface and optionally elsewhere, by a material that provides or enhances its TIR properties. For example, the space around the optical element in the headlamp of FIG. 1 may be filled with such a material.

[0052] If the TIR surface 110 of the optical cutter is coated with metallization, a cleaner light cutting effect can be obtained. Considering the embodiments of Figures 27-29, the additional light reflected upward can improve the efficiency of the light output.

[0053] Alternatively or additionally, the TIR surface 108 may be coated with a metallization, which can improve the TIR effect, especially for light rays arriving at too high an angle of incidence, thereby further improving the efficiency.

[0054] The surface of the entrance portion 106 where light enters the optical element and / or the surface of the exit lens 140 may be coated with one or more anti-reflective (AR) coatings. For example, AR coatings, applied as thin layers of materials with a particular refractive index, minimize the amount of reflected light by creating destructive interference with the reflected light waves. This interference cancels out reflections, allowing more light to pass through the surface and reducing glare.

[0055] As described above, the surface of the optical element is configured to perform TIR on light rays traveling within the optical element. The surface performs TIR on light rays traveling from the light source 120 toward an exit portion 180, which has an exit lens 140 of the optical element at the opposite end of the optical element from where the light rays exit the optical element. A TIR surface 108 is formed near the entrance portion of the optical element for reflecting light rays received through the entrance portion toward the exit portion of the optical element. The optical cutter also includes a TIR surface 110 that reflects light arriving from the TIR surface 108 or light arriving directly from the light source 120 through the entrance portion of the optical element. The operation of the TIR surface 108, the optical cutter 104, and the exit lens 140 are described in more detail below with respect to this and additional embodiments.

[0056] Figure 2 illustrates the passage of light rays 200 emitted by the light source 120 through the optical element 102 of the headlamp 100 of Figure 1. Light emitted by the light source enters the optical element via the entrance portion 106 (see Figure 1). In an embodiment, the entrance portion comprises a plurality of entrance surfaces configured to refract the light rays emitted by the light source as they enter the optical element 102. As shown in Figure 2, the entrance surfaces are configured to focus the light rays (by refraction). Alternatively or additionally, the entrance portion may be configured to diffuse the light rays (by refraction) and / or simply transmit the light rays.

[0057] A first portion of the light beam travels from the entrance portion of the optical element toward the TIR surface 108, and a second portion of the focused light beam travels from the entrance portion to the exit portion of the optical element. The first portion of the light beam is reflected and focused by the TIR surface. The TIR surface has one or more foci for focusing the light beam in the vertical direction y and in a horizontal direction extending perpendicular to the directions y and z in the drawing. For example, the TIR surface may have a first focus for focusing the light beam in the vertical direction y and a second focus for focusing the light beam in the horizontal direction. This may be implemented, for example, with an ellipsoidally shaped TIR surface.

[0058] The TIR surface may have perfect rotational or circular symmetry about the (optical) axis. In this case, the first and second foci mentioned above coincide. The (optical) axis is preferably parallel to the direction z shown in Figures 1 and 2. The (optical) axis therefore extends longitudinally along the headlamp 100 and optical element 102 from the light source 120 to the exit lens 140.

[0059] The focal point of the TIR surface preferably coincides with the optical cutter 104. For example, the focal point may coincide with the tip of the optical cutter. FIG. 2 shows that the first focal point of the TIR surface 108 for focusing light rays in the vertical y direction coincides with the tip of the optical cutter. Coincidence with the optical cutter (most preferably its tip) is preferred for automobile headlights because a sharper cutoff can be achieved due to the specific requirements of automobile headlights for the characteristics of the cutoff light pattern generated using an optical cutter. However, if one or more of the focal points of the TIR surface 108 are offset or shifted from (the tip of) the optical cutter 104, the diffusion of the light rays can be better controlled. An additional advantage is the broadening of the heat peak caused by the arriving light rays, thus reducing the thermal load in the optical cutter 104. Preferably, the focal point of the TIR surface for focusing light rays in the horizontal direction is offset from (the tip of) the optical cutter, and preferably, the focal point of the TIR surface for focusing light rays in the vertical y direction coincides with (the tip of) the optical cutter. This achieves precise cutoff of the light pattern produced by the headlamp with the optical element while reducing the heat load caused by light rays reaching the light cutter. Various configurations of focal points within the optical element are described in more detail below with reference to Figures 21 and 22.

[0060] FIG. 3 shows a side view of some embodiments of the optical element 302. Light rays 300 travel from the entrance portion to a TIR surface 308. The TIR surface focuses the light rays in the vertical direction y. The TIR surface has a focal point for focusing the light rays in the vertical y direction. The focal point is substantially coincident with the tip of the optical cutter 304. The light rays travel to an exit portion 380 where one or more exit lenses having Fresnel structures 324, 326 collimate the light rays in the vertical direction y. The one or more exit lenses may further collimate and / or diverge the light rays in a horizontal direction extending perpendicular to the directions y and z in the drawing. The optical element 302 may otherwise be similar to that shown in FIGS. 1 and 2.

[0061] FIG. 4 shows a bottom view of a first embodiment of an optical element 402. Light rays 400 travel from the entrance portion to a TIR surface 408. The TIR surface focuses the light rays in a horizontal direction x. The TIR surface has a focal point for focusing the light rays in the horizontal direction. The focal point is substantially coincident with the tip of the light cutter 404, i.e., the junction between surfaces 410 and 412, which form a cavity that acts as the light cutter. The light cutter includes longitudinal grooves 450 for blocking light in a specific region of the light pattern. In this specification, the specific region is the side of oncoming vehicles, and the grooves improve the low-beam light pattern. The light rays travel to an exit portion 480 where an exit lens having multiple Fresnel structures 324 collimates the light rays in the horizontal direction x. The optical element 402 may otherwise be similar to that shown in FIGS. 1-3.

[0062] 5 shows a top view of a second embodiment of an optical element 502. The second embodiment is otherwise similar to the first embodiment, except that an exit portion 580 of the optical element comprises an exit lens having a plurality of Fresnel structures 524 configured to spread light rays 500 in the horizontal direction x.

[0063] The Fresnel structure 524 may be configured to diffuse light rays with different (non-zero) divergence angles, i.e., some light rays are more diffused than others. Different divergence angles may be obtained by different Fresnel structures; for example, a first Fresnel structure may be configured to diffuse light rays with a first divergence angle, and a second Fresnel structure may be configured to diffuse light rays with a second divergence angle different from the first divergence angle. The divergence angles may be measured relative to an optical axis parallel to the longitudinal direction z. For completeness, collimated light rays may have a divergence angle equal to zero, and diffused light rays may have a non-zero divergence angle. This applies to all embodiments in which a diffusing Fresnel structure is present. The different divergence angles make it possible to generate very finely tuned light patterns.

[0064] The first and second embodiments may be combined such that the exit lens comprises both a Fresnel structure configured to collimate the light rays and a Fresnel structure configured to diffuse the light rays. In this case, the Fresnel structures are part of the same exit lens. Thus, a compact and multifunctional design is achieved. Multiple such lenses may be included in the optical element.

[0065] FIG. 6 illustrates a top view of a third embodiment of an optical element 602. The optical element 602 includes a plurality of entrance portions 606a-c having a corresponding plurality of TIR surfaces 608a-c. A light source may be provided at each one of the entrance portions 606a-c. Each of the plurality of TIR surfaces may be similar to those described above in connection with FIGS. 1-3. The first entrance portion 606a has a corresponding first TIR surface 608a for focusing light rays received from the first entrance portion 606a, the second entrance portion 606b has a corresponding second TIR surface 608b for focusing light rays received from the second entrance portion 606b, and the third entrance portion 606b has a corresponding third TIR surface 608c for focusing light rays received from the third entrance portion 606b. The multiple TIR surfaces, i.e., first TIR surface 608a, second TIR surface 608b, and third TIR surface 608c, focus the light rays received from the multiple entrance portions, i.e., first entrance portion 606a, second entrance portion 606b, and third entrance portion 606c. Focusing the light rays in the horizontal direction x is shown in Figure 6, and the TIR surfaces may also perform focusing in the vertical direction as shown in Figure 3.

[0066] In a third embodiment, the TIR surfaces include substantially non-parallel optical axes for focusing light rays 600. This applies when focusing light rays in the horizontal direction x, as shown in Figure 6, and if the TIR surface also performs vertical focusing, as shown in Figure 3, the TIR surface may have substantially parallel or substantially non-parallel optical axes for focusing light rays in the vertical direction.

[0067] Each of the TIR surfaces 608a-c has a focal point for converging the light rays in the horizontal direction x. The focal points of the TIR surfaces are substantially coincident, thus forming a common focal point 630. The common focal point substantially coincides with the focal point of the exit lens 640 of the exit portion 680 of the optical element. A single exit lens 640 shared by multiple light sources and their corresponding entrance portions 606a-c and TIR surfaces 608a-c is optically more efficient because it reduces light loss between or at the edges of the multiple exit lenses. The coincidence of the foci of the TIR surfaces 608a-c and the exit lens 640 results in larger spikes of intensity in the resulting illumination pattern of the optical element 602. The single exit lens 640 comprises multiple Fresnel structures 624 configured to collimate the light rays 600 in the horizontal direction x. Collimation is enhanced by the coincidence of the foci of the TIR surfaces 608a-c and the exit lens 640.

[0068] 7 shows a top view of a fourth embodiment of an optical element 702. The fourth embodiment is otherwise similar to the third embodiment, except that an exit portion 780 of the optical element comprises an exit lens 740 having a plurality of Fresnel structures 724 configured to spread light rays in the horizontal direction x.

[0069] The third and fourth embodiments may be combined such that the exit lens comprises both a Fresnel structure configured to collimate the light rays and a Fresnel structure configured to diverge the light rays.

[0070] Figure 8 shows a low beam variation of the fourth embodiment. The optical element 802 shown in Figure 8 has an optical cutter for forming a cutoff profile of the light rays passing from the entrance portions 806a-c to the exit lens 840. The optical cutter is similar to that described in connection with the previous figures. The optical element 802 otherwise has the features described in connection with the fourth embodiment.

[0071] 9 shows a high beam variation of the fourth embodiment. Optical element 902 lacks an optical cutter, and therefore does not form a sharp cutoff profile for light rays passing from entrance portions 906a-c to exit lens 940. Optical element 902 otherwise has the features described in connection with the fourth embodiment.

[0072] The third embodiment of Figure 6 can be implemented as a low beam variant, ie with a light cutter, and as a high beam variant, ie without a light cutter.

[0073] FIG. 10 shows a bottom view of a fifth embodiment of an optical element 1002. Similar to the third and fourth embodiments, the optical element 1002 includes a plurality of entrance portions 1006a-c having a corresponding plurality of TIR surfaces 1008a-c. A light source may be provided at each one of the entrance portions 1006a-c. Each of the plurality of TIR surfaces may be similar to those described above in connection with FIGS. 1-3. The first entrance portion 1006a has a corresponding first TIR surface 1008a for focusing light rays received from the first entrance portion 1006a, the second entrance portion 1006b has a corresponding second TIR surface 1008b for focusing light rays received from the second entrance portion 1006b, and the third entrance portion 1006b has a corresponding third TIR surface 1008c for focusing light rays received from the third entrance portion 1006b. The multiple TIR surfaces, i.e., first TIR surface 1008a, second TIR surface 1008b, and third TIR surface 608c, focus the light rays received from the multiple entrance portions, i.e., first entrance portion 1006a, second entrance portion 1006b, and third entrance portion 1006c. Focusing the light rays in the horizontal direction x is shown in Figure 10, and the TIR surfaces may also perform focusing in the vertical direction as shown in Figure 3.

[0074] In a fifth embodiment, the TIR surfaces include substantially parallel optical axes for focusing light rays 1000. This applies when focusing light rays in the horizontal direction x, as shown in Figure 10; if the TIR surfaces also perform vertical focusing, as shown in Figure 3, the TIR surfaces may have substantially parallel or substantially non-parallel optical axes for focusing light rays in the vertical direction.

[0075] The TIR surfaces 1008a-c each have a focal point 1030a-c for focusing light rays in the horizontal direction x. These focal points of the TIR surfaces do not coincide. These focal points substantially coincide with corresponding focal points of the exit lenses 1040a-c of the exit portions of the optical elements. The technical effect of this coincidence is described above in connection with FIG. 6.

[0076] As described above, the optical element 1002 includes an exit portion 1080 having multiple exit lenses 1040a-c, one corresponding to each of the TIR surfaces 1008a-c. These exit lenses are adjacent in the horizontal direction x. The first exit lens 1040a is configured to receive light rays reflected by the first TIR surface 1008a, the second exit lens 1040b is configured to receive light rays reflected by the second TIR surface 1008b, and the third exit lens 1040c is configured to receive light rays reflected by the third TIR surface 1008c. This alignment provides precise control of the light pattern generated by the optical element for each light source and its corresponding entrance portion 1006a-c and TIR surface 1008a-c. Alternatively or additionally, multiple exit lenses may be provided for a single light source, corresponding entrance portion, and / or TIR surface while maintaining the above-described technical effect.

[0077] The first exit lens 1040a and the third exit lens 1040c are configured to diffuse a portion of the light rays 1000 that exit the optical element through the first or third exit lens. The second exit lens is configured to collimate a portion of the light rays 1000 that exit the optical element through the second exit lens. As described above, light rays traveling from the first entrance portion 1006a generally reach the first exit lens 1040a, and a portion of them are reflected by the first TIR surface 1008a. Light rays traveling from the second entrance portion 1006b generally reach the second exit lens 1040b, and a portion of them are reflected by the second TIR surface 1008b. Light rays traveling from the third entrance portion 1006c generally reach the third exit lens 1040c, and a portion of them are reflected by the third TIR surface 1008c. Thus, a portion of the light rays exiting the optical element are exposed to diffusing exit lenses 1040a, 1040c, and a portion of the light rays are exposed to collimating exit lens 1040b. There may be one or more of each type of exit lens (diffusing or collimating), and their exact number and arrangement may be selected based on the desired light pattern. The arrangement shown in Figure 10, with diffusing exit lenses at the edges and collimating between them, provides a light pattern relatively similar to that shown in Figure 19.

[0078] The collimating and diverging functions of the exit lenses 1040a-c are provided by their Fresnel structures 1024. Each of the exit lenses 1040a-c comprises a plurality of Fresnel structures. The first exit lens 1040a comprises a plurality of Fresnel structures 1024 configured to diverge light rays exiting the optical element through the first exit lens. The second exit lens 1040b comprises a plurality of Fresnel structures configured to collimate light rays exiting the optical element through the second exit lens. The third exit lens 1040c comprises a plurality of Fresnel structures configured to diverge light rays exiting the optical element through the third exit lens. While FIG. 10 illustrates collimation and divergence in the horizontal direction x, the exit lenses may further collimate and / or diverge light rays in a vertical direction extending perpendicular to the directions x and z in the drawing.

[0079] The light cutter 1004 is also shown in Figure 10. The focal points 1030a-c of the TIR surfaces 1008a-c coincide with the tip of the light cutter 1004, providing a sharp cutoff in the light pattern. The light cutter 1004 includes a transition portion 1050 for creating an asymmetric light pattern along the x-direction, which is particularly suitable for left- or right-hand driving headlamps.

[0080] 11 shows the fifth embodiment from another angle, further illustrating the shape of the optical cutter 1004. The optical cutter 804 in FIG. 8 and the optical cutter 1004 in FIG. 10 have similar shapes, but other shapes, such as that shown in FIG. 3, are also suitable. Those skilled in the art can design the shape of the optical cutter of any embodiment according to the desired light pattern requirements.

[0081] 12 shows a high beam variation of the fifth embodiment. Optical element 1202 lacks an optical cutter, and therefore does not form a sharp cutoff profile for light rays passing from entrance portions 1206a-c to exit lenses 1240a-c. Optical element 1202 otherwise has the features described in connection with the fifth embodiment.

[0082] Next, different types of Fresnel structures will be described with reference to sixth, seventh, eighth, ninth and tenth embodiments of the optical element. The Fresnel structures shown and described in relation to these embodiments are also compatible with all other embodiments of the optical element. The Fresnel structures offer a high degree of freedom for designing optical systems for different configurations.

[0083] FIG. 13 illustrates a sixth embodiment of an optical element 1302. The optical element includes an entrance portion 1306 and an exit lens 1340. The exit lens includes a plurality of horizontally and vertically stacked vertical Fresnel structures 1324a, 1324b. The vertical Fresnel structures are rectangular in shape when viewed from the front. The upper Fresnel structures 1324a are horizontally stacked or adjacent to each other, and the lower Fresnel structures 1324b are horizontally stacked or adjacent to each other. The upper Fresnel structures 1324a are vertically stacked or adjacent to the lower Fresnel structures 1324b. The optical element 1302 may otherwise be similar to that shown in FIG. 3.

[0084] Figure 14 shows a seventh embodiment of an optical element 1402. The optical element comprises an entrance portion 1406 and an exit lens 1440. The exit lens comprises a plurality of horizontally and vertically stacked Fresnel structures 1424. The Fresnel structures are rectangular, or optionally square, in shape when viewed from the front. The optical element 1402 may otherwise be similar to that shown in Figures 3 and 13.

[0085] A rectangular or square Fresnel structure is useful for producing similar (ie, rectangular or square) shaped light patterns.

[0086] FIG. 15 shows an eighth embodiment of an optical element 1502. The optical element comprises an entrance portion 1506 and an exit lens 1540. The exit lens comprises a plurality of ring-shaped Fresnel structures 1524. The Fresnel structures take the shape of complete and / or incomplete rings when viewed from the front, as shown in FIG. 15. The optical element 1502 may otherwise be similar to those shown in FIGS. 3, 13, and 14. Ring-shaped Fresnel structures may be particularly well-suited for high beam configurations due to their optical properties.

[0087] FIG. 16 illustrates a ninth embodiment of an optical element 1602. The optical element includes multiple entrance sections 1606a-c and multiple exit lenses 1640a-c, one for each entrance section. The optical element includes two different types of Fresnel structures: the first exit lens 1640a and the third exit lens 1640c include horizontally stacked vertical Fresnel structures 1624a, 1624c, while the second exit lens 1640b includes horizontally and vertically stacked square Fresnel structures 1624b. These Fresnel structures 1624b are similar to those in FIG. 14, although smaller in size and therefore of a different type. This allows for precise control of the light pattern. In other respects, the optical element 1602 may be similar to those illustrated in FIGS. 10 and 11.

[0088] In general, a Fresnel structure may refer to a lens segment that is translated along the longitudinal direction z of the lens to achieve a reduced lens thickness. Any Fresnel structure used to form a Fresnel lens is suitable for use as a Fresnel structure in any embodiment. In this sense, the exit lenses having the Fresnel structures described herein may be considered Fresnel lenses. They achieve similar optical properties as regular lenses related to forming a desired light pattern, but within a smaller space along the longitudinal direction z. The Fresnel structure may have curved and / or flat surfaces. These surfaces refer to the light-emitting surfaces of the Fresnel structure of the exit lens.

[0089] FIG. 17 illustrates a tenth embodiment of an optical element 1702 having two different types of Fresnel structures. The optical element 1702 includes multiple entrance portions 1706a-c with corresponding multiple exit lenses 1740a-c at the exit portions of the optical element. The first exit lens 1740a includes a first multiple Fresnel structures 1724a, the second exit lens 1740b includes a second multiple Fresnel structures 1724b, and the third exit lens 1740c includes a third multiple Fresnel structures 1724c. In this embodiment, the first multiple Fresnel structures 1724a and the third multiple Fresnel structures 1724b are of the same type, and the second multiple Fresnel structures 1724b are of a different type than the first and third multiple Fresnel structures. In this case, all of the Fresnel structures shown are vertical Fresnel structures stacked horizontally and vertically, similar to those shown in FIG. 13. However, the second plurality of Fresnel structures has a different horizontal pitch or spacing, i.e., the Fresnel structures have different sizes in the horizontal direction and are therefore of different types. More specifically, the second plurality of Fresnel structures is narrower in the horizontal direction than the first and third plurality of Fresnel structures. This allows for more precise control of the overall light pattern of the optical element, as different types of Fresnel structures can be used to assign different effects to each exit lens, or even within a single exit lens. Optical element 1702 can otherwise be similar to those shown in FIGS. 10, 11, and 16.

[0090] FIG. 18 illustrates an eleventh embodiment of an optical element 1802. The optical element 1802 includes a plurality of entrance portions 1806a-c with a corresponding plurality of exit lenses 1840a-c at the exit portions of the optical element. The optical element is otherwise similar to the tenth embodiment, but lacks the Fresnel structure described above and shown in FIG. 17; i.e., the exit lenses 1840a-c do not have a Fresnel structure. The effect of the Fresnel structure of the tenth embodiment will now be described using simulated light patterns generated for the tenth and eleventh embodiments.

[0091] FIG. 19 shows a simulated light pattern for the tenth embodiment, and FIG. 20 shows a simulated light pattern for the eleventh embodiment. Both embodiments are capable of producing a light pattern with a cutoff near zero degrees vertically and a bright central beam near zero degrees horizontally, as well as an asymmetric light pattern for right-hand traffic due to the shape of the light cutter, as described in connection with FIG. 10. However, the tenth embodiment with a Fresnel structure can be used to produce a light pattern that is significantly wider than the eleventh embodiment. The Fresnel structure allows for the diffusion of light rays at higher angles of incidence compared to a single surface. To optimize the light pattern, the diffusion and / or collimation provided by different types of Fresnel structures may be used alone or in combination with an exit lens without a Fresnel structure.

[0092] Although the embodiments shown in Figures 13-18 are shown as low beam variations (ie, with optical cutters), they may also be implemented as high beam variations (ie, without optical cutters).

[0093] Figures 21 and 22 show various configurations of focal points within an optical element. In Figure 21, an optical axis 2100 extends from a TIR surface (not shown) at the left end of the optical axis to an exit lens (not shown) at the right end of the optical axis. The optical axis extends along the longitudinal direction z of the optical element.

[0094] Point 2102 along the optical axis may represent the focal point of the exit lens. Alternate locations 2104, 2106, 2108 of the focal points of the TIR surface are shown along the optical axis. The first alternate focal point 2104 is between the focal point of the exit lens 2102 and the TIR surface, i.e., translated or offset along the optical axis from the focal point of the exit lens toward the TIR surface. The second alternate focal point 2106 coincides with the focal point of the TIR surface. The third alternate focal point 2108 is between the focal point of the exit lens 2102 and the exit lens, i.e., translated or offset along the optical axis from the focal point of the exit lens toward the exit lens.

[0095] Alternatively or additionally, point 2102 may represent the location of an optical cutter or its tip, in which case similar alternative focal points 2104, 2106, 2108 are applicable.

[0096] Because the above discussion is applicable to focusing light in both directions performed by TIR, Figure 21 shows two alternative directions, x and y, perpendicular to the longitudinal direction z. The focus considerations discussed above are also applicable when the TIR surface has multiple foci, for example, a first vertical focus for focusing light rays in the vertical direction y, and a second horizontal focus for focusing light rays in the horizontal direction x. The two foci may be at the same location or at different locations. For example, they may be:

[0097] Both foci coincide with one of the alternative foci 2104 and 2108. One focus coincides with the alternative focus 2106, and the other focus coincides with the alternative focus 2104 or 2108. One focus coincides with the alternate focus 2104 and the other focus coincides with the alternate focus 2108. - Both foci coincide with the alternative focus 2106.

[0098] In the second and third alternatives outlined above, the first focal point of the TIR surface is at a different location along the optical axis of the TIR surface than the second focal point of the TIR surface.

[0099] In a preferred configuration, the vertical focus coincides with alternate focus 2106 and the horizontal focus coincides with alternate focus 2104 or 2108, where point 2102 is the focus of the exit lens (and optionally the position of the optical cutter). As explained in connection with Figure 1, this produces a precise cutoff light pattern with thermal advantage when an optical cutter is present. The positions of the vertical and horizontal focuses may be interchanged while maintaining the thermal advantage.

[0100] In another preferred configuration, the vertical focus coincides with the alternate focus 2104 or 2108, and the horizontal focus coincides with the other of the alternate focuses 2104 and 2108. Point 2102, which is also the focus of the exit lens (and optionally the location of the optical cutter), is between the two foci. Again, a thermal advantage is achieved due to the spreading of thermal peaks within the optical element. The positioning of the foci is particularly useful when an optical cutter is present, as neither focus coincides with the optical cutter, protecting it from the peak thermal load.

[0101] The focal point of the TIR 2104, 2108 not coinciding with the focal point of the exit lens has the effect of increasing the uniformity and width of the resulting light pattern.

[0102] Figure 22 shows a further configuration of focal points within an optical element. Similar to Figure 21, an optical axis 2100 extends from a TIR surface (not shown) at the left end of the optical axis to an exit lens (not shown) at the right end of the optical axis. The optical axis extends along the longitudinal direction z of the optical element. A point 2102 along the optical axis may represent the focal point of the exit lens and / or the location of the optical cutter or its tip.

[0103] FIG. 22 further illustrates a second optical axis 2200 of the TIR surface. The first focus (horizontal or vertical) may be along the first optical axis 2100 at one of the alternate foci, as described in connection with FIG. 21 . The second focus (the other of the horizontal or vertical focuses) may be along the second optical axis 2200 at one of the alternate foci 2204, 2206, or 2208. The first alternate focus 2204 is between point 2102 and the TIR surface but is along the second optical axis 2200 (i.e., offset from the optical axis 2100); the second alternate focus 2206 is the same distance from the TIR surface along the longitudinal direction z as point 2102 and is offset from the optical axis 2100; and the third alternate focus is between point 2102 and the exit lens and is offset from the optical axis 2100. The second optical axis 2200 is at a non-zero angle with respect to the first optical axis 2100.

[0104] 21, FIG. 22 shows two alternative directions x and y perpendicular to the longitudinal direction z. Considering the vertical direction y, the focal point considered is preferably a horizontal focal point for focusing light rays in the horizontal direction x. Considering the horizontal direction x, the focal point considered is preferably a vertical focal point for focusing light rays in the vertical direction y. Both the horizontal and vertical focal points of the TIR surface may be offset from the optical axis 2100 and may be on the same or different alternative optical axes 2200.

[0105] The alternative focus 2208 is offset (forward) along the second optical axis, towards the exit lens. In particular, considering the horizontal direction x as the axis shown in the figure, this alternative focus provides a more uniform light pattern, especially when two headlights with such optical elements are used in combination.

[0106] The focal configuration applied to each TIR surface of the optical element and the exit lens and / or light cutter may be the same or different from one or more of the other configurations of the optical element. These different configurations are compatible with all of the embodiments disclosed herein. The positioning of the focal point may be performed by the shaping of the TIR surface and the relative distance between the TIR surface and the light cutter and / or exit lens.

[0107] FIG. 23 shows a side view of a twelfth embodiment of an optical element 2302. The optical element comprises an entrance portion 2306 and a TIR surface 2308, an optical cutter 2304, and an exit portion 2380 having an exit lens 2340 with multiple Fresnel structures 2324. The TIR surface 2308 includes multiple facets 2360. The facets deviate from the curvature of a faceted TIR surface and may be flat or, preferably, curved. The curved facets may be convex (as shown in FIG. 23) and / or concave when viewed from outside the optical element. The entire TIR surface may be faceted, or the facets may cover one or more portions of the TIR surface, leaving one or more additional portions of the TIR surface unfaceted. The facets may be used to shift the focus of the TIR surface (relative to a non-faceted TIR surface), and the shape and curvature of the facets may be used to fine-tune the location of the focus. By shifting the focal point closer to the TIR surface, a shorter, and therefore more compact, optical element may be created. Shifting may also be used to position the focal point so that it coincides (or does not coincide) with the focal point of the optical cutter 2304 and / or the exit lens 2340; the technical effects of these options have been described above. Each facet contributes to the light pattern of the optical element, and such facets may be used to achieve very precise control of the light pattern. Otherwise, the optical element 2302 may have the same features as the optical elements shown in FIGS. 3, 4, 5, or other embodiments described herein.

[0108] FIG. 24 shows a top view of a thirteenth embodiment of an optical element 2402. Similar to the embodiment shown in FIGS. 10-12, the optical element 2402 includes a plurality of entrance portions 2406a-c with a corresponding plurality of TIR surfaces 2408a-c. The optical element 2402 further includes an exit portion having a plurality of exit lenses 2440a-c with a Fresnel structure 2424. Similar to the twelfth embodiment, the plurality of TIR surfaces 2408a-c include a plurality of facets 2460. Alternatively, one or more of the TIR surfaces may include a plurality of facets, or one or more of the TIR surfaces may be facetless. Details and advantages of the facets have been discussed above in connection with the twelfth embodiment. Otherwise, the optical element 2402 may have the same features as the optical element shown in FIGS. 10-12. The view of FIG. 23 may be considered a side view of the embodiment of FIG. 24.

[0109] The effect of faceting is illustrated in Figures 25 and 26, which show simulated light patterns produced by two TIR surfaces with the same spheroidal shape. The TIR surface used to produce the light pattern of Figure 25 has no facets, while the TIR surface used to produce the light pattern of Figure 26 is entirely faceted. Both of these TIR surfaces are suitable for use in any of the embodiments described herein. As seen in Figures 25 and 26, facets can be used to increase horizontal dispersion within the optical element and thus achieve a wider main beam. Furthermore, thermal benefits can be achieved as previously described with respect to the focus of the TIR surface and the location of the optical cutter.

[0110] FIG. 27 shows a side view of a fourteenth embodiment of an optical element 2702. The optical element 2702 is similar to other embodiments, such as those shown in FIGS. 3-5 , 13-15 , and 23 , in that it comprises an entrance portion 2706, a TIR surface 2708, a light cutter 2704, and an exit portion 2780 comprising an exit lens 2740 having multiple Fresnel structures 2724 a, 2724 b. Additionally, the optical element comprises a focusing surface 2770 for receiving light rays from the light cutter 2704. As described in connection with FIG. 1 , the light cutter comprises a TIR surface 2710 that reflects light arriving from the TIR surface 2708 and / or light arriving directly from the entrance portion 2706. The focusing surface then reflects the light rays by TIR toward the exit lens 2740. These light rays would otherwise be lost from the light pattern, and therefore, their preservation increases the efficiency of the optical element. Here, the collection surface 2770 is configured to collimate the light rays received from the light cutter in the vertical direction y such that they are perpendicular to the vertical direction y.

[0111] The exit lens 2740 comprises a first Fresnel structure 2724a configured to tilt the first light rays exiting the optical element. The first light rays are primarily reflected by the collection surface 2770. The exit lens comprises a second Fresnel structure 2724b configured to collimate the second light rays exiting the optical element. The second light rays are primarily arriving from the entrance portion 2706 directly or from the TIR surface 2708. An alternative optical element with a reduced height (in the vertical direction y) has a flat top whereby the optical element extends only as far as the path of the top-most light ray 2700 reflected by the collection surface 2770 toward the exit lens 2740. The flat top may extend along the path of the top-most light ray 2700 depicted in FIG. 27 . This optical element is otherwise similar in appearance and performance to optical element 2702 shown in FIG. 27, but has the portion above the top light beam 2700 truncated to achieve a more compact design without significantly affecting the resulting light pattern.

[0112] Figure 28 shows a fifteenth embodiment of an optical element 2802. The optical element is similar to the fifth embodiment of Figures 10 and 11 and includes a plurality of entrance portions 2806a-c with a corresponding plurality of TIR surfaces 2808a-c. The optical element 2802 further includes an exit portion 2880 having a plurality of exit lenses 2840a-c with corresponding Fresnel structures 2824a-c. The optical element includes an optical cutter 2804 with a TIR surface 2810 that reflects light arriving from the TIR surfaces 2808a-c and / or light arriving directly from the entrance portions 2706a-c.

[0113] Similar to the embodiment of FIG. 27, optical element 2802 further includes focusing surfaces 2870a-c, one at each of the entrance portion and / or TIR surfaces, for receiving the light rays from light cutter 2804. Light rays travel through the embodiment of FIG. 28 as shown in FIG. 27, which may be considered a side view of the embodiment of FIG. 28. Light rays exit optical element 2802 via exit lenses 2840a-c and their Fresnel structures 2824a-c. As discussed in connection with FIG. 27, alternative optical elements having flat tops (i.e., in which the upper portions of the topmost light rays reflected by focusing surfaces 2870a-c toward exit lenses 2840a-c are cut off) may be implemented for a more compact design without significantly affecting the resulting light pattern.

[0114] Various properties of the TIR surfaces described herein, such as the location of the facets and / or focal points, may be applied to the collection surface in addition to or instead of the TIR surface, providing similar benefits as when these properties are applied to the TIR surface.

[0115] FIG. 29 illustrates a sixteenth embodiment of an optical element 2902. The optical element includes an entrance portion 2906 and a corresponding TIR surface 2908. The optical element includes multiple optical cutters 2904a-b and multiple exit portions 2980a-b. A first optical cutter 2904a receives light rays directly from the entrance portion 2906 and / or from the TIR surface 2908. A first light ray 2900a passing through the first optical cutter exits the optical element via a first exit portion 2980a, more specifically, a first exit lens 2940a having a first Fresnel element 2924a. A second light ray 2900b reflected by a TIR surface 2910a of the first optical cutter 2904a travels to a focusing surface 2970 of the optical element. 27 and 28, the collecting surface 2970 reflects the light rays 2900b toward the second exit portion 2980b of the optical element. These second light rays 2900b exit the optical element through the second exit lens 2940b of the second exit portion. The second exit lens has a Fresnel structure 2924b, although either of the Fresnel structures 2924a or 2924b may be omitted.

[0116] Optical element 2902 further comprises a second optical cutter 2904b for forming a cutoff profile for second light ray 2900b, however, this optical cutter is optional and may be omitted if its cutoff profile is undesirable in the resulting light pattern.

[0117] Optical element 2902 further includes facets 2960 at collection surface 2970. As mentioned above, these facets may be similar to the facets of the TIR surface described in connection with the embodiments of Figures 23 and 24. Alternatively, facets may be provided on TIR surface 2908, or on both TIR surface 2908 and collection surface 2970.

[0118] The optical element of Figure 29 may be implemented with a single inlet portion as shown in various other embodiments, or may otherwise have the properties of any of these embodiments. Alternatively, the optical element of Figure 29 may be implemented with multiple inlet portions, such as in the embodiments of Figures 6-12, 16-18, 24, or 28. The optical element may otherwise have the properties of any of these embodiments.

[0119] Additional exit sections may be added to the optical element of Figure 29 in a cascading manner, such that each exit section receives light rays through a collecting surface and a light cutter, as shown in Figure 29. Each exit section, collecting surface, and light cutter increases the efficiency of the optical element, as light reflected from a preceding exit section by a preceding light cutter is redirected toward another exit section by the corresponding collecting surface. A bright central beam is an advantage of all variations of the embodiment.

[0120] Exemplary simulations have shown an efficiency of 75-80% with the solution of Figure 29 alone. This can be compared to an efficiency of 45% for an equivalent optical element without a focusing surface or additional exit section. Both solutions can achieve the same cutoff light pattern.

[0121] FIG. 30 shows a simulated light pattern of the full beam of the sixteenth embodiment. This light pattern exhibits a cutoff near zero degrees vertical and a slight asymmetry for right-hand traffic due to the desired shape of the optical cutter, an example of which is provided in connection with FIG. 10 . The light pattern is formed as the sum of an upper and lower beam, where the lower beam is formed by a first light ray 2900a exiting the optical element 2902 via a first exit portion 2980a, and the upper beam is formed by a second light ray 2900b exiting the optical element 2902 via a second exit portion 2980b (see FIG. 29 ). FIG. 31 shows the simulated light pattern of the lower beam of the sixteenth embodiment, and FIG. 32 shows the simulated light pattern of the upper beam of the sixteenth embodiment. The figures demonstrate that the upper beam significantly contributes to the overall light pattern, both its size and shape. The focusing surface is thus able to recover rays that might otherwise be lost, and the recovered rays can be further targeted by the exit lens through which they exit the optical element. Separate exit sections for these rays allow flexibility in controlling the rays, for example, with a light cutter, as shown in Figure 29.

[0122] FIG. 33 illustrates a vehicle headlamp 3300 having an optical element according to a seventeenth embodiment. The headlamp 3300 may be implemented as a low beam headlamp with an appropriate light filter in the optical element, or as a high beam headlamp without such a light filter in the optical element. FIG. 34 illustrates a front view of the headlamp 3300. The illustrated headlamp includes a housing 3400, which is suitable for mounting in a vehicle, such as a work vehicle, using, for example, fasteners 3390a-c and / or 3392a-d.

[0123] The headlamp 3300 includes multiple LED light sources, one for each of the three entrance sections of the optical element (not shown). The optical element features hidden from view in Figures 33 and 34 may be implemented, for example, as in any of the embodiments of Figures 6-12, 16-18, 24, and 28. The optical element according to the seventeenth embodiment includes multiple horizontally adjacent exit lenses 3340a-c. Two exit lenses 3340a, 3340c include respective Fresnel structures 3324a, 3324c. The intermediate exit lens 3340b does not have a Fresnel structure. The configuration of the exit lenses of the embodiment, more specifically, the Fresnel structures of the exit lenses on either side of the lens without a Fresnel structure, allows for reduced scattered or stray light. Alternatively, horizontally and / or vertically adjacent exit lenses, with or without Fresnel structures, may be implemented in some or all of the four quadrants of the intermediate exit lens 3340b shown in the figures to provide further control of the light pattern.

[0124] Any other optical elements are suitable for use in the headlamp 3300. For example, the optical elements of Figures 6-12, 16-18, 24, and 28 may be used. Alternatively, multiple optical elements may be used in the headlamp 3300. For example, as shown in the figures, three optical elements may be stacked horizontally, with a first optical element providing the exit lens 3340a, a second optical element without a Fresnel structure providing the exit lens 3340b, and a third optical element providing 3340c. Suitable optical elements include, for example, those shown in Figures 1-5, 13-15, 23, and 27.

[0125] The headlamp 3300 of Figures 33 and 34 has a compact construction. For example, the optical element (and, by extension, other optical elements described herein) may be 10 millimeters (mm) high in the vertical direction y and 30 mm wide in the horizontal direction x. The headlamp 3300 may be 60 mm wide in the horizontal direction x and 25 mm high in the vertical direction y, excluding the flanges of the fixtures 3390a-d from the measurements.

[0126] When implemented as a low beam headlamp, the headlamp 3300 shown in Figures 33 and 34 can achieve a simulated optical efficiency of 44% using optical elements made of PMMA, or a simulated optical efficiency of 28% using optical elements made of PC.

[0127] Although some embodiments of the optical element have been shown and described with one or three entrance portions, the optical element may have any number of entrance portions, and there may be a corresponding number of other portions of the optical element (such as the TIR surface) and headlamp (such as the light source).

[0128] All of the following configurations are contemplated for the Fresnel structure, which can be configured to perform the following on the light rays:

[0129] -Collimate only in the horizontal x direction, - collimated in the vertical direction y only, collimating in both the horizontal x-direction and the vertical y-direction, - Diffuse only in the horizontal direction x, - Diffuses only in the vertical direction y, - Diffuse in both the horizontal x direction and the vertical y direction, - Diffuse in the vertical direction y and collimate in the horizontal direction x, or -Collimates in the vertical direction y and diffuses in the horizontal direction x.

[0130] Where appropriate, various functions described herein may be performed in a different order and / or concurrently with other functions. Further, where appropriate, one or more of the above functions and embodiments may be present or combined as desired.

[0131] Although various aspects of the embodiments are set out in the independent claims, other aspects include other combinations of features from the described embodiments and / or dependent claims with features of the independent claims, and not just the combinations explicitly set out in the claims.

[0132] It should also be noted here that while the above describes exemplary embodiments, these descriptions should not be construed in a limiting sense. Rather, there are several variations and modifications that can be made without departing from the scope of the present disclosure, as defined in the appended claims.

Claims

1. An optical element (102) for a vehicle headlamp (100), said optical element comprising: one or more entrance portions for receiving light rays from one or more light sources (120); one or more total internal reflection (TIR) ​​surfaces (108) configured to receive light rays from the one or more entrance portions and to focus the light rays received from the one or more entrance portions in a vertical (y) and horizontal (x) direction by TIR; one or more exit portions (180) comprising one or more exit lenses (140), the one or more exit lenses comprising a plurality of Fresnel structures configured to collimate and / or diffuse light rays exiting the optical element in the horizontal direction and / or the vertical direction; Equipped with The optical element (102), wherein the optical element is formed as a monolithic body.

2. 2. The optical element of claim 1, wherein the optical element comprises one or more optical cutters (104, 304, 404, 804, 1004, 2304, 2804) configured to shape a cutoff profile of light rays passing from the one or more entrance portions to the one or more exit lenses by TIR.

3. the optical element comprises one or more focusing surfaces (2770, 2870a, 2870b, 2870c, 2970) configured to receive light rays reflected by the one or more light cutters and reflect the light rays received from the one or more light cutters towards the one or more exit lenses by TIR; and optionally at least one of the one or more focusing surfaces (2770, 2870a, 2870b, 2870c, 2970) configured to collimate the light beam received from the one or more light cutters towards the one or more exit lenses; and / or 3. The optical element of claim 2, wherein at least one of the one or more focusing surfaces (2770, 2870a, 2870b, 2870c, 2970) is configured to focus the light rays received from the one or more optical cutters in the vertical and horizontal directions.

4. the optical element comprises a plurality of light cutters (2904a, 2904b) and a plurality of exit portions (2980a, 2980b); a first one or more light cutters (2904 a) of the plurality of light cutters are arranged to form a cutoff profile for light rays received from the one or more entrance portions and / or from the one or more TIR surfaces, and configured to exit the optical element via a first one or more exit portions (2980 a) of the plurality of exit portions; 4. The optical element of claim 3, wherein a second one or more optical cutters (2904b) of the plurality of optical cutters are arranged to form a cutoff profile of the light rays received from the one or more focusing surfaces and are configured to exit the optical element through a second one or more exit portions (2980b) of the plurality of exit portions.

5. 5. The optical element of any one of claims 1 to 4, wherein the one or more TIR surfaces and / or the one or more focusing surfaces comprise a plurality of flat and / or curved facets (2360, 2960).

6. The plurality of Fresnel structures are a ring-shaped Fresnel structure (1524), and / or Horizontally and / or vertically stacked rectangular Fresnel structures (1324a, 1324b, 1424, 1624a, 1624b, 1624c, 1724a, 1724b, 1724c) The optical element according to any one of claims 1 to 5, comprising:

7. The optical element according to any one of claims 1 to 6, wherein the one or more exit portions comprise one or more exit lenses (3340b) without a Fresnel structure.

8. The optical element according to any one of claims 1 to 7, wherein the plurality of Fresnel structures comprises at least two different types of Fresnel structures (1624a, 1624b, 1624c).

9. at least one TIR surface of the one or more TIR surfaces has a first focus and a second focus for focusing the light rays received from the one or more entrance portions, the first focus and the second focus substantially coinciding; or 9. An optical element according to any one of claims 1 to 8, wherein the first focus and the second focus do not coincide, and optionally one of the first focus and the second focus is positioned farther from the at least one TIR surface than the other of the first focus and the second focus, and / or the first focus and the second focus are at different positions in the horizontal direction.

10. 10. The optical element of any one of claims 1 to 9, wherein the one or more exit lenses comprise a plurality of exit lenses comprising a plurality of the Fresnel structures.

11. 11. The optical element of claim 1, wherein the optical element comprises a plurality of entrance portions (606a, 606b, 606c, 1006a, 1006b, 1006c) for receiving light rays from the one or more light sources, and a plurality of TIR surfaces (608a, 608b, 608c, 1008a, 1008b, 1008c) configured to receive the light rays from the plurality of entrance portions and to focus the light rays received from the plurality of entrance portions in the vertical direction (y) and the horizontal direction (x) by TIR.

12. The optical element of claim 11 , wherein the plurality of TIR surfaces (1008a, 1008b, 1008c) comprise substantially parallel optical axes for focusing the light rays.

13. 13. The optical element of claim 11 or 12, wherein the plurality of TIR surfaces (608a, 608b, 608c) comprise substantially non-parallel optical axes for focusing the light rays (600, 700).

14. the one or more exit lenses comprise a plurality of exit lenses (1040a, 1040b, 1040c); 14. An optical element according to any one of claims 11 to 13, wherein the plurality of exit lenses comprises at least one exit lens for each of the plurality of TIR surfaces and / or a plurality of horizontally and / or vertically adjacent exit lenses (1040a, 1040b, 1040c).

15. An optical element according to any one of the preceding claims, wherein at least one of the one or more exit portions comprises only one of the one or more exit lenses (640, 740, 840, 940, 1340, 1440, 1540).

16. 16. The optical element of any one of claims 1 to 15, wherein the plurality of Fresnel structures of at least one of the one or more exit lenses comprises a first Fresnel structure configured to collimate light rays exiting the optical element and a second Fresnel structure configured to diffuse light rays exiting the optical element.

17. 17. The optical element of any one of claims 1 to 16, wherein the Fresnel structures of at least one of the one or more exit lenses are configured to spread light rays exiting the optical element at two or more different divergence angles.

18. An illumination unit comprising one or more light sources (120) and one or more optical elements (102) according to any one of claims 1 to 17.

19. A vehicle comprising a lighting unit according to claim 18.

Images