An optical module having a lens that displays the illuminated surface of the light concentrator and a screen that blocks stray light and direct rays.
The light-emitting module with a reflective surface and screen near the light source addresses manufacturing challenges by reducing height and weight, enhancing optical functionality and blocking direct rays.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- VALEO VISION SA
- Filing Date
- 2026-04-02
- Publication Date
- 2026-06-23
Smart Images
Figure 2026102961000001_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical fields of lighting and signaling, and more particularly to applications in the field of motor vehicles.
Background Art
[0002] It is generally known to create a cut-off lighting beam by using one or more light-emitting modules having a deflector. Such light-emitting modules conventionally include a condenser with a reflecting surface on a rotational surface having an elliptical profile. The condenser is shaped like a cap within the half-space bounded by the horizontal plane. A light-emitting diode-type light source, which is essentially a point source, is located at the first focus of the reflecting surface and emits light into the half-space in the direction of the surface. Thus, the light rays are reflected so as to converge towards the second focus of the reflecting surface. Another (generally flat) reflecting surface having a cut-off edge at the second focus ensures the upward reflection of the light rays that do not exactly pass through the second focus. And these light rays are refracted towards the bottom of the lighting beam by a thick lens. This reflecting surface is generally called a "deflector" in that it "bends" those light rays (which would otherwise form the upper part of the lighting beam) towards the top of the projection lens. Such light-emitting modules have the drawback of requiring high precision in the positioning of the deflector and the cut-off edge. Moreover, the projection lens has to be a thick lens due to its short focal length, which increases its weight and makes manufacturing difficult (especially in terms of sink marks). Also, the condenser has a considerable height and accordingly a considerable volume in the height direction.
[0003] Patent Document 1 (WO2020 / 025171A1) discloses a light-emitting module (particularly for use in automobiles). The module, like a light-emitting module with a bender, includes a concentrator having a reflective surface that focuses and reflects light rays emitted from a light source into a light beam. The light-emitting module also includes a projection optical system, specifically configured to project the light beam by forming an image of the reflective surface of the concentrator (e.g., a lens). For this purpose, the projection optical system has a focal point located on the reflective surface, for example, at the rear edge of the reflective surface. This is to accurately project (image) the edge, forming a sharp cut in the projected light beam. However, certain light rays emitted from the light source that are not reflected by the reflective surface of the concentrator may reach the projection optical system and degrade the projected light beam. For this purpose, a screen (a shield) is provided, positioned in front of the light source. This teaching does not address the manufacture of screens or shields, particularly in the context of industrial applications. [Prior art documents] [Patent Documents]
[0004] [Patent Document 1] International Publication No. 2020 / 025171 brochure [Overview of the project]
[0005] The aim of the present invention is to mitigate at least one of the drawbacks of the prior art described above. Specifically, the objective of the present invention is to provide industrially usable applications for screens based on the prior art that exhibit superior optical functionality.
[0006] The subject of this invention is a light source capable of emitting light rays, a plate supporting the light source, and a device that focuses and reflects light rays. A light-emitting module comprising: a light-gatherer having a reflective surface configured to form a reflected light beam along the optical axis; an optical system configured to project the reflected light beam by reflecting a portion of the reflective surface; and a screen located in front of the light source along the main direction of propagation of the reflected light beam and configured to capture rays of light called direct rays arriving directly from the light source, wherein the screen extends along the lateral direction with a constant cross-section and is arranged on a plate.
[0007] "Direct rays" should be understood as rays that would reach the light-receiving surface of the optical system directly if there were no screen; in other words, rays that would reach the light-receiving surface of the optical system without being deflected beforehand by optical elements (especially reflective surfaces). These direct rays (especially those emitted parallel or nearly parallel to the optical axis) may result in a light beam that is projected without being shaped by the light-gatherer or reflective surface if there is no screen, which is undesirable.
[0008] It is advantageous for the light concentrator and reflective surface to have a cap or hemispherical shape. It is advantageous for the reflective surface to have an elliptical or parabolic profile that exhibits rotational symmetry about an axis parallel to the optical axis.
[0009] According to an advantageous embodiment of the present invention, the lateral direction is perpendicular to the optical axis.
[0010] According to an advantageous embodiment of the present invention, the screen has a convex end face on the side opposite to the plate. The end face may also be referred to as an end region. This end face (or end region) corresponds to the side of the screen opposite to the side of the screen facing the plate. As will be seen below, the end face (or end region) may be continuous or have multiple faces or portions separated by edges.
[0011] According to an advantageous embodiment of the present invention, the end face of the screen has a transverse profile comprising a curved portion with a radius of curvature r of 0.1 mm or more and / or a straight portion inclined at least 10° toward the rear and toward the plate. The profile is oriented to traverse the principal direction of the screen, which corresponds to the transverse direction, meaning that the profile lies in a longitudinal plane parallel to the optical axis.
[0012] According to an advantageous embodiment of the present invention, the screen has a rear surface that directly captures light rays, and the rear surface is located at a distance d of 10 mm or less, preferably 4 mm or less, from the light source along the optical axis. The distance d is advantageously measured between the front edge of the light source and the rear edge of the rear surface of the screen.
[0013] According to an advantageous embodiment of the present invention, the rear surface of the screen is part of the end surface of the screen. In particular, all or part of the rear surface of the screen may be part of the end surface of the screen. In that case, at least a portion of the rear surface forms a portion of the end surface.
[0014] The portion of the rear surface that forms part of the end face may form a continuous surface with the rest of the screen's end face (i.e., the portion of the rear surface is not separated from the rest of the end face by an edge).
[0015] Alternatively, the portion of the rear surface forming a part of the screen's edge may be separated from the rest of the screen's edge by a ridge. In this case, the edge may have one or more ridges separating different surfaces or parts.
[0016] According to an advantageous embodiment of the present invention, the cross-section of the screen is triangular, circular, oval (including flattened circular shapes such as elliptical and egg shapes), or pentagonal.
[0017] According to an advantageous embodiment of the present invention, the screen is made of a metallic material.
[0018] According to an advantageous embodiment of the present invention, the screen is attached to the plate by welding, brazing, and / or adhesive bonding.
[0019] According to an advantageous embodiment of the present invention, the screen is not subjected to a light-reflecting and / or light-absorbing surface treatment.
[0020] The solution of the present invention is advantageous in that it enables the screen to be placed in the vicinity of the light source, thereby making it possible to reduce the dimensions (particularly the height) of the screen. This means that the light rays of the reflected light beam are not blocked, and the plate does not extend forward beyond the screen, nor does the cooling radiator for the light source extend similarly on the lower side of the plate (i.e., on the surface opposite to the side supporting the light source). The solution of the present invention is also advantageous from an industrialization perspective. It is in that a screen can be cut out from a bar having a desired cross-section, and it is possible to fixedly attach the screen as desired on various types of plates.
Brief Description of the Drawings
[0021] [Figure 1] Schematic depiction of the light-emitting module according to the first embodiment of the present invention as seen from the side. [Figure 2] Schematic depiction of the light-emitting module of FIG. 1 as seen from above. [Figure 3] Perspective explanatory view of the light source, screen, and condenser of the light-emitting module according to the first embodiment of the present invention as seen from the side. [Figure 4] Perspective explanatory view of the light source, screen, and condenser of the light-emitting module according to the second embodiment of the present invention as seen from the side. [Figure 5] Perspective explanatory view of the light source, screen, and condenser of the light-emitting module according to the third embodiment of the present invention as seen from the side.
Mode for Carrying Out the Invention
[0022] In the following description, the concepts of "front" and "back" relate to the main direction of propagation of light rays along the optical axis.
[0023] Figs. 1 to 3 show a light-emitting module according to a first embodiment of the present invention.
[0024] Fig. 1 is a schematic side view of the light-emitting module 2.
[0025] The light-emitting module 2 essentially comprises a light source 4, a plate 6 supporting the light source 4, a condenser 8 capable of reflecting the light rays emitted by the light source 4 to form a reflected light beam along the optical axis 10 of the module, and a projection lens 12 for projecting the beam. Projection optical systems other than the projection lens, particularly one or more reflecting mirrors, etc., are conceivable.
[0026] Here, generally according to the present invention, it is advantageous for the light source 4 to be of the semiconductor type, for example, particularly a light-emitting diode. In particular, the light source 4 emits light rays in a main direction perpendicular to the plane and the optical axis 10 within half of the space defined by the main plane of the light source.
[0027] The condenser 8 comprises a body 8.1 in the shape of a housing or a cap, and a reflecting surface 8.2 on the inner surface of the body 8.1. It is advantageous for the reflecting surface 8.2 to have an elliptical or parabolic profile. Its surface is advantageously a rotational surface around an axis parallel to the optical axis. As an alternative, it may be a free-form surface. Its surface may also have a plurality of parts. The condenser 8 in the shape of a housing or a cap is advantageously made of a material exhibiting excellent heat resistance, such as glass, or a synthetic polymer compound such as polycarbonate (PC) or polyetherimide (PEI).
[0028] The term "parabolic" generally refers to a reflector whose surface has a single focal point, that is, a single point where light rays converge, and where light rays emitted from a light source placed at this focal point are reflected from the surface and projected over long distances. "Projected over long distances" means that these light rays do not converge toward a point located at least 10 times the size of the reflector. In other words, the reflected light rays do not converge toward a single focal point, or if they do, this focal point is located at a distance of 10 times or more the size of the reflector. Therefore, a parabolic surface may or may not have a parabolic portion. Reflectors with such surfaces are particularly used to create light beams on their own.
[0029] The light source 4 is positioned at the focal point of the reflective surface 8.2 such that its rays are collected and reflected as a reflected light beam along the optical axis. At least some of these reflected rays have an inclination angle α of 10° or less with respect to the optical axis. This is to ensure that astigmatism-free (i.e., sharpness of the projected image) is achieved, thus meeting the so-called Gaussian condition. It is advantageous that these rays are reflected by the rear portion of the reflective surface 8.2.
[0030] It is advantageous for the projection lens 12 to be a biconvex lens, that is, having a convex light-receiving surface 12.1 and a convex light-emitting surface 12.2. The lens 12 is said to be thin (for example, less than 6 mm) because the slope of the light rays to be deflected is gentle. The lens 12 has a focal point 12.3 located at the light source 4 or behind the light source along the optical axis 10. In this case, the focal point 12.3 is located on the reflective surface 8.2 of the light condenser 8, more precisely, at its posterior edge (in this case, also the lower edge).
[0031] If the reflective surface is elliptical, it has a second focal point located in front of the lens 12 and at a distance from the optical axis 10. Note that this focal point can also be located behind the lens and / or on the optical axis (preferably near the lens) to reduce the beam width at the light-receiving surface of the lens.
[0032] The light-emitting module 2 is positioned in front of the light source 4 and includes a screen 14 facing the reflective surface 8.2 of the light concentrator 8. The screen 14 has a rear surface 14.2 that can collect direct rays 16 that are directly emitted forward by the light source 4 (i.e., do not hit the reflective surface 8.2). Such a measure is useful in avoiding the presence of parasitic rays that might be involved in the formation of the light beam (albeit not strictly imaged). These direct rays 16 (especially those parallel or nearly parallel to the optical axis 10) can then illuminate the upper portion of the light beam, which is undesirable in the case of a cutoff illumination beam.
[0033] Figure 2 is a schematic plan view of the light-emitting module 2 shown in Figure 1.
[0034] It can be seen that the screen extends along a lateral direction 14.1, which is preferably perpendicular to the optical axis 10 and parallel to the plate 6. The screen extends along the lateral direction 14.1 to block or capture direct rays that, without the screen 14, would reach the light-receiving surface 12.1 of the projection lens 12 and obstruct the projected light beam. As a result, these parasitic rays can be blocked. The screen has a constant cross-section along the lateral direction 14.1. In this case, the cross-section is pentagonal, more specifically a regular pentagon. One of the five sides of the pentagon is positioned on the plate 6, and two adjacent sides located at the rear of the screen, adjacent to the side positioned on the plate 6, form the rear surface 14.2 of the screen 14.
[0035] It is advantageous that the screen 14 is made from a metal and / or plastic material, particularly by extrusion molding. It is advantageous that its cross-section is flat, i.e., free from voids or cavities in the material.
[0036] It is advantageous that the rear surface 14.2 of the screen 12 is not subjected to any light-reflecting or light-absorbing surface treatment. The portion of the direct light rays 16 incident on the rear surface 14.2 and reflected is actually partially reflected toward the reflective surface 8.2 of the light concentrator 8 and partially toward the plate. The portion of the direct light rays 16 reflected toward the plate is mainly absorbed there. The portion of the direct light rays 16 reflected toward the reflective surface 8.2 of the light concentrator 8 is then reflected at an incident angle such that it is reflected forward at a distance from the lens 12. However, depending on various parameters, particularly the screen material and the overall geometric shape of the light-emitting module, it is possible to apply an absorbing or reflective optical treatment or coating to the rear surface 14.2. In the case of a reflective treatment or coating, it is conceivable to provide absorbing areas that can absorb the thus reflected direct light rays.
[0037] Figure 3 is a perspective view illustrating the light source, screen, and concentrator in the light-emitting module 2 shown in Figures 1 and 2, viewed from the side.
[0038] It can be seen that the distance d between the light source 4 and the screen 14 along the optical axis (not shown, but corresponding to the horizontal direction in Figure 3) has been shortened (preferably to 4 mm or less). This distance is measured between the front edge of the light source 4 and the rear edge of the screen (specifically, the rear edge of the rear surface 14.2 of the screen 14). This shortened distance provides an optical advantage in that the screen can capture and block direct rays while not blocking any of the light rays reflected by the reflective surface 8.2 of the light concentrator 8. Specifically, considering the left portion of Figure 3, by bringing the screen 14 closer to the light source 4, its height can be reduced, and based on this, the end face 14.3 on the opposite side of the plate (not shown in Figure 3) can be distanced from the light concentrator 8 and its reflective surface 8.2. This distance makes it possible to avoid any interference with reflected rays.
[0039] It can also be observed that the end face (also referred to as the end region) of the screen 14 has a convex profile. In this case, the surface comprises a curved portion 14.3.1 with a radius of curvature r, and two linear portions 14.3.2 and 14.3.3, respectively, inclined at angles β and γ with respect to the direction parallel to the optical axis. These two linear portions 14.3.2 and 14.3.3 are located on either side of the curved portion 14.3.1 (the latter being in the center). Thus, the end face 14.3 is formed by a continuous surface created by the curved portion 14.3.1 and the two linear portions 14.3.2 and 14.3.3.
[0040] The rear straight section 14.3.3 is part of the rear surface 14.2. In particular, the pentagonal edges located at the rear of the screen and not adjacent to the edges that are mounted on the plate form the rear straight section 14.3.3. Therefore, a part of the rear surface 14.2 of the screen is part of the end surface 14.3 of the screen.
[0041] The rear linear portion 14.3.3 is inclined by an angle γ toward the rear and toward the plate (not shown) by an angle of 10° or more, which is advantageous. The front linear portion 14.3.2 is inclined by an angle β toward the front and toward the plate (not shown). The radius of curvature r is preferably 0.1 mm or more and / or less than 1 mm. This radius of curvature r and angle γ make it possible to reflect direct light rays incident on the rear linear portion 14.3.3 and the curved portion 14.3.1 so that they do not reach the projection lens (not shown).
[0042] Figure 4 is a perspective view illustrating the light source, screen, and concentrator of a light-emitting module according to a second embodiment of the present invention, as seen from the side.
[0043] The reference numbers of the first embodiment are used to indicate corresponding or identical elements, but these numbers have been incremented by 100. The description of these elements will also be based on references within the context of the first embodiment of the present invention.
[0044] The light-emitting module 102 differs from the light-emitting module 2 of the first embodiment primarily in that the screen 114 has a triangular cross-section, which is no longer pentagonal. The triangular cross-section is preferably an equilateral triangle. The distance d between the light source 104 and the screen 114 along the optical axis (not shown, but corresponding to the horizontal direction in Figure 4) is similarly shortened (preferably to 4 mm or less).
[0045] The end face 114.3 of the screen 114 differs somewhat from that of the screen 14 of the first embodiment of the present invention in that the inclinations β and γ of the front linear portion 114.3.2 and the rear linear portion 114.3.3 are larger. The end face 114.3 is formed by a continuous surface formed by a curved portion 114.3.1 and two linear portions 114.3.2 and 114.3.3.
[0046] The rear surface 114.2 is also formed by a straight rear portion 114.3.3. Thus, the entire rear surface 114.2 of the screen is part of the end surface 114.3 of the screen.
[0047] This arrangement means that the portion of the direct light rays reflected by the rear surface 114.2 is entirely reflected towards the concentrator 8, in contrast to the first embodiment in which a portion is reflected towards the plate (not shown).
[0048] Figure 5 is a perspective view illustrating the light source, screen, and concentrator of a light-emitting module according to a third embodiment of the present invention, as seen from the side.
[0049] The reference numbers of the first embodiment are used to indicate corresponding or identical elements, but these numbers have been incremented by 200. The description of these elements also relies on references within the context of the first embodiment of the present invention.
[0050] The light-emitting module 202 differs from the light-emitting modules 2 of the first and second embodiments primarily in that the screen 214 has a circular cross-section that is no longer pentagonal or triangular. It should be understood that while the circular cross-section preferably has a constant radius around its entire circumference, this cross-section may also have some degree of flattening (particularly an elliptical shape). The distance d between the light source 204 and the screen 214 along the optical axis (not shown, but corresponding to the horizontal direction in Figure 5) is similarly shortened (preferably to 4 mm or less).
[0051] The end face 214.3 of the screen 214 is convex. This is essentially different from that of the screens 14 and 114 of the first and second embodiments of the present invention, in that this face comprises a single portion which in this case is a curved portion 214.3.1 (i.e., it has no straight portions). This curved portion has a radius of curvature r which can be considerably larger than the radius of curvature r of the curved portions 14.3.1 and 114.3.1 of the first and second embodiments of the present invention.
[0052] The rear surface 214.2 is also formed by a generally curved portion 214.3.1. Therefore, the entire rear surface 214.2 of the screen 214 is part of the end surface 214.3 of the screen 214. As in the first embodiment, and in contrast to the second embodiment, thanks to the curved shape of the rear surface 214.2, portions of the direct light rays reflected by the rear surface 214.2 are reflected towards the concentrator 208, and other portions are reflected towards the plate (not shown).
[0053] Generally (especially with respect to the three embodiments described above), the screen can be attached to the plate by welding, brazing, and / or adhesive bonding. It is advantageous for the screen to be made from a metallic material, particularly by extrusion. In this case, attachment by welding and / or brazing is particularly suitable. The required length can be cut from a rod having the desired cross-section (such as one of those presented above).
[0054] Generally speaking, it is advantageous for the screen's overall height (perpendicular to the optical axis) to be in the range of 0.5 to 5 mm.
[0055] It should be understood that shapes other than pentagonal, triangular, and circular are possible, as long as the rear surface can absorb or reflect these rays toward the plate and / or light condenser, so that the direct rays do not reach the projection optical system (in this case, the projection lens) even after they have been reflected by the reflective surface of the light condenser.
[0056] The light-emitting module of the present invention can be used to form a standard illumination light beam for an automated vehicle (for example, a low-beam illumination function and a high-beam illumination function). These functions are essentially well known to those skilled in the art.
Claims
1. - A light source capable of emitting light rays (4;104;204), - A plate (6) supporting the light source (4; 104; 204), - A light concentrator (8;108;208) having a reflective surface (8;2;108;2;208.2) configured to focus and reflect the aforementioned light rays to form a reflected light beam along the optical axis (10), - An optical system (12) configured to project the reflected light beam by reflecting a portion of the reflective surface (8.2; 108.2; 208.2), - A screen (14; 114; 214) located in front of the light source (4; 104; 204) along the main direction of propagation of the reflected light beam, configured to capture a ray referred to as a direct ray (16) arriving directly from the light source, Equipped with, The light-emitting module (2;102;202) is characterized in that the screen (14;114;214) extends along the lateral direction (14.1;114.1;214.1) with a constant cross-section and is arranged on the plate (6).
2. The light-emitting module (2; 102; 202) according to claim 1, wherein the lateral direction (14.1; 114.1; 214.1) is perpendicular to the optical axis (10).
3. The light-emitting module (2;102;202) according to claim 1 or 2, wherein the screen (14;114;214) has a convex end face (14.3;114.3;214.3) on the side opposite to the plate (6).
4. The light-emitting module (2;102;202) according to claim 3, wherein the end face (14.3;114.3;214.3) of the screen (14;114;214) has a transverse profile comprising a curved portion (14.3.1;114.3.1;214.3.1) with a radius of curvature r of 0.1 mm or more and / or a straight portion (14.3.3;114.3.3) inclined at least 10° toward the rear and toward the plate (6).
5. The light-emitting module (2;102;202) according to any one of claims 1 to 4, wherein the screen (14;114;214) has a rear surface (14.2;114.2;214.2) that captures the direct light rays (16), and the rear surface (14.2;114.2;214.2) is located at a distance d of 10 mm or less, preferably 4 mm or less, from the light source (4;104;204) along the optical axis (10).
6. The light-emitting module (2;102;202) according to claims 2 and 5, wherein the rear surface (14.2;114.2;214.2) of the screen (14;114;214) is part of the end surface (14.3;114.3;214.3) of the screen (14;114;214).
7. The light-emitting module (2; 102; 202) according to any one of claims 1 to 6, wherein the cross-section of the screen (14; 114; 214) is triangular, circular, oval, or pentagonal.
8. The light-emitting module (2; 102; 202) according to any one of claims 1 to 7, wherein the screen (14; 114; 214) is made of a metallic material.
9. The light-emitting module (2; 102; 202) according to any one of claims 1 to 8, wherein the screen (14; 114; 214) is attached to the plate (6) by welding, brazing, and / or adhesive bonding.
10. The light-emitting module (2; 102; 202) according to any one of claims 1 to 9, wherein the screen (14; 114; 214) is not surface-treated in a light-reflecting and / or light-absorbing manner.