WO2025132840A1 - Light unit for a motor vehicle - Google Patents

Abstract

The invention relates to a light unit comprising a support member (5) bearing a row (1) of light sources emitting light rays (1a) and an optical unit (6) comprising a primary lens (2) and a projection lens (3). The light sources are aligned in a horizontal alignment direction (D1). The primary lens comprises an input face (2a), an output face (2b) and a reflection surface (2c) which are positioned substantially vertically. The primary lens and the row of light sources are configured such that, after being emitted, light rays pass through the input face to then be reflected by the reflection surface towards the output face. The light rays passing through the projection lens are projected in the form of a beam having an average projection direction. The average projection direction is substantially parallel to the horizontal alignment direction.

Description

Description

LIGHT UNIT FOR MOTOR VEHICLE

TECHNICAL FIELD

[0001] The present invention relates to the field of lighting, which includes signaling, and that of the organs, in particular optical organs, which participate therein. It finds a particularly advantageous application in the field of motor vehicles. In particular, it relates to a lighting module for a motor vehicle.

STATE OF THE ART

[0002] In the automotive sector, modules are known which are capable of emitting light beams, also called lighting and/or signaling functions.

[0003] These modules must make it possible to emit light specifically in certain areas so as to exclude areas which must remain dark.

[0004] One of the constraints that manufacturers are also faced with is the reduction of the size of the module in order to achieve the most compact module possible, thus making it possible to obtain the maximum amount of free space at the front of the vehicle in the longitudinal direction of the vehicle (defined by the axis joining the front to the rear of the vehicle) to position other elements useful for driving and user comfort.

[0005] In order to best achieve these different objectives, a technical solution has been proposed in document FR 3056691 A1. This technical solution is based on the development of a light unit (or several light units aligned along a horizontal axis) in which the light sources of each light unit emit light rays in the vertical direction before they intercept the primary lens of the light unit.

[0006] However, this type of solution has drawbacks, notably the fact that it is limited in the extent of height lighting that it allows.

[0007] An object of the present invention is therefore to propose a module making it possible to overcome all or part of the disadvantages cited.

[0008] Other objects, features and advantages of the present invention will become apparent from a consideration of the following description and accompanying drawings. It is understood that other advantages may be incorporated.

SUMMARY

[0009] To achieve this objective, according to one embodiment, a light unit comprising:

- a support carrying a row of light sources, the row of light sources emitting light rays, the light sources of the row of light sources being aligned in a horizontal alignment direction and,

- an optical unit comprising a primary lens and a projection lens, wherein the primary lens comprises an input face, an output face and a reflection surface, the primary lens and the row of light sources being configured so that after being emitted, light rays pass through the input face, then so that the light rays are reflected by the reflection surface towards the output face, and wherein the projection lens is positioned after the primary lens in the direction of propagation of the light rays so that light rays pass through the projection lens after passing through the output face and are projected in the form of a beam having a mean projection direction, characterized in that the input face, the output face and the reflection surface are positioned substantially vertically, and in that the mean projection direction forms with the horizontal alignment direction an angle of less than 30°.

[0010] Thus, due to the configuration of the primary lens and the configuration of the row of light sources, the light rays emitted by the row of light sources are oriented (to head towards the primary lens) on average in a direction which may be orthogonal to the direction in which the light rays are oriented on average after passing through the projection lens. Also, the direction in which the light rays are emitted on average to head towards the primary lens is parallel or substantially oblique to a horizontal plane. Consequently, the configuration of the light unit makes it possible to limit the space occupied by the light unit in the longitudinal direction of the vehicle (the row of light sources not emitting light rays in the longitudinal direction) while making it possible to obtain extended lighting in height, in particular because it is possible to position several light units in the vertical direction. Furthermore, due to the configuration of the primary lens, and more precisely due to its prismatic shape, the light unit makes it possible to avoid the presence of stray light, particularly on either side of the area to be illuminated.

[0011] Another aspect relates to a light module comprising several light units, the light units sharing the same support, the optical units being vertically superimposed.

[0012] Due to the configuration of the light units, it is possible to position several light units sharing the same support by superimposing them in the vertical direction, in order to obtain the most extensive lighting as high as possible while having minimal space requirement in the longitudinal direction of the vehicle.

[0013] Another aspect relates to a vehicle comprising a light unit or comprising a light module.

BRIEF DESCRIPTION OF THE FIGURES

[0014] The aims, objects, as well as the characteristics and advantages of the invention will emerge more clearly from the detailed description of an embodiment thereof which is illustrated by the following accompanying drawings in which:

[0015] [Fig.1] Figure 1 represents a sectional view along a horizontal plane of the light unit in which the support is positioned in a direction substantially parallel to the direction in which the light rays are directed after passing through the projection lens.

[0016] [Fig.2] Figure 2 shows a sectional view along a horizontal plane of the light unit in which the support is positioned in a direction oblique to the direction in which the light rays are directed after passing through the projection lens.

[0017] [Fig.3] Figure 3 shows the light module in a perspective view where the support and the row of light sources are rotated around the first direction.

[0018] [Fig.4] Figure 4 shows a front view of the light module of Figure 3, so as to illustrate the rotation of the support around the first direction.

[0019] The drawings are given as examples and are not limiting of the invention. They constitute schematic representations of principle intended to facilitate the understanding of the invention and are not necessarily on the scale of practical applications. In particular, the paths of the light rays are not representative of reality.

DETAILED DESCRIPTION

[0020] Before beginning a detailed review of embodiments of the invention, optional features which may possibly be used in combination or alternatively are set out below:

[0021] According to one example, the angle between the entry face 2a and the reflection surface 2c is between 45° and 70°. [0022] Thus, thanks to this configuration, a maximum of light rays undergo total reflection upon their interaction with the reflection surface 2c, this considering a low inclination of the support 5 relative to the entry face 2a in comparison with the case where the support 5 would be strictly parallel to the entry face 2a.

[0023] According to one example, the row 1 of light sources is carried by a flat face of the support 5, the maximum distance separating the input face 2a and the flat face of the support 5 being less than 2 mm, preferably 0.7 mm, or even 0.5 mm.

[0024] This distance is chosen so as to be minimal. This distance is dependent on the thermal resistance of the material of the primary lens 2 which is selected so as to minimize as much as possible the distance between the light sources and the primary lens 2, in order to collect the maximum amount of light and therefore maximize efficiency.

[0025] According to one example, the minimum distance between the exit face 2b and the entrance diopter of the projection lens 3 is greater than 1 mm.

[0026] Thus, thanks to this configuration, certain light rays whose orientation would induce lighting in an undesired location, do not participate in the final lighting.

[0027] According to one example, the entry face 2a is convex.

[0028] Thus, the input face 2a is configured so as to direct the light rays 1a onto an area of the reflection surface 2c, thus making it possible to obtain illumination at the output of the primary lens 2 at the desired location.

[0029] According to one example, the exit face 2b is concave.

[0030] Thus, the exit face 2b is configured so as to direct the light rays 1a towards the projection lens 3, in order to obtain illumination of the road of the desired extent.

[0031] According to one example, the reflection surface 2c is concave.

[0032] Thus, the reflection surface 2c is configured so as to direct the light rays 1a onto an area of the exit face 2b, in order to be able to achieve an orientation of the light rays exiting the primary lens 2 having the desired configuration.

[0033] According to one example, the light unit comprises at least one secondary row 4 of light sources, the at least one secondary row 4 of light sources being positioned on the support 5 so as to emit light rays towards the entry face 2a, the light sources of the at least one secondary row 4 of light sources being aligned in a direction substantially parallel to the horizontal alignment direction D1.

[0034] Thus, positioning several rows of light sources on the support 5 allows to obtain with the same luminous unit an extended lighting in height or width.

[0035] According to one example, the light unit is configured to form or to participate in forming a main beam supplementary light.

[0036] It is specified that in the context of the present invention, the terms relating to verticality, horizontality or transversality (or lateral direction), or their equivalents, are understood in relation to the position in which the lighting system is intended to be mounted in a vehicle. The terms “vertical” and “horizontal” are used in the present description to designate directions, following an orientation perpendicular to the plane of the horizon for the term “vertical” (which corresponds to the height of the systems), and following an orientation parallel to the plane of the horizon for the term “horizontal”. They are to be considered in the operating conditions of the device in a vehicle. The use of these words does not mean that slight variations around the vertical and horizontal directions are excluded from the invention. For example, an inclination relative to these directions of the order of plus or minus 15° is here considered as a minor variation around the two preferred directions. Furthermore, the adjectives "inferior" and "superior" (and their equivalents "below" and "above") are to be taken in relation to the vertical direction; in the same context, a superior element will be located above (but not necessarily in contact with, or directly to the right of) a inferior element, following the vertical direction.

[0037] By “substantially”, in the context of “substantially parallel” or “substantially vertical”, is meant that an inclination of plus or minus 15° relative to the direction considered (i.e. the direction relative to which parallelism or verticality is considered) is to be taken into consideration.

[0038] In the context of the present invention, the concept of "input face, output face or reflection surface positioned substantially vertically" is to be taken into consideration by referring to the positioning of the mount (or even its edge) of the surface or face in question. Indeed, although the surface or face in question may be curved, the mount is itself positioned, in whole or in majority, according to a plane which may be vertical. Also, the concept of "verticality" of a surface or face which may be curved is to be considered by taking into account the verticality of the plane of symmetry of the face or surface including in whole or in majority the mount of the face or surface. [0039] According to one embodiment, the light unit according to the invention comprises a support 5, a row 1 of light sources and an optical unit 6. The row 1 of light sources emits light rays 1a towards the entry face 2a. The row 1 of light sources is positioned on the support 5 so that the light rays 1a are directed towards the entry face 2a. The light sources of the row 1 of light sources are arranged in a straight line in a horizontal alignment direction D1.

[0040] The optical unit 6 comprises a primary lens 2 and a projection lens 3. The primary lens 2 comprises an input face 2a, an output face 2b and a reflection surface 2c. The primary lens 2 and the row 1 of light sources are configured so that after being emitted, light rays 1a are transmitted by the input face 2a, to then be deflected by the reflection surface 2c towards the output face 2b. More precisely, the light rays 1a undergo reflection on the reflection surface 2c.

[0041] The projection lens 3 is positioned after the primary lens 2 so that light rays 1a are transmitted first by the primary lens 2 and second by the projection lens 3. The projection lens 3 makes it possible to collimate the light beam formed by the light rays having passed through the exit face of the primary lens 2 so that after passing through the projection lens 3 these light rays form a beam which can be defined by a mean projection direction. The entry face 2a, the exit face 2b and the reflection surface 2c are positioned substantially along a vertical plane. The mean projection direction forms an angle of less than 30° with the horizontal alignment direction D1.

[0042] Thus, in this configuration, if we consider the optical axis of the projection lens 3, the light rays 1a can be emitted on average in a direction perpendicular to the optical axis of the projection lens 3. Consequently, it is necessary to position a reflection surface 2c on the path of the light rays 1a in order to obtain at the output of the projection lens 3 an orientation on average of the light rays 1a in a direction which can be substantially parallel to the optical axis of the projection lens 3.

[0043] In this configuration, since the input face is positioned substantially vertically, the input face 2a can be rotated about the horizontal alignment direction D1 so that it forms with the plane P1 (including the horizontal alignment direction D1 and being vertical) an angle of between -15° and 15°.

[0044] Thus, this configuration makes it possible to position several units optics one above the other in the case where the light units share the same support 5 and where they are offset in a direction perpendicular to the plane P1. In this configuration, as illustrated in Figure 3, the support 5 can be thus inclined so that, when the light module is oriented so that the projection lenses 3 are in front of lenses 2, the successively superimposed light units are positioned going from right to left.

[0045] According to a preferred example, the entry face 2a is positioned strictly vertically.

[0046] Advantageously, the angle between the entry face 2a and the reflection surface 2c is between 45° and 70°. Preferably, the angle between the entry face 2a and the reflection surface 2c can be measured in a plane orthogonal to the entry face 2a.

[0047] Preferably, the angle between the entry face 2a and the reflection surface 2c is 55°.

[0048] Preferably, the row 1 of light sources is carried by a flat face of the support 5. The maximum distance separating the input face 2a and the flat face of the support 5 is less than 2 mm, preferably 0.7 mm, or even 0.5 mm.

[0049] The flat face of the support 5 can be positioned substantially parallel to the entry face 2a. Preferably, the flat face of the support 5 can be positioned strictly parallel to the entry face 2a.

[0050] Preferably, the entry face 2a is curved on its face receiving the light rays 1a while being rounded on the outside to form a curved zone.

[0051] Advantageously, the exit face 2b is curved on its face receiving the light rays 1a, being rounded on the inside to form a hollow zone.

[0052] According to an advantageous example, the reflection surface 2c is curved on its face receiving the light rays 1a while being rounded on the inside to form a hollow zone. The reflection surface 2c may have a very high radius of curvature, thus being able to have a value greater than or equal to 100 mm. The radius of curvature of the reflection surface 2c may be - 4000 mm.

[0053] According to one example, the reflection surface is planar.

[0054] The projection lens 3 may be a converging meniscus.

[0055] According to one example, the projection lens 3 may be an aspherical lens.

[0056] The projection lens 3 may have a size of 35 by 30 mm. The primary lens 2 may have a size of 35 by 30 mm. The depth of the primary lens 2 can be 35 mm. The thickness of the diopters of the projection lens 3 can be between 3.5 mm and 6.5 mm.

[0057] Preferably, the primary lens and the projection lens are made of PMMA (polymethyl methacrylate), silicone, glass or PC (polycarbonate).

[0058] The reflection surface 2c is a total internal reflection (TIR) surface. Thus, the optical index of the reflection surface 2c is defined in such a way that a significant portion of the light rays incident on this surface 2c undergo total reflection.

[0059] Preferably, the minimum distance between the exit face 2b and the entrance diopter of the projection lens 3 is greater than 1 mm.

[0060] According to a preferred example, the light unit comprises at least one secondary row 4 of light sources. The at least one secondary row 4 of light sources can be positioned on the support 5 so that the light rays coming from this row are directed towards the entry face 2a. The light sources of the at least one secondary row 4 of light sources can be arranged in a straight line in a direction substantially parallel to the horizontal alignment direction D1. The at least one secondary row 4 of light sources can be positioned below or above the row 1 of light sources. The at least one secondary row 4 of light sources can be positioned in the extension of the row 1 of light sources.

[0061] Row 1 of light sources may comprise 12 light sources. Each row 4 of light sources may comprise 12 light sources.

[0062] The light sources of the row 1 of light sources and of the at least one secondary row 4 of light sources can be selectively switched on, thus creating a pixelated light source.

[0063] This configuration allows for “ADB” lighting (for Adaptive Driving Beam). In fact, selective activation of the light sources allows for varied light beam configurations to be obtained, allowing adaptation to various situations. Thus, the areas that need to be lit will be lit, and those whose brightness must be reduced to avoid dazzling other users and to comply with regulatory constraints will also be lit.

[0064] This discretization of light is also referred to as a segmented beam. Thus, a segmented beam is called a beam whose projection forms an image composed of beam segments (resulting from the ignition of a group of light sources), each segment being able to be lit independently.

[0065] Thus, not all emissive elements are necessarily simultaneously active, i.e. emitting light. This function makes it possible to modulate the shape of the rendered beam. In the case where a light source is not activated, its image, as projected by the optical module, will be zero. It then forms a dark zone in the resulting overall beam. This void is understood to include coupling phenomena at the source and the effects of stray light from the optics.

[0066] More specifically, ADB lighting makes it possible to improve night driving conditions by allowing the driver to illuminate the road on which he is traveling as much as possible without dazzling other users. To this end, the resulting beam is formed by a plurality of juxtaposed segments that can be selectively and individually activated. Thus, if a user is detected by the light unit, only the segment likely to dazzle this user is switched off (the other segments remaining lit), which makes it possible to optimize the lighting of the road.

[0067] The light unit according to the invention may comprise a unit for controlling the activation of each of the sources, configured to produce at least one dark zone forming a tunnel in a projected beam by deactivating a group of adjacent sources, the control unit being configured to determine the number of sources in the group corresponding to the dark zone as a function of the width dimension of the sources.

[0068] The control unit may comprise a computer program product, preferably stored in a non-transitory memory, in which the computer program product comprises instructions which, when executed by a processor, make it possible to determine the sources to be activated, in particular to obtain at least one dark zone (in which the sources are not activated) of a determined surface taking into account the variable surface of the images of the elements.

[0069] The light sources of the entire light unit may be light-emitting diodes, also commonly called LEDs.

[0070] Advantageously, the LEDs of the entire light unit have an emissive surface of 0.5 mm ² or 1 mm ² . The LEDs having an emissive surface of 0.5 mm ² may have a height and width of 0.76 mm. The LEDs having an emissive surface of 1 mm ² may have a height and width of 1 mm. The size of the LEDs is directly related to the desired beam volume.

[0071] The distance between the centers of two consecutive LEDs of row 1 of light sources may be 1.025 mm. The spacing between two consecutive LEDs may be 25 pm.

[0072] According to an advantageous example, the light unit is configured to form or to participate in forming a main beam supplementary light.

[0073] The light unit may include a secondary light unit configured to produce, in dipped beam mode, a portion of a cut-off low beam. The light unit may include another secondary light unit configured to produce a near-field beam of a low beam. The resulting angled portion is called the “kink” of the “dipped beam”.

[0074] Beams of the dipped beam type typically have a first lateral zone (normally on the edge of the roadway) projecting at a height slightly higher than in a second lateral zone (normally on the middle of the roadway), these two zones following each other laterally with the presence of a bend or elbow between them.

[0075] More precisely, the near field beam of a dipped beam corresponds to a beam which can be considered as the base of a dipped beam.

[0076] A main beam supplement has the function of illuminating the scene in front of the vehicle over a wide area, but also over a significant distance, typically around two hundred meters. This light beam, due to its lighting function, is located mainly above the horizon line. It may have a slightly ascending optical axis of illumination, for example. In particular, it may be used to generate a lighting function of the “complementary” type which forms a portion of a main beam complementary to that produced by a near-field beam of a dipped beam, the main beam supplement seeking entirely or at least mainly to illuminate above the horizon line, whereas the near-field beam of a dipped beam (which may have the specific characteristics of a dipped beam) seeks to illuminate entirely or at least mainly below the horizon line. The main beam supplement may therefore be a main part of the overall “main beam” and be associated with another beam participating in the dipped beam. Thus, the additional high beam can form, in combination with a near-field beam of the dipped beam, an overall high beam beam. A near-field beam of a dipped beam is typically a relatively spread projection laterally at the front of the vehicle, mostly or totally below the horizon line, generally seeking a good distribution of illumination over the entire illuminated area. [0077] The light unit can also be used to form other lighting functions via or outside those described above, in relation to the adaptive beams. It is thus possible to produce a lighting matrix to selectively illuminate parts of the space in front of the vehicle.

[0078] According to another embodiment, the invention describes a light module comprising several light units. In this light module, the light units share the same support 5. The optical units 6 are superimposed in a vertical direction. The optical units may or may not be offset in a direction perpendicular to the plane P1.

[0079] In the case where the optical units are offset in a direction perpendicular to the plane P1, the light units making up the light module are offset in the vertical direction and also in the horizontal direction.

[0080] Thus, the fact that each light unit is configured to form or to participate in forming a segmented road supplementary light implies that the light module makes it possible to form or participate in forming a segmented road supplementary light composed of all the segmented road supplementary lights of each light unit making up the light module. All the segmented road supplementary lights of each light unit making up the light module are partly superimposed so that the resulting light intensity is greater and also so that the illumination is more extensive (in particular in height) than if the light module were composed of a single light unit. Since row 1 (and row 4) of light sources of each light unit making up the light module can be activated individually (relative to the other rows 1 (and other rows 4) of light sources of the light module) and the light sources of each row 1 (and each row 4) of light sources can be activated individually, the light module makes it possible to produce lighting composed of a plurality of juxtaposed light segments which can be selectively activated.

[0081] The light module may comprise 2, 3, 4 or 5 or more light units.

[0082] One or more light modules according to the invention may be arranged in a housing closed by a glass so as to obtain one or more lighting and/or signaling beams at the output of the projector. A projector may also be complex and combine several modules which may, in addition, possibly share components. [0083] According to another embodiment, the invention describes a vehicle comprising a light unit or comprising a light module.

[0084] The invention is not limited to the embodiments previously described and extends to all embodiments covered by the invention.

[0085] List of references:

1. row of light sources

1a. light rays

2. primary lens

2a. entrance face

2b. exit face

2c. reflection surface

3. projection lens

4. at least one secondary row of light sources

5. support

6. optical unit

D1. horizontal alignment direction

P1. plan

Claims

Claims [Claim 1] A light unit comprising: - a support (5) carrying a row (1) of light sources, the row (1) of light sources emitting light rays (1a), the light sources of the row (1) of light sources being aligned in a horizontal alignment direction (D1) and, - an optical unit (6) comprising a primary lens (2) and a projection lens (3), wherein the primary lens (2) comprises an input face (2a), an output face (2b) and a reflection surface (2c), the primary lens (2) and the row (1) of light sources being configured so that after being emitted, light rays (1a) pass through the input face (2a), then so that the light rays (1a) are reflected by the reflection surface (2c) towards the output face (2b), and wherein the projection lens (3) is positioned after the primary lens (2) in the direction of propagation of the light rays (1a) so that light rays (1a) pass through the projection lens (3) after passing through the output face (2b) and are projected in the form of a beam having a mean projection direction, characterized in that the input face (2a), the output face (2b) and the reflection surface (2c) are positioned substantially vertically, and in that the average projection direction forms an angle of less than 30° with the horizontal alignment direction (D1). [Claim 2] Light unit according to the preceding claim in which the angle between the entry face (2a) and the reflection surface (2c) is between 45° and 70°. [Claim 3] Light unit according to any one of the preceding claims in which the row (1) of light sources is carried by a flat face of the support (5), the maximum distance separating the input face (2a) and the flat face of the support (5) being less than 2 mm, preferably 0.7 mm, or even 0.5 mm. [Claim 4] A light unit according to any preceding claim wherein the input face (2a) is convex. [Claim 5] A light unit according to any preceding claim wherein the output face (2b) is concave. [Claim 6] A light unit according to any preceding claim wherein the reflecting surface (2c) is concave. [Claim 7] A light unit according to any preceding claim comprising at least one secondary row (4) of light sources, the at least one secondary row (4) of light sources being positioned on the support (5) so as to emit light rays towards the entry face (2a), the light sources of the at least one secondary row (4) of light sources being aligned in a direction substantially parallel to the horizontal alignment direction (D1). [Claim 8] A light unit according to any preceding claim wherein the minimum distance between the exit face (2b) and the entrance diopter of the projection lens (3) is greater than 1 mm. [Claim 9] A light unit according to any one of the preceding claims configured to form or to participate in forming a main beam supplementary light. [Claim 10] Light module comprising several light units according to any one of the preceding claims, the light units sharing the same support (5), the optical units (6) being vertically superimposed. [Claim 11] Vehicle comprising a light module according to the preceding claim. [Claim 12] A vehicle comprising a light unit according to any one of claims 1 to 9.