Illumination device for automotive headlamp for light distribution generation

Abstract

To provide an illumination device with an optic body allowing modification of light output characteristics.SOLUTION: The invention provides an illumination device for a motor vehicle headlamp. The illumination device (1) includes a light source (2) for emitting a light beam with a first vertical extent (v1), an optic body (3) for guiding the light beam, and an optical system (5) for projecting the light beam in front of the illumination device (1). The optic body (3) includes a first pair of optically operative surfaces (6) for guiding the light beam input to the optic body (3). The first pair of optically operative surfaces (6) comprises first and second light deflection surfaces (6a, 6b) configured to deflect the light beam while traveling through the optic body (3). The first and second light deflection surfaces (6a, 6b) are configured such that multiple light rays forming the light beam are essentially parallel to each other and to a main direction (X) after being output form the optic body (3). The output parallel light beam has a second vertical extent (v2) in a main vertical cross section (v), where the second vertical extent (v2) is greater than the first vertical extent (v1).SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] This application claims the benefit of priority under the Paris Convention for European Patent Application No. 22202973.8, filed on October 21, 2022, the entire contents of which are incorporated herein by reference and are set forth herein.

[0002] The present invention is an illumination device for a motor vehicle headlamp for generating a light distribution, wherein the illumination device · a light source configured to emit at least one light beam in a main direction of the illumination device, · an optical body arranged downstream of the light source along the main direction, provided that the optical body · a light incident portion for coupling (inciding) a light beam from the light source into the optical body, provided that the light incident portion is assigned to the light source and couples a light beam from the assigned light source into the optical body such that a plurality of light rays forming the light beam are substantially parallel to each other and substantially parallel to the main direction after being coupled into the optical body. The parallel light beam has a first vertical (longitudinal) length (width) in a main vertical (longitudinal) cross-section when viewed in a state where the illumination device is properly mounted on a motor vehicle during coupling into the optical body, provided that the main vertical cross-section is parallel to the main direction, · a light emitting portion for separating (emitting) the light beam coupled into the optical body through the light incident portion from the inside to the outside in the main direction, · a shell surface defining the optical body, provided that the shell surface is configured to deflect the light beam coupled into the optical body, and the shell surface extends between the light incident portion and the light emitting portion including · An optical system including at least one optical element disposed downstream of the optical body along the main direction for receiving (receiving light) the light beam emitted from the light emitting portion of the optical body, provided that the optical system is configured to project the light beam forward of the lighting device, and the optical system combined with the light source and the optical body is configured to generate the light distribution. Relates to a lighting device including.

[0003] Furthermore, the present invention relates to an automotive headlamp including a lighting device.

Background Art

[0004] In the prior art, lighting devices for use in automotive headlamps for generating a light distribution are well known. Typically, a light source generates and emits light, which is guided through an optical body, such as a light guide, to an optical system. The optical system is configured to generate a specific optical function or light distribution (e.g., a light distribution for a low beam, a light distribution for a high beam, etc.) by the light received from the light source through the optical body.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Summary of the Invention

Problems to be Solved by the Invention

[0006] In the prior art, an optical body is usually a planar light guide configured to guide light to a specific part, for example, the light incident surface of an optical system. Such a planar light guide (or light guiding optical body) can also compensate for an off-axis arrangement of a light source and an optical system, but such an arrangement is due to the design of a lighting device or a headlamp using the lighting device. Due to its characteristics (properties), a planar light guide cannot affect the size (diameter) or divergence (angle) (expansion or (end) spread (angle): divergency) of a light beam or light ray guided through the light guide. Therefore, possible light emission from the planar light guide is rather limited. To correct the size and divergence of a light beam, usually, an additional optical element such as a lens is used.

[0007] An object of the present invention is to provide a lighting device having an optical body whose light emission characteristics can be corrected (changed).

Means for Solving the Problems

[0008] This object is achieved by a lighting device and an automotive headlamp according to the present invention. According to a first aspect of the present invention, a lighting device for an automotive headlamp for generating a light distribution is provided. The lighting device · a light source configured to emit at least one light beam in a main direction of the lighting device, · an optical body arranged downstream of the light source along the main direction, provided that the optical body · A light incident portion for coupling (injecting) a light beam from the light source into the optical body, provided that the light incident portion is assigned to the light source and couples a light beam from the assigned light source into the optical body such that a plurality of light rays forming the light beam are substantially parallel to each other and substantially parallel to the main direction after being coupled into the optical body. The parallel light beam has a first vertical length (width) in a main vertical cross-section when viewed in a state where the lighting device is properly mounted on an automobile during coupling into the optical body, provided that the main vertical cross-section is parallel to the main direction. It is a plane perpendicular to the release horizontal plane, and the "vertical length" means the length of the light beam in the height direction. , · A light exit portion for separating (emitting) the light beam coupled into the optical body through the light incident portion from the inside to the outside of the optical body in the main direction. · A shell surface that defines (outlines) the optical body, provided that the shell surface is configured to deflect the light beam coupled into the optical body, and the shell surface extends between the light incident portion and the light exit portion. including · An optical system including at least one optical element arranged downstream of the optical body along the main direction for receiving (receiving light from) the light beam emitted from the light exit portion of the optical body. The optical system is configured to project a light beam forward of the lighting device, and the optical system combined with the light source and the optical body is configured to generate the light distribution. including The optical body includes a first pair of optical working surfaces (plural) for guiding the light beam coupled into the optical body through the light incident portion from the light incident portion to the light exit portion along a first light beam path. The first pair of optical working surfaces is composed of a first light deflection surface and a second light deflection surface. The first light deflection surface and the second light deflection surface are provided (formed) on the shell surface. The optical body includes a first side and a second side that face each other. The first light deflection surface is provided (formed) on the first side of the optical body, and the second light deflection surface is provided (formed) on the second side of the optical body. In the main vertical cross-section, the first light deflection surface follows (is along) a first parabola, the second light deflection surface follows (is along) a second parabola, and the first light deflection surface and the second light deflection surface are provided (formed) on the shell surface such that the first parabola and the second parabola have a common focus. The light beam traveling along (following) the first light beam path is incident on the first light deflection surface, deflected toward the second light deflection surface, the deflected light beam is incident on the second light deflection surface, and is deflected toward the light emission part for separation from the inside to the outside of the optical body. The light emission part includes a first light emission surface, and the first pair of optical action surfaces and the light emission part are arranged such that the light beam deflected by the second light deflection surface is incident on the first light emission surface. The first light deflection surface, the second light deflection surface, and the first light emission surface are configured such that a plurality of light rays forming a light beam are substantially parallel to each other and substantially parallel to the main direction after being separated (emitted) from the inside to the outside of the optical body. The separated parallel light beam has a second vertical length in the main vertical cross-section, and the second vertical length is greater than the first vertical length. 、 The light source is configured to emit a second light beam, and the optical body includes a second pair of optical action surfaces (plural) for guiding the second light beam coupled into the optical body through the light incident portion along a second light beam path from the light incident portion to the light exit portion. When the second light beam is coupled into the optical body, it has a third vertical length in the main vertical cross section. The second pair of optical action surfaces is composed of a third light deflection surface and a fourth light deflection surface. The third light deflection surface and the fourth light deflection surface are provided (formed) on the shell surface. The third light deflection surface is provided (formed) on the first surface of the optical body 3, and the fourth light deflection surface is provided (formed) on the second surface of the optical body. In the main vertical cross section, the third light deflection surface follows a third parabola, and the fourth light deflection surface follows a fourth parabola. The third light deflection surface and the fourth light deflection surface are provided (formed) on the shell surface such that the third parabola and the fourth parabola have a common second focus. The second light beam traveling along the second light beam path is incident on the third light deflection surface and is deflected toward the fourth light deflection surface. The deflected second light beam is incident on the fourth light deflection surface and is deflected toward the light exit portion for separation from the inside to the outside of the optical body. The light exit portion includes a second light exit surface. The second pair of optical action surfaces and the light exit portion are arranged such that the light beam deflected by the fourth light deflection surface is incident on the second light exit surface. The third light deflection surface and the fourth light deflection surface are configured such that a plurality of light rays of the second light beam are substantially parallel to each other and substantially parallel to the main direction after being separated (emitted) from the inside to the outside of the optical body. The separated substantially parallel light beams have a fourth vertical length in the main vertical cross section, and the fourth vertical length is smaller than the third vertical length. (Form 1). According to a second aspect of the present invention, an automotive headlamp including at least one lighting device of the present invention is provided (Form 11 ).

Embodiments for Carrying Out the Invention

[0009] (Form 1) Refer to the first aspect of the present invention described above. 。 ( Form 2 ) Form 1 In the lighting device according to the above, The first light deflection surface, the second light deflection surface, the third light deflection surface, and the fourth light deflection surface are the common first focal point and the common second focal point including and perpendicular to the main vertical cross section Virtual surface is before are arranged so as to intersect the optical body, and the optical body is configured such that the first light deflection surface is higher than the third light deflection surface relative to the intersection line in a direction relatively perpendicular to the intersection line. The virtual surface is the line where the virtual surface intersects the first surface of the optical body. It is preferably configured. (Form 3 ) Form 1 In the lighting device according to The generated light distribution includes a first partial light distribution and a second partial light distribution. At least one light beam separated from the first light emitting surface to the outside forms the first partial light distribution, and the second light beam separated from the second light emitting surface to the outside preferably forms the second partial light distribution. (Form 4 ) Form 3 In the lighting device according to The generated light distribution is a light distribution for a low beam, and the vertical (direction) length (spread) of the light distribution for the low beam preferably extends downward along the VV line from at least 0° to at least -10° on the VV line. (Form 5 ) Form 4 In the lighting device according to The center of the first partial light distribution is preferably closer to the 0° line of the VV line than the center of the second partial light distribution. (Form 6 ) Form 1 In the lighting device according to The first light deflection surface and the third light deflection surface are preferably arranged on the same surface (side) of the shell surface of the optical body. (Form 7 ) Form 1 In the lighting device according to The second light deflection surface and the fourth light deflection surface are preferably arranged on the same surface (side) of the shell surface of the optical body. (Form 8 ) Form 1 In the lighting device according to The first light deflection surface and the second light deflection surface have a concave curvature, and the 3 fourth light deflection surface preferably has a convex curvature. (Aspect 9 ) In the lighting device according to Aspect 1, the plurality of light rays forming the at least one light beam have a first divergence along the main direction in the main vertical cross-section, and the plurality of light rays forming the at least one light beam have a second divergence in the main vertical cross-section after being separated from the inside of the optical body to the outside, and the second divergence is smaller than the first divergence However, "divergence" corresponds to the angle between adjacent light rays along the light propagation direction. is preferred. (Aspect 10 ) In the lighting device according to Aspect 1 , the plurality of light rays forming the second light beam have a third divergence along the main direction in the main vertical cross-section, and the plurality of light rays forming the second light beam have a fourth divergence in the main vertical cross-section after being separated from the inside of the optical body to the outside, and the fourth divergence is preferably larger than the third divergence. (Aspect 11 ) Refer to the second perspective of the present invention above.

[0010] In the lighting device according to the present invention, the light beam is expanded (or widened) while traveling through the optical body, so that the divergence of the light beam can be reduced, thereby having the advantage of reducing (suppressing) undesired optical effects such as chromatic aberration. This provides a greater variety in the possible optical functions that can be created by the lighting device. In particular, since the diameter of the light beam increases while traveling through the optical body, the optical body acts (functions) as a so-called beam expander. Considering the optical body three-dimensionally, the first pair of optical action surfaces can also be described as (3D) paraboloidal or (partially) truncated paraboloidal surfaces. Divergence can be understood to substantially correspond to the angle between adjacent light rays along (seen in) the light propagation direction. Divergence can also be described as beam divergence, which can be described as the angle (notation) of the increase in beam diameter or beam radius according to the distance from the element (e.g., light source) where the beam emerges (comes out). Beam divergence usually relates to a beam having a circular cross-section. The beam may have, for example, an elliptical cross-section, in which case the direction (or orientation) of the beam divergence needs to be specified, for example, with respect to the major or minor axis of the elliptical cross-section. Preferably, the optical system, and in particular at least one optical element, is configured to invert the light pattern received (light-received) from the optical body along (along the vertical axis or vertical plane). Generally, the larger the beam diameter, the smaller the divergence (angle).

[0011] Advantageously, the light source is configured to emit a second light beam, and the optical body includes a second pair of optical action surfaces for guiding the second light beam coupled (incident) into the optical body through the light incident portion from the light incident portion to the light emitting portion along the second light beam path. The second light beam has a third vertical (longitudinal) length (width) in the main vertical cross-section when coupled (incident) into the optical body. The second pair of optical action surfaces is composed of a third light deflection surface and a fourth light deflection surface. The third light deflection surface and the fourth light deflection surface are provided (formed) on the shell surface. The third light deflection surface is provided (formed) on the first surface of the optical body, and the fourth light deflection surface is provided (formed) on the second surface of the optical body. In the main vertical cross-section, the third light deflection surface follows a third parabola, and the fourth light deflection surface follows a fourth parabola. The third light deflection surface and the fourth light deflection surface are provided (formed) on the shell surface such that the third parabola and the fourth parabola have a common second focus. The second light beam traveling along the second light beam path is incident on the third light deflection surface and is deflected towards the fourth light deflection surface. The deflected second light beam is incident on the fourth light deflection surface and is deflected towards the light exit portion for separation (exit) from the inside to the outside of the optical body. The light exit portion includes a second light exit surface. The second pair of optical action surfaces and the light exit portion are arranged such that the light beam deflected by the fourth light deflection surface is incident on the second light exit surface. The third light deflection surface and the fourth light deflection surface are configured such that a plurality of light rays of the second light beam are substantially parallel to each other and substantially parallel to the main direction after being separated (exited) from the inside to the outside of the optical body. The separated substantially parallel light beams have a fourth vertical length in the main vertical cross-section, and the fourth vertical length is smaller than the third vertical length.

[0012] This has the advantage that the first pair of optical action surfaces can act (function) as a beam expander and the second pair of optical action surfaces can act (function) as a beam compressor. The beam expander enlarges the cross-section of the first part of the light beam (i.e., at least one light beam), and the beam compressor reduces the cross-section of the second part of the light beam (i.e., the second light beam). Advantageously, the first part of the total light beam emitted from the light source can be compressed (reduced), while the second part of the total light beam can be enlarged, and the enlargement and the compression can be achieved by the first part and the second part of the optical action surfaces respectively.

[0013] Advantageously, the first light deflection surface, the second light deflection surface, the third light deflection surface, and the fourth light deflection surface are arranged such that a virtual surface intersecting a common first focus and a common second focus intersects the optical body at the intersection line, and the optical body is configured such that the first light deflection surface is higher (located) in a direction relatively perpendicular to the intersection line than the third light deflection surface.

[0014] Advantageously, the generated light distribution includes a first partial light distribution and a second partial light distribution. At least one light beam separated (emitted) from the first light emission surface to the outside forms the first partial light distribution, and a second light beam separated (emitted) from the second light emission surface to the outside forms the second partial light distribution. In other words, the expanded light beam is used to form the first partial light distribution, and the compressed light beam is used to form the second partial light distribution.

[0015] Advantageously, the generated light distribution is a light distribution for a low beam, and the vertical (direction) length (spread) of the light distribution for the low beam extends downward from at least 0° along the VV line to at least -10° at the VV line.

[0016] Advantageously, the center of the first partial light distribution is closer to the 0° line of the VV line than the center of the second partial light distribution. Advantageously, the first pair of optical action surfaces and the second pair of optical action surfaces can be arranged such that the center of the second partial light distribution is closer to the 0° line of the VV line than the center of the first partial light distribution. In other words, the light distribution located higher in the vertical direction can be generated by a compressed (reduced) or expanded light beam depending on the arrangement of the first pair of optical action surfaces and the second pair of optical action surfaces.

[0017] Advantageously, the first light deflection surface and the third light deflection surface are provided (formed) on the same side (surface) of the shell surface of the optical body.

[0018] Advantageously, the second light deflection surface and the fourth light deflection surface are provided (formed) on the same side (surface) of the shell surface of the optical body.

[0019] Advantageously, the first light deflection surface and the second light deflection surface have a concave curvature, and the second light deflection surface and the fourth light deflection surface have a convex curvature.

[0020] Advantageously, the plurality of light rays forming at least one light beam have a first divergence along the main direction in the main vertical section, and the plurality of light rays forming at least one light beam have a second divergence in the main vertical section after being separated (emitted) from the inside to the outside of the optical body, and the second divergence is smaller than the first divergence.

[0021] Advantageously, the plurality of light rays forming the second light beam have a third divergence along the main direction in the main vertical section, and the plurality of light rays forming the second light beam have a fourth divergence in the main vertical section after being separated (emitted) from the inside to the outside of the optical body, and the fourth divergence is larger than the third divergence. Advantageously, the fourth divergence (of the compressed second light beam) is also larger than the second divergence of at least one (or the first) light beam. The lower (or smaller) second divergence is the result of a wider (expanded) at least one light beam. As a result, at least one light beam will impinge on the projection lens at a smaller angle, so that chromatic aberration or other color effects are reduced.

[0022] The terms "up", "down", "vertical", "horizontal", "front", "forward", "rear" and "back" should be understood as being from (with reference to) an automotive headlamp or a lighting device properly mounted on an automobile.

[0023] Hereinafter, for further explanation of the present invention, exemplary and non-limiting embodiments as shown in the drawings will be described.

Brief Description of the Drawings

[0024]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Example

[0025] FIG. 1 is a schematic side view of an example of an optical body 3 of a first embodiment of a lighting device 1 for an automotive headlamp.

[0026] FIG. 2 shows an example of an optical body 3 of a second embodiment, which will be described in more detail below. The perspective view of the optical body of the second embodiment is shown in FIG. 3.

[0027] (As seen in FIG. 4) The lighting device 1 includes a light source 2 configured to emit at least one light beam in the main direction X of the lighting device 1. The optical body 3 is disposed downstream of the light source 2 along the main direction X.

[0028] FIG. 1 is a schematic diagram of an optical body 3 including a light incident portion 3a for coupling (incident) a light beam (indicated by a shaded arrow) from the light source 2 into the optical body 3. The light incident portion 3a includes a light collection element 4 (seen in FIG. 4). The light collection element 4 is assigned to the light source 2 and is configured to couple (incident) a light beam from the assigned light source 2 into the optical body 3 such that a plurality of light rays forming the light beam are substantially parallel to each other and substantially parallel to the main direction X after being coupled into the optical body 3. The parallel light beam has a first vertical (longitudinal) length v1' in the main vertical (longitudinal) section v when viewed in a state where the lighting device 1 is properly mounted on an automobile. The main vertical section v is parallel to the main direction X.

[0029] The optical body 3 includes a light emitting portion 3b for separating (emitting) a light beam coupled (incident) into the optical body 3 from the inside to the outside in the main direction X through the light incident portion 3a. The optical body 3 further includes a shell surface 3c that limits (defines) the optical body 3. The shell surface 3c is configured to deflect a light beam coupled (incident) into the optical body 3. The shell surface 3c extends between the light incident portion 3a and the light emitting portion 3b.

[0030] As shown in FIG. 4, the lighting device 1 includes an optical system 5 including at least one optical element 5a disposed downstream of the optical body 3 along the main direction X to receive a light beam emitted from the light emitting portion 3b of the optical body 3. The optical system 5 is configured to project the light beam forward of the lighting device 1. The optical system 5 combined with the light source 2 and the optical body 3 is configured to generate a light distribution. The generated light beam can be a light distribution for a low beam, and the vertical extension (range) of the light distribution for the low beam extends downward from at least 0° along the VV line (vertical line) to at least -10° on the VV line.

[0031] The optical body 3 includes a first pair of optical action surfaces 6 for guiding a light beam coupled (incident) into the optical body 3 through the light incident portion 3a from the light incident portion 3a to the light emitting portion 3b via the first light beam path LB1. The first pair of optical action surfaces 6 is composed of a first light deflection surface 6a and a second light deflection surface 6b, and the first light deflection surface 6a and the second light deflection surface 6b are provided (formed) on the shell surface 3c. The optical body 3 includes a first surface (side) and a second surface (side) facing each other, the first light deflection surface 6a is provided (formed) on the first surface (side) (of the optical body 3), and the second light deflection surface 6b is provided (formed) on the second surface (side) of the optical body 3.

[0032] In the main vertical cross-section v, the first light deflection surface 6a follows (is along) a first parabola, the second light deflection surface 6b follows (is along) a second parabola, and the first light deflection surface 6a and the second light deflection surface 6b are provided (formed) on the shell surface 3c such that the first parabola and the second parabola have a common first focal point fp1. The light beam traveling along (following) the first light beam path LB1 is incident on the first light deflection surface 6a and is deflected toward the second light deflection surface 6b. The deflected light beam is incident on the second light deflection surface 6b and is deflected toward the light emission part 3b for separation (emission) from the inside to the outside of the optical body 3.

[0033] The light emission part 3b includes a first light emission surface 7a, and the first pair of optical action surfaces 6 and the light emission part 3b are arranged such that the light beam deflected by the second light deflection surface 6b is incident on the first light emission surface 7a. The first and second light deflection surfaces 6a, 6b and the first light emission surface 7a are configured such that a plurality of light rays forming the light beam are substantially parallel to each other and substantially parallel to the main direction X after being separated (emitted) from the inside to the outside of the optical body 3. The separated parallel light beam has a second vertical (longitudinal) length v2' in the main vertical cross-section v. The second vertical length v2' is larger than the first vertical length v1'. This is indicated by the wider diagonal hatching arrows on the left side (in the plane of the paper) of the optical body 3. The optical body 3 acts as a beam expander in the embodiment shown in FIG. 1.

[0034] In the embodiment shown in FIG. 2, the light source 2 is configured to emit a second light beam (or a light beam including two parts), and the optical body 3 includes a second pair of optical action surfaces 8 for guiding the second light beam coupled (flowed) into the optical body 3 through the light incident part 3a from the light incident part 3a to the light emission part 3b along the second light beam path LB2. The second light beam has a third vertical (longitudinal) length v3 in the main vertical cross-section v when being coupled into the optical body 3. The second light beam is described by the black (filled) arrow.

[0035] The second pair of optical action surfaces 8 is composed of a third light deflection surface 8a and a fourth light deflection surface 8b. The third light deflection surface 8a and the fourth light deflection surface 8b are provided (formed) on the shell surface 3c. The third light deflection surface 8a is provided (formed) on the first side of the optical body 3, and the fourth light deflection surface 8b is provided (formed) on the second side of the optical body 3. In the main vertical cross-section v, the third light deflection surface 8a follows (is along) a third parabola, and the fourth light deflection surface 8b follows a fourth parabola. The third light deflection surface 8a and the fourth light deflection surface 8b are provided (formed) on the shell surface 3c such that the third parabola and the fourth parabola have a common second focal point fp2.

[0036] The second light beam traveling along (following) the second light beam path LB2 is incident on the third light deflection surface 8a, deflected toward the fourth light deflection surface 8b, and the deflected second light beam is incident on the fourth light deflection surface 6b and deflected toward the light emitting portion 3b for separation from the inside to the outside of the optical body 3.

[0037] The light emitting portion 3b includes a second light emitting surface 7b. The second pair of optical action surfaces 8 and the light emitting portion 3b are arranged such that the light beam deflected by the fourth light deflection surface 8b is incident on the second light emitting surface 7b. The third light deflection surface 8a and the fourth light deflection surface 8b are configured such that a plurality of light rays of the second light beam are substantially parallel to each other and substantially parallel to the main direction X after being separated (emitted) from the inside to the outside of the optical body 3. The separated substantially parallel light beams have a fourth vertical length v4 in the main vertical cross-section v. The fourth vertical length v4 is smaller than the third vertical length v3. The optical body 3 acts as a beam expander in the embodiment shown in FIG. 1 and at the same time acts as a beam compressor.

[0038] The first, second, third, and fourth light deflection surfaces 6a, 6b, 8a, and 8b are arranged such that a virtual surface intersecting the common first focal point fp1 and the common second focal point fp2 intersects the optical body 3 at the intersection line. The optical body 3 is configured such that the first light deflection surface 6a is higher (at a higher position) in the direction perpendicular to the intersection line than the third light deflection surface 8a. The first light deflection surface 6a and the third light deflection surface 8a are provided (formed) on the same side of the shell surface 3c of the optical body 3. The second light deflection surface 6b and the fourth light deflection surface 8b are provided (formed) on the same side of the shell surface 3c of the optical body 3. The first light deflection surface 6a and the second light deflection surface 6b have a concave curvature (concave downward in the vertical direction), and the third light deflection surface 8a and the fourth light deflection surface 8b have a convex curvature (protruding upward in the vertical direction).

[0039] FIG. 3 is a perspective view of the optical body 3 of the second embodiment. The box-shaped body (hexahedron) shown by the dotted line represents the actual optical body 3, which is a cut-out portion of the first pair of optical action surfaces 6 and the second pair of optical action surfaces 8.

[0040] FIG. 5 shows a second embodiment of the lighting device 1. FIG. 5 shows the lighting device of FIG. 4, but the light beam paths LB1 and LB2 are additionally shown. The upper, at least one light beam has a divergence d1 before entering the optical body 3. After the at least one light beam exits the optical body 3, the at least one light beam has a divergence d2. The divergence d2 is smaller than the initial divergence d1 because the at least one light beam expands in diameter or diverges while traveling through the optical body 3 along the beam path LB1.

[0041] The lower, second light beam has a divergence d3 before entering the optical body 3. After the second light beam exits the optical body 3, the second light beam has a divergence d4. The divergence d4 is larger than the initial divergence d3 because the second light beam is reduced (diameter-reduced) while traveling through the optical body 3 along the beam path LB2. The divergence d4 of the second (lower) light beam is further larger than the divergence d2 of the at least one light beam (the upper, first light beam). As a result, the upper light beam incident on the optical element 5a has reduced chromatic aberration.

[0042] FIG. 6 shows an example of a prior art lighting device having a standard planar optical body 3'. The upper light beam has a divergence d1' before entering the optical body 3'. After the upper light beam exits the optical body 3', it has a divergence d2', which is equal to the initial divergence d1'. The divergence of the upper light beam remains unchanged while traveling through the optical body 3' along the beam path LB1'.

[0043] The lower light beam has a divergence d3' before entering the optical body 3'. After the lower light beam exits the optical body 3', it has a divergence d4', which is equal to the initial divergence d3'. The divergence of the lower light beam remains unchanged while traveling through the optical body 3' along the beam path LB2'. In this example, because it is a planar optical body 3', d1' = d2' = d3' = d4'. As a result, the light beam(s) incident on the optical element 5a will have a higher (larger) chromatic aberration.

[0044] All or part of the above embodiments and examples can be described as the following appendices, but are not limited thereto. [Appendix 1] Lighting device for a motor vehicle headlamp for generating a light distribution. The lighting device is · A light source configured to emit at least one light beam in a main direction of the lighting device, · An optical body disposed downstream of the light source along the main direction, provided that the optical body is · A light incident portion for coupling (injecting) a light beam from the light source into the optical body, provided that the light incident portion is assigned to the light source and configured to couple a light beam from the assigned light source into the optical body such that a plurality of light rays forming the light beam are substantially parallel to each other and substantially parallel to the main direction after being coupled into the optical body. The parallel light beam has a first vertical length (width) in the main vertical cross-section when viewed in a state where the lighting device is properly mounted on the vehicle at the time of coupling into the optical body, provided that the main vertical cross-section is parallel to the main direction. · A light exit portion for separating (emitting) the light beam coupled into the optical body through the light incident portion from the inside to the outside of the optical body in the main direction. · A shell surface that defines (outlines) the optical body, provided that the shell surface is configured to deflect the light beam coupled into the optical body, and the shell surface extends between the light incident portion and the light exit portion. Including · An optical system including at least one optical element arranged downstream of the optical body along the main direction for receiving (receiving light from) the light beam emitted from the light exit portion of the optical body. Provided that the optical system is configured to project a light beam forward of the lighting device, and the optical system combined with the light source and the optical body is configured to generate the light distribution. Including The optical body includes a first pair of optical working surfaces for guiding the light beam coupled into the optical body through the light incident portion from the light incident portion to the light exit portion along a first light beam path. The first pair of optical working surfaces is composed of a first light deflection surface and a second light deflection surface. The first light deflection surface and the second light deflection surface are provided (formed) on the shell surface. The optical body includes a first surface (side) and a second surface (side) facing each other. The first light deflection surface is provided (formed) on the first surface of the optical body, and the second light deflection surface is provided (formed) on the second surface of the optical body. In the main vertical cross-section, the first light deflection surface follows (is along) a first parabola, the second light deflection surface follows (is along) a second parabola, and the first light deflection surface and the second light deflection surface are provided (formed) on the shell surface such that the first parabola and the second parabola have a common focus. The light beam traveling along (following) the first light beam path is incident on the first light deflection surface, deflected to the second light deflection surface, and the deflected light beam is incident on the second light deflection surface and deflected to the light emitting portion for separation from the inside to the outside of the optical body. The light emitting portion includes a first light emitting surface, and the first pair of optical action surfaces and the light emitting portion are arranged such that the light beam deflected by the second light deflection surface is incident on the first light emitting surface. The first light deflection surface, the second light deflection surface, and the first light emitting surface are configured such that a plurality of light rays forming a light beam are substantially parallel to each other and substantially parallel to the main direction after being separated (emitted) from the inside to the outside of the optical body. The separated parallel light beam has a second vertical length in the main vertical cross-section, and the second vertical length is greater than the first vertical length. [Appendix 2] In the lighting device described above, especially the lighting device described in Appendix 1, The light source is configured to emit a second light beam, and the optical body includes a second pair of optical action surfaces for guiding the second light beam coupled into the optical body through the light incident portion from the light incident portion to the light emitting portion along the second light beam path. The second light beam has a third vertical length in the main vertical cross-section when being coupled into the optical body. The second pair of optical action surfaces is composed of a third light deflection surface and a fourth light deflection surface. The third light deflection surface and the fourth light deflection surface are provided (formed) on the shell surface. The third light deflection surface is provided (formed) on the first surface of the optical body, and the fourth light deflection surface is provided (formed) on the second surface of the optical body. In the main vertical cross-section, the third light deflection surface follows a third parabola, the fourth light deflection surface follows a fourth parabola, and the third light deflection surface and the fourth light deflection surface are provided (formed) on the shell surface such that the third parabola and the fourth parabola have a common second focus. The second light beam traveling along the second light beam path is incident on the third light deflection surface, deflected toward the fourth light deflection surface, and the deflected second light beam is incident on the fourth light deflection surface and deflected toward the light exit portion for separation from the inside to the outside of the optical body. The light exit portion includes a second light exit surface, and the second pair of optical action surfaces and the light exit portion are arranged such that the light beam deflected by the fourth light deflection surface is incident on the second light exit surface. The third light deflection surface and the fourth light deflection surface are configured such that a plurality of light rays of the second light beam are substantially parallel to each other and substantially parallel to the main direction after being separated (emitted) from the inside to the outside of the optical body, and the separated substantially parallel light beams have a fourth vertical length in the main vertical cross-section, and the fourth vertical length is smaller than the third vertical length. [Appendix 3] In the lighting device described above, particularly in the lighting device described in Appendix 2, The first light deflection surface, the second light deflection surface, the third light deflection surface, and the fourth light deflection surface are arranged such that a virtual surface intersecting the common first focus and the common second focus intersects the optical body at the intersection line; the optical body is configured such that the first light deflection surface is at a position higher in the vertical direction relative to the intersection line than the third light deflection surface. [Appendix 4] In the lighting device described above, particularly in the lighting device described in Appendix 2 or 3, The generated light distribution includes a first partial light distribution and a second partial light distribution; at least one light beam separated from the first light exit surface to the outside forms the first partial light distribution; the second light beam separated from the second light exit surface to the outside forms the second partial light distribution. [Appendix 5] In the lighting device described above, particularly in the lighting device described in any one of Appendices 1 to 4, The generated light distribution is a light distribution for a low beam, and the vertical (direction) length (spread) of the light distribution for the low beam extends downward along the VV line from at least 0° to at least -10° at the VV line. [Appendix 6] In the lighting device described above, particularly in the lighting device described in Appendix 4 and 5 [Appendix 5 citing Appendix 4], The center of the first partial light distribution is closer to the 0° line of the VV line than the center of the second partial light distribution. [Appendix 7] In the lighting device described above, particularly in the lighting device described in any one of Appendices 2 to 6, The first light deflection surface and the third light deflection surface are arranged on the same surface of the shell surface of the optical body. [Appendix 8] In the lighting device described above, particularly in the lighting device described in any one of Appendices 2 to 7, The second light deflection surface and the fourth light deflection surface are arranged on the same surface of the shell surface of the optical body. [Appendix 9] In the lighting device described above, particularly in the lighting device described in any one of Appendices 2 to 8, The first light deflection surface and the second light deflection surface have a concave curvature, and the second light deflection surface and the fourth light deflection surface have a convex curvature. [Appendix 10] In the lighting device described above, particularly in the lighting device described in any one of Appendices 1 to 9, The plurality of light rays forming the at least one light beam have a first divergence along the main direction in the main vertical section; the plurality of light rays forming the at least one light beam have a second divergence in the main vertical section after being separated from the inside of the optical body to the outside; the second divergence is smaller than the first divergence. [Appendix 11] In the lighting device described above, particularly in the lighting device described in any one of Appendices 2 to 10, The plurality of light rays forming the second light beam have a third divergence along the main direction in the main vertical section; the plurality of light rays forming the second light beam have a fourth divergence in the main vertical section after being separated from the inside of the optical body to the outside; the fourth divergence is larger than the third divergence. [Appendix 12] An automotive headlamp including the lighting device described in any one of Appendices 1 to 11.

[0045] Within the framework of the entire disclosure of the present invention (including the claims and the drawings), based on its basic technical idea, modifications and adjustments of the embodiments are possible. Also, within the framework of the entire disclosure of the present invention, various combinations or selections (including "non-selections") of various disclosure elements (including each element of each claim, each element of each embodiment, each element of each drawing, etc.) are possible. That is, the present invention, of course, includes the entire disclosure including the claims and the drawings, and various deformations and modifications that a person skilled in the art could make in accordance with the technical idea of the present invention. In particular, regarding the numerical ranges described in this document, any numerical value or small range included within the said range should be construed as being specifically described even in the absence of separate description.

[0046] Furthermore, the reference numerals appended to the claims are solely for the purpose of assisting in the understanding of the invention, and it is not intended to limit the present invention to the embodiments and the illustrated examples.

[0047] Furthermore, the entire contents of the above-mentioned each document are incorporated herein by reference and are considered to be described herein.

Explanation of Reference Numerals

[0048] 1 Lighting device 2 Light source 3 Optical body 3a Light incident portion 3b Light exit portion 3c Shell surface 4 Light collection element 5 Optical system 6 First pair of optical action surfaces 6a First light deflection surface 6b Second light deflection surface 7a First light exit surface 7b Second light exit surface 8 Second pair of optical action surfaces 8a Third light deflection surface 8b Fourth light deflection surface fp1 Common first focus fp2 Common second focus v Main vertical section v1, v1' First vertical length v2, v2' Second vertical length v3 Third vertical length v4 Fourth vertical length LB1 First optical beam path LB2 Second optical beam path X Main direction

Claims

1. A lighting device for a motor vehicle headlamp for generating a light distribution, wherein the lighting device (1) comprises: - a light source (2) configured to emit at least one light beam in a main direction (X) of the lighting device (1); - an optical body (3) arranged downstream of the light source (2) along the main direction (X), provided that the optical body (3) comprises - a light incident portion (3a) for coupling a light beam from the light source (2) into the optical body (3), provided that the light incident portion (3a) is assigned to the light source (2) and configured to couple the light beam from the assigned light source (2) into the optical body (3) such that a plurality of light rays forming the light beam are substantially parallel to each other and substantially parallel to the main direction (X) after being coupled into the optical body (3). The parallel light beam has a first vertical length (v1, v1') in a main vertical section (v) when viewed in a state where the lighting device is properly mounted on a motor vehicle during the coupling into the optical body (3). Here, the main vertical section (v) is a plane parallel to the main direction (X) and perpendicular to a horizontal plane, and "vertical length" means the length of the light beam in the height direction. - a light exit portion (3b) for separating the light beam coupled into the optical body (3) through the light incident portion (3a) from inside the optical body (3) to the outside in the main direction (X); - a shell surface (3c) defining the optical body (3), provided that the shell surface (3c) is configured to deflect the light beam coupled into the optical body (3), and the shell surface (3c) extends between the light incident portion (3a) and the light exit portion (3b); and includes: - an optical system (5) including at least one optical element (5a) arranged downstream of the optical body (3) along the main direction (X) for receiving the light beam emitted from the light exit portion (3b) of the optical body (3), provided that the optical system (5) is configured to project the light beam forward of the lighting device (1), and the optical system (5) combined with the light source (2) and the optical body (3) is configured to generate the light distribution. and includes: The optical body (3) includes a first pair of optical action surfaces (6) for guiding a light beam coupled into the optical body (3) through the light incident portion (3a) along a first light beam path (LB1) from the light incident portion (3a) to the light exit portion (3b). The first pair of optical action surfaces (6) is composed of a first light deflection surface (6a) and a second light deflection surface (6b). The first light deflection surface (6a) and the second light deflection surface (6b) are provided on the shell surface (3c). The optical body (3) includes a first surface and a second surface that face each other. The first light deflection surface (6a) is provided on the first surface of the optical body (3), and the second light deflection surface (6b) is provided on the second surface of the optical body (3). In the main vertical section (v), the first light deflection surface (6a) follows a first parabola, and the second light deflection surface (6b) follows a second parabola. The first light deflection surface (6a) and the second light deflection surface (6b) are provided on the shell surface (3c) such that the first parabola and the second parabola have a common focus (fp1). The light beam following the first light beam path (LB1) is incident on the first light deflection surface (6a), deflected to the second light deflection surface (6b), and the deflected light beam is incident on the second light deflection surface (6b) and deflected to the light exit portion (3b) for separation from the inside to the outside of the optical body (3). The light exit portion (3b) includes a first light exit surface (7a). The first pair of optical action surfaces (6) and the light exit portion (3b) are arranged such that the light beam deflected by the second light deflection surface (6b) is incident on the first light exit surface (7a). The first light deflection surface (6a), the second light deflection surface (6b), and the first light exit surface (7a) are configured such that a plurality of light rays forming a light beam are substantially parallel to each other and substantially parallel to the main direction (X) after being separated from the inside to the outside of the optical body (3). The separated parallel light beam has a second vertical length (v2, v2') in the main vertical section (v), and the second vertical length (v2, v2') is larger than the first vertical length (v1, v1'). The light source (2) is configured to emit a second light beam, and the optical body (3) includes a second pair of optical action surfaces (8) for guiding the second light beam coupled into the optical body (3) through the light incident portion (3a) along a second light beam path (LB2) from the light incident portion (3a) to the light exit portion (3b). When the second light beam is coupled into the optical body (3), it has a third vertical length (v3) in the main vertical section (v). The second pair of optical action surfaces (8) is composed of a third light deflection surface (8a) and a fourth light deflection surface (8b). The third light deflection surface (8a) and the fourth light deflection surface (8b) are provided on the shell surface (3c). The third light deflection surface (8a) is provided on the first surface of the optical body (3), and the fourth light deflection surface (8b) is provided on the second surface of the optical body (3). In the main vertical section (v), the third light deflection surface (8a) follows a third parabola, and the fourth light deflection surface (8b) follows a fourth parabola. The third light deflection surface (8a) and the fourth light deflection surface (8b) are provided on the shell surface (3c) such that the third parabola and the fourth parabola have a common second focus (fp2). The second light beam following the second light beam path (LB2) is incident on the third light deflection surface (8a), deflected to the fourth light deflection surface (8b), and the deflected second light beam is incident on the fourth light deflection surface (8b) and deflected to the light exit portion (3b) for separation from the inside to the outside of the optical body (3). The light exit portion (3b) includes a second light exit surface (7b). The second pair of optical action surfaces (8) and the light exit portion (3b) are arranged such that the light beam deflected by the fourth light deflection surface (8b) is incident on the second light exit surface (7b). The third light deflection surface (8a) and the fourth light deflection surface (8b) are configured such that a plurality of light rays of the second light beam are substantially parallel to each other and substantially parallel to the main direction (X) after being separated from the inside to the outside of the optical body (3). The separated substantially parallel light beams have a fourth vertical length (v4) in the main vertical section (v), and the fourth vertical length (v4) is smaller than the third vertical length (v3). A lighting device, characterized by the above.

2. In the lighting device according to Claim 1, The first light deflection surface (6a), the second light deflection surface (6b), the third light deflection surface (8a), and the fourth light deflection surface (8b) are arranged such that a virtual surface that includes the common first focal point (fp1) and the common second focal point (fp2) and is perpendicular to the main vertical section (v) intersects the optical body (3). The optical body (3) is configured such that the first light deflection surface (6a) is at a relatively higher position in the vertical direction with respect to an intersection line, which is a line where the virtual surface intersects the first surface of the optical body (3), than the third light deflection surface (8a). An illumination device, characterized by the above.

3. In the illumination device according to claim 1, the generated light distribution includes a first partial light distribution and a second partial light distribution. At least one light beam separated from the outside from the first light emitting surface (7a) forms the first partial light distribution, and the second light beam separated from the outside from the second light emitting surface (7b) forms the second partial light distribution. An illumination device, characterized by the above.

4. In the illumination device according to claim 3, the generated light distribution is a light distribution for a low beam, and the vertical length of the light distribution for the low beam extends downward along the VV line from at least 0° to at least -10° on the VV line. An illumination device, characterized by the above.

5. In the illumination device according to claim 4, the center of the first partial light distribution is closer to the 0° line of the VV line than the center of the second partial light distribution. An illumination device, characterized by the above.

6. In the illumination device according to claim 1, the first light deflection surface (6a) and the third light deflection surface (8a) are arranged on the same surface of the shell surface (3c) of the optical body (3). An illumination device, characterized by the above.

7. In the illumination device according to claim 1, the second light deflection surface (6b) and the fourth light deflection surface (8b) are arranged on the same surface of the shell surface (3c) of the optical body (3). An illumination device, characterized by the above.

8. In the illumination device according to claim 1, the first light deflection surface (6a) and the second light deflection surface (6b) have a concave curvature, and the third light deflection surface (8a) and the fourth light deflection surface (8b) have a convex curvature. An illumination device, characterized by the above.

9. In the illumination device according to claim 1, The plurality of light rays forming the at least one light beam have a first divergence (d1) along the main direction (X) in the main vertical section (v), and the plurality of light rays forming the at least one light beam have a second divergence (d2) in the main vertical section (v) after being separated from the inside to the outside of the optical body (3), and the second divergence (d2) is smaller than the first divergence (d1), provided that "divergence" corresponds to the angle between adjacent light rays along the light propagation direction. A lighting device, characterized by the above.

10. In the lighting device according to Claim 1, the plurality of light rays forming the second light beam have a third divergence (d3) along the main direction (X) in the main vertical section (v), and the plurality of light rays forming the second light beam have a fourth divergence (d4) in the main vertical section (v) after being separated from the inside to the outside of the optical body (3), and the fourth divergence (d4) is larger than the third divergence (d3). A lighting device, characterized by the above.

11. An automotive headlamp including the lighting device (1) according to any one of Claims 1 to 10.

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