LIGHT GUIDE ASSEMBLY FOR A MOTOR VEHICLE

Technical Field

The present invention relates to the field of optical technology, specifically to a light guide assembly, a lighting and/or signal indicating device, and a motor vehicle.

Background Art

Light guides have come into increasingly wider use in the field of car lights to guide light from light sources and emit light outwards at desired positions. In addition to helping fulfil various predetermined lighting and/or signal indication functions, a light guide usually needs to cause the exhibition of various light output effects in a light output area, thereby matching the overall vehicle design, for example.

In order to achieve uniform light output intensity and desired lighting effect, in an existing car lamp, light given out by a light source often needs to be optically adjusted using a light guide before being emitted, which typically requires a specifically designed optical path in the light guide, so the light guide may take up a larger space; in addition, it is often necessary to passively adapt the shape of the light guide to an installation space (for example, forming a positive fit). Moreover, to achieve uniform emergent light, the surfaces of a light guide are usually subjected to optical processing, for example, being provided with arrays having small prisms or pillows on the surfaces as light distribution structures. Typically, these surfaces with light distribution structures are located on the outer wall of the light guide for convenient design and manufacturing; however, when the space for installing a light guide is limited, presence of light distribution structures on the outer wall may be unfavourable for the overall design of the light guide.

Summary The present invention provides a light guide assembly, a lighting and/or signal indicating device, and a motor vehicle to solve at least one problem in the prior art.

According to an embodiment of one aspect of the present disclosure, a light guide assembly is provided, comprising a first light guide and a second light guide which are coupled at an angle relative to each other, wherein the first light guide has a first end configured to receive light incident from outside the light guide assembly, and a second end located downstream of the first end and configured to emit the light towards the second light guide; the second light guide has an light incident end abutting and arranged at least partially facing the second end and configured to receive the light from the second end, and an light emitting end located downstream of the light incident end and configured to emit the light externally to the light guide assembly; the first light guide further has a first surface configured to reflect the light coupled from the first end towards the second end; and the second light guide further has a second surface configured to reflect light coupled from the light incident end towards the light emitting end.

According to one embodiment of the present disclosure, the light satisfies the total reflection condition at the first and second surfaces, respectively.

According to one embodiment of the present disclosure, the orientation of the second end and the light incident end is set such that their normal direction is consistent with the optical path followed by the light travelling towards the second end after being reflected from the first surface.

According to a further embodiment of the present disclosure, the orientation of the first surface is determined according to the Snell's law on the basis of at least the setting of the second surface.

According to a further embodiment of the present disclosure, the orientation of the first surface is determined according to the Snell's law additionally on the basis of the setting of the light emitting end.

According to a further embodiment of the present disclosure, the setting of the first surface comprises the angle of the first surface relative to the second surface, wherein the setting of the first surface depends on the critical angle at the second surface, the angle between the second surface and the light emitting end, the corresponding refractive index of the first and second light guides, and the refractive index of the environment in which the light guide assembly is located.

According to an embodiment of the present disclosure, the light emitting end is formed with a main emergence surface and a plurality of auxiliary emergence surfaces respectively abutting on the periphery of the main emergence surface.

According to an embodiment of the present disclosure, the first surface is arranged at an angle between the first end and the second end.

According to an embodiment of the present disclosure, the portion of the first light guide formed between the first end and the second end and at least partially facing the first surface is in a step shape or a transition surface with a smooth contour.

According to a further embodiment of the present disclosure, the step shape or the transition surface gradually shrinks or expands from the first end towards the second end.

According to a further embodiment of the present disclosure, on the basis of maintaining the desired output conditions at the main emergence surface, the second light guide is designed to compensate for changes in the light caused by a trend for gradual changes in the step shape or the transition surface.

According to a further embodiment of the present disclosure, in response to gradual shrinking of the step shape or the transition surface from the first end towards the second end, the second light guide is designed to gradually expand from the light incident end towards the light emitting end; and in response to gradual expansion of the step shape or the transition surface from the first end towards the second end, the second light guide is designed to gradually shrink from the light incident end towards the light emitting end.

According to an embodiment of the present disclosure, a gap is defined between the second end and the light incident end, and a light distribution structure is provided on at least one of the surface of the first light guide at the second end and the surface of the second light guide at the light incident end.

According to a further embodiment of the present disclosure, the light distribution structure comprises at least one of the following optical microstructures: a plurality of hemispherical or conical protrusions, a plurality of prismatic protrusions, a plurality of frosted granular protrusions, a plurality of bosses with trapezoidal sections, or a plurality of recessed mesh points.

According to a still further embodiment of the present disclosure, the at least one surface formed with the light distribution structure is a frosted surface, a textured surface, or a rugged surface.

According to an embodiment of the present disclosure, a plurality of collimators are formed at the first end of the first light guide.

According to a further embodiment of the present disclosure, the plurality of collimators are arranged in an array on a single incidence surface at the first end.

According to an embodiment of another aspect of the present disclosure, a lighting and/or signal indicating device is provided, comprising at least one light guide assembly as described above.

According to an embodiment of yet another aspect of the present disclosure, a motor vehicle is provided, comprising a lighting and/or signal indicating device as described above.

With an optical assembly and a lighting and/or signal indicating device according to an embodiment of the present disclosure, an optical path may be inversely derived on the basis of at least the setting of the second surface of the second light guide that meets the total reflection condition, and thus the setting of the first surface of the first light guide that meets the total reflection condition is determinable. Moreover, at the gap between the first and second light guides, one or both of the first and second light guides have an additionally arranged light distribution structure, which substantially achieves the internalization of the light distribution structure of the light guide assembly, thereby ensuring that the requirement for uniform emergent light is still met without arranging a light distribution structure on the outer wall of the entire light guide.

Brief Description of the Drawings

Referring to the accompanying schematic drawings, embodiments of the present disclosure will be described below by example only, where the corresponding reference signs in the drawings denote the corresponding components. A brief description of the drawings is as follows: [Fig. 1] is a schematic three-dimensional structural diagram of a light guide assembly according to an embodiment of the present disclosure;

[Fig. 2(a)] to [Fig. 2(d)] are respectively a front view, a top view, a right view, and a left view of the light guide assembly as shown in Fig. 1;

[Fig. 3] is a schematic diagram of a propagation path of light in the light guide assembly shown in Fig. 1 and Fig. 2(a) to Fig. 2(d), where light undergoes total internal reflection at the first surface of the first light guide and the second surface of the second light guide;

[Fig. 4(a)] to [Fig. 4(b)] are respectively schematic views of a light distribution structure on a surface arranged at a gap between the first and second light guides of the light guide assembly as shown in Fig. 3, wherein the light distribution structure shown in Fig. 4(a) is an optical microstructure (array), and the light distribution structure shown in Fig. 4(b) is a stepped part; [Fig. 5] is a partially enlarged view of the portion marked by a dashed circle O in the top view given in Fig. 2(b), showing collimators located at the first end of the light guide assembly for receiving external incident light;

[Fig. 6] is a schematic structural diagram of a lighting and/or signal indicating device comprising a light guide assembly according to an exemplary embodiment of the present disclosure.

Specific Embodiments

To more clearly expound the objective, technical solution and advantages of the present disclosure, embodiments of the present disclosure are described in detail below with reference to the drawings. It should be understood that the description of embodiments below is intended to explain and illustrate the general concept of the present disclosure, and should not be construed as limiting the present disclosure. In the specification and drawings, identical or similar reference labels denote identical or similar components or members. For clarity, the drawings are not necessarily drawn to scale, and certain well known components and structures might be omitted in the drawings.

Unless defined otherwise, the technical or scientific terms used in the present disclosure shall have the common meanings understood by those skilled in the art. Terms like "first" and "second" as used in the present disclosure, rather than denoting any sequences, quantities, or orders of importance, are only used to distinguish between different components. The word "a" or "one" does not rule out a plurality. Words such as "comprises" or "includes" mean that the element or object appearing before the word encompasses the elements or objects and their equivalents listed after the word, without excluding other elements or objects. Words such as "connected" or "linked" are not restricted to a physical or mechanical connection, and may include an electrical connection, whether direct or indirect. "Upper", "lower", "left", "right", "top" or "bottom", etc. are only used to indicate a relative positional relationship, and when the absolute position of the described object changes, the relative positional relationship might also change accordingly. When elements such as layers, films, regions or substrates are referred to as being located "on" or "under" another element, these elements may be "directly" located "on" or "under" another element, or there may be an intermediate element.

Fig. 1 is a schematic three-dimensional structural diagram of the light guide assembly 1 according to an embodiment of the present disclosure. In addition, Fig. 2 (a) to Fig. 2(d) are respectively a front view, a top view, a right view, and a left view of the light guide assembly 1 as shown in Fig. 1. Fig. 3 is a schematic diagram of a propagation path of light in the light guide assembly 1 shown in Fig. 1 and Fig. 2(a) to Fig. 2(d), where light undergoes total internal reflection at the first surface 13 of the first light guide 10 and the second surface 23 of the second light guide 20.

According to an overall technical concept of an embodiment of the present disclosure, for example, as shown in the figure, a light guide assembly 1 is provided, such as a light guide assembly 1 installed in a headlamp of a motor vehicle, which is intended to provide a light guide assembly 1 as follows: on the one hand, a portion of the light guide assembly 1 (for example, a portion thereof closer to the emergence side of the headlamp) is a leading edge exposed outwards from the frame of the headlamp, another portion of the light guide assembly 1 (for example, a portion thereof closer to the light source) is a portion hidden in the frame of the headlamp, and in actual usage scenarios, typically, the portion functioning as the leading edge occupies a larger part of the size of the entire light guide assembly 1 and, as it is usually exposed to the outside, has a customized appearance, which disallows an optical design for the exposed portion, so a design for achieving the functionality of light guide assembly 1 should mainly be created in said another portion of the light guide assembly 1 hidden inside the frame of the headlamp. In other words, the portion functioning as the leading edge is, for example, a free configuration, and said another part needs to, for example, be designed on the basis of the setting of the leading edge; in a specific embodiment, this is reflected in that an optical design for said another portion is based on the setting of the exposed leading edge, which means that the optical design is created in a direction opposite to the propagation path of light in the light guide assembly 1. On the other hand, the emergence surface of the light guide assembly 1 for light emission is located at the front end of the exposed portion, which, usually not along the vertical direction (namely the absolute Z direction), alternatively forms an angle (for example, 0 as shown in the figure) with the vertical direction; moreover, light propagating inside the light guide assembly 1 and ultimately reaching the emergence surface should also form a certain angle with the X direction (for example, relative to the horizontal plane) to ensure that the light is refracted at the emergence surface of the light guide assembly 1 and ultimately emitted along the horizontal direction.

Moreover, in order to save installation space, as an example, the above-described another portion hidden in the frame of the headlamp in the light guide assembly 1 is angled relative to the exposed portion, which means that the surface of the light guide assembly 1 for light incidence is also usually angled relative to the leading edge of the free configuration.

In the exemplary embodiments of the present disclosure, for example, as shown in Fig. 1 and Fig. 2(a) to Fig. 2(d), the light guide assembly 1 specifically comprises, for example, a first light guide 10 and a second light guide 20 that are coupled at an angle relative to each other. As an example, the first light guide 10 has a first end 11 and a second end 12, wherein the first end 11 is configured to receive light incident externally from the light guide assembly 1, and the second end is located downstream of the first end 11 and configured to emit the light towards the second light guide 20. Moreover, as an example, the second light guide 20 has an light incident end 21 and an light emitting end 22, wherein the light incident end 21 abuts and is arranged at least partially facing the second end 12 and is configured to receive the light from the second end 12, and the light emitting end 22 is located downstream of the light incident end 21 and is configured to emit the light towards the outside of the light guide assembly 1 in a direction parallel to the longitudinal direction along which the second light guide 20 extends (for example, the length direction of the second light guide 20 or the direction forming a certain angle, such as an acute angle of a specific value, with the length direction). Specifically, as further shown in Fig. 3, the first light guide 10 further has a first surface 13, for example, located between the first end 11 and the second end 12, and the first surface 13 is configured to reflect the light coupled from the first end 11 towards the second end 12; the second light guide 20 further has a second surface 23, for example, located between the light incident end 21 and the light emitting end 22, and the second surface 23 is configured to reflect light coupled from the light incident end 21 towards the light emitting end 22. In the light guide assembly 1, the light is reflected only twice, at the first surface 13 and the second surface 23, respectively, so, while the desired output condition is maintained for the light emitted at the light emitting end 22, the setting of the first surface 13 where the first reflection occurs in the first light guide 10 may be derived along the direction opposite to the propagation path of light in the light guide assembly 1 and on the basis of the setting of the second surface 23 where the second reflection occurs in the second light guide 20, which will be described in detail later. As an example, typically as a boundary condition, the light satisfies the total reflection condition at the first surface 13 and the second surface 23, respectively, for example, by arranging an additional coated layer, such as an aluminium-coated layer, at the first surface 13 and the second surface 23.

In a further embodiment, as an example, the orientation of the second end 12 and the light incident end 21 is set such that their normal direction is consistent with the optical path of the light travelling towards the second end 12 after reflection (more typically, total reflection, for example) from the first surface 13. In a more specific example, the orientation of the first surface 13 (for example, the orientation of the normal N1 of the first surface 13) is determinable according to the Snell's law additionally on the basis of the setting of the optical end 22.

With the above-described arrangement, as shown in Fig. 1 and Fig. 2(a) to Fig. 2(d), especially for example, on the basis of the schematic optical path shown in Fig. 3, the light guide assembly 1 is composed of a first light guide 10 (usually hidden) located on the rear side and a second light guide 20 (usually exposed) on the front side, which is typically equivalent to a thick-walled light guide, wherein a first surface 13 is formed between the first end 11 of the first light guide 10 for receiving incident light and the second end 12 for emitting light towards the second light guide 20, and the first surface 13, in terms of shape, is a transitional surface between the first end 11 and the second end 12 of the first light guide 10 and, in terms of optical function, functions as a first light guiding surface that guides the light towards the interface between the first light guide 10 and the second light guide 20 of the light guide assembly 1 through reflection, effectively serving as the back side of the thick-walled light guide. As an example, the first surface 13 may usually be arranged at an angle between the first end 11 and the second end 12. Moreover, the bottom surface of the second light guide 20 serves as a second guiding surface that, through reflection, further guides light from the interface between the first light guide 10 and the second light guide 20 from the light guide assembly 1 towards the light emitting end 22 of the second light guide 20 for light emission, effectively serving as the bottom surface of the thick-walled light guide.

Then, for example, in order to reduce light loss and improve light utilization on the one hand, and provide convenience in subsequent optical calculations and designs on the other hand, it is typically necessary to meet the total reflection condition at the first surface 13 of the first light guide 10 (equivalent to the back side of the thick-walled light guide) and the second surface 23 of the second light guide 20 (equivalent to the bottom surface of the thick-walled light guide).

On the basis of the integral light guide assembly 1 arranged as described above, the formula according to the Snell's law is:

Then, considering that the direction of the light emitted from the surface of the entire light guide assembly 1, that is, the surface at the light emitting end 22 of the second light guide 20, has been predetermined by the user, on the basis of the known settings of the second light guide 20, optical calculations may be performed in the direction opposite to the optical path to obtain the specific settings of the light propagating from the first light guide 10 into the second light guide 20 at the first surface 13 of the first light guide 10 serving as the back side of the light guide assembly 1 (the total internal reflection condition is also met at the first surface 13), especially when, typically for example, it is known that the total reflection condition is met at the second surface 23 of the second light guide 20 serving as the bottom surface of the light guide assembly 1. In other words, specifically, assuming that the settings of the light emitting end 22 of the second light guide 20 (including the orientation of the normal N2 of the surface at the light emitting end 22, for example, relative to the plane where the second surface 23 is located, as indicated by the substantially horizontal dashed line in Fig.

3) are known in advance, the setting conditions in which the light propagating from the first light guide 10 to the second light guide 20 must meet at the first surface 13 of the first light guide 10 are calculated on the basis of the settings at the second surface 23 where the total internal reflection of light occurs in the second light guide 20.

In an optional embodiment, as an example, the orientation of the second end 12 and the light incident end 21 is arranged such that their normal direction is consistent with the optical path of the light travelling towards the second end 12 after reflection (typically, total reflection, for example) from the first surface 13. With this arrangement, for example, as shown in Fig. 3, when the light guided towards the second light guide 20 at the first surface 13 of the first light guide 10 through reflection (typically, total reflection, for example) reaches the interface between the first light guide 10 and the second light guide 20 of the light guide assembly 1, the direction followed by the light path at the interface is consistent with the normal at the second end 12 of the first light guide 10 where the light exits and the normal at the light incident end 21 of the second light guide where the light enters, that is, normal emergence from the first light guide 10 and then normal incidence into the second light guide 20, so that transmission occurs at the interface only, which prevents any changes in optical path or light loss at the interface, while simplifying optical calculations.

In an exemplary embodiment of the present disclosure, as an example, as is clear from the schematic optical path in Fig. 3, once light is coupled into the first end 11 of the first light guide 10, reflection (for example, total internal reflection, hereinafter referred to as the first total reflection) occurs immediately at the first surface 13, and light is incident at a first incidence angle and reflected at a first reflection angle at the first surface 13; then, the light propagates through the interface between the first light guide 10 and the second light guide 20 of the light guide assembly 1 to be coupled into the light incident end 21 of the second light guide 20; subsequently, reflection (for example, total internal reflection, hereinafter referred to as the second total reflection) occurs again at the second surface 23, and light is incident at a second incidence angle and reflected at a second reflection angle at the second surface 23; then, the light propagates to the light emitting end 22 of the second light guide 20 and undergoes refraction (hereinafter referred to as the first refraction, the incidence angle corresponding to which is called a third incidence angle) for emergence.

An example of typical optical calculations set at the first surface 13, which are opposite to the optical path, will be described in detail below.

As a specific example, in a typical simplified calculation, for example, on the basis of the aforementioned settings, it is clear that considering that the bottom surface of the second light guide 20, which is commonly deemed to be the second surface 23, is a flat surface, the plane where reflection, for example, total internal reflection, from the second surface 23 occurs, is deemed to be equivalent to the second surface 23, so, for the second total reflection and the first refraction, the second surface 23, the plane of the area where the light emitted from the light emitting end 22 of the second light guide 20 is located (the slope angles in the area are the same), and the straight line connecting the incidence point on the second surface 23 to the portion on the light emitting end 22 for light emergence can jointly define a virtual triangle, as shown on the left side of Fig. 3, wherein the third incidence angle of the first refraction plus 90 degrees, the inclination angle of the plane where the first refraction occurs at the light emitting end 22 relative to the plane where the second surface 23 is located, and the complementary angle of the second reflection angle are equal to the values of the three internal angles of the virtual triangle, respectively; in other words, when the values of the first two angles are known, (for example, when the third incidence angle calculable on the basis of the refraction angle of the first refraction (namely the angle formed by emergent light with the normal of the exit part on the light emitting end 22), and the inclination angle of the plane where the first refraction occurs at the light emitting end 22 relative to the plane where the second surface 23 is located are known), the second reflection angle on the second surface 23 is obtainable.

In addition, as a specific example, in a typical simplified calculation, for example, on the basis of the aforementioned settings, especially, typically when the assumed condition in which "the orientation of the second end 12 and the light incident end 21 is set such that their normal direction is consistent with the optical path of the light travelling towards the second end 12 after reflection, for example, total reflection, from the first surface 13" is met, it is clear that for the first total reflection, the plane of the area where the reflection, for example, total internal reflection, occurs on the first surface 13 (the slope angles in the area are the same), the plane of the second surface 23, and the straight line connecting the incidence point of the first surface 13 to the incidence point of the second surface 23 define another virtual triangle, as shown on the right side of Fig. 3, wherein the complementary angle of the first reflection angle, the complementary angle of the second incidence angle, and the inclination angle of the plane where the total internal reflection occurs on the first surface 13, relative to the plane where the second surface 23 is located, are equal to the values of the three internal angles of said another virtual triangle; in other words, when the values of the first two angles are known (for example, when the first incidence angle that, which is the same as the first reflection angle, and the second reflection angle, which is the same as the second incidence angle, are known), the inclination angle of the plane where the total internal reflection occurs on the first surface 13 relative to the plane where the second surface 23 is located is determinable.

Therefore, in an exemplary embodiment of the present disclosure, for example, typically, the settings of the first surface 13 include, for example, the angle of the first surface 13 relative to the second surface 23, which is the inclination angle described above, wherein the setting of the first surface 13 depends, for example, on the critical angle at the second surface 23, the angle between the second surface 23 and the light emitting end 22, the corresponding refractive index of the first light guide 10 and the second light guide 20, and even the refractive index of the environment in which the light guide assembly 1 is located.

Moreover, in an exemplary embodiment of the present disclosure, for example, the light emitting end is formed with a centrally arranged main emergence surface 221 and a plurality of auxiliary emergence surfaces 222 abutting the periphery of the main emergence surface 221, respectively. As an example, the main emergence surface 221 comprises a large percentage, for example, over 60%, preferably 70% to 90%, or even over 90%, of the total area of the light emitting end for light emission, and the plurality of auxiliary emergence surfaces 222 are located on the periphery of the main emergence surface 221, abutting the main emergence surface 221 and on each other. Thus, substantially it may be deemed that the light emitting end is structured to have the shape of a polygonal prism. With this arrangement, light is reflected onto the light emitting end of the second light guide 20 through two total internal reflections at the first surface 13 of the first light guide and the second surface 23 of the second light guide, respectively, and when the light emitting end is observed from different perspectives, due to the optical superposition that occurs on the main emergence surface 221 and the plurality of auxiliary emergence surfaces 222, a 'bling-bling' effect similar to the blinking of light passing through and emitted by a crystal as it rotates (which means that the angle of observation changes accordingly) is produced, so the emergent light takes on a specific and aesthetically pleasing optical irradiation appearance, which may not only be used to generate emergent light as the HB/LB light of a current headlamp, but may also serve as other signal indicator light or decorative light.

Thus, on the basis of the aforementioned settings, for example, it is possible to, starting from the light emitting end 22 of the second light guide 20, which comprises a plurality of adjacent surfaces, perform reverse mapping on the basis of an optical path, that is, deriving the setting of the first surface 13 on which total internal reflection occurs, on the basis of the setting at the light emitting end 22 and the setting of the second surface 23 on which total internal reflection occurs.

In addition, considering that the surface at the light emitting end 22 is defined by splicing the main emergence surface 221 and a plurality of auxiliary emergence surfaces 222, specific settings obtained at the first surface 13 can correspond to the range of inclination angles at the first surface 13, so, for example, the first surface 13 may be optionally implemented in the form of a single plane or surface or a plurality of planes or surfaces spliced together.

In an exemplary embodiment of the present disclosure, for example, the portion of the first light guide 10 that is formed between the first end 11 and the second end 12, and at least partially faces the first surface 13 is arranged in a step shape, typically a step shape shrinking outwards stepwise as shown in Fig. 1. This stepped local contour has at least two steps 14 that overlap and gradually shrink outwards, each having, for example, a polygonal cross-section, such as a quadrilateral, or alternatively, another shape, such as a ring.

As an example, with such a step shape, which gradually shrinks between the first end 11 and the second end 12 of the first light guide 10, it is possible to shrink the light coupled from the first end 11 of the first light guide 10, which, for example, causes the light to propagate towards the first surface in a gradually convergent manner after entering the first light guide 10, and facilitates the incidence of the light in a relatively centralized manner onto a limited area on the first surface, where it is reflected to exhibit the optical characteristic that the light reflected for the first time tends to be uniform, without the need for an additional collimator at the first end 11 on the first light guide 10 into which the light is coupled; meanwhile, this is also beneficial to controlling the volume of the first light guide 10 and thus saving the space needed to install it.

Moreover, with the local contour of such a step-like arrangement that gradually shrinks outwards, it is possible to, without any additional treatment of the portion (for example, without coating it with an additional specular membrane layer for reflection treatment), control leakage of light at the step portion and cause the light to exit dispersively, so as to avoid the formation of any unexpected bright spots at this location, which may affect the light utilization efficiency of the entire light guide and impair the overall lighting effect of the light guide.

Alternatively, the step shape into which the portion of the first light guide 10 between the first end 11 and the second end 12 and at least partially facing the first surface 13 is arranged may also be designed as a step shape that expands outwards stepwise from the first end 11 towards the second end 12, for example, having at least two steps that overlap at least partially and gradually expand outwards stepwise, each having, for example, a polygonal cross-section, such as a quadrilateral, or alternatively, another shape, such as a ring.

Correspondingly, considering the expectation of maintaining stable light output conditions at the light emitting end 22 of the second light guide 20 of the light guide assembly 1, the second light guide 20 is typically designed to compensate for changes in the light caused by a trend for gradual changes in the step shape, for example.

Specifically, for example, in response to the step shape of the first light guide 10 being designed to gradually shrink from the first end 11 towards the second end 12, the second light guide 20 is correspondingly designed to gradually expand from the light incident end 21 towards the light emitting end 22. Alternatively, in response to the step shape or the transition surface gradually expanding from the first end (11) towards the second end (12), the second light guide (20) is designed to gradually shrink from the light incident end (21) towards the light emitting end (22). In a more specific embodiment, as an example, when the portion of the first light guide 10 between the first end 11 and the second end 12 is designed with a step shape that gradually shrinks towards the downstream of the optical path, the portion of the second light guide 20 between the light incident end 21 and the light emitting end 22 is designed with a cross- sectional profile that gradually expands towards the downstream of the optical path.

With this arrangement, if the light coupled into the light guide assembly 1 propagates in a gradually convergent manner towards the first surface in the first light guide assembly 10 due to the gradually shrinking step shape between the first end 11 and the second end 12 of the first light guide assembly 10, then once the light is coupled out from the second end 12 of the first light guide assembly 10 and then coupled into the light incident end 21 of the second light guide assembly 20, the light coupled into the second light guide 20 propagates towards the second surface in a gradually divergent manner due to the gradually expanding cross-sectional profile between the light incident end 21 and the light emitting end 22 of the second light guide 20, as well as towards the light emitting end 22 after reflection at the second surface, and this arrangement facilitates the formation of parallel outgoing beams with consistent optical characteristics from the light emitting end 22 (especially, mainly from the main emergence surface 221 at the light emitting end 22) after the second reflection of the light. In addition, this arrangement is suitable for situations where the first light guide 10 is hidden in a limited space within the frame of the headlamp, while the installation space of the second light guide 20 exposed from the frame of the headlamp is not particularly limited.

In an alternative, more specific embodiment, as an example, when the portion of the first light guide 10 between the first end 11 and the second end 12 is designed with a step shape that gradually expands towards the downstream of the optical path, the portion of the second light guide 20 between the light incident end 21 and the light emitting end 22 is designed with a cross-sectional profile that gradually shrinks towards the downstream of the optical path.

With this arrangement, the light coupled into the first light guide 10 propagates in a gradually dispersive manner towards the first surface in the first light guide assembly 10 due to the gradually expanding step shape between the first end 11 and the second end 12 of the first light guide assembly 10, and then the light, after being coupled into the second light guide 20, due to the gradually shrinking cross-sectional profile of the second light guide 20 between the light incident end 21 and the light emitting end 22, propagates towards the second surface in a gradually convergent manner and, after reflection at the second surface, towards the light emitting end 22, which facilitates the formation of parallel outgoing beams with consistent optical characteristics from the light emitting end 22 (especially, mainly from the main emergence surface 221 at the light emitting end 22) after the second reflection of the light. In addition, this arrangement is suitable for situations where the installation space of the first light guide 10 hidden in the frame of the headlamp is not particularly limited, while the installation space of the second light guide 20 exposed from the frame of the headlamp is limited.

In another optional exemplary embodiment of the present disclosure, for example, the portion of the first light guide 10 that faces at least part of the first surface 13 (the portion, for example, is formed between the first end 11 and the second end 12) is a transition surface with a smooth contour (not shown). Further, as an example, the transition camber gradually shrinks or expands from the first end 11 towards the second end 12.

Correspondingly, considering the expectation of maintaining stable light output conditions at the light emitting end 22 of the second light guide 20 of the light guide assembly 1, the second light guide 20 is typically designed to compensate for changes in the light caused by a trend for gradual changes in the transition camber, for example.

Specifically, for example, in response to the step shape or the transition camber gradually shrinking from the first end 11 towards the second end 12, the second light guide 20 is designed to gradually expand from the light incident end 21 towards the light emitting end 22. Alternatively, for example, in response to the step shape or the transition camber gradually expanding from the first end 11 towards the second end 12, the second light guide 20 is designed to gradually shrink from the light incident end 21 towards the light emitting end 22. The effects of the transition camber on incident light and the design of the first and second light guides are similar to those of the step shape. The effects of the transition camber on incident light and the design of the first and second light guides are similar to those of the step shape. Specifically, the transition camber that gradually shrinks between the first end and the second end has an effect similar to a step shape that gradually shrinks between the first end and the second end; the transition camber that gradually expands between the first end and the second end has an effect similar to a step shape that gradually expands between the first end and the second end, which will not be described again herein.

The above-described step shape and transition surface are typically used in a case where no collimator is arranged at the light incident end 11 of the first light guide 10 of the light guide assembly 1. In addition, optionally, when collimators are arranged at the light incident end 11, as shown in Fig. 1 and Fig. 5, the step shape and transition camber may also be arranged simultaneously.

Further, for example, the inclination angle of a side of a step may be designed as needed. The sides of at least one step are inclined, and the inclination angle of each side may be freely selected as needed, which means that the sides of different steps can have different inclination angles, and that the sides of the same step can also have different inclination angles.

Alternatively or additionally, for example, the transition surface between adjacent steps extends along the circumferential direction of each step, wherein the transition surface may also be formed in a stepped manner.

Fig. 4(a) to Fig. 4(b) are respectively schematic views of a light distribution structure 31 on a surface arranged at a gap 30 between the first light guide 10 and the second light guide 20 of the light guide assembly 1 as shown in Fig. 3, wherein the light distribution structure shown in Fig. 4(a) is an optical microstructure (array), and the light distribution structure shown in Fig. 4(b) is a stepped part.

In an exemplary embodiment of the present disclosure, for example, as shown in Fig. 4(a) to Fig. 4(b), the second end 12 of the first light guide 10 and the light incident end 21 of the second light guide 20 abut each other, with a gap 30 defined therebetween, and at least one of the surface of the first light guide 10 at the second end 12 and the surface of the second light guide 20 at the light incident end 21 is provided with a light distribution structure 31.

In a further embodiment, as an example, as shown in Fig. 4(a), the light distribution structure 31 comprises at least one type of the following optical microstructures: a plurality of hemispherical or conical protrusions, a plurality of prismatic protrusions, a plurality of frosted granular protrusions, a plurality of bosses with trapezoidal sections, or a plurality of recessed mesh points. Alternatively or additionally, as shown in Fig. 4(a), at least one surface formed with the light distribution structure 31 is a frosted surface, a textured surface, or a rugged surface.

However, the present disclosure is not limited thereto, wherein, as long as the uniformity of light intensity distribution is improvable at the interface to obtain an expected light form, the specific form of any optical microstructure that can serve as the light distribution structure 31 is not limited in the present disclosure.

This arrangement makes it convenient to achieve a uniform distribution of light coupled from the first light guide 10 to the second light guide 20 on the cross-section at the interface between the first light guide 10 and the second light guide 20 of the light guide assembly 1, thereby achieving uniformity in the intensity distribution and optical efficiency of the light ultimately emitted from the light emitting end 22 of the second light guide 20. In addition, since the light distribution structure 31, which is arranged at the gap 30 between different parts inside the light guide assembly 1, is used instead of a commonly used light distribution structure 31 arranged on the outer side of the thick-walled light guide (for example, the back side of the thick-walled light guide) in a conventional arrangement in this field, uniform distribution of light is obtained while ensuring that the surface of the light guide has no attached light distribution structure 31, which needs to be additionally processed, thereby making the surface of the light guide smooth and facilitating processing.

Alternatively or additionally, in order to achieve a uniform distribution of light coupled from the first light guide 10 to the second light guide 20 on the cross-section at the interface between the first light guide 10 and the second light guide 20 of the light guide assembly 1, in another exemplary embodiment of the present disclosure, and also as another example of the light distribution structure 31, as shown in Fig. 4(b), the second end 12 of the first light guide 10 and the light incident end 21 of the second light guide 20 may each have corresponding step portions in places where they abut each other, and the step portions of the second end 12 and the light incident end 21 overlap in an abutting state, wherein, specifically, for example, the outermost first step 15 of the first light guide 10 at the second end 12 forms a positive fit with the innermost second step 26 of the second light guide 20 at the light incident end 21, and the innermost second step 16 of the first light guide 10 at the second end 12 forms a positive fit with the outermost second step 25 of the second light guide 20 at the light incident end 21.

Herein, ""overlap"" may be understood as follows: at the interface between the first light guide 10 and the second light guide 20 of the light guide assembly 1, the projections of the corresponding step portions of these two light guide elements on the imaginary plane transverse to the direction of light emission overlap at least partially, allowing light leaving one light guide element in the gap 30 at the interface to enter the other light guide element, thereby ensuring uniformity of light emission. This solution makes it possible to achieve improved optical mixture at a junction, thereby producing a light output effect that is as consistent as possible with those of other light output areas. In fact, it is acceptable as long as adjacent light guide elements have overlapping parts in the gap 30 at the interface, so that light leaving one light guide element can at least partially enter the other light guide element. In other words, it is acceptable as long as adjacent light guide elements have complementary shapes in a junction zone.

Fig. 5 is a partial enlarged view of the area marked by a dashed circle O in the top view given in Fig. 2(b), showing collimators located at the first end of the light guide assembly for receiving external incident light.

In an exemplary embodiment of the present disclosure, as shown in Fig. 5, as an example, a plurality of collimators 40 are formed at the first end 11 of the first light guide 10. In a further specific embodiment, for example, the plurality of collimators 40 are arranged in an array on a single incidence surface at the first end 11. With this arrangement, collimated beams passing through the array of collimators 40 are coupled in parallel into the first light guide 10 shown, helping achieve uniformity of light intensity distribution later.

In an embodiment of the present disclosure, for example, as shown in the figure, each light guide in the light guide assembly 1 is an extension light guide extending in a single direction. For example, each light guide comprises a transparent body extending in a single specific direction. It may extend along a straight line, a curved line or a combination of the two. A cross section thereof may adopt various shapes, e.g. circular, elliptical or polygonal.

As an example, each light guide in the light guide assembly 1 may be made of a transparent material. For example, the light guide is an integrated component made of a single transparent glass, resin, or plastic, such as polymethyl methacrylate (PMMA), polymethyl acrylate (PMA) or polycarbonate, inorganic or organic glass.

Fig. 6 is a schematic structural diagram of a lighting and/or signal indicating device 2 comprising the light guide assembly 1 according to an exemplary embodiment of the present disclosure.

According to the overall concept of an embodiment of the present disclosure, in another aspect of the present disclosure, for example, as shown in Fig. 6, a lighting and/or signal indicating device 2 is further provided, comprising a light source 3, which is a high beam (HB)/low beam (LB), for example; and at least one light guide assembly 1 as described above. In an exemplary embodiment of the present disclosure, as an example, the light source 3 may comprise a white light or monochromatic light-emitting diode, for example, or may also be another light source known in the art, for example, an incandescent lamp.

Such a lighting and/or signal indicating device, by comprising a light guide assembly 1 as described above, has all the advantages and technical effects of the aforementioned optical assembly, wherein, especially for example, on the one hand, when the light emitting end is observed from different perspectives, due to the optical superposition that occurs on the main emergence surface 221 and the plurality of auxiliary emergence surfaces 222, a 'bling-bling' effect similar to the blinking of light passing through and emitted by a crystal as it rotates (which means that the angle of observation changes accordingly) is produced, so the emergent light takes on a specific and aesthetically pleasing optical irradiation appearance; on the other hand, a light distribution structure 31 for homogenizing the light intensity distribution is formed on at least one surface at an internal gap 30 between different light guides forming the light guide assembly 1. The achievement of these technical effects is as mentioned earlier and will not be described again herein.

According to yet another aspect of an embodiment of the present disclosure, a motor vehicle is further provided, comprising a lighting and/or signal indicating device as described above. The motor vehicle further comprises, for example, a vehicle body, in which the lighting and/or signal indicating device is installed. Since the motor vehicle comprises the above-described lighting and/or signal indicating device, especially the above-described light guide assembly 1, it has all the advantages and technical effects of the light guide assembly 1 and the lighting and/or signal indicating device, which will not be described again herein. Although the present disclosure has been explained in conjunction with the drawings, the embodiments disclosed in the drawings are intended to provide an exemplary illustration of preferred embodiments of the present disclosure, and must not be interpreted as a limitation of the present disclosure.

Although some embodiments of the general concept of the present disclosure have been shown and explained, those skilled in the art will understand that changes may be made to these embodiments without departing from the principles and spirit of the general concept. The scope of the present disclosure is defined by the claims and their equivalents.