CN111856641A

CN111856641A - Light guide, light emitting device comprising the same, and motor vehicle

Info

Publication number: CN111856641A
Application number: CN201910350402.7A
Authority: CN
Inventors: 邬斯华; 张冰; 代亮
Original assignee: Valeo Lighting Hubei Technical Center Co Ltd
Current assignee: Valeo Lighting Hubei Technical Center Co Ltd
Priority date: 2019-04-28
Filing date: 2019-04-28
Publication date: 2020-10-30
Anticipated expiration: 2039-04-28

Abstract

The invention provides a light guide (100), a light emitting device and a motor vehicle, the light guide (100) comprising: a main body (11); a light incident surface (13), the light incident surface (13) being provided on an end side of the main body (11); and a light exit side (14), the light exit side (14) being located on a circumferential side of the main body (11), the light entrance surface (13) being configured with a concave surface that is recessed toward the inside of the main body (11), the concave surface being formed by a generatrix along the guidance of at least two closed guide lines, wherein, as seen in the recessed direction, a contour of a frontmost guide line is smaller than a contour of a rearmost guide line, and a line connecting centers of regions surrounded by the closed guide lines is not in one plane with the generatrix. According to the light guide of the present invention, the uniformity of light extraction is improved.

Description

Light guide, light emitting device comprising the same, and motor vehicle

Technical Field

The present invention relates to the technical field of motor vehicles and light emitting devices, in particular to a light guide, a light emitting device comprising the light guide and a motor vehicle comprising the light emitting device.

Background

The lighting devices of motor vehicles encompass various lighting and/or signaling devices, such as headlights, fog lights, turn signals, brake lights, tail lights, position lights, daytime running lights, etc. of the vehicle. In the case of motor vehicle lighting devices, light guides are used as a common optical element for guiding light rays in order to produce the desired optical shape.

Generally, in addition to ensuring a certain optical efficiency, the light guide is expected to have a high uniformity of the light exiting the light exit surface. Designers have found that light extraction uniformity is related to a number of factors and often conflicts with light extraction efficiency, on the one hand requiring more efficient scattering of light for improved uniformity, which results in more light loss, and on the other hand, desiring less light loss, which results in less uniform mixing of the light. Conventional light guide light input surfaces are configured as flat surfaces, a portion of the light rays do not enter the light guide, and thus the optical efficiency is low, and the light output uniformity of such light guides is poor.

Disclosure of Invention

It is an object of the present invention to at least partly overcome the drawbacks of the prior art and to provide a light guide with improved uniformity of the light emission.

It is also an object of the present invention to provide a light guide having high light extraction efficiency while ensuring good light extraction uniformity.

The invention also aims to provide a light-emitting device with better optical performance.

It is also an object of the invention to provide a motor vehicle with a better lighting effect.

To achieve one of the above objects or purposes, the technical solution of the present invention is as follows:

A light guide, comprising:

a main body;

a light incident surface provided at an end side of the main body; and

a light exit side located at a circumferential side of the main body,

the light incident surface is configured with a concave surface recessed toward the inside of the main body, the concave surface is formed by guiding a bus bar along at least two closed guide lines, wherein, as viewed in a recessed direction, a contour of a frontmost guide line is smaller than a contour of a rearmost guide line, and a connecting line of centers of regions surrounded by the closed guide lines is not in one plane with the bus bar.

In one embodiment, the guide wire is circular, regular polygonal, or formed by a combination of arc segments and straight lines. Here, the above-mentioned centers may be their geometric centers or geometric centers of gravity.

In one embodiment, the bus bar is a straight line or a curved line.

In one embodiment, the line joining the centers of the cross-sections of the concavities is parallel to or coincident with the longitudinal axis of the body.

In one embodiment, a plurality of concavities, in particular an array, are formed at the light entry surface.

In an embodiment, the depth of the concave surface is less than twice the diameter of the body of the light guide.

In one embodiment, the body of the light guide has a circular cross-section and the rearmost guideline is a regular polygon inscribed in the cross-section.

According to another aspect of the present invention, there is provided a light emitting device comprising a light guide according to any one of the preceding embodiments.

According to a further aspect of the invention, there is provided a motor vehicle comprising a light emitting device according to any one of the preceding embodiments.

According to the light guide of the present invention, the light incident surface is configured as a concave surface recessed toward the inside of the main body, so that incident light from the light source is better mixed at the light incident surface, and thus, uniformity of light emission is improved; moreover, the light loss is small by utilizing the convergence effect of the concave surface, so that the light-emitting efficiency is high under the condition of ensuring better light-emitting uniformity. Further, the light incident surface is designed to be twisted around the central line, and the twisted light incident surface can realize better mixing of light rays, so that better light emitting uniformity is brought. In addition, the light-emitting device according to the invention has better optical performance, and the motor vehicle according to the invention has better lighting and/or signal indicating effect.

Drawings

FIG. 1a is a front view of a light guide according to an embodiment of the present invention;

FIG. 1b is a bottom view of a light guide according to an embodiment of the present invention;

FIG. 1c is a right side view of a light guide according to an embodiment of the present invention;

FIG. 2 is an enlarged view more clearly showing the bus bars and guide lines of the light guide according to an embodiment of the present invention;

FIG. 3 is a side view of the light guide shown in FIG. 2;

FIG. 4 is a schematic cross-sectional view of the light guide shown in FIG. 1a taken along section B-B;

FIG. 5 is an optical path diagram of a light guide according to an embodiment of the present invention;

FIG. 6 is a left side view of one example of a light incident surface of a light guide according to an embodiment of the present invention;

FIG. 7 is a left side view of one example of a light incident surface of a light guide according to an embodiment of the present invention;

FIG. 8 is a left side view of one example of a light incident surface of a light guide according to an embodiment of the present invention;

fig. 9 is a perspective view of a light emitting device according to an embodiment of the present invention; and

fig. 10 is a front view of a light emitting device according to an embodiment of the present invention.

Detailed Description

Exemplary embodiments of the present invention will be described in detail below with reference to the attached drawing figures, wherein like reference numbers indicate functionally identical or similar elements. Furthermore, in the following detailed description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the embodiments of the disclosure. It may be evident, however, that one or more embodiments may be practiced without these specific details. In other instances, well-known structures and devices are shown in schematic form in order to simplify the drawing.

Fig. 1a-1c show a front view, a bottom view and a right side view, respectively, of a light guide according to an embodiment of the invention. Light guide 100 includes a body 11, an optical tooth 12, an in-light surface 13, and an out-light side 14. The main body 11 is substantially elongated, the light incident surface 13 is disposed at one end of the main body 11, and the light emitting side 14 is located at a different side of the main body 11 from the light incident surface 13. Specifically, the light incident surface 13 is at one end of the elongated body 11 in the longitudinal direction thereof, the light emitting side 14 is disposed on a substantially cylindrical surface of the elongated body 11, and the optical teeth 12 are disposed on the opposite side of the body 11 from the light emitting side 14. In the present embodiment, the optical tooth 12 extends in the longitudinal direction of the main body 11 and comprises a plurality of linearly arranged sub-teeth, the optical tooth 12 being configured to totally reflect light rays entering the light guide 100 and to change the propagation direction of the light rays such that the reflected light exits the light guide at least partially from the light exit side 14.

It should be noted that the present embodiment is described with reference to an elongated light guide, but the light guide may have other shapes, including but not limited to a block shape, a bent strip shape, a sheet shape, etc., as long as it has a light incident surface and a light emitting surface, and can guide and transmit light entering the light guide.

Fig. 4 is a schematic cross-sectional view of the light guide shown in fig. 1a, taken along the plane B-B, and as shown in fig. 4, the light incident surface 13 is configured as a concave surface recessed toward the inside of the body 11, thereby forming a hollow open space at one end of the body 11, and the structure of the optical teeth 12 can be more clearly seen in fig. 4. In this embodiment, the concave surface includes a bottom surface and a side surface, which are clearly separated, and alternatively, the concave surface may be a conical surface, a spherical crown surface, or a plurality of planes or sub-curved surfaces connected together, as long as the concave surface is recessed into the main body 11 as a whole.

According to the light guide of the present invention, the light incident surface is configured as a concave surface recessed toward the inside of the main body, so that incident light from the light source is better mixed at the light incident surface, and thus, uniformity of light emission is improved; moreover, the light loss is small by utilizing the convergence effect of the concave surface, so that the light-emitting efficiency is high under the condition of ensuring better light-emitting uniformity.

Here, the light guide 100 may be made of an at least partially transparent glass, resin or plastic material, such as PMMA (polymethyl methacrylate), polycarbonate, or the like. In this embodiment, the light guide 100 may be supported or suspended by any known suitable means for holding optical elements, such as a stand, a boom, or the like. Light guide 100 may be molded using a mold or may be manufactured using other methods known in the art.

Preferably, the light incident surface 13 is twisted in a direction from the light incident surface 13 to the body 11 or in a main direction of light incidence, i.e. the concave surface is rotated while being recessed into the body 11. FIG. 1c is a right side view of the light guide 100 from which perspective the concave surface rotates slightly clockwise as it travels from the outer edge to the inner edge; alternatively, the concave surface may also rotate counterclockwise as it travels from the outer edge to the inner edge.

To create a twisting effect, in one embodiment of the invention, said concave surface is formed by a generatrix 134 guided along at least two closed guide lines 133, wherein the contour of the frontmost guide line 133 is smaller than the contour of the rearmost guide line 133 seen in the direction of the recess, and the line connecting the centers of the areas enclosed by the closed guide lines 133 is not in one plane with said generatrix 134, see fig. 2. The center is understood here to mean the geometric center or the geometric center of gravity of the contour enclosed by the guide line.

The guide line 133 may be circular, regular polygonal, or formed by a combination of arc segments and straight lines, and the generatrix 134 may be a straight line or a curved line. In one embodiment, a line connecting the centers of the cross-sections of the concavities is parallel to or coincident with the longitudinal axis of the body. Preferably, the depth of the concave surface is less than twice the diameter of the body of the light guide.

In a particular embodiment, the body 11 of the light guide has a circular cross-section, the rearmost guideline 133 being a regular polygon inscribed in this cross-section, see for example the following fig. 7. Advantageously, a plurality of concave surfaces are configured in an array at said light entry surface 13, see fig. 8.

Therefore, in the case where the guide line is polygonal, the light incident surface 13 is designed to include a plurality of flap surfaces 131, adjacent sides of the adjacent flap surfaces 131 meet, and the sides of the flap surfaces 131 do not intersect with the axis of the main body 11 but are offset from the axis by a certain distance. The centre of the area circumscribed by the guide wire profile may be eccentric with respect to the axis of the body 11. Therefore, the plurality of flap faces 131 are not rotationally symmetric (centrosymmetric) with respect to the longitudinal axis of the body 11, and are also not axisymmetric with respect to a line perpendicular to the longitudinal axis of the body 11.

The concave surface may also be configured to have a profile of a frustum shape, and specifically, the light incident surface 13 may include a plurality of flap surfaces 131 and a bottom surface 132, adjacent sides of the adjacent flap surfaces 131 meet, and one end of all the flap surfaces 131 near the main body 11 meets the bottom surface 132. The bottom surface 132 serves as the upper top surface of the frustum, i.e. the top surface with the smaller diameter, and the combination of the plurality of flap surfaces 131 forms the side surfaces of the frustum, the lower surface of which is open, see fig. 1 c. Thus, the plurality of flap surfaces 131 are rotationally symmetric (centrosymmetric) with respect to the longitudinal axis of the body 11 and non-axisymmetric with respect to a line perpendicular to the longitudinal axis of the body 11.

Through being the income plain noodles design for forming the distortion shape, the income plain noodles of distortion brings better light-emitting homogeneity.

The bottom surface 132 may be a circular plane, in which case, the side of the flap surface 131 close to the main body 11 is a circular arc, and a plurality of sides of the flap surfaces 131 close to the main body 11 enclose a circle. The bottom surface 132 may also be a polygonal plane, in this case, the side of the flap surface 131 close to the main body 11 may be a straight line, and a plurality of straight lines of the plurality of flap surfaces 131 close to the main body 11 enclose a polygon, for example, the bottom surface 132 is a quadrangle, in which case there are four flap surfaces 131, and further, for example, the bottom surface 132 is a hexagon, in which case there are six flap surfaces 131.

Advantageously, the bottom surface 132 is a curved surface recessed into the body 11 to a lesser extent than the side surface formed by the plurality of flap surfaces 131 is recessed into the body 11. In this way, incident light from the light source is more likely to enter the light guide 100. Alternatively, the bottom surface 132 is also configured to include a plurality of flap surfaces, and adjacent sides of the adjacent flap surfaces meet, i.e., the bottom surface 132 is configured similarly to the side surfaces of the concave surface (i.e., the plurality of flap surfaces 131), whereby the concave surface includes two concave surfaces recessed into the main body 11, a first-stage concave surface and a second-stage concave surface, the second-stage concave surface being further recessed into the main body 11 on the basis of the first-stage concave surface, and the angle of the first-stage concave surface to the axis of the main body 11 is smaller than the angle of the second-stage concave surface to the axis of the main body 11. Similarly, the concave surface may include three concave surfaces recessed into the main body 11, that is, a first-stage concave surface, a second-stage concave surface and a third-stage concave surface, the first-stage concave surface is close to the outer side of the main body 11, the third-stage concave surface is close to the inner side of the main body 11, the second-stage concave surface is located between the first-stage concave surface and the third-stage concave surface, an included angle between the first-stage concave surface and the axis of the main body 11 is smaller than an included angle between the second-stage concave surface and the axis of the main body 11, and an included angle between the second-stage concave surface and the.

Alternatively, the plurality of flap surfaces 131 may intersect at a point, but in order to produce a light mixing effect, the intersection point is eccentric with respect to the axis of the body 11. In the embodiment where the plurality of flaps 131 and the bottom surface 132 form a frustum (in this case, the plurality of flap surfaces 131 do not intersect at a point), the structure formed by the plurality of flaps may be eccentric, for example, the center of the bottom surface 132 is offset from the axis of the body 11. The areas of adjacent flap surfaces 131 are different whether the intersection point is off-center with respect to the axis of the body 11 or the center of the bottom surface 132 is off-center with respect to the axis of the body 11.

In the case where the optical tooth 12 is provided on the side of the body 11 opposite to the light exit side 14, it is preferable that the center of the bottom surface 132 is offset in a direction approaching the optical tooth 12 with respect to the axis of the body 11, or the apex of the conical surface is offset in a direction approaching the optical tooth 12 with respect to the axis of the body 11.

Further, the petal surface 131 is provided with a microstructure unit, which may be a plurality of concave particles recessed into the main body 11, and through the microstructure unit, the incident light is mixed more uniformly at the light incident surface 13. The microstructure units may also be a plurality of concave strips recessed into the main body 11, or convex particles or convex strips protruding from the main body 11. The concave or convex particles are uniformly distributed on the flap surface 131. Preferably, the depth of the concave particles recessed into the body 11 varies with the distance of the concave particles from the axis of the body 11, in particular, the depth of the concave particles recessed into the body 11 increases with decreasing distance of the concave particles from the axis of the body 11, i.e., the depth of the concave particles closer to the axis of the body 11 is deeper, in such a way that the concavity into the body 11 is more pronounced. In the case where the microstructure elements are convex particles, the height of the convex particles protruding from the main body 11 varies with the distance of the convex particles from the axis of the main body 11, and specifically, the height of the convex particles protruding from the main body 11 decreases with the distance of the convex particles from the axis of the main body 11, that is, the height of the convex particles closer to the axis of the main body 11 is smaller, and in this way, the concavity toward the main body 11 is more pronounced, as well.

When the microstructure unit is a plurality of concave strips recessed into the main body 11, the width of each concave strip in the lobe surface 131 varies with the distance of the concave strip from the axis of the main body 11, specifically, the width of each concave strip in the lobe surface 131 decreases with the distance of the concave strip from the axis of the main body 11, that is, the closer to the axis of the main body 11, the smaller the width of the concave strip, further, the depth of each concave strip recessed into the main body 11 varies with the distance of the concave strip from the axis of the main body 11, and specifically, the depth of each concave strip recessed into the main body 11 increases with the distance of the concave strip from the axis of the main body 11, that is, the closer to the axis of the main body 11, the deeper the depth of the concave strip.

When the microstructure unit is a plurality of convex strips protruding from the main body 11, the width of each convex strip in the flap surface 131 varies with the distance of the convex strip from the axis of the main body 11, specifically, the width of each convex strip in the flap surface 131 decreases with the decrease of the distance of the convex strip from the axis of the main body 11, that is, the width of the convex strip decreases closer to the axis of the main body 11, further, the height of each convex strip protruding from the main body 11 varies with the distance of the convex strip from the axis of the main body 11, specifically, the height of each convex strip protruding from the main body 11 decreases with the decrease of the distance of the convex strip from the axis of the main body 11, that is, the height of the convex strip decreases closer to the axis of the main body 11.

The optical path of a light guide according to an embodiment of the present invention is described below with reference to fig. 5, in which fig. 5 shows a light source 21, the light source 21 being, for example, a light emitting diode or a halogen lamp, which may be a point light source or a surface light source. The light beam emitted by the light source 21 is first incident on the concave surface of the light incident surface 13, refracted at the concave surface, and enters the main body 11 of the light guide 100, the light beam is totally reflected within the main body 11 of the light guide 100, and when the light beam is incident on the optical tooth 12, the light beam is reflected by the cross section of the optical tooth 12 and partially exits from the light exit side 14, thereby forming the light path 31. It can be seen here that, in contrast to the light path 31' shown by the dashed line which enters the light guide via the conventional planar entry face, the light path 31 continues to propagate in the light guide also deflected in the circumferential direction due to the concave entry face 13, i.e. the light rays entering the light guide are given a circumferential component via the concave entry face according to the present application.

Fig. 6, 7, and 8 show three different types of structures of the light incident surface. As shown in fig. 6, the light incident surface forms a concave surface recessed toward the inside of the main body and includes a plurality of flap surfaces 131 and a bottom surface 132, adjacent sides of the adjacent flap surfaces 131 are connected, and one end of all the flap surfaces 131 close to the main body is connected to the bottom surface 132. All the flap surfaces 131 may have the same shape, or alternatively, the flap surfaces 131 may have different shapes, for example, including 14 flap surfaces 131 divided into two sizes of flap surfaces 131, 7 flap surfaces 131 each, larger flap surfaces 131 and smaller flap surfaces 131 alternately. Here, the bottom surface 132 is configured to be circular, and the contour of the light incident surface on the light incident side of the light guide is circular. The incident surface formed by the flap surfaces 131 creates a helical effect as the flap surfaces 131 are twisted or skewed relative to the axis of the light guide.

Fig. 7 is another form of light incident surface, which differs from the structure shown in fig. 6 in that the bottom surface 132 is configured as a polygon, specifically a hexagon, the outline of the light incident surface on the light incident side of the light guide is also a polygon (hexagon), and all the flap surfaces 131 have the same shape, specifically a quadrangle, the shorter side of which is contiguous with one side of the bottom surface 132. The incident surface formed by the flap surfaces 131 creates a helical effect as the flap surfaces 131 are twisted or skewed relative to the axis of the light guide.

Fig. 8 shows a further form of light incident surface, which includes a plurality of recesses 135, the recesses 135 being regularly distributed at one end of the light guide, as shown, six recesses 135 are equiangularly distributed around one recess, the recesses 135 forming a microstructure unit.

Fig. 9 and 10 show a light emitting device according to an embodiment of the present invention, the light emitting device including a light source 21 and a light guide 100, wherein a surface of the light guide 100 on a side close to the light source 21 is an incident surface configured as a concave surface recessed inside a main body 11 of the light guide 100, and the incident surface forms a spiral shape in a direction from the incident surface to the main body 11 or in a main direction of light incidence, wherein the concave surface includes a plurality of flap surfaces 131, and only one flap surface is shown in fig. 9 and 10, as indicated by a dotted line.

Between the light source 21 and the light guide 100 collimating means may be arranged for collimating the light beam, which collimating means may improve the parallelism of the light beam entering the light guide 100, e.g. may collimate the light beam emitted by a point light source into an approximately parallel light beam. The collimating means in the embodiments of the present invention may employ a collimating means known in the art, such as a collimating lens.

The light emitting device according to embodiments of the present invention may include any type of motor vehicle illumination lamp and/or signal lamp, such as a head lamp, a center high mount stop lamp, a turn signal lamp, a position lamp, a tail stop lamp, a cabin lamp, and the like.

The light-emitting device has better optical performance, and the motor vehicle has better lighting effect.

Although the present invention has been described in connection with the accompanying drawings, the embodiments disclosed in the drawings are intended to be illustrative of preferred embodiments of the present invention and should not be construed as limiting the invention. The dimensional proportions in the figures are merely schematic and are not to be understood as limiting the invention.

Although a few embodiments of the present general inventive concept have been shown and described, it would be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the general inventive concept, the scope of which is defined in the claims and their equivalents.

Claims

1. A light guide (100) comprising:

a main body (11);

a light incident surface (13), the light incident surface (13) being provided on an end side of the main body (11); and

a light exit side (14), the light exit side (14) being located at a circumferential side of the body (11),

the method is characterized in that:

the light incident surface (13) is configured with a concave surface recessed towards the inside of the main body (11), the concave surface is formed by a generatrix (134) along the guidance of at least two closed guide lines (133), wherein, when viewed along the recessed direction, the outline of the foremost guide line (133) is smaller than the outline of the rearmost guide line (133), and the connecting line of the centers of the regions enclosed by the closed guide lines (133) is not in the same plane with the generatrix (134).

2. The light guide (100) of claim 1, wherein:

the guide line (133) is circular, regular polygon or formed by the combination of arc segments and straight lines.

3. The light guide (100) of claim 1, wherein:

The bus (134) is a straight line or a curved line.

4. The light guide (100) according to any one of claims 1 to 3, characterized in that:

the line connecting the centers of the cross-sections of the concavities is parallel to or coincides with the longitudinal axis of the body.

5. The light guide (100) according to any one of claims 1 to 3, characterized in that:

a plurality of concave surfaces are formed on the light incident surface (13).

6. The light guide (100) according to any one of claims 1 to 3, characterized in that:

the depth of the concave surface is less than twice the diameter of the body of the light guide.

7. The light guide (100) according to any one of claims 1 to 3, characterized in that: the body (11) of the light guide has a circular cross-section and the rearmost guide line (133) is a regular polygon inscribed in this cross-section.

8. A light emitting device, characterized in that: the light emitting arrangement comprises a light guide (100) according to any one of claims 1 to 7.

9. A motor vehicle characterized by: the motor vehicle comprising a light emitting arrangement according to claim 8.