Light guide device

Abstract

The invention relates to an optical waveguide arrangement, comprising an optical waveguide (2) having at least two separate input conductor sections (3, 4) which are arranged at the ends and which have a cross-section which is at least partially defined and which comprises an edge section having a first radius (R1), the input conductor sections (3, 4) converge and gradually merge on a merging section (6) to form a common main conductor section (5) having an at least partially given cross-section, which cross-section comprises an edge section having a second radius (R2), such that light introduced in each case into the input conductor sections (3, 4) is guided into the common main conductor section (5), the merging section (6) extends over a length corresponding to 10-50 times the first radius (R1).

Description

Technical Field

[0001] The invention relates to a light conductor device. Background Art

[0002] Optical conductor devices are used, for example, in automotive lighting. Optical conductor devices can be used to couple light into an optical conductor device or its optical conductor at one location and couple it out again at another remote location. For coupling in, a light source module connected to the optical conductor is used, and light is coupled in through the light source module on the end side of the optical conductor. Sometimes, the amount of light from the available light source module is not enough to provide the amount of light required at the other end of the optical conductor. For this purpose, such an optical conductor device is known, that is, it has an optical conductor, and the optical conductor has two or more independent input conductor sections, which are merged into a common main conductor section. An example of this can be found in DE 199 39 087A1. An independent light source is provided for each conductor section, so that a correspondingly high amount of light can be coupled in, and a correspondingly high amount of light is coupled out at the other end. It can be achieved by this that a sufficient amount of light signal can be given at the coupling-out location, despite a correspondingly high ambient brightness, for example, when there are one or more additional light-emitting indicator lights that are simultaneously operated in the environment. Nevertheless, there is a need to reduce the light transmission losses so that either a higher amount of light can be coupled out or the conductor length can be increased. Summary of the invention

[0003] The object of the present invention is therefore to specify an improved light guide arrangement.

[0004] In order to solve this problem, according to the present invention, an optical conductor device is provided, which includes an optical conductor, the optical conductor having at least two independent input conductor sections arranged at the ends, the input conductor sections having an at least partially given cross-section, the cross-section including an edge section with a first radius (R1), the input conductor sections converge and gradually merge into a common main conductor section on a merging section, the main conductor section having an at least partially given cross-section, the cross-section including an edge section with a second radius (R2), so that light introduced into the input conductor sections respectively is guided into the common main conductor section, wherein the merging section extends over a length corresponding to 10-50 times the first radius.

[0005] In the optical waveguide device according to the invention, at least two input conductor segments are provided, which have a cross-sectional shape which in any case has an edge segment which forms a section of the outer circumference, the edge segment being curved, i.e. the edge segment can be defined by a radius. For example, a circular, cylindrical cross-sectional shape can be provided which has a uniform radius around the circumference, or a D-shaped cross-sectional shape can be provided which has an edge segment with a diameter around, for example, approximately 180°. The two input conductor segments converge into a common main conductor segment, i.e. the input conductor segments gradually merge over a merging section until the two input conductor segments merge into a unified main conductor segment, the main conductor segment also having a cross-sectional shape which at least partially includes an edge segment with a second radius, i.e. the edge segment also forms a circular boundary at least over a portion of its circumference, wherein the segment can also be defined by a radius. Preferably, the second cross-sectional shape is circular, i.e. the main conductor segment is cylindrical, but it can also differ from a cylindrical shape. The length of the merging section is important for the invention. According to the present invention, the length of the merging section corresponds to 15-50 times the first radius. That is, the length measured from the first contact position of the two input conductor segments to the position where they are completely merged into a main conductor segment with a second radius corresponds to a multiple of the first radius, that is, at least 10 times and at most 50 times the first radius. This is based on the understanding that when the merging section is too short, the angle between the interfaces participating in the light reflection is too large. Because the two input conductor segments are at a relatively large angle to each other and are merged into a main conductor segment that must also extend to the input conductor segment at a corresponding angle through a very short merging section, wherein the angle between the main conductor segment and each individual input conductor segment is almost corresponding to half of the angle between the two input conductor segments extending into each other. Therefore, the interface does not extend in parallel, so that the angle of incidence relative to the vertical line on the interface changes and increases. If the angle of the light beam incident on the interface exceeds the limit angle of total reflection, the total reflection can no longer be maintained, and the light beam is coupled out of the optical conductor into the environment. As a loss, the amount of light coupled out is no longer available. However, as provided by the invention, if a correspondingly long merging section is implemented, a corresponding angular situation can be formed, namely, in this case, the relevant interface, i.e., the side surfaces of the input conductor section and the main conductor section, extend toward each other at an angle that ensures total reflection as much as possible, so that undesired light outcoupling in the transition area between the input conductor section and the main conductor section is significantly reduced. As a result, the amount of light coupled out at the end of the main conductor section can be increased. Although the amount of light coupled out is usually slightly less than the amount of light coupled in, since there are always certain losses over the length of the optical conductor, these losses can be significantly reduced because the transition area, i.e., the area of ​​the merging section, as a possible loss site is "eliminated" due to the geometry according to the invention.This in turn provides the possibility of coupling out more light with the same amount of light coupled out at the end point of the main conductor section compared to an optical waveguide not designed according to the invention, or of correspondingly extending the main conductor section in order to be able to couple out the same amount of light at the end point of the main conductor section, as in the case of an optical waveguide not designed according to the invention but which has a shorter main conductor section.

[0006] According to the present invention, it has been shown to be sufficient to limit the length of the merged section to at least 10 times and at most 50 times the first radius. A merged section length corresponding to at least 10 times the first radius ensures that a corresponding angular geometry that guarantees total reflection can be maintained as much as possible is given. From a merged section length of 50 times or more, no improvement occurs. It is conceivable that the length interval is precisely limited to at least 20 times the first diameter and at most 50 times the first radius, and also only at most 40 times if necessary.

[0007] According to a generalized inventive design, before the merging section, each input conductor section can transition from a cylindrical cross-sectional shape to a drop-shaped cross-sectional shape, and the input conductor section has the drop-shaped cross-sectional shape at least at the beginning of the merging section, wherein the input conductor section gradually merges with the drop-shaped cross-sectional shape. The two input conductor sections have a circular cross-sectional shape at their free ends, which has a first diameter. Just before the merging section is about to begin, the input conductor section maintains this geometric shape. Subsequently, the geometric shape changes into a drop-shaped shape, that is, the geometry has a partially circular section like the original, that is, an edge section with a first radius, but is tightened according to the form of a drop. Now, the two input conductor sections merge through the drop-shaped cross-sectional shape, that is, the input conductor sections contact each other at the beginning of the merging section and merge more and more through the drop shape over the length of the merging section, until at the end of the merging section, there is only a preferably circular cross-sectional shape with a second radius, that is, the main conductor section.

[0008] Here, according to an advantageous improvement, in a specific implementation, the drop-shaped cross-sectional shape of the input conductor segment has an edge segment extending over a range of at least 180°, which transitions on both sides into a flat edge surface, which leads into a tip, wherein the input conductor segment converges with the tip and forms a connecting bridge / connecting transition that becomes wider and wider over the merging section. That is, the two drop shapes approach each other and touch each other via their tips and further merge over the length of the merging section, wherein the two partially circular edge segments form the main outer boundaries over the merging section. Therefore, at the beginning of the merging section, a very narrow connecting bridge is first formed by the converging tip segments, which becomes wider and wider over the length of the merging section, wherein the diagonally opposite, partially circular boundaries now approach each other further, until at the end of the merging section, there is only a common, circular conductor boundary that defines the main conductor segment.

[0009] Alternatively, other cross-sectional geometries are also conceivable. For example, it can be provided that before the merging section, each input conductor segment transitions from a cylindrical cross-sectional shape to a D-shaped cross-sectional shape, and the input conductor segment has this D-shaped cross-sectional shape at least at the beginning of the merging section, wherein the input conductor segments gradually merge with the D-shaped cross-sectional shape. That is, here, each input conductor segment, for example, starts with a circular cross-sectional shape and has a D-shaped cross-sectional shape before the merging section, wherein the two D-shaped input conductor segments are pushed into each other to a certain extent and merge into each other on the merging section due to the D-shaped cross section.

[0010] Here, the D-shaped cross-sectional shape of the input conductor segment can each have an edge segment extending over a range of at least 180°, which edge segment either transitions to a flat edge surface on both sides, adjacent to which is a base surface extending orthogonally to the edge surface, wherein the two input conductor segments enter each other via two edge surfaces extending parallel to each other, or wherein the edge segment directly adjoins the base surface, wherein the two input conductor segments enter each other with their two base surfaces extending parallel to each other by parallel displacement. That is, the D cross-section is different. Although this variant is described as "D" as shown, in another variant, the cross-sectional shape is more lens-shaped. Independently of this, the two shapes are pushed into each other to a certain extent by linear displacement.

[0011] According to a particularly advantageous embodiment, the first radius and the second radius are identical. That is to say, for example, in the case of a circular cross section with a first diameter of 4 mm, at the entry of the two input conductor segments (i.e., where the light is coupled into the end face by the corresponding light source module), the main conductor segment, which is preferably also circular in cross section, has a diameter of 4 mm, more precisely, already immediately at the end of the merging section. Of course, the first and second radii can also have larger or smaller values, for example 3 mm or 5 mm, 6 mm, 7 mm, 8 mm, 9 mm or 10 mm, wherein this list is also not exhaustive. However, regardless of the actual first diameter, the merging section is always at least 10 times and at most 50 times the first radius of the radius segment.

[0012] Preferably, the optical waveguide is made of plastic, in particular polymethyl methacrylate (PMMA), polycarbonate (PC) or polystyrene (PS). The production of the optical waveguide from plastic, such as preferably PMMA, PC or PS, allows the construction of the Y-geometry according to the invention with two input conductor sections, a long merging section, which is designed in particular according to a drop-shaped cross-sectional shape, and a main conductor section using suitable tools. Embodiments made of glass are also conceivable.

[0013] In addition, the optical waveguide device preferably includes an adjacent light source module on each input conductor segment, which is fixedly connected to the input conductor segment. The light source module has a corresponding receiving segment, into which the free end of the corresponding input conductor segment is inserted, and a defined interface with the actual light source is constructed in the receiving segment, so that the best possible light coupling can be achieved. Preferably, each light source module can have one or more LEDs as light sources. Here, the light source module can only be one or more multi-color LEDs (for example, white, ice blue) or single-color LEDs (for example, red, yellow, amber, blue). Alternatively, RGB-LEDs, i.e., at least three LEDs, which emit light of red-green-blue light colors, can also be provided, wherein light mixing can be achieved by RGB-LEDs, and various arbitrary light colors can be generated. It is also conceivable to mix multiple different types of LEDs.

[0014] At the ends of the two input conductor segments connected to the light source module, the input conductor segments can be circular in cross section, but also have other cross-sectional shapes. The cross-sectional shape can be, for example, an ellipse, or a triangle or a polygon, and other shapes, such as a star or cloud, are also conceivable. In order to improve light mixing, the geometric shape can also be distorted. However, in the transition to the connecting section, the input conductor segment preferably has a circular cross-sectional shape, which then transitions, for example, into a drop shape or a D shape, and then a fusion is achieved through this shape.

[0015] The invention further relates to a motor vehicle comprising at least one optical waveguide arrangement of the type described above. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Further advantages and details of the invention are apparent from the following exemplary embodiments and from the accompanying drawings. The drawings show:

[0017] Figure 1 The optical waveguide arrangement according to the invention is shown by five cross-sectional views in different planes.

[0018] Figure 2-Figure 7 shows a cross-sectional view of a merged input conductor section, which begins directly at the start of the merged section and ends at the end of the merged section,

[0019] Figure 8 shows a cross-sectional view of two input conductor sections having a first D-shape, and

[0020] Fig. 9 A cross-sectional view of two input conductor sections having a second D-shape is shown. DETAILED DESCRIPTION

[0021] Figure 1 The optical waveguide device 1 according to the invention is shown, which comprises an optical waveguide 2, which has a main conductor section 5 and two input conductor sections 3, 4. The two input conductor sections 3, 4 are merged into the main conductor section 5 at a merging section 6, which is described in detail below. In addition, two light source modules 7 are provided, which are connected to the free ends of the two input conductor sections 3, 4. Each light source module 7 has at least one light source 8, which is only shown symbolically here. Preferably, the light source is one or more LEDs, which either emit monochromatic or polychromatic light, or are designed as an RGB array. Through each light source module 7, a defined amount of light can be coupled into each input conductor section 3, 4, wherein the light is further guided in the input conductor sections 3, 4 by total reflection and reaches the main conductor section 5 through the merging section 6, and the light is coupled out at the end of the main conductor section.

[0022] Each input conductor segment has a circular cross-sectional shape with a first diameter D1 defined by a first radius R1. The main conductor segment 5 also has a circular cross-sectional shape with a second diameter D2 defined by a second radius R2. Preferably, D1=D2, or R1=R2, that is, the two input conductor segments 3, 4 merge with each other through the merging section 6 and ultimately form a main conductor segment 5 with the same diameter or the same radius.

[0023] It is important that the merging section 6 has a corresponding length corresponding to at least 5 times and at most 25 times the first diameter or corresponding to at least 10 times and at most 50 times the first radius. For example, if each input conductor section 3, 4 has a first diameter of 4 mm, the length of the input conductor section is between 20-100 mm. Figure 1 As shown, the two input conductor sections 3, 4 therefore run almost parallel to each other or at a very small angle to each other along the merging section 6, especially also in the area of ​​the subsequent transition into the main conductor section 5, which results in the interfaces participating in the total reflection, i.e. the side surfaces of the converging input conductor sections 3, 4 and the main conductor section 5, running almost parallel to each other. This ensures that the total reflection is almost completely maintained on the merging section 6 and in the transition to the main conductor section 5, and only very small decoupling losses occur in this area.

[0024] Six different cross-sectional views are shown below for the optical waveguide 2. Figure 1 The six different planes I, II, III, IV, V and VI shown in FIG. According to these cross-sectional views, the merging process on the merging section 6 can be seen.

[0025] The section I is still in the region where the two input conductor sections 3, 4 do not yet touch one another, ie directly before the beginning of the merging section 6. It can be seen that the two input conductor sections 3, 4 have a circular cross-sectional shape with a first diameter D1.

[0026] In the direction of the merging section 6, the two input conductor sections 3 and 4 are further approached toward each other. At this time, the cross-sectional shape of the input conductor sections 3 and 4 changes from a circular cross-sectional shape to a drop-shaped cross-sectional shape, as will be described below. Figure 2 The drop-shaped cross-sectional shape is characterized by an edge section 10 with a first radius R1 extending over a range of at least 180°, at which the circular cross-sectional shape is retained, but the edge section transitions on both sides into a flat edge surface 11, which then opens into a tip 12, as shown in FIG. Figure 2 This design is present in both input conductor sections 3, 4, wherein the two input conductor sections 3, 4 approach each other with their two tips 12 and touch each other at the beginning of the merging section 6. Subsequently, at the beginning of the merging section 6, the two input conductor sections 3, 4 merge, as shown in FIG. Figure 1 As shown in the cross-sectional view in plane II. Forming a connecting bridge 13, see Figure 2 , the connecting bridge is very narrow at the beginning.

[0027] The next cross-sectional view is in plane III. It can be seen that the fusion process is continuing. The connecting bridge 13 becomes wider and the two input conductor sections 3 , 4 or the circular edge sections 10 approach each other.

[0028] As shown in the cross-sectional view in plane IV, this fusion process is still continuing. It can be seen that the connecting bridge 13 is wider and the two edge sections 10 are closer to each other.

[0029] In plane V, the merging process has already progressed to a considerable extent. It can be seen that the two input conductor sections 3 , 4 merge almost completely into one another, with only small edge irregularities still remaining due to the initial drop-shaped geometry.

[0030] At the end of the merging section 6, the merging process is finally completely completed. The two input conductor sections 3, 4 are completely merged with each other and form a main conductor section 6, see the cross-sectional view in the plane VI, which has a circular cross-sectional shape with a second diameter D2, wherein it is preferably applicable that the two diameters are the same, that is, D1=D2. The main conductor section 5 therefore has a corresponding edge section with a second radius R2, wherein here, due to the circular cross-sectional shape, the edge section completely delimits the main conductor section 5.

[0031] With the described merging, of course, the amount of light conductor material also decreases, since, given the same radius, the cross-sectional area of ​​the two individual input conductor sections 3, 4 must be double the cross-sectional area of ​​the main conductor section 5, i.e., the amount of light conductor material in this region is therefore double that in the region of the main conductor section 5. This means that the structure consisting of the two individual conductor sections 3, 4 gradually connects and also tapers at the merging section 6, wherein this taper occurs in particular in the region where the two individual conductor sections 3, 4 are already connected to one another via a relatively wide connecting bridge 13. This is particularly true in the case of the two individual conductor sections 3, 4 which are connected to one another via the relatively wide connecting bridge 13. Figure 1 1 , in particular in the region of planes IV, V.

[0032] Figure 2-Figure 7 The fusion process and the resulting geometric changes are shown again in detail.

[0033] on the one hand, Figure 2 Two inlet conductor sections 3 , 4 are shown, which have their drop-shaped cross-sectional shape already described above. The two tips 12 touch each other immediately at the beginning of the merging section 6 .

[0034] Figure 3 The beginning of fusion is shown. A connecting bridge 13 is formed. As shown by arrow P1, a certain degree of movement occurs, which progresses as the fusion increases, see Figure 4 .

[0035] exist Figure 5 In FIG. 1 , the two supply conductor sections 3 , 4 have already merged into one another to a considerable extent, the actual drop shape has dissolved, and there is no longer a flat edge surface 11 . Only the top and bottom sides still have a slightly corrugated or concave structure.

[0036] The two feed conductor sections 3, 4 are then pushed into one another, only to a certain extent with increasingly smoothed sides, as in Figure 6 As shown by arrow P2, until the Figure 7 The final cross-sectional shape of the main conductor section 6 shown in FIG. 6 has a diameter D2 .

[0037] exist Figure 2-Figure 6 In the figure, for illustration purposes, the two input conductor sections 3 and 4 are shown in different ways, the input conductor section 3 is shown with hatching and the input conductor section 4 is not hatched. Figure 5 and Figure 6 In the example, cross sections of different sizes are chosen to appear in the merging state only for illustration reasons. However, preferably, the two input conductors 3, 4 merge gradually and evenly in the merging section 6. Figure 7 The main conductor section 5 in FIG. 1 is again shown in a hatched manner to indicate that it is the result of a fusion of the two input conductor sections 3 , 4 .

[0038] Figure 8 and Fig. 9 Two different D-shaped cross-sectional shapes are shown for the input conductor sections 3, 4. Before the merging section 6, each input conductor section 3, 4 transitions from a cylindrical cross-sectional shape to a D-shaped cross-sectional shape, which the input conductor sections have at least at the beginning of the merging section 6, wherein the input conductor sections 3, 4 gradually merge with the D-shaped cross-sectional shape.

[0039] exist Figure 8 , a D-shape is shown, each with an edge section 10, which extends approximately 180° and then transitions on both sides into a flat edge surface 11, which is adjoined by a base surface 14. The two edge sections 10 again have a first radius R1. The two input conductor sections 3, 4 converge via two adjacent edge surfaces and are “pushed into each other” to a certain extent, thus ultimately forming a main conductor section 5, which is again circular in cross section, for example, and has a second radius, which again preferably corresponds to the first radius R1.

[0040] In accordance with Fig. 9In the embodiment of , approximately lens-shaped cross sections of the input conductor sections 3, 4 are provided, which likewise each have an edge section 10 extending around approximately 180°, but which here directly adjoins the base surface 14. The merging takes place by parallel displacement of the two base surfaces 14 until a main conductor section is formed which is circular in cross section and has a second radius R2.

Claims

1. An optical conductor arrangement, comprising an optical conductor (2), the optical conductor having at least two independent input conductor sections (3, 4) arranged at the ends, the input conductor sections having an at least partially given cross section, the cross section comprising an edge section having a first radius (R1), the input conductor sections converging and merging gradually at a merging section (6) into a common main conductor section (5), the main conductor section having an at least partially given cross section, the cross section comprising an edge section having a second radius (R2), so that light introduced into the input conductor sections (3, 4) is guided into the common main conductor section (5), wherein: The merging section (6) extends over a length corresponding to 10-50 times the first radius (R1).

2. The light conductor device according to claim 1, It is characterized in that Before the merging section, each input conductor section (3, 4) transitions from a cylindrical cross-sectional shape to a drop-shaped cross-sectional shape, and the input conductor section has the drop-shaped cross-sectional shape at least at the beginning of the merging section (6), wherein the input conductor sections (3, 4) gradually merge with the drop-shaped cross-sectional shape.

3. The light conductor device according to claim 2, It is characterized in that The drop-shaped cross-sectional shape of the input conductor sections (3, 4) each has an edge section (10) extending over a range of at least 180°, which transitions on both sides into a flat edge surface (11) which opens into a tip (12), wherein the input conductor sections (3, 4) converge at the tip (12) and form a connecting bridge (13) that widens gradually at the merging section (6).

4. The light conductor device according to claim 1, It is characterized in that Before a merging section (6), each input conductor section (3, 4) transitions from a cylindrical cross-sectional shape to a D-shaped cross-sectional shape, the input conductor section having the D-shaped cross-sectional shape at least at the beginning of the merging section (6), wherein the input conductor sections (3, 4) are gradually merged with the D-shaped cross-sectional shape.

5. The light conductor device according to claim 4, It is characterized in that The D-shaped cross-sectional shape of the input conductor sections (3, 4) each has an edge section (10) extending over a range of at least 180°. The edge section transitions on both sides into a flat edge surface (11), adjacent to which is a base surface (14) extending orthogonally thereto, wherein the two input conductor sections (3, 4) penetrate into one another via two edge surfaces (11) extending parallel to one another. Or wherein the edge section (10) directly adjoins the base surface (14), wherein the two feed conductor sections (3, 4) with their two base surfaces (14) extending parallel to one another enter into one another by parallel displacement.

6. The light conductor arrangement according to claim 1, It is characterized in that The first radius (R1) and the second radius (R2) are the same.

7. The optical waveguide device according to claim 1, It is characterized in that The light guide (2) is made of plastic, in particular PMMA, PC or PS, or of glass.

8. The optical waveguide device according to claim 1, It is characterized in that Each input conductor section (3, 4) is adjacent to a light source module (7), which is fixedly connected to the input conductor section (3, 4).

9. The light conductor device according to claim 8, It is characterized in that Each light source module (7) has one or more LEDs as light sources (8).

10. A motor vehicle comprising at least one optical waveguide arrangement (1) according to any one of the preceding claims.

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