Linear illumination device

Abstract

A linear illumination device is provided in which a transparent light guide made of glass is recessed in a profile opposite to a dark surface. A linear illumination device is also provided having a glass fiber bundle in a dyed tube.

Claims

1. A linear illumination device, comprising a side-emitting transparent light guide made of glass held in a profile with positive interlocking fit by outward facing projections on a mounting member, wherein the mounting member has wings laterally projecting beyond the light guide with the glass directly defining a light exit surface through which light can be seen.

2. The linear illumination device as claimed in claim 1, wherein the mounting member and the profile have complementary interlocking elements that secure the mounting member.

3. The linear illumination device as claimed in claim 1, wherein the mounting member is secured against rotation relative to the profile.

4. The linear illumination device as claimed in claim 1, further comprising an opening angle to a viewer that is limited by the mounting member, and wherein the opening angle is less than 90.

5. The linear illumination device as claimed in claim 1, wherein the side-emitting transparent light guide has a rear side that is dark has an L* value of less than 40 in the L*a*b* color space.

6. The linear illumination device as claimed in claim 1, wherein the profile is dark and has an L* value of less than 40 in the L*a*b* color space.

7. The linear illumination device as claimed in claim 1, wherein the side-emitting transparent light guide is set back relative to the profile by at least 0.5 mm.

8. The linear illumination device as claimed in claim 1, wherein the side-emitting transparent light guide is connected, via a flexible light guide, to an LED light source that is arranged at an angle relative to the side-emitting transparent light guide.

9. The linear illumination device as claimed in claim 8, wherein the flexible light guide and the LED light source are arranged in a cap attached to the profile.

10. The linear illumination device as claimed in claim 1, wherein the mounting member surrounds the side-emitting transparent light guide by at least 270.

11. A linear illumination device, comprising: a side-emitting transparent light guide made of glass and having a light exit surface; a profile having a light exit opening and mounting recesses on an inner surface; and a mounting member enclosing the side-emitting transparent light guide with at least the light exit surface visible through the light exit opening of the profile and with the glass directly defining the light exit surface through which the light can be seen through light exit opening, the mounting member having form-fitting elements on an outer surface that are seated in the recesses of the profile with the side-emitting light guide set back relative to the profile so that the side-emitting light guide is protected from damage, wherein the mounting member further comprises wings protruding beyond the side-emitting light guide to further protect the side-emitting light guide from damage.

12. The linear illumination device as claimed in claim 11, wherein the mounting member surrounds the side-emitting transparent light guide by at least 270.

13. The linear illumination device as claimed in claim 11, wherein the mounting member is secured against rotation relative to the profile by the form fitting elements.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The subject matter of the invention will now be explained in more detail with reference to the drawings.

(2) FIG. 1 shows a sectional view of a first embodiment of a linear illumination device according to the invention;

(3) FIG. 2 is a perspective view of an exemplary embodiment;

(4) FIG. 3 is intended to illustrate and explain in more detail the embodiment with a transparent light guide made of glass;

(5) FIG. 4 is intended to illustrate and explain in more detail the injection of light into the transparent light guide made of glass;

(6) FIG. 5 shows an alternative embodiment of light injection; and

(7) FIG. 6 is intended to illustrate and explain the alternative embodiment of the invention which uses a flexible glass fiber cable.

(8) FIG. 7 schematically illustrates how an LED light source is directly coupled to a light guide made of glass.

(9) FIG. 8 is a schematic view of a vehicle door provided with a covering in which a side-emitting glass fiber cable is installed.

DETAILED DESCRIPTION

(10) FIG. 1 shows a sectional view of a first embodiment of a linear illumination device 1 according to the invention.

(11) In this exemplary embodiment, linear illumination device 1 is configured as a footboard and comprises a profile 2, which may in particular be made of aluminum. Profile 2 is a hollow chamber profile.

(12) Recessed in the profile 2 are, inter alia, plastic anti-slip strips 4 which serve as a kick protection reducing the risk of scratching the adjacent profile 2.

(13) In order to provide a linear illumination device, a light guide 5 made of glass is inserted in an appropriate recess of the profile 2 at one side of profile 2 with positive interlocking fit, i.e. form-fitting engagement, by means of a mounting member 3. The light guide may for example be inserted by a sliding movement from one end.

(14) In the present exemplary embodiment, the glass light guide 5 comprises a colored glass core 6, in particular made of white glass. Due to the colored glass core 6, light is emitted sidewards, through opening 25.

(15) Mounting member 3 is provided in form of a plastic profile and has interlocking, i.e. form-fitting elements 8 seated in complementary recesses 7 of profile 2.

(16) Light guide 5 made of glass is set back relative to the adjacent profile 2, so that it is protected from damage.

(17) Otherwise, the light guide 5 made of glass directly defines the light exit surface through which the light can be seen through opening 25.

(18) Furthermore, the mounting member 3 additionally has wings 9 protruding beyond the glass light guide 5 thereby additionally protecting the latter from damage.

(19) The mounting member 3 which encloses the light guide 5 by at least 270 is limiting the opening angle of the linear illumination device towards a viewer. The opening angle is less than 90.

(20) In this exemplary embodiment, the mounting member 3 in the form of a plastic profile is black.

(21) In unlit condition, due to the transparent configuration of light guide 5, a viewer will see the black mounting member 3 behind, so that light guide 5 is almost invisible in daylight.

(22) Rather, the linear illumination device will resemble an embedded plastic anti-slip strip 4.

(23) It will be understood that in this embodiment of the invention which relates to a footboard, the light guide 5 is arranged at a lateral side in its installed state, since otherwise dirt could accumulate in the cone defined by mounting member 3.

(24) For an installation on the upper side it is conceivable to close the cone defined by opening 25 by a transparent plastic element (not illustrated).

(25) FIG. 2 is a perspective view illustrating a linear illumination device 1 which is also designed as a footboard.

(26) Metal profile 2 can be seen, in which anti-slip strips 4 are embedded.

(27) Light guide 5 which is accommodated in profile 2 in form-fitting engagement by means of mounting member 3 is coupled with an LED light source 13 via a flexible light guide 10.

(28) For this purpose, flexible light guide 10 is terminated at each of its ends by a ferrule 11, 12. In this manner, a plug-in connection can be provided, for example.

(29) LED light source 13 is preferably made to be water-tight. The LED light source 13 is powered via cables 14.

(30) Since the LED light source 13 can be installed at an angle, light guide 5 may be arranged close to the end face of profile 2.

(31) In the assembled state, profile 2 is closed by cap 15. In this case, LED light source 13 and flexible light guide 10 for connecting the latter will be arranged in cap 15. Therefore, only light guide 5 can be seen.

(32) This embodiment variation of the invention allows for a very simple and yet robust and weatherproof design of a footboard with contour illumination which is almost invisible in unlit condition.

(33) FIG. 3 schematically illustrates the light guide 5 made of glass which is employed.

(34) It includes a colored glass core 6, in particular of white glass.

(35) Furthermore, light guide 5 comprises a cladding material 16 which has a lower refractive index than the core glass, so that total internal reflection is obtained in this way.

(36) Due to the colored glass core 6 light is emitted sidewards, since the colored glass core 6 acts as a scattering center.

(37) Referring to FIG. 4, the injection of light into light guide 5 made of glass will be explained schematically.

(38) A glass fiber bundle 17 is employed as the flexible light guide, which is usually disposed in a tube (not illustrated).

(39) For terminating the fiber bundle 17, the tube is removed at the end of the bundle, and the individual glass fibers of the glass fiber bundle 17 are inserted into ferrule 18, which previously has been filled with a transparent optical adhesive.

(40) A pin 19 protrudes from the base 20 of the ferrule opposite to the colored glass core 6 to displace the individual glass fibers in the area of colored glass core 6 when the glass fiber bundle is inserted, so that little or no light is directly injected into colored glass core 6.

(41) In this way, inhomogeneous radiation in the end region is avoided.

(42) It will be understood that further coupling elements for coupling ferrule 18 and light guide 5 are not shown in this schematic drawing. This relates in particular to form-fitting or clamping elements.

(43) FIG. 5 shows an alternative embodiment in which the light guide 5 made of glass and including the colored glass core 6 is chamfered at the end. Light from LED light source 13 is irradiated into the light guide 5 from a lateral side thereof and is deflected by total internal reflection at face 21 to propagate along light guide 5.

(44) This embodiment variation allows for an even more compact design as compared to the embodiment variation illustrated in FIG. 2, but usually will be associated with higher light loss and less homogeneous illumination in the end region.

(45) FIG. 6 schematically illustrates an alternative embodiment of the invention, in which a flexible glass fiber cable 22 is employed for emitting light sidewards.

(46) Glass fiber cable 22 is coupled to an LED light source (not shown) via a ferrule 24.

(47) The tube 23 of the glass fiber bundle is dyed.

(48) In one embodiment of the invention, tube 23 is dyed black and therefore appears black in unlit condition so that it is almost indistinguishable from adjacent components.

(49) However, a different coloring which has approximately the same color as an adjacent receptacle, in particular an adjacent covering part, is likewise conceivable.

(50) FIG. 7 schematically illustrates how an LED light source can even be directly coupled to the end of a light guide 5 made of glass.

(51) In this exemplary embodiment, light guide 5 made of glass comprises a glass rod including a colored glass core 6 (corresponding to the embodiments of FIG. 1 and FIG. 2).

(52) As a difference to the embodiment illustrated in FIG. 1 and FIG. 2, in this exemplary embodiment an LED light 28 is directly placed on the end of light guide 5.

(53) LED light 28 comprises a housing 29.

(54) A printed circuit board 30 with an LED_31 is disposed within housing 29, in the present exemplary embodiment in the form of a thin film LED.

(55) Opposite colored glass core 6 the housing 29 has a masking 32 shadowing colored glass core 6.

(56) This contributes to reduce inhomogeneities near the position of light injection.

(57) Masking 32 may, for example, comprise a dark stained area in an otherwise transparent housing base. In the case of a housing that opens downwardly (not shown), the masking may as well be provided as a cover connected with the side walls of the housing by webs.

(58) FIG. 8 is a schematic view of a vehicle door 26 in which a side-emitting glass fiber cable 22 is installed as an ambient lighting.

(59) For this purpose vehicle door 26 comprises a covering 27 on its inner side, for example of a plastic material. Covering 27 has a groove formed therein, which predetermines the contour of the ambient lighting.

(60) Glass fiber cable 22 is clamped or glued into this groove.

(61) In one embodiment, a glass fiber cable 22 is used which has a dark colored tube. Preferably in this embodiment of the invention, the adjacent covering 27 is also black or dark gray.

(62) So in unlit condition the glass fiber cable 22 will be hardly visible, whereas in the dark a highly visible and visually pleasing ambient lighting is provided.

(63) When an achromatically dyed tube is used, it is in particular also possible to use an RGB light source. This moreover allows to modify the light color of the ambient lighting.

(64) In another embodiment of the invention, the tube is dyed colorful. Preferably in this embodiment of the invention, the adjacent covering 27 is also provided in approximately the same color corresponding to the tube.

(65) It has been found that for this embodiment of the invention an LED light source is preferred whose color matches the color of the tube, in particular an LED light source having only a single emission peak, i.e. a light source which preferably emits light in a narrow spectral range.

(66) In this way it is possible to provide an ambient lighting with a homogenous color impression even with a colorful dyed tube.

(67) At all embodiments, the backside of the tube, accordingly the side of the clamped or glued tube of the glass fiber cable 22 adverted to the viewer, can be embodied as a reflection surface. This can be achieved with a coextruded reflective material, with a paint or with an inserted strip of a reflective material, in particular with a metal foil.

(68) For this embodiment of the invention, the tube is preferably not exactly circular in order to facilitate an oriented insertion of the glass fiber cable in the groove. In particular, the tube can comprise projections which axially extend outside and which prevent twisting of the tube.

(69) The invention permits to provide sharply contoured linear illumination devices which are robust and weatherproof and at the same time hardly detectable in unlit condition.

(70) TABLE-US-00001 LIST OF REFERENCE NUMERALS 1 Linear illumination device 17 Glass fiber bundle 2 Profile 18 Ferrule 3 Mounting member 19 Pin 4 Anti-slip strip 20 Base 5 Light guide made of glass 21 Face 6 Colored glass core 22 Glass fiber cable 7 Recess 23 Tube 8 Interlocking element 24 Ferrule 9 Wing 25 Opening 10 Flexible light guide 26 Vehicle door 11 Ferrule 27 Covering 12 Ferrule 28 LED light 13 LED light source 29 Housing 14 Cable 30 PCB 15 Cap 31 LED 16 Cladding material 32 Masking