Two-wheeler headlight and method for mounting the same

Abstract

A two-wheeled headlight, in particular for a bicycle or an e-bike, comprising a housing (2) having a light exit (3) in which at least one laser diode (5) is arranged, which emits laser light (7) onto a converter (6) by means of which the wavelength of the laser light (7) can be converted, and comprising a light optics (10) for guiding the converted laser light (11) out of the light exit (3) of the housing (2), characterized in that a safety device (12) is provided which is designed in such a way that escape of unconverted laser light (7) from the light exit (3) is prevented, and in that the safety device (12) comprises a safety shading device (13).

Description

The invention relates to a two-wheeler headlight, in particular for a bicycle or an e-bike, having a housing having a light outlet, in which at least one laser diode is arranged, which emits laser light onto a converter, by means of which the wavelength of the laser light can be converted, and having a light optics for guiding the converted laser light out of the light outlet of the housing. The invention further relates to a method for mounting a two-wheeler headlight.Headlights of this type are already known from the prior art, for example DE 10 2014 111 321 A1 from the applicant shows a corresponding headlight in which a converter is irradiated with laser light in order to convert the laser light of the laser diode and thereby to increase the wavelength range of the monochromatic laser light and ideally to generate white light. In the headlight known from the prior art, the converter is arranged in the region of the light optics, so that in unfavourable conditions-for example in the event of damage to the converter-it may possibly occur that unconverted laser light can emerge from the light outlet, which would entail a high risk of glare and the risk of damage to the health of non-involved third parties by the emerging laser light.DE 10 2014 118 403 A1 discloses a motor vehicle headlight having a laser light source, the light of which is emitted onto a converter. In order to prevent laser light from being emitted into the environment in the event of an accident or a defect, the laser light is emitted counter to the main propagation direction of the motor vehicle headlight.The part of the invention relating to the two-wheeler headlight is therefore based on the object of reducing the disadvantages mentioned above. The method is based on the object of providing an assembly method for a two-wheeler headlight according to the invention.The part of the object relating to the two-wheeler headlight is achieved according to the invention in a two-wheeler headlight of the type mentioned at the beginning in that a safety device is provided which is designed in such a way that an escape of unconverted laser light from the headlight is prevented, and in that the safety device comprises a safety shading.The safety device thus ensures that even in the event of a fault or damage to the converter or other components of the two-wheeler headlight, the unconverted laser light is prevented from emerging from the headlight. The shading, which is impenetrable for the laser light emitted from the laser diode and preferably absorbs it, ensures that the laser light cannot emerge from the two-wheeler headlight even if a defect should occur within the two-wheeler headlight.In this context, it has also proven useful if the safety shading is formed as a plastic wall. This can be produced cost-effectively and transmission of the laser light emitted by the laser diode through the plastic wall can be prevented by a suitable choice of material. In addition, the plastic wall can absorb the laser light and thereby avoid reflections.It also has a positive effect on the production costs and the assembly effort if the safety shading is integrated into the housing. This makes it possible to dispense with the separate production of shading. The housing can also be formed in multiple parts and comprise a front part and a rear part, which at the same time serve as shading.It has also proven to be particularly advantageous if the securing device comprises a bore formed in the light optics. This ensures that the laser light emitted by the laser diode cannot strike the light optics even if the converter is damaged and becomes transmissive for the unconverted laser light. In this case, the laser light is guided through the converter onto the bore formed in the light optics and can then be prevented from leaving the two-wheeler headlight, for example by a safety shading. In addition, by suitably positioning the bore in the light optics, the unconverted laser light is prevented from impinging on the light optics. Rather, an unconverted laser beam strikes a shading through the bore and is absorbed there.It has also been found to be advantageous if the at least one laser diode and the converter are accommodated in a diode housing. This makes it possible to premount the laser diode and the converter in the diode housing and then couple the unit thus formed to the housing. In this context, it has also proven advantageous if a through opening is formed in the diode housing. This ensures that the laser light remains in the diode housing when the orientation of the laser diode is adjusted, and only the laser light converted by the converter can emerge from the passage opening of the diode housing and strike the light optics of the two-wheeler headlight.In order to effectively dissipate the heat generated during the generation and conversion of the laser light, it has been shown to be favorable if the diode housing is formed from metal. In particular, the use of aluminum as diode housing material is particularly suitable in this case in order--at low production costs and weight--to effectively dissipate the heat which occurs to the outside of the housing. The wind in motion can then effectively dissipate the heat generated.The assembly effort can be reduced if the diode housing is secured to the housing by a screw connection. Thus, a unit comprising the diode housing with the laser diode and the converter can be pre-assembled and then screwed to the housing, wherein it has proven particularly advantageous here if the screw connection is realized by a self-tapping plastic screw.It has also been found to be advantageous if the light outlet is welded to the housing. In this way, it can be ensured in particular that, after a correct positioning of the light optics, the manipulation thereof can be ruled out, since this is not accessible without forced opening of the light outlet.It has also proven advantageous if the converter is designed as a reflection converter or as a transmission converter. If the converter is designed as a transmission converter, a deflection mirror can be provided in particular, by means of which the laser light is deflected onto the converter. In a reflection converter, on the other hand, the light emitted by the laser diode is first directed onto the converter and then conducted back to the light optics through the reflective portion of the converter. Both converters can each realize a very compact design of the two-wheeler headlight.The part of the object relating to the method for assembling a bicycle headlight is achieved according to the invention in that it comprises the steps:- pre-mounting a unit comprising at least one laser diode, and a converter in a diode housing,connecting the diode housing to a housing, andinserting a light optic into the housing.This ensures that the laser diode is aligned optimally with respect to the converter and the unit thus pre-assembled in the diode housing can be connected to the housing of the two-wheeler headlight. Then, by inserting the light optics into the housing, the latter is also aligned optimally with respect to the converter in order to optimize the light emission of the converted laser light from the two-wheel headlight.It has also proven advantageous if the light optics is fixed to the housing by welding a light outlet. This ensures that the position of the light optics can be optimally adjusted, thereby reducing the risk of improper handling of the two-wheeler headlight according to the invention. In addition, this also ensures that the diode housing and the light optics are no longer accessible after the welding of the light exit to the housing, without forcibly removing the light exit.It has also proven advantageous if the diode housing is connected to the housing by a screw connection. This ensures that the diode housing and the housing are firmly connected to one another, as a result of which the laser light converted by the converter can strike the light optics as optimally as possible.The invention is explained in more detail below using two exemplary embodiments shown in the drawings; it shows: FIG. 1 shows a sectional view through a first embodiment of the two-wheeler headlight according to the invention with a reflection converter, FIG. 2 shows a sectional view through a second embodiment of the two-wheeler headlight according to the invention with a transmission converter and a deflection mirror, FIG. 3 is a sectional view through the embodiment according to FIG. 2 with a defective deflection mirror, and FIG. 4 shows a sectional view through the embodiment according to FIG. 2 with a defective transmission converter.FIG. 1 shows a first embodiment of the two-wheeler headlight 1 according to the invention with a housing 2 which has a light outlet 3. A diode housing 4 is arranged in the housing 2, in which a laser diode 5 oriented in the direction of travel and a converter 6 are accommodated. The monochromatic laser light 7 emitted by the laser diode 5 impinges on the converter 6, which in the exemplary embodiment shown is designed as a reflection converter 8. The laser light 7 is then converted into white light by the converter 6 and is guided through the reflective part of the reflection converter 8 out of the diode housing 4 through a passage opening 9 to a light optics 10, from which the converted laser light 11 exits from the housing 2 from a light outlet 3 and thus illuminates the roadway. In the exemplary embodiment shown in FIG. 1, a securing device 12 is also shown, which comprises a safety shading 13 which is formed as part of the housing 2 in the form of a plastic wall 14. Thus, if the converter 6 formed as a reflection converter 8 is defective, the unconverted laser light 7 of the laser diode 5 impinges on the plastic wall 14 and is absorbed by the latter.FIG. 2 shows a second embodiment of the bicycle headlamp 1 according to the invention, in which the converter 6 is formed as a transmission converter 15. In the exemplary embodiment shown, the laser light 7 generated by the laser diode 5 is directed onto the converter 6 via a deflection mirror 16 and from this the converted laser light 11 is directed onto the light optics 10. In the exemplary embodiment shown, the diode housing 4 is screwed to the housing 2 by a securing screw 17 made of plastic. The light outlet 3, which is connected to the housing 2 by ultrasonic welding, fixes and secures the light optics 10 in the housing 2.It is clear from the sectional view of the second embodiment of the two-wheeler headlight 1 according to the invention shown in FIG. 3 that, in the event of a defect in the deflecting mirror 16, the laser light 7 is absorbed by the plastic wall 14, which serves as safety shading 13 and thus as safety device 12, and is thus prevented from leaving the two-wheeler headlight 1.If, on the other hand, the transmission converter 15 is damaged, then in the exemplary embodiment shown in FIG. 4, the beam of the laser light 7 is guided through a bore 18 which is formed in the light optics 10 and serves as a securing device 12 into the plastic wall 14 of the housing 2, is absorbed there and is thus prevented from leaving the two-wheeler headlight 1 through the light outlet 3.The assembly method according to the invention is described once again below. First, a unit is preassembled in a diode housing 4, which unit comprises a laser diode 5 and a converter 6. This unit is then screwed to the housing 2 via a screw connection and the light optics 10 are then inserted into the housing 2. The light optics 10 are fixed to the housing 2 by welding the light outlet 3.List of reference characters1 Two-wheel headlight 2 Housing 3 Light outlet 4 Diode housing 5 Laser diode 6 Converter 7 Laser light 8 Reflection converter 9 Passage opening 10 Light optics 11 Converted laser light 12 Securing device 13 Safety shading 14 Plastic wall 15 Transmission converter 16 Deflection mirror 17 Securing screw 18 Bore

Claims

Two-wheeler headlight, in particular for a bicycle or an e-bike, having a housing (2) which has a light outlet (3) and in which at least one laser diode (5) is arranged which emits laser light (7) onto a converter (6) by means of which the wavelength of the laser light (7) can be converted, and having a light optics (10) for guiding the converted laser light (11) out of the light outlet (3) of the housing (2), characterized in that a safety device (12) is provided which is designed in such a way that an escape of unconverted laser light (7) from the light outlet (3) is prevented, and in that the safety device (12) comprises a safety shading (13).Two-wheeler headlight according to Claim 1, characterized in that the safety shading (13) is formed as a plastic wall (14).Two-wheeler headlight according to Claim 1 or 2, characterized in that the safety shading (13) is integrated into the housing (2).Two-wheeler headlight according to one of Claims 1 to 3, characterized in that the securing device (12) comprises a bore (18) formed in the light optics (10).Two-wheeler headlight according to one of Claims 1 to 4, characterized in that the at least one laser diode (5) and the converter (6) are accommodated in a diode housing (4).Two-wheeler headlight according to Claim 5, characterized in that the diode housing (4) is formed from metal.Two-wheeler headlight according to Claim 5 or 6, characterized in that the diode housing (4) is secured to the housing (2) by a screw connection.Two-wheeler headlight according to one of Claims 1 to 7, characterized in that the light outlet (3) is welded to the housing (2).Two-wheeler headlight according to one of Claims 1 to 8, characterized in that the converter (6) is designed as a reflection converter (8) or as a transmission converter (15).Two-wheeler headlight according to one of Claims 1 to 9, characterized in that a deflecting mirror (16) is provided for deflecting the laser light (7) onto the converter (6).Method for mounting a two-wheeler headlight (1) according to one of Claims 1 to 10, comprising the steps of: - premounting a unit comprising at least one laser diode (5) and a converter (6) in a diode housing (4), - connecting the diode housing (4) to a housing (2), and - inserting a light optics (10) into the housing (2).Method according to claim 11, characterised in that the light optics (10) are fixed to the housing (2) by welding a light outlet (3).Method according to Claim 11 or 12, characterized in that the diode housing (4) is connected to the housing (2) by means of a screw connection.

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