DE102011079093A1 - Lighting device i.e. head light, for electric bicycle, has vertically adjustable diaphragm partially switched into optical path between reflector and lens, where major axis of reflector diagonally lies on optical axis of lens - Google Patents

Abstract

The device (1) has a multi-color light generation unit (2) including an inner focal point (F1) on an ellipsoid reflector (3) i.e. half shell reflector. A lens (4) is arranged downstream to the reflector, and a vertically adjustable diaphragm (5) is partially switched into an optical path between the reflector and the lens. A major axis (R) of the reflector diagonally lies on an optical axis (O) of the lens at a range of about 5 to 40 degrees and preferably 20 degree. A cut off edge (10) of the diaphragm lies on the optical axis of the lens.

Description

The invention relates to a vehicle lighting device, comprising at least one in particular multi-colored light generating unit, an at least approximately ellipsoidal reflector, in the focal point of the light generating unit, a lens, which is connected downstream of the reflector, and a diaphragm, which partially into a beam path between the reflector and the Lens is switched. The invention can be used particularly advantageously for reducing color fringes. The invention also relates to a vehicle having such a vehicle lighting device, in particular an electric bike. The vehicle lighting device can be used particularly advantageously as a headlight of an electric wheel.

So far, occurs in a vehicle lighting device of the type mentioned in particular due to a non-symmetrical passage of the light through the lens to a significant separation or separation of light of different wavelength or color. This leads to color fringing in an image produced by the lens. Especially with a white light, which is composed for example of a mixture of blue and yellow light, yellow and blue light fringes can result disadvantageously.

It is the object of the present invention to provide a vehicle lighting device of the type mentioned, which provides in a simple way, a possibility for the reduction of color fringes.

This object is achieved according to the features of the independent claims. Preferred embodiments are in particular the dependent claims.

The object is achieved by a vehicle lighting device comprising at least (a) a multi-colored light generating unit, (b) an at least approximately ellipsoidal reflector, at the inner focus of which the light generating unit is located, (c) a lens downstream of the reflector, and (d ) An aperture, which is partially connected in a beam path between the reflector and the lens. A major axis of the reflector is oblique to an optical axis of the lens.

The light generating unit thus emits its light from a focal point in the reflector. From the reflector, the light is reflected partly on the lens and partly on the aperture. Since the reflector is at least approximately ellipsoidal, a light beam emerging from a front light exit plane from the reflector is inclined on one side in the direction of a main axis of the reflector (in the direction of a second focal point located outside the reflector). The bezel blocks the light impinging on it and creates a "cut-off" boundary or "cut-off" that is often required for vehicle lighting. Consequently, only part of the light emitted by the reflector from the reflector passes directly through the lens.

Due to the inclination of the light beam emerging from the reflector, the lens would normally only be irradiated very asymmetrically with a main axis of the reflector lying on the optical axis, so that mixed light passing through the lens at least at the edges of the image produced by the lens will strongly separate in color would. However, if the main axis of the reflector is oblique to the optical axis of the lens as in the present invention, the light beam emerging from the reflector can be directed to a larger area of the lens, and in particular to a more symmetrical portion of the lens to an optical axis of the lens Way a formation of color fringes can be at least significantly reduced.

A multicolor light-generating unit may, in particular, be understood to mean a light-generating unit whose light has a plurality of distinguishable peak wavelengths and / or distinguishable spectral bands. The term 'multicolored' can be understood here in particular as both colored and uncolored colors or color mixtures. The light-generating unit may have one or more same-colored or different-colored light sources. In particular, the light generating unit may have at least two light sources of different colors or at least one multicolor or multichrome light source. The at least one light source is preferably a semiconductor light source.

Preferably, the at least one semiconductor light source comprises at least one light-emitting diode. If several LEDs are present, they can be lit in the same color or in different colors. A color can be monochrome (eg red, green, blue, etc.) or multichrome (eg, white). The light emitted by the at least one light-emitting diode can also be an infrared light (IR LED) or an ultraviolet light (UV LED). Several light emitting diodes can produce a mixed light; z. B. a white mixed light. The at least one light-emitting diode may contain at least one wavelength-converting phosphor (conversion LED). The phosphor can alternatively or additionally be arranged remotely from the light-emitting diode ("remote phosphor"). The at least one light-emitting diode can be in the form of at least one individually housed light-emitting diode or in the form of at least one LED chip. Several LED chips can be on be mounted on a common substrate ("submount"). The at least one light emitting diode may be equipped with at least one own and / or common optics for beam guidance, z. At least one Fresnel lens, collimator, and so on. Instead of or in addition to inorganic light emitting diodes, z. Based on InGaN or AlInGaP, organic LEDs (OLEDs, eg polymer OLEDs) can generally also be used. Alternatively, the at least one semiconductor light source z. B. have at least one diode laser.

Particularly preferred is the use of at least one conversion LED emitting white light (eg with a blue light emitting emission surface and a blue light in yellow light at least partially converting phosphor) or the use of red, green and blue light or the like. emitting LEDs whose light is subsequently mixed to produce a white mixed light. The light generating unit can then be used in particular as one or with a white light headlight.

The focal point of the reflector may also be designed as an (extended) focal spot, in particular in a light-generating unit with an extended or not negligible small light-emitting surface.

It is a development that the at least one semiconductor light source has a plurality of semiconductor light sources, in particular white light LEDs, wherein the semiconductor light sources are arranged adjacent. The shape of the arrangement can influence a light emission pattern of the vehicle lighting device. The semiconductor light sources may, for example, be arranged in a quadrangular pattern (with or without a central semiconductor light source), which allows a particularly compact arrangement. Alternatively, for example, an arrangement in a staggered row pattern or a zigzag pattern is conceivable. Also, the semiconductor light sources may be arranged on a curved, in particular circular segment, line, etc.

In the presence of a plurality of semiconductor light sources, they can be activated individually or in groups in order to generate different light emission patterns (eg for on-road and off-road use).

It is a development that the lens consists of a material which has a low Abbe number (in particular less than 35). In particular, such materials can now be used with only slight or significantly reduced color fringes. The material of the lens has plastic for a simple and inexpensive production and for a low weight. The material of the lens may in particular be polycarbonate, PC, which has a typical Abbe number of about 30. The lens may alternatively z. B. of polymethyl methacrylate, PMMA exist.

It is a particularly advantageous for an application with an electric bike development that the lens has a diameter between 40 mm and 60 mm, in particular of about 50 mm. It is still a preferred development that the lens has a thickness between 15 and 25 mm, in particular between 15 and 20 mm, if it consists of PC and has a thickness between 20 and 30 mm, in particular of about 25 mm, if it is PMMA.

The lens may basically be both a full lens and a hollow lens.

The lens may be a symmetrical, in particular rotationally symmetrical, shaped or an asymmetrically shaped lens.

The lens may be configured as a gradient lens, i. H. have a local gradient of their refractive index.

The lens may be configured in one piece or in several parts.

The lens may have areas with different optical properties, e.g. B. with areas of different transparency.

The lens and / or the reflector may be at least partially surface-coated, for. B. with an anti-reflective coating and / or with a heat-reflective coating.

It is an embodiment that a main axis of the reflector by approximately 5 ° to 40 °, in particular 10 ° to 30 °, in particular by about 20 °, is angled or arranged to the optical axis of the lens. This has proven to be a particularly advantageous tendency to effectively reduce color fringing in a light-emitting characteristic suitable for a vehicle.

In addition, the main axis of the reflector may intersect with the optical axis of the lens. It is yet a further embodiment that a focal point of the lens at least substantially coincides with an outer focal point of the reflector. This allows a particularly sharp image.

The diaphragm can be configured as a solid body or as a hollow body. A diaphragm configured as a hollow body can in particular have a (eg circumferential) side edge without cover surfaces exhibit. However, the diaphragm is basically not limited in shape and need only have an edge for establishing a cut-off in the light emission pattern of the vehicle lighting device. An edge of the aperture which generates at least part of a cut-off line is referred to below as a "cut-off edge".

It is an embodiment that a cut-off edge of the diaphragm lies on the optical axis of the lens. This allows a simple design with a well-defined cut-off line. However, the invention is not limited thereto, and a cut-off edge may be at least partially also below and / or above the optical axis of the lens.

It is also an embodiment that the diaphragm is selectively removable from the beam path (and consequently also re-introduced into the beam path). Thus, the vehicle lighting device can illuminate a significantly wider field with the panel removed, which may be advantageous for example for off-road use of the vehicle. Alternatively or additionally, one or more semiconductor light sources may be provided specifically for off-road use of the vehicle and be separately activatable.

It is a development that the aperture is height adjustable and / or angle adjustable. Thus, in particular, the cut-off line can be adjusted, in particular corrected. The adjustability can be achieved for example by one or more screws.

The aperture may contact the lens or be spaced from the lens.

The shape of the aperture is not limited and can, for. B. be designed as a free-form or spline-like, in particular rotating, band. The diaphragm, in particular its cut-off edge can also have a different height.

It is also an embodiment that the reflector is a half-shell reflector. This gives the advantage of a simple beam guidance and a simple structure.

It is still an embodiment that the reflector is a free-form reflector with an ellipsoidal basic shape. Thus, adjustments to a light emission characteristic of the vehicle lighting device can be easily performed without jeopardizing a fundamental reflection property of the reflector. For example, a front edge of the reflector which defines a light exit surface may not lie on a plane. Further, for example, a front edge region may not be ellipsoidally shaped, e.g. B. be arched in profile to the outside.

The reflector may also be segmented or have multiple segments.

It is still a development that the reflector has a base body made of plastic with a, in particular specular or specular, reflective layer. This makes it possible to provide a light and inexpensive reflector with low light losses. The base body may alternatively consist of glass or metal. Alternatively, the reflector may also have a reflective surface, e.g. B. polished surface, exhibiting uncoated base body.

It is yet another embodiment that the primary light source has at least one conversion LED. So can be dispensed with a subsequent mixture of light for color homogenization.

It is furthermore an embodiment that the primary light source has at least two semiconductor light sources of different color. Thus, in particular a sum color of the resulting mixed light can be selectively changed in the case of semiconductor light sources which can be driven individually or in groups.

It is still a development that the vehicle lighting device can be switched on and off manually.

It is also a development that the vehicle lighting device is dimmable, in particular is dimmable in stages.

It is also advantageous for a long life, if the vehicle lighting device is dustproof and / or moisture-proof housed.

The vehicle lighting device can be used particularly advantageously as a headlight for an electric bike. However, the vehicle lighting device is z. B. also advantageous for other two-wheelers (such as motorcycles, etc.), for tricycles (eg., Trikes) or quads (eg, on-road quads and off-road quads), for motor vehicles (eg B. cars and trucks), for electro-assisted wheelchairs, marine lights or as position lights.

The object is also achieved by a vehicle, wherein the vehicle has at least one vehicle lighting device as described above, in particular as a headlight. The vehicle has the same advantages as the Vehicle lighting device and can be configured analog.

It is an embodiment that the vehicle is a two-wheeler, in particular an electric bike. The electric bike may also be referred to as "e-bike", etc., and may particularly refer to a bicycle with an additional or built-in electric motor. Here, a vehicle lighting device as described above can be used particularly advantageously, in particular as a headlight. However, the invention is not limited to electric bikes or other bicycles, but may include tricycles, quads, automobiles, electric assisted wheelchairs, watercraft (eg, ships), or aircraft (eg, airplanes, helicopters, etc.), etc.

In particular, the vehicle lighting device relevant operating conditions, in particular standards such as ECE standard R113 C , fulfill.

It is a particularly advantageous for use with an electric bike development that the vehicle lighting device has a length between about 80 mm and about 90 mm.

It is still another for use with a vehicle, in particular electric bike, advantageous development that the vehicle lighting device can be fed from an electrical system of the vehicle, in particular with a voltage of 12 volts.

The above-described characteristics, features and advantages of this invention, as well as the manner in which they are achieved, will become clearer and more clearly understood in connection with the following schematic description of an embodiment, which will be described in detail in conjunction with the drawings.

1 shows a sectional side view of a vehicle lighting device according to the invention and

2 shows the vehicle lighting device according to the invention in a plan view.

1 shows a sectional view in side view of a vehicle lighting device 1 , which is particularly suitable for use as a headlight of an electric bike. 2 shows the vehicle lighting device 1 in a top view.

The vehicle lighting device 1 has at least one multicolor light generating unit 2 , an approximately ellipsoidal reflector 3 , a lens 4 and a panel 5 on. These elements can be housed in a dust- and / or moisture-proof housing (not shown).

The Lens 4 has the shape of a spherical cap, which is rotationally symmetrical about its optical axis O. The optical axis O is shown lying horizontally here. The Lens 4 thus has a plano-convex basic shape, with a convex front surface 6 has a spherical shape and a flat, rear surface 7 is perpendicular to the optical axis O, which here coincides with the x-axis. The Lens 4 consists PMMA. A diameter of the lens 4 perpendicular to the optical axis O (which is a circle diameter of the plane surface 7 corresponds to) is about 50 mm at a thickness along the optical axis O of about 30 mm.

The aperture 5 has a basic body 8th in the form of a semicircular curved, circulating band. With her flat section 9 is the aperture 5 close to the flat surface 7 the lens 4 introduced, in such a way that the optical axis O of the lens 4 on an upper edge, the cut-off edge 10 , the iris 5 runs. The main body 8th is opaque, in particular light absorbing, designed. The cut-off edge 10 here spans a plane which runs horizontally and the optical axis O of the lens 4 receives.

At the furthest back or rearward point of the cut-off edge 10 , its vertex (Apex) P, there is a focal point FL of the lens 4 ,

As in particular from 2 As can be seen, the diameters of the planar surface correspond here 7 the lens 4 and the semicircular basic body 8th the aperture 5 so these two elements 4 . 8th consequently have a same width.

A horizontal plane H, in which the optical axis O of the lens 4 mentally divides the represented space into an upper half space OH and a lower half space UH. While the lens 4 is located half in the upper half space OH and the other half in the lower half space UH, is the aperture 5 in the lower half space UH.

Behind the aperture 5 (ie, from the aperture 5 off against the direction of the x-axis) is the reflector 3 , The reflector 3 is designed as a half-shell reflector with an approximately ellipsoidal free-shaped reflection surface. A front edge 11 of the reflector 3 is curved laterally forward and runs out in peaks T, as in 2 shown, as well curved upward towards the top, as in 1 shown. So the reflector 3 (or its reflection surface) slightly raised in the profile at its front edge or bent outwards.

A lower edge of the reflector 3 lies on a main plane M of the reflector 3 , which is a main axis R of the reflector 3 has as symmetry axis.

The reflector 3 has here a base body made of plastic with a specular reflective reflecting surface on its inside. In one of the reflector 3 vaulted inner focus F1 is a light exit surface (not shown) of the light generating unit 2 , The inner focus Fl can also be regarded as a focal spot due to the non-negligible light-emitting surface. An external focus F2 coincides with the focal point FL of the lens 4 together, and thus with the vertex P of the cut-off edge.

The light generation unit 2 has here three white light or blue-yellow mixed light radiating conversion light-emitting diodes (not shown). The conversion LEDs, for example, be followed by a diffuser.

With activated light-emitting diodes or activated light-generating unit 2 At the light exit surface emerging light is in the reflector 3 blasted. The reflector 3 is therefore the light generation unit 2 optically downstream. The reflector 3 is partly the lens 4 and partly the aperture 5 optically downstream. The aperture 5 is partially in a beam path between the reflector 3 and the lens 4 connected. Thus, part of the reflector 3 radiated light from the aperture 5 blocked and partially on and through the lens 4 blasted. The aperture 5 generated by means of the cut-off edge 10 in the from the lens 4 projected image (not shown), a sharp cut-off, as for example, prescribed for operation of an electric bike on the road.

In this vehicle lighting device 1 is the reflector 3 opposite the aperture 10 and the lens 4 Angled (with an axis of rotation perpendicular to the plane through the outer focus F2 of the reflector 3 or the focal point FL of the lens 4 ). More specifically, the principal plane M and the principal axis R of the reflector are 3 oblique to the optical axis O of the lens 4 and thus also to the horizontal plane H. An associated inclination angle α is here about 20 °.

That the reflector 3 Angled, can also be seen that an originally horizontally oriented reflector 3 has been turned 20 ° down (as shown anticlockwise) about the axis of rotation. However, in the case of a horizontally oriented reflector with α = 0 °, predominantly light emerges from the part of the lens located in the lower half space UH 4 leaking forward (which causes conspicuous blue and yellow color fringes due to wavelength-dependent refraction), this is applied to the lens 4 striking light at α = about 20 ° at least approximately equal to the parts of the lens 4 distributed in the upper half space OH and the lower half space UH. As a result, color mixtures can be at least partially compensated, and monochrome color fringes are suppressed.

The aperture 5 is optionally removable from the beam path and reinsert, z. B. tiltable or pivotable to illuminate a larger area can, for. As in an off-road use of the electric bike. The aperture 5 is also height-adjustable and angle-adjustable (in particular about a rotation axis perpendicular to the image plane).

A length of the vehicle lighting device 1 is between 80 mm and 90 mm.

While the invention has been further illustrated and described in detail by the illustrated embodiment, the invention is not so limited and other variations can be derived therefrom by those skilled in the art without departing from the scope of the invention.

Thus, the convex surface of the lens may also be an ellipsoidal or paraboloidal surface. Generally, the lens is not limited to convex lenses but can, for. B. also concave or convex-concave lenses. A lens may generally be understood to mean an optical imaging element or imaging system, which may also comprise a lens in the narrower sense.

Also, the aperture surface may have a different shape, for. B. an angular shape, in particular quadrangular shape.

Generally, the position and rotational position of the elements 2 to 5 the vehicle lighting device to each other vary. So the light generating unit ( 2 ) or the light exit surface against the main plane M of the reflector 3 be angled or moved out of focus F1 out. Also like the aperture 5 against the lens 4 be twisted and / or moved. In addition, for example, the outer focus of the reflector F2 does not like with the focal point FL of the lens 4 to match.

LIST OF REFERENCE NUMBERS

1

The vehicle lighting device

2

Light generating unit

3

reflector

4

lens

5

cover

6

convex, anterior surface of the lens

7

plane, rear surface of the lens

8th

Basic body of the aperture

9

flat edge surface of the panel

10

Cut-off edge

11

front edge of the reflector

α

tilt angle

F1

internal focus of the reflector

F2

Outer focus of the reflector

FL

Focal point of the lens

H

horizontal plane

M

Main level of the reflector

O

optical axis of the lens

OH

Upper half-space

P

Vertex of the cut-off edge

R

Main axis of the reflector

T

front tip of the main plane

UH

lower half space

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited non-patent literature

• ECE standard R113 C [0042]

Claims (12)

Vehicle lighting device ( 1 ), at least comprising - a multicolor light generating unit ( 2 ), - an at least approximately ellipsoidal reflector ( 3 ), at the inner focus (F1) of which the light-generating unit ( 2 ), - a lens ( 4 ), which the reflector ( 3 ), and - an aperture ( 5 ), which partially into a beam path between the reflector ( 3 ) and the lens ( 4 ), - wherein a main axis (R) of the reflector ( 3 ) obliquely to an optical axis (O) of the lens ( 4 ) lies. Vehicle lighting device ( 1 ) according to claim 1, wherein a main axis (R) of the reflector ( 3 ) by about 5 ° to 40 °, in particular by about 10 ° to 30 °, in particular by about 20 °, to the optical axis (O) of the lens ( 4 ) is at an angle. Vehicle lighting device ( 1 ) according to any one of the preceding claims, wherein a cut-off edge ( 10 ) the aperture ( 5 ) on the optical axis (O) of the lens ( 4 ) lies. Vehicle lighting device ( 1 ) according to one of the preceding claims, wherein an outer focal point (F2) of the reflector ( 3 ) at least substantially with a focal point (FL) of the lens ( 4 ) coincides. Vehicle lighting device ( 1 ) according to one of the preceding claims, wherein the diaphragm ( 5 ) is height adjustable and / or angle adjustable. Vehicle lighting device ( 1 ) according to one of the preceding claims, wherein the diaphragm ( 5 ) is optionally removable from the beam path. Vehicle lighting device ( 1 ) according to one of the preceding claims, wherein the reflector ( 3 ) is a half-shell reflector. Vehicle lighting device ( 1 ) according to one of the preceding claims, wherein the reflector ( 3 ) is a free-form reflector with an ellipsoidal basic shape. Vehicle lighting device ( 1 ) according to one of the preceding claims, wherein the light-generating unit ( 2 ) has at least one conversion LED, in particular white light emitting conversion LED. Vehicle lighting device ( 1 ) according to one of claims 1 to 8, wherein the light-generating unit ( 2 ) has at least two semiconductor light sources of different colors. Vehicle, wherein the vehicle has at least one vehicle lighting device ( 1 ) according to one of the preceding claims. The vehicle of claim 11, wherein the vehicle is an electric bike.

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