DE102012022524A1 - Light module for headlight of vehicle, has diaphragm unit which is arranged by roller that is circumferentially provided in diaphragm edges, so that roller in contact with diaphragm edges in stationary-changed focal point is tracked - Google Patents

Abstract

The module has an optical unit (12) which is provided with focus (F1,F2). A diaphragm unit (13) is arranged in the region of the focus. The diaphragm unit is arranged by a roller (14) that is circumferentially provided in the diaphragm edges (15,15a,15b), so that roller in contact with diaphragm edges in the stationary-changed focal point is tracked.

Description

The present invention relates to a light module, in particular for a headlamp of a vehicle, having a light source and a first optical unit and a second optical unit, wherein the second optical unit has at least one focus and wherein a diaphragm unit is arranged in the region of the focus.

STATE OF THE ART

The DE 10 2006 053 019 A1 shows a light module for a headlight of a vehicle with a light source and a first optical unit formed by a reflector, and a second optical unit formed by a lens device. The lens device has a focus, in which a diaphragm unit is arranged, wherein the focus of the lens device at the same time forms the focus of the reflector. By the light module, a light distribution can be provided, for example for illuminating a vehicle apron, and it is proposed that the lens device is arranged adjustable, so that the luminous width of the light distribution can be changed depending on traffic situation-dependent conditions.

To adjust the lens device along the optical axis consuming Verstellaktuatoren are necessary, in particular to ensure a very accurate adjustment of the location of the lens device.

Basically, the disadvantage with light modules is that the focus of an optical unit, and thus the distance of the focus from the optical unit, can have a temperature-dependent change in location. In particular, when the second optical unit comprises at least one plastic lens, the focus can wander, since the focal length of the second optical unit changes. To ensure that the focus coincides with the location of the diaphragm unit, so that, for example, a diaphragm edge in the light distribution in front of the vehicle can be sharply imaged, with a temperature-induced drift of the focus, the second optical unit must be tracked by the amount of the changed focal length. In the same way a tracking of the aperture unit would be possible, which, however, a high design effort arises when it must be moved transversely with high accuracy.

Also known are expansion elements in the mechanical structure of a light module, such as in the DE 10 2007 052 985 A1 shown. Herein, an expansion body is proposed as a connecting element between a support frame and a light module, wherein the light module is received by the support frame in the housing of a headlamp. The achievable adjustment in the application of expansion bodies are limited.

In particular, when the second optical unit comprises a plastic lens, particularly large local displacements of the focus can result, since the optical refractive index of the plastic material of the lens can have a strong temperature dependence. Such spatial changes of a focus can not be compensated with a simple expansion body.

In particular, plastic lenses are known that are deformable, as this example, in the EP 1 741 976 A1 be treated. In order to compensate for a temperature drift of the focus, temperature compensation means are provided, so that an illuminance distribution in the range of a given bright-dark boundary always runs below a predetermined glare threshold, as is legally required by the legislator.

DISCLOSURE OF THE INVENTION

The object of the invention is to develop a light module in particular for a headlight of a vehicle according to the features of the preamble of claim 1 so that the location of the diaphragm unit coincides with the location of the focus of the second optical unit even at a temperature change caused by a change in location of the focus.

This object is achieved on the basis of a light module according to the preamble of claim 1 in conjunction with the characterizing features. Advantageous developments of the invention are specified in the dependent claims.

The invention includes the technical teaching that the diaphragm unit is formed by a roller with a plurality of arranged on the circumference of the roller diaphragm edges, so that at an induced by temperature influence or mechanical influence change in location of the focus by rotation of the roller, a diaphragm edge in the location-changed focus trackable is.

The invention is based on the idea of achieving the tracking of the diaphragm edge in a location-changed focus caused by the influence of temperature by rotation of the roller. The particular advantage is that neither the aperture unit nor at least a part of the second optical unit must be tracked in translation to the aperture edge in the location-changed focus to lead. The diaphragm unit, like the second optical unit, can be embodied as a rigid component of the light module, and if there is a change of focus, for example as a result of a temperature-dependent change in the refractive index of at least one optical element of the second optical unit, rotation of the roller of the diaphragm unit is sufficient. to make the diaphragm edge coincide again with the focus of the second optical unit.

According to an advantageous embodiment of the light module according to the invention, the focus can be changed by the second optical unit within an interval. In particular, the focus of the second optical unit can be changed by active activation of at least one optical element of the second optical unit. For this purpose, the second optical unit may comprise at least one variable-shape lens, wherein the focus is variable by changing the shape of the lens. Due to the change in shape of the lens of the second optical unit, a light distribution of the light which can be provided by the light module, in particular of a headlight, can be changed. There is also the possibility that the second optical unit comprises a multi-lens system and / or a lens, the optical properties of which depend on the temperature, wherein the focus in the interval by changing the shape of the lens, by displacement of at least one lens along the optical axis within the multi-lens system or is changeable by temperature change.

In particular, optical systems are known which can be used for headlamps, but also for other lighting applications, which enable a variable light distribution by active control of the second optical unit. For example, the light distribution of a headlamp can be adapted to the driving situation of a vehicle, and the adaptation of the light distribution is effected, for example, by a deformable lens of the second optical unit.

If an aperture unit is then placed in the focus of the second optical unit, then it must be sharply imaged by the optical system by the aperture edge of the aperture unit in the focus of the second optical unit and is represented by this, for example, in front of the vehicle. The invention describes a plurality of diaphragm edges, which are arranged on the rotatable roller and are sharply imaged by the second optical unit depending on the position of the roller. The relative positions of the individual diaphragm edges to the imaging optics within the optical system are different. The use of a diaphragm roller in a system in which the focal length of an imaging system, ie the second optical unit, intentionally or unintentionally changes, is advantageous. Thus, thermal, but of course also mechanical influences can change the focal length of the optical system. In order to always image the contour of the diaphragm edge, for example for realizing a bright-dark boundary of the headlight, in a system of variable focal length, the positions of the diaphragm edges on the optical axis must be adjusted accordingly, which is achieved by the inventive tracking of the diaphragm edge Rotating the roller is possible.

The advantage of a rotatable roller for tracking the diaphragm edge in the location-changed focus is, in particular, that the rotation of the roller is easier to realize than a translational adjustment of the second optical unit or the diaphragm unit. From a mechanical point of view, the adaptation to the focal length of the imaging system is carried out by a simple rotational movement and correspondingly easy to use actuators. In this case, 360 ° of the roll lateral surface can be available in order to place a plurality of diaphragm edges of different contours and different relative positions relative to the imaging system. In this case, the system can respond to unwanted focal length changes, which overlap a change in the focus of the second optical unit, which are generated by driving, for example, the shape-changeable lens of the second optical unit.

For example, a shape-changeable lens may be made of a plastic material having a higher temperature dependence of the optical refractive index than, for example, lenses made of glass. The change of the focus by the second optical unit can be generated by a change in shape of the shape-changeable lens, for example by the lens being received between actuators. As a result, the focus of the second optical unit can be changed not only in its position but also in its spatial extent. In particular, the light distribution of the light provided by the light module can thus be changed, for example, to generate a city light, a country road light or, for example, a motorway light with different light distributions.

According to a further advantageous embodiment, the first optical unit may comprise a light-guiding element into which light from the light source can be coupled and which has a decoupling surface, from which the light can be coupled out of the light-guiding element and radiated against the iris unit. For example, the light guide can be made of glass or a transparent plastic, and the light guide can be received on a receiving body in or at the same time the light source is added. Further, a heat sink may be mounted on the receiving body, which serves to heat the light source, in particular because the light source may consist of one or more semiconductor light sources.

A significant advantage for tracking of diaphragm edges in a location-changed focus is achieved in that the diaphragm edges are arranged differently on the roller surface, in particular with regard to their extension direction. Further, the diaphragm edges may have different shapes, for example a straight extension and a kinking extension with respect to the radial arrangement on the surface of the roller. With respect to the roller axis in which the roller is rotatable, the diaphragm edges may have respective identical or different diaphragm contours. For example, diaphragm edges can be provided with the same diaphragm contour, but with a different shape, so that, for example, diaphragm edges with the same diaphragm contour once have a straight radial extension and once an angled extension from the roller surface. If diaphragm edges with the same aperture contour are tracked into the location-shifted focus of the second optical unit, the contour of, for example, a generated light-dark boundary of the pig-thrower can be maintained by the second optical unit. If diaphragm edges with different diaphragm contours are tracked into the location-changed focus, the different diaphragm contours can also be sharply imaged by the second optical unit in the same way.

By the optical units, an optical axis can be defined, for example, by the main axis of the propagation direction of the light provided by the light module is defined. In this case, the aperture edges can lie in tracking in the location-changed focus in the optical axis or have a height equal to each other above the optical axis. Consequently, the height of the diaphragm edge does not change relative to the optical axis, even if different diaphragm edges are tracked into the focus of the second optical unit. The change relates only to the distance of the diaphragm edge to the second optical unit, and with unchanged height of the diaphragm edge, therefore, for example, a light-dark boundary of the light distribution of the light provided by the light module remain unchanged.

According to an advantageous development of the light module, at least one temperature detection means may be provided for detecting the temperature of at least the shape-changeable lens, but a temperature detection may also be provided for the entire light module as well. Furthermore, it may be provided, for example, a focus correction control in conjunction with an adjusting unit for rotation of the roller, and the roller can be controlled in dependence on the measured temperature in the rotation, in particular such that always the diaphragm edge is guided in the optical axis in the location-changed focus lies.

PREFERRED EMBODIMENT OF THE INVENTION

Further measures improving the invention will be described in more detail below together with the description of a preferred embodiment of the invention with reference to the figures. It shows:

1 an embodiment of a light module having the features of the present invention,

2 a perspective view of a roller as a central component to form the diaphragm unit,

3 a schematic view of the optical system of the light module with a first rotated in the optical axis diaphragm edge and

4 the optical system according to 3 with a second aperture edge rotated in the optical axis.

1 shows a possible embodiment of a light module 1 with the features of the present invention in a perspective view. The light module 1 is installed in the shown or a suitably adapted form in the housing of a headlight of a vehicle, and light passing through the light module 1 can be provided, can serve to illuminate the field in front of the vehicle, for example as dipped beam.

The light module 1 has a light source 10 on, in a manner not shown in detail, for example, inside, in a receiving body 24 is included. On the receiving body 24 there is a heat sink on the back 25 which is used to heat the light source 10 serves.

Front side of the receiving body 24 is a first optical unit 11 arranged, which is a light guide unit 17 includes. The front side of the light guide unit 17 closes with a decoupling surface 18 off, and light the light source 10 can on the receiving side of the light guide unit 17 coupled into this and the decoupling surface 18 be decoupled again. The guidance of the light through the light guide 17 takes place according to the principle of the light guide with internal total reflection.

In front of the decoupling area 18 there is an aperture unit 13 which exemplifies together with the receiving body 24 on a carrier body 26 is included.

The aperture unit 13 has a roller according to the invention 14 on, around a roll axis 27 is rotatable. The rotation of the roller 14 can be done by 360 ° and with an actuator 23 be generated.

The light module 1 further comprises a second optical unit 12 , which is a variable focal length system, and the system includes, by way of example, a shape changing lens. The shape-changing lens 16 consists of a plastic body, and on the outside of the lens 16 arranged actuators 28 The shape of the plastic body can be changed. By way of example, four actuators are shown 28 , of which each have two actuators 28 in pairs.

The second optical unit 12 has a focus on the aperture edge 15 the roller 14 the aperture unit 13 lies. The light coming through the decoupling surface 18 the light guide unit 17 against the diaphragm edge 15 has been decoupled, subsequently enters the second optical unit 12 and radiates through the shape-changing lens 16 , Due to the fact that the focus of the second optical unit on the diaphragm edge 15 is, this is in front of the light module 1 sharply depicted. Will the shape of the shape-changing lens 16 by activating the actuators 28 changed, so the light distribution of the light through the module 1 provided light to be changed.

The focus of the second optical unit 12 , to the sharp picture of the diaphragm edge 15 by the distance between the lens 16 and the bezel edge 15 must be determined, can change its location due to temperature. Thus, the focus of the aperture edge 15 move out, and continue to sharp picture of the diaphragm edge 15 through the second optical unit 12 must be the distance between the bezel edge 15 and the shape-changing lens 16 be tracked.

On the surface of the roller 14 are several mutually different diaphragm edges 15 arranged, and by rotation of the roller 14 around the roll axis 27 Different aperture edges can be used in the beam path by these in the location-changed focus of the shape-changing lens 16 to be turned around. Thus, according to the invention by a simple rotation of the roller 14 the aperture edge in the location-changed focus of the second optical unit 12 be tracked. The effect of the tracking is due to the different geometric embodiments of the diaphragm edges 15 on the surface of the roller 14 achieved, which, as soon as they are rotated in the optical axis, each a different distance from the second optical unit 12 taking.

Further is a temperature sensing means 21 shown by way of example for detecting the temperature of the second optical unit 12 , especially the lens 16 , serves. The temperature detecting means 21 is with a focus correction control 22 connected to the actuator 23 can act to the roller depending on the measured temperature 14 rotate to a suitable aperture edge 15 to turn into the optical axis. It can be determined by prior detection of the focus drift as a function of temperature, at which temperature which aperture edge 15 on the roller 14 must be turned in the beam path. Consequently, depending on the temperature, the angle of rotation via the actuator 23 be set.

2 shows in a perspective view a possible form of a roller 14 with aperture edges 15 that are geometrically different. The roller 14 extends around a roll axis 27 , and the diaphragm edges 15 are at predetermined locations on the circumference of the roller 14 arranged distributed. The aperture edges 15 have an aperture contour 19 and extend in the axial direction over the roll surface. Exemplary are three diaphragm edges 15a shown, which are straight in the radial direction and extending from the surface of the roller 14 extend outward, and two more panel edges 15b have a kinked extension. The aperture edges 15a and 15b may be the same or different aperture contours 19 include, and becomes a first aperture edge 15 with a first aperture contour 19 in the focus of the second optical unit 12 against another aperture edge 15 with a different aperture contour 19 exchanged by the roller 14 is rotated, so also by the light distribution of the light through the module 1 provided light to be changed.

3 shows in a schematic view of the optical system of the light module 1 with the first optical unit 11 comprising the light source 10 , and with the second optical unit 12 , The propagation direction of the optical units 11 and 12 passing light is through an optical axis 20 indicated.

Between the optical units 11 and 12 is the aperture unit 13 comprising the roller 14 with several arranged on this edge edges 15a and 15b , By the Rotation position of the roller 14 around the roll axis 27 is the aperture edge 15b at the first location of the focus F1 of the second optical unit 12 , The through the bezel edge 15b provided aperture contour 19 can therefore via the second optical unit 12 be shown sharp.

4 shows the same optical system of the light module 1 with the first optical unit 11 and the light source 10 as well as with the second optical unit 12 , The roller 14 the aperture unit 13 is with rotation around the roll axis 27 has been rotated in the arrow direction shown so that the diaphragm edge 15a now in a second location of the focus F2, and compared to the focal length of the second optical unit 12 in 3 It can be seen that the second location of focus F2 is closer to the second optical unit 12 lies. Here, the aperture edge 15a to be rotated in the second location of focus F2, and the aperture contour 19 the aperture edge 15a lies as well as the focus F1 3 also on the optical axis 20 ,

The change in the focal length of the second optical unit 12 which causes a change of the location of the focus F1 to the location of the focus F2 can be corrected by rotation of the roller 14 so that the aperture edges 19 the aperture edge 15a and 15b equally on the optical axis 20 lie. Consequently, the glare contours 19 in both cases by the second optical unit 12 be shown sharp.

The invention is not limited in its execution to the above-mentioned preferred embodiment. Rather, a number of variants is conceivable, which makes use of the illustrated solution even with fundamentally different types of use. All of the claims, the description or the drawings resulting features and / or advantages, including design details or spatial arrangements may be essential to the invention both in itself and in a variety of combinations.

LIST OF REFERENCE NUMBERS

1

light module

10

light source

11

first optical unit

12

second optical unit

13

diaphragm unit

14

roller

15

diaphragm edge

15a

diaphragm edge

15b

diaphragm edge

16

shape changeable lens

17

light guide

18

outcoupling

19

iris contour

20

optical axis

21

Temperature sensing means

22

Focus correction control

23

actuator

24

receiving body

25

heatsink

26

support body

27

roll axis

28

actuator

F1

first place of focus

F2

second place of focus

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 patent literature

• DE 102006053019 A1 [0002]
• DE 102007052985 A1 [0005]
• EP 1741976 A1 [0007]

Claims (10)

Light module ( 1 ), in particular for a headlamp of a vehicle, with a light source ( 10 ) and a first optical unit ( 11 ) and a second optical unit ( 12 ), wherein the second optical unit ( 12 ) has at least one focus (F1, F2) and wherein in the region of the focus (F1, F2) a diaphragm unit ( 13 ), characterized in that the aperture unit ( 13 ) by a roller ( 14 ) with several on the circumference of the roller ( 14 ) arranged diaphragm edges ( 15 . 15a . 15b ) is formed, so that at a caused by temperature influence or by mechanical influence change of location of the focus (F1, F2) by rotation of the roller ( 14 ) an aperture edge ( 15 . 15a . 15b ) is trackable in the location-changed focus (F1, F2). Light module ( 1 ) according to claim 1, characterized in that the focus (F1; F2) through the second optical unit ( 12 ) is variable within an interval. Light module ( 1 ) according to claim 1 or 2, characterized in that the second optical unit ( 12 ) at least one modifiable lens ( 16 ), a multi-lens system and / or a lens, the optical properties of which depend on the temperature, wherein the focus (F1, F2) at the interval by changing the shape of the lens ( 16 ), by shifting at least one lens along the optical axis within the multi-lens system or by changing the temperature is variable. Light module ( 1 ) according to one of claims 1 to 3, characterized in that the first optical unit ( 11 ) a light-conducting element ( 17 ) into the light from the light source ( 10 ) can be coupled and that a decoupling surface ( 18 ), from which the light from the light guide element ( 17 ) and against the aperture unit ( 13 ) is radiant. Light module ( 1 ) according to one of the preceding claims, characterized in that the diaphragm edges ( 15 . 15a . 15b ) are arranged differently on the roll surface, in particular with regard to their extension direction. Light module ( 1 ) according to one of the preceding claims, characterized in that the diaphragm edges ( 15 . 15a . 15b ) have a different shape, in particular that at least one diaphragm edge ( 15 . 15a . 15b ) a straight extension and that at least one diaphragm edge ( 15 . 15a . 15b ) has a kinkend extension. Light module ( 1 ) according to one of the preceding claims, characterized in that the diaphragm edges ( 15 . 15a . 15b ) a respective aperture contour ( 19 ) that are the same or different from each other. Light module ( 1 ) according to one of the preceding claims, characterized in that by the optical units ( 11 . 12 ) an optical axis ( 20 ), wherein the diaphragm edges ( 15 . 15a . 15b ) when tracking in a location-changed focus (F1, F2) respectively on or near the same optical axis ( 20 ) lie. Light module ( 1 ) according to one of the preceding claims, characterized in that by a focus change of the second optical unit ( 12 ) within the interval (F1, F2) a light distribution of the light through the light module ( 1 ) light, in particular the headlamp, is changeable. Light module ( 1 ) according to one of the preceding claims, characterized in that at least one temperature detection means ( 21 ) for detecting the temperature of at least the second optical unit ( 12 ), and wherein by a focus correction control ( 22 ) in conjunction with an actuator ( 23 ) a rotation of the roller ( 14 ) is controllable in dependence of the measured temperature.

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