Lighting device for vehicles and methods

Abstract

Lighting device for vehicles with a light source (3, 13, 13', 23) and with a reflector unit assigned to the light source (3, 13, 13', 23), which deflects a light beam emitted by the light source (3, 13, 13', 23) in the main emission direction (H) to produce a predetermined light distribution (L V ) and with a drive unit (7) for generating a relative movement between the light source (3, 13, 13', 23) and the reflector unit, characterized in that the reflector unit has a fixed reflector (4, 14, 24) and that the light source (3, 13, 13', 23) is arranged so as to be rotatable on a circular focal line (B) of the fixed reflector (4, 14, 24) and that the drive unit (7) sets the light source (3, 13, 13', 23) in motion in such a way that a predetermined light distribution (Lv) is generated by a plurality of partial light distributions (L1, L2, L3, L n) is formed.

Description

[0001] The invention relates to a lighting device for vehicles according to the preamble of patent claim 1.

[0002] US Pat. No. 7,901,122 B2 discloses a lighting device for vehicles comprising a light source and a reflector associated with the light source. The light source is rotatably mounted by means of a drive unit, allowing it to assume two different positions relative to the reflector. A first light distribution can be generated in a first relative position, and a second light distribution can be generated in a second relative position. This second light distribution differs from the first light distribution, for example, in that it is particularly suitable for use on wet roads. The known lighting device enables the provision of multiple light distributions, with the light source always being in a defined position relative to the reflector to generate the light distribution.

[0003] US 2012 / 0314439 A1 discloses a lighting device for vehicles comprising a light source and a reflector unit, in which the light source interacts with a diaphragm. By rotating the light source using a drive unit, the edge region of the generated light distribution can be changed. The generation of different light distributions by continuously moving the light source relative to the reflector unit is not provided for there.

[0004] US 2009 / 0046474 A1 discloses a lighting device for vehicles comprising a light source and a reflector associated with the light source. A broadening of the light distribution can be achieved by moving the reflector back and forth.

[0005] The object of the present invention is to further develop a lighting device for vehicles and a lighting method in such a way that a plurality of light distributions can be generated in a space-saving manner.

[0006] To solve this problem, the invention has the features of patent claim 1.

[0007] The invention enables alternative generation of light distributions. According to the invention, a drive unit is provided so that a relative movement always occurs between a light source and a reflector unit or a reflector to generate the light distribution. The relative movement occurs as a rotational movement. If the relative movement occurs at a relatively low speed, several partial light distributions perceptible to the eye are generated. If the relative movement occurs at a relatively high speed, only a single light distribution formed from running partial light distributions is perceived. Any flickering of the running partial light distributions that would otherwise occur at lower relative speeds is then no longer perceptible to the human eye. The relative speed should be selected to be high enough that the observer sees a "fixed" reflection image of the reflector.It can be assumed that a light distribution is only ever generated when the light source is positioned at a focal point or along a focal line of the reflector. By varying the relative speed, the light intensity emitted by the lighting device into the surrounding area can be controlled, so that, for example, a brake light and a tail light function can be generated using the same lighting device.

[0008] According to a further development of the invention, several light sources can be arranged along a focal circle of the fixed reflector, thereby increasing the luminous flux captured by the reflector. This improves the variation options regarding the emitted luminous intensity and thus the different light distributions.

[0009] According to a further development of the invention, the light source is mounted for rotation about a rotation axis. Preferably, the light source is switched on only in one area of ​​the focal point or focal line of the fixed reflector and is switched off in the other area during movement. In this way, incorrect light emission can be prevented.

[0010] According to a further development of the invention, the light source can be arranged on a support that has another light source or an additional optical element positioned upstream on a side facing away from the fixed reflector. This can advantageously increase the efficiency. Furthermore, it ensures that a reflecting surface of the fixed reflector appears bright even though it is covered by the light source.

[0011] According to a further development of the invention, at least one light source can also be stationary, with a deflecting reflector associated with the light source being rotatably mounted. The deflecting reflector is shaped in such a way that it deflects the light emitted by the light source toward the stationary reflector, which emits the light in the main radiation direction. This advantageously minimizes the movement effort, since the movable deflecting reflector requires no electrical connections.

[0012] According to a further development of the invention, areas of the reflector surface are shaped in such a way that a partial light beam incident on the area contributes exclusively to a partial area of ​​the light distribution. This advantageously allows, for example, 45° light values ​​inside the vehicle or 80° light values ​​outside the vehicle to be directly controlled.

[0013] According to a further development of the invention, a region of the reflector surfaces can be shaped such that a light beam striking it is redirected to form the entire light distribution. In this case, all regions of the reflector surfaces, i.e., their optical elements, are shaped such that a complete partial light distribution is created. Segmentation of the light distribution, in which different subregions of the light distribution are illuminated by different regions of the reflector surfaces, does not occur.

[0014] To achieve this object, the method according to the invention has the features of patent claim 12.

[0015] According to the method according to the invention, a light distribution is generated by sequentially superimposing partial light distributions, whereby the partial light distributions are formed by relative movement between the light source and an optical unit. The relative movement occurs at such a speed that the individual partial light distributions, which may differ from one another, are not perceptible but "merge" into a resulting light distribution. This results in a continuous image of partial light distributions that, due to the increased speed, is not perceived as a flickering or shimmering image, but rather forms a single resulting light distribution.

[0016] According to the invention, the relative movement occurs through a continuous rotational movement. The rotational movement accepts that the light emitted by the light source is not shaped during part of the rotation. Advantageously, however, the control of the relative movement can be made simpler.

[0017] Further advantages of the invention emerge from the further subclaims.

[0018] Embodiments of the invention are explained in more detail below with reference to the drawings.

[0019] They show: Fig. 1 a schematic side view of a lighting device according to a first embodiment, Fig. 2 is a schematic representation of a moving light source according to the first embodiment of the invention, Fig. 3 a timing diagram for the first embodiment of the lighting device, Fig. 4 a schematic plan view of a lighting device according to a second embodiment, Fig. 5 a perspective view of a lighting device according to a third embodiment and Fig. 6 a side view of the lighting device according to Fig. 5.

[0020] A lighting device according to the invention can be provided for generating signaling functions in a headlight or in a rear light of a vehicle.

[0021] According to a first embodiment of the invention according to the Fig. 1, the lighting device comprises two lighting modules 1, 2, each having a light source 3 and a reflector unit or optical unit 4. The reflector unit has a fixed reflector 4. The light source 3 is designed as an LED light source or as another semiconductor-based light source. The light source 3 is located on both sides of a disc-shaped carrier 5, which is designed as a rigid circuit board. The circuit board 5 interacts via coupling means 6 with a drive unit 7 designed as an electric motor, wherein the circuit board 5 is mounted for rotation about a rotation axis D1.

[0022] How Fig. As illustrated in Figure 2, three light sources 3, and thus several light sources 3, can be arranged on one side of the circuit board 5. The light sources 3 are arranged at a constant distance R from the rotation axis D1 and run along a focal line B x, of the fixed reflector 4. The fixed reflector 4 is ellipsoidal or parabolic in shape and is directed towards the light sources 3, which are arranged at a focal point or on a focal line B of the fixed reflector 4 having the focal point. In the present exemplary embodiment, the focal line B is circular. Due to the dome-like shape of the reflector 4, usable light is only emitted in a main emission direction H if the light sources 3 extend within a detection area 8 of the reflector 4. If the light sources 3 are located outside of this circular segment-like detection area 8, which encloses an acute or obtuse angle, the light sources 3 are switched off by means of a control device (not shown), so that no extraneous light can be emitted.

[0023] During operation of the lighting device, the circuit board 5 is driven at a constant rotational speed d (angular velocity) in a rotational direction 10. In a switching-on period T E of the light sources 3, the light L emitted by them is transformed or reflected by the reflector 4 in the main emission direction H. If the light sources 3 are located in an area remote from the focal point or focal line B, they are switched off for a switch-off time T A switched off. The duty cycle T E and the off time T A together form the period T, which represents one revolution of the circuit board 5.

[0024] During the operating time T E In a time interval Δt, light distributions L1, L2, L3, L ngenerated, of which at least two are different from each other. The rotational speed of the circuit board 5 is selected so high that a viewer can perceive a resulting light distribution Lv, which is composed of the sequentially generated partial light distributions L1, L2, L3, L n composed.

[0025] The circuit board 5 can, for example, be operated at a first speed, which serves to generate a tail light distribution. If the speed of the circuit board 5 is increased to a second speed, the luminous flux acting on the reflector 4 is increased, so that, for example, a brake light distribution can be generated. Alternatively, a position light and daytime running light distribution can also be generated by two different rotation speeds, which produce different luminous intensities.

[0026] According to the embodiment of the invention according to Fig. 1, a reflector surface of the reflector 4 has a number of pincushion optical elements, strip optical elements, or prism optical elements. The circuit board 5, with its light sources 3 arranged on both sides, is arranged in a manner covered by a screen 9 in the main radiation direction H.

[0027] According to a first variant of the reflector 4, the reflector surfaces are shaped such that a light beam L from the light source 3 striking them is always redirected into a complete light distribution. All areas of the reflector surfaces thus contribute to providing the same light distribution or partial light distribution.

[0028] According to a second alternative for reflector 4, the areas of the reflector surfaces can also be shaped such that a light beam L striking them is deflected exclusively in a sub-area of ​​the light distribution or partial light distribution to be generated. For example, certain areas of the reflector surface can be used for 45° light values ​​inside the vehicle and 80° light values ​​outside the vehicle. This creates a wide visibility of reflector 4 and a reliable design of the light distribution.

[0029] According to an embodiment of the lighting device not covered by the patent claims, the relative movement between the optical unit 4 and the light source 3 can be achieved by a periodic back-and-forth movement of the circuit board 5. In this case, the circuit board 5, which sweeps through an acute or obtuse angle, is moved back and forth between two end positions. Advantageously, in this variant, the light sources 3 do not need to be switched off. The luminous flux of the light sources 13, 13' can be continuously used to form the partial light distributions L1, L2, L3, L n or serve to distribute light.

[0030] According to a further embodiment of the invention according to Fig. 4, a plate-shaped carrier (circuit board) 15, together with light sources 13, 13' arranged on both sides, can also be moved about a rotation axis D2, which, in contrast to the circuit board 5 according to the first embodiment, intersects the circuit board 15 only in a single rotational position thereof. An optical unit 16, which in the present embodiment is designed as a Fresnel lens, is arranged in front of the light source 13, 13' facing away from a fixed reflector 14. Alternatively, the optical unit can also comprise a lens and / or a reflector. In this way, it is always ensured that the carrier 15 arranged in front of the reflector 14 in the main radiation direction H does not appear dark, which leads to a harmonious light emission appearance. In addition, the light emitted by the light source 13' can be used for a lighting function.

[0031] According to a further embodiment of the invention according to the Fig. 5 and Fig. 6, a lighting device is provided in which a light source 23 is stationary. The light sources 23 are arranged in a circular ring in a plane. A deflecting reflector 25 is assigned to the light sources 23 and is mounted so as to be rotatable about a rotation axis D3. The deflecting reflector 25 has a smaller dimension than a fixed reflector 24, which emits the light deflected by the deflecting reflector 25 in the main radiation direction H to generate the light distribution. The dimension of the deflecting reflector 25 in the direction of rotation 10 is significantly smaller than the dimension of the reflector 24 and / or essentially corresponds to the dimension in the circumferential direction 10 of the light sources 23. As the deflecting reflector 25 rotates, light beams from the light sources 23 are thus gradually deflected onto the reflector surfaces of the reflector 24. According to this embodiment, the reflector unit or optical unit is formed by the fixed reflector 24 and the deflection reflector 25.

[0032] The fixed reflector 24 is arranged in a trough-shaped and / or circular shape, so that the light of the light sources 23 arranged on a focal line of the reflector 24 is emitted to form an approximately equal partial light distribution. According to the time diagram in Fig. 3, partial light distributions are generated, resulting in a light distribution Lv. The deflection reflector 25, like the circuit board 5, is moved at a constant rotational speed d.

[0033] According to an alternative embodiment not covered by the patent claims, the deflecting reflector 25 can also be moved back and forth between two end positions, so that the luminous flux can be increased. The reflector 4, 14, 24 can alternatively be spherical or designed as a free-form reflector. List of reference symbols 1 lighting module 2 lighting modules 3 Light source 4 Optical unit / reflector 5 carrier / circuit board 6 Coupling agents 7 Drive unit 8 Detection range 9 Screen 10 Direction of rotation 13, 13' light source 14 Reflector 15 carriers 16 Optical unit 23 Light source 24 reflector 25 Deflection reflector B focal line R distance H Main radiation direction T E Switch-on period L Light T A Switch-off time T period duration D1,D2,D3 rotation axis Δt time interval L V Light distribution L1, L2, L3, L n Partial light distribution d rotation speed

Claims

[1] Lighting device for vehicles with a light source (3, 13, 13', 23) and with a reflector unit assigned to the light source (3, 13, 13', 23), which deflects a light beam emitted by the light source (3, 13, 13', 23) in the main emission direction (H) to produce a predetermined light distribution (L V ) and with a drive unit (7) for generating a relative movement between the light source (3, 13, 13', 23) and the reflector unit, characterized by that the reflector unit has a fixed reflector (4, 14, 24) and that the light source (3, 13, 13', 23) is arranged to be rotatable on a circular focal line (B) of the fixed reflector (4, 14, 24) and that the drive unit (7) sets the light source (3, 13, 13', 23) in motion in such a way that a predetermined light distribution (Lv) is generated by a plurality of partial light distributions (L1, L2, L3, L n) is formed. [2] Lighting device according to claim 1, characterized by that several light sources (3, 13, 13', 23) arranged on the focal line (B) are provided as the light source (3, 13, 13', 23) in order to increase a luminous flux detected by the fixed reflector (4, 14, 24). [3] Lighting device according to claim 1 or 2, characterized by that light distributions (Lv) with different light intensities can be set depending on a rotational speed (d) between the light source (3, 13, 13', 23) and the fixed reflector (4, 14, 24). [4] Lighting device according to one of claims 1 to 3, characterized by that the light source (3) is switched on exclusively in a detection area (8) of the fixed reflector (4). [5] Lighting device according to one of claims 1 to 4, characterized bythat the light source (13) is arranged on a support (5) which has a further light source (13') on a side facing away from the fixed reflector (14), in front of which an optical unit (16) is arranged for emitting a further light beam. [6] Lighting device according to one of claims 1 to 5, characterized by that a plurality of light sources (23) arranged on the focal line (B) of the fixed reflector (24) are designed to be fixed, and that the reflector unit additionally has a rotatably mounted deflection reflector (25) assigned to the light source (23), which deflects the light emitted by at least part of the light source (23) in the direction of the fixed reflector (24). [7] Lighting device according to claim 6, characterized by that the deflection reflector (25) has a smaller dimension in the direction of rotation than the fixed reflector (24). [8] Lighting device according to claim 5 characterized bythat the carrier (5) is designed as a rigid printed circuit board and the light source (3, 13, 13', 23) is designed as a semiconductor-based light source. [9] Lighting device according to one of claims 1 to 8, characterized by that the fixed reflector (4, 14, 24) is parabolic or ellipsoidal or spherical or is designed as a free-form reflector. [10] Lighting device according to one of claims 1 to 9, characterized by that the fixed reflector (4, 14, 24) has a reflector surface with a plurality of cushion optical elements or strip optical elements or prism optical elements. [11] Lighting device according to claim 10, characterized bythat an area of ​​the reflector surfaces is shaped such that a light beam (Lv) striking it produces exclusively a partial area of ​​the predetermined light distribution and / or that an area of ​​the reflector surfaces is shaped such that a light beam striking it contributes completely to the predetermined light distribution. [12] Method for generating a predetermined light distribution (Lv) for vehicles, wherein a light source (3, 13, 13', 23) is moved relative to an optical unit (4, 14, 24) forming a light beam emitted by the light source (3, 13, 13', 23), characterized bythat the relative movement between the light source (3, 13, 13', 23) and the optical unit (4, 14, 24) takes place as a rotational movement in a direction of rotation (10) and that the relative movement between the light source (3, 13, 13', 23) and the optical unit (4, 14, 24) takes place at a speed such that the light distribution (Lv) takes place by sequential superposition of a plurality of partial light distributions (L1, L2, L3, L4), wherein the partial light distributions (L1, L2, L3, L4) are dependent on a current relative position of the light source to the optical unit. [13] Method according to claim 12, characterized by that the light source (3, 13, 13') is continuously moved at a constant speed relative to the optical unit.

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