DE102016209946A1 - Apparatus and method for projecting a light pattern - Google Patents

Abstract

The invention provides a device (10) and a method of apparatus for projecting a light pattern (70). The device (10) is formed with: a supercontinuum laser device (12), by means of which a white laser beam (51) can be generated; a selector means (14) by means of which the generated white laser beam (51) for projecting the light pattern (70) can be selectively guided into a number of solid angle ranges; and a diffuser (16) which is arranged in the beam path of the laser beam (51) generated before or after the selector device (14).

Description

The present invention relates to an apparatus and a method for projecting a light pattern. The device can in particular be used as an adaptive headlight or as part of an adaptive headlight, as a tail light or direction change indicator or as part of a tail light or direction change indicator, in particular in a vehicle.

State of the art

In modern headlamp systems for vehicles partially adaptive headlamp systems used, which allow to adapt a lighting direction or a lighting profile of the headlamp system dynamically to a traffic situation. For example, in the so-called cornering light, a vehicle headlamp is controlled so that its light cone follows a curve that drives the vehicle with the headlamp, instead of tangentially out of the curve to light.

For example, headlamp systems that are capable of projecting light patterns that are adaptable to the traffic can be controlled so that an oncoming vehicle is purposefully excluded from the light cone of the headlamp system.

In the US 2010/079836 A1 a laser scanner for projecting a light pattern is described.

Supercontinuum (supercontinuum) lasers are used occasionally in the scientific environment and are based on the so-called supercontinuum generation. Supercontinuum generation is a process in which laser light is converted to light with a very broad spectral bandwidth, with spatial coherence usually staying high. Spectral broadening is usually accomplished by passing an original optical pulse through a highly nonlinear optical element. Such elements may be, for example, optical fibers having a waveguiding structure or photonic crystal fibers. The laser beam generated by the supercontinuum generation is also called a "white laser beam" because of its broad spectrum and its effect on the human eye.

Disclosure of the invention

The present invention discloses an apparatus for projecting a light pattern having the features of claim 1 and a method for projecting a light pattern having the features of claim 10.

Accordingly, there is provided an apparatus for projecting a light pattern, comprising: a supercontinuum laser device by means of which a white laser beam can be generated; a selector means by which the generated white laser beam for projecting the light pattern can be selectively guided into a number of solid angle ranges; and a diffuser, which is arranged in the beam path of the laser beam generated before or after the selector device. In particular, the diffuser serves to expand the laser beam to improve e.g. the eye safety. In particular, the diffuser comprises glass or plastic having a structure for expanding coherent laser radiation.

Furthermore, there is provided a method of projecting a light pattern, comprising the steps of: controlling a supercontinuum laser device to generate a white laser beam; and selectively directing the generated white laser beam into a plurality of solid angle regions for projecting the light pattern such that a diffusion plate is disposed in the beam path of the generated laser beam.

Advantages of the invention

The device according to the invention provides a laser beam with a particularly broad spectrum, for example with proportions with all, or with essentially all, wavelengths from 400 to 1700 nanometers. Light from the visible spectrum of the laser beam can be used for illumination, for example, a road. At the same time, invisible portions, e.g. Infrared light portions of the projected laser beam can be used for illumination and detection, for example for LIDAR applications. For LIDAR systems, for example, laser light having a near-infrared wavelength (NIR) of e.g. 1064 nanometers good.

The laser beam provided by the supercontinuum laser device has a high beam quality, which can simplify the optical beam path through the device. Thus, the dimensioning of the selector device and other optical components in the beam path can be reduced, whereby the dimensioning of the device is overall advantageously reduced.

Furthermore, it can be advantageous to dispense with the provision or use of a phosphorus converter. Phosphor converters usually convert - with corresponding losses - blue laser light in a mixture of blue and yellow laser light to obtain a total of white laser light. Compared to solutions with phosphorus converters, a color temperature of the laser beam used for projecting the light pattern can be adjusted during operation according to the invention.

Compared to solutions using high power laser diodes for generating laser beams for projecting light patterns, the solution according to the invention has a longer lifetime.

Advantageous embodiments and further developments emerge from the dependent claims and from the description with reference to the figures.

According to an advantageous development, the selector device is designed as a deflection device, which is designed to deflect the white laser beam. The deflection device can have, for example, one or more micromirrors. Thus, a spatial area in the manner of a laser scanner can be scanned to project the light pattern.

According to a further advantageous embodiment, the selector device is designed as an array of selectively the laser beam forwarding or non-forwarding switchable pixels. The device is thus advantageously usable in so-called DLP projectors, for example as a projector, i. as an image projector. In this case, the light pattern to be projected may be, for example, a photograph, a video, a presentation slide, or the like. Furthermore, the device can also be advantageously used for illuminating objects detected by external devices.

According to a further advantageous development, the array is an array of micro-optics. According to a further advantageous development, the array is a Grating Light Valve (GLV). Grating Light Valves allow a high brightness of the light pattern to be projected and good contrast values. They offer a high resolution and can be produced with relatively little technical effort.

According to a further advantageous development, the white laser beam is conducted from the supercontinuum laser device to the selector device in an optical fiber. As a result, the location of the laser generation and the location of the laser selection (for example deflection) can be separated from each other, which in turn allows additional design freedom and better cooling possibilities.

According to a further advantageous development, a filter device for modifying a color temperature and / or for modifying a spectrum composition of the laser beam is arranged in the beam path of the white laser beam. As a result, the laser beam for a variety of applications is customizable.

According to a further advantageous embodiment, the device is designed as a portable or stationary projector. According to a further advantageous development, the device is designed as a headlight, in particular as a vehicle headlight or as a headlight installed on a building. According to a further preferred development, the device is designed as a tail light or as a direction change indicator.

Brief description of the drawings

The present invention will be explained in more detail with reference to the embodiments illustrated in the schematic figures of the drawings. Show it:

1 a schematic block diagram of an apparatus for projecting a light pattern according to a first embodiment of the present invention;

2 a graph illustrating an advantageous optical transmission power distribution as a function of a radiation angle;

3 a schematic block diagram of an apparatus for projecting a light pattern according to yet another embodiment of the present invention;

4 a schematic block diagram of an apparatus for projecting a light pattern according to yet another embodiment of the present invention;

5 a schematic block diagram of an apparatus for projecting a light pattern according to yet another embodiment of the present invention; and

6 FIG. 12 is a schematic flowchart for explaining a method of projecting a light pattern according to another embodiment of the present invention. FIG.

In all figures, the same or functionally identical elements and devices - unless otherwise stated - provided with the same reference numerals. The numbering of process steps is for clarity and should in particular, unless otherwise stated, imply a particular chronological order. In particular, several method steps can be carried out simultaneously.

Description of the embodiments

1 shows a schematic block diagram of a device 10 for projecting a light pattern 70 according to a first embodiment of the present invention.

The device 10 includes a supercontinuum laser device 12 which is designed or set up, a white laser beam 51 using a supercontinuum generation, that is, a laser beam 51 which has a supercontinuum.

By means of a selector device 14 the device 10 is that through the supercontinuum laser device 12 generated white laser beam 51 selectively for projecting the light pattern 70 into a number of solid angle ranges conductive. The supercontinuum laser device 12 can, for example, based on an internal programming or an externally given control signal, each dependent on the solid angle range in which the white laser beam 51 currently through the selector device 14 would be controlled, for example by a control device, the white laser beam 51 currently to create or not to produce.

Will the laser beam 51 Thus, a white pixel is generated or generated in the corresponding solid angle range. Will not be a laser beam 51 generated, in the corresponding solid angle range thus a dark or black pixel is generated or generated. By using corresponding color filters, a white pixel can be converted accordingly into a colorful pixel, for example a red, green or blue pixel.

The projected light pattern 70 Thus, it can be formed as a totality of white and black, and possibly also of colored and black pixels, and can thus represent, for example, a photograph or yield a spatially resolved light cone of a headlight. The device 10 Thus, it may in particular be designed as a headlight of a vehicle or be integrated in a headlight of a vehicle and may serve to provide an adaptive light cone of the headlight, for example a so-called cornering light. Also applications in or as taillights or direction change indicator (turn signals) are advantageous.

Between the supercontinuum laser device 12 and the selector device 14 , or as part of the supercontinuum laser device 12 Optionally, a shutter may be provided to pass through the supercontinuum laser device 12 generated laser beam 51 to interrupt. Creating a black pixel in the light pattern 70 can thus also by actuation of the shutter to interrupt the generated laser beam 51 will be realized.

In the device 10 is in the beam path of the generated laser beam 51 after the selector device 14 a diffuser 16 the device 10 arranged. The diffuser 16 is also denominatable as a diffuser. A diffusing screen is an optical component which is used to diffuse light, in particular using the effects of diffuse reflection while refracting light.

The diffuser 16 For example, it may be configured as described below with reference to FIG 2 described.

2 shows an advantageous transmission power curve 81 , ie a transmission power distribution, which, for example, by a lens 16 can be provided, which has been prepared by forming a polymer structure on a glass ("polymer-on-glass"), ie which consists of a polymer structure arranged on a glass or has a polymer structure arranged on a glass. Depending on the desired site of use, the polymer structure may be formed with a predefined roughness in order to have corresponding scattering properties. About the transmission power curve 81 In particular, the diffuser may have an intensity and a spot size of the device 10 decoupled combined laser beam 54 be set.

Transmission power curves 81 with a shallower maximum are preferred since these have a lower energy density of the laser beam 54 at a beam angle 71 of 0 °.

The diffuser 16 can be described below, advantageous characteristics with respect to their normalized optical transmission power 72 for certain beam angles 71 of the deflected laser beam 51 after passing through the lens 16 exhibit. The normalized optical transmission means an optical transmission power which is normalized so that the maximum of the optical transmission is set to the value 1.0 and the minimum to the value 0.0.

Preferably, the lens 16 for radiation angle 71 the deflected combined laser beam 51 after passing through the lens 16 with an amount between 0 ° and a first Abstrahlwinkelbetragswert a normalized optical transmission power of more than 0.5, in particular more than 0.6, more preferably of more than 0.7. The first Abstrahlwinkelbetragswert is greater than or equal to five degrees, preferably greater than or equal to ten degrees, in particular greater than or equal to fifteen degrees.

Furthermore, the diffuser 16 preferably for emission angle 71 of the laser beam 51 after passing through the lens 16 with an amount greater than or equal to a second Abstrahlwinkelbetragswert a normalized optical transmission power of less than 0.5, in particular less than 0.3, more preferably less than 0.2.

The second irradiation angle amount value is equal to the first irradiation angle amount value or is, preferably, larger than the first irradiation angle amount value. The second radiation angle value is preferably greater than or equal to five degrees, more preferably greater than or equal to ten degrees, in particular greater than or equal to fifteen degrees or greater than or equal to twenty degrees. The second radiation angle amount value is also preferably less than or equal to thirty degrees, more preferably less than or equal to twenty-five degrees, in particular less than or equal to twenty degrees.

The first and / or second Abstrahlwinkelbetragswert are preferably both between 10 ° and 20 °, in particular between 15 ° and 20 °. Alternatively, or additionally, the first and / or second Abstrahlwinkelbetragswert each other preferably less than 10 °, in particular less than 5 ° apart. In principle, those configurations are particularly preferred which result in a particularly steep drop in the normalized optical transmission power.

In addition, a rotationally symmetrical distribution of the normalized optical transmission power, ie a distribution which only depends on the magnitude of the radiation angle, is particularly preferred 71 but not from the orientation of the radiation angle 71 around the normal on the lens 16 around. For other applications, the lens may 16 also be configured to form a rectangular, in particular square, distribution of the optical transmission.

The described properties of the lens 16 with respect to the normalized optical transmission power are advantageous for forming an advantageous beam profile through the lens 16 , On the one hand, a particularly narrow emission profile, that is to say a 0 ° decaying normalized optical transmission power, is advantageous in order to project the light pattern with high resolution. On the other hand, such narrow beam profiles can result in an undesirably high light intensity, in particular at 0 °. The aforementioned radiation properties of the diffuser provide a favorable balance between these two conflicting interests.

Particularly preferred is a lens 16 with the characteristics passing through the curve 81 or by an idealized curve 85 in 2 being represented.

Accordingly, a diffuser 16 particularly preferred, which for radiation angle 71 the deflected combined laser beam 54 to the normal on the lens 16 after passing through the lens 16 has: for radiation angle 71 with an amount between 0 ° and a first Abstrahlwinkelbetragswert a normalized optical transmission power of more than 0.5, in particular more than 0.6, more preferably greater than 0.7; and for radiation angles 71 with an amount greater than or equal to a second Abstrahlwinkelbetragswert a normalized optical transmission power of less than 0.5, in particular less than 0.3, more preferably less than 0.2.

3 shows a schematic block diagram of a device 110 for projecting a light pattern 70 according to yet another embodiment of the present invention. The device 110 is a variant of the device 10 and differs from this in that a selector device 114 the device 110 instead of the selector device 14 the device 10 is provided.

The selector device 114 is specifically as a deflector 114 formed, which for deflecting the white laser beam 51 in accordance with a respective current deflection state of the deflection device 114 is set up. The deflection device 114 For example, as an actuatable micromirror or a number of in the beam path of the laser beam 51 be arranged successively arranged micromirrors, wherein the micromirror or the number of micromirrors are so aktuierbar, for example by an actuator of the deflection 114 that the laser beam 51 for scanning a predetermined solid angle and / or a decoupling device of the device 110 is distracted. By the deflection device 114 can the laser beam 51 in one dimension, preferably in two dimensions, be distractable.

An optional decoupling device 118 the device 110 is set up or designed to be the projected light pattern 70 from the device 110 for example, in the case of a vehicle headlight, in the environment of To lead vehicle. The decoupling device 118 For example, it may comprise secondary optics, consist of secondary optics, have or consist of a cover, and the like.

Between the supercontinuum laser device 12 and the deflector 114 Can be an optional fiber optic device 120 be provided, which is designed or set up, the laser beam generated 51 from the supercontinuum laser device 12 starting to conduct by means of glass fibers. As a result, the generated laser beam 51 especially lossless conductive and there is a structural and spatial separation between the supercontinuum laser device 12 and the selector device 114 achievable. This spatial separation is particularly advantageous for cooling purposes and may allow for greater design freedom.

The device 110 is in accordance with all with respect to the device 10 described modifications and developments, in particular with regard to the lens 16 , customizable and vice versa.

4 shows a schematic block diagram of a device 210 for projecting a light pattern 70 according to yet another embodiment of the present invention. The device 210 is a variant of the device 10 and differs from this in that in the device 210 the diffuser 16 in the beam path of the laser beam 51 between the supercontinuum laser device 12 and the selector device 14 is arranged. Incidentally, the individual elements of the device 210 be designed as well as with respect to the devices 10 ; 110 described, especially what the diffuser 16 As. The device 210 can also be an optional output device 118 as with respect to the device 110 described in the foregoing.

Between the supercontinuum laser device 12 and the diffuser 16 Can be an optional fiber optic device 220 be provided, which is designed or set up, the laser beam generated 51 from the supercontinuum laser device 12 starting to conduct by means of glass fibers. As a result, the generated laser beam 51 especially lossless conductive and there is a structural and spatial separation between the supercontinuum laser device 12 and the diffuser 16 reachable. This spatial separation is particularly advantageous for cooling purposes and may allow for greater design freedom.

5 shows a schematic block diagram of a device 310 for projecting a light pattern 70 according to yet another embodiment of the present invention. The device 310 is a variant of the device 210 and according to all, with respect to the device 210 described modifications and developments adaptable and vice versa.

The device 310 is different from the device 210 in that a selector device 314 the device 310 instead of the selector device 14 the device 210 is provided.

The selector device 314 the device 310 is as an array of selectively the laser beam 51 formed further forward or non-forwarding switchable pixels. The supercontinuum laser source 12 and the diffuser 16 are at the device 310 preferably designed and arranged such that the laser beam 51 the array 314 fully lit.

This can, for example, the lens 16 for expanding the originally narrower generated laser beam 51 be provided. By selectively forwarding or not forwarding the pixels of the array 314 thus results in the beam path behind the array 314 the light pattern to be projected 70 , Also the device 310 can be an optional decoupling device 118 through which the projected light pattern 70 from the device 310 is decoupled to the environment of the device 310 to be further projected, as with respect to the device 110 already described above.

The array 314 For example, it can be embodied as an array of micro-optics, that is to say in particular as a regular arrangement, in particular a two-dimensional arrangement, of individual micromirrors, which can each be changed individually in their position. For each of the micromirrors of the array 314 There is a respective first position of the respective micromirror, which a forwarding of the laser beam 51 through the pixel which the micromirror forms. For each of the micromirrors, there is also a second micromirror position corresponding to non-passing through the pixel as which the micromirror functions.

The device 310 For example, it may have a light trap and a light trap, the micromirrors of the array 314 are each designed so that they in the respective second micromirror position the incident on them proportion of the laser beam 51 each into the light trap. The light trap is the most complete absorption of the incident laser beam 51 trained and can also be labeled as "beam stop".

Furthermore, it can be provided that the micromirrors of the array 314 in the respective first Micro-mirror position the each incident on it portion of the laser beam 41 for projecting the light pattern 70 on the optional decoupling device 118 the device 310 conduct.

The totality of the pixels that are not yet forwarded for further forwarding results in a corresponding arrangement of white and black pixels which the light pattern to be projected 70 represents.

Alternatively to the formation as an array of micro-optics, the selector device 314 the device 310 also be designed, for example, as a Grating Light Valve. For a grating light valve, each pixel of the selector device 314 formed by a number of individually controllable metal bands. The activation of the metal strips takes place in that selectively individual of the metal strips are deflected by electrostatic fields and thus diffract the laser beams incident on the respective pixel differently.

For example, it may be provided that, if none of the metal bands of a pixel is bent through, the proportion of the laser beam incident on the pixel 51 is reflected to a light trap as described above, so that this pixel is a black pixel in the light pattern to be projected 70 causes. In the case of a deflection of, for example, every other metal strip, it may be provided that the portion of the laser beam incident on the pixel 51 is diffracted such that a new light wave propagates in a direction other than the direction of the light trap, whereby a white pixel of the light pattern to be projected 70 provided. The light wave can, for example, in the direction of the optional output device 118 the device 310 spread.

6 FIG. 12 is a schematic flowchart for explaining a method of projecting a light pattern. FIG 70 according to another embodiment of the present invention. The method according to 6 is with all devices according to the invention 10 ; 110 ; 210 ; 310 feasible and is adaptable according to all modifications and developments described in relation to these devices and vice versa.

In a step S01 becomes a supercontinuum laser device 12 for generating a white laser beam 51 controlled. In a step S02, the generated white laser beam becomes 51 selectively in a number of solid angle ranges for projecting the light pattern 70 directed such that in the beam path of the laser beam generated 51 a diffuser 16 is arranged.

As described above, the control S01 of the supercontinuum laser device 12 in particular, a control for time-dependent generation of the white laser beam 51 include, deciding whether the white laser beam 51 currently generated or not to be generated, for example, from a state of a selector device 14 ; 114 ; 314 can be dependent. Alternatively or additionally, the control S01 may also include controlling a shutter through which the current through the supercontinuum laser device 12 initially generated laser beam 51 is interrupted. In the state of the selector device 14 ; 114 ; 314 For example, as described above, it may be a current deflection mirror position of a micromirror or a plurality of micromirrors, on which or which of the laser beams produced 51 would meet if it were currently produced. The interruption of the generation of the laser beam 51 or interrupting the laser beam 51 By means of a shutter can be carried out in particular for the formation of black pixels, when the selector device as a deflection device 114 is trained. Is the selector device 314 an array, the intensity of each pixel is preferably determined by the modulation of the individual elements of the array.

Although the present invention has been described above with reference to preferred embodiments, it is not limited thereto, but modifiable in a variety of ways. In particular, the invention can be varied or modified in many ways without deviating from the gist of the invention.

Between the supercontinuum laser device 12 and the selector device 14 ; 114 ; 314 can, before or after the lens 16 , For example, be provided at least one filter element to a color temperature or a composition of the spectrum of the laser beam generated 51 to modify. The filter element may be, for example, an acousto-optic modulator (AOM) or an acousto-optical tunable filter (AOTF). Such an acousto-optical modulator consists for example of an optical anisotropic crystal of tellurium dioxide, lithium niobate or quartz, to which a piezoelectric crystal, the so-called "acoustic transducer" is coupled.

By applying a radio frequency of, for example, between 150 and 350 MHz to the piezocrystal, this generates an ultrasonic wave which continues in the optical anisotropic crystal. The ultrasonic wave generates a refractive index grating in the crystal so that the generated laser beam 51 is diffracted in response to the refractive index grating. Depending on the frequency of the Sound wave also changes the wavelength of the diffracted light. An intensity of the diffracted laser light can also be regulated, for example, by the intensity of the sound waves.

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

• US 2010/079836 A1 [0004]

Claims (10)

Contraption ( 10 ; 110 ; 210 ; 310 ) for projecting a light pattern ( 70 ), comprising: a supercontinuum laser device ( 12 ), by means of which a white laser beam ( 51 ) is producible; a selector device ( 14 ; 114 ; 314 ), by means of which the generated white laser beam ( 51 ) for projecting the light pattern ( 70 ) is selectively conductive in a number of solid angle ranges; and a diffuser ( 16 ), which in the beam path of the generated laser beam ( 51 ) before or after the selector device ( 14 ; 114 ; 314 ) is arranged. Contraption ( 110 ) according to claim 1, wherein the selector device acts as a deflection device ( 114 ) is formed, which for deflecting the white laser beam ( 51 ) is trained. Contraption ( 310 ) according to claim 1, wherein the selector means as an array ( 314 ) of selectively the laser beam ( 51 ) is formed forwarding or non-forwarding switchable pixels. Contraption ( 310 ) according to claim 3, wherein the array ( 314 ) is an array of micro-optics. Contraption ( 310 ) according to claim 3, wherein the array ( 314 ) is a Grating Light Valve. Contraption ( 10 ; 110 ) according to one of claims 1 or 2, wherein the white laser beam ( 51 ) from the supercontinuum laser device ( 12 ) to the selector device ( 14 ; 114 ) is conducted in an optical fiber. Contraption ( 10 ; 110 ; 210 ; 310 ) according to one of claims 1 to 6, wherein in the beam path of the white laser beam ( 51 ) a filter device for modifying a color temperature and / or for modifying a spectrum composition of the laser beam ( 51 ) is arranged. Contraption ( 10 ; 110 ; 210 ; 310 ) according to one of claims 1 to 7, wherein the device is designed as a projector. Contraption ( 10 ; 110 ; 210 ; 310 ) according to one of claims 1 to 7, wherein the device is designed as a headlamp, as a tail light or as a direction change indicator. Method for projecting a light pattern ( 70 ), comprising the steps of: controlling (S01) a supercontinuum laser device ( 12 ) for generating a white laser beam ( 51 ); and selectively conducting (S02) the generated white laser beam ( 51 ) into a number of solid angle areas for projecting the light pattern (FIG. 70 ) such that in the beam path of the generated laser beam ( 51 ) a diffuser ( 16 ) is arranged.

Images