EP3671017A1 - Lighting system for a motor vehicle - Google Patents

Abstract

Lighting system (10) for a motor vehicle, the lighting system (10) comprising: - a first and second laser scanner (100, 200) with a first and a second microscanner (120, 220), and - a control device (400) which is set up is to actuate the first and the second microscanner (120, 220), the oscillation behavior of the first and second microscanner (120, 220) at least via the parameters oscillation amplitude AMP, light center of gravity shift LSVP, and offset value OFFSET, which can be changed by the control device (400) are controllable, whereby the control device (400) is set up to receive a time-variable input variable DOA, which represents a target opening angle of the total light distribution (300), and the parameters vibration amplitude AMP, light center shift LSVP, and offset value OFFSET of the first and second Microscanners (120,220) depending on the test result of one of the criteria defines the output variable DOA, namely DOA ≤ (MEMSmax - ALPHA), the parameters of the first microscanner (120) being defined when the criterion is met.

Description

• einen ersten Laserscanner mit zumindest einer Laserlichtquelle, wobei der Laserlichtquelle ein erster Mikroscanner zugeordnet ist, welcher erste Mikroscanner dazu eingerichtet ist, Laserstrahlen der Laserlichtquelle auf ein erstes Lichtkonversionselement zu lenken, wodurch an dem ersten Lichtkonversionselement sichtbares Licht abgestrahlt und ein erstes Lichtbild erzeugt wird, wobei dem ersten Lichtkonversionselement ein optisches Abbildungssystem zugeordnet ist, um das erste Lichtbild vor dem Beleuchtungssystem als erste Teillichtverteilung abzubilden,
• einen zweiten Laserscanner mit zumindest einer Laserlichtquelle, wobei der Laserlichtquelle ein zweiter Mikroscanner zugeordnet ist, welcher zweite Mikroscanner dazu eingerichtet ist, Laserstrahlen der Laserlichtquelle auf ein zweites Lichtkonversionselement zu lenken, wodurch an dem zweiten Lichtkonversionselement sichtbares Licht abgestrahlt und ein zweites Lichtbild erzeugt wird, wobei dem zweiten Lichtkonversionselement ein optisches Abbildungssystem zugeordnet ist, um das zweite Lichtbild vor dem Beleuchtungssystem als zweite Teillichtverteilung abzubilden,

wobei die erste und die zweite Teillichtverteilung abhängig von zumindest drei an den jeweiligen Mikroscannern einstellbaren Parametern veränderbar sind,
wobei die veränderbare erste und zweite Teillichtverteilung eine gemeinsame veränderbare Gesamtlichtverteilung vor dem Beleuchtungssystem erzeugen und sich zumindest teilweise überlappen, wobei die Gesamtlichtverteilung einen Öffnungswinkel aufweist,
und wobei der erste und der zweite Mikroscanner jeweils um eine Achse, welche parallel zueinander angeordnet sind, drehbar gelagert sind, wobei der erste und der zweite Mikroscanner um eine Nulllage mit einer festlegbaren Schwingungsamplitude AMP um die Achse schwingen können, wobei die Schwingungsamplitude durch einen Maximalwert MEMSmax begrenzt ist, wobei die Schwingungsamplitude AMP eine horizontale Breite der jeweils erzeugten Teillichtverteilung bestimmt,
und wobei der erste und der zweite Mikroscanner entlang einer gedachten Linie angeordnet sind, wobei die Nulllage des ersten Mikroscanners um einen ersten Winkel ALPHA und die Nulllage des zweiten Mikroscanners um einen zweiten Winkel ALPHA' zur gedachten Linie geneigt angeordnet sind, wobei der erste und der zweite Winkel invers zueinander sind,
und wobei die erste und die zweite Teillichtverteilung jeweils einen Lichtschwerpunkt aufweisen, der dadurch charakterisiert ist, dass an diesem Punkt die jeweilige Lichtintensität maximal ist, wobei der Lichtschwerpunkt an den jeweiligen Mikroscannern entsprechend einer festlegbaren Lichtschwerpunktverschiebung LSPV verschiebbar ist,
und wobei die Teillichtverteilungen jeweils um einen den jeweiligen Mikroscannern zuführbaren Offsetwert OFFSET verschiebbar sind,

• eine Steuereinrichtung, welche eingerichtet ist, den ersten und den zweiten Mikroscanner anzusteuern, wobei das Schwingungsverhalten des ersten und zweiten Mikroscanners zumindest über die Parameter Schwingungsamplitude AMP, Lichtschwerpunktverschiebung LSVP, und Offsetwert OFFSET, welche durch die Steuereinrichtung veränderbar sind, steuerbar ist.

The invention relates to a lighting system for a motor vehicle, which lighting system comprises the following:

• a first laser scanner with at least one laser light source, the laser light source being assigned a first microscanner, the first microscanner being set up to direct laser beams from the laser light source onto a first light conversion element, as a result of which visible light is emitted at the first light conversion element and a first light image is generated, wherein an optical imaging system is assigned to the first light conversion element in order to image the first light image in front of the illumination system as a first partial light distribution,
• a second laser scanner with at least one laser light source, the laser light source being assigned a second microscanner, the second microscanner being set up to direct laser beams from the laser light source onto a second light conversion element, as a result of which visible light is emitted at the second light conversion element and a second light image is generated, wherein an optical imaging system is assigned to the second light conversion element in order to image the second light image in front of the lighting system as a second partial light distribution,

the first and the second partial light distribution being changeable depending on at least three parameters that can be set on the respective microscanners,
wherein the changeable first and second partial light distribution generate a common changeable total light distribution in front of the lighting system and at least partially overlap, the total light distribution having an aperture angle,
and wherein the first and the second microscanners are each rotatably mounted about an axis which are arranged parallel to one another, the first and the second microscanners being able to oscillate about a zero position with a definable oscillation amplitude AMP, the oscillation amplitude being a maximum value MEMSmax is limited, the oscillation amplitude AMP determining a horizontal width of the partial light distribution generated in each case,
and wherein the first and the second microscanners are arranged along an imaginary line, the zero position of the first microscanner being arranged inclined to the imaginary line by a first angle ALPHA and the zero position of the second microscanner is arranged with respect to the imaginary line, the first and the second angles are inverse to each other,
and wherein the first and the second partial light distribution each have a light center of gravity, which is characterized in that the respective light intensity is maximum at this point, the light center of gravity being displaceable on the respective microscanners in accordance with a definable light center of gravity shift LSPV,
and the partial light distributions can each be shifted by an offset value OFFSET that can be supplied to the respective microscanners,

• a control device which is set up to control the first and the second microscanner, the oscillation behavior of the first and second microscanner being controllable at least via the parameters oscillation amplitude AMP, light center of gravity shift LSVP, and offset value OFFSET, which can be changed by the control device.

The invention further relates to a motor vehicle with at least one lighting system according to the invention.

Laser projection systems can be realized by deflecting a laser beam using so-called microscanners. These microscanners can e.g. as micro-mirrors manufactured in MEMS or MOEMS technology (Micro-Electro-Mechanical Systems or Micro-Opto-Electro-Mechanical Systems), which are only a few millimeters in diameter and can be set into vibration in one or two axial directions.

The vibration amplitude determines the width of the generated light image or partial light distribution.

The speed of vibration, i.e. to vary the angular deflection with a microscanner over time (angular velocity). Since a "slowly" moving light point generates more light in the light conversion element than a fast moving light point, the light distribution can also be influenced in this way.

If two laser scanners are used, the partial light distributions of which together produce an overall light distribution, undesired effects can form with differently adjustable vibration amplitudes, for example two brightness maxima in the overall light distribution.

It is an object of the invention to provide an improved lighting system for motor vehicles.

$$\mathrm{OFFSET}=\mathrm{ALPHA}$$

$$\mathrm{LSPV}=0°$$

und die Parameter des zweiten Mikroscanners wie folgt festlegt sind: $$\begin{array}{c}\mathrm{AMP}=\mathrm{DOA}\hfill \\ \mathrm{OFFSET}=-\mathrm{ALPHA}\end{array}$$

$$\mathrm{LSPV}=0°$$

und wobei bei Nichterfüllung des Kriteriums die Parameter des ersten Mikroscanners wie folgt festgelegt sind: $$\mathrm{AMP}=\left(\mathrm{DOA}+\mathrm{MEMSmax}-\mathrm{ALPHA}\right)/2$$

$$\mathrm{OFFSET}=\mathrm{MEMSmax}-\mathrm{AMP}$$

$$\mathrm{LSPV}=\mathrm{DOA}-\mathrm{AMP}$$

und die Parameter des zweiten Mikroscanners wie folgt festgelegt sind: $$\mathrm{AMP}=\left(\mathrm{DOA}+\mathrm{MEMSmax}-\mathrm{ALPHA}\right)/2$$

$$\mathrm{OFFSET}=-\left(\mathrm{MEMSmax}-\mathrm{AMP}\right)$$

$$\mathrm{LSPV}=-\left(\mathrm{DOA}-\mathrm{AMP}\right)\mathrm{.}$$

This object is achieved in that the control device is set up to receive a time-variable input variable DOA, which represents a target opening angle of the total light distribution, and the parameters vibration amplitude AMP, light center shift LSVP, and offset value OFFSET of the first and second microscanners depending on the Determines the test result of a criterion of the input variable DOA, namely DOA ≤ (MEMSmax - ALPHA), the maximum oscillation amplitude MEMSmax representing the maximum angle around the respective axis, and the parameters of the first microscanner being defined as follows when the criterion is met: $$\mathrm{AMP}=\mathrm{DOA}$$

$$\mathrm{OFFSET}=\mathrm{ALPHA}$$

$$\mathrm{LSPV}=0°$$

and the parameters of the second microscanner are defined as follows: $$\begin{array}{c}\mathrm{AMP}=\mathrm{DOA}\hfill \\ \mathrm{OFFSET}=-\mathrm{ALPHA}\end{array}$$

$$\mathrm{LSPV}=0°$$

and wherein if the criterion is not met, the parameters of the first microscanner are defined as follows: $$\mathrm{AMP}=\left(\mathrm{DOA}+\mathrm{MEMS\; max}-\mathrm{ALPHA}\right)/\mathrm{2nd}$$

$$\mathrm{OFFSET}=\mathrm{MEMS\; max}-\mathrm{AMP}$$

$$\mathrm{LSPV}=\mathrm{DOA}-\mathrm{AMP}$$

and the parameters of the second microscanner are set as follows: $$\mathrm{AMP}=\left(\mathrm{DOA}+\mathrm{MEMS\; max}-\mathrm{ALPHA}\right)/\mathrm{2nd}$$

$$\mathrm{OFFSET}=-\left(\mathrm{MEMS\; max}-\mathrm{AMP}\right)$$

$$\mathrm{LSPV}=-\left(\mathrm{DOA}-\mathrm{AMP}\right)\mathrm{.}$$

Since laser light sources generally emit coherent, monochromatic light or light in a narrow wavelength range, but in a motor vehicle headlight, white mixed light is generally preferred or prescribed by law for the emitted light, so-called light conversion elements for converting essentially monochromatic light into are in the laser light sources assigned white or polychromatic light, whereby “white light” is understood to mean light of such a spectral composition that produces the color impression “white” in humans. This light conversion element is designed, for example, in the form of one or more photoluminescence converters or photoluminescence elements, wherein incident laser beams from the laser light source strike the light conversion element, which as a rule has photoluminescent dyes, and excite this photoluminescent dye for photoluminescence, and thereby light in a wavelength different from the light emitted by the laser device Emits wavelength ranges. The light output of the light conversion element essentially has characteristics of a Lambertian radiator.

In the case of light conversion elements, a distinction is made between reflective and transmissive conversion elements.

The terms "reflective" and "transmissive" refer to the blue portion of the converted white light. In the case of a transmissive structure, the main direction of propagation of the blue light component after passing through the converter volume or conversion element is essentially the same direction as the direction of propagation of the output laser beam. In the case of a reflective structure, the laser beam is reflected or deflected at an interface attributable to the conversion element, so that the blue light component has a different direction of propagation than the laser beam, which is usually designed as a blue laser beam.

In practice, the total light distribution on the road is created by superimposing the partial light distributions, the first laser scanner being located, for example, in a left motor vehicle headlight and the second laser scanner, for example, in a right motor vehicle headlight, whereby the resulting total light distribution is generated by a left and a right motor vehicle headlight of a motor vehicle .

It can advantageously be provided that the laser light sources are dimmable.

In an expedient embodiment it can be provided that - measured from the imaginary line - the first angle ALPHA is 2 ° and the second angle ALPHA 'is -2 °.

It can be provided that the microscanners are designed as quasi-static microscanners.

Microscanners can be obtained one-dimensionally (mirror only moves in one direction) or two-dimensionally (mirror moves in two directions at the same time). Most currently available microscanners work on a resonant drive principle. The MEMS scanners essentially represent mechanical resonant circuits that are excited in their resonance frequency and oscillate sinusoidally. This sinusoidal curve represents a major problem with regard to the utilization of the installed laser power, since the light distribution is always brightest where the microscanner lowest angular velocity reached. With a sinusoidal oscillation, the edge area would appear brightest and the center area or the center of the light distribution darkest, which is why the laser diodes have to be dimmed strongly and therefore only a small percentage (approx. 40%) can be used.

This is remedied by quasi-static microscanners, which can be freely controlled in terms of their angular velocity within certain physical limits (resonance frequencies, ...). It is thus possible to direct a large part of the generated light into the middle or center of the partial light distribution, whereby the utilization of the installed laser power of the laser light sources can be increased up to approx. 90% with typical partial light distributions. Utilization of 100% is not possible because the microscanner changes the direction in the edge area, which means that the mirror “brakes” completely and then accelerates in the opposite direction. During this phase, the laser light sources are deactivated, since otherwise the light intensity there would increase significantly in this reversal area due to the low angular velocity, which is not desired.

It can be provided that the maximum value MEMSmax of the oscillation amplitude of the microscanners is 6 °.

It can further be provided that the control device controls the laser light sources.

The object of the invention is further achieved by a motor vehicle with at least one lighting system.

It can be provided that the time-varying target opening angle of the total light distribution DOA changes depending on the speed of the motor vehicle, the target opening angle DOA being reduced as the speed of the motor vehicle increases.

• Fig. 1 ein beispielhaftes Beleuchtungssystem mit einem ersten Laserscanner, welcher einen ersten Mikroscanner umfasst, und einem zweiten Laserscanner, welcher einen zweiten Mikroscanner umfasst, wobei die Mikroscanner jeweils um einen ersten bzw. einen zweiten Winkel geneigt sind, und wobei die Mikroscanner durch eine Steuereinrichtung veränderbare Parameter aufweisen, wobei der erste Laserscanner eine erste Teillichtverteilung und der zweite Laserscanner eine zweite Teillichtverteilung erzeugt, wobei die erste und die zweite Teillichtverteilung gemeinsam eine Gesamtlichtverteilung erzeugen, welche einen Öffnungswinkel aufweist, wobei die Gesamtlichtverteilung auf einem Messschirm abgebildet wird,
• Fig. 2 eine beispielhafte Kennlinie eines Mikroscanners, wobei eine Schwingungsamplitude AMP gegen die Winkelgeschwindigkeit aufgetragen ist, und wobei die maximale Schwingungsamplitude MEMSmax 6° beträgt,
• Fig. 3A eine Darstellung einer veränderten Schwingungsamplitude AMP der Kennlinie aus Fig. 2;
• Fig. 3B eine Darstellung einer Lichtschwerpunktverschiebung LSVP an der Kennlinie aus Fig. 2;
• Fig. 3C eine Darstellung einer Verschiebung einer Kennlinie durch einen Offsetwert OFFSET;
• Fig. 4A eine Darstellung der ersten bzw. zweiten Teillichtverteilung an dem Messschirm für verschiedene Öffnungswinkel, wobei der erste und der zweite Winkel der jeweiligen Mikroscanner Null beträgt;
• Fig. 4B eine Darstellung der Gesamtlichtverteilung an dem Messschirm, welche sich aus den Teillichtverteilungen aus Fig. 4A zusammensetzt;
• Fig. 5A erste Teillichtverteilungen für bestimmte Öffnungswinkel, wobei der erste Mikroscanner in diesem Beispiel um 2° geneigt ist, wobei für die einzelnen dargestellten Teillichtverteilungen der Lichtschwerpunkt in Richtung Zentrum verschoben sind;
• Fig. 5B zweite Teillichtverteilungen für bestimmte Öffnungswinkel, wobei der zweite Mikroscanner in diesem Beispiel um -2° geneigt ist, wobei für die einzelnen dargestellten Teillichtverteilungen der Lichtschwerpunkt in Richtung Zentrum verschoben sind;
• Fig. 5C Gesamtlichtverteilungen für bestimmte Öffnungswinkel, wobei sich die Gesamtlichtverteilung durch die Teillichtverteilungen aus Fig. 5A und 5B zusammensetzt;
• Fig. 6A erste Teillichtverteilungen für bestimmte Öffnungswinkel, wobei die Parameter des ersten Mikroscanners gemäß des erfindungsgemäßen Kriteriums eingestellt sind;
• Fig. 6B zweite Teillichtverteilungen für bestimmte Öffnungswinkel, wobei die Parameter des zweiten Mikroscanners gemäß des erfindungsgemäßen Kriteriums eingestellt sind;
• Fig. 6C Gesamtlichtverteilungen für bestimmte Öffnungswinkel, wobei sich die Gesamtlichtverteilung durch die Teillichtverteilungen aus Fig. 6A und 6B zusammensetzt;
• Fig. 6D Gesamtlichtverteilungen aus Fig. 6C für bestimmte Öffnungswinkel, wobei an den Rändern der jeweiligen Gesamtlichtverteilungen die entsprechenden Laserlichtquellen gedimmt sind.

The invention is explained in more detail below on the basis of exemplary drawings. Here shows

• Fig. 1 an exemplary lighting system with a first laser scanner, which comprises a first microscanner, and a second laser scanner, which comprises a second microscanner, the microscanners in each case being inclined by a first or a second angle, and wherein the microscanners have parameters that can be changed by a control device , wherein the first laser scanner generates a first partial light distribution and the second laser scanner generates a second partial light distribution, the first and the second partial light distribution together producing an overall light distribution which has an aperture angle, the overall light distribution being imaged on a measuring screen,
• Fig. 2 an exemplary characteristic of a microscanner, an oscillation amplitude AMP being plotted against the angular velocity, and the maximum oscillation amplitude MEMSmax being 6 °,
• Figure 3A a representation of a changed vibration amplitude AMP of the characteristic Fig. 2 ;
• Figure 3B a representation of a light center shift LSVP on the characteristic Fig. 2 ;
• Figure 3C a representation of a shift in a characteristic curve by an offset value OFFSET;
• Figure 4A a representation of the first and second partial light distribution on the measuring screen for different opening angles, the first and the second angle of the respective microscanner being zero;
• Figure 4B a representation of the total light distribution on the measuring screen, which results from the partial light distributions Figure 4A put together;
• Figure 5A first partial light distributions for certain opening angles, the first microscanner in this example being inclined by 2 °, the light center of gravity being shifted towards the center for the individual partial light distributions shown;
• Figure 5B second partial light distributions for specific opening angles, the second microscanner in this example being inclined by -2 °, the light center of gravity being shifted towards the center for the individual partial light distributions shown;
• Figure 5C Total light distributions for certain opening angles, the total light distribution being determined by the partial light distributions 5A and 5B put together;
• Figure 6A first partial light distributions for certain opening angles, the parameters of the first microscanner being set according to the criterion according to the invention;
• Figure 6B second partial light distributions for certain opening angles, the parameters of the second microscanner being set according to the criterion according to the invention;
• Figure 6C Total light distributions for certain opening angles, the total light distribution being determined by the partial light distributions 6A and 6B put together;
• Figure 6D Total light distributions Figure 6C for certain opening angles, the corresponding laser light sources being dimmed at the edges of the respective total light distributions.

Fig. 1 illustrates an exemplary lighting system 10 for a motor vehicle, the illumination system 10 comprises a first laser scanner 100 with at least one laser light source 110, the laser light source, a first micro-scanner is assigned 120 110, which first microscanner 120 is configured to laser beams of the laser light source 110 to a first light conversion element 130 to direct, whereby visible light is emitted from the first light conversion element 130 and a first light image is generated, the first light conversion element 130 being associated with an optical imaging system 140 in order to image the first light image in front of the illumination system 10 as a first partial light distribution 150 .

Furthermore, the lighting system 10 comprises a second laser scanner 200 with at least one laser light source 210 , the laser light source 210 being assigned a second microscanner 220 , which second microscanner 220 is set up to direct laser beams from the laser light source 210 onto a second light conversion element 230 , thereby visible light is emitted from the second light conversion element 230 and a second light image is generated, an optical imaging system 240 being assigned to the second light conversion element 230 in order to image the second light image in front of the illumination system 10 as a second partial light distribution 250 .

In this example, the first and the second microscanners are designed as quasi-static microscanners. Fig. 2 shows a diagram showing the different vibration behavior of a resonant microscanner (in dashed lines) and a quasi-static microscanner (in solid lines).

The resonant microscanners essentially represent mechanical resonant circuits that are excited in their resonant frequency and oscillate sinusoidally. This sinusoidal curve represents a major problem with regard to the utilization of the installed laser power, since the light distribution is always brightest where the microscanner reaches the lowest angular speed. In the case of a sinusoidal oscillation, the edge area would appear the brightest and the center area or the center of the light distribution would be the darkest, which is why the laser diodes must be dimmed heavily and therefore only a small percentage can be used.

This is remedied by quasi-static microscanners, which can be controlled in any angular speed within certain physical limits. It is thus possible to direct a large part of the generated light into the center or center of the partial light distribution, whereby the utilization of the installed laser power of the laser light sources can be increased. It should be noted that the microscanner changes direction in the edge area, which means a complete "braking" of the mirror and a subsequent acceleration in the opposite direction. During this phase, the laser light sources are deactivated, since otherwise the light intensity there would increase significantly in this reversal area due to the low angular velocity, which is not desired.

The first and the second partial light distribution 150 , 250 can be changed as a function of at least three parameters that can be set on the respective microscanners 120 , 220 , namely AMP , LSPV and OFFSET , which in Figures 3A , 3B and 3C are illustrated, the Changeable first and second partial light distributions 150 , 250 generate a common changeable total light distribution 300 in front of the lighting system 10 and at least partially overlap, the total light distribution 300 having an opening angle.

It should be noted that the partial light distributions 150 , 250 and the total light distribution 300 formed in the example shown are depicted in the figures on a measuring screen MS, which is used, for example, in a lighting technology laboratory and is arranged perpendicular to a main emission direction of the laser scanner. A typical distance of such a measuring screen to the device to be measured is 25m according to ECE regulations.

The first and the second microscanners 120 , 220 are each rotatably supported about an axis X1 , X2 , which are arranged parallel to one another, the first and the second microscanners 120 , 220 about a zero position with a definable vibration amplitude AMP about the respective axis X1 , X2 can oscillate, the oscillation amplitude AMP being limited by a maximum value MEMSmax, the oscillation amplitude AMP determining a horizontal width of the partial light distribution 150 , 250 generated in each case. The opening angle of the partial light distribution or the oscillation amplitude AMP of the microscanner can be changed dynamically (in fine gradations), whereby the brightness increases significantly due to the smaller illumination range, for example due to the speed-dependent increase in the illumination range. Figure 3A shows, for example, a vibration amplitude AMP limited to +/- 2 °, it being possible to see that the angular velocity in the region of the zero position of the microscanner is lower than in the characteristic curve from Fig. 2 , which causes an increased light intensity.

The first and the second partial light distribution 150 , 250 each have a light center of gravity, which is characterized in that the respective light intensity is maximum at this point, the light center of gravity being displaceable on the respective microscanners 120 , 220 in accordance with a definable light center of gravity shift LSPV . As already explained above, the light center of gravity results from the deflection area of the microscanner with the lowest angular velocity (the edge areas or reversal points are excluded from this). Figure 3B shows a light center of gravity shift of the characteristic Fig. 2 , whereby the microscanner moves the slowest in the area in which the light center is desired. The partial light distributions 150 , 250 can each be shifted by an offset value OFFSET that can be supplied to the respective microscanners 120 , 220 , the mode of operation of this parameter being explained in FIG Figure 3C is shown. The microscanner parameter OFFSET makes it possible to add an offset value to the angular movement of the respective microscanner. In the diagram Figure 3C is shown an example with an offset value of 2 ° with a vibration amplitude of 4 °. The light center shift LSPV is set to 0 ° here.

The lighting system 10 further comprises a control device 400 , which is set up to control the first and the second microscanners 120 , 220 , the oscillation behavior of the first and second microscanners 120 , 220 at least via the parameters oscillation amplitude AMP , light center shift LSVP , and offset value OFFSET , which are changeable by the control device 400 , is controllable. The control device 400 is also set up to receive a time-variable input variable DOA , which represents a target opening angle of the total light distribution 300 , and sets the parameters of the first and second microscanners 120 , 220 accordingly.

Furthermore, the first and second microscanners 120 , 220 are off Fig. 1 are arranged along an imaginary line, the zero position of the first microscanner 120 being inclined to the imaginary line by a first angle ALPHA and the zero position of the second microscanner 220 by a second angle ALPHA ' , the first and second angles ALPHA , ALPHA' being inverted to each other, for example the first angle ALPHA is 2 ° and the second angle ALPHA ' -2 °.

The Figure 4A 4B show diagrams of the partial light distributions and the resulting total light distributions for different DOA values, the first angle ALPHA and the second angle ALPHA 'being 0 °, and therefore symmetrical partial light distributions occur. A symmetrical light distribution exists if the center position of the partial light distribution also corresponds to the center position of the microscanner deflection.

It should be noted that the diagrams below are made up of 4A to 6D show the relative light output, which is the reciprocal of the angular velocity of each Corresponds to microscanners. The slower the microscanner is moved, the more light output is emitted in the area covered. For this reason, the diagrams shown are always inversely proportional to the angular speed of the respective microscanner.

It should also be noted that all diagrams have been labeled with angle values. This representation is inevitably only correct for a certain projection distance, since the two laser scanners are, for example, one vehicle width apart. For example, this projection distance is 25m, as required in the ECE guidelines. This representation was nevertheless chosen to provide a better understanding.

In the Figure 4A dotted line represents a DOA value of 6 °, which corresponds to a partial light distribution of -6 ° to + 6 ° on the measuring screen and represents the widest partial light distribution. The DOA value is usually shown as a "+" value, for example DOA = 6 °, but this always corresponds to a symmetrical illumination range of +/- 6 °. As the DOA value is reduced, the illumination range is continuously reduced, which means that the light output in the remaining angular range increases significantly. Since both laser scanners in this example are off 4A and 4B cover an identical angular range in the resulting partial light distribution, the light output is doubled by superimposing the two partial light distributions, which in Figure 4B you can see.

An asymmetrical partial light distribution exists if the central position of the partial light distribution does not correspond to the central position or the zero position of the microscanner deflection. This is the case if, for example, the respective microscanners are arranged at an angle to one another. In the example shown below 5A , 5B and 5C the first angle ALPHA is + 2 ° and the second angle ALPHA ' is -2 °. The center position of the partial light distribution is therefore shifted by 2 ° in each case. By rotating the microscanner, a horizontally wider basic light distribution is generated. In order to maintain an area with the maximum light intensity in the center of the overall light distribution, the light centers of the partial light distributions must be shifted back to the center. This is done via the parameter LSPV , which leaves the oscillation amplitude of the microscanner unchanged, however, bring the area in which the microscanner vibrates the slowest closer to the center of the total light distribution or closer to the center on the measuring screen.

Figure 5A shows the first partial light distributions of the first laser scanner and Figure 5B second partial light distributions of the second laser scanner, again showing several partial light distributions with different vibration amplitudes or for different opening angles of the total light distribution (DOA value). In the figure it can be seen that the light center with the different DOA values must always be adjusted so that the light center remains in the middle of the total light distribution. This is not possible in practice at very low DOA values, since the light center of gravity in conventional microscanner systems is limited to a certain percentage of the oscillation amplitude of the microscanners.

It can be seen that the light centers for the DOA values of 4 and 4.5 ° can no longer be moved to the center. As already mentioned, this is due to the fact that the center of gravity can only be shifted up to a maximum of approx. 80% of the vibration amplitude.

Figure 5C shows an overlay of the partial light distributions 5A and 5B , where it can be seen that effects occur which are not desired, such as, for example, the double light centers at DOA = 8 °. Furthermore, when the DOA values are reduced, not only the outer edges or boundaries move inwards, but both boundaries of the first and second microscanners. As a result, there is a change in DOA values to "moving" brightness jumps within the light distribution.

$$\mathbf{OFFSET}=\mathbf{ALPHA}$$

$$\mathbf{LSPV}=0°$$

und die Parameter des zweiten Mikroscanners 220 wie folgt festlegt sind: $$\mathbf{AMP}=\mathbf{DOA}$$

$$\mathbf{OFFSET}=-\mathbf{ALPHA}$$

$$\mathbf{LSPV}=0°$$

und wobei bei Nichterfüllung des Kriteriums die Parameter des ersten Mikroscanners 120 wie folgt festgelegt sind: $$\mathbf{AMP}=\left(\mathbf{DOA}+\mathbf{MEMSmax}-\mathbf{ALPHA}\right)/2$$

$$\mathbf{OFFSET}=\mathbf{MEMSmax}-\mathbf{AMP}$$

$$\mathbf{LSPV}=\mathbf{DOA}-\mathbf{AMP}$$

und die Parameter des zweiten Mikroscanners 220 wie folgt festgelegt sind: $$\mathbf{AMP}=\left(\mathbf{DOA}+\mathbf{MEMSmax}-\mathbf{ALPHA}\right)/2$$

$$\mathbf{OFFSET}=-\left(\mathbf{MEMSmax}-\mathbf{AMP}\right)$$

$$\mathbf{LSPV}=-\left(\mathbf{DOA}-\mathbf{AMP}\right)\mathbf{.}$$

In order to minimize or completely avoid these undesirable effects, the control device 400 , which controls the first and the second microscanners 120 , 220 , is set up to receive an input variable DOA which changes over time and which represents a desired opening angle of the total light distribution 300 , and the parameters oscillation amplitude AMP , light center shift LSPV and offset value OFFSET of the first and second microscanners 120 , 220 depending on the test result of a criterion of the input variable DOA , namely DOA ≤ ( MEMSmax - ALPHA ), the maximum oscillation amplitude MEMSmax represents the maximum angle about the respective axis X1 , X2 , and the parameters of the first microscanner 120 are defined as follows when the criterion is met: $$\mathbf{AMP}=\mathbf{DOA}$$

$$\mathbf{OFFSET}=\mathbf{ALPHA}$$

$$\mathbf{LSPV}=0°$$

and the parameters of the second microscanner 220 are defined as follows: $$\mathbf{AMP}=\mathbf{DOA}$$

$$\mathbf{OFFSET}=-\mathbf{ALPHA}$$

$$\mathbf{LSPV}=0°$$

and wherein if the criterion is not met, the parameters of the first microscanner 120 are defined as follows: $$\mathbf{AMP}=\left(\mathbf{DOA}+\mathbf{MEMS\; max}-\mathbf{ALPHA}\right)/\mathrm{2nd}$$

$$\mathbf{OFFSET}=\mathbf{MEMS\; max}-\mathbf{AMP}$$

$$\mathbf{LSPV}=\mathbf{DOA}-\mathbf{AMP}$$

and the parameters of the second microscanner 220 are set as follows: $$\mathbf{AMP}=\left(\mathbf{DOA}+\mathbf{MEMS\; max}-\mathbf{ALPHA}\right)/\mathrm{2nd}$$

$$\mathbf{OFFSET}=-\left(\mathbf{MEMS\; max}-\mathbf{AMP}\right)$$

$$\mathbf{LSPV}=-\left(\mathbf{DOA}-\mathbf{AMP}\right)\mathbf{.}$$

In 6A and 6B the first and the second partial light distribution can be seen, the above-mentioned algorithm for setting the parameters being used by the control device 400 .

In Figure 6A it can be seen that at high DOA values only the left light-dark limit of the partial light distribution is shifted inwards. At the DOA value of 4 ° (in this example) there is a transition to a symmetrical partial light distribution, as a result of which both the left and right cut-off lines move evenly inwards. Figure 6B basically shows the first partial light distributions Figure 6A just mirrored.

Figure 6C shows the overlays of the partial light distributions 6A and 6B for different DOA values.

In practice, the brightness curve of the partial light distributions or of the basic light distributions that can be generated is not generated solely via the angular speed of the microscanner, since this cannot generate any desired speed curves, but additional dimming of the laser light sources is carried out. This is particularly necessary in the edge area, since the microscanner has a limited maximum speed. In the reverse areas, which cannot be seen in the diagrams, the laser light source is completely switched off or deactivated. The control device 400 is set up to control the laser light sources accordingly. The curves shown above can be dimmed by additional dimming of the laser light sources in the "left" and "right" edge areas, such as in Figure 6D in the sense of a smooth transition from light to dark.

Claims (8)

Lighting system (10) for a motor vehicle, which lighting system (10) comprises: - A first laser scanner (100) with at least one laser light source (110), the laser light source (110) being assigned a first microscanner (120), which first microscanner (120) is set up to laser beams of the laser light source (110) onto a first light conversion element (130), whereby visible light is emitted from the first light conversion element (130) and a first light image is generated, the first light conversion element (130) being associated with an optical imaging system (140) in order to direct the first light image in front of the lighting system (10) to be depicted as the first partial light distribution (150), - A second laser scanner (200) with at least one laser light source (210), the laser light source (210) being assigned a second microscanner (220), which second microscanner (220) is set up to laser beams of the laser light source (210) onto a second light conversion element (230), whereby visible light is emitted at the second light conversion element (230) and a second light image is generated, an optical imaging system (240) being assigned to the second light conversion element (230) in order to direct the second light image in front of the lighting system (10) depicted as a second partial light distribution (250), the first and the second partial light distribution (150, 250) being changeable depending on at least three parameters (AMP, LSVP, OFFSET) that can be set on the respective microscanners (120, 220),
wherein the variable first and second partial light distribution (150, 250) produce a common variable total light distribution (300) in front of the lighting system (10) and at least partially overlap, the total light distribution (300) having an aperture angle,
and wherein the first and the second microscanners (120, 220) are each rotatably mounted about an axis (X1, X2) which are arranged parallel to one another, the first and the second microscanners (120, 220) can oscillate around a zero position with a definable oscillation amplitude AMP about the respective axis (X1, X2), the oscillation amplitude AMP being limited by a maximum value MEMSmax, the oscillation amplitude AMP being a horizontal width of the partial light distribution generated in each case ( 150, 250) determines
and wherein the first and second microscanners (120, 220) are arranged along an imaginary line, the zero position of the first microscanner (120) by a first angle ALPHA and the zero position of the second microscanner (220) by a second angle ALPHA ' imaginary line are arranged inclined, the first and second angles ALPHA, ALPHA 'being inverse to one another,
and wherein the first and the second partial light distribution (150, 250) each have a light center of gravity, which is characterized in that the respective light intensity is maximum at this point, the light center of gravity on the respective microscanners (120, 220) in accordance with a definable light center of gravity shift LSPV is movable
and the partial light distributions (150, 250) can each be shifted by an offset value OFFSET which can be supplied to the respective microscanners (120, 220), - A control device (400) which is set up to control the first and the second microscanner (120, 220), the oscillation behavior of the first and second microscanner (120, 220) at least via the parameters oscillation amplitude AMP, light center shift LSVP, and offset value OFFSET which can be changed by the control device (400), can be controlled, characterized in that
the control device (400) is set up to receive a time-variable input variable DOA, which represents a target opening angle of the total light distribution (300), and the parameters of vibration amplitude AMP, light center shift LSVP, and offset value OFFSET of the first and second microscanners (120, 220) are dependent from the test result of a criterion of Specifies input variable DOA, namely DOA ≤ (MEMSmax - ALPHA), the maximum vibration amplitude MEMSmax representing the maximum angle around the respective axis (X1, X2), and the parameters of the first microscanner (120) being defined as follows when the criterion is met : $$\mathrm{AMP}=\mathrm{DOA}$$

$$\mathrm{OFFSET}=\mathrm{ALPHA}$$

$$\mathrm{LSPV}=0°$$

and the parameters of the second microscanner (220) are defined as follows: $$\mathrm{AMP}=\mathrm{DOA}$$

$$\mathrm{OFFSET}=-\mathrm{ALPHA}$$

$$\mathrm{LSPV}=0°$$

and wherein if the criterion is not met, the parameters of the first microscanner (120) are defined as follows: $$\mathrm{AMP}=\left(\mathrm{DOA}+\mathrm{MEMS\; max}-\mathrm{ALPHA}\right)/\mathrm{2nd}$$

$$\mathrm{OFFSET}=\mathrm{MEMS\; max}-\mathrm{AMP}$$

$$\mathrm{LSPV}=\mathrm{DOA}-\mathrm{AMP}$$

and the parameters of the second microscanner (220) are defined as follows: $$\mathrm{AMP}=\left(\mathrm{DOA}+\mathrm{MEMS\; max}-\mathrm{ALPHA}\right)/\mathrm{2nd}$$

$$\mathrm{OFFSET}=-\left(\mathrm{MEMS\; max}-\mathrm{AMP}\right)$$

$$\mathrm{LSPV}=-\left(\mathrm{DOA}-\mathrm{AMP}\right)\mathrm{.}$$

Lighting system according to claim 1, characterized in that the laser light sources (110, 210) are dimmable. Lighting system according to claim 1 or 2, characterized in that measured from the imaginary line, the first angle ALPHA is 2 ° and the second angle ALPHA '-2 °. Illumination system according to one of Claims 1 to 3, characterized in that the microscanners (120, 220) are designed as quasi-static microscanners. Illumination system according to one of Claims 1 to 4, characterized in that the maximum value MEMSmax of the oscillation amplitude AMP of the microscanners (120, 220) is 6 °. Lighting system according to one of claims 1 to 5, characterized in that the control device (400) controls the laser light sources (110, 210). Motor vehicle with at least one lighting system (10) according to one of Claims 1 to 6. Motor vehicle according to claim 7, characterized in that the time-varying target opening angle of the total light distribution DOA changes depending on the speed of the motor vehicle, the target opening angle DOA being reduced as the speed of the motor vehicle increases.

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