Apparatus and headlight

Abstract

In one embodiment, an apparatus may include a light source. The apparatus also includes a measuring laser, such as a semiconductor laser. The measuring laser is configured to generate pulses with a maximum pulse duration of 10 ns. A wavelength of maximum intensity of the measuring laser radiation generated by the measuring laser ranges from 400 nm to 485 nm inclusive. The measuring laser radiation is used for distance measurement by means of LIDAR, for example in a car headlight.

Claims

1. An apparatus comprising: a light source; at least one measuring laser; wherein the measuring laser is a semiconductor laser and is configured to generate pulses with a pulse duration of at most 10 ns; a wavelength of maximum intensity of a measuring laser radiation generated by the measuring laser ranges from 400 nm to 485 nm inclusive.

2. The apparatus according to claim 1, wherein: the light source is configured to produce white light; an illumination range of the light source is at least 25 m; further comprising at least one sensor and an electronic unit; wherein the sensor is configured to detect a portion of the measuring laser radiation reflected outside the apparatus at an external object with a time resolution of at most 5 ns, wherein the electronic unit is configured to determine a transit time of the reflected and detected portion of the measuring laser radiation; and wherein the pulse duration is at most 5 ns.

3. The apparatus according to claim 2, wherein: the light source comprises at least one phosphor; the phosphor is configured to be excited by a primary light source; wherein the primary light source is configured to produce blue light as primary radiation, wherein the phosphor is configured to produce secondary radiation; the light source is configured to emit a mixed radiation composed of the primary radiation and the secondary radiation.

4. The apparatus according to claim 3, wherein: the primary light source is formed by the measuring laser; and the measuring laser radiation is a portion of the primary radiation transmitted through the phosphor.

5. The apparatus according to claim 4, wherein: the measuring laser radiation and the mixed radiation illuminate the same solid angle range; and the sensor is configured for spatially resolved detection of the reflected measuring laser radiation.

6. The apparatus according to claim 3, wherein: the primary light source is a semiconductor laser configured to emit blue light; the primary light source is different from the measuring laser; and the measuring laser radiation is guided past the phosphor.

7. The apparatus according to claim 6, wherein: the primary light source and the measuring laser are configured to emit light of the same maximum wavelength with a tolerance of at most 10 nm; the mixed radiation is colored light; and the mixed radiation and the measuring laser radiation are white light.

8. The apparatus according to claim 6, wherein: the apparatus comprises an imaging optics; and the imaging optics are arranged downstream of the primary light source and the measuring laser.

9. The apparatus according to claim 1, wherein: the apparatus comprises at least one imaging optics; and the imaging optics is configured to image the measuring laser radiation in a pattern and/or to scan with the measuring laser radiation.

10. The apparatus according to claim 9, wherein: the imaging optics are inseparably connected to the measuring laser; and the imaging optics comprises a lens, a reflector, a diffractive optical element, a meta-lens, a multi-lens field, and/or a diffuser.

11. The apparatus according to claim 1, further comprising an infrared laser; wherein the infrared laser is a semiconductor laser and is configured to generate pulses with a pulse duration of at most 10 ns; a maximum intensity wavelength of infrared radiation produced by the infrared laser ranges from 0.7 μm to 3 μm inclusive; and a pulse emission of the infrared laser is configured to be synchronized with the measuring laser.

12. The apparatus according to claim 11, wherein: the infrared laser and the measuring laser have at least one optical element arranged downstream; and the infrared laser is configured to be operated when the measuring laser is switched off.

13. The apparatus according to claim 11, wherein: the infrared laser and the electronic unit are configured as a safety circuit for the measuring laser; and the measuring laser is operated when it has been determined that no persons are located in an illumination area of the measuring laser.

14. The apparatus according to claim 1, wherein: the sensor is a Si photodiode, a Si photodiode array, or a CMOS camera; and the sensor is configured to have at least two different spectral ranges.

15. The apparatus according to claim 1, wherein: the measuring laser is an edge-emitting flip chip, a capacitor is electrically connected in parallel with a series connection of the measuring laser and a switching element; and the measuring laser, the capacitor, the switching element, or combinations thereof are mounted on a common carrier in the absence of bonding wires.

16. The apparatus according to claim 1, wherein the apparatus is a motor vehicle, a drone, a robot, an actuator, or a tool.

17. The apparatus according to claim 1, further comprising an infrared laser, and wherein a maximum intensity wavelength of infrared radiation produced by the infrared laser ranges from 0.7 μm to 3 μm inclusive.

18. The apparatus according to claim 1, further comprising an infrared laser, and wherein a pulse emission of the infrared laser is configured to be synchronized with the measuring laser.

19. A headlight comprising: a light source; and a measuring laser; wherein: the light source comprises at least one phosphor; the phosphor is configured to be excited by a primary light source; wherein the primary light source is configured to produce blue light as primary radiation, wherein the phosphor is configured to produce secondary radiation; the primary light source is a light emitting diode or a semiconductor laser; the light source is configured to emit a mixed radiation comprising the primary radiation and the secondary radiation; the measuring laser is a semiconductor laser and is configured to generate pulses with a pulse duration of at most 10 ns; a wavelength of maximum intensity of a measuring laser radiation generated by the measuring laser ranging from 400 nm to 485 nm inclusive; and an illumination range of the light source is at least 25 m.

20. The headlight according to claim 19, wherein the primary light source is formed by the measuring laser; the measuring laser radiation is a portion of the primary radiation transmitted through the phosphor; and the measuring laser radiation and the secondary radiation are white light.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The accompanying drawings serve to afford an understanding of embodiments. The drawings illustrate embodiments and together with the description serve to elucidate same. Further embodiments and numerous advantages from among those intended are evident directly from the following detailed description. The elements and structures shown in the drawings are not necessarily illustrated in a manner true to scale with respect to one another. Identical reference signs refer to identical or mutually corresponding elements and structures.

(2) FIGS. 1 to 9 show schematic sectional views of exemplary embodiments of the apparatuses described here and the headlights described here,

(3) FIGS. 10 to 12 show schematic diagrams of exemplary embodiments of the apparatuses described here,

(4) FIGS. 13 to 17 show schematic electrical circuit diagrams for measuring lasers for apparatuses and headlights described here

(5) FIG. 18 shows a schematic top view of a circuit arrangement of a semiconductor laser for the apparatuses and headlights described here, and

(6) FIGS. 19 to 25 in Figure parts A show schematic sectional views and in Figure parts B schematic top views of circuit arrangements of semiconductor lasers for apparatus and headlights described here.

DETAILED DESCRIPTION

(7) FIG. 1 shows an exemplary embodiment of an apparatus 1. The apparatus 1 is a car headlight 10.

(8) The apparatus 1 comprises a light source 2. The light source 2 emits white light. A measuring laser 3 is integrated in the light source 2. The measuring laser 3 emits a measuring laser radiation M during operation. The measuring laser radiation M is a pulsed laser radiation with a pulse duration of 10 ns at most. The measuring laser radiation M can be divided into individual pulses or into pulse trains, also known as bursts.

(9) Furthermore, the apparatus 1 includes a sensor 4, which detects 6 reflected measuring laser beams M from an object. The object 6 is, for example, another traffic participant.

(10) Furthermore, the apparatus 1 comprises an electronic unit 5, which controls the measuring laser 3 and the sensor 4 as well as optionally the light source 2. The electronic unit 5 contains, for example, one or more integrated circuits and may also comprise memory units as well as data inputs and data outputs.

(11) Via the electronic unit 5, the signals from sensor 4 are evaluated. By measuring the run time of the measuring laser radiation M to the object 6 and back from the object 6, the distance of the apparatus 1 to the object 6 is determined in a time-resolved manner.

(12) The components 2, 3, 4, 5 can be integrated in a common housing 11. Since all components 2, 3, 4, 5 are located in the housing 11, the apparatus 1, especially the headlight 10, can be handled as a single assembly or as a module. This makes it easier to install or replace headlight 10.

(13) In the exemplary embodiment in FIG. 2, apparatus 1 is also designed as headlight 10, especially as a car headlight. Light source 2 is made up of several primary light sources 22, each of which is followed by a phosphor 21. A primary radiation P is emitted by the primary light sources 22, which is partially converted into a secondary radiation S by the phosphors 21. Thus a mixed radiation is emitted, which is composed of the primary radiation P and the secondary radiation S.

(14) One of the primary light sources 22 simultaneously serves as measuring laser 3, and one of the phosphors 21 is located downstream of the measuring laser 3. The measuring laser radiation M is blue light which is emitted as a short light pulse, for example as an approximately rectangular light pulse. The secondary radiation S is emitted after excitation by the measuring laser radiation M, but with a slight time delay and over a longer period of time. This is symbolized by the time courses of the radiations M, P, S to the measuring laser 3 in FIG. 2.

(15) The primary light sources 22, which are not used as measuring laser 3, may have a different structure than the measuring laser 3 itself. Deviating from the illustration in FIG. 2, there may also be only one primary light source 22 which is also used as measuring laser 3, or there may be measuring laser 3 and only one further primary light source 22.

(16) If the measuring laser 3 and at least one further primary light source 22 are present, the measuring laser 3 emits the measuring laser radiation M in a time window in which the other primary light sources 22 are switched off. If the measuring laser 3 emits the measuring laser radiation M only with a comparatively low repetition rate, for example 50 Hz, so that a measuring time for the measuring laser radiation M is only a small time fraction of, for example, a maximum of 50×1 ms per 1 s, the measuring laser 3 can emit continuously in the remaining time fraction, especially with a low optical output power. The same applies to all other exemplary embodiments.

(17) The housing 11 terminates with a single imaging optics 7, which is arranged downstream of all light sources 22, 3 in common. The imaging optics 7 define an illumination range, also known as the field of view.

(18) The apparatus 1, as shown in FIG. 2, for example, is a low beam or a high beam in a motor vehicle. The headlight can also be an adaptive front light, or AFS for short. The same is possible for all other exemplary embodiments.

(19) The apparatus 1 of FIG. 2 can optionally include the sensor 4 and the electronic unit 5, not shown. The components 4, 5 can be mounted outside or also inside the housing 11. Thus, it is possible that the headlight 10 itself does not include the sensor 4 and optionally does not include the electronic unit 5.

(20) FIG. 3 illustrates that the imaging optics are divided into two optics 7a, 7b. Optics 7a are used for imaging the primary light sources 22, each of which is followed by the phosphor 21. The imaging optics 7b serves as the sole optics for the measuring laser 3. In contrast to the illustration in FIG. 3, it is possible that the imaging optics 7a is arranged downstream of all light sources 22, 3 and the imaging optics 7b.

(21) For the rest, the exemplary embodiment in FIG. 3 corresponds to that in FIG. 2.

(22) The optics 7, 7a, 7b can each be formed by refractive and/or reflective optics.

(23) In the exemplary embodiment shown in FIG. 4, no phosphor 21 is arranged downstream of the measuring laser 3. The measuring laser radiation M shines past the phosphors 21. Thus the measuring laser 3 is not part of the light source 2, but independent of the light source 2. As in FIG. 2, the imaging optics 7 can be arranged downstream of the light sources 22, 3 together.

(24) The mixed radiation P, S together with the measuring laser radiation M forms white light.

(25) FIG. 5 illustrates that a separate optical system 7b is provided for the measuring laser 3. Optics 7b is a lens, such as a converging lens, or a movable mirror, for example a MEMS mirror.

(26) For the rest, the exemplary embodiments of FIGS. 4 and 5 correspond to those of FIGS. 2 and 3.

(27) FIG. 6 illustrates that the apparatus 1 and/or the headlight 10 additionally include an infrared laser 8. In addition, separate optics 7a, 7b, 7c, 7d may be provided for each of the radiation-emitting components 2, 3, 8 and for the sensor 4.

(28) FIG. 7 illustrates that the common optics 7a is arranged downstream of the radiation-emitting components 2, 3, 8. The sensor 4 is optically preceded by the imaging optics 7b.

(29) For the rest, the explanations given in FIGS. 6 and 7 with regard to the light sources 2, 3, apply to FIG. 1 and FIGS. 2 to 5.

(30) FIGS. 8 and 9 illustrate the detection of reflected radiation. Radiation M, P, S are emitted by headlight 10 and partially reflected by object 6. The sensor 4 of the apparatus 1, which is arranged separately from the headlight 10, is preceded by the imaging optics 7 and a filter 9.

(31) Only the measuring laser radiation M passes through the filter 9 to the sensor 4. The radiations P, S are filtered out. Thus it is possible that the primary radiation P comprises a different wavelength than the measuring laser radiation M to allow spectral filtering. Alternatively, the measuring laser radiation M and the primary radiation P may comprise the same wavelength and a filtering is performed in the time domain. This is especially true if the primary light source is used as a measuring laser, see FIGS. 2 and 3.

(32) According to FIG. 9 the headlight 10 emits the infrared radiation IR and the measuring laser radiation M. The e.g. white light of the light source 2 is not drawn.

(33) The sensor 4 is pixelated and locally sensitive for the infrared radiation IR and the measuring laser radiation M by means of the filters 8a, 8b. A sensitivity separation is thus performed by the filters 8a, 8b.

(34) According to FIGS. 8 and 9 a spatial resolution with respect to the measuring laser radiation M and optionally the infrared radiation R is achieved by the sensor 4. Sensor 4 is pixelated accordingly to ensure a spatial assignment of the locally detected radiation M, IR.

(35) Such pixelated sensors 4 and optionally the use of the additional infrared laser 8 is also possible in all other exemplary embodiments.

(36) The sensor 4 is for example a silicon photodiode, a silicon photodiode array or a CMOS Time of Flight camera.

(37) Deviating from the illustration in FIG. 9, it is possible that each of the filters 8a, 8b is assigned its own imaging optics. In this case there is no common imaging optics 7, which is illustrated in FIG. 9.

(38) FIG. 10 illustrates that apparatus 1 is a car. The apparatus 1 has several of the headlights 10 with the light sources 2, 3 and optionally with the infrared laser 8. The sensor 4 can be arranged separately from the headlights 10 or it can be a part of the headlight 10, different from FIG. 10.

(39) According to FIG. 11, the apparatus 1 is a gripper arm or a robot arm. The headlight 10 and optionally the sensor 4 can be mounted on a tip of the gripper arm.

(40) In the exemplary embodiment shown in FIG. 12, apparatus 1 is a flying drone. The apparatus 1 includes the headlight 10 and optionally the sensor 4, which can also be integrated in the headlight 10, in contrast to the illustration in FIG. 12.

(41) FIGS. 13 to 17 show exemplary circuit diagrams for the control of the measuring laser 3. In FIGS. 13 to 17, one capacitor 31 is electrically connected in parallel to each semiconductor laser diode 30 of measuring laser 3. Optionally, there can be another capacitor 31 electrically connected in series with the laser diode 30.

(42) Furthermore, a switching element 32 is connected in series with the laser diode 30. The switching element 32 is a field effect transistor, FET for short, especially based on SiC, GaN or Si. If the switching element 32 is connected to a supply voltage V, it is for example a p-MOS-FET, see FIGS. 13 and 15. If the switching element 32 is connected to an earth connection line GND, the switching element 32 is an n-MOS-FET, see FIGS. 14 and 16.

(43) FIGS. 15 and 16 illustrate that a protective diode 33 can be connected antiparallel to the laser diode 30. The protection diode 33 is a diode for protection against damage caused by electrostatic discharge, in short ESD diode.

(44) FIG. 17 illustrates that a parallel connected switching element 32b may be present in addition to the switching element 32a connected in series with the laser diode 30. The switching element 32b can be used to quickly switch off the laser diode 30 and thus shorten the pulse duration.

(45) A conductor loop within the circuit arrangement, as shown in FIGS. 13 to 17, is as small as possible so that an area and volume are as small as possible. This allows low inductances to be achieved to ensure short switching and control times. In a non-limiting embodiment, components 30, 31, 32 and optionally 33 are integrated in a common housing, not drawn.

(46) FIG. 18 illustrates that a carrier 34 is provided for measuring laser 3, on which the laser diode 30 and the capacitor 31 are mounted on a common contact surface 35. The switching element 32 and optionally the protective diode 33 are integrated in the carrier 34. The switching element 32 is designed as FET. An electrical connection of the laser diode 30 and the capacitor 31 is made via several bonding wires 37 each to ensure low inductances.

(47) The capacitor 31 is for example a silicon chip capacitor or a capacitor of type 0102 or similar. To control the switching element 32 electrical contact surfaces 35, d, and 35, g as well as 35, s, GND for drain, gate as well as source=GND can be provided. On an underside of carrier 34, which is not drawn, corresponding contact surfaces can be present.

(48) It is possible that on a facet of the laser diode 30 there is a facet encapsulation 36, which can be lenticular. The facet encapsulation 36 is only schematically drawn in a simplified form. For example, the facet encapsulation 36 is designed as described in document DE 10 2017 123 798 A1. The disclosure content of this document is included hereby by reference.

(49) The carrier 34 is a substrate like a printed circuit board, PCB for short, or a metal core board. The carrier 34 can also be a ceramic substrate with conductor tracks or an embedded leadframe. Furthermore, carrier 34 can be a Si submount.

(50) As an alternative to the illustration in FIG. 18, it is possible to use a wire-bond-free contact in order to further reduce electrical inductances of the leads.

(51) FIGS. 19 to 25 illustrate further exemplary embodiments of circuit arrangements for measuring laser 3, analogous to FIG. 18, with the circuitry following the circuit diagram shown in FIG. 13. In the same way, however, the circuit diagrams in FIGS. 14 to 17 can be used. In Figure parts A, as far as they are available in the corresponding Figure parts B at all, bonding wires are not drawn, nor are the contact surfaces. It is possible that the measuring laser 3 consists only of the laser diode 30 or that it comprises the carrier 34 and all components carried by it.

(52) According to FIG. 19, carrier 34 is a substrate with contact surfaces 35, for example a printed circuit board, or PCB for short, a ceramic carrier or a lead frame. The switching element 32 is a FET and/or an ASIC and is based on Si, GaN or SiC. A local hermetic encapsulation of the laser diode 30 can be achieved via the facet encapsulation 36.

(53) The contact surface 35, g for the gate connection as well as the contact surface 35, GND, s for the source connection and the contact surface 35, V for the supply voltage connection are connected via electrical contact surfaces 38 with corresponding contact surfaces on a carrier underside, not drawn. The laser diode 30 is connected via several bonding wires 37 to the contact surface 35, d for the drain connection of the switching element 32. The capacitor 31 is located on the contact surface 35, V and is also connected via several bonding wires 37 to the contact surface 35, GND, s.

(54) Contrary to FIG. 19, in FIG. 20 the capacitor 31 is a flip chip, so that the capacitor 31 is directly connected to the contact pads 35, GND, s and 35, V without bonding wires. Contrary to FIG. 19, FIG. 21 shows the contact surface 35, d in top view between the contact surfaces 35, g and 35, GND, s. The contact surface 35, d is located on a side of switching element 32 facing away from carrier 34.

(55) The arrangement of FIG. 22 corresponds to a combination of FIGS. 20 and 21.

(56) In the exemplary embodiment of FIG. 23, the capacitor 31 is integrated in the carrier 34. The carrier 34 is designed as a multilayer ceramic. The capacitor 31 is electrically connected via vias 38. For the rest, the example in FIG. 23 corresponds to that in FIG. 19.

(57) According to FIG. 24, the switching element 32 is also integrated in carrier 34 and connected via the vias 38. Only contact surfaces 35, d and 35, V are located on the upper side of carrier 34. The remaining, undrawn contact surfaces are located on the underside of carrier 34.

(58) In the exemplary embodiment of FIG. 25 the laser diode 30 is contacted without any bonding wire. For this purpose, a via 38 is created in and/or at a semiconductor layer sequence of the laser diode 30, so that the semiconductor layer sequence is electrically connected on two sides. Otherwise, the explanations in connection with FIG. 24 apply.

(59) Unless otherwise indicated, the components shown in the Figures follow each other directly in the order given. Layers not touching each other in the Figures are spaced apart. If lines are drawn parallel to each other, the corresponding surfaces are aligned parallel to each other. Likewise, unless otherwise indicated, the relative positions of the drawn components to each other are correctly shown in the Figures.

(60) This patent application claims the priority of the German patent application 10 2018 113 711.7, the disclosure content of which is hereby incorporated by reference.

(61) The invention described here is not limited by the description using the exemplary embodiments. Rather, the invention comprises each new feature as well as each combination of features, which in particular includes each combination of features in the claims, even if this feature or combination itself is not explicitly specified in the claims or exemplary embodiments.

LIST OF REFERENCE SIGNS

(62) 1 apparatus 10 headlight 11 housing 2 light source 21 phosphor 22 primary light source 3 measuring laser 30 laser diode 31 capacitor 32 switching element 33 protective diode 34 carrier 35 contact surface 36 facet encapsulation/lens 37 bonding wire 38 via 4 sensor 5 electronic unit
6 reflecting object 7 imaging optics 8 infrared laser 9 filter d drain connection g gate connection GND earth connection IR infrared radiation M measuring laser radiation P primary radiation S secondary radiation s source connection V supply voltage