Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60Q—ARRANGEMENT OF SIGNALLING OR LIGHTING DEVICES, THE MOUNTING OR SUPPORTING THEREOF OR CIRCUITS THEREFOR, FOR VEHICLES IN GENERAL
  • B60Q11/00—Arrangement of monitoring devices for devices provided for in groups B60Q1/00 - B60Q9/00
  • B60Q11/005—Arrangement of monitoring devices for devices provided for in groups B60Q1/00 - B60Q9/00 for lighting devices, e.g. indicating if lamps are burning or not
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F21—LIGHTING
  • F21S—NON-PORTABLE LIGHTING DEVICES; SYSTEMS THEREOF; VEHICLE LIGHTING DEVICES SPECIALLY ADAPTED FOR VEHICLE EXTERIORS
  • F21S41/00—Illuminating devices specially adapted for vehicle exteriors, e.g. headlamps
  • F21S41/10—Illuminating devices specially adapted for vehicle exteriors, e.g. headlamps characterised by the light source
  • F21S41/12—Illuminating devices specially adapted for vehicle exteriors, e.g. headlamps characterised by the light source characterised by the type of emitted light
  • F21S41/125—Coloured light
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F21—LIGHTING
  • F21S—NON-PORTABLE LIGHTING DEVICES; SYSTEMS THEREOF; VEHICLE LIGHTING DEVICES SPECIALLY ADAPTED FOR VEHICLE EXTERIORS
  • F21S41/00—Illuminating devices specially adapted for vehicle exteriors, e.g. headlamps
  • F21S41/60—Illuminating devices specially adapted for vehicle exteriors, e.g. headlamps characterised by a variable light distribution
  • F21S41/67—Illuminating devices specially adapted for vehicle exteriors, e.g. headlamps characterised by a variable light distribution by acting on reflectors
  • F21S41/675—Illuminating devices specially adapted for vehicle exteriors, e.g. headlamps characterised by a variable light distribution by acting on reflectors by moving reflectors

Definitions

• Lighting device for a motor vehicle in particular headlights
• the present invention relates to a lighting device for a motor vehicle, in particular a headlight, according to the preamble of claim 1 and a method for operating such a lighting device.
• Headlamps with a digital micromirror device or a DMD are known.
• a multiplicity of mirror elements can occupy at least one first position and at least one second position, wherein mirror elements located in the first position reflect light emitted by the light source of the illumination device so that it emerges from the illumination device.
• the first position usually corresponds to the on-state, whereas the second position usually corresponds to the off-state of a DMD chip.
• headlamps can be designed as high-powered headlamps or as matrix headlamps, which can illuminate areas in front of the vehicle and avoid the illumination of other areas.
• a disadvantage of such lighting devices is usually considered that the reflected light in the second position of the mirror elements of the light source is not used, but is absorbed in an absorber.
• a lighting device of the type mentioned is known for example from DE 197 37 653 A1.
• the illumination device described therein comprises a light source and a digital micromirror device which can deliberately reflect portions of the light, so that these components can emerge from the illumination device through projection optics.
• DE 197 37 653 A1 proposes that the light of the light source reflected in the second position of the mirror elements should not impinge on an absorber but on a solar cell, so that this portion of the light can be converted back into electrical energy.
• the problem underlying the present invention is the provision of a lighting device of the type mentioned, which can make good use of the reflected light of the light source in the second position of the mirror elements. Furthermore, a method for operating such a lighting device is to be specified.
• the illumination device comprises sensor means for detecting a light intensity
• the sensor means are arranged in the illumination device such that at least a portion of the light reflected in the second position of the mirror elements impinges on the sensor means, so that they can detect the light intensity of this component.
• the sensor means may be formed for example as a photodiode.
• the lighting device comprises control means which can compare the light intensity detected by the sensor means with a desired value or a light intensity detected in a previously performed measurement.
• the control means can be designed such that they can decide on the basis of the detected light intensity whether individual mirror elements or groups of mirror elements are functional.
• the illumination device comprises a solar cell, which is arranged in the illumination device such that at least a portion of the light reflected in the second position of the mirror elements impinges on the solar cell. By this measure, the incident on the solar cell portion of the light can be converted back into electrical energy.
• the illumination device may comprise a spectrometer which is arranged in the illumination device such that at least a portion of the light reflected in the second position of the mirror elements impinges on the spectrometer.
• a spectrometer By means of a spectrometer, the color of the light incident on the spectrometer can be determined.
• the spectrometer can be used to check whether the color of the detected light corresponds to the desired color .
• the power of one of the laser diodes may be reduced over time so that the color of the light emanating from the RGB light source changes.
• the spectrometer can detect this change and then cause the delivery of a message to the driver of the motor vehicle, with which this is pointed to the color change.
• the activation of the individual laser diodes can also be actively influenced in order to achieve an alignment of the color of the light emanating from the RGB light source with the desired color.
• the solar cell and / or the spectrometer are arranged in the illumination device, for example with the aid of at least one partially transmissive mirror, such that both of the light reflected in the second position of the mirror elements have a share on the sensor means. as well as a portion of the solar cell and / or the spectrometer incident.
• both the functionality of the digital micromirror device and the presence of the desired color of the light emitted by the illumination device can be determined be checked.
• a part of the light generated by the light source can be converted back into electrical energy.
• FIG. 1 shows a schematic view of a first embodiment of a lighting device according to the invention
• FIG. 2 shows a schematic view of a second embodiment of a lighting device according to the invention
• FIG 3 shows a schematic view of a third embodiment of a lighting device according to the invention.
• a lighting device comprises a merely schematically indicated light source 1, the light 2 emits.
• the light source 1 may, for example, be designed as a white light source and have at least one blue light-emitting diode (LED) and additional converter means for producing white light.
• the light source 1 may alternatively be designed as an RGB light source and, for example, have a red, a green and a blue laser diode whose light causes a white color impression after a mixture.
• the illumination device furthermore comprises a digital micromirror device 3, which is only schematically indicated, and which is designed in particular as a commercially available DMD chip.
• the digital micromirror device 3 has a plurality of mirror elements 4, of which only one is imaged.
• the mirror elements 4 are arranged in a two-dimensional array. Each of the mirror elements 4 can be moved individually or in groups back and forth between at least two stable states. Thanks to the selective actuation of each individual mirror element 4 of the digital micromirror device 3, segmentation of the incident light 2 is possible.
• the mirror element 4 is shown in dashed lines in a first state. This state is called on-state for a DMD chip. In the first state, the mirror element 4 is tilted, for example, by an angle of + 12 ° relative to the vertical in FIG. Furthermore, in Fig. 1, the mirror element is shown in phantom in a second state. This state is called off-state in a DMD chip. In the second state, the mirror element 4 is tilted, for example, at an angle of -12 ° with respect to the vertical in FIG.
• a third state is shown in solid. This condition is called flat-state in a DMD chip.
• the mirror element 4 is not tilted relative to the vertical in FIG.
• the flat-state is not used in the embodiment depicted in FIG. 1.
• the lighting device further comprises schematically illustrated Auskoppel- means 5, which are formed for example as a projection optics. Those mirror elements 4, which are in the first state, reflect the incident light 2 so that it emerges as reflected light 2 'through the decoupling means 5 from the lighting device.
• the illumination device further comprises sensor means 6 which are shown schematically and which are designed, for example, as a photodiode. Those mirror elements 4, which are in the second state, reflect the incident light 2 so that it hits the sensor means 6 as reflected light 2 ".
• the sensor means 6 are adapted to detect the intensity of the incident light 2 ".
• the lighting device may further comprise non-illustrated control means or transmit the detected light intensity to on-vehicle control means.
• control means can draw conclusions about the functionality of the digital micromirror device or individual mirror elements or groups of mirror elements.
• the light intensity detected by the sensor means can be compared with a setpoint value or a light intensity detected in the case of a previously performed measurement.
• control means can be designed such that they can decide on the basis of the detected light intensity whether individual mirror elements or groups of mirror elements are functional. If a defect of the digital micro-mirror device or individual mirror elements or groups of mirror elements is detected, the control means may cause the delivery of a message to the driver of the motor vehicle, with which he is informed of the defect.
• the control means may be designed or programmed in such a way that they switch on the light source 1 in order to check the functionality of the mirror elements 4 and, successively, individual mirror elements 4 or groups of mirror elements 4 in FIG transfer the second position. For example, this can be done line by line or column by column. After transferring individual mirror elements 4 or groups of mirror elements 4 into the second position, the intensities of the light 2 "incident on the sensor means 6 in these second positions are respectively measured. In this way, all mirror elements 4 can be gradually checked for functionality.
• the illumination device comprises, in addition to the sensor means 6, a spectrometer 7, on which also a part of the light 2 "reflected in the second position of the mirror elements 4 can impinge.
• a partially transparent mirror 8 serving as a beam splitter is provided, which allows a portion of the light 2 "to pass through the sensor means 6 and reflects another part, so that it can be reflected by a mirror 9 onto the spectrometer 7.
• the light emanating from the partial transmissive mirror 8 2 "directly impinges on the spectrometer 7.
• the color of the impinging on the spectrometer 7 light 2 " can be determined.
• the light source 1 is embodied as an RGB light source in which a white color impression is to be produced by mixing red, green and blue light
• the spectrometer 7 can be used to check whether the color of the detected light is 2 "of the desired color - speaks.
• the power of one of the laser diodes may decrease over time, so that the color of the light 2 emanating from the RGB light source changes.
• the control means can detect this change on the basis of the light color detected by the spectrometer 7 and then cause the delivery of a message to the driver of the motor vehicle, with which he is informed of the color change.
• the activation of the individual laser diodes can also be actively influenced in order to achieve an alignment of the color of the light 2 emanating from the RGB light source with the desired color.
• the illumination device comprises, in addition to the sensor means 6 and the spectrometer 7, a solar cell 10, on which also a part of the light 2 "reflected in the second position of the mirror elements 4 can impinge.
• a solar cell 10 on which also a part of the light 2 "reflected in the second position of the mirror elements 4 can impinge.
• another partially transmissive mirror 11 is provided, which reflects part of the light 2 "onto the spectrometer 7 and allows another part to pass through, so that it can be reflected by a mirror 9 onto the solar cell 10.
• the light 2 "emanating from the semitransparent mirror 11 impinges directly on the solar cell 10.
• the solar cell 10 can convert back light 2 "incident on it into electrical energy.
• the illumination device comprises a solar cell 10 instead of the spectrometer 7.

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• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Lighting Device Outwards From Vehicle And Optical Signal (AREA)
• Non-Portable Lighting Devices Or Systems Thereof (AREA)

Priority Applications (1)

Applications Claiming Priority (2)

Publications (1)

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Family Applications (1)

Country Status (3)

Citations (6)

Family Cites Families (3)

• 2017
  • 2017-12-04 DE DE102017128674.8A patent/DE102017128674A1/de active Pending
• 2018
  • 2018-12-03 CN CN201880078516.4A patent/CN111433080A/zh active Pending
  • 2018-12-03 WO PCT/EP2018/083293 patent/WO2019110479A1/de active Application Filing

Patent Citations (6)

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