WO2022131302A1 - Vehicle lamp - Google Patents

Vehicle lamp Download PDF

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Publication number
WO2022131302A1
WO2022131302A1 PCT/JP2021/046327 JP2021046327W WO2022131302A1 WO 2022131302 A1 WO2022131302 A1 WO 2022131302A1 JP 2021046327 W JP2021046327 W JP 2021046327W WO 2022131302 A1 WO2022131302 A1 WO 2022131302A1
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WO
WIPO (PCT)
Prior art keywords
light source
scanning
scan
semiconductor light
pwm
Prior art date
Application number
PCT/JP2021/046327
Other languages
French (fr)
Japanese (ja)
Inventor
賢 菊池
佳典 柴田
Original Assignee
株式会社小糸製作所
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 株式会社小糸製作所 filed Critical 株式会社小糸製作所
Priority to JP2022570043A priority Critical patent/JPWO2022131302A1/ja
Publication of WO2022131302A1 publication Critical patent/WO2022131302A1/en

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    • 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
    • B60Q1/00—Arrangement of optical signalling or lighting devices, the mounting or supporting thereof or circuits therefor
    • B60Q1/02—Arrangement of optical signalling or lighting devices, the mounting or supporting thereof or circuits therefor the devices being primarily intended to illuminate the way ahead or to illuminate other areas of way or environments
    • B60Q1/04—Arrangement of optical signalling or lighting devices, the mounting or supporting thereof or circuits therefor the devices being primarily intended to illuminate the way ahead or to illuminate other areas of way or environments the devices being headlights
    • 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
    • B60Q1/00—Arrangement of optical signalling or lighting devices, the mounting or supporting thereof or circuits therefor
    • B60Q1/02—Arrangement of optical signalling or lighting devices, the mounting or supporting thereof or circuits therefor the devices being primarily intended to illuminate the way ahead or to illuminate other areas of way or environments
    • B60Q1/04—Arrangement of optical signalling or lighting devices, the mounting or supporting thereof or circuits therefor the devices being primarily intended to illuminate the way ahead or to illuminate other areas of way or environments the devices being headlights
    • B60Q1/14—Arrangement of optical signalling or lighting devices, the mounting or supporting thereof or circuits therefor the devices being primarily intended to illuminate the way ahead or to illuminate other areas of way or environments the devices being headlights having dimming means
    • 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
    • F21S41/14—Illuminating devices specially adapted for vehicle exteriors, e.g. headlamps characterised by the light source characterised by the type of light source
    • F21S41/141—Light emitting diodes [LED]
    • F21S41/151—Light emitting diodes [LED] arranged in one or more lines
    • 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
    • F21S41/14—Illuminating devices specially adapted for vehicle exteriors, e.g. headlamps characterised by the light source characterised by the type of light source
    • F21S41/16—Laser light sources
    • 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
    • F21S41/65—Illuminating devices specially adapted for vehicle exteriors, e.g. headlamps characterised by a variable light distribution by acting on light sources
    • F21S41/663—Illuminating devices specially adapted for vehicle exteriors, e.g. headlamps characterised by a variable light distribution by acting on light sources by switching light sources
    • 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
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21W—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES F21K, F21L, F21S and F21V, RELATING TO USES OR APPLICATIONS OF LIGHTING DEVICES OR SYSTEMS
    • F21W2102/00—Exterior vehicle lighting devices for illuminating purposes
    • F21W2102/10—Arrangement or contour of the emitted light
    • F21W2102/13—Arrangement or contour of the emitted light for high-beam region or low-beam region
    • F21W2102/135—Arrangement or contour of the emitted light for high-beam region or low-beam region the light having cut-off lines, i.e. clear borderlines between emitted regions and dark regions
    • F21W2102/14—Arrangement or contour of the emitted light for high-beam region or low-beam region the light having cut-off lines, i.e. clear borderlines between emitted regions and dark regions having vertical cut-off lines; specially adapted for adaptive high beams, i.e. wherein the beam is broader but avoids glaring other road users
    • F21W2102/145—Arrangement or contour of the emitted light for high-beam region or low-beam region the light having cut-off lines, i.e. clear borderlines between emitted regions and dark regions having vertical cut-off lines; specially adapted for adaptive high beams, i.e. wherein the beam is broader but avoids glaring other road users wherein the light is emitted between two parallel vertical cutoff lines, e.g. selectively emitted rectangular-shaped high beam
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21Y—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES F21K, F21L, F21S and F21V, RELATING TO THE FORM OR THE KIND OF THE LIGHT SOURCES OR OF THE COLOUR OF THE LIGHT EMITTED
    • F21Y2115/00—Light-generating elements of semiconductor light sources
    • F21Y2115/10—Light-emitting diodes [LED]
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21Y—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES F21K, F21L, F21S and F21V, RELATING TO THE FORM OR THE KIND OF THE LIGHT SOURCES OR OF THE COLOUR OF THE LIGHT EMITTED
    • F21Y2115/00—Light-generating elements of semiconductor light sources
    • F21Y2115/30—Semiconductor lasers

Definitions

  • This disclosure relates to vehicle lamps used in automobiles and the like.
  • Vehicle lighting fixtures can generally switch between low beam and high beam.
  • the low beam illuminates the vicinity of the own vehicle with a predetermined illuminance, and the light distribution rule is set so as not to give glare to the oncoming vehicle or the preceding vehicle, and is mainly used when traveling in an urban area.
  • the high beam illuminates a wide area and a distant place in front with a relatively high illuminance, and is mainly used when traveling at high speed on a road where there are few oncoming vehicles and preceding vehicles. Therefore, although the high beam has better visibility by the driver than the low beam, there is a problem that glare is given to the driver and pedestrian of the vehicle existing in front of the vehicle.
  • ADB Adaptive Driving Beam
  • a shutter method for controlling an actuator, a rotary method, an LED array method, etc. have been proposed.
  • the width of the light-off area (light-shielding area) can be continuously changed, but the number of light-off areas is limited to one.
  • the LED array method it is possible to set a plurality of extinguishing areas, but the width of the extinguishing area is limited by the irradiation width of the LED chip, so that the extinguishing area is discrete.
  • the applicant has proposed a scanning method as an ADB method that can solve these problems (see Patent Documents 2 and 3).
  • the scan method is to incident light on a rotating reflector (blade mirror), reflect the incident light at an angle according to the rotation position of the reflector, scan the reflected light in front of the vehicle, and turn on and off the light source.
  • a desired light distribution pattern is formed in front of the vehicle by changing the light distribution pattern according to the rotation position of the vehicle.
  • the light source is turned on and off (on and off) in a time-division manner while keeping the amount of drive current flowing through the light source constant during one scan. Therefore, it was easy to realize a glare-free function that shields a predetermined area from light, but the illuminance in the irradiation area was restricted to a substantially constant level.
  • Patent Document 4 discloses a specific method for forming a light distribution using a scanning type vehicle lamp.
  • a light distribution is formed by a multi-channel light source.
  • Each of the multi-channel light sources is responsible for a part of the horizontal range, and the scan range of each light source is shifted horizontally while partially overlapping the scan range of the other light sources.
  • the amount of light of each light source is controlled by so-called DC dimming (analog dimming), and is variable in units of one scan due to the limitation of response speed.
  • the illuminance at each scanning position can be controlled by combining multiple light sources on, off, and the amount of light, and it is now compatible with various light distribution patterns other than the glare-free function (for example, electronic swivel). There is.
  • Patent Document 4 requires light sources and lighting circuits of many channels to form one light distribution, has a complicated structure, and also controls the light source to form a desired light distribution. It was complicated.
  • the present disclosure has been made in view of the above problems, and one of the exemplary purposes of the embodiment is to provide a vehicle lamp capable of generating various light distribution patterns other than the glare-free function.
  • Vehicle lighting fixtures include a semiconductor light source, a scanning light source that scans an instantaneous irradiation spot based on the emitted light of the semiconductor light source in the horizontal direction of the light distribution, and a semiconductor light source at each scanning position in synchronization with scanning of the scanning light source. It is equipped with a lighting circuit capable of dimming the amount of light in multiple gradations by pulse modulation.
  • the pulse modulation cycle T PWM is T PWM ⁇ A ⁇ ( ⁇ SPOT / ⁇ SCAN ) ⁇ T SCAN is satisfied.
  • A is a constant of A ⁇ 1.
  • Vehicle lighting fixtures include a semiconductor light source, a scanning light source that scans an instantaneous irradiation spot based on the emitted light of the semiconductor light source in the horizontal direction of the light distribution, and a semiconductor light source at each scanning position in synchronization with scanning of the scanning light source. It is equipped with a lighting circuit capable of dimming the amount of light in multiple gradations by pulse modulation.
  • the pulse modulation cycle T PWM is T PWM ⁇ SPOT / v ⁇ Meet.
  • A is a constant of A ⁇ 1.
  • FIG. 2 (a) and 2 (b) are diagrams illustrating the formation of glare-free light distribution by vehicle lamps.
  • 3 (a) and 3 (b) are diagrams illustrating the formation of a partially dimmed light distribution by a vehicle lamp.
  • 4 (a) and 4 (b) are diagrams illustrating an electronic swivel by a vehicle lamp. It is a figure which shows the lamp for a vehicle which concerns on the comparative technique. It is a figure explaining the light distribution formation by the lamp for vehicle which concerns on the comparative technique.
  • Vehicle lighting fixtures include a semiconductor light source, a scanning light source that scans an instantaneous irradiation spot based on the emitted light of the semiconductor light source in the horizontal direction of the light distribution, and a semiconductor light source at each scanning position in synchronization with scanning of the scanning light source. It is equipped with a lighting circuit capable of dimming the amount of light in multiple gradations by pulse modulation.
  • the amount of light from the light source can be changed at high speed according to the scanning position within one scanning cycle. Therefore, as compared with DC dimming (analog dimming) in which the amount of light is constant within one scanning cycle, the variation of light distribution that can be formed by one light source increases. As a result, the number of light sources and lighting circuits can be reduced as compared with the conventional case, or control can be simplified.
  • Pulse modulation includes pulse width modulation (PWM), pulse frequency modulation (PFM), pulse density modulation (PDM), etc., and switches the drive current flowing through the light source at high speed to obtain the time average value of the drive current. It may include varying modulation schemes.
  • the scanning frequency f SCAN of the vehicle lamp is not higher than the frame rate f FRAME of the camera, stripes may be transferred to the image taken by the camera. Therefore, the scanning frequency f SCAN is set higher than the frame rate f FRAME , in other words, the scanning cycle T SCAN (1 / f SCAN ) is set shorter than the imaging cycle 1 / f FRAME .
  • the present inventors have come to recognize that when scanning and pulse dimming are used in combination, fringes are reflected in the image of the camera depending on the pulse modulation cycle T PWM . When stripes are reflected, problems such as deterioration of image recognition accuracy occur.
  • the instantaneous irradiation spot has a certain finite width ⁇ SPOT .
  • ⁇ SCAN the angle at which the instantaneous irradiation spot is scanned
  • ⁇ SCAN the transit time ⁇ required for the instantaneous irradiation spot to move ⁇ SPOT.
  • the pulse modulation cycle T PWM is set.
  • T PWM ⁇ A ⁇ ( ⁇ SPOT / ⁇ SCAN ) ⁇ T SCAN may be satisfied.
  • A is a constant of A ⁇ 1. This makes it possible to suppress the reflection of stripes.
  • the transit time ⁇ is rewritten as ⁇ SPOT / v ⁇ . Therefore, in one embodiment, when the horizontal width of the instantaneous irradiation spot is ⁇ SPOT and the scan speed is v ⁇ , the pulse modulation cycle T PWM is set. T PWM ⁇ A ⁇ ⁇ SPOT / v ⁇ May be satisfied. A is a constant of A ⁇ 1. This makes it possible to suppress the reflection of stripes.
  • the constant A can be defined according to the intensity distribution of the instantaneous irradiation spot. For example, when assuming a beam having a rectangular intensity distribution, A ⁇ 1, and in the case of a Gaussian distribution, A needs to be set smaller, for example, A ⁇ 0.5. For example, when A ⁇ 0.2, it is possible to suppress the reflection of stripes in various intensity distributions.
  • the scanning light source may further include, in addition to the semiconductor light source, a reflector that receives the emitted light of the semiconductor light source and scans the reflected light in front of the vehicle by repeating a predetermined periodic motion.
  • the lighting circuit may generate a control waveform of pulse modulation in synchronization with the motion of the reflector, and may switch the drive current supplied to the semiconductor light source according to the control waveform.
  • the lighting circuit may include a series switch provided in series with the semiconductor light source and a constant current driver connected to the series connection circuit of the series switch and the semiconductor light source.
  • the lighting circuit may switch the series switch in a duty cycle according to the scanning position.
  • Patent Document 4 In the prior art (Patent Document 4), two semiconductor light sources are connected in series, and a bypass switch is provided in parallel with each semiconductor light source. In this configuration, switching one bypass switch at a frequency sufficiently higher than the scanning frequency will affect the other semiconductor light source. On the other hand, by individually driving each semiconductor light source with a series switch, it is possible to eliminate the influence of driving one channel on other channels.
  • the constant current driver may include a switching converter and a converter controller that drives the switching converter so that the detected value of the output current of the switching converter approaches a predetermined target value.
  • the "state in which the member A is connected to the member B" means that the member A and the member B are physically directly connected, and the member A and the member B are electrically connected to each other. It also includes cases of being indirectly connected via other members that do not substantially affect the connection state or impair the functions and effects performed by the combination thereof.
  • a state in which the member C is provided between the member A and the member B means that the member A and the member C, or the member B and the member C are directly connected, and their electricity. It also includes cases of being indirectly connected via other members that do not substantially affect the connection state or impair the functions and effects performed by the combination thereof.
  • the reference numerals attached to electric signals such as voltage signals and current signals, or circuit elements such as resistors and capacitors have their respective voltage values, current values, resistance values, and capacitance values as necessary. It shall be represented.
  • FIG. 1 is a diagram showing a vehicle lamp 100A according to the first embodiment.
  • the vehicle lamp 100A of FIG. 1 has a scan-type ADB function and forms various light distribution patterns in front of the vehicle.
  • the vehicle lamp 100A mainly includes a scanning light source 200A, a lighting circuit 300A, and a light distribution controller 400.
  • the light distribution controller 400 receives and distributes information (sensor information) S1 and information (vehicle information) S2 such as vehicle speed and steering angle from sensors such as cameras and LiDAR (Light Detection and Ringing, Laser Imaging Detection and Ringing). Determine the light pattern.
  • the light distribution controller 400 may be housed in the lamp body or may be provided on the vehicle side.
  • the light distribution controller 400 transmits information (light distribution pattern information) S3 indicating a light distribution pattern to the vehicle lamp 100.
  • the light distribution controller 400 is also referred to as an ADB ECU (Electronic Control Unit).
  • the scanning light source 200A includes a light source unit 210A, a scanning optical system 220, and a projection optical system 230.
  • the light source unit 210A includes one semiconductor light source 212 and a heat sink (not shown).
  • An LED (light emitting diode), a laser diode, or the like can be used as the semiconductor light source 212.
  • the scanning optical system 220 scans the emitted light (beam) BM of the semiconductor light source 212 in front of the vehicle.
  • the scanning optical system 220 includes a motor 222 and one or a plurality of M (two in this example) blade mirrors 224_1224_2.
  • the M blade mirrors (M ⁇ 2) are mounted at 360 / M ° offset positions, and in this example, the two blade mirrors are mounted at 180 ° offset positions.
  • the optical axis of the semiconductor light source 212 is directed so that the emitted beam BM illuminates one of the M blade mirrors.
  • the incident light BM on the blade mirror 224 is reflected at a reflection angle corresponding to the position of the blade mirror 224 (rotation angle of the rotor), and an instantaneous irradiation spot SPT is formed on the virtual vertical screen 900 in front of the vehicle.
  • the instantaneous irradiation spot SPT has a width ⁇ v in the horizontal direction (H direction) and a width ⁇ h in the vertical direction (V direction).
  • the rotation of the blade mirror 224 changes the reflection angle, that is, the emission direction of the reflected beam BMr, and the horizontal (H direction) position (scanning position) of the instantaneous irradiation spot SPT moves.
  • a light distribution pattern PTN is formed in front of the vehicle.
  • the light distribution pattern PTN formed by one beam BM extends over the entire horizontal range of the vehicle lamp 100A to ⁇ MAX to + ⁇ MAX . That is, the scanning light source 200A scans the reflected beam BMr over the entire horizontal range.
  • ⁇ MAX is about 20 to 25 °.
  • the entire range is the entire range that can be irradiated by scanning, and does not include the range irradiated by a light source other than scanning.
  • the lighting circuit 300A determines the amount of light of the semiconductor light source 212 at each scanning position, that is, the intensity of the beam BM, in synchronization with the scanning of the scanning light source 200A so that the light distribution pattern indicated by the light distribution pattern information S3 can be obtained. Dimming with multiple gradations by pulse modulation.
  • the average amount of drive current I LEDs flowing through the semiconductor light source 212 is changed by PWM (pulse width modulation), and the amount of light of the semiconductor light source 212 is changed (PWM dimming).
  • the PWM frequency is set sufficiently higher than the scanning frequency, and it is desirable that the PWM frequency is, for example, several kHz to several hundred kHz.
  • the lighting circuit 300A may change the amount of current I OUT in a scanning cycle or a control cycle longer than that. That is, PWM dimming and DC dimming may be used together.
  • PWM dimming and DC dimming may be used together.
  • FIG. 2 (a) and 2 (b) are diagrams illustrating the formation of glare-free light distribution by the vehicle lamp 100A.
  • the glare-free light distribution 910 of FIG. 2 includes a light-shielding portion 912 and an irradiation portion 914,916.
  • FIG. 2A shows the light distribution on the virtual vertical screen
  • FIG. 2B shows the operation waveform of the vehicle lamp 100A corresponding to the light distribution of FIG. 2A.
  • the vertical and horizontal axes of the waveform charts and time charts referred to in the present specification are appropriately enlarged or reduced for easy understanding, and each waveform shown is also simplified for easy understanding. It is made, or exaggerated or emphasized.
  • the lighting circuit 300A sets the duty cycle of the drive current I LED of the semiconductor light source 212 to a non-zero value (100% constant value in this example) in the section corresponding to the irradiation portions 914 and 916, and corresponds to the light shielding portion 912. In this section, the duty cycle of the drive current I LED is set to 0%.
  • FIG. 3 (a) and 3 (b) are diagrams illustrating the formation of a partially dimmed light distribution by the vehicle lamp 100A.
  • FIG. 3A shows the horizontal illuminance distribution of the light distribution on the virtual vertical screen
  • FIG. 3B shows the operation waveform of the vehicle lamp 100A corresponding to the light distribution of FIG. 3A.
  • the partial dimming distribution 920 shown in FIG. 3A includes two dimming portions 922,924 and three non-dimming portions 926,927,928.
  • the duty cycle of the drive current I LED of the semiconductor light source 212 is fixed to 100% in the section corresponding to the non-dimming portion (irradiation portion) 926,927,928, and the duty cycle is fixed to the dimming portion 922,924.
  • the duty cycle of the drive current I LED is 50% and 25%, respectively.
  • partial dimming can be realized by PWM-controlling the drive current I LED flowing through a single semiconductor light source.
  • FIG. 4 (a) and 4 (b) are diagrams illustrating an electronic swivel by a vehicle lamp 100A.
  • FIG. 4A shows the brightest light distribution in the center
  • FIG. 4B shows the brightest light distribution on the right side.
  • the electronic swivel function can be realized by PWM-controlling the drive current I LED flowing through a single semiconductor light source.
  • FIG. 5 is a diagram showing a vehicle lamp 100R according to a comparative technique.
  • the light source unit 210R includes a plurality of semiconductor light sources 212_1 to 212_N. Each of the emission beams BM 1 to BM N of the semiconductor light sources 212_1 to 212_N is scanned in different horizontal ranges on the virtual vertical screen 900, and a plurality of individual light distribution patterns are scanned by scanning the emission beams BM 1 to BM N. PTN 1 to PTN N are formed.
  • the light distribution formed by the vehicle lamp 100R is a superposition of a plurality of individual light distribution patterns PTN 1 to PTN N.
  • the lighting circuit 300R supplies drive currents I LED1 to I LEDN to each of the plurality of semiconductor light sources 212_1 to 212_N.
  • the lighting circuit 300R can turn on and off the drive currents I LED1 to I LEDN , respectively, within one cycle. Further, the lighting circuit 300R can control the amount of current during the on period of each of the drive currents I LED1 to I LEDN by DC dimming, but the amount of current can be switched only for each scan.
  • FIG. 6 is a diagram illustrating light distribution formation by the vehicle lamp 100R according to the comparative technique.
  • N 6 channels.
  • the irradiation widths of the plurality of individual light distribution patterns PTN 1 to PTN 6 are controlled. By superimposing them, a light distribution pattern with a bright left front is formed in this example.
  • the light amount of the light source can be changed at high speed according to the scanning position within one scanning cycle. Therefore, as compared with the conventional analog dimming in which the amount of light is constant within one scanning cycle, the variation of the light distribution that can be formed by one light source increases. As a result, the number of light sources and lighting circuits can be reduced as compared with the conventional case, or control can be simplified.
  • the present disclosure is grasped as a block diagram and a circuit diagram of FIG. 1, and extends to various devices and circuits derived from the waveform diagrams of FIGS. 3 to 4 or the above description, and is limited to a specific configuration. It's not a thing.
  • a more specific configuration example will be described not to narrow the scope of the present disclosure but to facilitate and clarify the essence of the disclosure and the circuit operation.
  • FIG. 7 is a block diagram showing a configuration example of the lighting circuit 300A.
  • the light distribution controller 400 receives sensor information S1 and vehicle information S2.
  • the light distribution controller 400 detects the situation in front of the vehicle, specifically, the presence / absence of an oncoming vehicle, a preceding vehicle, the presence / absence of a pedestrian, and the like based on the sensor information S1. Further, the light distribution controller 400 detects the current vehicle speed, steering angle, and the like based on the vehicle information S2. Based on these information, the light distribution controller 400 determines a light distribution pattern to be irradiated to the front of the vehicle, and transmits information (light distribution pattern information) S3 instructing the light distribution pattern to the lighting circuit 300A.
  • the lighting circuit 300A changes the light amount (luminance) of the semiconductor light source 212 in multiple gradations by PWM dimming while synchronizing with the rotation of the blade mirror 224 based on the light distribution pattern information S3.
  • the lighting circuit 300A mainly includes a position detector 302, a PWM signal generation unit 310, and a constant current driver (hereinafter referred to as LED driver) 320.
  • the position detector 302 is provided to detect the position of the blade mirror 224, in other words, the scanning position of the current beam.
  • the position detector 302 generates a position detection signal S4 indicating the timing at which the predetermined reference point of the blade mirror 224 passes the predetermined position.
  • the reference portion may be the end portion (separation) of the two blade mirrors 224, or may be the center of each blade mirror, and may be any location.
  • a Hall element may be attached to the motor 222 that rotates the blade mirror 224.
  • the Hall signal from the Hall element has a periodic waveform corresponding to the position of the rotor, that is, the position of the blade mirror.
  • the position detector 302 may detect the timing at which the polarity of the Hall signal is inverted, and specifically, may be configured by a Hall comparator that compares a pair of Hall signals.
  • the position detection method of the blade mirror 224 by the position detector 302 is not limited to the one using a Hall element.
  • the position detector 302 may generate the position detection signal S4 by using an optical or other rotary encoder that detects the position of the rotor of the motor 222.
  • the position detector 302 may include a photosensor provided on the back side of the blade mirror 224 and a light source for position detection that irradiates light from the surface side of the blade mirror 224 toward the photosensor.
  • the blade mirror 224 may be provided with a slit or a pinhole. This makes it possible to detect when the slit or pinhole passes over the photo sensor.
  • the slit may be a gap between the two blade mirrors 224.
  • the light source for position detection may be an infrared light source or a semiconductor light source 212. As described above, there may be various variations in the configuration of the position detector 302.
  • the PWM signal generation unit 310 generates a pulse dimming signal PWM_DIM in synchronization with the movement of the blade mirror 224.
  • the PWM signal generation unit 310 may be implemented by combining the microcontroller 304 and the software program, or may be implemented only by hardware.
  • the microcontroller 304 and the LED driver 320 may be mounted on one substrate or may be arranged in one housing.
  • the frequency of the pulse dimming signal PWM_DIM is set higher than 200 Hz, and can be, for example, several kHz to several tens of kHz.
  • the duty cycle of the pulse dimming signal PWM_DIM defines the amount of light of the semiconductor light source 212, and the duty cycle may be set for each PWM cycle or may be set for each of a plurality of PWM cycles. It is also good.
  • the LED driver 320 supplies a drive current I LED to the semiconductor light source 212.
  • the current amount of the drive current I LED is stabilized to a predetermined target value, and the LED driver 320 switches the drive current I LED according to the pulse dimming signal PWM_DIM.
  • FIG. 8 is a circuit diagram showing a configuration example (320A) of the LED driver 320.
  • the LED driver 320A includes a buck converter 322, a series switch 323, and a driver circuit 324.
  • the series switch 323 and the semiconductor light source 212 are connected in series.
  • the series switch 323 is inserted on the anode side of the semiconductor light source 212, but may be inserted between the cathode and the ground.
  • the buck converter 322 is a constant current output switching converter and includes an output circuit 326 and a converter controller 328.
  • the output circuit 326 includes a switching transistor MH, a synchronous rectifying transistor ML, an inductor L1, and an output capacitor C1.
  • the converter controller 328 switches and controls the switching transistor MH and the synchronous rectifying transistor ML of the output circuit 326 so that the output current I OUT of the buck converter 322 approaches a predetermined target amount while the series switch 323 is on.
  • the control method of the converter controller 328 is not particularly limited, and may be an analog controller using an error amplifier, a digital controller including a PID (proportional / integral / differential) compensator, or a hysteresis control controller.
  • the driver circuit 324 drives the series switch 323 in response to the pulse dimming signal PWM_DIM.
  • the driver circuit 324 may be integrated in the same IC as the converter controller 328.
  • the converter controller 328 stops the switching of the switching transistor MH and the synchronous rectifying transistor ML when the pulse dimming signal PWM_DIM is at the off level indicating the off of the series switch 323.
  • FIG. 9 is a circuit diagram showing another configuration example (320B) of the LED driver 320.
  • the LED driver 320B includes a buck converter 322, a bypass switch SW2, and a driver circuit 324.
  • the buck converter 322 may include an output circuit 326 and a converter controller 328, as in FIG.
  • the buck converter 322 produces a regulated output current I OUT to a predetermined target amount.
  • the bypass switch SW2 is connected in parallel with the semiconductor light source 212.
  • the driver circuit 324 drives the bypass switch SW2 in response to the pulse dimming signal PWM_DIM.
  • the output current I OUT is supplied to the semiconductor light source 212 as the drive current I LED
  • the output current I OUT flows to the bypass switch SW2, so that the drive current I LED Is zero.
  • FIG. 10 is a circuit diagram showing still another configuration example (320C) of the LED driver 320.
  • the LED driver 320C includes a constant voltage converter 327 and a constant current source 329.
  • the constant voltage converter 327 produces an output voltage V OUT stabilized at a predetermined voltage level.
  • the constant current source 329 is connected in series with the semiconductor light source 212.
  • the constant current source 329 can be switched on and off, and during the on period, a predetermined amount of stabilized drive current I LED is generated (sink).
  • the on / off of the constant current source 329 is controlled according to the pulse dimming signal PWM_DIM.
  • the configuration of the LED driver 320 is not limited to the one illustrated here.
  • FIG. 11 is a diagram showing a vehicle lamp 100B according to the second embodiment. Differences from the first embodiment will be described.
  • the light source unit 210B of the scanning light source 200B includes a plurality of N (N ⁇ 2) semiconductor light sources 212_1 to 212_N.
  • the optical axes of the semiconductor light sources 212_1 to 212_N are directed so that the respective emitted beams BM 1 to BM N illuminate one of the M blade mirrors.
  • the light beam of the emitted beam BM 2 of the semiconductor light source 212_2 is shown as a representative.
  • the incident light BM 2 on the blade mirror 224 is reflected at a reflection angle corresponding to the position of the blade mirror 224 (rotation angle of the rotor), and an instantaneous irradiation spot SPT 2 is formed on the virtual vertical screen 900 in front of the vehicle. do.
  • the instantaneous irradiation spot SPT 2 has a predetermined width in each of the horizontal direction (H direction) and the vertical direction (V direction).
  • the reflection angle changes, the emission direction of the reflected beam BMr 2 changes as shown by the broken line, and the horizontal (H direction) position (scanning position) of the instantaneous irradiation spot SPT 2 moves. do.
  • an individual light distribution pattern PTN 2 is formed in front of the vehicle.
  • the individual light distribution pattern PTN i is formed by scanning the i-th reflected beam BM r i .
  • the individual light distribution patterns PTN 1 to PTN N formed by the beams BM 1 to BM N are formed at different heights on the virtual vertical screen 900.
  • the light distribution pattern PTN_ALL of the entire vehicle lamp 100 is formed.
  • the individual light distribution patterns PTNs adjacent to each other in the vertical direction may slightly overlap each other in the vertical direction.
  • At least one of the plurality of individual light distribution patterns PTN 1 to PTN N extends over the entire horizontal range of the vehicle lamp 100B- ⁇ MAX to + ⁇ MAX . That is, the scanning light source 200B scans at least one of the plurality of beams BMr 1 to BMr N over the entire horizontal range. In the example of FIG. 11, all the individual light distribution patterns PTN 1 to PTN N extend over the entire horizontal range ⁇ MAX to + ⁇ MAX .
  • the lighting circuit 300B adjusts the light intensity of each of the semiconductor light sources 212_1 to 212_N at each scanning position, that is, the intensity of the beams BM 1 to BM N in multiple gradations in synchronization with the scanning of the scanning light source 200B. ..
  • the lighting circuit 300B may change the amount of current I OUT in a scanning cycle or a control cycle longer than that. That is, PWM dimming and DC dimming may be used together.
  • FIG. 12 is a block diagram showing a configuration example of the lighting circuit 300B of FIG.
  • the lighting circuit 300B includes a plurality of LED drivers 320_1 to 320_N corresponding to the plurality of semiconductor light sources 212_1 to 212_N.
  • the PWM signal generation unit 310 generates pulse dimming signals PWM_DIM_1 to PWM_DIM_N for a plurality of LED drivers 320_1 to 320_N so that the desired light distribution can be obtained.
  • the i-th (1 ⁇ i ⁇ N) LED driver 320 supplies a PWM-modulated drive current I LEDi to the corresponding semiconductor light source 212_i.
  • the configuration of the LED driver 320 is the same as that of the first embodiment.
  • the microcontroller 304 and the plurality of LED drivers 320_1 to 320_N may be mounted on one substrate, or may be arranged in one housing.
  • the resolution in the height direction can be improved as compared with the first embodiment.
  • the entire light distribution is vertically divided into a plurality of regions, and a plurality of individual light distribution patterns PTN 1 to PTN N are associated with the plurality of regions, but this is not the case. Some of the plurality of individual light distribution patterns PTN 1 to PTN N may completely overlap.
  • FIG. 13 is a diagram showing a vehicle lamp 100I according to the embodiment.
  • the vehicle lamp 100I is used together with the camera 2.
  • the camera 2 may be built in the vehicle lamp 100I or may be provided on the vehicle side.
  • the basic configuration of the vehicle lamp 100I is the same as that shown in FIG. 1, and includes a scanning light source 200A and a lighting circuit 300I.
  • the scanning light source 200A includes the semiconductor light source 212, and scans the instantaneous irradiation spot SPT based on the emitted light of the semiconductor light source 212 in the horizontal direction of the light distribution.
  • the lighting circuit 300I adjusts the amount of light of the semiconductor light source 212 at each scanning position in multiple gradations by pulse modulation in synchronization with the scanning of the scanning light source 200A.
  • the frame rate f FRAME of the camera 2 24 fps, 30 fps, 60 fps, 120 fps and the like are selected.
  • the scanning frequency f SCAN is set higher than the frame rate f FRAME , in other words, the scanning cycle T SCAN (1 / f SCAN ) is set shorter than the imaging cycle 1 / f FRAME .
  • the scanning frequency f SCAN is 200 Hz
  • the instantaneous irradiation spot SPT has a finite width ⁇ SPOT .
  • this width ⁇ SPOT is a spread angle, and is several degrees, specifically, about 1 ° to 2 °.
  • the pulse modulation cycle T PWM when the pulse modulation cycle T PWM is longer than or about the same as the transit time ⁇ , a part where the light is not sufficiently irradiated or a part where the light is not irradiated at all occurs, and the light and darkness is displayed on the screen. It was recognized that it occurred and appeared as stripes in the image of the camera.
  • the pulse modulation cycle T PWM is set.
  • T PWM ⁇ A x ( ⁇ SPOT / ⁇ SCAN ) x T SCAN May be satisfied. This makes it possible to suppress the reflection of stripes.
  • A is A ⁇ 1 and is a constant corresponding to the intensity distribution of the instantaneous irradiation spot.
  • the transit time ⁇ is rewritten as ⁇ SPOT / v ⁇ . Therefore, in one embodiment, when the horizontal width of the instantaneous irradiation spot is ⁇ SPOT and the scan speed is v ⁇ , the pulse modulation cycle T PWM is set. T PWM ⁇ A ⁇ ⁇ SPOT / v ⁇ May be satisfied.
  • ⁇ ( ⁇ ) be the intensity distribution in the horizontal scanning direction ( ⁇ direction) of the instantaneous irradiation spot SPT.
  • ⁇ ( ⁇ ) be the intensity distribution in the horizontal scanning direction ( ⁇ direction) of the instantaneous irradiation spot SPT.
  • f PWM (t, ⁇ ) is a function indicating the waveform of pulse width modulation.
  • the function of pulse width modulation can be expressed as a function f PWM (t) of time t only. Assuming that the pulse width modulation cycle is T PWM and the duty cycle is d, f PWM (t) is 1 when (t% T PWM ) ⁇ d and 0 when (t% T PWM )> d.
  • A% B is a remainder operator (modulo operator) indicating the remainder obtained by dividing A by B.
  • the intensity distribution of the light distribution formed on the screen is an integral of the instantaneous irradiation spots and is expressed by the following equation.
  • I ( ⁇ ) ⁇ 0: TPWM f PWM (t) ⁇ ⁇ ( ⁇ -v ⁇ ⁇ t) dt ⁇ 0: TPWM g (t) dt represents the integral in the range 0 to T PWM of the function g (t).
  • FIG. 14 is a diagram showing an example of the intensity distribution of the instantaneous irradiation spot SPOT.
  • the spot diameter is 2 °.
  • FIG. 15 is a diagram showing a light distribution pattern when the PWM frequency is changed.
  • the instantaneous irradiation spot is scanned over a range of 10 °.
  • the beam scanning cycle TSCAN is 5 ms and the PWM modulation duty cycle is 25%.
  • FIG. 16 is a diagram showing an example of the intensity distribution of the instantaneous irradiation spot SPOT.
  • a Gaussian beam having an intensity distribution of a Gaussian function with respect to the horizontal direction.
  • a beam with a standard deviation of 0.5 ° there are various ways to define the beam diameter. For example, if the width at 1 / e2 of the peak intensity is the spot diameter, the spot diameter is 2 °.
  • FIG. 17 is a diagram showing a light distribution pattern when the PWM frequency is changed.
  • the instantaneous irradiation spot is scanned over a range of 10 °.
  • the beam scanning cycle TSCAN is 5 ms and the PWM modulation duty cycle is 25%.
  • the constant A depends not only on the intensity distribution of the beam but also on the duty cycle of PWM modulation.
  • This disclosure relates to vehicle lamps used in automobiles and the like.

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Abstract

In the present invention, a scanning-type light source (200A) includes a semiconductor light source (212), and scans a beam (BM) from the semiconductor light source (212) in the horizontal direction of the light distribution. An illumination circuit (300I) is synchronized with the scanning of the scanning-type light source (200A), and can modulate the amount of light of the semiconductor light source (212) at individual scanning positions in multiple gradations using pulse modulation. The pulse-modulation period TPWM is such that TPWM <A×(θSPOT/θSCAN)×TSCAN, where θSPOT is the horizontal width of an instantaneous irradiation spot (SPT), θSCAN is the total scanning angle, and TSCAN is the scanning cycle, A being a constant that is less than or equal to 1.

Description

車両用灯具Vehicle lighting
　本開示は、自動車などに用いられる車両用灯具に関する。 This disclosure relates to vehicle lamps used in automobiles and the like.
　車両用灯具は、一般にロービームとハイビームとを切りかえることが可能である。ロービームは、自車近傍を所定の照度で照明するものであって、対向車や先行車にグレアを与えないよう配光規定が定められており、主に市街地を走行する場合に用いられる。一方、ハイビームは、前方の広範囲および遠方を比較的高い照度で照明するものであり、主に対向車や先行車が少ない道路を高速走行する場合に用いられる。したがって、ハイビームはロービームと比較してより運転者による視認性に優れているが、車両前方に存在する車両の運転者や歩行者にグレアを与えてしまうという問題がある。 Vehicle lighting fixtures can generally switch between low beam and high beam. The low beam illuminates the vicinity of the own vehicle with a predetermined illuminance, and the light distribution rule is set so as not to give glare to the oncoming vehicle or the preceding vehicle, and is mainly used when traveling in an urban area. On the other hand, the high beam illuminates a wide area and a distant place in front with a relatively high illuminance, and is mainly used when traveling at high speed on a road where there are few oncoming vehicles and preceding vehicles. Therefore, although the high beam has better visibility by the driver than the low beam, there is a problem that glare is given to the driver and pedestrian of the vehicle existing in front of the vehicle.
　近年、車両の周囲の状態にもとづいて、ハイビームの配光パターンを動的、適応的に制御するＡＤＢ（Adaptive Driving Beam）技術が実用化されている。ＡＤＢ技術は、車両の前方の先行車、対向車や歩行者の有無を検出し、車両に対応する領域を減光するなどして、車両に与えるグレアを低減するものである。 In recent years, ADB (Adaptive Driving Beam) technology that dynamically and adaptively controls the light distribution pattern of high beams based on the surrounding conditions of the vehicle has been put into practical use. The ADB technique detects the presence or absence of a preceding vehicle, an oncoming vehicle, or a pedestrian in front of the vehicle, dims the area corresponding to the vehicle, and reduces glare given to the vehicle.
　ＡＤＢ機能を実現する方式として、アクチュエータを制御するシャッター方式、ロータリー方式、ＬＥＤアレイ方式などが提案されている。シャッター方式やロータリー方式は、消灯領域（遮光領域）の幅を連続的に変化させることが可能であるが、消灯領域の数が１個に制限される。ＬＥＤアレイ方式は、消灯領域を複数個、設定することが可能であるが、消灯領域の幅が、ＬＥＤチップの照射幅に制約されるため、離散的となる。 As a method for realizing the ADB function, a shutter method for controlling an actuator, a rotary method, an LED array method, etc. have been proposed. In the shutter method and the rotary method, the width of the light-off area (light-shielding area) can be continuously changed, but the number of light-off areas is limited to one. In the LED array method, it is possible to set a plurality of extinguishing areas, but the width of the extinguishing area is limited by the irradiation width of the LED chip, so that the extinguishing area is discrete.
　本出願人は、これらの問題点を解決可能なＡＤＢ方式として、スキャン方式を提案している（特許文献２、３参照）。スキャン方式とは、回転するリフレクタ（ブレードミラー）に光を入射し、リフレクタの回転位置に応じた角度で入射光を反射して反射光を車両前方で走査しつつ、光源の点消灯を、リフレクタの回転位置に応じて変化させることで、車両前方に、所望の配光パターンを形成するものである。 The applicant has proposed a scanning method as an ADB method that can solve these problems (see Patent Documents 2 and 3). The scan method is to incident light on a rotating reflector (blade mirror), reflect the incident light at an angle according to the rotation position of the reflector, scan the reflected light in front of the vehicle, and turn on and off the light source. A desired light distribution pattern is formed in front of the vehicle by changing the light distribution pattern according to the rotation position of the vehicle.
　特許文献３に記載のスキャン方式では、１スキャンの間、光源に流す駆動電流の電流量を一定に保ちつつ、光源の点消灯（オン、オフ）を時分割で切り替える。そのため所定のエリアを遮光するグレアフリー機能の実現は容易であったが、照射領域の照度は実質的に一定に制約されていた。 In the scan method described in Patent Document 3, the light source is turned on and off (on and off) in a time-division manner while keeping the amount of drive current flowing through the light source constant during one scan. Therefore, it was easy to realize a glare-free function that shields a predetermined area from light, but the illuminance in the irradiation area was restricted to a substantially constant level.
　特許文献４には、スキャン方式の車両用灯具による具体的な配光の形成手法が開示される。この技術では、複数チャンネルの光源により配光が形成される。複数チャンネルの光源はそれぞれ、水平方向の一部の範囲を受け持っており、各光源のスキャン範囲は、他の光源のスキャン範囲と一部がオーバーラップしつつ、水平方向にシフトしたものとなっている。各光源の光量は、いわゆるＤＣ調光（アナログ調光）によって制御され、応答速度の制約から１スキャン単位で可変である。この灯具では、各走査位置の照度を、複数の光源のオン、オフ、および光量の組み合わせにより制御でき、グレアフリー機能以外の多様な配光パターン（たとえば電子スイブルなど）に対応するようになっている。 Patent Document 4 discloses a specific method for forming a light distribution using a scanning type vehicle lamp. In this technique, a light distribution is formed by a multi-channel light source. Each of the multi-channel light sources is responsible for a part of the horizontal range, and the scan range of each light source is shifted horizontally while partially overlapping the scan range of the other light sources. There is. The amount of light of each light source is controlled by so-called DC dimming (analog dimming), and is variable in units of one scan due to the limitation of response speed. With this lamp, the illuminance at each scanning position can be controlled by combining multiple light sources on, off, and the amount of light, and it is now compatible with various light distribution patterns other than the glare-free function (for example, electronic swivel). There is.
特開２００８－２０５３５７号公報Japanese Unexamined Patent Publication No. 2008-205357 特開２０１２－２２４３１７号公報Japanese Unexamined Patent Publication No. 2012-224317 特開２０１０－６１０９号公報Japanese Unexamined Patent Publication No. 2010-6109 特開２０１８－１８７９７９号公報Japanese Unexamined Patent Publication No. 2018-187979
　特許文献４の技術では、１つの配光を形成するために、多くのチャンネルの光源および点灯回路を必要としており、構造が複雑であり、また所望の配光を形成するための光源の制御も複雑であった。 The technique of Patent Document 4 requires light sources and lighting circuits of many channels to form one light distribution, has a complicated structure, and also controls the light source to form a desired light distribution. It was complicated.
　本開示は係る課題に鑑みてなされたものであり、そのある態様の例示的な目的のひとつは、グレアフリー機能以外の多様な配光パターンを生成可能な車両用灯具の提供にある。 The present disclosure has been made in view of the above problems, and one of the exemplary purposes of the embodiment is to provide a vehicle lamp capable of generating various light distribution patterns other than the glare-free function.
　本開示のある態様は、カメラとともに使用される車両用灯具に関する。車両用灯具は、半導体光源を含み、半導体光源の出射光にもとづく瞬時照射スポットを配光の水平方向に走査する走査型光源と、走査型光源の走査と同期して、各走査位置における半導体光源の光量をパルス変調により多階調で調光可能な点灯回路と、を備える。瞬時照射スポットの水平幅をθＳＰＯＴ、全スキャン角をθＳＣＡＮ、走査周期をＴＳＣＡＮとするとき、パルス変調の周期ＴＰＷＭは、
　ＴＰＷＭ＜Ａ×（θＳＰＯＴ／θＳＣＡＮ）×ＴＳＣＡＮを満たす。Ａは、Ａ≦１の定数である。 One aspect of the present disclosure relates to a vehicle lamp used with a camera. Vehicle lighting fixtures include a semiconductor light source, a scanning light source that scans an instantaneous irradiation spot based on the emitted light of the semiconductor light source in the horizontal direction of the light distribution, and a semiconductor light source at each scanning position in synchronization with scanning of the scanning light source. It is equipped with a lighting circuit capable of dimming the amount of light in multiple gradations by pulse modulation. When the horizontal width of the instantaneous irradiation spot is θ SPOT , the total scan angle is θ SCAN , and the scan cycle is T SCAN , the pulse modulation cycle T PWM is
T PWM <A × (θ SPOT / θ SCAN ) × T SCAN is satisfied. A is a constant of A ≦ 1.
　本開示のある態様は、カメラとともに使用される車両用灯具に関する。車両用灯具は、半導体光源を含み、半導体光源の出射光にもとづく瞬時照射スポットを配光の水平方向に走査する走査型光源と、走査型光源の走査と同期して、各走査位置における半導体光源の光量をパルス変調により多階調で調光可能な点灯回路と、を備える。瞬時照射スポットの水平幅をθＳＰＯＴ、スキャン速度をｖθとするとき、パルス変調の周期ＴＰＷＭは、
　ＴＰＷＭ＜θＳＰＯＴ／ｖθ
を満たす。Ａは、Ａ≦１の定数である。 One aspect of the present disclosure relates to a vehicle lamp used with a camera. Vehicle lighting fixtures include a semiconductor light source, a scanning light source that scans an instantaneous irradiation spot based on the emitted light of the semiconductor light source in the horizontal direction of the light distribution, and a semiconductor light source at each scanning position in synchronization with scanning of the scanning light source. It is equipped with a lighting circuit capable of dimming the amount of light in multiple gradations by pulse modulation. When the horizontal width of the instantaneous irradiation spot is θ SPOT and the scan speed is v θ , the pulse modulation cycle T PWM is
T PWM <θ SPOT / v θ
Meet. A is a constant of A ≦ 1.
　なお、以上の構成要素を任意に組み合わせたもの、構成要素や表現を、方法、装置、システムなどの間で相互に置換したものもまた、本発明あるいは本開示の態様として有効である。さらに、この項目（課題を解決するための手段）の記載は、本発明の欠くべからざるすべての特徴を説明するものではなく、したがって、記載されるこれらの特徴のサブコンビネーションも、本発明たり得る。 It should be noted that an arbitrary combination of the above components and a method in which the components and expressions are mutually replaced between methods, devices, systems and the like are also effective as aspects of the present invention or the present disclosure. Furthermore, the description of this item (means for solving the problem) does not explain all the essential features of the present invention, and therefore subcombinations of these features described may also be the present invention. ..
　本開示のある態様によれば、スキャン方式の車両用灯具において、グレアフリー機能以外の多様な配光パターンを生成できる。 According to an aspect of the present disclosure, it is possible to generate various light distribution patterns other than the glare-free function in a scanning type vehicle lamp.
実施形態１に係る車両用灯具を示す図である。It is a figure which shows the lamp for vehicle which concerns on Embodiment 1. FIG. 図２（ａ）、（ｂ）は、車両用灯具よるグレアフリー配光の形成を説明する図である。2 (a) and 2 (b) are diagrams illustrating the formation of glare-free light distribution by vehicle lamps. 図３（ａ）、（ｂ）は、車両用灯具よる部分減光配光の形成を説明する図である。3 (a) and 3 (b) are diagrams illustrating the formation of a partially dimmed light distribution by a vehicle lamp. 図４（ａ）、（ｂ）は、車両用灯具による電子スイブルを説明する図である。4 (a) and 4 (b) are diagrams illustrating an electronic swivel by a vehicle lamp. 比較技術に係る車両用灯具を示す図である。It is a figure which shows the lamp for a vehicle which concerns on the comparative technique. 比較技術に係る車両用灯具による配光形成を説明する図である。It is a figure explaining the light distribution formation by the lamp for vehicle which concerns on the comparative technique. 点灯回路の構成例を示すブロック図である。It is a block diagram which shows the structural example of a lighting circuit. ＬＥＤドライバの構成例を示す回路図である。It is a circuit diagram which shows the structural example of the LED driver. ＬＥＤドライバの別の構成例を示す回路図である。It is a circuit diagram which shows another configuration example of the LED driver. ＬＥＤドライバのさらに別の構成例を示す回路図である。It is a circuit diagram which shows the further structural example of the LED driver. 実施形態２に係る車両用灯具を示す図である。It is a figure which shows the lamp for vehicle which concerns on Embodiment 2. 図１１の点灯回路の構成例を示すブロック図である。It is a block diagram which shows the structural example of the lighting circuit of FIG. 実施形態に係る車両用灯具を示す図である。It is a figure which shows the lamp for vehicle which concerns on embodiment. 瞬時照射スポットの強度分布の一例を示す図である。It is a figure which shows an example of the intensity distribution of the instantaneous irradiation spot. ＰＷＭ周波数を変化させたときの、配光パターンを示す図である。It is a figure which shows the light distribution pattern when the PWM frequency is changed. 瞬時照射スポットの強度分布の一例を示す図である。It is a figure which shows an example of the intensity distribution of the instantaneous irradiation spot. ＰＷＭ周波数を変化させたときの、配光パターンを示す図である。It is a figure which shows the light distribution pattern when the PWM frequency is changed.
（実施形態の概要）
　本開示のいくつかの例示的な実施形態の概要を説明する。この概要は、後述する詳細な説明の前置きとして、実施形態の基本的な理解を目的として、１つまたは複数の実施形態のいくつかの概念を簡略化して説明するものであり、発明あるいは開示の広さを限定するものではない。またこの概要は、考えられるすべての実施形態の包括的な概要ではなく、実施形態の欠くべからざる構成要素を限定するものではない。便宜上、「一実施形態」は、本明細書に開示するひとつの実施形態（実施例や変形例）または複数の実施形態（実施例や変形例）を指すものとして用いる場合がある。 (Outline of Embodiment)
Some exemplary embodiments of the present disclosure will be outlined. This overview simplifies and describes some concepts of one or more embodiments for the purpose of basic understanding of embodiments, as a prelude to the detailed description described below, and is an invention or disclosure. It does not limit the size. Also, this overview is not a comprehensive overview of all possible embodiments and does not limit the essential components of the embodiments. For convenience, "one embodiment" may be used to refer to one embodiment (examples or modifications) or a plurality of embodiments (examples or modifications) disclosed herein.
　一実施形態に係る車両用灯具は、カメラとともに使用される。車両用灯具は、半導体光源を含み、半導体光源の出射光にもとづく瞬時照射スポットを配光の水平方向に走査する走査型光源と、走査型光源の走査と同期して、各走査位置における半導体光源の光量をパルス変調により多階調で調光可能な点灯回路と、を備える。 The vehicle lamp according to the embodiment is used together with the camera. Vehicle lighting fixtures include a semiconductor light source, a scanning light source that scans an instantaneous irradiation spot based on the emitted light of the semiconductor light source in the horizontal direction of the light distribution, and a semiconductor light source at each scanning position in synchronization with scanning of the scanning light source. It is equipped with a lighting circuit capable of dimming the amount of light in multiple gradations by pulse modulation.
　この構成によれば、パルス変調を採用することで、１走査周期内において、走査位置に応じて、光源の光量を高速に変化させることができる。したがって、１走査周期内で光量を一定とするＤＣ調光（アナログ調光）と比べて、１個の光源で形成できる配光のバリエーションが増える。これにより、従来に比べて、光源および点灯回路の個数を減らすことができ、あるいは、制御を簡略化できる。 According to this configuration, by adopting pulse modulation, the amount of light from the light source can be changed at high speed according to the scanning position within one scanning cycle. Therefore, as compared with DC dimming (analog dimming) in which the amount of light is constant within one scanning cycle, the variation of light distribution that can be formed by one light source increases. As a result, the number of light sources and lighting circuits can be reduced as compared with the conventional case, or control can be simplified.
　「パルス変調」は、パルス幅変調（ＰＷＭ）のほか、パルス周波数変調（ＰＦＭ）やパルス密度変調（ＰＤＭ）などを含み、光源に流れる駆動電流を高速にスイッチングし、駆動電流の時間平均値を変化させる変調方式を含みうる。 "Pulse modulation" includes pulse width modulation (PWM), pulse frequency modulation (PFM), pulse density modulation (PDM), etc., and switches the drive current flowing through the light source at high speed to obtain the time average value of the drive current. It may include varying modulation schemes.
　走査型の車両用灯具をカメラとともに使用する場合、車両用灯具の走査周波数ｆＳＣＡＮが、カメラのフレームレートｆＦＲＡＭＥより高くないと、カメラが撮影した画像に縞が移りこむ可能性がある。そのため、走査周波数ｆＳＣＡＮは、フレームレートｆＦＲＡＭＥより高く定められ、言い換えると走査周期ＴＳＣＡＮ（１／ｆＳＣＡＮ）は、撮像周期１／ｆＦＲＡＭＥより短く定められる。 When a scanning vehicle lamp is used together with a camera, if the scanning frequency f SCAN of the vehicle lamp is not higher than the frame rate f FRAME of the camera, stripes may be transferred to the image taken by the camera. Therefore, the scanning frequency f SCAN is set higher than the frame rate f FRAME , in other words, the scanning cycle T SCAN (1 / f SCAN ) is set shorter than the imaging cycle 1 / f FRAME .
　本発明者らは、走査とパルス調光を併用する場合に、パルス変調の周期ＴＰＷＭによっては、カメラの画像に縞が写り込むことを認識するに至った。縞が写り込むと、画像認識の精度を低下させるなどの問題が生ずる。 The present inventors have come to recognize that when scanning and pulse dimming are used in combination, fringes are reflected in the image of the camera depending on the pulse modulation cycle T PWM . When stripes are reflected, problems such as deterioration of image recognition accuracy occur.
　瞬時照射スポットは、ある有限の幅θＳＰＯＴを有している。瞬時照射スポットが走査される角度（全スキャン角）がθＳＣＡＮであるとき、瞬時照射スポットが、θＳＰＯＴ移動するのに要する通過時間τは、τ＝（θＳＰＯＴ／θＳＣＡＮ）×ＴＳＣＡＮとなる。 The instantaneous irradiation spot has a certain finite width θ SPOT . When the angle at which the instantaneous irradiation spot is scanned (total scan angle) is θ SCAN , the transit time τ required for the instantaneous irradiation spot to move θ SPOT is τ = (θ SPOT / θ SCAN ) × T SCAN . Become.
　パルス変調の周期ＴＰＷＭが、通過時間τより長いか、それと同程度のオーダーの場合に、スクリーン上に明暗が発生し、カメラの画像に縞として写り込むことを認識した。 It was recognized that when the pulse modulation cycle T PWM is longer than or on the order of the transit time τ, light and darkness occurs on the screen and appears as stripes in the camera image.
　この問題を解決するために、一実施形態において、瞬時照射スポットの水平幅をθＳＰＯＴ、全スキャン角をθＳＣＡＮ、走査周期をＴＳＣＡＮとするとき、パルス変調の周期ＴＰＷＭは、
　ＴＰＷＭ＜Ａ×（θＳＰＯＴ／θＳＣＡＮ）×ＴＳＣＡＮを満たしてもよい。Ａは、Ａ≦１の定数である。これにより、縞の写り込みを抑制できる。 In order to solve this problem, in one embodiment, when the horizontal width of the instantaneous irradiation spot is θ SPOT , the total scan angle is θ SCAN , and the scan cycle is T SCAN , the pulse modulation cycle T PWM is set.
T PWM <A × (θ SPOT / θ SCAN ) × T SCAN may be satisfied. A is a constant of A ≦ 1. This makes it possible to suppress the reflection of stripes.
　瞬時照射スポットの速度ｖθは、ｖθ＝θＳＣＡＮ／ＴＳＣＡＮであるから、通過時間τは、θＳＰＯＴ／ｖθと書き換えられる。したがって一実施形態において、瞬時照射スポットの水平幅をθＳＰＯＴ、スキャン速度をｖθとするとき、パルス変調の周期ＴＰＷＭは、
　ＴＰＷＭ＜Ａ×θＳＰＯＴ／ｖθ
を満たしてもよい。Ａは、Ａ≦１の定数である。これにより、縞の写り込みを抑制できる。 Since the velocity v θ of the instantaneous irradiation spot is v θ = θ SCAN / T SCAN , the transit time τ is rewritten as θ SPOT / v θ . Therefore, in one embodiment, when the horizontal width of the instantaneous irradiation spot is θ SPOT and the scan speed is v θ , the pulse modulation cycle T PWM is set.
T PWM <A × θ SPOT / v θ
May be satisfied. A is a constant of A ≦ 1. This makes it possible to suppress the reflection of stripes.
　定数Ａは、瞬時照射スポットの強度分布に応じて規定することができる。たとえば強度分布が矩形のビームを想定する場合、Ａ≒１であり、ガウシアン分布の場合には、Ａはさらに小さく定める必要があり、たとえばＡ≦０．５となる。たとえばＡ≦０．２とすると、さまざまな強度分布において、縞の写り込みを抑制できる。 The constant A can be defined according to the intensity distribution of the instantaneous irradiation spot. For example, when assuming a beam having a rectangular intensity distribution, A≈1, and in the case of a Gaussian distribution, A needs to be set smaller, for example, A ≦ 0.5. For example, when A ≦ 0.2, it is possible to suppress the reflection of stripes in various intensity distributions.
　一実施形態において、走査型光源は、半導体光源に加えて、半導体光源の出射光を受け、所定の周期運動を繰り返すことによりその反射光を車両前方で走査する反射体をさらに含んでもよい。点灯回路は、反射体の運動と同期して、パルス変調の制御波形を生成し、制御波形に応じて半導体光源に供給する駆動電流をスイッチングしてもよい。 In one embodiment, the scanning light source may further include, in addition to the semiconductor light source, a reflector that receives the emitted light of the semiconductor light source and scans the reflected light in front of the vehicle by repeating a predetermined periodic motion. The lighting circuit may generate a control waveform of pulse modulation in synchronization with the motion of the reflector, and may switch the drive current supplied to the semiconductor light source according to the control waveform.
　一実施形態において、点灯回路は、半導体光源と直列に設けられるシリーズスイッチと、シリーズスイッチと半導体光源の直列接続回路に接続される定電流ドライバと、を備えてもよい。点灯回路は、走査位置に応じたデューティサイクルで、シリーズスイッチをスイッチングしてもよい。 In one embodiment, the lighting circuit may include a series switch provided in series with the semiconductor light source and a constant current driver connected to the series connection circuit of the series switch and the semiconductor light source. The lighting circuit may switch the series switch in a duty cycle according to the scanning position.
　従来技術（特許文献４）では、２個の半導体光源を直列に接続し、各半導体光源と並列にバイパススイッチを設ける構成が採られていた。この構成では、１個のバイパススイッチを走査周波数よりも十分高い周波数でスイッチングすると、他方の半導体光源にその影響が及ぶこととなる。これに対して、半導体光源ごとにシリーズスイッチによって個別に駆動することにより、あるチャンネルの駆動が、他のチャンネルに及ぼす影響を排除できる。 In the prior art (Patent Document 4), two semiconductor light sources are connected in series, and a bypass switch is provided in parallel with each semiconductor light source. In this configuration, switching one bypass switch at a frequency sufficiently higher than the scanning frequency will affect the other semiconductor light source. On the other hand, by individually driving each semiconductor light source with a series switch, it is possible to eliminate the influence of driving one channel on other channels.
　一実施形態において、定電流ドライバは、スイッチングコンバータと、スイッチングコンバータの出力電流の検出値が、所定の目標値に近づくように、スイッチングコンバータを駆動するコンバータコントローラと、を含んでもよい。 In one embodiment, the constant current driver may include a switching converter and a converter controller that drives the switching converter so that the detected value of the output current of the switching converter approaches a predetermined target value.
（実施形態）
　以下、本開示を好適な実施の形態をもとに図面を参照しながら説明する。各図面に示される同一または同等の構成要素、部材、処理には、同一の符号を付するものとし、適宜重複した説明は省略する。また、実施の形態は、開示を限定するものではなく例示であって、実施の形態に記述されるすべての特徴やその組み合わせは、必ずしも開示の本質的なものであるとは限らない。 (Embodiment)
Hereinafter, the present disclosure will be described with reference to the drawings based on the preferred embodiments. The same or equivalent components, members, and processes shown in the drawings shall be designated by the same reference numerals, and duplicate description thereof will be omitted as appropriate. Further, the embodiment is not limited to the disclosure but is an example, and all the features and combinations thereof described in the embodiment are not necessarily essential to the disclosure.
　本明細書において、「部材Ａが、部材Ｂと接続された状態」とは、部材Ａと部材Ｂが物理的に直接的に接続される場合のほか、部材Ａと部材Ｂが、それらの電気的な接続状態に実質的な影響を及ぼさない、あるいはそれらの結合により奏される機能や効果を損なわせない、その他の部材を介して間接的に接続される場合も含む。 In the present specification, the "state in which the member A is connected to the member B" means that the member A and the member B are physically directly connected, and the member A and the member B are electrically connected to each other. It also includes cases of being indirectly connected via other members that do not substantially affect the connection state or impair the functions and effects performed by the combination thereof.
　同様に、「部材Ｃが、部材Ａと部材Ｂの間に設けられた状態」とは、部材Ａと部材Ｃ、あるいは部材Ｂと部材Ｃが直接的に接続される場合のほか、それらの電気的な接続状態に実質的な影響を及ぼさない、あるいはそれらの結合により奏される機能や効果を損なわせない、その他の部材を介して間接的に接続される場合も含む。 Similarly, "a state in which the member C is provided between the member A and the member B" means that the member A and the member C, or the member B and the member C are directly connected, and their electricity. It also includes cases of being indirectly connected via other members that do not substantially affect the connection state or impair the functions and effects performed by the combination thereof.
　また本明細書において、電圧信号、電流信号などの電気信号、あるいは抵抗、キャパシタなどの回路素子に付された符号は、必要に応じてそれぞれの電圧値、電流値、あるいは抵抗値、容量値を表すものとする。 Further, in the present specification, the reference numerals attached to electric signals such as voltage signals and current signals, or circuit elements such as resistors and capacitors have their respective voltage values, current values, resistance values, and capacitance values as necessary. It shall be represented.
　図１は、実施形態１に係る車両用灯具１００Ａを示す図である。図１の車両用灯具１００Ａは、スキャン方式のＡＤＢ機能を有し、車両前方に多様な配光パターンを形成する。車両用灯具１００Ａは主として、走査型光源２００Ａ、点灯回路３００Ａおよび配光コントローラ４００を備える。 FIG. 1 is a diagram showing a vehicle lamp 100A according to the first embodiment. The vehicle lamp 100A of FIG. 1 has a scan-type ADB function and forms various light distribution patterns in front of the vehicle. The vehicle lamp 100A mainly includes a scanning light source 200A, a lighting circuit 300A, and a light distribution controller 400.
　配光コントローラ４００は、カメラやＬｉＤＡＲ（Light Detection and Ranging、Laser Imaging Detection and Ranging）などのセンサからの情報（センサ情報）Ｓ１、車速やステアリング角などの情報（車両情報）Ｓ２などを受け、配光パターンを決定する。配光コントローラ４００は、ランプボディ内に収容されてもよいし、車両側に設けられてもよい。配光コントローラ４００は、配光パターンを指示する情報（配光パターン情報）Ｓ３を車両用灯具１００に送信する。配光コントローラ４００を、ＡＤＢ用ＥＣＵ（Electronic Control Unit）とも称する。 The light distribution controller 400 receives and distributes information (sensor information) S1 and information (vehicle information) S2 such as vehicle speed and steering angle from sensors such as cameras and LiDAR (Light Detection and Ringing, Laser Imaging Detection and Ringing). Determine the light pattern. The light distribution controller 400 may be housed in the lamp body or may be provided on the vehicle side. The light distribution controller 400 transmits information (light distribution pattern information) S3 indicating a light distribution pattern to the vehicle lamp 100. The light distribution controller 400 is also referred to as an ADB ECU (Electronic Control Unit).
　走査型光源２００Ａは、光源ユニット２１０Ａ、走査光学系２２０、投影光学系２３０を備える。光源ユニット２１０Ａは、１個の半導体光源２１２や図示しないヒートシンクを含む。半導体光源２１２には、ＬＥＤ（発光ダイオード）あるいはレーザダイオードなどを用いることができる。走査光学系２２０は、半導体光源２１２の出射光（ビーム）ＢＭを車両前方で走査する。 The scanning light source 200A includes a light source unit 210A, a scanning optical system 220, and a projection optical system 230. The light source unit 210A includes one semiconductor light source 212 and a heat sink (not shown). An LED (light emitting diode), a laser diode, or the like can be used as the semiconductor light source 212. The scanning optical system 220 scans the emitted light (beam) BM of the semiconductor light source 212 in front of the vehicle.
　本実施形態において走査光学系２２０は、モータ２２２および１枚あるいは複数Ｍ枚（この例では２枚）のブレードミラー２２４＿１，２２４＿２を備える。Ｍ枚（Ｍ≧２）のブレードミラーは、３６０／Ｍ°、ずれた位置に取り付けられ、この例では、２枚のブレードミラーが１８０°ずれた位置に取り付けられている。 In the present embodiment, the scanning optical system 220 includes a motor 222 and one or a plurality of M (two in this example) blade mirrors 224_1224_2. The M blade mirrors (M ≧ 2) are mounted at 360 / M ° offset positions, and in this example, the two blade mirrors are mounted at 180 ° offset positions.
　半導体光源２１２の光軸は、その出射ビームＢＭが、Ｍ枚のブレードミラーのうちの１枚に照射されるように向けられている。 The optical axis of the semiconductor light source 212 is directed so that the emitted beam BM illuminates one of the M blade mirrors.
　ある時刻においてブレードミラー２２４への入射光ＢＭは、ブレードミラー２２４の位置（ロータの回転角）に応じた反射角で反射し、車両前方の仮想鉛直スクリーン９００上に瞬時照射スポットＳＰＴを形成する。瞬時照射スポットＳＰＴは、水平方向（Ｈ方向）に幅Δｖ、垂直方向（Ｖ方向）に幅Δｈを有している。ブレードミラー２２４が回転することで反射角、すなわち反射ビームＢＭｒの出射方向が変化し、瞬時照射スポットＳＰＴの水平方向（Ｈ方向）の位置（走査位置）が移動する。この動作を高速に、たとえば５０Ｈｚ以上で繰り返すことで車両前方には、配光パターンＰＴＮが形成される。 At a certain time, the incident light BM on the blade mirror 224 is reflected at a reflection angle corresponding to the position of the blade mirror 224 (rotation angle of the rotor), and an instantaneous irradiation spot SPT is formed on the virtual vertical screen 900 in front of the vehicle. The instantaneous irradiation spot SPT has a width Δv in the horizontal direction (H direction) and a width Δh in the vertical direction (V direction). The rotation of the blade mirror 224 changes the reflection angle, that is, the emission direction of the reflected beam BMr, and the horizontal (H direction) position (scanning position) of the instantaneous irradiation spot SPT moves. By repeating this operation at high speed, for example, at 50 Hz or higher, a light distribution pattern PTN is formed in front of the vehicle.
　本実施形態において、ひとつのビームＢＭが形成する配光パターンＰＴＮは、車両用灯具１００Ａの水平方向の全範囲－θＭＡＸ～＋θＭＡＸに広がっている。すなわち走査型光源２００Ａは、反射ビームＢＭｒを、水平方向の全範囲にわたり走査する。たとえばθＭＡＸは２０～２５°程度である。なお全範囲とは、スキャン照射可能な全範囲であり、スキャン以外の光源により照射される範囲は含まない。 In the present embodiment, the light distribution pattern PTN formed by one beam BM extends over the entire horizontal range of the vehicle lamp 100A to −θMAX to + θMAX . That is, the scanning light source 200A scans the reflected beam BMr over the entire horizontal range. For example, θ MAX is about 20 to 25 °. The entire range is the entire range that can be irradiated by scanning, and does not include the range irradiated by a light source other than scanning.
　点灯回路３００Ａは、配光パターン情報Ｓ３が指示する配光パターンが得られるように、走査型光源２００Ａの走査と同期して、各走査位置における半導体光源２１２の光量、すなわちビームＢＭの強度を、パルス変調により多階調で調光する。本実施形態では、ＰＷＭ（パルス幅変調）によって、半導体光源２１２に流れる駆動電流ＩＬＥＤの平均量を変化させ、半導体光源２１２の光量を変化させる（ＰＷＭ調光）。ＰＷＭ周波数は、走査周波数よりも十分に高く定められ、たとえば数ｋＨｚ～数百ｋＨｚとすることが望ましい。 The lighting circuit 300A determines the amount of light of the semiconductor light source 212 at each scanning position, that is, the intensity of the beam BM, in synchronization with the scanning of the scanning light source 200A so that the light distribution pattern indicated by the light distribution pattern information S3 can be obtained. Dimming with multiple gradations by pulse modulation. In the present embodiment, the average amount of drive current I LEDs flowing through the semiconductor light source 212 is changed by PWM (pulse width modulation), and the amount of light of the semiconductor light source 212 is changed (PWM dimming). The PWM frequency is set sufficiently higher than the scanning frequency, and it is desirable that the PWM frequency is, for example, several kHz to several hundred kHz.
　なお点灯回路３００Ａは、走査周期、またはそれより長い制御周期で、電流ＩＯＵＴの電流量を変化させてもよい。つまりＰＷＭ調光とＤＣ調光を併用してもよい。以上が車両用灯具１００Ａの構成である。続いてその動作を説明する。 The lighting circuit 300A may change the amount of current I OUT in a scanning cycle or a control cycle longer than that. That is, PWM dimming and DC dimming may be used together. The above is the configuration of the vehicle lamp 100A. Next, the operation will be described.
　図２（ａ）、（ｂ）は、車両用灯具１００Ａよるグレアフリー配光の形成を説明する図である。図２のグレアフリー配光９１０は、遮光部分９１２と、照射部分９１４，９１６を含んでいる。図２（ａ）は仮想鉛直スクリーン上の配光を、図２（ｂ）は、図２（ａ）の配光に対応する車両用灯具１００Ａの動作波形を示す。なお本明細書において参照する波形図やタイムチャートの縦軸および横軸は、理解を容易とするために適宜拡大、縮小したものであり、また示される各波形も、理解の容易のために簡略化され、あるいは誇張もしくは強調されている。 2 (a) and 2 (b) are diagrams illustrating the formation of glare-free light distribution by the vehicle lamp 100A. The glare-free light distribution 910 of FIG. 2 includes a light-shielding portion 912 and an irradiation portion 914,916. FIG. 2A shows the light distribution on the virtual vertical screen, and FIG. 2B shows the operation waveform of the vehicle lamp 100A corresponding to the light distribution of FIG. 2A. The vertical and horizontal axes of the waveform charts and time charts referred to in the present specification are appropriately enlarged or reduced for easy understanding, and each waveform shown is also simplified for easy understanding. It is made, or exaggerated or emphasized.
　たとえば点灯回路３００Ａは、照射部分９１４，９１６に対応する区間において、半導体光源２１２の駆動電流ＩＬＥＤのデューティサイクルを非ゼロの値（この例では１００％の一定値）とし、遮光部分９１２に対応する区間において、駆動電流ＩＬＥＤのデューティサイクルを０％とする。 For example, the lighting circuit 300A sets the duty cycle of the drive current I LED of the semiconductor light source 212 to a non-zero value (100% constant value in this example) in the section corresponding to the irradiation portions 914 and 916, and corresponds to the light shielding portion 912. In this section, the duty cycle of the drive current I LED is set to 0%.
　図３（ａ）、（ｂ）は、車両用灯具１００Ａよる部分減光配光の形成を説明する図である。図３（ａ）は仮想鉛直スクリーン上の配光の水平方向の照度分布を示し、図３（ｂ）は、図３（ａ）の配光に対応する車両用灯具１００Ａの動作波形を示す。図３（ａ）に示す部分減光配光９２０は、２個の減光部分９２２，９２４と、３個の非減光部分９２６，９２７，９２８を含んでいる。 3 (a) and 3 (b) are diagrams illustrating the formation of a partially dimmed light distribution by the vehicle lamp 100A. FIG. 3A shows the horizontal illuminance distribution of the light distribution on the virtual vertical screen, and FIG. 3B shows the operation waveform of the vehicle lamp 100A corresponding to the light distribution of FIG. 3A. The partial dimming distribution 920 shown in FIG. 3A includes two dimming portions 922,924 and three non-dimming portions 926,927,928.
　たとえば点灯回路３００Ａは、非減光部分（照射部分）９２６，９２７，９２８に対応する区間において、半導体光源２１２の駆動電流ＩＬＥＤのデューティサイクルを１００％に固定し、減光部分９２２，９２４に対応する区間において、駆動電流ＩＬＥＤのデューティサイクルをそれぞれ、５０％、２５％とする。この車両用灯具１００Ａによれば、単一の半導体光源に流れる駆動電流ＩＬＥＤをＰＷＭ制御することにより、部分減光を実現できる。 For example, in the lighting circuit 300A, the duty cycle of the drive current I LED of the semiconductor light source 212 is fixed to 100% in the section corresponding to the non-dimming portion (irradiation portion) 926,927,928, and the duty cycle is fixed to the dimming portion 922,924. In the corresponding section, the duty cycle of the drive current I LED is 50% and 25%, respectively. According to the vehicle lamp 100A, partial dimming can be realized by PWM-controlling the drive current I LED flowing through a single semiconductor light source.
　図４（ａ）、（ｂ）は、車両用灯具１００Ａによる電子スイブルを説明する図である。図４（ａ）は、中央が最も明るい配光を、図４（ｂ）は、右側が最も明るい配光を示す。この車両用灯具１００Ａによれば、単一の半導体光源に流れる駆動電流ＩＬＥＤをＰＷＭ制御することにより、電子スイブル機能を実現できる。 4 (a) and 4 (b) are diagrams illustrating an electronic swivel by a vehicle lamp 100A. FIG. 4A shows the brightest light distribution in the center, and FIG. 4B shows the brightest light distribution on the right side. According to the vehicle lamp 100A, the electronic swivel function can be realized by PWM-controlling the drive current I LED flowing through a single semiconductor light source.
　以上が車両用灯具１００Ａの動作である。車両用灯具１００Ａの利点は、比較技術との対比によって一層明確となる。そこで比較技術について説明する。図５は、比較技術に係る車両用灯具１００Ｒを示す図である。 The above is the operation of the vehicle lamp 100A. The advantages of the vehicle lamp 100A will be further clarified by comparison with the comparative technique. Therefore, the comparative technique will be described. FIG. 5 is a diagram showing a vehicle lamp 100R according to a comparative technique.
　比較技術に係る車両用灯具１００Ｒにおいて、光源ユニット２１０Ｒは複数の半導体光源２１２＿１～２１２＿Ｎを備える。半導体光源２１２＿１～２１２＿Ｎそれぞれの出射ビームＢＭ１～ＢＭＮはそれぞれ、仮想鉛直スクリーン９００上の、水平方向の異なる範囲を走査され、出射ビームＢＭ１～ＢＭＮの走査により、複数の個別配光パターンＰＴＮ１～ＰＴＮＮが形成される。車両用灯具１００Ｒが形成する配光は、複数の個別配光パターンＰＴＮ１～ＰＴＮＮの重ね合わせである。 In the vehicle lamp 100R according to the comparative technique, the light source unit 210R includes a plurality of semiconductor light sources 212_1 to 212_N. Each of the emission beams BM 1 to BM N of the semiconductor light sources 212_1 to 212_N is scanned in different horizontal ranges on the virtual vertical screen 900, and a plurality of individual light distribution patterns are scanned by scanning the emission beams BM 1 to BM N. PTN 1 to PTN N are formed. The light distribution formed by the vehicle lamp 100R is a superposition of a plurality of individual light distribution patterns PTN 1 to PTN N.
　点灯回路３００Ｒは、複数の半導体光源２１２＿１～２１２＿Ｎそれぞれに、駆動電流ＩＬＥＤ１～ＩＬＥＤＮを供給する。点灯回路３００Ｒは、１周期内で、駆動電流ＩＬＥＤ１～ＩＬＥＤＮそれぞれを、オン、オフすることが可能である。また点灯回路３００Ｒは、ＤＣ調光によって、駆動電流ＩＬＥＤ１～ＩＬＥＤＮそれぞれのオン期間における電流量を制御可能であるが、電流量は、１走査ごとにしか切りかえることができない。 The lighting circuit 300R supplies drive currents I LED1 to I LEDN to each of the plurality of semiconductor light sources 212_1 to 212_N. The lighting circuit 300R can turn on and off the drive currents I LED1 to I LEDN , respectively, within one cycle. Further, the lighting circuit 300R can control the amount of current during the on period of each of the drive currents I LED1 to I LEDN by DC dimming, but the amount of current can be switched only for each scan.
　図６は、比較技術に係る車両用灯具１００Ｒによる配光形成を説明する図である。ここではＮ＝６チャンネルとする。複数の個別配光パターンＰＴＮ１～ＰＴＮ６の照射幅が制御される。それらを重ね合わせることにより、この例では左前方が明るい配光パターンが形成される。 FIG. 6 is a diagram illustrating light distribution formation by the vehicle lamp 100R according to the comparative technique. Here, N = 6 channels. The irradiation widths of the plurality of individual light distribution patterns PTN 1 to PTN 6 are controlled. By superimposing them, a light distribution pattern with a bright left front is formed in this example.
　実施形態１に戻る。実施形態１に係る車両用灯具１００Ａによれば、パルス変調を採用することで、１走査周期内において、走査位置に応じて、光源の光量を高速に変化させることができる。したがって、１走査周期内で光量を一定とする従来のアナログ調光と比べて、１個の光源で形成できる配光のバリエーションが増える。これにより、従来に比べて、光源および点灯回路の個数を減らすことができ、あるいは、制御を簡略化できる。 Return to embodiment 1. According to the vehicle lamp 100A according to the first embodiment, by adopting pulse modulation, the light amount of the light source can be changed at high speed according to the scanning position within one scanning cycle. Therefore, as compared with the conventional analog dimming in which the amount of light is constant within one scanning cycle, the variation of the light distribution that can be formed by one light source increases. As a result, the number of light sources and lighting circuits can be reduced as compared with the conventional case, or control can be simplified.
　本開示は、図１のブロック図や回路図として把握され、図３～図４の波形図、あるいは上述の説明から導かれるさまざまな装置、回路に及ぶものであり、特定の構成に限定されるものではない。以下、本開示の範囲を狭めるためではなく、開示の本質や回路動作の理解を容易、明確化するために、より具体的な構成例を説明する。 The present disclosure is grasped as a block diagram and a circuit diagram of FIG. 1, and extends to various devices and circuits derived from the waveform diagrams of FIGS. 3 to 4 or the above description, and is limited to a specific configuration. It's not a thing. Hereinafter, a more specific configuration example will be described not to narrow the scope of the present disclosure but to facilitate and clarify the essence of the disclosure and the circuit operation.
　点灯回路３００Ａの具体的な構成例を説明する。図７は、点灯回路３００Ａの構成例を示すブロック図である。 A specific configuration example of the lighting circuit 300A will be described. FIG. 7 is a block diagram showing a configuration example of the lighting circuit 300A.
　配光コントローラ４００は、センサ情報Ｓ１や車両情報Ｓ２を受ける。配光コントローラ４００は、センサ情報Ｓ１にもとづいて、車両前方の状況、具体的には対向車、先行車の有無、歩行者の有無等を検出する。また配光コントローラ４００は、車両情報Ｓ２にもとづいて、現在の車速、操舵角などを検出する。配光コントローラ４００はこれらの情報にもとづいて、車両前方に照射すべき配光パターンを決定し、配光パターンを指示する情報（配光パターン情報）Ｓ３を、点灯回路３００Ａに送信する。 The light distribution controller 400 receives sensor information S1 and vehicle information S2. The light distribution controller 400 detects the situation in front of the vehicle, specifically, the presence / absence of an oncoming vehicle, a preceding vehicle, the presence / absence of a pedestrian, and the like based on the sensor information S1. Further, the light distribution controller 400 detects the current vehicle speed, steering angle, and the like based on the vehicle information S2. Based on these information, the light distribution controller 400 determines a light distribution pattern to be irradiated to the front of the vehicle, and transmits information (light distribution pattern information) S3 instructing the light distribution pattern to the lighting circuit 300A.
　点灯回路３００Ａは、配光パターン情報Ｓ３にもとづいてブレードミラー２２４の回転と同期しながら、ＰＷＭ調光により、半導体光源２１２の光量（輝度）を多階調で変化させる。たとえば点灯回路３００Ａは主として、位置検出器３０２、ＰＷＭ信号生成部３１０、定電流ドライバ（以下、ＬＥＤドライバという）３２０を備える。 The lighting circuit 300A changes the light amount (luminance) of the semiconductor light source 212 in multiple gradations by PWM dimming while synchronizing with the rotation of the blade mirror 224 based on the light distribution pattern information S3. For example, the lighting circuit 300A mainly includes a position detector 302, a PWM signal generation unit 310, and a constant current driver (hereinafter referred to as LED driver) 320.
　位置検出器３０２は、ブレードミラー２２４の位置、言い換えれば現在のビームの走査位置を検出するために設けられる。位置検出器３０２は、ブレードミラー２２４の所定の基準箇所が所定位置を通過するタイミングを示す位置検出信号Ｓ４を生成する。たとえば基準箇所は、２枚のブレードミラー２２４の端部（区切れ目）であってもよいし、各ブレードミラーの中央であってもよく、任意の箇所とすることができる。 The position detector 302 is provided to detect the position of the blade mirror 224, in other words, the scanning position of the current beam. The position detector 302 generates a position detection signal S4 indicating the timing at which the predetermined reference point of the blade mirror 224 passes the predetermined position. For example, the reference portion may be the end portion (separation) of the two blade mirrors 224, or may be the center of each blade mirror, and may be any location.
　ブレードミラー２２４を回転させるモータ２２２には、ホール素子が取り付けられていてもよい。この場合、ホール素子からのホール信号は、ロータの位置、すなわちブレードミラーの位置に応じた周期波形となる。位置検出器３０２は、ホール信号の極性が反転するタイミングを検出してもよく、具体的には一対のホール信号を比較するホールコンパレータで構成してもよい。 A Hall element may be attached to the motor 222 that rotates the blade mirror 224. In this case, the Hall signal from the Hall element has a periodic waveform corresponding to the position of the rotor, that is, the position of the blade mirror. The position detector 302 may detect the timing at which the polarity of the Hall signal is inverted, and specifically, may be configured by a Hall comparator that compares a pair of Hall signals.
　位置検出器３０２によるブレードミラー２２４の位置検出方法は、ホール素子を利用したものに限定されない。たとえば位置検出器３０２は、モータ２２２のロータの位置を検出する光学式、あるいはその他の方式のロータリーエンコーダを利用して、位置検出信号Ｓ４を生成してもよい。あるいは位置検出器３０２は、ブレードミラー２２４の裏側に設けられたフォトセンサと、ブレードミラー２２４の表面側からフォトセンサに向かって光を照射する位置検出用の光源と、を含んでもよい。そしてブレードミラー２２４に、スリットあるいはピンホールを設けてもよい。これにより、スリットあるいはピンホールが、フォトセンサの上を通過するタイミングを検出できる。スリットは、２枚のブレードミラー２２４の間隙であってもよい。また位置検出用の光源は、赤外線光源を利用してもよいし、半導体光源２１２であってもよい。このように位置検出器３０２の構成にはさまざまなバリエーションが存在しうる。 The position detection method of the blade mirror 224 by the position detector 302 is not limited to the one using a Hall element. For example, the position detector 302 may generate the position detection signal S4 by using an optical or other rotary encoder that detects the position of the rotor of the motor 222. Alternatively, the position detector 302 may include a photosensor provided on the back side of the blade mirror 224 and a light source for position detection that irradiates light from the surface side of the blade mirror 224 toward the photosensor. Then, the blade mirror 224 may be provided with a slit or a pinhole. This makes it possible to detect when the slit or pinhole passes over the photo sensor. The slit may be a gap between the two blade mirrors 224. Further, the light source for position detection may be an infrared light source or a semiconductor light source 212. As described above, there may be various variations in the configuration of the position detector 302.
　ＰＷＭ信号生成部３１０は、ブレードミラー２２４の運動と同期して、パルス調光信号ＰＷＭ＿ＤＩＭを生成する。パルス調光信号ＰＷＭ＿ＤＩＭの１走査周期のデューティサイクルは、配光パターンにもとづいて規定される。たとえばモータ２２２の回転数が６０００ｒｐｍ（１００Ｈｚ）であり、ブレードミラーが２枚である場合、走査周波数は、１００Ｈｚ×２＝２００Ｈｚとなり、走査周期は５ｍｓである。ＰＷＭ信号生成部３１０は、マイクロコントローラ３０４とソフトウェアプログラムの組み合わせで実装してもよいし、ハードウェアのみで実装してもよい。マイクロコントローラ３０４およびＬＥＤドライバ３２０は、一枚の基板上に搭載してもよいし、あるいは１つの筐体内に配置してもよい。 The PWM signal generation unit 310 generates a pulse dimming signal PWM_DIM in synchronization with the movement of the blade mirror 224. The duty cycle of one scan cycle of the pulse dimming signal PWM_DIM is defined based on the light distribution pattern. For example, when the rotation speed of the motor 222 is 6000 rpm (100 Hz) and the number of blade mirrors is two, the scanning frequency is 100 Hz × 2 = 200 Hz, and the scanning cycle is 5 ms. The PWM signal generation unit 310 may be implemented by combining the microcontroller 304 and the software program, or may be implemented only by hardware. The microcontroller 304 and the LED driver 320 may be mounted on one substrate or may be arranged in one housing.
　パルス調光信号ＰＷＭ＿ＤＩＭの周波数は、２００Ｈｚより高く定められ、たとえば数ｋＨｚ～数十ｋＨｚとすることができる。パルス調光信号ＰＷＭ＿ＤＩＭのデューティサイクルは、半導体光源２１２の光量を規定するものであり、デューティサイクルは、１ＰＷＭ周期ごとに設定可能であってもよいし、複数のＰＷＭ周期ごとに設定可能であってもよい。 The frequency of the pulse dimming signal PWM_DIM is set higher than 200 Hz, and can be, for example, several kHz to several tens of kHz. The duty cycle of the pulse dimming signal PWM_DIM defines the amount of light of the semiconductor light source 212, and the duty cycle may be set for each PWM cycle or may be set for each of a plurality of PWM cycles. It is also good.
　ＬＥＤドライバ３２０は半導体光源２１２に駆動電流ＩＬＥＤを供給する。駆動電流ＩＬＥＤの電流量は、所定の目標値に安定化されており、ＬＥＤドライバ３２０は、パルス調光信号ＰＷＭ＿ＤＩＭに応じて、駆動電流ＩＬＥＤをスイッチングする。 The LED driver 320 supplies a drive current I LED to the semiconductor light source 212. The current amount of the drive current I LED is stabilized to a predetermined target value, and the LED driver 320 switches the drive current I LED according to the pulse dimming signal PWM_DIM.
　図８は、ＬＥＤドライバ３２０の構成例（３２０Ａ）を示す回路図である。ＬＥＤドライバ３２０Ａは、降圧コンバータ３２２と、シリーズスイッチ３２３、ドライバ回路３２４を備える。シリーズスイッチ３２３と半導体光源２１２は直列に接続される。この例ではシリーズスイッチ３２３が半導体光源２１２のアノード側に挿入されるが、カソードと接地の間に挿入してもよい。 FIG. 8 is a circuit diagram showing a configuration example (320A) of the LED driver 320. The LED driver 320A includes a buck converter 322, a series switch 323, and a driver circuit 324. The series switch 323 and the semiconductor light source 212 are connected in series. In this example, the series switch 323 is inserted on the anode side of the semiconductor light source 212, but may be inserted between the cathode and the ground.
　降圧コンバータ３２２は、定電流出力のスイッチングコンバータであり、出力回路３２６およびコンバータコントローラ３２８を含む。出力回路３２６は、スイッチングトランジスタＭＨ、同期整流トランジスタＭＬ、インダクタＬ１、出力キャパシタＣ１を含む。コンバータコントローラ３２８は、シリーズスイッチ３２３がオンの期間に降圧コンバータ３２２の出力電流ＩＯＵＴが所定の目標量に近づくように、出力回路３２６のスイッチングトランジスタＭＨおよび同期整流トランジスタＭＬをスイッチング制御する。 The buck converter 322 is a constant current output switching converter and includes an output circuit 326 and a converter controller 328. The output circuit 326 includes a switching transistor MH, a synchronous rectifying transistor ML, an inductor L1, and an output capacitor C1. The converter controller 328 switches and controls the switching transistor MH and the synchronous rectifying transistor ML of the output circuit 326 so that the output current I OUT of the buck converter 322 approaches a predetermined target amount while the series switch 323 is on.
　コンバータコントローラ３２８の制御方式は特に限定されず、エラーアンプを用いたアナログコントローラ、ＰＩＤ（比例・積分・微分）補償器を含むデジタルコントローラ、あるいはヒステリシス制御のコントローラであってもよい。 The control method of the converter controller 328 is not particularly limited, and may be an analog controller using an error amplifier, a digital controller including a PID (proportional / integral / differential) compensator, or a hysteresis control controller.
　ドライバ回路３２４は、パルス調光信号ＰＷＭ＿ＤＩＭに応じてシリーズスイッチ３２３を駆動する。このドライバ回路３２４は、コンバータコントローラ３２８と同じＩＣに集積化されてもよい。 The driver circuit 324 drives the series switch 323 in response to the pulse dimming signal PWM_DIM. The driver circuit 324 may be integrated in the same IC as the converter controller 328.
　コンバータコントローラ３２８は、パルス調光信号ＰＷＭ＿ＤＩＭが、シリーズスイッチ３２３のオフを指示するオフレベルであるとき、スイッチングトランジスタＭＨおよび同期整流トランジスタＭＬのスイッチングを停止する。 The converter controller 328 stops the switching of the switching transistor MH and the synchronous rectifying transistor ML when the pulse dimming signal PWM_DIM is at the off level indicating the off of the series switch 323.
　図９は、ＬＥＤドライバ３２０の別の構成例（３２０Ｂ）を示す回路図である。ＬＥＤドライバ３２０Ｂは、降圧コンバータ３２２と、バイパススイッチＳＷ２、ドライバ回路３２４を備える。降圧コンバータ３２２は図８と同様に、出力回路３２６と、コンバータコントローラ３２８を含んでもよい。降圧コンバータ３２２は、所定の目標量に安定化された出力電流ＩＯＵＴを生成する。 FIG. 9 is a circuit diagram showing another configuration example (320B) of the LED driver 320. The LED driver 320B includes a buck converter 322, a bypass switch SW2, and a driver circuit 324. The buck converter 322 may include an output circuit 326 and a converter controller 328, as in FIG. The buck converter 322 produces a regulated output current I OUT to a predetermined target amount.
　バイパススイッチＳＷ２は、半導体光源２１２と並列に接続される。ドライバ回路３２４は、パルス調光信号ＰＷＭ＿ＤＩＭに応じて、バイパススイッチＳＷ２を駆動する。バイパススイッチＳＷ２のオフ期間、半導体光源２１２には出力電流ＩＯＵＴが、駆動電流ＩＬＥＤとして供給され、バイパススイッチＳＷ２のオン期間、出力電流ＩＯＵＴは、バイパススイッチＳＷ２に流れるため、駆動電流ＩＬＥＤはゼロとなる。 The bypass switch SW2 is connected in parallel with the semiconductor light source 212. The driver circuit 324 drives the bypass switch SW2 in response to the pulse dimming signal PWM_DIM. During the off period of the bypass switch SW2, the output current I OUT is supplied to the semiconductor light source 212 as the drive current I LED , and during the on period of the bypass switch SW2, the output current I OUT flows to the bypass switch SW2, so that the drive current I LED Is zero.
　図１０は、ＬＥＤドライバ３２０のさらに別の構成例（３２０Ｃ）を示す回路図である。ＬＥＤドライバ３２０Ｃは、定電圧コンバータ３２７と定電流源３２９を含む。定電圧コンバータ３２７は、所定の電圧レベルに安定化された出力電圧ＶＯＵＴを生成する。定電流源３２９は、半導体光源２１２と直列に接続される。定電流源３２９は、オン、オフが切りかえ可能であり、オン期間において、所定量に安定化された駆動電流ＩＬＥＤを発生する（シンク）。定電流源３２９のオン、オフは、パルス調光信号ＰＷＭ＿ＤＩＭに応じて制御される。 FIG. 10 is a circuit diagram showing still another configuration example (320C) of the LED driver 320. The LED driver 320C includes a constant voltage converter 327 and a constant current source 329. The constant voltage converter 327 produces an output voltage V OUT stabilized at a predetermined voltage level. The constant current source 329 is connected in series with the semiconductor light source 212. The constant current source 329 can be switched on and off, and during the on period, a predetermined amount of stabilized drive current I LED is generated (sink). The on / off of the constant current source 329 is controlled according to the pulse dimming signal PWM_DIM.
　なお、ＬＥＤドライバ３２０の構成はここで例示したものに限定されない。 The configuration of the LED driver 320 is not limited to the one illustrated here.
（実施形態２）
　図１１は、実施形態２に係る車両用灯具１００Ｂを示す図である。実施形態１との相違点を説明する。 (Embodiment 2)
FIG. 11 is a diagram showing a vehicle lamp 100B according to the second embodiment. Differences from the first embodiment will be described.
　走査型光源２００Ｂの光源ユニット２１０Ｂは、複数Ｎ個（Ｎ≧２）の半導体光源２１２＿１～２１２＿Ｎを備える。半導体光源２１２＿１～２１２＿Ｎの光軸は、それぞれの出射ビームＢＭ１～ＢＭＮが、Ｍ枚のブレードミラーのうちの１枚に照射されるように向けられている。ここでは、半導体光源２１２＿２の出射ビームＢＭ２の光線のみを代表として示す。 The light source unit 210B of the scanning light source 200B includes a plurality of N (N ≧ 2) semiconductor light sources 212_1 to 212_N. The optical axes of the semiconductor light sources 212_1 to 212_N are directed so that the respective emitted beams BM 1 to BM N illuminate one of the M blade mirrors. Here, only the light beam of the emitted beam BM 2 of the semiconductor light source 212_2 is shown as a representative.
　ある時刻においてブレードミラー２２４への入射光ＢＭ２は、ブレードミラー２２４の位置（ロータの回転角）に応じた反射角で反射し、車両前方の仮想鉛直スクリーン９００上に瞬時照射スポットＳＰＴ２を形成する。瞬時照射スポットＳＰＴ２は、水平方向（Ｈ方向）、垂直方向（Ｖ方向）それぞれに所定の幅を有している。ブレードミラー２２４が回転することで反射角が変化し、破線で示すように反射ビームＢＭｒ２の出射方向が変化し、瞬時照射スポットＳＰＴ２の水平方向（Ｈ方向）の位置（走査位置）が移動する。この動作を高速に、たとえば５０Ｈｚ以上で繰り返すことで車両前方には、個別配光パターンＰＴＮ２が形成される。 At a certain time, the incident light BM 2 on the blade mirror 224 is reflected at a reflection angle corresponding to the position of the blade mirror 224 (rotation angle of the rotor), and an instantaneous irradiation spot SPT 2 is formed on the virtual vertical screen 900 in front of the vehicle. do. The instantaneous irradiation spot SPT 2 has a predetermined width in each of the horizontal direction (H direction) and the vertical direction (V direction). As the blade mirror 224 rotates, the reflection angle changes, the emission direction of the reflected beam BMr 2 changes as shown by the broken line, and the horizontal (H direction) position (scanning position) of the instantaneous irradiation spot SPT 2 moves. do. By repeating this operation at high speed, for example, at 50 Hz or higher, an individual light distribution pattern PTN 2 is formed in front of the vehicle.
　別のビームＢＭ１，ＢＭ３～ＢＭＮについても同様であり、ｉ番目の反射ビームＢＭｒｉの走査により、個別配光パターンＰＴＮｉが形成される。 The same applies to the other beams BM 1 , BM 3 to BM N , and the individual light distribution pattern PTN i is formed by scanning the i-th reflected beam BM r i .
　たとえばビームＢＭ１～ＢＭＮが形成する個別配光パターンＰＴＮ１～ＰＴＮＮは、仮想鉛直スクリーン９００上の異なる高さに形成される。複数の個別配光パターンＰＴＮ１～ＰＴＮＮの合成により、車両用灯具１００全体の配光パターンＰＴＮ＿ＡＬＬが形成される。垂直方向に隣接する個別配光パターンＰＴＮ同士は、垂直方向にわずかにオーバーラップしていてもよい。 For example, the individual light distribution patterns PTN 1 to PTN N formed by the beams BM 1 to BM N are formed at different heights on the virtual vertical screen 900. By synthesizing a plurality of individual light distribution patterns PTN 1 to PTN N , the light distribution pattern PTN_ALL of the entire vehicle lamp 100 is formed. The individual light distribution patterns PTNs adjacent to each other in the vertical direction may slightly overlap each other in the vertical direction.
　実施形態２において、複数の個別配光パターンＰＴＮ１～ＰＴＮＮの少なくともひとつは、車両用灯具１００Ｂの水平方向の全範囲－θＭＡＸ～＋θＭＡＸに広がっている。すなわち、走査型光源２００Ｂは、複数のビームＢＭｒ１～ＢＭｒＮの少なくともひとつを、水平方向の全範囲にわたり走査する。図１１の例では、すべての個別配光パターンＰＴＮ１～ＰＴＮＮが、水平方向の全範囲－θＭＡＸ～＋θＭＡＸに広がっている。 In the second embodiment, at least one of the plurality of individual light distribution patterns PTN 1 to PTN N extends over the entire horizontal range of the vehicle lamp 100B-θ MAX to + θ MAX . That is, the scanning light source 200B scans at least one of the plurality of beams BMr 1 to BMr N over the entire horizontal range. In the example of FIG. 11, all the individual light distribution patterns PTN 1 to PTN N extend over the entire horizontal range −θ MAX to + θ MAX .
　点灯回路３００Ｂは、走査型光源２００Ｂの走査と同期して、各走査位置における半導体光源２１２＿１～２１２＿Ｎそれぞれの光量、すなわちビームＢＭ１～ＢＭＮの強度を、パルス変調により多階調で調光する。点灯回路３００Ｂは、走査周期、またはそれより長い制御周期で、電流ＩＯＵＴの電流量を変化させてもよい。つまりＰＷＭ調光とＤＣ調光を併用してもよい。 The lighting circuit 300B adjusts the light intensity of each of the semiconductor light sources 212_1 to 212_N at each scanning position, that is, the intensity of the beams BM 1 to BM N in multiple gradations in synchronization with the scanning of the scanning light source 200B. .. The lighting circuit 300B may change the amount of current I OUT in a scanning cycle or a control cycle longer than that. That is, PWM dimming and DC dimming may be used together.
　図１２は、図１１の点灯回路３００Ｂの構成例を示すブロック図である。点灯回路３００Ｂは、複数の半導体光源２１２＿１～２１２＿Ｎに対応する複数のＬＥＤドライバ３２０＿１～３２０＿Ｎを備える。ＰＷＭ信号生成部３１０は、目的とする配光が得られるように、複数のＬＥＤドライバ３２０＿１～３２０＿Ｎに対するパルス調光信号ＰＷＭ＿ＤＩＭ＿１～ＰＷＭ＿ＤＩＭ＿Ｎを生成する。ｉ番目（１≦ｉ≦Ｎ）のＬＥＤドライバ３２０は、対応する半導体光源２１２＿ｉに対して、ＰＷＭ変調された駆動電流ＩＬＥＤｉを供給する。ＬＥＤドライバ３２０の構成は、実施形態１と同様である。マイクロコントローラ３０４および複数のＬＥＤドライバ３２０＿１～３２０＿Ｎは、一枚の基板上に搭載してもよいし、あるいは１つの筐体内に配置してもよい。 FIG. 12 is a block diagram showing a configuration example of the lighting circuit 300B of FIG. The lighting circuit 300B includes a plurality of LED drivers 320_1 to 320_N corresponding to the plurality of semiconductor light sources 212_1 to 212_N. The PWM signal generation unit 310 generates pulse dimming signals PWM_DIM_1 to PWM_DIM_N for a plurality of LED drivers 320_1 to 320_N so that the desired light distribution can be obtained. The i-th (1 ≦ i ≦ N) LED driver 320 supplies a PWM-modulated drive current I LEDi to the corresponding semiconductor light source 212_i. The configuration of the LED driver 320 is the same as that of the first embodiment. The microcontroller 304 and the plurality of LED drivers 320_1 to 320_N may be mounted on one substrate, or may be arranged in one housing.
　この車両用灯具１００Ｂによれば、実施形態１に比べて、高さ方向の分解能を高めることができる。 According to this vehicle lamp 100B, the resolution in the height direction can be improved as compared with the first embodiment.
　実施形態２の変形例を説明する。上の説明では、複数の配光パターンＰＴＮ１～ＰＴＮＮのすべてが、全範囲に広がっていたがその限りでなく、その中のいくつかは、全範囲ではなく、一部の範囲に広がっていてもよい。 A modified example of the second embodiment will be described. In the above explanation, all of the plurality of light distribution patterns PTN 1 to PTN N are spread over the entire range, but not limited to this, and some of them are spread over a part of the range, not the entire range. You may.
　実施形態２では、配光全体を垂直方向に複数の領域に分割し、複数の領域に複数の個別配光パターンＰＴＮ１～ＰＴＮＮを対応付けたがその限りでない。複数の個別配光パターンＰＴＮ１～ＰＴＮＮのいくつかは、完全にオーバーラップしていてもよい。 In the second embodiment, the entire light distribution is vertically divided into a plurality of regions, and a plurality of individual light distribution patterns PTN 1 to PTN N are associated with the plurality of regions, but this is not the case. Some of the plurality of individual light distribution patterns PTN 1 to PTN N may completely overlap.
（パルス変調の周波数について）
　図１３は、実施形態に係る車両用灯具１００Ｉを示す図である。車両用灯具１００Ｉは、カメラ２とともに使用される。カメラ２は、車両用灯具１００Ｉに内蔵されていてもよいし、車両側に設けられてもよい。 (About the frequency of pulse modulation)
FIG. 13 is a diagram showing a vehicle lamp 100I according to the embodiment. The vehicle lamp 100I is used together with the camera 2. The camera 2 may be built in the vehicle lamp 100I or may be provided on the vehicle side.
　車両用灯具１００Ｉの基本構成は、図１のそれと同様であり、走査型光源２００Ａおよび点灯回路３００Ｉを備える。走査型光源２００Ａは半導体光源２１２を含み、半導体光源２１２の出射光にもとづく瞬時照射スポットＳＰＴを配光の水平方向に走査する。点灯回路３００Ｉは、走査型光源２００Ａの走査と同期して、各走査位置における半導体光源２１２の光量をパルス変調により多階調で調光する。 The basic configuration of the vehicle lamp 100I is the same as that shown in FIG. 1, and includes a scanning light source 200A and a lighting circuit 300I. The scanning light source 200A includes the semiconductor light source 212, and scans the instantaneous irradiation spot SPT based on the emitted light of the semiconductor light source 212 in the horizontal direction of the light distribution. The lighting circuit 300I adjusts the amount of light of the semiconductor light source 212 at each scanning position in multiple gradations by pulse modulation in synchronization with the scanning of the scanning light source 200A.
　カメラ２のフレームレートｆＦＲＡＭＥは、２４ｆｐｓ，３０ｆｐｓ，６０ｆｐｓ，１２０ｆｐｓなどが選択される。走査型の車両用灯具をカメラとともに使用する場合、車両用灯具の走査周波数ｆＳＣＡＮが、カメラのフレームレートｆＦＲＡＭＥより高くないと、カメラが撮影した画像に縞が移りこむ可能性がある。そのため、走査周波数ｆＳＣＡＮは、フレームレートｆＦＲＡＭＥより高く定められ、言い換えると走査周期ＴＳＣＡＮ（１／ｆＳＣＡＮ）は、撮像周期１／ｆＦＲＡＭＥより短く定められる。たとえば、走査周波数ｆＳＣＡＮは２００Ｈｚであり、走査周期ＴＳＣＡＮは１／ｆＳＣＡＮ＝５ｍｓとなる。 As the frame rate f FRAME of the camera 2, 24 fps, 30 fps, 60 fps, 120 fps and the like are selected. When a scanning vehicle lamp is used together with a camera, if the scanning frequency f SCAN of the vehicle lamp is not higher than the frame rate f FRAME of the camera, stripes may be transferred to the image taken by the camera. Therefore, the scanning frequency f SCAN is set higher than the frame rate f FRAME , in other words, the scanning cycle T SCAN (1 / f SCAN ) is set shorter than the imaging cycle 1 / f FRAME . For example, the scanning frequency f SCAN is 200 Hz, and the scanning period T SCAN is 1 / f SCAN = 5 ms.
　瞬時照射スポットＳＰＴは、有限の幅θＳＰＯＴを有する。たとえば、この幅θＳＰＯＴは、広がり角であり、数度、具体的には１°～２°程度である。また、瞬時照射スポットＳＰＴの走査範囲θＳＣＡＮ（＝２×θＭＡＸ）は、たとえば１０°～２０°である。 The instantaneous irradiation spot SPT has a finite width θ SPOT . For example, this width θ SPOT is a spread angle, and is several degrees, specifically, about 1 ° to 2 °. Further, the scanning range θ SCAN (= 2 × θ MAX ) of the instantaneous irradiation spot SPT is, for example, 10 ° to 20 °.
　瞬時照射スポットＳＰＴが、それ自身の角度幅θＳＰＯＴだけ移動するのに要する通過時間τは、
　τ＝（θＳＰＯＴ／θＳＣＡＮ）×ＴＳＣＡＮとなる。 The transit time τ required for the instantaneous irradiation spot SPT to move by its own angle width θ SPOT is
τ = (θ SPOT / θ SCAN ) × T SCAN .
　瞬時照射スポットＳＰＴは、１走査周期ＴＳＣＡＮの間に、θＳＣＡＮ移動するから、その移動速度ｖθは、ｖθ＝θＳＣＡＮ／ＴＳＣＡＮとなる。 Since the instantaneous irradiation spot SPT moves by θ SCAN during one scanning cycle T SCAN , the moving speed v θ is v θ = θ SCAN / T SCAN .
　本発明者らは、パルス変調の周期ＴＰＷＭが、通過時間τより長い場合、あるいはそれと同程度の場合に、光が十分に照射されない部分あるいは全く照射されない部分が発生し、スクリーン上に明暗が発生し、カメラの画像に縞として写り込むことを認識した。 In the present invention, when the pulse modulation cycle T PWM is longer than or about the same as the transit time τ, a part where the light is not sufficiently irradiated or a part where the light is not irradiated at all occurs, and the light and darkness is displayed on the screen. It was recognized that it occurred and appeared as stripes in the image of the camera.
　この問題を解決するために、一実施形態において、瞬時照射スポットの水平幅をθＳＰＯＴ、全スキャン角をθＳＣＡＮ、走査周期をＴＳＣＡＮとするとき、パルス変調の周期ＴＰＷＭは、
　ＴＰＷＭ＜Ａ×（θＳＰＯＴ／θＳＣＡＮ）×ＴＳＣＡＮ
を満たしてもよい。これにより、縞の写り込みを抑制できる。Ａは、Ａ≦１であり、瞬時照射スポットの強度分布に応じた定数である。 In order to solve this problem, in one embodiment, when the horizontal width of the instantaneous irradiation spot is θ SPOT , the total scan angle is θ SCAN , and the scan cycle is T SCAN , the pulse modulation cycle T PWM is set.
T PWM <A x (θ SPOT / θ SCAN ) x T SCAN
May be satisfied. This makes it possible to suppress the reflection of stripes. A is A ≦ 1 and is a constant corresponding to the intensity distribution of the instantaneous irradiation spot.
　瞬時照射スポットの速度ｖθは、ｖθ＝θＳＣＡＮ／ＴＳＣＡＮであるから、通過時間τは、θＳＰＯＴ／ｖθと書き換えられる。したがって一実施形態において、瞬時照射スポットの水平幅をθＳＰＯＴ、スキャン速度をｖθとするとき、パルス変調の周期ＴＰＷＭは、
　ＴＰＷＭ＜Ａ×θＳＰＯＴ／ｖθ
を満たしてもよい。 Since the velocity v θ of the instantaneous irradiation spot is v θ = θ SCAN / T SCAN , the transit time τ is rewritten as θ SPOT / v θ . Therefore, in one embodiment, when the horizontal width of the instantaneous irradiation spot is θ SPOT and the scan speed is v θ , the pulse modulation cycle T PWM is set.
T PWM <A × θ SPOT / v θ
May be satisfied.
　定数Ａについて説明する。瞬時照射スポットＳＰＴの水平走査方向（θ方向）の強度分布をΨ（θ）とする。この瞬時照射スポットＳＰＴを、水平方向に速度ｖθで走査したときの、時刻ｔにおけるスクリーン上の瞬時照射スポットＳＰＯＴの強度分布は、
　Ψ（θ－ｖθ・ｔ）
となる。 The constant A will be described. Let Ψ (θ) be the intensity distribution in the horizontal scanning direction (θ direction) of the instantaneous irradiation spot SPT. When this instantaneous irradiation spot SPT is scanned in the horizontal direction at a velocity v θ , the intensity distribution of the instantaneous irradiation spot SPOT on the screen at time t is
Ψ (θ-v θ · t)
Will be.
　走査とパルス変調を組み合わせた場合、時刻ｔにおけるスクリーン上の強度分布は、
　Ψ（θ－ｖθ・ｔ）・ｆＰＷＭ（ｔ，θ）
となる。ｆＰＷＭ（ｔ，θ）は、パルス幅変調の波形を示す関数である。理解の容易化のために、均一な配光を形成する場合、パルス幅変調の関数は、時間ｔのみの関数ｆＰＷＭ（ｔ）として表すことができる。パルス幅変調の周期をＴＰＷＭ、デューティサイクルをｄとすると、ｆＰＷＭ（ｔ）は、（ｔ％ＴＰＷＭ）＜ｄのとき、１、（ｔ％ＴＰＷＭ）＞ｄのとき０である。Ａ％Ｂは、ＡをＢで割った余りを示す剰余演算子（modulo演算子）である。 When scanning and pulse modulation are combined, the intensity distribution on the screen at time t is
Ψ (θ-v θ・ t) ・ f PWM (t, θ)
Will be. f PWM (t, θ) is a function indicating the waveform of pulse width modulation. For ease of understanding, when forming a uniform light distribution, the function of pulse width modulation can be expressed as a function f PWM (t) of time t only. Assuming that the pulse width modulation cycle is T PWM and the duty cycle is d, f PWM (t) is 1 when (t% T PWM ) <d and 0 when (t% T PWM )> d. A% B is a remainder operator (modulo operator) indicating the remainder obtained by dividing A by B.
　スクリーン上に形成される配光の強度分布は、瞬時照射スポットの積分であり、以下の式で表される。
　Ｉ（θ）＝∫０：ＴＰＷＭｆＰＷＭ（ｔ）・Ψ（θ－ｖθ・ｔ）ｄｔ
　∫０：ＴＰＷＭｇ（ｔ）ｄｔは、関数ｇ（ｔ）の範囲０～ＴＰＷＭにおける積分を表す。 The intensity distribution of the light distribution formed on the screen is an integral of the instantaneous irradiation spots and is expressed by the following equation.
I (θ) = ∫ 0: TPWM f PWM (t) ・ Ψ (θ－v θ・ t) dt
∫ 0: TPWM g (t) dt represents the integral in the range 0 to T PWM of the function g (t).
　図１４は、瞬時照射スポットＳＰＯＴの強度分布の一例を示す図である。ここでは水平方向に対して、矩形関数の強度分布を有するビームを考える。スポット径は２°である。 FIG. 14 is a diagram showing an example of the intensity distribution of the instantaneous irradiation spot SPOT. Here, consider a beam having an intensity distribution of a rectangular function with respect to the horizontal direction. The spot diameter is 2 °.
　図１５は、ＰＷＭ周波数を変化させたときの、配光パターンを示す図である。ここでは、１０°の範囲にわたって瞬時照射スポットを走査している。ビームの走査周期ＴＳＣＡＮは５ｍｓ、ＰＷＭ変調のデューティサイクルは２５％としている。 FIG. 15 is a diagram showing a light distribution pattern when the PWM frequency is changed. Here, the instantaneous irradiation spot is scanned over a range of 10 °. The beam scanning cycle TSCAN is 5 ms and the PWM modulation duty cycle is 25%.
　ＰＷＭ周波数が４ｋＨｚ，２ｋＨｚ，１ｋＨｚではフラットな配光が形成されるが、５００Ｈｚまで遅くすると、リップルすなわち縞が発生し、均一な配光が形成できなくなる。 Flat light distribution is formed when the PWM frequency is 4 kHz, 2 kHz, and 1 kHz, but when it is delayed to 500 Hz, ripples, that is, fringes occur, and uniform light distribution cannot be formed.
　この例では、１ｋＨｚより高いＰＷＭ周波数では、カメラ画像の縞は無視できるか、あるいは問題とならないが、０．５ｋＨｚの場合には、問題となる。つまり、ＰＷＭ周波数は１ｋＨｚ以上とすることが好ましく、ＰＷＭ周期は１ｍｓが上限となる。θＳＰＯＴ＝２°、θＳＣＡＮ＝１０°、ＴＳＣＡＮ＝５ｍｓであるから、
　τ＝（θＳＰＯＴ／θＳＣＡＮ）×ＴＳＣＡＮ＝１ｍｓ
である。したがって、矩形ビームを仮定した場合、係数Ａは１となり、縞が抑制された配光の生成条件は、
　ＴＰＷＭ＜θＳＰＯＴ／ｖθ
となる。 In this example, at a PWM frequency higher than 1 kHz, fringes in the camera image are negligible or not a problem, but at 0.5 kHz, they are a problem. That is, the PWM frequency is preferably 1 kHz or higher, and the PWM cycle is limited to 1 ms. Since θ SPOT = 2 °, θ SCAN = 10 °, and T SCAN = 5 ms,
τ = (θ SPOT / θ SCAN ) × T SCAN = 1 ms
Is. Therefore, assuming a rectangular beam, the coefficient A is 1, and the conditions for generating the light distribution with suppressed fringes are
T PWM <θ SPOT / v θ
Will be.
　図１６は、瞬時照射スポットＳＰＯＴの強度分布の一例を示す図である。ここでは水平方向に対して、ガウス関数の強度分布を有するガウシアンビームを考える。ここでは、標準偏差が０．５°のビームを考える。ビーム径の定義の仕方はさまざまであるが、たとえばピーク強度の１／ｅ２における幅をスポット径とすると、スポット径は２°となる。 FIG. 16 is a diagram showing an example of the intensity distribution of the instantaneous irradiation spot SPOT. Here, consider a Gaussian beam having an intensity distribution of a Gaussian function with respect to the horizontal direction. Here, consider a beam with a standard deviation of 0.5 °. There are various ways to define the beam diameter. For example, if the width at 1 / e2 of the peak intensity is the spot diameter, the spot diameter is 2 °.
　図１７は、ＰＷＭ周波数を変化させたときの、配光パターンを示す図である。ここでは、１０°の範囲にわたって瞬時照射スポットを走査している。ビームの走査周期ＴＳＣＡＮは５ｍｓ、ＰＷＭ変調のデューティサイクルは２５％としている。 FIG. 17 is a diagram showing a light distribution pattern when the PWM frequency is changed. Here, the instantaneous irradiation spot is scanned over a range of 10 °. The beam scanning cycle TSCAN is 5 ms and the PWM modulation duty cycle is 25%.
　ＰＷＭ周波数が４ｋＨｚでは、フラットな配光が形成されるが、２ｋＨｚ，１ｋＨｚと遅くするにしたがい、縞が発生し、均一な配光が形成できなくなる。 When the PWM frequency is 4 kHz, a flat light distribution is formed, but as the speed is reduced to 2 kHz and 1 kHz, fringes occur and uniform light distribution cannot be formed.
　この例では、４ｋＨｚ，２ｋＨｚでは、カメラ画像の縞は無視できるか、あるいは問題とならないが、１ｋＨｚの場合には、問題となる。つまり、ＰＷＭ周波数は２ｋＨｚ以上とすることが好ましく、ＰＷＭ周期は０．５ｍｓが上限となる。θＳＰＯＴ＝２°、θＳＣＡＮ＝１０°、ＴＳＣＡＮ＝５ｍｓであるから、
　τ＝（θＳＰＯＴ／θＳＣＡＮ）×ＴＳＣＡＮ＝１ｍｓ
となる。したがって、ガウシアン分布を仮定したときの定数Ａは０．５となり、縞が抑制された配光の生成条件は、
　ＴＰＷＭ＜０．５×θＳＰＯＴ／ｖθ
となる。 In this example, at 4 kHz and 2 kHz, the fringes of the camera image can be ignored or do not matter, but at 1 kHz, it becomes a problem. That is, the PWM frequency is preferably 2 kHz or higher, and the PWM cycle is limited to 0.5 ms. Since θ SPOT = 2 °, θ SCAN = 10 °, and T SCAN = 5 ms,
τ = (θ SPOT / θ SCAN ) × T SCAN = 1 ms
Will be. Therefore, the constant A when the Gaussian distribution is assumed is 0.5, and the conditions for generating the light distribution in which the fringes are suppressed are set.
T PWM <0.5 × θ SPOT / v θ
Will be.
　定数Ａは、ビームの強度分布に依存するほか、ＰＷＭ変調のデューティサイクルにも依存し、デューティサイクルが小さいほど、定数Ａは小さくなる。また、許容できるリップルの量が小さいほど、定数Ａは小さく定める必要がある。これらを勘案すると、定数Ａは、０．２より小さければ、瞬時照射スポットのさまざまな強度分布およびデューティサイクルに対応することができる。たとえばＡを０．１に定めると、上述の条件において必要なＰＷＭ周波数は１０ｋＨｚとなる。これは、一般的なＰＷＭ変調の周波数に比べて、非常に高いといえる。 The constant A depends not only on the intensity distribution of the beam but also on the duty cycle of PWM modulation. The smaller the duty cycle, the smaller the constant A. Further, the smaller the allowable amount of ripple, the smaller the constant A needs to be set. Taking these into consideration, if the constant A is less than 0.2, it can correspond to various intensity distributions and duty cycles of the instantaneous irradiation spot. For example, if A is set to 0.1, the PWM frequency required under the above conditions is 10 kHz. It can be said that this is very high compared to the frequency of general PWM modulation.
　実施形態は例示であり、それらの各構成要素や各処理プロセスの組み合わせにさまざまな変形例が存在すること、またそうした変形例も本開示または本発明の範囲に含まれることは当業者に理解されるところである。 It will be appreciated by those skilled in the art that embodiments are exemplary and that there are various variants of each of these components and combinations of processing processes, and that such variants are also included within the scope of the present disclosure or the invention. It is about to be.
　本開示は、自動車などに用いられる車両用灯具に関する。 This disclosure relates to vehicle lamps used in automobiles and the like.
Ｓ１…センサ情報、Ｓ２…車両情報、Ｓ３…配光パターン情報、４…ＡＤＢ用ＥＣＵ、Ｓ４…位置検出信号、ＰＷＭ＿ＤＩＭ…パルス調光信号、８…スイッチ、１００…車両用灯具、２００…走査型光源、２１０…光源ユニット、２１２…半導体光源、２２０…走査光学系、２２２…モータ、２２４…ブレードミラー、２３０…投影光学系、３００…点灯回路、３０２…位置検出器、３１０…ＰＷＭ信号生成部、３２０…ＬＥＤドライバ、４００…配光コントローラ、９００…仮想鉛直スクリーン。 S1 ... Sensor information, S2 ... Vehicle information, S3 ... Light distribution pattern information, 4 ... ADB ECU, S4 ... Position detection signal, PWM_DIM ... Pulse dimming signal, 8 ... Switch, 100 ... Vehicle lighting equipment, 200 ... Scanning type Light source, 210 ... Light source unit, 212 ... Semiconductor light source, 220 ... Scanning optical system, 222 ... Motor, 224 ... Blade mirror, 230 ... Projection optical system, 300 ... Lighting circuit, 302 ... Position detector, 310 ... PWM signal generator , 320 ... LED driver, 400 ... Light distribution controller, 900 ... Virtual vertical screen.

Claims (6)

  1. 　カメラとともに使用される車両用灯具であって、
    　半導体光源を含み、前記半導体光源の出射光にもとづく瞬時照射スポットを配光の水平方向に走査する走査型光源と、
    　前記走査型光源の走査と同期して、各走査位置における前記半導体光源の光量をパルス変調により多階調で調光可能な点灯回路と、
    　を備え、
    　前記瞬時照射スポットの水平幅をθＳＰＯＴ、全スキャン角をθＳＣＡＮ、走査周期をＴＳＣＡＮとするとき、前記パルス変調の周期ＴＰＷＭは、
    　ＴＰＷＭ＜Ａ×（θＳＰＯＴ／θＳＣＡＮ）×ＴＳＣＡＮ
    を満たし、Ａは、Ａ≦１であり、前記瞬時照射スポットの強度分布に応じた定数であることを特徴とする車両用灯具。     A vehicle lamp used with a camera.
    A scanning light source that includes a semiconductor light source and scans an instantaneous irradiation spot based on the emitted light of the semiconductor light source in the horizontal direction of the light distribution.
    A lighting circuit that can adjust the amount of light of the semiconductor light source at each scanning position in multiple gradations by pulse modulation in synchronization with the scanning of the scanning type light source.
    Equipped with
    When the horizontal width of the instantaneous irradiation spot is θ SPOT , the total scan angle is θ SCAN , and the scan cycle is T SCAN , the pulse modulation cycle T PWM is set.
    T PWM <A x (θ SPOT / θ SCAN ) x T SCAN
    A is a vehicle lamp, wherein A ≦ 1 and is a constant corresponding to the intensity distribution of the instantaneous irradiation spot.
  2. 　カメラとともに使用される車両用灯具であって、
    　半導体光源を含み、前記半導体光源の出射光にもとづく瞬時照射スポットを配光の水平方向に走査する走査型光源と、
    　前記走査型光源の走査と同期して、各走査位置における前記半導体光源の光量をパルス変調により多階調で調光可能な点灯回路と、
    　を備え、
    　前記瞬時照射スポットの水平幅をθＳＰＯＴ、スキャン速度をｖθとするとき、前記パルス変調の周期ＴＰＷＭは、
    　ＴＰＷＭ＜Ａ×θＳＰＯＴ／ｖθ
    を満たし、Ａは、Ａ≦１であり、前記瞬時照射スポットの強度分布に応じた定数であることを特徴とする車両用灯具。     A vehicle lamp used with a camera.
    A scanning light source that includes a semiconductor light source and scans an instantaneous irradiation spot based on the emitted light of the semiconductor light source in the horizontal direction of the light distribution.
    A lighting circuit that can adjust the amount of light of the semiconductor light source at each scanning position in multiple gradations by pulse modulation in synchronization with the scanning of the scanning type light source.
    Equipped with
    When the horizontal width of the instantaneous irradiation spot is θ SPOT and the scan speed is v θ , the pulse modulation cycle T PWM is
    T PWM <A × θ SPOT / v θ
    A is a vehicle lamp, wherein A ≦ 1 and is a constant corresponding to the intensity distribution of the instantaneous irradiation spot.
  3. 　Ａ≦０．５であることを特徴とする請求項１または２に記載の車両用灯具。 The vehicle lamp according to claim 1 or 2, wherein A ≤ 0.5.
  4. 　前記走査型光源は、前記半導体光源に加えて、前記半導体光源の出射光を受け、所定の周期運動を繰り返すことによりその反射光を車両前方で走査する反射体をさらに含み、
    　前記点灯回路は、前記反射体の運動と同期して、パルス変調の制御波形を生成し、前記制御波形に応じて前記半導体光源に供給する駆動電流をスイッチングすることを特徴とする請求項１から３のいずれかに記載の車両用灯具。     In addition to the semiconductor light source, the scanning light source further includes a reflector that receives the emitted light of the semiconductor light source and scans the reflected light in front of the vehicle by repeating a predetermined periodic motion.
    From claim 1, the lighting circuit generates a control waveform of pulse modulation in synchronization with the motion of the reflector, and switches the drive current supplied to the semiconductor light source according to the control waveform. The vehicle lighting equipment according to any one of 3.
  5. 　前記点灯回路は、
    　前記半導体光源と直列に設けられるシリーズスイッチと、
    　前記シリーズスイッチと前記半導体光源の直列接続回路に接続される定電流ドライバと、
    　を備え、
    　前記点灯回路は、走査位置に応じたデューティサイクルで、前記シリーズスイッチをスイッチングすることを特徴とする請求項１から４のいずれかに記載の車両用灯具。     The lighting circuit is
    A series switch provided in series with the semiconductor light source,
    A constant current driver connected to the series connection circuit of the series switch and the semiconductor light source,
    Equipped with
    The vehicle lamp according to any one of claims 1 to 4, wherein the lighting circuit switches the series switch in a duty cycle according to a scanning position.
  6. 　前記定電流ドライバは、
    　スイッチングコンバータと、
    　前記スイッチングコンバータの出力電流の検出値が、所定の目標値に近づくように、前記スイッチングコンバータを駆動するコンバータコントローラと、
    　を含むことを特徴とする請求項５に記載の車両用灯具。     The constant current driver
    With a switching converter
    A converter controller that drives the switching converter so that the detected value of the output current of the switching converter approaches a predetermined target value.
    The vehicle lamp according to claim 5, wherein the lamp comprises the above.
PCT/JP2021/046327 2020-12-18 2021-12-15 Vehicle lamp WO2022131302A1 (en)

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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2017213952A (en) * 2016-05-30 2017-12-07 シャープ株式会社 Lighting device
JP2019059265A (en) * 2017-09-25 2019-04-18 スタンレー電気株式会社 Headlight control unit for vehicle
JP2020119778A (en) * 2019-01-24 2020-08-06 株式会社小糸製作所 Vehicle lighting

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2017213952A (en) * 2016-05-30 2017-12-07 シャープ株式会社 Lighting device
JP2019059265A (en) * 2017-09-25 2019-04-18 スタンレー電気株式会社 Headlight control unit for vehicle
JP2020119778A (en) * 2019-01-24 2020-08-06 株式会社小糸製作所 Vehicle lighting

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