JP2015038885A - Vehicle headlamp - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a compact vehicle headlamp wich forms a variety of light distribution patterns.SOLUTION: A vehicle headlamp 1 comprises a fixed light distribution unit 2, a variable light distribution unit 3 and a control part 7. The variable light distribution unit 3 has a laser device 32, an MEMS mirror 33, and a fluorescent body panel 34 to which a fluorescent body 342 which receives light from the laser device 32 and emits visible light is held. The MEMS mirror 33 is constituted so as to be capable of scanning light from the laser device 32 on the fluorescent body panel 34 accompanied by a tilt of the mirror. The control part 7 scans reflected light on the fluorescent body panel 34 at a prescribed scan pattern by controlling a tilt angle and a tilt direction of the MEMS mirror 33. Furthermore, the control part 7 has a calculation processing part 71 which outputs light distribution pattern information related to a prescribed light distribution pattern, and a drive control part 72 which controls the tilt of the MEMS mirror 33 on the basis of the light distribution pattern information which is outputted from the calculation processing part 71.

Description

  The present invention relates to a vehicle headlamp.

  In recent years, various configurations of variable light distribution type vehicle headlamps capable of changing the light distribution pattern have been proposed.

For example, in the vehicle headlamp described in Patent Document 1, a plurality of light distribution patterns corresponding to the edge shape of each light shielding plate is obtained by switching and using a plurality of light shielding plates having pattern forming edges of different shapes. It can be formed.
However, in this vehicle headlamp, the number of light distribution patterns that can be changed is inevitably limited because it is necessary to provide as many light shielding plates as the number of desired light distribution patterns.

In contrast, in the vehicle headlamp described in Patent Document 2, a large number of light emitting units arranged in a matrix are selectively turned on, and the light is projected by projecting the light forward of the vehicle with a projection lens. Various light distribution patterns can be formed according to the arrangement shape of the light emitting parts.
The vehicle headlamp described in Patent Document 3 includes a plurality of tiltable mirror elements that reflect light from a light source, and a projection lens that projects the reflected light forward of the vehicle. By individually digitally controlling the tilt angle of the mirror element, it is possible to form various light distribution patterns according to the duty ratio of incidence / non-incidence of each reflected light to the projection lens.

JP 2009-211193 A JP 2008-10228 A Japanese Patent No. 3982412

However, in the vehicle headlamp described in Patent Document 2, the light source portion tends to be large because it is necessary to arrange a large number of light emitting portions, and the projection lens for projecting the emitted light is further increased. Difficult to compose.
Moreover, in the vehicle headlamp described in Patent Document 3, the brightness distribution of each reflected light from a plurality of mirror elements cannot be controlled, so that the light distribution pattern that can be formed does not necessarily satisfy the standard requirements for the luminous intensity distribution and the like. There are concerns. That is, there is a limit to the variety of light distribution patterns.

  SUMMARY An advantage of some aspects of the invention is that it provides a compact vehicular headlamp capable of forming various light distribution patterns.

In order to solve the above-mentioned problem, the invention described in claim 1
A vehicle headlamp capable of changing a light distribution pattern formed in front of the vehicle,
A fixed light distribution unit that forms a common part in a plurality of light distribution patterns that can be formed by the vehicle headlamp;
A variable light distribution unit that forms a portion that changes in a plurality of light distribution patterns that the vehicle headlamp can form; and
A control unit;
With
The variable light distribution unit includes a light source, a two-dimensionally tiltable mirror member, and a phosphor panel on which a phosphor that emits visible light in response to light from the light source is supported in a planar shape as a whole. Have
The mirror member is provided at a position where the light emitted from the light source can be reflected toward the phosphor panel, and the reflection direction of the light from the light source is changed along with the tilting of the light to the light. It is configured to be scanable on the surface of the phosphor panel,
The control unit controls the tilt angle and tilt direction of the mirror member to scan the light emitted from the light source and reflected by the mirror member on the surface of the phosphor panel with a predetermined scanning pattern. ,
The phosphor panel emits visible light corresponding to the scanning pattern as the reflected light from the mirror member is scanned on the surface,
The controller is
An arithmetic processing unit that outputs light distribution pattern information relating to a predetermined light distribution pattern;
A drive control unit that controls the tilt of the mirror member based on the light distribution pattern information output from the arithmetic processing unit,
The light distribution pattern information output from the arithmetic output unit is changed to change the light distribution pattern formed in the front of the vehicle by the variable light distribution unit.

The invention according to claim 2 is the vehicle headlamp according to claim 1,
The light source is a laser device or a light emitting diode.

The invention according to claim 3 is the vehicle headlamp according to claim 1 or 2,
The mirror member is a MEMS mirror or a polygon mirror.

Invention of Claim 4 is the vehicle headlamp as described in any one of Claims 1-3,
The arithmetic processing unit senses the vehicle position information by communicating with a front sensor that senses the front of the vehicle and obtains peripheral information, a storage unit that stores position information and map information of traffic signals and road signs, and communication with the outside of the vehicle. The light distribution pattern information is output based on any of information obtained from a communication unit that obtains environmental information.

Invention of Claim 5 is the vehicle headlamp as described in any one of Claims 1-4,
The fixed light distribution unit forms a road surface irradiation portion below a horizontal line among each of the plurality of light distribution patterns.

  According to the present invention, the tilt of the mirror member is controlled, and the light emitted from the light source and reflected by the mirror member is scanned on the phosphor panel, thereby being distributed in a shape and intensity corresponding to this scanning pattern. Visible light is emitted from the phosphor panel. That is, a light distribution pattern corresponding to the scanning pattern on the phosphor panel is formed. Accordingly, it is possible to freely change the light distribution pattern by changing the tilt of the mirror member without having to provide a large number of light emitting portions (light sources) as in the prior art. Therefore, it can be configured more compactly than in the past, and various light distribution patterns can be formed.

It is a figure which shows schematic structure of the vehicle headlamp. It is (a) front view and (b) sectional drawing of a fluorescent substance panel. It is a block diagram which shows the control structure of the vehicle headlamp. It is a figure which shows schematic structure of the modification of a variable light distribution unit. It is a figure which shows schematic structure of the modification of a vehicle headlamp. It is (a) front view of the modification of a fluorescent substance panel, (b) It is sectional drawing. It is (a) front view of the other modification of a fluorescent substance panel, (b) It is sectional drawing.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

<Configuration of vehicle headlamp>
FIG. 1 is a diagram illustrating a schematic configuration of a vehicle headlamp 1 according to the present embodiment.
The vehicle headlamp 1 is of a variable light distribution type capable of changing a light distribution pattern formed in front of the vehicle, and is variable with a fixed light distribution unit 2 provided adjacent to each other as shown in FIG. And a light distribution unit 3.

  Among these, the fixed light distribution unit 2 is a common part in a plurality of light distribution patterns that can be formed by the vehicle headlamp 1 (for example, a road surface irradiation part below the horizontal line when switching between a low beam and a high beam; Pattern common part). The fixed light distribution unit 2 only needs to be able to irradiate a predetermined range in front of the vehicle, and since it can be configured by a conventionally known vehicle lamp such as a project type or a reflector type, detailed description thereof is omitted.

  On the other hand, the variable light distribution unit 3 is a portion that changes in a plurality of light distribution patterns that can be formed by the vehicle headlamp 1, that is, a portion other than the pattern common portion that is formed by the fixed light distribution unit 2 in each light distribution pattern. A portion (hereinafter referred to as a pattern changing portion) is formed. The variable light distribution unit 3 includes a light source module 30 and a projection lens 40, and is configured such that light emitted from the light source module 30 is projected forward of the vehicle by the projection lens 40.

  The light source module 30 is configured in a state where the inside is sealed by a metal casing 31 formed in a planar view shape. The housing 31 accommodates two laser devices 32 and 32 and two micro electro mechanical systems (MEMS) mirrors 33 and 33, and a phosphor panel 34 as a part of the front surface. Yes.

  Among these, the laser devices 32 and 32 emit laser light having a predetermined wavelength, and are light sources according to the present invention. The laser devices 32 and 32 are provided at the rear part in the housing 31 and are configured to individually emit laser beams toward both side surfaces of the housing 31. In the present embodiment, the laser light emitted from the laser devices 32 and 32 is blue light. In addition, cooling fins 31a are formed on the rear surface of the casing 31 behind the laser devices 32, 32 so that the heat generated by the laser devices 32, 32 is mainly cooled.

  The MEMS mirrors 33 and 33 are mirror members according to the present invention, and reflect the laser light emitted from the laser devices 32 and 32. The MEMS mirrors 33 and 33 are disposed on both side surfaces of the housing 31 so as to be positioned on the optical axis of the laser devices 32 and 32, and are individually paired with the laser devices 32 and 32. Further, the MEMS mirrors 33 and 33 are configured to be tiltable two-dimensionally, and the reflection direction of the laser light emitted from the laser devices 32 and 32 can be freely changed. As such MEMS mirrors 33 and 33, for example, known ones described in Japanese Patent Application Laid-Open No. 2005-128147 and Japanese Patent No. 4092283 can be applied.

2A is a front view of the phosphor panel 34 as viewed from the inside of the casing 31, and FIG. 2B is a cross-sectional view.
As shown in these drawings, the phosphor panel 34 has a configuration in which a phosphor 342 is supported on a glass or silicon frame 341. More specifically, the frame body 341 is formed with a plurality of holes 341a penetrating in the thickness direction in a matrix, and the holes 341a are filled with a phosphor 342. The phosphor 342 is a fluorescent material that is excited by receiving blue light emitted from the laser devices 32 and 32 and emits yellow light having a complementary color relationship with the blue light. Therefore, blue light and yellow light are mixed from the phosphor 342 to obtain white light. Although not particularly limited, the size of the hole 341a filled with the phosphor 342 is 80 μm or less in the vertical direction and 100 μm or less in the horizontal direction. Further, the thickness of the frame body 341 that partitions the two adjacent holes 341a and 341a is 50 μm or less.

Next, the control configuration of the vehicle headlamp 1 will be described.
FIG. 3 is a block diagram showing a control configuration of the vehicle headlamp 1.

  As shown in this figure, the vehicle headlamp 1 includes a front sensor 4, a storage unit 5, a communication unit 6, a control unit 7, in addition to the fixed light distribution unit 2 and the variable light distribution unit 3 described above. It has.

  The front sensor 4 senses the front of the vehicle and obtains peripheral information. Peripheral information here refers to the presence and road surface conditions of pedestrians, bicycles, oncoming vehicles, preceding vehicles, and obstacles. As such a front sensor 4, a known sensor such as a camera, a radar, or an acoustic sensor can be used.

The storage unit 5 stores map information including two-dimensional and three-dimensional geometric information about roads in addition to position information such as traffic signals, external lighting, and road signs.
The communication unit 6 obtains environmental information such as own vehicle position information, time, weather, and the like by communication with the outside of the vehicle.
In addition, the various information which concerns on these memory | storage parts 5 and the communication part 6 is good also as obtaining from the apparatus provided in the vehicle.

The control unit 7 includes an arithmetic processing unit 71 and a drive control unit 72 while being connected to the above-described units.
Among these, the arithmetic processing part 71 receives various information from the front sensor 4, the memory | storage part 5, and the communication part 6, and determines the optimal light distribution pattern which should be formed. Then, light distribution pattern information about the shape of the light distribution pattern and the light intensity distribution is output to the drive control unit 72. At this time, various information from each unit is sequentially updated, and determination of the light distribution pattern and output of the light distribution pattern information are repeatedly performed at predetermined time intervals.
On the other hand, the drive control unit 72 controls the lighting of the fixed light distribution unit 2 and controls the laser devices 32 and 32 and the MEMS mirrors 33 and 33 based on the light distribution pattern information input from the arithmetic processing unit 71. Specifically, the drive control unit 72 controls the lighting intensity and lighting time of the laser light emitted from the laser devices 32 and 32, and controls the tilt angle and tilt direction of the MEMS mirrors 33 and 33.

<Light distribution pattern formation process>
Then, the formation process of the light distribution pattern in the vehicle headlamp 1 is demonstrated.
First, as described above, when the arithmetic processing unit 71 determines an optimum light distribution pattern based on various information, the drive control unit 72 uses the laser devices 32 and 32 based on the light distribution pattern information about the light distribution pattern. And the MEMS mirrors 33 and 33 are controlled. Further, the drive control unit 72 turns on the fixed light distribution unit 2 when it is not lit, and forms a pattern common portion of the light distribution pattern.

And the drive control part 72 controls the laser apparatuses 32 and 32 and the MEMS mirrors 33 and 33, and the pattern change which should form the light radiate | emitted from the laser apparatuses 32 and 32 and reflected by the MEMS mirrors 33 and 33 is formed. The phosphor panel 34 is scanned with a predetermined scanning pattern corresponding to the portion. Here, the “scanning pattern” is a scanning locus including a change in luminous intensity.
Note that the two sets of laser device 32 and MEMS mirror 33 may both be scanned with light in the same scanning pattern, or may be responsible for scanning different portions. Also, the scanning mode at this time may be so-called vector scanning in which light is scanned so as to trace the shape of the pattern change portion, or the entire surface of the phosphor panel 34 including the portion outside the pattern change portion. A so-called raster scan in which light is scanned may be used. Alternatively, a combination of both may be used. However, the vector scan is more efficient when it is desired to irradiate only a specific portion within the pattern change portion.

  When light is scanned on the phosphor panel 34, the portion of the phosphor 342 where the light has been scanned is excited by this light (blue light) to emit yellow light, and the blue light and yellow light are mixed to produce white light. Light is emitted. In this way, visible light distributed in a shape and luminous intensity corresponding to the scanning pattern is emitted from the phosphor panel 34 and projected to the front of the vehicle by the projection lens 40, thereby forming a pattern change portion corresponding to the scanning pattern. And this pattern change part and the pattern common part formed of the fixed light distribution unit 2 are formed simultaneously, and a desired light distribution pattern is formed as a whole.

<Action and effect>
According to the above vehicle headlamp 1, the lighting intensity of the laser devices 32, 32 and the tilt of the MEMS mirrors 33, 33 are controlled, and the light is emitted from the laser devices 32, 32 and reflected by the MEMS mirrors 33, 33. By scanning the phosphor light on the phosphor panel 34 with a predetermined scanning pattern, visible light distributed in a shape and intensity corresponding to the scanning pattern is emitted from the phosphor panel 34 and projected to the front of the vehicle by the projection lens 40. Is done. That is, a pattern change portion (light distribution pattern) corresponding to the scanning pattern on the phosphor panel 34 is formed. This makes it possible to freely change the light distribution pattern by merely changing the lighting intensity of the laser devices 32 and 32 and the tilt of the MEMS mirrors 33 and 33 without having to provide a large number of light emitting units (light sources) as in the prior art. it can. Therefore, it can be configured more compactly than before, and various light distribution patterns can be formed according to various traveling conditions such as the presence or absence of pedestrians and oncoming vehicles, weather, road surface conditions, and the like.

  In addition, since two sets of laser devices 32 and MEMS mirrors 33 are provided, the degree of freedom of the light distribution pattern that can be formed is increased, and even if one of the sets has an abnormality, the remaining one set has a pattern change portion. Thus, safe vehicle travel can be maintained.

  In addition, since a light distribution pattern can be formed by irradiating light only to the necessary illumination area, the laser can be compared with the light that is partially blocked by the light shielding plate according to the light distribution pattern while irradiating the entire illumination area The power consumption of the devices 32 and 32 (light source) can be suppressed.

Further, since there are no movable parts other than the MEMS mirrors 33, 33, for example, the durability is superior to that of a variable light distribution type in which the light shielding plate is switched and used.
In addition, since the light source module 30 is sealed, the laser light from the laser devices 32 and 32 is not leaked to the outside and is safe.

<Modification>
It should be noted that the present invention should not be construed as being limited to the above-described embodiment, and of course can be modified or improved as appropriate.

  For example, in the above embodiment, the laser devices 32 and 32 are used as the light source, but as shown in FIG. 4, light emitting diodes 32A and 32A may be used as the light source. However, since the light emitting diode 32A has a Lambertian irradiation characteristic unlike the laser device 32, when the light emitting diode 32A is used, the collimator that converges the light emitted from the light emitting diode 32A in the direction toward the MEMS mirror 33. It is better to provide the lens 35.

  In the above embodiment, the fixed light distribution unit 2 is provided separately from the variable light distribution unit 3, but instead of such a fixed light distribution unit 2, as shown in FIG. A fixed light distribution unit 2A configured integrally with the unit 3 may be provided. The fixed light distribution unit 2A is provided on the front surface of the casing 31 on the side of the phosphor panel 34, and shares the projection lens 40 of the variable light distribution unit 3. In this case, it is preferable to provide cooling fins 31b for the fixed light distribution unit 2A in the casing 31.

  Alternatively, all the light distribution patterns including the pattern common portion may be formed only by the variable light distribution unit 3 without providing the fixed light distribution unit 2. However, in this case, if an abnormality occurs in any one of the two sets of laser devices 32 and MEMS mirrors 33, the pattern common portion is formed by the remaining one set, which may hinder vehicle travel for the time being. It is preferable from the viewpoint of safety.

In addition, as shown in FIG. 6, the phosphor panel 34 may not have the holes 341a penetrating forward of the frame body 341. As shown in FIG. 7, the phosphor panel 34 of FIG. In FIG. 5, the partition between the adjacent hole portions 341a may be removed, and a concave portion 341b that opens greatly may be formed inside the light source module 30.
Further, depending on the optical design intention, a microlens array (none of which is shown) in which a plurality of microlenses are arranged corresponding to each hole 341a may be provided on the emission surface side of the phosphor panel 34. Here, as shown in FIGS. 6 and 7, when the hole 341 a or the recess 341 b is not penetrated to the front of the frame body 341, this microlens array may be configured integrally with the frame body 341. .

  In addition, the laser devices 32 and 32 emit blue light, and the phosphor panel 34 includes the phosphor 342 that emits yellow light by the blue light. That's fine. For example, the laser devices 32 and 32 may emit ultraviolet light, and the phosphor panel 34 may include three types of phosphors that emit red (R), green (G), and blue (B) light. In this case, for example, three holes 341a filled with three kinds of phosphors may be sequentially arranged by a triplet arrangement or a quad arrangement. In this way, by mixing each color light of RGB excited by ultraviolet light, it is possible to emit light of various colors other than white light, and further improve the diversity of the light distribution pattern. Can do.

Further, the laser device 32 and the MEMS mirror 33 are not limited to two sets, and for example, a total of four sets may be provided on each of the upper, lower, left, and right surfaces of the casing 31, and the casing 31 has a polygonal cross section. Thus, the number of combinations of the laser device 32 and the MEMS mirror 33 can be set to a plurality of sets that match the polygonal shape of the cross section of the housing 31.
Although the MEMS mirror 33 is used as the mirror member, a polygon mirror, for example, may be used as long as the laser light from the laser device 32 can be scanned on the phosphor panel 34.
Moreover, it is good also as the communication part 6 acquiring map information by communication with the vehicle exterior, without providing the memory | storage part 5 which memorize | stores map information.

DESCRIPTION OF SYMBOLS 1 Vehicle headlamp 2 Fixed light distribution unit 3 Variable light distribution unit 7 Control part 30 Light source module 32 Laser apparatus (light source)
32A Light emitting diode (light source)
33 MEMS mirror (mirror member)
34 phosphor panel 35 collimator lens (optical element)
40 Projection lens 71 Operation processing unit 72 Drive control unit 342 Phosphor

Claims (5)

A vehicle headlamp capable of changing a light distribution pattern formed in front of the vehicle,
A fixed light distribution unit that forms a common part in a plurality of light distribution patterns that can be formed by the vehicle headlamp;
A variable light distribution unit that forms a portion that changes in a plurality of light distribution patterns that the vehicle headlamp can form; and
A control unit;
With
The variable light distribution unit includes a light source, a two-dimensionally tiltable mirror member, and a phosphor panel on which a phosphor that emits visible light in response to light from the light source is supported in a planar shape as a whole. Have
The mirror member is provided at a position where the light emitted from the light source can be reflected toward the phosphor panel, and the reflection direction of the light from the light source is changed along with the tilting of the light to the light. It is configured to be scanable on the surface of the phosphor panel,
The control unit controls the tilt angle and tilt direction of the mirror member to scan the light emitted from the light source and reflected by the mirror member on the surface of the phosphor panel with a predetermined scanning pattern. ,
The phosphor panel emits visible light corresponding to the scanning pattern as the reflected light from the mirror member is scanned on the surface,
The controller is
An arithmetic processing unit that outputs light distribution pattern information relating to a predetermined light distribution pattern;
A drive control unit that controls the tilt of the mirror member based on the light distribution pattern information output from the arithmetic processing unit,
The vehicle headlamp is configured such that a light distribution pattern formed in front of the vehicle by the variable light distribution unit is changed by changing light distribution pattern information output from the arithmetic output unit. light.   The vehicle headlamp according to claim 1, wherein the light source is a laser device or a light emitting diode.   The vehicle headlamp according to claim 1, wherein the mirror member is a MEMS mirror or a polygon mirror.   The arithmetic processing unit senses the vehicle position information by communicating with a front sensor that senses the front of the vehicle and obtains peripheral information, a storage unit that stores position information and map information of traffic signals and road signs, and communication with the outside of the vehicle. The vehicular front according to any one of claims 1 to 3, wherein the light distribution pattern information is output based on any one of information obtained from a communication unit that obtains environmental information. Lighting.   The vehicle headlamp according to any one of claims 1 to 4, wherein the fixed light distribution unit forms a road surface irradiation portion below a horizontal line among each of the plurality of light distribution patterns. light.

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