JP7426838B2 - Lighting equipment, vehicle lights - Google Patents

Description

The present invention relates to a lighting device that generates a light distribution pattern using a light deflector, and a vehicle lamp using the lighting device.

Conventionally, as a vehicle lamp installed in a vehicle, a laser beam emitted from a light source is scanned by a MEMS (Micro Electro Mechanical Systems) optical deflector so that the scanned light is incident on a phosphor to create a light distribution pattern. There was something projected in front of the vehicle. Currently, AFS (Adaptive Front-Lighting System), which controls the light distribution of headlights according to the direction of travel of the vehicle, has been realized using such vehicle lamps.

For example, the vehicle lamp described in Patent Document 1 scans the light emitted from the light source with a light deflection mirror of a light deflector, corrects the distortion of the scanned light with a correction mirror, and creates a two-dimensional image of the phosphor. drawing a statue.

Further, the control device transmits a control signal to the optical deflector and the excitation light source, and rotates the optical deflection mirror based on the control signal. Then, the control signal controls the on/off and brightness of the laser light from each excitation light source (Patent Document 1/Paragraph 0039).

Japanese Patent Application Publication No. 2018-198139

However, in the vehicle lamp of Patent Document 1, in order to obtain a light distribution pattern, the on/off and brightness of the light source are changed during scanning with laser light, so there is a problem that the lighting efficiency of the light source decreases. . In addition, since the method always scans the entire area, it is disadvantageous in achieving high illuminance.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a lighting device that can efficiently utilize light from a light source.

The present invention is an illumination device that generates a predetermined light distribution pattern, and includes a light source that emits light and a rotating mirror, and the light emitted from the light source is controlled in a predetermined angular range by the rotating mirror. a light deflector that reflects and scans; a wavelength converter that has a light distribution forming area for generating the light distribution pattern and converts the wavelength of the light scanned by the light deflector; and the wavelength converter an optical member that controls light from the optical device to project the light distribution pattern; and a reflector mirror disposed so that the light from the optical deflector is incident on the wavelength conversion section, the reflector mirror has a plurality of curved surface regions having different curved surface shapes, the plurality of curved surface regions are arranged with mutually different inclinations, and the light beam is scanned by the optical deflector and reflected by each of the plurality of curved surface regions. The light is characterized in that the light distribution forming area of the wavelength conversion section is irradiated with light.

The illumination device of the present invention reflects and scans the light from the light source using the rotating mirror of the optical deflector. The scanned light enters the light distribution forming area of the wavelength conversion unit, and after the wavelength of the light is converted (for example, converted to white light), it is projected by an optical member to generate a predetermined light distribution pattern. .

The light scanned by the optical deflector enters the wavelength conversion section after being reflected by the reflector mirror, and the reflector mirror is provided with a plurality of curved regions having different curved shapes. Therefore, light is focused according to the shape of the curved area without controlling the light amount of the light source during scanning, and a predetermined light distribution pattern can be efficiently obtained. Further, the plurality of curved surface areas have different slopes from each other, and the light reflected from each curved surface area illuminates the light distribution forming area. Thereby, the positions of the projected light distribution patterns can be matched.

In the lighting device of the present invention, it is preferable that at least one of the plurality of curved surface regions has a curved shape such that light reflected by the curved surface region has an intensity distribution on the light distribution forming region.

Since at least one of the plurality of curved surface areas has a mutually different curved surface shape, a portion where the reflected light is focused is generated, forming an intensity distribution on the light distribution forming area. Thereby, it is possible to generate a light distribution pattern in which the light intensity at a desired position is increased.

The illumination device of the present invention further includes a control unit that controls the optical deflector, and the control unit controls the angle range of the rotating mirror so that one of the plurality of curved areas is irradiated with light. It is preferable to control the

According to this configuration, the control unit controls the optical deflector (rotating mirror) so that the scanned light is incident on the reflector mirror. For example, the control unit adjusts the vertical axis direction of the scanned light and controls the angular range so that the light is incident on one curved area of the reflector mirror. Thereby, a light distribution pattern corresponding to the curved surface area can be obtained.

Moreover, in the lighting device of the present invention, it is preferable that a plurality of sets of the light source, the optical deflector, and the reflector mirror are provided.

According to this configuration, a plurality of sets of light sources, light deflectors, and reflector mirrors are provided, and light from each light source is made to enter a common wavelength conversion section (light distribution forming area). This increases the amount of light emitted from the wavelength conversion section, so that the resulting light distribution pattern can be made clearer.

Further, the illumination device of the present invention preferably includes a correction lens that corrects a change in spot size of the light reflected by the rotating mirror due to scanning.

When light is scanned by an optical deflector, there may be a difference in spot size between the center and the ends of the scanning range. Therefore, the light can be corrected by passing through the correction lens, and the light distribution pattern can be made clear.

Moreover, in the lighting device of the present invention, it is preferable that the wavelength conversion section is of a light transmission type.

According to this configuration, the light reflected by the reflector mirror passes through the wavelength conversion section, so it is possible to arrange an optical member on the back side of the wavelength conversion section and project a light distribution pattern on the back side. .

Furthermore, in the lighting device of the present invention, the wavelength conversion section may be of a light reflection type.

According to this configuration, the light reflected by the reflector mirror is reflected by the wavelength converter, so the light reflected by the wavelength converter returns to the reflector mirror side. Therefore, it is possible to arrange the optical member on the reflector mirror side with respect to the wavelength conversion section and project the light distribution pattern further back thereto.

A vehicle lamp according to the present invention is characterized by comprising the lighting device according to any one of the above-mentioned (claims 1 to 7).

By using the lighting device characterized by the reflector mirror in a vehicle lamp, it is possible to efficiently utilize the light from the light source and project a desired light distribution pattern in front of the vehicle.

FIG. 1 is a diagram showing the overall configuration of a lighting device according to the present embodiment. FIG. 3 is a diagram illustrating details of the illumination device (first optical system). FIG. 7 is a diagram (modified form) illustrating details of the illumination device (first optical system). FIG. 3 is a diagram illustrating system control of a lighting device. (a) A diagram explaining a reflector mirror. (b) A diagram illustrating a brightness cross section of reflected light. (c) A diagram illustrating light distribution pattern 1. (d) A diagram illustrating light distribution pattern 2. (e) A diagram explaining light distribution pattern 3.

FIG. 1 is a diagram showing the overall configuration of a lighting device 1 according to an embodiment of the present invention.

As illustrated, the illumination device 1 includes a first optical system 2A including a light source 4, a light deflector 5, etc., and a second optical system 2B including a projection lens 10. This lighting device 1 is used, for example, as a headlight for a vehicle (vehicle lamp).

First, the first optical system 2A includes light sources 4 and 14, optical deflectors 5 and 15, reflector mirrors 7 and 17, and a phosphor plate 8. The light source 4 corresponds to the optical deflector 5 and the reflector mirror 7, and the light source 14 corresponds to the optical deflector 15 and the reflector mirror 17. Here, an example is shown in which the combination of the light source, the optical deflector, and the reflector mirror is composed of two sets, but there may be three or more sets.

The light sources 4 and 14 are laser diodes (LDs) with a center wavelength of approximately 450 nm, and emit blue light. Note that as the light source, parallel light emitting diodes (LEDs) may be used, or a laser irradiator that irradiates laser light in which RGB colors are mixed may be used.

The optical deflectors 5 and 15 include two-dimensionally tiltable MEMS mirrors 5a and 15a ("rotating mirrors" of the present invention), and reflect the light emitted from the light sources 4 and 14 in a predetermined angular range. and scan. The optical deflectors 5 and 15 are arranged on the optical axis so that the light enters the center of the MEMS mirrors 5a and 15a. As an optical deflector including such MEMS mirrors 5a and 15a, for example, mirrors having a known configuration described in Japanese Patent Laid-Open No. 2005-128147 and Japanese Patent No. 4092283 can be applied.

The reflector mirrors 7 and 17 are arranged on the optical axis so that the light (scanning light) from the optical deflectors 5 and 15 is incident on the phosphor plate 8. Note that details of the reflector mirrors 7 and 17 will be described later.

The phosphor plate 8 (the "wavelength conversion unit" of the present invention) is a flat plate in which a phosphor (Y3Al5O12:Ce3+) is coated with a constant thickness on a sapphire substrate. The phosphor is a fluorescent material that is excited by being irradiated with blue light emitted from the light sources 4 and 14 and emits yellow light, which is a complementary color to the blue light. Therefore, white light, which is a mixture of blue light and yellow light, is emitted from the phosphor plate 8. The phosphor plate 8 of this embodiment includes a scattering material, so that the influence of the incident angle of light is reduced. Note that the broken line portion of the phosphor plate 8 is a light distribution forming region 8a into which light from the reflector mirrors 7 and 17 enters and for generating a light distribution pattern.

Further, the second optical system 2B includes a projection lens 10 and a lens holder 11 that holds the projection lens 10.

The projection lens 10 (the "optical member" of the present invention) consists of four lenses 10a to 10d, and each lens 10a to 10d is held by a lens holder 11. Each of the lenses 10a to 10d has the role of suppressing distortion and the like and improving the resolution of the light distribution pattern. The lens 10a closest to the phosphor plate 8 is arranged so that its rear focal point is at the position of the phosphor plate 8.

The number of projection lenses 10 is not limited to four, and in particular, if the phosphor plate 8 has a curved shape, the light distribution pattern can be projected with a smaller number of lenses. Furthermore, the projection lens 10 suppresses aberrations of the light from the phosphor plate 8, magnifies the image, and inversely projects it forward. Then, a light distribution pattern of a predetermined shape is generated on the virtual vertical screen S (disposed approximately 25 m in front of the lighting device 1).

Next, details of the first optical system 2A of the illumination device 1 will be described with reference to FIG. 2. The light source 4 side (left side in the figure) will be described below, but the light source 14 side has the same configuration and effect.

As shown in the figure, the control board 25 is provided with a light source 4. The light emitted from the light source 4 enters the MEMS mirror 5a of the optical deflector 5, and is scanned at a predetermined angle. Note that a condensing lens may be provided on the front side of the light source 4 to condense the light emitted from the light source 4. The light reflected and scanned by the MEMS mirror 5a then enters the reflector mirror 7.

In this embodiment, a correction lens 6 is disposed between the optical deflector 5 and the reflector mirror 7, although it is not an essential configuration. Since the speed of the MEMS mirror 5a is different between the center and the end of the scanning range, the spot size of the scanned light may change, which may adversely affect the final light distribution pattern. The correction lens 6 has the effect of correcting the difference in spot size of the scanned light and making the light distribution pattern clear.

The reflector mirror 7 has three curved regions (regions R1 to R3 to be described later) having different curved shapes. The scanned light enters any one of the curved surface areas, and the light reflected from the curved surface area illuminates the phosphor plate 8. Then, the light of the two-dimensional image (white image) that is the source of the light distribution pattern according to the curved surface shape is transmitted through the phosphor plate 8 and enters the projection lens 10 (not shown).

Furthermore, the three curved areas of the reflector mirror 7 have different inclinations (different normal angles). Due to this inclination, the light reflected by each curved surface area illuminates the same area (light distribution forming area 8a) of the phosphor plate 8, so that the light distribution pattern projected forward through the projection lens 10 is The centers will match.

FIG. 3 shows a modification (first optical system 20A) in which a reflective phosphor plate 9 is used instead of the transmissive phosphor plate 8.

When using the phosphor plate 8 (see FIG. 2), the projection lens 10 is disposed on the side of the phosphor plate 8 that faces the reflector mirror 7. On the other hand, when using the phosphor plate 9, the projection lens 10 is disposed on the same side of the phosphor plate 9 as the reflector mirror 7. Note that the broken line portion of the phosphor plate 9 is a light distribution forming area 9a into which the light from the reflector mirror 7 enters and is used to generate a light distribution pattern.

The two-dimensional image reflected by the phosphor plate 9 is separated into a control board 25a for the light source 4 and a control board 25b for the light source 14 so that it enters the projection lens 10, and the two-dimensional image passes between them. Do it like this. Note that the light distribution pattern is generated from a two-dimensional image through the projection lens 10, and the center of the light distribution pattern coincides with the light reflected from any curved surface area of the reflector mirror 7.

Next, with reference to FIG. 4, system control of the illumination device 1, particularly control of the optical deflectors 5 and 15, will be described.

On the control board 25, in addition to the above-described light sources 4 and 14 and their control circuits, a mirror control electronic circuit 30 for controlling the MEMS mirrors 5a and 15a of the optical deflectors 5 and 15 is mounted. Further, the mirror control electronic circuit 30 includes a mirror control IC 31 and an initial characteristic data storage element 32.

The mirror control IC 31 generates a control signal (sine wave voltage) for the MEMS mirrors 5a and 15a using software for mirror control, and transmits the control signal to the piezoelectric actuators of the optical deflectors 5 and 15. At that time, the mirror control IC 31 refers to the initial characteristic data of the MEMS mirrors 5a and 15a stored in the initial characteristic data storage element 32. Thereby, the mirror control electronic circuit 30 can control the operation of the MEMS mirrors 5a and 15a.

At this time, the mirror control electronic circuit 30 displaces the MEMS mirrors 5a, 15a in the vertical axis direction and then controls the MEMS mirrors 5a, 15a to rotate (so-called V-axis offset). In this way, by controlling the angular range of the MEMS mirrors 5a, 15a, the curved areas R1 to R3 of the reflector mirrors 7, 17 can be used properly. Finally, light distribution patterns (light distribution patterns 1 to 3 to be described later) corresponding to the curved surface shape of each curved surface area are generated on the virtual vertical screen S (not shown).

Next, with reference to FIG. 5, the reflector mirrors 7 and 17 of the lighting device 1 and the finally obtained light distribution pattern will be described.

First, FIG. 5(a) shows a view of the reflector mirrors 7 and 17 viewed from above. The reflector mirrors 7 and 17 have three curved regions R1 to R3 with different curved shapes (free-form surface, paraboloid, surface having a plurality of concavities and convexities with different curvatures, etc.). As described above, the light scanned by the optical deflectors 5 and 15 enters one of the curved surface regions R1 to R3 under the control (V-axis offset) by the mirror control electronic circuit 30.

For example, when the scanned light enters the curved surface area R1 and is scanned, the reflected light is focused at a predetermined position due to the curved surface shape specific to the curved surface area R1, and the brightness cross section is the upper part of FIG. 5(b). (corresponding to the A1-A1 cross section in FIG. 5(a)). Note that since there is no need to change the output of the light source 4 during scanning, control is simpler than in conventional systems.

Then, the reflected light from the curved surface area R1 illuminates the phosphor plate 8, and finally the light distribution pattern 1 (center coordinate O ₁ ) shown in FIG. 5(c) is projected onto the virtual vertical screen S. Light distribution pattern 1 is a light distribution according to the brightness cross section (upper row of FIG. 5(b)), and the light intensity in the left elliptical portion is strong, and the intensity distribution (equal intensity line) is as shown by the broken line. When the lighting device 1 is used as a vehicle lamp, the light distribution pattern 1 is used when the vehicle runs on a left curve.

Further, when the light from the optical deflectors 5 and 15 enters the curved surface area R2 and is scanned, the reflected light is focused at a predetermined position due to the curved surface shape peculiar to the curved surface area R2, and the brightness cross section is shown in FIG. It becomes as shown in the middle row of b) (corresponding to the A2-A2 cross section in FIG. 5(a)).

When the reflected light from the curved surface area R2 is irradiated onto the phosphor plate 8, the light distribution pattern 2 (center coordinate O2 ₎ shown in FIG. 5(d) is finally projected onto the virtual vertical screen S. In the light distribution pattern 2, the light intensity in the central elliptical portion becomes stronger according to the brightness cross section (the middle part of FIG. 5(b)), and the intensity distribution becomes as shown by the broken line. Note that the light distribution pattern 2 is used, for example, when the vehicle travels straight.

Furthermore, when the light enters the curved surface area R3 and is scanned, the reflected light is focused at a predetermined position due to the curved surface shape unique to the curved surface area R3, and the brightness cross section is the lower part of FIG. (corresponding to the A3-A3 cross section in (a)).

When the reflected light from the curved surface area R3 is irradiated onto the phosphor plate 8, the light distribution pattern 3 shown in FIG. 5(e) is finally projected onto the virtual vertical screen S. In the light distribution pattern 3 (center coordinate O ₃ ), the light intensity in the right elliptical portion becomes higher according to the brightness cross section (lower part of FIG. 5(b)), and the intensity distribution becomes as shown by the broken line. Note that the light distribution pattern 3 is used, for example, when the vehicle travels around a right curve.

In this way, the curved areas R1 to R3 of the reflector mirrors 7 and 17 generate light distribution patterns 1 to 3, respectively. That is, the curved surface regions R1 to R3 have a curved surface shape that produces a unique intensity distribution (gradation of light intensity).

Furthermore, since the curved areas R1 to R3 have different slopes, the light irradiates the same area of the phosphor plate 8 (light distribution forming area 8a). Therefore, the center coordinates O ₁ to O ₃ of the light distribution patterns 1 to 3 that are finally generated also overlap on the virtual vertical screen S.

The lighting device 1 of the above embodiment can be used not only as a vehicle lamp but also as a small projector device or a LiDER device that measures the distance to an object using light.

Furthermore, in the above description, an example has been shown in which the reflector mirror is separated into three curved surface areas, but it is sufficient that the reflector mirror has at least two or more different curved surface areas. For example, if there are five curved areas, five light distribution patterns are obtained. Two curved surface areas may be provided to obtain light distribution patterns for low beam and high beam. Further, each curved surface region may have a different area.

The number of light sources and light deflectors, and the number of light sources that irradiate light to one light deflector can be changed as appropriate, and may be selected depending on the light intensity of the required light distribution pattern. When there are a plurality of optical deflectors, each optical deflector may have a different irradiation area and share the role of generating a light distribution pattern.

In the above embodiment, a so-called excitation light source is used, but a light source that emits the color of the light source itself may also be used. In this case, a phosphor (projector) is not required, and the light from the light source is directly irradiated. Furthermore, a light-transmitting diffuser plate may be used instead of the phosphor. Further, the light source only needs to emit one unified beam of light, and for example, the light may be guided through a fiber. The light guided to the fiber may be white light mixed with RGB.

1... Illumination device, 2A, 20A... First optical system, 2B... Second optical system, 4, 14... Light source, 5, 15... Light deflector, 5a, 15a... MEMS mirror, 6, 16... Correction lens, 7 , 17... Reflector mirror, 8... Fluorescent plate (transmissive type), 8a... Light distribution forming area (transmissive type fluorescent plate), 9... Fluorescent plate (reflective type), 9a... Light distribution forming area (reflective fluorescent type) body plate), 10... Projection lens, 11... Lens holder, 25, 25a, 25b... Control board, 30... Mirror control electronic circuit, 31... Mirror control IC, 32... Initial characteristic data storage element.

Claims (7)

A lighting device that generates a predetermined light distribution pattern,
a light source that emits light;
an optical deflector that has a rotating mirror and scans the light emitted from the light source by reflecting it in a predetermined angular range by the rotating mirror;
a wavelength converter having a light distribution forming area for generating the light distribution pattern and converting the wavelength of the light scanned by the optical deflector;
an optical member that controls light from the wavelength conversion unit to project the light distribution pattern;
a reflector mirror arranged so that the light from the optical deflector is incident on the wavelength conversion section;
A control unit that controls the optical deflector ,
The reflector mirror has a plurality of curved regions having different curved shapes,
The control unit controls an angular range of the rotating mirror so that one of the plurality of curved areas is irradiated with light,
The plurality of curved surface regions are arranged with mutually different slopes, and the light that is scanned by the optical deflector and reflected by each of the plurality of curved surface regions illuminates the light distribution forming region of the wavelength conversion unit. A lighting device characterized by: 2. At least one of the plurality of curved surface regions has a curved shape such that light reflected by the curved surface region forms an intensity distribution on the light distribution forming region. lighting equipment. The lighting device according to claim 1 or 2, comprising a plurality of sets of the light source, the light deflector, and the reflector mirror. The illumination device according to any one of claims 1 to 3 , further comprising a correction lens that corrects a change in spot size of the light reflected by the rotating mirror due to scanning. The lighting device according to any one of claims 1 to 4 , wherein the wavelength conversion section is of a light transmission type. The lighting device according to any one of claims 1 to 4 , wherein the wavelength conversion section is of a light reflection type. A vehicle lamp comprising the lighting device according to any one of claims 1 to 6 .

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