JP2021140936A - Vehicular headlamp - Google Patents

Abstract

To provide a vehicular headlamp that suppresses variation in image height related to a scanning-directional position of a scanning light beam.SOLUTION: A vehicular headlamp 10 comprises a correction lens 19 between a light deflector 18 and a phosphor plate 23. The correction lens 19 has its optical axis aligned with a center optical axis 33 as the optical axis of a scanning light beam Cb emitted from a mirror 101 when the mirror 101 faces the front of the light deflector 18. The correction lens 19 decreases in refracting power radially with the distance from the center optical axis 33 in a center emission range set on an emission side of the correction lens 19 so as to include a part where the center optical axis 33 passes through the correction lens 19.SELECTED DRAWING: Figure 1

Description

The present invention relates to a vehicle headlight that irradiates an irradiation area in front of the vehicle using a scanning light beam.

Patent Document 1 discloses a vehicle headlight that generates a scanning light beam by a light deflector of MEMS (Micro Electro Mechanical Systems) and irradiates an irradiation region in front of the vehicle with the scanning light beam. According to the vehicle headlight, a light beam from a light source is incident on a mirror of an optical deflector, and the mirror is reciprocated around a rotation axis to generate a scanning light beam from the optical deflector. Exit. Then, the scanning light beam is wavelength-converted by the phosphor particles, and then is emitted toward the irradiation region in front of the vehicle through the projection lens.

Japanese Unexamined Patent Publication No. 2015-138735

The problems of the vehicle headlights of Patent Document 1 are as follows.
(A) If the scanning angle of the scanning light beam emitted when the rotation angle of the mirror of the optical deflector is the center of the rotation angle range is defined as 0 °, the image height generated in the irradiation region is the scanning angle. It is proportional to the absolute value. Therefore, even if the image heights of the central image and the edge image are the same in the original image, there is a difference in the reproduced image. That is, the reproduction quality is deteriorated.

(B) As a result of the scanning irradiation region being generated by the mirror of the optical deflector that reciprocates around the rotation axis, the scanning speed is high at the horizontal center portion of the irradiation region and slow at the horizontal end portion. As a result, the illuminance in the central portion in the horizontal direction becomes insufficient in the irradiation region.

An object of the present invention is firstly to control a change in image height related to the position of the scanning light beam in the scanning direction, and secondly to appropriately increase or decrease the scanning speed related to the position of the scanning light beam in the scanning direction. To provide headlights for use.

The vehicle headlight of the present invention
A light source that emits a light beam as an emission light beam,
An optical deflector having a mirror that reflects the emitted light beam incident from the light source, and an actuator that reciprocates the mirror around a rotation axis to emit a scanning light beam from the mirror.
A phosphor plate having an image plane in which the wavelength of the scanning light beam from the light deflector is changed by a phosphor and an image is generated by scanning the scanning light beam after the wavelength change.
A projection unit that projects the image on the image surface of the phosphor plate onto the irradiation area in front of the vehicle, and
The optical deflector is aligned with the central optical axis as the optical axis of the optical path of the central scanning light beam emitted at the central scanning angle corresponding to the central rotation position of the reciprocating rotation of the mirror around the rotation axis. A correction optical member that corrects the scanning light beam incident from the light beam and emits the scanning light beam onto the image plane of the phosphor plate.
With
The refractive power of the correction optical member is in the radial direction from the central optical axis in the central emission range set on the emission side of the correction optical member so that the central optical axis includes at least a portion passing through the correction optical member. It is set to decrease as you move away from.

According to the present invention, the refractive power of the correction optical member is centered in the radial direction in the central emission range set on the emission side of the correction optical member so that the central optical axis includes at least a portion passing through the correction optical member. It is set to decrease as it moves away from the optical axis. This makes it possible to suppress changes in the image height related to the position of the scanning light beam in the scanning direction.

Preferably, in the vehicle headlight of the present invention,
When the movement amount of the light spot in the scanning direction on the image plane of the phosphor plate with respect to the unit rotation angle of the mirror around the rotation axis is defined as the movement ratio.
The movement ratio is corrected so that the movement ratio becomes smaller as the light spot is located farther from the intersection in the central image range including at least the intersection of the central optical axis and the image plane. The optical member is set.

According to the present invention, the movement ratio is corrected so that the movement ratio becomes smaller as the light spot is located farther from the intersection in the central image range including at least the intersection of the central optical axis and the image plane. The members are set. As a result, the scanning speed of the scanning light beam in the vicinity of the intersection with the central optical axis on the image plane is reduced, and the illuminance of the region portion of the irradiation region corresponding to the vicinity can be increased.

Preferably, in the vehicle headlight of the present invention,
The correction optical member includes first and second lenses arranged on the light deflector side and the phosphor plate side, respectively.
The first lens enlarges the diameter of the scanning light beam in the scanning direction.
The second lens reduces the diameter of the scanning light beam in the scanning direction.

According to the present invention, the focal lengths on the light deflector side and the phosphor plate side with respect to the correction optical member can be shortened, and the light spot on the phosphor plate can be reduced.

Preferably, in the vehicle headlight of the present invention,
When the scanning light beam emitted from the correction optical member generates a rectangular irradiation region on the image plane, the rectangular irradiation region is set as the first figure.
A projection plane that is at the same position as the image plane on the central optical axis and is perpendicular to the central optical axis is set.
A projected figure obtained by projecting the first figure onto the projection plane in the direction of the central optical axis is defined as a second figure.
The scanning region generated on the projection surface by the scanning light beam emitted from the correction optical member is defined as a third figure.
The correction optical member is set so that the size and shape of the third figure match the size and shape of the second figure.

According to the present invention, the correction optical member is set so that the size and shape of the third figure match the size and shape of the second figure. As a result, the irradiation region generated on the image plane becomes rectangular, trapezoidal formation on the projection plane can be suppressed, and scanning position correction by the control device can be eliminated.

It is a schematic diagram of the whole headlight for a vehicle. It is a schematic front view of the light deflector. It is explanatory drawing of the runout angle and the scanning angle. It is a figure which shows the time change such as a scanning angle in one cycle of the reciprocating rotation of a mirror. It is a figure which shows the scanning light beam emitted from the mirror of an optical deflector at each scanning angle. It is a graph which shows the relationship between a scanning angle and an image height on an image plane by comparison with and without a correction lens. It is a graph which shows the relationship between a scanning angle and a scanning speed in comparison with the presence or absence of a correction lens. It is a graph which shows the relationship between the scanning position and the luminosity on the image plane by comparison with and without a correction lens. It is a schematic block diagram at the time of examining the light emission pattern generated at each position of the image plane of a phosphor plate in a vehicle headlight. FIG. 9 is a diagram showing an emission pattern generated by a scanning light beam at each coordinate position on the image plane with the configuration of FIG. 9. It is a block diagram of the main part of another vehicle headlight.

Hereinafter, preferred embodiments of the present invention will be described in detail. In the following description, common reference symbols are used for substantially the same or equivalent elements and parts.

(Overall)
FIG. 1 is an overall schematic view of the vehicle headlight 10. The vehicle headlight 10 includes a plurality of individual light beam generation units 11a and 11b and a single common projection unit 12, and is controlled by the control device 14.

Each individual light beam generation unit 11 (general term for individual light beam generation units 11a and 11b) includes an LD (laser diode) 16, an afocal converter 17 (general term for afocal converter 17a and afocal converter 17b), and an optical deflector 18. And a correction lens 19 (general term for correction lenses 19a and 19b). The common projection unit 12 includes a phosphor plate 23 and a projection lens 26 (general term for projection lenses 26a, 26b, 26c).

The LD16 emits a blue laser beam (eg, wavelength = 450 nm) as an emission light beam Ca. The afocal converter 17 irradiates the mirror 101 (FIG. 2) of the light deflector 18 with the emitted light beam Ca from the LD 16. The light deflector 18 converts the emitted light beam Ca into a scanning light beam Cb and emits it. The shape of the cross section and the scanning speed of the scanning light beam Cb are corrected by the correction lens 19, and then the scanning light beam Cb is incident on the surface side of the phosphor plate 23 of the common projection unit 12.

The control device 14 includes a light source switching unit 22a and an actuator driving unit 22b. The light source switching unit 22a switches the LD 16 on and off. The light source switching unit 22a changes the energizing current of the LD 16 during the ON period of the LD 16 so that the brightness of the LD 16 during the ON period can also be controlled. The actuator drive unit 22b applies the drive voltage of the inner actuator 103 (general name of the left and right inner actuators 103a and 103b: FIG. 2) and the outer actuator 105 (general name of the left and right outer actuators 105a and 105b: FIG. 2) of the optical deflector 18. Control.

The phosphor plate 23 has a mirror on the back surface side. The mirror reflects the scanning light beam Cb incident on the image plane 40 (FIG. 7) as the incident surface of the phosphor plate 23, and this time, the light beam Cc is emitted from the image surface 40 as the exit surface. The phosphor plate 23 encapsulates phosphor particles as a wavelength conversion member. When the scanning light beam Cb passes through the accommodating portion of the phosphor particles in the phosphor plate 23, some of the scanning light beams Cb excite the phosphor particles to convert the wavelength and change the color from blue to yellow. Be changed. As a result, the collective light beam Cc emitted from the exit surface of the phosphor plate 23 toward the projection lens 26a is emitted in white, which is a mixture of yellow and blue.

The collective light beam Cc then passes through a projection lens unit composed of a plurality of projection lenses 26, and irradiates the irradiation region in front of the vehicle as a projection light beam from the projection lens unit. In the irradiation region of the vehicle headlight 10, the light intensity becomes higher (brighter) as the irradiation region portion has a larger number of superposed light beams.

The central optical axis 33 is an optical path of a scanning light beam emitted when the mirror 101 has a rotation angle facing the front of the optical deflector 18 (swing angle α = 0 ° and swing angle β = 0 °, which will be described later). , Appropriately referred to as the "central optical path"). The correction lens 19 is arranged so that its optical axis is aligned with the central optical axis 33.

(Light deflector)
FIG. 2 is a schematic front view of the light deflector 18. For convenience of explaining the configuration of the optical deflector 18, a coordinate system including three axes, a Ux axis, a Uy axis, and a Uz axis, which are orthogonal to each other, is defined. The Ux axis and the Uy axis are aligned parallel to the horizontal and vertical directions of the light deflector 18, which is a rectangular shape in front view. Further, the Uz axis is aligned parallel to the plate thickness direction of the optical deflector 18.

The light deflector 18 has a horizontally long rectangular shape when viewed from the front, and is manufactured as a MEMS from a silicon crystal wafer. The optical deflector 18 includes a mirror 101, a torsion bar 102 (general term for the upper and lower torsion bars 102a, 102b), an inner actuator 103 (a generic term for the left and right inner actuators 103a, 103b), in order from the center Ao in the front view. It includes a movable frame 104, an outer actuator 105 (a general term for the left and right outer actuators 105a and 105b), and a fixed frame 106.

The circular mirror 101 is irradiated with the emitted light beam Ca at the center Ao. The inner actuator 103 surrounds the mirror 101 from the radial outside of the mirror 101. The movable frame 104 surrounds the inner actuator 103 from the outside in the radial direction. The torsion bar 102 extends in the Uy axis direction and is coupled to the mirror 101 and the movable frame 104 at both ends.

Each outer actuator 105 is composed of a plurality of cantilever 107s arranged in a meander arrangement and is interposed between the movable frame 104 and the fixed frame 106. The inner actuator 103 and the outer actuator 105 are both piezoelectric actuators.

The mirror 101 reciprocates in the biaxial directions of the first rotation axis Ah and the second rotation axis Av. At the runout angle α = 0 ° and the runout angle β = 0 °, which will be described later, the first rotation axis Ah and the second rotation axis Av coincide with the Uy axis and the Ux axis, respectively. The first rotation axis Ah coincides with the center line of the torsion bar 102 during reciprocating rotation around the two axes of the first rotation axis Ah and the second rotation axis Av of the mirror 101. The second rotation axis Av always coincides with the Ux axis during the reciprocating rotation around the two axes.

Since the resonance of the mirror 101 is used for the reciprocating rotation of the mirror 101 around the first rotation axis Ah, the frequency Fh of the reciprocating rotation becomes the resonance frequency. On the other hand, the reciprocating rotation of the mirror 101 around the second rotation axis Av is non-resonant, and the frequency Fv of the reciprocating rotation is a non-resonant frequency. Fv <Fh.

(Correction optical member)
The plurality of correction lenses 19 constitute a correction optical member. FIG. 3 is an explanatory diagram of a runout angle α and a scanning angle θ. The runout angle α is the rotation angle of the mirror 101 around the first rotation axis Ah. On the other hand, the runout angle β is the rotation angle of the mirror 101 around the second rotation axis Av. The deflection angles α and β of the mirror 101 when the mirror 101 faces directly in front of the light deflector 18 are both defined as 0 °.

The scanning angle θ in the horizontal direction is defined as the emission angle of each scanning light beam Cb with respect to the scanning light beam Cb emitted from the optical deflector 18 when the deflection angle α = 0 °. Therefore, the scanning angle θ = 0 ° is the scanning angle of the scanning light beam Cb emitted from the optical deflector 18 when the deflection angle α = 0 °. The central optical axis 33 of FIG. 1 coincides with the optical path of the scanning light beam Cb having a scanning angle θ = 0 °.

The test screen 35 is provided perpendicular to the central optical axis 33 at a predetermined distance from the light deflector 18. The scanning light beam Cb from the mirror 101 raster-scans on the test screen 35 and displays an image on the test screen 35. The distance d is the distance from the intersection of the central optical axis 33 and the test screen 35 to the scanning position of the scanning light beam Cb.

FIG. 4 shows the time change of the distance d in one cycle when the mirror 101 reciprocates at the frequency Fh and the luminous intensity of the light spot of the scanning light beam Cb on the test screen 35.

The scanning angle θ and the distance d change with a sine curve. The scanning speed of the scanning light beam Cb as the moving speed of the light spot on the test screen 35 is the time derivative value of the distance d. Since the mirror 101 reciprocates around the first rotation axis Ah, the scanning speed of the scanning light beam Cb becomes maximum at the scanning angle θ = 0 °, and becomes 0 at both ends of the fluctuation range of the scanning angle θ.

As a result, the luminous intensity of the light spot of the scanning light beam Cb on the test screen 35 is the minimum at the scanning angle θ = 0 ° at which the scanning speed is maximum, and is maximum at both ends of the fluctuation range of the scanning angle θ. In FIG. 4, since the maximum value of the luminosity is above the upper end of the graph area, the description is omitted.

FIG. 5 shows the optical path of the scanning light beam Cb when emitted from the mirror 101 of the light deflector 18 at each scanning angle θ. In FIG. 5, a total of seven scanning light beams Cb are shown. The central scanning light beam Cb is a scanning light beam Cb whose optical axis is the central optical axis 33, and corresponds to a scanning angle θ = 0 °.

The phosphor plate 23 in FIG. 5 is shown in a cross section that passes through the Oe of the image plane 40 (FIGS. 7 and 9) of the phosphor plate 23 and is along the horizontal direction. That is, it is cut along the horizontal cross section at the Oe position.

In FIG. 5, the scanning angles θ of the seven scanning light beams Cb are equiangular intervals. Of the seven beams, the scanning light beam Cb traveling along the central optical axis 33 (hereinafter referred to as “central scanning light beam Cb”) has a light spot on Oe (the intersection of the central optical axis 33 and the image plane 40). Generate. The three scanning light beams Cb on the right side in the horizontal direction with respect to the central scanning light beam Cb display light spots at intervals of Pr1, Pr2, and Pr3 in order from the scanning light beam Cb closer to the central scanning light beam Cb. Generate on 40. The three scanning light beams Cb on the left side in the horizontal direction with respect to the central scanning light beam Cb display light spots at intervals of Pl1, Pl2, and Pl3 in order from the scanning light beam Cb closer to the central scanning light beam Cb. Generate on 40.

The central scanning light beam Cb is a scanning light beam Cb when the scanning angle θ = 0 °. In FIG. 5, the scanning light beam Cb scans on the image plane 40 from right to left. Therefore, the light spot generated on the image surface 40 also scans on the image surface 40 from right to left. The scanning angle θ of each scanning light beam Cb becomes larger as the scanning light beam Cb on the left increases.

In FIG. 5, the three scanning light beams Cb on the left and right with respect to the central scanning light beam Cb are symmetrical with respect to the central scanning light beam Cb. Therefore, there is a relationship of Pr1 = Pl1, Pr2 = Pl2, Pr3 = Pl3. Further, 19 optical characteristics are set so that Pr1 <Pr2 <Pr3.

In other words, the movement amount of the optical spot in the scanning direction on the image surface 40 with respect to the unit amount of the swing angle α of the mirror 101 around the first rotation axis Ah (hereinafter, appropriately referred to as “unit rotation angle”) is defined as the movement ratio. When this is done, the optical characteristics of the correction lens 19 are set so that the movement ratio becomes smaller as the distance from the Oe increases. The optical characteristics of the correction lens 19 can be set, for example, by setting the geometric shape of the entrance surface or the exit surface of the correction lens 19. Further, in FIG. 5, the optical characteristics are set so as to occur over the entire radial direction of the correction lens 19, but the central image range as the central range including at least Oe on the image surface 40 is set. For example, it is good.

FIG. 6 is a graph showing the relationship between the scanning angle θ and the image height on the image plane 40 in comparison with and without the correction lens 19. FIG. 7 is a graph showing the relationship between the scanning angle θ and the scanning speed of the scanning angle θ on the image plane 40 in comparison with and without the correction lens 19. FIG. 8 is a graph showing the relationship between the scanning position d on the image plane 40 and the luminous intensity in comparison with and without the correction lens 19. Since the image height and the scanning speed are symmetrical with respect to the scanning angle θ, only the + side of the scanning angle θ is shown in these figures.

Note that the absence of the correction lens 19 means that neither the correction lens 19a nor 19b is present. Further, the vertical and horizontal directions of the image surface 40 correspond to the vertical direction and the horizontal direction of the irradiation region in front of the vehicle on which the vehicle headlight 10 is mounted. The image height means the vertical dimension of the image generated by the scanning light beam Cb at each scanning position on the image plane 40, that is, the image dimension in the direction orthogonal to the scanning direction.

In FIG. 6, when the correction lens 19 is not provided, the scanning angle θ and the image height are in a substantially proportional relationship. On the other hand, when the correction lens 19 is present, the image height does not exceed the image height when the correction lens 19 is not present, that is, is as follows.

Conversely, the optical characteristics of the correction lens 19 (for example, set by the geometric shapes of the entrance surface and the exit surface) are set so as to have a relationship with the correction lens 19 in FIG. There is. Specifically, for example, the correction optical member composed of the correction lens 19 decreases its refractive power as the distance from the central optical axis 33 increases in the radial direction (perpendicular to the central optical axis 33). It is set. This means that the difference in image height at each radial position with respect to the center image height is maintained low, at least in the central range as a predetermined radial range centered on the central optical axis 33. As a result, the quality of the image is improved, at least in the radial central range.

In the correction optical member, it is not necessary to set the refractive power to decrease as the distance from the central optical axis 33 increases in the radial direction over the entire radial direction of the correction optical member. It suffices that at least the central emission range is achieved so that the radial emission range includes at least the portion passing through the correction optical member.

In FIG. 7, when the correction lens 19 is not provided, the scanning speed gradually decreases as the scanning angle θ increases. On the other hand, when the correction lens 19 is present, the scanning speed is lower than the scanning speed without the correction lens 19 until the central optical axis 33 reaches at least an intermediate value of the scanning angle θ. As described in FIG. 5, this characteristic is realized by setting the optical characteristic of the correction lens 19 so that the movement ratio becomes smaller as the distance from the Oe increases.

In FIG. 8, in the central region of the image plane 40, the luminous intensity when the correction lens 19 is present exceeds the luminous intensity when the correction lens 19 is not present. As a result, in the vehicle headlight 10, when the irradiation region in front of the vehicle is irradiated with the collective light beam Cc, the luminous intensity of the central region corresponding to the central region of the vehicle width (in this case, also the illuminance) is set. It can be higher than the altitude of the surrounding area. That is, the central region can be made brighter than the both end regions in the horizontal and vertical directions.

FIG. 9 is a schematic configuration diagram when examining the light emission patterns generated at each position of the image plane 40 of the phosphor plate 23 in the vehicle headlight 10. Since the phosphor plate 23 is a reflection type wavelength converter, the scanning light beam Cb is incident from the front surface of the phosphor plate 23, reflected by the mirror on the back surface, and the color-converted collective light beam Cc. It emits from the surface. Since the image is generated on the surface of the phosphor plate 23 as the entrance surface and the exit surface of the phosphor plate 23, the image surface 40 becomes the surface of the phosphor plate 23.

As the vehicle headlight 10, a transmission type wavelength conversion device can also be used. In the transmission type wavelength converter, the scanning light beam Cb enters the phosphor plate 23 from the incident surface as one surface of the phosphor plate 23, with both surfaces of the phosphor plate 23 as the incident surface and the exit surface, respectively. , Exit from the exit surface as the other surface. Since the image is generated on both sides of the phosphor plate 23, the image surface 40 is one or the other surface of the phosphor plate 23.

For convenience of explanation, a two-axis coordinate system of x-axis-y-axis is defined with respect to the image plane 40. The origin o is defined as the intersection of two diagonal lines as the center of the rectangular image plane 40. The x-axis and y-axis are defined parallel to the horizontal side (horizontal side) and vertical side (vertical side) of the rectangular image plane 40, respectively.

In FIG. 9 and FIG. 10 below, the numbers circled indicate the coordinate positions on the image plane 40, and in the specification, "m" is added before the numbers for convenience of description.

In FIG. 9, the m1-m3 set, the m4-m6 set, and the m7-m9 set are at the same y-coordinate. In FIG. 9, the m1, m4, m7 set, the m2, m5, m8 set, and the m7-m9 set are at the same x-coordinate, respectively. The coordinate position of m4 is the origin o.

FIG. 10 shows an emission pattern generated by the scanning light beam Cb at each coordinate position of the image plane 40 in the configuration of FIG. In the table at the bottom of FIG. 9, the numerical values of x and y mean the x-coordinate and the y-coordinate (unit: mm) of m1-m9. Further, Spot_X and Spot_Y are horizontal and vertical dimensions (unit: μm) of the light emission pattern (light emission pattern of m1-m9 in FIG. 10) generated at each position of m1-m9.

In a typical vehicle headlight 10, the central optical axis 33 is not parallel to the normal line set on the image plane 40 but is inclined. That is, the scanning light beam Cb does not incident perpendicularly to the image plane 40, but incidents from an oblique direction. Therefore, in the conventional headlight for a vehicle, the two-dimensional scanning region in which the scanning light beam Cb is raster-scanned on the image plane 40 is located on the side closer to the incident side of the scanning light beam Cb in the vertical direction. It becomes a trapezoid that swells more than the sides. In order to deal with this, the vehicle headlight 10 has the following configuration.

FIG. 10 shows a light emission pattern when the correction lens 19 is set so that the scanning area generated by the scanning light beam Cb on the image plane 40 is rectangular. More specifically, when the scanning light beam Cb emitted from the correction lens 19 generates a rectangular irradiation region on the image plane 40, the rectangular irradiation region is designated as the first figure. A projection plane that is located on the central optical axis 33 at the same position as the image plane 40 and is perpendicular to the central optical axis 33 is set. The projected figure obtained by projecting the first figure onto the projection plane in the direction of the central optical axis 33 is defined as the second figure. The scanning region generated on the projection surface by the scanning light beam Cb emitted from the correction lens 19 is defined as the third figure.

In the vehicle headlight 10, the correction lens 19 is set so that the size and shape of the third figure match the size and shape of the second figure. As a result, the scanning region generated by the scanning light beam Cb on the image surface 40 is correctly rectangular even though the central optical axis 33 is inclined with respect to the image surface 40. That is, the trapezoidal shape is suppressed.

FIG. 11 is a block diagram of a main part of another vehicle headlight 50. For each element of the vehicle headlight 50, the element corresponding to the element of the vehicle headlight 10 is given a reference numeral assigned to the corresponding element of the vehicle headlight 10.

The vehicle headlight 50 includes individual light beam generation units 51a-51c. The configurations of the individual light beam generators 51a-51c are the same, only the relative positions with respect to the phosphor plate 23 are different.

The individual light beam generation unit 51 (general term for the individual light beam generation units 51a-51c) includes a prism 53a and a prism 53b. The prism 53a is interposed between the afocal converter 17 and the optical deflector 18 in the optical path of the emission irradiation region Ca. The prism 53b is interposed between the correction lens 19b and the phosphor plate 23 in the optical path of the scanning light beam Cb.

The axial dimension of the vehicle headlight 50 can be reduced by the prism 53 (general term for the prisms 53a-53c).

(Modification example)
In the embodiment, a piezoelectric actuator driven light deflector 18 is used to generate a scanning light beam. In the present invention, instead of this, an optical deflector of an electromagnetic type or electrostatic type actuator can be used.

10 ... Vehicle headlights, 11,51 ... Individual light beam generator, 12,52 ... Common projection unit, 14 ... Control device, 16 ... LD, 18 ... Light Deflector, 19 ... correction lens, 23 ... phosphor plate, 26 ... projection lens, 33 ... central optical axis, 40 ... image plane, 101 ... mirror, 103 ... Inner actuator (actuator).

Claims (4)

A light source that emits a light beam as an emission light beam,
An optical deflector having a mirror that reflects the emitted light beam incident from the light source, and an actuator that reciprocates the mirror around a rotation axis to emit a scanning light beam from the mirror.
A phosphor plate having an image plane in which the wavelength of the scanning light beam from the light deflector is changed by a phosphor and an image is generated by scanning the scanning light beam after the wavelength change.
A projection unit that projects the image on the image surface of the phosphor plate onto the irradiation area in front of the vehicle, and
The optical deflector is aligned with the central optical axis as the optical axis of the optical path of the central scanning light beam emitted at the central scanning angle corresponding to the central rotation position of the reciprocating rotation of the mirror around the rotation axis. A correction optical member that corrects the scanning light beam incident from the light beam and emits the scanning light beam to the image plane of the phosphor plate.
With
The refractive power of the correction optical member is in the radial direction from the central optical axis in the central emission range set on the emission side of the correction optical member so that the central optical axis includes at least a portion passing through the correction optical member. Vehicle headlights that are set to decrease as they move away from. In the vehicle headlight according to claim 1,
When the movement amount of the light spot in the scanning direction on the image plane of the phosphor plate with respect to the unit rotation angle of the mirror around the rotation axis is defined as the movement ratio.
The movement ratio is corrected so that the movement ratio becomes smaller as the light spot is located farther from the intersection in the central image range including at least the intersection of the central optical axis and the image plane. A vehicle headlight characterized by having an optical member set. In the vehicle headlight according to claim 1 or 2.
The correction optical member includes first and second lenses arranged on the light deflector side and the phosphor plate side, respectively.
The first lens enlarges the diameter of the scanning light beam in the scanning direction.
The second lens is a vehicle headlight characterized by reducing the diameter of the scanning light beam in the scanning direction. In the vehicle headlight according to any one of claims 1 to 3.
When the scanning light beam emitted from the correction optical member generates a rectangular irradiation region on the image plane, the rectangular irradiation region is set as the first figure.
A projection plane that is at the same position as the image plane on the central optical axis and is perpendicular to the central optical axis is set.
A projected figure obtained by projecting the first figure onto the projection plane in the direction of the central optical axis is defined as a second figure.
The scanning region generated on the projection surface by the scanning light beam emitted from the correction optical member is defined as a third figure.
A vehicle headlight characterized in that the correction optical member is set so that the size and shape of the third figure match the size and shape of the second figure.

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