CN210921231U - Light irradiation device - Google Patents

Abstract

The utility model provides a can realize the light irradiation device of the meticulous control of grading pattern. A light irradiation device (130) is provided with: a light source (32); and a rotatable mirror (134) that reflects light emitted from the light source (32), wherein the light is divided into a plurality of light beams and scanned linearly to form a light distribution pattern by shifting the direction of reflection of the light by the rotation of the mirror (134). The light distribution pattern includes a first line and a second line, and a width of the first line is different from a width of the second line.

Description

Light irradiation device

Technical Field

The utility model relates to a light irradiation device.

Background

In recent years, there has been devised a device for forming a predetermined light distribution pattern by reflecting light emitted from a light source toward the front of a vehicle and scanning an area in front of the vehicle with the reflected light. For example, an optical unit is known which includes: a plurality of light sources each including a light emitting element; a rotating reflector of a paddle scan (registered trademark) type reflects light emitted from a plurality of light sources on a reflecting surface while rotating in one direction around a rotation axis to form a desired light distribution pattern (see patent document 1). In the optical unit, the plurality of light sources are configured such that light emitted from each light source is reflected by different positions of the reflection surface of the rotating reflector.

Documents of the prior art

Patent document

Patent document 1: japanese laid-open patent publication No. 2015-26628

SUMMERY OF THE UTILITY MODEL

Technical problem to be solved by the utility model

In addition, an optical unit using a polygonal mirror instead of the rotating reflector is also known. In such an optical unit, there is room for improvement in the control of the light distribution pattern.

Therefore, an object of the present invention is to provide a light irradiation device capable of realizing fine control of a light distribution pattern.

Means for solving the problems

In order to solve the above problem, the present invention relates to a light irradiation device including: a light source; and a rotatable mirror that reflects light emitted from the light source, and that forms a light distribution pattern by dividing the light into a plurality of light distribution patterns and linearly scanning the light distribution patterns by shifting a reflection direction of the light due to rotation of the mirror, wherein the light irradiation device is characterized in that the light distribution pattern includes a first line and a second line, and a width of the first line is different from a width of the second line.

According to the above configuration, fine control of the light distribution pattern can be realized.

In the light irradiation device according to the present invention, the mirror may include at least: a first reflective surface for forming the first line; and a second reflecting surface arranged in a rotational direction of the mirror with respect to the first reflecting surface for forming the second line, a curvature of the first reflecting surface in a direction along a rotational axis of the mirror being different from a curvature of the second reflecting surface in the direction along the rotational axis.

According to the above configuration, the width of the first line and the width of the second line can be made different with a simple configuration.

In the light irradiation device according to the present invention, the first reflecting surface may be formed of a surface curved convexly in the direction, and the second reflecting surface may be formed of a surface curved concavely in the direction.

In the light irradiation device according to the present invention, the first reflecting surface and the second reflecting surface may be formed by surfaces curved convexly in the direction.

In the light irradiation device according to the present invention, the first reflecting surface and the second reflecting surface may be each formed of a surface curved concavely in the direction.

In the light irradiation device according to the present invention, the first reflecting surface may be formed of a surface curved convexly in the direction, and the second reflecting surface may be formed of a flat surface in the direction.

In the light irradiation device according to the present invention, the first reflecting surface may be a flat surface in the direction, and the second reflecting surface may be a surface concavely curved in the direction.

According to these configurations, by configuring the first reflecting surface and the second reflecting surface as described above, the width of the first line and the width of the second line can be easily made different.

In the light irradiation device according to the present invention, an inclination angle of the first reflecting surface with respect to the rotation axis of the mirror may be different from an inclination angle of the second reflecting surface with respect to the rotation axis.

According to the above configuration, the first line and the second line can be formed in different regions within the light distribution pattern.

In the light irradiation device according to the present invention, the second line may be disposed between the plurality of first lines, and a width of the second line may be narrower than a width of the plurality of first lines.

It is preferable to narrow the line width in the central region in the vertical direction of the light distribution pattern that particularly requires fine control. Further, since the brightness of the narrow line is increased when the rotation speed of the mirror is constant, only a predetermined region in the light distribution pattern can be brightened.

In the light irradiation device according to the present invention, the light irradiation device may further include an optical member through which the light reflected by the mirror passes, and an incident diameter of the light incident on the optical member may be different depending on the curvatures of the first reflecting surface and the second reflecting surface.

According to the above configuration, the width of the first line and the width of the second line in the light distribution pattern can be made different by making the incident diameters of the light incident on the optical member different from each other.

In the light irradiation device according to the present invention, the mirror may be a polygonal mirror.

The mirror is preferably a polygonal mirror.

Effect of the utility model

According to the present invention, it is possible to provide a light irradiation device capable of making a part of a light distribution pattern brighter than other parts.

Drawings

Fig. 1 is a horizontal sectional view of a vehicle headlamp.

Fig. 2 is a perspective view schematically showing the configuration of the optical unit according to the reference embodiment.

Fig. 3 is a top view of the optical unit of fig. 2.

Fig. 4 is a side view of the optical unit of fig. 2.

Fig. 5 is a side view showing a state in which the rotating mirror is rotated in the optical unit of fig. 4.

Fig. 6 is a schematic view showing an example of a light distribution pattern formed in front of a vehicle by the optical unit of fig. 2.

Fig. 7 is a plan view of the optical unit according to the first embodiment.

Fig. 8 is a side view of the optical unit of fig. 7.

Fig. 9 is a plan view showing a state in which the rotating mirror is rotated from the state of fig. 8 in the optical unit of fig. 7.

Fig. 10 is a schematic view showing an example of a light distribution pattern formed in front of a vehicle by the optical unit of fig. 7.

Fig. 11 is a side view of an optical unit according to a first modification.

Fig. 12 is a schematic view showing an example of a light distribution pattern formed in front of a vehicle by the optical unit of fig. 11.

Fig. 13 is a schematic view showing an example of a light distribution pattern formed in front of a vehicle by the optical unit according to the second modification.

Fig. 14 is a side view of an optical unit according to a third modification.

Description of the symbols

10 vehicle headlamp

Lamp unit for 20-low beam lamp

Lamp unit for 30 high beam lamp

32 light source

34. 134, 144 rotating mirror

36 plano-convex lens (projection lens)

38 fluorescent body

130. 140 lamp unit

134 a-134 f, 144 a-144 f reflecting surfaces

500 rotating mirror (rotating reflector)

501a blade (an example of a reflecting surface)

P1-P4 light distribution pattern

LA 1-LF 1, LA 2-LF 2, LA 3-LF 3 and LA 4-LF 4 lines

Detailed Description

The present invention will be described below based on embodiments with reference to the accompanying drawings. The same or equivalent constituent elements, members, and processes shown in the respective drawings are denoted by the same reference numerals, and overlapping descriptions are appropriately omitted. The embodiments are merely examples and do not limit the present invention, and all the features or combinations thereof described in the embodiments are not necessarily essential features of the present invention.

The "left-right direction", "front-back direction", and "up-down direction" in the present embodiment are relative directions set for the vehicle headlamp shown in fig. 1 for convenience of description. The "front-rear direction" is a direction including the "front direction" and the "rear direction". The "left-right direction" is a direction including the "left direction" and the "right direction". The "up-down direction" is a direction including the "up direction" and the "down direction".

The optical unit (an example of the light irradiation device) of the present invention can be used for various vehicle lamps. First, an outline of a vehicle headlamp capable of mounting an optical unit according to each embodiment described later will be described.

[ vehicle headlamp ]

Fig. 1 is a horizontal sectional view of a vehicle headlamp. Fig. 2 is a perspective view schematically showing a configuration of an optical unit mounted on the vehicle headlamp of fig. 1. Fig. 3 is a plan view of the optical unit, and fig. 4 and 5 are side views of the optical unit.

The vehicle headlamp 10 shown in fig. 1 is a right-side headlamp mounted on the right side of the front end of the vehicle, and has the same structure as the left-side headlamp except for being bilaterally symmetrical. Therefore, the right vehicle headlamp 10 will be described in detail below, and the left vehicle headlamp will not be described.

As shown in fig. 1, a vehicle headlamp 10 includes a lamp body (lamp body) 12, and the lamp body 12 has a recess that opens forward. The front opening of the lamp body 12 is covered with a transparent front cover 14 to form a lamp chamber 16. The lamp house 16 serves as a space in which the 2 lamp units 20, 30 are housed in a state of being arranged side by side in the vehicle width direction.

Of the lamp units 20 and 30, the lamp unit disposed on the inner side in the vehicle width direction, that is, the lower lamp unit 20 shown in fig. 1 of the vehicle headlamp 10 disposed on the right side is configured to emit low beam. In contrast, the lamp unit arranged on the outer side in the vehicle width direction, that is, the lamp unit 30 arranged on the upper side in fig. 1 of the right vehicle headlamp 10, among the lamp units 20 and 30, is a lamp unit provided with a lens 36 and configured to irradiate variable high beam.

The low-beam lamp unit 20 has a reflector 22 and a light source 24, which is formed, for example, from an LED. The reflector 22 and the LED light source 24 are supported to be tiltable with respect to the lamp body 12 by a conventional means not shown, for example, by means using an alignment screw and a nut.

(reference embodiment)

As shown in fig. 2 to 5, the lamp unit 30 for a high beam lamp according to the reference embodiment includes: a light source 32; a rotating mirror 34 as a reflector; a plano-convex lens 36 as a projection lens disposed in front of the rotating mirror 34; and a phosphor 38 disposed between the rotating mirror 34 and the plano-convex lens 36.

As the light source 32, for example, a laser light source can be used. Instead of the laser light source, a semiconductor light emitting element such as an LED or an EL element may be used as the light source. The light source 32 can be controlled to be turned on or off by a light source control unit, not shown. In particular, in the control of the light distribution pattern described later, it is preferable to use a light source control unit that can perform lighting and extinguishing accurately in a short time. For example, by at least one Electronic Control Unit (ECU). The electronic control unit may comprise: at least one microcontroller comprising one or more processors and one or more memories; and other circuits including active elements such as transistors and passive elements. The processor is, for example, a CPU (Central Processing Unit), an MPU (Micro Processing Unit), and/or a GPU (graphics Processing Unit). The Memory includes a ROM (Read Only Memory) and a RAM (Random Access Memory). The control program of the lamp unit 30 may also be stored in the ROM.

The shape of the plano-convex lens 36 may be appropriately selected according to the light distribution characteristics such as a desired light distribution pattern and illumination intensity distribution, and an aspherical lens or a free-form lens may be used. The rear focal point of the plano-convex lens 36 is set, for example, in the vicinity of the light exit surface of the phosphor 38. Thereby, the light image on the light emitting surface of the fluorescent material 38 is vertically inverted and is irradiated forward.

The phosphor 38 is made of, for example, a resin material mixed with phosphor powder that is excited by the blue laser light emitted from the light source 32 to emit yellow light. The blue laser light and the yellow fluorescent light are mixed, and the laser light emitted from the fluorescent material 38 becomes white light.

The rotary mirror 34 is rotatably connected to a motor 40 as a drive source. The rotary mirror 34 is rotated in the rotation direction D around the rotation axis R by a motor 40. The rotation axis R of the rotating mirror 34 is inclined with respect to the optical axis Ax (see fig. 4). The rotating mirror 34 is configured by a plurality of (12 in this example) reflecting surfaces 34a to 34l arranged along the rotating direction D. The reflection surfaces 34a to 34l of the rotating mirror 34 reflect the light emitted from the light source 32 while rotating. Thereby, as shown in fig. 4, the light of the light source 32 can be used for scanning. The rotating mirror 34 is, for example, a polygonal mirror having a 12-sided reflection surface formed into a polygon.

Here, of the reflection surfaces 34A to 34h, the reflection surface 34A and the reflection surface 34g located on the opposite side of the diagonal line of the reflection surface 34A are referred to as a first reflection surface pair 34A. The reflection surface 34B and the reflection surface 34h located on the opposite side of the diagonal line of the reflection surface 34B are set as a second reflection surface pair 34B. The reflection surface 34C and the reflection surface 34i located on the opposite side of the diagonal line of the reflection surface 34C are set as a third reflection surface pair 34C. The reflection surface 34D and the reflection surface 34j located on the opposite side of the diagonal line of the reflection surface 34D are set as a fourth reflection surface pair 34D. The reflecting surface 34E and the reflecting surface 34k located on the opposite side of the diagonal line of the reflecting surface 34E are set as a fifth reflecting surface pair 34E. The reflection surface 34F and the reflection surface 34l located on the opposite side of the diagonal line of the reflection surface 34F are defined as a sixth reflection surface pair 34F.

The first reflecting surface pair 34A is formed such that an angle θ a formed by the optical axis Ax and the reflecting surface 34A of the surface configured by the up-down direction and the front-rear direction when the laser light emitted from the light source 32 is reflected by the reflecting surface 34A (that is, when the first reflecting surface pair 34A is in the arrangement relationship shown in fig. 3 and 4) is substantially the same as an angle formed by the optical axis Ax and the reflecting surface 34g of the surface configured by the up-down direction and the front-rear direction when the laser light emitted from the light source 32 is reflected by the reflecting surface 34 g. Similarly, the second reflecting surface pair 34B is formed such that the angle θ B formed by the optical axis Ax and the reflecting surface 34B in the plane formed by the up-down direction and the front-rear direction when the laser light emitted from the light source 32 is reflected by the reflecting surface 34B (that is, in the arrangement shown in fig. 5) is substantially the same as the angle formed by the optical axis Ax and the reflecting surface 34h in the plane formed by the up-down direction and the front-rear direction when the laser light emitted from the light source 32 is reflected by the reflecting surface 34 h. The third reflecting surface pair 34C is formed such that the angle formed by the reflecting surface 34C and the optical axis Ax when the laser light emitted from the light source 32 is reflected by the reflecting surface 34C is substantially the same as the angle formed by the reflecting surface 34i and the optical axis Ax when the laser light emitted from the light source 32 is reflected by the reflecting surface 34 i. The fourth reflecting surface pair 34D is formed such that the angle formed by the reflecting surface 34D and the optical axis Ax when the laser light emitted from the light source 32 is reflected by the reflecting surface 34D is substantially the same as the angle formed by the reflecting surface 34j and the optical axis Ax when the laser light emitted from the light source 32 is reflected by the reflecting surface 34 j. The fifth reflecting surface pair 34E is formed such that the angle formed by the optical axis Ax and the reflecting surface 34E when the laser light emitted from the light source 32 is reflected by the reflecting surface 34E is substantially the same as the angle formed by the optical axis Ax and the reflecting surface 34k when the laser light emitted from the light source 32 is reflected by the reflecting surface 34 k. The sixth reflecting surface pair 34F is formed such that angles formed by the reflecting surfaces 34F, 34l and the optical axis Ax are substantially the same when the laser light emitted from the light source 32 is reflected. That is, the reflection surfaces 34a to 34l of the rotating mirror 34 are formed as inclined surfaces in which a pair of reflection surfaces located on diagonal lines have the same angle with each other. Thus, the light reflected by the pair of reflection surfaces constituting the first to sixth reflection surface pairs 34A to 34F is irradiated at substantially the same position in the vertical direction in front of the vehicle. Further, the wobbling of the rotary mirror 34 when the rotary mirror 34 is rotated in the rotation direction D by the motor 40 can be prevented.

An angle θ a formed by the first reflecting surface pair 34A and the optical axis Ax when the laser light emitted from the light source 32 is reflected by the first reflecting surface pair 34A is formed to be different from angles formed by the respective reflecting surfaces of the other reflecting surface pairs 34B to 34F and the optical axis Ax when the laser light emitted from the light source 32 is reflected by the other reflecting surface pairs 34B to 34F. For example, an angle θ b formed by the reflection surface 34b and the optical axis Ax shown in fig. 5 is formed to be slightly smaller than an angle θ a formed by the reflection surface 34a and the optical axis Ax shown in fig. 4. Similarly, the angles formed by the respective reflection surface pairs and the optical axis Ax are formed to be smaller in the order of the second reflection surface pair 34B, the third reflection surface pair 34C, the fourth reflection surface pair 34D, the fifth reflection surface pair 34E, and the sixth reflection surface pair 34F. Thus, the light reflected by one reflecting surface pair is irradiated at a position different from the other reflecting surfaces in the up-down direction in front of the vehicle. For example, the light Lb reflected by the reflection surface 34b is irradiated above the light La reflected by the reflection surface 34a on an imaginary vertical screen in front of the vehicle.

The light reflected by the respective reflection surfaces 34a to 341 of the rotating mirror 34 configured as described above and transmitted through the planoconvex lens 36 via the fluorescent body 38 forms a light distribution pattern P1 as shown in fig. 6 on a virtual vertical screen at a predetermined position in front of the vehicle (for example, 25m in front of the vehicle). Specifically, the light reflected by the first reflecting surface pair 34A (the reflecting surfaces 34A and 34g) forms the lowermost line LA1 in the light distribution pattern P1 shown in fig. 6. In addition, a line LB1 is formed above the line LA1 by the light reflected by the second reflection surface pair 34B (reflection surfaces 34B, 34 h). The line LC1 is formed on the upper side of the line LB1 with the light reflected by the third reflection surface pair 34C (reflection surfaces 34C, 34 i). The line LD1 is formed on the upper side of the line LC1 with the light reflected by the fourth reflection surface pair 34D (reflection surfaces 34D, 34 j). A line LE1 is formed on the upper side of the line LD1 by the light reflected by the fifth reflection surface pair 34E (reflection surfaces 34E, 34 k). The line LF1 is formed above the line LE1 by the light reflected by the sixth reflection surface pair 34F (reflection surfaces 34F, 34 l). As described above, the light is divided into a plurality of light beams and linearly scanned by shifting the reflection direction of the light by the rotation of the rotating mirror 34, thereby forming the light distribution pattern P1.

When the laser light emitted from the light source 32 is reflected by the boundaries between the reflecting surfaces 34a to 34l, the laser light may be scattered and an inappropriate light distribution may be formed. Therefore, it is preferable that the light source control unit controls turning on and off of the light source 32 so that the light source 32 is turned off at a timing when the boundary between the reflecting surfaces 34a to 34l intersects with the beam of the laser light emitted from the light source 32.

In the lamp unit 30 according to the reference embodiment, the light source 32 is relatively small, and the light source 32 is disposed at a position that is also between the rotating mirror 34 and the plano-convex lens 36 and is offset from the optical axis Ax. Therefore, the length of the vehicle headlamp 10 in the vehicle front-rear direction can be shortened as compared with a case where the light source, the reflector, and the lens are aligned on the optical axis as in the conventional projection type lamp unit.

(first embodiment)

Fig. 7 is a plan view of the lamp unit 130 according to the first embodiment. Fig. 8 and 9 show side views of the lamp unit 130.

The lamp unit 130 shown in fig. 7 includes: a light source 32, a rotating mirror 134, a plano-convex lens 36 (an example of an optical member), and a fluorescent body 38 (an example of an optical member).

The rotating mirror 134 of the first embodiment is configured by a plurality of (6 in this example) reflecting surfaces 134a to 134f arranged in a row along the rotating direction D.

As shown in fig. 8, the reflecting surface 134a (an example of the first reflecting surface) is formed as a convexly curved surface that is curved so as to protrude outward in a direction along the rotation axis R of the rotating mirror 134. Similarly, as shown in fig. 9, the reflecting surface 134f is formed as a convexly curved surface that is curved so as to protrude outward in the direction along the rotation axis R. Although not shown in the drawings, the reflecting surfaces 134b and 134e are also formed as convexly curved surfaces that are curved so as to protrude outward in the direction along the rotation axis R. As shown in fig. 9, the reflection surface 134c (an example of the second reflection surface) is formed as a concave curved surface that is curved so as to be concave toward the rotation axis R in the direction along the rotation axis R. Similarly, as shown in fig. 8, the reflection surface 134d is also formed as a concave curved surface that is curved so as to be concave toward the rotation axis R in the direction along the rotation axis R.

As shown in fig. 7, the reflecting surfaces 134a to 134f are formed in a planar shape without being curved in the rotation direction D (in a plan view).

Therefore, the laser light La reflected by the reflecting surface 134a which is a convexly curved surface is more diffused in the vertical direction than the diameter of the laser light when emitted from the light source 32 (see fig. 8). Similarly, the laser beams reflected by the reflecting surfaces 134b, 134e, and 134f, which are convex curved surfaces, are more diffused in the vertical direction than the diameter of the laser beams when emitted from the light source 32. On the other hand, the laser light Lc reflected by the reflecting surface 134c, which is a concave curved surface, is more concentrated in the vertical direction than the diameter of the laser light when emitted from the light source 32 (see fig. 9). Similarly, the laser light reflected by the reflecting surface 134d, which is a concave curved surface, is more concentrated in the vertical direction than the diameter of the laser light when emitted from the light source 32. Accordingly, the incident diameter (for example, incident diameter xa shown in fig. 8) of the laser light reflected by the reflecting surfaces 134a, 134b, 134e, and 134f, which are the convex curved surfaces, when entering the fluorescent material 38 is larger than the incident diameter (for example, incident diameter xb shown in fig. 9) of the laser light reflected by the reflecting surfaces 134c and 134d, which are the concave curved surfaces, when entering the fluorescent material 38.

An angle formed by the optical axis Ax and a virtual straight line ya (see fig. 8) connecting both end portions in the vertical direction of the reflecting surface 134a when the laser light emitted from the light source 32 is reflected by the reflecting surface 134a is formed to be different from an angle formed by the optical axis Ax and a virtual straight line connecting both end portions in the vertical direction of the other reflecting surfaces 134b to 134f when the laser light emitted from the light source 32 is reflected by the other reflecting surfaces 134b to 134f (see fig. 4 and 5). In the example of fig. 8, the virtual straight line ya coincides with the boundary line between the reflection surface 134a and the reflection surface 134 b. For example, an angle formed by an imaginary straight line connecting both ends in the vertical direction of the reflecting surface 134b and the optical axis Ax is formed to be slightly smaller than an angle formed by the imaginary straight line ya of the reflecting surface 134a and the optical axis Ax. An angle formed by the optical axis Ax and a virtual straight line yc (see fig. 9) connecting both ends of the reflection surface 134c in the vertical direction is formed to be slightly smaller than an angle formed by the optical axis Ax and a virtual straight line of the reflection surface 134 b. Similarly, the angle formed by the optical axis Ax and a virtual straight line connecting the vertical directions of the respective reflection surfaces is formed to be smaller in the order of the reflection surface 134d, the reflection surface 134e, and the reflection surface 134 f. Thus, the laser light reflected by one reflecting surface is irradiated to a position different from the other reflecting surfaces in the vertical direction in front of the vehicle. For example, the laser light reflected by the reflecting surface 134b is irradiated above the laser light La reflected by the reflecting surface 134a on the virtual vertical screen in front of the vehicle. The laser light Lc reflected by the reflecting surface 134c is irradiated above the laser light Lc reflected by the reflecting surface 134b on the virtual vertical screen.

Fig. 10 shows a light distribution pattern P2 formed on a virtual screen in front of the vehicle (for example, 25mm in front) by the lamp unit 130 according to the first embodiment.

As shown in fig. 10, the light distribution pattern P2 includes a plurality of lines (LA2 to LF2) formed by laser light. The laser light emitted from the light source 32 is reflected by the reflection surfaces 134a to 134f of the rotating mirror 134, and is transmitted through the plano-convex lens 36 via the fluorescent body 38. Since the rear focal point of the plano-convex lens 36 is set on the light emitting surface of the phosphor 38 as in the reference embodiment, the light image of the light emitting surface of the phosphor 38 is irradiated forward while being inverted vertically.

Specifically, the laser light reflected by the reflection surface 134a forms the lowermost line LA2 in the light distribution pattern P2 shown in fig. 10. Further, a line LB2 is formed above the line LA2 by the laser light reflected by the reflection surface 134 b. The laser beam reflected by the reflecting surface 134c forms a line LC2 above the line LB 2. The laser light reflected by the reflection surface 134d forms a line LD2 above the line LC 2. The laser beam reflected by the reflecting surface 134e forms a line LE2 above the line LD 2. The laser beam reflected by the reflection surface 134f forms a line LF2 above the line LE 2.

As described above, the incident diameter xa of the laser light reflected by the reflecting surfaces 134a, 134b, 134e, and 134f, which are the convex curved surfaces, when incident on the fluorescent material 38 is larger than the incident diameter xb of the laser light reflected by the reflecting surfaces 134c and 134d, which are the concave curved surfaces, when incident on the fluorescent material 38. Therefore, the vertical width w2 of the third line LC2 and the fourth line LD2 from below is narrower than the vertical width w1 of the first line LA2, the second line LB2, the fifth line LE2, and the sixth line LF2 from below.

The vertical width w1 of the first line LA2, the second line LB2, the fifth line LE2, and the sixth line LF2 from below is wider than the vertical width of the lines LA1 to LF1 formed by the laser light reflected by the respective reflecting surfaces 34a to 34l of the rotating mirror 34 of the reference embodiment shown in fig. 4 and 5, which are planar along the direction of the rotation axis R. This is because, as described above, the laser light reflected by the reflecting surfaces 134a, 134b, 134e, and 134f, which are the convexly curved surfaces, is more diffused in the vertical direction than the diameter of the laser light when emitted from the light source 32. Further, the vertical width w2 of the third line LC2 and the fourth line LD2 from the bottom is narrower than the vertical width of the lines LA1 to LF1 formed by the laser light reflected by the respective reflection surfaces 34a to 34l of the rotating mirror 34 of the reference embodiment. This is because, as described above, the laser beams reflected by the reflecting surfaces 134c and 134d, which are concave curved surfaces, are more concentrated in the vertical direction than the diameter of the laser beams when emitted from the light source 32.

The adjacent lines LA2 to LF2 may be formed to overlap each other by a certain amount. In this case, for example, the overlapping amount of the lines LA2 to LF2 in the vertical direction is about 10% of the line width W1 (or the line width W2). Specifically, for example, the overlapping amount of the line LA2 and the line LB2 is preferably about 10% of the width w1 of the lines LA2 and LB 2. The overlapping amount of the line LB2 and the line LC2 is preferably about 10% of the width w1 of the line LB2 or about 10% of the width w2 of the line LC 2. The overlapping amount of the line LC2 and the line LD2 is preferably about 10% of the width w2 of the lines LC2 and LD 2. The overlapping amount of line LD2 and line LE2 is preferably about 10% of the width w2 of line LD2, or about 10% of the width w1 of line LE 2. The overlap of line LE2 and line LF2 is preferably about 10% of the width w1 of lines LE2 and LF 2.

At the boundary between the reflecting surfaces 134a to 134f, there is a possibility that the laser light is scattered to form an inappropriate light distribution, as in the above-described reference embodiment. Therefore, it is preferable that the light source control unit controls turning on and off of the light source 32 so that the light source 32 is turned off at a timing when the boundary between the reflecting surfaces 134a to 134f intersects with the beam of the laser light emitted from the light source 32.

In this example, the rotating mirror 134 is configured by a polygonal mirror having 6 planes, but the present invention is not limited to this. For example, the mirror may be a polygonal mirror having 12 surfaces as in the reference embodiment, and a pair of reflection surfaces located on diagonal lines may have the same curvature and the same inclination angle in the direction along the rotation axis R. Thus, the lines LA2 to LF2 are repeatedly formed by the laser light reflected by the pair of reflection surfaces located on the diagonal lines.

Incidentally, in a scanning optical system used for a vehicle headlamp, it is sought to enhance the luminance of a light distribution pattern while controlling a light irradiation range and a light shielding range with high accuracy. For example, when an ADB (adaptive driving Beam) system is used as the scanning optical system, it is required to irradiate light to a vicinity limit of a peripheral vehicle to be shielded. In addition, when the scanning optical system is used for road surface drawing, it is required to finely control the road surface irradiation range. However, if all the lines constituting the light distribution pattern are intended to be made thin, a large number of light sources are required, and the efficiency for forming a desired light distribution pattern is reduced, which is not practical.

In contrast, according to the lamp unit 130 according to the first embodiment, the rotating mirror 134 includes: reflection surfaces 134a, 134b, 134e, and 134f (an example of a first reflection surface) which are lines LA2, LB2, LE2, and LF2, which are lines for forming both side portions in the vertical direction of the light distribution pattern P2; and reflection surfaces 134c and 134d (an example of a second reflection surface) for forming lines LC2 and LD2, which are lines at the center in the vertical direction of the light distribution pattern P2. The curvature of the reflecting surfaces 134a, 134b, 134e, 134f in the direction along the rotation axis R is different from the curvature of the reflecting surfaces 134c, 134d in the direction along the rotation axis R. Specifically, the reflecting surfaces 134a, 134b, 134e, and 134f are formed as convexly curved surfaces that protrude outward in the direction along the rotation axis R, and the reflecting surfaces 134c and 134d are formed as concavely curved surfaces that are concave inward in the direction along the rotation axis R. Therefore, according to the configuration of the lamp unit 130, the diffusion angle of the laser light reflected by the reflecting surfaces 134a, 134b, 134e, and 134f in the vertical direction is wider than the diffusion angle of the laser light reflected by the reflecting surfaces 134c and 134d in the vertical direction. Thus, as shown in fig. 10, the vertical width w2 of the lines LC2 and LD2 in the center portion can be made narrower than the vertical width w1 of the lines LA2, LB2, LE2, and LF2 in the both side portions.

By making the vertical widths of the lines LC2, LD2 (an example of the second line) narrower than the vertical widths of the lines LA2, LB2, LE2, LF2 (an example of the first line) in this way, it is possible to achieve fine control of the light distribution pattern P2 in the central region in the vertical direction of the light distribution pattern P2. When the rotation speed of the rotating mirror 134 is constant, the narrow lines LC2 and LD2 have higher brightness than the wide lines LA2, LB2, LE2, and LF 2. Therefore, only the central region can be made bright in the light distribution pattern P2. Note that the widths of lines LC2 and LD2 at the center in the vertical direction in the light distribution pattern P2 formed by the rotating mirror 134 of the present embodiment are narrower than the widths of the lines LA1 to LF1 of the light distribution pattern P1 formed by the rotating mirror 34 of the reference embodiment, and the widths of the lines LA2, LB2, LE2, and LF2 other than the center in the vertical direction are wider than the widths of the lines LA1 to LF1 formed by the rotating mirror 34 of the reference embodiment. Therefore, according to the configuration of the present embodiment, it is possible to form the light distribution pattern P2, and the light distribution pattern P2 has the same vertical width as the light distribution pattern P1 of the reference embodiment, and it is possible to finely control the central region.

In the above-described embodiment, the reflecting surfaces 134a, 134b, 134e, and 134f of the rotating mirror 134 are formed as convexly curved surfaces, and the reflecting surfaces 134c and 134d are formed as concavely curved surfaces, but the present invention is not limited to this example. All the reflecting surfaces may be formed as convex curved surfaces or concave curved surfaces, and the curvatures of the convex curved surfaces or the concave curved surfaces may be made different for each reflecting surface. For example, when all the reflecting surfaces are formed as convex curved surfaces, the radius of curvature of the reflecting surface (convex curved surface) for forming a line having a narrow width is preferably set to be larger than the radius of curvature of the reflecting surface (convex curved surface) for forming a line having a wide width. That is, the curvature of the reflecting surface (convex curved surface) for forming a narrow line is preferably set smaller than the curvature of the reflecting surface (convex curved surface) for forming a wide line. In the case where all the reflecting surfaces are formed as the concavely curved surfaces, it is preferable that the radius of curvature of the reflecting surface (concavely curved surface) for forming the narrow lines is set smaller than the radius of curvature of the reflecting surface (concavely curved surface) for forming the wide lines. That is, the curvature of the reflecting surface (concavely curved surface) for forming the narrow line is preferably set to be larger than the curvature of the reflecting surface (concavely curved surface) for forming the wide line. With this configuration, the vertical width can be made different for each line.

Next, a modification of the lamp unit 130 according to the first embodiment will be described.

(first modification)

Fig. 11 shows a side view of a lamp unit 140 according to a first modification.

As shown in fig. 11, the lamp unit 140 includes: a light source 32, a turning mirror 144, a plano-convex lens 36, and a phosphor 38.

The rotating mirror 144 of the lamp unit 140 is composed of a plurality of (6 in this example) reflecting surfaces 144a to 144f arranged in line in the rotating direction D, as in the rotating mirror 134 of the first embodiment. In the present modification, as in the first embodiment, the reflecting surfaces 144a and 144f are formed as convexly curved surfaces that protrude outward in the direction along the rotation axis R. In addition, as in the first embodiment, the reflection surfaces 144c and 144d are also formed as concavely curved surfaces that are concave toward the rotation axis R. On the other hand, the reflecting surfaces 144b and 144e are formed to be flat in the direction along the rotation axis R (see fig. 11).

An angle formed by an optical axis Ax and a virtual straight line connecting both end portions in the vertical direction of the reflecting surface 144a when the laser light emitted from the light source 32 is reflected by the reflecting surface 144a is formed to be different from an angle formed by an optical axis Ax and a virtual straight line connecting both end portions in the vertical direction of the other reflecting surfaces 144b to 144f when the laser light emitted from the light source 32 is reflected by the other reflecting surfaces 144b to 144f (see fig. 4 and 5). For example, the angle formed by the reflecting surface 144b and the optical axis Ax is formed to be slightly smaller than the angle formed by the optical axis Ax and a virtual straight line connecting both ends of the reflecting surface 144a in the vertical direction. Similarly, the angle formed by the optical axis Ax and a virtual straight line connecting both ends of each reflecting surface in the vertical direction becomes smaller in the order of the reflecting surface 144c, the reflecting surface 144d, the reflecting surface 144e, and the reflecting surface 144 f. Thus, the light reflected by one reflecting surface is irradiated to a position different from the light reflected by the other reflecting surface in the vertical direction in front of the vehicle. For example, the light reflected by the reflecting surface 144b is irradiated above the light reflected by the reflecting surface 144a on the virtual vertical screen in front of the vehicle. The light reflected by the reflecting surface 144c is irradiated on the virtual vertical screen above the light reflected by the reflecting surface 144 b.

Fig. 12 shows a light distribution pattern P3 formed in front of the vehicle by the lamp unit 140 according to the first modification.

As shown in fig. 12, the light distribution pattern P3 includes a plurality of lines (LA3 to LF3) formed by laser light. The laser light emitted from the light source 32 is reflected by the reflecting surfaces 144a to 144f of the rotating mirror 144, and is transmitted through the plano-convex lens 36 via the fluorescent material 38. As in the reference embodiment, the rear focal point of the planoconvex lens 36 is set on the light emitting surface of the phosphor 38, and therefore, the light image of the light emitting surface of the phosphor 38 is irradiated forward while being inverted up and down.

Specifically, the lowermost line LA3 in the light distribution pattern P3 shown in fig. 12 is formed by the laser light reflected by the reflection surface 144 a. Further, a line LB3 is formed above the line LA3 by the laser beam reflected by the reflecting surface 144 b. The laser beam reflected by the reflecting surface 144c forms a line LC3 above the line LB 3. The laser beam reflected by the reflecting surface 144d forms a line LD3 above the line LC 3. The laser beam reflected by the reflecting surface 144e forms a line LE3 above the line LD 3. The laser beam reflected by the reflecting surface 144f forms a line LF3 above the line LE 3. The lines LA3 to LF3 are all formed to have the same length in the horizontal direction.

The vertical width w3 of the second line LB3 from the bottom and the fifth line LE3 from the bottom in the light distribution pattern P3 is narrower than the vertical width w1 of the first (lowermost) line LA3 from the bottom and the sixth (uppermost) line LF3 from the bottom. In addition, the top-bottom width w2 of the third line LC3 from below and the fourth line LD3 from below is narrower than the top-bottom width w3 of the second line LB3 from below and the fifth line LE3 from below.

In this way, the rotating mirror 144 of the lamp unit 140 according to the first modification is formed such that the reflecting surfaces 144a and 144f are convexly curved surfaces in the direction along the rotation axis R, the reflecting surfaces 144b and 144e are flat surfaces in the direction along the rotation axis R, and the reflecting surfaces 144c and 144d are concavely curved surfaces in the direction along the rotation axis R. Thus, the light distribution pattern P3 formed by the laser light reflected by the reflection surfaces 144a to 144f is formed by a plurality of lines LA3 to LF3 whose vertical widths are gradually narrowed toward the center in the vertical direction. With this configuration, it is possible to realize further fine control of the light distribution pattern and to improve the luminance in the central region in the vertical direction of the light distribution pattern P3.

In the first modification described above, the respective reflection surfaces 144a to 144f of the rotating mirror 144 are formed as any one of a convex curved surface, a flat surface, and a concave curved surface, but the present invention is not limited to this example. The reflection surface for forming the wide line may be formed as a flat surface, and the reflection surface for forming the narrow line may be formed as a concavely curved surface. Further, the reflective surface for forming the wide line may be formed as a convex curved surface, and the reflective surface for forming the narrow line may be formed as a flat surface. By configuring the plurality of reflecting surfaces by a combination of the convex curved surface, the concave curved surface, and the flat surface in this manner, the vertical width of the line forming the light distribution pattern can be made different in the same manner as in the first modification.

In the first modification, the control of turning on and off the light source at the boundary between the reflecting surfaces, the number of reflecting surfaces constituting the rotating mirror, the inclination angle thereof, and the lines of the light distribution pattern formed by which reflecting surface is used are the same as those of the lamp unit 130 according to the first embodiment.

(second modification)

Fig. 13 shows a light distribution pattern P4 formed in front of the vehicle by the lamp unit according to the second modification.

In the above embodiment, the following configuration is adopted: the laser beams reflected by the reflection surfaces 134a to 134f of the rotating mirror 134 form lines at different positions of the light distribution pattern, but the present invention is not limited to this example. For example, a light distribution pattern P4 can be formed as shown in fig. 13 by repeatedly scanning a line in a part of the vertical direction with light reflected by at least two of the plurality of reflection surfaces 134a to 134f of the rotating mirror 134. In this case, for example, the angle formed by the optical axis Ax and a virtual straight line connecting both ends in the vertical direction of the reflection surface 134c is set to be substantially the same as the angle formed by the optical axis Ax and a virtual straight line connecting both ends in the vertical direction of the reflection surface 134 b. An angle formed by a virtual straight line connecting both ends in the vertical direction of the reflecting surface 134d and the optical axis Ax is set to be substantially the same as an angle formed by a virtual straight line connecting both ends in the vertical direction of the reflecting surface 134e and the optical axis Ax. Thus, the light distribution pattern P4 includes: lines LA4, LB4, LE4, LF4 having the same top and bottom widths; a line LC4 formed repeatedly with a part of the line LB4 and having a narrower top-bottom width than the line LB 4; and a line LD4 formed repeatedly with a portion of line LE4 and having a narrower top-to-bottom width than line LE 4. In this way, by forming at least some of the plurality of lines LA4 to LF4 forming the light distribution pattern P4 so as to overlap with other lines, it is possible to achieve finer control of the light distribution pattern and to improve the luminance of a specific region of the light distribution pattern.

(third modification)

Fig. 14 shows a lamp unit 530 according to a third modification.

As shown in fig. 14, a rotating mirror (rotating reflector) 500 of a paddle scanning (registered trademark) system may be used instead of the polygon mirror 134 used in the above embodiment. The rotating mirror 500 includes a plurality of (3 in fig. 14) blades 501a and a cylindrical rotating portion 501 b. Each blade 501a is disposed around the rotation portion 501b and serves as a reflection surface. The rotating mirror 500 is arranged such that its rotation axis R is inclined with respect to the optical axis Ax.

The paddle 501a has a shape twisted so that an angle formed by the optical axis Ax and the reflecting surface changes with going to the circumferential direction around the rotation axis R. This enables scanning of light using the light source 32, as with the polygon mirror 134.

At least one blade 501a of the plurality of blades 501a has a shape different from the shape of the other blades 501 a. For example, at least one blade 501a of the plurality of blades 501a is shaped such that the laser light reflected by the blade 501a is more concentrated in the vertical direction than the diameter of the laser light when emitted from the light source 32. In contrast, the blade 501a different from the blade 501a is shaped such that the laser light reflected by the other blade 501a is more diffused in the vertical direction than the diameter of the laser light when emitted from the light source 32. When such a rotating mirror 500 is used, the vertical width of the line forming the light distribution pattern can be made different as in the above-described embodiment.

While the present invention has been described above with reference to the above embodiments, the present invention is not limited to the above embodiments, and configurations in which the components of the embodiments are appropriately combined or replaced are also included in the present invention. Further, the combination and the order of processing in the embodiments may be rearranged as appropriate based on the knowledge of those skilled in the art, or modifications such as various design changes may be added to the embodiments, and embodiments to which such modifications are added are also included in the scope of the present invention.

In the above-described embodiment, the lamp unit is described as a component mounted on the vehicle headlamp, but the present invention is not limited thereto. An optical unit including the light source and the rotating mirror described above may be used as a component of a sensor unit (e.g., laser radar, LiDAR, etc.) mounted on a vehicle. In this case, by making the curvatures of the respective reflection surfaces of the rotating mirror in the direction along the rotation axis different, it is also possible to finely control the scanning range and improve the sensor sensitivity.

Claims (11)

1. A light irradiation device is provided with: a light source; a mirror that is rotatable and reflects light emitted from the light source; and a main body that forms a light distribution pattern by linearly scanning the light divided into a plurality of light beams by shifting a reflection direction of the light beam by rotation of the mirror,

the light distribution pattern includes a first line and a second line,

the width of the first line is different from the width of the second line.

2. The light irradiation apparatus according to claim 1,

the mirror has at least: a first reflective surface for forming the first line; and a second reflecting surface arranged in a rotational direction of the mirror with respect to the first reflecting surface and forming the second line,

the curvature of the first reflective surface in a direction along a rotation axis of the mirror is different from the curvature of the second reflective surface in the direction along the rotation axis.

3. The light irradiation apparatus according to claim 2,

the first reflecting surface is formed of a surface curved convexly in the direction, and the second reflecting surface is formed of a surface curved concavely in the direction.

4. The light irradiation apparatus according to claim 2,

the first reflecting surface and the second reflecting surface are each formed by a surface curved convexly in the direction.

5. The light irradiation apparatus according to claim 2,

the first reflecting surface and the second reflecting surface are each formed of a surface that is concavely curved in the direction.

6. The light irradiation apparatus according to claim 2,

the first reflecting surface is formed of a surface curved convexly in the direction, and the second reflecting surface is formed of a flat surface in the direction.

7. The light irradiation apparatus according to claim 2,

the first reflecting surface is formed of a flat surface in the direction, and the second reflecting surface is formed of a surface concavely curved in the direction.

8. The light irradiation apparatus according to any one of claims 2 to 7,

the first reflective surface has a different inclination angle with respect to a rotation axis of the mirror than the second reflective surface.

9. The light irradiation apparatus according to claim 8, wherein

The second line is arranged between a plurality of the first lines,

the second line has a width narrower than a width of the plurality of first lines.

10. The light irradiation apparatus according to any one of claims 2 to 9,

further comprising an optical component for transmitting the light reflected by the mirror,

an incident diameter of the light incident to the optical member differs according to the curvatures of the first and second reflection surfaces.

11. The light irradiation apparatus according to any one of claims 1 to 10,

the mirror is configured as a polygonal mirror.

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