JP5352686B2 - Light projecting device, light projecting unit and light collecting member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a floodlight device capable of obtaining a projection pattern of a long shape. <P>SOLUTION: The floodlight device 1 is provided with semiconductor laser elements 11 to emit laser beams, a fluorescent member 22 which is excited by laser beams emitted from the semiconductor laser elements 11, and a reflecting member 23 which reflects the light emitted from the fluorescent member 22 and emits it to the outside. The fluorescent member 22 includes an irradiation region S on which the laser beams are irradiated, and a length Lc in a C direction of the irradiation region S is longer than that Ld in a D direction of the irradiation region S. <P>COPYRIGHT: (C)2013,JPO&amp;INPIT

Description

  The present invention relates to a light projecting device, a light projecting unit, and a condensing member, and in particular, a light projecting device including a fluorescent member that is irradiated with laser light, a light projecting unit, and a light condensing unit for irradiating the fluorescent member with the laser light It relates to members.

  2. Description of the Related Art Conventionally, a light projecting device including a fluorescent member that is irradiated with laser light is known (for example, see Patent Document 1).

  Patent Document 1 discloses an ultraviolet LD element that functions as a laser light source, a phosphor (fluorescent member) that converts laser light emitted from the ultraviolet LD element into visible light, and a visible light that reflects visible light emitted from the phosphor. A light source device (light projection device) including a light reflecting mirror is disclosed. In this light source device, a predetermined region in front of the light source device is illuminated by providing a visible light reflecting mirror that reflects visible light emitted from the phosphor.

JP 2003-295319 A

  By the way, when using the light source device of the said patent document 1 as a headlamp for motor vehicles, it is necessary to control the light projection pattern of the light radiate | emitted from a light source device. Specifically, it is necessary to configure the light source device so that the light projection pattern has a horizontally long shape. Although there is no description regarding a light projection pattern in the said patent document 1, it is guessed that a light projection pattern becomes circular shape. For this reason, there is a problem that it is difficult to use the light source device of Patent Document 1 as a headlight for an automobile that requires a horizontally long light projection pattern.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a light projecting device, a light projecting unit, and a light collecting member capable of obtaining a long light projecting pattern. Is to provide.

  In order to achieve the above object, a light projecting device of the present invention includes a fluorescent member excited by excitation light, a light projecting member that reflects or transmits light emitted from the fluorescent member, and emits the light to the outside. The fluorescent member includes an irradiation region irradiated with excitation light, and the length of the irradiation region in the first direction is larger than the length of the irradiation region in the second direction orthogonal to the first direction.

  In the light projecting device of the present invention, as described above, the length of the irradiation region in the first direction is larger than the length of the irradiation region in the second direction orthogonal to the first direction. Thereby, the fluorescent member is excited long in the first direction. For this reason, when the light emitted from the fluorescent member is emitted to the outside by the light projecting member, a long light projecting pattern that is long in the first direction can be obtained.

  In the present specification, the long shape means a shape in which the length in a predetermined direction is larger than the length in a direction orthogonal to the predetermined direction, and includes, for example, a concept including an elliptical shape, a rectangular shape, and an oval shape. There may be an asymmetric shape in the vertical and horizontal directions.

  Preferably, the light projecting device further includes a light condensing member including a light incident surface on which excitation light is incident and a light emitting surface having an area smaller than the light incident surface and emitting the excitation light. The length of the surface in the first direction is larger than the length of the light emitting surface in the second direction. Thus, by making the length of the first direction of the light emitting surface longer than the length of the second direction of the light emitting surface, the length of the irradiation region of the fluorescent member in the first direction is set to the second direction of the irradiation region. It can be easily made larger than the length. Further, by forming the light emitting surface of the light collecting member so as to have an area smaller than that of the light incident surface, the excitation light incident on the light incident surface is emitted from the light emitting surface in a condensed state.

  In the above light projecting device, the irradiation area is preferably rectangular, elliptical, or long hexagonal.

  In the light projecting device, preferably, the irradiation region has an asymmetric shape in the first direction. If comprised in this way, a light projection pattern can be easily made into an asymmetrical shape in a 1st direction.

  In the light projecting device, preferably, the focal point of the light projecting member is disposed at an edge of the irradiation region. If comprised in this way, in the part corresponding to the edge part of the irradiation area | region where the focus of a light projection member is arrange | positioned among light projection patterns, light and dark can be switched sharply.

  In the light projecting device in which the focal point of the light projecting member is disposed at the edge of the irradiation region, preferably, the light projecting device is used for a headlamp for an automobile, and the focus of the light projecting member is in the irradiation region. The projection pattern is arranged at the edge to project the cut-off line. This configuration is particularly effective because the brightness can be switched sharply in the cut-off line.

  In the present specification and claims, the cut-off line refers to a light / dark separation line of a low beam (passing headlight) projection pattern. In the cut-off line, it is required that the light and dark are switched sharply.

  In this case, preferably, the focal point of the light projecting member is arranged at a position where an elbow point of the light projection pattern in the irradiation area is projected. This configuration is more effective because the brightness can be switched sharply in the vicinity of the elbow point. In addition, the vicinity of the elbow point can be brightened. That is, the area directly in front of the automobile can be illuminated most brightly.

  In the present specification and claims, the elbow point refers to the intersection of the cut-off line on the left half and the right half of the projection pattern of the low beam (passing headlight).

  In the light projecting device, preferably, the length of the irradiation region in the first direction is three times or longer than the length of the irradiation region in the second direction. If comprised in this way, the ratio of the length of the 1st direction and the length of a 2nd direction of a light projection pattern can be about 3 times or more. For example, in an automobile headlamp, the aspect ratio of an appropriate projection pattern is about 1: 3 to 1: 4. Therefore, if the projector is used as an automobile headlamp, the front is appropriately illuminated. be able to.

  In the light projecting device including the light collecting member, the light exit surface is preferably formed in a rectangular shape, an elliptical shape, or a long hexagonal shape. If comprised in this way, the shape of the irradiation area | region of a fluorescent member can be prescribed | regulated easily.

  In the light projecting device including the light collecting member, preferably, the light exit surface has an asymmetric shape in the first direction. If comprised in this way, since an irradiation area | region can be easily made into an asymmetrical shape in a 1st direction, a light projection pattern can be easily made into an asymmetrical shape in a 1st direction.

  In the light projecting device in which the light emitting surface is asymmetric in the first direction, preferably, the light projecting device is used for a headlight for an automobile, and the light emitting surface is a light projecting pattern of a passing headlight. It is formed in the shape corresponding to. If comprised in this way, the light projection pattern required for the passing headlamp can be easily realized.

  In the light projecting device including the light collecting member, preferably, the length of the light emitting surface in the first direction is three times or more larger than the length of the light emitting surface in the second direction. If comprised in this way, the length of the 1st direction of an irradiation area | region can be made 3 times or more larger than the length of the 2nd direction of an irradiation area | region. Thereby, the ratio between the length in the first direction and the length in the second direction of the light projection pattern can be increased to about three times or more. For example, in an automobile headlamp, the aspect ratio of an appropriate projection pattern is about 1: 3 to 1: 4. Therefore, if the projector is used as an automobile headlamp, the front is appropriately illuminated. be able to.

  In the light projecting device, preferably, the light projecting member includes a reflecting member that reflects the light emitted from the fluorescent member and emits the light to the outside. If comprised in this way, the light radiate | emitted from the fluorescent member can be easily projected in a predetermined direction.

  In the light projecting device, preferably, the light projecting member includes a lens that transmits the light emitted from the fluorescent member and emits the light to the outside. If comprised in this way, the light radiate | emitted from the fluorescent member can be easily projected in a predetermined direction.

  In the light projecting device in which the light projecting member includes a lens, preferably, the light projecting member includes a reflective member having a reflective surface that reflects light emitted from the fluorescent member and a lens, and the reflective surface is formed of an elliptical surface. The first focal point of the reflecting surface is disposed in the irradiation area, and the second focal point of the reflecting surface coincides with the focal point of the lens. If comprised in this way, the light radiate | emitted from the irradiation area | region will be reflected by a reflective surface, will pass the 2nd focus of a reflective surface, and will be projected by a lens. At this time, since the second focal point of the reflecting surface coincides with the focal point of the lens, the light projection pattern formed by the lens easily reflects the shape of the irradiation region. In addition, when light is projected using a lens, the light projection pattern more easily reflects the shape of the irradiated region than when light is projected by a reflecting member without providing a lens. Further, by providing the reflecting member, more light emitted from the fluorescent member can be used as illumination light than when light is projected by a lens without providing the reflecting member. Thereby, the utilization efficiency of light can be improved.

  In the present specification and claims, the first focus refers to a focus closer to the top of the reflecting surface, and the second focus refers to the focus far from the top of the reflecting surface. say.

  In the light projecting device in which the light projecting member includes a reflective member, preferably, the reflective member includes a reflective surface that reflects light emitted from the fluorescent member, the reflective surface is formed by a parabolic surface, and the focal point of the reflective surface is irradiated. Arranged in the area. If comprised in this way, the light projection pattern formed with a reflective member will reflect the shape of an irradiation area | region easily.

  In the light projecting device, preferably, the light projecting member includes a lens that transmits the light emitted from the fluorescent member and emits the light to the outside, and the focal point of the lens is disposed in the irradiation region. If comprised in this way, the light projection pattern formed with a lens will reflect the shape of an irradiation area | region easily. Note that when light is projected using a lens, the light projection pattern more easily reflects the shape of the irradiated region than when light is projected by a reflecting member without providing a lens.

  In the light projecting device including the light collecting member, preferably, the light emitting surface is a rough surface or a moth-eye shape. If comprised in this way, reflection in the inner side of a light-projection surface will be suppressed, and light can be efficiently taken out outside.

  In the above projector, the excitation light preferably includes laser light.

  The light projecting unit according to the present invention includes a light incident surface on which excitation light is incident, a light condensing member having an area smaller than the light incident surface and emitting the excitation light, and a light exiting from the light condensing member A fluorescent member that is irradiated with the excitation light, and a reflective member that includes a reflective surface that reflects the light emitted from the fluorescent member toward a predetermined direction, and the fluorescent member includes an irradiation region that is irradiated with the excitation light. The focal point of the reflecting surface is arranged in the irradiation region, and the length from the focal point of the reflecting surface to the end of the irradiation region in the third direction is the length of the irradiation region in the fourth direction orthogonal to the third direction. Less than half of

  In the light projecting unit of the present invention, as described above, the length from the focal point of the reflecting surface to the end of the irradiation region in the third direction is half of the length of the irradiation region in the fourth direction orthogonal to the third direction. Smaller than. Thereby, the distance from the edge part of the 3rd direction of an irradiation area | region to the focus of a reflective surface becomes smaller than the distance from the edge part of the 4th direction of an irradiation area | region to the focus of a reflection surface. For this reason, it is possible to make the length of the 3rd direction of a light projection pattern smaller than the length of the 4th direction of a light projection pattern. That is, a long light projecting pattern that is long in the fourth direction can be obtained.

  In addition, as described above, the light emitting surface of the light collecting member is formed to have a smaller area than the light incident surface, so that the excitation light incident on the light incident surface is condensed in the light emitting surface. It is emitted from. Further, by providing the reflecting member, the light emitted from the fluorescent member can be easily projected in a predetermined direction.

  The condensing member of the present invention is a condensing member for condensing excitation light and irradiating the fluorescent member, and has a light incident surface on which excitation light is incident and an area smaller than the light incident surface. A light emitting surface that emits excitation light, and the length of the light emitting surface in the first direction is greater than the length of the light emitting surface in the second direction orthogonal to the first direction.

  In the condensing member of the present invention, as described above, the length of the light emitting surface in the first direction is set to be larger than the length of the light emitting surface in the second direction, so that the irradiation direction of the fluorescent member in the first direction is increased. The length can be made larger than the length of the irradiation region in the second direction. Thereby, the fluorescent member is excited long in the first direction. For this reason, it is possible to obtain a long light projection pattern that is long in the first direction. Further, by forming the light emitting surface of the light collecting member so as to have an area smaller than that of the light incident surface, the excitation light incident on the light incident surface is emitted from the light emitting surface in a condensed state.

  The light projecting unit of the present invention includes the light collecting member having the above-described configuration and a fluorescent member to which the excitation light emitted from the light collecting member is irradiated.

  As described above, according to the present invention, it is possible to easily obtain a light projecting device, a light projecting unit, and a light collecting member capable of obtaining a long light projecting pattern.

It is sectional drawing which showed the structure of the light projection apparatus provided with the light projection unit of 1st Embodiment of this invention. It is the perspective view which showed the structure of the light projector of 1st Embodiment of this invention. It is the perspective view which showed the structure of the laser generator of 1st Embodiment of this invention. It is the perspective view which showed the structure of the semiconductor laser element and heat spreader of 1st Embodiment of this invention. It is the perspective view which showed the structure of the semiconductor laser element of 1st Embodiment of this invention. It is the perspective view which showed the state which attached the condensing member to the laser generator of 1st Embodiment of this invention. It is a figure for demonstrating the laser beam radiate | emitted from the semiconductor laser element of 1st Embodiment of this invention. It is a perspective view for demonstrating the structure of the condensing member of 1st Embodiment of this invention. It is the top view which showed the structure of the condensing member of 1st Embodiment of this invention. It is the side view which showed the structure of the condensing member of 1st Embodiment of this invention. It is a side view for demonstrating advancing of the laser beam which injected into the condensing member of 1st Embodiment of this invention. It is a top view for demonstrating advancing of the laser beam which injected into the condensing member of 1st Embodiment of this invention. It is the top view which showed the modification of the arrangement direction of the semiconductor laser element of 1st Embodiment of this invention. It is the top view which showed the modification of the condensing member of 1st Embodiment of this invention. It is the perspective view which showed the modification of the condensing member of 1st Embodiment of this invention. It is the front view which showed the light-projection surface of the condensing member of FIG. It is the perspective view which showed the modification of the condensing member of 1st Embodiment of this invention. It is a figure for demonstrating the light intensity distribution of the laser beam in the light-projection surface of the condensing member of 1st Embodiment of this invention. It is the figure which showed the structure of the fluorescent member periphery of 1st Embodiment of this invention. It is the perspective view which showed the state which irradiated the laser beam only to the center part of the fluorescent member of 1st Embodiment of this invention. It is a figure for demonstrating the irradiation area | region of the fluorescent member of 1st Embodiment of this invention. It is sectional drawing for demonstrating the structure of the reflection member of 1st Embodiment of this invention. It is a front view for demonstrating the structure of the reflection member of 1st Embodiment of this invention. It is a figure for demonstrating the light projection pattern obtained by the light projection apparatus of 1st Embodiment of this invention. It is sectional drawing which showed the structure of the light projector of 2nd Embodiment of this invention. It is the perspective view which showed the structure of the condensing member of 3rd Embodiment of this invention. It is a figure for demonstrating the irradiation area | region of the fluorescent member of 3rd Embodiment of this invention. It is the figure which showed light intensity distribution of the laser beam on the fluorescent member of 3rd Embodiment of this invention. It is the figure which showed the light intensity distribution of the fluorescence in front of 25m of the light projector of 3rd Embodiment of this invention. It is sectional drawing which showed the structure of the light projector of 4th Embodiment of this invention. It is the perspective view which showed the structure of the condensing member of 4th Embodiment of this invention. It is a figure for demonstrating the irradiation area | region of the fluorescent member of 4th Embodiment of this invention. It is a figure for demonstrating the light projection pattern obtained by the light projection apparatus of 4th Embodiment of this invention. It is sectional drawing which showed the structure of the light projector of 5th Embodiment of this invention. It is the perspective view which showed the structure of the condensing member of 5th Embodiment of this invention. It is a figure for demonstrating the irradiation area | region of the fluorescent member of 5th Embodiment of this invention. It is a figure for demonstrating the light projection pattern in 25m front of the light projection apparatus of 5th Embodiment of this invention. It is a figure for demonstrating the light projection pattern requested | required of the low beam of a motor vehicle. It is sectional drawing which showed the structure of the light projector of 6th Embodiment of this invention. It is the perspective view which showed the structure of the condensing member of 6th Embodiment of this invention. It is sectional drawing which showed the structure of the light projection apparatus of 7th Embodiment of this invention. It is the perspective view which showed the structure of the condensing member of the 1st modification of this invention. It is the figure which showed the lens periphery of the light projection apparatus of the 2nd modification of this invention. It is sectional drawing which showed the structure of the light projection apparatus of the 3rd modification of this invention. It is sectional drawing which showed the structure of the light projection apparatus of the 4th modification of this invention. It is sectional drawing which showed the structure of the light projection apparatus of the 5th modification of this invention.

  Embodiments of the present invention will be described below with reference to the drawings. In order to facilitate understanding, hatching may be performed even in a cross-sectional view, or hatching may be performed even in a cross-sectional view.

(First embodiment)
First, with reference to FIGS. 1-23, the structure of the light projector 1 by 1st Embodiment of this invention is demonstrated. In order to simplify the drawing, the number of semiconductor laser elements 11 may be omitted.

  The floodlight device 1 according to the first embodiment of the present invention is used as a headlamp that illuminates the front of a car, for example. As shown in FIGS. 1 and 2, the light projecting device 1 has a laser generator 10 that functions as a laser light source (excitation light source) and a predetermined direction (A direction) using laser light emitted from the laser generator 10. And a light projecting unit 20 for projecting light. In FIG. 2, a mounting portion 24 b, a filter member 25, and a support plate 26 described later of the light projecting unit 20 are omitted for easy understanding.

  As shown in FIG. 3, the laser generator 10 includes a plurality of semiconductor laser elements 11 (laser generators), a heat spreader 12 on which the plurality of semiconductor laser elements 11 are mounted, and a metal storage member 13 that stores these. Is included.

  The heat spreader 12 is formed of, for example, a flat plate made of aluminum nitride, and is soldered to the bottom surface of the storage member 13. As shown in FIG. 4, the heat spreader 12 has, for example, a width (W12) of about 15 mm, a thickness (T12) of about 1 mm, and a depth (L12) of about 2 mm. On the mounting surface of the heat spreader 12, elongated electrode patterns 12a and 12b are formed. On the electrode pattern 12a, a plurality of semiconductor laser elements 11 are arranged in a straight line. In this embodiment, for example, 13 semiconductor laser elements 11 are mounted and arranged over a width (W12a) of about 10 mm. The width (W12a) is preferably smaller than the width (W21a) (see FIG. 9) of a light incident surface 21a of a light collecting member 21 described later of the light projecting unit 20.

  The semiconductor laser element 11 is, for example, a broad area laser, and emits laser light that functions as excitation light. The semiconductor laser element 11 is configured to emit blue-violet laser light having a center wavelength of about 405 nm, for example. As shown in FIG. 5, the semiconductor laser element 11 has, for example, a width (W11) of about 200 μm, a thickness (T11) of about 100 μm, and a length (L11) of about 1000 μm.

In addition, the semiconductor laser device 11 includes a substrate 11a made of n-type GaN having a thickness of about 100 μm, a buffer layer 11b made of n-type GaN having a thickness of about 0.5 μm formed on the substrate 11a, and a layer thickness of about 2 μm. A lower cladding layer 11c made of n-type Al _0.05 Ga _0.95 N, an active layer 11d made of multiple quantum wells of InGaN, and a p-type Al _{0.05 having} a layer thickness of about 0.5 μm (thickest part). And an upper clad layer 11e made of Ga _0.95 N.

A ridge extending in the Z direction (the length direction of the semiconductor laser element 11) is provided at a predetermined position of the upper cladding layer 11e. On this ridge, a contact layer 11f made of p-type GaN having a layer thickness of about 0.1 μm and an electrode 11g made of Pd are formed. Further, the upper surface of the upper clad layer 11e, an insulating film 11h made of SiO ₂ so as to cover the side surface of the contact layer 11f and an electrode 11g is formed. A pad electrode 11i that covers the ridge and is in ohmic contact with the electrode 11g is formed in a predetermined region on the insulating film 11h. A back electrode 11j made of Hf / Al is formed on the lower surface of the substrate 11a.

  As shown in FIG. 4, the pad electrode 11 i of each semiconductor laser element 11 is electrically connected to the electrode pattern 12 b of the heat spreader 12 via the Au wire 14. Further, the back electrode 11j (see FIG. 5) of each semiconductor laser element 11 is electrically connected to the electrode pattern 12a through a solder layer (not shown). The width of the light emitting portion 11k (see FIG. 7) of the semiconductor laser element 11 defines the ridge width (W11a in FIG. 5) of the upper cladding layer 11e, and this ridge width is set to 7 μm, for example. In this case, the width of the light emitting portion 11k is about 7 μm.

  Further, as shown in FIG. 3, the storage member 13 is formed in a box shape having an opening on the laser beam emission side. Further, electrode pins 15 a and 15 b for supplying electric power to the semiconductor laser element 11 are inserted into the storage member 13. The electrode pins 15 a and 15 b are electrically connected to the electrode patterns 12 a and 12 b of the heat spreader 12 using metal wires 16, respectively. A glass plate (not shown) is attached to the opening of the storage member 13, and an inert gas is sealed inside the storage member 13. The storage member 13 may be provided with heat radiating fins (not shown), and the storage member 13 may be air-cooled, for example. In addition, as shown in FIG. 6, the condensing member 21 mentioned later of the light projection unit 20 is being fixed to the predetermined position of the glass plate through the transparent contact bonding layer. Thereby, the laser light emitted from the plurality of semiconductor laser elements 11 enters the light collecting member 21.

  When a direct current is applied between the pad electrode 11i and the back electrode 11j of the semiconductor laser element 11, as shown in FIG. 7, the X direction (width direction of the semiconductor laser element 11) and the Y direction (semiconductor laser element 11). The laser light that spreads in an elliptical shape in the thickness direction) is emitted from the light emitting portion 11k. The light intensity distribution of the elliptical light projected on the XY plane perpendicular to the traveling direction (Z direction) of the laser light is a Gaussian distribution in both the X direction and the Y direction. The full width at half maximum (θx) of the light intensity distribution in the X direction is about 10 °, the full width at half maximum (θy) of the light intensity distribution in the Y direction is about 20 °, and the spread angle of the laser light is larger in the Y direction than in the X direction. About twice as large. As a result, the laser light travels while spreading with the X direction as the minor axis direction and the Y direction as the major axis direction.

  When about 57 W is supplied to the laser generator 10, the output of the laser generator 10 is about 9.4W. At this time, the illuminance at the maximum illuminance point 25 m ahead of the light projecting device 1 is about 120 lux (lx), and the light beam emitted to the outside via the reflecting member 23 described later is about 530 lumens (lm).

  As shown in FIG. 1, the light projecting unit 20 is disposed on the laser beam emitting side of the laser generator 10 (semiconductor laser element 11), and condenses the light while condensing the laser beam from the laser generator 10. 21, a fluorescent member 22 that converts at least a part of the laser light emitted from the light collecting member 21 into fluorescence, and a reflection that reflects the fluorescence emitted from the fluorescent member 22 in a predetermined direction (A direction). A member 23 (light projecting member), a mounting member 24 to which the fluorescent member 22 is fixed, and a filter member 25 provided in the opening of the reflecting member 23 are included.

  The condensing member 21 is formed of a member having translucency. Examples of the material of the light collecting member 21 include glass such as borosilicate crown optical glass (BK7) or synthetic quartz, and resin. As shown in FIG. 8, the condensing member 21 includes a light incident surface 21a on which laser light emitted from the plurality of semiconductor laser elements 11 is incident, a light emitting surface 21b that emits laser light, and a light incident surface 21a. And an upper surface 21c, a lower surface 21d, and a pair of side surfaces 21e disposed between the light emitting surfaces 21b.

  The light incident surface 21a is formed by a substantially rectangular flat surface, for example. The light emitting surface 21b is formed by a substantially rectangular flat surface, for example, and has an area smaller than that of the light incident surface 21a. That is, the condensing member 21 is formed in a tapered shape with respect to the width direction (C direction) and the thickness direction (D direction). Specifically, as shown in FIGS. 9 and 10, the light incident surface 21a has a height (H21a) of about 0.96 mm and a width (W21a) of about 10.51 mm. The light exit surface 21b has a height (H21b) of about 0.34 mm and a width (W21b) of about 1.19 mm. That is, the length (= W21b) in the C direction (first direction) of the light emitting surface 21b is three times or more than the length (= H21b) in the D direction (second direction) of the light emitting surface 21b (here, H21b). About 3.5 times larger. An antireflection (AR) film (not shown) may be formed on the light incident surface 21a and the light emitting surface 21b. In the first embodiment, when the light emitting surface 21b of the light collecting member 21 and the irradiation region of the fluorescent member 22 are rectangular, the direction in which the long side extends is the “first direction” of the present invention. That is, the direction in which the longest side forming the light emitting surface 21b and the irradiation region extends is the “first direction” of the present invention. In other words, it can be said that the “first direction” of the present invention is a horizontal direction orthogonal to the light projecting direction (direction A). In addition, it can be said that the “second direction” of the present invention is a direction orthogonal to the “first direction” and parallel to the surface of the fluorescent member.

  Further, the light emitting surface 21b may be a ground glass-like rough surface or a so-called moth-eye shape. In this case, the extraction efficiency when extracting the laser beam from the inside of the light collecting member 21 to the outside through the light emitting surface 21b can be greatly improved. When the light emitting surface 21b is a flat surface, when the laser light reaches the light emitting surface 21b inside the light condensing member 21, the laser light is reflected inside the light emitting surface 21b and cannot be extracted outside. Ingredients are produced. On the other hand, by making the light emitting surface 21b a ground glass-like rough surface or a so-called moth-eye shape, reflection inside the light emitting surface 21b is suppressed, and light can be efficiently extracted outside.

  The upper surface 21c and the lower surface 21d are formed in the same shape, and the pair of side surfaces 21e are formed in the same shape. The upper surface 21c, the lower surface 21d, and the pair of side surfaces 21e have a length (L21) of about 50 mm.

  Also, the angles (θ21c and θ21d) of the upper surface 21c and the lower surface 21d with respect to the light incident surface 21a are larger than the angles (θ21e) of the side surface 21e with respect to the light incident surface 21a.

  The upper surface 21c, the lower surface 21d, and the pair of side surfaces 21e have a function of reflecting the laser light incident on the light incident surface 21a and guiding it to the light emitting surface 21b.

  Here, the progression of the laser light incident on the light collecting member 21 will be briefly described. As shown in FIGS. 11 and 12, the laser light emitted from the semiconductor laser element 11 travels while spreading in the major axis direction and the minor axis direction, and enters the light incident surface 21 a of the light collecting member 21. The laser light is repeatedly totally reflected by the upper surface 21c, the lower surface 21d, and the pair of side surfaces 21e, so that the laser beam is guided to the light emitting surface 21b while being condensed, and is emitted to the outside from the light emitting surface 21b. That is, the condensing member 21 has a function of guiding the laser light to the light emitting surface 21b by changing the traveling direction of the laser light incident on the light incident surface 21a inside the condensing member 21. Since the laser beam emitted from the semiconductor laser element 11 has a larger spread angle in the major axis direction than that in the minor axis direction, it is difficult to satisfy the total reflection condition on the upper surface 21c and the lower surface 21d. Therefore, by making the angles (θ21c and θ21d) (see FIG. 10) of the upper surface 21c and the lower surface 21d with respect to the light incident surface 21a larger than the angles (θ21e) with respect to the light incident surface 21a of the side surface 21e (see FIG. 9). The upper surface 21c and the lower surface 21d are prevented from satisfying the total reflection condition.

  In addition, as shown in FIG. 13, if the semiconductor laser element 11 is arranged so that the laser beam emission direction (laser beam optical axis direction) faces the vicinity of the center of the light emission surface 21 b of the light collecting member 21, The side surface 21e is particularly effective because it easily satisfies the total reflection condition. In the case where the semiconductor laser element 11 is arranged so that the laser beam emission direction is directed to the vicinity of the center of the light emission surface 21b, the emission direction of each laser beam and the light incident surface 21a are orthogonal to each other as shown in FIG. In this manner, the light incident surface 21a may be formed. Thereby, it is possible to suppress a decrease in the incidence efficiency of the laser light on the light collecting member 21. The condensing member 21 is not limited to guiding light by using total reflection, but may simply guide light by using reflection.

  Moreover, you may chamfer the edge of the condensing member 21, as shown in FIGS. That is, the cross section perpendicular to the light guide direction of the light collecting member 21 may be rectangular with the corners chamfered. In this case, as shown in FIGS. 15 and 16, the edge (corner portion in the cross section) of the light collecting member 21 may be chamfered. Moreover, as shown in FIG. 17, you may chamfer the edge of the condensing member 21. As shown in FIG. In addition, the light guide direction of the condensing member 21 is a direction from the center of the light incident surface 21a toward the center of the light emitting surface 21b. If the cross section perpendicular to the light guide direction of the light condensing member 21 is formed in a rectangular shape with chamfered corner portions, it is possible to suppress scattering of laser light at the edge of the light condensing member 21 (corner portion of the cross section). is there. Thereby, since it is possible to suppress the leakage of the laser light from the light collecting member 21, it is possible to improve the utilization efficiency of the laser light.

  As shown in FIG. 18, the light intensity distribution of the laser beam on the light exit surface 21b of the light collecting member 21 of the present embodiment is uniform. That is, the light intensity distribution of the laser light emitted from the light emitting surface 21b is not a Gaussian distribution. For this reason, it is possible to suppress the occurrence of a portion where the light density is excessively high on the irradiation surface 22a described later of the fluorescent member 22. Thereby, it is possible to suppress the phosphor and the binder contained in the fluorescent member 22 from being deteriorated by heat, or from causing a chemical reaction by light and being deteriorated.

  Moreover, as shown in FIG. 19, the condensing member 21 is inclined in the B direction (the side opposite to the light projecting direction (predetermined direction, A direction)). Further, a gap (space) is formed between the light emitting surface 21 b of the light collecting member 21 and the irradiation surface 22 a of the fluorescent member 22. Note that the light projecting direction is a direction toward the most illuminating portion, for example, 25 m ahead of the light projecting device 1, and is, for example, a direction from the center of the opening of the reflecting surface 23a toward the maximum illuminance point 25 m ahead.

  The fluorescent member 22 has an irradiation surface 22a on which laser light is irradiated. The back surface of the fluorescent member 22 (surface opposite to the irradiation surface 22a) is in contact with a support plate 26 made of aluminum. The fluorescent member 22 is formed by being deposited on the support plate 26 by electrophoresis, for example. The support plate 26 has a width of about 10 mm, a length of about 10 mm, and a thickness of about 1 mm. The fluorescent member 22 has a width of about 10 mm, a length of about 10 mm, and a uniform thickness of about 0.1 mm. As shown in FIG. 20, the laser beam condensed through the condensing member 21 is irradiated to the central portion of the irradiation surface 22 a of the fluorescent member 22. Since the length of the light exit surface 21b of the light collecting member 21 in the C direction is three times or more (about 3.5 times here) longer than the length of the light exit surface 21b in the D direction, as shown in FIG. The length (Lc) in the C direction of the irradiation region S irradiated with the laser beam at the central portion of 22a is at least three times (here, about 3.5 times) the length (Ld) in the D direction of the irradiation region S. )growing. That is, the fluorescent member 22 is excited in a substantially rectangular shape that is long in the C direction. In other words, the fluorescent member 22 is excited with a distribution extending in a direction (C direction) orthogonal to the light projecting direction (A direction) with a focus F23 (described later) on the reflecting surface 23a as the center. Then, fluorescence is emitted from a substantially rectangular area. The entire surface of the irradiation surface 22a of the fluorescent member 22 may be irradiated with the fluorescent member 22 having an area corresponding to the area irradiated with the laser light.

The fluorescent member 22 is formed using, for example, three types of phosphor particles that convert blue-violet light (excitation light) into red light, green light, and blue light, respectively, and emit. Examples of the phosphor that converts blue-violet light into red light include CaAlSiN ₃ : Eu. Examples of the phosphor that converts blue-violet light into green light include β-SiAlON: Eu. Examples of the phosphor that converts blue-violet light into blue light include (Ba, Sr) MgAl ₁₀ O ₁₇ : Eu. These phosphors are held together by an inorganic binder (such as silica or TiO ₂ ). The red light, green light, and blue light emitted from the fluorescent member 22 are mixed to obtain white light. Note that red light is light having a center wavelength of about 640 nm, for example, and green light is light having a center wavelength of about 520 nm, for example. Blue light is light having a center wavelength of about 450 nm, for example.

  Further, as shown in FIG. 1, the fluorescent member 22 is disposed in a region including the focal point F23 of the reflecting surface 23a of the reflecting member 23, and the center of the irradiation surface 22a of the fluorescent member 22 is the same as the focal point F23 of the reflecting surface 23a. It is almost coincident. The fluorescent member 22 may be disposed in the vicinity of the focal point F23 of the reflecting surface 23a of the reflecting member 23. Moreover, as shown in FIG. 19, the irradiation surface 22a of the fluorescent member 22 is inclined upward in the light projecting direction (A direction).

  As shown in FIG. 22, the reflecting surface 23 a of the reflecting member 23 is disposed so as to face the irradiation surface 22 a of the fluorescent member 22. Moreover, the reflective surface 23a is formed so that a part of paraboloid may be included, for example. Specifically, the reflecting surface 23a is a surface that divides the paraboloid by a plane orthogonal to (intersects) the axis connecting the vertex V23 and the focal point F23, and parallel to the axis connecting the vertex V23 and the focal point F23. It is formed in the shape divided by. As shown in FIGS. 22 and 23, the reflecting surface 23a has a depth of about 30 mm (length in the B direction) and a substantially half radius having a radius of about 30 mm when viewed from the light projecting direction (A direction). It is formed in a circular shape.

  The reflecting surface 23a has a function of reflecting light from the fluorescent member 22 in a predetermined direction (A direction). In addition, the light emitted from the focal point F23 of the reflecting surface 23a of the fluorescent member 22 is converted into parallel light by the reflecting surface 23a, but the light emitted from a position deviated from the focal point F23 in the C direction, for example, is C by the reflecting surface 23a. It is emitted in a state of spreading in the direction. Further, a through hole 23b is formed in a portion of the reflecting member 23 in the B direction from the center of the fluorescent member 22. The tip end portion of the light collecting member 21 is inserted into the through hole 23b.

  The reflecting member 23 may be made of metal or may be formed by providing a reflecting film on the surface of the resin.

  An attachment member 24 is fixed to the reflection member 23. The upper surface 24a of the mounting member 24 is preferably formed so as to have a function of reflecting light. The attachment member 24 is formed of a metal having good thermal conductivity such as Al or Cu, and has a function of radiating heat generated in the fluorescent member 22. An attachment portion 24 b for fixing the fluorescent member 22 and the support plate 26 is integrally formed on the upper surface 24 a of the attachment member 24. As shown in FIG. 19, the mounting surface 24c of the mounting portion 24b is inclined upward in the light projecting direction (A direction). In addition, it is preferable that a heat radiating fin (not shown) is provided on the lower surface of the mounting member 24.

  Further, as shown in FIG. 1, excitation light (light having a wavelength of about 405 nm) is shielded (absorbed or reflected) at the opening (end in the A direction) of the reflecting member 23, and wavelength conversion is performed by the fluorescent member 22. A filter member 25 that transmits the fluorescent light (red light, green light, and blue light) is provided. Specifically, the filter member 25 absorbs light having a wavelength of about 418 nm or less and transmits light having a wavelength greater than about 418 nm, for example, TY-418 manufactured by Isuzu Seiko Glass Co., Ltd., for example, about 420 nm or less. Can be formed using a glass material such as L42 manufactured by HOYA Co., Ltd., which absorbs light having a wavelength of .about.420 nm and transmits light having a wavelength greater than about 420 nm. By providing the filter member 25 at the opening of the reflecting member 23, it is possible to suppress the leakage of laser light to the outside.

  Next, a light projection pattern of light emitted from the light projecting device 1 will be described with reference to FIG. In FIG. 24, assuming that the virtual screen is arranged at a position 25 m ahead of the light projecting device 1, the light projection pattern P projected on the virtual screen will be described. The fluorescent light projection pattern P projected by the reflecting member 23 has an elliptical shape in which the length (Lpc) in the horizontal direction (C direction) is 3 to 4 times larger than the length (Lpd) in the vertical direction (D direction). Became. That is, the light projection pattern P can be formed in a horizontally long shape. This horizontally long light projecting pattern P has a shape necessary for efficiently illuminating the center of the road and the left and right sidewalks and road signs when the light projecting device 1 is used as a headlight of an automobile. . When the length in the C direction and the length in the D direction of the light emitting surface 21b of the light collecting member 21 are the same, the projection pattern P has a circular shape in which the horizontal length and the vertical length are the same. Become.

  In the present embodiment, as described above, the length Lc in the C direction of the irradiation region S is larger than the length Ld in the D direction of the irradiation region S. Thereby, the fluorescent member 22 is excited long in the C direction. For this reason, when the light emitted from the fluorescent member 22 is emitted to the outside by the reflecting member 23, a long (elliptical) projection pattern P that is long in the C direction can be obtained.

  Further, as described above, the length in the C direction (width W21b) of the light emitting surface 21b of the light collecting member 21 is made larger than the length in the D direction (height H21b) of the light emitting surface 21b. The length Lc in the C direction of the irradiation region S of the member 22 can be easily made larger than the length Ld in the D direction of the irradiation region S. Further, by forming the light emitting surface 21b of the condensing member 21 so as to have an area smaller than that of the light incident surface 21a, the laser light incident on the light incident surface 21a is condensed in the light emitting surface 21b. It is emitted from. For this reason, the density of the laser light emitted from the light collecting member 21 can be increased.

  Further, as described above, the length in the C direction (width W21b) of the light emitting surface 21b is three times or more larger than the length in the D direction (height H21b) of the light emitting surface 21b. Thereby, the length Lc in the C direction of the irradiation region S can be made three times or more larger than the length Ld in the D direction of the irradiation region S. Thereby, the ratio of the length (Lpc) in the C direction and the length (Lpd) in the D direction of the projection pattern P can be increased to about three times or more. For example, in an automotive headlamp, the appropriate aspect ratio of the projection pattern P is about 1: 3 to 1: 4. Therefore, if the projector 1 is used as an automotive headlamp, the front side is appropriately Can be illuminated.

  In the present application, in a system for projecting light obtained by exciting a fluorescent member with a laser beam, it is possible to project horizontally long light by exciting the fluorescent member in a horizontally long shape (long shape in a predetermined direction). Is a feature, and there is a further feature in that it has been proposed to use a light guide member (light condensing member) having a horizontally long light exit surface in order to suitably implement it.

  Further, as described above, by providing the reflecting member 23, the light emitted from the fluorescent member 22 can be easily projected in a predetermined direction.

  Further, as described above, if the light emitting surface 21b is formed into a rough surface or a moth-eye shape, reflection inside the light emitting surface 21b is suppressed, and light can be efficiently extracted to the outside.

(Second Embodiment)
In the second embodiment, referring to FIG. 25, unlike the first embodiment, the fluorescence emitted from the back surface (surface opposite to the irradiation surface 22a) of the fluorescent member 22 is reflected by the reflecting member 23. Will be described.

  In the light projecting device 101 according to the second embodiment of the present invention, as shown in FIG. 25, the light projecting unit 120 includes a light collecting member 21, a fluorescent member 22, a reflecting member 23, and a sub-reflecting member 127. Yes.

  The fluorescent member 22 has a thickness of about 0.1 mm to 1 mm, and the irradiation surface 22 a and the back surface of the fluorescent member 22 are formed to have the same size as the light emitting surface 21 b of the light collecting member 21. The fluorescent member 22 is fixed on the light emitting surface 21 b of the light collecting member 21. For this reason, the fluorescent member 22 is excited in a rectangular shape that is long in the C direction (direction perpendicular to the paper surface in FIG. 25), as in the first embodiment. Note that the length in the C direction of the irradiation region (the entire irradiation surface 22a) of the fluorescent member 22 is three times or more (about 3.5 times here) longer than the length of the irradiation region in the D direction. Then, fluorescence is emitted from the rectangular region.

  Further, the fluorescent member 22 of the present embodiment has a lower density of phosphor particles than the fluorescent member 22 of the first embodiment, and when irradiated with laser light, the fluorescent member 22 is fluorescent from the back surface (the surface opposite to the irradiated surface 22a). Is emitted. Note that the fluorescence may be emitted from the side surface of the fluorescent member 22 (the surface connecting the irradiation surface 22a and the back surface).

  The reflecting surface 23a of the reflecting member 23 is formed in a shape such that the paraboloid is divided by a plane orthogonal to (intersecting) the axis connecting the apex and the focal point. The reflection surface 23a has a depth of about 15 mm (length in the B direction) and is formed in a circular shape having a radius of about 15 mm when viewed from the light projecting direction (A direction).

  In the light projecting device 101, as in the light projecting device 1 of the first embodiment, the fluorescent light projecting pattern P projected by the reflecting member 23 has a horizontal (C direction) length in the vertical direction (D It becomes an elliptical shape 3 to 4 times larger than the length of (direction).

  The sub-reflecting member 127 is disposed in front of the fluorescent member 22. The sub-reflecting member 127 is formed in a shape using a part of a spherical surface, and is formed in a circular shape having a diameter of about 5 mm when viewed from the light projecting direction (A direction). The sub-reflecting member 127 has a function of reflecting the fluorescent light that does not hit the reflecting member 23 and the laser beam that has passed through the fluorescent member 22 to be emitted to the fluorescent member 22 after being reflected. The light that has entered the fluorescent member 22 again is scattered by the fluorescent member 22 or converted into fluorescent light, and is emitted from the fluorescent member 22 again. At this time, light is emitted from the rectangular region.

  The remaining structure and effects of the second embodiment are similar to those of the aforementioned first embodiment.

(Third embodiment)
In the third embodiment, with reference to FIGS. 26 to 29, unlike the first and second embodiments, a case where the light exit surface 21b of the light collecting member 21 is formed in a long hexagonal shape will be described. .

  In the light collecting member 21 of the present embodiment, as shown in FIG. 26, the light incident surface 21a and the light emitting surface 21b are formed in a long hexagonal shape. Specifically, the light incident surface 21a has a height (H21a) of about 3 mm and a width (W21a) of about 15 mm. The light exit surface 21b has a height (H21b) of about 2 mm and a width (W21b) of about 6 mm. Moreover, the edge part by the side of the light-projection surface 21b of the upper surface 21c and the lower surface 21d has a width | variety (W21c) of about 2 mm.

  Accordingly, when the fluorescent member 22 is irradiated with laser light, the irradiation region S of the fluorescent member 22 is as shown in FIG. 27, and the length (Lc) in the C direction of the irradiation region S is the D direction of the irradiation region S. 3 times or more (about 3 times here) than the length (Ld). The light intensity distribution of the laser light on the fluorescent member 22 in the C direction is as shown in FIG.

  When the light collecting member 21 of the present embodiment is used, the light intensity distribution of the fluorescence 25 m ahead of the light projecting device is as shown by the solid line in FIG. The broken line in FIG. 29 shows the fluorescence light intensity distribution when the light emitting surface 21b of the light collecting member 21 is formed in a rectangular shape having a height of about 2 mm and a width of about 6 mm. Compared to the case where the light exit surface 21b has a long hexagonal shape (in the case of a solid line in FIG. 29) and the light exit surface 21b has a rectangular shape (in the case of a broken line in FIG. 29), a 2m area R1 (road) It is possible to increase the light intensity in the central area) and decrease the light intensity in the peripheral area R2 (areas such as sidewalks, roadside trees, and road signs). That is, by making the light emission surface 21b into a long hexagonal shape, the light projection pattern can be expanded in the horizontal direction (C direction), and a large amount of light is prevented from being distributed to the peripheral region R2. Is possible.

  In the third embodiment, the direction in which the longest line extending across the light emitting surface 21b or the irradiation region extends is the “first direction” of the present invention. In other words, the “first direction” of the present invention is a horizontal direction that is orthogonal to the light projecting direction (A direction). In addition, it can be said that the “second direction” of the present invention is a direction orthogonal to the “first direction” and parallel to the surface of the fluorescent member.

  Other structures and effects of the third embodiment are the same as those of the first and second embodiments.

(Fourth embodiment)
Next, the structure of the light projecting device 201 according to the fourth embodiment of the present invention will be described with reference to FIGS.

  In the light projecting device 201 according to the fourth embodiment of the present invention, as shown in FIG. 30, the light projecting unit 220 includes a light collecting member 21, a fluorescent member 22, a reflecting member 23, and a substrate 228 that supports the fluorescent member 22. Including.

  In the condensing member 21 of this embodiment, as shown in FIG. 31, the light incident surface 21a is formed in a rectangular shape, and the light emitting surface 21b is formed in an inverted trapezoidal shape. Specifically, the light incident surface 21a has a height (H21a) of about 3 mm and a width (W21a) of about 10 mm. The light exit surface 21b has a height (H21b) of about 3 mm and a width (W21b) of about 3 mm. The end of the upper surface 21c on the light emitting surface 21b side has a width (W21c) of about 3 mm, and the end of the lower surface 21d on the light emitting surface 21b side has a width of about 1 mm (W21d).

  As shown in FIG. 30, the fluorescent member 22 is disposed at a position of about 1.9 mm from the apex of the reflecting surface 23a of the reflecting member 23, and has a diameter of about 7.5 mm. The outer peripheral surface of the fluorescent member 22 is in contact with the reflecting surface 23 a of the reflecting member 23. As shown in FIG. 32, the fluorescent member 22 is disposed in a region including the focal point F23 of the reflecting surface 23a of the reflecting member 23, and the center of the irradiation surface 22a of the fluorescent member 22 is substantially the same as the focal point F23 of the reflecting surface 23a. I'm doing it. The fluorescent member 22 is provided on the substrate 228. For example, the fluorescent member 22 is formed by applying a resin containing phosphor particles on the substrate 228 and curing it.

  As shown in FIG. 30, the substrate 228 has a function of transmitting the fluorescence emitted from the fluorescent member 22 and is fixed to the reflective surface 23 a of the reflective member 23.

  The reflecting surface 23a of the reflecting member 23 is formed in a shape such that the paraboloid is divided by a plane orthogonal to (intersecting) the axis connecting the apex and the focal point. The reflection surface 23a has a depth of about 30 mm (length in the B direction) and is formed in a substantially circular shape having a radius of about 15 mm when viewed from the light projecting direction (A direction).

  In the present embodiment, when the fluorescent member 22 is irradiated with laser light, the irradiation region S of the fluorescent member 22 has an inverted trapezoidal shape as shown in FIG. Specifically, the irradiation region S has a height (Hs) of about 3 mm, the upper side of the irradiation region S has a width (Ws1) of about 3 mm, and the lower side of the irradiation region S has a width (Ws2) of about 1 mm. ).

  Further, the center of the irradiation region S is arranged at a position shifted from the focal point F23 of the reflecting surface 23a. Specifically, the length (Ls1) from the focal point F23 to the end of the irradiation region S in the D direction (third direction) is the length (Ls2 (= Ws1) in the C direction (fourth direction) of the irradiation region S. )) Less than half. That is, the irradiation region S is formed so as to expand in the left-right direction and the downward direction (the ground direction) with respect to the focal point F23.

  For this reason, the light projection pattern P 25 m ahead of the light projection device 201 is as shown in FIG. Specifically, the light projection pattern P does not expand in the upward direction, but extends in the left-right direction (horizontal direction) and the downward direction. In other words, it is possible to illuminate the periphery of the road while suppressing unnecessary illumination in the sky direction (upward direction). In addition, the light intensity of the area R1 (area at the center of the road) having a diameter of about 2 m in the front is high, and the light intensity of the peripheral area R2 (area such as sidewalks, roadside trees, and road signs) is low.

  The remaining structure of the fourth embodiment is similar to that of the aforementioned first to third embodiments.

  In the present embodiment, as described above, the length (Ls1) from the focal point F23 of the reflecting surface 23a to the end of the irradiation region S in the D direction is the length of the irradiation region S in the C direction orthogonal to the D direction ( Less than half of Ls2). Thereby, the distance from the edge part of the irradiation area S in the D direction to the focal point F23 of the reflecting surface 23a is smaller than the distance from the edge part of the irradiation area S in the C direction to the focal point F23 of the reflecting surface 23a. For this reason, it is possible to make the length (Lpd) of the projection pattern P in the D direction smaller than the length (Lpc) of the projection pattern P in the C direction. That is, a long (elliptical) projection pattern P that is long in the C direction can be obtained.

  Other effects of the fourth embodiment are the same as those of the first to third embodiments.

(Fifth embodiment)
Next, the structure of the light projecting device 301 according to the fifth embodiment of the invention will be described with reference to FIGS.

  In the light projecting device 301 according to the fifth embodiment of the present invention, as shown in FIG. 34, the light projecting unit 320 includes a light collecting member 21, a fluorescent member 22, a reflecting member 23, and a support member that supports the fluorescent member 22. 329 and a lens (projection lens) 330.

  In the condensing member 21 of this embodiment, as shown in FIG. 35, the light-incidence surface 21a is formed in the rectangular shape. Unlike the above-described embodiment, the light emission surface 21b is formed asymmetrically left and right, and has a shape corresponding to a light projection pattern P of a low beam (passing headlight). Specifically, the light incident surface 21a has a height (H21a) of about 3 mm and a width (W21a) of about 10 mm. Further, the light exit surface 21b is formed in a shape such that the upper right portion is cut out, and has different heights on the left and right. Note that the left means the left side (the opposite side to the C direction) in the traveling direction of the automobile, and is the right in FIG. Moreover, the right means the right side (C direction side) toward the traveling direction of the automobile, and is left in FIG. The left portion of the light exit surface 21b has a height (HL21b) of about 1.9 mm, and the right portion has a height (HR21b) of about 1.5 mm. The end of the lower surface 21d on the light emitting surface 21b side has a width (W21d) of about 6 mm. Further, W21e in FIG. 35 has a width of about 3 mm, and W21f has a width of about 2.6 mm. W21g has a width of about 0.4 mm.

  In addition, the light intensity distribution of the laser beam on the light emitting surface 21b of the light collecting member 21 of the present embodiment is uniform as in the first embodiment.

  As shown in FIG. 34, the fluorescent member 22 is disposed in a region including the first focal point F23a of the reflective surface 23a of the reflective member 23. The fluorescent member 22 is provided on a rod-like support member 329 made of, for example, metal. For example, the fluorescent member 22 is formed by applying a resin containing phosphor particles on the support member 329 and curing the resin. The support member 329 is fixed to the reflection surface 23 a of the reflection member 23. The support member 329 may be formed of, for example, glass or resin that transmits light emitted from the fluorescent member 22.

  In the present embodiment, when the fluorescent member 22 is irradiated with laser light, the irradiation region S of the fluorescent member 22 becomes asymmetrical as shown in FIG. Specifically, the irradiation region S is formed so that the projection pattern P of the low beam (passing headlight) becomes a projected image, like the light emitting surface 21b of the light collecting member 21, and the upper right portion is cut away. It becomes a shape like this. In the irradiation area S, lines Sm1, Sm2 and a point Se are formed in which cut-off lines M1 and M2 and elbow points E, which will be described later, of the projection pattern P are projected images. These lines Sm1 and Sm2 constitute part of the edge of the irradiation region S. Point Se is the intersection of line Sm1 and line Sm2.

  As shown in FIG. 34, the reflecting surface 23a of the reflecting member 23 is formed so as to include a part of an elliptical surface. Specifically, the reflecting surface 23a is formed in a shape that is obtained by dividing an elliptical surface by a surface that is orthogonal (intersects) with an axis connecting the first focal point F23a and the second focal point F23b. The reflection surface 23a has a depth of about 30 mm (length in the B direction) and is formed in a circular shape having a radius of about 15 mm when viewed from the light projecting direction (A direction).

  The first focal point F23a of the reflecting surface 23a of the reflecting member 23 is disposed so as to substantially coincide with the point Se (intersection of the lines Sm1 and Sm2) of the irradiation region S of the fluorescent member 22. In other words, the first focal point F <b> 23 a is disposed at a position where an elbow point E (to be described later) of the projection pattern P in the irradiation region S is projected.

  The lens 330 is disposed in front of the reflecting member 23. The lens 330 has a radius of about 15 mm. The focal point F330 of the lens 330 and the second focal point F23b of the reflecting surface 23a of the reflecting member 23 substantially coincide with each other. The lens 330 may be a plano-convex lens, a biconvex lens, or other shapes.

  In the present embodiment, the light emitted from the irradiation region S of the fluorescent member 22 is reflected by the reflecting surface 23a of the reflecting member 23, passes through the second focal point F23b of the reflecting surface 23a, and is projected by the lens 330. And the light projection pattern P of 25m ahead of the light projection apparatus 301 becomes a shape reflecting the irradiation area | region S, as shown in FIG.

  Specifically, the light projection pattern P does not expand in the upper right direction but expands in the left and right direction (horizontal direction) and the lower direction. In this light projection pattern P, the brightness is sharply switched in the cut-off lines M1 and M2, and the illumination light is not irradiated to the area above the cut-off lines M1 and M2. That is, the light projection pattern P is formed in a shape in which the upper right portion is cut away. For this reason, it is possible to suppress the glare light given to the driver of the oncoming vehicle. In addition, the illuminance of the region R101 (region in front of the automobile) in the vicinity of the elbow point E, which is the intersection of the cut-off lines M1 and M2, is highest, and the illuminance decreases as the distance from the region R101 increases. That is, the illuminance decreases in the order of the regions R101, R102, and R103.

  Incidentally, in the left-side traveling country such as Japan, the low beam of the automobile requires a light projection pattern P with the upper right portion cut away as shown in FIG. In the cut-off lines M1 and M2, it is necessary to switch the brightness sharply so as not to give glare light to the driver of the oncoming vehicle.

  As described above, the light projecting device 301 according to the present embodiment sufficiently satisfies the light projecting pattern P required as a low beam of an automobile.

  The remaining structure of the fifth embodiment is similar to that of the aforementioned first to fourth embodiments.

  In the present embodiment, as described above, the light emission surface 21b has an asymmetric shape in the left-right direction. Thereby, since the irradiation area | region S can be easily made into an asymmetrical shape in the left-right direction, the light projection pattern P can be easily made into an asymmetrical shape in the left-right direction.

  Further, as described above, the first focal point F23a of the reflecting surface 23a of the reflecting member 23 is disposed on the lines Sm1 and Sm2 which are portions of the irradiation region S where the cut-off lines M1 and M2 of the projection pattern P are projected. Has been. This is particularly effective because the brightness can be sharply switched in the cut-off lines M1 and M2.

  Further, as described above, the first focal point F23a of the reflecting surface 23a of the reflecting member 23 is disposed at a position where the elbow point E of the projection pattern P in the irradiation region S is projected. Thereby, the brightness can be switched sharply in the vicinity of the elbow point E, which is more effective. Further, the vicinity of the elbow point E can be brightened most. That is, the area directly in front of the automobile (area R101) can be illuminated most brightly. Further, by arranging the first focal point F23a at a position where the elbow point E in the irradiation area S is projected (a central position in the left-right direction of the irradiation area S), the lower portion of the light projection pattern P is set in the left-right direction. It can be formed substantially symmetrically.

  Further, as described above, the light emitted from the irradiation region S is reflected by the reflecting surface 23a, is projected by the lens 330 through the second focal point F23b of the reflecting surface 23a. At this time, since the second focal point F23b of the reflecting surface 23a and the focal point F330 of the lens 330 coincide with each other, the light projection pattern P formed by the lens 330 easily reflects the shape of the irradiation region S. Note that when the light is projected using the lens 330, the light projection pattern P more easily reflects the shape of the irradiation region S than when the light is projected by the reflecting member 23 without providing the lens 330. Further, by providing the reflecting member 23, more light emitted from the fluorescent member 22 can be used as illumination light than when the light is projected by the lens 330 without providing the reflecting member 23. Thereby, the utilization efficiency of light can be improved.

  Other effects of the fifth embodiment are the same as those of the first to fourth embodiments.

(Sixth embodiment)
Next, with reference to FIGS. 39 and 40, the structure of the light projecting device 401 according to the sixth embodiment of the present invention will be described.

  In the light projecting device 401 according to the sixth embodiment of the present invention, as shown in FIG. 39, the light projecting unit 420 includes a light collecting member 21, a fluorescent member 22, a support member 329 that supports the fluorescent member 22, and a lens 330. Including.

  The support member 329 is formed to transmit the light emitted from the fluorescent member 22. Note that the support member 329 may be formed to shield (absorb) only the excitation light.

  The lens 330 is disposed in front of the fluorescent member 22. The focal point F330 of the lens 330 is disposed so as to substantially coincide with the point Se (intersection of the lines Sm1 and Sm2) of the irradiation region S of the fluorescent member 22.

  As shown in FIG. 40, the light collecting member 21 of the present embodiment is arranged so that the light collecting member 21 of the fifth embodiment is rotated 180 degrees. This is because, in the light projecting device 401, the shape of the irradiation region S of the fluorescent member 22 is rotated 180 degrees and reflected in the light projecting pattern P.

  In the light projecting device 401, light emitted from the back surface of the fluorescent member 23 is projected by the lens 330.

  The remaining structure of the sixth embodiment is similar to that of the aforementioned fifth embodiment.

  In the present embodiment, the focal point F330 of the lens 330 is disposed in the irradiation region S as described above. Thereby, the light projection pattern P formed by the lens 330 reflects the shape of the irradiation region S. When light is projected using the lens 330, the light projection pattern P more easily reflects the shape of the irradiation region S than when light is projected by the reflecting member 23 without providing the lens 330. .

  The other effects of the sixth embodiment are the same as those of the fifth embodiment.

(Seventh embodiment)
Next, with reference to FIG. 41, the structure of the light projector 501 by 7th Embodiment of this invention is demonstrated.

  In the light projection device 501 according to the seventh embodiment of the present invention, as shown in FIG. 41, the light collecting member 21 is formed in the same manner as the light collecting member 21 in the sixth embodiment.

  The reflection member 23 is formed in the same manner as the reflection member 23 of the first embodiment.

  Similar to the fifth and sixth embodiments, the focal point F23 of the reflecting surface 23a of the reflecting member 23 is disposed so as to substantially coincide with the point Se (intersection of the lines Sm1 and Sm2) of the irradiation region S of the fluorescent member 22. .

  In the present embodiment, the light emitted from the irradiation region S of the fluorescent member 22 is projected by being reflected by the reflecting surface 23 a of the reflecting member 23.

  The remaining structure of the seventh embodiment is similar to that of the aforementioned first embodiment.

  The effect of the seventh embodiment is the same as that of the first and fifth embodiments.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiments but by the scope of claims for patent, and further includes all modifications within the meaning and scope equivalent to the scope of claims for patent.

  For example, in the said embodiment, although the example which used the light projector of this invention for the headlamp of the motor vehicle was shown, this invention is not restricted to this. You may use the light projection apparatus of this invention for the headlamp of an airplane, a ship, a robot, a motorcycle or a bicycle, and another moving body.

  Moreover, although the said embodiment showed about the example which applied the light projector of this invention to the headlamp, this invention is not limited to this. You may apply the light projector of this invention to a downlight or a spotlight, and another light projector.

  Moreover, although the example which converted excitation light into visible light was shown in the said embodiment, this invention is not limited to this, You may convert excitation light into light other than visible light. For example, when the excitation light is converted into infrared light, it can also be applied to a night illumination device of a security CCD camera.

  In the above embodiment, an example in which the excitation light source (semiconductor laser element) and the fluorescent member are configured to emit white light has been described. However, the present invention is not limited to this. The excitation light source and the fluorescent member may be configured to emit light other than white light.

  In the above embodiment, an example in which a semiconductor laser element is used as a laser generator that emits laser light has been described. However, the present invention is not limited to this, and a laser generator other than a semiconductor laser element may be used. .

  Moreover, the numerical value shown by the said embodiment is an example, and each numerical value is not limited.

In addition, the center wavelength of the laser light emitted from the semiconductor laser element of the above embodiment and the type of phosphor constituting the fluorescent member can be appropriately changed. For example, a semiconductor laser element that emits blue laser light having a center wavelength of about 450 nm and a phosphor that converts part of the blue laser light into yellow light may be used. In addition, when the excitation light (laser light) is sufficiently diffused by the fluorescent member and safety can be ensured, it is not necessary to provide a filter member that blocks the excitation light. In this case, white light is obtained by blue light and yellow light. As the phosphor that converts some of the blue laser light into yellow light, for example, _{(Y 1-x-y Gd} x Ce y) 3 Al 5 O 12 (0.1 ≦ x ≦ 0.55,0 .01 ≦ y ≦ 0.4). Moreover, the present invention is not limited to this, and the center wavelength of the laser light emitted from the semiconductor laser element may be arbitrarily selected in the range of ultraviolet light to visible light.

  Moreover, although the said embodiment showed about the example which formed the light-projection surface of the condensing member in rectangular shape, long hexagonal shape, etc., this invention is not limited to this. For example, as in the light collecting member 21 according to the first modification of the present invention shown in FIG. 42, the light emission surface 21b may be formed in an elliptical shape. Moreover, you may form a light-projection surface asymmetrical up and down and right and left. What is necessary is just to set the shape of a light-projection surface so that a required light projection pattern may be obtained.

  In the fifth to seventh embodiments, the example in which the lens is provided at a predetermined distance from the fluorescent member has been described. However, the present invention is not limited to this. For example, a lens 630 (light projecting member) may be provided so as to cover the fluorescent member 22 as in the light projecting device according to the second modification of the present invention shown in FIG. If comprised in this way, the light radiate | emitted from the fluorescent member 22 permeate | transmits and refracts the lens 630, and is radiate | emitted outside, and becomes a long light projection pattern. 44, the lens 730 may be formed by filling the inside of the reflecting surface 23a of the reflecting member 23 with resin, glass, or the like as in the light projecting device 701 according to the third modification of the present invention shown in FIG. . Further, as in the fifth to seventh embodiments, a projection lens (projection lens) (not shown) may be disposed in front of the fluorescent member 22. In addition to the reflecting member and the lens, a prism or the like may be used as the light projecting member.

  Moreover, although the said embodiment showed about the example which formed the reflective surface of the reflective member by a part of paraboloid or a part of elliptical surface, this invention is not limited to this. The reflecting surface may be formed by a multi-reflector composed of a large number of curved surfaces (for example, a parabolic surface) or a free curved surface reflector provided with a large number of fine flat surfaces.

  Further, for example, in the fifth embodiment, the example in which the reflecting surface 23a of the reflecting member 23 is formed in a circular shape when viewed from the light projecting direction (A direction) is shown, but the present invention is not limited to this. For example, like the light projecting device 801 of the fourth modified example of the present invention shown in FIG. 45, the reflecting surface 23a of the reflecting member 23 is formed so as to include a part of an elliptical surface, and viewed from the light projecting direction. It may be formed in a substantially semicircular shape. In the light projecting device 801, as in the fifth embodiment, the first focal point F23a of the reflecting surface 23a of the reflecting member 23 is disposed so as to substantially coincide with the point Se of the irradiation region S of the fluorescent member 22. Further, the focal point F330 of the lens 330 and the second focal point F23b of the reflecting surface 23a of the reflecting member 23 substantially coincide with each other. Note that the upper half of the lens 330 may be omitted.

  Moreover, in the said 6th Embodiment, when the reflecting member 23 was not provided, the example which projects the light radiate | emitted from the back surface of the fluorescent member 22 with the lens 330 was shown, However, This invention is not limited to this. For example, as in the light projection device 901 of the fifth modification example of the present invention shown in FIG. 46, the fluorescent member 22 is irradiated with laser light from the lens 330 side, and the light emitted from the irradiation surface 22a of the fluorescent member 22 is reflected. The light may be projected by the lens 330 without using the member 23.

  Moreover, although the said 5th-7th embodiment showed about the example which formed the light projection pattern in the shape which notched the upper right part, without using a light-shielding plate, this invention is not limited to this. For example, a light shielding plate may be provided between the reflecting member (or fluorescent member) and the lens. If comprised in this way, the brightness of the edge part of a light projection pattern can be switched more steeply, or a more complicated light projection pattern can be obtained. In addition, by forming the light emission surface of the light collecting member into a shape corresponding to the light projection pattern as in the fifth to seventh embodiments, the shape of the irradiation region and the light projection pattern can be set in advance. Therefore, the amount of light shielded by the light shielding plate can be reduced. Thereby, it can suppress that the utilization efficiency of light falls.

  Moreover, in the said 5th-7th embodiment, although the case where it uses in the left-hand drive country, such as Japan, was shown as an example, the example which obtains the light projection pattern which notched the upper right part was shown, but this invention is shown to this Not exclusively. When used in a country traveling on the right side, if the shape of the light exit surface of the light collecting member is reversed left and right, a light projection pattern in which the upper left portion is cut out can be obtained.

  In the above embodiment, an example in which a plurality of semiconductor laser elements are used as the excitation light source has been described. However, the present invention is not limited to this. One semiconductor laser element may be used as the excitation light source. A so-called semiconductor laser array having a plurality of light emitting units may be used as the excitation light source.

  Moreover, although the said embodiment showed the example which reflects the laser beam which injected into the light-incidence surface of the condensing member by the upper surface, a lower surface, and a side surface, and was guided to the light-projection surface, this invention is not limited to this. For example, by forming the condensing member so that the refractive index decreases smoothly or stepwise from the inside to the outside like a graded index optical fiber, the traveling direction of the laser light is changed to the inside of the condensing member. The laser beam may be guided to the light emitting surface by changing the above.

  Moreover, in the said embodiment, although the example which excited the fluorescent member horizontally long (shape long in a horizontal direction) was shown, this invention is not limited to this. The fluorescent member may be excited, for example, in a vertically long shape (long shape in the vertical direction) or in a long shape in the oblique direction.

  Further, a configuration obtained by appropriately combining the configurations of the above-described embodiment and modification examples is also included in the technical scope of the present invention.

  In the fifth to seventh embodiments, the example in which the focal point of the light projecting member is arranged at the edge of the irradiation region in the light projecting device capable of obtaining a long light projecting pattern has been described. Then, it has been explained that light and dark can be sharply switched in a portion (cut-off line) corresponding to the edge of the irradiation region where the focal point of the light projecting member is arranged in the light project pattern. However, even in a light projection device that obtains a light projection pattern other than the long shape, the same effect can be obtained if the focal point of the light projection member is arranged at the edge (or in the vicinity of the edge) of the irradiation region. That is, a fluorescent member that is excited by excitation light and a light projecting member that reflects or transmits light emitted from the fluorescent member and emits the light to the outside. The fluorescent member is irradiated with the excitation light. In the light projecting device, the focal point of the light projecting member is arranged at or near the edge of the radiation region. Brightness and darkness can be switched sharply at a portion corresponding to the edge of the irradiation region where the focal point is arranged. Needless to say, this can also be said when the excitation light source is a light source other than the laser light source (for example, a light emitting diode).

1, 101, 201, 301, 401, 501, 701, 801, 901 Projection device 11 Semiconductor laser element 20, 120, 220, 320, 420 Projection unit 21 Condensing member 21a Light incident surface 21b Light exit surface 22 Fluorescence Member 23 Reflective member (light projecting member)
23a Reflecting surface 330, 630, 730 Lens (light projecting member)
E Elbow point F23 Focus F23a First focus (focus)
F23b Second focus (focus)
F330 focus H21b height (length in the second direction of the light exit surface)
Lc length (length of irradiation region in first direction)
Ld length (length of irradiation region in second direction)
Ls1 length (length from the focal point to the end of the irradiation area in the third direction)
Ls2 length (length of irradiation area in the fourth direction)
M1, M2 Cut-off line P Projection pattern S Irradiation area W21b Width (length of light emitting surface in first direction)

Claims (8)

A light incident surface on which excitation light is incident, and a condensing member including a light exit surface that has an area smaller than the light incident surface and emits the excitation light;
A fluorescent member excited by the excitation light emitted from the light exit surface of the light collecting member;
A light projecting member that reflects or transmits light emitted from the fluorescent member,
With
The fluorescent member includes an irradiation region irradiated with the excitation light,
The length of the first direction of the irradiation region is much larger than the length in a second direction perpendicular to the first direction of the irradiation region,
The length of the light exit surface in the first direction is greater than the length of the light exit surface in the second direction,
The light projecting device, wherein the light emitting surface has an asymmetric shape in the first direction .   Used for automotive headlamps,
  The light projecting device according to claim 1, wherein the light emitting surface is formed in a shape corresponding to a light projecting pattern of a passing headlamp. Light projecting device of claim 1 or 2 focal point of the light projection member is characterized by being located on the edge of the irradiated region. Used for automotive headlamps,
The light projecting device according to claim 3 , wherein a focal point of the light projecting member is disposed at an edge portion that projects a cut-off line of a light projecting pattern in the irradiation region. The light projecting device according to claim 4 , wherein a focal point of the light projecting member is disposed at a position where an elbow point of a light projecting pattern is projected in the irradiation region. Light projecting device according to any one of claims 1 to 5, wherein the first length of the irradiation region and wherein the at least three times greater than the second direction length of the irradiation region. A condensing member for condensing excitation light and irradiating the fluorescent member,
A light incident surface on which excitation light is incident;
A light exit surface having an area smaller than the light incident surface and emitting the excitation light;
With
Length in the first direction of the light exit surface is much larger than the second direction length perpendicular to the first direction of the light exit surface,
The light condensing member, wherein the light emitting surface has an asymmetric shape in the first direction . The light collecting member according to claim 7 ;
A light projecting unit comprising a fluorescent member irradiated with excitation light emitted from the light collecting member.

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