JP7183876B2 - lighting equipment - Google Patents

Description

The present invention relates to lighting fixtures.

2. Description of the Related Art There is known a lighting fixture that excites a plurality of laser beams as excitation light to a phosphor and uses fluorescence emitted from the phosphor due to the excitation for illumination (see, for example, Patent Document 1).

JP 2004-241142 A

Laser light has higher coherence than, for example, LED light and the like, and has a great effect on the human body. However, in conventional lighting fixtures, due to various factors such as misalignment of parts due to impacts, etc., there is a concern that the laser light may come off the fluorescent material and leak to the outside as it is.

An object of the present invention is to provide a lighting fixture capable of suppressing leakage of laser light.

The present invention comprises a first reflecting surface for collimating light from a focal point, a phosphor provided on the first reflecting surface positioned at the focal point of the first reflecting surface, and an optical axis of the first reflecting surface. and a laser light source that irradiates the phosphor with a laser beam from an oblique direction and emits fluorescence from the phosphor, wherein the laser light reflected by the first reflecting surface and the laser light emitted from the phosphor A lighting fixture that illuminates the fluorescent light with parallel light collimated by the first reflecting surface, comprising a plurality of light shielding plates fixedly arranged in parallel with the optical axis of the first reflecting surface, and the phosphor a laser light shielding unit for shielding the leaked light component of the laser light outside the laser light shielding plate, wherein the plurality of laser light sources are arranged around the optical axis, and each of the light shielding plates extends along the optical axis; It is formed in an annular shape surrounding the light shielding plate, is arranged coaxially and concentrically with the optical axis, and the height Hn of each of the light shielding plates in the direction of the optical axis and the arrangement interval Dn satisfy the _{following equation} . A lighting fixture characterized by:
H _n ≥ D _n tan (90-α _n-1 )
However, n represents the order of the light shielding plates counted from the optical axis, and α _n is the incident angle with respect to the optical axis of the leaked light component incident on the n-th light shielding plate.

According to the present invention, in the above lighting equipment, a plurality of the laser light sources are arranged around the optical axis, and each of the light shielding plates is formed in an annular shape surrounding the optical axis and is coaxially and concentrically with the optical axis. It is characterized by being arranged in a shape.

The present invention is characterized in that, in the lighting equipment described above, the height _Hn of each of the light shielding plates in the direction of the optical axis and the arrangement interval _Dn satisfy the following equations.
H _n ≥ D _n tan (90-α _n-1 )
However, n represents the order of the light shielding plates counted from the optical axis, and α _n is the incident angle with respect to the optical axis of the leaked light component incident on the n-th light shielding plate.

The present invention is characterized in that, in the lighting fixture, the diameter of the outermost light blocking plate exceeds 50% of the diameter of the open end surface of the first reflecting surface.

According to the present invention, the above-described lighting fixture is characterized by further comprising a wall surface positioned outside the first reflecting surface and shielding leaked light components passing through the laser beam shielding unit.

The present invention is characterized in that, in the above lighting equipment, the light shielding plates have the same height _Hn .

The present invention is characterized in that, in the above lighting fixture, each of the light blocking plates has high thermal conductivity and is engaged with a holding member that holds the phosphor.

The present invention is characterized in that, in the above lighting fixture, antireflection treatment is applied to each of the light shielding plates.

According to the present invention, leakage of laser light can be suppressed.

BRIEF DESCRIPTION OF THE DRAWINGS It is a perspective view which shows the whole structure of the light projecting device which concerns on embodiment of this invention. It is the perspective view which looked at the back side of the light projecting device. It is a front view of a light projecting device. FIG. 4 is a cross-sectional view taken along line IV-IV of FIG. 3; FIG. 4 is a cross-sectional view taken along the line VV of FIG. 3; It is a perspective view which shows the longitudinal cross-section of the light projecting device cut by the plane containing the optical axis of a reflecting mirror. FIG. 3 is a perspective view showing the internal configuration of the light projecting device with the front cover, the laser light shielding unit, and one of the reflecting mirrors removed. 5 is an enlarged view of the light source unit shown in FIG. 4; FIG. FIG. 4 is an exploded view showing assembly of the laser light shielding unit; FIG. 2 is an exploded view showing a back surface configuration of a laser light shielding unit and a phosphor holding bar; FIG. 10 is a diagram showing a relationship between a light shielding plate and an incident angle α of leaked light; FIG. 5 is a diagram showing the relationship between the aperture coverage ratio of the light shielding plate and the light shielding performance evaluation in the laser light shielding unit. FIG. 3 is a perspective view showing the internal configuration of the light projecting device with the front cover, the laser light shielding unit, and the reflecting mirror removed; It is a longitudinal cross-sectional view which shows the internal structure of a light projecting device. It is a figure showing composition of a projection device concerning a modification of the present invention. It is a figure which shows arrangement|positioning of the illumination intensity sensor based on the modification of this invention.

Embodiments of the present invention will be described below with reference to the drawings. In the following, as one aspect of the lighting device, a light projecting device that is suitably used for landscape lighting will be exemplified.

FIG. 1 is a perspective view showing the overall configuration of a light projecting device 1 according to this embodiment, and FIG. 2 is a perspective view of the rear side of the light projecting device 1. As shown in FIG. 3 is a front view of the light projecting device 1. FIG.
The light projecting device 1 includes, as shown in FIGS. 1 to 3 , a substantially box-shaped device body 2 that emits illumination light, and a mounting arm 4 that supports the device body 2 . The mounting arm 4 includes an arm portion 5 supporting both side surfaces of the device main body 2 and a fixing piece 6 provided on the arm portion 5. The fixing piece 6 is fixed to the installation location of the light projecting device 1. be done. The arm portion 5 rotatably (tiltably) supports the apparatus main body 2 so that the mounting angle of the apparatus main body 2 can be changed.

The apparatus main body 2 has a substantially box-shaped housing 8 with an open front surface (also referred to as a front surface). The housing 8 is formed by die-casting using, for example, aluminum having high thermal conductivity, and as shown in FIG.

A flange 10 is formed at the edge of the front opening of the housing 8, and a front cover 12 is fixed to the flange 10 as shown in FIGS. The front cover 12 has a substantially rectangular plate-like shape made of a transparent material (for example, glass or transparent resin). A light-shielding coating (black ink coating in this embodiment) is applied by screen printing).

As shown in FIG. 3, the emission region 16 is a transparent region having a circular shape when viewed from the front, and through this emission region 16, substantially parallel light with a circular beam cross section and white light is emitted from the device main body 2 as illumination light. be done. In the light projecting device 1 of the present embodiment, two emission areas 16 are provided side by side on the front cover 12, and substantially parallel illumination light is emitted from each emission area 16. FIG.

4 is a sectional view taken along line IV-IV in FIG. 3, and FIG. 5 is a sectional view taken along line VV in FIG.
The light projecting device 1 of this embodiment is a device that obtains white light by mixing blue laser light that excites the phosphor 22 and yellow fluorescence that is generated by being excited by the laser light. Specifically, as shown in FIG. 4, the apparatus main body 2 is provided with a light source unit 20, a phosphor 22, a reflector 24, and a laser light shielding unit 60 for each emission area 16. .

The light source unit 20 is a unit that irradiates the phosphor 22 with blue laser light. The phosphor 22 is a member that is excited by laser light irradiation and emits yellow fluorescence toward the reflecting mirror 24 . As the phosphor 22 of the present embodiment, an extremely thin film (LAG-Sc) produced by mixing LAG-based phosphor particles with an inorganic binder made of scandium or the like is used. The phosphor 22 is formed on the surface of the phosphor holder 27 by printing. A YAG-Ce single crystal or the like can also be used as the phosphor 22 .
The reflecting mirror 24 is a reflective optical member having a parabolic reflecting surface 24A that converts the light from the focal point f into parallel light parallel to the optical axis K. FIG. At the focal point f of the parabolic reflecting surface 24A, the phosphor 22 is arranged to face the parabolic reflecting surface 24A. Specifically, as shown in FIG. 4, the device main body 2 includes a rod-like phosphor holding bar 28 having a phosphor holding portion 27 that holds the phosphor 22 . The phosphor 22 of the phosphor holding portion 27 (more precisely, a flat reflecting surface 27A to be described later) is positioned at the focal point f, and the phosphor holding bar 28 is attached to the housing 8 in a posture extending in the direction orthogonal to the optical axis K. Fixed.

As shown in FIG. 4, the phosphor holder 27 has a planar reflecting surface 27A that holds the phosphor 22. The laser beam incident on the phosphor 22 is reflected by the planar reflecting surface 27A. It reflects toward the parabolic reflecting surface 24A. As a result, white light, which is mixed light with fluorescent light and laser light, is emitted from the phosphor 22 toward the parabolic reflecting surface 24A in a substantially Lambertian distribution. When this white light is incident on the parabolic reflection surface 24A, it is collimated into light parallel to the optical axis K of the parabolic reflection surface 24A, passes through the emission area 16 of the front cover 12, and is used as illumination light. It is emitted from the main body 2 .

FIG. 6 is a perspective view showing a longitudinal section of the light projecting device 1 cut along a plane including the optical axis K of the reflecting mirror 24. As shown in FIG. FIG. 7 is a perspective view showing the internal configuration of the light projecting device 1 with the front cover 12, the laser light shielding unit 60, and the reflecting mirror 24 on one side removed. 8 is an enlarged view of the light source unit 20 shown in FIG. 4. FIG.
The light source unit 20 irradiates the phosphor 22 with a plurality of laser beams from around the optical axis K, and as shown in FIG. and an assembly member 32 to which the laser light source unit 30 is assembled.
The assembly member 32 is a rectangular plate-shaped member in front view, and is attached and fixed to a mounting plate 34 fixed to the bottom surface 8A of the housing 8 as shown in FIGS. Both the assembly member 32 and the mounting plate 34 are made of a material with high thermal conductivity such as aluminum, and transmit the heat generated by the laser light source unit 30 to the housing 8 to dissipate the radiation fins 14 on the rear surface of the housing 8. The heat is smoothly dissipated from the

As shown in FIG. 8, the laser light source unit 30 includes a laser diode 36 that outputs laser light, and a lens 38 that condenses the laser light into a predetermined spot shape at the focal point f of the parabolic reflection surface 24A. The lens 38 is a biconic lens, and in addition to the light-condensing function, when the phosphor 22 is irradiated with the cross-sectional shape of the laser light emitted from the laser diode 36, the shape such as a perfect circle or a square shape (such It has a function of shaping so as to approximate a shape corresponding to the planar view shape of the phosphor 22 .

As shown in FIG. 8, the assembly member 32 has a cup-shaped recess on its surface, and a plurality of mounting recesses 40 are formed on the peripheral surface of the recess at approximately equal intervals around the optical axis K. The laser light source unit 30 is accommodated in the mounting recess 40 . Each laser light source unit 30 is pressed and fixed to the assembly member 32 by a pressing plate 42 from above.

Each mounting recess 40 is formed so as to arrange each laser light source unit 30 at the same incident angle and at the same distance when viewed from the focal point f. In this embodiment, each laser light source unit 30 is arranged behind the parabolic reflection surface 24A when viewed from the focal point f. As shown in FIG. A through hole 46 is provided for passing laser light. In this embodiment, the incident angle of each laser beam with respect to the optical axis K when entering the phosphor 22 is set to a predetermined angle (30 degrees in this embodiment) that is at least greater than zero degrees.

As shown in FIG. 8, the mounting plate 34 has a columnar portion 44 erected perpendicularly to its surface, and both the reflecting mirror 24 and the laser light source unit 30 are engaged with the columnar portion 44 during assembly. position. As a result, the relative positions of the parabolic reflecting surface 24A and each laser light source unit 30 are matched with high accuracy.

However, not all of the laser light emitted from the laser diode 36 is irradiated onto the phosphor 22 due to variations in the laser diode 36 and the lens 38, reflection and diffraction at the through hole 46, and only a small amount of the laser light is irradiated. is emitted outside the phosphor 22 (hereinafter referred to as "leakage light component"). In the light projecting device 1 of the present embodiment, this leaked light component is blocked by the laser light blocking unit 60 described above, and the laser light blocking unit 60 will be described in detail below.

FIG. 9 is an exploded view showing assembly of the laser light shielding unit 60, and FIG.
The laser light shielding unit 60 is a member that shields leakage light components of the laser light that may be emitted from the emission region 16 together with the illumination light. Specifically, the laser light shielding unit 60 shields the leakage light component of the laser light that does not enter the phosphor 22 while passing the illumination light collimated by the parabolic reflection surface 24A. As shown in FIGS. 4 and 5, the laser light blocking unit 60 is arranged between the opening end face 29 of the parabolic reflecting surface 24A and the front cover 12 while being supported by the phosphor holding bar 28. be.

As shown in FIGS. 9 and 10, the laser light shielding unit 60 includes a plurality of light shielding plates 62 fixedly arranged concentrically and having different diameters, and light shielding plates 62 radially extending in the radial direction of the concentric circles. a plurality of support plates 64 that support 62; The light-shielding plate 62 has a tubular shape formed by bending a strip-shaped thin metal plate into an annular shape (annular shape in this embodiment). function as light shielding surfaces 65 for shielding light. Both surfaces of the support plate 64 are also subjected to antireflection treatment in the same manner as the light shielding plate 62 . By performing the antireflection treatment, it is possible to suppress the reflection of the leakage light component in the laser light shielding unit 60 and prevent the leakage light component from being emitted by the reflection.

As shown in FIG. 3, the laser beam shielding unit 60 is arranged so that the central axis of the concentric circles coincides with the optical axis K. , and fixedly arranged parallel to the optical axis K as shown in FIG. By fixing the light shielding plate 62 (light shielding surface 65) in parallel with the optical axis K in this way, the illumination light, which is parallel light parallel to the optical axis K, can pass through without being shielded by the light shielding surface 65. Become.
On the other hand, since the laser light is incident on the phosphor 22 at an incident angle larger than zero degrees (that is, obliquely with respect to the optical axis K), when part of the laser light deviates from the phosphor 22, , does not become light parallel to the optical axis K, but enters the light shielding surface 65 of the light shielding plate 62 as it is, and is shielded by the light shielding surface 65 .

As a result, even if part of the laser light has deviated from the fluorescent material 22, it is possible to prevent the leakage light component of the laser light from being emitted directly from the device main body 2 while suppressing the decrease in luminous intensity due to the blocking of the illumination light. It is possible to realize illumination with high luminosity compared to the case of using an incoherent light source such as an LED.

Furthermore, in this laser beam shielding unit 60, since the shielding plate 62 is provided so as to surround the optical axis K, regardless of the positions of the laser light source units 30 arranged around the optical axis K, each Leakage light components of the laser light from the laser light source unit 30 can be shielded.

As shown in FIG. 10, each light shielding plate 62 is formed with a notch recess 68 into which the phosphor holding bar 28 is inserted and engaged. The phosphor holding bar 28 is engaged with each notch recess 68 and attached. As described above, each light shielding plate 62 is generally made of a metal having high thermal conductivity, and thus functions as a heat dissipation portion for dissipating heat transferred from the phosphor 22 to the phosphor holding bar 28. The heat dissipation performance of the body 22 is enhanced.

FIG. 11 is a diagram showing the relationship between the light blocking plate 62 and the incident angle α of leaked light.
In the figure, the subscript n represents the order of the light shielding plates 62 counted from the central axis (optical axis K) of the concentric circles, and α _n represents the incident angle of the leaked light incident on the n-th light shielding plate 62 with respect to the optical axis K. . In addition, in order to eliminate the influence of the displacement of the laser light source unit 30 and the shielding of the laser light by the through hole 46, the position of the through hole 46 of the parabolic reflection surface 24A (through hole 46 center point).

As shown in the figure, the end portions of the light shielding plates 62 are aligned on the same plane (in the illustrated example, the opening end surface 29 of the parabolic reflecting surface 24A). The leaked light N passing through the light shielding plate 62 is directed to the opening end face 29 of the reflecting mirror 24 at an incident angle _α2 to the light shielding plate 62 . In this case, if the arrangement interval _D3 between the second and third light shielding plates 62 and the height _H3 of the third light shielding plate 62 satisfy the relationship of the following equation (1), the leaked light N is reduced to the third light shielding plate 62 It can be seen that the light shielding plate 62 can shield all the light.

H ₃ /D _{3 =} tan(90-α ₂ ) (1)

Therefore, with respect to the n-th light shielding plate 62, the arrangement interval _Dn and the height Hn satisfy the following expression (2), so that the _n -th light shielding plate 62 becomes the n-1th and the n-th It can be seen that all of the leaked light N passing through the light shielding plates 62 can be blocked.

_Hn ≧ _Dn ·tan(90−αn ₋₁ ) (2)

In the laser light shielding unit 60 of the present embodiment, as shown in FIGS. 4 and 5, the height _Hn of each light shielding plate 62 is set to the same value, and each light shielding plate 62 is obtained by formula (2 ) are arranged at the arrangement interval _Dn obtained according to ). As a result, substantially all of the leaked light passing through between the light shielding plates 62 is blocked and prevented from being emitted to the outside. Further, since the height _Hn of each light shielding plate 62 is set to the same value, the laser light shielding unit 60 can be mounted without providing an excessive gap between the opening end surface 29 of the parabolic reflecting surface 24A and the front cover 12. can be placed efficiently. In addition, when the heights _Hn of the light shielding plates 62 are all the same, the arrangement interval _Dn of the light shielding plates 62 becomes narrower as the light shielding plates 62 are closer to the optical axis K. FIG. As described above, the light shielding plate 62 also functions as a heat radiating portion for the phosphor 22. Therefore, the light shielding plate 62 is arranged relatively densely near the phosphor 22, so that the phosphor 22 can be efficiently dissipated. become.

In addition, when most of the laser light is incident on the phosphor 22 and a slight leakage light component is generated due to a slight positional deviation between the parabolic reflection surface 24A and the laser light source unit 30 or an error in optical design. , most of the leaked light components are oriented in the direction where the incident angle α to the phosphor 22 is larger than the incident angle α0, and only a small amount of the leaked light components are oriented in the opposite direction.
Therefore, when the laser light source units 30 are arranged around the optical axis K at the same distance from the focal point f and at the same incident angle, the plurality of light shielding plates 62 are arranged at a height that satisfies the above formula (2). By providing them concentrically with the optical axis K with the height H _n and the arrangement interval D _n , most of the leakage light component of the laser light from each laser light source unit 30 can be blocked.

FIG. 12 is a diagram showing the relationship between the opening coverage ratio of the light shielding plate 62 and the light shielding performance evaluation in the laser light shielding unit 60. As shown in FIG.
The aperture coverage ratio is a value that indicates the extent to which the laser light shielding unit 60 occupies the aperture end surface 29 of the parabolic reflecting surface 24A. Such an aperture coverage ratio is determined by the ratio of the diameter Ra of the outermost light shielding plate 62 of the laser light shielding unit 60 to the diameter of the opening end face 29 (220 mm in the illustrated example). The diameter Ra of the outermost light shielding plate 62 can also be obtained by adding the arrangement interval Dn of each light shielding plate 62 and multiplying the result by two, and can also be expressed as Ra=2· _ΣDn .
In the laser light shielding unit 60 shown in the figure, the height _Hn of all the shielding plates 62 is 20 mm, and the equal sign (=) are arranged at an arrangement interval _Dn that satisfies

As can be seen from the figure, the laser beam shielding unit 60 has higher shielding performance as the opening coverage ratio increases. In addition, it can be seen that an opening coverage ratio of about 50% or more is necessary to obtain a light shielding performance that sufficiently shields leaked light from the standpoint of safety. In other words, considering that the illuminance of the leaked light component decreases with increasing distance from the optical axis K, if the leaked light component is shielded with an aperture coverage of about 50%, most of the laser light component can be blocked by the laser light shielding unit. 60 can block the light, and it can be said that the leakage light component passing through the outside of the laser light blocking unit 60 (the side far from the optical axis K) can be suppressed to the extent that there is no problem.

In the laser beam shielding unit 60 of this embodiment, the outermost shielding plate 62 is provided at a position where the aperture coverage ratio is about 70%, so that sufficiently high shielding performance can be obtained. Further, by limiting the aperture coverage to about 70%, it is possible to prevent the light shielding plate 62 from being excessively provided.

11, a wall surface 69 is provided outside the parabolic reflecting surface 24A of the reflecting mirror 24 at a position where the leaked light component enters. Thus, it is possible to prevent leakage light components from being emitted to the outside. In this embodiment, as shown in FIGS. 4 and 5, a wall surface 69 having an antireflection-treated surface is provided inside the flange 10 of the housing 8 so as to surround the laser light shielding unit 60. there is

Here, in addition to the laser light shielding unit 60 for shielding the leaked light component of the laser light, the light projecting device 1 of the present embodiment includes a laser light shielding unit 60 that quickly reduces the laser output of the laser light source unit 30 when the leaked light component is excessively generated. A safety device is built in to stop the Such a safety device will be described below.

FIG. 13 is a perspective view showing the internal configuration of the light projecting device 1 with the front cover 12, the laser light shielding unit 60, and the reflecting mirror 24 removed. 14 is a longitudinal sectional view showing the internal configuration of the light projecting device 1. As shown in FIG.
As shown in FIG. 13 , the light projecting device 1 includes an illuminance sensor board 70 and a cutoff circuit board 72 as the safety devices, which are fixed to the mounting plate 34 .
The illuminance sensor board 70 is a circuit board including an illuminance sensor 70A, which is an example of light detection means for detecting the intensity of illumination light. The illuminance sensor substrate 70 is provided for each reflecting mirror 24 .
The cut-off circuit board 72 detects a predetermined amount of light detected by any of the illuminance sensors 70A (in this embodiment, the rated value of the initial amount of light is used as a reference, and the amount of light is set between 50% and 30% of the reference value). , the circuit board includes a circuit that cuts off the power supply to each laser light source unit 30 and stops the irradiation of all the laser beams to the phosphor 22 when the voltage falls below . The predetermined value of the light quantity is not limited to the method based on the rated value of the initial light quantity. In addition, the method of stopping the irradiation of the laser light is not limited to the method of cutting off the power supply, and the irradiation of the laser light may be stopped by suppressing the current to a current value at which the laser diode 36 does not oscillate.

By providing the illuminance sensor board 70 and the cutoff circuit board 72, even though the phosphor 22 is irradiated with the laser light from the laser light source unit 30, when the light amount of the illumination light decreases, the cutoff circuit The substrate 72 quickly stops the irradiation of the laser light.
Such a decrease in the amount of light occurs in the following cases. For example, when the reflecting mirror 24 or the light source unit 20 is misaligned due to a strong impact applied to the light projecting device 1, and the leakage light component of the laser light not incident on the phosphor 22 increases. For example, it is degraded due to damage or is missing from the phosphor holding portion 27, and a large amount of laser light is reflected by the flat reflecting surface 27A of the phosphor holding portion 27, for example. In both cases, a large amount of laser light can be emitted to the outside. According to the light projecting device 1 of the present embodiment, even in these cases, when the light intensity of the illumination light is greatly reduced (in other words, when a large amount of laser light is emitted to the outside), the laser light Since the irradiation of is stopped, a highly safe instrument can be realized.

As shown in FIGS. 7 and 14, the parabolic reflecting surface 24A of the reflecting mirror 24 is formed with a pinhole 74 through which illumination light passes from the front side to the back side. As shown in FIG. 14, the illuminance sensor 70A is located away from the pinhole 74, and is arranged at a position where the illumination light traveling through the pinhole 74 to the back side of the parabolic reflection surface 24A is incident. ing. Further, the sensor surface 70A1 of the illuminance sensor 70A, the pinhole 74, and the phosphor 22 are arranged on the same straight line, and the illumination light emitted from the phosphor 22 is reliably transmitted through the pinhole 74 to the illuminance sensor 70A. The light is incident on the sensor surface 70A1 and detected.

In this way, since the illuminance sensor 70A is arranged on the back side of the parabolic reflection surface 24A (the position covered by the parabolic reflection surface 24A when viewed from the front), the illuminance sensor 70A is located outside the light projecting device 1. It is possible to accurately detect the amount of illumination light while suppressing the influence of light.
In addition, since the light projecting device 1 includes the plurality of light shielding plates 62 of the laser light shielding unit 60 in front of the parabolic reflection surface 24A, the external light is prevented from entering the parabolic reflection surface 24A. High-precision detection with less influence becomes possible. In particular, since the laser light blocking unit 60 blocks light components not parallel to the optical axis K, the external light components incident on the parabolic reflection surface 24A are only components parallel to the optical axis K. Since the amount of light is narrowed down at , the external light component reaching the illuminance sensor 70A is extremely small.

In addition, as shown in FIG. 14, the sensor surface 70A1 of the illuminance sensor 70A is arranged apart from the pinhole 74. Therefore, compared to the configuration in which the sensor surface 70A1 is arranged in the vicinity of the pinhole 74, the separation distance In addition, due to the spread of light by the pinhole 74, the amount of light detected by the sensor surface 70A1 is weakened. As a result, even when the output of the light projecting device 1 is increased, saturation of the detection value of the illuminance sensor 70A can be prevented and the amount of illumination light can be detected.
In addition, as shown in FIG. 14, the illuminance sensor 70A is arranged so that the illumination light passing through the pinhole 74 is obliquely incident on the sensor surface 70A1. As a result, the illumination light is incident on a wider range of the sensor surface 70A1 and the incident area is increased, so that the saturation of the detected value can be prevented more reliably.

According to the embodiment described above, the following effects are obtained.

The light projecting device 1 of this embodiment has a plurality of light shielding plates 62 fixedly arranged in parallel with the optical axis K of the parabolic reflecting surface 24A, and the leakage light component of the laser beam deviating from the phosphor 22 is blocked by the light shielding plates. Since the laser light shielding unit 60 for shielding the light at 62 is provided, it is possible to shield the leakage light component of the laser light while allowing the illumination light to pass therethrough.

In the light projecting device 1 of this embodiment, a plurality of laser light source units 30 are arranged around the optical axis K, and each of the light shielding plates 62 is formed in an annular shape surrounding the optical axis K. are arranged concentrically on the same axis as the
As a result, regardless of the position of each laser light source unit 30 around the optical axis K, the leak light component of the laser light from each laser light source unit 30 can be blocked by the light shielding plate 62 .

In the light projecting device 1 of the present embodiment, the height _Hn of each of the light shielding plates 62 and the arrangement interval _Dn satisfy the above formula (2).
As a result, substantially all of the leaked light that passes through between the light shielding plates 62 can be blocked and prevented from being emitted to the outside.

In the light projecting device 1 of this embodiment, the diameter of the outermost light blocking plate 62 exceeds 50% of the diameter of the opening end face 29 of the parabolic reflecting surface.
As a result, it is possible to obtain a light shielding performance that sufficiently shields leaked light from the standpoint of safety.

Since the light projecting device 1 of the present embodiment is provided with the wall surface 69 located outside the parabolic reflecting surface 24A and shielding the leakage light component passing through the laser beam shielding unit 60, higher shielding performance can be achieved.

In the light projecting device 1 of the present embodiment, since the heights _Hn of the light shielding plates 62 are made equal, an excessive gap is not provided between the opening end surface 29 of the parabolic reflecting surface 24A and the front cover 12. The laser beam shielding unit 60 can be arranged efficiently.

In the light projecting device 1 of the present embodiment, each of the light shielding plates 62 is made of a material having high thermal conductivity (metal, alloy, other appropriate high thermal conductivity material that can be annularly molded), and the phosphor 22 is It is configured to be engaged with the phosphor holding bar 28 to be held.
As a result, the light shielding plate 62 functions as a heat radiating section that dissipates the heat generated by the phosphor 22, and the cooling performance of the phosphor 22 is enhanced.
Further, when the height _Hn of the light shielding plates 62 is the same, the closer the light shielding plates 62 are to the optical axis K, the narrower the arrangement interval _Dn of the light shielding plates 62 is. , the cooling performance can be improved.

In the light projecting device 1 of the present embodiment, since the light shielding surfaces 65 of the light shielding plates 62 are subjected to antireflection treatment, it is possible to prevent leakage light components reflected by the light shielding plates 62 from being emitted.

In the light projecting device 1 of the present embodiment, the illuminance sensor 70A is arranged apart from the pinhole 74 provided in the parabolic reflection surface 24A. In comparison, the amount of light detected by the sensor surface 70A1 becomes weaker. As a result, even when the output of the light projecting device 1 is increased, saturation of the detection value of the illuminance sensor 70A can be prevented and the amount of illumination light can be detected.

In the light projecting device 1 of the present embodiment, since the pinhole 74 allows the illumination light to pass from the front side to the back side of the parabolic reflection surface 24A, the illumination light can be guided to the illuminance sensor 70A with a simple configuration. In addition, since the illumination light spreads through the pinhole 74, the amount of light detected by the illuminance sensor 70A becomes smaller, and the saturation of the detection value of the illuminance sensor 70A can be prevented to detect the amount of illumination light.

In the light projecting device 1 of this embodiment, the illuminance sensor 70A is used as the light detecting means for detecting the intensity of the illumination light, so the illumination light can be detected with a simple configuration.

In the light projecting device 1 of this embodiment, the phosphor 22, the pinhole 74, and the sensor surface 70A1 of the illuminance sensor 70A are arranged on the same straight line. 74 can be reliably detected by the illuminance sensor 70A.

In the light projecting device 1 of the present embodiment, since the plurality of light shielding plates 62 are provided in front of the parabolic reflection surface 24A, the entry of external light into the parabolic reflection surface 24A is suppressed, and the external light is blocked by the illuminance sensor 70A. It is possible to detect illumination light with reduced influence.

The above-described embodiment is merely an example of one aspect of the present invention, and can be arbitrarily modified and applied without departing from the gist of the present invention.

(Modification 1)
In the laser beam shielding unit 60, the annular shape of the shielding plate 62 is not limited to a complete circular ring, and may be an annular shape appropriately including linear portions and corner portions in the main direction. For example, as shown in FIG. 15, a laser beam shielding unit 160 having a honeycomb structure 161 may be configured instead of the plurality of shielding plates 62 arranged concentrically. The honeycomb structure 161 includes a large number of tubular bodies 163 (regular hexagons in cross section in this modification) extending parallel to the optical axis K on the same plane (on the open end face 29 of the parabolic reflecting surface 24A in this modification). It is a structure in which the side surfaces 163A of the cylindrical bodies 163 are arranged without gaps and antireflection treatment is applied. In the honeycomb structure 161, the side surfaces 163A of the cylindrical bodies 163 located at approximately the same distance T from the optical axis K are connected to form an annular light shielding plate surrounding the optical axis K. As shown in FIG.

As a result, the laser light shielding unit 160 of this modified example allows the illumination light to pass through, while the laser light shielding unit 160 of the present modification allows the illumination light to pass through, regardless of the positions of the laser light source units 30 around the optical axis K. Therefore, the leakage light component of the laser light from each laser light source unit 30 can be shielded by the side surface 163A of each cylindrical body 163.
In addition, compared to the light shielding plate 62 of the laser light shielding unit 60 of the above-described embodiment, the honeycomb structure 161 can obtain a predetermined rigidity even if the thickness of the side surface 163A is reduced, so that more illumination light can be absorbed. can pass.

(Modification 2)
In the above-described embodiment, as shown in FIG. 16, one illuminance sensor substrate 70 is arranged between each of the two parabolic reflection surfaces 24A. By forming a pinhole 74 at a position where illumination light is incident on the illuminance sensor 70A (for example, on a straight line connecting the illuminance sensor 70A and the phosphor 22), one illuminance sensor 70A can be used for each parabolic reflection surface 24A. The amount of illumination light incident from the pinhole 74 may be detected.
According to this modification, one illuminance sensor 70A detects the amount of illumination light from a plurality of parabolic reflection surfaces 24A, so the number of parts can be reduced and cost can be reduced.

(Modification 3)
In the above-described embodiment, the configuration in which the illumination sensor 70A detects illumination light (mixed light of blue laser light and yellow fluorescence) is exemplified. An optical filter may be provided to cut the component. As a result, for example, when the amount of fluorescent light is reduced due to damage or detachment of the phosphor 22, even if the laser light component passes through the pinhole 74 toward the illuminance sensor 70A, regardless of the light amount of the laser light component, Decrease in fluorescence light intensity can be accurately detected.

(Modification 4)
In the above-described embodiment, the parabolic reflection surface 24A is provided with the pinhole 74 as a light passage through which the illumination light passes from the front side to the back side. , and open-shaped holes can be used.

(Other modifications)
The present invention can be applied not only to a light projecting device but also to any lighting equipment.
Further, in the above-described embodiments, horizontal and vertical directions, various numerical values, and shapes are consciously intended to represent the peripheral ranges of these directions, numerical values, and approximate shapes, unless otherwise specified. However, it includes the peripheral range and approximate shape (so-called equivalent range) as long as the same effect is achieved and the numerical value does not deviate from the critical significance.

1 floodlight device (lighting equipment)
20 Light source unit 22 Phosphor 24 Reflector 24A Parabolic reflecting surface (first reflecting surface)
27 Phosphor holder 27A Planar reflecting surface (second reflecting surface)
28 Phosphor holding bar (holding member)
29 opening end face 30 laser light source unit 36 laser diode (laser light source)
46 through hole 60, 160 laser light shielding unit 62 light shielding plate 64 support plate 65 light shielding surface 68 notch recess 69 wall surface 161 honeycomb structure 163 cylindrical body 163A side surface D arrangement interval H height K optical axis f focus α incident angle

Claims (6)

a first reflecting surface for collimating light from the focal point;
a phosphor provided on a second reflecting surface positioned at the focal point of the first reflecting surface;
a laser light source that irradiates the phosphor with a laser beam from a direction oblique to the optical axis of the first reflecting surface to emit fluorescence from the phosphor;
A lighting fixture that illuminates with parallel light obtained by collimating the laser light reflected by the second reflecting surface and the fluorescence emitted from the phosphor by the first reflecting surface,
a laser light shielding unit having a plurality of light shielding plates fixedly arranged in parallel with the optical axis of the first reflecting surface, the light shielding plate shielding a leaked light component of the laser light that has deviated from the phosphor;
a plurality of the laser light sources are arranged around the optical axis, and each of the light shielding plates is formed in an annular shape surrounding the optical axis and arranged coaxially and concentrically with the optical axis;
A lighting fixture, wherein the height _Hn of each of the light shielding plates in the direction of the optical axis and the arrangement interval Dn _satisfy the following equation .
H _n ≥ D _n tan (90-α _n-1 )
However, n represents the order of the light shielding plates counted from the optical axis, and α _n is the incident angle with respect to the optical axis of the leaked light component incident on the n-th light shielding plate. 2. The luminaire according to claim 1 , wherein the diameter of the outermost light blocking plate exceeds 50% of the diameter of the open end face of the first reflecting surface. 3. The luminaire according to claim 1 , further comprising a wall surface located outside said first reflecting surface for shielding leaked light components passing through said laser beam shielding unit. 4. A luminaire according to any one of claims 1 to 3 , characterized in that the heights _Hn of each of said gobos are equal. 5. The lighting fixture according to any one of claims 1 to 4 , wherein each of said light shielding plates has high thermal conductivity and engages with a holding member holding said phosphor. 6. The lighting fixture according to any one of claims 1 to 5 , wherein each of said light shielding plates is subjected to antireflection treatment.

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