JP2020013659A - Lighting device and lighting device unit - Google Patents

Abstract

To improve exterior appearance of a lighting device.SOLUTION: A lighting device 10 includes: a plurality of light sources 20 each emitting light L; and a diffractive optical element 40 for diffracting and orienting light L emitted from the light sources 20 toward a region to be irradiated. Each incident region 41 on the diffractive optical element 40 to which each light source 20 emits light has a length in the first direction d1 thereof that is larger than a length in a second length d2 intersecting with the first direction d1. The light sources 20 are arranged along the first direction d1.SELECTED DRAWING: Figure 2

Description

  The present disclosure relates to a lighting device and a lighting device unit including the lighting device.

  For example, as disclosed in Patent Document 1, an illumination device including a light source and a hologram element is known. In the illuminating device disclosed in Patent Literature 1, a hologram element diffracts light from a light source to illuminate a road surface in a desired pattern. In the illumination device disclosed in Patent Literature 1, laser light generated by a light source is diffracted by a hologram element.

JP-A-2015-132707

  By the way, it is desired to improve the appearance of a lighting device and the appearance of an article into which the lighting device is incorporated.

  Embodiments of the present disclosure have been made in consideration of the above points, and have as its object to improve the appearance of a lighting device or the appearance of an article into which the lighting device is incorporated.

The lighting device according to an embodiment of the present disclosure includes:
A plurality of light sources each emitting light,
A diffractive optical element that diffracts light emitted from the plurality of light sources and directs the light toward the illuminated area,
Each incident area of the light emitted from each light source on the diffractive optical element has a length in a first direction larger than a length in a second direction crossing the first direction,
The plurality of light sources are arranged along the first direction.

In the lighting device according to an embodiment of the present disclosure,
The diffractive optical element has an incident surface on which the light is incident,
The length of the incident surface in the first direction may be greater than the length of the incident surface in the second direction.

In the lighting device according to an embodiment of the present disclosure,
The light source may be various semiconductor lasers, solid-state lasers, or SHG lasers.

In the lighting device according to an embodiment of the present disclosure,
The diffusion angle of the light emitted from the light source in the first direction may be larger than the diffusion angle in the second direction.

In the lighting device according to an embodiment of the present disclosure,
A collimator lens may be provided between each light source along the optical path of the light and the diffractive optical element to make the light emitted from the light source closer to a parallel light flux.

In the lighting device according to an embodiment of the present disclosure,
Light from the light source may be directly incident on the collimating lens.

Alternatively, the lighting device according to an embodiment of the present disclosure includes:
A plurality of light sources each emitting light,
A diffractive optical element that diffracts light emitted from the plurality of light sources and directs the light toward the illuminated area,
Each of the plurality of incident regions on the diffractive optical element of the light emitted from the plurality of light sources is elongated,
The plurality of light sources are arranged on a straight line or on a curve,
The longitudinal direction of each incident region is along the direction in which the straight line or the curved line extends in the light source corresponding to the incident region.

Alternatively, the lighting device unit according to an embodiment of the present disclosure includes:
A first lighting device, which is the lighting device described above,
A second lighting device having a light source for emitting light.

The lighting device unit according to an embodiment of the present disclosure includes:
The image processing apparatus may further include a control device that adjusts the radiance of light emitted from the light source of the first lighting device according to the radiance of light emitted from the light source of the second lighting device.

  In this case, the control device controls the first illuminance so that the radiance of light emitted from the light source of the first lighting device is smaller than the radiance of light emitted from the light source of the second lighting device. The radiance of light emitted from the light source of the lighting device may be adjusted.

Alternatively, the lighting device unit according to an embodiment of the present disclosure includes:
The image processing apparatus may further include a control device that adjusts the radiance of light emitted from the light source of the second lighting device according to the radiance of light emitted from the light source of the first lighting device.

  In this case, the control device controls the second illuminance so that the radiance of light emitted from the light source of the first lighting device is smaller than the radiance of light emitted from the light source of the second lighting device. The radiance of light emitted from the light source of the lighting device may be adjusted.

  In the lighting device unit according to the embodiment of the present disclosure, the light source of the second lighting device may emit laser light. Alternatively, the light source of the second lighting device may include at least one of a halogen lamp, an LED, a HID lamp, a xenon lamp, a sodium lamp, a metal halide lamp, and a mercury lamp.

  Further, the lighting device unit according to an embodiment of the present disclosure may further include a housing that houses the first lighting device and the second lighting device. Alternatively, the lighting device unit may further include a housing that houses the first lighting device, the second lighting device, and the control device.

  According to the lighting device of the embodiment of the present disclosure, the appearance of the lighting device or the appearance of an article into which the lighting device is incorporated can be improved. According to the lighting device unit of the embodiment of the present disclosure, the appearance of the lighting device unit can be improved.

FIG. 1 is a diagram for describing an embodiment according to the present disclosure, and is a perspective view illustrating an appearance of a lighting device. FIG. 2 is a perspective view illustrating a configuration of the lighting device. FIG. 3 is a perspective view showing a general semiconductor laser. FIG. 4A is a plan view showing a pattern formed on the lighting device shown in FIG. FIG. 4B is a plan view illustrating a modification of the pattern formed on the lighting device. FIG. 4C is a plan view showing another modification of the pattern formed on the lighting device. FIG. 4D is a plan view showing another modification of the pattern formed on the lighting device. FIG. 4E is a plan view showing another modification of the pattern formed on the lighting device. FIG. 5 is a diagram for describing another embodiment according to the present disclosure, and is a perspective view illustrating an appearance of a lighting device unit including the lighting device illustrated in FIG. 2. FIG. 6 is a schematic diagram showing the configuration of the lighting device unit shown in FIG. FIG. 7 is a plan view showing a pattern formed on the lighting device unit shown in FIG. FIG. 8 is a view corresponding to FIG. 7, and is a view for explaining a modification of the lighting device unit shown in FIG.

<First embodiment>
Hereinafter, a first embodiment of the present disclosure will be described with reference to the drawings. In the drawings attached to the present specification, the scale and the size ratio in the vertical and horizontal directions are appropriately changed and exaggerated for the sake of convenience of illustration and understanding.

  Further, in the present specification, for specifying the shape and geometric conditions and the degree thereof, for example, terms such as "parallel", "orthogonal", "identical", and values of length and angle are strictly described. Without being limited to any meaning, it should be interpreted to include a range in which similar functions can be expected.

  FIG. 1 is a perspective view showing the appearance of the lighting device 10. FIG. 2 is a perspective view schematically illustrating a schematic configuration of the lighting device 10. FIG. 3 is a perspective view of a semiconductor laser generally used as a light source of the illumination device 10. FIG. 4A is a plan view showing a pattern formed on the lighting device 10 shown in FIG.

  The lighting device 10 shown in FIG. 1 is housed in the housing 1 and installed on the ground or the floor. The illumination device 10 illuminates the illuminated area Z using the installation surface as the projection surface S. More specifically, lighting device 10 illuminates illuminated area Z via light emitting window 2 provided in housing 1. In the illustrated example, the illumination device 10 illuminates the illuminated area Z in an arrow pattern, but is not limited thereto. The lighting device 10 may illuminate the illuminated area Z with a figure or character pattern other than an arrow. Such a lighting device 10 can be used not only as an installed lighting device stored in a housing 1 as shown in FIG. 1, but also for various moving objects, that is, automobiles, bicycles, ships, airplanes, and trains. Application to various lighting devices used is also possible. Further, it can be used as a part of the above-described lighting device or information display lamp.

  As shown in FIG. 2, the illumination device 10 includes a plurality of light sources 20 each emitting light L, a diffractive optical element 40 that diffracts the light L emitted from the plurality of light sources and directs the light L toward the illumination area Z, including. Further, the illumination device 10 has a collimating lens 30 that collimates the light L emitted from the plurality of light sources 20. The collimating lens 30 and the diffractive optical element 40 are arranged in this order along the optical path of the light source light L from the light source 20, and act on the light source light L in this order.

  In the illustrated example, each light source 20 is a laser light source. The laser light projected from the laser light source has excellent straightness and is suitable as light for illuminating the illuminated area Z with high accuracy. The plurality of laser light sources 20 may be provided independently, or may be a light source module in which the plurality of laser light sources 20 are arranged on a common substrate. The plurality of laser light sources 20 are, for example, six laser light sources 20a, 20b, 20c, 20d, 20e, and 20f that oscillate light of the same color, for example, green emission wavelength range.

  However, the present invention is not limited to the above example, and the plurality of laser light sources 20 may oscillate light in a plurality of colors, for example, red, green, and blue emission wavelength ranges. For example, the laser light sources 20a and 20b oscillate light in a red emission wavelength range, the laser light sources 20c and 20d oscillate light in a green emission wavelength range, and the laser light sources 20e and 20f emit blue light. It may oscillate light in the emission wavelength range. In this case, it is possible to illuminate the illuminated area Z with illumination light of a desired color by superposing the three colors of laser light L emitted from the plurality of laser light sources 20. By adjusting the radiant flux [unit: W] of the laser light L emitted from the plurality of laser light sources 20, the color of the illumination light can be adjusted. In addition, since a plurality of laser light sources 20 are provided for each emission wavelength range, the emission intensity can be increased. The number of the plurality of laser light sources 20 is not limited to six, and may be two or more.

  In the illustrated example, the plurality of light sources 20 are edge-emitting semiconductor lasers, as shown in FIG. The semiconductor laser emits laser light L as diffused light having anisotropic diffusion angle. More specifically, the laser beam L emitted by the semiconductor laser emits a diffusion angle θ1 in the first direction d1 along the stacking direction of the semiconductor stacked body 23 including the active layer 22 disposed between the electrodes 21 of the semiconductor laser. And a diffusion angle θ2 in a second direction d2 perpendicular to the first direction d1. In the illustrated example, the diffusion angle θ1 in the first direction d1 is larger than the diffusion angle θ2 in the second direction d2. The light L emitted from each light source 20 is diffused, and becomes a light whose cross section perpendicular to the optical axis Lx is elliptical. More specifically, the cross-section becomes elliptical light having a longitudinal direction along the first direction d1 and a lateral direction along the second direction d2. The light source that emits light whose cross section perpendicular to the optical axis Lx is elliptical is not limited to an edge-emitting semiconductor laser, but various semiconductor lasers, solid-state lasers, SHG (Second Harmonic Generation) lasers, and the like are also used. It is possible.

  Next, the collimating lens 30 will be described. The collimating lens 30 shapes the diffused light L emitted from the light source 20 so as to approach a parallel light flux. In the illustrated example, the illumination device 10 has a plurality of collimating lenses. More specifically, the lighting device 10 has six collimating lenses 30a, 30b, 30c, 30d, 30e, and 30f corresponding to each of the six light sources 20a to 20f. Each of the collimating lenses 30a to 30f collimates the laser light L emitted from the corresponding laser light source 20a to 20f.

  In the illustrated example, no other optical system is arranged between the light sources 20a to 20f and the collimating lenses 30a to 30f along the optical path of the light from the light sources 20a to 20f. Light is directly incident on the collimating lenses 30a to 30f. Accordingly, the number of components constituting the lighting device 10 can be reduced, and the lighting device 10 can be reduced in weight.

  Incidentally, the light L collimated by each collimating lens 30 enters the diffractive optical element 40. Then, the light L diffracted by the diffractive optical element 40 enters the illuminated area Z via the light projecting window 2. Here, when a light source that irradiates a laser beam is used, the illuminated area Z can be brightly illuminated, but when the illuminating light from the illuminating device 10 is directly viewed, there is a possibility that human eyes may be adversely affected. Therefore, in consideration of safety, a large incident area (spot area) 41 of the light source light L to the diffractive optical element 40 is secured, and the power density of the light source light L at each position on the diffractive optical element 40 is reduced. Is preferred.

  In consideration of such circumstances, the collimator lens 30 is arranged at a position sufficiently distant from the laser light source 20, and the light source light L sufficiently diffused is incident on the collimator lens 30. Accordingly, the elliptical diffused light L whose cross section perpendicular to the optical axis Lx is elongated is incident on the collimator lens 30, and the collimator lens 30 collimates the elliptical diffused light L and directs it toward the diffractive optical element 40.

  Of course, by arranging a diffusion optical system for expanding the light from the light source 20 and widening the optical path width between the light source 20 and the collimating lens 30 along the optical path of the light from the light source 20, the light is sufficiently diffused. The light source light L may enter the collimator lens 30. In this case, the distance between the light source 20 and the collimating lens 30 can be reduced, and the size of the illumination device 10 can be reduced.

  Next, the diffractive optical element 40 will be described. The diffractive optical element 40 is an element that exerts a diffractive action on the light L emitted from the light source 20. The illustrated diffractive optical element 40 diffracts the light L from the light source 20 and directs the diffracted light L to the illuminated area Z. Therefore, the illuminated area Z is illuminated by the diffracted light L from the diffractive optical element 40.

  In the illustrated example, the illumination device 10 has a plurality of diffractive optical elements 40. More specifically, the illumination device 10 has six diffractive optical elements 40a, 40b, 40c, 40d, 40e, and 40f. Each of the diffractive optical elements 40a to 40f is provided corresponding to each of the laser light sources 20a to 20f. According to this example, even when the laser light sources 20a to 20f oscillate laser lights in different wavelength ranges, each of the diffractive optical elements 40a to 40f converts the laser light in different wavelength ranges generated by the corresponding laser light source to high. It becomes possible to diffract with efficiency.

  The light L emitted from each of the plurality of laser light sources 20a to 20f is diffracted by the diffractive optical elements 40a to 40f corresponding to each of the laser light sources, and then illuminates an area at least partially overlapping. Particularly, in the illustrated example, the light L emitted from each of the plurality of laser light sources 20a to 20f is diffracted by the diffractive optical elements 40a to 40f corresponding to each laser light source, and then illuminates the same illuminated area Z. . More precisely, the diffracted light L diffracted by each of the diffractive optical elements 40a to 40f illuminates only the entire region to be illuminated Z. The diffracted light L from each of the diffractive optical elements 40a to 40f illuminates only the illuminated area Z over the entire area thereof, thereby effectively reducing the uneven brightness and the uneven color in the illuminated area Z. Can be less noticeable.

  As an example, each diffractive optical element 40 is configured as a hologram recording medium on which an interference fringe pattern is recorded. By variously adjusting the interference fringe pattern, it is possible to control the traveling direction of the light L diffracted by each diffractive optical element 40, in other words, the traveling direction of the light L diffused by each diffractive optical element 40. .

  Each diffractive optical element 40 can be manufactured using, for example, scattered light from a real scattering plate as object light. More specifically, when the hologram photosensitive material, which is the base of the diffractive optical element 40, is irradiated with reference light and object light composed of coherent light having coherence with each other, interference fringes due to interference of these lights cause hologram photosensitive material. And the diffractive optical element 40 is manufactured. As the reference light, laser light that is coherent light is used, and as the object light, for example, scattered light from an inexpensively available isotropic scattering plate is used.

  By irradiating the laser light toward the diffractive optical element 40 so as to travel in the opposite direction along the optical path of the reference light used in manufacturing the diffractive optical element 40, the object light used in manufacturing the diffractive optical element 40 is A reproduced image of the scattering plate is generated at the position of the original scattering plate. If the scattering plate that is the source of the object light used in manufacturing the diffractive optical element 40 has uniform surface scattering, the reproduced image of the scattering plate obtained by the diffractive optical element 40 also has uniform surface illumination. The region where the reproduced image of the scattering plate is generated can be set as the illuminated region Z.

  In addition, the complex interference fringe pattern formed on each diffractive optical element 40 is reproduced by using the planned wavelength and incident direction of the reproduction illumination light instead of using the actual object light and the reference light. It is possible to design using a computer based on the shape and position of the power image. The diffractive optical element 40 obtained in this manner is also called a computer generated hologram (CGH). For example, when the illuminating device 10 is used to illuminate an illuminated area Z having a certain size on the ground or water surface, it is difficult to generate object light, and the computer-generated hologram is used as a diffractive optical element. Preferably, it is used as 40.

  Further, Fourier transform holograms having the same diffusion angle characteristic at each point on each diffractive optical element 40 may be formed by computer synthesis. Further, an optical member such as a lens may be provided downstream of the diffractive optical element 40 so that the diffracted light is adjusted so as to be incident on the entire illuminated area Z.

  A specific form of the diffractive optical element 40 may be a volume hologram recording medium using a photopolymer, or may be a volume hologram recording medium of a type that records using a photosensitive medium containing a silver salt material, A relief type (emboss type) hologram recording medium may be used. Further, the diffractive optical element 40 may be a transmission type or a reflection type.

  In the illustrated example, no other optical system is disposed between the collimating lens 30 and the diffractive optical element 40 along the optical path of the light from the light source 20, and the light shaped by the collimating lens 30 is , And directly enter the diffractive optical element 40. Thereby, the lighting device 10 can be reduced in weight and size. Of course, another optical system may be arranged between the collimator lens 30 and the diffractive optical element 40 along the optical path of the light from the light source 20. For example, an afocal optical system may be arranged between the collimator lens 30 and the diffractive optical element 40. In this case, the optical path width (beam diameter) or the parallelism of the light incident on the diffractive optical element 40 can be adjusted more appropriately.

  In the illustrated example, no other optical system is disposed between the diffractive optical element 40 along the optical path of the light from the light source 20 and the light projecting window 2 or the illuminated area Z. The light diffracted by the optical element 40 passes through the light projecting window 2 and directly enters the illuminated area Z. Thereby, the lighting device 10 can be reduced in weight and size. Of course, another optical system may be arranged between the diffractive optical element 40 along the optical path of the light from the light source 20 and the light projecting window 2 or the illuminated area Z. For example, an optical system for refracting the light diffracted by the diffractive optical element 40, for example, a prism may be arranged between the diffractive optical element 40 and the light projecting window 2 or the illumination area Z. In this case, the direction of the zero-order light of the light emitted from the diffractive optical element 40 can be changed or adjusted. Therefore, when it is necessary to diffract light incident on the diffractive optical element 40 at a large diffraction angle with respect to the optical axis of the light in order to illuminate the illumination target area Z, the light diffracted by the diffractive optical element 40 is It can be further refracted and directed to the illuminated area Z. Such an optical system can direct light diffracted by the diffractive optical element 40 with high diffraction efficiency to the illuminated area Z with high efficiency.

  As described above, the light L whose section perpendicular to the optical axis Lx is elongated in the first direction d1 enters each diffractive optical element 40. More specifically, elliptical light L having a longitudinal direction in the first direction d1 and a lateral direction in the second direction d2 enters. Therefore, the incident area (spot area) 41 of the laser beam L on the incident surface of each diffractive optical element 40 also extends in the first direction d1 in an elongated shape and has an elliptical shape having a shorter direction in the second direction. In the illustrated example, the incident surface of each diffractive optical element 40 has a length in the first direction d1 corresponding to the incident area 41 elongated in the first direction d1 of the diffractive optical element 40 and has a length in the second direction. It has an elongated shape larger than the length of d2. Since the incident surface of the diffractive optical element 40 is elongated in accordance with the shape of the incident area 41, the area of the incident surface of the diffractive optical element 40 can be reduced, and the size of the diffractive optical element 40 can be reduced. can do. As a result, the size of the lighting device 10 can be reduced. Here, in the illustrated example, since the incident surface of the diffractive optical element 40 has an elongated shape elongated in the first direction d1, each incident light on the diffractive optical element 40 of the light L emitted from each light source 20 is provided. The region 41 is elongated in the longitudinal direction of the diffractive optical element 40.

  As described above, the incident area 41 of the light L on each diffractive optical element 40 is elongated in the first direction d1 and has an elliptical shape having a short direction in the second direction d2. Correspondingly, the light L emitted from the plurality of light sources 20 is diffracted by a person observing the light projecting window 2 from outside the housing 1 in which the lighting device 10 is stored, or by way of the light projecting window 2. A person observing the optical element 40 recognizes the plurality of lights L elongated in the first direction d1. In the illustrated illuminating device 10, the plurality of elongated light L is arranged to form a linear pattern on the light projecting window 2 or the diffractive optical element 40.

  More specifically, as shown in FIG. 4A, a plurality of elongated lights L emitted from a plurality of light sources 20 are arranged along the longitudinal direction d1 to form a linear pattern on the light projecting window 2. are doing. Thereby, a thinner line-shaped pattern can be formed in the light projecting window 2 as compared with the case where a plurality of elongated lights L are arranged along the short direction d2. In the example shown in FIG. 4A, a plurality of elongated light L is arranged along an edge of the light projecting window 2 extending in the vertical direction.

  In order to form the pattern shown in FIG. 4A, the directions and arrangements of the plurality of light sources 20 are determined as follows. First, as described above, each light source 20 emits the diffused light L whose diffusion angle θ1 in the first direction d1 is larger than the diffusion angle θ2 in the second direction d2 orthogonal to the first direction d1. Therefore, the direction of each light source 20 is determined such that the first direction d1 of the light L emitted from each light source 20 is along the vertical direction. That is, in the illustrated example, the direction of each light source 20 is determined so that the stacking direction of the semiconductor stacked body 23 of the semiconductor laser illustrated in FIG. 3 is along the vertical direction. Thereby, the corresponding incident area 41 of the diffractive optical element 40 has a longitudinal direction in the vertical direction. Further, as shown in FIG. 2, the plurality of light sources 20 are arranged in a vertical direction. Thereby, the incidence areas 41 of the plurality of diffractive optical elements 40 are arranged in the vertical direction. Therefore, in the diffractive optical element 40, the plurality of incident regions 41 each extending in the vertical direction are aligned in the vertical direction. As a result, the light L emitted from the plurality of light sources 20 of the illumination device 10 forms an elongated linear pattern extending in the vertical direction on the diffractive optical element 40 and further on the light projecting window 2. Note that, in accordance with the orientation and arrangement of the light source 20, the longitudinal direction of each diffractive optical element 40 is along the vertical direction, and the plurality of diffractive optical elements 40 are aligned along the vertical direction. I have.

  Note that the above-described lighting device 10 can be used to form a horizontal pattern extending in the horizontal direction shown in FIG. 4B. In this case, the orientation and arrangement of the plurality of light sources 20 are determined as follows. First, the direction of each light source 20 is determined such that the first direction d1 of the light L emitted from each light source 20 is along the horizontal direction. That is, in the illustrated example, the orientation of each light source 20 is determined such that the lamination direction of the semiconductor laminate 23 of the semiconductor laser shown in FIG. 3 is along the horizontal direction. Thereby, the corresponding incident area 41 of the diffractive optical element 40 has a longitudinal direction in the horizontal direction. Further, the plurality of light sources 20 are arranged in a horizontal direction. Thereby, the incidence areas 41 of the plurality of diffractive optical elements 40 are arranged in the horizontal direction. Therefore, in the diffractive optical element 40, the plurality of incident areas 41 each extending in the horizontal direction are arranged in the horizontal direction. As a result, the light L emitted from the plurality of light sources 20 of the illumination device 10 forms an elongated linear pattern extending in the horizontal direction on the diffractive optical element 40 and further on the light projecting window 2. In this case, the longitudinal direction of each diffractive optical element 40 extends along the horizontal direction, and the plurality of diffractive optical elements 40 extend along the horizontal direction in accordance with the orientation and arrangement of the light source 20 described above. Are aligned.

  Furthermore, a curved pattern as shown in FIG. 4C can be formed using the above-described lighting device 10. In this case, the directions and arrangement of the plurality of light sources 20 are determined as follows. First, the plurality of light sources 20 are arranged along a curved pattern to be formed. In the example shown in FIG. 4C, the plurality of light sources 20 are arranged along a circular pattern. Further, the direction of each light source 20 is determined such that the first direction d1 of the light L emitted from each light source 20 is along the bending direction at the corresponding point of the pattern. That is, in the illustrated example, the direction of each light source 20 is determined so that the stacking direction of the semiconductor stacked body 23 of the semiconductor laser shown in FIG. In the example shown in FIG. 4C, the direction of each light source 20 is determined such that the first direction d1 is along the circumferential direction of the circle. That is, the direction of each light source 20 is determined such that the lamination direction of the semiconductor laminate 23 is along the circumferential direction of the circle. Accordingly, in the diffractive optical element 40, each of the plurality of incident regions 41 arranged along the pattern is elongated in the bending direction at a corresponding point of the pattern. As a result, a curved pattern can be formed on the diffractive optical element 40 and further on the light projecting window 2. In the example shown in FIG. 4C, in the diffractive optical element 40, each of the plurality of incident regions 41 arranged along the circular pattern is elongated in the circumferential direction of the circle. As a result, a circular pattern as shown in FIG. 4C can be formed on the diffractive optical element 40 and further on the light projecting window 2. In this case, the plurality of diffractive optical elements 40 are arranged along the above-mentioned curved pattern corresponding to the orientation and arrangement of the light source 20 as described above. Are along the direction of curvature at corresponding points in the pattern. In the example shown in FIG. 4C, the plurality of diffractive optical elements 40 are arranged along a circular pattern, and the longitudinal direction of each diffractive optical element 40 is along the circumferential direction of the circle.

  In other words, the illumination device 10 includes a plurality of light sources 20 each of which emits light, and a diffractive optical element 40 that diffracts the light L emitted from the plurality of light sources 20 and directs the light L to the illuminated area Z. Each of the plurality of incident areas 41 of the light emitted from the plurality of light sources 20 on the diffractive optical element 40 has an elongated shape. The plurality of light sources 20 are arranged on a straight line or a curved line, and the longitudinal direction of each incident region 41 is along the direction in which the straight line or the curved line of the light source 20 corresponding to the incident region 41 extends. . Thereby, a linear or curved line pattern can be formed on the light projecting window 2 or the diffractive optical element 40.

  Note that a pattern in which a plurality of linear patterns shown in FIG. 4D are juxtaposed or a pattern in which a plurality of linear patterns shown in FIG. It may be formed.

  The color of each point of the above-described linear pattern is a color corresponding to the wavelength range of the light L emitted from the light source 20 corresponding to each point. Therefore, when the plurality of light sources 20 emit the light L in the same color wavelength range, the pattern formed on the light projecting window 2 or the diffractive optical element 40 is represented by a single color. When the plurality of light sources 20 emit light L in a plurality of wavelength ranges different from each other, the pattern formed on the light projecting window 2 or the diffractive optical element 40 is represented by a plurality of colors corresponding to the plurality of wavelength ranges. Is done. For example, when the light sources 20a and 20b emit light L in a red wavelength range, the light sources 20c and 20d emit light L in a green wavelength range, and the light sources 20e and 20f emit light L in a blue wavelength range. The incident area 41 on the diffractive optical elements 40a and 40b becomes red, the incident area 41 on the diffractive optical elements 40c and 40d becomes green, and the incident area 41 on the diffractive optical elements 40e and 40f becomes blue. For this reason, in the pattern formed on the light projecting window 2 or the diffractive optical element 40, a portion corresponding to the light sources 20a and 20b is represented in red, a portion corresponding to the light sources 20c and 20d is represented in green, and the light sources 20e and 20d. The portion corresponding to 20f is displayed in blue.

  Next, the operation of the illumination device 10 having the above-described configuration will be described.

  The laser light L emitted from each laser light source 20 first enters the corresponding collimating lens 30. Here, the laser light L emitted from the laser light source 20 is diffused light having different diffusion angles θ1 and θ2 in the first direction d1 and the second direction d2 orthogonal to each other. In the illustrated example, the diffusion angle θ1 in the first direction d1 is larger than the diffusion angle θ2 in the second direction d2. As described above, the collimator lens 30 is arranged at a position sufficiently distant from the light source 20 in consideration of safety. Thereby, the laser light L sufficiently diffused enters the collimator lens 30. For this reason, the laser beam L incident on the collimator lens 30 has an elliptical cross section perpendicular to the optical axis Lx elongated in the first direction d1. The collimating lens 30 collimates the elliptical divergent light beam L.

  Next, the laser beam L collimated by the collimating lens 30 travels to the diffractive optical element 40. The diffractive optical element 40 records interference fringes corresponding to the center wavelength of the laser light L emitted from the laser light source 20, and can diffract the laser light L incident from a certain direction in a desired direction with high efficiency. it can. In the illustrated example, each diffractive optical element 40 diffuses the entire illuminated area Z located on the projection surface S such as the ground or the floor.

  As a result, the illuminated area Z can be illuminated by superimposing the laser light L emitted from the laser light sources 20a to 20f. Therefore, when the plurality of laser light sources 20 emit light in a plurality of wavelength ranges, the illumination device 10 illuminates the illuminated area Z with a color that cannot be reproduced only by the laser light emitted from a single laser light source. be able to. Here, the illumination color is adjusted by appropriately adjusting the radiant flux of the laser light L emitted from each laser light source 20, in other words, adjusting the output of each laser light source to adjust the radiant flux of the laser light L emitted. By adjusting the color, a desired color can be obtained.

  Meanwhile, as described above, the elliptical light L extending along the first direction d1 enters the collimator lens 30. For this reason, the incident area 41 of the laser light L incident on the diffractive optical element 40 from the collimating lens 30 also extends elongated along the first direction d1. The plurality of laser light sources 20 are arranged along the longitudinal direction (first direction d1). For this reason, the plurality of incident regions 41 of the laser light emitted from the plurality of light sources 20 on the diffractive optical element 40 are aligned along the longitudinal direction d1 of the incident region, and thus along the longitudinal direction of the diffractive optical element 40. . As a result, a linear pattern extending along the first direction d1 is formed on the diffractive optical element 40 and the light projecting window 2.

  In the above-described first embodiment described above, the illumination device 10 includes the plurality of light sources 20 each emitting the light L, and the illuminated area Z by diffracting the light L emitted from the plurality of light sources 20. And a diffractive optical element 40 directed toward Each incident area 41 of the light emitted from each light source 20 on the diffractive optical element 40 has a length in the first direction d1 greater than a length in a second direction d2 intersecting the first direction d1. The light sources 20 are arranged along the first direction d1. This lighting device 10 can illuminate the illuminated area Z. Further, in the illumination device 10, the light incident regions 41 on the diffractive optical element 40 are arranged along the longitudinal direction of each of the incident regions 41. The incident areas 41 arranged along each longitudinal direction in this manner can be used to improve the appearance of the lighting device 10 or the appearance of an article in which the lighting device 10 is incorporated. For example, the plurality of incident regions 41 can form a thin line-shaped pattern on the diffractive optical element 40 of the lighting device 10 or on the surface of an article in which the lighting device 10 is incorporated.

  In the first embodiment, the diffractive optical element 40 has an incident surface on which the light L is incident, and the length of the incident surface in the first direction d1 is longer than the length of the incident surface in the second direction d2. Is also big. In this case, the incident surface of the diffractive optical element 40 has a shape corresponding to the shape of each incident area 41 on the diffractive optical element 40 of the light L emitted from each light source 20. Thus, the area of the incident surface of the diffractive optical element 40 can be reduced, and the size of the diffractive optical element 40 can be reduced. As a result, the size of the lighting device 10 can be reduced.

  Specifically, the light source 20 is various semiconductor lasers including an edge-emitting semiconductor laser, a solid-state laser, or an SHG laser. The diffusion angle of the light emitted from the light source 20 in the first direction d1 is larger than the diffusion angle in the second direction d2.

  In the first embodiment, the collimating lens 30 is provided between each light source 20 and the diffractive optical element 40 along the optical path of the light to make the light L emitted from the light source 20 closer to a parallel light flux. Thus, the collimated light L is incident on the diffractive optical element 40, so that the light L can be diffracted by the diffractive optical element 40 in a desired direction with high accuracy.

  In the first embodiment described above, the light L from the light source 20 is directly incident on the collimator lens 30. In this case, the lighting device 10 can be reduced in weight.

  Alternatively, in the above-described first embodiment, the illumination device 10 includes a plurality of light sources 20 each of which emits light, and a diffractive optic that diffracts the light L emitted from the plurality of light sources 20 and directs the light L toward the illumination target area Z. Each of the plurality of incident regions 41 of the light L emitted from the plurality of light sources 20 on the diffractive optical element 40 has an elongated shape. The plurality of light sources 20 are arranged on a straight line or a curve, and the longitudinal direction of each incident region 41 is along the direction in which the straight line or the curved line of the light source 20 corresponding to the incident region 41 extends. . This lighting device 10 can illuminate the illuminated area Z. Further, in the illumination device 10, the plurality of incident regions 41 extend continuously on a straight line or a curved line to form a linear pattern of the straight line or the curved line. The linear pattern can be used to improve the appearance of the lighting device 10 or the appearance of an article in which the lighting device 10 is incorporated.

<Second embodiment>
Next, a second embodiment of the present disclosure will be described with reference to FIGS. FIG. 5 is a perspective view showing the lighting device unit 100. FIG. 6 is a schematic diagram illustrating a configuration of the lighting device unit 100. FIG. 7 is a plan view showing a pattern of light observed on the lighting device unit 100 shown in FIGS. 5 and 6.

  As illustrated in FIGS. 5 and 6, the lighting device unit 100 includes the lighting device 10 illustrated in FIG. 2 and the second lighting device 200 as the first lighting device. The second lighting device 200 has a light source 220 that emits light. In the illustrated example, the light source 220 of the second lighting device 200 is a laser light source that emits laser light, but is not limited thereto. For example, the light source 220 of the second lighting device 200 includes any one of a halogen lamp, an LED (Light Emitting Diode), an HID lamp (High-Intensity Discharge lamp), a xenon lamp, a sodium lamp, a metal halide lamp, and a mercury lamp. There may be. The first lighting device 10 and the second lighting device 200 are housed in the housing 101 and installed on an installation surface S such as the ground or a floor. Then, the first lighting device 10 illuminates the first illuminated area Z1 on the installation surface S in an arrow pattern via a region near the edge of the light emitting window 102 provided in the housing 101. On the other hand, the second lighting device 200 is provided for the purpose of illuminating a wide area in front of the lighting device unit 100. The second lighting device 200 illuminates the fan-shaped second illuminated area Z2 on the installation surface S via the central area of the light emitting window 102.

  In the illustrated example, the lighting device unit 100 further outputs the light L1 emitted from the light source 20 of the first lighting device 10 in accordance with the radiant flux of the light L2 emitted from the light source 220 of the second lighting device 200. It has a controller 250 for adjusting the radiant flux. The control device 250 controls the first illuminance of the light L1 emitted from the light source 20 of the first illumination device 10 to be smaller than the radiance of the light L2 emitted from the light source 220 of the second illumination device 200. The radiance of light emitted from the light source 20 of the illumination device 10 is adjusted. The control device 250 adjusts the radiance of the light L2 emitted from the light source 220 of the second lighting device 200 according to the radiance of the light L1 emitted from the light source 20 of the first lighting device 10. It may be. In this case, the control device 250 sets the radiance of the light L1 emitted from the light source 20 of the first lighting device 10 to be smaller than the radiance of the light L2 emitted from the light source 220 of the second lighting device 200. The radiance of the light L2 emitted from the light source 220 of the second lighting device 200 is adjusted. Of course, without controlling either the radiance of the light L2 emitted from the light source 220 of the second lighting device 200 or the radiance of the light L1 emitted from the light source 20 of the first lighting device 10, the light source 220 When the radiance of the light emitted from the light source 20 is smaller than the radiance of the light emitted from the illumination device unit 100, the lighting device unit 100 may not include the control device 250 as described above. In the illustrated example, the control device 250 is also stored in the housing 101 together with the first lighting device 10 and the second lighting device 200.

  When observing the light emitting window 102 of the lighting device unit 100 as described above, as shown in FIG. 7, light L1 from the first lighting device 10 is formed in a region near the edge of the light emitting window 102. A linear pattern is observed. Further, a pattern formed by the light L2 from the second lighting device 200 is observed in a central region of the light projecting window 102 which is on one side of the linear pattern formed by the light L1. Here, in the illustrated example, the pattern formed by the light L2 is a circular pattern. The brightness of the linear pattern formed by the light L1 from the first lighting device 10 is equal to the pattern formed by the light L2 from the second lighting device 200 formed in the center of the light projecting window 102. Weaker than the brightness. For this reason, the brightness of one side (the central area side of the light emitting window 102) of the linear pattern formed by the light L1 from the first lighting device 10 and the brightness of the other side (the outside of the light emitting window 102). Can be reduced. As a result, of the contour of the pattern formed by the light L2 from the second lighting device 200, a portion adjacent to the linear pattern formed by the light L1 from the first lighting device 10 is made inconspicuous. be able to. Thereby, the appearance of the lighting device unit 100 can be improved.

  Note that the lighting device unit 100 may include a plurality of first lighting devices 10. For example, as shown in FIG. 8, the lighting device unit 100 includes a plurality of second lighting devices such that a linear pattern is formed over the entire circumference of the pattern formed by the light L2 from the second lighting device 200. One lighting device 10 may be included.

  In the second embodiment described above, the lighting device unit 100 includes the first lighting device 10 that is the lighting device 10 described in the first embodiment and the light source 220 that emits the light L2. And a second lighting device 200 having the same. In this case, the appearance of the lighting device unit 100 is improved by combining a linear pattern formed by the light L1 from the first lighting device 10 and a pattern formed by the light L2 from the second lighting device 200. Can be done.

  In the illustrated example, the illuminating device unit 100 includes a radiant flux of light L1 emitted from the light source 20 of the first lighting device 10 in accordance with a radiant flux of light L2 emitted from the light source 220 of the second lighting device 200. Is further provided with a control device 250 for adjusting. In this case, the brightness of the linear pattern formed by the light L1 from the first lighting device 10 can be adjusted according to the brightness of the pattern formed by the light L2 from the second lighting device 200. The appearance of the lighting device unit 100 can be further improved.

  Specifically, the control device 250 sets the radiance of the light L1 emitted from the light source 20 of the first lighting device 10 to be smaller than the radiance of the light L2 emitted from the light source 220 of the second lighting device 200. Thus, the radiance of the light L1 emitted from the light source 20 of the first lighting device 10 is adjusted. In this case, using the linear pattern formed by the light L1 from the first lighting device 10, the brightness of the pattern formed by the light L2 from the second lighting device 200 and the brightness of the outer peripheral portion thereof are improved. Can be reduced. Therefore, the contour of the pattern formed by the light L2 from the second lighting device 200 can be made inconspicuous, and the appearance of the lighting device unit 100 can be improved.

  Of course, the control device 250 adjusts the radiance of the light L2 emitted from the light source 220 of the second lighting device 200 according to the radiance of the light L1 emitted from the light source 20 of the first lighting device 10. It may be. In this case, the brightness of the pattern formed by the light L2 from the second lighting device 200 can be adjusted according to the brightness of the pattern formed by the light L1 from the first lighting device 10. The appearance of the device unit 100 can be further improved.

  For example, the control device 250 sets the radiance of the light L1 emitted from the light source 20 of the first lighting device 10 to be smaller than the radiance of the light L2 emitted from the light source 220 of the second lighting device 200. If the radiance of the light L2 emitted from the light source 220 of the second lighting device 200 is adjusted, the linear pattern formed by the light L1 from the first lighting device 10 may be used. The difference between the brightness of the pattern formed by the light L2 from the second illumination device 200 and the brightness of the outer periphery thereof can be reduced. Then, the contour of the pattern formed by the light L2 from the second lighting device 200 is made inconspicuous, and the appearance of the lighting device unit 100 can be improved.

  Note that the light source 220 of the second lighting device 200 may emit laser light. In addition, the light source 220 of the second lighting device 200 may include at least one of a halogen lamp, an LED, an HID lamp, a xenon lamp, a sodium lamp, a metal halide lamp, and a mercury lamp.

  The lighting device unit 100 further includes a housing 1 that houses the first lighting device 10 and the second lighting device 200. In this case, installation of the lighting device unit 100 including the first lighting device 10 and the second lighting device 200 is easy. In the illustrated example, the lighting device unit 100 includes a control device 250, and the housing 1 houses the first lighting device 10, the second lighting device 200, and the control device 250. Therefore, it is easy to install the lighting device unit 100 including the first lighting device 10, the second lighting device 200, and the control device 250. As described in the first embodiment, if the first lighting device 10 is configured to have a small size, the size of the housing 1 may be limited for some reason. Also, it is possible to store the first lighting device 10 and the second lighting device 200 or the first lighting device 10 and the second lighting device 200 and the control device 250 in one housing 1. it can.

  In the above, one embodiment and its modification have been described. However, it is needless to say that a plurality of configurations described as different modifications can be appropriately combined.

REFERENCE SIGNS LIST 1 housing 2 light emitting window 10 lighting device 20 light source 30 collimating lens 40 diffractive optical element 41 incident area 100 lighting device unit 101 housing 102 light emitting window 200 second lighting device 220 light source 250 of second lighting device Control device L Light L2 Light Lx Optical axis Z Illuminated area

Claims (16)

A plurality of light sources each emitting light,
A diffractive optical element that diffracts light emitted from the plurality of light sources and directs the light toward the illuminated area,
Each incident area of the light emitted from each light source on the diffractive optical element has a length in a first direction larger than a length in a second direction crossing the first direction,
The lighting device, wherein the plurality of light sources are arranged along the first direction. The diffractive optical element has an incident surface on which the light is incident,
The lighting device according to claim 1, wherein a length of the incident surface in the first direction is larger than a length of the incident surface in the second direction.   The lighting device according to claim 1, wherein the light source is a semiconductor laser, a solid-state laser, or an SHG laser.   The lighting device according to claim 1, wherein a diffusion angle of the light emitted by the light source in the first direction is larger than a diffusion angle in the second direction.   The illumination according to any one of claims 1 to 4, further comprising a collimator lens between each light source along the optical path of the light and the diffractive optical element, the collimator lens bringing the light emitted from the light source closer to a parallel light flux. apparatus.   The lighting device according to claim 5, wherein the light from the light source is directly incident on the collimating lens. A plurality of light sources each emitting light,
A diffractive optical element that diffracts light emitted from the plurality of light sources and directs the light toward the illuminated area,
Each of the plurality of incident regions on the diffractive optical element of the light emitted from the plurality of light sources is elongated,
The plurality of light sources are arranged on a straight line or a curve,
The lighting device, wherein a longitudinal direction of each incident region is along a direction in which the straight line or the curved line extends in a light source corresponding to the incident region. A first lighting device, which is the lighting device according to any one of claims 1 to 7,
A second lighting device having a light source for emitting light;   The control device according to claim 8, further comprising a control device that adjusts a radiance of light emitted from the light source of the first lighting device according to a radiance of light emitted from the light source of the second lighting device. Lighting unit.   The control device is configured to control the first lighting device so that the radiance of light emitted from the light source of the first lighting device is smaller than the radiance of light emitted from the light source of the second lighting device. The lighting device unit according to claim 9, wherein a radiance of light emitted from the light source is adjusted.   9. The control device according to claim 8, further comprising a control device for adjusting a radiance of light emitted from the light source of the second lighting device according to a radiance of light emitted from the light source of the first lighting device. Lighting unit.   The control device is configured to control the second lighting device so that the radiance of light emitted from the light source of the first lighting device is smaller than the radiance of light emitted from the light source of the second lighting device. The lighting device unit according to claim 11, wherein the radiance of light emitted from the light source is adjusted.   The lighting device unit according to any one of claims 8 to 12, wherein the light source of the second lighting device emits a laser beam.   The lighting device according to any one of claims 8 to 12, wherein the light source of the second lighting device includes at least one of a halogen lamp, an LED, an HID lamp, a xenon lamp, a sodium lamp, a metal halide lamp, and a mercury lamp. unit.   The lighting device unit according to any one of claims 8 to 14, further comprising a housing for housing the first lighting device and the second lighting device.   The lighting device unit according to any one of claims 9 to 12, further comprising a housing that houses the first lighting device, the second lighting device, and the control device.

Images