JP2018181618A - Lighting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an illuminating device capable of illuminating an illuminated area with a desired illumination pattern and a desired color without restrictions. An illuminating device 10 includes a light source 15 that emits coherent light L1, a phosphor 20 that is incident with coherent light L1 emitted from the light source 15, and a light source 15 and a phosphor 20 along an optical path of the coherent light L1. The diffractive optical element 40 located between the two, the condensing lens 50 located between the diffractive optical element 40 and the phosphor 20 along the optical path of the coherent light L1, and the wavelength conversion light L2 emitted from the phosphor 20. An imaging optical system 30 provided on an optical path is provided. [Selection diagram] Fig. 1

Description

  Embodiments of the present disclosure relate to a lighting device.

  For example, as disclosed in Patent Document 1, an illumination apparatus including a laser light source and a hologram element is known. In the illumination device disclosed in Patent Document 1, the road surface can be illuminated with a desired illumination pattern by the hologram element diffracting the light from the light source.

JP, 2015-132707, A

  By the way, as one of the needs for a recent lighting device, there is a case where a region to be illuminated is illuminated with a desired illumination pattern and a desired color. In general, it is possible to illuminate the area to be illuminated with a desired color by using three types of laser light sources that emit light of the three primary colors of light, red (R), green (G) and blue (B). It is believed that. However, in actuality, the color that can illuminate the illuminated area is limited due to the difference in the output of these laser light sources.

  The embodiment of the present disclosure is made in consideration of the above points, and aims to provide an illumination device capable of illuminating a region to be illuminated with a desired illumination pattern and a desired color without limitation.

A lighting device according to an embodiment of the present disclosure is
A light source for emitting coherent light;
A phosphor on which coherent light emitted from the light source is incident;
A diffractive optical element located between the light source and the phosphor along the optical path of the coherent light;
A condenser lens positioned between the diffractive optical element and the phosphor along the optical path of the coherent light;
And an imaging optical system provided on the optical path of the wavelength conversion light emitted from the phosphor.

  In addition, the illumination device according to an embodiment of the present disclosure may further include a mask positioned between the phosphor along the optical path of the wavelength conversion light and the imaging optical system.

  In this case, the mask may be changeable in pattern.

  Further, in the illumination device according to one embodiment of the present disclosure, the diffractive optical element may include a plurality of element diffractive optical elements having different diffraction characteristics.

  In addition, the illumination apparatus according to an embodiment of the present disclosure may further include a variable mask that changes an incident area of the coherent light on the diffractive optical element.

  In addition, the illumination device according to an embodiment of the present disclosure may further include a scanning unit that changes an optical path of the coherent light to change an incident position on the diffractive optical element.

  According to the present disclosure, the illuminated area can be illuminated with a desired illumination pattern and a desired color.

FIG. 1 is a view for explaining an embodiment according to the present disclosure, and is a schematic view showing a lighting device. FIG. 2 is a view for explaining another embodiment according to the present disclosure, and is a schematic view showing a lighting device. FIG. 3 is a plan view showing the diffractive optical element shown in FIG. FIG. 4A is a diagram showing a desired illumination pattern of the region to be illuminated, and is a diagram showing an illumination pattern when laser light is diffracted by the first element diffractive optical element and the third element diffractive optical element. FIG. 4B is a diagram showing a desired illumination pattern of the region to be illuminated, and is a diagram showing an illumination pattern when laser light is diffracted by the second element diffractive optical element and the third element diffractive optical element. FIG. 5 is a view for explaining a modified example of the illumination device shown in FIG. 2, which shows the incident position of the laser light on the diffractive optical element when the optical path of the laser light is changed by the scanning means. Diagram showing change. FIG. 6 is a view for explaining another modification of the illumination device shown in FIG. 2 and is a diffractive optical element of laser light in the case where the optical path of the laser light is changed by moving the laser light emitting unit. The figure which shows the change of the incident position above.

  Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the drawings attached to the present specification, for the sake of easy illustration and understanding, the scale, the dimensional ratio in the vertical and horizontal directions, etc. are appropriately changed from those of the actual one and exaggerated.

  In addition, as used herein, the terms such as “parallel”, “orthogonal”, “identical”, values of length and angle, etc., which specify the shape and geometric conditions and their degree, etc. It shall be interpreted including the range which can expect the same function without being restricted by the meaning.

First Embodiment
First, the first embodiment will be described with reference to FIG.

  FIG. 1: is a schematic diagram which shows an example of the illuminating device 10 which concerns on 1st Embodiment. The illumination device 10 is a device that illuminates the illumination area Z with a desired illumination pattern and a desired color. In the illustrated example, the illuminated area Z has a linear illumination pattern, but is not limited thereto. The illumination area Z may be illuminated with an arbitrary illumination pattern, for example, an illumination pattern having a shape of a figure or a character. Such lighting devices can be used in various fields, for example as lighting devices for moving bodies such as cars and ships. When applied to a mobile object, the ground, floor, water surface, wall surface, and the like can be illuminated with an illumination pattern indicating information such as the traveling direction of the mobile object, and the information can be displayed around. In the example shown in FIG. 1, the lighting device 10 is applied to a motor vehicle to illuminate the ground or floor with a desired lighting pattern and a desired color.

  As shown in FIG. 1, in the first embodiment, the illumination device 10 has a light source 15 for emitting the coherent light L1, and a coherent light L1 emitted from the light source 15 to be incident, and has a wavelength different from that of the coherent light L1. It has the fluorescent substance 20 which inject | emits the light (wavelength conversion light) L2, and the imaging optical system 30 which images the wavelength conversion light L2 inject | emitted from the fluorescent substance 20. FIG. The illumination device 10 further includes a diffractive optical element 40 that diffracts the coherent light L1 from the light source 15 between the light source 15 and the fluorescent body 20 along the optical path of the coherent light L1 from the light source 15, and a diffractive optical element 40. And a condenser lens 50 for condensing the coherent light L1 diffracted by the The illumination device 10 further includes a mask 60 between the fluorescent body 20 along the optical path of the wavelength conversion light L2 from the fluorescent body 20 and the imaging optical system 30.

  The coherent light L1 emitted from the light source 15 is excellent in straightness, and is suitable as light for irradiating the phosphor 20 with high accuracy. In the following description, laser light is used as a preferred example of coherent light. In the example shown in FIG. 1, although the laser light source 15 has a single laser light emission part, it is not restricted to this. The laser light source 15 may include a plurality of laser emission units. When the laser light source 15 includes a plurality of laser emitting units, it is possible to provide the phosphor 20 with sufficient light energy.

  Next, the diffractive optical element 40 will be described. The diffractive optical element 40 is an element that exerts a diffractive action on the laser light L1 emitted from the laser light source 15. The diffractive optical element 40 is disposed between the laser light source 15 and the fluorescent body 20 along the optical path of the laser light L1, more specifically, between the laser light source 15 and the condenser lens 50. The diffractive optical element 40 diffracts the laser light L 1 from the laser light source 15 and directs it to the condensing lens 50.

  In the illustrated example, the illumination device 10 has a single diffractive optical element 40, but is not limited thereto. The illumination device 10 may have a plurality of diffractive optical elements. In particular, when the illumination device 10 has a plurality of laser emission units, the diffractive optical element may be provided corresponding to each of the plurality of laser emission units.

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

  Here, in the example shown in FIG. 1, the diffractive optical element 40 illuminates the phosphor 20 with the illumination pattern corresponding to the desired illumination pattern of the illuminated area Z, with the laser light L1 diffracted by the diffractive optical element 40 Thus, the traveling direction of the laser beam L1 diffused by the diffractive optical element 40 is controlled. When the fluorescent body 20 is illuminated with the illumination pattern corresponding to the desired illumination pattern of the illumination area Z, the pattern of the wavelength conversion light L2 emitted by the fluorescent body 20 also becomes a pattern corresponding to the desired illumination pattern, It is possible to illuminate the area Z with the desired illumination pattern. By controlling the traveling direction of the laser beam L1 by the diffractive optical element 40 as described above, the laser beam L1 from the laser light source 15 can be efficiently used.

  The diffractive optical element 40 can be produced, for example, using 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 the reference light and the object light which are coherent light having mutual interference, the interference fringes due to the interference of these lights become the hologram photosensitive material The diffractive optical element 40 is manufactured. As the reference light, laser light which is coherent light is used. As the object light, for example, scattered light from an isotropic scattering plate which can be obtained inexpensively is used.

  By irradiating a laser beam toward the diffractive optical element 40 so that the optical path of the reference beam used when producing the diffractive optical element 40 is reversed, the object light used when producing the diffractive optical element 40 At the arrangement position of the original scattering plate, a reproduced image of the scattering plate is generated. If the scattering plate which is the source of the object light used when producing the diffractive optical element 40 performs uniform surface scattering, the reproduced image of the scattering plate obtained by the diffractive optical element 40 also has uniform surface illumination It becomes.

  Further, instead of forming a complex interference fringe pattern formed in the diffractive optical element 40 using real object light and reference light, the wavelength and incident direction of the planned reproduction illumination light, and the reproduction should be reproduced. It is possible to design using a computer based on the shape, position, etc. of the image. The diffractive optical element 40 thus obtained is also called a computer generated hologram (CGH).

  Also, Fourier transform holograms may be formed by computer synthesis in which the diffusion angle characteristics at each point on the diffractive optical element 40 are the same.

  As a specific form of the diffractive optical element 40, a volume type hologram recording medium using a photopolymer may be used, or a volume type hologram recording medium of a type recording using a photosensitive medium containing a silver salt material may be used. It may be a relief type (emboss type) hologram recording medium. The diffractive optical element 40 may be transmissive or reflective.

  Next, the condenser lens 50 will be described. The condensing lens 50 is disposed between the diffractive optical element 40 and the phosphor 20 along the optical path of the laser beam L1. The condensing lens 50 condenses the laser light L1 that is diffracted and diffused by the diffractive optical element 40, and reduces the area of the fluorescent member 20 on which the laser light L1 is irradiated. Thereby, the energy density of the laser beam L1 which irradiates the fluorescent substance 20 can be raised.

  Next, the phosphor 20 will be described. The phosphor 20 is disposed at or near a position where the area irradiated by the laser beam L1 collected by the collecting lens 50 is minimum. The phosphor 20 is excited when the laser light L1 is irradiated, and emits the wavelength conversion light L2 in a wavelength range different from that of the laser light L1 incident on the phosphor 20. For example, when laser light in the blue wavelength range is incident, the phosphor 20 emits wavelength converted light in the yellow wavelength range. In the illumination device 10, since the illumination area Z is illuminated by the wavelength conversion light emitted from the fluorescent body 20, the illumination area Z can be illuminated with a desired color by appropriately selecting the fluorescent body 20. The pattern of the wavelength conversion light L2 emitted from the phosphor 20 is substantially the same as the pattern of the laser light L1 irradiated to the phosphor 20.

  Here, in the example illustrated in FIG. 1, the wavelength conversion light L2 emitted from the phosphor 20 is directly irradiated to the illumination region Z as described later. That is, in the example shown in FIG. 1, the color (for example, yellow or white) of the wavelength conversion light L2 emitted from the phosphor 20 is the color of the light finally emitted from the lighting device 10. However, for example, a filter for transmitting light of a specific wavelength band is provided on the downstream side of the fluorescent body 20, and the wavelength-converted light L2 emitted from the fluorescent body 20 is incident on the filter. Can change the color of the light emitted.

  The imaging optical system 30 is provided on the optical path of the wavelength conversion light L2 emitted from the phosphor 20. The imaging optical system 30 focuses the wavelength converted light L2 on the ground or floor. Thereby, the illumination area Z is illuminated with a color according to the illumination pattern corresponding to the pattern of the wavelength conversion light L2 and the wavelength range of the wavelength conversion light L2.

  By the way, as described above, the pattern of the wavelength conversion light L2 emitted from the phosphor 20 substantially matches the pattern of the laser light L1 irradiated to the phosphor 20. However, due to diffusion or the like of the light propagated inside the phosphor 20, the pattern of the wavelength conversion light L2 emitted from the phosphor 20 may be blurred compared to the pattern of the laser light L1. When such wavelength-converted light L2 is imaged by the imaging optical system 30, the illuminated area Z is illuminated with a blurred and unclear illumination pattern of the outline. Therefore, in the present embodiment, the mask 60 is disposed between the fluorescent body 20 and the imaging optical system 30 along the optical path of the wavelength conversion light L2. The mask 60 is a plate-like member that transmits the wavelength conversion light L2 with a desired transmission pattern, that is, a transmission pattern according to the desired illumination pattern of the illuminated area Z, but is not limited thereto. For example, the mask 60 may be a variable mask that can make the pattern to be shaped variable. A spatial light modulator can be used as such a variable mask. For the spatial modulator, a transmissive liquid crystal display device, a reflective liquid crystal display device, a digital micro mirror device (DMD) or the like may be used. That is, the mask 60 may be a device that transmits the wavelength conversion light L2 in a desired transmission pattern, or may be a device that reflects the wavelength conversion light L2 in a desired reflection pattern. In addition, the mask 60 may absorb the unnecessary wavelength conversion light L2 or may direct the unnecessary wavelength conversion light L2 to other than the imaging optical system 30.

  When the phosphor 20 is sufficiently thin and diffusion of light propagating inside the phosphor 20 is small, for example, when the pattern of the wavelength-converted light L2 emitted by the phosphor 20 is sufficiently sharp, the illumination device 10 May not have the mask 60.

  Next, the operation of the lighting device 10 configured as described above will be described.

  The laser beam L1 emitted from the laser light source 15 first enters the diffractive optical element 40. The diffractive optical element 40 records interference fringes corresponding to the central wavelength of the laser beam L1 emitted from the laser light source 15, and can diffract the laser beam L1 incident from a certain direction with high efficiency in a desired direction. it can. In the illustrated example, the diffractive optical element 40 diffracts the laser light L1 with a pattern corresponding to a desired illumination pattern of the illumination area Z, and diffuses the diffracted light L1 toward the condensing lens 50.

  The laser beam L1 incident on the condensing lens 50 is condensed toward the focal point of the condensing lens 50 while maintaining the pattern, and illuminates the phosphor 20.

  The phosphor 20 is excited by the laser beam L1 and emits wavelength conversion light L2 in a desired wavelength range different from the laser beam L1. The pattern of the wavelength conversion light L2 emitted from the phosphor 20 is substantially the same as the pattern of the laser light L1 incident on the phosphor 20, and is a pattern corresponding to the desired illumination pattern of the illuminated area Z. The wavelength conversion light L2 is incident on the mask 60. The wavelength-converted light L 2 transmitted through the mask 60 in a transmission pattern corresponding to the desired illumination pattern of the illuminated area Z is incident on the imaging optical system 30. The wavelength conversion light L2 incident on the imaging optical system 30 is imaged to illuminate the illumination area Z with a desired illumination pattern and a desired color.

  In addition, although the case where the fluorescent substance 20 was illuminated with the illumination pattern corresponding to the desired illumination pattern of the to-be-illuminated area | region Z by laser beam L1 was demonstrated, it is not restricted to this. Specifically, the phosphor 20 may be illuminated by the laser beam L1 with an illumination pattern different from the desired illumination pattern of the illuminated area Z. In this case, although the pattern of the wavelength conversion light L2 emitted by the phosphor 20 is substantially the same as the different pattern, the pattern of the wavelength conversion light L2 is transmitted to the desired illumination of the illumination region Z by transmitting the mask 60. It can be made a pattern corresponding to a pattern. Also in this case, it is possible to illuminate the illuminated area Z with a desired illumination pattern and a desired color while efficiently using the laser light L1 from the laser light source 15.

  Further, as described above, the mask 60 may be capable of changing the pattern of the wavelength-converted light L2 emitted from the phosphor 20, and as a result, the illumination pattern of the illuminated area Z.

  Moreover, the illuminating device 10 may illuminate the to-be-illuminated area | region Z with another laser light source. In this case, the to-be-illuminated area Z may be illuminated with a desired color by superposing the wavelength conversion light L2 emitted by the phosphor 20 of the lighting device 10 with the laser light from another laser light source.

  According to the embodiment of the present disclosure as described above, the lighting apparatus 10 includes the light source 15 for emitting the coherent light L1, the phosphor 20 for the coherent light L1 emitted from the light source 15 to be incident, and the light path of the coherent light L1. A diffractive optical element 40 positioned between the light source 15 and the phosphor 20, a condenser lens 50 positioned between the diffractive optical element 40 and the phosphor 20 along the optical path of the coherent light L1, and the phosphor And an imaging optical system 30 provided on the optical path of the wavelength conversion light L2 emitted from the light source 20.

  In the illumination device 10 as described above, the wavelength conversion light L2 emitted from the phosphor 20 is allowed to enter the illumination area Z, whereby the illumination area Z can be illuminated with a desired color. Further, the coherent light L1 emitted from the light source 15 is diffracted by the diffractive optical element 40 and incident on the fluorescent body 20, whereby the coherent light L1 from the light source 15 can be efficiently used. Furthermore, when the coherent light L1 is diffracted by the diffractive optical element 40 in a pattern corresponding to the desired illumination pattern of the illumination region Z and is incident on the phosphor 20, the pattern of the wavelength converted light L2 emitted from the phosphor 20 is also The pattern corresponds to the desired illumination pattern, the coherent light L1 can be used more efficiently, and the illumination area Z can be illuminated with the desired illumination pattern.

  For example, the illumination device 10 may further include a mask 60 positioned between the fluorescent body 20 along the light path of the wavelength conversion light L2 and the imaging optical system 30. In this case, regardless of the pattern of the wavelength conversion light L2 emitted from the phosphor 20, the pattern of the wavelength conversion light L2 incident on the imaging optical system 30 is made a pattern corresponding to the desired illumination pattern of the illumination area Z be able to.

Second Embodiment
Next, a second embodiment will be described with reference to FIGS. 2 to 4B. In the second embodiment, in comparison with the illumination device of the first embodiment, the laser light source has a plurality of laser emission units, and the diffractive optical element includes a plurality of element diffractive optical elements. , The illumination device includes a variable mask for changing the incident region of laser light on the diffractive optical element, and the mask disposed between the phosphor and the imaging optical system is capable of changing the transmission pattern. There are some differences. However, the other configuration is substantially the same as that of the first embodiment. In the following description and the drawings used in the following description, parts that can be configured similarly to the above-described first embodiment are the same as the reference numerals used for the corresponding parts in the above-described first embodiment. The code is used and the redundant description is omitted.

  FIG. 2 is a view corresponding to FIG. 1 and is a schematic view showing an example of the illumination device 110 according to the second embodiment. As shown in FIG. 2, the laser light source 115 has a first laser light emitting unit 115 a that emits a laser beam L 1 a and a second laser light emitting unit 115 b that emits a laser beam L 1 b. Further, as shown in FIG. 3, the diffractive optical element 140 has first to third element diffractive optical elements 140a, 140b, and 140c. The first to third element diffractive optical elements 140a, 140b, and 140c are disposed to divide one optical element into two. As shown in FIG. 2, the first and second element diffractive optical elements 140 a and 140 b are disposed between the first laser light emitting unit 115 a and the condenser lens 50 along the optical path of the laser light L 1 a. The third element diffractive optical element 140 c is disposed between the second laser emission unit 115 b and the condenser lens 50 along the optical path of the laser beam L 1 b. The plurality of element diffractive optical elements 140a, 140b, and 140c need not be in contact with each other, and may be separated from each other.

  The first to third element diffractive optical elements 140a, 140b, and 140c have different diffraction characteristics. In the example shown in FIG. 2, in the first and second element diffractive optical elements 140a and 140b, the patterns of the laser light L1a diffracted by the first and second element diffractive optical elements 140a and 140b are respectively shown in FIG. The laser beam L1a is diffracted so as to have a pattern corresponding to the desired illumination pattern of the element illumination areas Za and Zb shown in FIG. 4B. The third element diffractive optical element 140c has a pattern in which the pattern of the laser beam L1b diffracted by the third element diffractive optical element 140c corresponds to the desired illumination pattern of the element illumination area Zc shown in FIGS. 4A and 4B. The laser beam L1b is diffracted so that

  A variable mask 70 is disposed between the first laser emitting unit 115a and the first and second element diffractive optical elements 140a and 140b along the optical path of the laser beam L1a. The variable mask 70 changes the incident region of the laser beam L1a on the diffractive optical element 140 between the first element diffractive optical element 140a and the second element diffractive optical element 140b. Specifically, the variable mask 70 is an optical path between the first laser emitting portion 115a of the laser beam L1a and the first element diffractive optical element 140a, or a first laser emitting portion 115a of the laser beam L1a and a second element By selectively blocking the optical path to the diffractive optical element 140 b, the incident region of the laser beam L 1 a on the diffractive optical element 140 is changed. As such a variable mask 70, for example, a spatial light modulator can be used, and as the spatial light modulator, a transmissive liquid crystal display device, a reflective liquid crystal display device, a digital micro mirror device (DMD), etc. are exemplified. Ru.

  The fluorescent substance 20 is excited when the laser beams L1a and L1b are incident, and emits wavelength-converted light L2a and L2b.

  A mask 160 disposed between the phosphor 20 along the optical path of the wavelength conversion lights L2a and L2b and the imaging optical system 30 transmits the wavelength conversion lights L2a and L2b in a desired transmission pattern. The mask 160 can change its transmission pattern, and changes the transmission pattern as the variable mask 70 operates. Specifically, when the variable mask 70 causes the laser light L1a to be incident on the first element diffractive optical element 140a, the mask 160 has a wavelength conversion light L2a with a transmission pattern corresponding to the desired illumination pattern Z1 shown in FIG. 4A. , L2b. When the variable mask 70 causes the laser light L1a to be incident on the second element diffractive optical element 140b, the mask 160 transmits the wavelength converted light L2a and L2b in a transmission pattern corresponding to the desired illumination pattern Z2 shown in FIG. 4B. Permeate. As the mask 160, for example, a spatial light modulator can be used, and as the spatial light modulator, a transmissive liquid crystal display device, a reflective liquid crystal display device, a digital micro mirror device (DMD), etc. are exemplified. .

  Next, the operation of the lighting device 110 configured as described above will be described.

  The laser beam L 1 b emitted from the second laser emission unit 115 b of the laser light source 15 is incident on the third element diffractive optical element 140 c of the diffractive optical element 40. The third element diffractive optical element 140 c diffracts the laser light L 1 b in a pattern corresponding to the element illumination area Zc shown in FIGS. 4A and 4B, and diffuses the diffracted light L 1 b toward the condensing lens 50. On the other hand, the laser beam L1a emitted from the first laser emission unit 115a of the laser light source 15 first enters the variable mask 70. The variable mask 70 changes the incident area of the laser beam L1a on the diffractive optical element 140. The laser beam L1a transmitted through the variable mask 70 is incident on one of the first element diffractive optical element 140a and the second element diffractive optical element 140b of the diffractive optical element 40. The first and second element diffractive optical elements 140a and 140b respectively diffract the laser light L1a in a pattern corresponding to the element illumination areas Za and Zb shown in FIGS. 4A and 4B, and collect the diffracted light L1a as a condensing lens Spread towards 50.

  The laser beams L1a and L1b incident on the condensing lens 50 are condensed toward the focal point of the condensing lens 50 and enter the fluorescent body 20 while maintaining the pattern. At this time, the laser beams L1a and L1b diffracted by the first and third element diffractive optical elements 140a and 140c illuminate the phosphor 20 with the illumination pattern corresponding to the illumination area Z1 shown in FIG. 4A. The laser beams L1a and L1b diffracted by the second and third element diffractive optical elements 140b and 140c illuminate the phosphor 20 with the illumination pattern corresponding to the illumination area Z2 shown in FIG. 4B.

  The phosphor 20 is excited by the laser beams L1a and L1b, and emits wavelength-converted light L2a and L2b in a wavelength range different from that of the laser beams L1a and L1b. The patterns of the wavelength conversion lights L2a and L2b emitted from the phosphor 20 are substantially the same as the patterns of the laser lights L1a and L1b incident on the phosphor 20. The wavelength-converted light L2a and L2b are incident on the mask 160, and transmit the mask 160 in a desired transmission pattern. Specifically, when the variable mask 70 causes the laser light L1a to be incident on the first element diffractive optical element 140a, the wavelength converted lights L2a and L2b are used to illuminate the mask 160 as desired illumination of the illumination region Z1 shown in FIG. 4A. It transmits in the transmission pattern corresponding to the pattern. When the variable mask 70 causes the laser light L1a to be incident on the second element diffractive optical element 140b, the wavelength converted light L2a and L2b correspond to the desired illumination pattern of the illumination area Z2 shown in FIG. 4B for the mask 160. The light is transmitted in a transparent pattern. The wavelength converted lights L2a and L2b transmitted through the mask 160 are incident on the imaging optical system 30 to form an image, and illuminate the illumination area Z1 or the illumination area Z2 with a desired illumination pattern and color.

  Although the case where the variable mask 70 changes the incident region of the laser beam L1a on the diffractive optical element 140 has been described, the present invention is not limited thereto. Specifically, as shown in FIG. 5, the illumination device 110 is a laser between the first laser light emitting unit 115a and the first and second element diffractive optical elements 140a and 140b along the optical path of the laser light L1a. The scanning unit 80 may be provided to change the light path of the light L1a to change the incident position of the laser light L1a on the diffractive optical element 140. In this case, the laser beam L1a from the first laser emission unit 115a scans the incident surface of the first and second element diffractive optical elements 140a and 140b.

  The scanning means 80 includes, for example, reflecting mirrors rotatable about two rotational axes respectively parallel to the directions intersecting with each other. By rotating the reflecting mirror around two rotation axes, the laser beam L1a from the first laser emission unit 115a scans two-dimensionally on the incident surface of the first and second element diffractive optical elements 140a and 140b. Is possible.

  Alternatively, as shown in FIG. 6, the incident region of the laser beam L1a on the diffractive optical element 140 may be changed by moving the first laser emission unit 115a.

  In the example shown in FIG. 2, the first laser light emitting unit 115 a and the second laser light emitting unit 115 b are provided. However, the present invention is not limited to this example, and a single laser light source is used. The laser light emitted from a single laser light source may be made incident on the first element diffractive optical element 140a, the second element diffractive optical element 140b, and the third element diffractive optical element 140c.

  Furthermore, the illumination device 110 may illuminate the illuminated area Z together with other laser light sources. In this case, the to-be-illuminated area Z may be illuminated with a desired color by superposing the wavelength-converted light emitted by the phosphor 20 of the lighting device 110 with the laser light from another laser light source.

  According to the embodiments of the present disclosure as described above, the diffractive optical element 140 includes a plurality of element diffractive optical elements 140a, 140b, and 140c having different diffraction characteristics. In this case, the illumination device 110 can illuminate the illumination regions Z1 and Z2 more accurately.

  The illumination device 110 further includes a variable mask 70 that changes the incident area of the coherent light L1a on the diffractive optical element 140. In this case, the illumination device 110 can illuminate the illuminated regions Z1 and Z2 with a plurality of desired illumination patterns by changing the element diffractive optical elements 140a and 140b on which the coherent light L1a is incident.

  Alternatively, the illumination device 110 may further include a scanning unit 80 that changes the optical path of the coherent light L1a to change the incident position on the diffractive optical element 140. Also in this case, the illumination device 110 can illuminate the illumination regions Z1 and Z2 with a plurality of desired illumination patterns by changing the element diffractive optical elements 140a and 140b on which the coherent light L1a is incident.

  In the above, although several embodiment and its modification were demonstrated, it is also possible to combine suitably the several structure demonstrated as a different embodiment and a different modification, of course.

DESCRIPTION OF SYMBOLS 10 illumination apparatus 15 light source 20 fluorescent substance 30 imaging optical system 40 diffractive optical element 50 condensing lens 60 mask 80 scanning means

Claims (6)

A light source for emitting coherent light;
A phosphor on which coherent light emitted from the light source is incident;
A diffractive optical element located between the light source and the phosphor along the optical path of the coherent light;
A condenser lens positioned between the diffractive optical element and the phosphor along the optical path of the coherent light;
An imaging optical system provided on an optical path of wavelength conversion light emitted from the phosphor.   The lighting device according to claim 1, further comprising a mask positioned between the phosphor along the light path of the wavelength conversion light and the imaging optical system.   The lighting device according to claim 2, wherein the mask is capable of changing a pattern.   The illumination device according to any one of claims 1 to 3, wherein the diffractive optical element includes a plurality of element diffractive optical elements having different diffraction characteristics.   The illumination device according to claim 4, further comprising a variable mask that changes an incident area of the coherent light on the diffractive optical element.   5. The illumination apparatus according to claim 4, further comprising scanning means for changing an optical path of the coherent light to change an incident position on the diffractive optical element.

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