JP2019133950A - Lighting device for movable body and movable body - Google Patents

Abstract

To provide a lighting device that can project light in a plurality of directions.SOLUTION: A lighting device 10 includes: a light source 15 for emitting light; a diffractive optical element 40 for diffracting light emitted from the light source 15; a projection optical system 50 for reflecting or refracting light diffracted by the diffractive optical element 40 to orient light toward a projection surface S. The projection optical system 50 orients part of primary diffraction light diffracted by the diffractive optical element 40 and part of the other in different directions.SELECTED DRAWING: Figure 2

Description

  The present disclosure relates to a lighting device.

  For example, as disclosed in Patent Document 1, an illumination device including a light source and a hologram element is known. The vehicular illumination device disclosed in Patent Document 1 can illuminate a projection surface such as a road surface by projecting light in a specific direction by the hologram element diffracting light from a light source.

JP 2012-146621 A

  By the way, when illuminating using an illuminating device, there are cases where it is desired to project light in a plurality of directions and perform a plurality of illuminations simultaneously. If light can be projected in a plurality of directions, for example, the projection plane can be divided into a plurality of regions by illuminating the projection plane with a plurality of linear patterns extending in a plurality of directions.

  Embodiments of the present disclosure have been made in consideration of the above points, and an object thereof is to provide an illumination device that can project light in a plurality of directions.

A lighting device according to an embodiment of the present disclosure includes:
A light source that emits light;
A diffractive optical element that diffracts the light emitted from the light source;
A projection optical system that reflects or refracts the light diffracted by the diffractive optical element and directs it toward the projection surface, and
The projection optical system directs a part of the first-order diffracted light diffracted by the diffractive optical element and another part in different directions.

In a lighting device according to an embodiment of the present disclosure,
The diffractive optical element includes a first element diffractive optical element that diffracts part of the light emitted from the light source, a second element diffractive optical element that diffracts another part of the light emitted from the light source, and Have
The projection optical system includes first diffracted light that is first-order diffracted light diffracted by the first element diffractive optical element, second diffracted light that is first-order diffracted light diffracted by the second element diffractive optical element, and May be directed in different directions.

  In the illumination device according to the embodiment of the present disclosure, the projection optical system may be a reflective element or a prism.

  In the illumination device according to the embodiment of the present disclosure, the projection optical system includes a half mirror that reflects part of the first-order diffracted light diffracted by the diffractive optical element and transmits the other part, and the half mirror. A reflective element that reflects the other part of the transmitted first-order diffracted light.

  In the illumination device according to the embodiment of the present disclosure, the projection optical system may be a projection diffractive optical element that diffracts light diffracted by the diffractive optical element.

In the lighting device according to the embodiment of the present disclosure,
The diffractive optical element includes a first element diffractive optical element that diffracts part of the light emitted from the light source, a second element diffractive optical element that diffracts another part of the light emitted from the light source, and Have
The projection diffractive optical element includes a first projection element diffractive optical element that diffracts first diffracted light that is first-order diffracted light diffracted by the first element diffractive optical element and directs the first diffracted light in a first direction; A second projection element diffractive optical element that diffracts the second diffracted light that is diffracted by the two-element diffractive optical element and directs the second diffracted light in a second direction different from the first direction; Also good.

  The illumination device according to the embodiment of the present disclosure may further include a collimator lens disposed between the light source and the diffractive optical element along an optical path from the light source to the diffractive optical element.

  In the illumination device according to the embodiment of the present disclosure, the projection optical system changes a traveling direction of a part of the first-order diffracted light diffracted by the diffractive optical element at an angle exceeding 90 °, and the diffractive optical The traveling direction of the other part of the first-order diffracted light diffracted by the element may be changed at an angle exceeding 90 °.

  Moreover, the illuminating device by embodiment of this indication may be accommodated in the cylindrical housing | casing.

  In this case, the housing may be arranged to be rotatable.

  Moreover, the illuminating device by embodiment of this indication may be supported rotatably.

  In the illumination device according to the embodiment of the present disclosure, the projection optical system may be rotatably supported.

  In the illumination device according to the embodiment of the present disclosure, the diffractive optical element may be rotatably supported.

In addition, the lighting device according to the embodiment of the present disclosure includes:
A first lens disposed between the diffractive optical element and the projection optical system along an optical path from the diffractive optical element to the projection optical system, the focal length of the first lens from the diffractive optical element A first lens spaced apart by a distance,
A second lens disposed between the first lens and the projection optical system along an optical path from the first lens to the projection optical system, the focal length of the first lens from the first lens; And a second lens that is spaced apart by the sum of the focal length of the second lens,
A zero-order light mask disposed between the first lens and the second lens along an optical path from the first lens to the second lens, and blocking zero-order light in the diffractive optical element; Furthermore, you may provide.

In addition, the lighting device according to the embodiment of the present disclosure includes:
A first lens disposed between the diffractive optical element and the projection optical system along an optical path from the diffractive optical element to the projection optical system, the focal length of the first lens from the diffractive optical element A first lens spaced apart by a distance,
A second lens disposed between the first lens and the projection optical system along an optical path from the first lens to the projection optical system, the focal length of the first lens from the first lens; And a second lens that is spaced apart by the sum of the focal length of the second lens,
A high-order diffracted light mask disposed between the first lens and the second lens along an optical path from the first lens to the second lens, and blocking high-order diffracted light from the diffractive optical element; Furthermore, you may provide.

In the lighting device according to the embodiment of the present disclosure,
The projection optical system reflects or refracts a part of the first-order diffracted light diffracted by the diffractive optical element and the other part and directs the first and second illuminated areas on the projection surface, respectively. ,
The first illuminated area and the second illuminated area may extend along a straight line as a whole. Furthermore, in this case, the first illuminated area and the second illuminated area may extend in a straight line.

  According to this indication, an illuminating device which can project light in a plurality of directions can be provided.

FIG. 1 is a perspective view illustrating a lighting device for explaining a first embodiment according to the present disclosure. FIG. 2 is a schematic diagram illustrating an example of the configuration of the illumination device in FIG. 1. FIG. 3 is a diagram for explaining a modification of the illumination device shown in FIG. 2, in which the length of the region illuminated by the illumination device shown in FIG. 2 and the illumination device that projects light in a single direction. It is a figure which shows the length of the area | region illuminated. FIG. 4 is a diagram showing another modification of the illumination device shown in FIG. FIG. 5 is a diagram showing still another modification of the illumination device shown in FIG. FIG. 6 is a diagram showing still another modification of the illumination device shown in FIG. FIG. 7 is a diagram showing still another modification of the lighting device shown in FIG. FIG. 8 is a diagram corresponding to FIG. 2, and is a diagram showing still another modification of the illumination device shown in FIG. 2. FIG. 9 is a diagram showing a change in the illuminated area illuminated by the illumination device shown in FIG. 8, and is a view of the illumination device and the projection surface shown in FIG. 8 as viewed from above. FIG. 10 is a diagram corresponding to FIG. 2, and is a diagram showing still another modification of the illumination device shown in FIG. 2. FIG. 11 is a diagram corresponding to FIG. 2, and is a diagram showing still another modification of the illumination device shown in FIG. 2. FIG. 12 is a diagram corresponding to FIG. 2, and is a schematic diagram illustrating an example of the configuration of the illumination device according to the second embodiment of the present disclosure.

  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 illustration and ease of understanding, the scale, the vertical / horizontal dimension ratio, and the like are appropriately changed and exaggerated from those of the actual product.

  In addition, as used in this specification, the shape and geometric conditions and the degree thereof are specified. For example, terms such as “parallel”, “orthogonal”, “identical”, length and angle values, etc. are strictly Without being bound by any meaning, it should be interpreted including the extent to which similar functions can be expected.

<First Embodiment>
First, the first embodiment will be described with reference to FIGS. 1 and 2.

  FIG. 1 is a perspective view illustrating an example of a lighting device 10 according to the first embodiment. FIG. 2 is a schematic diagram illustrating an example of the configuration of the illumination device 10 illustrated in FIG. 1.

  As shown in FIG. 1, the illuminating device 10 is installed on the ground or floor surface, and illuminates two different illuminated areas Z1 and Z2 with the installation surface as the projection surface S. More specifically, the illumination device 10 projects light in two different directions to illuminate the first illuminated area Z1 and the second illuminated area Z2 with a linear pattern. Such an illuminating device 10 can be used when partitioning the projection surface S, for example. That is, the illuminating device 10 can show the boundary line of the divided area by the linear illuminated areas Z1 and Z2. In addition, the illuminating device 10 may illuminate the illuminated areas Z1 and Z2 with an arbitrary pattern other than a line shape, and may illuminate with, for example, a figure or a character pattern. Moreover, the illuminating device 10 may illuminate the illuminated areas Z1 and Z2 with different patterns.

  As shown in FIG. 2, in the first embodiment, the illumination device 10 is diffracted by the light source 15 that emits light, the diffractive optical element 40 that diffracts the light emitted from the light source 15, and the diffractive optical element 40. A projection optical system 50 that reflects or refracts light and directs the light toward the projection surface S. In the example shown in FIG. 2, the illumination device 10 further includes a shaping optical system 30 including a collimator lens 32 between the light source 15 and the diffractive optical element 40.

  As can be understood from FIGS. 1 and 2, the illumination device 10 is housed in a cylindrical housing 60 and can stand on the projection surface S. In the illustrated example, the light source 15, the diffractive optical element 40, and the projection optical system 50 are aligned in a substantially vertical direction with respect to the projection plane S in the housing 60. The housing 60 is provided with an opening 61 through which light reflected or refracted by the projection optical system 50 is transmitted. Hereafter, each component of the illuminating device 10 is demonstrated in order.

  As the light source 15, various types of light sources can be used. As an example, a light source that emits coherent light, such as a laser light source, can be used as the light source 15. The coherent light emitted from the light source 15 has excellent straightness, and is suitable as light for illuminating the illuminated areas Z1 and Z2 with high accuracy. In the example illustrated in FIG. 2, the illumination device 10 includes a single light source 15, but may include a plurality of light sources 15.

  Next, the shaping optical system 30 will be described. The shaping optical system 30 is disposed between the light source 15 and the diffractive optical element 40 along the optical path from the light source 15 to the diffractive optical element 40. The shaping optical system 30 shapes the light emitted from the light source 15. In other words, the shaping optical system 30 shapes the shape of a cross section perpendicular to the optical axis x of the light emitted from the light source 15 and the three-dimensional shape of the light flux of the light. In the illustrated example, the shaping optical system 30 shapes the light emitted from the light source 15 into a broadened parallel light beam. As shown in FIG. 2, the shaping optical system 30 includes a lens 31 and a collimating lens 32 in the order along the optical path of the light emitted from the light source 15. The lens 31 shapes the light emitted from the light source 15 into a divergent light beam. The collimating lens 32 reshapes the divergent light beam generated by the lens 31 into a parallel light beam. In addition, when the illuminating device 10 has a plurality of light sources, a plurality of shaping optical systems may be provided corresponding to each of the plurality of light sources.

  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 emitted from the light source 15. The illustrated diffractive optical element 40 diffracts the light from the light source 15 and directs it to the projection optical system 50.

  In the illustrated example, the diffractive optical element 40 includes a first element diffractive optical element 41 and a second element diffractive optical element 42. The first element diffractive optical element 41 diffracts part of the light from the collimating lens 32 and directs it to the projection optical system 50. The second element diffractive optical element 42 diffracts another part of the light from the collimator lens 32 and directs it to the projection optical system 50.

  As an example, each of the element diffractive optical elements 41 and 42 is configured as a hologram recording medium on which an interference fringe pattern is recorded. By adjusting the interference fringe pattern variously, the traveling direction of the light diffracted by each element diffractive optical element 41, 42, in other words, the traveling direction of the light diffused by each element diffractive optical element 41, 42 can be controlled. can do.

  Each of the element diffractive optical elements 41 and 42 can be manufactured using, for example, scattered light from a real scattering plate as object light. More specifically, when the hologram photosensitive material that is the base material of the element diffractive optical elements 41 and 42 is irradiated with reference light and object light made of coherent light having coherence with each other, interference fringes due to interference of these lights are generated. Element diffractive optical elements 41 and 42 are formed on the hologram photosensitive material. As reference light, laser light which is coherent light is used, and as object light, for example, scattered light from an isotropic scattering plate available at low cost is used.

  By irradiating laser light toward the element diffractive optical elements 41 and 42 so that the optical path of the reference light used when the element diffractive optical elements 41 and 42 are produced travels in the opposite direction, the element diffractive optical elements 41 and 42 are A reproduced image of the scattering plate is generated at the position of the scattering plate, which is the source of the object light used in the production. If the scattering plate which is the source of the object light used when the element diffractive optical elements 41 and 42 are produced has a uniform surface scattering, a reproduced image of the scattering plate obtained by the element diffractive optical elements 41 and 42 is obtained. Even uniform surface illumination.

  In addition, the complicated interference fringe pattern formed on the element diffractive optical elements 41 and 42 is not formed by using the actual object light and reference light, but the planned wavelength and incident direction of the reproduction illumination light and the reproduction. It is possible to design using a computer based on the shape and position of the image to be performed. The element diffractive optical elements 41 and 42 thus obtained are also called computer generated holograms (CGH).

  Further, a Fourier transform hologram having the same diffusion angle characteristic at each point on the element diffractive optical elements 41 and 42 may be formed by computer synthesis.

  A specific form of the element diffractive optical elements 41 and 42 may be a volume hologram recording medium using a photopolymer, or a volume hologram recording medium of a type that records using a photosensitive medium containing a silver salt material. It may be a relief type (emboss type) hologram recording medium. The element diffractive optical elements 41 and 42 may be transmissive or reflective.

  In addition, when the illuminating device 10 has a plurality of light sources, a plurality of diffractive optical elements may be provided corresponding to each of the plurality of light sources.

  The projection optical system 50 reflects or refracts the light diffracted by the diffractive optical element 40 and directs it toward the projection surface S (installation surface in the illustrated example). More specifically, the projection optical system 50 is diffracted by the first-order diffracted light (hereinafter also referred to as “first diffracted light”) L11 diffracted by the first element diffractive optical element 41 and the second element diffractive optical element 42. The first-order diffracted light (hereinafter also referred to as “second diffracted light”) L12 is directed in a different direction. In the element diffractive optical elements 41 and 42 such as hologram elements, second-order or higher-order diffracted light (hereinafter also referred to as “high-order diffracted light”) other than the first-order diffracted lights L11 and L12 is used as diffracted light. Arise. The projection optical system 50 directs at least the first-order diffracted lights L11 and L12 of the diffracted light incident on the projection optical system 50 in different directions.

  In the illustrated example, the projection optical system 50 is a reflective element having a reflective surface that reflects light. The projection optical system 50 is made of a material having a high reflectance such as metal at least on the reflection surface thereof. In particular, in the example shown in the figure, the projection optical system 50 has a specular reflection function, at least the reflection surface of which is made of silver.

  As described above, the projection optical system 50 changes the first diffracted light L11 diffracted by the first element diffractive optical element 41 and the second diffracted light L12 diffracted by the second element diffractive optical element 42 in different directions. Turn to. In the example shown in FIG. 2, the projection optical system 50 is configured as a so-called polygonal mirror having a plurality of reflecting surfaces. More specifically, the projection optical system 50 has a triangular prism shape as a whole, and two of the three side surfaces form a reflecting surface. One of the two reflecting surfaces is the first reflecting surface 51 on which the first diffracted light L11 is incident, and directs the first diffracted light L11 in the first direction. The other reflecting surface is the second reflecting surface 52 on which the second diffracted light L12 is incident, and directs the second diffracted light L12 in a second direction different from the first direction. As the projection optical system 50 capable of directing the first diffracted light L11 and the second diffracted light L12 in different directions, various things such as a concave mirror, a convex mirror, a plane mirror, and a prism can be adopted in addition to the polygonal mirror. It is.

  In the example shown in FIG. 2, the direction of the first reflecting surface 51 is changed by changing the traveling direction of the first diffracted light L11 by an angle exceeding 90 °, and the first diffracted light L11 is changed to the first object on the projection surface S. It is set to face the illumination area Z1. Further, the direction of the second reflecting surface 52 is such that the traveling direction of the second diffracted light L12 is changed by an angle exceeding 90 °, and the second diffracted light L12 is directed to the second illuminated region Z2 on the projection surface S. Is set to

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

  The light emitted from the light source 15 first enters the shaping optical system 30. The shaping optical system 30 expands the light emitted from the light source 15. That is, the shaping optical system 30 shapes the light from the light source 15 so that the area occupied by light in the cross section orthogonal to the optical axis x is widened. In the illustrated example, the shaping optical system 30 includes a lens 31 and a collimating lens 32. As shown in FIG. 2, the lens 31 of the shaping optical system 30 divides the light emitted from the light source 15 and converts it into a divergent light beam. The collimating lens 32 of the shaping optical system 30 collimates the divergent light beam into a parallel light beam.

  The light shaped by the shaping optical system 30 is then directed to the diffractive optical element 40. The element diffractive optical elements 41 and 42 of the diffractive optical element 40 record interference fringes corresponding to the center wavelength of the light emitted from the light source 15, and light incident from a certain direction is highly efficiently directed to a desired direction. Can be diffracted. In the illustrated example, the first element diffractive optical element 41 diffracts part of the light emitted from the light source 15 and diffuses the diffracted light toward the projection optical system 50. The second element diffractive optical element 42 diffracts another part of the light emitted from the light source 15 and diffuses the diffracted light toward the projection optical system 50.

  The light incident on the reflecting surfaces 51 and 52 of the projection optical system 50 is reflected and changes its traveling direction. In particular, the first diffracted light L11 incident on the first reflecting surface 51 is reflected and changes its traveling direction at an angle exceeding 90 °. Then, the first diffracted light L11 reflected by the first reflecting surface 51 passes through the opening 61 provided in the cylindrical casing 60 and enters the first illuminated area Z1 on the projection surface S. Further, the second diffracted light L12 incident on the second reflecting surface 52 is reflected and changes its traveling direction at an angle exceeding 90 °. The second diffracted light L12 reflected by the second reflecting surface 52 travels in a different direction from the first diffracted light L11 reflected by the first reflecting surface 51. Then, the second diffracted light L12 passes through an opening 61 provided in the cylindrical housing 60 and enters a second illuminated area Z2 different from the first illuminated area Z1 on the projection surface S. In the illustrated example, the first illuminated area Z1 and the second illuminated area Z2 are illuminated with a linear pattern extending in a different direction from the illumination device 10.

  According to the first embodiment as described above, the illumination device 10 includes the light source 15 that emits light, the diffractive optical element 40 that diffracts the light emitted from the light source 15, and the light diffracted by the diffractive optical element 40. A projection optical system 50 that reflects or refracts the light toward the projection surface S. Then, the projection optical system 50 directs a part L11 of the first-order diffracted light diffracted by the diffractive optical element 40 and another part L12 in different directions.

  Such an illuminating device 10 can project light in a plurality of directions to illuminate a plurality of illuminated areas Z1 and Z2.

  In the first embodiment, the diffractive optical element 40 diffracts the first element diffractive optical element 41 that diffracts part of the light emitted from the light source 15 and the other part of the light emitted from the light source 15. A second element diffractive optical element 42. Then, the projection optical system 50 includes the first diffracted light L11 diffracted by the first element diffractive optical element 41 and the second diffracted light diffracted by the second element diffractive optical element 42. The light L12 is directed in a different direction. According to such an illuminating device 10, it is easy to illuminate each of the plurality of illuminated areas Z1, Z2 with a desired pattern with high accuracy.

  In the first embodiment, the projection optical system 50 is a reflective element or a prism. In this case, it is easy to realize the projection optical system 50 that reflects or refracts the first diffracted light L11 and the second diffracted light L12 and directs them in different directions.

  In the first embodiment, a collimator lens 32 is further provided between the light source 15 and the diffractive optical element 40 along the optical path from the light source 15 to the diffractive optical element 40. Thereby, since the collimated light enters the diffractive optical element 40, it is easy for the diffractive optical element 40 to diffract the first diffracted light L11 and the second diffracted light L12 in a desired direction with high accuracy.

  In the first embodiment, the projection optical system 50 changes the traveling direction of a part L11 of the first-order diffracted light diffracted by the diffractive optical element 40 at an angle exceeding 90 °, and the diffractive optical element 40 The traveling direction of the other part L12 of the diffracted first-order diffracted light is changed at an angle exceeding 90 °. In this case, for example, as illustrated in FIGS. 1 and 2, the illumination device 10 can illuminate the installation surface as a projection surface S.

  In the first embodiment, the lighting device 10 is housed in a cylindrical housing 60. In this case, it is easy to make the illumination device 10 stand on the projection surface S. Furthermore, as shown in FIG. 4 to be described later, it is easy to install a part thereof in the ground, under the floor, or in water.

  Note that various modifications can be made to the first embodiment described above. Hereinafter, some modifications will be described with reference to the drawings. In the following description and the drawings used in the following description, the same reference numerals as those used for the corresponding parts in the first embodiment are used for the parts that can be configured in the same manner as in the first embodiment. It will be used, and redundant description will be omitted.

<Modification 1>
In the first embodiment described above, for example, consider the case where the illumination device 10 illuminates the first illuminated area Z1 and the second illuminated area Z2 extending in a straight line. In this case, in the illuminated areas Z1 and Z2, the closer to the illumination device 10, the clearer and brighter pattern illumination the better the visibility, and the farther away from the illumination device 10, the projected pattern becomes blurred and the illumination becomes darker and the visibility becomes worse. In consideration, regions illuminated with a clear and bright pattern with good visibility (and thus neatly) by the light L11 that illuminates the illuminated region Z1 and the light L12 that illuminates the illuminated region Z2, respectively, are points E11 shown in FIG. To E12 and from E21 to E22. Therefore, the illuminating device 10 can be used to illuminate a region having a length L10 extending from the point E12 on one side of the illuminating device 10 to the point E22 on the other side with a clear and bright pattern with high visibility.

  On the other hand, when illuminating the illuminated area Z500 with the illumination device 500 that projects light only in a single direction using a light source that emits light of the same radiant flux as the light source 15 of the illumination device 10, In the region Z500, the closer to the illumination device 500, the clearer and brighter pattern illumination the better the visibility, and the farther away from the illumination device 500, the more the projection pattern is blurred and the darker illumination causes poor visibility. The region illuminated with a clear and bright pattern with good visibility by the light L500 that illuminates the light is a region having a length L500 from the point E51 to the point E52 shown in FIG.

  Thus, the illuminating device 10 can be used to illuminate a region having a length L10 extending from the point E12 on one side of the illuminating device 10 to the point E22 on the other side with a clear and bright pattern with good visibility. On the other hand, the region in which the illumination device 500 can illuminate with a clear and bright pattern with high visibility is only the region of the length L500 extending from the point E51 to the point E52 on one side of the illumination device 500. In general, the length L10 is significantly longer than the length L500. That is, the illuminating device 10 can be used to illuminate a longer region with a clear and bright pattern with good visibility as compared with the illuminating device 500. In other words, in the case of illuminating a region having a length L10 longer than the length L500, if the illumination device 10 is arranged at an intermediate point of the region and light is projected from the intermediate point, the illuminator in the region From the point 10 to the points E12 and E22 farthest away, it is possible to illuminate with a clear and bright pattern with good visibility.

  In the description of the first modification described above, the case where the lighting device 10 illuminates the first illuminated area Z1 and the second illuminated area Z2 extending in a straight line has been described, but the present invention is not limited thereto. That is, the first illuminated area Z1 and the second illuminated area Z2 do not have to extend on a strict straight line. The first illuminated area Z1 and the second illuminated area Z2 may extend in directions intersecting each other, such as an area Z1b and an area Z2a shown in FIG. Even in this case, if the first illuminated area Z1 and the second illuminated area Z2 extend along a straight line as a whole, the first illuminated area Z1 and the second illuminated area Z2 extend in a straight line. The same effect can be obtained as in the case of.

  According to Modification 1 as described above, the projection optical system 50 reflects or refracts the part L11 and the other part L12 of the first-order diffracted light diffracted by the diffractive optical element 40, and each of the projection surfaces S The light is directed toward the first illuminated area Z1 and the second illuminated area Z2. The first illuminated area Z1 and the second illuminated area Z2 extend along a straight line as a whole. In particular, in the illustrated example, the first illuminated area Z1 and the second illuminated area Z2 extend in a straight line. In this case, the illuminating device 10 can illuminate a region with a length L10 extending from the point E12 on one side of the illuminating device 10 to the point E22 on the other side with a clear and bright pattern with good visibility (and thus neatly). However, the length L10 is such that the illumination device 500 that illuminates only a single direction using a light source that emits light of the same radiant flux as the light source 15 of the illumination device 10 illuminates with a clear and bright pattern with good visibility. It is significantly longer than the possible region length L500.

<Modification 2>
In the first embodiment described above, the case where the diffractive optical element 40 includes the two element diffractive optical elements 41 and 42 and the illumination device 10 illuminates the two illuminated areas Z1 and Z2 has been described. Not limited to. For example, as shown in FIG. 4, the diffractive optical element may include three or more element diffractive optical elements. In this case, the illumination device can illuminate three or more illuminated areas by projecting light in three or more directions.

  The illumination device 100 shown in FIG. 4 projects light in three directions to illuminate the three illuminated areas Z1, Z2, and Z3. In the illumination device 100 shown in FIG. 4, the diffractive optical element 140 has three element diffractive optical elements 41, 42, and 43, and the projection optical system 150 has three reflective surfaces 51, 52, and 53. Yes. Other configurations are substantially the same as those of the lighting device 10 shown in FIG. In FIG. 3, the casing 60 is not shown for easy understanding.

  The diffractive optical element 140 includes a third element diffractive optical element 43 in addition to the first element diffractive optical element 41 and the second element diffractive optical element 42. Similarly to the other element diffractive optical elements 41 and 42, the third element diffractive optical element 43 is configured as a hologram recording medium on which, for example, an interference fringe pattern is recorded. In the diffractive optical element 140 shown in FIG. 4, the first element diffractive optical element 41 diffracts part of the light from the collimating lens 32 and directs it to the projection optical system 150. The second element diffractive optical element 42 diffracts the other part of the light and directs it to the projection optical system 150. The third element diffractive optical element 43 diffracts another part of the light and directs it to the projection optical system 150.

  The projection optical system 150 has a third reflecting surface 53 in addition to the first reflecting surface 51 and the second reflecting surface 52. In the example shown in FIG. 4, the projection optical system 150 has a triangular pyramid shape. Three surfaces other than the bottom surface have a reflection function, and form reflection surfaces 51, 52, and 53, respectively. The third reflecting surface 53 is a first-order diffracted light (hereinafter also referred to as “third diffracted light”) L13 diffracted by the third element diffractive optical element 43, whichever of the first diffracted light L11 and the second diffracted light L12. In a different third direction. The third reflecting surface 53 changes the traveling direction of the third diffracted light L13 at an angle exceeding 90 °, and directs the third diffracted light L13 toward the third illuminated region Z3 on the projection surface S. . In addition to the pyramid shape, various shapes such as a conical shape can be adopted as the shape of the projection optical system 150.

<Modification 3>
In the above-described first embodiment, the case where the illumination device 10 is installed on the projection plane S has been described. However, for example, when it is desired to make the lighting device 10 appear small, a part of the lighting device 10 may be disposed below the projection surface S, that is, in the ground or under the floor, as shown in FIG. Moreover, when making the water surface into the projection surface S, the illuminating device 10 may be partially arrange | positioned in water.

<Modification 4>
In 1st Embodiment mentioned above, although the case where the illuminating device 10 was installed in the ground or a floor surface was demonstrated, it is not restricted to this. The lighting device 10 can be used as a lighting device for a mobile object such as a car or a ship in various fields.

  In the example illustrated in FIG. 6, the lighting device 10 is installed in the vehicle C and projects light in two directions, the lower right front of the vehicle C and the lower left front of the vehicle C. And the illuminating device 10 illuminates the 1st to-be-illuminated area Z1 located in the right front of the vehicle C, and the 2nd to-be-illuminated area Z2 located in the left front.

  Further, in the example shown in FIG. 7, the lighting device 10 is installed in the vehicle C and emits light in two directions that are at the front and lower sides of the vehicle C but at different angles with respect to the ground or floor surface that is the projection surface S. Project. The lighting device 10 illuminates the illuminated area in the near field and the illuminated area in the far field of the vehicle C.

  6 and 7 is similar to the illumination device described above, the light source 15, the shaping optical system 30, the diffractive optical element 40 including a plurality of element diffractive optical elements, and the projection optics. A system 50. The projection optical system 50 is formed by a prism. This prism has a first prism surface 51a that changes the optical path of the first diffracted light L11 by refraction, and is inclined with respect to the first prism surface 51a, and the optical path of the second diffracted light L12 is refracted by refraction. And a second prism surface 52a oriented in a direction different from the optical path.

<Modification 5>
Although the case where the projection optical system is a reflecting element or a prism has been described in the first embodiment and the modification described above, the present invention is not limited to this. The projection optical system may be a projection diffractive optical element that has a diffractive action on the first-order diffracted light diffracted by the diffractive optical element 40.

  Hereinafter, Modification 5 will be described with reference to FIG. The illumination device 200 shown in FIG. 8 differs from the illumination device 10 shown in FIG. 2 in that the projection optical system is a projection diffractive optical element 250.

  As an example, the projection diffractive optical element 250 is configured as a hologram recording medium on which an interference fringe pattern is recorded. By adjusting the interference fringe pattern in various ways, the traveling direction of the light diffracted by the projection diffractive optical element 250, in other words, the traveling direction of the light diffused by the projection diffractive optical element 250 can be controlled. . The projection diffractive optical element 250 can be manufactured in the same manner as the element diffractive optical elements 41 and 42 of the diffractive optical element 40.

  In the example shown in FIG. 8, the projection diffractive optical element 250 includes a first projection diffractive region 251 on which the first diffracted light L11 that is the first-order diffracted light diffracted by the first element diffractive optical element 41 is incident, And a second projection diffraction region 252 on which the second diffracted light L12 that is the first-order diffracted light diffracted by the element diffractive optical element 42 is incident. Then, the projection diffractive optical element 250 directs the first diffracted light L11 from the first element diffractive optical element 41 in a direction corresponding to the diffraction characteristics in the first projection diffractive region 251. The projection diffractive optical element 250 directs the second diffracted light L12 from the second element diffractive optical element 42 in a direction according to the diffraction characteristics in the second projection diffractive region 252.

  In the illustrated example, the first projection diffraction region 251 diffracts the first diffracted light L11 from the first element diffractive optical element 41 and directs it to the first illuminated region Z1. Further, the second projection diffraction area 252 diffracts the second diffracted light L12 from the second element diffractive optical element 42 and directs it to the second illuminated area Z2.

  When such a projection diffractive optical element 250 is used as a projection optical system, the illuminated areas Z1 and Z2 illuminated by the illumination device 200 are areas corresponding to the diffraction characteristics of the projection diffractive optical element 250. Therefore, by replacing the projection diffractive optical element 250 with another projection diffractive optical element having diffraction characteristics different from that of the projection diffractive optical element 250, the illuminated areas Z1 and Z2 illuminated by the illumination device 200 are used. Can be changed from the illuminated areas Z1a, Z2a shown in FIG. 9 to the illuminated areas Z1b, Z2b, for example.

  As described above, according to the fifth modification, the projection optical system 250 is a projection diffractive optical element that diffracts the lights L11 and L12 diffracted by the diffractive optical element 40. Thus, by replacing the projection diffractive optical element 250 with another projection diffractive optical element having a diffraction characteristic different from that of the projection diffractive optical element 250, the illuminated region Z <b> 1 illuminated by the illumination device 200 is obtained. Z2 can be changed.

<Modification 6>
In the modified example 5 described above, the case where the first projection diffraction area 251 and the second projection diffraction area 252 of the projection diffractive optical element 250 are integrally formed has been described. Not limited.

  In the example shown in FIG. 10, the first projection diffraction region 251 and the second projection diffraction region 252 of the projection diffractive optical element 250 are configured as separate bodies. More specifically, the projection diffractive optical element 250 includes a first projection element diffractive optical element 253 on which the first-order diffracted light diffracted by the first element diffractive optical element 41 is incident, and a second element diffractive optical element 42. And a second projection element diffractive optical element 254 on which the diffracted first-order diffracted light is incident. The first projection element diffractive optical element 253 diffracts the first diffracted light L11 which is the first-order diffracted light from the first element diffractive optical element 41, and more specifically, in the first direction, more specifically, the first illumination target. Turn to the area Z1. The second projection element diffractive optical element 254 diffracts the second diffracted light L12 that is the first-order diffracted light from the second element diffractive optical element 42, and in a second direction different from the first direction, More specifically, it is directed to the second illuminated area Z2.

  When such a projection diffractive optical element 250 is used as a projection optical system, one of the first and second projection element diffractive optical elements 253 and 254 is different from the projection element diffractive optical element 253 and 254. By replacing with another projection element diffractive optical element having diffraction characteristics, only one of the first and second illuminated areas Z1, Z2 is changed from the illuminated area Z1a shown in FIG. 9 to the illuminated area Z1b, for example. Alternatively, the illumination area Z2a can be changed to the illumination area Z2b.

  As described above, according to the sixth modification, the diffractive optical element 40 includes the first element diffractive optical element 41 that diffracts part of the light emitted from the light source 15 and the other part of the light emitted from the light source 15. And a second element diffractive optical element 41 that diffracts. The projection diffractive optical element 250 diffracts the first diffracted light L11 that is the first-order diffracted light diffracted by the first element diffractive optical element 41 and directs the first diffracted element diffractive optical element 253 in the first direction. A second projection element diffractive optical element 254 that diffracts the second diffracted light L12, which is the first-order diffracted light diffracted by the second element diffractive optical element 42, and directs the second diffracted light L12 in a second direction different from the first direction; Have. Accordingly, one of the first and second projection element diffractive optical elements 253 and 254 is replaced with another projection element diffractive optical element having diffraction characteristics different from those of the projection element diffractive optical elements 253 and 254. Thus, only one of the first and second illuminated areas Z1, Z2 can be changed.

<Modification 7>
Although the case where the diffractive optical element 40 has a plurality of element diffractive optical elements has been described in the first embodiment and the first to sixth modifications, the present invention is not limited to this. The diffractive optical element 40 may be composed of a single element diffractive optical element.

  Hereinafter, the modified example 7 will be described with reference to FIG. The illuminating device 300 shown in FIG. 11 differs from the illuminating device shown in FIG. 2 in that the diffractive optical element 40 is composed of a single element diffractive optical element. Further, the projection optical system 350 is different in that it includes a half mirror 351 and a reflective element 352.

  In the example shown in FIG. 11, the diffractive optical element 40 diffracts all of the light emitted from the light source 15.

  The half mirror 351 and the reflective element 352 of the projection optical system 350 are disposed on the optical path of the first-order diffracted light L1 diffracted by the diffractive optical element 40. The half mirror 351 is disposed between the diffractive optical element 40 and the reflective element 352 along the optical path from the diffractive optical element 40 to the reflective element 352.

  The half mirror 351 reflects a part L11 of the first-order diffracted light L1 diffracted by the diffractive optical element 340 and transmits the other part L12 in the first direction. The reflective element 352 reflects the other part L12 of the first-order diffracted light L1 transmitted through the half mirror 351 and directs it in the second direction. In the illustrated example, the light L11 reflected by the half mirror 351 is directed to the first illuminated area Z1, and the light L12 reflected by the reflective element 352 is directed to the second illuminated area Z2.

  Also with such an illuminating device 300, it is possible to illuminate the plurality of illuminated areas Z1 and Z2 by directing the light emitted from the light source 15 in a plurality of directions. In the illustrated example, the diffractive optical element 40 is configured by a single element diffractive optical element, but is not limited thereto. Similar to the example shown in FIG. 2, the diffractive optical element 40 may include a plurality of element diffractive optical elements 41 and 42.

  As described above, according to the modified example 7, the projection optical system 350 includes the half mirror 351 that reflects the part L11 of the first-order diffracted light L1 diffracted by the diffractive optical element 40 and transmits the other part L12, and the half mirror 351. And a reflective element 352 that reflects the other part L12 of the first-order diffracted light L1 that has passed through the mirror 351. In such an illuminating device 300, the projection optical system 350 directs the part L11 of the first-order diffracted light L1 diffracted by the diffractive optical element 40 and the other part L12 in different directions. For this reason, the illuminating device 300 can illuminate the to-be-illuminated areas Z1 and Z2 by projecting light in a plurality of directions.

<Modification 8>
In the modifications 5 and 6 described above, the case where the illuminated areas Z1 and Z2 are moved by exchanging part or all of the projection diffractive optical element 250 has been described, but the present invention is not limited to this. For example, the housing 60 that houses the lighting devices 10, 100, 200, and 300 is placed on a rotatable pedestal so as to be rotatable, and the housing 60 is placed in the lighting devices 10, 100, 200, and so on. Z1, Z2, and Z3 may be moved in the illuminated area by rotating together with 300. Alternatively, the illumination devices 10, 100, 200, and 300 in the housing 60 are rotatably supported, and the illumination devices 10, 100, 200, and 300 are rotated to move the illuminated areas Z1, Z2, and Z3. May be. Alternatively, the illuminated areas Z1, Z2, and Z3 may be moved by rotating the diffractive optical elements 40 and 140 while supporting the diffractive optical elements 40 and 140 in a rotatable manner. Alternatively, the illumination regions Z1, Z2, and Z3 may be moved by supporting the projection optical systems 50, 150, 250, and 350 in a rotatable manner and rotating the projection optical systems 50, 150, 250, and 350. Alternatively, the diffractive optical elements 40, 140 and the projection optical systems 50, 150, 250, 350 are rotatably supported, and the projection optical systems 50, 150, 250, 350 are rotated together with the diffractive optical elements 40, 140, so The illumination areas Z1, Z2, and Z3 may be moved.

<Second Embodiment>
Next, a second embodiment will be described with reference to FIG. In the following description and the drawings used in the following description, the same reference numerals as those used for the corresponding parts in the first embodiment are used for the parts that can be configured in the same manner as in the first embodiment. It will be used, and redundant description will be omitted.

  First, in the illumination device shown in FIGS. 1 and 2, a part of the light from the light source passes through the diffractive optical element without being diffracted by the diffractive optical element, and becomes so-called zero-order light. If such 0th-order light is reflected or refracted by the projection optical system, it may cause a safety problem such as entering the eyes of the observer. In addition, when zero-order light enters the illuminated area, abnormal areas such as dot-like areas, linear areas, and planar areas where brightness (luminance) increases sharply compared to the surrounding area are illuminated areas. Will occur within.

  Further, as described above, in an element diffractive optical element such as a hologram element, second-order or higher-order diffracted light is generated as diffracted light in addition to the first-order diffracted light. If high-order diffracted light is reflected or refracted by the projection optical system, it may cause a safety problem such as entering the eyes of the observer. In addition, when higher-order diffracted light is projected onto the projection surface, there is a possibility that a region other than the illuminated region is illuminated and it becomes difficult to recognize the illuminated region.

  In order to solve such a problem, the second embodiment is devised to prevent 0th-order light and higher-order diffracted light from entering the projection optical system. Hereinafter, the illumination device 400 of the second embodiment will be described in more detail with reference to FIG.

  Compared with the illuminating device 10 shown in FIG. 1, the illuminating device 400 shown in FIG. 12 includes a first lens 71, a second lens 72, a zero-order light mask 81, and The only difference is that the high-order diffracted light mask 82 is arranged, and the other configuration is substantially the same as that of the illumination device 10 shown in FIGS. 1 and 2.

  The first lens 71 and the second lens 72 are disposed between the diffractive optical element 40 and the projection optical system 50 along the optical path from the diffractive optical element 40 to the projection optical system 50. More specifically, the diffractive optical element 40, the projection optical system 50, the first lens 71, and the second lens 72 are arranged as follows.

  The first lens 71 is separated from the diffractive optical element 40 by the focal length f1 of the first lens 71 between the diffractive optical element 40 and the projection optical system 50 along the optical path from the diffractive optical element 40 to the projection optical system 50. Are arranged. The second lens 72 is disposed between the first lens 71 and the projection optical system 50 along the optical path from the first lens 71 to the projection optical system 50. The second lens 72 is arranged away from the first lens 71 by the sum of the focal length f1 of the first lens 71 and the focal length f2 of the second lens 72. Note that the distance between the second lens 72 and the projection optical system 50 is not particularly limited. In the example shown in FIG. 12, the second lens 72 is arranged at a focal distance f2 of the second lens 72 from the incident positions of the first diffracted light L11 and the second diffracted light L12 in the projection optical system 50. The distance between the second lens 72 and the projection optical system 50 may be larger or smaller than the focal length f2. In the example shown in FIG. 12, the first lens 71, the second lens 72, and the diffractive optical element 40 form a 4f optical system.

  The first lens 71 transmits the 0th-order light L01 transmitted through the first element diffractive optical element 41 and the 0th-order light L02 transmitted through the second element diffractive optical element 42 to a point a on the focal plane P of the first lens 71. Turn. The first lens 71 travels in the traveling direction of the first-order diffracted light (first diffracted light) L11 and the higher-order diffracted light L21 in the first element diffractive optical element 41, and the 0th-order light L01 travels through the first lens 71. Change to a direction parallel to the direction. The first lens 71 travels in the traveling direction of the first-order diffracted light (second diffracted light) L12 and the higher-order diffracted light L22 in the second element diffractive optical element 42, and the 0th-order light L02 that has passed through the first lens 71 travels. Change to a direction parallel to the direction. Thereby, as shown in FIG. 12, the incident positions of the 0th-order light L01, L02, the 1st-order diffracted light L11, L12, and the high-order diffracted light L21, L22 on the focal plane P are the peripheral regions of the point a and the point a, respectively. In other words, the area is collected outside the peripheral area.

  The second lens 72 directs light that has passed through a region between a 0th-order light mask 81 and a higher-order diffracted light mask 82 described later, that is, the first diffracted light L11 and the second diffracted light L12 toward the projection optical system 50, respectively. Collect light.

  The zero-order light mask 81 is disposed between the first lens 71 and the second lens 72 along the optical path from the first lens 71 to the second lens 72. The zero-order light mask 81 is disposed on the focal plane P of the first lens 71, separated from the first lens 71 by the focal length f <b> 1 of the first lens 71. The 0th-order light mask 81 overlaps with the position a where the 0th-order lights L01 and L02 of the focal plane P are incident, but is disposed at a position that does not overlap with the positions where the first-order diffracted lights L11 and L12 and the higher-order diffracted lights L21 and L22 are incident. Is done. As a result, the 0th-order light mask 81 can block only the 0th-order lights L01 and L02 out of the diffracted light from the diffractive optical element 40.

  The high-order diffracted light mask 82 is also disposed on the same plane as the zero-order light mask 81. That is, the high-order diffracted light mask 82 is disposed between the first lens 71 and the second lens 72 along the optical path from the first lens 71 to the second lens 72. The high-order diffracted light mask 82 is disposed on the focal plane P of the first lens 71 so as to be separated from the first lens 71 by the focal length f1 of the first lens 71. The high-order diffracted light mask 82 is disposed at a position where the high-order diffracted lights L21 and L22 on the focal plane P are incident, but not at the positions where the zero-order diffracted lights L01 and L02 and the first-order diffracted lights L11 and L12 are incident. The As a result, the high-order diffracted light mask 82 can block only the high-order diffracted lights L21 and L22 out of the diffracted light from the diffractive optical element 40.

  In the illustrated example, the 0th-order light mask 81 and the higher-order diffracted light mask 82 are plate-like members that absorb the 0th-order light L01 and L02 and the higher-order diffracted lights L21 and L22, respectively, but are not limited thereto. For example, the 0th-order light mask 81 and the high-order diffracted light mask 82 may direct the 0th-order light L01, L02 and the high-order diffracted light L21, L22 to other than the projection optical system 50, respectively.

  Next, the operation of the lighting device 400 having the above-described configuration will be described.

  The light emitted from the light source 15 first enters the shaping optical system 30. The shaping optical system 30 expands the light emitted from the light source 15.

  The light shaped by the shaping optical system 30 is then directed to the diffractive optical element 40. The first element diffractive optical element 41 diffracts part of the light emitted from the light source 15. The second element diffractive optical element 42 diffracts another part of the light emitted from the light source 15.

  The light diffracted by the diffractive optical element 40 is then directed to the first lens 71. In addition, the 0th-order lights L01 and L02 that have passed through the element diffractive optical elements 41 and 42 also travel toward the first lens 71. In the first lens 71, the 0th-order lights L01 and L02 are directed to a point a on the focal plane P of the first lens 71. In the first lens 71, the first-order diffracted light L11 and the higher-order diffracted light L21 from the first element diffractive optical element 41 are directed in a direction parallel to the traveling direction of the zero-order light L01. In the first lens 71, the first-order diffracted light L12 and the higher-order diffracted light L22 from the second element diffractive optical element 42 are directed in a direction parallel to the traveling direction of the zero-order light L02.

  Of the light that has passed through the first lens 71, the 0th-order light L01 and L02 enter the 0th-order light mask 81. The high-order diffracted lights L21 and L22 are incident on the high-order diffracted light mask 82. On the other hand, the first-order diffracted light (first diffracted light and second diffracted light) L11 and L12 passes through the region between the 0th-order diffracted light mask 81 and the higher-order diffracted light mask 82, and maintains the traveling direction thereof. The light enters the lens 72.

  The first diffracted light L11 and the second diffracted light L12 incident on the second lens 72 are condensed toward a point on the first reflecting surface 51 and a point on the second reflecting surface 52 of the projection optical system 50, respectively. .

  The first diffracted light L11 incident on the first reflecting surface 51 is reflected and changes its traveling direction at an angle exceeding 90 °. Then, the first diffracted light L11 reflected by the first reflecting surface 51 passes through the opening 61 provided in the cylindrical casing 60 and enters the first illuminated area Z1 on the projection surface S. Further, the second diffracted light L12 incident on the second reflecting surface 52 is reflected and changes its traveling direction at an angle exceeding 90 °. At this time, the second diffracted light L12 reflected by the second reflecting surface 52 travels in a different direction from the first diffracted light L11 reflected by the first reflecting surface 51. Then, the second diffracted light L12 reflected by the second reflecting surface 52 passes through the opening 61 provided in the cylindrical casing 60, and is different from the first illuminated area Z1 on the projection surface S. It enters the illuminated area Z2.

  According to the second embodiment as described above, the illumination device 400 is disposed between the diffractive optical element 40 and the projection optical system 50 along the optical path from the diffractive optical element 40 to the projection optical system 50. A first lens 71 that is disposed away from the diffractive optical element 40 by the focal length f1 of the first lens 71, and a first lens along the optical path from the first lens 71 to the projection optical system 50. The second lens 72 is disposed between the lens 71 and the projection optical system 50 and is separated from the first lens 71 by the sum of the focal length f1 of the first lens 71 and the focal length f2 of the second lens 72. The second lens 72 disposed between the first lens 71 and the second lens 72 along the optical path from the first lens 71 to the second lens 72, and the zero-order light from the diffractive optical element 40. 0th order light blocking L01 and L02 Further includes a disk 81, a.

  According to such an illuminating device 400, it is possible to prevent the 0th-order light L01 and L02 transmitted through the diffractive optical element 40 from being reflected or refracted by the projection optical system 50. As a result, the 0th-order lights L01 and L02 enter the eyes of the observer to cause safety problems, or the 0th-order light enters the illuminated area and the brightness (luminance) is drastically compared with the surroundings. It is possible to prevent the rising abnormal area from occurring in the illuminated area. Further, since the first lens 71 is disposed away from the diffractive optical element 40 by the above-mentioned distance, the 0th-order light L01, L02, the first-order diffracted light L11, L12, and the higher-order diffracted light L21, The path of L22 is adjusted, and it is easy to arrange the 0th-order light mask 81 so as to block only the 0th-order lights L01 and L02. Further, since the second lens 72 is disposed away from the first lens 71 by the above-described distance, the characteristics of the first diffracted light L11 and the second diffracted light L12 that have passed through the first lens 71 and the second lens 72 are displayed. In accordance with the characteristics of the first diffracted light L11 and the second diffracted light L12 in the diffractive optical element 40. As a result, it is possible to illuminate the illuminated areas Z1 and Z2 with a desired pattern according to the diffraction characteristics of the diffractive optical element 40 (for example, the interference fringe pattern recorded on the element diffractive optical elements 41 and 42).

  Further, according to the second embodiment as described above, the illumination device 400 is disposed between the diffractive optical element 40 and the projection optical system 50 along the optical path from the diffractive optical element 40 to the projection optical system 50. The first lens 71 is a first lens 71 disposed away from the diffractive optical element 40 by the focal length f1 of the first lens 71, and along the optical path from the first lens 71 to the projection optical system 50. A second lens 72 disposed between the first lens 71 and the projection optical system 50, which is the sum of the focal length f1 of the first lens 71 and the focal length f2 of the second lens 72 from the first lens 71. The second lens 72 that is spaced apart and the first lens 71 and the second lens 72 that are disposed along the optical path from the first lens 71 to the second lens 72. Blocks the next diffracted beams L21 and L22 That a high-order diffracted light masks 82, further comprising a.

  According to such an illumination device 400, it is possible to prevent the high-order diffracted lights L21 and L22 from the diffractive optical element 40 from being reflected or refracted by the projection optical system 50. As a result, the high-order diffracted lights L21 and L22 enter the eyes of the observer and cause safety problems, or the high-order diffracted lights L21 and L22 are projected onto the projection surface S to illuminate areas other than the illuminated areas Z1 and Z2. Thus, it is prevented that it becomes difficult to recognize the illuminated areas Z1 and Z2. Further, since the first lens 71 is disposed away from the diffractive optical element 40 by the above-mentioned distance, the 0th-order light L01, L02, the first-order diffracted light L11, L12, and the higher-order diffracted light L21, The path of L22 is adjusted, and it is easy to arrange the high-order diffracted light mask 82 so as to block only the high-order diffracted lights L21 and L22. Further, since the second lens 72 is disposed away from the first lens 71 by the above-described distance, the characteristics of the first diffracted light L11 and the second diffracted light L12 that have passed through the first lens 71 and the second lens 72 are displayed. In accordance with the characteristics of the first diffracted light L11 and the second diffracted light L12 in the diffractive optical element 40. As a result, it is possible to illuminate the illuminated areas Z1 and Z2 with a desired pattern according to the diffraction characteristics of the diffractive optical element 40 (for example, the interference fringe pattern recorded on the element diffractive optical elements 41 and 42).

  In the above, a plurality of embodiments and modifications thereof have been described. Naturally, it is possible to appropriately combine a plurality of configurations described as different embodiments and different modifications.

Z1 first illuminated area Z2 second illuminated area 10 illumination device 15 light source 32 collimating lens 40 diffractive optical element 41 first element diffractive optical element 42 second element diffractive optical element 50 projection optical system 51 first reflecting surface 52 second Reflective surface 71 First lens 72 Second lens 81 0th-order light mask 82 High-order diffracted light mask

Claims (1)

A light source that emits light;
A diffractive optical element that diffracts the light emitted from the light source;
A projection optical system that reflects or refracts the light diffracted by the diffractive optical element and directs it toward the projection surface, and
The projection optical system is an illumination device that directs a part of the first-order diffracted light diffracted by the diffractive optical element and another part in different directions.