JP2018163851A - Lighting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lighting device which can reduce burden on applying to a scanning device which has a failure risk obviously by vibration, noise, heat generation and the like occurred during operation, with a factor hologram to which light is fixedly directed continuously as an object to be scanned.SOLUTION: A lighting device 10 includes: a light source 15 for emitting light; a division element 20 for dividing the light emitted from the light source into a first light source light SL1 and a second light source light SL2; a fixed diffractive optical element 45 for diffracting the first light source light SL1; a variable diffractive optical element 50 for diffracting the second light source light SL2; and a scanning device 30 for changing an incident position on the variable diffractive optical element 50 by changing a light path of the second light source light SL2. The variable diffractive optical element 50 includes a plurality of factor diffractive optical elements.SELECTED DRAWING: Figure 1

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 diffractive optical element is known. The illumination device disclosed in Patent Literature 1 includes a light source, a scanning device, and a diffractive optical element. The scanning device changes the traveling direction of light emitted from the light source over time. Thereby, the light emitted from the light source is incident on the diffractive optical element so as to scan the diffractive optical element. The diffractive optical element includes a plurality of element holograms having different diffraction characteristics. The light source switches between light emission and light emission stop according to the operation of the scanning device, that is, according to the incident position on the diffractive optical element. According to this illuminating device, the region irradiated with the illumination light can be switched to a desired pattern.

Japanese Patent Laid-Open No. 2016-110813

  By the way, in many cases where illumination is performed using an illumination device, there is always a region where illumination is desired. For example, in a car headlamp, while always illuminating the front area, if necessary, in addition to the front area, the left and right areas located on the left and right of the front area and the far area ahead of the front area can be illuminated. desired. In the conventional illumination device, the light source emits light at the timing when the light scans on the element hologram that always diffracts the light to the area to be illuminated. However, even element holograms to which light is continuously directed are set as scanning targets, which means that vibration, noise, heat generation, etc. associated with the operation of the scanning device become more conspicuous, and there is a risk of failure of the scanning device.

  The present disclosure has been made in consideration of the above points, and an object thereof is to reduce a burden associated with application of a scanning device to an illumination device.

A first lighting device according to the present invention comprises:
A light source that emits light;
A splitting element that splits light emitted from the light source into first light source light and second light source light;
A fixed diffractive optical element that diffracts the first light source light;
A variable diffractive optical element that diffracts the second light source light;
A scanning device that changes an incident position on the variable diffractive optical element by changing an optical path of the second light source light,
The variable diffractive optical element includes a plurality of element diffractive optical elements.

  In the first illumination device according to the present invention, the light source may stop emitting light in accordance with the operation of the scanning device.

  In the first illumination device according to the present invention, the variable diffractive optical element may include a dummy portion that regulates the progress of the second light source light to the illuminated area.

A second lighting device according to the present invention comprises:
A light source that emits light;
A variable mask positioned outside the optical path of the first light source light of the light source light emitted from the light source and on the optical path of the second light source light of the light source light;
A fixed diffractive optical element that diffracts the first light source light;
A variable diffractive optical element that diffracts the second light source light,
The variable mask can change an incident area of the second light source light on the variable diffractive optical element,
The variable diffractive optical element includes a plurality of element diffractive optical elements.

A third lighting device according to the present invention comprises:
A light source that emits light;
A diffractive optical element that diffracts light emitted from the light source;
A variable shaping optical system positioned between the light source and the diffractive optical element along an optical path of light emitted from the light source,
The variable shaping optical system variably shapes light emitted from the light source, and adjusts the size of an incident region on the diffractive optical element,
The diffractive optical element includes a fixed diffractive optical element on which light emitted from the light source is incident regardless of a size of an incident area on the diffractive optical element, and an incident area on the diffractive optical element is enlarged. And a variable diffractive optical element on which light emitted from the light source enters.

  In the third illumination device according to the present invention, the variable diffractive optical element may include a plurality of element diffractive optical elements.

In a third lighting device according to the present invention,
The variable shaping optical system includes a lens,
The lens may be supported so as to be movable in a direction parallel to the optical axis of the lens.

In the third illumination device according to the present invention, the variable shaping optical system includes a beam expander for diverging light emitted from the light source,
In the third illumination device according to the present invention, the beam expander may be movably supported.

  In the third illumination device according to the present invention, the variable shaping optical system may include a variable stop.

  According to the present disclosure, it is possible to reduce a burden associated with application of the scanning device to the illumination device.

FIG. 1 is a diagram for explaining a first embodiment of the present disclosure, and is a schematic diagram illustrating a lighting device. FIG. 2 is a plan view showing a diffractive optical element of the illumination apparatus of FIG. FIG. 3 is a diagram illustrating an example of an illuminated area illuminated by the illumination device of FIG. FIG. 4 is a diagram illustrating an example of an irradiation pattern of the element diffractive optical element included in the variable diffractive optical element. FIG. 5 is a diagram illustrating an example of an illumination pattern of an illuminated area when the variable diffractive optical element is irradiated with light source light with the illumination pattern of FIG. FIG. 6 is a diagram showing another example of the irradiation pattern of the element diffractive optical element included in the variable diffractive optical element. FIG. 7 is a diagram illustrating an example of an illumination pattern of an illuminated area when the variable diffractive optical element is irradiated with light source light with the illumination pattern of FIG. FIG. 8 is a diagram illustrating another example of an illuminated area illuminated by the illumination device of FIG. FIG. 9 is a diagram for describing the second embodiment of the present disclosure, and is a schematic diagram illustrating a lighting device. FIG. 10 is a plan view showing a diffractive optical element of the illumination device of FIG. FIG. 11 is a diagram for explaining the third embodiment of the present disclosure, and is a schematic diagram illustrating a lighting device. 12 is a plan view showing a diffractive optical element of the illumination device of FIG. FIG. 13 is a diagram illustrating an example of an illuminated area illuminated by the illumination device of FIG. FIG. 14 is a diagram corresponding to FIG. 11 and is a schematic diagram illustrating a modification of the illumination device. FIG. 15 is a diagram corresponding to FIG. 11 and is a schematic diagram illustrating another modification of the illumination device. FIG. 16 is a diagram corresponding to FIG. 1 and is a schematic diagram showing a modification of the illumination device. FIG. 17 is a diagram corresponding to FIG. 9 and is a schematic diagram illustrating a modification of the illumination device. FIG. 18 is a diagram corresponding to FIG. 11 and is a schematic diagram illustrating a modification of the lighting device.

  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.

  The illuminating device 10 described below illuminates the illuminated area Z by diffusing light emitted from the light source, hereinafter referred to as light source light, by the diffractive optical element 40 toward the illuminated area Z. . In particular, the illuminated area Z of the illumination device 10 described below includes a fixed illuminated area Zf and a variable illuminated area Zv. The fixed illumination area Zf is an area that is always illuminated by illumination light emitted from the illumination device 10 during operation of the illumination device 10. On the other hand, the variable illumination area Zv is an area irradiated with illumination light in addition to the fixed illumination area Zf as necessary. Further, in some examples, it is possible to change the illumination pattern of the variable illuminated area Zv. Here, the illuminated area Z can be represented as an actual illuminated area (illumination range) illuminated by the diffractive optical element 40, and can also be represented by an angular range in an angular space after setting a certain coordinate axis. be able to.

  Such a lighting device 10 can be used in various fields, for example, as a lighting device for a moving body such as a car or a ship. And in a plurality of embodiments described below, a device for dealing with a conventional defect, specifically, vibration, noise, heat generation, etc. associated with the operation of the scanning device are effectively suppressed, and A device for reducing the risk of failure of the scanning device has been devised.

<First Embodiment>
First, a first embodiment will be described with reference to FIGS.

  FIG. 1 is a schematic diagram illustrating an example of a lighting device 10 according to the first embodiment. As shown in FIG. 1, in the first embodiment, the illumination device 10 includes a light source 15 that emits light and a diffractive optical element 40 that diffracts the light emitted from the light source 15, that is, the light source light SL. It is out. The illumination device 10 shown in FIG. 1 includes a splitting element 20 that splits the light source light SL into a first light source light SL1 and a second light source light SL2, a shaping optical system 25 that shapes the first light source light SL1, And a scanning device 30 for adjusting the optical path of the two light source light SL2. The diffractive optical element 40 includes a fixed diffractive optical element 45 that diffracts the first light source light SL1 and a variable diffractive optical element 50 that diffracts the second light source light SL2. The diffracted light diffracted by the fixed diffractive optical element 45 is directed to the fixed illuminated area Zf, and the diffracted light diffracted by the variable diffractive optical element 50 is directed to the variable illuminated area Zv. Hereinafter, each component will be described 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. Laser light projected from the laser light source has excellent straightness and is suitable as light for illuminating the illuminated area Z with high accuracy.

  The illustrated light source 15 includes a single laser light source. Therefore, in the illustrated example, the illuminated area Z is illuminated with a color corresponding to the wavelength range of the laser light oscillated from the laser light source. However, the light source 15 includes a plurality of laser light sources so that the illuminated area Z can be illuminated with a desired color, and after the light emitted from each laser light source is superimposed, the dividing element 20, the shaping optical system 25, The light may be directed toward the scanning device 30 and the diffractive optical element 40, or the light emitted from each laser light source may be directed to the dividing element 20, the shaping optical system 25, the scanning device 30, and the diffractive optical device provided corresponding to the laser light source. It may be superimposed on the illuminated area Z after passing through the element 40. In such an example, the plurality of laser light sources included in the light source 15 may not only emit light in different wavelength ranges but also emit light in the same wavelength range. Since the light source 15 includes a laser light source that emits light in the same wavelength region, the illuminated region Z can be illuminated brightly.

  The splitting element 20 splits the light source light SL emitted from the light source 15 into a first light source light SL1 and a second light source light SL2. A half mirror can be used as such a dividing element 20. In the illuminating device 10 shown in FIG. 1, the light source light SL reflected by the split element 20 made of a half mirror becomes the first light source light SL1, and the light source light SL transmitted through the split element 20 made of the half mirror is the second light source light SL. It becomes the light source light SL2. The first light source light SL1 is diffracted by the fixed diffractive optical element 45 to illuminate the fixed illuminated area Zf. The second light source light SL2 is diffracted by the variable diffractive optical element 50 to illuminate the variable illuminated area Zv. By adjusting the reflectance of the splitting element 20 formed of a half mirror, the illumination light quantity of the fixed illumination area Zf and the variable illumination area Zv can be adjusted. Further, as the splitting element 20, a combination of a dichroic mirror, a band pass filter, a wave plate, and a polarization beam splitter can be used.

  Next, the shaping optical system 25 will be described. The first light source light SL1 separated from the second light source light SL2 by the splitting element 20 travels to the shaping optical system 25. The shaping optical system 25 shapes the first light source light SL1. In other words, the shaping optical system 25 shapes the shape of the cross section perpendicular to the optical axis of the first light source light SL1 and the three-dimensional shape of the light beam of the first light source light SL1. In the illustrated example, the shaping optical system 25 shapes the first light source light SL1 into a widened parallel light beam. As shown in FIG. 1, the shaping optical system 25 includes a beam expander 26 and a lens 27 in the order along the optical path of the first light source light SL1. The beam expander 26 shapes the laser light emitted from the light source 15 into a divergent light beam. The lens 27 reshapes the divergent light beam generated by the beam expander 26 into a parallel light beam. The shaping optical system 25 may use a normal lens so that the incident area of the first light source light SL1 on the fixed diffractive optical element 45 is circular, or the incident area is rectangular. As described above, a cylindrical lens may be used, and a mask may be used so that the incident region has a desired shape such as a rectangular shape.

  Next, the scanning device 30 will be described. The scanning device 30 changes the traveling direction of the second light source light SL2 with time so that the traveling direction of the second light source light SL2 does not become constant. As a result, the second light source light SL2 emitted from the scanning device 30 scans the incident surface of the variable diffractive optical element 50 of the diffractive optical element 40.

  The scanning device 30 includes a reflecting mirror 31 that is rotatable around two rotation axes that are parallel to the directions intersecting each other. The second light source light SL2 incident on the reflecting mirror 31 is reflected at an angle corresponding to the tilt angle of the reflecting mirror 31 and travels toward the fixed diffractive optical element 45. The second light source light SL2 can be scanned two-dimensionally on the incident surface of the variable diffractive optical element 50 by rotating the reflecting mirror 31 around two rotation axes. For example, the reflecting mirror 31 repeats a certain operation of rotating around two rotation axes at a certain cycle. The incident position of the second light source light SL2 on the diffractive optical element 40 changes with periodicity and repeatedly moves, for example, along the scanning path sp shown in FIG. As such a scanning device 30, for example, a MEMS mirror can be used.

  Next, the diffractive optical element 40 will be described. The diffractive optical element 40 is an element that exerts a diffraction action on the light source light SL emitted from the light source 15. The diffractive optical element 40 diffracts the light source light SL and directs it toward the illuminated area Z. Therefore, the illuminated area Z is illuminated by the diffracted light from the diffractive optical element 40.

  The illustrated diffractive optical element 40 includes a fixed diffractive optical element 45 and a variable diffractive optical element 50. The fixed diffractive optical element 45 diffracts the first light source light SL1 of the light source light SL and directs it toward the fixed illuminated area Zf. On the other hand, the variable diffractive optical element 50 diffracts the second light source light SL2 in the light source light SL and directs it to the variable illuminated area Zv. The variable diffractive optical element 50 includes a plurality of element diffractive optical elements 51. Each element diffractive optical element 51 diffracts the second light source light SL2, and directs the diffracted light to different element illuminated areas Zve in the illustrated example.

  FIG. 2 is a plan view showing the diffractive optical element 40. In the illustrated diffractive optical element 40, the fixed diffractive optical element 45 and the variable diffractive optical element 50 are disposed adjacent to each other. That is, the fixed diffractive optical element 45 and the variable diffractive optical element 50 are arranged so that one optical element is divided into planes. The variable diffractive optical element 50 includes first to fifth element diffractive optical elements 51a to 51e. The first to fifth element diffractive optical elements 51a to 51e are arranged adjacent to each other on a straight line.

  FIG. 3 shows an example of the illuminated area Z illuminated by the diffractive optical element 40. In the example shown in FIG. 3, the fixed illumination area Zf illuminated by the diffracted light from the fixed diffractive optical element 45 is a wide area extending in front of the illumination device 10. The variable illuminated area Zv illuminated by the diffracted light from the variable diffractive optical element 50 includes an area located on both sides of the fixed illuminated area Zf and an area further ahead of the fixed illuminated area Zf. The variable illuminated area Zv is divided into five corresponding to each element diffractive optical element 51, and includes first to fifth element illuminated areas Zve1 to Zve5. The first element illuminated area Zve1 illuminated by the diffracted light from the first element diffractive optical element 51a is located on the left side of the fixed illuminated area Zf. The second element illuminated area Zve2 illuminated by the diffracted light from the second element diffractive optical element 51b is located to the left of the front area of the fixed illuminated area Zf. The third element illuminated area Zve3 illuminated by the diffracted light from the third element diffractive optical element 51c is located in the center of the front area of the fixed illuminated area Zf. The fourth element illuminated area Zve4 illuminated by the diffracted light from the fourth element diffractive optical element 51d is located to the right of the front area of the fixed illuminated area Zf. The fifth element illuminated area Zve5 illuminated by the diffracted light from the fifth element diffractive optical element 51e is located on the right side of the fixed illuminated area Zf.

  That is, in the example shown in FIG. 3, the fixed diffractive optical element 45 and the variable diffractive optical element 50 have different diffraction characteristics and illuminate at least partially different regions. The plurality of element illuminated areas Zve included in the variable diffractive optical element 50 have different diffraction characteristics and illuminate at least partially different areas.

  However, the illuminated area Z shown in FIG. 3 is merely an example. In the example shown in FIG. 3, an example in which the fixed illumination area Zf and the variable illumination area Zv do not overlap each other is shown, but at least a portion may overlap, and either one is included in the other. You may make it do, and also it may be the same. Further, the fixed illumination area Zf and the variable illumination area Zv do not need to be in contact with each other and may be separated from each other. Similarly, the plurality of element illuminated areas Zve do not overlap in the illustrated example, but may overlap at least in part, or any one of them may be included in another one. Further, any one of them may be the same as the other one. Further, the plurality of element illuminated areas Zve do not have to be in contact with each other, and may be separated from each other.

  The illuminated area Z shown in FIG. 3 is represented as a near-field illuminated area that is illuminated by being overlapped by the diffractive optical element 40. Then, after the light whose path has been adjusted by the diffractive optical element 40 passes through the illuminated area Z, it illuminates a predetermined range on the ground, which is an actual illumination range. The far field illumination range is often expressed as a diffuse angle distribution in the angle space rather than the actual size of the illuminated area. In this specification, the terms “illuminated area”, “fixed illuminated area”, “variable illuminated area”, and “element illuminated area” include not only the actual illuminated area (illumination range) but also the diffusion angle range in the angular space. It shall be.

  As an example, the fixed diffractive optical element 45, the variable diffractive optical element 50, and the element diffractive optical element 51 constituting the diffractive optical element 40 can be 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 40, 45, 50, 51, in other words, the traveling direction of the light diffused by each element 40, 45, 50, 51 can be changed. Can be controlled.

  Each element 40, 45, 50, 51 can be fabricated using, for example, scattered light from a real scattering plate as object light. More specifically, when the hologram photosensitive material that is the base of the elements 40, 45, 50, and 51 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 formed on the hologram photosensitive material, and the elements 40, 45, 50, and 51 are manufactured. 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.

  The elements 40, 45, 50, 51 are irradiated with laser light toward the elements 40, 45, 50, 51 so as to travel in the reverse direction of the optical path of the reference light used when the elements 40, 45, 50, 51 are manufactured. , 51, a reproduction image of the scattering plate is generated at the arrangement position of the scattering plate which is the source of the object light used in manufacturing. If the scattering plate that is the source of the object light used in manufacturing the elements 40, 45, 50, and 51 has a uniform surface scattering, a reproduced image of the scattering plate obtained by the elements 40, 45, 50, and 51 is obtained. Also, the surface illumination is uniform, and the region where the reproduced image of the scattering plate is generated can be the regions Z, Zf, Zv, Zve to be illuminated.

  Further, the complex interference fringe pattern formed on each element 40, 45, 50, 51 is not formed using actual object light and reference light, but the wavelength and incident direction of the planned reproduction illumination light, and It is possible to design using a computer based on the shape and position of the image to be reproduced. The elements 40, 45, 50, 51 thus obtained are also called computer generated holograms (CGH). For example, when the illuminating device 10 is used to illuminate an illuminated area Z having a certain size on the ground surface or water surface, it is difficult to generate object light, and a computer-generated hologram is used as the element 40, It is suitable to use as 45, 50, 51.

  Further, a Fourier transform hologram having the same diffusion angle characteristic at each point on each element 40, 45, 50, 51 may be formed by computer synthesis. Furthermore, an optical member such as a lens may be provided on the downstream side of the elements 40, 45, 50, 51, and adjustment may be performed so as to be incident on the entire area Z, Zf, Zv, Zve to be illuminated.

  As a specific form of the elements 40, 45, 50, 51, a volume hologram recording medium using a photopolymer may be used, or a volume hologram recording medium of a type for recording using a photosensitive medium containing a silver salt material. Alternatively, a relief (embossed) hologram recording medium may be used. The elements 40, 45, 50, 51 may be transmissive or reflective.

  Returning to FIG. 2, the variable diffractive optical element 50 includes a dummy portion 52 in addition to the five element diffractive optical elements 51. The dummy part 52 is an optical member that prevents the second light source light SL2 from proceeding to the illuminated area Z. As the dummy part 52, typically, a member having light absorption can be used. As another example, the dummy part 52 can use a member that guides light to a collection region other than the illuminated region Z, such as a reflective surface or a diffractive optical element.

  As will be described later, the dummy portion 52 is provided for the purpose of keeping the brightness of the fixed illumination area Zf constant regardless of the illumination pattern in the variable illumination area Zv. As described above, the optical path of the second light source light SL2 incident on the variable diffractive optical element 50 changes with time by the scanning device 30. FIG. 2 shows the scanning path sp of the incident position of the second light source light SL2 incident on the variable diffractive optical element 50. The dummy part 52 is preferably provided so that the total length of the scanning path sp on the dummy part 52 and the total length of the scanning path sp on the element diffractive optical element 51 are the same. In the example shown in FIG. 2, the five element diffractive optical elements 51 have the same planar view shape. The dummy part 52 includes five element dummy parts having the same planar view shape as the element diffractive optical element 51, the same as the number of element diffractive optical elements 51. In the example shown in FIG. 2, the first to fifth element diffractive optical elements 51 a to 51 e are arranged in the upper region of the variable diffractive optical element 50, and the first to fifth regions are disposed in the lower region. The fifth element dummy portions 52a to 52e are arranged. However, the example is not limited to the example illustrated in FIG. 2. For example, the dummy units 52 and the element diffractive optical elements 51 may be alternately arranged along the scanning path sp.

  Incidentally, as illustrated in FIG. 1, the illumination device 10 further includes a control unit 11. The control unit 11 is electrically connected to the light source 15 and the scanning device 30. The control unit 11 controls operations of the light source 15 and the scanning device 30. The control unit 11 controls the emission of the light source light SL from the light source 15 in synchronization with the operation of the scanning device 30. The control of whether or not the light source light SL is emitted by the control unit 11 is performed based on the scanning timing of the scanning device 30, in other words, based on the incident position of the second light source light SL2 on the variable diffractive optical element 50. . That is, the control unit 11 determines whether or not the second diffractive optical element 51 is irradiated with each element diffractive optical element 51 according to a desired illumination pattern in the variable illuminated area Zv, and whether or not the light source light SL is emitted from the light source 15. Control by switching injection stop.

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

  The light source light SL emitted from the light source 15 first enters the splitting element 20. The light source light SL is split by the splitting element 20 into a first light source light SL1 and a second light source light SL2.

  The first light source light SL1 enters the shaping optical system 25. The shaping optical system 25 increases the optical path width of the first light source light SL1. That is, the shaping optical system 25 shapes the first light source light SL1 so that a region occupied by light spreads in a cross section orthogonal to the optical axis. The shaping optical system 25 includes a beam expander 26 and a lens 27. As shown in FIG. 1, the beam expander 26 of the shaping optical system 25 divides the light emitted from the light source 15 and converts it into a divergent light beam. The lens 27 of the shaping optical system 25 collimates the divergent light beam into a parallel light beam. The first light source light SL1 shaped by the shaping optical system 25 then enters the fixed diffractive optical element 45 of the diffractive optical element 40. The fixed diffractive optical element 45 diffracts the first light source light SL1 and directs it toward the fixed illuminated region Zf. Thereby, the fixed illumination area Zf is illuminated by the diffracted light diffracted by the fixed diffractive optical element 45.

  The second light source light SL2 enters the scanning device 30. The scanning device 30 changes the optical path of the second light source light SL2 over time. The change in the optical path of the second light source light SL2 is periodic. The second light source light SL2 then enters the variable diffractive optical element 50 of the diffractive optical element 40. The incident position of the second light source light SL2 on the variable diffractive optical element 50 moves along the scanning path sp. That is, the second light source light SL2 is incident on the variable diffractive optical element 50 so as to scan the variable diffractive optical element 50. The variable diffractive optical element 50 includes a plurality of element diffractive optical elements 51 and a plurality of dummy parts 52. As shown in FIG. 2, the scanning path sp of the second light source light SL <b> 2 extends over the plurality of element diffractive optical elements 51 and the plurality of dummy portions 52. At this time, the control unit 11 switches the presence or absence of emission of the light source light SL from the light source 15 according to a desired illumination pattern in the variable illuminated area Zv.

  In the example shown in FIG. 4, the second light source light SL2 is incident on the second element diffractive optical element 51b, the third element diffractive optical element 51c, and the fourth element diffractive optical element 51d, and the first element diffractive optical element 51a. In addition, the second light source light SL2 is not incident on the fifth element diffractive optical element 51e. At this time, as shown in FIG. 5, the fixed illuminated area Zf is illuminated by the first light source light SL1, and the second element illuminated area Zve2, the third element illuminated area Zve3 in the variable illuminated area Zv, and The fourth element illuminated area Zve4 is illuminated by the second light source light SL2.

  In the example shown in FIG. 6, the second light source light SL2 is incident on the first element diffractive optical element 51a, and the second light source light SL2 is incident on the second to fifth element diffractive optical elements 51b to 51e. Not. At this time, as shown in FIG. 7, the fixed illuminated area Zf is illuminated by the first light source light SL1, and only the first element illuminated area Zve1 is illuminated by the second light source light SL2 in the variable illuminated area Zv. Is done.

  As described above, the illumination apparatus 10 illuminates the variable diffractive optical element 50 with a desired pattern while continuing to illuminate the fixed diffractive optical element 45, or does not illuminate the variable diffractive optical element 50. The first light source light SL1 diffracted by the fixed diffractive optical element 45 and used for illumination of the fixed illuminated area Zf does not enter the scanning device 30. That is, the fixed diffractive optical element 45 is not included in the scanning path sp of the light source light SL on the diffractive optical element 40 by the scanning device 30. Thus, by omitting the fixed diffractive optical element 45 that diffracts light toward the fixed illuminated area Zf that is constantly illuminated from the scanning path sp of the light source light SL on the diffractive optical element 40, the scanning path sp is reduced. Can be shortened. Thereby, vibration, noise, heat generation and the like accompanying the operation of the scanning device 30 can be effectively suppressed, and the failure risk of the scanning device 30 can be effectively reduced.

  Incidentally, the incidence of the second light source light SL2 into each element diffractive optical element 51 is controlled according to a desired illumination pattern in the variable illuminated area Zv. In the illustrated example, the incidence of the second light source light SL2 into each element diffractive optical element 51 is controlled by switching the emission of the light source light SL from the light source 15 and the emission stop. However, when the emission of the light source light SL from the light source 15 stops, the first light source light SL1 does not enter the fixed diffractive optical element 45 at a timing when the second light source light SL2 does not enter the variable diffractive optical element 50. The operation of the scanning device 30 is extremely fast, and the presence or absence of illumination light incident on each region cannot be determined by human eyes. However, if the ratio of the period during which the light source 15 emits the light source light SL with respect to the period corresponding to one cycle of the scanning device 30 varies, the variation in brightness may be visually recognized by human eyes in the fixed illumination area Zf. There is. Further, when none of the element illuminated areas Zve in the variable illuminated area Zv is illuminated, the light source light SL is not emitted from the light source 15 and the fixed diffractive optical element 45 cannot be illuminated. In order to deal with such a problem, the variable diffractive optical element 50 includes a dummy portion 52 that does not contribute to illumination of the illuminated region Z in addition to the element diffractive optical element 51.

  In the example shown in FIG. 4 for realizing the illumination pattern of FIG. 5, the second light source light SL2 is incident on the first element dummy part 52a and the fifth element dummy part 52e, and the second element dummy part 52b, The second light source light SL2 is not incident on the three-element dummy part 52c and the fourth element dummy part 52d. As a result, the light source 15 emits the light source light SL while scanning five regions that are half of the ten regions obtained by dividing the variable diffractive optical element 50 into a plane, and half of the ten regions. During the scanning of the remaining five regions, the emission of the light source light SL is stopped. That is, while the incident position of the second light source light SL2 goes around the scanning path sp, that is, during the operation for one cycle of the scanning device 30, the light source 15 emits the light source light SL over a half period, The emission of the light source light SL is stopped for the remaining half period.

  Further, in the example shown in FIG. 6 for realizing the illumination pattern of FIG. 7, the second light source light SL2 enters the first element dummy portion 52a to the fourth element dummy portion 52d, and the fifth element dummy portion 52e. Is not incident on the second light source light SL2. In the example of FIG. 7 as well, the light source 15 emits the light source light SL while scanning five regions that are half of the ten regions obtained by dividing the variable diffractive optical element 50 into planes, and The emission of the light source light SL is stopped while the remaining five regions, which are half of them, are scanned. That is, while the incident position of the second light source light SL2 goes around the scanning path sp, that is, during the operation for one cycle of the scanning device 30, the light source 15 emits the light source light SL over a half period, The emission of the light source light SL is stopped for the remaining half period.

  That is, in the illustrated example, the variable diffractive optical element 50 is provided with the dummy portion 52 that does not contribute to the illumination of the variable diffractive optical element 50, thereby causing the emission of the light source light SL from the light source 15 to stop. The brightness fluctuation in the fixed illuminated area Zf during illumination can be effectively suppressed. In particular, in the illustrated example, the variable diffractive optical element 50 includes the same number of dummy portions 52 as the element diffractive optical elements 51, and therefore, more accurately expressed, the scanning paths sp on the plurality of dummy portions 52 Since the total length is the same as the total length of the scanning paths sp on the plurality of element diffractive optical elements 51, the brightness in the fixed illuminated area Zf during illumination can be made uniform.

  In the first embodiment described above, the lighting device 10 divides the light source 15 that emits light and the light source light SL emitted from the light source 15 into the first light source light SL1 and the second light source light SL2. The splitting element 20, the fixed diffractive optical element 45 that diffracts the first light source light SL1, the variable diffractive optical element 50 that diffracts the second light source light SL2, and the variable diffractive optical element 50 by changing the optical path of the second light source light SL2. And a scanning device 30 that changes the incident position of the second light source light SL2. The variable diffractive optical element 50 includes a plurality of element diffractive optical elements 51. In such a first embodiment, the emission of the light source light SL from the light source 15 and the emission stop of the light source light SL according to the operation of the scanning device 30, that is, according to the scanning positions on the plurality of dummy units 52. , While illuminating the fixed illumination area Zf using the diffracted light from the fixed diffractive optical element 45, and simultaneously, using the diffracted light from the variable diffractive optical element 50, the desired element illuminated area Zve is obtained. Can be illuminated. The fixed diffractive optical element 45 is not included in the scanning path sp of the light source light SL by the scanning device 30. Therefore, the scanning path sp by the scanning device 30 can be shortened, vibration, noise, heat generation and the like accompanying the operation of the scanning device 30 can be effectively suppressed, and the failure risk of the scanning device 30 is effectively reduced. Can be reduced.

  In the first embodiment, the variable diffractive optical element 50 includes a dummy portion 52 that prevents the second light source light SL2 from proceeding to the illuminated region Z. In such an illuminating device 10, the irradiation period of the second light source light SL2 to the dummy part 52 can be adjusted according to the number of element diffractive optical elements 51 irradiated with the second light source light SL2. Thus, the period during which the light source 15 emits light can be adjusted while the scanning device 30 performs one periodic operation along the scanning path sp. As a result, it is possible to illuminate the fixed illumination area Zf with a constant brightness regardless of the illumination pattern of the variable illumination area Zv.

  Various changes can be made to the first embodiment described above. Hereinafter, an example of modification will be described with reference to the drawings. In the following description and the drawings used in the following description, parts that can be configured in the same manner as in the first embodiment described above are the same as those used for the corresponding parts in the first embodiment described above. Reference numerals will be used, and redundant description will be omitted.

  In 1st Embodiment mentioned above, although the illuminating device 10 showed the example which illuminates the predetermined to-be-illuminated area Z brightly, it is not restricted to this. For example, as shown in FIG. 8, the illuminating device 10 may illuminate a region having a predetermined contour, and thus function as a device that displays the predetermined contour. In the example shown in FIG. 8, the first element illuminated area Zve1 is an area having an outer outline of an arrow pointing to the left, and the fifth element illuminated area Zve5 has an outer outline of an arrow pointing to the right. It has become an area.

  In the first embodiment described above, the light source 15 switches the emission of the light source light SL and the emission stop of the light source light SL, thereby controlling the incidence of the second light source light SL2 on each element diffractive optical element 51. The variable illuminated area Zv is illuminated with a desired illumination pattern, but the present invention is not limited to this example. For example, as indicated by a two-dot chain line in FIG. 1, a shutter 35 may be provided between the dividing element 20 and the scanning device 30 along the optical path of the second light source light SL2. The shutter 35 may be operated by a control signal from the control unit 11 so as to block the second light source light SL2 directed to the scanning device 30 in accordance with the operation of the scanning device 30. According to this example, the dummy portion 52 of the variable diffractive optical element 50 can be eliminated, the scanning path sp by the scanning device 30 can be further shortened, and the burden on the scanning device 30 can be reduced.

  Further, in the first embodiment described above, the example in which the light source light SL emitted from the light source 15 is directly incident on the splitting element 20 has been described, but the present invention is not limited to this example. As shown in FIG. 16, the light source light SL emitted from the light source 15 may be conveyed by the optical fiber 16. In the example shown in FIG. 16, the light source light SL emitted from the end portion 16 a of the optical fiber 16 is shaped by the shaping element 17 and then enters the dividing element 20. For example, a collimator lens can be used as the shaping element 17. As shown in FIG. 16, the light source light SL emitted from the end portion 16a of the optical fiber 16 forms a divergent light beam. The shaping element 17 formed of a collimator lens converts the divergent light beam into a parallel light beam. In the example shown in FIG. 16, the splitting element 20 splits an incident parallel light beam into a first light source light SL1 as a parallel light beam and a second light source light SL2 as a parallel light beam.

<Second Embodiment>
Next, a second embodiment will be described with reference to FIGS. 9 and 10. In the following description and the drawings used in the following description, parts that can be configured in the same manner as in the first embodiment described above are the same as those used for the corresponding parts in the first embodiment described above. Reference numerals will be used, and redundant description will be omitted.

  FIG. 9 is a schematic diagram illustrating an example of the illumination device 10 according to the second embodiment. As shown in FIG. 9, in the second embodiment, the illumination device 10 includes a light source 15 that emits light and a diffractive optical element 40 that diffracts the light emitted from the light source 15, that is, the light source light SL. It is out. 9 further includes a shaping optical system 25 and a variable mask 60 in this order between the light source 15 and the diffractive optical element 40 along the optical path of the light source light SL. Hereinafter, each component of the illumination device 10 will be described.

  The light source 15 can be configured similarly to the first embodiment. The shaping optical system 25 is provided on the optical path of the first light source light SL1 in that the shaping optical system 25 is provided on the optical path of the light source light SL, and shapes the first light source light SL1. Although different from the shaping optical system, the light shaping means may be configured in the same manner as in the first embodiment. In the example shown in FIG. 9, the shaping optical system 25 includes a beam expander 26 and a lens 27.

  The variable mask 60 is provided on the optical path of a part of the light source light SL emitted from the light source. In the example illustrated in FIG. 9, the variable mask 60 is disposed so as to block a part of the optical path of the light source light SL widened by the shaping optical system 25. The diffractive optical element 40 includes a fixed diffractive optical element 45 and a variable diffractive optical element 50. Light of the light source light SL that is not blocked by the variable mask 60 enters the fixed diffractive optical element 45 of the diffractive optical element 40 as the first light source light SL1. On the other hand, the light incident on the variable mask 60 in the light source light SL changes the pattern and enters the variable diffractive optical element 50 of the diffractive optical element 40 as the second light source light SL2.

  FIG. 10 shows an example of a diffractive optical element 40 that can be applied to the illumination device 10 of FIG. 9 as a plan view. The diffractive optical element 40 has a wide fixed diffractive optical element 45 in a lower region. The diffractive optical element 40 includes a variable diffractive optical element 50 in a region above the fixed diffractive optical element 45. The variable diffractive optical element 50 has a plurality of element diffractive optical elements 51 by being divided into planes in the width direction. In the example shown in FIG. 10, the variable diffractive optical element 50 includes five element diffractive optical elements 51. The first to fifth element diffractive optical elements 51a to 51e included in the variable diffractive optical element 50 have different diffraction characteristics. The diffracted light diffracted by the regions 45, 50, 51 of the diffractive optical element 40 is directed to the illuminated region Z and illuminates the illuminated region Z.

  As an example, the first light source light SL1 diffracted by the fixed diffractive optical element 45 illuminates the fixed illuminated region Zf of FIG. 3, and the second light source light SL2 diffracted by the variable diffractive optical element 50 is shown in FIG. The variable illuminated area Zv may be illuminated. Further, the second light source light SL2 diffracted by the first element diffractive optical element 51a illuminates the first element illuminated region Zve1 of FIG. 3, and the second light source light SL2 diffracted by the second element diffractive optical element 51b. Illuminates the second element illuminated area Zve2 of FIG. 3, and the second light source light SL2 diffracted by the third element diffractive optical element 51c illuminates the third element illuminated area Zve3 of FIG. The second light source light SL2 diffracted by the element diffractive optical element 51d illuminates the fourth element illuminated region Zve4 of FIG. 3, and the second light source light SL2 diffracted by the fifth element diffractive optical element 51e is shown in FIG. The fifth element illuminated area Zve5 may be illuminated.

  Note that, in the second embodiment as well as in the first embodiment, the fixed illumination area Zf and the variable illumination area Zv may not overlap, or may overlap at least partially. Either one may be included in the other, or may be the same. Further, the fixed illumination area Zf and the variable illumination area Zv do not need to be in contact with each other and may be separated from each other. Similarly, the plurality of element illuminated regions Zve may not overlap, may overlap at least in part, or may be included in one of the other. Further, any one of them may be the same as the other one. Further, the plurality of element illuminated areas Zve do not have to be in contact with each other, and may be separated from each other.

  The variable mask 60 controls the incident area ia of the second light source light SL2 on the variable diffractive optical element 50 (see FIG. 9). As the variable mask 60, various devices that can adjust the incident area ia of the second light source light SL2 on the variable diffractive optical element 50 can be adopted. Typically, a spatial light modulator 61 can be used as the variable mask 60. As the spatial light modulator 61, a transmissive liquid crystal display device, a reflective liquid crystal display device, a micromirror device, or the like can be used. That is, the variable mask 60 may be a device that transmits the second light source light SL2 in a desired pattern, or may be a device that reflects the second light source light SL2 in a desired pattern. Further, the variable mask 60 may absorb the unnecessary second light source light SL2, or may direct the unnecessary second light source light SL2 to other than the diffractive optical element 40.

  In the illumination device 10 shown in FIG. 9, the light source light SL emitted from the light source 15 is shaped by the shaping optical system 25. In the illustrated example, the light source light SL is widened by the shaping optical system 25. Next, the widened light source light SL is divided into a first light source light SL1 and a second light source light SL2 depending on whether or not it enters the variable mask 60. The first light source light SL1 is incident on the fixed diffractive optical element 45 of the diffractive optical element 40 without being affected by the variable mask 60. The second light source light SL2 is shaped into a desired pattern by the variable mask 60 and is incident on the variable diffractive optical element 50 of the diffractive optical element 40. As a result, the fixed illumination area Zf is illuminated by the first light source light SL1 diffracted by the fixed diffractive optical element 45, and is variably illuminated by the second light source light SL2 diffracted by the element diffractive optical element 51 of the variable diffractive optical element 50. The illumination area Zv is illuminated. The illumination pattern of the variable illumination region Zv is determined by which element diffractive optical element 51 of the variable diffractive optical element 50 is incident on the second light source light SL2. Therefore, by using the variable mask 60, the illumination pattern of the variable illuminated area Zv can be controlled.

  In the second embodiment described above, the illumination device 10 emits light from the light source 15 and the light source 15 outside the optical path of the first light source light SL1 out of the light emitted from the light source 15. Of the received light, the variable mask 60 positioned on the optical path of the second light source light SL2, the fixed diffractive optical element 45 that diffracts the first light source light SL1, and the variable diffractive optical element 50 that diffracts the second light source light SL2. ,have. The variable mask 60 can change the incident area ia of the second light source light SL2 on the variable diffractive optical element 50. The variable diffractive optical element 50 includes a plurality of element diffractive optical elements 51. According to the second embodiment, the variable mask 60 can irradiate only the desired element diffractive optical element 51 included in the variable diffractive optical element 50 with the second light source light SL2. At the same time, the fixed diffractive optical element 45 is continuously irradiated with the first light source light SL1. That is, by using the variable mask 60, the diffraction by the element diffractive optical element 51 is performed while illuminating the fixed illuminated area Zf using the diffracted light from the diffractive optical element 40 without using the scanning device 30. The desired element illuminated area Zve can be illuminated with light. Therefore, vibration, noise, heat generation, etc. associated with the operation of the scanning device 30 and a failure risk of the scanning device 30 can be avoided.

  Various modifications can be made to the above-described second embodiment. For example, in the diffractive optical element 40, the area ratios of the fixed diffractive optical element 45 and the variable diffractive optical element 50 can be changed to adjust the brightness of the illuminated regions Zf and Zv. In addition, the arrangement, number, area ratio, and the like of the plurality of element diffractive optical elements 51 included in the variable diffractive optical element 50 can be appropriately changed.

  In the above-described second embodiment, the example in which the light source light SL emitted from the light source 15 is directly incident on the shaping optical system 25 has been described. However, the present invention is not limited to this example. As shown in FIG. 17, the light source light SL emitted from the light source 15 may be conveyed by the optical fiber 16. In the example shown in FIG. 17, the light source light SL emitted from the end portion 16 a of the optical fiber 16 is incident on the lens 27 of the shaping optical system 25. As shown in FIG. 17, the light source light SL emitted from the end portion 16a of the optical fiber 16 forms a divergent light beam. For this reason, in the example shown in FIG. 17, the beam expander 26 of the shaping optical system 25 is not used. However, when the degree of divergence of the light source light SL emitted from the optical fiber 16 is low, a beam expander 26 of the shaping optical system 25 can be provided.

<Third Embodiment>
Next, a third embodiment will be described with reference to FIGS. In the following description and the drawings used in the following description, parts that can be configured in the same manner as in the above-described first or second embodiment will be described with respect to corresponding parts in the above-described first or second embodiment. The same reference numerals as those used are used, and redundant description is omitted.

  FIG. 11 is a schematic diagram illustrating an example of the illumination device 10 according to the third embodiment. As shown in FIG. 11, in the third embodiment, the illumination device 10 includes a light source 15 that emits light, a variable shaping optical system 70 that shapes light emitted from the light source 15, that is, the light source light SL, and shaping. And a diffractive optical element 40 that diffracts the generated light source light SL. Hereinafter, each component of the illumination device 10 will be described.

  The light source 15 can be configured in the same manner as in the first or second embodiment.

  The variable shaping optical system 70 shapes the light source light SL. In other words, the variable shaping optical system 70 shapes the shape of the cross section perpendicular to the optical axis of the light source light SL and the three-dimensional shape of the light flux of the light source light SL. In the illustrated example, the variable shaping optical system 70 widens the light source light SL. As shown in FIG. 11, the variable shaping optical system 70 includes a beam expander 26 and a lens 27 in the order along the optical path of the light source light SL. The beam expander 26 shapes the laser light emitted from the light source 15 into a divergent light beam. The lens 27 reshapes the divergent light beam generated by the beam expander 26 into a parallel light beam, or closes the divergent light beam to a parallel light beam while suppressing the degree of divergence. The variable shaping optical system 70 may use a normal lens so that the incident area ia of the light source light SL on the diffractive optical element 40 is circular, or the incident area ia is rectangular. As described above, a cylindrical lens may be used. The diffractive optical element 40 shown in FIG. 12 described later corresponds to the incident region ia having a rectangular shape in plan view.

  In the illustrated example, the lens 27 of the variable shaping optical system 70 is supported by a moving support 76. The moving support 76 moves the lens 27 in a direction parallel to the optical axis od of the lens 27. In the illustrated example, the lens 27 approaches the beam expander 26 from the first position (the position indicated by the solid line in FIG. 11) where the divergent light beam from the beam expander 26 can be converted into a parallel light beam. It can move between the second position (the position of the two-dot chain line in FIG. 11). In the example shown in FIG. 11, the incident region ia of the light source light SL on the diffractive optical element 40 gradually increases as the moving support 76 moves the lens 27 from the first position toward the second position. It gets bigger. In other words, the variable shaping optical system 70 can variably shape the light emitted from the light source 15 and adjust the size of the incident region ia on the diffractive optical element 40.

  FIG. 12 shows an example of a diffractive optical element 40 that can be applied to the illumination device 10 of FIG. 11 as a plan view. The diffractive optical element 40 includes a fixed diffractive optical element 45 as a center, and a variable diffractive optical element 50 surrounding the fixed diffractive optical element 45 in a circumferential shape. The fixed diffractive optical element 45 coincides with the incident area ia into which the light source light SL is incident in a state where the lens 27 is disposed at the first position described above.

  The variable diffractive optical element 50 is divided into two element diffractive optical elements 51 in the illustrated example. The first element diffractive optical element 51 a is adjacent to the fixed diffractive optical element 45 and surrounds the fixed diffractive optical element 45 in a circumferential shape. The second element diffractive optical element 51b is adjacent to the first element diffractive optical element 51a and surrounds the first element diffractive optical element 51a circumferentially. When the fixed diffractive optical element 45 starts to move from the first position to the second position, the light source light SL enters the first element diffractive optical element 51a in addition to the fixed diffractive optical element 45. . Further, when the fixed diffractive optical element 45 approaches the second position, the light source light SL is incident on the second element diffractive optical element 51b in addition to the fixed diffractive optical element 45 and the first element diffractive optical element 51a. Become.

  FIG. 13 shows an example of an illuminated area Z illuminated by the diffractive optical element 40. In the example shown in FIG. 13, the fixed illumination area Zf illuminated by the diffracted light from the fixed diffractive optical element 45 is a wide area extending in front of the illumination device 10. The variable illuminated region Zv illuminated by the diffracted light from the variable diffractive optical element 50 includes a region further ahead of the fixed illuminated region Zf. The variable illuminated area Zv is divided into two corresponding to each element diffractive optical element 51, and includes first and second element illuminated areas Zve1 and Zve2. The first element illuminated area Zve1 illuminated by the diffracted light from the first element diffractive optical element 51a is located adjacent to the fixed illuminated area Zf and in front of the fixed illuminated area Zf. The second element illuminated area Zve2 illuminated by the diffracted light from the second element diffractive optical element 51b is located adjacent to the first element illuminated area Zve1 and in front of the first element illuminated area Zve1.

  However, the illuminated area Z shown in FIG. 13 is merely an example. In the example shown in FIG. 13, an example in which the fixed illumination area Zf and the variable illumination area Zv do not overlap each other is shown, but at least a portion may overlap, and either one is included in the other. You may make it do, and also it may be the same. Further, the fixed illumination area Zf and the variable illumination area Zv do not need to be in contact with each other and may be separated from each other. Similarly, the plurality of element illuminated areas Zve do not overlap in the illustrated example, but may overlap at least in part, or any one of them may be included in another one. Further, any one of them may be the same as the other one. Further, the plurality of element illuminated areas Zve do not have to be in contact with each other, and may be separated from each other.

  In the illumination device 10 shown in FIG. 11, the light source light SL emitted from the light source 15 is variably shaped by the variable shaping optical system 70. For example, when the lens 27 is disposed at the first position indicated by the solid line in FIG. 11, the variable shaping optical system 70 first converts the light source light SL into a divergent light beam by the beam expander 26, and then the lens 27. The light source light SL is converted from a divergent light beam into a parallel light beam. In the illustrated example, the parallel light beam enters the entire area of the fixed diffractive optical element 45 and does not enter the variable diffractive optical element 50. The fixed diffractive optical element 45 diffracts the light source light SL and directs it toward the fixed illuminated region Zf. Thereby, the fixed illuminated area Zf is illuminated by the light source light SL diffracted by the fixed diffractive optical element 45.

  The movement support 76 supports the lens 27 so as to be movable. The lens 27 arranged at the position indicated by the two-dot chain line in FIG. 11 shapes the divergent light beam shaped by the beam expander 26 and weakens the degree of divergence. The light source light SL whose degree of divergence is weakened by the lens 27 is applied not only to the fixed diffractive optical element 45 of the variable diffractive optical element 50 but also to the first and second element diffractive optical elements 51a and 51b of the variable diffractive optical element 50. Incident. At this time, the fixed diffractive optical element 45 diffracts the light source light SL and directs it toward the fixed illuminated area Zf. Similarly, the first element diffractive optical element 51a diffracts the light source light SL and directs it toward the first element illuminated region Zve1, and the second element diffractive optical element 51b diffracts the light source light SL and emits the second element illuminated. Turn to the area Zve2. Thereby, the fixed illuminated area Zf is illuminated with the diffracted light from the fixed diffractive optical element 45, the first element illuminated area Zve1 is illuminated with the diffracted light from the first element diffractive optical element 51a, and the first The two-element illuminated area Zve2 is illuminated by the diffracted light from the second element diffractive optical element 51b.

  Further, as the moving support 76 moves the lens 27 from the first position toward the second position, the incident area ia of the light source light SL on the diffractive optical element 40 is enlarged. When the lens 27 is positioned between the first position and the second position, the light source light SL is incident on the fixed diffractive optical element 45 and the first element diffractive optical element 51a, but not incident on the second element diffractive optical element 51b. It can also be done. At this time, only the fixed illuminated area Zf and the first element illuminated area Zve1 are illuminated, and the second element illuminated area Zve2 is not illuminated.

  That is, in the example shown in FIGS. 11 to 13, the fixed diffractive optical element 45 and the element diffractive optical element 51 of the variable diffractive optical element 50 are arranged adjacent to each other in order. The regions Zf and Zve that are illuminated by the diffracted light from the elements 45 and 51 are also arranged adjacent to each other in order. As a result, by moving the lens 27 from the first position to the second position, it is possible to gradually expand the incident area ia of the light source light SL on the diffractive optical element 40 and to illuminate farther areas. . Conversely, by moving the lens 27 from the second position to the first position, the incident area ia of the light source light SL on the diffractive optical element 40 is gradually reduced, and the illuminated area is reduced to an adjacent area. can do.

  In the third embodiment described above, the lighting 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 source light SL emitted from the light source 15. A variable shaping optical system 70 is provided between the light source 15 and the diffractive optical element 40 along the optical path. The variable shaping optical system 70 variably shapes the light source light SL emitted from the light source 15 and adjusts the size of the incident region ia on the diffractive optical element 40. The diffractive optical element 40 includes a fixed diffractive optical element 45 on which the light source light SL emitted from the light source 15 enters regardless of the size of the incident area ia on the diffractive optical element 40, and an incident area on the fixed diffractive optical element 45. and a variable diffractive optical element 50 on which light emitted from the light source 15 is incident when ia is enlarged. According to such a third embodiment, the variable shaping optical system 70 controls the presence or absence of light irradiation to the variable diffractive optical element 50. On the other hand, the fixed diffractive optical element 45 is continuously irradiated with light. That is, by using the variable diffractive optical element 50, the variable diffractive optical element 50 is used while illuminating the fixed illuminated region Zf using the diffracted light from the fixed diffractive optical element 45 without using the scanning device 30. It is possible to switch between illumination and non-illumination of the variable illuminated area Zv using the diffracted light at. Therefore, vibration, noise, heat generation, etc. associated with the operation of the scanning device 30 and a failure risk of the scanning device 30 can be avoided.

  In the third embodiment, the variable diffractive optical element 50 includes a plurality of element diffractive optical elements 51 having different diffraction characteristics. According to such an illuminating device 10, the variable shaping optical system 70 can irradiate only the desired element diffractive optical element 51 included in the variable diffractive optical element 50 with the light source light SL. At the same time, the variable diffractive optical element 50 continues to be irradiated with the first light source light SL1. That is, by using the variable diffractive optical element 50, the element diffractive optical element 51 is used while illuminating the fixed illuminated area Zf using the diffracted light from the fixed diffractive optical element 45 without using the scanning device 30. The desired element illuminated region Zve can be illuminated using the diffracted light at.

  Further, in the third embodiment, the variable shaping optical system 70 includes a lens 27. The lens 27 is movable in a direction parallel to the optical axis od of the lens 27. According to such an illuminating device 10, the presence or absence of irradiation of the light source light SL to the variable diffractive optical element 50 is controlled by moving the lens 27, and further, the desired diffractive optical element 50 includes a desired one. Only the element diffractive optical element 51 can be irradiated with the light source light SL. The lens 27 may be moved only when the irradiation pattern of the light source light SL to the variable diffractive optical element 50 is switched. Therefore, the vibration, noise, heat generation, etc. accompanying the movement of the lens 27 and the failure risk of the means 76 for moving the lens 27 are so small that they cannot be compared with the scanning device 30.

  Various modifications can be made to the third embodiment described above. Hereinafter, an example of modification will be described with reference to the drawings. In the following description and the drawings used in the following description, parts that can be configured in the same manner as in the above-described third embodiment are the same as those used for the corresponding parts in the above-described third embodiment. Reference numerals will be used, and redundant description will be omitted.

  In the third embodiment described above, the variable shaping optical system 70 has shown an example in which the incident area ia of the light source light SL on the diffractive optical element 40 is changed by moving the lens 27. Not limited. For example, in addition to the movement of the lens 27 or in place of the movement of the lens 27, the beam expander 26 may be movable as shown in FIG. 14, or a variable aperture 73 is provided as shown in FIG. Also good.

  In the example shown in FIG. 14, the beam expander 26 is supported by a movement support tool 77. In the illustrated example, the moving support 77 moves the beam expander 26 in a direction parallel to the optical axis od of the lens 27. The beam expander 26 has a third position (position indicated by a solid line in FIG. 14) where the light source light SL is collimated by the lens action of the lens 27, and a fourth position (FIG. 14) that approaches the lens 27 from this position. Between the two-dot chain line). In the example shown in FIG. 14, the incident region ia of the light source light SL on the diffractive optical element 40 becomes as the moving support 77 moves the beam expander 26 from the third position toward the fourth position. , Gradually getting bigger. That is, also in the example shown in FIG. 14, the variable shaping optical system 70 can variably shape the light emitted from the light source 15 and adjust the size of the incident region ia on the diffractive optical element 40.

  In such a modification shown in FIG. 14, the variable shaping optical system 70 includes a beam expander 26 that diverges the light source light SL emitted from the light source 15, and the beam expander 26 is movably supported. ing. According to such an illuminating device 10, the presence or absence of irradiation of the light source light SL to the variable diffractive optical element 50 is controlled by moving the beam expander 26, and further included in the variable diffractive optical element 50. Only the desired element diffractive optical element 51 can be irradiated with the light source light SL. The movement of the beam expander 26 may be performed only when the irradiation pattern of the light source light SL to the variable diffractive optical element 50 is switched. The vibration, noise, heat generation, and the like accompanying the movement of the beam expander 26 and the failure risk of the beam expander 26 are so small that they cannot be compared with the scanning device 30.

  In the example shown in FIG. 15, the variable stop 73 is disposed on the optical path of the light source light SL widened by the optical action of the beam expander 26 and the lens 27. The variable diaphragm 73 can transmit the light source light SL in the central region. On the other hand, the transmission of the light source light SL is restricted at the outer peripheral portion. The variable stop 73 can change the size of the central transmission region, and thereby the size of the incident region ia on the diffractive optical element 40 can be adjusted.

  In such a modification shown in FIG. 15, the variable shaping optical system 70 includes a variable diaphragm 73. According to such an illuminating device 10, the variable diaphragm 73 controls whether or not the variable diffractive optical element 50 is irradiated with light, and further, the desired element diffractive optical element 51 included in the variable diffractive optical element 50. Only the light source light SL can be irradiated. The operation of the variable diaphragm 73 may be performed only when the irradiation pattern to the variable diffractive optical element 50 is switched. Therefore, the vibration, noise, heat generation, etc. associated with the operation of the variable diaphragm 73 and the failure risk of the variable diaphragm 73 are so small that they cannot be compared with the scanning device.

  In the above-described third embodiment, the example in which the light source light SL emitted from the light source 15 is directly incident on the variable shaping optical system 70 has been described. However, the present invention is not limited to this example. As shown in FIG. 18, the light source light SL emitted from the light source 15 may be conveyed by the optical fiber 16. In the example shown in FIG. 18, the light source light SL emitted from the end portion 16 a of the optical fiber 16 is incident on the lens 27 of the variable shaping optical system 70. As shown in FIG. 18, the light source light SL emitted from the end 16a of the optical fiber 16 forms a divergent light beam. For this reason, in the example shown in FIG. 18, the beam expander 26 of the variable shaping optical system 70 is not used. However, when the degree of divergence of the light source light SL emitted from the optical fiber 16 is low, the beam expander 26 of the variable shaping optical system 70 can be provided. In the example shown in FIG. 18, the optical fiber 16 is applied to the illumination device 10 shown in FIG. 11, but the optical fiber 16 is also applied to the illumination device 10 shown in FIGS. 14 and 15. Can be applied.

  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.

Z illuminated area Zf fixed illuminated area Zv variable illuminated area Zve element illuminated area Zve1 first element illuminated area Zve2 second element illuminated area Zve3 third element illuminated area Zve4 fourth element illuminated area Zve5 fifth Element illuminated area SL Light source light SL1 First light source light SL2 Second light source light ia Incident area sp Scanning path od Optical axis 10 Illuminating device 11 Control unit 15 Light source 20 Dividing element 25 Shaping optical system 26 Beam expander 27 Lens 30 Scanning device 31 Reflector 35 Shutter 40 Diffractive optical element 45 Fixed diffractive optical element 50 Variable diffractive optical element 51 Element diffractive optical element 51a First element diffractive optical element 51b Second element diffractive optical element 51c Third element diffractive optical element 51d Fourth element diffractive element Optical element 51e Fifth element diffractive optical element 52 Dummy part 52a First element dummy part 52 The second element dummy portion 52c third element dummy portion 52d fourth element dummy portion 52e fifth element dummy unit 60 variable mask 61 spatial light modulator 70 variable shaping optical system 73 variable stop 76 moving support 77 moves support

Claims (9)

A light source that emits light;
A splitting element that splits light emitted from the light source into first light source light and second light source light;
A fixed diffractive optical element that diffracts the first light source light;
A variable diffractive optical element that diffracts the second light source light;
A scanning device that changes an incident position on the variable diffractive optical element by changing an optical path of the second light source light,
The variable diffractive optical element includes a plurality of element diffractive optical elements.   The illumination device according to claim 1, wherein the light source stops emission of light according to an operation of the scanning device.   The illumination apparatus according to claim 2, wherein the variable diffractive optical element includes a dummy part that regulates the progress of the second light source light to the illuminated area. A light source that emits light;
A variable mask positioned outside the optical path of the first light source light of the light source light emitted from the light source and on the optical path of the second light source light of the light source light;
A fixed diffractive optical element that diffracts the first light source light;
A variable diffractive optical element that diffracts the second light source light,
The variable mask can change an incident area of the second light source light on the variable diffractive optical element,
The variable diffractive optical element includes a plurality of element diffractive optical elements. A light source that emits light;
A diffractive optical element that diffracts light emitted from the light source;
A variable shaping optical system positioned between the light source and the diffractive optical element along an optical path of light emitted from the light source,
The variable shaping optical system variably shapes light emitted from the light source, and adjusts the size of an incident region on the diffractive optical element,
The diffractive optical element includes a fixed diffractive optical element on which light emitted from the light source is incident regardless of a size of an incident area on the diffractive optical element, and an incident area on the diffractive optical element is enlarged. And a variable diffractive optical element on which light emitted from the light source enters.   The illumination device according to claim 5, wherein the variable diffractive optical element includes a plurality of element diffractive optical elements. The variable shaping optical system includes a lens,
The illumination device according to claim 5 or 6, wherein the lens is supported so as to be movable in a direction parallel to the optical axis of the lens. The variable shaping optical system includes a beam expander for diverging light emitted from the light source,
The lighting device according to claim 5, wherein the beam expander is supported so as to be movable.   The illumination apparatus according to claim 5, wherein the variable shaping optical system includes a variable stop.

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