JP6872167B2 - Lighting device - Google Patents

Description

The present disclosure relates to a lighting device.

For example, as disclosed in Patent Document 1, a lighting device including a light source and a diffractive optical element is known. The lighting device disclosed in Patent Document 1 includes a light source, a scanning device, and a diffractive optical element. The scanning device changes the traveling direction of the light emitted from the light source over time. As a result, the light emitted from the light source is incident on the diffractive optical element so as to scan on the diffractive optical element. The diffractive optical element includes a plurality of element holograms having different diffraction characteristics from each other. The light source switches between emitting light and stopping light emission according to the operation of the scanning device, that is, according to the position of incidence on the diffractive optical element. According to this lighting device, the area irradiated with the illumination light can be switched to a desired pattern.

Japanese Unexamined Patent Publication No. 2016-110813

By the way, in many cases where lighting is performed using a lighting device, there is always a region to be illuminated. For example, in a car headlamp, it is possible to constantly illuminate the front area and, if necessary, illuminate the left and right areas located on the left and right of the front area and the distant area further ahead of the front area in addition to this front area. desired. In a conventional lighting device, the light source emits light at a timing when the light scans on an element hologram that diffracts the light into a region to be illuminated at all times. However, targeting even an element hologram to which light is continuously directed is made more prominent in vibration, noise, heat generation, etc. associated with the operation of the scanning device, and means that 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 of the present disclosure is to reduce the burden associated with the application of the scanning device to the lighting device.

The first lighting device according to the present invention is
A light source that emits light and
A dividing element that divides the light emitted from the light source into a first light source light and a second light source light.
A fixed diffractive optical element that diffracts the first light source light,
A variable diffraction optical element that diffracts the second light source light,
A scanning device for changing the optical path of the second light source light to change the incident position on the variable diffraction optical element is provided.
The variable diffraction optical element includes a plurality of element diffraction optical elements.

In the first lighting device according to the present invention, the light source may stop emitting light according to the operation of the scanning device.

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

The second lighting device according to the present invention is
A light source that emits light and
A variable mask located 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 diffraction optical element that diffracts the second light source light is provided.
The variable mask can change the incident region of the second light source light on the variable diffraction optical element.
The variable diffraction optical element includes a plurality of element diffraction optical elements.

The third lighting device according to the present invention is
A light source that emits light and
A diffractive optical element that diffracts the light emitted from the light source,
A variable shaping optical system located between the light source and the diffractive optical element along the optical path of light emitted from the light source is provided.
The variable shaping optical system variably shapes the light emitted from the light source, adjusts the size of the incident region on the diffractive optical element, and adjusts the size of the incident region.
The diffractive optical element includes a fixed diffractive optical element to which light emitted from the light source is incident regardless of the size of the incident region on the diffractive optical element, and when the incident region on the diffractive optical element is expanded. Includes a variable diffractive optical element into which light emitted from the light source is incident.

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

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

In the third illuminating device according to the present invention, the variable shaping optical system includes a beam expander that diverges the light emitted from the light source.
In the third lighting device according to the present invention, the beam expander may be movably supported.

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

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

FIG. 1 is a diagram for explaining the first embodiment of the present disclosure, and is a schematic view showing a lighting device. FIG. 2 is a plan view showing a diffractive optical element of the lighting device of FIG. FIG. 3 is a diagram showing an example of an illuminated area illuminated by the illumination device of FIG. FIG. 4 is a diagram showing an example of an irradiation pattern of the element diffraction optical element included in the variable diffraction optical element. FIG. 5 is a diagram showing an example of an illumination pattern of an illuminated region when the variable diffraction optical element is irradiated with the light source light by the irradiation pattern of FIG. FIG. 6 is a diagram showing another example of the irradiation pattern of the element diffraction optical element included in the variable diffraction optical element. FIG. 7 is a diagram showing an example of an illumination pattern of an illuminated region when the variable diffraction optical element is irradiated with the light source light by the irradiation pattern of FIG. FIG. 8 is a diagram showing another example of the illuminated area illuminated by the illumination device of FIG. FIG. 9 is a diagram for explaining a second embodiment of the present disclosure, and is a schematic view showing a lighting device. FIG. 10 is a plan view showing a diffractive optical element of the lighting device of FIG. FIG. 11 is a diagram for explaining a third embodiment of the present disclosure, and is a schematic view showing a lighting device. FIG. 12 is a plan view showing a diffractive optical element of the lighting device of FIG. FIG. 13 is a diagram showing 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 view showing a modified example of the lighting device. FIG. 15 is a diagram corresponding to FIG. 11 and is a schematic view showing another modification of the lighting device. FIG. 16 is a diagram corresponding to FIG. 1 and is a schematic view showing a modified example of the lighting device. FIG. 17 is a diagram corresponding to FIG. 9, and is a schematic view showing a modified example of the lighting device. FIG. 18 is a diagram corresponding to FIG. 11 and is a schematic view showing a modified example 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, the scale, aspect ratio, etc. are appropriately changed from those of the actual product and exaggerated for the convenience of illustration and comprehension.

In addition, the terms such as "parallel", "orthogonal", and "same", and the values of length and angle, etc., which specify the shape and geometric conditions and their degrees as used in the present specification, are strictly referred to. It is interpreted to include the range in which similar functions can be expected, without being bound by any meaning.

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

Such a lighting device 10 can be used as a lighting device for a moving body such as a car or a ship in various fields. Then, in the plurality of embodiments described below, a device for dealing with a problem that has existed in the past, specifically, vibration, noise, heat generation, etc. associated with the operation of the scanning device can be effectively suppressed, and Ingenuity has been made to reduce the risk of failure of the scanning device.

<First Embodiment>
First, the first embodiment will be described with reference to FIGS. 1 to 8.

FIG. 1 is a schematic view showing an example of the lighting device 10 according to the first embodiment. As shown in FIG. 1, in the first embodiment, the lighting 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. I'm out. The lighting device 10 shown in FIG. 1 includes a dividing element 20 that divides 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 first. It further includes a scanning device 30 that adjusts 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 heads toward the fixed illuminated region Zf, and the diffracted light diffracted by the variable diffracted optical element 50 heads toward the variable illuminated region 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. The laser light projected from the laser light source has excellent straightness and is suitable as light for illuminating the illuminated area Z with high accuracy.

The illustrated light source 15 includes a single laser light source. Therefore, in the illustrated example, the illuminated region 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, It may be directed to 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 optics 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. When the light source 15 includes a laser light source that emits light in the same wavelength range, the illuminated region Z can be brightly illuminated.

The dividing element 20 divides 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. A half mirror can be used as such a dividing element 20. In the lighting device 10 shown in FIG. 1, the light source light SL reflected by the dividing element 20 made of a half mirror becomes the first light source light SL1, and the light source light SL transmitted through the dividing element 20 made of a half mirror is the second light source light SL1. It becomes the light source light SL2. The first light source light SL1 is diffracted by the fixed diffraction optical element 45 to illuminate the fixed illuminated region Zf. The second light source light SL2 is diffracted by the variable diffraction optical element 50 to illuminate the variable illuminated region Zv. By adjusting the reflectance of the dividing element 20 made of a half mirror, it is possible to adjust the amount of illumination light in the fixed illuminated area Zf and the variable illuminated area Zv. Further, as the dividing element 20, a combination of a dichroic mirror, a bandpass filter, a wave plate, a polarizing beam splitter and the like 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 dividing element 20 heads toward 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 first light source light SL1 in a cross section orthogonal to the optical axis and the three-dimensional shape of the light flux 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 flux. As shown in FIG. 1, the shaping optical system 25 has 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 luminous flux. The lens 27 reshapes the divergent luminous flux generated by the beam expander 26 into a parallel luminous flux. The shaping optical system 25 may use a normal lens so that the incident region of the first light source light SL1 on the fixed diffraction optical element 45 has a circular shape, or the incident region has a rectangular shape. As described above, a cylindrical lens may be used, or 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 is not constant. As a result, the second light source light SL2 emitted from the scanning device 30 scans on the incident surface of the variable diffraction optical element 50 of the diffraction optical element 40.

The scanning device 30 has a reflector 31 that can rotate around two rotation axes parallel to each other's intersecting directions. 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 heads toward the fixed diffraction optical element 45. By rotating the reflector 31 around two rotation axes, the second light source light SL2 can be two-dimensionally scanned on the incident surface of the variable diffraction optical element 50. The reflector 31 repeats a constant operation of rotating around two rotation axes at a constant cycle, for example. Then, the incident position of the second light source light SL2 on the diffractive optical element 40 changes with periodicity, and repeatedly moves, for example, 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 diffracting 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 region Z. Therefore, the illuminated area Z is illuminated by the diffracted light of 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 diffraction optical element 45 diffracts the first light source light SL1 of the light source light SL and directs it toward the fixed illuminated region Zf. On the other hand, the variable diffraction optical element 50 diffracts the second light source light SL2 of the light source light SL and directs it toward the variable illuminated region Zv. Further, the variable diffraction optical element 50 includes a plurality of element diffraction optical elements 51. Each element diffracting optical element 51 diffracts the second light source light SL2 and directs the diffracted light to different element illuminated regions Zve in the illustrated example.

FIG. 2 is a plan view showing the diffraction optical element 40. In the illustrated diffractive optical element 40, the fixed diffractive optical element 45 and the variable diffractive optical element 50 are arranged adjacent to each other. That is, the fixed diffraction optical element 45 and the variable diffraction optical element 50 are arranged so as to divide one optical element into a plane. The variable diffraction optical element 50 includes the first to fifth element diffraction 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 region Z illuminated by the diffractive optical element 40. In the example shown in FIG. 3, the fixed illuminated region Zf illuminated by the diffracted light from the fixed diffractive optical element 45 is a wide region extending in front of the illuminating device 10. The variable illuminated region Zv illuminated by the diffracted light from the variable diffractive optical element 50 includes a region located on both sides of the fixed illuminated region Zf and a region further in front of the fixed illuminated region Zf. The variable illuminated region Zv is divided into five corresponding to each element diffractive optical element 51, and includes the first to fifth element illuminated regions Zve1 to Zve5. The first element illuminated region Zve1 illuminated by the diffracted light from the first element diffracting optical element 51a is located on the left side of the fixed illuminated region Zf. The second element illuminated region Zve2 illuminated by the diffracted light from the second element diffracting optical element 51b is located to the left of the front region of the fixed illuminated region Zf. The third element illuminated region Zve3 illuminated by the diffracted light from the third element diffracted optical element 51c is located in the center of the front region of the fixed illuminated region Zf. The fourth element illuminated region Zve4 illuminated by the diffracted light from the fourth element diffracted optical element 51d is located to the right of the front region of the fixed illuminated region Zf. The fifth element illuminated region Zve5 illuminated by the diffracted light from the fifth element diffracting optical element 51e is located on the right side of the fixed illuminated region Zf.

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

However, the illuminated area Z shown in FIG. 3 is only an example. In the example shown in FIG. 3, the fixed illuminated area Zf and the variable illuminated area Zv are not overlapped, but at least a part of the fixed illuminated area Zf and the variable illuminated area Zv may be overlapped, and one of them may be included in the other. It may be the same, or even the same. Further, the fixed illuminated area Zf and the variable illuminated area Zv do not have 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 one of them may be included in the other. Alternatively, any one 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.

Further, the illuminated region Z shown in FIG. 3 is represented as a near-field illuminated region that is overlaid and illuminated by the diffractive optical element 40. Then, the light whose optical path is adjusted by the diffractive optical element 40 passes through the illuminated area Z and then illuminates an actual illumination range, for example, a predetermined range on the ground. Farfield's illumination range is often expressed as a diffusion angle distribution in angular space rather than the actual dimensions of the illuminated area. In the present specification, the terms "illuminated area", "fixed illuminated area", "variable illuminated area", and "element illuminated area" include not only the actual illuminated area (illuminated 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 forming 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 in various ways, 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 manufactured by using, for example, scattered light from an actual scattering plate as object light. More specifically, when the hologram photosensitive material, which is the base of the elements 40, 45, 50, and 51, is irradiated with reference light and object light composed of coherent light having mutual interference, interference fringes due to the interference of these lights are applied. Is formed on the hologram photosensitive material, and the elements 40, 45, 50, 51 are manufactured. As the reference light, laser light which is coherent light is used, and as the object light, for example, scattered light from an isotropic scattering plate which can be obtained at a low price is used.

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

Further, the complex interference fringe patterns formed on the elements 40, 45, 50, and 51 are formed by using the actual object light and the reference light, instead of forming them, the wavelength and the incident direction of the planned reproduction illumination light, and the incident direction. , 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, and 51 thus obtained are also called computer-generated holograms (CGH). For example, when the lighting device 10 is used to illuminate an illuminated area Z having a certain size on the ground or water surface, it is difficult to generate object light, and a computer composite hologram is used as an element 40. It is preferable to use it as 45, 50, 51.

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

Specific forms of the elements 40, 45, 50, 51 may be a volumetric hologram recording medium using a photopolymer, or a volumetric hologram recording medium of a type for recording using a photosensitive medium containing a silver salt material. Alternatively, it may be a relief type (embossed type) hologram recording medium. Further, the elements 40, 45, 50, 51 may be a transmissive type or a reflective type.

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

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

By the way, as shown in FIG. 1, the lighting 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 the 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 unit 11 controls the presence or absence of emission of the light source light SL based on the scanning timing by the scanning device 30, in other words, the incident position of the second light source light SL2 on the variable diffraction optical element 50. .. That is, the control unit 11 determines whether or not the second light source light SL2 is irradiated to each element diffractive optical element 51 according to the desired lighting pattern in the variable illuminated region Zv, and the light source light SL is emitted from the light source 15. It is controlled by switching the injection stop.

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

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

The first light source light SL1 is incident on the shaping optical system 25. In the shaping optical system 25, the optical path width of the first light source light SL1 is expanded. That is, the shaping optical system 25 shapes the first light source light SL1 so that the region occupied by the light is widened in the cross section orthogonal to the optical axis. The orthopedic optical system 25 has a beam expander 26 and a lens 27. As shown in FIG. 1, the beam expander 26 of the shaping optical system 25 diverges the light emitted from the light source 15 and converts it into a divergent luminous flux. Then, the lens 27 of the shaping optical system 25 collimates the divergent luminous flux into a parallel luminous flux. The first light source light SL1 shaped by the shaping optical system 25 is then incident on the fixed diffraction optical element 45 of the diffraction optical element 40. The fixed diffraction optical element 45 diffracts the first light source light SL1 and directs it toward the fixed illuminated region Zf. As a result, the fixed illuminated region Zf is illuminated by the diffracted light diffracted by the fixed diffracted optical element 45.

The second light source light SL2 is incident on the scanning device 30. The scanning device 30 changes the optical path of the second light source light SL2 with time. The change in the optical path of the second light source light SL2 is periodic. The second light source light SL2 is then incident on the variable diffraction optical element 50 of the diffraction optical element 40. The incident position of the second light source light SL2 on the variable diffraction optical element 50 moves along the scanning path sp. That is, the second light source light SL2 is incident on the variable diffraction optical element 50 so as to scan on the variable diffraction optical element 50. The variable diffraction optical element 50 includes a plurality of element diffraction optical elements 51 and a plurality of dummy portions 52. As shown in FIG. 2, the scanning path sp of the second light source light SL2 extends on the plurality of element diffraction optical elements 51 and the plurality of dummy portions 52. At this time, the control unit 11 switches whether or not the light source light SL is emitted from the light source 15 according to the 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 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, and the variable illuminated area Zv are illuminated. The fourth element illuminated area Zve4 is illuminated by the second light source light SL2.

Further, 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 in the variable illuminated area Zv, only the first element illuminated area Zve1 is illuminated by the second light source light SL2. Will be done.

As described above, the illuminating device 10 illuminates the inside of the variable diffraction optical element 50 in a desired pattern while continuing to illuminate the fixed diffraction optical element 45, or does not illuminate the variable diffraction optical element 50. The first light source light SL1 diffracted by the fixed diffraction optical element 45 and used for illuminating the fixed illuminated region 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. In this way, by omitting the fixed diffractive optical element 45 that diffracts the light toward the fixed illuminated region Zf that is always illuminated from the scanning path sp of the light source light SL on the diffracting optical element 40, the scanning path sp is eliminated. Can be shortened. As a result, vibration, noise, heat generation, etc. associated with the operation of the scanning device 30 can be effectively suppressed, and the risk of failure of the scanning device 30 can be effectively reduced.

By the way, the incident of the second light source light SL2 into each element diffractive optical element 51 is controlled according to the desired illumination pattern in the variable illuminated region Zv. In the illustrated example, the incident of the second light source light SL2 into each element diffractive optical element 51 is controlled by switching the emission and emission stop of the light source light SL from the light source 15. However, when the emission of the light source light SL from the light source 15 is stopped, the first light source light SL1 does not enter the fixed diffraction optical element 45 at the timing when the second light source light SL2 does not enter the variable diffraction optical element 50. The operation of the scanning device 30 is extremely fast, and the presence or absence of the illumination light incident on each region cannot be determined by the human eye. However, if the ratio of the period during which the light source 15 emits the light source light SL to the period for one cycle of the scanning device 30 fluctuates, there is a possibility that the fluctuation in brightness can be visually recognized by the human eye in the fixed illuminated region Zf. There is. Further, when any element illuminated area Zve in the variable illuminated area Zv is not illuminated, the light source light SL is not emitted from the light source 15, and the fixed diffraction optical element 45 cannot be illuminated. In order to deal with such a problem, the variable diffraction optical element 50 has, in addition to the element diffraction optical element 51, a dummy portion 52 that does not contribute to illumination in the illuminated area Z.

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 portion 52a and the fifth element dummy portion 52e, and the second element dummy portion 52b, the second element dummy portion 52b, The second light source light SL2 is not incident on the three-element dummy portion 52c and the fourth element dummy portion 52d. As a result, the light source 15 emits the light source light SL while scanning five regions, which is half of the ten regions obtained by dividing the variable diffraction optical element 50 into planes, and half of the ten regions. While scanning 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 of one cycle of the scanning device 30, the light source 15 emits the light source light SL for half a period. The emission of the light source light SL is stopped for the other half of the period.

Further, in the example shown in FIG. 6 for realizing the illumination pattern of FIG. 7, the second light source light SL2 is incident on the first element dummy portion 52a to the fourth element dummy portion 52d, and the fifth element dummy portion 52e The second light source light SL2 is not incident on the surface. Also in the example of FIG. 7, the light source 15 emits the light source light SL while scanning five regions which are half of the ten regions obtained by dividing the variable diffraction optical element 50 into planes, and the ten regions. While scanning the remaining five regions, which is half of them, 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 of one cycle of the scanning device 30, the light source 15 emits the light source light SL for half a period. The emission of the light source light SL is stopped for the other half of the period.

That is, in the illustrated example, the variable diffraction optical element 50 is provided with a dummy portion 52 that does not contribute to the illumination of the variable diffraction optical element 50, thereby stopping the emission of the light source light SL from the light source 15. , Brightness fluctuation in the fixed illuminated area Zf at the time of illumination can be effectively suppressed. In particular, in the illustrated example, since the variable diffraction optical element 50 includes the same number of dummy portions 52 as the element diffraction optical element 51, 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 diffraction optical elements 51, the brightness in the fixed illuminated region Zf at the time of 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 a first light source light SL1 and a second light source light SL2. The dividing element 20, the fixed diffraction optical element 45 that diffracts the first light source light SL1, the variable diffraction optical element 50 that diffracts the second light source light SL2, and the variable diffraction optical element 50 that changes the optical path of the second light source light SL2. It has a scanning device 30 that changes the incident position of the second light source light SL2 above. The variable diffraction optical element 50 includes a plurality of element diffraction optical elements 51. In such a first embodiment, the light source light SL is emitted from the light source 15 and the light source light SL is stopped depending on the operation of the scanning device 30, that is, according to the scanning positions on the plurality of dummy portions 52. By switching the above, the fixed illuminated area Zf is illuminated by the diffracted light of the fixed diffracted optical element 45, and the desired element illuminated area Zve is obtained by using the diffracted light of the variable diffractive optical element 50. Can be illuminated. The fixed diffraction 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, etc. associated with the operation of the scanning device 30 can be effectively suppressed, and the risk of failure of the scanning device 30 can be effectively suppressed. Can be reduced to.

Further, in the first embodiment, the variable diffraction optical element 50 includes a dummy portion 52 that prevents the second light source light SL2 from advancing to the illuminated region Z. In such a lighting device 10, the irradiation period of the second light source light SL2 on the dummy portion 52 can be adjusted according to the number of element diffractive optical elements 51 to which the second light source light SL2 is irradiated. As a result, 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 illuminated area Zf with a constant brightness regardless of the illumination pattern of the variable illuminated area Zv.

It is possible to make various changes 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, the parts that can be configured in the same manner as in the first embodiment described above are the same as the reference numerals used for the corresponding parts in the first embodiment described above. A reference numeral will be used, and duplicate description will be omitted.

In the first embodiment described above, an example in which the lighting device 10 brightly illuminates a predetermined illuminated area Z is shown, but the present invention is not limited to this. For example, as shown in FIG. 8, the lighting device 10 may function as a device that illuminates an area having a predetermined contour and therefore displays a predetermined contour. In the example shown in FIG. 8, the first element illuminated area Zve1 has an outer contour of an arrow pointing to the left, and the fifth element illuminated area Zve5 has an outer contour of an arrow pointing to the right. It is an area that has been used.

Further, in the first embodiment described above, the light source 15 controls the incident of the second light source light SL2 on each element diffractive optical element 51 by switching between the emission of the light source light SL and the emission stop of the light source light SL. , 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 shown by the alternate long and short dash 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 operate with a control signal from the control unit 11 to block the second light source light SL2 toward the scanning device 30 according to the operation of the scanning device 30. According to this example, the dummy portion 52 of the variable diffraction 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, an example in which the light source light SL emitted from the light source 15 is directly incident on the dividing element 20 is shown, 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 16a of the optical fiber 16 is shaped by the shaping element 17 and then incident on the dividing element 20. As the shaping element 17, for example, a collimator lens can be used. As shown in FIG. 16, the light source light SL emitted from the end portion 16a of the optical fiber 16 forms a divergent luminous flux. Then, the shaping element 17 composed of a collimator lens converts the divergent luminous flux into a parallel luminous flux. In the example shown in FIG. 16, the dividing element 20 divides the incident parallel light flux into the first light source light SL1 as the parallel light flux and the second light source light SL2 as the parallel light flux.

<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, the parts that can be configured in the same manner as in the first embodiment described above are the same as the reference numerals used for the corresponding parts in the first embodiment described above. A reference numeral will be used, and duplicate description will be omitted.

FIG. 9 is a schematic view showing an example of the lighting device 10 according to the second embodiment. As shown in FIG. 9, in the second embodiment, the lighting 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. I'm out. The lighting device 10 shown in FIG. 9 further has a shaping optical system 25 and a variable mask 60 in this order between the light source 15 along the optical path of the light source light SL and the diffractive optical element 40. Hereinafter, each component of the lighting device 10 will be described.

The light source 15 can be configured in the same manner as in the first embodiment. The shaping optical system 25 is provided on the optical path of the light source light SL and shapes the light source light SL. In the first embodiment, the shaping optical system 25 is provided on the optical path of the first light source light SL1 and shapes the first light source light SL1. Although it is different from the shaping optical system of the above, it can be configured in the same manner as in the first embodiment as a means for shaping light. In the example shown in FIG. 9, the shaping optical system 25 has 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 shown in FIG. 9, the variable mask 60 is arranged 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 whose optical path is not blocked by the variable mask 60 of the light source light SL is incident on 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 of the light source light SL changes the pattern and is incident on the variable diffraction optical element 50 of the diffractive optical element 40 as the second light source light SL2.

FIG. 10 shows an example of the diffractive optical element 40 that can be applied to the lighting device 10 of FIG. 9 as a plan view. The diffractive optical element 40 has a wide fixed diffractive optical element 45 in the lower region. Further, the diffractive optical element 40 has a variable diffractive optical element 50 in a region above the fixed diffractive optical element 45. The variable diffraction optical element 50 has a plurality of element diffraction optical elements 51 by being divided into planes in the width direction. In the example shown in FIG. 10, the variable diffraction optical element 50 includes five element diffraction optical elements 51. The first to fifth element diffraction optical elements 51a to 51e included in the variable diffraction optical element 50 have different diffraction characteristics. The diffracted light diffracted in each of the regions 45, 50, and 51 of the diffractive optical element 40 is directed toward the illuminated region Z to illuminate 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 in FIG. 3, and the second light source light SL2 diffracted by the second element diffractive optical element 51b. However, the second element illuminated region Zve2 in FIG. 3 is illuminated, and the second light source light SL2 diffracted by the third element diffractometric optical element 51c illuminates the third element illuminated region Zve3 in FIG. The second light source light SL2 diffracted by the element diffractive optical element 51d illuminates the fourth element illuminated region Zve4 in 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 of the above may be illuminated.

In the second embodiment as in the first embodiment, the fixed illuminated area Zf and the variable illuminated area Zv may not overlap, or may overlap at least in a part. Either one may be included in the other, or they may be the same. Further, the fixed illuminated area Zf and the variable illuminated area Zv do not have to be in contact with each other and may be separated from each other. Similarly, the plurality of element illuminated areas Zve may not overlap, may overlap at least in part, or one of them may be included in the other. , Furthermore, any one 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 region ia of the second light source light SL2 on the variable diffraction optical element 50 (see FIG. 9). As the variable mask 60, various devices capable of adjusting the incident region ia of the second light source light SL2 on the variable diffraction optical element 50 can be adopted. Typically, the 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 lighting 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 the light source light SL is incident on 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 diffraction optical element 50 of the diffraction optical element 40. As a result, the fixed illuminated area Zf is illuminated by the first light source light SL1 diffracted by the fixed diffractive optical element 45, and the variable object is variably covered 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 illuminated region Zv is determined by which element diffraction optical element 51 of the variable diffraction optical element 50 is incident with the second light source light SL2. Therefore, by using the variable mask 60, it is possible to control the illumination pattern of the variable illuminated region Zv.

In the second embodiment described above, the lighting device 10 is outside the optical path of the light source 15 that emits light and the first light source light SL1 of the light emitted from the light source 15, and emits light from the light source 15. A variable mask 60 located on the optical path of the second light source light SL2, a fixed diffraction 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. ,have. The variable mask 60 can change the incident region ia of the second light source light SL2 on the variable diffraction optical element 50. The variable diffraction optical element 50 includes a plurality of element diffraction optical elements 51. According to such a 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 diffraction optical element 45 is continuously irradiated with the first light source light SL1. That is, by using the variable mask 60, the fixed illuminated region Zf is illuminated by the diffracted light of the diffractive optical element 40 without using the scanning device 30, and at the same time, diffraction by the element diffractive optical element 51 is performed. Light can be used to illuminate the desired element illuminated area Zve. Therefore, vibration, noise, heat generation, etc. associated with the operation of the scanning device 30 and the risk of failure of the scanning device 30 can be avoided.

It is possible to make various changes to the second embodiment described above. For example, in the diffractive optical element 40, the area ratio of the fixed diffractive optical element 45 and the variable diffractive optical element 50 can be changed to adjust the brightness of each illuminated region Zf, Zv. Further, the arrangement, quantity, area ratio, etc. of the plurality of element diffractive optical elements 51 included in the variable diffractive optical element 50 can be appropriately changed.

Further, in the second embodiment described above, an example in which the light source light SL emitted from the light source 15 is directly incident on the shaping optical system 25 is shown, but 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 16a 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 luminous flux. Therefore, 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, it is possible to provide the beam expander 26 of the shaping optical system 25.

<Third embodiment>
Next, a third embodiment will be described with reference to FIGS. 11 to 15. In the following description and the drawings used in the following description, the parts that can be configured in the same manner as the above-mentioned first or second embodiment are referred to the corresponding parts in the above-mentioned first or second embodiment. The same code as the code used will be used, and duplicate description will be omitted.

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

The light source 15 may 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 light source light SL in a cross section orthogonal to the optical axis 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 has 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 luminous flux. The lens 27 reshapes the divergent luminous flux generated by the beam expander 26 into a parallel luminous flux, or suppresses the degree of divergence and brings it closer to the parallel luminous flux. The variable shaping optical system 70 may use a normal lens so that the incident region ia of the light source light SL on the diffractive optical element 40 has a circular shape, or the incident region ia has a rectangular shape. As described above, a cylindrical lens may be used. The diffractive optical element 40 shown in FIG. 12, which will be described later, corresponds to the incident region ia having a rectangular shape in a plan view.

In the illustrated example, the lens 27 of the variable shaping optical system 70 is supported by the 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 of the solid line in FIG. 11) capable of converting the divergent luminous flux from the beam expander 26 into a parallel luminous flux. It is possible to move between the second position (the position of the alternate long and short dash line in FIG. 11). In the example shown in FIG. 11, as the moving support 76 moves the lens 27 from the first position to the second position, the incident region ia of the light source light SL on the diffractive optical element 40 gradually increases. It gets bigger. That is, 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 the diffractive optical element 40 that can be applied to the lighting device 10 of FIG. 11 as a plan view. The diffractive optical element 40 has a fixed diffractive optical element 45 as a center and a variable diffractive optical element 50 that surrounds the fixed diffractive optical element 45 in a circumferential shape. The fixed diffraction optical element 45 coincides with the incident region ia where the light source light SL is incident in a state where the lens 27 is arranged at the first position described above.

The variable diffraction optical element 50 is divided into two element diffraction optical elements 51 in the illustrated example. The first element diffractive optical element 51a 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 in a circumferential shape. When the fixed diffractive optical element 45 starts moving from the first position to the second position described above, the light source light SL comes into contact with 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 the illuminated region Z illuminated by the diffractive optical element 40. In the example shown in FIG. 13, the fixed illuminated region Zf illuminated by the diffracted light from the fixed diffractive optical element 45 is a wide region extending in front of the illuminating device 10. The variable illuminated region Zv illuminated by the diffracted light from the variable diffractive optical element 50 includes a region further in front of the fixed illuminated region Zf. The variable illuminated region Zv is divided into two corresponding to each element diffractive optical element 51, and includes the first and second element illuminated regions Zve1 and Zve2. The first element illuminated region Zve1 illuminated by the diffracted light from the first element diffracting optical element 51a is located adjacent to the fixed illuminated region Zf and in front of the fixed illuminated region Zf. The second element illuminated region Zve2 illuminated by the diffracted light from the second element diffracting optical element 51b is located adjacent to the first element illuminated region Zve1 and in front of the first element illuminated region Zve1.

However, the illuminated area Z shown in FIG. 13 is only an example. In the example shown in FIG. 13, the fixed illuminated area Zf and the variable illuminated area Zv are not overlapped, but at least a part of the fixed illuminated area Zf and the variable illuminated area Zv may be overlapped, and one of them may be included in the other. It may be the same, or even the same. Further, the fixed illuminated area Zf and the variable illuminated area Zv do not have 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 one of them may be included in the other. Alternatively, any one 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 lighting 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 arranged at the first position shown 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. Converts the light source light SL from a divergent light beam to a parallel light beam. In the illustrated example, the parallel light flux is incident on the entire fixed diffraction optical element 45 and not on the variable diffraction optical element 50. The fixed diffraction optical element 45 diffracts the light source light SL and directs it toward the fixed illuminated region Zf. As a result, the fixed illuminated area Zf is illuminated by the light source light SL diffracted by the fixed diffracting optical element 45.

The moving support 76 supports the lens 27 so as to be movable. The lens 27 arranged at the position shown by the alternate long and short dash line in FIG. 11 shapes the divergent luminous flux 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 diffraction optical element 45 of the variable diffraction optical element 50 but also to the first and second element diffraction optical elements 51a and 51b of the variable diffraction optical element 50. Incident. At this time, the fixed diffraction optical element 45 diffracts the light source light SL and directs it toward the fixed illuminated region Zf. Similarly, the first element diffracting optical element 51a diffracts the light source light SL toward the first element illuminated region Zve1, and the second element diffracting optical element 51b diffracts the light source light SL to illuminate the second element. Aim at region Zve2. As a result, the fixed illuminated area Zf is illuminated by the diffracted light of the fixed diffractive optical element 45, the first element illuminated area Zve1 is illuminated by the diffracted light of the first element diffracted optical element 51a, and the first element is illuminated. The two-element illuminated region Zve2 is illuminated by the diffracted light in the second-element diffractive optical element 51b.

Further, as the moving support 76 moves the lens 27 from the first position to the second position, the incident region ia of the light source light SL on the diffractive optical element 40 expands. When the lens 27 is located between the first position and the second position, the light source light SL is incident on the fixed diffraction optical element 45 and the first element diffraction optical element 51a, and is not incident on the second element diffraction optical element 51b. You can also do it. 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 examples shown in FIGS. 11 to 13, the element diffraction optical elements 51 of the fixed diffraction optical element 45 and the variable diffraction optical element 50 are arranged adjacent to each other in order. Further, the regions Zf and Zve to be illuminated by the diffracted light in each of 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, the incident region ia of the light source light SL on the diffractive optical element 40 is gradually expanded, and it becomes possible to illuminate a farther region. .. Conversely, by moving the lens 27 from the second position to the first position, the incident region ia of the light source light SL on the diffractive optical element 40 is gradually reduced, and the illuminated region is reduced to a close region. can do.

In the third embodiment described above, the lighting device 10 comprises a light source 15 that emits light, a diffractive optical element 40 that diffracts the light emitted from the light source 15, and a light source light SL emitted from the light source 15. It has a variable shaping optical system 70 located 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 is incident regardless of the size of the incident region ia on the diffractive optical element 40, and an incident region on the fixed diffractive optical element 45. It includes a variable diffraction optical element 50 into which the light emitted from the light source 15 is incident when the ia is enlarged. According to the third embodiment as described above, the variable shaping optical system 70 controls the presence or absence of light irradiation to the variable diffraction optical element 50. On the other hand, the fixed diffraction optical element 45 continues to be irradiated with light. That is, by using the variable diffraction optical element 50, the variable diffraction optical element 50 is used while illuminating the fixed illuminated area Zf using the diffracted light of the fixed diffraction optical element 45 without using the scanning device 30. It is possible to switch between illuminating and non-illuminating the variable illuminated area Zv using the diffracted light in. Therefore, vibration, noise, heat generation, etc. associated with the operation of the scanning device 30 and the risk of failure of the scanning device 30 can be avoided.

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

Further, in the third embodiment, the variable shaping optical system 70 includes a lens 27. The lens 27 can move in a direction parallel to the optical axis od of the lens 27. According to such an illuminating device 10, by moving the lens 27, it is possible to control the presence or absence of irradiation of the light source light SL on the variable diffraction optical element 50, and further, a desired included in the variable diffraction optical element 50. It is possible to irradiate the light source light SL only on the element diffraction optical element 51. The movement of the lens 27 only needs to be performed when switching the irradiation pattern of the light source light SL on the variable diffraction optical element 50. Therefore, the vibration, noise, heat generation, etc. associated with the movement of the lens 27 and the risk of failure of the means 76 for moving the lens 27 are so small that they cannot be compared with the scanning device 30.

It is possible to make various changes 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, the parts that can be configured in the same manner as in the third embodiment described above are the same as the reference numerals used for the corresponding parts in the third embodiment described above. A reference numeral will be used, and duplicate description will be omitted.

In the third embodiment described above, the variable shaping optical system 70 shows an example in which the incident region 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 or instead of moving the lens 27, the beam expander 26 may be movable as shown in FIG. 14, or a variable diaphragm 73 may be provided as shown in FIG. May be good.

In the example shown in FIG. 14, the beam expander 26 is supported by a moving support 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 (the position of the solid line in FIG. 14) at which the light source light SL is collimated by the lens action of the lens 27 and a fourth position (the position of the solid line in FIG. 14) close to the lens 27 from that position (FIG. 14). It is possible to move between (the position of the alternate long and short dash line). In the example shown in FIG. 14, as the moving support 77 moves the beam expander 26 from the third position to the fourth position, the incident region ia of the light source light SL on the diffractive optical element 40 becomes. , 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, by moving the beam expander 26, it is possible to control the presence or absence of irradiation of the light source light SL on the variable diffraction optical element 50, and further, the variable diffraction optical element 50 includes the variable diffraction optical element 50. It is possible to irradiate the light source light SL only on the desired element diffraction optical element 51. The movement of the beam expander 26 may be performed only when the irradiation pattern of the light source light SL on the variable diffraction optical element 50 is switched. The vibration, noise, heat generation, etc. associated with the movement of the beam expander 26 and the risk of failure 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 diaphragm 73 is arranged 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 thereof. On the other hand, the transmission of the light source light SL is regulated in the outer peripheral portion. The variable diaphragm 73 can change the size of the central transmission region, whereby 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 aperture 73 controls the presence or absence of light irradiation on the variable diffraction optical element 50, and further, a desired element diffraction optical element 51 included in the variable diffraction optical element 50. It is possible to irradiate only the light source light SL. The operation of the variable diaphragm 73 may be performed only when the irradiation pattern of the variable diffraction optical element 50 is switched. Therefore, the vibration, noise, heat generation, etc. associated with the operation of the variable diaphragm 73 and the risk of failure of the variable diaphragm 73 are so small that they cannot be compared with the scanning device.

Further, in the third embodiment described above, an example in which the light source light SL emitted from the light source 15 is directly incident on the variable shaping optical system 70 is shown, but 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 16a 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 portion 16a of the optical fiber 16 forms a divergent luminous flux. Therefore, 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, it is possible to provide the beam expander 26 of the variable shaping optical system 70. Further, in the example shown in FIG. 18, the optical fiber 16 is applied to the lighting device 10 shown in FIG. 11, but the optical fiber 16 is also applied to the lighting device 10 shown in FIGS. 14 and 15. Can be applied.

Although a plurality of embodiments and modifications thereof have been described above, it is naturally 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 1st element Illuminated area Zve2 2nd element Illuminated area Zve3 3rd element Illuminated area Zve4 4th element Illuminated area Zve5 5th Element Illuminated area SL Source light SL1 First source light SL2 Second source light ia Incident area sp Scanning path od Optical axis 10 Lighting device 11 Control unit 15 Light source 20 Dividing element 25 Orthopedic 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 1st element diffractive optical element 51b 2nd element diffractive optical element 51c 3rd element diffractive optical element 51d 4th element diffraction Optical element 51e Fifth element diffractive optical element 52 Dummy part 52a First element dummy part 52b Second element dummy part 52c Third element dummy part 52d Fourth element dummy part 52e Fifth element dummy part 60 Variable mask 61 Spatial optical modulator 70 Variable shaping optical system 73 Variable aperture 76 Moving support 77 Moving support

Claims (1)

A light source that emits light and
A dividing element that divides the light emitted from the light source into a first light source light and a second light source light.
A fixed diffractive optical element that diffracts the first light source light,
A variable diffraction optical element that diffracts the second light source light,
A scanning device for changing the optical path of the second light source light to change the incident position on the variable diffraction optical element is provided.
The variable diffractive optical element is seen containing a plurality of elements diffractive optical element, and a dummy unit for regulating the progression to the illuminated region of the second source light, and
The light source is an illumination device that stops emitting light in response to the operation of the scanning device.

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