Patent Application
20240348752
The present disclosure relates to a projection device or the like that projects spatial light.
In optical space communication, a light signal propagating in a space (hereinafter also referred to as a spatial light signal) is transmitted or received without using a medium such as an optical fiber. An optical system such as a projection lens is used to project a spatial light signal that spreads and propagates in a space. In order to increase a projection angle of the spatial light signal, a projection lens having a short focal length is used.
PTL 1 discloses an image projection device using a refractive-type projection optical system. The device according to PTL 1 includes a projection optical system including a refractive optical system and a refractive/reflective optical element. The refractive optical system and the refractive/reflective optical element are arranged in order from an image display surface side toward a projection surface side. The refractive optical system includes a plurality of lenses. The refractive/reflective optical element includes a reflective surface element having a reflective surface, and a refractive medium part disposed closely to the reflective surface. The reflective surface element and the refractive medium part are configured as a single optical element by bonding them on their boundary surfaces.
In the projection optical system according to PTL 1, a distance of an optical path for passing through the refractive medium part is increased by a plurality of reflective surfaces of the reflective surface element of the refractive/reflective optical element. Therefore, it is possible to achieve a projection lens having a short focal length in which the refractive power of the entire refractive/reflective optical element is maintained while using a material having a small refractive index for the refractive medium part. However, the projection optical system according to PTL 1 has problems in that the refractive optical system needs to include a plurality of lenses, and the configurations of the reflective surface element and the refractive medium part of the refractive/reflective optical element are complicated. In addition, the projection optical system according to PTL 1 has many restrictions in designing a plurality of lenses included in the refractive optical system, the refractive/reflective optical element including the reflective surface element and the refractive medium part, and the like.
An object of the present disclosure is to provide a projection device or the like capable of projecting spatial light forming a desired image with a simple configuration.
A projection device according to an aspect of the present disclosure includes a light source, a spatial light modulator including a modulation portion irradiated with a beam emitted from the light source, the spatial light modulator modulating a phase of the emitted beam in the modulation portion, a control unit that sets a phase image for forming a desired image in the modulation portion of the spatial light modulator, and controls the light source in such a way that the modulation portion, in which the phase image is set, is irradiated with the beam, and a curved mirror having a curved reflective surface irradiated with a modulated beam modulated by the modulation portion of the spatial light modulator, the curved mirror reflecting the modulated beam on the reflective surface, and projecting a projection beam having a projection angle enlarged according to a curvature of the reflective surface.
According to the present disclosure, it is possible to provide a projection device or the like capable of projecting spatial light forming a desired image with a simple configuration.
Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, it should be noted that the example embodiments to be described below are limited to be technically preferable in carrying out the present invention, but the scope of the invention is not limited to the following example embodiments. Note that, in all the drawings used to describe the following example embodiments, the same reference signs are given to the same parts unless there is a particular reason. Furthermore, in the following example embodiments, the description of the same configurations and operations may not be repeated.
In all the drawings used to describe the following example embodiments, a direction of an arrow is an example, and does not limit a direction of light or a signal. In addition, in the drawings, a line indicating a trajectory of light is conceptual, and does not accurately indicate an actual traveling direction or state of light. For example, in the drawings, a change in traveling direction or state of light caused by refraction, reflection, diffraction, diffusion, or the like at an interface between air and a substance may be omitted, or a light flux may be expressed by a single line.
First, a projection device according to a first example embodiment will be described with reference to the drawings. The projection device according to the present example embodiment is used for optical space communication in which a light signal propagating in a space (hereinafter also referred to as a spatial light signal) is transmitted or received without using a medium such as an optical fiber. The projection device according to the present example embodiment is suitable for transmitting a spatial light signal to communication targets located at substantially the same height. The projection device according to the present example embodiment may be used for applications other than optical space communication as long as the projection device is used to project light propagating in a space.
The light source 11 includes an emitter 111 and a lens 112. The emitter 111 emits a laser beam 101 in a predetermined wavelength band according to the control of the control unit 17. The wavelength of the laser beam 101 emitted from the light source 11 is not particularly limited, and may be selected according to the application. For example, the emitter 111 emits a laser beam 101 in the visible or infrared wavelength band. For example, near-infrared light in the range of 800 to 900 nanometers (nm) can raise the laser class, thereby improving sensitivity by about a one-digit number as compared with the other wavelength bands. For example, a high-output laser light source can be used for infrared light in a wavelength band of 1.55 micrometers (μm). As an infrared laser light source in a wavelength band of 1.55 μm, an aluminum gallium arsenide phosphorus (AlGaAsP)-based laser light source, an indium gallium arsenide (InGaAs)-based laser light source, or the like can be used. The longer the wavelength of the laser beam 101 is, the larger the diffraction angle can be set and the higher the energy can be set.
The lens 112 enlarges the laser beam 101 emitted from the emitter 111 in accordance with a size of a modulation portion 130 of the spatial light modulator 13. The laser beam 101 emitted from the emitter 111 is enlarged by the lens 112 and emitted from the light source 11. A beam 102 emitted from the light source 11 travels toward the modulation portion 130 of the spatial light modulator 13.
The spatial light modulator 13 includes a modulation portion 130 irradiated with the beam 102. The modulation portion 130 of the spatial light modulator 13 is irradiated with the beam 102 emitted from the light source 11. In the modulation portion 130 of the spatial light modulator 13, a pattern according to an image to be displayed by a projection beam 105 is set according to the control of the control unit 17. The beam 102 incident on the modulation portion 130 of the spatial light modulator 13 is modulated according to the pattern set in the modulation portion 130 of the spatial light modulator 13. The modulated beam 103 modulated by the modulation portion 130 of the spatial light modulator 13 travels toward a reflective surface 150 of the curved mirror 15.
For example, the spatial light modulator 13 is achieved by a spatial light modulator using ferroelectric liquid crystal, homogeneous liquid crystal, vertical alignment liquid crystal, or the like. For example, the spatial light modulator 13 can be achieved by liquid crystal on silicon (LCOS). Alternatively, the spatial light modulator 13 may be achieved by a micro electro mechanical system (MEMS). The phase modulation-type spatial light modulator 13 can be operated to sequentially switch a location where a projection beam 105 is projected, thereby concentrating energy on an image portion. Therefore, in a case where the phase modulation-type spatial light modulator 13 is used, an image can be displayed brighter than those in the other methods if the output of the light source 11 is the same as those in the other methods.
The modulation portion 130 of the spatial light modulator 13 is divided into a plurality of regions (also referred to as tiling). For example, the modulation portion 130 is divided into rectangular regions (also referred to as tiles) having a desired aspect ratio. A phase image is allocated to each of the plurality of tiles set in the modulation portion 130. Each of the plurality of tiles includes a plurality of pixels. A phase image corresponding to an image to be projected is set to each of the plurality of tiles. The phase images set to the plurality of tiles, respectively, may be the same or different.
A phase image is tiled to each of the plurality of tiles allocated to the modulation portion 130. For example, a phase image generated in advance is set to each of the plurality of tiles. When the modulation portion 130 is irradiated with the beam 102 in a state where the phase images are set to the plurality of tiles, a modulated beam 103 that forms an image corresponding to a phase image of each tile is emitted. A larger number of tiles set in the modulation portion 130 make it possible to display a clearer image, but a smaller number of pixels of each tile results in a lower resolution. Therefore, the size and number of tiles set in the modulation portion 130 are set according to the application.
The shield 14 (also referred to as a first shield) is disposed between the spatial light modulator 13 and the curved mirror 15. In other words, the shield 14 is disposed on an optical path of the modulated beam 103 modulated by the modulation portion 130 of the spatial light modulator 13. The shield 14 is an aperture in which a slit-shaped opening is formed in a portion through which light forming a desired image passes. In other words, the shield 14 is a frame that shields an unnecessary light component included in the modulated beam 103 and defines an outer edge of a display area of the projection beam 105. The shield 14 allows light forming a desired image to pass therethrough and shields an unnecessary light component. For example, the shield 14 shields 0th-order light or a ghost image included in the modulated beam 103. For example, the opening of the shield 14 is formed in a rectangular shape, an elliptical shape, or a circular shape. As the shield 14, a 0th-order light shielding element (not illustrated) that shields 0th-order light may be used. The 0th-order light shielding element is an element in which a portion that absorbs/reflects light is formed. The 0th-order light shielding element is disposed on an optical path of 0th-order light. For example, a transparent element such as glass having a portion painted black so as not to transmit light can be used as the 0th-order light shielding element. Furthermore, a portion that shields 0th-order light included in the modulated beam 103 may be provided inside the opening of the shield 14.
The curved mirror 15 is a reflecting mirror having a curved reflective surface 150. The reflective surface 150 of the curved mirror 15 has a curvature in accordance with a projection angle of a projection beam 105. In the example of
The curved mirror 15 is disposed on an optical path of a modulated beam 103 with the reflective surface 150 facing the modulation portion 130 of the spatial light modulator 13. The reflective surface 150 of the curved mirror 15 is irradiated with the modulated beam 103 that has been modulated by the modulation portion 130 of the spatial light modulator 13 and has passed through the slit-shaped opening of the shield 14. The beam (the projection beam 105) reflected by the reflective surface 150 of the curved mirror 15 is projected after being enlarged at an enlargement ratio according to a curvature of the reflective surface 150. In the example of
The curved mirror 15 is disposed on an optical path of a modulated beam 103 with the reflective surface 150 facing the modulation portion 130 of the spatial light modulator 13. The reflective surface 150 of the curved mirror 15 is irradiated with the modulated beam 103 that has been modulated near the center of the modulation portion 130 of the spatial light modulator 13 and has passed through the slit-shaped opening of the shield 14. The modulated beam 103 modulated in a peripheral portion of the modulation portion 130 of the spatial light modulator 13 travels to a region deviated from the reflective surface 150 of the curved mirror 15. The beam (the projection beam 105) reflected by the reflective surface 150 of the curved mirror 15 is projected after being enlarged at an enlargement ratio according to a curvature of the reflective surface 150. In the example of
The control unit 17 controls the light source 11 and the spatial light modulator 13. For example, the control unit 17 is achieved by a microcomputer including a processor and a memory. The control unit 17 sets a phase image corresponding to an image to be projected in the modulation portion 130 in accordance with an aspect ratio of tiling set in the modulation portion 130 of the spatial light modulator 13. For example, the control unit 17 sets, in the modulation portion 130, a phase image corresponding to an image according to the application such as image display, communication, or distance measurement. The phase image of the image to be projected may be stored in advance in a storage unit (not illustrated). The shape and size of the image to be projected are not particularly limited.
The control unit 17 drives the spatial light modulator 13 in such a way as to change a parameter for determining a difference between a phase of the beam 102 emitted to the modulation portion 130 of the spatial light modulator 13 and a phase of the modulated beam 103 reflected by the modulation portion 130. The parameter for determining a difference between a phase of the beam 102 emitted to the modulation portion 130 of the spatial light modulator 13 and a phase of the modulated beam 103 reflected by the modulation portion 130 is, for example, a parameter regarding an optical characteristic such as a refractive index or an optical path length. For example, the control unit 17 adjusts the refractive index of the modulation portion 130 by changing the voltage applied to the modulation portion 130 of the spatial light modulator 13. The phase distribution of the beam 102 emitted to the modulation portion 130 of the phase modulation-type spatial light modulator 13 is modulated according to the optical characteristics of the modulation portion 130. The method of driving the spatial light modulator 13 by the control unit 17 is determined according to the modulation scheme of the spatial light modulator 13.
The control unit 17 drives the emitter 111 of the light source 11 in a state where a phase image corresponding to an image to be displayed is set in the modulation portion 130. As a result, the modulation portion 130 of the spatial light modulator 13 is irradiated with the beam 102 emitted from the light source 11 in accordance with a timing at which the phase image is set in the modulation portion 130 of the spatial light modulator 13. The beam 102 emitted to the modulation portion 130 of the spatial light modulator 13 is modulated by the modulation portion 130 of the spatial light modulator 13. The modulated beam 103 modulated by the modulation portion 130 of the spatial light modulator 13 is emitted toward the reflective surface 150 of the curved mirror 15.
The 0th-order light remover 16 includes a support element 161 and a light absorbing element 163. The support element 161 is an element that supports the light absorbing element 163. The light absorbing element 163 is fixed on an optical path of 0th-order light included in the modulated beam 103 by the support element 161. For example, the support element 161 is made of a material such as glass or plastic that easily transmits the modulated beam 103. In a case where the support element 161 is made of plastic, it is preferable to use a material having an entirely uniform surface with small phase unevenness so that retardation is less likely to occur. For example, a plastic material in which birefringence is suppressed is suitable for the support element 161. For example, the support element 161 may include a wire material for fixing the light absorbing element 163. For example, the peripheral edge of the support element 161 can be formed in a frame shape, a wire material is stretched inside the opening of the frame, and the light absorbing element 163 can be fixed by the stretched wire material. In a case where the support element 161 is made of a wire material, it is preferable to use a material that hardly deteriorates due to light so that the deterioration caused by the irradiation of the modulated beam 103 hardly occurs, the material being a wire material that is so thin as not to hinder the passage of the modulated beam 103. The light absorbing element 163 is held on the optical path of 0th-order light by the support element 161. For example, a black body such as carbon is used for the light absorbing element 163. When the wavelength of the laser beam 101 to be used is fixed, it is preferable to use the light absorbing element 163 made of a material that selectively absorbs light having the wavelength of the laser beam 101.
Next, a projection device according to a first modification of the present example embodiment will be described with reference to the drawings.
In the present modification, since the shield 14-1 is disposed at a stage after the curved mirror 15, there are few spatial restrictions due to positional relationships between the light source 11, the spatial light modulator 13, and the curved mirror 15. Therefore, the degree of freedom of the position where the shield 14-1 is disposed is high, and the entire device can be configured compactly. For example, the shield 14-1 may be disposed in a housing of the projection device 10-1. For example, a slit-shaped opening may be formed in the housing of the projection device 10-1 to function as the shield 14-1.
Next, a projection device according to a second modification of the present example embodiment will be described with reference to the drawings.
The curved mirror 15-2 is similar to the curved mirror 15 of the projection device 10 (
The shield 140 is disposed behind the curved mirror 15-2. The shield 140 is irradiated with the modulated beam 103 that is not reflected by the curved mirror 15-2. The modulated beam 103 emitted to the shield 140 includes 0th-order light and a ghost image. The shield 140 absorbs the emitted modulated beam 103. For example, a black body such as carbon is used for the shield 140. In addition, in a case where the wavelength of the laser beam 101 to be used is fixed, it is preferable to use the shield 140 including a material that selectively absorbs light having the wavelength of the laser beam 101. The shield 140 does not need to entirely absorb light, and may absorb light at least at a position where the modulated beam 103 is incident. For example, the shield 140 may be formed on an inner surface of a housing of the projection device 10-2.
In the configuration according to the present modification, a component for shielding light is not disposed on the optical path of the modulated beam 103 or the projection beam 105. Therefore, light utilization efficiency can be improved. In addition, according to the present modification, since there are few restrictions on spatial positional relationships between the light source 11, the spatial light modulator 13, and the curved mirror 15 resulting from the arrangement of the shield 140, the entire device can be configured compactly.
Next, a projection device according to a third modification of the present example embodiment will be described with reference to the drawings.
The axial direction of the curvature center of the reflective surface 150-3 of the curved mirror 15-3 is perpendicular to the paper surface of
The reflective surface 150-3 of the curved mirror 15-3 is irradiated with the modulated beam 103 that has been modulated by the modulation portion 130 of the spatial light modulator 13 and has passed through the slit-shaped opening of the shield 14. The beam (the projection beam 105-3) reflected by the reflective surface 150-3 of the curved mirror 15-3 is projected after being enlarged at an enlargement ratio according to a curvature of the reflective surface 150-3. In the example of
As described above, a projection device according to the present example embodiment includes a light source, a spatial light modulator, a shield, and a curved mirror. The light source emits a beam. The spatial light modulator includes a modulation portion irradiated with the beam emitted from the light source. The spatial light modulator modulates a phase of the emitted beam in the modulation portion. The control unit sets a phase image for forming a desired image in the modulation portion of the spatial light modulator. The control unit controls the light source in such a way that the modulation portion, in which the phase image is set, is irradiated with the beam. The shield (also referred to as a first shield) is disposed between the spatial light modulator and the curved mirror. The first shield has a slit opened to allow the modulated beam forming the desired image to pass therethrough, and shields an unnecessary light component included in the modulated beam. The curved mirror has a curved reflective surface irradiated with the modulated beam modulated by the modulation portion of the spatial light modulator. The curved mirror reflects the modulated beam on the reflective surface, and projects a projection beam having a projection angle enlarged according to a curvature of the reflective surface.
The projection device according to the present example embodiment can project a desired image while having a structure in which a projection optical system such as a projection lens is omitted. Furthermore, the projection device according to the present example embodiment removes an unnecessary light component included in a modulated beam. Therefore, the projection device according to the present example embodiment is capable of projecting spatial light forming a desired image from which an unnecessary light component has been removed with a simple configuration.
In an aspect of the present example embodiment, the control unit sets, in the modulation portion of the spatial light modulator, a composite image obtained by combining a virtual lens image for condensing the modulated beam forming the desired image on the reflective surface of the curved mirror with the phase image for forming the desired image. According to the present aspect, a mirror image of the desired image is formed on the reflective surface of the curved mirror. Since the light reflected by the reflective surface of the curved mirror is projected in a focus-free manner, a desired image with less distortion is displayed on the projection surface according to the present aspect.
In an aspect of the present example embodiment, the projection device includes a second shield instead of the first shield. The second shield is disposed on an optical path of the projection beam reflected by the reflective surface of the curved mirror. The second shield has a slit opened to allow the projection beam forming the desired image to pass therethrough, and shields an unnecessary light component included in the projection beam. In the present aspect, since the second shield is disposed at a stage after the curved mirror, there are few spatial restrictions due to the positions of the light source, the spatial light modulator, and the curved mirror. Therefore, according to the present aspect, the degree of freedom of the position where the second shield is disposed is high, and the entire device can be configured compactly.
In an aspect of the present example embodiment, the projection device includes a third shield instead of the first shield. The third shield is disposed behind the curved mirror. The third shield shields an unnecessary light component included in the modulated beam forming the desired image. In the present aspect, a component for shielding light is not disposed on the optical path of the modulated beam or the projection beam. Therefore, according to the present aspect, light utilization efficiency can be improved. In addition, according to the present modification, since there are few restrictions on spatial positional relationships between the light source, the spatial light modulator, and the curved mirror resulting from the arrangement of the first shield, the entire device can be configured compactly.
In an aspect of the present example embodiment, the reflective surface of the curved mirror has a curvature in a plane parallel to a horizontal plane. According to the present aspect, a projection beam projected after being enlarged in the horizontal direction can be projected.
In an aspect of the present example embodiment, the reflective surface of the curved mirror has a curvature in a plane perpendicular to the horizontal plane. According to the present aspect, a projection beam projected after being enlarged in a direction perpendicular to the horizontal direction can be projected.
Next, a projection device according to a second example embodiment will be described with reference to the drawings. The projection device according to the present example embodiment includes a reflecting mirror (also referred to as a folding mirror) that reflects a modulated beam modulated by the modulation portion of the spatial light modulator in such a way as to fold the modulated beam toward the curved mirror.
The light source 21 has the same configuration as the light source 11 of the first example embodiment. The light source 21 includes an emitter 211 and a lens 212. The emitter 211 emits a laser beam 201 in a predetermined wavelength band according to the control of the control unit 27. The lens 212 enlarges the laser beam 201 emitted from the emitter 211 in accordance with a size of a modulation portion 230 of the spatial light modulator 23. The laser beam 201 emitted from the emitter 211 is enlarged by the lens 212 and emitted from the light source 21. A beam 202 emitted from the light source 21 travels toward the modulation portion 230 of the spatial light modulator 23.
The spatial light modulator 23 has the same configuration as the spatial light modulator 13 of the first example embodiment. The spatial light modulator 23 includes a modulation portion 230 irradiated with the beam 202. The modulation portion 230 of the spatial light modulator 23 is irradiated with the beam 202 emitted from the light source 21. In the modulation portion 230 of the spatial light modulator 23, a pattern according to an image to be displayed by a projection beam 205 is set according to the control of the control unit 27. The modulated beam 203 modulated by the modulation portion 230 of the spatial light modulator 23 travels toward a reflective surface 260 of the folding mirror 26.
The shield 24 has the same configuration as the shield 14 of the first example embodiment. The shield 24 is disposed between the spatial light modulator 23 and the folding mirror 26. In other words, the shield 24 is disposed on an optical path of the modulated beam 203 modulated by the modulation portion 230 of the spatial light modulator 23. The shield 24 is an aperture in which a slit-shaped opening is formed in a portion through which light forming a desired image passes. The shield 24 allows light forming a desired image to pass therethrough and shields an unnecessary light component. For example, the shield 24 shields 0th-order light or a ghost included in the modulated beam 203.
The folding mirror 26 is disposed on the optical path of the modulated beam 203. The folding mirror 26 has a planar reflective surface 260. In other words, the folding mirror 26 is a flat mirror. The reflective surface 260 of the folding mirror 26 is disposed toward the opening of the shield 24 and the reflective surface 250 of the curved mirror 25. The folding mirror 26 reflects the modulated beam 203 arriving through the opening of the shield 24 toward the reflective surface 250 of the curved mirror 25. The 0th-order light or the ghost image included in the modulated beam 203 is shielded by the shield 24 and does not reach the reflective surface 260 of the folding mirror 26. That is, the modulated beam 203 reflected by the reflective surface 260 of the folding mirror 26 is constituted by light components that form a desired image.
The curved mirror 25 has the same configuration as the curved mirror 15 of the first example embodiment. The curved mirror 25 is a reflecting mirror having a curved reflective surface 250. The reflective surface 250 of the curved mirror 25 has a curvature in accordance with a projection angle of a projection beam 205. In the example of
The curved mirror 25 is disposed on an optical path of light reflected by the reflective surface 260 of the folding mirror 26, with the reflective surface 250 facing the reflective surface 260 of the folding mirror 26. The reflective surface 250 of the curved mirror 25 is irradiated with a light component reflected by the reflective surface 260 of the folding mirror 26 out of the modulated beam 203 that has been modulated by the modulation portion 230 of the spatial light modulator 23 and has passed through the slit-shaped opening of the shield 24.
As described above, the projection device according to the present example embodiment includes a light source, a spatial light modulator, a shield, a folding mirror, and a curved mirror. The light source emits a beam. The spatial light modulator includes a modulation portion irradiated with the beam emitted from the light source. The spatial light modulator modulates a phase of the emitted beam in the modulation portion. The control unit sets a phase image for forming a desired image in the modulation portion of the spatial light modulator. The control unit controls the light source in such a way that the modulation portion, in which the phase image is set, is irradiated with the beam. The shield (also referred to as a first shield) is disposed between the spatial light modulator and the curved mirror. The first shield has a slit opened to allow the modulated beam forming the desired image to pass therethrough, and shields an unnecessary light component included in the modulated beam. The folding mirror reflects the optical path of the modulated beam modulated by the modulation portion of the spatial light modulator toward the reflective surface of the curved mirror. The curved mirror has a curved reflective surface irradiated with the modulated beam reflected by the reflective surface of the folding mirror. The curved mirror reflects the modulated beam on the reflective surface, and projects a projection beam having a projection angle enlarged according to a curvature of the reflective surface.
In the configuration of the present example embodiment, the optical path between the spatial light modulator and the curved mirror is folded using the folding mirror. Therefore, according to the configuration of the present example embodiment, it is not necessary to linearly set the optical path between the spatial light modulator and the curved mirror, making it possible to configure the size of the device compactly.
Next, a projection device according to a third example embodiment will be described with reference to the drawings. The projection device according to the present example embodiment is different from those in the first and second example embodiments in that modulated beams modulated by the modulation portion of the spatial light modulator are projected in two different directions.
The light source 31 has the same configuration as the light source 11 of the first example embodiment. The light source 31 includes an emitter 311 and a lens 312. The emitter 311 emits a laser beam 301 in a predetermined wavelength band under the control of control unit 37. The lens 312 enlarges the laser beam 301 emitted from the emitter 311 in accordance with a size of a modulation portion 330 of the spatial light modulator 33. The laser beam 301 emitted from the emitter 311 is enlarged by the lens 312 and emitted from the light source 31. A beam 302 emitted from the light source 31 travels toward the modulation portion 330 of the spatial light modulator 33.
The spatial light modulator 33 has the same configuration as the spatial light modulator 13 of the first example embodiment. The spatial light modulator 33 includes a modulation portion 330 irradiated with the beam 302. The modulation portion 330 of the spatial light modulator 33 is irradiated with the beam 302 emitted from the light source 31. In the modulation portion 330 of the spatial light modulator 33, a pattern according to an image to be displayed by a projection beam 305 is set according to the control of the control unit 37. A modulated beam 303 modulated by the modulation portion 330 of the spatial light modulator 33 travels toward a reflective surface 350A of the first curved mirror 35A and a reflective surface 360 of the folding mirror 36.
The first curved mirror 35A has the same configuration as the curved mirror 15 of the first example embodiment. The first curved mirror 35A is a reflecting mirror having a curved reflective surface 350A. The reflective surface 350A of the first curved mirror 35A has a curvature in accordance with a projection angle of a projection beam 305A. In the example of
The first curved mirror 35A is disposed on an optical path of the modulated beam 303, with the reflective surface 350A facing the modulation portion 330 of the spatial light modulator 33. A first optical path is formed between the light source 31, the modulation portion 330 of the spatial light modulator 33, and the reflective surface 350A of the first curved mirror 35A. The reflective surface 350A of the first curved mirror 35A is irradiated with the modulated beam 303 modulated by the modulation portion 330 of the spatial light modulator 33. The light (the projection beam 305A) reflected by reflective surface 350A of the first curved mirror 35A is projected in a first direction (the left direction of the paper surface of
The folding mirror 36 is disposed on an optical path of the modulated beam 303 with the reflective surface 360 facing the modulation portion 330 of the spatial light modulator 33. The folding mirror 36 has a planar reflective surface 360. In other words, the folding mirror 36 is a flat mirror. The reflective surface 360 of the folding mirror 36 is disposed toward the modulation portion 330 of the spatial light modulator 33 and a reflective surface 350B of the second curved mirror 35B. The reflective surface 360 of the folding mirror 36 is irradiated with a light component emitted toward the reflective surface of the folding mirror 36 out of the modulated beam 303 modulated by the modulation portion 330 of the spatial light modulator 33. A light component emitted toward the first curved mirror 35A out of the modulated beam 303 does not reach the reflective surface 360 of the folding mirror 36. The modulated beam 303 reflected by the reflective surface 360 of the folding mirror 36 is constituted by a light component to be reflected by the reflective surface 350B of the second curved mirror 35B and projected as a projection beam 305B in a second direction (the right direction of the paper surface of
The second curved mirror 35B is disposed on an optical path of light reflected by the reflective surface 360 of the folding mirror 36, with the reflective surface 350B facing the reflective surface 360 of the folding mirror 36. A second optical path is formed between the light source 31, the modulation portion 330 of the spatial light modulator 33, the reflective surface 360 of the folding mirror 36, and the reflective surface 350B of the second curved mirror 35B. The first optical path and the second optical path are preferably set to have the same optical path length. The reflective surface 350B of the second curved mirror 35B is irradiated with a light component reflected by the reflective surface 360 of the folding mirror 36 out of the modulated beam 303 modulated by the modulation portion 330 of the spatial light modulator 33.
In the example of
As described above, the projection device according to the present example embodiment includes a light source, a spatial light modulator, a shield, a folding mirror, and a curved mirror. The light source emits a beam. The spatial light modulator includes a modulation portion irradiated with the beam emitted from the light source. The spatial light modulator modulates a phase of the emitted beam in the modulation portion. The control unit sets a phase image for forming a desired image in the modulation portion of the spatial light modulator. The control unit controls the light source in such a way that the modulation portion, in which the phase image is set, is irradiated with the beam. The shield (also referred to as a first shield) is disposed between the spatial light modulator and the curved mirror. The first shield has a slit opened to allow the modulated beam forming the desired image to pass therethrough, and shields an unnecessary light component included in the modulated beam. The curved mirror includes a first curved mirror and a second curved mirror. The first curved mirror has a curved first reflective surface irradiated with a part of the modulated beam modulated by the modulation portion of the spatial light modulator. The first curved mirror reflects the modulated beam on the first reflective surface, and projects a first projection beam having a projection angle enlarged according to a curvature of the first reflective surface. The folding mirror reflects a light component that is not reflected by the first reflective surface of the first curved mirror, out of the modulated beam modulated by the modulation portion of the spatial light modulator, toward the second reflective surface of the second curved mirror. The second curved mirror has a curved second reflective surface irradiated with a light component reflected by the folding mirror out of the modulated beam modulated by the modulation portion of the spatial light modulator. The second curved mirror reflects the light component on the second reflective surface, and projects a second projection beam having a projection angle enlarged according to a curvature of the second reflective surface. The first curved mirror and the second curved mirror are disposed in such a way that the first projection beam and the second projection beam are projected in different directions. For example, the first curved mirror and the second curved mirror are disposed in such a way that the first projection beam and the second projection beam are projected in opposite directions.
In the configuration of the present example embodiment, the projection beam reflected by the reflective surface of the first curved mirror is projected in the first direction. The projection beam reflected by the reflective surface of the second curved mirror is projected in the second direction. Therefore, according to the configuration of the present example embodiment, the projection angles can be expanded to opposing projection directions while having a compact configuration. For example, in the configuration of the present example embodiment, if the projection angle of each of the first curved mirror and the second curved mirror is set to 180 degrees, the projection beam can be projected in a direction of 360 degrees.
Next, a projection device according to a fourth example embodiment will be described with reference to the drawings. The projection device according to the present example embodiment includes a plurality of light sources. The configuration of the present example embodiment may be combined with those of the second and third example embodiments.
Each of the plurality of light sources 41 has the same configuration as the light source 11 of the first example embodiment.
The emitters 411-1 to 411-3 emit laser beams 401-1 to 401-3 in a predetermined wavelength band under the control of the control unit 47. The emitters 411-1 to 411-3 may be configured to emit laser beams 401-1 to 401-3 in the same wavelength band, or may be configured to emit laser beams 401-1 to 401-3 in different wavelength bands. Further, the emitters 411-1 to 411-3 may be configured to emit laser beams 401-1 to 401-3 having the same output, or may be configured to emit laser beams 401-1 to 401-3 having different outputs. The wavelength bands and outputs of the laser beams 401-1 to 401-3 emitted from the emitters 411-1 to 411-3 may be selected according to the application.
The lenses 412-1 to 412-3 enlarge the laser beams 401-1 to 401-3 emitted from the emitters 411-1 to 411-3 according to sizes of regions set for the laser beams 401-1 to 401-3, respectively, in the modulation portion 430 of the spatial light modulator 43. The laser beams 401-1 to 401-3 emitted from the emitters 411-1 to 411-3 are enlarged by the lenses 412-1 to 412-3 and emitted from the light sources 41-1 to 41-3. Beams 402-1 to 402-3 emitted from the light sources 41-1 to 41-3 travel toward the modulation portion 430 of the spatial light modulator 43.
The spatial light modulator 43 has the same configuration as the spatial light modulator 13 of the first example embodiment. The spatial light modulator 43 includes a modulation portion 430 irradiated with the beams 402-1 to 402-3. The modulation portion 430 is divided into a plurality of regions each allocated for one of the beams 402-1 to 402-3. Each of the plurality of regions of the modulation portion 430 of the spatial light modulator 43 is irradiated with an allocated beam 402 among the beams 402-1 to 402-3 emitted from the light sources 41-1 to 41-3. In the modulation portion 430 of the spatial light modulator 43, a pattern according to an image to be displayed by a projection beam 406 is set to a region for each of the beams 402-1 to 402-3 under the control of the control unit 47.
The shield 44 has the same configuration as the shield 14 of the first example embodiment. The shield 44 is disposed between the spatial light modulator 43 and the curved mirror 45. In other words, the shield 44 is disposed on an optical path of a modulated beam 403 modulated by the modulation portion 430 of the spatial light modulator 43. The shield 44 is an aperture in which a slit-shaped opening is formed in a portion through which light forming a desired image passes. The shield 44 allows light forming a desired image to pass therethrough and shields an unnecessary light component. For example, the shield 44 shields 0th-order light or a ghost included in the modulated beam 403.
The curved mirror 45 has the same configuration as the curved mirror 15 of the first example embodiment. The curved mirror 45 is a reflecting mirror having a curved reflective surface 450. The reflective surface 450 of the curved mirror 45 has a curvature in accordance with a projection angle of a projection beam 405. In the example of
The curved mirror 45 is disposed on an optical path of the modulated beam 403 modulated by the modulation portion 430 of the spatial light modulator 43, with the reflective surface 450 facing the spatial light modulator 43. The reflective surface 450 of the curved mirror 45 is irradiated with the modulated beam 403 that has been modulated by the modulation portion 430 of the spatial light modulator 43 and has passed through the slit-shaped opening of the shield 44.
As described above, a projection device according to the present example embodiment includes a light source, a spatial light modulator, a shield, and a curved mirror. The light source includes a plurality of emitters and a plurality of lenses that enlarge beams emitted by the plurality of emitters, respectively, in accordance with a size of the modulation portion of the spatial light modulator. The spatial light modulator includes a modulation portion irradiated with the beam emitted from the light source. The spatial light modulator modulates a phase of the emitted beam in the modulation portion. The control unit sets a phase image for forming a desired image in the modulation portion of the spatial light modulator. The control unit controls the light source in such a way that the modulation portion, in which the phase image is set, is irradiated with the beam. The shield (also referred to as a first shield) is disposed between the spatial light modulator and the curved mirror. The first shield has a slit opened to allow the modulated beam forming the desired image to pass therethrough, and shields an unnecessary light component included in the modulated beam. The curved mirror has a curved reflective surface irradiated with the modulated beam modulated by the modulation portion of the spatial light modulator. The curved mirror reflects the modulated beam on the reflective surface, and projects a projection beam having a projection angle enlarged according to a curvature of the reflective surface.
The projection device according to the present example embodiment includes a plurality of light sources. Therefore, according to the present example embodiment, desired images can be simultaneously projected toward different projection targets. For example, according to the present example embodiment, projection beams of a plurality of wavelength bands and spatial light signals directed to a plurality of communication targets can be simultaneously projected. For example, according to the present example embodiment, it is possible to simultaneously project a spatial light signal for scanning a communication target and a spatial light signal for communicating with a communication target with which communication has been established.
Next, a communication device according to a fifth example embodiment will be described with reference to the drawings. The communication device according to the present example embodiment includes the projection device according to any one of the first to fourth example embodiments and a projection device that projects a spatial light signal. Hereinafter, an example of a communication device including a projection device including a phase modulation-type spatial light modulator will be described. Note that the communication device according to the present example embodiment may include a projection device having a light transmission function rather than the phase modulation-type spatial light modulator.
The projection device 510 is the projection device according to any one of the first to fourth example embodiments. The projection device 510 acquires a control signal from the control device 550. The projection device 510 projects a spatial light signal according to the control signal. The spatial light signal projected from the projection device 510 is received by a communication target (not illustrated).
The control device 550 acquires a signal output from the reception device 570. The control device 550 executes processing according to the acquired signal. The processing executed by the control device 550 is not particularly limited. The control device 550 outputs a control signal for projecting a light signal according to the executed processing to the projection device 510.
The reception device 570 receives a spatial light signal projected from a communication target (not illustrated). The reception device 570 converts the received spatial light signal into an electrical signal. The reception device 570 outputs the converted electric signal to the control device 550.
Next, an example of a detailed configuration of the reception device will be described with reference to the drawings.
The ball lens 571 is a spherical lens. The ball lens 571 is an optical element that condenses a spatial light signal arriving from the outside. The ball lens 571 is spherical when viewed at any angle. The ball lens 571 condenses a spatial light signal incident thereon. Light (also referred to as a light signal) derived from the spatial light signal condensed by the ball lens 571 is condensed toward a condensing region. Since the ball lens 571 has a spherical shape, the ball lens 571 condenses a spatial light signal arriving from any direction. That is, the ball lens 571 exhibits similar light condensing performances for spatial light signals arriving from any directions.
For example, the ball lens 571 can be made of a material such as glass, crystal, or resin. In a case where a spatial light signal in the visible region is received, the material such as glass, crystal, or resin that transmits/refracts light in the visible region can be applied to the ball lens 571. For example, optical glass such as crown glass or flint glass can be applied to the ball lens 571. For example, crown glass such as Boron Kron (BK) can be applied to the ball lens 571. For example, flint glass such as Lanthanum Schwerflint (LaSF) can be applied to the ball lens 571. For example, quartz glass can be applied to the ball lens 571. For example, crystal such as sapphire can be applied to the ball lens 571. For example, transparent resin such as acryl can be applied to the ball lens 571. In a case where the spatial light signal is light in a near-infrared region (hereinafter also referred to as near-infrared light), a material capable of transmitting near-infrared light is used for the ball lens 571. For example, in a case where a spatial light signal in a near-infrared region of about 1.5 micrometers (μm), a material such as silicon can be applied to the ball lens 571 in addition to glass, crystal, resin, or the like. In a case where the spatial light signal is light in an infrared region (hereinafter also referred to as infrared light), a material capable of transmitting infrared light is used for the ball lens 571. For example, in a case where the spatial light signal is infrared light, a silicon, germanium, or chalcogenide material can be applied to the ball lens 571. The material of the ball lens 571 is not limited as long as it is capable of transmitting/refracting light in the wavelength region of the spatial light signal. The material of the ball lens 571 may be selected according to the required refractive index and application.
The light receiving element array 573 includes a plurality of light receiving elements arranged in an arc shape along the circumferential direction of the ball lens 571. The number of light receiving elements constituting the light receiving element array 573 is not limited. The light receiving element array 573 is disposed at a stage after the ball lens 571. Each of the plurality of light receiving elements includes a light receiving portion that receives a light signal derived from a spatial light signal to be received. Each of the plurality of light receiving elements is disposed in such a way that the light receiving portion faces an emission surface of the ball lens 571. Each of the plurality of light receiving elements is disposed in such a way that the light receiving portion is located in the condensing region of the ball lens 571. The light signal condensed by the ball lens 571 is received by the light receiving portion of the light receiving element located in the condensing region.
The light receiving element receives light in a wavelength region of the spatial light signal to be received. For example, the light receiving element is sensitive to light in the visible region. For example, the light receiving element is sensitive to light in the infrared region. The light receiving element is sensitive to light having a wavelength, for example, in the 1.5 μm (micrometer) band. Note that the wavelength band of the light to which the light receiving element is sensitive is not limited to the 1.5 μm band. The wavelength band of light received by the light receiving element can be set in accordance with a wavelength of a spatial light signal projected from a projection device (not illustrated). The wavelength band of the light received by the light receiving element may be set to, for example, a 0.8 μm band, a 1.55 μm band, or a 2.2 μm band. Alternatively, the wavelength band of the light received by the light receiving element may be, for example, a 0.8 to 1 μm band. The shorter the wavelength band, the smaller the absorption by moisture in the atmosphere, which is advantageous for optical spatial communication during rainfall. In addition, if saturated with intense sunlight, the light receiving element is not capable of reading a light signal derived from a spatial light signal. Therefore, a color filter that selectively passes light in the wavelength band of the spatial light signal may be installed at a stage before the light receiving element.
For example, the light receiving element can be achieved by an element such as a photodiode or a phototransistor. For example, the light receiving element is achieved by an avalanche photodiode. The light receiving element achieved by the avalanche photodiode is capable of supporting high-speed communication. Note that the light receiving element may be achieved by an element other than the photodiode, the phototransistor, or the avalanche photodiode as long as it is capable of converting a light signal into an electric signal. In order to improve the communication speed, the light receiving portion of the light receiving element is preferably as small as possible. For example, the light receiving portion of the light receiving element has a square light receiving surface having a side of about 5 millimeters (mm). For example, the light receiving portion of the light receiving element has a circular light receiving surface having a diameter of about 0.1 to 0.3 mm. The size and shape of the light receiving portion of the light receiving element may be selected according to the wavelength band of the spatial light signal, the communication speed, and the like.
The light receiving element converts the received light signal into an electric signal. The light receiving element outputs the converted electric signal to the reception circuit 575. Although only one line (path) is illustrated between the light receiving element array 573 and the reception circuit 575 in
The reception circuit 575 acquires a signal output from each of the plurality of light receiving elements. The reception circuit 575 amplifies the signal from each of the plurality of light receiving elements. The reception circuit 575 decodes the amplified signal and analyzes the signal from the communication target. For example, the reception circuit 575 collectively analyzes signals for the plurality of light receiving elements. In a case where signals are analyzed collectively for the plurality of light receiving elements, it is possible to achieve a single-channel reception device 570 that communicates with a single communication target. For example, the reception circuit 575 individually analyzes a signal for each of the plurality of light receiving elements. In a case where a signal is individually analyzed for each of a plurality of light receiving elements, it is possible to realize the multi-channel reception device 570 that communicates with a plurality of communication targets simultaneously. The signal decoded by the reception circuit 575 is used for any purpose. The use of the signal decoded by the reception circuit 575 is not particularly limited.
The reception device 570 according to the present example embodiment receives a light signal condensed by the ball lens 571 through a plurality of reception elements. The ball lens 571 uniformly condenses a spatial light signal arriving from any direction on the surrounding condensing region. Therefore, according to the present example embodiment, a light signal arriving from various directions can be uniformly received with a simple configuration.
For example, the reception device 570 has a configuration in which a plurality of reception elements are arranged in an annular shape in the condensing region of the ball lens 571. The ball lens 571 condenses a light signal arriving from a certain direction substantially parallel to the plane including the ring formed by the plurality of light receiving elements on the condensing region. Since the plurality of reception elements are annularly arranged in the condensing region of the ball lens 571, it is possible to receive a spatial light signal arriving from any direction. That is, if a plurality of reception elements are arranged in an annular shape in the condensing region of the ball lens 571, it is possible to receive a spatial light signal arriving from a direction of 360 degrees. For example, the projection device 30 according to the second example embodiment configured to project a projection beam in a direction of 360 degrees and the reception device 570 including the light receiving element array 573 constituted by a plurality of reception elements arranged in an annular shape are combined together. With such a configuration, it is possible to achieve a communication device that projects a spatial light signal in a direction of 360 degrees and receives a spatial light signal arriving from a direction of 360 degrees.
Next, an example in which the communication device 500 according to the present example embodiment is applied will be described with reference to the drawings.
There are few obstacles at the tops of poles such as utility poles or street lamps. Therefore, the tops of poles such as utility poles or street lamps are suitable for installing the communication device 500. In addition, if the communication devices 500 are installed at the same height the tops of poles, an arrival direction of a spatial light signal is limited to the horizontal direction, so that the light receiving area of the light receiving element array 573 constituting the light receiver 57 can be reduced and the device can be simplified. The pair of communication devices 500 that communicate with each other are arranged in such a way that at least one communication device 500 receives a spatial light signal projected from any of the communication devices 500. The pair of communication devices 500 may be arranged to transmit and receive spatial light signals to and from each other. In a case where a communication network for spatial light signals is configured by the plurality of communication devices 500, the communication device 500 positioned in the middle may be disposed to relay a spatial light signal projected from another communication device 500 to another communication device 500.
The first curved mirror 55A is disposed on an optical path of a modulated beam 503, with a reflective surface 550A facing a modulation portion 530 of the spatial light modulator 53. The reflective surface 550A of the first curved mirror 55A is irradiated with the modulated beam 503 modulated near the center of the modulation portion 530 of the spatial light modulator 53. The modulated beam 503 modulated in a peripheral portion of the modulation portion 530 of the spatial light modulator 53 travels to a region deviated from the reflective surface 550A of the first curved mirror 55A. Light (a projection beam 505A) reflected by the reflective surface 550A of the first curved mirror 55A is projected after being enlarged at an enlargement ratio according to a curvature of the reflective surface 550A. In the example of
Similarly, the second curved mirror 55B is disposed on an optical path of the modulated beam 503, with a reflective surface 550B facing the modulation portion 530 of the spatial light modulator 53. The reflective surface 550B of the second curved mirror 55B is irradiated with the modulated beam 503 modulated near the center of the modulation portion 530 of the spatial light modulator 53. The modulated beam 503 modulated in the peripheral portion of the modulation portion 530 of the spatial light modulator 53 travels to a region deviated from the reflective surface 550B of the second curved mirror 55B. Light (a projection beam 505B) reflected by the reflective surface 550B of the second curved mirror 55B is projected after being enlarged at an enlargement ratio according to a curvature of reflective surface 550B. In the example of
According to the present application example, the plurality of communication devices 500 installed on different poles can communicate with each other using spatial light signals. For example, communication may be performed in a wireless manner between a wireless device installed in an automobile, a house, or the like or a base station and a communication device 500 according to communication between the communication devices 500 installed on the different poles. For example, the communication device 500 may be configured to be connected to the Internet via the pole.
As described above, the communication device according to the present example embodiment includes the projection device according to any one of the first to fourth example embodiments, a reception device, and a projection device. The reception device receives a light signal transmitted from another communication device. The reception device decodes a signal based on the received light signal. The control device receives the signal decoded by the reception device. The control device executes processing according to the received signal. The control device transmits a light signal according to the executed processing to the projection device. According to the present example embodiment, it is possible to achieve a communication device that transmits and receives light signals.
Next, a projection device according to a sixth example embodiment will be described with reference to the drawings. The projection device according to the present example embodiment has a simplified configuration as compared with the projection devices according to the first to fourth example embodiments.
The light source 61 emits a beam. The spatial light modulator 63 includes a modulation portion 630 irradiated with a beam 602 emitted from the light source 61. The spatial light modulator 63 modulates a phase of the emitted beam 602 in the modulation portion 630. The control unit 67 sets a phase image for forming a desired image in the modulation portion 630 of the spatial light modulator 63. The control unit 67 controls the light source 61 in such a way that the modulation portion 630, in which the phase image is set, is irradiated with the beam 602. The curved mirror 65 has a curved reflective surface 650 irradiated with a modulated beam 603 modulated by the modulation portion 630 of the spatial light modulator 63. The curved mirror 65 reflects the modulated beam 603 on the reflective surface 650, and projects a projection beam 605 having a projection angle enlarged according to a curvature of the reflective surface 650.
As described above, the projection device according to the present example embodiment can project a desired image while having a structure in which a projection optical system such as a projection lens is omitted. That is, the projection device according to the present example embodiment is capable of projecting spatial light forming a desired image with a simple configuration.
Here, a hardware configuration for executing the control or processing according to each of the above-described example embodiments of the present disclosure will be described using an information processing device 90 of
As illustrated in
The processor 91 develops a program stored in the auxiliary storage device 93 or the like in the main storage device 92. The processor 91 executes the program developed in the main storage device 92. In the present example embodiment, a software program installed in the information processing device 90 may be used. The processor 91 executes the control or processing according to each of the above-described example embodiments.
The main storage device 92 has an area in which a program is developed. A program stored in the auxiliary storage device 93 or the like is developed in the main storage device 92 by the processor 91. The main storage device 92 is achieved by, for example, a volatile memory such as a dynamic random access memory (DRAM). In addition, a nonvolatile memory such as a magnetoresistive random access memory (MRAM) may be included/added as the main storage device 92.
The auxiliary storage device 93 stores various data such as programs. The auxiliary storage device 93 is achieved by a local disk such as a hard disk or a flash memory. Note that various data may be stored in the main storage device 92, and the auxiliary storage device 93 may be omitted.
The input/output interface 95 is an interface for connecting the information processing device 90 and a peripheral device to each other in accordance with a standard or a specification. The communication interface 96 is an interface for connection to an external system or device through a network such as the Internet or an intranet in accordance with a standard or a specification. The input/output interface 95 and the communication interface 96 may be shared as an interface connected to an external device.
An input device such as a keyboard, a mouse, or a touch panel may be connected to the information processing device 90 if necessary. These input devices are used to input information and settings. In a case where the touch panel is used as an input device, a display screen of a display device may also serve as an interface of the input device. Data communication between the processor 91 and the input device may be mediated by the input/output interface 95.
Furthermore, the information processing device 90 may include a display device for displaying information. In a case where the information processing device 90 includes a display device, the information processing device 90 preferably includes a display control device (not illustrated) for controlling the display of the display device. The display device may be connected to the information processing device 90 via the input/output interface 95.
Furthermore, the information processing device 90 may be equipped with a drive device. Between the processor 91 and the recording medium (program recording medium), the drive device mediates reading of data or a program from the recording medium, writing of a processing result of the information processing device 90 to the recording medium, and the like. The drive device only needs to be connected to the information processing device 90 via the input/output interface 95.
An example of the hardware configuration for enabling the control or processing according to each of the above-described example embodiments of the present disclosure has been described above. Note that the hardware configuration of
The components of the above-described example embodiments may be combined in any manner. In addition, the components according to each of the above-described example embodiments may be achieved by software or by a circuit.
While the invention has been particularly shown and described with reference to exemplary embodiments thereof, the invention is not limited to these embodiments. It will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the claims.
Some or all of the above-described example embodiments may be described as in the following supplementary notes, but are not limited to the following supplementary notes.
A projection device including:
The projection device according to supplementary note 1, in which the control unit sets, in the modulation portion of the spatial light modulator, a composite image obtained by combining a virtual lens image for condensing the modulated beam forming the desired image on the reflective surface of the curved mirror with the phase image for forming the desired image.
The projection device according to supplementary note 1 or 2, further including a first shield disposed between the spatial light modulator and the curved mirror, and having a slit opened to allow the modulated beam forming the desired image to pass therethrough, the first shield shielding an unnecessary light component included in the modulated beam.
The projection device according to supplementary note 1 or 2, further including a second shield disposed on an optical path of the projection beam reflected by the reflective surface of the curved mirror, and having a slit opened to allow the projection beam forming the desired image to pass therethrough, the second shield shielding an unnecessary light component included in the projection beam.
The projection device according to supplementary note 1 or 2, further including a third shield disposed behind the curved mirror, the third shield shielding an unnecessary light component included in the modulated beam forming the desired image.
The projection device according to any one of supplementary notes 1 to 5, in which a condensing point for the beam emitted by the light source is set behind the curved mirror.
The projection device according to any one of supplementary notes 1 to 5, further including a 0th-order light remover that removes 0th-order light included in the modulated beam modulated by the modulation portion of the spatial light modulator, in which
The projection device according to any one of supplementary notes 1 to 7, in which the reflective surface of the curved mirror has a curvature in a plane parallel to a horizontal plane.
The projection device according to any one of supplementary notes 1 to 8, in which the reflective surface of the curved mirror has a curvature in a plane perpendicular to a horizontal plane.
The projection device according to any one of claims 1 to 9, further including a folding mirror that reflects an optical path of the modulated beam modulated by the modulation portion of the spatial light modulator toward the reflective surface of the curved mirror.
The projection device according to supplementary note 10, in which
The projection device according to supplementary note 11, in which the first curved mirror and the second curved mirror are disposed in such a way that the first projection beam and the second projection beam are projected in opposite directions.
The projection device according to any one of supplementary notes 1 to 12, in which the light source includes:
(Supplementary Note 14)
A communication device including:
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2021/031473 | 8/27/2021 | WO |
