Light irradiation device

Abstract

The present invention provides a light irradiation system and a light irradiation device that transmit information between multiple light irradiation devices by irradiating an object with an irradiation beam. [Solution] The light irradiation device 1 comprises an imaging optical system 10, an optical member 20 that emits light incident through the imaging optical system toward the image plane of the imaging optical system and also emits an irradiation beam from a light generator incident through a conjugate plane conjugate to the image plane toward the imaging optical system, an imaging device 30 that images at least a part of the image of an object formed on the image plane by the imaging optical system, a position changing device 40 that changes the position of the irradiation beam emitted from the imaging optical system by changing the position of the irradiation beam from the light generator conjugate plane, and a control device 50 that controls the position changing device based on the imaging results of the imaging device, the control device controls the position changing device based on the imaging results of the imaging device to irradiate at least a part of the object with the irradiation beam emitted from the imaging optical system.

Description

Technical Field

[0001] The present invention relates to a light irradiation device.

Background Art

[0002] An optical communication method using laser light is known. For example, Patent Document 1 describes an optical communication device.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

[0004] The light irradiation device of the present invention is a light irradiation device that irradiates an object with an irradiation beam from a light generation device, and includes an imaging optical system, and an optical member that emits the light incident through the imaging optical system toward the image plane of the imaging optical system, and at the same time emits the irradiation beam from the light generation device incident through a conjugate plane conjugate to the image plane toward the imaging optical system, an imaging device that images at least a part of the image of the object formed on the image plane by the imaging optical system, a position changing device that changes the position of the irradiation beam from the light generation device on the conjugate plane to change the irradiation position of the irradiation beam emitted from the imaging optical system, and a control device that controls the position changing device based on the imaging result of the imaging device. The control device controls the position changing device based on the imaging result of the imaging device so that the irradiation beam emitted from the imaging optical system irradiates at least a part of the object.

Brief Description of the Drawings

[0005] [Figure 1] It is a schematic configuration diagram showing a light irradiation system according to the first embodiment. [Figure 2] It is a schematic configuration diagram schematically showing a light irradiation device according to the first embodiment. [Figure 3]This is a diagram illustrating the configuration around the light transmitting and receiving optical element according to the first embodiment. [Figure 4] This figure shows a first example of optical wireless communication according to the first embodiment. [Figure 5] This figure shows a second example of optical wireless communication according to the first embodiment. [Figure 6] This figure shows a third example of optical wireless communication according to the first embodiment. [Figure 7] This is a schematic diagram showing a modified example of the light irradiation system according to the first embodiment. [Figure 8] This is a schematic diagram illustrating a light irradiation device according to the second embodiment. [Figure 9] This is a schematic diagram illustrating a light irradiation device according to the third embodiment. [Figure 10] This is a schematic diagram illustrating the light irradiation device according to the fourth embodiment. [Figure 11] This is a schematic diagram illustrating the case in which the light reflection region according to the fourth embodiment is divided into light receiving and light transmitting regions. [Figure 12] This is a schematic diagram illustrating the case where the light transmitting and receiving optical element according to the fourth embodiment is placed in a defocus position. [Figure 13] This is a schematic diagram illustrating a light irradiation device according to the fifth embodiment. [Figure 14] This is a schematic diagram illustrating the light irradiation device according to the sixth embodiment. [Figure 15] This figure shows an example of a mobile body according to the sixth embodiment. [Figure 16] This is a schematic diagram illustrating the light irradiation device according to the seventh embodiment. [Figure 17] This is a schematic diagram illustrating the light irradiation device according to the eighth embodiment. [Figure 18] This is a schematic diagram illustrating the light irradiation device according to the ninth embodiment. [Modes for carrying out the invention]

[0006] Hereinafter, an optical irradiation device and an optical wireless communication system according to embodiments of the present invention will be described with reference to the drawings. Furthermore, the scope of the present invention is not limited to the following embodiments and can be arbitrarily modified within the scope of the technical idea of ​​the present invention. In addition, in the following drawings, the scale and numbers of each structure may differ from those of the actual structure in order to make each structure easier to understand.

[0007] [First Embodiment] Figure 1 is a schematic diagram showing a light irradiation system according to the first embodiment. The light irradiation system 100 will be described with reference to this figure. As shown in Figure 1, the light irradiation system 100 comprises a plurality of light irradiation devices 1 that irradiate an object with an irradiation beam 51. The irradiation beam 51 is an electromagnetic wave, for example, light. The irradiation beam 51 broadly includes light such as ultraviolet rays, infrared rays, visible light, and terahertz waves (terahertz light). In the first embodiment, the irradiation beam 51 is light modulated based on information. That is, the light irradiation device 1 transmits information by irradiating with light.

[0008] The object that the light irradiation device 1 irradiates with the irradiation beam 51 may be a part of the object that the light irradiation device 1 irradiates with the irradiation beam 51, or it may be the entire object that the light irradiation device 1 irradiates with the irradiation beam 51. In the first embodiment, the object may be, for example, another light irradiation device 1 different from itself. The light irradiation device 1 performs optical wireless communication by irradiating another light irradiation device 1 different from itself with the irradiation beam 51. The light irradiation system 100 includes a plurality of light irradiation devices 1, and performs optical wireless communication between the plurality of light irradiation devices 1.

[0009] The light irradiation device 1 may be installed on a movable body. The movable body may be, for example, any robot such as a vertically articulated robot, a gimbal, a manned / unmanned vehicle, a manned / unmanned aircraft, a manned / unmanned ship, a manned / unmanned submarine, etc. Here, the unmanned aircraft may also be referred to as a drone. The light irradiation device 1 may be installed on the surface of the outside or inside of the movable body. Here, the movable body includes those whose position can be changed or whose position relative to its own device can change. For example, in the case of a robot, even if the base part is fixed, the position of the end effector side part can change, so it may be referred to as a movable body. Here, the movable body may also be referred to as a moving body.

[0010] Also, the light irradiation device 1 may be fixedly installed on the surface of any object such as the surface of an artificial structure such as land or a building. The land includes the seabed, the lake bottom, etc., regardless of the terrain such as a flat surface or a slope. The artificial structure such as a building includes civil engineering structures. The surface of the artificial structure includes the floor, wall, ceiling of the building, and the outer surface of the building. The building is not limited to those traded as real estate, but also includes those traded as personal property. Also, the fixation is not limited to the case of being continuously fixed, but also includes the case of being temporarily fixed.

[0011] In an example shown in FIG. 1, the light irradiation system 100 includes, as the light irradiation device 1, a light irradiation device 1-1 and a light irradiation device 1-2. The light irradiation device 1-1 transmits information by emitting an irradiation beam 51 to the light irradiation device 1-2, and the light irradiation device 1-2 receives information by receiving the irradiation beam 51 emitted from the light irradiation device 1-1. Similarly, the light irradiation device 1-2 transmits information by emitting an irradiation beam 51 to the light irradiation device 1-1, and the light irradiation device 1-1 receives information by receiving the irradiation beam 51 emitted from the light irradiation device 1-2. Here, the object may be at least a part of the device that is the communication partner. For example, for the light irradiation device 1-1, at least a part of the light irradiation device 1-2 may be the object, and for the light irradiation device 1-2, at least a part of the light irradiation device 1-1 may be the object.

[0012] FIG. 2 is a schematic configuration diagram schematically showing a light irradiation device according to the first embodiment. While referring to this figure, the functional configuration of the light irradiation device 1 will be described. In some cases, an xyz three-dimensional orthogonal coordinate system using the x-axis, y-axis, and z-axis will be used for the description. As shown in FIG. 2, the light irradiation device 1 includes an imaging optical system 10, an optical member 20, an imaging device 30, a position changing device 40, a control device 50, and a light generation device 60. Note that the light irradiation device 1 may not include the light generation device 60, and the light irradiation device 1 and the light generation device 60 may be separate entities. When representing the light irradiation device 1 as an example of the above-described light irradiation device 1-1, it may be referred to as the light irradiation device 1A. Further, when representing the above-described imaging optical system 10, optical member 20, imaging device 30, position changing device 40, control device 50, and light generation device 60 as the configuration of the light irradiation device 1A, each of them may be referred to as an imaging optical system 10A, an optical member 20A, an imaging device 30A, a position changing device 40A, a control device 50A, and a light generation device 60A. Similarly, when representing the light irradiation device 1 as an example of the above-described light irradiation device 1-2, it may be referred to as the light irradiation device 1B. When representing the imaging optical system 10, optical member 20, imaging device 30, position changing device 40, control device 50, and light generation device 60 as the configuration of the light irradiation device 1B, each of them may be referred to as an imaging optical system 10B, an optical member 20B, an imaging device 30B, a position changing device 40B, a control device 50B, and a light generation device 60B. In the xyz three-dimensional orthogonal coordinate system, the x-axis indicates the direction of the optical axis 111 of the imaging optical system 10, and the plane formed by the y-axis and the z-axis indicates a plane orthogonal to the optical axis 111 of the imaging optical system 10.

[0013] Taking the case where the light irradiation device 1A and the light irradiation device 1B perform optical wireless communication as an example, each configuration of the light irradiation device 1 will be described. For example, the light irradiation device 1A irradiates (transmits) the light irradiation device 1B as an object with light for optical wireless communication as an irradiation beam 51. Further, the light irradiation device 1A receives (receives) the light for optical wireless communication (irradiation beam 51) emitted from the light irradiation device 1B. The light generator 60A generates light (irradiation beam 51) to irradiate the light irradiation device 1B. The light (irradiation beam 51) generated by the light generator 60A is emitted toward the light irradiation device 1B via the optical component 20A and the imaging optical system 10A. Details of the optical component 20 and the imaging optical system 10 will be described later. The light generator 60A also receives the light (irradiation beam) emitted from the light irradiation device 1B via the imaging optical system 10A and the optical component 20A.

[0014] The light generator 60 includes, as an example, a communication board 62, an optical fiber 61, and a transmitting / receiving optical element 41 which includes at least a portion of the optical fiber 61. The transmitting / receiving optical element 41 may also be referred to as a transmitting / receiving optical component. Furthermore, when the above-mentioned communication board 62, optical fiber 61, and transmitting / receiving optical element 41 are represented as components of the light generator 60A, they may be referred to as the communication board 62A, optical fiber 61A, and transmitting / receiving optical element 41A, respectively. Similarly, when the above-mentioned communication board 62, optical fiber 61, and transmitting / receiving optical element 41 are represented as components of the light generator 60B, they may be referred to as the communication board 62B, optical fiber 61B, and transmitting / receiving optical element 41B, respectively.

[0015] The communication board 62 converts one of the following into electrical signals for information communication and the other into light (irradiation beam 51) for optical wireless communication. For example, the communication board 62 generates light (irradiation beam 51) for optical wireless communication with the light irradiation device 1B. The communication board 62A generates light (irradiation beam 51) for optical wireless communication by converting electrical signals for information communication into light (irradiation beam 51). Also, for example, the communication board 62A receives the irradiation beam 51 emitted from the light irradiation device 1B. The communication board 62A converts the irradiation beam 51 from the light irradiation device 1B into electrical signals. Note that the communication board 62 may also be called an optical communication board.

[0016] The optical fiber 61 transmits light (irradiation beam 51) for optical wireless communication between the communication board 62 and the transmitting / receiving optical element 41. For example, the optical fiber 61A transmits light (irradiation beam 51) generated in the communication board 62A from the communication board 62A to the transmitting / receiving optical element 41A. Alternatively, for example, the optical fiber 61A transmits light (irradiation beam 51) received by the transmitting / receiving optical element 41A from the light irradiation device 1B via the imaging optical system 10A and optical member 20A to the communication board 62A.

[0017] The transmitting and receiving optical element 41 emits light (irradiation beam 51) incident via the optical fiber 61 toward the optical member 20. The transmitting and receiving optical element 41 also emits light (irradiation beam 51) incident via the imaging optical system 10 and the optical member 20 toward the optical fiber 61. For example, the transmitting and receiving optical element 41 includes at least an emission end of the optical fiber 61 that emits light (irradiation beam 51) from the communication substrate 62.

[0018] For example, the light transmitting and receiving optical element 41A emits light (irradiation beam 51) incident from the communication substrate 62A via the optical fiber 61A toward the optical member 20. The light transmitting and receiving optical element 41A emits light (irradiation beam 51) incident from the light irradiation device 1B via the imaging optical system 10A and the optical member 20A toward the optical fiber 61A. Furthermore, the light transmitting and receiving optical element 41 is positioned at or near the conjugate surface 220, which is a surface optically conjugate to the image plane 210 of the imaging optical system 10, which will be described later. For example, as shown in Figure 2, the light emission end 223 of the light transmitting and receiving optical element 41 on the optical member 20 side is positioned slightly away from the conjugate surface 220 in the direction away from the optical member 20. Furthermore, the light-emitting end 223 on the optical member 20 side of the light-transmitting / receiving optical element 41 may be positioned on the conjugate plane 220 of the imaging optical system 10, or it may be positioned slightly closer to the optical member 20 than the conjugate plane 220.

[0019] For example, the light transmitting and receiving optical element 41 emits light (irradiation beam 51) from the optical fiber 61 toward the optical member 20 via the conjugate surface 220 of the imaging optical system 10, and also emits light (irradiation beam 51) that has been incident via the conjugate surface 220 through the imaging optical system 10 and the optical member 20 toward the optical fiber 61. For example, the light transmitting and receiving optical element 41 is configured to receive light (irradiation beam 51) that is incident via the same optical path as the light (irradiation beam 51) emitted from the imaging optical system 10, from the light transmitting and receiving optical element 41 through the conjugate surface 220 and the optical member 20 until it is emitted from the imaging optical system 10, even when stationary. Alternatively, the light transmitting and receiving optical element 41 may be configured to receive light (irradiation beam 51) that is incident via a different optical path than the light (irradiation beam 51) emitted from the imaging optical system 10, from the light transmitting and receiving optical element 41 through the conjugate surface 220 and the optical member 20 until it is emitted from the imaging optical system 10. The light transmitting and receiving optical element 41 may consist of at least one optical component. The configuration of the light transmitting and receiving optical element 41 will be described later.

[0020] Furthermore, the light transmitting and receiving optical element 41 may be called a light emission unit or light emission device because it emits light (irradiation beam 51) to the optical member 20. Also, the light transmitting and receiving optical element 41 may be called a light receiving unit or light receiving device because it receives light (irradiation beam 51) from the optical member 20. Furthermore, the light transmitting and receiving optical element 41 may be called a light transmitting and receiving unit or light transmitting and receiving device because it emits light (irradiation beam 51) to the optical member 20 and receives light (irradiation beam 51) from the optical member 20.

[0021] Furthermore, the term "light emission unit" or "light emission device" is not limited to the light transmitting / receiving optical element 41, but also includes at least one of the communication substrate 62, optical fiber 61, optical member 20, and imaging optical system 10. In other words, the light irradiation device 1 can be said to include a light emission unit or light emission device that emits the irradiation beam 51. Furthermore, the light generator 60 may also be referred to as a light emission unit or light emission device. Furthermore, the light irradiation device 1 may also be referred to as a light emission unit or light emission device.

[0022] Furthermore, the term "light receiving unit" or "light receiving device" is not limited to the light transmitting and receiving optical element 41, but also includes at least one of the imaging optical system 10, optical member 20, optical fiber 61, and communication substrate 62. In other words, the light irradiation device 1 can also be said to include a light receiving unit or light receiving device that receives the irradiation beam 51. Furthermore, the light generating device 60 may also be referred to as a light receiving unit or light receiving device. Furthermore, the light generating device 60 may also be referred to as a light receiving unit or light receiving device. Furthermore, the light irradiation device 1 may also be referred to as a light receiving unit or light receiving device.

[0023] Furthermore, the term "transmitting / receiving unit" or "transmitting / receiving device" is not limited to the transmitting / receiving optical element 41; at least one of the imaging optical system 10, optical member 20, optical fiber 61, and communication substrate 62 may also be referred to as the transmitting / receiving unit or light transmitting / receiving device. In other words, the light irradiation device 1 can also be said to include a transmitting / receiving unit or light transmitting / receiving device that emits an irradiation beam 51 and receives the irradiation beam 51. Furthermore, the light generating device 60 may also be referred to as the transmitting / receiving unit, light transmitting / receiving device, photoelectric conversion unit, or photoelectric conversion device. Furthermore, the light irradiation device 1 may also be referred to as the transmitting / receiving unit or light transmitting / receiving device.

[0024] Furthermore, the light irradiation device 1 does not necessarily have to include at least one of the communication board 62, optical fiber 61, and transmitting / receiving optical element 41 from the light generator 60, and the light irradiation device 1 and at least one of the communication board 62, optical fiber 61, and transmitting / receiving optical element 41 may be separate entities.

[0025] The imaging optical system 10 forms a reduced image of at least a portion of the object on the image plane 210. In this embodiment, where the light illumination system 100 performs optical wireless communication, the object may be, as described above, the device that is the communication partner, i.e., at least a portion of the light illumination device 1. The imaging optical system 10 may form a reduced image of at least a portion of the light illumination device 1 of the other party performing optical wireless communication on the image plane 210. The imaging optical system 10 may also emit light (illumination beam 51) for optical wireless communication emitted from the optical member 20 via the transmitting and receiving optical element 41 toward the other party's light illumination device 1. The imaging optical system 10 may also receive the illumination beam 51 from the other party's light illumination device 1 and emit it toward the optical member 20. For example, the imaging optical system 10A may form a reduced image of at least a portion of the light illumination device 1B on the image plane 210. Furthermore, the imaging optical system 10A may emit light (irradiation beam 51) for optical wireless communication emitted from the optical member 20A via the light transmitting and receiving optical element 41A toward the light irradiation device 1B. Alternatively, the imaging optical system 10A may receive the irradiation beam 51 from the light irradiation device 1B and emit it toward the optical member 20A.

[0026] An imaging device 30 is positioned near the image plane 210 of the imaging optical system 10. The imaging device 30 captures a reduced image of at least a portion of an object formed on the image plane 210. The imaging device 30 includes an image sensor 31 having a plurality of pixels arranged on its imaging surface. It can also be said that the image sensor 31 captures a reduced image of at least a portion of an object formed on the image plane 210. For example, the imaging surface of the image sensor 31 may be positioned on the image plane 210 of the imaging optical system 10. Alternatively, the imaging surface of the image sensor 31 may not be positioned on the image plane 210 of the imaging optical system 10, but may be positioned near the image plane 210. The image sensor 31 may be an image sensor capable of outputting color image data (e.g., an RGB image sensor) or an image sensor capable of outputting monochrome image data (e.g., a monochrome image sensor).

[0027] Furthermore, the imaging optical system 10 does not necessarily have to form a reduced image of at least a portion of the object on the image plane 210. For example, the imaging optical system 10 may be configured to form an enlarged image or a life-size image of at least a portion of the object on the image plane 210.

[0028] The field of view of the imaging optical system 10 is preferably wide-angle; for example, the maximum field of view of the imaging optical system 10 is preferably 170° or more. However, the maximum field of view on the object side of the imaging optical system 10 may be less than 170°, for example, 60°. Furthermore, the field of view of the imaging optical system 10 may be approximately 180°. If the imaging optical system 10 has a field of view of approximately 180°, an omnidirectional camera can be configured by arranging two light illumination devices 1 in directions 180° apart, facing opposite directions from each other.

[0029] The imaging optical system 10 may be telecentric on the conjugate plane 220 side. To make the imaging optical system 10 telecentric on the conjugate plane 220 side, for example, an aperture diaphragm (not shown) may be provided at a predetermined position. This aperture diaphragm does not have to be provided in the imaging optical system 10. Alternatively, the imaging optical system 10 may be made telecentric on the conjugate plane 220 side by limiting the effective diameter of a predetermined lens to a predetermined size.

[0030] Furthermore, the imaging optical system 10 may be non-telecentric on the object side. To make the imaging optical system 10 non-telecentric on the object side, for example, an aperture diaphragm (not shown) may be provided at a predetermined position. This aperture diaphragm does not have to be provided in the imaging optical system 10. Alternatively, the imaging optical system 10 may be made non-telecentric on the object side by limiting the effective diameter of a predetermined lens to a predetermined size. Furthermore, the imaging optical system 10 may include a plurality of optical components. The plurality of optical components included in the imaging optical system 10 may include well-known optical components. For example, the imaging optical system 10 may include a plurality of lens components, or it may include at least one lens component and at least one reflective component.

[0031] The optical element 20 is positioned on the image plane 210 side of the imaging optical system 10 and divides the optical path of the imaging optical system 10. Here, the imaging optical system 10 forms an image plane 210 and a conjugate plane 220 in each of the optical paths divided by the optical element 20. When the image plane 210 formed by the imaging optical system 10 is called the first image plane, the conjugate plane 220 may be called the second image plane formed by the imaging optical system 10. It can also be said that the optical element 20 divides the optical path of the imaging optical system 10 into the optical path on the image plane 210 side of the imaging optical system 10 (from the perspective of the object, the optical path from the optical element 20 to the image plane 210) and the optical path on the conjugate plane 220 side of the imaging optical system 10 (from the perspective of the object, the optical path from the optical element 20 to the conjugate plane 220). The optical component 20 emits light from the imaging optical system 10 along the optical path on the image plane 210 side, for example, to form a reduced image of at least a part of an object on the image plane 210. The optical component 20 also receives light for optical wireless communication (irradiation beam 51) emitted from the light transmitting / receiving optical element 41 along the optical path on the conjugate plane 220 side, and emits it towards the imaging optical system 10. Here, for example, the light transmitting / receiving optical element 41 is positioned near the conjugate plane 220. In other words, the optical component 20 can also be said to emit light (irradiation beam 51) from the light transmitting / receiving optical element 41 (i.e., the light generator 60) that is incident via the conjugate plane 220 toward the imaging optical system 10. Furthermore, even if the light emission end 223 of the light transmitting / receiving optical element 41 is positioned on the conjugate surface 220, or if the light emission end 223 is positioned slightly closer to the optical member 20 than the conjugate surface 220, the optical member 20 is considered to emit light (irradiation beam 51) from the light transmitting / receiving optical element 41 (i.e., the light generator 60) that is incident via the conjugate surface 220 toward the imaging optical system 10. In addition, the optical member 20 emits light (irradiation beam 51) for optical wireless communication that is incident via the imaging optical system 10 along the optical path on the conjugate surface 220 side ( toward the light transmitting / receiving optical element 41).

[0032] The optical element 20 may be, for example, a half-mirror. In this case, the optical element 20 transmits approximately 50% of the light from the imaging optical system 10 to form a reduced image of at least a portion of the object on the image plane 210, and emits it along the optical path on the image plane 210 side. The optical element 20 also reflects approximately 50% of the light for optical wireless communication (irradiation beam 51) emitted from the transmitting / receiving optical element 41 along the optical path on the conjugate plane 220 side, and emits it towards the imaging optical system 10. It also reflects approximately 50% of the light for optical wireless communication (irradiation beam 51) incident through the imaging optical system 10, and emits it along the optical path on the conjugate plane 220 side (towards the transmitting / receiving optical element 41).

[0033] Furthermore, the optical element 20 is not limited to a half mirror. The optical element 20 may be a reflective material with a reflectivity other than 50%. Also, the optical element 20 may be a dichroic mirror. In this case, the wavelengths of the light may be determined such that the light for optical wireless communication (irradiation beam 51) is reflected by the dichroic mirror, and the light from the imaging optical system 10 for forming a reduced image of at least a part of the object on the image plane 210 is transmitted. Also, the optical element 20 may be a polarizing beam splitter. Furthermore, the optical element 20 may be called a beam splitter because it divides the optical path.

[0034] Furthermore, the conjugate plane 220 is located on the opposite side of the imaging optical system 10 from the object side (the image plane 210 side) and is conjugate to the image plane 210. That is, in the imaging optical system 10, the image plane 210 and the conjugate plane 220 are conjugate. Furthermore, the image plane 210 may be referred to as the first conjugate plane, and the conjugate plane 220 as the second conjugate plane. Furthermore, the negative x-axis side of the imaging optical system 10 may be described as the object side, and the positive x-axis side may be described as the image plane 210 side or the conjugate plane 220 side.

[0035] In this embodiment, the x-axis side of the optical member 20 is described as the image plane 210 and the y-axis side of the optical member 20 as the conjugate plane 220. However, the image plane 210 and the conjugate plane 220 may be reversed. That is, the y-axis side of the optical member 20 may be the image plane 210 and the x-axis side of the optical member 20 may be the conjugate plane 220.

[0036] The position changing device 40 changes the irradiation position of the illumination beam 51 emitted from the imaging optical system 10. Specifically, the position changing device 40 may include a drive unit for changing the position of the illumination beam 51 from the light generator 60 on the conjugate plane 220. The position changing device 40 may also be a drive unit for changing the position of the illumination beam 51 from the light generator 60 on the conjugate plane 220. The position changing device 40 changes the irradiation position of the illumination beam 51 emitted from the imaging optical system 10 by changing the position of the illumination beam 51 from the light generator 60 on the conjugate plane 220. When the position of the illumination beam 51 from the light generator 60 on the conjugate plane 220 changes, the position at which the illumination beam 51 is incident on the imaging optical system 10 via the optical member 20 changes. As the incident position of the illumination beam 51 from the optical member 20 to the imaging optical system 10 changes, the irradiation position of the illumination beam 51 emitted from the imaging optical system 10 changes. Furthermore, the position changing device 40 can also be said to change the irradiation direction of the irradiation beam 51 emitted from the imaging optical system 10 by changing the position of the irradiation beam 51 from the light generator 60 on the conjugate plane 220.

[0037] The position changing device 40 may be a drive device that moves the light transmitting / receiving optical element 41 and at least one of the optical member 20, the imaging optical system 10, and the imaging device 30. The position changing device 40 may be a drive device that moves the light transmitting / receiving optical element 41 relative to the optical member 20, the imaging optical system 10, and the imaging device 30. In this case, the position changing device 40 may be a well-known drive device such as a linear motor or a stepping motor that can move the light transmitting / receiving optical element 41. Furthermore, the position changing device 40 may be a drive device that moves the optical member 20, the imaging optical system 10, and the imaging device 30 relative to the light transmitting / receiving optical element 41.

[0038] For example, the repositioning device 40 may move the light transmitting / receiving optical element 41 in a direction intersecting the optical axis 111 of the imaging optical system 10 (for example, in the direction of arrow 410 shown in Figure 2, or in the x-axis or z-axis direction). For example, if the imaging optical system 10 is configured as image-side telecentric, the repositioning device 40 can also be described as moving the light transmitting / receiving optical element 41 in a direction intersecting the optical axis 111 on the light transmitting / receiving optical element 41 side of the imaging optical system 10. "Moving the light transmitting / receiving optical element 41 in a direction intersecting the optical axis 111 of the imaging optical system 10" may also mean moving it in a direction perpendicular to the optical axis 411, or in a direction that intersects it at an angle other than a right angle. Furthermore, the repositioning device 40 can also be described as moving the light transmitting / receiving optical element 41 in a direction parallel to the conjugate plane 220. Here, the optical axis 111 of the imaging optical system 10, from the optical element 20 to the conjugate plane 220, may be referred to as optical axis 111a, and the optical axis 111b may be referred to from the optical element 20 to the image plane 210. Furthermore, optical axis 111a may be referred to as the optical axis on the conjugate plane 220 side of the imaging optical system 10. Also, optical axis 111b may be referred to as the optical axis on the image plane 210 side of the imaging optical system 10. In this case, the position changing device 40 can be said to move the transmitting / receiving optical element 41 in a direction intersecting the optical axis 111a. Alternatively, the position changing device 40 can be said to move the transmitting / receiving optical element 41 in a direction perpendicular to the optical axis 111a. Furthermore, the position changing device 40 can be said to change the position of the transmitting / receiving optical element 41 on the plane intersecting the optical axis 111a. Furthermore, the position changing device 40 can also be said to change the position of the light transmitting and receiving optical element 41 in a plane perpendicular to the optical axis 111a. The position changing device 40 may change the position of the irradiation beam 51 from the light generating device 60 (light transmitting and receiving optical element 41) on the conjugate plane 220 by moving the light transmitting and receiving optical element 41 as described above. Note that the position changing device 40 is not limited to the light transmitting and receiving optical element 41, but may also change the position of the irradiation beam 51 from the light generating device 60 on the conjugate plane 220 by moving the entire light generating device 60 as described above. Note that, as described above, the light transmitting and receiving optical element 41 can be considered as a light emission unit, so the optical axis 111a may be referred to as the optical axis on the light emission unit side of the imaging optical system 10. Also, as described above, the light transmitting and receiving optical element 41 can be considered as a light receiving unit, so the optical axis 111a may be referred to as the optical axis on the light receiving unit side of the imaging optical system 10.Furthermore, as mentioned above, since the light transmitting and receiving optical element 41 can be considered as a light transmitting and receiving unit, the optical axis 111a may also be referred to as the optical axis on the light transmitting and receiving unit side of the imaging optical system 10.

[0039] The position changing device 40 moves the irradiation position of the irradiation beam 51 in the direction of arrow 110, for example, by moving the transmitting and receiving photo-optical element 41 in the direction of arrow 410. Furthermore, the position changing device 40 changes the receiving position of the light (irradiation beam 51) for optical wireless communication emitted from the optical irradiation device 1 of the other party engaging in optical wireless communication. The receiving position may also be described as the position where the light (irradiation beam 51) from the optical irradiation device 1 of the other party engaging in optical wireless communication enters the imaging optical system 10. Alternatively, the receiving position may be described as the position of the transmitting / receiving optical element 41 in a direction perpendicular to the optical axis 111a. For example, the position changing device 40 changes the receiving position of the light (irradiation beam 51) for optical wireless communication by moving the transmitting / receiving optical element 41 in a direction intersecting the optical axis 111a as described above. When the position changing device 40 moves the transmitting / receiving optical element 41 in a direction intersecting the optical axis 111a, the optical path from the imaging optical system 10 to the transmitting / receiving optical element 41 changes. As a result of the change in the optical path from the imaging optical system 10 to the transmitting / receiving optical element 41, the receiving position of the light (irradiation beam 51) for optical wireless communication changes. Furthermore, the position changing device 40 may move the light transmitting and receiving optical element 41 in a direction perpendicular to the optical axis 111a. The position changing device 40 may also change the position of the light transmitting and receiving optical element 41 on a plane intersecting the optical axis 111a. Furthermore, the position changing device 40 may change the position of the light transmitting and receiving optical element 41 on a plane perpendicular to the optical axis 111a. The position changing device 40 may change the light receiving position of the light (irradiation beam 51) for optical wireless communication by moving the light transmitting and receiving optical element 41 as described above. Furthermore, the position changing device 40 may change the light receiving position of the light (irradiation beam 51) for optical wireless communication by moving the entire light generating device 60 as described above. Furthermore, it can be said that the position changing device 40 changes the light receiving direction of the light (irradiation beam 51) for optical wireless communication by moving the light transmitting and receiving optical element 41 as described above.

[0040] Furthermore, the position changing device 40 may move the optical member 20 relative to the light transmitting / receiving optical element 41 in a direction intersecting the optical axis 111a of the imaging optical system 10. Even in this case, the position changing device 40 can be said to change the position of the irradiation beam 51 from the light generator 60 on the conjugate plane 220. Furthermore, the position changing device 40 may move the optical member 20, the imaging optical system 10, and the imaging device 30 together relative to the light transmitting / receiving optical element 41 in a direction intersecting the optical axis 111a of the imaging optical system 10. Alternatively, the position changing device 40 may move the light transmitting / receiving optical element 41 and the optical member 20 individually in a direction intersecting the optical axis 111a of the imaging optical system 10. Even in this case, the position changing device 40 can be said to change the position of the irradiation beam 51 from the light generator 60 on the conjugate plane 220. The position changing device 40 may also move the optical member 20, the imaging optical system 10, and the imaging device 30 together in a direction intersecting the optical axis 111a of the imaging optical system 10.

[0041] The control device 50 controls the imaging device 30 so that it captures at least a portion of the image of the object. The control device 50 also controls the position change device 40 based on the imaging results of the imaging device 30. In other words, the control device 50 moves the transmitting and receiving photo-optical elements 41 by the position change device 40 based on the imaging results of the imaging device 30. Based on the position of at least a portion of the object in the image acquired by imaging by the imaging device 30, the control device 50 controls the position change device 40 so that the illumination beam 51 emitted from the imaging optical system 10 is incident on the imaging optical system 10 of the other party's optical illumination device 1 (that is, so that the illumination position of the illumination beam 51 is the imaging optical system 10 of the other party's optical illumination device 1).

[0042] Here, it is also possible to pre-associate the position of the phototransmitting / receiving optical element 41 in the direction intersecting the optical axis 111a (i.e., the position on the conjugate plane 220 of the irradiation beam 51) with the position on the image acquired by the imaging device 30. For example, the position of the phototransmitting / receiving optical element 41 in the direction intersecting the optical axis 111a with the position on the image acquired by the imaging device 30 can be associated with the position on the image acquired by the imaging device 30 by associating the position on the image on the image acquired by the imaging device 30 with the irradiation position of the irradiation beam 51. As described above, the irradiation position of the irradiation beam 51 is determined by the position on the conjugate plane 220 of the irradiation beam 51 from the light generator 60, that is, the position in the direction intersecting the optical axis 111a of the phototransmitting / receiving optical element 41. Therefore, by associating the position on the image acquired by the imaging device 30 with the irradiation position of the irradiation beam 51, it is possible to associate the position of the phototransmitting / receiving optical element 41 in the direction intersecting the optical axis 111a with the position on the image acquired by the imaging device 30. The method of mapping will be explained later.

[0043] By correlating the position of the transmitting / receiving optical element 41 in a direction intersecting the optical axis 111a with its position on the image acquired by the imaging device 30, the irradiation beam 51 can be directed more accurately to the target position of an object recognized on the image acquired by the imaging device 30. Therefore, the control device 50 can more accurately direct the irradiation beam 51 emitted from the imaging optical system 10 into the imaging optical system 10 of the optical irradiation device 1 of the other party communicating via optical wireless communication by controlling the position changing device 40 based on the position of at least a portion of the objects on the image acquired by the imaging device 30.

[0044] Furthermore, the position on the image acquired by the imaging device 30 may be referred to as the position on the imaging surface of the image sensor 31 of the imaging device 30, or as the pixel position of the image sensor 31. For example, the control device 50A may control the position change device 40A (or move the transmitting / receiving optical element 41A) so that the illumination beam 51 emitted from the imaging optical system 10A is incident on the imaging optical system 10B (i.e., the illumination position of the illumination beam 51 emitted from the imaging optical system 10A is the imaging optical system 10B) based on the position of at least a part of the light illumination device 1B as an object on the image acquired by imaging by the imaging device 30A.

[0045] The control device 50 may control the position changing device 40 based on the characteristic features of the object detected based on the imaging results captured by the imaging device 30. The characteristic features of the object may be at least a part of the object. The characteristic features of the object may be a marker placed on the optical illumination device 1 of the other party communicating via optical wireless communication, as an object. In this case, the positional relationship between the marker placed on the optical illumination device 1 of the other party communicating via optical wireless communication and the target position (for example, the imaging optical system 10 of the other party's optical illumination device 1) that is illuminated by the illumination beam 51 of the other party's optical illumination device 1 may be known.

[0046] Furthermore, the markers used to indicate the characteristic features of an object may be well-known markers such as one-dimensional barcodes, QR codes (registered trademarks), or AR markers provided on the optical irradiation device 1 of the party communicating via optical wireless communication. Furthermore, the markers, which represent characteristic points of an object, may be points illuminated by light-emitting parts such as LEDs provided in the light irradiation device 1 of the other party engaging in optical wireless communication, or they may be flashing patterns produced by the light-emitting parts. Note that the light-emitting parts are not limited to LEDs, but may be other existing light-emitting elements, or they may be light-emitting devices composed of multiple light-emitting elements. Furthermore, the flashing pattern produced by the light-emitting part may be a pattern based on a specific rule, such as Morse code. Furthermore, the flashing pattern of the light-emitting unit may change depending on the position of the light-emitting unit in the direction intersecting the optical axis 111a of the transmitting / receiving optical element 41 in the other light irradiation device 1 on which the light-emitting unit is provided. For example, the flashing period and at least one of the light intensity when lit may be changed (i.e., the flashing pattern may be changed) depending on the change in the position of the transmitting / receiving optical element 41 in the other light irradiation device 1 on which the light-emitting unit is provided in the direction intersecting the optical axis 111a. Furthermore, a predetermined flashing pattern of the light-emitting unit (for example, at least one of a predetermined flashing period and a predetermined light intensity) may be referred to as the state of the marker. A change in the flashing pattern of the light-emitting unit may also be referred to as a change in the state of the marker.

[0047] Furthermore, the marker as a characteristic feature of an object may be a marker displayed on a display unit provided on the optical irradiation device 1 of the other party engaging in optical wireless communication. The marker displayed on the display unit may be a well-known marker such as a one-dimensional barcode, QR code (registered trademark), or AR marker. The marker displayed on the display unit may change depending on its position in the direction intersecting the optical axis 111a of the transmitting / receiving optical element 41 in the other party's optical irradiation device 1 where the display unit is provided. For example, the shape and color of the marker displayed on the display unit may be changed in accordance with the change in the position in the direction intersecting the optical axis 111a of the transmitting / receiving optical element 41 in the other party's optical irradiation device 1 where the display unit is provided (i.e., the marker displayed on the display unit may be changed). The display unit may be an existing display such as a liquid crystal display. The display state of the display unit (for example, at least one of the shape of a predetermined marker and the color of a predetermined marker) may be referred to as the marker state. A change in the display state of the display unit (for example, a change in at least one of the shape of a predetermined marker and the color of a predetermined marker) may be referred to as a change in the marker state. Furthermore, the markers representing the characteristic features of the object may be any well-known markers, as long as they are recognizable on the image acquired by the imaging device 30.

[0048] Furthermore, the characteristic feature of the object may be at least one of the edges, contours, and textures of at least a portion of the optical illumination device 1 of the other party communicating via optical wireless communication. In this case, the positional relationship between at least one of the edges, contours, and textures of at least a portion of the optical illumination device 1 of the other party communicating via optical wireless communication and the target position of the other party's optical illumination device 1 that is illuminated by the illumination beam 51 may be known.

[0049] Furthermore, the characteristic part of the object may be at least a part of the imaging optical system 10 of the optical illumination device 1 of the other party engaging in optical wireless communication. In this case, at least a part of the imaging optical system 10 may be at least a part of the optical element closest to the object among the plurality of optical elements constituting the imaging optical system 10 (that is, at least a part of the optical element located furthest from the imaging device 30 among the plurality of optical elements constituting the imaging optical system 10). Furthermore, the characteristic part of the object may be at least a part of the protective member covering the object side of the imaging optical system 10 of the optical irradiation device 1 of the other party engaging in optical wireless communication. Furthermore, the protective member covering the object side of the imaging optical system 10 can be considered as part of the imaging optical system 10. This protective member may be a light-transmitting member that transmits light (irradiation beam 51) for conducting optical wireless communication.

[0050] The control device 50 may identify the positions of at least some of the objects in the image acquired by the imaging device 30 by image processing using methods such as template matching, active search, mean shift, and particle filtering. The control device 50 may identify the positions of at least some of the objects in the image acquired by the imaging device 30 by image processing using machine learning such as deep learning. In this case, an inference unit (which may also be called an inference model) may be generated in advance using machine learning, which outputs the positions of at least some of the objects to be identified in the image when the acquired image is input. The control device 50 may input the image acquired by the imaging device 30 into an inference unit and determine the position of at least a portion of the object on the image by obtaining the position of at least a portion of the object on the image output from the inference unit. The position of at least a portion of the object on the image acquired by the imaging device 30, which is identified by the control device 50 through the image processing described above, may also be the position of a characteristic part of the object on the image.

[0051] The control device 50 moves the transmitting and receiving optical elements 41 so that the illumination beam 51 emitted from the imaging optical system 10 is incident on the optical illumination device 1 of the other party communicating via optical wireless communication, based on the position of the identified feature area in the image. The transmitting and receiving optical elements 41 transmit light (illumination beam 51) at the moved position, thereby irradiating the optical illumination device 1 of the other party communicating via optical wireless communication with the illumination beam 51.

[0052] For example, the image processing described above identifies the position of a marker on the other party's light irradiation device 1 on the image acquired by the imaging device 30. The control device 50 may control the position change device 40 (or move the transmitting / receiving photo-optical elements 41) so that the irradiation beam 51 emitted from the light irradiation device 1 is incident on the imaging optical system 10 of the other party's light irradiation device 1, which is the target to be irradiated with the irradiation beam 51, based on the position of the identified marker on the image and the positional relationship between the marker and the imaging optical system 10 of the other party's light irradiation device 1.

[0053] In this case, the position of the transmitting / receiving optical element 41 of the other party's light irradiation device 1 in a direction intersecting the optical axis 111a may be predetermined so that the irradiation beam 51 incident on a specific position in the imaging optical system 10 of the other party's light irradiation device 1 is incident on the transmitting / receiving optical element 41 of the other party's light irradiation device 1. Here, the light incident on a specific position in the imaging optical system 10 of the light irradiation device 1 travels along a specific optical path and is incident on a specific position on the conjugate plane 220 via the optical member 20. In other words, the incident position of light on the conjugate plane 220 is determined by the incident position of light on the imaging optical system 10 of the light irradiation device 1. Therefore, if the transmitting / receiving optical element 41 is positioned so that the light incident on a specific position on the conjugate plane 220 is incident on the transmitting / receiving optical element 41, the light incident on a specific position in the imaging optical system 10 can be received by the transmitting / receiving optical element 41. The control device 50 may control the position change device 40 so that the irradiation beam 51 emitted from the light irradiation device 1 is incident on a specific position in the imaging optical system 10 of the other light irradiation device 1 (i.e., the transmitting and receiving photo-optical element 41 of the other light irradiation device 1), based on the position of the marker on the image provided on the other light irradiation device 1, the positional relationship between the imaging optical system 10 of the other light irradiation device 1 and the marker, and a specific position in the imaging optical system 10 of the other light irradiation device 1 into which the irradiation beam 51 is incident. The specific position in the imaging optical system 10 of the other light irradiation device 1 may be the center of the optical element closest to the object among the multiple optical elements constituting the imaging optical system 10, or it may be a position located a known distance away from the center.

[0054] Furthermore, the control device 50 may detect the state of the marker on the other light irradiator 1 based on the imaging results of the imaging device 30, and based on the detected state of the marker, it may determine the position of the transmitting / receiving optical element 41 in the other light irradiator 1 in a direction intersecting the optical axis 111a. If the position of the transmitting / receiving optical element 41 in the other light irradiator 1 in a direction intersecting the optical axis 111a can be determined, then the incidence position of the other light irradiator 1 into the imaging optical system 10 for injecting the irradiation beam 51 into the transmitting / receiving optical element 41 can be determined. Therefore, the control device 50 may control the position change device 40 so that the irradiation beam 51 emitted from the light irradiation device 1 is incident on the transmitting / receiving photo-optical element 41 of the other light irradiation device 1, based on the position of the marker of the other light irradiation device 1 on the image acquired by the imaging device 30, which is identified by the image processing described above, the positional relationship between the marker and the imaging optical system 10 of the other light irradiation device 1, and the incident position of the other light irradiation device 1 into the imaging optical system 10, which is identified based on the detected state of the marker. Furthermore, when detecting the blinking pattern of the light-emitting part as the state of the marker provided on the other party's light-emitting device 1 (for example, at least one of the blinking period and the light intensity when lit), the control device 50 may detect the blinking pattern of the light-emitting part based on a plurality of images acquired by the imaging device 30 at a predetermined frame rate (i.e., a plurality of images with different acquisition times). Furthermore, when detecting the display state of the display unit as the state of the marker (for example, at least one of the shape of the marker and the color of a predetermined marker), the control device 50 may detect the display state of the display unit based on images acquired by the imaging device 30.

[0055] For example, as described above, the control device 50A of the light irradiation device 1A may control the position change device 40A so that the irradiation beam 51 emitted from the light irradiation device 1A is incident on the imaging optical system 10B, based on the position of the marker of the light irradiation device 1B on the image acquired by the imaging device 30A, which has been identified by the image processing described above. Here, as described above, the positional relationship between the marker and the imaging optical system 10, which is the target to be irradiated with the irradiation beam 51, may be known. The control device 50A may control the position change device 40A so that the irradiation beam 51 emitted from the light irradiation device 1A is incident on the transmitting / receiving photo-optical element 41B (i.e., the communication substrate 62B) via the imaging optical system 10B, based on the position of the marker of the light irradiation device 1B on the image and the positional relationship between the marker and the imaging optical system 10B, which is the target to be irradiated with the irradiation beam 51. Furthermore, the control device 50B of the light irradiation device 1B may control the position change device 40B (move the phototransmitting / receiving photo-optical element 41B) so that the irradiation beam 51 from the light irradiation device 1A, which is incident on the imaging optical system 10B, is incident on the phototransmitting / receiving photo-optical element 41B. For example, the control device 50B may control the position change device 40B so that the irradiation beam 51 from the light irradiation device 1A, which is incident on the imaging optical system 10B, is incident on the phototransmitting / receiving photo-optical element 41B, based on the position of the marker of the light irradiation device 1A on the image acquired by the imaging device 30B, which is identified by the image processing described above. In this case, the control device 50B is not limited to irradiation with the irradiation beam 51 from the light irradiation device 1A, but may also irradiate the light irradiation beam 51 so that it is incident on the phototransmitting / receiving photo-optical element 41A of the light irradiation device 1A (i.e., the communication board 62A).

[0056] Furthermore, the control device 50B of the light irradiation device 1B may control the position change device 40B so that the irradiation beam 51 emitted from the light irradiation device 1B is incident on the imaging optical system 10A, based on the position of the marker of the light irradiation device 1A on the image acquired by the imaging device 30B, which is identified by the image processing described above. Here, as described above, the positional relationship between the marker and the imaging optical system 10A, which is the target to be irradiated with the irradiation beam 51, may be known. The control device 50B may control the position change device 40B so that the irradiation beam 51 emitted from the light irradiation device 1B is incident on the transmitting / receiving photo-optical element 41A (i.e., the communication substrate 62A) via the imaging optical system 10A, based on the position of the marker of the light irradiation device 1A on the image and the positional relationship between the marker and the imaging optical system 10A, which is the target to be irradiated with the irradiation beam 51. Furthermore, the control device 50A of the light irradiation device 1A may control the position change device 40A so that the irradiation beam 51 from the light irradiation device 1B, which is incident on the imaging optical system 10A, is incident on the transmitting and receiving photo-optical element 41A. For example, the control device 50A may control the position change device 40A so that the irradiation beam 51 from the light irradiation device 1B, which is incident on the imaging optical system 10A, is incident on the transmitting and receiving photo-optical element 41A, based on the position of the marker of the light irradiation device 1B on the image acquired by the imaging device 30A, which is identified by the image processing described above. In this case, the control device 50A is not limited to irradiation with the irradiation beam 51 from the light irradiation device 1B, but may also irradiate the irradiation beam 51 so that it is incident on the transmitting and receiving photo-optical element 41B (i.e., the communication board 62B) of the light irradiation device 1B.

[0057] Furthermore, when the irradiation beam 51 from the light irradiation device 1A is incident on the light transmitting / receiving optical element 41B via the imaging optical system 10B, and the light transmitting / receiving optical element 41A is stopped in a direction intersecting the optical axis 111a of the light irradiation device 1A, and the light transmitting / receiving optical element 41B is stopped in a direction intersecting the optical axis 111a of the light irradiation device 1B, the irradiation beam 51 from the light transmitting / receiving optical element 41B is emitted via the same optical path as the irradiation beam 51 from the light irradiation device 1A incident on the imaging optical system 10B, through the optical member 20B and the conjugate surface 220 until it is received by the light transmitting / receiving optical element 41B. Therefore, if the control device 50A controls the position change device 40A so that the irradiation beam 51 emitted from the light irradiation device 1A is incident on the transmitting / receiving photo-optical element 41B via the imaging optical system 10B, the control device 50B does not need to control the position change device 40B (that is, it does not need to move the transmitting / receiving photo-optical element 41B while the irradiation beam 51 from the light irradiation device 1A is incident on the transmitting / receiving photo-optical element 41B), and the irradiation beam 51 emitted from the light irradiation device 1B is incident on the transmitting / receiving photo-optical element 41A. Conversely, if the control device 50B controls the position change device 40B so that the irradiation beam 51 emitted from the light irradiation device 1B is incident on the transmitting / receiving photo-optical element 41A via the imaging optical system 10A, the control device 50A does not need to control the position change device 40A, and the irradiation beam 51 emitted from the light irradiation device 1A is incident on the transmitting / receiving photo-optical element 41B.

[0058] Furthermore, the control device 50B may determine the position of the transmitting / receiving optical element 41B into which the irradiation beam 51 from the light irradiation device 1A incident on the imaging optical system 10B is incident, without using the imaging results of the imaging device 30B. For example, the control device 50B may determine the position of the transmitting / receiving optical element 41B by controlling the position changing device 40B to move the transmitting / receiving optical element 41B and detecting the reception state of the irradiation beam 51 on the communication board 62B. In this case, the position of the transmitting / receiving optical element 41B in the direction intersecting the optical axis 111a of the light irradiation device 1B may be the position when the control device 50B detects that the irradiation beam 51 from the light irradiation device 1A has been received on the communication board 62B. In this case, the control device 50B may irradiate the transmitting / receiving optical element 41A with the irradiation beam 51 while the transmitting / receiving optical element 41B is irradiated with the irradiation beam 51. Furthermore, the control device 50A may determine the position at which the irradiation beam 51 from the light irradiation device 1B, which is incident on the imaging optical system 10A, enters the transmitting / receiving optical element 41A, without using the imaging results of the imaging device 30A. For example, the control device 50A may determine the position of the transmitting / receiving optical element 41A by controlling the position changing device 40A to move the transmitting / receiving optical element 41A and detecting the reception state of the irradiation beam 51 on the communication board 62A. In this case, the position of the transmitting / receiving optical element 41A in the direction intersecting the optical axis 111a of the light irradiation device 1A may be the position at which the control device 50A detects that the irradiation beam 51 from the light irradiation device 1B has been received on the communication board 62A. In this case, the control device 50B may irradiate the transmitting / receiving optical element 41B with the irradiation beam 51 while the transmitting / receiving optical element 41A is irradiated with the irradiation beam 51.

[0059] Furthermore, as described above, the control device 50A may control the position change device 40A so that the irradiation beam 51 from the light irradiation device 1A is incident on a specific position in the imaging optical system 10B (i.e., the phototransmitting and receiving optical element 41B) when the position of the phototransmitting and receiving optical element 41B in a direction intersecting the optical axis 111a of the light irradiation device 1B is positioned at a specific position, so that the irradiation beam 51 incident on a specific position in the imaging optical system 10B of the light irradiation device 1B is incident on the phototransmitting and receiving optical element 41B. In this case, the control device 50A may control the position change device 40A so that the irradiation beam 51 emitted from the light irradiation device 1A is incident on a specific position in the imaging optical system 10B (i.e., the phototransmitting and receiving optical element 41B) based on the position of the marker provided on the light irradiation device 1B on the image, the positional relationship between the imaging optical system 10B and the marker, and a specific position in the imaging optical system 10B into which the irradiation beam 51 is incident. Furthermore, the control device 50B may control the position changing device 40B so that the transmitting and receiving photo-optical elements 41B are positioned at a specific location in a direction intersecting the optical axis 111a of the light irradiation device 1B. In this case, the control device 50B may also irradiate the irradiation beam 51. The irradiation beam 51 emitted from the light irradiation device 1B is incident on the transmitting and receiving photo-optical elements 41A of the light irradiation device 1A.

[0060] Similarly, the control device 50B may control the position changing device 40B so that the irradiation beam 51 from the light irradiation device 1B is incident on the specific position of the imaging optical system 10A, while the position of the light irradiation device 41A in a direction intersecting the optical axis 111a of the light irradiation device 1A is positioned at a specific position, so that the irradiation beam 51 incident on the specific position of the imaging optical system 10A is incident on the light transmitting and receiving photo-optical element 41A. In this case, the control device 50A may irradiate with the irradiation beam 51. The irradiation beam 51 emitted from the light irradiation device 1A is incident on the light transmitting and receiving photo-optical element 41B.

[0061] Furthermore, the control device 50A may determine the position of the transmitting / receiving photo-optical element 41B in the light irradiation device 1B in a direction intersecting the optical axis 111a, based on the blinking pattern of the light-emitting part, which is provided on the light irradiation device 1B as a marker, as detected by the image processing described above. For example, the control device 50A may control the position changing device 40A so that the irradiation beam 51 emitted from the light irradiation device 1A is incident on the transmitting / receiving photo-optical element 41B of the light irradiation device 1B, based on the position of the light-emitting part of the light irradiation device 1B on the image acquired by the imaging device 30A, which is determined by the image processing described above, the positional relationship between the imaging optical system 10B and the light-emitting part of the light irradiation device 1B, and the incident position on the imaging optical system 10B determined based on the detected blinking pattern of the light-emitting part. In this case, the control device 50B may irradiate with the irradiation beam 51. The irradiation beam 51 emitted from the light irradiation device 1B is incident on the transmitting / receiving photo-optical element 41A of the light irradiation device 1A. Furthermore, the relationship between the position of the light transmitting / receiving optical element 41B in the light irradiation device 1B in a direction intersecting the optical axis 111a and the position of the irradiation beam 51 into the imaging optical system 10B for injecting the light transmitting / receiving optical element 41B may be determined in advance.

[0062] Furthermore, the control device 50A may control the position change device 40A so that the illumination beam 51 emitted from the light illumination device 1A is incident on the transmitting / receiving optical element 41B, based on the position of at least one of the edges, contours, and textures of at least a portion of the light illumination device 1B on the image acquired by the imaging device 30A, which has been identified by the image processing described above. In this case, the control device 50A may control the position change device 40A so that the illumination beam 51 emitted from the light illumination device 1A is incident on the transmitting / receiving optical element 41B, based on the position of at least one of the edges, contours, and textures of at least a portion of the light illumination device 1B on the image acquired by the imaging device 30A, and the positional relationship between at least one of the edges, contours, and textures of at least a portion of the light illumination device 1B and the imaging optical system 10B.

[0063] At this time, the control device 50B may move the phototransmitting and receiving optical element 41B so that the irradiation beam 51 from the light irradiation device 1A that is incident on the imaging optical system 10B is incident on the phototransmitting and receiving optical element 41B. In this case, the control device 50B may control the position change device 40B so that the irradiation beam 51 from the light irradiation device 1A, which is incident on the imaging optical system 10B, is incident on the transmitting and receiving photo-optical element 41B, based on the position of at least one of the edges, contours, and textures of at least a portion of the light irradiation device 1A on the image acquired by the imaging device 30B, which is identified by the image processing described above. Furthermore, the control device 50B may irradiate with the irradiation beam 51 while the irradiation beam 51 from the light irradiation device 1A is incident on the transmitting and receiving photo-optical element 41B. The irradiation beam 51 emitted from the light irradiation device 1B is incident on the transmitting and receiving photo-optical element 41A. As described above, at least a portion of the objects in the image whose position is determined by the image processing of the control device 50 may be different from at least a portion of the objects irradiated by the light irradiation device 1.

[0064] Furthermore, the control device 50A may control the position change device 40A so that the irradiation beam 51 emitted from the light irradiation device 1A is incident on the imaging optical system 10B (the optical element closest to the object) based on the position of the optical element of the imaging optical system 10B closest to the object on the image acquired by the imaging device 30A, which has been identified by the image processing described above.At this time, the control device 50B may control the position change device 40B so that the irradiation beam 51 from the light irradiation device 1A that has been incident on the imaging optical system 10B is incident on the transmitting and receiving photo-optical element 41B.Furthermore, the control device 50B may irradiate with the irradiation beam 51 while the irradiation beam 51 from the light irradiation device 1A is incident on the transmitting and receiving photo-optical element 41B.The irradiation beam 51 emitted from the light irradiation device 1B is incident on the transmitting and receiving photo-optical element 41A. Furthermore, the control device 50 may, not limited to the position of feature locations of an object on the image acquired by the imaging device 30, identify at least one of the position and orientation of feature locations of an object in real space based on the brightness distribution of the image acquired by the imaging device 30 through the image processing described above, and control the position changing device 40 so that the illumination beam 51 emitted from the imaging optical system 10 is incident on the transmitting and receiving photo-optical elements 41 of the optical illumination device 1 of the other party communicating via optical wireless communication.

[0065] Here, we will explain the effects that the irradiation beam 51 receives from each element of the light irradiation device 1 during light transmission. First, the irradiation beam 51 is generated by the light generator 60. The irradiation beam 51 emitted from the transmitting / receiving photo-optical element 41 is incident on the optical member 20 from the conjugate surface 220. The optical member 20 changes the direction of the incident irradiation beam 51 (for example, if the optical member 20 is a half-mirror, it reflects the irradiation beam 51) and emits it towards the imaging optical system 10. The imaging optical system 10 emits the incident irradiation beam 51 towards the other light irradiation device 1, which is an example of an object.

[0066] Next, we will explain the effects that the irradiation beam 51 experiences when receiving light, as it is affected by each element of the light irradiation device 1. First, the illumination beam 51 emitted from the other party's light irradiation device 1, which is an example of an object, enters the imaging optical system 10. The imaging optical system 10 emits the incident illumination beam 51 toward the optical member 20. The optical member 20 changes the direction of the incident illumination beam 51 (for example, if the optical member 20 is a half mirror, it reflects the illumination beam 51) and emits it toward the transmitting / receiving optical element 41 via the conjugate surface 220. The illumination beam 51 that enters the transmitting / receiving optical element 41 is received by the communication substrate 62 via the optical fiber 61.

[0067] Next, we will explain the effects of each element of the light irradiation device 1 on the light that forms a reduced image of at least a part of the object on the image plane 210. Light is incident on the imaging optical system 10 to form a reduced image of at least a portion of the opposing light illuminator 1, which is an example of an object, on the image plane 210. The imaging optical system 10, via the optical member 20, causes a reduced image of at least a portion of the opposing light illuminator 1 (for example, the characteristic portion described above) to be formed on the image plane 210. The reduced image formed on the image plane 210 is captured by the imaging device 30.

[0068] In this embodiment, the optical element 20 is positioned on the light generator 60 side of the imaging optical system 10, but the position of the optical element 20 is not limited to this example. The optical element 20 may be positioned, for example, within the imaging optical system 10, in other words, between a plurality of optical elements (a plurality of optical elements different from the optical element 20) that constitute the imaging optical system 10. Specifically, the optical element 20 may be positioned between at least one optical element of the imaging optical system 10 that is positioned on the object side relative to the optical element 20, and at least one optical element of the imaging optical system 10 that is positioned on the image plane 210 side relative to the optical element 20.

[0069] The optical element 20 may emit light that has passed through at least a portion of the imaging optical system 10 toward the image plane of the imaging optical system 10. Furthermore, the optical element 20 may emit light incident on the optical element 20 via at least one optical element of the imaging optical system 10 that is positioned on the object side relative to the optical element 20 toward at least one optical element of the imaging optical system 10 that is positioned on the image plane 210 side relative to the optical element 20. The light emitted toward at least one optical element of the imaging optical system 10 that is positioned on the image plane 210 side relative to the optical element 20 may then be emitted toward the image plane 210. Therefore, it can also be said that the optical element 20 emits light that has passed through at least a portion of the imaging optical system 10 toward the image plane of the imaging optical system 10. In addition, the optical element 20 may emit light incident on the optical element 20 via at least one optical element of the imaging optical system 10 that is positioned on the object side relative to the optical element 20 toward the light generator 60 (transmitting and receiving optical element 41). Furthermore, the optical element 20 may emit the irradiation beam 51 from the light generator 60 toward at least a part of the imaging optical system 10. The optical element 20 may emit the irradiation beam 51 from the light generator 60 that has been incident on the optical element 20 toward at least one optical element of the imaging optical system 10 that is located on the object side relative to the optical element 20. The irradiation beam 51 emitted toward at least one optical element of the imaging optical system 10 that is located on the object side relative to the optical element 20 may then be emitted toward the object. Therefore, it can also be said that the optical element 20 emits the irradiation beam 51 from the light generator 60 toward at least a part of the imaging optical system 10. Note that the optical element 20 may be located on the object side of the imaging optical system 10. In this case, the imaging device 30 images at least a part of the image of the object formed on the image plane 210 by the imaging optical system 10. Furthermore, the position changing device 40 changes the incident position of the irradiation beam 51 from the light generator 60 onto the optical member 20, thereby changing the irradiation position of the irradiation beam 51 emitted from the imaging optical system 10. Based on the imaging results from the imaging device 30, the light irradiation device 1 irradiates at least a portion of the object with the irradiation beam 51 emitted from the imaging optical system 10.

[0070] Furthermore, the optical element 20 can be considered as part of the imaging optical system 10, since it may affect the state of image formation on the image plane 210. Furthermore, the optical element 20 can be considered as being included in the imaging optical system 10. Furthermore, in the light irradiation device 1, the optical element 20 can be considered as being provided in the imaging optical system 10. In this case, the light irradiation device 1 can be considered to be comprised of the imaging optical system 10, the imaging device 30, and the position changing device 40. The optical element 20 of the imaging optical system 10 may emit incident light toward the image plane 210. Furthermore, the optical element 20 may emit light incident through at least one optical element of the imaging optical system 10, which is located on the object side relative to the optical element 20, toward at least one optical element of the imaging optical system 10, which is located on the image plane 210 side relative to the optical element 20. Furthermore, light emitted towards at least one optical element of the imaging optical system 10, which is positioned on the image plane 210 side relative to the optical element 20, may be emitted toward the image plane 210. Therefore, it can be said that the optical element 20 of the imaging optical system 10 emits light incident on it toward the image plane 210. In addition, the optical element 20 may emit light incident on it via at least one optical element of the imaging optical system 10, which is positioned on the object side relative to the optical element 20, toward the light generator 60 (transmitting and receiving optical element 41). Furthermore, the optical element 20 of the imaging optical system 10 may emit the irradiation beam 51 from the light generator 60 toward the object. Here, the optical element 20 emits the irradiation beam 51 from the light generator 60, which is incident on the optical element 20, toward at least one optical element of the imaging optical system 10, which is positioned on the object side relative to the optical element 20. Furthermore, the illumination beam 51 emitted towards at least one optical element of the imaging optical system 10, which is positioned on the object side relative to the optical element 20, is emitted toward the object. Therefore, it can be said that the optical element 20 of the imaging optical system 10 emits the illumination beam 51 from the light generator 60 toward the object. Note that the position in which the optical element 20 is positioned is not limited to the position described above. The optical element 20 may be positioned closest to the image plane 210 in the imaging optical system 10. Even in this case, the optical element 20 can be considered as part of the imaging optical system 10.The imaging device 30 captures at least a portion of the image of an object formed on the image plane 210 by the imaging optical system 10. The position changing device 40 changes the incident position of the irradiation beam 51 from the light generator 60 into the imaging optical system 10, thereby changing the irradiation position of the irradiation beam 51 emitted from the imaging optical system 10.

[0071] Figure 3 is a diagram illustrating an example of the configuration of the light transmitting and receiving optical element according to the first embodiment. An example of the configuration of the light transmitting and receiving optical element 41 will be described with reference to this figure. The light transmitting and receiving optical element 41 includes at least a portion of the optical fiber 61, a Fresnel lens 42, and a collimating lens 46. The end of the optical fiber 61 is positioned near the Fresnel lens 42. For example, the transmitting and receiving optical element 41 may include the end of the optical fiber 61 positioned near the Fresnel lens 42. Alternatively, a diffractive optical element may be used instead of a Fresnel lens.

[0072] The light (irradiation beam 51) for optical wireless communication generated by the communication board 62 passes through the optical fiber 61 and is incident on the Fresnel lens 42. The irradiation beam 51 emitted from the Fresnel lens 42 is incident on the collimating lens 46. Here, the collimating lens 46 focuses the incident irradiation beam 51 onto the conjugate plane 220. The irradiation beam 51 emitted from the collimating lens 46, after being focused on the conjugate plane 220, diverges and is incident on the optical member 20. The optical member 20 emits the irradiation beam 51 that was incident on it via the conjugate plane 220 toward the imaging optical system 10. In addition, the irradiation beam 51 incident on the imaging optical system 10 from the optical irradiation device 1 of the other party communicating via optical wireless communication is focused on the conjugate plane 220 by the imaging optical system 10 and the optical member 20. The light (irradiation beam 51) that diverged via the conjugate plane 220 is collimated by the collimating lens 46 and is incident on the Fresnel lens 42. The light emitted from the Fresnel lens 42 (irradiation beam 51) is focused and incident on the optical fiber 61.

[0073] The optical fiber 61 includes, for example, an optical fiber 61-1 for transmitting light (irradiation beam 51) generated on the communication board 62 from the communication board 62 to the transmitting / receiving photo-optical element 41, and an optical fiber 61-2 for transmitting the irradiation beam 51 incident on the imaging optical system 10 from the optical irradiation device 1 of the other party engaging in optical wireless communication, from the transmitting / receiving photo-optical element 41 to the communication board 62. The Fresnel lens 42 also includes, for example, a Fresnel lens 42-1 that collimates divergent light (irradiation beam 51) emitted from the end of the optical fiber 61-1 and emits it toward the collimating lens 46, and a Fresnel lens 42-2 that converges parallel light (irradiation beam 51) from the collimating lens 46 so that it is incident toward the end of the optical fiber 61-2.

[0074] With the above configuration, the transmitting and receiving optical element 41, while stationary, can receive light (irradiation beam 51) that is incident on it via the same optical path as the light (irradiation beam 51) emitted from the imaging optical system 10, passing through the conjugate plane 220 and the optical member 20 before being emitted from the imaging optical system 10. Therefore, as an example, in a state where the positional relationship with the other party's optical irradiation device 1 does not change, the optical irradiation device 1 can receive the irradiation beam 51 emitted from the other party's optical irradiation device 1 with the transmitting and receiving optical element 41 while simultaneously causing the irradiation beam 51 to be incident on the transmitting and receiving optical element 41 of the other party's optical irradiation device 1.

[0075] Furthermore, the position-changing device 40 may move the collimating lens 46, Fresnel lens 42-1, Fresnel lens 42-2, the end of optical fiber 61-1, and the end of optical fiber 61-2 as a single unit. In this case, the relative positions of the collimating lens 46, Fresnel lens 42-1, Fresnel lens 42-2, the end of optical fiber 61-1, and the end of optical fiber 61-2 may be fixed by a structure not shown.

[0076] Furthermore, at least one of the communication board 62, optical fiber 61-1, Fresnel lens 42-1, collimating lens 46, optical element 20, and imaging optical system 10 may be referred to as a light emission unit or light emission device that emits light (irradiation beam 51) via the imaging optical system 10. Also, at least one of the imaging optical system 10, optical element 20, collimating lens 46, Fresnel lens 42-2, optical fiber 61-2, and communication board 62 may be referred to as a light receiving unit or light receiving device that receives light (irradiation beam 51) incident from the optical irradiation device 1 of the other party engaging in optical wireless communication via the imaging optical system 10. Furthermore, the above-mentioned light receiving unit and light emission unit can be considered together as a light transmitting and receiving unit. Furthermore, the above-mentioned light receiving device and light emission device can be considered together as a light transmitting and receiving device.

[0077] Furthermore, the collimating lens 46 may be divided into a lens for focusing the light (irradiation beam 51) from the Fresnel lens 42-1 toward the conjugate surface 220, and a lens for collimating the divergent light (irradiation beam 51) from the conjugate surface 220 toward the Fresnel lens 42-2. In this case, at least a portion of the optical fiber 61-1 (for example, the end of the optical fiber 61-1 on the Fresnel lens 42-1 side), the Fresnel lens 42-1, and at least one of the lenses for focusing the light (irradiation beam 51) from the Fresnel lens 42-1 toward the conjugate surface 220 may be referred to as a light transmitting optical element or light transmitting optical system. Furthermore, the light transmitting optical element (light transmitting optical system) is not limited to the above configuration. The light transmitting optical element (light transmitting optical system) may be composed of at least one other existing optical element, as long as it can emit the light (irradiation beam 51) from the optical fiber 61-1 toward the optical element 20A. Furthermore, the lens for collimating the light (irradiation beam 51) emitted from the conjugate surface 220 toward the Fresnel lens 42-2, the Fresnel lens 42-2, and at least one of the optical fibers 61-2 (for example, the end of the optical fiber 61-2 on the Fresnel lens 42-2 side) may be referred to as a photodetecting optical element or a photodetecting optical system. Note that the photodetecting optical element (photodetecting optical system) is not limited to the above configuration. The photodetecting optical element (photodetecting optical system) may be composed of at least one other existing optical element, as long as it can emit light (irradiation beam 51) from the optical element 20A toward the optical fiber 61-2. Furthermore, at least one of the communication board 62, optical fiber 61-1, Fresnel lens 42-1, lens for focusing the light (irradiation beam 51) from Fresnel lens 42-1 toward the conjugate surface 220, optical element 20, and imaging optical system 10 may be referred to as a light emission unit or light emission device that emits light (irradiation beam 51) through the imaging optical system 10. In other words, the light transmitting optical element (light transmitting optical system) may be referred to as a light emission unit.Furthermore, at least one of the imaging optical system 10, the optical element 20, the lens for collimating the light (irradiation beam 51) emitted from the conjugate surface 220 toward the Fresnel lens 42-2, the Fresnel lens 42-2, the optical fiber 61-2, and the communication substrate 62 may be referred to as a light receiving unit or light receiving device that receives light (irradiation beam 51) incident from the optical irradiation device 1 of the other party engaging in optical wireless communication via the imaging optical system 10. In other words, the light receiving optical element (light receiving optical system) can be considered as a light receiving unit. Moreover, the above-mentioned light receiving unit (light receiving device) and the light emission unit (light emission device) may be considered together as a light transmitting and receiving unit (light transmitting and receiving device).

[0078] With the above configuration, the optical path of the light (irradiation beam 51) from the light transmitting optical element through the conjugate surface 220 and optical member 20 to the light emitted from the imaging optical system 10 is different from the optical path of the light (irradiation beam 51) from the imaging optical system 10 through the optical member 20 and conjugate surface 220 to the light receiving optical element. Therefore, the light transmitting and receiving optical element 41 can receive light (irradiation beam 51) that is incident via an optical path different from the optical path from the light transmitting and receiving optical element 41 through the conjugate surface 220 and optical member 20 to the light emitted from the imaging optical system 10. Therefore, the light irradiation device 1 can receive an irradiation beam 51 emitted from a position different from the irradiation position of the other party's irradiation beam 51 to the light irradiation device 1 of the optical wireless communication partner (for example, a predetermined position on the optical element closest to the object in the imaging optical system 10B) (for example, a position different from the predetermined position on the optical element closest to the object in the imaging optical system 10B, that is, a position different from the position from which the irradiation beam 51 from the light irradiation device 1A was incident).

[0079] In this case, the repositioning device 40 may move the light-transmitting optical element (the end of the optical fiber 61-1, the Fresnel lens 42-1, and a lens for focusing the light from the Fresnel lens 42-1 (irradiation beam 51) toward the conjugate surface 220) and the light-receiving optical element (a lens for collimating the divergent light (irradiation beam 51) from the conjugate surface 220 toward the Fresnel lens 42-2, the Fresnel lens 42-2, and the end of the optical fiber 61-2) individually.

[0080] For example, the repositioning device 40 may include a drive device that integrally moves the end of the optical fiber 61-1, the Fresnel lens 42-1, and a lens for focusing the light (irradiation beam 51) from the Fresnel lens 42-1 toward the conjugate surface 220, and a drive device that integrally moves a lens for collimating the light (irradiation beam 51) emitted from the conjugate surface 220 toward the Fresnel lens 42-2, the Fresnel lens 42-2, and the end of the optical fiber 61-2. The end of the optical fiber 61-1, the Fresnel lens 42-1, and the lens for focusing the light (irradiation beam 51) from the Fresnel lens 42-1 toward the conjugate surface 220 may be referred to as the light emission section. At least one of the lens for collimating the light (irradiation beam 51) emitted from the conjugate surface 220 toward the Fresnel lens 42-2, the Fresnel lens 42-2, and the end of the optical fiber 61-2 may be referred to as the light receiving section. In this case, the position changing device 40 can be considered to include a drive device for moving the light emitting unit and a drive device for moving the light receiving unit.

[0081] Furthermore, the positional relationship between the end of the optical fiber 61-1, the Fresnel lens 42-1, and the lens for focusing the light (irradiation beam 51) from the Fresnel lens 42-1 toward the conjugate surface 220 may be fixed by a structure not shown. Also, the positional relationship between the end of the optical fiber 61-2 and the lens for collimating the light (irradiation beam 51) emitted from the conjugate surface 220 toward the Fresnel lens 42-2, the Fresnel lens 42-2, and the end of the optical fiber 61-2 may be fixed by a structure not shown.

[0082] As described above, the position changing device 40 may change the irradiation position of the illumination beam 51 emitted from the imaging optical system 10 by moving the transmitting and receiving optical element 41 in the x-axis direction and the z-axis direction (for example, in a direction perpendicular to the optical axis 111a of the imaging optical system 10) relative to the optical member 20. The control device 50 may change the irradiation position of the illumination beam 51 emitted from the imaging optical system 10 based on the imaging results of the imaging device 30. Specifically, the control device 50 may identify the position of feature locations of an object on the image acquired by the imaging device 30 by the image processing described above. Based on the position of the identified feature locations on the image, the control device 50 may control the position changing device 40 so that the illumination beam 51 emitted from the imaging optical system 10 is incident on the optical illumination device 1 of the other party communicating via optical wireless communication (the transmitting and receiving optical element 41 may be moved). In order to more accurately irradiate the light beam 51 onto the target position of the other party's light irradiation device 1 for optical wireless communication (for example, a specific position on the optical element closest to the object in the imaging optical system 10B), and to more accurately receive the light beam 51 emitted from the other party's light irradiation device 1 for optical wireless communication at the target position (for example, a transmitting / receiving optical system 41 positioned at a specific position in a direction intersecting the optical axis 111a), at least one of the imaging device 30 and the transmitting / receiving optical element 41 may be performed.

[0083] Here, an example of calibration will be described. First, as calibration of the imaging device 30, distortion correction may be performed on the imaging results from the imaging device 30. Next, as calibration of the light transmitting and receiving optical element 41, a correspondence may be made between the position of the light transmitting and receiving optical element 41 in the direction intersecting the optical axis 111a (i.e., the position on the conjugate plane 220 of the irradiation beam 51) and the position on the image acquired by the imaging device 30. As an example of distortion correction of the imaging result by the imaging device 30, distortion correction of the image acquired by the imaging device 30 may be performed by imaging a board with a known shape, such as a checkerboard pattern (hereinafter referred to as the calibration board), with the imaging device 30. The light illumination device 1 may perform distortion correction of the image acquired by the imaging device 30 by a well-known method based on the imaging result of the checkerboard by the imaging device 30. For example, the light illumination device 1 may perform distortion correction of the imaging device 30 by adjusting the well-known image processing conditions of the imaging device 30 based on the comparison result of the imaging result of the calibration board by the imaging device 30 and the shape of the known marks formed on the calibration board. The calibration of the imaging device 30 is performed by imaging the image formed by light through the imaging optical system 10 and the optical member 20 with the imaging device 30, and therefore may be called calibration of the imaging optical system 10 or calibration of the optical member 20. Next, the light irradiation device 1 may associate the position of the light transmitting / receiving optical element 41 in a direction intersecting the optical axis 111a with its position on the image acquired by the imaging device 30. This association between the position of the light transmitting / receiving optical element 41 in a direction intersecting the optical axis 111a and its position on the image acquired by the imaging device 30 may be performed, for example, using a screen or a retroreflective surface (hereinafter simply referred to as a reflective surface).

[0084] The light irradiation device 1 irradiates light from the light transmitting / receiving optical element 41 towards the reflective surface via the imaging optical system 10, and the imaging device 30 receives the light reflected from the reflective surface by the light irradiated from the imaging optical system 10 towards the reflective surface, thereby establishing a correspondence between the position of the light transmitting / receiving optical element 41 in the direction intersecting the optical axis 111a and its position on the image acquired by the imaging device 30. As described above, when the position of the light transmitting / receiving optical element 41 in the direction intersecting the optical axis 111a changes, the irradiation position (irradiation direction) of the light emitted from the imaging optical system 10 changes. Therefore, when the position of the light transmitting / receiving optical element 41 in the direction intersecting the optical axis 111a changes, the reflection position on the reflective surface also changes, and thus the incident position of the reflected light on the imaging device 30 (imaging surface of the image sensor 31) also changes (i.e., the position of the reflected light on the image acquired by the imaging device 30 also changes). The light irradiation device 1 can also be said to perform calibration of the light transmitting and receiving optical element 41 based on the position of the light transmitting and receiving optical element 41 in a direction intersecting the optical axis 111a and the position of the reflected light on the image acquired by the imaging device 30. The calibration of the light transmitting and receiving optical element 41 may also be referred to as calibration between the light transmitting and receiving optical element 41 and the imaging device 30, or calibration of the position changing device 40, or calibration between the position changing device 40 and the imaging device 30. Furthermore, the method of correlating the position of the light transmitting and receiving optical element 41 in a direction intersecting the optical axis 111a with its position on the image acquired by the imaging device 30 is not limited to the method using the reflective surface described above.

[0085] Furthermore, the light illumination device 1 may perform calibration of the imaging device 30 and the light transmitting / receiving optical element 41 using a calibration board (hereinafter referred to as a dual-purpose calibration board) on which both a mark with a known shape for distortion correction and a reflective surface for calibration of the light transmitting / receiving optical element 41 are formed. For example, the light illumination device 1 may be positioned so that the known mark and the reflective surface are included in the field of view of the imaging optical system 1, and may receive reflected light from the reflective surface due to light illumination from the imaging optical system 10 while simultaneously imaging the known mark. By using a dual-purpose calibration board, the imaging device 30 and the light transmitting / receiving optical element 41 can be calibrated simultaneously.

[0086] By performing the above calibration, the accuracy of the irradiation position of the irradiation beam 51 to the target position of the optical irradiation device 1 of the other party communicating via optical wireless communication (for example, a specific position on the optical element closest to the object of the imaging optical system 10B) can be further improved. In addition, the accuracy of the light reception position of the irradiation beam 51 emitted from the optical irradiation device 1 of the other party communicating via optical wireless communication (for example, the positioning accuracy of the transmitting and receiving optical system 41 in the direction intersecting the optical axis 111a) can be further improved. Furthermore, the positional relationship between the imaging device 30 and the light transmitting / receiving optical element 41 may be ensured by improving the mechanical precision of a holding mechanism (not shown) that holds the wide-angle sensor 31 and the light transmitting / receiving optical element 41.

[0087] Next, an example of optical wireless communication performed by the optical irradiation device 1 will be described with reference to Figures 4 to 6. In this example, the optical irradiation system 100 is configured to include multiple optical irradiation devices 1 (for example, optical irradiation device 1A and optical irradiation device 1B), and the case in which optical irradiation device 1A and optical irradiation device 1B communicate via optical wireless communication one-to-one will be described. However, this embodiment is not limited to an example of one-to-one wireless communication, and one-to-N and N-to-M wireless communication (where N and M are natural numbers of 1 or more) may also be performed. Optical wireless communication is not limited to examples of two-way communication, but also includes unidirectional communication, such as transmission only or reception only.

[0088] Figure 4 shows a first example of optical wireless communication according to the first embodiment. In the example shown in the figure, the optical irradiation device 1A and the optical irradiation device 1B are positioned substantially opposite each other in the xy plane. Optical irradiation device 1A irradiates an irradiation beam 51 in the positive x-axis direction. Optical irradiation device 1A also receives an irradiation beam 51 irradiated from optical irradiation device 1B in the negative x-axis direction. Optical irradiation device 1B irradiates an irradiation beam 51 in the negative x-axis direction. Optical irradiation device 1B also receives an irradiation beam 51 irradiated from optical irradiation device 1A in the positive x-axis direction.

[0089] Figure 5 shows a second example of optical wireless communication according to the first embodiment. In the example shown in the figure, the optical irradiation device 1A and the optical irradiation device 1B are installed at positions tilted approximately 90° in the xy plane. Optical irradiation device 1A irradiates an irradiation beam 51 in the positive x-axis direction. Optical irradiation device 1A also receives an irradiation beam 51 irradiated from optical irradiation device 1B in the negative x-axis direction. Optical irradiation device 1B irradiates an irradiation beam 51 in the negative x-axis direction. Optical irradiation device 1B also receives an irradiation beam 51 irradiated from optical irradiation device 1A in the positive x-axis direction.

[0090] Here, we will explain the process when the relative positions of the optical irradiation devices 1A and 1B communicating via optical wireless communication change from the relative positions shown in Figure 4 (hereinafter referred to as the relative positions in Figure 4) to the relative positions shown in Figure 5 (hereinafter referred to as the relative positions in Figure 5). In the following explanation, we will describe the process for optical irradiation device 1A as an example. In this case, optical irradiation device 1A may be installed on the movable body described above. The relative positions of optical irradiation devices 1A and 1B may change as the movable body moves. In addition, the position of optical irradiation device 1B may change as well as that of optical irradiation device 1A. For example, optical irradiation device 1B may be installed on the movable body described above. The relative positions of optical irradiation devices 1A and 1B may change as the movable body moves.

[0091] When the positional relationship changes from that shown in Figure 4 to that shown in Figure 5, the light irradiation device 1A rotates approximately -90° in the xy plane. That is, the position of the light irradiation device 1B changes relative to the light irradiation device 1A. When the position of the light irradiation device 1B changes relative to the light irradiation device 1A, the position of the characteristic area of ​​the light irradiation device 1B (for example, a marker placed on the light irradiation device 1B) on the image acquired by the imaging device 30A also changes. Here, the control device 50A may perform imaging with the imaging device 30A at a predetermined frame rate, and each time an image is acquired, it may identify the position of the characteristic area of ​​the light irradiation device 1B on the acquired image using the image processing described above, and control the position changing device 40A so that the irradiation beam 51 from the light irradiation device 1A is incident on the communication substrate 62B via the imaging optical system 10B. Furthermore, the control device 50A may detect the displacement between the position of the characteristic location of the light illuminator 1B on the image acquired by the imaging device 30A when the positional relationship of the light illuminator 1A and the light illuminator 1B is as shown in Figure 4 during optical wireless communication, and the position of the characteristic location of the light illuminator 1B on the image acquired by the imaging device 30A after the positional relationship of the light illuminator 1A and the light illuminator 1B has changed, and control the position change device 40A based on the detected displacement. In this case, the control device 50A may control the position change device 40A to provide the transmitting and receiving photo-optical elements 41A with a displacement in a direction intersecting the optical axis 111a corresponding to the detected displacement on the image. In other words, the control device 50A may control the position change device 40A based on the displacement of the characteristic location of the light illuminator 1B on the image detected from a plurality of images acquired at a predetermined frame rate.

[0092] Through the processing and control of the control device 50A described above, even if the relative positions of the light irradiator 1A and the light irradiator 1B change due to a change in the position of the light irradiator 1A, the irradiation beam 51 can continue to be irradiated from the light irradiator 1A to the light irradiator 1B (communication board 60B). In other words, even if the relative positions of the light irradiator 1A and the light irradiator 1B change, the light irradiator 1A and the light irradiator 1B can continue optical wireless communication. Furthermore, the above-mentioned processing and control associated with changes in the relative positions of the light irradiation device 1A and the light irradiation device 1B may be performed by the control device 50B instead of the control device 50A, or by the control device 50A and the control device 50B respectively.

[0093] Figure 6 shows a third example of optical wireless communication according to the first embodiment. In the example shown in the figure, the optical irradiation device 1A and the optical irradiation device 1B are installed on substantially the same yz plane and are positioned in substantially the same direction in the xy plane. Optical irradiation device 1A irradiates an irradiation beam 51 in the positive x-axis direction. Optical irradiation device 1A also receives an irradiation beam 51 irradiated from optical irradiation device 1B in the negative x-axis direction. Optical irradiation device 1B irradiates an irradiation beam 51 in the negative x-axis direction. Optical irradiation device 1B also receives an irradiation beam 51 irradiated from optical irradiation device 1A in the positive x-axis direction.

[0094] Furthermore, we will explain the process when the positional relationship of the optical wireless communication devices changes from that shown in Figure 5 to that shown in Figure 6 for the optical irradiation devices 1A and 1B (hereinafter referred to as the positional relationship in Figure 6). In the following explanation, we will describe the process for optical irradiation device 1A as an example. When the positional relationship changes from that shown in Figure 5 to that shown in Figure 6, the light irradiation device 1B rotates approximately 90° in the xy plane. That is, the position of the light irradiation device 1B changes relative to the light irradiation device 1A. As described above, the control device 50A may perform imaging with the imaging device 30A at a predetermined frame rate, and each time an image is acquired, it may identify the position of the characteristic part of the light irradiation device 1B on the acquired image using the image processing described above, and control the position change device 40A so that the irradiation beam 51 from the light irradiation device 1A is incident on the communication substrate 62B. Alternatively, the control device 50A may detect the displacement between the position of the characteristic part of the light irradiation device 1B on the image acquired by the imaging device 30A when the positional relationship of the light irradiation device 1A and the light irradiation device 1B is as shown in Figure 5 in the optical wireless communication state, and the same characteristic part of the light irradiation device 1B on the image acquired by the imaging device 30A after the positional relationship of the light irradiation device 1A and the light irradiation device 1B has changed, and control the position change device 40A based on the detected displacement. In this case, the control device 50A may control the position changing device 40A to provide the transmitting and receiving photo-optical element 41A with a displacement in a direction intersecting the optical axis 111a, corresponding to the displacement on the detected image.

[0095] As a result of the processing by the control device 50A described above, even if the relative positions of the light irradiation device 1A and the light irradiation device 1B change due to a change in the position of the light irradiation device 1B, the light irradiation device 1A and the light irradiation device 1B can continue optical wireless communication. Furthermore, the above-mentioned processing and control associated with changes in the relative positions of the light irradiation device 1A and the light irradiation device 1B may be performed by the control device 50B instead of the control device 50A, or by the control device 50A and the control device 50B respectively.

[0096] In the explanation given with reference to Figures 4 to 6, the case where the positional relationship between the light irradiation device 1A and the light irradiation device 1B changes in the xy plane was described. However, even when the positional relationship changes in the yz plane or the xz plane, the optical wireless communication state between the light irradiation device 1A and the light irradiation device 1B can be maintained by the same processing and control described above.

[0097] Furthermore, during the process of changing the positional relationship from Figure 4 to Figure 5 and then to Figure 6, the light illumination device 1A may vary the frame rate of imaging by the imaging device 30A. For example, the frame rate of the light illumination device 1A may be higher when there is displacement of the light illumination device 1B (e.g., the imaging optical system 10B or a marker placed on the light illumination device 1B) in the image acquired by the imaging device 30A than when there is no such displacement.

[0098] Furthermore, the object to which the light irradiation device 1A communicates via optical wireless communication is not limited to the light irradiation device 1B. For example, the object to which the light irradiation device 1A communicates via optical wireless communication may be a light receiving device described later that can communicate via optical wireless communication with the light irradiation device 1A by receiving the irradiation beam 51 (light for optical wireless communication) from the light irradiation device 1A. For example, the object to which the light irradiation device 1A communicates via optical wireless communication may be a light transmitting device described later that can communicate via optical wireless communication with the light irradiation device 1A by irradiating the light irradiation device 1A with the irradiation beam 51. For example, the object to which the light irradiation device 1A communicates via optical wireless communication may be a light transmitting and receiving device described later that is different from the light irradiation device 1B, which receives the irradiation beam 51 (light for optical wireless communication) from the light irradiation device 1A and communicates via optical wireless communication with the light irradiation device 1A by irradiating the light irradiation device 1A with the irradiation beam 51.

[0099] Figure 7 is a schematic diagram showing a modified example of the light irradiation system according to the first embodiment. Referring to this figure, a modified example of the light irradiation system 100, the optical wireless communication system 100A, will be described. As shown in Figure 7, the optical wireless communication system 100A comprises an optical irradiation device 1, a plurality of light receiving devices 81, a plurality of light transmitting devices 82, and a plurality of light transmitting and receiving devices 83. This embodiment is not limited to this example. The optical wireless communication system 100A may comprise one or more optical irradiation devices 1, and zero or one or more light receiving devices 81, light transmitting devices 82, and light transmitting and receiving devices 83, respectively.

[0100] The light receiving device 81 may be a device that communicates with the light irradiating device 1A via optical wireless communication. The light receiving device 81 may include a light receiving section 811. The light irradiating device 1A can communicate with the light receiving device 81 via optical wireless communication by causing the irradiation beam 51, which is light emitted from the light irradiating device 1A for optical wireless communication, to enter the light receiving section 811. The light receiving device 81 does not need to have a configuration for irradiating the irradiation beam 51. The light receiving section 811 may include a communication board 62. The communication board 62 provided in the light receiving section 811 does not need to have a configuration for generating the irradiation beam 51. In addition to the communication board 62, the light receiving section 811 may include at least one of the following: an imaging optical system 10, an optical member 20, a lens for collimating the light (irradiation beam 51) emitted from the conjugate plane 220 toward the Fresnel lens 42-2, a Fresnel lens 42-2, and an optical fiber 61-2. Furthermore, the light receiving unit 811 may be configured without the component for emitting the irradiation beam 51 from the light irradiation device 1. Furthermore, the light receiving device 81 is not limited to the above configuration and may include an existing configuration that enables optical wireless communication with the light irradiation device 1A by receiving the irradiation beam 51 from the light irradiation device 1A (for example, a light receiving element that converts the received irradiation beam 51 into an electrical signal). Furthermore, the light receiving device 81 may be provided with the above-described characteristic parts. Furthermore, the positional relationship between the characteristic parts of the light receiving device 81 and the light receiving unit 811 of the light receiving device 81 may be known.

[0101] The light-receiving section 811 of the light-receiving device 81 is an example of an object that the light-irradiating device 1A irradiates with the irradiation beam 51. That is, the irradiation beam 51 is irradiated onto the light-receiving section 811. In this example, the irradiation beam 51 may also be referred to as an optical beam for optical wireless communication with the light-receiving device 81. The irradiation beam 51 (optical beam) may also be referred to as highly directional light.

[0102] The light transmitting device 82 may also be a device that communicates with the light irradiation device 1A via optical wireless communication. The light transmitting device 82 may include a light transmitting unit 821. The light transmitting unit 821 may emit an irradiation beam 51 as light for optical wireless communication with the light irradiation device 1A. The light irradiation device 1A can communicate with the light transmitting device 82 via optical wireless communication by receiving the irradiation beam 51 from the light transmitting unit 821 with a light transmitting / receiving optical element 41A (communication board 62A). The light transmitting device 82 does not need to have a configuration for receiving the irradiation beam 51. Furthermore, the light transmitting unit 821 may include a communication board 62. The communication board 62 provided in the light transmitting unit 821 does not necessarily have a configuration for receiving the irradiation beam 51. In addition to the communication board 62, the light transmitting unit 821 may include at least one of the following: an optical fiber 61-1, a Fresnel lens 42-1, a lens for focusing the light (irradiation beam 51) from the Fresnel lens 42-1 toward the conjugate plane 220, an optical element 20, and an imaging optical system 10. Furthermore, the light transmitting unit 821 may omit the configuration for receiving the irradiation beam 51 emitted from the light irradiation device 1. Furthermore, the light transmitting device 82 is not limited to the above configuration and may include an existing configuration (for example, a light-emitting element that converts an electrical signal into an irradiation beam 51) that enables optical wireless communication with the light irradiation device 1A by irradiating the light irradiation device 1A with the irradiation beam 51. Furthermore, the light transmitting device 82 may be provided with the above-described characteristic features. Furthermore, the positional relationship between the characteristic parts of the light transmitting device 82 and the light transmitting unit 821 may be known. Furthermore, the light transmitting device 82 may be referred to as a light emission device or light emission unit. Furthermore, the light transmitting unit 821 may be referred to as a light emission device or light emission unit. In the following description, the light incident on the light irradiation device 1, specifically the irradiation beam 51 emitted from the light transmitting device 82 (light transmitting unit 821), will be referred to as the incident beam 52. The incident beam 52 may also be referred to as the irradiation beam 51 emitted from the light transmitting device 82 for optical wireless communication with the light irradiation device 1A. The incident beam 52 may also be referred to as the light beam for optical wireless communication between the light irradiation device 1A and the light transmitting device 82. The incident beam 52 (light beam) may also be referred to as highly directional light.

[0103] The light transmitting and receiving device 83 may include a light receiving unit 831 and a light transmitting unit 832. The light receiving unit 831 may receive the irradiation beam 51 from the light irradiation device 1A. The light transmitting unit 832 may irradiate the light irradiation device 1A with the irradiation beam 51. The light receiving unit 831 may have the same configuration as the light receiving unit 811 described above. The light transmitting unit 832 may have the same configuration as the light transmitting unit 821 described above. As shown in Figure 7, the light receiving unit 831 and the light transmitting unit 832 may be arranged adjacent to each other on the light transmitting and receiving device 83, or they may be arranged spaced apart. The light transmitting and receiving device 83 may have the same configuration as the light irradiation device 1 described above. In other words, at least one light transmitting and receiving device 83 may be at least one light irradiation device 1 that communicates with the light irradiation device 1A via optical wireless communication. At least one of the light transmitting and receiving devices 83 may be the light irradiation device 1B described above. Furthermore, the light transmitting and receiving device 83 may be provided with the aforementioned characteristic features. The positional relationship between the characteristic features of the light transmitting and receiving device 83 and at least one of the light receiving unit 831 and light transmitting unit 832 of the light transmitting and receiving device 83 may be known.

[0104] Furthermore, the light incident on the light irradiation device 1, specifically the irradiation beam 51 emitted from the light transmitting unit 832 of the light transmitting / receiving device 83, is referred to as the incident beam 52. The incident beam 52 may also be referred to as the irradiation beam 51 emitted from the light transmitting unit 832 of the light transmitting / receiving device 83 for optical wireless communication with the light irradiation device 1. The irradiation beam 51 and the incident beam 52 may also be referred to as the optical beams used for optical wireless communication between the light irradiation device 1A and the light transmitting / receiving device 83. The irradiation beam 51 (optical beam) and the incident beam 52 (optical beam) may also be referred to as highly directional light.

[0105] The light transmitting device 82 may also be an example of a light transmitting and receiving device 83 that includes a light receiving unit 831. In this case, the incident beam 52 is emitted from the light transmitting / receiving device 83, and the irradiation beam 51 is irradiated onto the light receiving unit 831. The incident beam 52 and the irradiation beam 51 may be referred to as light beams for optical wireless communication between the light irradiation device 1A and the light transmitting / receiving device 83, respectively. The light receiving device 81 may be an example of a light transmitting / receiving device 83 that includes a light transmitting unit 821. Hereafter, we will describe the cases in which the light irradiation system 100A is equipped with various combinations of devices.

[0106] First, we will describe an example in which the optical wireless communication system 100A includes an optical irradiation device 1A and a light receiving device 81. The optical wireless communication system 100A may communicate via optical wireless communication between the optical irradiation device 1A and the light receiving device 81 by receiving the irradiation beam 51 from the optical irradiation device 1A with the light receiving unit 811 of the light receiving device 81. In other words, in this example, the optical wireless communication system 100A may transmit information from the optical irradiation device 1A to the light receiving device 81.

[0107] Furthermore, when optical wireless communication is performed between the light irradiation device 1A and the light receiving device 81, the light irradiation device 1A may be configured without the components for receiving the irradiation beam 51. For example, the light irradiation device 1A does not need to be equipped with a lens for collimating the light (irradiation beam 51) emitted from the conjugate surface 220 toward the Fresnel lens 42-2, the Fresnel lens 42-2, and the optical fiber 61-2. For example, the light irradiation device 1A may be equipped with the above-mentioned light transmitting optical element (light emission unit) instead of the light transmitting and receiving optical element 41.

[0108] The control device 50A of the light irradiation device 1A may control the position changing device 40A so that the irradiation beam 51 from the light irradiation device 1A is incident on the light receiving unit 811, based on the position of the characteristic area of ​​the light receiving device 81 as an object on the image acquired by the imaging device 30A, which has been identified by the image processing described above (for example, a marker placed on the light receiving device 81), and the positional relationship between the characteristic area of ​​the light receiving device 81 and the light receiving unit 811 of the light receiving device 81.

[0109] Furthermore, if the positional relationship between the light irradiation device 1A and the light receiving device 81 changes, the control device 50A may perform imaging with the imaging device 30A at a predetermined frame rate, and each time an image is acquired, it may identify the position of a characteristic part of the light receiving device 81 on the acquired image using the image processing described above, and control the position changing device 40A so that the irradiation beam 51 from the light irradiation device 1A is incident on the light receiving unit 811.

[0110] Furthermore, the control device 50A may detect the displacement of the characteristic portion of the light receiving device 81 on the image by identifying the position of the characteristic portion of the light receiving device 81 in the image using the image processing described above for each image acquired at a predetermined frame rate. Based on the displacement of the characteristic portion on the image, the control device 50A may control the position changing device 40A so that the irradiation beam 51 from the light irradiation device 1A is incident on the light receiving unit 811. Through the processing and control of the control device 50A described above, optical wireless communication from the light irradiator 1A to the light receiver 81 can be continued even if the relative positions of the light irradiator 1A and the light receiver 81 change. Furthermore, at least one of the light irradiation device 1A and the light receiving device 81 may be installed on the movable body described above, and the relative positions of the light irradiation device 1A and the light receiving device 81 may be changed by moving the movable body.

[0111] Next, an example will be described in which the optical wireless communication system 100A includes an optical irradiation device 1A and an optical transmission device 82. The optical wireless communication system 100A may communicate via optical wireless communication between the light transmitting device 82 and the light irradiating device 1A by receiving the incident beam 52 from the light transmitting device 82 with the imaging optical system 10A (communication board 62A) of the light irradiating device 1A. In other words, in this example, the optical wireless communication system 100A may transmit information from the light transmitting device 82 to the light irradiating device 1A. When optical wireless communication is performed between the light irradiating device 1A and the light transmitting device 82, the light irradiating device 1A may be configured without the components for emitting the irradiation beam 51. For example, the light irradiating device 1A may not be equipped with an optical fiber 61-1, a Fresnel lens 42-1, and a lens for focusing the light (irradiation beam 51) from the Fresnel lens 42-1 toward the conjugate plane 220. For example, the light irradiating device 1A may be equipped with the above-mentioned photo-receiving optical element (photo-receiving unit) instead of the photo-transmitting and receiving optical element 41.

[0112] The control device 50A may control the position change device 40A so that the incident beam 52 from the light-transmitting unit 821 is incident on the imaging optical system 10A (communication board 62A) based on the position of the characteristic location of the light-transmitting device 82 as an object on the image acquired by the imaging device 30A, which is identified by the image processing described above (for example, a marker placed on the light-transmitting device 82), and the positional relationship between the characteristic location of the light-transmitting device 82 and the light-transmitting unit 821 of the light-transmitting device 82.

[0113] Furthermore, if the positional relationship between the light irradiation device 1A and the light transmitting device 82 changes, the control device 50A may perform imaging with the imaging device 30A at a predetermined frame rate, and each time an image is acquired, it may identify the position of a characteristic part of the light transmitting device 82 on the acquired image using the image processing described above, and control the position changing device 40A so that the incident beam 52 from the light transmitting device 82 is incident on the light transmitting and receiving optical element 41A.

[0114] Furthermore, the control device 50A may detect the displacement of a characteristic location of the light transmitting device 82 on the image by identifying the location of that characteristic location of the light transmitting device 82 in the image using the image processing described above for each image acquired at a predetermined frame rate. Based on the displacement of the characteristic location on the image, the control device 50A may control the position change device 40A so that the incident beam 52 from the light transmitting device 82 is incident on the imaging optical system 10A (communication board 62A). Through the processing and control of the control device 50A described above, optical wireless communication from the light transmitting device 82 to the light transmitting device 1A can be continued even if the positional relationship between the light irradiating device 1A and the light transmitting device 82 changes. Furthermore, at least one of the light irradiation device 1A and the light transmission device 82 is installed on the aforementioned movable body, and the relative positions of the light irradiation device 1A and the light transmission device 82 change as the movable body moves.

[0115] Next, an example of a case in which the optical wireless communication system 100A includes an optical irradiation device 1A and a light transmitting / receiving device 83 will be described. The optical wireless communication system 100A may communicate via optical wireless communication between the optical irradiation device 1A and the light transmitting / receiving device 83 by irradiating an irradiation beam 51 from the optical irradiation device 1A onto the light receiving unit 831 of the light transmitting / receiving device 83, and receiving an incident beam 52 from the light transmitting unit 832 of the light transmitting / receiving device 83 with the imaging optical system 10A (communication board 62A) of the optical irradiation device 1A. In other words, in this example, the optical wireless communication system 100A may send and receive information between the optical irradiation device 1A and the light transmitting / receiving device 83.

[0116] For example, if the light receiving unit 831 and the light transmitting unit 832 are arranged adjacent to or close to each other on the light transmitting / receiving device 83, the control device 50A of the light irradiation device 1A may control the position changing device 40A so that the irradiation beam 51 is incident on the light receiving unit 831, based on the position of the characteristic part of the light transmitting / receiving device 83 as an object on the image acquired by the imaging device 30A, which is identified by the image processing described above (for example, a marker placed on the light transmitting / receiving device 83), and the positional relationship between the characteristic part of the light transmitting / receiving device 83 and the light receiving unit 831 of the light transmitting / receiving device 83. Here, the irradiation beam 51 from the light transmitting unit 832 diffuses to some extent depending on the distance from the light transmitting unit 832, resulting in a broadened light. Therefore, even if the control device 50A moves the light transmitting / receiving optical element 41A so that the irradiation beam 51 is incident on the light receiving unit 831 based on the position of the feature location on the image acquired by the imaging device 30A, the incident beam 52 from the light transmitting unit 832 is incident on the imaging optical system 10A, passes through the optical member 20A, and is incident on the moved light transmitting / receiving optical element 41A (i.e., is incident on the communication board 62A). Alternatively, the control device 50A may control the position changing device 40A so that the incident beam 52 from the light transmitting unit 832 is incident on the light transmitting / receiving optical element 41A based on the position of the feature location of the light transmitting / receiving device 83 as an object on the image acquired by the imaging device 30A, which is identified by the image processing described above, and the positional relationship between the feature location of the light transmitting / receiving device 83 and the light transmitting unit 832 of the light transmitting / receiving device 83.

[0117] Furthermore, if the positional relationship between the light irradiation device 1A and the light transmitting / receiving device 83 changes, the control device 50A may, in the same manner as the processing and control described above, perform imaging with the imaging device 30A at a predetermined frame rate, and each time an image is acquired, identify the position of the characteristic part of the light transmitting / receiving device 83 on the acquired image using the image processing described above, and control the position changing device 40A so that the irradiation beam 51 from the light irradiation device 1A is incident on the light receiving unit 831 (or the incident beam 52 from the light transmitting unit 832 is incident on the light transmitting / receiving optical element 41A).

[0118] Furthermore, the control device 50A may detect the displacement of a characteristic location of the light transmitting / receiving device 83 on the image by identifying the location of that characteristic location of the light transmitting / receiving device 83 in the image for each image acquired at a predetermined frame rate using the image processing described above. Based on the displacement of the characteristic location on the image, the control device 50A may control the position changing device 40A so that the irradiation beam 51 from the light irradiation device 1A is incident on the light receiving unit 831 (or the incident beam 52 from the light transmitting unit 832 is incident on the light transmitting / receiving optical element 41A). Through the processing and control by the control device 50A described above, the light irradiation device 1A and the light transmitting / receiving device 83 can continue bidirectional optical wireless communication even if the positional relationship between the light irradiation device 1A and the light transmitting / receiving device 83 changes.

[0119] As described above, the light transmitting and receiving optical system element 41A may be divided into a light transmitting optical element and a light receiving optical element. As described above, the position changing device 40A may include a drive device for moving the light transmitting optical element and a drive device for moving the light receiving optical element. In this case, the control device 50A may move the light transmitting optical element so that the illumination beam 51 emitted from the imaging optical system 10A via the optical member 20A is incident on the light receiving unit 831, based on the position of the characteristic location of the light transmitting and receiving device 83 on the image acquired by the imaging device 30A, which is identified by the image processing described above (i.e., the control device 50A may control the position changing device 40A). Furthermore, the control device 50A may move the light-receiving optical element so that the incident beam 52 from the light-transmitting unit 832 is incident on the light-receiving optical element via the imaging optical system 10A and the optical member 20A, based on the position of the characteristic location of the light-transmitting / receiving device 83 on the image acquired by the imaging device 30A, which has been identified by the image processing described above, and the positional relationship between the characteristic location of the light-transmitting / receiving device 83 and the light-transmitting unit 832 (i.e., it may control the position-changing device 40A). Through the processing and control of the control device 50A described above, the light-emitting device 1A and the light-transmitting / receiving device 83 can perform bidirectional optical wireless communication even if the light-receiving unit 831 and the light-transmitting unit 832 are not adjacent or close to each other.

[0120] Furthermore, if the relative positions of the light irradiation device 1A and the light transmitting / receiving device 83 change, the control device 50A may perform imaging with the imaging device 30A at a predetermined frame rate, and for each acquired image, it may detect the displacement of the characteristic location of the light transmitting / receiving device 83 on the image by identifying the location of the characteristic location on the image using the image processing described above. Based on the displacement of the characteristic location on the image, the control device 50A may move the light transmitting optical element so that the irradiation beam emitted from the imaging optical system 10A is incident on the light receiving unit 832, or it may move the light receiving optical system so that the incident beam 52 from the light transmitting unit 832 is incident on the imaging optical system 10A (communication board 62A). Through the processing and control by the control device 50A described above, the light irradiation device 1A and the light transmitting / receiving device 83 can continue bidirectional optical wireless communication even if the relative positions of the light irradiation device 1A and the light transmitting / receiving device 83 change. Furthermore, at least one of the light irradiation device 1A and the light transmitting / receiving device 83 may be installed on the movable body described above, and the relative positions of the light irradiation device 1A and the light transmitting / receiving device 83 may be changed by moving the movable body.

[0121] Next, an example of a case in which the optical wireless communication system 100A comprises an optical irradiation device 1A and a plurality of light receiving devices 81 will be described. As an example, a case in which the optical irradiation system 100A comprises an optical irradiation device 1A, a first light receiving device 81-1 as an object (first object), and a second light receiving device 81-2 as an object (second object) will be described. When the optical wireless communication system 100A comprises an optical irradiation device 1A and a plurality of light receiving devices 81, the optical irradiation device 1A may have a plurality of light generating devices 60A depending on the number of light receiving devices 81 as objects to be irradiated. In other words, the optical irradiation device 1A may have a plurality of communication boards 62A, a plurality of optical fibers 61A, and a plurality of light transmitting and receiving optical elements 41. In this case, the optical irradiation device 1A can also be considered to have a plurality of light emitting units.

[0122] For example, if the optical wireless communication system 100A includes two light receiving devices 81 (a first light receiving device 81-1 and a second light receiving device 81-2), the light irradiation device 1A may have two light generating devices 60A (referred to as the first light generating device 60A-1 and the second light generating device 60A-2). In other words, the light irradiation device 1A may have two communication boards 62A (referred to as the first communication board 62A-1 and the second communication board 62A-2), two optical fibers 61 (referred to as the first optical fiber 61-1 and the second optical fiber 61-2), and two light transmitting and receiving optical elements 41A (referred to as the first light transmitting and receiving optical element 41A-1 and the second light transmitting and receiving optical element 41A-2).

[0123] The light irradiation device 1A may emit light (referred to as the first irradiation beam 51-1) for optical wireless communication with the first light receiving device 81-1 generated on the first communication board 62A-1 via the first optical fiber 61-1, the first light transmitting / receiving optical element 41A-1, the optical member 20A, and the imaging optical system 10A. Alternatively, the light irradiation device 1A may emit light (referred to as the second irradiation beam 51-2) for optical wireless communication with the second light receiving device 81-2 generated on the second communication board 62A-2 via the second optical fiber 61-2, the second light transmitting / receiving optical element 41A-2, the optical member 20A, and the imaging optical system 10A.

[0124] Furthermore, the first irradiation beam 51-1 and the second irradiation beam 51-2 may have different optical conditions. For example, the optical conditions include at least one of wavelength, frequency, phase, and polarization state. Furthermore, the light irradiation device 1A may generate the first irradiation beam 51-1 and the second irradiation beam 51-2 using a common communication board 62A. Furthermore, the light irradiation device 1A may be configured without the component for receiving the irradiation beam 51 (incident beam 52). For example, at least one of the light transmitting and receiving optical elements 41-1 and 41-2 may be the light transmitting optical element described above (i.e., the light emission unit). Furthermore, the position changing device 40A moves the first light transmitting / receiving optical element 41-1 and the second light transmitting / receiving optical element 41-2 individually in a direction intersecting the optical axis 111a as described above. For example, the position changing device 40A may include a drive device for moving the first light transmitting / receiving optical element 41-1 in a direction intersecting the optical axis 111a, and a drive device for moving the second light transmitting / receiving optical element 41-2 in a direction intersecting the optical axis 111a. Furthermore, the position changing device 40A may move the first light transmitting and receiving optical element 41-1 and the second light transmitting and receiving optical element 41-2 together in a direction intersecting the optical axis 111a as described above.

[0125] Furthermore, the first light receiving device 81-1 may include a first light receiving unit 811-1, and the second light receiving device 81-2 may include a second light receiving unit 811-2. Furthermore, the first light-receiving device 81-1 and the second light-receiving device 81-2 may each be provided with the aforementioned feature locations. Furthermore, the feature locations provided on the first light-receiving device 81-1 and the feature locations provided on the second light-receiving device 81-2 may be distinguishable. For example, the feature locations installed on the first light-receiving device 81-1 and the feature locations installed on the second light-receiving device 81-2 may be markers of different shapes. In this case, the control device 50A may distinguish and identify the position of the feature location provided on the first light-receiving device 81-1 and the position of the feature location provided on the second light-receiving device 81-2 based on the recognition results of the respective feature locations provided on the two light-receiving devices 81 on the image acquired by the imaging device 30A. Furthermore, the positional relationship between the feature location of the first light-receiving device 81-1 and the first light-receiving unit 811-1 of the first light-receiving device 81-1 may be known. Furthermore, the positional relationship between the characteristic features of the second light-receiving device 81-2 and the second light-receiving section 811-2 of the second light-receiving device 81-2 may be known.

[0126] The optical wireless communication system 100A may transmit optical wireless communication from the optical irradiation device 1A to the first light receiving device 81-1 by receiving the first irradiation beam 51-1, which is emitted from the first light transmitting and receiving optical element 41-1 of the optical irradiation device 1A via the optical member 20A and the imaging optical system 10A, with the light receiving unit 811-1 of the first light receiving device 81-1. Alternatively, the optical wireless communication system 100A may transmit optical wireless communication from the optical irradiation device 1A to the second light receiving device 81-2 by receiving the second irradiation beam 51-2, which is emitted from the second light transmitting and receiving optical element 41-2 of the optical irradiation device 1A via the optical member 20A and the imaging optical system 10A, with the light receiving unit 811-2 of the second light receiving device 81-2. In other words, in this example, the optical wireless communication system 100A may transmit information from the optical irradiation device 1A to the first light receiving device 81-1 and the second light receiving device 81-2.

[0127] The control device 50A of the light irradiation device 1A may move the first light transmitting and receiving optical element 41-1 so that the irradiation beam 51 emitted from the imaging optical system 10a via the optical member 20a from the first light transmitting and receiving optical element 41-1 is incident on the first light receiving unit 811-1, based on the position of the characteristic location of the first light receiving device 81-1 as a first object on the image acquired by the imaging device 30A, which has been identified by the image processing described above (for example, a marker placed on the first light receiving device 81-1), and the positional relationship between the characteristic location of the first light receiving device 81-1 and the first light receiving unit 811-1 (i.e., it may control the position changing device 40A). The control device 50A may move the second light-receiving optical element 41-2 so that the illumination beam 51 emitted from the imaging optical system 10a via the optical member 20a from the second light-receiving optical element 41-2 is incident on the second light-receiving unit 811-2, based on the position of the characteristic location of the second light-receiving device 81-2 as a second object on the image acquired by the imaging device 30A, which has been identified by the image processing described above (for example, a marker placed on the second light-receiving device 81-2), and the positional relationship between the characteristic location of the second light-receiving device 81-2 and the second light-receiving unit 811-2 (i.e., it may control the position changing device 40A). Furthermore, the control device 50A may, based on the characteristic locations of the first light receiving device 81-1 and the second light receiving device 81-2 on the image acquired by the imaging device 30A as identified by the image processing described above, move the first light transmitting and receiving optical element 41-1 so that the irradiation beam 51 emitted from the imaging optical system 10a via the optical member 20a from the first light transmitting and receiving optical element 41-1 is incident on the first light receiving unit 811-1, and move the second light transmitting and receiving optical element 41-2 so that the irradiation beam 51 emitted from the imaging optical system 10a via the optical member 20a from the second light transmitting and receiving optical element 41-2 is incident on the second light receiving unit 811-2.

[0128] Furthermore, even if the positional relationship between at least one of the following changes—the positional relationship between the light irradiation device 1A and the first light receiving device 81-1, and the positional relationship between the light irradiation device 1A and the second light receiving device 81-2—the control device 1A can continue optical wireless communication from the light irradiation device 1A to the first light receiving device 81-1, and from the light irradiation device 1A to the second light receiving device 81-2, through the processing and control described above. Note that the explanation of the processing and control of the control device 1A is omitted as it would be redundant with the explanation above.

[0129] Furthermore, at least one of the light irradiation device 1A, the first light receiving device 81-1, and the second light receiving device 81-2 is installed on the movable body described above, and by moving the movable body, at least one of the positional relationship between the light irradiation device 1A and the first light receiving device 81-1 and the positional relationship between the light irradiation device 1A and the second light receiving device 81-2 may be changed. Furthermore, the optical wireless communication system 100A may include two or more optical irradiators 1. For example, if it includes two optical irradiators 1 (referred to as the first optical irradiator 1A-1 and the second optical irradiator 1A-2), optical wireless communication may be performed from the first optical irradiator 1A-1 to the first optical receiver 81-1, and from the second optical irradiator 1A-2 to the second optical receiver 81-2. Furthermore, the optical wireless communication system 100A may include three or more optical receivers 81. In this case, optical wireless communication may be performed from the optical irradiator 1A to each of the three or more optical receivers 81. Furthermore, the optical irradiator 1A may have three or more optical generators 60A. Furthermore, the optical wireless communication system 100A may include three or more optical irradiators 1.

[0130] Next, an example of a case in which the optical wireless communication system 100A comprises an optical irradiation device 1 and a plurality of light transmitting devices 82 will be described. As an example, a case in which the optical irradiation system 100A comprises an optical irradiation device 1A, a first light transmitting device 82-1 as an object (first object), and a second light transmitting device 82-2 as an object (second object) will be described. When the optical wireless communication system 100A comprises an optical irradiation device 1A and a plurality of light transmitting devices 82, the optical irradiation device 1A may have a plurality of light generating devices 60A in accordance with the number of light transmitting devices 82 as objects to be light-received, as described above. In this case, the optical irradiation device 1A can be considered to have a plurality of light-receiving units.

[0131] For example, if the optical wireless communication system 100A includes two light transmitting devices 82 (a first light transmitting device 82-1 and a second light transmitting device 82-2), the light irradiating device 1A may receive the light for optical wireless communication with the light irradiating device 1A (referred to as the first incident beam 52-1) emitted from the first light transmitting device 82-1 via the imaging optical system 10A, optical member 20A, first light transmitting / receiving optical element 41A-1, and first optical fiber 61-1 on the first communication board 62A-1. Alternatively, the light irradiating device 1A may receive the light for optical wireless communication with the light irradiating device 1A (referred to as the second incident beam 52-2) emitted from the second light transmitting device 82-2 via the imaging optical system 10A, optical member 20A, second light transmitting / receiving optical element 41A-2, and second optical fiber 61-2 on the second communication board 62A-2.

[0132] Furthermore, the first incident beam 52-1 and the second incident beam 52-2 may have different optical conditions. For example, the optical conditions include at least one of wavelength, frequency, phase, and polarization state. The light irradiation device 1A may receive the first incident beam 52-1 and the second incident beam 52-2 on a common communication board 62A. Furthermore, the light irradiation device 1A may be configured without the components for irradiating the irradiation beam 51. For example, at least one of the light transmitting and receiving optical elements 41-1 and 41-2 may be the light receiving optical element (i.e., a light receiving unit) described above.

[0133] Furthermore, the position changing device 40A moves the first light transmitting / receiving optical element 41-1 and the second light transmitting / receiving optical element 41-2 individually in a direction intersecting the optical axis 111a as described above. For example, the position changing device 40A may include a drive device for moving the first light transmitting / receiving optical element 41-1 in a direction intersecting the optical axis 111a, and a drive device for moving the second light transmitting / receiving optical element 41-2 in a direction intersecting the optical axis 111a. Furthermore, the position changing device 40A may move the first light transmitting / receiving optical element 41-1 and the second light transmitting / receiving optical element 41-2 together in a direction intersecting the optical axis 111a as described above.

[0134] Furthermore, the first light transmitting device 82-1 may include a first light transmitting unit 821-1, and the second light transmitting device 82-2 may include a second light transmitting unit 821-2. Furthermore, the first light transmitting device 82-1 and the second light transmitting device 82-2 may each be provided with the aforementioned feature locations. Furthermore, the feature locations provided on the first light transmitting device 82-1 and the feature locations provided on the second light transmitting device 82-2 may be distinguishable. For example, the feature locations installed on the first light transmitting device 82-1 and the feature locations installed on the second light transmitting device 82-2 may be markers of different shapes. In this case, the control device 50A may distinguish and identify the positions of the feature locations provided on the first light transmitting device 82-1 and the feature locations provided on the second light transmitting device 82-2 based on the recognition results of the respective feature locations provided on the two light transmitting devices 82 on the image acquired by the imaging device 30A. Furthermore, the positional relationship between the feature locations of the first light transmitting device 82-1 and the first light transmitting unit 821-1 of the first light transmitting device 82-1 may be known. Furthermore, the positional relationship between the characteristic features of the second light transmitting device 82-2 and the second light transmitting section 821-2 of the second light transmitting device 82-2 may be known.

[0135] The optical wireless communication system 100A may transmit optical wireless communication from the first light transmitting device 82-1 to the light irradiating device 1A by receiving the first incident beam 52-1 emitted from the first light transmitting unit 821-1 of the first light transmitting device 82-1 on the first communication board 62A-1 via the imaging optical system 10A, optical member 20A, and first light transmitting / receiving optical element 41-1 provided in the light irradiating device 1A. Alternatively, the optical wireless communication system 100A may transmit optical wireless communication from the second light transmitting device 82-2 to the light irradiating device 1A by receiving the second incident beam 52-2 emitted from the second light transmitting unit 821-2 of the second light transmitting device 82-2 on the second communication board 62A-2 via the imaging optical system 10A, optical member 20A, and second light transmitting / receiving optical element 41-2 provided in the light irradiating device 1A. In other words, in this example, the optical wireless communication system 100A may transmit information from the first light transmitting device 82-1 and the second light transmitting device 82-2 to the light irradiation device 1A.

[0136] The control device 50A may move the first light transmitting and receiving optical element 41-1 (first communication substrate 62A-1) so that the first incident beam 52-1 emitted from the first light transmitting unit 821-1 is incident on the first light transmitting and receiving optical element 41-1 (first communication substrate 62A-1), based on the position of the characteristic location of the first light transmitting device 82-1 as a first object on the image acquired by the imaging device 30A, which has been identified by the image processing described above (for example, a marker placed on the first light transmitting device 82-1), and the positional relationship between the characteristic location of the first light transmitting device 82-1 and the first light transmitting unit 821-1 of the first light transmitting device 82-1. The control device 50A may move the second light transmitting and receiving optical element 41-2 (second communication board 62A-2) so that the second incident beam 52-2 emitted from the second light transmitting unit 821-2 is incident on the second light transmitting and receiving optical element 41-2 (second communication board 62A-2), based on the position of the characteristic location of the second light transmitting device 82-2 as a second object on the image acquired by the imaging device 30A, which has been identified by the image processing described above (for example, a marker placed on the second light transmitting device 82-2), and the positional relationship between the characteristic location of the second light transmitting device 82-2 and the second light transmitting unit 821-2 of the second light transmitting device 82-2. Furthermore, the control device 50A may, based on the characteristic locations of the first light transmitting device 82-1 and the second light transmitting device 82-2 on the image acquired by the imaging device 30A as identified by the image processing described above, move the first light transmitting and receiving optical element 41-1 (first communication board 62A-1) so that the incident beam 52-1 emitted from the first light transmitting device 82-1 is incident on the first light transmitting and receiving optical element 41-1, and move the second light transmitting and receiving optical element 41-2 (second communication board 62A-2) so that the incident beam 52-2 emitted from the second light transmitting device 82-2 is incident on the second light transmitting and receiving optical element 41-2.

[0137] Furthermore, even if the positional relationship between the light irradiation device 1A and the first light transmitting device 82-1, and the positional relationship between the light irradiation device 1A and the second light transmitting device 82-2, changes, the control device 1A can continue optical wireless communication from the first light transmitting device 82-1 to the light irradiation device 1A, and from the second light transmitting device 82-2 to the light irradiation device 1A, through the processing and control described above. Note that the explanation of the processing and control of the control device 1A is omitted as it would be redundant with the explanation above.

[0138] Furthermore, at least one of the light irradiation device 1A, the first light transmitting device 82-1, and the second light transmitting device 82-2 is installed on the movable body described above, and by moving the movable body, at least one of the positional relationship between the light irradiation device 1A and the first light transmitting device 82-1 and the positional relationship between the light irradiation device 1A and the second light transmitting device 82-2 may be changed. Furthermore, the optical wireless communication system 100A may include two or more optical irradiation devices 1. For example, if it includes two optical irradiation devices 1, optical wireless communication may be performed from the first light transmitting device 82-1 to the first optical irradiation device 1A-1, and from the second light transmitting device 82-2 to the second optical irradiation device 1A-2. Furthermore, the optical wireless communication system 100A may include three or more light transmitting devices 82. In this case, optical wireless communication may be performed from each of the three or more light transmitting devices 82 to the optical irradiation device 1. Furthermore, the optical irradiation device 1A may have three or more light generating devices 60A. Furthermore, the optical wireless communication system 100A may include three or more optical irradiation devices 1.

[0139] Next, an example of a case in which the optical wireless communication system 100A includes an optical irradiation device 1 and a plurality of light transmitting and receiving devices 82 will be described. As an example, let us describe a case where the light irradiation system 100A comprises a light irradiation device 1A, a first light transmitting / receiving device 83-1 as an object (first object), and a second light transmitting / receiving device 83-2 as an object (second object). If the optical wireless communication system 100A comprises a light irradiation device 1A and a plurality of light transmitting / receiving devices 83, the light irradiation device 1A may have a plurality of light generating devices 60A in accordance with the number of light transmitting / receiving devices 83 as objects to be irradiated and light received, as described above. In this case, the light irradiation device 1A can be considered to have a plurality of light emitting units and a plurality of light receiving units.

[0140] For example, if the optical wireless communication system 100A includes two light transmitting and receiving devices 83 (a first light transmitting and receiving device 83-1 and a second light transmitting and receiving device 83-2), the light irradiation device 1A may emit a first irradiation beam 51-1 generated by a first communication substrate 62A-1 from the imaging optical system 10A, or it may receive a first incident beam 52-1 for optical wireless communication with the light irradiation device 1A emitted from the first light transmitting and receiving device 83-1 via the imaging optical system 10A at a first light transmitting and receiving optical element 41A-1 (first communication substrate 62A-1). Furthermore, the light irradiation device 1A may emit a second irradiation beam 51-2 generated by the second communication board 62A-2 from the imaging optical system 10A, and may receive a second incident beam 52-2 for optical wireless communication with the light irradiation device 1A, emitted from the second light transmitting / receiving device 83-2, via the imaging optical system 10A to the second light transmitting / receiving optical element 41A-2 (second communication board 62A-2).

[0141] Furthermore, the optical conditions of the first irradiation beam 51-1 and the second irradiation beam 51-2 may be different. Also, the optical conditions of the second incident beam 52-1 and the second incident beam 52-2 may be different. Furthermore, the optical conditions of the first irradiation beam 51-1 and the first incident beam 52-1 may be the same. Also, the optical conditions of the second irradiation beam 51-2 and the second incident beam 52-2 may be the same. For example, the optical conditions include at least one of wavelength, frequency, phase, and polarization state. Furthermore, the light irradiation device 1A may generate the first irradiation beam 51-1 and the second irradiation beam 51-2 on a common communication board 62A. Also, the light irradiation device 1A may receive the first incident beam 52-1 and the second incident beam 52-2 on a common communication board 62A.

[0142] Furthermore, the position changing device 40A moves the first light transmitting / receiving optical element 41A-1 and the second light transmitting / receiving optical element 41A-2 individually in a direction intersecting the optical axis 111a as described above. For example, the position changing device 40A may include a drive device for moving the first light transmitting / receiving optical element 41A-1 in a direction intersecting the optical axis 111a, and a drive device for moving the second light transmitting / receiving optical element 41A-2 in a direction intersecting the optical axis 111a. Furthermore, the position changing device 40A may move the first light transmitting / receiving optical element 41A-1 and the second light transmitting / receiving optical element 41A-2 together in a direction intersecting the optical axis 111a as described above.

[0143] Furthermore, the first light transmitting and receiving device 83-1 may include at least one of the first light receiving unit 831-1 and the first light transmitting unit 832-1, and the second light transmitting and receiving device 83-2 may include at least one of the second light receiving unit 831-2 and the second light transmitting unit 832-2. Furthermore, the first light-transmitting / receiving device 83-1 and the second light-transmitting / receiving device 83-2 may each be provided with the aforementioned feature locations. Furthermore, the feature locations provided on the first light-transmitting / receiving device 83-1 and the feature locations provided on the second light-transmitting / receiving device 83-2 may be distinguishable. For example, the feature locations installed on the first light-transmitting / receiving device 83-1 and the feature locations installed on the second light-transmitting / receiving device 83-2 may be markers of different shapes. In this case, the control device 50A may distinguish and identify the position of the feature location provided on the first light-transmitting / receiving device 83-1 and the position of the feature location provided on the second light-transmitting / receiving device 83-2 based on the recognition results of the respective feature locations provided on the two light-transmitting / receiving devices 83 on the image acquired by the imaging device 30A.

[0144] Furthermore, the positional relationship between the characteristic parts of the first light transmitting / receiving device 83-1 and at least one of the first light receiving section 831-1 and the first light transmitting section 832-1 of the first light transmitting / receiving device 83-1 may be known. Furthermore, the positional relationship between the characteristic parts of the second light transmitting / receiving device 83-2 and at least one of the second light receiving section 831-2 and the second light transmitting section 832-2 of the second light transmitting / receiving device 83-2 may be known.

[0145] The light irradiation system 100A may communicate via optical wireless communication between the light irradiation device 1A and the first light transmitting / receiving device 83-1 by irradiating the first light receiving unit 831-1 of the first light transmitting / receiving device 83-1 with the first irradiation beam 51-1 emitted from the first light transmitting / receiving optical element 41A-1 of the light irradiation device 1A via the optical member 20A and the imaging optical system 10A, and receiving the first incident beam 52-1 from the first light transmitting unit 832-1 of the first light transmitting / receiving device 83-1 with the first communication board 62A-1 via the imaging optical system 10A, the optical member 20A, and the first light transmitting / receiving optical element 41A-1 of the light irradiation device 1A.

[0146] Furthermore, the light irradiation system 100A may also communicate via optical wireless communication between the light irradiation device 1A and the second light transmitting / receiving device 83-2 by irradiating the second irradiation beam 51-2, emitted from the second light transmitting / receiving optical element 41A-2 of the light irradiation device 1A via the optical member 20A and the imaging optical system 10A, onto the second light receiving unit 831-2 of the second light transmitting / receiving device 83-2, and receiving the second incident beam 52-2 from the second light transmitting unit 832-2 of the second light transmitting / receiving device 83-2 on the second communication board 62A-2 via the imaging optical system 10A, the optical member 20A, and the second light transmitting / receiving optical element 41A-2 of the light irradiation device 1A. In other words, in this example, the optical wireless communication system 100A may send and receive information between the light irradiation device 1A and the first light transmitting / receiving device 83-1, or send and receive information between the light irradiation device 1A and the second light transmitting / receiving device 83-2.

[0147] For example, if the first light receiving unit 831-1 and the first light transmitting unit 832-1 of the first light transmitting / receiving device 83-1 are arranged adjacent to or close to each other, the control device 50A may move the first light transmitting / receiving optical element 41A-1 so that the first irradiation beam 51-1 emitted from the imaging optical system 10A via the optical member 20A from the first light transmitting / receiving optical element 41A-1 is incident on the first light receiving unit 831-1, based on the position of a characteristic location of the first light transmitting / receiving device 83-1 on the image acquired by the imaging device 30A, which has been identified by the image processing described above (for example, a marker placed on the first light transmitting / receiving device 83-1), and the positional relationship between the characteristic location of the first light transmitting / receiving device 83-1 and the first light receiving unit 831-1. Here, the first irradiation beam 51-1 from the first light transmitting unit 832-1 diffuses to some extent depending on the distance from the first light transmitting unit 832-1, resulting in a broadened beam of light. Therefore, even when the control device 50A moves the first light transmitting and receiving optical element 41A-1 so that the first irradiation beam 51-1 is incident on the first light receiving unit 831-1, the first incident beam 52-1 from the first light transmitting unit 832-1 is incident on the imaging optical system 10A, passes through the optical member 20A, and is incident on the moved first light transmitting and receiving optical element 41A-1 (i.e., is incident on the first communication substrate 62A-1).

[0148] Furthermore, the control device 50A may control the position changing device 40A so that the first incident beam 52-1 from the first light transmitting unit 832-1 is incident on the first light transmitting optical element 41A-1, based on the position of the characteristic location of the first light transmitting device 83-1 as an object on the image acquired by the imaging device 30A, which has been identified by the image processing described above, and the positional relationship between the characteristic location of the first light transmitting device 83-1 and the first light transmitting unit 832-1 of the first light transmitting device 83-1.

[0149] Furthermore, if the positional relationship between the light irradiation device 1A and the first light transmitting / receiving device 83-1 changes, the control device 50A may, in the same manner as the processing and control described above, perform imaging with the imaging device 30A at a predetermined frame rate, and each time an image is acquired, identify the position of a characteristic part of the first light transmitting / receiving device 83-1 on the acquired image using the image processing described above, and control the position changing device 40A so that the first irradiation beam 51-1 from the light irradiation device 1A is incident on the first light receiving unit 831-1 (or the first incident beam 52-1 from the first light transmitting unit 832-1 is incident on the first light transmitting / receiving optical element 41A-1).

[0150] Furthermore, the control device 50A may detect the displacement of the characteristic location of the first light transmitting / receiving device 83-1 on the image by identifying the position of the characteristic location of the first light transmitting / receiving device 83-1 in the image using the image processing described above for each image acquired at a predetermined frame rate. Based on the displacement of the characteristic location on the image, the control device 50A may control the position changing device 40A so that the first irradiation beam 51-1 from the light irradiation device 1A is incident on the first light receiving unit 831-1 (or the first incident beam 52-1 from the first light transmitting unit 832-1 is incident on the first light transmitting / receiving optical element 41A-1). Through the processing and control by the control device 50A described above, the light irradiation device 1A and the first light transmitting / receiving device 83-1 can continue bidirectional optical wireless communication even if the positional relationship between the light irradiation device 1A and the first light transmitting / receiving device 83-1 changes.

[0151] As described above, the first light transmitting and receiving optical system element 41A-1 may be divided into a light transmitting optical element (which may be called the first light transmitting optical element in this case) and a light receiving optical element (which may be called the first light receiving optical element in this case). As described above, the position changing device 40A may include a drive device for moving the light transmitting optical element and a drive device for moving the light receiving optical element. In this case, the control device 50A may move the light transmitting optical element so that the first irradiation beam 51-1 emitted from the imaging optical system 10A via the optical member 20A is incident on the first light receiving unit 831-1, based on the position of the characteristic location of the first light transmitting and receiving device 83-1 on the image acquired by the imaging device 30A, which has been identified by the image processing described above, and the positional relationship between the characteristic location of the first light transmitting and receiving device 83-1 and the first light receiving unit 831-1. Based on the position of the characteristic area of ​​the first light transmitting / receiving device 83-1 on the image acquired by the imaging device 30A, which has been identified by the image processing described above, and the positional relationship between the characteristic area of ​​the first light transmitting / receiving device 83-1 and the first light transmitting unit 832-1, the control device 50A may move the light-receiving optical element so that the first incident beam 52-1 from the first light transmitting unit 832-1 is incident on the light-receiving optical element via the imaging optical system 10A and the optical member 20A. Through the processing and control of the control device 50A described above, the light irradiation device 1A and the first light transmitting / receiving device 83-1 can perform bidirectional optical wireless communication even if the first light-receiving unit 831-1 and the first light transmitting unit 832-1 of the first light transmitting / receiving device 83-1 are not arranged adjacent to or close to each other.

[0152] Furthermore, if the positional relationship between the light irradiation device 1A and the first light transmitting / receiving device 83-1 changes, the control device 50A may perform imaging with the imaging device 30A at a predetermined frame rate, and for each acquired image, it may detect the displacement of the characteristic location on the image by identifying the position of the characteristic location of the first light transmitting / receiving device 83-1 using the image processing described above. Based on the displacement of the characteristic location on the image, the control device 50A may move the light transmitting optical element so that the first irradiation beam 51-1 emitted from the imaging optical system 10A is incident on the first light receiving unit 832-1, or it may move the light receiving optical element so that the first incident beam 52-1 from the first light transmitting unit 832-1 is incident on the light receiving optical element via the imaging optical system 10A. Through the processing and control by the control device 50A described above, the light irradiation device 1A and the first light transmitting / receiving device 83-1 can continue bidirectional optical wireless communication even if the positional relationship between the light irradiation device 1A and the first light transmitting / receiving device 83-1 changes.

[0153] Furthermore, at least one of the light irradiation device 1A and the first light transmitting / receiving device 83-1 may be mounted on the aforementioned movable body, and the relative positions of the light irradiation device 1A and the first light transmitting / receiving device 83-1 may be changed by moving the movable body. Furthermore, the processing and control of the control device 50A when the light irradiation device 1A and the second light transmitting / receiving device 83-2 communicate via optical wireless communication is the same as the processing and control of the control device 50A when the light irradiation device 1A and the first light transmitting / receiving device 83-1 communicate via optical wireless communication (that is, the processing and control when the control target of the control device 50A in the above description is replaced from the first light transmitting / receiving optical element 41A-1 to the second light transmitting / receiving optical element 41A-2, and the first light transmitting / receiving device 83-1 is replaced to the second light transmitting / receiving device 83-2), so the explanation is omitted.

[0154] Furthermore, the optical wireless communication system 100A may include two or more optical irradiators 1. For example, if it includes two optical irradiators 1, optical wireless communication may be performed between the first optical irradiator 1A-1 (as the first optical irradiator) and the first light transmitter / receiver 83-1, and optical wireless communication may be performed between the second optical irradiator 1A-2 (as the second optical irradiator) and the second light transmitter / receiver 83-2. Furthermore, the optical wireless communication system 100A may include three or more light transmitters / receivers 83. In this case, optical wireless communication may be performed between each of the three or more light transmitters / receivers 83 and the optical irradiator 1A. Furthermore, the optical irradiator 1A may have three or more light generators 60A. Furthermore, the optical wireless communication system 100A may include three or more optical irradiators 1.

[0155] As described above, according to this embodiment, the light irradiation device 1 comprises an imaging optical system 10, an optical member 20, an imaging device 30, a position changing device 40, and a control device 50, thereby irradiating an object with an irradiation beam 51 from a light generator 60. The light irradiation device 1, by comprising the optical member 20, emits light incident via the imaging optical system 10 toward the image plane 210 of the imaging optical system 10, and also emits the irradiation beam 51 from the light generator 60, which is incident via a conjugate plane 220 conjugate to the image plane 210, toward the imaging optical system 10. The light irradiation device 1, by comprising the imaging device 30, captures at least a portion of the image of the object formed on the image plane 210 by the imaging optical system 10. The light irradiation device 1, by comprising the position changing device 40, changes the position of the irradiation beam 51 from the light generator 60 on the conjugate plane 220, thereby changing the irradiation position of the irradiation beam 51 emitted from the imaging optical system 10. The light irradiation device 1, equipped with a control device 50, controls the position changing device 40 based on the imaging results of the imaging device 30 to irradiate at least a portion of the object with the irradiation beam 51 emitted from the imaging optical system 10. Therefore, according to this embodiment, the irradiation beam 51 can be irradiated to a position corresponding to the position of the object.

[0156] Furthermore, according to the embodiment described above, the imaging optical system 10 is telecentric on the conjugate plane 220 side. Therefore, according to this embodiment, it is not necessary to adjust the angle of the irradiation beam 51 emitted from the phototransmitting and receiving optical element 41, and the phototransmitting and receiving optical element 41 can be easily controlled.

[0157] Furthermore, according to the embodiment described above, the maximum field of view of the imaging optical system 10 is 170° or more. Therefore, the light irradiation device 1 can irradiate a wide area with the irradiation beam 51.

[0158] Furthermore, according to the above-described embodiment, the imaging optical system 10 forms a reduced image of the object on the image plane 210. That is, the light irradiation device 1 can transmit and receive light over a field of view corresponding to the magnification ratio of the imaging optical system 10, within the range in which the light transmitting and receiving optical element 41 can move. Therefore, the light irradiation device 1 can receive light over a wide field of view and transmit light over a wide field of view. It is also possible to increase the amount of change in the direction of light transmission relative to the movement distance of the light transmitting and receiving optical element 41. Therefore, the direction of light transmission can be changed at high speed. Moreover, even if the incident direction of the light incident on the light irradiation device 1 is changed significantly, the movement distance of the light transmitting and receiving optical element 41 can be reduced. Therefore, it becomes easy to follow changes even if the incident direction changes significantly in a short period of time.

[0159] Furthermore, according to the embodiment described above, the control device 50 controls the position changing device 40 based on the characteristic locations of the object detected based on the imaging results captured by the imaging device 30. Therefore, the light irradiation device 1 can easily track the object even if it moves.

[0160] Furthermore, according to the embodiment described above, the imaging device 30 has multiple pixels. By having multiple pixels, the imaging device 30 can accurately determine the position of an object.

[0161] Furthermore, according to the embodiment described above, the light irradiation device 1 emits an irradiation beam 51 onto the optical member 20 by including a light emission unit (transmitting and receiving optical element 41), and moves the light emission unit in a direction intersecting the optical axis 111 on the light emission unit side of the imaging optical system 10 by including a position changing device 40. In other words, the light irradiation device 1 changes the irradiation position of the irradiation beam 51 by moving the position of the transmitting and receiving optical element 41. Therefore, according to this embodiment, the light irradiation device 1 can easily change the position to which the irradiation beam 51 is irradiated, and can easily track an object.

[0162] Furthermore, according to the embodiment described above, the light-receiving unit 831 of the light-receiving device 81 is an example of an object that the light-irradiating device 1 irradiates with the irradiation beam 51. That is, the irradiation beam 51 is irradiated onto the light-receiving unit 831. Therefore, the light-irradiating device 1 can communicate with the light-receiving device 81 via optical wireless communication.

[0163] Furthermore, according to the embodiment described above, the light irradiation device 1, by including a light receiving unit 120, receives the incident beam 52 emitted from the light emission unit (light transmitting unit) of the light transmitting device 82 (which is a physical object) and incident on the imaging optical system 10 via the optical member 20. Therefore, the light irradiation device 1 can easily communicate with the light transmitting device 82 via optical wireless communication.

[0164] Furthermore, according to the embodiment described above, the light-receiving unit 120 receives the incident beam 52 via the conjugate surface 220. Therefore, according to this embodiment, by moving the light-receiving unit 120 to the position captured by the imaging device 30, the position of the light-receiving unit 120 can be aligned with the position into which the incident beam 52 is incident.

[0165] Furthermore, according to the embodiment described above, the incident beam 52 is an optical beam for optical wireless communication between the light irradiation device 1 and the light transmitting device 82. Therefore, according to this embodiment, the light irradiation device 1 can communicate with the light transmitting device 82 via optical wireless communication.

[0166] Furthermore, according to the embodiment described above, the light transmitting device 82 is an example of a light transmitting and receiving device 83 including a light receiving unit 831, the incident beam 52 is emitted from the light transmitting and receiving device 83, and the irradiation beam 51 is irradiated onto the light receiving unit 831. The incident beam 52 and the irradiation beam 51 are, respectively, light beams for optical wireless communication with the light transmitting and receiving device 83. Therefore, according to this embodiment, the light irradiation device 1 can communicate with the light transmitting device 82 via optical wireless communication.

[0167] Furthermore, according to the embodiment described above, an image of at least a portion of a second object, which is different from the first object, is formed on the image plane 210 by the imaging optical system 10, and the imaging device 30 captures images of at least a portion of the first object and at least a portion of the second object. In other words, the imaging device 30 captures images of two objects. The light irradiation device 1 emits a first irradiation beam to the first object based on the position of the first object that has been imaged, and a second irradiation beam to the second object based on the position of the second object that has been imaged. Therefore, the light irradiation device 1 can simultaneously irradiate multiple light receiving devices 81 with the irradiation beam 51.

[0168] Furthermore, according to the embodiment described above, the first object is at least a part of the first light receiving device 81-1, and the second object is at least a part of the second light receiving device 81-2. The first irradiation beam 51-1 is irradiated onto the light receiving part (first light receiving part 811-1) of the first light receiving device 81-1, and the second irradiation beam 51-2 is irradiated onto the light receiving part (second light receiving part 811-2) of the second light receiving device 81-2. Therefore, the light irradiation device 1 can irradiate multiple light receiving devices 81 simultaneously with the irradiation beam 51.

[0169] Furthermore, according to the embodiment described above, the light irradiation device 1 further includes a light receiving unit to receive the first incident beam 52-1 and the second incident beam 52-2 via the optical member 20. Therefore, the light irradiation device 1 can simultaneously receive the incident beams 52 irradiated from multiple light transmitting devices 82.

[0170] Furthermore, according to the embodiment described above, the first light transmitting device 82-1 may be a first light transmitting / receiving device 83-1 including a light receiving unit 831-1, and the second light transmitting device 82-2 may be a second light transmitting / receiving device 83-2 including a light receiving unit 831-2. Therefore, according to this embodiment, the light irradiation device 1 can communicate wirelessly with a plurality of light transmitting / receiving devices 83.

[0171] Furthermore, according to the embodiment described above, the optical wireless communication system 100A receives the irradiation beam 51 from the optical irradiation device 1 with the light receiving unit 811 of the light receiving device 81, thereby enabling the optical irradiation device 1 and the light receiving device 81 to communicate via optical wireless communication. Therefore, according to this embodiment, in the optical wireless communication system 100A, the optical irradiation device 1 can transmit information to the light receiving device 81.

[0172] Furthermore, according to the embodiment described above, the optical wireless communication system 100A receives the incident beam 52 from the light transmitting device 82 at the light receiving unit of the light irradiation device 1, thereby enabling the light transmitting device 82 and the light irradiation device 1 to communicate via optical wireless communication. Therefore, according to this embodiment, in the optical wireless communication system 100A, the light irradiation device 1 can receive information from the light transmitting device 82.

[0173] Furthermore, according to the embodiment described above, the optical wireless communication system 100A transmits and receives an irradiation beam 51 from the optical irradiation device 1 to the light receiving unit 831 of the light transmitting and receiving device 83, and the optical irradiation device 1 receives an incident beam 52 from the light transmitting and receiving device 83 at the light receiving unit of the optical irradiation device 1, thereby enabling optical wireless communication between the optical irradiation device 1 and the light transmitting and receiving device 83. Therefore, according to this embodiment, in the optical wireless communication system 100A, the optical irradiation device 1 can send and receive information with the light transmitting and receiving device 83.

[0174] Furthermore, according to the embodiment described above, the optical wireless communication system 100A receives the first irradiation beam 51-1 from the light irradiation device 1 with the light receiving unit (first light receiving unit 811-1) of the first light receiving device 81-1, and receives the second irradiation beam 51-2 with the light receiving unit (second light receiving unit 811-2) of the second light receiving device 81-2. Therefore, according to this embodiment, the optical wireless communication system 100A can transmit information from the light irradiation device 1 to a plurality of light receiving devices 81.

[0175] Furthermore, according to the embodiment described above, the light receiving unit of the light irradiation device 1 receives the first incident beam 52-1 from the first light transmitting device 82-1 and the second incident beam 52-2 from the second light transmitting device 82-2, thereby communicating with the first light transmitting device 82-1 and the second light transmitting device 82-2 via optical wireless communication. Therefore, according to this embodiment, the light irradiation device 1 can simultaneously receive information transmitted from multiple light transmitting devices 82.

[0176] Furthermore, according to the embodiment described above, the light irradiation device 1 irradiates the light receiving unit (first light receiving unit 831-1) of the first light transmitting / receiving device 83-1 with the first irradiation beam 51-1, and irradiates the light receiving unit (second light receiving unit 831-2) of the second light transmitting / receiving device 83-2 with the second irradiation beam 51-2. Therefore, according to this embodiment, the light irradiation device 1 can simultaneously transmit information to multiple light transmitting / receiving devices 83. In this embodiment, at least one of the irradiation beam 51 and the incident beam 52 is not limited to light for optical wireless communication. For example, at least one of the irradiation beam 51 and the incident beam 52 may be light for optical wireless power transmission. The wavelength of the light for optical wireless power transmission may be in the infrared wavelength band, the ultraviolet wavelength band, or the visible light wavelength band. The output power of the light for optical wireless power transmission may be several watts, several tens of watts, or several kilowatts. For example, if the irradiation beam 51 is used as light for optical wireless power transmission, the light irradiation device 1A may supply power to the device to be optically wirelessly powered (for example, at least one of the light irradiation device 1B, the light receiving device 82, and the light transmitting / receiving device 83) by irradiating it with the irradiation beam 51 through the processing and control of the control device 50 described above. The light irradiation device 1A may also be referred to as a power supply device.

[0177] [Second Embodiment] Figure 8 is a schematic diagram illustrating the configuration of a light irradiation device according to the second embodiment. The light irradiation device 1C according to the second embodiment will be described with reference to this figure. The light irradiation device 1C differs from the light irradiation device 1 in that it includes an optical system 70. Furthermore, the light irradiation device 1C differs from the light irradiation device 1 in that it includes a position change device 40C instead of a position change device 40. The light irradiation device 1C may also be provided with the above-mentioned characteristic features. The light irradiation device 1C may be installed on the above-mentioned movable body. In the description of the light irradiation device 1C, components similar to those in the light irradiation device 1 may be denoted by the same reference numerals, and their description may be omitted. Figure 8 omits the illustration of the control device 50 and part of the light generator 6 (optical fiber 61, communication board 62). In this embodiment, the light irradiation system 100 may perform optical wireless communication.

[0178] The optical system 70 may be installed between the light transmitting / receiving optical element 41 and the optical member 20. When the optical system 70 is installed, a first conjugate surface 221 and a second conjugate surface 222 are formed as the conjugate surface 220, as shown in Figure 8. For example, the first conjugate surface 221 may be formed in the same position as the conjugate surface 220 described above, or it may be formed in a different position. The second conjugate surface 222 is formed between the phototransmitting / receiving optical element 41 and the optical system 70, and is a surface conjugate to the first conjugate surface 221. The position changing device 40C changes the position of the irradiation beam 51 from the light generator 60 on the second conjugate surface 222 by moving the phototransmitting / receiving optical element 41. It can also be said that the second conjugate surface 222 is formed between the position changing device 40C and the optical system 70.

[0179] The irradiation beam 51 from the light transmitting / receiving optical element 41 (light generator 60) enters the optical system 70 via the second conjugate surface 222. The irradiation beam 51 emitted from the optical system 70 then enters the optical member 20 via the first conjugate surface 221. It can also be said that the irradiation beam 51 from the light transmitting / receiving optical element 41 enters the optical member 20 via the conjugate surface 220.

[0180] The position changing device 40C may change the position of the irradiation beam 51 on the second conjugate plane 222 by changing the position of the transmitting / receiving optical element 41 on the xz plane. Since the second conjugate plane 222 is the conjugate plane 220, it can also be said that the position changing device 40C changes the position of the irradiation beam 51 on the conjugate plane 220. The position changing device 40C may also change the irradiation position of the irradiation beam 51 emitted from the imaging optical system 10. Specifically, the position changing device 40C may be a drive device for changing the position of the irradiation beam 51 from the transmitting / receiving optical element 41 on the second conjugate plane 222. The position changing device 40 may change the irradiation position of the irradiation beam 51 emitted from the imaging optical system 10 by changing the position of the irradiation beam 51 from the transmitting / receiving optical element 41 on the second conjugate plane 222.

[0181] Furthermore, when the position of the irradiation beam 51 from the light transmitting / receiving optical element 41 on the second conjugate surface 222 changes, the position at which the irradiation beam 51 enters the imaging optical system 10 via the optical system 70 and optical member 20 changes. As the entry position of the irradiation beam 51 from the optical member 20 to the imaging optical system 10 changes, the irradiation position of the irradiation beam 51 emitted from the imaging optical system 10 changes. It can also be said that the position changing device 40C changes the irradiation direction of the irradiation beam 51 emitted from the imaging optical system 10 by changing the position of the irradiation beam 51 from the light transmitting / receiving optical element 41 on the second conjugate surface 222.

[0182] The position changing device 40C may be a drive device for moving the light transmitting / receiving optical element 41 of the light irradiation device 1C, similar to the position changing device 40. The position changing device 40C may be a drive device for moving the light generating device 60. The position changing device 40C may be a drive device for moving the light transmitting / receiving optical element 41 relative to the optical system 70, optical member 20, imaging optical system 10, and imaging device 30. The position changing device 40C may be a well-known drive device such as a linear motor or stepping motor capable of moving the light transmitting / receiving optical element 41. The position changing device 40 may be a drive device for moving the optical system 70, optical member 20, imaging optical system 10, and imaging device 30 relative to the light transmitting / receiving optical element 41.

[0183] Here, the optical axis 111 of the imaging optical system 10, from the optical element 20 to the second conjugate plane 222 (conjugate plane 220), can be referred to as optical axis 111c, and the optical axis 111b can be referred to from the optical element 20 to the image plane 210. Furthermore, optical axis 111c may be referred to as the optical axis on the second conjugate plane 222 side (i.e., the conjugate plane 220 side) of the imaging optical system 10. Also, optical axis 111b may be referred to as the optical axis on the image plane 210 side of the imaging optical system 10. In this case, the position changing device 40C can be said to move the transmitting / receiving optical element 41 in a direction intersecting the optical axis 111c. Alternatively, the position changing device 40C can be said to move the transmitting / receiving optical element 41 in a direction perpendicular to the optical axis 111c. Finally, the position changing device 40C can be said to move the transmitting / receiving optical element 41 within a plane intersecting the optical axis 111c. The position changing device 40C may change the position of the irradiation beam 51 from the light transmitting and receiving optical element 41 on the second conjugate plane 222 by moving the light transmitting and receiving optical element 41 as described above. As mentioned above, since the light transmitting and receiving optical element 41 can be considered as a light emission unit, the optical axis 111c may be referred to as the optical axis on the light emission unit side of the imaging optical system 10. Also, as mentioned above, since the light transmitting and receiving optical element 41 can be considered as a light receiving unit, the optical axis 111c may be referred to as the optical axis on the light receiving unit side of the imaging optical system 10. As mentioned above, since the light transmitting and receiving optical element 41 can be considered as a light transmitting and receiving unit, the optical axis 111c may be referred to as the optical axis on the light transmitting and receiving unit side of the imaging optical system 10.

[0184] The position changing device 40C may, for example, move the transmitting and receiving photo-optical element 41 in the direction of arrow 410, thereby moving the irradiation position of the irradiation beam 51 in the direction of arrow 410C. Furthermore, the position changing device 40C changes the receiving position of the incident beam 51 emitted from the optical irradiation device 1C or the aforementioned light transmitting device 82 of the other party engaging in optical wireless communication. The receiving position can also be described as the position where the incident beam 52 from the optical irradiation device 1C or light transmitting device 82 of the other party engaging in optical wireless communication enters the imaging optical system 10. The receiving position can also be described as the position of the light transmitting / receiving optical element 41 in a direction perpendicular to the optical axis 111c. For example, as described above, the position changing device 40C changes the receiving position of the irradiation beam 51 by moving the light transmitting / receiving optical element 41 in a direction intersecting the optical axis 111c. When the position changing device 40C moves the light transmitting / receiving optical element 41 in a direction intersecting the optical axis 111c, the optical path of the incident beam 52 from the imaging optical system 10 to the light transmitting / receiving optical element 41 changes. As the optical path from the imaging optical system 10 to the light transmitting / receiving optical element 41 changes, the receiving position of the incident beam 52 changes. The position changing device 40 may change the light receiving position of the incident beam 52 by moving the light transmitting and receiving optical element 41 as described above. Alternatively, the position changing device 40C may change the light receiving position of the incident beam 52 by moving the entire light generating device 60 as described above. It can also be said that the position changing device 40C changes the light receiving direction of the incident beam 52 by moving the light transmitting and receiving optical element 41 as described above.

[0185] The optical system 70 may be telecentric with respect to at least one of the light transmitting / receiving optical elements 41 side and the optical member 20 side. For example, if the optical system 70 is telecentric on both the light transmitting / receiving optical elements 41 side and the optical member 20 side, the position of the light transmitting / receiving optical elements 41 on the xz plane can be easily aligned with at least a part of the object to be illuminated. The light transmitting / receiving optical elements 41 side of the optical system 70 may be referred to as the position changing device 40C side of the optical system 70. The light transmitting / receiving optical elements 41 side of the optical system 70 may also be referred to as the second conjugate plane 222 side of the optical system 70. The optical member 20 side of the optical system 70 may also be referred to as the first conjugate plane 221 side of the optical system 70.

[0186] As shown in Figure 8, the optical system 70 installed between the first conjugate surface 221 and the second conjugate surface 222 may be a magnifying optical system. If the optical system 70 is a magnifying optical system, the optical system 70 forms the second conjugate surface 222 by magnifying the first conjugate surface 221 at a predetermined magnification. If the optical system 70 is a magnifying optical system, the control device 50 of the light irradiation device 1C only needs to position the transmitting and receiving photo-optical elements 41 on the second conjugate surface 222, which is magnified at a predetermined magnification, so that the incident position of the irradiation beam 51 is a desired incident position (i.e., the irradiation position of the irradiation beam 51 emitted from the imaging optical system 10 onto the object is a desired irradiation position that enables optical communication). Therefore, the control device 50 (position changing device 40C) of the light irradiation device 40C can control the irradiation position onto the object with greater precision. In other words, the position changing device 40C can be changed to a less expensive drive device with a larger positioning error. In other words, the control device 50 can be changed to a less expensive control device with a larger control error.

[0187] Furthermore, if the optical system 70 is a magnifying optical system, a wider space can be secured on the xz plane (for example, on the plane intersecting the optical axis 111c of the imaging optical system 10), thereby securing installation space on the plane perpendicular to the y-axis direction for installing the light transmitting and receiving optical elements 41 and the position changing device 40C. Furthermore, the optical system 70 is not limited to a magnifying optical system; it may also be a reducing optical system or a 1:1 optical system.

[0188] In this case, if the light irradiation device 1 does not have an optical system 70, there may not be enough space near the conjugate surface 220 of the optical element 20 for the position changing device 40 to provide a mechanism for moving the light transmitting and receiving optical element 41. As described above, according to this embodiment, by further including the optical system 70, the placement positions of the light transmitting and receiving optical elements 41 and the position changing device 40C can be moved away from the optical member 20. Therefore, space can be secured for installing the light receiving optical elements 41 and the position changing device 40C.

[0189] Furthermore, the control device 50 of the light irradiation device 1C may, similar to the control device 50 of the light irradiation device 1 in the first embodiment, control the position change device 40C for optical wireless communication with the other light irradiation device 1C based on the imaging results of at least a part of the object by the imaging device 30 (i.e., it may move the transmitting and receiving photo-optical elements 41). Furthermore, the control device 50 of the light irradiation device 1C may, similar to the control device 50 of the light irradiation device 1 of the first embodiment, control the position changing device 40C for optical wireless communication with the other light irradiation device 1 of the first embodiment based on the imaging results of at least a part of the object by the imaging device 30. Furthermore, the light irradiation device 1C is not limited to other light irradiation devices 1C as physical objects, but can also communicate via optical wireless communication with the above-mentioned light receiving device 81, light transmitting device 82, or light transmitting / receiving device 83 as physical objects. Even in this case, the control device 50 of the light irradiation device 1C may perform optical wireless communication with the light receiving device 81, light transmitting device 82, or light transmitting / receiving device 83 by performing the same processing and control as the control device 50 of the light irradiation device 1 of the first embodiment. For example, when communicating via optical wireless communication with the light receiving device 83, the control device 50 of the light irradiation device 1C may control the position change device 40C so that the irradiation beam 51 from the light irradiation device 1C is incident on the light receiving device 811, based on the position of the characteristic location of the light receiving device 81 on the image acquired by the imaging device 30 (for example, a marker placed on the light receiving device 81) and the positional relationship between the characteristic location of the light receiving device 81 and the light receiving part 811 of the light receiving device 81, as identified by the above-mentioned image processing (i.e., the light transmitting / receiving optical element 41 may be moved). Furthermore, since this would overlap with the description of the first embodiment, the explanation of the processing and control of the control device 50 of the light irradiation device 1C will be omitted.

[0190] Furthermore, instead of the optical irradiation device 1A in the optical wireless communication system 100A of the first embodiment, an optical irradiation device 1C may be used, and optical wireless communication may be performed between the optical irradiation device 1C and 0 or more light receiving devices 81, light transmitting devices 82, and light transmitting / receiving devices 83, respectively. However, since this would overlap with the description of the first embodiment, the description of the processing and control of the control device 50 of the optical irradiation device 1C in this case will be omitted. Furthermore, similar to the first embodiment, at least one of the calibration of the imaging device 30 and the calibration of the light transmitting and receiving optical element 41 may be performed. In this embodiment, at least one of the irradiation beam 51 and the incident beam 52 is not limited to light for optical wireless communication. For example, at least one of the irradiation beam 51 and the incident beam 52 may be light for optical wireless power transmission. The wavelength of the light for optical wireless power transmission may be in the infrared wavelength band, the ultraviolet wavelength band, or the visible light wavelength band. The output power of the light for optical wireless power transmission may be several watts, several tens of watts, or several kilowatts. For example, if the irradiation beam 51 is used as light for optical wireless power transmission, the light irradiation device 1C may supply power to the device to be optically wirelessly powered (for example, at least one of the light irradiation device 1C, the light receiving device 82, and the light transmitting / receiving device 83) by irradiating it with the irradiation beam 51 through the processing and control of the control device 50 described above. The light irradiation device 1C may also be referred to as a power supply device.

[0191] [Third Embodiment] Figure 9 is a schematic diagram illustrating the configuration of a light irradiation device according to the third embodiment. The light irradiation device 1D according to the third embodiment will be described with reference to this figure. The light irradiation device 1D differs from the light irradiation device 1 in that it is equipped with a position change device 40D instead of a position change device 40. The light irradiation device 1D also differs from the light irradiation device 1 in that it is equipped with a light transmitting optical element 41D instead of a light transmitting and receiving optical element 41. The light irradiation device 1D also differs from the light irradiation device 1 in that it is equipped with an imaging device 30D instead of an imaging device 30. The light irradiation device 1D also differs from the light irradiation device 1 in that it is equipped with a light concentrating optical system 71 and a collimating lens 73. The light irradiation device 1D may be provided with the above-mentioned characteristic parts. The light irradiation device 1D may be installed on the above-mentioned movable body. In the description of the light irradiation device 1D, components similar to those of the light irradiation device 1 may be denoted by the same reference numerals, and their description may be omitted. Note that the control device 50 is not shown in Figure 9. In this embodiment, the light irradiation device 1D may perform optical wireless communication.

[0192] In the above-described embodiment, the position-changing device 40 or 40C changed the irradiation position of the irradiation beam 51 emitted from the imaging optical system 10 by moving the transmitting / receiving optical element 41 on the xz plane (for example, on a plane intersecting the optical axis 111a or 111c on the conjugate plane side of the imaging optical system 10). However, a mechanism for moving on a plane leads to an increase in the size of the device, so in this embodiment, the objective is to miniaturize the device by eliminating the mechanism for moving on a plane.

[0193] The light-transmitting optical element 41D may include an optical fiber that emits the irradiation beam 51 generated by the communication board 62 toward the collimating lens 73 described later. The light-transmitting optical element 41D may also include existing optical components other than the optical fiber. Furthermore, the light-transmitting optical element 41D may consist of at least one existing optical component, as long as it can emit the irradiation beam 51 from the communication board 62 toward the collimating lens 73. For example, the light-transmitting optical element 41D may include the optical fiber 61-1 and Fresnel lens 42-1 described above. The position changing device 40D includes at least an incident angle changing member 72. The position changing device 40D changes the position of the irradiation beam 51 from the light transmitting optical element 41D (collimating lens 73) on the conjugate plane 220. In addition to the incident angle changing member 72, the position changing device 40D may also include at least one existing optical element. Furthermore, the position changing device 40D may be any other existing device capable of changing the position of the irradiation beam 51 from the light transmitting optical element 41D on the conjugate plane 220.

[0194] The focusing optical system 71 is positioned in the optical path between the light-transmitting optical element 41D and the optical member 20. The focusing optical system 71 focuses the illumination beam 51 emitted from the light-transmitting optical element 41D. Specifically, the illumination beam 51 is focused to the conjugate plane 220. Focusing to the conjugate plane 220 broadly includes focusing to the vicinity of the conjugate plane. Furthermore, the condensing optical system 71 may be located on or near the conjugate plane 220 of the imaging optical system 10. For example, as shown in Figure 9, the light-emitting end 711 on the optical member 20 side of the condensing optical system 71 may be located slightly away from the conjugate plane 220 along the direction away from the optical member 20 (positive y-axis direction). Furthermore, the condensing optical system 71 may be, for example, an fθ lens. In this case, the fθ lens may be an optical system composed of at least one optical member. Furthermore, the condensing optical system 71 does not have to be an fθ lens and may have other projection characteristics. For example, the condensing optical system 71 may be an optical system having equisolid angle projection characteristics or orthogonal projection characteristics.

[0195] The collimating lens 73 converts the irradiation beam 51 (diffuse light) emitted from the light transmitting / receiving optical element 41D into parallel light. The collimating lens 73 may be a single lens or composed of multiple lenses. The collimating lens 73 may also be composed of at least one lens and other optical components.

[0196] The incident angle changing member 72 reflects the illumination beam 51 emitted from the collimating lens 73 (i.e., the illumination beam 51 from the transmitting / receiving optical element 41D) at an arbitrary angle, thereby causing it to enter the focusing optical system 71 at an arbitrary incident angle. The incident angle changing member 72 can change the reflection angle of the incident illumination beam 51 (i.e., the exit angle from the incident angle changing member 72). The incident angle changing member 72 may also include a reflecting element, and the reflection angle of the incident illumination beam 51 (exit angle from the incident angle changing member 72) may be changed by changing the tilt angle of the reflecting element. The incident angle changing member 72 may also be a spatial light modulator such as a mirror array having a plurality of reflecting elements arranged in two dimensions, the tilt angle of each reflecting element being changeable. In this case, the incident angle changing member 72 may also be a DMD (Digital Mirror Device) as a spatial light modulator. The incident angle changing member 72 is not limited to a reflective type, but may also be an existing transmissive type spatial light modulator. Furthermore, the incident angle changing member 72 is not limited to a spatial light modulator, but may also be a galvanometer mirror (which may be called a galvanometer scanner) or a polygon mirror (which may be called a polygon scanner).

[0197] The incident angle changing member 72 changes the reflection angle of the illumination beam 51 (for example, the tilt angle of the reflecting element of the incident angle changing member 72), thereby changing the incident angle of the illumination beam 51 to the focusing optical system 71. The focusing optical system 71 focuses the incident illumination beam 51 toward the conjugate plane 220. Here, for example, if the focusing optical system 71 is an fθ lens, the focusing position on the conjugate plane 220 changes according to the incident angle of the incident illumination beam 51. Therefore, the incident angle changing member 72 changes the position of the illumination beam 51 on the conjugate plane 220 by changing the incident angle of the illumination beam 51 to the focusing optical system 71. As described above, by changing the position of the illumination beam 51 on the conjugate plane 220, the illumination position of the illumination beam 51 emitted from the imaging optical system 10 via the optical member 20 can be changed. In other words, the position changing device 40D can change the irradiation position of the irradiation beam 51 emitted from the imaging optical system 10 by changing the reflection angle of the irradiation beam 51 at the incident angle changing member 72 (for example, the tilt angle of the reflecting element of the incident angle changing member 72). Therefore, the position changing device 40D can change the irradiation position of the irradiation beam 51 emitted from the imaging optical system 10 by changing the position of the irradiation beam 51 from the light transmitting optical element 41D (light generator 6) at the conjugate plane 220.

[0198] Furthermore, as described above, the focusing optical system 71 contributes to changing the position of the irradiation beam 51 on the conjugate plane 220, and therefore can be considered part of the position changing device 40D. Similarly, the collimating lens 73 contributes to changing the position of the irradiation beam 51 on the conjugate plane 220, and therefore can be considered part of the position changing device 40D. Thus, the position changing device 40D can be considered to include at least one of the focusing optical system 71 and the collimating lens 73, in addition to the incident angle changing member 72. Furthermore, since the collimating lens 73 contributes to changing the incident angle of the irradiation beam 51 onto the focusing optical system 73, it can be considered as part of the incident angle changing member 72. Therefore, the incident angle changing member 72 can be considered to include the collimating lens 73.

[0199] Furthermore, the light-emitting end 711 of the focusing optical system 71 may be positioned on the conjugate surface 220, or it may be positioned slightly toward the optical member 20 (negative y-axis direction) from the conjugate surface 220. Even if the light-emitting end 711 of the focusing optical system 71 is positioned on the conjugate surface 220, or if it is positioned slightly toward the optical member 20 from the conjugate surface 220, the irradiation beam 51 emitted from the focusing optical system 71 can be considered to be incident on the optical member 20 via the conjugate surface 220. Therefore, even if the light-emitting end 711 of the focusing optical system 71 is positioned on the conjugate surface 220, or if it is positioned slightly toward the optical member 20 from the conjugate surface 220, the incident angle changing member 72 can be considered to change the position of the irradiation beam 51 on the conjugate surface 220 by changing the incident angle of the irradiation beam 51 to the focusing optical system 71.

[0200] The imaging device 30D is positioned near the image plane 210. The imaging device 30D can capture an image of at least a portion of an object (for example, the other party's light transmitting / receiving device 83) formed on the image plane 210, and can also receive (photoelectrically convert) an incident beam 52 from the object (for example, the other party's light transmitting / receiving device 83). The imaging device 30D may include an image sensor 32 having a plurality of pixels arranged on the imaging plane. Each of at least a portion of the plurality of pixels provided on the image sensor 32 may be a light-receiving element capable of receiving light to form an image of at least a portion of an object, and also capable of receiving an incident beam 52 from the object. In this case, among the plurality of pixels provided on the image sensor 32, the pixels (light-receiving elements) capable of receiving both light to form an image of at least a portion of an object and an incident beam 52 from the object may be called imaging pixels because they can receive light to form an image of at least a portion of an object, or they may be called light-receiving pixels because they can receive an incident beam 52 from the object. In this case, the pixels capable of receiving the incident beam 52 from the object (light-receiving pixels) receive the incident beam 51 that enters through the image plane 210. In this case, the imaging device 30D may be referred to as a light-receiving unit because it receives the incident beam 52. The pixels of the image sensor 32 of the imaging device 30D that are capable of receiving the incident beam 52 from the object (light-receiving pixels) may also be referred to as a light-receiving unit.

[0201] For example, the image sensor 32 may be an RGB sensor. In this case, the imaging device 30D may capture an image of at least a portion of the object formed on the image plane 210 by means of a protocol and algorithm for distinguishing between light for forming an image of at least a portion of the object received by the RGB sensor as the image sensor 32 and an incident beam 52 from the object, and may also receive an incident beam 52 from the object that has entered through the image plane 210. In this case, at least one of the pixels, an R pixel capable of receiving light in the red wavelength band, a G pixel capable of receiving light in the green wavelength band, and a B pixel capable of receiving light in the blue wavelength band, may be a photodetector capable of receiving both light for forming an image of at least a portion of the object and an incident beam 52 from the object. For example, if the R pixel is a photodetector capable of receiving both light for forming an image of at least a portion of the object and an incident beam 52 from the object, the G pixel and B pixel may not be able to receive the incident beam 52 from the object, but may be able to receive light for forming an image of at least a portion of the object. In this case, the incident beam 52 uses a light beam consisting of only a limited number of wavelengths in the red wavelength band.

[0202] Furthermore, the control device 50 may, based on the light reception result at the imaging device 30D (image sensor 32), identify the imaging result of at least a portion of the image of the object formed on the image plane 210 and the light reception result of the incident beam 52 from the object by means of a protocol and algorithm for identifying the light for forming an image of at least a portion of the object and the incident beam 52 from the object. The image sensor 32 does not have to be an RGB sensor. Each of the multiple pixels arranged on the image sensor 32 may be a photodetector capable of receiving light in the wavelength range from visible light to terahertz waves, a photodetector capable of receiving light in the wavelength range from visible light to millimeter waves, or a photodetector capable of receiving light in the wavelength range from visible light to infrared light.

[0203] Furthermore, some of the multiple pixels arranged on the imaging surface of the image sensor 32 may be light-receiving elements (imaging pixels) capable of receiving light to form an image of at least a part of an object, while other parts may be light-receiving elements (light-receiving pixels) capable of receiving an incident beam 52 from an object. In this case, the pixels (light-receiving pixels) capable of receiving an incident beam 52 from an object receive the incident beam 51 that enters through the image plane 210. In this case, the imaging device 30D can be considered a light-receiving unit because it receives the incident beam 52. The pixels (light-receiving pixels) on the image sensor 32 of the imaging device 30D that are capable of receiving an incident beam 52 from an object may also be referred to as the light-receiving unit. For example, the multiple pixels provided on the image sensor 32 may be in a Bayer array. One pixel from each unit pixel group in this Bayer array (for example, one G pixel from R pixels, G pixels, B pixels, and G pixels) may be used as a light-receiving element for receiving an incident beam 52 from an object. In this case, other pixels in each unit pixel group of the Bayer array (for example, R pixels, G pixels, B pixels, R pixels, B pixels, and one other G pixel among the G pixels) may be used as photodetectors capable of receiving light to form an image of at least a part of the object. Furthermore, the light-receiving element for receiving the incident beam 52 from the object is not limited to an element capable of receiving visible light (for example, the green wavelength band mentioned above), but may also be an element capable of receiving light in other wavelength bands (for example, light in the wavelength band including terahertz waves used in optical wireless communication or light in the wavelength band including infrared rays). The image sensor 32 may also be a monochrome image sensor.

[0204] The control device 50 of the light irradiation device 1D may control the position change device 40D to communicate optically with another light irradiation device 1D as an object, based on the imaging results of at least a portion of the object by the imaging device 30D (for example, the tilt angle of the reflecting element of the incident angle changing member 72 may be changed). In this case, optical communication may be performed by receiving the irradiation beam 51 from the light irradiation device 1D at the light receiving unit 831 of the other light transmitting and receiving device 83, and receiving the incident beam 52 from the other light transmitting and receiving device 83 at the imaging device 30D via the image plane 210 of the imaging optical system 10 of the light irradiation device 1D. For example, the control device 50 of the light irradiation device 1D may control the position changing device 40D so that the irradiation beam 51 from the light irradiation device 1D is incident on the light receiving unit 831, based on the position of a characteristic location of the other light transmitting / receiving device 83 on the image acquired by the imaging device 30D, which is identified by the image processing described above (for example, a marker placed on the light transmitting / receiving device 83), and the positional relationship between the characteristic location of the other light transmitting / receiving device 83 and the light receiving unit 831 (for example, the tilt angle of the reflecting element of the incident angle changing member 72 may be changed).

[0205] Furthermore, the control device 50 of the light irradiation device 1D is not limited to the processing and control described above, and at least some of the processing and control of the control device 50 of the first embodiment and the control device 50 of the second embodiment may be applied. Furthermore, the light irradiation device 1D is not limited to the light transmitting and receiving device 83 as an object, and may communicate via optical wireless communication with at least one of the light irradiation device 1 of the first embodiment, the light irradiation device 1C of the second embodiment, and the light irradiation device 1D of this embodiment. In this case, the processing and control of the control device 50 of the light irradiation device 1D may be based on the processing and control of the control device 50 of the light irradiation device 1 of the first embodiment, the control device 50 of the light irradiation device 1C of the second embodiment, and at least some of the processing and control of the control device 50 of this embodiment described above.

[0206] Furthermore, the light irradiation device 1D is not limited to the light transmitting / receiving device 83 as an object, but may also communicate via optical wireless communication with the light receiving device 81 or the light transmitting device 82 as an object. Even in this case, the control device 50 of the light irradiation device 1D may communicate via optical wireless communication with the light receiving device 81 or the light transmitting device 82 by performing at least some of the processing and control of the control device 50 of the light irradiation device 1 of the first embodiment, the control device 50 of the light irradiation device 1C of the second embodiment, and the control device 50 of this embodiment. Furthermore, in the optical wireless communication system 100A of the first embodiment, an optical irradiation device 1D may be used instead of the optical irradiation device 1A, and optical wireless communication may be transmitted between the optical irradiation device 1D and 0 or more light receiving devices 81, light transmitting devices 82, and light transmitting / receiving devices 83, respectively. Even in the above case, the control device 50 of the optical irradiation device 1D may perform optical wireless communication with 0 or more light receiving devices 81, light transmitting devices 82, and light transmitting / receiving devices 83, respectively, by executing at least some of the processing and control of the control device 50 of the optical irradiation device 1 of the first embodiment, the control device 50 of the optical irradiation device 1C of the second embodiment, and the control device 50 of this embodiment. Furthermore, the light transmitting / receiving device 83 may have the same configuration as the optical irradiation device 1, optical irradiation device 1C, or optical irradiation device 1D.

[0207] For example, when optical wireless communication is performed between an optical irradiation device 1D and a plurality of light receiving devices 81 or a plurality of light transmitting and receiving devices 83, the optical irradiation device 1D may be equipped with a plurality of communication boards 62, a plurality of optical fibers 61, a plurality of light transmitting optical elements 41D, a plurality of collimating lenses 73, and a plurality of incident angle changing members 72, depending on the number of light receiving devices 81 of the other party with which optical wireless communication is performed. In this case, the optical irradiation device 1D does not have to be equipped with a plurality of communication boards 62, and a plurality of irradiation beams may be generated from a common communication board 62 to be incident on each of the plurality of optical fibers 61. The position changing device 40D may also include a plurality of incident angle changing members 72. The control device 50 of the optical irradiation device 1D may individually change the reflection angle of the irradiation beam 51 at each incident angle changing member 72 by controlling the position changing device 40D.

[0208] For example, if the optical wireless communication system 100A includes an optical irradiation device 1D and two light transmitting and receiving devices 83 (a first light transmitting and receiving device 83-1 and a second light transmitting and receiving device 83-2), the optical irradiation device 1D may emit a first irradiation beam 51-1 generated by a first communication substrate 62-1 from the imaging optical system 10 via a first light transmitting optical system 41D-1, a first collimating lens 73-1, a first incident angle changing member 72-1, and a focusing optical system 71. Alternatively, the first incident beam 52-1 emitted from the first light transmitting and receiving device 83-1 for optical wireless communication with the optical irradiation device 1D may be received by the imaging device 30D via the imaging optical system 10. Furthermore, the light irradiation device 1D may emit the second irradiation beam 51-2 generated by the second communication board 62-2 from the imaging optical system 10 via the second light transmitting optical system 41D-2, the second collimating lens 73-2, the second incident angle changing member 72-2, and the focusing optical system 71. Alternatively, the second incident beam 52-2 emitted from the second light transmitting and receiving device 83-2 for optical wireless communication with the light irradiation device 1D may be received by the imaging device 30D via the imaging optical system 10. The position changing device 40D may include a first incident angle changing member 72-1 and a second incident angle changing member 72-2.

[0209] In this case, the light irradiation system 100A may communicate via optical wireless communication between the light irradiation device 1D and the first light transmitting and receiving device 83-1 by irradiating the first light receiving unit 831-1 of the first light transmitting and receiving device 83-1 with the first light transmitting unit 832-1 of the first light transmitting and receiving device 83-1, and receiving the first incident beam 52-1 with the imaging device 30D of the light irradiation device 1D. Alternatively, the light irradiation system 100A may communicate via optical wireless communication between the light irradiation device 1D and the second light transmitting and receiving device 83-2 by irradiating the second light receiving unit 831-2 of the second light transmitting and receiving device 83-2 with the second light transmitting unit 832-2 of the second light transmitting and receiving device 83-2, and receiving the second incident beam 52-2 with the imaging device 30D of the light irradiation device 1D. In other words, in this example, the light irradiation device 1D may send and receive information with the first light transmitting / receiving device 83-1. The light irradiation device 1D may send and receive information with the second light transmitting / receiving device 83-2. The light irradiation device 1D may simultaneously send and receive information with the first light transmitting / receiving device 83-1 and with the second light transmitting / receiving device 83-2.

[0210] The control device 50 of the light irradiation device 1D may control the position changing device 40D so that the first irradiation beam 51-1 emitted from the light irradiation device 1D is incident on the first light receiving unit 831-1, based on the position of the characteristic location of the first light transmitting / receiving device 83-1 as an object on the image acquired by the imaging device 30D, which has been identified by the image processing described above, and the positional relationship between the characteristic location of the first light transmitting / receiving device 83-1 and the first light receiving unit 831-1 of the first light transmitting / receiving device 83-1 (that is, the reflection angle of the first irradiation beam 51-1 at the first incident angle changing member 72-1 may be changed). The light irradiation device 1D may also receive the first incident beam 52-1 from the first light transmitting unit 832-1 of the first light transmitting / receiving device 83-1 at the imaging device 30D via the imaging optical system 10.

[0211] Furthermore, the control device 50 of the light irradiation device 1D may control the position changing device 40D so that the second irradiation beam 51-2 emitted from the light irradiation device 1D is incident on the second light receiving unit 831-2, based on the position of the characteristic location of the second light transmitting / receiving device 83-2 as an object on the image acquired by the imaging device 30D, which has been identified by the image processing described above, and the positional relationship between the characteristic location of the second light transmitting / receiving device 83-2 and the second light receiving unit 831-2 of the second light transmitting / receiving device 83-2 (that is, the reflection angle of the second irradiation beam 51-2 at the second incident angle changing member 72-2 may be changed). The light irradiation device 1D may also receive the second incident beam 52-2 from the second light transmitting unit 832-2 of the second light transmitting / receiving device 83-2 at the imaging device 30D via the imaging optical system 10.

[0212] Furthermore, when optical wireless communication is performed between the light irradiation device 1D and multiple light receiving devices 81 or multiple light transmitting / receiving devices 83, the light irradiation device 1D does not need to be equipped with multiple communication boards 62, multiple optical fibers 61, multiple light transmitting optical elements 41D, multiple collimating lenses 73, and multiple incident angle changing members 72. For example, the light irradiation device 1D may be equipped with a single communication board 81, a single optical fiber 61, a single light transmitting optical element 41D, a single collimating lens 73, and a single incident angle changing member 72. In this case, the single incident angle changing member 72 may be a spatial light modulator, or it may be a DMD as a spatial light modulator. If the optical wireless communication system 100A comprises an optical irradiation device 1D and two light transmitting and receiving devices 83 (a first light transmitting and receiving device 83-1 and a second light transmitting and receiving device 83-2), some of the multiple reflecting elements of a single incident angle changing member 72 (which may be referred to as the first group of reflecting elements) may be used to change the reflection angle (i.e., change the position of the first irradiation beam 51-1 on the conjugate plane 220) so that the first irradiation beam 51-1, as part of the irradiation beam 51 from the collimating lens 73, is incident on the first light receiving unit 831-1 of the first light transmitting and receiving device 83-1. Furthermore, other reflective elements (which may be referred to as the second group of reflective elements) of the multiple reflective elements of the single incident angle changing member 72 may be used to change the reflection angle (i.e., change the position of the second irradiation beam 51-2 on the conjugate plane 220) so that the second irradiation beam 51-2, which is the other part of the irradiation beam 51 from the collimating lens 73, is incident on the second light receiving unit 831-2 of the second light transmitting and receiving device 83-2.

[0213] In this case, the control device 50 of the light irradiation device 1D may control the position changing device 40D so that the first irradiation beam 51-1 emitted from the light irradiation device 1D is incident on the first light receiving unit 831-1, based on the position of the characteristic location of the first light transmitting / receiving device 83-1 on the image acquired by the imaging device 30D, which has been identified by the image processing described above, and the positional relationship between the characteristic location of the first light transmitting / receiving device 83-1 and the first light receiving unit 831-1 of the first light transmitting / receiving device 83-1 (that is, the reflection angle of the first irradiation beam 51-1 at the first reflective element group of the incident angle changing member 72 may be changed). The light irradiation device 1D may also receive the first incident beam 52-1 from the first light transmitting unit 832-1 of the first light transmitting / receiving device 83-1 with the imaging device 30D via the imaging optical system 10.

[0214] Furthermore, the control device 50 of the light irradiation device 1D may control the position changing device 40D so that the second irradiation beam 51-2 emitted from the light irradiation device 1D is incident on the second light receiving unit 831-2, based on the position of the characteristic location of the second light transmitting / receiving device 83-2 as an object on the image acquired by the imaging device 30D, which has been identified by the image processing described above, and the positional relationship between the characteristic location of the second light transmitting / receiving device 83-2 and the second light receiving unit 831-2 of the second light transmitting / receiving device 83-2 (that is, the reflection angle of the second irradiation beam 51-2 at the second reflective element group of the incident angle changing member 72 may be changed). The light irradiation device 1D may also receive the second incident beam 52-2 from the second light transmitting unit 832-2 of the second light transmitting / receiving device 83-2 with the imaging device 30D via the imaging optical system 10. Furthermore, the control device 50 of the light irradiation device 1D may identify the positions of the characteristic points of the first light transmitting / receiving device 83-1 and the position of the characteristic points of the second light transmitting / receiving device 83-2 on the same image acquired by the imaging device 30D by the image processing described above.

[0215] Furthermore, the image sensor 32 of the imaging device 30D may be configured to distinguish between the first incident beam 52-1 and the second incident beam 52-2 and receive light from them. For example, the optical conditions of the first incident beam 52-1 and the second incident beam 52-2 may be different. The optical conditions include at least one of wavelength, frequency, phase, and polarization degree. The image sensor 32 may have light-receiving elements (light-receiving pixels) arranged so that the difference in optical conditions between the first incident beam 52-1 and the second incident beam 52-2 can be distinguished. For example, if the wavelength of the first incident beam 52-1 and the wavelength of the second incident beam 52-2 are different, a light-receiving element capable of receiving light of the wavelength of the first incident beam 52-1 (for example, light in the wavelength band including terahertz waves) and a light-receiving element capable of receiving light of the wavelength of the second incident beam 52-2 (light in the wavelength band including infrared rays) may be arranged on the imaging surface as light-receiving pixels. Furthermore, a photodetector capable of receiving light of the wavelength of the first incident beam 52-1 does not need to be able to receive light of the wavelength of the second incident beam 52-2. Furthermore, a photodetector capable of receiving light of the wavelength of the second incident beam 52-2 does not need to be able to receive light of the wavelength of the first incident beam 52-1. The control device 50 of the light irradiation device 1D may distinguish between the first incident beam 52-1 and the second incident beam 52-2 based on the light reception results of the imaging device 30D (image sensor 32) described above.

[0216] Furthermore, the control device 50 of the light irradiation device 1D may identify the first light transmitting / receiving device 83-1 and the second light transmitting / receiving device 83-2 and perform optical wireless communication. For example, the control device 50 may identify the first light transmitting / receiving device 83-1 and the second light transmitting / receiving device 83-2 based on the image acquired by the imaging device 30D. In this case, feature locations that allow the feature locations of the first light transmitting / receiving device 83-1 and the feature locations of the second light transmitting / receiving device 83-2 to be distinguished on the image acquired by the imaging device 30D may be provided on the first light transmitting / receiving device 83-1 and the second light transmitting / receiving device 83-2. For example, the shape of the marker as a feature location of the first light transmitting / receiving device 83-1 and the marker as a feature location of the second light transmitting / receiving device 83-2 may be different. In this case, the control device 50 may identify the first light-receiving device 83-1 and the second light-receiving device 83-2 based on the shape of the marker of the first light-receiving device 83-1 and the shape of the marker of the second light-receiving device 83-2 on the image acquired by the imaging device 30D.

[0217] Furthermore, not limited to differences in characteristic features, the control device 50 may also distinguish between the first light-receiving device 83-1 and the second light-receiving device 83-2 based on the light reception results of the first incident beam 52-1 from the first light-receiving device 83-1 and the second incident beam 52-2 from the second light-receiving device 83-2 by the imaging device 30D. In this case, incident beams that can distinguish between the first incident beam 52-1 from the first light-receiving device 83-1 and the second incident beam 52-2 from the second light-receiving device 83-2 may be emitted from each of the first light-receiving device 83-1 and the second light-receiving device 83-2. For example, as described above, the light conditions of the first incident beam 52-1 and the second incident beam 52-2 may be different. The control device 50 may distinguish between the first light-receiving device 83-1 and the second light-receiving device 83-2 based on the difference in the optical conditions (for example, the difference in wavelength as described above) between the first incident beam 52-1 from the first light-receiving device 83-1 and the second incident beam 52-2 from the second light-receiving device 83-2, which are received by the imaging device 30D.

[0218] Furthermore, calibration of the imaging device 30D may be performed in the same manner as in the first embodiment. Calibration of the incident angle changing member 72 may also be performed. In the calibration of the incident angle changing member 72, a correspondence may be made between the reflection angle of the irradiation beam 51 at the incident angle changing member 72 (the tilt angle of the reflecting element of the incident angle changing member 72) and its position on the image acquired by the imaging device 30D. The correspondence between the reflection angle of the irradiation beam 51 at the incident angle changing member 72 and its position on the image acquired by the imaging device 30D may be performed, for example, using the reflective surface described above.

[0219] For example, the light irradiation device 1D irradiates light from the light transmitting optical element 41D toward the reflective surface via the incident angle changing member 72, the focusing optical system 71, the optical element 20, and the imaging optical system 10, and the imaging device 30D receives the light reflected from the reflective surface by the light irradiated toward the reflective surface from the imaging optical system 10, thereby establishing a correspondence between the reflection angle of the irradiation beam 51 at the incident angle changing member 72 and its position on the image acquired by the imaging device 30D. As described above, when the reflection angle of the irradiation beam 51 at the incident angle changing member 72 (the tilt angle of the reflecting element of the incident angle changing member 72) changes, the irradiation position (irradiation direction) of the light emitted from the imaging optical system 10 changes. Therefore, when the reflection angle of the irradiation beam 51 at the incident angle changing member 72 changes, the reflection position on the reflective surface also changes, and thus the incident position of the reflected light on the imaging device 30D (the imaging surface of the image sensor 32) also changes (that is, the position of the reflected light on the image acquired by the imaging device 30D also changes). The light irradiation device 1D can also be said to perform calibration of the incident angle changing member 72 based on the reflection angle of the irradiation beam 51 at the incident angle changing member 72 and the position of the reflected light on the image acquired by the imaging device 30D. The calibration of the incident angle changing member 72 may also be referred to as calibration between the incident angle changing member 72 and the imaging device 30D, or calibration of the position changing device 40D, or calibration between the position changing device 40D and the imaging device 30D.

[0220] Furthermore, the light irradiation device 1D may include an optical system in the optical path between the focusing optical system 71 and the incident angle changing member 72. This optical system may be one in which the pupil of the focusing optical system 71 and the incident angle changing member 72 are conjugate. For example, if the incident angle changing member 72 is a reflective type spatial light modulator such as a DMD or a galvanometer mirror, this optical system may be one in which the pupil of the focusing optical system 71 and the reflective surface of the reflective type spatial light modulator such as a DMD or a galvanometer mirror are conjugate. Furthermore, this optical system may include at least one existing optical component.

[0221] As described above, according to this embodiment, by providing a focusing optical system 71, the irradiation beam 51 emitted from the light emission section of the light generator 60 is focused, and by providing an incident angle changing member 72, the incident angle of the irradiation beam 51 to the focusing optical system 71 is changed, thereby changing the position of the irradiation beam 51 on the conjugate plane 220 (i.e., changing the irradiation position of the irradiation beam 51 emitted from the imaging optical system 10). Therefore, according to this embodiment, it is not necessary to move the transmitting and receiving optical element 41 on the xz plane (for example, on a plane intersecting the optical axis 111a or 111c on the conjugate plane 220 side of the imaging optical system 10). Thus, according to this embodiment, the device can be miniaturized. Furthermore, according to this embodiment, it is not necessary to move the transmitting and receiving optical element 41 on the xz plane, so the irradiation position of the irradiation beam 51 can be changed at high speed.

[0222] Furthermore, according to the embodiment described above, the imaging device 30D has a plurality of imaging pixels for imaging at least a portion of the image of an object, and at least a portion of the plurality of imaging pixels are capable of receiving the incident beam 52. The imaging pixels capable of receiving the incident beam 52 receive the incident beam 52 that is incident through the image plane 210. Therefore, according to this embodiment, it is not necessary to move the light transmitting and receiving optical element 41 on the xz plane (for example, on a plane intersecting the optical axis 111a or 111c on the conjugate plane 220 side of the imaging optical system 10) in order to receive the incident beam 52. Thus, according to this embodiment, the device can be miniaturized. Also, according to this embodiment, it is not necessary to move the light transmitting and receiving optical element 41 on the xz plane, so the incident beam 52 can be received at high speed.

[0223] Furthermore, according to the embodiment described above, the imaging device 30D has a plurality of imaging pixels for imaging at least a portion of the image of an object, and a light-receiving pixel that, unlike the imaging pixels, acts as a light-receiving unit for receiving the incident beam 52. The light-receiving pixel receives the incident beam 52 that is incident through the image plane 210. Therefore, according to this embodiment, it is not necessary to move the light-transmitting optical element 41 on the xz plane in order to receive the incident beam 52. Thus, according to this embodiment, the device can be miniaturized. Also, according to this embodiment, since it is not necessary to move the light-transmitting optical element 41 on the xz plane, the incident beam 52 can be received at high speed.

[0224] [Fourth Embodiment] Next, the light irradiation device 1E according to the fourth embodiment will be described with reference to Figures 10 to 12. Figure 10 is a schematic diagram illustrating the configuration of a light irradiation device according to the fourth embodiment. First, the schematic configuration of the light irradiation device 1E according to the fourth embodiment will be described with reference to this figure. The light irradiation device 1E differs from the light irradiation device 1D in that it is equipped with a transmitting and receiving light optical element 41E instead of a transmitting light optical element 41D. Also, the light irradiation device 1E is equipped with an imaging device 30E instead of an imaging device 30D. The light irradiation device 1E may be provided with the aforementioned characteristic parts. The light irradiation device 1E may be installed on the movable body described above. In the description of the light irradiation device 1E, components similar to those of the light irradiation device 1D may be denoted by the same reference numerals and their description may be omitted. Note that the control device 50 is not shown in Figure 10.

[0225] In this embodiment, the light irradiation device 1E may perform optical wireless communication.

[0226] The light transmitting and receiving optical element 41E comprises at least a light transmitting optical system 412 and a light receiving optical system 413. The light transmitting and receiving optical element 41E may also be referred to as a light emission unit, a light receiving unit, or a light transmitting and receiving unit. The light-transmitting optical system 412 may include an optical fiber that emits the illumination beam 51 generated by the communication board 62 toward the collimating lens 73. The light-transmitting optical system 412 may also include existing optical components other than the optical fiber. Furthermore, the light-transmitting optical system 412 may consist of at least one existing optical component, as long as it can emit the illumination beam 51 from the communication board 62 toward the collimating lens 73. The light-transmitting optical system 412 may be the same as the light-transmitting optical element 41D described above. The light-transmitting optical system 412 may also be referred to as the light-transmitting optical element or the light-emitting section. For example, the light-transmitting optical system 412 may include the optical fiber 61-1 and Fresnel lens 42-1 described above.

[0227] The light-receiving optical system 413 may include an optical fiber that emits the incident beam 52, which is incident via the imaging optical system 10, the focusing optical system 71, the incident angle changing member 72, and the collimating lens 73, toward the communication substrate 62. The light-receiving optical system 413 may also include existing optical components other than the optical fiber. Furthermore, the light-receiving optical system 413 may consist of at least one existing optical component, as long as it can emit the incident beam 52 from the collimating lens 73 toward the communication substrate 62. The light-receiving optical system 413 may also be referred to as a light-receiving optical element or light-receiving unit. For example, the light-receiving optical system 413 may include the optical fiber 61-2 and Fresnel lens 42-2 described above.

[0228] The imaging device 30E, like the imaging device 30 described above, is positioned near the image plane 210 of the imaging optical system 10 and captures an image of at least a portion of an object formed on the image plane 210. The imaging device 30E, like the image sensor 31 of the imaging device 30, includes an image sensor 33 having a plurality of pixels arranged on its imaging surface. It can also be said that the image sensor 33 captures a reduced image of at least a portion of an object formed on the image plane 210. For example, the imaging surface of the image sensor 33 may be positioned on the image plane 210 of the imaging optical system 10. Alternatively, the imaging surface of the image sensor 33 does not have to be positioned on the image plane 210 of the imaging optical system 10, but may be positioned near the image plane 210. The image sensor 33 may be an image sensor capable of outputting color image data (e.g., an RGB image sensor) or an image sensor capable of outputting monochrome image data (e.g., a monochrome image sensor).

[0229] The position changing device 40E includes at least an incident angle changing member 72. The position changing device 40E changes the position of the irradiation beam 51 from the light transmitting optical system 412 (collimating lens 73) on the conjugate plane 220. Alternatively, the position changing device 40E can be said to change the position of the incident beam 52 from the optical member 20 that is incident on the light receiving optical system 413 on the conjugate plane 220. Furthermore, the position changing device 40E may include at least one existing optical component in addition to the incident angle changing member 72. Furthermore, the position changing device 40E may be any other existing device capable of changing the position of the irradiation beam 51 incident from the light transmitting optical system 412 through the collimating lens 73 on the conjugate plane 220. Furthermore, the position changing device 40E may be the same as the position changing device 40D.

[0230] The incident angle changing member 72 may be, for example, a spatial light modulator such as a mirror array having a plurality of two-dimensionally arranged reflective elements and in which the tilt angle of each reflective element can be changed. In this case, the incident angle changing member 72 may be a DMD (Digital Mirror Device) as a spatial light modulator. The incident angle changing member 72 is not limited to a reflective type, but may also be an existing transmissive type spatial light modulator. Furthermore, the incident angle changing member 72 is not limited to a spatial light modulator, but may also be a galvanometer mirror (which may also be called a galvanometer scanner) or a polygon mirror (which may also be called a polygon scanner).

[0231] The irradiation beam 51 from the light transmitting optical system 413 is converted into parallel light by the collimating lens 73 and incident on the incident angle changing member 72. The irradiation beam 51 incident on the incident angle changing member 72 is emitted towards an object (for example, the other light transmitting and receiving device 83) via the focusing optical system 71, the optical member 20, and the imaging optical system 10. The incident angle changing member 72 may cause the irradiation beam 51 from the light transmitting optical system 412 to enter the focusing optical system 71 at any incident angle by reflecting it at any angle. The incident angle changing member 72 can change the reflection angle of the incident irradiation beam 51 (for example, the tilt angle of the reflecting element of the incident angle changing member 72).

[0232] The incident angle changing member 72 changes the reflection angle of the irradiation beam 51, thereby changing the incident angle of the irradiation beam 51 to the focusing optical system 71. The focusing optical system 71 focuses the incident irradiation beam 51 toward the conjugate plane 220. Here, for example, if the focusing optical system 71 is an fθ lens, the focusing position on the conjugate plane 220 changes according to the incident angle of the incident irradiation beam 51. Therefore, the control device 50 changes the position of the irradiation beam 51 on the conjugate plane 220 by changing the incident angle of the irradiation beam 51 to the focusing optical system 71. Furthermore, the setting of the irradiation position of the irradiation beam 51 from the light transmitting optical system 412 onto an object by the control device 50 (i.e., control of the position changing device 40E) is the same as the setting of the irradiation position of the irradiation beam 52 from the light transmitting and receiving optical element 41D onto an object by the control device 50 (i.e., control of the position changing device 40D) in the third embodiment described above, so the explanation is omitted.

[0233] An incident beam 52, which enters the imaging optical system 10 from an object (for example, the other party's light transmitting / receiving device 83), enters the incident angle changing member 72 via the optical member 20 and the focusing optical system 71. The incident angle changing member 72 reflects the incident beam 52 toward the collimating lens 73. The collimating lens 73 focuses the incident beam 52 from the incident angle changing member 72 toward the light receiving optical system 412. The light focused toward the light receiving optical system 412 is received by the communication substrate 62. By changing the reflection angle of the incident beam 52 with the incident angle changing member 72, the incident beam 52 that has passed through any position on the conjugate plane 220 can be selectively directed toward the photoreceiving optical system 413 (communication board 62). Furthermore, by changing the reflection angle of the incident beam 52 with the incident angle changing member 72, it can be said that the optical path of the incident beam 52 entering the photoreceiving optical system 413 (communication board 62) from the conjugate plane 220 (optical member 20) via the incident angle changing member 72 can be selected.

[0234] The incident angle changing member 72 may pass through any position on the conjugate surface 220 and reflect the incident beam 52 that has entered through the focusing optical system 71 at any angle, thereby directing it toward the light receiving optical system 413 (communication substrate 62). When the focusing position of the incident beam 52 at the conjugate plane 220 changes, the incident position of the incident beam 52 into the focusing optical system 71 changes. Here, if the focusing optical system 71 is an fθ lens, when the incident position of the incident beam 52 into the focusing optical system 71 changes, the exit angle of the incident beam 52 from the focusing optical system 71 changes. When the exit angle of the incident beam 52 from the focusing optical system 71 changes, the incident angle of the incident beam 52 into the incident angle changing member 72 changes. The control device 50 controls the position changing device 40E (incident angle changing member 72) so that the incident beam 52 is incident on the light receiving optical system 413 (communication board 62) via the collimating lens 73, in accordance with the incident angle of the incident beam 52 into the incident angle changing member 72, that is, it sets the reflection angle of the incident beam 52 (for example, the tilt angle of the reflecting element of the incident angle changing member 72).

[0235] Furthermore, depending on the positional relationship between the light irradiation device 1E and the object (for example, the other light transmitting / receiving device 83), the incident position of the incident beam 52 from the object to the imaging optical system 10 (for example, the optical element closest to the object in the imaging optical system 10), i.e., the light receiving position of the incident beam 52, changes, which in turn changes the focusing position of the incident beam 52 on the conjugate plane 220. Therefore, the position changing device 40E (incidence angle changing member 72) can cause the incident beam 52, which has been incident at any position in the imaging optical system 10, to be incident on the light receiving optical system 413 (communication board 62) by changing the reflection angle of the incident beam 52 (for example, the tilt angle of the reflecting element of the incident angle changing member 72). It can also be said that the position changing device 40E changes the light receiving position of the incident beam 52 that is incident on the light receiving optical system 413 (communication board 62) by changing the reflection angle of the incident beam 52 (for example, the tilt angle of the reflecting element of the incident angle changing member 72). Furthermore, as described above, at least one of the focusing optical system 71 and the collimating lens 73 contributes to changing the position of the irradiation beam 51 on the conjugate plane 220, and can therefore be considered part of the position changing device 40E.

[0236] For example, the incident angle changing member 72 may be a DMD (Digital Mirror Device) having a plurality of reflecting elements arranged in two dimensions and capable of individually changing the tilt angle of each reflecting element. Here, the incident angle changing member 72 can be said to have a light reflection region capable of reflecting incident light with a plurality of reflecting elements arranged in two dimensions. Figure 11 is a schematic diagram illustrating the case in which the light reflection region of the incident angle changing member 72 according to the fourth embodiment is divided into a light transmission region 4141 that reflects at least a portion of the irradiation beam 51 from the light transmission optical system 412 toward the light collection optical system 71, and a light receiving region 4142 that reflects at least a portion of the incident beam 52 from the light collection optical system 71 toward the light receiving optical system 413.

[0237] Referring to the same diagram, we will now explain the separation of light reception and light transmission. Multiple reflective elements of the incident angle changing member 72 corresponding to the light transmitting area 4141 may be used to change the reflection angle (i.e., change the position of the irradiation beam 51 on the conjugate plane 220) so that the irradiation beam 51 from the light transmitting optical system 412 is incident on an object (e.g., the other light irradiation device 1E), and other multiple reflective elements of the incident angle changing member 72 corresponding to the light receiving area 4142 may be used to change the reflection angle so that the incident beam 52 from the focusing optical system 71 is incident on the light receiving optical system 413 (communication board 62).

[0238] For example, when the light irradiation device 1E and the light transmitting / receiving device 83 communicate via optical wireless communication, the control device 50, for example, uses the image processing described above to identify the position of a feature location on the light transmitting / receiving device 83 (for example, a marker placed on the light transmitting / receiving device 83) on the image acquired by the imaging device 30E. Based on the position of the identified feature location on the image and the positional relationship between the light receiving unit 831 of the light transmitting / receiving device 83, which is the target to be irradiated with the irradiation beam 51, and the feature location, the control device 50 may control the position changing device 40E so that the irradiation beam 51 emitted from the light irradiation device 1E is incident on the light receiving unit 831 (that is, the tilt angle of the multiple reflective elements of the incident angle changing member 72 corresponding to the light transmitting area 4141). The control device 50 may control the position change device 40E so that the incident beam 52 emitted from the light transmitting unit 832 is incident on the light receiving optical system 413 (communication board 62), based on the position of the feature location identified as described above on the image and the positional relationship between the feature location and the light transmitting unit 832 of the light transmitting / receiving device 83 from which the incident beam 52 is emitted. (That is, it may set the tilt angle of the other multiple reflective elements of the incident angle changing member 72 that correspond to the light receiving area 4142.) Note that the feature location of the light transmitting / receiving device 83 used when controlling the position change device 40E so that the irradiation beam 51 emitted from the irradiation device 1E is incident on the light receiving unit 831 may be different from the feature location of the light transmitting / receiving device 40E used when controlling the position change device 40E so that the incident beam 52 emitted from the light transmitting unit 832 is incident on the light receiving optical system 413. For example, each feature location may be a different feature location (for example, a mark of a different shape or color) located on the light transmitting / receiving device 83.

[0239] In the above case, it is not limited to the case where the light receiving unit 831 and the light transmitting unit 832 of the light transmitting / receiving device 83 are adjacent or in close proximity, but even if they are arranged far apart, the incident beam 52 from the light transmitting unit 832 can be received by the light receiving optical system 413 (communication board 62) while the irradiation beam 51 is incident on the light receiving unit 831. Furthermore, optical wireless communication can be performed not only with the light transmitting / receiving device 83, but also with the light receiving device 81 and the light transmitting device 82 described above. In other words, the incident beam 51 from the light transmitting unit 821 of the light transmitting device 82 can be received by the light receiving optical system 413 (communication board 62) while the irradiation beam 51 is incident on the light receiving unit 811 of the light receiving device 81.

[0240] Furthermore, as shown in Figure 12, the light transmitting and receiving optical element 41E may be positioned at the defocus position 732. For example, the end of the light transmitting and receiving optical element 41E may be positioned at the defocus position 732. For example, the optical output end of the optical fiber in the light transmitting optical system 412 of the light transmitting optical element 41E (the output end of the optical fiber that emits the irradiation beam 51 to the collimating lens 73), and the optical receiving end of the optical fiber in the light receiving optical system 413 of the light transmitting and receiving optical element 41E (the optical fiber that receives the incident beam 52 from the collimating lens 73) may be positioned at the defocus position 732. The light transmitting and receiving optical element 41E may be positioned at a defocus position 732 located further in the positive x-axis direction than the focus position 731 on the side of the light transmitting and receiving optical element 41E from the collimating lens 73. Alternatively, the light transmitting and receiving optical element 41E may be positioned at a defocus position located in the negative x-axis direction from the focus position 731. The focus position 731 may also be referred to as the focal position of the collimating lens 73. The focus position 731 may also be referred to as the focus position of the light collecting optical system 71.

[0241] Furthermore, depending on the light distribution of the irradiation beam 51 emitted from the light transmitting optical system 412 and the light distribution of the incident beam 52 incident on the light receiving optical system 413, a portion of the optical path of the irradiation beam 51 and a portion of the optical path of the incident beam 52 may overlap in the light irradiation device 1E. In this case, it is not possible to distinguish and change the reflection angle of the irradiation beam 51 and the reflection angle of the incident beam 52 using the multiple reflective elements corresponding to the light transmitting region 4141 and the multiple reflective elements corresponding to the light receiving region 4142. Therefore, an optical element that adjusts the light distribution of the irradiation beam 51 from the light transmitting optical system 412 may be provided on the optical path between the light transmitting optical system 412 and the collimating lens 73 so that a portion of the optical path of the irradiation beam 51 and a portion of the optical path of the incident beam 52 do not overlap. This optical element may be a prism. For example, a prism with an apex angle in the positive y-axis direction (for example, a triangular prism) may be placed on the optical path between the light transmitting optical system 412 and the collimating lens 73. To prevent the optical path of the irradiation beam 51 from overlapping with the optical path of the incident beam 52, an optical element that adjusts the light distribution of the incident beam 52 entering the light-receiving optical system 413 may be provided in the optical path between the light-receiving optical system 413 and the collimating lens 73. This optical element may be a prism. For example, a prism with an apex angle in the negative y-axis direction (e.g., a triangular prism) may be placed in the optical path between the light-receiving optical system 413 and the collimating lens 73.

[0242] Furthermore, the incident angle changing member 72 is not limited to a spatial light modulation element, but may also be a galvanometer mirror or a polygon mirror. Furthermore, the light irradiation device 1E may include an optical system in the optical path between the focusing optical system 71 and the incident angle changing member 72. This optical system may be one in which the pupil of the focusing optical system 71 and the incident angle changing member 72 are conjugate. For example, if the incident angle changing member 72 is a reflective type spatial light modulator such as a DMD or a galvanometer mirror, this optical system may be one in which the pupil of the focusing optical system 71 and the reflective surface of the reflective type spatial light modulator such as a DMD or a galvanometer mirror are conjugate. Furthermore, this optical system may include at least one existing optical component.

[0243] As described above, according to this embodiment, by providing an incident angle changing member 72, the incident angle of the irradiation beam 51 to the focusing optical system 71 is changed, and by changing the incident angle of the irradiation beam 51 to the focusing optical system 71, the position of the irradiation beam 51 on the conjugate plane 220 is changed (i.e., the irradiation position of the irradiation beam 51 emitted from the imaging optical system 10 is changed). Therefore, according to this embodiment, it is not necessary to move the transmitting and receiving optical element 41 on the xz plane (for example, on a plane intersecting the optical axis 111a or 111c on the conjugate plane 220 side of the imaging optical system 10). Thus, according to this embodiment, the device can be miniaturized. Furthermore, according to this embodiment, it is not necessary to move the transmitting and receiving optical element 41 on the xz plane, so the irradiation position of the irradiation beam 51 can be changed at high speed.

[0244] As described above, according to this embodiment, by providing an incident angle changing member 72, the reflection angle of the incident beam 52 incident from the focusing optical system 71 at a predetermined angle is changed and incident onto the light receiving optical system 413 (communication substrate 62). Therefore, according to this embodiment, it is not necessary to move the light transmitting and receiving optical element 41 on the xz plane (for example, on a plane intersecting the optical axis 111a or 111c on the conjugate plane 220 side of the imaging optical system 10). Thus, according to this embodiment, the device can be miniaturized. Furthermore, according to this embodiment, it is not necessary to move the light transmitting and receiving optical element 41 on the xz plane, so the light receiving position of the incident beam 52 can be changed at high speed.

[0245] In this embodiment, at least one of the irradiation beam 51 and the incident beam 52 is not limited to light for optical wireless communication. For example, at least one of the irradiation beam 51 and the incident beam 52 may be light for optical wireless power transmission. The wavelength of the light for optical wireless power transmission may be in the infrared wavelength band, the ultraviolet wavelength band, or the visible light wavelength band. The output power of the light for optical wireless power transmission may be several watts, several tens of watts, or several kilowatts. For example, if the irradiation beam 51 is used as light for optical wireless power transmission, the light irradiation device 1D may supply power to the device to be optically wirelessly powered (for example, at least one of the light irradiation device 1D, the light receiving device 82, and the light transmitting / receiving device 83) by irradiating it with the light through the processing and control of the control device 50 described above. The light irradiation device 1D may also be referred to as a power supply device.

[0246] [Fifth Embodiment] Figure 13 is a schematic diagram illustrating a light irradiation device according to the fifth embodiment. The light irradiation device 1F according to the fifth embodiment will be described with reference to Figure 13. The light irradiation device 1F differs from the light irradiation device 1D of the third embodiment in that it is equipped with a light transmitting optical element 41F instead of the light transmitting optical element 41D of the light irradiation device 1D. Furthermore, the light irradiation device 1F differs from the light irradiation device 1D in that it is equipped with a collimating lens 73F. The light irradiation device 1F may also be provided with the above-mentioned characteristic parts. The light irradiation device 1F may be installed on the movable body described above. In the description of the light irradiation device 1F, components with the same configuration as those in the light irradiation device 1D may be denoted by the same reference numerals, thus omitting further explanation. Note that the control device 50 is not shown in Figure 13.

[0247] In this embodiment, the light irradiation device 1F may perform optical wireless communication. For example, the light irradiation device 1F may perform optical wireless communication with a plurality of light receiving devices 81, a plurality of light transmitting devices 82, or a plurality of optical transceiver devices 83 as objects. Note that the light irradiation device 1F may perform optical wireless communication with at least two types of devices out of the three types of devices: the optical transceiver device 83, the light transmitting device 82, and the optical transceiver device 83. Note that the light irradiation device 1F may perform optical wireless communication with a plurality of light irradiation devices 1, a plurality of light irradiation devices 1C, a plurality of light irradiation devices 1D, or a plurality of light irradiation devices 1E as objects. Note that the light irradiation device 1F may perform optical wireless communication with at least two types of devices out of the four types of devices: the light irradiation device 1, the light irradiation device 1C, the light irradiation device 1D, and the light irradiation device 1E. Note that optical wireless communication may be performed with a plurality of devices included in the optical wireless communication system 100A by using the light irradiation device 1F instead of the light irradiation device 1A of the optical wireless communication system 100A in the first embodiment.

[0248] The light-transmitting optical element 41F may include multiple optical fibers that emit each irradiation beam 51, which is generated in the communication board 62 and distributed by a distributor (not shown), toward the corresponding collimating lenses 73F. For example, the light-transmitting optical element 41F may include three light-transmitting optical elements (first light-transmitting optical element 415-1, second light-transmitting optical element 415-2, and third light-transmitting optical element 415-3), as shown in Figure 13. The light-transmitting optical element 41F may also include existing optical components in addition to multiple optical fibers. The light-transmitting optical element 41F may consist of at least one existing optical component, as long as it can emit each of the multiple irradiation beams 51 distributed from the communication board 62 toward the corresponding collimating lenses 73F. The light-transmitting optical element 41F may include, for example, multiple of the above-mentioned optical fibers 61-1 and multiple of the above-mentioned Fresnel lenses 42-1. Furthermore, one optical fiber (and / or optical component) of the light-transmitting optical element 41F can also be considered as the light-transmitting optical element 41D of the third embodiment. In other words, the light-transmitting optical element 41F can also be considered as including multiple light-transmitting optical elements 41D. Furthermore, the communication board 62 provided in the light irradiation device 1F is not limited to one, but may be multiple. In this case, the light irradiation device 1F may be provided with a communication board 62 corresponding to each of the multiple optical fibers of the light-transmitting optical element 41F. In other words, the light irradiation device 1F may be provided with the same number of communication boards 62 as the number of multiple optical fibers of the light-transmitting optical element 41F. In this case, the communication beam 51 generated by each communication board 62 may be emitted towards the collimating lens 73F through each optical fiber of the light-transmitting optical element 41F.

[0249] The collimating lens 73F converts each of the irradiation beams 51 emitted from the light transmitting optical element 41F into parallel light. For example, the collimating lens 73F includes a plurality of collimating lenses that convert each of the irradiation beams 51 emitted from the light transmitting optical element 41F into parallel light. For example, as shown in FIG. 13, the collimating lens 73F may include three collimating lenses (the first collimating lens 73-1, the second collimating lens 73-2, and the third collimating lens 73-3). Note that the collimating lens 73F may include existing optical members in addition to the plurality of collimating lenses. Note that one collimating lens of the collimating lens 73F can also be regarded as the collimating lens 73 of the third embodiment. That is, the collimating lens 73F can also be regarded as including a plurality of collimating lenses 73.

[0250] For example, as shown in FIG. 13, the collimating lens 73-1 may convert the light emitted from the first light transmitting optical element 415-1 into parallel light, the collimating lens 73-2 may convert the light emitted from the second light transmitting optical element 415-2 into parallel light, and the collimating lens 73-3 may convert the light emitted from the third light transmitting optical element 415-3 into parallel light. Note that the communication substrate 62 may be referred to as a light source. Note that the communication substrate 62 and the light transmitting optical element 41F can also be regarded as a light source. Note that the communication substrate 62, the light transmitting optical element 41F, and the collimating lens 73F can be regarded as a light source.

[0251] The imaging device 30 separately identifies and independently receives a plurality of incident beams 52 incident on the imaging optical system 10. The incident angle changing member 72 may be, for example, a spatial light modulator such as a mirror array having a plurality of reflection elements arranged two-dimensionally and capable of changing the inclination angle of each reflection element. In this case, the incident angle changing member 72 may be a DMD (Digital Mirror Device) as a spatial light modulator. The incident angle changing member 72 is not limited to the reflection type and may be an existing transmission type spatial light modulator. Here, we will describe the case in which the light irradiation device 1F communicates via optical wireless communication with three light transmitting and receiving devices 83 (first light transmitting and receiving device 83-1, second light transmitting and receiving device 83-2, and third light transmitting and receiving device 83-3). In this case, the light irradiation device 1F may include three collimating lenses (first collimating lens 73-1, second collimating lens 73-2, and third collimating lens 73-3) and three light transmitting optical elements (first light transmitting optical element 415-1, second light transmitting optical element 415-2, and third light transmitting element 415-3). Furthermore, the light irradiation device 1F may be equipped with three communication boards (first communication board 62-1, second communication board 62-2, and third communication board 62-3) that generate irradiation beams 51 (first irradiation beam 51-1, second irradiation beam 51-2, and third irradiation beam 51-3) that are incident on each of the three light transmitting optical elements. The incident angle changing member 72 may be a DMD (Digital Mirror Device). Here, at least some of the multiple reflective elements of the incident angle changing member 72 (which may be referred to as the first group of reflective elements) may be used to change the reflection angle so that the first irradiation beam 51-1 from the first collimating lens 73-1 is incident on the first light receiving unit 831-1 of the first light transmitting and receiving device 83-1 (i.e., to change the position of the irradiation beam 51 on the conjugate plane 220). At least some of the other multiple reflective elements of the incident angle changing member 72 (which may be referred to as the second group of reflective elements, different from the first group of reflective elements) may be used to change the reflection angle so that the second irradiation beam 51-2 from the second collimating lens 73-2 is incident on the second light receiving unit 831-2 of the second light transmitting and receiving device 83-2. At least some of the other reflective elements of the incident angle changing member 72 (which may be referred to as a third group of reflective elements different from the first and second groups of reflective elements) may be used to change the reflection angle so that the third irradiation beam 51-3 from the third collimating lens 73-3 is incident on the third light receiving unit 831-3 of the third light transmitting and receiving device 83-3.

[0252] The light irradiation device 1F may emit the first irradiation beam 51-1 generated by the first communication board 62-1 from the imaging optical system 10 via the first light transmitting optical element 415-1, the first collimating lens 73-1, the first group of reflective elements of the incident angle changing member 72, and the focusing optical system 71, or the first incident beam 52-1 emitted from the first light transmitting / receiving device 83-1 may be received by the imaging device 30D via the imaging optical system 10. Alternatively, the light irradiation device 1F may emit the second irradiation beam 51-2 generated by the second communication board 62-2 from the imaging optical system 10 via the second light transmitting optical...

Claims

[Claim 1] A light irradiation device that irradiates an object with an irradiation beam from a light generator, Imaging optical system, An optical member that emits light incident through the imaging optical system toward the image plane of the imaging optical system, and emits the irradiation beam from the light generator incident through a conjugate plane conjugate to the image plane toward the imaging optical system, An imaging device that captures at least a portion of the image of the object formed on the image plane by the imaging optical system, A position changing device that changes the position of the irradiation beam emitted from the imaging optical system by changing the position of the conjugate plane of the irradiation beam from the light generator, A control device that controls the position changing device based on the imaging results of the imaging device, Equipped with, The control device controls the position changing device based on the imaging results of the imaging device to irradiate at least a portion of the object with the irradiation beam emitted from the imaging optical system.

Images