Communication device and communication system

Abstract

To provide a communication device and the like capable of establishing spatial optical communication using a spatial optical signal with a communication target disposed in any direction.SOLUTION: A communication device includes: a transceiver in which a ball lens, a light receiver having a light receiving axis passing through the center of the ball lens, and a light transmitter having a light transmitting axis parallel to the light receiving axis are integrated; and a rotation mechanism that rotatably supports the transceiver along a circular orbit in a horizontal plane and a vertical plane centered on the ball lens.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a communication device and a communication system. [Background technology]

[0002] In spatial optical communication using signal light propagating through space (hereinafter also referred to as spatial optical signal), unless the positions of the light transmitter and receiver are adjusted accurately, stable communication with the communication target cannot be performed. However, it is difficult to accurately match the transmission direction and reception direction of the spatial optical signal. If the transmission direction and reception direction of the spatial optical signal can be accurately matched, it becomes easier to establish spatial optical communication using the spatial optical signal with any communication target.

[0003] Patent Document 1 discloses an optical communication device that uses laser light to communicate between spatially separated points. The optical communication device in Patent Document 1 has an angle correction device, an emitted optical axis correction device, and a light-receiving angle detection device. The angle correction device corrects the orientation of the light-receiving system. The light-receiving angle detection device detects angle errors that cannot be corrected by the angle correction device. The light-receiving angle detection device controls the emitted optical axis correction device according to the amount of error detected to correct the emitted optical axis. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2018 / 128118 Summary of the Invention [Problem to be solved by the invention]

[0005] In the method of Patent Document 1, the output optical axis is corrected according to the amount of error of the angle error detected by the light receiving angle detection device. According to the method of Patent Document 1, when the direction of the communication target is fixed, the direction of the light receiving system and the light sending axis of the spatial optical signal used in communication with the communication target can be adjusted. However, in the method of Patent Document 1, unless the direction of the communication target is fixed, it is not possible to align the direction of the light receiving system and the light sending axis of the spatial optical signal. In other words, in the method of Patent Document 1, it is not possible to establish spatial optical communication using spatial optical signals with a communication target arranged in an arbitrary direction.

[0006] An object of the present disclosure is to provide a communication device and a communication system capable of establishing spatial optical communication using a spatial optical signal with a communication target disposed in any direction. [Means for solving the problem]

[0007] A communication device according to one aspect of the present disclosure includes a transceiver integrated with a ball lens, a light receiver having a light receiving axis passing through the center of the ball lens, and a light transmitter having a light transmitting axis parallel to the light receiving axis, and a rotation mechanism that rotatably supports the transceiver along a circular orbit in horizontal and vertical planes centered on the ball lens. Effect of the Invention

[0008] According to the present disclosure, it is possible to provide a communication device and a communication system capable of establishing spatial optical communication using a spatial optical signal with a communication target disposed in any orientation. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a conceptual diagram illustrating an example of a configuration of a communication device according to the present disclosure. [Diagram 2] FIG. 1 is a conceptual diagram illustrating an example of a configuration of a communication device according to the present disclosure. [Diagram 3] 1 is a conceptual diagram illustrating an example of a configuration of a light receiver included in a communication device according to the present disclosure. [Figure 4]1 is a conceptual diagram illustrating an example of a configuration of a light receiver included in a communication device according to the present disclosure. [Diagram 5] 1 is a conceptual diagram illustrating an example of a configuration of a light receiver included in a communication device according to the present disclosure. [Figure 6] 1 is a conceptual diagram illustrating an example of a configuration of a light receiver included in a communication device according to the present disclosure. [Figure 7] 1 is a conceptual diagram illustrating an example of light focusing by a ball lens included in a communication device according to the present disclosure. [Figure 8] 1 is a conceptual diagram illustrating an example of irradiation of an optical signal to a photoreceiver included in a communication device according to the present disclosure. [Figure 9] 1 is a conceptual diagram illustrating an example of irradiation of an optical signal to a photoreceiver included in a communication device according to the present disclosure. [Figure 10] 1 is a conceptual diagram illustrating an example of a configuration of a light transmitter included in a communication device according to the present disclosure. [Figure 11] 1 is a conceptual diagram illustrating an example of a configuration of a light transmitter included in a communication device according to the present disclosure. [Figure 12] 1 is a conceptual diagram illustrating an example of a configuration of a light transmitter included in a communication device according to the present disclosure. [Figure 13] 1 is a conceptual diagram illustrating an example of a configuration of a light transmitter included in a communication device according to the present disclosure. [Figure 14] 2 is a conceptual diagram illustrating an example of a configuration of a communication control unit included in a communication device according to the present disclosure. FIG. [Figure 15] 1 is a conceptual diagram for explaining detection of the arrival direction of a spatial optical signal by a communication device in the present disclosure. [Figure 16] 11 is a conceptual diagram showing an example of changing the position of a light receiver included in a communication device according to the present disclosure. [Figure 17] 2 is a conceptual diagram illustrating an example of a configuration of a communication control unit included in a communication device according to the present disclosure. FIG. [Figure 18] 11A and 11B are conceptual diagrams for explaining an example of movement of a transceiver included in a communication device in the present disclosure in a vertical plane. [Figure 19] 11A and 11B are conceptual diagrams for explaining an example of movement of a transceiver included in a communication device in the present disclosure in a vertical plane. [Figure 20] 11 is a conceptual diagram for explaining an example of movement of a transceiver included in a communication device in the present disclosure in a horizontal plane. FIG. [Figure 21] 11 is a conceptual diagram for explaining an example of movement of a transceiver included in a communication device in the present disclosure in a horizontal plane. FIG. [Figure 22] FIG. 1 is a conceptual diagram illustrating an example of a configuration of a communication device according to the present disclosure. [Diagram 23] 11A and 11B are conceptual diagrams for explaining an example of movement of a transceiver included in a communication device in the present disclosure in a vertical plane. [Figure 24] 11 is a conceptual diagram for explaining an example of movement of a transceiver included in a communication device in the present disclosure in a horizontal plane. FIG. [Diagram 25] FIG. 1 is a conceptual diagram illustrating an example of a configuration of a communication device according to the present disclosure. [Figure 26] FIG. 1 is a conceptual diagram illustrating an example of a configuration of a communication device according to the present disclosure. [Figure 27] 1 is a conceptual diagram for explaining an example of transmission of a spatial optical signal by a transceiver included in a communication device in the present disclosure. [Figure 28] FIG. 1 is a conceptual diagram illustrating an example of a configuration of a communication device according to the present disclosure. [Figure 29] FIG. 1 is a conceptual diagram illustrating an example of a configuration of a communication device according to the present disclosure. [Diagram 30] FIG. 1 is a conceptual diagram illustrating an example of a configuration of a communication device according to the present disclosure. [Diagram 31] 1 is a conceptual diagram illustrating a configuration example of a communication system in which a communication device according to the present disclosure is arranged. [Diagram 32] FIG. 1 is a conceptual diagram illustrating an example of a configuration of a communication device according to the present disclosure. [Diagram 33] FIG. 2 is a block diagram showing an example of a hardware configuration for executing control and processing in the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, the embodiments for carrying out the present disclosure will be described with reference to the drawings. In this disclosure, the drawings used in the description of each embodiment relate to one or more embodiments. In addition, the elements included in each drawing may apply to one or more embodiments. The embodiments described below are limited in a manner that is technically preferable for carrying out the present disclosure, but the scope of the disclosure is not limited to the following. In all the drawings used in the description of the following embodiments, the same reference numerals are used for similar parts unless otherwise specified. In the following embodiments, repeated description of similar configurations and operations may be omitted.

[0011] In all the drawings used to explain the following embodiments, the direction of the arrows in the drawings is an example, and does not limit the direction of light or signals. In addition, the lines showing the trajectory of light in the drawings are conceptual, and do not accurately represent the actual traveling direction or state of light. For example, in the drawings, the change in the traveling direction or state of light due to refraction, reflection, diffusion, etc. at the interface between air and a substance may be omitted, or a light beam may be represented by a single line. In addition, cross sections may not be hatched due to reasons such as illustrating an example of a light path or making the configuration too crowded.

[0012] (First embodiment) First, a receiving device according to the first embodiment will be described with reference to the drawings. The communication device of this embodiment is used for optical space communication in which signal light propagating through space (hereinafter also referred to as spatial optical signal) is transmitted and received. The communication device of this embodiment may be used for applications other than optical space communication as long as it transmits and receives light propagating through space. Note that the drawings used in the description of this embodiment are conceptual and do not accurately depict the actual structure.

[0013] (composition) Fig. 1 is a conceptual diagram showing an example of the configuration of a communication device 1 in the present disclosure. Fig. 1 is a conceptual diagram of communication device 1 viewed from a side perspective. The communication device includes a transceiver 10, a ball lens 11, and a rotation mechanism 16. The rotation mechanism 16 has a vertical rotation mechanism 161 and a horizontal rotation mechanism 162. In the following, an overview of the transceiver 10, the ball lens 11, and the rotation mechanism 16 will be described first, and then the optical receiver 12, the communication control unit 13, and the optical transmitter 15 included in the transceiver 10 will be described individually.

[0014] The ball lens 11 is placed on a support 171 that is installed on the upper surface of the horizontal rotation mechanism 162. The ball lens 11 is a spherical lens. In the following, the center of the ball lens 11 is referred to as C B The ball lens 11 is an optical element that focuses a spatial optical signal arriving from the outside. The ball lens 11 is spherical when viewed from an arbitrary angle. The ball lens 11 focuses the incident spatial optical signal. The light (also called signal light) originating from the spatial optical signal focused by the ball lens 11 is focused toward the focusing area of ​​the ball lens 11. Since the ball lens 11 is spherical, it focuses a spatial optical signal arriving from an arbitrary direction. That is, the ball lens 11 exhibits the same focusing performance for a spatial optical signal arriving from an arbitrary direction. The light that enters the ball lens 11 is refracted when entering the inside of the ball lens 11. In addition, the light traveling inside the ball lens 11 is refracted again when it is emitted to the outside of the ball lens 11. Most of the light emitted from the ball lens 11 is focused toward the focusing area.

[0015] For example, ball lens 11 can be made of materials such as glass, crystal, and resin. When receiving a spatial optical signal in the visible region, a material that transmits / refracts light in the visible region can be used for ball lens 11. For example, optical glass such as crown glass and flint glass can be used for ball lens 11. For example, crown glass such as BK (Boron Kron) can be used for ball lens 11. For example, flint glass such as LaSF (Lanthanum Schwerflint) can be used for ball lens 11. For example, quartz glass can be used for ball lens 11. For example, crystal such as sapphire can be used for ball lens 11. For example, transparent resin such as acrylic can be used for ball lens 11.

[0016] When the spatial optical signal is light in the near-infrared region (hereinafter also referred to as near-infrared), a material that transmits near-infrared light is used for the ball lens 11. For example, when receiving a spatial optical signal in the near-infrared region of about 1.5 micrometers (μm), materials such as silicon can be used for the ball lens 11 in addition to glass, crystal, resin, etc. When the spatial optical signal is light in the infrared region (hereinafter also referred to as infrared), a material that transmits infrared light is used for the ball lens 11. For example, when the spatial optical signal is infrared, materials such as silicon, germanium, and chalcogenide can be used for the ball lens 11. There is no limitation on the material of the ball lens 11 as long as it can transmit / refract light in the wavelength region of the spatial optical signal. The material of the ball lens 11 may be appropriately selected according to the required refractive index and application.

[0017] The transceiver 10 has a light receiver 12, a communication control unit 13, and a light transmitter 15. The light receiver 12, the communication control unit 13, and the light transmitter 15 are housed inside the housing of the transceiver 10. In FIG. 1, an example of an area in which the light receiver 12, the communication control unit 13, and the light transmitter 15 are arranged is shown by a broken line. Note that in FIG. 1, the area (broken line) in which the light receiver 12, the communication control unit 13, and the light transmitter 15 are arranged is a rough representation of their positions, and does not represent their exact positions. In the housing of the transceiver 10, windows are formed in front of the light receiving surface of the light receiver 12 and in front of the light transmitting surface of the light transmitter 15. For example, a window material formed of a material through which a spatial optical signal is transmitted is arranged in the window. For example, the window may be open.

[0018] Optical receiver 12 is disposed in a light-concentration region including the light-concentration point of ball lens 11. The light-concentration point of ball lens 11 is not uniquely determined. Therefore, optical receiver 12 is disposed in a light-concentration region including the light-concentration point of ball lens 11. In the example of FIG. 1, optical receiver 12 is disposed to the side of ball lens 11. Optical receiver 12 includes multiple light-receiving elements for direction detection and a light-receiving element for communication. The light-receiving element for communication is disposed near the light-concentration point. The multiple light-receiving elements for direction detection are disposed closer to ball lens 11 than the light-receiving element for communication. As viewed from the ball lens, the multiple light-receiving elements for direction detection are disposed on concentric circles centered on the light-receiving element for communication. The light-receiving surfaces of the light-receiving element for direction detection and the light-receiving element for communication are disposed facing ball lens 11. A perpendicular line (light-receiving axis A) to the light-receiving surface of the light-receiving element for communication is disposed so that the light-receiving surface is perpendicular to the light-receiving surface of the light-receiving element for communication. LR (also called the center C of ball lens 11) B The plurality of direction detection light receiving elements and the communication light receiving element output electrical signals to the communication control unit 13 according to the received optical signals.

[0019] The communication control unit 13 acquires an electrical signal derived from the optical signal received by the optical receiver 12. The communication control unit 13 controls the rotation mechanism 16 and the optical transmitter 15 according to the acquired electrical signal. The communication control unit 13 detects the arrival direction of the spatial optical signal according to the electrical signal derived from the multiple direction detection optical receivers. The communication control unit 13 controls the rotation mechanism 16 according to the arrival direction of the spatial optical signal to move the transceiver 10. The communication control unit 13 controls the optical transmitter 15 to transmit a spatial optical signal for scanning to establish communication with the communication target. The communication control unit 13 transmits and receives the spatial optical signal for scanning to and from the communication target, and adjusts the transmission and reception directions of the spatial optical signals. The communication control unit 13 moves the transceiver 10 to a position where the intensity of the optical signals received by the multiple direction detection optical receivers is uniform. The communication control unit 13 moves the transceiver 10 to a position where the intensity of the optical signal received by the communication optical receiver is maximized, and establishes communication with the communication target. When communication is established with a communication target, the communication control unit 13 transmits a spatial light signal for communication to the communication target.

[0020] The light transmitter 15 transmits a spatial optical signal in response to the control of the communication control unit 13. At the stage of establishing communication with a communication target, the light transmitter 15 transmits a spatial optical signal for scanning. When communication with a communication target is established, the light transmitter 15 transmits a spatial optical signal for communication. Light transmission axis A of the spatial optical signal transmitted from the light transmitter 15 LT The light-transmitting axis A of the spatial light signal transmitted from the light transmitter 15 passes above the ball lens 11. LT indicates the light receiving axis A of the light receiving element for communication of the receiver 12 LR It is parallel to the light transmission axis A. LT and receiving axis A LR are always parallel to each other. Therefore, by controlling the rotation mechanism 16 so that the light receiving surface of the light receiver 12 faces the communication target, the transmission direction of the spatial light signal can be directed to that communication target. In this embodiment, an example is given in which the light transmitter 15 includes a phase modulation type spatial light modulator. The phase modulation type spatial light modulator can adjust the transmission direction of the spatial light signal by a pattern (phase image) set in the modulation section. Therefore, the light transmission axis A for the same communication target can be adjusted. LTand receiving axis A LR Even if the optical axes are not perfectly parallel, the transmission and reception of the spatial optical signal can be optimized.

[0021] The rotation mechanism 16 has a vertical rotation mechanism 161 and a horizontal rotation mechanism 162. In the following, the vertical plane is a plane perpendicular to the horizontal plane. When the communication device 1 is placed on a horizontal plane, the vertical plane coincides with a circular plane. When the communication device 1 is placed at an angle to the horizontal plane, the vertical plane is perpendicular to the bottom surface of the communication device 1.

[0022] The vertical rotation mechanism 161 moves the transceiver 10 in a vertical plane. B The transmitter / receiver 10 is moved on an arc with the center at the center C of the ball lens 11. B The light receiving axis A of the light receiving element for communication of the receiver 12 is LR is the center C of the ball lens 11 B Always passes through.

[0023] The horizontal rotation mechanism 162 moves the transceiver 10 in a horizontal plane. B The transmitter / receiver 10 is moved on an arc with the center at the center C of the ball lens 11. B The light receiving axis A of the light receiving element for communication of the receiver 12 is LR is the center C of the ball lens 11 B Always passes through.

[0024] Vertical rotation mechanism 161 and horizontal rotation mechanism 162 include driving devices such as small motors, such as microstepping motors. Communication control unit 13 controls the driving devices included in vertical rotation mechanism 161 and horizontal rotation mechanism 162 to move transceiver 10 in the vertical plane and the horizontal plane.

[0025] 2 is a conceptual diagram for explaining an example of transmission and reception of a spatial optical signal in the transmitter / receiver 10. The receiver 12 has a light receiving axis A LR A spatial light signal S arriving along LR The light transmitter 15 receives the light along the light transmission axis A. LT along the spatial light signal S LT Transmits. Receiving axis A LR and light transmission axis A LT are always parallel. That is, the spatial light signal S LR and the receiving direction of the spatial light signal S LT The transmission direction is always parallel to the

[0026] [Receiver] 3 to 5 are conceptual diagrams showing an example of the configuration of the optical receiver 12. FIG. 3 is a side view of the optical receiver 12 seen from a lateral viewpoint. FIG. 4 is a perspective view of the light receiving surface of the optical receiver 12 seen from diagonally above. FIG. 5 is a front view of the optical receiver 12 seen from the viewpoint of the ball lens 11. The optical receiver 12 has a substrate 121, a direction detection light receiving element 122, a light guide tube 124, a communication light receiving element 125, and a wavelength filter 127. The optical receiver 12 has a plurality of direction detection light receiving elements 122. In the example of FIGS. 3 to 5, the optical receiver 12 has four direction detection light receiving elements 122. The number of direction detection light receiving elements 122 is not limited to four.

[0027] The substrate 121 is a substrate used for a printed circuit board. A through hole A is formed in the substrate 121. The opening diameter of the through hole A is formed to match the size of a first opening end (the opening end on the left side in FIG. 2) of the light guiding tube 124. On the first surface (the surface on the left side in FIG. 2) of the substrate 121, a plurality of light receiving elements 122 for direction detection are arranged around the through hole A. In the example of FIGS. 2 to 4, four light receiving elements 122 for direction detection are arranged around the through hole A.

[0028] The direction detection light receiving elements 122 are disposed on a first surface (the surface on the left side in FIG. 2) of the substrate 121. The direction detection light receiving elements 122 are disposed in a positional relationship that is point symmetrical with respect to the center of the through hole A of the substrate 121. The light receiving portion 123 of the direction detection light receiving element 122 is directed toward the ball lens 11 via the wavelength filter 127. The direction detection light receiving element 122 has sensitivity to light in the wavelength band of the spatial optical signal that is the communication target. For example, the direction detection light receiving element 122 is realized by a photodiode that has sensitivity to infrared light. For example, the direction detection light receiving element 122 is realized by an indium gallium arsenide InGaAs-based photodiode. For example, the communication light receiving element 125 is realized by an InGaAs-based photodiode. The direction detection light receiving element 122 only needs to be able to detect the spatial optical signal, so it may have a lower sensitivity than the communication light receiving element 125. The spatial optical signal received by the direction detection light receiving element 122 is converted into an electrical signal. The converted electrical signal is output to the communication control unit 13. If the communication control unit 13 includes an integrator (not shown), the converted electrical signal is supplied to the integrator included in the communication control unit 13. The electrical signal supplied to the integrator is integrated to a level that can be detected by the communication control unit 13.

[0029] The light guide tube 124 is a cylindrical member having a first opening end and a second opening end. The first opening end (the opening end on the left side in FIG. 2) is formed to match the opening diameter of the through hole A. The second opening end (the opening end on the right side in FIG. 2) has a smaller opening diameter than the first opening end. The opening diameter of the second opening end is formed to match the light receiving section 126 of the light receiving element 125 for communication. The opening diameter of the second opening end is larger than the outer circumference of the light receiving section 126 of the light receiving element 125 for communication. There are no particular limitations on the material and shape of the light guide tube 124. For example, a reflective surface that reflects the optical signal is formed on the inner surface of the light guide tube 124. For example, a light absorbing material for reducing diffuse reflection of the optical signal may be arranged on the inner surface of the light guide tube 124.

[0030] The communication light receiving element 125 is disposed at the second opening end of the light guide tube 124 (the opening end on the right side in FIG. 2). The light receiving portion 126 of the communication light receiving element 125 is directed toward the ball lens 11 via a wavelength filter 127. The communication light receiving element 125 has sensitivity to light in the wavelength band of the spatial optical signal that is the communication target. For example, the communication light receiving element 125 is realized by a photodiode that has sensitivity to infrared light. For example, the communication light receiving element 125 is realized by an indium gallium arsenide InGaAs-based photodiode. The spatial optical signal received by the communication light receiving element 125 is converted into an electrical signal. The converted electrical signal is output to the communication control unit 13.

[0031] The wavelength filter 127 is a wavelength filter through which light in the wavelength band of the spatial optical signal to be received passes. The wavelength filter 127 passes light in the wavelength band of the spatial optical signal to be received by the direction detection light receiving element 122 and the communication light receiving element 125. The wavelength filter 127 blocks light that is not to be received. The main purpose of the wavelength filter 127 is to reduce the influence of sunlight. In an environment with little influence of sunlight or external light, the wavelength filter 127 may be omitted.

[0032] FIG. 6 is a conceptual diagram showing another example (photoreceiver 12-1) of the photoreceiver 12. FIG. 6 is a view of the light receiving surface of the photoreceiver 12-1 as seen from an obliquely upward viewpoint. In the photoreceiver 12-1, a light receiving element 122-1 for direction detection is arranged instead of the light receiving element 122 for direction detection. For example, a silicon-based or germanium-based photodiode can be applied to the light receiving element 122-1 for direction detection. Compared to an InGaAs photodiode, a silicon-based or germanium-based photodiode can be set to have a larger light receiving area at a lower cost. In addition, a wavelength filter 127-1 that selectively passes light in a wavelength band to which the silicon-based or germanium-based photodiode and the InGaAs photodiode are sensitive is arranged in the photoreceiver 12-1. According to the configuration of FIG. 6, the light receiving area of ​​the light receiving element 122-1 for direction detection can be increased.

[0033] FIG. 7 is a conceptual diagram for explaining an example of a trajectory of light focused by ball lens 11. FIG. 7 is a conceptual diagram showing a part of ball lens 11 viewed from a side. The intensity of light in the light-focusing region of ball lens 11 changes depending on the position from ball lens 11. Compared to position a, position b (also called a focusing point) has a higher luminous flux density. Therefore, the intensity of light received at position b is higher. Light receiving section 126 of light receiving element 125 for communication is disposed near position b. Therefore, the light receiving efficiency of light receiving element 125 for communication is improved. In other words, light receiving section 126 of light receiving element 125 for communication is disposed in accordance with position b. In contrast, light receiving element 122 for direction detection is disposed closer to ball lens 11 than light receiving element 125 for communication.

[0034] FIG. 8 is a conceptual diagram showing an example of a state in which the signal light collected by the ball lens 11 is incident on the optical receiver 12. FIG. 8 shows a part of the optical receiver 12. FIG. 8 shows a cross-sectional view of the optical receiver 12 seen from a side perspective. In the example of FIG. 8, the signal light collected by the ball lens 11 is not irradiated to the light receiving portion 126 of the communication light receiving element 125, but is irradiated to the light receiving portion 123 of a part of the direction detection light receiving element 122. In the example of FIG. 8, the position of the optical receiver 12 needs to be changed. The communication control unit 13 changes the position of the transceiver 10 according to the position of the direction detection light receiving element 122 that has received the signal light. In the example of FIG. 8, the communication control unit 13 moves the transceiver 10 upward.

[0035] 9 is a conceptual diagram showing an example of how signal light collected by ball lens 11 enters optical receiver 12. FIG. 9 shows a part of optical receiver 12. FIG. 9 shows a cross-sectional view of optical receiver 12 seen from a side perspective. In the example of FIG. 9, signal light collected by ball lens 11 is irradiated onto light receiving section 126 of communication optical receiver 125. In the example of FIG. 9, an electrical signal derived from the signal light received by communication optical receiver 125 is processed by communication control section 13.

[0036] [Light transmitter] FIG. 10 is a conceptual diagram showing an example of the light transmitter 15 (light transmitter 15-1). FIG. 10 is an example in which light in the Fraunhofer region is used. In FIG. 10, the region in which the light transmitter 15-1 is arranged is indicated by a dashed frame. The light transmitter 15-1 has a light source 151, a collimator 152, and a spatial light modulator 153. FIG. 10 conceptually illustrates the positional relationship between the light source 151, the collimator 152, and the spatial light modulator 153. FIG. 10 does not limit the positional relationship between the light source 151, the collimator 152, and the spatial light modulator 153.

[0037] The light source 151 is disposed inside the housing of the transceiver 10 with its emission surface facing diagonally upward. The emission surface of the light source 151 faces the modulation section 1530 of the spatial light modulator 153 disposed above. The light source 151 includes at least one emitter (not shown). The at least one emitter emits emission light according to the control of the communication control section 13. The emission light emitted from the emitter is converted into parallel light (illumination light) by the collimator 152.

[0038] For example, the light source 151 may include a plurality of emitters that emit light in the same wavelength band. For example, the light source 151 is realized by a laser array in which a plurality of emitters are arranged in an array. For example, the laser array has a plurality of emitters arranged in 4 rows x 2 columns. For example, the light source 151 may be a combination of a plurality of emitters that emit illumination light in the same wavelength band and an emitter that emits illumination light in a wavelength band different from the emitters. For example, the light source 151 may be a combination of an emitter that emits laser light in a wavelength band used for communication with a communication target and an emitter that emits laser light in a wavelength band different from the laser light. For example, one of the plurality of emitters that constitute the laser array is a search emitter, and the others are communication emitters. For example, the search emitter emits light in a wavelength band of 850 nm, and the communication emitter emits light in a wavelength band of 1550 nm. If the laser array is configured in this way, a search can be performed using a search emitter (850 nm), and when the search is completed, the communication can be switched to a communication using a communication emitter (1550 nm). In this case, a silicon-based photodiode can be applied to the direction detection light receiving element 122. On the other hand, a germanium-based photodiode can be applied to the direction detection light receiving element 122. A wavelength filter that selectively passes light in the 850 nm wavelength band is disposed in front of the direction detection light receiving element 122. A wavelength filter that selectively passes light in the 1550 nm wavelength band is disposed in front of the communication light receiving element 125. Compared to the germanium-based, the silicon-based photodiode is cheaper and can be used with a larger photodiode. Even if different wavelength filters are applied to the direction detection light receiving element 122 and the communication light receiving element 125, the accuracy of direction detection is improved if a silicon-based photodiode can be applied to the direction detection light receiving element 122. In addition, the search emitter and the communication emitter may emit light in the same wavelength band. In this case, a single wavelength filter can be disposed in front of the direction detection light receiving element 122 and the communication light receiving element 125.

[0039] For example, the emitter included in the light source 151 emits a laser beam in a predetermined wavelength band. The wavelength of the laser beam emitted from the emitter is not particularly limited and may be selected according to the application. For example, the emitter emits a laser beam in a visible or infrared wavelength band. For example, in the case of near infrared rays of 800 to 1000 nm, the laser class can be raised compared to visible light, and therefore the sensitivity can be improved compared to visible light. For example, in the case of infrared rays in a wavelength band of 1.55 micrometers (μm), a higher output laser light source can be used than in the case of near infrared rays in the 800 to 1000 nm wavelength band. As a laser light source that emits infrared rays in a wavelength band of 1.55 μm, an aluminum gallium arsenide phosphide (AlGaAsP)-based laser light source or an indium gallium arsenide (InGaAs)-based laser light source can be used. The longer the wavelength of the laser beam, the larger the diffraction angle can be and the higher the energy can be set. For example, the emitter may be realized by a surface-emitting element such as a PCSEL (Photonic Crystal Surface Emitting Laser) type laser.

[0040] The collimator 152 is disposed on the emission surface of the light source 151. The collimator 152 converts the emission light emitted from the light source 151 into parallel light. The parallel light (illumination light) converted by the collimator 152 is irradiated onto the modulation section 1530 of the spatial light modulator 153. For example, each of the multiple emitters is associated with at least one of the multiple modulation regions set in the modulation section 1530 of the spatial light modulator 153. The illumination light derived from the emission light emitted from each of the multiple emitters travels toward the associated modulation region.

[0041] The spatial light modulator 153 is a phase modulation type spatial light modulator. The spatial light modulator 153 has a modulation section 1530. The spatial light modulator 153 is disposed diagonally above the light source 151. The modulation section 1530 of the spatial light modulator 153 faces the emission surface of the light source 151. In the example of FIG. 10, the spatial light modulator 153 is disposed inside the transceiver 10. The spatial light modulator 153 converts reflected light (modulated light) of the illumination light irradiated to the modulation section 1530 into a spatial light signal S. LTThe illumination light irradiated to the modulation section 1530 of the spatial light modulator 153 is modulated according to a pattern (phase image) set in the modulation section 1530. The modulated light modulated by the modulation section 1530 is transmitted as a spatial light signal. The traveling direction of the spatial light signal (modulated light) is adjusted according to the pattern (phase image) set in the modulation section 1530.

[0042] For example, the spatial light modulator 153 is realized by a spatial light modulator using ferroelectric liquid crystal, homogeneous liquid crystal, vertically aligned liquid crystal, or the like. For example, the spatial light modulator 153 can be realized by LCOS (Liquid Crystal on Silicon). The spatial light modulator 153 may also be realized by MEMS (Micro Electro Mechanical System). In the phase modulation type spatial light modulator 153, the spatial light signal S LT By operating the parts used for transmitting light in a sequential manner, it is possible to concentrate energy on the image portion. Therefore, when the phase modulation type spatial light modulator 153 is used, if the output of the emitter included in the light source 151 is the same, the image can be displayed brighter than with other methods.

[0043] At least one modulation area is set in the modulation section 1530 of the spatial light modulator 153. The number of modulation areas set in the modulation section 1530 is set according to the number of emitters included in the light source 151. Each of the multiple modulation areas is associated with one of the multiple emitters included in the light source 151. Each of the multiple modulation areas is irradiated with illumination light derived from the laser light emitted from the associated emitter. However, as long as the illumination light derived from the laser light emitted from the emitter is incident on the modulation surface of the modulation area, the correspondence between the modulation area and the emitter is not particularly limited. In addition, the number of modulation areas set in the modulation section 1530 may be different from the number of emitters included in the light source 151.

[0044] The modulation area is divided into a plurality of areas (also called tiling). A phase image is assigned to each of the plurality of tiles. Each of the plurality of tiles is composed of a plurality of pixels. A phase image corresponding to an image to be projected is set to each of the plurality of tiles. A phase image is tiled to each of the plurality of tiles assigned to the modulation area. For example, a phase image generated in advance is set to each of the plurality of tiles. When illumination light is irradiated to the modulation area with phase images set to the plurality of tiles, modulated light that forms an image corresponding to the phase image of each tile is emitted. The more tiles that are set in the modulation area, the clearer the image that can be displayed, but the resolution decreases when the number of pixels in each tile decreases. Therefore, the size and number of tiles set in the modulation area are set according to the application.

[0045] In each of the multiple modulation regions, a spatial optical signal S is LT A pattern (also called a phase image) corresponding to the image displayed by the modulation area is set in each of the multiple modulation areas. A pattern (phase image) is set in each of the multiple modulation areas. The illumination light irradiated to each of the multiple modulation areas is modulated according to the pattern (phase image) set in the modulation area. The modulated light modulated in each of the multiple modulation areas is represented as a spatial light signal S LT is sent as

[0046] For example, a shield (not shown) may be disposed downstream of the spatial light modulator 153. The shield is a frame that shields unnecessary light components contained in the modulated light and defines the outer edge of the display area of ​​the projected light. For example, the shield is an aperture. In such an aperture, a slit-shaped opening is formed in a portion that passes light (desired light) that forms a desired image. The desired light is first-order diffracted light. The shield passes the desired light and shields unnecessary light components. For example, the shield shields zero-order light contained in the modulated light, unnecessary first-order light that appears at a position point-symmetrical with respect to the desired light with the zero-order light as the center, and ghost images that include second-order or higher-order light. Details of the shield are omitted. For example, a projection lens (not shown) may be disposed downstream of the spatial light modulator 153.

[0047] FIG. 11 is a conceptual diagram showing an example of the light transmitter 15 (light transmitter 15-2). The light transmitter 15-2 (FIG. 11) has a configuration in which a plane mirror 154 is added to the light transmitter 15-1 (FIG. 10). In the light transmitter 15-2 (FIG. 11), a configuration in which an image is formed in the Fraunhofer region by reflection by the plane mirror 154 is realized. In FIG. 11, the region in which the light transmitter 15-2 is arranged is shown by a dashed frame. The light transmitter 15-2 has a light source 151, a collimator 152, a spatial light modulator 153, and a plane mirror 154. FIG. 11 conceptually shows the positional relationship between the light source 151, the collimator 152, the spatial light modulator 153, and the plane mirror 154. FIG. 11 does not limit the positional relationship between the light source 151, the collimator 152, the spatial light modulator 153, and the plane mirror 154. The light source 151, the collimator 152, and the spatial light modulator 153 of the light sender 15-2 (FIG. 11) are similar to those of the light sender 15-1 (FIG. 10), and therefore detailed description thereof will be omitted.

[0048] Light source 151 is disposed inside the housing of transceiver 10 with its emission surface facing diagonally downward. The emission surface of light source 151 is directed toward reflecting surface 1540 of plane mirror 154 disposed diagonally downward. Light source 151 includes at least one emitter (not shown). At least one emitter emits emission light in accordance with the control of communication control unit 13. The emission light emitted from the emitter is converted into parallel light (illumination light) by collimator 152. Compared to the configuration of FIG. 10, light source 151 is disposed at a position farther away from ball lens 11 in the configuration of FIG. 11. Therefore, compared to the configuration of FIG. 10, heat generated from light source 151 is more easily released to the outside in the configuration of FIG. 11.

[0049] Collimator 152 is disposed on the emission surface of light source 151. Collimator 152 converts the light emitted from light source 151 into parallel light. The parallel light (illumination light) converted by collimator 152 is irradiated onto reflecting surface 1540 of plane mirror 154.

[0050] The plane mirror 154 is disposed obliquely below the light source 151 and the spatial light modulator 153. The plane mirror 154 has a reflecting surface 1540. The reflecting surface 1540 is directed toward the light source 151 and the spatial light modulator 153. Illumination light is irradiated onto the reflecting surface 1540. The reflecting surface 1540 reflects the irradiated illumination light toward a modulation section 1530 of the spatial light modulator 153.

[0051] The spatial light modulator 153 is disposed diagonally above the plane mirror 154. In the example of FIG. 11, the spatial light modulator 153 is disposed inside the transceiver 10. A modulation section 1530 of the spatial light modulator 153 is directed toward a reflecting surface 1540 of the plane mirror 154. The spatial light modulator 153 converts the reflected light (modulated light) reflected by the reflecting surface 1540 of the plane mirror 154 into a spatial light signal S LT The illumination light irradiated to the modulation section 1530 of the spatial light modulator 153 is modulated according to a pattern (phase image) set in the modulation section 1530. The modulated light modulated by the modulation section 1530 is transmitted as a spatial light signal. The traveling direction of the spatial light signal (modulated light) is adjusted according to the pattern (phase image) set in the modulation section 1530.

[0052] FIG. 12 is a conceptual diagram showing an example of the light transmitter 15 (light transmitter 15-3). The light transmitter 15-3 (FIG. 12) has a configuration in which the positions of the spatial light modulator 153 and the plane mirror 154 are swapped in the configuration of the light transmitter 15-2 (FIG. 11). In the light transmitter 15-3 (FIG. 12), a Fraunhofer configuration is realized by folding back the light with the plane mirror 154. In FIG. 12, the area in which the light transmitter 15-3 is arranged is shown by a dashed frame. The light transmitter 15-3 has a light source 151, a collimator 152, a spatial light modulator 153, and a plane mirror 154. FIG. 12 conceptually shows the positional relationship between the light source 151, the collimator 152, the spatial light modulator 153, and the plane mirror 154. FIG. 12 does not limit the positional relationship between the light source 151, the collimator 152, the spatial light modulator 153, and the plane mirror 154. Since the light source 151, the collimator 152, and the spatial light modulator 153 of the light sender 15-3 (FIG. 12) are similar to those of the light senders 15-1 and 15-2 (FIGS. 10 and 11), detailed description thereof will be omitted.

[0053] The light source 151 is disposed inside the housing of the transceiver 10 with its emission surface facing diagonally downward. The emission surface of the light source 151 is directed toward a modulation section 1530 of the spatial light modulator 153 disposed diagonally downward. The light source 151 includes at least one emitter (not shown). The at least one emitter emits emission light according to the control of the communication control section 13. The emission light emitted from the emitter is converted into parallel light (illumination light) by a collimator 152.

[0054] The collimator 152 is disposed on the emission surface of the light source 151. The collimator 152 converts the light emitted from the light source 151 into parallel light. The parallel light (illumination light) converted by the collimator 152 is irradiated onto a modulation section 1530 of the spatial light modulator 153.

[0055] The spatial light modulator 153 is disposed diagonally below the light source 151 and the plane mirror 154. In the example of FIG. 12, the spatial light modulator 153 is disposed inside the transceiver 10. The modulation section 1530 of the spatial light modulator 153 is directed toward the reflecting surface 1540 of the plane mirror 154. The spatial light modulator 153 is disposed at a position where it is irradiated with the illumination light that has passed through the collimator 152. The illumination light irradiated to the modulation section 1530 of the spatial light modulator 153 is modulated according to a pattern (phase image) set in the modulation section 1530. The modulated light modulated by the modulation section 1530 of the spatial light modulator 153 proceeds toward the reflecting surface 1540 of the plane mirror 154.

[0056] The plane mirror 154 is disposed obliquely above the spatial light modulator 153. The plane mirror 154 has a reflecting surface 1540. The reflecting surface 1540 is directed toward the spatial light modulator 153. Modulated light modulated by the modulation section 1530 of the spatial light modulator 153 is irradiated onto the reflecting surface 1540. The reflecting surface 1540 reflects the irradiated modulated light. The modulated light reflected by the reflecting surface 1540 is transmitted as a spatial light signal. The traveling direction of the spatial light signal (modulated light) is adjusted according to the set pattern (phase image) of the modulation section 1530.

[0057] FIG. 13 is a conceptual diagram showing an example of the light sender 15 (light sender 15-4). The light sender 15-4 (FIG. 13) has a configuration in which the plane mirror 154 in the configuration of the light sender 15-3 (FIG. 12) is replaced with a concave mirror 155. In FIG. 13, the area in which the light sender 15-4 is arranged is shown by a dashed frame. The light sender 15-4 has a light source 151, a collimator 152, a spatial light modulator 153, and a concave mirror 155. FIG. 13 conceptually shows the positional relationship between the light source 151, the collimator 152, the spatial light modulator 153, and the concave mirror 155. FIG. 13 does not limit the positional relationship between the light source 151, the collimator 152, the spatial light modulator 153, and the concave mirror 155. Since the light source 151, the collimator 152, and the spatial light modulator 153 of the light sender 15-2 (FIG. 11) are similar to those of the light senders 15-1 to 15-3 (FIGS. 10 to 12), detailed description thereof will be omitted.

[0058] The light source 151 is disposed inside the housing of the transceiver 10 with its emission surface facing diagonally downward. The emission surface of the light source 151 is directed toward a modulation section 1530 of the spatial light modulator 153 disposed diagonally downward. The light source 151 includes at least one emitter (not shown). The at least one emitter emits emission light according to the control of the communication control section 13. The emission light emitted from the emitter is converted into parallel light (illumination light) by a collimator 152.

[0059] The collimator 152 is disposed on the emission surface of the light source 151. The collimator 152 converts the light emitted from the light source 151 into parallel light. The parallel light (illumination light) converted by the collimator 152 is irradiated onto a modulation section 1530 of the spatial light modulator 153.

[0060] The spatial light modulator 153 is disposed diagonally below the light source 151 and the concave mirror 155. In the example of FIG. 13, the spatial light modulator 153 is disposed inside the transceiver 10. The modulation section 1530 of the spatial light modulator 153 is directed toward the reflecting surface 1540 of the concave mirror 155. The spatial light modulator 153 is disposed at a position where it is irradiated with the illumination light that has passed through the collimator 152. The illumination light irradiated to the modulation section 1530 of the spatial light modulator 153 is modulated according to a pattern (phase image) set in the modulation section 1530. The modulated light modulated by the modulation section 1530 of the spatial light modulator 153 proceeds toward the reflecting surface 1550 of the concave mirror 155.

[0061] The concave mirror 155 is disposed obliquely above the spatial light modulator 153. The concave mirror 155 has a concave reflecting surface 1550. The reflecting surface 1550 is directed toward the spatial light modulator 153. Modulated light modulated by the modulation section 1530 of the spatial light modulator 153 is irradiated onto the reflecting surface 1550. The reflecting surface 1550 reflects the irradiated modulated light. The modulated light reflected by the reflecting surface 1550 is transmitted as a spatial light signal. The traveling direction of the spatial light signal (modulated light) is adjusted according to the pattern (phase image) set by the modulation section 1530. The traveling direction of the spatial light signal (modulated light) is also adjusted according to the irradiation position on the reflecting surface 1550.

[0062] Compared to the case where the plane mirror 154 is used, the spatial light signal S LT Therefore, if the distance from the communication device 1 is the same, the spatial optical signal S is smaller when the concave mirror 155 is used than when the plane mirror 154 is used. LT In other words, the intensity of the spatial light signal S is greater when the concave mirror 155 is used than when the plane mirror 154 is used. LT Therefore, the communication distance can be extended with the light transmitter 15-4 (FIG. 13) compared with the light transmitters 15-1 to 15-3 (FIGS. 10 to 12).

[0063] [Communication control section] 14 is a conceptual diagram showing an example (communication control unit 13-1) of the configuration of the communication control unit 13. The communication control unit 13 has a direction detection circuit 14-1, a drive unit 131, a transmission control unit 132, a receiving circuit 133, and a communication unit 135.

[0064] The direction detection circuit 14-1 includes a plurality of detectors 141, an analog-to-digital conversion circuit (ADC 146), and a direction detection unit 147 (ADC: Analog-to-Digital Converter). Each of the plurality of detectors 141 is connected to each of the plurality of light receiving elements 122 for direction detection. The detector 141 includes an amplifier 143 and a wave detector 144. The plurality of detectors 141 may include a band pass filter (BPF: Band Path Filter) corresponding to a frequency band to be received. The BPF cuts off signals derived from ambient light such as sunlight. The detector 141 may also be configured to include a plurality of wave detectors corresponding to a plurality of frequency bands.

[0065] The amplifier 143 is connected to the direction detection light receiving element 122. An electrical signal derived from the signal light received by the direction detection light receiving element 122 is input to the amplifier 143. The amplifier 143 amplifies the input electrical signal at a set amplification factor. For example, by operating the amplifier 143 in alternating current (AC) mode, the influence of sunlight can be eliminated. The amplification factor of the amplifier 143 can be set arbitrarily. The electrical signal amplified by the amplifier 143 is output to the detector 144.

[0066] The signal having the modulation frequency to be received and amplified by the amplifier 143 is input to the detector 144. The detector 144 detects the input signal. An amplifier may be disposed after the detector 144. The signal detected by the detector 144 is supplied to the ADC 146.

[0067] The signals detected by each of the multiple detectors 144 are input to the ADC 146. The ADC 146 converts the input signals (analog signals) into digital signals. The converted digital signals are output to the direction detection unit 147.

[0068] The direction detection unit 147 receives signals originating from each of the plurality of direction detection light receiving elements 122. The direction detection unit 147 detects the arrival direction of the spatial optical signal according to the state in which the optical signal is received by each of the plurality of direction detection light receiving elements 122.

[0069] FIG. 15 is a conceptual diagram for explaining detection of the arrival direction of a spatial optical signal by the direction detection unit 147. FIG. 15 is a conceptual diagram of the light receiving surface of the light receiver 12 as viewed from the viewpoint of the ball lens 11. FIG. 15 shows the positional relationship between the light receiving unit 123 of the light receiving element 122 for direction detection and the light receiving unit 126 of the light receiving element 125 for communication. In FIG. 15, the light receiving units 123 of the light receiving elements 122 for direction detection are differentiated from one another by adding numbers (1 to 4) to the end of the reference numerals representing the light receiving units 123. FIG. 15 also shows the inside of the light guide tube 124. The light receiving units 123-1 to 123-4 are arranged on the circumference of a circle centered on the light receiving unit 126 of the light receiving element 125 for communication. FIG. 15 shows an example of a light collecting range of light collected by the ball lens 11 as a circle.

[0070] The signal light irradiated within the light-collecting range R1 (dashed line) is received by the light-receiving unit 123-3 and the light-receiving unit 123-4. The direction detection unit 147 sets the movement direction of the transceiver 10 according to the reception state of the signal light by the light-receiving unit 123-3 and the light-receiving unit 123-4. When the signal light is irradiated within the light-collecting range R1 (dashed line), the direction detection unit 147 outputs a control signal to the drive unit 131 to move the position of the light-receiver 12 to the lower left. The direction detection unit 147 may set the movement amount of the transceiver 10 according to the intensity of the signal light received by the light-receiving unit 123-3 and the light-receiving unit 123-4. The signal light irradiated within the light-collecting range R1 (dashed line) is received by the light-receiving unit 126 of the communication light-receiving element 125. The direction detection unit 147 may set the movement direction and amount of movement of the optical receiver 12, taking into account the state in which the optical receiver 126 receives the signal light.

[0071] The signal light irradiated within the light-collecting range R2 (dotted line) is received by the light-receiving unit 123-4. The direction detection unit 147 sets the movement direction of the transceiver 10 according to the reception state of the signal light by the light-receiving unit 123-4. When the signal light is irradiated within the light-collecting range R2 (dotted line), the direction detection unit 147 outputs a control signal to the drive unit 131 to move the position of the light-receiver 12 to the left. The direction detection unit 147 may set the movement amount of the transceiver 10 according to the intensity of the signal light received by the light-receiving unit 123-4.

[0072] The signal light irradiated within the light-collecting range R3 (two-dot chain line) is received by the light-receiving units 123-2 and 123-3. The direction detection unit 147 sets the movement direction of the transceiver 10 according to the reception state of the signal light by the light-receiving units 123-2 and 123-3. When the signal light is irradiated within the light-collecting range R3 (two-dot chain line), the direction detection unit 147 outputs a control signal to the drive unit 131 to move the position of the light-receiver 12 to the lower right. The direction detection unit 147 may set the movement amount of the transceiver 10 according to the intensity of the signal light received by the light-receiving units 123-2 and 123-3.

[0073] Furthermore, the direction detection unit 147 outputs the moving direction of the transceiver 10 to the transmission control unit 132. Information including the moving direction of the transceiver 10 is notified to the communication target by using a spatial optical signal.

[0074] The driving unit 131 acquires a control signal for setting the movement direction and amount of movement of the optical receiver 12 from the direction detection unit 147. The driving unit 131 drives the vertical rotation mechanism 161 and the horizontal rotation mechanism 162 included in the rotation mechanism 16 in response to the acquired control signal. The driving unit 131 drives the drive devices included in the vertical rotation mechanism 161 and the horizontal rotation mechanism 162 to move the transceiver 10 in the vertical plane and the horizontal plane.

[0075] 16 is a conceptual diagram showing an example in which the position of the light receiver 12 is changed according to the intensity of the signal light received by the light receiving units 123-1 to 123-4 included in the plurality of direction detection light receiving elements 122. FIG. I 1 shows a time series of changes in the relative position of the optical receiver 12 with respect to the object 1. In the following, an example of adjusting the position of the optical receiver 12 based on the positional relationship on the paper surface will be described.

[0076] At time T1, the signal light is received by the light receiving unit 123-4. In this state, if the position of the transceiver 10 is moved to the left, the light collection range R I The light receiving unit 126 of the light receiving element 125 for communication approaches the center of the light receiving unit 126. The direction detection unit 147 outputs a control signal to the drive unit 131 to move the position of the transceiver 10 to the left. In response to the control signal, the drive unit 131 drives the vertical rotation mechanism 161 and the horizontal rotation mechanism 162 included in the rotation mechanism 16 to move the position of the transceiver 10 to the left.

[0077] At timing T2, the signal light is received by the light receiving units 123-1 and 123-4 in response to a change in the position of the transceiver 10. Also, at timing T2, the signal light is received by the light receiving unit 126 of the communication light receiving element 125. In this state, if the position of the transceiver 10 is moved diagonally upward to the left, the light collection range R I The light receiving unit 126 of the light receiving element 125 for communication approaches the center of the light receiving unit 126. The direction detection unit 147 outputs a control signal to the drive unit 131 to move the position of the transceiver 10 diagonally upward and to the left. In response to the control signal, the drive unit 131 drives the vertical rotation mechanism 161 and the horizontal rotation mechanism 162 included in the rotation mechanism 16 so as to move the position of the transceiver 10 diagonally upward and to the left.

[0078] At timing T3, the signal light is received by the light receiving units 123-2 and 123-3 in response to the change in the position of the transceiver 10. Also, at timing T3, the signal light is received by the light receiving unit 126 of the communication light receiving element 125. In this state, if the position of the transceiver 10 is moved diagonally downward to the right, the light collection range RI The light receiving unit 126 of the light receiving element 125 for communication approaches the center of the light receiving element 125. The direction detection unit 147 outputs a control signal to the drive unit 131 to move the position of the transceiver 10 diagonally downward to the right. At this time, the direction detection unit 147 sets the moving distance of the light receiver 12 to be shorter than that in the transition from timing T2 to timing T3. In response to the control signal, the drive unit 131 drives the vertical rotation mechanism 161 and the horizontal rotation mechanism 162 included in the rotation mechanism 16 so as to move the position of the transceiver 10 diagonally downward to the right.

[0079] At timing T4, in response to the change in the position of the transceiver 10, the signal light is received by all the light receiving sections 123-1 to 123-4 and the light receiving section 126 of the communication light receiving element 125. This state is within the light collection range R I In this state, the light receiving portion 126 of the light receiving element 125 for communication is substantially aligned with the center of the light receiving element 126. In this state, the light signal originating from the spatial optical signal transmitted from the communication target can be efficiently received by the light receiving element 125 for communication.

[0080] The receiving circuit 133 acquires an electrical signal derived from an optical signal received by the light receiving unit 126 of the communication light receiving element 125. The receiving circuit 133 amplifies the acquired electrical signal. The receiving circuit 133 converts the amplified electrical signal from an analog signal to a digital signal. The receiving circuit 133 outputs the converted digital signal to the communication unit 135. For example, the receiving circuit 133 may be provided with a limiting amplifier (not shown) in front of the amplifier (not shown). If a limiting amplifier is provided, a dynamic range can be secured. For example, the receiving circuit 133 may be provided with a high-pass filter or a band-pass filter (not shown). The high-pass filter or the band-pass filter cuts off a signal derived from ambient light such as sunlight, and selectively passes a signal of a high-frequency component corresponding to the wavelength band of the spatial optical signal.

[0081] The communication unit 135 decodes the signal output from the receiving circuit 133. The communication unit 135 causes the transmission control unit 132 to transmit a spatial optical signal in response to the decoded signal.

[0082] 17 is a conceptual diagram showing an example of the configuration of the communication control unit 13 (communication control unit 13-2). The communication control unit 13 has a direction detection circuit 14-2, a drive unit 131, a transmission control unit 132, a receiving circuit 133, and a communication unit 135. The communication control unit 13-2 (FIG. 17) differs from the communication control unit 13-1 (FIG. 14) in the configuration of the detector 142 included in the direction detection circuit 14-2.

[0083] Detector 142 includes integrator 145 in addition to amplifier 143 and detector 144. Integrator 145 increases the intensity of the signal by integrating the signal that has passed through amplifier 143 and detector 144. A photodiode capable of high-speed operation has a small light receiving area and receives a small intensity of an optical signal. According to the configuration of communication control unit 13-2 (FIG. 17), since the intensity of the signal can be increased by integrator 145, a photodiode capable of high-speed operation can be applied to direction detection light receiving element 122.

[0084] [Rotation mechanism] Figures 18 to 21 are conceptual diagrams for explaining an example of the movement of the rotation mechanism 16. Figures 18 to 19 relate to the operation of the vertical rotation mechanism 161. Figures 18 to 19 are views of the vertical rotation mechanism 161 as seen from a side perspective. Figures 20 to 21 relate to the operation of the horizontal rotation mechanism 162. Figures 20 to 21 are views of the vertical rotation mechanism 161 as seen from an above perspective.

[0085] FIG. 18 shows the spatial optical signal receiving axis A in the vertical plane. LR and light transmission axis A LT In this example, the light receiving axis A of the light receiver 12 of the transceiver 10 faces downward. In response to the control of the communication control unit 13, the vertical rotation mechanism 161 moves the transceiver 10 counterclockwise in the vertical plane (on the paper surface) along a circular orbit with the center of the ball lens 11 as the rotation axis. LR The vertical rotation mechanism 161 moves the transmitter / receiver 10 in a vertical plane so that the light receiving axis A of the receiver 12 always passes through the center of the ball lens 11. LR When the light-transmitting axis A of the light-transmitting device 15 is aligned in the direction of the communication target, LTis aligned in the direction of the communication target. As a result, in the vertical plane, the optical receiving axis A of the spatial optical signal LR and light transmission axis A LT is directed toward the communication target located diagonally below.

[0086] FIG. 19 shows the spatial optical signal receiving axis A in the vertical plane. LR and light transmission axis A LT In this example, the light receiving axis A of the light receiver 12 of the transceiver 10 is directed upward. In response to the control of the communication control unit 13, the vertical rotation mechanism 161 moves the transceiver 10 clockwise along a circular orbit in a vertical plane (on the paper surface) with the center of the ball lens 11 as the rotation axis. LR The vertical rotation mechanism 161 moves the transmitter / receiver 10 in a vertical plane so that the light receiving axis A of the receiver 12 always passes through the center of the ball lens 11. LR When the light-transmitting axis A of the light-transmitting device 15 is aligned in the direction of the communication target, LT is aligned in the direction of the communication target. As a result, in the vertical plane, the optical receiving axis A of the spatial optical signal LR and light transmission axis A LT is directed toward the communication target located diagonally above.

[0087] FIG. 20 shows the spatial optical signal receiving axis A in the horizontal plane. LR and light transmission axis A LT In the plan view, the light receiving axis A is LR and light transmission axis A LT In response to the control of the communication control unit 13, the horizontal rotation mechanism 162 moves the transceiver 10 counterclockwise along a circular orbit in a horizontal plane (on the paper surface) with the center of the ball lens 11 as the axis of rotation. LR The horizontal rotation mechanism 162 moves the transmitter / receiver 10 in a horizontal plane so that the light receiving axis A of the receiver 12 always passes through the center of the ball lens 11. LR When the light-transmitting axis A of the light-transmitting device 15 is aligned in the direction of the communication target, LT is aligned in the direction of the communication target. As a result, in the horizontal plane, the optical receiving axis A of the spatial optical signal is LR and light transmission axis A LTis directed toward the communication target located diagonally to the left.

[0088] FIG. 21 shows the spatial optical signal receiving axis A in the horizontal plane. LR and light transmission axis A LT In the plan view, the light receiving axis A is LR and light transmission axis A LT In response to the control of the communication control unit 13, the horizontal rotation mechanism 162 moves the transceiver 10 clockwise along a circular orbit in a horizontal plane (on the paper surface) with the center of the ball lens 11 as the axis of rotation. LR The horizontal rotation mechanism 162 moves the transmitter / receiver 10 in a horizontal plane so that the light receiving axis A of the receiver 12 always passes through the center of the ball lens 11. LR When the light-transmitting axis A of the light-transmitting device 15 is aligned in the direction of the communication target, LT is aligned in the direction of the communication target. As a result, in the horizontal plane, the optical receiving axis A of the spatial optical signal is LR and light transmission axis A LT is directed toward the communication target located diagonally to the right.

[0089] As shown in FIGS. 18 to 21, by aligning the transceiver 10 in the vertical and horizontal planes, the optical receiving axis A of the spatial optical signal is LR and light transmission axis A LT is adjusted to the direction of the communication target. LR and light transmission axis A LT Once the direction of the optical fiber is adjusted to the direction of the communication target, spatial optical communication using a spatial optical signal can be established between the communication target and the communication target.

[0090] (Modification) Next, modified examples of this embodiment will be described with reference to the drawings. Two modified examples will be described below. The following modified examples are merely examples and do not limit the configuration of the modified examples of this embodiment.

[0091] [Variation 1] 22 to 24 are conceptual diagrams for explaining a communication device 1-1 in the present disclosure. The communication device 1-1 of the first modification has a configuration in which a ball lens 11 is suspended from a top plate. FIGS. 22 to 24 are views of the communication device 1-1 as viewed from a side. In FIGS. 22 to 24, the movement of the transceiver 10 in a vertical plane will be explained. The transceiver 10 is placed upside down. Therefore, the optical receiver 12 is located at the top of the paper, and the optical transmitter 15 is located at the bottom of the paper. In FIGS. 22 to 24, the movement of the transceiver 10 in a horizontal plane will not be explained. Also, in FIGS. 22 to 24, the internal configuration of the transceiver 10 will not be explained.

[0092] FIG. 22 shows an example in which the communication target is located on the left. The spatial optical signal S LR The spatial optical signal S transmitted from the light transmitter 15 of the transceiver 10 is collected by the ball lens 11 and received by the light receiver 12 of the transceiver 10. LT is transmitted to the communication target. LR The light transmission axis of the spatial light signal S LT The light receiving axis of the lens is parallel to the lens.

[0093] FIG. 23 shows the spatial optical signal receiving axis A in the vertical plane. LR and light transmission axis A LT In this example, the light receiving axis A of the light receiver 12 of the transceiver 10 faces downward. In response to the control of the communication control unit 13, the vertical rotation mechanism 161 moves the transceiver 10 counterclockwise in the vertical plane (on the paper surface) along a circular orbit with the center of the ball lens 11 as the rotation axis. LR The vertical rotation mechanism 161 moves the transmitter / receiver 10 in a vertical plane so that the light receiving axis A of the receiver 12 always passes through the center of the ball lens 11. LR When the light-transmitting axis A of the light-transmitting device 15 is aligned in the direction of the communication target, LT is aligned in the direction of the communication target. As a result, in the vertical plane, the optical receiving axis A of the spatial optical signal LR and light transmission axis A LT is directed toward the communication target located diagonally below.

[0094] FIG. 25 shows the spatial optical signal receiving axis A in the vertical plane. LR and light transmission axis A LT In this example, the light receiving axis A of the light receiver 12 of the transceiver 10 is directed upward. In response to the control of the communication control unit 13, the vertical rotation mechanism 161 moves the transceiver 10 clockwise along a circular orbit in a vertical plane (on the paper surface) with the center of the ball lens 11 as the rotation axis. LR The vertical rotation mechanism 161 moves the transmitter / receiver 10 in a vertical plane so that the light receiving axis A of the receiver 12 always passes through the center of the ball lens 11. LR When the light-transmitting axis A of the light-transmitting device 15 is aligned in the direction of the communication target, LT is aligned in the direction of the communication target. As a result, in the vertical plane, the optical receiving axis A of the spatial optical signal LR and light transmission axis A LT is directed toward the communication target located diagonally above.

[0095] [Modification 2] 25 to 27 are conceptual diagrams for explaining a communication device 1-2 in the present disclosure. A communication device 1-2 of the second modification has a configuration in which a transceiver 10 and a ball lens 11 are integrated together.

[0096] FIG. 25 is a view of the communication device 1-2 seen from a side perspective. FIG. 25 is a view of the communication device 1-2 seen from a rear perspective. The communication device 1-2 has a ball lens 11, a vertical rotation mechanism 165, a worm wheel 166, a motor 167, and a cylindrical worm 168. The ball lens 11 and the vertical rotation mechanism 165 are integrated. The ball lens 11 and the vertical rotation mechanism 165 are rotatably supported by a support portion 173. The worm wheel 166 is formed along the outer circumferential surface of the vertical rotation mechanism 165. The gear of the worm wheel 166 and the gear of the cylindrical worm 168 are meshed with each other. The cylindrical worm 168 rotates in response to the driving of the motor 167 under the control of the communication control unit 13. The worm wheel 166 rotates on the support portion 173 in accordance with the rotation of the cylindrical worm 168.

[0097] Moreover, the vertical rotation mechanism 165 includes a transmission and reception function similar to that of the transceiver 10 (FIG. 1). The transmission and reception function of the vertical rotation mechanism 165 has a light receiver 12, a communication control unit 13, and a light transmitter 15, similar to that of the transceiver 10 (FIG. 1). In FIG. 25, an example of an area in which the light receiver 12, the communication control unit 13, and the light transmitter 15 are arranged is shown by dashed lines. Note that in FIG. 25, the area in which the light receiver 12, the communication control unit 13, and the light transmitter 15 are arranged (dashed lines) shows their approximate positions and does not show their exact positions.

[0098] In the housing of the vertical rotation mechanism 165, windows are formed in front of the light receiving surface of the light receiver 12 (left side of the drawing) and in front of the transmission surface of the light transmitter 15 (left side of the drawing). For example, a window material made of a material through which the spatial optical signal passes is disposed in the window. For example, the window may be open. In the state of FIG. 25, the receiving surface of the light receiver 12 faces leftward. Also, in the state of FIG. 25, the transmission surface of the light transmitter 15 faces leftward. The light transmission axis A of the spatial optical signal transmitted from the light transmitter 15 LT The light-transmitting axis A of the spatial light signal transmitted from the light transmitter 15 passes under the ball lens 11. LT indicates the light receiving axis A of the light receiving element for communication of the receiver 12 LR It is parallel to the light transmission axis A. LT and receiving axis A LR are always in a parallel relationship. Therefore, by controlling the rotation mechanism 16 so that the light receiving surface of the optical receiver 12 faces the communication target, the transmission direction of the spatial optical signal can be directed toward the communication target.

[0099] FIG. 27 shows the spatial optical signal receiving axis A in the vertical plane. LR and light transmission axis A LT In this example, the light receiving axis A of the light receiver 12 of the vertical rotation mechanism 165 is directed directly upward. In response to the control of the communication control unit 13, the vertical rotation mechanism 165 rotates together with the ball lens 11 in the vertical plane (on the paper surface). LR The communication control unit 13 rotates the vertical rotation mechanism 165 in the vertical plane so that the spatial optical signal S received by the optical receiver 12 always passes through the center of the ball lens 11. LRand the spatial light signal S transmitted from the light transmitter 15. LT The transmission direction of the spatial light signal S is parallel to that of the motor 167 unless the motor 167 is driven. LR and the spatial light signal S transmitted from the light transmitter 15. LT The transmission direction of the vertical rotation mechanism 165 does not change. The configuration of the communication device 1-2 can cover 180 degrees above the vertical rotation mechanism 165. Therefore, the communication device 1-2 is suitable for free-space optical communication with a flying object such as a drone. The communication device 1-2 is also suitable for free-space optical communication with an artificial satellite located in the sky.

[0100] [Communication Device] FIG. 28 is a conceptual diagram showing an example of the configuration of a communication device 100 including multiple communication devices 1. The communication device 100 includes multiple communication devices 1, a base 101, a window 102, and a top plate 103. The multiple communication devices 1 are arranged on the top surface of the base 101. In other words, the communication device 100 includes multiple transceivers arranged on concentric circles in a horizontal plane. In addition, a window 102 that covers the sides of the multiple communication devices 1 is arranged on the top surface of the base 101. A communication control unit (not shown) that controls the multiple communication devices 1 is housed inside the base 101. The communication control unit has the same function as the communication control unit 13. The window 102 is made of a material that transmits light in the wavelength band of the spatial optical signal. For example, the window 102 may be provided with an optical filter that cuts off light that is not in the wavelength band of the spatial optical signal. The top plate 103 is placed on the upper part of the window 102.

[0101] FIG. 29 is a plan view of a communication device 100-1 including four communication devices 1, as viewed from above. The communication device 1 has the same configuration as the communication device 1 (FIGS. 1 to 21). The communication device 1 may include a modified transceiver. The four communication devices 1 are arranged in a circle centered on the wiring hole H. The four communication devices 1 move independently according to the control of the communication control device. The four communication devices 1 independently transmit and receive spatial optical signals S according to the control of the communication control device. LTIf each communication device 1 can cover a transmission and reception range of 90 degrees in a horizontal plane, spatial optical communication using spatial optical signals can be realized between any communication target located in a 360-degree azimuth in the horizontal plane.

[0102] FIG. 30 is a plan view of a communication device 100-2 including three communication devices 1-3, as viewed from above. The communication device 1-3 differs from the communication device 1 (FIGS. 1 to 21) in that it has two transceivers 10. The communication device 1-3 may include a modified transceiver. The three communication devices 1-3 are arranged in a circle centered on the wiring hole H. The three communication devices 1-3 move independently in response to control of the communication control device. The four communication devices 1-3 each independently transmit and receive a spatial optical signal S in response to control of the communication control device. LT If each of the communication devices 1-3 can cover a transmission and reception range of 120 degrees in the horizontal plane, spatial optical communication using spatial optical signals can be realized between any communication target located in a 360-degree azimuth in the horizontal plane.

[0103] (Examples) Next, application examples of the present embodiment will be described with reference to the drawings. In the following application examples, a plurality of communication devices 100 transmit a spatial optical signal S L 31 is a conceptual diagram for explaining this application. In this application example, an example of a communication network (communication system) configured with a plurality of communication devices 100 is given on the top of a pole (pole space) such as a utility pole or a streetlight arranged in a city.

[0104] There are few obstacles in the space above the pole. Therefore, the space above the pole is suitable for installing the communication device 100. In addition, if the communication device 100 is installed at the same height, the spatial optical signal S L The direction of arrival of the spatial light signal S is limited to the horizontal direction. L In a pair of communication devices 100 that transmit and receive a spatial optical signal S LA pair of communication devices 100 may be arranged to transmit and receive spatial optical signals to each other. L When the above communication network is constructed, a communication device 100 located in the middle receives a spatial optical signal S transmitted from another communication device 100. L may be configured to relay the signal to another communication device 100.

[0105] According to this application example, communication using spatial optical signals is possible between a plurality of communication devices 100 arranged in the space above a pole. For example, in response to communication between the communication devices 100, communication by wireless communication may be performed between the communication device 100 and a wireless device or base station installed in an automobile, a house, or the like. For example, the communication device 100 may be connected to the Internet via a communication cable or the like installed on a pole.

[0106] As described above, the communication device of the present embodiment includes a ball lens, a transmitter / receiver, and a rotation mechanism. The ball lens is a spherical lens. The transmitter / receiver includes a receiver, a transmitter, and a communication control unit. The transmitter / receiver is configured by integrating the receiver and transmitter. The receiver has a receiving axis passing through the center of the ball lens. The transmitter has a transmitting axis parallel to the receiving axis. The communication control unit detects the direction of arrival of the spatial optical signal according to the position of reception of the optical signal by the receiver. The communication control unit controls the rotation mechanism to move the transmitter / receiver according to the detected direction of arrival of the spatial optical signal. The communication control unit causes the transmitter to transmit a spatial optical signal directed to a communication target. The rotation mechanism rotatably supports the transmitter / receiver along a circular orbit in the horizontal plane and the vertical plane centered on the ball lens. The rotation mechanism includes a horizontal rotation mechanism and a vertical rotation mechanism. The horizontal rotation mechanism moves the transmitter / receiver along a circular orbit in the horizontal plane centered on the ball lens. The vertical rotation mechanism moves the transmitter / receiver along a circular orbit in a vertical plane centered on the ball lens.

[0107] In the communication device of this embodiment, the light receiving axis and the light transmitting axis of the transmitter / receiver are parallel. In the communication device of this embodiment, the light receiver and the light transmitter are integrated and can rotate in the horizontal plane and the vertical plane around the ball lens. In the communication device of this embodiment, the light receiving axis and the light transmitting axis of the transmitter / receiver are always parallel even if the transmitter / receiver is moved. Therefore, according to this embodiment, spatial optical communication using spatial optical signals can be established with a communication target arranged in any orientation.

[0108] In one aspect of this embodiment, the light receiver has a substrate, a plurality of direction detection light receiving elements, a light guide tube, a communication light receiving element, and a wavelength filter. The substrate has a light receiving surface facing the ball lens and a back surface opposite the light receiving surface. A through hole is opened in the substrate, penetrating the light receiving surface and the back surface. The plurality of direction detection light receiving elements are arranged around the through hole in the light receiving surface of the substrate, with the light receiving portion facing the ball lens. The light guide tube includes a light receiving surface side opening end corresponding to the through hole, and a back surface side opening end opposite the light receiving surface side opening end. The light guide tube is arranged on the back surface side of the substrate in accordance with the through hole. The communication light receiving element is arranged at the back surface side opening end of the light guide tube, with the light receiving portion facing the ball lens. The wavelength filter is arranged in front of the light receiving portion of the plurality of direction detection light receiving elements and the communication light receiving element. The wavelength filter selectively passes light in a wavelength band of the spatial optical signal to be received. The light transmitter includes a light source, a collimator, and a spatial light modulator. The light source emits light. The collimator converts the light emitted from the light source into parallel light. The spatial light modulator includes a modulation section that modulates the parallel light into modulated light. According to this aspect, the arrival direction of the spatial light signal can be detected according to the optical signal received by the multiple direction detection light receiving elements. Also, according to this aspect, the transmission direction of the spatial light signal can be finely adjusted by adjusting a pattern (phase image) set in the modulation section of the spatial light modulator.

[0109] In one aspect of this embodiment, the communication control unit detects the arrival direction of the spatial optical signal according to the light receiving intensity of the optical signal by each of the plurality of direction detecting light receiving elements included in the optical receiver. The communication control unit controls the rotation mechanism to move the transceiver to a position where the light receiving intensity of the optical signal by the plurality of direction detecting light receiving elements becomes uniform. According to this aspect, the transmission and reception direction of the transceiver can be adjusted according to the light receiving intensity of the optical signal by each of the plurality of direction detecting light receiving elements.

[0110] In one aspect of this embodiment, the transceiver has a worm wheel, a cylindrical worm, and a motor. The worm wheel is formed along the outer periphery of the transceiver in a vertical plane. The cylindrical worm is meshed with a gear of the worm wheel. The motor rotates the cylindrical worm under control of the communication control unit. The inner periphery of the transceiver is fixed along the outer periphery of the ball lens in the vertical plane. According to this aspect, the ball lens and the transceiver can be rotated together by driving the motor.

[0111] In one aspect of this embodiment, multiple transceivers with transmitting and receiving optical axes facing in different directions are arranged on concentric circles in a horizontal plane. For example, the multiple transceivers are supported by different rotation mechanisms. For example, at least two transceivers are installed for one rotation mechanism. According to this aspect, a communication device composed of multiple transceivers can be realized. If the communication axes of the multiple transceivers are facing in different directions, communication can be established between multiple communication devices located in the horizontal plane.

[0112] A communication system according to one aspect of the present embodiment includes a plurality of the communication devices described above. The plurality of communication devices are arranged to transmit and receive spatial optical signals to and from each other. According to this aspect, a communication network for transmitting and receiving spatial optical signals can be realized.

[0113] Second embodiment Next, a communication device according to a second embodiment will be described with reference to the drawings. The communication device of this embodiment has a simplified configuration of the communication device of the first embodiment. Fig. 32 is a conceptual diagram showing an example of the configuration of a communication device in the present disclosure. Fig. 32 is a conceptual diagram of the communication device 2 as seen from a side perspective.

[0114] The communication device 2 includes a ball lens 21, a transceiver 20, and a rotation mechanism 26. The ball lens 21 is a spherical lens. The transceiver 20 is configured by integrating a light receiver 22 and a light transmitter 25. The light receiver 22 has a light receiving axis A passing through the center of the ball lens 21. LR The light transmitter 25 has a light receiving axis A LR A beam axis A is parallel to LT Rotation mechanism 26 supports transceiver 20 so that it can rotate along a circular orbit in the horizontal and vertical planes around ball lens 11.

[0115] In the communication device of this embodiment, the light receiving axis and the light transmitting axis of the transmitter / receiver are parallel. In the communication device of this embodiment, the light receiver and the light transmitter are integrated and can rotate in the horizontal plane and the vertical plane around the ball lens. In the communication device of this embodiment, the light receiving axis and the light transmitting axis of the transmitter / receiver are always parallel even if the transmitter / receiver is moved. Therefore, according to this embodiment, spatial optical communication using spatial optical signals can be established with a communication target arranged in any orientation.

[0116] (Hardware) Next, a hardware configuration for executing the control and processing in the present disclosure will be described with reference to the drawings. Here, an information processing device 90 (computer) in Fig. 33 is given as an example of such a hardware configuration. The information processing device 90 in Fig. 33 is an example of a configuration for executing the control and processing in the present disclosure, and does not limit the scope of the present disclosure.

[0117] As shown in Fig. 33, an information processing device 90 includes a processor 91, a main storage device 92, an auxiliary storage device 93, an input / output interface 95, and a communication interface 96. In Fig. 33, the interface is abbreviated as I / F (Interface). The processor 91, the main storage device 92, the auxiliary storage device 93, the input / output interface 95, and the communication interface 96 are connected to each other via a bus 98 so as to be able to communicate data with each other. In addition, the processor 91, the main storage device 92, the auxiliary storage device 93, and the input / output interface 95 are connected to a network such as the Internet or an intranet via the communication interface 96.

[0118] The processor 91 loads a program (instructions) stored in the auxiliary storage device 93 or the like into the main storage device 92. For example, the program is a software program for executing the control and processing in the present disclosure. The processor 91 executes the program loaded into the main storage device 92. The processor 91 executes the program to execute the control and processing in the present disclosure.

[0119] The main memory device 92 has an area in which a program is loaded. The processor 91 loads a program stored in the auxiliary memory device 93 or the like in the main memory device 92. The main memory device 92 is realized by a volatile memory such as a dynamic random access memory (DRAM). Furthermore, a non-volatile memory such as a magneto resistive random access memory (MRAM) may be configured / added to the main memory device 92.

[0120] The auxiliary storage device 93 stores various data such as programs. The auxiliary storage device 93 is realized by a local disk such as a hard disk or a flash memory. Note that it is also possible to configure the main storage device 92 to store various data and omit the auxiliary storage device 93.

[0121] The input / output interface 95 is an interface for connecting the information processing device 90 to peripheral devices based on standards and specifications. The communication interface 96 is an interface for connecting to an external system or device through a network such as the Internet or an intranet based on standards and specifications. The input / output interface 95 and the communication interface 96 may be a common interface for connecting to an external device.

[0122] Input devices such as a keyboard, a mouse, and a touch panel may be connected to the information processing device 90 as necessary. These input devices are used to input information and settings. When a touch panel is used as the input device, a screen having the function of the touch panel becomes the interface. The processor 91 and the input devices are connected via an input / output interface 95.

[0123] The information processing device 90 may be equipped with a display device for displaying information. When the display device is equipped, the information processing device 90 is equipped with a display control device (not shown) for controlling the display of the display device. The information processing device 90 and the display device are connected via an input / output interface 95.

[0124] The information processing device 90 may be provided with a drive device. The drive device mediates between the processor 91 and a recording medium (program recording medium) in reading data and programs stored in the recording medium and writing the processing results of the information processing device 90 to the recording medium. The information processing device 90 and the drive device are connected via an input / output interface 95.

[0125] The above is an example of a hardware configuration for enabling the control and processing in the present disclosure. The hardware configuration in FIG. 33 is an example of a hardware configuration for executing the control and processing in the present disclosure, and does not limit the scope of the present disclosure. A program for causing a computer to execute the control and processing in the present disclosure is also included in the scope of the present disclosure.

[0126] A program recording medium on which a program for executing the processing in this embodiment is recorded is also included in the scope of the present invention. For example, the program recording medium is a computer-readable non-transient recording medium. The recording medium can be realized by an optical recording medium such as a CD (Compact Disc) or a DVD (Digital Versatile Disc). The recording medium may be realized by a semiconductor recording medium such as a USB (Universal Serial Bus) memory or an SD (Secure Digital) card. The recording medium may also be realized by a magnetic recording medium such as a flexible disk or other recording medium.

[0127] The components in the present disclosure may be combined in any manner. The components in the present disclosure may be realized by software. The components in the present disclosure may be realized by a circuit.

[0128] Although the present disclosure has been described above with reference to the embodiments, the present disclosure is not limited to the above-mentioned embodiments. Various modifications that can be understood by a person skilled in the art can be made to the configuration and details of the present disclosure within the scope of the present disclosure. Furthermore, each embodiment can be appropriately combined with other embodiments.

[0129] A part or all of the above-described embodiments can be described as, but is not limited to, the following supplementary notes. (Appendix 1) A ball lens and a transceiver in which a light receiver having a light receiving axis passing through the center of the ball lens and a light transmitter having a light transmitting axis parallel to the light receiving axis are integrated; a rotation mechanism that rotatably supports the transceiver along a circular orbit in a horizontal plane and a vertical plane centered on the ball lens. (Appendix 2) The rotation mechanism includes: a horizontal rotation mechanism that moves the transmitter / receiver along a circular orbit in the horizontal plane centered on the ball lens; and a vertical rotation mechanism that moves the transceiver along a circular orbit in the vertical plane centered on the ball lens. (Appendix 3) The optical receiver includes: a substrate having a light receiving surface facing the ball lens and a back surface opposite to the light receiving surface, the substrate having a through hole penetrating the light receiving surface and the back surface; a plurality of direction detection light receiving elements arranged around the through hole on the light receiving surface of the substrate with a light receiving portion facing the ball lens; a light guide tube including a light receiving surface side opening end corresponding to the through hole and a back surface side opening end opposite to the light receiving surface side opening end, the light guide tube being disposed on the back surface side of the substrate in alignment with the through hole; a communication light receiving element arranged at the rear opening end of the light guiding tube with a light receiving portion facing the ball lens; a wavelength filter disposed in front of the light receiving sections of the plurality of direction detection light receiving elements and the communication light receiving element, and selectively passing light in a wavelength band of a spatial optical signal to be received; The light transmitter comprises: A light source; a collimator that converts the light emitted from the light source into parallel light; and a spatial light modulator including a modulation unit that modulates the parallel light into modulated light. (Appendix 4) 4. The communication device according to claim 3, further comprising a communication control unit that detects a direction of arrival of a spatial optical signal according to a position where the optical signal is received by the optical receiver, controls the rotation mechanism to move the transmitter / receiver according to the detected direction of arrival of the spatial optical signal, and causes the optical transmitter to transmit a spatial optical signal directed to a communication target. (Appendix 5) The communication control unit detecting a direction of arrival of the spatial optical signal according to a light receiving intensity of the optical signal by each of the plurality of direction detecting light receiving elements included in the optical receiver; 5. The communication device according to claim 4, wherein the rotation mechanism is controlled to move the transmitter / receiver to a position where the received light intensities of the optical signals by the plurality of direction detecting light receiving elements are uniform. (Appendix 6) The transceiver includes: a worm wheel formed along an outer periphery of the transceiver in the vertical plane; a cylindrical worm meshed with a gear of the worm wheel; a motor that rotates the cylindrical worm in response to control of the communication control unit, 5. The communication device of claim 4, wherein an inner circumference of the transceiver is fixed along an outer circumference of the ball lens in the vertical plane. (Appendix 7) 2. The communication device according to claim 1, wherein a plurality of the transmitters / receivers, whose transmitting and receiving optical axes are oriented in different directions, are arranged on concentric circles in a horizontal plane. (Appendix 8) 8. The communication device of claim 7, wherein the multiple transceivers are supported by different rotation mechanisms. (Appendix 9) A communication device as described in Appendix 7, wherein at least two of the transceivers are installed for one of the rotation mechanisms. (Appendix 10) A plurality of communication devices according to any one of claims 1 to 9, A plurality of the communication devices, A communication system arranged to transmit and receive spatial optical signals to and from each other. [Explanation of symbols]

[0130] 1, 2 Communication equipment 10, 20 Transmitter 11, 21 Ball lens 12, 22 Receiver 13 Communication control section 15, 25 Light transmitter 16 Rotation mechanism 100 Communication equipment 101 Pedestal 102 Windows 103 Tabletop 121 Substrate 122 Direction detection light receiving element 124 Light guide tube 125 Communication photodetector 127 Wavelength Filter 131 Drive unit 132 Transmission control section 133 Receiving circuit 135 Communications Department 141 Detector 143 Amplifier 144 Detector 145 Integrator 146 ADC 147 Direction detection unit 151 Light source 152 Collimator 153 Spatial Light Modulator 154 Plane mirror 155 Concave mirror 161 Vertical Rotation Mechanism 162 Horizontal rotation mechanism 165 Vertical Rotation Mechanism 166 Worm Wheel 167 Motor 168 Cylindrical worm 171, 173 Support part

Claims

1. A ball lens and a transceiver in which a light receiver having a light receiving axis passing through the center of the ball lens and a light transmitter having a light transmitting axis parallel to the light receiving axis are integrated; a rotation mechanism that rotatably supports the transceiver along a circular orbit in a horizontal plane and a vertical plane centered on the ball lens.

2. The rotation mechanism includes: a horizontal rotation mechanism that moves the transmitter / receiver along a circular orbit in the horizontal plane centered on the ball lens; 2. The communication device according to claim 1, further comprising a vertical rotation mechanism that moves the transceiver along a circular orbit in the vertical plane with the ball lens as a center.

3. The optical receiver includes: a substrate having a light receiving surface facing the ball lens and a back surface opposite to the light receiving surface, the substrate having a through hole penetrating the light receiving surface and the back surface; a plurality of direction detection light receiving elements arranged around the through hole on the light receiving surface of the substrate with a light receiving portion facing the ball lens; a light guide tube including a light receiving surface side opening end corresponding to the through hole and a back surface side opening end opposite to the light receiving surface side opening end, the light guide tube being disposed on the back surface side of the substrate in alignment with the through hole; a communication light receiving element arranged at the rear opening end of the light guiding tube with a light receiving portion facing the ball lens; a wavelength filter disposed in front of the light receiving sections of the plurality of direction detection light receiving elements and the communication light receiving element, and selectively passing light in a wavelength band of a spatial optical signal to be received; The light transmitter comprises: A light source; a collimator that converts the light emitted from the light source into parallel light; The communication device according to claim 2 , further comprising: a spatial light modulator including a modulation section that modulates the parallel light into modulated light.

4. 4. The communication device according to claim 3, further comprising a communication control unit that detects a direction of arrival of the spatial optical signal according to a position of reception of the optical signal by the optical receiver, controls the rotation mechanism to move the transmitter / receiver according to the detected direction of arrival of the spatial optical signal, and causes the optical transmitter to transmit a spatial optical signal directed to a communication target.

5. The communication control unit detecting a direction of arrival of the spatial optical signal according to a light receiving intensity of the optical signal by each of the plurality of direction detecting light receiving elements included in the optical receiver; 5. The communication device according to claim 4, wherein the rotation mechanism is controlled to move the transmitter / receiver to a position where the light receiving intensities of the optical signals received by the plurality of direction detecting light receiving elements become uniform.

6. The transceiver includes: a worm wheel formed along an outer periphery of the transceiver in the vertical plane; a cylindrical worm meshed with a gear of the worm wheel; a motor that rotates the cylindrical worm in response to control of the communication control unit, 5. The communication device according to claim 4, wherein an inner periphery of the transceiver is fixed along an outer periphery of the ball lens in the vertical plane.

7. 2. The communication device according to claim 1, wherein a plurality of said transmitters / receivers, whose optical transmission / reception axes are oriented in different directions, are arranged on concentric circles in a horizontal plane.

8. The communication device according to claim 7 , wherein the plurality of transceivers are supported by different rotation mechanisms.

9. The communication device according to claim 7 , wherein at least two of the transceivers are provided for one of the rotating mechanisms.

10. A communication device according to any one of claims 1 to 9, A plurality of the communication devices, A communication system arranged to transmit and receive spatial optical signals to and from each other.

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