Receiving device and communication device

Abstract

To provide a receiving device and the like that can achieve a 360-degree communication angle.SOLUTION: A receiving device includes a ball lens, at least one light receiver, and a support supporting the light receiver movably around the ball lens. The light receiver includes a substrate having a first surface facing the ball lens and a second surface opposite to the first surface and having a through hole penetrating the first surface and the second surface, a plurality of light receiving elements for integration arranged around the through hole on the first surface of the substrate, with a light receiving portion facing the ball lens, a light guide tube including a first opening end aligned with the through hole and a second opening end opposite to the first opening end and arranged on the side of the second surface associated with the through hole, and a light receiving element for communication arranged on the second opening end of the light guide tube, with a light receiving portion facing the ball lens.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] In free space optical communication, signal light (hereinafter also referred to as spatial optical signal) propagating through space is transmitted and received without using a medium such as optical fiber. Compared to the radio waves used in wireless communication, the spatial optical signal used in optical space communication is highly directional. Furthermore, the spatial optical signal does not interfere with radio waves. In the field of spatial optical communication, an optical communication network can be constructed using optical communication devices facing each other. Since the spatial optical signal is highly directional, communication will be interrupted if the spatial optical signal is physically blocked by an obstruction. Therefore, in order to realize a stable optical communication environment in spatial optical communication, a redundant optical communication network with simultaneous multi-directional connections is required.

[0003] Patent Document 1 discloses an optical wireless device that transmits and receives signal light between a master unit and a slave unit (a communication target). The master unit has a plurality of transmitting and receiving elements and a designation means. The plurality of transmitting and receiving elements are arranged in close proximity to one another. The plurality of transmitting and receiving elements transmit and receive signal light with the slave unit. The designation means designates an optimal transmitting and receiving element based on the signal light from the slave unit. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2005-191696 A Summary of the Invention [Problem to be solved by the invention]

[0005] In the method of Patent Document 1, a transmitting / receiving element to be used for communication with a slave unit is designated based on signal light received by a plurality of transmitting / receiving elements. According to the method of Patent Document 1, communication is established by transmitting and receiving signal light with a communication target. However, in the method of Patent Document 1, depending on the incident direction of the signal light with respect to the light receiving surface of the transmitting / receiving element, the transmitting / receiving element does not receive signal light of sufficient intensity, and communication with the communication target cannot be established. In other words, the method of Patent Document 1 cannot realize a communication angle of 360 degrees.

[0006] An object of the present disclosure is to provide a receiving device, a receiving device and a communication device that can achieve a communication angle of 360 degrees. [Means for solving the problem]

[0007] A receiving device according to an embodiment of the present disclosure includes a ball lens, at least one light receiver, and a support supporting the light receiver movably around the ball lens. The light receiver includes a substrate having a first surface facing the ball lens and a second surface opposite to the first surface and having a through hole penetrating the first surface and the second surface, a plurality of integral light receiving elements arranged around the through hole on the first surface of the substrate with a light receiving portion facing the ball lens, a light guide tube including a first opening end aligned with the through hole and a second opening end opposite to the first opening end and arranged on the side of the second surface corresponding to the through hole, and a communication light receiving element arranged at the second opening end of the light guide tube with a light receiving portion facing the ball lens. Effect of the Invention

[0008] According to the present disclosure, it is possible to provide a receiving device and a communication device that can achieve a communication angle of 360 degrees. [Brief description of the drawings]

[0009] [Figure 1] 1 is a conceptual diagram illustrating an example of a configuration of a receiving device according to the present disclosure. [Diagram 2] 2 is a side view showing an example of a configuration of a light receiver included in a receiving device according to the present disclosure. FIG. [Diagram 3]1 is a perspective view showing an example of a configuration of a light receiver included in a receiving device according to the present disclosure. [Figure 4] 1 is a conceptual diagram for explaining an example of a trajectory of signal light focused by a ball lens included in a receiving device in the present disclosure. FIG. [Diagram 5] 1 is a conceptual diagram for explaining an example of how signal light collected by a ball lens included in a receiving device in the present disclosure is incident on a light receiver. FIG. [Figure 6] 11 is a conceptual diagram for explaining another example of a state in which signal light collected by a ball lens included in a receiving device in the present disclosure is incident on a light receiver. FIG. [Figure 7] 1 is a conceptual diagram illustrating an example of reception of a spatial optical signal for wide scanning transmitted from a communication target by a receiving device according to the present disclosure. [Figure 8] 1 is a conceptual diagram illustrating an example of a focusing range of signal light focused by a ball lens included in a receiving device in the present disclosure. [Figure 9] 1 is a conceptual diagram illustrating an example of reception of a spatial optical signal for narrow scanning transmitted from a communication target by a receiving device according to the present disclosure. [Figure 10] 1 is a conceptual diagram illustrating an example of a focusing range of signal light focused by a ball lens included in a receiving device in the present disclosure. [Figure 11] 1 is a conceptual diagram showing a light receiving surface of a light receiver included in a receiving device according to the present disclosure, as viewed from the viewpoint of a ball lens. [Figure 12] 1 is a conceptual diagram showing a light receiving surface of a light receiver included in a receiving device according to the present disclosure, as viewed from the viewpoint of a ball lens. [Figure 13] 11 is a conceptual diagram showing an example in which the number of integrating light-receiving elements included in a light receiver provided in a receiving device according to the present disclosure is increased. [Figure 14] 10 is a conceptual diagram showing an example in which an integrating light-receiving element included in a light receiver provided in a receiving device in the present disclosure is enlarged. FIG. [Figure 15] 1 is a perspective view illustrating an example of a light receiver included in a receiving device according to the present disclosure. [Figure 16]2 is a side view illustrating an example of a light receiver included in a receiving device according to the present disclosure. FIG. [Figure 17] 1 is a perspective view illustrating an example of a light receiver included in a receiving device according to the present disclosure. [Figure 18] 1 is a block diagram showing an example of a configuration of a communication device according to the present disclosure. [Figure 19] 2 is a perspective view of an internal configuration of a transmission device included in a communication device according to the present disclosure. FIG. [Figure 20] 2 is a side view of an internal configuration of a transmitting device included in a communication device according to the present disclosure. [Figure 21] 1 is a conceptual diagram for explaining a transmission pattern of a search spatial optical signal transmitted from a transmitting device included in a communication device in the present disclosure. [Figure 22] 2 is a block diagram showing an example of a configuration of a control unit included in a receiving device provided in a communication device according to the present disclosure. FIG. [Figure 23] 11 is a conceptual diagram showing an example of changing the position of a light receiver according to the intensity of signal light received by a plurality of integrating light receiving elements included in a receiving device provided in a communication device according to the present disclosure. FIG. [Figure 24] 1 is a conceptual diagram showing an example of changing the transmission direction of a spatial optical signal transmitted from a transmitting device included in a communication device in the present disclosure. [Diagram 25] 1 is a conceptual diagram for explaining an example of transmission of a scanning spatial optical signal by a transmission device included in a communication device in the present disclosure. [Figure 26] 1 is a diagram for explaining an example of a transmission pattern of a spatial optical signal transmitted from a transmitting device included in a communication device in the present disclosure. [Figure 27] FIG. 1 is a conceptual diagram for explaining an example of establishing communication between communication devices in the present disclosure. [Figure 28] 1 is a conceptual diagram for explaining a process of optimizing a transmission direction of a spatial optical signal transmitted from a transmitting device included in a communication device in the present disclosure. [Figure 29]1 is a conceptual diagram for explaining an example of identifying the position of a communication target using communication light transmitted from a transmitting device included in a communication device in the present disclosure. [Diagram 30] 11 is a flowchart for explaining an example of control of a receiving device by a communication control device included in a communication device in the present disclosure. [Diagram 31] 11 is a flowchart for explaining an example of control of a transmission device by a communication control device included in a communication device in the present disclosure. [Diagram 32] 1 is a conceptual diagram illustrating an example of a configuration of a receiving device according to the present disclosure. [Diagram 33] 2 is a side view showing an example of a configuration of a light receiver included in a receiving device according to the present disclosure. FIG. [Diagram 34] 1 is a perspective view showing an example of a configuration of a light receiver included in a receiving device according to the present disclosure. [Diagram 35] 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 invention will be described with reference to the drawings. However, the embodiments described below are limited in a manner that is technically preferable for carrying out the present invention, but the scope of the invention is not limited to the following. In addition, in all the drawings used to explain the following embodiments, the same reference numerals are used for similar parts unless otherwise specified. In addition, in the following embodiments, repeated explanations 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 receiving device 10 in the present disclosure. Fig. 1 is a conceptual diagram looking down on the receiving device 10 from a viewpoint diagonally above. The receiving device 10 includes a ball lens 11, a photoreceiver 12, a support 18, a control unit 19, and a base 180. The receiving device 10 also has a driver (not shown) that changes the angle of the light receiving surface of the photoreceiver 12 and the position of the support 18. For example, the driver is realized by a small motor such as a microstepping motor.

[0014] A circular track R is arranged on the upper surface of the base 180. The lower end of a support pillar 18 is movably arranged on the circular track R. By moving the support pillar 18 along the circular track R, the position of the optical receiver 12 in the horizontal plane can be adjusted. The support pillar 18 along the circular track R is adjusted by the control unit 19 controlling the drive of a driver (not shown).

[0015] Optical receiver 12 is disposed on the upper end of support 18. The light receiving surface of optical receiver 12 faces ball lens 11. For example, receiving device 10 is configured so that the position of optical receiver 12 in the vertical direction can be changed along the circumference of ball lens 11. For example, it is preferable that optical receiver 12 is disposed so that the light receiving surface of optical receiver 12 can be changed along the circumference of ball lens 11. For example, receiving device 10 may be configured so that the position of optical receiver 12 in the vertical direction can be changed by extending or contracting support 18.

[0016] The ball lens 11 is a spherical lens. The ball lens 11 is an optical element that collects a spatial optical signal (communication light, notification light) arriving from the outside. The ball lens 11 is spherical when viewed from any angle. The ball lens 11 collects the incident spatial optical signal. The light (also called signal light) originating from the spatial optical signal collected by the ball lens 11 is collected toward the light collecting area of ​​the ball lens 11. Since the ball lens 11 is spherical, it collects the spatial optical signal arriving from any direction. That is, the ball lens 11 exhibits the same light collecting performance for the spatial optical signal arriving from any 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 collected toward the light collecting area.

[0017] 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, materials such as glass, crystal, and resin that transmit / refract 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.

[0018] 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.

[0019] Optical receiver 12 is supported by support 18 and disposed in a light collection region including the light collection point of ball lens 11. The light collection point of ball lens 11 is not uniquely determined. Therefore, optical receiver 12 is disposed in a light collection region including the light collection point of ball lens 11. In the example of FIG. 1, optical receiver 12 is disposed to the side of ball lens 11. The light receiving surface of optical receiver 12 is disposed toward the center of ball lens 11.

[0020] 2 and 3 are conceptual diagrams showing an example of the configuration of the optical receiver 12. FIG. 2 is a side view of the optical receiver 12 seen from a lateral perspective. FIG. 3 is a perspective view of the light receiving surface of the optical receiver 12 seen from diagonally above. The optical receiver 12 has a substrate 121, an integrating light receiving element 122, a light guide tube 124, a communication light receiving element 125, and a filter 127. The optical receiver 12 has a plurality of integrating light receiving elements 122. In the example of FIGS. 2 and 3, the optical receiver 12 has four integrating light receiving elements 122. The number of integrating light receiving elements 122 is not limited to four.

[0021] 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 integrating light receiving elements 122 are arranged around the through hole A. In the example of FIGS. 2 and 3, four integrating light receiving elements 122 are arranged around the through hole A.

[0022] The plurality of integral light receiving elements 122 are disposed on a first surface (the surface on the left side in FIG. 2) of the substrate 121. The plurality of integral 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 integral light receiving element 122 is directed to the ball lens 11 via the filter 127. The integral 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 integral light receiving element 122 is realized by a photodiode that has sensitivity to infrared light. For example, the integral 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 integral 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. Therefore, the integrating light receiving element 122 may be realized by a germanium (Ge)-based or silicon (Si)-based photodiode. The spatial optical signal received by the integrating light receiving element 122 is converted into an electric signal. The converted electric signal is output to the control unit 19. The converted electric signal is supplied to an integrator (not shown) included in the control unit 19. The electric signal supplied to the integrator is integrated up to a level that can be detected by the control unit 19.

[0023] 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 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 control unit 19.

[0024] The filter 127 is a wavelength filter through which light in the wavelength band of the spatial optical signal to be received passes. The filter 127 passes light in the wavelength band of the spatial optical signal to be received by the integration light receiving element 122 or the communication light receiving element 125 arranged in the downstream. The filter 127 blocks light that is not to be received. The main purpose of the filter 127 is to reduce the influence of sunlight. In an environment with little influence of sunlight or external light, the filter 127 may be omitted.

[0025] FIG. 4 is a conceptual diagram for explaining an example of a trajectory of light focused by ball lens 11. FIG. 4 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 communication light receiving element 125 is disposed near position b. Therefore, the light receiving efficiency of signal light by communication light receiving element 125 is improved. In other words, light receiving section 126 of communication light receiving element 125 is disposed in accordance with position b. In contrast, integrating light receiving element 122 is disposed at a position closer to ball lens 11 than communication light receiving element 125.

[0026] Fig. 5 is a conceptual diagram showing an example of how signal light collected by ball lens 11 enters optical receiver 12. Fig. 5 shows a cross-sectional view of optical receiver 12 seen from a side perspective. In the example of Fig. 5, signal light collected by ball lens 11 is irradiated onto light receiving unit 126 of communication light receiving element 125. In the example of Fig. 5, an electrical signal based on the signal light received by communication light receiving element 125 is processed by control unit 19.

[0027] The control unit 19 receives an electrical signal based on the signal light received by the plurality of integration light receiving elements 122 and the communication light receiving element 125. The control unit 19 decodes the received electrical signal. For example, the control unit 19 is realized by a microcomputer including a processor and a memory. In response to the received electrical signal, the control unit 19 drives a first actuator (not shown) that changes the angle of the light receiving surface of the light receiver 12 and a second actuator (not shown) that changes the position of the support 18, thereby adjusting the angle of the light receiving surface of the light receiver 12 and the position of the support 18. For example, the first actuator and the second actuator are realized by small motors such as microstepping motors.

[0028] Control unit 19 adjusts the angle of the light receiving surface of receiver 12 and the position of support 18 according to the intensity of the signal light received by each of the plurality of integrating light receiving elements 122. Control unit 19 aligns the position of light receiving unit 126 of communication light receiving element 125 with the position of the focusing point of the signal light focused by ball lens 11. To this end, control unit 19 moves the angle of the light receiving surface of receiver 12 and the position of support 18 toward the integrating light receiving element 122 with the greatest receiving intensity according to the intensity of the signal light received by each of the plurality of integrating light receiving elements 122.

[0029] FIG. 6 is a conceptual diagram showing another example of the state in which the signal light collected by ball lens 11 is incident on optical receiver 12. FIG. 6 shows a cross-sectional view of optical receiver 12 as seen from a side perspective. In the example of FIG. 6, the signal light collected by ball lens 11 is not irradiated to light receiving portion 126 of communication light receiving element 125, but is irradiated by light receiving portion 123 of integration light receiving element 122. In the example of FIG. 6, the position of optical receiver 12 needs to be changed. Control unit 19 changes the position of optical receiver 12 according to the position of integration light receiving element 122 that has received the signal light. In the example of FIG. 6, control unit 19 moves optical receiver 12 upward.

[0030] FIG. 7 is a conceptual diagram showing an example of receiving a spatial optical signal for wide scanning transmitted from a communication target T. FIG. 7 shows an example in which a spatial optical signal for wide scanning is transmitted from a communication target T. FIG. 8 shows a focusing range R1 of the signal light focused by the ball lens 11 in the example of FIG. 7. In FIG. 8, numbers (1 to 4) are added to the end of the reference symbols representing the light receiving units 123 of the multiple integrating light receiving elements 122 to distinguish them from each other. In the example of FIG. 8, the light receiving units 123-2 and 123-3 are included in the focusing range R1.

[0031] FIG. 9 is a conceptual diagram showing an example of receiving a spatial optical signal for narrow scanning transmitted from a communication target T. FIG. 9 is an example of transmitting a spatial optical signal for narrow scanning from a communication target T. FIG. 10 shows a light collection range R1 of the signal light collected by the ball lens 11 in the example of FIG. 9. In FIG. 10, numbers (1 to 4) are added to the end of the reference characters representing the light receiving units 123 of the plurality of integral light receiving elements 122 to distinguish them from each other. As in the example of FIG. 8, in the example of FIG. 10, the light receiving units 123-2 and 123-3 are included in the light collection range R1. In this way, once the positional relationship between the two devices is determined, the position of the light collection range of the signal light is uniquely determined. Note that, compared to the wide scan, the narrow scan narrows the search range of the spatial optical signal, so the intensity of the signal light collected by the ball lens 11 is stronger.

[0032] FIG. 11 is a conceptual diagram of the light receiving surface of light receiver 12 as viewed from the viewpoint of ball lens 11. FIG. 11 shows the positional relationship between light receiving section 123 of integration light receiving element 122 and light receiving section 126 of communication light receiving element 125. In FIG. 11, numbers (1 to 4) are added to the end of the reference characters representing light receiving sections 123 of the multiple integration light receiving elements 122 to distinguish them from one another. FIG. 11 also shows the inside of light guide tube 124. Multiple light receiving sections 123-1 to 4 are arranged on a circumference centered on light receiving section 126 of communication light receiving element 125. FIG. 11 shows an example of the light collecting range of light collected by ball lens 11 as a circle.

[0033] The signal light irradiated to the light-collecting range R2 (dashed line) is received by the light-receiving unit 126, the light-receiving unit 123-3, and the light-receiving unit 123-4 of the communication light-receiving element 125. Depending on the intensity of the signal light received by the light-receiving unit 126, the light-receiving unit 123-3, and the light-receiving unit 123-4, the control unit 19 moves the position of the light receiver 12 to the lower left.

[0034] The signal light irradiated onto the light-collecting range R3 (dash-dotted line) is received by the light-receiving unit 123-4. In response to the intensity of the signal light received by the light-receiving unit 123-4, the control unit 19 moves the position of the light receiver 12 to the left.

[0035] The signal light irradiated to the light-collecting range R4 (two-dot chain line) is received by the light-receiving units 123-2 and 123-3. In response to the intensities of the signal lights received by the light-receiving units 123-2 and 123-3, the control unit 19 moves the position of the light receiver 12 to the lower right.

[0036] 12 to 14 are conceptual diagrams showing examples of signal light receiving conditions according to the number and size of integrating light receiving elements 122. Figs. 12 to 14 are views seen from the viewpoint of ball lens 11. In the examples of Figs. 12 to 14, signal light collected by ball lens 11 is irradiated onto collection range R5.

[0037] FIG. 12 shows the configuration of the light receiver 12 described above. FIG. 12 shows the light receiving section 123 of the integrating light receiving element 122, the light receiving section 126 of the communication light receiving element 125, and the inside of the light guide tube 124. In the example of FIG. 12, there are four light receiving sections 123. In FIG. 12, numbers (1 to 4) are added to the end of the reference characters representing the light receiving sections 123 of the multiple integrating light receiving elements 122 to distinguish them from one another. In the example of FIG. 12, the signal light irradiated to the light collection range R5 is received by one light receiving section 123-4 arranged on the left side.

[0038] FIG. 13 shows an example in which the number of integrating light receiving elements 122 is increased. FIG. 13 shows light receiving sections 123-1 to 8 of the integrating light receiving element 122, light receiving section 126 of the communication light receiving element 125, and the inside of the light guide tube 124. The example in FIG. 13 shows an example in which there are eight integrating light receiving elements 122. In FIG. 13, numbers (1 to 8) are added to the end of the reference symbols representing the multiple light receiving sections 123 to distinguish them from one another. In the example in FIG. 13, the signal light irradiated to the light collecting range R5 is received by the light receiving section 123-4 and the light receiving section 123-8. In the configuration in FIG. 13, the signal light irradiated to the same light collecting range R5 as in FIG. 12 can be received by two integrating light receiving elements 122.

[0039] FIG. 14 shows an example in which an integrating light receiving element 128 is disposed instead of the integrating light receiving element 122. Compared to the integrating light receiving element 122, the integrating light receiving element 128 is an element having a larger light receiving area. In FIG. 14, the reference numerals representing the plurality of integrating light receiving elements 128 are suffixed with numbers (1 to 8) to distinguish each from the other. In the example of FIG. 14, the signal light irradiated to the same light collecting range R5 as in FIG. 12 can be received by the two integrating light receiving elements 128-1 and 128-4. Also, in the example of FIG. 14, the signal light irradiated to the same light collecting range R5 as in FIG. 13 can be received over a wider area.

[0040] (Modification) Next, modified examples of the optical receiver 12 included in the receiving device 10 according to the present disclosure will be described. Two modified examples will be given below.

[0041] [Variation 1] FIG. 15 is a conceptual diagram showing an example of the optical receiver 12-1 according to the first modification. FIG. 15 is a view of the light receiving surface of the optical receiver 12-1 as seen from an obliquely upward viewpoint. The optical receiver 12-1 is provided with an integral light receiving element 122-1 instead of the integral light receiving element 122. For example, a germanium photodiode can be applied to the integral light receiving element 122-1. Compared with an InGaAs photodiode, the germanium photodiode can be set to have a larger light receiving area at a lower cost. In addition, the optical receiver 12-1 is provided with a filter 127-1 that selectively passes light in a wavelength band to which the InGaAs photodiode and the germanium photodiode have sensitivity. According to this modification, the light receiving area of ​​the integral light receiving element 122-1 can be increased.

[0042] [Modification 2] 16 and 17 are conceptual diagrams showing an example of the optical receiver 12-2 according to the second modification. FIG. 16 is a side view of the optical receiver 12-2 seen from a lateral viewpoint. FIG. 17 is a view of the light receiving surface of the optical receiver 12-2 seen from a diagonally upward viewpoint. The optical receiver 12-2 is provided with an integral optical receiver 122-2 instead of the integral optical receiver 122. The integral optical receiver 122-2 and the communication optical receiver 125 are sensitive to different wavelength bands. For example, a silicon photodiode can be used for the integral optical receiver 122-2. The silicon photodiode is sensitive to a wavelength band in the vicinity of 850 nanometers (nm). On the other hand, the InGaAs photodiode and the germanium photodiode are sensitive to a wavelength band in the vicinity of 1550 nm. The optical receiver 12-2 is provided with a filter 127-2 that selectively passes light in a wavelength band to which the silicon photodiode is sensitive. Filter 127-2 is set to a shape and size that matches the light receiving surface of photoreceiver 12-2. In addition, filter 127-3 that selectively passes light in a wavelength band to which the InGaAs photodiode is sensitive is disposed in photoreceiver 12-2. Filter 127-3 is set to a shape and size that matches the first opening end of light guide tube 124. According to this modification, photodiodes sensitive to different wavelength bands can be applied to integral light receiving element 122-2 and communication light receiving element 125.

[0043] As described above, the receiving device of this embodiment includes a ball lens, at least one light receiver, a support, and a control unit. The light receiver includes a substrate, a plurality of light receiving elements for integration, a light guide tube, and a light receiving element for communication. The substrate has a first surface facing the ball lens and a second surface facing the first surface. A through hole is formed in the substrate, penetrating the first surface and the second surface. The plurality of light receiving elements for integration are arranged around the through hole in the first surface of the substrate, with the light receiving portion facing the ball lens. The light guide tube includes a first opening end corresponding to the through hole and a second opening end facing the first opening end. The light guide tube is arranged on the second surface side of the substrate in line with the through hole. The light receiving element for communication is arranged at the second opening end of the light guide tube, with the light receiving portion facing the ball lens. The support supports the light receiver movably around the ball lens. The control unit receives an electrical signal based on the signal light received by the plurality of integration light receiving elements and the communication light receiving element. The control unit adjusts the angle of the light receiving surface of the light receiver and the position of the support in response to the received electrical signal. The control unit adjusts the angle of the light receiving surface of the light receiver and the position of the support in response to the intensity of the signal light received by each of the plurality of integration light receiving elements, thereby adjusting the position of the light receiving part of the communication light receiving element to match the focusing position of the signal light focused by the ball lens.

[0044] According to the receiving device of this embodiment, the light receiving surface of the light receiving device can be oriented in a 360-degree direction by moving the light receiving device around the ball lens. The receiving device of this embodiment adjusts the position of the light receiving part of the communication light receiving element to match the focusing position of the signal light focused by the ball lens according to the intensity of the signal light received by each of the multiple integration light receiving elements. That is, according to this embodiment, a communication angle of 360 degrees can be realized.

[0045] In one aspect of this embodiment, the plurality of integrating light receiving elements are arranged in a point-symmetrical positional relationship with respect to the center of the through hole. The light receiving portion of the communication light receiving element is arranged to match the focusing point of the ball lens. According to this aspect, the communication light receiving element is arranged at the position of the focusing point where the intensity of the signal light focused by the ball lens is strong, thereby improving the efficiency of receiving the signal light by the communication light receiving element.

[0046] In one aspect of this embodiment, the multiple integrating light receiving elements are arranged in a point-symmetrical positional relationship with respect to the center of the through hole. The control unit moves the angle of the light receiving surface of the light receiver and the position of the support toward the integrating light receiving element with the greater received intensity, depending on the intensity of the signal light received by each of the multiple integrating light receiving elements. According to this aspect, the position of the communication light receiving element can be moved toward the center of the light collecting area formed by the ball lens, depending on the intensity of the signal light received by each of the multiple integrating light receiving elements. Therefore, according to this aspect, the light receiving efficiency of the signal light by the communication light receiving element can be improved.

[0047] In one aspect of this embodiment, filters that selectively pass light in a wavelength band of the spatial optical signal to be received are arranged in association with the light receiving sections of the plurality of integration light receiving elements and the communication light receiving element. According to this aspect, it is possible to selectively supply signal light in a wavelength band to which each light receiving element is sensitive to the light receiving sections of the plurality of integration light receiving elements and the communication light receiving element. According to this aspect, an optical signal from which disturbing light such as sunlight is removed is supplied, thereby improving the light receiving efficiency of the integration light receiving element and the communication light receiving element.

[0048] In one aspect of this embodiment, the integration light receiving element and the communication light receiving element are light receiving elements sensitive to light in different wavelength bands. For example, a relatively inexpensive silicon-based or germanium-based photodiode can be used for the integration light receiving element, and a high-performance InGaAs-based photodiode can be used for the communication light receiving element. With this configuration, the cost of the light receiving device can be reduced.

[0049] Second embodiment Next, a communication device according to a second embodiment will be described with reference to the drawings. The communication device according to this embodiment includes the receiving device according to the first embodiment. In the following, an example will be given in which the communication device according to this embodiment includes a transmitting device having a spatial light modulator. The communication device according to this embodiment may have a light transmitting function other than the spatial light modulator.

[0050] (composition) 18 is a block diagram showing an example of the configuration of a communication device 2 in the present disclosure. The communication device 2 includes a receiving device 20, a transmitting device 27, and a communication control device 28. The receiving device 20 has a similar configuration to the receiving device 10 of the first embodiment. Therefore, in the following, a description of the receiving device 20 will be simplified.

[0051] 19 and 20 are conceptual diagrams showing an example of the configuration of the transmitting device 27. FIG. 19 is a diagram showing the internal configuration of the transmitting device 27 from a diagonally upward viewpoint. FIG. 20 is a diagram showing the inside of the housing 270 of the transmitting device 27 from a side viewpoint. The transmitting device 27 has a light source 271, a spatial light modulator 272, and a light-transmitting mirror 273. An opening through which the projected light 203 passes is formed in a part of the side surface of the housing 270. A window made of a material through which light in the wavelength band of the spatial light signal to be transmitted passes may be formed in the opening portion. FIG. 19 and FIG. 20 are conceptual diagrams showing the transmitting device 27, and do not accurately show the arrangement and positional relationship of the components included in the transmitting device 27.

[0052] The light source 271 is disposed on the lower surface of a top plate 276 disposed on the upper part of the housing 270, with the emission surface facing downward. The emission surface of the light source 271 faces a modulation section 2720 of the spatial light modulator 272 disposed below. The light source 271 may be disposed inside a through hole (not shown) formed in the top plate 276. The light source 271 may be disposed above the through hole formed in the top plate 276.

[0053] The light source 271 includes at least one emitter (not shown). The at least one emitter emits illumination light 201 in response to control of the communication control device 28. The illumination light 201 emitted from the light source 271 is irradiated onto a modulation section 2720 of the spatial light modulator 272. For example, each of the multiple emitters is associated with at least one of multiple modulation regions set in the modulation section 2720 of the spatial light modulator 272. The illumination light 201 emitted from each of the multiple emitters travels toward the associated modulation region.

[0054] For example, the light source 271 includes a plurality of emitters that emit illumination light 201 in the same wavelength band. For example, the light source 271 may be 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 271 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 271 may be a combination of an emitter that emits illumination light 201 in a wavelength band used for communication with a communication target and an emitter that emits light in a wavelength band different from the illumination light 201. 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 the search emitter (850 nm), and when the search is complete, it is possible to switch to communication using the communication emitter (1550 nm).

[0055] For example, the emitter included in the light source 271 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.

[0056] The spatial light modulator 272 is a phase modulation type spatial light modulator. The spatial light modulator 272 has a modulation section 2720. The spatial light modulator 272 is disposed below the light source 271. In the example of FIG. 19, the spatial light modulator 272 is disposed on the upper surface of the bottom plate 277. The spatial light modulator 272 is disposed at a position where the modulated light 202 obtained by modulating the illumination light 201 emitted from the light source 271 is reflected toward the reflection surface 2730 of the light sending mirror 273. The traveling direction of the modulated light 202 is controlled according to the set pattern (phase image) of the modulation section 2720.

[0057] For example, the spatial light modulator 272 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 272 can be realized by LCOS (Liquid Crystal on Silicon). The spatial light modulator 272 may also be realized by MEMS (Micro Electro Mechanical System). In the phase modulation type spatial light modulator 272, the energy can be concentrated on the image portion by operating to sequentially switch the portion used for projecting the projection light 203. Therefore, when the phase modulation type spatial light modulator 272 is used, if the output of the emitter included in the light source 271 is the same, the image can be displayed brighter than in other methods.

[0058] At least one modulation area is set in the modulation section 2720 of the spatial light modulator 272. The number of modulation areas set in the modulation section 2720 is set according to the number of emitters included in the light source 271. Each of the multiple modulation areas is associated with one of the multiple emitters included in the light source 271. Each of the multiple modulation areas is irradiated with illumination light 201 derived from the laser light emitted from the associated emitter. However, as long as the illumination light 201 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 2720 may be different from the number of emitters included in the light source 271.

[0059] 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 201 is irradiated to the modulation area in a state in which phase images are set to the plurality of tiles, modulated light 202 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 that are set in the modulation area are set according to the application.

[0060] In each of the multiple modulation areas, a pattern (also called a phase image) corresponding to an image displayed by projected light 203 is set according to the control of the communication control device. In each of the multiple modulation areas, a pattern (phase image) is set. Illumination light 201 irradiated to each of the multiple modulation areas is modulated according to the pattern (phase image) set in the modulation area. Modulated light 202 modulated in each of the multiple modulation areas proceeds toward reflecting surface 2730 of light-sending mirror 273.

[0061] For example, a shield (not shown) may be disposed after the spatial light modulator 272. The shield is a frame that shields unnecessary light components contained in the modulated light 202 and defines the outer edge of the display area of ​​the projected light 203. 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 a first-order diffracted light. The shield passes the desired light and shields unnecessary light components. For example, the shield shields ghost images that include the zeroth-order light contained in the modulated light 202, unnecessary first-order light that appears at a position point-symmetrical with respect to the desired light with the zeroth-order light as the center, and second-order or higher-order light. Details of the shield will not be described.

[0062] The light-sending mirror 273 is a reflector having a reflecting surface 2730. The reflecting surface 2730 may be a flat surface or may have a curvature according to the projection angle of the projected light 203. For example, the reflecting surface 2730 may have a shape that combines a curved surface and a flat surface. The light-sending mirror 273 is disposed at the rear of the spatial light modulator 272. The light-sending mirror 273 is disposed at the lower end of a suspension column 274 that is suspended from a top plate 276. The light-sending mirror 273 is disposed so as to be movable within a horizontal plane by a moving mechanism (not shown). In addition, the reflecting surface 2730 of the light-sending mirror 273 is disposed so that the angle can be changed by an angle adjustment mechanism (not shown). The position of the light-sending mirror 273 and the angle of the reflecting surface 2730 are changed according to the control of the communication control device 28. The communication control device 28 changes the position of the light-sending mirror 273 and the angle of the reflecting surface 2730 so that the reflecting surface 2730 faces the arrival direction of the spatial optical signal transmitted from the communication target.

[0063] The light-sending mirror 273 is disposed so that the reflecting surface 2730 faces obliquely with respect to the modulation section 2720 of the spatial light modulator 272. The light-sending mirror 273 is disposed in the optical path of the modulated light 202. The modulated light 202 is irradiated onto the reflecting surface 2730 of the light-sending mirror 273. The light (projected light 203) reflected by the reflecting surface 2730 is projected as a spatial optical signal. The projected light 203 is projected in a direction according to the irradiation position of the modulated light 202 on the reflecting surface 2730 of the light-sending mirror 273. The light (projected light 203) reflected by the reflecting surface 2730 is enlarged and projected at a magnification ratio according to the curvature of the reflecting surface 2730. For example, a lens (not shown) may be disposed after the light-sending mirror 273 in order to adjust the spread of the projected light 203.

[0064] The reflecting surface 2730 of the light-sending mirror 273 is directed in any direction (360 degrees) in a horizontal plane according to the position of the suspension pole 274 that holds the light-sending mirror 273. Therefore, the transmitting device 27 can project the projection light 203 in 360-degree directions in a horizontal plane by controlling the pattern (phase image) set in the modulation section 2720 of the spatial light modulator 272. Also, the transmitting device 27 can transmit the projection light 203 (spatial optical signal) simultaneously toward communication targets arranged in a plurality of directions by associating a plurality of modulation regions set in the modulation section 2720 with different directions. Also, the communication control device 28 controls the projection direction of the projection light 203 in the vertical direction by adjusting the angle of the reflecting surface 2730.

[0065] The transmitting device 27 transmits a spatial optical signal in which at least two transmission patterns are combined according to the transmission direction of the search spatial optical signal. FIG. 21 is a conceptual diagram for explaining the transmission pattern of the search spatial optical signal transmitted from the transmitting device 27. The transmission pattern is set by a combination of a modulation frequency and a signal pattern. In the example of FIG. 21, the spatial optical signal is transmitted in two transmission patterns. The first transmission pattern is a modulation frequency f1 and a signal pattern P1. The second transmission pattern is a modulation frequency f2 and a signal pattern P2. The transmission patterns are not limited to two, and may be set to any number.

[0066] Fig. 22 is a block diagram showing an example of the configuration of the control unit 29 included in the receiving device 20. The control unit 29 has a plurality of detectors 230 and a control circuit 240. Each of the plurality of detectors 230 is associated with each of the plurality of integrating light receiving elements 222. The plurality of detectors 230 are connected to the control circuit 240. The plurality of detectors 230 have the same configuration. Fig. 22 shows the internal configuration of the detector 230 in the uppermost stage. The control unit 29 may be configured in the communication control device 28.

[0067] The detector 230 includes an amplifier 231, a plurality of detection units 232, and an analog-to-digital converter (ADC) 237. The plurality of detection units 232 include a band-pass filter (BPF) corresponding to a frequency band to be received. The BPF cuts off signals derived from ambient light such as sunlight.

[0068] The amplifier 231 is connected to the integrating light receiving element 222. An electrical signal corresponding to the signal light received by the integrating light receiving element 222 is input to the amplifier 231. The amplifier 231 amplifies the input electrical signal by a set amplification factor. The amplification factor of the amplifier 231 can be set arbitrarily. The electrical signal amplified by the amplifier 231 is output to each of the multiple detection units 232.

[0069] The plurality of detection units 232 correspond to the frequency bands to be received. The detector 230 detects modulation frequencies f1, f2, . . . and f n The detection units 232-1 to 232-n (n is a natural number) correspond to the modulation frequencies f1 to f n The modulation frequencies f1 to f2 detected by the detection units 232-1 to 232-n are respectively n Each of these signals is provided to an ADC 237 .

[0070] The detection unit 232-1 includes a BPF (f1_BPF 233-1) that selectively passes a signal of the modulation frequency f1, a detector 234, and an integrator 235. The detection unit 232-2 includes a BPF (not shown) that selectively passes a signal of the modulation frequency f2, a detector 234, and an integrator 235. The detection unit 232-n includes a BPF (not shown) that selectively passes a signal of the modulation frequency f n The detection units 232-1 to 232-n include a BPF (not shown) that selectively passes the signal, a detector 234, and an integrator 235. In the following, of the detection units 232-1 to 232-n, a description of the detection units 232-2 to 232-n will be omitted, and only the detection unit 232-1 will be described.

[0071] The f1_BPF 233-1 is a filter that selectively passes a signal in the frequency band of the modulation frequency f1. The signal that has passed through the f1_BPF 233-1 is supplied to the detector 234.

[0072] The signal of the modulation frequency f1 that has passed through the f1_BPF 233-1 is input to the detector 234. The detector 234 detects the signal of the modulation frequency f1. The signal detected by the detector 234 is supplied to the integrator 235.

[0073] The integrator 235 acquires the signal output from the detector 234. The integrator 235 integrates the acquired signal. The integrator 235 outputs the integrated signal to the ADC 237. Compared to the spatial optical signal for communication (communication light), the spatial optical signal for scanning (scanning light) has a weak intensity due to a large expansion of the beam diameter. Therefore, it is difficult to measure the voltage of the signal amplified only by the amplifier 231. By using the integrator 235, for example, the signal can be integrated over a period of several milliseconds to several tens of milliseconds, thereby increasing the voltage of the signal to a measurable level.

[0074] The ADC 237 receives the modulation frequencies f1 to f2 detected by the detection units 232-1 to 232-n. n The ADC 237 converts the input signals (analog signals) into digital signals. The converted digital signals are output to the control circuit 240.

[0075] The control circuit 240 acquires the digital signals output from each of the multiple detectors 230. The control circuit 240 outputs the acquired digital signals to the communication control device 28. Note that the control of the photoreceiver, which will be described later, may be configured to be executed by the control circuit 240.

[0076] The communication control device 28 acquires the digital signal output from the control circuit 240. The communication control device 28 calculates the reception intensity of the spatial optical signal for each of the integrating light receiving elements 222 for the acquired digital signal. The communication control device 28 changes the position of the light receiving surface of a light receiver (not shown) including the multiple integrating light receiving elements 222 so that the reception intensity for each of the multiple integrating light receiving elements 222 becomes equal. By such control, the focusing position of the signal light focused by the ball lens approaches the center of the multiple integrating light receiving elements 222. The signal light irradiated around the center of the multiple integrating light receiving elements 222 is received by the communication light receiving element (not shown).

[0077] 23 is a conceptual diagram showing an example in which the position of the light receiver 22 is changed according to the intensity of the signal light received by the plurality of integrating light receiving elements 222. In FIG. 23, the light collecting range R of the signal light collected by the ball lens is shown. I The change in the relative position of the photoreceiver 22 with respect to the light is shown in time series. In the following, an example of optimizing the position of the photoreceiver 22 based on the positional relationship on the paper surface will be described. In Fig. 23, numbers (1 to 4) are added to the end of the reference symbols representing the multiple integrating photoreceivers 222 to distinguish them from each other.

[0078] Timing T 11 In this state, if the position of the light receiver 22 is moved to the left, the light collection range R I As a result, the communication control device 28 moves the position of the light receiver 22 to the left so that the light receiving element 225 for communication is irradiated with the signal light.

[0079] Timing T 12 In this state, the signal light is received by the integration light receiving element 222-1, the integration light receiving element 222-4, and the communication light receiving element 225 in accordance with the change in the position of the light receiving element 22. In this state, if the position of the light receiving element 22 is moved diagonally upward to the left, the light collecting range R IThe light receiving element 225 for communication approaches the center of the light receiving element 225. Therefore, the communication control device 28 moves the position of the light receiver 22 diagonally upward and to the left so that the signal light is irradiated onto the light receiving element 225 for communication.

[0080] Timing T 13 In this state, the signal light is received by the integration light receiving element 222-2, the integration light receiving element 222-3, and the communication light receiving element 225 in accordance with the change in the position of the light receiving element 22. In this state, if the position of the light receiving element 22 is moved diagonally downward to the right, the light collecting range R I The light receiving element 225 for communication approaches the center of the light receiving element 225 for communication. Therefore, the communication control device 28 moves the position of the light receiver 22 diagonally downward to the right so that the signal light is irradiated to the light receiving element 225 for communication. At this time, the communication control device 28 12 From timing T 13 In this case, the moving distance of the optical receiver 22 is shortened as compared with the transition to the

[0081] Timing T 14 In this state, the signal light is received by all of the integration light receiving elements 222-1 to 222-4 and the communication light receiving element 225 in response to the change in the position of the light receiver 22. This state is within the light collection range R I In this state, the communication light receiving element 225 can efficiently receive the spatial optical signal transmitted from the communication target.

[0082] Fig. 24 is a conceptual diagram showing an example of changing the transmission direction of the spatial optical signal transmitted from the transmitting device 27. Fig. 24 shows an example in which a calibration is performed in advance to obtain the relationship between the orientation of the light receiving surface of the optical receiver 22 and the transmission direction of the spatial optical signal, and the transmission direction of the spatial optical signal is optimized in accordance with the movement of the optical receiver 22. The time series changes shown in Fig. 24 correspond to the time series changes shown in Fig. 23. The communication control device 28 adjusts the light collection range R in accordance with the intensity of the signal light received by each of the multiple integrating light receiving elements 222-1 to 4. IThe communication control device 28 changes the transmission direction of the spatial optical signal transmitted from the transmitting device 27 in accordance with the movement of the communication light receiving element 225. In this way, the light collection range R I If the transmission direction of the spatial optical signal is changed in accordance with the movement of the communication light receiving element 225 toward the center of the communication object T, the transmission direction of the spatial optical signal can be more accurately adjusted toward the communication object T. T The spatial light signal is irradiated at the position P S 4 shows a time series of changes in the relative positions of the two elements. In the following, an example of optimizing the transmission direction of the spatial optical signal based on the positional relationship on the paper surface will be described.

[0083] Timing T 21 is the timing T 11 The timing precedes the irradiation position P S is on the left side of the communication target T. 11 In response to the reception state of the signal light at , the communication control device 28 shifts the transmission direction of the spatial optical signal to the right so that the spatial optical signal is received by the communication target T.

[0084] Timing T 22 is the timing T 11 The timing follows the irradiation position P S is diagonally above and to the left of the communication target T. 12 In accordance with the reception state of the signal light at , the communication control device 28 shifts the transmission direction of the spatial optical signal diagonally downward to the right so that the spatial optical signal is received by the communication object T.

[0085] Timing T 23 is the timing T 12 The timing follows the irradiation position P S is slightly below the communication target T. 13In response to the reception state of the signal light at the communication control device 28, the communication control device 28 shifts the transmission direction of the spatial optical signal slightly upward so that the spatial optical signal is received by the communication object T.

[0086] Timing T 24 is the timing T 13 This state is the timing following the irradiation position P S almost coincides with the communication target T. In this state, the spatial optical signal transmitted from the transmitting device 27 is efficiently received by the communication target.

[0087] FIG. 25 is a conceptual diagram for explaining an example of transmission of a spatial light signal for scanning (scanning light). The transmitting device 27 controls the transmission direction of the scanning light by controlling the phase image set in the modulation unit 2720 of the spatial light modulator 272. The transmitting device 27 divides the search range of the communication target into several sub-areas and transmits the scanning light. In the example of FIG. 25, the search range is divided into nine sub-areas, and the scanning light is transmitted for each sub-area. For a single sub-area, the transmitting device 27 transmits the scanning light while changing the transmission direction in a spiral shape from the center of the sub-area. Note that transmitting the scanning light in a spiral shape is an example, and does not limit the method of transmitting the scanning light. When the boundary of the sub-area is reached, the transmitting device 27 transmits the scanning light for the other sub-areas in the same manner. For example, the transmitting device 27 transmits the scanning light for a plurality of sub-areas included in the search range in the order of center, left, right, top, bottom, top left, top right, bottom left, and bottom right. In the stage of transmitting the scanning light, the scanning light is transmitted toward the direction in which the communication target is assumed to be located. Therefore, there is a high probability that the communication target is located near the center of the search area. Therefore, the transmission direction of the scanning light is switched from the central sub-area to the surrounding sub-areas in sequence. Note that the order of the sub-areas to which the scanning light is transmitted may be set arbitrarily.

[0088] FIG. 26 is a diagram for explaining an example of a transmission pattern of a spatial optical signal transmitted from the transmitting device 27. FIG. 26 shows a search range of a scanning light transmitted from the transmitting device 27. In FIG. 26, the search range is divided into nine sub-areas. Each of the nine sub-areas is further divided into four small areas. That is, the search range is divided into 36 small areas. The small areas are expressed by a combination of a row symbol and a column symbol. For example, a small area at row R1, column C1 is expressed as small area R1C1.

[0089] A transmission pattern in which a unique modulation frequency and a signal pattern are combined is set for each of the multiple small regions. A modulation frequency f2 is set for rows R1 and R2. A modulation frequency f1 is set for rows R3 and R4. A modulation frequency f3 is set for rows R5 and R6. For example, a spatial optical signal having a transmission pattern in which a modulation frequency f2 and a signal pattern P6 are combined is transmitted to the small region R1C1. The transmission pattern of the spatial optical signal transmitted to the multiple small regions is set to a unique pattern for each small region. A communication target located within the search range receives a spatial optical signal having a transmission pattern associated with the small region. In FIG. 26, it is assumed that the communication target is located at the position of the small region R2C3.

[0090] Fig. 27 is a conceptual diagram for explaining an example of establishing communication between a communication device 2A and a communication device 2B. Fig. 27 shows, in a time series, a change in the transmission direction of a spatial optical signal according to a change in time.

[0091] At timing T1, the communication device 2A transmits a modulation frequency f m A signal pattern p modulated by n At timing T1, the communication device 2A transmits a spatial optical signal of signal pattern p3 modulated with modulation frequency f2. At timing T1, the communication device 2A receives the spatial optical signal transmitted from the communication device 2B. The communication device 2A receives the spatial optical signal of signal pattern p3 modulated with modulation frequency f2.

[0092] At timing T2, the communication device 2A transmits a modulation frequency f m A signal pattern p modulated by n+1 and a signal pattern p3 modulated at the modulation frequency f2. The communication device 2B transmits a spatial optical signal of a signal pattern p4 modulated at the modulation frequency f2.

[0093] At timing T3, the communication device 2A transmits the modulation frequency f m A signal pattern p modulated by n+2 The communication device 2B transmits a spatial optical signal in which a signal pattern p modulated at a modulation frequency f2 is combined with a signal pattern p 11 At a timing T3, the communication device 2B receives the spatial optical signal transmitted from the communication device 2A. The communication device 2B receives the spatial optical signal having a modulation frequency f m A signal pattern p modulated by n+2 At this point, the communication device 2B determines that the spatial optical signal transmitted toward the small region R2C3 has been received by the communication device 2B. The communication device 2B receives a spatial optical signal in which the signal pattern p3 modulated with the modulation frequency f2 and the signal pattern p4 modulated with the modulation frequency f1 are combined toward the identified small region R2C3. m A signal pattern p modulated by n+2 The spatial light signal is a combination of the signal pattern p3 modulated with the modulation frequency f2 and the signal pattern p4 modulated with the modulation frequency f m A signal pattern p modulated by n+2 When the communication device 2A receives the spatial optical signal in which the above-mentioned signals are combined, the communication device 2A and the communication device 2B share a mutual positional relationship.

[0094] FIG. 28 is a conceptual diagram for explaining a process of optimizing the transmission direction of a spatial optical signal transmitted from the communication device 2B toward the communication device 2A. In the example of FIG. 26 to FIG. 27, when the communication device 2B determines that the communication device 2A is located in the direction of the small region R2C3, the communication device 2B divides the small region R2C3 into further small regions. In the example of FIG. 28, the small region R2C3 is divided into four small regions. The communication device 2B transmits a spatial optical signal with a reduced beam diameter to each of the four small regions with a different signal pattern. At the stage of FIG. 28, since the position of the communication device 2A in the column direction is determined, the communication device 2B does not need to change the modulation frequency of the spatial optical signal. For example, the communication device 2B transmits a spatial optical signal modulated with a modulation frequency f4. In the example of FIG. 28, the communication device 2A is located in the direction of the small region R22C31.

[0095] When the communication device 2B determines that the communication device 2A is located in the direction of the small region R22C31, it divides the small region R22C31 into further small regions. In the example of FIG. 28, the small region R22C31 is divided into four small regions. The communication device 2B transmits a spatial optical signal with a further reduced beam diameter to each of the four small regions with a different signal pattern. For example, the communication device 2B transmits a spatial optical signal modulated at a modulation frequency f4. In the example of FIG. 28, the communication device 2A is located in the direction of the small region R221C311. In this way, by repeatedly dividing the small regions, the direction of the communication target can be more accurately determined.

[0096] FIG. 29 is a conceptual diagram for explaining how the communication device 2B uses communication light to accurately identify its position after the position of the communication device 2A is identified by the scanning light. In the example of FIG. 29, the hatched beam is received by the communication device 2A. At the stage of FIG. 29, the communication device 2A can be scanned using communication light with a small beam diameter. More information can be transmitted and received by using the communication light. Therefore, the communication device 2B can accurately identify the position of the communication device 2A using the communication light.

[0097] (operation) Next, an example of the operation of the communication device 2 will be described with reference to the drawings. In the following, an example of control of the receiving device 20 and the transmitting device 27 by the communication control device 28 will be illustrated. In the following description, the communication control device 28 is the subject of the operation.

[0098] [Receiving device] FIG. 30 is a flowchart for explaining an example of control of the receiving device 20 by the communication control device 28.

[0099] 30, when a scanning light is received from a communication target (Yes in step S211), the communication control device 28 changes the position of the light receiver according to the receiving position of the scanning light from the communication target (step S212). When a scanning light is not received from a communication target (No in step S211), the communication control device 28 waits for reception of the scanning light.

[0100] After step S212, the communication control device 28 transmits to the transmitting device an instruction to change the transmission conditions of the scanning light according to the receiving position of the scanning light from the communication target (step S213).

[0101] If the position adjustment of the light receiver using the scanning light is not completed (No in step S214), the process returns to step S211. If the position adjustment of the light receiver using the scanning light is completed (Yes in step S214), the communication control device 28 transmits an instruction to transmit the communication light to the transmission device (step S215).

[0102] Next, the communication control device 28 performs position adjustment using the communication light (step S216).

[0103] If the position adjustment of the optical receiver using the communication light is not completed (No in step S217), the process returns to step S215. If the position adjustment of the optical receiver using the communication light is completed (Yes in step S217), the process according to the flowchart in FIG. 30 ends.

[0104] [Transmitting device] FIG. 31 is a flowchart for explaining an example of control of the transmission device 27 by the communication control device .

[0105] In FIG. 31, first, the communication control device 28 sets a modulation frequency and a signal pattern according to the transmission direction (step S221).

[0106] Next, the communication control device 28 transmits a scanning light having the set modulation frequency and signal pattern (step S222).

[0107] When the instruction to change the transmission conditions of the scanning light is received (Yes in step S223), the communication control device 28 changes the transmission conditions of the scanning light in response to the instruction to change (step S224). After step S224, the process returns to step S221.

[0108] If an instruction to change the transmission conditions of the scanning light has not been received (No in step S223), the communication control device 28 executes a process (step S225) according to whether or not a signal instructing transmission of communication light has been received. If an instruction to transmit communication light has not been received (No in step S225), the process returns to step S221.

[0109] If an instruction to transmit communication light has been received (Yes in step S225), the communication control device 28 causes the transmitting device 27 to transmit communication light (step S226).

[0110] If the position adjustment of the optical receiver using the communication light is not completed (No in step S227), the communication control device 28 causes the transmitter 27 to continue transmitting the communication light (step S226). If the position adjustment of the optical receiver using the communication light is completed (Yes in step S227), the process according to the flowchart in Fig. 31 ends.

[0111] 30 to 31, communication is established between the communication device 2 and the communication target. Description of the communication between the communication device 2 and the communication target will be omitted.

[0112] As described above, the communication device of this embodiment includes a receiving device, a transmitting device, and a communication control device. The receiving device has the configuration of the first embodiment. The transmitting device transmits a spatial optical signal. The communication control device controls the position and angle of the optical receiver and the transmission direction of the spatial optical signal transmitted from the transmitting device according to the light receiving position of the spatial optical signal by the optical receiver of the receiving device. According to this aspect, a communication angle of 360 degrees can be realized by controlling the position and angle of the optical receiver of the receiving device and the transmission direction of the spatial optical signal transmitted from the transmitting device according to the light receiving position of the spatial optical signal.

[0113] In one aspect of this aspect, the communication control device causes the transmitting device to transmit a search spatial optical signal having a transmission pattern in which a modulation frequency and a signal pattern that differ according to the transmission direction of the spatial optical signal are combined, in association with the transmission direction. In response to reception by the receiving device of the search spatial optical signal transmitted from the communication target, the communication control device causes the transmitting device to transmit a spatial optical signal to which the transmission pattern of the received search spatial optical signal has been added, in association with the transmission direction. The communication device of this aspect obtains the transmission pattern of the search spatial optical signal transmitted from the communication target. The communication device of this aspect returns the transmission pattern of the received search spatial optical signal to the communication target, so that the communication target can specify in which direction the spatial optical signal transmitted by the communication device was received. If the communication target transmits the spatial optical signal in the specified direction, a process of establishing communication can be performed between the communication device and the communication target.

[0114] In one aspect of this aspect, the communication control device changes the position of the optical receiver in the receiving device in response to reception by the receiving device of a search spatial optical signal transmitted from a communication target. The communication control device changes the position of the optical receiver in the receiving device in response to the intensity of signal light based on the search spatial optical signal received by each of a plurality of integrating light receiving elements included in the receiving device. The communication control device transmits an instruction to the transmitting device to change the transmission conditions of the search spatial optical signal. According to this aspect, the position of the optical receiver and the transmission direction of the search spatial optical signal can be adjusted in response to the intensity of the signal light received by each of the plurality of integrating light receiving elements.

[0115] In one aspect of this aspect, the communication control device executes a detailed scan using the communication light receiving element in response to completion of position adjustment of the light receiving device using the integrating light receiving element. When the mutual directions between the communication control device and the communication target are specified, the communication control device causes the transmitting device to transmit a search spatial optical signal with a narrowed search range and beam diameter. According to this aspect, the position of the communication target can be accurately specified by narrowing the search range and beam diameter of the search spatial optical signal transmitted and received between the communication target. Furthermore, according to this aspect, the light receiving efficiency of the communication light receiving element can be optimized by executing a detailed scan using the communication light receiving element.

[0116] Third embodiment Next, a receiving device according to a third embodiment will be described with reference to the drawings. The receiving device of this embodiment has a simplified configuration of the receiving devices of the first and second embodiments.

[0117] Fig. 32 is a conceptual diagram showing an example of the configuration of the receiving device 30 in the present disclosure. Fig. 32 is a conceptual diagram looking down on the receiving device 30 from a viewpoint diagonally above. Figs. 33 and 34 are side views showing an example of the configuration of the optical receiver 32 provided in the receiving device 30. Fig. 33 is a side view of the optical receiver 32 as viewed from a lateral viewpoint. Fig. 34 is a perspective view of the light receiving surface of the optical receiver 32 as viewed diagonally from above.

[0118] The receiving device 30 includes a ball lens 31, at least one light receiver 32, and a support 38. The light receiver 32 includes a substrate 321, a plurality of integral light receiving elements 322, a light guide tube 324, and a communication light receiving element 325. The substrate 321 has a first surface facing the ball lens 31 and a second surface facing the first surface. A through hole A is formed in the substrate 321, penetrating the first surface and the second surface. The plurality of integral light receiving elements 322 are arranged around the through hole A on the first surface of the substrate 321, with the light receiving portion 323 facing the ball lens 31. The light guide tube 324 includes a first opening end corresponding to the through hole A and a second opening end facing the first opening end. The light guide tube 324 is arranged on the second surface side of the substrate 321 in accordance with the through hole A. Light-receiving element for communication 325 is disposed at the second open end of light guide tube 324, with light-receiving portion 326 facing ball lens 31. Support 38 movably supports the light receiver around ball lens 31. In the example of Fig. 32, light-receiver 32 is disposed at the upper end of support 38. In addition, the lower end of support 38 is disposed movably along a circular orbit R having an annular shape.

[0119] According to the receiving device of this embodiment, the light receiving surface of the light receiver can be oriented in a 360-degree direction by moving the light receiver around the ball lens. That is, according to this embodiment, a communication angle of 360 degrees can be realized.

[0120] (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. 35 is given as an example of such a hardware configuration. The information processing device 90 in Fig. 35 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.

[0121] As shown in Fig. 35, 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. 35, 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.

[0122] 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.

[0123] 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.

[0124] 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.

[0125] 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.

[0126] 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.

[0127] 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.

[0128] 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.

[0129] The above is an example of a hardware configuration for enabling the control and processing in the present disclosure. The hardware configuration in FIG. 35 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 that causes a computer to execute the control and processing in the present disclosure is also included in the scope of the present disclosure.

[0130] A program recording medium on which the program in the present disclosure is recorded is also included in the scope of the present disclosure. The recording medium can be realized by, for example, 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. When the program executed by the processor is recorded on a recording medium, the recording medium corresponds to a program recording medium.

[0131] 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.

[0132] Although the present invention has been described above with reference to the embodiments, the present invention is not limited to the above-mentioned embodiments. Various modifications that can be understood by those skilled in the art can be made to the configuration and details of the present invention within the scope of the present invention. [Explanation of symbols]

[0133] 2. Communications equipment 10, 20, 30 Receiving device 11, 31 Ball Lens 12, 32 receiver 18, 38 posts 19, 29 Control section 27 Transmitting Device 28 Communication Control Device 121, 321 board 122, 128, 222, 322 Integral light receiving element 124, 324 Light guide tube 125, 325 Communication photodetector 127 Filters 180 Foundation 230 Detector 231 Amplifier 233 BPF 234 Detector 235 Integrator 237 ADC 240 Control circuit 271 Light source 272 Spatial Light Modulator 273 Light-transmitting mirror 274 Hanging Pillar 276 Tabletop 277 Bottom plate

Claims

1. A ball lens and At least one optical receiver; a support column that movably supports the light receiver around the ball lens; Equipped with The optical receiver includes: a substrate having a first surface facing the ball lens and a second surface opposite to the first surface, the substrate having a through hole penetrating the first surface and the second surface; a plurality of integral light receiving elements arranged around the through hole on the first surface of the substrate with light receiving portions facing the ball lens; a light guiding tube including a first opening end corresponding to the through hole and a second opening end opposite to the first opening end, the light guiding tube being arranged on the second surface side of the substrate in alignment with the through hole; a communication light-receiving element arranged at the second opening end of the light-guiding tube with a light-receiving portion facing the ball lens.

2. The plurality of integral light receiving elements are arranged in a point-symmetrical positional relationship with respect to the center of the through hole, 2. The receiving device according to claim 1, wherein the light receiving portion of the communication light receiving element is arranged to coincide with a light collecting point of the ball lens.

3. a control unit that receives an electrical signal based on the signal light received by the plurality of integration light-receiving elements and the communication light-receiving element, and adjusts an angle of the light-receiving surface of the light-receiving element and a position of the support in response to the received electrical signal; The control unit is 3. The receiving device according to claim 2, wherein an angle of the light receiving surface of the light receiver and a position of the support are adjusted according to the intensity of the signal light received by each of the plurality of integrating light receiving elements, and a position of the light receiving part of the communication light receiving element is adjusted to match the focusing position of the signal light focused by the ball lens.

4. The control unit is 4. The receiving device according to claim 3, wherein the angle of the light receiving surface of the light receiver and the position of the support are moved toward the integrating light receiving element having the greatest receiving intensity depending on the intensity of the signal light received by each of the plurality of integrating light receiving elements.

5. 2. The receiving device according to claim 1, further comprising filters arranged in association with the light receiving sections of the plurality of integration light receiving elements and the communication light receiving element, for selectively passing light in a wavelength band of the spatial optical signal to be received.

6. 2. The receiving device according to claim 1, wherein the integration light receiving element and the communication light receiving element are light receiving elements sensitive to light in different wavelength bands.

7. A receiving device according to any one of claims 1 to 6, A transmitting device for transmitting a spatial light signal; A communication device comprising: a communication control device that controls a position and angle of a light receiver of the receiving device and a transmission direction of a spatial optical signal transmitted from the transmitting device according to a receiving position of the spatial optical signal by the light receiver of the receiving device.

8. The communication control device includes: transmitting a search spatial optical signal having a transmission pattern in which a modulation frequency and a signal pattern that differ according to a transmission direction of the spatial optical signal are combined with the transmission pattern of the search spatial optical signal in association with the transmission direction; 8. The communication device according to claim 7, wherein, in response to reception by the receiving device of a search spatial optical signal transmitted from a communication target, the transmitting device transmits a spatial optical signal to which a transmission pattern of the received search spatial optical signal has been added in association with a transmission direction.

9. The communication control device includes: In response to receiving the search spatial light signal transmitted from the communication target by the receiving device, changing a position of the light receiver in the receiving device according to an intensity of a signal light based on a search spatial light signal received by each of a plurality of integrating light receiving elements included in the receiving device; 9. The communication device according to claim 8, further comprising: a command to change a transmission condition of the search spatial optical signal to the transmitting device.

10. The communication control device includes: When the directions between the communication target and the communication target are specified, a search spatial light signal having a narrowed search range and a narrowed beam diameter is transmitted to the transmission device; The communication device according to claim 9 , wherein a detailed scan is performed using the communication light receiving element in response to completion of position adjustment of the light receiving device using the integrating light receiving element.

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