JP7320018B2 - Photodetector and communication system - Google Patents

Description

Application of Patent Law Article 30, Paragraph 2 activity/kenkyuu-happyoukai/happyou-ronbun/26/pdf/42.pdf) published research on "light receiving devices and communication systems" (acquisition and tracking of ground stations by mobile objects using retroreflected light). On March 6, 2021, at the 26th Research Presentation Meeting of the Tokyo Branch of the Institute of Electronics, Information and Communication Engineers (IEICE), research on "light receiving devices and communication systems" (acquisition and tracking of ground stations by mobile objects using retroreflected light ) was published.

The present invention relates to a photodetector and a communication system.

Patent Literature 1 describes that optical communication is performed between HAPS (High Altitude Platform System) and ground feeder stations.
[Prior art documents]
[Patent Literature]
[Patent Document 1] JP 2021-034922 A

According to one embodiment of the present invention, a light receiving device is provided. The light receiving device may include a lens barrel. The light-receiving device may include a primary mirror that is arranged inside the lens barrel and reflects light incident from the outside. The light-receiving device may include a secondary mirror arranged in the lens barrel and reflecting light reflected by the primary mirror. The light-receiving device may include a light-receiving section that receives light reflected by the secondary mirror. The light-receiving device may include a reflecting surface that is arranged on the side of the secondary mirror opposite to the side on which the light from the primary mirror is incident and that reflects externally incident light to the outside.

The light-receiving device may include a reflecting mirror having the reflecting surface, which is disposed on the side of the secondary mirror opposite to the side on which the light from the primary mirror is incident. The reflecting mirror may be a retroreflecting mirror that reflects the incident light from the outside in the incident direction. The size of the reflecting mirror in a direction intersecting the direction in which light is incident on the barrel portion is equal to or smaller than the size of the secondary mirror in the direction intersecting the direction in which light is incident on the barrel portion. good. The reflecting mirror may be fixed by magnetic force to the side of the secondary mirror opposite to the side on which the light from the primary mirror is incident. The reflecting mirror may be fixed by screwing to the side of the secondary mirror opposite to the side on which the light from the primary mirror is incident. The secondary mirror may have both a surface that reflects light reflected by the primary mirror and a reflecting surface that is located on the side opposite to the side on which the light from the primary mirror is incident.

The light receiving unit may have an optical antenna that realizes optical communication using received light. The light receiving unit may have an optical sensor array and a beam splitter that splits the light reflected by the secondary mirror toward the optical antenna and the optical sensor array. The light receiving device may include an axis control section that adjusts the axis of the lens barrel so that the light incident on the optical sensor array is positioned at the center of the optical sensor array. The light-receiving device may include a position information acquisition section that acquires position information indicating the position of the transmitter transmitted by the transmitter, and the axis control section controls the light output from the transmitter based on the position information. After adjusting the axis of the barrel to be incident on the barrel, the axis of the barrel may be adjusted so that the light incident on the photosensor array is centered on the photosensor array. The location information acquisition unit may acquire the location information from ADS-B information including the location information transmitted by the transmitter. The transmitter may be mounted on an air vehicle that provides wireless communication services to user terminals within a wireless communication area formed by flying in the stratosphere and irradiating a beam toward the ground.

According to one embodiment of the present invention, a light receiving device is provided. The receiver may comprise an optical antenna. The receiving device may comprise a photosensor array. The receiver may comprise a beam splitter for splitting the light output by the transmitter, incident on and output from the telescope towards the optical antenna and the optical sensor array. The light receiving device may comprise an axis control for adjusting the axis of the telescope so that the light incident on the photosensor array is centered on the photosensor array. The light receiving device may include an optical communication unit that performs optical communication using an optical antenna.

The light-receiving device may include a position information acquisition section that acquires position information indicating the position of the transmitter transmitted by the transmitter, and the axis control section controls the position of the transmitter based on the position information. After adjusting the axis of the telescope so that the output light is incident on the telescope, adjusting the axis of the telescope so that the light incident on the photosensor array is positioned at the center of the photosensor array. can be adjusted. The location information acquisition unit may acquire the location information from ADS-B information including the location information transmitted by the transmitter. The transmitter may be mounted on an air vehicle that provides wireless communication services to user terminals within a wireless communication area formed by flying in the stratosphere and irradiating a beam toward the ground.

According to one embodiment of the present invention, there is provided a communication system comprising the photodetector and the transmitter.

It should be noted that the above summary of the invention does not list all the necessary features of the invention. Subcombinations of these feature groups can also be inventions.

An example of a communication system 10 is shown schematically. An example of the configuration of ground station 200 is shown schematically. An example of the configuration of ground station 200 is shown schematically. An example of the configuration of ground station 200 is shown schematically. An example of the configuration of ground station 200 is shown schematically. An example of the configuration of a light receiving unit 400 and a control unit 500 is schematically shown. An example of an image 600 captured by the photosensor array 420 is schematically shown. An example of the flow of processing in the communication system 10 is shown schematically. 1 schematically shows an example of the configuration of a communication device 130 mounted on an aircraft 100. FIG. An example of a hardware configuration of a computer 1200 functioning as a control unit 500 or a communication device 130 is shown schematically.

For example, in the case of optical communication between a communication device on the ground and a communication device in the sky, a structure that emits a laser beam from the ground may affect the surroundings. Instead, it is conceivable to align the optical axes using reflected light. In this case, for example, a telescope or the like having a reflecting mirror is installed in the communication device on the ground. With such a configuration, the position of the reflecting mirror is displaced from the position of the telescope, and the laser light used for communication differs from the original optical axis of the telescope, so it is necessary to adjust the optical axis. As the optical axis is adjusted, the reflected light is weakened and communication efficiency is reduced. The communication system 10 according to this embodiment includes a light receiving device that does not require such adjustment of the optical axis.

Hereinafter, the present invention will be described through embodiments of the invention, but the following embodiments do not limit the invention according to the claims. Also, not all combinations of features described in the embodiments are essential for the solution of the invention.

FIG. 1 schematically illustrates an example communication system 10 . Communication system 10 includes an air vehicle 100 and a ground station 200 .

Aircraft 100 may be an example of a transmitter. Examples of the flying object 100 include HAPS, unmanned aerial vehicles such as drones, and aircraft.

Ground station 200 may be an example of a light receiving device. The air vehicle 100 and the ground station 200 perform optical communication. The flying object 100 and the ground station 200 according to the present embodiment have, for example, a configuration for performing optical axis alignment in spatial optical communication with high accuracy.

For example, the flying object 100 irradiates the light 12 toward the ground station 200 and observes the reflected light 22 from the ground station 200 using pre-registered position information of the ground station 200 . The flying object 100 adjusts the irradiation direction of the light 12 so that the reflected light 22 is maximized. After adjustment, the aircraft 100 establishes communication with the ground station 200 and performs optical communication with the ground station 200 .

Ground station 200 may include a telescope for receiving light 12 from air vehicle 100 . In the prior art, the light 12 was reflected by arranging a reflector beside the telescope. Since it is different from the optical axis, it is necessary to adjust the optical axis. In the prior art, such adjustment of the optical axis weakens the reflected light and reduces the communication efficiency. In contrast, the ground station 200 according to this embodiment has a configuration that reduces such positional deviation.

The ground station 200 comprises a telescope with a so-called secondary mirror. Examples of telescopes having secondary mirrors include Cassegrain and Newtonian reflectors, as well as Dole-Kercam, Epsilon, and Gregory telescopes. The ground station 200 has a reflecting surface on the secondary mirror that reflects externally incident light to the outside. The ground station 200 includes, for example, a retroreflection mirror on the secondary mirror that reflects externally incident light to the outside. The retroreflective mirror may be a so-called CCR (Corner Cube Reflector). Because the secondary mirror is centered in the telescope aperture, placing the retroreflector on top of the secondary mirror reduces misalignment compared to placing the reflector on the side of the telescope. can do. Also, by making the size of the retroreflector equal to or smaller than the size of the secondary mirror, it is possible not to block the effective area of the aperture of the telescope. By making the size of the retroreflector smaller than the size of the secondary mirror, the size of the retroreflector is reduced, and it may be difficult to apply it to spatial optical communication with artificial satellites at a distance of at least 700 km. The distance between HAPS, drones, aircraft and the ground is often 20 km or less, which is sufficiently applicable.

FIG. 2 schematically shows an example of the configuration of ground station 200. As shown in FIG. The ground station 200 includes a telescope section 300 , a light receiving section 400 and a control section 500 . FIG. 2 exemplifies the case where the type of the telescope unit 300 is the Cassegrain type.

The telescope section 300 includes a lens barrel section 310 , a primary mirror 320 , a secondary mirror 330 and a retroreflection mirror 340 . The primary mirror 320 is arranged inside the lens barrel section 310 and reflects light incident from the outside. The secondary mirror 330 is arranged inside the barrel section 310 and reflects the light reflected by the primary mirror 320 .

The light receiving section 400 receives light reflected by the secondary mirror 330 . The control unit 500 realizes optical communication using light received by the light receiving unit 400 and adjusts the axis of the telescope unit 300 .

The retroreflection mirror 340 is arranged on the side of the secondary mirror 330 opposite to the side on which the light from the primary mirror 320 is incident. The retroreflecting mirror 340 has a reflecting surface that reflects externally incident light to the outside. This can reduce the deviation between the optical axis of light incident from the outside and the optical axis of reflected light, compared to the case where the reflecting mirror is arranged beside the telescope section 300 .

The size of the retroreflector 340 may be less than or equal to the size of the secondary mirror 330 . The size of the retroreflection mirror 340 in the direction crossing the direction of light incidence on the lens barrel 310 is equal to or smaller than the size of the secondary mirror 330 in the direction crossing the direction of light incidence on the lens barrel 310. can be Thereby, the effective area of the opening of the telescope part 300 can be prevented from being obstructed.

The retroreflection mirror 340 is, for example, fixed by magnetic force to the side of the secondary mirror 330 opposite to the side on which the light from the primary mirror 320 is incident. Further, the retroreflection mirror 340 is fixed by screwing, for example, to the side of the secondary mirror 330 opposite to the side on which the light from the primary mirror 320 is incident. Further, the retroreflection mirror 340 may be integrated with the secondary mirror 330, for example. As a result, a holding arm or the like for holding the retroreflecting mirror 340 can be omitted, and the holding arm can be prevented from obstructing the effective opening area of the telescope section 300 . Also, the configuration of the telescope section 300 can be simplified.

Note that FIG. 2 illustrates the case where the telescope unit 300 includes the retroreflection mirror 340, but the present invention is not limited to this. Telescope section 300 may include a non-retroreflector instead of retroreflector 340 .

FIG. 3 schematically shows an example of the configuration of ground station 200. As shown in FIG. Here, points different from FIG. 2 will be mainly described. The secondary mirror 330 of the telescope unit 300 shown in FIG. 3 has a reflecting surface 332 that reflects the light reflected by the primary mirror 320, and a reflecting surface 334 that is arranged on the side opposite to the side on which the light from the primary mirror 320 is incident. have both The reflecting surface 334 reflects externally incident light to the outside. As a result, as compared with the case where the reflecting mirror is arranged near the telescope section 300, it is possible to reduce the deviation between the direction of incidence and the direction of reflection of light incident from the outside.

FIG. 4 schematically shows an example of the configuration of ground station 200. As shown in FIG. The ground station 200 shown in FIG. 4 differs from the ground station 200 shown in FIG. 2 in the structure of the telescope section 300 . FIG. 3 exemplifies a case where the type of the telescope unit 300 is a Newtonian reflection type.

The telescope section 300 includes a lens barrel section 350 , a primary mirror 360 , a secondary mirror 370 and a retroreflection mirror 380 . The primary mirror 360 is arranged inside the barrel section 350 and reflects light incident from the outside. The secondary mirror 370 is arranged inside the barrel section 350 and reflects the light reflected by the primary mirror 360 .

The light receiving section 400 receives light reflected by the secondary mirror 370 . The control unit 500 realizes optical communication using light received by the light receiving unit 400 and adjusts the axis of the telescope unit 300 .

The retroreflection mirror 380 is arranged on the side of the secondary mirror 370 opposite to the side on which the light from the primary mirror 360 is incident. The retroreflecting mirror 380 has a reflecting surface that reflects externally incident light to the outside. As a result, as compared with the case where the reflecting mirror is arranged near the telescope section 300, it is possible to reduce the deviation between the direction of incidence and the direction of reflection of light incident from the outside.

The size of retroreflector 380 may be less than or equal to the size of secondary mirror 370 . The size of the retroreflecting mirror 380 in the direction intersecting the direction of light incidence on the lens barrel portion 350 is equal to or smaller than the size of the secondary mirror 370 in the direction intersecting the direction of light incidence on the lens barrel portion 350. can be Thereby, the effective area of the opening of the telescope part 300 can be prevented from being obstructed.

The retroreflection mirror 380 is, for example, fixed by magnetic force to the side of the secondary mirror 370 opposite to the side on which the light from the primary mirror 360 is incident. Further, the retroreflection mirror 380 is fixed by screwing, for example, to the side of the secondary mirror 370 opposite to the side on which the light from the primary mirror 360 is incident. Also, the retroreflector 380 may be integrated with the secondary mirror 370, for example. As a result, a holding arm or the like for holding the retroreflection mirror 380 can be omitted, and the holding arm can be prevented from obstructing the effective opening area of the telescope section 300 . Also, the configuration of the telescope section 300 can be simplified.

Although FIG. 4 exemplifies the case where the telescope unit 300 includes the retroreflection mirror 380, the present invention is not limited to this. Telescope section 300 may include a non-retroreflector instead of retroreflector 380 .

FIG. 5 schematically shows an example of the configuration of ground station 200. As shown in FIG. Here, points different from FIG. 4 will be mainly described. The secondary mirror 370 of the telescope unit 300 shown in FIG. 5 has a reflecting surface 372 that reflects the light reflected by the primary mirror 360, and a reflecting surface 374 that is arranged on the side opposite to the side on which the light from the primary mirror 360 is incident. have both The reflecting surface 374 reflects externally incident light to the outside. As a result, as compared with the case where the reflecting mirror is arranged near the telescope section 300, it is possible to reduce the deviation between the direction of incidence and the direction of reflection of light incident from the outside.

FIG. 6 schematically shows an example of the configuration of the light receiving section 400 and the control section 500. As shown in FIG. The light receiving section 400 includes an optical antenna 410 , an optical sensor array 420 , a half mirror 430 and a lens 440 . The control unit 500 includes a communication unit 510 , a position information acquisition unit 520 and an axis control unit 530 .

The optical antenna 410 realizes optical communication using received light. Photosensor array 420 is composed of a plurality of photosensors. The photosensor array 420 may be, for example, a CCD (Charge-Coupled Device).

The half mirror 430 splits the light reflected by the secondary mirror 330 or the secondary mirror 370 of the telescope section 300 and incident on the light receiving section 400 toward the optical antenna 410 and the optical sensor array 420 . Half mirror 430 may be an example of a beam splitter. Light directed from half mirror 430 to optical antenna 410 reaches optical antenna 410 via lens 440 .

The communication unit 510 may perform various communications. The communication unit 510 performs optical communication using the optical antenna 410, for example. The communication unit 510 may include, for example, an optical communication modem, and uses the optical communication modem to convert the light received by the optical antenna 410 into a digital signal.

The communication unit 510 may perform communication via terrestrial networks such as the Internet, mobile communication networks, and LANs (Local Area Networks). Communications unit 510 may communicate with a communications satellite. The communication unit 510 communicates with a communication satellite, for example, via a satellite gateway located on the ground.

The position information acquisition unit 520 acquires position information indicating the position of the aircraft 100 . The position information acquisition unit 520 may acquire the position information of the flying object 100 transmitted by the flying object 100, for example. The position information acquisition unit 520 acquires the position information of the flying object 100 from, for example, ADS-B (Automatic Dependent Surveillance-Broadcast) information including the position information of the flying object 100 transmitted by the flying object 100 .

The position information acquisition unit 520 receives, for example, the position information of the flying object 100 transmitted by the flying object 100 via a network on the ground. The position information acquisition unit 520 receives, for example, the position information of the flying object 100 transmitted by the flying object 100 via a communication satellite.

The position information acquisition unit 520 receives, for example, ADS-B information transmitted by the aircraft 100 via a ground network. The position information acquisition unit 520 receives, for example, ADS-B information transmitted by the aircraft 100 via a communication satellite.

The air vehicle 100 may have a function of communicating with a communication satellite, and transmits position information or ADS-B information of the air vehicle 100 to the communication satellite. In addition, the flying object 100 may transmit position information or ADS-B information of the flying object 100 to a management device that manages the flying object 100 placed on the ground.

The axis control section 530 controls the axis of the lens barrel section 310 . Axis control section 530 may adjust the axis of lens barrel section 310 so that the light incident on optical sensor array 420 is positioned at the center of optical sensor array 420 . For example, the axis control unit 530 adjusts the axis of the lens barrel unit 310 based on the position information acquired by the position information acquisition unit 520 so that the light output by the flying object 100 is incident on the lens barrel unit 310. , the axis of the lens barrel 310 is adjusted so that the light incident on the photosensor array 420 is positioned at the center of the photosensor array 420 .

The axis control section 530 controls the axis of the lens barrel section 350 . Axis control section 530 may adjust the axis of lens barrel section 350 so that the light incident on optical sensor array 420 is positioned at the center of optical sensor array 420 . After the axis control unit 530 adjusts the axis of the lens barrel unit 350 based on the position information acquired by the position information acquisition unit 520, for example, so that the light output from the flying object 100 is incident on the lens barrel unit 350. , the axis of the lens barrel 350 is adjusted so that the light incident on the photosensor array 420 is positioned at the center of the photosensor array 420 .

After the axis is adjusted by the axis control unit 530, the aircraft 100 and the ground station 200 establish communication and perform optical communication. The control unit 500 may track the position of the aircraft 100 by continuously receiving the ADS-B information of the aircraft 100 . If an obstacle such as a cloud enters between the flying object 100 and the ground station 200 during optical communication and the optical communication is interrupted, the ground station 200 will follow up based on the ADS-B information. By continuing, communication can be restored quickly. When the obstacle is removed and the optical communication is restored, it is assumed that the optical axis is deviated, but the optical axis can be aligned again by performing the above procedure.

FIG. 7 schematically shows an example of an image 600 captured by the photosensor array 420. As shown in FIG. FIG. 7 illustrates a captured image 600 in which the light 106 from the air vehicle 100 is off the center of the photosensor array 420 .

Axis control unit 530 analyzes captured image 600 to grasp the positional relationship between light 106 in captured image 600 and the center of optical sensor array 420 . Then, the axis controller 530 calculates the adjustment amount of the axis of the lens barrel section 310 or the lens barrel section 350 so that the light 106 and the optical sensor array 420 are aligned. adjust the axis of Thereby, the optical axes can be aligned.

FIG. 8 schematically shows an example of the flow of processing in the communication system 10. As shown in FIG. Here, processing until communication is established between the ground station 200 and the aircraft 100 flying in the sky will be described.

In step (the step may be abbreviated as S) 102 , the ground station 200 transmits position information of the ground station 200 to the aircraft 100 . The ground station 200 transmits position information of the ground station 200 to the aircraft 100 via, for example, a communication satellite. The ground station 200 may transmit the location information of the ground station 200 to the flying object 100 via a management device on the ground that manages the flying object 100 . The aircraft 100 may receive the position information of each of the plurality of ground stations 200 from each of the plurality of ground stations 200 and store it in the database.

In S104, the flying object 100 performs positioning. The flying object 100 performs positioning by receiving GPS (Global Positioning System) signals, for example. At S106, the nearest ground station 200 is confirmed from the location information of the plurality of ground stations 200 stored in the database and the location information of the flying object 100 enthroned at S104.

At S108, ADS-B information including position information of the flying object 100 is transmitted. The ground station 200 receives the ADS-B information transmitted by the aircraft 100 via a communication satellite, a management device of the aircraft 100, or the like.

In S<b>110 , the ground station 200 adjusts the axis of the telescope section 300 based on the position information of the aircraft 100 . The ground station 200 may adjust the axis of the barrel section 310 so as to face the position of the aircraft 100 .

At S<b>112 , the flying object 100 emits initial light based on the position information of the ground station 200 . The aircraft 100 emits initial light toward the position of the ground station 200 . At S114, the ground station 200 reflects the initial light.

In S116, the flying object 100 directs the laser in the direction that maximizes the reflected light. At S118, the air vehicle 100 and the ground station 200 establish communication using a communication protocol.

FIG. 9 schematically shows an example of the configuration of the communication device 130 mounted on the aircraft 100. As shown in FIG. The communication device 130 includes a control section 132 , a communication section 134 , a ground station DB 136 , a positioning section 138 , an ADS-B transmitter 140 , a guide light transmitter 142 and an attitude controller 144 .

The communication unit 134 performs various communications. The communication unit 134 may perform optical communication. A communication unit 134 may perform communication with a communication satellite. The communication unit 134 may perform communication with the management device of the aircraft 100 . The communication unit 134 communicates with the management device of the aircraft 100 via, for example, a feeder link.

The ground station DB 136 stores location information of multiple ground stations 200 . The ground station DB 136 may store location information of a plurality of ground stations 200 received by the communication unit 134 .

The positioning unit 138 performs positioning. The positioning unit 138 performs GPS positioning, for example.

ADS-B transmitter 140 transmits ADS-B information. ADS-B transmitter 140 transmits ADS-B information including position information of aircraft 100 generated by positioning by positioning unit 138 . Note that the communication unit 134 may transmit the position information of the flying object 100 . The communication unit 134 may transmit ADS-B information including position information of the aircraft 100 .

The guide light transmitter 142 transmits guide light using a laser. Also, the guide light transmitter 142 receives the reflected light of the guide light.

The attitude controller 144 controls the attitude of the laser so as to adjust the irradiation direction of the light. The attitude controller 144 controls the attitude of the laser, for example, based on the position information of the ground station 200 to be communicated with. The attitude controller 144 controls the attitude of the laser so that it faces the position of the ground station 200 to be communicated with.

Also, the attitude controller 144 controls the attitude of the laser, for example, so that the laser is directed in the direction in which the reflected light received by the guide light transmitter 142 is maximized. The attitude controller 144, for example, continuously changes the attitude of the laser, continuously measures the intensity of the reflected light received by the guide light transmitter 142, and determines the direction of the laser that maximizes the intensity of the reflected light. Identify.

After the attitude controller 144 directs the laser in the direction that maximizes the intensity of the reflected light, the communication unit 134 establishes communication with the ground station 200 to be communicated with. The communication unit 134 then performs optical communication with the ground station 200 .

FIG. 10 schematically shows an example hardware configuration of a computer 1200 that functions as the control unit 500 or the communication device 130. As shown in FIG. Programs installed on the computer 1200 cause the computer 1200 to act as one or more "parts" of the apparatus of the above embodiments, or cause the computer 1200 to operate or perform operations associated with the apparatus of the above embodiments. Multiple "units" can be executed and/or the computer 1200 can be caused to execute the processes or steps of the processes according to the above embodiments. Such programs may be executed by CPU 1212 to cause computer 1200 to perform certain operations associated with some or all of the blocks in the flowcharts and block diagrams described herein.

Computer 1200 according to this embodiment includes CPU 1212 , RAM 1214 , and graphics controller 1216 , which are interconnected by host controller 1210 . Computer 1200 also includes communication interface 1222 , storage device 1224 , and input/output units such as DVD drives and IC card drives, which are connected to host controller 1210 via input/output controller 1220 . Storage devices 1224 may be hard disk drives, solid state drives, and the like. Computer 1200 also includes legacy input/output units, such as ROM 1230 and keyboard, which are connected to input/output controller 1220 via input/output chip 1240 .

The CPU 1212 operates according to programs stored in the ROM 1230 and RAM 1214, thereby controlling each unit. Graphics controller 1216 retrieves image data generated by CPU 1212 into a frame buffer or the like provided in RAM 1214 or itself, and causes the image data to be displayed on display device 1218 .

Communication interface 1222 communicates with other electronic devices over a network. Storage device 1224 stores programs and data used by CPU 1212 within computer 1200 . The IC card drive reads programs and data from IC cards and/or writes programs and data to IC cards.

ROM 1230 stores therein programs that are dependent on the hardware of computer 1200, such as a boot program that is executed by computer 1200 upon activation. Input/output chip 1240 may also connect various input/output units to input/output controller 1220 via USB ports, parallel ports, serial ports, keyboard ports, mouse ports, and the like.

The program is provided by a computer-readable storage medium such as DVD-ROM or IC card. The program is read from a computer-readable storage medium, installed in storage device 1224 , RAM 1214 , or ROM 1230 , which are also examples of computer-readable storage media, and executed by CPU 1212 . The information processing described within these programs is read by computer 1200 to provide coordination between the programs and the various types of hardware resources described above. An apparatus or method may be configured by implementing information operations or processing according to the use of computer 1200 .

For example, when communication is performed between the computer 1200 and an external device, the CPU 1212 executes a communication program loaded into the RAM 1214 and sends communication processing to the communication interface 1222 based on the processing described in the communication program. you can command. The communication interface 1222 reads transmission data stored in a transmission buffer area provided in a recording medium such as a RAM 1214, a storage device 1224, a DVD-ROM, or an IC card under the control of the CPU 1212, and transmits the read transmission data. Data is transmitted to the network, or received data received from the network is written in a receive buffer area or the like provided on the recording medium.

In addition, the CPU 1212 causes the RAM 1214 to read all or necessary portions of files or databases stored in an external recording medium such as a storage device 1224, a DVD drive (DVD-ROM), an IC card, etc. Various types of processing may be performed on the data. CPU 1212 may then write back the processed data to an external recording medium.

Various types of information, such as various types of programs, data, tables, and databases, may be stored on recording media and subjected to information processing. CPU 1212 performs various types of operations on data read from RAM 1214, information processing, conditional decisions, conditional branching, unconditional branching, and information retrieval, which are described throughout this disclosure and are specified by instruction sequences of programs. Various types of processing may be performed, including /replace, etc., and the results written back to RAM 1214 . In addition, the CPU 1212 may search for information in a file in a recording medium, a database, or the like. For example, when a plurality of entries each having an attribute value of a first attribute associated with an attribute value of a second attribute are stored in the recording medium, the CPU 1212 selects the first attribute from among the plurality of entries. search for an entry that matches the specified condition of the attribute value of the attribute, read the attribute value of the second attribute stored in the entry, and thereby determine the first attribute that satisfies the predetermined condition An attribute value of the associated second attribute may be obtained.

The programs or software modules described above may be stored in a computer-readable storage medium on or near computer 1200 . Also, a recording medium such as a hard disk or RAM provided in a server system connected to a dedicated communication network or the Internet can be used as a computer-readable storage medium, whereby the program can be transferred to the computer 1200 via the network. offer.

The blocks in the flowcharts and block diagrams in this embodiment may represent steps in the process in which the operations are performed or "parts" of the apparatus responsible for performing the operations. Certain steps and "sections" may be provided with dedicated circuitry, programmable circuitry provided with computer readable instructions stored on a computer readable storage medium, and/or computer readable instructions provided with computer readable instructions stored on a computer readable storage medium. It may be implemented by a processor. Dedicated circuitry may include digital and/or analog hardware circuitry, and may include integrated circuits (ICs) and/or discrete circuitry. Programmable circuits, such as Field Programmable Gate Arrays (FPGAs), Programmable Logic Arrays (PLAs), etc., perform AND, OR, EXCLUSIVE OR, NOT AND, NOT OR, and other logical operations. , flip-flops, registers, and memory elements.

A computer-readable storage medium may comprise any tangible device capable of storing instructions to be executed by a suitable device, such that a computer-readable storage medium having instructions stored thereon may be illustrated in flowchart or block diagram form. It will comprise an article of manufacture containing instructions that can be executed to create means for performing specified operations. Examples of computer-readable storage media may include electronic storage media, magnetic storage media, optical storage media, electromagnetic storage media, semiconductor storage media, and the like. More specific examples of computer readable storage media include floppy disks, diskettes, hard disks, random access memory (RAM), read only memory (ROM), erasable programmable read only memory (EPROM or flash memory) , electrically erasable programmable read-only memory (EEPROM), static random access memory (SRAM), compact disc read-only memory (CD-ROM), digital versatile disc (DVD), Blu-ray disc, memory stick , integrated circuit cards, and the like.

The computer readable instructions may be assembler instructions, Instruction Set Architecture (ISA) instructions, machine instructions, machine dependent instructions, microcode, firmware instructions, state configuration data, or instructions such as Smalltalk, JAVA, C++, etc. any source or object code written in any combination of one or more programming languages, including object-oriented programming languages, and conventional procedural programming languages such as the "C" programming language or similar programming languages; may include

Computer readable instructions are used to produce means for a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus, or programmable circuits to perform the operations specified in the flowchart or block diagrams. A general purpose computer, special purpose computer, or other programmable data processor, locally or over a wide area network (WAN) such as the Internet, etc., to execute such computer readable instructions. It may be provided in the processor of the device or in a programmable circuit. Examples of processors include computer processors, processing units, microprocessors, digital signal processors, controllers, microcontrollers, and the like.

Although the present invention has been described above using the embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments. It is obvious to those skilled in the art that various modifications and improvements can be made to the above embodiments. It is clear from the description of the scope of claims that forms with such modifications or improvements can also be included in the technical scope of the present invention.

The execution order of each process such as actions, procedures, steps, and stages in the devices, systems, programs, and methods shown in the claims, the specification, and the drawings is particularly "before", "before etc., and it should be noted that they can be implemented in any order unless the output of the previous process is used in the subsequent process. Regarding the operation flow in the claims, the specification, and the drawings, even if the description is made using "first," "next," etc. for convenience, it means that it is essential to carry out in this order. not a thing

10 communication system 12 light 22 reflected light 100 flying object 106 light 130 communication device 132 control unit 134 communication unit 136 ground station DB 138 positioning unit 140 ADS-B transmitter 142 guide light transmission instrument, 144 attitude controller, 200 ground station, 300 telescope section, 310 lens barrel section, 320 primary mirror, 330 secondary mirror, 332 reflecting surface, 334 reflecting surface, 340 retroreflector, 350 lens tube section, 360 primary mirror, 370 secondary mirror, 372 reflecting surface, 374 reflecting surface, 380 retroreflecting mirror, 400 light receiving unit, 410 optical antenna, 420 sensor array, 430 half mirror, 440 lens, 500 control unit, 510 communication unit, 520 position information acquisition unit, 530 axis control unit 600 captured image 1200 computer 1210 host controller 1212 CPU 1214 RAM 1216 graphic controller 1218 display device 1220 input/output controller 1222 communication interface 1224 storage device 1230 ROM 1240 input/output chip

Claims (12)

a lens barrel;
a primary mirror disposed in the lens barrel and reflecting externally incident light;
a secondary mirror arranged in the lens barrel and reflecting light reflected by the primary mirror;
a light receiving unit that receives light reflected by the secondary mirror;
A light-receiving device comprising: a retroreflecting mirror disposed on the side of the secondary mirror opposite to the side on which the light from the primary mirror is incident, and having a reflecting surface that reflects externally incident light in the incident direction . The size of the retroreflection mirror in a direction intersecting the direction in which light is incident on the barrel portion is equal to or smaller than the size of the secondary mirror in the direction intersecting the direction in which light is incident on the barrel portion. , The light receiving device according to claim 1 . 3. The light receiving device according to claim 1 , wherein said retroreflecting mirror is fixed by magnetic force to a side of said secondary mirror opposite to a side on which light from said primary mirror is incident. 3. The light-receiving device according to claim 1 , wherein said retroreflecting mirror is fixed by screwing to a side of said secondary mirror opposite to a side on which light from said primary mirror is incident. 5. The light-receiving device according to claim 1 , wherein said light-receiving unit has an optical antenna for realizing optical communication using received light. a lens barrel;
a primary mirror disposed in the lens barrel and reflecting externally incident light;
a secondary mirror arranged in the lens barrel and reflecting light reflected by the primary mirror;
a light receiving unit that receives light reflected by the secondary mirror;
a reflective surface disposed on the side of the secondary mirror opposite to the side on which the light from the primary mirror is incident, and which reflects externally incident light to the outside;
with
The light-receiving device, wherein the light-receiving unit has an optical antenna for realizing optical communication using received light. The light receiving unit is
a photosensor array;
7. The light receiving device according to claim 5, further comprising a beam splitter that splits the light reflected by said secondary mirror toward said optical antenna and said optical sensor array. 8. The light receiving device according to claim 7 , further comprising an axis control section that adjusts an axis of said lens barrel so that light incident on said optical sensor array is positioned at the center of said optical sensor array. a location information acquisition unit that acquires location information indicating the location of the transmitter transmitted by the transmitter;
The axis control unit adjusts the axis of the lens barrel so that the light output from the transmitter is incident on the lens barrel based on the position information, and then the light enters the optical sensor array. 9. The light receiving device according to claim 8 , wherein the axis of said lens barrel is adjusted so that is positioned at the center of said optical sensor array. 10. The light receiving device according to claim 9 , wherein said position information obtaining section obtains said position information from ADS-B information including said position information transmitted by said transmitter. 11. The transmitter according to claim 9 , wherein said transmitter is mounted on an aircraft that provides wireless communication services to user terminals within a wireless communication area formed by flying in the stratosphere and irradiating beams toward the ground. photodetector. a light receiving device according to any one of claims 9 to 11 ;
A communication system comprising: the transmitter;

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