JP2017005445A - Optical communication system, optical receiver and optical receiver adjustment method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical communication system, an optical receiver and an optical receiver adjustment method, capable of stably transmitting a large amount of data at high speed through optical transmission using a plurality of optical transmission channels.SOLUTION: The optical communication system includes: an optical transmitter 101 which transmits a plurality of signal beams in parallel; and an optical receiver 201 which receives a plurality of signal beams in parallel. The optical receiver 201 includes: a photodetector unit 210 having a photodetector element group 212 which receives a plurality of signal beams from a plurality of photodetector elements 211 disposed in an array shape; an optical mechanism 220 including a mechanism for forming an image group 312, composed of a plurality of images 311 of the signal beams on the photodetector unit 210, and for variably magnifying the size of the image group, and a mechanism for moving the image group position on the photodetector unit; and a control unit 280 which controls the operation of the optical mechanism 220 on the basis of a detection signal output from each of the plurality of photodetector elements 211, in such a manner that the plurality of signal beams are respectively incident on the plurality of photodetector units 211.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an optical communication system that receives a plurality of signal lights transmitted in parallel from a plurality of light emitting elements arranged in an array in a plurality of light receiving elements arranged in an array, and the plurality of light receiving elements. The present invention relates to an optical receiver provided and an adjustment method in the optical receiver.

  As an optical communication system that transmits a large amount of data at high speed, an optical wireless MIMO (Multiple-Input Multiple-Output) system that transmits a plurality of signal lights in parallel through a plurality of optical paths (a plurality of channels) has been proposed. In this optical communication system, it is possible to increase the data transmission speed through a plurality of optical paths by assigning different data to the plurality of optical paths. However, in general, adjustment for making a plurality of signal lights (a plurality of images formed by a plurality of signal lights) transmitted from a plurality of light emitting elements of an optical transmitter incident on a plurality of light receiving elements of an optical receiver, respectively. (Positioning) is a complicated operation that requires labor and time. Even if the alignment is completed once, it is necessary to make another adjustment by vibration of the optical transmitter or optical receiver, deformation of the structure due to thermal expansion, or movement of the light emitting element or light receiving element. There is a case.

  In order to eliminate such a complicated operation, the optical receiver is a signal light source detected by each of the plurality of light receiving elements based on the detection signals of the plurality of signal lights transmitted from the plurality of light receiving elements. A method of associating a light emitting element and a light receiving element by determining a certain light emitting element and sending the result of the determination to an optical transmitter has been proposed (for example, see Patent Document 1).

International Publication No. 2007/032276

  However, in the optical communication system of Patent Document 1, a plurality of light emitting elements and a plurality of light receiving elements do not correspond one-to-one. For this reason, in this optical communication system, there is a problem that data transmission cannot be performed efficiently by using a plurality of optical paths effectively. In this optical communication system, since the arrangement of the plurality of light emitting elements is different from the arrangement of the plurality of light receiving elements, there are light emitting elements to which the corresponding light receiving elements are not assigned (that is, light emitting elements that are not used for data transmission). As a result, there is a problem that the data transmission speed of the entire optical communication system cannot be sufficiently increased.

  The present invention has been made to solve the above-described problems of the prior art, and by means of a multi-channel optical transmission in which a plurality of signal lights transmitted in parallel from a plurality of light emitting elements are received in parallel by a plurality of light receiving elements, An object is to provide an optical communication system capable of transmitting a large amount of data efficiently, at high speed and stably, an optical receiver constituting a part of the optical communication system, and an adjustment method in the optical receiver. And

  An optical communication system according to the present invention includes an optical transmitter that transmits a plurality of signal lights in parallel, and an optical receiver that receives the plurality of signal lights, and the optical transmitters are arranged in an array. A plurality of light-emitting elements that transmit the plurality of signal lights, and each of the plurality of signal lights is distinguishable from each other. The optical receiver includes a light receiving element group including a plurality of light receiving elements arranged in an array, the light receiving element group receiving the plurality of signal lights, and the plurality of light receiving elements. A detection signal corresponding to the intensity of light incident on each of the plurality of light receiving elements; a light receiving unit configured to form an image group including the plurality of signal light images on the light receiving unit; and the image group And a mechanism for changing the size of the light An optical mechanism having a mechanism for moving the position of the image group, and based on the detection signal output from each of the plurality of light receiving elements so that the plurality of signal lights are respectively incident on the plurality of light receiving elements. And a controller for controlling the operation of the optical mechanism.

  An optical receiver according to the present invention is an optical receiver that receives a plurality of signal lights including identification signal light in parallel, and is a light receiving element group including a plurality of light receiving elements arranged in an array. A light receiving unit including the light receiving element group for receiving a plurality of signal lights, wherein a detection signal corresponding to the intensity of light incident on each of the plurality of light receiving elements is output from the plurality of light receiving elements; An optical mechanism having a mechanism for forming an image group composed of the plurality of signal light images and changing the size of the image group, and a mechanism for moving the position of the image group on the light receiving unit; A control unit that controls the operation of the optical mechanism based on the detection signal output from each of the plurality of light receiving elements so that the signal light is incident on each of the plurality of light receiving elements. And

  An adjustment method in an optical receiver according to the present invention includes: a light receiving unit including a light receiving element group including a plurality of light receiving elements arranged in an array that receives a plurality of signal lights including identification signal light in parallel; An optical mechanism comprising: a mechanism for forming an image group composed of the plurality of signal light images on the part; and a mechanism for changing the size of the image group and a mechanism for moving the position of the image group on the light receiving part. An adjustment method in an optical receiver that controls the operation of the optical mechanism based on a detection signal corresponding to the intensity of light incident on each of the plurality of light receiving elements, the image group on the light receiving unit being Setting the size smaller than the size of the light receiving element group; and reducing the size so that a predetermined signal light of the plurality of signal lights enters a predetermined light receiving element of the light receiving element group. Of the image group And a step of moving a position of the plurality of light receiving elements to enlarge the size of the reduced image group when the predetermined signal light is incident on the predetermined light receiving elements. Each of which is made to enter the signal light.

  According to the optical communication system and the optical receiver of the present invention, a large amount of data is efficiently obtained by optical transmission of a plurality of channels in which a plurality of signal lights transmitted in parallel from a plurality of light emitting elements are received in parallel by a plurality of light receiving elements. And high speed transmission.

  Further, according to the adjustment method in the optical receiver of the present invention, the optical mechanism is configured so that the plurality of signal lights are incident on suitable positions of the plurality of light receiving elements based on the detection signals output from the plurality of light receiving elements. Since it is controlled, even if vibration of the optical transmitter or optical receiver, deformation of the structure due to thermal expansion, or movement occurs, optical transmission of a plurality of channels can be stably maintained.

It is a figure which shows schematically the structure of the optical communication system which concerns on Embodiment 1 to 7 of this invention. It is a figure which shows schematically the structure of the optical mechanism of the optical communication system which concerns on Embodiment 1 of this invention. 6 is a diagram illustrating an example of scaling (reduction) of an image group on a light receiving unit performed by the optical mechanism of the optical receiver according to Embodiment 1. FIG. FIG. 3 is a diagram illustrating an example of scaling (magnification or enlargement) of an image group on a light receiving unit performed by the optical mechanism of the optical receiver in the first embodiment. 6 is a diagram illustrating an example of movement of an image group (at the time of reduction) on the light receiving unit performed by the optical mechanism of the optical receiver in Embodiment 1. FIG. 6 is a diagram illustrating an example of movement of an image group (at the same magnification or during enlargement) on the light receiving unit performed by the optical mechanism of the optical receiver according to Embodiment 1. FIG. 4 is a flowchart illustrating processing that the control unit of the optical receiver according to the first embodiment causes the optical mechanism to execute. 4 is a diagram illustrating a plurality of signal light image groups formed in a light receiving unit of the optical receiver according to Embodiment 1. FIG. 4 is a diagram illustrating a plurality of signal light image groups formed in a light receiving unit of the optical receiver according to Embodiment 1. FIG. 4 is a diagram illustrating a plurality of signal light image groups formed in a light receiving unit of the optical receiver according to Embodiment 1. FIG. 4 is a diagram illustrating a plurality of signal light image groups formed in a light receiving unit of the optical receiver according to Embodiment 1. FIG. 4 is a diagram illustrating a plurality of signal light image groups formed in a light receiving unit of the optical receiver according to Embodiment 1. FIG. 4 is a diagram illustrating a plurality of signal light image groups formed in a light receiving unit of the optical receiver according to Embodiment 1. FIG. It is a figure which shows schematically the structure of the optical mechanism of the optical communication system which concerns on Embodiment 2 of this invention. 6 is a diagram schematically showing a configuration of an optical transmitter of an optical communication system according to a second embodiment. FIG. (A) And (b) is a figure which shows the pilot signal light contained in the some signal light transmitted from the optical transmitter in Embodiment 2. FIG. FIG. 10 is a diagram schematically showing a configuration of an optical receiver of an optical communication system according to a second embodiment. It is a figure which shows schematically the structure of the optical receiver of FIG. 10 is a flowchart illustrating processing that the control unit of the optical receiver according to the second embodiment causes the optical mechanism to execute. 6 is a diagram illustrating a plurality of signal light image groups formed in a light receiving unit of an optical receiver according to Embodiment 2. FIG. 6 is a diagram illustrating a plurality of signal light image groups formed in a light receiving unit of an optical receiver according to Embodiment 2. FIG. 6 is a diagram illustrating a plurality of signal light image groups formed in a light receiving unit of an optical receiver according to Embodiment 2. FIG. 6 is a diagram illustrating a plurality of signal light image groups formed in a light receiving unit of an optical receiver according to Embodiment 2. FIG. 6 is a diagram illustrating a plurality of signal light image groups formed in a light receiving unit of an optical receiver according to Embodiment 2. FIG. 6 is a diagram illustrating a plurality of signal light image groups formed in a light receiving unit of an optical receiver according to Embodiment 2. FIG. 6 is a diagram illustrating a plurality of signal light image groups formed in a light receiving unit of an optical receiver according to Embodiment 2. FIG. 6 is a diagram illustrating a plurality of signal light image groups formed in a light receiving unit of an optical receiver according to Embodiment 2. FIG. 6 is a diagram illustrating a plurality of signal light image groups formed in a light receiving unit of an optical receiver according to Embodiment 2. FIG. (A) And (b) is a figure which shows intensity distribution of the signal light which injects into the light receiving element of the optical receiver in Embodiment 2. FIG. It is a figure which shows schematically the structure of the optical communication system which concerns on Embodiment 3 of this invention. 6 is a diagram illustrating a configuration of a zooming mechanism (zoom mechanism) of an optical mechanism according to Embodiment 3. FIG. 6 is a diagram illustrating a configuration of a zooming mechanism (zoom mechanism) of an optical mechanism according to Embodiment 3. FIG. 10 is a diagram illustrating a configuration of a moving mechanism of an optical mechanism in Embodiment 3. FIG. It is a figure which shows schematically the structure of the optical mechanism of the optical communication system which concerns on Embodiment 4 of this invention. (A)-(d) is a figure which shows the structure of the mirror rocking | fluctuation mechanism of the optical mechanism of the optical communication system which concerns on Embodiment 5 of this invention. It is a figure which shows operation | movement of the mirror rocking | fluctuation mechanism of FIG. It is a figure which shows the use of the optical communication system which concerns on Embodiment 1-5. It is a figure which shows the other use of the optical communication system which concerns on Embodiment 1-5.

<< 1 >> Embodiment 1
FIG. 1 is a diagram schematically showing a configuration of an optical communication system according to an embodiment of the present invention. As shown in FIG. 1, this optical communication system includes an optical transmitter 101 that transmits a plurality of signal lights in parallel and an optical receiver 201 that receives a plurality of signal lights transmitted from the optical transmitter 101 in parallel. And. Visible light can be used as the plurality of signal lights. However, light having a longer wavelength than visible light or light having a shorter wavelength than visible light can be used as the plurality of signal lights. The configuration in FIG. 1 is a common configuration in the first to fifth embodiments.

  The optical transmitter 101 includes a light emitting unit 110. The light emitting unit 110 includes a light emitting element group 112 including a plurality of light emitting elements 111 arranged in an array. The light emitting unit 110 is controlled by the control unit 120. The plurality of light emitting elements 111 transmit a plurality of signal lights, respectively. The plurality of signal lights can be modulated based on different data (transmission data input to the control unit 120). Each of the plurality of signal lights may include identification signal light (for example, pilot signal light) that enables identification of each other. As the light-emitting element 111, an LED (Light Emitting Diode) or a semiconductor laser can be used.

  The optical receiver 201 includes a light receiving unit 210, an optical mechanism 220, and a control unit 280. The light receiving unit 210 includes a light receiving element group 212 including a plurality of light receiving elements 211 arranged in an array. The light receiving element group 212 can receive a plurality of signal lights in parallel. A detection signal having a value (for example, a current value or a voltage value) corresponding to the intensity (light quantity) of light incident on each of the plurality of light receiving elements 211 is output from the plurality of light receiving elements 211. The optical mechanism 220 forms an image group 312 including a plurality of images 311 of a plurality of signal lights on the light receiving unit 210. The optical mechanism 220 includes a mechanism (magnification mechanism) for changing the size of the image group 312 formed on the light receiving unit 210 (for example, the size in the x direction and the y direction) and the position of the image group 312 on the light receiving unit 210. (For example, a position in the x direction and the y direction). The control unit 280 controls the operation of the optical mechanism 220 based on the detection signals output from each of the plurality of light receiving elements 211 so that the plurality of signal lights are incident on the plurality of light receiving elements 211, respectively.

  Although FIG. 1 shows an example in which a plurality of light emitting elements 111 are arranged in 6 rows and 6 columns, the number of rows and the number of columns of the plurality of light emitting elements 111 are not limited to 6 rows and 6 columns. In addition, the number of rows and the number of columns of the plurality of light emitting elements 111 need not be the same. Furthermore, the arrangement of the plurality of light emitting elements 111 may be another arrangement as long as it is a predetermined arrangement.

  1 shows an example in which a plurality of light receiving elements 211 are arranged in 6 rows and 6 columns, the number of rows and the number of columns of the plurality of light receiving elements 211 are not limited to 6 rows and 6 columns. Further, the number of rows and the number of columns of the plurality of light receiving elements 211 need not be the same. Furthermore, the arrangement of the plurality of light receiving elements 211 may be another arrangement as long as it is a predetermined arrangement. In addition, the arrangement of the plurality of light receiving elements 211 preferably corresponds to the arrangement of the plurality of light emitting elements 111 (same or similar shape).

  The scaling mechanism of the optical mechanism 220 is desirably a mechanism that can scale (reduce, reduce, or enlarge) the size of the image group 312 formed on the light receiving unit 210 in the x direction and the y direction. . The moving mechanism of the optical mechanism 220 is desirably a mechanism that can move the position of the image group 312 two-dimensionally in the x and y directions on the light receiving unit 210. However, by adjusting the relationship between the position of the optical transmitter 101 and the position of the optical receiver 201 in advance, if the position adjustment of the image group 312 on the light receiving unit 210 in the x direction or the y direction is unnecessary, The moving mechanism may be a mechanism (fourth embodiment described later) that moves the position of the image group 312 one-dimensionally.

  FIG. 2 is a diagram schematically showing the configuration of the optical mechanism 220 of the optical communication system according to Embodiment 1 of the present invention. The optical receiver of the optical communication system of FIG. 2 is an apparatus that can implement the optical receiver adjustment method according to the present invention. As shown in FIG. 2, the optical mechanism 220 is a zoom mechanism as a magnification changing mechanism that changes the size of the image group 312 on the light receiving unit 210 based on a zoom control signal received from the control unit (280 in FIG. 1). 230. The zoom mechanism 230 includes a slide mechanism 231 that supports one or a plurality of lenses (movable lenses) of the plurality of lenses constituting the zoom mechanism 230 so as to be movable in the direction of the optical axis 233 of the zoom mechanism 230, and a movable lens. And a driving mechanism 232 for applying a driving force in the sliding direction. The drive mechanism 232 includes, for example, a motor as a driving force generation unit and a gear as a driving force transmission unit. FIG. 3 is a diagram illustrating an example of scaling (reduction) of the image group 312 on the light receiving unit 210 performed by the optical mechanism 220 of the optical receiver 201. FIG. 4 is a diagram illustrating an example of scaling (magnification or enlargement) of the image group 312 on the light receiving unit 210 performed by the optical mechanism 220 of the optical receiver 201.

  Further, the optical mechanism 220 includes a movable mirror mechanism 240 that moves the position of the image group 312 on the light receiving unit 210 based on a movement control signal received from the control unit (280 in FIG. 1). The movable mirror mechanism 240 includes a mirror 241, a first support 242 that supports the mirror 241 so as to be able to swing (rotate) in the direction of the arrow D1 about the first axis 242a, and the first support 242. And a second support portion 243 that supports a second axis 243a orthogonal to the first axis 242a so as to be swingable (rotatable) in the direction of arrow D2. The movable mirror mechanism 240 also includes a first mirror driving mechanism 244 that applies a driving force for swinging the mirror 241 about the first axis 242a, and the mirror 241 and the first support portion 242 as the second axis. And a second mirror driving mechanism 245 that applies a driving force for swinging around the center of the shaft 243a. The first mirror driving mechanism 244 and the second mirror driving mechanism 245 can be configured by, for example, a motor as a driving force generation unit and a gear as a driving force transmission unit. However, the structures of the first mirror driving mechanism 244 and the second mirror driving mechanism 245 are not limited to this. FIG. 5 is a diagram illustrating an example of movement (x direction or y direction) of the image group 312 (during reduction) on the light receiving unit 210 performed by the optical mechanism 220 of the optical receiver 201. FIG. 6 is a diagram illustrating an example of movement (x direction or y direction) of the image group 312 (at the same magnification or magnification) on the light receiving unit 210 performed by the optical mechanism 220 of the optical receiver 201.

  FIG. 7 is a flowchart illustrating processing that the control unit 280 of the optical receiver 201 according to Embodiment 1 causes the optical mechanism 220 to execute. 8 to 13 are views showing an image group 312 formed by a plurality of signal lights formed in the light receiving unit 210 of the optical receiver 201. FIG.

  First, the control unit 280 controls the optical mechanism 220 to set the image group 312 on the light receiving unit 210 to a size smaller than the size of the light receiving element group 212. For example, as shown in FIG. Is moved to a predetermined initial position within the movable range (step S1 in FIG. 7). The initial position of the image group 312 is, for example, a position where the image group 312 does not overlap the light receiving element group 212.

  Next, the control unit 280 controls the optical mechanism 220 to move the position of the image group 312 in the −x direction, for example, as illustrated in FIG. 9, and any one of the plurality of signal lights is received. The movement of the position of the image group 312 is stopped when entering one of the light receiving elements 211 of the element group 212 (step S2 in FIG. 7).

  Next, the control unit 280 controls the optical mechanism 220 to move the position of the image group 312 in the + y direction, for example, as shown in FIG. When the light “A” is incident on any one of the light receiving elements 211 in the light receiving element group 212, the movement of the position of the image group 312 is stopped (step S3 in FIG. 7).

  Next, the control unit 280 controls the optical mechanism 220 so that, for example, as shown in FIG. 11, predetermined signal light “A” among the plurality of signal lights is preliminarily stored in the light receiving element group 212. The position of the image group 312 is moved so as to enter the determined light receiving element “a” (step S4 in FIG. 7).

  Next, the control unit 280 controls the optical mechanism 220 so that, for example, as shown in FIG. 12, the plurality of signal lights are reduced so as to be incident on the plurality of light receiving elements in the light receiving element group 212. The size of the image group 312 is enlarged (step S5 in FIG. 7).

Next, the control unit 280 controls the optical mechanism 220 to position the image group 312 in order to improve the intensity of a plurality of signal lights incident on the plurality of light receiving elements 211 as shown in FIG. Is moved in the x direction, the y direction, or both of these directions to finely adjust the position of the image group 312 (step S6 in FIG. 7). Thus, the adjustment for associating the plurality of light emitting elements 111 and the plurality of light receiving elements 211 on a one-to-one basis is completed. Further, the control unit 280 continues to detect the intensity of the plurality of signal lights, and when the value of the detection signal indicating the intensity of the plurality of signal lights decreases, the control unit 280 increases the value of the detection signal. It can be controlled to move the position.

  As described above, according to the optical communication system according to the first embodiment, a plurality of light beams transmitted in parallel from the plurality of light emitting elements 111 (light emitting element group 112) arranged in an array by the optical mechanism 220. The signal light is incident on each of a plurality of light receiving elements 211 (light receiving element group 212) arranged in an array. That is, as shown in FIG. 13, a plurality of images 311 (image group 312) of a plurality of light emitting elements 111 arranged in an array form a plurality of light receiving elements 211 (light receiving element group 212) arranged in an array. Each is overlaid on top. In other words, the plurality of light emitting elements 111 and the plurality of images 311 can be associated one to one. For this reason, the plurality of light emitting elements 111 arranged in an array and the plurality of light receiving elements 211 arranged in an array can be optically communicated with each other in a plurality of channels in a one-to-one correspondence. Therefore, a large amount of data can be transmitted at high speed.

  In addition, the control unit 280 controls the optical mechanism 220 based on the detection signals of the plurality of light receiving elements 211, so that the position or size of the image group 312 does not deviate from the plurality of light receiving elements 211. Can be adjusted. Accordingly, it is possible to automatically compensate for the shift of the plurality of images 311 caused by vibration and thermal deformation of the optical transmitter 101 and the optical receiver 201. In other words, the optical communication system according to Embodiment 1 has improved resistance to signals and thermal deformation. Further, even when at least one of the optical transmitter 101 and the optical receiver 201 moves, it is possible to automatically compensate for the shift of the plurality of images 311.

<< 2 >> Embodiment 2
FIG. 14 is a diagram schematically showing the configuration of the optical mechanism of the optical communication system according to the second embodiment of the present invention. 14, components that are the same as or correspond to the components shown in FIG. 2 are given the same reference numerals as those in FIGS. The optical communication system according to Embodiment 2 has a structure of a movable mirror mechanism (movement mechanism) 240a of the optical mechanism 221 and a mechanism for moving the zoom mechanism 230 in the x and y directions (corresponding to FIG. 33 described later). It differs from the optical communication system according to the first embodiment in that it has a mechanism.

  As shown in FIG. 14, the movable mirror mechanism 240a includes a mirror 241, a first support portion 242 that supports the mirror 241 so as to be swingable (rotatable) about the first support shaft 242a, An arm 251 extending in a direction orthogonal to the first support shaft 242a from the support portion 242 and an arcuate shape extending along a swing direction D1 centered on the first support shaft 242a provided at the tip of the arm 251 A member 252, a magnet 253 fixed to both ends of the arcuate member 252, and a coil 254 disposed so as to surround the magnet 253 are provided. The movable mirror mechanism 240a includes support portions 246 and 247 that support the second support portion 243 that supports the first support portion 242 so that the second support portion 243 can swing (rotate) about the second axis 243a, and the second support portion 243. Arm 261 extending in a direction perpendicular to the second support shaft 243a from the axis 243a, and an arcuate member extending along the swing direction D2 about the second support shaft 243a at the tip of the arm 261 262, a magnet 263 fixed to both ends of the arcuate member 262, and a coil 264 arranged so as to surround the magnet 263. A drive signal is given to the coils 254 and 264 from the control unit 280, and the position of the image group 312 on the light receiving unit 210 can be moved in the x and y directions by swinging in the D1 direction and the D2 direction.

  The slide mechanism includes a motor 232 that moves one or more of a plurality of lenses constituting the zoom mechanism 230 in the direction of the optical axis 233 and a gear 231. This mechanism is, for example, a mechanism described in FIGS. 31 and 32 described later. The motor 232 is controlled by the control unit 280. The zoom mechanism 230 has a mechanism that can move the entire plurality of lenses in the x direction and the y direction. The housing of the zoom mechanism 230 is supported so as to be slidable in the x direction and the y direction. A driving force for parallel movement in the x direction is given by the magnet 271 and the coil 272 surrounding the magnet 271, and the magnet 273 and the coil surrounding the magnet 273. 274 provides a driving force for parallel movement in the y direction. The controller 280 supplies power to the coils 254, 264, 272, and 274 and the motor 232 to flow current, thereby operating the mirror 241, changing the magnification of the zoom mechanism 230, and moving the zoom lens in parallel. .

  FIG. 15 is a diagram schematically showing the configuration of the optical transmitter 101 of the optical communication system according to the second embodiment. Note that the configuration of FIG. 15 can also be applied to optical transmitters in other embodiments. As illustrated in FIG. 15, the optical transmitter 101 includes a plurality of light emitting elements 111, a plurality of light emission driving units 121, a CPU 131, and a memory 132. The CPU 131 reads out and executes a program stored in the memory 132 to execute the program, and controls each of the light emission driving units 121 to cause each of the light emitting elements 111 to perform light emission based on the input transmission data. To do. The optical transmitter 101 can modulate the transmission data and generate signal light in which waveforms having different frequencies are superimposed as pilot signal light in a time division manner.

  FIGS. 16A and 16B are diagrams illustrating pilot signal light included in a plurality of signal lights transmitted from the optical transmitter 101 in the second embodiment. As shown in FIGS. 16A and 16B, the pilot signal light transmitted from the plurality of light emitting elements 111 is composed of, for example, rectangular waves or sine waves 141 to 146 having different frequencies. The pilot signal light is time-division multiplexed on the data modulation waveform signal (transmission data) in each light emission drive unit 121. This time division multiplexing is a method in which, for example, pilot signal light is inserted at a certain time interval, and then a multiplexed signal is transmitted such that a modulated signal follows.

  FIG. 17 is a diagram schematically showing the configuration of the optical receiver 202 of the optical communication system according to the second embodiment. FIG. 17 shows a configuration of an optical receiver 202 having a plurality of receivers 153. The optical receiver 20 includes a plurality of receivers 153, a CPU 150, a memory 151, a display 152, a drive circuit 161, A lens swing mechanism 162, a zoom mechanism 163, a drive circuit 164, and a mirror swing mechanism 165 are provided. The CPU 150 reads out and executes the program stored in the memory 151 to execute the program, and performs control based on a plurality of incident signal lights. The CPU 150 controls the drive circuits 161 and 164 based on the signals generated by the receiving unit 153 based on the detection signals output from the plurality of light receiving elements 211, the lens swing mechanism 162, the zoom mechanism 163, Then, the mirror swinging mechanism 165 is automatically adjusted, and the light emitting elements 111 arranged in an array and the light receiving elements 211 arranged in an array are associated with each other in a one-to-one correspondence.

  FIG. 18 is a diagram schematically showing the configuration of the reception unit 153 in FIG. The operation of the light receiving unit 210 performed by the receiving unit 153, the CPU 150, and the memory 151 shown in FIG. 18 is controlled. The receiving unit 153 includes, for example, a light receiving element 211 such as a photodiode, an operational amplifier 172, a bandpass filter 173, an AGC (Automatic Gain Control) 174, a reference voltage generator 175, a comparator 176, and a sampling clock. A generator 177, a shift register 178, and a ring buffer 179 are included.

  Light (signal light) incident on the light receiving element 211 that is a photodiode is amplified by the operational amplifier 172, passes (extracts) the frequency set by the bandpass filter 173, and is amplified by the AGC 174 so as to have a constant voltage. Then, the comparator 176 performs comparison with the voltage of the reference voltage generator 175 to generate a binary signal, and the binary data is stored in the shift register 178. For example, in the case of an 8-bit shift register, when 8-bit data is accumulated, it is written in the ring buffer 179 as 1 byte.

  FIG. 19 is a flowchart illustrating processing that the control unit 280 of the optical receiver 201 according to the second embodiment causes the optical mechanism to execute. 20 to 28 are diagrams showing a plurality of signal light image groups 312 formed in the light receiving section of the optical receiver 201 according to the second embodiment. FIG. 29 is a diagram illustrating an intensity distribution of signal light input to the light receiving element of the optical receiver 201 according to the second embodiment. The following description is basically the same as the processing in the first embodiment. However, in the following description, the case of a light receiving element of 4 rows and 4 columns and an image 311 of 4 rows and 4 columns is described. This will be described in more detail.

  Next, the operation of the optical communication system according to Embodiment 2 will be described in detail. First, the optical transmitter 101 transmits a plurality of signal lights corresponding to the plurality of light emitting elements 111 to the optical receiver 201 from the plurality of light emitting elements 111 (light emitting element group 112) arranged in an array ( Step S11).

  The control unit 280 of the optical receiver 201 sets the zoom magnification (magnification) in the zoom function of the optical mechanism 220 to, for example, the lowest magnification within the variable range of the zoom magnification (step S12). At this time, as shown in FIG. 20, the image group 312 composed of the plurality of images 311 of the plurality of signal lights on the light receiving unit 210 is arranged at a position that does not overlap the light receiving element group 212 composed of the plurality of light receiving elements 211. The

  Next, the control unit 280 drives the movable mirror mechanism 240a of the optical mechanism 220 and swings the mirror until it is detected that signal light has entered one of the plurality of light receiving elements 211. The image group 312 is moved in one or both of the x direction and the y direction (step S13). At this time, as shown in FIG. 21, the images “E” and “I” in the plurality of signal light image groups 312 on the light receiving unit 210 are the light receiving elements “p” in the plurality of light receiving elements 211. Overlapping. Further, if the detection signal is not output from the light receiving unit 210 even if the mirror 241 of the movable mirror mechanism 240a is operated within the maximum allowable swing range (NO in step S14), it is determined that there is no signal light, and reception is not performed. End the operation for. In this case, no signal light could be incident on any of the plurality of light receiving elements 211 arranged in an array.

  If YES in step S14, the control unit 280 immediately stops the swing of the mirror 241 when the light of the light emitting element 111 is incident on at least one of the plurality of light receiving elements 211, and The movement is stopped (step S15). At this time, as shown in FIG. 21, for example, signals “E” and “I” of the light emitting elements are detected in the light receiving element “p” on the light receiving unit 210.

Next, the control unit 280 performs processing for finding pilot signal light as an identification signal included in the signal light transmitted from the light emitting element 111. For example, the control unit 280 passes the band-pass filter (173 in FIG. 18) of the reception unit (153 in FIG. 18) in order to find the pilot signal light X _A [Hz] included in the image “A” of the light emitting element. The center frequency of the band is set to X _A [kHz], and the bandwidth of the pass band is set to W [kHz] (step S16).

  Next, the control unit 280 swings the mirror 241 of the optical mechanism 220 until the image “A” made of signal light is incident on any of the plurality of light receiving elements 211 until the image group is detected. 312 is moved (step S17). At this time, as shown in FIG. 22 and FIG. 23, the image “A” in the image group 312 composed of a plurality of signal lights on the light receiving unit 210 is the light receiving element “l” in the plurality of light receiving elements 211. (Step S17).

  Next, the control unit 280 sets bandpass frequencies for all the reception units (153 in FIG. 18) (step S18). For example, different band pass frequencies are set so that a plurality of images (“A” to “P” in FIG. 20) can be identified by a plurality of light receiving elements (“a” to “p” in FIG. 20). .

  Next, the control unit 280 calculates the movement amount Qy in the y direction and the movement amount Qx in the x direction of the image group by calculation. For example, when the light of the light emitting element 111 of the image “A” enters the light receiving element “l”, the control unit 280 causes the light of the light emitting element 111 of the image “A” to enter the light receiving element “a”. The amount by which the mirror 241 is moved is calculated based on the zoom magnification. Next, the control unit 280 moves the image group 312 so that the signal light A is incident on the light receiving element a by swinging the mirror 241 of the optical mechanism 220 (step S19). At this time, as shown in FIGS. 23 to 25, the image “A” in the image group 312 made up of a plurality of signal lights on the light receiving unit 210 is the light receiving element “a” in the plurality of light receiving elements 211. Overlapping. The controller 280 moves the mirror to stop the movement of the mirror 241 when the light of the light emitting element 111 corresponding to the image “A” enters the light receiving element “a” (step S20). At this time, as shown in FIG. 25, the image “A” in the plurality of signal light image groups 312 on the light receiving unit 210 overlaps the light receiving element “a” in the plurality of light receiving elements 211.

  Next, the control unit 280 increases the zoom magnification little by little (step S21). At this time, as shown in FIG. 26, the plurality of signal light image groups 312 on the light receiving unit 210 is enlarged.

  Next, when the light (“B” to “P”) transmitted from another light emitting element enters “p” from the corresponding light receiving element “b”, the control unit 280 fixes the zoom magnification ( Step S22). This state is shown in FIG. Further, the intensity of the detection signal of the light receiving element at this time has a relatively low intensity distribution as shown in FIG.

  Next, the control unit 280 causes the mirror 241 or the lens swinging mechanism 162 so that the detection signals from the light receiving elements “a” to “p” have a relatively high intensity distribution as shown in FIG. To finely adjust the position of the image group 312 (step S23). This adjustment includes a process of focusing so that the peak value of the signal light having a Gaussian distribution stands steeply. Thus, the adjustment by the optical receiver 202 is completed.

  As described above, according to the optical communication system according to the second embodiment, a plurality of light beams transmitted in parallel from the plurality of light emitting elements 111 (light emitting element group 112) arranged in an array by the optical mechanism 220. The signal light is incident on each of a plurality of light receiving elements 211 (light receiving element group 212) arranged in an array. That is, as shown in FIG. 128, a plurality of images 311 (image group 312) of a plurality of light emitting elements 111 arranged in an array form a plurality of light receiving elements 211 (light receiving element group 212) arranged in an array. Each is overlaid on top. In other words, the plurality of light emitting elements 111 and the plurality of images 311 can be associated one to one. For this reason, the plurality of light emitting elements 111 arranged in an array and the plurality of light receiving elements 211 arranged in an array can be optically communicated with each other in a plurality of channels in a one-to-one correspondence. Therefore, a large amount of data can be transmitted at high speed.

  In addition, the control unit 280 controls the optical mechanism 220 based on the detection signals of the plurality of light receiving elements 211, so that the position or size of the image group 312 does not deviate from the plurality of light receiving elements 211. Can be adjusted. Accordingly, it is possible to automatically compensate for the shift of the plurality of images 311 caused by vibration and thermal deformation of the optical transmitter 101 and the optical receiver 201. In other words, the optical communication system according to Embodiment 1 has improved resistance to signals and thermal deformation. Further, even when at least one of the optical transmitter 101 and the optical receiver 201 moves, it is possible to automatically compensate for the shift of the plurality of images 311.

<< 3 >> Embodiment 3
The optical communication system according to the third embodiment is different from the first and second embodiments in the structure of the optical mechanism 320.

  FIG. 30 is a diagram schematically showing a configuration of the optical communication system according to the third embodiment of the present invention. 30, components that are the same as or correspond to the components shown in FIG. 2 are given the same reference numerals as those in FIG. As shown in FIG. 30, the optical receiver 203 of the optical communication system according to the third embodiment includes, as the optical mechanism 320, the housing 301 of the zoom mechanism 230 in the x direction orthogonal to the optical axis 233, the optical axis, The second embodiment is different from the first embodiment in having a mechanism for moving in the y direction orthogonal to both the x direction. In the optical communication system according to Embodiment 3, the position of the image group 312 on the light receiving unit 210 is two-dimensionally moved on the light receiving unit 210 by moving the housing 301 of the zoom mechanism 230 in the x direction and the y direction. Can be moved.

  FIG. 31 is a diagram illustrating a configuration of the zoom mechanism 230 of the optical receiver 203 of the optical communication system according to the third embodiment. FIG. 32 is a diagram illustrating a configuration of the zoom mechanism 230 of the optical receiver 203 of the optical communication system according to the third embodiment. As shown in FIGS. 31 and 32, the convex lens 302 and the convex lens 303 are fixed to the housing 301 with a ring 306 and a ring 307. The concave lens 304 and the convex lens 303 are slidably fixed to the sliding rod 308 by the sliding body 310 and the sliding body 309. The lower side is fixed to the two ball screw shafts 311 and 312 by the ball screw. It is fixed with nuts 313 and 314. The ball screw shafts 311 and 312 have different screw pitches. When the rotation speed is the same, the movement distance of the ball screw shaft 312 in the optical axis 233 direction is longer than the movement distance of the ball screw shaft 311 in the optical axis 233 direction. It is comprised so that it may become. Gears 317 and 316 are fixed to end portions of the ball screw shafts 311 and 312, and the rotational driving force of the motor 232 is transmitted to the gears 317 and 316 via the reduction gear 315 and the like. With such a structure, the position of the convex lens 302 and the convex lens 303 in the optical axis 233 direction can be changed by the rotation of the motor 232. FIG. 31 shows the arrangement of the convex lens 302 and the convex lens 303 in the case of a wide angle. As shown in FIG. 32, for example, when the zoom magnification becomes 10 times as shown in FIG. 32, the convex lens 302 and the convex lens 303 move to the right side in the figure, but the ball screw shafts 311 and 312 Depending on the pitch of the screw, the distance between the convex lens 302 and the convex lens 303 moves closer to that of FIG. In this way, a cylindrical shape sandwiched between two convex lenses 302 and 303 from a wide angle to a telephoto position by a motor 232 as a driving force generation unit and a driving force transmission mechanism such as a gear, a ball screw shaft, and a ball screw nut. In this lens component, the concave lens 304 and the convex lens 305 move by a predetermined distance, and the zoom magnification can be changed electrically.

  FIG. 33 is a diagram illustrating a configuration of a moving mechanism of the optical receiver 203 of the optical communication system according to the third embodiment. The housing 301 shown in FIGS. 31 and 32 includes a motor 321 as a driving force generator, gear trains 322, 323, and 324 as a driving force transmission mechanism, and a ball screw shaft 325 shown in FIG. The support block 327 engaged with the ball screw shaft 327 moves in the x direction shown in FIGS. The housing 301 includes a motor 331 as a driving force generator fixed to the support block 327, gear trains 321 and 333 as a driving force transmission mechanism, a ball screw shaft 334, a slide shaft 335, and a ball screw. The support block 336 engaged with the shaft 324 moves along the slide shaft 335 (in the y direction shown in FIGS. 30 and 33). As described above, in the optical communication system according to Embodiment 3, the position of the image group 312 on the light receiving unit 210 is moved by moving the housing 301 of the zoom mechanism 230 in the x direction and the y direction. It can be moved two-dimensionally above.

  The optical communication system according to the third embodiment is the same as the optical communication system according to the first and second embodiments except that the optical mechanism 320 shown in FIGS. 30 to 33 is employed.

<< 4 >> Embodiment 4
In the first and second embodiments, the movable mirror mechanism of the optical mechanism 220 displays a plurality of images 311 (image group 312) formed on the light receiving unit 210 by a plurality of signal lights in the x direction on the light receiving unit 210. And a function of moving in the y direction (that is, in a two-dimensional direction). On the other hand, the movable mirror mechanism 440 of the optical mechanism 420 of the optical receiver 204 of the optical communication system according to the fourth embodiment has a plurality of images 311 (image group 312) formed on the light receiving unit 210 by a plurality of signal lights. ) In one direction on the light receiving unit 210 (for example, the x direction or the y direction).

  FIG. 34 is a diagram schematically showing a configuration of the optical communication system according to the fourth embodiment of the present invention. 34, the same or corresponding components as those in FIG. 2 are denoted by the same reference numerals as those in FIG. As shown in FIG. 34, the movable mirror mechanism 440 includes a mirror 441, a support portion 442 that supports the mirror 441 so as to be able to swing (turn), and a driving force for swinging the mirror 441 in the direction of the arrow 443. And a driving force generator 444 that provides For example, the driving force generation unit 444 can adopt the same structure as the driving force generation unit shown in FIG. 2 or FIG.

  34, for example, the optical transmitter 101 and the optical receiver 204 are arranged so that the positions in the x direction of the plurality of images 311 (image group 312) formed on the light receiving unit 210 are fixed. And can be employed when only the positions in the y direction of the plurality of images 311 (image group 312) are moved.

  The optical communication system according to the fourth embodiment has a narrower application range than the optical communication systems according to the first and second embodiments, but can simplify the configuration.

  The optical communication system according to the fourth embodiment is the same as the optical communication system according to the first and second embodiments, except that the optical mechanism 420 is used instead of the optical mechanism 220.

<< 5 >> Embodiment 5
The optical communication system according to the fifth embodiment is different from the first and second embodiments in that the movable mirror mechanism in the first and second embodiments is replaced with a movable mirror swing mechanism described below.

  FIGS. 35A to 35D are diagrams showing a configuration of a mirror swinging mechanism 500 as a movable mirror mechanism of the optical mechanism of the optical communication system according to Embodiment 5 of the present invention. The movable mirror mechanism used in the first and second embodiments can be replaced with the mirror swing mechanism 500 shown in FIGS. As shown in the plan view of FIG. 35A and the longitudinal cross-sectional view of FIG. 35B (the plane cut along line segment 510-510 in FIG. 35A), the mirror swing mechanism 500 includes a mirror. The disc-shaped movable plate 501 and the hemispherical support portion are engaged with the concave portion having a hemispherical diameter on the lower surface of the movable plate 501, so that the movable plate 501 can swing freely (for example, an arrow 511 in FIG. 35B). A free joint 502 that supports the free joint 502 and a support member 503 that supports the free joint 502. A plurality of magnets 504 (FIG. 35C) are fixed to the lower surface of the movable plate 501, and a plurality of coils 505 (FIG. 35) are arranged on the upper surface of the support member 505 so as to face the plurality of magnets 504. (D)) is fixed.

  FIG. 36 is a diagram showing the function of the mirror swing mechanism 500 shown in FIGS. 35 (a) to 35 (d). By controlling the value of current supplied to the plurality of coils 505, the tilt angle of the movable plate 501 provided with a mirror can be minutely changed in an arbitrary direction. As a result, as shown in FIG. 36, the incident signal light 521 can be reflected by the mirror and the reflected signal light 522 can be directed in a desired direction.

  The optical communication system according to the fifth embodiment is the same as the optical communication system according to the first and second embodiments, except that a movable mirror swing mechanism is employed.

<6> Modified example.
FIG. 37 is a diagram illustrating an example of the use of the optical communication system according to the first to fifth embodiments. In the example of FIG. 37, the optical communication system according to the first to fifth embodiments is applied to a video transmission system. A video transmission system shown in FIG. 37 includes a camera 601 as an imaging device that generates video data of a subject by photographing the subject, and a television monitor 602 as a video display device placed at a location away from the camera 601. And an optical transmission unit 603. In this video transmission system, the optical transmission unit 603 includes any one of the optical transmitter 101 and the optical receiver 201 (or any one of 202, 203, 204, and 205) according to the first to fifth embodiments. Yes. In this case, the user of the video transmission system is configured so that the plurality of signal lights 604 transmitted in parallel from the plurality of light emitting elements 111 of the optical transmitter 101 are generally directed to the plurality of light receiving elements 211 of the optical receiver 201. The positions and orientations (directions) of the optical transmitter 101 and the optical receiver 201 are adjusted. The optical receiver 201 has a plurality of signal lights 604 (a plurality of images formed by signal lights) transmitted in parallel to the plurality of light receiving elements 211 on a one-to-one basis by the adjustment method described in the first to fifth embodiments. The operation of the optical mechanism (220 in FIG. 1) is controlled so as to be incident in accordance with.

  According to this video transmission system, a plurality of channels of optical transmission in which a plurality of signal lights 604 transmitted in parallel from a plurality of light emitting elements 111 of the optical transmitter 101 are received in parallel by a plurality of light receiving elements 211 of the optical receiver 201. Thus, a large amount of data can be transmitted efficiently and at high speed.

  Further, according to this video transmission system, based on the detection signals output from the plurality of light receiving elements 211, the plurality of signal lights 604 are incident on suitable positions (positions where the detection signals are increased) of the plurality of light receiving elements 211. Since the optical mechanism (220 in FIG. 1) is controlled, the vibration of the optical transmitter 101 or the optical receiver 201, the deformation of the structure of the optical transmitter 101 or the optical receiver 201 due to thermal expansion, or the optical transmitter Even when the position of the optical receiver 201 or the position of the optical receiver 201 is moved, parallel optical transmission of a plurality of channels can be stably maintained.

  Moreover, this video transmission system can be used not only in the air but also in the water.

  FIG. 38 is a diagram illustrating another example of the use of the optical communication system according to the first to fifth embodiments. In the example of FIG. 38, the optical communication system according to the first to fifth embodiments is applied to an inter-building optical communication system that performs communication between two buildings 701 and 702 by visible light communication that is wireless communication. . The optical transmission unit 703 of the inter-building optical communication system illustrated in FIG. 38 includes the optical transmitter 101 and the optical receiver 201 (or any of 202, 203, 204, and 205) according to the first to fifth embodiments. And have. In this case, the user of the optical communication system between buildings is configured so that the plurality of signal lights 704 transmitted in parallel from the plurality of light emitting elements 111 of the optical transmitter 101 are generally directed to the plurality of light receiving elements 211 of the optical receiver 201. In addition, the positions and orientations (directions) of the optical transmitter 101 and the optical receiver 201 are adjusted. The optical receiver 201 has a plurality of signal lights 704 (a plurality of images formed by signal lights) transmitted in parallel to the plurality of light receiving elements 211 on a one-to-one basis by the adjustment method described in the first to fifth embodiments. The operation of the optical mechanism (220 in FIG. 1) is controlled so as to be incident in accordance with.

  According to this inter-building optical communication system, a plurality of signal lights 704 transmitted in parallel from a plurality of light emitting elements 111 of the optical transmitter 101 are received in parallel by a plurality of light receiving elements 211 of the optical receiver 201. With optical transmission, a large amount of data can be transmitted efficiently and at high speed.

  Further, according to this inter-building optical communication system, based on the detection signals output from the plurality of light receiving elements 211, the plurality of signal lights 704 are sent to suitable positions of the plurality of light receiving elements 211 (positions at which the detection signals increase). Since the optical mechanism (220 in FIG. 1) is controlled so as to be incident on the light, the vibration of the building 701 or 702, the vibration of the optical transmitter 101 or the optical receiver 201 due to wind, the optical transmitter 101 or the optical receiver due to thermal expansion Even when the structure of the apparatus 201 is changed or the position of the optical transmitter 101 or the optical receiver 201 is moved, parallel optical transmission of a plurality of channels can be stably maintained.

  DESCRIPTION OF SYMBOLS 101 Optical transmitter, 110 Light emitting part, 111 Light emitting element, 112 Light emitting element group, 120 Control part, 201-206 Optical receiver, 210 Light receiving part, 211 Light receiving element, 212 Light receiving element group, 220, 220a, 320, 420 Optical Mechanism, 230 zoom mechanism (magnification mechanism), 240 movable lens mechanism (movement mechanism), 241 mirror, 242 first support part, 242a first axis, 243 second support part, 243a second axis, 244 1st drive mechanism, 245 2nd drive mechanism, 280 control part, 311 image, 312 image group.

Claims (15)

An optical transmitter for transmitting a plurality of signal lights in parallel;
An optical receiver for receiving the plurality of signal lights;
With
The optical transmitter includes a light emitting unit including a light emitting element group composed of a plurality of light emitting elements arranged in an array,
The plurality of light emitting elements respectively transmit the plurality of signal lights,
Each of the plurality of signal lights includes an identification signal light that enables identification of each other,
The optical receiver is:
A light-receiving element group comprising a plurality of light-receiving elements arranged in an array, the light-receiving element group receiving the plurality of signal lights, and detecting corresponding to the intensity of light incident on each of the plurality of light-receiving elements A light receiving unit that outputs signals from the plurality of light receiving elements;
An optical mechanism having a mechanism for forming an image group composed of the plurality of signal light images on the light receiving unit and changing the size of the image group, and a mechanism for moving the position of the image group on the light receiving unit. When,
A controller that controls the operation of the optical mechanism based on the detection signals output from each of the plurality of light receiving elements so that the plurality of signal lights are respectively incident on the plurality of light receiving elements. An optical communication system. The control unit controls the operation of the optical mechanism,
The image group on the light receiving unit is set to a size smaller than the size of the light receiving element group,
The position of the reduced image group is moved so that a predetermined signal light of the plurality of signal lights is incident on a predetermined light receiving element of the light receiving element group,
When the predetermined signal light is incident on the predetermined light receiving element, the reduced size of the image group is enlarged and the plurality of signal lights are respectively incident on the plurality of light receiving elements. The optical communication system according to claim 1. The control unit controls the operation of the optical mechanism,
The image group on the light receiving unit is set to a size smaller than the size of the light receiving element group,
Moving the position of the image group, and stopping the movement of the position of the image group when any of the plurality of signal lights is incident on any light receiving element of the light receiving element group;
The position of the reduced image group is moved so that a predetermined signal light of the plurality of signal lights is incident on a predetermined light receiving element of the light receiving element group,
When the predetermined signal light is incident on the predetermined light receiving element, the reduced size of the image group is enlarged and the plurality of signal lights are respectively incident on the plurality of light receiving elements. The optical communication system according to claim 1. The control unit controls the operation of the optical mechanism,
The image group on the light receiving unit is set to a size smaller than the size of the light receiving element group,
Moving the position of the image group, and stopping the movement of the position of the image group when any of the plurality of signal lights is incident on any light receiving element of the light receiving element group;
The position of the reduced image group is moved so that a predetermined signal light of the plurality of signal lights is incident on any one of the light receiving elements of the light receiving element group,
The position of the reduced image group is moved so that a predetermined signal light of the plurality of signal lights is incident on a predetermined light receiving element of the light receiving element group,
When the predetermined signal light is incident on the predetermined light receiving element, the reduced size of the image group is enlarged and the plurality of signal lights are respectively incident on the plurality of light receiving elements. The optical communication system according to claim 1.   The control unit enlarges the size of the reduced image group and causes the plurality of signal lights to enter the plurality of light receiving elements, and then outputs the detection from each of the plurality of light receiving elements. 5. The optical communication system according to claim 2, wherein the position of the image group is moved by controlling the operation of the optical mechanism based on a signal. 6.   6. The optical communication system according to claim 1, wherein the identification signal light is pilot signal light having a unique pattern for each of the plurality of signal lights.   The mechanism for moving the position of the image group in the optical mechanism includes a mechanism for moving the position of the image group in a two-dimensional direction on the light receiving unit. The optical communication system according to item.   2. The mechanism for scaling the size of the image group in the optical mechanism includes a zoom mechanism for scaling the size of the image group based on a zoom control signal received from the control unit. 8. The optical communication system according to any one of items 1 to 7.   The mechanism that moves the position of the image group in the optical mechanism includes a lens that forms a part of the zoom mechanism in a direction orthogonal to the optical axis of the zoom mechanism based on a movement control signal received from the control unit. The optical communication system according to claim 8, further comprising a shift mechanism.   The mechanism for moving the position of the image group in the optical mechanism includes a mechanism for shifting the zoom mechanism in a direction perpendicular to the optical axis of the zoom mechanism based on a movement control signal received from the control unit. The optical communication system according to claim 8, characterized in that:   The mechanism for moving the position of the image group in the optical mechanism includes a movable mirror mechanism for moving the position of the image group based on a movement control signal received from the control unit. The optical communication system according to any one of 10. The movable mirror mechanism is
Mirror,
A first support portion that supports the mirror so as to be swingable about a first axis;
A second support part that supports the first support part so as to be swingable about a second axis perpendicular to the first axis;
The optical communication system according to claim 11, comprising: An optical receiver for receiving a plurality of signal lights including identification signal light in parallel,
A light-receiving element group comprising a plurality of light-receiving elements arranged in an array, the light-receiving element group receiving the plurality of signal lights, and detecting corresponding to the intensity of light incident on each of the plurality of light-receiving elements A light receiving unit that outputs signals from the plurality of light receiving elements;
An optical mechanism having a mechanism for forming an image group composed of the plurality of signal light images on the light receiving unit and changing the size of the image group, and a mechanism for moving the position of the image group on the light receiving unit. When,
A control unit for controlling the operation of the optical mechanism based on the detection signals output from each of the plurality of light receiving elements so that the plurality of signal lights are respectively incident on the plurality of light receiving elements;
An optical receiver comprising: The control unit controls the operation of the optical mechanism,
The image group on the light receiving unit is set to a size smaller than the size of the light receiving element group,
The position of the reduced image group is moved so that a predetermined signal light of the plurality of signal lights is incident on a predetermined light receiving element of the light receiving element group,
When the predetermined signal light is incident on the predetermined light receiving element, the reduced size of the image group is enlarged and the plurality of signal lights are respectively incident on the plurality of light receiving elements. The optical receiver according to claim 13. A light receiving unit including a light receiving element group including a plurality of light receiving elements arranged in an array for receiving a plurality of signal lights including identification signal light in parallel, and an image of the plurality of signal lights on the light receiving unit An optical mechanism having a mechanism for forming an image group and changing the size of the image group and a mechanism for moving the position of the image group on the light receiving unit, and is incident on each of the plurality of light receiving elements An adjustment method in an optical receiver that controls the operation of the optical mechanism based on a detection signal corresponding to the intensity of light,
Setting the image group on the light receiving unit to a size smaller than the size of the light receiving element group;
Moving the position of the reduced image group so that a predetermined signal light of the plurality of signal lights is incident on a predetermined light receiving element of the light receiving element group;
When the predetermined signal light is incident on the predetermined light receiving element, the reduced size of the image group is enlarged and the plurality of signal lights are respectively incident on the plurality of light receiving elements. And an adjustment method in the optical receiver.

Images