JP4038513B2 - Optical wireless communication device - Google Patents

Description

  The present invention relates to an optical wireless communication apparatus.

Currently, in space optical communication, development of a fiber-coupled optical wireless communication apparatus that allows received signal light to directly enter an optical fiber is being promoted. In such an optical wireless communication apparatus, it is necessary to appropriately cause the received signal light to enter the optical fiber even when a positional deviation of the signal light transmitted due to various factors occurs. For this reason, conventionally, it has been proposed to adjust the position of the incident end of the optical fiber so that the received signal light is appropriately incident on the optical fiber (see, for example, Patent Document 1 below).
JP 2002-164852 A

  However, the above method has a problem that the position adjustment range is not sufficient, and the incident angle of the signal light incident on the incident end is not appropriate even if the position is present. In addition, when the signal light is not properly incident on the optical fiber as described above, there is a problem that the aberration of the optical system increases.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an optical wireless communication apparatus that allows a received signal light to appropriately enter an incident end of an optical fiber. To do.

  An optical wireless communication apparatus according to the present invention receives a signal light that has arrived as a wireless communication signal, reduces the diameter of the signal light and emits it as parallel light, and a signal emitted by the reduction optical system And an optical fiber having an incident end for allowing light to enter, and an optical fiber support for supporting the optical fiber in a state where the incident end is rotatable around the vicinity of the parallel light exit surface in the reduction optical system. It is characterized by.

  In this optical wireless communication apparatus, it is possible to adjust the position by rotating the incident end of the optical fiber around the vicinity of the parallel light exit surface in the reduction optical system. As a result, the optical axis of the parallel light and the optical axis of the incident end of the optical fiber can be made to coincide with each other so that the incident angle of the signal light to the incident end can be made appropriate. It becomes possible. Therefore, the received signal light can be appropriately incident on the incident end of the optical fiber.

  The reduction optical system receives the signal light that has arrived as a wireless communication signal and emits the signal light so that the diameter of the signal light is reduced, and the signal light emitted from the condensing lens is incident and parallel And a collimating lens that emits light as light emitted from the reduction optical system. According to this configuration, the condensing optical system can be easily configured.

  An optical wireless communication apparatus according to the present invention includes a collimating lens that receives signal light and emits it as parallel light, a collimating lens support that supports the collimating lens, and an incident end that makes the signal light incident thereon. And an optical fiber that supports the optical fiber in a state in which the incident end is rotatable about the vicinity of the collimator lens support portion as a center of rotation. And a support part.

  In this optical wireless communication apparatus, the position of the incident end of the optical fiber can be adjusted by rotating the vicinity of the collimating lens support portion around the rotation center. As a result, the optical axis of the parallel light and the optical axis of the incident end of the optical fiber can be made to coincide with each other so that the incident angle of the signal light to the incident end can be made appropriate. It becomes possible. Therefore, the received signal light can be appropriately incident on the incident end of the optical fiber.

  Moreover, it is preferable that an optical fiber support part supports the said optical fiber in the state which can rotate the said incident end with respect to the said rotating shaft by making the axis line which passes the said vicinity into a rotating shaft. According to this configuration, it is possible to easily configure the optical fiber support portion that can rotate the incident end of the optical fiber around the collimating lens support portion in the vicinity of the parallel light exit surface in the reduction optical system. it can.

  In addition, the optical fiber lens and the optical fiber lens that collect the signal light incident on the incident end of the optical fiber and enter the incident end of the optical fiber coincide with the optical axis of the incident end. An optical fiber fixing portion that is positioned and fixed to the incident end in such a manner that the optical fiber support portion can rotate the incident end by supporting the optical fiber fixing portion in a rotatable state. It is preferable to support the optical fiber in a state. According to this configuration, for example, even when the diameter of the core of the optical fiber is small, the signal light can be reliably incident on the optical fiber. Further, since the optical fiber support portion may directly support the optical fiber fixing portion, the optical fiber can be supported more reliably and easily.

  In addition, the optical wireless communication apparatus rotates the incident end based on the signal light intensity detecting means for detecting the intensity of the signal light incident on the optical fiber, and the signal light intensity detected by the signal light intensity detecting means. It is preferable to further include incident end position control means for controlling the position of the incident end of the optical fiber. According to this configuration, automatic position control of the incident end of the optical fiber is possible, and more accurate and real-time position control is possible. Therefore, the received signal light can be incident on the optical fiber more appropriately.

  According to the present invention, it is possible to adjust the position of the incident end of the optical fiber by rotating the incident end of the optical fiber around the predetermined position located closer to the reduction optical system than the incident end. As a result, the optical axis of the parallel light and the optical axis of the incident end of the optical fiber can be made to coincide with each other so that the incident angle of the signal light to the incident end can be made appropriate. It becomes possible. Therefore, the received signal light can be appropriately incident on the incident end of the optical fiber.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of an optical wireless communication apparatus according to the present invention will be described in detail with reference to the drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted. Further, the dimensional ratios in the drawings do not necessarily match those described.

  FIG. 1 is a block diagram schematically showing an embodiment of an optical wireless communication apparatus 10 according to the present invention. The optical wireless communication device 10 receives the signal light projected by the optical wireless communication device of the communication partner as a wireless communication signal. The received signal light is output to a network such as a LAN (Local Area Network) connected to the optical wireless communication apparatus 10. It should be noted that the optical wireless communication device and the optical wireless communication device 10 of the communication partner are installed at positions where light can be transmitted and received with each other so that spatial light communication is possible. The optical wireless communication apparatus 10 preferably has a light projecting (transmitting) function as well as a light receiving (receiving) function.

  Hereinafter, the configuration of the optical wireless communication apparatus 10 will be described. As shown in FIG. 1, an optical wireless communication apparatus 10 includes a condenser lens 11, a collimator lens 12, an optical fiber 13, a fiber collimator 14, a fiber coupler 15, a light intensity monitor 16, a CPU (Central Processing Unit). Unit) 17. The optical wireless communication apparatus 10 is configured by housing these constituent elements in, for example, a box-shaped housing having a surface that receives signal light.

  The condensing lens 11 and the collimating lens 12 receive a signal light transmitted as a wireless communication signal transmitted from an optical wireless communication device of a communication partner, and reduce the diameter of the signal light and emit it as parallel light. Configure. The condensing lens 11 is a lens that receives the signal light that has arrived as a wireless communication signal on one surface and emits the received signal light from the other surface so that the diameter thereof is reduced. The condenser lens 11 is positioned and fixed by a lens holder (not shown in FIG. 1) or the like fixed in the housing of the optical wireless communication apparatus 10. Specifically, as the condenser lens 11, it is preferable to use a lens having convex surfaces on both sides as shown in FIG. Moreover, the condensing lens 11 may be comprised as a condensing lens group which consists of a some lens.

  As shown in FIG. 1, the collimating lens 12 is a lens smaller than the condenser lens 11, and makes the signal light emitted from the condenser lens 11 enter and emit as parallel light. The collimating lens 12 is positioned so that the optical axis of the collimating lens 11 coincides with the optical axis of the condensing lens 11 so that the signal light emitted from the condensing lens 11 is incident, and the collimating lens support portion (in FIG. 1). (Not shown). Specifically, the collimating lens 12 is preferably a lens having a convex surface on which signal light is incident from the condenser lens 11 and a flat surface on which parallel light is emitted.

  The optical fiber 13 allows the signal light made parallel by the collimating lens 12 to enter (via the fiber collimator 14) and transmit the signal light. The optical fiber 13 has an incident end for allowing signal light to enter and the other end connected to the fiber coupler 15. Specifically, it is preferable to use a single mode optical fiber having a core of about 10 μm from the viewpoint of transmission efficiency and the like.

  The fiber collimator 14 is connected to an incident end 13 a for allowing the signal light of the optical fiber 13 to enter. The fiber collimator 14 condenses the signal light emitted from the collimator lens 12 and makes it incident on the incident end of the optical fiber 13. As shown in FIG. 2, the fiber collimator 14 includes a lens 14a and an optical fiber fixing portion 14b. The lens 14a is an optical fiber lens that collects the signal light emitted from the collimator lens 12 as signal light incident on the incident end 13a of the optical fiber 13 and makes it incident on the incident end 13a. The lens 14a has a convex surface on the collimator lens 12 side and a side on the incident end 13a side of the optical fiber 13 so that the diameter of the signal light emitted from the collimator lens 12 can be reduced and incident on the incident end 13a of the optical fiber 13. It is preferable to use a flat one.

  The optical fiber fixing portion 14b fixes the incident end 13a of the optical fiber 13 and the lens 14a. The optical fiber fixing portion 14b is formed of a cylindrical member, and is provided in a state where the cylindrical member can substantially coincide with the optical axis of the reduction optical system. The optical fiber fixing portion 14b fixes the incident end 13a by inserting the incident end 13a of the optical fiber 13 from the end far from the reduction optical system. In addition, the lens 14a is positioned and fixed at the other end (the end closer to the reduction optical system) so that the optical axis thereof coincides with the optical axis of the incident end 13a. Yes. FIG. 2 is a diagram schematically showing the collimating lens 12, the optical fiber 13, the incident end 13a, and the fiber collimator 14.

  As shown by the arrows in FIG. 2, the incident end 13a of the optical fiber 13 and the fiber collimator 14 connected to the incident end 13a are rotatable in an optical fiber support (not shown in FIGS. 1 and 2). 2) is supported by the optical fiber fixing portion 14b. This rotation is performed to adjust the positions of the fiber collimator 14 and the incident end 13a of the optical fiber 13 so that the signal light emitted from the collimating lens 12 is appropriately incident. The rotation is performed in a state where the incident surface of the incident end 13 a and the incident surface of the lens 14 a of the fiber collimator 14 face the collimating lens 12. The incident end 13a, the fiber collimator 14 and the collimating lens 12 are provided in a state where the optical axis of the incident end 13a and the fiber collimator 14 and the optical axis of the collimating lens 12 can substantially coincide (state shown in FIG. 2). The rotation here is not necessarily a movement of 360 degrees, but within a range necessary for optical axis adjustment, for example within a range of several tens of degrees, along a circumference or a spherical surface with a predetermined axis or point as a rotation center. It also includes moving.

  The rotation center of the rotation is located closer to the collimator lens 12 than the incident end 13 a of the optical fiber 13. In the present embodiment, since the fiber collimator 14 is provided at the incident end 13a of the optical fiber 13, the center of rotation is located closer to the collimator lens 12 than the tip of the fiber collimator 14 on the collimator lens 12 side. Yes. More specifically, the vicinity 30 of the collimating lens 12 is preferable as shown in FIG. Specifically, the rotation mechanism is, for example, a gimbal type mechanism, that is, a plurality of axes passing through the vicinity 30 is used as a rotation axis, and the incident end 13a of the optical fiber 13 is relative to each of the rotation axes. This can be realized by using a mechanism that supports the optical fiber 13 in a rotatable state. The rotation mechanism will be described in detail later.

  Position control by rotation of the fiber collimator 14 and the incident end 13a of the optical fiber 13 is performed by driving a drive unit (not shown in FIGS. 1 and 2) that receives control from the CPU 17, as will be described later. It is preferable. However, the drive unit may be manually controlled, and the position control may be performed by a user operation.

  The fiber coupler 15 is a branching unit that branches a part of the signal light incident on the optical fiber 13 and outputs it to the light intensity monitor 16 and outputs the remaining part as a reception signal for wireless communication. The fiber coupler 15 and the light intensity monitor 16 are connected by an optical fiber 21. The signal light output from the fiber coupler 15 is input to the light intensity monitor 16 through the optical fiber 21. Further, another optical fiber 22 is connected to the fiber coupler 15, and a reception signal is output from the optical fiber 22. The output reception signal may be output after being converted into an electrical signal by a photodiode or the like, for example.

  The light intensity monitor 16 receives the signal light output from the fiber coupler 15 and detects the light intensity of the signal light. That is, the light intensity monitor 16 (and the fiber coupler 15) is signal light intensity detection means for detecting the intensity of the signal light incident on the optical fiber 13. Specifically, the detection of the light intensity is performed using, for example, a photodiode. The light intensity monitor 16 transmits the detected light intensity value of the signal light to the CPU 17.

  Based on the intensity value of the signal light detected by the light intensity monitor 16, the CPU 17 rotates the fiber collimator 14 and the incident end 13 a of the optical fiber 13 by controlling the drive unit (not shown in FIG. 1). This is the incident end position control means for controlling the respective positions. The rotation of the fiber collimator 14 and the incident end 13a of the optical fiber 13 is performed by transmitting a control signal from the CPU 17 to the drive unit. The control is performed so that the signal light is appropriately incident on the incident end 13 a of the optical fiber 13. For example, it is performed by rotating the signal light detected by the light intensity monitor 16 in a direction in which the intensity is increased.

  Subsequently, components such as the reduction optical system, the optical fiber 13, the optical fiber support unit, and the drive unit in the optical wireless communication apparatus 10 will be described in more detail. FIG. 3 is a side view of the above-described components arranged in the housing. As shown in FIG. 3, the condenser lens 11 is held by a lens holder 41 and is positioned and fixed.

  The collimating lens 12 is fixed by a collimating lens support portion 42. The collimating lens support portion 42 is positioned and fixed to the bottom surface of the housing of the optical wireless communication apparatus 10, and holds the collimating lens 12 by a member 42 a extending vertically from the bottom surface. The collimator lens support 42 is provided with position adjusting screws 42b, 42c, and 42d. The position of the collimating lens 12 can be finely adjusted in advance by using these position adjusting screws 42b, 42c, and 42d. The position adjustment screw 42b sets the position in the horizontal direction (direction perpendicular to the paper surface in FIG. 3), the position adjustment screw 42c sets the position in the vertical direction (up and down direction in FIG. 3), and the position adjustment screw 42d sets the position in the optical axis direction ( The position in the horizontal direction in FIG. 3 can be finely adjusted.

  The fiber collimator 14 is supported on the optical fiber fixing portion 14b by the optical fiber support portion 50 in a rotatable state. Since the fiber collimator 14 is supported in a rotatable state, the incident end 13a of the optical fiber 13 fixed to the fiber collimator 14 is also rotatable as described above. The optical fiber support unit 50 holds the fiber collimator 14 and rotates together with the fiber collimator 14, and the fixed unit that is positioned and fixed to the bottom surface of the housing of the optical wireless communication apparatus 10 and supports the movable unit 60. 70. The optical fiber support 50 holding the fiber collimator 14 can rotate about the vertical axis A1 and the horizontal axis A2 as rotation axes. In addition, as shown in FIG. 3, each rotating shaft A1, A2 passes the vicinity 30 of the collimating lens 12 used as the rotation center mentioned above. The rotation axes A1 and A2 are perpendicular to the optical axes of the reduction optical system, that is, the condensing lens 11 and the collimating lens 12. The rotation axes A1 and A2 are perpendicular to each other. These conditions concerning the rotation axes A1 and A2 are preferable for appropriately performing the optical axis adjustment. The collimating lens support portion 42 and the optical fiber support portion 50 are not in contact with each other.

  The fixing portion 70 is provided with a position adjusting screw 71 as in the collimating lens support portion 42, so that the position of the entire optical fiber support portion 50 in the optical axis direction can be finely adjusted. Further, a position adjusting screw may be provided so that the position can be finely adjusted in the horizontal direction and the vertical direction. In order to adjust the position by the rotation of the fiber collimator 14, the fixing unit 70 is provided with the actuators 72 and 73 as the driving unit described above. Further, a tension spring 74 having one end connected to the fixed portion 70 and the movable portion 60 is provided.

  The fixed part 70 has a plate-like member 70 a at a position facing the upper surface of the movable part 60. Further, plate-like members 70b are respectively provided at positions facing both side surfaces (in the horizontal direction). The plate-like member 70a on the upper surface of the movable portion 60 has a length up to a location where the collimating lens 12 is located, and supports the movable portion 60 so as to hang substantially above the collimating lens 12. . This support is made so that the movable portion 60 can rotate about the axis A1 in the vertical direction as a rotation axis.

  FIG. 4 shows the configuration of the movable part 60 of the optical fiber support part 50 in more detail. FIG. 4A is a diagram (a sectional view seen from above) showing a horizontal section passing through the central axis of the fiber collimator 14. FIG. 4B is a diagram (a sectional view seen from the side) showing a vertical section passing through the central axis of the fiber collimator 14. FIG. 4C is a front view of the optical fiber support 50 viewed from the condenser lens 11 side. As shown in FIG. 4, the movable unit 60 includes a vertical axis rotating unit 61, a horizontal axis rotating unit 62, and a drive control receiving unit 63. The vertical axis rotation unit 61 is connected to be suspended from the plate-like member 70a of the fixed unit 70 so that the vertical axis rotation unit 61 can rotate about the vertical axis A1 as a rotation axis.

  The horizontal axis rotation unit 62 is supported by the vertical axis rotation unit 61 at two points on the axis A2 so that the horizontal axis A2 passing through the vicinity of the collimator lens 12 can be rotated as a rotation axis. The horizontal axis rotating unit 62 fixes the fiber collimator 14. The fiber collimator 14 is fixed by, for example, a screw 62a as shown in FIG. The fiber collimator 14 can rotate about the axes A1 and A2 by a gimbal type mechanism such as the vertical axis rotating part 61 and the horizontal axis rotating part 62 in the movable part 60. The vertical axis rotating unit 61 and the horizontal axis rotating unit 62 are members having a shape sandwiching the fiber collimator 14 as shown in FIG. 4 so as not to block the signal light emitted from the collimating lens 12 and entering the fiber collimator 14. Is preferably used.

  Further, a drive control receiving portion 63 is fixed to the horizontal axis rotating portion 62. The drive control receiving portion 63 is constituted by a long member, the longitudinal direction is the optical axis direction, one end is at the position of the fiber collimator 14 in the optical axis direction, and the other end is the fixed portion 70. The plate-like member 70a is fixed so as to be positioned outside the end on the opposite side of the condenser lens 11. A tension spring 74 whose one end is connected to the fixed portion 70 is connected to the other end portion of the drive control receiving portion 63. A force in the upward direction and the depth direction in FIG. 3 is applied to the drive control receiving portion 63 by a tension spring 74. On the other hand, the drive control receiving portion 63 is supported by the actuator 72 from above in FIG. 3 and by the actuator 73 from the depth direction in FIG. Therefore, the position of the fiber collimator 14 can be determined based on the position where the drive control receiving portion 63 is supported by the actuators 72 and 73. The position where the drive control receiving portion 63 is supported by the actuators 72 and 73 is determined by a control signal from the CPU 17. In addition, it is preferable that the drive control receiving part 63 is comprised with the material which has the hardness which can fully transmit operation | movement of the actuators 72 and 73. FIG. For example, it is preferable to use electric actuators 72 and 73 that can be controlled by the CPU 17.

  Subsequently, the operation of the optical wireless communication apparatus 10 will be described. This operation is performed when the optical wireless communication apparatus 10 receives signal light as a wireless communication signal by emitting signal light as a wireless communication signal from the optical wireless communication apparatus of the communication partner.

  In the optical wireless communication device 10, the signal light projected by the optical wireless communication device of the communication partner is received by the condenser lens 11. The received signal light has its diameter reduced by the condenser lens 11 and is emitted to the collimating lens 12. Subsequently, the signal light enters the collimating lens 12 and is converted into parallel light and emitted. Subsequently, the signal light passes through the fiber collimator 14 and enters the optical fiber 13 from the incident end 13a. Part of the signal light incident on the optical fiber 13 is branched by the fiber coupler 15, and the light intensity is detected by the light intensity monitor 16. The remainder of the signal light is output from the optical wireless communication apparatus 10 as a reception signal for wireless communication through the optical fiber 22. The value of the light intensity detected by the light intensity monitor 16 is transmitted to the CPU 17. A control signal is transmitted from the CPU 17 to the actuators 72 and 73, and the position of the drive control receiving portion 63 is controlled by the actuators 72 and 73, so that the position adjustment is performed by the rotation of the fiber collimator 14 and the incident end 13a of the optical fiber 13. Is called.

  The position adjustment is performed so that the signal light incident on the fiber collimator 14 and the incident end 13a of the optical fiber 13 is appropriately incident. Specific examples of the position adjustment of the fiber collimator 14 and the incident end 13a of the optical fiber 13 will be described with reference to FIGS. FIG. 5A shows a state in which the optical axis of the collimating lens 12 and the optical axes of the fiber collimator 14 and the incident end 13a of the optical fiber 13 coincide with each other. In FIG. 5A, a thick solid line indicates a locus 81 derived by simulation of signal light incident at an incident angle of 0 degree with respect to the optical axis of the condenser lens 11. A thin solid line indicates a locus 82 derived by simulation of signal light incident at an incident angle of 0.2 degrees with respect to the optical axis of the condenser lens 11. FIG. 5B shows the incident point at the incident end 13a of the optical fiber 13 in the locus of each signal light.

  As shown in FIG. 5, in the state where the optical axis of the collimating lens 12 and the optical axis of the incident end 13a of the fiber collimator 14 and the optical fiber 13 coincide with each other, the signal light incident at an incident angle of 0 degrees is incident on the incident end 13a. Is incident with the center of the optical axis and the optical axis. On the other hand, the signal light incident at an incident angle of 0.2 degrees is incident with the end of the incident end 13a and the optical axis of the signal light deviated from the optical axis of the incident end 13a. When the signal light is incident as described above, the aberration of the optical system increases.

  FIG. 6A shows a state in which the positions of the fiber collimator 14 and the incident end 13a of the optical fiber 13 are adjusted so that signal light incident at an incident angle of 0.2 degrees is appropriately incident. In FIG. 6A as well, a thick solid line indicates a locus 81 derived by simulation of signal light incident at an incident angle of 0 degrees with respect to the optical axis of the condenser lens 11. A thin solid line indicates a locus 82 derived by simulation of signal light incident at an incident angle of 0.2 degrees with respect to the optical axis of the condenser lens 11. FIG. 6B shows the incident point at the incident end 13a of the optical fiber 13 in the locus of each signal light.

  As shown in FIG. 6, when the positions of the fiber collimator 14 and the incident end 13a of the optical fiber 13 are adjusted so that the signal light incident at an incident angle of 0.2 degrees is appropriately incident, the incident angle is 0. The signal light incident at .2 degrees is incident with the center of the incident end 13a and the optical axis. On the other hand, the signal light incident at an incident angle of 0 ° is incident with the end of the incident end 13a and the optical axis of the signal light deviated from the optical axis of the incident end 13a. When the signal light is incident as described above, the aberration of the optical system increases.

  As described above, in the optical wireless communication apparatus 10 according to the present embodiment, it is possible to perform position adjustment by rotation about the vicinity of the collimator lens 12 (near the parallel light exit surface in the reduction optical system). is there. Therefore, when the signal light is incident at an incident angle of 0 degrees, the position adjustment shown in FIG. 5A is performed. When the signal light is incident at an incident angle of 0.2 degrees, the position adjustment illustrated in FIG. Each can be done. Thus, according to the present embodiment, the optical axis of the signal light emitted from the collimator lens 12 as parallel light coincides with the optical axis of the incident end 13a of the optical fiber 13, and the signal light enters the incident end 13a. The corners can be appropriate. Further, since the center of rotation is located in the vicinity of the collimating lens 12, it is possible to easily adjust the position in a wide range. Therefore, the signal light can be appropriately incident on the incident end 13a of the optical fiber 13 even when the incident angle of the signal light incident on the condenser lens 11 has a width depending on conditions (for example, weather conditions). . Furthermore, the aberration of the optical system can be reduced by appropriately inputting the signal light in this way.

  Further, the position control of the optical wireless communication apparatus 10 does not control the position and orientation of the entire apparatus, but controls the position and orientation of only the incident end 13a of the optical fiber 13 and the fiber collimator 14. The tracking mechanism with respect to the incident direction of light can be miniaturized and the speed can be increased.

  Further, as in the present embodiment, the optical fiber support 50 that holds the incident end 13a of the optical fiber 13 and the fiber collimator 14 so as to be able to control the position is made to be a gimbal type mechanism. Thus, the rotatable mechanism can be easily configured as described above. However, any mechanism that can rotate as described above may be used, and a gimbal type mechanism is not necessarily required.

  Further, if the condensing optical system is configured to include the condensing lens 11 and the collimating lens 12 as in the present embodiment, a conventional technique can be applied to this point and the light can be easily collected. An optical optical system can be configured.

  Further, if the fiber collimator 14 is connected to the incident end 13a of the optical fiber 13 as in the present embodiment, even when the optical fiber 13 having a small core diameter such as a single mode fiber is used, The signal light can be reliably incident on the optical fiber 13. Moreover, since the optical fiber support part 50 in the optical wireless communication apparatus 10 may support the fiber collimator 14 (the optical fiber fixing part 14b) directly, it is possible to support the optical fiber more reliably and easily. .

  Further, as in this embodiment, if the intensity of the received signal light is detected and position control is performed based on this intensity, automatic and more accurate position control becomes possible. However, this configuration is not necessarily required, and the position may be adjusted by operating the actuator by the user.

It is a figure which shows the structure of the optical wireless communication apparatus which concerns on embodiment of this invention. It is a figure which shows the positional relationship of a collimating lens, an optical fiber, and a fiber collimator. It is a side view of the optical system of an optical wireless communication apparatus. It is a figure which shows the structure of the movable part of an optical fiber support part. It is a figure which shows the positional relationship of a collimating lens, an optical fiber, and a fiber collimator, and the example of the locus | trajectory of the incident signal light. It is a figure which shows another example of the positional relationship of a collimating lens, an optical fiber, and a fiber collimator, and the locus | trajectory of the incident signal light.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Optical wireless communication apparatus, 11 ... Condensing lens, 12 ... Collimating lens, 13, 21, 22 ... Optical fiber, 13a ... Incident end, 14 ... Fiber collimator, 14a ... Optical fiber lens, 14b ... Optical fiber fixing | fixed part 15 ... fiber coupler, 16 ... light intensity monitor, 17 ... CPU, 41 ... lens holder, 42 ... collimator lens support, 50 ... optical fiber support, 60 ... movable part, 61 ... vertical axis rotation part, 62 ... horizontal Shaft rotating part, 63 ... drive control receiving part, 70 ... fixing part, 72, 73 ... actuator, 74 ... tension spring.

Claims (6)

A reduction optical system that receives signal light that has arrived as a wireless communication signal, reduces the diameter of the signal light, and emits it as parallel light; and
An optical fiber having an incident end on which the signal light emitted by the reduction optical system is incident;
An optical fiber support that supports the optical fiber in a state where the incident end is rotatable, with the vicinity of the parallel light exit surface in the reduction optical system as a rotation center;
An optical wireless communication apparatus comprising: The reduction optical system includes:
A condenser lens that receives the signal light that has arrived as the wireless communication signal and emits the signal light so that the diameter of the signal light is reduced;
A collimating lens that makes the signal light emitted from the condenser lens incident and collimated, and emits the emitted light from the reduction optical system;
The optical wireless communication apparatus according to claim 1, comprising: A collimating lens that receives signal light and emits it as parallel light;
A collimating lens support for supporting the collimating lens;
An optical fiber having an incident end through which signal light is incident, and being provided in a state where the optical axis of the collimating lens and the optical axis of the incident end can substantially coincide with each other;
An optical fiber support for supporting the optical fiber in a state where the incident end is rotatable around the collimator lens support near the rotation center;
An optical wireless communication apparatus comprising:   The optical fiber support unit supports the optical fiber in a state in which the incident end is rotatable with respect to the rotation axis with an axis passing through the vicinity as a rotation axis. An optical wireless communication apparatus according to claim 1. An optical fiber lens that collects the signal light incident on the incident end of the optical fiber and enters the incident end; and
An optical fiber fixing portion that positions the optical fiber lens so that its optical axis coincides with the optical axis of the incident end, and fixes the lens to the incident end; and
The optical fiber support portion supports the optical fiber in a state where the incident end is rotatable by supporting the optical fiber fixing portion in a rotatable state.
The optical wireless communication apparatus according to any one of claims 1 to 4, wherein: Signal light intensity detection means for detecting the intensity of the signal light incident on the optical fiber;
An incident end position control means for controlling the position of the incident end of the optical fiber by rotating the incident end based on the intensity of the signal light detected by the signal light intensity detecting means;
The optical wireless communication apparatus according to any one of claims 1 to 5, further comprising:

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