JP2006217289A - Optical radio transmitting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical radio transmitting device which enables alignment of an optical axis to be confirmed by simple structure and simple operation. <P>SOLUTION: The optical radio transmitting device comprises: an optical transmitter 1 provided with an optical signal transmission part, a visible laser beam emitting part for alignment of the optical axis, and a mechanism 21 capable of horizontally and vertically rotating the optical signal transmission part and the visible laser beam emitting part in an integrated state; and an optical receiver 2 provided with an optical signal reception part, a visible laser beam emitting part, and a mechanism 21 capable of horizontally and vertically rotating the optical signal reception part and the visible laser beam emitting part in an integrated state. The optical signal transmission part and the visible laser beam emitting part of the optical transmitter are arranged so as to be opposed to the optical signal reception part and the visible laser beam emitting part of the optical receiver respectively. Each of the optical transmitter and the optical receiver is provided with an infrared light receiving part for turning on/off visible laser emission by the visible laser beam emitting part based on reception of an infrared signal. The infrared light receiving part provided at the optical receiver is provided facing a direction different from a direction which the optical signal reception part faces. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an optical wireless transmission apparatus that enables optical axis alignment with a simple structure and allows easy confirmation of optical axis alignment when communication is poor.

  Conventionally, there is an optical wireless transmission technology for performing spatial transmission of information using light. Infrared light is generally used for this optical wireless transmission, and a semiconductor light emitting element such as a light emitting diode or a laser diode is used as the light emitting element. In such optical wireless transmission, when a sufficient distance between transmission and reception is desired, it is necessary to sharply squeeze the light beam emitted from the transmission device so that a sufficient amount of light is incident on the reception device side. Further, it is necessary to narrow the angle of the light receiving range so that the light receiving side also has an advantageous effect on the removal of disturbance light and the reception sensitivity. In such a state, it is necessary to align the optical axes of the transmitter and receiver. However, the optical axis is aligned because a highly directional light beam or invisible infrared light is used as the light beam. Is a very cumbersome task.

  In view of this, an optical wireless transmission apparatus that can easily align the optical axis has been proposed. For example, an optical wireless transmission device that installs a sighting device on the transmitter and the operator looks at the sighting device and aligns the optical axis, or a measuring device for detecting the received light level on the receiving device side, and two people Some optical wireless transmission devices perform axis alignment. There is also a type in which a light source for adjusting the optical axis is provided on the light receiver side, the reception level information of the transmission light from the transmitter is turned back, and the optical axis is adjusted on the transmitter side according to the reception level. As a method of using a light source for adjusting the optical axis, there is a method of performing correction programmatically.

However, these methods have a problem in that the cost of the apparatus is high because it is a manual method or it is necessary to incorporate various control means in the apparatus. Therefore, as a method for realizing inexpensive optical axis alignment, a wireless device that performs optical axis alignment according to the received light level of the laser light with a simple structure using laser light for alignment has been proposed (for example, the following patents) Reference 1).
JP-A-5-175907

  However, with regard to optical axis alignment, there is a possibility that the optical axis once aligned may shift due to natural phenomena such as changes over time or strong winds, and in such a case, it is necessary to check whether the optical axis is aligned. become. However, in the conventional optical wireless optical axis alignment method with a simple structure, the work load for optical axis confirmation may be large.

  The method proposed in Patent Document 1 described above is a simple structure using a laser beam for alignment, and optical axis alignment is performed according to the light reception level of the laser light. However, the optical axis alignment is automatically performed by reading the light reception level. Since the mechanism that performs the operation requires a microcomputer and an actuator, it is not suitable for an inexpensive device. The method of reading the received light level by some method and applying force from the outside is considered to be suitable for constructing the device at low cost.However, when the received light level display is provided on the main body, the visibility of the display unit may be increased depending on the installation location. It is difficult to secure and it is not possible to obtain information on how far it is off. Although it is possible to obtain information on the light reception level via a network, in many cases it is necessary to operate a computer to obtain the information, and it is difficult to say that it is a simple method that anyone can operate. When a dedicated monitoring terminal is used without using a computer, the cost increases and it cannot be said that the structure is inexpensive.

  In addition, when laser light is used for optical axis alignment, emission control is also an issue. If laser light is always emitted, the cost burden is large in terms of power consumption and ensuring the reliability of the laser light source. If the laser light is turned on / off only when necessary, a method of providing a switch in the main body can be considered. In that case, the workability is good if it is turned on / off as necessary at the installation position during installation work, but in order to check whether the optical axis is correct when communication failure occurs after installation, check again at the installation site. Work is necessary, especially in high places. Although a method of detecting a communication error and automatically emitting light can be considered, even in a place where people come and go, even if it is a specification that emits a laser beam at a safe level, various factors overlap and it is a dangerous situation It is the most desirable form to emit light for a required time at a required place.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide an optical wireless transmission apparatus capable of realizing confirmation of optical axis alignment at the time of communication failure with a simple structure and simple operation.

  As means for achieving the above object, an optical wireless transmission apparatus according to the present invention comprises an optical transmission means for transmitting an optical signal, a visible light emitting means for emitting an optical axis alignment visible laser light, and the optical transmission means. And an optical transmitter having a mechanism capable of adjusting the horizontal direction and the vertical direction integrally with the visible light emitting means, an optical receiving means for receiving the optical signal, and emitting visible laser light for optical axis alignment In the optical wireless transmission device comprising: a visible light emitting means; and an optical receiver comprising a mechanism capable of adjusting the optical receiving means and the visible light emitting means in a horizontal direction and a vertical direction in an integrated state. When the transmitter and the optical receiver are opposed to each other, the optical transmission unit and the visible light emitting unit of the optical transmitter are opposed to the optical reception unit and the visible light emitting unit of the optical receiver, respectively. And placed in front Both the optical transmitter and the optical receiver are provided with infrared light receiving means for turning on / off visible laser light emission of the visible light emitting means based on reception of infrared light signals, respectively, and at least the light The infrared light receiving means provided in the receiver is provided in a direction different from the direction in which the optical receiving means is directed.

  An optical wireless transmission apparatus according to the present invention includes an optical transmission unit that transmits an optical signal, an optical reception unit that receives an optical signal, a visible light emitting unit that emits visible laser light for optical axis alignment, and the optical In an optical wireless transmission apparatus in which a pair of optical transceivers including a transmission unit, a mechanism capable of adjusting the optical receiving unit and the visible light emitting unit in an integrated state in a horizontal direction and a vertical direction are arranged to face each other, The optical transmitting means and the optical receiving means are arranged along a horizontal direction, and the visible light emitting means is disposed at equidistant positions with respect to the optical transmitting means and the optical receiving means. The infrared light receiving means for turning on / off the visible laser light emission of the visible light emitting means based on reception of the infrared light signal in each of the pair of optical transceivers, Red Light receiving means, characterized in that provided in different directions to the light receiving direction of said optical receiving means.

  According to the present invention, by appropriately arranging the optical transmission means, the optical reception means, and the visible light emitting means, the optical axis alignment of the optical signal transmission / reception can be performed only by applying the visible laser light to the opposing visible laser light emitting section. By providing the infrared light receiving means in a direction different from the direction in which the optical signal is transmitted and received, visible laser light emission can be turned on / off without being affected by the optical signal by the infrared light. it can. Therefore, it is possible to operate such that visible laser light emission is normally turned off to prevent excessive power consumption, and is turned on only when necessary for optical axis confirmation, and the optical axis alignment state is visually confirmed. it can.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a block diagram showing a configuration of an optical wireless transmission apparatus for one-way communication according to an embodiment of the present invention for realizing an optical axis alignment method. As shown in FIG. 1, the optical wireless transmission apparatus according to the present embodiment includes an optical transmitter 1 and an optical receiver 2, and radiates an optical signal 10 from the optical transmitter 1 to the optical receiver 2 to transmit information. Is done. In order to align the optical axes, the visible laser light 11 emitted from the optical transmitter 1 and the visible laser light 12 emitted from the optical receiver 2 are applied to the other visible laser light source, whereby the optical signal emission optical axis and the optical signal reception are obtained. Align the optical axis. Various kinds of information can be transmitted by the optical signal 10, but the purpose of this embodiment is to transmit video and audio information.

  Here, as will be described in detail later, the optical transmitter 1 includes an optical signal transmitter that transmits an optical signal and a visible laser beam emitter that emits an optical axis alignment visible laser beam 11. A mechanism 21 capable of rotating in a horizontal direction and a vertical direction in a state where the signal transmission unit and the visible laser light emitting unit are integrated is provided. Similarly, the optical receiver 2 includes an optical signal receiving unit that receives an optical signal and a visible laser light emitting unit, and the optical signal receiving unit and the visible laser light emitting unit are integrated in the horizontal direction. A mechanism 21 capable of rotating in the vertical direction is provided.

  When the optical transmitter 1 and the optical receiver 2 are opposed to each other, the optical signal transmission unit and the visible laser light emission unit of the optical transmitter 1 are replaced with the optical signal reception unit and the visible laser beam of the optical receiver 2. On and off the visible laser light emission of the visible laser light emitting unit based on the reception of the infrared light signal in both the optical transmitter 1 and the optical receiver 2 while being arranged to face the light emitting unit respectively. Infrared light receiving units that perform the above-described configuration, and at least the infrared light receiving unit provided in the optical receiver 2 is provided in a direction different from the direction in which the optical signal receiving unit is directed. Thus, an optical wireless transmission device for one-way communication is configured.

  FIG. 2 is a diagram illustrating an installation example of the optical wireless transmission device illustrated in FIG. 1. Note that FIG. 2 shows a form in which bidirectional optical wireless transmission is realized by a pair of optical transceivers 20 including the optical transmitter 1 and the optical receiver 2. The pair of optical transceivers 20 is installed using a pole or the like at a height that does not block the light beam of an optical signal in a place where people are coming and going.

  FIG. 3 is a view of the optical transceiver 20 of the optical wireless transmission apparatus according to the present invention as seen obliquely from below. As shown in FIG. 3, the optical transceiver 20 includes an optical signal receiving unit 30 that receives an optical signal, a visible laser light emitting unit 40 that emits visible laser light for optical axis alignment, and an optical signal transmitting unit that transmits an optical signal. 50, which are arranged in a straight line on the left and right, and a visible laser light emitting unit at an intermediate position (a position where A = B in FIG. 3) between the optical signal receiving unit 30 and the optical signal transmitting unit 50 40 is provided. The light emitting optical axis 51 of the optical signal transmitting unit, the optical axis 41 of the visible laser beam, and the light receiving optical axis 31 of the optical signal receiving unit are adjusted in advance so as to be parallel to each other and to face the same direction. Furthermore, the optical signal receiving unit 30, the visible laser light emitting unit 40, and the optical signal transmitting unit 50 are provided with a rotation mechanism 21 that can rotate in the horizontal direction and the vertical direction in an integrated state. With such a structure, the optical transmitter / receiver 20 can be easily aligned with the optical axis for transmitting / receiving an optical signal that is not visible light by simply facing the visible laser light to the other visible laser light emitting unit 40 while facing it. An infrared light receiving unit 60 that turns on / off the visible laser light emission of the visible laser light emitting unit 40 based on the reception of the infrared light signal is provided in a direction different from the light receiving direction of the optical signal.

  FIG. 4 is a diagram showing the internal structure of the optical transceiver 20 in the present invention. The optical signal receiving unit 30 includes an optical system including a lens, a PD (photodiode), and a horizontal / vertical adjustment mechanism. The optical system includes a wavelength selection filter that blocks disturbance light in addition to the lens. The visible laser light emitting unit 40 includes an optical unit including a lens, a visible laser light emitting element, a laser driving circuit, and a horizontal / vertical adjustment mechanism, and a laser having a wavelength of 635 nm and a small emission angle is used. The optical signal transmission unit 50 includes an optical system including a lens, an LD (laser diode), and an adjustment mechanism in the horizontal and vertical directions, and obtains a desired radiation angle by adjusting the distance between the optical system and the LD. Each of the above three elements is provided with a horizontal and vertical adjustment mechanism. However, since it is only necessary that three optical axes are finally aligned, one optical axis may be fixed and the other two optical axes may be aligned. It is feasible.

  FIG. 5 is a diagram illustrating a state in which the optical axes of the pair of optical transceivers 20 arranged to face each other are aligned. By making the optical signal transmitting unit 50 and the optical signal receiving unit 30 face each other and aligning the visible laser beam spot of the visible laser beam emitting unit 40 with the light source of the other visible laser beam (by matching the optical axis 41) The light receiving and emitting optical axes 31 and 51 of the other two optical signals are aligned. Reference numeral 32 denotes the range of the light reception directivity angle of the optical signal receiver 30, 42 denotes the range of the visible laser light emission angle of the visible laser light emitter 40, and 52 denotes the range of the light emission angle of the optical signal transmitter 50. ing.

  Specifically, an LD that emits infrared light is used for the optical signal transmission unit 50, and the radiation angle is adjusted to 2 degrees over the entire width by an optical system (not shown). Although the energy density can be increased as the radiation angle is narrowed, in this embodiment, the radiation angle is determined assuming a communication distance of about several tens of meters. A PD is used for the optical signal receiving unit 30, and the light receiving directivity angle of the PD is set to 1.5 degrees in the entire width by an optical system (not shown). This indicates an optically effective range of light having a predetermined intensity for both the radiation angle and the directivity angle. According to the 2 degree radiation angle of the transmitted light, it becomes a spot with a diameter of about 35 cm after 10 m, and a spot with a diameter of about 1 m after 30 m. Similarly, according to the reception directivity angle of 1.5 degrees, a spot with a diameter of about 26 cm is formed 10 m ahead, and a spot with a diameter of about 80 cm is formed 30 m ahead. In optical wireless, the optical axis for transmission and reception of optical signals is the state where the light receiving element is captured at the spot of the transmission light radiation angle and the other transmitting light emitting element is captured at the spot of the light reception directivity angle. . These can be variously combined depending on the effective diameter of the lens and the performance of the light emitting element / light receiving element, but an optimal combination is selected depending on cost, ease of optical axis alignment, and transmission distance.

  FIG. 6 is a diagram showing a state where the optical axes 31, 41 and 51 are not aligned with respect to FIG. 5 which shows a state where the optical axes 31, 41 and 51 are aligned. The optical axes 31, 41, 51 of the optical transceiver 20 on the left side of the drawing grasp the corresponding parts of the optical transceiver 20 on the right side within the optically effective range, but the right optical transceiver 20 is on the other side. Since they are not facing each other, the corresponding parts of the left optical transceiver 20 are not captured within the optically effective range, so that the optical axes are not aligned. Since the optical signal is not visible light, it cannot be seen with the naked eye, but in such a state, since the visible laser beam indicates a position shifted, it is visually understood that the optical axis is shifted.

  FIG. 7 is a diagram for explaining the state of optical axis alignment in the present embodiment. In the optical transmitter / receiver 20, the optical signal transmitter 50, the optical signal receiver 30, and the visible laser light emitter 40 are integrated, and a mechanism 21 that can rotate in the horizontal direction and the vertical direction is provided. The optical axis is aligned with the visible laser light source of the transceiver 20. Normally, it is installed at a height that does not affect the passage of people or vehicles so that the light rays of the optical signal are not blocked. When the installation position is high, the optical transceiver 20 is installed and the optical axis is aligned using an aerial work vehicle as shown in FIG.

  The optical axis adjustment at the time of initial installation also requires the installation of the optical transceiver 20 and is less affected by workability even when working at a high place. When checking the optical axis in the case of communication failure, it is burdensome to involve work at a high place.

  As shown in FIG. 3, the optical transmitter / receiver 20 of the present invention is provided with an infrared light receiving unit 60 on the lower surface. Therefore, as shown in FIG. 8, a remote controller 61 as an infrared light emitting terminal from the ground is provided. If the infrared light signal 62 is sent by the above, the light emission state of the visible laser light emitting unit 40 can be switched. In addition, since the infrared light receiving unit 60 faces in a direction different from the direction in which the optical signal is received, the influence of the optical signal can be reduced. Furthermore, since the infrared light receiving unit 60 is provided on the bottom surface side that is optimal for remote control operation from a low position, the infrared light signal 62 of remote control operation from the ground side can be received efficiently.

  FIG. 9 is a block diagram showing a process of processing the infrared light signal 62 from the remote controller 61 received by the infrared light receiving unit 60 provided on the bottom surface of the optical transceiver 20 of the optical wireless transmission apparatus of the present invention. . As shown in FIG. 9, the infrared light signal 62 from the remote controller 61 received by the infrared light receiving unit 60 is transmitted to the control unit (microcomputer unit) 64 through the signal detection unit / amplifier circuit 63, and the control unit 64 Visible laser light emission by the visible light emitting element 40B is turned on / off via the light emitting element drive circuit 40A of the visible laser light emitting unit 40, and visible laser light is transmitted through the optical system 40C.

  Therefore, according to the said embodiment, the visible laser light emission part 40 of the other party which opposes a visible laser beam by arrange | positioning the optical signal transmission part 50, the optical signal receiving part 30, and the visible laser light emission part 40 appropriately. The optical axis of the optical signal transmission / reception can be adjusted simply by touching the optical signal, and by providing the infrared light receiving unit 60 in a direction different from the direction in which the optical signal is transmitted / received, the optical signal is not affected by the infrared light. Visible laser light emission can be turned on / off from a remote location under the control of the remote controller 61. Therefore, it is possible to operate such that visible laser light emission is normally turned off to prevent excessive power consumption, and is turned on only when necessary for optical axis confirmation, and the optical axis alignment state is visually confirmed. it can.

It is a block diagram which shows the structure of the optical wireless transmission apparatus of the one-way communication which concerns on embodiment of this invention for implement | achieving the optical axis alignment method. It is a figure which shows the example of installation of the optical wireless transmission apparatus shown in FIG. 1, and is a figure which shows the form which implement | achieves bidirectional optical wireless transmission with a pair of optical transmitter / receiver provided with the structure of an optical transmitter and an optical receiver. . It is the schematic which looked at the optical transmitter-receiver used for the optical wireless transmission apparatus of this invention from diagonally downward. It is a figure which shows the internal structure of the optical transmitter-receiver used for the optical wireless transmission apparatus of this invention. It is a figure which shows the structure of each optical part of the optical transmitter / receiver used for the optical wireless transmission apparatus of this invention, and is a figure which shows the state with which the optical axis of a pair of optical transmitter / receiver arrange | positioned so as to oppose was suitable. It is a figure which shows the state from which the optical axis of the optical transmitter-receiver used for the optical wireless transmission apparatus of this invention is not correct. It is a figure of the operation | work at the time of installing an optical wireless transmission apparatus in a high place, or a figure showing the mode of the operation | work in the case of the apparatus which cannot control the optical axis confirmation means from the outside. It is a figure which shows a mode that the optical axis confirmation of the optical transmitter / receiver used for the optical wireless transmission apparatus of this invention is performed. It is a block diagram at the time of turning on / off the visible laser light emission of the optical transmitter-receiver used for the optical wireless transmission apparatus of this invention by an infrared-light signal.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Optical transmitter 2 Optical receiver 10 Optical signal which optical transmitter emits 11 Visible laser beam which optical transmitter emits 12 Visible laser beam which optical receiver emits 20 Optical transmitter / receiver 21 Horizontal / vertical rotation mechanism 30 Optical signal receiver 31 Light Light receiving optical axis of signal receiving unit 32 Light receiving directivity angle range of optical signal receiving unit 40 Visible laser light emitting unit 41 Optical axis of visible laser light 42 Radiation angle range of visible laser light 43 Visible when optical axis is shifted Optical axis of laser light 50 Optical signal transmission unit 51 Optical emission axis of optical signal transmission unit 52 Range of emission radiation angle of optical signal transmission unit 60 Infrared light receiving unit 61 Remote control (infrared light emitting terminal)
62 Infrared light signal

Claims (2)

Optical transmission means that transmits optical signals, visible light emission means that emits visible laser light for optical axis alignment, and the optical transmission means and visible light emission means can be adjusted in the horizontal and vertical directions in an integrated state. An optical transmitter having a mechanism,
An optical receiving means for receiving the optical signal, a visible light emitting means for emitting an optical axis alignment visible laser beam, and the optical receiving means and the visible light emitting means are adjusted in a horizontal direction and a vertical direction in an integrated state. In an optical wireless transmission device comprising an optical receiver having a possible mechanism,
When the optical transmitter and the optical receiver are opposed to each other, the optical transmission unit and the visible light emitting unit of the optical transmitter are opposed to the optical reception unit and the visible light emitting unit of the optical receiver, respectively. And arrange to
Both the optical transmitter and the optical receiver each include infrared light receiving means for turning on / off visible laser light emission of the visible light emitting means based on reception of an infrared light signal, An optical wireless transmission device, wherein an infrared light receiving means provided in an optical receiver is provided in a direction different from a direction in which the optical receiving means is directed. Optical transmitting means for transmitting optical signals, optical receiving means for receiving optical signals, visible light emitting means for emitting visible laser light for optical axis alignment, optical transmitting means, optical receiving means, and visible light emitting In an optical wireless transmission apparatus in which a pair of optical transceivers including a mechanism that can be adjusted in a horizontal direction and a vertical direction in an integrated state is disposed so as to face each other
The optical transmitting means and the optical receiving means are arranged along a horizontal direction, and the visible light emitting means is disposed at equidistant positions with respect to the optical transmitting means and the optical receiving means. As well as arrange
Each of the pair of optical transceivers includes infrared light receiving means for turning on / off visible laser light emission of the visible light emitting means based on reception of an infrared light signal, and the infrared light receiving means, An optical wireless transmission device provided in a direction different from a light receiving direction of the optical receiving means.

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