JPH1198082A - Optical communication device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical communication device which improves light receiving power and also improves an S/N of a receiving signal. SOLUTION: This optical communicating device which has a quarter photodetector 70 in a light receiving part performs shift control of a light receiving part and a light emitting part so that a light spot 71 which is formed by guide light from the opposite optical transmitter-receiver may be formed in the center of the photodetector 70. A correction table is referred to with position information at the point of time to seek correction quantity, the light receiving and emitting parts are further performed shift control only as much as the correction quantity, and a light spot 72 due to the guide light from the opposite optical transmitter-receiver is formed in the center of one divided light receiving area 75 for communication that is preliminarily defined in the photodetector 70.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical communication device,
In particular, the present invention relates to an optical communication device that is connected to a portable terminal and enables the terminal to communicate with a partner terminal by an optical signal.

[0002]

2. Description of the Related Art In recent years, a LAN (local area network) for communicating between terminals such as personal computers, servers, and workstations, which are distributed and installed in relatively small areas such as in the same site or building. Are rapidly spreading. In such a LAN, the terminals as components are loosely coupled to each other so that they can operate independently. Each terminal can be moved for portable use, but if all of the terminals are wired, it is inconvenient to use. A LAN using an optical transmission line as a unit is known.

In a LAN using this optical transmission line, for example, as shown in FIG. 9, terminals 11 and 12 are, for example, optical transceivers 13a, 13b, 13a and 13b fixed to the ceiling of a building.
13c. Further, the optical transceivers 13a, 13b, 13c are connected to transceivers 14a, 14b, 14c fixed corresponding to the ceiling, respectively. Transceivers 14a, 14b and 14c
Are connected to a server or the like (not shown) via the Ethernet line 15.

The terminal 11 comprises an information processing device 11a such as a personal computer or a printer, and an optical communication device 11b connected to the information processing device 11a by a cable. Similarly, the terminal 12 includes an information processing device 12a and an optical communication device 12b connected thereto by a cable. Each of the optical transmitting / receiving devices 13a to 13c constantly emits a guide light, and when receiving transmission light from the optical communication devices 11b and 12b, optical communication with the optical communication device is enabled. .

The optical communication devices 11b and 12b are controlled by information processing devices 11a and 12a, whereby the information processing devices 11a and 12a are connected to the optical communication devices 11b and 12b connected to the optical communication devices 11b and 12b. Communication is performed between the nearest one of the transmitting and receiving devices 13a, 13b, and 13c, the transceiver connected to the optical transmitting and receiving device, and the partner terminal (not shown) via the Ethernet line 15. It is possible.

In the LAN having such a system configuration, the conventional optical communication devices 11b and 12b have optical transmission / reception devices 13a to 13c which always emit guide light.
Scanning the optical transmitting and receiving unit in a certain range, detecting the maximum position of the optical receiving level within the range, and moving the optical transmitting and receiving unit to the position in order to search for the nearest optical transmitting and receiving device. Thus, the optical axis between the optical transceiver and the optical transceiver is aligned.

However, the above-mentioned conventional optical communication apparatus has to measure the light reception level (light reception level) at all points within a preset scanning range, so that it takes a long time to adjust the optical axis. There is. Further, since the conventional optical communication device has a configuration in which the light receiving section has a single light receiving area, it is impossible to detect the moving direction even if it is known that the light receiving section has been moved, so that the following operation is impossible.

In view of the above, the present inventor has filed a patent application filed on the same date as the present patent application (reference number 40900003), using a four-divided photodetector as a light receiving element of an optical transmitting and receiving unit, and determining the light receiving spot position as x from the light receiving signal level. By detecting which side in the direction or the y direction the light spot is located substantially at the center position on the four-segment photodetector, it is possible to adjust the optical axis with the opponent optical transmission / reception apparatus as compared with the related art. We have proposed an optical communication device in which the required time can be greatly reduced and the tracking operation can be performed.

[0009]

However, when the above-mentioned four-divided photodetector is used as a light receiving element, the optical axis is adjusted to a position where the light receiving levels of the four light detecting portions (divided light receiving areas) are equal. After that, a reception signal is obtained based on the output light reception signal of one predetermined light detection unit (divided light reception area) or received by adding all the light reception signals of the four light detection units (divided light reception area). Since the signal is obtained, the received light power is reduced to 1/4 in the former configuration.
In the latter configuration, the signal-to-noise ratio (S /
N) and the communication distance may be limited to a relatively short value.

[0010] The present invention has been made in view of the above points,
It is an object of the present invention to provide an optical communication device capable of improving light receiving power.

Further, another object of the present invention is to provide a receiving signal
An object of the present invention is to provide an optical communication device capable of improving / N.

[0012]

According to the present invention, in order to achieve the above-mentioned object, an optical scanning moving a light receiving section and a light emitting section is performed by the light receiving section in order to detect the guide light radiated from the optical transceiver. A light that performs while monitoring the received light signal, performs optical axis alignment between the light receiving unit and the light emitting unit and the optical transmitting and receiving device after detecting the guide light, and then performs optical communication with the optical transmitting and receiving device via the light receiving unit and the light emitting unit. In a communication device, a split photodetector used as a light receiving unit and having a light receiving area divided into three or more, a light receiving level detecting circuit for detecting each output light receiving signal level of the split light receiving area of the split photodetector, and Rotating means for integrally controlling the positions of the light receiving section and the light emitting section based on an external drive signal; and light on a split photodetector based on the received light level detection signal output from the received light level detection circuit. Spot Calculating means for calculating the level deviation in both the x and y directions indicating the deviation of the position from the center position of the divided photodetector, and based on the level deviation calculated by the calculating means, the absolute value of the level deviation is preset. A first driving unit for supplying a driving signal to the rotating unit so as to be smaller than the threshold value, and a divided photodetector based on positional information of the light receiving unit and the light emitting unit after the driving by the first driving unit is completed. A correction amount for setting the optical axis at the center of one of the predetermined divided communication light receiving areas is obtained, a drive signal corresponding to the correction amount is generated and supplied to the rotating means, and the light receiving unit and the light emitting unit And a second driving means for correcting the position.

In the present invention, after the light receiving section and the light emitting section are moved to a position where the light receiving levels of the respective divided light receiving areas can be obtained substantially equal by the first driving means, the position information of the light receiving section and the light emitting section at that position is added. Based on this, a correction amount for setting an optical axis at the center of one of the predetermined divided light receiving areas for communication among the divided photodetectors is obtained, and a drive signal corresponding to the correction amount is generated and supplied to the rotating means. Since the positions of the light receiving unit and the light emitting unit are corrected by using the optical axis, it is possible to align the optical axis with at least the center of at least one predetermined divided light receiving area for communication.

A first straight line connecting the center point of one predetermined divided light receiving area for communication and the center point of the light emitting element constituting the light emitting section is parallel to the first straight line. In addition, by arranging an interval between the split photodetector and a second straight line passing through the center of the split photodetector, the optical axis is aligned with the center of one communication divided light receiving area and the light axis of the light emitting section at the same time. Can also.

[0015]

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of an optical communication apparatus according to the present invention. In this embodiment, the LAN optical communication devices 11b and 12b having the system configuration shown in FIG.
It is a device used as. In FIG. 1, a central processing unit (CPU) 20 includes an A / D conversion unit 21 and a storage unit 2.
2 for controlling each part of the apparatus and supervising the operation of the entire apparatus. At the time of optical axis alignment performed prior to communication, the CPU 20 starts a processing operation described later by pressing the search switch (SW) 32.

The light emitting section 23 operates under the control of the CPU 20, and operates as a large-scale semiconductor integrated circuit (LSI) 25 for optical modulation and demodulation.
The optical signal is subjected to electro-optical conversion of the encoded transmission signal from the optical disc, and an optical signal whose light intensity is modulated by the transmission signal is output. The light receiving unit 24 converts the received light into a received signal that is an electric signal,
The received signal is supplied to an optical modulation / demodulation LSI 25 for demodulation, and is supplied to a light reception level detection circuit 26 to detect a light reception level.

The light emitting section 23 and the light receiving section 24 have a CP
In response to a drive signal input from U20 via a motor driver 27, the respective optical axis positions are controlled to move in the pan direction and the tilt direction by a pan direction motor 28 and a tilt direction motor 29 which are driven independently of each other. . The pan direction limit SW 30 is a switch that is turned on at the limit point of the scanning range of the optical axis of the light emitting unit 23 and the light receiving unit 24 in the pan direction. Similarly, the tilt direction limit SW 31 is
The switch is turned on at the limit of the scanning range of the light emitting unit 23 and the light receiving unit 24 in the tilt direction of the optical axis.

The CPU 20 and the optical modulation / demodulation LSI 25 are 10BAS, which is an example of LAN transmission line specifications standardized by 802.3 of the Institute of Electrical and Electronics Engineers (IEEE) of the United States.
It is connected to an information processing device (not shown) such as a personal computer (11a or 12a in the example of FIG. 9) via a driver 33 and a jack 34 based on the E-T with a twisted pair cable.

In this way, during communication after optical axis alignment, which will be described later, transmission data from the information processing device is supplied to the optical modulation / demodulation LSI 25 via the jack 34 and the driver 33, modulated, and then transmitted to the light emitting unit. The signal is converted into an optical signal by 23 and transmitted. On the other hand, the transmission data from the partner terminal is the optical transmission / reception device (13a to 13c in the example of FIG. 9).
After being converted into an optical signal and received by the light receiving unit 24,
The signal is demodulated by the optical modulation / demodulation LSI 25 and further transmitted to the information processing device through the driver 33 and the jack 34.

The mechanism itself of the optical communication apparatus according to the present embodiment having such a block configuration is disclosed by the present applicant in Japanese Patent Application No. 9-784.
No. 67 (Title of Invention "Optical Transceiver")
The optical communication device shown in the plan view of FIG. 2 can be used as it is. In FIG. 2, the center point of the transmitting lens 41 is provided at a position away from the center point of the receiving lens 42 by δ in parallel with the axial direction of the shaft of the motor 29 for tilt direction. This offset δ is determined by moving the motor 29 closer to the transmitting lens 41 by the
This is provided to improve the responsiveness by reducing the moment of inertia with respect to 9 to reduce the torque at the time of starting.

The transmitting lens 41 and the receiving lens 42 are aspherical lenses, respectively, and can greatly reduce the focal length as compared with spherical lenses. Transmitting lens 41
Constitutes the light emitting section 23 together with a light emitting element (not shown) provided at a lower portion in a direction perpendicular to the paper surface.
The receiving lens 42 constitutes the light receiving section 24 together with a light receiving element (not shown) provided at a lower portion in a direction perpendicular to the paper surface.

The first shaft 44 supporting the optical transmitting / receiving unit constituted by the light emitting section 23 and the light receiving section 24 is
6 and 47 are rotatably supported. Arms 46, 4
Reference numeral 7 denotes a bifurcated fork-shaped support member together with a back plate 51 supporting one end thereof, and a second shaft 48 as a base shaft extending from the rear surface of the back plate 51 in a direction opposite to the arms 46 and 47. The first bearing 45 is attached to the arms 46 and 47 to support the shaft 44.

The tilt direction motor 29 includes a small-diameter gear (not shown) having a central portion fixed to the motor shaft, a large-diameter gear 52 meshed with the small-diameter gear, and a worm 53 integrally formed with the large-diameter gear 52. , Together with the toothless wheel 54 integrally attached to the first shaft 44, constitutes a first rotation mechanism.

On the other hand, a pan-direction motor 28 (not shown in FIG. 2) has a small-diameter gear 55 whose center is fixed to the motor shaft, a large-diameter gear 56 meshed with the small-diameter gear 55, and a large-diameter gear 56. Worm 5 integrated with
7 and the toothless wheel 58 integrally attached to the second shaft 48 constitute a second rotation mechanism. The second shaft 48 is attached to a second support member 50 via a second bearing 49.

As a result, as shown in the schematic perspective view of FIG. 3, the light transmitting / receiving unit 60 composed of the light emitting section 23 and the light receiving section 24 including the transmitting lens 41 and the receiving lens 42 is provided with a tilt direction motor. Is rotated about the axis 44 in the tilt direction of + θ or −θ in the vertical plane, and is rotated by the pan direction motor in the pan direction of + α or −α in the horizontal plane about the axis 48. .

Here, the light receiving section 24 according to the embodiment of the present invention focuses the incident light by the receiving lens 42 to form a light spot, which is a quadrant photodetector (PD) shown in the plan view of FIG. 70. As shown in FIG. 4A, the quadrant photodetector 70 has a well-known configuration including four photodetectors (divided light receiving areas) PD, PD, PD, and PD. In the present embodiment, the optical axis alignment and the tracking operation are performed using the four-divided photodetector 70.

Further, in the present embodiment, as shown in the plan view of FIG. 5, a predetermined one of the four divided photodetectors 70 provided below the receiving lens 42 is used for communication. A straight line I connecting the center point O of the light detection unit (divided light receiving area) 75 and the center point of the light emitting element 65 provided below the transmission side lens 41 (the center point of the transmission side lens 41); It is characterized in that an interval (offset) β is provided between a straight line II passing through the center point of the receiving lens 42 and being parallel to I. In other words, the center point O of the communication light detection unit (divided light receiving area) 75 and the center point of the light emitting element 65 (center point of the transmission-side lens 41) are located on the same straight line.

This offset β has a completely different purpose from the offset δ in the optical communication apparatus proposed earlier by the present applicant shown in FIG. 2, and one communication light detecting section (divided light receiving area) 75 In order to form an image of a light spot at the center position. Although the planar shape of the optical transmitting / receiving unit 67 of the present embodiment shown in FIG. 5 is slightly different from that of the optical transmitting / receiving unit 60 of FIG. 3 previously proposed by the present applicant, the pan direction motor 28 and the tilt direction The structure is the same as that shown in FIG. 3 in that the motors 29 are independently controlled to rotate in the pan direction and the tilt direction by the motors 29 for use.

Next, the optical axis alignment and follow-up operation of the embodiment shown in FIG. 1 will be described with reference to FIGS. 4, 5, FIG. 6, FIG. 6 and FIG. 7, and the optical scanning order shown in FIG. When the search SW 32 shown in FIG.
According to a program stored in advance in the storage unit 22,
The optical axis alignment and following operation are started by the operations according to FIGS. That is, first, the CPU 20 supplies drive signals to the pan direction motor 28 and the tilt direction motor 29 through the motor driver 27, respectively, and controls the rotation angles of these motors 28 and 29 independently of each other. Is rotated in the pan direction and the tilt direction to search for guide light from the optical transmitting / receiving device by rough scanning (steps 101 and 10 in FIG. 6).
2).

In the above-described optical scanning, for example, as shown in FIG. 8, scanning is performed within a predetermined range from a start position S in a predetermined order shown in ascending numerical order. In FIG. 8, the vertical axis represents the angle in the vertical plane rotation direction (the angle in the tilt direction), the horizontal axis represents the horizontal plane rotation direction (the angle in the pan direction), and “0” to “0”.
“12” indicates scanning in the first scanning range, and “13” to “2”.
“6” indicates scanning in the second scanning range, and “27” to “39” indicate scanning in the third scanning range.

During the light scanning, the CPU 20 outputs a light-receiving level detection signal input to the A / D converter 21 from a light-receiving level detecting circuit 26 for detecting the light receiving level of the light received by the light receiving section 24 in FIG. The CPU 20 monitors whether or not light is detected based on the detected light.
After setting a moving step STEPX (= Nx) in the direction and a moving step STEPY (= Ny) in the y direction (step 103), a light receiving signal from the light receiving section 24 is obtained.
More specifically, a level deviation dVx in the x direction and a level deviation dVy in the y direction are calculated based on a light reception level detection signal input from the quadrant photodetector 70 in FIG. Ask (Step 10
4).

Here, the level deviation dVx is obtained by (PD light receiving level + PD light receiving level)-(PD light receiving level + PD light receiving level), and level deviation dVy is (PD light receiving level + PD light receiving level)-( PD
(Light receiving level + PD light receiving level).

Subsequently, the absolute value | dVx | of the level deviation in the x direction is smaller than a predetermined threshold value Vox,
In addition, it is determined whether the absolute value | dVx | of the level deviation in the x direction is smaller than a preset threshold value Vox (step 105). If this condition is not satisfied, the light spot is shifted to one of them. First, | dVx |
It is determined whether or not ≧ Vox (step 106).
When | dVx | ≧ Vox, the deviation in the x direction is large, so it is determined whether or not the deviation direction is the same as before (step 107). When | dVx | <Vox,
Since the shift in the x direction is smaller than the threshold value Vox, the process proceeds to step 112 described later in FIG. 7 to detect the shift in the y direction.

If it is determined in step 107 that the direction deviating from the previous time is different,
Since the moving step STEPX in the direction is too large, the STEPX is changed to a half value (step 10).
8) On the other hand, when the direction deviating from the previous time is the same, the above-described movement step STEPX in the x direction is not changed, and
Proceeding to step 109 in FIG. 7, the level deviation dVx in the x direction
It is determined whether is negative.

When dVx <0, (light receiving level of PD + light receiving level of PD) <(light receiving level of PD +
(PD light receiving level), (PD light receiving level + PD light receiving level) is (PD light receiving level + P
4A, the pan direction motor 28 is controlled so that the quadrant photodetector 70 moves leftward in FIG. 4A by step STEPX (step 110), and dVx ≧ 0. In the case of, the pan direction motor 28 is controlled so that the quadrant photodetector 70 moves rightward by step STEPX in the opposite direction (step 1).
11).

Subsequently, the same operation as described above is performed in the y direction. That is, it is determined whether or not | dVy | ≧ Voy (step 112). When | dVy | ≧ Voy, the deviation in the y direction is large, so it is determined whether or not the deviation direction is the same as before (step 113). . | D
When Vy | <Voy, the deviation in the y direction is the threshold value Voy.
Since it is smaller, the process proceeds to step 104 in FIG.
The level deviations dVx and dVy in the direction are calculated again.

If it is determined in step 113 that the direction deviating from the previous time is different,
Since the moving step STEPY in the direction is too large, the STEPY is changed to a half value (step 11).
4) On the other hand, when the direction deviating from the previous time is the same, the above-described movement step STEPY in the y direction is not changed.
It is determined whether the level deviation dVy in the y direction is negative (step 115).

When dVy <0, (PD light receiving level + PD light receiving level) <(PD light receiving level +
(PD light receiving level), (PD light receiving level + PD light receiving level) is (PD light receiving level + P
D (light receiving level D), the tilt direction motor 29 is controlled so that the quadrant photodetector 70 moves upward in FIG. 4A by step STEPY (step 116), and dVy ≧ 0. In the case of, the tilt direction motor 29 is controlled such that the quadrant photodetector 70 moves downward by step STEPY in the opposite direction (step 117).

When the processing in step 116 or 117 is completed, the CPU 20 subsequently proceeds to step 10 in FIG.
Proceeding to 4, the level deviations in the x and y directions are calculated again to confirm the result of the previous movement control, and the same operation as above is repeated.

As a result of such movement control, the absolute value | dVx | of the level deviation in the x direction is smaller than the threshold value Vox, and the absolute value | dVy | of the level deviation in the y direction is the threshold value Vo.
When this state is determined in step 105 of FIG. 6, for example, as shown by 71 in FIG. Is present.

Then, in step 105, the absolute value | dVx | of the level deviation in the x direction is smaller than the threshold value Vox, and the absolute value | dVy | of the level deviation in the y direction is the threshold value Vo.
If it is determined to be smaller than y, the correction amount is determined by referring to the correction table stored in the storage unit 22 from the current angle (y direction), and the pan direction motor 28 and the tilt direction motor 29 Each is controlled (step 118).

Here, the above-mentioned correction table is obtained by actually measuring how much the light spot moves to the center of one communication light detecting section (divided light receiving area) for each of a plurality of angles in the y direction. 6 is a table in which a correction amount including a set moving amount and a moving direction is associated with an angle in the y direction. That is, the distance by which the light spot moves from the center of the four-divided photodetector to the center of the communication light detection unit (divided light receiving area) changes depending on the angle in the y direction (tilt angle). The moving distance in the x direction and the moving distance in the y direction corresponding to the angle are stored as a correction table and are referred to. Note that the correction movement amount in the y direction is constant regardless of the angle in the y direction.

The current angle in the y direction (tilt angle)
Is obtained by calculation based on how many steps the tilt direction motor 29 has been driven by the CPU 20 based on the ON point of the tilt direction limit SW 31. The y direction is the horizontal direction in FIG.

As a result, as a result of the movement control of the correction amount in step 118, the light spot on the four-divided photodetector 70, as shown by 72 in FIG. Photodetector (divided light receiving area) 75 (here PD
) Is formed at almost the center position. Therefore, thereafter, by obtaining the reception signal from the light reception signal of the communication light detection unit (divided light reception area) 75, when the reception signal is obtained from one light detection unit in the image forming state of FIG. The received light power can be quadrupled, and the S / S of the received signal can be obtained as compared with the case where the received signal is obtained from the sum signal of the received light signals from all four photodetectors in the imaged state of FIG. N can be improved. As a result, the communication distance can be made longer than that of the proposed device of the present applicant.

As shown in FIG. 5, the center point O of the communication light detecting section (divided light receiving area) 75 and the center point of the light emitting element 65 (center point of the transmitting lens 41) are on the same straight line. Since the light spots are arranged so as to be positioned, as shown by 72 in FIG. 4C, when a light spot is formed at an approximate center position of one predetermined communication light detection unit (divided light receiving area) 75. In addition, not only the optical axis of the communication light detection unit (divided light receiving area) 75 but also the optical axis of the light emitting element 65 can be simultaneously adjusted so as to coincide with the optical axis of the optical transmitter / receiver emitting the guide light. .

Note that the present invention is not limited to the above-described embodiment, and it is only necessary to find out how much the photodetector to be used is shifted on a two-dimensional plane. Photodetectors can also be used. However, 5
In the case of division or more, calculation becomes troublesome. Therefore, actually, division into four is most desirable.

[0048]

As described above, according to the present invention,
A split photodetector having three or more divided light receiving areas on the light receiving surface is used as the light receiving section, and a position where the light receiving level of each divided light receiving area is substantially equal is detected. , A vertical angle) to calculate the amount of movement for directing the optical axis of the divided light receiving area for communication to the partner optical transmitting and receiving device, and by moving the light receiving unit and the light emitting unit by the amount of movement, one predetermined communication is performed. Because the optical axis is aligned with the center of the divided light receiving area, the received light power is lower than when the received signal is obtained from the output light signal of one divided light receiving area at the position where the light receiving level of each divided light receiving area is equal. In addition, the S / N of the received signal can be improved as compared with the case where the received signal is obtained from the sum signal of the output light received signals of all the divided light receiving areas, and therefore, the communication distance can be increased as compared with the related art. Bets can be, can be improved usability of the optical communication device from the communication range is expanded.

Further, according to the present invention, the first straight line connecting the center point of one predetermined divided light receiving area for communication with the center point of the light emitting element constituting the light emitting section, and the first straight line Is parallel to and passes through the center of the split photodetector.
With an arrangement provided with an interval between the straight line and the straight line, it is possible to align the optical axis at the center of one divided light receiving area for communication and at the same time as the optical axis of the light emitting unit.

[Brief description of the drawings]

FIG. 1 is a block diagram of an embodiment of an optical communication device according to the present invention.

FIG. 2 is a plan view of an example of a mechanism previously proposed by the present applicant that can be used as a mechanism of the optical communication apparatus of FIG. 1;

FIG. 3 is a schematic perspective view illustrating rotation of a light receiving unit and a light emitting unit in the mechanism of FIG. 2;

FIG. 4 is a diagram illustrating a quadrant photodetector used by the apparatus of the present invention and an operation description;

FIG. 5 is a mechanism plan view of an embodiment of a main part of the present invention.

FIG. 6 is a flowchart for explaining the operation of the embodiment of FIG. 1 (part 1);

FIG. 7 is a flowchart for explaining the operation of the embodiment of FIG. 1 (part 2);

FIG. 8 is an explanatory diagram of an example of optical scanning according to the embodiment of FIG. 1;

FIG. 9 is a system configuration diagram of an example of a main part of a LAN system to which the present invention can be applied.

[Explanation of symbols]

11b, 12b Optical communication device 20 Central processing unit (CPU) 23 Light emitting unit 24 Light receiving unit 25 Modulation / demodulation large-scale semiconductor integrated circuit (LSI) 26 Light receiving level detection circuit 27 Motor driver 28 Pan direction motor 29 Tilt direction motor 32 Search switch (SW) 41 Transmitting lens 42 Receiving lens 60, 67 Optical transmitting / receiving unit 65 Light emitting element 70 Quadrant photodetector 75 One predetermined photodetection unit for communication (divided light receiving area)

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Masato Nakamura 3-12-12 Moriyacho, Kanagawa-ku, Yokohama-shi, Kanagawa Prefecture Inside the Victor Company of Japan (72) Inventor Yasutoshi Sakai 3-12 Moriyacho, Kanagawa-ku, Yokohama-shi, Kanagawa Address: Victor Company of Japan, Ltd. (72) Kentaro Iguchi 3-12-12 Moriyacho, Kanagawa-ku, Yokohama-shi, Kanagawa Prefecture No. NTT Data Communication Co., Ltd. (72) Inventor Masamichi Sato 3-3-3 Toyosu, Koto-ku, Tokyo Inside NTT Data Communication Co., Ltd. (72) Inventor Kazuki Yanaka Tokyo NTT Data Communication Co., Ltd., 3-3-3, Toyosu, Koto-ku, Tokyo

Claims (3)

[Claims] 1. An optical scanning device that moves a light receiving unit and a light emitting unit while monitoring a light receiving signal from the light receiving unit in order to detect a guide light emitted from an optical transceiver. An optical communication device that performs optical communication between the light receiving unit and the light emitting unit and the optical transmitting and receiving device through the light receiving unit and the light emitting unit after performing optical axis alignment with the optical transmitting and receiving device, wherein the light receiving unit is used as the light receiving unit. A divided light detector having a light receiving area divided into three or more, a light receiving level detecting circuit for detecting each output light receiving signal level of the divided light receiving area of the divided light detector, the light receiving section and the light emitting section A rotation means for integrally controlling the position of the light receiving section based on an external drive signal; and a light spot on the split photodetector based on a light receiving level detection signal output from the light receiving level detecting circuit. x showing the deviation from the central position of the split photodetector position, y
Calculating means for calculating the level deviation in both directions, based on the level deviation calculated by the calculating means, the drive signal to the rotating means so that the absolute value of the level deviation is smaller than a preset threshold value A first driving unit for supplying, and a predetermined divided light receiving area for communication among the divided photodetectors based on positional information of the light receiving unit and the light emitting unit after the driving by the first driving unit is completed. A second drive unit for obtaining a correction amount for setting an optical axis at the center of the second unit, generating a drive signal corresponding to the correction amount, supplying the drive signal to the rotating unit, and correcting the positions of the light receiving unit and the light emitting unit; An optical communication device comprising: 2. A first straight line connecting a center point of a predetermined one of the divided light receiving areas for communication among the split photodetectors and a center point of a light emitting element constituting the light emitting section; 2. The optical communication device according to claim 1, wherein an interval is provided between the second photodetector and a second straight line that is parallel to the straight line and passes through the center of the divided photodetector. 3. The optical communication device according to claim 1, wherein the split photodetector is a four-split photodetector including first to fourth split light-receiving regions.