JP2857306B2 - Optical space transmission equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical transmission apparatus for transmitting information by propagating light into space.

[0002]

2. Description of the Related Art Conventionally, there has been known an optical transmission apparatus for transmitting an information signal in a space by optical means. FIG.
FIG. 1 is a diagram showing an optical system in a conventional optical transmission device disclosed in Japanese Utility Model Laid-Open Publication No. 1-137644. In the figure, information transmission by a light beam is performed between first and second transceivers T1 and T2.

In the first transceiver T1, a light beam emitted from the main light emitting section 1 including an information signal component is transmitted to a lens 2, two beam splitters 3, 4, two lenses 5,
6 in turn and radiated toward the second transceiver T2.
You. The light beam traveling in the direction opposite to the direction of the light beam emitted from the main light emitting unit 1 is reflected by the beam splitter 3, passes through the lens 7, and is received by the light receiving unit 8. The light beam emitted from the sub light emitting unit 9 passes through the lens 10, is reflected by the beam splitter 4, and is emitted through the lenses 5 and 6.

In the second transceiver T2, the received light beam passes through the lenses 11 and 12, is reflected by the beam splitter 13, and is received by the light receiving section 15. Light receiving unit 1
The electric signal generated by 5 is transmitted to the communication information processing circuit 18 and the optical axis deviation detecting circuit 19. The output of the optical axis deviation detecting circuit 19 is transmitted to the light emitting unit driving circuit 20.

On the other hand, light emitted from the light emitting section 16 is radiated through the lens 12, the beam splitter 13, and the lenses 12, 11, and is received by the first transceiver T1. This light
, As described above, it passes through a lens 6,5 and the beam splitter 4, is reflected by the beam splitter 3 passes through the lens 7 and is received by the light receiving unit 8.

As described above, the light beam containing the information signal component is emitted from the main light emitting section 1, passes through the lenses 5, 6 to be radiated into space as a parallel beam and propagated.
This light beam enters the lens 11 of the other transceiver T2, is reflected by the beam splitter 13, detected by the light receiving unit 15, and converted into an information signal by the communication information processing circuit 18. On the other hand, the light beam emitted from the sub-light emitting unit 9 is propagated in space as a divergent light beam. This light beam is
1 has a light beam diameter that is sufficiently larger than the light beam from the main light emitting section 1 on the incident surface. This light beam is also the lens 1
1, 12, the beam splitter 13, and the lens 14 detect the light at the light receiving unit 15.

[0007] Even if a relative displacement occurs between the two transceivers T1 and T2, the light beam diameter from the sub-light-emitting section 9 is sufficiently large and a part thereof is always detected by the light-receiving section 15. Therefore, the optical axis shift detecting circuit 19 detects the amount of shift of the light beam based on the signal from the light receiving section 15, and operates the light emitting section driving circuit 20 with this information signal to send back the information of the optical axis shift from the light emitting section 16. It is. Further, this signal is detected by the light receiving section 8, and the optical axis of the main light emitting section 1 is adjusted. By the above operation, even if a relative displacement occurs between the transmitter and the receiver, the optical axis is immediately corrected and the transmission is not interrupted.

A method of correcting the optical axis is described in, for example, "Preprints of the 1992 IEICE Spring Conference, Lecture No. B-914".
Is disclosed. FIG. 32 shows an optical system for optical axis correction in a conventional optical transmission device. In the figure, 21
Denotes a semiconductor laser which is a light source of a light emitting unit, 22 denotes a lens, 2
Reference numerals 3 denote beam splitters, each of which is shown in FIG.
Corresponding to the semiconductor laser 1, the lens 2, and the beam splitter 3. Reference numeral 24 denotes a movable mirror, reference numeral 25 denotes a movable lens, and lens 26 corresponds to the lens 6 in FIG. 2
Reference numeral 7 denotes a light detector corresponding to the light detector 8 in FIG. 31, and detects a light beam transmitted from the other transceiver (T2 in FIG. 31). Reference numeral 28 denotes an error signal detection circuit connected to the photodetector 27, and reference numeral 29 denotes a control driver connected to the error signal detection circuit 28. Reference numeral 30 denotes an actuator connected to the control driver. The movable mirror 24 and the movable lens 25 are moved based on an error signal (optical axis shift signal) to correct the light beam emission angle.

Also, a detection method is disclosed which enables detection of a light beam itself having an optical axis shift without correcting the optical axis. FIG.
This is a method for detecting a light beam disclosed in Japanese Patent Publication No. 2 and which combines FIGS. 1 and 2 of the above publication. Reference numeral 31 denotes a spherical lens, which corresponds to the lens 14 in FIG. 3
2 is a photodetector divided into n small light receiving surfaces.
Reference numeral 33 denotes a light beam having no optical axis shift, and is incident on the m-th light receiving surface 32-m. Reference numeral 34 denotes a light beam in which an optical axis shift has occurred, and is assumed to be incident on the n-th light receiving surface 32-n. Reference numerals 35 and 36 denote multiplexers to which output signals of the respective light receiving surfaces are connected, and outputs of the multiplexers 35 and 36 are band-pass filters 37 and 3 respectively.
8 and are supplied to a level measurement circuit 41 and a demodulation circuit 43 through amplifiers 39 and 40. A control circuit 42 is connected to the level measurement circuit 41, and signals are transmitted and received between these. The control circuit 42 includes multiplexers 35 and 3
6 is also connected.

The control circuit 42 controls the multiplexer 35 to sequentially select output signals from the light receiving surfaces 32-1 to 32-n one by one. After the noise of the selected signal is removed by the band-pass filter 37, the signal strength is measured by the level determination circuit 41 via the amplifier 39. Control circuit 4
Numeral 2 identifies the light receiving surface that outputs the maximum intensity among the light detectors 32 composed of n light receiving surfaces, and controls the multiplexer 36 to transmit a signal from this light receiving surface to a subsequent circuit. Then, an information signal is extracted by the demodulation circuit 43.
As described above, even if the optical axis shift occurs, the signal levels from the plurality of light receiving surfaces are determined, and the light receiving surface having the maximum intensity is selected, so that the best reception state can be always maintained. Further, subdividing the light receiving surface in this manner has an effect of reducing the influence of unnecessary light such as sunlight and an effect of expanding a frequency band.

Another conventional optical transmission device is disclosed in
No. 4,554,541. FIG. 34 shows this conventional example. In FIG. 34, reference numeral 301 denotes a television camera, and 302 denotes a support column for guiding a signal cable. A transmitter 303 includes a light source such as a light emitting diode and an optical system for condensing light. 304 is a lens provided in the receiver, and 305 is a lens 304
Is a photodetector provided at the focusing position. Reference numeral 306 denotes an amplifier connected to the light detector 305, and reference numeral 307 denotes a video tape recorder connected to the amplifier 306.

A video signal photographed by the television camera 301 is radiated into the space from the transmitter 303 to the receiver as a light beam whose intensity is modulated by a light source such as a light emitting diode. The emitted light beam passes through the lens 30
The light is condensed at 4 and is incident on the photodetector 305 to be converted into an electric signal. This electric signal is amplified by the amplifier 306 and recorded by the video tape recorder 307, or the signal is transmitted to another device (not shown).

[0013]

The prior art described with reference to FIGS. 31 to 33 has the following problems.

First, there is a problem that the relative optical axis deviation between the two transceivers is so large that transmission becomes impossible if the light beam on the transmitter side does not reach the receiver side at all. That is, in the configuration of FIG. 31, the diameter of the light beam emitted from the sub-light emitting unit is increased so that a part of the light beam diameter always reaches the receiver side. Since the energy density of light is reduced and signal quality is degraded, there is a limit to the enlargement of the diameter of the emitted light beam, and an optical axis deviation exceeding this limit is not allowed.

Second, the optical axis correcting mechanism used in the above-mentioned conventional example is more precise than necessary for use in an environment such as indoors, for a short distance and with a small optical axis shift. It is also expensive.

Third, in a method of disposing a large number of small light receiving surfaces and selecting a light receiving surface which outputs the maximum intensity among them,
Although it is possible to detect a light beam within the range where the light receiving surface is provided, transmission has been impossible when the focal point is outside the photodetector due to a large optical axis shift.

Fourth, in two-way transmission, a light beam on the transmission side and a light beam on the reception side may be mixed and incident on the photodetector due to stray light in the optical system. this is,
The signal quality is deteriorated, and strict positioning of the optical system is required to prevent the deterioration.

Fifth, the amount of information that can be transmitted per light beam is limited mainly by the frequency band of the electric circuit.
There was an upper limit. As a countermeasure, it is conceivable to increase the amount of information by transmission using a plurality of light beams. However, signal quality deterioration due to mixing of the light beams is inevitable, and a high-precision light beam separation system has been desired.

Sixth, when the light beam is blocked by passing through, for example, a person, a bird, a shield, or the like, a transmission signal corresponding to the blocking time is lost. In addition, when the optical axis correction operation is performed, the optical axis deviation signal is also cut off, so it takes time to detect the signal again and return to the correction state, or to return when the optical axis deviation is large. It may not be possible.

The conventional optical transmission device described with reference to FIG. 34 has the following problems.

That is, a power supply is indispensable for driving the light source of the transmitter and the amplifier of the receiver. That is, in the case of the transmitter 303, power is supplied by pulling the power cable together with the signal cable from the television camera 301, and in the case of the amplifier 306 in the receiver,
Power had to be supplied by pulling the power cable along with the signal cable to the video tape recorder 307.

In such a case, the video signal in the signal cable receives electromagnetic induction noise from an adjacent power cable,
There has been a problem that signal quality is deteriorated. This problem was also exacerbated as the cable distance increased.

Further, when power cannot be supplied from the television camera 301 or the video tape recorder 307, there is another problem that the device can be used only in the vicinity of other power-supplying devices or places.

Furthermore, when optical transmission is performed using a repeater other than the transmitter and the receiver, there is a problem that power supply means for the repeater must be secured.

[0025]

[0026]

[0027]

The present invention has been made to solve the above problems.
The optical space allows stable detection of the light beam even if the optical axis shifts between multiple transceivers.
It is intended to provide a transmission device.

Another object of the present invention is to increase the allowable value of the deviation of the optical axis in the minor axis direction of a light beam even in a light beam having a non-isotropic cross-sectional shape.

Another object of the present invention is to make it possible for a receiver to always detect a deviation of an optical axis with a predetermined photodetector.

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According to a first aspect of the present invention, there is provided a space optical transmission apparatus including means for equalizing an intensity distribution in a cross section of a light beam so that the light is detected by a photodetector having a light receiving surface smaller than the cross section of the light beam. It was done.

[0053] space optical transmission apparatus according to claim 2, the uniformizing means of the intensity distribution is obtained by forming an optical filter having a predetermined transmittance distribution.

[0054] space optical transmission apparatus according to claim 3, arranged an optical filter into divergent light beam, and is intended to make uniform the intensity distribution by movable in the optical axis direction.

According to a fourth aspect of the present invention, there is provided an optical space transmission apparatus which is smaller than the light beam cross section with respect to the anisotropic light beam cross section.
A photodetector having a rectangular or elliptical light-receiving surface is arranged such that the major axis direction coincides with the minor axis direction of the cross section of the light beam.

According to a fifth aspect of the present invention, there is provided an optical space transmission apparatus including a photodetector for detecting a transmission signal on a receiving side and an element for detecting an optical axis shift of a light beam around the optical detector. In such a case, the optical axis is corrected so as to return to the central photodetector.

According to a sixth aspect of the present invention, there is provided an optical space transmission apparatus in which elements for detecting an optical axis shift of a light beam are configured by arranging a large number of photodetectors in a matrix.

[0058] space optical transmission apparatus according to claim 7, the device for detecting the optical axis deviation of the light beam is obtained by a two-dimensional semiconductor position detecting element.

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In the optical space transmission apparatus according to the first aspect, since the cross-sectional intensity distribution of the light beam is uniform, the detection signal is hardly deteriorated due to the deviation of the optical axis, and the light beam can be detected stably.

[0091] In the optical space transmission apparatus of claim 2, since the transmittance is provided an optical filter increases gradually as it goes around, it can be made uniform sectional intensity distribution of the light beam at the transmitter side with a light source .

[0092] In the optical space transmission apparatus of claim 3, arranged an optical filter into divergent light beam, since the possible transfer <br/> moving the optical axis Direction, Light at the transmitter side with a light source The cross-sectional intensity distribution of the beam can be made uniform.

In the optical space transmission apparatus according to the fourth aspect , for a light beam having a non-isotropic cross-sectional shape, a light detector having a rectangular or elliptical light-receiving surface smaller than the cross-section of the light beam is used. Are arranged so as to coincide with the minor axis direction of the light beam cross section, so that the allowable value of the optical axis shift in the minor axis direction of the photodetector is expanded.

In the optical space transmission apparatus according to the fifth, sixth and seventh aspects, the optical axis deviation in the receiver is detected by the optical axis deviation detecting element , and based on this, the transmission signal having the optical axis at the center is detected. Is corrected so as to be incident on the photodetector.

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EXAMPLES The following first embodiment, with reference to FIGS. 1 to 3, a first embodiment will be described. FIG. 1 shows an optical system in the optical transmission device of the first embodiment. In the figure, reference numerals 44 and 45 denote transceivers, of which the transceiver 44 shows a part related to transmission and the transceiver 45 shows a part related to reception. Reference numeral 46 denotes a light source such as a semiconductor laser, and a lens 48, a beam splitter 49, and a deflection mechanism 50 are arranged in this order on the path of the emitted light beam 47. The deflection mechanism 50 deflects the light beam 47 in two directions in a plane perpendicular to the optical axis. The light beam 47 emitted from the deflecting mechanism 50 propagates in space and enters the other transceiver 45.

In the transmitter / receiver 45, a beam splitter 51, a lens 52, a light receiving element 5
3 are arranged in order. In the reflection direction of the beam splitter 51, a light source 54 such as a semiconductor laser and a lens 55 are disposed. The light beam emitted from the light source 54 passes through the lens 55 and the beam splitter 51, and is the same as the light beam 47 in space. Propagating in the optical path in the opposite direction. In the reflection direction of the beam splitter 49, a lens 56 and a photodetector 57 are sequentially arranged in a direction in which the light beam from the light source 54 is incident.

The photodetector 57 is connected to a detection circuit 58,
The output of the detection circuit 58 is a level indicator (indicator).
59, a light source drive circuit 60, and a deflection mechanism drive circuit 61. The light source drive circuit 60 receives the transmission signal from the signal source 62 and is connected to the light source 46, and the output of the deflection mechanism drive circuit 61 is connected to the deflection mechanism 50.

The light receiving element 53 is connected to the signal detection circuit 63 and the error signal detection circuit 64. The output of the error signal detection circuit 64 is connected to the light source driving circuit 65, and the output of the light source driving circuit 65 is connected to the light source.

On the transmitter / receiver 44 side, the light source driving circuit 60 drives the light source 46 in accordance with the transmission signal from the signal source 62, and the light beam 47 is emitted into space. Light beam 47
Is incident on the other transceiver 45 and detected by the light receiving element 53. From the output of the light receiving element 53, a transmission signal sent from the transceiver 44 is extracted by the signal detection circuit 63. The light receiving element 53 also outputs the incident position of the light beam 47 on the light receiving surface of the light receiving element 53. Error signal detection circuit 64
Detects a deviation of the light beam 47 from a predetermined incident position as an error signal, and the light source driving circuit 65 drives the light source 54 based on the error signal. The light beam from the light source 54 propagates to the transceivers 45 to 44 and enters the photodetector 57. The detection circuit 58 extracts the error signal component, and the level indicator 59 indicates the degree of displacement of the light beam 47. The deflection mechanism driving circuit 61 drives the deflection mechanism 50 based on the error signal, and scans the light beam 47 so that the light beam 47 always enters a predetermined position of the light receiving element 53. Therefore, even if the optical axis of the light beam 47 is deviated, the optical axis can be corrected by the deflection mechanism, so that stable transmission can be performed.

However, for example, when transmission is started from a state in which the power supply is stopped, for example, a large optical axis deviation occurs before the power supply is turned on.
5 may not be incident. Therefore, in this embodiment, when the light beam 47 is not detected, the deflection mechanism 5
The scanning of the light beam 47 is performed by 0. FIG. 2 shows a scanning pattern diagram of the light beam 47. Point O indicates the position of the transmitter / receiver 45, and point A indicates the irradiation position of the light beam 47 from the transmitter / receiver 44 immediately after the power is turned on. In the state of FIG. 2, the point A and the point O are shifted due to the optical axis shift of the light beam 47, so that the transceiver 45 cannot detect the light beam 47. No error signal can be sent back.

Next, the process from the confirmation of the optical axis deviation to the completion of the correction of the optical axis deviation will be described with reference to FIG. First, the light source 46 of the transceiver 44 is turned on (201).
Next, it is determined whether there is an optical axis shift (202). The presence or absence of the optical axis shift is determined by whether or not an error signal is returned from the transceiver 45. When the error signal returns, the optical axis is corrected as it is, and the information is transmitted (203).
However, if the error signal does not return even after the predetermined time has elapsed, it is determined that an optical axis shift has occurred.
In this case, the light beam 47 is scanned according to a certain scanning pattern (204). Scanning pattern is transceiver 4
2 is set so that the light beam 47 is scanned two-dimensionally by an assumed optical axis shift amount.
Then, the light beam 47 is first moved to the start point S and scanned toward the end point E. It is determined whether the light beam 47 has passed through the transceiver 45 during this scanning (205). When the point O of the transmitter / receiver 45 is encountered, the operation of correcting the optical axis starts here, and the correction is automatically performed until the power supply is stopped thereafter (203). If the position O of the transmitter / receiver 45 is not encountered in this scanning, it is determined that the optical axis shift amount is larger than the scanning range, and the scanning range is expanded so that the light beam 47 is scanned in a larger range. (206). After that, the light beam 47 is
This operation is repeated while expanding the scan range until the position 5 point O is passed. By such scanning, the light beam 47 finally reaches the transmitter / receiver 45, and the operation of correcting the optical axis is immediately started. At the same time, information can be transmitted. Thereafter, the correction is automatically performed until the power is stopped.

In the above embodiment, when no error signal is sent from the transmitter / receiver 45 to the transmitter / receiver 44 within a predetermined time after the light beam is emitted from the transmitter / receiver 44, the deviation of the optical axis exceeds a predetermined value. And scanning of the light beam is performed. However, when the light beam is received on the transmitting / receiving side, a signal other than the error signal is transmitted and received from the transmitting / receiving device 45. Alternatively, when this signal is not sent to the transmitter / receiver 44 within the above-mentioned predetermined time, it may be determined that the deviation of the optical axis is equal to or more than a predetermined value.

In FIG. 2, the scanning is performed by returning the parallel lines.
Any pattern may be used. Figure 3 as above
Are performed by the deflection mechanism drive circuit 61. When the transmitter / receiver 44, 45 as shown in FIG. 1 is installed in a place where transmission is desired, the positioning of the transmitter / receiver 45 is adjusted so as to detect the light beam 47, or the light beam 47 enters the transmitter / receiver 45. Thus, the positioning adjustment of the transmitter / receiver 44 is necessary. In the latter method, since the level indicating instrument 59 indicates the degree of deviation of the optical axis, the degree of adjustment can be known on the transmitter / receiver 44 side, and the adjustment operation can be easily performed.

Although shown as a level indicating instrument in FIG. 1,
For example, it may be a sound generator such as a speaker. In this case, depending on the degree of adjustment of the optical axis, it is possible to recognize the degree of adjustment by voice means such as a change in volume, a change in pitch, or a change in the interval between intermittent sounds.

In the optical transmission device, the light beam transmission efficiency varies depending on the cleanliness of air, the presence or absence of smoke, and the like. In the present invention, the light output fluctuation of the light beam is also detected by the error signal detection circuit 64, and this information is transmitted to the transceiver 44 using the light source 54. In the transmitter / receiver 44, the detection circuit 58 detects a signal related to the optical output, and switches the light source 46 to the drive circuit 60
And the light output of the light source 46 is adjusted to maintain the light output of the light beam 47 detected by the light receiving element 53 at a constant value.

Second Embodiment Next, a second embodiment will be described with reference to FIGS. The overall configuration of this embodiment is the same as that of the first embodiment shown in FIG. However, they differ in the following points. FIG. 4 shows FIG.
Only the differences from FIG. As shown, in this embodiment, at one in the transceiver 44, the optical filter 6
7 is inserted between the light source 46 and the lens 48. The optical filter 67 is movable in the optical axis direction. In the other transmitter / receiver 45 , a condenser lens 52 (FIG. 1)
Is not provided, and the received light beam 47 is received by the light receiving element 69 as it is via the beam splitter 51, that is, without passing through the condenser lens. Light receiving element 69
Corresponds to the light receiving element 53 of FIG. 1, but its light receiving surface is smaller than the diameter of the light beam 47 transmitted through the lens 48.

FIG. 5 is a perspective view of a semiconductor laser and a light beam, and FIG. 6 is a sectional intensity distribution diagram of a light beam emitted from the semiconductor laser. Generally, the emitted light beam 47 of the semiconductor laser 46 is divergent, and the cross-sectional shape of the beam (a curve connecting points of predetermined intensity is a cross-sectional shape) is elliptical, and the cross-sectional intensity distribution is not uniform. As shown in FIG. 7A, the light beam has a characteristic of a Gaussian distribution which becomes strong at the center of the light beam and becomes smooth and weak at the periphery.

On the other hand, as the optical filter 67, FIG.
The one having the transmittance distribution shown in FIG. This portion has the same ellipticity as that of the semiconductor laser 46, and has such a distribution that the transmittance is low at the center and smoothly increases at the periphery. Therefore, the light beam 47 of the semiconductor laser 46 transmitted through the optical filter 67 has a substantially uniform cross-sectional intensity distribution. The light receiving element 69 has a light receiving surface
8 is smaller than the diameter of the light beam 47 transmitted through the light receiving element 8, the light beam can be stably detected even if an optical axis shift occurs within a range where the diameter of the light beam 47 and the light receiving surface of the light receiving element 69 overlap. Transmission can be performed without any trouble.

Since the divergence of the semiconductor laser 46 is different from one another, the uniformity of the sectional intensity distribution can be optimized by moving and adjusting the optical filter 67 in the direction of the optical axis in the divergent light beam.

Third Embodiment Next, a third embodiment will be described with reference to FIG. The overall configuration of this embodiment is the same as that of FIG. 1, and only different portions are shown in FIG. 4, the same reference numerals as those in FIG. 4 denote the same or corresponding members. A light receiving element 71 in the transceiver 45 has a rectangular or elliptical light receiving surface smaller than the diameter of the light beam 70. The light beam 70 is arranged such that the major axis direction thereof coincides with the minor axis direction of the light receiving element 71.

As described in the second embodiment, if the shape of the light receiving element 71 is smaller than the diameter of the light beam, a deviation of the optical axis within a range where the both overlap is allowed. Generally, the light receiving surface of a commercially available light receiving element is circular, square, or rectangular.
However, as shown in FIG. 5, the cross section of the light beam emitted from the semiconductor laser 46 is elliptical. When a circular or square light receiving surface is used as the light receiving element 71, the overlapping range in the short axis direction (x direction) is narrower than the long axis direction (y axis) as shown in FIG. The value also gets smaller. In the present invention, as shown in FIG. 8, the light receiving element 71 having a rectangular or elliptical light receiving surface is disposed so that its short axis direction coincides with the long axis direction of the light beam 70.
Is shifted in the short axis direction (x direction), the overlapping range with the light receiving element 71 is widened, and as a result, the allowable value of the optical axis shift is expanded.

Fourth Embodiment Next, a fourth embodiment will be described with reference to FIG. The overall configuration of this embodiment is the same as that of the first embodiment, and only different parts are shown in FIG. This part shows a receiving part which forms a part of the transceiver 45. In the figure, 47, 52 and 63 are the same as those in FIG. Numeral 72 denotes a light receiving means corresponding to 53 in FIG. 1. The light detector 72a is located at the center and detects a transmission signal, and a large number of optical axis shift detecting elements 72b are arranged around the light detector 72a.
It is composed of The output of the light detector 72a is connected to the signal detection circuit 63. Optical axis deviation detecting element 72b
Are connected to the detection circuit 73, and the output of the detection circuit 73 is connected to the control circuit 74. The output of the control circuit 74 is connected to a deflection mechanism driving circuit 75 for driving the deflection mechanism 76. In this embodiment, the deflecting mechanism 76 drives the lens 52 in two directions perpendicular to the optical axis and orthogonal to each other, but may be of another type.

When an optical axis shift occurs in the light beam 47,
The focal point shifts from the position of the central photodetector 72a and moves to one of the optical axis shift detecting elements 72b arranged around the photodetector 72a. The control circuit 74 takes in the detection signal from each optical axis deviation detecting element 72b and determines to which element the condensing point has moved. Further, the control circuit 74 obtains a correction amount of the deflection mechanism 76 necessary for returning the focal point to the position of the central photodetector 72a, and drives the deflection mechanism 76 with the deflection mechanism drive circuit 75. Although the deflection mechanism 76 is shown as being provided on the receiving unit side of the transceiver, it may be provided on the transmitting side.
In this case, the error signal must be transmitted to the transmitting side, and the transmission method shown in FIG. 1 may be used for this.

[0134] Instead of the shown to the light receiving means 72 in FIG. 9, FIG. 10
May be used. In FIG.
Reference numeral a denotes a photodetector at the center for detecting a transmission signal, around which a two-dimensional semiconductor position detecting element 77b is disposed. The two-dimensional semiconductor position detecting element has a large light receiving area, continuously covers the periphery of the photodetector 77a, receives a light beam, and can output coordinate data representing the light receiving position. The movement of the condensing point due to the optical axis shift is detected by the two-dimensional semiconductor position detecting element 77b, and corrected so as to return to the central photodetector 77a.

Fifth Embodiment Next, a fifth embodiment will be described with reference to FIG. FIG.
In FIG. 1, reference numeral 83 denotes one transceiver,
50, 56, 57, 60 to 64 are the same as those in FIG. 84 is a light source of wavelength λ1, 85 is disposed between the lens 48 and the deflection mechanism 50, transmits the wavelength λ1, and transmits the wavelength λ2 (λ
This is a dichroic prism that reflects (2 ≠ λ1).
86 is the other transceiver, and 87 is a light source of wavelength λ2. The difference between the transceiver 86 and the transceiver 83 is that the light source 87 and the lens 48 are arranged on the reflection side of the dichroic prism 85, and the lens 56 and the photodetector 57 are arranged on the transmission side of the dichroic prism 85. And the other parts are the same.

An outgoing light beam 88 of wavelength λ 1 from a light source 84 in one transceiver 83 is applied to a dichroic prism 8.
5, the optical axis is corrected by the deflection mechanism 50, and the light is radiated and propagated into space. This light beam 88 enters the other transceiver 86, passes through the dichroic prism 85, and is detected by the light detector 57. Similarly, the transceiver 8
The light beam 89 of wavelength λ2 from the light source 87 in the light source 6 is totally reflected by the dichroic prism 85,
, The optical axis is corrected, and the light propagates in space. This light beam 89 enters the other transceiver 83, is totally reflected by the dichroic prism 85, and is detected by the light detector 57. The operation of the circuit system and the optical axis correction is the same as in FIG.

As described above, in each of the transceivers 83 and 86, the dichroic prism 85 is the same as the transceivers 83 and 86.
The light beam from the light source inside and the light beam from the other transceivers 86 and 83 are separated based on the difference in the wavelength.

Sixth Embodiment Next, a sixth embodiment will be described with reference to FIG. The overall configuration of this embodiment is the same as FIG. FIG. 12 shows only different parts. 48 to 51, 54 to 57
Is the same as FIG. Reference numeral 90 denotes a transmitting unit of the transceiver 44, reference numeral 91 denotes a light source for emitting a P-polarized light beam 92, and reference numeral 93 denotes an S-polarized light beam 9 having the same wavelength as the light source 91.
4 are converted into parallel light beams by a lens 48, respectively. 95 transmits the light beam 92,
This is a polarization beam splitter that reflects the light beam 94 and combines the light beam 94 so as to travel in the same direction. Reference numeral 96 denotes a receiving unit of the other transmitter / receiver 45, and reference numeral 97 denotes a P-polarized light beam 92 incident on the same optical path, and transmits an S-polarized light beam 9.
4 is a polarization beam splitter that reflects the light beam 4.

[0139] The P-polarized light beam 92 from the light source 91 of the transmitting unit 90 of one of the transceivers passes through the polarization beam splitter 95, and the S-polarized light beam 9 from the light source 93.
Numeral 4 reflects the polarization beam splitter 95, and the two light beams are propagated in space with their optical axes corrected by the deflection mechanism 50. These light beams 92 and 94 are incident on the receiving section 96 of the other transceiver, the light beam 92 is transmitted through the polarization beam splitter 97 and detected by the first photodetector 57, and the light beam 94 is transmitted to the polarization beam splitter The light 97 is reflected and detected by the second photodetector 57. The light source 54 is for transmitting an error signal or the like for optical axis correction to the transceiver 44 side, and may have the same wavelength as the light sources 91 and 93 or a different wavelength.

As described above, one transmitter / receiver combines P-polarized light and S-polarized light from different light sources 91 and 93, and the other transmitter / receiver separates P-polarized light and S-polarized light to provide different light receiving sections 57.
Incident on

As described above, since a plurality of light beams having different polarization directions are used for transmission by a plurality of light beams in the same direction, the amount of transmission can be increased.

In the above embodiment, the receiving section 96
Although the polarization beam splitter 97 is used to separate the two light beams 92 and 94, the following configuration may be adopted. That is, the polarization beam splitter 97 is a normal non-polarization beam splitter. An analyzer positioned so as to transmit only P-polarized light is provided on the front surface of the first light detector 57 for detecting the light beam 92, and an S-polarized light is provided on the front surface of the second light detector 57 for detecting the light beam 94. An analyzer positioned to transmit only the light is provided. Therefore, the first light detector 5
7, only the P-polarized light beam is detected.
Are selectively detected. Similarly, the second light detector 57 selectively detects the S-polarized light beam 94.

Seventh Embodiment Next, a seventh embodiment will be described with reference to FIG. In the figure, 48, 50, 56, and 57 are the same as those in FIG. 1, and 97 is the same as in FIG. Reference numeral 106 denotes one transceiver, 107 is a light source that emits a P-polarized light beam 108 at a wavelength λ1, and 109 is the same wavelength as the light source 107.
a light source that emits an S-polarized light beam 110 at λ1 ,
Each is converted by the lens 48 into a parallel light beam. 11
Reference numeral 1 denotes a polarizing beam splitter that transmits the light beam 108 and reflects the light beam 110 to combine the light beams 110 in the same direction. Numeral 112 is disposed in the emission direction of the polarization beam splitter 111, transmits the wavelength λ1, and transmits the wavelength λ2.
This is a dichroic prism that reflects (λ2 ≠ λ1). 113 denotes the other transceiver, and 114 denotes the wavelength λ.
Reference numeral 2 denotes a light source that emits a P-polarized light beam 115, and reference numeral 116 denotes a light source that emits an S-polarized light beam 117 at the same wavelength λ2 as the light source 114. 118 transmits the light beam 115,
This is a polarization beam splitter that reflects the light beam 117 and combines the light beam 117 so as to travel in the same direction. Reference numeral 119 denotes a dichroic prism that is disposed in the emission direction of the polarization beam splitter 118 and transmits the wavelength λ2 and reflects the wavelength λ1. Basically two transceivers 106 and 113
Are different in that the wavelength of the transmission light in each transceiver is different, and the configuration and operation in other parts are the same.

Wavelength λ from light source 107 of transceiver 106
At 1, the outgoing light beam 108 of P polarization transmits through the polarizing beam splitter 111, the outgoing light beam 110 of S polarization at the wavelength λ1 from the light source 109 is reflected by the polarizing beam splitter 111, and both light beams pass through the dichroic prism 112. Then, the optical axis is corrected by the deflecting mechanism 50 and the light is propagated in space. These light beams 108 and 110 are incident on a transceiver 113. These two light beams 108 and 110 are reflected by the dichroic prism 119. Further, the P-polarized light beam 108 passes through the polarizing beam splitter 97 and is detected by the first photodetector 57, and the S-polarized light beam 110 is reflected by the polarizing beam splitter 97 and is detected by the second photodetector 57. It is detected at 57.

On the other hand, the outgoing light beam 115 of P polarization at the wavelength λ2 from the light source 114 of the transmitter / receiver 113 passes through the polarization beam splitter 118 , and the S beam at the wavelength λ2 from the light source 116.
The polarized output light beam 117 is directed to the polarization beam splitter 11.
8 , the two light beams are reflected by the dichroic prism 11
9, the optical axis is corrected by the deflecting mechanism 50, and the light propagates through space. The light beams 115 and 117 are
The light enters the transceiver 106. These two light beams 11
5 and 117 are reflected by the dichroic prism 112. Further, the P-polarized light beam 115 passes through the polarization beam splitter 97 and is detected by the first photodetector 57, and the S-polarized light beam 117 is reflected by the polarization beam splitter 97 and is transmitted to the second photodetector. It is detected at 57.

In the above embodiment, the transmitting / receiving unit 106 uses the polarization beam splitter 111 to combine the two light beams 108 and 110, but may use a normal non-polarization beam splitter. Also, two light beams 115 and 1
Although the polarization beam splitter 97 is used for the separation of 17, the following configuration may be adopted. That is, the polarization beam splitter 97 is a normal non-polarization beam splitter.
An analyzer positioned so as to transmit only the P-polarized light is provided on the front surface of the first light detector 57 for detecting the light beam 115, and an S-polarized light is provided on the front surface of the second light detector 57 for detecting the light beam 117. An analyzer positioned to transmit only the light is provided. Therefore, only the P-polarized light beam is detected by the first photodetector 57, and the light beam 115 is selectively detected. Similarly, the second light detector 57 selectively detects the light beam 117 of the S-polarized component. The above also applies to the other transceiver 113.

In the above-described embodiment, the light beams 108 and 110 having the wavelength λ1 and the wavelength λ
Although the dichroic prism 112 is used to separate the two light beams 115 and 117 from each other, the following configuration may be adopted. That is, the dichroic prism 112 is a normal beam splitter. Light beams 115 and 117
Are provided on the front surfaces of the first and second photodetectors 57 for detecting the wavelength .lambda. These light detectors 57 selectively detect a light beam of wavelength λ2. The above is the other transceiver 11
The same applies to No. 3.

Further, the following configuration may be adopted in the above embodiment. That is, in the transceiver 106,
The polarizing beam splitters 97 and 111 and the dichroic prism 112 are assumed to be ordinary beam splitters. On the front surface of the first photodetector 57 that detects the light beam 115, an analyzer coated with an interference filter film so as to transmit only the P-polarized light at the wavelength λ2, the light beam 1
The wavelength λ is provided on the front surface of the second photodetector 57 for detecting
2 and an analyzer coated with an interference filter film so as to transmit only S-polarized light is provided. Therefore, the first photodetector 57 detects only the P-polarized light beam at the wavelength λ2, and selectively detects the light beam 115. Similarly, the second light detector 57 selectively detects the light beam 117 of the S polarization component at the wavelength λ2. The above also applies to the other transceiver 113.

Further, light sources having three or more different wavelengths may be used.

Eighth Embodiment Next, an eighth embodiment will be described with reference to FIG. In the figure, reference numerals 46 to 57 are the same as those in FIG. 1
Reference numeral 20 denotes one of the transceivers, and reference numeral 121 denotes a beam splitter disposed on the emission side of the deflection mechanism 50. A reflection mirror 122 is provided in the reflection direction of the beam splitter 121. Reference numeral 123 denotes the other transceiver, and the beam splitter 51 is disposed so that the transmitted light beam 47a of the beam splitter 121 enters. Reference numeral 125 denotes a beam splitter that is provided so as to receive the light beam 47b from the reflection mirror 122. A lens 52 and a photodetector 53 are sequentially arranged in the transmission direction or the reflection direction of the beam splitter 125, and a lens 55 and a light source 54 are sequentially arranged in the other direction.

The light beam 47 emitted from the light source 46 is incident on the beam splitter 121 after the optical axis is corrected by the deflection mechanism 50. The transmitted light beam 47a of the beam splitter 121 is propagated into the space, and the reflected light beam 47b is reflected by the reflecting mirror 122, so that the transmitted light beam 4a
The light is propagated into the space in parallel with 7a. Transmitted light beam 47a
Enters the beam splitter 51 of the other transceiver 123 and is detected by the first photodetector 53. On the other hand, the reflected light beam 47b enters the beam splitter 125 and is detected by the second photodetector 53. Similarly, the light beam 126 from the light source 54 is also emitted from the two beam splitters 51 and 125 and detected by the photodetector 57 of the other transceiver 121.

As described above, since a light beam is simultaneously propagated through two different optical paths, even if one optical path is interrupted, transmission can be performed by the other optical path.

Ninth Embodiment Next, a ninth embodiment will be described with reference to FIG. In the figure, 127 is a transceiver capable of transmitting in two directions,
128 is a transceiver capable of receiving from two directions, and 129 is a repeater capable of receiving in one direction and transmitting in one direction. The transceiver 127 includes the transceiver 128 and the repeater 12.
9 is possible, and the repeater 129 is capable of transmitting to the transceiver 128.

Light beams carrying the same signal are transmitted from the transceiver 127 to the transceiver 128 and the repeater 129 at the same time. Further, the repeater 129 is connected to the transceiver 12.
The light beam from 7 is transmitted directly to the transceiver 128. Transceiver 128 receives transmissions from transceiver 127 and repeater 129 simultaneously.

As a result of this configuration, the transceiver 12
7 can receive the light beam from the transceiver 127 by the transmission from the repeater 129 even when the direct transmission from 7 is interrupted.

In the above embodiment, the transceiver 127 is used.
Can transmit in two directions, the transceiver 128 can receive in two directions, and the repeater 129 can receive and transmit in one direction. However, the transmitter 127 can transmit in three or more directions. A transmitter / receiver 128 capable of receiving in three or more directions is used. Two or more repeaters (similar to 129) are provided, and one of the light beams generated by the transmitter / receiver 127 is directly The light beam may be transmitted to the transceiver 128, and the other light beams may be transmitted via the repeaters.

Tenth Embodiment Hereinafter, a tenth embodiment will be described with reference to FIGS. FIG. 16 is a block diagram showing the overall configuration of the optical transmission device according to the tenth embodiment of the present invention. In the figure, 308 is a first transceiver, 309 is a repeater, 31
0 is a second transceiver.

FIG. 17 is a block diagram showing details of the first transceiver 308. In the figure, reference numeral 311 denotes a signal source of a signal to be transmitted, and may be various signal sources such as a video signal source such as a television camera and a VTR, and a code data signal source such as a computer and a personal computer. Reference numeral 312 denotes a signal from the signal source 311 to the first transceiver 308.
This is a cable for transmitting a signal from the signal source 311, and may be, for example, an electric wire or an optical fiber. The cable 312 is connected to the light source driving circuit 313,
The light source driving circuit 313 is connected to a light source 314 such as a light emitting diode or a laser diode. The collimator lens 315 and the beam splitter 3
16, relay lenses 317 and 318 are arranged in this order. In the reflection direction of the beam splitter 316, a converging lens 319 and a photodetector 320 are sequentially arranged. An output signal of the photodetector 320 is connected to a detection circuit 321, and one output signal of the detection circuit 321 is connected to a signal regenerator 323 outside the first transceiver 308 via a cable 322. The other output signal of the detection circuit 321 is connected to a deflection mechanism drive circuit 324, and the output signal of the deflection mechanism drive circuit 324 is connected to a deflection mechanism 325 provided on one relay lens 317. Deflection mechanism 3
25 can displace the relay lens 317 in two orthogonal directions in a plane perpendicular to the optical axis. 326 is a solar cell, which is directed to receive a light beam S from sunlight or illumination light. Although 326 is a solar cell here, other power generating means may be used. 327 is a determination circuit connected to the solar cell 326,
And are interconnected. The output from the determination circuit 327 is connected to a circuit system and a driving mechanism that require a power supply in the first transceiver 308. However, only the connection with the light source driving circuit 313 is shown in the drawing for simplicity.

FIG. 18 is a block diagram showing details of the repeater 309. In the figure, 329 is the first transceiver 3
08 is a beam splitter for transmitting and reflecting the light beam emitted from the light emitting device 08. Beam splitter 329
In the transmission direction, a converging lens 330 and a photodetector 331 are arranged in order, while in the reflection direction, a collimator lens 332 and a light source 333 are arranged in order. The output signal of the light detector 331 is connected to the detection circuit 334,
One output signal of the detection circuit 334 is connected to the error signal detection circuit 335. Error signal detection circuit 335
Is connected to a light source driving circuit 336, and a light source 333 is connected to a stage subsequent to the light source driving circuit 336. The other output signal of the detection circuit 334 is connected to a light source driving circuit 337, and a light source 338 is connected to a stage subsequent to the light source driving circuit 337. The collimator lens 339, beam splitter 340,
Relay lenses 341 and 342 are arranged in order. A converging lens 34 is provided in the reflection direction of the beam splitter 340.
3. Photodetectors 344 are arranged in order. Light detector 3
The output signal of the error signal detection circuit 345 is connected to the error signal detection circuit 345, and the output signal of the error signal detection circuit 345 is connected to the deflection mechanism drive circuit 346.
6 is connected to a deflecting mechanism 347 provided on one relay lens 341. The deflection mechanism 347 is the first
The relay lens 341 can be displaced in two orthogonal directions in a plane perpendicular to the optical axis, similarly to the polarization mechanism 325 in the transmitter / receiver 308. Further, the solar cell 326, the determination circuit 327, and the storage battery 328 provided in the repeater 309 are the first battery.
Are the same as those provided in the transceiver 308 of FIG.
However, for simplicity of illustration, only the connection with the detection circuit 334 is shown.

FIG. 19 is a block diagram showing the details of second transceiver 310. In the figure, 348 is the repeater 3
09 is a beam splitter for transmitting and reflecting the light beam emitted from the light emitting element 09. Beam splitter 348
A converging lens 349 and a light detector 350 are arranged in this order in the transmission direction, while a collimator lens 351 and a light source 352 are arranged in order in the reflection direction. The output signal of the light detector 350 is connected to the detection circuit 353,
One output signal of the detection circuit 353 is connected to the error signal detection circuit 354. Error signal detection circuit 354
Is connected to a light source driving circuit 355, and a light source 352 is connected to a subsequent stage of the light source driving circuit 355. The other output signal of the detection circuit 353 is a cable 356
Is connected to a signal regenerator 357 outside the second transceiver 310. The signal reproducer 357 reproduces and processes the transmitted signal, and may be, for example, a television monitor, a VTR, or a personal computer. 358 is a signal source outside the second transceiver 310 and is connected to the light source drive circuit 355 via the cable 359. Further, a solar cell 326 provided in the second transceiver 310, a determination circuit 327,
The storage battery 328 is the same as that provided in the first transceiver 308. However, for simplicity of illustration, only the connection with the detection circuit 353 is shown.

First, the operation when a signal is transmitted from the first transceiver 308 to the second transceiver 310 will be described. The signal to be transmitted from the signal source 311 is the cable 31
2, the light source driving circuit 313 of the first transceiver 308
Is transmitted to The light source driving circuit 313 drives the light source 314 based on the transmission signal, and the light source 314 emits a light beam as an optical signal. The form of the transmission signal may be analog or digital, and may be modulated if necessary. The light beam propagates through the beam splitter 316 and the relay lenses 317 and 318 to the repeater 309.

In the repeater 309, the first transceiver 308
Is received by the photodetector 331, and the detection circuit 334 detects a transmission signal. On the other hand, the signal from the detection circuit 334 is
5, a signal (error signal) indicating the incident position of the light beam on the photodetector 331 is detected. This error signal is for causing the light beam to always enter a predetermined position of the photodetector 331. If there is a relative displacement between the first transceiver 308 and the repeater 309, transmission by a light beam cannot be performed and a signal is interrupted. Therefore, this error signal is sent back from repeater 309 to first transceiver 308. This is because the light source driving circuit 336 in the repeater 309 drives the light source 333 based on the error signal, and the light source 333 emits a light beam toward the first transceiver 308.

This light beam is received by the light detector 320 in the first transceiver 308, and the detection circuit 321 detects an error signal component. This error signal component is converted by the deflection mechanism drive circuit 324 into a signal for operating the drive mechanism 325 provided on the relay lens 317. The drive mechanism 325 displaces the relay lens 317 in two directions orthogonal to each other in a plane perpendicular to the optical axis according to the error signal. As a method of the driving mechanism 325, for example, a method using an electromagnetic force by a coil and a magnet is exemplified. As a result, the direction of the light beam emitted from the first transceiver 308 is changed such that the light beam always enters a predetermined position on the photodetector 331 surface of the repeater 309. In this way, even if the position shift occurs between the first transceiver 308 and the repeater 309 during transmission, the radiation direction of the light beam is corrected as needed, so that transmission is not interrupted. In addition, the first transceiver 30
8 and the repeater 309 can transmit a signal even on a moving body such as a broadcast relay vehicle. However, in addition to the case where the position shift occurs during transmission, there is also a case where there is a large position shift before the start of transmission and the light beam emitted from the first transceiver 308 does not reach the repeater 309 at all. Can be In such a case, the first transceiver 3
08 is scanned in a predetermined pattern toward the repeater 309. If the repeater 309 can detect the light beam being scanned, the error signal described above is used. What is necessary is just to perform the correction operation. Such correction can be performed by the method described in relation to the above embodiment. The transmission signal detected by the detection circuit 334 of the repeater 309 is also transmitted to the light source driving circuit 33.
7 and the light source 338 again converts it into a light beam,
It is radiated towards the second transceiver 310. Repeater 3
09, the method of detecting the light beam and the signal component in the second transceiver 310, the second transceiver 3
The transmission method of the error signal from 10 to the repeater 309 is the same as described above. Further, a method of correcting a light beam due to a displacement between the repeater 309 and the second transceiver 310 is similarly performed by the relay lens 341 and the driving mechanism 347.

The transmission signal detected by the second transceiver 310 is transmitted via a cable 356 to an external signal regenerator 35.
7 and reproduced in the form of video, audio or code data signals. The solar cell 326 generates electric power by irradiation of sunlight or surrounding illumination light. The determination circuit 327 supplies the electric power generated by the solar cell 326 to an electric circuit system and a driving mechanism that require a power supply. In addition, during non-transmission, the power generated by the solar cell 326 is stored in the storage battery 32.
Make sure to save at 8. Further, when the power generated by the solar cell 326 is small, such as at night, the storage battery 328
To supply power. The fact that the first transceiver 308, the repeater 309, and the second transceiver 310 have power generation means makes it unnecessary to supply power from the outside, which is effective for the optical transmission device. In particular, in the case of the repeater 309, complete cablelessness can be realized, and the installation is extremely excellent.

It is to be noted that the first transceiver 308 and the repeater 3
Although a case has been described where a signal is transmitted in one direction to the second transceiver 310 through the step 09, bidirectional transmission can also be performed. That is, the signal source 3 is provided outside the second transceiver 310.
58, and the light source driving circuit 35 via the cable 359.
5 to transmit the signal. The light source 352 superimposes the signal from the signal source 358 on the error signal component of the light beam emitted from the repeater 309 in the second transceiver 310 and emits the light beam toward the repeater 309. This light beam is detected by the light detector 344, and the light source driving circuit 33
It is conveyed to 6. The light source 333 is an error signal detection circuit 3
The signal from the photodetector 344 is superimposed on the error signal component from 35 and a light beam is emitted toward the first transceiver 308. This light beam is detected by the detection circuit 321 of the first transceiver 308, and then transmitted to an external signal regenerator 323 via the cable 322.

In the above embodiment, the repeater 309 was used. By using the repeater 309, even when there is an obstacle on a straight line connecting the first transceiver 308 and the second transceiver 310, the repeater 309 is arranged at a position away from the straight line. Transmission becomes possible.

In the repeater 309 of the above embodiment,
The light beam propagated from the first transceiver 308 may be attenuated in the atmosphere, and the signal component may be weak. Therefore, by amplifying the transmission signal in the repeater 309 and then transmitting the amplified signal to the second transceiver 310, the signal quality can be maintained or improved.

It should be noted that the first and second transceivers 308,
If there is no obstacle on the straight line connecting 310 and the distance between the first and second transceivers 308, 310 is sufficiently short,
The repeater 309 can be omitted.

The repeater 309 of the above embodiment not only relays signals between the first transceiver 308 and the second transceiver 310, but also connects a signal source and a signal regenerator to the repeater 309. A new signal may be input / output at the point of the repeater 309.

In order to further clarify the operation of the optical transmission apparatus shown in FIGS. 16 to 19, an actual use example will be described. FIG. 20 is an installation diagram of the optical transmission device of this embodiment at an outdoor music stage venue. In the figure, 360 is a stage. Reference numeral 361 denotes a television camera for photographing the state of the stage 360, and corresponds to the signal source 311 in FIG. Reference numeral 362 denotes two transmitters connected to the television camera 361, and corresponds to reference numeral 308 in FIG. 363
Is a solar cell connected to the transmitter 362, and corresponds to the reference numeral 326 in FIG. Reference numeral 364 denotes two receivers arranged in a direction to receive the light beams emitted by the two transmitters 362, respectively, and includes a solar cell 363. 3
65 is a monitor screen connected to the receiver, 3
66 is a speaker. The monitor screen 365 and the speaker 366 correspond to the signal reproducer 357 in FIG. The size of the outdoor music stage venue varies depending on the location, for example, from the stage 360 to the monitor screen 3
The distance at which 65 is installed is about 100 meters.

[0171] The television camera 361 captures an image of the stage 360, and this signal is transmitted from the transmitter 362 to the receiver 364.
Up to about 100 meters, the image is projected on the monitor screen 365, and the sound is played on the speaker 366. Power for the transmitter 362 and the receiver 364 is supplied from a solar cell 363 provided for each. Therefore, it is not necessary to draw a cable to supply power to the transmitter 362 and the receiver 364, and the installation of the transmitter 362 and the receiver 364 becomes extremely easy. In particular, such an audio-visual device in the field is often provisionally installed in accordance with an event, and an optical transmission device equipped with a solar cell is suitable for mobility and temporary installation. In addition, when used at night, the power generated by the solar cell during the day may be stored in a storage battery, and this power may be used. As another method, a solar cell can be installed near the lighting equipment.

FIG. 21 shows another example of use of the present embodiment in a case where it is installed in a baseball field. In the figure, 367 is a baseball field, 368 is a control center for handling various information in the baseball field, and 369 is a back screen. On the back screen 369, a receiver 373 is integrated in addition to the large display 370, the score board 371, and the member board 372. Reference numeral 374 denotes television cameras installed at several places in the baseball stadium, each having a transmitter and a power generation means. Reference numeral 375 is a television monitor similarly installed at several places, each having a receiver and a power generation means. The transmitter of each television camera 374 is installed so that light can be transmitted toward the control center 368 as shown by the solid line in the figure, and the receiver of each television monitor 375 is transmitted from the control center 368 as shown by the solid line in the figure. It is installed so that it can receive light. The receiver 373 on the back screen 369 is installed so as to be able to receive light transmission from the control center 368. The distance from the control center 368 to each of the television cameras 374 and each of the television monitors 375 is about several tens to hundreds of meters.

FIG. 22 is a block diagram of an information path between the control center 368, the television camera 374, and the television monitor 375. Reference numeral 376 denotes an optical transmission device installed in the control center 368 and having transmission and reception functions. Each television camera 374 is used not only for shooting the pattern of the game and the state of the players, but also for monitoring the state of the spectators and the baseball stadium, and a video signal is transmitted to the control center 368 via a transmitter. The signals received by the optical transmission device 376 of the control center 368 are separated by the distributor 377 into signals from the respective television cameras 374.
Each video signal is displayed on the television monitor 378. The signal of each television monitor 378 is connected to a television monitor selector 379. TV monitor selector 37
9 selects a video signal to be displayed on the large display 370, for example. 380 is a television broadcast receiver, 381 is a laser disk, and 382 is a computer, which is connected to the mixer 383 together with the television monitor selector 379. These correspond to the signal source 311 in FIG. TV broadcast receiver 380 and laser disk 3
81 is used for providing information to spectators and for entertainment before the start of a game. The computer 382 controls the scoreboard 37
It is used for inputting a score to 1, inputting a player name to the member board 372, providing various other information, and controlling these information paths. Each signal is mixed by the mixer 383 and transmitted from the optical transmission device 376 to the receiver of each television monitor 375. In the television monitor 375, the transmitted mixed signal is distributed to each video signal, and a signal to be projected at each location is selected and projected on the television monitor. The selection of the signal to be projected is performed by the computer 382.
Signal.

In FIG. 21, each TV monitor 37
5 are all transmitted from the control center 368.
5 may be relayed in order.

Note that a similar configuration may be adopted when the present invention is similarly used not only in a baseball field but also in a soccer field, various other stadiums, exhibition halls and the like.

FIG. 23 shows an arrangement when the optical transmission device of the tenth embodiment is used in a boat racetrack. In the figure, reference numerals 368 to 370, 373, 3
74 is the same as FIG. Reference numeral 384 denotes a boat racecourse pool, and 385 denotes a boat. Reference numeral 386 denotes a board on the back screen 369 that displays the order of arrival and the like.
The distance from the control center 368 to each of the television cameras 374 and the back screen 369 is approximately several tens to hundreds of meters. As in the case of a baseball stadium, each television camera 374 is used for photographing a state of a race or for monitoring in a boat racetrack, and a video signal is transmitted to a control center 368. From the control center 368, a large display 370 on the back screen 369 is displayed.
And a signal to be displayed on the display board 386 are edited and transmitted. When a new information route is to be constructed in an existing boat racetrack, the pool 38 is used in the conventional method using electric wires.
4 or bypassing the pool 384, the wiring work had to be performed, which required a large construction cost. On the other hand, in the transmission method using light,
There is a great advantage that an information route can be easily opened simply by installing a device. Eleventh Embodiment Next, an eleventh embodiment will be described with reference to FIG. This embodiment is generally the same as the tenth embodiment except that no repeater is provided, but differs in the following points. FIG.
FIG. 4 shows only differences from the tenth embodiment. In the transmitter 308 of FIG. 24, 314 is a first light source for transmitting a signal, 313 is an electric circuit for driving the light source, and 318 is a first optical system for emitting a first light beam 434. It is. 435 is the first light source 314
And a second light source having the same wavelength or a different wavelength.
Emitted in parallel with the light beam. 444 is the second light source 4
32 is an electric circuit for driving the P.32. Also, the receiver 3
In 10, 350 is a photodetector arranged to receive the first light beam 434, the output of which is connected to the detection circuit 353. 440 is the first light source 314
This is an optical filter that transmits only the wavelength components described above, and is disposed in front of the photodetector 350. Reference numeral 441 denotes a solar cell arranged to receive the second light beam 437. The output of the solar cell 441 is an electric circuit unit in the receiver 310 and a signal regenerator 357 and a signal source 35 connected to the receiver 310.
8 (FIG. 19).

The first light beam 434 emitted from the first light source 314 and the optical system 318 is received by the photodetector 350 to transmit a signal.
This is the same as the embodiment. The second light source 435 is the light beam 4
37 is provided to supply power to the receiver 310, and is driven at a constant value higher in light output than the first light source 314 . The light beam 437 is
0 is received by the solar cell 441, and the obtained power is supplied to the light receiver 310 and the signal regenerator 357 and the signal source 358 connected thereto. Optical filter 44
0 is provided to prevent the light beam 437 from the second light source 435 and other stray light components from being incident on the photodetector 350 and deteriorating the quality of the transmitted signal.

In FIG. 24, two light beams 434 and 437 are radiated from different optical systems 318 and 436, respectively, but they may be radiated from the same optical system.

Twelfth Embodiment Next, a twelfth embodiment will be described with reference to FIG. The overall configuration of this embodiment is the same as in FIGS. FIG. 25 shows only different parts. That is, in this embodiment, the configuration of the repeater 387 is different. Other points are shown in Fig. 1.
6 to FIG. 19. In the figure, reference numeral 326 is used.
To 328, 330, 340, 343 to 346 are the same as those in FIG. One end of an optical fiber 388 is positioned and disposed at the converging point of the converging lens 330, and a collimator lens 389 is disposed at the other end of the optical fiber 388. Further, a deflection mechanism 390 is disposed close to the collimator lens 389 of the optical fiber 388. The deflection mechanism 390 can displace the optical fiber 388 in two orthogonal directions in a plane perpendicular to the optical axis. The output signal of the error signal detection circuit 345 is input to the deflection mechanism driving circuit 346, and a deflection mechanism 390 is provided at a stage subsequent to the deflection mechanism driving circuit 346. The determination circuit 327 is connected to the error signal detection circuit 345 and the deflection mechanism drive circuit 346.

The light beam emitted from the transmitter (not shown) enters the optical fiber 388 via the converging lens 330 of the repeater 387. This light beam is emitted as it is from the emission end of the optical fiber 388, and is emitted from the repeater 387 to the receiver (not shown) via the collimator lens 389 and the beam splitter 340. On the other hand, on the other hand, the light beam emitted from the receiver toward the repeater 387 is shown in FIG.
As described in FIG. 6, the signal including the position shift signal of the incident position at the receiver is included in the beam splitter 340.
And is received by the photodetector 344 via the converging lens 343. Then, the error signal detection circuit 345 detects a position shift signal. The deflection mechanism drive circuit 346 drives the deflection mechanism 390 based on the position shift signal, and positions the output end of the optical fiber 388 so that the light beam emitted from the optical fiber 388 is incident on a predetermined position of the receiver. Is adjusted. The signal transmission in the repeater 387 is performed through the optical fiber 388 in the form of an optical signal, and is not converted into an electric signal. Therefore, there is no electromagnetic induction noise, and the quality of the transmission signal does not deteriorate.

Thirteenth Embodiment Next, a thirteenth embodiment will be described with reference to FIG. FIG. 26 shows a floodlight of this embodiment. The repeater and the receiver may be the same as those shown in FIG. Alternatively, the repeater shown in FIG. 25 may be used. In FIG. 26, reference numeral 311 is the same as in FIG. 391
Is a transmitter. The signal from the signal source 311 is transmitted via the optical fiber 392 to the optical fiber coupler 39 of the transmitter 391.
3 to the first input port 394. 395
Is a semiconductor laser for excitation, and the emitted light is a converging lens 39.
6, the second input port 3 of the optical fiber coupler 393
97 has been entered. An optical fiber 399 is connected to an output port 398 of the optical fiber coupler 393, and an optical isolator 400 is connected to an emission end of the optical fiber 399. At the subsequent stage of the optical isolator 400, an erbium-doped optical fiber 401 in which erbium ions are mixed into the core is connected. An optical filter 402 is connected to an emission end of the erbium-doped optical fiber 401, and an optical fiber 403 is connected at a later stage. A collimator lens 404 is provided near the emission end of the optical fiber 403.

The optical fiber coupler 393 and the erbium-doped optical fiber 401 are well known as a technique of an optical fiber amplifier. Journal of the Japan Society of Applied Physics, Vol. 59, No. 9, (1990) 1175 to 1192.
Explained on the page. A signal from the signal source 311 is input to the optical fiber coupler 393 via the optical fiber 392 as, for example, signal light having a wavelength of 1.53 μm. On the other hand, for example, pumping light emitted from a pumping semiconductor laser 395 having a wavelength of 1.48 microns is also input to the optical fiber coupler 393 via the converging lens 396. In the optical fiber coupler 393, these two lights are combined with an efficiency of 95% or more, and two lights are superposed and output from one output port 398. The optical fiber coupler is described on pages 260 to 262 of “Lightwave Electronics” (written by Koyama and Nishihara, Corona Co., Ltd.), and the detailed description is omitted here. These signal light and pump light are propagated to the erbium-doped optical fiber 401. Here, the stimulated emission of the erbium ion at a unique transition
The signal light is amplified. In addition, the optical isolator 400
It functions to prevent light components in the erbium-doped optical fiber 401 from returning to the optical fiber coupler 393 side. Also,
The optical filter 402 operates to pass only the amplified signal light. Therefore, the amplified signal light is emitted from the output end of the optical fiber 403. Thus, the output signal of the signal source 311 is radiated from the transmitter 391 under the amplifying action in the form of an optical signal. Therefore, there is no electromagnetic induction noise, and the quality of the transmission signal does not deteriorate.

Fourteenth Embodiment Next, a fourteenth embodiment will be described with reference to FIG. FIG. 27 shows a receiver according to this embodiment. The transmitter and the repeater may be the same as those shown in FIG. Alternatively, the repeater shown in FIG. 25 may be used. Alternatively, the transmitter shown in FIG. 26 may be used. The receiver of the present embodiment (FIG. 27) is obtained by applying the optical fiber amplifier described in the thirteenth embodiment (FIG. 26) to a receiver. In FIG. 27, reference numeral 405 denotes a receiver. Code 3
57 is the same as FIG. Reference numerals 393 to 403 are the same as those in FIG. Reference numeral 406 denotes a converging lens for converging a light beam emitted from a transmitter or a repeater, and an optical fiber 407 at a converging point is provided. The other end of the optical fiber 407 is the optical fiber coupler 3
93 is connected to a first input port 394. An optical fiber 403 is connected to a stage subsequent to the optical filter 402, and an output end of the optical fiber 403 is input to a signal regenerator 357.

The light beam emitted from the external transmitter or repeater has a wavelength of, for example, 1.53 microns.
The light is input to the optical fiber coupler 393 via the converging lens 406. On the other hand, for example, the excitation light emitted from the excitation semiconductor laser 395 having a wavelength of 1.48 μm is also convergent lens 3
The signal is input to the optical fiber coupler 393 via the signal line 96. In the optical fiber coupler 393, these two lights are combined with an efficiency of 95% or more, and two lights are superposed and output from one output port 398. These signal light and pump light are propagated to the erbium-doped optical fiber 401,
As described above, the signal light is amplified by the action of erbium ions. The amplified signal light is input to the signal regenerator 357 via the optical fiber 403. Thus, the receiver 40
The light beam received by 5 receives an amplifying action in the form of an optical signal and is input to the signal regenerator 357. Therefore, there is no electromagnetic induction noise, and the attenuation of the light beam intensity caused by propagation in the atmosphere is restored,
The quality of the transmission signal does not deteriorate.

In the above embodiment, an optical fiber having an amplifying function is used for the transmitter and the receiver. However, an optical fiber having this amplifying function may be used for the repeater.

Fifteenth Embodiment Next, the present invention will be described with reference to FIGS. 28 and 29. FIG. 28 shows a transmitter according to this embodiment.
The repeater and the receiver described in the above embodiment can be used. In FIG. 28, reference numeral 311 is the same as in FIG. Reference numeral 408 denotes a transmitter, and the signal source 311 and the transmitter 408 are connected by an optical fiber 409. 410
Is a converging lens disposed near the exit end of the optical fiber, and 411 is an optical amplifying element disposed near the converging point of the converging lens. A collimator lens 412 is provided in the emission direction of the optical amplification function element 411.

FIG. 29 is a cross-sectional view showing an example of the optical amplification function element 411, which is introduced in Optoelectronics Encyclopedia (Industry Research Council, 1992), pp. 115-116. Both surfaces are sandwiched between Au-Zn electrodes 411a and 411b, and an N-InP emitter 411d, a p-InGaAsP gate 411e, and an n-
InGaAsP buffer layer 411f, N-InP buffer layer 41
1 g, n-InGaAsP absorption layer 411 h, N-InP
Cladding layer 411i, n-InGaAsP active layer 411
j, p-InP cladding layers 411k are sequentially stacked. Here, the emitter 411d, the gate 411e, the buffer layers 411f and 411g form a phototransistor,
Active layer 411j and cladding layers 411i and 411k on both sides
Form a light emitting element. Therefore, the light emitted from the light emitting element is output in response to the light incident on the phototransistor side. The signal from the signal source 311 is input to the transmitter 408 via the optical fiber 409 in the form of an optical signal. This optical signal enters the optical amplifying function element 411, is amplified, emitted, and radiated from the transmitter. That is, the amplification operation can be performed in the form of the optical signal.

In the above description, "N-" indicates that the concentration of electrons is high, and "n-" indicates that the concentration of electrons is relatively low.

In this embodiment, the case where the optical amplifying function element 411 is provided in the transmitter is shown, but it goes without saying that it may be provided in the repeater or the receiver.

Next, in order to further clarify the operation of the optical transmission apparatus shown in the thirteenth to fifteenth embodiments in the form of a block diagram, an actual use example will be described. FIG. 30 is an installation diagram showing inter-building transmission of the optical transmission device according to the thirteenth to fifteenth embodiments of the present invention. Reference numeral 412 denotes a building, which is built across the road ST and the like. 413
Is an optical transmission device having transmission and reception functions, and is installed on, for example, the roof of a building. Reference numeral 414 denotes an information path using optical fibers installed on each floor of the building 412, and an information path 414 on each floor is a main path 415 using optical fibers.
It is connected to the. The trunk route 415 is connected to the optical transmission device 413 for each building. Two optical transmission devices 413
The distance between them is from several tens to hundreds of meters.

In each building unit, a LAN system (Local Area Network) comprising an information route 414 and a main route 415 is provided.
ork) is laid, and computers and information-related equipment in the building are connected by optical fibers. With this system, information in the building is transmitted through optical fibers. The optical transmission device 413 installed in another building is also provided by the optical transmission device 413 in the system path.
Information communication with each other is performed via the communication device 3. Therefore, the optical transmission device 413 between buildings acts as if the buildings are connected by an optical fiber.

In the above embodiment, the transmission was performed between two buildings. However, the transmission may be performed between three or more optical transmission devices.

Although the information route 414 and the trunk route 415 in the building are optical fibers, they may be electric wires.

[0194]

[0195]

[0196]

[0197]

[0198]

[0199]

[0200]

[0201]

As described above , according to the optical space transmission apparatus of the first aspect , the cross-sectional intensity distribution of the light beam is made uniform, and the light beam is directly detected by the photodetector having a light receiving surface smaller than the cross section. With this configuration, the lens can be omitted, the optical axis deviation can be allowed within a range where the light beam cross section and the light receiving surface overlap, and there is an effect that a high-precision optical axis correction mechanism is not required.

According to the optical space transmission apparatus of the second aspect , since the optical filter whose transmittance gradually increases toward the periphery is provided, the cross-sectional intensity distribution of the light beam is made uniform on the transmitter side provided with the light source. it can.

[0203] According to the optical space transmission apparatus of claim 3, since the adjustable along the optical axis in divergent light beam of the optical filter, the light beams of uniform cross-sectional intensity regardless of the characteristics of the light source can be obtained effects There is.

According to the optical space transmission device of the fourth aspect, the light receiving surface of the light detector is rectangular or elliptical smaller than the anisotropic light beam cross section, and the short axis direction of the light beam is longer than the length of the light detector. Since they are arranged so as to coincide with the axial direction, there is an effect that the allowable value of the optical axis deviation can be expanded.

In the optical space transmission apparatus of claims 5, 6 and 7,
According to the optical axis correction to detect with the central photodetector
Therefore, stable detection can be performed even if a large optical axis deviation occurs.
This has the effect.

[0206]

[0207]

[0208]

[0209]

[0210]

[0211]

[0212]

[0213]

[0214]

[0215]

[0216]

[0219]

[0218]

[0219]

[0220]

[0221]

[0222]

[0223]

[0224]

[0225]

[0226]

[Brief description of the drawings]

1 is a schematic view and a circuit connection diagram of an optical system in the optical space transmission apparatus of the first embodiment.

FIG. 2 is a scanning pattern diagram of a light beam in the optical free space transmission apparatus according to the first embodiment.

FIG. 3 is a flowchart illustrating a control operation of scanning a light beam in the optical free space transmission apparatus according to the first embodiment.

FIG. 4 is a schematic diagram of an optical system in an optical transmission device according to a second embodiment of the present invention.

FIG. 5 is a perspective view of a semiconductor laser and an emitted light beam.

FIG. 6 is a sectional intensity distribution diagram of a light beam emitted from a semiconductor laser.

FIG. 7 is a schematic diagram and a transmittance distribution diagram of an optical filter in an optical transmission device according to a second embodiment of the present invention.

FIG. 8 is a perspective view of an optical system in an optical transmission device according to a third embodiment of the present invention.

FIG. 9 is a schematic diagram and a circuit connection diagram of an optical system for detecting a light beam in an optical transmission device according to a fourth embodiment of the present invention.

FIG. 10 is a schematic diagram showing another example of the light receiving element in the optical transmission device according to the fourth embodiment of the present invention.

11 is a schematic view and a circuit connection diagram of an optical system in the optical space transmission apparatus of the fifth embodiment.

12 is a schematic diagram of an optical system in the optical space transmission apparatus of the sixth embodiment.

13 is a schematic diagram of an optical system in the optical space transmission apparatus of the seventh embodiment.

14 is a schematic diagram of an optical system in the optical space transmission apparatus of the eighth embodiment.

15 is a schematic diagram showing the optical space transmission apparatus of the ninth embodiment.

16 is a block diagram showing an optical space transmission apparatus of the tenth embodiment.

FIG. 17 is a block diagram showing a first transceiver in the optical transmission device of FIG. 16;

FIG. 18 is a block diagram showing a repeater in the optical transmission device of FIG.

19 is a block diagram showing a second transceiver in the optical transmission device of FIG.

FIG. 20 is a set up view of outdoor music stage hall space optical transmission apparatus according to a tenth embodiment.

21 is a set up view of a baseball field of the optical space transmission apparatus of the tenth embodiment.

FIG. 22 is a block diagram of an information path of the free- space optical transmission apparatus according to the tenth embodiment.

23 is a installation diagram in Motorboat field optical space transmission apparatus of the tenth embodiment.

FIG. 24 is a block diagram showing an optical space transmission device according to an eleventh embodiment.

FIG. 25 is a block diagram showing an optical space transmission device according to a twelfth embodiment.

FIG. 26 is a block diagram showing an optical space transmission device according to the thirteenth embodiment.

FIG. 27 is a block diagram showing an optical space transmission device according to a fourteenth embodiment.

FIG. 28 is a block diagram showing an optical space transmission device according to a fifteenth embodiment of.

29 is a cross-sectional view of an optical amplification function elements in the optical space transmission apparatus according to a fifteenth embodiment of.

FIG. 30 shows light according to the thirteenth to fifteenth embodiments.
It is an installation view showing transmission between buildings of a space transmission device.

FIG. 31 is a schematic diagram and a circuit connection diagram of an optical system in a conventional optical transmission device.

FIG. 32 is a schematic diagram and a circuit connection diagram of an optical system for optical axis correction in a conventional optical transmission device.

FIG. 33 is a schematic diagram of an optical system and a circuit connection diagram showing a method of detecting a light beam in a conventional optical transmission device.

FIG. 34 is a block diagram of a conventional optical transmission device.

[Explanation of symbols]

44, 45 , 83, 86 , 90, 96, 106, 11
3, 120, 123, 127 , 128: transceivers 46, 54, 84, 87, 91, 93, 107, 10
9, 114 , 116, 314, 338, 435: Light sources 47, 70, 82, 88, 89, 92, 94, 108,
115, 117, 126: Light beams 48 , 52 , 55 , 56: Lens 50, 76 , 347 , 390: Deflection mechanism 53 , 69 , 77a: Light receiving element 57, 71, 72a, 77b, 331, 344, 35
0: photodetector 58, 73 , 334 , 353: detection circuit 59: level indicating instrument 60, 65, 313, 337 , 444: light source drive circuit 61, 75, 346: deflection mechanism drive circuit 62, 311, 358: signal Source 63: Signal detection circuit 64: Error signal detection circuit 395: Semiconductor laser 67: Optical filter 72b: Optical axis deviation detecting element 77: Semiconductor position detecting element 80, 95, 97, 111, 118: Polarizing beam splitter 81: Four One-half wavelength plates 85, 112, 119: dichroic prisms 49, 51, 95, 97, 121 , 125: beam splitter 122: reflection mirrors 129, 309, 387: repeaters 308, 362, 391, 408: transmitter 310 , 364, 373, 405: Receiver 312, 322, 356, 359: Cable 31 5, 318, 339, 436: Collimator lenses 317, 318, 341, 342: Relay lenses 323, 357: Signal regenerators 326, 363, 441 : Solar cells 327: Judgment circuit 328: Storage batteries 330, 343, 349: Convergent lenses 335: Error signal detection circuit 376, 413: Optical transmission device 388, 392, 399, 403, 409: Optical fiber 393: Optical fiber coupler 400: Optical isolator 401: Erbium-doped optical fiber 402: Optical filter 411: Optical amplifying function element

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI H04B 10/24 (72) Inventor Tomohiro Hase 1 Baba Zoshosho, Nagaokakyo-shi, Kyoto Prefecture Mitsubishi Electric Corporation Video Systems Development Laboratory (56 References JP-A-51-57102 (JP, A) JP-A-63-153926 (JP, A) JP-A-57-85775 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB Name) H04B 10/10-10/105 H04B 10/22 G02B 7/00

Claims (7)

(57) [Claims] A transmitter (44) and a receiver (45), wherein the transmitter (44) includes a light source (46) and the light source (4).
Means (48, 49) for emitting the light beam from 6)
And means (67) for making the cross-sectional intensity distribution of the output light beam uniform, and the receiver (45) includes means (69) for detecting the output light beam from the transmitter (44). An optical space transmission apparatus, wherein the detecting means receives the light beam without passing through a condenser lens and has a light receiving surface smaller in size than a cross section of the light beam. 2. The means for making the cross-sectional intensity distribution uniform,
The optical sky according to claim 1 , wherein the optical filter is an optical filter (67) whose transmittance is low at a central portion where the light beam is incident and gradually increases toward the periphery.
During transmission device. 3. The optical space transmission apparatus according to claim 2 , wherein the optical filter is arranged in a divergent light beam of the light beam, and is movable in an optical axis direction. 4. A light source (46) comprising a transmitter (44) and a receiver (45), wherein the transmitter (44) has a light source (46) having an anisotropic cross-sectional intensity distribution in a plane direction perpendicular to an optical axis. Means (48, 4) for emitting a light beam from the light source (46).
9), wherein the receiver (45) includes means (69) for detecting the outgoing light beam from the transmitter (44), and the detecting means passes the light beam through a condenser lens. Without receiving light, and has a rectangular or elliptical light receiving surface smaller in size than the cross section of the light beam, the short side or short axis direction of the light receiving surface coincides with the long axis direction of the outgoing light beam that it is arranged such that the optical space transmission apparatus according to claim. 5. A transmitter (44) and a receiver (45), wherein the transmitter (44) includes a light source (46) and the light source (4).
Means (48, 49) for emitting the light beam from 6), wherein at least one of the transmitter (44) or the receiver (45) comprises means (76) for deflecting the light beam; The receiver (45) includes means (72) for detecting the outgoing light beam from the transmitter (44), and the detecting means is disposed around the central light detector (72a, 77a). A light receiving element (72b, 77b), which makes the outgoing light beam incident on the photodetector based on a detection signal from the light receiving element.
Spatial transmission equipment. 6. 請 characterized in that said light receiving element is a plurality of light detectors arranged in a matrix (72b)
Optical space transmission apparatus according to Motomeko 5. 7. The optical space transmission apparatus according to claim 5 , wherein said light receiving element is a two-dimensional semiconductor position detecting element (77b).