JPH05227100A - Light space transmitting device - Google Patents

Abstract

PURPOSE:To display the servo operational point when the light axes of light beams are made matched by performing the bidirectional transmission between a transmitter-receiver and the other one by means of the light beam modulated by an information signal. CONSTITUTION:Light beam L21 sent from the other transmitter-receiver 2 is detected by a position sensor 25 through mirrors 11 and 12 located in one transmitter-receiver 1. By adjusting the mirrors 11 and 12 through servo circuit 24 and motors 22 and 23 according to the detection output by servo operation, the light axis of the optical beam L21 is adjusted to display the servo operational point based on the detection output on a view finder 43 through the servo circuit 24 and a mixed circuit 42.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention particularly relates to an optical space transmission device adapted to transmit desired information by a light beam transmitting space.

[0002]

2. Description of the Related Art In an optical space transmission device, for example, a transmitting / receiving device installed on the roof of one building emits a light beam modulated by an information signal, and the light beam is installed on the roof of another building. The signal is received by the other transmitting / receiving device, and the video camera is operated under the control of the other transmitting / receiving device based on the received light beam, and the output information signal (for example, video signal and audio signal) from this video camera is received. Is converted into a light beam again by the other transmission / reception device, and the converted light beam is received by the one transmission / reception device.

With such a configuration, the operation of the video camera installed together with the other transmitter / receiver at a remote position can be controlled, and the information signal output from the video camera is installed in the one transmitter / receiver. Can be obtained at the designated position.

As a conventional optical space transmission apparatus related to such a configuration, there is, for example, the apparatus disclosed in Japanese Utility Model Application Laid-Open No. 2-52433 filed by the present applicant.

In this optical space transmission device, a video camera having a viewfinder is incorporated in the one transmitting / receiving device, and the video camera emits light from the one transmitting / receiving device into the viewfinder. It has become possible to simultaneously display an image of a light beam point and a scene including the other transmission / reception device. While looking at the viewfinder, by moving the one transmission / reception device so that the emitted light beam point image and the other transmission / reception device image overlap, the optical axis direction of the one transmission / reception device and the other transmission / reception device This is so that they can be roughly matched.

In this optical space transmission device, the servo operation for matching the optical axis directions is started in such a state that the optical axis directions roughly match. During the servo operation, the deviation amount of the light beam transmitted from the other transmitting / receiving device to the one transmitting / receiving device in the optical axis direction is detected by the light beam position detecting means in the one transmitting / receiving device. Based on the detection output, the optical axis direction of the light beam is adjusted by the servo operation so that the optical axis directions of the one transmission / reception device and the other transmission / reception device are accurately matched.

Then, after the optical axis directions are exactly matched,
In the one transmitter / receiver, the optical axis is fixed by releasing the servo operation and fixing the operating point, and the optical axis is aligned with the light beam position detection means and arranged in the one transmitter / receiver. The light beam information detection means receives the light beam from the other transmitting / receiving device, and the information is obtained by the detection output of the light beam information detection means.
Usually, the detection range (servo possible range) of the light beam position detection means and the detection range of the light beam information detection means are the same range.

[0008]

However, in the above-described conventional optical space transmission device, when the optical axis direction is accurately matched by the servo operation, which operating point (hereinafter referred to as necessary) in the servoable range is set. It was not clear whether the servo operation was canceled at the operation point of the servo operation or the servo operation point). Therefore, when it is fixed to the operation point with a small margin, in other words, the detection of the light beam information detection means is performed. If the part near the periphery of the range is designed to receive the light beam from the other transmission / reception device and perform communication, the one transmission / reception device or the other transmission / reception device may be affected by vibration or the like. Even if it moves a little, it may exceed the detection range of the light beam information detection means immediately. In the worst case, mutual transmission is impossible. There has been a problem that it is.

The present invention has been made in view of the above problems, and an object thereof is to provide an optical space transmission device capable of displaying a servo operating point.

[0010]

The optical space transmission apparatus of the present invention, for example, as shown in FIGS. 1 and 4, transmits / receives a light beam L ₂₁ sent from another transmission / reception apparatus 2 to one transmission / reception apparatus 1.
An optical space transmission device which is detected by the light beam position detecting means 25 through the optical axis adjusting means 11 and 12 arranged inside and adjusts the optical axis adjusting means 11 and 12 by a servo operation according to the detected output. At the one transmitter / receiver 1
A display means 43 is provided in the display means 43, and operating points 65 and 66 (see FIG. 4) of the servo operation based on the detection output of the light beam position detection means 25 are displayed on the display means 43.

[0011]

According to the optical space transmission device of the present invention, the display means 43 is provided.
Since the operating points 65 and 66 of the servo operation are displayed on the screen, a servo range (for example, 65
A, 66A) cancels the servo operation and fixes the servo operation point, so that it is possible to perform stable mutual transmission between one transceiver 1 and another transceiver 2.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the optical free space transmission apparatus of the present invention will be described below with reference to the drawings.

FIG. 1 shows an optical space transmission device as a whole,
This free-space optical transmission apparatus has one transmission / reception apparatus 1 (hereinafter, also simply referred to as transmission / reception apparatus 1) and another transmission / reception apparatus 2 (hereinafter, also simply referred to as transmission / reception apparatus 2) having substantially the same configuration,
A light beam modulated with an information signal is transmitted and received between the transmitting and receiving devices 1 and 2.

The transmitter / receiver 1 has an optical block 3,
The laser diode 4 constituting the optical block 3 emits the light beam L ₁ modulated by the information signal. The information signal is supplied as a current signal from the transmission signal processing circuit 6 to the laser diode 4 under the control of the system controller 5.

The light beam L ₁ emitted from the laser diode 4 has a lens 7 and a polarization beam splitter 10.
After passing through the mirrors, the mirrors 11 and 12 as optical axis adjusting means
Then, the light is transmitted from the transmitter / receiver 1 as a light beam L ₁₁ parallel to the optical axis 15 toward the transmitter / receiver 2 opposite thereto through the lens 13 and the light transmitting / receiving lens 14.

The direction of the optical axis 15 of the light beam L ₁₁ (the central axis of the light beam bundle of the light beam 11) is predetermined in the direction of arrow P about the axis 20 extending in the direction orthogonal to the paper surface of the mirror 11. It is possible to change the predetermined angle by rotating the mirror 12 by an angle and rotating the mirror 12 by a predetermined angle in the arrow Q direction around the shaft 21 extending in the direction parallel to the paper surface.

The axis 20 of the mirror 11 and the mirror 1
The rotation angle of the second shaft 21 is determined by the rotation angle of the rotation shafts of the motors 22 and 23, and the rotation angle of the rotation shafts of the motors 22 and 23 is determined according to the output signal of the servo circuit 24. The characteristics of the output signal supplied from the servo circuit 24 to the motors 22 and 23 are determined by the servo circuit 24 according to the output signal of the position sensor 25 as the light beam position detecting means, as will be described later.

A collimating scope 30 is arranged on the front surface of the transmitting / receiving lens 14. In this case, of the light beams L ₁₁ sent to the transmitter / receiver 2, a part of the light beams reflected by the half mirror 31 becomes the extracted light beam L ₁₂ for detecting the light beam emission position. The extracted light beam L ₁₂ is incident on the video camera 35 as a part of the imaging light L ₁₄ through the optical paths of the half mirror 32, the prism 33, the half mirror 32, and the telephoto lens 34.

Here, the collimating scope 30 is arranged so that the optical axis 40 of the imaging light L ₁₄ is substantially parallel to the optical axis 15 of the outgoing light beam L ₁₁ . An opening 41 is provided in the collimator scope 30 along the optical axis 40, and the subject light L ₂₂ incident through the opening 41 is passed through the half mirror 32 and the telephoto lens 34 as the remaining part of the imaging light L _{14 to be} a video camera. It is incident on 35. The subject light L ₂₂ includes image information representing the transmitter / receiver 2 and a scene around the transmitter / receiver 2.

Therefore, on the image pickup surface (not shown) of the video camera 35, a light spot formed by the above-mentioned extracted light beam L12 and a light image having image information representing the transmitter / receiver 2 and the surrounding scene of the transmitter / receiver 2 are formed. An image is formed, and the video signal S ₁ corresponding to these images is sent through the mixing circuit 42 to the viewfinder 4 serving as display means.
3 is supplied as a video signal S _{2 to the} image of the image formation on the screen of the viewfinder 43.

The light beam L ₂₁ emitted from the other transmitter / receiver 2 has its polarization plane changed by 90 ° from that of the light beam L ₁₁ . The light beam L ₂₁ is received by the light transmitting / receiving lens 14, travels backward in the optical path of the light beam L ₁₁ , and enters the polarization beam splitter 10 as the light beam L ₂ through the mirrors 12 and 11.

The light beam L ₂ incident on the polarization beam splitter 10 is reflected by the polarization beam splitter 10 and is incident on the half mirror 45. Part of the light beam L ₂ is transmitted by the half mirror 45 and part of it is reflected. .. The light beam L ₂₃ transmitted through the half mirror 45 is incident on the photodiode 51, which is light beam information detecting means, through the lens 50. The photodiode 51 supplies an electric signal S ₃ corresponding to the information signal included in the light beam L ₂₃ to the reception signal processing circuit 51.

The received signal processing circuit 51 demodulates the electric signal S ₃ , that is, the signal corresponding to the light beam L ₂₁ sent from the transmitter / receiver 2 to form an information signal.
This information signal is output to an external device (not shown) under the control of the system controller 5.

On the other hand, the light beam L ₂₄ reflected by the half mirror 45 enters the position sensor 25 as a light beam position detecting means through the lens 52. Position sensor 25
2, has a square position detection element 53 having a side length of 2 L, and output terminals 54 to 57 are provided on an extension of the center line of the position detection element 53. In this embodiment, the detection area of the position detection element 53 and the light detection area of the photodiode 51 described above are selected to be the same area, and the photodiode 51 and the position sensor 25 are substantially coaxial. Optically placed on top of each other.

In this case, the light spot La corresponding to the light beam L ₂₄ is imaged on the position detecting element 53, and the deviation amount x and the deviation amount y of this light spot La from the origin position (0,0) are formed. Corresponding to the current signals X ₁ , X ₂ , Y ₁ and Y ₂ ,
Respectively supplied to the output terminals 54, 55, 56, 57,
It is output from the position sensor 25.

The servo circuit 24 calculates the deviation amount x and the deviation amount y from the origin position (0,0) on the basis of these current signals X ₁ , X ₂ , Y ₁ , and Y ₂ by the following equations 1 and 2 Calculate by

[0027]

[Formula 1] x = L · (X ₂ −X ₁ ) / (X ₁ + X ₂ ).

[0028]

[Equation 2] y = L · (Y ₂ −Y ₁ ) / (Y ₁ + Y ₂ ).

Therefore, the servo circuit 24 starts the servo operation according to the servo start command from the system controller 5 so that the deviation amounts x and y become zero values.
In this case, the servo loop includes the servo circuit 24, the motor 2
2, 23, the mirrors 11 and 12, the polarization beam splitter 10, the half mirror 43, the lens 52, and the position sensor 25.

In this embodiment, servo is applied to any portion within the area of the position detecting element 53, and as shown in FIG. 3, the origin position (0,0) of the position detecting element 53 is The central range indicated by the hatching that is included is the servo range A1, which is a range with a very high degree of stability,
A range indicated by halftone dots around it is a servo range A2 having a relatively large margin of stability, and a range surrounded by hatching in the opposite direction is a servo range A3 having a small margin of stability. It

The information signal indicating the servo range A1 to A3 indicating the stability of the servo operation is supplied to one input terminal of the mixing circuit 42 as the video signal S ₅ .

[0032] Here, the other input terminal of the mixing circuit 42, according to the object light L ₂₂ having image information representative of the scene around the light spot and the receiving device 2 and the receiving device 2 by extracting light beam L12 obtained by the Video signal S representing an image
₁ is supplied.

A video signal S indicating a cursor is output from the cursor generation circuit 59 to the other input terminal of the mixing circuit 42 in response to a control signal from the system controller 5.
₆ are supplied.

Therefore, the mixing circuit 42 mixes these video signals S ₁ , S ₅ , and S ₆ , and the image by the mixed video signal S ₂ is, as shown in FIG.
It will be displayed on the viewfinder 43.

The system controller 5 is connected to an operation panel 70 arranged in the housing of the transmitter / receiver 1, and the operation panel 70 has an initialization button 71, a servo on / off button 72, whose operation will be described later, And a cursor button 73 is arranged.

The housing of the transmitter / receiver 1 is provided with a knob 74 for moving the entire optical system in the transmitter / receiver 1 by a predetermined amount in a horizontal direction and a knob 75 for moving a predetermined amount in the vertical direction through a moving mechanism (not shown). Has been.

Next, the operation of the above embodiment will be described.

First, before starting transmission / reception of signals by the light beams L ₁₁ and L 12 between the transmitter / receiver 1 and the transmitter / receiver 2, the optical axis 15 of the transmitter / receiver 1 is directed toward the transmitter / receiver 2. Then, the transmitter / receiver 1 is installed and fixed at an appropriate position.

Next, the power switch (not shown) of the transmitter / receiver 1 is turned on and the initialization button 71 on the operation panel 70 is pressed to push the axis 20 through the system controller 5, the servo circuit 24 and the motors 22 and 23. And the shaft 21 is brought into the central rotation position. In this state, the optical axis 15 is adjusted in advance so as to accurately face the front direction of the lens 14 for transmitting and receiving light.

FIG. 4 shows an image display example on the viewfinder 43 at this time. As can be seen from FIG. 4, the image on the viewfinder 43 shows an outgoing light beam point image 60 corresponding to the light spot by the extracted light beam L ₁₂ , a transceiver image 62 corresponding to the transceiver 2, and the surrounding scene. , Cursors 63, 64, a display 65 indicating the stability of the x-direction servo operation on the position sensor 25 (hereinafter referred to as x-direction servo stability display) and a display 66 indicating the stability of the y-direction servo operation ( Hereinafter, a y-direction servo stability display) will be a composite image.

Here, as the x-direction servo stability indicator 65, a light spot La formed by condensing the light beam L ₂₄ on the position sensor 25 is any servo range A1 on the position detecting element 53 shown in FIG. Depending on whether or not it is in A3, when it is in the servo range A1 with a margin of extremely high stability, the central portion 65A shown by the hatched portion in FIG. 4 emits green light. Further, when the servo range A2 has a relatively large margin of stability, either the outer portion 65B or the outer portion 65C indicated by a halftone dot portion is located depending on the position of the light spot La in the x direction. Emits yellow light. Further, when it is in the servo range A3 where the margin of stability is small, the light spot L
Depending on the position of a in the x direction, either the outermost portion 65D or the outermost portion 65E indicated by the hatched portion in the opposite direction emits red light. It should be noted that this red display may not be a continuous display, but may be a blinking display under the control of the system controller 5 by operating an operation button (not shown) on the operation panel 70. The y-direction servo stability display 66 is also the same as the x-direction servo stability display 65.

In the state shown in FIG. 4, since the emitted light beam point image 60 and the transmitter / receiver image 62 are separated from each other, they are completely out of the servo range, and all of green, yellow and red are emitted. Instead, only the frames of the x-direction and y-direction servo stability displays 65 and 66 are displayed. In such a state, the system controller 5
Based on the output signal of, for example, "Out of servo range. Turn the position adjustment knobs 74 and 75 to superimpose the emitted light beam point image 60 and the transmission / reception device image 62" is displayed.

In this case, first, by operating the cursor button 73 on the operation panel 70, the cursors 63 and 64 are aligned with the emitted light beam point image 60, and then, FIG.
As shown in FIG. 7, the position adjustment knobs 74 and 7 are arranged so that the emitted light beam point image 60 moves in the direction of arrow R indicated by the chain double-dashed line.
5 is turned (in this example, the knob 74 is turned clockwise and the knob 75 is turned counterclockwise corresponding to the display on the viewfinder 43). Then, the cursors 63 and 64 and the emitted light beam point image 60 move together, and the transmitter / receiver device image 62 moves so as to approach them. It should be noted that the cursors 63 and 64 are moved after being aligned with the emitted light beam point image 60 because the emitted light beam point image 60 is difficult to see when the image in the viewfinder 43 is bright. This is so that they can move without losing sight.

Then, as shown in FIG. 5, when the images of the emitted light beam point image 60 and the transmitter / receiver device image 62 substantially overlap with each other, in other words, the optical axes of the light beam L ₁₁ and the light beam L ₂₁ substantially coincide with each other. In this state, the servo on / off button 72 on the operation panel 70 is pressed to turn on the servo operation. Then, the light beam L ₁₁ supplied from the transmission / reception device 2
In accordance with the position of the light spot La of the light beam L ₂₄ incident on the position sensor 25, the servo stability indications 65 and 66 in the x direction and the y direction are made as described above, and the servo operation causes the x direction to be displayed. The central portion 65A of the servo stability display 65 and the y-direction servo stability display 66
Also, confirm that both the central portion 66A and the central portion 66A are displayed in green.

If the green display is not obtained, the light emitting color and the position of the x-direction servo stability display 65 and the y-direction servo stability display 66 are confirmed, whereby the position adjusting knobs 74 and 75 are displayed. Can be displayed in green by rotating in a predetermined direction.

In this state, after pressing the servo on / off button 72 again to turn off the servo operation, in other words, after releasing the servo operation within the servo range with a margin in the operation point and fixing the servo operation point, By starting mutual transmission by the light beams L ₂₁ and L ₂₂ with the transmitting / receiving apparatus 2, mutual transmission can be performed with stable operation between the transmitting / receiving apparatus 1 and the transmitting / receiving apparatus 2.

During the mutual transmission, if the servo stability indications 65 and 66 change to yellow or red, for example, the optical axes of the transmission / reception device 1 and the transmission / reception device 2 are aligned again by looking at the time. The operation (the operation of turning the position adjusting knobs 74 and 75) may be performed.

The cursors 63 and 64 are set so as to cross the transceiver image 62, and the cursors 63 and 64 are set.
Are set so as to traverse the emitted light beam point image 60, and the coordinates of those points are read and stored to obtain the coordinates of those set points, and the transmitter / receiver 2 of the optical axis 15 is obtained from the coordinates.
Since the amount of deviation with respect to is quantitatively determined by the system controller 5, the direction of the optical system of the transmitter / receiver 1 is automatically corrected according to the amount of deviation (the knobs 74 and 75 for position adjustment are automatically adjusted). You can also change the configuration (to be equivalent to turning).

As described above, according to the above embodiment, the viewfinder 43 displays the emitted light beam point image 60, the transmission / reception device image 62, and the surrounding scene of the transmission / reception device 2 as an image, and the servo control is performed. Since the image showing the operation stability is displayed as the x-direction and y-direction servo stability displays 65 and 66, the optical axes of the outgoing light beam L ₁₁ and the incoming light beam L ₂₁ can be easily observed while observing the viewfinder 43. It is possible to cancel the servo operation within a servo range where the operating point has a margin and fix the servo operating point, and start transmission in a short time between the transmitter / receivers 1 and 2. In addition to the above, transmission can be performed at a stable operating point.

The present invention is not limited to the above-mentioned embodiments, and it goes without saying that various configurations can be adopted without departing from the gist of the present invention.

[0051]

As described above, according to the optical space transmission apparatus of the present invention, the operating point of the servo operation is displayed on the display means, so that the servo operation can be performed in the servo range where the operating point has a margin. By releasing and fixing the operating point, it is possible to achieve stable mutual transmission between one transmission / reception device and another transmission / reception device.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of an embodiment of an optical free space transmission apparatus according to the present invention.

FIG. 2 is a front view showing the configuration of a position sensor in the optical free space transmission apparatus shown in FIG.

FIG. 3 is a diagram provided for explaining a servo range assigned to a position detection element of the position sensor shown in FIG.

FIG. 4 is a diagram showing an image on a viewfinder in the optical space transmission apparatus shown in FIG.

5 is a diagram showing an image on a viewfinder in a state where the optical axes match in the optical space transmission apparatus shown in FIG. 1. FIG.

[Explanation of symbols]

 1, 2 Transmitter / receiver 11, 12 Mirror 25 Position sensor 43 Viewfinder 65 x direction servo stability display 66 y direction servo stability display

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location H04N 7/22 8943-5C

Claims (1)

[Claims] 1. A light beam sent from another transmitter / receiver is detected by a light beam position detecting means through an optical axis adjusting means arranged in one transmitter / receiver, and the optical axis adjusting means is detected according to the detected output. In the optical space transmission device adapted to adjust the servo operation by means of a servo operation, a display means is provided in the one transmitting / receiving device, and the operating point of the servo operation based on the detection output of the light beam position detecting means is provided on the display means. The optical space transmission device is characterized by displaying.