JP2004274738A - Collimation device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To simplify collimation in the case of manually carrying out the optical axis adjustment in an optical wireless transmission system. <P>SOLUTION: LEDs 22 to 25 are selectively lighted (or turned off) in response to a level difference of levels in vertical and horizontal directions to indicate positional deviations in light transmitted from a communication opposite party in the vertical and horizontal directions with respect to the optical axis. A communication enable state display LED 28 is turned off (or lighted) when the absolute value of the level difference of each level in the vertical and horizontal directions is a prescribed level or below to indicate that the positional deviation in the vertical and horizontal directions is within a prescribed permissible range. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

  The present invention relates to an optical axis adjustment device for an optical wireless transmission system.

  In an optical wireless system, data is transmitted by transmitting infrared light modulated according to a data signal from a light emitting device, and receiving and demodulating the light with a light receiving device. In order to increase the transmission speed, it is necessary to obtain a sufficient amount of light with a photodetector. To this end, it is necessary to narrow the directional angle of the transmission light from the light emitter and increase the light intensity. In this case, it is necessary to adjust the optical axes of the light receiver and the light emitter.

  In a conventional optical wireless system, an adjustment method using pilot light has been adopted for optical axis adjustment. FIG. 9 shows a configuration example of a system using the optical axis adjustment method. The terminal 1 (master unit) includes a data light emitting unit 3 that emits light (data light) for data transmission, and an optical signal (pilot) having a wide directivity angle different in frequency from the data light transmitted from the data light emitting unit 3. A pilot light emitting unit 4 for transmitting light) and a data light receiving unit 5 for receiving data light from the terminal 2 (child device) are provided.

  The terminal 2 (slave) is provided with a light emitting unit 6 and a light receiving unit 7 having a structure that can be automatically rotated in the horizontal and vertical directions. The terminal 2 receives the pilot light transmitted from the pilot light emitting unit 4 of the terminal 1 at the light receiving unit 7 while rotating the light emitting unit 6 and the light receiving unit 7 integrally in the horizontal and vertical directions, and the light receiving level is maximized. The optical axis is adjusted by stopping at a certain position. In this configuration example, the terminal 2 receives both the pilot light and the data light by the light receiving unit 7. However, a configuration in which the pilot light and the data light are received by different light receiving units may be considered.

  In the light receiving unit 7 of the terminal 2, as shown in FIG. 10, a quadrant PD 8 divided into 2 × 2 quadrants in the horizontal and vertical directions with respect to the pilot light is used as a light receiving element. In this element, four PDs (PD_A to PD_D) are arranged in a 2 × 2 array in one package, and a current obtained by photoelectric conversion from each PD can be detected. FIG. 11 shows an example of a block diagram of a circuit for realizing this conventional example, and FIG. 12 shows an example of a flowchart. The light receiving section 7 of the terminal 2 receives the pilot light from the terminal 1 by the four-divided PD 8, detects currents from the respective PD_A to PD_D, converts each signal into a voltage, and amplifies the signal (Dir_A to Dir_D).

  The control unit 9 of the terminal 2 controls the switch 12 by the microcomputer 11 in steps S1 to S3 shown in FIG. 12 to sequentially select and output the signals Dir_A to D, and detects the level of the amplified signal amplitude as a DC value. Input to the microcomputer 11. In step S4 and subsequent steps, the microcomputer 11 compares the received light signal levels of the sequentially input PD_A to PD_D, and obtains the tilt (vertical) motor 13 of the motor unit 10 so that the PD_A to PD_D receive the same amount of received light. And the pan (horizontal) motor 14 is operated.

An example of a procedure for comparing the light reception signal levels in step S4 and subsequent steps is as follows.
(1) The sum of the light receiving levels of PD_A and PD_D is compared with the sum of the light receiving levels of PD_B and PD_C (step S5).
(2) If the sum of PD_A and PD_D is equal to the sum of PD_B and PD_C, it is considered that the center of the quadrant PD8 is irradiated with pilot light in the tilt direction (steps S5 → S9).
(3) If the sum of PD_A and PD_D is larger than the sum of PD_B and PD_C, it is considered that the pilot light is irradiated above the quadrant PD8, and the tilt motor 13 is moved to turn the quadrant PD8 upward (step). S6 → S7).
(4) If the sum of PD_A and PD_D is smaller than the sum of PD_B and PD_C, it is considered that the pilot light is irradiated to the lower side of the quadrant PD8, and the tilt motor 13 is moved to turn the quadrant PD8 downward ( Step S6 → S8).
(5) The above procedures (2) to (4) are repeated so that the pilot light is applied to the center in the vertical direction of the quadrant PD 8.
(6) Similarly, adjustment in the pan (horizontal) direction is performed. If the sum of the light receiving levels of PD_A and PD_B is not equal to the sum of the light receiving levels of PD_C and PD_D, they are compared (step S9 → S10). If the sum of PD_A and PD_B is equal to the sum of PD_C and PD_D, it is considered that the center of the quadrant PD8 is irradiated with pilot light in the pan (horizontal) direction (step S9 → end of processing).
(7) If the sum of PD_A and PD_B is larger than the sum of PD_C and PD_D, it is considered that pilot light is irradiated on the right side of the quadrant PD8, and the pan motor 14 is moved to turn the quadrant PD8 rightward (step). S10 → S11).
(8) If the sum of PD_A and PD_B is smaller than the sum of PD_C and PD_D, it is considered that the pilot light is irradiated on the left side of the quadrant PD8, and the pan motor 14 is moved to turn the quadrant PD8 leftward (step). S10 → S12).
(9) The above procedures (6) to (8) are repeated so that the pilot light is applied to the center in the horizontal direction of the quadrant PD 8.

In the above conventional example, the above-mentioned optical axis adjustment method is used so that the user can easily install the optical axis.
Since the optical axis adjustment was performed automatically, peripheral circuits and microcomputers for automatically moving mechanical parts such as motors and gears were required, resulting in large-scale and expensive terminals.

Therefore, as a conventional example in which the optical axis adjustment is performed manually instead of automatically, there is a method of detecting and displaying the level of light transmitted from a communication partner, for example, as described in Patent Document 1 below. Another conventional method of notifying the reception level by display or volume is used when the direction of the receiving antenna of the television receiver is adjusted with respect to the transmitting antenna of the broadcasting station.
JP-A-7-131422

  However, as disclosed in Patent Document 1, the reception level is simply reported by display or volume. Therefore, the user does not know the adjustment direction of the optical axis alignment even when looking at the display level, and seeks up, down, left, and right in the dark. Since the optical axis needs to be rotated and the adjustment is not easily completed, there is a problem that the adjustment operation is troublesome.

  The present invention has been made in view of the above-described problems of the related art, and when performing optical axis adjustment, it is possible to easily recognize whether or not the optical axis is displaced in the vertical and horizontal directions, thereby simplifying the optical axis adjustment work. It is an object of the present invention to provide an optical axis adjustment device of an optical wireless transmission system that can be used.

The present invention provides the following apparatus to achieve the above object.
[1] In an optical axis adjusting device used for an optical wireless transmission system,
A light receiver having a light receiving surface rotatable in up, down, left, and right directions, comprising a plurality of light receiving elements arranged on the light receiving surface in up, down, left, and right directions, and receiving an optical signal transmitted from a communication partner by optical wireless communication When,
Detecting means for detecting each level of the optical signal received by the plurality of light receiving elements,
A plurality of display elements for position shift display arranged in up, down, left and right directions respectively corresponding to each of the plurality of light receiving elements,
Depending on whether the absolute value of the level difference of each level detected by the detection means is larger or smaller than a predetermined value, the switching between the lighting and non-lighting of the plurality of display elements for displaying the position shift is selectively performed. A control unit for controlling whether or not the positional deviation of the optical axis of the optical signal in the vertical and horizontal directions is within a predetermined allowable range.
[2] a display element for communicable display that is independent of the plurality of display elements for displaying the displacement;
The control device according to [1], wherein the control unit controls to turn on the display element for communicable display when the absolute value of the level difference between the levels detected by the detection unit is smaller than a predetermined value. Optical axis adjustment device.
[3] Each of the plurality of display elements for the displacement display is divided into a plurality of segments,
The control unit according to [1], wherein the control unit switches between lighting and non-lighting of the plurality of segments in a stepwise manner in accordance with an absolute value of a level difference between the levels detected by the detection unit. Optical axis adjustment device.
[4] In an optical axis adjusting device used for an optical wireless transmission system,
A light receiver having a light receiving surface rotatable in up, down, left, and right directions, comprising a plurality of light receiving elements arranged on the light receiving surface in up, down, left, and right directions, and receiving an optical signal transmitted from a communication partner by optical wireless communication When,
Detecting means for detecting each level of the optical signal received by the plurality of light receiving elements,
A plurality of display elements for position shift display arranged in up, down, left and right directions respectively corresponding to each of the plurality of light receiving elements,
By selectively switching between lighting and non-lighting of the plurality of display elements for displaying the positional deviation according to the level difference between the levels detected by the detecting means, the vertical and horizontal directions of the optical axis of the optical signal An optical axis adjusting device, comprising: a control unit configured to display whether or not there is a positional deviation.
[5] a display element for communicable display which is independent of the plurality of display elements for displaying the displacement,
The optical axis adjusting device according to [4], wherein the control unit controls to turn on the display element for the communicable display when there is no level difference between the levels detected by the detection unit. .

  As described above, according to the present invention, positional deviation in the vertical and horizontal directions is detected and displayed, so that it is possible to easily recognize whether there is a positional deviation in the vertical and horizontal directions of the optical axis, The adjustment work of the optical axis can be simplified.

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

<First embodiment>
FIG. 1 is a perspective view showing a main part configuration of a first embodiment of an optical axis adjusting device according to the present invention, and FIG. 2 is a configuration diagram comprising a top view and a side view showing a light receiving / emitting unit in FIG. 1 in detail. 3 is a block diagram showing the overall configuration of the first embodiment of the optical axis adjusting device according to the present invention, FIG. 4 is a flowchart for explaining the optical axis adjustment of the optical axis adjusting device in FIG. 3, and FIG. It is explanatory drawing which shows the optical axis adjustment of the optical axis adjustment apparatus of No. 3.

  In FIG. 1, the terminal 15 is provided with a mechanism that can freely rotate the light emitting / receiving unit 16 in the horizontal and vertical directions manually. In this mechanism, the light emitting / receiving unit 16 is manually rotatable in the vertical direction with respect to the base 16a, and the base 16a is manually rotatable in the horizontal direction with respect to the terminal 15. At a position visible to the user on the base 16a, a direction indication LED (hereinafter, also simply referred to as an LED) 18 for instructing the user in four horizontal and vertical rotation directions is provided. I have.

  FIG. 2 is a configuration diagram including a top view and a side view showing the configuration of the light receiving / emitting unit 16 in detail. A four-divided PD 17 (and light receiving lens 17a) arranged two-dimensionally in 2 × 2 to receive pilot light from the destination terminal on the substrate 16b, and for emitting transmission data light to the destination terminal The light emitting element 16c (and the light emitting lens 16d) is provided. In this configuration example, the terminal 15 receives both the pilot light and the data light by the 4-split PD 17, but a configuration in which the pilot light and the data light are received by different light receiving units, respectively, is also conceivable. The four-divided PD 17 is arranged to be rotated by 45 degrees [deg] with respect to the conventional arrangement arranged in a two-dimensional manner of 2 × 2 in the horizontal and vertical directions. That is, the arrangement direction of the four-divided PDs 17 coincides with the rotation direction of the light receiving / emitting unit 16, and PD_A = upper, PD_B = right, PD_C = lower, and PD_D = left. Further, in this example, the direction display LEDs 18 indicating the up, down, left, and right rotation directions are configured in an arrow shape as shown in FIG.

  In FIG. 3, the four-divided PD 17 of the light receiving unit 19 receives pilot light from another terminal, detects current from each of PD_A to PD_D, converts each signal into a voltage, and amplifies the signal in FIG. It has almost the same configuration as the automatic adjustment circuit. The control unit 20 of the terminal 15 does not switch the amplified signal with a switch, but further amplifies and detects the level in steps S11 to S13 shown in FIG. , 27, the user is instructed by the direction display LEDs 18 (22 to 25) of the display unit 21 in the direction in which the light emitting / receiving unit 16 is to be moved.

The procedure for manual adjustment so that the same amount of received light is obtained for each of PD_A to PD_D in step S14 and subsequent steps will be described below.
(1) The light receiving levels of PD_A and PD_C are compared (step S14).
(2) If the amount of light received by PD_A is larger than the amount of light received by PD_C, the output indicating “PD_A> PD_C” of the comparator 26 becomes “High”, and the LED 22 indicating upward is turned on (ON in step S15). Yes in S16 → S19, S20). The output indicating “PD_A <PD_C” becomes “Low”, and the LED 24 indicating the downward direction does not light.
(3) When the amount of received light of PD_C is larger than the amount of received light of PD_A, the output indicating “PD_A <PD_C” of the comparator 26 becomes “High”, and the LED 24 indicating the downward direction is turned on (No in step S16, S17, S18). . The output indicating “PD_A> PD_C” becomes “Low”, and the LED 22 indicating the upward direction does not light.
(4) When the received light amounts of PD_A and PD_C are equal, the outputs indicating “PD_A> PD_C” and “PD_A <PD_C” of the comparator are “Low”, and both the upper and lower LEDs 22 and 24 are not turned on (Yes in step S15). .
(5) The light receiving levels of PD_B and PD_D are compared (step S21).
(6) When the amount of light received by PD_B is larger than the amount of light received by PD_D, the output indicating “PD_B> PD_D” of the comparator 27 becomes “High”, and the LED 23 indicating the right direction is turned on (No in step S22 → Yes in step S23). → S24, S25). The output indicating “PD_B <PD_D” becomes “Low”, and the LED 25 indicating the left direction does not light.
(7) When the received light amount of PD_D is larger than the received light amount of PD_B, the output indicating PD_B <PD_D of the comparator 27 becomes “High”, and the LED 25 indicating the left direction is turned on (No → S26, S27 in step S23). The output indicating “PD_B> PD_D” becomes “Low”, and the LED 23 pointing right does not light up.
(8) When the light receiving amounts of PD_B and PD_D are equal, the outputs indicating “PD_B> PD_D” and “PD_B <PD_D” of the comparator are “Low”, and both the left and right LEDs 23 and 25 are not turned on (Yes in step S22). End).
(9) Therefore, as shown in FIG. 5, when the user manually turns the light emitting / receiving unit 16 in the horizontal and vertical directions according to the display of the LEDs 22 to 25, the light is received at a position where none of the LEDs 22 to 25 indicate the direction. The light emitting unit 16 can be fixed.

  With the above procedure, it is possible to easily recognize whether or not the optical axis is displaced in the vertical and horizontal directions, and the optical axis can be easily adjusted.

  In the present embodiment, the LEDs 22 to 25 are turned off when there is no displacement of the optical axis in the vertical and horizontal directions. Conversely, the LEDs 22 to 25 are turned on when there is no displacement of the optical axis in the vertical and horizontal directions. You may be comprised so that it may make it.

<Second embodiment>
In the second embodiment, in the state where the communicable light receiving level is obtained in the first embodiment, that is, when the optical axis is aligned, as shown in FIG. By disposing the display LED) at a position visible to the user, it becomes easier for the user to recognize that the optical axis adjustment has been completed, and it is easier for the user to recognize that the optical axis has shifted after the adjustment.

  That is, in the second embodiment, the LEDs 22 to 25 are selectively provided in accordance with the level difference when the absolute value of the level difference in each of the up, down, left, and right directions is larger than a predetermined value, as in the first embodiment. By illuminating, the positional shift of the light transmitted from the communication partner with respect to the optical axis in the up, down, left, and right directions is displayed. When the amounts are equal (that is, when the absolute value of the level difference in the up-down direction and the absolute value of the level difference in the left-right direction are both equal to or less than a predetermined value), the position is shifted in the up-down direction and the left-right direction. Indicates that it is within the allowable range.

<Third embodiment>
In addition, if there is a margin in the received light level with respect to the received light level required for communication, even if the pilot light is not received at the true center of the four-divided PD 17 but is received at a position close to the center, communication can be performed. It becomes possible. Therefore, in the LED indicating that the optical axes are aligned, the light receiving level difference between PD_A and PD_C (level difference in the vertical direction) and the light receiving level difference between PD_B and PD_D (level difference in the horizontal direction) are both within a certain range. Then, the circuit may be set so that the communication enabled display LED 28 is turned on. FIG. 7 shows an example of a circuit block diagram of the third embodiment.

Similarly to the circuit of the first embodiment, the four-divided PD 17 of the light receiving unit 19 receives pilot light from another terminal, detects current from each of PD_A to PD_D, converts each signal into a voltage, and amplifies the signal. Then, the control section 20 further amplifies each of the amplified signals to detect the level. The difference between the detected light receiving level in the vertical and horizontal directions is detected by a differential amplifier. The output of the differential amplifier when the light receiving level difference (Dir_A-Dir_C) in the vertical direction (vertical direction) and the light receiving level difference (Dir_B-Dir_D) in the horizontal direction (horizontal direction) is 0 is defined as Vsh [V]. If the difference is in the range of ± r [V], the procedure of adjustment when a communicable light receiving level is obtained is shown.
(1) When (Dir_A−Dir_C)> (Vsh + r) [V], that is, when the light receiving level of PD_A is larger than the light receiving level of PD_C by r [V] or more, the comparator 29 outputs “High” and the upward direction. Is turned on.
(2) When (Dir_A−Dir_C) <(Vsh−r) [V], that is, when the light receiving level of PD_A is smaller than the light receiving level of PD_C by r [V] or more, the comparator 30 outputs “High”; The LED 24 indicating the downward direction is turned on.
(3) If (Vsh-r) [V] ≦ (Dir_A−Dir_C) ≦ (Vsh + r) [V], that is, if the difference between the light receiving levels of PD_A and PD_C is not more than r [V], the comparators 29 and 30 “Low” is output, and the LEDs 22 and 24 are not turned on.
(4) When (Dir_B−Dir_D)> (Vsh + r) [V], that is, when the light receiving level of PD_B is higher than the light receiving level of PD_D by r [V] or more, the comparator 31 outputs “High” and moves rightward. Is turned on.
(5) When (Dir_B−Dir_D) <(Vsh−r) [V], that is, when the light receiving level of PD_B is smaller than the light receiving level of PD_D by r [V] or more, the comparator 32 outputs “High”; The LED 25 indicating the left direction is turned on.
(6) If (Vsh-r) [V] ≦ (Dir_B−Dir_D) ≦ (Vsh + r) [V], that is, if the difference between the light receiving levels of PD_B and PD_D is not more than r [V], the comparators 31 and 32 "Low" is output, and the LEDs 23 and 25 are not turned on.
(7) When (Vsh-r) [V] ≦ (Dir_A−Dir_C) ≦ (Vsh + r) [V] and (Vsh−r) [V] ≦ (Dir_B−Dir_D) ≦ (Vsh + r) [V] That is, if the difference between the received light levels of PD_A and PD_C and the difference between the received light levels of PD_B and PD_D are both equal to or less than r [V], the four-divided PD 17 receives the pilot light almost at the center and can receive light. Therefore, the communication enable display LED 28 indicating that communication is possible is turned on.

<Fourth embodiment>
In the fourth embodiment, as shown in FIG. 8, the light reception level difference between PD_A and PD_C and the light reception level difference between PD_B and PD_D are divided into a plurality of segments in more detail according to the magnitude of the difference. Displaying with the direction display LED (indicator) enables the user to further easily adjust the optical axis. The display of this indicator may be a multi-value digital display or an analog display. FIG. 16 shows an example of a circuit block diagram of the fourth embodiment.

Similarly to the circuits of the first, second, and third embodiments, the four-divided PD 17 of the light receiving unit 19 receives pilot light from another terminal, detects current from each of PD_A to PD_D, and outputs each signal. The voltage is converted into a voltage and amplified, and the control unit 20 further amplifies and level-detects the amplified signal. The difference between the detected light receiving level in the vertical and horizontal directions is detected by a differential amplifier. It is assumed that the output of the differential amplifier makes a transition as shown in the graph of FIG. 17 in response to the movement of the spot on the quadrant PD, and the light receiving level difference in the vertical direction (Dir_A-Dir_C) and the light receiving level difference in the horizontal direction ( When Dir_B-Dir_D) is 0, the output of the differential amplifier is Vsh [V], when the beam enters only PD_A or PD_C, the differential amplifier output is Vmax, and Vmax>Va>Vb> Vc The following describes the adjustment procedure when a light-receiving level at which communication is possible is obtained if the light-receiving level difference is in the range of ± Vc [V].
(1) When (Dir_A-Dir_C)> (Vsh + Va) [V], that is, when the light receiving level of PD_A is higher than the light receiving level of PD_C by Va [V] or more, comparators 33, 34, and 35 output “High”. Then, all the LEDs 22a, b, and c indicating the upward direction are turned on. The user looks at this display and moves the light emitting and receiving unit upward.
(2) (Vsh + Va) [V] ≧ (Dir_A−Dir_C)> (Vsh + Vb) [V], that is, the light receiving level of PD_A is larger than the light receiving level of PD_C by Vb [V] or more and Va [V] or less. In this case, the comparators 34 and 35 output "High", the LEDs 22b and c indicating the upward direction are turned on, and the LED 22a is not turned on. The user looks at this display and moves the light emitting and receiving unit upward.
(3) (Vsh + Vb) [V] ≧ (Dir_A−Dir_C)> (Vsh + Vc) [V], that is, the light receiving level of PD_A is larger than the light receiving level of PD_C by not less than Vc [V] and not more than Vb [V]. In this case, the comparator 35 outputs “High”, and only the LED 22c indicating the upward direction is turned on, and the LEDs 22a and 22b are not turned on. The user looks at this display and moves the light emitting and receiving unit upward.
(3) (Vsh + Vc) [V] ≧ (Dir_A−Dir_C) ≧ (Vsh−Vc) [V] That is, if the difference between the light receiving levels of PD_A and PD_C is Vc [V] or less, comparators 33, 34, and 35 , 36, 37, and 38 all output "Low", and the LEDs 22a, b, and c and the LEDs 24a, b, and c do not light. The user sees this display and knows that the vertical displacement of the optical axis has been adjusted within a predetermined allowable range.
(4) Conversely, (Vsh−Vc) [V] <(Dir_A−Dir_C) ≦ (Vsh−Vb) [V], that is, the light receiving level of PD_C is equal to or more than Vc [V] with respect to the light receiving level of PD_A, If Vb [V] or less, only the LED 24c indicating the downward direction is turned on when it is large, and (Vsh−Vb) <(Dir_A−Dir_C) ≦ (Vsh−Va) [V], that is, the light receiving level of PD_C is the light receiving level of PD_A. If Vb [V] or more and Va [V] or less, the LEDs 24b and 24c are turned on, and (Vsh-Va) <(Dir_A-Dir_C), that is, the light receiving level of PD_C is higher than the light receiving level of PD_A. When it is larger than Va [V], all the LEDs 24a, b and c indicating the downward direction are turned on.
(5) The adjustment is performed in the same manner in the horizontal direction.

  Although the block diagram in FIG. 16 illustrates the configuration using the electric circuit, the same processing may be performed by a processor such as a microcomputer.

<Fifth embodiment>
In the fifth embodiment, although not shown, in the first to fourth embodiments, four single PDs are arranged as light receiving elements in up, down, left, and right directions.

  Next, sixth and seventh embodiments will be described. In the sixth and seventh embodiments, the display of the positional deviation in the vertical and horizontal directions is displayed on the monitor of the connected device. In this case, for example, an on-screen signal generation unit to which the output signal of the control unit 20 shown in FIGS. 3 and 7 is supplied is provided in the optical receiver. In the on-screen signal generation unit, an arrow whose display state changes (arrows as shown in FIGS. 5 to 8) is displayed on the monitor according to the output signal of the control unit 20, similarly to the above-described embodiments. To generate an on-screen signal for The generated on-screen signal is supplied to the monitor, and the display of the positional shift in the vertical and horizontal directions is performed on the monitor. As in the second, third, and fourth embodiments, the communicable display may be displayed on the monitor together.

<Sixth Embodiment>
When a LAN is considered as an application of the optical wireless transmission system, and a device to which the optical wireless terminal (optical receiving device) 2a of the embodiment of the present invention is connected is a PC45, as shown in FIG. An indicator indicating the light receiving level of the optical axis, and information for adjusting the optical axis, such as information on the rotational directions of the upper, lower, left and right, and whether or not a communicable light receiving amount is obtained, though not shown. By showing, the user can adjust the optical axis of the optical wireless terminal 2a while watching the monitor of the PC 45, and can easily perform the optical axis adjustment manually.

<Seventh embodiment>
Consider video transmission as an application of the optical wireless transmission system. As shown in FIG. 14, a recording device such as a tuner or a VCR / VDR is a video supply side 46, a panel such as a plasma / liquid crystal is a video display side 47, and an optical transmission device 48 for transmitting data to the video supply side. The image display side is provided with an optical receiving device 49 according to the embodiment of the present invention which performs data reception, and transmits an image and an audio signal from the image supply side 46 to the image display side 47 by optical wireless.

  In this system, it is assumed that the optical axis of the optical receiver 49 is manually adjusted. Since the light receiving device 49 is connected to the image display side 47, that is, the monitor, an indicator indicating a light receiving level in each direction, and further, although not shown, information on rotation directions of up, down, left, and right, and communication is possible. Information for adjusting the optical axis, such as information as to whether or not a large amount of received light is obtained, is displayed on the monitor as shown in FIG. Accordingly, the user can adjust the optical axis of the optical receiver 49 while viewing the information for adjusting the optical axis displayed on the monitor, and can easily perform the optical axis adjustment manually.

<Eighth Embodiment>
In each of the above embodiments, the light receiving and emitting unit is rotated directly by the user by hand. However, the light receiving and emitting unit may be rotated by an actuator such as a motor. In other words, the user supplies an instruction signal for instructing the rotation direction with a remote controller or the like to the motor control unit while watching the information for optical axis adjustment displayed on the monitor, and according to the instruction signal, as shown in FIG. It is also possible to rotate the light receiving / emitting unit by rotating the motor. For example, considering the video transmission of the seventh embodiment as an application of the optical wireless system, a remote control receiver 50 is provided on the video display side 47 as shown in FIG. The remote control receiver 50 may be provided in the main body of the optical receiver 49. The user gives an instruction of the rotation direction by the remote controller 51 in accordance with the direction instruction displayed on the monitor. The light receiving / emitting unit of the light receiving device 49 is rotated by the instruction signal from the remote control 51 received by the remote control receiving unit 50 to adjust the optical axis. The remote controller may operate not only the optical wireless device including the optical transmitting device 48 and the optical receiving device 49 but also the video display system.

FIG. 1 is a perspective view showing a main configuration of an optical axis adjusting device according to a first embodiment of the present invention. FIG. 2 is a configuration diagram including a top view and a side view specifically illustrating a light receiving and emitting unit in FIG. 1. FIG. 1 is a block diagram illustrating an overall configuration of an optical axis adjusting device according to a first embodiment of the present invention. 4 is a flowchart for explaining optical axis adjustment of the optical axis adjustment device of FIG. 3. FIG. 4 is an explanatory diagram illustrating optical axis adjustment of the optical axis adjustment device in FIG. 3. FIG. 14 is an explanatory diagram illustrating optical axis adjustment according to the second embodiment. It is a block diagram showing the whole optical axis adjustment device composition of a 3rd embodiment. It is explanatory drawing which shows the optical axis adjustment of 4th Embodiment. FIG. 2 is a configuration diagram illustrating a conventional optical wireless system. It is an explanatory view showing an optical axis detection unit in a conventional optical wireless system. FIG. 11 is a block diagram illustrating the overall configuration of a conventional optical axis adjustment device. 9 is a flowchart for explaining conventional optical axis adjustment. It is explanatory drawing which shows the optical-axis adjustment of 6th Embodiment. It is explanatory drawing which shows the optical-axis adjustment of 7th Embodiment. It is explanatory drawing which shows the optical-axis adjustment of 8th Embodiment. It is a block diagram showing the whole optical axis adjustment device composition of a 4th embodiment. FIG. 14 is a diagram for explaining an operation according to the fourth embodiment.

Explanation of reference numerals

1 Optical wireless terminal (base unit)
2 Optical wireless terminal (child unit)
3 Data emitting part (master unit side)
4 Pilot light emitting unit (master unit side)
5 Data receiver (master unit side)
6 Light emitting unit (child unit side)
7 Light receiving unit (child unit side)
8 quadrant PD
Reference Signs List 9 control unit 10 motor unit 11 microcomputer 12 switch 13 tilt motor 14 pan motor 15 terminal 16 light receiving / emitting unit 16a base 16b substrate 16c light emitting element 16d light emitting lens 17 4-division PD
17a Light receiving lens 18 Direction display LED
19 light receiving section 20 control section 21 display section 22, 23, 24, 25 direction indication LED
22a-c Direction indicator LED
23a-c Direction indicator LED
24a-c Direction indicator LED
25a-c Direction indicator LED
26, 27, 29, 30, 31, 32 Comparator 28 Lighting visible LED (communicable indication LED)
33-44 Comparator 45 PC
46 video supply unit 47 video display unit 48 optical transmission device 49 optical reception device 50 remote control reception unit 51 remote control

Claims (5)

In an optical axis adjustment device used for an optical wireless transmission system,
A light receiver having a light receiving surface rotatable in up, down, left, and right directions, comprising a plurality of light receiving elements arranged on the light receiving surface in up, down, left, and right directions, and receiving an optical signal transmitted from a communication partner by optical wireless communication When,
Detecting means for detecting each level of the optical signal received by the plurality of light receiving elements,
A plurality of display elements for position shift display arranged in up, down, left and right directions respectively corresponding to each of the plurality of light receiving elements,
Depending on whether the absolute value of the level difference of each level detected by the detection means is larger or smaller than a predetermined value, the switching between the lighting and non-lighting of the plurality of display elements for displaying the position shift is selectively performed. A control unit for controlling whether or not the positional deviation of the optical axis of the optical signal in the vertical and horizontal directions is within a predetermined allowable range. A plurality of display elements for the displacement display, and a display element for communication possible display independent of,
2. The control unit according to claim 1, wherein the control unit controls to turn on the display element for the communication enabled display when an absolute value of a level difference between the levels detected by the detection unit is smaller than a predetermined value. Optical axis adjustment device. Each of the plurality of display elements for the displacement display is divided into a plurality of segments,
The light according to claim 1, wherein the control unit switches between lighting and non-lighting of the plurality of segments in a stepwise manner in accordance with an absolute value of a level difference between the levels detected by the detection unit. Axis adjustment device. In an optical axis adjustment device used for an optical wireless transmission system,
A light receiver having a light receiving surface rotatable in up, down, left, and right directions, comprising a plurality of light receiving elements arranged on the light receiving surface in up, down, left, and right directions, and receiving an optical signal transmitted from a communication partner by optical wireless communication When,
Detecting means for detecting each level of the optical signal received by the plurality of light receiving elements,
A plurality of display elements for position shift display arranged in up, down, left and right directions respectively corresponding to each of the plurality of light receiving elements,
By selectively switching between lighting and non-lighting of the plurality of display elements for displaying the positional deviation according to the level difference between the levels detected by the detecting means, the vertical and horizontal directions of the optical axis of the optical signal An optical axis adjusting device, comprising: a control unit configured to display whether or not there is a positional deviation. A plurality of display elements for the displacement display, and a display element for communication possible display independent of,
The optical axis adjustment device according to claim 4, wherein the control unit controls to turn on the display element for the communicable display when there is no level difference between the levels detected by the detection unit.

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