JP4029402B2 - Optical axis adjustment device for optical wireless transmission device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an optical axis adjustment device for an optical wireless transmission device that performs optical wireless transmission with an optical axis of an optical signal transmitted by a transmitter directed toward a receiver.
[0002]
[Prior art]
Conventionally, there is an optical wireless transmission technology that performs spatial transmission of information using light. In general, infrared light is used for the optical wireless transmission, and a semiconductor light emitting element such as a light emitting diode or a laser diode is used as the light emitting element. In such optical wireless transmission, when it is desired to provide a sufficient distance between transmission and reception, it is necessary to narrow the output angle of the light beam emitted from the transmission device sharply, that is, to narrow it so that a signal with a sufficient light level is incident on the reception device side. Therefore, the optical axes of the transmission device and the reception device must be aligned. Therefore, alignment of the optical axis of the optical wireless transmission apparatus is a very troublesome operation because a light beam having a narrow emission angle is used or infrared light whose light beam is invisible is used. Therefore, conventionally, there has been proposed an optical wireless transmission apparatus that can easily perform this optical axis alignment.
[0003]
As an example, Patent Document 1 below discloses that the visible light from the transmission device is focused on the same optical axis as the signal transmission infrared light or parallel optical axis and sent together to the reception device side. An optical wireless transmission device is disclosed in which an operator adjusts the optical axis of a transmission device while observing visible light reflected by the visible light reflection means and being applied to the provided visible light reflection means. As another technique, an optical sight transmitter is installed in the transmitter and the optical axis is adjusted while looking at the sight, or a measuring device for detecting the received light level is connected to the receiver side. There is also an optical wireless transmission device that performs optical axis alignment in one set. In addition, as disclosed in Patent Document 2 below, there is a type that uses a light source for adjusting the optical axis on the receiver side to fold back the reception level information of the transmission light from the transmitter and adjust the optical axis accordingly. .
[0004]
[Patent Document 1]
JP-A-62-110339 [Patent Document 2]
Japanese Patent Laid-Open No. 7-131422
[Problems to be solved by the invention]
However, the optical wireless transmission device as disclosed in the above-described Patent Document 1 requires a configuration that causes the transmission device to generate visible light used for purposes other than optical wireless transmission. In addition, when it is desired to keep a sufficient distance between the transmitting and receiving devices, the visible light emission output must be made sufficiently large, and it is necessary to add the configuration, thereby increasing the cost of the transmitting device. In addition, the device becomes large. This is the same when a sighting machine is installed in the transmission device.
[0006]
Further, it is necessary to strictly match the optical axis of visible light, the aim of the sighting device, and the optical axis of infrared light for signal transmission. In addition, even when the measurement device for detecting the received light level is connected to the receiving device and the measurement is performed by one person, there are disadvantages such as the need to prepare the measured device for detecting the received light level and the need for manpower. As described above, when the conventional optical wireless transmission device attempts to simplify the optical axis alignment, the cost of the transmission / reception device increases and the size of the transmission / reception device increases. Conversely, the cost of the transmission / reception device decreases and the size of the transmission / reception device decreases. As a result, there is a drawback that it takes time and effort to align the optical axis.
[0007]
In addition, the optical wireless transmission device disclosed in Patent Document 2 receives a detected optical signal in addition to the first optical transmission unit that transmits an optical signal having a narrow directivity angle for carrying information to be transmitted as described above. It has a means to send and receive reception information according to the level signal between transmission and reception, and by extracting the reception information on the transmission side, a simple optical axis alignment method is realized, but it is relatively expensive like a motor Besides using electrical drive means, there is a lack of proposals on how to optimally drive the optical axis. In addition, the optical axis alignment method using relatively expensive parts such as a stepping motor and a DC motor and using the light reception level information for these controls naturally increases the cost.
[0008]
In addition, the conventional optical axis alignment mechanism that does not use a motor is a mechanism that simply rotates the axis, and even if you release your hand when the optical axis is aligned, the position will not be determined. The axis was likely to shift again. Also, for fine adjustment, grasping the amount of movement relies on the human sense of operation, and even when using a level monitor, detailed operation of the fingertips is necessary, and the final optical axis alignment is necessary. Fine adjustment at the stage was not easy.
[0009]
As described above, the conventional optical axis alignment is a large-sized device, requires two people and requires manual operation, relies on relatively expensive driving means, or has a small fingertip operation. There was a problem that was required.
[0010]
Accordingly, the present invention has been made with the above points in mind, and provides an optical axis adjustment device for an optical wireless transmission device that can easily align the optical axis of optical wireless transmission with a simple configuration and operation. With the goal.
[0011]
[Means for Solving the Problems]
In order to achieve the above object, the present invention is such that the rotation angle unit of the rotation mechanism for manually aligning the optical axis with the other party is always within the field of view of the other party.
That is, according to the present invention, the optical transmitter includes an optical transmitter that transmits an optical signal, and a receiver that includes an optical receiver that receives the optical signal, and the optical transmitter and the optical receiver. In the optical axis adjustment device of the wireless transmission device for manually adjusting the optical axis between the optical communication partner,
A biaxial rotation mechanism for rotating the optical axis of the optical transmission means and / or the optical reception means in a predetermined angle unit in a horizontal direction X and a vertical direction Y;
If the angle at which transmission or reception is possible with respect to the other party is φ, and the rotation angle units in the horizontal direction X and vertical direction Y of the biaxial rotation mechanism are Δθx and Δθy, respectively,
Δθx ² + Δθy ² ≦ φ ²
An optical axis adjusting device for an optical wireless transmission device is provided.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of an optical wireless transmission apparatus using the optical axis alignment method of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a schematic configuration diagram showing an embodiment of an optical wireless transmission apparatus according to the present invention.
[0013]
As shown in FIG. 1, the optical wireless transmission apparatus according to the present invention includes a transmitter 1 and a receiver 2, and transmits a video signal from a video control unit 3 located away from the video display unit 4 to the video control unit 3 side. This is a system in which a transmitter 1 provided and a receiver 2 provided on the video display unit 4 side are optically wirelessly transmitted and displayed on the video display unit 4. The video signal is converted into an optical signal and output from the transmitter 1, and the output optical signal maintains a predetermined intensity within a certain radiation angle range B (−B / 2 to + B / 2). On the other hand, the receiver 2 has a received light directivity angle A (−A / 2 to + A / 2) that can be received by the light receiving element that receives the optical signal output from the transmitter 1. In order to realize optical transmission, the receiving light directivity angle at which the receiver 2 is captured within the range of the transmission light emission angle B of the optical signal on the transmitter 1 side and the light receiving element of the receiver 2 can receive the transmission light. It is necessary to capture the transmitter 1 within the range of A. Optical axis alignment in optical wireless transmission is to create the state as described above.
[0014]
FIG. 2 is a schematic configuration diagram of the transmitter 1 and the receiver 2 of the optical wireless transmission apparatus of the present invention. Each of the transmitter 1 and the receiver 2 is used for optical axis alignment as means for aligning the optical axis separately from the transmission light emitting element 11 and the transmission light receiving element 21 for transmitting and receiving an optical signal converted from a video signal. The light-emitting elements 12 and 22 and the plurality of light-receiving elements 13 and 23 are provided, and each other's light-emitting signal for optical axis alignment is received by the light-receiving means comprising the plurality of light-receiving elements 13 and 23, and the light reception level is detected and compared 3 is provided with a function of displaying the obtained signal on the optical axis adjustment direction display unit 30 for optical axis alignment as shown in FIG. At the time of optical axis alignment, a human (operator) adjusts the axes of the transmitter 1 and the receiver 2 while viewing this display information.
[0015]
FIG. 3 shows an example of the optical axis adjustment direction display unit 30 of the transmitter 1 and the receiver 2 of the optical wireless transmission apparatus according to the present invention. In the present invention, the optical axis adjustment direction display unit 30 is provided in the transmitter 1 and the receiver 2, but any form that can be confirmed while performing optical axis alignment may be used. Further, both the transmitter 1 and the receiver 2 have a biaxial rotation mechanism of a pan direction X having a rotation axis Op perpendicular to the installation surface and a tilt direction Y having a rotation axis Ot parallel to the installation surface.
[0016]
FIG. 4 is a diagram showing a state in which transmission light is output from the transmitter 1 of the optical wireless transmission apparatus of the present invention, and the receiver 2 is captured within the transmission light radiation angle B, and will be described with reference to FIG. The state of the transmission light radiation angle B is shown. FIG. 5 is a diagram illustrating a positional relationship between the spot S of the transmission light radiation angle B output from the transmission light and the receiver 2. When the rotation mechanism of the pan direction X and tilt direction Y of the transmitter 1 is manually operated according to the optical axis adjustment direction display unit 30 of the transmitter 1, each rotation angle unit (unit rotation) of the pan direction X and tilt direction Y When Δθx and Δθy are larger than the transmission light radiation angle B, the receiver 2 can be captured even if it is moved in either the pan or tilt directions as in the spot S of the transmission light radiation angle B in FIG. May occur. In such a case, since the optical axis cannot be adjusted unless the installation position of the transmitter 1 or the receiver 2 is moved delicately, the usability is very bad.
[0017]
In addition, when the pan / tilt rotation mechanism is not a mechanism capable of sequential movement and stationary by continuous rotation of a unit rotation angle as in the present invention, but a mechanism that rotates steplessly, fine adjustment at the final stage It is possible to rely on the human sense of operation, and a wide range where the optical axes match is sufficient. However, the more accurate the adjustment is, the more difficult the adjustment is.
[0018]
FIG. 6 is a diagram showing the relationship between the transmission light radiation angle B and the unit rotation angles Δθx and Δθy in the pan / tilt direction of the transmitter 1 according to the present invention, and the viewpoint direction is the same as FIG. As shown in FIG. 6, when the panning / tilting direction is rotated by the minimum movement unit, that is, the unit rotation angles Δθx and Δθy, there is no dead angle between the spots S of the transmission light radiation angle B at each position. If this is the case, the receiver 2 is always captured by the spot S at the transmission light radiation angle B. In order to eliminate the blind spot in this way, assuming that the radiation angle of the transmission light is B and the rotation angle units of the biaxial rotation mechanism that drives the optical transmission means are Δθx and Δθy,
Δθx ² + Δθy ² ≦ B ²
Should be satisfied. In the present embodiment, the unit rotation angles Δθx and Δθy in the pan / tilt direction are set to a half value of the transmission light radiation angle B in consideration of the mechanical error of the rotation mechanism and the influence of vibration.
[0019]
Since the rotation mechanism provided in the optical wireless transmission device according to the present invention can be manually rotated quantitatively based on the unit rotation angles Δθx and Δθy, once the optical axis is aligned and then shifted again by adjustment, By returning the unit rotation angles Δθx and Δθy that are rotated until the axis is shifted, the state where the optical axis is present can be quickly restored. In addition, by knowing how many times the unit rotation angles Δθx and Δθy have been rotated in the pan and tilt directions with the optical axes aligned, it is possible to obtain the most ideal state within the range where the optical axes are aligned. The same can be said for the transmitter 1 and the receiver 2.
[0020]
FIG. 7 is a diagram showing a state in which the transmission light output from the transmitter 1 of the optical wireless transmission apparatus of the present invention is captured within the reception light directivity angle A that can be received by the light receiving element 21 of the receiver 1. Further, FIG. 8 and FIG. 9 illustrate the viewpoint directions of the drawings representing the receivable received light directivity angle A spots described with reference to FIGS.
[0021]
FIG. 8 is a diagram showing the positional relationship between the spot S of the received light directivity angle A (see FIG. 7) and the transmitter 1 included in the light receiving element 21 of the receiver 2 of the optical wireless transmission apparatus of the present invention. According to the optical axis adjustment direction display unit 30 of the receiver 2, the rotation angle units Δθx and Δθy of the pan direction X and the tilt direction Y are received when the pan mechanism X and the tilt direction Y of the receiver 2 are manually operated. If it is larger than the light directivity angle A, there is a possibility that the transmitter 1 cannot be captured even if it is moved in either the pan or tilt direction, as in the spot S of the reception light directivity angle A in FIG. In such a case, since the optical axis cannot be adjusted unless the installation position of the transmitter 1 or the receiver 2 is moved delicately, the usability is very bad.
[0022]
FIG. 9 is a diagram showing the relationship between the received light directivity angle A and the unit rotation angles Δθx and Δθy in the pan / tilt direction of the receiver 2 of the optical wireless transmission apparatus of the present invention, and the direction of the viewpoint is the same as FIG. is there. As shown in FIG. 9, when the panning / tilting direction is rotated by the minimum movement unit, that is, the unit rotation angles Δθx and Δθy, it is set so that there is no blind spot between the spots S of the received light directivity angle A at each position. The spot S at the reception light directivity angle A is always captured by the transmitter 1. In order to eliminate the blind spot in this way, if the reception light directivity angle is A and the rotation angle units of the biaxial rotation mechanism that drives the light receiving means are Δθx and Δθy,
Δθx ² + Δθy ² ≦ A ²
Should be satisfied. In the present embodiment, the unit rotation angles Δθx and Δθy in the pan / tilt direction are set to half the received light directivity angle A in consideration of the mechanical error of the rotation mechanism and the influence of vibration.
[0023]
FIG. 10 is a schematic diagram of a pan / tilt rotation mechanism of the receiver 2 of the optical wireless transmission apparatus of the present invention. The structure of the pan / tilt rotation mechanism is the same as that of the transmitter 1. The rotation mechanism 40 in the pan direction X is in the base portion 42 that supports the movable portion 41 on which the light receiving element 21 is mounted via the arm portion 44, and the rotation mechanism 43 in the tilt direction Y is in the movable portion 41. The rotation in the pan direction X may be performed by rotating a rotor 50 described later with a finger or by directly rotating the movable portion 41. The rotation in the tilt direction Y turns the movable part 41 directly.
[0024]
FIG. 11 is a diagram showing the rotor 50 and the latch portions 51 to 54 which are the rotation mechanism 40 in the pan direction X shown in FIG. The structure constituted by the rotor 50 and the latch portions 51 to 54 is the same in the pan direction X and the tilt direction Y. The rotor 50 and the latch portions 51 to 54 are resin parts. The rotor 50 is fixed to the movable part 41 on which the light receiving element 21 is mounted, while the latch parts 51 to 54 are fixed to the base part 42. The number of recesses 55 formed inside the rotor 50 is determined by a desired rotation angle unit Δθx, and in this embodiment, 100 recesses 55 are formed. The four latch portions 51 to 54 are urged by the elasticity of the resin in the recesses 55 formed inside the rotor 50, so that the rotor 50 can be stationary and fixed.
[0025]
When the rotor 50 rotates in any direction (± X), the latch portions 51 to 54 are separated from the energized concave portions 55 by the elasticity of the resin, and when the rotor 50 is further rotated, the new concave portions 55 that have moved are moved. Fit and repeat. In the present embodiment, the latch part 51 and the latch part 53, and the latch part 52 and the latch part 54 are in symmetrical positions with respect to the rotation center Op, and the resin spring that gives the resin part elasticity to the latch part 51 and the latch part 53. Are functionally symmetric with respect to the line a. Similarly, the functional shape of the resin spring that gives resin elasticity to the latch portion 52 and the latch portion 54 is also symmetrical with respect to the line b.
[0026]
Since the form of the resin spring portion is determined as described above, each latch portion according to the rotation direction of the rotor 50 is formed by a rotation mechanism constituted by an integral part of the rotor 50 and the latch parts 51 to 54 and three parts of the rotation shaft Op. The difference in feel of 51 to 54 can be offset, and a uniform operation feeling independent of the rotation direction can be obtained. Moreover, since each latch part 51-54 is arrange | positioned in the symmetrical position with respect to the rotating shaft Op, the rotor 50 can be made still in a stable state with good balance.
[0027]
【The invention's effect】
As described above, according to the present invention, since the rotation angle unit of the rotation mechanism for manually aligning the optical axis with the other party is always within the field of view of the other party, the optical wireless transmission device can be simply configured and operated. Can be easily aligned.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram showing an embodiment of an optical wireless transmission apparatus of the present invention.
FIG. 2 is a schematic configuration diagram of a transmitter and a receiver of the optical wireless transmission apparatus of the present invention.
FIG. 3 is a block diagram showing an optical axis alignment information display section of the transmitter and receiver of the optical wireless transmission apparatus of the present invention.
FIG. 4 is an explanatory diagram showing a state where a receiver is caught within a transmission light emission angle of the optical wireless transmission device of the present invention.
FIG. 5 is an explanatory diagram showing a positional relationship between a spot of a transmission light radiation angle and a receiver of the optical wireless transmission apparatus of the present invention.
FIG. 6 is a diagram illustrating a relationship between a transmission light emission angle of a transmitter of an optical wireless transmission apparatus according to the present invention and a unit rotation angle in a pan / tilt direction.
FIG. 7 is an explanatory diagram showing a state where a transmitter is caught within the reception light directivity angle of the optical wireless transmission device of the present invention.
FIG. 8 is an explanatory diagram showing a positional relationship between a spot of a received light directivity angle and a transmitter of an optical wireless transmission apparatus according to the present invention.
FIG. 9 is a diagram showing the relationship between the received light directivity angle of the receiver of the optical wireless transmission apparatus of the present invention and the unit rotation angle in the pan / tilt direction.
FIG. 10 is a schematic view of a pan / tilt rotation mechanism of the receiver of the optical wireless transmission apparatus of the present invention.
FIG. 11 is a schematic view of a pan direction rotation mechanism mounted on the receiver of the optical wireless transmission apparatus of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Transmitter 2 Receiver 3 Image | video control part 4 Image | video display part 11, 12, 22 Light emitting element (transmission light light emitting element)
13, 21, 23 Light receiving element (transmitting light receiving element)
30 Optical axis adjustment direction display part 40 Pan direction rotation mechanism 41 Movable part 42 Base part 43 Tilt direction rotation mechanism 44 Arm part 50 Rotors 51 to 54 Latch part 55 Recessed part

Claims (2)

A transmitter having an optical transmission means for transmitting an optical signal; and a receiver having an optical reception means for receiving the optical signal, wherein the optical axis between the optical transmission means and the optical reception means is optical In the optical axis adjustment device of the wireless transmission device that is manually adjusted to the communication partner,
A biaxial rotation mechanism for rotating the optical axis of the optical transmission means and / or the optical reception means in a predetermined angle unit in a horizontal direction X and a vertical direction Y;
If the angle at which transmission or reception is possible with respect to the other party is φ, and the rotation angle units in the horizontal direction X and vertical direction Y of the biaxial rotation mechanism are Δθx and Δθy, respectively,
Δθx ² + Δθy ² ≦ φ ²
An optical axis adjusting device for an optical wireless transmission device. The one-axis rotation mechanism of the rotation mechanism is
A plurality of latches fixed so as to be symmetric about the rotation axis;
A rotor capable of rotating around the rotation axis;
2. The optical wireless transmission according to claim 1, wherein the plurality of latch portions can be engaged with the rotor, and concave portions having a pitch corresponding to the rotation angle units Δθx and Δθy are formed. The optical axis adjustment device of the device.

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