JP2005045763A - Optical radio transmission apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To manually align the optical axis of the transmission light of a transmitter side by an inexpensive, simple and small configuration. <P>SOLUTION: In a receiver 22, a reception level detecting circuit 18 detects the reception level of a signal received by a first optical receiving means 15, and transmits a signal corresponding to this result, e.g. by a voltage to a light-emitting driver 20. The receiving state of the first optical transmission signal transmitted from a transmitter 1 in the receiver is displayed for the transmitter by using a second optical signal by a second optical transmitting means 25. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an optical wireless transmission apparatus that performs optical wireless transmission by directing an optical axis of a directional optical signal transmitted from a transmitter toward a receiver.

  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.

As an example, Patent Document 1 below discloses that the level of an optical signal transmitted from a transmission device is detected on the reception device side, and the reception level information is transmitted on the pilot signal to the transmission device. Thus, a method has been proposed in which the received light level information is displayed on a monitor and the optical axis of the transmitted light is manually adjusted so as to maximize the received level.
JP-A-7-131422

  However, in the above conventional example, the receiving side is provided with means for modulating the reception level and transmitting to the transmitting side, and the transmitting side is provided with means for demodulating and monitoring the reception level information, which is expensive. is there.

  An object of the present invention is to provide an optical wireless transmission apparatus that can manually adjust the optical axis of transmission light on the transmission side with a low-cost, simple, and compact configuration in view of the problems of the conventional example.

  In order to achieve the above object, the present invention comprises only a light emitting means for emitting light at an intensity level corresponding to the reception level on the receiving side, and the transmitting side manually adjusts the optical axis according to this intensity level. is there.

That is, according to the present invention, a transmitter having first optical transmission means for transmitting an optical signal having directivity, and a receiver having first optical reception means for receiving the optical signal and converting it into an electrical signal. An optical wireless transmission device comprising:
The transmitter is
An optical axis adjustment mechanism for manually adjusting the optical axis of the first optical transmission means;
The receiver
A second optical transmitter that emits light at an intensity level corresponding to the level of the signal received by the first optical receiver;
An optical wireless transmission apparatus is provided in which the optical axis of the first optical transmission means is manually adjusted in accordance with the intensity level.

According to the invention, a transmitter having a first optical transmission means for transmitting an optical signal having directivity, and a receiver having a first optical reception means for receiving the optical signal and converting it into an electrical signal. An optical wireless transmission device comprising:
The transmitter is
An optical axis adjustment mechanism for manually aligning the optical axis of the first optical transmission means;
The receiver
A plurality of second optical receiving means arranged around the position of the first optical receiving means for receiving the optical signal;
A plurality of second optical transmitters arranged near each of the second plurality of optical receivers and emitting light at an intensity level corresponding to the level received by each of the second plurality of optical receivers; ,
An optical wireless transmission device is provided in which the optical axis of the first optical transmission means is manually aligned so that the intensity levels of the second plurality of optical transmission means are the same.

  According to the present invention, only the light emitting means that emits light at the intensity level corresponding to the reception level is provided on the reception side, and the optical axis is manually adjusted according to the intensity level on the transmission side. With this configuration, the optical axis of the transmission light on the transmission side can be manually adjusted.

<Embodiment 1>
A preferred embodiment 1 of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing Embodiment 1 of an optical wireless transmission apparatus according to the present invention.

  First, the transmitter 1 in the optical wireless transmission apparatus according to the first embodiment will be described. The transmitter 1 receives a signal (for example, a video signal) transmitted from an external data generation device not described here by the transmission signal processing circuit 2, converts the signal into a signal format to be transmitted by the transmitter 1, and the light emitting element. Transmitted to the driver 3 and transmitted by a first light transmitting means (for example, composed of an LED, an LD, a condenser lens, etc.) 4 having directivity and a relatively narrow emission angle of about 1 to 5 degrees. As a spatial transmission toward the receiver 22.

  Further, the transmitter 1 can easily set the optical axis of the first optical transmission unit 4 based on the second optical signal transmitted by the second optical transmission unit 25 mounted for adjusting the optical axis of the receiver 22. A pan rotation mechanism 26 and a tilt rotation mechanism 27 that can be manually adjusted to each other. Here, when manually moving the optical axis of the first optical transmission unit 4, the control unit 11 may output data for stably emitting light instead of a video signal based on information of a switch (not shown).

  Next, the receiver 22 in the optical wireless transmission apparatus will be described. The receiver 22 receives the first optical transmission signal spatially transmitted by the first optical transmission unit 4 of the transmitter 1 with a relatively wide incident angle of, for example, several tens of degrees. An external device (for example, constituted by a PD, an APD, and a condensing lens) that is received by 15 and electrically amplified by the light receiving circuit 16 is added, and is not described here by the received signal processing circuit 17 For example, the signal is converted to a signal to be transmitted to an image receiving device or the like, and the data is transmitted to the external device.

  The receiver 22 is also connected to the transmitter 1 by a second light transmitting means (for example, an LED or a lens added thereto) 25 to adjust the optical axis of the first light transmitting means 4 of the transmitter 1. A second optical transmission signal (generally referred to as pilot light or the like) is transmitted (emitted). Further, the reception level of the signal received by the first light receiving means 15 is detected by the reception level detection circuit 18, and a signal based on the result, for example, a voltage is sent to the light emitting element driver 20, whereby the second The reception state of the first optical transmission signal sent from the transmitter 1 at the receiver 22 is displayed on the transmitter 1 by using the second optical transmission signal by the optical transmission means 25.

  Next, an outline of the optical axis alignment method in the optical wireless transmission apparatus will be described. When optical transmission is performed indoors or the like, the distance between the transmitter 1 and the receiver 22 is about several tens of meters at most. First, the light receiving element of the first light receiving means 15 of the receiver 22 is, for example, a directivity angle Has a relatively low directivity of about several tens of degrees, and can be adjusted in the direction of the transmitter 1 by a scale. The transmitter 1 converts a video signal or the like into an optical signal and outputs a first optical signal. The receiver 22 receives this first optical signal, converts it into an electrical signal, outputs it as data such as a video signal to the outside, and detects the reception level of this first optical signal.

  A pilot signal indicating the reception level as information is recognized by an operator (not shown) of the transmitter 1. Then, by moving the pan rotation mechanism 26 and the tilt rotation mechanism 27 of the transmitter 1, the turning on / off of the pilot signal or the strength of the lighting level is recognized. Manually adjust to receiver 22.

<Embodiment 2>
Next, a preferred second embodiment of the present invention will be described in detail with reference to the accompanying drawings. FIG. 2 is a block diagram showing a second embodiment of the optical wireless transmission apparatus for realizing the manual optical axis alignment method of the present invention, and a transmitter 1 and a receiver constituting the optical wireless transmission apparatus of the present invention. 22 is a block diagram of each component.

  Since the configuration of the transmitter 1 is the same as that of the first embodiment, a description thereof will be omitted, and the receiver 22 will be described. The difference from the first embodiment is that, apart from the first light receiving means 15, the second light receiving means 23a to 23d, and the light receiving / light emitting circuits 24a to 24d and the second light receiving means 23a to 23d respectively. It has 2nd optical transmission means 25a-25d. The second optical receivers 23a to 23d can be installed at arbitrary positions, and the plurality of second optical transmitters 25a to 25d independently emit pilot light according to the level with respect to each of them. As shown in the figure, by providing at approximately four positions around the first light receiving means 15, the first light receiving means 15 at the center can be easily aligned.

  Here, when the transmitter 1 is manually moved, the control unit 11 may output data for stably emitting light instead of the video signal based on information of a switch (not shown), and the second light receiving unit 23a. In accordance with the characteristics of ˜23d, low rate information may be transmitted. In this case, the second light receiving means 23a to 23d can be realized with a low-cost light receiving element, which can contribute to the cost reduction of the entire apparatus.

<Embodiment 3>
Next, a preferred third embodiment of the present invention will be described in detail with reference to the accompanying drawings. FIG. 4 is a block diagram showing Embodiment 3 of the optical wireless transmission apparatus for realizing the manual optical axis alignment method of the present invention. The transmitter 1 and the receiver constituting the optical wireless transmission apparatus of the present invention are shown in FIG. 22 is a block diagram of each component.

  Since the configuration of the transmitter 1 is the same as that of the first embodiment, a description thereof will be omitted, and the receiver 22 will be described. Since the receiver 22 receives the first optical transmission signal spatially transmitted by the first optical transmission means 4 of the transmitter 1 at a relatively wide incident angle as in the first embodiment, the first optical reception means (For example, a PD, APD, and a condensing lens) are received by 15 and subjected to processing such as electrical amplification by the light receiving circuit 16, and an external device not described here by the received signal processing circuit 17. The data is converted into a signal to be transmitted to (for example, an image receiving device) and the data is transmitted to the external device.

  The receiver 22 also has an optical viewing means 28 for adjusting the optical axis of the first optical transmission means 4 of the transmitter 1. The optical viewing means 28 displays visible information according to the amount of received light, and for example, an infrared sensor card can be used. Therefore, the receiver 22 can provide visible information to the transmitter 1 by the optical viewing means 28. The optical viewing means 28 provides the visual information to the operator of the transmitter 1 by visually displaying the state of the irradiation position according to the irradiation direction of the first optical transmission signal transmitted from the transmitter 1. To do.

  Next, an outline of the optical axis alignment method in the optical wireless transmission apparatus according to the third embodiment will be described. When optical transmission is performed indoors, the distance between the transmitter 1 and the receiver 22 is at most about several tens of meters. Therefore, first, the light receiving element of the first light receiving means 15 of the receiver 22 is Similar to the first embodiment, it has a relatively low directivity, and is adjusted in the direction of the transmitter 1 with a scale. The transmitter 1 converts a video signal or the like into an optical signal and outputs a first optical signal. In the receiver 22, the first optical signal is received and converted into an electric signal, and is output to the outside as data such as a video signal. The reception state of the first optical signal is visible by the optical viewing means 28. Displayed.

  That is, when the optical viewing means 28 is an infrared sensor card, as shown in FIGS. 4 and 5, the optical viewing means 28 surrounds the first light receiving means 15, and from the first light receiving means 15. The infrared sensor card is arranged so as to spread two-dimensionally outward, and when the infrared ray that is the transmission light from the transmitter 1 is irradiated on the surface of the infrared sensor card, the infrared sensor card reacts with the infrared ray to convert it into visible light. Emits light. Therefore, when viewed from an operator (not shown) of the transmitter 1, the infrared sensor card does not emit light unless the infrared light from the transmitter 1 properly irradiates the first light receiving means 15. Correct irradiation here means that when the directivity angle of the transmitted light is 1.2 degrees, the radius of the light spot at a location 10 m away from the transmitter 1 is about 10 cm, and this light spot hits the infrared sensor card. Say it. Therefore, the optical axis of the first optical transmission means 4 is manually adjusted to the receiver 22 by moving the pan rotation mechanism 26 and the tilt rotation mechanism 27 of the transmitter 1 while looking at the surface of the infrared sensor card. In other words, the infrared sensor card emits faint light when properly illuminated, and the operator can confirm that the transmitter 1 is properly facing the receiver 22 by viewing it. .

  In the third embodiment, an infrared sensor card is used as the optical viewing means 28. However, the present invention is not limited to this, and other elements may be used as long as visible information is displayed according to the amount of received light. Can do.

  The configurations of the transmitter and the receiver of the optical wireless transmission apparatus described in each of the above embodiments are examples for explaining the technical idea of the present invention, and the configurations can be changed as appropriate. It is.

1 is a block diagram showing a first embodiment of an optical wireless transmission apparatus according to the present invention. It is a block diagram which shows Embodiment 2 of the optical wireless transmission apparatus which concerns on this invention. It is an example of the front view of the receiver of FIG. It is a block diagram which shows Embodiment 3 of the optical wireless transmission apparatus which concerns on this invention. It is an example of the front view of the receiver of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Transmitter 2 Transmission signal processing circuit 3 Light emitting element driver 4 1st light transmission means 11 Control part 15 1st light receiving means 16 Light receiving circuit 17 Reception signal processing circuit 18 Reception level detection circuit 20 Light emitting element driver 22 Receiver 23a -23d second light receiving means 24a-24d light receiving / light emitting circuit 25, 25a-25d second light transmitting means 26 pan rotation mechanism 27 tilt rotation mechanism 28 optical viewing means

Claims (2)

Optical wireless transmission comprising a transmitter having first optical transmission means for transmitting an optical signal having directivity and a receiver having first optical reception means for receiving the optical signal and converting it into an electrical signal A device,
The transmitter is
An optical axis adjustment mechanism for manually adjusting the optical axis of the first optical transmission means;
The receiver
A second optical transmitter that emits light at an intensity level corresponding to the level of the signal received by the first optical receiver;
An optical wireless transmission apparatus in which the optical axis of the first optical transmission means is manually adjusted in accordance with the intensity level. Optical wireless transmission comprising: a transmitter having first optical transmission means for transmitting an optical signal having directivity; and a receiver having first optical reception means for receiving the optical signal and converting it into an electrical signal. A device,
The transmitter is
An optical axis adjustment mechanism for manually adjusting the optical axis of the first optical transmission means;
The receiver
A plurality of second optical receiving means arranged around the position of the first optical receiving means for receiving the optical signal;
A plurality of second optical transmitters arranged near each of the second plurality of optical receivers and emitting light at an intensity level corresponding to the level received by each of the second plurality of optical receivers; ,
An optical wireless transmission apparatus in which the optical axis of the first optical transmission unit is manually aligned so that the intensity levels of the second plurality of optical transmission units are the same.

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