JPH0511150A - Optical receiver - Google Patents

Abstract

(57) [Abstract] [Purpose] To obtain an optical receiving device having a wide optical communication angle of view using space as a transmission medium and capable of high-speed optical communication. [Structure] A plurality of optical receivers in which optical sensors are arranged at positions where the distance from the optical axis near the image forming surface of the condenser lens is different from each other, or in the optical axis direction from the position near the image forming surface of the condenser lens. A plurality of optical receivers having optical sensors arranged at displaced positions are arranged one-dimensionally or two-dimensionally, and an optical signal sent from the optical transmission side is received by the plurality of optical receivers and an electric signal is received. That was converted to.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical receiver, which is used, for example, in an optical space transmission system for transmitting an optical signal by using a space as a transmission medium, and in particular, an optical transmitter or an optical receiver. The present invention relates to an optical receiving device capable of performing high-speed and reliable optical communication even when a mobile station moves.

[0002]

2. Description of the Related Art Conventionally, various optical receiving devices have been proposed for receiving an optical signal sent from an optical transmitting device through a space as a transmission medium.

FIG. 7 is a schematic view of a main part of an optical system of a conventional optical receiver. In FIG. 7, 71 is an optical system such as a condenser lens, and 72 is an optical sensor such as a photodiode. In such an optical receiving device, when the device on the optical transmitting side or the device on the optical receiving side moves, the optical receiving side's optical receiving device is provided so that optical communication may not be interrupted even if the optical axes of both optical systems are slightly displaced. It is configured to have a wide possible range (optical reception angle of view) ω.

[0004]

In the conventional optical receiving device, an optical sensor having a large area is used in order to widen the optical receiving angle of view ω.

However, when the optical sensor is increased in size by itself, there is a problem that the frequency characteristic is deteriorated due to the increase of the junction capacitance of the optical sensor, and the response speed to a high-speed optical signal is insufficient.

According to the present invention, in optical communication between moving objects, a wide optical communication angle of view (optical receiving angle of view) that enables high-speed optical communication even if the device on the optical transmitting side or the optical receiving side spatially moves. An object of the present invention is to provide an optical receiver having the same.

[0007]

The optical receiving device of the present invention comprises:
A plurality of optical receivers with optical sensors arranged at different distances from the optical axis near the focusing surface of the condenser lens, or a position displaced in the optical axis direction from a position near the focusing surface of the condenser lens A plurality of optical receivers with optical sensors
It is characterized in that they are arranged two-dimensionally or two-dimensionally, and the optical signals sent from the optical transmission side are received by the plurality of optical receivers and converted into electrical signals.

In particular, in the present invention, the output signals from the plurality of optical receivers are input to the bases of the corresponding transistors, the collectors of the transistors are made common, and the signals obtained by the plurality of optical receivers are input. It is characterized in that they are combined with each other and that the optical sensors of the plurality of optical receivers are configured to be displaceable.

[0009]

Embodiment 1 FIG. 1 is a schematic view of the essential portions of Embodiment 1 of the present invention. In the figure, reference numeral 11 denotes an optical receiver, and in the present embodiment, three optical receivers 11a, 11b and 11c are arranged in a one-dimensional direction. Each light receiving section constitutes a unit unit. One light receiving unit 11a has a condenser lens 2a made of a spherical lens, an optical sensor 4a made of a photodiode provided in the vicinity of the image forming surface of the condenser lens 2a, and a mounting plate 3a for mounting the optical sensor 4a. is doing. The positions of the optical sensors 4a, 4b, 4c in the respective light receiving units 11a, 11b, 11c are arranged so that the distances from the optical axis near the image forming plane of the condenser lens are different from each other.

That is, in the present embodiment, the optical sensor 4a in the optical receiver 11a is above the optical axis La, the optical sensor 4b in the optical receiver 11b is on the optical axis Lb, and the optical sensor 4c in the optical receiver 11c is optical. It is arranged below the axis Lc. As a result, the angle of view of the optical communication is expanded, and the optical signals 6a, 6b, 6c transmitted from the various directions to the optical receiver 11 are made incident on the optical sensor of any of the optical receivers.

In the figure, the unit 1 is used for the optical signal 6a.
The optical sensor 4c of 1c receives the optical signal 6b by the optical sensor 4b of the unit 11b, and the optical signal 6c is received by the optical sensor 4a of the unit 11a. As described above, in the present embodiment, the roles of the respective units are clearly assigned to the direction of the incoming optical signal for reception.

In this embodiment, the optical sensor mounting plates 3a, 3b, 3c are the unit units 11a, 11b, 1
It is slidable along the guide in the optical axis direction and the direction orthogonal to the optical axis in 1c along the guide, and can be fixed to the housing at an arbitrary position.
Further, the optical sensor mounting plates 3a, 3b, 3c allow the optical sensor to be mounted at an arbitrary position, whereby the optical sensor is set at an arbitrary position suitable for reception.

FIG. 2 shows the optical sensors 4a, 4 of each unit.
It is a schematic diagram when the positions of b and 4c are displaced in the optical axis direction from the vicinity of the image plane of the condenser lens.

As shown in FIG. 2, by making all the positions of each optical sensor closer to the lens side than the focal position of the condenser lens, the amount of light received by each optical sensor is reduced. , 6b, 6c can be made incident. As described above, in this embodiment, the position of the optical sensor is arranged at an arbitrary position depending on the situation. When the incident direction of the optical signal is known to some extent, it is preferable to dispose the optical sensor at the focal position of the optical system for the incident optical signal from that direction, which enables the most efficient reception.

The unit unit as the optical receiver in this embodiment can be connected to another unit unit. As a result, an optical receiver is constructed by combining an arbitrary number of unit units in an arbitrary shape according to the purpose of use. For example, when used as a light receiving device of a remote control device such as a television, it is better to make the light receiving angle in the left and right directions wider than the light receiving angle in the up and down directions. In such a case, as shown in FIG. 3, it is preferable to connect the unit units 11a to 11d in a horizontal row to form an optical receiver. Further, when the signal light is transmitted as a parallel light flux by the optical system on the optical transmission side, the parallel light flux is generally substantially circular when viewed in a plane perpendicular to the optical axis.

Therefore, in such a case, it is preferable to connect a plurality of unit units in a shape as shown in FIG. 4 to form an optical receiving device because an optical signal can be efficiently received.

FIG. 5 is a schematic block diagram of an embodiment showing the signal processing of the optical receiving apparatus of the present invention. In the figure, the optical signals received by the optical receivers 11a, 11b to 11n are amplified by the multi-input amplifier 7 and then combined.

The combined optical signals pass through a band pass filter (BPF) 8, are amplified by an AC coupling amplifier 9, and are demodulated by a demodulation circuit 10 to be restored to an original electric signal to be an output signal. Here, the BPF 8 is used for removing noise light such as background light.

FIG. 6 is an explanatory view showing a circuit of an example of the multi-input amplifier 7 of FIG. In the figure, R0 to R3N are resistors, C0 to C2N are capacitors, and Tr1 to TrN are transistors. The optical signals received by the optical receivers 11a and 11b are input to the bases of the transistors under appropriate bias conditions. By making the collectors of the respective transistors common, the signals received by the light receiving section are combined and appear at the output terminal. As described above, according to the circuit shown in FIG. 6, it is possible to easily combine optical signals with a simple configuration.

The optical receiver of the present invention described above is shown in FIG.
Although the angle range in which light can be received is not different from that of the conventional light receiving device, the individual light sensors are smaller.
Therefore, since the junction capacity of the optical sensor is small, it has a feature that it can sufficiently support high-speed communication.

The optical receiving apparatus of the present invention is not limited to the above-mentioned embodiment, and various modifications and applications are possible. For example, although a spherical lens is used as the condenser lens in the above-mentioned embodiment, it is not necessarily required to be a spherical lens. For example, a lens having an aspherical surface such as a paraboloid of revolution or an ellipsoid of revolution in whole or in part may be used. Furthermore, the number of condenser lenses is not necessarily one,
It may be configured by combining a plurality of lenses.

Further, in the above-mentioned embodiment, an example in which the present invention is used as an optical receiver for optical space communication is shown, but the present invention can be applied as an optical receiver for other purposes. For example, by utilizing the fact that the light sensor that receives light is specified by the incident angle of light, it can be used as a sensor for detecting the position, direction, movement, etc. of the light source. On the contrary, when the position of the light source is constant, the light receiving device can be mounted on an object to be used as a detection device for detecting the position, direction, movement, etc. of the object.

[0023]

According to the present invention, as described above, the light receiving portion formed of the condenser lens and the optical sensor is used as a unit unit, and an arbitrary number of unit units can be combined in an arbitrary shape according to the application, so that a wide area can be obtained. An optical receiving device capable of high-speed optical communication over an optical receiving angle can be achieved.

Further, since the light sensor can be attached to an arbitrary position with respect to the condensing lens in the unit unit, the light sensor can be set at an arbitrary position suitable for light reception, and an efficient light can be obtained. Can receive.

Further, by inputting the output signals of the respective unit units to the bases of the transistors and sharing the collectors of these transistors, the optical signals can be easily combined with a simple structure. An optical receiver can be achieved.

[Brief description of drawings]

FIG. 1 is a schematic view of a main part of a first embodiment of the present invention.

FIG. 2 is an explanatory diagram when a part of FIG. 1 is displaced.

FIG. 3 is an explanatory diagram of an outer shape of the optical receiver of the present invention.

FIG. 4 is an explanatory diagram of an outer shape of the optical receiving device of the present invention.

FIG. 5 is a schematic block diagram showing signal processing according to the first embodiment of the present invention.

FIG. 6 is an explanatory circuit diagram showing optical signal processing according to the first embodiment of the present invention.

FIG. 7 is a schematic diagram of an optical system of a conventional optical receiver.

[Explanation of symbols]

11 Optical receiver 11a, 11b, 11c Optical receiver 2a, 2b, 2c condenser lens 3a, 3b, 3c Mounting plate 4a, 4b, 4c optical sensor 6a, 6b, 6c Optical information 7 Multi-input amplifier 8 band pass filter 9 AC coupling amplifier 10 Demodulation circuit

Claims (2)

[Claims] 1. A plurality of light receiving sections, each having a light sensor arranged in a position different from each other in distance from the optical axis in the vicinity of the image forming surface of the condenser lens, are arranged one-dimensionally or two-dimensionally, and are arranged from a light transmitting side. An optical receiving device, wherein an optical signal transmitted is received by the plurality of optical receiving units and converted into an electric signal. 2. A plurality of light receiving portions, each having a photosensor arranged at a position displaced in the optical axis direction from a position near the image forming surface of the condenser lens, are arranged one-dimensionally or two-dimensionally, and from the light transmission side. An optical receiving device, wherein an optical signal transmitted is received by the plurality of optical receiving units and converted into an electric signal.