JP2007110285A - Photoelectric conversion output device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform conversion into an electrical signal by selecting one of a plurality of light signals, without using optical selection switches. <P>SOLUTION: The light signal transmitted by optical fibers 2a, 2b, 2c is supplied to corresponding photodiodes 8a, 8b, 8c. The photodiodes 8a-8c are connected to loads 10a, 10b, 10c in series for composing photoelectric convertors 6a, 6b, 6c. One end of the photoelectric convertors 6a, 6b, 6c are grounded, and the other end is connected to respective contacts 12a-12c of a change-over switch 12. The contact 12d of the change-over switch 12 is connected to the positive electrode of a battery 14, and the negative electrode is grounded. Electrical signal is generated by the operation of one of the photoelectric convertors 6a-6c, operated by the operation of the change-over switch 12 and is supplied to one output terminal 18. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an optical-electrical conversion output device that converts a selected one of a plurality of optical signals into an electrical signal and outputs the electrical signal.

  Conventionally, the optical-electrical conversion output device described above may be used when, for example, a failure occurs in the optical signal of the main system, the optical signal is switched to the optical signal of the standby system and converted into an electrical signal. This example is disclosed in Patent Document 1. In Patent Document 1, an optical signal from an optical amplifier of the main system is supplied to one input end of a plurality of optical splitters. Further, the other input of each splitter is supplied with an optical signal from an optical amplifier in a standby system via an optical selection switch. The optical selection switch supplies the optical signal from the optical amplifier in the standby system to one selected optical splitter. When one of the optical amplifiers in the main system fails, an optical signal is supplied to the optical splitter that has been supplied with the optical signal from the failed optical amplifier via the optical selection switch.

JP 11-275008 A

  According to the technique of this patent document 1, even when the optical amplifier of the main system fails, the optical signal is supplied from the optical amplifier of the standby system, so that the reliability of the system is high. However, since the optical selection switch has to be used, the cost becomes high.

  The present invention can convert an optical signal selected from a plurality of optical signals into an electrical signal and output it without using an expensive device such as an optical selection switch for processing the optical signal itself. An object of the present invention is to provide an opto-electric conversion output device that can be used.

  The photoelectric conversion output device of one embodiment of the present invention converts a selected one of a plurality of optical signals into an electrical signal and outputs the electrical signal. This photoelectric conversion output device has a plurality of photoelectric conversion means to which the respective optical signals are supplied. These photoelectric conversion means convert the supplied optical signal into an electrical signal and output it. The electric signals from these photoelectric conversion means are supplied to one output terminal. A power source is provided for each photoelectric conversion means. A selection unit is interposed between each photoelectric conversion unit and the power source, and the power source is connected to a selected one of the photoelectric conversion units.

  In the photoelectric conversion output device configured as described above, only the photoelectric conversion means selected by the selection means operates by being connected to the power source, and supplies an electric signal to the output terminal. That is, only the selected one of the plurality of optical signals is converted into an electrical signal and output. In addition, the selection of the optical signal to be converted into the electric signal is performed by selecting the photoelectric conversion means to be operated, and an expensive optical selection switch is not used.

  One of the optical signals can be the main system optical signal. In this case, the other optical signals are standby system optical signals. With this configuration, for example, even if the optical signal of the main system is not supplied for some reason, the electric signal is continuously generated by operating the photoelectric conversion unit that receives another spare optical signal by the selection unit. Can be supplied to the output terminal.

  All the optical signals can be optical signals of different systems. If comprised in this way, a desired thing can be selected among several optical signals, and it can output to an output terminal.

  Each optical signal may be branched from a different optical transmission circuit. If comprised in this way, by operating a photoelectric conversion means in order by a selection means, the electric signal which converted each optical signal can be obtained in order, and each optical signal can be monitored.

  As described above, according to the present invention, a desired optical signal can be converted into an electrical signal and output without using an optical selection switch.

  In the opto-electrical conversion output device according to the first embodiment of the present invention, as shown in FIG. 1, a plurality of optical transmission circuits, for example, three optical fibers 2a, 2b, 2c are laid. These optical fibers 2a, 2b, and 2c transmit optical signals, for example, optical television broadcast signals in a joint reception system. These optical television broadcast signals have different contents.

  Optical couplers 4a, 4b, and 4c are provided in the middle of these optical fibers 2a, 2b, and 2c. The optical television broadcast signals branched by the optical couplers 4a, 4b and 4c are supplied to corresponding photoelectric conversion means, for example, photoelectric converters 6a, 6b and 6c.

  The photoelectric converter 6a has a light receiving element, for example, a photodiode 8a, to which an optical television broadcast signal is supplied. The anode of the photodiode 8a is connected to a reference potential, for example, a ground potential via a load 10a. In the other photoelectric converters 6b and 6c, photodiodes 8b and 8c and loads 10b and 10c are similarly connected.

  The cathodes of the photodiodes 8a, 8b, 8c are connected to selection means, for example, the contacts 12a, 12b, 12c of the changeover switch 12. The changeover switch 12 further has a contact 12d, which is connected to a selected one of the contacts 12a, 12b, 12c.

  The contact 12d is connected to a positive electrode of a power supply device 14 that is a reverse bias application power source for the photoelectric converters 6a, 6b, and 6c. The negative electrode of the power supply device 14 is connected to the ground potential. Accordingly, only the photodiode connected to the contact point with which the contact 12d is in contact operates, and an electric signal obtained by converting the optical television broadcast signal between both ends of the load connected in series with the operated photodiode. For example, a television broadcast signal is generated.

  A television broadcast signal generated in any one of the loads 10 a, 10 b, and 10 c is amplified by the amplifier 16 and then supplied to one output terminal 18.

  Therefore, by switching the contact 12d of the change-over switch 12 to the contacts 12a, 12b, and 12c in order, television broadcast signals obtained by converting the respective optical television broadcast signals are generated at the output terminal 18 in order. Therefore, the photoelectric conversion output device is used as a monitoring device for monitoring each optical television broadcast signal input to the head end by installing the photoelectric conversion output device at the head end of the joint reception device, for example. Can be used.

  Alternatively, at the head end of the joint receiver, for example, the optical television broadcast signals transmitted by the optical fibers 2a to 2c are the same, for example, the optical fiber 2a is the main system, and the optical fibers 2b and 2c are the standby system. When the contact 12d of the changeover switch 12 is connected to the contact 12a and the optical television broadcast signal on the optical fiber 2a is output from the output terminal 18, the transmission on the optical fiber 2a is interrupted for some reason. By switching the contact 12d to the contact 12b or 12c, a television broadcast signal obtained by continuously converting the optical television broadcast signal can be output from the output terminal 18 with very little interruption.

  Alternatively, the contents of the optical television broadcast signals transmitted by the optical fibers 12a, 12b, and 12c are made different at the head end of the joint receiving device, and one television broadcast signal is transmitted from the output terminal 18 to each terminal device. Even in such a case, the television broadcast signal transmitted to each terminal device can be sequentially switched by switching the contact of the changeover switch 12.

  The photoelectric conversion output device of the second embodiment is shown in FIG. This photoelectric conversion output device is different from the first embodiment in that one common load 10 is used for each of the photodiodes 8a, 8b, and 8c. Other configurations are the same as those of the first embodiment. The same parts are denoted by the same reference numerals, and the description thereof is omitted.

  In both the above-described embodiments, the loads 10a, 10b, 10c, and 10 are provided between the ground potential and the photodiodes 8a, 8b, and 8c. Conversely, the photodiodes 8a, 8b, and 8c are connected to the ground potential and the load 10a, It is also possible to provide between 10b, 10c and 10. In both of the above embodiments, a photodiode is used as the light receiving element, but a phototransistor can also be used. Further, although the amplifier 16 is provided, it is not necessary depending on the case. In both of the above embodiments, the changeover switch 12 is shown as a mechanical switch. However, for example, an electronic changeover switch that can be switched in accordance with a control signal can be used. In this case, switching can be performed by remote control.

It is a block diagram of the photoelectric conversion output apparatus of the 1st Embodiment of this invention. It is a block diagram of the photoelectric conversion output apparatus of the 2nd Embodiment of this invention.

Explanation of symbols

2a to 2c Optical fiber (optical transmission line)
6a to 6c Photoelectric converter (photoelectric conversion means)
8a to 8c photodiode 10, 10a to 10c load 12 changeover switch (selection means)
14 Battery (Power)
18 Output terminal

Claims (4)

An optical-electrical conversion output device that converts a selected one of a plurality of optical signals into an electrical signal and outputs the electrical signal,
A plurality of photoelectric conversion means for supplying a corresponding one of the optical signals, converting the supplied optical signal into an electrical signal, and outputting the electrical signal;
One output terminal to which the electrical signal from the photoelectric conversion means is supplied;
A power source for each photoelectric conversion means;
A selection means for interposing between each of the photoelectric conversion means and the power supply, and connecting the power supply to a selected one of the photoelectric conversion means;
Photoelectric conversion output device provided.   2. The photoelectric conversion output device according to claim 1, wherein one of the optical signals is a main system optical signal, and the other optical signal is a standby system optical signal. apparatus.   2. The photoelectric conversion output device according to claim 1, wherein the all optical signals are optical signals of different systems. 2. The photoelectric conversion output device according to claim 1, wherein each optical signal is branched from a different optical transmission circuit.

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