JP4814126B2 - Photoelectric conversion device for optical terminal device addition - Google Patents

Description

  The present invention relates to a photoelectric conversion device that adds an optical information signal transmitted through an optical network, for example, to an optical terminal device that converts the optical information signal into an electrical information signal at a terminal of the network and outputs the electrical information signal.

  An optical terminal device may be used for a joint reception system using an optical network, for example. In such a joint reception system, it is necessary to be able to receive an emergency notification or the like by an optical terminal device even during a power failure. A countermeasure for that is disclosed in, for example, Patent Document 1.

  In Patent Document 1, an anode of a photodiode that is a light receiving element is grounded via a current multiplication transformer. The cathode of the photodiode is connected to the positive power supply terminal through a series circuit of three resistors. In this series circuit, a backflow prevention diode is connected with its cathode as the photodiode side and its anode as the positive power supply terminal side, and a large capacity capacitor is connected between the cathode of this backflow prevention diode and the ground potential point. . When a positive voltage is supplied to the power supply terminal and the photodiode is operating, the large-capacity capacitor is charged at the same time. When a positive voltage is not supplied to the power supply terminal due to a power failure, the large-capacity capacitor is discharged and the photodiode is operated.

JP 2006-174221 A

  In this optical terminal device, the large-capacity capacitor functions as an uninterruptible power supply device, so that the photodiode can be operated even during a power failure. For example, in a state where the optical terminal device already exists, in order to enable this optical terminal device to operate even during a power failure, a large-capacitance capacitor must be added to the circuit provided inside the optical terminal device. The work is troublesome. In particular, when there are a large number of optical terminal devices, a large amount of labor is required for adding a large-capacity capacitor to each of them. In addition, these large capacitors are expensive.

  An object of the present invention is to provide a photoelectric conversion device that can be added to an optical terminal device with a simple operation and that can convert an optical information signal into an electrical information signal and output it in the event of a power failure.

  The photoelectric conversion device of one embodiment of the present invention includes non-feed photoelectric conversion means. This parasitic power photoelectric conversion means converts the supplied optical information signal into an electrical information signal and outputs it even when no operating power is supplied. This photoelectric conversion device also has a synthesis means. The output side of the above-mentioned parasitic power conversion means is connected to the input side of the combining means. Furthermore, the input side is also connected to the output side of the feed photoelectric conversion means. The feeding photoelectric conversion means converts an optical information signal into an electrical information signal and outputs the electrical information signal in the feeding state. The feeding photoelectric conversion unit may include an amplification unit that can output an amplified electrical information signal. The synthesizing unit synthesizes and outputs the input electrical information signal. This synthesizing means operates even in a non-powered state, and is composed of, for example, only passive elements.

  In the photoelectric conversion apparatus configured as described above, at the time of power feeding, an optical information signal is converted into an electrical information signal by the feeding photoelectric conversion means, and this electrical information signal is output through the combining means. When no power is supplied, the optical signal is converted into an electric signal by the non-feed photoelectric conversion means and output through the combining means. Therefore, it is possible to obtain an electrical information signal even in the event of a power failure by simply connecting the feed photoelectric conversion means and the non-feed photoelectric conversion means so that the optical information signal supplied to the feed photoelectric conversion means is also supplied to the non-feed photoelectric conversion means. it can. Moreover, there is no need to remodel the internal structure of the feed photoelectric conversion means for that purpose.

  An optical input terminal can be provided in this photoelectric conversion device. The optical information signal is supplied to the optical input terminal. This optical information signal is supplied from an optical network using, for example, an optical fiber. The optical information signal from the optical input terminal is supplied to the light supply means, and the light supply means supplies a part of the supplied optical information signal to the parasitic photoelectric conversion means. Among the optical information signals supplied to the light supply means, those other than those supplied to the parasitic power photoelectric conversion means are supplied to the optical output terminal. The optical information signal supplied to the optical output terminal is supplied to the input side of the feed photoelectric conversion means. An electrical information signal from the feed photoelectric conversion means is supplied to the electrical input terminal. The combining means is supplied with electrical information signals from the electrical input terminal and from the non-feed photoelectric conversion means, and the output of the combining means is supplied to the electrical output terminal. The electrical output terminal is connected to electrical information processing means for processing electrical information signals.

  With this configuration, when the optical input terminal is connected to the optical network, the optical output terminal is connected to the input side of the feed photoelectric conversion means, and the output side of the feed photoelectric conversion means is connected to the electrical input terminal, a power failure occurs even during power feeding. Sometimes electrical information signals can be obtained from electrical output terminals. For example, if the optical network has been connected to the input side of the feed photoelectric conversion means, the electrical information signal is always obtained from the electrical output terminal by simply disconnecting the connection and connecting as described above. Therefore, there is no need to modify the inside of the feed photoelectric conversion means, and the work efficiency is very high.

  The optical information signal can be an optical television broadcast signal, the electrical information signal can be a high-frequency television signal, and the feed photoelectric conversion means can be an optical terminal device.

  If comprised in this way, in the joint reception system using an optical network, an emergency notice etc. will be receivable by an optical terminal device also at the time of a power failure.

  In addition, the optical supply unit may be an optical branching unit, and the power of the optical information signal supplied from the optical branching unit to the parasitic photoelectric conversion unit may be smaller than the power of the optical information signal supplied to the feeding photoelectric conversion unit. it can.

  With this configuration, at the time of power feeding, the same electrical information signal is output from both the non-feed photoelectric conversion means and the feed conversion means, and is synthesized by the synthesis means, but the power of the electrical information signal from the non-feed photoelectric conversion means is As a result, the electrical information signal from the power conversion means is hardly disturbed.

  As described above, by adding the photoelectric conversion device according to the present invention to the optical terminal device, it is possible to convert the optical information signal into an electrical information signal and output it by the non-feed photoelectric conversion means even in the event of a power failure. Since the conversion manual is not operated, the optical information signal from the non-feed photoelectric conversion means is not disturbed by the feed conversion means. In addition, the optical terminal device can be simply connected to the optical terminal device without any modification.

  The photoelectric conversion device 2 according to the first embodiment of the present invention is added to an optical terminal device, for example, an optical subscriber terminal device 4. The optical subscriber terminal device 4 is an example of a feeding photoelectric conversion means provided in an optical network, for example, a terminal of an optical transmission line in an optical joint reception system, for example, each home. That is, the optical subscriber terminal device 4 operates in a state in which operating power is supplied, and in general, an optical information signal transmitted through an optical transmission line that forms part of the optical joint reception system, for example, the optical fiber 6. In response to this, it is converted into an electrical information signal, for example, amplified and supplied to the processing means. The electrical information signal is, for example, a high-frequency television signal that can be watched by being supplied to a television receiver as it is, and an optical information signal, for example, an optical television signal, is obtained by modulating the optical signal. The signal processing means is, for example, the above-described television receiver.

  In the first embodiment, the photoelectric conversion device 2 is installed between the optical fiber 6 and the optical subscriber terminal device 4.

  The photoelectric conversion device 2 has an optical input terminal 8 to which an optical information signal, for example, an optical television signal is supplied from an optical fiber 6.

This optical television signal is supplied to an optical supply means, for example, the input side 10IN of the optical branching device 10. Optical splitter 10, two outputs, for example, a main output 10MOUT the branch output 10 BOUT, and outputs the optical television signal as a main output side 10MOUT to the branch output side 10BOUT. However, the power of the optical television signal on the main output side 10MOUT is larger than the power of the optical television signal on the branch output side 10BOUT, for example, a ratio of 10: 1 or 100: 1. In addition, the optical branching device 10 can operate | move also at the time of a power failure.

  The optical television signal from the main output side 10MOUT is supplied to the optical output terminal 14 via the optical fiber 12. The optical television signal supplied to the optical output terminal 14 is supplied to the input side 4IN of the optical subscriber terminal device 4 through the optical fiber 16. As described above, the optical subscriber terminal device 4 converts and amplifies the optical television signal into a high-frequency television signal and outputs it to the output side 4OUT when operating power is supplied.

  The output side 4OUT of the optical subscriber terminal device 4 is connected to the electrical input terminal 18 of the photoelectric conversion device 2 via a transmission line, for example, a coaxial cable 17, and a high-frequency television signal is supplied to the electrical input terminal 18. The high-frequency television signal at the electrical input terminal 18 is supplied to the electrical output terminal 22 via a synthesizer, for example, a synthesizer 20. The electrical output terminal 22 is connected to the television receiver. The synthesizer 20 is composed of passive elements and can operate even during a power failure. When an optical television signal is transmitted through the optical fiber 6 when the optical subscriber terminal device 4 is powered and operating, it is transmitted through the optical input terminal 8, the optical branching device 10, and the optical output terminal 14. An optical television signal is supplied to the optical subscriber terminal device 4. The optical subscriber terminal device 4 photoelectrically converts this optical television signal into a high-frequency television signal and supplies it to the electrical input terminal 18. The high-frequency television signal at the electrical input terminal 18 is supplied to the electrical output terminal 22 via the synthesizer 20 and from there to the television receiver.

  On the other hand, the branch output side 10BOUT of the optical branching unit 10 is supplied to a parasitic photoelectric conversion means, for example, a parasitic photoelectric converter 24. The parasitic power photoelectric converter 24 photoelectrically converts the supplied optical television signal into a high-frequency television signal even when no operating power is supplied. The high-frequency television signal from the non-powered photoelectric converter 24 is supplied to the output terminal 22 via the synthesizer 20 that operates even without power. Accordingly, when an optical television signal obtained by modulating an optical signal with a high-frequency television signal modulated with information for emergency notification or the like is supplied to the optical input terminal 8 through the optical fiber 6 at the time of a power failure, the optical television John signal is generated on the main output side 10MOUT and the branch output side 10BOUT of the optical branching device 10. The optical television signal is supplied from the main output side 10MOUT to the optical subscriber terminal device 4 through the above-described path. However, because of a power failure, the optical subscriber terminal device 4 does not operate and is connected to the electric input terminal 18. High frequency television signals are not output. On the other hand, the electric television signal from the branch output side 10BOUT is supplied to the parasitic photoelectric converter 24, where it is converted into a high-frequency television signal, supplied to the electric output terminal 22 via the synthesizer 22, and the electric output terminal. 22 to the television receiver. Therefore, it is possible to transmit information such as an emergency notification even during a power failure.

  When the operating power is supplied to the optical subscriber terminal device 4 and a high-frequency television signal is supplied from the electrical input terminal 18 to the combiner 20, the same high-frequency television signal is also synthesized from the parasitic photoelectric conversion device 24. The power of the optical television signal supplied to the parasitic photoelectric conversion device 24 in the optical branching device 10 is supplied to the optical subscriber terminal device 4. Since the optical subscriber terminal 4 amplifies the signal less than the power of the optical television signal supplied to the high-frequency television signal, the high-frequency television from the parasitic photoelectric conversion device 24 for the high-frequency television signal from the electrical input terminal 18 is also used. The influence of the signal is small, and even if there is a phase shift between the two, there is almost no influence. On the contrary, since the optical subscriber terminal device 4 is stopped at the time of power failure as described above, the high-frequency television signal from the parasitic power photoelectric converter 24 is not disturbed.

  Moreover, in order to make an emergency notification in the event of a power failure, the optical input terminal 8 of the photoelectric conversion device 2 is connected to the optical fiber 6, and the optical output terminal 14 is connected to the input side of the optical subscriber terminal device 4. It is only necessary to connect the output side 4OUT of the optical subscriber terminal device 4 to the electrical input terminal 18 and connect the electrical output terminal 22 to the television receiver. That is, since there is no need to modify the internal structure of the optical subscriber terminal device 4, it is extremely simple so that an emergency notification or the like can be made even in the event of a power failure in the existing optical joint reception system using the optical fiber 6 or the optical subscriber terminal device 4. It can be done by simple work. Therefore, this is effective for an optical joint reception system in which a large number of subscriber terminal devices 4 are already provided.

  The parasitic photoelectric converter 24 is configured, for example, as shown in FIG. The parasitic power photoelectric converter 24 includes a light receiving element, for example, a photodiode 26. The photodiode 26 receives the optical television signal, and generates a voltage according to the amount of light between the anode and the cathode at both ends thereof.

  The anode and cathode of the photodiode 26 are connected between a load, for example, a transformer, specifically, a primary winding 28 p of the high-frequency transformer 28. The primary winding 28p has an intermediate tap 28t, and the intermediate tap 28t is connected to a reference potential, for example, a ground potential. The anode of the photodiode 26 is connected to the ground potential via the high frequency blocking coil 30. As a result, the anode is not grounded in terms of high frequency.

  One end of the secondary winding 28s of the high-frequency transformer 28 is grounded, and the other end is connected to the combiner 20 shown in FIG.

  In the parasitic photoelectric converter 24, the photodiode 26 is not supplied with a bias and is used in a biasless state. Therefore, the parasitic power photoelectric converter 24 can convert an optical signal into a television signal even in a power failure state.

  In the parasitic photoelectric converter 24 configured as described above, when the photodiode 26 receives an optical television signal, a voltage is generated with the anode side of the photodiode 26 being positive and the cathode side being negative according to the received light level. Then, based on this voltage, a current flows through the primary winding 28 p of the high-frequency transformer 28, and a high-frequency television signal is induced in the secondary winding 28 s, which is supplied to the combiner 20 via the capacitor 32.

  The voltage generated in the photodiode 26 increases as the level of the optical television signal input to the photodiode 26 increases, so that the level output from the secondary winding 28s increases. Therefore, even if the input level of the optical television signal becomes high, the high-frequency television signal supplied to the television receiver can be increased, and this is effective when the maximum optical input level can be specified. If the input level is 0 dBm or less, it can be used without any problem.

  The photoelectric conversion apparatus according to the second embodiment of the present invention is configured in the same manner as the photoelectric conversion apparatus according to the first embodiment except that the configuration of the parasitic photoelectric conversion apparatus 24a is different as shown in FIG. Equivalent parts are denoted by the same reference numerals and description thereof is omitted.

  In the parasitic photoelectric conversion device 24a, the cathode of the photodiode 26a is connected to the ground potential point, and the anode of the photodiode 26a is a series circuit of a load, for example, the primary winding 36p of the high-frequency transformer 36 and the resistor 38. Is grounded. As a result, the anode of the photodiode 26 is connected to the ground potential in terms of DC, but not connected to the ground potential in terms of high frequency. Further, the secondary coil 36 s of the high-frequency transformer 36 is supplied to the synthesizer 20 via the capacitor 40.

  In the parasitic photoelectric converter 24a, the cathode of the photodiode 26a is grounded, and the anode is connected to the ground potential via the primary coil 36p and the resistor 38 of the high-frequency transformer 36. Biased. In this state, when the photodiode 26a receives the optical television signal, a negative voltage is generated on the cathode side and a positive voltage is generated on the anode side, and the high-frequency television signal is generated in the secondary coil 36s of the high-frequency transformer 36 by the current that flows. Induced.

  Even in this non-powered photoelectric converter 24a, at the time of a power failure, the photodiode 26a can be converted into a television signal with no bias applied.

  In the above two embodiments, the photoelectric converter of the present invention is implemented in the subscriber terminal device of the optical joint reception system. However, the present invention is not limited to this. For example, photoelectric conversion added to the optical terminal device in the FTTH network It can also be used as a container. In the parasitic photoelectric converter 24 of the first embodiment, the primary winding of the high-frequency transformer is connected between both ends of the photodiode 26. Instead, for example, two resistors connected in series are used. can do. In this case, the interconnection point of the resistors is connected to the ground potential, and a television signal is taken out from the cathode side or the anode side of the photodiode 26 as an output. In the second embodiment, the high-frequency transformer 36 is used, but this can be removed and the voltage generated across the resistor 38 can be used as the high-frequency television signal. Alternatively, a high frequency coil with a tap may be provided in place of the high frequency transformer 36, and the voltage between the tap and the ground potential may be used as a high frequency television signal.

It is a block diagram of the optical terminal device which added the photoelectric conversion apparatus of the 1st Embodiment of this invention. It is a circuit diagram of the parasitic power photoelectric converter of FIG. It is a circuit diagram of the parasitic power photoelectric converter of the 2nd Embodiment of this invention.

Explanation of symbols

4 Optical subscriber terminal equipment (feeding photoelectric conversion means)
8 Optical input terminal 10 Optical splitter (light supply means)
14 Optical output terminal 18 Electrical input terminal 20 Synthesizer (synthesizer)
22 Electrical output terminal 24 Non-powered photoelectric converter (Non-powered photoelectric conversion means)

Claims (4)

An optical information signal is supplied, and the optical information signal is converted into an electrical information signal without being supplied with power.
In the power supply state, the input side is connected to the output side of the feed photoelectric conversion means that converts the optical information signal into the electrical information signal and outputs, and the output side of the non-feed photoelectric conversion means. Synthesis means for synthesizing the generated signals without power supply,
Photoelectric conversion device provided. The photoelectric conversion device according to claim 1,
An optical input terminal to which the optical information signal is supplied;
A light supply means for supplying the optical information signal from the optical input terminal, and supplying a part of the optical information signal to the parasitic photoelectric conversion means;
Of the optical information signals supplied to the light supply means, those other than those supplied to the non-feed photoelectric conversion means are supplied from the light supply means and supplied to the input side of the feed photoelectric conversion means A terminal,
An electrical input terminal to which the electrical information signal from the feeding photoelectric conversion means is supplied;
Electrical output terminal
The photoelectric conversion device is provided, wherein the combining means is supplied with the electrical information signal from the electric input terminal and the parasitic photoelectric conversion means, and an output of the combining means is supplied to the electric output terminal.   3. The photoelectric conversion device according to claim 1, wherein the optical information signal is an optical television broadcast signal, the electrical information signal is a high-frequency television signal, and the feeding photoelectric conversion means is an optical terminal device. Conversion device. 4. The photoelectric conversion device according to claim 1, wherein the light supply unit is an optical branching unit, and the power of the optical information signal supplied from the optical branching unit to the parasitic photoelectric conversion unit is the power feeding unit. A photoelectric conversion device that is smaller than the power of the optical information signal supplied to the photoelectric conversion means.

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