Power supply system to terminal equipment through an optical fiber cable

• US 4,325,137 A
• Filed: 06/19/1980
• Issued: 04/13/1982
• Est. Priority Date: 06/26/1979
• Status: Expired due to Term

• Current Assignee: Kokusai Denshi Denwa Company Limited (KDDI Corporation)
• Original Assignee: Kokusai Denshi Denwa Company Limited (KDDI Corporation)
• Inventors: Yoshikazu, Ikeda
• Primary Examiner(s): Bookbinder, Marc E.
• Application Number:
  US06/160,943
• Time in Patent Office: 663 Days
• Field of Search: 370/1, 370/4, 370/29, 455/603, 455/606, 455/607, 455/610, 455/612, 455/614, 455/617
• US Class Current: 398/171
• CPC Class Codes: H04B 10/807 Optical power feeding, i.e. transmitting power using an optical signal
• CPC Class Codes: H04M 1/003 Telephone sets using electrooptical means in the transmission path

Abstract

In a communication system between an exchange station and terminal equipment through an optical fiber cable, a power supply for operating the terminal equipment is supplied from the exchange station through the optical fiber cable in a form of an optical energy. The optical fiber cable is utilized both for transmitting a voice signal between terminal equipment and the exchange station, and for transmitting the power supply from the exchange station to terminal equipment on a time divisional basis. When the terminal equipment is inactive, the exchange station transmits no energy, or transmits intermittently an optical pulse. The duration that the optical pulse is transmitted when the terminal equipment is inactive, is less than 1/10 of the total time. When a handset of the terminal equipment is picked-up and the terminal equipment becomes active, the change of the status of the terminal equipment is relayed to the exchange station using that limited amount of energy from the exchange station, or the output of the generator which provides the electricity upon picking-up a handset. When the terminal equipment becomes active, the exchange station is switched to constant transmitting of the power pulse to the terminal equipment for operating the same.

Claims

1. A power supply system for an exchange station to terminal equipment through an optical fiber cable for operating said terminal equipment comprising;

(a) a single optical fiber cable connecting the exchange station to terminal equipment for transmitting signals in both directions from the exchange station to the terminal equipment and from the terminal equipment to the exchange station, and for transmitting an optical energy in the form of an optical pulse from the exchange station to the terminal equipment, all of said transmissions being on a time divisional basis,

(b) a terminal equipment having at least a microphone and a receiver connected to said optical fiber cable through means for converting a signal between an electrical form and an optical form, and means for recognizing whether the terminal equipment is inactive or active and transmitting a status signal to an exchange station when the status of the terminal equipment changes from the inactive status to the active status,

(c) an exchange station having at least an exchange control system connected to the optical fiber cable through means for converting a signal between an electrical form and an optical form, a power pulse generator, a gate circuit for passing the power pulse of the power pulse generator to the optical fiber cable, said control system controlling said gate circuit so that when the terminal equipment is inactive the gate circuit opens intermittently less than 1/10 of time, and when the terminal equipment is active the gate circuit almost always opens.

2. A power supply system from an exchange telephone station to terminal equipment through an optical fiber cable for operating said terminal equipment comprising;

(a) a single optical fiber cable (33) connecting the exchange station to terminal equipment for transmitting signals in both the directions from the exchange station to terminal equipment and from terminal equipment to the exchange station, and for transmitting optical energy in the form of an optical pulse from the exchange station to terminal equipment, all of said transmissions being on a time divisional basis,

(b) terminal equipment (31) having at least an optical-electrical converter (311) connected to the end of the optical fiber cable (33), a receiver (314) connected to the output of said converter (311) through a demodulator (313), an electrical-optical converter (317) connected to the end of the optical fiber cable (33), a modulator (316) connected to the input of said electrical-optical converter (317), a microphone (315) connected to said modulator (316), a hook switch (318) for detecting the status of a handset having the microphone (315) and the receiver (314), a hook switch detector (319) for transmitting the information of a change of the status of the hook switch (318), all of the circuits in the terminal equipment (31) being operated by electric power obtained at the output of said optical-electrical converter (311), and

(c) an exchange station (32) having at least an optical-electrical converter (322) and an electrical-optical converter (321) connected to the end of the optical fiber cable (33), a hook detector (324) connected to the output of the optical-electrical converter (322) for recognizing the status of the hook switch (318), a power pulse generator (323), a gate circuit (326) inserted between the output of the power pulse generator (323) and the input of the electrical-optical converter (321), and an exchange control system (325) which controls said gate circuit (326) so that when the terminal equipment (31) is inactive the gate circuit (326) opens intermittently less than 1/10 of time, and when the terminal equipment (31) is active the gate circuit (326) almost always opens.

3. A power supply system from an exchange station to terminal equipment through an optical fiber cable for operating said terminal equipment comprising;

(a) a single optical fiber cable connecting the exchange station to terminal equipment for transmitting signals in both directions from the exchange station to terminal equipment and from the terminal equipment to the exchange station, and for transmitting an optical energy in the form of an optical pulse from the exchange station to the terminal equipment, all of said transmissions being on time divisional basis,

(b) terminal equipment having at least a microphone and a receiver connected to said optical fiber cable through conversion means between an electrical form and an optical form, a generator means for generating an electrical signal upon detection of the change of the status of the terminal equipment from an inactive status to an active status, and the output of said generator means being forwarded to said exchange station through said optical fiber cable, and

(c) said exchange station having at least an exchange control system connected to the optical fiber cable through conversion means between an optical form and an electrical form, a power pulse generator, a gate circuit for passing the power pulse of the power pulse generator to the optical fiber cable, said control system controlling said gate circuit so that when the terminal equipment is inactive the gate circuit is closed and when the terminal equipment is active the gate circuit is almost always opened.

4. A power supply system according to claim 3, wherein said generator means has a piezo electric generator operative in response to a change of condition of a handset.

5. A power supply system according to claim 3, wherein said generator means has a permanent magnet inserted in a solenoid coil so that said magnet moves when a handset is picked up.

6. A power supply system according to claim 3, wherein said generator means has a photo-cell and means for storing the electricity generated by said photo-cell.