# US 4,399,563 A · Fiber optics high speed modem

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- Number: US 4,399,563 A
- Document ID: US4399563A
- Status: Granted
- Kind: A
- Application number: 06/220,868
- Filed: 1980-12-29
- Granted: 1983-08-16
- Earliest claimed: 1978-04-18
- Assignees: Honeywell Information Systems Inc.
- Inventors: Joseph H. Greenberg
- Web page: https://patentgrep.com/patent/US4399563A

## CPC

- H04B 10/40: Transceivers
- H04B: TRANSMISSION

## Abstract

This relates to a fiber optics communication link, wherein a single optical fiber carries data bi-directionally between two computers. The first computer is coupled by means of control logic to a first transmitter and a first receiver. The first transmitter and receiver are in turn coupled to a single optical fiber by means of a Y-coupler. A second computer is similarly coupled via control logic to a second transmitter and second receiver, which is in turn coupled to the single optical fiber by means of a second Y-coupler. To minimize problems due to reflections, each receiver is disabled when its corresponding transmitter is transmitting data.

## Claims

### Claim 1

Apparatus for transmitting and receiving data, comprising:
a. master means for generating a master timing signal timing at known intervals;
b. first means connected to said master means for responding thereto by sending encoded data when said master timing signal is received;
c. a second means for decoding received data;
d. an optical fiber having a first end and a second end opposite to said first end thereof for transferring received data at said first end to said second end and at said second end to said first end;
e. a third means for coupling said first end to said first and second means;
f. a fourth means for decoding received data;
g. a slave means responding to said fourth means decoding received data by generating a slave signal;
h. a fifth means connected to said slave means for transmitting encoded data when said slave signal is received; and
i. a sixth means for coupling said second end to said fourth and fifth means.

### Claim 2 (depends on 1)

Apparatus according to claim 1 further including means for disabling said second means when data is being transmitted from said first means.

### Claim 3 (depends on 1)

Apparatus as set forth in claim 1 wherein said third means includes a first optical Y-coupler having a first leg connected to said first means, a second leg coupled to said second means, and a third leg coupled to said first end.

### Claim 4 (depends on 1)

Apparatus as set forth in claim 1 wherein said sixth means includes an optical Y-coupler having a first leg coupled to said fourth means, a second leg coupled to said fifth means, and a third leg coupled to said second end.

### Claim 5 (depends on 1)

Apparatus according to claim 1, wherein said fifth means comprises:
a second source of data to be transmitted;
third logic means coupled to said second source for encoding data from said second source; and
a second optical source coupled to said third logic means and to the first leg of said second optical Y-coupler for generating optical signals representing data from said second source.

### Claim 6 (depends on 5)

Apparatus according to claim 5, wherein said second optical source is an infrared diode.

### Claim 7 (depends on 1)

Apparatus according to claim 1, wherein said fourth means comprises:
a second optical detector coupled to the second leg of said second optical Y-coupler for detecting optical signals on said fiber; and
fourth logic means coupled to said second optical detector for decoding the optical signals detected by said second optical detector.

### Claim 8 (depends on 7)

Apparatus according to claim 7, wherein said second optical detector comprises a photodiode.

### Claim 9 (depends on 1)

Apparatus according to claim 1, wherein said first means comprises:
a first source of data to be transmitted;
first logic means coupled to said first source for encoding the data to be transmitted; and
a first optical source coupled to said first logic means and to said first leg for generating optical signals representing data from said first source.

### Claim 10 (depends on 9)

Apparatus according to claim 9, wherein said first optical source is an infrared diode.

### Claim 11 (depends on 9)

Apparatus according to claim 9, wherein said first source is a computer.

### Claim 12 (depends on 9)

Apparatus according to claim 9, wherein said second means comprises:
a first optical detector coupled to said second leg for detecting received optical data on said fiber; and
second logic means coupled to said first optical detector for decoding said received optical data.

### Claim 13 (depends on 12)

Apparatus according to claim 12, wherein said first optical detector comprises a photodiode.