JPS58133059A - Optical transmitting circuit - Google Patents

Abstract

PURPOSE:To prevent the momentary break of information transmission when a light emitting element is faulty, by coupling optical signals of plural light emitting elements based on the same input signal and transmitting them. CONSTITUTION:Optical signals of light emitting elements 3 and 3a driven by a driving circuit 6 are transmitted to optical fibers 7 and 7a respectively and are led to a coupler 8. These optical signals are incident to a half mirror 9 in the coupler 8 at different angles of incidence, and one of them is transmitted through, and the other is reflected overall, and thus, they are coupled, and the coupled optical signal is incident to an optical fiber 4 and is transmitted to the receiving side. Thus, the switching operation in the receiving side is unnecessary and the momentary break of information transmission is prevented when light emitting elements are faulty, and a high precision is attained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an optical transmitter circuit that uses multiplexed structures to prevent missed calls due to failures.

Conventionally, there has been a duplex device of this type as shown in FIG. 1. In the figure, (1) and (la) are optical transmitter circuits having the same structure, (2) and C2m) are drive circuits, ta+ and (8a) are light emitting elements, and (4) and (4) are light transmitting circuits.
a) is an optical fiber.

Next, the operation will be explained. Optical transmitter circuit (1), (1m
) drive circuits (2) and (2m) are operated by the same human power signal and drive the light emitting elements (3) and (8a). The optical signal of the driven light emitting element (31, (8a)) is transmitted through an optical fiber (
4), (4m) is transmitted to the receiving side. Under normal conditions, one optical transmitter circuit (1) is used regularly and the other optical transmitter (LA) is used as a backup device, but if the normally used optical transmitter circuit (1) breaks down (other optical transmitters (The failure rate of the light emitting element is significantly higher than that of the components), signal transmission is continued by switching the output of the optical transmission circuit (1a) of the standby unit as the receiving input on the receiving side.

Conventional redundant optical transmission circuits are configured as described above, so the standby unit is used only when the regular unit breaks down, and switching from using the regular unit to using the standby unit requires a change on the receiving side. It requires switching, and has drawbacks such as instantaneous interruptions during switching.

This invention was developed to eliminate the drawbacks of the conventional ones as described above, and by combining and transmitting the optical signals of multiple light emitting elements based on the same human input signal, it is possible to keep used parts in regular use and spare parts. It is an object of the present invention to provide a multiplexed optical transmission circuit that is indistinguishable and does not require switching on the receiving side.

Hereinafter, one embodiment of the present invention will be described with reference to a duplex case. In FIG. 2, (5) is an optical transmitter circuit, (
6) is a drive circuit, (7), (7m) are optical fibers, (
8) is a coupler, (9) is a half mirror in the coupler (8)
Consists of one or more.

Next, the operation of the embodiment will be explained. The optical signals of the light emitting elements (3) and (8a) driven by the drive circuit (6) are transmitted through the optical fibers (7) and (7si), respectively, and are connected to the coupler (
8). These optical signals enter the half-coupler (9) in the coupler (8) at different angles of incidence, are combined by transmitting one and fully reflecting the other, and enter the optical fiber (4). and transmitted to the receiving side.

Light emitting element +31. When the optical signals in (8a) are combined, the power increases, but the receiving side is designed so that the power of only one of the optical signals is sufficient for operation.

In the above embodiment, an optical fiber (7),
(7a) is used, but as shown in FIG. 8, an optical system using lenses (10a), (10a) reflection (2), etc. may be installed.

Furthermore, although the half mirror (9) in the coupler (8) allows light to pass through or reflect the entire surface depending on the angle of incidence, it may also be made of a material with similar properties, such as a polarizing prism, etc. Needless to say.

As described above, according to the present invention, since the optical signals of a plurality of light emitting elements based on the same human signal are combined and transmitted, there is no need for a switching operation on the receiving side in the event of a failure of a light emitting element. This has the effect of providing high accuracy without momentary interruptions in transmission.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a conventional optical transmission circuit, FIG. 2 is a block diagram of an embodiment of the optical transmission path according to the present invention, and FIG. 8 is a block diagram of another embodiment of the optical transmission circuit according to the present invention. FIG. In the figure, (3) I (81) is a light emitting element, (4)
(5) is an optical fiber, (5) is an optical transmission circuit, (6) is a drive circuit, (7) e (71) is an optical fiber, (8) is a coupler, and (9) is a half mirror. In addition, in the figures, the same reference numerals indicate the same or corresponding parts. Agent Shin Kuzuno -

Claims (1)

[Claims] An optical transmission circuit comprising a plurality of light emitting elements that convert the same power signal into an optical signal, and a coupler that combines the optical signals of these light emitting elements to form a transmission signal to a receiving side.