1. Field of the Invention
The present invention relates to a coupling structure of an optical connector, in particular, to that of an optical connector serving as an optical connecting device to be connected to a small-sized optical component which is, like an optical semiconductor module used in an optical communication system and others, fixed to a board.
2. Description of Prior Art
There have been developed and used various types of optical connectors and some of them are disclosed in Japanese Patent Provisional Publications No. 211276 of 1997, No. 43453 of 1997, and No. 265026 of 1997. Among them, in an embodiment where an optical semiconductor module disclosed in Japanese Patent Provisional Publication No. 211276 of 1997 and an optical connecting device using the optical semiconductor module are employed, the embodiment has an optical semiconductor module, which has a package body accommodating a semiconductor laser and an optical fiber optically coupled thereto and double side walls respectively provided with a recess and formed in the traveling way of the laser light radiated from the semiconductor laser, and a simplified connector to be coupled with said module, having a recess in the inner wall holding a ferrule to which one end of the optical fiber is fixed, and being provided at its front end with a protuberance, and optical fibers are optically coupled with each other through the coupling of the ferrules by coupling the simplified connector with the optical semiconductor module.
Though these conventional optical connectors are suitable, to some extent, for producing a large amount of low cost and small-sized optical semiconductor modules indispensable in optical fiber communication systems, they usually still have some following problems. That is to say, special tools are necessary for centering the ferrules during the assembly work of coupling the module with the connector, and this makes the assembly difficult. In case that the coupling sequence for a mate optical semiconductor module starts from a ferrule and there is no means to ensure the centering for the ferrules, a successful coupling is hard, the ferrule or a sleeve is sometimes damaged, and the coupling work eventually becomes difficult. Further, even if there is a guide means for centering the ferrules, this guide means does not sufficiently answer the need of low cost because the guide means is provided as a member completely independent of a lock means for locking the coupling of the mate optical semiconductor module, and this causes an increase in the number of components. Furthermore, the optical connection has been unstable due to the lack of means for ensuring the ferrule alignment after the coupling.
An object of the present invention is to provide a structure allowing the conventional technological problems described above to be eliminated for an optical semiconductor module, an optical connector, or a shape adapting optical connector.