1. Field of the Invention
The invention relates to a method for eliminating the noise of an optical switch and, more particularly, to a method for eliminating the noise of an optical switch, which employs an electromagnetic relay as a driver to perform a phase conversion
2. Description of the Related Art
An optical switch is a device capable of switching the light from an input terminal to a destination output terminal; that is, it has a function of switching the path of transmitting light. A conventional optical switch is mostly formed by assembling at least one light input/output device and at least one driver, wherein the at least one light input/output device is an optical component for switching incident light transmission path, whereas the driver performs a phase conversion to drive the light input/output component so that the light can be outputted to its destination output terminal in order to achieve switching light transmission path.
More specifically, as shown in FIG. 1, a common optical switch employs an electromagnetic relay as a driver. Usually, a plurality of limit switches 21, 22, 23 and 24 are provided inside the electromagnetic relay to instruct the relay to switch to its indicated phase. In addition, the optical switch includes a plurality of pin components 17 for use in circuitry, a cantilever 12 which is an activating component utilizing magnetic force to perform the phase conversion, a joint 15 for connecting the cantilever 12 and the flexible coupler 14, and an optical component 11 disposed at the front end of the arm 121. Furthermore, the antilever 12 is formed by joining an arm 121 to a cantilever sheet 122 by means of glue, laser welding, soldering or other methods, and the optical component 11 can be a lens, prism, wedged prism, or plate glass. However, since the optical component 11 has a certain weight and the arm 121 has a certain length, and the flexible coupler is made of metal sheet or plastic sheet, so that the arm 121 and the optical component 11 will generate a strong vibration when the relay is performing a phase conversion. Consequently, after the incident light has passed through the optical component 11, there is no way to form a fixed refraction orientation. Therefore, the orientation of the refracted outputted light cannot be stable, which often results in an optical insertion loss that is an unstable noise, as shown in FIG. 2. As a result, the phase will often be misjudged, and the lifespan of the relay will also be shortened.
Therefore, it is an important issue to eliminate the vibration generated by the relay during the phase conversion so that the noise of the optical switch can be eliminated as well as the lifespan of the relay can be prolonged.