||Video disc (Compact Disk; CD) is the storing media that make use of light energy to write and read, has the high density of record (capacity is large), can substitute wantonly, its scope of application is quite extensive, have not merely already become the people's livelihood consumer goods of music, film, game, become the main storing media in computer information area of today even more. So, the required of the laser disc machine and DVD-ROM will be more and more strictness, too. At present, it has become the most important subject how to reduce the noise level and vibration.
The noise operating and emerging of the laser disc machine at a high speed, there are two kinds. One is because the main shaft motor drives all video discs to operate at a high speed, make the air current of the surrounding area flow accordingly, the mere video disc is caused the phenomenon swung by the air current of surrounding area, and produced the noise, call the air motive force noise. Another one is a main shaft motor while rotating at a high speed, with the noise caused of vibration emerging of the laser disc machine, called the structure vibration noise.
In this thesis, probe into the difference of noise level when change shell material of laser disc and utilize anti-shaking cushion to adjust the gap between laser disc machine and outer cover to reduce air flow rate. Another discussion is to get the noise influence in different absorbing sound material sticks on the shell of laser disc machine, then cooperate with the method “field mouth type” and commercial software MINITAB and the best Grey Relational analysis to get the best design of absorbing sound in laser disc.