Insert laser pointer into the interface of the computer case

Insert laser pointer into the interface of the computer case.
In recent years, short-wavelength semiconductor laser technology, thin disc substrate technology, the lens material of high numerical aperture NA of the technology advances, so that the disc of high density recording density possible, while continuously variable digital image compression technology also a great improvement, so long continuously variable high-definition images included in a CD possible. On the basis of these techniques are laid, the world's ten largest companies together to develop a new generation of digital video disc DVD (digital video disk) standards, both in the same size and the original CD, the recording capacity of 7.5 times the original CD-ROM 4.7G, and high-quality MPEG2 digital signal compression method, so that it can store 135 minutes of film. Most of laser pointer are wrapped with plastic or metal.
DVD player mainly by the optical head and MPEG2 decoder composed of two key technologies, including MPEG2 decoder as a common standard, the current chip manufacturers to develop less than a dozen, while the optical head technology also mainly rests in the Japanese firms the hands. CD-ROM technology is a bunch of folding back the boundaries to be focused to the smallest laser beam to the disk, the disk as a record of information of the different light reflection bump, you can read the information on the disk. For the optical head is concerned, its unique technology can be: through the use of folding back the boundaries to be focused to the smallest laser beam through the transparent plastic layer 0.6mm, removed from the convex surface of the signal information. The remote control distance of laser pointer is no less than 15 meters.
Using the semiconductor laser diode, the use of numerical aperture NA of 0.6 rem in a lens, the wavelength of the laser beam is focused on the grounds off limits until the decision back to the minimum beam. CD-ROM disc shape of the different exchange errors and bring the focus lens position on the matter in the disc information recording surface of the position change, as well as CD-ROM disk rotation time up and down vibration can also cause changes in focus position, focus position changes in order to auto-correction , must be capable of an accuracy of ± 1μm of the focus position control error detection function and the servo control with built-in optical header. Stargazers can use green ray laser pointer to point at the stars at night.
The shape of the disc center and the rotation center of the disc between the eccentric correction, as well as the track pitch of 0.74μm for the track, control accuracy ± 0.1μm laser beam control for track-tracing function with error detection and control using The built-in optical servo header.