Technology from the DVD to see the role of physics

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Technology from the DVD to see the role of physics in the high-tech

, DVD is the physical basis of the advent and application of semiconductor lasers. 3DVD the physical basis of the key technologies in the shorter wavelength of 31, increasing the principles of the television lens aperture to improve image clarity, must increase as the number of reduced compression ratio, and thus to increase the recording capacity of DVD. In the DVD disc diameter is constant (12 puzzle), to increase the recording capacity, or reduce the signal track spacing. Or shorten the length of the signal track on the pit, which inevitably requires the signal according to the laser spot on the track decreases. According to optical theory, the focus of the laser spot on a DVD disc with the laser wavelength is proportional to the diameter d, and the numerical aperture of the lens is inversely proportional to H, ie d = K,[link widoczny dla zalogowanych], K on the grounds lens aperture shape and intensity distribution of incident laser determined constants J . Therefore,[link widoczny dla zalogowanych], to re-design of the laser head DVD Machine: laser wavelength from 780 VCD Shan (infrared laser) reduced to 635 ~ 650mn (red laser); lens numerical aperture increases to 045 by the VCD of 0.6. This, DVD, VCD of the track pitch was 1.6, twa reduced to 0.74 Ⅲ; shortest pit length of 0.83 Ⅲ by the VCD is reduced to 0.4/mr; digital stream from the VCD of 1.2MB / S increased to an average of 4.7MB / S (up to 9.8MB / S); capacity increased to 650MB by the VCD's 4.7GB, VCD is about 7 times, so that the DVD picture quality, sound quality is improved in order to further improve the picture quality, we must further reduce the laser wavelength, the use of sky blue laser. Pioneer Corporation has developed a blue laser called the SHG wavelength 425rtm. In the near future,[link widoczny dla zalogowanych], will enter the practical stage, when the DVD will step into high-definition digital TV picture quality levels are, DVD is the financial result of the development of light technology continues to 3.2 using laser holographic technology, a single DVD disc double-focusing lens with CD, VCD disc physical structure is different. Is a double layer DVD disc (to increase storage capacity.) Layer thickness of 0.6 × 2,[link widoczny dla zalogowanych], CD, 'VCD disc is single layer structure, thickness 1.2mnl order with CD, VCD compatible CD-ROM, DVD machines use single-lens double-focusing method, with non-spherical lens, using laser holography that play a dual laser head objective lens effect. DVD in the near focal point to form the focus, numerical aperture 06. The center of the light through a lens, produce holographic effects due to reflection, and the objective lens with numerical aperture of 0.45 to form another lens, the focal point of much focus as the CD, 46 \4 White jurisprudence is the basis for today's high-tech future, and even radio, tape recorders, video recorders to CD, VCD, D'gD upgrading, can clearly see that the history of audio-visual technology, reflecting the history of physics. Each audio-visual technology revolution, are a breakthrough in the physical theory and the resulting application of new technologies based on the resulting physics is not only D, D technology base, but also other high-tech present as well as the foundation for the future prospects in the next century, theoretical breakthroughs and high-temperature superconducting materials, high-temperature superconducting wide range of applications, will give the electric power production, transmission,[link widoczny dla zalogowanych], the use of the epoch-making revolution; successful development of controlled nuclear fusion reaction will be a fundamental solution to the world energy crisis , to provide humanity with endless energy. References 1 official threshold standard digital video disc (vD) technology and the development prospects of TV technology 1997.7 ~ 102 He Wenlin CD player principle, commissioning and maintenance. Du electronics industry publication. 199,728 German nanotechnology research network established 19 research institutes in Germany on July 28 at the Karlsruhe Research Center signed a cooperation agreement to establish a research network throughout Chiang, to jointly study known as \nanotechnology participate in the study of a network of agencies, including Max Planck, Fraunhofer, Helmholtz Research Institute under the 7 three research institutes, 10 universities and two representatives of large corporations that these agencies This research network will contribute to the establishment of the German research institutes, universities and industry in the innovation potential of nanotechnology coordination together and join forces. Usually refers to the size of nano-structure at 100 nm (1 nm ~ ppm mm) below the tiny structure. In this level of research material and material processing technology known as nano-technology material atoms or molecules in the application of nanotechnology rearranged, often presents many new features, and can constitute the new material. Keeping on Excellent Nanotechnology has the next century as the field of scientific research and innovative strategies and plans for a world leader in the field (from (Science Times) 19983)