Évaluations - 3, GPA: 4.3
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Facilité d'utilisation
The “pregrooved” disc is necessary in order to provide the recorder with a physical reference. The groove also contains timing information that the recorder uses to keep the CD spinning at the correct speed at all points along the disc surface. After the polycarbonate substrate is molded, the disc is spin-coated with the recording layer, an organic dye such as cyanine, phthalocyanine, or azo. The recording layer is then coated with a vacuum-deposited reflective layer, followed by a spin coat of protective lacquer. Most CD–R manufacturers add a label coating to further protect the disc from scratches. Special discs are available with a label area compatible with an ink- jet printer specifically made for printing CD–R discs. non-burned areas. The most common organic dye found in CD–R disc is cyanine. Azo dye, originally developed for types of optical recording media, is also used for CD–R discs. Cyanine and azo-based discs are sensitive to ultraviolet light, as well as heat and humidity. As such, their archival life expectancy is only about ten years. The recording surface of most CD–R discs is green, while some appear blue. This is due to the type of dye used and the color of the reflective layer. Silver and gold reflective layers yield a different color when they reflect light back through the organic dye. More recently, the Japanese firm Mitsui has developed a CD–R disc using phthalocyanine dye. These discs are gold in color, in part due to the gold reflective layer. The phthalocyanine discs are far less susceptible to the degrading effects of light, heat, and humidity, and are expected to have an archival life in excess of 100 A-1522-1 FIGURE 1: Cut-away view of a CD–R recordable CD. The pregrooved polycarbonate substrate is coated with an organic dye recording layer and a reflective layer. During recording, the laser beam burns the organic dye, momentarily raising the temperature of the dye to over 300° °°F. Inexpensive CD labeling systems are also available, from a variety of sources. Most of these allow you to print or write on a circular label with adhesive backing. These labeling systems carefully center the label on the CD in order to ensure smooth disc rotation. The adhesive backing on the CD labels is compatible with the materials from which the disc is manufactured, and should not impair the performance of the disc, or shorten its life. If you label CDs by hand, you should avoid solvent-based inks that could damage the disc. TDK makes a pen specifically for labeling CDs, which you can purchase from any pro audio dealer. The recording laser beam is the same wavelength as that used for CD playback— 780nm. The laser in the CD recorder literally burns the organic recording layer, momentarily raising the temperature of the recording layer at that spot to over 300°F. The width of a burned area, the equivalent of a pit on a prerecorded CD, is only 0.6 microns. The burning alters the optical characteristics of the organic dye, producing a different level of reflection from burned vs years. Mitsui is manufacturing these gold discs for a number of other firms, including HHB, and they have licensed the technology to other manufacturers as well. Care should be exercised in the handling and storage of all CD–R discs. Tests have shown that the green cyanine-based discs can be rendered unplayable if left exposed to bright sunlight for only a few days. Unless they are being recorded or played, all CD–R discs should be stored in their jewel cases at all times. The HHB CDR–800 recorder automatically adjusts the intensity of the laser beam to suit the specific type of dye found on the CD–R that has been inserted in the recorder. All CD–R discs from reputable manufacturers are certified to meet “Orange Book” specifications. The Orange Book is a document produced by Sony and Philips describing the technical specifications for the compact disc format. Part II of the Orange Book describes the CD–R format. You can find a considerable amount of information on the CD–R format on the websites of Maxell (and HHB (hhbusa.com or Audio Electronics 2/00 35 PHOTO 4: Inside view of the CDR–800. Two power transformers are used, and the solid copper chassis provides excellent shielding against EMI and RFI. PHOTO 4: Inside view of the CDR–800. Two power transformers are used, and the solid copper chassis provides excellent shielding against EMI and RFI. Balanced analog and AES/EBU digital signals enter the CDR–800 via the input PC board assembly. The balanced analog inputs are transformerless; the + and . legs of the balanced line are each fed to 5532 op amps operated noninverting as unity gain buffers. The outputs of these buffers are fed to the + and . inputs of a single 5532, converting the balanced signal to an unbalanced state. The use of 5532 op amps is a real disappointment. I fail to understand why the Japanese audio industry continues to use these 20-plus-year-old devices when so many hi...
Ce manuel est également adapté pour les modèles :CD-joueurs - CDR800 (95.56 kb)