Sony RDR-GX7 Technical Notes - Page 32

RDR-GX7 Technical Notes Chapter 4-6 Drive and Deck mechanism s Functions integrated on two newly developed ICs In the design of the RDR-GX7, two new ICs were specifically created. The CXD9711R contains the RF amp which is used to read and write signals, while the larger S4 is mainly used for encoding and decoding circuitry. The S4 also contains the servo DSP and ATAPI control circuitry. In addition, the S4 also includes the circuitry for various signal processing functions for DVD recording which are explained in the following sections. The CXD9711R and the S4 are used in the Dual Drive circuitry s Precise signal control for DVD recording In order to perform highly precise DVD recording in an optimal manner on each form of DVD media, both the write strategy control (that includes DVD laser power control) and address data extraction are important factors. The Dual RW Drive employs a digital PLL to create write strategy, while LPP extraction is performed by digital processing for DVD-R/-RW media and ADIP extraction for DVD+RW media. In particular, for LPP signal processing, an automatic following function is employed to vary the slice level depending upon the hardware. For ADIP signal processing, original detection methods are utilized after A/D conversion. In these ways, various types of media are easily handled, enabling a high level of Dual RW recording capability. Solidly designed mechanism for top performance in all areas Behind the stylishly flat design, serious considerations were made to the fundamental construction of this DVD recorder. One essential requirement is the need for virtually silent operation in order to minimize any intrusive noise during use. Also, to ensure stable DVD recording, heat generation must also be thoroughly studied. In the planning of the RDR-GX7, these points were carefully considered during the design and construction of the mechanism. s Highly rigid chassis and newly developed insulator feet Resonance from external sources is an extremely important factor in playback quality. In order to ensure the highest possible sound quality from recorded video content and DVD software, newly developed asymmetrical insulator feet are employed. These have been specifically developed for use with the RDRGX7 and effectively minimize external resonance effects, enabling maximum performance from the Dual Drive. In addition, L-shaped beams are employed in the chassis interior to maintain high rigidity, further limiting the effects of external resonance. s Comprehensive measures for heat dissipation and silent operation Since the pickup section in the drive has a high output, a great deal of heat is generated. In addition, when a large amount of processing is performed by the ICs, high heat generation cannot be avoided. Since this is a recorder which operates at sub-micron precision levels, it is important to find ways of holding down temperature increases in the drive section in order to achieve highly stable DVD recording. When recording in the DVD-R format, it's essential to avoid the effect where high surrounding temperatures cause the laser wavelength to increase. Due to these factors, detailed heat dissipation analysis of the RDR-GX7 was undertaken. Appropriate placement of the parts and the careful placement of heat dissipation hardware has resulted in a design that features highly efficient countermeasures. Also, quiet operation of the unit is very important for the thorough enjoyment of recorded content and DVD and CD software. For this reason, the back panel of the RDR-GX7 is equipped with a cooling fan with extremely quiet operation. Plus, the fan has a control system to change between two speeds depending upon the internal temperature in order to assure quiet operation. 32