Sony RDR-GX7 Verweisanleitung

■ 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. 

■ 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. 

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. 

■ Highly rigid chassis and 

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 RDR-

GX7 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.

■ Comprehensive measures 

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. 

RDR-GX7 Technical Notes

The CXD9711R and the S4 are used in the Dual Drive circuitry