Thermo-Balanced Writing
Unfortunately, there is no reliable way a consumer can judge what he or she is buying (as example, an
authoritative quality logo on the disc packaging or verification of media confirmance), and so when an End user
buys and "burns" what are, in effect, sub-standard discs, any resulting problems are liable to be attributed more
often to the CD drive unit then to the disc. It is a question of compatibility, something the End user implicitly
desires, and unfortunately, is not able to recognise whether it is there or not.
The solution
Philips, anticipating End user concerns about disc compatibility and data integrity, has applied considerable
effort to developing and testing a system of self-calibration for recording CD-R discs. This solution is "on
board" in the drive itself, and provides an excellent solution. It is part of a continuous Philips programme
devoted to the perfection of CD technology, and particularly, to anticipating and solving End user problems,
thus enabling greater Ease of Use.
The Philips solution lies in a technique designated TBW [Thermo-Balanced Writing], a feature which is to be
introduced in all new Philips CD-RW drives.TBW, partnering with a Self-Learning process, adds intelligence to
the drive and enables it to automatically make decisions about how to process and write a new disc.
CD-RW drives also write CD-RW discs of course, however,TBW technology is not applicable to the RW
function as CD-RW discs utilise a completely different recording methodology.
TBW allows many discs of lower quality to be used without anxiety, and with the assurance that the drive will
automatically determine the integrity of the recording layer, then automatically select the correct burn
conditions and associate these always with the optimal appropriate recording speed to ensure compatibility.
The process is similar to the way in which modern fax machines communicate to detect what kind of partner
machine is at the other end of a connection so that the two can transfer data properly without the user having
to guess what might be there and press buttons to set up the link.
The heart of the Philips solution is a new hardware and firmware built into the drive with the TBW algorithm
which evaluates the disc and determines the burn parameters.
The intelligent algorithm
When a disc is inserted in the drive with intention to write, the start logic immediately triggers the partner to
TBW, the self learning algorithm. In a brief interval of time, unnoticed by the End user, a sequence of physical
tests are performed on the disc to determine its’ characteristics.
On insertion, a test is automatically made in which a series of test pits are burned into the disc at the
appropriate speed and with the burn laser pulsed as necessary to achieve the optimal relationship between pits
and lands, in particular, to provide the correct reflectivity differential, the correct position, length and spacing of
each element and an acceptable block error rate.The test burn is then read and if the result corresponds,
within the tolerances allowed, then the disc is passed for recording under those conditions.
62200223-TBW 21-02-2001 16:15 Pagina 8
