Toshiba's Combination CD-RW and DVD Drives

Some of the most significant products brought to market have been hybrids. For example, the combination fax/copier/printer, all-in-one TV/VCR and the cellular phones that have Internet capabilities have been some of the hottest products of the past decade. Toshiba's CD-RW/DVD-ROM drives combine the writeability of a CD-Rewritable (CD-RW) drive with the multimedia playback and high capacity storage of a DVD-ROM. With its low-cost rewriteable media, and backward compatibility to read virtually all types of CD's. The Combination drives provide customers with a sound investment and an effortless transition from CD to DVD.

Prior to the introduction of the Combination CD-RW/DVD, consumers were forced to choose between either a CD or DVD drive when purchasing a computer, or paying the added price for two drives. Listening to its customers, Toshiba came up with a solution that combines the best of both worlds - customers no longer have to choose one or the other.

The capacity of CD-RW media is 650 megabytes (MB) and Toshiba's CD-RW/DVD drives can write to that full capacity. In addition, the drives can read all types of CD and DVD-ROM media - with a maximum capacity of 17 gigabytes (GB). Toshiba Combination drives are available in a standard half-height size, which requires only a standard desktop computer drive bay, which is good news in today's market where desktop real estate is at a premium. Toshiba also has introduced a line of slim-line Combination drives, meeting the needs of those using notebook computers.

An Overview of CD-RW Technology
Today's CD-RW drives enable end-users to create CD's almost as effortlessly as copying floppies. This ease of use comes with plenty of practical value, including the ability to harness the high capacity disks for rewriteable mass storage, copying CD-ROMs, or compiling customized audio CD's. In addition, the ability to randomly erase and rewrite data to the same disc as many as 1,000 times makes CD-RW considerably more appealing than earlier CD-Recordable (CD-R).

CD-RW drives are dual-function, offering both CD-R and CD-RW recording, so users can choose which recordable media is going to be the best for a particular job. Another advantage of CD-RW drives is its ability to read nearly all of the existing variations of CD-ROMs. CD-RW also offers an excellent value - CD-RW media cost as little as $2 per disk for 650MB of storage and the price of the drives themselves is hundreds of dollars less than that of the early CD-R units. Also, improvements in recording software have made archiving files as easy as dragging and dropping them onto the CD-RW drive icon in Windows Explorer.

CD-RW technology uses optical phase change technology, but does not incorporate magnetic fields like the phase change technology used with magneto optical technology. A CD-RW disc's phase-change medium consists of a polycarbonate substrate, molded with a spiral groove and other data, onto which a stack (usually five layers) is deposited. The recording layer is sandwiched between dielectric layers that draw excess heat from the phase-change layer during the writing process. In place of the CD-R discs dye-based recording layer, CD-RW commonly uses a crystalline compound composed of silver, indium, antimony and tellurium. This rather exotic mix has a very special property: when heated to one temperature and cooled it becomes crystalline, but if heated to a higher temperature, it becomes amorphous upon cooling. The crystalline areas allow the metalisized layer to reflect the laser better while the non-crystalline portion absorbs the laser beam, so it is not reflected.

The Growth of CD-RW
CD-RW drives began to emerge in 1997 when professional users such as developers, small businesses, presenters, multimedia designers and home recording artists saw the need for capacities beyond those provided by floppy discs. CD-RW drives provide the perfect solution to limited storage with capacities up to 650MB in addition to providing low-cost media upon which the information would be stored.

Many experts believe that CD-RW disks will continue to be a popular storage medium until DVD devices become the dominant medium of choice. 

An Overview of DVD Technology
DVD is a high-density optical disc format designed for the playback of large amounts of data. DVD originally stood for digital versatile disc, but is now just known as DVD. At first glance, a DVD disc looks much like its CD-ROM counterpart, and in fact there are several similarities. Both share the same 120 millimeter (mm)-diameter dimension, are 1.2mm thick plastic discs and rely on lasers to read data, but that's where the similarities end. A CD can hold 650MB, while a single-layer DVD disc can hold 4.7GB - the equivalent of a two-hour digital movie or seven times the capacity of today's CD-ROMs. Double-sided, double-layer DVD discs can store up to 17GB of data, or the equivalent of 25 CD-ROMs.

Because DVD is a digital technology, users also can be assured of little or no degeneration of their data - unlike a well-worn VHS tape or vinyl record. Consumers can depend on a high degree of investment protection and backward compatibility. DVD discs use two bonded 0.6mm substrates, which allows for double-sided recording. Because of the enhanced laser technology, the pits on the DVD discs can be made smaller and packed more tightly on the disc, increasing overall capacity. Plus, the physical format of a single DVD disc -- actually two 0.6mm discs bonded together back to back as opposed to one 1.2mm substrate as in CDs-- allows for CD compatibility and increased reliability. The two bonded substrates make the disc symmetrical and more resilient to changes in temperature, humidity and other environmental conditions, making the disc less likely to warp.

The Growth of DVD
Initially, the driving application for DVD was movie titles. However, the need for more capacity in the computer world has and continues to grow at a rapid rate. With modern-day programs fast outgrowing CD capabilities, the prospect of a single-disc, high-storage medium seemed perfect. The unprecedented storage capacity provided by DVD lets application vendors fit multiple CD titles, such as parts catalogues, map programs, and encyclopedias on a single disc, making them more convenient to use. Developers of edutainment and reference titles are also free to use video and audio clips more liberally. Game developers can now script interactive games with full-motion video and surround-sound audio with fewer restrictions on space.

Today, because DVD is based on standards set forth by the DVD Forum, it achieves backward compatibility with existing compact discs without any significant increase in the cost of a DVD player or drive. DVD discs are now available in four variations:

1. Single-sided, single layer with 4.7GB capacity
2. Double-sided, single layer with 9.4GB capacity
3. Single-sided, double layer with 8.5GB capacity
4. Double-sided, double layer with 17GB capacity

DVD-ROM:
DVD-ROM drives look much like an ordinary CD-ROM drive and have some similarities, such as an ATAPI or SCSI interface. DVD-ROM drives spin the disk a lot slower than their CD-ROM counterparts. However, since data is packed much closer together on DVD discs, the throughput is substantially better than a CD-ROM drive at equivalent spin speed. Also, while a 1x CD-ROM drive has a maximum data rate of only 150KBps, a 1x DVD-ROM drive can transfer data at 1,350Kbps, which is just over the speed of an 8x CD-ROM drive.

Today, DVD-ROM drives are being incorporated into most PCs purchased today, but can also be added as a peripheral via an upgrade kit. With MPEG-2 and Dolby Digital Surround Sound playback capabilities, DVD-ROM drives are ideal for full-length feature films and computer games with advanced graphics.

Bringing Two Technologies Together
As a leader in optical technology, Toshiba was uniquely positioned to bring this product to market. The Combination drive was made possible by Toshiba's newly developed pick-up head and a drive design that integrated a CD/DVD digital signal processor and Endec chip in a single unit. The new pick-up head incorporates two objective lenses and two laser diodes: a high power 780nm laser for writing CD-R and RW, and a 650nm low power laser for reading DVD discs. The Endec chip interfaces with the CD/DVD DSP and incorporates a CSS authenticator allowing it to decrypt the DVD copy-protection key.

Applications and Market Outlook
Applications
Toshiba believes the CD-RW/DVD-ROM drive is an unbeatable upgrade product, especially for users who require writable or rewritable functionality, with multimedia capabilities and storage capacity of a DVD-ROM. Toshiba expects this drive to be used for many personal and business applications, including storing and sharing multimedia files and presentations, Web pages and digital images. Other targeted applications include archiving, data retrieval, music storage, and editing.

Market Demand and Outlook:
CD-RW and DVD-ROM are both growing rapidly in popularity, and based on initial customer feedback, Toshiba expects a very positive response to this combination product. The drive will initially be sold primarily to value-added resellers (VARs) and system integrators, and will be available as an upgrade kit through the reseller channel.

DVD drives are used for a diverse array of applications, and are quickly replacing CD-ROM drives to become the standard optical storage device in the computer industry. According to research firm Disk/Trend, shipments of DVD-ROM drives surpass those of CD-ROM drives in 2001 with sales growing to over 60 million units.

Driving the adoption of DVD drives is the growing availability of DVD titles. According to market research firm Dataquest, currently an upward of 5,000 DVD video titles are available. By 2002, sales of DVD titles are expected to surpass CD-ROM titles, according to research firm Infotech Research. The Microsoft/Intel-authored "PC '99" specification requires DVD-ROM drives as a component for home computers.

Industry experts believe sales of DVD devices and titles will exhibit a similar growth pattern to the one experienced by CD-ROM.

Sales of DVD-Video, DVD-Audio and DVD-ROM devices into the consumer market are also predicted to exhibit exponential growth over the next five years. According to research firm Advanced Media Research, a total of 13 million homes are expected to have one or more DVD devices before the end of the century.

DVD is expected to replace audio CD, videotape, laser disc and CD-ROM technology, becoming the de facto standard for home entertainment and desktop computing. Toshiba's combination drives provide an easy path to bridge the transition from CD-ROM technology to DVD.