Sensing a strategic market opportunity, Sony Corporation has now announced that it will be introducing two separate optical pickups capable of reading DVD, CD-ROM, and CD-R discs.

Sony Announces Twin Laser Optical Pickups for Reading DVD, CD-ROM, and CD-R

Hugh Bennett
CD-ROM Professional, October 1996

The prospect of incompatibility with CD-Recordable discs has been, until now, a serious issue undermining the introduction of DVD and its derivatives. The problem involves the change in light wavelength from 780nm infrared used in CD-R to 635/650nm red used for DVD. [see “DVD: A Problem Ignored”]. Sensing a strategic market opportunity, Sony Corporation has now announced that it will be introducing two separate optical pickups capable of reading DVD, CD-ROM, and CD-R discs.

To achieve backward compatibility with existing CD-ROM and CD-R discs, the new pickups employ an ingenious two semiconductor design that joins an existing innovative 780nm laser coupler with either a 635nm or 650nm pickup.

Unlike older optical pickup designs, Sony’s laser coupler integrates all the components of a 780nm pickup (except for the objective lens) into a tiny 1.8mm x 3.4mm package small enough to ride as a passenger on their DVD pickup.

According to a Sony spokesperson, for 70,000 yen (approximately $750) each, evaluation samples of the pickups will be available in October 1996. Mass market production is slated for the end of 1996, with initial volume anticipated to be a combined 50,000 units per month. Greater production will undoubtedly be constrained by the lack of availability of 635/650nm wavelength semiconductor lasers that are expected to be in very short supply worldwide. Final pricing has yet to be established, but the twin laser pickups are expected to be only slightly more costly than a single laser pickup due to the enormous economies of scale in producing the existing 780nm laser coupler. In 1996 alone, Sony says they will have shipped 50 million laser coupler optical pickups, 30 million of which are installed in CD-ROM drives.

Sony’s announcement will come as a relief to many users and manufacturers concerned about the potential ramifications of the incompatibility problem. The most notable of these is the world’s largest CD-R media manufacturer, the Eastman Kodak Company. As far back as January 1996, Kodak communicated their concerns to the DVD Licensor Consortium warning that “if this issue is not addressed and resolved, the industry runs the risk of disappointing and confusing customers upon the introduction of this important new format. The result will be slower adoption of DVD or stifling of the growth of CD-R, or possibly both.”

Needless to say, the most vocal proponent of a twin laser DVD pickup solution is Kodak. According to Larry L. Zimmer, Kodak’s General Manager of Small Format Media, his company “is very pleased with the recent announcement of the twin laser optical pickup. This approach clearly addresses the issue of compatibility of DVD drives with the rapidly growing installed base of CD-R discs. We expect that customer acceptance of CD-R and DVD will be significantly enhanced. Kodak plans to recommend that customers of our CD-R and Photo CD products specify drives with dual wavelength capability as they migrate to DVD in the future.”

Kodak is by no means the only player ecstatic about what has been described by some as a “dream pickup”. Taiyo Yuden’s Dr. Takashi Ishiguro, who is largely credited with the original development of dye-based CD-R media, says that his company “greatly appreciates what Sony has done and strongly supports their introduction of a dual laser pickup system. We hope other companies will introduce new pickups with the same concept.”

Sony’s twin laser pickups will also simplify backward compatibility with standard replicated compact discs. While regular CD-ROM can be read at shorter wavelengths, DVD pickups must still compensate for the radical physical differences between the two disc types. Many options have been explored, such as using optical pickups with liquid crystal shutters, using two lenses that can be automatically switched, and using dual focus systems with hologram technology. Some observers, however, question the wisdom of taking chances with something as important as DVD’s backward compatibility by entrusting it to unproven and more complex technologies. In their view, it is only common sense to use a 780nm pickup that already has an established track record.

These observers also express the opinion that Sony’s twin laser pickup will eliminate the anxiety of those who are afraid to invest in CD-R technology because of fear that CD-R discs may not be read by DVD devices. Also, as it becomes clearer that the introduction of DVD-Recordable and DVD-Rewritable is still several years away, the announcement of a dual laser pickup fires the imagination for the potential development of convergence products such as a DVD-ROM drive that may as well write CD-R discs.

Analysts add that a further advantage of Sony’s dual pickup device is the fact that the twin laser pickup has the potential to provide tremendous product differentiation to hardware manufacturers trying to convince potential buyers to choose their product. If used to good advantage, the capabilities of the pickup, combined with significant promotion, could provide a powerful marketing tool creating a rush to employ it or use similar systems.

Many industry insiders see a twin laser hardware solution as being vastly superior to the alternative of a new upwardly compatible CD-R Type II disc with re-tuned optical stacks capable of being read at both 780nm and 635/650nm wavelengths, as proposed by Philips Electronics. Critics of the proposed CD-R Type II point out that so far no such viable disc has yet been developed and that it is highly unlikely that it will be possible to achieve the necessary optical performance and compatibility at both wavelength ranges with currently available recording material technology.

Of Type II, it is also said that there is fear of abandoning the large installed base of already written CD-R discs and thus undermining the foundation of interchangeability that has led to the technology’s success. Difficulties even keeping up with demand for current CD-R discs are cited, as is the unwillingness of the DVD Consortium to require DVD devices to recognize Type II discs or to make the internal adjustments needed to read them. “Even if CD-R Type II was possible,” says one hardware manufacturer privately, “there is no guarantee that DVD players could ever read them.” As a result, he feels “there is no real momentum behind CD-R Type II.”

About the Author

Hugh Bennett, editor-in-chief of Hugh’s News, is president of Forget Me Not Information Systems, a reseller, systems integrator and industry consultant based in London, Ontario, Canada. Hugh is author of The Authoritative Blu-ray Disc (BD) FAQ and The Authoritative HD DVD FAQ, available on Hugh’s News, as well as Understanding Recordable & Rewritable DVD and Understanding CD-R & CD-RW, published by the Optical Storage Technology Association (OSTA).

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