Requesting Industry Expert Answers

[Kaphis]

Hi,

I am a 3rd Year Electrical Engineering Student at UBC. I am writing a formal report on Blu-Ray Disc and HD-DVD. We are required to have an interview with an expert in the industry. If you work in the industry or consider yourself an expert in the area, please answer the following questions for me. Thank you very much.

Please also PM me your information and a little background as to why you consider yourself an expert. I will include that information in my report and have you as reference so please pm me your full name and an email address for contact.

If you do not wish to give me your contact, feel free to answer the following questions too if you consider yourself an expert on the topic.

1) What is the motivation motivation HD-DVD/Blu-Ray development?
2) Why a blue laser and not a shorter wavelength laser?
3) What are some design challenges during the HD-DVD/Blu-Ray design process?
4) Why does blu-ray use a thinner disc compared to other DVDs and HD-DVD? What is the advantage and disadvantage of a thinner disc?
5) What the technical differences between HD-DVD and Blu-Ray Disc?

[WickyWoo]

Most of your questions are pretty basic. I've been working in various areas of home video for over 10 years

1) What is the motivation motivation HD-DVD/Blu-Ray development?

Money. Plain and simple.

Better copy protection than DVD's wide open CSS, and selling people the same movies again

2) Why a blue laser and not a shorter wavelength laser?

Because you have to consider the wear and tear on the medium, while still maintaining glitch free playback. Smudges, fingerprints etc scatter the laser, and the blue laser allows small enough pits for large data storage, while still being "large" enough to handle those issues.

3) What are some design challenges during the HD-DVD/Blu-Ray design process?

Pretty much above, getting good error correction software and getting the manufacturing yields up. Anything else they're not going to talk about publically, at least not right now.

4) Why does blu-ray use a thinner disc compared to other DVDs and HD-DVD? What is the advantage and disadvantage of a thinner disc?

It's not "thinner", per say, the data layer is closer to the surface. So far as I know it still retains the standard CD specs. The closer the data is to the laser, the smaller the pits you can use because there are less read errors.

5) What the technical differences between HD-DVD and Blu-Ray Disc?

As far as the physical medium goes, different data depth levels, HD has larger pit size.

The other facts again fall under the trade secret categories

[thunderhawk]

There are plenty of technical white papers available...

To add, another difficulty is the higher numerical aperture (NA) and the need for a more protective coating since the data layer is closer to the surface.
Mmm... Check this FAQ... https://www.blu-ray.com/faq/
And don't forget to check this one too... http://www.emedialive.com/Articles/R...rticleID=11392

Should help. And if you've got more questions... Here's the place to discuss them.

[Aaron]

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