JVC Archival Grade DVD vs Gold Discs
Fact 1: Is the Gold reflective layer better?
Yes, gold does not oxidize, however, it is important to note, that generally gold has reflectivity lower than silver.
(*) Low reflectivity may trigger a higher error rate. And, it follows that discs with a high error rate can be affected
by external conditions easily.
For JVC Archival Grade DVD-R we use specially developed “silver alloy”, which has a better reflectivity and a
lower error rate as compared to gold discs. More importantly, most of the drives are designed and developed
based on silver based media.
(*)The reflectivity rate (Rg) of JVC Archival Grade DVD-R is higher than 45%. This percentage is standardized
in the book spec. Our research shows that the reflectivity rate of some gold discs is lower than 40%, which
means higher possibility of initial errors.
Archival lifetime could be affected by the storage capability of DVD-R. It goes without saying that rigorous
specifications for the electrical and mechanical characteristics of the DVD-R are important, but the raw
materials used for the DVD-R, such as reflective layer and organic dye, are also vital.
Our Archival Grade DVD-R employs a uniquely devel-oped "special alloy" on the silver based reflective layer to
maintain suitable reflectivity so that long-term storage capability can coexist.
Employing our uniquely developed “silver-alloy”*2 in the reflective layer to prevent deterioration of the reflective
layer*1.
The properties of metal particles are less likely to change during long-term archiving. By minimizing
deterioration in the reflective layer with time, stable playback can be maintained for a very long time.
*1 Reflective layer
There is a reflective layer inside the disc that is adjacent to the recording layer. It plays the important role of
reflecting the laser light during playback.
Minimizing deterioration of this reflective layer with time helps to stabilize light reflectance, thereby minimizing
signal degradation, making long-term archiving possible.
*2 Silver alloy
In general silver is used for the reflective layer of DVD-Rs; however one shortcoming is that silver reflective
coatings are susceptible to corrosion.
This product employs silver alloy, which has improved corrosion resistance, which has enabled successful
long-term archiving.
Hard-coat recording surface that is “scratch-, stain-, and dust-resistant”
1.
The unique high-performance hard coat developed by JVC makes the disc resistant to scratches, dust,
and stains, which may impede precise recording or playback. With this hard coat, important data can
now be protected for a long period.
2.
For JVC products the degree of scratch-resistance improves by more than 200 times as compared to
DVDs without a hard coat.
And, the lubricity of the surface is optimized, making it more resistant and easier to remove stains
including sebum from our finger prints. The results show the disc surface is seven times less affected
by finger prints as compared to the standard disc.
3.
Our products also have excellent antistatic, which minimizes the generation of static, thus preventing
dust attachment (static charge decay time is about a thousandth compared to other JVC products).
Fact 2: What will happen when an organic dye decomposes?
When an organic dye decomposes,signal (data) cannot be read back. The reflective layer is not the only
important factor for long term archiving! Our research has shown that gold discs we purchased from the market
employ the same organic dye as standard silver discs. For JVC Archival Grade DVD-R an organic dye with
specially in-house developed additives is used. This minimizes decomposition of the organic dye and achieves
higher archive capability.
Fact 3: What is the appropriate method to define longevity of optical media?
The test method to estimate optical media longevity varies depending on the manufacturer. Each individual
company estimates the longevity based on their own test methods and there are claims in the market for 50,
100 and even 300 years of longevity! How reliable is this number?
The past practice dictates the ordinary test method to be a test of the discs under a shocking condition
(normally 80°C/80%humidity) then the time until error rate exceeds 280 is measured to estimate the longevity.
This test method is not practical and does not accurately estimate the longevity at ambient condition (25°C/50%
humidity), which is a critical point that needs to be known. In order to obtain a reliable estimation the test has to
be done with multiple samples and in multiple conditions. Each result should be statistically processed.
Ordinary Test vs. ISO/IEC10995 Test
Test Method
Ordinary Test*
ISO/IEC10995 Test
Samplig size (PCE)
Test Condition
1-5
varies (normally 80°C/80% RH)
20
85°C/85% RH
20
85°C/70% RH
20
65°C/85% RH
30
70°C/75% RH
The JVC Archival Grade DVD-R passed ISO/IEC 10995. This is the only standard in the world that defines the
test method of estimating longevity of DVD-R and is a very reliable and stringent test method.
Fact 4: How can you be sure you are always getting the same quality?
The JVC Archival Grade DVD-R is manufactured only in Japan. The exclusive production and strict Quality
Control used ensure quality and reliability on a consistent basis. Each lot is tested and passes
stress/acceleration testing to ensure the archival capability and consistency of the product.
The process has thorough controls to eliminate any error occurrence factors introduced at the production
phase.
Clean Management / Production Equipment Management / Automation
(Elimination of Manual Operation)
Furthermore, stress/acceleration tests are carried out to each lot to ensure the durability and reliability is high
enough for “Archival Grade”.
[Acceleration test to each lot]