Tweet

Shining CDs Spin Their Way to Global Data Transfer

Written by: Andy Marken

Article Overview: The universal storage and data transfer media.

Shining CDs Spin Their Way to Global Data Transfer

No matter where you are on the planet, it’s pretty hard not to find a shiny, spinning CD.

You get your favorite music on them.

Because computer software has become so large, they are the only practical way for you to receive and load programs.

Look something up in the library and you’re just as likely to pop a CD in the PC as you are to leaf through a book.

If you want to show someone the photos you took with your digital camera on your latest trip, you simply open the CD-based picture files.

Go to a presentation and the speaker often slides his latest disc-based version in the system. Need to send someone a number of large data files or medium-sized database, it’s easier to burn a CD and mail them) than wait for the Internet to upload and download the files.

In the past few years, CD drives have become so inexpensive that even the cheapest computer you buy will have a high-performance drive in it. If you get a better system it may include one of the more modern and more versatile CD-RW (rewritable CD) drives which will allow you to write CD-R (write once) or CD-RW media as well as read any CD – audio, video or data.

While CD technology has been around since 1980, it wasn’t until the fall of 1996 that the innocent looking disc set out to conquer the world. It was then that an industry consortium that includes Ricoh, Philips, Sony, Yamaha, Hewlett-Packard, and Verbatim's parent company, Mitsubishi Chemical Corporation, announced CD-ReWritable to the world. Document, data, image, video and music storage and exchange rapidly became readily available, fast, easy…and cheap.

This year billions of CD-R and CD-RW discs will be produced and used. Depending upon the quality of the disc and the producers’ production monitoring procedures the user will produce a disc which will protect your information for 30-100 years and can be played on almost any player, anywhere in the world…or you produce another shiny Frisbee. Unless the disc is produced by a manufacturer who will stand behind its product, it’s difficult to choose between good and marginal discs…until you have used them.

Reading
But once you’ve chosen the right CD media, they are all – ROM, R or RW – read in a similar fashion on the more than 600 million CD units that are installed in the world’s computers as well as in most CD disc players. Except for a few minor hiccups, the data will be read the same every time you drop the disc in the reader.

CD discs are fairly robust and with only moderate care they won’t suffer from the wear and tear of old-fashioned records or computer/audio tape. Verbatim and other quality CD media manufacturers recommend that when the discs aren’t in the drive or player, that you store them in the jewel case. To add years of life to the data, store the discs out of direct sunlight in a cool, dry location.

CDs are resistant to head crashes and stray magnetics that can eliminate the data on hard disks, floppies or tape. Dust on the drive’s head mechanism may cause temporary reading problems but with regular cleaning this problem quickly disappears. If the discs have dust or fingerprints on them from careless handling the disc can be easily cleaned with a dry soft cloth.

Recording Processes
Whether you’re listening to music you downloaded from the Internet and wrote onto a CD-R or CD-RW disc, you’re viewing a presentation that was stored on the media or researching a database that was shipped to your office; the basic reading processes are similar.

The drive’s laser head, which is positioned close to the face of the disc (figure 1), shines a very fine laser beam onto the disc’s shiny surface. The disc’s speed is automatically adjusted to keep the reading speed constant as the laser reads the stored data, starting from the inside of the disc and moving to the outer edge.

When the laser beam encounters a series of pits and land areas called lands, it begins the reading process. The pits and lands are arranged in a tightly packed spiral (figure 2) to enable the disc to store 650MB of data – 74 minutes of audio, four four-drawer filing cabinets of documents, over 70 color photos or nearly 30 minutes of video. If the spiral on the small disc were unraveled it would be more than five miles long.

When the laser strikes a land, the beam reflects back to the source and is picked up by a detector. When a pit is encountered the light is diffused and returns to the detector with much less intensity. The pits and lands represent “1s” and “0s” which the compute can read as data. The binary data is translated by the system’s microprocessor back into music, text, graphics, or video.

The CD has been designed so that the data can be read hundreds of thousands of times year after year without deterioration.

Two Tasks in One
Now that CD-RW drives are so inexpensive and the writing software is so easy to use, anyone can protect vital company or personal data and share it in a controlled manner with authorized personnel. Organizations can prepare sales, service and support presentations, short videos, and documents; write them to the CD media and send them to business partners, customers and prospects to simplify product installation, maintenance and repair as well as shorten the selling cycle. Family members can have their own private information stored on a disc that is safe from the prying eyes of brothers or sisters. Families can scan and store important documents and photos of valuables and store disc copies in a fireproof safe, in a lock box or with relatives.

The applications for CD-R and CD-RW media are limitless.

What distinguishes one type of CD from another is the way the data pattern is created (figure 3). With prerecorded CD-ROMs, the pits and lands are permanently pressed into the media’s plastic. With CD-R and CD-RW media the data is burned into the disc’s recording layer. With CD-R media the data is permanently recorded on the disc. The CD-RW disc can be erased and re-written about 1,000 times (called cycleability), making it ideal for applications such as back up and prototyping.
Today’s CD-RW drives can be thought of as ”CD-R Plus”, since they are a CD recorder with the added function of using the newer CD-RW discs.
Writing Techniques
As we noted the drive drives write data to the CD-R disc in a permanent way (Figure 4), the laser burns the pits (actually bumps) into the organic dye layer of the disc by heating the spot to be recorded to about 300 - 400 degrees Celsius (temperature will depend on the disc recording speed). These recorded bumps have lower reflectivity than the surrounding lands, and are optically very close to the pits found in a stamped CD, having the same light scattering effects. Generally, the reflectivity of a CD-R disc is around 65%, meaning that 65% of the laser beam’s light is reflected back to the read head.

In contrast, with CD-RW recording the drive uses a higher-power laser to change the phase of the recording layer from its highly reflective ”crystalline” state to a lower reflective ”amorphous” state (figure 5). This is accomplished by heating the spot to be recorded with a higher-power laser to about 600 degrees Celsius. As the spot cools, it becomes an amorphous ”mark” that is very close optically to the pit on a stamped CD. To change the spot back to the crystalline state, the laser uses a lower power setting and heats the amorphous mark to its glass transition temperature (about 200 degrees) and the spot will transform back to the crystalline state. With today’s advanced CD-RW drives and media, new data can be recorded directly over the old, eliminating the need to pre-erase.

Economic Storage

With 2,100 people connecting to the Internet every hour and 10,000 new web sites being added to the internet every day we suddenly have instant access to more information – documents images, audio and video – than people had available to them throughout their lifetime at the beginning of the century. It’s no wonder that our storage requirements are growing at 80 percent per year.

In addition, we are gaining access to richer data – documents that are image-enabled, video documents and complex information we need for home and business.

Rather than continually upgrading hard drives, people are increasingly looking for high-capacity, reliable and economical solutions to storing and protecting information – personal and professional – at home and at the office.

CD media – R and RW – provide the solution you can use today and tomorrow. It’s also a way you can use the data day-in and day-out as well as economically share files of all types without having to worry if the recipient can read the information when he or she receives it. Best of all, the media costs so little you never worry about sending them discs filled with information…and having them return the media.

CD-R and CD-RW have finally become the universal, reliable and disposable storage solution people need. It’s the shining solution of global information exchange.
# # #

Related Articles
  How to maintain data privacy?
  Transfer iPad movies to a new iPad
  Human Resources Management Systems Imports
  Too Many Sales Reps Are Wimps
  A Brief History of Data Communications

Article Tags:



Related Forum Posts
seeking investors for global finance opportunity - Phoenix Global Funding, Inc. is a Global Commercial Loan Brokerage, Merchant Bank, and a Business Consulting Firm that can work on commercial deals of all sizes. Our greatest strengths are revealed through our superior internet interface and our extensive private network of lenders and equity partners with which we can service any company on the planet by having the ability to broker and coordinate mergers, acquisitions, and funding of all kinds. As a full service commercial financial conduit we also provide valuation, business management, and profitability consulting. I am offering common stock ownership in Phoenix Global Funding, Inc. It is exciting to be in a position to be able to share not only ownership but profit in this latest project. Our business plan was developed from the oldest, most reliable and the most profitable business model ever created, LENDING. This is all about what the big boys do on Wall Street everyday. We are raising US$1,000,000.00 with share prices starting at $1.00. The exit strategy is in 3 years with a minimum 3 to 1 return on capital, plus a 20% profit share annually.
Re: Ideas on Using Twitter for Business - Hi KH Global, Check out TwitterFall.com and TweetAttacks.com Basically the latter is the automated version of TwitterFall You can use either tools to search and follow based on keywords
Re: Does Your Website Have a Robots.txt File? - HI Carol, Your robot file is correct; no lets work on your Page Titles & Meta Data. Do you have access to create different page titles for each page of your website? Do you have your FTP information...please do not post it here but just let me know if you have access. Jeff
Re: e-Commerce and e-Payment providers - Hi GT, I was always very reluctant to trust the Internet at all in the early days until I became a marketer and had to show a bit of faith. Now it is second nature to many people and I use PayPal for virtually all my transactions. Like Michelle I use Global Exchange for one of my affiliate programs but other than that it is PayPal for me. regards, Mal.
Re: What I Enjoyed Reading This Week - June 11 - Hi Evan, Thank you for the reading material. I look forward to the general release later this month as outlined in the 'Google Analytics To Add Search Query Data From Webmaster Tools' article. Anything that helps us to understand maximise extra data from Google Analytics can only be of benefit. regards, Mal.


Share this article with your friends. Fund someone's dream.

Leave a comment below or share on the left and you'll help support entrepreneurs in Africa through our partnership with Kiva. Over $50,000 raised and counting - Please keep sharing! Learn more.

Tweet

Newsletter

Get advice & tips from famous business
owners, new articles by entrepreneur
experts, my latest website updates, &
special sneak peaks at what's to come!

Name:
Email:

Popular Articles

Stay Employed In A Down Economy

Tips to Take Control of Credit Card Debt

A New Year in the Pharmaceutical Industry

Suggestions

Email us your ideas on how to make our
website more valuable! Thank you Sharon
from Toronto Salsa Lessons / Classes for
your suggestions to make the newsletter
look like the website and profile younger
entrepreneurs like Jennifer Lopez.