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Optical Drive

From CD-ROMs to Blu-ray, A Look Inside A Drive

An inside look into optical drives, and an explanation into optical drives work.

Episode #4-17 released on January 12, 2014

Vinyl, was once the media of choice for music, then came along the cassette, and for a while, everything was good, then came the Compact disk and that brought forth a new age in storage and media. Today's topic of choice, the optical drive, and all its components. I'll be explaining how this common and disappearing technology works, and at the end of this episode, I'll be offering my predictions on this technology.

What is an optical disk drive and what is it for?

An optical disk drive is a disk drive that reads optical media with a laser or an electromagnetic wave within or near the visible light spectrum while retrieving or writing data to or from optical media disks.

What kinds of optical disk drives are available to the consumer?

The consumer currently has access to Compact disks, Digital Video disk, and Blu-ray disks drives, in either read only, writable, or rewritable formats.

How does an optical drive work?

Currently, optical drives are available with a slot, tray-based, or top-loading optical drive bay. Tray-based and slot optical drives require more rotors to either slide out the tray, or push out the disk. Most top-loading drives only require the linear and horizontal rotational rotors to read the optical disks.

Now, what allows us to have our optical disks read is a neat optical laser assembly that allows the lens to both read, and write in some models. It has vertical focusing capability and it can move left to right in related directionality to the disk to align itself with the data track on the optical media. This allows the lens to correct for positional changes in 3 dimensions, probably related to the uneven flatness of some optical disks.

The spinning rotor, in some models, can operate in a way that slows down the spin of the disk the closer to the center it is, to allow for a consistent bitrate required for real time streaming of media. This was normally done for older optical drives while reading music CDs. Newer devices will buffer the extra information instead which is why later CD and Mp3 players using optical disks skipped less than their predecessors.

Another detail, many Blu-ray drives, in order to be backwards compatible, contain two different types of lens, because the normal laser used to read CDs and DVDs, cannot read a Blu-ray disk. A dedicated Blu-ray lens is required to read and write Blu-ray optical media.

How much space is available to each optical media type?

The original universal disk, the compact disk, or CD for short had a normal storage capacity of 640 or 700 megabytes, depending on the type bought. The typical digital video disk, or DVD has a total capacity of 4.7 gigabytes for a single layer, and the newer Blu-ray has a storage capacity of 25GB, 50 GB or 100GB for 3-layer disks. 25GB, the normal Blu-ray disk, is considered a lot for some people, but that is quickly being shown not to be the case, when we consider that we can now purchase USB3 terabyte flash drives, which operate faster.

What is the format used for each of the different available optical media available to the consumer?

Now, we all know FAT and NTFS because many of us use computers. We don't usually ask what format a disk uses, after all, some of us must presume that it is the same format as our hard drive. This is not true. The CD and DVD file system standard is known as Joliet or ISO 9660. The format for Blu-ray is known as Universal Disk Format (UDF) 2.50, also known as ISO/IEC 13346 and ECMA-167. Don't worry if you don't know what those number mean, ISO is short for International Standards Organization, and the numbers are the numbers related to various standards approved by the International Standards Organization.

What do I believe will happen to the optical drive in the near and far future, as it stands now?

The optical drive is doomed to vanish from the face of the earth for many valid reasons that many of you may agree with. For one, it requires the disk inside by spinning all the time to read the data on it. Mobile devices get tossed around, which means that as the world becomes more and more mobile, the optical drive becomes more of a bother and less reliable. Optical drives require extra power to be brought to spin and kept spinning. Mobile devices need to have the power to spin these drives to get the data off of them, and batteries are not yet capable of powering such devices for days on end. While many manufactures are content in telling you 11 hours is a long time, the honest truth is, you use your devices more than that, or you do occasionally forget to recharge your device. Optical disks can break, chip or crack, and inserting one in an optical drive can cause the disk to fail severely. Severe failure of the optical disc can damage the drive, or mobile device. Flash devices require less power, can be more reliable, and do not fail as severely or as dangerously as optical media can. It is for those reasons that I personally believe that optical media is doomed.

Host : Steve Smith | Music : Jonny Lee Hart | Editor : Steve Smith | Producer : Zed Axis Productions

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