Optical Drives

 

 

Hello and welcome back to Tomexplace.

 

As I promised before for those who are reading my posts that I will make a new post every week, here is another.

In this post, I will write about the Optical Drives.

  

So what's  Optical Drive?

An Optical drive is that type of drive that reads and writes data into optical discs, the discs you put into your computer, like CD, DVD, Blu-Ray.

This drive allows user to write, edit and delete data from these discs. When you put a CD into your computer, the Optical Drive reads it. 

Optical Drive is also known as the Optical Disk Drive (ODD).

You can find optical drives not only in computer's, optical drives are also included in things like, Playstation, xbox, car audio systems, DvD players, everywhere where the CD's are necessary.

 

 Optical Drives are dying

Optical drives have been important part of the computers for a long time, but now they are slowly dying, because you can download almost everything from the internet, and CD's are getting replaced with the Flash Drives. Nowadays some laptops are manufactured without built-in Optical Drives.

In my opinion, I believe, that soon we wont use CD's and DvD's anymore, the flash Drives are already strating to replace Optical Drives and soon we will forget about them.

 

So what's the point of making this post?

 

You may ask, Then whats the point of writing about Optical Drives if they are dying? What's the point of even knowing about them?

Well, we are still using them, they are still in the market, and there are computer's in the market with built-in Optical Drives. There still is game consoles and car audio systems which are using optical drives.


We somethimes need to acces older media, and because the CD's and DVD's are read only, it can be good archival format. Some programs still require them for emergency boot tools.

 

More about the Optical Drives

    

On desktop computers optical drive is in the size of a small book. On the front of the drive you can find small open / close button that ejects CD, or opens the slot for you so you can put the CD into your computer. 

 

The sides of the optical drive have pre-drilled, threaded holes for easy mounting in the 5.25 inch drive bay, in the computer case. The optical drive is mounted so the end with the connections faces inside the computer and the end with the drive bay faces outside. The back of the optical drive contains a slot for a cable that connects to the motherboard.

 

For laptops it's smaller, but the functions are the same.

How the Optical Drive works?

Basically, when you insert the disc into the drive, the motor spins the disc really fast, while the laser reads the data from the disc. When you put the disc into the drive you can hear loud noise, its because the drive is spining the disc.

Optical Drive uses a laser to read data from the disc and write data to disc. A laser means an electromagnetic wave with specific wavelength. Different types of discs require different wavelengths. 

There are three main components of the optical drive, a laser, leans, and a photodiode.

The laser reads and writes data to disc, 

leans guides the laser across the disc's surface, 

photodiode detects the reflection light from the disc.

For different types of discs laser uses different wavelenghts. A CD player uses wavelenght of 780 nanometers (nm), this is in the infrared light range. 

DvD players uses wavelenghts of 650 nm range. 

Blu-Ray players use a much lower wavelength something like 450nm.

  

Read Only Media (ROM)

When you buy a new CD or DvD disc, you may see that there is a label on the disc cover, like, DvD-RW, DvD-ROM, DvD-Rs or CD-RW, CD-ROM, CD-Rs. It's because not all the discs are manufactured for the same purposes.

Two letters at the end can describe what kind of disc it is and how you can use it. Like, RW means rewriteable, ROM means read only media, Rs means recordable. 

So if you have a common sense, you can understand that the read only media (ROM) means that the disc is only readable, and you can't record anything to it. 

Usually these are the types of discs that software is written on by manufacturer, also original movie, games and music discs.

The manufacturer will create the disc by embedding pits called grooves, on the disc’s surface. 

When you insert the disc into the optical drive, a reading laser shines on the disc. The light is reflected and detected by the photodiode which then translates the data into a form that the computer can understand and display.

 (R) discs

Optical Drive can also record media to discs, not only read them, for this you need a specific recordable discs like CD-Rs, DvD-Rs, BD-Rs. 

BD stands for Blu-Ray discs, I dont know why they are called BD, it could be better if they would be called BR, that would make more sense, but it's how it is BD will always stand for Blu-Ray.

 

(R) disc means, that the disc is manufactured only for recording. When you buy it, it's empty, there is no data on it. For writing files into disc you will need Optical Drive that's capable for recording. Well, it's not that much important anymore, nowadays every optical drive can record.

Anyways, if you aren't sure about your ODD, then check the cover of your optical drive, you can see the label on your computer's optical drive cover, the place where you put a CD's into your computer.  

In picture bellow you can see the labels on optical drive. This drive supports BD, its DvD and CD rewriteable, basically it can do anything you will ever need.
 

So, to write data into the disc you need an optical drive that's capable for recording, DvD-Rs, CD-Rs or BD-Rs type of disc and a software to do the work for you. 
The most popular is called Nero, but there are many kind of CD recording softwares. Usually they are built-in your operating system, if not, you can just download some of them for free.



When you write files into the disc, a laser melts organic dyes on the disc's surface, and embeds grooves into the surface. Then, when the data is recorded on the disc, the disc will function like ROM disc, it will become Read Only Media. You wont be able to delete anything from the disc, its recorded to be there for ever.

RW

RW stands for rewriteable, it means that you can rewrite files on the disc over and over. For example, you have a DvD-RW disc and there's a movie recorded into the disc. You can download another movie and record it to the same disc.

You wont be able to watch the old movie from this disc, but you will be able to watch the new movie you just recorded. You can do this over and over, how many times you wish.

Rewriteable discs are aviable for CD-RW, DvD-rw, BD-RW. These discs are different than R and ROM. The surface of these discs are made of a special crystalline alloy that enables data to be written on its surface over and over.

Data is embedded into the disc on grooves that reflect the laser differently.

Then, the photodiaode is able to distinguish between different reflections and can display the correct information.

About the discs

You may ask, why there is three variations of discs like CD, DvD, BD?

There are many reasons for that but basically, they all work in the same way. the main difference is capacity of how much you can record.

The first and the oldest one is CD - Compact Disc. The CD has the lowest capacity of 700 MB and they are the cheapest ones.

The next one is DvD or Digital Versatile Disc, it can hold 4.7GB. Because of their higher capacity they are ideal for storing movies and data backup.

The largest one is Blu-Ray, it can hold 25 GB.

 

Dual Layer

Dual layer is double sided DVD and it can apply only to BD and DVD.

Dual layer is more commonly called Double Layer. Dual layer technology provides two individual recordable layers on a single sided DVD or BD disc. The disc has two layers, basically, it doubles the discs memory.

For example, The simple DVD disc can have 4.7 GB free space, the DVD with double layer can have it doubled, so it means DVD with double layer can have 8.54 GB. Same with BD, single layer BD contains 25 GB but in double layer, 50 GB of memory. 

To take advantage of dual layer technology when recording DVDs, you must use a dual layer enabled DVD burner and dual layer DVD media. 

DL will always stand for dual layer, double layer. 

Dual layer discs are DVD+R DL or BD+R DL. Double layer discs are recordable only (R DL).

Thats it, the basic concepts of the optical drives and discs.

Final thoughts

This post won't be usefull in the near future, but still we are using the optical drives, you can still buy movies, games, music into CD's.


In my opinion, in like 5 or 10 years we wont use this technology anymore. Right now the optical drives aren't important as much as 5 years ago, the flashdrives are replacing them, soon flashdrives will take over discs.


Even now you don't really need to use them as much as before, you can survive without them, its old technology. But it's good to know about the thing right now, because we are still using it.


There's a saying "The old things are the gold things"
I will make another post about the flashdrives in the future.




Ight, thanks all for reading, if there is anyone or not, lol, not giving a damn about it haha! If there is someone, follow me or check back later, there will be more posts coming soon. Regards "Tomex".