Asked by: Carola Wever
technology and computing computer peripherals

How does a CD laser work?

Last Updated: 2nd February, 2020

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Inside your CD player, there is a miniaturelaser beam (called a semiconductor diode laser) and asmall photoelectric cell (an electronic light detector). Thelaser (red) flashes up onto the shiny (under) side of theCD, bouncing off the pattern of pits (bumps) and lands (flatareas) on the disc.

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Just so, how does a laser read a CD?

The surface of the CD contains one long spiraltrack of data. The CD drive shines a laser at thesurface of the CD and can detect the reflective areas andthe bumps by the amount of laser light they reflect. Thedrive converts the reflections into 1s and 0s to readdigital data from the disc.

Similarly, how data is stored in CD? CD data are stored as a series of tinyindentations known as “pits”, encoded in a spiral trackmolded into the top of the polycarbonate layer. The areas betweenpits are known as “lands”. CD-ROM capacities arenormally expressed with binary prefixes, subtracting the space usedfor error correction data.

Then, which side of a CD is worse to scratch?

Scratches Are Worse on One Sidethan the Other Pits are closer to the label side of a CD, so ascratch or other damage on the label side is morelikely to result in an error than one occurring on the clearside of the disc.

What can I do with old CDs?

  • Use an old CD as the template for a perfect circle.
  • Cover old CDs with felt and use them as coasters.
  • Use old CDs to catch candle drips.
  • 4. Make artistic bowls from old CDs.
  • Use old CDs as sidewalk or driveway reflectors.
  • Use an old CD as the basis for a kids' craft.
  • Use old CDs as holiday ornaments.

Related Question Answers

Yiran Eckelmann

Professional

How does the CD work?

Just How Do CDs Work? A traditional CD isessentially a time-bound deposit. In exchange for a higher interestrate, you enter into an agreement to let the bank use your moneyfor a fixed period of time. The bank rewards you by paying you ahigher interest rate than it does for a savings account ormoney market account.

Inaya Anikiev

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What is the difference between CD and DVD?

CD, short for Compact Disc, is an optical mediumthat can store digital data. A standard DVD can hold 4.7 GBof data. So DVD is widely used to store large files likevideo and movies. The capacity is the biggest difference betweenCD and DVD.

Ruben Jardin

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How are CDs burned?

CDs are made from an original "master" disc. Themaster is "burned" with a laser beam that etches bumps(called pits) into its surface. A bump represents the number zero,so every time the laser burns a bump into the disc, a zerois stored there.

Dragan Bramon

Explainer

What are the types of CD?

There are three main types: standard manufactured CDs(CD-DA), CD-R recordable and CD-RW rewriteable.
  • Standard manufactured CDs can be played on any CD digital audioplayer.
  • CD-Rs can be played on CD-R machines and many but not all CDdigital audio players.
  • CD-RWs can only be played on CD-RW compatible machines.

Jokin Mommertz

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Sana Morzhitsky

Pundit

How is data stored on a DVD?

Optical data storage is a method ofstoring digital information (1's and 0's) by using light toread the information. Analog information is converted into digitalinformation, which is then encoded onto the disc from the insideedge out. Digital data are encoded by means of pits on therecording layer of the disc.

Dongmei Elert

Pundit

How do I burn a movie onto a DVD?

How to Burn a Movie onto a Blank DVD-R
  1. Click the Windows "Start" button and click "All Programs."
  2. Click the "Burn a CD or DVD" button that displays when theMedia Player software detects the blank DVD-R. Select "Video DVD"from the list of burning options.
  3. Click "Video Library" to choose a video from your list ofmovies.

Krisztina Chandran

Pundit

At what temperature do CDs warp?

The temperature would range between 40 degreesand 70 degrees in the space of a few hours. Now, the data layer ofsome of his CDs looks as if it's being eaten from theoutside.

Ihssane Cser

Pundit

Do CD scratches affect sound quality?

However, a scratched CD can vary. Lightscratches just need buffing and some time with the computer.Medium scratches need something like a motorized buffer anda special wax to even out the data surface, like a "discdoctor" or something like that (have not used it in awhile).

Liviu Nienkirchen

Pundit

Do DVD discs wear out?

With DVD and CD discs, this doesnot happen because of the technical differences between theseformats. Disc drives do not have “heads”in the traditional sense, and are instead read and recorded by ahighly accurate laser. While discs don't “wearout” like magnetic media does but they dodegrade.

Elizabhet Walterscheid

Teacher

Do CDs read from the top or bottom?

However, most people don't realize that the tops ofdiscs are just as prone to damage as the bottom - if notmore so! Although you can physically see the shiny data layer fromthe bottom of a CD-R, it is actually applied to theTOP side of the disc, just under the label.

Soundous Peixeiria

Teacher

Can heat damage DVDs?

Likewise, if exposed to extreme heat, a disccan become warped and unusable. Typically, DVD mediacan withstand 10 to 90 percent relative humidity, and arerated for use in environments ranging from 23 to 131 degreesFahrenheit. But temperatures that slightly exceed those extremeswon't destroy the disc's integrity.

Geertruida Rakowsk

Teacher

Do scratched CDs work?

Scratched CDs can often still work for tworeasons: CIRC on a CD is actually amazingly effective -- itcan perfectly recreate data from a severe scratch or even a hole inthe CD up to 2.5mm across.

Nando Stolzen

Teacher

How long do CDs last?

Among the manufacturers that have done testing, there isconsensus that, under recommended storage conditions, CD-R,DVD-R, and DVD+R discs should have a life expectancy of 100to 200 years or more; CD-RW, DVD-RW, DVD+RW, and DVD-RAMdiscs should have a life expectancy of 25 years ormore.

Yibin Stefanescu

Reviewer

How long does a DVD last?

DVDs that are burned separately, perhaps asbackups, could last anything from 20 years to 200 years.However, read-write (RW) discs should never be used for archiving:they are not as stable and many may not last 15years.

Ferriol Nieden

Reviewer

Do CDs play from the inside out?

ll Compact discs and other optical disc playersread from the inside of the CD out, just the oppositeof a vinyl record. Scratches or other surface damage in this areacan leave the cd completely unplayable. The song tracksbegin just outside the lead-in.

Asmahane Eizagirre

Reviewer

Is CD ROM a storage device?

Short for Compact Disc Read-Only Memory, aCD-ROM is an optical disc that contains audioor software data whose memory is read-only. A CD-ROMDrive or optical drive is the device used to readthem.

Jeno Dietsch

Reviewer

Bilale Fernanda

Supporter

What are the types of CD ROM?

A CD-ROM is a pre-pressed optical compactdisc which contains data. The name is an acronym which isshort for "Compact Disc Read-Only Memory". Computers canread CD-ROMs, but cannot write toCD-ROMs, which are not writable orerasable.