CD+Player

=CD Player = ATassonitoc

Purpose
An electrical device that takes audio files from a compact disc and plays them through ports connected to speakers or headphones.

Energy
Portable CD players use batteries or are connected to a power source through ports.

Laser
A CD holds music and other files in digital form. The information is then stored and represented by 1s and 0s. The 1s and 0s are little tiny bumps and flats on the surface of the disc. To read these bumps and flat areas you need a laser. The laser beam scans over the track if the laser senses a flats then it’s a 1 and the light is reflected to the optical sensor. If the laser senses a bump then it’s a 0 and the light is not reflected but its bounced away from the optical sensor. The bumps on the CD are what make the sound which is then sent through the ports of your headphones which comes out with your music that you stored.

Controls
*Not in all CD players.
 * Ports: Within CD players there are ports that connect to powered or unpowered speakers, headphones, or possibly the electrical supply.
 * Drive Motor: The drive motor rotates the CD between 200 and 500 revolutions per minute
 * Lens System: The lens system reads the information off of the CD through a laser beam, mainly produced through a laser diode. The laser reads the information on the CD and reflects it back to a sensor. The sensor reads the information and plays it back accordingly. The lens system is either on a swing-arm mechanism, which moves at the end of an arm and is originally designed by Phillips, or a radial mechanism, which has the lens move on a radial rail and was originally designed by Sony. The radial mechanism is most common because it is cheaper but the swing-arm mechanism prevents skipping and lasts longer.
 * Tracking Mechanism: The tracking mechanism moves the lens system along the code on the CD
 * Tray: The tray either slides out horizantally, vertically, or just has the CD be slided in. When the CD is slided in, it is known as slot loading.
 * Interface: The interface contains the main buttons and display of the CD player. The buttons include Play/Pause, Stop, Fast Forward/Skip Forward, Rewind/Skip Backwards, and disk selection in CD changers. The display shows the track number, the track time, and the disk number on CD changers.
 * * <span style="background-color: #ffffff; color: #000000; font-family: Verdana,Geneva,sans-serif;">CD Changers: CD players that can contain more than one CD.

<span style="font-family: Verdana,Geneva,sans-serif;">Materials
<span style="font-family: Verdana,Geneva,sans-serif;">Many CD players are encased in plastic or steel.

<span style="font-family: Verdana,Geneva,sans-serif;">Science
<span style="font-family: Verdana,Geneva,sans-serif;">Either a vertical, horizantal, or a slot loader take the CD. Then you press the play button and that starts the drive motor. Once the drive motor has been started, the tracking mechanism then moves the lens system over the CD. Once the lens system is over the CD, a laser beam from a laser diode reads the information off of the CD and sends it through ports to either speakers or headphones so that you can hear the information on the CD.

<span style="font-family: Verdana,Geneva,sans-serif;">Design
<span style="font-family: Verdana,Geneva,sans-serif;">A typical CD player has an interface which contains the buttons and display. Also on the outside there are ports for the headphones and a port to connect to speakers. The on the inside there is a drive motor, a lens system, and a tracking mechanism to turn the CD and read the information.



<span style="font-family: Verdana,Geneva,sans-serif;">Evolution
<span style="font-family: Verdana,Geneva,sans-serif;">The only real evolution throughout this device would have to be the tray and the lens system. Tray: First the tray was just something that slid out to take in the CD. Then came the vertical tray, which was never really put into action but was used in Japanese prototypes. Then there was the top loading tray which would have a lid open up, the CD would be put in, then the lid would be closed. Next came the the sliding tray which was a tray that slid out but when the CD was in the player, it would automatically play. Then came the trays with dampers; the dampers would reduce distortion on the CD. And last came the slot tray which didn't have a tray that came out but instead the CD would be slid into the player. Lens System: The lens system first started out with a swing-arm mechanism to move it around and then moved on to the radial mechanism which had the lens moving on a radial rail. Both are still being used.

<span style="font-family: Verdana,Geneva,sans-serif;">Competitors
<span style="font-family: Verdana,Geneva,sans-serif;">iPods: iPod Nano, iPod Mini, iPod Touch, iPod Nano-Chromatic MP3 players

<span style="font-family: Verdana,Geneva,sans-serif;">Partners
<span style="font-family: Verdana,Geneva,sans-serif;">Radio Speakers: Subwoofers, Sound Bar, Stereo Amplifiers Headphones: Headphones, Headphones (Noise Canceling)

<span style="font-family: Verdana,Geneva,sans-serif;">Siblings
<span style="font-family: Verdana,Geneva,sans-serif;">DVD Players Car Stereos