Microboards Technology II Manual De Usuario

    

                                                                        Orbit II Disc-to-Disc Copier Reference Manual – Revision I

 

 

6 

 

 
Although you cannot select CD-R media based upon color alone, there is a correlation between 
“reflectivity” and media performance.  The CD or CD-R drives that read the CD-Rs you duplicate project a 
laser beam through the thickness of the plastic disc.  The laser beam is reflected by the metallic coating on 
the back of the CD-R and returns through the thickness of the plastic to the drive’s optical detector.  For 
CDs, the minimum reflectivity specification is 70%.  CD-Rs are permitted to have slightly less reflectivity. 
Their minimum specification is 65%.  Hold a commercial CD up to a light.  Place your fingers a few inches 
behind the CD.  You will typically not be able to see the shadow of your fingers looking through a CD.  For 
CD-Rs to work in a large number of CD or CD-R drives they should have similar reflectivity and opacity.  
Reflectivity and opacity become increasingly important as read drive speeds increase.  A modern 48x read 
drive requires more reflectivity than an 8X read drive.  It is best to avoid CD-Rs that are less reflective 
and/or opaque than the CD-Rs you are using as your reference sample. 
 
CD-RW media has about ½ of the signal strength of CD-R media, even though they may appear to be 
highly reflective.  The lower signal strength of CD-RW media is one of the reasons they may not work in 
older CD-Audio, CD-ROM, or CD-R Drives.  Recognizing the need for CD-RW compatibility, Compact Disc 
media and drive manufacturers met and established a specification that is intended to assure CD-RW 
interchange capability.  Products compliant with this new specification carry a “MultiRead” qualified label on 
their faceplate, or in their product manual.  CD-RW media should only be used in CD-Audio, CD-ROM, CD-
R, or DVD Drives that have MultiRead certification.