Compact disc or DVD-blank is marked by means of lasers or mechanically in three different places arbitrarily, according to random principle whereby CD or DVD-blank, after marking, must be different from each other
摘要
<p>Compact disc (CD) or DVD-blank is marked by means of lasers or mechanically in three arbitrarily different places, according to the random principle. The CD or DVD-blank must differ from each other after marking. Each marked CD or DVD-blank is unique. The coordinates of marked places are implemented in a software.</p>
