{"id":106,"date":"2015-09-01T17:38:00","date_gmt":"2015-09-01T17:38:00","guid":{"rendered":"http:\/\/machineryequipmentonline.com\/video-equipment\/uncategorized\/dvdplayback-start-up-routine-and-cddvd-detection\/"},"modified":"2015-09-01T17:38:00","modified_gmt":"2015-09-01T17:38:00","slug":"dvdplayback-start-up-routine-and-cddvd-detection","status":"publish","type":"post","link":"http:\/\/machineryequipmentonline.com\/video-equipment\/dvdplayback-start-up-routine-and-cddvd-detection\/","title":{"rendered":"DVD:Playback start-up routine and CD\/DVD detection"},"content":{"rendered":"<div class=\"ugwrc6a0dbc79acf42\" ><script type=\"text\/javascript\">\n\tatOptions = {\n\t\t'key' : '61e5902552e2353963d8d2f1bd1f4a8f',\n\t\t'format' : 'iframe',\n\t\t'height' : 250,\n\t\t'width' : 300,\n\t\t'params' : {}\n\t};\n<\/script>\n<script type=\"text\/javascript\" src=\"\/\/www.highperformanceformat.com\/61e5902552e2353963d8d2f1bd1f4a8f\/invoke.js\"><\/script><\/div><style type=\"text\/css\">\r\n@media screen and (min-width: 1201px) {\r\n.ugwrc6a0dbc79acf42 {\r\ndisplay: block;\r\n}\r\n}\r\n@media screen and (min-width: 993px) and (max-width: 1200px) {\r\n.ugwrc6a0dbc79acf42 {\r\ndisplay: block;\r\n}\r\n}\r\n@media screen and (min-width: 769px) and (max-width: 992px) {\r\n.ugwrc6a0dbc79acf42 {\r\ndisplay: block;\r\n}\r\n}\r\n@media screen and (min-width: 768px) and (max-width: 768px) {\r\n.ugwrc6a0dbc79acf42 {\r\ndisplay: block;\r\n}\r\n}\r\n@media screen and (max-width: 767px) {\r\n.ugwrc6a0dbc79acf42 {\r\ndisplay: block;\r\n}\r\n}\r\n<\/style>\r\n<h3 align=\"justify\">Playback start-up routine<\/h3>\n<p align=\"justify\">When the tray is closed, or when \u2018playback\u2019 is selected, a start-up routine is initiated. The purpose of the routine is to determine the size of the disc, whether it is a CD or a DVD\/HD DVD (or BD) disc and whether it is a single- or a DL disc and carry out what is known as a \u2018focus search\u2019. The start-up routine will initiate the following steps:  <\/p>\n<blockquote>\n<p align=\"justify\">\u25cf The spindle motor rotates the disk at a relatively high speed.  <\/p>\n<p align=\"justify\">\u25cf The laser beam is directed onto the disc and the reflected beam is detected by the photodiodes to produce the RF signal.  <\/p>\n<p align=\"justify\">\u25cf The sled motor moves the optical head across the disc from the centre towards the circumference and back again, to determine the diameter size and generate a TE signal.  <\/p>\n<p align=\"justify\">\u25cf The two-axis actuator moves the objective lens up and down to obtain a focus, a process known as focus search.<\/p><div class=\"oqoxc6a0dbc79ad0f5\" ><script async src=\"https:\/\/pagead2.googlesyndication.com\/pagead\/js\/adsbygoogle.js?client=ca-pub-0778475562755157\"\n     crossorigin=\"anonymous\"><\/script>\n<!-- 300x600 television-and-video -->\n<ins class=\"adsbygoogle\"\n     style=\"display:inline-block;width:300px;height:600px\"\n     data-ad-client=\"ca-pub-0778475562755157\"\n     data-ad-slot=\"6549443290\"><\/ins>\n<script>\n     (adsbygoogle = window.adsbygoogle || []).push({});\n<\/script><\/div><style type=\"text\/css\">\r\n@media screen and (min-width: 1201px) {\r\n.oqoxc6a0dbc79ad0f5 {\r\ndisplay: block;\r\n}\r\n}\r\n@media screen and (min-width: 993px) and (max-width: 1200px) {\r\n.oqoxc6a0dbc79ad0f5 {\r\ndisplay: block;\r\n}\r\n}\r\n@media screen and (min-width: 769px) and (max-width: 992px) {\r\n.oqoxc6a0dbc79ad0f5 {\r\ndisplay: block;\r\n}\r\n}\r\n@media screen and (min-width: 768px) and (max-width: 768px) {\r\n.oqoxc6a0dbc79ad0f5 {\r\ndisplay: block;\r\n}\r\n}\r\n@media screen and (max-width: 767px) {\r\n.oqoxc6a0dbc79ad0f5 {\r\ndisplay: block;\r\n}\r\n}\r\n<\/style>\r\n<div class=\"nesmu6a0dbc79ad01f\" ><script type=\"text\/javascript\">\n\tatOptions = {\n\t\t'key' : '0c1eb4c533eaedb7b996f49a5a4983a9',\n\t\t'format' : 'iframe',\n\t\t'height' : 300,\n\t\t'width' : 160,\n\t\t'params' : {}\n\t};\n<\/script>\n<script type=\"text\/javascript\" src=\"\/\/www.highperformanceformat.com\/0c1eb4c533eaedb7b996f49a5a4983a9\/invoke.js\"><\/script><\/div><style type=\"text\/css\">\r\n@media screen and (min-width: 1201px) {\r\n.nesmu6a0dbc79ad01f {\r\ndisplay: block;\r\n}\r\n}\r\n@media screen and (min-width: 993px) and (max-width: 1200px) {\r\n.nesmu6a0dbc79ad01f {\r\ndisplay: block;\r\n}\r\n}\r\n@media screen and (min-width: 769px) and (max-width: 992px) {\r\n.nesmu6a0dbc79ad01f {\r\ndisplay: block;\r\n}\r\n}\r\n@media screen and (min-width: 768px) and (max-width: 768px) {\r\n.nesmu6a0dbc79ad01f {\r\ndisplay: block;\r\n}\r\n}\r\n@media screen and (max-width: 767px) {\r\n.nesmu6a0dbc79ad01f {\r\ndisplay: block;\r\n}\r\n}\r\n<\/style>\r\n\n<\/blockquote>\n<h3 align=\"justify\">CD\/DVD detection<\/h3>\n<p align=\"justify\">When the optical pickup head moves across the track, it generates a TE signal. If the TE voltage is low, then the inserted disk is a blue-laser disc; if it is high, it is a CD disc and in the middle, a DVD disc. Longer pits and wider track pitch produce a higher TE voltage.  <\/p>\n<h3 align=\"justify\">Focus search<\/h3>\n<p align=\"justify\">Once the type of disc is determined, focus search begins. At the beginning, the focus servo loop is kept open. The objective lens is moved up and down along an S-curve (Figure 20.23) crossing the full focus point. As it goes towards focus, the RF signal strength increases. When it reaches a specified threshold, determined by the type of the disc, a <i>Focus OK <\/i>(<i>FOK<\/i>) control line goes High and remains High. While the focus crosses the full focus (zero) line, the RF signal strength simultaneously goes to its maxi- mum value and begins to fall again. At this moment, the servo loop is turned on and a focus is established.  <\/p>\n<h3 align=\"justify\">Single\/dual-layer detection<\/h3>\n<p align=\"justify\">The difference between a single and a DL disc is the intensity of the reflected laser beam. A single-layer disc is 100% reflective while the first layer (layer 0) of a DL disc is only partially reflective. This is identified by  <\/p>\n<p align=\"justify\"><a href=\"http:\/\/lh3.googleusercontent.com\/-YrzJHoKTtyU\/VeXii6ZXTMI\/AAAAAAAB6aI\/GiIGOqkEyGs\/s1600-h\/Television-and-Video-Technology-0136.jpg\"><img decoding=\"async\" loading=\"lazy\" style=\"background-image: none; border-right-width: 0px; margin: 0px auto; padding-left: 0px; padding-right: 0px; display: block; float: none; border-top-width: 0px; border-bottom-width: 0px; border-left-width: 0px; padding-top: 0px\" title=\"Television and Video Technology-0136\" border=\"0\" alt=\"Television and Video Technology-0136\" src=\"http:\/\/lh3.googleusercontent.com\/-r9wHluVGaxI\/VeXikkmSMVI\/AAAAAAAB6aQ\/RjI4H8R4IMA\/Television-and-Video-Technology-0136%25255B2%25255D.jpg?imgmax=800\" width=\"302\" height=\"228\" \/><\/a>  <\/p>\n<p align=\"justify\">what is known as the pull-in (PI) signal. The PI signal is obtained during the process of the focus search. A high PI signal indicates a highly reflective surface and thus a single-layer disc. Alternatively, a low PI indicates a DL DVD disc.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Playback start-up routine When the tray is closed, or when \u2018playback\u2019 is selected, a start-up routine is initiated. The purpose of the routine is to determine the size of the disc, whether it is a CD or a DVD\/HD DVD (or BD) disc and whether it is a single- or a DL disc and carry [&hellip;]<br \/><a href=\"http:\/\/machineryequipmentonline.com\/video-equipment\/dvdplayback-start-up-routine-and-cddvd-detection\/\" class=\"more-link\" >Continue reading&#8230;<\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[1],"tags":[],"aioseo_notices":[],"views":688,"_links":{"self":[{"href":"http:\/\/machineryequipmentonline.com\/video-equipment\/wp-json\/wp\/v2\/posts\/106"}],"collection":[{"href":"http:\/\/machineryequipmentonline.com\/video-equipment\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/machineryequipmentonline.com\/video-equipment\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/machineryequipmentonline.com\/video-equipment\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/machineryequipmentonline.com\/video-equipment\/wp-json\/wp\/v2\/comments?post=106"}],"version-history":[{"count":0,"href":"http:\/\/machineryequipmentonline.com\/video-equipment\/wp-json\/wp\/v2\/posts\/106\/revisions"}],"wp:attachment":[{"href":"http:\/\/machineryequipmentonline.com\/video-equipment\/wp-json\/wp\/v2\/media?parent=106"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/machineryequipmentonline.com\/video-equipment\/wp-json\/wp\/v2\/categories?post=106"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/machineryequipmentonline.com\/video-equipment\/wp-json\/wp\/v2\/tags?post=106"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}