摘要:
An optical disc used for storing content includes a theft control area selected to render the disc unreadable. The disc must be exposed to radiation of a specific wavelength before it can be read by a regular device. The theft control area may include an area that contains data that instructs the device not to read the disc. This area includes a coating that changes its optical characteristics when exposed to the radiation. The material could be radiochromic or thermochromic. Alternatively, the theft control area includes an RFID device that includes an element that is radiation sensitive. In this embodiment, when the disc is irradiated, the element changes its electrical characteristics.
摘要:
A double-sided optical disc, such as a DVD-18 disc, is formed with data tracks on each layer. The tracks on one side are oriented along one spiral while the tracks on the other side are oriented along a second spiral, the two spirals being oriented in opposite directions as viewed from the respective sides. A player with two laser read heads is provided for reading the disc. Each laser read head is disposed adjacent to a respective disc side. The data is read from the two sides, either in sequence from one side and then the other, simultaneously, or in some alternating fashion.
摘要:
A player is provided that is capable of playing discs of either a first or a second configuration. Both types of discs can be double-sided optical discs formed with data tracks. In one configuration, the tracks on one side follow one spiral while the tracks on the other side follow a second spiral, the two spirals being oriented in opposite directions as viewed from the respective sides, and therefore being mirror images of each other. This allows data to be read by a player seamlessly from both sides of the disc without changing the direction of rotation of the disc. In the other configuration, the tracks follow identical spirals. The disc is then rotated in one direction for one side and the other direction for the other side.
摘要:
A double-sided optical disc, such as a DVD-18 disc, is formed with data tracks on each layer. The tracks on one side are oriented along one spiral while the tracks on the other side are oriented along a different spiral, the two spirals being oriented in opposite directions as viewed normally from the respective sides. This allows data to be read by a player seamlessly from either side of the disc without changing the direction of rotation of the disc while the data is being read. The player determines whether a newly inserted disc is oriented properly and, if necessary, the direction of the disc rotation is reversed.
摘要:
Double-sided optical discs, such as a DVD-18 disc, are mass produced with data tracks on each layer. The tracks on one side of the discs are oriented along one spiral while the tracks on the other side are oriented along a different spiral, the two spirals being oriented in opposite directions as viewed from the respective sides, so that they are mirror images of each other. This allows data to be read by a player seamlessly from either side of the disc without changing the direction of rotation of the disc while normal data reading is proceeding. The process for making the discs includes forming master discs corresponding to the data layers and using these master discs to produce molded optical discs.
摘要:
A double-sided optical disc, is formed with data tracks. The tracks on one side follow one spiral while the tracks on the other side follow a second spiral, the two spirals being oriented in opposite directions as viewed from the respective sides, and therefore being mirror images of each other. This allows data to be read by a player seamlessly from both sides of the disc without changing the direction of rotation of the disc.
摘要:
A double-sided optical disc, such as a DVD-18 disc, is formed with data tracks on each layer. The tracks on one side are oriented along one spiral while the tracks on the other side are oriented along another spiral, the two spirals being oriented in opposite directions as viewed from the respective sides, so that they are mirror images of each other. This allows data to be read by a player seamlessly from either side of the disc without changing the direction of rotation of the disc while normal data reading is proceeding. An optical disc drive is provided with an opening to accept the disc. The drive is incorporated into an entertainment device, a desktop PC, a mobile computing device, a PC tablet, etc. The disc drive includes two heads, one disposed on an inner wall of the drive facing the disc, and the other is disposed on a tray moving in and out of the opening.
摘要:
A double-sided double-layer optical disc for storing digital programs, such as a DVD-18 disc, is formed with data tracks on each layer. The tracks on one side are oriented along one spiral while the tracks on the other side are oriented along a different spiral, the two spirals being oriented in opposite directions as viewed from the respective sides, so that they are mirror images of each other. This allows data to be read by a player seamlessly from both sides of the disc without changing the direction of rotation of the disc while normal data reading is proceeding. A disc writer is provided with two heads that are arranged to write data on the respective sides of a disc. The two heads write data streams sequentially or simultaneously.
摘要:
A double-sided optical disc, is formed with data tracks. The tracks on one side follow one spiral while the tracks on the other side follow a second spiral, the two spirals being oriented in opposite directions as viewed from the respective sides, and therefore being mirror images of each other. This allows data to be read by a player seamlessly from both sides of the disc without changing the direction of rotation of the disc.
摘要:
A double-sided optical disc, such as a DVD-18 disc, is formed with data tracks on each layer. The tracks on one side are oriented along one spiral while the tracks on the other side are oriented along a second spiral, the two spirals being oriented in opposite directions as viewed from the respective sides, so that they are mirror images of each other. This allows data to be read by a player seamlessly from either side of the disc without changing the direction of rotation of the disc while normal data reading is proceeding. The disc also includes rotational indicia that is detected by the player and used to determine the direction of rotation for the disc that will allow a read head to read program data from the disc.