摘要:
An optical disc includes a reflective film formed on concave and convex marks after the concave and convex marks are synchronized with the integral multiple of a channel bit length and formed in accordance with modulated main information. Thereafter, continuous or intermittent laser light synchronized with the integral multiple of the channel bit length is irradiated at intervals longer than the longest one of the concave and convex marks in accordance with a spiral track formed in a circumferential direction of the concave and convex marks, whereby an optical characteristic of the reflective film is changed to form a recordable mark and sub-information necessary to reproduce the main information is recorded in a superimposition manner.
摘要:
Sub-information necessary to reproduce main information is recorded without deteriorating the reading accuracy of the main information, so that the illegal duplication of an optical disc is prevented. An optical disc 1 is produced by forming a reflective film 1L on concave and convex marks MK after the concave and convex marks MK synchronized with the integral multiple of a channel bit length are formed in accordance with modulated main information. Thereafter, continuous or intermittent laser light synchronized with the integral multiple of the channel bit length is irradiated at intervals longer than the longest one of the concave and convex marks MK in accordance with a spiral track formed in a circumferential direction of the concave and convex marks MK, whereby an optical characteristic of the reflective film 1L is changed to form a recordable mark SMK and sub-information necessary to reproduce the main information is recorded in a superimposition manner.
摘要:
An optical disc includes a reflective film formed on concave and convex marks after the concave and convex marks are synchronized with the integral multiple of a channel bit length and formed in accordance with modulated main information. Thereafter, continuous or intermittent laser light synchronized with the integral multiple of the channel bit length is irradiated at intervals longer than the longest one of the concave and convex marks in accordance with a spiral track formed in a circumferential direction of the concave and convex marks, whereby an optical characteristic of the reflective film is changed to form a recordable mark and sub-information necessary to reproduce the main information is recorded in a superimposition manner.
摘要:
An optical disc includes a reflective film formed on concave and convex marks after the concave and convex marks are synchronized with the integral multiple of a channel bit length and formed in accordance with modulated main information. Thereafter, continuous or intermittent laser light synchronized with the integral multiple of the channel bit length is irradiated at intervals longer than the longest one of the concave and convex marks in accordance with a spiral track formed in a circumferential direction of the concave and convex marks, whereby an optical characteristic of the reflective film is changed to form a recordable mark and sub-information necessary to reproduce the main information is recorded in a superimposition manner.
摘要:
An optical disc (101) to and from which information can be reproduced and recorded by laser irradiation is provided with a first recording layer (102) and a second recording layer (104). The first recording layer (102) has a first recording mark (103) that is formed in a spiral track. The second recording layer (104) is behind or in front of the read-side surface of the first recording layer (102), and neither a wobble track nor a track for reproducing or recording information by laser irradiation is formed on the second recording layer (104). On the second recording layer (104) are formed, by laser irradiation, a second recording mark (105) that is positioned in the radial direction of the optical disc according to a predetermined position on the spiral track of the first recording layer. The optical disc (101) ensures the secrecy of the copyright protected information that is recorded thereto and the copyright protection function of the optical disc (101), and is resistant against illegal copying.
摘要:
An optical disc (101) to and from which information can be reproduced and recorded by laser irradiation is provided with a first recording layer (102) and a second recording layer (104). The first recording layer (102) has a first recording mark (103) that is formed in a spiral track. The second recording layer (104) is behind or in front of the read-side surface of the first recording layer (102), and neither a wobble track nor a track for reproducing or recording information by laser irradiation is formed on the second recording layer (104). On the second recording layer (104) are formed, by laser irradiation, a second recording mark (105) that is positioned in the radial direction of the optical disc according to a predetermined position on the spiral track of the first recording layer. The optical disc (101) ensures the secrecy of the copyright protected information that is recorded thereto and the copyright protection function of the optical disc (101), and is resistant against illegal copying.
摘要:
An optical disc recording apparatus (10) is provided with a tracking servo (13) for tracking a spiral track of concave and convex marks, an analog signal processor (14) for extracting a reproduction signal corresponding to the concave and convex marks, a digital signal processor (15) for extracting a channel clock synchronized with a channel bit length of the concave and convex marks, and a sub-information recording section (30) for recording sub-information by irradiating laser light based on the tracking to the spiral track. The sub-information recording section (30) records all the sub-information by repeating a process of recording a part of the sub-information by discretely irradiating laser light at a specified interval and with a specified frequency in synchronism with a channel clock by one tracking to form recordable marks on a reflective film a plurality of times. By this construction, a tracking control to the concave and convex marks can be stably executed and the sub-information can be stably recorded.
摘要:
A management server has: an identification-information reproducing unit which reproduces identification information from an optical disk; an invalid-unit intrinsic-information registration section which registers the reproduced identification information; and a restriction-lifting decision section which decides, on the basis of the registered identification information and unit intrinsic information given intrinsically to every recording unit, whether the identification information can be recorded on a master optical disk. A recording unit has: a communication section which notifies the management server of the unit intrinsic information on this recording unit; an identification-information generation section which generates the identification information recorded on the master optical disk; an identification-information recording section which records the identification information on the master optical disk; and a restriction lifting section which controls the operation of the identification-information generation section and the identification-information recording section on the basis of the decision result of the restriction-lifting decision section.
摘要:
On an optical disc, main information to be decrypted using sub information is recorded by arranging concave or convex recording marks in a spiral track and a reflective film is formed on the recording marks. First sub information is recorded as being superimposed on the main information by shifting or deforming the recording marks or altering a pattern of the recording marks. Second sub information is recorded as being superimposed on the main information by changing a reflectivity of the reflective film formed on the recording marks. The first sub information and the second sub information are recorded in an area from which the first sub information and the second sub information are to be read simultaneously. The second sub information is recorded in a manner that the second sub information is associated with the first sub information. The first sub information and the second sub information are associated with each other, and improve resistance to unauthorized copying by prohibiting content information from being read unless both the first sub information and the second sub information are read. The first sub information and the second sub information are recorded in the same area, and prevent the time taken for reading sub information from increasing.
摘要:
A server device without a means for accessing an IC memory included in a data storage medium can check whether or not a data storage medium includes an IC memory. A portable optical disc medium (100) includes an IC memory (106) accessible through proximity wireless communication and a computer-readable recording part (101). The recording part (101) includes a user-data area (104) in which content data is recorded and a disc management information area (103) in which information for management of recording and reproducing the content data. In the disc management information area (103), medium identification information identifying the optical disc medium (100) and presence indication information indicating that the optical disc medium (100) includes presence of the IC memory (106) in a manner such that the presence indication information does not allow changing.