Abstract: An optical information recording medium has a first information recording layer (20) and a second information recording layer (40) each of which includes (i) a group of pre-pits (31, 51) constituting marks (32, 52) and spaces (33, 53) and (ii) a super-resolution film (23, 43), the marks (32, 52) and the spaces (33, 53) having different lengths, an average length of a smallest mark that is smallest in length and a smallest space that is smallest in length being less than or equal to a resolution limit of a reproduction optical system for reproducing information recorded on the first information recording layer (20) and the second information recording layer (40), the group of pre-pits (31, 51) being formed so that a push-pull signal for the reproduction optical system to reproduce the information recorded by the group of pre-pits is negative in polarity. This provides an inexpensive and high-capacity multilayer optical information recording medium based on a super-resolution technology.

Abstract: An optical information recording medium has a first information recording layer (20) and a second information recording layer (40) each of which includes (i) a group of pre-pits (31, 51) constituting marks (32, 52) and spaces (33, 53) and (ii) a super-resolution film (23, 43), the marks (32, 52) and the spaces (33, 53) having different lengths, an average length of a smallest mark that is smallest in length and a smallest space that is smallest in length being less than or equal to a resolution limit of a reproduction optical system for reproducing information recorded on the first information recording layer (20) and the second information recording layer (40), the group of pre-pits (31, 51) being formed so that a push-pull signal for the reproduction optical system to reproduce the information recorded by the group of pre-pits is negative in polarity. This provides an inexpensive and high-capacity multilayer optical information recording medium based on a super-resolution technology.

Abstract: An optical information recording medium has a first information recording layer (20) and a second information recording layer (40) each of which includes (i) a group of pre-pits (31, 51) constituting marks (32, 52) and spaces (33, 53) and (ii) a super-resolution film (23, 43), the marks (32, 52) and the spaces (33, 53) having different lengths, an average length of a smallest mark that is smallest in length and a smallest space that is smallest in length being less than or equal to a resolution limit of a reproduction optical system for reproducing information recorded on the first information recording layer (20) and the second information recording layer (40), the group of pre-pits (31, 51) being formed so that a push-pull signal for the reproduction optical system to reproduce the information recorded by the group of pre-pits is negative in polarity. This provides an inexpensive and high-capacity multilayer optical information recording medium based on a super-resolution technology.

Abstract: An optical information recording medium has a first information recording layer (20) and a second information recording layer (40) each of which includes (i) a group of pre-pits (31, 51) constituting marks (32, 52) and spaces (33, 53) and (ii) a super-resolution film (23, 43), the marks (32, 52) and the spaces (33, 53) having different lengths, an average length of a smallest mark that is smallest in length and a smallest space that is smallest in length being less than or equal to a resolution limit of a reproduction optical system for reproducing information recorded on the first information recording layer (20) and the second information recording layer (40), the group of pre-pits (31, 51) being formed so that a push-pull signal for the reproduction optical system to reproduce the information recorded by the group of pre-pits is negative in polarity. This provides an inexpensive and high-capacity multilayer optical information recording medium based on a super-resolution technology.

Abstract: An optical information recording medium (1) includes on a substrate (50), a ROM layer (20), a RE layer (40), an intermediate layer (30) separating the ROM layer (20) and the RE layer (40), and a light transmitting layer (10) provided farthest from the substrate (50). The RE layer (40) is an information recording layer provided most farthest from the light transmitting layer (10), and is a recording layer of BCA recorded in a format easily determinable as compared to an information recording format used in the ROM layer (20), and antifouling property of a surface of the light transmitting layer (10) is set based on the RE layer (40). This makes it easy for the recording and reproducing apparatus to confirm a disc type, allows for sharing one recording and reproducing apparatus with other types of optical discs, and simplifies the disc production.

Abstract: An optical information recording medium (1) includes on a substrate (50), a ROM layer (20), a RE layer (40), an intermediate layer (30) separating the ROM layer (20) and the RE layer (40), and a light transmitting layer (10) provided farthest from the substrate (50). The RE layer (40) is an information recording layer provided most farthest from the light transmitting layer (10), and is a recording layer of BCA recorded in a format easily determinable as compared to an information recording format used in the ROM layer (20), and antifouling property of a surface of the light transmitting layer (10) is set based on the RE layer (40). This makes it easy for the recording and reproducing apparatus to confirm a disc type, allows for sharing one recording and reproducing apparatus with other types of optical discs, and simplifies the disc production.

Abstract: A single disc is configured to deal with both HD DVD information and DVD information. This invention has the following basic elements (1) a single-sided dual layer optical disc where a light transmission layer, a first recording layer accessed with a first laser beam, an space layer, and a second recording layer accessed with a second laser beam are arranged in that order in the direction in which a laser beam enters, (2) the areal recoding density of the second recording layer is three times or more that of the first recording layer, (3) information indicating that the second recording layer has been formed is formed in the first recording layer, and (4) information indicating that the first recording layer has been formed is formed in the second recording layer.

Abstract: An optical disc manufacturing apparatus (46) recording a BCA code constituted by plural marks and including a secret code which is modulated in a range capable of recognizing a position in a radial direction of an optical disc and/or a position in a track direction of the plural marks as the BCA code, a BCA history database (44) storing a history including a correspondence between the BCA code of an optical disc (1a) recording the BCA code and the secret code, and a management center (30) reading the BCA code and the secret code recorded on the optical disc so as to compare both on the basis of input of the correspondence between the BCA code and the secret code stored in the BCA history database (44) are employed, whereby an illegally manufactured optical disc (1z) can be easily found by inspecting the recorded BCA code and secret code.

Abstract: A single-sided dual-layer optical disc comprising an optically transparent layer; a first recording layer accessed by a first laser beam; an intermediate layer; and a second recording layer accessed by a second laser beam, wherein the optically transparent layer, the first recording layer, the intermediate layer, and the second recording layer are sequentially disposed in a laser beam incidence direction, wherein a thickness of the optically transparent layer, which is a distance from a light incident surface to the first recording layer, is 550 to 575 ?m, wherein a thickness of the intermediate layer, which is a distance between the first and second recording layers, is 29 to 47 ?m, and wherein a surface recording density of the second recording layer is at least 3 times that of the first recording layer.

Abstract: An optical disc is based on the following the distance of the light transmission layer from a light incidence plane to the first recording layer is a minimum of 550 ?m. The distance between the first and the third recording layer is a maximum of 72 ?m. The distance between the second and the third recording layer is a minimum of 15 ?m. The distance between the first and the second recording layer is about 31 to 40 ?m. The reflectivities of the first and the second recording layer with respect to the first laser beam are 18% or more, and the ratio between the reflectivities is about 1.15 or less. The areal recording density of the third recording layer is three times or more as high as the areal recording density of the first and the second recording layer.

Abstract: According to one embodiment, an optical disc is the following the distance between a light incidence plane and the first recording layer is a minimum of 550 ?m. The distance between the first and the third recording layer is a maximum of 72 ?m. The distance between the second and the third recording layer is a minimum of 15 ?m. The distance between the first and the second recording layer is about 31 to 40 ?m. The reflectivities of the first and the second recording layer with respect to the first laser beam range from 18 to 27%, and the ratio therebetween is about 1.1 or less. The reflectivity of the third recording layer is below about 6%. The areal recording density of the third recording layer is three times or more as high as that of the first recording layer and the second recording layer.

Abstract: An optical disc manufacturing apparatus (46) recording a BCA code constituted by plural marks and including a secret code which is modulated in a range capable of recognizing a position in a radial direction of an optical disc and/or a position in a track direction of the plural marks as the BCA code, a BCA history database (44) storing a history including a correspondence between the BCA code of an optical disc (1a) recording the BCA code and the secret code, and a management center (30) reading the BCA code and the secret code recorded on the optical disc so as to compare both on the basis of input of the correspondence between the BCA code and the secret code stored in the BCA history database (44) are employed, whereby an illegally manufactured optical disc (1z) can be easily found by inspecting the recorded BCA code and secret code.

Abstract: An optical disc of this invention is configured to be capable of dealing with both information in HD DVD and information in DVD.

Abstract: An optical disc recording medium of the present invention comprises a first substrate (11) having a physically pre-formatted surface; a reflective film (12) formed on the pre-formatted surface of the first substrate (11); a transparent layer (13) with a thickness of 50-430 ?m formed on the reflective film (12); a second substrate (15) composed of transparent material and located at a distance of certain spacing from the transparent layer (13); and a recording layer (14) for hologram recording filled between the transparent layer (13) and the second substrate (15).

Abstract: An optical disc recording medium of the present invention comprises a first substrate (11) having a physically pre-formatted surface; a reflective film (12) formed on the pre-formatted surface of the first substrate (11); a transparent layer (13) with a thickness of 50-430 ?m formed on the reflective film (12); a second substrate (15) composed of transparent material and located at a distance of certain spacing from the transparent layer (13); and a recording layer (14) for hologram recording filled between the transparent layer (13) and the second substrate (15).

Abstract: An optical disc of this invention is configured to be capable of dealing with both information in HD DVD and information in DVD.

Abstract: This invention enables a single disc to deal with HD DVD information and DVD information. An optical disc according to the present invention is basically specified by the following items (1) the optical disc is a single-sided dual layer optical disc, (2) the distance in the light transmission layer from an incidence plane to a first recording layer is 578 to (578+2p) ?m (2p is the maximum value of substrate thickness accuracy), (3) the distance in the space layer between the first recording layer and a second recording layer is (62?2p?2q) to (62?2p) ?m (2q is the maximum value of space layer thickness accuracy), and (4) the areal recording density of the first recording layer is three times or more as high as that of the second recording layer.

Abstract: A single disc is configured to deal with both HD DVD information and DVD information. This invention has the following basic elements (1) a single-sided dual layer optical disc where a light transmission layer, a first recording layer accessed with a first laser beam, an space layer, and a second recording layer accessed with a second laser beam are arranged in that order in the direction in which a laser beam enters, (2) the areal recoding density of the second recording layer is three times or more that of the first recording layer, (3) information indicating that the second recording layer has been formed is formed in the first recording layer, and (4) information indicating that the first recording layer has been formed is formed in the second recording layer.