Optical storage medium, optical read/write apparatus, and optical read/write method

An optical read/write apparatus causing a read/write light beam from illuminating means to strike only one side of an optical storage medium including stacked data storage layers each of which is readable/writeable separately from the other layers by means of only a light beam striking one side of the medium, wherein:

• the medium is such that:
• a recordable area of a first data storage layer has adjacent to an end thereof an extended area covering more than an area directly above a recordable area of a second data storage layer in a direction in which the first and second data storage layers are stacked, the first data storage layer being one of the data storage layers which is located closest to a light-striking surface of the medium, the second data storage layer being another of the data storage layers which is located next to the first data storage layer, opposite the light-striking surface;
• the extended area is a pseudo-recording area which is fully prerecorded;
• and the pseudo-recording area stores encryption information by which data is encrypted before being recorded on the optical storage medium, and
• the apparatus comprising:
• encrypting means for encrypting data to be recorded on the optical storage medium using the encryption information stored in the pseudo-recording area;
• and controlling means for controlling the illuminating means so that data is encrypted by the encrypting means before being recorded in any of the data storage layers.

An optical read/write apparatus causing a read/write light beam from illuminating means to strike only one side of an optical storage medium including stacked data storage layers each of which is readable/writeable separately from the other layers by means of only a light beam striking one side of the medium, wherein:

• the medium is such that a recordable area of a first data storage layer has adjacent to an end thereof an extended area covering more than an area directly above a recordable area of a second data storage layer in a direction in which the first and second data storage layers are stacked, the first data storage layer being one of the data storage layers which is located closest to a light-striking surface of the medium, the second data storage layer being another of the data storage layers which is located next to the first data storage layer, opposite the light-striking surface;
• and
• the apparatus comprising:
• identification information storing means for storing identification information which is unique to the optical read/write apparatus and by which the optical read/write apparatus is distinguished from other optical read/write apparatuses;
• and controlling means for controlling the illuminating means so that the optical storage medium holds the identification information in the extended area.

An optical read/write apparatus causing a read/write light beam from illuminating means to strike only one side of an optical storage medium including stacked data storage layers each of which is readable/writeable separately from the other layers by means of only a light beam striking one side of the medium, wherein:

• the medium is such that a recordable area of a first data storage layer has adjacent to an end thereof an extended area covering more than an area directly above a recordable area of a second data storage layer in a direction in which the first and second data storage layers are stacked, the first data storage layer being one of the data storage layers which is located closest to a light-striking surface of the medium, the second data storage layer being another of the data storage layers which is located next to the first data storage layer, opposite the light-striking surface,
• the apparatus comprising:
• encryption information storing means for storing encryption information by which data is encrypted before being recorded on the optical storage medium;
• and controlling means for controlling the illuminating means so that the optical storage medium holds the encryption information in the extended area.

An optical read/write method using an optical storage medium including stacked data storage layers each of which is readable/writeable separately from the other layers by means of only a light beam striking one side of the optical storage medium, wherein:

• the optical storage medium is such that:
• a recordable area of a first data storage layer has adjacent to an end thereof an extended area covering more than an area directly above a recordable area of a second data storage layer in a direction in which the first and second data storage layers are stacked, the first data storage layer being one of the data storage layers which is located closest to a light-striking surface of the medium, the second data storage layer being another of the data storage layers which is located next to the first data storage layer, opposite the light-striking surface;
• the extended area is a pseudo-recording area which is fully prerecorded;
• and the pseudo-recording area stores encryption information by which data is encrypted before being recorded on the optical storage medium;
• and
• the method comprises the step of encrypting data using the encryption information stored in the pseudo-recording area before recording the data in any of the data storage layers of the optical storage medium.

An optical read/write method using an optical storage medium including stacked data storage layers each of which is readable/writeable separately from the other layers by means of only a light beam striking one side of the optical storage medium, wherein:

• the optical storage medium is such that a recordable area of a first data storage layer has adjacent to an end thereof an extended area covering more than an area directly above a recordable area of a second data storage layer in a direction in which the first and second data storage layers are stacked, the first data storage layer being one of the data storage layers which is located closest to a light-striking surface of the medium, the second data storage layer being another of the data storage layers which is located next to the first data storage layer, opposite the light-striking surface;
• and
• the method comprises the steps of:
• preparing encryption information by which data is encrypted before being recorded on the optical storage medium;
• and recording the encryption information in the extended area.

An optical storage medium, comprising stacked data storage layers each of which is readable/writeable on both a land and a groove formed on the data storage layer separately from the other layers by means of only a light beam striking one side of the optical storage medium, each of the data storage layers having address tracks and at least one address area where there are collectively formed address information portions representing address information, the optical storage medium exhibiting an optical transmittance which varies when data is written by means of the light beam, wherein:

• in a first data storage layer, the address area has a first address area and a second address area which are adjacent to each other along tracks, the first data storage layer being one of the data storage layers which is located closest to a light-striking surface of the medium, a second data storage layer being another of the data storage layers which is located next to the first data storage layer, opposite the light-striking surface;
• the address information portions in either one of the first and second address areas are formed in those address tracks which extend from the land, and the address information portions in the other one of the first and second address areas are formed in those address tracks which extend from the groove;
• and
• either an area where the address information portions are formed or an area where no address information portions are formed is continuously recorded.

An optical read/write apparatus causing a read/write light beam from illuminating means to strike only one side of an optical storage medium including stacked data storage layers each of which is readable/writeable separately from the other layers by means of only a light beam striking one side of the optical storage medium, each of the data storage layers having address tracks and at least one address area where there are collectively formed address information portions representing address information, optical storage medium exhibiting an optical transmittance which varies when data is written by means of the light beam, wherein:

• the optical storage medium is such that each of the address tracks in the address area of a first data storage layer has a judgement mark to show whether the address track is to be continuously recorded or left unrecorded, the first data storage layer being one of the data storage layers which is located closest to a light-striking surface of the medium, a second data storage layer being another of the data storage layers which is located next to the first data storage layer, opposite the light-striking surface;
• and
• the optical read/write apparatus comprises controlling means for determining based on information reproduced from the judgement mark whether each of the address tracks in the address area is to be continuously recorded or left unrecorded and controlling the illuminating means according to a result of the determination so that each of the address tracks is to be either continuously recorded or left unrecorded.

An optical read/write apparatus causing a read/write light beam from illuminating means to strike only one side of an optical storage medium including stacked data storage layers each of which is readable/writeable on both a land and a groove formed on the data storage layer separately from the other layers by means of only a light beam striking one side of the optical storage medium, each of the data storage layers having address tracks and at least one address area where there are collectively formed address information portions representing address information, the optical storage medium exhibiting an optical transmittance which varies when data is written by means of the light beam,

• the optical read/write apparatus comprising controlling means for controlling the illuminating means so that:
• in a first data storage layer. the address area has a first address area and a second address area which are adjacent to each other along tracks, the first data storage layer being one of the data storage layers which is located closest to a light-striking surface of the medium, a second data storage layer being another of the data storage layers which is located next to the first data storage layer, opposite the light-striking surface;
• and when the address information portions in either one of the first and second address areas are formed in those address tracks which extend from the land, and the address information portions in the other one of the first and second address areas are formed in those address tracks which extend from the groove, either an area where the address information portions are formed or an area where no address information portions are formed is continuously recorded in the first and second address areas.

An optical read/write method, comprising the step of causing a read/write light beam from illuminating means to strike only one side of an optical storage medium including stacked data storage layers each of which is readable/writeable separately from the other layers by means of only a light beam striking one side of the optical storage medium, each of the data storage layers having address tracks and at least one address area where there are collectively formed address information portions representing address information, the optical storage medium exhibiting an optical transmittance which varies when data is written by means of the light beam, wherein:

• the optical storage medium is such that each of the address tracks in the address area of a first data storage layer has a judgement mark to show whether the address track is to be continuously recorded or left unrecorded, the first data storage layer being one of the data storage layers which is located closest to a light-striking surface of the medium, a second data storage layer being another of the data storage layers which is located next to the first data storage layer, opposite the light-striking surface;
• and
• the method further comprises the steps of determining based on information reproduced from the judgement mark whether each of the address tracks in the address area is to be continuously recorded or left unrecorded and causing each of the address tracks to be either continuously recorded or left unrecorded by means of the incident light according to a result of the determination.

An optical read/write method, comprising the step of causing a read/write light beam to strike only one side of an optical storage medium including stacked data storage layers each of which is readable/writeable on both a land and a groove formed on the data storage layer separately from the other layers by means of only a light beam striking one side of the optical storage medium, each of the data storage layers having address tracks and at last one address area where there are collectively formed address information portions representing address information, the optical storage medium exhibiting an optical transmittance which varies when data is written by means of the light beam, wherein:

• in a first data storage layer, the address area has a first address area and a second address area which are adjacent to each other along tracks, the first data storage layer being one of the data storage layers which is located closest to a light-striking surface of the medium, a second data storage layer being another of the data storage layers which is located next to the first data storage layer, opposite the light-striking surface;
• and
• the method further comprises the step of, when the address information portions in either one of the first and second address areas are formed in those address tracks which extend from the land, and the address information portions in the other one of the first and second address areas are formed in those address tracks which extend from the groove, continuously recording either an area where the address information portions are formed or an area where no address information portions are formed in the first and second address areas by means of the incident light.

An optical read/write apparatus causing a read/write light beam from illuminating means to strike only one side of an optical storage medium including:

• one light-striking-side storage layer provided as a data storage layer on a light-striking side;
• and one or more opposite-side storage layers as data storage layers provided opposite the light-striking side from the light-striking-side storage layer, wherein:
• the medium is such that one of the opposite-side storage layers which is, as a last data storage layer, most distanced from the light-striking-side storage layer has a prepit area which includes preformed pits representative of data:
• and
• the optical read/write apparatus comprises:
• envelope detecting means for detecting an envelope of a reproduction signal obtained from the prepit area;
• mean level producing means for producing a mean level of the detected envelope;
• and digital converting means for converting the reproduction signal to a digital signal using the mean level as a reference.

An optical read/write apparatus causing a read/write light beam from illuminating means to strike only one side of an optical storage medium including:

• one light-striking-side storage layer provided as a data storage layer on a light-striking side;
• and one or more opposite-side storage layers as data storage layers provided opposite the light-striking side from the light-striking-side storage layer, wherein:
• the medium is such that one of the opposite-side storage layers which is, as a last data storage layer, most distanced from the light-striking-side storage layer has a prepit area which includes preformed pits representative of data:
• and
• the optical read/write apparatus comprises:
• low frequency variation removing means for removing low frequency variations from the reproduction signal obtained from the prepit area;
• and digital converting means for converting the reproduction signal from which the low frequency variations are removed to a digital signal using a constant voltage as a reference.

An optical read/write apparatus causing a read/write light beam from illuminating means to strike only one side of an optical storage medium including:

• one light-striking-side storage layer provided as a data storage layer on a light-striking side;
• and one or more opposite-side storage layers as data storage layers provided opposite the light-striking side from the light-striking-side storage layer, wherein:
• the medium is such that one of the opposite-side storage layers which is, as a last data storage layer, most distanced from the light-striking-side storage layer has a prepit area which includes preformed pits representative of data and that each of the data storage layers except for the last data storage layer has a pseudo-recording area at such a position that allows light to be transmitted to the prepit area, the pseudo-recording area, when fully prerecorded, exhibiting a higher optical transmittance than other areas;
• and
• the optical read/write apparatus comprises:
• recording status checking means for checking whether the pseudo-recording area is fully recorded or not based on a reproduction signal obtained from the pseudo-recording area;
• and pseudo-recording means for fully recording data in the pseudo-recording area if the pseudo-recording area is not fully recorded.

An optical read/write method using an optical storage medium including:

• one light-striking-side storage layer provided as a data storage layer on a light-striking side;
• and one or more opposite-side storage layers as data storage layers provided opposite the light-striking side from the light-striking-side storage layer, the method comprising the step of causing a read/write light beam from illuminating means to strike only one side of the optical storage medium, wherein
• the medium is such that one of the opposite-side storage layers which is, as a last data storage layer, most distanced from the light-striking-side storage layer has a prepit area which includes preformed pits representative of data;
• and
• the method further comprises the steps of:
• producing a mean level of an envelope of a reproduction signal obtained from the prepit area;
• and converting the reproduction signal to a digital signal using the mean level as a reference.

An optical read/write method using an optical storage medium including:

• one light-striking-side storage layer provided as a data storage layer on a light-striking side;
• and one or more opposite-side storage layers as data storage layers provided opposite the light-striking side from the light-striking-side storage layer, the method comprising the step of causing a read/write light beam from illuminating means to strike only one side of the optical storage medium, wherein
• the medium is such that one of the opposite-side storage layers which is, as a last data storage layer, most distanced from the light-striking-side storage layer has a prepit area which includes preformed pits representative of data;
• and
• the method further comprises the steps of:
• removing low frequency variations from the reproduction signal obtained from the prepit area;
• and converting the reproduction signal from which the low frequency variations are removed to a digital signal using a constant voltage as a reference.

An optical read/write method, comprising the step of causing a read/write light beam from illuminating means to strike only one side of an optical storage medium including:

• one light-striking-side storage layer provided as a data storage layer on a light-striking side;
• and one or more opposite-side storage layers as data storage layers provided opposite the light-striking side from the light-striking-side storage layer, wherein
• the medium is such that one of the opposite-side storage layers which is, as a last data storage layer, most distanced from the light-striking-side storage layer has a prepit area which includes preformed pits representative of data and that each of the data storage layers except for the last data storage layer has a pseudo-recording area at such a position that allows light to be transmitted to the prepit area, the pseudo-recording area, when fully prerecorded, exhibiting a higher optical transmittance than other areas;
• the method further comprises the step of fully recording the pseudo-recording area so that light can transmit the prepit area.

An optical storage medium, comprising:

• one light-striking-side storage layer provided as a data storage layer on a light-striking side;
• and one or more opposite-side storage layers provided as data storage layers opposite the light-striking side from the light-striking-side storage layer, wherein:
• the light-striking-side storage layer has a prepit area which includes preformed pits representative of data;
• and
• the light-striking-side storage layer has a larger optically transparent, recordable area than do the opposite-side storage layers.

An optical storage medium, comprising:

• one light-striking-side storage layer provided as a data storage layer on a light-striking side;
• and one or more opposite-side storage layers provided as data storage layers opposite the light-striking side from the light-striking-side storage layer, wherein:
• the light-striking-side storage layer has a prepit area which includes preformed pits representative of data;
• and
• the prepit area allows transmission of light so that light reaches the opposite-side storage layers, at a transmittance substantially equal to that of a recordable area of the light-striking-side storage layer.

An optical read/write apparatus causing a read/write light beam from illuminating means to strike only one side of an optical storage medium including:

• one light-striking-side storage layer provided as a data storage layer on a light-striking side;
• and one or more opposite-side storage layers as data storage layers provided opposite the light-striking side from the light-striking-side storage layer, wherein:
• the optical storage medium is such that:
• the light-striking-side storage layer has a prepit area which includes preformed pits representative of date;
• the light-striking-side storage layer has a larger optically transparent, recordable area than do the opposite-side storage layers;
• and the recordable areas of the data storage layers except for a last data storage layer which is most distanced from the light-striking-side storage layer exhibit, when fully recorded, a higher optical transmittance than other areas;
• and
• the optical read/write apparatus comprises controlling means for controlling the illuminating means so that the recordable areas of the opposite-side storage layers located next to the light-striking-side storage layer are read/written after the recordable area of the light-striking-side storage layer is fully recorded.

An optical read/write apparatus causing a read/write light beam from illuminating means to strike only one side of an optical storage medium including:

• one light-striking-side storage layer provided as a data storage layer on a light-striking side;
• and one or more opposite-side storage layers as data storage layers provided opposite the light-striking side from the light-striking-side storage layer, wherein:
• the optical storage medium is such that:
• the light-striking-side storage layer has a prepit area which includes preformed pits representative of data;
• the prepit area allows transmission of light so that light reaches the opposite-side storage layers, at a transmittance substantially equal to that of a recordable area of the light-striking-side storage layer;
• and recordable areas of the data storage layers except for a last data storage layer which is most distanced from the light-striking-side storage layer exhibit, when fully recorded, a higher optical transmittance than other areas;
• and
• the optical read/write apparatus comprises controlling means for controlling the illuminating means so that the recordable areas of the opposite-side storage layers located next to the light-striking-side storage layer are read/written after the recordable area of the light-striking-side storage layer is fully recorded.

An optical read/write apparatus causing a read/write light beam from illuminating means to strike only one side of an optical storage medium including:

• one light-striking-side storage layer provided as a data storage layer on a light-striking side;
• and one or more opposite-side storage layers as data storage layers provided opposite the light-striking side from the light-striking-side storage layer, wherein:
• the optical storage medium is such that:
• the light-striking-side storage layer has a prepit area which includes preformed pits representative of data;
• the prepit area allows transmission of light so that light reaches the opposite-side storage layers, at a transmittance substantially equal to that of a recordable area of the light-striking-side storage layer;
• and the prepit area, under such illumination to fully record the prepit area substantially identically to the recordable area, exhibits a high optical transmittance substantially equal to that of the recordable area;
• the optical read/write apparatus comprises:
• continuous storage area checking means for checking based on a signal reproduced from the prepit area whether or not the prepit area has a continuous storage area where areas interposed between the pits are continuously and fully recorded as to a pit row of the pits;
• and continuous recording means for performing such recording that on the pit row in the prepit area where the continuous storage area is not present, there is formed the continuous storage area so that a fully recorded portion occupies a substantially equal area in a part where light is concentrated in the recordable area and in a part where light is concentrated in the prepit area.

An optical read/write method using an optical storage medium including:

• one light-striking-side storage layer provided as a data storage layer on a light-striking side;
• and one or more opposite-side storage layers as data storage layers provided opposite the light-striking side from the light-striking-side storage layer, the method comprising the step of causing a read/write light beam from illuminating means to strike only one side of the optical storage medium, wherein:
• the optical storage medium is such that the light-striking-side storage layer has a prepit area which includes preformed pits representative of data;
• and the prepit area allows transmission of light so that light reaches the opposite-side storage layers, at a transmittance substantially equal to that of a recordable area of the light-striking-side storage layer;
• and
• the optical read/write method comprises the step of reading/writing the recordable areas of the opposite-side storage layers located next to the light-striking-side storage layer after fully recording the recordable area of the light-striking-side storage layer.

An optical read/write method using an optical storage medium including:

• one light-striking-side storage layer provided as a data storage layer on a light-striking side;
• and one or more opposite-side storage layers as data storage layers provided opposite the light-striking side from the light-striking-side storage layer, the method comprising the step of causing a read/write light beam from illuminating means to strike only one side of the optical storage medium, wherein:
• the optical storage medium is such that:
• the light-striking-side storage layer has a prepit area which includes preformed pits representative of data;
• the prepit area allows transmission of light so that light reaches the opposite-side storage layers, at a transmittance substantially equal to that of a recordable area of the light-striking-side storage layer;
• and the prepit area, under such illumination to fully record the prepit area substantially identically to the recordable area, exhibits a high optical transmittance substantially equal to that of the recordable area;
• the method comprises the step of performing such recording that as to a pit row of the pits to form a continuous storage area on the pit row in the prepit area in the continuous storage area where areas interposed between the pits are continuously and fully recorded is not present so that a fully recorded portion occupies a substantially equal area in a part where light is concentrated in the recordable area and in a part where light is concentrated in the prepit area.