Write-once information recording medium, information recording method, information recording apparatus, information reproducing method, information reproducing apparatus and manufacturing method of the information recording medium

A method for writing information on a write-once information recording medium on which a read/write operation is performed on a block-by-block basis,

• wherein the information recording medium has 1st through nth recording layers (where n is an integer that satisfies n≦1), and
• wherein the 1st through nth recording layers have 1st through nth user data areas to write user data on, and
• wherein at least one of the 1st through nth recording layers has a disc management area to store disc management information about the information recording medium, and
• wherein the disc management information includes
• a disc definition structure for use to manage the data structure of the information recording medium, and
• 1st through nth space bitmaps for use to manage the recording statuses of the 1st through nth user data areas, and
• wherein each of the 1st through nth space bitmaps includes bitmap information for use to manage the recording status of its associated one of the 1st through nth user data areas on a block-by-block basis, and
• wherein if in a situation where the largest space is allocated to an ith user data area (where i is an integer that falls within the range 1≦i≦n), the number of blocks to use to store the ith space bitmap is Ni (where Ni is an integer that satisfies Ni≧2), and if the number of blocks to use to store the ith space bitmap for the ith user data area of an actual size is Mi (where Mi is an integer that satisfies 1≦Mi≦Ni) and if Mi is equal to or greater than two,
• then the information writing method comprises the step of dividing the ith space bitmap into the 1st through Mith space bitmaps, each of which has a size that is still equal to or smaller than one block even when combined with the disc definition structure, and storing each said space bitmap in an associated one of the Mi blocks in the disc management area.

A method for reading information from a write-once information recording medium on which a read/write operation is performed on a block-by-block basis,

• wherein the information recording medium has 1st through nth recording layers (where n is an integer that satisfies n≧1), and
• wherein the 1st through nth recording layers have 1st through nth user data areas to write user data on, and
• wherein at least one of the 1st through nth recording layers has a disc management area to store disc management information about the information recording medium, and
• wherein the disc management information includes
• a disc definition structure for use to manage the data structure of the information recording medium, and
• 1st through nth space bitmaps for use to manage the recording statuses of the 1st through nth user data areas, and
• wherein each of the 1st through nth space bitmaps includes bitmap information for use to manage the recording status of its associated one of the 1st through nth user data areas on a block-by-block basis, and
• wherein if in a situation where the largest space is allocated to an ith user data area (where i is an integer that falls within the range 1≦i≦n), the number of blocks to use to store the ith space bitmap is Ni (where Ni is an integer that satisfies Ni≧2), and if the number of blocks to use to store the ith space bitmap for the ith user data area of an actual size is Mi (where Mi is an integer that satisfies 1≦Mi≦Ni) and if Mi is equal to or greater than two,
• then the ith space bitmap is divided into the 1st through Mith space bitmaps, each of which has a size that is still equal to or smaller than one block even when combined with the disc definition structure, and each said space bitmap is stored in an associated one of the Mi blocks in the disc management area, and
• wherein the information reading method comprises the step of retrieving the ith space bitmap from the Mi blocks.

An apparatus for writing information on a write-once information recording medium on which a read/write operation is performed on a block-by-block basis,

• wherein the information recording medium has 1st through nth recording layers (where n is an integer that satisfies n≧1), and
• wherein the 1st through nth recording layers have 1st through nth user data areas to write user data on, and
• wherein at least one of the 1st through nth recording layers has a disc management area to store disc management information about the information recording medium, and
• wherein the disc management information includes
• a disc definition structure for use to manage the data structure of the information recording medium, and
• 1st through nth space bitmaps for use to manage the recording statuses of the 1st through nth user data areas, and
• wherein each of the 1st through nth space bitmaps includes bitmap information for use to manage the recording status of its associated one of the 1st through nth user data areas on a block-by-block basis, and
• wherein if in a situation where the largest space is allocated to an ith user data area (where i is an integer that falls within the range 1≦i≦n), the number of blocks to use to store the ith space bitmap is Ni (where Ni is an integer that satisfies Ni≦2), and if the number of blocks to use to store the ith space bitmap for the ith user data area of an actual size is Mi (where Mi is an integer that satisfies 1≦Mi≦Ni) and if Mi is equal to or greater than two,
• then the information writing apparatus divides the ith space bitmap into the 1st through Mith space bitmaps, each of which has a size that is still equal to or smaller than one block even when combined with the disc definition structure, and stores each said space bitmap in an associated one of the Mi blocks in the disc management area.

An apparatus for reading information from a write-once information recording medium on which a read/write operation is performed on a block-by-block basis,

• wherein the information recording medium has 1st through nth recording layers (where n is an integer that satisfies n≧1), and
• wherein the 1st through nth recording layers have 1st through nth user data areas to write user data on, and
• wherein at least one of the 1st through nth recording layers has a disc management area to store disc management information about the information recording medium, and
• wherein the disc management information includes
• a disc definition structure for use to manage the data structure of the information recording medium, and
• 1st through nth space bitmaps for use to manage the recording statuses of the 1st through nth user data areas, and
• wherein each of the 1st through nth space bitmaps includes bitmap information for use to manage the recording status of its associated one of the 1st through nth user data areas on a block-by-block basis, and
• wherein if in a situation where the largest space is allocated to an ith user data area (where i is an integer that falls within the range 1≦i≦n), the number of blocks to use to store the ith space bitmap is Ni (where Ni is an integer that satisfies Ni≧2), and if the number of blocks to use to store the ith space bitmap for the ith user data area of an actual size is Mi (where Mi is an integer that satisfies 1≦Mi≦Ni) and if Mi is equal to or greater than two,
• then the ith space bitmap is divided into the 1st through Mith space bitmaps, each of which has a size that is still equal to or smaller than one block even when combined with the disc definition structure, and each said space bitmap is stored in an associated one of the Mi blocks in the disc management area, and
• wherein the information reading apparatus retrieves the ith space bitmap from the Mi blocks.

A method of making a write-once information recording medium on which a read/write operation is performed on a block-by-block basis,

• wherein the method comprises the steps of:
• forming 1st through nth recording layers (where n is an integer that satisfies n≧1);
• defining 1st through nth user data areas to write user data on in the 1st through nth recording layers;
• and
• defining a disc management area to store disc management information about the information recording medium on at least one of the 1st through nth recording layers, and
• wherein the disc management information includes
• a disc definition structure for use to manage the data structure of the information recording medium, and
• 1st through nth space bitmaps for use to manage the recording statuses of the 1st through nth user data areas, and
• wherein each of the 1st through nth space bitmaps includes bitmap information for use to manage the recording status of its associated one of the 1st through nth user data areas on a block-by-block basis, and
• wherein if in a situation where the largest space is allocated to an ith user data area (where i is an integer that falls within the range 1≦i≦n), the number of blocks to use to store the ith space bitmap is Ni (where Ni is an integer that satisfies Ni≧2), and if the number of blocks to use to store the ith space bitmap for the ith user data area of an actual size is Mi (where Mi is an integer that satisfies 1≦Mi≦Ni), and if Mi is equal to or greater than two,
• then the ith space bitmap is divided into the 1st through Mith space bitmaps, each of which has a size that is still equal to or smaller than one block even when combined with the disc definition structure, and each said space bitmap is stored in an associated one of the Mi blocks in the disc management area.