Write-once information recording medium, information recording apparatus, information recording method, information reproducing apparatus and information reproducing method

An information writing apparatus for writing information on a write-once information recording medium, which has at least one recording layer and on which information is written on a block-by-block basis,

• wherein the write-once information recording medium comprises:
• a user data area on which user data is going to be written;
• and
• a management information area to store management information about the write-once information recording medium, and
• wherein the user data area is provided for each said recording layer, and
• wherein the management information comprises:
• a space bitmap including bitmap information for use to manage recording statuses in the user data area on a predetermined one recording layer of the at least one recording layer;
• and
• a disc definition structure including location information of the space bitmap, and
• wherein the size of the space bitmap is determined so that the combined size of the space bitmap itself and the disc definition structure always becomes equal to that of one block, irrespective of the size of the user data area, and
• wherein the information writing apparatus comprising:
• a writing section for writing information on the write-once information recording medium, and
• a control section for controlling the writing section, and
• wherein if the size of the user data area on the predetermined one recording layer exceeds a predetermined size where the predetermined size is a maximum size of the user data area that can be managed by one piece of bitmap information, the control section generate multiple space bitmaps for the user data area of the predetermined one recording layer, and the control section controls the writing section so as to write a disc management structure update unit, including one of the multiple space bitmaps and the disc definition structure and having a size of one block, on the management information area.

An information writing method for writing information on a write-once information recording medium, which has at least one recording layer and on which information is written on a block-by-block basis,

• wherein the write-once information recording medium comprises:
• a user data area on which user data is going to be written;
• and
• a management information area to store management information about the write-once information recording medium, and
• wherein the user data area is provided for each said recording layer, and
• wherein the management information comprises:
• a space bitmap including bitmap information for use to manage recording statuses in the user data area on a predetermined one recording layer of the at least one recording layers;
• and
• a disc definition structure including location information of the space bitmap, and
• wherein the size of the space bitmap is determined so that the combined size of the space bitmap itself and the disc definition structure always becomes equal to that of one block, irrespective of the size of the user data area, and
• wherein the information writing method comprises the steps of:
• determining whether a size of the user data area on the predetermined one recording layer exceeds a predetermined size where the predetermined size is a maximum size of the user data area that can be managed by one piece of bitmap information,
• if the size of the user data area on the predetermined recording layer exceeds the predetermined size,
• generating multiple space bitmaps for the user data area of the predetermined one recording layer, and
• writing a disc management structure update unit, including one of the multiple space bitmaps and the disc definition structure and having a size of one block, on the management information area.

An information reading apparatus for reading information from a write-once information recording medium, which has at least one recording layer and on which information is written on a block-by-block basis,

• wherein the write-once information recording medium comprises:
• a user data area on which user data is going to be written;
• and
• a management information area to store management information about the write-once information recording medium, and
• wherein the user data area is provided for each said recording layer, and
• wherein the management information comprises:
• a space bitmap including bitmap information for use to manage recording statuses in the user data area on a predetermined one recording layer of the at least one recording layer;
• and
• a disc definition structure including location information of the space bitmap, and
• wherein the size of the space bitmap is determined so that the combined size of the space bitmap itself and the disc definition structure always becomes equal to that of one block, irrespective of the size of the user data area, and
• wherein the size of the user data area on the predetermined one recording layer exceeds a predetermined size,
• the predetermined size is a maximum size of the user data area that can be managed by one piece of bitmap information,
• multiple space bitmaps are generated for the user data area of the predetermined one recording layer, and
• a disc management structure update unit, including one of the multiple space bitmaps and the disc definition structure and having a size of one block, is written on the management information area, and
• wherein the information reading apparatus comprising:
• a reading section for reading information from the write-once information recording medium, and
• a control section for controlling the reading section, and
• wherein the control section controls the reading section as to read the disc management structure update unit, including the disc definition structure and having a size of one block, from the management information area and obtains the space bitmap.

An information reading method for reading information from a write-once information recording medium, which has at least one recording layer and on which information is written on a block-by-block basis,

• wherein the write-once information recording medium comprises:
• a user data area on which user data is going to be written;
• and
• a management information area to store management information about the write-once information recording medium, and
• wherein the user data area is provided for each said recording layer, and
• wherein the management information comprises:
• a space bitmap including bitmap information for use to manage recording statuses in the user data area on a predetermined one recording layer of the at least one recording layer;
• and
• a disc definition structure including location information of the space bitmap, and
• wherein the size of the space bitmap is determined so that the combined size of the space bitmap itself and the disc definition structure always becomes equal to that of one block, irrespective of the size of the user data area, and
• wherein the size of the user data area on the predetermined one recording layer exceeds a predetermined size,
• the predetermined size is a maximum size of the user data area that can be managed by one piece of bitmap information,
• multiple space bitmaps are generated for the user data area of the predetermined one recording layer, and
• a disc management structure update unit, including one of the multiple space bitmaps and the disc definition structure and having a size of one block, is written on the management information area, and
• wherein the information reading method includes the step of reading the disc management structure update unit, including the disc definition structure and having a size of one block, from the management information area and obtains the space bitmap.