Additionally recordable information recording medium, information recording method, information reproducing method, information recording apparatus and information reproducing apparatus

An information recording apparatus for recording data on an additionally recordable information recording medium having a plurality of recording layers,

• each of the plurality of recording layers including a user data area for recording a user data,
• a predetermined recording layer, which is one of the plurality of recording layers, having a recorded-area-location storage area for storing a last recorded address indicating an address of a recorded area located at the rearmost location in the user data area, and
• at least one recording layer other than the predetermined recording layer, having a recorded-area-location storage backup area for compensating for a shortage in the recorded-area-location storage area,
• wherein each of the recorded-area-location storage area and the recorded-area-location storage backup area is located at an inner circumference area of the user area,
• the information recording apparatus comprising:
• a determining means for determining whether it is necessary to update the last recorded address or not;
• and
• an updating means for updating the last recorded address to an address of a rearmost area in the user data area, in which the user data is recorded, wherein
• in the event at least one unrecorded area is located in a forward direction from the last recorded address,
• the determining means determines that it is not necessary to update the last recorded address if the user data is recorded in the at least one unrecorded area, and determines that it is necessary to update the last recorded address if the user data is recorded in an area rearwardly away from the last recorded address, and
• the updating means records the last recorded address in the recorded-area-location storage backup area when a shortage of an area for storing the last recorded address occurs in the recorded-area-location storage area.