Phase change optical information recording medium, information recording method and apparatus therefor, and information erasing method therefor

Abstract

A phase change optical information recording medium including: a substrate; and a recording layer which is located overlying the substrate and in which marks are to be formed to store information, wherein the substrate includes plural sessions including a first session in which pits are formed and which includes a RAM region including a groove and a wobble signal, and a program memory area in which pits are formed and which includes position information of the first session and does not include disc ID information of the phase change optical information recording medium.

1 - 7 . (canceled)  
     
     
         8 . An information recording apparatus comprising: 
 receiving means for receiving an order to record or erase information in a phase change optical information recording medium;    reading means for reading a position of disc ID information stored in a program memory area of the phase change optical information recording medium and position information of plural sessions of the phase change optical information recording medium;    recording/erasing means for recording and erasing information in the plural sessions; and    controlling means for controlling the recording/erasing means to record or erase the information in one or more of the plural sessions according to the order when the position information of the one or more sessions is located after the disc ID information in the program memory area, or refusing the order when the position information of the one or more of the plural sessions located before the disc ID information in the program memory area.    
     
     
         9 . The information recording apparatus according to  claim 8 , wherein the controlling means further has a function of ordering the recording/erasing means to rewrite the disc ID information such that the position of the ID information is changed to record and erase the information in the one or more of the plural sessions.  
     
     
         10 . The information recording apparatus according to  claim 8 , further comprising a memory storing session information concerning recordable and erasable sessions, wherein the controlling means further has a function of referring to the session information stored in the memory when the receiving means receives an erasure order for a last session of the plural sessions in the optical information recording medium to determine whether or not the last session is an erasable session, and ordering the recording/erasing means to erase the last session when the last session is a recordable and erasable session or refusing the erasure order when the last session is not a recordable and erasable session.  
     
     
         11 . The information recording apparatus according to  claim 8 , further comprising a memory storing session information concerning non-recordable and non-erasable sessions, wherein the controlling means further has a function of referring to the session information stored in the memory when the receiving means receives a complete erasure order for the plural sessions in the phase change optical information recording medium to determine whether or not a non-recordable and non-erasable session is present in the memory, and ordering the recording/erasing means to perform the complete erasure order when a non-recordable and non-erasable session is not present in the memory or refusing the complete erasure order when a non-recordable and non-erasable session is present in the memory.  
     
     
         12 . An information recording apparatus which records information in a phase change optical information recording medium including plural sessions each including at least one of a ROM region not including a wobble signal and a RAM region including a wobble signal, comprising: 
 receiving means for receiving an erasure order for a session;    judging means for checking whether a wobble signal is present in the session to determine whether the session does not include a ROM region; and    erasing means for erasing the session when the session does not include the ROM region.    
     
     
         13 . A method for recording and erasing information in a phase change optical information recording medium including a program memory area and plural sessions, comprising: 
 reading position information of disc ID information on the program memory area and position information of the plural sessions of the phase change optical information recording medium; and    recording and erasing information in one or more of the plural sessions upon receiving of an order to record or erase the information when the position information of the one or more of the plural sessions is located after the disc ID information, or refusing the order to record and erase the information when the position information of the one or more of the plural sessions is located before the disc ID information.    
     
     
         14 . The method according to  claim 13 , further comprising: 
 rewriting the disc ID information such that the position of the ID information is changed to control recording and erasing of information in the one or more of the plural sessions.    
     
     
         15 . A method of recording information in a phase change optical information recording medium including plural sessions each including at least one of a ROM region not including a wobble signal and a RAM region including a wobble signal, comprising: 
 checking whether a wobble signal is present in a session to determine whether the session does not include a ROM region upon receiving an erasure order for the session; and    erasing the session when the session does not include a ROM region.    
     
     
         16 . A method for determining an optimum CW erasure power for erasing information in a phase change information recording medium, comprising: 
 CW-erasing HF signals, which are recorded in the phase change information recording medium with a fixed writing power while changing an erasure power Pe;    measuring a pit level I 11 L or both the pit level I 11 L and a land level I 11 H of a remaining  11 t signal of the HF signals;    determining the optimum CW erasure power Pecw such that at least one of the following relationships (1) and (2) is satisfied:       Pe   1 +0.05×Δ Pecw≦Pe   2 −0.05×Δ Pe   (1)   wherein Pe 1  represents a Pe when d(I 11 L)/d(Pe) is maximized, Pe 2  represents a Pe when d(I 11 L)/d(Pe) is minimized, and Δ Pe represents Pe 2 −Pe 1 ; and       I   11   L/I   11   H> 0.8  (2).   
     
     
         17 . The method according to  claim 16 , wherein the fixed writing power is higher than an optimum writing power (Pwo) determined by a γ method.  
     
     
         18 . The method according to  claim 16 , wherein the CW-erasing step is performed at a linear speed of the phase change optical information recording medium that is higher than a maximum recording linear speed of the phase change optical information recording medium.  
     
     
         19 . A method of directly overwriting information in a phase change optical information recording medium, comprising: 
 recording information in the phase change optical information recording medium while erasing information stored in the phase change optical information recording medium with an erasure power,    wherein the erasure power is the optimum CW erasure power determined by the method according to  claim 16 .    
     
     
         20 . A method of directly overwriting information in a phase change optical information recording medium, comprising: 
 first recording information in the phase change optical information recording medium by applying a writing power and an erasure power thereto to record HF signals therein while the writing power is changed and the erasure power is fixed;    measuring a mark-length/pit-length balance β of the HF signals;    determining an optimum writing power such that the mark-length/pit-length balance β is from 0 to 8%; and    second recording information in the phase change optical information recording medium while applying the optimum writing power to the phase change optical information recording medium.    
     
     
         21 . An information erasing method comprising: 
 performing CW erasing on a phase change optical information recording medium having a ROM region formed by a stamper, by applying an erasure power thereto,    wherein the erasure power is determined by the CW erasure power determination method according to  claim 16.