Optical information recording medium, optical information recording method, and optical information recording apparatus

Abstract

An information recording medium according to the present invention includes a plurality of recording layers, and a test area for determining a recording power of a laser light for each of the plurality of recording layers, in which a first test area of a first layer and a second test area of a second layer adjacent to the first layer are provided at different radial positions.

1 . An optical information recording medium, comprising:
 a first information recording layer on which information is to be recorded by laser light; and   a second information recording layer on which information is to be recorded by the laser light which has passed through the first information recording layer,   wherein:   the first information recording layer includes a prescribed area,   the second information recording layer includes a test recording area,   the prescribed area and the test recording area are located such that the prescribed area includes an area of the first information recording layer through which the laser light for recording information in the test recording area passes, and   the prescribed area is entirely in a recorded state or entirely in an unrecorded state.   
     
     
         2 . An optical information recording medium according to  claim 1 , wherein the prescribed area, when being in an unrecorded state, is a recording prohibited area. 
     
     
         3 . An optical information recording medium according to  claim 1 , wherein the prescribed area, when being in an unrecorded state, is a mirror area. 
     
     
         4 . An optical information recording medium according to  claim 1 , wherein the prescribed area, when being in an unrecorded state, is a lead-in area. 
     
     
         5 . An optical information recording medium according to  claim 1 , further comprising a separation layer for separating the first information recording layer and the second information recording layer from each other, wherein:
 the area of the first information recording layer, through which the laser light for recording information in the test recording area passes, extends outward from an outer end of an area of the first information recording layer corresponding to the test recording area by a length δ, the length δ being represented by:
   δ= d ·tan(sin −1 ( NA/n )), 
   
       where d is a distance in a thickness direction between the first information recording layer and the second information recording layer; n is a refractive index of the separation layer; and NA is a numerical aperture of an objective lens for focusing the laser light to the test recording area. 
     
     
         6 . An optical information recording medium according to  claim 5 , wherein the second information recording layer has a data recording area which extends from an end of the test recording area by at least the length δ. 
     
     
         7 . An optical information recording medium according to  claim 5 , wherein the area of the first information recording layer, through which the laser light for recording information in the test recording area passes, extends outward from the outer end of the area of the first information recording layer corresponding to the test recording area by a length δ′, the length δ′ being represented by:
   δ′= d ·tan(sin −1 ( NA/n ))+δ m      where δm is a maximum positional offset distance between the first information recording layer and the second information recording layer.   
     
     
         8 . An optical information recording medium according to  claim 7 , wherein the second information recording layer includes a data recording area which extends from the end of the test recording area by at least the length δ′. 
     
     
         9 . An optical information recording medium, comprising:
 a first information recording layer on which information is to be recorded by laser light; and   a second information recording layer on which information is to be recorded by the laser light which has passed through the first information recording layer,   wherein:   the first information recording layer includes a test recording area and a recording and reproduction area,   a light transmittance of an area of the first information recording layer, through which the laser light for recording information in the test recording area passes, is different from a light transmittance of an area of the first information recording layer, through which the laser light for recording information in the recording and reproduction area passes, and   information for calculating an optimum recording condition of at least one of the test recording area and the recording and reproduction area is recorded in a specific area of either the first information recording layer or the second information recording layer.   
     
     
         10 . An optical information recording medium, comprising:
 a first information recording layer on which information is to be recorded by laser light; and   a second information recording layer on which information is to be recorded by the laser light which has passed through the first information recording layer,   wherein:   the first information recording layer includes at least one of a reproduction-only area and a first recording and reproduction area,   the second information recording layer includes a second recording and reproduction area, and   at least one of the reproduction-only area and the first recording and reproduction area, and the second recording and reproduction area are located such that one of the reproduction-only area and the first recording and reproduction area includes an area of the first information recording layer through which the laser light for recording information in the second recording and reproduction area passes.   
     
     
         11 . An optical information recording medium according to  claim 10 , further comprising a separation layer for separating the first information recording layer and the second information recording layer from each other, wherein:
 the area of the first information recording layer, through which the laser light for recording information in the second recording and reproduction area passes, extends outward from an outer end of an area of the first information recording layer corresponding to the second recording and reproduction area by a length δ, the length δ being represented by:
   δ= d ·tan(sin −1 ( NA/n )), 
   
       where d is a distance in a thickness direction between the first information recording layer and the second information recording layer; n is a refractive index of the separation layer; and NA is a numerical aperture of an objective lens for focusing the laser light to the second recording and reproduction area. 
     
     
         12 . An optical information recording medium according to  claim 11 , wherein the area of the first information recording layer, through which the laser light for recording information in the second recording and reproduction area passes, extends outward from the outer end of the area of the first information recording layer corresponding to the second recording and reproduction area by a length δ′, the length δ′ being represented by:
   δ′= d ·tan(sin −1 ( NA/n ))+δ m      where δm is a maximum positional offset distance between the first information recording layer and the second information recording layer.   
     
     
         13 . An optical information recording medium according to  claim 10 , wherein a size of the reproduction-only area of the first information recording layer is zero. 
     
     
         14 . An optical information recording medium, comprising:
 a first information recording layer on which information is to be recorded by laser light;   a second information recording layer on which information is to be recorded by the laser light which has passed through the first information recording layer; and   a separation layer for separating the first information recording layer and the second information recording layer from each other,   wherein:   the first information recording layer includes at a first test recording area and a non-uniform light prevention area,   the second information recording layer includes a second test recording area, and   the non-uniform light prevention area, the first test recording area and the second test recording area are located, such that a distance between the first test recording area and the second test recording area is greater than a length δ, and such that the non-uniform light prevention area includes an area of the first information recording layer through which the laser light for recording information in the second test recording area passes, the length δ being represented by:
   δ= d ·tan(sin −1 ( NA/n )), 
   
       where d is a distance in a thickness direction between the first information recording layer and the second information recording layer; n is a refractive index of the separation layer; and NA is a numerical aperture of an objective lens for focusing the laser light to the second test recording area. 
     
     
         15 . An optical information recording medium according to  claim 14 , wherein:
 the first information recording layer includes at least one of a first lead-in area and a first lead-out area,   the second information recording layer includes at least one of a second lead-in area and a second lead-out area, and   the first lead-in area and the second lead-in area respectively include the first test recording area and the second test recording area, or the first lead-out area and the second lead-out area respectively include the first test recording area and the second test recording area.   
     
     
         16 . An optical information recording medium according to  claim 14 , wherein the non-uniform light prevention area of the first information recording layer is a reproduction-only area. 
     
     
         17 . An optical information recording medium according to  claim 14 , wherein the non-uniform light prevention area is an area formed of at least one of the group consisting of a reproduction-only area, a recording prohibited area, and a mirror area. 
     
     
         18 . An optical information recording medium according to  claim 14 , wherein the area of the first information recording layer, through which the laser light for recording information in the second test recording area passes, extends outward from an outer end of an area of the first information recording layer corresponding to the second test recording area by a length δ′, the length δ′ being represented by:
   δ′= d ·tan(sin −1 ( NA/n ))+δ m      where δm is a maximum positional offset distance between the first information recording layer and the second information recording layer.   
     
     
         19 . An optical information recording medium according to  claim 17 , wherein the area of the first information recording layer, through which the laser light for recording information in the second test recording area passes, extends outward from an outer end of an area of the first information recording layer corresponding to the second test recording area by a length δ′, the length δ′ being represented by:
   δ′= d ·tan(sin −1 ( NA/n ))+δ m      where δm is a maximum positional offset distance between the first information recording layer and the second information recording layer.   
     
     
         20 . An optical information recording method for an optical information recording medium including a first information recording layer on which information is to be recorded by laser light; and a second information recording layer on which information is to be recorded by the laser light which has passed through the first information recording layer,
 wherein:   the first information recording layer includes at least one of a reproduction-only area and a recording and reproduction area, and   the second information recording layer includes a test recording area,   the optical information recording method comprising the steps of:   recording information, in advance, in an area of the first information recording layer, through which the laser light for recording information in the test recording area is to pass; and   recording the information in the test recording area after the step of recording the information in advance.   
     
     
         21 . An optical information recording method according to  claim 20 , further comprising a separation layer for separating the first information recording layer and the second information recording layer from each other, wherein:
 the area of the first information recording layer, through which the laser light for recording information in the test recording area passes, extends outward from an outer end of an area of the first information recording layer corresponding to the test recording area by a length δ, the length δ being represented by:
   δ= d ·tan(sin −1 ( NA/n )), 
   
       where d is a distance in a thickness direction between the first information recording layer and the second information recording layer; n is a refractive index of the separation layer; and NA is a numerical aperture of an objective lens for focusing the laser light to the test recording area. 
     
     
         22 . An optical information recording method according to  claim 21 , wherein the area of the first information recording layer, through which the laser light for recording information in the test recording area passes, extends outward from the outer end of the area of the first information recording layer corresponding to the test recording area by a length δ′, the length δ′ being represented by:
   δ′= d ·tan(sin −1 ( NA/n ))+δ m      where δm is a maximum positional offset distance between the first information recording layer and the second information recording layer.   
     
     
         23 . An optical information recording method according to  claim 20 , wherein the information which is recorded in advance is information obtained by modulating dummy information. 
     
     
         24 . An optical information recording method according to  claim 20 , wherein the step of recording the information in advance includes the step of recording using a certification step. 
     
     
         25 . An optical information recording method for an optical information recording medium including a first information recording layer on which information is to be recorded by laser light; and a second information recording layer on which information is to be recorded by the laser light which has passed through the first information recording layer,
 wherein:   the first information recording layer includes at least one of a reproduction-only area and a recording and reproduction area, and   the second information recording layer includes a test recording area,   the optical information recording method comprising the steps of:   determining whether an area of the first information recording layer, through which the laser light for recording information in the test recording area passes, is an area of one of the reproduction-only area and the recording and reproduction area which is an unrecorded state or an area of the recording and reproduction area which is in a recorded state;   executing test recording in the test recording area so as to obtain a recording condition; and   calculating an optimum recording condition for the second information recording layer based on the result of the determination and the obtained recording condition.   
     
     
         26 . An optical information recording method according to  claim 25 , wherein:
 the optical information recording medium further includes a separation layer for separating the first information recording layer and the second information recording layer from each other, and   the area of the first information recording layer, through which the laser light for recording information in the test recording area passes, extends outward from an outer end of an area of the first information recording layer corresponding to the test recording area by a length δ, the length δ being represented by:
   δ= d ·tan(sin −1 ( NA/n )), 
   
       where d is a distance in a thickness direction between the first information recording layer and the second information recording layer; n is a refractive index of the separation layer; and NA is a numerical aperture of an objective lens for focusing the laser light to the second recording and reproduction area. 
     
     
         27 . An optical information recording method according to  claim 26 , wherein the area of the first information recording layer, through which the laser light for recording information in the test recording area passes, extends outward from the outer end of the area of the first information recording layer corresponding to the test recording area by a length δ′, the length δ′ being represented by:
   δ′= d ·tan(sin −1 ( NA/n ))+δ m      where δm is a maximum positional offset distance between the first information recording layer and the second information recording layer.   
     
     
         28 . An optical information recording method according to  claim 25 , wherein the information for calculating the optimum recording condition is recorded in a specific area of the first information recording layer and the second information recording layer. 
     
     
         29 . An optical information recording apparatus for an optical information recording medium including a first information recording layer on which information is to be recorded by laser light; and a second information recording layer on which information is to be recorded by the laser light which has passed through the first information recording layer,
 wherein the second information recording layer includes a test recording area,   the optical information recording apparatus comprising:   an interference area determination section for determining an area of the first information recording layer through which the laser light for recording information in the test recording area passes;   a recorded/unrecorded state determination section for determining whether the area of the first information recording layer, through which the laser light for recording information in the test recording area passes, is in a recorded state or in an unrecorded state; and   a recording section for recording a signal in the area of the first information recording layer, through which the laser light for recording information in the test recording area passes, based on the results of the determination of the interference area determination section and the recorded/unrecorded state determination section.