BS ISO IEC 30191:2015 pdf free download – Information technology – Digitally recorded media forinformation interchange and storage – 120 mm TripleLayer (100,0 Gbytes single side disk and 200,0 Gbytesdouble sided disk) and Quadruple Layer (128,0 Gbytessingle sided disk) BD Recordable disk
7 General description of disk
This International Standard provides for three Types of disks.
Type TL disk: The 120 mm optical disk consists of a Substrate of about 1,1 mm nominal thickness. TheSubstrate is covered with three Recording Layers. The Recording Layers consist of several layers. The threeRecording Layers are separated by two transparent Spacer Layers whose thicknesses are about 25,0 um and18,0 um, respectively in this order from the Substrate. On top of these Recording Layers, a transparent CoverLayer of about 57,0 um is applied with accurately defined optical characteristics(see Figure 1).
Type QL disk: The 120 mm optical disk consists of a Substrate of about 1,1 mm nominal thickness. TheSubstrate is covered with four Recording Layers. The four Recording Layers are separated by threetransparent Spacer Layers whose thickness are about 15,5 um, 19,5 um and 11,5 um, respectively in thisorder from the Substrate, and on top of these Recording Layers, a transparent Cover Layer of about 53,5 umis applied (see Figure 2).
Type TL/D disk: The 120 mm optical disk consists of a Substrate of about 1,0 mm nominal thickness. TheSubstrate is covered with three Recording Layers on each side. The Recording Layers of each side have thesame characteristics and structure as a Type TL disk (see Figure 0.1). The three Recording Layers on eachside of a disk can be accessed from the side only.Requirements specific for a Type TLD disk are defined inAnnex O. All requirements for a Type TL disk shall be applied to a Type TL/D disk unless othenwise describedincluding Annex o.
The first (Layer L2) and second (Layer L1)Recording Layers of a Type TL disk and a Type TL/D disk and thefirst (Layer L3), second (Layer L2) and third (Layer L1) Recording Layers of a Type QL disk seen from theread-out side of the disks shall be semi-transparent.
The optical beam shall be compensated for Spherical Aberrations (SA) such that these aberrations areminimized for the thickness of the Transmission Stack of the Recording Layer on which the beam is focusedat the radius where the measurement is to be performed.
During measurements on one layer of a Mult-Layer disk, light reflected from the other layers can influence themeasurements on the layer under investigation. To cope with these effects，the photodetector shall havedefined dimensions. lts length and width shall be smaller than M × 5 um, where M is the transversal opticalmagnification from the disk to its conjugate plane near the quadrant photodetector.For a TL disk or a QL disk,however, the effect cannot be neglected even if length and width of the photodetector is smaller than M × 5um. Therefore observed reflectivity shall be compensated using the procedure shown in B.4.
10.1 General
Dimensional characteristics are specified for those parameters deemed mandatory for interchange andcompatible use of the disk. Where there is freedom of design，only the functional characteristics of theelements described are indicated.The enclosed drawing, Figure 11 shows the dimensional requirements insummarized form.The different parts of the disk are described from the centre hole to the outside Rim.