BS ISO IEC 30191-2015 pdf free download – Information technology — Digitally recorded media for information interchange and storage — 120 mm Triple Layer (100,0 Gbytes single side disk and 200,0 Gbytes double sided disk) and Quadruple Layer (128,0 Gbytes single 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 O.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 aType TL/D disk unless otherwise describedincluding Annex o.
The first (Layer L2) and second (Layer L1)Recording Layers of a Type TL disk and aType 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.
To improve the scratch resistance, the Cover Layer optionally can be protected with an additional hard coating.Clamping is performed in the Clamping Zone.
Data can be written onto the disk with a high power focused optical beam. The data can be read with a lowpower focused optical beam, using the difference in the reflectivity of the Marks and the Spaces.
The Recording Layer(s) contain Wobbled Groove (s) with addresses,which serve as a speed control andnavigation system for the data to be written to the Recording Layer concerned.
Recording and read-out of the data is accomplished through the Cover Layer or through the total stack ofCover Layer,Recording Layers and Spacer Layers, depending on which Recording Layer is involved.
Depending on which Recording Layer is to be accessed, the optical beam passes through the transparentCover Layer (readinglwriting Layer L2 on a Type TL disk or a Type TL/D disk, or Layer L3 on a Type QL disk)or through the transparent Cover Layer, the semi-transparent Recording Layer(s) and the transparent SpacerLayer(s) (reading/writing Layer LO and LayerL1 on aType TL disk or a Type TL/D disk, or Layer LO, Layer L1and Layer L2 on a Type QL disk).
A TL disk and a QL disk also denote a Type TL disk and a Type QL disk respectively in this InternationalStandard.BS ISO IEC 30191 pdf download.