Laserdisk preservation (Algemeen)

door Maurice , Dordrecht, 21-11-2023, 01:18 (369 dagen geleden) @ Roland Huisman

Manufacture_of_Laservision_Discs_Philips-Technical-Review-1982.pdf

Plaatje en tekst laten begrijpen dat het weer losnemen van de platen wel een ding is.
Zie de lagen, de werkelijke informatie laag is dus maar 10-30um dik.

The Philips LaserVision system
The LaserVision disc now being produce dat Black-
burn consists of two halves,with an external diameter
of 300mm and a central hole of diameter35mm,
bonded 'back-to-back' with an adhesive. The two disc
halves consist of a transparent substrate coated on
one side with a primer layer and a lacquer layer in
which the picture and sound information is recorded;
see fig.1. Since the information is read from the disc
in a reflection process, a thin highly reflective metal
`mirror' is applied to this 'information' layer. This
in turn is coated with a protective layer to prevent
chemical and mechanical damage,which might occur
during later stages in the manufacture. The protective
layer also serves as a base for the adhesive that bonds
the two discs together to form the complete video
disc.The information is recorded between the radii of
55 and 145mm, a saspiral track of small pits 0.12um
deep and 0.4 um wide; see fig.2. The length of the pits
and the minimum distance between them vary between
about 0.5 and 2.0 um, and the pitch of the spiral is
1.6 um to 2.0 um.