Video disk

Laser sensors Laser spray Laser surgery Laser video disks LaserVision Laser welding... 

Fig. 5. (a) Schematic of the Philips 2P Process for video disk repHcation (79) (b) configuration of a double-sided LaserVision disk where the hole at the center is not shown. S represents the transparent substrate A, the primer layer L, lacquer with picture and sound information in the form of pits M,... 

Laser detector Digital audio disks, video disks, laser-beam position sensors, distance sensors... 

Diode Semiconductor 0.33-40 0.6 (CW) 100 (P) Bar-code reading, CDs and video disks, optical communications... 

In a similar way, the video disk reconverts the signal produced by the Kerr effect on a thin film of an amorphous substance such as Tb-Fe sputtered on a substrate disk made of plastic or glass. The Tb-Fe film functions like a perpendicular magneto-optical memory... 

Digital Versatile Disk or Digital Video Disk (DVD) is invented The Nobel Prize in Chemistry is awarded to Richard Smalley, Robert Curl, and Harry Kroto for their 1985 discovery of the third form of carbon, known as buckminsterfullerene ( bucky balls ) ... 

The continuous operation of noncontinuous substrates, e.g., contact lenses, video disks, microsensors, etc., is performed by placing a certain number of substrate in an evacuation/transfer chamber, in which the evacuation is carried out and samples are transferred to the adjacent sample holding chamber in vacuum. The evacuated sample holders are placed on a conveyer one by one and pass through glow discharge zones. The coated substrates follow the reverse process at the downstream end of a reactor to be taken out in the ambient environment. Thus, the substrate charge is done in butch mode, but the LCVD process is done continuously. 

Figure 1.36. Scanning electron microscope picture showing topography of a typical video disk. The information track consists of small pits of constant width and d pth with variable length and spacing.

Figure 1.38. A double-sided video disk. Abbreviations are as follows S is the transparent substrate, A is the adhesion layer, L is the polymeric information layer with picture and sound information in the form of pits, M is the mirror coating, PR is the protective layer, and G is the adhesive layer holding both sides together. Reproduced with permission from reference 55. Copyright 1982 Philips Research Laboratories.)...

Figure 1.40. The Philips photopolymerization process for replicating video disks, (a) The liquid layer L is spread over the mold Mo by deforming the substrate S to make it slightly convex, (b) Exposure to UV light polymerizes the liquid coating, (c) The substrate unth coating is separated from the mold, (d) The information layer is coated with a mirror M and protective layer P. Reproduced with permission from reference 55. Copyright 1982 Philips Re-search Laboratories.)...

---