LG Electronics GSA-4168B, GSA-4165B, GSA-4167B service manual Glossary

	GLOSSARY
ATIP	Absolute Time in Pre-groove. With an additional modulation of the “Wobble”, the “Groove” contains a time
	code information.
Wobble	The pre-groove in the Disc is not a perfect spiral but is wobbled.
	With : – A typical amplitude of 30 nm
	– A spatial peried of 54~64 µm
CW	Continuous Wave. The laser light output is at a constant level.
DOW	Direct Over-Write. The action in which new information is recored over previously recorded information in
	CD-RW disc.
Overwrite	The action in which new information is recorded over previously recorded information.
(Pre-)Groove	The guidance track in which clocking and time code information is stored by means of an FM
	modulated wobble.
Land	Land is characterized in the following way:
	When radial signals are concerned,land is defined as the area between the grooves.
	When HF signal are concerned,land is defined as the area between the marks(pits) in tangential
	direction.
Hybrid Disc	A Multisession disc of which the first Session is mastered. On a hybrid disc, recorded and
	mastered information may co-exist.
Mastered	Information,stored as pits on the disc during the manufacturing process of the disc.
Information	(when making the master)
OPC	Optimum Power Control. Procedure is determined optimum recording power according to CD-
	R/RW Media in recording start step.
ROPC	Running OPC. The purpose is to continuously adjust the writing power to the optimum power
	that is required.
	When the optimum power may change because of changed conditions of disc and change in
	operating temperature.
Jitter	The 16 value of the time variation between leading and trailing edges of a specific (I3 … I11) pit
	or land as measured by Time Interval Analysis.
Deviation	The difference between a fixed value of Pit length and Land length.
TOC	Table Of Contents : in the Lead-in Area the subcode Q-channel contains information about the
	Tracks on the disc.
Packet	A method of writing data on a CD in small increments.
Writing	Two kinds of packets can be written : Fixed-length and Variable-length.
Write	The shape of the HF write signal used to modulate the power of the laser.
Strategy	The Write Strategy must be used for recordings necessary for disc measurements.
Information	Wobble, ATIP, Disc Identification, Write Power, Speed Range OPC Parameters, etc are
Area	recorded in the Information area of CD-RW Disc
Finalization	The action in which (partially) unrecorded or logically erased tracks are finished and the Lead-in
	and/or Lead-out areas are recorded or overwritten with the appropriate TOC subcode.
Logical Erase	A method to remove information from a disc area by overwriting it with an EFM signal containing
	mode 0 subcode
	A logically erased area is equivalent to an unrecorded
Physical Erase	The action in which previously recorded information is erased by overwriting with a CW laser
	output.
	After a Physical Erase action, the erased area on the CD-RW disc is in the unrecorded state
	again.
Session	An area on the disc consisting of a Lead-in area, a Program area, a lead-out area.
Multi session	A session that contains or can contain more than one session composed Lead-in and Lead-out

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