Source: http://www.google.com/patents/US5724205?dq=6233682
Timestamp: 2017-10-23 23:11:39
Document Index: 16083303

Matched Legal Cases: ['art.\n1', 'art.\n2', 'art 2', 'art 3', 'art 2', 'art 4', 'art 3', 'art 5', 'art 4', 'art 6', 'art 5', 'art 6']

Patent US5724205 - Automatic tracking control device which uses different weightings with a ... - Google Patents
This invention relates to automatic tracking devices of digital VCRs which is provided to have a capability of precise control of the tracking by detecting rate of error due to variation of tracking of a rotating head. The devices comprise a pre-amplification part for amplifying reproduction signals...http://www.google.com/patents/US5724205?utm_source=gb-gplus-sharePatent US5724205 - Automatic tracking control device which uses different weightings with a number of incorrectable, correctable, and non-errors
Publication number US5724205 A
Application number US 08/545,379
Publication number 08545379, 545379, US 5724205 A, US 5724205A, US-A-5724205, US5724205 A, US5724205A
Inventors Man Chul Choi
Patent Citations (11), Non-Patent Citations (2), Referenced by (9), Classifications (6), Legal Events (8)
Automatic tracking control device which uses different weightings with a number of incorrectable, correctable, and non-errors
US 5724205 A
This invention relates to automatic tracking devices of digital VCRs which is provided to have a capability of precise control of the tracking by detecting rate of error due to variation of tracking of a rotating head. The devices comprise a pre-amplification part for amplifying reproduction signals scanned at a rotating head of a head drum to any level in reproduction, a modulation and demodulation part for restoring amplified reproduction signals in the pre-amplification part into digital signals, a format and deformat part for arraying the digital signals restored in the modulation and demodulation part to original signals, an error correction part for detecting presence of errors caused during recording in the digital signals arrayed by the format and deformat part and generating correctable and incorrectable control signals according to the rate of error detected, and an automatic tracking control part for controlling the tracking through a servo system by generating tracking data according to the rates of error obtained through addition of different weightings to each of the control signals transmitted thereto from the error correction part.
1. An automatic tracking control device of a digital video cassette tape recorder comprising:
a pre-amplification means for amplifying reproduction signals scanned at a rotating head of a head drum to any level in reproduction;
a modulation and demodulation means for restoring amplified reproduction signals in the pre-amplification means into digital signals;
a format and deformat means for arraying the digital signals restored in the modulation and demodulation means to an original digital signal;
an error correction means for correcting errors in the output data arrayed by the format and deformat means according to the correction result, detecting the type of errors within a few seconds and generating correctable and incorrectable control signals according to the rate of errors detected; and
an automatic tracking control means for controlling the tracking through a servo system by generating tracking data according to the rates of error obtained through addition of different weightings to each of the control signals transmitted thereto from the error correction means;
said automatic tracking control means including a first, a second and a third counter means for counting the control signals having no errors, having errors but correctable and having errors incorrectable of the error correction means, a weighting addition part for making the difference between the counter number of incorrectable errors, correctable errors and non-errors larger than they really are by adding a larger weighting value to the outputting value of each counter, a tracking selection means for selecting least error portions of the outputting value of said weighting addition part.
2. The automatic tracking control device as claimed in claim 1, wherein, in recording, the error correction means corrects errors of the digital signals, the format and deformat means and the modulation and demodulation means modulates the corrected signals into analogue signals, and the pre-amplification means amplifies the modulated signals and records on a tape through a video head and an audio head.
This invention relates to digital VCRs(Video Cassette Tape Recorders), more particularly to automatic tracking devices of digital VCRs which is provided to have a capability of precise control of the tracking by detecting rate of error due to variation of tracking of a rotating head.
In general, in an analogue VCR, rotating heads attached on a head drum trace a recording medium and scan reproduction signals to detect envelopes, according to which envelopes, an automatic tracking control is performed by controlling speed and phase of a capstan motor.
The object of this invention is to provide an automatic tracking control device which is provided to have a capability of precise control of the tracking by adding different weightings to tracking errors according to rate of the tracking error due to tracking variations of a rotating head.
FIG. 1 shows a block diagram of an automatic tracking control device of a conventional analogue VCR.
Shown in FIG. 2 is a block diagram of an automatic tracking control device of a digital VCR according to a first embodiment of this invention including a pre-amplification part 2 for amplifying reproduction signals scanned at a rotating head of a head drum 1 to any level in reproduction, a modulation and demodulation part 3 for restoring amplified reproduction signals in the pre-amplification part 2 into digital signals, a format and deformat part 4 for arraying the digital signals restored in the modulation and demodulation part 3 to original signals, an error correction part 5 for detecting presence of errors caused during recording in the digital signals arrayed by the format and deformat part 4 and generating control signals according to the rate of error detected, and an automatic tracking control part 6 for adding different weightings to each of the control signals transmitted thereto from the error correcting part 5 according to the rate of error, and transmitting the tracking data therefrom, and a servo system 7 for controlling speed and phase of a capstan motor according to the tracking data transmitted thereto from the automatic tracking control part 6.
US4947272 * Mar 16, 1988 Aug 7, 1990 Pioneer Electronic Corporation Signal reproducing device which offsets the tracking error signal for a digital tape player
US5253130 * Apr 25, 1991 Oct 12, 1993 Deutsche Thomson-Brandt Gmbh Head track alignment arrangement in a magnetic tape recorder
1 "Video Compression Makes Big Gains", Ang et al., IEEE Spectrum, Oct. 1991, pp. 16-19.
2 * Video Compression Makes Big Gains , Ang et al., IEEE Spectrum, Oct. 1991, pp. 16 19.
U.S. Classification 360/77.13, G9B/5.204, 360/77.12
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:CHOI, MAN CHUL;REEL/FRAME:022266/0696