IP Library › Granted Patent US 7,961,423
Granted Patent B2
US 7,961,423 · App. 12/479,120 · Granted Jun 14, 2011

Information recording apparatus

Assignee: Hitachi Maxell, Ltd.
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Quick Facts
Patent No.
US 7,961,423
App. No.
12/479,120
Granted
Jun 14, 2011
Kind
B2
Abstract

The information recording apparatus of the present invention includes N servo heads. Servo signals outputted respectively from the servo heads are delayed by a delay circuit such that the peaks of the waveforms of the servo signals coincide with each other. The delayed servo signals are added up by an adder. Thus, the output level of the servo signal can be increased by N times and the S/N ratio of the servo signal can be also increased by √N times. As a result, the precision of PES improves and the amount of off-track can be reduced. Therefore, even if a magnetic layer in magnetic tape has a small thickness, it is possible to prevent the decline of the output level of the servo signal and the S/N ratio.

Claims (14)

1. An information recording apparatus capable of carrying out tracking servo control by reading with a servo head servo stripes recorded on magnetic tape with an inclination in a longitudinal direction of the magnetic tape, the information recording apparatus comprising:

two servo head groups each provided on both sides of a data head group, each of the servo head groups being composed of N servo heads (N≧2),

the N servo heads aligned in a width direction of the magnetic tape;

a delay means for delaying N servo signals reproduced by the N servo heads for a predetermined time;

an adding means for adding up N servo signals outputted from the delay means;

a signal processing means for generating tracking information from a servo signal outputted from the adding means; and

a delay time control means for controlling a delay time of the delay means,

wherein the delay time control means controls the delay time of the delay means so that peak timings of N servo signals with a time lag reproduced by the N servo heads coincide with each other.

2. An information recording apparatus capable of carrying out tracking servo control by reading with a servo head servo stripes recorded on magnetic tape with an inclination in a longitudinal direction of the magnetic tape, the information recording apparatus comprising:

N delay means for delaying a servo signal reproduced by the servo head for a predetermined time, the N delay means being connected to each other in series;

an adding means for adding up a servo signal reproduced by the servo head and N servo signals outputted respectively from the N delay means;

a signal processing means for generating tracking information from a servo signal outputted from the adding means; and

a delay time control means for controlling a delay time of each of the delay means,

wherein the delay time control means controls the delay time of each of the N delay means so that the delay time coincides with a period of the servo stripes.

Assignments (2)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Sep 29, 2017
From: HITACHI MAXELL, LTD.
To: FUJIFILM CORPORATION
Reel/Frame 044053/0281 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jun 10, 2009
From: TANAKA, KENJI; YOSHIDA, KENICHIRO; KUSE, SADAMU
To: HITACHI MAXELL, LTD.
Reel/Frame 022803/0802 →
Priority Claims (2)
JP 2008-154157 · Jun 12, 2008 · national
JP 2008-160564 · Jun 19, 2008 · national
Continuity (1)
Related Publication 20090310251A1 · Dec 17, 2009