Hitachi Maxell, Limited

Kenichiro Yoshida

Masakazu Tani

Norihisa Yoshimoto

Yoshiyuki Makita

Kenji Tanaka

Sadamu Kuse

Akira Kato

Masao Fujita

Seigi Kawarai

Kimihiko Kaneno

A magnetic tape of the present invention includes a plurality of data bands in which a data signal can be recorded and servo pattern portions composed of a burst signal. The servo pattern portions are formed at a predetermined interval in a longitudinal direction of the magnetic tape in a plurality of data bands, and positions of the servo pattern portions formed in the respective data bands in the longitudinal direction of the magnetic tape vary. According to such a configuration, a magnetic tape can be provided, which is traced stably by the magnetic head even if the magnetic tape is deformed due to temperature and humidity.

Magnetic tape on which a servo pattern is formed

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 &#x221a;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.

Information recording apparatus

A servo signal recording apparatus and servo-signal recording method for recording a servo signal on a magnetic tape that includes a magnetic layer having a data area capable of storing data and a servo area capable of storing a servo signal, the apparatus including a transportation unit for transporting the magnetic tape; a direct current (DC) erasing unit on a downstream side in a magnetic tape transportation direction that performs DC erasure to a surface layer portion of the magnetic layer by magnetization in a longitudinal direction of the magnetic tape; and a servo signal recording unit on a downstream side of the DC erasing unit in the magnetic tape transportation direction, that rubs against the magnetic layer of the magnetic tape, and records a servo signal in the servo area by magnetization in a direction opposite to a direction of the magnetization of the DC erasing unit.

Servo signal recording apparatus, servo signal recording method, and magnetic tape

A magnetic recording medium comprising a non-magnetic support, at least one primer layer formed on one surface of the non-magnetic support, a magnetic layer formed on the primer layer, and a backcoat layer formed on the other surface of the non-magnetic support, wherein the magnetic layer has a thickness of 0.30 &#x3bc;m or less and a centerline average surface roughness Ra of 3.2 nm or less, and (P&#x2212;P) is 30 nm or less and (P&#x2212;P) is 5 nm or less in which Pis an averaged height of projections of the magnetic layer, and P, P, - - - and Pare heights of the highest, the second highest, - - - and the 20th highest projections of the magnetic layer, respectively.

Magnetic recording medium comprising a magnetic layer having specific thickness, surface roughness and projections

Magnetic recording medium comprising a magnetic layer having specific thickness and projections

A magnetic recording medium comprising a non-magnetic support, at least one primer layer formed on one surface of the non-magnetic support, a magnetic layer formed on the primer layer, and a backcoat layer formed on the other surface of the non-magnetic support, wherein the magnetic layer has a thickness of 0.30 &#x3bc;m or less and a centerline average surface roughness Ra of 3.2 nm or less, and (P&#x2212;P) is 30 nm or less and (P-P) is 5 nm or less in which Pis an averaged height of projections of the magnetic layer, and P, P, - - - and Pare heights of the highest, the second highest, - - - and the 20th highest projections of the magnetic layer, respectively.

Magnetic recording medium comprising a magnetic layer having specific thickness, surface roughness and friction coefficient

A magnetic recording medium comprising a non-magnetic support, at least one primer layer formed on one surface of the non-magnetic support, a magnetic layer formed on the primer layer, and a backcoat layer formed on the other surface of the non-magnetic support, wherein the magnetic layer has a thickness of 0.30 &mgr;m or less and a centerline average surface roughness Ra of 3.2 nm or less, and (P &minus;P ) is 30 nm or less and (P &minus;P ) is 5 nm or less in which P is an averaged height of projections of the magnetic layer, and P , P , - - - and P are heights of the highest, the second highest, - - - and the 20th highest projections of the magnetic layer, respectively.

Magnetic recording medium comprising a magnetic layer having specific surface roughness and protrusions

The object of the present invention is to provide a magnetic recording medium, particularly, a tape for data backup, which is less in wear of head, small in output deterioration and high in recording density. According to the present invention, there is provided a magnetic recording medium comprising a non-magnetic support having on one side at least one non-magnetic undercoat layer and a magnetic layer in succession and on another side a back coat layer, in which the magnetic layer is an ultra-thin magnetic layer having a thickness of not more than 0.20 &mgr;m provided by adjusting a standard deviation of histogram obtained by measuring the surface roughness of the magnetic layer by a light interference surface roughness meter to not more than 0.56 nm.

Magnetic recording medium

There is provided a magnetic recording medium which comprises a substrate, a magnetic layer on one surface of a substrate and a backcoating layer on the other surface of the substrate, wherein the magnetic layer contains a magnetic metal powder having a major axis of not larger than 0.2 .mu.m and an inorganic powder having a Mohs' hardness of at least 5, and the backcoating layer contains an inorganic powder having a particle size smaller than the size of the major axis of the magnetic metal powder and which has sufficiently reduced noise at high density recording and high output required in, for example, a small size video tape with high picture quality, the magnetic recording medium in the form of a magnetic tape having a total thickness of not larger than 14 .mu.m inclusive of the substrate, the magnetic layer and the backcoating layer, and reliably maintained not to increase the noise after long term storage.

Growing community of inventors

Toyonaka, Japan

Kenichiro Yoshida