Matsushita Electric Industrial Co., Ltd.

Hiroshi Yohda

Ken Takahashi

Yoshiaki Mizoh

Nobuyuki Kaminaka

Masaru Higashionji

Eisuke Sawai

Keita Ihara

Kenji Hasegawa

Hideaki Mukae

Haruo Isaka

Hiromi Kita

Takeshi Otsuka

Seishi Sasaki

Hirofumi Uchida

Kazuo Nakamura

Keiichi Ishida

Yasushi Inoue

Hidetoshi Kotera

Syunsaku Muraoka

Kouhei Baba

Kazunori Umee

A clogging detector used for a VTR to check the recording state of a recording head without using the reproducing head. A test signal of a lower frequency than the erasing frequency is recorded before and after an information signal by means of an erasing head. Before and after recording the information signal by means of the recording head, the test signal is reproduced, the reproduction output is detected by a detecting circuit, and the level of the output is compared with a preset level by a comparing circuit. When the level is lower than the preset level, a warming is issued from a warming circuit, thus preventing a recording failure due to the clogging of the head.

Recording head clogging detection method and its device

Apparatus is adapted for recording and reproducing compressed video data in a selected one of two recording formats, of which a first format is for recording the compressed video data in N (N&gE;3, and representing an integer) number of tracks on a magnetic tape by dividing the video data into N number of groups, and a second format is for recording data, as auxiliary data independent from the compressed video data, in two of the tracks at both ends, and the compressed video data in (N&minus;2) number of the tracks. In the second recording format, the recording is carried out by setting a data length of an error correction code for sync blocks longer than a data length of another error correction code for sync blocks in the first recording format.

Magnetic recording and reproducing apparatus of helical scan type

A multitrack magnetic head for use with a magnetic tape in a magnetic recording and reproducing system includes at least two magnetic head tips disposed adjacent to each other and movable with respect to the magnetic tape. The head tips include a leading head tip for initial sliding contact with the magnetic tape and a trailing head tip for subsequent sliding contact with the magnetic tape. The leading head tip is made of a material whose wear resistance is greater than that of a material of which said trailing head tip is made. The head tips are held in good sliding contact with the magnetic tape for better recording and reproducing characteristics.

Multitrack magnetic head assembly for scanning a magnetic tape with a

A levitation phenomenon analyzer includes: a data input portion for reading data on fluid and structural components and minute structures of a device; a levitation analysis portion for solving basic simultaneous equations of the fluid and the structural components on the basis of the data; and a result output portion for outputting analytical results of the levitation analysis portion; wherein by regarding a flow path of the fluid for levitation analysis as a mean thickness of a air film or regarding the pressure of the fluid as a mean pressure, shapes of the minute structures which are independent of coordinates of nodal points are handled.

Levitation phenomenon analyzer and magnetic recording apparatus

In a magnetic head drive for a magnetic tape recorder of a helical scan system, a pair of first and second longitudinal bimorph elements fixed to a support member is connected to a flexible bridge member and a magnetic head is mounted to the bridge member. A pair of first and second electric sources supply electric voltages independently to electrodes of the first and second bimorph elements. The voltages applied to the bimorphs are controlled against a deviation from a record track in a magnetic tape to keep a protrusion quantity of the magnetic head constant for automatic tracking. In a magnetic tape recorder wherein the upper and lower drums of a rotating head scanner are fixed and the magnetic head is rotated along an elliptical orbit, the two bimorphs are controlled not only against a deviation from a record track in a magnetic tape but also to a rotation angle of the magnetic head in order to keep a protrusion quantity of the magnetic head constant.

Magnetic head drive which uses independently controlled piezo-electric

The multi-track head includes more than one head chip attached onto one head base. The head chips are respectively attached onto the divided front end parts of the head base, and the relative positions of the front end parts of the head base are adjusted so that the positions of the gap ends in the head chips are set precisely to a predetermined value, before the head chips are fixed. For these reasons, it is not necessary to adjust the position of each head chip after the head chips are arranged in a rotary cylinder. It is therefore possible to obtain a head having a size which can be accurately adjusted, regardless of the size of the head chip, even when the head chip is extremely small. A bonding material is provided between the divided front end parts to secure the front end parts and the chips mounted thereon in place after they have been displaced to align them with recording medium track locations.

Multi-track magnetic head having different height head chips

A ring-shaped magnetic head includes magnetic cores made of a metallic magnetic material having a gap therebetween and being held between non-magnetic substrates. A metallic thin film is provided bridging the gap between the magnetic cores for establishing an electrical connection between the magnetic cores. The metallic thin film is formed on a surface of the magnetic head which is opposite to a surface for contacting a magnetic recording medium.

Magnetic head

There is disclosed herein a magnetic head comprising a ring-like magnetic core composed of first and second magnetic core halves made of a ferrite and held in abutment against each other so as to form a magnetic gap therebetween and an elongated tape-contact surface extending across the magnetic gap. The magnetic core has in the tape-contact surface a channel formed to as to extend in the direction across the magnetic gap and the channel is filled with a magnetic metal material having a high-saturation magnetization. Preferably, the channel has a substantially V-shaped cross section. The magnetic gap exposed on the tape-contact surface is surrounded by the magnetic metal material and non-magnetic glass members provided at both ends of the magnetic gap. The non-magnetic glass members are provided so that the track width is constant from the tape-contact surface to an upper end of a winding hole of the ring-like magnetic core.

Magnetic head with a tape contacting surface having a metal filled

A magnetic head for the video tape recorder of azimuth recording type, which features an improved S/N ratio in the overwrite region and assures a high picture quality has a magnetic core for defining a magnetic gap in this head which is made of a plurality of magnetic materials differing in saturation flux density in the direction of track width, with the material having a higher saturation flux density being disposed on the overwriting side of the head. This arrangement permits recording to a greater depth than the depth of magnetization by previous recording to assure an improved picture quality with a higher S/N ratio.

Magnetic head for azimuth recording in a high density magnetic recording

A method of manufacturing a magnetic head includes fabricating a magnetic block having a lamination of magnetic alloy films and nonmagnetic substrates, and cutting the magnetic block into two bars to obtain magnetic core halves. A nonmagnetic film is formed on a surface of each of the core halves. The core halves are joined by adjoining the surfaces having the nonmagnetic film and then heating the thus adjoined core halves. Additionally, a magnetic field is applied rotating in a plane parallel to a plane of the magnetic alloy films. The joined core halves is then cut into a specified width, and a wire-winding window is machined therein.

Method for manufacturing magnetic head

A magnetic head having a recording capacity for sufficiently deriving performance of a high coercive magnetic tape and capable of recording and reproducing signals of very high frequencies at high efficiency. The magnetic head of the present invention includes ferromagnetic thin films and insulative thin films alternately laminated one upon another to form a multi-layered film magnetic core which constitutes part or all of a magnetic path, with the ferromagnetic thin films being so arranged that the directions of their anisotropy are different from each other, and thus, Snoek's limit, due to ferromagnetic resonance, is broken through, thus, making it possible to record and reproduce signals in an efficient manner up to high frequency band regions.

A perpendicular magnetic head of high recording and reproducing efficiency which integrally incorporates a step-up transformer. A main pole for picking up a reproduce magnetic flux from a recording medium and applying recording magnetic field thereto is formed of a magnetic thin film. A signal winding formed of a thin film is disposed in the immediate vicinity of the forward end of the main pole so as to have a high conversion sensitivity per turn with respect to the reproduce magnetic flux from the recording medium. The signal winding which itself constitutes a closed circuit interlinks a magnetic path of the step-up transformer, thereby forming a primary winding of the transformer. A secondary winding from which head output is taken out is wound in the magnetic path of the transformer.

Growing community of inventors

Hirakata, Japan

Hiroshi Yohda