Hitachi, Ltd.

Hitachi Maxell, Limited

Exabyte Corporation

Kenmei Masuda

Hidekazu Takeda

Kenji Ogiro

Nobuyuki Kaku

Hikaru Mizutani

Shinya Fujimori

Fukuyasu Abe

Tatsumi Nishijima

Atsushi Inoue

Shigemitsu Higuchi

Shigeru Yamazaki

Kazuo Sakai

Yoshimi Maehara

Fumio Takeda

Kenkichi Inada

Toshio Tsuchiya

Kuniaki Hirayama

Shigeyuki Kobata

Yoshiharu Yamashita

Fujio Tajima

Takayuki Munemoto

Hidefumi Goto

Seiji Ono

Tomokazu Ishii

Mikihisa Inoue

Toshihiko Imachi

Yoshio Uemura

Katsuhiko Izumi

Akihisa Obata

Satoshi Fujino

Sadao Hirose

Kuniako Hirayama

Nobuo Masuoka

Yoshinori Okada

Takeshi Itoh

Taichiro Yamashita

Takao Terayama

Tomomi Okamoto

Isamu Tsubono

Makoto Ibe

Noboru Katohno

Kazuyuki Kodama

Hideki Maruyama

Kyuichirou Nagai

Katsuo Konishi

Kazutoshi Konno

Toshimichi Terada

Tomoki Shoji

Kooetsu Okuyama

Mashanori Kochi

Hisashi Ichikawa

Akihiro Nakajima

Masahiko Fujishiro

Toshihiro Koyama

Kouetsu Okuyama

Kiyokazu Watanabe

Masashi Ueda

Hiroyuki Nagatomo

Shozo Yokoo

Osamu Uchiyama

A digital information reproducing apparatus using rotary heads that reproduces digital information signals recorded on a magnetic tape using magneto resistive heads installed on a rotary drum. The apparatus includes, in the fixed side of the apparatus, a magnetic tape checking circuit that checks the type of the magnetic tape; and a control signal generation circuit that generates a control signal for controlling the gain of a reproduction amplifier circuit; and on the rotary drum, a decoder circuit that identifies the control signal transmitted from the control signal generation circuit. The control signal generation circuit generates the control signal based on a checking result given by the magnetic tape checking circuit, and the decoder circuit identifies the transmitted control signal to control the gain of the reproduction amplifier circuit.

Digital information reproducing apparatus using rotary magnetic heads

According to the invention, techniques for cleaning a rotary magneto-resistive head. Embodiments according to the invention are especially useful in tape drive systems, and the like. Embodiments can provide methods and apparatus for cleaning contaminant from rotary magneto-resistive heads while guarding against damage to the head from excess cleaning, and the like. Specific embodiments can control the rotational speed of a rotary magneto-resistive head in order to facilitate cleaning operations. Embodiments include a cleaning device and a control method, and are suited for use in a magneto-resistive head mounted on a rotary cylinder of a computer tape storage unit, for example, although application of the present invention is not limited to such embodiments.

Method and apparatus for cleaning a magneto-resistive head

High reliability magneto-resistive head cleaning system

An arrangement is designed to achieve satisfactory tape contact by setting a specific ratio for the width of a drum window and the head length of a double azimuth head. The head length L is defined as the distance from the front end of the preceding head to the back end of the succeeding head. When the drum window width W is defined as the distance of the drum window in the rotary direction, the preceding head and the succeeding head are arranged within the drum window to satisfy the relation 1.15 L.ltoreq.W.ltoreq.1.28 L. When the space S1 is defined as the distance from the front end of the preceding head to the front end of the drum window, and the space S2 is defined as the distance from the back end of the succeeding head to the back end of the drum window, the preceding head and the succeeding head are arranged within the drum window to satisfy the relation 0.075 L.ltoreq.S1.ltoreq.0.14 L and 0.075 L.ltoreq.S2.ltoreq.0.14 L. According to this arrangement, the magnetic tape intrudes preferably into the space between the double azimuth head and the drum window. The magnetic tape envelopes and contacts the head surface, so that the tendency for a spacing to occur between the head and the tape is suppressed. The reproducing output is increased and stabilized in this way.

Rotary drum equipment and recording/reproducing equipment using the same

A drum base according to he invention, on which a drum of a magnetic tape recorder is mounted, comprises a substantially annular frame having a fixing surface to which the drum is fixed; at least one through hole extending through the fixing surface for allowing a screw which is to be threadably attached to a threaded hole formed in the drum to pass therethrough; and a pair of mounting surfaces provided on the fixing surface on which the drum is mounted, the mounting surfaces being located adjacent to the at least one through hole so as to have a symmetrical relationship in a circumferential direction of the annular frame with respect to the at least one through hole and within a range of a diameter dimension of the at least one through hole in a radial direction of the annular frame.

Drum base on which a drum of a magnetic tape recorder is mounted

A magnetic tape cartridge includes a casing having a tape chamber defined therein for accommodating a reeled magnetic recording tape and, also, box arms protruding outwardly from a front wall section of the casing so as to leave a loading bay that opens upwardly, frontwardly and downwardly and is thus delimited by upwardly, frontwardly and downwardly oriented open areas. The casing includes a lid assembly for selectively concealing and exposing that portion of magnetic recording tape and including front, top and rear lids operatively linked together. The front and top lids are adapted to selectively open and close the frontwardly and upwardly oriented open areas of the loading bay, respectively, while the rear lid is positioned within the loading bay and adapted to selectively open and close a space delimited between the front and the rear lid. At least first and second, generally cylindrical bosses extend between the top and bottom panels of the casing and are positioned at respective points of intersection between inner side walls of the box arms, which confront the loading bay, and the front wall section so as to partially protrude laterally into the loading bay. Each boss has a positioning hole defined axially therein so as to extend exteriorly through one of the top and bottom walls of the casing and is comprised of upper and lower boss segments aligned axially with each other. The upper boss segment has an outer diameter smaller than that of the lower boss segment.

Magnetic tape cartridge having triple lid assembly

Disclosed in an arrangement to achieve satisfactory head contact by increasing contact face pressure at a head gap and to reduce the change in time of head contact performance in a double azimuth head. Heads in a portion in which a tape is slid are respectively constructed with each head having two different arcs with a radius of curvature R1 in a first area which includes a gap, and with a radius of curvature R2 in a second area which is adjacent to the first area. A transition portion P for transitioning an arc with the radius of curvature R1 and an arc with the radius of curvature R2 is located in the direction of its adjacent head based upon a contact point Q on R1 of a common tangent drawn from an arc forming a periphery of a rotating drum to a circle formed by R1. The relationship between the radiuses of curvature in two areas is set to R1&gt;R2. As the area in which a tape is in contact can be reduced, contact face pressure by the tape on a gap can be increased, satisfactory head contact can be obtained and as a contact area with a tape is wide to some extent, a change in time of contact performance can be reduced.

Rotary head and recording/reading apparatus provided with rotary head

A magnetic tape recording and reproducing plug-in unit including a case with a front plate having an insertion opening through which a magnetic tape cassette is inserted, a bottom plate, a top plate, and a pair of side plates each formed with a pair of guide slots arranged for guiding the cassette to a loading position. The slide plates are attached to the side plates so as to be slidable within the case, each slide plate formed with a pair of cam slots arranged for moving the cassette to the loading position. A cassette holder is disposed inside the pair of slide plates for holding the cassette and has pins extending through the cam slots into the guide slots of the side plates. A recording and reproducing device is mounted on the bottom plate. A driving device drives the slide plates. An electronic circuit is disposed at the rear of the recording and reproducing device. Each of the guide slots has a horizontal guide slot portion extending depthwise and a vertical guide slot portion extending downward from the horizontal guide slot portion. Each of the cam slots has a horizontal cam slot portion extending depthwise and an oblique cam slot portion extending obliquely upwards from a rear end of the horizontal cam slot portion.

Magnetic tape recording and reproducing plug-in unit

As a method of increasing the storage capacity of a magnetic recording and reproducing apparatus for recording and reproducing information to and from a magnetic tape in a cartridge, there is a helical scan recording method in which the magnetic tape is diagonally wound around a drum which rotates a magnetic head. With an apparatus adapted to this method, the disposition of the cartridge and the take-up reel for taking up the magnetic tape on the same plane arises a necessity of considerably bending the magnetic tape at the drum portion and, accordingly, the magnetic tape is damaged. In order to prevent the damage of the foregoing type, the tape passage surface from the cartridge to the drum and the tape passage from the drum to the take-up reel are formed by an angle at which the direction in which the magnetic tape is moved is changed due to winding of the magnetic tape around the drum so that the magnetic tape is not bent excessively. A threading device capable of three-dimensionally controlling the position of the magnetic tape in accordance with a predetermined tape passage is provided for the apparatus structured as described above. The threading device is formed by a link mechanism to be moved along the locus of a cam groove so that the three-dimensional position control can be performed.

Magnetic recording and reproducing apparatus

In a rotary head drum of a recording/reproduction apparatus, for smoothly holding a magnetic tape over a guide step provided on a lower drum to guide the magnetic tape, part of a chamfer formed in the guide step is formed as a large chamfer in which a chamfered amount is larger than that of the remaining part of the chamfer. With the provision of the large chamfer, even if the lower edge of the magnetic tape deviates from the guide step when the tape is wound over or unwound from the drum, damages of the magnetic tape can be prevented. Therefore, the position and attitude control of tape withdrawing members can be greatly simplified and the magnetic tape can always run stably while being restricted in its position by the guide step. In the process of machining a tape running surface on the drum, by increasing the feed distance of a blade in the part of the chamfer where the large chamfer is to be formed by chamfering the guide step with a large chamfered amount, in comparison with the feed distance set in the remaining part of the chamfer, the large chamfer and the small chamfer can be both machined at the same time, resulting in simplified machining steps.

Tape guide structure of rotary head drum in recording/reproduction

An optical recording and reproducing system has an optical recording and reproducing head driving arrangement including an optical pick-up and has an optical recording medium provided between the recording heads. The optical recording and reproducing head is mounted on a rotating arrangement. The head scans tracks while a relative position of the recording medium and rotating arrangement is changed. Each track has an address recorded at the beginning of scanning and a hold signal at the end of scanning. The recording and reproducing heads are separated one track. The recording head makes recording while the reproducing head makes reproduction. In the recording or reproducing mode of operation, the track address is looked. If wrong, it is corrected. The hold signal is detected to operate a tracking device and focusing device. Scanning the next track is determined by the address before tracking is made for recording or reproduction.

Optical recording and reproducing system

A tape run control unit in the magnetic recording/reproducing apparatus is provided with a discrimination element and a control element. The discrimination element detects a stand-by time until a signal to be recorded is received in repositioning of the tape and generates a discrimination signal for discriminating the length of the stand-by time. The control element controls tape run driving unit such as a capstan motor during the reposition and controls the stop position of the tape such that a magnetic head scans the portion of the tape where no data is recorded. After completion of repositioning, furthermore, the control element works according to a discrimination signal so as to select the stop mode which involves the release of pinch roller when the stand-by time is long and to select the mode for simply stopping only the capstan when the stand-by time is short.

Magnetic recording and reproducing apparatus with repositioning stop mode

A cassette loading mechanism for loading either a smaller tape cassette or a larger tape cassette into a recording/reproducing apparatus, having apparatus for causing the large cassette to avoid obstructions in a cassette holder during insertion of the large cassette and of enabling the stable insertion of the larger tape cassette in the cassette holder. The cassette loading mechanism has a cassette holder provided with contact members disposed so as to engage only the larger tape cassette and so as to move members provided on the cassette holder for use with the smaller tape cassette to a retracted position. The member for use with the smaller tape cassette and the contact member are formed in an integral unit to ensure the correct operation of the cassette loading mechanism.

Cassette loading mechanism for recording and playback apparatus

A tape guide device having apertures formed in two tape-winding surfaces of non-rotatable curvature portions. A tape restriction is provided at a connecting portion of the tape guide device interconnecting the curvature portions. A flange is provided on one of the curvature portions for movement along an axis thereof to adjust the height thereof. The flange has an outer diameter greater than that of the one curvature portion. The curvature portions are integrated with each other. According this, an air film is generated between the tape and the tape-winding surfaces by discharging air from the apertures, thereby reducing the friction coefficient between the tape and the tape-winding surfaces to suppress the increase of tape tension. The tape is restricted to fluctuate in the direction of width. Further, the attitude and relative positioning between the curvature portions can be secured with high precision. As a result, the tape load during the tape running is reduced, thereby stabilizing the tape running and prolonging the lifetime of the tape.

Pneumatic static guide for a tape

Growing community of inventors

Yokohama, Japan

Kenmei Masuda