Tdk Corporation

Tdk Electronics Company, Limited

Tdk Corporation (representative Yutaka Otoshi)

Toshihiko Ishida

Haruo Shiba

Kimio Tanaka

Masaru Ikebe

Yasuo Ohira

Masatoshi Okamura

Hideki Hirata

Takateru Satoh

Keiji Koga

Toshifumi Tanaka

Eiichi Nunokawa

Hiroshi Tanabe

Masatoshi Nakayama

Kunihiro Ueda

Hiroyuki Arioka

Yukio Miyazaki

Hitoshi Azegami

Takateru Sato

Yuji Ishikawa

Yoshio Kawakami

Masaoki Sekine

Takateru Satou

Tetuji Takamizawa

Mitsuo Watanabe

Yukio Nakazawa

A cleaning disc cartridge capable of concurrently cleaning both a magnetic head of a magneto-optical disc apparatus and an optical lens thereof without causing any error in reading of a signal. A rotating disc is provided on one surface thereof opposite to a magnetic head of the apparatus with a head cleaning member and on the other surface thereof opposite to an objective lens of the apparatus with lens cleaning members. The rotating disc includes a disc body which is provided with an inventory region defined on an inner peripheral side of a lens cleaning member arrangement region, a reproduction-only region defined on an outer peripheral side of the lens cleaning member arrangement region, and an information recording and reproducing region outside the reproduction-only region.

Cleaning disc cartridge

An optical disk is configured as comprising a pair of substrates one of which has a recording layer borne thereon, the substrates being joined together through an adhesive so that the recording layer is interposed therebetween. In one form, one of the substrates is of glass, the other substrate is of a resin. In another form, both the substrates are of glass or resin. Delamination is prevented by using the adhesive having a specific glass transition temperature, Young's modulus, and dynamic loss factor.

Optical disk

A disc molding apparatus capable of satisfactorily accomplishing release of a molded disc without any trouble to eliminate deformation of the disc during the release and improve quality, reliability and productivity of the disc. In the disc molding apparatus, an air inlet port is provided in proximity to an outer stamper holder of an outer ring for supplying air toward a central region of a disc molded in a cavity of a mold body from a periphery of the disc and a communication passage communicating with the air inlet passage is provided at the outer ring, so that air may be more uniformly blown against the disc during release of the disc from a stamper.

Disc molding apparatus

The rear surface of a stamper for use in the manufacture of optical disks should be polished to precision. A length of abrasive tape is fed across the stamper in pressure contact with the rear surface of the stamper through a pressure roller having a rubber sleeve with a hardness of up to 80 degrees as measured according to ASTM D 2240 type A while the stamper is rotating.

Polishing of the rear surface of a stamper for optical disk reproduction

A mold including a cavity the inner surface of which is at least partly coated with a layer selected from a diamond-like film and layers of fluorine and fluorine compounds. The mold is manufactured by a method which comprises placing at least a part of the mold which constitutes the surface portion of the mold cavity in a vacuum film-forming chamber, introducing a hydrocarbon gas into the chamber, ionizing the gas, and then evaporating it onto a desired surface portion of the mold, thus forming a diamond-like film over the mold portion. The mold portion is surface-treated by ionizing a low-molecular-weight fluorine compound into a plasma, forming a fluorine polymer film from the plasma on at least a part of the cavity surface, while applying a bias voltage to the plasma.

Molds having wear resistant release coatings

A disc molding apparatus capable of satisfactorily accomplishing the release of a molded disc without any trouble to eliminate deformation of the disc during the release and improve quality, reliability and productivity of the disc. In the disc molding apparatus, an air inlet port is provided in proximity to an outer stamper holder of an outer ring for supplying air toward a central region of a disc molded in a cavity of a mold body from a periphery of the disc and a communication passage communicating with the air inlet passage is provided at the outer ring, so that air may be more uniformly blown against the disc during the release of the disc from a stamper.

A hub to be attached to the central portion of a recording medium comprises a flat plate-like body made of a metallic material, and an annular resinous body firmly attached to the flat plate-like body by insert-molding, wherein at least one bent portion with an opening for connecting the annular resinous body to the flat-plate-like body is formed in the flat plate-like body so that the opening is in parallel to the upper or lower surface of the flat plate-like body.

Hub for a disk type recording medium

A disc cartridge capable of preventing a recording surface section of a disc from being contacted by a casing and placing the disc at a proper position in the casing without damaging and polluting, to thereby ensure the safe and smooth operation of the disc in the casing. The disc cartridge includes a pair of disc receivers each of which is formed therein with a recess for receiving a peripheral portion of the disc. The recess has an end surface contacting an outer periphery of the disc, which is formed into a substantially sideways V-shape of which an apex is positioned at substantially a center of the end surface to position the outer periphery of the disc at the center of the end surface.

Disc cartridge

This invention relates to a tape protecting cover of a video tape cartridge, especially to a shaft having a groove the shaft being formed integrally with the tape protecting cover. A first and second molds 12 and 14 divided by the parting line 20 have dents 16 and 18 respectively to form a space when both molds are joined. The dent 16 of the first mold 12 is provided with a rectangular pin 22 for forming a groove so that its one end surface 22a may abut to the end wall surface 16a of the dent 16. The front side 22b of the rectangular pin 22 extends so as to extrude to the dent 18 of the mold 14, and is constructed to form an inclined surface 22c between the end surface 22a of the rectangular pin 22 and itself. The end wall surface 18a of the dent 18 of the second metallic mold 14 is formed to have a same inclined angle .theta. as the rectangular pin so as to abut to the inclined surface 22c of the rectangular pin 22 when both metallic molds are joined.

A Shaft having a groove for a video tape cartridge and metallic molds

A mold for stepwise molding by two or more injection shots of different materials or colors comprises fixed and movable mold halves and a slide core which combinedly form a first cavity and, with the slide core moved down, a second cavity for the shots to form a molded article of unitary structure, such as a housing section of an audio cassette tape with a see-through window. Ribs are formed on the slide core along its peripheries, and a land projection is formed on the inner side of the fixed mold half to be in contact with the molding surface of the slide core recessed with respect to the ribs. The inner peripheral wall faces of the ribs and the peripheral wall faces of the land projection of the fixed mold half are spaced apart to remain out of contact during mold clamping.

Mold

In a case for holding a magnetic tape cassette comprising a lid and an inner enclosure formed of a planar bottom wall portion having a pair of spool stops projecting inwardly from its inner side and edge walls formed along the periphery of the bottom portion excepting a part of it and extending perpendicularly to that portion, one of the edge walls being formed with a thumb recess, the inner enclosure is made by a mold with a gate inlet so that the bottom portion has a gate mark on its outer side at a point where that portion meets the edge wall formed with the thumb recess, at a right angle to it, and underneath the recess. The planar bottom portion and peripheral edge walls are molded together in one piece. The gate mark is located at the point on an extension of a line intersecting the midpoint of a straight line that connects the two spool stops, on the outer side of the planar bottom portion, and extending at right angles to the straight line.

Molded magnetic tape cassette case having improved gate mark location

A magnetic tape cassette comprises upper and lower casings to be assembled together and tape reels held in the assembled casings wherein the lower casing is provided with first reference holes at positions corresponding to reference pins formed in a magnetic tape cassette deck, to be fitted into the pins and second reference holes are formed in the upper casing so as to have the same center axis as that of the first reference holes, dimensions of all structural elements of the upper and lower casings being determined on the basis of both the reference holes.

Magnetic tape cassette casing

A hub of a tape cassette comprising a generally circular outer ring portion (6), an inner ring portion (8) concentric with the outer portion and a generally annular rib (10) connecting the outer and inner ring portions, wherein said annular rib is formed so that its wall thickness increases continuously from a position (A) adjacent to a gate portion (G) for injection molding towards a portion (B) most apart from the gate portion, along the circumferential direction.

Growing community of inventors

Komoro, Japan

Toshihiko Ishida