Nichias Corporation

Zenith, LLC

Nichias Co., Ltd.

Other

Hitachi Global Storage Technologies Netherlands B.v.

Tatsuo Takagi

Kohichi Kimura

Osamu Horiuchi

Yoshiyuki Motoyoshi

Kouichi Kimura

Yoshihisa Miyahara

Hiromi Furuya

Kenichi Shibata

Isami Abe

Nobuya Tomosue

Shigeru Nakama

Tomohiko Hara

Hideki Ohzeki

Takeshi Kuboyama

Kazuyuki Ishibashi

Shunichiroh Ohta

Yousuke Suganuma

Yoshihiro Goto

Toshihisa Okabe

Munehiko Fukase

Masanori Ono

Embodiments of the present invention provide accurate pitch control of a servo write track. A Self-Servo-Write (SSW) according to an embodiment of the present invention determines a reference APC by reading a mark formed on the recording surface corresponding to the propagation head prior to starting the product servo pattern writing. The accurate size of the mark in the radial direction is known previously. The reference APC is for determining the track pitch, and by using the mark with the determined size, the product servo patterns can be written with a desired and accurate track pitch.

Method of writing pattern on magnetic disk and device therefor

An oil-coating roller constituted mainly of an oil-retaining layer around a central core and an oil-coating control layer surrounding the oil-retaining layer is provided which does not require a sealing treatment for prevention of oil leakage from the roller end face, and has a long service life. The oil-retaining layer is formed by winding in layers a nonwoven fabric which exhibits an oil-sucking height of not less than 60 mm and has an oil permeability of 40 g/cm/hr.

Oil-coating roller

An oil application device having an oil application amount control layer bonded to an oil retaining member for retaining application-use silicone oil using the mixture of adhesive and mixture-use silicone oil. The ratio (V )/(V ) of a viscosity (V ) of the mixture-use silicone oil at 25&deg; C. to a viscosity (V ) of the application-use silicone oil at 25&deg; C. ranges from 50/1 to 1/10. By using the oil application device, releasing oil can be applied to a thermal fixing roller uniformly. The oil application amount control layer does not peel off or is not displaced during operation, and no oil exudes during nonuse.

Oil application device having oil application amount control layer bonded to oil retaining member for retaining application-use silicone oil using mixture of adhesive and mixture-use silicone oil

In an oil application roller having an oil retaining member made of a hollow cylindrical porous formed body provided with an oil application layer on the outer periphery and that supplies a fixing roll with lubricant oil retained in the oil retaining member, the porous formed body is made of an inorganic material having micro-diameter voids and pores inside, at least a part of the micro-diameter voids communicates with a surface of the porous formed body and the pores, and at least a part of the pores communicates with a surface of the porous formed body through the micro-diameter voids. Also, if permeability resistance is 100 to 6,000 Pa.s/m , no oil leak occurs during transportation and storage, the amount of the lubricant oil supplied to the fixing roll can be controlled and a uniform amount of lubricant oil can be supplied despite its compact and simple structure, the utilization rate of the lubricant oil can be enhanced. Further, if a pressure buffer device is provided between the hollow portion and the atmosphere, ill effects from oil leak and thermal expansion can be prevented.

Oil application roller

An oil coating roller comprising a porous round-rod-like molded product, a heat-resistant fiber felt layer provided on an outer circumference of the porous round-rod-like molded product, and a porous film applied onto an outer circumference of the felt layer. The porous round-rod-like molded product contains heat-resistant fibers bound to each other by a binder, and has fine communicating voids free from the binder among the fibers and evenly distributed pores having a pore size in a range of from 0.05 to 2 mm and a total void percentage in a range of from 30 to 90%. The porous round-rod-like molded product is impregnated with silicone oil. The heat-resistant fiber felt layer has a thickness in a range of from 0.5 to 5 mm. The porous film has a thickness in a range of from 15 to 130 &mgr;m, a mean pore size in a range of from 0.1 to 3.0 &mgr;m, a porosity in a range of from 60 to 90% and an air permeability in a range of from 3 to 1500 sec per 100 cc.

Oil coating apparatus

An oil holding cylinder for an oil coating roller is provided. The cylinder includes at least a cylindrical non-sintered molded body, which is formulated from a mixture of at least ceramic fiber and an organic binder. In addition, the mixture can further include clay, an inorganic binder, or a combination thereof. The molded body preferably has a porosity in a range of about 30% to about 70%. In operation, the oil holding cylinder disclosed herein can stably and uniformly supply oil to the fixing rollers and the like for an extended period of time, while preventing offset.

Oil holding cylinder for an oil coating roller and method therefor

A coating fluid holding member including a porous molded body which is formed of heat-resistant fibers (or a mixture of heat-resistant fibers and a filler) bound to each other with a binder, has intercommunicating pores having an average pore size of 1 to 500 .mu.m, and has a porosity of 20 to 90%, and a coating fluid holding member including a porous molded body which is formed of heat-resistant fibers bound to each other with a binder, contains fine intercommunicating interstices between fibers and uniformly distributed pores having a diameter of 0.05 to 2 mm, and has a porosity of 30 to 90%. The holding member has a high fluid holding capacity for its volume and releases the coating fluid, such as a parting agent, an oil or a coating compound, in a stable manner for an extended period of time.

Process for producing a coating fluid holding member

To provide an oil supplying means for an oil coating roller, by which oil can be supplied stably for a long time while preventing offset, a cylindrical non-sintered molded body which is a mixture of ceramic fiber and clay is used as an oil holding member in an oil coating roller.

Disclosed is an oil coating roller composed of a coating fluid holding member comprising a porous hollow cylindrical molded body impregnated with a coating fluid, such as silicone oil, with a driving shaft inserted through the hollow portion thereof, both ends of the coating fluid holding member being fixed to the driving shaft, and felt fabricated of heat-resistant fiber wounded around the outer surface thereof, wherein the porous hollow cylindrical molded body is fabricated of heat-resistant fibers bound to each other with a binder and has an average pore size of 15 to 50 .mu.m and a porosity of 50 to 80%. The oil coating roller can be produced with ease, stably feeds the coating fluid for an extended period of time, and is particularly suitable for applying silicone oil to a fixing roller of an electrostatic copying machine.

Coating fluid holding member and oil coating roller using the same

A refractory for use in firing ceramics has a ceramic coating applied by plasma spraying onto the surface of a heat-resistant lightweight shaped article containing heat-resistant lightweight shaped article containing heat-resistant inorganic fibers. The shaped article is composed of highly aluminous short fibers not longer than 2,000 .mu.m or a mixture thereof with an aluminous refractory powder as bound to each other by means of aluminous binder, the shaped article not containing free silica.

Refractories for use in firing ceramics

A lightweight refractory is disclosed which is a shaped porous body having refractory particles and aluminous short fibers bound to each other with mullite. The crtystalline structure of the refractory is chiefly composed of mullite and corundum. The mullite content is at least 12 mol % of the sum of mullite and corundum. The refractory is substantially free of free silica.

Growing community of inventors

Hamamatsu, Japan

Tatsuo Takagi