Ricoh Company, Ltd.

Jun Zhang

Kiyotaka Sawada

Hiroyuki Endoh

Toshiyuki Enomoto

Tatsuya Tanaka

Kyohta Koetsuka

Toshihiro Kanematsu

Mizuki Otagiri

Tsuyoshi Hashiyada

Yasunori Sugimoto

Riku Maeshiro

Yutaro Hoshino

Kiyoshi Amari

Wataru Kikuta

Tomihiro Takahashi

Hidekazu Masuo

Sho Kawakami

A liquid discharge head includes a nozzle plate, a housing, a channel, and a positioning member. The nozzle plate has a nozzle hole and a first positioning hole penetrating through the nozzle plate in a thickness direction of the nozzle plate. The housing is bonded to the nozzle plate to form a single bonded body and has a second positioning hole extending in a thickness direction of the housing. A liquid flows through the channel between the nozzle plate and the housing to the nozzle hole. The positioning member fits into the first positioning hole and the second positioning hole to position the nozzle plate relative to the housing. A length of the positioning member is smaller than a sum of a length of the first positioning hole and a length of the second positioning hole in the thickness direction of the nozzle plate, and larger than the length of the second positioning hole.

Liquid discharge head, liquid discharge device, liquid discharge apparatus, and method of manufacturing liquid discharge head

A polishing sheet includes a sheet including one side having a surface, a plurality of convex portions provided to project from the surface of the one side of the sheet, a plurality of first abrasive grains provided on an upper surface of each of the convex portions, and a plurality of second abrasive grains provided on the surface of the sheet. The second abrasive grains each have hardness higher than that of the first abrasive grains.

Polishing sheet, polishing tool and polishing method

A polishing sheet comprising a plurality of convex portions which protrudes from a sheet surface and includes an upper surface which is in parallel to the sheet surface is disclosed. A plurality of abrasive grains made by a granular porous body in which a number of primary particles are partially bonded to each other and include a void in between is arranged at least on the upper surface of the convex portion.

Polishing sheet and polishing tool

A nozzle plate includes a nozzle base; a nozzle hole to discharge droplets and formed on the nozzle base; and a water-repellent film formed on at least a liquid discharging surface of the nozzle base. The nozzle base is formed of a stainless material that includes a surface layer area on which the water-repellent film is formed. The surface layer area has a higher chrome density than the chrome density of the stainless material itself, and a ratio of Cr to Fe (Cr/Fe) in the surface layer area is equal to and more than 0.8. The nozzle plate production method as such includes polishing with a polishing agent a surface of the nozzle base; removing Fe in a surface layer area of the stainless material by etching using a polishing agent; and combining chrome with oxygen.

Nozzle plate, nozzle plate production method, liquid discharge head, and image forming apparatus

A surface polishing method that polishes the surface of a hard brittle material, such as a glass substrate, an oxide film of a silicon wafer, and a ceramic substrate is disclosed. In the surface polishing method, a fixed abrasive grain polishing tool is used, in which the fixed abrasive grains are a porous substance of granule type in which many primary grains are partially bonded with each other with spaces among them without having the binder therein. The surface polishing method includes the steps of supplying loose abrasive grain slurry between the fixed abrasive grain polishing tool and a surface to be polished of an object, and dressing the top parts of the abrasive grains of the fixed abrasive grain polishing tool which parts contact the surface to be polished of the object by the supplied loose abrasive grains.

Surface polishing method and apparatus thereof

An abrasive grain including a porous particle material in which a large number of secondary particles contain gaps between primary particles bonded to each other. The secondary particles are produced by growing primary particles into secondary particles, which are formed by cohesion of a large number of primary particles, via a heat treatment at a temperature sufficient to form necks at bonding points between the primary particles.

Abrasive grain and method for producing it, polishing tool and method for producing it, grinding wheel and method for producing it, and polishing apparatus

An abrasive grain including a porous particle material in which a large number of fine particles for cutting edges form gaps partly among them and bond loosely each other. The particles for the cutting edges are produced by growing primary particles in secondary particles, which are formed by cohesion of a large number of primary particles, with a heat treatment at a temperature of forming necks at bonding points among the primary particles.

Growing community of inventors

Kanagawa, Japan

Jun Zhang