Shin-etsu Chemical Co., Ltd.

Konica Minolta, Inc.

Tachikawa Corporation

Kddi R&d Laboratories, Inc.

Yokogawa Electric Corporation

Hajime Nakamura

Koichi Hirota

Takehisa Minowa

Tetsuya Kume

Koji Miyata

Kazuaki Sakaki

Masanobu Shimao

Tetsuya Ohashi

Yuhito Doi

Hiroaki Nagata

Takahiro Hashimoto

Koji Sato

Eiji Kawai

Takayuki Warabino

Masayuki Kamata

Masakatsu Honshima

Hideaki Iwashita

Junya Fukuda

Shinji Ota

Masayoshi Ohashi

Daisuke Morikawa

Naoki Watanabe

Tadao Nomura

Makoto Ui

Hideo Isohara

Masanori Okada

Masaya Yamaguchi

Mikio Yoshida

Shinichi Kawaguchi

Hiroki Iida

Seiya Abo

Kazuya Fukui

Yoshiyuki Hadano

Tadashi Okamura

Shouichi Yamazaki

Yuuji Gouki

Michihiro Oida

Shojiro Uehara

Shoichi Yamazaki

Provided is a magnetic refrigeration material whose magnetic transition temperature has been adjusted with high accuracy and which includes at least a first predetermined magnetic refrigeration material and a second predetermined magnetic refrigeration material which differs from the first magnetic refrigeration material. The absolute value of the difference between the magnetic transition temperature of the present magnetic refrigeration material and a target magnetic transition temperature is 0.7 K or less. The content of the first magnetic refrigeration material and the content of the second magnetic refrigeration material are determined by the magnetic transition temperatures of the first magnetic refrigeration material and the second magnetic refrigeration material and by a target magnetic transition temperature of the magnetic refrigeration material.

Method for producing magnetic refrigeration material, and magnetic refrigeration material

A drive circuit of a recording head having a recording element is provided. The drive circuit supplies a load element for recording operation of the recording element with an output signal of electric power according to operation of the load element. The drive circuit includes a voltage amplifier that amplifies a voltage of an analog drive waveform signal for operation of the recording element to generate a drive voltage signal. The voltage amplifier includes amplifiers. Among the amplifiers, at least one of subsequent-stage amplifiers which are a second and subsequent amplifiers from an upstream side includes a signal feedback unit that returns a signal to be output to an input side of the subsequent-stage amplifiers.

Drive circuit of recording head and image recorder

There are provided a method for producing a magnetic refrigeration material whose magnetic transition temperature can be adjusted with high accuracy, and a magnetic refrigeration material whose magnetic transition temperature has been adjusted with high accuracy. The magnetic refrigeration material production method of the present invention includes the steps of: preparing a first predetermined magnetic refrigeration material and a second predetermined magnetic refrigeration material which differs from the first magnetic refrigeration material; and mixing the first magnetic refrigeration material and the second magnetic refrigeration material to obtain a third magnetic refrigeration material. The content of the first magnetic refrigeration material and the content of the second magnetic refrigeration material in the third magnetic refrigeration material are determined by the magnetic transition temperatures of the first magnetic refrigeration material and the second magnetic refrigeration material and by a target magnetic transition temperature of the third magnetic refrigeration material. The magnetic refrigeration material of the present invention includes at least a first predetermined magnetic refrigeration material and a second predetermined magnetic refrigeration material which differs from the first magnetic refrigeration material. The absolute value of the difference between the magnetic transition temperature of the present magnetic refrigeration material and a target magnetic transition temperature is 0.7 K or less.

Provided is a rare earth sintered magnet in which a multi-layer main phase particle having multiple layers including a layer 1 having Rconcentration, represented by at %, higher than that of a center of the particle, a layer 2 which is formed on the outside of the layer 1 and has Rconcentration lower than that of the layer 1, and a layer 3 which is formed on the outside of the layer 2 and has Rconcentration higher than that of the layer 2 is present at least in a portion in the vicinity of a surface of the main phase particle within at least 500 &#x3bc;m from a surface of the sintered magnet body.

Rare earth sintered magnet

R&#x2014;Fe&#x2014;B sintered magnet has a main phase containing R(Fe,(Co))B intermetallic compound and a grain boundary phase. The inter-particle grain boundary includes an expanded width part that is surrounded by a narrow width part at which the inter-particle width is 10 nm or less and that has a structure distended in the inter-particle width direction as compared with the grain boundary width of the narrow width part; the inter-particle width at the expanded width part is at least 30 nm; Fe/R ratio in the expanded width part is 0.01-2.5; the main phase includes, in the surface part thereof, an HR-rich phase represented by (R',HR)(Fe,(Co))B (R&#x2032; represents rare-earth elements excluding Dy, Tb, and Ho, and that essentially include Nd; and HR represents Dy, Tb, and Ho); the contained amount of HR in the HR-rich phase is higher than that in the central part of the main phase.

R&#x2014;Fe&#x2014;B sintered magnet and production method therefor

An R&#x2014;Fe&#x2014;B base sintered magnet is provided comprising a main phase containing an HR rich phase of (R',HR)(Fe,(Co))B wherein R&#x2032; is an element selected from yttrium and rare earth elements exclusive of Dy, Tb and Ho, and essentially contains Nd, and HR is an element selected from Dy, Tb and Ho, and a grain boundary phase containing a (R&#x2032;,HR)&#x2014;Fe(Co)-Mphase in the form of an amorphous phase and/or nanocrystalline phase, the (R&#x2032;,HR)&#x2014;Fe(Co)-Mphase consisting essentially of 25-35 at % of (R&#x2032;,HR), 2-8 at % of Mwhich is at least one element selected from Si, Al, Mn, Ni, Cu, Zn, Ga, Ge, Pd, Ag, Cd, In, Sn, Sb, Pt, Au, Hg, Pb, and Bi, up to 8 at % of Co, and the balance of Fe. The HR rich phase has a higher HR content than the HR content of the main phase at its center. The magnet produces a high coercivity despite a low content of Dy, Tb and Ho.

R-Fe-B sintered magnet

A spectrometry device includes a controller that: causes first irradiated light and second irradiated light to be irradiated from a first light emitter and a second light emitter at mutually different timings; stores information relating to a first light reception signal and information relating to a second light reception signal in a storage at mutually different timings, in synchronization with irradiation timings of the first irradiation light and the second irradiation light; acquires information relating to a first optical spectrum based on the information relating to the first light reception signal stored in the storage during a first time period; and acquires information relating to a second optical spectrum based on the information relating to the second reception signal stored in the storage during a second time period.

Spectrometry device and spectrometry method

An R&#x2014;Fe&#x2014;B base sintered magnet is prepared through the steps of providing an alloy fine powder having a predetermined composition, compression shaping the alloy fine powder in an applied magnetic field into a compact, sintering the compact at a temperature of 900-1,250&#xb0; C. into a sintered body, cooling the sintered body to 400&#xb0; C. or below, high-temperature heat treatment including placing a metal, compound or intermetallic compound containing HR which is Dy, Tb and/or Ho, on the surface of the sintered body, heating at a temperature from more than 950&#xb0; C. to 1,100&#xb0; C., for causing grain boundary diffusion of HR into the sintered body, and cooling to 400&#xb0; C. or below, and low-temperature heat treatment including heating at a temperature of 400-600&#xb0; C. and cooling to 300&#xb0; C. or below. The sintered magnet produces a high coercivity despite a low content of Dy, Tb and Ho.

Method for preparing R&#x2014;Fe&#x2014;B sintered magnet

An R&#x2014;Fe&#x2014;B base sintered magnet is provided comprising a main phase containing an HR rich phase of (R', HR)(Fe,(Co))B wherein R&#x2032; is an element selected from yttrium and rare earth elements exclusive of Dy, Tb and Ho, and essentially contains Nd, and HR is an element selected from Dy, Tb and Ho, and a grain boundary phase containing a (R&#x2032;, HR)&#x2014;Fe(Co)-Mphase in the form of an amorphous phase and/or nanocrystalline phase, the (R&#x2032;, HR)&#x2014;Fe(Co)-Mphase consisting essentially of 25-35 at % of (R&#x2032;, HR), 2-8 at % of Mwhich is at least one element selected from Si, Al, Mn, Ni, Cu, Zn, Ga, Ge, Pd, Ag, Cd, In, Sn, Sb, Pt, Au, Hg, Pb, and Bi, up to 8 at % of Co, and the balance of Fe. The HR rich phase has a higher HR content than the HR content of the main phase at its center. The magnet produces a high coercivity despite a low content of Dy, Tb and Ho.

An R&#x2014;(Fe,Co)&#x2014;B base sintered magnet consisting essentially of 12-17 at % of R containing Nd and Pr, 0.1-3 at % of M(typically Si), 0.05-0.5 at % of M(typically Ti), B, and the balance of Fe, and containing R(Fe,Co)B as a main phase has a coercivity of at least 10 kOe. The magnet contains a Mboride phase at a grain boundary triple junction, and has a core/shell structure that the main phase is covered with a grain boundary phase. The grain boundary phase is composed of an amorphous and/or nanocrystalline R'&#x2014;(Fe,Co)&#x2014;M&#x2032; phase consisting essentially of 25-35 at % of R&#x2032; containing Pr, 2-8 at % of M&#x2032; (typically Si), up to 8 at % of Co, and the balance of Fe. A coverage of the main phase with the R&#x2032;&#x2014;(Fe,Co)&#x2014;M&#x2032; phase is at least 50%, and the bi-granular grain boundary phase has a width of at least 50 nm.

R-(Fe, Co)-B sintered magnet and making method

The invention provides an R&#x2014;Fe&#x2014;B sintered magnet consisting essentially of 12-17 at % of Nd, Pr and R, 0.1-3 at % of M, 0.05-0.5 at % of M, 4.8+2*m to 5.9+2*m at % of B, and the balance of Fe, containing R(Fe,(Co))B intermetallic compound as a main phase, and having a core/shell structure that the main phase is covered with a grain boundary phases. The sintered magnet has an average grain size of less than 6 &#x3bc;m, a crystal orientation of more than 98%, and a degree of magnetization of more than 96%, and exhibits a coercivity of at least 10 kOe despite a low or nil content of Dy, Tb, and Ho.

R-Fe-B sintered magnet and making method

A sheet feeding device includes: a stacker that stacks sheets of paper; a suction conveyor disposed vertically above the sheets stacked in the stacker for sucking and conveying the sheets; a blower that blows air onto the sheets; and a regulating member disposed on a downstream side of the suction conveyor in a conveyance direction, facing an outlet of the sheets of the suction conveyor and projecting vertically upward, wherein the suction conveyor includes: horizontal portions provided on both ends in a width direction; and a recess provided in an intermediate portion and recessed vertically above the horizontal portions, and a lower limit of a projection height of the regulating member is set so that, when there is a vertical gap between a vertical upper end portion of the regulating member and the horizontal portions, a length of the gap is less than twice a thickness of the sheets.

Sheet feeding device and image forming apparatus

The invention provides an R&#x2014;Fe&#x2014;B sintered magnet consisting essentially of 12-17 at % of Nd, Pr and R, 0.1-3 at % of M, 0.05-0.5 at % of M, 4.8+2*m to 5.9+2*m at % of B, and the balance of Fe, containing R(Fe,(Co))B intermetallic compound as a main phase, and having a core/shell structure that the main phase is covered with grain boundary phases. The sintered magnet exhibits a coercivity of at least 10 kOe despite a low or nil content of Dy, Tb and Ho.

R&#x2014;Fe&#x2014;B sintered magnet and making method

A rare earth sintered magnet is an anisotropic sintered body comprising NdFeB crystal phase as primary phase and having the composition RTMSiBwherein Ris a rare earth element inclusive of Sc and Y, T is Fe and/or Co, M is Al, Cu, Zn, In, P, S, Ti, V, Cr, Mn, Ni, Ga, Ge, Zr, Nb, Mo, Pd, Ag, Cd, Sn, Sb, Hf, Ta, or W, 'a' to 'e' are 12&#x2264;a&#x2264;17, 0&#x2264;c&#x2264;10, 0.3&#x2264;d&#x2264;7, 5&#x2264;e&#x2264;10, and the balance of b, wherein Dy and/or Tb is diffused into the sintered body from its surface.

Rare earth sintered magnet and making method

A sintered Nd base magnet segment has a coercive force high at the periphery and lower toward the inside. A method for preparing the magnet includes the steps of: (a) providing a sintered Nd base magnet block having surfaces and a magnetization direction, (b) coating the surfaces of the magnet block excluding the surface perpendicular to the magnetization direction with a Dy or Tb oxide powder, a Dy or Tb fluoride powder, or a Dy or Tb-containing alloy powder, (c) treating the coated block at a high temperature for causing Dy or Tb to diffuse into the block, and (d) cutting the block in a plane perpendicular to the magnetization direction into a magnet segment having a coercive force distribution on the cut section that the coercive force is high at the periphery and lower toward the inside and a constant coercive force distribution in the magnetization direction.

Growing community of inventors

Echizen, Japan

Hajime Nakamura