Tdk Corporation

Mitsubishi Denki Kabushiki Kaisha

Oki Electric Industry Co., Ltd.

Magx Co., Ltd.

Noboru Ito

Yoshihiko Minachi

Takeharu Oshima

Taku Murase

Yuuki Aburakawa

Junichi Nagaoka

Shunsuke Kurasawa

Takeshi Masuda

Naoki Mori

Yoshinori Fujikawa

Hidenobu Umeda

Satoko Ueda

Kenya Takagawa

Shigeki Yanagida

A sintered ferrite magnet having a ferrite phase with a hexagonal structure as the main phase, wherein the composition of the metal elements composing the main phase is represented by the following general formula (1):RCaA(FeM): &#x2003;&#x2003;(1),x, m, y and z in formula (1) satisfying all of the conditions represented by the following formulas (2)-(6):0.2&#x2266;&#x2266;0.5: &#x2003;&#x2003;(2)0.13&#x2266;&#x2266;0.41: &#x2003;&#x2003;(3)0.70.15: &#x2003;&#x2003;(4)0.18&#x2266;&#x2266;0.31: &#x2003;&#x2003;(5)9.6&#x2266;12&#x2266;11.8: &#x2003;&#x2003;(6),and wherein the density of the sintered ferrite magnet is at least 5.05 g/cm, and the crystal grains of the sintered ferrite magnet satisfy all of the conditions represented by the following formulas (7) and (8), where L &#x3bc;m is the average for the maximum value and S &#x3bc;m is the average for the minimum value among the diameters passing through the center of gravity of each grains in the crystal cross-section parallel to the c-axis direction of hexagonal structures.&#x2266;0.95: &#x2003;&#x2003;(7)1.8&#x2266;&#x2266;2.5: &#x2003;&#x2003;(8).

Ferrite sintered magnet

The present invention provides a ferrite magnetic material capable of attaining such magnetic properties that Br+(&#x2153;)HcJ is 6200 or more even by sintering at a temperature of 1150&#xb0; C. or lower. The ferrite magnetic material includes as a main phase thereof a ferrite phase having a hexagonal structure, the main phase being represented by the following composition formula (1): LaCa&#x3b1;(FeCo)with &#x3b1; representing one or two of Ba and Sr; wherein the constituent ratios of the metal elements constituting the main phase satisfy the following conditions: x and m are the values in a region bounded by the points, A: (0.53, 0.27), B: (0.64, 0.27), C: (0.64, 0.35), D: (0.53, 0.45), E: (0.47, 0.45) and F: (0.47, 0.32) in the (x, m) coordinates shown in FIG.; 1.3&#x2266;x/yz&#x2266;1.8; and 9.5&#x2266;12z&#x2266;11.0.

Ferrite magnetic material

A ferrite magnet powder is represented by the composition formula AFeMFeO, wherein A represents at least one element selected from the group consisting of Sr, Ba, and Pb; and M represents at least one element selected from the group consisting of Zn, Co, Mn, and Ni, and wherein 0.05&#x2266;x&#x2266;0.80, 1.5&#x2266;a&#x2266;2.2, and 12&#x2266;b&#x2266;17. A high saturation magnetization 4&#x3c0;Is can be achieved by the partial substitution of the Fesite of a W-type ferrite with an element M such as Zn within a certain range.

Ferrite magnet powder, sintered magnet, bond magnet, and magnetic recording medium

W-type ferrite has improved magnetic properties, in particular, coercive force. A high coercive force (HcJ) and a high residual magnetic flux density (Br) can be simultaneously attained by a ferrite magnetic material comprising an oxide having a composition wherein metal elements Sr, Ba and Fe in total have a composition ratio represented by the formula SrBaFeFein which 0.03 &#x2266;x&#x2266;0.80, 1.1&#x2266;a&#x2266;2.4, and 12.3&#x2266;b&#x2266;16.1. The ferrite magnetic material can form any of a ferrite sintered magnet, a ferrite magnet powder, a bonded magnet as a ferrite magnet powder dispersed in a resin, and a magnetic recording medium as a film-type magnetic phase. As for the ferrite sintered magnet, there can be attained a fine sintered structure that has a mean grain size of 0.6 &#x3bc;m or less.

Ferrite magnetic material and ferrite sintered magnet

A ferrite magnetic material comprising a main phase of W-type is provided which has magnetic properties improved through the optimization of additives. The ferrite magnetic material comprises a main constituent having a compound represented by composition formula AFeFeO(wherein A comprises at least one element selected from Sr, Ba and Pb; 1.5&#x2266;a&#x2266;2.1; and 12.9&#x2266;b&#x2266;16.3), a first additive containing a Ca constituent (0.3 to 3.0 wt % in terms of CaCO) and/or a Si constituent (0.2 to 1.4 wt % in terms of SiO), and a second additive containing at least one of an Al constituent (0.01 to 1.5 wt % in terms of AlO), a W constituent (0.01 to 0.6 wt % in terms of WO), a Ce constituent (0.001 to 0.6 wt % in terms of CeO), a Mo constituent (0.001 to 0.16 wt % in terms of MoO), and a Ga constituent (0.001 to 15 wt % in terms of GaO).

In a reflecting-mirror supporting mechanism, elastic rotation about the lateral X axis is made possible by providing first spring elementsand second spring elementsin a bipod. In addition, elastic rotation about the lateral Y axis is made possible by a spring member, and elastically translational displacement along the axial Z axis is made possible by a parallel-spring member. The two legs of the bipodare arranged with their upper ends getting close to each other with a predetermined distance at a tilt with respect to the axial Z axis. Variations in moment load generated in the reflecting mirror can be suppressed by making the intersecting point of the center axes of the two legs of the bipodagree with the position of the center of gravity of the reflecting mirror.

Reflecting mirror supporting mechanism

In a reflecting mirror, a plurality of segmented mirrors are grouped into a plurality of groups of a cluster, and are supported by a plurality of sub mirror cells. The plurality of sub mirror cells are supported by a mirror cell, and all the segmented mirrors are supported by the mirror cell. A reference cell is supported by a plurality of force support mechanisms disposed in the mirror cell with the reference cell being nearly in a weightlessness state. Projections and depressions are prevented from occurring in an axial direction of the reflecting mirror due to a self weight deformation, and the reference cell can be used as a reference surface for control of the positions of the plurality of segmented mirrors and those of the plurality of cluster mirrors in the axial direction of the reflecting mirror.

Reflector device

A fluid pressure support mechanism has a container in which fluid pressure is applied and fluid tubes are connected to the fluid pressure support mechanisms and to a fluid pressure control unit in such a way as to make all the fluid pressure support mechanisms communicate with each other, then a fluid pressure control unit applies the fluid pressure to the containers in the respective fluid pressure support mechanisms via the fluid tubes and controls the fluid pressure, and an electrically attractive actuator translates a mirror in an axial direction with one degree of freedom for translation by attracting force produced by a driven member and an electromagnet.

Mirror support mechanism and optical apparatus using the same

Extrusion-molded magnetic body comprising samarium-iron-nitrogen system magnetic particles

A data communication system between a plurality of data terminals comprises of a terminal apparatus to which a plurality of data terminals are coupled in a star structure through pair lines. The terminal apparatus has a plurality of cable driver circuits and a plurality of cable receiver circuits each coupled with a related data terminal through said pair lines, and outputs of cable receivers and inputs of cable drivers are coupled commonly to a single common line. Thus, data from a data terminal is transmitted to another data terminal through a terminal apparatus. A communication control apparatus is installed close to a data terminal. The communication control apparatus has a data terminal transmit data only when other terminals do not transmit data in order to prevent collision of data in the terminal apparatus. The use of pair lines between data terminals and the common terminal apparatus, the simple structure of the terminal apparatus which has only cable drivers and cable receivers coupled together, and a collision control performed in a communication control apparatus which is positioned close to a data terminal are features of the present invention.

Growing community of inventors

Tokyo, Japan

Noboru Ito