Abstract: An image forming apparatus, wherein the packing density at a closest point where the first peripheral surface and the second peripheral surface are the closest to each other is within a range from 0.3 to 0.4; wherein a maximum magnetic flux density of a principal magnetic pole for generating the magnetic field for development is located in an upstream side from the closest point with respect to the specified direction and at a point where the packing density is equal to or greater than 0.2; and wherein a magnetic flux density of the principal magnetic pole at a point where the packing density is 0.2 in a downstream side from the closest point with respect to the specified direction is equal to or less than ½ of a magnetic flux density of the principal magnetic pole at a point where the packing density is 0.2 in the upstream side.

Abstract: A two-component developing device using a developer containing toner and magnetic carrier particles. The developing device comprises a housing, a developing roller, a magnetic field generator mounted inside the developing roller, and a developer restricting member, and further comprises a developer guide member providing a developer guide path for guiding the developer to the developer amount restricting clearance, providing a developer circulation path for circulating the developer to an upstream end of the guide member, and providing a communication path for bringing the developer guide path into communication with the developer circulation path, an upstream end of the guide member being positioned above the position of a peak of magnetic flux density of the magnetic pole of the magnetic field generator which is closest to a low-magnetic force area downstream of the low-magnetic force area or positioned upstream of such a position and downstream of the low-magnetic force area.

Abstract: The present invention provides a ferrite magnetic material capable of attaining such magnetic properties that Br+(?)HcJ is 6200 or more even by sintering at a temperature of 1150° 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): LaxCam?1?x?m(Fe12?yCoy)z with ? 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. 2; 1.3?x/yz?1.8; and 9.5?12z?11.0.

Abstract: A ferrite magnet powder is represented by the composition formula AFe2+a(1-x)MaxFe3+bO27, 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?x?0.80, 1.5?a?2.2, and 12?b?17. A high saturation magnetization 4?Is can be achieved by the partial substitution of the Fe2+ site of a W-type ferrite with an element M such as Zn within a certain range.

Abstract: A pressure compensated electromagnetic proportional directional flow control valve of the present invention integrally includes: an electromagnetic proportional directional flow control valve configured to be driven by a solenoid; and a pressure compensated valve configured to carry out pressure compensation of a flow rate controlled by the electromagnetic proportional directional flow control valve. A pressure compensation spool moves so as to balance forces of a spring, a first pressure chamber, and a second pressure chamber. With this, the pressure compensation for maintaining a constant pressure difference between an upstream side and a downstream side of a first variable aperture can be carried out, and a surplus liquid of a liquid flowing from a liquid-pressure supply port to a derivation port can flow out from a branch port to outside.

Abstract: 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 Sr(1?x)BaxFe2+aFe3+b in which 0.03 ?x?0.80, 1.1?a?2.4, and 12.3?b?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 ?m or less.

Abstract: 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): RxCamA1?x?m(Fe12?yMy)z: ??(1), x, m, y and z in formula (1) satisfying all of the conditions represented by the following formulas (2)-(6): 0.2?x?0.5: ??(2) 0.13?m?0.41: ??(3) 0.7x?m?0.15: ??(4) 0.18?yz?0.31: ??(5) 9.6?12z?11.8: ??(6), and wherein the density of the sintered ferrite magnet is at least 5.05 g/cm3, and the crystal grains of the sintered ferrite magnet satisfy all of the conditions represented by the following formulas (7) and (8), where L ?m is the average for the maximum value and S ?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. L?0.95: ??(7) 1.8?L/S?2.

Abstract: A holding control valve of the present invention is configured such that: a spool is configured to perform strokes by a piston configured to operate by introduction of pilot pressure and have a larger diameter than the spool; the piston is divided into a pilot piston configured to receive the pilot pressure and a relief operation piston disposed adjacent to the spool to receive pressure of relief oil discharged when a relief valve operates; and the relief oil is introduced to between the pilot piston and the relief operation piston.

Abstract: A hybrid developing carrier, comprising a resin layer formed on an outermost surface, wherein the surface of said resin layer is provided with sites formed of an inorganic compound having basic points or acidic points and sites where the resin forming the resin layer is exposed, a hybrid developing device equipped with the hybrid developing carrier, and an image-forming apparatus equipped with the hybrid developing device.

Abstract: 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 AFe2+aFe3+bO27 (wherein A comprises at least one element selected from Sr, Ba and Pb; 1.5?a?2.1; and 12.9?b?16.3), a first additive containing a Ca constituent (0.3 to 3.0 wt % in terms of CaCO3) and/or a Si constituent (0.2 to 1.4 wt % in terms of SiO2), and a second additive containing at least one of an Al constituent (0.01 to 1.5 wt % in terms of Al2O3), a W constituent (0.01 to 0.6 wt % in terms of WO3), a Ce constituent (0.001 to 0.6 wt % in terms of CeO2), a Mo constituent (0.001 to 0.16 wt % in terms of MoO3), and a Ga constituent (0.001 to 15 wt % in terms of Ga2O3).

Abstract: In a reflecting-mirror supporting mechanism, elastic rotation about the lateral X axis is made possible by providing first spring elements 2 and second spring elements 3 in a bipod 1. In addition, elastic rotation about the lateral Y axis is made possible by a spring member 6, and elastically translational displacement along the axial Z axis is made possible by a parallel-spring member 9. The two legs of the bipod 1 are 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 bipod 1 agree with the position of the center of gravity of the reflecting mirror.

Abstract: 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 Sr(1?x)BaxFe2+aFe3+b in which 0.03?x?0.80, 1.1?a?2.4, and 12.3?b?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 ?m or less.

Abstract: The present invention provides a ferrite magnetic material capable of attaining such magnetic properties that Br+(?)HcJ is 6200 or more even by sintering at a temperature of 1150° 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): LaxCam?1?x?m(Fe12?yCoy)z with ? 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. 2; 1.3?x/yz?1.8; and 9.5?12z?11.0.

Abstract: 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.

Abstract: 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 AFe2+aFe3+bO27 (wherein A comprises at least one element selected from Sr, Ba and Pb; 1.5?a?2.1; and 12.9?b?16.3), a first additive containing a Ca constituent (0.3 to 3.0 wt % in terms of CaCO3) and/or a Si constituent (0.2 to 1.4 wt % in terms of SiO2), and a second additive containing at least one of an Al constituent (0.01 to 1.5 wt % in terms of Al2O3), a W constituent (0.01 to 0.6 wt % in terms of WO3), a Ce constituent (0.001 to 0.6 wt % in terms of CeO2), a Mo constituent (0.001 to 0.16 wt % in terms of MoO3), and a Ga constituent (0.001 to 15 wt % in terms of Ga2O3).

Abstract: In a reflecting-mirror supporting mechanism, elastic rotation about the lateral X axis is made possible by providing first spring elements 2 and second spring elements 3 in a bipod 1. In addition, elastic rotation about the lateral Y axis is made possible by a spring member 6, and elastically translational displacement along the axial Z axis is made possible by a parallel-spring member 9. The two legs of the bipod 1 are 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 bipod 1 agree with the position of the center of gravity of the reflecting mirror.

Abstract: The present invention provides a ferrite magnetic material comprising as a main constituent a compound represented by a composition formula, AFe2+aFe3+bO27 (wherein 1.1?a?2.4, 12.3?b?16.1; and A comprises at least one element selected from Sr, Ba and Pb), and also comprising as additives a Ca constituent in terms of CaCO3 and a Si constituent in terms of SiO2 so as to satisfy the relation CaCO3/SiO2=0.5 to 1.38 (molar ratio). By making the relation CaCO3/SiO2=0.5 to 1.38 (molar ratio) be satisfied, the coercive force (HcJ) and the residual magnetic flux density (Br) can be made to simultaneously attain high levels.

Abstract: 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.

Abstract: 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.

Abstract: A ferrite magnet powder is represented by the composition formula AFe2+a(1-x)MaxFe3+bO27, 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?x?0.80, 1.5?a?2.2, and 12?b?17. A high saturation magnetization 4?Is can be achieved by the partial substitution of the Fe2+ site of a W-type ferrite with an element M such as Zn within a certain range.