Abstract: A metal oxide powder except &agr;-alumina, comprising polyhedral particles having at least 6 planes each, a number average particle size of from 0.1 to 300 &mgr;m, and a D90/D10 ratio of 10 or less where D10 and D90 are particle sizes at 10% and 90% accumulation, respectively from the smallest particle size side in a cumulative particle size curve of the particles. This metal oxide powder contains less agglomerated particles, and has a narrow particle size distribution and a uniform particle shape.

Abstract: A flange section presses a tip of one of four elastic arms upon tilting of a controlling unit formed of a stick and the flange section. The pressed elastic arm operates one of individual-switches disposed at four corners of a switch case. Each elastic arm extends from each side of the quadrangular switch case to at least a middle point of a side, which is adjacent and parallel to the arm. Using this structure, a four-directional control switch, which can effectively use a space in an electronic apparatus, can be obtained.

Abstract: The first movable contact including a ring portion and projections extended in same width as the ring is arranged against the peripheral fixed contacts and the central fixed contact at the bottom of the switch case in such manner that the ring portion confronts the peripheral fixed contacts at spaced intervals apart.

Abstract: A flange section presses one of tips of four elastic arms by tilting a controlling unit formed of a stick and the flange section. The pressed elastic arm operates one of individual-switches disposed at four corners of a switch case. Each elastic arm extends from each side of the quadrangular switch case to at least a middle point of a side, which is adjacent and parallel to the arm. Using this structure, a four-directional control switch, which can effectively use a space in an electronic apparatus, can be obtained.

Abstract: In a switch, an elastic member made of elastic material includes a bar section, a conical section at its upper portion functioning as a first deforming section, and a second deforming section at its lower portion. A movable contact in a switch case is pushed with the lower end portion of the second deforming section. A bar section of an elastic element projects through a central hole of a cover fixed to the switch case. In this switch, a pushing force applied to the elastic element deforms the first deforming section elastically, and then the second deforming section deforms elastically, and thus, the switch operates. The switch can absorb fluctuations due to combination of components of an electronic appliance, and stabilize its manipulation feeling through eliminating looseness of an operation button of the appliance.

Abstract: A torque converter provided with a lock-up clutch and including a pump impeller, a turbine runner, a turbine hub, a stator, a clutch piston rotatable with the turbine runner and cooperating with the pump impeller to define an engaging chamber, a front cover cooperating with the clutch piston to define a releasing chamber and a friction member attached to the front cover, and wherein the lock-up clutch is placed in a slipping state for slipping engagement between the clutch piston and the front cover through the friction member, by a controlled difference between pressures of a working fluid in the engaging and releasing chambers, and the pump impeller and the stator cooperate to define of a first and a second fluid passage both of which communicate with the engaging chamber, while the stator and the turbine hub cooperate with each other to define the other of the first and second fluid passages, and wherein the lock-up clutch is brought into the slipping state with a supply flow of the fluid into the engaging

Abstract: A push switch includes a case made of insulating resin including a plate-like portion shaped substantially like a plate, a first fixed contact exposed at a first surface of the plate-like portion of the case, a second fixed contact exposed at the first surface of the plate-like portion of the case, and a movable contact which electrically connects and disconnects the first fixed contact to the second fixed contact. A first metal member including the first fixed contact further includes a first terminal exposed outside the case, and a first middle portion exposed at a second surface of the plate-like portion of the case, the first middle portion connecting the first fixed contact to the first terminal. A second metal member including the second fixed contact further includes a second terminal exposed outside the case, and a second middle portion for connecting the second fixed contact to the second terminal.

Abstract: The first movable contact including a ring portion and projections extended in same width as the ring is arranged against the peripheral fixed contacts and the central fixed contact at the bottom of the switch case in such manner that the ring portion confronts the peripheral fixed contacts at spaced intervals apart.

Abstract: Fixed contacts 11, 12, 13 and 14 are provided on the bottom face 10B of recess 10A in switch housing 10. Two contact-receptors 10C, 10D are disposed at corners so as to confront each other on the bottom face 10B. Outer rim 15B of domed movable contact 15 made of thin metal plate and bowed upwardly is placed on the receptors so that a lower face of top 15A of movable contact 15 faces fixed contacts 11, 12, 13 and 14. Flexible film 16 is fixed so that film 16 covers recess 10A and accommodates domed movable contact 15.

Abstract: A thin push switch used in a portable electronic apparatus includes a less number of components jointed together without any adhesive controlled hardly, and can thus be favored with mass production. The push switch includes an insulating spacer having first cramp-locked tabs cramp-locked with the first terminals of a fixed plate and second cramp-locked tabs cramp-locked with the second terminals of a contact plate. The fixed plate includes a fixed contact, and the contact plate includes a movable contact. Accordingly, the contact plate, the insulating spacer, and the fixed plate can be joined together without an adhesive.

Abstract: In a switch, an elastic member made of elastic material includes a bar section, a conical section at its upper portion functioning as a first deforming section, and a second deforming section at its lower portion. A movable contact in a switch case is pushed with the lower end portion of the second deforming section. A bar section of an elastic element projects through a central hole of a cover fixed to the switch case. In this switch, a pushing force applied to the elastic element deforms the first deforming section elastically, and then the second deforming section deforms elastically, and thus, the switch operates. The switch can absorb fluctuations due to combination of components of an electronic appliance, and stabilize its manipulation feeling through eliminating looseness of an operation button of the appliance.

Abstract: A torque converter provided with a lock-up clutch and including a pump impeller, a turbine runner, a turbine hub, a stator, a clutch piston rotatable with the turbine runner and cooperating with the pump impeller to define an engaging chamber, a front cover cooperating with the clutch piston to define a releasing chamber and a friction member attached to the front cover, and wherein the lock-up clutch is placed in a slipping state for slipping engagement between the clutch piston and the front cover through the friction member, by a controlled difference between pressures of a working fluid in the engaging and releasing chambers, and the pump impeller and the stator cooperate to define of a first and a second fluid passage both of which communicate with the engaging chamber, while the stator and the turbine hub cooperate with each other to define the other of the first and second fluid passages, and wherein the lock-up clutch is brought into the slipping state with a supply flow of the fluid into the engaging

Abstract: Alpha alumina powder having a regulated particle size, a uniform particle shape and a narrow particle size distribution and further a low halogen content is produced by calcining at least one starting material selected from transition alumina and alumina compounds in a halogen-containing atmosphere which comprises a hydrogen halide gas, a halogen gas or a mixture of a halogen gas and steam and contains at least 0.1% by volume of at least one halogen-containing gas selected from the group consisting of hydrogen halide gas and halogen gas, and removing halogen from a calcined material. The produced alpha-alumina powder is excellent in a packing property and homogeneously packed.

Abstract: A process for producing &agr;-alumina containing &agr;-alumina single crystal particles characterized in that at least one of a transition alumina and transition alumina precursor is calcined in an atmosphere containing at least 1% by volume of hydrogen chloride at a temperature of not less than 600° C., preferably from 600 to 1,400° C., and more preferably from 800 to 1,200° C. Aluminum hydroxide, alum, aluminum sulfate, etc. are used as the alumina raw material capable of being converted to transition alumina on heating. &agr;-Alumina comprising octahedral or higher polyhedral &agr;-alumina single crystal particles have a high alumina purity above a given level, are fine and homogeneous, have a narrow particle size distribution, are not agglomerated particles, and can be obtained from raw materials of various kinds, purities, shapes, sizes, and compositions.

Abstract: A push switch used in an electronic apparatus is provided which has a thin switch case in spite of fixed contacts embedded in the bottom of the case. When the push switch is depressed, a center fixed contact and an outer fixed contact both made of metal strip and embedded in the bottom of the switch case is electrically connected and disconnected to each other by a movable contact. In the fixed contacts, embedded thin portions are formed, which is thinner than that of the metal strip as the material. As the thin portions are embedded in the switch case, the overall thickness of the bottom of the case is reduced, thus contributing to the thinner push switch.

Abstract: A photomask of this invention includes a main pattern part for forming a main pattern in a resist film and an alignment mark part for forming, in the resist film, an alignment accuracy determining mark not penetrating the resist film in section after development of the resist film.

Abstract: A thin push switch used in a portable electronic apparatus includes a less number of components jointed together without any adhesive controlled hardly, and can thus be favored with mass production. The push switch includes an insulating spacer having first cramp-locked tabs cramp-locked with the first terminals of a fixed plate and second cramp-locked tabs cramp-locked with the second terminals of a contact plate. The fixed plate includes a fixed contact, and the contact plate includes a movable contact. Accordingly, the contact plate, the insulating spacer, and the fixed plate can be joined together without an adhesive.

Abstract: A push-on switch includes an insulating resin case 21 which contains a main body 24, a central fixed contact point 22 and an outer fixed contact point 23 fixed on the back wall of a front-open recess 21A; a domed movable contact 27; and an operating body 29 supported by a cover 30. The case 21 has an overhang 25, which stretches horizontally from the case in the upper part to be of a size greater than the size of main body 24. The overhang 25 is provided with terminals 26 electrically coupled with the central fixed contact point 22 and the outer fixed contact point 23, respectively. In the above-configured switch, the constituent parts are simplyformed, and can be manufactured through easy mold machining or other processing methods.

Abstract: A translucent alumina sintered body wherein the total content of an alkali metal element and an alkaline earth metal element is 50 ppm or less, and the linear transmittance of a light having a wavelength of 600 nm is 40% or more at a thickness of the sintered body of 0.85 mm.

Abstract: A lithography pattern data generation method of this invention includes steps of dividing a predetermined area where said plural design data are arranged, which corresponds to an area where design patterns are to be formed, into plural partial exposure areas each in the shape of a stripe with a width corresponding to a deflection width of an exposure beam; extracting, from the plural design data, design data each falling within any of the plural partial exposure areas as a first design data group and extracting design data each extending over two or more of the plural partial exposure areas as a second design data group; generating first lithography pattern data of each of the plural partial exposure areas from the design data belonging to the first design data group; and generating second lithography pattern data of each of the plural partial exposure areas from the design data belonging to the second design data group.