Ngk Insulators, Inc.

Hisanori Yamamoto

Tsutomu Nanataki

Yukihisa Takeuchi

Katsuyuki Takeuchi

Takahiro Maeda

Takashi Oguchi

Koji Kimura

Tsuneaki Ohashi

Keiichiro Watanabe

Natsumi Shimogawa

Sugio Miyazawa

A translucent polycrystalline sintered body is mainly composed of an alumina, is suitable for the manufacture of an arc tube for a high-intensity discharge lamp, and has an average grain diameter of 35 to 70 &#x3bc;m, preferably 50 to 60 &#x3bc;m. In a case where the sintered body is in a 0.5-mm-thick flat plate shape, the in-line transmittance of the sintered body is 30% or more, preferably 50% or more. In this case, the ratio between maximum and minimum in-line transmittance values is 2:1 to 1:1 in the visible region of 360 to 830 nm. The bending strength of the sintered body is 250 MPa or more, preferably 300 MPa or more.

Translucent polycrystalline sintered body, method for producing the same, and arc tube for high-intensity discharge lamp

An actuator element has a plate member, a piezoelectric/electrostrictive body disposed in facing relation to the plate member, and a beam disposed between the plate member and the piezoelectric/electrostrictive body and fixing the piezoelectric/electrostrictive body to the plate member. The piezoelectric/electrostrictive body has a piezoelectric/electrostrictive layer, an upper electrode formed on a surface of the piezoelectric/electrostrictive layer which faces the plate member, and a lower electrode formed on a surface of the piezoelectric/electrostrictive layer which is opposite to the surface thereof facing the plate member. When an electric field is applied to the upper electrode and the lower electrode, a portion of the piezoelectric/electrostrictive body is displaced toward or away from the plate member.

Actuator element and device including the actuator element

Provided are a method for producing ceramic green sheets used for making a ceramic substrate which is reduced in cracking failure and improved in adhesion between laminated layers and is high in lamination property, high in strength and excellent in surface roughness, said method including heat-treating the ceramic powder having a specific particle size by dry grinding a ceramic powder to prepare ceramic powder having a specific average degree of aggregation and preparing a slurry using the ceramic powder so that a green density of the resulting ceramic green sheets is in a desired range, and a method for making a ceramic laminated substrate having excellent various properties by laminating the above ceramic green sheets and firing the laminate.

Method for producing ceramic green sheet

A ceramic member has a flat or curved ceramic plate having a plurality of minute through holes of a maximum pore diameter of 150 .mu.m or less, and having electrodes installed on one surface of the plate. The ceramic member controls the ejection of ions carrying either positive or negative charge from the minute through holes by switching the sign of charge carried by the electrodes. The minute through holes are tapered toward the side where ions are ejected. The ceramic member gives an improved property of ejecting charged particle from minute through holes while maintaining high mechanical strength and productivity.

Ceramic member with an electrode and a plurality of tapered through

A method of controlling the amount of firing shrinkage of a ceramic green body prepared by molding a ceramic powder (A) to a desired value A.sub.1 by heat treating the powder at a temperature T.sub.1 that provides the firing shrinkage A.sub.1 at a predetermined firing temperature. The temperature T.sub.1 is determined based on an established correlation between an amount of firing shrinkage at the predetermined firing temperature and a heat-treatment temperature of a powder (B) having a composition similar to that of the powder (A) in such an extent that a total amount of a greatest common content of an individual component common between the powders (A) and (B) in terms of percent is 90% by weight or more, and satisfying such a relation that the spherical diameter of powder (A) is within a range of .+-. 30% relative to the spherical diameter (Rs) of the powder (B) and that its average degree of aggregation (x) is within the range from 1/2 fold to 2 fold relative to the average degree of aggregation (x) of the powder (B).

Method for controlling firing shrinkage of ceramic green body

Disclosed is a display device comprising an optical waveguide plate for introducing light thereinto, and a driving section provided opposingly to the back surface of the optical waveguide plate and including a number of actuator elements arranged corresponding to a large number of picture elements, for displaying, on the optical waveguide plate, a picture image corresponding to an image signal by controlling leakage light at a predetermined portion of the optical waveguide plate by controlling displacement action of each of the actuator elements in a direction to make contact or separation with respect to the optical waveguide plate in accordance with an attribute of the image signal to be inputted; the display device further comprising a displacement-transmitting section for transmitting the displacement action of the actuator element to the optical waveguide plate, wherein a plate member of the displacement-transmitting section is constructed by a white scattering element, and a color filter is formed at a position corresponding to each of the actuator elements, on the back surface of the optical waveguide plate.

Display device having a colored layer disposed between a displacement

A method of manufacturing a ceramic member composed of a thin plate having a plurality of fine through holes and a rigid plate integrally formed with the thin plate by firing. The thin plate is supported by the rigid plate at least at both sides of a portion where the plurality of fine through holes are formed. A minimum value of the size of the holes is 150 .mu.m or less, a thickness of the thin plate 7 is 100 .mu.m or less, and a minimum value of the interval between adjacent holes is 150 .mu.m or less. A tensile strength .sigma. of a green sheet for the thin plate is 10 kgf/cm.sup.2 or more and 200 kgf/cm.sup.2 or less. An elongation factor represented by the expression .DELTA.I.multidot.S/T, where .DELTA.I represents an amount (mm) of elongation at rupture; T, a tension (kgf) at rupture; and S, a cross section (mm.sup.2) of the green sheet for the thin plate, is 0.5 mm.sup.3 /kgf or more and 25.0 mm.sup.3 /kgf or less. An absolute value of the difference of pre-sintering temperature T.sub.50 between the green sheet for the thin plate and the green sheet for the rigid plate is 50.degree. C. or less, and an absolute value of the difference of firing shrinkage factor F therebetween is 1.5% or less. The green sheet for the thin plate having the plurality of fine through holes 1 formed by punching thereupon is laminated upon the rigid plate to form an integral laminate, and then fired.

Method of manufacturing ceramic member

A ceramic green sheet includes ceramic particles having a spherical diameter of 0.01-0.5 .mu.m of a primary particle as a ceramic component, an average degree of aggregation of 10 or less, wherein the ceramic green sheet contains at most 1 vol % of secondary particles having a diameter of 20 .mu.m or more and has a surface roughness (Ra) of 0.2 .mu.m or less. A method for producing a ceramic substrate having a thickness of 30 .mu.m or less includes the steps of: preparing a ceramic slurry by mixing a ceramic powder with an organic binder and at least one organic solvent, and adjusting a viscosity to be within the range of 100-10,000 mPa.s; removing coarse aggregated particles from the ceramic slurry; molding the ceramic slurry into a ceramic green sheet by a reverse roll coater method; and firing the ceramic green sheet so that an average crystal grain size be 2 .mu.m or less.

Zirconia ceramic green sheet

A ceramic member includes a thin plate having a plurality of minute throughholes and a rigid plate supporting the thin plate. The area of the thin plate both ends of which are supported by the rigid plate has a part bent toward the rigid plate so that the line connecting the apexes of the bent part is a straight line, and minute throughholes are formed in the vicinity of the apexes of the bent part. Good adhesion between minute throughholes formed on the line connecting the apexes of the bent part and the drum and the like is obtained, and defective transfer can be prevented.

Ceramic member

A method for producing a ceramic member having fine throughholes, includes the steps of: producing a first green sheet for a thin ceramic plate; forming a plurality of fine throughholes having a minimum diameter of 150 .mu.m or less after firing in the first green sheet and having a minimum distance of 150 .mu.m or less between two of the throughholes after firing, the throughholes being disposed zigzag; producing a second green sheet to be used for a ceramic substrate; forming at least one window portion in the second green sheet; laminating the first green sheet on the second green sheet for obtaining a unitary laminate so that the plurality of fine throughholes in the first green sheet match the window portion(s) of the second green sheet; and firing the laminate so as to obtain a unitary sintered body; wherein a shorter side (maximum width) W of the window portion of the ceramic substrate satisfies the formula: W(mm).gtoreq.0.01/d, wherein d is the minimum distance between two of the throughholes after firing. Alternatively, the throughholes can be formed in the first green sheet after it is laminated with the second green sheet.

Method for producing a ceramic member having fine throughholes

The present invention provides a method for controlling a firing shrinkage of a ceramic green body. The method includes the steps of: subjecting a ceramic powder to a pretreatment by which a spherical diameter (Rs) of the ceramic powder is adjusted to be 1 .mu.m or less, wherein Rs is expressed by an equation of Rs(.mu.m)=6/.rho. S (.rho. is a true density (g/cm.sup.3) of the ceramic powder, and S is a BET specific surface area (m.sup.2 /s) of the ceramic powder.); subjecting the ceramic powder to heat treatment at a specific temperature calculated in advance; molding the ceramic powder to obtain a ceramic green body; and firing the ceramic green body. A temperature for the heat-treatment is calculated of the basis of a correlation between calculative rates for firing and arbitrary selected temperatures.

A ceramic green sheet includes ceramic particles having a spherical diameter of 0.01-0.5 .mu.m of a primary particle as a ceramic component, an average degree of aggregation of 10 or less, wherein the ceramic green sheet contains at most 1 vol % of secondary particles having a diameter of 20 .mu.m or more and has a surface roughness (Ra) of 0.2 .mu.m or less. A method for producing a ceramic substrate having a thickness of 30 .mu.m or less includes the steps of: preparing a ceramic slurry by mixing a ceramic powder with an organic binder and at least one organic solvent, and adjusting a viscosity to be within the range of 100-10,000 mPa's; removing coarse aggregated particles from the ceramic slurry; molding the ceramic slurry into a ceramic green sheet by a reverse roll coater method; and firing the ceramic green sheet so that an average crystal grain size be 2 .mu.m or less.

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Nagoya, Japan

Hisanori Yamamoto