Abstract: Provided is a power conversion device capable of suppressing common-mode voltage fluctuation resulting from output voltage transitioning. A power conversion device 1 is provided with N voltage control units 21 to 2N, a full-bridge conversion unit having four switches QB1 to QB4, a clamp unit having holding switches QC1 and QC2, and a control unit 5. The control unit controls the four switches QB1 to QB4, the holding switches QC1 and QC2, the pairs of regenerative switches Q11 to Q1N and Q21 to Q2N and pairs of input switches Q31 to Q3N and Q41 to Q4N of each of the N voltage control units 21 to 2N. As a result, the control unit can switch an output voltage V1 between 2N+3 levels.

Abstract: Provided is a power conversion device capable of suppressing common-mode voltage fluctuation resulting from output voltage transitioning. A power conversion device 1 is provided with N voltage control units 21 to 2N, a full-bridge conversion unit having four switches QB1 to QB4, a clamp unit having holding switches QC1 and QC2, and a control unit 5. The control unit controls the four switches QB1 to QB4, the holding switches QC1 and QC2, the pairs of regenerative switches Q11 to Q1N and Q21 to Q2N and pairs of input switches Q31 to Q3N and Q41 to Q4N of each of the N voltage control units 21 to 2N. As a result, the control unit can switch an output voltage V1 between 2N+3 levels.

Abstract: An object of the invention is to provide, in porous thermal insulating firebricks formed by molding and drying bubble-containing slurry obtained by foaming slurry containing a fire resistant powder and water, a thermal insulating firebrick superior in thermal insulating property in spite of the same composition and porosity. A porous thermal insulating firebrick formed by molding and drying bubble-containing slurry obtained by foaming slurry containing a fire resistant powder with a heat resistant temperature of 1,000° C. or higher and water has the porosity of 60% or more, and 80% or more volume with respect to a total pore volume of the inside of the thermal insulating firebrick consists of pores having a pore size of 200 ?m or less.

Abstract: An object of the invention is to provide, in porous thermal insulating firebricks formed by molding and drying bubble-containing slurry obtained by foaming slurry containing a fire resistant powder and water, a thermal insulating firebrick superior in thermal insulating property in spite of the same composition and porosity. A porous thermal insulating firebrick formed by molding and drying bubble-containing slurry obtained by foaming slurry containing a fire resistant powder with a heat resistant temperature of 1,000° C. or higher and water has the porosity of 60% or more, and 80% or more volume with respect to a total pore volume of the inside of the thermal insulating firebrick consists of pores having a pore size of 200 ?m or less.

Abstract: An electrophotographic photoreceptor for incorporation in a process cartridge and removably mounted in the main body of an electrophotographic device. The photoreceptor includes a photosensitive drum having a cylindrical conductive substrate and a photosensitive layer formed on the substrate's outer peripheral surface. The photoreceptor has a gear flange engaged with an open end of the drum, for transmitting rotational driving force from the main body to the drum. A driving force transmitting section, designed to achieve rotational accuracy and rotational strength and realize reduced production costs, includes at least two projected portions inclined in a direction substantially opposite to the rotational direction of the drum, and arranged concentrically about the central axis of the drum. The driving force transmitting section also includes a raised portion, formed on a rotational driving force receiving surface of the gear flange, which reinforces an area between the projected portions.

Abstract: An electrophotographic photosensitive member is formed of a photosensitive drum, and a cylindrical resin member having a metallic spring therein. The cylindrical resin member is situated inside the photosensitive drum to provide a pressure to an inner surface of the drum. The electrophotographic photosensitive member has a charging-sound absorption capability, wherein the cylindrical resin member is not adversely affected when it is left in an adverse environment.