Abstract: An imaging filter disposed on a front surface of an image sensor and serving to limit an incident angle of light on the image sensor is provided. The filter includes: a transparent substrate; a first shielding film provided on the front surface of the substrate and having a plurality of incidence openings, the incidence openings having a constant size and provided at an interval; a second shielding film provided on a back surface of the substrate and having a plurality of emission openings, the emission openings having a constant size and having centers which are coincident with the incidence openings; and a reflecting film provided on at least one of the front surface and the back surface of the substrate and including a multilayer dielectric film that transmits light having a wavelength and being incident almost vertically on the reflecting film and that that reflects the light having the wavelength and being incident obliquely on the reflecting film.

Abstract: A lens-laminated composite optical element composed of a vitreous optical element having a plane surface to perform inherent optical functions, and a thin and filmy transparent plastic lens portion molded in a curved lens profile and laminated on the plane surface of the vitreous optical element by the use of a mold.

Abstract: For manufacturing an optical element having a plural number of different optical multi-layer coatings deposited on a surface of a substrate plate, a peeling metal film is deposited on a large substrative base material which is divided into a plural number of subsections, a pattern of an optical multi-layer coating is transferred to each one of the subsections of the substrative base material by the use of a mask member, followed by etching of the peeling metal film, deposition of optical multi-layer coatings on the substrative base material, and removal of the peeling metal film. The substrative base material is processed through a similar deposition stage repeatedly until a required number of optical multi-layer coatings are deposited in each subsection. In a final stage, the substrative base material is cut to separate the individual subsections which will make the units of optical elements of ultimate products.

Abstract: A lens-laminated composite optical element composed of a vitreous optical element having a plane surface to perform inherent optical functions, and a thin and filmy transparent plastic lens portion molded in a curved lens profile and laminated on the plane surface of the vitreous optical element by the use of a mold.

Abstract: A valve gear comprises a valve 1 having a valve element and a valve stem, and an actuator having a driving shaft for operating the valve element of the valve. A connecting portion 7 is provided on either the valve or the actuator. A sleeve having a smooth inner surface is fixedly or rotatably fitted in a bore formed in the connecting portion 7 so as to slidably receive the valve stem and the driving shaft and slidably contact the inner smooth surface of the sleeve with outer surfaces of the valve stem and the driving shaft. The valve stem and the driving shaft inserted into the sleeve through the opposite ends, of the sleeve are provided at their end portions with respective coupling portions, so that the stem and the shaft are able to engage with each other only at the particular one point of relative rotation of the stem and the shaft.

Abstract: A piping branch structure includes a branch pipe distributing an inflowing fluid to pipes in at least three directions, and one of the pipes face a direction of flow of the fluid, wherein a fluid inlet of one of the pipes protrudes into the branch pipe. By protruding a fluid inlet of a pipe which faces a direction of flow of the fluid into the branch pipe, the protruding pipe act as obstacles, thus no vortex is generated and the non-vortex flow state can be maintain. In case of piping of recirculating system of a reactor, an inner pipe, whose structure is integral with that of a riser pipe, is provided so that the inner pipe extends toward a master tube side in a cross branch pipe. The inner pipe is provided holes and a flow-regulating plate. The quantity of cooling water circulating through the core of the reactor and the flow state of the cooling water in the pressure vessel are stabilized and balanced.

Abstract: A nuclear reactor is equipped with a cooling water circulation system which includes a water-feed conduit and a drain conduit to circulate the cooling water to and from a pressure vessel which surrounds a reactor core, the cooling water having a free liquid level maintained above the reactor core. The drain conduit is inserted in the pressure vessel from the upper side toward the lower side relative to the free liquid level. A double tube consisting of an inner tube and an outer tube maintaining a gap therebetween is formed in the end portion of the drain conduit. The inner tube and outer tube being continuous with the drain conduit, the opening at the lower end of the inner tube is located below said free liquid level but above the reactor core. The opening at the upper end of the outer tube is located above the free liquid level. The opening at the lower end of said outer tube is located below the reactor core.