Abstract: A graphite electrode includes a pole having a socket in an internal screw shape at an end portion, and a nipple in an external screw shape that can be fastened to the socket, wherein a value obtained by subtracting an effective diameter on a small diameter end side of the nipple from an effective diameter on a small diameter end side of the socket is 0.05 to 0.7 mm, and a value obtained by subtracting a taper angle of the socket from a taper angle of the nipple is ?2 minutes to ?3 minutes 30 seconds.

Abstract: Observation fields of an electron microscope image and an optical magnifying observation image are smoothly switched. A magnifying observation apparatus includes: a pair of end-face plates closes end faces of a body portion; an electron beam imaging device mounted on a first position of a cylindrical shaped outer surface of the body portion; an optical imaging device mounted on a second position being different from the first position in the outer surface; a rotating device that rotates the both imaging devices along the outer surface such that a distance from each of the both imaging devices to a common rotation axis of the both imaging devices is kept constant and optical axes of the both imaging devices are oriented toward the rotation axis; a specimen stage that is disposed in the chamber, and arranged to a position that is substantially the same to a height of the rotation axis.

Abstract: Observation fields of an electron microscope image and an optical magnifying observation image are smoothly switched. A magnifying observation apparatus includes: a pair of end-face plates closes end faces of a body portion; an electron beam imaging device mounted on a first position of a cylindrical shaped outer surface of the body portion; an optical imaging device mounted on a second position being different from the first position in the outer surface; a rotating device that rotates the both imaging devices along the outer surface such that a distance from each of the both imaging devices to a common rotation axis of the both imaging devices is kept constant and optical axes of the both imaging devices are oriented toward the rotation axis; a specimen stage that is disposed in the chamber, and arranged to a position that is substantially the same to a height of the rotation axis.

Abstract: A latent electrostatic image developing device. A developer agitating/conveying mechanism is disposed in a development housing and has an agitating/conveying member for conveying a developer, while agitating it, along a developer application. A toner concentration detector is disposed in the bottom wall of the development housing to oppose the agitating/conveying member. The upper surface and the side surface of a detector portion of the toner concentration detector are connected by an arcuate surface or a chamfered surface. The toner concentration detector is fitted into an opening formed in the bottom wall of the development housing, and the upper surface of the detector portion protrudes from the inner surface of the bottom wall of the development housing by an amount nearly corresponding to the radius of the arcuate surface or the height of the chamfer of the chamfered surface.

Abstract: A developer agitating/conveying device having at least one partition wall disposed within a housing with a developer transfer port at the central portion thereof; a first agitating/conveying member disposed along the partition wall on one side of the partition wall for conveying the developer from the opposite end portions toward the central portion thereof, the first agitating/conveying member having a first helical blade and a second helical blade; and a second agitating/conveying member disposed along the partition wall on the other side of the partition wall for conveying the developer from the central portion toward the opposite end portions thereof, the second agitating/conveying member having a first helical blade and a second helical blade.