Abstract: An exciting coil is constructed by winding a winding in a groove formed on the outer circumference of a circular ring member, and a detecting coil in the shape of a polygon (such as a triangle and a pentagon) when seen from the front is positioned. One side of the detecting coil is placed in a diameter direction of the exciting coil, inside the exciting coil, and the vertex opposite to the one side is placed apart from the exciting coil so that the detecting coil is orthogonal to the exciting coil. A side surface of the exciting coil on the side opposite to the vertex is placed to face the surface of a test material, and used as a flaw detection surface.

Abstract: An exciting coil is constructed by winding a winding in a groove formed on the outer circumference of a circular ring member, and a detecting coil in the shape of a polygon (such as a triangle and a pentagon) when seen from the front is positioned. One side of the detecting coil is placed in a diameter direction of the exciting coil, inside the exciting coil, and the vertex opposite to the one side is placed apart from the exciting coil so that the detecting coil is orthogonal to the exciting coil. A side surface of the exciting coil on the side opposite to the vertex is placed to face the surface of a test material, and used as a flaw detection surface.

Abstract: Colored magnetic particles for magnetophoretic display capable of substantially preventing peeling of a pigment therefrom, to thereby prevent contamination of a dispersion medium during use of a magnetophoretic display panel, and a method for manufacturing the same. The colored magnetic particles include magnetic particle elements and a coloring layer formed on each of the magnetic particle elements from a first dispersion liquid using a coating apparatus of a tumbling, fluidizing and granulating type, to thereby color each of the magnetic particles. The first dispersion liquid is constituted of a coloring pigment, synthetic resin and water. The synthetic resin is in the form of an aqueous emulsion. The colored magnetic particles each include a protective layer formed on the coloring layer. The protective layer is formed from a second dispersion liquid constituted of synthetic resin dispersed in water.

Abstract: An ultraviolet light permeable filter for an ultraviolet detection light is equipped on a filter glass surface with a dielectric multi-film layer which allows a visible radiation of wave length from 694 nm to 780 nm to reflect on the layer. The 694 nm to 780 nm wave length does not penetrate through the multi-film layer. When placed in an ultraviolet detection system, this filter prevents the occurrence of a reddish halation during inspection and display of a flaw detection light.

Abstract: An ultraviolet light permeable filter for an ultraviolet detection light is equipped on a filter glass surface with a dielectric multi-film layer which allows a visible radiation of wave length from 694 nm to 780 nm to reflect on the layer. The wave length also does not penetrate through the multi-flim layer. This filter prevents a reddish halation occurrence during an inspection display of a flaw detection light, which is the main cause of overlooking a scratch or flaw pattern.

Abstract: An ultraviolet light permeable filter for an ultraviolet detection light is equipped on a filter glass surface with a dielectric multi-film layer which allows a visible radiation of wave length from 694 nm to 780 nm to reflect on the layer. The wave length also does not penetrate through the multi-flim layer. This filter prevents a reddish halation occurrence during an inspection display of a flaw detection light, which is the main cause of overlooking a scratch or flaw pattern.