Abstract: A cutting edge is formed at a ridge between an upper surface and a side surface. In the side surface, a plurality of grooves are formed so as to extend from the side surface to the upper surface to divide the cutting edge, and the clearance angles within these grooves are formed so as to increase from one end of the cutting edge toward the other end of the cutting edge. This achieves a cutting insert having small cutting force and excellent cutting performance. Among the plurality of grooves, the groove nearest to the one end of the cutting edge has preferably a width increasing from the upper surface of the cutting insert toward the lower surface.

Abstract: A milling tool includes a cutting tool insert, roughly plate-shaped and having a rake face on an upper face and a flank on a side face and a main cutting edge at an intersection ridge line part at the intersection of the rake face and the flank, fitted in the periphery of a substantially cylindrical holder removably and so that an axial rake angle of the cutting edge ridge line of the main cutting edge is positive. When the cutting tool insert is rotated about the axis of rotation of the holder, the shape of the locus of rotation of the main cutting edge in a section parallel to the axis of rotation is made an approximate circular arc shape swelling outward with progress from the ends to the center.

Abstract: A milling tool includes a cutting tool insert, roughly plate-shaped and having a rake face on an upper face and a flank on a side face and a main cutting edge at an intersection ridge line part at the intersection of the rake face and the flank, fitted in the periphery of a substantially cylindrical holder removably and so that an axial rake angle of the cutting edge ridge line of the main cutting edge is positive. When the cutting tool insert is rotated about the axis of rotation of the holder, the shape of the locus of rotation of the main cutting edge in a section parallel to the axis of rotation is made an approximate circular arc shape swelling outward with progress from the ends to the center.

Abstract: A milling tool includes a cutting tool insert, roughly plate-shaped and having a rake face on an upper face and a flank on a side face and a main cutting edge at an intersection ridge line part at the intersection of the rake face and the flank, fitted in the periphery of a substantially cylindrical holder removably and so that an axial rake angle of the cutting edge ridge line of the main cutting edge is positive. When the cutting tool insert is rotated about the axis of rotation of the holder, the shape of the locus of rotation of the main cutting edge in a section parallel to the axis of rotation is made an approximate circular arc shape swelling outward with progress from the ends to the center.

Abstract: One embodiment of the present invention is a thin film transistor array including an insulating substrate, a plurality of thin film transistors and a sealing layer. The sealing layer is stripe-shaped and covers a plurality of the thin film transistors. The sealing layer is formed over the insulating substrate.

Abstract: A milling tool includes a cutting tool insert, roughly plate-shaped and having a rake face on an upper face and a flank on a side face and a main cutting edge at an intersection ridge line part at the intersection of the rake face and the flank, fitted in the periphery of a substantially cylindrical holder removably and so that an axial rake angle of the cutting edge ridge line of the main cutting edge is positive. When the cutting tool insert is rotated about the axis of rotation of the holder, the shape of the locus of rotation of the main cutting edge in a section parallel to the axis of rotation is made an approximate circular arc shape swelling outward with progress from the ends to the center.