Abstract: An manufacturing method of a display device may include the following steps: forming a transistor on a substrate; forming an insulating layer on the transistor; forming a conductive layer including silver on the insulating layer; forming a photosensitive member on the conductive layer; forming an electrode of a light-emitting element by etching the conductive layer; performing plasma treatment on a structure that comprises the electrode, the plasma treatment using a gas including a halogen; and removing a product that is resulted from the plasma treatment.

Abstract: The threaded engagement device includes a female thread portion and a male thread portion, which are engaged to each other through a plurality of threads formed along the axis direction. Each thread of the female thread portion and the male thread portion of the threaded engagement device includes a crest, a root, a stab flank and a load flank. The root of the female thread portion has a straight portion extending along the axis direction and a concave rounded portion. The root of the male thread portion has a concave rounded portion, wherein the radius of curvature of the rounded portion formed in the root of the male thread portion is larger than the radius of curvature of the rounded portion formed in the root of the female thread portion.

Abstract: A roll coupled to a separately manufactured axle rotates together with the axle in order to perform a rolling process. The roll includes an inner cylindrical surface, an outer cylindrical surface and both side faces, and at least one key way provided on at least one of the side faces is arranged adjacent to the inner cylindrical surface rather than said outer cylindrical surface, The key way is in a concave curved shape and is a portion of a spherical surface or of an ellipsoidal surface.

Abstract: A roll coupled to a separately manufactured axle rotates together with the axle in order to perform a rolling process. The roll includes an inner cylindrical surface, an outer cylindrical surface and both side faces, and at least one key way provided on at least one of the side faces is arranged adjacent to the inner cylindrical surface rather than said outer cylindrical surface, The key way is in a concave curved shape and is a portion of a spherical surface or of an ellipsoidal surface.