US Patent 9581372 Ice maker

An ice maker includes an upper tray that includes a plurality of upper cells that each have a hemispherical shape and an ice making tube disposed at outer circumferential surfaces of the upper cells and configured to cool each of the upper cells. The ice maker also includes a lower tray that includes a plurality of lower cells that each have a hemispherical shape. The lower tray is rotatably connected to the upper tray. The ice maker further includes a rotation shaft connected to a rear end of the lower tray and a rear end of the upper tray, and configured to rotate the lower tray with respect to the upper tray.