Abstract: In a dimple processing method for forming dimples on a curved surface of a workpiece, a cutting tool having a cutting edge on a rod-shaped body is rotated about a central axis of the cutting tool. The workpiece is rotated about a first axis. The cutting tool or the workpiece moves on a virtual plane through which the first axis passes or on a plane parallel to the virtual plane. The cutting tool or the workpiece moves such that the tip end of the cutting tool follows the curved surface of the workpiece. The cutting edge forms one or more dimple on the curved surface each time the cutting tool rotates.

Abstract: A plurality of dimples are formed on a processing surface of a workpiece. An aspect ratio of each dimple is greater than or equal to 5.0 and less than or equal to 50.0. The aspect ratio is a ratio of a length of the dimple measured in a longitudinal direction to a lateral width of the dimple measured in a direction perpendicular to the longitudinal direction.

Abstract: A recorder for recording analog data on recording paper moving in a fixed direction includes a recording unit for recording the analog data on the recording paper, a setting unit for setting scale maximum value and scale minimum value of graduation lines recorded on the recording paper, a main control unit for calculating the recording position of the graduation lines determined by the scale maximum value and scale minimum value and controlling the recording means, the setting means, and a graduation line recording unit for recording on the recording paper the graduation lines based on the graduation line position calculated by the main control unit.