Eye Movement Analysis of Japanese Sewing Scissors Craftsman

Abstract

The purpose of this study is to elucidate the skill of a blacksmith who has an ability to produce a pair of scissors whose two blades accurately comes across in the length, width and angle of each blade, even though they were produced separately. The processing method this scissor artisan employs is known as “So-hizukuri” (total forging process). The elucidation was conducted through observing the line of sight of the artisan using an eye movement analysis camera during his forging process. There are four main stages in the So-hizukuri process, and each stage involves several steps. In this study, we asked the scissor artisan to wear an eye movement analysis camera while engaging with the “Namatogi” (grinding before quenching) step in the “rough finishing before quenching” stage, which is the second in the four main stages, and observed his eye movements. We viewed the video recorded by the eye camera, and studied which parts of the blades he focused on, and the amount of time he focused on each part, when the artisan was comparing the two blades by laying one blade on top of the other. As a result, it was clarified that the artisan works on each of the left and the right blade alternately and gradually at every step toward the final stage, as the left and right blades of the scissors come across accurately when the scissors are completed. At any point in the process, he did not focus on forging one blade intensively, use a measuring instrument to measure the length of the blades, or use one of the blades as a standard to match the other blade.