Pressure presentation strength for calligraphy brushwork instruction

In this paper, an instruction system of calligraphy brushwork for apprentices is introduced. In order to write a well-shaped character, the brush is required to be operated skillfully. Calligraphy experts operate a brush in multi-degrees of freedom, however, for apprentices, it is tentatively required to control a brush in low-degree of freedom (a horizontal plane) as a beginning training. The reason is that the shape of a character becomes better to an extent by correcting a brushwork slightly, and a slight instruction in a horizontal plane enables this. In the authors' developed system, the motion of the student's brush (handwriting) is measured by Leapmotion, and if the brush goes far from the reference trajectory, the developed pressure presentation device stimulates the student's wrist as an instruction at the moment. Although the structure of the developed instruction system is so elementary, the system is expected that it can induce the student to correct the handwriting. For this purpose, calligraphy training experiments with several participants were carried out. The reaction times and the brush overruns from the reference trajectories for three kinds of pressure strength were measured during brushworks. As results, it was confirmed that the reaction times of participants and the brush overruns became shorter significantly, if the strength of the pressure presentation was strengthened.