A Lampshade Design Method by Paper Folding and Luminance Distribution on the Lampshade Designed by the Method. -Skew Quadrilateral Membrane Folding Method-

Abstract

Historically, Japanese traditional lampstand 'Andon', was manufactured from paper. And paper folding method was adopted into some Andon and western lampshade1). If we put non-flat texture on the surface of such lampshade with paper folding method, nonuniform luminance distribution appears on the surface according to basic laws of illuminance. Such nonuniform luminance on the surface of lampshade contributes to easier recognition of its shape and more attractive appearance. Yoshimura/Diamond pattern2) is one of the most typical paper folding methods in the field of lampshade design. This pattern is known as a structure of crashed cylinder and structure of building roof, and has been made good use in commercial lampshade products1). Yoshimura pattern structure includes a set of skew quadrilaterals which is not on a plane surface and each quadrilateral is constructed by two planar triangles. Consequently, lampshades manufactured with Yoshimura pattern have nonuniform luminance distribution overall, however, luminance distribution within a skew quadrilateral unit is discontinuous at boundary of two planar triangles which compose a skew quadrilateral unit. Author found that similar shape can be constructed by modified Yoshimura pattern and develop the method to ‘Skew Quadrilateral Membrane Folding’ method. In this paper, author indicated principle of the proposed paper folding method at first. In the second, features of the shape made by proposed method and the luminance distribution on the shape are explained. Next, examples of applications of proposed method are indicated. Finally, an example of application of the shape made by proposed method in the field of education is explained.