Shaping of lens array mold surfaces by electrical discharge machining with a multiple-ball electrode

摘要

To efficiently produce lens array molds, we have proposed a method for shaping the elements of a lens array mold by electrical discharge machining (EDM). In the proposed method, the electrode is constructed by arranging conductive spherical balls in an array. By using this electrode in the EDM process, a number of lens elements can be simultaneously shaped on a mold surface to produce the mold efficiently. In a previous study, we developed an electrode with a single ball, and machined a lens array mold with 16 elements by the electrode in order to examine the fundamental removal characteristics of our proposed method. In the present study, we developed a multiple-ball electrode involving three balls. To demonstrate the effectiveness of the proposed method, a lens array mold with 48 elements was processed by the multiple-ball electrode. As a result, the lens array mold was successfully machined by the multiple-ball electrode. The experimental results demonstrate that the multiple-ball electrode enables the shaping of the multiple lens elements with short process time. These findings prove the effectiveness of our method with the multiple-ball electorde for the production of the lens array mold.