Site: Osaka Sangyo University
3-1-1 Naka-kakiuchi, Daitou-shi
Osaka 574, Japan

Date Visited: 13 December 1995

JTEC Attendees: P. Fussell (report author), K. Narayanan


Professor Yoji Marutani


Professor Yoji Marutani is one of the original innovators of liquid phase photocuring rapid prototyping. His work originated in 1984, resulting in several patent applications. In 1985 he organized a small group of companies, including Minolta, Bridgestone, Shinto, and others, as a research consortium. He dissolved the consortium in 1987, and in 1988 he became connected with Mitsubishi. In that same year, the first SOUP machine was delivered to his laboratory, and the second machine to the company.

Since that time Professor Marutani has done other basic concept work, including an effort several years ago to use a YAG laser to irradiate a thermally sensitive resin loaded with C or Al2O3 -- the ceramic absorbs the energy, thus locally heating and curing the resin. He is now working on a cheaper scanning method (discussed below).

Professor Marutani now has 13 undergraduate students and 3 master's students. Professor Kamitani, an assistant professor at Osaka Sangyo, is also working with him. One student is working on the new curing device, while the others work on face recognition, face movement, word recognition and stereo imaging, and inspection of parts. He has one PhD student who is working on genetic algorithms for recognition of Japanese characters.


Professor Marutani's new work is to develop an extremely low-cost device for part fabrication. His current scheme starts with a slice of a CAD file, which is used to control switches that permit light to travel along fiberoptic paths to a scan head; the scan head traverses the vat and cures the sliced cross-section. His current experiments are preliminary. Schematically the work is as shown in Figure OSU.1.

Figure OSU.1. Prof. Marutani's part-fabrication scheme.


Professor Marutani has very basic equipment suitable for the concept study of ideas. This includes a CO2 laser (Synrad), an XY plotter device (which he principally uses to avoid the danger of exposing his students to laser radiation), and a set of mercury xenon lamps.


Professor Marutani has exclusively used Asahi Denka materials. His most recent work has been with HS673, and his previous thermal work was with KRM-2110, as well as others.


Professor Marutani mentioned the support patent held by CMET/Osaka (JP 63-252795, 5 October 1988) as being significant in the Japanese market.

He mentioned that of attendees at symposium meetings, held twice a year, 70% were from companies, 1 or 2 were from government, and the remainder were from universities.

Professor Marutani also mentioned that there was little university work in other materials, but that a Professor Osakada of Osaka University was working in metal powders.

Published: September 1996; WTEC Hyper-Librarian