Film thickness gauge

Abstract

Abstract PURPOSE:To enable measuring of a thickness of a film covering a large area by a simple constitution, by a method wherein, in an interference system film thickness gauge, a projection surface and a collecting surface are formed with optical fibers alined on a rectilineal line. CONSTITUTION:A film 5 to be measured is irradiated with a white light from a xenon lamp 1 passing through a focusing leans 2 and a plural number of optical fibers 3. The optical fibers 3 are alined on a rectilineal line through the aid of a crosspiece, and are positioned perpnedicularly to the moving direction of the film 5. A light passing through the film is led to a spectroscope 9 after passing through fibers 8. The end surface of the fibers 8 are collected in an overlapping manner in an incident slit 10 and in the direction of the length of the slit. The light forms a spectral picture on a collecting surface of a photographing element 12 by means of a concave spherical diffraction grid 11. Their respective lights from the fibers correspond to A, B, and C. A film thickness is found from a wave length corresponding to a maximum spectrum related to each of the bands A, B, and C. The increase in the number of the fibers permits the improvement of the measuring density in the direction of the width of the film.

Inventors

• 👤 Masahito Koike
• 👤 Kunihiko Okubo

Bibliographic Details