| 摘要 |
PURPOSE:To obtain a stable reflected light intensity signal without the effect of noises, by guiding the light from a powerful light source to an optical thin film and to a monitoring light receiving part which is separated from the light source through optical fibers, and guiding the reflected light from the optical thin film to a light receiving part which is separated from the light source through an optical fiber. CONSTITUTION:The light from an electronic flash discharge tube 44, which is controlled by a microcomputer 42, is guided to a monitor glass 30 in a vacuum evaporating device through an optical fiber 36 and also guided to a monitoring light detecting part 48, which is separated from the light source 44, through an optical fiber 46. Meanwhile, the reflected light from the monitor glass 30 is guided to a light detecting part through an optical fiber 38. The outputs of the light detectors 48 and 50 are processed in a processing circuit 52, and a reflected light intensity signal is inputted to the microcomputer 42. Since the powerful light source 44 and the light detecting parts 48 and 50, which are separated from the light source, are used, the stable reflected light intensity signal without the effect of noises can be obtained. |
