Title:
METHOD FOR INSPECTING TRANSPARENT SUBSTANCE BY REFLECTED ILLUMINATION
Document Type and Number:
Japanese Patent JPH0321809
Kind Code:
A
Abstract:
PURPOSE:To utilize a pattern inspection device and to inspect a transparent chart by illuminating the transparent chart placed on a reflecting surface from a transparent chart side and projecting a luminous flux which is transmitted through the chart and reflected by the reflecting surface on a screen by a projecting lens. CONSTITUTION:The transparent chart is placed on a mirror arranged on a table 11 perpendicularly to the optical axis Ax1 of the projecting lens 40. Diver gent light emitted from a xenon lamp 61 is condensed on a half size mirror 53 by a Fresnel lens 68 through parabolic mirrors 62-64, a diaphragm 65, a filter 66 and a shutter 67. The lens 68 forms the image of a 2nd-order light source on the mirror 53. The illuminating luminous flux is reflected by the mirror 53, transmitted through the chart and reflected by the mirror, then trans mitted through the chart again and made incident on the lens 40. Since the mirror 53 is set at a position which is the entrance pupil of the lens 40, the regular reflection component of the illuminating light is transmitted through a side where the mirror 53 is not provided and forms the image of the chart on the screen 30 with high contrast.
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Inventors:
MATSUI YUJI
AOYAMA MASAAKI
AOYAMA MASAAKI
Application Number:
JP15757689A
Publication Date:
January 30, 1991
Filing Date:
June 19, 1989
Export Citation:
Assignee:
ASAHI OPTICAL CO LTD
International Classes:
G01B11/24; G01N21/84; G01N21/88; G01N21/956; G01N21/958; (IPC1-7): G01B11/24; G01N21/84; G01N21/88
Attorney, Agent or Firm:
Tamio Nishiwaki
Next Patent: PATTERN INSPECTING DEVICE