Title:
LASER INTERFERENCE MEASURING INSTRUMENT
Document Type and Number:
Japanese Patent JPH0222505
Kind Code:
A
Abstract:
PURPOSE:To accurately measure the shape of a fine part by picking up an image of a measured surface with low magnification and high magnification under the same conditions. CONSTITUTION:The light beam emitted by a laser light source 10 is changed in direction by 90 deg. through a mirror 12 and the made into parallel luminous flux by a beam expander 14 to be made incident on a half-mirror 16. This light beam is changed in direction by 90 deg. and the light is emitted on the surface 18 to be measured and also emitted on a reference surface 20. The reflected light beams from the surface 18 to be measured and reference surface 20 are made incident on a low-magnification image forming lens 26 through a beam splitter 24. Further, the light beam which is reflected by the splitter 24 is made incident on a high-magnification image forming lens 30 as interference light. Further, a camera 28 for low-magnification measurement picks up an image of interference fringes corresponding to the low magnification and sends its image signal to a memory 34. Further, a camera 32 for the high magnification picks up an image of interference fringes corresponding to the high magnification and sends its image signal to a memory 40. Thus, the shape of the fine part is accurately measured.
Inventors:
IWAMOTO YOJIRO
Application Number:
JP17227888A
Publication Date:
January 25, 1990
Filing Date:
July 11, 1988
Export Citation:
Assignee:
TOKYO SEIMITSU CO LTD
International Classes:
G01B11/24; G01B11/30; (IPC1-7): G01B11/24; G01B11/30
Attorney, Agent or Firm:
Kenzo Matsuura
Next Patent: JPH0222506