Title:
SHAPE MEASURING APPARATUS
Document Type and Number:
Japanese Patent JPS63229314
Kind Code:
A
Abstract:
PURPOSE:To simplify the whole of a system and to inexpensively measure a surface shape with high accuracy, by making an object to be measured and the light receiving surface of a sensor for discriminating a focus matching state optically conjugate and making the object to be measured and the light receiving surface of a sensor for measuring an angle of inclination optically non-conjugate. CONSTITUTION:The beam from a beam source 8 is converted to parallel beam by a lens 10 and reflected by a half mirror 16 through a polarizing beam splitter 14 to form a spot on the surface of an object 50 to be measured by a lens 20. The reflected beam from the surface of the object 50 to be measured is reflected by the lens 20, a 1/4 wavelength plate 8, the mirror 16 and the splitter 14 to form a spot on an optical sensor 26 through BPF 32 and a lens 24. That is, the measuring point of the object 50 to be measured and the sensor 26 are conjugate with respect to an optical system 2 to exclude the effect of the angle of inclination of the surface of the object 50 to be measured. The measurement of the angle of inclination is same as the optical system up to the process wherein the beam from the beam source is incident on the object 50 to be measured and reflected to reach the plate and different from said system on and after the mirror 16. The beam from the lens 20 is received by a sensor 30 and the height of the beam from an optical axis X is calculated to measure the angle of inclination.
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Inventors:
OWADA MITSUTOSHI
NIWA YUKICHI
NIWA YUKICHI
Application Number:
JP6304087A
Publication Date:
September 26, 1988
Filing Date:
March 18, 1987
Export Citation:
Assignee:
CANON KK
International Classes:
G01B11/24; (IPC1-7): G01B11/24
Attorney, Agent or Firm:
Takanashi Yukio