Title:
THICKNESS MEASUREMENT FOR PHOTOSENSITIVE LAYER
Document Type and Number:
Japanese Patent JPH01152305
Kind Code:
A
Abstract:
PURPOSE:To achieve a non-contact measurement of the thickness of a photosensitive layer, by measuring distances between a reference surface and a conductive substrate and the surface of a photosensitive layer by electric and optical method to determine the difference between the results. CONSTITUTION:Light from a projector section 31 is emitted onto the surface 21 of a photosensitive layer 2 and received with a light receiving section 32 to calculate a distance to the surface 21 thereof 2 from a reference surface 5 according to the current angle of incidence. On the other hand, an eddy current is generated in a photosensitive substrate 1 by an alternating magnetic field generated with an electromagnetic sensor 4 to calculate a distance between the reference surface 5 and the surface 11 of the substrate 1 from a value of a magnetic field fed back to the sensor. The difference between the two distances is computed to determine the thickness of the photosensitive layer 2. This enables non-contact measurement of the thickness of the photosensitive layer 2.
Inventors:
KUROSAWA KIMIO
Application Number:
JP31130487A
Publication Date:
June 14, 1989
Filing Date:
December 09, 1987
Export Citation:
Assignee:
FUJI ELECTRIC CO LTD
International Classes:
G01B21/08; G03G5/00; (IPC1-7): G01B21/08; G03G5/00
Attorney, Agent or Firm:
Iwao Yamaguchi