Title:
ABSOLUTE POSITION DETECTOR
Document Type and Number:
Japanese Patent JPH05312511
Kind Code:
A
Abstract:
PURPOSE:To enhance resolving power by enlarging the conversion coefficient and improving uniformity between elements. CONSTITUTION:A mask slit pattern MSP corresponding to a horizontal pixel array is formed on the imaging face of an image sensor 2. The pattern MSP is formed such that a slit SLT corresponds to the central part of a light receiving element PE. An encode board 1 is applied tightly onto the surface of the image sensor 2 on which the pattern MSP is formed. The tightly contacting faces of the encode board 1 and the image sensor 2 are then smoothed so that they can slide each other. Light transmitting width of the slit SLT varies in the range of 0-wM as the encode board 1, and thereby a stripe pattern SP, moves in Z direction thus varying a pixel signal between minimum value MIN and maximum value MAX. Consequently, conversion coefficient can be increased by decreasing the slit width. Since position detecting accuracy is determined by machining accuracy of the pattern MSP and stable central part is mainly used in the fabrication process of light receiving element PE, uniformity is improved between the elements.
Inventors:
OKA YASUO
Application Number:
JP40788890A
Publication Date:
November 22, 1993
Filing Date:
December 27, 1990
Export Citation:
Assignee:
SONY CORP
International Classes:
G01B11/00; G01D5/34; G01D5/347; (IPC1-7): G01B11/00; G01D5/34
Attorney, Agent or Firm:
Kunio Yamaguchi (1 person outside)