Title:
AUTO-FOCUSING CONTROLLER USING LASER LIGHT
Document Type and Number:
Japanese Patent JPH01224713
Kind Code:
A
Abstract:
PURPOSE:To obtain an auto-focusing controller of high sensitivity by optically deflecting a condensed laser light on the surface of an object to be measured to detect a reflected light intensity pattern and detecting a minimum intensity, a maximum intensity, and a pattern width at two points different from each other in the focus position and controlling focusing in accordance with the change of respective values. CONSTITUTION:The direction of movement of a focusing direction distance control means 8 is determined in accordance with detection results of a minimum and maximum intensity detecting means 11 and a pattern width detecting means 12. The distance is changed in the direction determined by a control direction discriminating means 13 in accordance with the distance change of a second size issued by the focusing direction distance control means 8. The reflected light intensity pattern is detected for each state of the distance, and the pattern which is detected by a pattern width detecting means 12, and the detected pattern width and a preliminarily set reference pattern width are compared with each other. The distance change of the second size is so controlled that the detected pattern width is narrower than the reference pattern width. Thus, the object to be measured is quickly set to a desired focusing state with simple software.
Inventors:
FUJITA HIROO
Application Number:
JP5073988A
Publication Date:
September 07, 1989
Filing Date:
March 04, 1988
Export Citation:
Assignee:
CITIZEN WATCH CO LTD
International Classes:
G01B11/00; G02B7/32; (IPC1-7): G01B11/00; G02B7/11