JPS646716A - Displacement measuring apparatus - Google Patents

Abstract

PURPOSE:To achieve a highly accurate measurement quickly, by arranging a laser light flux forming means to form a light stop matrix having light spots distributed in a 2-D manner, a matrix shutter and a means which checks a reflected laser luminous flux of a measuring surface to detect a displacement of the measuring surface. CONSTITUTION:Laser light from a light source 20 is taken into a guide 22 in an expanse of even intensity and a light spot matrix of (m) lines X (n) columns is observed on an output end face 26 through a matrix shutter 22. The laser light is incident into a measuring surface 30 with a lens 28. When the surface 30 is planar, the light is in a fixed magnification relationship with a light spot matrix on the end face 26. The reflected light is incident into a 2-D position detector 34 through a lens 32 and converted into an electrical signal to be inputted into a control processor 36. The light spot matrix on the end face 26 is in a fixed magnification relationship with an image on the detector 34. The processor 36 drives a liquid crystal shutter 24 of (m) lines X (n) columns sequentially to scan and the measuring surface 30 is scanned tow-dimensionally by a luminous flux with the optical axis moving sequentially, thereby enabling quick measurement of a displacement of the measuring surface by trigonometrical survey.