Optical measurement device

Abstract

A white light confocal optical measurement device capable of detecting abnormalities in a received light waveform; the optical measurement device includes: a light source; an optical system; a light receiving unit; and a processor configured to compute the distance from the optical system to the measurement object on the basis of a received light intensity of the wavelength components received in the light receiving unit. The processor compares a received light intensity of a wavelength component to a reference value for the wavelength component for a plurality of wavelength components in a waveform representing the light received, and detects an abnormality in the received light waveform when the amount of change in the received light intensity compared to the reference value therefor is greater than or equal to a predetermined threshold for any wavelength component in the plurality of wavelength components.

What is claimed is: 
     
         1 . An optical measurement device comprising:
 a light source configured to emit illumination light including a plurality of wavelength components;   a sensor head configured to introduce an axial chromatic aberration into the illumination light from the light source and to receive reflection light reflecting from a measurement object where at least a portion of the measurement object lies along a line extending from the optical axis of the optical system;   a light receiving unit configured to separate the reflection light received at the sensor head into wavelength components and thereby receive the light having the wavelength components;   a processor configured to compute the distance from the optical system to the measurement object on the basis of a received light intensity of the wavelength components received in the light receiving unit; and   a light guide configured to guide light between the light source and the sensor head and between the sensor head and the light receiving unit,   wherein the processor detects an abnormality that can occur by a reflection of a portion of the illumination light from the light source partway through the light guide, on the basis of the light intensity of the light received in the light receiving unit.   
     
     
         2 . The optical measurement device according to  claim 1 , wherein the detection of the abnormality is based on a result of a comparison between the light intensity of the light received in the light receiving unit and a reference value. 
     
     
         3 . An optical measurement device comprising:
 a light source configured to emit illumination light including a plurality of wavelength components;   a sensor head configured to introduce an axial chromatic aberration into the illumination light from the light source and to receive reflection light reflecting from a measurement object where at least a portion of the measurement object lies along a line extending from the optical axis of the optical system;   a light receiving unit configured to separate the reflection light received at the sensor head into wavelength components and thereby receive the light having the wavelength components;   a processor configured to compute the distance from the optical system to the measurement object on the basis of a received light intensity of the wavelength components received in the light receiving unit; and   a light guide configured to guide light between the light source and the sensor head and between the sensor head and the light receiving unit, the light guide including a connecting part,   wherein the processor detects an abnormality in an intensity of a returning light that can occur by a reflection of a portion of the illumination light from the light source at a connecting part, on the basis of the light intensity of the light received in the light receiving unit.   
     
     
         4 . An optical measurement device comprising:
 a light source configured to emit illumination light including a plurality of wavelength components;   a sensor head configured to introduce an axial chromatic aberration into the illumination light from the light source and to receive reflection light reflecting from a measurement object where at least a portion of the measurement object lies along a line extending from the optical axis of the optical system;   a light receiving unit configured to separate the reflection light received at the sensor head into wavelength components and thereby receive the light having the wavelength components;   a processor configured to compute the distance from the optical system to the measurement object on the basis of a received light intensity of the wavelength components received in the light receiving unit; and   a light guide configured to guide light between the light source and the sensor head and between the sensor head and the light receiving unit by an optical cable, the light guide including a combiner/divider between the light source and the sensor head and between the sensor head and the light receiving unit,   wherein the processor detects an abnormality due to defectiveness of the combiner/divider, on the basis of the light intensity of the light received in the light receiving unit.   
     
     
         5 . An optical measurement device comprising:
 a light source configured to emit illumination light including a plurality of wavelength components;   a sensor head configured to introduce an axial chromatic aberration into the illumination light from the light source and to receive reflection light reflecting from a measurement object where at least a portion of the measurement object lies along a line extending from the optical axis of the optical system;   a light receiving unit configured to separate the reflection light received at the sensor head into wavelength components and thereby receive the light having the wavelength components;   a processor configured to compute the distance from the optical system to the measurement object on the basis of a received light intensity of the wavelength components received in the light receiving unit; and   a light guide configured to guide light between the light source and the sensor head and between the sensor head and the light receiving unit by a plurality of optical cables, the light guide including at least one connector for connecting the plurality of optical cables in series,   wherein the processor detects an abnormality related to defectiveness of the at least one connector, on the basis of the light intensity of the light received in the light receiving unit.   
     
     
         6 . An optical measurement device comprising:
 a light source configured to emit illumination light including a plurality of wavelength components;   a sensor head configured to introduce an axial chromatic aberration into the illumination light from the light source and to receive reflection light reflecting from a measurement object where at least a portion of the measurement object lies along a line extending from the optical axis of the optical system;   a light receiving unit configured to separate the reflection light received at the sensor head into wavelength components and thereby receive the light having the wavelength components;   a processor configured to compute the distance from the optical system to the measurement object on the basis of a received light intensity of the wavelength components received in the light receiving unit; and   a light guide configured to guide light between the light source and the sensor head and between the sensor head and the light receiving unit by a plurality of optical cables, the light guide including at least one connector for connecting the plurality of optical cables in series,   wherein the processor detects an abnormality related to a length of the series connection of the plurality of optical cables, on the basis of the light intensity of the light received in the light receiving unit.   
     
     
         7 . An optical measurement device comprising:
 a light source configured to emit illumination light including a plurality of wavelength components;   a sensor head configured to introduce an axial chromatic aberration into the illumination light from the light source and to receive reflection light reflecting from a measurement object where at least a portion of the measurement object lies along a line extending from the optical axis of the optical system;   a light receiving unit configured to separate the reflection light received at the sensor head into wavelength components and thereby receive the light having the wavelength components;   a processor configured to compute the distance from the optical system to the measurement object on the basis of a received light intensity of the wavelength components received in the light receiving unit; and   a light guide configured to guide light between the light source and the sensor head and between the sensor head and the light receiving unit by a plurality of optical cables, the light guide including at least one connector for connecting the plurality of optical cables in series,   wherein the processor detects an abnormality due to damage or dirt on the at least one connector, on the basis of the light intensity of the light received in the light receiving unit.   
     
     
         8 . An optical measurement device comprising:
 a light source configured to emit illumination light including a plurality of wavelength components;   a sensor head configured to introduce an axial chromatic aberration into the illumination light from the light source and to receive reflection light reflecting from a measurement object where at least a portion of the measurement object lies along a line extending from the optical axis of the optical system;   a light receiving unit configured to separate the reflection light received at the sensor head into wavelength components and thereby receive the light having the wavelength components;   a processor configured to compute the distance from the optical system to the measurement object on the basis of a received light intensity of the wavelength components received in the light receiving unit; and   a light guide configured to guide light between the light source and the sensor head and between the sensor head and the light receiving unit by a plurality of optical cables, wherein the plurality of optical cables are optical fibers,   wherein the processor detects an abnormality due to damage or dirt on an end surface of the optical fiber, on the basis of the light intensity of the light received in the light receiving unit.