Patent ID: 9395178
Filing Date: 2016-07-19
CPC Classification: G01B,G01S

Claim Text:
1. A position measuring device comprising: a light emitter configured to emit laser light along a first optical axis for measurement of a position of an object to be measured; an image capturer provided on a second optical axis, the second axis being oblique to the first optical axis; a first beam splitter provided on the first optical axis; a first light receiver configured to receive a first light that is reflected by the object and propagates along the first optical axis toward the light emitter and that is reflected by the first beam splitter, the first light receiver further configured to output a first signal corresponding to an intensity of the first light; a second light receiver configured to output a second signal corresponding to an intensity of a second light that is diffused by the object and propagates along the second optical axis toward the image capturer; a calculator configured to calculate the position of the object to be measured based on the light propagating along the second optical axis, and to determine an occurrence of an occlusion based on a difference of the intensity of the first light and the intensity of the second light; and a controller configured to control an intensity of the laser light when the calculator determines an occurrence of the occlusion, wherein the controller controls the intensity of the laser light based on the second signal when a difference between the first signal and the second signal is smaller than a predetermined threshold, and wherein the controller is further configured to control the laser light to have a predetermined intensity when the difference between the first signal and the second signal is equal to or greater than the predetermined threshold.