OPTICAL LENGTH MEASURING GAUGE

摘要

PURPOSE:To achieve a larger measuring range and a higher measuring accuracy, by using a frequency modulation type light heterodyne length measuring gauge with the addition of a length measuring means employing trigonometrical survey. CONSTITUTION:Laser light l1 emitted from a semiconductor laser 1 is converted to a parallel light with a lens 2. The parallel light is divided with a beam splitter 3 in the direction perpendicular to each other and one part l2 of the light is used for heterodyne length measurement while the other part l3 thereof is done for trigonometrical survey. The light l2 is divided with a beam splitter 4 into lights l4 and l5 again and the light l4 for measurement is made to irradiate an object M to be measured through a lens system 5. The reflected light l6 of the light is made incident into a photo detector 6 to perform a heterodyne detection. The light l3 is reflected with a mirror 7 while the reflected light l9 is made to irradiate on the object M being measured through a convergent lens 8. The reflected light l10 is detected with a position sensor 10 and an absolute distance to the object M being measured is determined by an arithmetic means.