|
Inner profile measurement is an important matter in such fields as medicine, dentistry and anthropology as well as
mechanical engineering and other industrial applications. Here we describe recent development of our measurement
principle for inner diameter of pipes and/or holes. The key device in this technique is a ring beam device which
consists of a conical mirror and a laser diode. And the fundamental principle is based on optical sectioning without
using any contact type stylus. The optically sectioned profile of an inner wall of a pipe-like object is analyzed to give
the inner profile in addition to the inner diameter. This optical instrument with a simple and small configuration is
now under development for practical uses. In our hitherto trial experimental works, the availability of this instrument
has been evaluated in many cases and availability for practical applications is expected, especially, for measurement
and inspection of mechanical components and elements besides pipes. This ring beam device consisting of a conical
mirror and a LD is assembled to form a disk-like light sheet. We show measurement result of pipes and holes, and, at
the same time, report a compact inner profile measuring instrument at this point. Both the ring beam device and a
miniaturized CCD camera are fabricated into a glass tube. Availability of this instrument is shown by measuring the
inner profiles of various pipes. In response to this trial, there appeared a strong request that not only the internal but
external profiles should be measured simultaneously. Therefore we propose potentially possible method for
measurement of external profile at the same time with internal profile. If one pair of concave mirrors are used in our
arrangement, external profile is captured. In combination with inner profile measurement technique, simultaneous
measurement of inner and outer profiles becomes attainable. A measurement result on a bevel gear shows availability
of here proposed principle. In addition, we are trying to extend our technique to check defects and/or flaws on the
inner wall of pipe-like objects.
|
