Research and Development

The non-contact 3-dimensional digitizer is a device that conducts operations (modeling) to take 3-dimensional data obtained by scanning the existing 3-dimensional object into the computer. In recent years, even in the industrial field, together with fields of research organizations and of CG image making, an attempt to utilize this digitizer for reverse engineering and inspection and to shorten the lead time of development and manufacture is drawing public attention. In Konica Minolta, we have developed a non-contact 3-dimensional digitizer that is highly accurate and is portable in a compact shape, and can be operated simply in feeling of a camera.

As a basic principle, a light cutting method by slit light is used. A slit laser beam, generated by a light projecting optical system, is applied on an object to be measured, and its reflected light is received by a CCD camera for triangulation. Then, 3-dimensional distance data for one line of slit light is obtained. By scanning slit light with a galvanic mirror, 3-dimensional data for the entire object to be measured are obtained.

By measuring angle θ, formed by baseline length L (distance between the light-receiving optical system and the light-projecting optical system), and by a laser beam to be projected, and angle of incidence Ø to the light-receiving optical system, absolute coordinates for laser beam position on the surface of the object to be measured are obtained from congruence conditions of a triangle. The symbol Ø is determined by an instruction value of a galvanic mirror, and θ is determined by incidence position coordinates n on the observation surface (CCD).

In Konica Minolta, with respect to each pixel of CCD, by obtaining “time barycenter” of slit light passing over the pixel, the light projecting angle of the slit light is obtained accurately, and highly accurate 3-dimensional distance information is obtained. Compared with a method to obtain “space barycenter”, there is the advantage that influence of sensitivity dispersion between CCD pixels and influence of dispersion in partial light and shadow of an object to be measured are hardly exerted.

Galvanic mirror: Mirror on which the rotation angle is made to be changed according to electric signals, by providing a shaft