Method and device for measuring a dimension of a body, and use of said method
AssigneeSamro-Bystronic Maschinen AG
InventorZwahlen Hermann
Life of this patent
Estimating the term…
Abstract
The image of a body which is located in a measuring zone is projected by a mirror into a camera having an optoelectric transducer, for instance a row of photodiodes. The stripe pattern is thrown onto the upper side of the body by a light beam which is inclined with respect to the projecting direction, said stripe pattern being imaged together with said body. The shape of the body in the vertical projection is detected by the camera and an associated electronic system, and the elevation of the body is deduced from the position of the stripe pattern thereon. Three dimensions, i.e. the actual size of the body, are thus determined. A sorting device can be controlled according to the detected size.
Claims29
A method for measuring a dimension of a body, comprising:
- observing the surface of the body in an observation plane parallel to the dimension of the body being measured;
- producing a light pattern comprising a series of stripes on the body by projecting light in a stripe pattern toward the body in a projecting direction inclined from the observation plane, and forming each of the stripes to have at least a first, second and third edge, with the stripes arranged parallel, the light being so directed at the body that the first and second edges of the stripes shining on the body cross the observation plane and the first edges are obliquely inclined from the observation plane;
- for the stripes then observable on the body at the observation plane, determining the positions of the intersections of the observation plane with the first and second edges of the stripes by registering the projections of the intersections on a projection line lying in the observation plane, wherein the intersections of the first and second edges are respectively represented by alternating dark to light and light to dark transitions;
- and
- calculating the dimension of the body to be measured at each stripe using the determined positions of the intersections of the first and second edges with the observation plane.
A device for measuring a dimension of a body comprising:
- means supporting the body to be measured at an observation plane;
- a light source located out of the observation plane and including means for directing light toward the object at the observation plane;
- a mask disposed between the light source and the body to be measured, the mask having a plurality of openings therethrough for passing light selectively to create a stripe pattern on the body;
- an essentially linear electrooptic sensor;
- optical means located in the observation plane for receiving the light reflected off the object in the observation plane and toward the optical means for imaging a line of predetermined length along the observation plane on the sensor.
Dependencies are inferred from the claim text.