A rangefinding approach by detecting the position and the incident angle of a light-stripe

This paper describes a novel triangulation-based light stripe rangefinding approach which can measure 3-D shapes for both specular and Lambertian objects. Although triangulation-based light stripe rangefinders have been widely used for many industrial applications, generally only Lambertian objects can be measured with these rangefinders. In order to apply this type of rangefinder to specular objects, it is necessary for the image sensor to detect the incident position and the angle of the light stripe However, it is difficult to detect the incident angle of the light stripe using conventional image sensors. Thus, we previously made the indirect detection of the angle possible by limiting the path of the light stripe that passed through the lens with shield masks. While the previous rangefinding approach based on this idea realized 3-D shape measurements for specular objects, it took a long time to acquire the 3-D shape data using this approach. We here devised a sensor which has the capability of detecting the incident angle directly, and then proposed a novel rangefinding approach using this sensor.