31 October 1996 Using TDI camera with nonzero viewing angles for surface inspection
Author Affiliations +
Abstract
A variety of time delay and integration (TDI) arrays have been developed. The TDI image sensor offers significant improvement in performance over a linear CCD-sensor with respect to sensitivity. This is particularly significant in low level operations since the exposure time is increased by a factor which is equal to the number of the TDI stages in the sensor. Typically, the use of a TDI camera is restricted to cases where the surface is viewed from the direction of the surface normal. This is because the TDI-camera sensor has to be parallel to the viewed surface plane, in order to avoid a decrease of image quality due to varying magnification. However, in certain visual inspection applications it would be advantageous to use non-zero viewing angles. Three different solutions were tested and analyzes: a commercial shifting lens, standard lenses with an extension structure to support the lens in the shifting position and a commercial shifting and tilting lens. The results indicate that the TDI-camera can be used with viewing angles up to 30 degrees from the surface normal,which has been found to be the optimal viewing angle in some visual inspection applications.
© (1996) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Jari Miettinen, Xu Zelin, Heikki J. Ailisto, "Using TDI camera with nonzero viewing angles for surface inspection", Proc. SPIE 2908, Machine Vision Applications, Architectures, and Systems Integration V, (31 October 1996); doi: 10.1117/12.257249; https://doi.org/10.1117/12.257249
PROCEEDINGS
8 PAGES


SHARE
Back to Top