High precision focus correction system for multispectral filter-wheel cameras

Spectral Imaging is one of the current topics in science and industry. To capture spectral images many investigations were made in the past and will be done in the future. For reasonable and robust results in spectral imaging, a high image quality should be provided. One part of all spectral imaging systems is the optical system beside illumination and sensor characteristics. Lenses with a low chromatic aberration or systems, which can correct these aberrations, will lead to good image quality as mentioned. This article will show an approach to correct the chromatic aberrations, which is natural generated in refractive lens systems. This is realized by moving the image sensor with a very high precision. Therefore, investigations considering the accurate bearing of the sensor as well as an evaluation of the system characteristics were done and explained in this paper. Finally, the image sensor can be placed in less than microseconds with a micron accuracy of less than a pixel of the sensor. The tilt along the moving axis stays below one micron