A high-resolution, wide-field, optically coupled, digital CCD camera for the JEOL 4000-EX intermediate-voltage electron microscope
We have designed and constructed a camera system for acquisition of digital images directly from a JEOL 4000-EX 400 kV transmission electron microscope. Our major goal was the ablity to sample and test images for suitability for various forms of image processing and analysis during a session on the microscope, rather than after processing and digitizing films, so that adjustments could be made while the specimens were still in place. Our design parameters were 1) good resolution, in terms of pixels in the image, 2) wide field, so low magnification images could be obtained, 3) no interference with normal operation of the microscope, including the film camera, and 4) minimal modification of the microscope.Cameras positioned below the film camera have narrow fields of view because of increase in image size below the film camera and the small size of CCD targets relative to film. We chose a position above the microscope's fluorescent viewing screen, where there is a convenient port on the 4000-EX, and achieved a field width approximately equal to that on film.