The illumination system of optical microscopes used in the field of electronic failure analysis is a complex and adaptable structure. Properly setting it to fulfill the requirements of a wide variety of tasks sets the operator a challenge. Backlight illuminators complement traditional ring illuminators well for stereo microscopy. Contrast of the object under observation and saturation of the background can be controlled to expose fine features in the captured image.
I developed the prototype of a variable brightness and color temperature background illuminator to address the aforementioned situation, considering user requirements. While doing so, I designed and implemented an LED table evenly populated with cool and warm white LEDs, its driver and controller circuits, together with the controller firmware.
Measurement of the homogeneity of light distribution over the table’s surface fared promising results laying out further ideas for development. Although the results are promising, to get a device fit for everyday usage further development is required.