Mathematical modelling and experimental study of spatial light modulatorsWe present a simple technique for real time liquid crystal panel intensity transmission calibration. The experimental method is based on studying a test image displayed on the modulator. Using those images, we can display different calibration curves. The visualization of the intensity transmission curves in real time allows to adjust the correct control parameters (brightness, contrast, gamma, etc.) that gives a linear response of the intensity transmission with the gray-levels.  The different squares of the test have 27x27 pixel size. The test is displayed and capture according with the optical setup shown bellow
The image captured by the CCD gives the intensity transmission for all gray levels displayed in the LCD at the same time. The advantage of this method in comparison with previous calibration methods is that no sequential gray level images are required to be sent to the LCD in order to capture the transmission. All information is obtained at once so the method is significantly faster than previous ones.
Previous figure is the result of three possible calibration curves for three different configurations of brightness and contrast. The advantage of the new method is that we are visualizing in real time the calibration curves. Then, a faster and accuracy adjustment of brightness and contrast can be made in order to obtain a linear response between grey levels and the intensity transmitted by the LCD. PAPERS ON THE SUBJECT: |
