As the digital camera user base grows, so does the demand for digital imaging services. A new digital photo finishing system based on Liquid Crystal On Silicon (LCOS) is presented. The LCOS panel motherboard is made up of CMOS chip. Three individual streams of light (red, green, blue) are directed to corresponding Polarization Beam Spliter (PBS) to make the S polarization beam arrive at LCOS panel. When the Liquid appears light, the S polarization beam is changed to P polarization beam and reflected to pass through Polarization Beam Spliter. Compared with Thin Film Transistor-Liquid Crystal Display (TFT-LCD), LCOS has many merits including high resolution, high contrast, wide viewing angle, low cost and so on. In this work, we focus on the way in which the images will be displayed on LCOS. A liquid crystal on silicon microdisplay driver circuit for digital photo finishing system has been designed and fabricated using BRILLIAN microdisplay driver lite(MDD-LITE) ASIC and LCOS SXGA (1280×1024 pixel) with a 0.78"(20mm) diagonal active matrix reflective mode LCD. The driver includes a control circuit, which presents serial data, serial clock , write protect signals and control signals for LED, and a mixed circuit which implements RGB signal to input the LCOS. According to a minimum error sum of squares algorithm, we find a minimum offset and then shift RGB optical intensity vs voltage curves right and left to make these three curves almost coincide with each other. The design had great application in the digital photo finishing.
The thickness of metallic foil is measured by differential low-coherence interferometry. Two tandem Michelson Interferometers (MI), of which reflective surfaces measured are the corresponding surfaces of metallic foil, are used as basic interferometric system to obtain interference fringes on a spectrometer. Therefore, the interference fringes only depend on the path differences due to the thickness of metallic foil. The interference fringes are analyzed with a modified extremum method based on the least root mean square (RMS) deviation. The experimental results on thickness measurement are presented.
A new differential white light interference technique for the thickness measurement of metal foil is presented. In this work, the differential white light system consists of two Michelson Interferometers (MI) in tandem, of which reflective surfaces measured are corresponding surfaces of metal foil. Therefore, the measured result only relates to the thickness but not to the position of metal foil. The method is non-contact, non-destructive, has advantage of high accuracy, fast detection and compact structure. Theoretical analysis and preliminary experimental results have shown that the technique can measure the thickness of foil in the range of 1 μm to 80 μm with satisfactory accuracy and repeatability.
A thickness measurement system of ultra-thin metal foils using differential white light interference has been investigated, where a data processing scheme, using wavelet transform has been carried out. The analysis of simulation result indicates that this method has high accuracy and can be applied in the course of actual measurement.