Ink-Jet Printing of Color Optical Filters for LCD Applications

At the age of multi-media, portable electronic devices such as mobile phones, personal digital assistant and handheld gaming systems have increased the demand for high performance displays with low cost production. Inkjet printing color optical filters (COF) for LCD applications seem to be an interesting alternative to decrease the production costs. The advantage of inkjet printing technology is to be fast, accurate, easy to run and cheaper than other technologies. In this master thesis work, we used various disciplines such as optical microscopy, rheology, inkjet printing, profilometering and colorimetry. The specific aim of the thesis was to investigate the feasibility of using company-A pigment formulation in inkjet production of COF for active matrix LCD applications. Ideal viscosity parameters were determined from 10 to 20mPa·s for easy inkjet printing at room temperature. The red pigments used are fully dispersed into the solvent and present an excellent homogenous repartition after printing. Thickness investigations revealed that the printed COF were equal or slightly thicker than typically manufactured ones. The colorimetry investigations demonstrated color coordinates very close to the NTSC red standard. LED backlighting seems to be a valuable solution to combine with the printed COF regarding to the spectrum and color analysis. The results on this thesis will increase the understanding of inkjet printing company-A pigments to produce COF for LCD applications.

Färgstyrning av kontorsutrustning

Color management has become more common now than ever in the graphic trade. Calibration andcharcterization are words that are mentioned very often when it comes to controlling colors andwhen you want a printed picture to look the same as an original photograph. The problem is thatthere are not so many people that has the knowlegde about this subject. Even if a printer supportscolor management it is not sure that the result is going to be satisfied and that a printed picture isgoing to look the same as the original.The printers which were used were Hp DeskJet 970 Cxi, Xerox Docu Color 12 and AgfaChromapress 50i. The theory of color, colour management and the equipment which were usedare described in the first stage. The second stage describes calibration and characterization ofmonitors, scanners and printers. Finally the result of created ICC-profiles is set by visual comparisionof a photographs original colours and a scanned and printed photograph.The results of calibration and characterization were varying a lot. Agfa Chromapress 50i was theonly printer which could produce a succesful calibration. Agfa Chromapress 50i and XeroxDocuColor 12 gave the best results when comparing original photographs with printed pictures ifthey were separated with ICC-profiles. ICC-profiles created for Hp DeskJet 970 Cxi achievedundesirable effects. This was the only printer that gave a bad result both with and without ICCprofiles.The reason for this miserable result can depend on the printers unability to fully supportcolor management.

Vitpunktsförskjutningens påverkan på ICC-profiler vid användande av optiska vitmedel

The connection between fluorescence and color management still is a relatively unexplored area. Thefollowing composition analyses the theory that when printing on fluorescent ink jet paper using ICCprofilesa more yellow print will appear. In theory the ICC-profile compensate for blue light that fluorescefrom the paper with the complementary color, yellow. The human eye apprehands this fluorescentlight as white.When categorizing a number of ink jet qualities some tests to indicate change of color in the final printwere made. Five qualities were chosen for further analyses, each with different white point. TheTC3.5CMYK target was prined on an ink jet printer and measured with different filters for the measurementequipment, GretagMacbeth Spectrolino. U- and UV-filters were used during the testings.From the measurement data ICC-profiles were made to make it possible to watch how the profiles compensatefor the blue change of color that appeared in the data. Although a distinct change of color intoblue were discernible in the measured data there is no evident proof that this cause a final print thatis more yellow. Other conclusions and results are to be read at the end of this composition.

Colorizing Grey Scale Images

The purpose of this thesis is to develop a working methodology to color a grey scale image. This thesis is based on approach of using a colored reference image. Coloring grey scale images has no exact solution till date and all available methods are based on approximation. This technique of using a color reference image for approximating color information in grey scale image is among most modern techniques.Method developed here in this paper is better than existing methods of approximation of color information addition in grey scale images in brightness, sharpness, color shade gradients and distribution of colors over objects.Color and grey scale images are analyzed for statistical and textural features. This analysis is done only on basis of luminance value in images. These features are then segmented and segments of color and grey scale images are mapped on basis of distances of segments from origin. Then chromatic values are transferred between these matched segments from color image to grey scale image.Technique proposed in this paper uses better mechanism of mapping clusters and mapping colors between segments, resulting in notable improvement in existing techniques in this category.