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.

Utvärdering av kvalité och dess behov inom förprovtryck

It always has been a need for the abiltiy to create color proofs. When an error occurs late in the production process, itis allways complicated and difficult to correct the error. In this project, digital proofs been made and discussions havebeen held with several people in the printing industry, in order to examine how well excisting digital proofs, meet thedemand of the market. And how close the digital proofs can come to the actual printsheat from the press. The study hasbeen shown that the one thing that has had the most influence on the outcome for the quality of a digital proof, is theprintshop operator’s knowledge about color management and proofing systems. Many advertising agencies in the graphicindustry think rasterised proofs are not necessesary and expensive. Therefor they prefer a cheaper alternative, whichdoesn’t show colors as well as the rasterised proof, but well enough to be content with it. There are a good awarenessconcerning lack of communication between printshop, reproduction and advertising agency. Advertising agencies thinkthat printshop rarely listen to what they have to say, while the printshop think that the advertising agency doesn’t understandwhat they are trying to tell them. The outcome of the printed proofs in this study can’t be representive for howgood digital proofs are conducted in regular basis in the industry. The divergence between the print press sheat and thedigital proof that was made was bigger than expected. This shows that implementation of ICC profiles in a color managementflow, not alone is the answer to making perfect digital proofs. There are so many other issues that has to be examined,like color management software, measure tools and correct color management module. In order to make a perfectproof, you have to look at the whole picture. In the end, the human eye finally has the last word on wheather theproof is good or not.

ICC-profilers funktionalitet vid byte av tryckfärgskvalitet

This degree theme work aims to evaluate the present ICC-profile and printing ink of Dalarnas Tidningar AB. The companyhas changed printing ink quality and wants to evaluate how the present ICC-profile work with the new printingink. Four different ICC-profiles were included in the comparison.One test printing was accomplished with two different separations. Two new ICC-profile was created, as a comparingmaterial. An densitometer was used to measure the technical parameters of the printing. IT8-charts and RGB-chartswas measured with spectrophotometer. La*b*-values, CMYK-values, graybalance curves, color deflections and colorgamuts was compared on screen and on the printed material.Materials from an earlier testprinting and evalution, made by Stora Enso Kvarnsveden AB 2003, was used to evaluatethe function of Dalarnas Tidningar AB´s ICC-profile with the present printing ink quality. The IT8-chart from todaystestprinting was oppened in a program for textediting to have access to La*b*- and CMYK values. The values from theearlier testprinting was supplied from Stora Enso Kvarnsveden AB.The result of this work shows that the ICC-profile from the company, compared with de other profiles, reproduce darkershadow regions which can make loss of details. An higher saturation is recieved in the red and yellow area while thegreen and blue area lose its intensity. The profile gave images which are some contrastless and with a flat reproduction.Today printing ink quality gives more saturation and intensity in the yellow and blue area compared with former printingink. The dark tone reproduces with decreased luminance, however.

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.

Processanalys vid Color Print Sweden AB med fokusering på prepressavdelningen

This thesis work has introduced process orientation at the printing company Color Print Sweden AB. The outcome ofthis work is a survey of the work flow at the prepress department. To visualise the production process at the companya comprehensive mapping of the main process, order-to-delivery, has been made. The work has detected a couple ofcritical elements in the existing process. These elements are the following: initial check of material delivered to the prepressdepartment as well as the control made of the plotter print-out, digital test print and plate. To guarantee the qualityof the prints it is very important that the work made in the prepress department is optimized. This survey can thereforebe used as a basis for continuous improvement in the processes at Color Print Sweden AB. This work has alsoresulted in a template that Color Print Sweden AB can use to design routine descriptions to ensure that specific worktasks are performed the right way by everyone and all the time.

Redesign av Vagabonds guideboksserieThe travelguides of Vagabond - Redesign

Todays travel trends go towards independence and self planning. If you need advice or help when performing your trip, there are several different series of guidebooks on the market and one of these series comes from the travel magazine Vagabond. This degree project concerns the redesigning of the travelguides of Vagabond, or to be precise: their cityguide over Istanbul. The purpose of the new design is to assure the resemblance between the guidebook and the magazine, as wanted by the Art Director of Vagabond Angelica Zander.Prior to the redesigning process preliminary studies that make up the fundamental ideas were made. Three other big titles of guidebooks on the market were analyzed, and in addition a great deal of focus – considering the final purpose – was put on the concept of magazine design. Some color psychology has also been studied to make out what a difference color makes in printed media and what power color can contribute with, when delivering the message. Finally redesign as a concept has been investigated to clarify why the way of expression should be renewed from time to time.The result is presented as spread examples from the cityguide over Istanbul. The new design is applied on the existing content and the result is supposed to appear as a miniature magazine.

Color Segmentation using LVQ-Learning Vector Quantization

This thesis aims to present a color segmentation approach for traffic sign recognition based on LVQ neural networks. The RGB images were converted into HSV color space, and segmented using LVQ depending on the hue and saturation values of each pixel in the HSV color space. LVQ neural network was used to segment red, blue and yellow colors on the road and traffic signs to detect and recognize them. LVQ was effectively applied to 536 sampled images taken from different countries in different conditions with 89% accuracy and the execution time of each image among 31 images was calculated in between 0.726sec to 0.844sec. The method was tested in different environmental conditions and LVQ showed its capacity to reasonably segment color despite remarkable illumination differences. The results showed high robustness.

Buried screen-printed contacts for silicon solar cells

A Simple way to improve solar cell efficiency is to enhance the absorption of light and reduce the shading losses. One of the main objectives for the photovoltaic roadmap is the reduction of metalized area on the front side of solar cell by fin lines. Industrial solar cell production uses screen-printing of metal pastes with a limit in line width of 70-80 μm. This paper will show a combination of the technique of laser grooved buried contact (LGBC) and Screen-printing is able to improve in fine lines and higher aspect ratio. Laser grooving is a technique to bury the contact into the surface of silicon wafer. Metallization is normally done with electroless or electrolytic plating method, which a high cost. To decrease the relative cost, more complex manufacturing process was needed, therefore in this project the standard process of buried contact solar cells has been optimized in order to gain a laser grooved buried contact solar cell concept with less processing steps. The laser scribing process is set at the first step on raw mono-crystalline silicon wafer. And then the texturing etch; phosphorus diffusion and SiNx passivation process was needed once. While simultaneously optimizing the laser scribing process did to get better results on screen-printing process with fewer difficulties to fill the laser groove. This project has been done to make the whole production of buried contact solar cell with fewer steps and could present a cost effective opportunity to solar cell industries.

Color detection and segmentation for road and traffic signs

This paper aims to present three new methods for color detection and segmentation of road signs. The images are taken by a digital camera mounted in a car. The RGB images are converted into IHLS color space, and new methods are applied to extract the colors of the road signs under consideration. The methods are tested on hundreds of outdoor images in different light conditions, and they show high robustness. This project is part of the research taking place in Dalarna University / Sweden in the field of the ITS.