With the advancement in microprocessors and nano-technologies, non-impact printing has transitioned from analog to digital and is migrating from monochrome to color. The digital color-printing offerings have extended from home and office up to the production- printing segment. Digital color printing technologies have continually evolved in an effort to meet the intense customer demand for lower price per page, greater reliability/image quality, and a broad range of applications. These advances could not have been made without the critical role that xerographic materials have played. Life extensions with the ability to achieve high toner transfer efficiency and clean-ability for photoreceptor and intermediate transfer belt has been an intense focus in this industry. The rapid expansion of chemical toner technologies has enabled new applications and offered new opportunities. This talk reviews the market trends in printing, the technological challenges of meeting the market requirements, and the material developments, which have supported the digital color printing advances.
Pigment dispersions are playing an increasingly important role in high performance inkjet inks. Colloidal stability of pigment particles can have a profound effect on print head and paper printing performance. Reliable and quick analytical methods to assess colloidal stability are essential in any development effort. Commonly accepted practice calls for aging the sample under accelerated conditions and then measuring the changes in particle size distribution. Widely applied particle sizing techniques require samples to be diluted. Dilution can disturb the system and the results may not reflect the concentrated state. In this report we explored the possibility of using an accelerated centrifugation method to evaluate colloidal stability without dilution. The instrument for this study is LUMiFuge® In this study, the colloidal stability of pigment dispersions as function of pH and ionic strength were successfully determined without dilution and aging. Particularly intriguing, the LUMiFuge method can discern the difference among samples that the traditional methods had failed. This manuscript will also discuss the limitation of LUMiFuge® Our study strongly indicated that this is an extremely sensitive method to evaluate colloidal stability of dispersions at their original concentration. When LUMiFuge® results are correlated to the performance of pigmented inkjet inks, it can serve as a valuable tool for both research development and quality control and assurance.
We've had digital revolutions in communications and computation, but not yet fabrication. Computers control machines that make computers, but a 10-billion-dollar chip fab still uses fundamentally analog materials. Biology provides an alternative model based on programmed assembly of molecular building blocks, offering the same kind of reliability thresholds that enable digital communications and computation. I will present research on fundamentally digital fabrication technologies that merge computation with construction, and illustrate their implications in both developed and developing countries through early access to prototype tools for personal fabrication.
Non-aqueous ink-jet inks and their long-time stability at different temperatures were studied using single-particle optical sensing (SPOS). Samples ground for the same period but having different amphiphilic polymer additives used for steric stabilization were prepared. SPOS characterizes the particle size distribution at the high end of the particle diameter (> 0.5 μm). In the aging at different temperatures, the high-end size distribution exhibited changes ascribed to sedimentation and aggregation. In the absence of aggregation, the decrease of the particle volume was identified as originating from sedimentation; the dependence on particle diameter and viscosity agreed with theoretical prediction. The aggregation appeared as a hump in the tail of the main peak. The hump was more clearly observed for inks aged at a higher temperature and having more loosely adsorbed polymer additives.
About that time of Nobel Prize 2000 in Chemistry for the discovery and development of conductive polymers, a group of organics called as organic semiconductors began to attract a great deal of attention for the electronic materials. Past three decades, organic electronic materials, namely “Organic Photoconductors, OPCs, achieved a great success as electrophotographic photoreceptors of copying machines and laser beam printers after many years' efforts. The deep understandings on the charge generation and transport as well as charge injection at the interface of organic layers in organic photoreceptors established the fundamentals of electronic processes in a wide range of organic materials, which are consisted of inherently insulating molecular assembly. Recently, on a flag of “Organic Electronics”, these materials are thrown into many electronic devices such as organic electroluminescent EL devices, and more recently, organic FET transistors, organic memories, and solid state organic solar cells. Especially, great efforts have been devoted to achieve paper-like displays or electronic papers, exploiting their advantages for large area, flexible devices.In this talk, the historical progresses of OPCs in past 30 years will be reviewed briefly and let us consider what we are now aiming at with organic electronic materials, which are generally said to be inferior to inorganic silicon semiconductors in their electrical properties, and find a scenario to an advanced imaging world drawn with organic electronics. If the time permits, our recently developed novel opto-electronic device combining an organic EL diode and organic photo-electrical conversion layer will be introduced.
Increasingly, digital photographers employ the thermal dye transfer system to produce their color hard copy prints. The Kodak Professional Ektatherm Xtralife™ three-color ribbon (donor) and receiver in Kodak's kiosk picture making system offers a convenient method for producing durable, long-lasting highquality prints from digital files. This paper will discuss the sensitivities of the Kodak Xtralife system to key environmental factors—light, temperature, relative humidity, and gaseous pollutants. Gathering data to characterize print sensitivity to temperature has proven to be a long process because of the incompatibility of the thermal dye transfer print's physical characteristics with the high end of the temperature range used in accelerated Arrhenius testing. However, reasonable data can be generated if the prints are tested at temperatures near or below the glass transition temperature of the receiver matrix.
Nanoscience by itself is to a large extent an imaging science where complex information about ultimately small pieces of matter is mapped into multi dimensional arrays. Nano-imaging goes far beyond microscopic projection images and has contributed to the evolution of mankind's scientific understanding which is continuously rolling over into technology. In this talk I will first use nano-imaging to explain some of the recent breakthroughs in nanoscience before I describe selected examples for the transfer of nano-science into nano-technology; All—of course—in the context of imaging. I will close with a rather personal outlook into future developments and long term visions.
In accelerated light fastness testing the display life environment is simulated by choosing defined constant humidity levels or by cycling between a dry/light and a humid/dark level. The humidity level is a factor that may cause dye diffusion effects on one hand and different degradation speed of the colorants on the other hand. The right choice of the humidity level is important for display life testing and display life predictions.In a group of typical inkjet media/ink combinations some exhibited a strong influence on the humidity cycling conditions whereas others showed little effect. As different colorants have a different sensitivity to humidity their relative ranking change when the test parameters change. This changes the colour balance of faded prints and affects the display life predictions drastically. The first fading colour, as well as the colour shift in image degradation are shown to be a function of the sample humidity during the light exposure.On the basis of light fastness measurements in humidity cycled system over several years the statistical variation for display life of a typical inkjet print has been determined which gives an indication about the experimental errors of a cycled system. A proposal for a dual humidity level test is made.
New electron transport materials having the following general structure shown in Figure 1 have been developed. We synthesized them and examined their properties. These compounds showed good compatibility to a polycarbonate and good solubility in common organic solvents. Electron transport properties of these compounds were investigated. Electron drift mobilities have been measured as a function of the concentration and electric field by the conventional time-of-flight technique. They showed nondispersive electron transport in composition films. The values of electron mobility ranged from 10−8 to 10−4 cm2/Vs as the molecular concentration was varied from 20 to 60 wt%.
Previous attempts to measure the thermal dark fade of inkjet prints by the Arrhenius method have been confounded by dye migration. When tests are carried out at a constant, absolute humidity equivalent to 50% relative humidity (RH) at 24°C (constant 13°C dew point), temperatures as high as 75°C can be utilized for many ink-media combinations without encountering significant dye migration. Concerns have been raised that these conditions might result in much lower levels of residual moisture in the imagebearing layers, and this in turn might affect the observed rates of density loss and/or yellow stain formation. In this paper, we compare the results for Arrhenius studies of inkjet photographic papers and inks that have been run under both constant 13°C dew point and constant 50% RH conditions. We also explore the interrelationship between temperature, dew point, and relative humidity over narrower ranges that might be found in an indoor home environment.