This report describes an outline of the Digital test chart No. 7, which has been published in the last April from The Imaging Society of Japan. In addition to the specifications, the development concept, production methods and verifications of image qualities were explained. No. 7 includes four kinds of digital images aiming for viewing on monitors and a silver halide print. Color reproduction introducing appearance models, sharpness and graininess are taken into account in the image processing. An unsharp masking technique was employed to enhance sharpness without unacceptable graininess deterioration. A sine wave chart was used to obtain spatial frequency responses in the scanning process, while frequency spectra of pictorial images are used to calculate the responses for the low resolution printer. Average delta E in the entire printer gamut is as small as 1.7 and high responses of more than 90% in visually important frequencies below 3 cycle/mm were achieved without significant increase in graininess. Related information can be obtained from the following Web : http://www.isj-imaging.org/announce/test_chart/list_test_chart.html
A physical model of hollow defects that focuses on the toner cohesion in a compressed toner layer and the balance of acting forces on the cohesion is proposed. From the model experiment of transfer process and the measurement of the rupture stress for toner samples with various shape and adhesion, the correlation between the hole area in hollow defects and the rupture stress of a toner layer is obtained. From this correlation the proposed model of hollow defects is validated. Forming condition of the hollow defects as to toner adhesion are presented from the physical model, and are validated by the adhesion measurement of pressed toner particles. The guides to reduce hollow defects based on the physical model are presented.
Block copolymers provide regular nanoscale microphase separation structures whose pattern size ranges typically several tens nanometers(meso-scales). How to control these structures and patterns is of particular importance from technological viewpoints because top-down (photolithography etc.) and bottom-up supramolecular assembly approaches typically do not reach such feature size. We introduce here our recent research activities to perform the structure and orientation controls of the meso-patterns formed by block copolymer thin films. The former describes the versatility of using mediating low-molecular-mass molecule to achieve highly ordered array structure in the monolayer systems. The latter part demonstrates that how light irradiation is powerful to control them both in the monolayer and spincast film systems.
Recent years, large amount of fine images and high-definition movies are delivered through the Internet, therefore the improvement of the transmission speed of the optical communication is in strong demand. The optical modulation is an essential technology that defines the information transmission capacity in the optical communication, and an organic electro-optic polymer attracts attention because of enabling super-high-speed modulation that exceeds 100 GHz with low power consumption. Recently, the electro-optic polymer that shows the performance of ten times more than the conventional material was reported, and the extension of the application field to the optical interconnection in the semiconductor integrated circuit as well as the high speed modulation. This report introduces the research trend in the electro-optic polymer that shows rapid progress mainly on the material development.
Block copolymers, liquid crystals and colloid crystals provide very promising photonic-crystal materials for non-linear optical devices that enable us to realize a ubiquitous society based on high-speed communication. They spontaneously form such highly ordered periodic structures as opals or bright blue wings of morphos. Deep understanding of the formation mechanism via self-assembly and also the technique of the structural control enables us to control the flow of light. Recently, we have developed the novel technique to fabricate photonic crystals in semi-dilute solutions of ultra-high-molecular-weight block copolymers. In this article, the formation mechanism of our photonic crystals in the solution is reviewed. It is also demonstrated that because polymers are soft the photonic materials possess tunability of the periods and the morphologies which can be applied to non-linear optical devices.
Fabrication and characteristics of organic light emitting diodes (OLEDs) and organic photodetectors (OPDs) have been discussed for optical signal transmission. Emission properties of polymeric light-emitting diodes (PLEDs) utilizing poly(9, 9-alkylfluorene) (PFO) derivatives have been investigated. 100MHz signal has been created by direct operation of the PLEDs and PFO based OPDs has been demonstrated for receiving optical signal up to 80MHz. Optical signals with moving pictures have been successfully transmitted by the PLEDs with polymeric optical fiber.
Monodispersed micro-particles have an intrinsic capability to self-assemble the face-centered cubic (fcc) lattice structures on the substrate surface from the suspension media. Such highly ordered 3-D architectures of colloidal particles are called as the colloidal crystals(CCs). The CC structures have received tremendous interests as one of the alternative and facile fabrication technique of photonic crystals(PCs). A brief review of recent research progress in the use of CC as PCs is described. This review highlights not only interesting precedents of the CC researches, but also a new potential utility for flexible polymer CC lasers.