Dislocations and donor centers have important functions in the optimization of the performance of silver halide emulsion grains. The basic properties of dislocations relevant to photographic sensitivity together with the experimental observations which established these properties are reviewed in this paper. Internal latent image and internal particles of photolytic silver are formed during exposure of AgCl and AgBr crystals, sensitized with Ag₂O and Ag₂ donor centers, by the separation of Ag atoms along the dislocation lines. The surface sites of termination of dislocations have enhanced reactivity compared with low-energy surfaces. Dissolution, chemical sensitization, and the initiation of surface chemical development occur at higher rates at these sites. These properties led to the concept of the dislocation sensitivity center. Development centers are formed by the combination of Ag atoms with Ag₂ latent image growth nucleus precursors at the surfaces of dislocation sensitivity centers. The formation of Ag₂ molecules along the subsurface dislocation of the center has to be minimized. Microcrystals of AgCl and AgBr with dislocations introduced during nucleation and initial growth pass into solution at a high rate during a short period of ripening leaving dislocation-free growth nuclei. For stable distributions of dislocations in microcrystals, concentration gradients of halide ions have to be established in heterogeneous crystals. Controlled densities of dislocations are introduced to reduce the elastic strains associated with steep concentration gradients. In double-structure grains with a higher iodide shell and in triple-structure grains with a higher iodide narrow zone, the concentration gradients can be established by the addition of a fine dispersion of Ag(Br,I) particles or of an iodide ion releasing compound. The resulting dislocation distributions are stable because of the immobility of the iodide ions in the crystal. The mechanisms involved in the creation of dislocations in structured tabular microcrystals are discussed.

Photoluminescence (10 to 90 K) processes resulting from recombination centers emitting in the region of 550 nm in <III> AgBr (88%)–I (12%) tabular grains are studied. Stacking faults, dislocation defects, or double-twin planes are present in these microcrystallites. The greater the number and kind of iodide defects, the higher the low-temperature fluorescence quantum efficiency. The second-derivative photoluminescence presents additional information of competing emitting Ag°3 R-type centers emitting in the region of 562 to 571 nm. The photophysical processes leading to photoluminescent centers relate to emulsionmaking conditions involving iodide clustering, not AgI phases. It is the differences of ΔE of the rate-determining step that influence the quantum efficiency of fluorescence in the various low-temperature regions: 0.0009 and 0.0007 eV below 30 K, and 0.065 and 0.055 eV in the 50 to 70 K region for minimal defect and S-defect tabular grains. The 0.065 and 0.055 eV are shallow electron traps beneath the conduction band. The βAgI hexagonal fine grains of 36 Å diameter were assigned to the quantum particle (confinement) fluorescence at 424 nm and a βAgI large-grain 448-nm Stokes-shifted emission; γAgBr emission for microcrystals is 455 nm. The quantum model, using effective masses, describes Wannier excitons of I_m⁻ⁿ in AgBr. The structure of clusters seems to consist of bent, 3-at. iodide structures (AgI₃)_n. Also, clusters consist of 3-at. linear configurations, formed during the emulsion-making process, and emitting radiation in the region of 540 and 590 nm with cluster diameters of 12 to 14 Å, respectively. These clusters (AgI ₃)n or (+AgI⁻−I₂)_n interact closely with the AgBr point defect lattice. Recombination emission from these clusters is studied. Microcrystals containing double-twin planes have an additional excitation band coincident with the emission band at 461.5 nm (2.6860 eV), the exciton localization at the twin plane. The higher energy excitation is shown at 461.0 nm (2.6889 eV), the assigned indirect exciton band gap. Splitting of 2.9 MeV or hole-limiting binding energy to the iodide anion located at the twin plane provides an estimate of the hole lifetime of 1.41 × 10⁻¹⁰ s at 10 K. The hole and electron are capable of traversing the doublet-win plane separation of 93.3 and 100 Å.

In this paper, a linear CCD was used to detect the whole physical development process directly on the silver halide direct printing plate. The activity of the physical developing nuclei was also detected, and the influence of the ingredients of the working solution such as developer hydroquinone, silver complexing agent, and the environment such as pH, was evaluated. It was proved that the CCD technique was very successful in detecting the physical development process in the diffusion transfer reversal (DTR) system.

An overview on the utility of 2-nitrobenzyl sulfonate photoacid generators (PAG) in chemically amplified deep UV (248 nm) photoresists is presented. This article will detail how structural changes in photoacid generators affect properties such as quantum yield, thermal stability, etc., and will also illustrate how these properties influence the lithographic characteristics of photoresist formulations.

Based on the variational methods, design equations for coating dies that are widely used in the photographic emulsion coating industries have been obtained in analytical forms, and the key dimensionless parameters that affect the coating weight uniformity have been identified. The effects on coating weight uniformity of a tapered angle in the die distribution chamber have been investigated and its performance is compared with nontapered dies. The coating weight uniformity index has been defined in terms of the pressure ratio in the distribution chamber and sample calculations have been made for each die to show the effects of die internal dimensions on coating weight uniformity indexes. Other factors that could also affect the coating weight uniformity, such as the precision of machining of the die slot opening, a distorted wetting line on the lower pressure side coating bead meniscus, and turbulent eddies in the vacuum box, have been discussed briefly.

This paper describes an optical method for improved drop velocity stability measurement to be used in continuous ink jet printing applications. Stable drop formation is demanded in continuous ink jet printing and it is normally achieved by introducing mechanical vibrations from a piezoelectric crystal onto the jet emerging from a nozzle. The method in use today to obtain information about the stability of drop velocity is to view the drops in stroboscopic light. This method does not provide quantified information about the level of drop velocity stability and the roughness of the method makes comparison between different levels of stability subjective and hence difficult. In our method we illuminate the drop train with a continuous HeNe-laser to create a shadow image of the drops. This image is magnified through a microscope and projected onto the light sensitive area of a PIN photodiode-based detector the output of which is sampled by a digitizing oscilloscope. The sampled data is used to calculate the standard deviation of time between drops and this value is used as a measure of drop velocity stability. Our method is primarily developed to measure the stability of drop velocity of drops with a diameter of 15 mm at crystal excitation frequencies in the interval of 800 to 1400 kHz. However, the set-up can easily measure drop velocity stability for different sizes of drops by simply changing the magnification of the microscope. Measurements with our method show that an increased excitation signal amplitude will result in a higher level of stability. The drop velocity is to a great extent decreased by air resistance as the drops travel. The presence of good and poor stimulation frequencies for nozzle systems is shown, and the frequencies are indicated by low and high levels of standard deviation for time between drops.

Toner motion is controlled by electric force, adhesion force, mechanical force, and so on, in the electrophotographic printing process. Adhesion force is an important force. Adhesion force in the absence of electrostatic force is estimated by electric field forced toner jumping. Toner is sprayed on one of a pair of electrodes that are spaced parallel to each other. Voltage increasing at a constant rate is applied to the electrode, and toner jumping starts at the voltage where electric force overcomes adhesion and gravitation forces. From the toner jumping voltage, adhesion force is estimated. Toner diameter, substrate and toner application method dependencies are obtained.

A new coordinate system for hyperdimensional computer graphics called parallel volume coordinates is developed. Parallel axis, parallel plane, and parallel volume coordinates are compared using the representations of points, lines, hyperplanes, and hypervolumes. Coordinate dimension is distinguished from parametric dimension. A unique correspondence property for each of the three parallel coordinate systems is characterized, illustrated, and proved.