Latent image characterization

K. C. Hickman, S. M. Caspar, S. S. H. Naqvi, K. P. Bishop, J. R, McNeil, G. D. Tipton, B. R, Stallard, and B. L. Draper. Use of Diffraction From Latent Images to Improve Lithogrophy Control. Presented at the SPIE Technical Conference 1464 Symposium on I.C. Metrology, Inspection, and Process Control, San Jose, CA, 1991, Proc. SPIE. 1464, pp. 245-257, 1991. Another application is presented of scattering characterization and modeling from periodic structures for process control. 

Latent image fonnation involves the creation of free electron-hole pairs by the absorption of an image exposure and the displacement of these carriers by a field. Experimental techniques for characterizing these phenomena are of considerable importance to xerography. This section reviews experimental methods for measuring parameters that describe charge generation and transport phenomena. 

The description of a colloid should include particle size, mobility, charge and their distributions, charge/mass ratio, electrical conductivity of the media, concentration and mobility of ionic species, the extent of a double layer, particle-particle and particle-substrate interaction forces and complete interfacial analysis. The application of classical characterization methods to nonaqueous colloids is limited and, for this reason, the techniques best suited to these systems will be reviewed. Characteristic results obtained with nonaqueous dispersions will be summarized. Physical aspects, such as space charge effects and electrohydrodynamics, will receive special attention while the relationships between chemical and physical properties will not be addressed. An application of nonaqueous colloids, the electrophoretic development of latent images, will also be discussed. 

Different methods of kidney imaging have shown that Balkan nephropathy patients with chronic renal failure have symmetrically shrunken kidneys with smooth surface and no calcifications [90]. The time at which the shrinking occurs remains to be determined. While some authors suggest that the size of the kidneys remains normal in patients in the latent phase of the disease and with normal renal function, others report cases of shrunken kidneys in patients in an early phase with normal glomerular filtration rate, and it was even proposed that the disease was characterized with primarily small kidneys [98, 110, 112]. As ultrasound became a standard imaging method in the evaluation of kidney dimensions, several recent studies that used this method showed diminished kidney length and cortex width in members of Balkan nephropathy families with normal kidney function [113, 114]. Besides,... 

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