Sensitometry

Measurements involving continuous exposures are widely used to determine the radiation sensitivity of xerographic photoreceptors. While the technique has the very considerable advantage of experimental simplicity, it has several fundamental limitations. Of these, the most significant is that exposures of this kind do not correspond to those used in most copiers or printers. Another limitation is that the technique gives no information concerning the time required to discharge the photoreceptor, which is of considerable relevance. A 

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There are two aspects of resist sensitometry 1) the measuiement of resist response to radiation which involves measurements designed to determine the intrinsic radiation sensitivity of the materials from which the resist is constituted and 2) lithographic sensitivity which is a measure of the efficiency with which these radiochemical conversions can be expressed in relief image formation. 

Figure 15 Top Photographic latent image formation in undoped (left) and formate-doped and gold-sulfide sensitized AgBr crystals with the hole-scavenging step (center). Secondary reduction step by formyl radical (right). Bottom Sensitometry curves for gold-sulfide sensitized emulsions, undoped or formate-doped, and developed after 5 or 20 min (texp = 10 sec, development with aminophenol and ascorbic acid). The same absorbance is observed for a number of photons absorbed 5 or 10 times less, respectively, than in the undoped emulsion. (From Ref. 200.)...

From the fundamental standpoint, the primary concern in resist sensitometry is the measurement of resist response to radiation which involves... 

Conventional sensitometry is used to determine photographic sensitivity. Special sensitometers have been built which allow the photographic properties of emulsion coatings to be determined for exposures made under vacuum or a variety of atmospheres, pressures, and temperatures (13-15). 

In retrospect, this was another one of Upson s devious activities. The four-color Dylux, which the marketing people liked, offered a quick, and inexpensive four-color overlay system, which could have competed effectively with 3M s color overlay systems. The sensitometry, which we had developed, showed remarkable consistency only the black required a bit longer exposure to bring the color to full density. This was established by Dr. E. E. Grubb, of Photo Products, who had been asked to establish the performance of these films. The cyan was an excellent color match, and the red and yellows could be tuned close to the lithographic standards. Another company, with a more open-minded research management would no doubt have made a product out of all that. 

A. A. Pankratov, V. I. Derkach, T.M. Ivanova, and V. F. Barachevsky, Sensitometry of recording layers based on organic photofluorochromes, in Abstracts of II All-Union Conference on Formation of the Optical Image andMethods of Its Processing, p. 136 (1985) (Russ.). 

Figure 17 Sensitometry as a function of cycle number. The first cycle characteristics, Vdark, Vmidy and Verase correspond to the voltages obtained with no exposure (dark), exposure to one-half of the initial potential (mid), and those obtained following the erase exposure. The potentials obtained with the same exposures after 104 cycles are also shown. In this example, the photoreceptor fatigued with decreasing Vdark and increasing Verase These characteristics are often described as cycle-down and cycle-up.

The effects of the generation-layer fabrication variables on the sensitometry of a dual-layer photoreceptor prepared with bis(4-dimethylaminophenyl) squaraine (X = H in Appendix 2) have been extensively investigated by Law (1987). The charge acceptance, dark discharge, sensitivity, and the residual... 

Physicist and electrical engineer. Attended Universities of Nebraska and Rochester. Joined Eastman Kodak at Rochester, New York in December 1912. Appointed Director of the Camouflage Research Center in the Eastman Kodak Research Laboratories, serving as a Lieutenant USNR from March 1918 to February 1919. Became Superintendant in Charge of the Physics Department, Eastman Kodak from 1929. Noted for his research into sensitometry (film speed behaviour). This led to the establishment of film speed criterion which has been employed internationally - since 1934 by Eastman Kodak, from 1943 by the American Standards Association and from 1947 by the British Standards Institute. 

Figure 5.3, Relationship between exposure ( ) and developed silver density (D). The continuous curve illustrates the basic sensitometry obtained in negative-working systems. Increasing exposure results in increasing developed (optical) density (elemental silver or image dye in the case of colour systems). The dotted curve illustrates positive-working sensitometry, where increasing exposure results in decreasing developed density...

Physics of light acoustics holography photography computer graphics computer animation mathematics chemistry sensitometry mechanical engineering electronic engineering perception. 

Sensitometry Measurement of the sensitivity of various materials, especially photographic film, to fight. 

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