Unitary intensifying screen and radiographic element
US4865944A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 20, 1988 |
| Grant date | Sep 12, 1989 |
| Priority date | — |
| Expiry date | Jun 20, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03C5/16
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A unitary intensifying screen and radiographic element are disclosed comprised of adjacently coated silver halide emulsion and X radiation absorbing fluorescent layers. The fluorescent layer (a) is capable of attenuating at least 5 percent of a reference X radiation exposure produced by a Mo target tube operated at 28 kVp with a three phase power supply, wherein the reference X radiation exposure passes through 0.03 mm of Mo and 4.5 cm of poly(methyl methacrylate) to reach the fluorescent layer mounted 25 cm from a Mo anode of the target tube and attenuation is measured 50 cm beyond the fluorescent layer, (b) contains a phosphor which exhibits a conversion efficiency at least equal to that of calcium tungstate, (c) exhibits modulation transfer factors greater than those of reference curve A in FIG. 3, and (d) exhibits an optical density of less than 1.0. The emulsion and fluorescent layers are contiguously coated or optically coupled through a transmission medium transparent to latent image forming radiation and having a refractive index of at least 1.33, and the silver halide emulsion layer contains an agent for promoting the oxidation of silver atoms to silver ions to offset the …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.