Plate imagers

Hare DE, Rhea ST, Dlott DD, D Amato RJ, Lewis TE. 1998. Pulse duration dependence of lithographic printing plate imaging by near-infrared lasers. J Imag Soc Technol 42 90 97. 

One very important device is the plate reader, which can be rate limiting in HTS. Most laboratories use multimodal readers that can detect various forms of fluorescence as well as luminescence and absorbance. The traditional readers are photomultiplier-based devices that usually read from one well to the next. This process can take considerable time for 384-well and higher-density plates. A more desirable HTS reader type images the entire plate with a charge-coupled device (CCD) camera. The latter device is usually a faster reader for 384-well and higher-density plates. Imagers can capture significant cross talk from one well to another, but with proper set up, they can produce data of equal quality. 

Other assays are being explored in HTS platforms to identify potential inhibitors of invasion, for example, compounds that affect the shape or morphology of cells or their ability to generate invadopodia. Quintavalle et al. recently described such a method initially using Src-transformed NIH 3T3 fibroblasts grown on 384-well optical plates. Imaging of cellular and nuclear morphology combined with phalloidin-stained F-actin was used to discriminate compounds which reduced (or enhanced) the number of... 

A second type of image-plate detector employs gadolinium oxide, which absorbs a neutron and emits a gamma ray, which in turn exposes the image plate. Image plates have higher spatial resolution but lower efficiency than multiwire detectors. 

The sensitivity of both vidicons and diode arrays can be enhanced using a microchannel plate image intensifier. For example, Tracor Northern in their IDARSS system have used a Genii microchannel plate inverter intensifier, fiber-optically coupled to a Reticon diode array. With such a system, single photoelectron sensitivity, i.e. one count per photon, can be... 

Ion detectors can be divided into two classes. Some detectors are made to count ions of a single mass at a time and therefore they detect the arrival of all ions sequentially at one point (point ion collectors). Others detectors, such as photographic plates, image current detectors or array detectors, have the ability to count multiple masses and detect the arrival of all ions simultaneously along a plane (array collectors). 

Fig. 4 Reprinted from [96], (a) Schematics of the confocal rheoscope of the Edinburgh group [96]. The top arrow marks translation of the rheometer head to adjust the geometry gap, the horizontal arrow indicates translation of the arm supporting the objective to image at different radial positions r. (b) Close up of the central part of the rheoscope, similar to the cone-plate imaging system of Derks [111] except that in the latter the lower plate can also be rotated, while in the former the microscope objective radial position r can be varied, (c) Gap profile of a 1° cone-plate geometry, measured in the confocal rheoscope with fluorescent particles coated on both surfaces...

However, the ink as actually printed on a lithographic press is an emulsion which may contain as little as 20% or as much as 50% of fountain solution as a finely dispersed internal phase. It is the rheology of this ink emulsion which determines the configuration of the printed areas and the faithfulness of the reproduction of the plate image. 

Figure 10. GATF Printed Star Targets and Dot Resolution Ratings for Inks A-l and C-4 (original plate image in center) 36X-...

Figure 1. The effect of near field stray radiation on the spectral line profile (546-nm Hg emission line). The detector was a microchannel-plate image intensified diode array (Reticon model RL-5I2SF, Princeton Instruments, Inc. model IRY-512). Key a, full line profile b, upper half (FWHM)ofline andc, lower portion of line, 0-10% relative emission...

MicroChannel plate image intensified-coupled silicon... 

Blinding of lithographic plates n. Loss of ink-receptivity in the plates image areas. 

Slur sl9r [obs. E dialect slur thin mud, fr. ME sloor, akin to MHGr slier mud] (1609) n. A condition caused by slippage at the moment of impression between any two of the following paper, printing plate, image carrier, or blanket. 

Wilson, Daniel G. Lithography Primer. 3d ed. Pittsburgh GATF Press, 2005. An illustrated overview of each step in the lithographic printing process. Includes chapters on topics such as plate imaging, inks, and papers. 

Fig. 3.14 Two images of a thin i melt-cast film of polycaprolactone. As in Fig. 3.13, the region is 200 x 250/zm, the left-hand image was taken under crossed polars and for the right-hand image, a first order red plate was also used. The spherulites in this material are much less regular, and some show colors under crossed polars. The first order red plate image can still show that the spherulites are negatively birefringent.

Dilmanian FA, Weber DA, Coderre JA, Joel DD, Shi K-C, Meinken GE, Som P, Tang Y-N, Volkow ND, Yee C, BriU AB, Watanabe M, Inuzuka E, Oba K, Gerson R, lida H, Hiruma A. A high-resolution SPECT system based on a microchannel-plate imager. IEEE Trans Nucl Sci 1990 37 687-695. 

Fig.6.38. Optical multichannel analyzer with microchannel-plate image intensifier...

---