We use Optical Character Recognition (OCR) during our scanning and processing workflow to make the content of each page searchable. You can view the automatically generated text below as well as copy and paste individual pieces of text to quote in your own work.
Text recognition is never 100% accurate. Many parts of the scanned page may not be reflected in the OCR text output, including: images, page layout, certain fonts or handwriting.
1949
C-R-TuBE APPLICATIONS
79
and phototube have been used to look at the edge of each blade as it passes by. Fig. 13 shows the optical setup used. The sweep frequency on the oscillograph is synchronized with the repetition rate of the blades. The resultant patterns are shown in Fig. 14. The dips between patterns are due to the gaps between blades. The sensitivity here is equivalent to a magnification of 1000:1, about 100 of this magnification being accomplished optically, the other factor of 10 accomplished electronically in the oscillograph amplifier so that a deflection of one inch on the cathode-ray-tube screen is equivalent to Viooo inch on the razor blade. The pictures show a number of
BLADE STRIP,
Fig. 13 — Optical setup for razor-blade testing.
blades which are perfect and some blades which have nicks about 1/2oooth of an inch deep.
AUTOMATIC PRINTER ADJUSTMENT
One of the basic problems in the photofmishing industry is to obtain a properly exposed and developed set of prints from a widely varying series of negatives. This is usually accomplished by a hitor-miss system which is based solely upon the judgment of the printer in the darkroom. This precludes accurate duplication of results from one photofinisher to another. Some attempts have been made to use electronic exposure controls which automatically adjust at least the exposure for these widely varying negatives. The darkroom operator still has to select the proper grade of printing paper.
A suggested approach to this problem is to print each negative to