ARNOLD GREENE
Engineering in Newton, MA

5024512, Jun 18, 1991

Feb 7, 1989

7/309007

Arnold H. Greene - Newton MA
Harold E. Holden - St. Johnsbury VT

American Photo Systems, Inc. - St. Johnsbury VT

G02B 2120, G02B 2702, G02B 2734

350514

A process for high resolution high accuracy photoreduction of radiographs, a rotatable photographic copy stand for the photoreduction process, and a high resolution high accuracy microfilm reader with built-in measuring capabilities are shown. The photoreduction process employs a camera with high precision optics, a high resolution copy film, and a first developing solution containing 0. 014 to 0. 025 moles per liter of a 3-pyrazolidone as the primary developing agent plus a lesser amount of a secondary developing agent, in a reversal process, to yield positive images having gamma values of 1. 00 to 1. 05. The copy stand has multiple workstations mounted on a rotatable frame, and several lightboxes. The microfilm reader employs high precision optics throughout, and possesses a variable magnification objective lens, a beam splitter, ultrawide-angle eyepieces, and a movable measuring reticle, the image of which is superimposed upon the image from the objective lens for accurate measurement of features shown on a film being examined. By means of the disclosed process and apparatus, industrial radiographs or other sorts of X-rays are photoreduced and later reenlarged for reexamination and measurement of selected features, with an overall dimensional accuracy of at least 99. 9%.

4849794, Jul 18, 1989

Jul 20, 1987

7/075594

Arnold H. Greene - Newton MA
Harold E. Holden - St. Johnsbury VT

Micro-Radiographs, Inc. - Natick MA

G03B 2762

355 75

A process for high resolution high accuracy photoreduction of radiographs, a rotatable photographic copy stand for the photoreduction process, and a high resolution high accuracy microfilm reader with built-in measuring capabilities are shown. The photoreduction process employs a camera with high precision optics, a high resolution copy film, and a first developing solution containing 0. 014 to 0. 025 moles per liter of a 3-pyrazolidone as the primary developing agent plus a lesser amount of a secondary developing agent, in a reversal process, to yield positive image having gamma values of 1. 00 to 1. 05. The copy stand has multiple workstations mounted on a rotatable frame, and several lightboxes. The microfilm reader employs high precision optics throughout, and possesses a variable magnification objective lens, a beam splitter, ultrawide-angle eyepieces, and a movable measuring reticle, the image of which is superimposed upon the image from the objective lens for accurate measurement of features shown on a film being examined. By means of the disclosed process and apparatus, industrial radiographs or other sorts of X-rays are photoreduced and later reenlarged for reexamination and measurement of selected features, with an overall dimensional accuracy of at least 99. 9%.