The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 12, 1991
Filed:
Oct. 16, 1989
Robert J Vagi, Broadview Heights, OH (US);
Leonard F Plut, Concord Township, Summit County, OH (US);
David L Leong, Northfield, OH (US);
Picker International, Inc., Highland Heights, OH (US);
Abstract
A patient (12) is irradiated with x-rays (10) from an x-ray tube (A). X-rays that have passed through a region of interest of the patient are converted to a light image by a phosphor screen (14) on the dome shaped input face (16) of an image intensifier (B). The dome shaped input face causes the output optical image (20) of the image intensifier to be distorted with pin cushion distortion. The sweep pattern of the electron beam of a video pick up tube (24) of a video camera (C) is controlled by deflection plates (26a, 26b, 26c, 26d). A sweep control circuit (D) alters the sweep pattern such that electronic image representations generated by the video camera are distorted in a manner that is complementary to and cancels the image intensifier tube distortion. In this manner, the two distortions cancel and a man-readable image (28) displayed on a video monitor (22) is substantially distortion-free. The sweep control circuit alters conventional vertical sweep control voltage ramps (V) and horizontal control voltage ramps (H) by adding third order, parabolic terms: