GB695773A - Improvements in or relating to x-ray apparatus - Google Patents

Abstract

695,773. X-ray apparatus. WESTING- HOUSE ELECTRIC INTERNATIONAL CO. Feb. 1, 1952 [March 22, 1951], No. 2733/52. Class 98 (i). The apparatus comprises an electronic image intensifier tube having a fluorescent screen, an electron optical system energized by light from the screen, means for projecting an electron image of the light-field of the screen to produce a contracted light-image on an output screen and an optical system for viewing the lightimage, wherein the optical system comprises a roof-mirror, a magnifying lens system, means for supporting the roof-mirror and lens system in position to project an image appearing on the output screen to one side of the axis along which the electron image is projected, and means for adjusting the roof-mirror and lens system to vary the angle of the rays reflected by the roofmirror relative to the axis of projection of the electron image. An X-ray tube below a patient-supporting table (not shown) produces an image on the input screen of an electronic image intensifier. The X-ray tube and image intensifier may be mounted to move along the table, which may be tiltable. A much brighter, but smaller image is formed at the output screen 9 of the image intensifier 5. A housing 6 enclosing the image intensifier 5 is apertured opposite screen 9 and supports a disc 13 having an annular groove in which a ring 15 is rotatable. Disc 13 is apertured to support a lens 14. A pair of mirrors 19 at right-angles are mounted on an axle 18 carried in brackets 17 on ring 15. A gear-wheel 21 fast with axle 18 is geared to a wheel 22 freely mounted on the axle and fast with a bracket 23 carrying a lens 25. The gearing is such that on moving bracket 23 through a given angle, mirrors 19 move through half that angle, so that an observer sees the image through lenses 14, 25 and by reflection by mirrors 19. The optical system is such that the image on screen 9, which is reversed laterally and vertically with respect to the original image on the input screen, is seen as an unreversed image equal or greater in size to the original image and of greater brightness. The whole system can be rotated about the axis of the intensifier, and the exit pupil of the optical system is large enough to enable the observer to view the image with both eyes. Clamping means may be included to hold the parts in any required position. Specification 662,569 is referred to.