US1838537A - Process and apparatus of radioscopy, radiography, and radiocinematography - Google Patents

Description

Dec. 29, 1931. DAUVlLLIER I 1,838,537

PROCESS AND APPARATUS 0F RADIOSCOPY, RADIOGRAPHY, AND RADIOCINEMATOGRAPHY Filed Jan. 51, 1928 2 Sheets-Sheet 1 flZezazzdz-e Jazzy z'ZZz'ez Dec. 29, 1931; DAUVlLLlER 1,838,537"

PROCESS AND APPARATUS O F RADIO SCOPY, RADIOGRAPHY, AND RADIOGINEMATOGRAPHY Filed Jan. 31, 1928 2 Sheets-Sheet 2 Eyes.

HII H FM anocwtoz flzexander Jaw a'z'Z Z is?" Patented Dec. 29, 193E ALEXANDRE DAUVILLIER, or rams, manor.

rnocnss AND APPARATUS or RADIOSCOPY, RADIOGRAPHY, AND 'RADIOGINEMATOG- RAPHY.

Application filed January 31, 1928, Serial No..250,942, and in France February 2, 1927.

The present invention is adapted to obviate the inconveniences presented, heretofore, by the known processes and apparatus of radiodiagnosis, which are: the danger due to X rays, the small luminosity of radioscopic images,the limitation of the field of investigation of these processes, and the blurring due to secondary radiation. he invention consists in receiving the radiologie shadow, no longer on a luminescent screen or a radiographic film as heretofore, but on a single large radioelectric detector, such as an ionization chamber or a'surface of selenium, byexploring the field of radiation by means of a suitable movable diaphragm, selecting therein at every instant, without loss of time, a slender beam of X rays, of invaria-' ble size. The corresponding electric current, issued from the radiodetector, is suitably. am plified and modulates the instantaneous luminosity of a source of'light withoutinertia, such as a discharge lamp, or a light valve of the Kerrs type for instance. This source illuminates a movable diaphragm receiving synchronous movements in phase with those of the analyzing diaphragm owing to a me chanical connection. The latter appears as a continuous and animated image as soon as the exploration and synthesis are repeated at least ten times per second.

The accompanying drawings illustrate, by Way of example, two forms of carrying the invention into practice. 1

ig. 1 shows a diagrammatic view of the first form; Fig.2 represents the movable dia* phragm; Fig. 3 shows a fragmentary diagrammatic view of the second form.

The X-raytube 1 illuminates the subject 2 through the fixed diaphragm 3 and the movable diaphragm 4 which allows the passage, through the orifice 5, of the slender beam 6. The latter strikes upon the radioelectric, detector 7 which is here, for example, an ionization'chamber. This chamber is composed of high continuous potential by the source of 'potential 8. It is provided with a partition or cover 9 through which can pass the X rays. Oneaar moreinner insulated electrodes 10 rotected by a guard ring 11 collect the lone a box 7 of conducting material brought to a nated .and replaced-by formed along the beam 6. Theseelectrodes are covered with a deposit, of lead for instance, obtained by the Schoops process or any other process, increasing their electronic emission. The chamber may contain a heavy, compressed and dried gas. plied can be suflicientlyhigh for producing the ionization by shock. The current produced flows through an ohmic resistance ora kenotron 12 and the difference of potential produced is applied on any usual amplifier, which may be 'a direct current vacuum tube amplifier, the modulation. grid of which is electrostatically protected and the stages of which are connected by resistances and-coun-' tel-batteries. The difl'erence of potential 13 is applied to the terminals of a multiple Kerr condenser 14 arranged between a polarizing,

nicol and an analyzing nicol V which are crossed. The light issues from a lamp 17 arranged at the focus of an optical condenser 18. The parallel light beam modulated by the difference of potential 13 passes through the orifice 19 diametrically opposite the orifice 5. It is received by the objective 20 and proJected at 21 upon the screen 22.

Fig. 2 shows a diaphragmfor analyzing the radiologicshadow on one hand and for reconstituting the optical image on the other hand. It is a opaque to X rays and to light, perforated with two symmetrical diametrically opposite Nipkow spirals. The first one has n holes (1 to n) closed for instance by means of black paper. The secondone has also 91. holes (1 to n) closed by plugs made ofoglass containing lead, which can also consist of large lenses replacing the objective 20. This disc is moved by the motor 26 at the minimum speed of 600 revolutions per minute (10 complete images per second) in the case of radioscopy and of radiocinematography. I

he form of carrying the invention into practice as shown in Fig.1 ismore particularly adapted for being used for radloscopy. On the contrary, the form shown by Fig. 3 is intended tobe used for radiography andradiocinematography. The said form differs The tension apfrom thefirst in that the screen 22 is elimia -fi1m, 23 supported 24 and 25.

by the reels For obtaining radiography, the film 23 is immobilized in the neighborhood of the diaphragm 4 or arranged in the image plane of the objective 20. For obtaining cinema, this film is un wound by the reels 24 and 25 driven by the motor 26, so as to be immobilized during each complete rotation and rapidly displaced to the extent of one image at each revolutlon.

As shown in the fragmentary diagram, Fig. 3, this is accom lished by well known means comprising a eneva gear a driven by the finger or tooth b of the drum a, mounted on the shaft of the motor 26. The Geneva oscillating or translation movements, analyzing the image according to any trajectory, with uniform or variable speed of exploration, whilst remaining within the scope of the invention. Y I

What I claim as my invention and desire to secure by Letters Patent is 1. In a radiologic process the steps which consist in producing a slender beam of X rays; in exploring a subject by means of the said slender beam, in using the said slender beam after passing through the said subject for modulating an electric current in using the said electric current for modulating the instantaneous luminosity of a source of light, in selecting a beam of the said source of light, and imparting to the said beam synchronous movements in phase with those of the slender beam of X rays.

2. Apparatus for carrying out the process as claimed in claim 1, which comprises in combination a source of X rays, means for selecting at every instant a slender beam of X rays the size of which is invariable, means for exploring a subject by the said slender beam and selecting a beam of light, a radioelectric detector for receiving the said slender beam after passing through the said subject, and for transforming the variations thereof into electrical variations, a source of light, means for modulating the instantaneous luminosity of the said source of light according to the said electrical variations, said means for selecting a beam of light, also im parting to the same synchronous movements in phase with those of the slender beam of X rays, and a screen for receiving the beam of light.

3. Apparatus for carrying out the process as claimed in claim 1, which comprises in combination a source of X rays, a source of light, a movable diaphragm adapted to select,

at every instant, a slender beam of X rays the size of which is invariable, to explore a subject by the said slender beam, to select a beam of light, and to impart to the same synchronous movements in phase with those of the slender beam of X rays, a radioelectric detector for receiving the said slender beam after passing through the said subject, and for transforming the variations of said beam into electrical variations, means for modulating the instantaneous luminosity of the said source of light according to the said electrical variations, and a screen for receiving the beam' of light.

In testimony whereof I have signed my name to this specification.

ALEXANDRE DAUVILLIER.

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