US1922823A - Method and means for marking radiographs - Google Patents

Description

Aug. 15, 1933. H. s. SAWFORD METHOD AND MEANS FOR MARKING RADIOGRAPHS Filed Dec. 8, 1930 2 Sheets-Sheet 1 IN VEN TOR l/aro/d 8. San fora BY Qwaaa M A TTORNEYS Aug. 15, 1933.

H. S. SAWFORD METHOD AND MEANS FOR MARKING RADIOGRAPHS Filed Dec;. 8, 1950 2 Sheets-Sheet 2 DATE No COMPANY M NAME Harv/d 8 Saw/fora.

A ITORNEYS Patented Augil5, 1933 METHQD AND MEANS FOR MARKING RADIOGRAPHS Harold S. Sawford, Ozone Park, N. Y.

Application December 8, 1930. Serial No. 500,826

9 Claims.

This invention relates to a method and means of marking radiographs, and has for an object to provide complete identifying data directly on a small marginal portion of the radiograph plate or film. (The terms plate and film are used synonymously herein.)

It has been a practice in the past to employ a metallic stencil marker placed outside the cassette for making a mark directly on the plate, the metallic stencil being to a certain extent opaque to Roentgen rays. This practice has never proved very satisfactory for several reasons; The marking stencil on account of its large size was apt tobe partly covered by the object or part radiographed, so that the identifying marks were either too dark or too light or both, and were difficult to decipher. Furthermore, the amount of radiation employed varies greatly in making radiographs of different parts of the body, very light exposures being used for parts such as fingers, and very heavy-exposures for spines, etc. Since the opaqueness of the metallic stencil to Roentgen rays was relied on entirely for controlling the application of the I mark to the plate, and since the penetration of the rays through the metallic part of the'stencil varied greatly with. the lightness or heaviness of the exposure, the kind of mark secured was very uncertain. The stencil was necessarily located at the outer side of the first intensifying screen, which screen produced actinic raysin all areas exposed to any Roentgen rays and subjected the plate to the full effect of such actinic rays. The distance ofthe stencil from the plate also, mitigated against clear marking because of second.- ary radiation. 7 a The information whichcould be, secured by the useof such a stencil was very meager, consisting generally of nothing more than an identifying series of letters or number, so that the plate could only be actually identified through recourse to an index. As a consequence, it has been the more common practice to merely paste a paper label on r the plate, after the same has been developed. This practice, however, involves the necessity of carefully indexing the plates before they are developed, sothatthe correct label may be applied to each film Ithas the further drawback that the labels are apt to become detached or to be torn or obliterated when the plates are handled. r

To the end that a compact,. complete and clear identifying legend may he applied at the exposure of the plate,'I have contrived a means for interposing a screen opaque to actinic rays between the plate and the intensifying screen at one side of the plate in the area to be marked, and a label generally transparent to actinic rays between the plate and the intensifying screen at the opposite side of the plate in the same area,

with the desired information marked on the label in the ink opaque to ac'tinic rays. By this mans the actinic rays produced by the action of the Roentgen rays on the'first intensify- 5 ing screen in the marking area may be prevent ed by the screen from reaching the film in that area, while the Roentgen rays which pass on through have relatively little elfect upon the film leaving it photographically active. When these penetrating Roentgen rays reach the second intensifying, screen, the actinic rays produced come back through the label except in the marked areas. As a result of this arrangement, only the areas of the plate in registration with unmarked areas ofthe label'are exposed at all to the action of actinic rays, and since the label may lie directly in contact with the plate the marking is very clear. The label is 7 preferably made of paper highly transparent to actinic rays, so that clear results are obtained even with light exposure.

Alternatively the label may be positioned at the side of thefilm toward the source of Roentgen rays, and the screen opaque to actinic rays may be located at the opposite side of the film. The label then prevents the passage through to the film of any actinic rays in the symbol areas, while the screen prevents the reflection back of any actinic rays from the lower intensifying screen onto any portion of the marking area.

In a preferred form of the'invention the label and the mark protecting screen are made unitary, consisting of a single sheet of paper having one half of its area printed in solid black and the other half left white, with the exception of certain printed legends, and this sheet is adapted to be folded about its center to embrace a margin of the plate.

Other objects and advantages will hereinafter appear.

In the drawings forming part of this specification:

Figure l is a sectional elev'ationof acassette having a plate and a marker secured therein; Figure 2 is a perspective view of the marker employed in Figure 1;

Figure 3 is a back view of unfolded;

Figure 4 is a face view of the unfolded marker the marker shown showing the" screen area thereof printed in black;

Figure is an elevational view, partly broken away, of a film or plate having the marker applied thereto;

Figure 6 is a fragmentary, edge view on a larger scale than the other figures, showing the marker applied to the film or plate; and

Figure '7 is a plan view of an intensifying screen employed in accordance with one method of practicing the invention.

The cassette comprises a ring frame 1, a cover 2 preferably of sheet aluminum or other suitable strong material transparent to Roentgen rays, a sheet of black paper 3 opaque to actinic rays, and a fluorescent intensifying screen 4 applied to the under side of the sheet 3. A plate 5 having coatings 6 and 7 of a photographical- 1y active emulsion applied to the opposite faces thereof is placed against the screen 4 with a foldable marker 8 embracing a margin thereof. The cassette also includes a retaining plate 9 which carries a felt backing 10. A second intensifying screen 11 of fluorescent material is carried by the felt backing 10. The retaining plate 9 is held to the ring frame 1 to secure the photographic plate and the marker in place by means of a clamping latch 12 pivoted on the back of the retaining plate. The source of Roentgen rays is located above the cassette as the same is illustrated in Figure 1. The marker 8 consists of a sheet of paper having an easy fold line 13 along the longitudinal center thereof provided, for example, by a line of perforations. The upper half of the marker is printed in solid black to make a screen 14 thereof opaque to actinic rays, and the lower half is printed with a suitable legend 15 to indicate the information required to be filled in. Such information is illustratively indicated in script. Both the printed legend and the matter written in script are formed of an ink opaque to actinic rays, or the script portion may be written in pencil.

. fying screen 4 and the plate 5, and the label area being disposed between the lower intensi fying screen 11 and the plate 5. When the parts have been assembled in the relation shown in Figure l, the plate is ready for an exposure. When the exposure is made, the Roentgen rays pass readily through the aluminum plate 2. Any actinic rays which may be present are absorbedby the sheet 3. The Roentgen rays falling upon the fluorescent intensifying screen 4 produce actinic rays which have the characteristic of being much more effective upon the photographically active substance on the plate 5 than the unconverted Roentgen rays. The screen portion 14 of the marker 8 prevents the passage through to the plate of the actinic rays from the screen 4, permitting only the Roentgen rays to pass. The Roentgen rays pass through both folds of the marker to the lower fluorescent intensifying screen, and there result in the further production of actinic rays. The actinic rays thus produced, or a considerable proportion of them, pass back through the label and reach the plate in all areas thereof not in registration with the printed or written matter on the label. The printed and written areas of the label are again protected from the action of the actinic rays, and since the photographic plate lies directly in contact with the label, the marking on the label is caused to be clearly and distinctly shown on the plate when the plate is subsequently developed.

As has already been mentioned, the marker might be disposed in the opposite way from that described, with the label portion interposed be tween the photographic plate and the upper intensifying screen and with the screen portion interposed between the photographic plate and the lower intensifying screen. In this case the screen portion would act to prevent the reflection back of any actinic rays from the lower screen, and would thus prevent the marking from being rendered indistinct by reflected rays.

In Figure 7 disclosure is made of a modified means of practicing the invention, the arrangement in'this case consisting in the printing on one of the intensifying screens, say the screen 4, of an area 16 of solid black. This black area is designed to be used as a protective screen in lieu of the screen area of the marker'S. The printing may be applied to either one, but not to both, of the intensifying screens. In such case the label will always be placed between the photographic plate and the unprinted intensifying screen. I prefer, however, to follow the practice illustrated in Figures 1 to 6, inclusive, since the folded label may be conveniently and accurately placed with reference to the plate and constitutes a fool-proof means for assuring that the marker screen will be located at the opposite side of the plate from the label, and that it will be in exact registration with the label.

The markers may be of various colors and shades of colors according to the degree of transparency to actinic light which is desired, certain reds, yellow, and certain shades of green being useful in this connection.

The term completely opaque as used in the appended claims is not intended to refer to the degree of opaqueness of the shielding means but rather to the uniformity or solidity of the shielding in the marking area.

I have described what I believe to be the best embodiments of my invention. I do not wish, however, to be confined to the embodiments shown, but what I desire to cover by Letters Patent is set forth in the appended claims.

Iclaim:

1. The method of marking radiographs, which comprises interposing a photographic plate between a pair of fluorescent intesifying screens,

interposing between the plate and one of the intensifying screens, a screen completely opaque to actinic rays through the entire marking area, interposing symbols opaque to actinic rays between. the plate and the other intensifying screen within the marking area, and taking the exposure.

2. The method of marking radiographs, which comprises interposing a photographic plate between a pair of fluorescent intensifying screens,

shielding a marking area completely from actinic rays emanating from one of the intensifying screens, shielding symbol areas within the marking area fromactinic rays emanating from the other intensifying screen, and taking the exposure.

3. In combination, a photographic plate, fluorescent screens at opposite sides of the plate, and a sheet of material folded about a marginal portion of the plate, and having the folds there- 1 of interposed between the plate and the respective intensifying screens, one of said folds being completely opaque to actinic rays, and the other being generally transparent to actinic rays, but opaque to such rays in symbol areas.

4. A radiograph marker comprising a piece of sheet material having a longitudinally extending fold line provided substantially along the middle thereof, and having one of its folds completely opaque to actinic rays, and the other transparent to actinic rays except in selected areas.

5. A radiograph marker comprising a screen completely opaque to actinic rays, and a label ggenerally transparent to actinic rays, the screen and label being hingedly connected to'one another and adapted to be folded against opposite faces of a photographic plate.

6. A radiographic marker consisting of a sheet of material, one half of said marker being uniformly treated to prevent or minimize marking of a photographic plate from the side of the plate at which it lies, and the other half being generally transparent to actinic rays and adapted 7. A fluorescent screen for use in radiographing, said screen having a limited portion of the exit face thereof rendered uniformly opaque to actinic rays and adapted to overlie amarking area of the photographic plate.

8. A cassette for use in radiographing, including a pair of fluorescent screens adapted to have a photographic plate placed between them, one of said screens having an area of its surface that faces toward the plate rendered uniformly opaque to actinic rays.

9. The method of marking radiographs, which comprises marking symbols opaque to actinic rays upon-a label generally transparent to actinic rays, interposing the label between a photographic plate and a fluorescent screen at one side of the plate, completely shielding the marking area of the photographic plate against exposure to actinic rays from the side opposite that at which the label is placed, and taking the exposure.

HAROLD S. SAWFORD.

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