DE2800081A1 - METHOD AND DEVICE FOR CHECKING PHOTOGRAPHIC VARIABLES - Google Patents

Description

AGFA-GEVAERT AG

LEVERKUSEN 2 B O O O 8

- 3 CW 2001.9 PR / MR CAMERA-WERK MUNICH

PATENT DEPARTMENT

10-pa-yes

Method and apparatus for checking photographic variables

The invention relates to a method for checking photographic Variables, in particular for checking the quality of the layer support as well as those influencing the photographic recordings Factors.

In X-ray technology, it is common today to place a film next to the actual X-ray image at a suitable point Imprint identifying text containing a statement about the name of the patient, address, name of the treating doctor, and the date of admission etc. contains. Both this data imprinting and the x-ray fluoroscopy of the patient can go so far today can be controlled satisfactorily that over a long period of time and for a large number of exposures substantially the same light or X-ray intensities can be obtained. On the other hand, however, it is possible that different Can change characteristics or development variables. Likewise, the film quality and its Properties as well as other factors change. For example, the quality or brightness of an X-ray changes,

809838/0556

CW 2001.9 PR / MR - 4 -

which was created a few days earlier.

The object of the invention is therefore to create a method of the type mentioned at the outset in which, with simple means, undesired Changes can be recognized quickly so that appropriate countermeasures can be initiated.

This object is described in the characterizing part of claim 1 Invention solved.

With the invention it is achieved that when comparing the levels of blackening of different X-ray recordings, for example conclusions can be drawn about changes in the development process. If the development is insufficient, the corresponding density level appears one picture is lighter overall than the corresponding density level or scale of another picture. With excessive development on the other hand, the density level will appear a little darker. If there is a deviation of only one level, it can turn to another changed factor of the development process.

The object of the invention is also to create a simple device to carry out the procedure. Such a device is the subject of the characterizing part of claim 4.

From DT-PS 261508.2 a device for attaching identification marks to photographic film is known. With this device a prepared identification card is placed in an exposure device inserted and with the insertion of a

809838/0556

CW 2001.9 PR / MR - 5 -

Film cassette releases a flat luminous element that projects the data from the card onto the film. This imprinting of Data can be taken before or after the x-ray.

With the invention, this known exposure device is now developed in such a way that a density scale is also available at the same time as the imprinting of identifying data on the substrate can be applied. This is preferably done with the same light source that is used for the data imprinting will. Achromatic filter elements with different transparency are preferably used as the scale, which are shown in Areas or strips are arranged side by side.

The inventive use and configuration of the known Exposure device for the method according to the invention is also This is advantageous because the imprinting of the density scale can take place at the same time as the imprinting of the data, so no additional one Step is necessary. The expansion of this device is possible with little effort and at low cost.

Further details and advantages of the invention emerge from the subclaims in connection with the description of a Embodiment, which is explained in detail with reference to figures. Show it:

FIG. 1 is a perspective view of an exposure device;

809838 / 0BB6

FIG. 2 shows a partial cross-section 2-2 through the one shown in FIG Facility;

FIG. 3 is a plan view of an essential part of the device shown in FIG. 1; and

FIG. 4 shows a graphic representation of the results of a comparison of different X-ray recordings for Detection of undesired deviations between these recordings.

FIG. 1 shows an embodiment of an exposure device which is used for the purpose according to the invention can. The exposure device 10 for X-ray film has a flat support surface 11 on which an X-ray film cassette is placed can be. Furthermore, there is a guide flange 15 and a stop 16 provided for guiding or stopping a cassette. Furthermore, a luminescent element is in the exposure device 10 20 arranged of substantially rectangular shape, the light of sufficient intensity for the electrical excitation Emits exposure of an X-ray film in the cassette. As is clear from FIGS. 2 and 3, the luminescent element a protruding flap part 21 which is connected to a rear part 22 by means of a flap hinge 23.

Clamping plates 25 and 26 are fastened to a flange 28 of a fastening bracket 30 for holding the rear part 22. At the leading edge the bracket 30 has two upstanding eyelets 32 and 33

809838/0556

forms in which guide rods 35 and 36 are contained. Means an upper and a lower plate 42 and 43, respectively, form a carriage 40 which is movably supported by the guide rods 35 and 36 is, wherein the plates 42 and 43 are arranged at a distance from the opposing surfaces of the luminescent element 20 are. Two pivot pins 47 and 48 project outwardly at the rear corners of the carriage 40 and are carried in the sleeves 50 and 51 surrounding the guide rods 35 and 36. the Sleeves 50 and 51 are in a forward position by means of two helical springs 53 and 54, which enclose rods 35 and 36 biased.

With this arrangement, the carriage 40 can from its front, in the position shown in Figures 2 and 3 in a rearward position (not shown) against the force of the springs 53 and to be brought. In the forward position, the carriage shields the luminescent element 20 sufficiently so that all of it Element outgoing light is captured. When the carriage 40 is moved into its rearward position, however, this is brought out of its shielding position with respect to the luminescent element, so that the light emitted by this element 20 to Exposure of a film in an inserted cassette can be used.

The slide 40 can also, together with the tab part 21 of the luminescent element 20, about the axes of the pins 47 and 48 be swiveled upwards. This pivoting movement takes place

809838/0556

against the bias of two springs 55 and 56, which the carriage 40 with the tab part 21 normally in one plane hold with the rear part 22 of the plate. This rear part of the plate is provided with electrically conductive strips 57 and 58 Provide excitation of the plate.

As can be seen from Figure 2, _f is facilitated by the upward pivoting of the carriage 40, the insertion of a folded data card 59th This data card can, for example, carry information such as name, address, treating doctor, identification number and the like. This map can be created on any suitable printer or copier, such as a typewriter.

In operation, the card 59 is placed over the protruding tab portion 51 and an X-ray film cassette in which there is an X-ray film is placed on the device shown. The cassette is guided in the direction of the luminescent element 20, whereby the leading edge of the cassette hits the carriage 40, which is thereby pushed or forced into its rearward position will. The slide 40 is thus brought out of its shielding position with respect to the tab part 21 and the luminescent element 20. With the further movement of the cassette, the card 59 and the luminescent element 20 move into an opening (not shown) inserted in the cassette. If the cassette is then correctly positioned, a corresponding electrical excitation is generated Circuit a switch is closed, whereby the luminescent element 20 via the conductor strips 57 and 58 is excited.

809838 / θΒΒβ

Accordingly, a predetermined amount of light for a also a predetermined period of time from the luminescent element, so that the X-ray film in the cassette with the data is exposed on the card 59.

After this exposure, the patient is X-rayed. Of course, the X-ray can also be done before after imprinting the data. As is also described in DT-PS 2615082, is located in the X-ray film cassette a suitable lead plate to prevent x-rays from entering the marking area on the film within the Cassette reached.

FIG. 3 also shows a density scale 70, which is preferably located on the edge of the luminescent element 20. In another embodiment of the invention, this density scale can be formed on the data card 59 or integrally therewith be. This density scale consists of a large number of areas of different density, for example areas or Strips 70 A, 70 B, 70 C and 70 D. The different densities of these areas lead to different light emissions Intensity which is transmitted from the luminescent element 20 to the X-ray film in the cassette. For example, the Stripes 70 A have the lowest density, i.e. H. be the strip through which the greatest intensity of light is transmitted. The remaining Strips 70 B, 70 C and 70 D gradually have an ever greater density, so that an ever lower light intensity

809838/0556

is transmitted. The stripe 70 D is therefore the darkest stripe.

As long as the carriage 40 is in its shielding position, the density scale 70 is also covered. However, as soon as an X-ray film cassette has been inserted and the carriage in its rear Position is brought, the light coming from the excited luminescent element 20 also penetrates through the strips 70 A to 70 D, so that the film in the cassette is exposed to the light density scale. This means that the X-ray film is made at the same time as the data card 59 and the density scale 70 exposed. This means that the latent images on the film have light intensities which the lightest stripe 70 A, the two-lightest stripe 70 B, the second darkest stripe 70 C and the darkest stripe 70 D correspond.

When the X-ray and the imprinting of the data and density scale have taken place, the film is developed in the conventional manner. This creates a visible image on the film consisting of data, the corresponding strips 70 A to 70 D different Densities and the patient's x-ray. Each stripe image on the X-ray film can be measured by suitable density measuring devices be measured, which provides information about the relative brightness of each strip and, accordingly, information about the relative brightness of the X-ray image can be achieved. As a density measuring device, for example, a simple Densitometers are used.

809838/0556

The measurement results delivered by such a densitometer reflect the different light intensities which are transmitted the corresponding stripes in the density scale 70 have been transferred. Each exposure becomes essentially the same Amount of light transmitted through the corresponding strips for the same period of time. If all variables in the recording and developing process remain constant from day to day, it can therefore be assumed that the density measurement results of the corresponding strips of one developed X-ray film will remain essentially the same until the next. This means that the measured transparency of for example, the reproduced strip image 70 A is the same for all developed X-ray images. In the same way would have to also, the transparency measurements for the other strips will be essentially the same for all developed x-ray films. If also the exposure device and the variables can be largely controlled, it has often been found that over a period of time Changes in the development process of the X-ray film, the quality of the film, etc. can occur. If noticeable Deviations in the measured brightness or transparency of the respective stripe images are found, is therefore the Probability is close that a factor in the development process or another characteristic has changed.

To show the way in which the measurement results of the reproduced Density scale can be used to determine noticeable discrepancies between developed X-ray images

809838 / 05S6

reference is made to the graphic representation in FIG. The density values supplied by the densitometer are plotted on the ordinate, while the dates on which the X-rays were taken and developed are entered on the abscissa. If a large number of X-ray exposures are taken daily, only one exposure or a small number of exposures is needed to be measured per day. The measured values A, B, C and D correspond the respective densities of the reproduced stripe images 70 A, 70 B, 70 C and 70 D. If all factors or variables For example, if they remain constant during development, it is to be expected that the measurement results A to D will also essentially apply to all of the tested X-rays remain the same. Assuming that such variables change within specified tolerances is acceptable, the corresponding curves for measurements A through D may generally fluctuate around an average level measured. Any deviation from a given density measurement can thus easily be determined whereupon the appropriate steps to correct the development process or to compensate other factors can be taken accordingly.

As can be seen from FIG. 4, the measurement results A to D from day 2 are essentially the same as those from day 1. On day 3 however, it can be seen that the density values deviate from the measured average value. Depending on whether these deviations are acceptable are or not, appropriate corrections can be made in the development or for other characteristics. Assuming that such corrections have been made, it is certain

809838/0556

CW 2001.9 PR / MR - 13 -

ensure that the measurement results on day 4 are again almost the average measurement value. On day 5, however, it gives way Density of the strip 70 C from the average value by an unacceptable degree. In this case, appropriate precautions must be taken that the quality of the following X-ray images is acceptable again. The further course of the curve in Figure 4 shows how other x-rays can be checked and measured to determine whether the quality of these images is satisfactory is.

The invention provides quality control for x-ray recordings or in the process of developing X-ray films in a simple manner. By exposing an X-ray film in a cassette with a density scale and then by measuring the densities of the reproduced scale, undesired changes in the recognized recordings quickly. Appropriate steps can then be taken to ensure that later Recordings can be properly handled so that accurate x-rays can be made.

809838/0556

Claims (7)

AGFA-GEVAERT AG CW 2001. 9 PR / MR CAMERA-WERK MUNICH PATENT DEPARTMENT 10-pa-yes Jan. 2, 1978 Claims 1. A method for checking photographic variables, in particular for checking the quality of the substrate and the factors influencing the photographic recordings, characterized in that a plurality of substrates is exposed in the same way at a free point with differently graduated light intensities on the substrates After development, different blackening areas reproduced are measured for their transparency, the blackening values of the same light intensities are compared and an average value is formed and a corresponding process correction is made when a blackening value deviating from this average value is recognized. 2. The method according to claim 1, characterized in that for exposure of the layer support a density scale with different Permeability areas brought into close proximity to the substrate and from a uniform Light source, preferably a large-area luminescent element, is irradiated. 809838/0556 ORiGiNAL INSPECTED CW 2001.9 PR / MR - 2 - Ü800081 3. The method according to claim 1 or 2, characterized in that the different blackening areas of the developed Layer substrate can be measured in a densitometer and compared graphically with one another. 4. Device for performing the method according to claim 1, characterized by an exposure device (10) known per se for exposing identifying data on a layer support located in a cassette an image-free area, with a luminous element (20) which can be pushed into the cassette opening and onto which a data card (59) can be applied, and is formed by a plurality of areas (70 A to 70 D) of different densities Scale (70) which, when the cassette is inserted, lies between the layer support and the luminous element (20). 5. Apparatus according to claim 4, characterized in that the scale (70) on the luminous element, for example one Luminescent element (20) is applied. 6. Apparatus according to claim 4, characterized in that the scale (70) is attached to the data card (59). 7. Device according to one of claims 4 to 6, characterized in that that the scale (70) is formed by achromatic filter elements of different densities (70 A to 70 D). For this purpose 2 sheets of drawings 809838 / 05R6