US 3846634 A
An imprinter for printing an identifying legend on dental X-ray film of the type having an unexposed area in the center of the film. The film is exposed during an X-ray scan of the patient's dental structures producing a single film showing all the dental structures of the patient. The identifying legend is then immediately imprinted in the center of the film and the remaining unexposed center area is blacked out thus facilitating the reading of the film after it has been developed.
Description (OCR text may contain errors)
United States Patent [191 Fleming METHOD FOR PRINTING AN IDENTIFYING LEGEND ON A PANORAMIC DENTAL X-RAY FILM Robert D. Fleming, 675 Pelzer Dr., Iowa City, Iowa 29464 Filed: Mar. 14, 1973 Appl. No.: 341,096
US. Cl 250/476, 250/323, 250/490 Int. Cl. G03b 41/16 Field of Search 250/312, 320, 322, 323,
References Cited UNITED STATES PATENTS 9/ l 931 Reedy 4/1936 Cantor.. ll/l940 Evans Nov. 5, 1974 2,630,534 3/l953 Heinecke 250/67 3,045,118 7/1962 l'lollman et al. 3,296,437 1/1967 Meschan 250/476 Primary Examiner-William F. Lindquist Attorney, Agent, or Firm-James C. Nemmers; Haven E. Simmons 2 Claims, 3 Drawing Figures CASE NO.
DENTAL RADIOLOGY DATE 93L) ne a no V v k PATENTEUHUY 5 m4 FIG 3 METHOD FOR PRINTING AN IDENTIFYING LEGEND ON A PANORAMIC DENTAL X-RAY FILM BACKGROUND OF THE INVENTION For many years the X-ray has been used as an extremely valuable aid in medical and dental diagnoses. Improvements in X-ray techniques and films have resulted in the development of apparatus that will rapidly scan the entire mouth and produce a single film showing the entire dental structures of the patient. One such apparatus, the Panorex panoramic X-ray machine marketed by Pennwalt Corporation, is designed so that it will scan over one-half of the dental structures starting at the side and terminating just beyond center in the front. Exposure to the X-ray is then temporarily interrupted while the patient is moved to the side before the second half of the scan, during which more than onehalf of the dental structures on the other side of the mouth is scanned starting at the front just beyond center and continuing to the side opposite that where the first half scan began. This produces a film which shows the front portion of the dental structures from 'two different angles enabling the dentist to view this portion of the mouth in a way that may reveal conditions that would not otherwise be revealed. However, because the exposure was momentarily stopped while the patient is turned, the film produced contains an unexposed center portion, and when the film is developed this portion appears as a clear vertical band on the rectangular film. When the film is placed in a lighted viewer to enable the dentist to study the film, this middle band allows the transmission of considerable light and at times can interfere with the reading of the film, particularly in those portions adjoining the unexposed band. To avoid this problem, some practitioners cut and splice the film to eliminate the unexposed band. This practice is not recommended because such a film is inadmissible evidence in court in the event of any lawsuit. Also, with the film used in this type of a panoramic apparatus, proper identification is usually made after the film is exposed by placing a piece of tape or other material in the unexposed center band. This is not entirely satisfactory because it can lead to improper identification and mix-up between the time the film is taken and the time the identifying legend is marked on the film subsequent to development and drying of the film. Although there are known and used film imprinters which allow the imprinting of an identifying legend on X-ray film or other photographic material prior to development of the film, none of those known can be used for film of the type described in which the center portion is unexposed without covering up some of the radiographic anatomy. In a large general hospital or clinic where thousands of such films are processed each year, known methods of placing an identifying legend on the film have not worked satisfactorily and present known printers cannot be used with any degree of efficiency. There is, therefore, a need for a low cost imprinter and a method by which films of the type described herein can be quickly, efficiently and accurately imprinted with an identifying legend. It is the object of this invention to provide such an apparatus and method.
I SUMMARY OF THE INVENTION The invention provides a method and apparatus for rapidly imprinting the unexposed center portion of a dental X-ray film of the type described herein. After the film is exposed in the X-ray apparatus, it is removed from the apparatus and taken to a darkroom. The imprinter has a flat upper surface containing a recessed area with a translucent material covering the recess. The recess is sized to receive a standard card containing the identification information imprinted thereon. The undeveloped film is then placed on top of the im printer over the card so that the unexposed middle area is directly over the card. Beneath the translucent material is a light source that is actuated when a hinged lid on the imprinter is lowered, thus exposing only the unexposed central portion of the film and imprinting thereon the information contained on the card. The imprinter contains an adjustable stop to assure proper registration of the unexposed portion of the film over the light source. The imprinter also contains a method of varying the intensity of the light while maintaining the time of exposure constant so that the proper exposure time can be regulated. The imprinter is battery operated and thus portable and inexpensive, and it is also safe for use in a darkroom containing tanks of developing liquids which may produce wet conditions that cause an electrical hazard where higher voltage equipment is used.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view of an X-ray film of the type to which the invention applies and showing the legend imprinted thereon;
FIG. 2 is a perspective view of an apparatus for imprinting the legend on the film of FIG. 1; and
FIG. 3 is an end view of the imprinter, partly in section, to show the light actuating mechanism.
DESCRIPTION OF THE PREFERRED EMBODIMENT OF THE INVENTION Referring to FIG. 1, there is illustrated a film 10 which shows the entire dental structures of a patient produced on a single film by panoramic X-ray apparatus of a type well-known to those skilled in the art. The film thus produced shows the left side of the patients mouth on the right side 12 of the film l0, and the right side of the patients mouth on the left side I4 of the film. The center portion 16 of the film l0 commonly is unexposed and thus completely transparent. This transparent band 16 is produced when the X-ray apparatus scans first the left side of the mouth and stops while the patient and chair move to the side. The radiation is again started and the machine scans the other half of the patients dental structures. During the time that the apparatus is changing its axis of rotation, the radiation is stopped to avoid unnecessary exposure of the patient to the X-rays. This produces a film with a transparent band 16 in its center on each side of which there is shown a portion of the patients mouth from two different angles. This type of film is very beneficial to the dentist and aids in diagnosing conditions which might otherwise not be readily apparent. However, the transparent band 16 has the disadvantage in that when the film 10 is placed on a light viewer containing a high intensity light so that the film 10 can be studied, the light 3 will shine through the transparent band 16 and interfere with viewing of the film, particularly thoseportions of the anatomy near the band 16 which have been viewed from two different angles. Note, however, that the transparent band 16 does provide a place upon which an identifying legend can be placed so that the film can be identified with the correct patient. FIG. 1 shows an identifying legend 18 imprinted thereon using the method and apparatus of the invention. Also, in FIG. 1 the identifying legend 18 is not shown in black, but it should be understood that on a regular X-ray film that the portion between the two lines 19 would be fully exposed except for the imprinted identification which'would be of course transparent. In other words, the band 18 shown in FIG. I is the reverse of what would be shown on an X-ray film negative 10.
In FIG. 2 there is shown an apparatus for imprinting the identifying legend 18, which apparatus has been constructed according to the principles of the invention. The apparatus is preferably box-shaped having side walls 20 joined by end walls 22, a bottom wall 24, and a top surface indicated generally by the reference numeral 26. The top surface 26 contains a rectangular shaped recess 28 which is preferably of a length and width to accommodate a standard size card, such as a 3 inch by 5 inch card. Extending the entire length along the center of the recess 28 is a band of translucent material 30 that will diffuse the light from a light source such as bulb 32. Preferably, there are provided two such bulbs 32, one at each end of the translucent band 30. The bulbs 32 are connected in a circuit with a switch 34, a potentiometer 36, and a source of power such as a battery (not shown). The components in the circuit are connected in series so that upon closing of the switch 34 the circuit will be complete and power supplied to the bulbs 32 to produce light through the translucent band 30. If desired, a small indicator lens 38 can be provided in end wall 22 so that the operator will know that the bulbs 32 have been lighted.
Hinged at the juncture of the top surface 26 and end wall 22 is a lid 40 containing a piece of soft, compressible material 42 that is approximately the size of the recess 28. Removably mounted on one side wall 20 is a tray 44 containing an adjustable stop 46 and an edge guide 48. If desired, a supporting member (not shown) can be provided beneath the tray 44 to provide additional support for the tray at its outer end.
Referring now to FIG. 3, there is shown a mechanical mechanism for operating the switch 34 and holding it closed a predetermined time. An actuating rod 50 extends vertically through the top surface 26 at the end of the apparatus near the end wall 22 opposite to the end where the lid is hinged. Rod 50 is vertically movable in an opening 52 in the upper surface 26 and in a hollow guide member 54 mounted on the bottom wall 24 inside the apparatus. Guide member 54 preferably contains a resilient member such as spring 56 that will return the operating rod to its initial position after it has been depressed and the force removed. Operating rod 50 contains a cam member 58 engageable with a follower 60 that is mounted on one leg 62 of a U- shaped spring 64. The other leg 66 is secured to the inside of side wall 20. A pair of contact members 68 are mounted on the legs 62 and 66 of spring 64 to form the switch 34. In other words, when the contacts 68 are touching, the circuit connecting the bulbs 32 to the power source to the potentiometer 36 will be completed. Obviously, when the mechanism is in the position shown in FIG. 3, the circuit is not completed and the operating rod 50 extends above the top surface 28 of the apparatus. However, when the rod 50 is depressed, the cam 58 will engage follower and close the switch 34 by engaging contacts 68 which will remain engaged for the period of time that the rod 50 is depressed and released. If the rod 50 is depressed until the top of it is flush with the surface 28 and then is immediately released, the switch 34 will remain closed a predetermined amount of time, which time is determined by the design of the cam 58 and the distance the rod 50 extends above the surface 28. In this manner, the time that the light bulbs 32 are lighted will remain fairly constant thus giving a reasonably accurate time of exposure for a film placed in the apparatus. The light intensity can be varied by means of the potentiometer 36.
In use, the removable tray 44 is mounted on the side wall 20 of the apparatus and the stop 46 adjusted so that the unexposed band 16 of a film 10 will be directly over the translucent band 30. Once the stop 46 has been set for a particular size and type of film, it need not be subsequently adjusted. A card containing the desired identification data printed thereon is placed in the recess 28. The film 10, which is at this point not developed buthas been exposed in the X-ray apparatus, is placed in the apparatus in a position shown by the dotted line in FIG. 2. In this position, one edge of the film abuts stop 46 and one side edge lies along the edge guide 48. In this position, the unexposed band 68 of the film will be properly positioned over the translucent band 30. The operator then lowers the hinged lid 40, the outer end of which will engage the top of the operating rod 50 and depress it. If the operator lowers the lid until it can be lowered no further and immediately raises it at a normal speed, the exposure time of the film will be determined by the cam 58. Thus, the exposure time will remain constant for all of the films and the intensity varied by use of the potentiometer 36. The soft material 42 mounted on the under surface of lid 40 will assure that the film 10 is pressed tightly against the card when the lid is lowered. The soft material 42 also prevents damage to the film. When thus exposed in the apparatus of the invention, the otherwise transparent band 16 in the center of film 10 will be imprinted with the identifying legend 18, and the transparent band 16 will be substantially blacked out so as not to interfere with the reading of the film. After exposure in the apparatus of the invention, the film 10 is then developed and ready for reading.
The preferred embodiment of the apparatus of the invention that has been described herein, is obviously a very simple and inexpensive apparatus. It is portable, and since it uses low voltage batteries as a source of power, it can be used with safety in any darkroom. The apparatus and method of the invention provides a very fast, efficient way of positively imprinting identifying material on each film and practically eliminates errors of misidentification. The apparatus is so designed and the method conducted so that there is no possibility of damaging the unexposed film or exposed portions of the radiographic anatomy and thus rendering the film useless. Although I have described my invention only in connection with a preferred embodiment thereof, it will be obviousto those skilled in the art that various revisions and modifications can be made to the pre- 1 ferred embodiment without departing from the spirit and scope of the invention. It is my intention, however,
, that all such revisions and modifications as are obvious to those skilled in the art will be included within the scope of the following claims.
1 claim 1. A method for printing an identifying legend on dental X-ray film of the type having an unexposed area in the center of the film, comprising the steps of: exposing a portion of the film to X-rays during a scan of one side of a patients dental structures; stopping the exposure to X-rays for a brief time to allow repositioning of the patient relative to the source of X-rays; exposing another portion of the film to X-rays during a scan of the other side of the patients dental structures thereby producing a single film showing both the right and left sides of the patients dental structures, but with an unexposed area on the film between said sides; providing in a darkroom a light source whose path is confined to an area no greater than said unexposed area of said film; positioning in the path of said light source a translucent material containing the desired identifying information printed thereon; positioning said film with the unexposed areatherof in the path of said light source and with said material between the film and light source; exposing the said unexposed area of said film by activating said light source; and processing the undeveloped film to producea film showing the radiographic anatomy-of the patient in a single film with a darkened central portion there between containing the identifying information permanently imprinted thereon.
2. The method of claim 1 in which said light source is activated for a predetermined constant time, the intensity of said light source being selectively variable by the operator.