Dental X-ray diagnostic installation
FIELD OF THE INVENTION 
     The present invention relates to a dental X-ray diagnostic installation. 
     DISCUSSION OF THE PRIOR ART 
     A dental X-ray diagnostic apparatus is presently known possessing an X-ray tube arranged within a housing, and which includes a hollow anode introducible into the mouth of a patient. The hollow anode is encompassed by a cylinder-shaped applicator which is provided with a radiation outlet window from which there exits the X-radiation. Through the known X-ray diagnostic apparatus it is possible to undertake photographic surveys or charts of the upper jaw, the lower jaw, the jaw joints and the adjacent cavities. The preparation of an exposure is carried out in a manner in that the applicator, the latter of which is rotatable on the hollow anode, is brought into that position in which the X-radiation passes through the area of the patient which is to be photographed or X-rayed, the hollow anode together with the applicator being then inserted into the mouth, and that the patient applies the X-ray film to his face in the region which is to be X-rayed. The known X-ray diagnostic apparatus is thus only suited for the preparation of X-ray exposures and not for X-ray radioscopies in the jaw region. 
     SUMMARY OF THE INVENTION 
     Accordingly, it is an object of the present invention to so further equip and improve an apparatus of the above-mentioned type whereby, in addition to being suited for the preparation of X-ray exposures, it is also suited for effectuating X-ray radioscopies of the jaw region. 
     The foregoing object is inventively achieved in that the X-ray tube has an X-ray image intensifier associated therewith, and that means are provided which permit an alignment of its inlet screen with the focus of the X-ray tube. The X-ray image intensifier, during the carrying out of radioscopies, receives the X-radiation emanating from the patient and amplifies the radiation. Accordingly, it thereby permits the observation of the presently produced X-ray image either directly through an optical device associated with its outlet screen, or indirectly through the intermediary of a video system connected to the output thereof. 
     A suitable further construction of the invention consists of in that the image intensifier is fastened to a support which is rotatable about the axis of the X-ray tube. This support allows the X-ray image intensifier to be set to the region of the patient which is to be currently examined. It is particularly suitable that a protective cap, which is seated on the anode and rotatable with respect thereto about the longitudinal axis of the anode for radiation focusing (applicator), be so connected with the support so as to be taken along therewith during rotation of the support. During the adjustment of the X-ray image intensifier there is thus effected an automatic adjustment of the protective cap. A coordination with the current patient is possible when the image intensifier is connected with its support so as to be displaceable along the direction of the central beam of the X-radiation. Within the scope of the invention, the X-ray tube and the image intensifier may also be constructed as a unit which is freely held by the physician or dentist on a handgrip. Furthermore, it is possible that the X-ray image intensifier be constructed as a unit which is separate from the X-ray tube, which is manipulated by the physician separately from the X-ray tube, for example, held in the hand. Hereby, in order to render possible the satisfactory alignment of the X-ray image itensifier with the focus of the X-ray tube, it is thereby recommended that the X-ray tube housing be provided with orienting means for the aligning of the X-ray image intensifier. For instance, these orienting means may be a stop or a guide sleeve. Furthermore, for the case in which the X-ray tube housing is mechanically connected with the image intensifier, it is possible that for the adjustment of the X-ray tube together with its housing about the longitudinal axis of the image intensifier, it be pivotably connected with the image intensifier. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Reference may now be had to the following detailed description of exemplary embodiments of the invention, taken in conjunction with the accompanying drawings; in which: 
     FIG. 1 schematically illustrates a dental X-ray diagnostic installation constructed pursuant to the present invention; 
     FIG. 2 illustrates the installation, drawn on a reduced scale, suspended from a ceiling support; 
     FIG. 3 illustrates a modified embodiment of the installation; 
     FIG. 4 illustrates an enlarged view of the inventive installation in which the X-ray image intensifier is constructed as a unit separate from the X-ray tube housing; 
     FIG. 5 illustrates a modified embodiment of the installation of FIG. 4; and 
     FIG. 6 illustrates a further embodiment of the inventive installation. 
    
    
     DETAILED DESCRIPTION 
     Referring now in detail to the drawings, in FIG. 1 there is shown an X-ray tube for dental X-ray radioscopies and exposures and the associated high-voltage transformer arranged within a housing 1. The X-ray tube possesses a hollow anode 2 which is able to be inserted into the mouth of the patient, and which is encompassed by a cylinder-shaped protective cap 3 serving for radiation focusing. The protective cap 3 possesses an aperture 4 through which there can egress the X-radiation, and is rotatable on the hollow anode 2 about the longitudinal axis of the latter. In the exemplary embodiment according to FIG. 1, the hollow anode 2 is inserted into the mouth of a patient 5. X-ray exposures can be prepared when a phantom-drawn X-ray film 6 is applied to the exterior of the face of the patient in the region which is to be X-rayed. 
     In order to undertake X-ray radioscopies there is provided an X-ray image intensifier 7 which has a television camera 8 connected to the output thereof. The X-ray intensifier 7 has its input screen aligned with the focus 21 of the X-ray tube. The unit 7, 8 is fastened to a support 9, the latter of which possesses a plate 10 which is rigidly interconnected with a ring 11. The unit 7, 8 is located on the plate 10 so as to be adjustable in the direction of the double-headed arrow 12, meaning in the direction of the central beam of the X-radiation, and thus can be set on the patient. The adjustment of the unit 7, 8 on the region of the patient 5 which is to be X-rayed is carried out through rotation of the ring 11 on the housing 1 about the axis 11a of the latter, and which also forms the axis of the X-ray tube and the anode 2. The ring 11 is connected with the protector cap 3 through intermediary of a coupling element 13 so that, upon rotation of the ring 11, the protector cap 3 is taken along and the window 4 similarly is automatically brought into the correct position. The ring 11 is lockable in position with respect to the housing 1. Furthermore, the unit 7, 8 is also lockable in position with respect to the plate 10. 
     The illustrated X-ray diagnostic apparatus allows the carrying out of dental X-ray radioscopic exposures. The X-ray image is hereby reproduced on a video viewing apparatus (not shown) which is controlled by the television camera 8. In lieu of the television camera 8 there may also be arranged a photographic film camera for the preparation of X-ray film pictures. 
     The housing 1 is mounted on a support column 14, the latter of which is supported on the floor in a manner not illustrated herein. 
     According to FIG. 2, the X-ray tube housing 1 which carries the image intensifier 7 and the television camera 8 through intermediary of the support 9, can also be suspended from a ceiling support 15. 
     FIG. 3 illustrates an embodiment of the invention in which there is located in one housing 16 merely the hollow anode X-ray tube. The high-voltage transformer is arranged on the wall or on the floor externally of this housing, and a high-voltage conduit 17 leads from therethrough a hollow handgrip 18 to the X-ray tube in the housing 16. Connected with the housing 16, in accordance with the embodiment pursuant to FIG. 3, is the X-ray image intensifier 7, whose picture may be observed on the outlet or target screen through an optic device 19. The dentist can thereby hold the unit 7, 16 in his hand by means of handgrip 18 and insert the hollow anode into the mouth of the patient. On the handgrip 18 he can also bring the unit 7, 16 into the presently desired position, and observe the X-ray image through the optic device 19. In the examples according to FIGS. 2 and 3, the patient lies in a dental chair 20. 
     FIG. 4 illustrates an exemplary embodiment of the invention in which the X-ray image intensifier is constructed as a unit separate from the X-ray tube housing, in effect, can be manipulated by the physician independently of the X-ray tube in the housing 1. Mounted on the housing 1 by means of two screws 22 is an extension arm 23 which is provided with a recess 24 into which fits the image intensifier 7 with one end thereof. The recess 24 is clearly visible in the front view represented by FIG. 4. In this front view, the image intensifier has been omitted for purposes of clarity. 
     In order to undertake a radioscopy the physician guides the anode of the X-ray tube into the mouth of a patient, after he had slid on the protective cap 3 which possesses a radiation outlet aperture which is smaller than that of a protective cap which serves for the taking of X-ray exposures. Thereafter he positions the image intensifier 7 on the extension arm 23 and pivots it by hand in the desired direction. 
     The exemplary embodiment pursuant to FIG. 5 distinguishes from the exemplary embodiment shown in FIG. 3 in that an extension arm 25 is resiliently attached onto a projection 26 on the X-ray tube housing 1. For this purpose the projection 26 possesses suitable grooves. 
     The projection 25 is constructed as a portion of a cylindrical sleeve at its angled end 25a so as to thereby readily guide the image intensifier 7. 
     In the exemplary embodiment according to FIG. 6, an extension arm 27 is connected with the X-ray tube housing 1 by means of a bayonet lock 28, at whose end there is arranged a sleeve 29 in which there fits the image intensifier 7 with a close contact. This exemplary embodiment permits a particularly simple alignment of the image intensifier 7 with the focus of the X-ray tube. In the exemplary embodiment according to FIG. 6, the radiation protective cap 3 is fixedly connected with the extension arm 27. This radiation support cap, as described, possesses a small radiation outlet window 30 which is arranged for examination with an X-ray image intensifier. It is slid onto a radiation protective cap 31 which serves for the preparation of X-ray exposures, and which possesses a larger radiation outlet window 32. In order to undertake a dental X-ray radisocopy, in accordance with the exemplary embodiment of FIG. 6, the radiation protective cap 3 with the extension arm 27 is thus slid onto the radiation protective cap 31, and the bayonet lock 28 is secured. Thereafter, the image intensifier 7 can be slid into the guide sleeve 29. 
     The exemplary embodiments according to FIGS. 4 through 6 presently illustrate the side of the X-ray tube housing with the X-ray protective cap associated with the X-ray tube anode, and with the X-ray protective cap in, respectively, a partly sectioned side view and in a front view. In the exemplary embodiment according to FIG. 6, through the attachment of the components 3 and 27 it is possible to automatically actuate a switch which switches over at least one operative value for the X-ray tube, particularly the X-ray tube current, to the magnitude which is required for an image intensifier radioscopy. 
     While there has been shown what is considered to be the preferred embodiment of the invention, it will be obvious that modifications may be made which come within the scope of the disclosure of the specification.