US4783793A
Expired / Lapsed
US
⏱️ 0.0 years remaining
X-ray apparatus for panoramic tomography including control system
Assignee: Planmeca Oy
•
Filing: 1986-09-09
•
Granted: 1988-11-08
•
Expires: 2006-09-09
Abstract
Abstract Panoramic tomography X-ray apparatus such as for obtaining images of dental systems, comprises a rotatably mounted arm to which the X-ray tube of an X-ray generator and an X-ray film cartridge, along with film transport equipment, are mounted, and a control system for controlling the functioning of the equipment of the apparatus on the basis of control data and a program pre-stored therein. A control system controls the speed of a rotary motion motor that rotates the arm, the speed of the film transport motor and the distribution of those speeds, independently of each other. In this manner, it is possible to photograph dental systems of varying sizes and shapes both sharply and with suitable exposure time. In addition to controlling the speeds of the rotary motion and film transport motors, the control system may also control the anode current and/or the anode voltage of the X-ray generator during the exposure sequence.
Inventors
- 👤 Arto Virta
- 👤 Pekka Strommer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 18:08
CPC Classifications
A; A61; A61B; A61B6/00; A61B6/50; A61B6/51
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
207 words
Panoramic tomography X-ray apparatus, such as for obtaining images of a dental system, comprising: an arm mounted for rotation; means for rotating said arm including a rotary motion motor; an X-ray generator having an X-ray tube with a tube head, said tube head being mounted on said arm for rotation therewith; a cartridge containing X-ray film mounted on said arm for rotation therewith; means for transporting said X-ray film including a film transport motor, said film transport means being mounted on said arm for rotation therewith; control system means for controlling the speed of said rotary motion motor of said arm, the speed of said film transport motor and the distribution of said speeds during an exposure sequence independently of each other as a function of control data and a working program in said control system means, so that dental systems of varying sizes and shapes can be photographed by said panoramic tomography X-ray apparatus both sharply and within a suitable exposure time; and said control system means adjusting the speed of said rotary motion motor and maintaining the speed of said film transport motor substantially constant, so that location of a layer being photographed is changed relative to the speed variations of the rotary motion motor.
Claim 2
Dependent Claim
207 words
Panoramic tomography X-ray apparatus, such as for obtaining images of a dental system, comprising: an arm mounted for rotation; means for rotating said arm including a rotary motion motor; an X-ray generator having an X-ray tube with a tube head, said tube head being mounted on said arm for rotation therewith; a cartridge containing X-ray film mounted on said arm for rotation therewith; means for transporting said X-ray film including a film transport motor, said film transport means being mounted on said arm for rotation therewith; control system means for controlling the speed of said rotary motion motor of said arm, the speed of said film transport motor and the distribution of said speeds during an exposure sequence independently of each other as a function of control data and a working program in said control system means, so that dental systems of varying sizes and shapes can be photographed by said panoramic tomography X-ray apparatus both sharply and within a suitable exposure time; and said control system means adjusting the speed of said rotary motion motor and maintaining the speed of said film transport motor substantially constant, so that location of a layer being photographed is changed relative to the speed variations of the rotary motion motor.
Claim 3
Dependent Claim
58 words
The combination of claim 1 wherein said X-ray tube operates with an anode current and an anode voltage, and wherein in addition to comprising means for controlling the speeds of said rotary motion and film transport motors, said control system means also comprise means for controlling one of said anode current and anode voltage of said X-ray tube.
Claim 4
Dependent Claim
32 words
The combination of claim 1 further including primary blind means associated with said tube head of said X-ray generator for adjusting the shape of a radiation beam generated by said tube head.
Claim 5
Dependent Claim
82 words
The combination of claim 3 wherein said primary blind means include means for defining an aperture situated in a path of said radiation beam and means for adjusting the size and shape of said aperture, and wherein in addition to comprising means for controlling the speeds of said rotary motion and film transport motors, said control system means also comprises means for controlling said aperture adjusting means of said primary blind means to control the size and shape of said aperture thereof.
Claim 6
Dependent Claim
92 words
The combination of claim 3 wherein said primary blind means include means for defining a plurality of apertures having differing sizes and shapes and means for positioning a selected one of said apertures in a path of said radiation beam, and wherein in addition to comprising means for controlling the speeds of said rotary motion and film transport motors, said control system means also comprises means for controlling said aperture positioning means of said primary blind means to control the selection of the aperture situated in the path of said radiation beam.
Claim 7
Dependent Claim
94 words
The combination of claim 1 wherein said control system means comprise: a microprocessor including a program memory in which said program is pre-stored and a working memory in which said control data is stored; a bus coupled to said microprocessor; input means coupled to said bus for controlling said system; output means coupled to said bus and rotary and film transport motors for inter-coupling said rotary motion and film transport motors and said microprocessor so that the direction of rotation of said motors and speed distribution of said motors are controlled by said microprocessor.
Claim 8
Dependent Claim
91 words
The combination of claim 6 further including primary blind means associated with said tube head of said X-ray generator for adjusting the shape of a radiation beam generated by said tube head, said primary blind means including primary blind motor means for operating said primary blind means, and wherein said output means of said control system means are coupled to said primary blind motor means for inter-coupling said primary blind motor means and said microprocessor so that the adjustment of the shape of said radiation beam is controlled by said microprocessor.
Claim 9
Dependent Claim
38 words
The combination of claim 6 wherein said output means of said control system means are coupled to said X-ray generator for inter-coupling said X-ray generator and said microprocessor so that the X-ray generator is controlled by said microprocessor.
Claim 10
Dependent Claim
33 words
The combination of claim 8 wherein said control system means further include means coupling said tube head of said X-ray generator and microprocessor for carrying status information from tube head to said microprocessor.
Claim 11
Dependent Claim
61 words
The combination of claim 1 wherein said control system means are programmed to control both the speed distribution of said rotary motion motor of said arm and the speed distribution of said film transport motor independently of each other so that chin profiles of substantially any shape or size can be photographed with a constant exposure under the control system means.
Claim 12
Dependent Claim
51 words
The combination of claim 1 wherein said X-ray tube of said X-ray generator operates with an anode current and an anode voltage, and wherein means are provided for carrying out said photography of a dental system with both a constant anode current and a constant anode voltage of said X-ray generator.
Claim 13
Dependent Claim
74 words
The combination of claim 1 wherein said X-ray tube of said X-ray generator operates with an anode current and an anode voltage, and wherein said control system means also comprise means for controlling the anode voltage of said X-ray tube to photograph only a limited area of the dental system so that areas outside of said limited area will not be photographed in order to minimize the radiation to which a patient is subjected.
Claim 14
Dependent Claim
100 words
The combination of claim 1 further including primary blind means associated with said tube head of said X-ray generator for adjusting the shape of a radiation beam generated by said tube head, and wherein said control system means are coupled to said primary blind means so that in order to minimize the radiation load to which the patient is subjected and wherein there is no need to photograph the patient over the full height of the picture, the primary blind means are controlled by the control system means to eliminate unnecessary portions of the X-ray beam in the horizontal direction.
Claim 15
Dependent Claim
34 words
The combination of claim 1 wherein said control system means are pre-programmed to cause said X-ray apparatus to photograph only selected areas of the patient, including regions of the salivary glands and maxillary sinuses.
Claim 16
Dependent Claim
51 words
The combination of claim 1 wherein said X-ray tube of said X-ray apparatus operates with an anode current and an anode voltage, and wherein said control system means also comprise means for controlling the anode voltage, the anode current and the exposure time of said X-ray tube for obtaining cephalostatic photographs.
Claim 17
Dependent Claim
38 words
The combination of claim 15 wherein said control system means also comprise means for adjusting said tube head so as to direct a X-ray beam to a correct position of a cephalostatic patient for obtaining the cephalostatic photographs.
Claim 18
Dependent Claim
62 words
The combination of claim 15 further including primary blind means associated with said tube head of said X-ray generator for adjusting the shape of a radiation beam generated by said tube head, and wherein said control system means are coupled to said primary blind means for adjustment of the shape of the radiation beam in accordance with the requirements of cephalostatic photography.
Claim 19
Dependent Claim
101 words
The combination of claim 1, wherein said control system means control the distribution of said speeds according to the formula v.sub.f =lr.sub.o /((l-r.sub.f +r.sub.o)r.sub.d)v.sub.d, wherein v f =the film transport motor speed, v d =the rotary motion motor speed, l=distance from a focal point of said X-ray tube to a plane of said X-ray film, r o =distance of the layer being photographed from an instantaneous center of rotation of said rotatable arm, r f =distance from the film plane to the instantaneous center of rotation, and r d =distance from a rotation drive point to the instantaneous center of rotation.
Claim 20
Dependent Claim
17 words
The combination of claim 1, wherein said control system means additionally control exposure time to remain constant.
Claim 21
Dependent Claim
33 words
The combination of claim 18, wherein said control system means additionally adjust said speeds in the same proportion, whereby the exposure time changes and the location of the layer being photographed remains constant.
Claim 22
Dependent Claim
60 words
The combination of claim 5, wherein said defining means comprise a blind board with said apertures formed therethrough, said position control means comprise a motor, and said positioning means comprise a threaded screw coupled to said position control motor and to said blind board, and a set of rollers upon which said blind board is supported for substantially horizontal movement.
Claim 23
Dependent Claim
67 words
The combination of claim 5, wherein said defining means comprise a substantially circular blind board with said apertures formed therethrough, said position control means comprise a motor, and said positioning means comprise a shaft upon which said blind board is rotatably mounted, teeth provided on an outer circumference of said blind board, and a threaded screw coupled to said positioning control motor and engaged with said teeth.
Claim 24
Dependent Claim
58 words
The combination of claim 4, wherein said aperature adjusting means comprise four blind boards, the edges of which define said aperature, and two threaded screws, each screw comprising two oppositely-threaded sections, with each of said blind boards threadingly engaged with a respective section, and said positioning control means comprise two motors, each motor coupled to a respective screw.
Claim 25
Dependent Claim
18 words
The combination of claim 16, wherein said tube head adjusting means comprise means for rotating said tube head.
References Cited (Backward Citations)
US4242585A
Cited
US4286162A
Cited
US4418419A
Cited
US4475224A
Cited
US4521899A
Cited
US4606063A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-11-08 | 1992-05-09 | 1992-11-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-11-08 | 1996-05-09 | 1996-11-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-11-08 | 2000-05-09 | 2000-11-08 | $7700.00 | Window Closed / Lapsed |