Patent US4430746A successfully refreshed from Google Patents.
US4430746A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Tomograph for photographing entire jaws
Assignee: J Morita Manufaturing Corp
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Filing: 1981-06-23
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Granted: 1984-02-07
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Expires: 2001-06-23
Abstract
Abstract This disclosure relates to the improvement of a tomograph for photographing the entire jaws which is designed to make an X-ray photograph of a curved plane section of an object by changing the rotating output of a motor for driving a rotary arm by using an eccentric cam means to control a film feed speed by the rotary output thus change. This apparatus includes a tachogenerator for converting the rotating output of the rotary arm driving motor into an electric output, a voltage shunting means for shunting the output of the tachogenerator to three paths, a reference point correction circuit and a changeover resistance means, and is capable of providing a clear X-ray photograph of a patient in the range of adults to children without necessity to change the eccentric cams nor the position of the patient.
Inventors
- 👤 Masakazu Suzuki
- 👤 Toshiaki Ikeda
- 👤 Shuhei Furuichi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 12:08
CPC Classifications
A; A61; A61B; A61B6/00; A61B6/50; A61B6/51
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
326 words
A tomograph for photographing the entire jaws which is designed to photograph a curved plane section of an object which includes a rotary arm rotated by a rotary arm driving motor, said rotary arm having provided thereon an X-ray generator and an X-ray film feed means in an opposed relation with each other with the object positioned between the X-ray generator and the film feed means, said tomograph being characterized in that it comprises: an eccentric cam means predetermined in its configuration in accordance with said object to be photographed, said cam means being mounted at a suitable place of said rotary arm and adapted to be rotated in accordance with the rotation of said arm; a potentiometer cooperating with said eccentric cam, said potentiometer changing resistance in response to the rotation of said rotating arm; a tachogenerator directly connected to said rotary arm driving motor for generating an electromotive force; a voltage shunting means for dividing said electromotive force outputted from said tachogenerator into three paths and for deriving a reference point input voltage from a first path of said paths, for deriving a signal input voltage by applying a second path of said paths to the potentiometer and for deriving a presettable reference point correction voltage from a third path of said paths; a reference point correction circuit for subtracting said signal input voltage and reference point corection voltage; a V/F converter circuit receiving an additional output obtained by adding an output of said reference point correction circuit to said reference point input voltage and for generating a voltage pulse proportional to said additional output; a changeover resistance means for selectively changing said output of said reference correction circuit supplied to said V/F converter circuit; a pulse motor for driving said film feed means; and a pulse motor driving circuit receiving said voltage pulse outputted from said V/F converter circuit thereinto to thereby drive the film feed pulse motor for said film feed means.
Claim 2
Dependent Claim
326 words
A tomograph for photographing the entire jaws which is designed to photograph a curved plane section of an object which includes a rotary arm rotated by a rotary arm driving motor, said rotary arm having provided thereon an X-ray generator and an X-ray film feed means in an opposed relation with each other with the object positioned between the X-ray generator and the film feed means, said tomograph being characterized in that it comprises: an eccentric cam means predetermined in its configuration in accordance with said object to be photographed, said cam means being mounted at a suitable place of said rotary arm and adapted to be rotated in accordance with the rotation of said arm; a potentiometer cooperating with said eccentric cam, said potentiometer changing resistance in response to the rotation of said rotating arm; a tachogenerator directly connected to said rotary arm driving motor for generating an electromotive force; a voltage shunting means for dividing said electromotive force outputted from said tachogenerator into three paths and for deriving a reference point input voltage from a first path of said paths, for deriving a signal input voltage by applying a second path of said paths to the potentiometer and for deriving a presettable reference point correction voltage from a third path of said paths; a reference point correction circuit for subtracting said signal input voltage and reference point corection voltage; a V/F converter circuit receiving an additional output obtained by adding an output of said reference point correction circuit to said reference point input voltage and for generating a voltage pulse proportional to said additional output; a changeover resistance means for selectively changing said output of said reference correction circuit supplied to said V/F converter circuit; a pulse motor for driving said film feed means; and a pulse motor driving circuit receiving said voltage pulse outputted from said V/F converter circuit thereinto to thereby drive the film feed pulse motor for said film feed means.
References Cited (Backward Citations)
US4286163A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-02-06 | 1987-08-08 | 1988-02-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-02-06 | 1991-08-08 | 1992-02-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-02-06 | 1995-08-08 | 1996-02-07 | $7700.00 | Window Closed / Lapsed |