X-ray or gamma ray systems or devices – Specific application – Diffraction – reflection – or scattering analysis
Patent
1989-01-13
1989-10-03
Church, Craig E.
X-ray or gamma ray systems or devices
Specific application
Diffraction, reflection, or scattering analysis
378 91, 318620, G03B 4202
Patent
active
048721905
ABSTRACT:
A system and method is disclosed for minimizing residual vibration of a radiographic system due to rapid movement of a radiographic film cassette between a park and expose position. The cassette is moved by a servo system including a servo motor which is responsive to a voltage input waveform to drive the cassette. A waveform is chosen for the voltage input such that no impulse derivatives appear until the waveform has been differentiated at least three times. The primary natural resonant frequency of the system is determined and noted. The duration of the selected input waveform is adjusted such that the frequency spectrum of the adjusted input waveform defines a relative null which approximately coincides with the primary resonant frequency. The amplitude of the voltage input waveform is then further adjusted as a function of the distance to be traveled by the cassette between the park and expose positions. The servo system can optionally be operated over a portion of the cassette transit in a closed loop fashion. In a mechanical embodiment, sinusoidal cassette acceleration can be effected by the use of a mechanical drive linkage coupled between a motor and the cassette, the drive linkage employing a cycloidal cam and associated cam follower to govern the profile of cassette movement.
REFERENCES:
patent: 2668913 (1954-02-01), Goldfield et al.
patent: 2749445 (1956-06-01), Stava et al.
patent: 2767323 (1956-10-01), Stava et al.
patent: 2834890 (1958-05-01), Bastin et al.
patent: 3173008 (1965-03-01), Barrett et al.
patent: 3862426 (1975-01-01), Thomas
patent: 4051423 (1977-09-01), Touchton et al.
patent: 4105920 (1978-08-01), Pury et al.
patent: 4357538 (1982-11-01), Hunt et al.
patent: 4464779 (1984-08-01), Finkenzeller et al.
patent: 4651337 (1987-03-01), Boomgaarden et al.
patent: 4679223 (1987-07-01), Ohlson et al.
Terman, F. E., Radio Engineers' Handbook, 1st Ed., 2nd Impression, McGraw-Hill, New York, 1943, pp. 20, 21.
Kramer, S. N., "Development of the Variable-Rate Transymmetric Motion with Discretely Vanishing Shock", ASME Paper 83-DET-39, Jun. 10, 1983.
Tesar, D. et al, "The Dynamic Synthesis, Analysis, and Design of Modeled Cam Systems", D. C. Heath and Company, Lexington, Massachusetts, 1976.
Matthew, G. K., et al, "Formalized Matrix Method of Nth Derivative Trapezoidal Motion Specifications for Cams", the Third World Congress for the Theory of Machines and Mechanisms, vol. H, Paper H-19, Kupari, Yugoslavia, Sep. 1971, pp. 247-260.
Everett Dennis
Flanagan Patrick M.
Geither John
Hrdlicka Victor
Stojkov Mark
Church Craig E.
Picker International Inc.
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