Patent US3920316A successfully refreshed from Google Patents.
US3920316A
Expired / Lapsed
US
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Electronic contour follower
Assignee: Compagnie de Signaux et dEntreprises Electriques SA
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Filing: 1974-01-03
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Granted: 1975-11-18
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Expires: 1994-01-03
Abstract
Abstract A contour follower is provided, wherein a line or contour to be followed is scanned with a circular scan by a reading head to produce a coincidence pulse each time the scan reaches the line. The circular scan is obtained by means of two coordinate drive systems controlled by drive signals derived from two sinewave signals which are 90* out of phase with one another. At each coincidence pulse, the scanning is stopped and the drive signals are stored and added to the previous signals which correspond to the origin of the scan with a view to obtain a motion of the circular scan along the line. Means are provided for comparing the coordinates of any two successive coincidence points in order to determine the slope of the contour and to start the application of the drive signals at one of four moments when their amplitude passes through a zero value. Each circular scan is thus started either in the first, the second, or third of the fourth quadrant, depending upon the slope of the line. Gating means are provided for avoiding that a circular scan may start before the information derived from the preceding scan has been processed.
Inventors
- 👤 Claude Daguillon
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 22:05
CPC Classifications
G; G06; G06K; G06K11/00; G06K11/02; G06K11/04
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
313 words
A contour follower for analyzing data supported on a bidimensional source of data, said contour follower comprising a reading head adapted to produce a coincidence output pulse each time the data read by the reading head lies within a predetermined range of values, actuator means coupled to the reading head for displacing the reading head relative to the source of data along two axes of coordinates, recorder means for recording the coordinates of the reading head for each of said coincidence pulses, said recorder means providing a status signal when ready to record new data after having recorded the coordinates of the reading head at each coincidence pulse, generator means having first and second outputs and adapted for providing on said outputs first and second sinewave signals having predetermined Phase-shift one relative to the other, first and second summing circuits each having first and second inputs and an output; first and second switching means respectively connecting the first and second outputs of the generator means to the respective first inputs of the first and second summing circuits, first and second storage means each having an input and an output, the respective inputs of the first and second storage means being connected to the respective outputs of the first and second summing circuits and the respective outputs of the first and second storage means being connected to the respective second inputs of the first and second summing circuits, the outputs of the summing circuits being connected to the actuator means, gating means connected to the storage means and to the reading head for controlling the storage of the respective sinewave signals into the storage means at each coincidence pulse, and control means adapted for closing said first and second switching means at each occurrence of a status signal and for opening said switching means after the sinewave signals have been stored into storage means.
Claim 2
Dependent Claim
313 words
A contour follower for analyzing data supported on a bidimensional source of data, said contour follower comprising a reading head adapted to produce a coincidence output pulse each time the data read by the reading head lies within a predetermined range of values, actuator means coupled to the reading head for displacing the reading head relative to the source of data along two axes of coordinates, recorder means for recording the coordinates of the reading head for each of said coincidence pulses, said recorder means providing a status signal when ready to record new data after having recorded the coordinates of the reading head at each coincidence pulse, generator means having first and second outputs and adapted for providing on said outputs first and second sinewave signals having predetermined Phase-shift one relative to the other, first and second summing circuits each having first and second inputs and an output; first and second switching means respectively connecting the first and second outputs of the generator means to the respective first inputs of the first and second summing circuits, first and second storage means each having an input and an output, the respective inputs of the first and second storage means being connected to the respective outputs of the first and second summing circuits and the respective outputs of the first and second storage means being connected to the respective second inputs of the first and second summing circuits, the outputs of the summing circuits being connected to the actuator means, gating means connected to the storage means and to the reading head for controlling the storage of the respective sinewave signals into the storage means at each coincidence pulse, and control means adapted for closing said first and second switching means at each occurrence of a status signal and for opening said switching means after the sinewave signals have been stored into storage means.
Claim 3
Dependent Claim
71 words
A contour follower according to claim 1, further comprising first and second comparator means for comparing the respective coordinates of the reading head which correspond to the successive coincidence pulses and further gating means controlled by the comparator means for enabling the control means to effect the closure of the switching means at one of the four times when the amplitude of each of the sinewave signals reaches a zero value.
Claim 4
Dependent Claim
138 words
A contour follower according to claim 2, wherein each of the said first and second comparator means and three outputs respectively validated when the coordinate XA, respectively YA, of the reading head which corresponds to a coincidence pulse is respectively equal, greater or smaller than the coordinate XB, respectively YB of the reading head which corresponds to the immediately succeeding coincidence pulse, the said outputs being connected to the said further gating means, the said further gating means having an output which is validated at one of the said four times, depending upon which of the following pairs of inequalities: XB > XA and YB < or = YA; YB < YA and XB < or = XA; XB < XA and YB > or = YA; YB > YA and XB > or = XA is verified.
Claim 5
Dependent Claim
106 words
A contour follower according to claim 2, wherein the said further gating means have an output, inputs connected to the respective outputs of the comparator means and further inputs adapted to receive manual control signals for the validation of the said output of the further gating means at one of the said four times, in the absence of signals on the outputs of the comparator means, the first and second summing circuits having each a third input and first and second sources of adjustable voltage being respectively connected to the third outputs of the first and second summing circuits for initial positioning of the reading head.
Claim 6
Dependent Claim
212 words
A contour follower according to claim 3, wherein each of first and second storage means comprise an analog-to-digital converter having an input connected to the output of the respective summing circuit, said analog-to-digital converter having an output, a digital-to-analog converter having an input, means connecting the output of the analog-to-digital converter to the input of the digital-to-analog converter, the digital-to-analog converter having an output connected to the second input of the respective summing circuit, the analog-to-digital converters each having a further output on which end-of-conversion signals are produced, the said control means including a first AND-gate having two inputs respectively connected to the further outputs of the respective analog-to-digital converters and an output, means connecting the output of the first AND-gate to the respectIve switching means for opening said switching means, a second AND-gate having an output, a first input connected to the output of the further gating means, a second input connected to the output of the first AND-gate and a third input, said recorder means having an output in which said status signal is produced, the third input of the second AND-gate being connected to said output of the recorder means and means connecting the output of the second AND-gate to the respective switching means for closing said switching means.
Claim 7
Dependent Claim
72 words
A contour follower according to claim 5, wherein each of analog-to-digital converter has a further input adapted for receiving start-of-conversion signals, an OR gate having an output connected to the said further inputs of the analog-to-digital converters, said OR-gate having first and second inputs, a clock generator connected to the first input of the OR-gate, the second input of the OR-gate being connected to the reading head for receiving the coincidence pulses.
Claim 8
Dependent Claim
74 words
A contour follower according to claim 6, wherein the means connecting each analog-to-digital converter to the corresponding digital-to-analog converter include a memory unit having an input connected to the output of the analog-to-digital converter, an output connected to the input of the digital-to-analog converter, and a further input adapted to receive transfer control signals, a delay element connecting the further output of each analog-to-digital converters to the further input of the respective memory unit.
Claim 9
Dependent Claim
78 words
A contour follower according to claim 7, wherein each comparator means includes a digital comparator having first and second inputs respectively connected to the input and to the output of the respective memory unit, and a further memory unit connected to said digital comparator, said further memory unit having the said three outputs and a control input, a further delay element connecting the further output of each analog-to-digital converter to the control input of each further memory unit.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-11-17 | 1979-05-19 | 1979-11-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-17 | 1983-05-19 | 1983-11-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-17 | 1987-05-19 | 1987-11-18 | $7700.00 | Window Closed / Lapsed |