US3715487A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Parabola generator moving error corrector
Assignee: General Electric Co
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Filing: 1971-10-29
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Granted: 1973-02-06
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Expires: 1991-10-29
Abstract
Abstract A circuit for producing a parabola waveform which comprises a differential input integrator receiving a ramp waveform at a first input and employs a feedback circuit including a peak detector connected to its second input. Any departure of the vertical rate parabola from steady-state conditions, caused by introducing a DC component into the first input, is thus detected in the form of an error voltage at the second input of the integrator, thereby cancelling out the DC component to prevent its having any effect on the output signal.
Inventors
- 👤 J Blake
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 08:24
CPC Classifications
H; H03; H03K; H03K4/00; H03K4/04; H04; H04N; H04N5/00; H04N5/222; H04N5/262; H04N5/272; H04N5/275
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
163 words
In a television system, apparatus for switching video signals in a raster scan on a display screen, said apparatus comprising a source of a repetitive AC scanning waveform normally having no DC component, to reference the time of switching of said video signals, variable control means for at will modifying a parameter of said waveform to displace the time of switching of said video signals from the reference time, the modification adding an undesirable DC component to said waveform thereby causing an error in the time displacement of said switching, means responsive to said waveform, including any said modification thereof, for integration thereof to produce switching signals for said video signals, means responsive to a component of the integrated waveform attributable to any said undesirable DC component added by said modification of the original waveform, for developing an inverted version of said DC component, and feedback means for adding said inverted version to the modified waveform to cancel the undesirable DC component therefrom.
Claim 2
Dependent Claim
163 words
In a television system, apparatus for switching video signals in a raster scan on a display screen, said apparatus comprising a source of a repetitive AC scanning waveform normally having no DC component, to reference the time of switching of said video signals, variable control means for at will modifying a parameter of said waveform to displace the time of switching of said video signals from the reference time, the modification adding an undesirable DC component to said waveform thereby causing an error in the time displacement of said switching, means responsive to said waveform, including any said modification thereof, for integration thereof to produce switching signals for said video signals, means responsive to a component of the integrated waveform attributable to any said undesirable DC component added by said modification of the original waveform, for developing an inverted version of said DC component, and feedback means for adding said inverted version to the modified waveform to cancel the undesirable DC component therefrom.
Claim 3
Dependent Claim
163 words
In a television system, apparatus for switching video signals in a raster scan on a display screen, said apparatus comprising a source of a repetitive AC scanning waveform normally having no DC component, to reference the time of switching of said video signals, variable control means for at will modifying a parameter of said waveform to displace the time of switching of said video signals from the reference time, the modification adding an undesirable DC component to said waveform thereby causing an error in the time displacement of said switching, means responsive to said waveform, including any said modification thereof, for integration thereof to produce switching signals for said video signals, means responsive to a component of the integrated waveform attributable to any said undesirable DC component added by said modification of the original waveform, for developing an inverted version of said DC component, and feedback means for adding said inverted version to the modified waveform to cancel the undesirable DC component therefrom.
Claim 4
Dependent Claim
163 words
In a television system, apparatus for switching video signals in a raster scan on a display screen, said apparatus comprising a source of a repetitive AC scanning waveform normally having no DC component, to reference the time of switching of said video signals, variable control means for at will modifying a parameter of said waveform to displace the time of switching of said video signals from the reference time, the modification adding an undesirable DC component to said waveform thereby causing an error in the time displacement of said switching, means responsive to said waveform, including any said modification thereof, for integration thereof to produce switching signals for said video signals, means responsive to a component of the integrated waveform attributable to any said undesirable DC component added by said modification of the original waveform, for developing an inverted version of said DC component, and feedback means for adding said inverted version to the modified waveform to cancel the undesirable DC component therefrom.
Claim 5
Dependent Claim
35 words
In the television system of claim 1, said variable control means comprising a control lever movable in a plurality of different directions to correspondingly vary the position of a geometric pattern of the television raster.
Claim 6
Dependent Claim
31 words
In the television system of claim 1, said means for developing an inverted version of said DC component comprising an inverter, a peak detector, and a filter, in the order recited.
Claim 7
Dependent Claim
147 words
A source of a recurrence ramp input waveform normally having a zero DC signal component, means for integrating said ramp input waveform to produce a recurrent parabolic output waveform, positioner means for modifying the time of occurrence of the ramp in said recurrent ramp input waveform to modify the time of occurrence of the parabola in said produced recurrent parabolic output waveform, said ramp duration modification producing an undesirable ramp component in said modified parabolic output waveform, means for inverting said modified parabolic output waveform to produce an inverted, modified parabolic output waveform, means for peak detecting said inverted, modified parabolic output waveform, means for applying said inverted, modified parabolic output waveform as a negative feedback signal to said means for integrating to provide a desirable output signal comprising said modified parabolic output waveform without said undesirable ramp component, and means for utilizing said desirable output waveform.
Claim 8
Dependent Claim
147 words
A source of a recurrence ramp input waveform normally having a zero DC signal component, means for integrating said ramp input waveform to produce a recurrent parabolic output waveform, positioner means for modifying the time of occurrence of the ramp in said recurrent ramp input waveform to modify the time of occurrence of the parabola in said produced recurrent parabolic output waveform, said ramp duration modification producing an undesirable ramp component in said modified parabolic output waveform, means for inverting said modified parabolic output waveform to produce an inverted, modified parabolic output waveform, means for peak detecting said inverted, modified parabolic output waveform, means for applying said inverted, modified parabolic output waveform as a negative feedback signal to said means for integrating to provide a desirable output signal comprising said modified parabolic output waveform without said undesirable ramp component, and means for utilizing said desirable output waveform.
Claim 9
Dependent Claim
92 words
An arrangement for processing a recurrent ramp waveform whose starting time of occurrence is modifiable comprising means for integrating said ramp waveform to produce a recurrent parabolic waveform, means for substantially eliminating an undesirable ramp component in said recurrent parabolic waveform resulting during changes in said starting time comprising means for inverting a portion of said parabolic waveform with said undesirable ramp component to provide an inverted waveform, means for peak detecting said inverted waveform, and means for applying said inverted waveform as a negative feedback signal to said means for integrating.
Claim 10
Dependent Claim
92 words
An arrangement for processing a recurrent ramp waveform whose starting time of occurrence is modifiable comprising means for integrating said ramp waveform to produce a recurrent parabolic waveform, means for substantially eliminating an undesirable ramp component in said recurrent parabolic waveform resulting during changes in said starting time comprising means for inverting a portion of said parabolic waveform with said undesirable ramp component to provide an inverted waveform, means for peak detecting said inverted waveform, and means for applying said inverted waveform as a negative feedback signal to said means for integrating.
Claim 11
Dependent Claim
21 words
An arrangement according to claim 5 further comprising means for filtering said inverted waveform before application to said means for integrating.
References Cited (Backward Citations)
US3484594A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-02-06 | 1976-08-07 | 1977-02-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-02-06 | 1980-08-07 | 1981-02-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-02-06 | 1984-08-07 | 1985-02-06 | $7700.00 | Window Closed / Lapsed |