EP0273497A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Circuit for producing a periodic, essentially parabolic signal
Assignee: Koninklijke Philips NV
•
Filing: 1987-11-30
•
Granted: —
•
Expires: 2007-11-30
Abstract
Abstract A circuit for supplying a parabolic signal by squaring (1) a sawtooth-shaped signal. For eliminatinga disturbance occurring during the retrace period, a signal is generated (4) during this period whose polarity is opposite to that of the parabolic signal occurring during the trace period, both the generated signal and the derivative with respect to the time of this signal assuming values at the start and end of the retrace period which are substantially equal to the corresponding values at the same instants of the essentially parabolic signal occurring during the trace period and of the derivative with respect to the time of this signal.
Inventors
- 👤 Jozef Johannes Maria Hulshof
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-03 18:16
CPC Classifications
H; H03; H03K; H03K4/00; H03K4/04
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
166 words
A circuit for producing a periodic, essentially parabolic signal to an output terminal, this circuit comprising a squaring stage having an input for supplying a sawtooth-shaped signal having a trace and a retrace, the output signal of the squaring stage having the same frequency as the supplied sawtooth-shaped signal and having an essentially parabola-shaped variation during the trace period, characterized in that the circuit further comprises a signal generator for supplying to the output terminal during the retrace period a signal whose polarity is opposite to that of the essentially parabolic signal occurring during the trace period, the signal produced by the generator as well as the derivative with respect to the time of this signal assuming values at the beginning and at the end of the retrace period which are substantially equal to the value at the same instants of the essentially parabolic signal available at the output terminal during the trace period and of the derivative with respect to the time of this signal.
Claim 2
Dependent Claim
166 words
A circuit for producing a periodic, essentially parabolic signal to an output terminal, this circuit comprising a squaring stage having an input for supplying a sawtooth-shaped signal having a trace and a retrace, the output signal of the squaring stage having the same frequency as the supplied sawtooth-shaped signal and having an essentially parabola-shaped variation during the trace period, characterized in that the circuit further comprises a signal generator for supplying to the output terminal during the retrace period a signal whose polarity is opposite to that of the essentially parabolic signal occurring during the trace period, the signal produced by the generator as well as the derivative with respect to the time of this signal assuming values at the beginning and at the end of the retrace period which are substantially equal to the value at the same instants of the essentially parabolic signal available at the output terminal during the trace period and of the derivative with respect to the time of this signal.
Claim 3
Dependent Claim
55 words
A circuit as claimed in Claim 1, characterized by means for suppressing a signal generated by the squaring stage during the retrace period and by means for conveying to the output terminal an essentially parabolic signal occurring during the trace period as well as the signal produced by the signal generator during the retrace period.
Claim 4
Dependent Claim
42 words
A circuit as claimed in Claim 1, characterized by an adjusting stage for converting and adjusting the amplitude of an essentially parabolic signal produced by the squaring stage during the retrace period and for conveying the obtained signal to the output terminal.
Claim 5
Dependent Claim
18 words
A circuit as claimed in Claim 2, characterized in that the signal from the signal generator is sine-shaped.
Claim 6
Dependent Claim
21 words
A circuit as claimed in Claim 4, characterized in that the frequency, phase and amplitude of the sine-shaped signal are adjustable.
Claim 7
Dependent Claim
69 words
A circuit as claimed in Claim 4, characterized in that the period of the sine-shaped signal is twice as long as the retrace period, a starting circuit being coupled to the signal generator for determining the values of the sine-shaped signal and of the drivative with respect to the time of this signal at the beginning of the retrace period and for conveying these values to the signal generator.
Claim 8
Dependent Claim
61 words
A circuit as claimed in Claim 6, characterized in that the squaring stage is coupled to the starting circuit for conveying at the beginning of the retrace period the values of the basically parabolic signal and of the derivative with respect to the time of this signal at the end of the trace period as initial values of the sine-shaped signal.
Claim 9
Dependent Claim
123 words
A circuit as claimed in Claim 7, characterized in that the starting circuit comprises an amplifier, an inverting input of which is coupled to the squaring stage via a first capacitor and a non-inverting input of which is coupled to the squaring stage via a first resistor for supplying the essentially parabolic signal occurring during the trace period, a second resistor being connected between the inverting input and an output of the amplifier, this output being coupled to the signal generator via a switch conducting during the trace period and being blocked during the retrace period, a second capacitor being connected to the non-inverting input of the amplifier, both capacitors having substantially the same capacitance and both resistors having substantially the same value.
Claim 10
Dependent Claim
67 words
A circuit as claimed in Claim 7, characterized in that the starting circuit comprises a resistor, one connection of which is coupled to the squaring stage for supplying the essentially parabolic signal occurring during the trace period, the other connections of the resistor being coupled to a switch coupled to the signal generator, this switch conducting during the trace period and being blocked during the retrace period.
Claim 11
Dependent Claim
56 words
A circuit as claimed in Claims 8 and 9, characterized in that the signal generator comprises a capacitor connected to the switch, the voltage across the capacitor at the beginning of the retrace period having information about the initial values of the generator signal and about the derivative with respect to the time of this signal.
Claim 12
Dependent Claim
33 words
A circuit as claimed in Claim 4, characterized in that the signal generator is a start-stop-oscillator operative at the beginning of the retrace period and inoperative at the end of the retrace period.
Claim 13
Dependent Claim
67 words
A circuit as claimed in Claim 11, characterized in that the start-stop-oscillator comprises an amplifier, a selective network short-circuited during the retrace period being connected between a feedback input and an output of the amplifier, this output forming the output terminal of the circuit, a further input of the amplifier being coupled to the squaring stage for supplying the essentially parabolic signal occurring during the trace period.
Claim 14
Dependent Claim
129 words
A circuit as claimed in Claim 4, characterized by a series arrangement comprising a first capacitor, a current source, a self-inductance and a second capacitor, this series arrangement being coupled to the squaring stage for supplying the essentially parabolic signal occurring during the trace period, a first switch blocked during the trace period and conducting during the retrace period being connected in parallel with the series arrangement composed of the first capacitor and the current source, a second switch conducting during the trace period and blocked during the retrace period being connected in parallel with the arrangement composed of the second capacitor, the current source and the self-inductance, and the junction point of the self-inductance, the second capacitor and the second switch forming the output terminal of the circuit.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.