US4595920A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Low-loss sinusoidal drive system and technique
Assignee: Boeing North American Inc
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Filing: 1983-08-17
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Granted: 1986-06-17
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Expires: 2003-08-17
Abstract
Abstract A low-loss sinusoidal drive system is disclosed for powering thin-film electroluminescent displays (TFEL). A DC power source coupled through a DC-to-AC inverter and driving an LC resonant tank circuit is used to produce a sinusoidal supply voltage. The sinusoidal supply voltage is coupled to produce a sinusoidal backplane driving voltage and coupled to a synchronizer circuit which controls drive logic for selectively energizing segments of the TFEL display. The drive logic is coupled to respond to an on-off command for selecting a particular segment such that the average DC voltage across a segment of the TFEL is zero, independent of the on/off condition of the segment. The backplane sinusoidal voltage may be applied in common to multiple TFEL devices with the synchronizing and drive logic circuits individually selecting the segments for TFEL drive.
Inventors
- 👤 Wesley G. Runyan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 14:57
CPC Classifications
G; G09; G09G; G09G3/00; G09G3/04; G09G3/06; G09G3/12
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
90 words
A method for driving thin-film electroluminescent displays comprising: generating an alternating signal and providing an output thereof; coupling said alternating signal output to an inductance-capacitance resonant tank circuit to produce and maintain a resonant sinusoidal output; coupling said resonant sinusoidal output to the backplane electrode of a thin-film electroluminescent display having a backplane electrode and a plurality of segment electrodes by coupling said electroluminescent display in electrical parallel with the capacitance of said resonant tank circuit; and controlling each of said plurality of segments to selectively produce a luminous display.
Claim 2
Independent Claim
90 words
A method for driving thin-film electroluminescent displays comprising: generating an alternating signal and providing an output thereof; coupling said alternating signal output to an inductance-capacitance resonant tank circuit to produce and maintain a resonant sinusoidal output; coupling said resonant sinusoidal output to the backplane electrode of a thin-film electroluminescent display having a backplane electrode and a plurality of segment electrodes by coupling said electroluminescent display in electrical parallel with the capacitance of said resonant tank circuit; and controlling each of said plurality of segments to selectively produce a luminous display.
Claim 3
Dependent Claim
89 words
A power supply and drive system for a display comprising: a display element having a common backplane electrode and a plurality of individual segment eletrodes; means for producing and maintaining a resonating sinusoidal output signal from an inductance-capacitance resonant tank circuit and coupling said output signal to said backplane electrode by coupling said display element in electrical parallel with the capacitance of said tank circuit; and means for applying control signals to selected ones of said plurality of segment electrodes for causing said selected segment electrodes to become luminous.
Claim 4
Dependent Claim
89 words
A power supply and drive system for a display comprising: a display element having a common backplane electrode and a plurality of individual segment eletrodes; means for producing and maintaining a resonating sinusoidal output signal from an inductance-capacitance resonant tank circuit and coupling said output signal to said backplane electrode by coupling said display element in electrical parallel with the capacitance of said tank circuit; and means for applying control signals to selected ones of said plurality of segment electrodes for causing said selected segment electrodes to become luminous.
Claim 5
Dependent Claim
30 words
The system of claim 2 wherein said means for providing a sinusoidal resonant signal comprises a DC-AC inverter coupled to an inductance-capacitance tank circuit to cause said sinusoidal resonant output.
Claim 6
Dependent Claim
38 words
The system of claim 2 wherein said means for controlling comprises means for causing an alternating signal across the selected segment electrode to produce illumination so that there is no DC offset signal applied to the display element.
Claim 7
Dependent Claim
14 words
The system of claim 2 wherein said display element is a thin-film electroluminescent display.
Claim 8
Dependent Claim
38 words
The system of claim 2 wherein said means for applying control signals includes a digital logic control circuit coupled to receive digital inputs and produce a control signal to a segment electrode in response to said digital inputs.
Claim 9
Dependent Claim
120 words
A thin-film electroluminescent display system comprising: a thin-film electroluminescent display having a backplane electrode and a plurality of segment electrodes which may be selectively controlled to form a luminous display; a DC-AC inverter for providing an alternating signal output; an inductance-capacitance tank circuit coupled to receive the alternating signal output of said DC-AC inverter and produce a resonant sinusoidal output; means responsive to said resonant sinusoidal output for controlling said DC-AC inverter to maintain resonance of said resonant sinusoidal output, said resonant sinusoidal output being coupled to said backplane electrode by coupling said electroluminescent display in electrical parallel with the capacitance of said tank circuit; and means for selectively controlling the plurality of segment electrodes for producing a luminous display.
Claim 10
Dependent Claim
120 words
A thin-film electroluminescent display system comprising: a thin-film electroluminescent display having a backplane electrode and a plurality of segment electrodes which may be selectively controlled to form a luminous display; a DC-AC inverter for providing an alternating signal output; an inductance-capacitance tank circuit coupled to receive the alternating signal output of said DC-AC inverter and produce a resonant sinusoidal output; means responsive to said resonant sinusoidal output for controlling said DC-AC inverter to maintain resonance of said resonant sinusoidal output, said resonant sinusoidal output being coupled to said backplane electrode by coupling said electroluminescent display in electrical parallel with the capacitance of said tank circuit; and means for selectively controlling the plurality of segment electrodes for producing a luminous display.
Claim 11
Dependent Claim
37 words
The system of claim 7 wherein said inductance-capacitance tank circuit comprises an inductor and a capacitor coupled to provide said resonant sinusoidal signal at a common terminal therebetween, said backplane electrode being coupled to said common terminal.
Claim 12
Dependent Claim
21 words
The system of claim 8 wherein said capacitance is at least ten times the inherent capacitance of the thin-film electroluminescent display.
Claim 13
Dependent Claim
25 words
The system of claim 8 further comprising means coupled to said common terminal for controlling said DC-AC inverter to maintain resonance of said sinusoidal signal.
Claim 14
Dependent Claim
28 words
The system of claim 7 wherein said means for selectively controlling comprises a digital logic circuit responsive to digital inputs for selecting the segment electrode to be illuminated.
Claim 15
Dependent Claim
38 words
The system of claim 7 wherein said means for selectively controlling is coupled to drive said segment electrodes so that there is a zero net DC offset signal between the segment electrodes and backplane electrode at all times.
Claim 16
Dependent Claim
108 words
A power supply and drive system for a display comprising: a display element having a common backplane electrode and a plurality of individual segment electrodes; means for producing and maintaining a resonating sinusoidal output signal from an inductance-capacitance resonant tank circuit and coupling said output signal to said backplane electrode; and means for applying control signals to selected ones of said plurality of segment electrodes to cause said selected segment electrodes to become luminous, said means for applying control signals comprising means for causing an alternating signal across the selected segment eletrode to produce illumination so that there is no DC offset signal applied to the display element.
Claim 17
Dependent Claim
108 words
A power supply and drive system for a display comprising: a display element having a common backplane electrode and a plurality of individual segment electrodes; means for producing and maintaining a resonating sinusoidal output signal from an inductance-capacitance resonant tank circuit and coupling said output signal to said backplane electrode; and means for applying control signals to selected ones of said plurality of segment electrodes to cause said selected segment electrodes to become luminous, said means for applying control signals comprising means for causing an alternating signal across the selected segment eletrode to produce illumination so that there is no DC offset signal applied to the display element.
Claim 18
Dependent Claim
130 words
A thin-film electroluminescent display system comprising: a thin-film electroluminescent display having a backplane electrode and a plurality of segment electrodes which may be selectively controlled to form a luminous display; a DC-AC inverter for providing an alternating signal output; an inductance-capacitance tank circuit coupled to receive the alternating signal output of said DC-AC inverter and produce a resonant sinusoidal output; means responsive to said resonant sinusoidal output for controlling said DC-AC inverter to maintain resonance of said resonant sinusoidal output, said resonant sinusoidal output being coupled to said backplane electrode; and means for selectively controlling the plurality of segment electrodes to produce a luminous display by driving said segment electrodes so that there is a zero net DC offset signal between the segment electrodes and backplane electrode at all times.
Claim 19
Dependent Claim
130 words
A thin-film electroluminescent display system comprising: a thin-film electroluminescent display having a backplane electrode and a plurality of segment electrodes which may be selectively controlled to form a luminous display; a DC-AC inverter for providing an alternating signal output; an inductance-capacitance tank circuit coupled to receive the alternating signal output of said DC-AC inverter and produce a resonant sinusoidal output; means responsive to said resonant sinusoidal output for controlling said DC-AC inverter to maintain resonance of said resonant sinusoidal output, said resonant sinusoidal output being coupled to said backplane electrode; and means for selectively controlling the plurality of segment electrodes to produce a luminous display by driving said segment electrodes so that there is a zero net DC offset signal between the segment electrodes and backplane electrode at all times.
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) | 1989-06-16 | 1989-12-16 | 1990-06-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-06-16 | 1993-12-16 | 1994-06-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-06-16 | 1997-12-16 | 1998-06-17 | $7700.00 | Window Closed / Lapsed |