US3908150A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electroluminescent display and method for driving the same
Assignee: Sigmatron Nova Inc
•
Filing: 1973-10-01
•
Granted: 1975-09-23
•
Expires: 1993-10-01
Abstract
Abstract An electroluminescent display utilizing a capacitive display device. The display has an inherent minimum useful illumination term, during which it must be illuminated in order to be seen by an observer. The display is driven (actuated), so as to be illuminated, by pulses of actuating alternating current, and there will be more than one of these pulses during each said minimum useful illumination term. The pulse term, or duration, of the individual pulses is shorter than the pulse interval. The pulses may be shaped so as most efficiently to transfer energy to the display. The driving system improves the efficiency and lengthens the life of single displays, and permits higherintensity operation of multiple displays. A useful driving system includes a pulse transformer which produces the desired actuating current when it is itself pulsed.
Inventors
- 👤 Robert D Webb
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 20:35
CPC Classifications
H; H05; H05B; H05B44/00; Y; Y02; Y02B; Y02B20/00; Y02B20/30
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
166 words
An electroluminescent display system comprising: a capacitive electroluminescent diaplay having a pair of electrodes and an electroluminescent layer therebetween, the display having an inherent minimum useful illumination term for which term it must be actuated in order to be observed as an illuminated surface, and during which alternating current of voltage at least equal to a minimum actuating voltage necessary to cause visible illumination is applied thereto in order to create a luminous surface; a source of such alternating current having an output frequency such that the period of three of its cycles is less than the said minimum illumination term; and means for periodically and intermittently applying said alternating current to said electrodes in pulses, each pulse containing a number of contributing cycles of such amplitude as to contribute a significant increment of increased luminosity, the pulses being applied with such frequency that said contributing cycles are applied for actuation for a total time of less than about 25% of said minimum useful illumination term.
Claim 2
Dependent Claim
166 words
An electroluminescent display system comprising: a capacitive electroluminescent diaplay having a pair of electrodes and an electroluminescent layer therebetween, the display having an inherent minimum useful illumination term for which term it must be actuated in order to be observed as an illuminated surface, and during which alternating current of voltage at least equal to a minimum actuating voltage necessary to cause visible illumination is applied thereto in order to create a luminous surface; a source of such alternating current having an output frequency such that the period of three of its cycles is less than the said minimum illumination term; and means for periodically and intermittently applying said alternating current to said electrodes in pulses, each pulse containing a number of contributing cycles of such amplitude as to contribute a significant increment of increased luminosity, the pulses being applied with such frequency that said contributing cycles are applied for actuation for a total time of less than about 25% of said minimum useful illumination term.
Claim 3
Dependent Claim
35 words
A display system according to claim 1 in which said means applies to contributing cycles to the electrodes for a total period between about 0.1% and about 25% of the said minimum useful illumination term.
Claim 4
Dependent Claim
23 words
A display system according to claim 1 in which the number of said contributing cycles in each pulse is less than about twenty.
Claim 5
Dependent Claim
32 words
A display system according to claim 1 in which the number of contributing cycles in each pulse is such that each contributing cycle contributes a substantially equal increment of increase in luminosity.
Claim 6
Dependent Claim
23 words
A display system according to claim 4 in which the number of said contributing cycles in each pulse is less than about five.
Claim 7
Dependent Claim
35 words
A display system according to claim 3 in which said means applies said contributing cycles to the electrodes for a total period between about 0.1% and about 25% of the said minimum useful illumination term.
Claim 8
Dependent Claim
35 words
A display system according to claim 4 in which said means applies said contributing cycles to the electrodes for a total period between about 0.1% and about 25% of the said minimum useful illumination term.
Claim 9
Dependent Claim
35 words
A display system according to claim 5 in which said means applies said contributing cycles to the elEctrodes for a total period between about 0.1% and about 25% of the said minimum useful illumination term.
Claim 10
Dependent Claim
18 words
A display system according to claim 1 in which the source of alternating current is a pulse transformer.
Claim 11
Independent Claim
121 words
A method of illuminating a capacitive electroluminescent display having a pair of electrodes and an electroluminescent layer therebetween, said display having as an inherent property the actuation to vilible luminosity as a consequence of the application across the electrodes of an alternating current having a voltage and frequency sufficient to produce the luminosity, said method comprising applying said alternating current in pulses, said pulses each comprising contributing cycles in number such that each cycle contributes a significant increment of luminosity, the frequency of supplying said pulses being such that the said contributing cycles occupy less than about 25% of the inherent minimum useful illumination term for which the display must be actuated in order to be observed as an illuminated surface.
Claim 12
Independent Claim
121 words
A method of illuminating a capacitive electroluminescent display having a pair of electrodes and an electroluminescent layer therebetween, said display having as an inherent property the actuation to vilible luminosity as a consequence of the application across the electrodes of an alternating current having a voltage and frequency sufficient to produce the luminosity, said method comprising applying said alternating current in pulses, said pulses each comprising contributing cycles in number such that each cycle contributes a significant increment of luminosity, the frequency of supplying said pulses being such that the said contributing cycles occupy less than about 25% of the inherent minimum useful illumination term for which the display must be actuated in order to be observed as an illuminated surface.
Claim 13
Dependent Claim
30 words
A method according to claim 10 in which the said contributing cycles are applied to the electrodes for between about 0.1% and about 25% of said minimum useful illumination term.
Claim 14
Dependent Claim
22 words
A method according to claim 10 in which the number of said contributing cycles in each pulse is less than about twenty.
Claim 15
Dependent Claim
31 words
A method according to claim 10 in which the number of contributing cycles in each pulse is such that each contributing cycle contributes a substantially equal increment of increase in luminosity.
Claim 16
Dependent Claim
21 words
A method according to claim 13 in which the number of contributing cycles in each pulse is less than about five.
Claim 17
Dependent Claim
35 words
A method according to claim 12 in which said means applies said contributing cycles to to the electrodes for a total period between about 0.1% and about 25% of the said minimum useful illumination term.
Claim 18
Dependent Claim
34 words
A method according to claim 13 in which said means applies said contributing cycles to the electrodes for a total period between about 0.1% and about 25% of the said minimum useful illumination term.
Claim 19
Dependent Claim
34 words
A method according to claim 14 in which said means applies said contributing cycles to the electrodes for a total period between about 0.15% and about 25% of the said minimum useful illumination term.
Claim 20
Dependent Claim
17 words
A method according to claim 10 in which each pulse comprises a train of ringing contributing cycles.
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) | 1978-09-22 | 1979-03-24 | 1979-09-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-22 | 1983-03-24 | 1983-09-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-22 | 1987-03-24 | 1987-09-23 | $7700.00 | Window Closed / Lapsed |