US3604938A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for operating electroluminescence display device
Assignee: Panasonic Holdings Corp
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Filing: 1969-04-29
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Granted: 1971-09-14
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Expires: 1989-04-29
Abstract
Abstract A method of operating an electroluminescent display device in which a unidirectional electric field of a predetermined direction is established across an electroluminescent layer comprising electroluminescent phosphor and glass enamel thereby to control the luminescence of said electroluminescent layer caused by excitation with an AC electric field.
Inventors
- 👤 Tadao Kohashi
- 👤 Kazunobu Tanaka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 20:32
CPC Classifications
H; H05; H05B; H05B33/00; H05B33/12; H05B44/00
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
142 words
A method of operating an electroluminescent display device comprising an electroluminescent layer containing powder of electroluminescent phosphor, said method comprising establishing an AC electric field across said electroluminescent layer to excite the electroluminescent layer and establishing a variable unidirectional electric field across said electroluminescent layer is superposed relationship to said AC electric field to control the luminescence caused by the AC excitation of said electroluminescent layer, said unidirectional electric field being established in such a manner that the luminous output takeout surface side of the electroluminescent layer is of negative polarity against the opposite side, and the maximum value of said variable unidirectional electric field is not less than the peak value of said AC electric field, so that when the incident energy to said energy sensitive layer increases or decreases, the luminescent output of the electroluminescent layer decreases or increases, respectively.
Claim 2
Independent Claim
142 words
A method of operating an electroluminescent display device comprising an electroluminescent layer containing powder of electroluminescent phosphor, said method comprising establishing an AC electric field across said electroluminescent layer to excite the electroluminescent layer and establishing a variable unidirectional electric field across said electroluminescent layer is superposed relationship to said AC electric field to control the luminescence caused by the AC excitation of said electroluminescent layer, said unidirectional electric field being established in such a manner that the luminous output takeout surface side of the electroluminescent layer is of negative polarity against the opposite side, and the maximum value of said variable unidirectional electric field is not less than the peak value of said AC electric field, so that when the incident energy to said energy sensitive layer increases or decreases, the luminescent output of the electroluminescent layer decreases or increases, respectively.
Claim 3
Dependent Claim
216 words
A method of operating an electroluminescent display device comprising an electroluminescent layer containing powder of electroluminescent phosphor, a first electrode capable of transmitting light and disposed on the luminous output takeout surface of said electroluminescent layer, an energy sensitive layer disposed on the other surface of said electroluminescent layer and a second electrode capable of transmitting an incident energy and disposed on the energy sensitive layer, said method comprising applying an AC voltage between said first and second electrodes to excite said electroluminescent layer and applying a unidirectional voltage between said first and second electrodes in superposed relationship to said AC voltage to control the luminescence caused by the AC excitation of said electroluminescent layer, said unidirectional voltage being applied in such a manner that the first electrode is of negative polarity, the second electrode is of positive polarity and said unidirectional voltage is not less than the peak value of the AC voltage across the electroluminescent layer so that when the incident energy to said energy sensitive layer increases or decrease, the luminescent output of the electroluminescent layer decreases or increases, respectively. 3 A method of operating an electroluminescent display device as set forth in claim 2, wherein said electroluminescent layer contains glass enamel for binding together said powder of electroluminescent phosphor which is ZnS:Cu.
Claim 4
Dependent Claim
27 words
A method of operating an electroluminescent display device as set forth in claim 3, wherein said glass enamel has a specific resistance of 106 to 109 ohm-cm.
Claim 5
Dependent Claim
24 words
A method of operating an electroluminescent display device as set forth in claim 2, wherein said energy sensitive layer is composed of photoconductive material.
Claim 6
Dependent Claim
24 words
A method of operating an electroluminescent display device as set forth in claim 2, wherein said energy sensitive layer is composed of magnetoresistive material.
Claim 7
Dependent Claim
24 words
A method of operating an electroluminescent display device as set forth in claim 2, wherein said energy sensitive layer is composed of piezoelectric material.
Claim 8
Dependent Claim
26 words
A method of operating an electroluminescent dIsplay device as set forth in claim 2, wherein said energy sensitive layer is composed of infrared quenching photoconductive material.
Claim 9
Independent Claim
192 words
A method of operating an electroluminescent display device comprising an electroluminescent layer containing powder of electroluminescent phosphor, a first electrode capable of transmitting light and disposed on the luminous output takeout surface of said electroluminescent layer, a resistive light-interception layer disposed on the other surface of said electroluminescent layer, an energy sensitive layer disposed on the light-interception layer and a second electrode capable of transmitting an incident energy and disposed on the energy sensitive layer, said method comprising applying an AC voltage between said first and second electrodes to excite said electroluminescent layer and applying a unidirectional voltage between said first and second electrodes in superposed relationship to said AC voltage to control the luminescence caused by the AC excitation of said electroluminescent layer, said unidirectional voltage being applied in such a manner that the first electrode is of negative polarity, the second electrode is of positive polarity, and said unidirectional voltage is not less than the peak value of the AC voltage across the electroluminescent layer so that when the incident energy to said energy sensitive layer increases or decreases, the luminescent output of said electroluminescent layer decreases or increases, respectively.
Claim 10
Independent Claim
192 words
A method of operating an electroluminescent display device comprising an electroluminescent layer containing powder of electroluminescent phosphor, a first electrode capable of transmitting light and disposed on the luminous output takeout surface of said electroluminescent layer, a resistive light-interception layer disposed on the other surface of said electroluminescent layer, an energy sensitive layer disposed on the light-interception layer and a second electrode capable of transmitting an incident energy and disposed on the energy sensitive layer, said method comprising applying an AC voltage between said first and second electrodes to excite said electroluminescent layer and applying a unidirectional voltage between said first and second electrodes in superposed relationship to said AC voltage to control the luminescence caused by the AC excitation of said electroluminescent layer, said unidirectional voltage being applied in such a manner that the first electrode is of negative polarity, the second electrode is of positive polarity, and said unidirectional voltage is not less than the peak value of the AC voltage across the electroluminescent layer so that when the incident energy to said energy sensitive layer increases or decreases, the luminescent output of said electroluminescent layer decreases or increases, respectively.
Claim 11
Dependent Claim
32 words
A method of operating an electroluminescent display device as set forth in claim 9, wherein said electroluminescent layer contains glass enamel for binding together said powder of electroluminescent phosphor which is ZnS:Cu.
Claim 12
Dependent Claim
27 words
A method of operating an electroluminescent display device as set forth in claim 9, wherein said glass enamel has a specific resistance of 106 to 109 ohm-cm.
Claim 13
Dependent Claim
24 words
A method of operating an electroluminescent display device as set forth in claim 9, wherein said energy sensitive layer is composed of photoconductive material.
Claim 14
Dependent Claim
26 words
A method of operating an electroluminescent display device as set forth in claim 9, wherein said energy sensitive layer is composed of infrared quenching photoconductive material.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-09-13 | 1975-03-15 | 1975-09-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-09-13 | 1979-03-15 | 1979-09-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-09-13 | 1983-03-15 | 1983-09-14 | $7700.00 | Window Closed / Lapsed |