US4011557A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Device in a time piece for feeding an electro-luminescent display
Assignee: Ebauches SA
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Filing: 1975-05-13
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Granted: 1977-03-08
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Expires: 1995-05-13
Abstract
Abstract It is known that an electro-luminescent display increases its light emitting efficiency with the current through it. Such a display in a watch run from a small battery, is fed by short impulses of high-intensity current by means of discharges from two capacitors which are alternately charged and discharged by transistor switches opened and closed by externally supplied impulses. The battery current is thus kept substantially constant and low. A series of digits or segments thereof, if used, may be fed in sequence with the impulses.
Inventors
- 👤 Fernand Chetelat
- 👤 Pierre Hersberger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 12:34
CPC Classifications
G; G04; G04G; G04G9/00; G04G9/08; G04G9/10; G04G9/102; G09; G09G; G09G3/00; G09G3/04; G09G3/06; G09G3/12; G09G3/14
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
89 words
A device for controlling a luminescent display having plural digits each composed of plural segments, comprising at least one current source, at least one capacitor, first switching means for controlling the charging of said capacitor from said source, and second switching means coupling said capacitor with said segments for controlling the subsequent discharge of said capacitor through a selected segment of a selected digit of said display, said switching action of said second switching means being repeated at a frequency such that the display appears continuous to the eye.
Claim 2
Independent Claim
89 words
A device for controlling a luminescent display having plural digits each composed of plural segments, comprising at least one current source, at least one capacitor, first switching means for controlling the charging of said capacitor from said source, and second switching means coupling said capacitor with said segments for controlling the subsequent discharge of said capacitor through a selected segment of a selected digit of said display, said switching action of said second switching means being repeated at a frequency such that the display appears continuous to the eye.
Claim 3
Dependent Claim
57 words
A device as recited in claim 1, including an additional current source and an additional capacitor, said two capacitors being alternatively charged from said two current sources by said first switching means in response to input pulses and discharged through said second switching means in the display segments, said second switching means comprising transistors used as switches.
Claim 4
Dependent Claim
42 words
A device as recited in claim 2, wherein said second switching means include a transistor for each digit adapted to be sequentially opened by pulses, and a transistor for each segment adapted to be opened by further pulses in a preselected sequence.
Claim 5
Dependent Claim
26 words
A device as recited in claim 1, including means coupled with said current source for varying the current charging said capacitor in response to ambient light.
Claim 6
Dependent Claim
15 words
A device as recited in claim 4, wherein said current varying means comprises a photoresistor.
Claim 7
Independent Claim
64 words
A device for feeding an electro-luminescent display with current pulses, comprising a current source, a pair of capacitors, and switching means coupled to said capacitors for controlling the charging and discharging thereof such that alternately each of said capacitors is charged from said source while the other is discharged through said display at a frequency such that the display appears continuous to the eye.
Claim 8
Independent Claim
64 words
A device for feeding an electro-luminescent display with current pulses, comprising a current source, a pair of capacitors, and switching means coupled to said capacitors for controlling the charging and discharging thereof such that alternately each of said capacitors is charged from said source while the other is discharged through said display at a frequency such that the display appears continuous to the eye.
Claim 9
Dependent Claim
23 words
A device as recited in claim 6, wherein said switching means comprises pulse controlled sources of current coupled with each of said capacitors.
Claim 10
Dependent Claim
14 words
A device as recited in claim 7, wherein said sources of current include transistors.
Claim 11
Dependent Claim
26 words
A device as recited in claim 6, including means coupled with said current source for varying the current charging said capacitor in response to ambient light.
Claim 12
Dependent Claim
15 words
A device as recited in claim 9, wherein said current varying means comprises a photoresistor.
Claim 13
Dependent Claim
56 words
A device as recited in claim 2, wherein said second switching means include a transistor for each digit adapted to be independently opened by pulses, and a transistor for each segment adapted to be independently opened by further pulses whereby pulses may be supplied to open said digit transistors only when corresponding segment transistors are open.
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) | 1980-03-07 | 1980-09-06 | 1981-03-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-03-07 | 1984-09-06 | 1985-03-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-03-07 | 1988-09-06 | 1989-03-08 | $7700.00 | Window Closed / Lapsed |