US5336977A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Emergency lighting device
Assignee: Individual
•
Filing: 1993-05-18
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Granted: 1994-08-09
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Expires: 2013-05-18
Abstract
Abstract An emergency lighting device includes a hollow casing, a magnetic field detecting unit, a lamp unit and a driving unit. The casing is positioned adjacent to an electric outlet. The magnetic field detecting unit is disposed inside the casing and detects the absence of a magnetic field from the electric outlet. The lamp unit is mounted operatively on the casing. The driving unit is disposed inside the casing and is connected electrically to the lamp unit and to the detecting unit. The driving unit includes a light-sensitive switch unit and is responsive to the detecting unit so as to activate the lamp unit only when the magnetic field from the electric outlet is absent and there is weak surrounding light.
Inventors
- 👤 Ming-Chun Li
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 16:28
CPC Classifications
H; H02; H02J; H02J9/00; H02J9/02; H05; H05B; H05B47/00; H05B47/10; H05B47/105; H05B47/11; Y; Y02; Y02B; Y02B10/00; Y02B10/70; Y02B20/00; Y02B20/40
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
103 words
An emergency lighting device, comprising: a hollow casing positioned adjacent to an electric outlet; a magnetic field detecting unit disposed inside said casing, said detecting unit detecting the absence of a magnetic field from said electric outlet; a lamp unit mounted operatively on said casing; and a driving unit disposed inside said casing and connected electrically to said lamp unit and said detecting unit, said driving unit including a light-sensitive switch unit and being responsive to said detecting unit so as to activate said lamp unit only when said magnetic field from said electric outlet is absent and there is weak surrounding light.
Claim 2
Dependent Claim
103 words
An emergency lighting device, comprising: a hollow casing positioned adjacent to an electric outlet; a magnetic field detecting unit disposed inside said casing, said detecting unit detecting the absence of a magnetic field from said electric outlet; a lamp unit mounted operatively on said casing; and a driving unit disposed inside said casing and connected electrically to said lamp unit and said detecting unit, said driving unit including a light-sensitive switch unit and being responsive to said detecting unit so as to activate said lamp unit only when said magnetic field from said electric outlet is absent and there is weak surrounding light.
Claim 3
Dependent Claim
70 words
An emergency lighting device as claimed in claim 1, further comprising a power supply assembly installed operatively on said casing, said power supply assembly including a rechargeable battery unit for providing electric power to said emergency lighting device, and a solar energy converter unit which is connected operatively to said rechargeable battery unit so as to convert solar energy into electric energy in order to charge said rechargeable battery unit.
Claim 4
Dependent Claim
38 words
An emergency lighting device as claimed in claim 1, further comprising a seat which can be mounted on a predetermined position adjacent to said electric outlet and which has a receiving space for receiving removably said casing therein.
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) | 1997-08-08 | 1998-02-07 | 1998-08-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-08-08 | 2002-02-07 | 2002-08-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-08-08 | 2006-02-07 | 2006-08-09 | $7700.00 | Window Closed / Lapsed |