Patent US4517496A successfully refreshed from Google Patents.
US4517496A
Expired / Lapsed
US
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Lighting apparatus for a discharge lamp
Assignee: Mitsubishi Electric Corp
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Filing: 1982-03-02
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Granted: 1985-05-14
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Expires: 2002-03-02
Abstract
Abstract A lighting apparatus for a discharge lamp in which said lighting apparatus (4) is coupled in series with a discharge lamp (3), said lighting apparatus (4) is composed of a capacitor with a ferroelectric dielectric material having main component Barium-titanate (BaTiO 3 ), said capacitor satisfying the impedance ratio of the first impedance (Z 1 ) which is obtained by measuring current for alternate voltage of 5 volts, to the second impedance (Z 2 ) which is obtained by measuring current for alternate voltage of 500 volt/mm, being less than 1/10 (Z 2 /Z 1 is less than 1/10), thus, the size of the lighting apparatus is small, and the power loss in the same is reduced.
Inventors
- 👤 Hiromi Adachi
- 👤 Shoichi Iwaya
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 19:45
CPC Classifications
H; H01; H01C; H01C7/00; H01C7/10; H01C7/105; H01C7/108; H01C7/115; H01G; H01G7/00; H01G7/06; H05; H05B; H05B41/00; H05B41/14; H05B41/16; H05B41/20; H05B41/23; H05B41/232
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
155 words
A lighting apparatus for a discharge lamp comprising a discharge lamp and a current limiting device connected in series with said discharge lamp, wherein said current limiting device is composed of a ferroelectric polycrystalline ceramic having an impedance ratio Z 1 /Z 2 of a fractional value of 1/10 or less where the impedance Z 1 is calculated from the current value measured at an alternating field of 5 V/mm and the impedance Z 2 is calculated from the current value measured at an alternating field of 500 V/mm or less, said ferroelectric ceramic comprising mainly barium titanate (BaTiO 3 ) in which a part of Ba in the BaTiO 3 is replaced with Sr or Pb and a part of Ti in the BaTiO 3 is replaced with Zr or Sn and a mineralizer consisting of 0.005 to 0.3% by weight of Cr, 0.005 to 0.3% by weight of Mn, or a combination thereof.
Claim 2
Dependent Claim
155 words
A lighting apparatus for a discharge lamp comprising a discharge lamp and a current limiting device connected in series with said discharge lamp, wherein said current limiting device is composed of a ferroelectric polycrystalline ceramic having an impedance ratio Z 1 /Z 2 of a fractional value of 1/10 or less where the impedance Z 1 is calculated from the current value measured at an alternating field of 5 V/mm and the impedance Z 2 is calculated from the current value measured at an alternating field of 500 V/mm or less, said ferroelectric ceramic comprising mainly barium titanate (BaTiO 3 ) in which a part of Ba in the BaTiO 3 is replaced with Sr or Pb and a part of Ti in the BaTiO 3 is replaced with Zr or Sn and a mineralizer consisting of 0.005 to 0.3% by weight of Cr, 0.005 to 0.3% by weight of Mn, or a combination thereof.
Claim 3
Dependent Claim
23 words
A lighting apparatus for a discharge lamp as claimed in claim 1 further comprising a resistor or an inductance connected in series therewith.
Claim 4
Dependent Claim
45 words
A lighting apparatus for a discharge lamp as claimed in claim 1 or 2 wherein said ferroelectric polycrystalline ceramic has a laminated structure comprising a plurality of ceramic layers and internal electrode layers between said ceramic layers, said internal electrode layers being connected together alternately.
Claim 5
Dependent Claim
32 words
A lighting apparatus for a dicharge lamp as claimed in claim 1 or 2 wherein said polycrystalline ceramic contains impurities derived from the starting material which total 0.5% or less by weight.
References Cited (Backward Citations)
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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) | 1988-05-13 | 1988-11-12 | 1989-05-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-05-13 | 1992-11-12 | 1993-05-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-05-13 | 1996-11-12 | 1997-05-14 | $7700.00 | Window Closed / Lapsed |