Patent US4370601A successfully refreshed from Google Patents.
US4370601A
Expired / Lapsed
US
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High pressure discharge lamp apparatus
Assignee: Panasonic Holdings Corp
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Filing: 1981-04-20
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Granted: 1983-01-25
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Expires: 2001-04-20
Abstract
Abstract In a high pressure discharge lamp apparatus comprising a discharge tube and a current limiting device connected in series, an over-current protecting semiconductor switching device such as a triac (TC) is further connected in series to said discharge tube, the triac (TC) being controlled of its firing angle responding to an output of a current detection circuit which detects a change of the lamp current through a change of the lamp voltage, and a pulse generator is further connected in parallel to the discharge tube and gives reignition pulse thereto at least during the zero-current period in each cycle of the lamp current.
Inventors
- 👤 Shigeru Horii
- 👤 Nobuhisa Yoshikawa
- 👤 Kazutaka Koyama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 23:00
CPC Classifications
H; H05; H05B; H05B41/00; H05B41/14; H05B41/16; H05B41/20; H05B41/23; H05B41/231; Y; Y10; Y10S; Y10S315/00; Y10S315/02; Y10S315/07
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
69 words
A high pressure discharge lamp apparatus comprising: a discharge tube, a current limiting device and an over-current protecting device which are connected in series with said discharge tube across a power source, a pulse generator connected in parallel to said discharge tube to supply pulses to said discharge tube, and a lamp current detecting circuit to detect a lamp current and give control signal to said over-current protecting device.
Claim 2
Dependent Claim
69 words
A high pressure discharge lamp apparatus comprising: a discharge tube, a current limiting device and an over-current protecting device which are connected in series with said discharge tube across a power source, a pulse generator connected in parallel to said discharge tube to supply pulses to said discharge tube, and a lamp current detecting circuit to detect a lamp current and give control signal to said over-current protecting device.
Claim 3
Dependent Claim
19 words
A high pressure discharge lamp apparatus of claim 1, wherein said over-current protecting device is a semiconductor switching device.
Claim 4
Dependent Claim
22 words
A high pressure discharge lamp apparatus of claim 1, wherein said lamp current detecting circuit includes a means for detecting lamp voltage.
Claim 5
Dependent Claim
29 words
A high pressure discharge lamp apparatus of claim 2, wherein a zero-current period in each cycle of said semiconductor switching device is controlled by a firing angle controlling circuit.
Claim 6
Dependent Claim
37 words
A high pressure discharge lamp apparatus of claim 4, wherein said pulse generator issues pulses for making a reignition of said discharge tube during at least said zero-current period in each cycle of said semiconductor switching device.
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) | 1986-01-24 | 1986-07-26 | 1987-01-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-01-24 | 1990-07-26 | 1991-01-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-01-24 | 1994-07-26 | 1995-01-25 | $7700.00 | Window Closed / Lapsed |