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US4742277A
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Pulse generating apparatus for xenon lamp and lighting method thereof
Assignee: Toshiba Corp
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Filing: 1987-07-29
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Granted: 1988-05-03
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Expires: 2007-07-29
Abstract
Abstract A pulse generating apparatus includes a base current supply section for generating a constant DC current having a first prescribed current level for turning on a xenon lamp, and a pulse current section for adding a pulse current having a second current level greater than the first current level and a prescribed pulse duration within a prescribed repetition period to the constant DC current. The base current supply section and pulse current section should satisfy the following equations: 1.4≦Imax/Imini≦6 0.2≦t/T≦0.7 T≦1/40 Where Imax is the sum of the first and the second prescribed current levels, Imini is the first prescribed current level, T is the prescribed repetition period, and t is the prescribed pulse duration. When the pulse current added to the DC current is supplied to a xenon lamp, the xenon lamp outputs a strong light during the pulse duration of the pulse current, and a feeble light during the absence of the pulse current.
Inventors
- 👤 Masakazu Shibuya
- 👤 Yasuki Mori
- 👤 Yoshiyuki Tokuda
- 👤 Yoichiro Mitsuyuki
- 👤 Akihiro Kamiya
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 19:00
CPC Classifications
H; H05; H05B; H05B41/00; H05B41/14; H05B41/30
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
118 words
A pulse generating apparatus for a xenon lamp, comprising: base current means for generating a constant DC current having a first prescribed current level for turning on the xenon lamp; and pulse current means for adding a pulse current having a second prescribed current level greater than the first current level and a prescribed pulse duration within a prescribed repetition period to the constant DC current, the base current means and pulse current means satisfying the following equations: 1.4≦Imax/Imini≦6 0.2≦t/T≦0.7 T≦1/40 where Imax is the sum of the first prescribed current level and the second prescribed current level, Imini is the first prescribed current level, T is the prescribed repetition period, and t is the prescribed pulse duration.
Claim 2
Dependent Claim
118 words
A pulse generating apparatus for a xenon lamp, comprising: base current means for generating a constant DC current having a first prescribed current level for turning on the xenon lamp; and pulse current means for adding a pulse current having a second prescribed current level greater than the first current level and a prescribed pulse duration within a prescribed repetition period to the constant DC current, the base current means and pulse current means satisfying the following equations: 1.4≦Imax/Imini≦6 0.2≦t/T≦0.7 T≦1/40 where Imax is the sum of the first prescribed current level and the second prescribed current level, Imini is the first prescribed current level, T is the prescribed repetition period, and t is the prescribed pulse duration.
Claim 3
Dependent Claim
14 words
An apparatus according to claim 1, wherein the base current means includes a ballast.
Claim 4
Dependent Claim
34 words
An apparatus according to claim 1 further including a shutter for interrupting the path of light from the xenon lamp only during the portion of the repetition period other than the prescribed pulse duration.
Claim 5
Dependent Claim
56 words
An apparatus according to claim 3, wherein the pulse current means includes means for generating a plurality of pulse current elements having the second prescribed current level and a prescribed pulse duration during one interrupting period of the shutter, the prescribed pulse duration t being the sum of the pulse duration of each pulse current element.
Claim 6
Independent Claim
97 words
A method for lighting a xenon lamp, including the steps of: generating an operating pulse current, which has a periodic pulse current element and a constant base current element, and which satisfies the equations: 1.4≦Imax/Imini≦6 0.2≦t/T≦0.7 T≦1/40 where Imax is the sum of the current levels of the pulse current element and the base current element, Imini is the current level of the base current element, t is the pulse duration of the pulse current element, and T is the repetition period of the pulse current element; and applying the operating pulse current to the xenon lamp.
Claim 7
Independent Claim
97 words
A method for lighting a xenon lamp, including the steps of: generating an operating pulse current, which has a periodic pulse current element and a constant base current element, and which satisfies the equations: 1.4≦Imax/Imini≦6 0.2≦t/T≦0.7 T≦1/40 where Imax is the sum of the current levels of the pulse current element and the base current element, Imini is the current level of the base current element, t is the pulse duration of the pulse current element, and T is the repetition period of the pulse current element; and applying the operating pulse current to the xenon lamp.
Claim 8
Dependent Claim
30 words
A method according to claim 5 further including step of intermittently interrupting the path of light from the xenon lamp during the period when the pulse current element is absent.
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) | 1991-05-03 | 1991-11-02 | 1992-05-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-05-03 | 1995-11-02 | 1996-05-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-05-03 | 1999-11-02 | 2000-05-03 | $7700.00 | Window Closed / Lapsed |