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US5089943A Expired / Lapsed US ⏱️ 0.0 years remaining

Illuminating device, having two identical lamps connected in parallel

Assignee: VDO Luftfahrtgerate Werk GmbH
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Filing: 1990-12-12
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Granted: 1992-02-18
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Expires: 2010-12-12
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Abstract

Abstract An illuminating device has two lamps developed as discharge tubes which have a serpentine course and are nested in each other by, in each case, a narrow U-shaped region and a wide U-shaped region. In this way both lamps can be of identical development and permit uniform illumination of a rectangular liquid crystal cell even upon failure of one lamp.

Inventors

  • 👤 Lothar Wolfelschneider

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-28 18:53
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/1333; G02F1/1335; G02F1/1336; G02F1/133602; G02F1/133604; G02F1/133613

Claims Analysis

Total Claims: 4
Claim 1
Independent Claim 120 words
An illuminating device for illuminating a rectangular surface, comprising two identical lamps connected electrically in parallel; and means for positioning the lamps in nested arrangement wherein each lamp is developed as a gas-discharge tube of serpentine shape having at least one narrow U-shaped region and an adjoining wider U-shaped region; each lamp has its U-shaped regions nested within the U-shaped regions of the other lamp providing for engagement of the narrow U-shaped region of one lamp into the wider U-shaped region of the other lamp; and each of said lamps has, in sequential order, a first narrow U-shaped region, a wider U-shaped region and, adjoining same, a second narrow U-shaped region which is shorter than the first narrow U-shaped region.
Claim 2
Dependent Claim 120 words
An illuminating device for illuminating a rectangular surface, comprising two identical lamps connected electrically in parallel; and means for positioning the lamps in nested arrangement wherein each lamp is developed as a gas-discharge tube of serpentine shape having at least one narrow U-shaped region and an adjoining wider U-shaped region; each lamp has its U-shaped regions nested within the U-shaped regions of the other lamp providing for engagement of the narrow U-shaped region of one lamp into the wider U-shaped region of the other lamp; and each of said lamps has, in sequential order, a first narrow U-shaped region, a wider U-shaped region and, adjoining same, a second narrow U-shaped region which is shorter than the first narrow U-shaped region.
Claim 3
Dependent Claim 175 words
A liquid crystal cell assembly comprising: a liquid crystal cell; a lightbox disposed behind the cell for directing light through the cell from a back surface of the cell toward a front surface of the cell; two lamps disposed in the box in a coplanar arrangement for generating the light, each of said lamps having a serpentine shape having U-shaped bends, wherein U-shaped bends of a first of the lamps nest between U-shaped bends of the second of the lamps; wherein each lamp is developed as a gas-discharge tube of serpentine shape having at least one narrow U-shaped region and an adjoining wider U-shaped region; each lamp has its U-shaped regions nested within the U-shaped regions of the other lamp providing for engagement of the narrow U-shaped region of one lamp into the wider U-shaped region of the other lamp; and each of said lamps has, in sequential order, a first narrow U-shaped region, a wider U-shaped region and, adjoining same, a second narrow U-shaped region which is shorter than the first narrow U-shaped region.
Claim 4
Dependent Claim 175 words
A liquid crystal cell assembly comprising: a liquid crystal cell; a lightbox disposed behind the cell for directing light through the cell from a back surface of the cell toward a front surface of the cell; two lamps disposed in the box in a coplanar arrangement for generating the light, each of said lamps having a serpentine shape having U-shaped bends, wherein U-shaped bends of a first of the lamps nest between U-shaped bends of the second of the lamps; wherein each lamp is developed as a gas-discharge tube of serpentine shape having at least one narrow U-shaped region and an adjoining wider U-shaped region; each lamp has its U-shaped regions nested within the U-shaped regions of the other lamp providing for engagement of the narrow U-shaped region of one lamp into the wider U-shaped region of the other lamp; and each of said lamps has, in sequential order, a first narrow U-shaped region, a wider U-shaped region and, adjoining same, a second narrow U-shaped region which is shorter than the first narrow U-shaped region.

References Cited (Backward Citations)

US2728845A Cited
US4945350A Cited
EP0274269A1 Cited
US4950053A Cited
US4748546A Cited
GB2207496A Cited
WO1989005037A1 Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1995-02-17 1995-08-19 1996-02-18 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1999-02-17 1999-08-19 2000-02-18 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2003-02-17 2003-08-19 2004-02-18 $7700.00 Window Closed / Lapsed

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