IP Library Granted Patent US 7,504,778
Granted Patent B2
US 7,504,778 · App. 11/639,230 · Granted Mar 17, 2009

External electrode fluorescent lamp and backlight unit of liquid crystal display device

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Quick Facts
Patent No.
US 7,504,778
App. No.
11/639,230
Granted
Mar 17, 2009
Kind
B2
Abstract

An external electrode fluorescent lamp includes a ferroelectric glass tube filled with discharge gas, and a ferroelectric film on an internal surface of the ferroelectric glass tube.

Claims (30)

1. An external electrode fluorescent lamp, comprising:

a ferroelectric glass tube filled with discharge gas;

a ferroelectric film on an internal surface of the ferroelectric glass tube; and

external electrodes on an external surface of the ferroelectric glass tube overlapping the ferroelectric films,

wherein the external electrode is made from Tin (Sn) of 60˜70% by weight, Bismuth (Bi) of 22˜28% by weight, Zinc (Zn) of 3˜6% by weight, Indium (In) of 1˜2% by weight, Antimony (Sb) of 0.2˜0.7% by weight and Aluminum (Al) Of 0.05˜0.15% by weight.

2. The external electrode fluorescent lamp according to claim 1 , wherein the ferroelectric glass tube has a dielectric constant of about 10˜20.

3. The external electrode fluorescent lamp according to claim 1 , are respectively positioned at ends of the ferroelectric glass tube.

4. The external electrode fluorescent lamp according to claim 1 , wherein the ferroelectric glass tube includes at least one of Li2O, Na2O, K2O and BaO.

5. The external electrode fluorescent lamp according to claim 1 , wherein the ferroelectric film has a dielectric constant of about 4˜20.

6. The external electrode fluorescent lamp according to claim 5 , wherein the ferroelectric film includes at least one of Barium Titanate (BaTiO3), Lithium Niobate (LiNbO3), Gadolinium Molybdate (Gd2(MoO4)3), Antimony Sulphoiodide (SbSI), Sodium Nitrite (NaNO2), Potassium Dihydrogen Phosphate (KH2PO4), Triglycine Sulfate ((NH2CH2COOH)3H2SO4) and Rochelle salt (NaKC4H4O6.4H2O.

7. The external electrode fluorescent lamp according to claim 1 , wherein the discharge gas is argon (Ar).

8. The external electrode fluorescent lamp according to claim 1 , wherein pressure of the discharge gas is about 5˜45 torr.

9. The external electrode fluorescent lamp according to claim 1 , further comprising:

metal tubes on the external surface of the ferroelectric glass tube at ends of the ferroelectric glass tube.

10. The external electrode fluorescent lamp according to claim 9 , wherein the metal tubes are made of phosphor bronze.

11. A backlight unit of a liquid crystal display device, comprising:

a plurality of external electrode fluorescent lamps that generate light supplied to a liquid crystal display panel;

a diffusion plate that disperses light generated from the external electrode fluorescent lamps; and

optical sheets located between the diffusion plate and the liquid crystal display panel to redirect the dispersed light toward the liquid crystal display panel,

wherein the external electrode fluorescent lamp includes:

a ferroelectric glass tube filled with discharge gas; and

a ferroelectric film on an internal surface of the ferroelectric glass tube; and

external electrodes on an external surface of the ferroelectric glass tube and respectively positioned at ends of the ferroelectric glass tubes,

wherein the external electrode is made from Tin (Sn) of 60˜70% by weight, Bismuth (Bi) of 22˜28% by weight, Zinc (Zn) 3˜6% of by weight, Indium (In) of 1˜2% by weight, Antimony (Sb) of 0.2˜0.7% by weight and Aluminum (Al) of 0.05˜0.15% by weight.

12. The backlight unit according to claim 11 , wherein the ferroelectric glass tube has a dielectric constant of about 10˜20.

13. The backlight unit according to claim 11 , wherein the ferroelectric glass tube is made of one of Li2O, Na2O, K2O and BaO.

14. The backlight unit according to claim 11 , wherein the ferroelectric film has a dielectric constant of about 4˜20.

15. The backlight unit according to claim 11 , wherein the discharge gas in the ferroelectric glass tube has an internal pressure of about 5˜45 torr.

16. The backlight unit according to claim 11 , further comprising:

metal tubes at ends of the ferroelectric glass tube.

Assignments (4)
CHANGE OF NAME Recorded Oct 27, 2008
From: LG.PHILIPS LCD CO., LTD.
To: LG DISPLAY CO., LTD.
Reel/Frame 021772/0701 →
CORRECTING SPELLING OF INVENTOR AS CITED ABOVE - REEL/FRAME 018715/0687 Recorded Mar 8, 2007
From: KIM, JAE BUM
To: LG.PHILIPS LCD CO., LTD.
Reel/Frame 019017/0122 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Dec 15, 2006
From: KIM, JAE BUM
To: LG.PHILIPS LCD CO., LTD.
Reel/Frame 018715/0687 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Dec 15, 2006
From: KIM, JAE BAE
To: LG.PHILIPS LCD CO., LTD.
Reel/Frame 019130/0070 →