Fluorescent lamp with UV-blocking layer and protective sleeve

• US 8,053,962 B2
• Filed: 05/04/2009
• Issued: 11/08/2011
• Est. Priority Date: 05/04/2009
• Status: Expired due to Fees

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Jansma, Jon B., Kostka, James Michael
• Primary Examiner(s): Patel; Nimeshkumar
• Assistant Examiner(s): DIAZ, JOSE
• Application Number:
  US12/435,215
• Publication Number:
  US 20100277056A1
• Time in Patent Office: 918 Days
• Field of Search: 313/110, 313/112
• US Class Current: 313/112
• CPC Class Codes: H01J 61/34 Double-wall vessels or containers
• CPC Class Codes: H01J 61/35 provided with coatings on the walls thereof; Selection of materials for the coatings using coloured coatings H01J61/40; using luminescent coatings H01J61/42
• CPC Class Codes: H01J 61/72 having a main light-emitting filling of easily vaporisable metal vapour, e.g. mercury

Abstract

A fluorescent lamp having a protective polymeric sleeve to provide impact resistance and contain fragments if the lamp shatters. A UV-blocking layer is coated on the outside of the glass envelope of the lamp or on the inside of the sleeve to help protect the polymeric sleeve from UV degradation. The UV-blocking layer includes a UV-blocking component of Al₂O₃ or ZnO or SiO₂ or TiO₂ or mixtures thereof.

Claims

1. A sleeve-protected fluorescent lamp comprising a mercury vapor discharge fluorescent lamp surrounded by a sleeve, the fluorescent lamp comprising a light-transmissive glass envelope having an inner surface, a pair of electrode structures mounted inside said envelope, a first base sealing a first end of the lamp, a second base sealing a second end of the lamp, a discharge-sustaining fill comprising inert gas sealed inside said envelope, and a phosphor layer inside said envelope and adjacent the inner surface of the envelope, the sleeve comprising a layer of polymeric material, the sleeve-protected lamp further comprising a UV-blocking layer between the polymeric material layer and the glass envelope, the UV-blocking layer comprising a UV-blocking component of Al₂O₃ or ZnO or SiO₂ or TiO₂ or mixtures thereof, the inside diameter of the sleeve being at least 0.2 mm greater than the outside diameter of the lamp so that there is a gap between the lamp and the sleeve, wherein the UV-blocking layer comprises a mixture of Al₂O₃, ZnO and SiO₂.

2. The lamp of claim 1, wherein the inside diameter of the sleeve is at least 1 mm greater than the outside diameter of the lamp.

3. The lamp of claim 1, wherein the inside diameter of the sleeve is at least 1.5 mm greater than the outside diameter of the lamp.

4. The lamp of claim 1, wherein the coating weight of the UV-blocking component is 0.2-8 mg/cm².

5. The lamp of claim 1, wherein the coating weight of the UV-blocking component is 0.7-4 mg/cm².

6. The lamp of claim 1, wherein the polymeric material layer is UV-stabilized polycarbonate.

7. The lamp of claim 1, wherein the polymeric material layer is 100-1000 microns thick.

8. The lamp of claim 1, wherein the UV-blocking layer permits not more than 20% transmission at 390 nm after 50 hours of operation.

9. The lamp of claim 1, wherein the UV-blocking layer is at least 75 weight percent UV-blocking component.

10. The lamp of claim 1, wherein the coating weight of the UV-blocking component is 1-3 mg/cm².

11. The lamp of claim 1, wherein the inside diameter of the sleeve is at least 2 mm greater than the outside diameter of the lamp.

12. The lamp of claim 1, wherein the UV-blocking layer comprises binder, said binder being selected from the group consisting of polysilanes, polyacrylics, polyurethanes, copolymers of these, and mixtures thereof.

13. The lamp of claim 1, wherein the UV-blocking layer comprises binder, said binder being an inorganic binder.

14. A sleeve-protected fluorescent lamp comprising a mercury vapor discharge fluorescent lamp surrounded by a sleeve, the fluorescent lamp comprising a light-transmissive glass envelope having an inner surface, a pair of electrode structures mounted inside said envelope, a first base sealing a first end of the lamp, a second base sealing a second end of the lamp, a discharge-sustaining fill comprising inert gas sealed inside said envelope, and a phosphor layer inside said envelope and adjacent the inner surface of the envelope, the sleeve comprising a layer of polymeric material, the sleeve-protected lamp further comprising a UV-blocking layer between the polymeric material layer and the glass envelope, the UV-blocking layer comprising a UV-blocking component of Al₂O₃ or ZnO or SiO₂ or TiO₂ or mixtures thereof, the inside diameter of the sleeve being at least 0.2 mm greater than the outside diameter of the lamp so that there is a gap between the lamp and the sleeve, wherein the UV-blocking layer is a coating on the outside surface of the glass envelope, wherein the UV-blocking layer comprises a mixture of Al₂O₃, ZnO and SiO₂.

15. The lamp of claim 14, wherein the inside diameter of the sleeve is at least 1 mm greater than the outside diameter of the lamp.

16. The lamp of claim 14, wherein the coating weight of the UV-blocking component is 0.2-8 mg/cm².

17. The lamp of claim 14, wherein the coating weight of the UV-blocking component is 0.7-4 mg/cm².

18. The lamp of claim 14, wherein the UV-blocking layer permits not more than 20% transmission at 390 nm after 50 hours of operation.