Lumen maintenance in fluorescent lamps

• US 10,236,174 B1
• Filed: 12/28/2017
• Issued: 03/19/2019
• Est. Priority Date: 12/28/2017
• Status: Active Grant

• Current Assignee: Lucidity Lights, Inc.
• Original Assignee: Lucidity Lights, Inc.
• Inventors: Miller, Harris R., Nanchung, Tenzin Wangjor, Larson, Bruce C., Straney, Donald C., Mossoba, Joseph T., Russo, Harold, Agger, Jacob, Ghiu, Camil, Goscha, John R.
• Primary Examiner(s): Tan, Vibol
• Application Number:
  US15/856,422
• Time in Patent Office: 446 Days
• 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 61/44 Devices characterised by the luminescent material
• CPC Class Codes: H01J 61/46 Devices characterised by the binder or other non-luminescent constituent of the luminescent material, e.g. for obtaining desired pouring or drying properties
• CPC Class Codes: H01J 61/523 Heating or cooling particular parts of the lamp
• CPC Class Codes: H01J 65/048 the field being produced by using an excitation coil
• CPC Class Codes: H05B 41/2806 with semiconductor devices and specially adapted for lamps without electrodes in the vessel, e.g. surface discharge lamps, electrodeless discharge lamps
• CPC Class Codes: H05B 41/38 Controlling the intensity of light

Abstract

A fluorescent lamp, including a vitreous portion of the fluorescent lamp comprising a vitreous envelope filled with a working gas mixture, the vitreous envelope having an inner surface facing the working gas mixture side of the vitreous portion; a first coating deposited on the inner surface, the first coating comprising a first metal oxide; a second coating deposited on top of the first coating, the second coating comprising a phosphor; and a third coating deposited on top of the second coating, the third coating comprising a second metal oxide.

Claims

1. A fluorescent lamp, comprising:

a vitreous portion of the fluorescent lamp comprising a vitreous envelope filled with a working gas mixture, the vitreous envelope having an inner surface facing a working gas mixture side of the vitreous portion;

a first coating deposited on the inner surface, the first coating comprising a first metal oxide;

a second coating deposited on top of the first coating, the second coating comprising a phosphor;

a third coating deposited on top of the second coating, the third coating comprising a second metal oxide; and

wherein the first coating protects the inner surface from reaction with chemicals from the working gas mixture.

2. The lamp of claim 1, wherein the first and third coatings of metal oxide envelop the second coating of phosphor and decrease the reaction of the working gas mixture with the phosphor and the inner surface of the vitreous envelope.

3. The lamp of claim 1, wherein at least one of the first coating and third coating is aluminum oxide or silicon dioxide.

4. The lamp of claim 1, wherein the first coating protects the inner surface from deposition of chemicals from the working gas mixture onto the inner surface.

5. A fluorescent lamp, comprising:

a vitreous portion of the fluorescent lamp comprising a vitreous envelope filled with a working gas mixture, the vitreous envelope having an inner surface facing a working gas mixture side of the vitreous portion;

a first coating deposited on the inner surface, the first coating comprising a first metal oxide;

a second coating deposited on top of the first coating, the second coating comprising a phosphor;

a third coating deposited on top of the second coating, the third coating comprising a second metal oxide; and

wherein the third coating protects the phosphor from chemical reaction of the working gas mixture or plasma discharge with the phosphor.

6. A fluorescent lamp, comprising:

a vitreous portion of the fluorescent lamp comprising a vitreous envelope filled with a working gas mixture, the vitreous envelope having an inner surface facing a working gas mixture side of the vitreous portion;

a first coating deposited on the inner surface, the first coating comprising a first metal oxide;

a second coating deposited on top of the first coating, the second coating comprising a phosphor;

a third coating deposited on top of the second coating, the third coating comprising a second metal oxide; and

wherein the coatings are baked or fired at elevated temperature to improve adhesion of the coatings and prevent them from being removed during subsequent coating steps.

15. The lamp of claim 6, wherein the fluorescent lamp further comprises an inverter circuit operating at a first frequency, a timing circuit operating at a second frequency equal to or less than half the first frequency, and an enable circuit activated by the timing circuit that enables and disables the inverter circuit.

16. The lamp of claim 6, wherein the vitreous portion of the fluorescent lamp comprises a remote glass sealing configuration.

17. The lamp of claim 6, wherein the fluorescent lamp has an outward appearance of a G25 incandescent bulb.

18. The lamp of claim 6, wherein the fluorescent lamp further comprises ballast electronics with layered EMI shielding and head spreader.

19. The lamp of claim 6, wherein the fluorescent lamp utilizes UV light sources to excite the phosphor coating through at least one of non-mercury plasma discharge, UV light emitting diodes (LEDs), cathode ray tube emission, field-emission cathodoluminescence UV, and visible light generators.

20. The lamp of claim 6, wherein the fluorescent lamp utilizes a first and second burner to provide temperature selection.

7. A fluorescent lamp, comprising:

a vitreous portion of the fluorescent lamp comprising a vitreous envelope filled with a working gas mixture, the vitreous envelope having an inner surface facing a working gas mixture side of the vitreous portion;

a first coating deposited on the inner surface, the first coating comprising a first metal oxide;

a second coating deposited on top of the first coating, the second coating comprising a phosphor;

a third coating deposited on top of the second coating, the third coating comprising a second metal oxide;

wherein at least one of the coatings of metal oxide and phosphor are applied with a binder material to achieve more uniform coatings; and

wherein the binder material is cross-linked to facilitate application of multiple layers without damaging or degrading previously applied layers.

8. The lamp of claim 7, wherein the binder material is cross-linked by chemical treatment, heat treatment, or exposure to light (including ultraviolet light).

9. A fluorescent lamp, comprising:

a vitreous portion of the fluorescent lamp comprising a vitreous envelope filled with a working gas mixture, the vitreous envelope having an inner surface facing a working gas mixture side of the vitreous portion;

a first coating deposited on the inner surface, the first coating comprising a first metal oxide;

a second coating deposited on top of the first coating, the second coating comprising a phosphor;

a third coating deposited on top of the second coating, the third coating comprising a second metal oxide; and

wherein at least one of the first and third coatings are comprised of nanoparticles.

10. The lamp of claim 9, wherein the nanoparticles are less than 1 micrometer in size.

11. The lamp of claim 9, wherein at least one of the first and third coatings are applied in the form of pre-dispersed solutions in order to achieve more complete and uniform coatings.

12. The lamp of claim 11, wherein at least the first and third coatings are eliminated by combining the metal oxide and phosphor particles into one coating.

13. A fluorescent lamp, comprising:

a vitreous portion of the fluorescent lamp comprising a vitreous envelope filled with a working gas mixture, the vitreous envelope having an inner surface facing a working gas mixture side of the vitreous portion;

a first coating deposited on the inner surface, the first coating comprising a first metal oxide;

a second coating deposited on top of the first coating, the second coating comprising a phosphor;

a third coating deposited on top of the second coating, the third coating comprising a second metal oxide; and

wherein the third coating protects the second coating of phosphor from being damaged by ion bombardment from plasma discharge of the working gas mixture.

14. A fluorescent lamp, comprising:

a vitreous portion of the fluorescent lamp comprising a vitreous envelope filled with a working gas mixture, the vitreous envelope having an inner surface facing a working gas mixture side of the vitreous portion;

a first coating deposited on the inner surface, the first coating comprising a first metal oxide;

a second coating deposited on top of the first coating, the second coating comprising a phosphor;

a third coating deposited on top of the second coating, the third coating comprising a second metal oxide; and

wherein the third coating protects the second coating of phosphor from being damaged from ultraviolet radiation from plasma discharge of the working gas mixture.

21. A fluorescent lamp, comprising:

a vitreous portion of the fluorescent lamp comprising a vitreous envelope filled with a working gas mixture, the vitreous envelope having an inner surface facing a working gas mixture side of the vitreous portion;

a first coating deposited on the inner surface, the first coating comprising a first metal oxide;

a second coating deposited on top of the first coating, the second coating comprising a phosphor;

a third coating deposited on top of the second coating, the third coating comprising a second metal oxide; and

wherein the first coating protects the second coating of phosphor from reaction with chemicals from vitreous material of the inner surface.