JP2012064497A - Fluorescent lamp - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fluorescent lamp which is capable of suppressing a reduction in luminous flux.SOLUTION: A fluorescent lamp 100 comprises: a glass tube 1 in which mercury emitting ultraviolet rays by colliding with electrons is hermetically sealed; a phosphor 7 which is formed inside the glass tube 1 and emits visible light by being irradiated with ultraviolet rays; and a contact prevention film 8 which prevents contact between the mercury hermetically sealed in the glass tube 1 and the phosphor 7. Therefore, a chemical reaction between the phosphor 7 and the mercury is suppressed to suppress a reduction in the luminous flux of the fluorescent lamp 100.

Description

  The present invention relates to a fluorescent lamp.

  Mercury is sealed inside the glass tube of the fluorescent lamp. This mercury emits ultraviolet rays by colliding with electrons emitted from one end of the glass tube. A fluorescent material is applied to the inner surface of the glass tube, and the fluorescent lamp emits visible light when it is irradiated with ultraviolet rays. Patent Document 1 discloses a fluorescent lamp that can obtain a stable luminance over a long period of time by improving the binding force between a glass tube and a phosphor.

JP 2009-206045 A

In the fluorescent lamp, the luminous flux decreases with time. The reason is that the phosphor deteriorates by chemical reaction with mercury. In particular, green fluorescent lamps use Zn ₂ SiO ₄ : Mn (Mn is an activator) that is highly reactive with mercury as a phosphor, and have a longer operating life than fluorescent lamps of other colors. It tends to be shorter.

  The present invention has been made in view of such problems, and an object of the present invention is to provide a fluorescent lamp capable of suppressing a decrease in luminous flux.

In order to achieve the above object, the fluorescent lamp of the present invention comprises:
A glass tube hermetically sealed with mercury that emits ultraviolet rays by colliding with electrons,
A phosphor that is formed on the inner surface of the glass tube and emits visible light when exposed to ultraviolet rays;
A contact prevention film formed by laminating the phosphor and preventing contact between the mercury and the phosphor;
It is characterized by having.

  By suppressing the chemical reaction between the phosphor and mercury, it is possible to provide a fluorescent lamp capable of suppressing a decrease in luminous flux.

It is a principal part longitudinal cross-sectional view of the fluorescent lamp which concerns on embodiment. It is a cross-sectional view of the fluorescent lamp according to the embodiment.

  A fluorescent lamp 100 according to this embodiment is a hot cathode fluorescent lamp having a straight glass tube 1 as shown in FIG. The inner surface of the glass tube 1 is coated with a phosphor 7 for converting ultraviolet light into visible light, and a contact prevention film 8 is further coated on the phosphor 7. The contact prevention film 8 suppresses a chemical reaction between the phosphor 7 and mercury by preventing contact between the mercury hermetically sealed in the glass tube 1 and the phosphor 7. Hereinafter, the fluorescent lamp 100 will be described with reference to the drawings.

  As shown in FIG. 1, the fluorescent lamp 100 includes a glass tube 1 in which a discharge gas 6 is sealed, a base 2, a base pin 3, an electrode 4, a filament 5, a phosphor 7, and a contact prevention film 8. And a protective film 9.

  The glass tube 1 is a straight tube type glass tube, and a base 2 is provided at both ends thereof. The cross section of the glass tube 1 is circular as shown in FIG. 2, and the tube diameter is, for example, not less than 10 mm and not more than 38 mm.

  The base 2 is a bottomed cylindrical body made of, for example, aluminum. A pair of base pins 3 protrudes from the base 2. An electrode 4 is electrically connected to the base pin 3.

  The electrode 4 is disposed at both ends of the fluorescent lamp 100, and a filament 5 is provided at the tip thereof. When a voltage is applied to the cap pin 3, a current flows through the filament 5.

  The filament 5 is a coiled metal wire, and its surface is coated with an electron-emitting material composed of barium oxide (BaO), strontium oxide (SrO), calcium oxide (CaO), or the like. When the filament 5 is heated by energization, it emits electrons from the electron-emitting material on the surface.

  The discharge gas 6 is composed of a rare gas and mercury vapor, and is hermetically sealed in the glass tube 1. The rare gas is for adjusting the pressure inside the glass tube 1 and is composed of a mixed gas such as argon or neon. The mercury vapor is for obtaining ultraviolet rays for exciting the phosphor 7, and emits ultraviolet rays by colliding with electrons emitted from the filament 5.

The phosphor 7 is for converting ultraviolet rays emitted from mercury into visible light. In the case of a phosphor emitting green light, Zn ₂ SiO ₄ : Mn (Mn is an activator) is included. Phosphor 7 is coated on the inner surface of the glass tube 1, the amount applied is, for example, a per unit area ^{3mg / cm 2 ~7mg / cm 2} .

The contact prevention film 8 is made of magnesium oxide (MgO) or the like. Contact prevention film 8 is applied to laminate the phosphor 7, the amounts applied are, for example, per unit area ^{0.1mg / cm 2 ~1.9mg / cm 2} . The contact prevention film 8 suppresses the chemical reaction between mercury and the phosphor 7 by preventing direct contact between the phosphor 7 and the glass tube 1 with mercury inside.

The protective film 9 is made of magnesium oxide (MgO) or the like. Protective film 9 is applied between the phosphor 7 and the glass tube 1, the amount applied is, for example, a per unit area ^{0.1mg / cm 2 ~1.9mg / cm 2} . The protective film 9 prevents sodium contained in the glass tube 1 from dissolving with time and reacting with the phosphor 7. The protective film 9 prevents the phosphor 7 from being deteriorated and suppresses the decrease in the luminous flux of the fluorescent lamp 100. Further, the protective film 9 reflects a part of the ultraviolet light that has passed through the phosphor 7 and returns it to the phosphor 7, thereby improving the luminous flux value of the fluorescent lamp 100.

  The configuration of the fluorescent lamp 100 has been described above. Next, the operation of the fluorescent lamp 100 will be described.

  When a voltage is applied to the electrode 4, a discharge occurs between the electrodes 4. Mercury hermetically sealed in the glass tube 1 emits ultraviolet rays by discharge. The emitted ultraviolet light passes through the contact prevention film 8 and is irradiated on the phosphor 7. The phosphor 7 is excited by ultraviolet rays and emits visible light. Some ultraviolet rays pass through the phosphor 7 and reach the protective film 9. The ultraviolet rays are reflected by the protective film 9 and returned to the phosphor 7 again. The phosphor 7 converts the ultraviolet rays irradiated from both the contact prevention film 8 side and the protective film 9 side into visible light and emits it to the outside.

  According to the present embodiment, the contact preventing film 8 laminated on the phosphor 7 can prevent direct contact between the phosphor 7 and mercury hermetically sealed in the glass tube 1. As a result, deterioration of the phosphor 7 can be prevented, and a decrease in the luminous flux of the fluorescent lamp 100 can be suppressed.

  Moreover, mercury consumption is reduced by suppressing the chemical reaction between the phosphor 7 and mercury. As a result, the lighting life of the fluorescent lamp 100 can be extended.

  Further, since the chemical reaction between the phosphor 7 and mercury is suppressed, lamp discoloration (coloring) that occurs when mercury is adsorbed on the phosphor 7 can be prevented.

  According to the present embodiment, the protective film 9 formed between the glass tube 1 and the phosphor 7 prevents sodium contained in the glass tube 1 from melting and reacting with the phosphor 7 over time. it can. As a result, the phosphor 7 can be prevented from deteriorating and the decrease in the luminous flux can be suppressed.

  Further, the protective film 9 reflects the ultraviolet light that has passed through the phosphor 7 and returns it to the phosphor 7, so that the phosphor 7 can be irradiated with no ultraviolet light. As a result, the luminous efficiency of the fluorescent lamp 100 can be increased.

  The phosphor 7 may be a red light-emitting phosphor, a green light-emitting phosphor, or a blue light-emitting phosphor. Further, it may be a three-wavelength phosphor containing at least one phosphor of each color.

Examples of the red light emitting phosphor include Y ₂ O ₃ : Eu, Y ₂ O ₃ S: Eu, SrS: Eu, CaS: Eu, CaAlSiN ₃ : Eu, or La ₂ O ₂ S: Eu. It may be. Moreover, what mixed these may be contained.

Examples of the green light emitting phosphor include LaPO ₄ : Ce, Tb, BaMgAl ₁₀ O ₁₇ : Eu, Mn, (MgCaSrBa) Si ₂ O ₂ N ₂ : Eu, Ba ₂ SiO ₄ : Eu, CeMgAl ₁ 1O _19. : Tb, LaPO ₄ : Tb, (Ce, Gd) MgB ₅ O ₁₀ : Tb, Zn ₂ SiO ₄ : Mn, or the like may be contained. Moreover, what mixed these may be contained.

Further, blue fluorescent light emitters include, for example, BaMg ₂ Al ₁₆ O ₂₇ : Eu, ZnS: Ag, (Ba, Sr) MgAl ₁₀ O ₁₇ : Eu, Mn, or (Ba, Sr, Ca, Mg) _{10. (PO 4)} 6 _C l2: it may contain Eu, and the like. Moreover, what mixed these may be contained.

For the contact prevention film 8 and the protective film 9, yttrium oxide (Y ₂ O ₃ ), lanthanum oxide (La ₂ O ₃ ), aluminum oxide (Al ₂ O ₃ ), magnesium oxide (MgO), silicon dioxide (SiO ₂ ) , Cerium dioxide (CeO ₂ ), titanium monoxide (TiO), titanium dioxide (TiO ₂ ), zinc oxide (ZnO), bismuth oxide (Bi ₂ O ₃ ), copper oxide (CuO), gadolinium oxide (Gd ₂ O ₃₎ ), Chromium oxide (Cr ₂ O ₃ ), nickel oxide (NiO), samarium oxide (Sm ₂ O ₃ ), niobium pentoxide (Nb ₂ O ₅ ), zirconium dioxide (ZrO ₂ ), etc. Also good. Moreover, what mixed these may be contained.

In addition, the contact prevention film 8 and the protective film 9 include calcium fluoride (CaF ₂ ), magnesium fluoride (MgF ₂ ), strontium fluoride (SrF ₂ ), barium fluoride (BaF ₂ ), and cerium fluoride (CeF). ₃ ), neodymium fluoride (NdF ₃ ), or perovskite (Na ₂ AlF ₆ ) may be contained. Moreover, what mixed these may be contained. Further, the contact preventing film 8 and the protective film 9 may include a mixture of oxide and fluoride.

  The thickness of the contact prevention film 8 is 0.05 μm or more and 3 μm or less, preferably 0.1 μm or more and 2 μm or less. This is because when the thickness of the contact prevention film 8 is larger than 3 μm, the contact prevention film 8 may absorb the ultraviolet rays and reduce the ultraviolet rays reaching the phosphor 7. Further, when the thickness of the contact prevention film 8 is thinner than 0.05 μm, it is difficult to prevent mercury from contacting the phosphor 7.

  The thickness of the protective film 9 is 0.05 μm or more and 3 μm or less, preferably 0.1 μm or more and 2 μm or less. This is because when the thickness of the protective film 9 is thicker than 3 μm, the luminous flux may decrease. Further, when the thickness of the protective film 9 is thinner than 0.05 μm, it is difficult to prevent the phosphor 7 and the glass tube 1 from contacting each other.

  The shape of the glass tube 1 is not limited to a straight tube shape. The glass tube 1 may have a U-shape, a W-shape, a ring shape, a spiral shape, or other bent shapes such as a glass tube used in a bulb-type fluorescent lamp.

  The rare gas contained in the discharge gas 6 is not limited to a mixed gas with argon or neon. As the rare gas, krypton may be used alone or mixed with argon and neon. The discharge gas 6 may be mixed with other inert gas.

  The fluorescent lamp 100 may be a cold cathode fluorescent lamp used as a backlight of a liquid crystal monitor in addition to a hot cathode fluorescent lamp. At this time, the tube diameter of the glass tube 1 may be, for example, not less than 1.8 mm and not more than 5.0 mm.

  A part or all of the above-described embodiment can be described as in the following supplementary notes, but is not limited thereto.

(Appendix 1) A glass tube hermetically sealed with mercury that emits ultraviolet rays by colliding with electrons,
A phosphor that is formed inside the glass tube and emits visible light when exposed to ultraviolet rays;
A contact prevention film formed by laminating the phosphor and preventing contact between the mercury and the phosphor;
A fluorescent lamp characterized by comprising:

(Additional remark 2) The protective film which is formed between the said fluorescent substance and the inner wall of the said glass tube, and prevents the said fluorescent substance and the said glass tube from contacting,
The fluorescent lamp according to appendix 1, further comprising:

(Additional remark 3) The said contact prevention film and / or the said protective film contain the oxide and / or fluoride,
The fluorescent lamp according to appendix 1 or 2, characterized in that.

(Supplementary Note 4) The oxide includes yttrium oxide, lanthanum oxide, aluminum oxide, magnesium oxide, silicon dioxide, cerium dioxide, titanium monoxide, titanium dioxide, zinc oxide, bismuth oxide, copper oxide, gadolinium oxide, chromium oxide, Contains one or more of nickel oxide, samarium oxide, niobium pentoxide, zirconium dioxide,
The fluorescent lamp according to Supplementary Note 3, wherein

(Supplementary Note 5) The fluoride includes one or more of calcium fluoride, magnesium fluoride, strontium fluoride, barium fluoride, cerium fluoride, neodymium fluoride, and elite.
The fluorescent lamp according to Supplementary Note 3, wherein

(Appendix 6) The phosphor is a green-emitting phosphor.
The fluorescent lamp according to any one of appendices 1 to 5, characterized in that:

(Appendix 7) The phosphor includes Zn ₂ SiO ₄ .
The fluorescent lamp according to appendix 6, which is characterized in that.

(Appendix 8) The contact prevention film is formed to have a weight of 0.1 mg to 1.9 mg per 1 cm ^{2 of the} inner wall of the glass tube.
The fluorescent lamp according to any one of appendices 1 to 7, characterized in that:

DESCRIPTION OF SYMBOLS 1 Glass tube 2 Base 3 Base pin 4 Electrode 5 Filament 6 Discharge gas 7 Phosphor 8 Contact prevention film 9 Protective film 100 Fluorescent lamp

Claims (8)

A glass tube hermetically sealed with mercury that emits ultraviolet rays by colliding with electrons,
A phosphor that is formed inside the glass tube and emits visible light when exposed to ultraviolet rays;
A contact prevention film formed by laminating the phosphor and preventing contact between the mercury and the phosphor;
A fluorescent lamp characterized by comprising: A protective film formed between the phosphor and the inner wall of the glass tube to prevent contact between the phosphor and the glass tube;
The fluorescent lamp according to claim 1, further comprising: The contact prevention film and / or the protective film contains an oxide and / or fluoride,
The fluorescent lamp according to claim 1, wherein the fluorescent lamp is a fluorescent lamp. Examples of the oxide include yttrium oxide, lanthanum oxide, aluminum oxide, magnesium oxide, silicon dioxide, cerium dioxide, titanium monoxide, titanium dioxide, zinc oxide, bismuth oxide, copper oxide, gadolinium oxide, chromium oxide, nickel oxide, and oxide. Contains one or more of samarium, niobium pentoxide, zirconium dioxide,
The fluorescent lamp according to claim 3. The fluoride includes at least one of calcium fluoride, magnesium fluoride, strontium fluoride, barium fluoride, cerium fluoride, neodymium fluoride, and perovskite.
The fluorescent lamp according to claim 3. The phosphor is a green-emitting phosphor.
The fluorescent lamp according to any one of claims 1 to 5, wherein: The fluorescent lamp according to claim 6, wherein the phosphor includes Zn ₂ SiO ₄ . The contact prevention film is formed to have a weight of 0.1 mg to 1.9 mg per 1 cm ^{2 of the} inner wall of the glass tube.
The fluorescent lamp according to claim 1, wherein the fluorescent lamp is a fluorescent lamp.

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