JP3600780B2 - Fluorescent lamp and three-wavelength phosphor - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a fluorescent lamp, and in particular, to reduce a voltage (hereinafter, also referred to as a starting voltage) required to start discharge of a fluorescent lamp (hereinafter, also referred to as starting), and to improve startability. To a fluorescent lamp that can be used.
[0002]
[Prior art]
In a fluorescent lamp, a phosphor efficiently converts ultraviolet light generated into visible light by discharge in a mixed gas of low-pressure mercury vapor and a low-pressure inert gas such as argon, krypton, or neon.
[0003]
At a low temperature, discharge becomes difficult to start due to a decrease in the mercury vapor pressure in the fluorescent lamp, and the voltage required to start the discharge of the fluorescent lamp increases.
[0004]
Here, FIG. 4 shows a cross-sectional view of a lamp bulb of a rapid start type fluorescent lamp in which discharge is easily started.
In FIG. 4, 1 is a glass bulb, 2 is a transparent conductive film, and 3 is a phosphor film. The transparent conductive film 2 is provided between the inner surface of the glass bulb 1 and the phosphor film 3 to assist in starting.
[0005]
However, as described above, the rapid start type fluorescent lamp has a transparent conductive coating on the inner surface of the bulb as a starting aid, but has a greater effect on both ends of the fluorescent lamp at startup than a starter type fluorescent lamp using a glow starter at startup. Such voltages are very low. In particular, the starting voltage at a low temperature is more remarkable.
[0006]
Rapid start type fluorescent lamps include a general type and a power saving type. The power-saving type has an advantage that the power consumption at the time of turning on the fluorescent lamp is reduced due to the composition of the filling gas filled in the lamp bulb, but has the aspect that it is difficult to start discharging. Therefore, the starting voltage of the power saving type is higher than that of the general type.
[0007]
Furthermore, although the cause is not clear, a three-wavelength phosphor (consisting of a red phosphor emitting red light, a green phosphor emitting green light, and a blue phosphor emitting blue light) is used. It is known that the starting voltage of the rapid-start type three-wavelength-band fluorescent lamp used is higher than that of an ordinary rapid-start fluorescent lamp (broadband emission) using a calcium halophosphate phosphor. .
[0008]
Therefore, in the case of a power saving type rapid start type fluorescent lamp using a three-wavelength phosphor, there is a problem that the startability is further deteriorated. In particular, in a low-temperature situation such as winter in northern countries, the starting voltage exceeds the rated input voltage of the fluorescent lamp, and it is extremely difficult to light up, which often poses a practical problem.
[0009]
[Problems to be solved by the invention]
The present invention has been made in order to eliminate the above-mentioned problems of the prior art,
It is an object of the present invention to provide a fluorescent lamp that can improve the startability at a lower temperature than conventional fluorescent lamps.
[0010]
Another object of the present invention is to improve the startability of a rapid start fluorescent lamp (power saving type) using a three-wavelength phosphor at low temperatures.
[0011]
Another object of the present invention is to provide a fluorescent lamp in which a voltage (starting voltage) necessary for starting discharge is lower than a rated input voltage even at a low temperature.
[0012]
[Means for Solving the Problems]
The fluorescent lamp according to the present invention is a fluorescent lamp in which a phosphor film made of a three-wavelength phosphor is formed on an inner surface of a lamp bulb that discharges gas by filling the gas, wherein the mass of the boron element contained in the three-wavelength phosphor is reduced. , And is not less than 0 and not more than 0.006% based on the mass of the three-wavelength phosphor.
[0013]
The fluorescent lamp is a rapid start type fluorescent lamp in which a transparent conductive film made of a transparent and conductive material is formed between the inner surface of the lamp bulb and the phosphor film.
[0014]
The gas sealed in the lamp bulb contains at least one of argon and krypton.
[0015]
The three-wavelength phosphor is a three-wavelength phosphor including a red phosphor that emits red light, a green phosphor that emits green light, and a blue phosphor that emits blue light.
[0016]
The red phosphor includes at least one of europium-activated yttrium oxide and europium-activated yttrium vanadate, the green phosphor includes cerium and terbium-activated lanthanum phosphate, and the blue phosphor includes europium. It contains at least one of activated strontium barium calcium chlorophosphate and europium, manganese activated barium magnesium aluminate and europium activated barium magnesium aluminate.
Further, the mass of the boron element is 0 to 0.003% with respect to the mass of the three-wavelength phosphor.
Further, the mass of the boron element is 0% with respect to the mass of the three-wavelength phosphor.
Further, the three-wavelength phosphor includes a green phosphor that emits green light to which lithium borate is added, and the amount of lithium borate added to the green phosphor is less than the mass of the rare earth oxide when the green phosphor is formed. 0 to 0.08% or less.
Further, the phosphor film contains a binder to which boric acid is added, and the amount of boric acid added as the binder is 0 to 0.034% based on the mass of the three-wavelength phosphor. It is characterized by.
Further, the three-wavelength phosphor according to the present invention includes a green phosphor that emits green light to which lithium borate is added, and the amount of lithium borate added to the green phosphor is less than that of the rare earth element when the green phosphor is formed. It is characterized by being at least 0 and not more than 0.08% with respect to the oxide.
[0017]
【Example】
When examining the cause of the high starting voltage of a rapid-start fluorescent lamp using three-wavelength phosphors that emit red, green, and blue light, the starting voltage of the green phosphor is particularly high among the three-wavelength phosphors. all right. That is, it was found that the red phosphor and the blue phosphor were similar to the calcium halophosphate phosphor (general color), whereas the green phosphor only had a higher starting voltage.
[0018]
In addition, as a result of further investigation, when firing the green phosphor, borate or borate was used for the purpose of accelerating the reaction, assisting the particle size growth of the phosphor, and sufficiently obtaining the brightness of the phosphor. The main cause was found to be boron added in the form of an acid.
[0019]
The reason why boron added in the form of borate or boric acid has affected the increase in the starting voltage has not yet been fully elucidated, but it has been found in the phosphor film of fluorescent lamps. It is believed that boron, present in the form of borate or boric acid, is primarily due to its ability to absorb water.
[0020]
That is, the boron contained in the phosphor emits absorbed water by heating in the baking step of the fluorescent lamp. However, when the fluorescent lamp is subsequently cooled during the sealing and evacuation steps, the boron again absorbs water.
[0021]
For this reason, the fluorescent lamp is completed in a state containing water, which deteriorates the startability of the fluorescent lamp. It is a well-known fact that the constituents of water, hydrogen and oxygen, prevent the discharge of fluorescent lamps.
[0022]
Embodiment 1 FIG.
In the first embodiment, the case where the borate added to the green phosphor is reduced or not added will be described.
[0023]
Lithium borate (Li ₂ B ₄ O ₇ ) is added to a main material of a composite oxide (rare earth oxide) of lanthanum, terbium, and cerium and ammonium phosphate in an amount of 0 to 0.2% by weight based on the composite oxide. Then, the mixture was baked in a reducing atmosphere at 1200 ° C. to obtain cerium and terbium-activated lanthanum phosphate as green phosphors.
[0024]
Here, as a conventional example, lithium borate added to the green phosphor to maintain sufficient brightness of the phosphor is 0.4 to 0.6% based on the composite oxide. In this example, in which the amount of lithium borate added was smaller than that, lithium carbonate was supplemented with lithium carbonate, an additive having the same effect.
[0025]
This green phosphor was mixed with 40 wt% of a red phosphor europium-activated yttrium oxide, 40 wt% of a blue phosphor, and 20 wt% of a manganese-activated barium magnesium aluminate to prepare 100 g of a three-wavelength phosphor. Then, 2 parts by weight of the three-wavelength phosphor were mixed with fine-particle alumina as a binder, deionized water, and polyethylene oxide lacquer to prepare a phosphor paint. The prepared phosphor paint was applied to a glass bulb having a transparent conductive film formed on the inner surface, and then dried. This glass bulb was subjected to predetermined sealing and evacuation processes to produce a rapid start type fluorescent lamp FLR40S • EX-N / M / 36 (power saving type) using a three-wavelength phosphor.
[0026]
FIG. 1 shows the amount of lithium borate added during synthesis of the green phosphor (% by weight based on the rare earth oxide during synthesis of the green phosphor) and the amount of lithium carbonate added instead of lithium borate (green phosphor). Relationship between the weight% of the rare earth oxide at the time of synthesis, the content of boron element contained in the three-wavelength phosphor (% by weight based on the three-wavelength phosphor), and the starting voltage at 5 ° C. (low temperature) of the prepared fluorescent lamp Is shown. FIG. 2 shows the relationship between the boron content in the three-wavelength phosphor and the starting voltage of the fluorescent lamp.
[0027]
As is clear from FIGS. 1 and 2, as the content of the boron element in the three-wavelength phosphor decreases from 0.0148% by weight, the starting voltage of the fluorescent lamp can be reduced. As can be seen from FIG. 2, the starting voltage of the fluorescent lamp is sharply reduced when the boron content of the three-wavelength phosphor is around 0.006% by weight. When the content of boron in the three-wavelength phosphor is 0.006% by weight or less, the content can be reduced to a rated input voltage (200 V) or less, which is a level having no practical problem.
[0028]
When a fluorescent lamp is actually manufactured, there is some variation even if the content of the boron element is determined. Here, as shown in FIGS. 1 and 2, when the content of boron in the three-wavelength phosphor is set to 0.003% by weight or less, the starting voltage of the fluorescent lamp can be reduced to about 191 V. The starting voltage can be reduced by about 10% as compared with the starting voltage of 210 V. Therefore, even if there is some variation in the content of the boron element in the manufacturing process of the fluorescent lamp, the starting voltage can be reduced without being affected by this variation. Therefore, it is more desirable that the content of the boron element in the three-wavelength phosphor be 0.003% by weight or less.
[0029]
In the first embodiment, an example was described in which lithium carbonate was used instead of lithium borate as an additive, but a feature of the present invention is that the amount of boron element contained in the phosphor is reduced or eliminated. Therefore, not limited to lithium carbonate, potassium carbonate and the like may be used.
[0030]
Embodiment 2. FIG.
Boron is used not only as a reaction accelerator in the production of a green phosphor, but also as a binder for fixing the phosphor and the glass bulb in the production of a fluorescent lamp. In this case, boric acid is used. Example 2 describes an example in which boric acid as a binder is not reduced or added.
[0031]
40% by weight of green phosphor cerium and terbium-activated lanthanum phosphate activated by boron in Example 1, 40% by weight of yttrium oxide activated by europium red phosphor, europium blue phosphor, and barium magnesium aluminate activated by manganese 20 By weight, 100 g of a three-wavelength phosphor was obtained. With respect to the mass of the three-wavelength phosphor, boric acid as a binder, deionized water, and polyethylene oxide lacquer were mixed at a ratio of 0 to 0.034% by weight to prepare a phosphor paint. Hereinafter, a rapid start type fluorescent lamp FLR40S • EX-N / M36 (power saving type) using a three-wavelength phosphor was prepared in the same manner as in Example 1.
[0032]
The amount of boric acid added to obtain sufficient binding strength to the glass bulb of the prepared fluorescent lamp is 0.05 to 0.1% by weight based on the mass of the three-wavelength phosphor as a conventional example. . For this reason, in the present Example in which the amount of boric acid added was smaller than this, supplement was made with fine particle alumina as another binder.
[0033]
FIG. 3 shows the amount of boric acid added to the three-wavelength phosphor (% by weight based on the three-wavelength phosphor), the amount of particulate alumina added instead of boric acid (% by weight based on the three-wavelength phosphor), The relationship between the content of the boron element contained in the phosphor of the wavelength (weight% based on the phosphor of the wavelength 3) and the starting voltage at 5 ° C. (at a low temperature) of the produced fluorescent lamp is shown. The relationship between the boron content in the three-wavelength phosphor and the starting voltage of the fluorescent lamp is represented by a graph, which is almost the same as FIG. Therefore, a description will be given with reference to FIG.
[0034]
As is apparent from FIG. 2, the starting voltage of the fluorescent lamp decreases as the content of the boron element in the three-wavelength phosphor decreases. When the content of the boron element in the three-wavelength phosphor is 0.006% by weight or less, the content can be lowered to a rated input voltage (200 V) or less, which is a practically acceptable level. As described in the first embodiment, considering the actual manufacturing process of the fluorescent lamp, the content of the boron element in the three-wavelength phosphor is desirably 0.003% by weight or less.
[0035]
Although an example in which fine-particle alumina was used instead of boric acid as the binder was shown, the feature of the present invention is that the content of the boron element contained in the phosphor is reduced or eliminated. The invention is not limited thereto, and fine particle silicon oxide and fine particle magnesium oxide may be used.
[0036]
In the first and second embodiments, a rapid-start fluorescent lamp (power saving type) using a three-wavelength phosphor has been described. However, a similar effect can be obtained with a general-purpose rapid-start fluorescent lamp.
[0037]
Also, regardless of the method of starting the fluorescent lamp such as a starter type and a rapid start type, the content of the boron element in the phosphor is reduced to 0 regardless of the kind of phosphor used such as a three-wavelength phosphor and a general color calcium halophosphate phosphor. By setting the content to 0.006% by weight or less, the same effect that the starting voltage can be reduced can be obtained.
[0038]
【The invention's effect】
According to the present invention, the content of the boron element in the phosphor can be reduced. For this reason, the starting voltage of the fluorescent lamp can be reduced, and the startability of the fluorescent lamp at low temperatures can be improved.
[0039]
Further, according to the present invention, the starting voltage of the fluorescent lamp can be reduced, and even at a low temperature, the starting voltage can be equal to or lower than the rated input voltage.
[Brief description of the drawings]
FIG. 1 is a graph showing the relationship between the added amount of lithium borate, the added amount of lithium carbonate, and the ratio (wt%) of a boron element contained in a three-wavelength phosphor to the starting voltage of a fluorescent lamp.
FIG. 2 is a diagram showing a relationship between a starting voltage of a fluorescent lamp and a boron content in a three-wavelength phosphor.
FIG. 3 is a diagram showing the relationship between the added amount of boric acid, the added amount of fine-particle alumina, the ratio of the boron element contained in the three-wavelength phosphor, and the starting voltage of the fluorescent lamp.
FIG. 4 is a sectional view of a rapid start type fluorescent lamp bulb.
[Explanation of symbols]
1 Glass bulb, 2 transparent conductive film, 3 phosphor film.

Claims (10)

In a fluorescent lamp in which a phosphor film made of a three-wavelength phosphor is formed on the inner surface of a lamp bulb that discharges by filling gas.
Fluorescent lamp mass of boron element contained in the three-wavelength fluorescent material, characterized in that a 0.006% or less than 0 relative to the mass of the three-wavelength fluorescent material. 2. The fluorescent lamp according to claim 1, wherein the fluorescent lamp is a rapid start type fluorescent lamp in which a transparent conductive film made of a transparent and conductive material is formed between the inner surface of the lamp bulb and the phosphor film. The fluorescent lamp as described. 3. The fluorescent lamp according to claim 2, wherein the gas filled in the lamp bulb contains at least one of argon and krypton. 4. The three-wavelength phosphor according to claim 1, wherein the three-wavelength phosphor includes a red phosphor that emits red light, a green phosphor that emits green light, and a blue phosphor that emits blue light. The fluorescent lamp according to any one of the above. The red phosphor includes at least one of europium-activated yttrium oxide and europium-activated yttrium vanadate,
The green phosphor contains cerium and terbium-activated lanthanum phosphate,
The blue phosphor includes at least one of europium-activated barium calcium strontium chlorophosphate and europium, manganese-activated barium magnesium aluminate, and europium-activated barium magnesium aluminate. The fluorescent lamp according to claim 4. The fluorescent lamp according to claim 1, wherein the mass of the boron element is 0 to 0.003% with respect to the mass of the three-wavelength phosphor. 2. The fluorescent lamp according to claim 1, wherein the mass of the boron element is 0% with respect to the mass of the three-wavelength phosphor. The three-wavelength phosphor includes a green phosphor that emits green light to which lithium borate is added, and the amount of lithium borate added to the green phosphor is based on the mass of the rare earth oxide when the green phosphor is formed. The fluorescent lamp according to claim 1, wherein the fluorescent lamp is not less than 0 and not more than 0.08%. The phosphor film includes a binder to which boric acid is added, and the amount of boric acid added to the binder is 0 to 0.034% based on the mass of the three-wavelength phosphor. The fluorescent lamp according to claim 1 or 8, wherein A green phosphor which emits green light to which lithium borate is added, wherein the amount of lithium borate in the green phosphor is 0 or more and 0.08% or less with respect to the rare earth oxide when the green phosphor is formed; A three-wavelength phosphor, characterized in that:

Images