JP3480725B2 - Electrodeless discharge lamp and electrodeless discharge lamp device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrodeless discharge lamp and an electrodeless discharge lamp device.

[0002]

2. Description of the Related Art An electrodeless discharge lamp is different from a normal discharge lamp in that it has no electrode inside the arc tube and excites mercury vapor by a magnetic field and high frequency energy induced from the outside of the glass arc tube. 1995 Illuminating Engineering Society Vol. 79 7
On page 44, Matsushita Electric Works, Ltd. reports on technological trends in electrodeless discharge lamps. Since the structure of the arc tube of a general electrodeless fluorescent lamp does not require a coil emitter inside, it is simple as shown in an example in FIG. 8, and an external coil is installed on the outer circumference of the arc tube. Then, it is turned on by applying high frequency power in a frequency band of several hundreds of hertz to several megahertz. Therefore, since the electrodeless discharge lamp has no life in which the internal coil of the arc tube is not lit due to wear and break, the life of the arc tube is semi-permanent.

Also, unlike a normal discharge lamp having electrodes inside the arc tube, the influence of the length of the discharge path between the coils is small, and further space saving and energy saving are expected. Further, the shape of the arc tube is not limited to the conventional tube shape, but a spherical shape, a cylindrical shape, or other various arc tube shapes and lighting system shapes that are unprecedented are possible depending on the input form of high-frequency power.

However, since the excited light emission of mercury is used, the distribution of mercury, which contributes to light emission, is apt to change due to the influence of changes in external temperature and radiation and convection of external and internal heat during lighting. This significantly changes the characteristics of the lamp. Therefore, it has been devised to use an amalgam to collect an excessive amount of mercury in the amalgam to keep the mercury vapor pressure in the arc tube constant.

[0005]

However, the mercury emission of a discharge lamp using amalgam is affected to a considerable extent by the ambient temperature. When the amalgam temperature at the time of lighting is 80 to 120 ° C., 90% output is obtained, which is a sufficient characteristic, but especially in the low temperature range where the amalgam is in a solid state, the luminous flux output due to the ambient temperature fluctuates greatly with the power fluctuation. There was a problem. Since electrodeless discharge lamps have electrodes on the outside, they are usually more susceptible to ambient temperature than discharge lamps that use amalgam.
In particular, when used in places with low ambient temperatures, such as in cold regions, the mercury vapor pressure is small, so the input power is also small.
The temperature of the lamp surface will drop and eventually it will not be possible to continue lighting.

Therefore, the present invention provides an electrodeless discharge lamp and an electrodeless discharge lamp device which can improve the power change due to the ambient temperature in the low temperature range of the electrodeless discharge lamp and can obtain a stable output even under severe conditions.

[0007]

In order to solve the above-mentioned problems, an electrodeless discharge lamp according to the present invention is provided with a light emitting part, a neck connected to the light emitting part, a neck, and an amalgam enclosed therein. An arc tube in which mercury and a rare gas are enclosed in a glass bulb consisting of a stem having a narrowed tube, and a cap provided at the end of the light emitting section so as to cover the sealed portion between the neck and the stem. Having a high-frequency current supplied from a high-frequency power source to the induction coil installed outside the arc tube,
An electrodeless discharge lamp that excites and emits light in the arc tube, wherein a heat retaining member is provided so as to cover a portion of the outer surface of the arc tube having the lowest temperature during lighting, and the heat retaining member is configured to emit the light. 1/5 of the entire length of the glass bulb from the base of the tube toward the tip of the arc tube
It is characterized in that it is provided so as to cover a range of 1/3.

The surface of the lamp during lighting is cooled by convection of wind and heat, but the electrodeless discharge lamp of the present invention has a mechanism in which an amalgam is provided away from the coil to collect excess mercury other than vapor. In addition, since it has a function of keeping the glass surface of the arc tube at 60 ° C. or higher, it is possible to keep the mercury vapor pressure of the lamp constant, and high ambient temperature characteristics are expressed even at low temperatures. A stable output can be obtained from low temperature to high temperature. Further, the heat retaining member is 1/5 to 1 of the entire length of the glass bulb (lamp height) from the base of the arc tube toward the tip of the arc tube.
Since it covers / 3, the part including the glass surface having the lowest temperature excluding the base part of the arc tube is covered, so that the surface temperature of the arc tube, which fluctuates under the influence of the external environment, is uniformly maintained. It becomes possible. If the coating ratio is less than 1/5, the heat retaining effect becomes insufficient and stable lamp output cannot be obtained, and if it exceeds 1/3, the light output is reduced by coating.

Further, in the electrodeless discharge lamp of the present invention, the heat insulating member comprises a translucent wind shield, a film-like, fibrous or foamy heat insulating material, a particulate heat insulating material and an infrared reflecting film. It is preferably at least one selected. By properly using these translucent materials, the glass surface of the arc tube can be kept at 60 ° C. or higher.

Further, in the electrodeless discharge lamp of the present invention, in order to maintain a stable lamp output, the translucent wind shield, the film-like, the fibrous or foamy heat insulating material,
It is preferably at least one selected from glass, carbon, felt, nylon resin, Teflon resin, epoxy resin, polyethylene resin, urethane resin, acrylic resin, and vinyl resin.

Further, in the electrodeless discharge lamp of the present invention, in order to maintain a stable lamp output, it is preferable that the particulate heat insulating material is a metal oxide particle having a spectral transmittance of 80% or more.

Further, in the electrodeless discharge lamp of the present invention, in order to maintain a stable lamp output, it is preferable that the infrared reflection film is an aluminum vapor deposition film or a multilayer thin film of metal oxide.

Further, in the electrodeless discharge lamp of the present invention, the amalgam is bismuth, indium, zinc,
At least one selected from tin and lead is preferable. As a result, even at a temperature of 60 ° C. or higher, the amalgam can sufficiently capture excess mercury and maintain a stable lamp output.

Next, the electrodeless discharge lamp device of the present invention comprises:
An arc tube in which mercury and a rare gas are encapsulated in a glass bulb comprising a light emitting part, a neck part connected to the light emitting part, and a stem having a narrow tube sealed with the neck part and having an amalgam enclosed therein; A light emitting portion has a base provided at an end portion of the light emitting portion so as to cover a sealing portion between the neck portion and the stem, and a high frequency current is applied to an induction coil installed outside the light emitting tube by a high frequency power source to emit the light. A device for lighting an electrodeless discharge lamp that excites and emits light in a tube, wherein when the electrodeless discharge lamp is mounted on the lighting device, a part of the outer surface of the arc tube having the lowest temperature during lighting is covered. A heat insulating member is provided, and the heat insulating member covers a range of 1/5 to 1/3 of the entire length of the glass bulb from the base of the arc tube toward the tip direction of the arc tube. You .

[0015]

DETAILED DESCRIPTION OF THE INVENTION An embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows an example of the structure of the electrodeless discharge lamp of the present invention.
Shown in. As shown in FIG. 1, the electrodeless discharge lamp of the present invention is attached to a lighting device 3 and is lit by high frequency. A heat retaining member 7 is attached to the lighting device 3, and by attaching this lamp to the lighting device 3, 1/3 of the lamp is covered with the heat retaining member 7. As shown in FIG. 2, an arc tube 1 in which mercury and a rare gas are enclosed in a glass bulb.
Is bismuth / indium / mercury (72 mass% /
34.5% by mass / 3.5% by mass) amalgam 5
Is enclosed in a thin tube provided on the stem as shown in FIG. In addition, argon gas 50
Pa is filled, and a cerium and terbium activated lanthanum phosphate (LAP) and europium activated yttrium oxide (YOX) mixed phosphor 4 is coated on the inner surface of the glass bulb. Then, as shown in FIG. 1, a coil 2 is installed around the arc tube 1 in a circumferential shape, and a high-frequency current having a frequency of 13.5 MHz is energized by a lighting circuit 3a in the lighting device 3 for lighting. is there.

In the electrodeless discharge lamp of this embodiment,
The lamp with the heat insulation removed has an input power of 50 watts,
It shows a luminous flux output of 4000 lm at an ambient temperature of 40 ° C. When the ambient temperature is changed, the luminous flux of the lamp naturally changes. FIG. 9 shows a case where the ambient temperature is changed from 10 ° C. to 70 ° C. in the conventional lamp having no heat insulating member,
It is a plot of the luminous flux output during a stable state during lighting.
At an ambient temperature of 40 ° C. or higher, almost stable output of nearly 100% is obtained, but at low ambient temperatures of 25 ° C. and 10 ° C., variations in luminous flux occur each time measurement is performed. The average of 10 measurements of the variation of luminous flux shows that the ambient temperature is 40
When the average output at ℃ is 100%, the ambient temperature is 4
The variation was within ± 1% at 0 ° C or higher, but it was 87 ± 10% at an ambient temperature of 25 ° C and 78 ± 1 at an ambient temperature of 10 ° C.
It was 3%. From the results shown in FIG. 9, it was found that when the ambient temperature was 25 ° C. or lower, the output of the lamp changed drastically, and the output change was due to the temperature distribution on the surface of the lamp. Therefore, it was considered that the cause of the output fluctuation was due to the temperature distribution on the lamp surface.

Table 1 shows the results of measuring the temperatures of the coil contact portion 8, the lamp neck portion 9 and the amalgam portion 10 on the surface of the lamp during lighting in a windless state. From the results shown in Table 1, the coil contact portion 8 had a temperature of 100 ° C. or higher, and did not significantly change with respect to the ambient temperature. However, the temperatures of the lamp neck portion 9 and the amalgam portion 10 varied greatly with the ambient temperature.

[0018]

[Table 1] Ambient temperature (° C) Coil contact part (° C) Amalgam part (° C) Lamp neck (° C) 60 170 100 100 85 40 165 80 80 65 65 25 25 160 65 65 50 10 155 50 35

Next, while monitoring the input power of the lamp, the temperature of the surface of the lamp is changed by the wind of the dryer.
Fluctuated to ~ 46W. When the ambient temperature was 25 ° C, the temperature of the lamp neck 9 in the windless state was 50 ° C (see Table 1), but the temperature was 60 ° C to 40 ° C by applying the wind.
Fluctuated up to. Similarly, when the ambient temperature was 40 ° C., the input power was 51 W to 49 W, no matter how much the temperature of the lamp surface was changed by the dryer. Even if the ambient temperature is 60 ° C,
The result was similar.

At an ambient temperature of 40 ° C., the temperature of the amalgam part 10 is 80 ° C., which is a temperature at which the amalgam used is a solid solution. At an ambient temperature of 25 ° C, the amalgam temperature is 65 ° C and the amalgam appears to be solid. From this, at 25 ° C or lower, the temperature of the amalgam is low, so that the function of collecting mercury is small, so that the lamp neck 9 becomes the coldest point, and mercury gathers at that location to regulate mercury vapor. it is conceivable that. Therefore, it was considered that the characteristics were easily affected by the ambient temperature and the characteristic variation occurred.

In the electrodeless discharge lamp of the present invention, the translucent wind shield used as the heat retaining member is made of nylon resin, Teflon resin, epoxy resin, polyethylene resin,
At least one selected from urethane resin, acrylic resin, and vinyl resin is preferable. The shape of the wind shield is not particularly limited, but a cylindrical shape is preferable from the viewpoint of light distribution and aesthetics, and the transmittance is preferably 80% or more.

The film-like, fibrous or foamable heat-insulating material used as the heat-insulating member is formed by molding the above resin into a film, glass wool, carbon fiber, felt fiber, styrene foam, urethane. Examples thereof include foams. When keeping warm with this member,
The thickness is preferably 1.0 to 10 mm.

As the particulate heat insulating material used as the heat insulating member, metal oxide particles having a spectral transmittance of 80% or more are preferably used from the viewpoint of light shielding, and the metal oxide particles are, for example, alumina. , Titania, zinc oxide, silica and the like. Considering convenience, the average particle size of the metal oxide particles is preferably 0.01 to 100 μm. When keeping the temperature with metal oxide particles, for example,
The metal oxide slurry is applied to the surface of the lamp and then dried to form a heat retaining member having a thickness of 0.1 to 300 μm.

The infrared reflection film used as the heat retaining member is preferably an aluminum vapor deposition film or a multilayer thin film of a metal oxide, and the metal oxide is, for example,
Alumina, titania, etc. may be mentioned. In the case of keeping the temperature with these films, a vapor deposition film or a multilayer thin film is formed on the lamp surface by a conventionally known method. The above-mentioned film thickness is not particularly limited, but from the viewpoint of manufacturability, the thickness is 0.
It is preferably from 01 to 100 μm.

The heat retaining member may be a combination of two or more kinds. By combining the heat retaining members, the luminous flux output at a low temperature is increased and the variation is reduced. In particular, a combination of a translucent acrylic windshield and an aluminum vapor deposition film is preferable.
Hereinafter, the present invention will be described in more detail with reference to examples.

[0026]

[Examples] Examples 1 to 6 and Comparative Example 1 A heat insulating structure made of various members was provided on the lamp neck, and an experiment was conducted to examine variations in lamp output at an ambient temperature of 25 ° C. In addition, a conventional lamp that does not have a heat retaining structure is set as Comparative Example 1. The results are shown in Table 2. The average output and the variation are shown as ± in the table, with the output of 40 ° C. having the highest output as 100%. The evaluation was rated as ◯ when the output was 90% or more and the variation in the lamp output was within 1%, and as x in the other cases.

The heat retaining structure used in this embodiment is as follows. The heat insulating structure 1 is an example in which a 5 mm thick acrylic cylindrical wind shield is attached (reference numeral 7 in FIG. 1). The heat retaining structure 2 is an example of a heat retaining structure made of an aluminum vapor deposition film (thickness 50 μm) (reference numeral 7 in FIG. 3). The heat insulating structure 3 is an example in which glass wool is coated with a thickness of 5 mm centering on the coldest part to cover 1/3 of the lamp height excluding the base (FIG. 4).
7). The heat retaining structure 4 is a structure in which the wind shield of Example 2 and the aluminum vapor deposition film of Example 4 are combined to retain heat (not shown).

[0028]

[Table 2] Heat insulation structure Lamp coating Coldest part of lamp Luminous flux output Evaluation type Ratio ¹⁾ Temperature (° C) (%) Example 1 1 1/2 82 89 ± 1 × Example 2 1 1/3 76 98 ± 1 ○ Example 3 1 1/5 65 93 ± 1 △ Example 4 2 1/3 65 91 ± 1 △ Example 5 3 1/3 75 98 ± 1 ○ Example 6 4 1/3 78 98 ± 1 ○ Comparative Example 1 None -50 88 ± 10 × 1) The coverage of the glass surface is shown by the coverage of the lamp height (glass bulb total length) excluding the base.

In Example 1, the temperature of the coldest part, that is, the neck of the lamp is 32 ° C. higher than that of Comparative Example 1 due to the half-height wind shield, and the heat insulating function is excellent, The wind plate obstructed the light output of the lamp, and although the variation disappeared, the output fell below 90%.

In Example 2, the temperature of the coldest portion was increased by 26 ° C. as compared with Comparative Example 1 due to the windshield having the height of 1/3, and the luminous flux output was as good as 98 ± 1%.

In Example 3, the temperature rise of the coldest part was 15 ° C. and the ambient temperature was 25 ° C. due to the windshield having the height of 1/5.
The luminous flux output was 93 ± 1%, which was a good result, but when the ambient temperature was 10 ° C., the temperature of the coldest part was below 60 ° C., and the variation was increased at the luminous flux output of 90 ± 5%.

In Example 4, the temperature of the coldest part was the same as in Comparative Example 1.
15 ° C. above the ambient temperature of 25 ° C., the luminous flux output was 91 ± 1%, which was a good result, but the ambient temperature was 10 ° C.
Since the temperature was below 60 ° C., a variation of 89 ± 6% occurred.

In Example 5, the temperature of the coldest part was the same as in Comparative Example 1.
25 ° C. higher, the luminous flux output was 98 ± 1%, which was a good result, and was 95 ± 1% even at an ambient temperature of 10 ° C., and a high output was obtained without variation.

In Example 6, since the windshield plate shown in Example 2 and the aluminum vapor deposition film shown in Example 4 were combined and kept warm, the heat insulating effect was high and compared to Comparative Example 1. The 28 ° C temperature increased. As a result, ambient temperature 25 ℃
The luminous flux output was 98 ± 1%, and the luminous flux output was 97 ± 1% at an ambient temperature of 10 ° C.

Comparative Example 2 An effect was confirmed in the same manner as in Examples 1 to 6 by using an electrodeless discharge lamp having a shape different from that in Examples 1 to 6 shown in FIG. The electrodeless discharge lamp used in this experiment uses amalgam (Bi: Pb: Sn: Hg), is filled with argon gas, and is coated with the LAP and YOX mixed phosphor on the inner surface of the glass bulb. The results are shown in Table 3. Figure 6
The lamp shown in Fig. 1 has an input power of 15 watts and an ambient temperature of 40.
It showed a luminous flux output of 800 lm at 0 ° C. However, since the heat retaining structure was not provided, the variation in the luminous flux output was 10% at the ambient temperature of 25 ° C.

Example 7 An average particle size of 10 μm was used as a heat insulating material on the inner surface of the lamp.
The experiment was performed in the same manner as in Examples 1 to 6 except that the experiment was performed using a lamp having a heat insulating structure (FIG. 7) in which alumina powder having a spectral transmittance of 93% was applied in a thickness of 30 μm. went. The results are shown in Table 3.

[0037]

[Table 3] Insulation structure Lamp coating Coldest part of the lamp Luminous flux output Evaluation type Ratio ¹⁾ Temperature (° C) (%) Example 7 5 1/3 71 99 ± 1 ○ Comparative Example 2 None-55 85 ± 10 × 1) The coverage of the glass surface is shown as the coverage of the lamp height (glass bulb total length) excluding the base.

In Example 7, it was found that by providing the heat retaining structure, the temperature of the coldest part of the lamp was increased by 16 ° C. as compared with Comparative Example 2, and there was an effect of reducing the variation in output. Even at 10 ° C, the temperature of the coldest part of the lamp is 65
The output was 98 ± 1% at 0 ° C., and it was found that there was almost no change even when the temperature changed. Moreover, the spectral transmittance is 78%.
When an alumina powder having an average particle size of 10 μm was applied to a thickness of 30 μm, there was a heat retention effect, but the luminous flux output was 87
It became ± 1%. It is considered that this is because the luminous flux was lowered due to the low spectral transmittance.

As is clear from the above results, by providing these heat insulating materials at the center of the coldest part of the arc tube, it was possible to widen the range in which a stable luminous flux output can be obtained.
Fig. 9 shows the ambient temperature characteristics of the conventional example.
It can be seen that it can only be used above. However, as shown in FIG. 5, if a heat insulating structure is provided based on the fifth embodiment, a high luminous flux output of 95% or more can be obtained within a variation of 1% at a wide ambient temperature of 10 ° C. to 70 ° C. You can see that

[0040]

As described above, since the electrodeless discharge lamp of the present invention is equipped with the heat retaining member that keeps the glass surface of the arc tube at 60 ° C. or more, stable output can be obtained even at extremely low temperatures and extremely high temperatures. Can be issued. It is extremely convenient and inexpensive to construct such a simple heat retaining structure around the lamp. Therefore, by adopting a structure provided with such a heat retaining member, it is possible to illuminate with an electrodeless discharge lamp regardless of whether it is indoors or outdoors in a cold region or a tropical region which has been unusable until now. Further, the output does not vary depending on the mounting direction of the lamp, and a high output can be stably obtained. Therefore, the effect of the present invention is tremendous, and its industrial value is great.

[Brief description of drawings]

FIG. 1 is a diagram showing an electrodeless discharge lamp (heat retention structure 1) according to an embodiment of the present invention.

FIG. 2 is a sectional view of the electrodeless discharge lamp shown in FIG.

FIG. 3 is a view showing a heat retaining structure 2 of the electrodeless discharge lamp of the present invention.

FIG. 4 is a diagram showing a heat retaining structure 3 of the electrodeless discharge lamp of the present invention.

FIG. 5 is a diagram showing an example of characteristics of the electrodeless discharge lamp of the present invention.

FIG. 6 is a diagram showing an example of an electrodeless discharge lamp that does not include a heat retaining member.

FIG. 7 is a view showing another heat retention structure 5 of the electrodeless discharge lamp of the present invention.

FIG. 8 is a diagram showing an example of a conventional electrodeless discharge lamp.

FIG. 9 is a diagram showing an example of characteristics of a conventional electrodeless discharge lamp.

[Explanation of symbols]

1 arc tube 2 coils 3 lighting device 3a lighting circuit 4 Phosphor 5 amalgam 6 mouthpiece 7 Thermal insulation material 8 Coil contact temperature measurement position 9 Lamp neck temperature measurement position 10 Amalgam temperature measurement position

Continuation of the front page (56) References JP-A-7-94149 (JP, A) JP-A-2001-84803 (JP, A) Actually open flat 7-16398 (JP, U) Actually open 1-143066 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) H01J 65/04 H01J 61/52

Claims (7)

(57) [Claims] 1. Mercury and a noble gas are sealed in a glass bulb comprising a light emitting part, a neck connected to the light emitting part, and a stem having a thin tube sealed with the neck and containing amalgam inside. A light emitting tube and a base provided at an end of the light emitting portion so as to cover a sealing portion between the neck portion and the stem, and a high frequency current is applied to an induction coil installed outside the light emitting tube by a high frequency power source. An electrodeless discharge lamp that energizes to excite the interior of the arc tube to emit light, wherein a heat insulating member is provided so as to cover a portion of the outer surface of the arc tube having the lowest temperature during lighting, and the heat insulating member. Is 1/5 to 1 of the entire length of the glass bulb from the base of the arc tube toward the tip of the arc tube.
An electrodeless discharge lamp, which is provided so as to cover a range of / 3. 2. The heat insulating member is at least one selected from a translucent wind shield, a film-shaped, a fibrous or foamable heat insulating material, a particulate heat insulating material, and an infrared reflective film. Electrodeless discharge lamp described in 3. The light-transmitting wind-shielding plate, film-like, fibrous or foam heat insulating material is glass, carbon, felt, nylon resin, Teflon (registered trademark) resin, epoxy resin, polyethylene resin, urethane. The electrodeless discharge lamp according to claim 2, wherein the electrodeless discharge lamp is at least one selected from resins, acrylic resins, and vinyl resins. 4. The particulate heat insulating material has a spectral transmittance of 80.
The electrodeless discharge lamp according to claim 2, wherein the content of the metal oxide particles is at least%. 5. The electrodeless discharge lamp according to claim 2, wherein the infrared reflective film is a vapor deposited aluminum film or a multilayer thin film of a metal oxide. 6. The electrodeless discharge lamp according to claim 1, wherein the amalgam contains at least one material selected from bismuth, indium, zinc, tin and lead. 7. A mercury bulb and a rare gas are enclosed in a glass bulb comprising a light emitting portion, a neck portion connected to the light emitting portion, and a stem having a thin tube sealed with the neck portion and having amalgam enclosed therein. A light emitting tube and a base provided at an end of the light emitting portion so as to cover a sealing portion between the neck portion and the stem, and a high frequency current is applied to an induction coil installed outside the light emitting tube by a high frequency power source. A device for lighting an electrodeless discharge lamp that energizes to excite the interior of the arc tube to emit light, wherein the temperature of the outer surface of the arc tube during lighting is the lowest when the electrodeless discharge lamp is mounted on the lighting device. A heat retaining member is provided so as to cover a portion, and the heat retaining member extends from the base of the arc tube toward the tip of the arc tube at 1/5 to 1 of the entire length of the glass bulb.
An electrodeless discharge lamp device characterized by covering a range of / 3.