JPH06181051A - Electrodeless discharge lamp - Google Patents

Abstract

PURPOSE:To make the evaporation amount of a light emitting substance in a bulb be a large amount and lower the color temperature. CONSTITUTION:An induction coil 2 is coiled on a circumference of a bulb 1 in which a neodymium halide as a light emitting substance is sealed. High frequency electric power is applied to the induction coil 2 from a high frequency generating apparatus 3. The light emitting substance is excited and emits light due to the reaction of the high frequency electromagnetic field generated in the surrounding of the induction coil 2 to the light emitting substance. A heat insulation film 4 is formed on the part of the bulb 1 except the part near the induction coil 2. As a result, due to the heat keeping function of the heat insulation film 4, the gas pressure of the light emitting substance in the bulb 1 becomes high and color temperature is lowered.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrodeless electrode which does not have an electrode inside the bulb and which causes a high-frequency electromagnetic field to act on the luminescent substance enclosed in the bulb from the outside to cause the luminescent substance to emit light. It relates to a discharge lamp.

[0002]

2. Description of the Related Art Conventionally, by applying a high-frequency electromagnetic field to a light-emitting substance enclosed in a bulb, so-called high-frequency discharge is generated in the bulb to excite and ionize the light-emitting substance to emit light. An electrodeless discharge lamp has been proposed. This type of electrodeless discharge lamp has features such as small size, high efficiency, and long life as disclosed in Japanese Patent Laid-Open No. 62-43058, and therefore researches and developments at various places. Has been done. In addition, Japanese Patent Laid-Open No. 3-1
It is known that the use of a light emitting substance containing no mercury as described in Japanese Patent No. 52852 will increase the color purity.

By the way, when neodymium halide is used as a light-emitting substance containing no mercury, the luminous efficiency is high because the emission spectrum is close to the luminosity curve, and a large number of line spectra are observed over the entire visible light region. It is known that an electrodeless discharge lamp having a high color rendering property can be provided due to the fact that it radiates.

[0004]

However, when neodymium halide is used as the light-emitting substance, the spectrum intensity near 400 nm becomes strong when the temperature of the bulb is low, and when it is used for general lighting such as household lighting. There is a problem that the color temperature is too high. That is, it is desirable to set the color temperature to about 5000K in general lighting, but if neodymium halide is used as the light emitting material, the color temperature becomes too high. Here, if the high-frequency power input to generate the high-frequency electromagnetic field is increased, the temperature inside the bulb rises, the spectral intensity near 500 nm becomes stronger, and the color temperature lowers, but large power should be input. Will be needed.

An object of the present invention is to solve the above-mentioned problems, and when neodymium halide is used as a luminescent material, an electrodeless discharge lamp capable of lowering the color temperature without requiring a large amount of electric power. Is to provide.

[0006]

In order to achieve the above object, in the invention of claim 1, a translucent bulb in which neodymium halide is enclosed as a luminescent substance and a high-frequency electromagnetic field is applied from outside the bulb. In an electrodeless discharge lamp equipped with an induction coil that excites and emits a luminescent substance, a translucent heat insulating film that suppresses heat radiation from the bulb is applied to a portion of the outer peripheral surface of the bulb wall excluding the vicinity of the coil. Is there.

In the invention of claim 2, the heat insulating film is made of gold, silver,
It is made of a material selected from platinum.

[0008]

According to the above-mentioned structure, since the heat insulating film is applied to the outer peripheral surface of the pipe wall of the valve, the temperature of the coldest spot can be increased as compared with the case where the heat insulating film is not provided. Even if the input high frequency power is low power, the vapor pressure of the luminescent material can be increased by increasing the vaporization amount of the luminescent material to the same extent as in the case of inputting high power. As a result, by using neodymium halide as the light emitting material, it is possible to obtain a light source having high luminous efficiency and excellent color rendering properties, and it is possible to achieve a desired color temperature for general lighting with low power consumption.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG. 1, a bulb 1 is formed into an airtight spherical shape by using a material such as quartz glass having a light-transmitting property. Gas is enclosed. On the outer circumference of the valve 1, the valve 1
A conductive wire forming the induction coil 2 is wound around one axis of the induction coil 2, and both ends of the induction coil 2 are connected to the high frequency generator 3. The high frequency generator 3 includes a high frequency generator 3a that outputs a high frequency, an amplifier 3b that power-amplifies the output of the high frequency generator 3a, and a matching circuit unit 3 that is inserted between the amplifier 3b and the induction coil 2 to match impedance.
and c. As the light emitting substance, a mixture of neodymium halide and alkali metal halide is used.

A heat insulating film 4 is applied to the outer peripheral surface of the tube wall of the valve 1 except for the vicinity of the induction coil 2. As the heat retaining film 4, a metal thin film of platinum, gold, silver or the like can be used. Light can be transmitted through this type of metal thin film. When the high frequency power from the high frequency generator 3 is input to the induction coil 2, the high frequency electromagnetic field generated around the induction coil 2 acts on the light emitting substance to excite the light emitting substance to emit light. At this time, the existence of the heat insulating film 4 suppresses the heat radiation from the valve 1, and as a result, the temperature of the coldest spot is kept at the heat insulating film 4.
Will be higher than the case without. That is, the vaporization amount of the luminescent material increases and the vapor pressure increases.

For example, when the outer diameter of the valve 1 is 27 mm, NdI ₃ is 15 mg, CsI is 5 mg, and xenon gas is 100 Torr, the efficiency is 40 lm / W at the input of 200 W and the color without the heat insulating film 4. While the temperature was 10500K, when a platinum film was used as the heat insulating film 4, the efficiency was 38lm / for 200W input.
W, color temperature reached 5500K. That is, the color temperature could be significantly reduced with almost no reduction in efficiency. FIG. 2 shows the spectrum distribution when the heat insulating film 4 is provided, and FIG. 3 shows the spectrum distribution when the heat insulating film 4 is not provided. As is clear from a comparison of FIGS. 2 and 3, it can be seen that when the heat insulating film 4 made of platinum is provided, the output light amount on the short wavelength side is decreased, so that the color temperature is decreased.

The number of turns of the induction coil 2 is not particularly limited and may be one or more turns. Further, instead of the xenon gas, another type of gas or a mixed gas of two or more types of gas may be used. Further, the above numerical values and light emitting substances are merely examples and are not intended to be limited, and the shape of the bulb 1 is not limited to spherical.

[0013]

As described above, the present invention includes a translucent bulb in which neodymium halide is encapsulated as a luminescent substance, and an induction coil for exciting a luminescent substance by causing a high-frequency electromagnetic field to act from outside the bulb. In the equipped electrodeless discharge lamp, a translucent heat insulating film that suppresses heat radiation from the bulb is applied to the outer peripheral surface of the bulb wall excluding the vicinity of the coil. It is possible to raise the temperature of the coldest spot and increase the vaporization amount of the luminescent material to the same extent as when high power is input, even if the input high frequency power is low power. The pressure can be increased. As a result, by using neodymium halide as the light-emitting substance, it is possible to obtain a light source having high luminous efficiency and excellent color rendering properties.
It has the advantage that the desired color temperature for general lighting can be achieved with low power.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment.

FIG. 2 is a diagram showing a spectrum of output light according to an example.

FIG. 3 is a diagram showing a spectrum of output light when a heat insulating film is not provided.

[Explanation of symbols]

 1 valve 2 induction coil 3 high frequency generator 4 heat insulating film

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[Procedure amendment]

[Submission date] May 10, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Claim 1

[Correction method] Change

[Correction content]

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0004

[Correction method] Change

[Correction content]

[0004]

However, when neodymium halide is used as the light-emitting substance, the spectrum intensity near 400 nm becomes strong when the temperature of the bulb is low, and when it is used for general lighting such as household lighting. There is a problem that the color temperature is too high. That is, it is desirable to set the color temperature to about 5000K in general lighting, but if neodymium halide is used as the light emitting material, the color temperature becomes too high. Here, if the high-frequency power input to generate the high-frequency electromagnetic field is increased, the temperature inside the bulb rises, the spectral intensity near 500 nm becomes stronger, and the color temperature lowers, but large power should be input. Will be needed.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0006

[Correction method] Change

[Correction content]

[0006]

In order to achieve the above object, in the invention of claim 1, a translucent bulb in which neodymium halide is enclosed as a luminescent substance and a high-frequency electromagnetic field is applied from outside the bulb. In an electrodeless discharge lamp equipped with an induction coil that excites a luminescent substance to emit light, a portion of the outer peripheral surface of the bulb wall excluding the vicinity of the induction coil
The coercive Yutakamaku is're deposited.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0010

[Correction method] Change

[Correction content]

A heat insulating film 4 is applied to the outer peripheral surface of the tube wall of the valve 1 except for the vicinity of the induction coil 2. The insulation film 4, it is possible to use platinum, gold, gold Shokumaku such as silver. When the high frequency power from the high frequency generator 3 is input to the induction coil 2, the high frequency electromagnetic field generated around the induction coil 2 acts on the light emitting substance to excite the light emitting substance to emit light. At this time, the presence of the heat insulating film 4 suppresses the heat radiation from the valve 1, and as a result, the temperature of the coldest spot increases as compared with the case where the heat insulating film 4 is not provided. That is, the vaporization amount of the luminescent material increases and the vapor pressure increases.

[Procedure Amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0013

[Correction method] Change

[Correction content]

[0013]

As described above, the present invention includes a translucent bulb in which neodymium halide is encapsulated as a luminescent substance, and an induction coil which excites the luminescent substance by causing a high-frequency electromagnetic field to act from outside the bulb. in an electrodeless discharge lamp having, since the depositing coercive Yutakamaku the site except the vicinity of the induction coil in the tube wall outer surface of the bulb, the temperature of the coldest point portion as compared to the case without the heat insulating layer It is possible to raise the vapor pressure of the luminescent material by increasing the amount of vaporization of the luminescent material to the same extent as when high power is input even if the high frequency power to be input is low power. As a result, by using neodymium halide as the light emitting material, it is possible to obtain a light source having high luminous efficiency and excellent color rendering properties, and it is possible to achieve a desired color temperature for general lighting with low power. .

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shin Ogawa, 1048 Kadoma, Kadoma, Osaka Prefecture Matsushita Electric Works Co., Ltd. (72) Shingo Tosaka, 1048, Kadoma, Kadoma City, Osaka Matsushita Electric Works, Ltd. (72) Inventor Miki Otani 1048, Kadoma, Kadoma-shi, Osaka Prefecture Matsushita Electric Works Co., Ltd. (72) Inventor Motohiro Hitomi, 1048, Kadoma, Kadoma-shi, Osaka Prefecture Matsushita Electric Works Co., Ltd.

Claims (2)

[Claims] 1. An electrodeless discharge lamp comprising a translucent bulb in which neodymium halide is encapsulated as a luminescent substance, and an induction coil which excites the luminescent substance to emit light by applying a high-frequency electromagnetic field from outside the bulb, An electrodeless discharge lamp characterized in that a transparent heat insulating film for suppressing heat radiation from the bulb is applied to a portion of the outer peripheral surface of the bulb wall except for the vicinity of the coil. 2. The electrodeless discharge lamp according to claim 1, wherein the heat insulating film is made of a material selected from gold, silver and platinum.