JPS61126757A - High voltage discharge lamp - Google Patents

Abstract

PURPOSE:To control resonant sound waves concerned to the bulb axis direction resonant sound waves and maintain a stable lighting of a lamp, by furnishing a soft composite such as quartz wool at the inner surface of the ends in the axis direction of a luminous bulb. CONSTITUTION:A soft composite 10 such as quartz wool is furnished at the inner surface of the ends in the axis direction of a luminous bulb 1. In general, a resonant sound wave is a wave of condensation and rarefaction, and groups up when the phases of the reflection at the bulb end and the sound wave at the oscillation source are uniform. Therefore, the soft composite at the bulb end will absorb the sound wave, controlling the growing up of a resonant wave. As a result,a combined mode including an axis direction specific waves cannot grow up, resulting in a wide stable lighting frequency area of the arc.

Description

【発明の詳細な説明】 （技術分野） 本発明は、ＨＩＤランプの如き高圧放電ランプに関する
。TECHNICAL FIELD The present invention relates to high pressure discharge lamps such as HID lamps.

（背景技術） 第１図は従来の高圧放電ランプの一例を示し、石英ガラ
ス等で形成された発光管１の両端には電ａ２ａ、２ｂが
対向して配設され、該両電極２ａ、２ｂは封止部３ａ、
３ｂに封入されたモリブデン箔等の金属箔４ａ、４ｂに
接続されている。金属箔４ａ、４ｂは発光管１の支持も
兼ねる支持導線５ａ、５ｂに接続されており、発光管１
は固定治具６ａ、６ｂを介して支持導線５ａ、５ｂに固
定されている。支持導線５ａ、５ｂは口金７を介して外
部回路に接続される。また、発光管１内には希ガス及び
発光物質が適量封入されており、発光管１を被う外管８
内にはガスが封入され、外管８の内面には螢光体９が塗
布されている。(Background Art) FIG. 1 shows an example of a conventional high-pressure discharge lamp, in which electrodes a2a and 2b are disposed facing each other at both ends of an arc tube 1 made of quartz glass or the like. is the sealing part 3a,
It is connected to metal foils 4a and 4b, such as molybdenum foil, sealed in 3b. The metal foils 4a and 4b are connected to support conductors 5a and 5b which also serve as support for the arc tube 1.
are fixed to the support conductors 5a, 5b via fixing jigs 6a, 6b. Support conductors 5a and 5b are connected to an external circuit via a base 7. In addition, an appropriate amount of rare gas and a luminescent substance are sealed inside the arc tube 1, and an outer tube 8 that covers the arc tube 1 is provided.
Gas is sealed inside, and the inner surface of the outer tube 8 is coated with a fluorescent substance 9.

かかる従来の高圧放電ランプを高周波電源で点灯すると
、発光効率が向上すると共に、点灯回路の電子化による
安定器の小型・軽量化、低損失化が図れるという利点が
ある。しかし、一方では発光管内の音速と発光管形伏で
決定される特定の周波数で音響的共鳴現象が発生し、ア
ーク柱の湾曲、揺らぎ、立ち消え、発光管の破壊等が発
生するといった欠点がある。When such a conventional high-pressure discharge lamp is lit with a high-frequency power source, there are advantages in that the luminous efficiency is improved, and the ballast can be made smaller and lighter, and its loss can be reduced by electronicizing the lighting circuit. However, on the other hand, it has the disadvantage that an acoustic resonance phenomenon occurs at a specific frequency determined by the speed of sound inside the arc tube and the shape of the arc tube, causing arc column curvature, fluctuation, extinction, and destruction of the arc tube. .

安定に点灯するためには、高圧放電ランプが安定に点灯
する周波数域を選択して点灯すれば良いが、安定に点灯
する周波数域はランプの種類によって異なり、また、同
一種類のランプに対しても、ランプ個体間にばらつきが
有るため、特定の周波数を設定するのは困難であった。In order to light up stably, it is sufficient to select a frequency range in which the high-pressure discharge lamp lights stably, but the frequency range in which it lights stably varies depending on the type of lamp, and it also However, it was difficult to set a specific frequency due to variations between individual lamps.

また、１００ｋＨｚ以上の周波数での高周波点灯、直流
点灯、矩形波点灯等により音響的共鳴現象を回避する方
法が提案されているが、かかる点灯方法においては、回
路構成の複雑化や放射電波雑音の発生等の問題がある。In addition, methods have been proposed to avoid acoustic resonance phenomena by using high-frequency lighting at a frequency of 100 kHz or higher, direct current lighting, square wave lighting, etc. However, such lighting methods tend to complicate the circuit configuration and increase radiated radio noise. There are problems such as occurrence.

（発明の目的） 本発明は、上記欠点を除去するために成されたもので、
その目的とするところは、高周波点灯時に、音響的共鳴
現象による不安定なアークが発光管に発生しない高圧放
電ランプを提供するにある（発明の開示） まず、音響的共鳴現象について説明する。音響的共鳴現
象は、発光管形状と封入物質で決まる固有撮動数と、入
力電力の時間変化による発光管内の圧力変動とが一致し
た時に定在波が立つために生じる共鳴現象である。(Object of the invention) The present invention was made in order to eliminate the above-mentioned drawbacks.
The object is to provide a high-pressure discharge lamp in which an unstable arc is not generated in the arc tube due to the acoustic resonance phenomenon during high-frequency lighting (Disclosure of the Invention) First, the acoustic resonance phenomenon will be explained. Acoustic resonance is a resonance phenomenon that occurs when a standing wave is created when the intrinsic imaging number determined by the arc tube shape and the enclosed material matches the pressure fluctuation within the arc tube due to time changes in input power.

発光管を円筒形状と仮定し、円筒座標系（ｒ。Assuming that the arc tube has a cylindrical shape, the cylindrical coordinate system (r.

θ、ｚ）を考える。なお、ｒは径方向、θは周方向、２
は軸方向の座標を表す。かかる場合、上記各方向に対す
る共鳴現象の基本周波数Ｆｒ、Ｆθ、Ｆｚは、次のよう
になる。θ, z). Note that r is the radial direction, θ is the circumferential direction, and 2
represents the coordinate in the axial direction. In such a case, the fundamental frequencies Fr, Fθ, and Fz of the resonance phenomenon in each of the above directions are as follows.

ｒ方向共鳴：　Ｆ　ｒ　＝３．８３Ｃ／　（２πＲ）θ
方向共鳴：Ｆθ−１．８４Ｃ／　（２πＲ）２方向共鳴
：　Ｆ　ｚ　＝Ｃ／　（２Ｌ）ただし Ｌは発光管長。r-direction resonance: F r =3.83C/ (2πR)θ
Directional resonance: Fθ-1.84C/ (2πR) Two-directional resonance: F z =C/ (2L) where L is the arc tube length.

Ｒは発光管の半径。R is the radius of the arc tube.

Ｃは発光管内の音速であり、管内封入物と管内温度で決
まる。C is the sound velocity inside the arc tube, which is determined by the contents inside the tube and the temperature inside the tube.

Ｃ−、／ｙＰＴ／Ｍ Ｔ一定圧比熱／定積比熱 Ｐ−気体定数 Ｔ−発光管内温度 Ｍ−封入気体の平均質量 そして、この基本周波数の整数倍の周波数で共鳴現象が
発生する。音響的共鳴現象が発生すると、共鳴現象によ
って生じた力が、アーク柱自体が有する安定放電を持続
させようとする力に打ち勝って、アーク柱が変形する。C-, /yPT/MT constant pressure specific heat/constant volume specific heat P-gas constant T-temperature inside the arc tube M-average mass of the enclosed gas.The resonance phenomenon occurs at a frequency that is an integral multiple of this fundamental frequency. When an acoustic resonance phenomenon occurs, the force generated by the resonance phenomenon overcomes the force of the arc column itself to maintain stable discharge, causing the arc column to deform.

一般に、高周波点灯をするときには、可聴周波数領域を
避けて点灯するため、点灯周波数は数十Ｋ　ｔｌｚにな
る。この周波数域で発生する音響的共鳴現象では、径方
向、周方向及びこれらに軸方向が混成された共鳴モード
が存在する。しかも、混成モードが発生する共鳴周波数
は多数存在する。Generally, when high-frequency lighting is performed, the lighting frequency is several tens of K tlz because the lighting is performed while avoiding the audible frequency range. In the acoustic resonance phenomenon that occurs in this frequency range, there are resonance modes in the radial direction, circumferential direction, and a combination of these resonance modes in the axial direction. Furthermore, there are many resonance frequencies at which hybrid modes occur.

そこで、本発明は発光管の管軸方向端部における音響的
反射率を低下することにより、軸方向定在波を含む混成
モードを抑制し、音響的共鳴現象を回避したものである
。　　′ 実施例 第２図は本発明に係る発光管の一実施例を示すもので、
発光管１の管軸方向端部内面に石英ウール等の柔構造体
１０を設けたものである。一般に、共鳴音波は疎密波で
あり、管端での反射と加振源による音波との位相が揃っ
て成長するものである。従って、管端を柔構造にしてお
けば、管端で音波が吸収されるため、共鳴音波は成長し
きれなくなる。そのため、軸方向定在波を含む混成モー
ドが成長しきれなくなり、アークの安定な点灯周波数領
域が広くなる。Therefore, the present invention suppresses the hybrid mode including the axial standing wave and avoids the acoustic resonance phenomenon by reducing the acoustic reflectance at the ends of the arc tube in the tube axis direction. 'Embodiment Figure 2 shows an embodiment of the arc tube according to the present invention.
A flexible structure 10 made of quartz wool or the like is provided on the inner surface of the end of the arc tube 1 in the tube axis direction. Generally, a resonant sound wave is a compressional wave, and grows when the reflection at the tube end and the sound wave from the excitation source are in phase. Therefore, if the pipe end is made to have a flexible structure, the sound wave will be absorbed at the pipe end, and the resonant sound wave will not be able to grow completely. Therefore, the hybrid mode including the axial standing wave cannot grow completely, and the stable arc lighting frequency range becomes wider.

（発明の効果） 本発明は上記のように、発光管の管軸方向端部内面に石
英ウール等の柔構造体を設けたことにより、管端での反
射波を減衰させたり、反射波の位相を不揃いにすること
により、軸方向共鳴音波に関係する共鳴音波を抑制する
ことが可能となる。(Effects of the Invention) As described above, the present invention provides a flexible structure such as quartz wool on the inner surface of the end of the arc tube in the tube axis direction, thereby attenuating the reflected waves at the tube end. By making the phases uneven, it becomes possible to suppress resonance sound waves related to axial resonance sound waves.

従って、本発明に係る高圧放電ランプを高周波電力で点
灯しても、音響的共鳴現象によるアーク柱の湾曲、揺ら
ぎ、立ち消え、発光管の破壊等が防止でき、安定した点
灯を維持することができる効果がある。Therefore, even when the high-pressure discharge lamp according to the present invention is lit with high-frequency power, it is possible to prevent arc column curvature, fluctuation, extinguishing, and destruction of the arc tube due to acoustic resonance phenomena, and stable lighting can be maintained. effective.

【図面の簡単な説明】[Brief explanation of drawings]

第１図は従来の高圧放電ランプの正面図、第２図は本発
明に係る発光管の一実施例を示す一部断面の正面図であ
る。 １・・・発光管、１０・・・柔構造体。FIG. 1 is a front view of a conventional high-pressure discharge lamp, and FIG. 2 is a partially sectional front view showing an embodiment of an arc tube according to the present invention. 1... Arc tube, 10... Flexible structure.

Claims (1)

【特許請求の範囲】[Claims] （１）発光管の管軸方向端部内面に柔構造体を設けたこ
とを特徴とする高圧放電ランプ。(1) A high-pressure discharge lamp characterized in that a flexible structure is provided on the inner surface of the end of the arc tube in the tube axis direction.