JPS61124049A - High pressure discharge lamp - Google Patents

Abstract

PURPOSE:To obtain high pressure discharge lamp which does not generate unstable arc from the luminous bulb due to the acoustic resonant phenomenon while it is lighting by generating temperature difference of bulb axis direction of luminous bulb while it is lighting. CONSTITUTION:When acoustic resonant phenomenon is generated at the aluminous bulb while it is lighting, arc column is deformed. The standing wave in the luminous bulb is concentrated to the low temperature side. Therefore, a high sound pressure portion can be concentrated to the low temperature side by preparing temperature distribution in the bulb axis direction of luminous bulb. The external wall of luminous bulb 1 is coated with temperature shielding film by varying distribution of film thickness in the bulb axis direction. Almost the half located at the upper side of internal surface of external bulb 8 of high pressure discharge lamp which lights vertically is coated with temperature shielding film 10. The heater 11 for heating connected in series to the support conductor leads 5a, 5b is wound to the one half of the external circumference of luminous bulb 1. With this structure, the standing wave generating points can be concentrated to the low temperature side of luminous bulb 1 and influence of standing wave to the arc column can be eliminated.

Description

【発明の詳細な説明】 （技術分野） 本発明は、高圧放電灯に関に関する。[Detailed description of the invention] (Technical field) The present invention relates to high pressure discharge lamps.

（背景技術） 第１図は従来の高圧放電灯の一例を示し、石英ガラス等
で形成された発光管１の両端には電極２ａ、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５ａ、５ｂ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 2a and 2b are disposed facing each other at both ends of an arc tube 1 made of quartz glass or the like. are the sealing parts 3a and 3b
The metal foils 4a and 4b, such as molybdenum foils, are sealed in the metal foils 4a and 4b. The metal foils 4a, 4b are connected to support conductors 5a, 5b which also serve as supports for the arc tube 1, and the arc tube 1 is fixed to the support conductors 5a, 5b via fixing jigs 5a, 5b. Support conductors 5a and 5b are connected to an external circuit via a base 7. Further, the arc tube 1 is filled with a suitable amount of a rare gas and a luminescent substance, the outer tube 8 that covers the arc tube 1 is filled with gas, and the inner surface of the outer tube 8 is coated with a phosphor 9. has been done.

かかる従来の高圧放電灯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状で決定
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 using 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 in the arc tube and the shape of the arc tube, causing curvature, fluctuation, and extinction of the arc column, and destruction of the arc tube.

安定に点灯するためには、高圧放電灯が安定に点灯する
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, the high-pressure discharge lamp should be lit by selecting a frequency range in which it lights stably, but the frequency range in which it lights stably varies depending on the type of lamp, and it also differs for the same type of lamp. 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注等の問題がある。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 issues with ordering, etc.

（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
電灯を提供するにある。(Object of the invention) The present invention was made in order to eliminate the above-mentioned drawbacks.
The purpose is to provide a high-pressure discharge lamp in which unstable arcs due to acoustic resonance phenomena do not occur in the arc tube during high-frequency lighting.

（発明の開示） 本発明は、点灯時に発光管の管軸方向に温度差を生じさ
せる手段を発光管等に設け、音響的共鳴現象を回避した
ことを特徴とする。(Disclosure of the Invention) The present invention is characterized in that the arc tube or the like is provided with a means for generating a temperature difference in the axial direction of the arc tube during lighting, thereby avoiding the acoustic resonance phenomenon.

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。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.

θｒ　　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。θr z). Note that r represents the radial direction, θ represents the circumferential direction, and 2 represents the axial coordinate. 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／　（２ｒｃ　Ｒ
）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/ (2rc R
) θ-direction resonance: Fθ = 1.84C/ (2πR) 2-direction 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.

γ＝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。γ = Specific heat at constant pressure/Specific heat at constant volume P - Gas constant T - Temperature inside the arc tube M - Average mass of the sealed gas And a 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.

一般に高周波点灯する場合、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ＫＨｚ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、周方向が
主なものである。従って、本発明においては主として径
方向、周方向の共鳴現象について考えればよい。Generally, when lighting at a high frequency, the lighting frequency is several tens of KHz because the lighting is done while avoiding the audible frequency range. Acoustic resonance phenomena that occur in this frequency range are mainly in the radial and circumferential directions. Therefore, in the present invention, it is sufficient to mainly consider resonance phenomena in the radial direction and the circumferential direction.

また、一般に発光管内に立つ定在音波は、エネルギーが
最小になるように、周波数が低くなるような箇所に対応
して立とうとする。Furthermore, in general, standing sound waves within an arc tube tend to stand at locations where the frequency is low so that the energy is minimized.

而して、前述の径方向、周方向の周波数１ｒｒ。Thus, the frequency in the radial direction and the circumferential direction is 1rr.

Ｆθの式より明らかなように、周波数Ｆｒ、Ｆθはｆ”
；’／　Ｒに比例する。今、円筒形状の発光管を考え、
該発光管の半径Ｒを一定とすると、発光管内温度Ｔの低
い所で周波数Ｆｒ、Ｆθが小さくなるため、低温側へ定
在音波が集まってくる。計算機シミュレーションの結果
を第２図に示す。発光管１の管軸方向の温度分布を同図
（′ｂ）に示すようにｒ、ｎ、ｍと変化すると、管軸方
向の音圧分布は同図（Ｃ１，（ｄｉ、　（ｅｌに示すよ
うに、次第に低温側へと集まってくる。従って、発光管
の管軸方向に温度分布を作ることにより、低温側へ音圧
の高い部分を集めることができる。As is clear from the formula for Fθ, the frequency Fr and Fθ are f”
;'/ Proportional to R. Now, considering a cylindrical arc tube,
If the radius R of the arc tube is constant, the frequencies Fr and Fθ become smaller at locations where the temperature T inside the arc tube is low, so the standing sound waves gather toward the low temperature side. Figure 2 shows the results of the computer simulation. When the temperature distribution in the tube axis direction of arc tube 1 changes as r, n, and m as shown in the figure ('b), the sound pressure distribution in the tube axis direction changes as shown in the figure (C1, (di, (el) Therefore, by creating a temperature distribution in the axial direction of the arc tube, the parts with high sound pressure can be concentrated on the low temperature side.

実施例 以下、本発明に係る実施例について述べる。第３図に示
す実施例は、発光管１の外壁に、例えば酸化インジウム
（ＩｎＯ２）より成る保温膜を、同図に示すように膜厚
分布を管軸方向に変化させて塗布し、前記第３図（ｅｌ
に示すような温度分布を実現したものである。　　　　
′ 第４図に示す実施例は、高圧放電灯を垂直点灯した場合
に有効な例であり、外管８の内面であって、点灯時に上
側にくる略半分に保温１ｉ１０を塗布したものである。Examples Examples according to the present invention will be described below. In the embodiment shown in FIG. 3, a heat insulating film made of, for example, indium oxide (InO2) is applied to the outer wall of the arc tube 1, with the film thickness distribution changing in the tube axis direction as shown in the figure. Figure 3 (el
This achieves the temperature distribution shown in .
' The embodiment shown in Fig. 4 is an example that is effective when a high-pressure discharge lamp is lit vertically, and the heat-insulating 1i10 is applied to approximately half of the inner surface of the outer bulb 8 that is on the upper side when lit. .

第５図に示す実施例は、支持導線５ａ、５ｂに直列に接
続した加熱用ヒータ１１を、発光管１の外周であって、
いずれか一方の半分にのみ巻回したものである。In the embodiment shown in FIG.
It is wound only around one half.

以上のように構成した高圧放電灯を高周波点灯すると、
発光管１の管軸方向の温度分布は大きく変化し、前述の
ように、定在音波の発生箇所が発光管１の低温側に集ま
り、アーク柱への定在音波の影響を除去することができ
る。When the high-pressure discharge lamp configured as above is lit at high frequency,
The temperature distribution in the tube axis direction of the arc tube 1 changes greatly, and as mentioned above, the generation points of the standing sound waves gather on the low temperature side of the arc tube 1, making it possible to eliminate the influence of the standing sound waves on the arc column. can.

（発明の効果） 本発明は上記のように、点灯時に発光管の管軸方向に温
度差を生じさせる手段を設けたことにより、かかる高圧
放電灯を高周波点灯しても、音響的共鳴現象発生箇所を
避けてアーク柱が存在するため、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。(Effects of the Invention) As described above, the present invention provides a means for creating a temperature difference in the axial direction of the arc tube during lighting, so that even when such a high-pressure discharge lamp is lit at high frequency, an acoustic resonance phenomenon occurs. Since the arc column exists in a manner that avoids certain points, it is possible to prevent arc column curvature, fluctuation, extinguishing, and destruction of the arc tube, and it is possible to maintain stable lighting.

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

第１図は従来例の正面図、第２図は発光管の管軸方向の
温度分布に対応する音圧分布の計算機シミュレーション
結果で、（ａｌは発光管の正面図、（ｂ）は発光管の管
軸方向の温度分布図、（Ｃ１〜（Ｑ）はそれぞれ発光管
の管軸方向の音圧分布図、第３図は本発明の一実施例に
係る発光管と膜厚分布を示す図、第４図及び第５図はそ
れぞれ本発明の異なる実施例を示す正面図である。Figure 1 is a front view of the conventional example, and Figure 2 is a computer simulation result of the sound pressure distribution corresponding to the temperature distribution in the tube axis direction of the arc tube. (C1 to (Q) are respectively sound pressure distribution diagrams in the tube axis direction of the arc tube. Figure 3 is a diagram showing the arc tube and film thickness distribution according to an embodiment of the present invention. , 4 and 5 are front views showing different embodiments of the present invention, respectively.

Claims (1)

【特許請求の範囲】[Claims] （１）点灯した時、発光管の管軸方向の温度差が大きな
る手段を発光管に関連して設けことを特徴とする高圧放
電灯。(1) A high-pressure discharge lamp characterized in that a means is provided in conjunction with the arc tube to create a large temperature difference in the axial direction of the arc tube when the lamp is lit.