JPS60189152A - High pressure sodium lamp - Google Patents

Abstract

PURPOSE:To reduce the difference between the emission spectra in different directions by making the downside wall area of an emission tube bulb made of a high-transmitting ceramic more transparent than the upside wall area. CONSTITUTION:An about half area 4a of the outer circumference of an emission tube bulb 4 made of a light-transmitting alumina ceramic which has a semicylindrical shape extending along the entire length of the bulb 4, is smoothed by chemically polishing by electric welding polishing or similar method so that the area 4a is more transparent than the other half area 4b. By lighting a lamp with the above structure while horizontally positioning the emission tube with its chemically polished area 4a located downside, it is possible to reduce the difference between emission spectra discharged upward and downward. As a result, there is only little spectral variation in the whole emission tube, thereby reducing color shading occuring on the irradiated body.

Description

【発明の詳細な説明】 〔発明の技術分野〕 本発明は透光性セラミクスを発光管バルブとする高圧ナ
トリウムランプに関する。DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a high-pressure sodium lamp whose arc tube bulb is made of translucent ceramics.

〔発明の技術的背景とその問題点〕[Technical background of the invention and its problems]

透光性セラミクス管たとえば透光性アルミナセラミクス
管を発光管バルブとし始動用希ガス、水銀およびナトリ
ウムを封入した発光管を備えた高圧ナトリウムランプは
、そめランプ効率が高いことから省エネルギー光源とし
て電球、けい光ランプ、水銀ランプなどに代わって多く
の分野に用いられている。しかし、一般の高圧ナトリウ
ムランプは高いランプ効率に較べて演色性が平均演色評
価数Ｒａで約２８と低いため、室内照明などの演色性を
重視する場所には満足できるものではなかった。これに
対処して近年２点灯中のナトリウム蒸気圧を約３００　
Ｔｏｒｒ　ｔで高めてＲａが約８５と演色性を大巾に向
上するとともに色温度を２５００にと電球のそれに近づ
けた高演色形の高圧ナトリウムランプが商品化され、こ
の種ランプの用途は一層拡大されている。High-pressure sodium lamps are equipped with a light-transmitting ceramic tube, for example, a light-transmitting alumina ceramic tube is used as the arc tube bulb, and the arc tube is filled with a rare starting gas, mercury, and sodium.Because of its high lamp efficiency, it can be used as a light bulb or as an energy-saving light source. It is used in many fields in place of fluorescent lamps, mercury lamps, etc. However, compared to high lamp efficiency, general high-pressure sodium lamps have a low color rendering property of about 28 in average color rendering index Ra, so they are not satisfactory for places where color rendering is important, such as indoor lighting. To deal with this, in recent years the sodium vapor pressure during 2 lighting has been reduced to about 300.
A high pressure sodium lamp with a high color rendering type was commercialized, which greatly improved the color rendering property by increasing the Torr t to approximately 85, and brought the color temperature to 2500, which was close to that of a light bulb.The uses of this type of lamp were further expanded. has been done.

ところで、上記高原色形高圧ナトリウムランプは一般の
高圧ナトリウムランプに較べ点灯中のす゛トリウムの蒸
気圧を高めることによって発光スペクトル分布の幅を広
げ、また発光管パルプの管径を太くすることＫよってナ
トリウムの自己吸収を大きくして演色性や色温度を高め
る構造となっている。By the way, compared to general high-pressure sodium lamps, the above-mentioned plateau color type high-pressure sodium lamp widens the width of the emission spectrum distribution by increasing the vapor pressure of sodium thorium during lighting, and also by increasing the diameter of the arc tube pulp. It has a structure that increases self-absorption of sodium and increases color rendering and color temperature.

しかしながら、このような高原色形高圧ナトリウムラン
プをその発光管が水平となるような位置で点灯使用した
場合２発光管の上部方向に放射される光、下部方向に放
射される光および水平方向に放射される光とではそれぞ
れ演色性や色温度に相違をきたし、投光器などを用いて
照明する際に被照射体に色むらが生じるという欠点があ
る。この理由は上記のように太管の発光管バルブ内で生
じたアーク放電は、その対流現象によって水平の発光管
パルプの中心から上方に浮き上った状態となシ、アーク
の周辺に存在するナトリウム蒸気層などの非発光部層の
厚さはアークの上方では薄く。However, when such a high-pressure sodium lamp with high primary colors is lit in a position where its arc tube is horizontal, two types of light are emitted in the upper direction of the arc tube, light is emitted in the lower direction, and light is emitted in the horizontal direction. The emitted light has a different color rendering property and color temperature, and has the disadvantage that color unevenness occurs on the irradiated object when illuminated with a projector or the like. The reason for this is that, as mentioned above, the arc discharge that occurs inside the thick arc tube bulb floats upward from the center of the horizontal arc tube pulp due to the convection phenomenon, and exists around the arc. The thickness of non-emissive layers such as the sodium vapor layer is thinner above the arc.

下方では厚くなシ、シたがってアーク放電によって生じ
た光の非発光部層による吸収の割合は特にアークの上方
向と下方向とでは異なってくる。すなわち、アークの上
方向では光吸収（特にはナトリウムＤ線の吸収幅）が少
ないため演色性は悪く。The layer is thicker in the lower part, so the rate of absorption of light generated by the arc discharge by the non-light emitting layer is different particularly in the upper and lower parts of the arc. That is, in the upper direction of the arc, light absorption (particularly the absorption width of the sodium D line) is small, so the color rendering properties are poor.

色温度は低下し、一方、アークの下方向では上方向とは
逆に上記光吸収が多過ぎるため、これまた演色性は悪く
なり１色温度の方は高くなるためである。これに対し、
水平方向の光はほぼ定格通りの演色性と色温度が得られ
る。This is because the color temperature decreases, and on the other hand, in the downward direction of the arc, contrary to the upward direction, the above-mentioned light absorption is too large, so that the color rendering property also deteriorates and the color temperature becomes higher. On the other hand,
Horizontal light provides almost the same color rendering and color temperature as rated.

〔発明の目的〕[Purpose of the invention]

本発明は上記欠点に対処してなされたもので。 The present invention has been made to address the above drawbacks.

発光管を水平位置で点灯した場合に発光管から放射され
る光の発光色の放射方向による差違が少くない高演色形
の高圧ナトリウムランプを提供することを目的とする。An object of the present invention is to provide a high-pressure sodium lamp of a high color rendering type in which the color of light emitted from an arc tube does not vary much depending on the radiation direction when the arc tube is lit in a horizontal position.

〔発明の概要〕[Summary of the invention]

本発明は発光管が水平位置になるような形態で点灯した
場合に下側になる透光性セラミクス製発光管バルブの管
壁部分をその管長方向の少なくとも電極間部分にわたっ
て上側の管壁部分よりも透明度が高くなるように形成し
たことを特徴とする。　。In the present invention, when the arc tube is lit in a horizontal position, the lower tube wall portion of the light-transmitting ceramic arc tube bulb is lower than the upper tube wall portion over at least the portion between the electrodes in the tube length direction. It is also characterized by being formed to have high transparency. .

〔発明の実施例〕[Embodiments of the invention]

以下１本発明の一実施例を図面を参照して説明する。 An embodiment of the present invention will be described below with reference to the drawings.

第１図は定格４００　Ｗの高演色形の高圧ナトリウムラ
ンプの正面図、第２図は同発光管バルブの横断面図を示
す。FIG. 1 shows a front view of a high-pressure sodium lamp with a high color rendering type having a rating of 400 W, and FIG. 2 shows a cross-sectional view of the arc tube bulb.

図において（１）は内部を高真空に保ち、一端に口金（
２）を装着した硬質ガラスからなる外管、（３）は発光
管で、透光性セラミクスたとえば透光性アルミナセラミ
クスからなる発光管バルブ（４）の両端部は金属管（５
ａ）　、　（５ｂ）を介して電極（６ａ）、　（６ｂ）
を支持する閉塞体（７ａ）　、　（’７ｂ）によシガラ
スソルダ等の封着材を介して気密に封止され、がっ、そ
の内部にはナトリウムが２９重量％のアマルガムが３５
ｍｇと始動用希ガスとしてたとえば（ネオン−アルゴン
）の混合ガスが３０Ｔｏｒｒ封入されている。In the figure, (1) maintains a high vacuum inside and has a cap (
2) is an outer bulb made of hard glass, (3) is an arc tube, and both ends of the arc tube bulb (4) made of translucent ceramics, such as translucent alumina ceramics, are fitted with metal tubes (5).
a), (5b) via electrodes (6a), (6b)
The closed bodies (7a) and ('7b) that support the
A mixed gas of (neon-argon) as a rare gas for starting is sealed at 30 Torr.

まだ（８）は保温板、（９）はゲッタ、αｌは発光管（
３）に巻回された耐熱性金属線からなる始動補助導体、
（１υは点灯後に発光管の熱によりバイメタルが開いて
始動補助導体（ＩＩの電位の印加をなくするバイメタル
ユニットである。Still (8) is a heat insulating plate, (9) is a getter, and αl is an arc tube (
3) a starting auxiliary conductor consisting of a heat-resistant metal wire wound on the
(1υ is a bimetal unit that opens the bimetal due to the heat of the arc tube after lighting, eliminating the application of potential to the starting auxiliary conductor (II).

なお、上記透光性アルミナセラミクスからなる発光管パ
ルプ（４ンは第２図に示すようにその周面約半分の図中
（４ａ）で示した部分がバルブの全長方向にわたってた
とえば電気溶融研磨法で化学研磨されてその表面は平滑
化され、他の半分の管壁部分（４ｂ）よシも透明度が高
く形成されている。」記電気溶融研磨法とはほう砂を電
気溶融し、この中に透光性アルミナセラミクスからなる
発光管パルプの全長にわたシ周面の約半分を２分間程浸
漬した後、上記バルブに付着しているほう砂を希酸で処
理する方法である。Incidentally, as shown in FIG. 2, the arc tube pulp made of the above-mentioned translucent alumina ceramics (as shown in FIG. The other half of the pipe wall (4b) is also chemically polished to make its surface smooth and highly transparent. In this method, about half of the circumferential surface of the arc tube pulp made of translucent alumina ceramics is immersed for about 2 minutes for about 2 minutes, and then the borax adhering to the bulb is treated with dilute acid.

第３図は上記化学研磨を施した管壁部分（４ａ）と化学
研磨をしない管壁部分（４ｂ）との直線透過率を比較し
て示す図で、縦軸は直線透過率を、横軸は波長（ｎｍ）
をそれぞれ示す。この図から叩らかな通り、化学研磨を
施した管壁部分（４ａ）は。Figure 3 is a diagram showing a comparison of the linear transmittance of the tube wall portion (4a) subjected to chemical polishing and the tube wall portion (4b) not chemically polished, where the vertical axis represents the linear transmittance and the horizontal axis is the wavelength (nm)
are shown respectively. As you can clearly see from this figure, the tube wall portion (4a) has been chemically polished.

他の管壁部分（４ｂ）に較べて極めて直線透過率が高く
なっている。つまシ管壁表面における光の多重反射が少
なくなっていることが判る。The in-line transmittance is extremely high compared to the other tube wall portions (4b). It can be seen that multiple reflections of light on the tube wall surface are reduced.

このような構成のランプを上記発光管パルプ（４）の化
学研磨した管壁部分（４ａ）が下側になるような発光管
水平位置で点灯すれば、電極（６ａ）、（６ｂ）間に生
じるアークは従来ランプと同様に発光管パルプ（４）の
中心から上方に浮き上った状態となシ。If a lamp with such a configuration is lit in a horizontal position of the arc tube with the chemically polished tube wall portion (4a) of the arc tube pulp (4) facing downward, there will be a gap between the electrodes (6a) and (6b). The generated arc floats upward from the center of the arc tube pulp (4), similar to conventional lamps.

アークの周辺に存在するナトリウム蒸気層などの非発光
部層の厚さはアークの上方では薄く、下方では厚い。し
たがってアークで発生した光の非発光部層による吸収（
特にはす）　ＩＪウムＤ線の吸収幅）の割合は、アーク
の上、下方向ではそれぞれ相違する。このような状態で
発光管（３）から管外へ放射される光を比較するに、ア
ークの上方に向う光は非発光部層における１次吸収量こ
そ少ないが。The thickness of the non-luminescent layer such as the sodium vapor layer that exists around the arc is thin above the arc and thick below it. Therefore, the absorption (
In particular, the ratio of the absorption width of the IJumD line is different in the upper and lower directions of the arc. Comparing the light emitted from the arc tube (3) to the outside of the tube in this state, the amount of primary absorption in the non-light emitting layer of the light directed above the arc is small.

表面が平滑でない上側管壁部分（４ｂ）で多重反射され
て反射光がさらに非発光部層で吸収される２次吸収量が
多くなる。これは従来ランプと同様である。これに対し
、アークの下方に向う光は厚い非発光部層による１次吸
収量は上方に向う光よりも多いが、一方、下側管壁部分
（４ａ）は表面が平滑化され透明度が高く形成されてい
るので、光の多重反射は少なく、シたがって反射光の非
発光部層における２次吸収量は上方に向う光の場合より
もはるかに少なくなり、結局のところ上記１次吸収に２
次吸収を加味すると、上、下方向の光吸収の差違は従来
のものより著るしく小さくすることができる。The reflected light is subjected to multiple reflections at the upper tube wall portion (4b) whose surface is not smooth, and the amount of secondary absorption in which the reflected light is further absorbed by the non-light emitting layer increases. This is similar to conventional lamps. On the other hand, the amount of primary absorption of light directed downward by the arc due to the thick non-emissive layer is greater than that of light directed upward, but on the other hand, the lower tube wall portion (4a) has a smooth surface and high transparency. Because of this structure, there is less multiple reflection of light, and therefore, the amount of secondary absorption of reflected light in the non-emitting layer is much smaller than that of light directed upwards, and ultimately the above-mentioned primary absorption 2
When the next absorption is taken into account, the difference in light absorption in the upper and lower directions can be made significantly smaller than in the conventional case.

この実施例ランプと化学研磨を施さない従来−ランプと
につき９発光管の上方から放射される光および下方から
放射される光の各発光色を発光管の水平方向から放射さ
れる光の発光色（はぼ定格値）と比較した結果を下表に
示す。Ｒａは（平均演色評価数）、Ｔｃは（色温度Ｋ）
をそれぞれ示す。For this example lamp and a conventional lamp that does not undergo chemical polishing, 9 each emission color of light emitted from above and below of the arc tube is compared to the emission color of light emitted from the horizontal direction of the arc tube. (Habo rated value) The results of comparison are shown in the table below. Ra is (average color rendering index), Tc is (color temperature K)
are shown respectively.

表 表よシＲａに関する水平方向と（上２丁）方向との差は
従来例では（８５−７９）−６であるのに対し。In contrast to the conventional example, the difference between the horizontal direction and the (upper 2nd direction) direction with respect to Ra is (85-79)-6.

実施例では（８５−８１）＝４でその差が縮甘っている
ことが別る。In the embodiment, the difference is that (85-81)=4, which makes the difference narrower.

またＴ。に関する水平方向と（上、下）方向との差は従
来例では２５００Ｋ　−２３５０Ｋ（上方向）　＝　１
４５０に、２５００に一２６５０Ｋ（下方向）　＝　−
１５０にであるから、差の絶対値の和は１５０に＋１５
０に＝　３００にとなる。T again. In the conventional example, the difference between the horizontal direction and the (upward, downward) direction is 2500K - 2350K (upward direction) = 1
450, 2500 - 2650K (downward) = -
Since it is 150, the sum of the absolute values of the differences is 150 + 15
0 = 300.

これに対し、実施例では２５００に−２３５０Ｋ（上方
向）＝　１５０Ｋ　、　２５００に一２５００Ｋ　（下
方向）−〇であるから、上記差の絶対値の和は１５０に
＋　ＯＫ＝　１５０にで。On the other hand, in the example, since 2500 -2350K (upward) = 150K and 2500 -2500K (downward) - 0, the sum of the absolute values of the above differences is 150 + OK = 150.

従来例の１／２にまで縮まっていることが判る。したが
って１本発明によれば、几ａｔ’ｒｃについて著るしい
効果が得られることは明白である。It can be seen that the size is reduced to 1/2 of that of the conventional example. Therefore, it is clear that according to the present invention, a significant effect can be obtained regarding at'rc.

なお、上記実施例では発光管バルブの透明度を高める手
段として化学研磨法を用いたが２機械研磨法など他の手
段によっても良いし、また透明度を高める部分は発光管
バルブの最下点（第２図のＡ点）を中心にして局面の１
／３〜２／３程度の範囲で、かつ管長方向としては少な
くともアーク放電が生じる範囲つｔｊ）電極間部分にわ
たっていれば良い。すなわち９周面の１／３未満では透
明度を高めた効果が不充分となシ、一方２／３を越える
と発光管バルブの上方部管壁の相当部分までもが透明度
が高くなってしまい、上方向と下方向との発光色の差が
広がる結果となってしまうからである。In the above embodiment, a chemical polishing method was used as a means to increase the transparency of the arc tube bulb, but other methods such as mechanical polishing may also be used. 1 of the position centered on point A in Figure 2)
2/3 to 2/3, and in the length direction of the tube, at least the range where arc discharge occurs and the part between the electrodes. In other words, if it is less than 1/3 of the circumferential surface, the effect of increasing transparency will be insufficient, whereas if it exceeds 2/3, even a considerable part of the upper tube wall of the arc tube bulb will become highly transparent. This is because the difference in emitted light color between the upper direction and the lower direction becomes wider.

また、管長方向の規制は光の発生源であるアーク放電が
電極間で生じるからである。Further, the restriction in the tube length direction is because arc discharge, which is the source of light, occurs between the electrodes.

さらに、ランプ入力も上記４００Ｗに限らず高演色形の
他の入力のランプにおいても同様の効果が得られるもの
である。Furthermore, the lamp input is not limited to the above-mentioned 400W, but similar effects can be obtained with lamps with other high color rendering inputs.

〔発明の効果〕〔Effect of the invention〕

以上詳述したように２本発明によれば水平点灯時に下側
となる発光管管壁の透明度を上側の管壁のそれよりも高
くなるように形成しだので２発光管の上方および下方へ
放射される光の発光色の差違を縮めることができ、した
がって発光管全体としての発光色の変動が少なく、被照
射体に生じる色むらを減少することができる水平点灯用
の高演色形高圧ナトリウムランプが得られる。As described in detail above, according to the present invention, the transparency of the lower wall of the arc tube during horizontal lighting is made higher than that of the upper wall of the arc tube. High-pressure sodium with high color rendering for horizontal lighting that can reduce the difference in the color of the emitted light, thus reducing the variation in the color of the light emitted from the arc tube as a whole, and reducing the color unevenness that occurs on the irradiated object. You will get a lamp.

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

第１図は本発明の一実施例である４００Ｗの高演色形高
圧ナトリウムランプの正面図、第２図は同ランプの発光
管パルプの断面図、第３図は同じく同ランプ発光管バル
ブの上部管壁と下部管壁との直線透過率の比較図をそれ
ぞれ示すものである。 （１）・・・・・・外管、（３）・・・・・・発光管、
（４）・・・・・・発光管パルプ。 （４ａ）・・・・・・発光管パルプの化学研磨した管壁
部分（４ｂ）：・・・・・発光管パルプの化学研磨しな
い管壁部分代理人　弁理士　則近憲佑 （ほか　１名） 第１図 ８　６ａ 第２図Fig. 1 is a front view of a 400W high color rendering type high pressure sodium lamp which is an embodiment of the present invention, Fig. 2 is a sectional view of the arc tube pulp of the lamp, and Fig. 3 is the upper part of the arc tube bulb of the same lamp. 2A and 2B are diagrams showing comparisons of straight-line transmittance between the tube wall and the lower tube wall, respectively. (1)... Outer tube, (3)... Arc tube,
(4)... Arc tube pulp. (4a)... Chemically polished tube wall portion of arc tube pulp (4b):... Tube wall portion of arc tube pulp that is not chemically polished Agent: Kensuke Norichika, patent attorney (and one other person) ) Figure 1 8 6a Figure 2

Claims (1)

【特許請求の範囲】[Claims] 透光性セラミクスからなる発光管パルプの両端に一対の
電極を対設し、内部に始動用希ガス、水銀およびナトリ
ウムを封入した発光管を備え、上記発光管を水平位置で
点灯する場合に２発光管パルプの下側の管壁部分が管長
方向の少なくとも電極間部分にわたって上側の管壁部分
よりも透明度が高くなるように形成されていることを特
徴とする高圧ナトリウムランプ。A pair of electrodes are provided at both ends of an arc tube pulp made of translucent ceramics, and the arc tube is filled with a starting rare gas, mercury, and sodium. A high-pressure sodium lamp characterized in that the lower tube wall portion of the arc tube pulp is formed to have higher transparency than the upper tube wall portion over at least the portion between the electrodes in the tube length direction.