FR2562325A1 - LAMP, IN PARTICULAR SODIUM VAPOR LAMP OR HIGH-PRESSURE METAL HALIDE LAMP, FOR USE WITH CONTINUOUS POWER SUPPLY - Google Patents

Abstract

THE INVENTION RELATES TO A LAMP, IN PARTICULAR A SODIUM VAPOR LAMP OR A HIGH PRESSURE METAL HALOGENIDE LAMP, INTENDED TO OPERATE WITH A DC POWER SUPPLY. IN THIS LAMP MADE IN THE FORM OF A DISCHARGE ENCLOSURE 1 SURROUNDED BY AN EXTERNAL ENCLOSURE 2 AND CONTAINING IN ITS END ZONES AN ANODE 6 AND A CATHODE 7, AS WELL AS A FILLING GAS, THE ARRANGEMENT IS SUCH AS DURING THE OPERATION OF THE LAMP, THE COLD POINT LOCATED ON THE CATHODE 6 SIDE IS AT A TEMPERATURE ABOVE THE COLD POINT LOCATED ON THE ANODE 7 SIDE. APPLICATION ESPECIALLY TO HIGH PRESSURE DISCHARGE LAMPS.

Description

The invention relates to a lamp, in particular a lamp

  high-pressure sodium vapor or a halogen lamp

  metal nide intended to operate by being supplied with direct current and which is constituted by a discharge chamber, for example of tubular shape, made of a transparent material and preferably disposed inside an outer casing, the enclosure to discharge comprising, in its end regions, an anode and a cathode, as well as a filling gas, producing a pendant light

  functioning and constituted by at least two

killers formed of gas or vapor.

  Under the term metal halide lamp, generally refers to high-intensity discharge lamps

  pressure, which contain a rare gas as a means of

  mortification and mercury as well as the halide of at least one

  metal chosen appropriately. As a halide, it is

  usually read a mixture of sodium iodide, iodide

  of tallium, and indium iodide or a composition of

  hard sodium and scandium iodide or iodide

of dysprosium and tallium iodide.

  In the case of the DC power supply of conventional symmetrical metal halide lamps, which can be characterized by the same configuration

  anode and cathode, an important part of the

  gates move towards the cathode, which

  results in a separation of colors. This phenomenon is

  characterized in that on the one hand the ends of the luminescent body emit lights having different colors and on the other hand the lamp is sensitive to its position in space. In the case of vertically arranged metal halide lamps having a symmetrical electrode structure and containing sodium iodide, tallium iodide and indium iodide, the iodides of

  sodium are displaced, in the case of a cou-

  alternative, towards the lower zone of the

  with the effect that the lower part of the

  of the discharge becomes the source of an enlight-

  in yellow, the characteristic yellow

  tick of sodium determining the color. In the case of food

  dc flow of the same lamp, there are two possibilities. If the cathode is arranged in the lower position, the separation described above is very intense colors. If the cathode is placed in the upper position, the phenomenon is not manifested in a manner

also accused.

  Within the meaning of the present invention, a high-pressure sodium lamp designates a lighting element having a high-pressure discharge chamber made of a ceramic material with a high melting point and in which, during operation, a pressure

  sodium vapor of between 2 × 10 3 and 10 Pa, a pressure of

  mercury pressure between 0 and 5.105 Pa and a pressure

6 8

  xenon between 5.10 and 3.10 Pa. It is also customary to replace the mercury with another metal having a high molecular weight and a high vapor pressure, for example cadmium, and to use another gas instead of xenon. rare, for example argon or a mixture of rare gases consisting of neon and argon. These gases also form, for the purposes of the invention, vapor lamps

of sodium at high pressure.

  In the case of high-pressure sodium lamps

  high pressure metal halide lamps or

  sion, it often happens that when they are fed

  by a continuous current, they can not provide the

  usual color uniformity in the case of AC power supply, but that it appears as a result of

  phenomenon of electrophoresis or cataphoresis, the sepa-

  different components, which leads to a

  color separation. For example, sodium accumulates

  mule, as the most easily ionizable component, in the vicinity of the cathode, and that is why the other components also move. Therefore, the side of the cathode is enriched with sodium. This is the phenomenon of color separation, which is one of the causes of the fact that the DC power supply of high-pressure sodium lamps or halide lamps

  high pressure metal can not be extended. (The ex-

  This is the case where the separation of colors must

  be used sharply to obtain, for example, an exci-

  separation in space of such components, which

  provide illumination in different color ranges, such as mercury, cadmium, tallium and / or zinc in the sodium lamp. In this case the color separation causes an increase in the color temperature, but

  with a reduction in the output of the emitted light). The F-

  harmful effect of color separation can be reduced through the use of a matte outer envelope or

  of a luminous powder, which improves the uniformity

  mity of colors. Due to the permanent alternation of polarity, color separation is not as intense in sodium or halide vapor lamps

  metal powered by an alternating current.

  The object of the present invention is to provide a

  lamp structure to avoid or reduce the

  the above mentioned color separation - which, as is known, is to be attributed to the DC power supply and involves the spatial separation of the different components producing the light - in high-pressure sodium lamps and in lamps

  high pressure metal halide.

  The invention is based on the known fact that the desired phenomenon can be obtained in the case o during the operation of the sodium vapor lamp at high

  pressure or high-pressure metal halide lamp

  it is guaranteed to obtain a temperature of the point

  cold on the side of the discharge chamber, located towards the

  thode, higher than the temperature of the cold spot located on the side of the anode. Another known result that can be used in particular in the case of sodium vapor lamps lies in the fact that the ratio of the distance between the cathode and the anode serving as main electrodes of the lamp,

  and the inside diameter of the discharge vessel, is

  color separation, and that an appropriate range of values in this report also guarantees

  that the desired objective is achieved.

  It should be noted here that the temperature of the point

  cold means the temperature of the area of the indoor space

  the coldest discharge chamber, which is the coldest

in operation.

  Thus the object of the invention is to produce a lamp

  high-pressure sodium vapor or a halogen lamp

  high pressure metal genius, in which the known fact mentioned above is exploited and therefore can be avoided or at least reduce a permissible level the separation of colors, even in the case of a

DC power supply.

  According to a first aspect of the invention, this problem is solved by means of a lamp, in particular a high-pressure sodium or high-pressure metal halide lamp, intended to operate with a DC power supply and which is constituted by a discharge vessel preferably made of a transparent material and preferably disposed in an outer casing, the discharge vessel containing a cathode and anode serving as main electrodes and arranged in the zones

  end of this chamber, as well as a filling gas

  wise producing a light during operation and com-

  taking at least two constituents in the form of gas or vapor, characterized in that an arrangement is provided

  thanks to which, during the operation of the loudspeaker

  charge, the cold point located on the cathode side is at a temperature higher than the cold point present on the

the cathode.

  According to a second aspect of the present invention, the problem indicated above is solved with the aid of a lamp, in particular a high-pressure sodium vapor lamp or

  with a high pressure metal halide for

  being supplied with direct current and which is

  killed by a tubular shaped discharge chamber made of a transparent material, the discharge vessel containing, at its end regions, an anode and a cathode, and filling pad producing a light during operation and having two or more components

  of gas or steam, characterized in that the distance

  be the cathode and the anode is equal at most to sevenfold

  and preferably is equal to a maximum of five times the

  inside meter of the discharge chamber.

  In the case of an advantageous embodiment of the lam-

  high-pressure sodium or metal halide

  according to the invention, the distance between the end

  of the discharge chamber and the end of the main electrode, which is closest to it, that is to say the

  starting point of the arc, is smaller on the side of the

  thode, only on the side of the anode. The desired effect can also be

  This is due to the fact that the discharge vessel is narrower in the vicinity of the cathode than near the anode. Another advantageous solution lies in the fact that a heating element is provided which is

  near the cathode of the discharge chamber.

  Another advantageous solution is to use heat reflecting surfaces. Such a surface may be deposited for example exclusively in the vicinity of the cathode. But it is also possible to have

  a heat reflective surface both in the

  of the cathode in the vicinity of the anode or in the vicinity of the parts of the discharge vessel, which are

  anode and cathode, in which case it is possible to obtain

  the difference in the temperatures of the cold spots of

  different ways, for example by producing a surface layer with a greater thickness or with a

  greater thermal insulation capacity in the

  of the cathode than on the anode side, or by mounting a body having geometric dimensions, in the direction of the longitudinal axis of the discharge vessel, plus

  important on the cathode side than on the cathode side.

  According to a solution according to the invention, a fundamental advantage lies in the fact that the color separation along the longitudinal axis of the discharge chamber in the case of a DC supply of sodium vapor lamps at high pressure as well as

  high-pressure metal halide lamps are clearly

  can be greatly reduced, and uniformity of color distribution is guaranteed even in the case of a DC power supply. The combination of

  different solutions indicated above leads to an increase in

  increase of the effect that can be obtained, that is to say

  the uniformity of the color distribution.

  Other features and advantages of the present

  the invention will become apparent from the description given below

  reference is made to the accompanying drawings, in which:

  FIG. 1 represents the cross sectional view

  a high-pressure metal halide lamp con-

  form to the invention; - Figure 2 shows the cross section of a high-pressure sodium lamp made with a tubular discharge chamber; - Figure 3 shows the cross section of a

  high-pressure sodium vapor lamp having an or-

heater; and

  FIGS. 4 and 5 show the cross-sections

  of high-pressure sodium vapor lamps

  with the proposed dimensions.

  The high pressure metal halide lamp according to the invention, which is shown in FIG.

  1, is based on a construction that can be obtained

  the best color separation when placed vertically. The lamp contains a discharge vessel 1 located in an outer casing 2 and in

  which supports 3 and 4 are provided for use

  the discharge vessel 1 and connect this chamber by a head portion 5 to an anode 7 disposed in the anode zone inside the discharge chamber -1, and a cathode 6 disposed in an area cathode inside the enclosure. The supports 3 and 4 also guarantee the power supply. The high pressure metal halide lamp is used, as is the imageine, in a vertical position, the cathode 6 being placed at the top and the anode 7 at the bottom. As a result, the fact that the temperature of the cold point of the cathode zone is higher than the temperature of the cold point of the zone of the anode can already be obtained in itself. This effect can be further improved if the cathode 6 is placed in a position in which it is closer to the end of the discharge vessel.

  1 that is the anode 7 with respect to the opposite end.

  As is usual, the envelope 2 can be filled by

  a gas which is kept pure by means of a device

  In the embodiment according to the invention, heat-reflecting surfaces 10 and 11 may also be used, in which case the heat reflecting surface 10 located on the cathode side must be made to provide thermal reflection. more important than the

  surface 11 reflecting the heat and located on the side of the anode

  of. This surface 10 is made for example in the form

  a coating of zirconium oxide.

  The other figures represent different

  of the high-pressure sodium vapor lamp

  placed, which contains a discharge chamber 21 disposed in an outer casing and supports 23 and 24 holding this discharge chamber and ensuring by means of a head member 25 the power supply of this

  pregnant. The discharge vessel has a cathode 26 dis-

  placed in a cathode zone and an anode 27 disposed in an anode zone, and a degassing device 28 which is provided to eliminate the filling gas from the envelope

outside 22.

  According to FIG. 2, the desired phenomenon can be obtained thanks to the fact that the discharge vessel 21 is

  narrower on the cathode side than on the anode side.

  As a result, the temperature of the cold point on the cathode side can be increased, thereby avoiding color separation. As can be seen in Figure 3, it can be

  It is advantageous to have a heater 29 in the housing

  21 discharge belt of the high pressure sodium lamp. The heating member 29 is located on the cathode side, that is to say in the vicinity of the cathode 26, which makes it possible to increase the temperature of the cold spot in the vicinity

of the cathode.

  The embodiment, visible in FIG. 4, of the high-pressure sodium vapor lamp according to the invention is carried out in the same manner as that shown in FIG. 3, but instead of the heating member 29. ,

  a surface 30 reflecting the heat and

  by a ring of niobium in the vicinity of the cathode 26 of the discharge type. The nominal absorbed power of this high-pressure sodium lamp is 35 W. The discharge vessel 21 is constituted by a ceramic tube with a diameter of less than 3.3 mm, in which the distance between the cathode 26 and the anode 27 (the length of the arc) is equal to 40 mm, and the width of the niobium ring is equal to 6 mm. This means that the ratio of the distance between the main electrodes (the cathode

  and the anode) at the inner diameter is about 12.1.

  In these conditions of relationship, therefore, it can very frequently happen that the separation of colors is

  very important, in the case where no action is taken.

  In the case of a known light source according to the state of the art, only half of the discharge chamber would illuminate as a sodium vapor lamp in the

  remaining part of which we would see the specter of the

  charge in mercury. In the case of the use of

  mentioned heater 29 or the niobium ring as a radiation reflective surface, one avoids

  almost completely the separation of colors.

  Visible high pressure sodium vapor lamp

  in Figure 5 is dimensioned so that the

  The rate between the cathode 26 and the anode 27 is equal to only 10 mm, and the inside diameter of the discharge vessel 21 is equal to 3.3 mm. So the ratio of the distance between the main electrodes and the inside diameter

  the discharge chamber is set to a value equal to

  3. As the observation shows, there is no separation of colors and therefore the favorable choice

  dimension is in itself sufficient to achieve the desired effect.

  sought. It is obvious that this provision can be supplemented by the previous ones and that the separation of colors in the lamps can be effectively avoided.

  sodium vapor at high pressure.

  The proposed constitution according to the invention for high-pressure sodium lamps or for

  high-pressure metal halide lamps allows the

  use of these lamps also in the case of a

  DC operation without any risk of occurrence

a separation of colors.

Claims (10)

  1. Lamp, especially & sodium vapor & high pres-   high-pressure metal halide or metal halide, intended to operate with a DC power supply and which consists of a discharge vessel constructed   preferably a transparent material and arranged   in an outer casing, the discharge chamber   containing a cathode and anode as primary electrodes   and located in the end areas of this area.   surrounded by a filling gas producing a   during operation and comprising at least two constituents in the form of gas or vapor, characterized in that an arrangement is provided by which, during the operation of the discharge vessel (1, 21), the point   the cold side of the cathode (6, 26) is at a temperature of   higher than the cold point on the anode side (7, 27).   2. Lamp, especially with sodium vapor at high pressure   high-pressure metal halide or metal halide according to claim 1, characterized in that the distance between   the end of the discharge chamber and the end of the   and the mainstage, which is closest to it, that is,   say the starting point of the bow, is smaller on the side   of the cathode (6, 26) only on the side of the anode (7, 27).   3. Lamp, especially sodium vapor at high pressure   high-pressure metal halide or metal halide according to   claims 1 or 2, characterized in that the enclosure   (1, 21) has a narrower shape in the vicinity of   swimming the cathode (6, 26) in the vicinity of the anode (7, 27).   4. Lamp, especially with sodium vapor at high pressure   high-pressure metal halide or metal halide, in accordance with   any of claims 1 to 3, characterized in that   it comprises a heating element (29) which is   in the vicinity of the cathode (6, 26) of the enclosure charge (1, 21).   5. Lamp, especially with sodium vapor at high pressure   high-pressure metal halide or metal halide, in accordance with   any of claims 1 to 4, characterized in that   heat reflecting surface (10, 30) is disposed exclusively in the vicinity of the cathode (6, 26) of the enclosure for discharge (1, 21).   6. Lamp, especially with sodium vapor at high pressure   high-pressure metal halide or metal halide, in accordance with   any of claims 1 to 4, characterized in that   surfaces (10, 11, 30) reflecting the heat are dis-   placed in the vicinity of the cathode (6, 26) and the anode (7, 27) of the discharge vessel (1, 21), the heat reflection produced by the surface (10, 30) reflecting the heat the cathode (6, 26) being higher than the heat reflection of the reflective surface (11)   heat, near the anode (7,27).   7. Lamp, especially with sodium vapor at high pressure   high-pressure metal halide or metal halide, in accordance with   any of claims 1 to 4, characterized in that   heat-reflecting surface (10, 11, 30) is disposed adjacent the portions of the discharge vessel (1, 21) facing the cathode (6.26) and anode (7.27) side, each of said surfaces being in the form of a layer which on the side facing the cathode (6,26) has a greater thickness   only on the side facing the anode (7,27).   8. Lamp, especially high pressure sodium vapor   high-pressure metal halide or metal halide, in accordance with   any of claims 1 to 4, characterized in that   heat-reflecting surface (10, 11, 30) is disposed adjacent the portions of the discharge vessel facing the cathode (6, 26) and the anode (7, 27), each of said surfaces being made under the shape of a layer that, on the side   turned towards the cathode (6,26) has a heating capacity   more than the side facing the anode (7,27).   9. Lamp, especially with sodium vapor at high pressure   high-pressure metal halide or metal halide, in accordance with   any of claims 1 to 4, characterized in that   a surface (10, 11, 30) reflecting heat to the   sinuous parts of the discharge chamber (1, 21),   towards the cathode (6, 26) and towards the anode (7, 27) is achieved.   born in the form of a body that has turned side   to the cathode (7, 27) in the direction of the long axis   of the discharge vessel (1, 21), geometric dimensions larger than the side facing the anode (7, 27).   10. Lamp, especially with sodium vapor at high pressure   high-pressure metal halide or metal halide intended to operate with direct current   consists of a tubular discharge chamber   made of a transparent material, the enclosure to be de-   containing, at its end zones, a   anode and a cathode, as well as a filling gas   a light during operation and having at least two gas or vapor components, characterized in that the distance between the cathode (6, 26) and the anode (7, 27) is at most seven times and preferably is equal to not more than five times the inner diameter of the discharge vessel (1, 21).