JP5305051B2 - Ceramic metal halide lamp lighting device - Google Patents

Description

  The present invention relates to a ceramic metal halide lamp lighting device. More specifically, the present invention relates to reduction of restart time or realization of instantaneous restart of a ceramic metal halide lamp illumination device having a plurality of arc tubes and only one arc tube that is always lit.

  High-intensity discharge lamps (hereinafter referred to as “HID lamps”) such as high-pressure mercury lamps, high-pressure sodium lamps, metal halide lamps, and ceramic metal halide lamps emit light using discharge between electrodes. Since the luminous flux is larger than incandescent bulbs, it has various features such as being suitable for lighting in a large-scale space and having high energy efficiency. Therefore, it is generally widely used as lighting for roads, shops, factories, etc., location lighting for televisions and movies, and headlights for automobiles and railway vehicles.

  In the HID lamp, metal halide lamps that employ metal halides as luminescent materials have advantages such as excellent color rendering and high luminous efficiency that are close to white light (natural light) compared to high-pressure mercury lamps that emit pale light. Yes. Conventionally, quartz arc tubes have been used as arc tubes for metal halide lamps.

  Recently, a light-emitting ceramic arc tube has been used as the arc tube. The translucent ceramic arc tube can have a much longer life than a quartz arc tube. For example, a single translucent ceramic arc tube can secure a lifetime of 24,000 hours. Furthermore, since the material ceramics does not react with the metal halide sealed in the arc tube, there are advantages that various metal halides can be used and that the heat resistance is good.

  A metal halide lamp using an arc tube made of translucent ceramics is particularly called a “ceramic metal halide lamp”.

  The present inventors are aware of the following patent document as a prior art document relating to shortening the restart time of the ceramic metal halide lamp.

JP-A-49-17077 (Publication date: February 15, 1974) "Multi-arc tube lamp" (Applicant: General Electric Company) Japanese Patent Laid-Open No. 10-12388 (Publication Date: January 16, 1998) “High Pressure Sodium Lamp, High Pressure Sodium Lamp Lighting Circuit and Lighting Device” (Applicant: Toshiba Lighting Corporation) JP 2006-100089 (publication date: April 13, 2006) "Ceramic metal halide lamp" (Applicant: Hitachi Lighting Co., Ltd.)

  There is a demand for longer life for lamps in general. In order to meet the demand for longer life, the present inventors enclose two arc tubes in the outer bulb of one lamp, and a ceramic metal halide lamp in which only one arc tube is always lit. Has been researching and developing. For example, if a lamp in which only one of the two arc tubes is always turned on is theoretically expected to have a long life of 48,000 hours.

  However, in a ceramic metal halide lamp, when the arc tube that is turned on is turned off and restarted, the arc tube is in a high temperature state, so the time required for restart is relatively long, and usually requires about 15 minutes or more. Even when two light-emitting tubes are enclosed and the light-emitting tubes are alternately turned on (that is, even when one of the light-emitting tubes is turned off and the other light-emitting tube that has been turned off is restarted), about 8 Need more than a minute. Due to the heat transfer from the adjacent lighting arc tube, the other arc tube seems to be in a considerably high temperature state even when it is extinguished.

  Therefore, shortening the restart time has become a very important development theme for ceramic metal halide lamps.

  The above-mentioned Patent Documents 1 to 3 are provided with a translucent heat shielding member that increases the pulse voltage, which is a feature of the present invention, and further suppresses heat transfer from the arc tube during light emission to the adjacent arc tube. There is no description regarding ceramic metal halide lamps.

  In view of the above-described problems, the present invention achieves reduction in restart time and instantaneous restart in a ceramic metal halide lamp lighting device in which only one arc tube that is easily lit among a plurality of arc tubes is lit. Objective.

  The ceramic metal halide lamp illuminating device according to the present invention is an illuminating device including a ceramic metal halide lamp and a drive circuit. The ceramic metal halide lamp has a plurality of arc tubes in one outer sphere and is always easily lit. This is a lamp in which only one arc tube is turned on, and in order to suppress heat transfer from one arc tube that is lit to the other arc tube that is extinguished, light is transmitted between the plural arc tubes. A heat shielding member is disposed, and the driving circuit applies a pulse voltage of 2.5 to 4.5 kV to the lamp during restart.

  Furthermore, in the lighting device, the driving circuit may apply a pulse voltage of 3.0 to 4.5 kV to the lamp during restart.

  Furthermore, in the said illuminating device, the said translucent heat shielding member may consist of quartz glass.

  Furthermore, in the said illuminating device, the said translucent heat shielding member may be a plate-shaped object.

  Furthermore, in the illumination device, the translucent heat shielding member may be a cylindrical member surrounding each arc tube.

  Furthermore, in the above-mentioned lighting device, the translucent heat shielding member is a member surrounding each arc tube, and is formed by combining two test tube-shaped glass tubes having slightly different diameters. May be cylindrical and both ends may be rounded.

  Further, in the lighting device, the lamp may be a lamp having an output of 190 W.

  ADVANTAGE OF THE INVENTION According to this invention, in the ceramic metal halide lamp illuminating device in which only one arc tube which is easily lit among two or more arc tubes is lit, the restart time can be shortened and instantaneous restart can be realized. .

FIG. 1 is a diagram for explaining a configuration of a ceramic metal halide lamp in which two current arc tubes are enclosed. FIG. 2 is a graph illustrating pulse voltage-restart time characteristics when the pulse voltage is sequentially increased in the lamp shown in FIG. FIG. 3 is a graph for explaining the pulse voltage-restart time characteristic when the temperature of the other lamp is suppressed using the light-transmitting heat shielding member and the pulse voltage is sequentially increased in the lamp shown in FIG. It is. FIG. 4 is a diagram illustrating the configuration of the ceramic metal halide lamp according to the present embodiment. FIG. 5 is a view showing another embodiment of the translucent heat diffusing member shown in FIG. FIG. 6 is a diagram illustrating a circuit of a metal halide lamp.

  Hereinafter, embodiments of a ceramic metal halide lamp according to the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted.

[Current ceramic metal halide lamps and their restart characteristics]
FIG. 1 is a diagram for explaining a configuration of a ceramic metal halide lamp 10 in which two current arc tubes are enclosed. As shown in the figure, the lamp 10 has two arc tubes 4-1 and 4-2 enclosed inside an outer bulb 2. A base 6 is joined to one end of the outer sphere 2. Each arc tube 4-1 and 4-2 is supported at a predetermined position by a mount 8.

  The arc tubes 4-1 and 4-2 are both made of translucent ceramics, the maximum outer diameter of the light emitting portion is 15.2 mm, and the shortest distance of the outer surface is 10.8 mm. In this way, the two arc tubes are arranged adjacent to each other at a close distance.

  The outer sphere 2 is made of translucent hard glass such as borosilicate glass, for example. The outer sphere 2 has a BT shape having a central portion of the maximum diameter, a lower top portion as viewed in the figure, and a neck portion connected to the upper base. The outer sphere 2 includes a transparent outer sphere that linearly transmits the light from the arc tube 4 as it is, and a diffusion outer sphere that diffuses and transmits the light to some extent with a white frosted glass inner surface. is there.

  In this application document, “starting” refers to lighting the arc tube in a low temperature state (that is, the lamp is in the same state as the normal outside air temperature, room temperature, etc.). “Restart” refers to turning off a lamp that has been turned on once, and then turning on a light-emitting tube in a high temperature state before sufficiently cooling. Examples of the lamp in the high temperature include a lamp in a case where an extinguished arc tube is turned on again in a short time, and an extinguished adjacent arc tube heated by an lit arc tube is turned on.

  In a ceramic metal halide lamp in which two arc tubes are enclosed, the arc tube that is lit is referred to as “one arc tube”, and the arc tube that is not lit is referred to as “the other arc tube”.

  In the ceramic metal halide lamp 10 in which the two arc tubes 4-1 and 4-2 are enclosed, when a re-lighting operation is performed immediately after the lamp is extinguished, or when the life of one arc tube (during lighting) is exhausted, the other When the arc tube (turned off) is lit, the time required for restarting is usually about 8 minutes.

  The inventors of the present invention recognize that the fact that the temperature of the gas enclosed in the other arc tube rises due to heat transfer from the one arc tube is a cause that cannot be restarted in a short time. Furthermore, in conventional high-pressure sodium lamps and the like, the outer bulb is in a vacuum state, so the amount of heat transferred by heat radiation between the two arc tubes is very small. Recognizes that since it is filled with a predetermined inert gas (typically argon Ar, nitrogen N), the amount of heat transfer is large, making restarting in a short time even more difficult. The gas pressure is in the range of 20 to 70 kPa. When the pressure is less than 20 kPa, when one of the arc tubes leaks, there is a possibility that a discharge occurs in the outer bulb and the other arc tube does not light up. When the pressure exceeds 70 kPa, it is difficult to seal the outer bulb. is there.

[Reduction of restart time and realization of instantaneous restart]
The inventors set the goal of reducing the restart time to about half of 4 minutes as the first stage. Furthermore, as the second stage, the goal was to shorten within 1 minute.

  As a first approach, it was studied to shorten the restart time and realize the instantaneous restart by increasing the pulse voltage applied at the time of restart.

  FIG. 2 is a graph for explaining the pulse voltage-restart time characteristic RS-A when the pulse voltage Vp is sequentially increased in the lamp shown in FIG. The output of this lamp is 190 W and is currently used with a pulse voltage of 2.3 kV. The lamp has a withstand voltage value as a product specification. The withstand voltage value is determined by the withstand voltage value of the base, the distance between different potential conductors, and the like. In general illumination lamps having a base as shown in FIG. 1 (that is, lamps other than special uses such as automobile headlamps), the withstand voltage value is generally about 5.0 kV. Accordingly, the restart time t was determined by changing the pulse voltage Vp between 2.3 and 4.5 kV in consideration of a 10% margin.

  From the results of FIG. 2, the following matters were found.

  (1) When the pulse voltage Vp is increased to 3.5 to 4.5 kV, the restart time t decreases to about half.

  (2) The restart time of the pulse voltage of 2.3 kV is about 8 minutes. If this can be reduced to about 4 minutes by any means, the restart time t is within 1 minute as long as the same characteristics are drawn. Can be shortened.

  The restart time of the lamp with one arc tube is 15 minutes or more. The restart time when the two arc tubes are alternately lit is about 8 minutes. The starting time of the lamp in the cold state (room temperature) is several seconds. Accordingly, in the case of two arc tubes, the restart time of the pulse voltage 2.3 kV can be expected to be about 4 minutes if the temperature rise of the arc tube during extinction can be suppressed to less than half the current level.

  Therefore, as a second approach, a means for suppressing the temperature rise of the other arc tube during extinction was examined. As a result, a heat shielding member (also referred to as a “heat diffusion member”) is arranged between one light-emitting tube that is turned on and the other light-emitting tube that is turned off. By disposing a member having good heat diffusion performance as a heat shielding member, heat from one arc tube is diffused by the heat shielding member, and is less transmitted to the other arc tube, or the other light emission Stop concentrating on the tube.

  In addition, since this heat shielding member is arrange | positioned between an arc_tube | light_emitting_tube, it needs to be translucent. For example, transparent quartz glass can be used as the material of such a light-transmitting heat shielding member. However, it is not limited to this.

  FIG. 3 is a graph showing the effect of the translucent heat shielding member. The pulse voltage-restart time characteristic RS-A (indicated by ♦) is the case where there is no translucent heat shielding member described in FIG. 2, and the pulse voltage-restart time characteristic RS-B (indicated by □) is This is a case where an appropriate translucent heat shielding member is disposed.

  In the relationship between the characteristic RS-A and the characteristic RS-B, the shortening of the restart time due to the arrangement of the translucent heat shielding member is indicated by Tt, and the shortening of the restart time by increasing the pulse voltage is indicated by Tv. ing.

  At the pulse voltage of 2.3 kV, the restart time is about 8 minutes in the characteristic RS-A, but the restart is performed in the characteristic RS-B by arranging a translucent heat shielding member between the two arc tubes. The time was shortened to 4 minutes or less. Further, by sequentially increasing the pulse voltage 2.3 kV, the restart time can be shortened within 3 minutes at the pulse voltage 2.5 to 4.5 kV, and further at the pulse voltage 3.0 to 4.5 kV, The restart time could be shortened within 1 minute.

[Ceramic metal halide lamp illumination device according to this embodiment]
FIG. 4A is a diagram for explaining the configuration of the ceramic metal halide lamp 10-1 according to the present embodiment. Compared with the lamp 10 of FIG. 1, a translucent heat shielding member 12 is disposed between the arc tubes 4-1 and 4-2. The relationship between the arc tubes 4-1 and 4-2 and the translucent heat shielding member 12 is as shown in FIG.

(Modification of translucent heat shielding member)
FIG. 5 is a view showing a modification of the translucent heat shielding member 12 used in the ceramic metal halide lamp shown in FIG. The translucent heat shielding member 12 may be an arbitrary member as long as it is translucent and has good heat diffusion characteristics and is disposed between the two arc tubes. If each translucent heat shielding member has a shape surrounding one arc tube, it is more preferable as a heat shield between the arc tubes.

  In the first modification, the translucent heat shielding members 12-1 and 12-2 are cylindrical members surrounding the arc tubes 4-1 and 4-2, respectively. In the modified example 2, the translucent heat shielding members 12-3 and 12-4 surround each arc tube, and each translucent heat shielding member has two test tube shapes having slightly different diameters. The body is formed by combining glass tubes with each other, the body is cylindrical, and both ends are closed (there is a lead wire opening connected to the arc tube).

(Lamp drive circuit)
FIG. 6 is a diagram for explaining a drive circuit for a ceramic metal halide lamp. Power is supplied to the ceramic metal halide lamp 10 from a ballast 16 connected to a commercial AC power supply (100/200 V, 50/60 Hz) 14. The ballast 16 includes a choke coil 17 and an igniter (starting circuit) 18. The arc tubes 4-1 and 4-2 in the lamp are electrically connected in parallel to the power supply side.

  As shown in FIG. 6, in the ceramic metal halide lamp illuminating device, the lamp itself does not have a starting circuit, and one arc tube that is easily lit is turned on by a pulse from the ballast 16. At the time of restart, the pulse voltage Vp from the igniter 18 is changed from Vp = 2.3 kV to Vp = 3.0 to 4.5 kV.

[Others]
As described above, the present invention has been described along the embodiment of the two arc tube lamps, but the present invention is also applicable to three or more arc tube lamps. An appropriate translucent heat shielding member is disposed between the arc tubes, and the pulse voltage is sequentially increased to determine a pulse voltage that can obtain a desired restart time.

  According to such a procedure, a new translucent heat shielding member is obtained, and if the heat shielding performance is improved, the pulse voltage at which a desired restart time is obtained becomes lower than before.

  Further, with respect to a lamp having a plurality of arc tubes of any type, a pulse voltage that can obtain a desired restart time can be determined according to such a procedure.

  Therefore, although the embodiment of the ceramic metal halide lamp according to the present invention has been described, these are examples and do not limit the scope of the present invention. Additions, deletions, changes, improvements, and the like that can be easily made by those skilled in the art with respect to the present embodiment are within the scope of the present invention.

  The technical scope of the present invention is defined by the description of the appended claims.

2: outer sphere, 4,4-1, 4-2: arc tube, 8: mount, 10: ceramic metal halide lamp, 12, 12-1, 12-2, 12-3, 12-4: translucent heat Shielding member, 14: commercial AC power supply, 16: ballast, 17: choke coil, 18: igniter, starting circuit,
Vp: Pulse voltage, RS-A, RS-B: Pulse voltage-restart time characteristics, Tt: Reduced restart time due to arrangement of heat shield member, Tv: Reduced restart time by increasing pulse voltage ,

Claims (4)

In a lighting device comprising a ceramic metal halide lamp and a drive circuit,
The ceramic metal halide lamp has a plurality of arc tubes in one outer sphere, and is a lamp in which only one arc tube that is always lit is lit.
In order to suppress heat transfer from one light-emitting tube to the other light-emitting tube, the light-transmitting heat-shielding member is disposed between the plurality of light-emitting tubes, and the light-transmitting heat-shielding member is provided. The member is a member surrounding each of the luminous tubes, and the body formed by combining two test tube-shaped glass tubes having slightly different diameters is cylindrical, and both ends are formed round. And
The said drive circuit is an illuminating device which applies the pulse voltage of 2.5-4.5 kV to the said lamp | ramp at the time of restart. The lighting device according to claim 1.
The said drive circuit is an illuminating device which applies the pulse voltage of 3.0-4.5 kV to the said lamp in the case of restart. The lighting device according to claim 1 or 2,
The translucent heat shielding member is an illumination device made of quartz glass. In the illuminating device as described in any one of Claims 1-3 ,
The lamp is a lighting device having an output of 190 W.

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