JPH0434260B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to metal halide lamps.

Conventional structure and its problems Metal halide lamps are becoming popular in fields such as general lighting as a white light source with high efficiency and high color rendering properties.
ScI ₃ -NaI system, DyI ₃ -TlI-NaI system, etc. are used. Among these metal halides
NaI is included in most additive systems because it has high visible light emission efficiency and contributes to arc stabilization. However, due to the well-known photoelectric effect, NaI
During long-term operation, Na passes through the quartz of the arc tube and precipitates inside the outer bulb, and the iodine remaining inside the arc tube has a negative effect on lamp characteristics, so various countermeasures have been adopted. As one effective means, a mounting structure is known in which the current supply conductor passing on the side of the arc tube is thinned and placed as far away from the arc tube as possible. The disadvantage of adopting such a configuration is that the size (width) of the components of the assembly mount, such as the thin elastic wire that is the current supply conductor and the arc tube, is larger than the diameter of the neck of the outer tube. When inserting into the outer tube, it is necessary to bend the thin wire while inserting it, and at this time, as the thin wire passes through the inner surface of the outer tube while sliding, a phosphor film or a diffusion film is coated on the inner surface of the outer tube. In some cases, parts of this coating may be peeled off, especially if they are relatively weakly adhered by electrostatic coating methods. If part of the phosphor film or diffuser film is peeled off, it will result in linear film scratches, which will be unsightly and will greatly reduce the product value.Furthermore, powder from the peeled off film will adhere to the mount component, causing damage to the bimetallic film. There is also the possibility that problems such as deterioration of the conductivity of components such as switch contacts may occur.

Purpose of the Invention The present invention has been made based on the above circumstances, and is applicable to cases where the phosphor film or diffusion film coated on the inner surface of the outer tube is formed by an electrostatic coating method or the like. Another object of the present invention is to provide a metal halide lamp that does not cause membrane scratches, is free from unsightly appearance, has commercial value, and has improved quality reliability.

Structure of the Invention The metal halide lamp of the present invention passes through the side of an arc tube held inside an outer bulb which has a cap at its end and has a phosphor film or a diffusion film formed on its inner surface. The conductor for supplying power to the arc tube is composed of a thin elastic wire, and the maximum angle of inclination between the tangent of the thin wire located from the center of the arc tube toward the base and the lamp axis is θ (degrees). , when the inner diameter of the straight tube at the neck portion of the outer tube is D (mm), and the distance from the innermost end of the straight tube at the neck portion to the normal end of the phosphor film or the diffusion film is l (mm), The curve approximately approximates a curve with a radius of curvature R (mm) drawn centered on a point on a line perpendicular to the lamp axis at the innermost end of the straight pipe at the neck portion and at a distance of D/2+R from the lamp axis. The normal end of the phosphor film or the diffusion film is located at a portion where the inner diameter of the outer tube gradually increases from the inner diameter of the straight tube at the neck portion so as to satisfy the relationship l≧Rsinθ, and This is designed to prevent membrane damage without impairing the original properties obtained by using a body membrane or a diffusion membrane.

Description of examples Hereinafter, the present invention will be explained using the drawings.

As shown in FIG. 1, the neck portion 1a of the outer tube 1 is shaped like a straight tube, and the inner diameter of the outer tube 1 gradually increases from the innermost end of the straight tube to the neck portion 1a of the outer tube 1.
A curved portion 1b is formed continuously. The curve of the curved part 1b is on a line perpendicular to the lamp axis at the innermost end of the straight pipe, and at a distance of D/2+R from the lamp axis, assuming that the inner diameter of the straight pipe of the neck part 1a is D (mm). Radius of curvature R (mm) drawn around point P at
It almost approximates the curve of . On the other hand, when inserting the mount into the outer tube 1, the elastic thin wire 2
As shown in the figure, from the center of the arc tube 3 to the cap side,
That is, the portion located on the neck side contacts the inner surface of the curved portion 1b of the outer tube 1. As shown in Figure 1,
When the maximum inclination angle of the tangent to the thin line 2 with the lamp axis Y-Y is θ (degrees), a straight line A- that touches the inner surface of the outer tube 1 at a point C at an angle θ with respect to the lamp axis Y-Y.
If you draw B, point C corresponds to the point where the thin wire 2 finally touches the inner surface of the outer tube 1 when inserting the mount into the outer tube 1. The portion 1a side comes into contact with the inner surface of the outer tube 1. Therefore, point C becomes the deepest point at which the coating is peeled off. By the way, if the regular end of the phosphor film or diffusion film is placed deeper than point C, no film damage will occur. However, the deeper the normal end is placed, the more problems arise in terms of manufacturing and light distribution. In other words, as a manufacturing problem, when applying a coating using electrostatic coating methods, it is difficult to provide a regulated end on a curved part that has a larger diameter than the straight pipe at the neck, so After that, the coating on the curved part is removed using a rotating rubber plate, etc., and the adjustment is carried out, but in this case,
The larger the diameter is than the inner diameter of the straight pipe, the longer it takes to adjust, and there is a risk that the finished end of the straight pipe will not be as beautiful. Another problem when the standard end is set further back is that the light distribution curve of the lamp becomes uneven, making it difficult to control the light distribution of the fixture.

Under these circumstances, it is desirable to set the minimum standard distance within a range that does not cause film damage. The present invention has been made in view of the above, and is made by passing through the side of an arc tube held inside an outer tube having a cap at the end and a phosphor film or a diffusion film formed on the inner surface. The conductor for supplying power is made of a thin elastic wire, and the maximum angle of inclination between the tangent of the thin wire located from the center of the arc tube to the cap and the lamp axis is θ (degrees). When the inner diameter of the straight tube at the neck of the outer tube is D (mm), and the distance from the innermost end of the straight tube section to the normal end of the phosphor film or diffusion film is l (mm), the inner diameter of the straight tube section is The inner diameter of the outer tube is approximately approximated to a curve with a radius of curvature R (mm) drawn around a point P located at a distance of D/2+R from the lamp axis on a line perpendicular to the lamp axis at the rear end. In the part that gradually increases from the inner diameter, l≧
The film normal end is positioned so as to satisfy the relationship Rsinθ.

Next, one embodiment of the present invention will be described using the drawings.

FIGS. 3 and 4 show a front view and a side view, respectively, of a metal halide lamp with a rating of 400 W, which is an embodiment of the present invention. In these figures, the arc tube 3 is made of quartz with a distance between electrodes of 42 mm and an outer diameter of 22.5 mm, and is filled with NaI, ScI ₃ , mercury, and argon gas.
It is provided in the outer tube 1 by stem frames 7 and 8 along with a resistor 5, a bimetal switch 6, and the like. The maximum diameter of the outer tube 1 is 120 mm, the straight tube inner diameter of the neck portion 1a is 48.0 mm, and a phosphor film 9 made of YVO ₄ :Eu ⁺³ is coated on the inner surface of the outer tube by an electrostatic coating method. has been done. The radius of curvature R of the curved portion 1b in which the inner diameter of the straight pipe of the neck portion 1a gradually increases is 40 mm, and the angle θ of the thin wire 2 is 24°. Therefore
Rsinθ=16.3mm. The distance l from the innermost end of the straight pipe of the neck portion 1a to the regular end of the phosphor film 9 is 18.0 mm.
It is. When a lamp with such a configuration was prototyped, there were no film scratches or irregularities in the light distribution curve. There was also no electrical disconnection at the bimetal switch contacts.

Effects of the Invention As explained above, the present invention eliminates the occurrence of scratches on the phosphor film and diffusion film adhered to the inner surface of the outer tube, eliminates the unsightly appearance, has high commercial value, and provides light distribution. The characteristics are also the same as those of conventional products, and it is possible to provide a metal halide lamp with stable quality that does not deteriorate the conductivity of components such as bimetal switch contacts.

[Brief explanation of drawings]

Fig. 1 is a diagram for explaining the principle of the present invention, Fig. 2 is a diagram showing a state in the middle of inserting the mount into the outer tube, and Fig. 3 is a part of a metal halide lamp that is an embodiment of the present invention. The cutaway front view and FIG. 4 are similarly partially cutaway side views. 1...Outer tube, 2...Thin wire, 3...Earth tube, 9...
...phosphor film, 10...cap.

Claims (1)

[Scope of Claims] 1. The light passes through the side of the arc tube held inside the outer tube, which has a cap at the end and a phosphor film or a diffusion film formed on the inner surface. The conductor for supplying electric power is composed of a thin elastic wire, and the maximum angle of inclination between the tangent of the thin wire located from the center of the arc tube toward the base and the lamp axis is θ.
(degrees), the inner diameter of the straight pipe at the neck of the outer pipe is D (mm),
When the distance from the innermost end of the straight tube at the neck portion to the normal end of the phosphor film or diffusion film is l (mm),
Approximately approximates a curve with a radius of curvature R (mm) drawn around a point on a line perpendicular to the lamp axis at a distance of D/2+R from the lamp axis at the innermost end of the straight pipe at the neck portion. The normal end of the phosphor film or diffusion film is located at a portion where the inner diameter of the outer tube gradually increases from the inner diameter of the straight tube at the neck portion so as to satisfy the relationship l≧Rsinθ. metal halide lamp.