JP2006059826A - Tungsten halogen lamp with reflecting mirror - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tungsten halogen lamp with a reflecting mirror for improving a lighting efficiency and saving energy without increasing costs and deteriorating a service life and vibration resistance. <P>SOLUTION: The tungsten halogen lamp with the reflecting mirror 100 has a reflecting mirror 120 with a concave reflecting face attached to a tungsten halogen lamp 110 provided with an approximately cylindrical light-emitting unit 2 of which the inside is filled with filler gas and a double-wired coil 5 held nearly along a central axis inside the light-emitting part 2 by two lead wires. A shape of the coil 5 is set so as to make a ratio between an outer diameter FD<SB>1</SB>(mm) of a primary coil and a pitch P<SB>2</SB>(mm) of the 2n-th coil become 1.6≤P<SB>2</SB>/FD<SB>1</SB>≤2.5, an arrangement position of the coil 5 in a direction along the center axis A of the reflecting mirror 120 includes a position of a focus F of the mirror 120 and also a center position M of the coil 5 in the center axis A direction is positioned further toward a base 130 side of the mirror 120 than the position of the focus F. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a halogen bulb with a reflector.

In general, halogen bulbs are widely used for general lighting in stores and the like because they have higher lamp efficiency than ordinary incandescent bulbs and can easily control light distribution when combined with a reflector. .
When evaluating such a halogen bulb with a reflector, the illuminance at the central portion of the irradiation surface at a predetermined distance (the illuminance at the intersection of the irradiation surface and the extension line of the central axis (optical axis) of the reflection mirror. The magnitude of “central illuminance” is one standard, and it has been a problem to improve the central illuminance per unit W (hereinafter, in this specification, halogen with a reflector). The size of the central illuminance per bulb (1x / W) is defined as “illumination efficiency”.

If such illumination efficiency can be improved, power consumption for obtaining a predetermined central illuminance can be reduced, which can contribute to energy saving.
And in order to improve illumination efficiency, the following two approaches are conventionally considered.
One is a method of improving the lamp efficiency of the halogen bulb itself, and the second is a method of improving the reflection efficiency by the reflecting mirror.

  As a method for improving the lamp efficiency of the former halogen bulb itself, for example, in Patent Document 1, the bulb shape of the light emitting part of the halogen bulb is changed from a normal cylindrical shape to a spheroid shape, and infrared rays are applied to the outer peripheral surface thereof. A configuration in which a special multilayer interference film (infrared reflective film) that reflects and transmits visible light is disclosed (hereinafter, this configuration is referred to as “spheroid type”).

The light emitted from the coil of the light bulb contains 70% or more of infrared rays, and the infrared rays are reflected to the inside of the light emitting portion by the infrared reflecting film, but the shape of the light emitting portion is a spheroid. Therefore, the reflection direction of the infrared rays is concentrated on the inner coil direction, whereby the coil is further heated and the lamp efficiency is improved.
However, according to such a configuration, there is a problem in that the outer diameter of the light emitting portion is increased because the light emitting portion must have a spheroid shape that bulges outward.

FIG. 17 is a diagram showing a configuration of a halogen bulb 200 with a reflector using the spheroid-type halogen bulb. For convenience of explanation, the reflector and the base are shown in cross section. As shown in the figure, the halogen bulb 200 with a reflector is configured by attaching a base 230 and a reflector 220 to a spheroid halogen bulb 210.
Since the dimensions such as the maximum aperture D0 of the reflecting mirror 220 are determined by the standard of JEL (Japan Light Bulb Industry Association) 115 (for example, Φ50 commercial voltage reflective type rated output 110V / 40W, 65W type, D0 = 53 mm or less), and the shape of the reflecting surface 221 is also specified according to the desired beam angle. As described above, the spheroidal halogen light bulb 210 has a large diameter of the light emitting portion 211, so that the base of the reflecting mirror 220 is formed. The diameter D1 of the opening 223 on the 230 side must be increased. Accordingly, the effective area of the reflecting surface 221 of the reflecting mirror 220 is reduced by about 4% compared to the case where a conventional cylindrical halogen bulb is used, and the lamp efficiency of the halogen bulb 210 itself is increased, but the illumination efficiency is increased. The actual situation is that it does not improve as expected.

On the other hand, since the infrared reflecting film is formed on the outer peripheral surface of the light emitting part, there is a problem that the cost is increased. In addition, an increase in manufacturing cost such as a change in mold due to a change in the design of the reflector is inevitable.
If the reflector is matched to the standard of Φ70 commercial voltage reflection type, the effective reflection area can be increased, so that the reflection efficiency can be improved. However, the size is increased by that amount, and the usage is limited. The increase of unavoidable.

  Therefore, an approach based on a method of improving the reflection efficiency by the reflecting mirror while maintaining the cylindrical bulb shape is desired. Conventionally, the length of the coil in the valve central axis direction (hereinafter referred to as “coil length”) is desired. With a reflector so that it is as close as possible to the point light source, and the coil is almost coaxial with the center axis of the reflector, and the center position of the coil in the longitudinal direction coincides with the focal position of the reflector I was assembling a halogen bulb.

However, in order to obtain a predetermined rated output, a certain length of the coil wire is required. Therefore, in order to actually shorten the coil length, a triple winding type coil or the like is adopted, and a low order coil (triple winding) is used. In the case of a type coil, the coil pitch of the primary coil and the secondary coil) must be reduced and the number of turns of the highest order coil must be reduced.
As a result, the coil length can be shortened to about 6.0 mm and the light emission amount per turn can be increased. This is almost coaxial with the central axis (optical axis) of the reflecting mirror and in the coil length direction. If the center position is located at the focal point of the reflector, the reflection efficiency will surely improve.
JP 2002-151014 A

However, it has been found that the halogen bulb with the coil length shortened has a problem in vibration resistance and has a short life.
That is, in order to reduce the number of turns with a short coil length as described above, the pitch of the lower coil must be made very small, and the coil wire becomes dense and the temperature rise at the time of lighting is remarkable. The coil wire (tungsten) tends to evaporate, and if even a slight vibration is applied, a short circuit may occur between adjacent turns, causing a large current to flow and fusing, which causes a shorter life than the normal life. As a result, the impact resistance also deteriorates.

  The present invention has been made to solve the above-described problems, and can improve lighting efficiency and save energy without incurring an increase in cost or a deterioration in life and vibration resistance. An object of the present invention is to provide a halogen bulb with a reflector.

In order to achieve the above object, a halogen light bulb with a reflector according to the present invention includes a substantially cylindrical light-emitting part in which an enclosed gas is enclosed, and a light axis inside the light-emitting part and substantially coaxial with the central axis of the light-emitting part. A halogen light bulb with a reflecting mirror, which is formed by combining a halogen light bulb having an n-fold wound type (n = 2, 3, 4,...) Coil disposed on a reflecting mirror having a concave reflecting surface. When the outer diameter of the n-order coil of the n-fold coil is FD _n (mm) and the coil pitch of the n-order coil is P _n (mm), 1.6 ≦ P _n / FD _{n −1} ≦ 2.5 and the position of the n-fold coil in the direction along the central axis of the reflector includes the position of the focal point of the reflector, and the n-fold coil The central position in the central axis direction of the reflection is more reflective than the focal position. It is characterized by the positional relationship of the halogen bulb and the reflector is set to be positioned on the opposite side to the front opening of the.

In the n-fold coil, as described above, the ratio P _n / FD _n-1 of the pitch P _n of the n-order coil and the outer diameter FD _n-1 of the (n-1) -order coil is 1.6 ≦ P _n. By forming so as to satisfy the relationship of / FD _n-1 ≦ 2.5, it is possible to obtain a halogen light bulb that is less susceptible to pitch touch and excellent in impact resistance and in which the luminous flux of the arc tube does not decrease.
In addition, the position of the n-fold coil of the halogen bulb in the direction along the center axis of the reflector includes the position of the focal point of the reflector, and the center of the n-wrap coil in the center axis direction By placing the position of the n-type coil on the side opposite to the direction in which the reflecting mirror spreads from the position of the focal point, more n-fold wound coil portions are located within a range that contributes to an improvement in central illuminance. It can be expected to improve the central illuminance.

Here, the coil length of the coil is preferably less than 11 mm.
In addition, it is desirable that the pitch P _n of the n-order coil of the n-fold coil is in the range of 0.46 mm ≦ P _n ≦ 0.74 mm.
Furthermore, it is desirable that the outer diameter FD _n-1 of the (n−1) -order coil of the n-fold coil is in a range of 0.28 mm ≦ FD _n−1 ≦ 0.45 mm.

The outer diameter FD _n of the n-order coil of the n-fold coil is preferably in the range of 1.50 mm ≦ FD _n ≦ 1.76 mm.
The maximum aperture of the reflecting mirror is approximately 50 mm, is substantially coaxial with the central axis of the reflecting mirror, and is based on the focal position of the reflecting mirror from the focal position to the front surface of the reflecting mirror. The n-fold wound coil is disposed substantially over the entire specified range from a position of approximately 0.5 mm in the direction of the opening to a position of approximately 5.5 mm in the direction opposite to the front opening of the reflector from the focal position. The coil length of the n-wound coil and the relative position of the halogen bulb to the reflector are set so that the entire n-wound coil is included in the specific range. It may be characterized by being.

Hereinafter, a halogen light bulb with a reflector according to an embodiment of the present invention will be described with reference to the drawings.
(Overall structure of halogen bulb with reflector)
FIG. 1 is a partially cutaway cross-sectional view showing a configuration of a halogen bulb 100 with a reflecting mirror in the present embodiment. In this embodiment, the halogen lamp 100 with a reflector has a rated output of 110 V / 65 W and a beam angle of 10 °.

As shown in the figure, in the halogen bulb 100 with a reflector, a base 130 is attached to the external lead wires 12 and 13 side of the halogen bulb 110 having the cylindrical light emitting portion 2, and the reflector 120 is installed in the opening 133 of the base 130. The neck portion 124 is inserted and fixed with an adhesive (not shown) such as cement.
In the present embodiment, the coil 5 of the halogen bulb 110 is formed so as to satisfy a predetermined condition, and the central position (hereinafter simply referred to as “coil center”) M in the central axis direction of the coil 5 is reflected. It is characterized in that the relative position of the halogen bulb 110 and the reflecting mirror 120 is set so as to be closer to the base 130 than the focal point F of the mirror 120 by a predetermined amount. Details will be described later.

  The external lead wire 12 of the halogen bulb 110 is connected to one end of a lead wire 134 via a protective current fuse 14 made of an alloy of copper and nickel. The lead wire 134 is drawn to the outside through a through hole 136 provided in a base insulator 137 of the base 130 and connected to the base shell 131. The external lead wire 13 is connected to the metal terminal 132 through the lead wire 135.

As the reflecting mirror 120, a multilayer interference film 121a that transmits infrared rays and reflects visible rays is formed on an inner surface 121 of a concave curved surface such as a paraboloid or an ellipsoid formed on a reflecting mirror body made of hard glass. A known dichroic mirror is used.
The halogen light bulb with the dichroic mirror type reflecting mirror transmits infrared rays backward, so that the front in the irradiation direction does not become so hot, and is suitable for illumination in a store display or the like.

  According to the present embodiment, since the light-emitting portion 2 of the halogen bulb 110 has a cylindrical shape, the outer diameter d is smaller than that of the spheroid-type halogen bulb 210 (see FIG. 17) in the prior art, so that the reflection is performed. The inner diameter D2 of the opening 123 on the small-diameter portion side of the mirror 120 can also be made smaller than D1, and the area of the effective reflection surface is increased accordingly, so that when the aperture is the same, more light flux is reflected forward. Can be made.

In addition, the neck portion 124 extends rearward so that the halogen bulb 110 can be attached closer to the base 130 than in the past, and the lamp arrangement described later is possible.
A front glass 140 is attached to the front opening 125 of the reflecting mirror 120 by caulking the periphery of the front glass 140 with a metal ring 141 around the front opening. The front glass 140 also has a function of a convex lens, and acts to improve the light collection rate, and also serves as a cover for sealing so that dust and the like are not mixed inside. In FIG. 1, in order to avoid complication of the drawing, the hatched lines indicating the cross sections of the front glass 140 and the metal ring 141 are omitted, and the outlines of the outer shapes are indicated by solid lines.
(Configuration of halogen bulb 110)
FIG. 2 is an enlarged view of the halogen bulb 110, and in order to explain the internal structure, the closed portion 1, the light emitting portion 2 and the stem 8 of the bulb 4 are shown in a sectional view.

As shown in the figure, the halogen bulb 110 includes a quartz glass bulb 4 in which a closing portion 1, a cylindrical light emitting portion 2, and a sealing portion 3 are sequentially connected. Inside the light-emitting portion 2, a double-winding coil 5 made of tungsten has a central axis of the coil 5 (a spiral axis of the double-winding coil; the same applies hereinafter) and a cylindrical central axis of the light-emitting portion 2. Arranged in a consistent state.
Both ends of the coil 5 are respectively connected to tungsten lead wires 6 and 7 held on a stem 8 made of quartz glass, and are supported in a stretched state. An intermediate portion of the coil 5 is suspended from an end portion of a tungsten anchor wire 9 held by the stem 8, thereby preventing the coil 5 from being bent.

The other ends of the lead wires 6 and 7 are connected to external lead wires 12 and 13 made of molybdenum via molybdenum foils 10 and 11 sealed in the sealing portion 3.
Inside the light emitting unit 2 is a base gas containing at least one of argon gas, xenon gas, and krypton gas as an enclosed gas. A trace amount of halogenated compound (CH ₂ Br ₂ ) is enclosed. In addition to the main components, argon gas, xenon gas, and krypton gas, nitrogen gas is added to the base gas at around 10 to 20%. As a result, it is possible to prevent arc discharge from occurring between both ends of the coil 5 during steady lighting. In the present embodiment, specifically, a base gas in which 12% of nitrogen gas is added to xenon gas as a main component in the light emitting section 2 is sealed at 0.5 MPa at a normal temperature pressure.

The detailed dimensions of each part of the halogen bulb 110 are as follows.
Total length of valve 4 (La) 39.5 mm
Light emitting part 2 outer diameter (inner diameter) 11 mm (9 mm)
External lead wire 12, 13 wire diameter 0.5mm
Wire diameter of coil 5 0.052mm
Primary coil mandrel (inner diameter) 0.25mm
Primary coil outer diameter (FD ₁ ) 0.35 mm
Primary coil pitch (P ₁ ) 0.09 mm
Secondary coil mandrel (inner diameter) 0.93mm
Secondary coil pitch (P ₂ ) 0.68 mm
Secondary coil length (Lc) 8.0mm
Secondary coil outer diameter (FD ₂ ) 1.63 mm
However, the primary coil pitch (P ₁ ) and the secondary coil pitch (P ₂ ) are shown as values before being attached to the lead wires 6 and 7.
(Optimization of coil position for reflector)
Next, optimization of the position of the coil 5 of the halogen bulb 110 with respect to the reflecting mirror 120 will be described.

In the design of a conventional halogen lamp with a reflector, it was most desirable to arrange the coil 5 so as to be symmetrical with respect to the focal point along the central axis (optical axis) of the reflector 120. To improve the central illuminance, it is ideal to have a point light source at the focal point, and as long as the coil has a physical length, it is best to place it symmetrically with respect to the light source. (This type of coil arrangement is hereinafter referred to as a “focus symmetric arrangement”.)
However, the inventors of the present application have an opening 123 on the base 130 side for mounting the halogen bulb 110, and the focus symmetric arrangement as described above is not necessarily ideal. I was wondering if it was possible, and tried computer simulation under the following conditions.

FIG. 3 is a diagram showing a simulation image when the virtual coil 50 having only one turn is arranged on the optical axis of the reflecting mirror 120. The maximum aperture of the reflecting mirror 120 is 50 mm, and the minimum aperture (neck side opening diameter) is 16 mm. The beam angle is 10 °.
Further, in order to clearly grasp the relationship between the position of the light source and the central illuminance, the virtual coil 50 approximates the secondary winding coil with the primary winding coil and dares to have only one turn. Here, the wire diameter of the virtual coil 50 is 0.4 mm, and the coil outer diameter is set to 2 mm.

4 is a longitudinal sectional view when the reflecting mirror 120 in FIG. 3 is cut along its optical axis, and F indicates the focal point of the reflecting mirror 120. Then, assuming an irradiation surface of 2.25 m ahead, a process of calculating the central illuminance on the irradiation surface at each position by moving the virtual coil 50 in a state where the central axis is always parallel to the central axis A of the reflecting mirror 120. Executed.
The center position of the virtual coil 50 is moved on the x-axis passing through the focal point (the central axis of the reflecting mirror 120) and in the y-axis direction (mirror radial direction) passing through the focal point and perpendicular to the x-axis. .

5 and 6 are graphs showing the results of this simulation.
FIG. 5 is a graph showing a change in illumination surface center illuminance (lx) when the center of the virtual coil 50 is moved on the mirror central axis. In the graph, the origin is a point B (see FIG. 4) where the optical axis A and the opening surface of the reflecting mirror 120 intersect, and the focal point F is located at a distance of approximately 16.5 mm from the point B.

As shown in the figure, the central illuminance rapidly rises from about 0.5 mm before the front opening 125 side (hereinafter simply referred to as “front side”) of the focal reflector 120 and reaches the maximum illuminance at the position of the focal point F. It gradually decreases after reaching the focal point F, and becomes almost zero after about 5.5 mm from the focal point F to the neck side (hereinafter simply referred to as “rear side”).
That is, only the range R of approximately 6 mm from the front 0.5 mm of the focal point to the rear 5.5 mm of the focal point contributes to the improvement of the central illuminance. It has been found that it hardly contributes to the improvement (the range R in the mirror central axis direction of the coil position for contributing to the improvement of the central illuminance is hereinafter referred to as “central illuminance contribution range”).

  Now, specifically considering the case where the coil length Lc is 8 mm, as shown in FIG. 7A, in the conventional focus symmetry type arrangement, 4.5 mm (center of the central illuminance contribution range 6 mm). The coil overlaps only about 75% of the illumination contribution range. On the other hand, from the viewpoint of the coil, only 4.5 / 8 = 0.56, that is, about 56% of the total luminous flux emitted from the coil contributes to the central illuminance.

However, as shown in FIG. 7B, if the coil is shifted further rearward so that 100% of the coil exists in the central illumination contribution range, 6/8 = 0 of the total luminous flux emitted from the coil. .75, that is, 75% contributes to the central illuminance, improving the illumination efficiency.
From the above, it can be seen that the center illuminance is improved by shifting the position of the coil from the conventional focus symmetric arrangement toward the base 130 so that the ratio of the coils within the central illuminance contribution range is as large as possible.

  Incidentally, Table 1 shows the relationship between the coil length and the ratio of the coil within the central illuminance contribution range of 6 mm in the case of the focus symmetric arrangement.

As is apparent from Table 1, in the case of the focus symmetry type arrangement, the shorter the coil length, the shorter the coil length within the central illuminance contribution range. Therefore, even if the coil length is shortened to make the light source a point light source as in the prior art, it does not sufficiently contribute to the improvement of the central illuminance as long as the focus symmetric arrangement is used.
On the other hand, when the coil length is 11 mm, the coil is present in almost 100% of the central illuminance contribution range even in the focus symmetric arrangement. Therefore, it can be said that the illumination efficiency can be improved by shifting the coil to the rear side as compared with the focus symmetrical arrangement as in the present invention when the coil length is less than about 11 mm.

On the other hand, FIG. 6 shows the distance (horizontal axis) from the focal point of the center of the virtual coil 50 and the central illuminance of the irradiated surface when the virtual coil 50 is moved in the mirror radial direction (y-axis direction in FIG. 4) at the focal point. It is a graph which shows the relationship.
As shown in the figure, the central illuminance is greatest when the virtual coil 50 is substantially coaxial with the central axis A, and the central illuminance decreases as the distance from the virtual coil 50 increases. From the result of this simulation, it is understood that it is desirable that the light emission position is closer to the central axis A. In a normal multi-winding coil, the position of the coil of each turn of the highest order coil is as close as possible to the central axis. That is, it is suggested that the outer diameter of the highest order coil is as small as possible when improving the central illuminance.
(Optimization of coil shape)
From the results of the above discussion, it can be seen that if the coil length is shortened and the highest coil outer diameter is reduced so that the coil is included in the central illumination contribution range, the illumination efficiency can be improved.

However, as described in the prior art, simply shortening the coil length deteriorates the impact resistance and shortens the lamp life. Next, an experiment was conducted on the optimization of the coil shape.
Table 2 shows the standard of the lamp characteristic value in the above-mentioned JEL. When evaluating the test lamp in the following experiment, it is one standard that the standard value (especially the luminous flux of the arc tube and the lifetime) is not less than the standard value. Become.

First, test lamps were prepared using double-wound coils of various shapes for halogen bulbs with rated outputs of 110 V / 40 W and 110 V / 65 W.
Here, for the n-fold coil (n = 2, 3, 4,...), The outer diameter of the m-order coil (m = 1, 2, 3,..., N) is set to FD _m (mm When the coil pitch is defined as P _m (mm), in the case of a double-winding type coil, the outer diameter of the secondary coil is FD ₂ , the coil pitch is P ₂ , and the primary as shown in FIG. the outer diameter of the coil can be expressed as FD _1.

The life of the coil is considered to depend in particular on the size of the gap between adjacent turns of the highest-order coil, and its size is a correlation between the coil pitch P ₂ of the secondary coil and the coil outer diameter FD ₁ of the primary coil. Since it depends on the relationship, I first examined this relationship.
(Experiment 1)
For a halogen bulb with a rated output of 40 W, create a plurality of test lamps in which the primary coil outer diameter FD ₁ is fixed to 0.35 mm and the secondary coil pitch P ₂ is changed from 0.4 mm to 1.05 mm. An experiment was conducted in which these were lit continuously and their lifetime was measured.

  The following Table 3 shows the experimental results.

In the table, in order to show the correlation between the coil pitch P ₂ of the secondary coil and the coil outer diameter FD ₁ of the primary coil, the value of P ₂ / FD ₁ is calculated to correspond to the value of the coil pitch P _2. Is written.
FIG. 9 is a graph in the case where the value of P ₂ / FD ₁ is plotted on the horizontal axis, the life time at that time is plotted on the vertical axis, and the experimental results in Table 3 are plotted and connected by an approximate curve. As shown in the graph, when the value of P ₂ / FD ₁ is less than 1.6, the service life time is drastically reduced, and significantly falls below the standard value of 3000 hours in Table 2.

With such a primary coil diameter FD ₁ is larger than the secondary coil pitch P _2, smaller than necessary gap between turns adjacent to each other in the secondary coil.
Usually, as the lighting time elapses, a particle lump of tungsten, which is a coil wire material, is generated, and the pitch interval is disturbed and a phenomenon in which turns of adjacent coils come into contact with each other (pitch touch) may occur. However, as described above, when the value of P ₂ / FD ₁ is less than 1.6, it is understood that the occurrence of pitch touch becomes significant.

When pitch touch occurs in this way, the lamp current increases, the coil temperature rises, the evaporation of tungsten is accelerated, and the life is shortened.
Next, when a similar experiment was performed on a halogen bulb with a power consumption of 65 W, the results shown in Table 4 below were obtained.

FIG. 11 is a graph showing the experimental results in Table 4 with the value of P ₂ / FD ₁ as the horizontal axis and the lifetime at that time as the vertical axis, as in FIG. 9. Even in this case, when the value of P ₂ / FD ₁ is less than about 1.6, the lifetime is drastically decreased, and the result is significantly less than the standard value of 3000 hours in Table 2.
Therefore, it can be said that the value of P ₂ / FD ₁ is desirably 1.6 or more in order to obtain a lifetime longer than the standard value.

On the other hand, this experiment revealed that there is a certain relationship between P ₂ / FD ₁ and the arc tube luminous flux.
FIG. 10 is a graph showing the relationship between P ₂ / FD ₁ and arc tube luminous flux among the experimental results of the 40 W halogen bulb shown in Table 3. The horizontal axis represents the value of P ₂ / FD ₁ in the vertical direction. The axis indicates the value of the arc tube luminous flux (lm).

As shown in the graph, when P ₂ / FD ₁ exceeds approximately 2.5, the luminous flux of the arc tube rapidly decreases, resulting in a decrease below 550 lm. As shown in Table 2, since the luminous flux of the arc tube needs to be 550 lm or more as a standard of a 40 W halogen bulb, the value of P ₂ / FD ₁ is desirably 2.5 or less.
FIG. 12 is a graph showing the relationship between P ₂ / FD ₁ and arc tube luminous flux among the experimental results of the 65 W halogen bulb shown in Table 4. Even in this case, P ₂ / FD _{1 is} almost equal. If it exceeds 2.5, the luminous flux of the arc tube rapidly decreases, resulting in a result that is lower than 1100 lm, which is the standard for 65 W halogen bulbs.

Therefore, even in the case of a 65 W bulb, it can be said that the value of P ₂ / FD ₁ is desirably 2.5 or less in order to maintain a luminous flux of the arc tube of a certain value or more.
The reason why the luminous flux of the arc tube deteriorates when the value of P ₂ / FD ₁ exceeds a certain value is considered as follows.
That is, as P ₂ / FD ₁ increases, the coil pitch P ₂ increases as compared with the coil diameter FD ₁ and the gap between adjacent turns also increases. For this reason, a loss increases when the heat radiated from one turn heats the adjacent turn. As a result, the coil temperature is lowered, and the luminous flux is reduced.

If the luminous flux between the lights decreases, the center illuminance cannot be improved no matter how much the coil position is adjusted. From this viewpoint, it can be said that P ₂ / FD ₁ is preferably 2.5 or less.
(Consideration from the viewpoint of impact resistance)
Then, in each silver bulb 40W and 65W, the secondary coil pitch _{P 2} and 0.7 mm, the primary coil outer diameter FD _1, by changing to 0.2 to 0.6 mm, the shock load experiment went.

  This experiment was performed by the lighting drop impact test method in this embodiment. In this test method, a halogen bulb is maintained in a certain direction, is lit at a rated voltage, and a 40G impact (an impact comparable to that when a person bumps his head against a lamp fixture) is applied at the time of a collision with the floor surface. This is a test method in which the halogen bulb is dropped from such a height, and it is confirmed how many times the halogen bulb has been turned off.

  Table 5 below shows the results of an impact load experiment on a 40 W halogen bulb.

In the table, the number of impact loads indicates how many times the halogen bulb has been lit, and the higher the number, the higher the impact resistance.
FIG. 13 is a graph of this table, in which the horizontal axis indicates the value of P ₂ / FD ₁ and the vertical axis indicates the number of impact loads. As shown in the figure, when the value of P ₂ / FD ₁ is less than 1.6, the impact resistance is rapidly deteriorated.

  Similarly, Table 6 shows the result of an impact load experiment in a 65 W halogen bulb, and FIG. 14 is a graph of this.

As can be seen from FIG. 14, even in the case of a 65 W bulb, when the value of P ₂ / FD ₁ is less than 1.6, the impact resistance is abruptly deteriorated.
Thus, when the coil pitch P ₂ of the secondary coil is constant at 0.7 mm and the value of P ₂ / FD ₁ decreases, the value of FD ₁ increases, so the radius of curvature of each turn of the coil increases. As a result, the rigidity is reduced, and when an impact is applied, the amplitude of each turn in the direction of the central axis of the coil is increased due to the vibration generated at that time, and the contact becomes easy. Once contacted, a short circuit occurs, the lamp current increases, the coil is likely to evaporate due to heat generation, and the coil is considered to melt.

Similar results can be obtained even when the coil pitch P ₂ is reduced, and the impact resistance value depends on the relative ratio P ₂ / FD ₁ between P ₂ and FD ₁ .
From the above experiments, the coil shape for excellent impact resistance and long life and for preventing the luminous flux of the arc tube from deteriorating is the ratio P ₂ / secondary coil pitch P ₂ and primary coil outer diameter FD _1. It can be said that FD ₁ is 1.6 or more and 2.5 or less.

(Comparative experiment)
A test lamp was prepared using the following three types of double-wound type coils, and a comparative experiment was performed in which the central luminous intensity was measured while moving each test lamp in the direction of the central axis of the reflecting mirror 120. If the distance from the light source to the irradiation surface is r, the relationship between the luminous intensity I (cd) and the illuminance E (lx) is E = I / (r ² ), and the central illuminance is directly proportional to the central luminous intensity. Here, the central luminous intensity is measured for convenience.

The invention product and the conventional product B were of the 65 W specification, and the conventional product A was of the 75 W specification. However, in order to clarify the difference in central luminous intensity that depends only on the coil shape, the applied voltage is adjusted so that the total luminous flux of each test lamp becomes equal.
FIG. 15 is a graph showing the results of this experiment, and the horizontal axis indicates the percentage of the coil within the central illuminance contribution range in%. The vertical axis indicates the magnitude of the central luminous intensity.

As described above, the central luminous intensity increases as the ratio of the coils in the central illuminance contribution range increases. However, it can be considered that the variation in the central luminous intensity of the conventional product B is large because the coil pitch is large and the central luminous intensity is greatly influenced by which part of the coil is located at the focal position.
In addition, the conventional product B has a center light intensity of about 10% even when the coil length is as short as 6.5 mm, but the central luminous intensity does not reach that of the present invention, and the coil exists in the entire central illumination contribution range. The number of inventions is higher. This is because the secondary coil diameter FD ₂ of conventional product B is large, the light emitting positions are more remote from the center axis of the reflector, central luminous intensity because this is considered to be because have decreased (Fig. 6 (See simulation results for

In addition, the conventional product A has the lowest central luminous intensity because the coil length is as long as 8.5 mm, and even if it is 100% in the central illuminance contribution range, it is 6 / This is considered to be because only 8.5 = 70.6% of the light flux contributes to the improvement of the central illuminance.
From this experiment, it can be seen that in order to improve the central luminous intensity (illuminance) as much as possible, it is desirable to increase the number of turns of the secondary coil as much as possible to reduce the coil pitch.

FIG. 16 is a graph showing changes in central luminous intensity when each test lamp is moved along the central axis of the reflecting mirror 120 in the halogen light bulb 100 with a reflecting mirror.
In the figure, the horizontal axis indicates the position on the central axis of the reflecting mirror 120, and the vertical axis indicates the magnitude of the central luminous intensity on the irradiation surface.
As can be readily seen from the graph, the central luminous intensity fluctuates most of the largest conventional B coil pitch P ₂ and the coil outer diameter FD _2. Thus, it is thought that a thing with a big coil pitch and a coil diameter changes a central luminous intensity largely by which position of the said coil comes near a focus.

If the variation of the central luminous intensity due to such a small change in position is large, if the position of the halogen bulb 110 is slightly deviated from the design position when assembling the halogen bulb 100 with a reflector, the central luminous intensity will vary, which is not desirable.
This result also with increasing the number of turns the secondary coil to reduce the pitch of the secondary coil, it would be desirable to reduce the secondary coil diameter FD _2.
(Summary)
The above experimental results are summarized as follows.
(1) Coil position The coil is not placed in a focus-contrast type, but includes as many coils as possible in the central illuminance contribution range that includes the focal point and is slightly closer to the small-diameter portion (near the base) of the reflector. It is desirable to arrange.

This central illuminance contribution range is a range of approximately 6 mm along the central axis of the reflecting mirror with a beam angle of 10 ° and a maximum aperture of 50 mm, and about 0.5 mm across the focal point is on the front opening side ( (Front glass side), about 5.5 mm exists on the small diameter part side (base side).
When the coil length is less than 11 mm, if the position of the coil in the direction of the central axis includes the focal position and the position of the coil center is at least on the small diameter side from the focal position, the conventional focus symmetric arrangement is adopted. Compared to this, the central illuminance can be improved.

Even if the maximum aperture and beam angle of the reflecting mirror were slightly different, the same results as described above were obtained.
(2) Coil Shape Regarding the double-winding type coil, the ratio P ₂ / FD ₁ between the primary coil outer diameter FD ₁ and the secondary coil pitch P ₂ is 1.6 or more and less than 2.5 (hereinafter, By setting this condition as “optimum coil condition”), good results can be obtained in all aspects of life time, impact resistance and arc tube luminous flux.

Also within the optimum coil conditions are satisfied, by increasing the number of turns of the secondary coil to reduce the secondary coil pitch P _2, it is possible to increase the luminous tube light flux, in the case of obtaining the same center illuminance In addition to energy saving, the light emission distribution in the central axis direction of the coil is uniform, and even when there is a slight error in the mounting position of the halogen bulb 110 when combined with a reflector, there is almost no variation in central illuminance. As a result, it is not necessary to have a high level of assembly accuracy in order to make the illumination efficiency of the product uniform, and it is possible to improve productivity and reduce costs.

If to further reduce the outer diameter FD ₂ of the secondary coil, even contributing to the improvement of the central illuminance.
The wire diameter of the coil wire is determined by the JEL standard, and the range of the outer diameter FD ₁ of the primary coil that can be manufactured is almost specified, and 0.28 mm ≦ FD ₁ ≦ 0.45 mm. . Specifically, this range is determined in consideration of the workability of the lead wire and the like.

That is, since the coil 5 is attached by extrapolating the end of the primary coil to the tip of the lead wires 6 and 7 (see FIG. 2), the inner diameter of the primary coil is the lead wire 6. , 7 depending on the wire diameter. The wire diameter of the coil 5 so that definite in the standard as described above, if the inner diameter of the primary coil is determined, determined naturally also an outside diameter FD _1. Conversely, once the primary coil outer diameter FD _1, so that also determined wire diameter of the tungsten rod used to lead.

On the other hand, although the lead wires 6 and 7 are typically tungsten rod is used, this tungsten rod is poor in workability and empirically primary coil outer diameter FD ₁ is less than 0.28 mm, for use as a lead wire tungsten rod becomes too thin easily broken during processing, it leads the opposition to the primary coil outside diameter FD ₁ exceeds 0.45 mm (tungsten rod) even thicker, excessive force for bending it It is necessary to add it, and productivity deteriorates. Therefore, from the viewpoint of workability and productivity, the range of the primary coil outer diameter FD ₁ is preferably 0.28 mm ≦ FD ₁ ≦ 0.45 mm.

Thus, when the range of the primary coil outer diameter FD ₁ is determined, the range of the primary coil pitch P ₂ can also be obtained within the range satisfying the optimum coil condition, and 0.46 mm ≦ P ₂ ≦ 0.74 mm. Become.
Further, as described with reference to FIGS. 6 and 15, it is desirable that the outer diameter FD _{2 of the} secondary coil is as small as possible in order to improve the central illuminance and make the light emission amount distribution uniform. However, the smaller the secondary coil outside diameter FD _2, the smaller the curvature of each turn, the pitch of the primary coil in the radially inner side of the secondary coil pitch touch is likely to occur becomes smaller, the 1 to avoid pitch touch of the primary coil in the range of the next coil outer diameter FD _1, the outer diameter FD ₂ of the secondary coil which can be formed is desirably in the order of 1.50mm at a minimum. Further, considering the vibration resistance, the outer diameter FD ₂ of the secondary coil towards is 1.76mm or less even maximum desirable.

On the other hand, from the viewpoint of contributing as much light flux emitted from the coil as possible to improve the central illuminance, it is impossible to design the coil length as short as possible so that the entire length of the coil is included in the central illuminance contribution range. Even in such a case, it is desirable that as much of the coil as possible be in the central illumination contribution range.
The length of the coil wire in accordance with the rated output is substantially determined, also assume that the application of the optimal coil condition between the primary coil pitch P ₁ and the coil wire FD _0, further FD ₂ Is the maximum value that can be taken, and the shortest coil length is estimated to be about 6.0 mm for a halogen bulb of 110V / 40W.
However, the wire diameter FD ₀ of the coil wire was set to 0.038 mm, the total length of the coil wire was set to 411 mm, and P ₁ / FD ₀ and P ₂ / FD ₁ were both calculated as a minimum of 1.6.

Similarly, the shortest coil length for a 110V / 65W halogen bulb is estimated to be approximately 6.8 mm.
However, the wire diameter FD ₀ of the coil wire was set to 0.052 mm, the total length of the coil wire was set to 451 mm, and P ₁ / FD ₀ and P ₂ / FD ₁ were both calculated as a minimum of 1.6.
In the above-described embodiment, the double-winding type coil has been described. However, the optimum coil condition can be said to be substantially the same for a multi-winding type coil having three or more turns.

That is, generally speaking, regarding the n-fold coil (n = 2, 3, 4,...), If the relationship of 1.6 ≦ P _n / FD _n−1 ≦ 2.5 is established. Good.
In this case, however, it is desirable that the optimum coil condition be satisfied for lower order ((n-1) th, (n-2) th,..., Secondary) coils. Since the low-order coil is bent in a spiral shape, the coil pitch on the outer side is larger than that on the inner side. Considering that the optimum coil condition is mainly to prevent pitch touch, it is considered that the coil pitch in the optimum coil condition is preferably the inner coil pitch.

Further, it is desirable that the ranges of P _n , FD _n , and FD _n−1 are also in the same ranges as the ranges of P ₂ , FD ₂ , and FD ₁ described above, respectively.

  INDUSTRIAL APPLICABILITY The present invention can be widely used as a halogen bulb with a reflector having excellent impact resistance, a long life, and high central illuminance.

It is a partially cutaway sectional view of a halogen light bulb with a reflector according to an embodiment of the present invention. It is an expanded sectional view of the halogen bulb used for the halogen bulb with a reflector of FIG. It is a perspective view of the reflective mirror and virtual coil for demonstrating the precondition of simulation which calculates | requires the optimal position of a coil. It is a figure for demonstrating the movement range of a virtual coil in the simulation which calculates | requires the optimal position of a coil. It is a graph which shows the change of irradiation surface center illumination intensity when a virtual coil is moved on a mirror central axis. It is a graph which shows the change of illumination surface center illumination intensity when a virtual coil is moved to a mirror radial direction (direction orthogonal to a mirror central axis) in the position of the focus of a reflective mirror. It is a figure which shows the positional relationship of the focus and coil of a reflective mirror in this invention compared with the case of the conventional focus symmetry type | mold arrangement | positioning. It is a figure for demonstrating the symbol of the dimension of each part of a double wound type coil. For 40W type silver bulb is a graph showing the relationship between the secondary coil pitch _{P 2} between the primary coil outer diameter PD ₁ ratio _P 2 / FD ₁ and the lamp lifetime in the secondary winding type coil. For 40W type silver bulb is a graph showing the relationship between the secondary coil pitch P ₂ ratio P _{2 /} FD ₁ of the primary coil outer diameter PD ₁ and the light emitting tube light flux in the secondary winding type coil. For 65W type silver bulb is a graph showing the relationship between the secondary coil pitch _{P 2} between the primary coil outer diameter PD ₁ ratio _P 2 / FD ₁ and the lamp lifetime in the secondary winding type coil. For 65W type silver bulb is a graph showing the relationship between the secondary coil pitch P ₂ ratio P _{2 /} FD ₁ of the primary coil outer diameter PD ₁ and the light emitting tube light flux in the secondary winding type coil. The relationship between the ratio P ₂ / FD _{1 of the} secondary coil pitch P ₂ and the primary coil outer diameter PD _{1 in} the secondary winding coil and the number of impact loads until the lamp is turned off is shown for the 40 W type halogen bulb. It is a graph. The relationship between the ratio P ₂ / FD _{1 of the} secondary coil pitch P ₂ and the primary coil outer diameter PD _{1 in} the secondary winding coil and the number of impact loads until the lamp is turned off is shown for the 65 W type halogen bulb. It is a graph. It is a figure which compares and shows the relationship between the ratio which a coil exists in a center illumination intensity contribution range, and center luminous intensity about this invention product and two conventional products. It is a figure which compares and shows the change of a central luminous intensity when the position of a coil is moved along a reflector central axis about this invention product and two conventional products. It is a figure which shows the structure of the halogen bulb | ball with a reflecting mirror using the conventional spheroid type | mold halogen bulb.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Blocking part 2,211 Light-emitting part 3 Sealing part 4 Bulb 5 Coils 6, 7 Lead wire 8 Stem 9 Anchor wire 10, 11 Molybdenum foil 12, 13 External lead wire 100, 200 Halogen bulb 110, 210 with reflector 120, 220 Reflector 124 Neck portion 125 Front opening 130, 230 Base 140 Front glass

Claims (6)

A substantially cylindrical light-emitting portion in which an enclosed gas is sealed, and an n-fold wound type (n = 2, 3, 4, 4) disposed substantially coaxially with the central axis of the light-emitting portion inside the light-emitting portion. ...) A halogen light bulb with a reflector, in which a halogen light bulb having a coil is combined with a reflector having a concave reflecting surface,
When the outer diameter of the n-order coil of the n-fold coil is FD _n (mm) and the coil pitch of the n-order coil is P _n (mm), 1.6 ≦ P _n / FD _n−1 ≦ 2 .5, and
The position of the n-fold wound coil in the direction along the central axis of the reflector includes the position of the focal point of the reflector, and the center position of the n-fold coil in the central axis direction is the focus. The halogen bulb with a reflector is characterized in that the positional relationship between the halogen bulb and the reflector is set so as to be located on the opposite side of the front opening of the reflector from the position.   The halogen light bulb with a reflector according to claim 1, wherein the coil has a coil length of less than 11 mm. The pitch P _n of the n-order coil of the n-fold coil is:
3. The halogen light bulb with a reflector according to claim 1, wherein 0.46 mm ≦ P _n ≦ 0.74 mm. 4. The outer diameter FD _n−1 of the (n−1) -order coil of the n-fold coil is in a range of 0.28 mm ≦ FD _n−1 ≦ 0.45 mm. 5. A halogen bulb with a reflector according to any one of the above. The outer diameter FD _n of the n-order coil of the n-fold coil is:
The halogen light bulb with a reflector according to any one of claims 1 to 4, wherein 1.50 mm ≤ FD _n ≤ 1.76 mm. The maximum aperture of the reflecting mirror is approximately 50 mm, is substantially coaxial with the central axis of the reflecting mirror, and is based on the position of the focal point of the reflecting mirror from the focal position to the front opening of the reflecting mirror. At least about the n-wound coil in a specific range from a position of about 0.5 mm in the direction of approximately 0.5 mm to a position of approximately 5.5 mm in the direction opposite to the front opening of the reflector from the focal position. The coil length of the n-wound coil and the relative position of the halogen bulb to the reflector are set so that there is a part or all of the n-wound coil is included in the specific range. A halogen bulb with a reflector according to claim 1.

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