JP2005222741A - Discharge bulb - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve a problem where erroneous discharge is generated between lead wires. <P>SOLUTION: Three lead wires such as a common lead wire 82, a sub-lead wire 83 and a main lead wire 84 are wired in a form separated from one another. The common lead wire 82 is particularly significantly separated from the sub-lead wire 83. Thereby, this discharge bulb B1 related to this embodiment can extremely reduce the case where erroneous discharge is generated among the three lead wires, in particular, between the common lead wire 82 and the sub-lead wire 83 as compared with a conventional discharge bulb B where the common lead wire 82 is adjacent to the sub-leak wire 83. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a discharge bulb used as a light source such as a headlamp for an automobile, for example, and relates to a discharge bulb capable of generating a plurality of discharge arcs in a discharge space, a so-called double arc discharge bulb. Is.

  Conventionally, this type of double arc discharge bulb is known (for example, Patent Document 1). Hereinafter, a conventional discharge bulb will be described with reference to FIGS. A conventional discharge bulb B generally has a glass tube 1, three electrodes, for example, a common electrode 2, a sub electrode 3, a main electrode 4, and three lead wires, for example, a common lead wire 82 and the sub lead wire 83. The main lead wire 84 and the insulating base 9 are provided.

  The glass tube 1 includes a light emitting portion 5 having a substantially spheroidal shape at the center, and three pinch seal portions 62, 63, 64 provided integrally at substantially the lower portion and both ends of the light emitting portion 5. Have A single discharge space 7 is formed in the light emitting portion 5. The discharge space 7 is filled with an additive (filler) such as a metal halide, a rare gas, or mercury. The glass tube 1 is fixed to the base 9.

  The three electrodes 2, 3, and 4 are made of, for example, tungsten round bars (wires). The discharge ends 20, 30, 40 at one end of the three electrodes 2, 3, 4 have substantially the same size, protrude into the discharge space 7, and face each other with a gap. Further, the portions 21, 31, 41 of the three electrodes 2, 3, 4 are respectively embedded in the pinch seal portions 62, 63, 64 of the glass tube 1 and are kept airtight. Further, the other end portions 22, 32, 42 of the three electrodes 2, 3, 4 are drawn out from the pinch seal portions 62, 63, 64 of the glass tube 1, respectively.

  A common lead wire 82 is connected to the other end 22 of the common electrode 2. A sub lead wire 83 is connected to the other end 32 of the sub electrode 3. Furthermore, the other end 42 of the main electrode 4 is used as a main lead wire 84. The three lead wires 82, 83 and 84 are connected to a terminal (not shown) of the base 9.

  In this way, the discharge bulb B is configured. The base 9 is detachably attached to a reflector such as a headlamp, a connector is connected to the terminal, and the discharge bulb B and the power source are connected via a ballast.

  A voltage is applied to the common electrode 2 and the sub electrode 3 through the common lead wire 82 and the sub lead wire 83. Then, a sub discharge arc (not shown) is generated between the discharge end portion 20 of the common electrode 2 and the discharge end portion 30 of the sub electrode 3, and the light emitting portion 5 emits light. The light from the light emitting unit 5 is reflected by the reflecting surface of the reflector to obtain a low beam (passing beam), which is irradiated onto the road surface. By this low beam, a light distribution pattern for passing can be obtained.

  On the other hand, a voltage is applied to the common electrode 2 and the main electrode 4 through the common lead wire 82 and the main lead wire 84. Then, a main discharge arc (not shown) is generated between the discharge end portion 20 of the common electrode 2 and the discharge end portion 40 of the common electrode 4, and the light emitting portion 5 emits light. The light from the light emitting unit 5 is reflected by the reflecting surface of the reflector to obtain a high beam (traveling beam) and is irradiated onto the road surface. A light distribution pattern for traveling is obtained by this high beam.

  However, in the conventional discharge bulb B, no consideration is given to the relative wiring positional relationship between the three lead wires 82, 83, 84. That is, in the conventional discharge bulb B, the common lead wire 82 and the sub lead wire 83 are wired close to each other. For this reason, in the conventional discharge bulb B, an erroneous discharge occurs between the common lead wire 82 and the sub lead wire 83, and the discharge end portion 20 of the common electrode 2 and the discharge end portion 30 of the sub electrode 3 are connected. There may be a case where no sub-discharge arc occurs between the two.

Japanese Utility Model Publication No. 3-40756

  The problem to be solved by the present invention is that, in the above-described conventional discharge bulb, no consideration is given to the relative wiring positional relationship between the lead wires 82, 83, and 84, so that an erroneous discharge occurs between adjacent lead wires. There is a point to be.

  The present invention is characterized in that the lead wires are wired apart from each other.

  In the discharge bulb according to the present invention, the lead wires are wired in a state of being separated from each other, so that the number of cases where erroneous discharge occurs between the lead wires can be reduced as much as possible.

  Below, one example of the Example of the discharge bulb concerning this invention is demonstrated in detail based on FIGS. 1-3. In this embodiment, an example of use as a light source such as a headlamp for an automobile will be described. Note that the present invention is not limited to the embodiments. That is, the discharge bulb according to the present invention is also used for a light source other than a light source such as an automobile headlamp.

(Description of the configuration of the embodiment)
Hereinafter, the configuration of the discharge bulb in this embodiment will be described with reference to FIGS. In the figure, the same reference numerals as those in FIGS. 4 and 5 denote the same components.

  In the figure, reference numeral B1 denotes a discharge bulb according to this embodiment. In the discharge bulb B1 according to this embodiment, three lead wires, that is, a common lead wire 82, a sub lead wire 83, and a main lead wire 84 are wired apart from each other. That is, the common lead wire 82 is wired on the right side and slightly below the horizontal line HH when viewed from the front side (the side opposite to the base 9). The sub lead wire 83 is wired on the left side and slightly below the horizontal line H-H when viewed from the front side. Further, the main lead wire 84 is wired substantially at the center O when viewed from the front side.

  In the discharge bulb B1 according to this embodiment, three lead wires, that is, the common lead wire 82, the sub lead wire 83, and the main lead wire 84 are wired outside the optically effective range of the light emitting unit 5. Yes. That is, the optically effective range of the light-emitting unit 5 is such that the light distribution pattern for passing and the light distribution pattern for traveling are obtained when the discharge bulb B1 according to this embodiment is used as a light source such as a headlamp for an automobile. This is a range suitable for optical design and light distribution design, and is a range above the horizontal line HH (a range indicated by a two-dot chain line). The common lead wire 82, the sub lead wire 83, and the main lead wire 84 are located in a range below the horizontal line HH (a range other than the optically effective range of the light emitting unit 5).

(Explanation of working effects of the embodiment)
The discharge bulb B1 according to this embodiment is configured as described above, and the operation and effect thereof will be described below.

  First, a voltage is applied to the common electrode 2 and the sub electrode 3 via the common lead wire 82 and the sub lead wire 83. Then, a sub discharge arc (not shown) is generated between the discharge end portion 20 of the common electrode 2 and the discharge end portion 30 of the sub electrode 3, and the light emitting portion 5 emits light. The light from the light emitting unit 5 is reflected by the reflecting surface of the reflector to obtain a low beam (passing beam), which is irradiated onto the road surface. By this low beam, a light distribution pattern for passing can be obtained.

  On the other hand, a voltage is applied to the common electrode 2 and the main electrode 4 through the common lead wire 82 and the main lead wire 84. Then, a main discharge arc (not shown) is generated between the discharge end portion 20 of the common electrode 2 and the discharge end portion 40 of the common electrode 4, and the light emitting portion 5 emits light. The light from the light emitting unit 5 is reflected by the reflecting surface of the reflector to obtain a high beam (traveling beam) and is irradiated onto the road surface. A light distribution pattern for traveling is obtained by this high beam.

  The discharge bulb B1 according to this embodiment is wired with three lead wires, that is, the common lead wire 82, the sub lead wire 83, and the main lead wire 84 separated from each other. In particular, the common lead wire 82 and the sub lead wire 83 are greatly separated. For this reason, the discharge bulb B1 according to this embodiment has three lead wires, particularly the common lead wire 82, as compared with the conventional discharge bulb B in which the common lead wire 82 and the sub lead wire 83 are close to each other. And a case where erroneous discharge occurs between the sub lead wire 83 and the sub lead wire 83 can be reduced as much as possible.

  In the discharge bulb B1 according to this embodiment, three lead wires, that is, the common lead wire 82, the sub lead wire 83, and the main lead wire 84 are wired outside the optically effective range of the light emitting unit 5. Yes. In particular, the common lead wire 82 and the sub lead wire 83 are located outside the optically effective range of the light emitting unit 5, that is, below the horizontal line HH. For this reason, the discharge bulb B1 according to this embodiment has the three lead wires 82 even if the three lead wires 82, 83, 84 are wired apart from each other in order to prevent erroneous discharge. , 83, and 84 are wired outside the optical effective range of the light emitting unit 5 and do not block the optical effective range of the light emitting unit 5. As a result, the discharge bulb B1 according to this embodiment improves the light emission efficiency of the light emitting section 5, facilitates optical design and light distribution design, and, in addition, the degree of freedom in optical design and light distribution design. Will increase.

(Description of examples other than Examples)
In addition, in the said Example, the single glass tube structure of the glass tube 1 is made | formed. However, in the present invention, the glass tube 1 is used as an inner tube, an outer glass tube is provided outside the glass tube 1, and a double glass tube structure that protects the glass tube 1 of the inner tube by the outer glass tube is provided. The double glass tube structure may be fixed to an insulating base, and the three lead wires 82, 83, 84 may be connected to the terminal of the base.

  In the above embodiment, the glass tube 1 may be provided with a transparent heater or an opaque heater. In this case, the discharge state can be stabilized quickly by the heating action of the heater, and the light emission efficiency after the discharge state is stabilized can be improved.

  Further, in the above-described embodiment, the sizes of the discharge end portions 20, 30, and 40 of the three electrodes 2, 3, and 4 are substantially the same. However, in the present invention, the sizes of the discharge end portions 20, 30, and 40 of the three electrodes 2, 3, and 4 may be increased in accordance with the frequency of use, that is, the size of melting deterioration. In this case, since the melting deterioration of the discharge ends 20, 30, 40 of the three electrodes 2, 3, 4 can be made almost uniform, the durability of the discharge bulb B1 is improved, and the length of the discharge bulb B1 is increased. Life expectancy is achieved.

  Furthermore, in the above-described embodiment, the sizes of the discharge end portions 20, 30, and 40 of the three electrodes 2, 3, and 4 are substantially the same. However, in the present invention, the tips of the discharge ends 20, 30, and 40 of the three electrodes 2, 3, and 4 may have a pointed structure. In this case, electrons can easily fly from the tips of the discharge ends 20, 30, and 40 of the three electrodes 2, 3, and 4, and the discharge efficiency is improved. The load on the electric circuit including the circuit can be reduced, and the durability of the electric circuit is improved.

  Furthermore, in the above-described embodiment, a heat sink structure may be provided at the discharge ends 20, 30, 40 of the three electrodes 2, 3, 4. In this case, due to the effect of the heat sink, even if the electrode is heated by the discharge action, the heat is efficiently dissipated from the electrode, preventing the electrode from melting and improving the durability of the electrode of the discharge bulb. Is done.

  Furthermore, in the above-described embodiment, the portions 21, 31, 41 of the electrodes 2, 3, 4 are embedded in the pinch seal portions 62, 63, 64. However, in the present invention, the electrodes 2, 3, 4 may be connected to the lead wires through the metal foil in the pinch seal portions 62, 63, 64.

  Furthermore, in the above-described embodiment, the lead wires 82, 83, 84 may be covered with an insulating outer tube made of ceramic, for example, so that erroneous discharge can be prevented more reliably.

It is a front view which shows the Example of the discharge bulb of this invention. It is the II-II sectional view taken on the line in FIG. It is a III arrow directional view in FIG. It is a front view which shows the conventional discharge bulb. It is the VV sectional view taken on the line in FIG.

Explanation of symbols

B, B1 Discharge bulb 1 Glass tube 2 Common electrode 3 Sub electrode 4 Main electrode 20, 30, 40 Discharge end (one end)
21, 31, 41 Buried part (part)
22, 32, 42 Other end portion 5 Light emitting portion 62, 63, 64 Pinch seal portion 7 Discharge space 82 Common lead wire 83 Sub lead wire 84 Main lead wire 9 Cap HH Horizontal line

Claims (2)

In a discharge bulb capable of generating a plurality of discharge arcs in a discharge space,
A light emitting section that partitions the discharge space;
A common electrode, a sub-electrode, and a main electrode protruding in the discharge space;
A common lead wire connected to the common electrode, a sub lead wire connected to the sub electrode, a main lead wire connected to the main electrode, and
With
The common lead wire, the sub lead wire, and the main lead wire are wired apart from each other,
A discharge bulb characterized by that. The common lead wire, the sub lead wire, and the main lead wire are wired outside the optically effective range of the light emitting unit,
The discharge bulb according to claim 1.

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