JP2000106028A - Discharge lamp - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a discharge lamp not necessary for increasing the shape and not decreasing case strength even if an electronic ballast using two or more electrolytic capacitors is used. SOLUTION: This discharge lamp has a base 1; a fluorescent lamp 7; a holder 6; a voltage doubler rectifier circuit type electronic ballast 5 having two electrolytic capacitors 3, 4; and a case 2 having a cylinder part 10. Two grooves 8 are formed in the coaxial direction as the axis of the case 2 on the inner surface of the cylinder part 10. Parts of the capacitors 3, 4 are positioned within the grooves 8, and the capacitors 3, 4 are housed in the cylinder part 10. A recess 9 is formed on the outer surface of the cylinder part 10 other than the outer surface where the groove 8 forming a low strength part is positioned. The base 1 and the case 2 are fixed in the position of the recess 9 by caulking the base 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a discharge lamp.

[0002]

2. Description of the Related Art A discharge lamp having an electronic ballast has been put to practical use for the main purpose of energy saving illumination. In such a discharge lamp, for example, a bulb-type fluorescent lamp, a capacitor is used as an indispensable part in an electronic ballast for lighting the fluorescent lamp. In particular, since the electrolytic capacitor for smoothing is a component with a large shape and low heat resistance temperature, it greatly affects the life of the electronic ballast.Therefore, in the space inside the funnel-shaped case, the die with the lowest temperature is used. The electrolytic capacitor is housed inside the cylindrical portion provided with. Also, when two or more electrolytic capacitors are used, the outer diameter of the cylindrical portion cannot be increased due to the size limit of the base, and in the conventional case, two or more electrolytic capacitors are provided inside the cylindrical portion. They cannot be stored in parallel. For this reason, by increasing the shape of the case, a space having a low temperature is formed in the case, and the electrolytic capacitor is housed in the space.

[0003]

However, such a bulb-type fluorescent lamp has a large case shape, and therefore has a large overall shape. You will lose value. Therefore, there is a problem that an electronic ballast using a circuit method such as a voltage doubler circuit method or a partial smoothing circuit method using two or more large-sized electrolytic capacitors cannot be used.

In order to accommodate two or more electrolytic capacitors in the tubular portion, it is conceivable to increase the inner diameter of the tubular portion. However, there is a limit on the size of a base provided in the tubular portion. Therefore, the outer diameter of the cylindrical portion cannot be increased.
Therefore, if the inner diameter of the tubular portion is increased without changing the outer diameter of the tubular portion, the thickness of the tubular portion becomes thinner and the case strength is reduced.

According to the present invention, even when an electronic ballast using two or more electrolytic capacitors is used, the case shape is not increased in size as compared with the conventional case and the case strength is equivalent to the conventional case. It is an object of the present invention to provide a discharge lamp capable of performing the following.

[0006]

DISCLOSURE OF THE INVENTION The discharge lamp of the present invention comprises:
A base to be connected to a power supply, an arc tube, an electronic ballast having a capacitor that lights up the arc tube, and a case that has a cylindrical portion provided with the base and covers the electronic ballast. In a discharge lamp provided with the electronic ballast,
With at least one capacitor, on the inner surface of the cylindrical portion of the case, at least one groove is provided coaxially with the axis of the case, so that a part of the capacitor is located in the groove. It has a configuration in which the two or more capacitors are housed in a cylindrical portion of the case.

[0007] Thus, without enlarging the shape of the case, two or more capacitors of the electronic ballast can be housed in the cylindrical portion, and the strength of the case portion holding the base is ensured. This makes it possible to obtain a discharge lamp using an electronic circuit using two or more capacitors.

According to a second aspect of the present invention, in the discharge lamp of the first aspect, a concave portion is provided on an outer surface of the cylindrical portion of the case, and the groove is present on an inner surface of the case where the concave portion is located. However, the base is fixed to the case by caulking the base in the recess.

[0009] Thus, without increasing the size of the case, two or more capacitors of the electronic ballast can be housed in the cylindrical portion, and the strength of the case portion holding the base is ensured. This makes it possible to obtain a discharge lamp using an electronic circuit using two or more capacitors.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG. 1, a bulb-type fluorescent lamp according to an embodiment of the present invention has a metal base 1 having an inner diameter of 23 mm to be connected to a power supply, and a pair of electrodes inside. A fluorescent lamp 7 as a discharge lamp, a holder 6 for holding the fluorescent lamp 7, and a fluorescent lamp 7 mounted on the holder 6 to turn on the fluorescent lamp 7 and to include two cylindrical electrolytic capacitors 3 and 4 as circuit components. An electronic ballast 5 of a voltage rectification circuit type and a cylindrical portion 10 having a funnel shape and having a maximum outer diameter of 23 mm, a minimum inner diameter of 20 mm, and a length of 9 mm on the small diameter side.
And a case 2 having Cylindrical part 1 of case 2
0 is provided with a metal base 1.

A holder 6 is provided at a large diameter portion of the case 2, and the case 2 is provided on the holder 6 so as to cover the electronic ballast 5. Note that the thickness of the cylindrical portion 10 is 1.5 mm because a thickness of 1.5 mm or more is required to ensure strength.

As shown in FIG. 2, two grooves 8 are provided on the inner surface of the cylindrical portion 10 of the case 2 in a direction coaxial with the axis of the case 2. Then, as shown in FIG. 3 and FIG.
A part of the three capacitors 3 and 4 is located inside the groove 8,
Two capacitors 3 and 4 are housed in the cylindrical portion 10 of the case 2.

The groove 8 has a depth of 0.5 mm so that two column-shaped electrolytic capacitors 3 and 4 having a diameter of 10.5 mm can be housed side by side in the case axis direction. It is formed over the entire length of the cylindrical portion 10 in the direction. A concave portion 9 for fixing the base 1 and the case 2 is formed on the outer surface of the cylindrical portion 2. Care should be taken that the concave portion 9 is not formed on the outer surface of the portion where the groove 8 of the case 2 which is a low strength portion is located. Is formed.

The base 1 is inserted into the cylindrical portion 10,
The base 1 and the case 2 by caulking the base 1 at the position
Are fixed.

FIG. 5 shows a circuit diagram of the electronic ballast 5 used in the bulb-type fluorescent lamp of this embodiment. When the voltage on the diode 12 side is positive, a current flows through the diode 12 and the electrolytic capacitor 3, and the AC voltage obtained from the commercial power supply 11 through the base 1 is applied to the electrolytic capacitor 3 up to the peak voltage of the AC voltage. Is done. On the other hand, when the voltage on the diode 13 side is positive, a current flows through the electrolytic capacitor 4 and the diode 13, and the voltage up to the peak voltage of the AC voltage is applied to the electrolytic capacitor 4. Therefore, the peak voltage of the power supply voltage smoothed by adding the voltages of the electrolytic capacitors 3 and 4 to the inverter circuit 14 is 2
Double DC voltage will be supplied. Such a rectifier circuit system is well known as a voltage doubler rectifier circuit system.

As described above, according to the present embodiment, the cylindrical portion 1 having the lowest temperature in the space inside the case 2.
The two capacitors 3 and 4 can be housed in the same size as 0, and the case shape does not become larger than before, and the case strength is the same as before, and the electronic stability using two or more electrolytic capacitors A compact bulb-type fluorescent lamp using a vessel can be obtained.

In the present embodiment, the cross section of the groove 8 has an angular shape as shown in FIG. 2, but is not limited to this, and may have a semicircular groove shape or the like corresponding to the outer shape of the capacitor. The capacitors are described as electrolytic capacitors 3 and 4. However, film capacitors or ceramic capacitors may be used. The rectifier circuit may be a voltage doubler rectifier circuit, but may be a partially smoothing rectifier circuit. However, a metal halide lamp or the like may be used.

[0018]

As described above, according to the present invention, even when an electronic ballast using two or more electrolytic capacitors is used, the cylindrical portion which is the lowest temperature portion in the space inside the case is used. While being able to store two or more capacitors,
It is possible to provide a discharge lamp having a case shape that does not increase in size and has a case strength equivalent to that of the related art.

[Brief description of the drawings]

FIG. 1 is a cutaway front view of a main part of a bulb-type fluorescent lamp according to an embodiment of the present invention.

FIG. 2 is a plan view of the same case.

FIG. 3 is a plan view for explaining a case where two electrolytic capacitors are housed in the case.

FIG. 4 is a perspective view for explaining a case where two electrolytic capacitors are stored in the case.

FIG. 5 is a circuit diagram of a voltage doubler rectifier circuit used in an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Base 2 Case 3 and 4 Electrolytic capacitor 5 Electronic ballast 6 Holder 7 Fluorescent lamp 8 Groove 9 Depression 10 Cylindrical part 11 Commercial power supply 12, 13 Diode 14 Inverter circuit

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Tetsuya Tahara 1-1, Komachi, Takatsuki-shi, Osaka Matsushita Electronics Co., Ltd. F-term (reference) 3K098 CC62 DD20 DD37

Claims (2)

[Claims] 1. An electronic ballast having a base to be connected to a power supply, an arc tube, an electronic ballast for lighting the arc tube and having a capacitor, and a cylindrical portion provided with the base. Wherein the electronic ballast has two or more capacitors, and at least one groove is provided on the inner surface of the cylindrical portion of the case in a direction coaxial with the axis of the case. A discharge lamp, wherein the two or more capacitors are housed in a cylindrical portion of the case such that a part of the capacitor is located in the groove. 2. A concave portion is provided on an outer surface of a cylindrical portion of the case, and the groove is not present on an inner surface of the case where the concave portion is located. The discharge lamp according to claim 1, wherein the base and the case are fixed.