JPH04262360A - Ring-form fluorescent lamp - Google Patents

Abstract

PURPOSE:To provide a ring-form fluorescent lamp, with which the mount is free from risk of being mounted inclined to the bulb axis and with which the same type lamp base can be mounted even to a bulb having a different curvature. CONSTITUTION:An electrode 6 is mounted sealedly at each end of a bulb 1, which is bent into a ring to construct a ring-form fluorescent lamp. Therein the two bulb ends are formed straight, which prevents a filament fitted sealedly at these ends from being located in eccentricity from the bulb axis. Also a common lamp base can be used because of unchanged curvature of the bulb ends even with changing dia. of the bulb ring, which should enhance the accuracy in fitting of the lamp base.

Description

[Detailed description of the invention]

0001

FIELD OF THE INVENTION This invention relates to annular fluorescent lamps.

0002

[Prior Art] An annular fluorescent lamp is constructed by bending a glass bulb into an annular shape, with electrodes sealed at both ends and a phosphor coating formed on the inner surface. Enclosed with rare gas. A cap is spanned between both ends of the valve.

0003

[Problems to be Solved by the Invention] However, in the conventional annular fluorescent lamp, as shown in FIG. 2, the bulb 10 has the same curvature throughout the circumferential direction, and therefore the end portions are also bent with the same curvature. ing. In the case of such a shape, when the mount 11 is sealed to the end, the filament 12 may be attached eccentrically outward from the circular bulb axis O-O, and as a result, the filament 12 approaches the wall of the bulb 10, causing the black cause Such blackening has the disadvantage of impairing the appearance and reducing life characteristics.

[0004] Furthermore, when the lamps are of different sizes, the diameters of the annular shapes are different and therefore the curvatures are different, but conventionally, the same shape of the base 15 is used for 28 watts, 32 watts, and 38 watts. Ta. In this case, if the shape of the cap 15 is formed to fit, for example, a 28 watt type bulb, there will not be enough room when attaching it to a 32 watt or 38 watt bulb with a different curvature, making the installation difficult, and slight molding variations may occur. However, installation may not be possible. For this reason, in order to adapt the lamp to all types of lamps, the cap must be shaped in advance to have some extra room, which has the drawback of increasing rattling.

The present invention was developed based on the above circumstances, and its purpose is to prevent the mount from being installed at an angle with respect to the valve axis, to prevent blackening of the valve, and to reduce the curvature. It is an object of the present invention to provide an annular fluorescent lamp in which the same type of base can be attached to different bulbs.

[0006]

[Means for Solving the Problems] The present invention is an annular fluorescent lamp formed by bending a bulb having electrodes sealed at both ends into an annular shape, and is characterized in that both ends of the bulb are straight.

[0007]

According to the present invention, since the end portions of the bulb are formed in a straight line, it is possible to prevent the filament sealed in these end portions from being installed eccentrically from the valve axis. Furthermore, even if the ring diameter of the valve changes, the curvature of the end of the valve does not change, so it is possible to use a common cap, and the fitting precision of the cap is increased.

[0008]

[Embodiment] The present invention will be explained below based on an embodiment shown in FIG. In the figure, 1 is a bulb of an annular fluorescent lamp, which is formed by bending a glass tube into a substantially annular shape. Both ends of the bulb 1 are opposed to each other, and have a linear shape over a predetermined length l. The length l of this straight part 2, 2
is 10 to 30 mm.

Mounts 3, 3 (only one is shown) are sealed at both ends. The mount 3 is constructed by sealing a pair of wells 5, 5 to a stem tube 4, and extending a filament 6 between the wells 5, 5.

The stem tube 4 is attached perpendicularly to the open end surface of the valve 1, and since the end of the valve 1 has a straight shape, the filament 6 is centered on the valve axis. I'm letting you do it.

[0011] A cap 7 is hung between both ends of the valve 1. The cap 7 may have a well-known structure, so a detailed explanation will be omitted. A phosphor film (not shown) is formed on the inner surface of the bulb 1, and mercury and rare gas are sealed inside the bulb 1.

In the annular fluorescent lamp having such a structure, both ends of the bulb 1 which is bent into an annular shape are formed in a straight line shape, so that the mount 3 sealed to these end parts 2, 2 is aligned with the bulb axis O. -It will no longer be installed tilted to O. Therefore, the filament 6 is prevented from being eccentric from the bulb axis OO, and the filament 6 is prevented from approaching the wall of the bulb 1. Therefore, blackening of the bulb 1 can be prevented, and deterioration in appearance and life characteristics can be prevented.

Furthermore, in the case of such a shape, even if the lamps have different sizes, the shapes of the end portions 2, 2 can be made the same or approximated. That is, as shown in Figure 1, lamp sizes of 28 watts, 32 watts and 38 watts
Watts, etc., the diameter of the annular shape will be different and the curvature will be different, but by making the end of each of these lamps into a straight shape, the structure of the end can be made to be the same or an approximate shape. be able to.

Therefore, even lamps of different sizes can share the same shape of the base 7, and in this case,
It is not difficult to attach the base 7 to each lamp, and it is possible to provide a margin for attachment even if there are variations in molding, and it is possible to prevent rattling and damage to the lamp.

The present invention is more effective for annular fluorescent lamps with a smaller annular diameter, that is, lamps with a smaller curvature.
It is particularly effective for lamps with bulb diameters of 5 to 25 mm and ring diameters of 50 to 250 mm.

[0016]

[Effects of the Invention] As explained above, according to the present invention, since the ends of the annular bulb are formed in a straight line, it is possible to prevent the filament sealed in these ends from being installed eccentrically from the valve axis. This prevents premature blackening of the bulb and improves its life characteristics. Further, even if the ring diameter of the valve changes, the curvature of the end of the valve does not change, so the caps can be used in common, and there are advantages such as higher fitting accuracy of the caps.

[Brief explanation of the drawing]

FIG. 1 is a plan view of an annular fluorescent lamp showing an embodiment of the present invention.

FIG. 2 shows a conventional annular fluorescent lamp, in which (a) is a plan view of the end of the bulb, and (b) is a sectional view thereof.

[Explanation of symbols]

1... Valve, 2... Straight section, 3... Mount, 4... Stem,
5...wells, 6...filament, 7...cap.

Claims (1)

[Claims] 1. An annular fluorescent lamp comprising a bulb having electrodes sealed at both ends and bent into an annular shape, characterized in that both ends of the bulb are straight.