JPH064528Y2 - Small light bulb - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a small light bulb, and more particularly to a small light bulb suitable for being applied to a date imprinting device of a camera.

(Prior Art and Problems Thereof) In general, the date imprinting device for a camera described above is such that the light from the light source is applied to the liquid crystal panel on which the date is displayed, and the light transmitted through the liquid crystal panel is used to date the film. Is imprinted on.

As a light source of the date imprinting apparatus described above, a small light bulb has been conventionally used because it has to be built in a camera.

FIGS. 2 (A) and 2 (B) show a conventional small light bulb, in which a stem 3 is disposed in a bulb 1 having an opening 2 at one end and hermetically sealed. Is composed of a pair of introduction lines 4 and 4 extending outside the bulb 1 and glass beads 5 that fix the introduction lines 4 and 4 and are welded inside the bulb 1 near the opening 2. ing. Both the introduction lines 4 and 4 are inserted through the beads 5,
A filament 6, which is a heat-generating light emitting element, is connected between the inner ends of the filaments 4.

With such a configuration, the filament 6 generates heat and emits light by supplying power to the filament 6 through the introduction lines 4 and 4, and this light is radiated to the outside through the tip of the bulb 1. Become.

By the way, in such a conventional small light bulb, the light traveling from the filament 6 toward the beads 5 is reflected by the outer peripheral surface 7 on the inner side and the outer peripheral surface 8 on the outer side of the bead 5, and is reflected by the convex outer peripheral surface 7 among them. Since the scattered light is diffused, a concentrated light amount in one direction cannot be obtained.
The light reflected on the outer peripheral surface 8 which is concave when viewed from the side is condensed to some extent and is emitted to the outside through the tip portion of the bulb 1. Therefore, in this small light bulb, not only the light directly emitted from the filament 6 to the outside but also the light reflected on the outer peripheral surface 8 of the bead 5 is also emitted to the outside. When used in a device, two kinds of light reach the liquid crystal panel, and there is a problem that a ghost phenomenon (double image) occurs on the date imprinted on the film surface.

(Purpose of Invention) The present invention overcomes the above-mentioned problems in the conventional one,
A small light bulb that allows only the light emitted from the filament directly to the outside to reach the object, so that when used in the date imprinting device of the camera, a clear date is imprinted on the film surface. The purpose is to provide.

(Summary of the Invention) The present invention hermetically seals a pair of introduction wires, in which filaments are connected in a valve having an opening at one end, by welding beads to the valve opening, through the beads. In the small light bulb, the bulb opening end projects outward from the welded portion between the bulb and the bead, and a recess is formed between the exposed inner surface of the bulb opening end side and the convex outer peripheral surface of the bead. It is characterized in that the convex outer peripheral surface of the bead located on the side and the concave portion are covered with a colored paint.

(Embodiment) Hereinafter, the present invention will be described with reference to an embodiment shown in the drawings. The same components as those of the conventional one described above are designated by the same reference numerals in the drawings, and the description thereof will be omitted.

FIGS. 1 (A) and 1 (B) show an embodiment of the present invention, in which the colored paint 9 covering the convex outer peripheral surface 8 of the bead 5 located on the opening 2 side of the valve 1 is the bead 5. The outer peripheral surface 8 is entirely baked.

At that time, as is apparent from the figure, the opening end of the bulb 1 projects outward from the welded portion of the bulb 1 and the beads 5, and the exposed inner surface of the bulb 1 on the opening end side and the convex outer peripheral surface 8 of the beads 5 are formed. A concave portion serving as a paint reservoir is formed therebetween, and the convex outer peripheral surface 8 of the bead 5 located on the opening side of the valve 1 is covered with the colored paint 9, and the concave portion is also covered with the colored paint 9. The colored paint 9 is dammed by the recess.

In this way, the colored paint 9 is stopped by the recesses, so that the colored paint 9 can be applied evenly and thickly on the convex outer peripheral surface 8 of the bead 5 which tends to be thin, and the coating film A sufficient light-shielding property can be secured.

The colored paint 9 is baked by injecting the colored paint 9 on the inner peripheral side of the opening 2 of the valve 1 after welding the beads 5 to the valve 1 and heating at a temperature of about 150 ° C. for about 50 minutes. The colored paint 9 may be simply applied and dried, but by baking as described above, after the small light bulb is soldered to the substrate (not shown), the colored paint 9 is melted by the solvent ethanol used for cleaning the flux. It is possible to prevent it.

According to the above-mentioned configuration, the light transmitted from the filament 6 through the beads 5 toward the beads 5 is absorbed by the colored paint 9 that covers the outer peripheral surface of the beads 5. There is no reflection on the outer peripheral surface 8, and therefore only the light emitted directly from the filament 6 is emitted from the tip of the bulb 1. As a result, if the small light bulb shown in FIGS. 1 (A) and (B) is used in the date imprinting device of the camera, only one type of light will pass through the liquid crystal panel, resulting in a clear date. It will be imprinted on the film surface.

It is conceivable that the convex outer peripheral surface 7 of the beads 5 in the bulb 1 is coated with a colored paint so that the outer peripheral surface 7 absorbs light. In this case, the outer peripheral surface 7 is the inner surface of the light bulb. However, there is a problem that the colored paint is decomposed and gasified to fill the inside of the light bulb, the vacuum degree inside the light bulb is lowered, and the life of the filament is shortened.

When the outer peripheral surface 7 of the beads 5 is coated with a colored paint,
The colored paint is coated before the hermetically sealing by the beads 5, but in this case, the colored paint must be partially coated on a portion other than the sealing surface by the beads 5, which makes the manufacturing extremely troublesome. Become.

In this respect, in the above-mentioned embodiment, the convex outer peripheral surface 8 of the beads 5 is coated with the colored paint, so that the life characteristics of the bulb are not adversely affected, and the colored paint is potted in the opening of the bulb. Since the surface 8 can be covered with the colored paint, its manufacture is facilitated.

(Effects of the Invention) As described above, according to the present invention, the valve opening end is projected outward from the welded portion between the valve and the bead so that the valve inner end is exposed between the exposed inner surface and the bead-shaped outer peripheral surface. Since a concave portion is formed on the bead and the convex outer peripheral surface of the bead located on the opening side of the valve and the concave portion are covered with the colored paint, the colored paint is dammed by the concave portion, and the colored paint becomes thinner. A small bulb that can be easily applied to the convex outer peripheral surface of the beads evenly and thickly throughout the entire surface, can sufficiently secure the light shielding property of the coating, and can reliably eliminate the irradiation of harmful reflected light it can. Further, it is possible to provide a small light bulb that can be easily manufactured without adversely affecting the life characteristics of the light bulb.

[Brief description of drawings]

1 (A) and 1 (B) are a front view and a side view showing an embodiment of a small light bulb according to the present invention, and FIGS. 2 (A) and 2 (B) are a front view and a side view showing a conventional small light bulb. It is a figure. 1 ... Bulb, 3 ... Stem, 5 ... Bead, 6 ... Filament, 7, 8 ... Peripheral surface, 9 ... Colored paint.

Claims (1)

[Scope of utility model registration request] 1. A small light bulb in which a pair of lead wires, in which filaments are connected in a bulb having an opening at one end, are hermetically sealed through the beads by welding beads to the bulb opening. The valve opening end projects outward from the welded portion between the valve and the bead, and a recess is formed between the exposed inner surface of the valve opening end side and the convex outer peripheral surface of the bead, and the valve opening end is located on the opening side of the valve. A small light bulb, wherein the convex outer peripheral surface of the beads and the concave portion are covered with a colored paint.