JPH043390Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an incandescent light bulb used as a light source for exposing a document in a copying machine.

[Prior art and its problems]

In a copying machine, in order to obtain a high-quality image with high reproducibility on a document, it is necessary to make the illuminance distribution on the photoreceptor surface uniform. In order to make the illuminance distribution on the photoreceptor uniform, it is necessary to irradiate the document surface with a predetermined illuminance distribution. Therefore, incandescent light bulbs for document illumination have a filament assembly, in which light-emitting parts and non-light-emitting parts are arranged alternately, arranged inside a long rod-shaped envelope along the tube axis, and the distance between the light-emitting parts and the light-emitting parts are adjusted. By appropriately determining the length of , a predetermined light distribution characteristic is obtained.

This non-light-emitting portion is often constructed by inserting a shorting metal rod into the filament coil and electrically shorting that portion. Then, ring anchors inscribed in the inner wall of the enclosure are attached near both ends of the short-circuiting metal rod by winding them over the filament coil, thereby holding the filament assembly on the tube axis of the enclosure.

By the way, there are two types of document illumination devices for copying machines: one type in which the light source moves to scan the document surface, and the other type in which the platen glass on which the document is placed moves. , large accelerations and vibrations are likely to be applied to the incandescent light bulb that is the light source, and if the short-circuiting metal rod and ring anchor are not firmly fixed, the ring anchor will move, causing the filament assembly to deviate from the tube axis, resulting in illuminance distribution. will change.

When fixing the ring anchor to the shorting metal rod, the wire for the ring anchor is tightly wound around the filament coil part into which the shorting metal rod is inserted using a winding machine, and when the winding is completed, the end is cut. ,
When cut, the wound portion loosens due to springback. For this reason, as mentioned above, vibrations applied to the incandescent light bulb cause the ring anchor to move, causing the filament assembly to deviate from the tube axis, seriously affecting the illumination distribution. The problem of wire breakage occurs.

[Purpose of invention]

Therefore, an object of the present invention is to provide an incandescent light bulb with stable light distribution characteristics by preventing movement of the ring anchor due to vibrations, etc., and holding the filament assembly firmly on the tube axis of the envelope.

[Structure of the idea]

The structure of the present invention is such that a filament assembly is arranged along the tube axis in which a light-emitting part made of a filament coil and a non-light-emitting part made of a shorting metal rod inserted into the filament coil are arranged alternately in a tubular enclosure. In the incandescent light bulb, a densely coiled filament coil is caulked near both ends of the shorting metal rod, causing the shorting metal rod to deform into a flat shape, and ring anchors are attached to these two flat caulking parts. It is characterized in that it is wound and attached to a densely coiled filament coil in a screwed state.

〔Example〕

The present invention will be specifically described below based on embodiments shown in the drawings.

The drawing shows an incandescent lamp for manuscript illumination rated at 260W. The envelope 1 is made of a long quartz glass tube, and a filament assembly 2 composed of one filament coil is arranged along its axis. The portions 4 are arranged alternately and are designed to obtain a predetermined light distribution characteristic. The light-emitting part 3 is a tungsten wire with an outer diameter of 0.12 mmψ wound into a dense coil, and the non-light-emitting part 4
, a loose coiled portion 41 and a dense coiled portion 4 formed by partially stretching a filament coil.
A short-circuiting metal rod 5 made of molybdenum and having an outer diameter of 0.4 mmψ is inserted into the place where the 2 and 2 are mixed together to electrically short-circuit and prevent light emission. Note that the number of filament coils is not limited to one, and may be one in which short-circuiting metal rods 5 are inserted into the ends of a plurality of filament coils. Both ends of the filament assembly 2 are connected to the crushing sealing portion 7 of the sealing body 1.
The external lead wires 9 are connected to molybdenum foil 8 and extend to the outside.

Here, the vicinity of both ends of the short-circuiting metal rod 5 are caulked with a press from above the densely coiled portion 42 of the filament coil, as shown in FIG.
The short-circuiting metal rod 5 at that portion is slightly flattened. The filament assembly 2 is held by a ring anchor 6, which has an outer diameter.
It is formed from a 0.20 mm ψ tungsten wire, and as shown in FIG.
It consists of a fixing part 63 wound around the shorting metal rod 5. Then, the fixing part 63 is wound by a winding machine around the flattened part of the short-circuiting metal rod 5 after it is caulked, while being screwed into the dense coiled part 42 of the filament coil. It is formed. Therefore, the tungsten wire of the fixing portion 63 is not wound in a circular shape, but rather squarely, so that the tungsten wire is more likely to be hardened by work than if it were wound in a circular shape. Therefore, even if the tungsten wire is cut after winding, spring back is unlikely to occur, and the shorting metal rod 5 is firmly fixed at the fixed position value.

When an incandescent lamp with such a configuration is turned on, the ring anchor 6 is firmly fixed to the flattened part of the short-circuiting metal rod 5 without springback, even if vibrations are applied to the incandescent lamp. Since the ring anchor 6 does not move and always holds the filament assembly 2 on the tube axis of the envelope 1, the light distribution characteristics do not change and the amount of light is stable. Therefore, if this incandescent lamp is used as a light source for illuminating a document in a copying machine, the illuminance distribution on the photoreceptor can always be made uniform, and high-quality copied images can be obtained.

[Effect of idea]

As explained above, in the incandescent light bulb of the present invention, densely coiled filament coils are caulked near both ends of the shorting metal bar to make the shorting metal bar flat, and the two flat caulking Since the ring anchor is installed by winding it around the stopper with the filament coil screwed, this winding part will not loosen due to springback, and therefore movement of the ring anchor due to vibration etc. is prevented. The filament assembly can be accurately held on the tube axis of the envelope, and an incandescent lamp with stable light distribution characteristics can be obtained.

[Brief explanation of the drawing]

Fig. 1 is a front view of the embodiment of the present invention, and Fig. 2 is a front view of the embodiment of the present invention.
It is a sectional view taken along the - line in the figure. 1... Envelope, 2... Filament assembly, 3...
...Light emitting part, 4...Non-light emitting part, 41...Loose coiled part, 42...Dense coiled part, 5...Metal bar for shorting, 6...Ring anchor, 61...Ring part, 63... ...Fixing part, 8...Molybdenum foil, 9...
...External lead wire.

Claims (1)

[Claims for Utility Model Registration] A filament assembly in which a light-emitting part made of a filament coil and a non-light-emitting part made of a shorting metal rod inserted into the filament coil are arranged alternately in a tubular enclosure along the tube axis. In an incandescent light bulb arranged in parallel, densely coiled filament coils are caulked near both ends of the shorting metal rod, and the shorting metal rod is deformed into a flat shape, and the two flat caulking parts An incandescent light bulb characterized by a ring anchor being wound and attached to a densely coiled filament coil.