JPH0446370Y2 - - Google Patents

Description

[Detailed explanation of the idea]

[Industrial Application Field] The present invention relates to a tube-type incandescent light bulb. [Technical Background] Tube-type incandescent light bulbs are generally used in various fields as light sources or heat sources. For example, as an exposure light source for a copying machine, since it is easy to control the light distribution, conventionally a light emitting section consisting of a tightly wound coil is placed inside a glass tubular enclosure.
A tube-type incandescent light bulb is preferably used, which has a filament in which non-light-emitting portions and non-light-emitting portions in which shorting rods are inserted into a sparsely wound coil are arranged so as to extend along the tube axis. . Therefore, in order to obtain an appropriate light distribution, it is necessary that the filament be arranged with high accuracy along the tube axis of the tube-shaped enclosure. Under these circumstances, conventionally, an incandescent light bulb has been proposed in which both ends of a non-light-emitting part are held by reduced-diameter parts formed in a glass tube-shaped enclosure. [Problem to be solved by the invention] However, tube-type incandescent light bulbs used as light sources for exposure in copying machines are repeatedly turned on and off each time they are exposed to light, so they are used under harsh conditions. In an incandescent light bulb that has a structure in which both ends of the non-emitting part are held by reduced-diameter parts formed in a glass tube-shaped enclosure, the space around the non-emissive part is separated from the space surrounding the light-emitting part by the reduced-diameter part. When the light is turned on, the temperature of the space surrounding the non-light-emitting part becomes relatively considerably low, and the filled gas moves largely into the space surrounding the non-light-emitting part through the gap between the diameter-reduced parts. As a result, smooth heat convection of the sealed gas in the space surrounding the light emitting section becomes difficult, resulting in the problem of premature disconnection of the light emitting section. The present invention was developed based on the above-mentioned circumstances, and its purpose is to provide an incandescent light bulb that can prevent premature disconnection of the light emitting part. [Means for Solving the Problems] In order to achieve the above object, the present invention has a filament in which a single wire is wound and a filament is formed so that light-emitting parts and non-light-emitting parts are arranged alternately. In a tube-type incandescent light bulb arranged so as to extend along the tube axis of the molded envelope, and having a structure in which at least two points of the non-light-emitting portion are held by reduced diameter portions formed in the glass tube-type envelope. , the light emitting part consists of a tightly wound coil, the non-light emitting part consists of a sparsely wound coil, and the number of turns per unit length of the light emitting part is A,
When the number of turns per unit length of the non-light-emitting portion is B, the value of the ratio B/A between the two is 0.5 to 0.75. [Function] Since the light-emitting part is composed of a tightly wound coil and the non-light-emitting part is composed of a loosely-wound coil, at least two points of the non-light-emitting part are formed in the reduced diameter part formed in the glass tube-shaped sealing body. In a tube-type incandescent lamp with a structure in which the light-emitting part and the non-light-emitting part are held in place by Since the relationship between the number of turns A and the number of turns B per unit length of the non-light-emitting part is defined within a specific range, the temperature difference between the space surrounding the light-emitting part and the space surrounding the non-light-emitting part is suppressed to a small level due to heat generation in the non-light-emitting part. As a result, the heat convection of the filled gas in the space surrounding the light emitting section can be smoothly carried out without disturbing the light distribution, and early disconnection of the light emitting section can be effectively prevented. [Example] Hereinafter, an example of the present invention will be described. FIG. 1 is an explanatory diagram showing an embodiment of the present invention. 10 is a glass tubular enclosure, 20 is a reduced diameter part,
30 is a filament, and 40 is a lead. The filament 30 is formed by winding a single wire made of tungsten, for example, so that tightly wound coiled light-emitting parts 31 and loosely wound coiled non-light-emitting parts 32 are alternately located. Become. Since no shorting rod is particularly arranged in the coil inner space of this non-light emitting part 32, the surrounding space 51 of the light emitting part 31
and the surrounding space 52 of the non-light emitting part 32 are in a state of sufficient communication. Therefore, in the present invention, the light emitting part is adjusted such that the ratio B/A of the number of turns A per unit length of the light emitting part 31 and the number of turns B per unit length of the non-light emitting part 32 is 0.5 to 0.75. It is necessary to select the coil pitch of 31 and non-light emitting part 32. When the value of the ratio B/A is too small, heat generation in the non-light-emitting portion 32 is insufficient, resulting in a large temperature difference between the surrounding space 51 of the light-emitting portion 31 and the surrounding space 52 of the non-light-emitting portion 32. However, if the contact ratio B/A is too large, the non-light emitting part 32 will substantially emit light and will not function as a non-light emitting part. Since this becomes difficult, the light distribution becomes disordered, making it impractical. Each non-light-emitting part 32 of the filament 30 is connected to the glass tube-shaped enclosure 1 at two points on both ends thereof, for example.
The reduced diameter portion 20 formed at 0 is held in a state in which it lightly contacts the inner wall. This allows filament 3
0 is held in a proper posture extending along the tube axis of the tube-shaped enclosure 10. Here, the "reduced diameter part" is
When the tubular enclosure 10 made of glass is viewed from the tube axis direction, it refers to a portion where the inner wall of the tubular enclosure 10 is partially narrowed so as to be close to the tube axis. A predetermined amount of gas is sealed in the tubular enclosure 10 . As such a filler gas, for example, when constructing a halogen light bulb, an inert gas, a gas containing halogen, or the like is used. According to the embodiments described above, in the tube-type incandescent lamp which has a strong holding structure by holding both ends of the non-light-emitting portion 32 by the diameter-reduced portions 20 formed in the tube-type enclosure 10 made of glass, the light-emitting portion 31 is Since the structure is made of a tightly wound coil and the non-light emitting section 32 is formed of a sparsely wound coil, the space 33 within the coil of the non-light emitting section 32 separates the surrounding space 51 of the light emitting section 31 and the surrounding space 52 of the non-light emitting section 32. are fully connected, and the light emitting part 3
Since the relationship between the number of turns A per unit length of 1 and the number of turns B per unit length of the non-light-emitting part 32 is regulated within a specific range, the heat generation of the non-light-emitting part 32 causes the light-emitting part 31 to
The temperature difference between the surrounding space 51 of the light-emitting part 32 and the surrounding space 52 of the non-light-emitting part 32 is suppressed to a small value, and as a result, the thermal convection of the filled gas in the surrounding space of the light-emitting part 31 is smoothed without disturbing the light distribution. Therefore, early disconnection of the light emitting section 31 can be effectively prevented. Therefore, even when used under harsh conditions where the light is repeatedly turned on and off, such as when used as an exposure light source for a copying machine, it is possible to obtain an appropriate light distribution and have a long service life. can get. [Example] Based on the configuration shown in Figure 1, the ratio B/A of the number of turns A per unit length of the light-emitting part and the number of turns B per unit length of the non-light-emitting part is shown in Table 1 below. We prototyped tube-type incandescent light bulbs with the same configuration except for various changes as shown in Figure 2, and conducted experiments in which these tube-type incandescent light bulbs were actually turned on and off in a lighting mode in which they were turned on for 4.3 seconds and then turned off for 3.7 seconds. , the light distribution and service life were investigated. The results are also shown in Table 1 below.

[Effect of idea]

As explained above, according to the present invention, in a tube type incandescent light bulb having a structure in which at least two points of the non-light emitting part are held by reduced diameter parts formed in a glass tube type enclosure, the light emitting part is sealed tightly. In addition to making the non-light-emitting part a loosely wound coil, the ratio of the number of turns per unit length of both B/A was regulated within a specific range, so that the space around the light-emitting part and the non-light-emitting part were The surrounding space is sufficiently communicated with the coil space of the non-light-emitting part, and the temperature difference between the space around the light-emitting part and the surrounding space of the non-light-emitting part is suppressed to a small level due to the heat generation of the non-light-emitting part. Thermal convection of the filled gas in the space surrounding the light emitting section can be smoothly carried out without disturbing the light distribution, and early disconnection of the light emitting section can be effectively prevented. Therefore, even when used under harsh conditions where the light is repeatedly turned on and off, such as when used as an exposure light source for a copying machine, it is possible to obtain an appropriate light distribution and have a long service life. can get.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing an outline of an embodiment of the present invention. DESCRIPTION OF SYMBOLS 10... Glass tubular seal, 20... Reduced diameter part, 30... Filament, 31... Light emitting part, 3
2... Non-light-emitting part, 40... Lead, 51... Space surrounding the light-emitting part, 52... Space surrounding the non-light-emitting part.

Claims (1)

[Claims for Utility Model Registration] A filament in which a single wire is wound so that light-emitting and non-light-emitting parts are alternately located, and the filament extends along the tube axis of a glass tube-shaped enclosure. A tube-type incandescent lamp having a structure in which at least two points of the non-light-emitting portion are held by a diameter-reduced portion formed in the glass tube-type enclosure, wherein the light-emitting portion is made of a tightly wound coil. , the non-light-emitting part consists of a loosely wound coil, and when the number of turns per unit length of the light-emitting part is A and the number of turns per unit length of the non-light-emitting part is B, the ratio of both is B/A. Tubular incandescent lamp characterized by a value of 0.5 to 0.75.