JPS59130062A - Tungsten halogen lamp - Google Patents

Abstract

PURPOSE:To prevent the occurrence of erosion due to those of blackening and/or excess halogen, by having an bulb constituted of a silica glass produced by adding at least a sort of either aluminum oxide or iron oxide. CONSTITUTION:In case of such a tungsten halogen lamp as above 10W/cm<2> in tube wall load being used in a state that temperature in a bulb wall is not heatedly saturated, when a bulb is constituted of silica glass produced by adding at least a sort of aluminum oxide or iron oxide, this bulb absorbs infrared rays radiated out of a filament, therefore bulb temperature can be kept up more than the minimum temperature required for a halogen cycle, while the tube wall blackening caused by a shortage of the bulb temperature also can be prevented and, what is more, since there is no mercury to seal excess halogen inside, erosion against a sealing member by the halogen can be checked. For your information, it is desirable that the rate of aluminum oxide and iron oxide in quantity to be added to the silica glass is set to 0.05-7wt% in aluminum oxide as total aluminum and to 0.05-3.5wt% in iron oxide as total iron.

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to an improvement in a low-voltage halogen bulb used in conditions where the bulb wall temperature is not thermally saturated.

[Technical background of the invention]

The applications of halogen light bulbs are increasingly expanding due to their excellent features such as small size, high output, high efficiency, and high brightness. For example, the use of this type of light bulb as a light source for exposure of slave copiers is rapidly increasing. This halogen light bulb for exposure has multiple filaments installed along the tube axis in order to obtain uniform light distribution, and the N1 filaments are short-circuited with a short line made of high-melting point metal such as tungsten or molybdenum so that no light is emitted. Furthermore, if necessary, the filament is supported on the inner wall of the tube with an anchor made of a high melting point metal. Due to the characteristics of its use, it normally operates with a blinking cycle of several seconds.

[Problems with background technology]

Since such a halogen light bulb is turned off while the bulb wall temperature rises, the bulb wall temperature does not reach a temperature sufficient to cause a halogen cycle. This makes it very difficult to determine the optimal amount of halogen to be encapsulated in this type of bulb. Therefore, in order to prevent the bulb wall from becoming black, it is necessary to fill in an excess amount of halogen that is greater than the necessary amount. As a result, the low-temperature mounting members, that is, the inner conductor wires, short lines, and anchors are corroded by the excess halogen, and the lamp cannot be lit after several hundred flashes. Also,
If the amount of halogen is reduced in consideration of corrosion caused by halogen in the low-temperature part, in this case, the tube wall will darken after several thousand flashes, the light output will decrease, and the tube will become completely useless as a light source for exposure. .

Even if an appropriate amount of halogen for practical use is found through experimentation, the range is extremely narrow, and the control of the amount of halogen, including the amount of impurities that may be introduced into the bulb during light bulb manufacturing, is a highly advanced laboratory method. It requires precision and is not suitable for industrial use.

[Purpose of the invention]

Even if the present invention is used in a state where the valve wall temperature is not thermally saturated, the valve wall will not blacken until the end of its life, and the mounting member will not be corroded by halogen before the rated life. The purpose is to provide halogen light bulbs.

[Summary of the invention]

In cases where the pipe wall load is 10 W/cni or more, the valve is coated with at least one of aluminum oxide and iron oxide.
By being made of quartz glass with added seeds, the bulb selectively absorbs infrared rays of the light emitted from the filament, which allows the bulb to be used even when the temperature of the bulb wall is not thermally saturated. In addition, the bulb wall temperature is raised to a temperature sufficient to cause a halogen cycle, thereby eliminating the risk of blackening or corrosion due to excess halogen.

[Embodiments of the invention]

The details of the present invention will be explained using the halogen light bulb for a copying machine shown in the first figure as an example. (1) is a quartz glass straight tube valve, (
2), (2) are sealing parts formed by crushing and sealing both ends of this valve (1), and (3) l (3) are these sealing parts I.
t(2+.

Molybdenum introduced foil embedded in (2), (4), (4)
Connect these introduction foils (3) and (3) to the valve (1)
The inner conductor wires (5), (5)... extending to the mouth are short-circuited between these inner conductor wires (4), (4) (6), (61.
Multiple tungsten filaments connected in series via... (7), (7)... vocal contact wires (6), (6)
The anchors (8) and (8) that supported ... are the introduction foils (3
), (3) and is a terminal attached to the end face of the sealing parts (2,), (2+).In the bulb (1), a predetermined amount of halogen, such as chlorine, hydrogen and argon, etc. Enclosed with active gas.

The power of the tube wall of this example light bulb is 10 W/crrt.
That's all. In the present invention, the tube wall load means that at a portion where the light emitting parts of the filaments (5), (5)... It is the total value obtained by dividing the filament consumption in that part by the inner surface area of the tube.

For example, if there are 10 filaments (5), (51...), the power consumption of each filament is 10VXO, /
Assume that it is A-1W. And each filament (51
, (51...), assuming that the inner surface area of the tube corresponding to the light emitting section is 0 and 1 ca, respectively, the tube wall load is (IWXIO) ÷ (0, 1o4x 10 ) = 10W/
cnt.

The quartz glass constituting the bulb (1) is doped with at least one of aluminum oxide and iron oxide. In the present invention, the contents of aluminum oxide and iron oxide are expressed in weight percent of the aluminum and iron elements contained in the quartz glass, and are referred to as total aluminum and total iron.

Such halogen light bulbs for copying machines can be used even under special blinking conditions, such as turning on for 3 seconds and turning off for 30 seconds, even if only a few copies are being made. It must be possible to avoid reaching the end of its lifespan due to a decrease in luminous flux due to blackening or uneven light distribution. Of course, in the normal blinking cycle of 1°5 seconds on and 0.5 seconds off, it is about 4
Since it is required to withstand over 00,000 flashes, tests were conducted under both conditions.

The prototype light bulb has a rating of 80V, 300W, and a tube wall load of 53W/
cytt's halogen bulb with the above structure, bulb (1)
Additives are added to the quartz glass of 2.0% by weight of total aluminum and 1.2% by weight of total iron. And, inside the valve (1) is trichloromethane (CHC4) 16
Argon containing 00P and a trace amount of hydrogen was sealed at 3 atm. In addition, for comparison purposes, a comparison light bulb was manufactured in which the bulb was made of ordinary quartz glass containing neither aluminum oxide nor iron oxide, and the other structures were the same as the above-mentioned prototype light bulb. Therefore, we turned on the above prototype light bulb and the above comparison light bulb for 3 seconds, and
When compared in a flashing test with the light turned off for 0 seconds, a comparative light bulb using ordinary quartz glass began to darken after 18,000 to 19,000 flashes, and could no longer function as a light source for copying. lost. On the other hand, the above-mentioned prototype light bulb belonging to the present invention is about 3
．． Useful as a light source for copying up to 20,000 times, about 1
．． It was confirmed that the lifespan was extended by nearly 7 times. In addition, by changing the power consumption, tube diameter, and filament length, we varied the tube wall load and conducted a 3-second lighting test and a 300-second lighting flashing test to investigate the decrease in luminous flux that occurs as a result of blackening of the tube wall, and the light distribution. We investigated the number of times the light would blink until it no longer functioned as a light source for copying due to unevenness. This result is the second
As shown in the figure. In the figure, the horizontal axis shows the pipe wall load in units of w/d.
The vertical axis shows the number of blinks until it becomes unusable due to blackening, and the curve shows the life characteristics of the prototype light bulb mentioned above,
Curve (B) shows the life characteristics of the above-mentioned comparative light bulbs. This figure clearly shows that above a certain tube wall load, the life of the light bulb of the present invention is significantly extended compared to the conventional light bulb of the same type. And the tube wall load is 10W
/cnl When the temperature of the so-called tube wall is extremely low, it has been experimentally observed that the life span is slightly extended, but even with the present invention, a sufficient effect could not be obtained.

The above-mentioned life extension was achieved as a result of the quartz glass to which aluminum oxide and iron oxide were added, which is a feature of this example light bulb, absorbs infrared rays and becomes high temperature. This is clear from the fact that the temperature is always 100 to 120°C higher than when ordinary additive-free quartz glass is used.

Therefore, the infrared absorption ability of aluminum oxide and iron oxide in quartz glass will be limited in the presence of either aluminum oxide or iron oxide; however, with iron oxide alone, the infrared absorption ability will gradually decrease with long-term use, but oxidation If aluminum and iron oxide coexist, the infrared absorption ability will be stable and it can withstand long-term use.

Furthermore, appropriate amounts of Σaluminum oxide and iron oxide added to quartz glass satisfy the purpose of the present invention, which is used under the condition that the temperature of the bulb wall is not thermally saturated, based on the current quartz glass manufacturing process. Furthermore, as a result of various experiments, the industrially profitable range was determined as follows. That is, aluminum oxide is 0.05 to 7% by weight as total aluminum, and iron oxide is 0.05% by weight as total iron.
05 to 3.5% by weight. That is, it is desirable that at least one of aluminum oxide and iron oxide be within the above range.

In addition, in the above-mentioned embodiment, a halogen bulb was described in which a plurality of filaments were connected in series via a short-circuit wire, but the present invention is not limited to this, and a single filament may be sealed. Any method may be used to form the non-light-emitting portion, and in short, any method can be applied to any method used in a state where the bulb wall temperature is not thermally saturated.

Further, the halogen is not limited to the above-mentioned chlorine.

The present invention can also be applied to cases where the cooling condition changes depending on the wind speed, such as natural wind cooling.

〔Effect of the invention〕

The halogen light bulb of the present invention is used when the bulb wall temperature is not thermally saturated and the bulb wall load is 10 W/cr1 or more. Since it is configured with , it is possible to maintain radiation from the filament, preventing blackening of the tube wall due to insufficient bulb temperature.Also, since there is no need to seal in excess halogen, corrosion of the sealing member due to halogen can be prevented. Even under the above-mentioned special conditions of use, a significant life extension was achieved.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an embodiment of the halogen light bulb of the present invention, and FIG. 2 is a correlation diagram showing the correlation between tube wall load and blackening. (1)...Valve (4)...Inner conductor (5
)...Filament (6)...Short wire (7)
・Anchor agent Patent attorney Inoue - Male

Claims (2)

[Claims] (1) A tungsten filament is sealed in a quartz glass bulb, and the necessary halogen and inert gas are sealed.9 The tube wall load is 10 W/1, which is used in a state where the temperature of the bulb wall is not thermally saturated. A halogen light bulb having a capacity of ca or more, wherein the quartz glass is doped with at least one of aluminum oxide and iron oxide. (2) Aluminum oxide in the quartz glass is within the range of 0.05 to 7% by weight as total aluminum, and iron oxide is within the range of 0.05 to 3.5% by weight as total iron. A halogen light bulb according to claim 1.