JPS5837663B2 - Teiatsu Gashodento - Google Patents

Description

[Detailed description of the invention] The present invention relates to a low pressure gas discharge lamp.

It is known to increase the lamp current to increase the lamp power in order to obtain more radiation from this type of lamp.

In this case, increasing the discharge lamp power to a value greater than a predetermined value generates more useful radiation, but has the disadvantage that the efficiency with which the electrical energy supplied to the discharge lamp is converted into this useful radiation decreases. be.

Furthermore, increasing the current strength increases losses in a ballast, such as a choke or a resistor, placed in series with the discharge lamp.

A known method for eliminating the above-mentioned drawbacks is to reduce the surface of the wall of the discharge vessel, for example in US Pat. No. 2,950,410
It is notched and enlarged as described in the patent specification.

This makes the discharge lamp more complex and therefore more expensive to manufacture due to the drawbacks of the known discharge lamps mentioned above, and the degree of improvement is very small.

Furthermore, the grooves provided on the outer surface of the discharge lamp may accumulate dust, which reduces the light output over time.

Another example of a discharge lamp is U.S. Patent No. 3,290,53
No. 8, which describes a low-pressure mercury vapor human discharge lamp with an inner tube.

In this case too, the improvement with respect to the increase in light output when the load increases is very small compared to the same discharge tube without an inner tube.

The present invention provides a low-pressure gas discharge lamp in which a fibrous solid having a structure that allows gas discharge to pass through is provided in a space between electrodes, in which the solid is made of quartz glass wool, Gehlenite glass wool, or tungsten wool. Alternatively, the solid body may be present over at least 1/2 of the distance between the electrodes and distributed sparsely over the discharge space, and the solid body may be present over at least 1/2 of the distance between the electrodes and distributed sparsely over the discharge space, and the solid body may be present over at least 1/2 of the distance between the electrodes and distributed sparsely over the discharge space. It is characterized in that an amount of said solid ranges from 10 m9 to 1.25.10 771 m on average.

The present invention establishes the fact that by introducing solids of the above-mentioned materials into the discharge space in the above-mentioned proportions, the light output and efficiency are increased compared to when no solids are introduced into the discharge space,
It was based on this recognition.

In the present invention, the spacing between each fiber of solids is relatively large and only a few fibrous solids are present in the discharge space.

Here, the inter-electrode distance means the distance between the electrodes measured along the axis of the discharge space.

By making the solid matter, which does not necessarily have to be a continuous aggregate, exist in the discharge space, it is possible to significantly increase the discharge lamp voltage when the intensity of the current flowing through the discharge lamp remains the same. The advantage is that the above-mentioned drawbacks caused by an increase in the discharge lamp power due to an increase in the discharge lamp current in the known discharge lamps are also considerably reduced.

The structure according to the present invention is not only applicable to the discharge lamp according to the above-mentioned US patent specification, but also to a wider range of ordinary discharge lamps.

It has been experimentally confirmed that the effects described above can be obtained by the presence of the solid in the amount within the range described above.

Further, according to the present invention, since the required discharge lamp current is lower than that of the discharge lamp without solid matter, the loss in the electrodes and the loss in the ballast are reduced for the same discharge lamp power.

This means that the light output per unit volume of the discharge lamp can be significantly increased without increasing the energy consumption by the discharge lamp and the ballast.

French Patent No. 1 discloses the provision of a solid body made of glass or metal between the electrodes of a low-pressure mercury vapor discharge lamp having a luminescent wall to increase the light output per unit volume of the discharge lamp. 0 2 fi. It is described in the specification of No. 044 and is known.

These solids can be in the form of disks, tube spirals, or can be surrounded by glass wool.

The purpose of this French Patent Specification is to increase the light output per unit volume as mentioned above, but what conditions must be met to achieve this increase in light output, especially the amount and distribution of solid materials? There is no description of how the conditions regarding the state need to be satisfied.

If the structure of the solid is too dense, a stable discharge cannot be achieved, while if the solid is structured too sparse, no significant effect can be obtained.

It is not necessarily necessary to provide a solid body with a sparse structure over the entire distance between the electrodes in the discharge space.

That is, in order to properly distribute the radiation, it is generally desirable to have solid matter present over at least 80% of this distance.

Although the presence of a solid over more than 50% of the distance between the electrodes significantly increases the light output and efficiency compared to the absence of a solid, it is important to note that the majority of discharge lamps have a high light output with a uniform distribution. In order to
It is necessary to have more than one person in charge.

In the average tubular lamp according to the invention, the distance between the electrodes divided by the average diameter of the cross section of the furnace space perpendicular to the discharge axis was always greater than 5.

Therefore, in a preferred embodiment of the discharge lamp according to the invention, the distance between the electrodes divided by the average diameter of the cross section of the discharge space perpendicular to the discharge axis is 5.
It is preferable to make it larger than .

In this case, the process of producing radiation in the orthogonal space is optimally performed.

The loosely structured solid in the discharge lamp according to the present invention may be composed of glass wool, such as quartz glass wool, or metal wool, such as fibrous wool (fiber-like material twisted into wool) such as tungsten wool. It was confirmed through experiments that this is preferable.

Thus, the selection of such materials resulted in higher light output and efficiency than with other fibrous wools, such as asbestos.

In a particular embodiment of the discharge lamp according to the invention, the metal wool can be provided with an electrically insulating material, preferably as a coating, in order to obtain a suitable potential distribution over the loosely structured solid body.

Even with the use of metal wool that is not coated with electrically insulating material, no discharge short-circuiting occurs due to the metal wool.

The reason for this is that the metal wool is electrically charged with more negative electrons than the plasma in the discharge space, so that the discharge does not come into contact with the metal wool, ie the metal wool is electrostatically shielded from the discharge.

Another reason is that the impedance of the metal wool is higher than the impedance of the discharge.

However, to eliminate ignition problems, it is preferable to coat the metal wool with an electrically insulating material as described above.

Metal wool coated with electrically insulating material is more rigid than fibrous wool made only of insulating material (this also applies to uncoated metal wool).
, the density distribution state of this metal wool remains more constant during the life of the discharge lamp than that of wool made only of insulating material.

If this distribution fluctuates locally and some areas become too dense, the discharge becomes unstable.

The average fiber diameter of fibrous wool, e.g. metal wool, is 5μ
It is preferable to select it in the range of ~100μ.

The reason for this is that within this range, a wool-like solid with a loose structure can be easily obtained.

In a special embodiment according to the invention, loosely structured solids can be made luminescent, for example by glass coated with a luminescent material such as calcium halophosphate activated with manganese and/or antimony. It can be constructed.

Loosely structured solids should not absorb useful radiation that can be present in both the visible and ultraviolet parts of the radiation spectrum (e.g. ultraviolet light in the case of low-pressure mercury vapor discharge lamps, yellow visible light in the case of low-pressure sodium vapor-filled discharge lamps). , the radiation output of the discharge lamp according to the invention becomes extremely high.

This can be achieved by selecting a loosely structured solid material such that this effective radiation is satisfactorily transmitted or reflected.

If the material of the loosely structured solid itself absorbs the useful radiation, the loosely structured solid can be provided with a surface coating that reflects the useful radiation.

This coating can be composed of, for example, zirconium oxide, magnesium oxide or barium sulfate.

With the surface coating, the effective radiation is reflected in the direction of the discharge lamp wall, so that the light output emitted from the discharge lamp wall to the outside increases.

For example, if a luminescent coating is applied to the inner surface of a glass container of a discharge lamp, the ultraviolet rays reflected in the manner described above increase the visible light conversion efficiency of the luminescent coating.

Particularly when the dimensions of the discharge lamp are small, the temperature in the discharge space can reach values that exceed the critical vapor pressure for optimal conversion of electrical energy into useful radiation.

According to the invention, therefore, a device can be provided for obtaining an optimum vapor pressure for converting electrical energy into useful radiation.

For example, by providing a radiation shield on the electrode stem, the entire or part of the discharge lamp can be cooled, thereby increasing the conversion efficiency.

Another means of achieving this objective is to provide a vapor pressure regulating alloy within the discharge space.

Amalgams of mercury and indium can be used in low pressure mercury vapor discharge lamps.

The invention is applicable to various types of low pressure gas discharge lamps, typical examples being low pressure mercury vapor vapor discharge lamps and low pressure sodium vapor vapor discharge lamps with or without luminescent coatings.

The discharge lamp according to the invention has a very high radiation output per unit volume and can therefore be satisfactorily used for copying purposes.

In this case, the discharge lamp can be designed, for example, as a so-called aperture lamp (reflector lamp), which makes it possible to obtain a very intense directional light beam.

On the other hand, extremely compact fluorescent lamps are available which provide a large light output from a small overall volume.

It is, of course, desirable that the loosely structured solid material not interfere with the discharge lamp during its manufacture and during its life.

For this reason, it is preferable to select materials that emit as little gas as possible and that are not eroded and degraded by gas discharges.

Since the gas discharge in low-pressure sodium vapor discharge lamps is extremely powerful, it is desirable that the loosely structured solids contained in such lamps be antiseptic against sodium.

For this purpose, Gehlenite (2CaO・Al20
A loosely structured solid coated with a certain Gehlenite glass or a glass having a combination of 3.Sin2) is preferred.

Gehlenite glass is a material that does not corrode with sodium, and there is no need to use Gehlenite glass in discharge lamps that do not contain sodium.

The invention will be explained with reference to the drawings.

FIG. 1 is a sectional view showing an example of a low-pressure mercury vapor human discharge lamp according to the present invention.

The discharge lamp of this example is provided with a glass container 1, on which a luminescent coating 2 can be formed, for example, with calcium halophosphate activated with manganese and/or antimony. Cover.

This discharge lamp contains mercury vapor and one type of rare gas or a mixture of multiple types of rare gases.

Thermionic emission electrodes 3 and 4 are provided at the ends of the discharge space.

A glass wool body 5 of quartz that is lightly molded without being strongly crushed is housed in the discharge space over almost the entire space.

Another example of the discharge lamp according to the invention shown in FIG. 2 also houses a lightly molded glass wool body 6 in the same way as in FIG.

This glass wool body 6 is not made into a continuous body, but is made up of three small bodies 7,
Divided into 8 and 9.

A space is provided between these small bodies 7, 8 and 9, and between these small bodies and the electrode, in which no glass wool body is accommodated.

The sum of the lengths 1 of these bodies, measured along the discharge axis, is greater than 7 of the distance between the electrodes, preferably about 88% of this distance between the electrodes.

The reason is as stated in the preamble of the specification.

FIG. 3 shows a modification of the discharge lamp shown in FIG. 1, in which the discharge tube is curved into a U-shape.

A discharge lamp according to still another example of the present invention shown in FIG. 4 is provided with a U-shaped discharge tube 10, which is connected to an outer container 13
Surrounded by.

Further, thermionic emission electrodes 11 and 12 are provided at both ends of the discharge space.

A lightly shaped gehlenite glass wool body 15 is housed in this discharge space over its entire space.

The results of a number of measurements made on the 40 W low pressure mercury vapor human discharge lamp according to FIG. 1 are shown in Table I below.

This discharge lamp was filled with 58 µm of quartz wool with a thickness of 10 µm, and 1 torr of mercury and neon (MmHg,
).

In this case, the average per 17n1iL of discharge space is 1
A glass wool body of 0 m9 was present.

The results of a number of measurements carried out on the 40 W low-pressure mercury vapor personal discharge lamp according to FIG. 1 and on several discharge lamps of the same construction as this lamp but without the filling body 5 are shown in Table 2.

In this table ■, 68.7% Si02 and 2.98% Si02
B203 with a weight of φ, Na20 with a weight of 9.1, and 10
．． K20 with 85 weight and BaO with 6.85 weight,
, 1.5 weight of A4,03 and 0.05 weight of SrO
14 pieces of glass wool with a thickness of 36 μm containing the composition of
The light output and efficiency of a discharge lamp according to the invention filled with 0 m9 were compared with the corresponding values of a discharge lamp without glass wool.

Both of these discharge lamps contained a gas mixture of 75 volumes of argon and 25 volume percent neon and 2.5 volumes of mercury.
It was sealed at a pressure of torr (++tiHg).

As is clear from Table 1, the light output per unit volume of the low-pressure mercury vapor discharge lamp according to the present invention is greater than that of the discharge lamp without glass wool.

Furthermore, as is clear from Table 1, the efficiency of the discharge lamp according to the present invention has increased considerably.

The reason for this is that in the discharge lamp according to the present invention, the current intensity (m
This is because the A value) decreases significantly.

Although high-efficiency high-pressure gas discharge lamps have been proposed, solids with a loose structure such as glass wool cannot be placed in such high-pressure gas discharge lamps.

The reason for this is that in high-pressure gas discharge lamps, the loosely structured solid is destroyed by discharge.

Furthermore, it has been found that, according to the invention, the efficiency of a discharge lamp with the required ballasts connected in series is increased by approximately 60%.

This also depends on the fact that the losses occurring in the ballast and the electrodes are considerably reduced because the current strength is considerably reduced.

In the case of this discharge lamp, the average value per 17IL7iL of discharge space is 2.5X]. O ■glass wool was present.

The measurement results of a 20W low-pressure mercury vapor human discharge lamp containing the filler 5 and a 20W low-pressure mercury vapor human discharge lamp that is structurally similar but without the filler are shown in Table (2).

In Table 1, the light output and efficiency of a discharge lamp according to the invention filled with 20 μm of 10 μm thick quartz glass wool are compared with the corresponding values for a discharge lamp without quartz glass wool.

Both of these lamps were filled with a gas mixture of 72 volumes of neon and 28 volumes of helium and mercury at 6 torr (miH).
It was sealed at the pressure of g).

As is clear from Table 2, the efficiency of the discharge lamp with the required ballasts connected in series was twice that of the discharge lamp without quartz glass wool.

In this case, the average per volume 17n11 is 2X10-
'■Glass wool body was made to exist.

In addition, in the case of a discharge lamp with an operating voltage of 130 V and no quartz glass wool, the power is over 40 watts with almost no increase in light output, so the lamp efficiency is 29
significantly less than lumens/watt.

In the case of a U-shaped discharge lamp (FIG. 3), it is possible to obtain a discharge lamp of approximately the same dimensions as an incandescent lamp, which requires approximately 75 W of power for the same light output.

Table 3 shows the measurement results of a 20W low-pressure mercury vapor human discharge lamp containing a filler and a luminescent coating, and a 20W low-pressure mercury vapor human discharge lamp that is structurally similar but without a filler.

The discharge lamp according to the present invention was filled with 96 square meters of tungsten wool having a thickness of 15 microns.

Both discharge lamps were filled with a gas mixture of 72 volumes of neon and 28 volumes of helium and 4 torr (WmHg) of mercury.
).

As is clear from this table, the efficiency of a discharge lamp with the required ballasts connected in series and filled with tungsten wool is 2.
5% higher.

In the case of this discharge lamp, the average per 1 d of volume is 9.8
A tungsten wool body of X10 ■ was present.

Table V shows the measurement results of a low pressure N-IJ steam discharge lamp according to the invention (FIG. 4) having a U-shaped discharge tube in the outer vessel and having a power of 35 W.

Gehlenite glass wool with a thickness of 15μ and resistant to the action of sodium (British Patent No. 1,204,67
0) was filled into the discharge space.

This discharge lamp was compared with a low pressure sodium vapor discharge lamp of the same construction but without a filler, and the results are shown in Table V.

As is clear from this table (2), the light output per unit volume of the low-pressure sodium vapor human discharge lamp according to the present invention is equal to the light output per unit volume of the discharge lamp with the same power but not filled with glass wool of gauze. be larger than the output.

Table 1 also shows that the efficiency of the discharge lamp according to the invention is increased.

Furthermore, the efficiency of a discharge lamp with the required ballast connected in series is 37
It was confirmed that there was only a % improvement.

This is also due to the fact that the current strength is rather low.

In the case of this discharge lamp according to the invention, an average of 1.25×10 rIT9 of Gehlenite glass wool was present per mA of the discharge space.

The discharge lamps with lightly shaped fillings whose data are shown in Tables 1 to establish.

In this case, V/l<7 (where V is the operating voltage (volts)
where l is the distance between the electrodes (crrL)), the ratio between the effective power supplied to the discharge lamp and the loss in the power supply device can be easily set to a suitable value.

In the average tubular discharge lamp according to the invention, the operating voltage divided by the distance between the electrodes is always less than 7.

[Brief explanation of drawings]

FIG. 1 is a diagrammatic cross-sectional view showing an example of a low-pressure mercury vapor human discharge lamp according to the present invention provided with a luminescent coating, and FIG.
Diagrammatic sectional view illustrating an example of a low-pressure mercury vapor human discharge lamp for ultraviolet radiation according to the present invention, which does not have two continuous aggregates;
The figure is a schematic cross-sectional view showing an example of a low-pressure mercury vapor human discharge lamp according to the present invention curved in a U-shape, and FIG. 4 is a schematic cross-sectional view showing an example of a low-pressure sodium vapor human discharge lamp according to the present invention. It is. 1... Glass container, 2... Luminescent coating,
3, 4, 11, 12... thermionic emission electrode, 5,
6, 15...Glass wool body, 10...
・U-shaped discharge tube, 13... Outer container.

Claims (1)

[Scope of Claims] 1. In a low-pressure gas discharge lamp in which a fibrous solid having a structure that allows gas discharge to pass through is provided in the space between the electrodes, the solid is made of quartz glass wool, Gehlenite glass wool, or tungsten wool. Accordingly, the solid is present over at least 1/2 of the distance between the electrodes and distributed sparsely over the discharge space, and the volume of the portion of the discharge space where the solid is present is 10 mI as an average per unit? Low-pressure gas discharge lamp, characterized in that an amount of said solid is present in the range from 1.25.10 m9 to 1.25.10 m9. 2. In the low pressure gas discharge lamp according to claim 1,
A low-pressure gas discharge lamp characterized in that the solid is metal wool, and the metal wool is coated with an electrically insulating material. 3. In the low pressure gas discharge lamp according to claim 1,
A low-pressure gas discharge lamp characterized in that a luminescent coating is provided on the solid body having a sparse structure. 4. In the low pressure gas discharge lamp according to claim 1,
A low-pressure gas discharge lamp characterized in that the solid body is provided with a coating that reflects effective radiation.