JPS5968161A - Low pressure electric-discharge lamp - Google Patents

Abstract

PURPOSE:To enable instantaneous burning to be performed, and enable a sufficient luminous flux to be obtained instantaneously by adjusting the outer surface area of a non-discharge space formed in an airtight tube to be more than specified times larger than the outer surface area of a discharge space, and using metal vapor as the main discharge matter. CONSTITUTION:A low pressure electric-discharge lamp is constituted of a cylindrical outer tube 1 forming an airtight space, and a cylindrical inner tube 2 which is installed almost in the center of the outer tube 1 and has an axis coinciding with that of the outer tube 1. A pair of electrodes 3 and 3 are installed at the open ends of the inner tube 2. The internal space of the inner tube 2 works as a discharge space (A) and the internal space of the outer tube 1 excluding the space (A) works as a non-discharge space (B). The outer surface area (Sa) of the inner tube 2 forming the space (A), and the outer surface area (Sb) of the outer tube 1 forming the space (B) are adjusted to satisfy the relationship of Sb>=5.Sa. Metal vapor is used as the main discharge (emission) matter.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a completely new low-pressure discharge lamp that has high brightness and provides a large luminous flux.

(Background Art) High-pressure metal vapor discharge lamps such as mercury lamps have been realized and put into practical use as discharge lamps that can provide high luminance and large luminous flux.

However, this type of discharge lamp is designed to operate at high pressure and high 6υ during steady lighting.
As shown in Figure 1, the inside of the tube is at low temperature and low pressure for several minutes after lighting starts, so there is not enough light, which requires a so-called warm-up time (time from 0 to tl in the figure). If you try to turn the lights on immediately after turning them off, you will not be able to restart them due to the high temperature and pressure inside the pipe, and it will take several minutes after the lights go out before you can restart them (L in the same figure).
The disadvantage is that it requires 2 to t3). Furthermore, even when trying to obtain the desired light color and color temperature, it is possible to use TIK that can be used practically.
Since the number of electro-luminescent substances is limited to a few types or less, the light has a specific color to color temperature, and there is also the drawback that it is difficult to design freely. Furthermore, due to the high temperature, general soft glass cannot be used, and expensive quartz glass, polycrystalline alumina tubes, etc. are required, and processing is also expensive.

(Object of the Invention) The present invention has been made to address the above-mentioned drawbacks, and its purpose is to provide a compact, instantaneous light-up lamp with high brightness and large luminous flux, which is based on a completely different principle from conventional discharge lamps. To provide low pressure metal vapor discharge lamps.

(Disclosure of the Invention) The basic configuration of the present invention is shown in FIG. The low-pressure discharge lamp (J) according to the present invention consists of a cylindrical outer tube 1 forming an airtight space, and a concentric cylindrical inner tube 2 disposed approximately at the center of the outer tube 1. Both ends of the inner tube 2 are open, and a pair of electrodes 3, 3 are disposed in both openings, making the inside of the inner tube 2 a discharge space.
The other space inside the outer tube 1 is defined as a non-discharge space B. Then, the outer surface area forming the non-discharge space B, that is, the outer surface area sb of the outer tube 1, is set to sb≧5·Sa with respect to the outer surface area Sa of the inner tube 2, which forms the outer surface area forming the discharge space. ) The substance is a metal vapor.

Note that the shapes of the outer tube 1 and the inner tube 2 do not have to be cylindrical as described above, and the outer tube 1 may have the shape of a current mercury lamp, for example, and the inner tube 2 may be bent. As long as the main discharge can be contained by applying a magnetic field in the same direction as the discharge current, the inner tube 2 may not be provided in practice, and it is sufficient to form a structure that limits the discharge, that is, a discharge space.

Next, the operating principle and effects of this discharge lamp will be explained. First of all, since the discharge lamp according to the present invention is a low-pressure metal vapor discharge as mentioned above, its operating principle is essentially the same as that of a fluorescent lamp. You can also turn on the lights immediately. In addition, since the non-discharge space B-h<extremely wide< (sb≧5・Sa) with respect to the discharge space, and each discharge space A1 B is airtight, the coldest temperature of the metal vapor is within the discharge space. It is sufficiently low compared to the temperature and can maintain a high 90% radiation. In other words, if we change the ratio of non-discharge space B to discharge space (assumed to be B/8), of course Ii
Outer surface 11sa, S of k electric space Δ and non-hk electric space ■3
Although it depends on b and the envelope shape, if these are fixed as typical shapes, the characteristics shown in FIG. 3 can be obtained.

In addition, in the same figure, Goa expresses the surface temperature to the discharge space as '
I'b represents the surface temperature of the non-discharge space B, and Tc represents the ambient temperature.

Therefore, the temperature of the discharge space is lower than that of a single-tube discharge lamp which is only connected to the discharge space. However, since the coldest temperature is regulated by the non-discharge space B, it becomes lower. The difference becomes larger as B/Δ becomes larger. This is effective against lightning when increasing the lamp input and aiming for high brightness and large luminous flux.

Now, taking mercury as a metal vapor as an example, the energy unit diagram of mercury is as shown in Figure 4. In the case of a fluorescent lamp, 254 nm ultraviolet radiation is converted into visible light by a phosphor. There is. In this case, if the phosphor is fixed, the efficiency is determined by the UV radiation efficiency of 254 nm. 254nm
As shown in the fJS5 diagram, the ultraviolet radiation efficiency of
It is well known that rr) is the maximum. Therefore,
As the lamp input increases, the coldest temperature of mercury generally reaches 40
It becomes higher and higher than °C (becomes out of the optimum range).

Therefore, in order to emit a large luminous flux in a compact discharge space as in the present invention, a large input must be input into the narrow discharge space r(1), so the coldest temperature of mercury is In the case of a single tube, the pressure rises to extremely low AI, and in the case of a single tube, the pressure also rises at the same time, resulting in a significant drop in efficiency and deterioration in start-up and final start-up due to increased vapor pressure.However, the discharge lamp according to the present invention Since a relatively large non-discharge space B is provided, the coldest temperature of mercury can be reduced, the temperature can be designed and maintained close to the optimum coldest temperature of mercury, and the ultraviolet radiation efficiency can be made sufficiently high.

Next, the basis for the numerical limitation of ``2, Sh≧5・Sa'' will be explained. The temperature of the outer surface of the heating element is approximately correlated to the outer surface area of the heating element if the amount of heat generated (substantially the discharge power in the invention) in the heat generating portion (discharge space A in the invention) is constant. , the outer surface temperature of non-discharge space B is Tb
If the outer surface area is sb and the ambient temperature is Tc, then
If the non-discharge space (3) is brought close to a vacuum, the temperature rise Δ=rb on the outer surface of the non-discharge space B becomes approximately ΔTl+=“l”b−Tcc<1/Sb.

Therefore, the more people occupy the outer surface area sb of the non-discharge space B, the more the outer surface temperature T b of the non-discharge space 13 becomes the ambient temperature i''
It is close to C; it is close to 1.

In addition, the relationship between discharge space A and non-discharge space B is based on the assumption that the outer surface of non-discharge space B is the new ambient temperature. If the area is surrounded by The outer surface temperature Ta approaches the outer surface temperature of a single tube that is connected only to the discharge space.

In this way, the larger the outer surface area of the non-discharge space B to the discharge space (the larger B/Δ in FIG. 3), the larger the outer surface temperature of the non-discharge space B, 1゛b. If the ambient temperature is 1゛c, the outer surface temperature Ta of the discharge space Δ approaches the outer surface temperature of a single tube that enters the discharge space only (outer surface area Sb of the non-discharge space B)! ; (outer surface area Sa to the discharge space), that is, B/Δ in FIG.
When is 1, it is the opposite limit, and the outer surface temperature 'I''b of the non-discharge space 13 is close to the outer surface temperature of a single tube due to the discharge space Δ, and the outer surface temperature of the h-shaped space is Ta is equal to the sum of the external surface temperature of the single tube, the external surface quality T b of the non-discharge space B, and the quality difference of the ambient temperature C. Then, S b ≧ 5 - When it comes to Sa, the temperature rise in the +'Q tube due to the discharge space Δ is about 115 or less. However, when trying to obtain a compact, high-intensity, and high-output lamp, generally only the discharge space A is used. According to Q'+ tube, the temperature to the discharge space is 100 to several 100 degrees.
It is an extremely high value of C, but sb≧ as shown in
5.Sa, the outer surface temperature Tb of the non-discharge space 13 becomes close to the tube temperature when a single tube is normally installed and used.

Next, the average positive column potential elongation E during discharge maintenance in the discharge space A will be described. The fact that the positive column potential gradient E is ln1 small means that the electron temperature during discharge, that is, the electron energy is large. However, as is well known, in current fluorescent lamps, the positive column potential gradient E is 0.9 to 1. IV /
cm, the lowest energy level (63p2) in the energy level diagram (not shown in Figure 4) is the most excited, and the most excitation is due to 254 nm ultraviolet radiation from that excited level to the bottom level. It is designed to be strong. However, when the positive column potential gradient E is increased to 1.5 V/cm or more, the degree of excitation to higher levels (7-''S, 64D, etc.) increases, and as the ultraviolet radiation at 254 nm and 185 nm increases, the ultraviolet radiation at 546 nm, 436nm,
Visible light emission due to radiation of 405 nm, 577 to 579 nm, etc. will also increase rapidly. This would result in relatively low efficiency in the case of a fluorescent lamp that effectively uses only 254 nm radiation, but it uses a phosphor that uses both 254 nm and 185 nm ultraviolet radiation as an excitation source, and also uses other visible light spectral lines. By using it as is, it is possible to provide a discharge lamp with higher overall efficiency. Moreover, the same effect can be obtained when the force Fmium is used as a metal vapor on the other side. That is, in the energy level diagram shown in FIG.
It is well known that when the positive column potential gradient is on the order of / cm, the UV radiation efficiency of 326 nm and 229 nm from the SP excitation deciles reaches its maximum at about 1 ffl. However, by setting the positive column potential to 1.5 V/cm or more, the excitation to the positive position rapidly increases to t+/I, which is similar to the above-mentioned mercury discharge, resulting in effective light emission. can be accompanied by

FIG. 7 is a simplified diagram showing a different embodiment of the present invention (al is a longitudinal sectional view, (bl is a horizontal sectional view). In a configuration different from the basic configuration described above, one end of the inner tube 2 is in contact with the outer tube 1. The phosphor 4 is made of a rare-earth phosphor with excellent high-temperature properties, e.g. , pink yttrium oxide, green zinc silicate and magnesium aluminate, blue magnesium barium aluminate, etc. are preferably mixed appropriately to obtain the desired light color, and the inner tube 2 is set to 10 degrees or less, Furthermore, the positive column potential gradient E≧1.
The high potential gradient of 5 V/cm is mainly due to well-known configurations that increase the diffusion and recombination of charged particles, such as the inclusion of light rare gases such as neon and helium, the use of thin tubes, and the non-circular shape of the internal 11ji surface. It is desirable to achieve this by

FIG. 8 is a simplified diagram showing still another embodiment of the present invention (8
1 is a longitudinal cross-sectional view, (bl is a cross-sectional view. Example 14
The inner tube 2 is made of ultraviolet-transparent glass, and a pair of electrodes 3, 3
Both ends where are located are closed, an opening 5 is provided in the center of the tube, and a phosphor 4 is coated on the inner surface of the outer tube 1.

(Effects of the Invention) As described above, the present invention provides a non-discharge space B in each airtight discharge space in a tube formed airtight, and the outer surface area sb of the first non-discharge space B is the discharge space. outer surface area Sa
Because it is a low-pressure steam discharge lamp, it is characterized by having a metal vapor as the main discharge material, so it can be lit instantly even though it is a discharge lamp with high brightness and large luminous flux. It is possible to provide a new low-pressure discharge lamp that is completely different from conventional discharge lamps and can provide sufficient luminous flux. Furthermore, since the temperature of the discharge space is several 100° C. at most, there is an additional effect that there is no need to use expensive quartz glass or polycrystalline alumina as the tube material.

[Brief explanation of drawings]

FIG. 1 is a lighting characteristic diagram of a high-pressure metal vapor discharge lamp, and FIG. 2 is a simplified diagram explaining the basic configuration of the present invention.
fbl is a perspective view, FIG. 3 is a temperature characteristic diagram inside the tube of the discharge lamp according to the present invention, FIG. 4 is an energy level diagram of mercury, FIG. 5 is a characteristic diagram showing the 254 nm ultraviolet radiation rate, and FIG. The figure is an energy level diagram of cadmium, and FIG. 7 is a simplified diagram showing different embodiments of the present invention (al is a vertical 1:lli plane view,
bl is a cross-sectional view, FIG. 8 is a simplified diagram showing another embodiment of the present invention, fa+ is a longitudinal cross-sectional view, and (b) is a cross-sectional view. ■...Outer tube, 2 inner tubes, 3...electrode, 4...fluorescent body. Patent Applicant Matsushita Electric Works Co., Ltd. Agent Patent Attorney Toshimaru Takemoto (and 2 others) Figure 1 ("<1)> Figure 3 B/A 41 2 ini 514 4v-011 6t4 Vol. 8 (b) (+2)] - Thread 11 Child i1i J-I Self 7 薯二 (Voluntary 1 City Correction) 114th Edition] November 1, 158 Display 11 total r 157 years Patent side No. 1 [1i0534 No. 2,
Name of the invention (Relationship with (q. , agent

Claims (7)

[Claims] (1) A discharge space and a non-discharge space B each having the same airtight structure are provided in an airtight tube, and the outer surface area sb of the non-discharge space B is set as sb≧5・Sa with respect to the outer surface area Sa to the discharge space. U7, a low-pressure discharge lamp characterized by using metal vapor as the main discharge substance. (2) The low-voltage 1ik electric lamp according to claim 1, wherein the average positive column potential gradient E during discharge maintenance in the discharge space A is E≧1.5V/cm. (3) The low-pressure discharge according to claim 1 or 2, wherein the l-number electric space A is constructed by arranging an inner tube having an opening inside an outer tube forming the non-discharge space B. electric light. (4) The low-pressure discharge lamp according to claim 3, wherein a phosphor mainly composed of a rare earth phosphor is coated on the inner surface of the inner tube. (5) A low-pressure discharge lamp according to claim 3, wherein the inner tube is made of an ultraviolet-transmitting material, and a fluorescent substance is coated on the inner surface of the outer tube. (6) The low-pressure discharge lamp according to claim 3, 4, or 5, wherein the straight line i of the inner tube is 101 or less. (7) The high potential elongation IE of the above E≧1.5V/cm,
The low pressure j according to claims 2 to 6 achieved mainly by increasing the diffusion and recombination of charged particles.
jk electric light.