JPS62276752A - Low pressure discharge lamp - Google Patents

Abstract

PURPOSE:To make it possible to form a one-side base type lamp, by setting the distance between an anode and a cathode sufficiently smaller than the whole length of a tube body, making the anode side space opposite to the cathode sufficiently wide, and exercising the negative resistance discharge between the anode and the cathode. CONSTITUTION:At one end of a tube body 8, a cathode 11 for electron emission and an opening anode 12 of a mesh form or ring form are furnished closely positioned, the distance between the anode and the cathode is set much smaller than the whole length of the tube body, and the anode side space opposite to the cathode is made large enough. In the tube body, a small amount of luminous radiating gas is sealed to make the pressure at the operation time mm Torr, and the negative resistance discharge is exercised between the anode 12 and the cathode 11. By applying a voltage to the anode 12 through a stabilizing resistance 14 while heating the anode 12 with a DC power source 13, the electrons are radiated and accelerated sufficiently, the majority of them penetrate into the broad rear space of the anode 12, because the anode is an opening type, strike to the luminous radiating gas 10 of mercury, and are excited and ionized to produce the radiation.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention [Technical Field] The present invention relates to a low-pressure discharge lamp having a single-cap configuration.

[Technology on the back] Lamps suitable for use in large displays, decorative displays, etc. include a fluorescent lamp 2 lit using a high-frequency inverter 1 as shown in Figure 18, and a CRT single tube as shown in Figure 2. 3, but the fluorescent lamp 2 in Figure 1
Since the electrodes are originally located at both ends and should have a double-cap structure, they are forcibly bent, making the process complicated and expensive, making it difficult to downsize, and creating the desired light distribution that is unreasonable and wasteful. In addition, since the discharge is similar to that of conventional fluorescent lamps, there are drawbacks such as high starting voltage and discharge sustaining voltage.

In addition, in the conventional example shown in FIG.
It is necessary to apply a high voltage between the grids 7 and 7.
The structure is complicated and the cost is high due to the provision of a phosphor, and the luminous efficiency from the four phosphor surfaces is relatively low.

Moreover, if the electrode is small, the response is poor due to heat radiation, and furthermore, the efficiency is low and the life span is short.

[Object of the Invention] The present invention has been made in view of the above-mentioned problems, and its purpose is to essentially have a single-cap structure, to have a simple structure, and to be driven with a low power supply voltage. An object of the present invention is to provide a low-pressure discharge lamp that can emit light with high brightness.

[Disclosure of the Invention] The present invention arranges an electron-emitting can and a mesh-shaped or ring-shaped opening anode close to each other at one end of a tube, and the distance between the anode and the cathode is set in such a way that the distance between the anode and the cathode is The space on the side opposite to the cathode of the anode is set to be sufficiently small, and the space on the side opposite to the cathode of the anode is made sufficiently large, and a small amount of light emitting gas is sealed in the tube so that the pressure is several mmTorr during operation. The tR1 invention is a low-pressure discharge lamp that is characterized by producing a static resistance discharge, and an electron-emitting cathode and a mesh-shaped or ring-shaped opening anode are arranged close to each other at one end of the tube body. The distance between the tubes is set to be sufficiently small compared to the total length of the tube, and the space on the opposite side of the anode to the cathode is made sufficiently wide, so that a trace amount of light is kept inside the tube so that the pressure is several mm'l'orr during operation. The released gas is sealed, and a static magnetic field is applied to the outside of one end of the tube on the cathode side in a direction approximately parallel to the M1 field between the cathode and the anode, creating a negative resistance discharge between the anode and the cathode. The present invention provides a low-pressure discharge lamp characterized in that an electron-emitting cathode and a mesh-shaped or ring-shaped opening anode are arranged close to each other at one end of a tube, and a gap between the anode and the cathode is provided. The distance is set sufficiently small compared to the total length of the tube, and the space on the anti-cathode side of 7/-1' is made sufficiently wide, and a small amount of light emitting gas is introduced into the tube so that the pressure is 10III Torr during operation. magnets are placed outside one end of the tubular body on the cathode side and outside the other end of the tubular body on the opposite side so that the polarities are opposite to each other, and a negative resistance discharge is caused between the anode and the cathode. The third aspect of the present invention is a low-pressure discharge lamp characterized by the following, and will be explained below with reference to Examples.

Fig. 1j1-PIS1 shows a basic embodiment of the first invention, and this embodiment uses a light-transmitting tube 8 with a short and thick columnar outer shape, and the inner circumferential surface of the tube 8 is and phosphor 9 on the inner ceiling surface.
At the same time, a light emitting gas 10, such as water, is sealed to a degree of rll, mmTorr, and a cathode 11 and an anode 12 are placed close to each other at the bottom, which is one end of the tube 8.

The cathode 11 is for electron emission and is a directly heated or indirectly heated thermionic emitter cathode. Here, compared to ordinary fluorescent lamps, there is no practical risk and the vacuum is close to that, so impregnated cathodes and BI (Bariu+o InteFi
A cathode that is resistant to vacuum evaporation, such as a rated) cathode, is optimal.

The anode 12 uses a mesh-shaped (or ring-shaped) open-type anode, and this anode 12 and cathode 1
The distance aa from 1 is chosen to be in a comparable relationship with the mean free path λ of the electron, and the relationship is such that the number λ≧α≧a fraction of a person.

Thus, while heating the cathode 11 using the DC power supply 13, a voltage is applied to the anode 12 via the stabilizing resistor 14, and the voltage (10-odd V) at which discharge occurs between the anode 12 and the cathode 11 is increased. When this happens, the space charge near the cathode 11 is neutralized, so that electrons are sufficiently emitted and accelerated to an energy comparable to the anode voltage. Here, since the anode 12 is an open-type anode, most of the electrons penetrate into the wide space behind the anode 12. In the back space, the electrons collide with the light-emitting gas 10 made of mercury to cause excitation and ionization, resulting in light emission. The ultraviolet rays generated by this emission hit the phosphor 9 and transmit visible light to the tube 8.
release it outside. Of course, if the phosphor 9 is not applied, ultraviolet rays will be emitted. By the way, since the dimensions of the tube body 8 are about several to ten times as large as the mean free path of electrons, electrons can be sufficiently diffused in areas other than between the shield 11 and the anode 12, and sufficient light can be emitted in the space behind the tube. Become.

By the way, in this embodiment, the emission of electrons from the cathode 11 is made sufficient, and the voltage applied to the anode 12 is set to several 1.
By setting the voltage to 0V, the discharge between the anode 12 becomes a negative resistance discharge, the ionization (therefore, excitation) multiplication effect is large, the ionization (wh generation) efficiency is improved, and the luminous efficiency is increased as a result. In addition, sufficient discharge and ionization result in sufficient ions to be generated, which further effectively neutralizes the space charge near the cathode 11, creates an ion sheath in the cathode 11, and efficiently emits electrons. Furthermore, since the ions rush into the cathode 11, the cathode 11 is effectively heated, and as a result, the function of the cathode 11 can be efficiently performed with less electric power. Further, since a sufficient current can flow, high-intensity light emission can be obtained, and since the lamp voltage does not increase even with an increase in input, the DC power supply 13 can be a low-voltage power supply.

Figure 2 shows the current-voltage characteristics of this example, and Figure 3 shows a comparison between this example (a) and a conventional general fluorescent lamp (b). Required power supply voltage b
, operating voltage C is those of the conventional example a', 13゛, C
It can be seen that it is lower than ゛.

Figure 4 shows the second embodiment, in which the tube body 8 of the lamp of this embodiment consists of a cylindrical bulb with a diameter of about 301 mm and a length of about 50 m, and the anode 12 consists of a ring-shaped nickel electrode. The cathode 11 is an indirectly heated barium-impregnated cathode. There is several mmT inside the tube body 8 during operation.
Several to several tens of ag of mercury is sealed as a light emitting gas 10 so that the amount of mercury is about 100. is used. Thus, in the lamp of this example, the lamp voltage was about 20 V, the lamp power was about 5 W, the luminous flux was about 150 Qm, and the luminance of the space behind the anode 12 was about 10,000 Cd/m2.

The lighting circuit uses a transistor constant current/switching circuit, and controls the transistor 'rr so that the current set by the Zener diode ZD and the resistor R flows through the terminal. The light can also be controlled by changing the duty, amplitude, etc. 15 in the figure is the filament 16
It is a power source for heating.

In the above embodiment, the phosphor 9 is coated on the inner ceiling surface and the inner circumferential surface, but since the light emitting surface for a display only needs to be the ceiling surface, it is also possible to apply the phosphor 9 only on the inner ceiling surface. .

1. This example is an example of the second invention in which the brightness and luminous efficiency are improved by -m compared to the above example. In this example, as shown in FIG. Turn the surface to tube 8
A ring-shaped cathode is used as the anode 12. On the outside of one end of the tube body 1 close to the cathode 11, there is a wire approximately parallel to the electric field between the cathode 11 and the anode 12. Magnets 17 made of permanent magnets or electromagnets are closely arranged to apply a static magnetic field in the direction.

The electrons coming out of the cathode 11 and penetrating the anode 12 are subjected to a force due to the magnetic field, and the magnetic force 1/Q is shown in FIG.
Rotate around x. In other words, in addition to the electric force due to the original electric field, the force due to the magnetic field is added, and as a result, it moves in the form of a so-called magnetic line of force trap in which it wraps around the magnetic force #iX. Therefore, as a result, the place where the magnetic field line × is strong, that is, the 6th
Electrons gather in the center of the tube 8 and near the magnet 17 shown in the figure, resulting in strong light emission, and as shown in FIG. There is no. Furthermore, since the movement of the electrons is a small circular motion around the magnetic field lines as shown in Figure 8, the mean free path appears to be smaller than in the case of no magnetic field as shown in Figure 9. This increases the chances of collision and excitation of the light emitting gas 10 made of mercury.

In other words, the excitation efficiency of each electron increases, and the overall luminous efficiency improves.

Next, the state of electrons passing through the anode 12 is compared with the state of the electrons passing through the anode 12 when there is no magnetic field as in the first embodiment. In other words, without a magnetic field, the electron energy near the potential of the anode 12 as shown in Fig. 10 is obtained on average as shown in Fig. 12, but in the presence of a magnetic field, as shown in Fig. Since the energy is mainly determined by the spatially distributed potential,
The energy is lower than that without a magnetic field as shown in FIG. 13, and as a result, it approaches 5 to 10 eV, which is desirable for excitation of ultraviolet 254na+, and improves luminous efficiency.

As described above, in this embodiment, the effects of improving the luminance of light emitted in a specific direction and improving the light emitting efficiency by applying a static magnetic field are added to the effects of utilizing negative characteristics. The strength of the magnetic field generated by the magnet 17 is determined by adjusting the Larmor radius of electrons near the anode 12 in the tube 8 to several tens of meters + * (for example, 0.1 ma).
+~0. The magnetic field strength is set to 3 mm).

and m The tube 8 in each of the above embodiments was a short cylindrical tube,
In this embodiment, even a thin straight tube 8 is sufficient to cover the entire body 9.
This is an embodiment corresponding to the third invention that realizes a single-base lamp with high efficiency of emitting light.

In this embodiment, as shown in FIG.
A cathode 11 and a mesh-shaped or ring-shaped Sekiguchi-type anode 12 are arranged at one end, and magnets 17a and 17b made of permanent magnets or electromagnets are closely arranged on the outside of both ends of the tube body 8. There is. A phosphor 9 is coated on the inner peripheral surface of the tube 8 corresponding to the space behind the anode 12, and a light emitting gas 10 made of mercury is sealed so that the pressure inside the tube is approximately several m+a Torr during operation.

The polarity of the opposing magnets 17a and 17b is set to +A pole.

However, in this example, as shown in tls 151
The anode 12 is rotated while wrapping around the anode 12.
It will move in the space behind the. As a result, the anode 12 collides with the light-emitting gas 1° made of mercury during the movement and is excited to emit light, so that the light is emitted substantially uniformly over the entire space behind the anode 12, as shown in FIG. 15(m). The difference from Embodiment 3 is that Embodiment 3 has a magnet 17 on the cathode 11 side, and the magnetic force i
Since x is distributed in the diffusion direction, the light emitted spreads out in a fan shape in the space behind the anode 12, but in this embodiment, the magnetic force # Electrons are trapped and emit light uniformly. It's a lot,
The strength of the magnetic field generated by the magnets 17ar17b is determined when the Larmor radius of electrons near the anode in the tube is 0. Several to several tens of mm (
For example, the magnetic field strength is set to 0.1a+m-0.3ml1).

[1 random Σ This embodiment is a modification of the fourth embodiment, and the magnets 17a, 17
By weakening the magnetic field strength of b, the magnetic force Mx is increased as shown in Fig. 17.
This widens the distribution of the particles and makes it possible to use a rough ball-shaped tube body for the tube body 8.

Although the light emitting gas 10 in each of the above embodiments is mercury, it may be a light emitting gas such as sodium or cesium.

[Effects of the Invention] The first invention arranges an electron-emitting cathode and a mesh-shaped or ring-shaped opening anode close to each other at one end of a tube, and the distance between these anodes and the cathode is set to be sufficient compared to the entire length of the tube. In addition, the anti-cathode I space of the anode is set to be a sufficiently wide space, and a small amount of light emitting gas is sealed in the tube so that the operating pressure is 1 mm Torr, and a negative resistance discharge is created between the anode and the cathode. As a result, light can be emitted in the space behind the anode, making it possible to realize a single-ended lamp in which the anode and cathode are placed at one end of the tube. Because the pressure inside the body is low pressure of only the light emitting gas, the electric power i1i is low! It is possible to start and maintain lighting with voltage, and because it operates with negative resistance characteristics, the efficiency of the cathode function is high, and high brightness and low lamp voltage can be maintained. Because of this, the light emission can be easily and quickly turned on and off by turning on and off the anode voltage, and therefore it can be applied to displays, etc., and the structure is simple, so the cost is low. applies a static magnetic field to the outside of one end of the tube on the cathode side in a direction approximately parallel to the electric field between the cathode and the anode, making it possible to make electrons rotate along the lines of magnetic force, causing them to move in a specific direction. In addition to the effects of the first invention, the third invention has the effect of improving the luminous brightness and luminous efficiency of the tube on the cathode side.
4. Magnets are placed outside the other end of the tube on the opposite side so that their polarities are opposite to each other, so even if the tube is long, electrons can be moved between the ends of the tube without being diffused. This makes it possible to emit light uniformly even if the space behind the anode is good, and by forming a magnetic field that matches the shape of the tube with the magnets at both ends, it is also possible to make the entire tube emit light uniformly. This effect is achieved together with the effect of the first invention.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of Example 1 corresponding to the first invention, FIGS. 2 and 3 are diagrams explaining the operating characteristics of the same as above, FIG. 4 is a schematic configuration diagram of Example 2 of the same as above, and FIG. is a schematic configuration diagram of the third embodiment corresponding to the second invention, and FIGS. 6 to 13 are the same as the above embodiment 3.
An explanatory diagram of the operation, [Figure 14 is Embodiment 4 corresponding to the third invention]
15 to 16 are operation explanatory diagrams of the fourth embodiment, FIG. 17 is a schematic diagram of the fifth embodiment, and FIGS. 18 and 19 are schematic diagrams of the conventional examples. 8
is a tube, 10 is a light emitting gas, 11 is a cathode, 12 is an anode, and 17=17a, 17b are magnets. Agent Patent Attorney Ishi 1) Ai 7 Figure 1 Figure 2 Figure 77' Figure 3 Figure 4 Figure 5 Figure 9 Figure 11 Figure 15 Figure 17

Claims (6)

[Claims] (1) An electron-emitting cathode and a mesh-shaped or ring-shaped opening anode are arranged close to each other at one end of the tube, and the distance between these anodes and the cathode is set to be sufficiently small compared to the overall length of the tube, and the anode The space on the side opposite to the cathode is made sufficiently large, and a small amount of light-emitting gas is sealed inside the tube so that the pressure is several mmTorr during operation, and a negative resistance discharge is generated between the anode and cathode. A low pressure discharge lamp. (2) The low-pressure discharge lamp according to claim 1, wherein the light-emitting gas is mercury. (3) An electron-emitting cathode and a mesh-shaped or ring-shaped opening anode are arranged close to each other at one end of the tube, and the distance between these anodes and the cathode is set to be sufficiently small compared to the entire length of the tube, and the anode The space on the anti-cathode side of the tube is made sufficiently large, and a small amount of light emitting gas is sealed inside the tube so that the pressure is several mmTorr during operation. 1. A low-pressure discharge lamp characterized in that a static magnetic field is applied in a direction substantially parallel to an electric field to cause negative resistance discharge between an anode and a cathode. (4) The strength of the static magnetic field is determined by the Larmor radius of electrons near the anode inside the tube being 0. The low-pressure discharge lamp according to claim 3, characterized in that the magnetic field strength is several to several tens of millimeters. (5) An electron-emitting cathode and a mesh-shaped or ring-shaped opening anode are arranged close to each other at one end of the tube, and the distance between these anodes and the cathode is set sufficiently small compared to the entire length of the tube, and the anode The space on the anti-cathode side of the tube is made sufficiently large, and a small amount of light emitting gas is sealed inside the tube so that the pressure is several mm Torr during operation. A low-pressure discharge lamp characterized in that magnets are arranged outside the end so that their polarities are opposite to each other, and negative resistance discharge is caused between an anode and a cathode. (6) The strength of the magnetic field of the above magnet is determined by the Larmor radius of electrons near the anode inside the tube. The low-pressure discharge lamp according to claim 5, characterized in that the magnetic field strength is several to several tens of millimeters.