JPS581962A - Low pressure mercury-vapor discharge lamp - Google Patents

Abstract

PURPOSE:To obtain a low pressure discharge lamp with its improved luminescent eficiency by enclosing a high-speed electron which is lost in a tube wall and making it useful to the excitation of a mercury atom. CONSTITUTION:Since the second and third AC power supplies E2 and E3 are connected to a conductive coat 11 (generically named as a conductive cylindrical body 12 hereafter) through diodes D2 and D3 so as to form such polarities to the main power supply E1 as shown in the figure, the conductive cylindrical body 12 is always set to more negative potential than the cathode end potential when a fluorescent lamp is lit using a stabilizer L and a glow starter G. Therefore, an intra-tube electrode which is diffused toward a tube wall bounces off the negatively biased conductive cylindrical body 12 and is finally enclosed in tube. As a result, since a high-speed electron with 4.89eV or more energy that is effective for the luminescence of a fluorescent lamp can also be enclosed in the tube and can prevent the conventional loss of the high-speed electron being lost in the tube wall and no contributing to its luminescence, the luminescent efficiency of the fluorescent lamp can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a low-pressure mercury vapor discharge lamp (hereinafter abbreviated as low-pressure discharge lamp), such as a fluorescent lamp.

As shown in Fig. 1, a conventional low-pressure discharge lamp is a type of low-pressure discharge lamp, in which a glass tube 1 is coated with a thin light material 2 on the inner surface, and a stem 3 is sealed at both ends of the glass tube 1. Electrodes are formed by applying MK electron radioactive material (filamen supported by lead wires 4). # on both ends of the glass tube l
i! A cap 7 having a cap bottle 6 for a book is provided.

The discharge space 8 inside the glass tube 1 is filled with mercury particles and a predetermined amount of rare gas such as argon gas after the evacuation and vacuum processes.

To explain the operation of such a conventional fluorescent lamp, accelerated electrons in the tube collide with mercury atoms, and the mercury atoms are excited.
When the mercury atoms in this excited state return to a stable ground state, they emit mainly 2M4 nm ultraviolet rays.The phosphor is irradiated with this ultraviolet ray, and the phosphor emits visible light, causing the fluorescent lamp to emit light. do.

To explain the above in more detail, when one of the electrons in the tube with a lugi of 4"...7 or more collides with a mercury atom, the mercury atom is excited to an excitation level of 1P1, and the @"PI level When the mercury atom returns to its ground state, it emits ultraviolet light of 2M4 nm 04''...Even if an electron with energy below V collides with the mercury atom, the internal state of the mercury atom 11i! No change occurs; the energy of the electron only accelerates the mercury atom, and the energy lost by the electron becomes a loss. Therefore, in order to improve the luminous efficiency of a fluorescent lamp, it is more advantageous to have as many high-speed electrons as 4.89 eV or higher.

-In a low-pressure discharge lamp, the charge inside the tube diffuses to the tube wall, where it recombines with ions and is lost. To compensate for this lost charge, K is 10.43 in the tube.
・Mercury atoms collide with some of the high-speed electrons that have an energy of 7 or more, ionizing the mercury and creating a new electric charge. The newly created electrons have low energy, and the high-speed electrons that collide with each other also lose their speed. These slowed-down electrons are again accelerated by the electric field to become high-speed electrons.

Therefore, the electrons that reach the tube wall contribute nothing to the light emission and are a total loss.

The present invention was made in view of the above points, and an object of the present invention is to provide a low-pressure discharge lamp that improves the luminous efficiency of the lamp by confining the high-speed electrons lost at the tube wall to the tube internal pressure and using it to excite mercury atoms. Kihi provides.

Hereinafter, the present invention will be explained based on the illustrated embodiments. FIG. 2 shows an embodiment of the present invention; it is a partially sectional front view, and is different from a conventional fluorescent lamp in that the structure is different from that of a conventional fluorescent lamp. Conductive cylinder 11t
- The point is that the cylinder is used by being electrically connected so that the potential is 4 more negative than the cathode side potential, and the cylinder is made of a conductive material such as stainless steel. In this example, the size of Messi 10 is i~♂
(♂ indicates that the number of minus digits of square b included in one square inch is U). Then, instead of the mesh crystal conductive cylinder, the inner surface of the glass tube vagina is coated with a transparent conductive film U, and the conductive film 11 is lowered from the cathode side potential! It is electrically connected to the negative potential #C'&.

A case in which a fluorescent lamp having such a configuration is used in a circuit as shown in FIG. 4 will be explained.

The conductive cylindrical body and the conductive film 11 (hereinafter collectively referred to as the conductive cylindrical body) have a diode D.

Since the AC power source El*El of the first and Ill is connected to the main power source EIK through Ds so as to have eW characteristics as shown in the figure, the ballast L1 is connected to the glow starter GK.
When the light lamp is turned on, the conductive cylindrical body always has a negative potential compared to the cathode side potential. Therefore, the electrons within the tube that are about to diffuse toward the tube wall are negatively biased and are repelled by the conductive cylindrical wall, and are eventually confined within the tube. Therefore, fk4.1I is effective for emitting light from fluorescent lamps.
High speed electrons with energy over 9eV are also tyF! It is now possible to confine the electrons to 3, which prevents high-speed electrons from being lost at the tube wall and no longer contributes to light emission, which was the case in the past, thereby improving the luminous efficiency of fluorescent lamps. can.

Keio, in the first embodiment, conductive mesh.

The explanation is based on a configuration in which a cylinder 9 or a glass tube W coated with a transparent conductive coating 11 is provided over the entire length of the discharge 9, but is not limited to this, for example, a cathode. Even if it is installed only in the vicinity, the same effect can be obtained.In addition, the lower the pressure of the rare gas sealed in the tube, the smaller the atomic weight of the enclosed rare gas, or the smaller the diameter of the glass tube, the better the luminous efficiency will be. It was confirmed that it does. This will be explained below.

- Every once in a while, a space charge layer is formed in front of the cathode of a fluorescent lamp, which generates a high electric field. Therefore, the electrons emitted from the cathode are accelerated by this high-speed electric field, and the electrons near the cathode are The abundance of fast electrons in the positive column is much larger than the abundance of fast electrons in the positive column. However, as mentioned above, some of these high-speed electrons diffuse into the tube IIK and are lost by recombining with ions through the tube wall.The electrons that reach the tube wall do not contribute to light emission. There is no loss at all, and only near the cathode 11, where there are many high-speed electrons at 411 in the tube,
Set up a conductive cylindrical body biased to a more negative potential than the cathode.
1) Since the highly shielded electrons tend to be lost to the tube wall, they are trapped inside the tube and sent into the sunlight column to increase the water pen atoms and 1.11 swee metal, which are effectively used for light emission). It is possible to improve the conductivity in the same manner as described above, and furthermore, the material used to form the conductive cylindrical body can be saved.

Next, regarding gas pressure, as the pressure of the rare gas sealed in the tube becomes lower, the mean free path of the electrons in the tube increases, so the number of electrons that reach the tube wall increases.

Therefore, the effect of enclosing a conductive cylindrical body biased at a more negative potential than the cathode to confine electrons in the tube is that the pressure of the enclosed rare gas is low, making it more effective in fluorescent lamps. -As the atomic weight of the rare gas sealed in the tube decreases, the mobility of electrons within the tube increases, the mean free path of electrons becomes longer as shown below, and the number of electrons reaching the tube wall increases.

Therefore, the smaller the atomic weight of the enclosed rare gas, the greater the effect of trapping electrons in the tube by enclosing a highly conductive cylindrical body that is biased to a higher potential than the cathode, and the luminous efficiency becomes higher.

[0°C, 1 Torr] Furthermore, regarding the tube diameter, if the type of gas to be filled and the gas pressure are constant and the mean free path of electrons in the tube is constant,
The smaller the tube radius, the greater the number of electrons reaching the tube wall. Therefore, the effect of enclosing a conductive cylindrical body whose essential potential is higher than that of the cathode to confine electrons in the tube becomes larger as the tube diameter becomes smaller, and the luminous efficiency becomes higher.

As described above, it is clear that the present invention, which has been described with reference to fluorescent lamps, can be applied to low-pressure discharge lamps other than fluorescent lamps.

[Brief explanation of the drawing]

Fig. 1 is a partially sectional front view showing a conventional fluorescent lamp;
2 and 3 are partially sectional front views showing one embodiment of the present invention, and FIG. 4 is a lighting circuit diagram of the same discharge lamp. Patent applicant: Matsushita Electric Works Co., Ltd.

Claims (1)

[Claims] (1) A low-pressure water vapor discharge lamp comprising a conductive material biased to a conductive potential from the cathode at least near the main cathode in the tube.