JPH0384844A - Luminous radiation electron tube - Google Patents

Abstract

PURPOSE:To simplify light adjusting control of a luminous radiation electron tube, reduce the cost of a lighting circuit for the electron tube and enhance the emission efficiency of the tube by causing the tube to emit light using a negative glow plasma comprising a pair of discharge electrodes arranged opposite to each other with a space of several mm to several cm between them, in a bulb body. CONSTITUTION:In a translucent spherical bulb body 1 having a discharge gas consisting of mercury vapor and rare gas sealed therein, a pair of discharge electrodes 2 are arranged opposite to each other with a space of several mm to several cm between them and a reflection film 4 is formed on the inner face of the backside portion of the bulb body 1 including that of a neck portion 1a where the extending portion 3 of both discharge electrodes 2 is formed. Also phosphor 5 is applied to the whole inner surface of the bulb body 1. Both discharge electrodes 2 are used as filaments for emitting thermions and a starter is connected between respective ends of both filaments 2 and AC supply is applied between the other ends of both filaments 2 via a pressure relief element so that the electron tube is lighted. Thus a luminous radiation electron tube having good light emission efficiency and including a simple, low-cost lighting circuit is obtained while its light adjusting control is facilitated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a photoelectron emission tube used in a large display device.

[Prior Art] Conventionally, as a light emitting element used in a large display device,
U-shaped fluorescent lamp, three-color integrated fluorescent lamp (ceramic bottom type),
Incandescent lamps equipped with color filters were used.

[Problems to be Solved by the Invention] However, when a U-shaped fluorescent lamp or a three-color integrated fluorescent lamp is used, although the luminous efficiency is good, there is a problem in that dimming control is difficult. That is, when phase control is simply performed, the limit is dimming of about 60% of the total luminous flux, and there is a problem in that dimming control of 64 gradations cannot be performed.

Therefore, "duty control" is used to change the on/off time of fluorescent lamps, but once fluorescent lamps are turned off, they will not start unless a high kick voltage is applied. However, in order to lower the kick voltage, a circuit that constantly heats the filament is required, resulting in a complicated circuit configuration and increased circuit loss. In addition, the lamp voltage V1a after lighting becomes as shown in Figure 7, and requires a voltage with a steep rise and high peak as the restriking voltage, and although the effective value is not high, it supplies more than the restriking voltage. There was a problem in that circuit loss increased because of the need to do so.

On the other hand, when incandescent lamps equipped with color filters are used, they have short lifespans, poor luminous efficiency, differ greatly in luminous efficiency depending on the color, and the lighting circuit becomes complex and expensive. There was a problem.

The present invention has been made in view of the above points, and its purpose is to provide a light-emitting electron tube that can easily control dimming, has good luminous efficiency, has a simple lighting circuit, and is inexpensive. There is a particular thing.

[Handle for Solving the Problems] The light-emitting electron tube of the present invention has a light-transmitting spherical tube in which a discharge gas consisting of mercury vapor and a rare gas is sealed, and the facing distance is several mm to several cm. A pair of tribes 1! A reflective film is formed on the inner surface of the back part of the tube where the electrodes are arranged and the lead-out portions of both discharge electrodes are formed, and a phosphor is coated on the entire inner surface of the tube.

[Function] The present invention is constructed as described above, and includes a pair of opposing spacings of several mm to several cm in a translucent spherical tube filled with a discharge gas consisting of mercury vapor and a rare gas. Since it is a light-emitting electron tube that uses negative glow plasma with discharge electrodes arranged to emit light, dimming control is easy, and the lighting circuit is simple and inexpensive.

In addition, a reflective film is formed on the inner surface of the back part of the tube where the lead-out parts of both discharge electrodes are formed, so the light emitted from the phosphor inside the tube is reflected forward and used effectively. This makes it possible to improve luminous efficiency.

[Example] Figures 1 and 2 show an example of the present invention, in which a transparent tube is filled with a discharge gas consisting of mercury vapor and a rare gas (argon gas of several Torr is used in the example). A pair of discharge electrodes 2 facing each other with an interval of several mm to several cm are arranged in a spherical tube body 1 having a magnetic field, and a lead-out portion 3 of both discharge electrodes 2 is arranged.
A reflective film 4 is formed on the inner surface of the back portion of the tube body 1, including the neck portion 1a, and a phosphor 5 is coated on the entire inner surface of the tube body 1. In the example, both discharge electrodes 2
is a filament that emits thermionic electrons (referred to as filament 2), and a starter is connected between one end of both filaments 2, and an alternating current power is applied between the other ends of both filaments 2 via a step-down element made of a capacitor. It is lit up by this.

The operation of the embodiment will be described below. Now, the filament 2 is heated by the starter that is turned on at the time of starting.
When a predetermined voltage is applied to both heated filaments 2fi via a step-down element made of a capacitor, electrons emitted from the filament 2, which becomes the cathode, are accelerated toward the filament 2, which becomes the anode, and the filament 2
The electron flow passing through ionizes and excites the discharge gas. A low-pressure gas mixture of mercury vapor and rare gas is used as the discharge gas, and when the discharge gas is excited by the electron flow, it emits ultraviolet rays, which are converted by the phosphor 5 into visible light. In the case of this light emitting electron tube, the lighting maintenance voltage is low (20V>,
Moreover, a high kick voltage for starting is unnecessary, and relatively high luminous efficiency can be obtained. The luminous efficiency of a light-emitting electron tube without a reflective film is approximately 331 m/W, which is significantly better than an incandescent lamp, but it is still lower than the luminous efficiency of a conventional spherical fluorescent lamp (40 to 50 lea/W). ) is slightly lower than that of In this embodiment, since the reflective film 4 is provided on the inner surface of the back part of the tube body 1, the light emitted inward from the phosphor 5 is reflected as shown in FIG. membrane 4
As a result, the light is reflected forward and used effectively, increasing the amount of light emitted forward and achieving a luminous efficiency comparable to that of conventional fluorescent lamps. Furthermore, the light-emitting electron tube of the embodiment does not require a kick voltage at the time of starting, the lamp voltage Vfa at the time of lighting is low, and furthermore, the lamp voltage Vh has no restriking voltage as shown in FIG. Therefore, compared to the case of fluorescent lamps, the circuit configuration of the lighting circuit is simpler and cheaper, and the circuit loss can be reduced.

FIG. 5 is an explanatory diagram showing the method of forming reflection H4, and shows the method for forming reflection H4.
As shown in FIG. 5(a), the opening of the neck portion 1a of the tubular body 1 is immersed in a slurry 7 of titanium oxide T i O filled in the interior of the tubular body 1, and the air inside the tubular body 1 is drained through the vibrator 8. By drawing out the air, the slurry 7 is allowed to penetrate to a predetermined height as shown in FIG. 5(b) due to the pressure difference, and by blowing air into the back of the tube body 1, as shown in FIG. A reflective film 4 is selectively applied to the inner surface of the portion.

FIG. 6 is an explanatory diagram showing another method of forming the reflection M4,
The reflective film 4 is selectively formed on the inner surface of the back part of the tube body 1 by vapor deposition (the front part is shielded using the shade 10), and in the embodiment, molybdenum Mo is used as the vapor deposited metal. Tungsten W, which has a high melting point, is used as the column 9 which also serves as an electrode for passing a current through.In the example, the outer diameter of the spherical part of the tube body 1 is 20 m.
m.

[Effects of the Invention] The present invention is configured as described above, and includes a pair of spherical tubes having an opposing distance of several mm to several cm in a translucent spherical tube filled with a discharge gas consisting of mercury vapor and a rare gas. Since this is a light-emitting electron tube that uses negative glow plasma in which discharge electrodes are arranged to emit light, dimming control can be easily performed, and the lighting circuit can be made simple and inexpensive.

In addition, a reflective film is formed on the inner surface of the back part of the tube where the lead-out parts of both discharge electrodes are formed, so the light emitted from the phosphor inside the tube is reflected forward and used effectively. This has the effect of improving luminous efficiency.

[Brief explanation of drawings]

FIG. 1 is a sectional view of an embodiment of the present invention, FIG. 2 is a partially cutaway perspective view of the same, and FIGS. 3 and 4 are explanatory diagrams of the same operation.
Figures 5 and 6 are explanatory diagrams of the method of forming a reflective film, Figure 7
The figure is an explanatory diagram of the operation of a conventional example. 1 is a tube body, 2 is a discharge electrode, 3 is a lead-out portion, 4 is a reflective film, and 5 is a phosphor.

Claims (1)

[Claims] (1) A light-transmitting spherical tube filled with a discharge gas consisting of mercury vapor and a rare gas, with opposing intervals of several mm to
A pair of discharge electrodes several centimeters in length are arranged, and a reflective film is formed on the inner surface of the back part of the tube, where the extension parts of both discharge electrodes are formed, and a phosphor is coated on the entire inner surface of the tube. A light emitting electron tube.