JPH04129142A - Fluorescent character display tube - Google Patents

Abstract

PURPOSE:To obtain a fluorescent character display tube requiring less power consumption and allowing compact design and manufacture at low cost by forming a slow electron beam excitation phosphor particle layer on an anode base in such a way as to cover an electrode pair and constitute a thin layer. CONSTITUTION:A wiring layer 2 and an insulation layer 3 are formed in sequence on a glass substrate 1. An electrode pair 4 electrically connected to the wiring layer 2 is formed on the insulation layer 3. In addition, a phosphor particle layer 5 comprising slow electron beam excitation phosphor is so applied to cover the electrode pair 4 in the form of a thin layer. An anode base 6 having the aforesaid construction constitutes a vacuum vessel, together with cover glass 7. The phosphor particle layer 5 formed on the anode base 6 as aforementioned, acts as both an electron beam source and a luminous element. It becomes possible, therefore, to make a fluorescent character display tube substantially thin type, requiring less power consumption and allowing manufacture at low cost.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a fluorescent display device, and more particularly to a fluorescent display device that utilizes electron beam excited fluorescence and uses surface conduction electron emission as an electron beam source.

[Conventional technology]

Fluorescent display tubes, which are display devices that emit light from phosphors using electron beams emitted from a hot cathode, are used in a wide range of applications due to their ability to provide high brightness and clear display conditions, as well as their small size, light weight, and ability to be driven at low voltages. It's being used.

As shown in FIG. 4, the structure of the fluorescent display tube is such that a phosphor layer 9 made of a low electron beam excited phosphor is formed on a glass substrate 1. An anode voltage is applied to the phosphor layer 9 from an external terminal 10 via a wiring layer (not shown). A grid electrode 11 for electron beam acceleration and control is installed above the phosphor layer 9. The electron beam is emitted from a filament cathode 12 stretched further above.

The filament cathode 12 usually has a structure in which a thin tungsten wire is coated with a mixed carbonate of barium, strontium, and calcium, and the mixed carbonate is thermally decomposed into an oxide during the manufacturing process of a fluorescent display tube. During operation, the filament cathode 12 is electrically heated to bring the coating surface temperature to 600 to 650° C. and emit thermionic electrons.

[Problem to be solved by the invention]

The problem with this conventional fluorescent display tube using a filament cathode as an electron source is that it consumes a large amount of power to normally heat the filament cathode.

Furthermore, the filament cathode must be stretched at a certain distance from the grid electrode, which impedes miniaturization, and the method of stretching it is complicated, raising manufacturing costs.

SUMMARY OF THE INVENTION An object of the present invention is to provide a fluorescent display tube that consumes less power, can be miniaturized, and is inexpensive.

[Means to solve the problem]

In the fluorescent display device of the present invention, at least one pair of electrodes is formed on an anode substrate constituting a vacuum container, and a layer of low-speed electron beam-excited phosphor particles is formed so as to straddle the pair of electrodes and form a thin layer. It has a structure in which a wiring layer and external terminals are formed and coated to apply a potential to the electrode pair from the outside.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a sectional view of an embodiment of the present invention.

As shown in FIG. 1, a wiring layer 2 made of silver, aluminum, etc. and an insulating layer 3 made of low-melting glass as a main component are successively formed on a glass substrate 1. On the insulating layer 3,
An electrode pair 4 electrically connected to the wiring layer 2 is made of, for example, a mixture of graphite and low-melting glass, or an electrode material such as silver or aluminum. A thin layer of phosphor particle layer 5 made of a slow electron beam-excited phosphor is applied across the electrode pair 4 .

The anode substrate 6 having such a structure constitutes a vacuum container together with the cover glass 7. It is important to make the phosphor particle layer 5 thin. In the light emitting part 8 between the electrode pairs 4, the number of points of contact between the phosphor particles is reduced, and the resistance between the electrodes constituting the electrode pair 4 is reduced. It is necessary to set the number of ohms to several hundred MA.

FIG. 2 is a plan view of essential parts showing the structure of an embodiment of the anode substrate of the present invention.

As shown in FIG. 2, the structure of the anode substrate 6 is an example in which the wiring layers 2 are connected to the electrode pairs 4, and the other end is connected to an external terminal (not shown) to which a potential is applied.

FIG. 3 is a plan view of essential parts showing the structure of another embodiment of the anode substrate of the present invention.

As shown in FIG. 3, the structure of the anode substrate 6 is an example in which the electrode pairs 4 and the phosphor particle layer 5 formed to straddle them are arranged in a matrix.

For example, the wiring layer 2 is connected to every other electrode constituting the electrode pair 4, and the potential is applied to the electrodes in a time-division manner so that a current flows through the phosphor layer corresponding to a predetermined electrode pair 4. Luminescence is obtained.

In this embodiment, the phosphor particle layer 5 is in contact with the electrode pair 4 in a relatively high resistance state. For example, 50
When a potential of 100 V to 100 V is applied, surface conduction electron discharge development occurs in the phosphor particle layer 5, as is generally well known.
occurs in Surface conduction electron emission occurs efficiently when the conductive oxide film such as tin oxide, indium oxide, titanium oxide, etc., and the phosphor particle layer 5 have a resistance value of Ω to several hundred MA. In the structure of this embodiment, IOKΩ to 1
High electron emission efficiency was obtained at 00 MΩ.

The emitted electrons enter the phosphor particle layer 5 itself, causing electron beam excitation to emit light. As the phosphor, a slow electron beam excited phosphor that is normally used for fluorescent display tubes can be used, but if a self-activating zinc oxide phosphor is used, which has the highest luminous efficiency (approximately 15 JLh/W), High brightness can be obtained.

[Effects of the Invention] As described above, in the fluorescent display device of the present invention, by forming the phosphor particle layer on the anode substrate, the phosphor particle layer plays the role of both an electron beam source and a light emitting element. Compared to conventional fluorescent display tubes that use filament cathodes as electron beam sources,
This has the effect of significantly reducing thickness, lowering power consumption, and reducing manufacturing costs.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of one embodiment of the present invention, FIG. 2 is a plan view of essential parts showing the structure of one embodiment of the anode substrate of the present invention, and FIG. 3 is another embodiment of the anode substrate of the present invention. FIG. 4 is a sectional view of an example of a conventional fluorescent display tube. 161. Glass substrate, 2... Wiring layer, 3... Insulating layer, 4... Electrode pair, 5... Fluorescent particle layer, 6... Anode substrate, 7... Cover glass, 8...・Light emitting part, 9・
... Phosphor layer, 10... External terminal, 11... Grid electrode, 12-1. Filament cathode.

Claims (1)

[Claims] 1. At least one pair of electrodes is formed on an anode substrate constituting a vacuum container, and a layer of low-speed electron beam-excited phosphor particles is formed so as to straddle the pair of electrodes and form a thin layer. What is claimed is: 1. A fluorescent display device having a structure in which a wiring layer and external terminals are formed and coated to apply a potential to the electrode pair from the outside. 2. The fluorescent display device according to claim 1, wherein the resistance between the electrodes constituting the electrode pair has a value of 10KΩ to 100MΩ. 3. The fluorescent display device according to claim 1, wherein the low-speed electron beam-excited phosphor particles are self-activated zinc oxide phosphors.