JPH0774941B2 - Driving method for dot matrix fluorescent display tube - Google Patents

Description

The present invention relates to a driving method of a dot matrix fluorescent display tube.

[Conventional technology]

FIG. 3 shows an example of the structure of a dot matrix fluorescent display tube according to the prior art. In the dot matrix fluorescent display tube, a direct heating filament 4 for emitting electrons, a grid 3 for accelerating and blocking electrons emitted from the filament 4, and an anode 2 coated with a phosphor 1 are arranged on a glass substrate 5. is doing. The anode 2 is formed by vapor-depositing aluminum to a thickness of about 1 μm, forming a stripe by a photolithography technique, and then screen-printing the phosphor 1. Lattice 3
Uses a photolithography technique to form a 426 alloy plate into a linear shape having substantially the same pitch as the anode 2. Anode 2 and grid 3
Are arranged so as to be orthogonal to each other, and arbitrary dots are displayed by setting the potentials of the anode 2 and the grid 3 which are orthogonal to each other as the operating potential. The grid 3 other than the operating potential has a blocking potential, and the anode 2 other than the operating potential has a zero potential. Such an operation method is called a simple matrix method. The display is a method of selecting the electrodes of the grid 3 and the anode 2 which are orthogonal to each other,
There is a method of controlling the potentials of the two grid electrodes of the anode 2 to be displayed and the grid 3 sandwiching it. However, with such an electrode structure, it is difficult to display or hide two consecutive anodes 2 for each dot, and a part of the anode 2 adjacent to the anode 2 to be displayed emits light. There is a phenomenon of light emission.

As a conventional method for solving this problem, as shown in FIG.
There is a double matrix method in which the lattice 3 is divided into two groups and the lattice 3 is shifted by a half pitch. The scanning of the double matrix method is performed on the side of the lattice 3 and a positive voltage is sequentially applied to the two adjacent lattices 3a, and the anode between the two lattices 3a is applied.
By applying a positive voltage to 2a, driving scanning is performed and light is emitted. Further, as shown in FIG. 5, there is also a method in which one row of anodes 2 is divided into four groups, and one lattice 3 is arranged with respect to four dots of the anodes 2 to form a quadruple matrix structure.

[Problems to be Solved by the Invention]

In the above-mentioned conventional dot matrix fluorescent display tube, since the anode dots are divided into 2 to 4 blocks in the stripe direction, the wiring of the anode electrodes is complicated, and especially in the case of a quadruple matrix, the dot size The width of the wiring routing region is larger than the size.
When the number of wiring of the anode becomes twice or four times that of the simple matrix structure, the wiring on the glass substrate 5 is required to have high precision and high density, and a manufacturing technique for manufacturing stably so that there is no disconnection or short circuit in all connections. Inspection equipment is required to check this. Further, since the number of terminals of the anode is doubled or quadrupled, the driving circuit is complicated.

In addition, it is possible to manufacture a dot matrix fluorescent display tube of about 480 × 240 dots by a driving method such as a double matrix method or a quadruple matrix method, but it is difficult to produce a larger capacity dot matrix.

[Means for Solving the Problems]

The present invention drives and scans the display of phosphor dots of a dot matrix fluorescent display tube constituted by enclosing a filament, a grid, and an anode coated with dots of phosphor in a vacuum container by applying an anode potential and a grid potential. The method is characterized in that the cut-off potential of the grid adjacent to the grid of the driving / scanning operation potential is 1.5 times or more the normal cut-off potential without complicating the electrode structure or the electrode wiring.

〔Example〕

Next, the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view for explaining the operation of one embodiment of the present invention, and this example is an example in which the phosphor dots 1a of the anode 2 are made to emit light. The electrons emitted from the filament 4 are accelerated to the lattice 3a by the operating potential E _c of the lattice 3a. At this time, the lattice 3c is
Since the blocking potential −E _co and the lattice 3b are applied with a potential −1.5E _{co, which} is 1.5 times the normal blocking potential, the electrons toward the lattices 3b and 3c have a negative potential, and the orbit is bent in the middle. Lattice 3a
The electrons that have passed through are accelerated to the operating potential E _b of the anode 2 and cause the phosphor dot 1a on the anode 2 to emit light midway. The electrons after passing through the lattice 3a try to diffuse in the direction of the phosphor dot 1b centering on the phosphor dot 1a, but due to the potential −1.5E _co 1.5 times the blocking potential of the lattice 3b, the phosphor cannot diffuse. It will be incident on the dot 1a. The potential of the grid 3b needs to be 1.5 times or more the cutoff potential, and if it is less than this, some of the electrons will enter the phosphor dots 1b and light will be leaked.

FIG. 2 is a sectional view for explaining the second embodiment of the present invention. The grid 3 is placed on a grid support 6 installed between the phosphor dots of the anode 2. In this embodiment, since the lattice 3 is supported by the lattice support 6, the distance between the anode 2 and the lattice 3 can always be kept constant and the contact between the anode 2 and the lattice 3 can be prevented. This has the advantages that the cut-off voltage of the grid 3 can be reduced and a large-capacity dot matrix can be manufactured.

〔The invention's effect〕

As described above, according to the present invention, with respect to the application condition of the lattice potential at the time of displaying, the potential of the lattice next to the lattice to be the operating potential is set to 1.5 times or more the normal cutoff potential, so that the lattice and the anode operate. It is possible to cause the potential dots to emit light with a simple electrode structure.

This has the advantages that the manufacturing is simplified, the drive circuit can be made simpler than before, and the large-capacity dot matrix can be easily manufactured.

[Brief description of drawings]

FIG. 1 is a transverse sectional view for explaining the operation of the first embodiment of the present invention, FIG. 2 is a vertical sectional view of the second embodiment of the present invention, and FIG. 3 is a conventional simple matrix type fluorescent display tube. FIG. 4 is a longitudinal sectional view, FIG. 4 is an operation explanatory view of the double matrix system, and FIG. 5 is an operation explanatory view of the quadruple matrix system. 1,1a, 1b …… Phosphor, 2,2a, 2b …… Anode, 3,3a, 3b, 3c
…… Lattice, 4 …… Filament, 5 …… Glass substrate, 6
...... Lattice support.

Claims (1)

[Claims] 1. A dot-matrix fluorescent display tube constructed by enclosing a filament, a grid, and an anode coated with a phosphor in a dot shape in a vacuum container, and driving and scanning the display of phosphor dots by applying an anode potential and a grid potential. In the method described above, the potential of the lattice adjacent to the lattice to which the potential for accelerating the emitted electrons from the filament is applied is
A method for driving a dot matrix fluorescent display tube, which is characterized by applying 1.5 times or more.