JPH02256143A - Matrix fluorescent character display tube - Google Patents

Abstract

PURPOSE:To emit the light with the uniform luminance by locating a grid electrode and a cathode filament and an anode common electrode which consists of anode electrodes provided continuously in parallel with each other, and applying the voltage to both ends of these electrodes. CONSTITUTION:A grid electrode 8 which both ends resistors are formed at the same value in outline, a cathode filament 7 and an anode common electrode 9 which consists of anode electrodes 13 provided continuously are located in parallel with each other, and the voltage is applied to both ends of the cathode filament 7, the grid electrode 8 and the anode common electrode 9. Consequently, level differences of the voltage between the cathode filament 7 and the grid electrode 8 and each anode electrode are the same, and electrons to be inducted from the cathode filament T to the anode electrodes 13 by the grid electrode 8 are unified. A matrix fluorescent character display tube 6 with the uniform light emitting luminance and without the nonuniformity can be thus obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a matrix fluorescent display tube used as a self-luminous display device.

2. Description of the Related Art Fluorescent display tubes are one type of display device that has been developed in recent years. This is a device in which a cathode filament, a grid electrode, and an anode electrode are arranged facing each other in sequence.
This is a display device that utilizes the fact that electrons emitted from a cathode filament and guided to a grid electrode emit light when they collide with the fluorescent material of the anode electrode. Currently, there is a demand for direct current driving of the cathode filament of a fluorescent display tube due to the need for in-vehicle use.

However, in this case, a level difference corresponding to the applied voltage occurs between both ends of the cathode filament, which tends to cause unevenness in the luminance of the fluorescent display tube.

In order to correct such brightness deviations, there is a matrix type fluorescent display tube in which the cathode filament is inclined with respect to the grid electrode and the anode electrode.

Therefore, such a fluorescent display tube will be explained as a conventional example with reference to FIG. As mentioned above, this fluorescent display tube
Here, an anode electrode 3 made of a fluorescent material is formed in a matrix on the second side of a glass substrate 2, and a grid electrode 4 made of a metal mesh and an inclined cathode filament 5 are sequentially arranged on this anode electrode 3.

In such a configuration, the polarity of the DC voltage Ea applied to both ends of the cathode filament 5 is 10 on the side where the cathode filament 5 is close to the electric current 4f13.4, and - on the side where the cathode filament 5 is separated from the electric current 4f13.4.

Problems to be Solved by the Invention The fluorescent display tube 1 as described above has a cathode filament 5.
By slanting , brightness unevenness due to level difference of DC voltage Ea is corrected. However, the slope of the cathode filament 5 must be set in advance in accordance with the level difference of the DC voltage Ea, which makes the design and manufacture of the fluorescent display tube 1 difficult. Furthermore, since the slope of the cathode filament 5 is constant and fluctuations in the DC voltage Ea cause uneven brightness in the fluorescent display tube 1, the DC voltage Ea must be kept constant at all times.

Means for Solving the Problems In a fluorescent display tube in which a cathode filament, a grid electrode, and an anode electrode are arranged facing each other in sequence, an anode is provided in which a grid electrode, a cathode filament, and an anode electrode are connected in series, with resistances at both ends being approximately the same. The common electrodes are arranged in parallel, and a voltage is applied across the cathode filament, the grid electrode, and the anode common electrode.

A grid electrode having substantially the same resistance at both ends and a common anode electrode in which a cathode filament and an anode electrode are connected are arranged in parallel, and a voltage is applied to both ends of the cathode filament, the grid electrode, and the common anode electrode. By applying the voltage, the voltage level difference between one cathode filament, the grid electrode, and each anode electrode becomes the same, and the electrons guided from the cathode filament to the anode electrode by the grid electrode are uniform.

Embodiment A first embodiment of the present invention will be described with reference to FIGS. 1 to 3. Note that the same parts as in the conventional example described above will be given the same names and symbols, and the explanation will be omitted. First, in the matrix fluorescent display tube 6 of this embodiment, the cathode filament 7
The resistances at both ends of the grid electrode 8 and the anode common electrode 9 are formed to have substantially the same value. As illustrated in FIG. 2, the grid electrode 8 of this matrix fluorescent display tube 6 is
is formed on the insulating substrate 10 by thin film printing and is parallel to the cathode filament 7.

Further, on the insulating substrate II disposed below the insulating substrate IO, an anode electrode 13 having a fluorescent material 12 provided at the end thereof is provided in succession in the longitudinal direction of the cathode filament 7, etc. The anode electrodes 13 are each connected to the anode common electrode 9 formed parallel to the cathode filament 7 and the like via an IC (not shown). That is, in the fluorescent display tube 6 of this embodiment, an IC is provided between the anode common electrode 9 and the anode electrode 13 in order to individually light up each dot made of the fluorescent material 12.

For example, the resistance at both ends of the cathode filament 7 is approximately 150Ω, and the resistivity of the grid electrode 8 is 4.5.
Assuming that the grid electrode 8 is made of an aluminum material with a diameter of Since the grid electrode 8 formed of such a thin film generates significant heat, the insulating substrate 10 is formed of a metal substrate or the like with good heat dissipation. There is.

In this matrix fluorescent display tube 6, as illustrated in FIG. 1, a DC voltage Ef is commonly applied to each electrode 7 to 9, and in addition, a DC voltage Ec and an anode A DC voltage Eb is applied to the common electrode 9.

In such a configuration, each electrode 7 is connected in two series.
Since the resistances at both ends of these electric terminals 4f27 to 9 are approximately the same value, the voltage applied to the voltages 27 to 9 is as shown in FIG.
The voltage level difference (slope) becomes the same. Therefore, the electrons induced from the cathode filament 7 by the grid electrode 8 are uniform in the longitudinal direction of the cathode filament 7, and the fluorescence efficiency of each anode electrode 13 driven by the IC is
2 will emit light with uniform brightness.

Next, a second embodiment of the present invention will be described based on FIG. 4. In this matrix fluorescent display tube 14, the grid electrode 15 is formed from the same wire as the cathode filament 7. The other structure is the same as that of the double matrix fluorescent display tube 6.

In such a configuration, this matrix fluorescent display tube 1
4 functions similarly to the matrix fluorescent display tube 6 described above.

In addition, in this matrix fluorescent display tube 14, since the grid electrode 15 and the cathode filament 7 are formed from the same wire, the electrodes 7 and 15 having the same resistance at both ends can be easily obtained, and the production of the matrix fluorescent display tube 14 is easy. Good properties.

Effects of the Invention As described above, the present invention arranges in parallel a grid electrode having substantially the same resistance at both ends, a common anode electrode in which a cathode filament and an anode electrode are connected, and connecting these cathode filaments and the grid electrode. By applying a voltage to both ends of the cathode filament, the grid electrode, and each anode electrode, the voltage level difference between the cathode filament, the grid electrode, and each anode electrode becomes the same, and the electrons guided from the cathode filament to the anode electrode by the grid electrode are uniform. Therefore, it is possible to obtain a 7-trix fluorescent display tube with uniform luminance and no unevenness.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of the electrical configuration of the first embodiment of the present invention,
2 is a perspective view, FIG. 3 is an explanatory diagram of the level difference between the voltages at both ends, FIG. 4 is a perspective view of the second embodiment, and FIG. 5 is a longitudinal side view of the conventional example. 6.14... Matrix fluorescent display tube, 7... Cathode filament, 8, 15... Grid electrode, 9...
- Anode common electrode, 13... Anode electrode, Ef. Ec...voltage

Claims (1)

[Claims] In a fluorescent display tube in which a cathode filament, a grid electrode, and an anode electrode are arranged facing each other in sequence, a grid electrode having substantially the same resistance at both ends and a common anode electrode in which a cathode filament and an anode electrode are arranged in parallel are arranged in parallel. A matrix fluorescent display tube characterized in that a voltage is applied across the cathode filament, the grid electrode, and the anode common electrode.