JPS63313456A - Fluorescent character display tube - Google Patents

Abstract

PURPOSE:To prevent generation of uneven luminance without any deformation of a grid by forming the material of the grid with an alloy whose principal components are iron and nickel. CONSTITUTION:The grid 3 of a fluorescent character display tube is in a rectangular shape 30mm and 80mm long in its width and length, and has 0.05mm thickness with fixing tabs 21 formed in 0.5mm height. The material used in this grid 3 is a Fe-Ni alloy consisting of nickel by 36(wt.)% and iron by the rest (wt.) %. In some other example, the tabs for fixing the grid are not employed but external leads 31 extended continuously from the grid 3 are employed and arranged in their forms at a form arranging part 32 so that a gap can be reserved between an anode and the grid 3. Hereat, external leads 31 are extended outward by penetrating a cover glass 5. The material used in this grid 3 is also a Fe-Ni alloy consisting of nickel by 36(wt.)% and iron by the rest (wt.)%. Thereby, even though the size of the grid is enlarged, almost no deformation can be observed during operation, resulting in absolutely no existence of a fault like uneven luminance, in comparison with a fluorescent character display tube with its gride made of 426 alloy.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a fluorescent display tube, and more particularly to a grid.

[Conventional technology]

A conventional fluorescent display tube generally has a structure shown in FIG. 4, for example. In the same figure, a glass substrate IK, display segment 2 as an anode (forming a desired pattern with a conductor,
A phosphor is deposited on it to form a grid 3.
The structure is such that a cover glass 5 is placed over the glass substrate 1 and welded with a solder glass 6 so as to house necessary parts such as the filament 4 and the like, and the inside is evacuated. Hi\
The grid 3 is usually made of 426 alloy (42% Ni, 5% Cr) whose expansion coefficient matches well with that of the glass substrate 1.

(remaining Fe) is used. This grid 3 is provided with a fixing tab 201, and this fixing tab 21 is filled with silver)
The glass substrate IK is fixed with a crystallized glass film, and is connected to one end of a pre-provided Ag wiring 8 (wired under the insulating layer 9). electrically connected. In addition, in order to obtain a certain gap between the grid 3 and the anode, the fixing tab 21 is attached to the bent portion 2 as shown in FIG.
2, it has been formatted in advance.

[Problem that the invention seeks to solve]

In recent years, the uses of fluorescent display tubes have expanded, and the display patterns have expanded from the traditional numbers to include a wide variety of symbols and designs.Inevitably, products with larger display patterns have been developed. When it comes to large varieties,
The area of the grid is also large, which has led to the following problems. That is, as explained in FIG. 4, electrons emitted from the filament 4 pass through the grid 3 and collide with the phosphor of the display segment 2, causing the phosphor to emit light, but some electrons are captured by the grid 3. (The kinetic energy when captured is converted into thermal energy), causing the temperature of the grid 3 to rise.

Due to this temperature increase, the thermally expanded grid 3 becomes a curved grid 3', as shown in FIG. There is a problem that unevenness occurs in the light emission state. In particular, as the area of the grid 3 increases, the curvature also increases, and this problem has become so large that it cannot be ignored.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and to provide a fluorescent display tube in which the grid is not deformed and therefore the light emission state is not uneven.

[Means for solving problems]

The present invention provides a fluorescent display tube in which an anode having a phosphor coated on an insulating substrate, a filament that generates electrons, and a grid that controls the electrons are housed in a vacuum container. The material is made of an alloy whose main components are iron and nickel.

〔Example〕

Next, the present invention will be explained in detail with reference to the drawings.

FIG. 1 is a perspective view showing a fluorescent display tube according to an embodiment of the present invention. In the figure, the grid 3 of the fluorescent display tube of this embodiment is a rectangular one with a height of 30 mm and a length of 80 mm, a thickness of α05 m, and a shaped height of the fixing tab 21 of 0.5 square. did. The material of this grid 3 is nickel (Ni) 36
(wt)%, the balance was iron (Fe). FIG. 2 is a perspective view showing a fluorescent display tube according to another embodiment of the present invention. In the same figure, this embodiment does not use a grid fixing tab, but has an external lead 31 that is continuously drawn out from the grid 3, and is shaped in a shaping section 32 to connect the anode and the grid 3. I'm taking a gap. The main feature here is that the external leads 31 penetrate the cover glass 5 and are drawn out to the outside. The material of the grid 3 in this example is also Ni36(Wt)%, Fe
A Fe--Ni alloy consisting of the remainder was used.

The Fe-Ni alloy used in the fluorescent display tube of the above example is:
In the relationship between the Fe-Ni component ratio and the thermal expansion coefficient, N
The lowest value is when i is 36(wt)%, and Ni is 36(wt)%.
Whether it increases or decreases by %, the coefficient of thermal expansion increases. As shown in Figure 3, this thermal expansion characteristic line is 10
There is almost no expansion up to around 0°C, and when the temperature exceeds 100°C, it rapidly expands and becomes cold.

The conventionally used 426 alloy does not exhibit these properties.

In this example, these characteristics were applied to the grid of a fluorescent display tube. That is, in FIG. 3, the material 42 suddenly begins to expand when the temperature exceeds 100'C, and is near the temperature at which it is fixed to the envelope 41 (usually this temperature is several 100'C). (For convenience, this point is indicated as 500.) Since the elongation rate is y equal to the elongation rate of the envelope,
The grid is fixed and does not deform even after cooling to room temperature. Incidentally, when the material 43 shown in Fig. 3 is used for the grid, the elongation rate of the material 43 is small at the fixation temperature of 500, so after cooling to room temperature, deformation corresponding to the expansion difference with the envelope 41 occurs. appears on the grid.

Furthermore, the temperature of the grid that rises during operation of 1 fluorescent display tube is 1
Since the temperature is about 00℃, the limit when using material 42 in Figure 3 is
In this temperature range, deformation of the grid hardly appears, and therefore, a fluorescent display tube is obtained that is free from the risk of uneven brightness during operation. Here, Ni is 36 (wt
)% is most preferable, and Ni is 33 (wt)%.
% to 39 (Wt)%. The reason for this restriction is that outside this range, the coefficient of thermal expansion becomes too high and the aforementioned effects cannot be expected.

〔Effect of the invention〕

As explained above, the present invention has the advantage that although the grid has become larger in size, there is almost no deformation during operation, compared to the conventional 42
Compared to fluorescent display tubes that use alloy 6 for the grid, this has the effect of completely eliminating defects in brightness unevenness.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing a fluorescent display tube according to an embodiment of the present invention;
Fig. 2 is a perspective view showing a fluorescent display tube according to another embodiment of the present invention, Fig. 3 is a characteristic diagram showing the expansion characteristics of the main materials of the fluorescent display tube shown in Fig. 1, and Fig. 4 is a conventional fluorescent display of the company. a perspective view showing a tube;
5 is a perspective view showing the grid portion of FIG. 4, and FIG. 6 is a sectional view showing a deformed state of the grid shown in FIG. 1...Glass substrate, 2...Display segment, 3...
・Grid, 4... Filament, 5... Cover glass, 6... Solder glass, 7... Ag-containing comb crystallized glass 8... Ag wiring, 9... Insulating layer, 10...
...Power supply lead, 21...Fixing tab, 22...Bending part, 31...External lead, 32...Orthopedic part, 41
...Envelope glass, 42...Fe-Ni alloy, 43
...Other materials, 500...Fixing temperature. Agent Patent Attorney Nai Rin Onsei 1 Koutei 2 Diagram

Claims (2)

[Claims] (1) In a fluorescent display tube comprising an anode with a phosphor coated on an insulating substrate, a filament that generates electrons, and a grid that controls the electrons, housed in a vacuum container,
A fluorescent display tube characterized in that the material of the grid is made of an alloy containing iron-nickel as a main component. (2) A fluorescent display according to claim (1), characterized in that the nickel component in the iron-etching material that is the material of the grid is from 33 (wt)% to 39 (wt)%. tube.