JPH023251B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for fixing an electrode for a fluorescent display tube having a plurality of control electrodes within an envelope.

A fluorescent display tube obtains a fluorescent display by accelerating and controlling electrons emitted from a heated filament-shaped cathode using a control electrode and selectively causing them to strike an anode having a phosphor layer coated on its upper surface. Since it is a self-luminous display device that can emit light of any color and provide a bright and easy-to-see display, it has come to be widely used as a variety of display devices from automobiles to computer terminals.

The general structure of this fluorescent display tube is shown in FIG.

In FIG. 1, reference numeral 1 denotes a substrate made of an insulating material. On this substrate 1, a wiring conductor 2, an insulating layer 3 having a through hole 3a formed at a predetermined position, and a predetermined wiring through the through hole 3a. Anode conductors 4 electrically connected to conductor 2 are sequentially stacked.

In addition, in a fluorescent display tube of the type in which light emission is observed from the substrate 1 side recently developed by the present applicants, the substrate 1 is formed of a translucent material such as glass or ground glass; Further, an opening matching the shape of the anode is formed in the insulating layer 3,
Here, a translucent anode conductor made of a transparent conductive film or a mesh-like thin metal wire connected to a predetermined wiring conductor 2 is arranged.

Then, a phosphor layer 5 is deposited on the anode conductor 4 to form an anode portion 6, and the anode portions 6 are arranged, for example, in a Japanese character shape as shown in the figure to constitute a single digit pattern display portion.

Furthermore, a control electrode 7 is provided above the anode section 6 for each digit, and a filament-shaped cathode 8 is stretched over the control electrode 7. Also,
A holding frame of the control electrode 7, a part of which becomes the external terminal 9, is passed through the holding frame of the control electrode 7 in an airtight manner, and a container part 10 is sealed around the substrate 1. Evacuate the inside of the enclosure to a high vacuum state,
This is a fluorescent display tube.

Then, the light emission of the phosphor layer 5 obtained by selectively causing the electrons emitted from the cathode 8 to impinge on the anode section 6 is observed from the container section 10 or the substrate 1 side.

In addition to the above-mentioned features, this fluorescent display tube operates at a relatively low voltage and can be directly driven by LSI etc., and can display not only numerical displays using the date-shaped pattern shown in the figure, but also graphic displays using dot patterns and various other types. It has the excellent feature of being able to form arbitrary patterns such as symbols and patterns.

Taking advantage of this latter feature, display patterns have recently become more diverse. For example, as a pattern for time display, elongated anode parts corresponding to the hands of a clock are arranged radially, and electrons are selectively applied to these anode parts. Display tubes that display the time in an analog manner and display tubes that display different types of display patterns in a composite manner within a single display tube have come into practical use.

In this case, as the display pattern becomes finer and the number of anodes increases, a dynamic drive system or a duplex drive system is adopted to reduce the number of external terminals. That is, a plurality of anode sections are divided into groups (in the case of a duplex system, divided into two), and corresponding anodes of each group are commonly connected on the substrate and led out to the outside. The selection of each group is performed by control electrodes that are electrically independently connected to external terminals.

For example, this dynamic drive method is often used when displaying a multi-digit number or character pattern arranged in a row. It is possible to hold and fix the control electrode electrically separated by the attachment part. However, if there are multiple rows of pattern display parts with multiple digits in one display tube, or if different types of display patterns are to be displayed in a complex manner, only the sealed part of the envelope can be used. Therefore, it becomes difficult to hold and fix the control electrode.

Examples of the arrangement structure of the control electrode 7 with respect to the substrate 1 in such a case are shown in FIGS. 2a to 2c.

In these examples, since a part of the edge of the control electrode 7 is located inside the envelope, the peripheral part of the substrate 1 is
Even if the holding portion of the control electrode 7 is clamped and fixed between the substrate 1 and the container portion, the holding and fixing of the control electrode 7 will be insufficient.

Therefore, in a fluorescent display tube having a control electrode arrangement structure as shown in FIG. proposed a fluorescent display tube having a structure in which an extended-shaped insulator 7a is disposed and opposing edges of adjacent control electrodes are connected and held via the insulator 7a. No. 20932).

This structure has the advantage that the control electrode is prevented from floating within the display tube, and the control electrode is securely fixed.

However, in this structure in which the opposing edges of the control electrode are connected and held using the elongated insulator, it is necessary to fix the insulator after positioning the control electrode at a predetermined position on the substrate. The disadvantage is that the work process becomes complicated.

Furthermore, the edge of the control electrode located inside the tube is
It doesn't necessarily have to be a straight line. For example, in display tubes that display analog time, the edges of the control electrodes are often arcuate, and in such cases it is difficult to adopt the structure of the aforementioned Japanese Utility Model Publication No. 56-20932.

Particularly in recent years, the trend toward larger panels in the fluorescent display field
As display patterns become more complex, there has been a need for an effective method for holding and fixing control electrodes within display tubes.

The present invention has been made in view of the above-mentioned circumstances, and by using a control electrode portion having an insulating support of a predetermined thickness fixed to the edge portion in advance,
An object of the present invention is to provide a method for fixing an electrode for a fluorescent display tube, which simplifies the manufacturing method and also allows a control electrode section to be securely fixed within a display tube regardless of the shape of the edge of the control electrode section. That is.

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides an electrode fixing method for a fluorescent display tube having a plurality of control electrode parts, at least some of which are supported on a substrate within an envelope. a step of fixing in advance an insulating support of a predetermined thickness with crystallized glass to the bottom surface of the end edge of the plurality of control electrode parts to be supported within the envelope to integrate the control electrode parts;
A step of fixing and integrating the insulating support on the substrate on which the anode part is formed, aligning and placing the control electrode part, and clamping and fixing the holding part of the control electrode part by the sealing part of the envelope. This includes the process of

Hereinafter, an embodiment of the method for fixing an electrode for a fluorescent display tube according to the present invention will be described with reference to the drawings.Here, the present invention will be explained using a fluorescent display tube that displays analog time as an example.

In order to explain the schematic structure of a fluorescent display tube obtained by the manufacturing method of the present invention, FIG. It shows the process of aligning and mounting the electrode part, and shows a part of the control electrode part cut away to clarify the state of formation of the anode part.

However, in FIG. 3, numeral 11 is a substrate made of an insulating material, and is made of an insulating material such as glass or ceramics.

Then, an anode section for analog time display is formed on this substrate 11. The method of forming this anode section is slightly different between display tubes of the type where the display is viewed from the substrate side and types of display tubes where the display is viewed from the container side.
Here, we will discuss the case where the display is viewed from the container side.

First, a wiring conductor is formed on the substrate 11 using, for example, a conductive paste, and an insulating layer 1 is formed on the wiring conductor.
2 is loaded. This insulating layer 12 has through holes communicating with wiring conductors and openings for connection with external terminals formed at predetermined positions.

Then, an anode conductor electrically connected to a predetermined wiring conductor via a through hole is formed on the insulating layer 12 by, for example, a screen printing method,
A phosphor layer is deposited on the upper surface to form the anode section 13. In this embodiment, since the pattern is for analog time display, the anode section 13 has a shape in which a plurality of elongated rectangular bodies are arranged radially. are concentrically divided into two parts.

Thus, the control electrode section 14 is positioned and placed on the substrate 11 on which the anode section 13 is formed as described above. Here, the control electrode section 14
are mesh-shaped control electrode bodies 15, 15 ₁ to 15 _o that are electrically separated and individually driven to accelerate and control electrons, and this control electrode body 1
5, and a holding part 16, a part of which also serves as an external terminal. And the holding part 16
are connected by a connecting member 16a which is cut and removed together with the unnecessary holding part 14 in the final process in order to facilitate handling during the display tube assembly process.

Further, an insulating support 17, which is a main part of the present invention, is fixed to the control electrode section 14 in advance.

That is, as shown in FIG. 4, an insulating support made of, for example, ceramics or glass and processed to a predetermined thickness is attached to the inner end edge of the control electrode section 14 to be supported within the display tube envelope. 17 is fixed in advance with an adhesive 18. This insulating support 17 can have any shape as long as it does not inhibit the action of the control electrode body 15, but in this embodiment it is a flat cylindrical body. The adhesive 18 is made of a material that does not dissolve in the subsequent sealing process, for example, a paste of crystallized glass powder whose softening temperature increases once it is melted and solidified, and is used at the end of the control electrode body 15. The edge portion and the insulating support 17 are coated and fired to fix them together.

The control electrode section 14 thus obtained is positioned and mounted on the substrate 11 as shown in FIG. Thereafter, a filament-shaped cathode is stretched between cathode supports (not shown).

Next, as shown in the sectional view of FIG. 5, the container part 19 is sealed around the periphery of the substrate 11, and the holding part 16 of the control electrode part 14 is also fixed. That is, the holding section 16 is held between the substrate 11 and the container section 19, and the sealing material 20 filled between the substrate 11 and the container section 19 is fired and solidified to seal them together. , fixes the holding part 16. In addition, in FIG. 5, 21 indicates a wiring conductor, and 22 indicates a cathode.

Furthermore, after that, the inside of the envelope formed by the substrate 11 and the container part 19 is evacuated to a high vacuum state, and at the end of this evacuation process, the cathode 22 is activated as shown in FIG. After completing the manufacturing process, the fluorescent display tube is completed.

As is clear from FIG. 5, the edge of the control electrode section 14 inside the envelope is supported by the insulating support 17 to define its height, and the holding section 16 is Since the control electrode part 14 is clamped and fixed by the sealing part, the control electrode part 14 can be held and fixed securely and firmly. In particular, in a fluorescent display tube, the distance between the cathode 22 and the control electrode section 14 greatly influences the luminance of the anode section 13. Therefore, the installation height from the surface of the substrate 11 to the control electrode body 15 is extremely important in achieving uniform brightness in each anode section 13. In the structure shown in FIG. supports the edge of the control electrode section 14 as a height regulating member, and also supports the holding section 1
6 supports the other end of the control electrode section 14, so the control electrode main body 15 itself is supported at a predetermined installation height with respect to the surface of the substrate 11, and the distance between the cathode and the control electrode is constant. This makes it possible to equalize the brightness.

Moreover, since the insulating support 17 is fixed in advance to the edge of the control electrode section 14, no special work is required for supporting and fixing the control electrode section 14 in the display tube assembly process. First, it can be easily manufactured by the same process as the conventional display tube having the general structure shown in FIG.

Further, since the insulating support 17 is fixed to the edge of the control electrode section 14 in advance, the substrate 11
When the container part 19 and the container part 19 are sealed together, there is no fear that impurities such as harmful gases that cause phosphor contamination will be released from the fixed part of the insulating support 17.

Furthermore, if necessary, an adhesive is interposed between the insulating layer 12 and the insulating support 17, so that the control electrode portion 1
It is also possible to make the fixation of the edge portion of 4 more solid.

In addition, in the present invention, the light emission from the anode portion 13 is transferred to the substrate 1.
Of course, it can be applied to a type of fluorescent display tube that is observed from the 1 side.
The present invention can be applied even when the edge portion is linear or zigzag, and is not limited to the embodiments described above and shown in the drawings, and can be implemented in various ways without changing the gist. be.

As described above, according to the method for fixing electrodes for a fluorescent display tube according to the present invention, at the edge portions of the plurality of control electrode parts to be fixed in the display tube envelope,
A plurality of control electrode parts are integrated by fixing an insulating support of a predetermined thickness with crystallized glass in advance, and the integrated control electrode part is aligned and placed on a substrate on which an anode part is formed, and then a filament is attached. After arranging the cathode in a stretched manner, the container part constituting the display tube envelope together with the board is sealed to the peripheral part of the board, and at the same time, the holding part of the control electrode part is fixed by this sealing. This allows the control electrode section to be fixed in place.

Therefore, when assembling the display tube, there is no need to align multiple control electrodes individually and then fix them with insulators at a certain height from the substrate in order to fix the control electrodes inside the envelope. Therefore, the manufacturing process is greatly simplified, and the effects obtained in terms of manufacturing are extremely large.

In addition, since the insulating support is processed in advance, its thickness can be precisely regulated, and the installation height of the control electrode within the envelope can be precisely regulated to achieve the desired luminance. This has the advantage that uniform light emission can be obtained for each anode portion. Furthermore, since there is no risk of harmful substances that would inhibit the luminescence of the phosphor being released from the fixed part of the insulating support, the luminance can be expected to be improved. Manufactures large fluorescent display tubes that are driven by the dynamic method or duplex method and have multiple control electrode sections separated into two, as well as composite fluorescent display tubes that display various patterns with different display formats on the same display tube. It is highly effective in doing so.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway plan view showing the general structure of a conventional fluorescent display tube, FIGS.
3 to 5 are diagrams for explaining an embodiment of the method for fixing an electrode for a fluorescent display tube according to the present invention, and FIGS. It is a figure for explaining an example. DESCRIPTION OF SYMBOLS 11... Substrate, 13... Anode part, 14... Control electrode part, 15... Control electrode main body, 16... Holding part, 17... Insulating support body, 19... Container part, 20
... Sealing material, 22 ... Cathode.

Claims (1)

[Claims] 1 At least a part of the edge part has a plurality of control electrode parts supported on the substrate within the envelope, and electrons emitted from the cathode are accelerated and controlled by the control electrode part, and the phosphor layer is In the method for fixing the control electrode part of a fluorescent display tube that performs a light emitting display by colliding with a coated anode part, the control electrode part is attached to the bottom surface of the edge part of the plurality of control electrode parts to be supported within the envelope. A step of fixing an insulating support of a predetermined thickness with crystallized glass in advance to integrate the individual control electrode parts, and positioning the integrated control electrode part on the substrate on which the anode part is formed. At the same time, a container part that constitutes an envelope together with the substrate is sealed to the peripheral part of the substrate, and at the same time, the individual control electrode parts are held by the sealing part between the substrate and the container part. A method for fixing an electrode for a fluorescent display tube, comprising the step of clamping and fixing the electrode by only the sealing part on one side of the envelope.