JPS6224530A - Manufacture of fluorescent character display tube - Google Patents

Abstract

PURPOSE:To simplify the manufacturing process by separating the process for forming a control electrode on a control electrode substrate while adhering the substrate formed with control electrode to an anode plate substrate prior to formation of anode pattern. CONSTITUTION:Anode pattern electrode forming process for arranging at least one row of anode pattern electrodes 2 composed of conductive material onto an anode plate substrate 1 and process for forming control electrodes 5 onto a control electrode plate 4 are executed independently. An adhesive layer 3 is formed onto the anode plate substrate 1 then both substrates are jointed and adhered through adhesion layer burning process to form an anode pattern 6 through anode pattern forming process thereafter finally assembled.

Description

[Detailed description of the invention] (Technical field) The present invention relates to a method for manufacturing a fluorescent display tube.

(Prior Art) In a fluorescent display tube, a fluorescent screen is formed on a large number of anode pattern electrodes arranged in one or more rows in one direction, and this is sealed in a vacuum container together with a hot cathode. While generating thermoelectrons, a positive voltage is selectively applied to the anode pattern electrodes according to the information to be displayed, attracting the thermionic electrons to the selected anode pattern electrode, and the thermoelectrons collide with the phosphor screen. Information is displayed by the fluorescence emitted during the display, and they are already well known as barcode display tubes and phosphor dot array tubes.

First, referring to FIG. 4, an outline of a fluorescent display tube will be explained using a fluorescent dot array tube as an example.

In FIG. 4, reference numeral 20 indicates an anode plate substrate made of glass, ceramic, resin, or the like. The anode plate substrate 20 includes a series of anode pattern electrodes 21.
are arranged in a row in the longitudinal direction of the substrate, and each of the anode pattern electrodes 21 is formed with an anode pattern 22 made of a fluorescent screen.

The size of each phosphor screen is 40 x 40 μm2.
Although the size of the phosphor screen is extremely small, such as 50 x 50 μM, the size of the phosphor screen is shown larger than the other members in the figure.

On both sides of the anode pattern arrangement of the anode plate substrate 20, thick film insulating layers 23, 23 are formed along the longitudinal direction of the substrate, and control electrodes 24, 24 are formed on these, respectively. In FIG. 4, reference numeral 25 indicates a tungsten wire as a hot cathode stretched in the longitudinal direction of the substrate, the surface of which is coated with an electron emissive material such as BaSr. Further, reference numeral 26 denotes a face member formed of a transparent material such as glass, and as shown in FIG. 5, it is integrated with the anode plate substrate side. Thus, the anode plate substrate 20, the thick film insulating layers 23, 2
3. The control electrodes 24, 24, and the face member 26 form a closed space, and within this space, the anode pattern electrode 21
, anode pattern 22, and hot cathode 25.25 are confined.

The closed space is highly evacuated.

Appropriate voltages are applied to the control electrodes 24, 24,
When an alternating current of several tens of milliamps is passed through the hot cathode 25.25, the hot cathode 25.25 is heated by Joule heat and emits thermoelectrons. In this state, when a positive voltage is applied to one of the anode pattern electrodes 21 to make it a positive potential, the thermoelectrons are transferred to the anode pattern electrode 2 at the positive potential.
When the anode pattern 22 is attracted to the electrode part 1 and sucked into the electrode part, the energy state of the fluorescent material of the anode pattern 22 is excited. The excited fluorescent substance emits fluorescence when returning to the ground state. This fluorescence is observed through the face member 26.

Such a phosphor dot array tube is used as a part of the optical system of an optical printer or as a bar code display tube.

Conventionally, in such a fluorescent display tube, an anode pattern electrode 21 consisting of a strip-shaped electrode is formed on an anode plate substrate 20 by photoetching, and a part of the electrode 21 is exposed by screen printing. A thick film insulating layer 23 made of thick film insulating glass is formed on the surface of the substrate including the electrodes, and then fired.

Next, only a portion of the exposed electrode is exposed, and the surface of the substrate including the electrode is covered with a photoresist layer. Then, in the phosphor screen forming step, the substrate is immersed in a dispersion liquid in which phosphor particles are dispersed, facing the counter electrode at a predetermined distance, and a voltage is applied between the anode pattern electrode and the counter electrode. do. The phosphor particles in the dispersion liquid move toward the anode pattern electrode due to the electric field formed between the two electrodes, and adhere to the exposed electrode portions to form the anode pattern. The control electrode 24 is formed by an appropriate method such as photoetching after the phosphor screen is formed. Then, the anode pattern substrate 20 on which each electrode and anode pattern are formed is integrated with the face member 26.

By the way, in the manufacturing method described above, the anode plate substrate 20 has an anode pattern electrode 21 . Thick film insulation layer 2
3. All of the steps for forming the control electrode 24 must be performed. In other words, there is a problem that the manufacturing process of the fluorescent display tube becomes long.

(Objective) An object of the present invention is to provide a method for manufacturing a fluorescent display tube that simplifies the manufacturing process.

(Structure) The present invention separates the control electrode forming step of forming a control electrode on a control electrode substrate, and allows the substrate on which the control electrode is formed to be
The feature is that it is bonded to the anode plate substrate before the anode pattern is formed.

The present invention will be explained in detail below.

FIG. 1 shows the steps of the present invention, including an anode pattern electrode forming step in which at least one row of anode pattern electrodes made of a conductive material is provided on an anode plate substrate, and a control electrode formed on the control electrode substrate. The control electrode forming process is carried out independently, and after forming an adhesive layer on the anode plate substrate, the peripheral substrate is bonded and the side substrate is bonded in the adhesive layer baking process, and the anode pattern forming process is performed. After forming the anode pattern (phosphor screen), the final assembly process begins.

Each step will be explained in detail below.

Step 2 of Forming Electrodes for Anode Patterns Anode pattern electrodes made of aluminum are formed on one surface of the anode plate substrate 1 made of, for example, a glass plate shown in FIG. is formed by a photoetching method.

The anode pattern electrodes 2 are strip-shaped with a width of about 50 μm, and are formed in a row in the longitudinal direction of the substrate (perpendicular to the plane of the paper) with an interval of about 35 μm between adjacent electrodes. portions (not shown) are drawn out to the left and right side edges of the board every other time.

Adhesive Layer Forming Step As shown in FIG. 2(3), an adhesive layer 3 made of hot melting glass is formed on the anode plate substrate 1, including the anode pattern electrode 2. At this time, a part of the anode pattern electrode 2 is exposed as an exposed portion 2a.

Control electrode forming process The insulating control electrode substrate 4 made of lead glass, for example, shown in FIG.
As shown in a), a mesh-like control electrode 5 is formed.

Adhesive Layer Firing Step This step is a step of bonding the substrate 1 on which the adhesive layer is formed and the control electrode substrate 4.

As shown in FIG. 2 (4), the control electrode substrates 4, 4 are placed on the adhesive M3, 3 of the anode plate substrate 1, respectively, and are fired in a firing furnace to melt the adhesive layer. The front side substrates 1 and 4 are bonded together.

Phosphor screen formation step In this step, as shown in FIG. 2 (4), phosphor particles are deposited on the exposed portion 2b of the configured substrate assembly 7 by electrodeposition, and as shown in FIG. 2 (5). This is a step of forming an anode pattern 6 as shown.

The substrate assembly 7 shown in FIG. 2(4) is attached to the phosphor screen forming apparatus 8 shown in FIG. 3.

The phosphor screen forming device 8 uses isopropyl alcohol ((CH
3) Zinc oxide phosphor (Z
A tank 10 stores a phosphor particle dispersion liquid 9 in which aluminum nitrate (Al(NO3)3.9H20) as a control agent is dissolved and a dispersion of aluminum nitrate (Al(NO3)3.9H20) as a control agent is stored. It consists of a counter electrode 11 and a power source 12 that supplies DC voltage to this electrode. The substrate assembly 7 is supported by a support means (not shown) and immersed in the dispersion liquid 9. At this time, the substrate assembly 7 is placed with its exposed portion 2a facing the counter electrode 11 with a predetermined distance therebetween. The anode pattern electrode 2 is connected to the negative electrode of the power source 12, and the two control electrodes 5, 5, like the counter electrode 11, are connected to the positive electrode. It may also be possible to adjust the voltage value applied to the control electrodes 5, 5. Further, the phosphor particle dispersion liquid 9 is stirred by a stirring means (not shown).

Then, when the power switch 13 is closed and a voltage is applied between the anode pattern electrode 2 and the counter electrode 11,
An electric field is formed between the two, and the phosphor particles in the dispersion liquid 9 undergo electrophoresis and move toward the anode pattern electrode 2 side. The moved phosphor particles adhere to the exposed portion 2a of the anode pattern electrode in a layered manner to form an anode pattern 6 consisting of a phosphor screen.The anode pattern 6 formed on the exposed portion 2a of the anode pattern electrode is , the shape and size may be regulated by a mask (not shown). After a preset time has elapsed for the anode pattern 6 to reach the desired thickness, the substrate assembly 7 is lifted from the dispersion 9. Thereafter, when the adhered dispersion is dried and the liquid component is blown off, the remaining phosphor particles form an anode pattern 6 as shown in FIG. 2 (5).

When the control electrode 5 is connected to the same polarity as the counter electrode 11 when forming the anode pattern, the shape and size of the phosphor screen can be controlled, and it is possible to prevent phosphor particles from adhering to areas other than desired positions, that is, so-called extrusion.

Assembly process The substrate assembly 7 on which the anode pattern 6 shown in FIG.
After being stretched, it is assembled integrally with a face member 15 made of a transparent material. With the above steps, the fluorescent display tube 16 has been manufactured. At this time, the closed space 17 is highly evacuated. Note that in the fluorescent display tube 16 shown in FIG. 2(6), the lead wire portion of each electrode is omitted.

(Effects) As described above, according to the present invention, in which the step of forming the control electrode is performed independently from a series of steps, and the control type military substrate is bonded to the anode plate substrate, the fluorescent display tube The manufacturing process can be simplified.

Furthermore, when forming the anode pattern, the shape of the phosphor screen can be controlled by making the control electrode the same polarity as the counter electrode.

[Brief explanation of drawings]

FIG. 1 is a process diagram showing the steps of the method for manufacturing a fluorescent display tube according to the present invention, FIG. 2 is a process diagram showing a specific example of the same in cross section, and FIG. 3 is a schematic diagram showing an example of a phosphor screen forming apparatus. cross section,
FIG. 4 is an exploded perspective view showing a phosphor dot array tube as an example of a fluorescent display tube, and FIG. 5 is a sectional view of the same. DESCRIPTION OF SYMBOLS 1... Substrate for anode plate, 2... Electrode for anode pattern, 3... Adhesive layer, 4... Substrate for control electrode, 5...
... Control electrode, 6. Anode pattern, 9. Fluorescent particle dispersion, 11. Counter electrode. Figure 2

Claims (1)

[Claims] In a fluorescent display tube having an anode pattern electrode provided on an anode plate substrate and a control electrode insulated from the anode pattern electrode, in the anode pattern electrode formation step, the anode pattern electrode is formed on the anode plate substrate. An anode pattern electrode made of a conductive material is provided, and in the adhesive layer forming step, a part of the anode pattern electrode is exposed along the electrode arrangement direction on the substrate surface including the anode pattern electrode, and an adhesive layer is formed. On the other hand, in the control electrode forming step, a control electrode made of a conductive material was provided on an insulating control electrode substrate, and the control electrode substrate was placed on the adhesive layer of the anode plate substrate. Afterwards, this is fired to bond both substrates together, and in an anode pattern forming step, phosphor particles are supplied to the anode plate substrate to which the control electrode substrate is bonded.
A method for manufacturing a fluorescent display tube, characterized in that an anode pattern is formed by attaching phosphor particles to the exposed electrode for the anode pattern.