JPS63221530A - Phosphor electrodepositing device - Google Patents

Abstract

PURPOSE:To improve the electrodeposition speed of a phosphor and form a high-quality fluorescent screen by immersing a panel stuck with e conductive layer and connecting a power supply between the conductive layer and an electrode bored with net-shaped through holes. CONSTITUTION:In a region A1, a conductive layer 8 electrodepositing a phosphor to a panel section 3 is arranged toward the outer periphery direction on the holder 25 of a holding means 23. In a region A2, the air blow processing is performed. In a region A3, a support shaft 24 is lowered, and the panel section 3 is immersed in a phosphor electrodepositing liquid in an electrodepositing liquid tank 21. This is lifted, then in a region A4 the support shaft 24 is lowered, and the panel section 3 is immersed in the electrodepositing liquid in the second electrodepositing liquid tank 22. At the same time, an electrode brush 27 is brought into contact with the projection 8a of the conductive layer 8 via a liaison arm 29 and a rotary arm 26. An electrode 36 bored with mesh-shaped through holes is used as a positive electrode, a current is fed between it and the electrode brush 27, and the phosphor is electrodeposited on the conductive layer 8 inside the panel 3. After the panel section 3 is lifted, it is immersed in a washing liquid in washing tanks 41-45 and washed.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a phosphor electrodeposition device which is commonly used and suitable for forming a fluorescent surface of a cathode ray tube, such as a portable small flat cathode ray tube. .

[Summary of the invention]

In the present invention, the counter electrode, which is immersed together with the panel portion of the cathode ray tube body in which the phosphor is to be electrodeposited, in an electrodeposition liquid bath for performing the phosphor electrodeposition is constituted by a net-like body having a large number of through-holes. This makes it possible to improve the phosphor electrodeposition speed and form a high-quality phosphor surface.

[Conventional technology]

A cathode ray tube, such as a small flat cathode ray tube, is a flat glass cathode ray tube, as shown in a perspective view in FIG. 10, a vertical sectional view in FIG. 11, and an exploded perspective view of the tube body in FIG. body (consisting of 11)

This tube [1] faces each other and has a flat space (
2), and one of these first and second panel parts (3) and (4), which are joined and sealed by fritting to form a It consists of a funnel part (5) which is also joined and sealed on the side by means of frits. This funnel part (5)
has a first and a second opening end (5a) on its large diameter side.
The panel parts (3) and (4) are joined and sealed, and the neck part (7) in which the electron gun (6) is housed is welded to the open end (5b) on the small diameter side.

As shown in an exploded perspective view in FIG. 12, the first and second panel parts (3) and (4) have main surfaces (3a) and (4a) facing each other, and a funnel part (5) thereof. The peripheral side surface extending from each of the other three side edges excluding the side edge joined with
3b) and (4b), and the mutually corresponding end surfaces of these peripheral surfaces (3b) and (4b) are fritted to form a flat space (2) between both panel parts (3) and (4). The panel parts (3) and (4) are arranged so that the flat space (2) communicates with the space in the funnel part (5) on the side where the peripheral surfaces (3b) and (4b) do not exist. The large-diameter opening end (5) of the funnel part (5)
a) is bonded and sealed by fritting.

A conductive layer (8) made of, for example, an aluminum vapor-deposited film is formed on a predetermined portion of the inner surface of the surface (3a) of the first panel part (3), and a fluorescent surface (9) is coated on this by electrodeposition. A deposit is formed. For example, a protective film (10) is placed on this fluorescent surface (9).
A transparent conductive layer (11) is deposited through the transparent conductive layer (11).

Also, on the inner surface of the funnel part (5), an internal conductor 11' made of, for example, a carbon coating film! (12) is deposited. Transparent conduction occurs through this conductive film (12) from an anode button (13) that is electrically connected to this internal conductive film (12) and provided on, for example, one side of the funnel portion (5).
(11), so that a required high anode voltage is applied to the fluorescent surface (9) and also to the high voltage electrode of the electron gun (6).

In such a configuration, the electron beam b generated from the electron gun (6) is made to impact the fluorescent surface (9), and the light emitted from this is observed from, for example, the surface (4a) side of the panel portion (4). being done. (14) shows a horizontal/vertical electromagnetic deflection device for the electron beam b.

In a cathode ray tube having such a configuration, the panel portion (3) is assembled prior to joining the first and second panel portions (3) and (4) described above, and the funnel portion (5).
) A phosphor electrodeposition is performed to form a phosphor surface (9) on a conductive layer (8) formed on a predetermined portion of the inner surface of the main surface (3a).

Phosphor electrodeposition for forming such a fluorescent surface (9) can be carried out by, for example, placing a panel part (3) on which a conductive layer (8) is formed on a predetermined part of its inner surface in a phosphor electrodeposition liquid bath. The conductive layer (8) in the panel part (3) is immersed in the electrodeposition liquid and an electric current is applied between the electrodes immersed in the electrodeposition liquid bath to form a phosphor on the conductive layer (8). A method of electrodeposition is used.

When using such a method, for example, the size of the fluorescent surface is 2
In case of inch type, the height of the counter electrode is 150mm,
A plate electrode made of a 50 mm titanium plate plated with platinum is used. On the other hand, the thickness of the phosphor film on the phosphor surface of the flat cathode ray tube described above is 3.5 mg±1.0 mg.
/crA, and the electrodeposition processing conditions for forming a 2-inch type fluorescent surface with a film thickness like Kono's are as follows: electrodeposition voltage 250
ν, interelectrode distance (distance between the conductive layer (8) on the inner surface of the panel part and the electrode immersed in the electrodeposition liquid) was 30 mm, and the electrodeposition time was 8.0 seconds. In contrast, the fluorescent surface area is 4
For a 4-inch type, which is twice the size, even if the electrodeposition voltage is increased by 20% to 300V and the distance between electrodes is reduced by 13% to 26mm, the electrodeposition time will be 21.0 seconds, which is about 2.6 times as long. Incidentally, FIG. 13 shows the results of measuring the relationship between the amount of phosphor deposited (i.e., the amount of electrodeposition) with respect to the electrodeposition voltage when the distance between the electrodes was fixed at 46 mm, and the volume curve (13
1), (+32).

(+33), (+34) and (135) are when the electrodeposition time was 1 second, 5 seconds, 10 seconds, 25 seconds and 50 seconds, respectively. In addition, Fig. 14 shows that the electrodeposition time is constant 1.
This shows the results of measuring the relationship between the distance between the electrodes and the amount of electrodeposition when the time is 0 seconds, and each curve (141),
(+42) and (+43) each have an electrodeposition voltage of 50
V, 100V and 250V. Furthermore, Fig. 15 shows the results of measuring the relationship between the electrodeposition time and the amount of electrodeposition when the distance between electrodes was selected as 46 mm, and in the figure, each curve (+51), (+52), (1
53) , (+54) and (155) are the electrodeposition voltages of 50V, 100V, 250V, 50
This is the case where the voltage is 0v and 700v.

In addition, each of the above-mentioned electrodepositions uses a phosphor (P45iY20
2S: Tb) is 19.78, In20i is 0.3
g, aluminum nitrate 20 mg, lanthanum nitrate 40
mg to 5ra1.mg of pure water. .

IPA (isopropyl alcohol) 200mI! Electrodeposition was performed using an electrodeposition solution prepared by mixing 1 ml of glycerin and dispersing the mixture with ultrasonic waves, while stirring the mixture with a magnetic stirrer.

[Problem that the invention seeks to solve]

The main problem to be solved by the present invention is to shorten the electrodeposition time, and in addition, to achieve stable electrodeposition and extend the life of the electrodeposition solution.

[Means for solving problems]

As shown in FIG. 1, the present invention includes an electrodeposition liquid tank (22) containing a fluorescent electrodeposition liquid, and an electrodeposition liquid immersed in the electrodeposition liquid (51) in this electrodeposition liquid tank (22). A panel part (3) is electrodeposited, which has an electrode (36) having a net shape or a large number of through holes, and an electrodeposited power supply S, and has a conductive N (8) deposited on a predetermined part of the inner surface. This conductive layer (8) and electrode (3) are immersed in a liquid (51).
6), an electrodeposition power source S is connected between the panel section (3) and the conductive layer (8) to perform electrodeposition of the phosphor.

The area of the electrode (36) is the same as that of the conductive layer (8) of the panel part (3).
The area can be selected to be equal to or larger than the area of .

Also, during the electrodeposition work, the electrodeposition liquid (5) in the electrodeposition liquid tank (22) is
1) is in a state of being stirred by a magnetic stirrer (61), which prevents precipitation of the phosphor in the electrodeposition liquid (51) and also prevents the phosphor from being deposited on the electrodeposited material, that is, the conductive layer (8).
subsidize the transition to

[Effect]

In the device of the present invention, since the electrode (36) is configured with a mesh or an electrode with a large number of through holes, the electrodeposition liquid (51) can pass through the electrode (36) during electrodeposition. This prevents the stirring and movement of the electrodeposition liquid (51) from being hindered. Therefore, the phosphor in the electrodeposition liquid (51) can be transferred favorably to the conductive layer (8) of the panel portion (3), resulting in efficient electrodeposition. In addition, by making the electrode (36) have a mesh-like or perforated structure through which the electrodeposition liquid can pass through, it is possible to make the electrode (36) large in area without interfering with the circulation of the electrodeposition liquid. The area of the electrode (36) is the electrodeposited surface of the phosphor, that is, the conductive layer (
8), and the conductivity N(8) can be made sufficiently larger than the area of
) can form a uniform electric field over the entire area,
By doing so, the fluorescent material can be electrodeposited uniformly and efficiently on each part.

〔Example〕

As shown in FIG. 2, a panel holding means (23) is provided which can rotate around a central axis 0.

As shown in FIGS. 1 and 3, this panel holding means (23) includes, for example, a vertically extending support shaft (24°) and a panel holding body on which the panel part (3) is placed or clamped below the support shaft (24 degrees). (25).A rotating arm (26) is provided at the lower end of the support shaft (24), and an electrode brush (27) is attached to the tip of the arm. A sleeve (28) is provided between the lower end of the sleeve and the pivot arm.
) provided at one end according to the vertical movement of the protrusion (29a)
However, for example, the guide groove (52) provided on the support shaft (24)
A connecting arm (29) is provided which engages and moves along the connecting arm (29) to rotate the pivoting arm (26) clockwise and counterclockwise.

As shown in FIG. 4, the electrode brushes (27) each have a plurality of thin metal wires (30) made of stainless steel SUS 304 with a diameter of 0.15 m and are supported at one end thereof. It is soldered to the piece (31) with solder (32).

Further, the rotating arm is elastically pushed downward by a spring (34) interposed between the sleeve (28) and the flange portion (33) integrally protruding from the support shaft (24). (26) is brought to a predetermined rotational position in the clockwise direction, and the thin wire (30) of the electrode brush (27) is inserted into a predetermined part of the conductive layer (8) of the panel part (3), specifically a protrusion described later. It is adapted to elastically abut against the portion (8a).

As shown in FIG. 5, a protrusion (8a) is provided on the conductive N (8) of the partial panel part (3), for example, on the side edge on the side where it joins with the funnel part (5), and the protrusion (8a) is provided here with an electrode. Brush (27
) contact is made.

The panel holding means (23) has a center axis 0 as shown in FIG.
Multiple areas on one circumference centered on .

In the figure, areas A1 to A12 are divided into 12 parts.
This is done so that the next movement can be carried out sequentially. In the illustrated example, a state in which one panel holding means (23) is provided is shown, but a plurality of panel holding means (23) can be sequentially rotated in the same rotational direction, for example clockwise in the figure, to different areas. It can be arranged so that it can be brought to a location and brought to different areas simultaneously.

The first area A1 is an area for attaching the panel part (3) to the panel holding means (23), and the second area A2 is an area for attaching the panel part (3) to the holding means (23). Clean air is blown against the panel section or holding means (
23) This is an air blowing area for removing and cleaning dust etc. adhering to objects immersed in electrodepositing solution in subsequent steps such as the electrode brush (27), and areas A3 and A4 respectively. First and second electrodeposition liquid tanks (21) and (22) containing electrodeposition liquid are arranged, and the fifth to ninth areas A5
~As have first to fifth cleaning tanks (41) to (4), respectively.
5) is placed. These first to fifth cleaning tanks (41)
A cleaning liquid such as isopropyl alcohol is stored in (45), and the cleaning liquid is circulated in a part of the cleaning tank or stirred by a magnetic stirrer or the like. Furthermore, the 0th and 11th areas AIO and AH are configured as dry areas. The last area A12 is an area where the panel portion (3) is removed from the panel holding means (23).

In such a configuration, the panel holding means (
On the holder (25) of 23), a conductive layer (8) for forming a fluorescent surface of the panel portion (3), that is, for electrodepositing a fluorescent material, is arranged facing toward the outer circumference.

Then, the panel holding means (23) is brought to area A2, and the panel part (3), the holding means (23) and the electrode brush (
27) Perform air blow treatment to remove deposits by blowing clean air onto the surface.

Next, the panel holding means (23) is brought to area A3, its support shaft (24) is lowered, and the panel portion (3) is immersed in the electrodeposition liquid in the electrodeposition liquid tank (21).

Thereafter, this is pulled up and the panel part (3) wetted with sufficient electrodeposition liquid is brought to the fourth area A4, and the support shaft (24) is lowered again to bring the panel part (3) into the fourth area A4. 3)
is immersed in the electrodeposition liquid in the second electrodeposition liquid tank (22). In this area A4, the ball is brought into contact with a protrusion (28A) provided protruding from the sleeve (28) of the holding means (23) as shown in FIG. 1 as the support shaft (24) descends. (35) is placed, the panel holding means (23) is brought to this area A4, and the support shaft (24) is lowered. At this time, the protrusion (28A) collides with the abutting ball (35), thereby causing the spring (34
) The sleeve (28) is lifted as shown by arrow a, and the rotating arm (26) is brought to the clockwise rotating position and the electrode brush (27) is moved against the panel. It is made to abut against the protrusion (8a) of the conductive layer (8) of the portion (3). Then, this second electrodeposition liquid [(2
2) is immersed with the electrode (36) shown in Figure 1, and this electrode (36) is used as the positive electrode, and the electrode brush (27) is connected to the electrode (36) as shown in Fig.
) is applied to perform the phosphor electrodeposition operation.

In this way, the inner surface of the panel part (3) is guided 'II! A phosphor is electrodeposited on the surface (8), that is, a fluorescent surface (9) is formed.

After this Denwakasaku l is finished, the support shaft (24
) is lifted 1, and at the same time as this lifting, the protrusion (28A) of the sleeve (28) is moved from the ball (35) to the butt.
The abutment of the sleeve (28) is released and the sleeve (28
) is supported by the support shaft (24) by the restoring force of the spring (34).
), and along with this, the rotating arm (2
6) is rotated counterclockwise, and the electrode brush (27) is separated from the protrusion (8a) of the conductive layer (8) of the panel part (3).

After the support shaft (24) is pulled up in this way and the panel part (3) is pulled up from the second electrodeposition liquid tank (22), it is moved to the fifth area A5 and the support shaft (24) is pulled up again. )
is lowered and the panel portion (3) is immersed in the cleaning liquid in the first cleaning tank (41) to be cleaned.

The support shaft (24) is lifted again to pull the panel part (3) out of the cleaning tank (41), and the same operation is repeated to sequentially clean the sixth to ninth areas AG-A9.

Thereafter, areas A1o and A1 are dried, respectively, and brought to area A12, where the panel portion (
3) is removed from its panel holding means (23).

In addition, in the above-mentioned butting, the pole (35) is in the fourth area A4.
As the support shaft (24) descends, it collides with the protrusion (28A) of the sleeve, as described above, and rotates the electrode brush (27).

The electrodeposition liquids contained in the first and second electrodeposition liquid tanks (21) and (22) may have the same composition.

This electrodeposition solution is After mixing and drying, It is possible to use an electrodeposition liquid prepared by mixing the liquid and dispersing it with ultrasonic waves.

The electrode (36) is composed of a flat metal plate made of a metal mesh plate or a metal plate with slits, long holes, circular holes, etc.
As shown in the figure, the panel part (3) is placed in the electrodeposition liquid (51).
At the same time, the electrode (36) is placed directly opposite the conductor (8) on which the phosphor electrodeposition of the panel portion (3) is to be performed, and the area of the electrode (36) is equal to or larger than that of the conductive layer (8). be selected. Alternatively, as shown in Figure 6, the electrode (36
) may be formed into a cylindrical shape, and the panel portion (3) may be inserted into the cylindrical electrode (36). Cylindrical electrode (3
6) can take various configurations, such as having its cylindrical wall section shaped like a mesh or a lattice, as shown in FIGS. 7 and 8.

Further, the above-mentioned electrode (36) may be made of platinum-plated titanium, for example.

The electrode brush (27) is made of thin metal wire (30
), and its tip is made to elastically contact the protrusion (8a) of the conductive N (8) of the panel part (3), but if the thin metal wire (30) is too thick, By repeated electrodeposition, the phosphor adheres to the protrusion (8
It is desirable to have a diameter of about 0.1w1 because it will obstruct electrical contact with a) and conversely, if it is too thin, the electrical connection will be insufficient. Furthermore, if the number of thin metal wires (30) is too small, there is a risk that the contact with the protrusion (8a) will be insufficient, so it has been found that it is better to select about 100 wires as described above.

In the above-described example, the phosphor electrodeposition on the panel part (3) is performed in 12 areas A1 to A12 as shown in FIG.
However, various changes can be made without being limited to the arrangement of these regions. For example, a configuration in which a plurality of electrodeposition liquid tanks are arranged as the preliminary electrodeposition liquid tank (21), In addition, various changes can be made to the cleaning tanks, such as arranging fewer or more cleaning tanks than the first to fifth ones.

〔Effect of the invention〕

As described above, in the present invention, the electrode (36) has a mesh shape or a shape with through holes through which the electrodeposition liquid can flow, so that the entrainment and circulation of the electrodeposition liquid can be prevented. This can be carried out well, and the transfer of the phosphor to the conductive layer (8) of the electrodeposited body is carried out well, thereby increasing the efficiency of electrodeposition. Furthermore, since the inconvenience that the presence of the electrode (36) obstructs the flow of the electrodeposited liquid is avoided, the area of the electrode (36) can be made as large as necessary, so that the conductive layer (8) can be made uniform over the entire area of the conductive layer (8), making each part uniform and high-quality even on a relatively large, for example, 4-inch fluorescent surface. can be formed with high efficiency.

The curve (91) in FIG. 9 shows the result when electrodeposition is performed to form a 4-inch fluorescent surface using a mesh electrode with a width of 100 mm and a height of 200 mm as the electrode (36) in the apparatus of the present invention. This shows the results of measuring the relationship between electrodeposition time and electrodeposition amount. Curve 10 (92) in the same figure is the curve when a simple plate-shaped electrode with a similar area and no through holes is used. (93) is a case where a 4-inch fluorescent surface was formed using an electrode plate with a width of 50 mm and a height of 150 mm that would form a conventional 2-inch fluorescent surface. In both cases, the electrodeposition voltage was 300 V and the distance between electrodes was 3 cm. As is clear from comparing these curves (91) to (93), according to the present invention, it takes about 12.5 seconds to electrodeposit the phosphor with a film thickness of 3.5 mg/cut. This can significantly improve efficiency.

As mentioned above, in the electrodeposition process of the phosphor, the first
Electrodeposition liquid [(21) In other words, when performing only a simple immersion work in the electrodeposition liquid in the preliminary electrodeposition liquid tank, immerse the panel part (3) or each part attached thereto in this electrodeposition liquid. Since air bubbles are effectively eliminated during the work of taking out the object, that is, through contact with the electrodeposition liquid, almost no air bubbles are generated when immersed in the original electrodeposition liquid in the second electrodeposition liquid bath (22). This effectively prevents defects from occurring on the formed fluorescent surface, resulting in defective products and deterioration in quality. In addition, by immersing the electrodeposited material in the preliminary or first electrodeposition liquid, the electrodeposited object including the panel portion (3) etc. is pre-wetted and accommodated in the original electrodeposition liquid. When the panel part (3) and the electrode brush (27) are pulled out after the electrodeposition process,
, a weight loss due to removal of the electrodeposited liquid as the immersed object such as the holding means (23) of the panel portion (3) is pulled out, and further a change in composition.

Since wear and tear such as staining is effectively avoided and the electrodeposition liquid (22) can be used repeatedly, the number of times the electrodeposition liquid must be refilled is reduced, and the number of work stoppages for this replenishment is reduced. This improves mass productivity.

[Brief explanation of the drawing]

1 and 6 are respective configuration diagrams of the device of the present invention, FIG. 2 is a layout diagram of an example of the device of the present invention, FIG. 3 is a side view of the panel holding means in one state, and FIG. 4 5 is a front view of an example of an electrode brush, FIG. 5 is an inner view of the panel part, FIGS. 7 and 8 are perspective views of the electrode, respectively, FIG. 9 is a measurement curve diagram of electrodeposition time vs. electrodeposition amount, and FIG. FIG. 10 is a perspective view of an example of a cathode ray tube to which the present invention can be applied, FIG. 11 is a longitudinal sectional view thereof, FIG. 12 is an exploded perspective view, FIG. 13 is a measurement curve diagram of electrodeposition voltage vs. electrodeposition amount, FIG. 14 is a measurement curve diagram of distance between electrodes versus amount of electrodeposition, and FIG. 15 is a measurement curve diagram of electrodeposition time versus amount of electrodeposition. (3) is a panel part, (8) is a conductive layer, (9) is a fluorescent surface,
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Claims (1)

[Scope of Claims] An electrodeposition liquid tank containing a fluorescent electrodeposition liquid, a mesh-shaped through-hole perforated electrode immersed in the electrodeposition liquid in the electrodeposition liquid tank, and an electrodeposition power source. The panel portion having a conductive layer deposited on a predetermined portion of the inner surface is immersed in the electrodeposition liquid, and the electrodeposition power supply is connected between the conductive layer and the electrode to increase the conductivity of the panel portion. A phosphor electrodeposition device characterized in that the phosphor electrodeposition is performed on a layer.