JPH05234540A - Transmitting type flat cathode-ray tube and its manufacture - Google Patents

Abstract

PURPOSE:To facilitate the high voltage application to the phosphor screen of a transmitting type flat cathode-ray tube with a simple structure. CONSTITUTION:In a transmitting type flat cathode-ray tube having a flat glass tube body formed in a three-body structure consisting of a screen panel, a back pattern, and a funnel part having a neck part, a phosphor film 19 is formed on the inner surface of a screen panel 11 by electrodeposition through a transparent conductive film, and an exposed part 20 on which no phosphor film 19 is adhered is provided on the transparent conductive film. The exposed part 20a of the transparent conductive film is electrically connected to the internal carbon film 23 of a funnel part 14 through a conducting carbon film 25.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmission type flat cathode ray tube and a method for manufacturing the same.

[0002]

2. Description of the Related Art As shown in FIG.
There is known a reflection type flat cathode ray tube 6 in which a flat glass tube body 5 is constituted by a three-body structure of a front panel 2 and a funnel portion 4 having a neck portion 3. That is, the flat glass tube body 5 is joined to the screen panel 1 and the front panel 2 facing each other by frit so as to form a flat space 7 between them, and also to one side thereof by frit. The funnel portion 4 and the neck portion 3 welded to the opening end of the funnel portion 4 on the small diameter side. The electron gun 8 is arranged in the neck portion 3.

A fluorescent screen 9 is formed on the inner surface of the screen panel 1 via a reflective film (not shown) made of, for example, an aluminum vapor deposition film, and an electron beam e emitted from an electron gun 8 is directed onto the fluorescent screen 9. An optical image that is horizontally and vertically scanned and excited and emitted by the electron beam e is observed from the front panel 2 side facing the screen panel 1. In this reflective flat cathode ray tube 6, the front panel 2
A filter (not shown) for reducing the light transmittance is arranged on the flat outer surface to improve the contrast.

[0004]

On the other hand, a transmission type flat cathode ray tube using a flat glass tube having a three-body structure of a screen panel, a back panel and a funnel portion having a neck portion has been developed. In a transmissive flat cathode ray tube, a transparent conductive film such as ITO is formed on the inner surface of the screen panel.
A phosphor screen is formed through an (Indium Tin Oxide) film, an electron beam from an electron gun is horizontally and vertically scanned on the phosphor screen, and an optical image excited and emitted by the electron beam is observed from the screen panel side. It

By the way, in such a transmissive flat cathode ray tube, it is necessary to apply a high voltage, that is, an anode voltage to the fluorescent screen inside the screen panel.
It is desirable that the voltage can be applied with a simple structure.

In view of the above points, the present invention provides a transmission type flat cathode ray tube in which high voltage can be easily applied to the phosphor screen. The present invention also provides a method of manufacturing a transmission type flat cathode ray tube for that purpose.

[0007]

A transmission type flat cathode ray tube according to the present invention has a flat tube body 15 having a screen panel 11, a back panel 12 and a neck portion 13.
4 and a phosphor film 19 is formed on the inner surface of the screen panel 11 via a transparent conductive film 20. An exposed portion where the phosphor film 19 is not adhered to the transparent conductive film 20. 20a is provided, and the exposed portion 20 of the transparent conductive film 20 is provided.
a and the inner conductive film 23 formed on the inner surface of the funnel portion 14
And are electrically connected.

Further, the present invention is a method of manufacturing a transmission type flat cathode ray tube using a flat tube body 15 formed of a three-body structure of a screen panel 11, a back panel 12 and a funnel portion 14 having a neck portion 13. In, the transparent conductive film 20 is adhered to the inner surface of the screen panel 11, and the phosphor electrodeposition pattern mask 34 also serving as a lead electrode is adhered on a portion of the transparent conductive film 20 near the funnel portion 14 side. The phosphor film 19 is deposited on the transparent conductive film 20 by an electrodeposition method so that the transparent conductive film 20a corresponding to the pattern mask 34 is exposed.

[0009]

In the transmission type flat cathode ray tube 26 of the present invention,
A phosphor film 19 is formed on the inner surface of the screen panel 11 via a transparent conductive film 20, and an exposed portion 20a where the phosphor film 19 is not formed is provided on the transparent conductive film 20. The exposed portion 20a and the funnel portion are provided. By applying, for example, a conductive film 25 for conduction and electrically connecting the interior conductive film 23 in 14 to which a high voltage is applied, high voltage can be easily applied to the phosphor screen.

In forming the fluorescent screen, the transparent conductive film 20 is deposited on the inner surface of the screen panel 11, and the fluorescent electrodeposition pattern mask 34 is formed on a portion of the transparent conductive film 20 near the funnel portion 14 side. Adhere to the transparent conductive film 2
By depositing the phosphor film 19 on the transparent conductive film 20 by electrodeposition, the phosphor film 19 is not attached to the portion of the transparent conductive film 20 corresponding to the pattern mask 34, and the inner conductive film in the funnel portion 14 is not attached. The exposed portion 20a for establishing electrical continuity with 23 is automatically formed in the electrodeposition process of the phosphor screen.

[0011]

Embodiments of the present invention will be described below with reference to the drawings.

In this example, as shown in FIG. 8, the screen panel 11, the back panel 12, and the neck portion 13 are integrally formed of a three-piece structure glass of a funnel portion 14, and these three members are frit-attached and flattened. The glass tube body 15 is configured. The screen panel 11 is formed into a curved surface such that the horizontal direction H is flat and the vertical direction V orthogonal to the horizontal direction H has a predetermined curvature as shown in FIG. Then, FIG. 1 and FIG.
As shown in FIG. 4, a fluorescent screen, that is, a fluorescent film 19 is formed on the inner surface of the screen panel 11 via a transparent conductive film, for example, the ITO film 20, and the electron gun 1 is provided in the neck portion 13.
9 is arranged. The anode voltage H is applied to the funnel portion 14.
A high-voltage anode button 21 for applying V is embedded, and an inner conductive film, for example, an inner carbon film 23 (see FIG. 3), which is connected to the anode button 21 on the inner surface of the funnel portion 14.
(See reference) is deposited.

On the other hand, in order to apply the anode voltage HV to the phosphor screen, the anode voltage HV is applied to the ITO film 20 from the internal carbon film 21 of the funnel portion 14 via the conducting carbon film 25. .. In this case, as shown in FIG. 3, an exposed portion 20a that is exposed without depositing the phosphor film 19 is formed on a part of the ITO film 20 at the end portion close to the funnel portion 14 side. The conductive carbon film 25 is applied so as to extend across the interior carbon film 23 of the funnel portion 14 to electrically connect the ITO film 20 and the interior carbon film 23.

The phosphor film 1 is formed on the inner surface of the back panel 12.
9. A conductive film, for example, a carbon film 24 is formed on almost the entire surface so as to face 9 and the carbon film 24 and the internal carbon film 23 on the inner surface of the funnel portion are formed by, for example, a conductive carbon film (not shown). Connect and carbon film 24
The anode voltage HV can be applied to.

Further, in the present invention, as shown in FIGS. 7A and 7B, the screen panel 11 is formed of glass 27 having a low transmittance. Examples of the low-transmittance glass 27 include gray glass (light transmittance of 73% based on EIAJ standard).
65.64%), Taint glass (light transmittance 56.8% according to EIAJ standard), Dark Taint glass (EIA
For example, the light transmittance according to the J standard of 42%) can be used. The light transmittance of normally used clear glass is 86%. The thickness of the screen panel 11 is, for example, 3 mm to 4 mm in the case of a 4-inch transmission flat cathode ray tube, that is, the central portion of the screen panel 11 has a thickness of about 3 mm, and the upper and lower portions have a thickness of about 4 mm. .. The 3-inch type can have a thickness of 2.5 mm to 3 mm.

The ITO film 20 on the side of the phosphor film 19 described above.
In order to apply the conducting carbon film 25 for electrically connecting to the internal carbon 23 on the funnel portion 14 side, the exposed portion 20a where the phosphor film 19 is not attached is formed on a part of the ITO film 20. I won't.

A method of forming a fluorescent screen in consideration of this point will be described below.

FIG. 5 shows a phosphor electrodeposition apparatus 30. In the figure, reference numeral 31 denotes an electrodeposition liquid tank containing a phosphor electrodeposition liquid 32. The electrodeposition liquid 32 is formed of a suspension of ionized phosphor.

As the electrodeposition liquid 32, for example, an electrodeposition liquid prepared by ultrasonically dispersing a mixture of a phosphor, indium oxide, aluminum nitrate and lanthanum nitrate with pure water, isopropyl alcohol and glycerin can be used.

An ITO film 20 is formed on the inner surface of the electrodeposition liquid 32.
The screen panel 11 on which the
A portion of the film 20 corresponding to the end on the funnel portion side, that is, a portion 20a to be exposed, is also provided with a conductive holding body (also serving as a lead electrode) 33 of the screen panel 11 so as to also serve as a lead electrode. Body wear pattern mask 3
4 is brought into contact. The ITO film 20 becomes an electrodeposited electrode.
A counter electrode 36 is disposed facing the ITO film 20, and an electrodeposition power source S is connected between the ITO film 20 and the counter electrode 36.

The electrodeposition pattern mask 34 is made of a conductive non-woven fabric made of, for example, metal or the like in a strip shape.
While being brought into contact with the portion 20a of the O film 20, a metal plate 35 is applied onto the electrodeposition pattern mask 34 and is sandwiched and held by a conductive holder 33.

Then, with the counter electrode 36 as the positive electrode side, current is applied between the counter electrode 36 and the ITO film 20 connected to the electrodeposition pattern mask 34, and the fluorescent electrodeposition work is performed. In this way, the phosphor film 19 is electrodeposited on the ITO film 20 on the inner surface of the screen pattern 11, that is, the phosphor screen is formed.

After the electrodeposition work is completed, the screen panel 11 is taken out. As shown in FIG. 6A, a part of the screen panel 11 is formed on the ITO film 20 in the center of the end portion near the funnel portion side. The phosphor film 19 is adhered and formed, leaving the exposed portion 20a to which the phosphor is not attached.

The phosphor electrodeposition pattern mask 34 may have various shapes, for example, a shape that covers the entire funnel side end portion of the screen panel 11 or a frame shape that surrounds the effective screen. For example, if a frame-shaped electrodeposition pattern mask that surrounds the effective screen is used, the phosphor film 19 is formed only on the effective screen 38 as shown in FIG. 6B. Therefore, the ITO film 20 around it is exposed, and naturally, the portion 20a to which the conductive carbon film 25 is applied is naturally formed.
Will be exposed.

The transmission type flat cathode ray tube 26 having the above-mentioned structure
According to the above, the phosphor film 19 is formed on the inner surface of the screen panel 11 via the transparent conductive film, for example, the ITO film 20, and at least at the end portion close to the funnel side,
By forming an exposed portion 20a where the phosphor film 19 is not adhered to a part of the ITO film 20, the exposed portion 2 of this ITO film is formed.
0a and the interior carbon film 23 in the funnel portion 14 to apply the conducting carbon film 25 to give the anode voltage HV to the phosphor film 19 through the interior carbon film 23-conducting carbon film 25-ITO film. .. Therefore, it is possible to easily apply the anode voltage to the so-called fluorescent screen.

On the other hand, in the phosphor electrodeposition step of forming the phosphor film 19 on the ITO film 20 by electrodeposition, as shown in FIG. 5, the phosphor electrodeposition pattern mask 34 also serving as the lead electrode is formed.
By performing the electrodeposition work using, it is possible to form a part of the ITO film 20 on which the phosphor film 19 is not electrodeposited. Therefore, the conductive carbon film 25 should be applied by placing this mask in contact with the portion to which the conductive carbon film 25 for supplying the anode voltage 34 is applied.
The exposed portion 20a of the TO film can be formed simultaneously with electrodeposition of the phosphor film 19.

Incidentally, when the phosphor is electrodeposited on the ITO film 20, the phosphor is attached to the entire surface of the ITO film 20.
Therefore, it has been considered that the phosphor is usually electrodeposited on the entire surface and then the phosphor of the necessary portion 20a is wiped off. However, such a method requires a large number of manufacturing steps and is wiped off. Further, the phosphor adheres to other parts, or the phosphor at the edge portion of the wiping off is easily peeled off, and the phosphor falls off after completion of the flat cathode ray tube and becomes a stray source, which causes an increase in defective rate. However, in this embodiment, there is no such concern. In particular, the ITO film portion 20
Since the phosphor is not electrodeposited on a from the beginning, the wiping step is eliminated. In addition, defects due to falling of the phosphor and trimming errors can be eliminated, and the yield is greatly improved. Furthermore, since the phosphors can be electrodeposited only on the necessary parts, the wasteful phosphors can be reduced and the cost can be reduced accordingly.

Further, by making the shape of the electrodeposition pattern mask 34 into a frame shape corresponding to the invalid screen portion, the phosphor film 19 is electrodeposited only on the effective screen as shown in FIG. 6B. It will be. Therefore, it is not necessary to provide a frame-shaped shield for masking the ineffective screen on the screen panel 11 side after completing the transmission type flat cathode ray tube.

Since a transparent conductive film such as an ITO film is easily scratched, damage to the transparent conductive film can be avoided by using a conductive non-woven fabric as the electrodeposition pattern mask 34.

On the other hand, in the above-mentioned structure, the screen panel 11 is formed by using the glass 27 having a low light transmittance, so that the contrast can be improved without using the conventional filter whose light transmittance is suppressed. .. For example, when using a flat filter, the screen panel 11
Since it is formed of a curved surface, the screen panel 11
Spaces are formed at irregular intervals between the filter and the filter, which causes a sense of discomfort in terms of viewing angle. Further, it is conceivable to use a curved surface filter, but using such a filter inevitably results in high cost. On the other hand, by reducing the glass transmittance of the screen panel 11 without using a filter, the cost can be improved and the contrast can be improved.

Further, by forming the screen panel 11 with the low-transmittance glass 27, for example, it is possible to reduce the reflection of external light at the interface between the screen panel 11 and the fluorescent surface. It can be improved.

As the glass material forming the screen panel 11, gray glass and taint glass are particularly preferable in consideration of the contrast ratio and the brightness.

When the carbon film 24 to which the anode voltage is applied is formed on the inner surface of the back panel 12, the inside of the flat space 17 is in a so-called no electric field state, and the electron beam emitted from the electron gun 18 is electromagnetic. The fluorescent film 19 is horizontally and vertically scanned only by the deflection by the deflecting means, the trajectory shift of the electron beam is eliminated, and the generation of the pseudo signal is avoided. If the carbon film 24 is not formed, the inner surface of the back panel 12 is charged with a negative charge by the electron beam, and due to the negative charge, the trajectory of the electron beam is deviated especially on the upper side of the screen, and the image is folded or whitened. (Tailing) A pseudo signal such as noise is generated. However, such a defect can be avoided by forming the carbon film 24 to which the anode voltage is applied on the inner surface of the back panel 12 as in the present embodiment.

[0034]

According to the present invention, it is possible to easily apply a high voltage to the fluorescent surface of the transmission type flat cathode ray tube with a simple structure.

Further, according to the present invention, when the phosphor film is formed on the inner surface of the screen panel by electrodeposition, the phosphor is deposited on a part of the transparent conductive film by electrodeposition through the electrodeposition pattern mask. It is possible to form an unattached portion, that is, an exposed portion for applying a conductive film for applying a high voltage. Therefore,
A transparent flat cathode ray tube can be manufactured with good yield.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an example of a transmission type flat cathode ray tube according to the present invention.

FIG. 2 is a perspective view showing an example of a transmission type flat cathode ray tube according to the present invention.

FIG. 3 is a plan view of a main part of a transmission type flat cathode ray tube according to the present invention.

FIG. 4 is a cross-sectional view of a fluorescent screen.

FIG. 5 is a configuration diagram showing an example of a phosphor electrodeposition apparatus according to the present invention.

FIG. 6 is a plan view of a screen panel having a phosphor screen formed by the phosphor electrodeposition method of the present invention.

FIG. 7 is a perspective view of a screen panel according to the present invention.

FIG. 8 is an exploded perspective view showing an example of a flat glass tube body having a three-body structure according to the present invention.

FIG. 9 is a cross-sectional view of a conventional reflective flat cathode ray tube.

[Explanation of symbols]

 1,11 Screen panel 2 Front panel 3,13 Neck part 4,14 Funnel part 5,15 Flat glass tube 6 Reflective flat cathode ray tube 12 Back panel 7,17 Flat space 8,18 Electron gun 9,19 Fluorescent screen ( Fluorescent substance film) 20 Transparent conductive film (ITO film) 20a Exposed part 21 Anode button 23 Internal carbon 24 Carbon film 25 Conducting carbon film 26 Transparent flat cathode ray tube 30 Fluorescent substance electrodeposition device 31 Electrodeposition tank 32 Electrodeposition liquid 33 Holder 34 Phosphor electrodeposition pattern mask 35 Metal plate S Power supply

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masahiro Kikuchi 6-735 Kitashinagawa, Shinagawa-ku, Tokyo Sony Corporation

Claims (2)

[Claims] 1. A flat tubular body is formed of a three-body structure including a screen panel, a back panel and a funnel portion having a neck portion, and a phosphor film is attached to the inner surface of the screen panel via a transparent conductive film. The transparent conductive film is provided with an exposed portion not covered with the phosphor film, and the exposed portion of the transparent conductive film and the inner conductive film of the funnel portion are electrically connected to each other. Cathode ray tube. 2. A transparent conductive film is deposited on the inner surface of the screen panel, and a phosphor electrodeposition pattern mask also serving as a lead electrode is adhered onto a portion of the transparent conductive film close to the funnel portion side, and the pattern is formed. A method of manufacturing a transmissive flat cathode ray tube, which comprises depositing a phosphor film on the transparent conductive film by an electrodeposition method so that the transparent conductive film in a portion corresponding to the mask is exposed.