JPS6150891B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of forming a conductive layer on glass, and particularly to a method of forming a conductive layer on the surface of a curved optical lens, for example.

For example, in a cathode ray tube such as a projection type cathode ray tube that has an optical lens built into the tube, when a charging phenomenon occurs in the optical lens, the potential distribution in the vicinity changes, causing disturbances in the electronic system. In projection type cathode ray tubes and the like, problems occur such as disturbing the trajectory of the electron beam and secondary distortion of the projected image. For this reason, efforts have been made to form a conductive film on such optical lenses to remove unnecessary charges.

FIG. 1 is an example of a sectional view of a meniscus lens used in a projection type cathode ray tube in which the above-mentioned optical system is provided. A meniscus lens 1 made of glass has a bowl shape, has a convex surface 2 and a concave surface 3, and further has a through hole 4 in its center.
An electron beam target (not shown) having a convex fluorescent surface is disposed in the through hole 4. The fluorescent surface of this target is oriented upward in the figure. Then, this fluorescent surface (not shown) is scanned by the electron beam, and at this time, scattered electrons and secondary electrons of the electron beam flow into the convex surface 2 of the mechanical lens 1. Therefore, a charging phenomenon occurs on the convex surface 2, and the potential distribution near the fluorescent surface is slightly disturbed. Therefore, this unnecessary potential distribution distorts the trajectory of the electron beam, causing distortion in the primary image formed on the fluorescent surface.

In order to avoid such drawbacks, a conductive film has conventionally been formed on the side of the meniscus lens 1 from which the electron beams come, that is, on the convex surface 2, to eliminate unnecessary inflow of electrons. This type of conductive film needs to be optically transparent and strong enough not to be easily peeled off, and is usually made of indium vacuum-deposited under high-temperature heating. However, since the meniscus lens 1 has a bowl-shaped shape, it is necessary to gradually raise the temperature when performing vacuum evaporation under high-temperature heating, and to lower the temperature after the evaporation. If you do not do this gradually, the lens itself may become distorted, or worse, it may break. Further, unless the shape of the heat source for heating is bowl-shaped, it is difficult to raise the temperature evenly, and this fact also becomes a constraint that the temperature must be raised and lowered slowly. moreover,
When it is intended to place a plurality of mechanical lenses 1 in a vacuum chamber (or vacuum container) and perform vacuum deposition at the same time, it is even more difficult to arrange a heat source so as to raise the temperature evenly.

In this way, in order to vacuum-deposit a convex or concave optical lens such as the meniscus lens 1 in a high-temperature atmosphere, firstly, it requires a long working time, and secondly, it is difficult to provide a heating source. Thirdly, there is a drawback that it is difficult to deposit a plurality of layers at the same time.
Furthermore, due to the specificity of the shape, fourthly, it is difficult to form a uniform vapor deposited film on a curved surface or arrange a vapor deposition source so as to form a uniform vapor deposited film. In particular, it is extremely difficult to form a uniform deposition film on a plurality of optical lenses at the same time or to arrange a deposition source to do so.

In order to overcome these drawbacks, recently developed coating methods have been known in which a strong thin film is formed using a sputtering method or an ionization plate method, that is, an ion plating method. These methods require that the object to be coated be a conductor such as a metal, and it is essentially impossible to coat an insulator such as glass, and even if it is possible, special devices such as the vapor deposition source are required. There are some limitations, such as the need for the coating and the need to take special measures to the shape of the object to be coated.

Therefore, the main object of the present invention is to provide a method for easily forming a conductive layer on glass, which eliminates the above-mentioned drawbacks and limitations at once.

In summary, the present invention includes a first step of forming a porous preliminary conductive film on a glass surface by vacuum evaporation or spraying, and a second step of forming a porous preliminary conductive film on a glass surface by ion plating using this preliminary conductive film as an electrode. This is a method for forming a strong conductive layer on the glass surface layer, which comprises a second step of forming a second conductive film, and a third step of removing the preliminary conductive film after the second step.

The above objects and other objects and features of the present invention will become more apparent from the detailed description given below with reference to the drawings.

A method according to an embodiment of the present invention will be explained by dividing it into three steps, taking as an example a meniscus lens used in a projection type cathode ray tube shown in FIG.

First, in the first step, aluminum is vacuum-deposited on the convex surface 2 of the meniscus lens 1. The vapor deposited film thus obtained is a preliminary conductive film as the first conductive film. This deposition may then be a conventional, well-known vacuum deposition method. Moreover, it is preferable that the preliminary conductive film formed here is porous, and porous vapor-deposited films have the advantage that they do not need to be vacuum-deposited under heating and can be produced extremely easily and in a short time at low vacuum degrees. have.

In the second step, the meniscus lens 1 coated with the preliminary conductive film obtained in the first step is coated with indium by an ion plating method. FIG. 2 is an illustrative diagram for explaining this method. A meniscus lens 1 coated with a preliminary conductive film 5 is housed in a bell gear 6,
Its convex surface 2 is placed opposite the indium evaporation source 7 . The - (minus) side of the DC high voltage power supply 8 is connected to the preliminary conductive film 5 of the meniscus lens 1.
The + (plus) side is connected to a part of the evaporation source 7.
It is connected to one of the heater lead wires 9 of. In such a configuration, the exhaust system is operated to exhaust the inside of the bell gear 6, and then an inert gas such as argon is introduced. Then, in this atmosphere, the evaporation source 7
Apply electricity to evaporate the indium. The evaporated indium is ionized and accelerated by the electric field formed by the high voltage applied to the preliminary conductive film 5, resulting in an ion flow 1 as shown in the lines shown in FIG.
0 and hits the meniscus lens 1. At this time, the indium ions penetrate the preliminary conductive film 5 and penetrate below the convex surface 2 of the meniscus lens 1 due to impact energy due to the acceleration of the electric field. High voltage power supply 8
The electric field (or electric field lines) formed by the evaporation source enters the convex surface of the meniscus lens 1 at right angles. The ionized indium is accelerated along the direction of this electric field and impinges uniformly on the convex surface at right angles as an ion stream 10. In this way,
There is an advantage that there is no need to specially devise the shape of the evaporation source 7. Furthermore, since indium has penetrated into the convex surface 2 of the meniscus lens 1 and is not attached to the outer surface, a strong conductive layer is formed. Furthermore, unlike the conventional method, there is no need for any thermal process, so the conductive layer can be formed in an extremely short time. In this embodiment, one meniscus lens 1 is shown mounted inside the bell gear 6, but if a plurality of meniscus lenses 1 can be stored in the space inside the bell gear 6, many meniscus lenses 1 can be placed at the same time. On the other hand, it is also extremely easy to form a conductive layer.

As mentioned in the first step, the preliminary conductive film 5 is
It is desirable that the material be porous so that indium ions can easily penetrate therethrough. If such a porous thin film is conductive, indium can easily penetrate into the convex surface 2 without significantly impairing the impact energy, and has the advantage of forming a stronger conductive layer. .

Next, move on to the third step. In the third step, the meniscus lens 1, which has already been ion-plated with indium, is subjected to chemical treatment to dissolve and remove the preliminary conductive film 5 formed in the first step. This chemical treatment is carried out with an alkaline solution, for example sodium hydroxide solution (NaOHaq.). As is well known, since the preliminary conductive film is made of aluminum, it is easily dissolved. Moreover, this dissolution can be performed extremely easily. The indium implanted into the convex surface 2 is not directly affected by this chemical treatment since it is within the glass structure. Furthermore, since indium does not dissolve in alkali, it has no effect on the second conductive film.

This method of forming the conductive layer of a meniscus lens does not require a long thermal process during vacuum deposition as in conventional methods, and there is no need to consider the shape or arrangement of the evaporation source. be.

In the above embodiments, the preliminary conductive film was formed by vacuum evaporation of aluminum, but the material of the preliminary conductive film is not limited to aluminum.
Further, the method for forming the preliminary conductive film is not limited to the vacuum deposition method, and may be formed by, for example, a spray method using a conductive substance.

Further, in the above embodiments, an optical lens having a curved surface shape such as a meniscus lens was particularly described, but the optical lens is not limited to this, and it goes without saying that a flat glass may be used. Furthermore, the metal forming the conductive layer brought into the glass structure by ion plating is not limited to indium, and may be, for example, gold or chromium depending on the purpose.

As described above, according to the present invention, a preliminary conductive film is formed on glass, and then a conductive material layer is formed on the surface of the glass by ion plating using the preliminary conductive film as an electrode. Since the conductive layer is formed by removing the film, it has the advantage that it can be done in a much shorter time and more easily than in the past. The conductive glass obtained by this method is therefore also inexpensive. Another advantage is that there is no need to make any special efforts or considerations to the manufacturing equipment used in the method of the present invention.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an example of a meniscus lens built into a projection type cathode ray tube, which is the background of the present invention. FIG. 2 is an illustrative diagram of an apparatus for explaining one embodiment of the present invention. In the figures, the same reference numerals indicate the same or corresponding parts, 1 is a meniscus lens, 2 is a convex surface of the lens, 5 is a preliminary conductive film, 7 is an evaporation source, and 8 is a high voltage power source.

Claims (1)

[Scope of Claims] 1. A step of forming a preliminary conductive film on the surface of glass, a step of forming a conductive layer by an ion plating method using the preliminary conductive film as one electrode, and removing the preliminary conductive film. A method of forming a conductive layer on glass, the method comprising: 2. The method for forming a conductive layer on glass according to claim 1, wherein the preliminary conductive film is formed by a vacuum evaporation method. 3. The method for forming a conductive layer on glass according to claim 1, wherein the preliminary conductive film is formed by a spray method. 4. Claims 1 to 3, wherein the preliminary conductive film is formed as a porous conductive film.
A method of forming a conductive layer on the glass according to any one of the above.