JPH10199415A - Forming method for internal film of cathode-ray tube front panel, and device therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a higher quality film suitable for cathode-ray tube functions by optimizing a film thickness during formation of an internal film of a cathode- ray tube front panel. SOLUTION: In a film formation by applying a liquid material 30 to an internal surface of a cathode-ray tube front panel 10, this method includes the following processes, (a), (b), (c1) and (d): (a) A liquid material 30 is supplied to an internal surface of a front panel 10. (b) The front panel 10 is rotated in the direction parallel to its surface to form a liquid film 32 of the liquid material 30 throughout the front panel 10. (c1) Excessive liquid material is sucked through a suction port 42 or the like at an outer corner of the front panel 10. (d) The liquid film 32 is dried up by a heater 60 or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for forming an inner surface film of a front panel of a cathode ray tube, and more particularly to a method of applying a liquid material such as a fluorescent material to the inner surface of a front panel constituting a front portion of the cathode ray tube. The present invention relates to a method for forming a film such as a film and an apparatus used for the method.

[0002]

2. Description of the Related Art As a structure of a cathode ray tube, a neck portion accommodating an electron gun and the like and a funnel portion extending in a funnel shape at the tip of the neck portion are constituted by one glass member. There is a front panel provided with a surface, and has a structure in which a funnel portion and a front panel are joined to assemble a CRT.

The shape of the front panel is a flat rectangular shape and the whole is gently curved from the center to the outer periphery. The outer peripheral edge is bent inward to form a frame and serves as a joint surface with the funnel portion. A fluorescent material is applied and dried on the curved inner surface of the front panel, and is further cured to provide a fluorescent film. Various coating films other than the fluorescent material may be formed on the inner surface of the front panel.

[0004] As a method of forming a film on the inner surface of the front panel, a liquid material for forming a film is supplied to the inner surface of the front panel, and then the front panel is rotated at a high speed in parallel with the surface so that the film is rotated. There is a method in which the liquid material is uniformly spread over the entire surface by the accompanying centrifugal force. According to this method, a thin and uniform film can be formed quickly. 2. Description of the Related Art In recent years, the screen size of TV receivers has been increasing, and it has been demanded to provide a large-sized CRT with excellent image quality. Large CRTs require large front panels.

[0005]

In the method of applying a liquid material using the centrifugal force described above, it is difficult to control the film thickness.
There was a problem that a high quality film could not be produced. Especially,
This problem is significant for large-area front panels. Specifically, there is a problem that the liquid material supplied to the inner surface of the front panel accumulates on the outer peripheral portion of the front panel, and the thickness of this portion locally becomes excessively large. When the front panel is rotated, the liquid material tends to move to the outer peripheral side, but the movement of the liquid material is blocked by the frame-shaped portion existing on the outer peripheral edge of the front panel. As a result, the liquid material accumulates in the outer peripheral edge portion.
In particular, since the liquid material gathers from the entire outer periphery on both sides at the four corners of the outer periphery, it becomes a large pool of liquid material. In order to reliably and quickly spread the liquid material over the entire surface of the front panel, it is necessary to supply an excessive amount of the liquid material to an extent necessary for film formation. As a result, extra liquid material inevitably accumulates on the outer periphery of the front panel, particularly on the corners. If the thickness of the fluorescent film becomes excessively large at the outer peripheral corner of the front panel, for example, the characteristics such as the luminance distribution are locally distorted near the outer peripheral corner of the screen or the image quality deteriorates on the screen of the TV receiver. .

[0006] Further, supplying the excess liquid material causes another problem. That is, the liquid material accumulated in the outer peripheral corner of the front panel scatters outside the outer peripheral frame of the front panel by further applying a centrifugal force. Under conventional ordinary working conditions, 3 to 4 times compared to the amount of liquid material necessary for film formation.
Since a very large amount of liquid material was supplied to form a film quickly and reliably, the amount of liquid material scattered outside beyond the outer peripheral frame of the front panel is considerably large. The splattered liquid material adheres to and contaminates peripheral devices and the like. If a part of the scattered liquid material falls on the film formed on the inner surface of the front panel and re-adheres, spot-like defects occur in the film. If a part of the liquid material exceeding the outer peripheral frame remains attached to the end face of the outer peripheral frame, the joining surface when the front panel is joined to the funnel portion is contaminated with the liquid material, and sufficient joining cannot be performed. In order to remove the liquid material from the bonding surface, operation steps such as polishing and cleaning are required. Furthermore, since the material such as the fluorescent film is quite expensive, if the liquid material scatters and dries, it is difficult to recover and regenerate, resulting in a large economic loss.

There is another problem. In other words, it was thought that if the liquid material was spread using centrifugal force, a substantially uniform film thickness could be obtained on the entire front panel, but actually, the film thickness was determined by the distance from the rotation center. It has been found that undesirable bias occurs. This is because the centrifugal force applied to the liquid material increases as the turning radius increases,
The liquid material at a position far from the center of rotation is stretched to the outer peripheral side by a large force and becomes thinner, whereas the liquid material at a position near the center of rotation is applied with a small centrifugal force, so that it is not much stretched. It remains thick. Therefore, the film thickness is large in the middle of the front panel and becomes thinner toward the outer periphery.

For example, in the case of a fluorescent film, the light generated becomes weaker as the film thickness becomes smaller, so that the screen of the cathode ray tube has a darker outer peripheral portion and lower image quality than the central portion. Moreover, in the cathode ray tube, the electron beam emitted from the central neck portion is deflected and hits the fluorescent film on the inner surface of the front panel to generate light. Since the deflected electron beam has a longer distance to reach the fluorescent film and consumes energy due to the deflection, the energy given to the fluorescent film is reduced and the light generated by the fluorescent film is weakened. as a result,
Light generated by the fluorescent film tends to be weaker in the outer peripheral portion than in the central portion of the front panel.

Since the effect of such electron beam deflection and the effect of the film thickness distribution due to the action of the centrifugal force are synergistically added, the difference in screen brightness or image quality between the central portion and the outer peripheral portion of the cathode ray tube. Becomes extremely large. Since the problems described above become more pronounced in a large-screen CRT, improvement has been demanded.

An object of the present invention is to obtain a high-quality film exhibiting uniform luminance characteristics and the like suitable for the function of a cathode-ray tube by making the film thickness appropriate when forming the inner surface film of the front panel of the cathode-ray tube. It is.

[0011]

Means for Solving the Problems In the present invention, claim 1 is provided.
The invention described in (1) is a method of forming a film by applying a liquid material to the inner surface of the front panel of the cathode ray tube, the following (a) (b) (c
1) Includes step (d). (a) A step of supplying a liquid material to the inner surface of the front panel. (b) rotating the front panel in parallel with its surface to form a liquid film of the liquid material on the entire surface of the front panel.

(C1) A step of sucking excess liquid material at the outer peripheral corner of the front panel. (d) drying the liquid film. Each component requirement will be specifically described. CRT front panel CRTs are used for various ordinary uses such as for TV receivers and computer displays. The front panel has the same structure as the front panel used for a normal cathode ray tube. Basically, a panel surface formed from a glass material and having a substantially rectangular shape,
An outer peripheral frame is provided on the outer periphery of the panel surface, the outer peripheral frame being bent in a direction substantially perpendicular to the panel surface.

Liquid material This is a material for forming various films provided on the inner surface of the front panel, and various inorganic or organic materials are used. Specifically, there is a liquid material for forming a fluorescent film or a protective coating film. The liquid material may be a liquid or a viscous paste.
In the case of a cathode ray tube of a color TV receiver, fluorescent films for at least three colors are formed on the inner surface of the front panel.

The liquid material preferably has properties such as viscosity or fluidity and film forming properties suitable for supply and formation of a liquid film. Specifically, those having a viscosity of about 10 to 50 cps are preferable. The liquid material loses fluidity upon drying. The dried liquid film can be further cured. Usually, an ultraviolet curable liquid material is used, but a curable liquid material such as a reaction curable type or a heat curable type may be used.

(A) Supplying the liquid material When supplying the liquid material, the front panel is held in a horizontal state with its inner surface facing upward, and is held by appropriate holding means. Supply. The holding means may also be used as a rotating means described later. As a supply means of the liquid material, a supply means similar to a known film forming method can be employed. For example, the liquid material stored in a tank or the like can be dropped and supplied from the nozzle to the inner surface of the front panel. The nozzle has the same shape and structure as ordinary liquid supply means such as a cylindrical shape or a slit shape. The liquid material can be supplied by moving the nozzle along the surface of the front panel.
As the nozzle movement pattern, a zigzag line shape, a grid line shape, a concentric shape, a spiral shape, or another pattern can be adopted. Instead of moving the nozzle, the front panel may be moved. The liquid material can be supplied while rotating the front panel.

A heating mechanism is provided in the supply means of the liquid material, and the liquid material can be supplied while being heated to adjust its fluidity. (b) Liquid film forming process By rotating the front panel in parallel with its surface, the liquid material supplied to the front panel is surely spread over the entire surface of the front panel by the action of centrifugal force accompanying the rotation. Form a liquid film. The term “parallel rotation” means that the entire front panel that is gently curved as described above is rotated in a substantially parallel plane. Even if they are not strictly parallel, they may be substantially parallel as long as the object of the present invention is achieved.

In order for centrifugal force to work effectively,
It is efficient to make the center of the planar shape of the front panel the center of rotation. A position deviated from the center of the planar shape can be set as the rotation center. The center of rotation can be changed periodically. When the rotation center itself is rotated, the entire front panel performs a so-called miso rubbing motion. In order to rotate the front panel, the holding means of the front panel may be rotated by rotating means driven by a motor or the like.

By tilting the front panel from the horizontal state while rotating the front panel in parallel, the movement of the liquid material can be promoted by both the action of the centrifugal force and the action of the weight. The front panel can be swung or vibrated. The strength of the centrifugal force acting on the liquid material changes according to the rotation speed of the front panel. Usually, the front panel is rotated at about 20 to 200 rpm.

(C1) Suction Step of Liquid Material Suction of liquid material can be performed by arranging a suction port connected to a vacuum suction device at an outer peripheral corner of the front panel. Normally, the front panel has a rectangular shape, and thus suction ports may be arranged at the four outer corners of the rectangle. The suction port may have a circular nozzle shape, a nozzle shape other than a circular shape, or a slit shape. If the suction port is provided at a position lower than the upper end of the outer peripheral frame of the front panel, it is possible to surely suck the excess liquid material before it adheres to the end surface of the outer peripheral frame. By arranging the suction port slightly above the surface of the liquid film, it is possible to surely suck the excess liquid material without the suction port coming into contact with the liquid film and becoming dirty or damaging the liquid film. it can. By adjusting the shape and position of the suction port, the strength of the suction force, and the like, the amount of the liquid material to be suctioned can be adjusted. Specifically, the suction force is -760 to
Set to about -400 mmHg.

The suction of the liquid material can be performed at the same time as the rotation of the front panel. For this purpose, the suction means including the suction port is rotated together with the front panel. The liquid material sucked at the suction port may be discarded, but can be reused if it is not subjected to a drying action by heating. When the liquid material is reused, the suctioned liquid material can be directly supplied to the supply means by connecting the suction means connected to the suction port to the liquid material supply means via a pipe or the like. .

(D) Drying Step of Liquid Film The drying of the liquid film is performed by a usual drying means. For example,
A heater, a heating furnace, infrared irradiation, hot air blowing, simple air drying, etc., which are arranged above the front panel, are employed.
Drying is performed until the liquid film loses fluidity to the extent that it does not move or deform. The resin may be completely solidified or cured by drying, or may be subjected to a curing treatment after the drying step.

If the drying step is started in the middle of the rotation of the front panel, the liquid film controlled to a desired thickness in the rotation step can be dried while maintaining the state. If the liquid material has lost fluidity to the extent that it does not move or deform significantly, the drying process may be started after the rotation process is completed. When the curing step is performed after drying, the curing means differs depending on the type of liquid material constituting the liquid film, the purpose of use, and the like. In the case of a fluorescent film, it is usually cured by pattern exposure such as ultraviolet rays. After curing, a developing process is performed to remove an unnecessary portion of the liquid film, and a fluorescent film having a desired pattern is formed. When curing with radiation such as ultraviolet rays as the curing treatment, an irradiation device for such radiation is provided. In the case of a reaction-curing liquid material, a liquid or gaseous reaction curing agent can be supplied. Heat curing is also possible.

The front panel on which the target film is formed is sent to a post-process such as a process of assembling and joining with a funnel portion. In the case where a plurality of types of liquid films are formed by lamination or separated and formed in a pattern, the steps from the supply of the liquid material to the curing step and the pattern forming step are repeated as necessary. After a plurality of liquid films are formed without drying, a drying process can be performed at once, or a curing process can be performed.

(C2) Airflow Blowing Step An airflow blowing step is performed instead of the above-described liquid material suction step, or simultaneously with or subsequent to the liquid material suction step, and before the suction step. be able to. The airflow is created by ordinary blowers and blowing means. In addition to air, an inert gas or a reactive gas can be used as the airflow. The airflow outlet is located above the front panel.

When the force of the air flow acts on the liquid film, the liquid material constituting the liquid film moves in the direction in which the air flow flows. Therefore, the direction of the airflow is set so that the airflow is applied from a position where the thickness of the liquid film is relatively thin to a position where the liquid film is desired to be thickened. Where to apply the airflow, the strength or airflow of the airflow,
The thickness of the liquid film can be controlled by adjusting the conditions such as the angle at which the air flows. Specifically, an air volume of 0.5
Set within the range of about 30 l / min.

Since the vicinity of the rotation center of the liquid film is a place where the centrifugal force is less likely to act and the thickness tends to be thicker, the airflow flows from this portion toward the outer periphery from an oblique direction with respect to the rotation center axis of the liquid film. It is effective to blow airflow.
If the air current is applied to the front panel while moving the air outlet, the thickness of the liquid film can be controlled over a wide range. If the outlet is fixed and the front panel is rotated, the liquid film can be controlled in all circumferential directions.

As a control condition of the liquid film, the thickness of the liquid film is 110 to 120 at the outer peripheral portion with respect to the central portion of the front panel.
% Is effective. In this manner, 110-120 at the outer periphery relative to the center
%, The characteristics of the screen, such as brightness and image quality, which tend to decrease at the outer periphery of the cathode ray tube, are improved, and uniform image characteristics such as excellent white balance from the center to the outer periphery are obtained. be able to.

[0028]

1 to 5 show an embodiment of the present invention in the order of steps. As shown in FIG. 1, a front panel 10 made of glass or the like has a panel surface 12 that is gently curved so that a central portion protrudes from an outer peripheral portion when viewed from an inner side when assembled into a CRT. Panel surface 12
Is provided with an outer peripheral frame 14 protruding inward substantially perpendicularly to the panel surface 12. In the drawings, the curvature of the panel surface 12 is exaggerated for easy understanding, but in actuality, the curvature may be slight or almost inconspicuous. The front end surface of the outer peripheral frame 14 is a joint surface with the funnel portion of the cathode ray tube. As shown in FIG. 4, the planar shape of the front panel 10 is substantially rectangular.

[Supply of Liquid Material] As shown in FIG. 1, a liquid material supply device 20 is disposed above the front panel 10.
A supply pipe 24 is connected to the supply device 20 and the liquid material is sent. A supply nozzle 22 is provided at a lower end of the supply device 20.
Is opened, and the liquid material 30 is dropped and supplied to the surface of the front panel 10. The liquid material 30 is applied to the surface of the panel surface 12 while moving the supply device 20 back and forth and right and left above the panel surface 12. The applied liquid material 30 spreads to a certain extent due to its own fluidity, but does not reach the intended uniform liquid film. For example, a liquid material having a viscosity of about 20 cps is used as the liquid material 30, and a liquid material that is about three to four times as large as the liquid material required to finally form a liquid film is supplied. .

[Rotation of Front Panel] As shown in FIG.
The front panel 10 is horizontally rotated about its central axis C in parallel with its surface. The liquid material supplied to the panel surface 12 spreads from the center to the outer periphery or in the circumferential direction by the action of centrifugal force accompanying rotation, and a liquid film 32 having a substantially uniform thickness is formed on the entire panel surface 12. Further, due to the action of the centrifugal force, the liquid material forming the liquid film 32 moves in the outer peripheral direction of the panel surface 12, and the liquid film 32 becomes thinner as a whole. . 3 and 4
The liquid material moves in the direction shown by the broken line in FIG. As shown in FIG. 4, the liquid material that has hit the outer peripheral frame 14 moves to the four corners along the outer peripheral frame 14. As a result, liquid material is accumulated at the four corners.

[Suction of Liquid Material] At four corners of the front panel 10, suction ports 42 of a suction pipe 40 are arranged. The suction pipe 40 is connected to a vacuum suction device. The liquid material sucked by the suction pipe 40 is collected and sent to the supply pipe 24 of the liquid material supply device 20 described above.

As shown in detail in FIG. 3, the suction port 42
It is arranged slightly above the surface of the liquid film 32, and sucks up the liquid material from the liquid film 32 by the suction force from the suction port 42. Since the sucked liquid material is sent to the liquid material supply device 20 via the suction pipe 40, no waste of the liquid material occurs.
By the action of the centrifugal force accompanying the rotation of the front panel 10 and the action of sucking the liquid material from the suction port 42, a relatively thin liquid film 32 having a uniform thickness is quickly formed on the panel surface 12, and
Excess liquid material is removed by suction from the suction port 42. Excessive accumulation of liquid material at the four corners of the front panel 10 is prevented.

The suction operation as described above is performed while the front panel 10 is rotated at a low speed. After the suction of the excess liquid material is completed, the front panel 10 is rotated at a high speed and the liquid film 3 is rotated.
If the ratio 2 is made uniform, scattering of the liquid material is unlikely to occur even when high-speed rotation is performed without performing suction. [Blowing of Air Flow] As shown in FIG. 6, the liquid film 32 formed on the panel surface 12 by the action of the centrifugal force described above has a thickness T ₁ near the rotation center axis C of the front panel 10 and a thickness on the outer peripheral side. It has become thicker than the T _2. This is because the centrifugal force acting on the liquid film 32 is sufficiently large in the outer peripheral portion having a large rotation radius, so that the liquid material moves to the outer periphery, and
, The thickness T ₂ of the liquid film 32 at the outer peripheral portion is sufficiently reduced. On the other hand, the centrifugal force acting on the liquid film 32 is small near the central axis C having a small rotation radius, and the liquid material is unlikely to move, so that the thickness T _{1 of the} liquid film 32 remains large.

As shown in FIG. 5, a blower 50 is arranged above the front panel 10. The blower 50 is provided with a blower port 52 and blows air from the tip of the blower port 52. As shown in FIG. 6, the air outlet 52 blows air in a direction inclined with respect to the center axis C of the front panel 10, and the blown air hits the surface of the liquid film 32 near the center axis C, and The airflow hitting the surface of the film 32 flows from the central axis C to the outer peripheral direction. Due to the force of this air flow, the liquid material forming the liquid film 32 near the center is moved from the center to the outer periphery, the thickness T ₁ near the center is reduced, and the thickness T ₂ near the outer periphery is relatively reduced.
Becomes thicker.

When the front panel 10 rotates with the blower 50 and the blower port 52 fixed, the liquid material forming the liquid film 32 is moved to the outer peripheral side over the entire circumference around the central axis C. And the thickness T ₁ of the liquid film 32 near the center is reduced. The thickness distribution of the liquid film 32 formed on the panel surface 12 is determined by the total action of the action by the air flow, the action by the centrifugal force, and the action by suction as described above. Therefore, the intensity distribution of each of the above actions is adjusted so that a desired thickness distribution is achieved.

Specifically, the thickness of the liquid film 32 is 110 to 120% at the outer peripheral portion with respect to the central portion of the front panel 10.
And the liquid film 32 is controlled so that a large liquid pool does not occur at the four corners on the outer periphery. For example, in the case of a fluorescent film, the thickness of the finally formed liquid film 32 after drying with one color fluorescent film is set to be about 15 to 30 μm on average.

[Drying of Liquid Film] As shown in FIG. 5, a heater 60 is arranged above the front panel 10. By heating the liquid film 32 with the heater 60, the solvent component such as water in the liquid film 32 is removed and the liquid film 32 is dried. When the liquid film 32 is dried to the extent that it loses fluidity, the rotation of the front panel 10, the blowing of the airflow, and the suction of the liquid material are appropriately terminated. However, it is effective to continue rotation of the front panel 10 even during the drying in order to uniformly perform the heating and drying by the heater.

[Post-Process] The dried liquid film 32 is subjected to a post-process in a normal front panel manufacturing process. For example, in the case of a fluorescent film, after applying masking in a pattern form and then performing exposure by ultraviolet irradiation to cure only a necessary region, the liquid film 3 of an uncured uncured portion is subjected to a development process.
Remove 2. As a result, a phosphor film of one of the three colors is formed. Liquid material 3 constituting the other two-color fluorescent films
The same steps as above are sequentially repeated using 0. Thus,
Front panel 10 in which phosphor films of three colors are arranged in a pattern
Is obtained.

When it is not necessary to form a patterned film, pattern exposure and development are unnecessary, and a curing treatment may be performed while the liquid film is dried or after drying. [Structure of Specific Apparatus] The film forming apparatus shown in FIG. 7 includes a turntable 70 for holding the front panel 10 and suction pipes 40 arranged at four internal corners of the front panel 10.

The four suction pipes 40 are supported by a central rotating shaft 44 via a horizontal arm 43. The rotating shaft 44 is supported by an arm 46, and the horizontal arm 43 rotates horizontally about the rotating shaft 44. The rotation of the front panel 10 by the turntable 70 and the horizontal arm 43 to which the suction pipe 40 is attached
By synchronizing the rotation of the front panel 10, the front panel 10 can be rotated while the suction pipes 40 are arranged at the four corners of the front panel 10 to perform the suction operation.

The front panel 10 on which the film has been formed is sent to the next step by rotating the transfer table 72.

[0042]

According to the method and apparatus for forming the inner surface film of a CRT front panel according to the present invention, it is possible to appropriately control the thickness and distribution of the liquid film, and to obtain a high-quality film suitable for the function of the CRT. The membrane can be manufactured efficiently. In particular, by absorbing excess liquid material at the outer peripheral corner of the front panel, it is possible to prevent the thickness of the formed liquid film from locally increasing at the outer peripheral corner. In addition, it is possible to prevent excess liquid material from scattering and contaminating the periphery and the joint surface with the funnel portion. The problem that the scattered liquid material reattaches to the liquid film itself and deteriorates the quality of the film can be solved. If these problems are solved, a large amount of liquid material can be supplied to quickly form a liquid film, and productivity can be improved.

If the thickness of the liquid film is controlled by blowing an airflow onto the surface of the liquid film, the bias of the thickness of the liquid film inherently contained therein can be eliminated by utilizing the action of centrifugal force. By appropriately balancing the action of the centrifugal force and the action of the airflow, and if necessary, the action of the suction, a liquid film having a desired thickness distribution can be formed quickly and reliably.

[Brief description of the drawings]

FIG. 1 is a schematic side view illustrating an embodiment of the present invention and illustrating a first step.

FIG. 2 is a schematic side view showing the next step.

FIG. 3 is a partially enlarged view showing details of the previous figure.

FIG. 4 is a plan view of the previous figure.

FIG. 5 is a schematic side view showing the next step.

FIG. 6 is a partially enlarged view showing details of the previous figure.

FIG. 7 is an overall perspective view of a film forming apparatus.

[Explanation of symbols]

 Reference Signs List 10 front panel 12 panel surface 14 outer peripheral frame 20 liquid material supply device 22 supply nozzle 30 liquid material 32 liquid film 40 liquid material suction pipe 42 suction port 50 blower 52 blower port 60 heater C central axis

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hiroyuki Naka 1006 Kazuma Kadoma, Kadoma City, Osaka Inside Matsushita Electric Industrial Co., Ltd.

Claims (7)

[Claims] 1. A method for applying a liquid material to an inner surface of a front panel of a cathode ray tube to form a film, comprising the following steps (a), (b) and (c1):
A method for forming an inner surface film of a cathode ray tube front panel, comprising the step (d). (a) A step of supplying a liquid material to the inner surface of the front panel. (b) rotating the front panel in parallel with its surface to form a liquid film of the liquid material on the entire surface of the front panel. (c1) A step of sucking excess liquid material at the outer peripheral corner of the front panel. (d) drying the liquid film. 2. A method for applying a liquid material to an inner surface of a front panel of a cathode ray tube to form a film, comprising the following steps (a), (b) and (c2):
A method for forming an inner surface film of a cathode ray tube front panel, comprising the step (d). (a) A step of supplying a liquid material to the inner surface of the front panel. (b) rotating the front panel in parallel with its surface to form a liquid film of the liquid material on the entire surface of the front panel. (c2) a step of controlling the thickness of the liquid film by blowing an air current onto the surface of the liquid film. (d) drying the liquid film. 3. A method for forming a film by applying a liquid material to an inner surface of a front panel of a cathode ray tube, the method comprising the following steps (a), (b) and (c1):
(c2) A method for forming an inner surface film of a CRT front panel, which includes the steps (d). (a) A step of supplying a liquid material to the inner surface of the front panel. (b) rotating the front panel in parallel with its surface to form a liquid film of the liquid material on the entire surface of the front panel. (c1) A step of sucking excess liquid material at the outer peripheral corner of the front panel. (c2) a step of controlling the thickness of the liquid film by blowing an air current onto the surface of the liquid film. (d) drying the liquid film. 4. The method according to claim 1, wherein the excess liquid material is collected and reused. 5. In the airflow blowing step, the thickness of the liquid film is 11 at the outer peripheral portion with respect to the central portion of the front panel.
5. The method according to claim 2, wherein the thickness of the liquid film is controlled to be 0 to 120%. 6. An apparatus for applying a liquid material to an inner surface of a front panel of a cathode ray tube to form a film, comprising: a liquid material supply means for supplying a liquid material to an inner surface of the front panel; Rotating means for rotating the liquid crystal material, liquid material suction means arranged at a position close to the outer peripheral corner of the front panel, and rotating together with the front panel, and drying means for drying a liquid material film formed on the inner surface of the front panel. An inner film forming apparatus for a CRT front panel, comprising: 7. The front surface of a cathode ray tube according to claim 6, further comprising airflow blowing means for blowing an airflow from a direction oblique to a rotation center axis of the front panel toward an outer periphery on a surface near a rotation center of the front panel. Panel inner film forming equipment.