JPH05242804A - Method and device for exposing fluorescent screen of color cathode ray tube - Google Patents

Abstract

PURPOSE:To provide such a method and device for exposing the fluorescent screen of a color cathode ray tube that an exposure time period is shortened and the dotted shape and adhesive strength are improved. CONSTITUTION:A fixed light source 35 gives exposure from the inside of a panel 20 via a shadow mask 21 to a fluorescent plane, and a back exposure light source 11 movable along the curved face of the panel 20 gives exposure from the outside of the panel 20 via a light absorbing film to the fluorescent screen. In this way, more adhesive strength is obtained between the panel plane and the fluorescent screen, and separation and color purity is improved by round the dotted shape of the fluorescent screen perfectly to provide higher quality and better yield in processes. An exposure time period is shortened by combining back exposure therewith, resulting in higher productive efficiency.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exposure method and an apparatus therefor, and more particularly to a method and apparatus for exposing a fluorescent screen from the inside and outside of a color cathode ray tube.

[0002]

2. Description of the Related Art As shown in FIG. 5, a mask structure in which a shadow mask 21 and a frame 22 supporting the shadow mask 21 are integrated is formed on the inner surface of a conventional color cathode ray tube panel 20. It is held by 23. On the inner surface of the panel 20, a phosphor which has been applied and dried in advance is formed together with a photosensitizer, and the phosphor is placed on the exposure table 31 and exposed to a desired pattern. The exposure table 31 sets a light distribution to a desired value, and therefore a dimming filter 32, a correction lens 33 for controlling a trajectory of light,
A slit 34 for controlling the width of light, a light source 35 such as a mercury lamp
And a condenser lens 36 for condensing light on the fluorescent screen side without loss
Etc., and the exposure time is the light source 35 such as a mercury lamp.
And was constrained by slits 34. Japanese Patent Laid-Open No. 214539/1993 discloses an example in which a fluorescent screen is exposed from the front of the outer surface of the panel, and an apparatus in which a large number of tungsten lamps and the like are installed on the outer surface of the panel is disclosed.

[0003]

By the way, in the above-mentioned conventional structure, since the surface of the phosphor is exposed to light, the surface of the phosphor facing the shadow mask 21 is exposed quickly and the photochemical reaction proceeds, but this is essentially necessary. Since the photochemical reaction on the side in contact with the inner surface of the panel was slow, the adhesive strength between the inner surface of the panel 20 and the phosphor was weakened, and the dot shape and size were not constant. Further, the dot diameter and the adhesive strength with the inner surface of the panel fluctuate due to variations in the phosphor lot and the slurry blending lot, which significantly impairs the yield and quality. Furthermore, in order to improve the adhesive strength, it is necessary to increase the dot diameter, that is, it is necessary to lengthen the exposure time, which causes a problem in production efficiency.In addition, increasing the dot diameter causes the dots to partially overlap with adjacent dots. The quality of the color purity of the fluorescent film was significantly impaired.

Further, when performing back exposure as in Japanese Patent Laid-Open No. 3-214539, since partial exposure is performed,
It is difficult to control the dot diameter of the fluorescent screen over the entire panel, and there are problems in terms of quality and management.
There was a drawback that the cost was also high. Therefore, an object of the present invention is to provide a phosphor screen exposure method and apparatus for solving the above problems.

[0005]

As a technical means for solving the above-mentioned problems, the present invention provides a light-absorbing film, a phosphor, and
In a phosphor screen exposure method of a color cathode ray tube for exposing a panel having a shadow mask, a fixed light source is exposed from one side of the panel, and a light source is moved along the curved surface of the panel from the other side. It is characterized by exposing.

Further, during transport of the panel, the fluorescent surface is exposed through a light absorbing film by a light source which moves along the outer surface of the panel.

Further, in the exposure apparatus, the exposure unit is composed of an exposure base having a fixed light source and a light control unit, and the light source is moved along the curved surface of the panel positioned and installed on the exposure base to perform exposure. It is characterized by including the exposed part.

[0008]

According to the above construction, since the light source is moved along the curved surface of the panel, only one back exposure light source is required, and the entire panel can be uniformly back exposed, so that there is no variation in exposure and control is possible. Cheap. Therefore, the dot shape and size of the phosphor can be made uniform, and the adhesive strength can be improved, so that the quality and yield of the phosphor screen are improved. Further, after the phosphor is applied, the backside exposure can be easily performed on the conveyor which is being conveyed to the exposure table, so that the facility can be easily adapted and it is very inexpensive.

[0009]

1 is a sectional view showing the outline of an entire fluorescent screen exposure apparatus according to an embodiment of the present invention, and FIG. 2 is a perspective view showing the outline of a back exposure light source and its carrying section.

The fluorescent screen exposure apparatus 1 of the present invention comprises a fixed light source 3
The front exposure unit 30 is composed of an exposure table 31 for exposing at 5 and the back exposure unit 10 for exposing with a moving light source. Since the internal structure of the exposure table 31 is the same as that of the conventional one, the same reference numerals as those of the conventional one are used and the description thereof is omitted.

As shown in FIG. 2, the rear exposure unit 10 of the present invention includes at least a rear exposure light source 11, a curved reflecting plate 12 for efficient use of light, and these along a curved surface of the panel 20. It has a light source transport unit 13 for moving and a control unit 14 (details not shown) for controlling the transport.

When the panel 20 is installed on the exposure table 31,
A signal is sent to the control unit 14, electricity is supplied to the backside exposure light source 11, and the backside exposure light source 11 is turned on. When the light source is turned on, an automatic control circuit (not shown) operates in the control unit 14 to operate the cam 13b (the cam rotation mechanism is not shown), and the cam 13b moves from end to end of the panel 20.
Moves on the arched rail 13a along the curved surface of the panel 20 to perform back exposure. The moving speed of the cam 13b is preset in the control unit 14, and is adjusted so as not to be longer than the exposure time of the front exposure by the exposure table 31. The light source 11 is adjusted so as to follow the curved surface of the panel 20, and is regulated by the hole diameter of the light absorbing film described later to prevent light from being dispersed and transmitted. Be done.

That is, as shown in the enlarged cross-sectional view of the main part of the panel 20 of FIG. 3, the light absorption film 25 formed in advance before the formation of the phosphor 26 is the shadow mask 2 at the time of front exposure.
1 plays a role of 1, the exposure area of the phosphor is regulated, the defect that the outer shape of the phosphor dot is gear-shaped, which is a defect of the conventional method, is solved, and a perfect circle dot is obtained. This is because the phosphor particle size is 7-10 μm, and the mask (light absorption film)
The non-exposure part of the phosphor covered with is exposed by the light incident from the oblique direction, but since the light source moves, the exposure amount is reduced compared to the conventional fixed light source, and therefore the adhesive strength is increased. This is because it is weak, and unnecessary phosphors can be easily removed in a later step. As a result, for example, a blue phosphor 26a having a predetermined dot diameter 27 can be formed. Similarly, the green phosphor 26b and the red phosphor 26c are sequentially formed.

Next, the effect of exposure by the phosphor screen exposure method of the present invention will be described from another point of view. In general, the exposure constant, which is a guideline of the exposure amount, is determined by the product of the exposure time and the light intensity of the light source. Therefore, as shown in FIG. , The relative exposure intensity is 1.15 in the curve of b,
The exposure time becomes longer. On the other hand, by performing the back exposure in addition to the front exposure according to the present invention, the normal exposure constant can be reduced by the exposure constant of c, and the curve of a can be applied, so that the exposure time can be reduced to 0.8, for example. Can be shortened.

The backside exposure according to the present invention may be carried out while the panel 20 is being transferred, other than on the exposure table 31, and is not restricted by the installation location. The light source may be a mercury lamp or a fluorescent lamp and is not particularly limited. In addition, in the above-described embodiment, the configuration is described in which the fixed light source is exposed from the inner surface side of the panel and the movable light source is exposed from the outer surface side of the panel, but the present invention is not limited to this configuration, and the panel is vertically moved. You may reverse and arrange.

[0016]

According to the present invention, the panel surface can be uniformly exposed, the exposure time can be shortened, and the production efficiency can be improved, and the quality of the fluorescent film can be improved by improving the adhesive strength and the dot shape / dimension. Yield can be improved. In addition, the above effects can be realized with inexpensive equipment without specially expensive equipment investment.

[Brief description of drawings]

FIG. 1 is a sectional view showing an outline of a fluorescent screen exposure apparatus according to an embodiment of the present invention.

FIG. 2 is a perspective view showing an outline of a back exposure unit of the present invention.

FIG. 3 is a characteristic diagram showing a relationship between a dot diameter and a relative exposure constant.

FIG. 4 is an enlarged sectional view of an essential part of a phosphor screen for explaining a dot diameter.

FIG. 5 is a sectional view showing the outline of a conventional exposure apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fluorescent screen exposure device 10 Back exposure unit 11 Back exposure light source 12 Reflector 13 Light source transport unit 13a Rail 13b Cam 14 Control unit 20 Panel 21 Shadow mask 25 Light absorbing film 26 Phosphor 27 Dot diameter 30 Front exposure unit 31 Exposure table 35 Fixed light source

Claims (3)

[Claims] 1. A method for exposing a fluorescent screen of a color cathode ray tube, which exposes a panel having a light absorption film, a phosphor and a shadow mask, wherein one side of the panel is exposed with a fixed light source and the other side is exposed. The method for exposing a fluorescent surface of a color cathode ray tube is characterized in that the exposure is performed by a light source that moves along the curved surface of the panel. 2. The fluorescent screen exposure of a color cathode ray tube according to claim 1, wherein the fluorescent screen is exposed through a light absorbing film by a light source which moves along the outer surface of the panel during the transportation of the panel. Method. 3. A front exposure section comprising an exposure table having a fixed light source and a light control section, a transportation section for moving the light source along a curved surface of a panel positioned on the exposure table, and a transportation section provided on this transportation section. And a rear exposure unit including a light source, and a fluorescent screen exposure apparatus for a color cathode ray tube.