KR20010018042A - Shape methode of graphite layer for CRT - Google Patents

Abstract

PURPOSE: A method for forming a graphite layer of a color cathode-ray tube is provided to remove afterimages of passing holes in an intermediate surface by using two layers of graphite as a black matrix. CONSTITUTION: An inner surface of a panel glass(1) is washed and photo-resist(30) is evenly coated thereon. By using a tension mask(5) including an intermediate surface with passing holes, the photo-resist(30) is exposed by light and developed by water. Then, a predetermined pattern of the photo-resist(30) is obtained on the panel(1). The first graphite film(31) is formed by coating graphite on the patterned photo-resist(30) and by etching the resultant structure. The second graphite film(32) is formed on the region of an inefficient surface in the panel by coating graphite on an entire surface of the resultant structure. Thereby, the uneven surface of the first graphite film(31) due to the passing holes of the intermediate surface can be filled with the second graphite film(32).

Description

Graphite layer formation method of color cathode ray tube {Shape methode of graphite layer for CRT}

The present invention relates to a color cathode ray tube, and more particularly, a tension mask that performs the color discrimination function of an electron beam in a cathode ray tube has an effective surface and an invalid surface boundary region due to a stress difference for each region when a tensile force is applied from the outside. The present invention relates to a graphite layer forming method for improving screen defects generated during the process of forming a fluorescent film using the tension mask when a through hole is formed in an intermediate surface to improve the breakage phenomenon.

In general, color cathode ray tubes are the most widely used display devices for observation of oscilloscopes, radars, etc., including television receivers.

The color cathode ray tube includes red, green, and blue phosphor pixels having three primary color emission spectra of light, which is an all-optical device that converts image information received as an electric signal into visual information, a graphite layer as a light absorbing material, In addition, the device reproduces color images through a fluorescent film made of aluminum film for improving luminance, and delivers them to human vision. When power for operation is applied, electrons are activated at the cathode of the electron gun and are emitted by the electric field. . At this time, the electron beam having the kinetic energy accelerated by the acceleration electrode of several tens of kV is made to be a constant velocity motion and finally hit the fluorescent surface formed in a predetermined pattern on the inner surface of the screen to emit the phosphor to implement the image. At this time, about 75 to 80% of the accelerated electrons are blocked by the mask, which is a color-selective electrode, and only the remaining light passes through the electron beam passing holes formed on the mask surface to reach the screen to emit light.

The blocked electrons are decelerated in a short time so that almost all of the kinetic energy is converted into thermal energy, and the rest are converted into electromagnetic waves and the like to satisfy the law of energy conservation.

On the other hand, the thermal energy converted into kinetic energy thermally expands the mask made of metal, thereby causing displacement of the electron beam through hole at the position, which changes the path of the electron beam incident on the screen, thereby lowering the color purity. This property is called doming, and in order to reduce this phenomenon, recently, a tension mask of a thin film has been used.

Such tension masks counteract thermal strain due to thermal expansion by applying a mechanical strain, that is, a tensile force in advance, and a grill mask that is only stretched in the vertical direction depending on the direction in which the strain is applied, or horizontal / vertical. It is divided into a kind of flat tension mask which stretches in all directions.

In particular, the tension mask has a myriad of through holes through which the electron beam can pass, and the electron beam through holes thus formed correspond to the R, G, and B phosphors on the inner surface of the screen.

The apparatus shown in FIG. 1 is described as an example of the planar cathode ray tube to which the tension mask is applied.

The flat cathode ray tube forms a front screen and a panel 1 having a fluorescent surface 1a formed on an inner side thereof, and a rear side of the panel 1 which is coupled to a rear side of the panel 1 to form a high vacuum, and to which an internal graphite is coated on an inner surface thereof. The outer container is formed of a funnel (2).

In the neck portion of the funnel 2, an electron gun 3 emitting three electron beams of R, G, and B is enclosed, and an electron beam emitted from the electron gun can be landed on the entire screen on the front side of the electron gun 3. A deflection yoke (4) for deflecting is positioned, and a flat tension mask (5) for screening electron beams is fixed to the rail (6) inside the panel (1) in a state where tensile force is applied thereto. It is located at a constant interval with the.

On the other hand, the flat tension mask 5 is formed of a metal plate of a thin film (about 0.025mm or less), the structure is formed of an effective surface formed by a constant pitch of a myriad of slot-shaped through-holes 7 so that the electron beam can pass through The through hole 7 is not formed and the end surrounding the outer part is divided into an ineffective surface welded to the rail 6.

In such a conventional tension mask, a tensile force is applied by being uniformly pulled outward in the direction perpendicular to each side and welded to the rail 6. As a result, an unbalance of stress and a sudden change in the elastic modulus occur at the boundary of the effective surface where the ineffective surface and the through hole 7 have the same vertical spacing, so that the through hole 7 is the first to third of the effective surface. Between the second row, a bridge that vertically separates the through hole of the mask and breaks through is broken, resulting in a loss in the fabrication of the cathode ray tube.

When the tension is applied to the mask as described above, the mask shape shown in Fig. 2 sufficiently improves the fracture of the mask. This constitutes an intermediate surface 11 in which a through hole 7 of increasing size is formed in an area adjacent to the effective surface 10 on the invalid surface 12 of the mask corresponding to the invalid surface of the screen. When the tension is applied to the mask 5, the stress generated on the ineffective surface 12 without the through hole 7 is buffered and transmitted to the effective surface 10 to prevent the mask from breaking and to provide uniform stress. Have it in front of the mask. Reference numeral 5a denotes a welding surface with the rail 6.

On the other hand, after forming a photosensitive agent on the inner surface of the panel 1 during the formation process of the fluorescent film, the mask is exposed, the mask is exposed, the mask is removed, and the operation such as developing the exposed portion formed on the photosensitive film is repeated. In the method of forming the graphite layer of the screen, that is, the black matrix (BM) in such a manner as described above, the through hole 7 of the intermediate surface 11 corresponding to the position corresponding to the ineffective surface of the screen is imprinted on the screen as it is. It must be.

That is, when the black matrix is formed by using the tension mask 5 as shown in FIG. 2 in a detachable manner, as shown in FIG. 3, the black matrix is imprinted on the non-effective surface 22 of the panel 1 forming the screen as it is. The black matrix is formed on the part, which not only visually discomforts but also adversely affects the quality of the screen.

For example, an unintentional increase in the area of the screen makes it particularly vulnerable to color purity, alignment of the red / green / blue phosphor (R / G / B) black matrix. When a screen of a color cathode ray tube equipped with a general slot-type shadow mask is manufactured by a photolithography method, a screen of the cathode ray tube is linearly formed since a linear light source is generally used to sensitize the photosensitive agent.

However, in the case of a color cathode ray tube equipped with a mask composed of an effective surface 10 and an invalid surface 12 without an intermediate surface, as shown in FIG. 4, the effective surface 20 and the invalid surface 22 of the screen are shown. ), The black matrix BM is clearly formed, but when the tension mask 5 having the intermediate surface 11 is used as shown in FIG. 2, the screen is manufactured by a conventional photo-drying method, as shown in FIG. 3. Due to the small through hole formed in the middle surface 11 of the mask, the portion corresponding to the ineffective surface 22 of the screen has a problem of forming a rough and abnormal black matrix, not a smooth linear black matrix BM.

The present invention is to solve the above problems of the prior art, while using a tension mask having an intermediate surface with a through hole formed in the ineffective surface to increase the tensile strength of the mask for exposure during the fluorescent film forming process, It is an object of the present invention to provide a method for forming a graphite film which can prevent the degradation of the graphite film caused by the passage hole.

1 is an exploded perspective view of a panel of a typical flat cathode ray tube;

2 is a structural diagram of a conventional tension mask.

Figure 3 is a BM form of the screen produced using the tension mask.

4 is a BM form of an ideal screen for the purposes of the present invention.

5 is a BM forming process according to the present invention.

6 is a panel mounting state of the mask to be applied during the exposure process in one embodiment of the present invention.

Figure 7 is a cross-sectional view of the completed fluorescent film according to the present invention.

** Description of symbols for the main parts of the drawing ***

1 panel, 5 tension mask, 10 mask effective surface, 11 mask middle surface

12: mask invalid surface, 20: screen effective surface, 22: screen invalid surface

30: photosensitive agent, 31: primary graphite film, 32: secondary graphite film

According to one aspect of the present invention for realizing the above object, a graphite layer having a predetermined pattern is formed by using an exposure mask in which an intermediate surface having a passage hole is formed at an effective surface side boundary of an ineffective surface where a passage hole is not formed. In the fluorescent film forming process of a color cathode ray tube, red, green, and blue phosphor are formed between the patterns of the graphite layer:

Formation of the graphite layer,

(1) uniformly applying a photosensitive agent to the panel surface;

(2) exposing and applying the applied photosensitive agent to a predetermined pattern by using the mask;

(3) forming a primary graphite film by coating and etching graphite on the patterned photosensitive agent; And

(4) forming a secondary graphite film on the panel ineffective surface region corresponding to the intermediate surface of the mask after forming the primary graphite film.

Optionally, the forming of the secondary graphite film may include: (1) uniformly applying a photosensitive agent to the panel surface on which the primary graphite film is formed; (2) exposing and developing the applied photosensitive agent using an exposure mask covering the passage hole of the intermediate surface to form a predetermined pattern; (3) forming a secondary graphite film by coating and etching graphite on the patterned photoresist;

Alternatively, the secondary graphite film is formed by hand using a brush or the like.

In addition, the present invention according to another aspect for realizing the object of the present invention, by using an exposure mask formed with an intermediate surface having a through hole at the effective surface side boundary of the non-effective surface is not formed through a certain pattern of graphite layer In the fluorescent film forming step of the color cathode ray tube which is formed, wherein red, green, and blue phosphors are formed between the patterns of the graphite layer:

Formation of the graphite layer,

(1) uniformly applying a photosensitive agent to the panel surface;

(2) forming a predetermined pattern by exposing and developing the coated photosensitive agent by covering a through hole of the mask intermediate surface;

(3) characterized in that it comprises a step of forming a pattern by applying and etching graphite on the patterned photosensitive agent.

In this way, when a graphite film, ie, a black matrix, is formed on the inner surface of a panel glass equipped with a removable mask consisting of an effective surface, an intermediate surface, and an invalid surface, the imprint due to the intermediate surface of the mask is removed. It can be seen that the black matrix can be formed in two layers in the screen non-effective region or in a single layer in which imprinting of the screen non-effective region does not appear, thereby improving an unobtrusive area during viewing.

As a result, there is an advantage that a high quality screen can be provided.

And, there may be a plurality of embodiments of the present invention, hereinafter will be described in detail with respect to the most preferred embodiment.

Hereinafter, preferred embodiments of the graphite layer forming method according to the present invention will be described in detail with reference to the accompanying drawings.

In addition, in drawing used for description, about the component similar to the prior art, the same code | symbol is attached | subjected, and the overlapping description may be abbreviate | omitted.

5 is a flowchart illustrating a fluorescent layer forming process according to an embodiment of the present invention, FIG. 6 is a mask mounting state diagram for exposing a fluorescent film according to an embodiment of the present invention, and FIG. 7 is a black matrix and a phosphor formed through the above embodiment. It is a cross section of.

Referring to FIG. 5, a black matrix forming process according to an embodiment is performed. The inner surface of the panel glass 1 is washed with a detergent, pure water, airborne water, or the like as ST1 and then uniformly applied by injecting a photosensitive agent 30. Then, the mask 5 is mounted on the panel 1 and the photosensitive agent 30 is exposed in a predetermined pattern as in ST2 through the linear light source. After that, when the photosensitive part is developed with water, only the photoresist 30 pattern remains on the panel 1 as in ST3. Then, after coating the graphite liquid as in ST4, the patterned photoresist 30 is etched. When the graphite liquid applied on the photosensitive agent such as ST5 is etched together with the photosensitive agent, the primary graphite film 31 is completed at the remaining portion. Finally, when the operator applies the secondary graphite film 32 such as ST6 using a brush or the like to form an area that is not uniform due to the intermediate surface 11 of the mask 5 in which the through hole is formed, the final black matrix pattern Will be completed.

On the other hand, in another embodiment for forming the secondary graphite film 32, after the first graphite film 31 is completed, the photosensitive agent is uniformly applied to the panel 1, and then the intermediate surface ( The through hole of 11) is masked using the mask 5, and the mask mounting state at this time is shown in FIG. After the process such as development → graphite coating → etching, the secondary graphite film 32 is formed on the primary graphite film 31 to complete the black matrix.

A state in which phosphors (R, G, B) are coated on the two black matrix patterns thus completed is shown in FIG. 7.

In another embodiment of the present invention, in order to improve the process of forming a two-layer black matrix pattern, the through hole of the mask intermediate surface 11 during the mask exposure of the photosensitive agent for pattern formation of the primary graphite film is formed. When the exposure is performed in a hidden state as shown in FIG. 5, the subsequent formation of the black graphite pattern can be completed without the need for the subsequent formation of the second graphite film, thereby shortening the formation process of the black matrix to the through hole of the intermediate surface. It is possible to prevent the imprinting of the screen invalid surface caused.

That is, when the black matrix forming method described in the above embodiments is used, even when a color cathode ray tube is manufactured by a mask detachable method using a tension mask having a through hole formed in the intermediate surface 11, the surface of the screen is ineffective. It can be seen that the black matrix can be formed uniformly and evenly.

As a result, according to the present invention, while using a mask for increasing the tensile strength of the mask, at the same time the unobtrusive part on the screen is removed, it is possible to implement a high-quality screen.

In addition, although specific embodiments of the present invention have been described and illustrated above, it is obvious that the method of forming the black matrix of the present invention may be variously modified and implemented by those skilled in the art.

Such modified embodiments should not be individually understood from the technical spirit or the prospect of the present invention, and such modified embodiments should fall within the appended claims of the present invention.

As described above, according to the present invention, in the manufacture of the graphite layer of the color cathode ray tube by the photo-drying method of the mask detachable method, in order to increase the tensile strength of the mask made of an effective surface, an effective surface, and an intermediate surface, There is an advantage that a high quality graphite film can be formed while using a tension mask in which a through hole is formed in the intermediate surface.

Claims (4)

A graphite layer having a predetermined pattern is formed by using an exposure mask having an intermediate surface having a through hole at an effective surface side boundary of an ineffective surface where no through hole is formed, and red, green, and blue phosphors are formed between the patterns of the graphite layer. In the process of forming a fluorescent film of a colored cathode ray tube: Formation of the graphite layer, (1) uniformly applying a photosensitive agent to the panel surface; (2) exposing and applying the applied photosensitive agent to a predetermined pattern by using the mask; (3) forming a primary graphite film by coating and etching graphite on the patterned photosensitive agent; And And (4) forming a secondary graphite film on the panel non-effective surface area corresponding to the intermediate surface of the mask after the formation of the primary graphite film. The method of claim 1, The process of forming the secondary graphite film, the graphite layer forming method of the color cathode ray tube, characterized in that formed by hand using a tool. The method of claim 1, The process of forming the secondary graphite film, (1) uniformly applying a photosensitive agent to the panel surface on which the primary graphite film is formed; (2) exposing and developing the applied photosensitive agent to form a predetermined pattern by using an exposure mask in which a through hole is hidden in the intermediate surface; (3) forming a secondary graphite film by coating and etching graphite on the patterned photosensitive agent to form a secondary graphite film. A graphite layer having a predetermined pattern is formed by using an exposure mask having an intermediate surface having a through hole at an effective surface side boundary of an ineffective surface where no through hole is formed, and red, green, and blue phosphors are formed between the patterns of the graphite layer. In the process of forming a fluorescent film of a colored cathode ray tube: Formation of the graphite layer, (1) uniformly applying a photosensitive agent to the panel surface; (2) forming a predetermined pattern by exposing and developing the coated photosensitive agent by covering a through hole of the mask intermediate surface; (3) forming a pattern by coating graphite on the patterned photosensitive agent and then etching to form a pattern.